GDB 7.4.1
diff --git a/bfd/doc/bfdver.texi b/bfd/doc/bfdver.texi
index 1b8fa1d..86eaaaa 100644
--- a/bfd/doc/bfdver.texi
+++ b/bfd/doc/bfdver.texi
@@ -1,4 +1,4 @@
@set VERSION 2.22.51
@set VERSION_PACKAGE (GNU Binutils)
-@set UPDATED January 2012
+@set UPDATED April 2012
@set BUGURL @uref{http://www.sourceware.org/bugzilla/}
diff --git a/djunpack.bat b/djunpack.bat
index 33c0a23..7dc1489 100644
--- a/djunpack.bat
+++ b/djunpack.bat
@@ -17,8 +17,8 @@
Rem The following 2 lines need to be changed with each new GDB release, to
Rem be identical to the name of the top-level directory where the GDB
Rem distribution unpacks itself.
-set GDBVER=gdb-7.4
-if "%GDBVER%"=="gdb-7.4" GoTo EnvOk
+set GDBVER=gdb-7.4.1
+if "%GDBVER%"=="gdb-7.4.1" GoTo EnvOk
Rem If their environment space is too small, re-exec with a larger one
command.com /e:4096 /c %0 %1
GoTo End
diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index f3bbf0f..67a46b4 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,82 @@
+2012-04-26 Joel Brobecker <brobecker@adacore.com>
+
+ * version.in: Update GDB version number to 7.4.1.
+
+2012-04-24 Marc Khouzam <marc.khouzam@ericsson.com>
+
+ * mi/mi-main.c (mi_cmd_execute): Choose a live thread not just
+ any thread.
+
+2012-04-13 Pierre Muller <muller@ics.u-strasbg.fr>
+
+ * p-typeprint.c (pascal_type_print_method_args):
+ Fix display of parameter of methods.
+
+2012-03-20 Pedro Alves <palves@redhat.com>
+
+ * remote.c (remote_start_remote): Clear `rs->starting_up' on early
+ returns.
+
+2012-03-13 Hui Zhu <teawater@gmail.com>
+ Pedro Alves <palves@redhat.com>
+
+ * breakpoint.c (init_breakpoint_sal): New flags parameter. Handle
+ CREATE_BREAKPOINT_FLAGS_INSERTED.
+ (create_breakpoint_sal, create_breakpoints_sal)
+ (create_breakpoint): New flags parameter. Pass it down.
+ (break_command_1, handle_gnu_v3_exceptions, trace_command)
+ (ftrace_command, strace_command): Adjust.
+ (create_tracepoint_from_upload): Pass
+ CREATE_BREAKPOINT_FLAGS_INSERTED.
+ * breakpoint.h (enum breakpoint_create_flags): New.
+ (create_breakpoint): New flags parameter.
+ * mi/mi-cmd-break.c (mi_cmd_break_insert): Adjust.
+ * python/py-breakpoint.c (bppy_init): Adjust.
+ * python/py-finishbreakpoint.c (bpfinishpy_init): Adjust.
+ * spu-tdep.c (spu_catch_start): Adjust.
+
+2012-03-13 Pedro Alves <palves@redhat.com>
+ Hui Zhu <teawater@gmail.com>
+ Yao Qi <yao@codesourcery.com>
+
+ * remote.c (struct remote_state): New field `starting_up'.
+ (remote_start_remote): Set and clear it.
+ (remote_can_download_tracepoint): If starting up, return false.
+
+2012-03-06 Pedro Alves <palves@redhat.com>
+
+ PR gdb/13766
+
+ * i387-tdep.c (i387_supply_xsave): If we have an xsave buffer, and
+ the register state is clear, supply explicit zero, instead of
+ marking the register unavailable.
+
+2012-02-23 Jan Kratochvil <jan.kratochvil@redhat.com>
+
+ PR backtrace/13716
+ * infcmd.c (finish_forward): New variable frame_id, initialize it, use
+ it after set_momentary_breakpoint.
+
+2012-02-21 Jan Kratochvil <jan.kratochvil@redhat.com>
+
+ PR build/13638
+ * configure.ac (MAKEINFO): Replace AC_CHECK_PROG by AC_ARG_VAR.
+ (MAKEINFOFLAGS): Replace static string by AC_ARG_VAR.
+ * configure: Regenerate.
+
+2012-02-21 Jan Kratochvil <jan.kratochvil@redhat.com>
+
+ * configure: Regenerate.
+ * config.in: Regenerate.
+
+2012-01-24 Joel Brobecker <brobecker@adacore.com>
+
+ * version.in: Set version to 7.4.0.20120124-cvs.
+
+2012-01-24 Joel Brobecker <brobecker@adacore.com>
+
+ GDB 7.4 released.
+
2012-01-24 Joel Brobecker <brobecker@adacore.com>
* NEWS: Change "since GDB 7.3.1" into "in GDB 7.4".
diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
index a0beb15..5a8c29c 100644
--- a/gdb/breakpoint.c
+++ b/gdb/breakpoint.c
@@ -7248,7 +7248,8 @@
enum bptype type, enum bpdisp disposition,
int thread, int task, int ignore_count,
const struct breakpoint_ops *ops, int from_tty,
- int enabled, int internal, int display_canonical)
+ int enabled, int internal, unsigned flags,
+ int display_canonical)
{
int i;
@@ -7294,6 +7295,9 @@
b->enable_state = enabled ? bp_enabled : bp_disabled;
b->disposition = disposition;
+ if ((flags & CREATE_BREAKPOINT_FLAGS_INSERTED) != 0)
+ b->loc->inserted = 1;
+
if (type == bp_static_tracepoint)
{
struct tracepoint *t = (struct tracepoint *) b;
@@ -7337,6 +7341,8 @@
else
{
loc = add_location_to_breakpoint (b, &sal);
+ if ((flags & CREATE_BREAKPOINT_FLAGS_INSERTED) != 0)
+ loc->inserted = 1;
}
if (bp_loc_is_permanent (loc))
@@ -7369,7 +7375,8 @@
enum bptype type, enum bpdisp disposition,
int thread, int task, int ignore_count,
const struct breakpoint_ops *ops, int from_tty,
- int enabled, int internal, int display_canonical)
+ int enabled, int internal, unsigned flags,
+ int display_canonical)
{
struct breakpoint *b;
struct cleanup *old_chain;
@@ -7392,7 +7399,8 @@
type, disposition,
thread, task, ignore_count,
ops, from_tty,
- enabled, internal, display_canonical);
+ enabled, internal, flags,
+ display_canonical);
discard_cleanups (old_chain);
install_breakpoint (internal, b, 0);
@@ -7420,7 +7428,7 @@
enum bptype type, enum bpdisp disposition,
int thread, int task, int ignore_count,
const struct breakpoint_ops *ops, int from_tty,
- int enabled, int internal)
+ int enabled, int internal, unsigned flags)
{
int i;
struct linespec_sals *lsal;
@@ -7444,7 +7452,7 @@
filter_string,
cond_string, type, disposition,
thread, task, ignore_count, ops,
- from_tty, enabled, internal,
+ from_tty, enabled, internal, flags,
canonical->special_display);
discard_cleanups (inner);
}
@@ -7704,7 +7712,8 @@
int ignore_count,
enum auto_boolean pending_break_support,
const struct breakpoint_ops *ops,
- int from_tty, int enabled, int internal)
+ int from_tty, int enabled, int internal,
+ unsigned flags)
{
volatile struct gdb_exception e;
char *copy_arg = NULL;
@@ -7886,7 +7895,7 @@
cond_string, type_wanted,
tempflag ? disp_del : disp_donttouch,
thread, task, ignore_count, ops,
- from_tty, enabled, internal,
+ from_tty, enabled, internal, flags,
canonical.special_display);
/* Given that its possible to have multiple markers with
the same string id, if the user is creating a static
@@ -7906,7 +7915,7 @@
type_wanted,
tempflag ? disp_del : disp_donttouch,
thread, task, ignore_count, ops, from_tty,
- enabled, internal);
+ enabled, internal, flags);
}
else
{
@@ -7982,7 +7991,8 @@
&bkpt_breakpoint_ops,
from_tty,
1 /* enabled */,
- 0 /* internal */);
+ 0 /* internal */,
+ 0);
}
/* Helper function for break_command_1 and disassemble_command. */
@@ -9838,7 +9848,8 @@
AUTO_BOOLEAN_TRUE /* pending */,
&gnu_v3_exception_catchpoint_ops, from_tty,
1 /* enabled */,
- 0 /* internal */);
+ 0 /* internal */,
+ 0);
return 1;
}
@@ -12769,7 +12780,7 @@
&tracepoint_breakpoint_ops,
from_tty,
1 /* enabled */,
- 0 /* internal */))
+ 0 /* internal */, 0))
set_tracepoint_count (breakpoint_count);
}
@@ -12786,7 +12797,7 @@
&tracepoint_breakpoint_ops,
from_tty,
1 /* enabled */,
- 0 /* internal */))
+ 0 /* internal */, 0))
set_tracepoint_count (breakpoint_count);
}
@@ -12805,7 +12816,7 @@
&tracepoint_breakpoint_ops,
from_tty,
1 /* enabled */,
- 0 /* internal */))
+ 0 /* internal */, 0))
set_tracepoint_count (breakpoint_count);
}
@@ -12870,7 +12881,8 @@
&tracepoint_breakpoint_ops,
0 /* from_tty */,
utp->enabled /* enabled */,
- 0 /* internal */))
+ 0 /* internal */,
+ CREATE_BREAKPOINT_FLAGS_INSERTED))
return NULL;
set_tracepoint_count (breakpoint_count);
diff --git a/gdb/breakpoint.h b/gdb/breakpoint.h
index c1d3be9..3548d13 100644
--- a/gdb/breakpoint.h
+++ b/gdb/breakpoint.h
@@ -1105,6 +1105,16 @@
extern void install_breakpoint (int internal, struct breakpoint *b,
int update_gll);
+/* Flags that can be passed down to create_breakpoint, etc., to affect
+ breakpoint creation in several ways. */
+
+enum breakpoint_create_flags
+ {
+ /* We're adding a breakpoint to our tables that is already
+ inserted in the target. */
+ CREATE_BREAKPOINT_FLAGS_INSERTED = 1 << 0
+ };
+
extern int create_breakpoint (struct gdbarch *gdbarch, char *arg,
char *cond_string, int thread,
int parse_condition_and_thread,
@@ -1114,7 +1124,7 @@
const struct breakpoint_ops *ops,
int from_tty,
int enabled,
- int internal);
+ int internal, unsigned flags);
extern void insert_breakpoints (void);
diff --git a/gdb/config.in b/gdb/config.in
index 4af4e69..4aff10d 100644
--- a/gdb/config.in
+++ b/gdb/config.in
@@ -158,6 +158,9 @@
*/
#undef HAVE_DIRENT_H
+/* Define to 1 if you have the <dlfcn.h> header file. */
+#undef HAVE_DLFCN_H
+
/* Define if ELF support should be included. */
#undef HAVE_ELF
@@ -725,6 +728,13 @@
/* Define as const if the declaration of iconv() needs const. */
#undef ICONV_CONST
+/* directory to load the JIT readers from */
+#undef JIT_READER_DIR
+
+/* Define if the jit-reader-dir directory should be relocated when GDB is
+ moved. */
+#undef JIT_READER_DIR_RELOCATABLE
+
/* Define to a substitute value for mmap()'s MAP_ANONYMOUS flag. */
#undef MAP_ANONYMOUS
@@ -810,6 +820,15 @@
/* The size of `long', as computed by sizeof. */
#undef SIZEOF_LONG
+/* The size of `unsigned long', as computed by sizeof. */
+#undef SIZEOF_UNSIGNED_LONG
+
+/* The size of `unsigned long long', as computed by sizeof. */
+#undef SIZEOF_UNSIGNED_LONG_LONG
+
+/* The size of `unsigned __int128', as computed by sizeof. */
+#undef SIZEOF_UNSIGNED___INT128
+
/* Define to l, ll, u, ul, ull, etc., as suitable for constants of type
'size_t'. */
#undef SIZE_T_SUFFIX
@@ -982,12 +1001,3 @@
/* Define as `fork' if `vfork' does not work. */
#undef vfork
-
-/* The directory from which JIT readers should be loaded. */
-#undef JIT_READER_DIR
-
-/* Define if JIT_READER_DIR should be relocated when GDB is moved. */
-#undef JIT_READER_DIR_RELOCATABLE
-
-/* Define if the platform has dlfcn.h. */
-#undef HAVE_DLFCN_H
diff --git a/gdb/configure b/gdb/configure
index 6408fc2..7d11e98 100755
--- a/gdb/configure
+++ b/gdb/configure
@@ -995,6 +995,8 @@
LIBS
CPPFLAGS
CPP
+MAKEINFO
+MAKEINFOFLAGS
YACC
YFLAGS
XMKMF'
@@ -1696,6 +1698,9 @@
CPPFLAGS C/C++/Objective C preprocessor flags, e.g. -I<include dir> if
you have headers in a nonstandard directory <include dir>
CPP C preprocessor
+ MAKEINFO Parent configure detects if it is of sufficient version.
+ MAKEINFOFLAGS
+ Parameters for MAKEINFO.
YACC The `Yet Another C Compiler' implementation to use. Defaults to
the first program found out of: `bison -y', `byacc', `yacc'.
YFLAGS The list of arguments that will be passed by default to $YACC.
@@ -7158,59 +7163,9 @@
-# Do we have a single-tree copy of texinfo? Even if we do, we can't
-# rely on it - libiberty is built before texinfo.
-# Extract the first word of "makeinfo", so it can be a program name with args.
-set dummy makeinfo; ac_word=$2
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
-$as_echo_n "checking for $ac_word... " >&6; }
-if test "${ac_cv_prog_MAKEINFO+set}" = set; then :
- $as_echo_n "(cached) " >&6
-else
- if test -n "$MAKEINFO"; then
- ac_cv_prog_MAKEINFO="$MAKEINFO" # Let the user override the test.
-else
-as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
-for as_dir in $PATH
-do
- IFS=$as_save_IFS
- test -z "$as_dir" && as_dir=.
- for ac_exec_ext in '' $ac_executable_extensions; do
- if { test -f "$as_dir/$ac_word$ac_exec_ext" && $as_test_x "$as_dir/$ac_word$ac_exec_ext"; }; then
- ac_cv_prog_MAKEINFO="makeinfo"
- $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
- break 2
- fi
-done
- done
-IFS=$as_save_IFS
+# We never need to detect it in this sub-configure.
+# But preserve it for config.status --recheck.
-fi
-fi
-MAKEINFO=$ac_cv_prog_MAKEINFO
-if test -n "$MAKEINFO"; then
- { $as_echo "$as_me:${as_lineno-$LINENO}: result: $MAKEINFO" >&5
-$as_echo "$MAKEINFO" >&6; }
-else
- { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
-fi
-
-
-if test "x$MAKEINFO" = "x"; then
- as_fn_error "makeinfo is required for compilation" "$LINENO" 5
-else
- case "$MAKEINFO" in
- */missing\ makeinfo*)
- as_fn_error "makeinfo is required for compilation" "$LINENO" 5
- ;;
- esac
-fi
-
-
-# --split-size=5000000 may be already in $MAKEINFO from parent configure.
-# Re-running configure in gdb/ would lose it so ensure it stays present.
-MAKEINFOFLAGS=${MAKEINFOFLAGS---split-size=5000000}
MAKEINFO_EXTRA_FLAGS=""
@@ -11665,7 +11620,7 @@
sys/reg.h sys/debugreg.h sys/select.h sys/syscall.h \
sys/types.h sys/wait.h wait.h termios.h termio.h \
sgtty.h unistd.h elf_hp.h ctype.h time.h locale.h \
- dlfcn.h
+ dlfcn.h
do :
as_ac_Header=`$as_echo "ac_cv_header_$ac_header" | $as_tr_sh`
ac_fn_c_check_header_mongrel "$LINENO" "$ac_header" "$as_ac_Header" "$ac_includes_default"
diff --git a/gdb/configure.ac b/gdb/configure.ac
index 6a7af7e..2fc39ff 100644
--- a/gdb/configure.ac
+++ b/gdb/configure.ac
@@ -85,24 +85,12 @@
AC_DEFINE_UNQUOTED(PACKAGE, "$PACKAGE", [Name of this package. ])
AC_SUBST(PACKAGE)
-# Do we have a single-tree copy of texinfo? Even if we do, we can't
-# rely on it - libiberty is built before texinfo.
-AC_CHECK_PROG(MAKEINFO, makeinfo, makeinfo, )
-if test "x$MAKEINFO" = "x"; then
- AC_ERROR([makeinfo is required for compilation])
-else
- case "$MAKEINFO" in
- */missing\ makeinfo*)
- AC_ERROR([makeinfo is required for compilation])
- ;;
- esac
-fi
-AC_SUBST(MAKEINFO)
-
-# --split-size=5000000 may be already in $MAKEINFO from parent configure.
-# Re-running configure in gdb/ would lose it so ensure it stays present.
-MAKEINFOFLAGS=${MAKEINFOFLAGS---split-size=5000000}
-AC_SUBST(MAKEINFOFLAGS)
+# We never need to detect it in this sub-configure.
+# But preserve it for config.status --recheck.
+AC_ARG_VAR(MAKEINFO,
+ [Parent configure detects if it is of sufficient version.])
+AC_ARG_VAR(MAKEINFOFLAGS,
+ [Parameters for MAKEINFO.])
MAKEINFO_EXTRA_FLAGS=""
AC_CACHE_CHECK([whether $MAKEINFO supports @click], gdb_cv_have_makeinfo_click,
diff --git a/gdb/doc/gdb.info b/gdb/doc/gdb.info
index 22fd012..f61fc3d 100644
--- a/gdb/doc/gdb.info
+++ b/gdb/doc/gdb.info
Binary files differ
diff --git a/gdb/doc/gdb.info-1 b/gdb/doc/gdb.info-1
new file mode 100644
index 0000000..9c7c290
--- /dev/null
+++ b/gdb/doc/gdb.info-1
@@ -0,0 +1,7217 @@
+This is gdb.info, produced by makeinfo version 4.8 from ./gdb.texinfo.
+
+INFO-DIR-SECTION Software development
+START-INFO-DIR-ENTRY
+* Gdb: (gdb). The GNU debugger.
+END-INFO-DIR-ENTRY
+
+ Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996,
+1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009,
+2010 Free Software Foundation, Inc.
+
+ Permission is granted to copy, distribute and/or modify this document
+under the terms of the GNU Free Documentation License, Version 1.3 or
+any later version published by the Free Software Foundation; with the
+Invariant Sections being "Free Software" and "Free Software Needs Free
+Documentation", with the Front-Cover Texts being "A GNU Manual," and
+with the Back-Cover Texts as in (a) below.
+
+ (a) The FSF's Back-Cover Text is: "You are free to copy and modify
+this GNU Manual. Buying copies from GNU Press supports the FSF in
+developing GNU and promoting software freedom."
+
+ This file documents the GNU debugger GDB.
+
+ This is the Tenth Edition, of `Debugging with GDB: the GNU
+Source-Level Debugger' for GDB (GDB) Version 7.4.1.
+
+ Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996,
+1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009,
+2010 Free Software Foundation, Inc.
+
+ Permission is granted to copy, distribute and/or modify this document
+under the terms of the GNU Free Documentation License, Version 1.3 or
+any later version published by the Free Software Foundation; with the
+Invariant Sections being "Free Software" and "Free Software Needs Free
+Documentation", with the Front-Cover Texts being "A GNU Manual," and
+with the Back-Cover Texts as in (a) below.
+
+ (a) The FSF's Back-Cover Text is: "You are free to copy and modify
+this GNU Manual. Buying copies from GNU Press supports the FSF in
+developing GNU and promoting software freedom."
+
+
+File: gdb.info, Node: Top, Next: Summary, Prev: (dir), Up: (dir)
+
+Debugging with GDB
+******************
+
+This file describes GDB, the GNU symbolic debugger.
+
+ This is the Tenth Edition, for GDB (GDB) Version 7.4.1.
+
+ Copyright (C) 1988-2010 Free Software Foundation, Inc.
+
+ This edition of the GDB manual is dedicated to the memory of Fred
+Fish. Fred was a long-standing contributor to GDB and to Free software
+in general. We will miss him.
+
+* Menu:
+
+* Summary:: Summary of GDB
+* Sample Session:: A sample GDB session
+
+* Invocation:: Getting in and out of GDB
+* Commands:: GDB commands
+* Running:: Running programs under GDB
+* Stopping:: Stopping and continuing
+* Reverse Execution:: Running programs backward
+* Process Record and Replay:: Recording inferior's execution and replaying it
+* Stack:: Examining the stack
+* Source:: Examining source files
+* Data:: Examining data
+* Optimized Code:: Debugging optimized code
+* Macros:: Preprocessor Macros
+* Tracepoints:: Debugging remote targets non-intrusively
+* Overlays:: Debugging programs that use overlays
+
+* Languages:: Using GDB with different languages
+
+* Symbols:: Examining the symbol table
+* Altering:: Altering execution
+* GDB Files:: GDB files
+* Targets:: Specifying a debugging target
+* Remote Debugging:: Debugging remote programs
+* Configurations:: Configuration-specific information
+* Controlling GDB:: Controlling GDB
+* Extending GDB:: Extending GDB
+* Interpreters:: Command Interpreters
+* TUI:: GDB Text User Interface
+* Emacs:: Using GDB under GNU Emacs
+* GDB/MI:: GDB's Machine Interface.
+* Annotations:: GDB's annotation interface.
+* JIT Interface:: Using the JIT debugging interface.
+
+* GDB Bugs:: Reporting bugs in GDB
+
+
+* Command Line Editing:: Command Line Editing
+* Using History Interactively:: Using History Interactively
+* In Memoriam:: In Memoriam
+* Formatting Documentation:: How to format and print GDB documentation
+* Installing GDB:: Installing GDB
+* Maintenance Commands:: Maintenance Commands
+* Remote Protocol:: GDB Remote Serial Protocol
+* Agent Expressions:: The GDB Agent Expression Mechanism
+* Target Descriptions:: How targets can describe themselves to
+ GDB
+* Operating System Information:: Getting additional information from
+ the operating system
+* Trace File Format:: GDB trace file format
+* Index Section Format:: .gdb_index section format
+* Copying:: GNU General Public License says
+ how you can copy and share GDB
+* GNU Free Documentation License:: The license for this documentation
+* Index:: Index
+
+
+File: gdb.info, Node: Summary, Next: Sample Session, Prev: Top, Up: Top
+
+Summary of GDB
+**************
+
+The purpose of a debugger such as GDB is to allow you to see what is
+going on "inside" another program while it executes--or what another
+program was doing at the moment it crashed.
+
+ GDB can do four main kinds of things (plus other things in support of
+these) to help you catch bugs in the act:
+
+ * Start your program, specifying anything that might affect its
+ behavior.
+
+ * Make your program stop on specified conditions.
+
+ * Examine what has happened, when your program has stopped.
+
+ * Change things in your program, so you can experiment with
+ correcting the effects of one bug and go on to learn about another.
+
+ You can use GDB to debug programs written in C and C++. For more
+information, see *Note Supported Languages: Supported Languages. For
+more information, see *Note C and C++: C.
+
+ Support for D is partial. For information on D, see *Note D: D.
+
+ Support for Modula-2 is partial. For information on Modula-2, see
+*Note Modula-2: Modula-2.
+
+ Support for OpenCL C is partial. For information on OpenCL C, see
+*Note OpenCL C: OpenCL C.
+
+ Debugging Pascal programs which use sets, subranges, file variables,
+or nested functions does not currently work. GDB does not support
+entering expressions, printing values, or similar features using Pascal
+syntax.
+
+ GDB can be used to debug programs written in Fortran, although it
+may be necessary to refer to some variables with a trailing underscore.
+
+ GDB can be used to debug programs written in Objective-C, using
+either the Apple/NeXT or the GNU Objective-C runtime.
+
+* Menu:
+
+* Free Software:: Freely redistributable software
+* Contributors:: Contributors to GDB
+
+
+File: gdb.info, Node: Free Software, Next: Contributors, Up: Summary
+
+Free Software
+=============
+
+GDB is "free software", protected by the GNU General Public License
+(GPL). The GPL gives you the freedom to copy or adapt a licensed
+program--but every person getting a copy also gets with it the freedom
+to modify that copy (which means that they must get access to the
+source code), and the freedom to distribute further copies. Typical
+software companies use copyrights to limit your freedoms; the Free
+Software Foundation uses the GPL to preserve these freedoms.
+
+ Fundamentally, the General Public License is a license which says
+that you have these freedoms and that you cannot take these freedoms
+away from anyone else.
+
+Free Software Needs Free Documentation
+======================================
+
+The biggest deficiency in the free software community today is not in
+the software--it is the lack of good free documentation that we can
+include with the free software. Many of our most important programs do
+not come with free reference manuals and free introductory texts.
+Documentation is an essential part of any software package; when an
+important free software package does not come with a free manual and a
+free tutorial, that is a major gap. We have many such gaps today.
+
+ Consider Perl, for instance. The tutorial manuals that people
+normally use are non-free. How did this come about? Because the
+authors of those manuals published them with restrictive terms--no
+copying, no modification, source files not available--which exclude
+them from the free software world.
+
+ That wasn't the first time this sort of thing happened, and it was
+far from the last. Many times we have heard a GNU user eagerly
+describe a manual that he is writing, his intended contribution to the
+community, only to learn that he had ruined everything by signing a
+publication contract to make it non-free.
+
+ Free documentation, like free software, is a matter of freedom, not
+price. The problem with the non-free manual is not that publishers
+charge a price for printed copies--that in itself is fine. (The Free
+Software Foundation sells printed copies of manuals, too.) The problem
+is the restrictions on the use of the manual. Free manuals are
+available in source code form, and give you permission to copy and
+modify. Non-free manuals do not allow this.
+
+ The criteria of freedom for a free manual are roughly the same as for
+free software. Redistribution (including the normal kinds of
+commercial redistribution) must be permitted, so that the manual can
+accompany every copy of the program, both on-line and on paper.
+
+ Permission for modification of the technical content is crucial too.
+When people modify the software, adding or changing features, if they
+are conscientious they will change the manual too--so they can provide
+accurate and clear documentation for the modified program. A manual
+that leaves you no choice but to write a new manual to document a
+changed version of the program is not really available to our community.
+
+ Some kinds of limits on the way modification is handled are
+acceptable. For example, requirements to preserve the original
+author's copyright notice, the distribution terms, or the list of
+authors, are ok. It is also no problem to require modified versions to
+include notice that they were modified. Even entire sections that may
+not be deleted or changed are acceptable, as long as they deal with
+nontechnical topics (like this one). These kinds of restrictions are
+acceptable because they don't obstruct the community's normal use of
+the manual.
+
+ However, it must be possible to modify all the _technical_ content
+of the manual, and then distribute the result in all the usual media,
+through all the usual channels. Otherwise, the restrictions obstruct
+the use of the manual, it is not free, and we need another manual to
+replace it.
+
+ Please spread the word about this issue. Our community continues to
+lose manuals to proprietary publishing. If we spread the word that
+free software needs free reference manuals and free tutorials, perhaps
+the next person who wants to contribute by writing documentation will
+realize, before it is too late, that only free manuals contribute to
+the free software community.
+
+ If you are writing documentation, please insist on publishing it
+under the GNU Free Documentation License or another free documentation
+license. Remember that this decision requires your approval--you don't
+have to let the publisher decide. Some commercial publishers will use
+a free license if you insist, but they will not propose the option; it
+is up to you to raise the issue and say firmly that this is what you
+want. If the publisher you are dealing with refuses, please try other
+publishers. If you're not sure whether a proposed license is free,
+write to <licensing@gnu.org>.
+
+ You can encourage commercial publishers to sell more free, copylefted
+manuals and tutorials by buying them, and particularly by buying copies
+from the publishers that paid for their writing or for major
+improvements. Meanwhile, try to avoid buying non-free documentation at
+all. Check the distribution terms of a manual before you buy it, and
+insist that whoever seeks your business must respect your freedom.
+Check the history of the book, and try to reward the publishers that
+have paid or pay the authors to work on it.
+
+ The Free Software Foundation maintains a list of free documentation
+published by other publishers, at
+`http://www.fsf.org/doc/other-free-books.html'.
+
+
+File: gdb.info, Node: Contributors, Prev: Free Software, Up: Summary
+
+Contributors to GDB
+===================
+
+Richard Stallman was the original author of GDB, and of many other GNU
+programs. Many others have contributed to its development. This
+section attempts to credit major contributors. One of the virtues of
+free software is that everyone is free to contribute to it; with
+regret, we cannot actually acknowledge everyone here. The file
+`ChangeLog' in the GDB distribution approximates a blow-by-blow account.
+
+ Changes much prior to version 2.0 are lost in the mists of time.
+
+ _Plea:_ Additions to this section are particularly welcome. If you
+ or your friends (or enemies, to be evenhanded) have been unfairly
+ omitted from this list, we would like to add your names!
+
+ So that they may not regard their many labors as thankless, we
+particularly thank those who shepherded GDB through major releases:
+Andrew Cagney (releases 6.3, 6.2, 6.1, 6.0, 5.3, 5.2, 5.1 and 5.0); Jim
+Blandy (release 4.18); Jason Molenda (release 4.17); Stan Shebs
+(release 4.14); Fred Fish (releases 4.16, 4.15, 4.13, 4.12, 4.11, 4.10,
+and 4.9); Stu Grossman and John Gilmore (releases 4.8, 4.7, 4.6, 4.5,
+and 4.4); John Gilmore (releases 4.3, 4.2, 4.1, 4.0, and 3.9); Jim
+Kingdon (releases 3.5, 3.4, and 3.3); and Randy Smith (releases 3.2,
+3.1, and 3.0).
+
+ Richard Stallman, assisted at various times by Peter TerMaat, Chris
+Hanson, and Richard Mlynarik, handled releases through 2.8.
+
+ Michael Tiemann is the author of most of the GNU C++ support in GDB,
+with significant additional contributions from Per Bothner and Daniel
+Berlin. James Clark wrote the GNU C++ demangler. Early work on C++
+was by Peter TerMaat (who also did much general update work leading to
+release 3.0).
+
+ GDB uses the BFD subroutine library to examine multiple object-file
+formats; BFD was a joint project of David V. Henkel-Wallace, Rich
+Pixley, Steve Chamberlain, and John Gilmore.
+
+ David Johnson wrote the original COFF support; Pace Willison did the
+original support for encapsulated COFF.
+
+ Brent Benson of Harris Computer Systems contributed DWARF 2 support.
+
+ Adam de Boor and Bradley Davis contributed the ISI Optimum V support.
+Per Bothner, Noboyuki Hikichi, and Alessandro Forin contributed MIPS
+support. Jean-Daniel Fekete contributed Sun 386i support. Chris
+Hanson improved the HP9000 support. Noboyuki Hikichi and Tomoyuki
+Hasei contributed Sony/News OS 3 support. David Johnson contributed
+Encore Umax support. Jyrki Kuoppala contributed Altos 3068 support.
+Jeff Law contributed HP PA and SOM support. Keith Packard contributed
+NS32K support. Doug Rabson contributed Acorn Risc Machine support.
+Bob Rusk contributed Harris Nighthawk CX-UX support. Chris Smith
+contributed Convex support (and Fortran debugging). Jonathan Stone
+contributed Pyramid support. Michael Tiemann contributed SPARC support.
+Tim Tucker contributed support for the Gould NP1 and Gould Powernode.
+Pace Willison contributed Intel 386 support. Jay Vosburgh contributed
+Symmetry support. Marko Mlinar contributed OpenRISC 1000 support.
+
+ Andreas Schwab contributed M68K GNU/Linux support.
+
+ Rich Schaefer and Peter Schauer helped with support of SunOS shared
+libraries.
+
+ Jay Fenlason and Roland McGrath ensured that GDB and GAS agree about
+several machine instruction sets.
+
+ Patrick Duval, Ted Goldstein, Vikram Koka and Glenn Engel helped
+develop remote debugging. Intel Corporation, Wind River Systems, AMD,
+and ARM contributed remote debugging modules for the i960, VxWorks,
+A29K UDI, and RDI targets, respectively.
+
+ Brian Fox is the author of the readline libraries providing
+command-line editing and command history.
+
+ Andrew Beers of SUNY Buffalo wrote the language-switching code, the
+Modula-2 support, and contributed the Languages chapter of this manual.
+
+ Fred Fish wrote most of the support for Unix System Vr4. He also
+enhanced the command-completion support to cover C++ overloaded symbols.
+
+ Hitachi America (now Renesas America), Ltd. sponsored the support for
+H8/300, H8/500, and Super-H processors.
+
+ NEC sponsored the support for the v850, Vr4xxx, and Vr5xxx
+processors.
+
+ Mitsubishi (now Renesas) sponsored the support for D10V, D30V, and
+M32R/D processors.
+
+ Toshiba sponsored the support for the TX39 Mips processor.
+
+ Matsushita sponsored the support for the MN10200 and MN10300
+processors.
+
+ Fujitsu sponsored the support for SPARClite and FR30 processors.
+
+ Kung Hsu, Jeff Law, and Rick Sladkey added support for hardware
+watchpoints.
+
+ Michael Snyder added support for tracepoints.
+
+ Stu Grossman wrote gdbserver.
+
+ Jim Kingdon, Peter Schauer, Ian Taylor, and Stu Grossman made nearly
+innumerable bug fixes and cleanups throughout GDB.
+
+ The following people at the Hewlett-Packard Company contributed
+support for the PA-RISC 2.0 architecture, HP-UX 10.20, 10.30, and 11.0
+(narrow mode), HP's implementation of kernel threads, HP's aC++
+compiler, and the Text User Interface (nee Terminal User Interface):
+Ben Krepp, Richard Title, John Bishop, Susan Macchia, Kathy Mann,
+Satish Pai, India Paul, Steve Rehrauer, and Elena Zannoni. Kim Haase
+provided HP-specific information in this manual.
+
+ DJ Delorie ported GDB to MS-DOS, for the DJGPP project. Robert
+Hoehne made significant contributions to the DJGPP port.
+
+ Cygnus Solutions has sponsored GDB maintenance and much of its
+development since 1991. Cygnus engineers who have worked on GDB
+fulltime include Mark Alexander, Jim Blandy, Per Bothner, Kevin
+Buettner, Edith Epstein, Chris Faylor, Fred Fish, Martin Hunt, Jim
+Ingham, John Gilmore, Stu Grossman, Kung Hsu, Jim Kingdon, John Metzler,
+Fernando Nasser, Geoffrey Noer, Dawn Perchik, Rich Pixley, Zdenek
+Radouch, Keith Seitz, Stan Shebs, David Taylor, and Elena Zannoni. In
+addition, Dave Brolley, Ian Carmichael, Steve Chamberlain, Nick Clifton,
+JT Conklin, Stan Cox, DJ Delorie, Ulrich Drepper, Frank Eigler, Doug
+Evans, Sean Fagan, David Henkel-Wallace, Richard Henderson, Jeff
+Holcomb, Jeff Law, Jim Lemke, Tom Lord, Bob Manson, Michael Meissner,
+Jason Merrill, Catherine Moore, Drew Moseley, Ken Raeburn, Gavin
+Romig-Koch, Rob Savoye, Jamie Smith, Mike Stump, Ian Taylor, Angela
+Thomas, Michael Tiemann, Tom Tromey, Ron Unrau, Jim Wilson, and David
+Zuhn have made contributions both large and small.
+
+ Andrew Cagney, Fernando Nasser, and Elena Zannoni, while working for
+Cygnus Solutions, implemented the original GDB/MI interface.
+
+ Jim Blandy added support for preprocessor macros, while working for
+Red Hat.
+
+ Andrew Cagney designed GDB's architecture vector. Many people
+including Andrew Cagney, Stephane Carrez, Randolph Chung, Nick Duffek,
+Richard Henderson, Mark Kettenis, Grace Sainsbury, Kei Sakamoto,
+Yoshinori Sato, Michael Snyder, Andreas Schwab, Jason Thorpe, Corinna
+Vinschen, Ulrich Weigand, and Elena Zannoni, helped with the migration
+of old architectures to this new framework.
+
+ Andrew Cagney completely re-designed and re-implemented GDB's
+unwinder framework, this consisting of a fresh new design featuring
+frame IDs, independent frame sniffers, and the sentinel frame. Mark
+Kettenis implemented the DWARF 2 unwinder, Jeff Johnston the libunwind
+unwinder, and Andrew Cagney the dummy, sentinel, tramp, and trad
+unwinders. The architecture-specific changes, each involving a
+complete rewrite of the architecture's frame code, were carried out by
+Jim Blandy, Joel Brobecker, Kevin Buettner, Andrew Cagney, Stephane
+Carrez, Randolph Chung, Orjan Friberg, Richard Henderson, Daniel
+Jacobowitz, Jeff Johnston, Mark Kettenis, Theodore A. Roth, Kei
+Sakamoto, Yoshinori Sato, Michael Snyder, Corinna Vinschen, and Ulrich
+Weigand.
+
+ Christian Zankel, Ross Morley, Bob Wilson, and Maxim Grigoriev from
+Tensilica, Inc. contributed support for Xtensa processors. Others who
+have worked on the Xtensa port of GDB in the past include Steve Tjiang,
+John Newlin, and Scott Foehner.
+
+ Michael Eager and staff of Xilinx, Inc., contributed support for the
+Xilinx MicroBlaze architecture.
+
+
+File: gdb.info, Node: Sample Session, Next: Invocation, Prev: Summary, Up: Top
+
+1 A Sample GDB Session
+**********************
+
+You can use this manual at your leisure to read all about GDB.
+However, a handful of commands are enough to get started using the
+debugger. This chapter illustrates those commands.
+
+ One of the preliminary versions of GNU `m4' (a generic macro
+processor) exhibits the following bug: sometimes, when we change its
+quote strings from the default, the commands used to capture one macro
+definition within another stop working. In the following short `m4'
+session, we define a macro `foo' which expands to `0000'; we then use
+the `m4' built-in `defn' to define `bar' as the same thing. However,
+when we change the open quote string to `<QUOTE>' and the close quote
+string to `<UNQUOTE>', the same procedure fails to define a new synonym
+`baz':
+
+ $ cd gnu/m4
+ $ ./m4
+ define(foo,0000)
+
+ foo
+ 0000
+ define(bar,defn(`foo'))
+
+ bar
+ 0000
+ changequote(<QUOTE>,<UNQUOTE>)
+
+ define(baz,defn(<QUOTE>foo<UNQUOTE>))
+ baz
+ Ctrl-d
+ m4: End of input: 0: fatal error: EOF in string
+
+Let us use GDB to try to see what is going on.
+
+ $ gdb m4
+ GDB is free software and you are welcome to distribute copies
+ of it under certain conditions; type "show copying" to see
+ the conditions.
+ There is absolutely no warranty for GDB; type "show warranty"
+ for details.
+
+ GDB 7.4.1, Copyright 1999 Free Software Foundation, Inc...
+ (gdb)
+
+GDB reads only enough symbol data to know where to find the rest when
+needed; as a result, the first prompt comes up very quickly. We now
+tell GDB to use a narrower display width than usual, so that examples
+fit in this manual.
+
+ (gdb) set width 70
+
+We need to see how the `m4' built-in `changequote' works. Having
+looked at the source, we know the relevant subroutine is
+`m4_changequote', so we set a breakpoint there with the GDB `break'
+command.
+
+ (gdb) break m4_changequote
+ Breakpoint 1 at 0x62f4: file builtin.c, line 879.
+
+Using the `run' command, we start `m4' running under GDB control; as
+long as control does not reach the `m4_changequote' subroutine, the
+program runs as usual:
+
+ (gdb) run
+ Starting program: /work/Editorial/gdb/gnu/m4/m4
+ define(foo,0000)
+
+ foo
+ 0000
+
+To trigger the breakpoint, we call `changequote'. GDB suspends
+execution of `m4', displaying information about the context where it
+stops.
+
+ changequote(<QUOTE>,<UNQUOTE>)
+
+ Breakpoint 1, m4_changequote (argc=3, argv=0x33c70)
+ at builtin.c:879
+ 879 if (bad_argc(TOKEN_DATA_TEXT(argv[0]),argc,1,3))
+
+Now we use the command `n' (`next') to advance execution to the next
+line of the current function.
+
+ (gdb) n
+ 882 set_quotes((argc >= 2) ? TOKEN_DATA_TEXT(argv[1])\
+ : nil,
+
+`set_quotes' looks like a promising subroutine. We can go into it by
+using the command `s' (`step') instead of `next'. `step' goes to the
+next line to be executed in _any_ subroutine, so it steps into
+`set_quotes'.
+
+ (gdb) s
+ set_quotes (lq=0x34c78 "<QUOTE>", rq=0x34c88 "<UNQUOTE>")
+ at input.c:530
+ 530 if (lquote != def_lquote)
+
+The display that shows the subroutine where `m4' is now suspended (and
+its arguments) is called a stack frame display. It shows a summary of
+the stack. We can use the `backtrace' command (which can also be
+spelled `bt'), to see where we are in the stack as a whole: the
+`backtrace' command displays a stack frame for each active subroutine.
+
+ (gdb) bt
+ #0 set_quotes (lq=0x34c78 "<QUOTE>", rq=0x34c88 "<UNQUOTE>")
+ at input.c:530
+ #1 0x6344 in m4_changequote (argc=3, argv=0x33c70)
+ at builtin.c:882
+ #2 0x8174 in expand_macro (sym=0x33320) at macro.c:242
+ #3 0x7a88 in expand_token (obs=0x0, t=209696, td=0xf7fffa30)
+ at macro.c:71
+ #4 0x79dc in expand_input () at macro.c:40
+ #5 0x2930 in main (argc=0, argv=0xf7fffb20) at m4.c:195
+
+We step through a few more lines to see what happens. The first two
+times, we can use `s'; the next two times we use `n' to avoid falling
+into the `xstrdup' subroutine.
+
+ (gdb) s
+ 0x3b5c 532 if (rquote != def_rquote)
+ (gdb) s
+ 0x3b80 535 lquote = (lq == nil || *lq == '\0') ? \
+ def_lquote : xstrdup(lq);
+ (gdb) n
+ 536 rquote = (rq == nil || *rq == '\0') ? def_rquote\
+ : xstrdup(rq);
+ (gdb) n
+ 538 len_lquote = strlen(rquote);
+
+The last line displayed looks a little odd; we can examine the variables
+`lquote' and `rquote' to see if they are in fact the new left and right
+quotes we specified. We use the command `p' (`print') to see their
+values.
+
+ (gdb) p lquote
+ $1 = 0x35d40 "<QUOTE>"
+ (gdb) p rquote
+ $2 = 0x35d50 "<UNQUOTE>"
+
+`lquote' and `rquote' are indeed the new left and right quotes. To
+look at some context, we can display ten lines of source surrounding
+the current line with the `l' (`list') command.
+
+ (gdb) l
+ 533 xfree(rquote);
+ 534
+ 535 lquote = (lq == nil || *lq == '\0') ? def_lquote\
+ : xstrdup (lq);
+ 536 rquote = (rq == nil || *rq == '\0') ? def_rquote\
+ : xstrdup (rq);
+ 537
+ 538 len_lquote = strlen(rquote);
+ 539 len_rquote = strlen(lquote);
+ 540 }
+ 541
+ 542 void
+
+Let us step past the two lines that set `len_lquote' and `len_rquote',
+and then examine the values of those variables.
+
+ (gdb) n
+ 539 len_rquote = strlen(lquote);
+ (gdb) n
+ 540 }
+ (gdb) p len_lquote
+ $3 = 9
+ (gdb) p len_rquote
+ $4 = 7
+
+That certainly looks wrong, assuming `len_lquote' and `len_rquote' are
+meant to be the lengths of `lquote' and `rquote' respectively. We can
+set them to better values using the `p' command, since it can print the
+value of any expression--and that expression can include subroutine
+calls and assignments.
+
+ (gdb) p len_lquote=strlen(lquote)
+ $5 = 7
+ (gdb) p len_rquote=strlen(rquote)
+ $6 = 9
+
+Is that enough to fix the problem of using the new quotes with the `m4'
+built-in `defn'? We can allow `m4' to continue executing with the `c'
+(`continue') command, and then try the example that caused trouble
+initially:
+
+ (gdb) c
+ Continuing.
+
+ define(baz,defn(<QUOTE>foo<UNQUOTE>))
+
+ baz
+ 0000
+
+Success! The new quotes now work just as well as the default ones. The
+problem seems to have been just the two typos defining the wrong
+lengths. We allow `m4' exit by giving it an EOF as input:
+
+ Ctrl-d
+ Program exited normally.
+
+The message `Program exited normally.' is from GDB; it indicates `m4'
+has finished executing. We can end our GDB session with the GDB `quit'
+command.
+
+ (gdb) quit
+
+
+File: gdb.info, Node: Invocation, Next: Commands, Prev: Sample Session, Up: Top
+
+2 Getting In and Out of GDB
+***************************
+
+This chapter discusses how to start GDB, and how to get out of it. The
+essentials are:
+ * type `gdb' to start GDB.
+
+ * type `quit' or `Ctrl-d' to exit.
+
+* Menu:
+
+* Invoking GDB:: How to start GDB
+* Quitting GDB:: How to quit GDB
+* Shell Commands:: How to use shell commands inside GDB
+* Logging Output:: How to log GDB's output to a file
+
+
+File: gdb.info, Node: Invoking GDB, Next: Quitting GDB, Up: Invocation
+
+2.1 Invoking GDB
+================
+
+Invoke GDB by running the program `gdb'. Once started, GDB reads
+commands from the terminal until you tell it to exit.
+
+ You can also run `gdb' with a variety of arguments and options, to
+specify more of your debugging environment at the outset.
+
+ The command-line options described here are designed to cover a
+variety of situations; in some environments, some of these options may
+effectively be unavailable.
+
+ The most usual way to start GDB is with one argument, specifying an
+executable program:
+
+ gdb PROGRAM
+
+You can also start with both an executable program and a core file
+specified:
+
+ gdb PROGRAM CORE
+
+ You can, instead, specify a process ID as a second argument, if you
+want to debug a running process:
+
+ gdb PROGRAM 1234
+
+would attach GDB to process `1234' (unless you also have a file named
+`1234'; GDB does check for a core file first).
+
+ Taking advantage of the second command-line argument requires a
+fairly complete operating system; when you use GDB as a remote debugger
+attached to a bare board, there may not be any notion of "process", and
+there is often no way to get a core dump. GDB will warn you if it is
+unable to attach or to read core dumps.
+
+ You can optionally have `gdb' pass any arguments after the
+executable file to the inferior using `--args'. This option stops
+option processing.
+ gdb --args gcc -O2 -c foo.c
+ This will cause `gdb' to debug `gcc', and to set `gcc''s
+command-line arguments (*note Arguments::) to `-O2 -c foo.c'.
+
+ You can run `gdb' without printing the front material, which
+describes GDB's non-warranty, by specifying `-silent':
+
+ gdb -silent
+
+You can further control how GDB starts up by using command-line
+options. GDB itself can remind you of the options available.
+
+Type
+
+ gdb -help
+
+to display all available options and briefly describe their use (`gdb
+-h' is a shorter equivalent).
+
+ All options and command line arguments you give are processed in
+sequential order. The order makes a difference when the `-x' option is
+used.
+
+* Menu:
+
+* File Options:: Choosing files
+* Mode Options:: Choosing modes
+* Startup:: What GDB does during startup
+
+
+File: gdb.info, Node: File Options, Next: Mode Options, Up: Invoking GDB
+
+2.1.1 Choosing Files
+--------------------
+
+When GDB starts, it reads any arguments other than options as
+specifying an executable file and core file (or process ID). This is
+the same as if the arguments were specified by the `-se' and `-c' (or
+`-p') options respectively. (GDB reads the first argument that does
+not have an associated option flag as equivalent to the `-se' option
+followed by that argument; and the second argument that does not have
+an associated option flag, if any, as equivalent to the `-c'/`-p'
+option followed by that argument.) If the second argument begins with
+a decimal digit, GDB will first attempt to attach to it as a process,
+and if that fails, attempt to open it as a corefile. If you have a
+corefile whose name begins with a digit, you can prevent GDB from
+treating it as a pid by prefixing it with `./', e.g. `./12345'.
+
+ If GDB has not been configured to included core file support, such
+as for most embedded targets, then it will complain about a second
+argument and ignore it.
+
+ Many options have both long and short forms; both are shown in the
+following list. GDB also recognizes the long forms if you truncate
+them, so long as enough of the option is present to be unambiguous.
+(If you prefer, you can flag option arguments with `--' rather than
+`-', though we illustrate the more usual convention.)
+
+`-symbols FILE'
+`-s FILE'
+ Read symbol table from file FILE.
+
+`-exec FILE'
+`-e FILE'
+ Use file FILE as the executable file to execute when appropriate,
+ and for examining pure data in conjunction with a core dump.
+
+`-se FILE'
+ Read symbol table from file FILE and use it as the executable file.
+
+`-core FILE'
+`-c FILE'
+ Use file FILE as a core dump to examine.
+
+`-pid NUMBER'
+`-p NUMBER'
+ Connect to process ID NUMBER, as with the `attach' command.
+
+`-command FILE'
+`-x FILE'
+ Execute commands from file FILE. The contents of this file is
+ evaluated exactly as the `source' command would. *Note Command
+ files: Command Files.
+
+`-eval-command COMMAND'
+`-ex COMMAND'
+ Execute a single GDB command.
+
+ This option may be used multiple times to call multiple commands.
+ It may also be interleaved with `-command' as required.
+
+ gdb -ex 'target sim' -ex 'load' \
+ -x setbreakpoints -ex 'run' a.out
+
+`-directory DIRECTORY'
+`-d DIRECTORY'
+ Add DIRECTORY to the path to search for source and script files.
+
+`-r'
+`-readnow'
+ Read each symbol file's entire symbol table immediately, rather
+ than the default, which is to read it incrementally as it is
+ needed. This makes startup slower, but makes future operations
+ faster.
+
+
+
+File: gdb.info, Node: Mode Options, Next: Startup, Prev: File Options, Up: Invoking GDB
+
+2.1.2 Choosing Modes
+--------------------
+
+You can run GDB in various alternative modes--for example, in batch
+mode or quiet mode.
+
+`-nx'
+`-n'
+ Do not execute commands found in any initialization files.
+ Normally, GDB executes the commands in these files after all the
+ command options and arguments have been processed. *Note Command
+ Files: Command Files.
+
+`-quiet'
+`-silent'
+`-q'
+ "Quiet". Do not print the introductory and copyright messages.
+ These messages are also suppressed in batch mode.
+
+`-batch'
+ Run in batch mode. Exit with status `0' after processing all the
+ command files specified with `-x' (and all commands from
+ initialization files, if not inhibited with `-n'). Exit with
+ nonzero status if an error occurs in executing the GDB commands in
+ the command files. Batch mode also disables pagination, sets
+ unlimited terminal width and height *note Screen Size::, and acts
+ as if `set confirm off' were in effect (*note Messages/Warnings::).
+
+ Batch mode may be useful for running GDB as a filter, for example
+ to download and run a program on another computer; in order to
+ make this more useful, the message
+
+ Program exited normally.
+
+ (which is ordinarily issued whenever a program running under GDB
+ control terminates) is not issued when running in batch mode.
+
+`-batch-silent'
+ Run in batch mode exactly like `-batch', but totally silently. All
+ GDB output to `stdout' is prevented (`stderr' is unaffected).
+ This is much quieter than `-silent' and would be useless for an
+ interactive session.
+
+ This is particularly useful when using targets that give `Loading
+ section' messages, for example.
+
+ Note that targets that give their output via GDB, as opposed to
+ writing directly to `stdout', will also be made silent.
+
+`-return-child-result'
+ The return code from GDB will be the return code from the child
+ process (the process being debugged), with the following
+ exceptions:
+
+ * GDB exits abnormally. E.g., due to an incorrect argument or
+ an internal error. In this case the exit code is the same as
+ it would have been without `-return-child-result'.
+
+ * The user quits with an explicit value. E.g., `quit 1'.
+
+ * The child process never runs, or is not allowed to terminate,
+ in which case the exit code will be -1.
+
+ This option is useful in conjunction with `-batch' or
+ `-batch-silent', when GDB is being used as a remote program loader
+ or simulator interface.
+
+`-nowindows'
+`-nw'
+ "No windows". If GDB comes with a graphical user interface (GUI)
+ built in, then this option tells GDB to only use the command-line
+ interface. If no GUI is available, this option has no effect.
+
+`-windows'
+`-w'
+ If GDB includes a GUI, then this option requires it to be used if
+ possible.
+
+`-cd DIRECTORY'
+ Run GDB using DIRECTORY as its working directory, instead of the
+ current directory.
+
+`-data-directory DIRECTORY'
+ Run GDB using DIRECTORY as its data directory. The data directory
+ is where GDB searches for its auxiliary files. *Note Data Files::.
+
+`-fullname'
+`-f'
+ GNU Emacs sets this option when it runs GDB as a subprocess. It
+ tells GDB to output the full file name and line number in a
+ standard, recognizable fashion each time a stack frame is
+ displayed (which includes each time your program stops). This
+ recognizable format looks like two `\032' characters, followed by
+ the file name, line number and character position separated by
+ colons, and a newline. The Emacs-to-GDB interface program uses
+ the two `\032' characters as a signal to display the source code
+ for the frame.
+
+`-epoch'
+ The Epoch Emacs-GDB interface sets this option when it runs GDB as
+ a subprocess. It tells GDB to modify its print routines so as to
+ allow Epoch to display values of expressions in a separate window.
+
+`-annotate LEVEL'
+ This option sets the "annotation level" inside GDB. Its effect is
+ identical to using `set annotate LEVEL' (*note Annotations::).
+ The annotation LEVEL controls how much information GDB prints
+ together with its prompt, values of expressions, source lines, and
+ other types of output. Level 0 is the normal, level 1 is for use
+ when GDB is run as a subprocess of GNU Emacs, level 3 is the
+ maximum annotation suitable for programs that control GDB, and
+ level 2 has been deprecated.
+
+ The annotation mechanism has largely been superseded by GDB/MI
+ (*note GDB/MI::).
+
+`--args'
+ Change interpretation of command line so that arguments following
+ the executable file are passed as command line arguments to the
+ inferior. This option stops option processing.
+
+`-baud BPS'
+`-b BPS'
+ Set the line speed (baud rate or bits per second) of any serial
+ interface used by GDB for remote debugging.
+
+`-l TIMEOUT'
+ Set the timeout (in seconds) of any communication used by GDB for
+ remote debugging.
+
+`-tty DEVICE'
+`-t DEVICE'
+ Run using DEVICE for your program's standard input and output.
+
+`-tui'
+ Activate the "Text User Interface" when starting. The Text User
+ Interface manages several text windows on the terminal, showing
+ source, assembly, registers and GDB command outputs (*note GDB
+ Text User Interface: TUI.). Alternatively, the Text User
+ Interface can be enabled by invoking the program `gdbtui'. Do not
+ use this option if you run GDB from Emacs (*note Using GDB under
+ GNU Emacs: Emacs.).
+
+`-interpreter INTERP'
+ Use the interpreter INTERP for interface with the controlling
+ program or device. This option is meant to be set by programs
+ which communicate with GDB using it as a back end. *Note Command
+ Interpreters: Interpreters.
+
+ `--interpreter=mi' (or `--interpreter=mi2') causes GDB to use the
+ "GDB/MI interface" (*note The GDB/MI Interface: GDB/MI.) included
+ since GDB version 6.0. The previous GDB/MI interface, included in
+ GDB version 5.3 and selected with `--interpreter=mi1', is
+ deprecated. Earlier GDB/MI interfaces are no longer supported.
+
+`-write'
+ Open the executable and core files for both reading and writing.
+ This is equivalent to the `set write on' command inside GDB (*note
+ Patching::).
+
+`-statistics'
+ This option causes GDB to print statistics about time and memory
+ usage after it completes each command and returns to the prompt.
+
+`-version'
+ This option causes GDB to print its version number and no-warranty
+ blurb, and exit.
+
+
+
+File: gdb.info, Node: Startup, Prev: Mode Options, Up: Invoking GDB
+
+2.1.3 What GDB Does During Startup
+----------------------------------
+
+Here's the description of what GDB does during session startup:
+
+ 1. Sets up the command interpreter as specified by the command line
+ (*note interpreter: Mode Options.).
+
+ 2. Reads the system-wide "init file" (if `--with-system-gdbinit' was
+ used when building GDB; *note System-wide configuration and
+ settings: System-wide configuration.) and executes all the
+ commands in that file.
+
+ 3. Reads the init file (if any) in your home directory(1) and
+ executes all the commands in that file.
+
+ 4. Processes command line options and operands.
+
+ 5. Reads and executes the commands from init file (if any) in the
+ current working directory. This is only done if the current
+ directory is different from your home directory. Thus, you can
+ have more than one init file, one generic in your home directory,
+ and another, specific to the program you are debugging, in the
+ directory where you invoke GDB.
+
+ 6. If the command line specified a program to debug, or a process to
+ attach to, or a core file, GDB loads any auto-loaded scripts
+ provided for the program or for its loaded shared libraries.
+ *Note Auto-loading::.
+
+ If you wish to disable the auto-loading during startup, you must
+ do something like the following:
+
+ $ gdb -ex "set auto-load-scripts off" -ex "file myprogram"
+
+ The following does not work because the auto-loading is turned off
+ too late:
+
+ $ gdb -ex "set auto-load-scripts off" myprogram
+
+ 7. Reads command files specified by the `-x' option. *Note Command
+ Files::, for more details about GDB command files.
+
+ 8. Reads the command history recorded in the "history file". *Note
+ Command History::, for more details about the command history and
+ the files where GDB records it.
+
+ Init files use the same syntax as "command files" (*note Command
+Files::) and are processed by GDB in the same way. The init file in
+your home directory can set options (such as `set complaints') that
+affect subsequent processing of command line options and operands.
+Init files are not executed if you use the `-nx' option (*note Choosing
+Modes: Mode Options.).
+
+ To display the list of init files loaded by gdb at startup, you can
+use `gdb --help'.
+
+ The GDB init files are normally called `.gdbinit'. The DJGPP port
+of GDB uses the name `gdb.ini', due to the limitations of file names
+imposed by DOS filesystems. The Windows ports of GDB use the standard
+name, but if they find a `gdb.ini' file, they warn you about that and
+suggest to rename the file to the standard name.
+
+ ---------- Footnotes ----------
+
+ (1) On DOS/Windows systems, the home directory is the one pointed to
+by the `HOME' environment variable.
+
+
+File: gdb.info, Node: Quitting GDB, Next: Shell Commands, Prev: Invoking GDB, Up: Invocation
+
+2.2 Quitting GDB
+================
+
+`quit [EXPRESSION]'
+`q'
+ To exit GDB, use the `quit' command (abbreviated `q'), or type an
+ end-of-file character (usually `Ctrl-d'). If you do not supply
+ EXPRESSION, GDB will terminate normally; otherwise it will
+ terminate using the result of EXPRESSION as the error code.
+
+ An interrupt (often `Ctrl-c') does not exit from GDB, but rather
+terminates the action of any GDB command that is in progress and
+returns to GDB command level. It is safe to type the interrupt
+character at any time because GDB does not allow it to take effect
+until a time when it is safe.
+
+ If you have been using GDB to control an attached process or device,
+you can release it with the `detach' command (*note Debugging an
+Already-running Process: Attach.).
+
+
+File: gdb.info, Node: Shell Commands, Next: Logging Output, Prev: Quitting GDB, Up: Invocation
+
+2.3 Shell Commands
+==================
+
+If you need to execute occasional shell commands during your debugging
+session, there is no need to leave or suspend GDB; you can just use the
+`shell' command.
+
+`shell COMMAND-STRING'
+`!COMMAND-STRING'
+ Invoke a standard shell to execute COMMAND-STRING. Note that no
+ space is needed between `!' and COMMAND-STRING. If it exists, the
+ environment variable `SHELL' determines which shell to run.
+ Otherwise GDB uses the default shell (`/bin/sh' on Unix systems,
+ `COMMAND.COM' on MS-DOS, etc.).
+
+ The utility `make' is often needed in development environments. You
+do not have to use the `shell' command for this purpose in GDB:
+
+`make MAKE-ARGS'
+ Execute the `make' program with the specified arguments. This is
+ equivalent to `shell make MAKE-ARGS'.
+
+
+File: gdb.info, Node: Logging Output, Prev: Shell Commands, Up: Invocation
+
+2.4 Logging Output
+==================
+
+You may want to save the output of GDB commands to a file. There are
+several commands to control GDB's logging.
+
+`set logging on'
+ Enable logging.
+
+`set logging off'
+ Disable logging.
+
+`set logging file FILE'
+ Change the name of the current logfile. The default logfile is
+ `gdb.txt'.
+
+`set logging overwrite [on|off]'
+ By default, GDB will append to the logfile. Set `overwrite' if
+ you want `set logging on' to overwrite the logfile instead.
+
+`set logging redirect [on|off]'
+ By default, GDB output will go to both the terminal and the
+ logfile. Set `redirect' if you want output to go only to the log
+ file.
+
+`show logging'
+ Show the current values of the logging settings.
+
+
+File: gdb.info, Node: Commands, Next: Running, Prev: Invocation, Up: Top
+
+3 GDB Commands
+**************
+
+You can abbreviate a GDB command to the first few letters of the command
+name, if that abbreviation is unambiguous; and you can repeat certain
+GDB commands by typing just <RET>. You can also use the <TAB> key to
+get GDB to fill out the rest of a word in a command (or to show you the
+alternatives available, if there is more than one possibility).
+
+* Menu:
+
+* Command Syntax:: How to give commands to GDB
+* Completion:: Command completion
+* Help:: How to ask GDB for help
+
+
+File: gdb.info, Node: Command Syntax, Next: Completion, Up: Commands
+
+3.1 Command Syntax
+==================
+
+A GDB command is a single line of input. There is no limit on how long
+it can be. It starts with a command name, which is followed by
+arguments whose meaning depends on the command name. For example, the
+command `step' accepts an argument which is the number of times to
+step, as in `step 5'. You can also use the `step' command with no
+arguments. Some commands do not allow any arguments.
+
+ GDB command names may always be truncated if that abbreviation is
+unambiguous. Other possible command abbreviations are listed in the
+documentation for individual commands. In some cases, even ambiguous
+abbreviations are allowed; for example, `s' is specially defined as
+equivalent to `step' even though there are other commands whose names
+start with `s'. You can test abbreviations by using them as arguments
+to the `help' command.
+
+ A blank line as input to GDB (typing just <RET>) means to repeat the
+previous command. Certain commands (for example, `run') will not
+repeat this way; these are commands whose unintentional repetition
+might cause trouble and which you are unlikely to want to repeat.
+User-defined commands can disable this feature; see *Note dont-repeat:
+Define.
+
+ The `list' and `x' commands, when you repeat them with <RET>,
+construct new arguments rather than repeating exactly as typed. This
+permits easy scanning of source or memory.
+
+ GDB can also use <RET> in another way: to partition lengthy output,
+in a way similar to the common utility `more' (*note Screen Size:
+Screen Size.). Since it is easy to press one <RET> too many in this
+situation, GDB disables command repetition after any command that
+generates this sort of display.
+
+ Any text from a `#' to the end of the line is a comment; it does
+nothing. This is useful mainly in command files (*note Command Files:
+Command Files.).
+
+ The `Ctrl-o' binding is useful for repeating a complex sequence of
+commands. This command accepts the current line, like <RET>, and then
+fetches the next line relative to the current line from the history for
+editing.
+
+
+File: gdb.info, Node: Completion, Next: Help, Prev: Command Syntax, Up: Commands
+
+3.2 Command Completion
+======================
+
+GDB can fill in the rest of a word in a command for you, if there is
+only one possibility; it can also show you what the valid possibilities
+are for the next word in a command, at any time. This works for GDB
+commands, GDB subcommands, and the names of symbols in your program.
+
+ Press the <TAB> key whenever you want GDB to fill out the rest of a
+word. If there is only one possibility, GDB fills in the word, and
+waits for you to finish the command (or press <RET> to enter it). For
+example, if you type
+
+ (gdb) info bre <TAB>
+
+GDB fills in the rest of the word `breakpoints', since that is the only
+`info' subcommand beginning with `bre':
+
+ (gdb) info breakpoints
+
+You can either press <RET> at this point, to run the `info breakpoints'
+command, or backspace and enter something else, if `breakpoints' does
+not look like the command you expected. (If you were sure you wanted
+`info breakpoints' in the first place, you might as well just type
+<RET> immediately after `info bre', to exploit command abbreviations
+rather than command completion).
+
+ If there is more than one possibility for the next word when you
+press <TAB>, GDB sounds a bell. You can either supply more characters
+and try again, or just press <TAB> a second time; GDB displays all the
+possible completions for that word. For example, you might want to set
+a breakpoint on a subroutine whose name begins with `make_', but when
+you type `b make_<TAB>' GDB just sounds the bell. Typing <TAB> again
+displays all the function names in your program that begin with those
+characters, for example:
+
+ (gdb) b make_ <TAB>
+GDB sounds bell; press <TAB> again, to see:
+ make_a_section_from_file make_environ
+ make_abs_section make_function_type
+ make_blockvector make_pointer_type
+ make_cleanup make_reference_type
+ make_command make_symbol_completion_list
+ (gdb) b make_
+
+After displaying the available possibilities, GDB copies your partial
+input (`b make_' in the example) so you can finish the command.
+
+ If you just want to see the list of alternatives in the first place,
+you can press `M-?' rather than pressing <TAB> twice. `M-?' means
+`<META> ?'. You can type this either by holding down a key designated
+as the <META> shift on your keyboard (if there is one) while typing
+`?', or as <ESC> followed by `?'.
+
+ Sometimes the string you need, while logically a "word", may contain
+parentheses or other characters that GDB normally excludes from its
+notion of a word. To permit word completion to work in this situation,
+you may enclose words in `'' (single quote marks) in GDB commands.
+
+ The most likely situation where you might need this is in typing the
+name of a C++ function. This is because C++ allows function
+overloading (multiple definitions of the same function, distinguished
+by argument type). For example, when you want to set a breakpoint you
+may need to distinguish whether you mean the version of `name' that
+takes an `int' parameter, `name(int)', or the version that takes a
+`float' parameter, `name(float)'. To use the word-completion
+facilities in this situation, type a single quote `'' at the beginning
+of the function name. This alerts GDB that it may need to consider
+more information than usual when you press <TAB> or `M-?' to request
+word completion:
+
+ (gdb) b 'bubble( M-?
+ bubble(double,double) bubble(int,int)
+ (gdb) b 'bubble(
+
+ In some cases, GDB can tell that completing a name requires using
+quotes. When this happens, GDB inserts the quote for you (while
+completing as much as it can) if you do not type the quote in the first
+place:
+
+ (gdb) b bub <TAB>
+GDB alters your input line to the following, and rings a bell:
+ (gdb) b 'bubble(
+
+In general, GDB can tell that a quote is needed (and inserts it) if you
+have not yet started typing the argument list when you ask for
+completion on an overloaded symbol.
+
+ For more information about overloaded functions, see *Note C++
+Expressions: C Plus Plus Expressions. You can use the command `set
+overload-resolution off' to disable overload resolution; see *Note GDB
+Features for C++: Debugging C Plus Plus.
+
+ When completing in an expression which looks up a field in a
+structure, GDB also tries(1) to limit completions to the field names
+available in the type of the left-hand-side:
+
+ (gdb) p gdb_stdout.M-?
+ magic to_fputs to_rewind
+ to_data to_isatty to_write
+ to_delete to_put to_write_async_safe
+ to_flush to_read
+
+This is because the `gdb_stdout' is a variable of the type `struct
+ui_file' that is defined in GDB sources as follows:
+
+ struct ui_file
+ {
+ int *magic;
+ ui_file_flush_ftype *to_flush;
+ ui_file_write_ftype *to_write;
+ ui_file_write_async_safe_ftype *to_write_async_safe;
+ ui_file_fputs_ftype *to_fputs;
+ ui_file_read_ftype *to_read;
+ ui_file_delete_ftype *to_delete;
+ ui_file_isatty_ftype *to_isatty;
+ ui_file_rewind_ftype *to_rewind;
+ ui_file_put_ftype *to_put;
+ void *to_data;
+ }
+
+ ---------- Footnotes ----------
+
+ (1) The completer can be confused by certain kinds of invalid
+expressions. Also, it only examines the static type of the expression,
+not the dynamic type.
+
+
+File: gdb.info, Node: Help, Prev: Completion, Up: Commands
+
+3.3 Getting Help
+================
+
+You can always ask GDB itself for information on its commands, using
+the command `help'.
+
+`help'
+`h'
+ You can use `help' (abbreviated `h') with no arguments to display
+ a short list of named classes of commands:
+
+ (gdb) help
+ List of classes of commands:
+
+ aliases -- Aliases of other commands
+ breakpoints -- Making program stop at certain points
+ data -- Examining data
+ files -- Specifying and examining files
+ internals -- Maintenance commands
+ obscure -- Obscure features
+ running -- Running the program
+ stack -- Examining the stack
+ status -- Status inquiries
+ support -- Support facilities
+ tracepoints -- Tracing of program execution without
+ stopping the program
+ user-defined -- User-defined commands
+
+ Type "help" followed by a class name for a list of
+ commands in that class.
+ Type "help" followed by command name for full
+ documentation.
+ Command name abbreviations are allowed if unambiguous.
+ (gdb)
+
+`help CLASS'
+ Using one of the general help classes as an argument, you can get a
+ list of the individual commands in that class. For example, here
+ is the help display for the class `status':
+
+ (gdb) help status
+ Status inquiries.
+
+ List of commands:
+
+ info -- Generic command for showing things
+ about the program being debugged
+ show -- Generic command for showing things
+ about the debugger
+
+ Type "help" followed by command name for full
+ documentation.
+ Command name abbreviations are allowed if unambiguous.
+ (gdb)
+
+`help COMMAND'
+ With a command name as `help' argument, GDB displays a short
+ paragraph on how to use that command.
+
+`apropos ARGS'
+ The `apropos' command searches through all of the GDB commands,
+ and their documentation, for the regular expression specified in
+ ARGS. It prints out all matches found. For example:
+
+ apropos reload
+
+ results in:
+
+ set symbol-reloading -- Set dynamic symbol table reloading
+ multiple times in one run
+ show symbol-reloading -- Show dynamic symbol table reloading
+ multiple times in one run
+
+`complete ARGS'
+ The `complete ARGS' command lists all the possible completions for
+ the beginning of a command. Use ARGS to specify the beginning of
+ the command you want completed. For example:
+
+ complete i
+
+ results in:
+
+ if
+ ignore
+ info
+ inspect
+
+ This is intended for use by GNU Emacs.
+
+ In addition to `help', you can use the GDB commands `info' and
+`show' to inquire about the state of your program, or the state of GDB
+itself. Each command supports many topics of inquiry; this manual
+introduces each of them in the appropriate context. The listings under
+`info' and under `show' in the Index point to all the sub-commands.
+*Note Index::.
+
+`info'
+ This command (abbreviated `i') is for describing the state of your
+ program. For example, you can show the arguments passed to a
+ function with `info args', list the registers currently in use
+ with `info registers', or list the breakpoints you have set with
+ `info breakpoints'. You can get a complete list of the `info'
+ sub-commands with `help info'.
+
+`set'
+ You can assign the result of an expression to an environment
+ variable with `set'. For example, you can set the GDB prompt to a
+ $-sign with `set prompt $'.
+
+`show'
+ In contrast to `info', `show' is for describing the state of GDB
+ itself. You can change most of the things you can `show', by
+ using the related command `set'; for example, you can control what
+ number system is used for displays with `set radix', or simply
+ inquire which is currently in use with `show radix'.
+
+ To display all the settable parameters and their current values,
+ you can use `show' with no arguments; you may also use `info set'.
+ Both commands produce the same display.
+
+ Here are three miscellaneous `show' subcommands, all of which are
+exceptional in lacking corresponding `set' commands:
+
+`show version'
+ Show what version of GDB is running. You should include this
+ information in GDB bug-reports. If multiple versions of GDB are
+ in use at your site, you may need to determine which version of
+ GDB you are running; as GDB evolves, new commands are introduced,
+ and old ones may wither away. Also, many system vendors ship
+ variant versions of GDB, and there are variant versions of GDB in
+ GNU/Linux distributions as well. The version number is the same
+ as the one announced when you start GDB.
+
+`show copying'
+`info copying'
+ Display information about permission for copying GDB.
+
+`show warranty'
+`info warranty'
+ Display the GNU "NO WARRANTY" statement, or a warranty, if your
+ version of GDB comes with one.
+
+
+
+File: gdb.info, Node: Running, Next: Stopping, Prev: Commands, Up: Top
+
+4 Running Programs Under GDB
+****************************
+
+When you run a program under GDB, you must first generate debugging
+information when you compile it.
+
+ You may start GDB with its arguments, if any, in an environment of
+your choice. If you are doing native debugging, you may redirect your
+program's input and output, debug an already running process, or kill a
+child process.
+
+* Menu:
+
+* Compilation:: Compiling for debugging
+* Starting:: Starting your program
+* Arguments:: Your program's arguments
+* Environment:: Your program's environment
+
+* Working Directory:: Your program's working directory
+* Input/Output:: Your program's input and output
+* Attach:: Debugging an already-running process
+* Kill Process:: Killing the child process
+
+* Inferiors and Programs:: Debugging multiple inferiors and programs
+* Threads:: Debugging programs with multiple threads
+* Forks:: Debugging forks
+* Checkpoint/Restart:: Setting a _bookmark_ to return to later
+
+
+File: gdb.info, Node: Compilation, Next: Starting, Up: Running
+
+4.1 Compiling for Debugging
+===========================
+
+In order to debug a program effectively, you need to generate debugging
+information when you compile it. This debugging information is stored
+in the object file; it describes the data type of each variable or
+function and the correspondence between source line numbers and
+addresses in the executable code.
+
+ To request debugging information, specify the `-g' option when you
+run the compiler.
+
+ Programs that are to be shipped to your customers are compiled with
+optimizations, using the `-O' compiler option. However, some compilers
+are unable to handle the `-g' and `-O' options together. Using those
+compilers, you cannot generate optimized executables containing
+debugging information.
+
+ GCC, the GNU C/C++ compiler, supports `-g' with or without `-O',
+making it possible to debug optimized code. We recommend that you
+_always_ use `-g' whenever you compile a program. You may think your
+program is correct, but there is no sense in pushing your luck. For
+more information, see *Note Optimized Code::.
+
+ Older versions of the GNU C compiler permitted a variant option
+`-gg' for debugging information. GDB no longer supports this format;
+if your GNU C compiler has this option, do not use it.
+
+ GDB knows about preprocessor macros and can show you their expansion
+(*note Macros::). Most compilers do not include information about
+preprocessor macros in the debugging information if you specify the
+`-g' flag alone. Version 3.1 and later of GCC, the GNU C compiler,
+provides macro information if you are using the DWARF debugging format,
+and specify the option `-g3'.
+
+ *Note Options for Debugging Your Program or GCC: (gcc.info)Debugging
+Options, for more information on GCC options affecting debug
+information.
+
+ You will have the best debugging experience if you use the latest
+version of the DWARF debugging format that your compiler supports.
+DWARF is currently the most expressive and best supported debugging
+format in GDB.
+
+
+File: gdb.info, Node: Starting, Next: Arguments, Prev: Compilation, Up: Running
+
+4.2 Starting your Program
+=========================
+
+`run'
+`r'
+ Use the `run' command to start your program under GDB. You must
+ first specify the program name (except on VxWorks) with an
+ argument to GDB (*note Getting In and Out of GDB: Invocation.), or
+ by using the `file' or `exec-file' command (*note Commands to
+ Specify Files: Files.).
+
+
+ If you are running your program in an execution environment that
+supports processes, `run' creates an inferior process and makes that
+process run your program. In some environments without processes,
+`run' jumps to the start of your program. Other targets, like
+`remote', are always running. If you get an error message like this
+one:
+
+ The "remote" target does not support "run".
+ Try "help target" or "continue".
+
+then use `continue' to run your program. You may need `load' first
+(*note load::).
+
+ The execution of a program is affected by certain information it
+receives from its superior. GDB provides ways to specify this
+information, which you must do _before_ starting your program. (You
+can change it after starting your program, but such changes only affect
+your program the next time you start it.) This information may be
+divided into four categories:
+
+The _arguments._
+ Specify the arguments to give your program as the arguments of the
+ `run' command. If a shell is available on your target, the shell
+ is used to pass the arguments, so that you may use normal
+ conventions (such as wildcard expansion or variable substitution)
+ in describing the arguments. In Unix systems, you can control
+ which shell is used with the `SHELL' environment variable. *Note
+ Your Program's Arguments: Arguments.
+
+The _environment._
+ Your program normally inherits its environment from GDB, but you
+ can use the GDB commands `set environment' and `unset environment'
+ to change parts of the environment that affect your program.
+ *Note Your Program's Environment: Environment.
+
+The _working directory._
+ Your program inherits its working directory from GDB. You can set
+ the GDB working directory with the `cd' command in GDB. *Note
+ Your Program's Working Directory: Working Directory.
+
+The _standard input and output._
+ Your program normally uses the same device for standard input and
+ standard output as GDB is using. You can redirect input and output
+ in the `run' command line, or you can use the `tty' command to set
+ a different device for your program. *Note Your Program's Input
+ and Output: Input/Output.
+
+ _Warning:_ While input and output redirection work, you cannot use
+ pipes to pass the output of the program you are debugging to
+ another program; if you attempt this, GDB is likely to wind up
+ debugging the wrong program.
+
+ When you issue the `run' command, your program begins to execute
+immediately. *Note Stopping and Continuing: Stopping, for discussion
+of how to arrange for your program to stop. Once your program has
+stopped, you may call functions in your program, using the `print' or
+`call' commands. *Note Examining Data: Data.
+
+ If the modification time of your symbol file has changed since the
+last time GDB read its symbols, GDB discards its symbol table, and
+reads it again. When it does this, GDB tries to retain your current
+breakpoints.
+
+`start'
+ The name of the main procedure can vary from language to language.
+ With C or C++, the main procedure name is always `main', but other
+ languages such as Ada do not require a specific name for their
+ main procedure. The debugger provides a convenient way to start
+ the execution of the program and to stop at the beginning of the
+ main procedure, depending on the language used.
+
+ The `start' command does the equivalent of setting a temporary
+ breakpoint at the beginning of the main procedure and then invoking
+ the `run' command.
+
+ Some programs contain an "elaboration" phase where some startup
+ code is executed before the main procedure is called. This
+ depends on the languages used to write your program. In C++, for
+ instance, constructors for static and global objects are executed
+ before `main' is called. It is therefore possible that the
+ debugger stops before reaching the main procedure. However, the
+ temporary breakpoint will remain to halt execution.
+
+ Specify the arguments to give to your program as arguments to the
+ `start' command. These arguments will be given verbatim to the
+ underlying `run' command. Note that the same arguments will be
+ reused if no argument is provided during subsequent calls to
+ `start' or `run'.
+
+ It is sometimes necessary to debug the program during elaboration.
+ In these cases, using the `start' command would stop the
+ execution of your program too late, as the program would have
+ already completed the elaboration phase. Under these
+ circumstances, insert breakpoints in your elaboration code before
+ running your program.
+
+`set exec-wrapper WRAPPER'
+`show exec-wrapper'
+`unset exec-wrapper'
+ When `exec-wrapper' is set, the specified wrapper is used to
+ launch programs for debugging. GDB starts your program with a
+ shell command of the form `exec WRAPPER PROGRAM'. Quoting is
+ added to PROGRAM and its arguments, but not to WRAPPER, so you
+ should add quotes if appropriate for your shell. The wrapper runs
+ until it executes your program, and then GDB takes control.
+
+ You can use any program that eventually calls `execve' with its
+ arguments as a wrapper. Several standard Unix utilities do this,
+ e.g. `env' and `nohup'. Any Unix shell script ending with `exec
+ "$@"' will also work.
+
+ For example, you can use `env' to pass an environment variable to
+ the debugged program, without setting the variable in your shell's
+ environment:
+
+ (gdb) set exec-wrapper env 'LD_PRELOAD=libtest.so'
+ (gdb) run
+
+ This command is available when debugging locally on most targets,
+ excluding DJGPP, Cygwin, MS Windows, and QNX Neutrino.
+
+`set disable-randomization'
+`set disable-randomization on'
+ This option (enabled by default in GDB) will turn off the native
+ randomization of the virtual address space of the started program.
+ This option is useful for multiple debugging sessions to make the
+ execution better reproducible and memory addresses reusable across
+ debugging sessions.
+
+ This feature is implemented only on certain targets, including
+ GNU/Linux. On GNU/Linux you can get the same behavior using
+
+ (gdb) set exec-wrapper setarch `uname -m` -R
+
+`set disable-randomization off'
+ Leave the behavior of the started executable unchanged. Some bugs
+ rear their ugly heads only when the program is loaded at certain
+ addresses. If your bug disappears when you run the program under
+ GDB, that might be because GDB by default disables the address
+ randomization on platforms, such as GNU/Linux, which do that for
+ stand-alone programs. Use `set disable-randomization off' to try
+ to reproduce such elusive bugs.
+
+ On targets where it is available, virtual address space
+ randomization protects the programs against certain kinds of
+ security attacks. In these cases the attacker needs to know the
+ exact location of a concrete executable code. Randomizing its
+ location makes it impossible to inject jumps misusing a code at
+ its expected addresses.
+
+ Prelinking shared libraries provides a startup performance
+ advantage but it makes addresses in these libraries predictable
+ for privileged processes by having just unprivileged access at the
+ target system. Reading the shared library binary gives enough
+ information for assembling the malicious code misusing it. Still
+ even a prelinked shared library can get loaded at a new random
+ address just requiring the regular relocation process during the
+ startup. Shared libraries not already prelinked are always loaded
+ at a randomly chosen address.
+
+ Position independent executables (PIE) contain position
+ independent code similar to the shared libraries and therefore
+ such executables get loaded at a randomly chosen address upon
+ startup. PIE executables always load even already prelinked
+ shared libraries at a random address. You can build such
+ executable using `gcc -fPIE -pie'.
+
+ Heap (malloc storage), stack and custom mmap areas are always
+ placed randomly (as long as the randomization is enabled).
+
+`show disable-randomization'
+ Show the current setting of the explicit disable of the native
+ randomization of the virtual address space of the started program.
+
+
+
+File: gdb.info, Node: Arguments, Next: Environment, Prev: Starting, Up: Running
+
+4.3 Your Program's Arguments
+============================
+
+The arguments to your program can be specified by the arguments of the
+`run' command. They are passed to a shell, which expands wildcard
+characters and performs redirection of I/O, and thence to your program.
+Your `SHELL' environment variable (if it exists) specifies what shell
+GDB uses. If you do not define `SHELL', GDB uses the default shell
+(`/bin/sh' on Unix).
+
+ On non-Unix systems, the program is usually invoked directly by GDB,
+which emulates I/O redirection via the appropriate system calls, and
+the wildcard characters are expanded by the startup code of the
+program, not by the shell.
+
+ `run' with no arguments uses the same arguments used by the previous
+`run', or those set by the `set args' command.
+
+`set args'
+ Specify the arguments to be used the next time your program is
+ run. If `set args' has no arguments, `run' executes your program
+ with no arguments. Once you have run your program with arguments,
+ using `set args' before the next `run' is the only way to run it
+ again without arguments.
+
+`show args'
+ Show the arguments to give your program when it is started.
+
+
+File: gdb.info, Node: Environment, Next: Working Directory, Prev: Arguments, Up: Running
+
+4.4 Your Program's Environment
+==============================
+
+The "environment" consists of a set of environment variables and their
+values. Environment variables conventionally record such things as
+your user name, your home directory, your terminal type, and your search
+path for programs to run. Usually you set up environment variables with
+the shell and they are inherited by all the other programs you run.
+When debugging, it can be useful to try running your program with a
+modified environment without having to start GDB over again.
+
+`path DIRECTORY'
+ Add DIRECTORY to the front of the `PATH' environment variable (the
+ search path for executables) that will be passed to your program.
+ The value of `PATH' used by GDB does not change. You may specify
+ several directory names, separated by whitespace or by a
+ system-dependent separator character (`:' on Unix, `;' on MS-DOS
+ and MS-Windows). If DIRECTORY is already in the path, it is moved
+ to the front, so it is searched sooner.
+
+ You can use the string `$cwd' to refer to whatever is the current
+ working directory at the time GDB searches the path. If you use
+ `.' instead, it refers to the directory where you executed the
+ `path' command. GDB replaces `.' in the DIRECTORY argument (with
+ the current path) before adding DIRECTORY to the search path.
+
+`show paths'
+ Display the list of search paths for executables (the `PATH'
+ environment variable).
+
+`show environment [VARNAME]'
+ Print the value of environment variable VARNAME to be given to
+ your program when it starts. If you do not supply VARNAME, print
+ the names and values of all environment variables to be given to
+ your program. You can abbreviate `environment' as `env'.
+
+`set environment VARNAME [=VALUE]'
+ Set environment variable VARNAME to VALUE. The value changes for
+ your program only, not for GDB itself. VALUE may be any string;
+ the values of environment variables are just strings, and any
+ interpretation is supplied by your program itself. The VALUE
+ parameter is optional; if it is eliminated, the variable is set to
+ a null value.
+
+ For example, this command:
+
+ set env USER = foo
+
+ tells the debugged program, when subsequently run, that its user
+ is named `foo'. (The spaces around `=' are used for clarity here;
+ they are not actually required.)
+
+`unset environment VARNAME'
+ Remove variable VARNAME from the environment to be passed to your
+ program. This is different from `set env VARNAME ='; `unset
+ environment' removes the variable from the environment, rather
+ than assigning it an empty value.
+
+ _Warning:_ On Unix systems, GDB runs your program using the shell
+indicated by your `SHELL' environment variable if it exists (or
+`/bin/sh' if not). If your `SHELL' variable names a shell that runs an
+initialization file--such as `.cshrc' for C-shell, or `.bashrc' for
+BASH--any variables you set in that file affect your program. You may
+wish to move setting of environment variables to files that are only
+run when you sign on, such as `.login' or `.profile'.
+
+
+File: gdb.info, Node: Working Directory, Next: Input/Output, Prev: Environment, Up: Running
+
+4.5 Your Program's Working Directory
+====================================
+
+Each time you start your program with `run', it inherits its working
+directory from the current working directory of GDB. The GDB working
+directory is initially whatever it inherited from its parent process
+(typically the shell), but you can specify a new working directory in
+GDB with the `cd' command.
+
+ The GDB working directory also serves as a default for the commands
+that specify files for GDB to operate on. *Note Commands to Specify
+Files: Files.
+
+`cd DIRECTORY'
+ Set the GDB working directory to DIRECTORY.
+
+`pwd'
+ Print the GDB working directory.
+
+ It is generally impossible to find the current working directory of
+the process being debugged (since a program can change its directory
+during its run). If you work on a system where GDB is configured with
+the `/proc' support, you can use the `info proc' command (*note SVR4
+Process Information::) to find out the current working directory of the
+debuggee.
+
+
+File: gdb.info, Node: Input/Output, Next: Attach, Prev: Working Directory, Up: Running
+
+4.6 Your Program's Input and Output
+===================================
+
+By default, the program you run under GDB does input and output to the
+same terminal that GDB uses. GDB switches the terminal to its own
+terminal modes to interact with you, but it records the terminal modes
+your program was using and switches back to them when you continue
+running your program.
+
+`info terminal'
+ Displays information recorded by GDB about the terminal modes your
+ program is using.
+
+ You can redirect your program's input and/or output using shell
+redirection with the `run' command. For example,
+
+ run > outfile
+
+starts your program, diverting its output to the file `outfile'.
+
+ Another way to specify where your program should do input and output
+is with the `tty' command. This command accepts a file name as
+argument, and causes this file to be the default for future `run'
+commands. It also resets the controlling terminal for the child
+process, for future `run' commands. For example,
+
+ tty /dev/ttyb
+
+directs that processes started with subsequent `run' commands default
+to do input and output on the terminal `/dev/ttyb' and have that as
+their controlling terminal.
+
+ An explicit redirection in `run' overrides the `tty' command's
+effect on the input/output device, but not its effect on the controlling
+terminal.
+
+ When you use the `tty' command or redirect input in the `run'
+command, only the input _for your program_ is affected. The input for
+GDB still comes from your terminal. `tty' is an alias for `set
+inferior-tty'.
+
+ You can use the `show inferior-tty' command to tell GDB to display
+the name of the terminal that will be used for future runs of your
+program.
+
+`set inferior-tty /dev/ttyb'
+ Set the tty for the program being debugged to /dev/ttyb.
+
+`show inferior-tty'
+ Show the current tty for the program being debugged.
+
+
+File: gdb.info, Node: Attach, Next: Kill Process, Prev: Input/Output, Up: Running
+
+4.7 Debugging an Already-running Process
+========================================
+
+`attach PROCESS-ID'
+ This command attaches to a running process--one that was started
+ outside GDB. (`info files' shows your active targets.) The
+ command takes as argument a process ID. The usual way to find out
+ the PROCESS-ID of a Unix process is with the `ps' utility, or with
+ the `jobs -l' shell command.
+
+ `attach' does not repeat if you press <RET> a second time after
+ executing the command.
+
+ To use `attach', your program must be running in an environment
+which supports processes; for example, `attach' does not work for
+programs on bare-board targets that lack an operating system. You must
+also have permission to send the process a signal.
+
+ When you use `attach', the debugger finds the program running in the
+process first by looking in the current working directory, then (if the
+program is not found) by using the source file search path (*note
+Specifying Source Directories: Source Path.). You can also use the
+`file' command to load the program. *Note Commands to Specify Files:
+Files.
+
+ The first thing GDB does after arranging to debug the specified
+process is to stop it. You can examine and modify an attached process
+with all the GDB commands that are ordinarily available when you start
+processes with `run'. You can insert breakpoints; you can step and
+continue; you can modify storage. If you would rather the process
+continue running, you may use the `continue' command after attaching
+GDB to the process.
+
+`detach'
+ When you have finished debugging the attached process, you can use
+ the `detach' command to release it from GDB control. Detaching
+ the process continues its execution. After the `detach' command,
+ that process and GDB become completely independent once more, and
+ you are ready to `attach' another process or start one with `run'.
+ `detach' does not repeat if you press <RET> again after executing
+ the command.
+
+ If you exit GDB while you have an attached process, you detach that
+process. If you use the `run' command, you kill that process. By
+default, GDB asks for confirmation if you try to do either of these
+things; you can control whether or not you need to confirm by using the
+`set confirm' command (*note Optional Warnings and Messages:
+Messages/Warnings.).
+
+
+File: gdb.info, Node: Kill Process, Next: Inferiors and Programs, Prev: Attach, Up: Running
+
+4.8 Killing the Child Process
+=============================
+
+`kill'
+ Kill the child process in which your program is running under GDB.
+
+ This command is useful if you wish to debug a core dump instead of a
+running process. GDB ignores any core dump file while your program is
+running.
+
+ On some operating systems, a program cannot be executed outside GDB
+while you have breakpoints set on it inside GDB. You can use the
+`kill' command in this situation to permit running your program outside
+the debugger.
+
+ The `kill' command is also useful if you wish to recompile and
+relink your program, since on many systems it is impossible to modify an
+executable file while it is running in a process. In this case, when
+you next type `run', GDB notices that the file has changed, and reads
+the symbol table again (while trying to preserve your current
+breakpoint settings).
+
+
+File: gdb.info, Node: Inferiors and Programs, Next: Threads, Prev: Kill Process, Up: Running
+
+4.9 Debugging Multiple Inferiors and Programs
+=============================================
+
+GDB lets you run and debug multiple programs in a single session. In
+addition, GDB on some systems may let you run several programs
+simultaneously (otherwise you have to exit from one before starting
+another). In the most general case, you can have multiple threads of
+execution in each of multiple processes, launched from multiple
+executables.
+
+ GDB represents the state of each program execution with an object
+called an "inferior". An inferior typically corresponds to a process,
+but is more general and applies also to targets that do not have
+processes. Inferiors may be created before a process runs, and may be
+retained after a process exits. Inferiors have unique identifiers that
+are different from process ids. Usually each inferior will also have
+its own distinct address space, although some embedded targets may have
+several inferiors running in different parts of a single address space.
+Each inferior may in turn have multiple threads running in it.
+
+ To find out what inferiors exist at any moment, use `info inferiors':
+
+`info inferiors'
+ Print a list of all inferiors currently being managed by GDB.
+
+ GDB displays for each inferior (in this order):
+
+ 1. the inferior number assigned by GDB
+
+ 2. the target system's inferior identifier
+
+ 3. the name of the executable the inferior is running.
+
+
+ An asterisk `*' preceding the GDB inferior number indicates the
+ current inferior.
+
+ For example,
+
+ (gdb) info inferiors
+ Num Description Executable
+ 2 process 2307 hello
+ * 1 process 3401 goodbye
+
+ To switch focus between inferiors, use the `inferior' command:
+
+`inferior INFNO'
+ Make inferior number INFNO the current inferior. The argument
+ INFNO is the inferior number assigned by GDB, as shown in the
+ first field of the `info inferiors' display.
+
+ You can get multiple executables into a debugging session via the
+`add-inferior' and `clone-inferior' commands. On some systems GDB can
+add inferiors to the debug session automatically by following calls to
+`fork' and `exec'. To remove inferiors from the debugging session use
+the `remove-inferiors' command.
+
+`add-inferior [ -copies N ] [ -exec EXECUTABLE ]'
+ Adds N inferiors to be run using EXECUTABLE as the executable. N
+ defaults to 1. If no executable is specified, the inferiors
+ begins empty, with no program. You can still assign or change the
+ program assigned to the inferior at any time by using the `file'
+ command with the executable name as its argument.
+
+`clone-inferior [ -copies N ] [ INFNO ]'
+ Adds N inferiors ready to execute the same program as inferior
+ INFNO. N defaults to 1. INFNO defaults to the number of the
+ current inferior. This is a convenient command when you want to
+ run another instance of the inferior you are debugging.
+
+ (gdb) info inferiors
+ Num Description Executable
+ * 1 process 29964 helloworld
+ (gdb) clone-inferior
+ Added inferior 2.
+ 1 inferiors added.
+ (gdb) info inferiors
+ Num Description Executable
+ 2 <null> helloworld
+ * 1 process 29964 helloworld
+
+ You can now simply switch focus to inferior 2 and run it.
+
+`remove-inferiors INFNO...'
+ Removes the inferior or inferiors INFNO.... It is not possible to
+ remove an inferior that is running with this command. For those,
+ use the `kill' or `detach' command first.
+
+
+ To quit debugging one of the running inferiors that is not the
+current inferior, you can either detach from it by using the
+`detach inferior' command (allowing it to run independently), or kill it
+using the `kill inferiors' command:
+
+`detach inferior INFNO...'
+ Detach from the inferior or inferiors identified by GDB inferior
+ number(s) INFNO.... Note that the inferior's entry still stays on
+ the list of inferiors shown by `info inferiors', but its
+ Description will show `<null>'.
+
+`kill inferiors INFNO...'
+ Kill the inferior or inferiors identified by GDB inferior
+ number(s) INFNO.... Note that the inferior's entry still stays on
+ the list of inferiors shown by `info inferiors', but its
+ Description will show `<null>'.
+
+ After the successful completion of a command such as `detach',
+`detach inferiors', `kill' or `kill inferiors', or after a normal
+process exit, the inferior is still valid and listed with `info
+inferiors', ready to be restarted.
+
+ To be notified when inferiors are started or exit under GDB's
+control use `set print inferior-events':
+
+`set print inferior-events'
+`set print inferior-events on'
+`set print inferior-events off'
+ The `set print inferior-events' command allows you to enable or
+ disable printing of messages when GDB notices that new inferiors
+ have started or that inferiors have exited or have been detached.
+ By default, these messages will not be printed.
+
+`show print inferior-events'
+ Show whether messages will be printed when GDB detects that
+ inferiors have started, exited or have been detached.
+
+ Many commands will work the same with multiple programs as with a
+single program: e.g., `print myglobal' will simply display the value of
+`myglobal' in the current inferior.
+
+ Occasionaly, when debugging GDB itself, it may be useful to get more
+info about the relationship of inferiors, programs, address spaces in a
+debug session. You can do that with the `maint info program-spaces'
+command.
+
+`maint info program-spaces'
+ Print a list of all program spaces currently being managed by GDB.
+
+ GDB displays for each program space (in this order):
+
+ 1. the program space number assigned by GDB
+
+ 2. the name of the executable loaded into the program space,
+ with e.g., the `file' command.
+
+
+ An asterisk `*' preceding the GDB program space number indicates
+ the current program space.
+
+ In addition, below each program space line, GDB prints extra
+ information that isn't suitable to display in tabular form. For
+ example, the list of inferiors bound to the program space.
+
+ (gdb) maint info program-spaces
+ Id Executable
+ 2 goodbye
+ Bound inferiors: ID 1 (process 21561)
+ * 1 hello
+
+ Here we can see that no inferior is running the program `hello',
+ while `process 21561' is running the program `goodbye'. On some
+ targets, it is possible that multiple inferiors are bound to the
+ same program space. The most common example is that of debugging
+ both the parent and child processes of a `vfork' call. For
+ example,
+
+ (gdb) maint info program-spaces
+ Id Executable
+ * 1 vfork-test
+ Bound inferiors: ID 2 (process 18050), ID 1 (process 18045)
+
+ Here, both inferior 2 and inferior 1 are running in the same
+ program space as a result of inferior 1 having executed a `vfork'
+ call.
+
+
+File: gdb.info, Node: Threads, Next: Forks, Prev: Inferiors and Programs, Up: Running
+
+4.10 Debugging Programs with Multiple Threads
+=============================================
+
+In some operating systems, such as HP-UX and Solaris, a single program
+may have more than one "thread" of execution. The precise semantics of
+threads differ from one operating system to another, but in general the
+threads of a single program are akin to multiple processes--except that
+they share one address space (that is, they can all examine and modify
+the same variables). On the other hand, each thread has its own
+registers and execution stack, and perhaps private memory.
+
+ GDB provides these facilities for debugging multi-thread programs:
+
+ * automatic notification of new threads
+
+ * `thread THREADNO', a command to switch among threads
+
+ * `info threads', a command to inquire about existing threads
+
+ * `thread apply [THREADNO] [ALL] ARGS', a command to apply a command
+ to a list of threads
+
+ * thread-specific breakpoints
+
+ * `set print thread-events', which controls printing of messages on
+ thread start and exit.
+
+ * `set libthread-db-search-path PATH', which lets the user specify
+ which `libthread_db' to use if the default choice isn't compatible
+ with the program.
+
+ _Warning:_ These facilities are not yet available on every GDB
+ configuration where the operating system supports threads. If
+ your GDB does not support threads, these commands have no effect.
+ For example, a system without thread support shows no output from
+ `info threads', and always rejects the `thread' command, like this:
+
+ (gdb) info threads
+ (gdb) thread 1
+ Thread ID 1 not known. Use the "info threads" command to
+ see the IDs of currently known threads.
+
+ The GDB thread debugging facility allows you to observe all threads
+while your program runs--but whenever GDB takes control, one thread in
+particular is always the focus of debugging. This thread is called the
+"current thread". Debugging commands show program information from the
+perspective of the current thread.
+
+ Whenever GDB detects a new thread in your program, it displays the
+target system's identification for the thread with a message in the
+form `[New SYSTAG]'. SYSTAG is a thread identifier whose form varies
+depending on the particular system. For example, on GNU/Linux, you
+might see
+
+ [New Thread 0x41e02940 (LWP 25582)]
+
+when GDB notices a new thread. In contrast, on an SGI system, the
+SYSTAG is simply something like `process 368', with no further
+qualifier.
+
+ For debugging purposes, GDB associates its own thread number--always
+a single integer--with each thread in your program.
+
+`info threads [ID...]'
+ Display a summary of all threads currently in your program.
+ Optional argument ID... is one or more thread ids separated by
+ spaces, and means to print information only about the specified
+ thread or threads. GDB displays for each thread (in this order):
+
+ 1. the thread number assigned by GDB
+
+ 2. the target system's thread identifier (SYSTAG)
+
+ 3. the thread's name, if one is known. A thread can either be
+ named by the user (see `thread name', below), or, in some
+ cases, by the program itself.
+
+ 4. the current stack frame summary for that thread
+
+ An asterisk `*' to the left of the GDB thread number indicates the
+ current thread.
+
+ For example,
+
+ (gdb) info threads
+ Id Target Id Frame
+ 3 process 35 thread 27 0x34e5 in sigpause ()
+ 2 process 35 thread 23 0x34e5 in sigpause ()
+ * 1 process 35 thread 13 main (argc=1, argv=0x7ffffff8)
+ at threadtest.c:68
+
+ On Solaris, you can display more information about user threads with
+a Solaris-specific command:
+
+`maint info sol-threads'
+ Display info on Solaris user threads.
+
+`thread THREADNO'
+ Make thread number THREADNO the current thread. The command
+ argument THREADNO is the internal GDB thread number, as shown in
+ the first field of the `info threads' display. GDB responds by
+ displaying the system identifier of the thread you selected, and
+ its current stack frame summary:
+
+ (gdb) thread 2
+ [Switching to thread 2 (Thread 0xb7fdab70 (LWP 12747))]
+ #0 some_function (ignore=0x0) at example.c:8
+ 8 printf ("hello\n");
+
+ As with the `[New ...]' message, the form of the text after
+ `Switching to' depends on your system's conventions for identifying
+ threads.
+
+ The debugger convenience variable `$_thread' contains the number
+ of the current thread. You may find this useful in writing
+ breakpoint conditional expressions, command scripts, and so forth.
+ See *Note Convenience Variables: Convenience Vars, for general
+ information on convenience variables.
+
+`thread apply [THREADNO | all] COMMAND'
+ The `thread apply' command allows you to apply the named COMMAND
+ to one or more threads. Specify the numbers of the threads that
+ you want affected with the command argument THREADNO. It can be a
+ single thread number, one of the numbers shown in the first field
+ of the `info threads' display; or it could be a range of thread
+ numbers, as in `2-4'. To apply a command to all threads, type
+ `thread apply all COMMAND'.
+
+`thread name [NAME]'
+ This command assigns a name to the current thread. If no argument
+ is given, any existing user-specified name is removed. The thread
+ name appears in the `info threads' display.
+
+ On some systems, such as GNU/Linux, GDB is able to determine the
+ name of the thread as given by the OS. On these systems, a name
+ specified with `thread name' will override the system-give name,
+ and removing the user-specified name will cause GDB to once again
+ display the system-specified name.
+
+`thread find [REGEXP]'
+ Search for and display thread ids whose name or SYSTAG matches the
+ supplied regular expression.
+
+ As well as being the complement to the `thread name' command, this
+ command also allows you to identify a thread by its target SYSTAG.
+ For instance, on GNU/Linux, the target SYSTAG is the LWP id.
+
+ (GDB) thread find 26688
+ Thread 4 has target id 'Thread 0x41e02940 (LWP 26688)'
+ (GDB) info thread 4
+ Id Target Id Frame
+ 4 Thread 0x41e02940 (LWP 26688) 0x00000031ca6cd372 in select ()
+
+`set print thread-events'
+`set print thread-events on'
+`set print thread-events off'
+ The `set print thread-events' command allows you to enable or
+ disable printing of messages when GDB notices that new threads have
+ started or that threads have exited. By default, these messages
+ will be printed if detection of these events is supported by the
+ target. Note that these messages cannot be disabled on all
+ targets.
+
+`show print thread-events'
+ Show whether messages will be printed when GDB detects that threads
+ have started and exited.
+
+ *Note Stopping and Starting Multi-thread Programs: Thread Stops, for
+more information about how GDB behaves when you stop and start programs
+with multiple threads.
+
+ *Note Setting Watchpoints: Set Watchpoints, for information about
+watchpoints in programs with multiple threads.
+
+`set libthread-db-search-path [PATH]'
+ If this variable is set, PATH is a colon-separated list of
+ directories GDB will use to search for `libthread_db'. If you
+ omit PATH, `libthread-db-search-path' will be reset to its default
+ value (`$sdir:$pdir' on GNU/Linux and Solaris systems).
+ Internally, the default value comes from the
+ `LIBTHREAD_DB_SEARCH_PATH' macro.
+
+ On GNU/Linux and Solaris systems, GDB uses a "helper"
+ `libthread_db' library to obtain information about threads in the
+ inferior process. GDB will use `libthread-db-search-path' to find
+ `libthread_db'.
+
+ A special entry `$sdir' for `libthread-db-search-path' refers to
+ the default system directories that are normally searched for
+ loading shared libraries.
+
+ A special entry `$pdir' for `libthread-db-search-path' refers to
+ the directory from which `libpthread' was loaded in the inferior
+ process.
+
+ For any `libthread_db' library GDB finds in above directories, GDB
+ attempts to initialize it with the current inferior process. If
+ this initialization fails (which could happen because of a version
+ mismatch between `libthread_db' and `libpthread'), GDB will unload
+ `libthread_db', and continue with the next directory. If none of
+ `libthread_db' libraries initialize successfully, GDB will issue a
+ warning and thread debugging will be disabled.
+
+ Setting `libthread-db-search-path' is currently implemented only
+ on some platforms.
+
+`show libthread-db-search-path'
+ Display current libthread_db search path.
+
+`set debug libthread-db'
+`show debug libthread-db'
+ Turns on or off display of `libthread_db'-related events. Use `1'
+ to enable, `0' to disable.
+
+
+File: gdb.info, Node: Forks, Next: Checkpoint/Restart, Prev: Threads, Up: Running
+
+4.11 Debugging Forks
+====================
+
+On most systems, GDB has no special support for debugging programs
+which create additional processes using the `fork' function. When a
+program forks, GDB will continue to debug the parent process and the
+child process will run unimpeded. If you have set a breakpoint in any
+code which the child then executes, the child will get a `SIGTRAP'
+signal which (unless it catches the signal) will cause it to terminate.
+
+ However, if you want to debug the child process there is a workaround
+which isn't too painful. Put a call to `sleep' in the code which the
+child process executes after the fork. It may be useful to sleep only
+if a certain environment variable is set, or a certain file exists, so
+that the delay need not occur when you don't want to run GDB on the
+child. While the child is sleeping, use the `ps' program to get its
+process ID. Then tell GDB (a new invocation of GDB if you are also
+debugging the parent process) to attach to the child process (*note
+Attach::). From that point on you can debug the child process just
+like any other process which you attached to.
+
+ On some systems, GDB provides support for debugging programs that
+create additional processes using the `fork' or `vfork' functions.
+Currently, the only platforms with this feature are HP-UX (11.x and
+later only?) and GNU/Linux (kernel version 2.5.60 and later).
+
+ By default, when a program forks, GDB will continue to debug the
+parent process and the child process will run unimpeded.
+
+ If you want to follow the child process instead of the parent
+process, use the command `set follow-fork-mode'.
+
+`set follow-fork-mode MODE'
+ Set the debugger response to a program call of `fork' or `vfork'.
+ A call to `fork' or `vfork' creates a new process. The MODE
+ argument can be:
+
+ `parent'
+ The original process is debugged after a fork. The child
+ process runs unimpeded. This is the default.
+
+ `child'
+ The new process is debugged after a fork. The parent process
+ runs unimpeded.
+
+
+`show follow-fork-mode'
+ Display the current debugger response to a `fork' or `vfork' call.
+
+ On Linux, if you want to debug both the parent and child processes,
+use the command `set detach-on-fork'.
+
+`set detach-on-fork MODE'
+ Tells gdb whether to detach one of the processes after a fork, or
+ retain debugger control over them both.
+
+ `on'
+ The child process (or parent process, depending on the value
+ of `follow-fork-mode') will be detached and allowed to run
+ independently. This is the default.
+
+ `off'
+ Both processes will be held under the control of GDB. One
+ process (child or parent, depending on the value of
+ `follow-fork-mode') is debugged as usual, while the other is
+ held suspended.
+
+
+`show detach-on-fork'
+ Show whether detach-on-fork mode is on/off.
+
+ If you choose to set `detach-on-fork' mode off, then GDB will retain
+control of all forked processes (including nested forks). You can list
+the forked processes under the control of GDB by using the
+`info inferiors' command, and switch from one fork to another by using
+the `inferior' command (*note Debugging Multiple Inferiors and
+Programs: Inferiors and Programs.).
+
+ To quit debugging one of the forked processes, you can either detach
+from it by using the `detach inferiors' command (allowing it to run
+independently), or kill it using the `kill inferiors' command. *Note
+Debugging Multiple Inferiors and Programs: Inferiors and Programs.
+
+ If you ask to debug a child process and a `vfork' is followed by an
+`exec', GDB executes the new target up to the first breakpoint in the
+new target. If you have a breakpoint set on `main' in your original
+program, the breakpoint will also be set on the child process's `main'.
+
+ On some systems, when a child process is spawned by `vfork', you
+cannot debug the child or parent until an `exec' call completes.
+
+ If you issue a `run' command to GDB after an `exec' call executes,
+the new target restarts. To restart the parent process, use the `file'
+command with the parent executable name as its argument. By default,
+after an `exec' call executes, GDB discards the symbols of the previous
+executable image. You can change this behaviour with the
+`set follow-exec-mode' command.
+
+`set follow-exec-mode MODE'
+ Set debugger response to a program call of `exec'. An `exec' call
+ replaces the program image of a process.
+
+ `follow-exec-mode' can be:
+
+ `new'
+ GDB creates a new inferior and rebinds the process to this
+ new inferior. The program the process was running before the
+ `exec' call can be restarted afterwards by restarting the
+ original inferior.
+
+ For example:
+
+ (gdb) info inferiors
+ (gdb) info inferior
+ Id Description Executable
+ * 1 <null> prog1
+ (gdb) run
+ process 12020 is executing new program: prog2
+ Program exited normally.
+ (gdb) info inferiors
+ Id Description Executable
+ * 2 <null> prog2
+ 1 <null> prog1
+
+ `same'
+ GDB keeps the process bound to the same inferior. The new
+ executable image replaces the previous executable loaded in
+ the inferior. Restarting the inferior after the `exec' call,
+ with e.g., the `run' command, restarts the executable the
+ process was running after the `exec' call. This is the
+ default mode.
+
+ For example:
+
+ (gdb) info inferiors
+ Id Description Executable
+ * 1 <null> prog1
+ (gdb) run
+ process 12020 is executing new program: prog2
+ Program exited normally.
+ (gdb) info inferiors
+ Id Description Executable
+ * 1 <null> prog2
+
+
+ You can use the `catch' command to make GDB stop whenever a `fork',
+`vfork', or `exec' call is made. *Note Setting Catchpoints: Set
+Catchpoints.
+
+
+File: gdb.info, Node: Checkpoint/Restart, Prev: Forks, Up: Running
+
+4.12 Setting a _Bookmark_ to Return to Later
+============================================
+
+On certain operating systems(1), GDB is able to save a "snapshot" of a
+program's state, called a "checkpoint", and come back to it later.
+
+ Returning to a checkpoint effectively undoes everything that has
+happened in the program since the `checkpoint' was saved. This
+includes changes in memory, registers, and even (within some limits)
+system state. Effectively, it is like going back in time to the moment
+when the checkpoint was saved.
+
+ Thus, if you're stepping thru a program and you think you're getting
+close to the point where things go wrong, you can save a checkpoint.
+Then, if you accidentally go too far and miss the critical statement,
+instead of having to restart your program from the beginning, you can
+just go back to the checkpoint and start again from there.
+
+ This can be especially useful if it takes a lot of time or steps to
+reach the point where you think the bug occurs.
+
+ To use the `checkpoint'/`restart' method of debugging:
+
+`checkpoint'
+ Save a snapshot of the debugged program's current execution state.
+ The `checkpoint' command takes no arguments, but each checkpoint
+ is assigned a small integer id, similar to a breakpoint id.
+
+`info checkpoints'
+ List the checkpoints that have been saved in the current debugging
+ session. For each checkpoint, the following information will be
+ listed:
+
+ `Checkpoint ID'
+
+ `Process ID'
+
+ `Code Address'
+
+ `Source line, or label'
+
+`restart CHECKPOINT-ID'
+ Restore the program state that was saved as checkpoint number
+ CHECKPOINT-ID. All program variables, registers, stack frames
+ etc. will be returned to the values that they had when the
+ checkpoint was saved. In essence, gdb will "wind back the clock"
+ to the point in time when the checkpoint was saved.
+
+ Note that breakpoints, GDB variables, command history etc. are
+ not affected by restoring a checkpoint. In general, a checkpoint
+ only restores things that reside in the program being debugged,
+ not in the debugger.
+
+`delete checkpoint CHECKPOINT-ID'
+ Delete the previously-saved checkpoint identified by CHECKPOINT-ID.
+
+
+ Returning to a previously saved checkpoint will restore the user
+state of the program being debugged, plus a significant subset of the
+system (OS) state, including file pointers. It won't "un-write" data
+from a file, but it will rewind the file pointer to the previous
+location, so that the previously written data can be overwritten. For
+files opened in read mode, the pointer will also be restored so that the
+previously read data can be read again.
+
+ Of course, characters that have been sent to a printer (or other
+external device) cannot be "snatched back", and characters received
+from eg. a serial device can be removed from internal program buffers,
+but they cannot be "pushed back" into the serial pipeline, ready to be
+received again. Similarly, the actual contents of files that have been
+changed cannot be restored (at this time).
+
+ However, within those constraints, you actually can "rewind" your
+program to a previously saved point in time, and begin debugging it
+again -- and you can change the course of events so as to debug a
+different execution path this time.
+
+ Finally, there is one bit of internal program state that will be
+different when you return to a checkpoint -- the program's process id.
+Each checkpoint will have a unique process id (or PID), and each will
+be different from the program's original PID. If your program has
+saved a local copy of its process id, this could potentially pose a
+problem.
+
+4.12.1 A Non-obvious Benefit of Using Checkpoints
+-------------------------------------------------
+
+On some systems such as GNU/Linux, address space randomization is
+performed on new processes for security reasons. This makes it
+difficult or impossible to set a breakpoint, or watchpoint, on an
+absolute address if you have to restart the program, since the absolute
+location of a symbol will change from one execution to the next.
+
+ A checkpoint, however, is an _identical_ copy of a process.
+Therefore if you create a checkpoint at (eg.) the start of main, and
+simply return to that checkpoint instead of restarting the process, you
+can avoid the effects of address randomization and your symbols will
+all stay in the same place.
+
+ ---------- Footnotes ----------
+
+ (1) Currently, only GNU/Linux.
+
+
+File: gdb.info, Node: Stopping, Next: Reverse Execution, Prev: Running, Up: Top
+
+5 Stopping and Continuing
+*************************
+
+The principal purposes of using a debugger are so that you can stop your
+program before it terminates; or so that, if your program runs into
+trouble, you can investigate and find out why.
+
+ Inside GDB, your program may stop for any of several reasons, such
+as a signal, a breakpoint, or reaching a new line after a GDB command
+such as `step'. You may then examine and change variables, set new
+breakpoints or remove old ones, and then continue execution. Usually,
+the messages shown by GDB provide ample explanation of the status of
+your program--but you can also explicitly request this information at
+any time.
+
+`info program'
+ Display information about the status of your program: whether it is
+ running or not, what process it is, and why it stopped.
+
+* Menu:
+
+* Breakpoints:: Breakpoints, watchpoints, and catchpoints
+* Continuing and Stepping:: Resuming execution
+* Skipping Over Functions and Files::
+ Skipping over functions and files
+* Signals:: Signals
+* Thread Stops:: Stopping and starting multi-thread programs
+
+
+File: gdb.info, Node: Breakpoints, Next: Continuing and Stepping, Up: Stopping
+
+5.1 Breakpoints, Watchpoints, and Catchpoints
+=============================================
+
+A "breakpoint" makes your program stop whenever a certain point in the
+program is reached. For each breakpoint, you can add conditions to
+control in finer detail whether your program stops. You can set
+breakpoints with the `break' command and its variants (*note Setting
+Breakpoints: Set Breaks.), to specify the place where your program
+should stop by line number, function name or exact address in the
+program.
+
+ On some systems, you can set breakpoints in shared libraries before
+the executable is run. There is a minor limitation on HP-UX systems:
+you must wait until the executable is run in order to set breakpoints
+in shared library routines that are not called directly by the program
+(for example, routines that are arguments in a `pthread_create' call).
+
+ A "watchpoint" is a special breakpoint that stops your program when
+the value of an expression changes. The expression may be a value of a
+variable, or it could involve values of one or more variables combined
+by operators, such as `a + b'. This is sometimes called "data
+breakpoints". You must use a different command to set watchpoints
+(*note Setting Watchpoints: Set Watchpoints.), but aside from that, you
+can manage a watchpoint like any other breakpoint: you enable, disable,
+and delete both breakpoints and watchpoints using the same commands.
+
+ You can arrange to have values from your program displayed
+automatically whenever GDB stops at a breakpoint. *Note Automatic
+Display: Auto Display.
+
+ A "catchpoint" is another special breakpoint that stops your program
+when a certain kind of event occurs, such as the throwing of a C++
+exception or the loading of a library. As with watchpoints, you use a
+different command to set a catchpoint (*note Setting Catchpoints: Set
+Catchpoints.), but aside from that, you can manage a catchpoint like any
+other breakpoint. (To stop when your program receives a signal, use the
+`handle' command; see *Note Signals: Signals.)
+
+ GDB assigns a number to each breakpoint, watchpoint, or catchpoint
+when you create it; these numbers are successive integers starting with
+one. In many of the commands for controlling various features of
+breakpoints you use the breakpoint number to say which breakpoint you
+want to change. Each breakpoint may be "enabled" or "disabled"; if
+disabled, it has no effect on your program until you enable it again.
+
+ Some GDB commands accept a range of breakpoints on which to operate.
+A breakpoint range is either a single breakpoint number, like `5', or
+two such numbers, in increasing order, separated by a hyphen, like
+`5-7'. When a breakpoint range is given to a command, all breakpoints
+in that range are operated on.
+
+* Menu:
+
+* Set Breaks:: Setting breakpoints
+* Set Watchpoints:: Setting watchpoints
+* Set Catchpoints:: Setting catchpoints
+* Delete Breaks:: Deleting breakpoints
+* Disabling:: Disabling breakpoints
+* Conditions:: Break conditions
+* Break Commands:: Breakpoint command lists
+* Save Breakpoints:: How to save breakpoints in a file
+* Error in Breakpoints:: ``Cannot insert breakpoints''
+* Breakpoint-related Warnings:: ``Breakpoint address adjusted...''
+
+
+File: gdb.info, Node: Set Breaks, Next: Set Watchpoints, Up: Breakpoints
+
+5.1.1 Setting Breakpoints
+-------------------------
+
+Breakpoints are set with the `break' command (abbreviated `b'). The
+debugger convenience variable `$bpnum' records the number of the
+breakpoint you've set most recently; see *Note Convenience Variables:
+Convenience Vars, for a discussion of what you can do with convenience
+variables.
+
+`break LOCATION'
+ Set a breakpoint at the given LOCATION, which can specify a
+ function name, a line number, or an address of an instruction.
+ (*Note Specify Location::, for a list of all the possible ways to
+ specify a LOCATION.) The breakpoint will stop your program just
+ before it executes any of the code in the specified LOCATION.
+
+ When using source languages that permit overloading of symbols,
+ such as C++, a function name may refer to more than one possible
+ place to break. *Note Ambiguous Expressions: Ambiguous
+ Expressions, for a discussion of that situation.
+
+ It is also possible to insert a breakpoint that will stop the
+ program only if a specific thread (*note Thread-Specific
+ Breakpoints::) or a specific task (*note Ada Tasks::) hits that
+ breakpoint.
+
+`break'
+ When called without any arguments, `break' sets a breakpoint at
+ the next instruction to be executed in the selected stack frame
+ (*note Examining the Stack: Stack.). In any selected frame but the
+ innermost, this makes your program stop as soon as control returns
+ to that frame. This is similar to the effect of a `finish'
+ command in the frame inside the selected frame--except that
+ `finish' does not leave an active breakpoint. If you use `break'
+ without an argument in the innermost frame, GDB stops the next
+ time it reaches the current location; this may be useful inside
+ loops.
+
+ GDB normally ignores breakpoints when it resumes execution, until
+ at least one instruction has been executed. If it did not do
+ this, you would be unable to proceed past a breakpoint without
+ first disabling the breakpoint. This rule applies whether or not
+ the breakpoint already existed when your program stopped.
+
+`break ... if COND'
+ Set a breakpoint with condition COND; evaluate the expression COND
+ each time the breakpoint is reached, and stop only if the value is
+ nonzero--that is, if COND evaluates as true. `...' stands for one
+ of the possible arguments described above (or no argument)
+ specifying where to break. *Note Break Conditions: Conditions,
+ for more information on breakpoint conditions.
+
+`tbreak ARGS'
+ Set a breakpoint enabled only for one stop. ARGS are the same as
+ for the `break' command, and the breakpoint is set in the same
+ way, but the breakpoint is automatically deleted after the first
+ time your program stops there. *Note Disabling Breakpoints:
+ Disabling.
+
+`hbreak ARGS'
+ Set a hardware-assisted breakpoint. ARGS are the same as for the
+ `break' command and the breakpoint is set in the same way, but the
+ breakpoint requires hardware support and some target hardware may
+ not have this support. The main purpose of this is EPROM/ROM code
+ debugging, so you can set a breakpoint at an instruction without
+ changing the instruction. This can be used with the new
+ trap-generation provided by SPARClite DSU and most x86-based
+ targets. These targets will generate traps when a program
+ accesses some data or instruction address that is assigned to the
+ debug registers. However the hardware breakpoint registers can
+ take a limited number of breakpoints. For example, on the DSU,
+ only two data breakpoints can be set at a time, and GDB will
+ reject this command if more than two are used. Delete or disable
+ unused hardware breakpoints before setting new ones (*note
+ Disabling Breakpoints: Disabling.). *Note Break Conditions:
+ Conditions. For remote targets, you can restrict the number of
+ hardware breakpoints GDB will use, see *Note set remote
+ hardware-breakpoint-limit::.
+
+`thbreak ARGS'
+ Set a hardware-assisted breakpoint enabled only for one stop. ARGS
+ are the same as for the `hbreak' command and the breakpoint is set
+ in the same way. However, like the `tbreak' command, the
+ breakpoint is automatically deleted after the first time your
+ program stops there. Also, like the `hbreak' command, the
+ breakpoint requires hardware support and some target hardware may
+ not have this support. *Note Disabling Breakpoints: Disabling.
+ See also *Note Break Conditions: Conditions.
+
+`rbreak REGEX'
+ Set breakpoints on all functions matching the regular expression
+ REGEX. This command sets an unconditional breakpoint on all
+ matches, printing a list of all breakpoints it set. Once these
+ breakpoints are set, they are treated just like the breakpoints
+ set with the `break' command. You can delete them, disable them,
+ or make them conditional the same way as any other breakpoint.
+
+ The syntax of the regular expression is the standard one used with
+ tools like `grep'. Note that this is different from the syntax
+ used by shells, so for instance `foo*' matches all functions that
+ include an `fo' followed by zero or more `o's. There is an
+ implicit `.*' leading and trailing the regular expression you
+ supply, so to match only functions that begin with `foo', use
+ `^foo'.
+
+ When debugging C++ programs, `rbreak' is useful for setting
+ breakpoints on overloaded functions that are not members of any
+ special classes.
+
+ The `rbreak' command can be used to set breakpoints in *all* the
+ functions in a program, like this:
+
+ (gdb) rbreak .
+
+`rbreak FILE:REGEX'
+ If `rbreak' is called with a filename qualification, it limits the
+ search for functions matching the given regular expression to the
+ specified FILE. This can be used, for example, to set breakpoints
+ on every function in a given file:
+
+ (gdb) rbreak file.c:.
+
+ The colon separating the filename qualifier from the regex may
+ optionally be surrounded by spaces.
+
+`info breakpoints [N...]'
+`info break [N...]'
+ Print a table of all breakpoints, watchpoints, and catchpoints set
+ and not deleted. Optional argument N means print information only
+ about the specified breakpoint(s) (or watchpoint(s) or
+ catchpoint(s)). For each breakpoint, following columns are
+ printed:
+
+ _Breakpoint Numbers_
+
+ _Type_
+ Breakpoint, watchpoint, or catchpoint.
+
+ _Disposition_
+ Whether the breakpoint is marked to be disabled or deleted
+ when hit.
+
+ _Enabled or Disabled_
+ Enabled breakpoints are marked with `y'. `n' marks
+ breakpoints that are not enabled.
+
+ _Address_
+ Where the breakpoint is in your program, as a memory address.
+ For a pending breakpoint whose address is not yet known,
+ this field will contain `<PENDING>'. Such breakpoint won't
+ fire until a shared library that has the symbol or line
+ referred by breakpoint is loaded. See below for details. A
+ breakpoint with several locations will have `<MULTIPLE>' in
+ this field--see below for details.
+
+ _What_
+ Where the breakpoint is in the source for your program, as a
+ file and line number. For a pending breakpoint, the original
+ string passed to the breakpoint command will be listed as it
+ cannot be resolved until the appropriate shared library is
+ loaded in the future.
+
+ If a breakpoint is conditional, `info break' shows the condition on
+ the line following the affected breakpoint; breakpoint commands,
+ if any, are listed after that. A pending breakpoint is allowed to
+ have a condition specified for it. The condition is not parsed
+ for validity until a shared library is loaded that allows the
+ pending breakpoint to resolve to a valid location.
+
+ `info break' with a breakpoint number N as argument lists only
+ that breakpoint. The convenience variable `$_' and the default
+ examining-address for the `x' command are set to the address of
+ the last breakpoint listed (*note Examining Memory: Memory.).
+
+ `info break' displays a count of the number of times the breakpoint
+ has been hit. This is especially useful in conjunction with the
+ `ignore' command. You can ignore a large number of breakpoint
+ hits, look at the breakpoint info to see how many times the
+ breakpoint was hit, and then run again, ignoring one less than
+ that number. This will get you quickly to the last hit of that
+ breakpoint.
+
+ GDB allows you to set any number of breakpoints at the same place in
+your program. There is nothing silly or meaningless about this. When
+the breakpoints are conditional, this is even useful (*note Break
+Conditions: Conditions.).
+
+ It is possible that a breakpoint corresponds to several locations in
+your program. Examples of this situation are:
+
+ * Multiple functions in the program may have the same name.
+
+ * For a C++ constructor, the GCC compiler generates several
+ instances of the function body, used in different cases.
+
+ * For a C++ template function, a given line in the function can
+ correspond to any number of instantiations.
+
+ * For an inlined function, a given source line can correspond to
+ several places where that function is inlined.
+
+ In all those cases, GDB will insert a breakpoint at all the relevant
+locations.
+
+ A breakpoint with multiple locations is displayed in the breakpoint
+table using several rows--one header row, followed by one row for each
+breakpoint location. The header row has `<MULTIPLE>' in the address
+column. The rows for individual locations contain the actual addresses
+for locations, and show the functions to which those locations belong.
+The number column for a location is of the form
+BREAKPOINT-NUMBER.LOCATION-NUMBER.
+
+ For example:
+
+ Num Type Disp Enb Address What
+ 1 breakpoint keep y <MULTIPLE>
+ stop only if i==1
+ breakpoint already hit 1 time
+ 1.1 y 0x080486a2 in void foo<int>() at t.cc:8
+ 1.2 y 0x080486ca in void foo<double>() at t.cc:8
+
+ Each location can be individually enabled or disabled by passing
+BREAKPOINT-NUMBER.LOCATION-NUMBER as argument to the `enable' and
+`disable' commands. Note that you cannot delete the individual
+locations from the list, you can only delete the entire list of
+locations that belong to their parent breakpoint (with the `delete NUM'
+command, where NUM is the number of the parent breakpoint, 1 in the
+above example). Disabling or enabling the parent breakpoint (*note
+Disabling::) affects all of the locations that belong to that
+breakpoint.
+
+ It's quite common to have a breakpoint inside a shared library.
+Shared libraries can be loaded and unloaded explicitly, and possibly
+repeatedly, as the program is executed. To support this use case, GDB
+updates breakpoint locations whenever any shared library is loaded or
+unloaded. Typically, you would set a breakpoint in a shared library at
+the beginning of your debugging session, when the library is not
+loaded, and when the symbols from the library are not available. When
+you try to set breakpoint, GDB will ask you if you want to set a so
+called "pending breakpoint"--breakpoint whose address is not yet
+resolved.
+
+ After the program is run, whenever a new shared library is loaded,
+GDB reevaluates all the breakpoints. When a newly loaded shared
+library contains the symbol or line referred to by some pending
+breakpoint, that breakpoint is resolved and becomes an ordinary
+breakpoint. When a library is unloaded, all breakpoints that refer to
+its symbols or source lines become pending again.
+
+ This logic works for breakpoints with multiple locations, too. For
+example, if you have a breakpoint in a C++ template function, and a
+newly loaded shared library has an instantiation of that template, a
+new location is added to the list of locations for the breakpoint.
+
+ Except for having unresolved address, pending breakpoints do not
+differ from regular breakpoints. You can set conditions or commands,
+enable and disable them and perform other breakpoint operations.
+
+ GDB provides some additional commands for controlling what happens
+when the `break' command cannot resolve breakpoint address
+specification to an address:
+
+`set breakpoint pending auto'
+ This is the default behavior. When GDB cannot find the breakpoint
+ location, it queries you whether a pending breakpoint should be
+ created.
+
+`set breakpoint pending on'
+ This indicates that an unrecognized breakpoint location should
+ automatically result in a pending breakpoint being created.
+
+`set breakpoint pending off'
+ This indicates that pending breakpoints are not to be created. Any
+ unrecognized breakpoint location results in an error. This
+ setting does not affect any pending breakpoints previously created.
+
+`show breakpoint pending'
+ Show the current behavior setting for creating pending breakpoints.
+
+ The settings above only affect the `break' command and its variants.
+Once breakpoint is set, it will be automatically updated as shared
+libraries are loaded and unloaded.
+
+ For some targets, GDB can automatically decide if hardware or
+software breakpoints should be used, depending on whether the
+breakpoint address is read-only or read-write. This applies to
+breakpoints set with the `break' command as well as to internal
+breakpoints set by commands like `next' and `finish'. For breakpoints
+set with `hbreak', GDB will always use hardware breakpoints.
+
+ You can control this automatic behaviour with the following
+commands::
+
+`set breakpoint auto-hw on'
+ This is the default behavior. When GDB sets a breakpoint, it will
+ try to use the target memory map to decide if software or hardware
+ breakpoint must be used.
+
+`set breakpoint auto-hw off'
+ This indicates GDB should not automatically select breakpoint
+ type. If the target provides a memory map, GDB will warn when
+ trying to set software breakpoint at a read-only address.
+
+ GDB normally implements breakpoints by replacing the program code at
+the breakpoint address with a special instruction, which, when
+executed, given control to the debugger. By default, the program code
+is so modified only when the program is resumed. As soon as the
+program stops, GDB restores the original instructions. This behaviour
+guards against leaving breakpoints inserted in the target should gdb
+abrubptly disconnect. However, with slow remote targets, inserting and
+removing breakpoint can reduce the performance. This behavior can be
+controlled with the following commands::
+
+`set breakpoint always-inserted off'
+ All breakpoints, including newly added by the user, are inserted in
+ the target only when the target is resumed. All breakpoints are
+ removed from the target when it stops.
+
+`set breakpoint always-inserted on'
+ Causes all breakpoints to be inserted in the target at all times.
+ If the user adds a new breakpoint, or changes an existing
+ breakpoint, the breakpoints in the target are updated immediately.
+ A breakpoint is removed from the target only when breakpoint
+ itself is removed.
+
+`set breakpoint always-inserted auto'
+ This is the default mode. If GDB is controlling the inferior in
+ non-stop mode (*note Non-Stop Mode::), gdb behaves as if
+ `breakpoint always-inserted' mode is on. If GDB is controlling
+ the inferior in all-stop mode, GDB behaves as if `breakpoint
+ always-inserted' mode is off.
+
+ GDB itself sometimes sets breakpoints in your program for special
+purposes, such as proper handling of `longjmp' (in C programs). These
+internal breakpoints are assigned negative numbers, starting with `-1';
+`info breakpoints' does not display them. You can see these
+breakpoints with the GDB maintenance command `maint info breakpoints'
+(*note maint info breakpoints::).
+
+
+File: gdb.info, Node: Set Watchpoints, Next: Set Catchpoints, Prev: Set Breaks, Up: Breakpoints
+
+5.1.2 Setting Watchpoints
+-------------------------
+
+You can use a watchpoint to stop execution whenever the value of an
+expression changes, without having to predict a particular place where
+this may happen. (This is sometimes called a "data breakpoint".) The
+expression may be as simple as the value of a single variable, or as
+complex as many variables combined by operators. Examples include:
+
+ * A reference to the value of a single variable.
+
+ * An address cast to an appropriate data type. For example, `*(int
+ *)0x12345678' will watch a 4-byte region at the specified address
+ (assuming an `int' occupies 4 bytes).
+
+ * An arbitrarily complex expression, such as `a*b + c/d'. The
+ expression can use any operators valid in the program's native
+ language (*note Languages::).
+
+ You can set a watchpoint on an expression even if the expression can
+not be evaluated yet. For instance, you can set a watchpoint on
+`*global_ptr' before `global_ptr' is initialized. GDB will stop when
+your program sets `global_ptr' and the expression produces a valid
+value. If the expression becomes valid in some other way than changing
+a variable (e.g. if the memory pointed to by `*global_ptr' becomes
+readable as the result of a `malloc' call), GDB may not stop until the
+next time the expression changes.
+
+ Depending on your system, watchpoints may be implemented in software
+or hardware. GDB does software watchpointing by single-stepping your
+program and testing the variable's value each time, which is hundreds of
+times slower than normal execution. (But this may still be worth it, to
+catch errors where you have no clue what part of your program is the
+culprit.)
+
+ On some systems, such as HP-UX, PowerPC, GNU/Linux and most other
+x86-based targets, GDB includes support for hardware watchpoints, which
+do not slow down the running of your program.
+
+`watch [-l|-location] EXPR [thread THREADNUM] [mask MASKVALUE]'
+ Set a watchpoint for an expression. GDB will break when the
+ expression EXPR is written into by the program and its value
+ changes. The simplest (and the most popular) use of this command
+ is to watch the value of a single variable:
+
+ (gdb) watch foo
+
+ If the command includes a `[thread THREADNUM]' argument, GDB
+ breaks only when the thread identified by THREADNUM changes the
+ value of EXPR. If any other threads change the value of EXPR, GDB
+ will not break. Note that watchpoints restricted to a single
+ thread in this way only work with Hardware Watchpoints.
+
+ Ordinarily a watchpoint respects the scope of variables in EXPR
+ (see below). The `-location' argument tells GDB to instead watch
+ the memory referred to by EXPR. In this case, GDB will evaluate
+ EXPR, take the address of the result, and watch the memory at that
+ address. The type of the result is used to determine the size of
+ the watched memory. If the expression's result does not have an
+ address, then GDB will print an error.
+
+ The `[mask MASKVALUE]' argument allows creation of masked
+ watchpoints, if the current architecture supports this feature
+ (e.g., PowerPC Embedded architecture, see *Note PowerPC
+ Embedded::.) A "masked watchpoint" specifies a mask in addition
+ to an address to watch. The mask specifies that some bits of an
+ address (the bits which are reset in the mask) should be ignored
+ when matching the address accessed by the inferior against the
+ watchpoint address. Thus, a masked watchpoint watches many
+ addresses simultaneously--those addresses whose unmasked bits are
+ identical to the unmasked bits in the watchpoint address. The
+ `mask' argument implies `-location'. Examples:
+
+ (gdb) watch foo mask 0xffff00ff
+ (gdb) watch *0xdeadbeef mask 0xffffff00
+
+`rwatch [-l|-location] EXPR [thread THREADNUM] [mask MASKVALUE]'
+ Set a watchpoint that will break when the value of EXPR is read by
+ the program.
+
+`awatch [-l|-location] EXPR [thread THREADNUM] [mask MASKVALUE]'
+ Set a watchpoint that will break when EXPR is either read from or
+ written into by the program.
+
+`info watchpoints [N...]'
+ This command prints a list of watchpoints, using the same format as
+ `info break' (*note Set Breaks::).
+
+ If you watch for a change in a numerically entered address you need
+to dereference it, as the address itself is just a constant number
+which will never change. GDB refuses to create a watchpoint that
+watches a never-changing value:
+
+ (gdb) watch 0x600850
+ Cannot watch constant value 0x600850.
+ (gdb) watch *(int *) 0x600850
+ Watchpoint 1: *(int *) 6293584
+
+ GDB sets a "hardware watchpoint" if possible. Hardware watchpoints
+execute very quickly, and the debugger reports a change in value at the
+exact instruction where the change occurs. If GDB cannot set a
+hardware watchpoint, it sets a software watchpoint, which executes more
+slowly and reports the change in value at the next _statement_, not the
+instruction, after the change occurs.
+
+ You can force GDB to use only software watchpoints with the `set
+can-use-hw-watchpoints 0' command. With this variable set to zero, GDB
+will never try to use hardware watchpoints, even if the underlying
+system supports them. (Note that hardware-assisted watchpoints that
+were set _before_ setting `can-use-hw-watchpoints' to zero will still
+use the hardware mechanism of watching expression values.)
+
+`set can-use-hw-watchpoints'
+ Set whether or not to use hardware watchpoints.
+
+`show can-use-hw-watchpoints'
+ Show the current mode of using hardware watchpoints.
+
+ For remote targets, you can restrict the number of hardware
+watchpoints GDB will use, see *Note set remote
+hardware-breakpoint-limit::.
+
+ When you issue the `watch' command, GDB reports
+
+ Hardware watchpoint NUM: EXPR
+
+if it was able to set a hardware watchpoint.
+
+ Currently, the `awatch' and `rwatch' commands can only set hardware
+watchpoints, because accesses to data that don't change the value of
+the watched expression cannot be detected without examining every
+instruction as it is being executed, and GDB does not do that
+currently. If GDB finds that it is unable to set a hardware breakpoint
+with the `awatch' or `rwatch' command, it will print a message like
+this:
+
+ Expression cannot be implemented with read/access watchpoint.
+
+ Sometimes, GDB cannot set a hardware watchpoint because the data
+type of the watched expression is wider than what a hardware watchpoint
+on the target machine can handle. For example, some systems can only
+watch regions that are up to 4 bytes wide; on such systems you cannot
+set hardware watchpoints for an expression that yields a
+double-precision floating-point number (which is typically 8 bytes
+wide). As a work-around, it might be possible to break the large region
+into a series of smaller ones and watch them with separate watchpoints.
+
+ If you set too many hardware watchpoints, GDB might be unable to
+insert all of them when you resume the execution of your program.
+Since the precise number of active watchpoints is unknown until such
+time as the program is about to be resumed, GDB might not be able to
+warn you about this when you set the watchpoints, and the warning will
+be printed only when the program is resumed:
+
+ Hardware watchpoint NUM: Could not insert watchpoint
+
+If this happens, delete or disable some of the watchpoints.
+
+ Watching complex expressions that reference many variables can also
+exhaust the resources available for hardware-assisted watchpoints.
+That's because GDB needs to watch every variable in the expression with
+separately allocated resources.
+
+ If you call a function interactively using `print' or `call', any
+watchpoints you have set will be inactive until GDB reaches another
+kind of breakpoint or the call completes.
+
+ GDB automatically deletes watchpoints that watch local (automatic)
+variables, or expressions that involve such variables, when they go out
+of scope, that is, when the execution leaves the block in which these
+variables were defined. In particular, when the program being debugged
+terminates, _all_ local variables go out of scope, and so only
+watchpoints that watch global variables remain set. If you rerun the
+program, you will need to set all such watchpoints again. One way of
+doing that would be to set a code breakpoint at the entry to the `main'
+function and when it breaks, set all the watchpoints.
+
+ In multi-threaded programs, watchpoints will detect changes to the
+watched expression from every thread.
+
+ _Warning:_ In multi-threaded programs, software watchpoints have
+ only limited usefulness. If GDB creates a software watchpoint, it
+ can only watch the value of an expression _in a single thread_.
+ If you are confident that the expression can only change due to
+ the current thread's activity (and if you are also confident that
+ no other thread can become current), then you can use software
+ watchpoints as usual. However, GDB may not notice when a
+ non-current thread's activity changes the expression. (Hardware
+ watchpoints, in contrast, watch an expression in all threads.)
+
+ *Note set remote hardware-watchpoint-limit::.
+
+
+File: gdb.info, Node: Set Catchpoints, Next: Delete Breaks, Prev: Set Watchpoints, Up: Breakpoints
+
+5.1.3 Setting Catchpoints
+-------------------------
+
+You can use "catchpoints" to cause the debugger to stop for certain
+kinds of program events, such as C++ exceptions or the loading of a
+shared library. Use the `catch' command to set a catchpoint.
+
+`catch EVENT'
+ Stop when EVENT occurs. EVENT can be any of the following:
+ `throw'
+ The throwing of a C++ exception.
+
+ `catch'
+ The catching of a C++ exception.
+
+ `exception'
+ An Ada exception being raised. If an exception name is
+ specified at the end of the command (eg `catch exception
+ Program_Error'), the debugger will stop only when this
+ specific exception is raised. Otherwise, the debugger stops
+ execution when any Ada exception is raised.
+
+ When inserting an exception catchpoint on a user-defined
+ exception whose name is identical to one of the exceptions
+ defined by the language, the fully qualified name must be
+ used as the exception name. Otherwise, GDB will assume that
+ it should stop on the pre-defined exception rather than the
+ user-defined one. For instance, assuming an exception called
+ `Constraint_Error' is defined in package `Pck', then the
+ command to use to catch such exceptions is `catch exception
+ Pck.Constraint_Error'.
+
+ `exception unhandled'
+ An exception that was raised but is not handled by the
+ program.
+
+ `assert'
+ A failed Ada assertion.
+
+ `exec'
+ A call to `exec'. This is currently only available for HP-UX
+ and GNU/Linux.
+
+ `syscall'
+ `syscall [NAME | NUMBER] ...'
+ A call to or return from a system call, a.k.a. "syscall". A
+ syscall is a mechanism for application programs to request a
+ service from the operating system (OS) or one of the OS
+ system services. GDB can catch some or all of the syscalls
+ issued by the debuggee, and show the related information for
+ each syscall. If no argument is specified, calls to and
+ returns from all system calls will be caught.
+
+ NAME can be any system call name that is valid for the
+ underlying OS. Just what syscalls are valid depends on the
+ OS. On GNU and Unix systems, you can find the full list of
+ valid syscall names on `/usr/include/asm/unistd.h'.
+
+ Normally, GDB knows in advance which syscalls are valid for
+ each OS, so you can use the GDB command-line completion
+ facilities (*note command completion: Completion.) to list the
+ available choices.
+
+ You may also specify the system call numerically. A syscall's
+ number is the value passed to the OS's syscall dispatcher to
+ identify the requested service. When you specify the syscall
+ by its name, GDB uses its database of syscalls to convert the
+ name into the corresponding numeric code, but using the
+ number directly may be useful if GDB's database does not have
+ the complete list of syscalls on your system (e.g., because
+ GDB lags behind the OS upgrades).
+
+ The example below illustrates how this command works if you
+ don't provide arguments to it:
+
+ (gdb) catch syscall
+ Catchpoint 1 (syscall)
+ (gdb) r
+ Starting program: /tmp/catch-syscall
+
+ Catchpoint 1 (call to syscall 'close'), \
+ 0xffffe424 in __kernel_vsyscall ()
+ (gdb) c
+ Continuing.
+
+ Catchpoint 1 (returned from syscall 'close'), \
+ 0xffffe424 in __kernel_vsyscall ()
+ (gdb)
+
+ Here is an example of catching a system call by name:
+
+ (gdb) catch syscall chroot
+ Catchpoint 1 (syscall 'chroot' [61])
+ (gdb) r
+ Starting program: /tmp/catch-syscall
+
+ Catchpoint 1 (call to syscall 'chroot'), \
+ 0xffffe424 in __kernel_vsyscall ()
+ (gdb) c
+ Continuing.
+
+ Catchpoint 1 (returned from syscall 'chroot'), \
+ 0xffffe424 in __kernel_vsyscall ()
+ (gdb)
+
+ An example of specifying a system call numerically. In the
+ case below, the syscall number has a corresponding entry in
+ the XML file, so GDB finds its name and prints it:
+
+ (gdb) catch syscall 252
+ Catchpoint 1 (syscall(s) 'exit_group')
+ (gdb) r
+ Starting program: /tmp/catch-syscall
+
+ Catchpoint 1 (call to syscall 'exit_group'), \
+ 0xffffe424 in __kernel_vsyscall ()
+ (gdb) c
+ Continuing.
+
+ Program exited normally.
+ (gdb)
+
+ However, there can be situations when there is no
+ corresponding name in XML file for that syscall number. In
+ this case, GDB prints a warning message saying that it was
+ not able to find the syscall name, but the catchpoint will be
+ set anyway. See the example below:
+
+ (gdb) catch syscall 764
+ warning: The number '764' does not represent a known syscall.
+ Catchpoint 2 (syscall 764)
+ (gdb)
+
+ If you configure GDB using the `--without-expat' option, it
+ will not be able to display syscall names. Also, if your
+ architecture does not have an XML file describing its system
+ calls, you will not be able to see the syscall names. It is
+ important to notice that these two features are used for
+ accessing the syscall name database. In either case, you
+ will see a warning like this:
+
+ (gdb) catch syscall
+ warning: Could not open "syscalls/i386-linux.xml"
+ warning: Could not load the syscall XML file 'syscalls/i386-linux.xml'.
+ GDB will not be able to display syscall names.
+ Catchpoint 1 (syscall)
+ (gdb)
+
+ Of course, the file name will change depending on your
+ architecture and system.
+
+ Still using the example above, you can also try to catch a
+ syscall by its number. In this case, you would see something
+ like:
+
+ (gdb) catch syscall 252
+ Catchpoint 1 (syscall(s) 252)
+
+ Again, in this case GDB would not be able to display
+ syscall's names.
+
+ `fork'
+ A call to `fork'. This is currently only available for HP-UX
+ and GNU/Linux.
+
+ `vfork'
+ A call to `vfork'. This is currently only available for HP-UX
+ and GNU/Linux.
+
+
+`tcatch EVENT'
+ Set a catchpoint that is enabled only for one stop. The
+ catchpoint is automatically deleted after the first time the event
+ is caught.
+
+
+ Use the `info break' command to list the current catchpoints.
+
+ There are currently some limitations to C++ exception handling
+(`catch throw' and `catch catch') in GDB:
+
+ * If you call a function interactively, GDB normally returns control
+ to you when the function has finished executing. If the call
+ raises an exception, however, the call may bypass the mechanism
+ that returns control to you and cause your program either to abort
+ or to simply continue running until it hits a breakpoint, catches
+ a signal that GDB is listening for, or exits. This is the case
+ even if you set a catchpoint for the exception; catchpoints on
+ exceptions are disabled within interactive calls.
+
+ * You cannot raise an exception interactively.
+
+ * You cannot install an exception handler interactively.
+
+ Sometimes `catch' is not the best way to debug exception handling:
+if you need to know exactly where an exception is raised, it is better
+to stop _before_ the exception handler is called, since that way you
+can see the stack before any unwinding takes place. If you set a
+breakpoint in an exception handler instead, it may not be easy to find
+out where the exception was raised.
+
+ To stop just before an exception handler is called, you need some
+knowledge of the implementation. In the case of GNU C++, exceptions are
+raised by calling a library function named `__raise_exception' which
+has the following ANSI C interface:
+
+ /* ADDR is where the exception identifier is stored.
+ ID is the exception identifier. */
+ void __raise_exception (void **addr, void *id);
+
+To make the debugger catch all exceptions before any stack unwinding
+takes place, set a breakpoint on `__raise_exception' (*note
+Breakpoints; Watchpoints; and Exceptions: Breakpoints.).
+
+ With a conditional breakpoint (*note Break Conditions: Conditions.)
+that depends on the value of ID, you can stop your program when a
+specific exception is raised. You can use multiple conditional
+breakpoints to stop your program when any of a number of exceptions are
+raised.
+
+
+File: gdb.info, Node: Delete Breaks, Next: Disabling, Prev: Set Catchpoints, Up: Breakpoints
+
+5.1.4 Deleting Breakpoints
+--------------------------
+
+It is often necessary to eliminate a breakpoint, watchpoint, or
+catchpoint once it has done its job and you no longer want your program
+to stop there. This is called "deleting" the breakpoint. A breakpoint
+that has been deleted no longer exists; it is forgotten.
+
+ With the `clear' command you can delete breakpoints according to
+where they are in your program. With the `delete' command you can
+delete individual breakpoints, watchpoints, or catchpoints by specifying
+their breakpoint numbers.
+
+ It is not necessary to delete a breakpoint to proceed past it. GDB
+automatically ignores breakpoints on the first instruction to be
+executed when you continue execution without changing the execution
+address.
+
+`clear'
+ Delete any breakpoints at the next instruction to be executed in
+ the selected stack frame (*note Selecting a Frame: Selection.).
+ When the innermost frame is selected, this is a good way to delete
+ a breakpoint where your program just stopped.
+
+`clear LOCATION'
+ Delete any breakpoints set at the specified LOCATION. *Note
+ Specify Location::, for the various forms of LOCATION; the most
+ useful ones are listed below:
+
+ `clear FUNCTION'
+ `clear FILENAME:FUNCTION'
+ Delete any breakpoints set at entry to the named FUNCTION.
+
+ `clear LINENUM'
+ `clear FILENAME:LINENUM'
+ Delete any breakpoints set at or within the code of the
+ specified LINENUM of the specified FILENAME.
+
+`delete [breakpoints] [RANGE...]'
+ Delete the breakpoints, watchpoints, or catchpoints of the
+ breakpoint ranges specified as arguments. If no argument is
+ specified, delete all breakpoints (GDB asks confirmation, unless
+ you have `set confirm off'). You can abbreviate this command as
+ `d'.
+
+
+File: gdb.info, Node: Disabling, Next: Conditions, Prev: Delete Breaks, Up: Breakpoints
+
+5.1.5 Disabling Breakpoints
+---------------------------
+
+Rather than deleting a breakpoint, watchpoint, or catchpoint, you might
+prefer to "disable" it. This makes the breakpoint inoperative as if it
+had been deleted, but remembers the information on the breakpoint so
+that you can "enable" it again later.
+
+ You disable and enable breakpoints, watchpoints, and catchpoints with
+the `enable' and `disable' commands, optionally specifying one or more
+breakpoint numbers as arguments. Use `info break' to print a list of
+all breakpoints, watchpoints, and catchpoints if you do not know which
+numbers to use.
+
+ Disabling and enabling a breakpoint that has multiple locations
+affects all of its locations.
+
+ A breakpoint, watchpoint, or catchpoint can have any of four
+different states of enablement:
+
+ * Enabled. The breakpoint stops your program. A breakpoint set
+ with the `break' command starts out in this state.
+
+ * Disabled. The breakpoint has no effect on your program.
+
+ * Enabled once. The breakpoint stops your program, but then becomes
+ disabled.
+
+ * Enabled for deletion. The breakpoint stops your program, but
+ immediately after it does so it is deleted permanently. A
+ breakpoint set with the `tbreak' command starts out in this state.
+
+ You can use the following commands to enable or disable breakpoints,
+watchpoints, and catchpoints:
+
+`disable [breakpoints] [RANGE...]'
+ Disable the specified breakpoints--or all breakpoints, if none are
+ listed. A disabled breakpoint has no effect but is not forgotten.
+ All options such as ignore-counts, conditions and commands are
+ remembered in case the breakpoint is enabled again later. You may
+ abbreviate `disable' as `dis'.
+
+`enable [breakpoints] [RANGE...]'
+ Enable the specified breakpoints (or all defined breakpoints).
+ They become effective once again in stopping your program.
+
+`enable [breakpoints] once RANGE...'
+ Enable the specified breakpoints temporarily. GDB disables any of
+ these breakpoints immediately after stopping your program.
+
+`enable [breakpoints] delete RANGE...'
+ Enable the specified breakpoints to work once, then die. GDB
+ deletes any of these breakpoints as soon as your program stops
+ there. Breakpoints set by the `tbreak' command start out in this
+ state.
+
+ Except for a breakpoint set with `tbreak' (*note Setting
+Breakpoints: Set Breaks.), breakpoints that you set are initially
+enabled; subsequently, they become disabled or enabled only when you
+use one of the commands above. (The command `until' can set and delete
+a breakpoint of its own, but it does not change the state of your other
+breakpoints; see *Note Continuing and Stepping: Continuing and
+Stepping.)
+
+
+File: gdb.info, Node: Conditions, Next: Break Commands, Prev: Disabling, Up: Breakpoints
+
+5.1.6 Break Conditions
+----------------------
+
+The simplest sort of breakpoint breaks every time your program reaches a
+specified place. You can also specify a "condition" for a breakpoint.
+A condition is just a Boolean expression in your programming language
+(*note Expressions: Expressions.). A breakpoint with a condition
+evaluates the expression each time your program reaches it, and your
+program stops only if the condition is _true_.
+
+ This is the converse of using assertions for program validation; in
+that situation, you want to stop when the assertion is violated--that
+is, when the condition is false. In C, if you want to test an
+assertion expressed by the condition ASSERT, you should set the
+condition `! ASSERT' on the appropriate breakpoint.
+
+ Conditions are also accepted for watchpoints; you may not need them,
+since a watchpoint is inspecting the value of an expression anyhow--but
+it might be simpler, say, to just set a watchpoint on a variable name,
+and specify a condition that tests whether the new value is an
+interesting one.
+
+ Break conditions can have side effects, and may even call functions
+in your program. This can be useful, for example, to activate functions
+that log program progress, or to use your own print functions to format
+special data structures. The effects are completely predictable unless
+there is another enabled breakpoint at the same address. (In that
+case, GDB might see the other breakpoint first and stop your program
+without checking the condition of this one.) Note that breakpoint
+commands are usually more convenient and flexible than break conditions
+for the purpose of performing side effects when a breakpoint is reached
+(*note Breakpoint Command Lists: Break Commands.).
+
+ Break conditions can be specified when a breakpoint is set, by using
+`if' in the arguments to the `break' command. *Note Setting
+Breakpoints: Set Breaks. They can also be changed at any time with the
+`condition' command.
+
+ You can also use the `if' keyword with the `watch' command. The
+`catch' command does not recognize the `if' keyword; `condition' is the
+only way to impose a further condition on a catchpoint.
+
+`condition BNUM EXPRESSION'
+ Specify EXPRESSION as the break condition for breakpoint,
+ watchpoint, or catchpoint number BNUM. After you set a condition,
+ breakpoint BNUM stops your program only if the value of EXPRESSION
+ is true (nonzero, in C). When you use `condition', GDB checks
+ EXPRESSION immediately for syntactic correctness, and to determine
+ whether symbols in it have referents in the context of your
+ breakpoint. If EXPRESSION uses symbols not referenced in the
+ context of the breakpoint, GDB prints an error message:
+
+ No symbol "foo" in current context.
+
+ GDB does not actually evaluate EXPRESSION at the time the
+ `condition' command (or a command that sets a breakpoint with a
+ condition, like `break if ...') is given, however. *Note
+ Expressions: Expressions.
+
+`condition BNUM'
+ Remove the condition from breakpoint number BNUM. It becomes an
+ ordinary unconditional breakpoint.
+
+ A special case of a breakpoint condition is to stop only when the
+breakpoint has been reached a certain number of times. This is so
+useful that there is a special way to do it, using the "ignore count"
+of the breakpoint. Every breakpoint has an ignore count, which is an
+integer. Most of the time, the ignore count is zero, and therefore has
+no effect. But if your program reaches a breakpoint whose ignore count
+is positive, then instead of stopping, it just decrements the ignore
+count by one and continues. As a result, if the ignore count value is
+N, the breakpoint does not stop the next N times your program reaches
+it.
+
+`ignore BNUM COUNT'
+ Set the ignore count of breakpoint number BNUM to COUNT. The next
+ COUNT times the breakpoint is reached, your program's execution
+ does not stop; other than to decrement the ignore count, GDB takes
+ no action.
+
+ To make the breakpoint stop the next time it is reached, specify a
+ count of zero.
+
+ When you use `continue' to resume execution of your program from a
+ breakpoint, you can specify an ignore count directly as an
+ argument to `continue', rather than using `ignore'. *Note
+ Continuing and Stepping: Continuing and Stepping.
+
+ If a breakpoint has a positive ignore count and a condition, the
+ condition is not checked. Once the ignore count reaches zero, GDB
+ resumes checking the condition.
+
+ You could achieve the effect of the ignore count with a condition
+ such as `$foo-- <= 0' using a debugger convenience variable that
+ is decremented each time. *Note Convenience Variables:
+ Convenience Vars.
+
+ Ignore counts apply to breakpoints, watchpoints, and catchpoints.
+
+
+File: gdb.info, Node: Break Commands, Next: Save Breakpoints, Prev: Conditions, Up: Breakpoints
+
+5.1.7 Breakpoint Command Lists
+------------------------------
+
+You can give any breakpoint (or watchpoint or catchpoint) a series of
+commands to execute when your program stops due to that breakpoint. For
+example, you might want to print the values of certain expressions, or
+enable other breakpoints.
+
+`commands [RANGE...]'
+`... COMMAND-LIST ...'
+`end'
+ Specify a list of commands for the given breakpoints. The commands
+ themselves appear on the following lines. Type a line containing
+ just `end' to terminate the commands.
+
+ To remove all commands from a breakpoint, type `commands' and
+ follow it immediately with `end'; that is, give no commands.
+
+ With no argument, `commands' refers to the last breakpoint,
+ watchpoint, or catchpoint set (not to the breakpoint most recently
+ encountered). If the most recent breakpoints were set with a
+ single command, then the `commands' will apply to all the
+ breakpoints set by that command. This applies to breakpoints set
+ by `rbreak', and also applies when a single `break' command
+ creates multiple breakpoints (*note Ambiguous Expressions:
+ Ambiguous Expressions.).
+
+ Pressing <RET> as a means of repeating the last GDB command is
+disabled within a COMMAND-LIST.
+
+ You can use breakpoint commands to start your program up again.
+Simply use the `continue' command, or `step', or any other command that
+resumes execution.
+
+ Any other commands in the command list, after a command that resumes
+execution, are ignored. This is because any time you resume execution
+(even with a simple `next' or `step'), you may encounter another
+breakpoint--which could have its own command list, leading to
+ambiguities about which list to execute.
+
+ If the first command you specify in a command list is `silent', the
+usual message about stopping at a breakpoint is not printed. This may
+be desirable for breakpoints that are to print a specific message and
+then continue. If none of the remaining commands print anything, you
+see no sign that the breakpoint was reached. `silent' is meaningful
+only at the beginning of a breakpoint command list.
+
+ The commands `echo', `output', and `printf' allow you to print
+precisely controlled output, and are often useful in silent
+breakpoints. *Note Commands for Controlled Output: Output.
+
+ For example, here is how you could use breakpoint commands to print
+the value of `x' at entry to `foo' whenever `x' is positive.
+
+ break foo if x>0
+ commands
+ silent
+ printf "x is %d\n",x
+ cont
+ end
+
+ One application for breakpoint commands is to compensate for one bug
+so you can test for another. Put a breakpoint just after the erroneous
+line of code, give it a condition to detect the case in which something
+erroneous has been done, and give it commands to assign correct values
+to any variables that need them. End with the `continue' command so
+that your program does not stop, and start with the `silent' command so
+that no output is produced. Here is an example:
+
+ break 403
+ commands
+ silent
+ set x = y + 4
+ cont
+ end
+
+
+File: gdb.info, Node: Save Breakpoints, Next: Error in Breakpoints, Prev: Break Commands, Up: Breakpoints
+
+5.1.8 How to save breakpoints to a file
+---------------------------------------
+
+To save breakpoint definitions to a file use the `save breakpoints'
+command.
+
+`save breakpoints [FILENAME]'
+ This command saves all current breakpoint definitions together with
+ their commands and ignore counts, into a file `FILENAME' suitable
+ for use in a later debugging session. This includes all types of
+ breakpoints (breakpoints, watchpoints, catchpoints, tracepoints).
+ To read the saved breakpoint definitions, use the `source' command
+ (*note Command Files::). Note that watchpoints with expressions
+ involving local variables may fail to be recreated because it may
+ not be possible to access the context where the watchpoint is
+ valid anymore. Because the saved breakpoint definitions are
+ simply a sequence of GDB commands that recreate the breakpoints,
+ you can edit the file in your favorite editing program, and remove
+ the breakpoint definitions you're not interested in, or that can
+ no longer be recreated.
+
+
+File: gdb.info, Node: Error in Breakpoints, Next: Breakpoint-related Warnings, Prev: Save Breakpoints, Up: Breakpoints
+
+5.1.9 "Cannot insert breakpoints"
+---------------------------------
+
+If you request too many active hardware-assisted breakpoints and
+watchpoints, you will see this error message:
+
+ Stopped; cannot insert breakpoints.
+ You may have requested too many hardware breakpoints and watchpoints.
+
+This message is printed when you attempt to resume the program, since
+only then GDB knows exactly how many hardware breakpoints and
+watchpoints it needs to insert.
+
+ When this message is printed, you need to disable or remove some of
+the hardware-assisted breakpoints and watchpoints, and then continue.
+
+
+File: gdb.info, Node: Breakpoint-related Warnings, Prev: Error in Breakpoints, Up: Breakpoints
+
+5.1.10 "Breakpoint address adjusted..."
+---------------------------------------
+
+Some processor architectures place constraints on the addresses at
+which breakpoints may be placed. For architectures thus constrained,
+GDB will attempt to adjust the breakpoint's address to comply with the
+constraints dictated by the architecture.
+
+ One example of such an architecture is the Fujitsu FR-V. The FR-V is
+a VLIW architecture in which a number of RISC-like instructions may be
+bundled together for parallel execution. The FR-V architecture
+constrains the location of a breakpoint instruction within such a
+bundle to the instruction with the lowest address. GDB honors this
+constraint by adjusting a breakpoint's address to the first in the
+bundle.
+
+ It is not uncommon for optimized code to have bundles which contain
+instructions from different source statements, thus it may happen that
+a breakpoint's address will be adjusted from one source statement to
+another. Since this adjustment may significantly alter GDB's
+breakpoint related behavior from what the user expects, a warning is
+printed when the breakpoint is first set and also when the breakpoint
+is hit.
+
+ A warning like the one below is printed when setting a breakpoint
+that's been subject to address adjustment:
+
+ warning: Breakpoint address adjusted from 0x00010414 to 0x00010410.
+
+ Such warnings are printed both for user settable and GDB's internal
+breakpoints. If you see one of these warnings, you should verify that
+a breakpoint set at the adjusted address will have the desired affect.
+If not, the breakpoint in question may be removed and other breakpoints
+may be set which will have the desired behavior. E.g., it may be
+sufficient to place the breakpoint at a later instruction. A
+conditional breakpoint may also be useful in some cases to prevent the
+breakpoint from triggering too often.
+
+ GDB will also issue a warning when stopping at one of these adjusted
+breakpoints:
+
+ warning: Breakpoint 1 address previously adjusted from 0x00010414
+ to 0x00010410.
+
+ When this warning is encountered, it may be too late to take remedial
+action except in cases where the breakpoint is hit earlier or more
+frequently than expected.
+
+
+File: gdb.info, Node: Continuing and Stepping, Next: Skipping Over Functions and Files, Prev: Breakpoints, Up: Stopping
+
+5.2 Continuing and Stepping
+===========================
+
+"Continuing" means resuming program execution until your program
+completes normally. In contrast, "stepping" means executing just one
+more "step" of your program, where "step" may mean either one line of
+source code, or one machine instruction (depending on what particular
+command you use). Either when continuing or when stepping, your
+program may stop even sooner, due to a breakpoint or a signal. (If it
+stops due to a signal, you may want to use `handle', or use `signal 0'
+to resume execution. *Note Signals: Signals.)
+
+`continue [IGNORE-COUNT]'
+`c [IGNORE-COUNT]'
+`fg [IGNORE-COUNT]'
+ Resume program execution, at the address where your program last
+ stopped; any breakpoints set at that address are bypassed. The
+ optional argument IGNORE-COUNT allows you to specify a further
+ number of times to ignore a breakpoint at this location; its
+ effect is like that of `ignore' (*note Break Conditions:
+ Conditions.).
+
+ The argument IGNORE-COUNT is meaningful only when your program
+ stopped due to a breakpoint. At other times, the argument to
+ `continue' is ignored.
+
+ The synonyms `c' and `fg' (for "foreground", as the debugged
+ program is deemed to be the foreground program) are provided
+ purely for convenience, and have exactly the same behavior as
+ `continue'.
+
+ To resume execution at a different place, you can use `return'
+(*note Returning from a Function: Returning.) to go back to the calling
+function; or `jump' (*note Continuing at a Different Address: Jumping.)
+to go to an arbitrary location in your program.
+
+ A typical technique for using stepping is to set a breakpoint (*note
+Breakpoints; Watchpoints; and Catchpoints: Breakpoints.) at the
+beginning of the function or the section of your program where a problem
+is believed to lie, run your program until it stops at that breakpoint,
+and then step through the suspect area, examining the variables that are
+interesting, until you see the problem happen.
+
+`step'
+ Continue running your program until control reaches a different
+ source line, then stop it and return control to GDB. This command
+ is abbreviated `s'.
+
+ _Warning:_ If you use the `step' command while control is
+ within a function that was compiled without debugging
+ information, execution proceeds until control reaches a
+ function that does have debugging information. Likewise, it
+ will not step into a function which is compiled without
+ debugging information. To step through functions without
+ debugging information, use the `stepi' command, described
+ below.
+
+ The `step' command only stops at the first instruction of a source
+ line. This prevents the multiple stops that could otherwise occur
+ in `switch' statements, `for' loops, etc. `step' continues to
+ stop if a function that has debugging information is called within
+ the line. In other words, `step' _steps inside_ any functions
+ called within the line.
+
+ Also, the `step' command only enters a function if there is line
+ number information for the function. Otherwise it acts like the
+ `next' command. This avoids problems when using `cc -gl' on MIPS
+ machines. Previously, `step' entered subroutines if there was any
+ debugging information about the routine.
+
+`step COUNT'
+ Continue running as in `step', but do so COUNT times. If a
+ breakpoint is reached, or a signal not related to stepping occurs
+ before COUNT steps, stepping stops right away.
+
+`next [COUNT]'
+ Continue to the next source line in the current (innermost) stack
+ frame. This is similar to `step', but function calls that appear
+ within the line of code are executed without stopping. Execution
+ stops when control reaches a different line of code at the
+ original stack level that was executing when you gave the `next'
+ command. This command is abbreviated `n'.
+
+ An argument COUNT is a repeat count, as for `step'.
+
+ The `next' command only stops at the first instruction of a source
+ line. This prevents multiple stops that could otherwise occur in
+ `switch' statements, `for' loops, etc.
+
+`set step-mode'
+`set step-mode on'
+ The `set step-mode on' command causes the `step' command to stop
+ at the first instruction of a function which contains no debug line
+ information rather than stepping over it.
+
+ This is useful in cases where you may be interested in inspecting
+ the machine instructions of a function which has no symbolic info
+ and do not want GDB to automatically skip over this function.
+
+`set step-mode off'
+ Causes the `step' command to step over any functions which
+ contains no debug information. This is the default.
+
+`show step-mode'
+ Show whether GDB will stop in or step over functions without
+ source line debug information.
+
+`finish'
+ Continue running until just after function in the selected stack
+ frame returns. Print the returned value (if any). This command
+ can be abbreviated as `fin'.
+
+ Contrast this with the `return' command (*note Returning from a
+ Function: Returning.).
+
+`until'
+`u'
+ Continue running until a source line past the current line, in the
+ current stack frame, is reached. This command is used to avoid
+ single stepping through a loop more than once. It is like the
+ `next' command, except that when `until' encounters a jump, it
+ automatically continues execution until the program counter is
+ greater than the address of the jump.
+
+ This means that when you reach the end of a loop after single
+ stepping though it, `until' makes your program continue execution
+ until it exits the loop. In contrast, a `next' command at the end
+ of a loop simply steps back to the beginning of the loop, which
+ forces you to step through the next iteration.
+
+ `until' always stops your program if it attempts to exit the
+ current stack frame.
+
+ `until' may produce somewhat counterintuitive results if the order
+ of machine code does not match the order of the source lines. For
+ example, in the following excerpt from a debugging session, the `f'
+ (`frame') command shows that execution is stopped at line `206';
+ yet when we use `until', we get to line `195':
+
+ (gdb) f
+ #0 main (argc=4, argv=0xf7fffae8) at m4.c:206
+ 206 expand_input();
+ (gdb) until
+ 195 for ( ; argc > 0; NEXTARG) {
+
+ This happened because, for execution efficiency, the compiler had
+ generated code for the loop closure test at the end, rather than
+ the start, of the loop--even though the test in a C `for'-loop is
+ written before the body of the loop. The `until' command appeared
+ to step back to the beginning of the loop when it advanced to this
+ expression; however, it has not really gone to an earlier
+ statement--not in terms of the actual machine code.
+
+ `until' with no argument works by means of single instruction
+ stepping, and hence is slower than `until' with an argument.
+
+`until LOCATION'
+`u LOCATION'
+ Continue running your program until either the specified location
+ is reached, or the current stack frame returns. LOCATION is any of
+ the forms described in *Note Specify Location::. This form of the
+ command uses temporary breakpoints, and hence is quicker than
+ `until' without an argument. The specified location is actually
+ reached only if it is in the current frame. This implies that
+ `until' can be used to skip over recursive function invocations.
+ For instance in the code below, if the current location is line
+ `96', issuing `until 99' will execute the program up to line `99'
+ in the same invocation of factorial, i.e., after the inner
+ invocations have returned.
+
+ 94 int factorial (int value)
+ 95 {
+ 96 if (value > 1) {
+ 97 value *= factorial (value - 1);
+ 98 }
+ 99 return (value);
+ 100 }
+
+`advance LOCATION'
+ Continue running the program up to the given LOCATION. An
+ argument is required, which should be of one of the forms
+ described in *Note Specify Location::. Execution will also stop
+ upon exit from the current stack frame. This command is similar
+ to `until', but `advance' will not skip over recursive function
+ calls, and the target location doesn't have to be in the same
+ frame as the current one.
+
+`stepi'
+`stepi ARG'
+`si'
+ Execute one machine instruction, then stop and return to the
+ debugger.
+
+ It is often useful to do `display/i $pc' when stepping by machine
+ instructions. This makes GDB automatically display the next
+ instruction to be executed, each time your program stops. *Note
+ Automatic Display: Auto Display.
+
+ An argument is a repeat count, as in `step'.
+
+`nexti'
+`nexti ARG'
+`ni'
+ Execute one machine instruction, but if it is a function call,
+ proceed until the function returns.
+
+ An argument is a repeat count, as in `next'.
+
+
+File: gdb.info, Node: Skipping Over Functions and Files, Next: Signals, Prev: Continuing and Stepping, Up: Stopping
+
+5.3 Skipping Over Functions and Files
+=====================================
+
+The program you are debugging may contain some functions which are
+uninteresting to debug. The `skip' comand lets you tell GDB to skip a
+function or all functions in a file when stepping.
+
+ For example, consider the following C function:
+
+ 101 int func()
+ 102 {
+ 103 foo(boring());
+ 104 bar(boring());
+ 105 }
+
+Suppose you wish to step into the functions `foo' and `bar', but you
+are not interested in stepping through `boring'. If you run `step' at
+line 103, you'll enter `boring()', but if you run `next', you'll step
+over both `foo' and `boring'!
+
+ One solution is to `step' into `boring' and use the `finish' command
+to immediately exit it. But this can become tedious if `boring' is
+called from many places.
+
+ A more flexible solution is to execute `skip boring'. This instructs
+GDB never to step into `boring'. Now when you execute `step' at line
+103, you'll step over `boring' and directly into `foo'.
+
+ You can also instruct GDB to skip all functions in a file, with, for
+example, `skip file boring.c'.
+
+`skip [LINESPEC]'
+`skip function [LINESPEC]'
+ After running this command, the function named by LINESPEC or the
+ function containing the line named by LINESPEC will be skipped
+ over when stepping. *Note Specify Location::.
+
+ If you do not specify LINESPEC, the function you're currently
+ debugging will be skipped.
+
+ (If you have a function called `file' that you want to skip, use
+ `skip function file'.)
+
+`skip file [FILENAME]'
+ After running this command, any function whose source lives in
+ FILENAME will be skipped over when stepping.
+
+ If you do not specify FILENAME, functions whose source lives in
+ the file you're currently debugging will be skipped.
+
+ Skips can be listed, deleted, disabled, and enabled, much like
+breakpoints. These are the commands for managing your list of skips:
+
+`info skip [RANGE]'
+ Print details about the specified skip(s). If RANGE is not
+ specified, print a table with details about all functions and
+ files marked for skipping. `info skip' prints the following
+ information about each skip:
+
+ _Identifier_
+ A number identifying this skip.
+
+ _Type_
+ The type of this skip, either `function' or `file'.
+
+ _Enabled or Disabled_
+ Enabled skips are marked with `y'. Disabled skips are marked
+ with `n'.
+
+ _Address_
+ For function skips, this column indicates the address in
+ memory of the function being skipped. If you've set a
+ function skip on a function which has not yet been loaded,
+ this field will contain `<PENDING>'. Once a shared library
+ which has the function is loaded, `info skip' will show the
+ function's address here.
+
+ _What_
+ For file skips, this field contains the filename being
+ skipped. For functions skips, this field contains the
+ function name and its line number in the file where it is
+ defined.
+
+`skip delete [RANGE]'
+ Delete the specified skip(s). If RANGE is not specified, delete
+ all skips.
+
+`skip enable [RANGE]'
+ Enable the specified skip(s). If RANGE is not specified, enable
+ all skips.
+
+`skip disable [RANGE]'
+ Disable the specified skip(s). If RANGE is not specified, disable
+ all skips.
+
+
+
+File: gdb.info, Node: Signals, Next: Thread Stops, Prev: Skipping Over Functions and Files, Up: Stopping
+
+5.4 Signals
+===========
+
+A signal is an asynchronous event that can happen in a program. The
+operating system defines the possible kinds of signals, and gives each
+kind a name and a number. For example, in Unix `SIGINT' is the signal
+a program gets when you type an interrupt character (often `Ctrl-c');
+`SIGSEGV' is the signal a program gets from referencing a place in
+memory far away from all the areas in use; `SIGALRM' occurs when the
+alarm clock timer goes off (which happens only if your program has
+requested an alarm).
+
+ Some signals, including `SIGALRM', are a normal part of the
+functioning of your program. Others, such as `SIGSEGV', indicate
+errors; these signals are "fatal" (they kill your program immediately)
+if the program has not specified in advance some other way to handle
+the signal. `SIGINT' does not indicate an error in your program, but
+it is normally fatal so it can carry out the purpose of the interrupt:
+to kill the program.
+
+ GDB has the ability to detect any occurrence of a signal in your
+program. You can tell GDB in advance what to do for each kind of
+signal.
+
+ Normally, GDB is set up to let the non-erroneous signals like
+`SIGALRM' be silently passed to your program (so as not to interfere
+with their role in the program's functioning) but to stop your program
+immediately whenever an error signal happens. You can change these
+settings with the `handle' command.
+
+`info signals'
+`info handle'
+ Print a table of all the kinds of signals and how GDB has been
+ told to handle each one. You can use this to see the signal
+ numbers of all the defined types of signals.
+
+`info signals SIG'
+ Similar, but print information only about the specified signal
+ number.
+
+ `info handle' is an alias for `info signals'.
+
+`handle SIGNAL [KEYWORDS...]'
+ Change the way GDB handles signal SIGNAL. SIGNAL can be the
+ number of a signal or its name (with or without the `SIG' at the
+ beginning); a list of signal numbers of the form `LOW-HIGH'; or
+ the word `all', meaning all the known signals. Optional arguments
+ KEYWORDS, described below, say what change to make.
+
+ The keywords allowed by the `handle' command can be abbreviated.
+Their full names are:
+
+`nostop'
+ GDB should not stop your program when this signal happens. It may
+ still print a message telling you that the signal has come in.
+
+`stop'
+ GDB should stop your program when this signal happens. This
+ implies the `print' keyword as well.
+
+`print'
+ GDB should print a message when this signal happens.
+
+`noprint'
+ GDB should not mention the occurrence of the signal at all. This
+ implies the `nostop' keyword as well.
+
+`pass'
+`noignore'
+ GDB should allow your program to see this signal; your program can
+ handle the signal, or else it may terminate if the signal is fatal
+ and not handled. `pass' and `noignore' are synonyms.
+
+`nopass'
+`ignore'
+ GDB should not allow your program to see this signal. `nopass'
+ and `ignore' are synonyms.
+
+ When a signal stops your program, the signal is not visible to the
+program until you continue. Your program sees the signal then, if
+`pass' is in effect for the signal in question _at that time_. In
+other words, after GDB reports a signal, you can use the `handle'
+command with `pass' or `nopass' to control whether your program sees
+that signal when you continue.
+
+ The default is set to `nostop', `noprint', `pass' for non-erroneous
+signals such as `SIGALRM', `SIGWINCH' and `SIGCHLD', and to `stop',
+`print', `pass' for the erroneous signals.
+
+ You can also use the `signal' command to prevent your program from
+seeing a signal, or cause it to see a signal it normally would not see,
+or to give it any signal at any time. For example, if your program
+stopped due to some sort of memory reference error, you might store
+correct values into the erroneous variables and continue, hoping to see
+more execution; but your program would probably terminate immediately as
+a result of the fatal signal once it saw the signal. To prevent this,
+you can continue with `signal 0'. *Note Giving your Program a Signal:
+Signaling.
+
+ On some targets, GDB can inspect extra signal information associated
+with the intercepted signal, before it is actually delivered to the
+program being debugged. This information is exported by the
+convenience variable `$_siginfo', and consists of data that is passed
+by the kernel to the signal handler at the time of the receipt of a
+signal. The data type of the information itself is target dependent.
+You can see the data type using the `ptype $_siginfo' command. On Unix
+systems, it typically corresponds to the standard `siginfo_t' type, as
+defined in the `signal.h' system header.
+
+ Here's an example, on a GNU/Linux system, printing the stray
+referenced address that raised a segmentation fault.
+
+ (gdb) continue
+ Program received signal SIGSEGV, Segmentation fault.
+ 0x0000000000400766 in main ()
+ 69 *(int *)p = 0;
+ (gdb) ptype $_siginfo
+ type = struct {
+ int si_signo;
+ int si_errno;
+ int si_code;
+ union {
+ int _pad[28];
+ struct {...} _kill;
+ struct {...} _timer;
+ struct {...} _rt;
+ struct {...} _sigchld;
+ struct {...} _sigfault;
+ struct {...} _sigpoll;
+ } _sifields;
+ }
+ (gdb) ptype $_siginfo._sifields._sigfault
+ type = struct {
+ void *si_addr;
+ }
+ (gdb) p $_siginfo._sifields._sigfault.si_addr
+ $1 = (void *) 0x7ffff7ff7000
+
+ Depending on target support, `$_siginfo' may also be writable.
+
+
+File: gdb.info, Node: Thread Stops, Prev: Signals, Up: Stopping
+
+5.5 Stopping and Starting Multi-thread Programs
+===============================================
+
+GDB supports debugging programs with multiple threads (*note Debugging
+Programs with Multiple Threads: Threads.). There are two modes of
+controlling execution of your program within the debugger. In the
+default mode, referred to as "all-stop mode", when any thread in your
+program stops (for example, at a breakpoint or while being stepped),
+all other threads in the program are also stopped by GDB. On some
+targets, GDB also supports "non-stop mode", in which other threads can
+continue to run freely while you examine the stopped thread in the
+debugger.
+
+* Menu:
+
+* All-Stop Mode:: All threads stop when GDB takes control
+* Non-Stop Mode:: Other threads continue to execute
+* Background Execution:: Running your program asynchronously
+* Thread-Specific Breakpoints:: Controlling breakpoints
+* Interrupted System Calls:: GDB may interfere with system calls
+* Observer Mode:: GDB does not alter program behavior
+
+
+File: gdb.info, Node: All-Stop Mode, Next: Non-Stop Mode, Up: Thread Stops
+
+5.5.1 All-Stop Mode
+-------------------
+
+In all-stop mode, whenever your program stops under GDB for any reason,
+_all_ threads of execution stop, not just the current thread. This
+allows you to examine the overall state of the program, including
+switching between threads, without worrying that things may change
+underfoot.
+
+ Conversely, whenever you restart the program, _all_ threads start
+executing. _This is true even when single-stepping_ with commands like
+`step' or `next'.
+
+ In particular, GDB cannot single-step all threads in lockstep.
+Since thread scheduling is up to your debugging target's operating
+system (not controlled by GDB), other threads may execute more than one
+statement while the current thread completes a single step. Moreover,
+in general other threads stop in the middle of a statement, rather than
+at a clean statement boundary, when the program stops.
+
+ You might even find your program stopped in another thread after
+continuing or even single-stepping. This happens whenever some other
+thread runs into a breakpoint, a signal, or an exception before the
+first thread completes whatever you requested.
+
+ Whenever GDB stops your program, due to a breakpoint or a signal, it
+automatically selects the thread where that breakpoint or signal
+happened. GDB alerts you to the context switch with a message such as
+`[Switching to Thread N]' to identify the thread.
+
+ On some OSes, you can modify GDB's default behavior by locking the
+OS scheduler to allow only a single thread to run.
+
+`set scheduler-locking MODE'
+ Set the scheduler locking mode. If it is `off', then there is no
+ locking and any thread may run at any time. If `on', then only the
+ current thread may run when the inferior is resumed. The `step'
+ mode optimizes for single-stepping; it prevents other threads from
+ preempting the current thread while you are stepping, so that the
+ focus of debugging does not change unexpectedly. Other threads
+ only rarely (or never) get a chance to run when you step. They
+ are more likely to run when you `next' over a function call, and
+ they are completely free to run when you use commands like
+ `continue', `until', or `finish'. However, unless another thread
+ hits a breakpoint during its timeslice, GDB does not change the
+ current thread away from the thread that you are debugging.
+
+`show scheduler-locking'
+ Display the current scheduler locking mode.
+
+ By default, when you issue one of the execution commands such as
+`continue', `next' or `step', GDB allows only threads of the current
+inferior to run. For example, if GDB is attached to two inferiors,
+each with two threads, the `continue' command resumes only the two
+threads of the current inferior. This is useful, for example, when you
+debug a program that forks and you want to hold the parent stopped (so
+that, for instance, it doesn't run to exit), while you debug the child.
+In other situations, you may not be interested in inspecting the
+current state of any of the processes GDB is attached to, and you may
+want to resume them all until some breakpoint is hit. In the latter
+case, you can instruct GDB to allow all threads of all the inferiors to
+run with the `set schedule-multiple' command.
+
+`set schedule-multiple'
+ Set the mode for allowing threads of multiple processes to be
+ resumed when an execution command is issued. When `on', all
+ threads of all processes are allowed to run. When `off', only the
+ threads of the current process are resumed. The default is `off'.
+ The `scheduler-locking' mode takes precedence when set to `on',
+ or while you are stepping and set to `step'.
+
+`show schedule-multiple'
+ Display the current mode for resuming the execution of threads of
+ multiple processes.
+
+
+File: gdb.info, Node: Non-Stop Mode, Next: Background Execution, Prev: All-Stop Mode, Up: Thread Stops
+
+5.5.2 Non-Stop Mode
+-------------------
+
+For some multi-threaded targets, GDB supports an optional mode of
+operation in which you can examine stopped program threads in the
+debugger while other threads continue to execute freely. This
+minimizes intrusion when debugging live systems, such as programs where
+some threads have real-time constraints or must continue to respond to
+external events. This is referred to as "non-stop" mode.
+
+ In non-stop mode, when a thread stops to report a debugging event,
+_only_ that thread is stopped; GDB does not stop other threads as well,
+in contrast to the all-stop mode behavior. Additionally, execution
+commands such as `continue' and `step' apply by default only to the
+current thread in non-stop mode, rather than all threads as in all-stop
+mode. This allows you to control threads explicitly in ways that are
+not possible in all-stop mode -- for example, stepping one thread while
+allowing others to run freely, stepping one thread while holding all
+others stopped, or stepping several threads independently and
+simultaneously.
+
+ To enter non-stop mode, use this sequence of commands before you run
+or attach to your program:
+
+ # Enable the async interface.
+ set target-async 1
+
+ # If using the CLI, pagination breaks non-stop.
+ set pagination off
+
+ # Finally, turn it on!
+ set non-stop on
+
+ You can use these commands to manipulate the non-stop mode setting:
+
+`set non-stop on'
+ Enable selection of non-stop mode.
+
+`set non-stop off'
+ Disable selection of non-stop mode.
+
+`show non-stop'
+ Show the current non-stop enablement setting.
+
+ Note these commands only reflect whether non-stop mode is enabled,
+not whether the currently-executing program is being run in non-stop
+mode. In particular, the `set non-stop' preference is only consulted
+when GDB starts or connects to the target program, and it is generally
+not possible to switch modes once debugging has started. Furthermore,
+since not all targets support non-stop mode, even when you have enabled
+non-stop mode, GDB may still fall back to all-stop operation by default.
+
+ In non-stop mode, all execution commands apply only to the current
+thread by default. That is, `continue' only continues one thread. To
+continue all threads, issue `continue -a' or `c -a'.
+
+ You can use GDB's background execution commands (*note Background
+Execution::) to run some threads in the background while you continue
+to examine or step others from GDB. The MI execution commands (*note
+GDB/MI Program Execution::) are always executed asynchronously in
+non-stop mode.
+
+ Suspending execution is done with the `interrupt' command when
+running in the background, or `Ctrl-c' during foreground execution. In
+all-stop mode, this stops the whole process; but in non-stop mode the
+interrupt applies only to the current thread. To stop the whole
+program, use `interrupt -a'.
+
+ Other execution commands do not currently support the `-a' option.
+
+ In non-stop mode, when a thread stops, GDB doesn't automatically make
+that thread current, as it does in all-stop mode. This is because the
+thread stop notifications are asynchronous with respect to GDB's
+command interpreter, and it would be confusing if GDB unexpectedly
+changed to a different thread just as you entered a command to operate
+on the previously current thread.
+
+
+File: gdb.info, Node: Background Execution, Next: Thread-Specific Breakpoints, Prev: Non-Stop Mode, Up: Thread Stops
+
+5.5.3 Background Execution
+--------------------------
+
+GDB's execution commands have two variants: the normal foreground
+(synchronous) behavior, and a background (asynchronous) behavior. In
+foreground execution, GDB waits for the program to report that some
+thread has stopped before prompting for another command. In background
+execution, GDB immediately gives a command prompt so that you can issue
+other commands while your program runs.
+
+ You need to explicitly enable asynchronous mode before you can use
+background execution commands. You can use these commands to
+manipulate the asynchronous mode setting:
+
+`set target-async on'
+ Enable asynchronous mode.
+
+`set target-async off'
+ Disable asynchronous mode.
+
+`show target-async'
+ Show the current target-async setting.
+
+ If the target doesn't support async mode, GDB issues an error
+message if you attempt to use the background execution commands.
+
+ To specify background execution, add a `&' to the command. For
+example, the background form of the `continue' command is `continue&',
+or just `c&'. The execution commands that accept background execution
+are:
+
+`run'
+ *Note Starting your Program: Starting.
+
+`attach'
+ *Note Debugging an Already-running Process: Attach.
+
+`step'
+ *Note step: Continuing and Stepping.
+
+`stepi'
+ *Note stepi: Continuing and Stepping.
+
+`next'
+ *Note next: Continuing and Stepping.
+
+`nexti'
+ *Note nexti: Continuing and Stepping.
+
+`continue'
+ *Note continue: Continuing and Stepping.
+
+`finish'
+ *Note finish: Continuing and Stepping.
+
+`until'
+ *Note until: Continuing and Stepping.
+
+
+ Background execution is especially useful in conjunction with
+non-stop mode for debugging programs with multiple threads; see *Note
+Non-Stop Mode::. However, you can also use these commands in the
+normal all-stop mode with the restriction that you cannot issue another
+execution command until the previous one finishes. Examples of
+commands that are valid in all-stop mode while the program is running
+include `help' and `info break'.
+
+ You can interrupt your program while it is running in the background
+by using the `interrupt' command.
+
+`interrupt'
+`interrupt -a'
+ Suspend execution of the running program. In all-stop mode,
+ `interrupt' stops the whole process, but in non-stop mode, it stops
+ only the current thread. To stop the whole program in non-stop
+ mode, use `interrupt -a'.
+
+
+File: gdb.info, Node: Thread-Specific Breakpoints, Next: Interrupted System Calls, Prev: Background Execution, Up: Thread Stops
+
+5.5.4 Thread-Specific Breakpoints
+---------------------------------
+
+When your program has multiple threads (*note Debugging Programs with
+Multiple Threads: Threads.), you can choose whether to set breakpoints
+on all threads, or on a particular thread.
+
+`break LINESPEC thread THREADNO'
+`break LINESPEC thread THREADNO if ...'
+ LINESPEC specifies source lines; there are several ways of writing
+ them (*note Specify Location::), but the effect is always to
+ specify some source line.
+
+ Use the qualifier `thread THREADNO' with a breakpoint command to
+ specify that you only want GDB to stop the program when a
+ particular thread reaches this breakpoint. THREADNO is one of the
+ numeric thread identifiers assigned by GDB, shown in the first
+ column of the `info threads' display.
+
+ If you do not specify `thread THREADNO' when you set a breakpoint,
+ the breakpoint applies to _all_ threads of your program.
+
+ You can use the `thread' qualifier on conditional breakpoints as
+ well; in this case, place `thread THREADNO' before or after the
+ breakpoint condition, like this:
+
+ (gdb) break frik.c:13 thread 28 if bartab > lim
+
+
+
+File: gdb.info, Node: Interrupted System Calls, Next: Observer Mode, Prev: Thread-Specific Breakpoints, Up: Thread Stops
+
+5.5.5 Interrupted System Calls
+------------------------------
+
+There is an unfortunate side effect when using GDB to debug
+multi-threaded programs. If one thread stops for a breakpoint, or for
+some other reason, and another thread is blocked in a system call, then
+the system call may return prematurely. This is a consequence of the
+interaction between multiple threads and the signals that GDB uses to
+implement breakpoints and other events that stop execution.
+
+ To handle this problem, your program should check the return value of
+each system call and react appropriately. This is good programming
+style anyways.
+
+ For example, do not write code like this:
+
+ sleep (10);
+
+ The call to `sleep' will return early if a different thread stops at
+a breakpoint or for some other reason.
+
+ Instead, write this:
+
+ int unslept = 10;
+ while (unslept > 0)
+ unslept = sleep (unslept);
+
+ A system call is allowed to return early, so the system is still
+conforming to its specification. But GDB does cause your
+multi-threaded program to behave differently than it would without GDB.
+
+ Also, GDB uses internal breakpoints in the thread library to monitor
+certain events such as thread creation and thread destruction. When
+such an event happens, a system call in another thread may return
+prematurely, even though your program does not appear to stop.
+
+
+File: gdb.info, Node: Observer Mode, Prev: Interrupted System Calls, Up: Thread Stops
+
+5.5.6 Observer Mode
+-------------------
+
+If you want to build on non-stop mode and observe program behavior
+without any chance of disruption by GDB, you can set variables to
+disable all of the debugger's attempts to modify state, whether by
+writing memory, inserting breakpoints, etc. These operate at a low
+level, intercepting operations from all commands.
+
+ When all of these are set to `off', then GDB is said to be "observer
+mode". As a convenience, the variable `observer' can be set to disable
+these, plus enable non-stop mode.
+
+ Note that GDB will not prevent you from making nonsensical
+combinations of these settings. For instance, if you have enabled
+`may-insert-breakpoints' but disabled `may-write-memory', then
+breakpoints that work by writing trap instructions into the code stream
+will still not be able to be placed.
+
+`set observer on'
+`set observer off'
+ When set to `on', this disables all the permission variables below
+ (except for `insert-fast-tracepoints'), plus enables non-stop
+ debugging. Setting this to `off' switches back to normal
+ debugging, though remaining in non-stop mode.
+
+`show observer'
+ Show whether observer mode is on or off.
+
+`set may-write-registers on'
+`set may-write-registers off'
+ This controls whether GDB will attempt to alter the values of
+ registers, such as with assignment expressions in `print', or the
+ `jump' command. It defaults to `on'.
+
+`show may-write-registers'
+ Show the current permission to write registers.
+
+`set may-write-memory on'
+`set may-write-memory off'
+ This controls whether GDB will attempt to alter the contents of
+ memory, such as with assignment expressions in `print'. It
+ defaults to `on'.
+
+`show may-write-memory'
+ Show the current permission to write memory.
+
+`set may-insert-breakpoints on'
+`set may-insert-breakpoints off'
+ This controls whether GDB will attempt to insert breakpoints.
+ This affects all breakpoints, including internal breakpoints
+ defined by GDB. It defaults to `on'.
+
+`show may-insert-breakpoints'
+ Show the current permission to insert breakpoints.
+
+`set may-insert-tracepoints on'
+`set may-insert-tracepoints off'
+ This controls whether GDB will attempt to insert (regular)
+ tracepoints at the beginning of a tracing experiment. It affects
+ only non-fast tracepoints, fast tracepoints being under the
+ control of `may-insert-fast-tracepoints'. It defaults to `on'.
+
+`show may-insert-tracepoints'
+ Show the current permission to insert tracepoints.
+
+`set may-insert-fast-tracepoints on'
+`set may-insert-fast-tracepoints off'
+ This controls whether GDB will attempt to insert fast tracepoints
+ at the beginning of a tracing experiment. It affects only fast
+ tracepoints, regular (non-fast) tracepoints being under the
+ control of `may-insert-tracepoints'. It defaults to `on'.
+
+`show may-insert-fast-tracepoints'
+ Show the current permission to insert fast tracepoints.
+
+`set may-interrupt on'
+`set may-interrupt off'
+ This controls whether GDB will attempt to interrupt or stop
+ program execution. When this variable is `off', the `interrupt'
+ command will have no effect, nor will `Ctrl-c'. It defaults to
+ `on'.
+
+`show may-interrupt'
+ Show the current permission to interrupt or stop the program.
+
+
+
+File: gdb.info, Node: Reverse Execution, Next: Process Record and Replay, Prev: Stopping, Up: Top
+
+6 Running programs backward
+***************************
+
+When you are debugging a program, it is not unusual to realize that you
+have gone too far, and some event of interest has already happened. If
+the target environment supports it, GDB can allow you to "rewind" the
+program by running it backward.
+
+ A target environment that supports reverse execution should be able
+to "undo" the changes in machine state that have taken place as the
+program was executing normally. Variables, registers etc. should
+revert to their previous values. Obviously this requires a great deal
+of sophistication on the part of the target environment; not all target
+environments can support reverse execution.
+
+ When a program is executed in reverse, the instructions that have
+most recently been executed are "un-executed", in reverse order. The
+program counter runs backward, following the previous thread of
+execution in reverse. As each instruction is "un-executed", the values
+of memory and/or registers that were changed by that instruction are
+reverted to their previous states. After executing a piece of source
+code in reverse, all side effects of that code should be "undone", and
+all variables should be returned to their prior values(1).
+
+ If you are debugging in a target environment that supports reverse
+execution, GDB provides the following commands.
+
+`reverse-continue [IGNORE-COUNT]'
+`rc [IGNORE-COUNT]'
+ Beginning at the point where your program last stopped, start
+ executing in reverse. Reverse execution will stop for breakpoints
+ and synchronous exceptions (signals), just like normal execution.
+ Behavior of asynchronous signals depends on the target environment.
+
+`reverse-step [COUNT]'
+ Run the program backward until control reaches the start of a
+ different source line; then stop it, and return control to GDB.
+
+ Like the `step' command, `reverse-step' will only stop at the
+ beginning of a source line. It "un-executes" the previously
+ executed source line. If the previous source line included calls
+ to debuggable functions, `reverse-step' will step (backward) into
+ the called function, stopping at the beginning of the _last_
+ statement in the called function (typically a return statement).
+
+ Also, as with the `step' command, if non-debuggable functions are
+ called, `reverse-step' will run thru them backward without
+ stopping.
+
+`reverse-stepi [COUNT]'
+ Reverse-execute one machine instruction. Note that the instruction
+ to be reverse-executed is _not_ the one pointed to by the program
+ counter, but the instruction executed prior to that one. For
+ instance, if the last instruction was a jump, `reverse-stepi' will
+ take you back from the destination of the jump to the jump
+ instruction itself.
+
+`reverse-next [COUNT]'
+ Run backward to the beginning of the previous line executed in the
+ current (innermost) stack frame. If the line contains function
+ calls, they will be "un-executed" without stopping. Starting from
+ the first line of a function, `reverse-next' will take you back to
+ the caller of that function, _before_ the function was called,
+ just as the normal `next' command would take you from the last
+ line of a function back to its return to its caller (2).
+
+`reverse-nexti [COUNT]'
+ Like `nexti', `reverse-nexti' executes a single instruction in
+ reverse, except that called functions are "un-executed" atomically.
+ That is, if the previously executed instruction was a return from
+ another function, `reverse-nexti' will continue to execute in
+ reverse until the call to that function (from the current stack
+ frame) is reached.
+
+`reverse-finish'
+ Just as the `finish' command takes you to the point where the
+ current function returns, `reverse-finish' takes you to the point
+ where it was called. Instead of ending up at the end of the
+ current function invocation, you end up at the beginning.
+
+`set exec-direction'
+ Set the direction of target execution.
+
+`set exec-direction reverse'
+ GDB will perform all execution commands in reverse, until the
+ exec-direction mode is changed to "forward". Affected commands
+ include `step, stepi, next, nexti, continue, and finish'. The
+ `return' command cannot be used in reverse mode.
+
+`set exec-direction forward'
+ GDB will perform all execution commands in the normal fashion.
+ This is the default.
+
+ ---------- Footnotes ----------
+
+ (1) Note that some side effects are easier to undo than others. For
+instance, memory and registers are relatively easy, but device I/O is
+hard. Some targets may be able undo things like device I/O, and some
+may not.
+
+ The contract between GDB and the reverse executing target requires
+only that the target do something reasonable when GDB tells it to
+execute backwards, and then report the results back to GDB. Whatever
+the target reports back to GDB, GDB will report back to the user. GDB
+assumes that the memory and registers that the target reports are in a
+consistant state, but GDB accepts whatever it is given.
+
+ (2) Unless the code is too heavily optimized.
+
+
+File: gdb.info, Node: Process Record and Replay, Next: Stack, Prev: Reverse Execution, Up: Top
+
+7 Recording Inferior's Execution and Replaying It
+*************************************************
+
+On some platforms, GDB provides a special "process record and replay"
+target that can record a log of the process execution, and replay it
+later with both forward and reverse execution commands.
+
+ When this target is in use, if the execution log includes the record
+for the next instruction, GDB will debug in "replay mode". In the
+replay mode, the inferior does not really execute code instructions.
+Instead, all the events that normally happen during code execution are
+taken from the execution log. While code is not really executed in
+replay mode, the values of registers (including the program counter
+register) and the memory of the inferior are still changed as they
+normally would. Their contents are taken from the execution log.
+
+ If the record for the next instruction is not in the execution log,
+GDB will debug in "record mode". In this mode, the inferior executes
+normally, and GDB records the execution log for future replay.
+
+ The process record and replay target supports reverse execution
+(*note Reverse Execution::), even if the platform on which the inferior
+runs does not. However, the reverse execution is limited in this case
+by the range of the instructions recorded in the execution log. In
+other words, reverse execution on platforms that don't support it
+directly can only be done in the replay mode.
+
+ When debugging in the reverse direction, GDB will work in replay
+mode as long as the execution log includes the record for the previous
+instruction; otherwise, it will work in record mode, if the platform
+supports reverse execution, or stop if not.
+
+ For architecture environments that support process record and replay,
+GDB provides the following commands:
+
+`target record'
+ This command starts the process record and replay target. The
+ process record and replay target can only debug a process that is
+ already running. Therefore, you need first to start the process
+ with the `run' or `start' commands, and then start the recording
+ with the `target record' command.
+
+ Both `record' and `rec' are aliases of `target record'.
+
+ Displaced stepping (*note displaced stepping: Maintenance
+ Commands.) will be automatically disabled when process record and
+ replay target is started. That's because the process record and
+ replay target doesn't support displaced stepping.
+
+ If the inferior is in the non-stop mode (*note Non-Stop Mode::) or
+ in the asynchronous execution mode (*note Background Execution::),
+ the process record and replay target cannot be started because it
+ doesn't support these two modes.
+
+`record stop'
+ Stop the process record and replay target. When process record and
+ replay target stops, the entire execution log will be deleted and
+ the inferior will either be terminated, or will remain in its
+ final state.
+
+ When you stop the process record and replay target in record mode
+ (at the end of the execution log), the inferior will be stopped at
+ the next instruction that would have been recorded. In other
+ words, if you record for a while and then stop recording, the
+ inferior process will be left in the same state as if the
+ recording never happened.
+
+ On the other hand, if the process record and replay target is
+ stopped while in replay mode (that is, not at the end of the
+ execution log, but at some earlier point), the inferior process
+ will become "live" at that earlier state, and it will then be
+ possible to continue the usual "live" debugging of the process
+ from that state.
+
+ When the inferior process exits, or GDB detaches from it, process
+ record and replay target will automatically stop itself.
+
+`record save FILENAME'
+ Save the execution log to a file `FILENAME'. Default filename is
+ `gdb_record.PROCESS_ID', where PROCESS_ID is the process ID of the
+ inferior.
+
+`record restore FILENAME'
+ Restore the execution log from a file `FILENAME'. File must have
+ been created with `record save'.
+
+`set record insn-number-max LIMIT'
+ Set the limit of instructions to be recorded. Default value is
+ 200000.
+
+ If LIMIT is a positive number, then GDB will start deleting
+ instructions from the log once the number of the record
+ instructions becomes greater than LIMIT. For every new recorded
+ instruction, GDB will delete the earliest recorded instruction to
+ keep the number of recorded instructions at the limit. (Since
+ deleting recorded instructions loses information, GDB lets you
+ control what happens when the limit is reached, by means of the
+ `stop-at-limit' option, described below.)
+
+ If LIMIT is zero, GDB will never delete recorded instructions from
+ the execution log. The number of recorded instructions is
+ unlimited in this case.
+
+`show record insn-number-max'
+ Show the limit of instructions to be recorded.
+
+`set record stop-at-limit'
+ Control the behavior when the number of recorded instructions
+ reaches the limit. If ON (the default), GDB will stop when the
+ limit is reached for the first time and ask you whether you want
+ to stop the inferior or continue running it and recording the
+ execution log. If you decide to continue recording, each new
+ recorded instruction will cause the oldest one to be deleted.
+
+ If this option is OFF, GDB will automatically delete the oldest
+ record to make room for each new one, without asking.
+
+`show record stop-at-limit'
+ Show the current setting of `stop-at-limit'.
+
+`set record memory-query'
+ Control the behavior when GDB is unable to record memory changes
+ caused by an instruction. If ON, GDB will query whether to stop
+ the inferior in that case.
+
+ If this option is OFF (the default), GDB will automatically ignore
+ the effect of such instructions on memory. Later, when GDB
+ replays this execution log, it will mark the log of this
+ instruction as not accessible, and it will not affect the replay
+ results.
+
+`show record memory-query'
+ Show the current setting of `memory-query'.
+
+`info record'
+ Show various statistics about the state of process record and its
+ in-memory execution log buffer, including:
+
+ * Whether in record mode or replay mode.
+
+ * Lowest recorded instruction number (counting from when the
+ current execution log started recording instructions).
+
+ * Highest recorded instruction number.
+
+ * Current instruction about to be replayed (if in replay mode).
+
+ * Number of instructions contained in the execution log.
+
+ * Maximum number of instructions that may be contained in the
+ execution log.
+
+`record delete'
+ When record target runs in replay mode ("in the past"), delete the
+ subsequent execution log and begin to record a new execution log
+ starting from the current address. This means you will abandon
+ the previously recorded "future" and begin recording a new
+ "future".
+
+
+File: gdb.info, Node: Stack, Next: Source, Prev: Process Record and Replay, Up: Top
+
+8 Examining the Stack
+*********************
+
+When your program has stopped, the first thing you need to know is
+where it stopped and how it got there.
+
+ Each time your program performs a function call, information about
+the call is generated. That information includes the location of the
+call in your program, the arguments of the call, and the local
+variables of the function being called. The information is saved in a
+block of data called a "stack frame". The stack frames are allocated
+in a region of memory called the "call stack".
+
+ When your program stops, the GDB commands for examining the stack
+allow you to see all of this information.
+
+ One of the stack frames is "selected" by GDB and many GDB commands
+refer implicitly to the selected frame. In particular, whenever you
+ask GDB for the value of a variable in your program, the value is found
+in the selected frame. There are special GDB commands to select
+whichever frame you are interested in. *Note Selecting a Frame:
+Selection.
+
+ When your program stops, GDB automatically selects the currently
+executing frame and describes it briefly, similar to the `frame'
+command (*note Information about a Frame: Frame Info.).
+
+* Menu:
+
+* Frames:: Stack frames
+* Backtrace:: Backtraces
+* Selection:: Selecting a frame
+* Frame Info:: Information on a frame
+
+
+File: gdb.info, Node: Frames, Next: Backtrace, Up: Stack
+
+8.1 Stack Frames
+================
+
+The call stack is divided up into contiguous pieces called "stack
+frames", or "frames" for short; each frame is the data associated with
+one call to one function. The frame contains the arguments given to
+the function, the function's local variables, and the address at which
+the function is executing.
+
+ When your program is started, the stack has only one frame, that of
+the function `main'. This is called the "initial" frame or the
+"outermost" frame. Each time a function is called, a new frame is
+made. Each time a function returns, the frame for that function
+invocation is eliminated. If a function is recursive, there can be
+many frames for the same function. The frame for the function in which
+execution is actually occurring is called the "innermost" frame. This
+is the most recently created of all the stack frames that still exist.
+
+ Inside your program, stack frames are identified by their addresses.
+A stack frame consists of many bytes, each of which has its own
+address; each kind of computer has a convention for choosing one byte
+whose address serves as the address of the frame. Usually this address
+is kept in a register called the "frame pointer register" (*note $fp:
+Registers.) while execution is going on in that frame.
+
+ GDB assigns numbers to all existing stack frames, starting with zero
+for the innermost frame, one for the frame that called it, and so on
+upward. These numbers do not really exist in your program; they are
+assigned by GDB to give you a way of designating stack frames in GDB
+commands.
+
+ Some compilers provide a way to compile functions so that they
+operate without stack frames. (For example, the GCC option
+ `-fomit-frame-pointer'
+ generates functions without a frame.) This is occasionally done
+with heavily used library functions to save the frame setup time. GDB
+has limited facilities for dealing with these function invocations. If
+the innermost function invocation has no stack frame, GDB nevertheless
+regards it as though it had a separate frame, which is numbered zero as
+usual, allowing correct tracing of the function call chain. However,
+GDB has no provision for frameless functions elsewhere in the stack.
+
+`frame ARGS'
+ The `frame' command allows you to move from one stack frame to
+ another, and to print the stack frame you select. ARGS may be
+ either the address of the frame or the stack frame number.
+ Without an argument, `frame' prints the current stack frame.
+
+`select-frame'
+ The `select-frame' command allows you to move from one stack frame
+ to another without printing the frame. This is the silent version
+ of `frame'.
+
+
+File: gdb.info, Node: Backtrace, Next: Selection, Prev: Frames, Up: Stack
+
+8.2 Backtraces
+==============
+
+A backtrace is a summary of how your program got where it is. It shows
+one line per frame, for many frames, starting with the currently
+executing frame (frame zero), followed by its caller (frame one), and
+on up the stack.
+
+`backtrace'
+`bt'
+ Print a backtrace of the entire stack: one line per frame for all
+ frames in the stack.
+
+ You can stop the backtrace at any time by typing the system
+ interrupt character, normally `Ctrl-c'.
+
+`backtrace N'
+`bt N'
+ Similar, but print only the innermost N frames.
+
+`backtrace -N'
+`bt -N'
+ Similar, but print only the outermost N frames.
+
+`backtrace full'
+`bt full'
+`bt full N'
+`bt full -N'
+ Print the values of the local variables also. N specifies the
+ number of frames to print, as described above.
+
+ The names `where' and `info stack' (abbreviated `info s') are
+additional aliases for `backtrace'.
+
+ In a multi-threaded program, GDB by default shows the backtrace only
+for the current thread. To display the backtrace for several or all of
+the threads, use the command `thread apply' (*note thread apply:
+Threads.). For example, if you type `thread apply all backtrace', GDB
+will display the backtrace for all the threads; this is handy when you
+debug a core dump of a multi-threaded program.
+
+ Each line in the backtrace shows the frame number and the function
+name. The program counter value is also shown--unless you use `set
+print address off'. The backtrace also shows the source file name and
+line number, as well as the arguments to the function. The program
+counter value is omitted if it is at the beginning of the code for that
+line number.
+
+ Here is an example of a backtrace. It was made with the command `bt
+3', so it shows the innermost three frames.
+
+ #0 m4_traceon (obs=0x24eb0, argc=1, argv=0x2b8c8)
+ at builtin.c:993
+ #1 0x6e38 in expand_macro (sym=0x2b600, data=...) at macro.c:242
+ #2 0x6840 in expand_token (obs=0x0, t=177664, td=0xf7fffb08)
+ at macro.c:71
+ (More stack frames follow...)
+
+The display for frame zero does not begin with a program counter value,
+indicating that your program has stopped at the beginning of the code
+for line `993' of `builtin.c'.
+
+The value of parameter `data' in frame 1 has been replaced by `...'.
+By default, GDB prints the value of a parameter only if it is a scalar
+(integer, pointer, enumeration, etc). See command `set print
+frame-arguments' in *Note Print Settings:: for more details on how to
+configure the way function parameter values are printed.
+
+ If your program was compiled with optimizations, some compilers will
+optimize away arguments passed to functions if those arguments are
+never used after the call. Such optimizations generate code that
+passes arguments through registers, but doesn't store those arguments
+in the stack frame. GDB has no way of displaying such arguments in
+stack frames other than the innermost one. Here's what such a
+backtrace might look like:
+
+ #0 m4_traceon (obs=0x24eb0, argc=1, argv=0x2b8c8)
+ at builtin.c:993
+ #1 0x6e38 in expand_macro (sym=<optimized out>) at macro.c:242
+ #2 0x6840 in expand_token (obs=0x0, t=<optimized out>, td=0xf7fffb08)
+ at macro.c:71
+ (More stack frames follow...)
+
+The values of arguments that were not saved in their stack frames are
+shown as `<optimized out>'.
+
+ If you need to display the values of such optimized-out arguments,
+either deduce that from other variables whose values depend on the one
+you are interested in, or recompile without optimizations.
+
+ Most programs have a standard user entry point--a place where system
+libraries and startup code transition into user code. For C this is
+`main'(1). When GDB finds the entry function in a backtrace it will
+terminate the backtrace, to avoid tracing into highly system-specific
+(and generally uninteresting) code.
+
+ If you need to examine the startup code, or limit the number of
+levels in a backtrace, you can change this behavior:
+
+`set backtrace past-main'
+`set backtrace past-main on'
+ Backtraces will continue past the user entry point.
+
+`set backtrace past-main off'
+ Backtraces will stop when they encounter the user entry point.
+ This is the default.
+
+`show backtrace past-main'
+ Display the current user entry point backtrace policy.
+
+`set backtrace past-entry'
+`set backtrace past-entry on'
+ Backtraces will continue past the internal entry point of an
+ application. This entry point is encoded by the linker when the
+ application is built, and is likely before the user entry point
+ `main' (or equivalent) is called.
+
+`set backtrace past-entry off'
+ Backtraces will stop when they encounter the internal entry point
+ of an application. This is the default.
+
+`show backtrace past-entry'
+ Display the current internal entry point backtrace policy.
+
+`set backtrace limit N'
+`set backtrace limit 0'
+ Limit the backtrace to N levels. A value of zero means unlimited.
+
+`show backtrace limit'
+ Display the current limit on backtrace levels.
+
+ ---------- Footnotes ----------
+
+ (1) Note that embedded programs (the so-called "free-standing"
+environment) are not required to have a `main' function as the entry
+point. They could even have multiple entry points.
+
+
+File: gdb.info, Node: Selection, Next: Frame Info, Prev: Backtrace, Up: Stack
+
+8.3 Selecting a Frame
+=====================
+
+Most commands for examining the stack and other data in your program
+work on whichever stack frame is selected at the moment. Here are the
+commands for selecting a stack frame; all of them finish by printing a
+brief description of the stack frame just selected.
+
+`frame N'
+`f N'
+ Select frame number N. Recall that frame zero is the innermost
+ (currently executing) frame, frame one is the frame that called the
+ innermost one, and so on. The highest-numbered frame is the one
+ for `main'.
+
+`frame ADDR'
+`f ADDR'
+ Select the frame at address ADDR. This is useful mainly if the
+ chaining of stack frames has been damaged by a bug, making it
+ impossible for GDB to assign numbers properly to all frames. In
+ addition, this can be useful when your program has multiple stacks
+ and switches between them.
+
+ On the SPARC architecture, `frame' needs two addresses to select
+ an arbitrary frame: a frame pointer and a stack pointer.
+
+ On the MIPS and Alpha architecture, it needs two addresses: a stack
+ pointer and a program counter.
+
+ On the 29k architecture, it needs three addresses: a register stack
+ pointer, a program counter, and a memory stack pointer.
+
+`up N'
+ Move N frames up the stack. For positive numbers N, this advances
+ toward the outermost frame, to higher frame numbers, to frames
+ that have existed longer. N defaults to one.
+
+`down N'
+ Move N frames down the stack. For positive numbers N, this
+ advances toward the innermost frame, to lower frame numbers, to
+ frames that were created more recently. N defaults to one. You
+ may abbreviate `down' as `do'.
+
+ All of these commands end by printing two lines of output describing
+the frame. The first line shows the frame number, the function name,
+the arguments, and the source file and line number of execution in that
+frame. The second line shows the text of that source line.
+
+ For example:
+
+ (gdb) up
+ #1 0x22f0 in main (argc=1, argv=0xf7fffbf4, env=0xf7fffbfc)
+ at env.c:10
+ 10 read_input_file (argv[i]);
+
+ After such a printout, the `list' command with no arguments prints
+ten lines centered on the point of execution in the frame. You can
+also edit the program at the point of execution with your favorite
+editing program by typing `edit'. *Note Printing Source Lines: List,
+for details.
+
+`up-silently N'
+`down-silently N'
+ These two commands are variants of `up' and `down', respectively;
+ they differ in that they do their work silently, without causing
+ display of the new frame. They are intended primarily for use in
+ GDB command scripts, where the output might be unnecessary and
+ distracting.
+
+
+File: gdb.info, Node: Frame Info, Prev: Selection, Up: Stack
+
+8.4 Information About a Frame
+=============================
+
+There are several other commands to print information about the selected
+stack frame.
+
+`frame'
+`f'
+ When used without any argument, this command does not change which
+ frame is selected, but prints a brief description of the currently
+ selected stack frame. It can be abbreviated `f'. With an
+ argument, this command is used to select a stack frame. *Note
+ Selecting a Frame: Selection.
+
+`info frame'
+`info f'
+ This command prints a verbose description of the selected stack
+ frame, including:
+
+ * the address of the frame
+
+ * the address of the next frame down (called by this frame)
+
+ * the address of the next frame up (caller of this frame)
+
+ * the language in which the source code corresponding to this
+ frame is written
+
+ * the address of the frame's arguments
+
+ * the address of the frame's local variables
+
+ * the program counter saved in it (the address of execution in
+ the caller frame)
+
+ * which registers were saved in the frame
+
+ The verbose description is useful when something has gone wrong
+ that has made the stack format fail to fit the usual conventions.
+
+`info frame ADDR'
+`info f ADDR'
+ Print a verbose description of the frame at address ADDR, without
+ selecting that frame. The selected frame remains unchanged by this
+ command. This requires the same kind of address (more than one
+ for some architectures) that you specify in the `frame' command.
+ *Note Selecting a Frame: Selection.
+
+`info args'
+ Print the arguments of the selected frame, each on a separate line.
+
+`info locals'
+ Print the local variables of the selected frame, each on a separate
+ line. These are all variables (declared either static or
+ automatic) accessible at the point of execution of the selected
+ frame.
+
+`info catch'
+ Print a list of all the exception handlers that are active in the
+ current stack frame at the current point of execution. To see
+ other exception handlers, visit the associated frame (using the
+ `up', `down', or `frame' commands); then type `info catch'. *Note
+ Setting Catchpoints: Set Catchpoints.
+
+
+
+File: gdb.info, Node: Source, Next: Data, Prev: Stack, Up: Top
+
+9 Examining Source Files
+************************
+
+GDB can print parts of your program's source, since the debugging
+information recorded in the program tells GDB what source files were
+used to build it. When your program stops, GDB spontaneously prints
+the line where it stopped. Likewise, when you select a stack frame
+(*note Selecting a Frame: Selection.), GDB prints the line where
+execution in that frame has stopped. You can print other portions of
+source files by explicit command.
+
+ If you use GDB through its GNU Emacs interface, you may prefer to
+use Emacs facilities to view source; see *Note Using GDB under GNU
+Emacs: Emacs.
+
+* Menu:
+
+* List:: Printing source lines
+* Specify Location:: How to specify code locations
+* Edit:: Editing source files
+* Search:: Searching source files
+* Source Path:: Specifying source directories
+* Machine Code:: Source and machine code
+
+
+File: gdb.info, Node: List, Next: Specify Location, Up: Source
+
+9.1 Printing Source Lines
+=========================
+
+To print lines from a source file, use the `list' command (abbreviated
+`l'). By default, ten lines are printed. There are several ways to
+specify what part of the file you want to print; see *Note Specify
+Location::, for the full list.
+
+ Here are the forms of the `list' command most commonly used:
+
+`list LINENUM'
+ Print lines centered around line number LINENUM in the current
+ source file.
+
+`list FUNCTION'
+ Print lines centered around the beginning of function FUNCTION.
+
+`list'
+ Print more lines. If the last lines printed were printed with a
+ `list' command, this prints lines following the last lines
+ printed; however, if the last line printed was a solitary line
+ printed as part of displaying a stack frame (*note Examining the
+ Stack: Stack.), this prints lines centered around that line.
+
+`list -'
+ Print lines just before the lines last printed.
+
+ By default, GDB prints ten source lines with any of these forms of
+the `list' command. You can change this using `set listsize':
+
+`set listsize COUNT'
+ Make the `list' command display COUNT source lines (unless the
+ `list' argument explicitly specifies some other number).
+
+`show listsize'
+ Display the number of lines that `list' prints.
+
+ Repeating a `list' command with <RET> discards the argument, so it
+is equivalent to typing just `list'. This is more useful than listing
+the same lines again. An exception is made for an argument of `-';
+that argument is preserved in repetition so that each repetition moves
+up in the source file.
+
+ In general, the `list' command expects you to supply zero, one or two
+"linespecs". Linespecs specify source lines; there are several ways of
+writing them (*note Specify Location::), but the effect is always to
+specify some source line.
+
+ Here is a complete description of the possible arguments for `list':
+
+`list LINESPEC'
+ Print lines centered around the line specified by LINESPEC.
+
+`list FIRST,LAST'
+ Print lines from FIRST to LAST. Both arguments are linespecs.
+ When a `list' command has two linespecs, and the source file of
+ the second linespec is omitted, this refers to the same source
+ file as the first linespec.
+
+`list ,LAST'
+ Print lines ending with LAST.
+
+`list FIRST,'
+ Print lines starting with FIRST.
+
+`list +'
+ Print lines just after the lines last printed.
+
+`list -'
+ Print lines just before the lines last printed.
+
+`list'
+ As described in the preceding table.
+
+
+File: gdb.info, Node: Specify Location, Next: Edit, Prev: List, Up: Source
+
+9.2 Specifying a Location
+=========================
+
+Several GDB commands accept arguments that specify a location of your
+program's code. Since GDB is a source-level debugger, a location
+usually specifies some line in the source code; for that reason,
+locations are also known as "linespecs".
+
+ Here are all the different ways of specifying a code location that
+GDB understands:
+
+`LINENUM'
+ Specifies the line number LINENUM of the current source file.
+
+`-OFFSET'
+`+OFFSET'
+ Specifies the line OFFSET lines before or after the "current
+ line". For the `list' command, the current line is the last one
+ printed; for the breakpoint commands, this is the line at which
+ execution stopped in the currently selected "stack frame" (*note
+ Frames: Frames, for a description of stack frames.) When used as
+ the second of the two linespecs in a `list' command, this
+ specifies the line OFFSET lines up or down from the first linespec.
+
+`FILENAME:LINENUM'
+ Specifies the line LINENUM in the source file FILENAME.
+
+`FUNCTION'
+ Specifies the line that begins the body of the function FUNCTION.
+ For example, in C, this is the line with the open brace.
+
+`FUNCTION:LABEL'
+ Specifies the line where LABEL appears in FUNCTION.
+
+`FILENAME:FUNCTION'
+ Specifies the line that begins the body of the function FUNCTION
+ in the file FILENAME. You only need the file name with a function
+ name to avoid ambiguity when there are identically named functions
+ in different source files.
+
+`LABEL'
+ Specifies the line at which the label named LABEL appears. GDB
+ searches for the label in the function corresponding to the
+ currently selected stack frame. If there is no current selected
+ stack frame (for instance, if the inferior is not running), then
+ GDB will not search for a label.
+
+`*ADDRESS'
+ Specifies the program address ADDRESS. For line-oriented
+ commands, such as `list' and `edit', this specifies a source line
+ that contains ADDRESS. For `break' and other breakpoint oriented
+ commands, this can be used to set breakpoints in parts of your
+ program which do not have debugging information or source files.
+
+ Here ADDRESS may be any expression valid in the current working
+ language (*note working language: Languages.) that specifies a code
+ address. In addition, as a convenience, GDB extends the semantics
+ of expressions used in locations to cover the situations that
+ frequently happen during debugging. Here are the various forms of
+ ADDRESS:
+
+ `EXPRESSION'
+ Any expression valid in the current working language.
+
+ `FUNCADDR'
+ An address of a function or procedure derived from its name.
+ In C, C++, Java, Objective-C, Fortran, minimal, and assembly,
+ this is simply the function's name FUNCTION (and actually a
+ special case of a valid expression). In Pascal and Modula-2,
+ this is `&FUNCTION'. In Ada, this is `FUNCTION'Address'
+ (although the Pascal form also works).
+
+ This form specifies the address of the function's first
+ instruction, before the stack frame and arguments have been
+ set up.
+
+ `'FILENAME'::FUNCADDR'
+ Like FUNCADDR above, but also specifies the name of the source
+ file explicitly. This is useful if the name of the function
+ does not specify the function unambiguously, e.g., if there
+ are several functions with identical names in different
+ source files.
+
+
+
+File: gdb.info, Node: Edit, Next: Search, Prev: Specify Location, Up: Source
+
+9.3 Editing Source Files
+========================
+
+To edit the lines in a source file, use the `edit' command. The
+editing program of your choice is invoked with the current line set to
+the active line in the program. Alternatively, there are several ways
+to specify what part of the file you want to print if you want to see
+other parts of the program:
+
+`edit LOCATION'
+ Edit the source file specified by `location'. Editing starts at
+ that LOCATION, e.g., at the specified source line of the specified
+ file. *Note Specify Location::, for all the possible forms of the
+ LOCATION argument; here are the forms of the `edit' command most
+ commonly used:
+
+ `edit NUMBER'
+ Edit the current source file with NUMBER as the active line
+ number.
+
+ `edit FUNCTION'
+ Edit the file containing FUNCTION at the beginning of its
+ definition.
+
+
+9.3.1 Choosing your Editor
+--------------------------
+
+You can customize GDB to use any editor you want (1). By default, it
+is `/bin/ex', but you can change this by setting the environment
+variable `EDITOR' before using GDB. For example, to configure GDB to
+use the `vi' editor, you could use these commands with the `sh' shell:
+ EDITOR=/usr/bin/vi
+ export EDITOR
+ gdb ...
+ or in the `csh' shell,
+ setenv EDITOR /usr/bin/vi
+ gdb ...
+
+ ---------- Footnotes ----------
+
+ (1) The only restriction is that your editor (say `ex'), recognizes
+the following command-line syntax:
+ ex +NUMBER file
+ The optional numeric value +NUMBER specifies the number of the line
+in the file where to start editing.
+
+
+File: gdb.info, Node: Search, Next: Source Path, Prev: Edit, Up: Source
+
+9.4 Searching Source Files
+==========================
+
+There are two commands for searching through the current source file
+for a regular expression.
+
+`forward-search REGEXP'
+`search REGEXP'
+ The command `forward-search REGEXP' checks each line, starting
+ with the one following the last line listed, for a match for
+ REGEXP. It lists the line that is found. You can use the synonym
+ `search REGEXP' or abbreviate the command name as `fo'.
+
+`reverse-search REGEXP'
+ The command `reverse-search REGEXP' checks each line, starting
+ with the one before the last line listed and going backward, for a
+ match for REGEXP. It lists the line that is found. You can
+ abbreviate this command as `rev'.
+
+
+File: gdb.info, Node: Source Path, Next: Machine Code, Prev: Search, Up: Source
+
+9.5 Specifying Source Directories
+=================================
+
+Executable programs sometimes do not record the directories of the
+source files from which they were compiled, just the names. Even when
+they do, the directories could be moved between the compilation and
+your debugging session. GDB has a list of directories to search for
+source files; this is called the "source path". Each time GDB wants a
+source file, it tries all the directories in the list, in the order
+they are present in the list, until it finds a file with the desired
+name.
+
+ For example, suppose an executable references the file
+`/usr/src/foo-1.0/lib/foo.c', and our source path is `/mnt/cross'. The
+file is first looked up literally; if this fails,
+`/mnt/cross/usr/src/foo-1.0/lib/foo.c' is tried; if this fails,
+`/mnt/cross/foo.c' is opened; if this fails, an error message is
+printed. GDB does not look up the parts of the source file name, such
+as `/mnt/cross/src/foo-1.0/lib/foo.c'. Likewise, the subdirectories of
+the source path are not searched: if the source path is `/mnt/cross',
+and the binary refers to `foo.c', GDB would not find it under
+`/mnt/cross/usr/src/foo-1.0/lib'.
+
+ Plain file names, relative file names with leading directories, file
+names containing dots, etc. are all treated as described above; for
+instance, if the source path is `/mnt/cross', and the source file is
+recorded as `../lib/foo.c', GDB would first try `../lib/foo.c', then
+`/mnt/cross/../lib/foo.c', and after that--`/mnt/cross/foo.c'.
+
+ Note that the executable search path is _not_ used to locate the
+source files.
+
+ Whenever you reset or rearrange the source path, GDB clears out any
+information it has cached about where source files are found and where
+each line is in the file.
+
+ When you start GDB, its source path includes only `cdir' and `cwd',
+in that order. To add other directories, use the `directory' command.
+
+ The search path is used to find both program source files and GDB
+script files (read using the `-command' option and `source' command).
+
+ In addition to the source path, GDB provides a set of commands that
+manage a list of source path substitution rules. A "substitution rule"
+specifies how to rewrite source directories stored in the program's
+debug information in case the sources were moved to a different
+directory between compilation and debugging. A rule is made of two
+strings, the first specifying what needs to be rewritten in the path,
+and the second specifying how it should be rewritten. In *Note set
+substitute-path::, we name these two parts FROM and TO respectively.
+GDB does a simple string replacement of FROM with TO at the start of
+the directory part of the source file name, and uses that result
+instead of the original file name to look up the sources.
+
+ Using the previous example, suppose the `foo-1.0' tree has been
+moved from `/usr/src' to `/mnt/cross', then you can tell GDB to replace
+`/usr/src' in all source path names with `/mnt/cross'. The first
+lookup will then be `/mnt/cross/foo-1.0/lib/foo.c' in place of the
+original location of `/usr/src/foo-1.0/lib/foo.c'. To define a source
+path substitution rule, use the `set substitute-path' command (*note
+set substitute-path::).
+
+ To avoid unexpected substitution results, a rule is applied only if
+the FROM part of the directory name ends at a directory separator. For
+instance, a rule substituting `/usr/source' into `/mnt/cross' will be
+applied to `/usr/source/foo-1.0' but not to `/usr/sourceware/foo-2.0'.
+And because the substitution is applied only at the beginning of the
+directory name, this rule will not be applied to
+`/root/usr/source/baz.c' either.
+
+ In many cases, you can achieve the same result using the `directory'
+command. However, `set substitute-path' can be more efficient in the
+case where the sources are organized in a complex tree with multiple
+subdirectories. With the `directory' command, you need to add each
+subdirectory of your project. If you moved the entire tree while
+preserving its internal organization, then `set substitute-path' allows
+you to direct the debugger to all the sources with one single command.
+
+ `set substitute-path' is also more than just a shortcut command.
+The source path is only used if the file at the original location no
+longer exists. On the other hand, `set substitute-path' modifies the
+debugger behavior to look at the rewritten location instead. So, if
+for any reason a source file that is not relevant to your executable is
+located at the original location, a substitution rule is the only
+method available to point GDB at the new location.
+
+ You can configure a default source path substitution rule by
+configuring GDB with the `--with-relocated-sources=DIR' option. The DIR
+should be the name of a directory under GDB's configured prefix (set
+with `--prefix' or `--exec-prefix'), and directory names in debug
+information under DIR will be adjusted automatically if the installed
+GDB is moved to a new location. This is useful if GDB, libraries or
+executables with debug information and corresponding source code are
+being moved together.
+
+`directory DIRNAME ...'
+
+`dir DIRNAME ...'
+ Add directory DIRNAME to the front of the source path. Several
+ directory names may be given to this command, separated by `:'
+ (`;' on MS-DOS and MS-Windows, where `:' usually appears as part
+ of absolute file names) or whitespace. You may specify a
+ directory that is already in the source path; this moves it
+ forward, so GDB searches it sooner.
+
+ You can use the string `$cdir' to refer to the compilation
+ directory (if one is recorded), and `$cwd' to refer to the current
+ working directory. `$cwd' is not the same as `.'--the former
+ tracks the current working directory as it changes during your GDB
+ session, while the latter is immediately expanded to the current
+ directory at the time you add an entry to the source path.
+
+`directory'
+ Reset the source path to its default value (`$cdir:$cwd' on Unix
+ systems). This requires confirmation.
+
+`set directories PATH-LIST'
+ Set the source path to PATH-LIST. `$cdir:$cwd' are added if
+ missing.
+
+`show directories'
+ Print the source path: show which directories it contains.
+
+`set substitute-path FROM TO'
+ Define a source path substitution rule, and add it at the end of
+ the current list of existing substitution rules. If a rule with
+ the same FROM was already defined, then the old rule is also
+ deleted.
+
+ For example, if the file `/foo/bar/baz.c' was moved to
+ `/mnt/cross/baz.c', then the command
+
+ (gdb) set substitute-path /usr/src /mnt/cross
+
+ will tell GDB to replace `/usr/src' with `/mnt/cross', which will
+ allow GDB to find the file `baz.c' even though it was moved.
+
+ In the case when more than one substitution rule have been defined,
+ the rules are evaluated one by one in the order where they have
+ been defined. The first one matching, if any, is selected to
+ perform the substitution.
+
+ For instance, if we had entered the following commands:
+
+ (gdb) set substitute-path /usr/src/include /mnt/include
+ (gdb) set substitute-path /usr/src /mnt/src
+
+ GDB would then rewrite `/usr/src/include/defs.h' into
+ `/mnt/include/defs.h' by using the first rule. However, it would
+ use the second rule to rewrite `/usr/src/lib/foo.c' into
+ `/mnt/src/lib/foo.c'.
+
+`unset substitute-path [path]'
+ If a path is specified, search the current list of substitution
+ rules for a rule that would rewrite that path. Delete that rule
+ if found. A warning is emitted by the debugger if no rule could
+ be found.
+
+ If no path is specified, then all substitution rules are deleted.
+
+`show substitute-path [path]'
+ If a path is specified, then print the source path substitution
+ rule which would rewrite that path, if any.
+
+ If no path is specified, then print all existing source path
+ substitution rules.
+
+
+ If your source path is cluttered with directories that are no longer
+of interest, GDB may sometimes cause confusion by finding the wrong
+versions of source. You can correct the situation as follows:
+
+ 1. Use `directory' with no argument to reset the source path to its
+ default value.
+
+ 2. Use `directory' with suitable arguments to reinstall the
+ directories you want in the source path. You can add all the
+ directories in one command.
+
+
+File: gdb.info, Node: Machine Code, Prev: Source Path, Up: Source
+
+9.6 Source and Machine Code
+===========================
+
+You can use the command `info line' to map source lines to program
+addresses (and vice versa), and the command `disassemble' to display a
+range of addresses as machine instructions. You can use the command
+`set disassemble-next-line' to set whether to disassemble next source
+line when execution stops. When run under GNU Emacs mode, the `info
+line' command causes the arrow to point to the line specified. Also,
+`info line' prints addresses in symbolic form as well as hex.
+
+`info line LINESPEC'
+ Print the starting and ending addresses of the compiled code for
+ source line LINESPEC. You can specify source lines in any of the
+ ways documented in *Note Specify Location::.
+
+ For example, we can use `info line' to discover the location of the
+object code for the first line of function `m4_changequote':
+
+ (gdb) info line m4_changequote
+ Line 895 of "builtin.c" starts at pc 0x634c and ends at 0x6350.
+
+We can also inquire (using `*ADDR' as the form for LINESPEC) what
+source line covers a particular address:
+ (gdb) info line *0x63ff
+ Line 926 of "builtin.c" starts at pc 0x63e4 and ends at 0x6404.
+
+ After `info line', the default address for the `x' command is
+changed to the starting address of the line, so that `x/i' is
+sufficient to begin examining the machine code (*note Examining Memory:
+Memory.). Also, this address is saved as the value of the convenience
+variable `$_' (*note Convenience Variables: Convenience Vars.).
+
+`disassemble'
+`disassemble /m'
+`disassemble /r'
+ This specialized command dumps a range of memory as machine
+ instructions. It can also print mixed source+disassembly by
+ specifying the `/m' modifier and print the raw instructions in hex
+ as well as in symbolic form by specifying the `/r'. The default
+ memory range is the function surrounding the program counter of
+ the selected frame. A single argument to this command is a
+ program counter value; GDB dumps the function surrounding this
+ value. When two arguments are given, they should be separated by
+ a comma, possibly surrounded by whitespace. The arguments specify
+ a range of addresses to dump, in one of two forms:
+
+ `START,END'
+ the addresses from START (inclusive) to END (exclusive)
+
+ `START,+LENGTH'
+ the addresses from START (inclusive) to `START+LENGTH'
+ (exclusive).
+
+ When 2 arguments are specified, the name of the function is also
+ printed (since there could be several functions in the given
+ range).
+
+ The argument(s) can be any expression yielding a numeric value,
+ such as `0x32c4', `&main+10' or `$pc - 8'.
+
+ If the range of memory being disassembled contains current program
+ counter, the instruction at that location is shown with a `=>'
+ marker.
+
+ The following example shows the disassembly of a range of addresses
+of HP PA-RISC 2.0 code:
+
+ (gdb) disas 0x32c4, 0x32e4
+ Dump of assembler code from 0x32c4 to 0x32e4:
+ 0x32c4 <main+204>: addil 0,dp
+ 0x32c8 <main+208>: ldw 0x22c(sr0,r1),r26
+ 0x32cc <main+212>: ldil 0x3000,r31
+ 0x32d0 <main+216>: ble 0x3f8(sr4,r31)
+ 0x32d4 <main+220>: ldo 0(r31),rp
+ 0x32d8 <main+224>: addil -0x800,dp
+ 0x32dc <main+228>: ldo 0x588(r1),r26
+ 0x32e0 <main+232>: ldil 0x3000,r31
+ End of assembler dump.
+
+ Here is an example showing mixed source+assembly for Intel x86, when
+the program is stopped just after function prologue:
+
+ (gdb) disas /m main
+ Dump of assembler code for function main:
+ 5 {
+ 0x08048330 <+0>: push %ebp
+ 0x08048331 <+1>: mov %esp,%ebp
+ 0x08048333 <+3>: sub $0x8,%esp
+ 0x08048336 <+6>: and $0xfffffff0,%esp
+ 0x08048339 <+9>: sub $0x10,%esp
+
+ 6 printf ("Hello.\n");
+ => 0x0804833c <+12>: movl $0x8048440,(%esp)
+ 0x08048343 <+19>: call 0x8048284 <puts@plt>
+
+ 7 return 0;
+ 8 }
+ 0x08048348 <+24>: mov $0x0,%eax
+ 0x0804834d <+29>: leave
+ 0x0804834e <+30>: ret
+
+ End of assembler dump.
+
+ Here is another example showing raw instructions in hex for AMD
+x86-64,
+
+ (gdb) disas /r 0x400281,+10
+ Dump of assembler code from 0x400281 to 0x40028b:
+ 0x0000000000400281: 38 36 cmp %dh,(%rsi)
+ 0x0000000000400283: 2d 36 34 2e 73 sub $0x732e3436,%eax
+ 0x0000000000400288: 6f outsl %ds:(%rsi),(%dx)
+ 0x0000000000400289: 2e 32 00 xor %cs:(%rax),%al
+ End of assembler dump.
+
+ Some architectures have more than one commonly-used set of
+instruction mnemonics or other syntax.
+
+ For programs that were dynamically linked and use shared libraries,
+instructions that call functions or branch to locations in the shared
+libraries might show a seemingly bogus location--it's actually a
+location of the relocation table. On some architectures, GDB might be
+able to resolve these to actual function names.
+
+`set disassembly-flavor INSTRUCTION-SET'
+ Select the instruction set to use when disassembling the program
+ via the `disassemble' or `x/i' commands.
+
+ Currently this command is only defined for the Intel x86 family.
+ You can set INSTRUCTION-SET to either `intel' or `att'. The
+ default is `att', the AT&T flavor used by default by Unix
+ assemblers for x86-based targets.
+
+`show disassembly-flavor'
+ Show the current setting of the disassembly flavor.
+
+`set disassemble-next-line'
+`show disassemble-next-line'
+ Control whether or not GDB will disassemble the next source line
+ or instruction when execution stops. If ON, GDB will display
+ disassembly of the next source line when execution of the program
+ being debugged stops. This is _in addition_ to displaying the
+ source line itself, which GDB always does if possible. If the
+ next source line cannot be displayed for some reason (e.g., if GDB
+ cannot find the source file, or there's no line info in the debug
+ info), GDB will display disassembly of the next _instruction_
+ instead of showing the next source line. If AUTO, GDB will
+ display disassembly of next instruction only if the source line
+ cannot be displayed. This setting causes GDB to display some
+ feedback when you step through a function with no line info or
+ whose source file is unavailable. The default is OFF, which means
+ never display the disassembly of the next line or instruction.
+
+
+File: gdb.info, Node: Data, Next: Optimized Code, Prev: Source, Up: Top
+
+10 Examining Data
+*****************
+
+The usual way to examine data in your program is with the `print'
+command (abbreviated `p'), or its synonym `inspect'. It evaluates and
+prints the value of an expression of the language your program is
+written in (*note Using GDB with Different Languages: Languages.). It
+may also print the expression using a Python-based pretty-printer
+(*note Pretty Printing::).
+
+`print EXPR'
+`print /F EXPR'
+ EXPR is an expression (in the source language). By default the
+ value of EXPR is printed in a format appropriate to its data type;
+ you can choose a different format by specifying `/F', where F is a
+ letter specifying the format; see *Note Output Formats: Output
+ Formats.
+
+`print'
+`print /F'
+ If you omit EXPR, GDB displays the last value again (from the
+ "value history"; *note Value History: Value History.). This
+ allows you to conveniently inspect the same value in an
+ alternative format.
+
+ A more low-level way of examining data is with the `x' command. It
+examines data in memory at a specified address and prints it in a
+specified format. *Note Examining Memory: Memory.
+
+ If you are interested in information about types, or about how the
+fields of a struct or a class are declared, use the `ptype EXP' command
+rather than `print'. *Note Examining the Symbol Table: Symbols.
+
+* Menu:
+
+* Expressions:: Expressions
+* Ambiguous Expressions:: Ambiguous Expressions
+* Variables:: Program variables
+* Arrays:: Artificial arrays
+* Output Formats:: Output formats
+* Memory:: Examining memory
+* Auto Display:: Automatic display
+* Print Settings:: Print settings
+* Pretty Printing:: Python pretty printing
+* Value History:: Value history
+* Convenience Vars:: Convenience variables
+* Registers:: Registers
+* Floating Point Hardware:: Floating point hardware
+* Vector Unit:: Vector Unit
+* OS Information:: Auxiliary data provided by operating system
+* Memory Region Attributes:: Memory region attributes
+* Dump/Restore Files:: Copy between memory and a file
+* Core File Generation:: Cause a program dump its core
+* Character Sets:: Debugging programs that use a different
+ character set than GDB does
+* Caching Remote Data:: Data caching for remote targets
+* Searching Memory:: Searching memory for a sequence of bytes
+
+
+File: gdb.info, Node: Expressions, Next: Ambiguous Expressions, Up: Data
+
+10.1 Expressions
+================
+
+`print' and many other GDB commands accept an expression and compute
+its value. Any kind of constant, variable or operator defined by the
+programming language you are using is valid in an expression in GDB.
+This includes conditional expressions, function calls, casts, and
+string constants. It also includes preprocessor macros, if you
+compiled your program to include this information; see *Note
+Compilation::.
+
+ GDB supports array constants in expressions input by the user. The
+syntax is {ELEMENT, ELEMENT...}. For example, you can use the command
+`print {1, 2, 3}' to create an array of three integers. If you pass an
+array to a function or assign it to a program variable, GDB copies the
+array to memory that is `malloc'ed in the target program.
+
+ Because C is so widespread, most of the expressions shown in
+examples in this manual are in C. *Note Using GDB with Different
+Languages: Languages, for information on how to use expressions in other
+languages.
+
+ In this section, we discuss operators that you can use in GDB
+expressions regardless of your programming language.
+
+ Casts are supported in all languages, not just in C, because it is so
+useful to cast a number into a pointer in order to examine a structure
+at that address in memory.
+
+ GDB supports these operators, in addition to those common to
+programming languages:
+
+`@'
+ `@' is a binary operator for treating parts of memory as arrays.
+ *Note Artificial Arrays: Arrays, for more information.
+
+`::'
+ `::' allows you to specify a variable in terms of the file or
+ function where it is defined. *Note Program Variables: Variables.
+
+`{TYPE} ADDR'
+ Refers to an object of type TYPE stored at address ADDR in memory.
+ ADDR may be any expression whose value is an integer or pointer
+ (but parentheses are required around binary operators, just as in
+ a cast). This construct is allowed regardless of what kind of
+ data is normally supposed to reside at ADDR.
+
+
+File: gdb.info, Node: Ambiguous Expressions, Next: Variables, Prev: Expressions, Up: Data
+
+10.2 Ambiguous Expressions
+==========================
+
+Expressions can sometimes contain some ambiguous elements. For
+instance, some programming languages (notably Ada, C++ and Objective-C)
+permit a single function name to be defined several times, for
+application in different contexts. This is called "overloading".
+Another example involving Ada is generics. A "generic package" is
+similar to C++ templates and is typically instantiated several times,
+resulting in the same function name being defined in different contexts.
+
+ In some cases and depending on the language, it is possible to adjust
+the expression to remove the ambiguity. For instance in C++, you can
+specify the signature of the function you want to break on, as in
+`break FUNCTION(TYPES)'. In Ada, using the fully qualified name of
+your function often makes the expression unambiguous as well.
+
+ When an ambiguity that needs to be resolved is detected, the debugger
+has the capability to display a menu of numbered choices for each
+possibility, and then waits for the selection with the prompt `>'. The
+first option is always `[0] cancel', and typing `0 <RET>' aborts the
+current command. If the command in which the expression was used
+allows more than one choice to be selected, the next option in the menu
+is `[1] all', and typing `1 <RET>' selects all possible choices.
+
+ For example, the following session excerpt shows an attempt to set a
+breakpoint at the overloaded symbol `String::after'. We choose three
+particular definitions of that function name:
+
+ (gdb) b String::after
+ [0] cancel
+ [1] all
+ [2] file:String.cc; line number:867
+ [3] file:String.cc; line number:860
+ [4] file:String.cc; line number:875
+ [5] file:String.cc; line number:853
+ [6] file:String.cc; line number:846
+ [7] file:String.cc; line number:735
+ > 2 4 6
+ Breakpoint 1 at 0xb26c: file String.cc, line 867.
+ Breakpoint 2 at 0xb344: file String.cc, line 875.
+ Breakpoint 3 at 0xafcc: file String.cc, line 846.
+ Multiple breakpoints were set.
+ Use the "delete" command to delete unwanted
+ breakpoints.
+ (gdb)
+
+`set multiple-symbols MODE'
+ This option allows you to adjust the debugger behavior when an
+ expression is ambiguous.
+
+ By default, MODE is set to `all'. If the command with which the
+ expression is used allows more than one choice, then GDB
+ automatically selects all possible choices. For instance,
+ inserting a breakpoint on a function using an ambiguous name
+ results in a breakpoint inserted on each possible match. However,
+ if a unique choice must be made, then GDB uses the menu to help
+ you disambiguate the expression. For instance, printing the
+ address of an overloaded function will result in the use of the
+ menu.
+
+ When MODE is set to `ask', the debugger always uses the menu when
+ an ambiguity is detected.
+
+ Finally, when MODE is set to `cancel', the debugger reports an
+ error due to the ambiguity and the command is aborted.
+
+`show multiple-symbols'
+ Show the current value of the `multiple-symbols' setting.
+
+
+File: gdb.info, Node: Variables, Next: Arrays, Prev: Ambiguous Expressions, Up: Data
+
+10.3 Program Variables
+======================
+
+The most common kind of expression to use is the name of a variable in
+your program.
+
+ Variables in expressions are understood in the selected stack frame
+(*note Selecting a Frame: Selection.); they must be either:
+
+ * global (or file-static)
+
+or
+
+ * visible according to the scope rules of the programming language
+ from the point of execution in that frame
+
+This means that in the function
+
+ foo (a)
+ int a;
+ {
+ bar (a);
+ {
+ int b = test ();
+ bar (b);
+ }
+ }
+
+you can examine and use the variable `a' whenever your program is
+executing within the function `foo', but you can only use or examine
+the variable `b' while your program is executing inside the block where
+`b' is declared.
+
+ There is an exception: you can refer to a variable or function whose
+scope is a single source file even if the current execution point is not
+in this file. But it is possible to have more than one such variable or
+function with the same name (in different source files). If that
+happens, referring to that name has unpredictable effects. If you wish,
+you can specify a static variable in a particular function or file,
+using the colon-colon (`::') notation:
+
+ FILE::VARIABLE
+ FUNCTION::VARIABLE
+
+Here FILE or FUNCTION is the name of the context for the static
+VARIABLE. In the case of file names, you can use quotes to make sure
+GDB parses the file name as a single word--for example, to print a
+global value of `x' defined in `f2.c':
+
+ (gdb) p 'f2.c'::x
+
+ This use of `::' is very rarely in conflict with the very similar
+use of the same notation in C++. GDB also supports use of the C++
+scope resolution operator in GDB expressions.
+
+ _Warning:_ Occasionally, a local variable may appear to have the
+ wrong value at certain points in a function--just after entry to a
+ new scope, and just before exit.
+ You may see this problem when you are stepping by machine
+instructions. This is because, on most machines, it takes more than
+one instruction to set up a stack frame (including local variable
+definitions); if you are stepping by machine instructions, variables
+may appear to have the wrong values until the stack frame is completely
+built. On exit, it usually also takes more than one machine
+instruction to destroy a stack frame; after you begin stepping through
+that group of instructions, local variable definitions may be gone.
+
+ This may also happen when the compiler does significant
+optimizations. To be sure of always seeing accurate values, turn off
+all optimization when compiling.
+
+ Another possible effect of compiler optimizations is to optimize
+unused variables out of existence, or assign variables to registers (as
+opposed to memory addresses). Depending on the support for such cases
+offered by the debug info format used by the compiler, GDB might not be
+able to display values for such local variables. If that happens, GDB
+will print a message like this:
+
+ No symbol "foo" in current context.
+
+ To solve such problems, either recompile without optimizations, or
+use a different debug info format, if the compiler supports several such
+formats. *Note Compilation::, for more information on choosing compiler
+options. *Note C and C++: C, for more information about debug info
+formats that are best suited to C++ programs.
+
+ If you ask to print an object whose contents are unknown to GDB,
+e.g., because its data type is not completely specified by the debug
+information, GDB will say `<incomplete type>'. *Note incomplete type:
+Symbols, for more about this.
+
+ If you append `@entry' string to a function parameter name you get
+its value at the time the function got called. If the value is not
+available an error message is printed. Entry values are available only
+with some compilers. Entry values are normally also printed at the
+function parameter list according to *Note set print entry-values::.
+
+ Breakpoint 1, d (i=30) at gdb.base/entry-value.c:29
+ 29 i++;
+ (gdb) next
+ 30 e (i);
+ (gdb) print i
+ $1 = 31
+ (gdb) print i@entry
+ $2 = 30
+
+ Strings are identified as arrays of `char' values without specified
+signedness. Arrays of either `signed char' or `unsigned char' get
+printed as arrays of 1 byte sized integers. `-fsigned-char' or
+`-funsigned-char' GCC options have no effect as GDB defines literal
+string type `"char"' as `char' without a sign. For program code
+
+ char var0[] = "A";
+ signed char var1[] = "A";
+
+ You get during debugging
+ (gdb) print var0
+ $1 = "A"
+ (gdb) print var1
+ $2 = {65 'A', 0 '\0'}
+
+
+File: gdb.info, Node: Arrays, Next: Output Formats, Prev: Variables, Up: Data
+
+10.4 Artificial Arrays
+======================
+
+It is often useful to print out several successive objects of the same
+type in memory; a section of an array, or an array of dynamically
+determined size for which only a pointer exists in the program.
+
+ You can do this by referring to a contiguous span of memory as an
+"artificial array", using the binary operator `@'. The left operand of
+`@' should be the first element of the desired array and be an
+individual object. The right operand should be the desired length of
+the array. The result is an array value whose elements are all of the
+type of the left argument. The first element is actually the left
+argument; the second element comes from bytes of memory immediately
+following those that hold the first element, and so on. Here is an
+example. If a program says
+
+ int *array = (int *) malloc (len * sizeof (int));
+
+you can print the contents of `array' with
+
+ p *array@len
+
+ The left operand of `@' must reside in memory. Array values made
+with `@' in this way behave just like other arrays in terms of
+subscripting, and are coerced to pointers when used in expressions.
+Artificial arrays most often appear in expressions via the value history
+(*note Value History: Value History.), after printing one out.
+
+ Another way to create an artificial array is to use a cast. This
+re-interprets a value as if it were an array. The value need not be in
+memory:
+ (gdb) p/x (short[2])0x12345678
+ $1 = {0x1234, 0x5678}
+
+ As a convenience, if you leave the array length out (as in
+`(TYPE[])VALUE') GDB calculates the size to fill the value (as
+`sizeof(VALUE)/sizeof(TYPE)':
+ (gdb) p/x (short[])0x12345678
+ $2 = {0x1234, 0x5678}
+
+ Sometimes the artificial array mechanism is not quite enough; in
+moderately complex data structures, the elements of interest may not
+actually be adjacent--for example, if you are interested in the values
+of pointers in an array. One useful work-around in this situation is
+to use a convenience variable (*note Convenience Variables: Convenience
+Vars.) as a counter in an expression that prints the first interesting
+value, and then repeat that expression via <RET>. For instance,
+suppose you have an array `dtab' of pointers to structures, and you are
+interested in the values of a field `fv' in each structure. Here is an
+example of what you might type:
+
+ set $i = 0
+ p dtab[$i++]->fv
+ <RET>
+ <RET>
+ ...
+
+
+File: gdb.info, Node: Output Formats, Next: Memory, Prev: Arrays, Up: Data
+
+10.5 Output Formats
+===================
+
+By default, GDB prints a value according to its data type. Sometimes
+this is not what you want. For example, you might want to print a
+number in hex, or a pointer in decimal. Or you might want to view data
+in memory at a certain address as a character string or as an
+instruction. To do these things, specify an "output format" when you
+print a value.
+
+ The simplest use of output formats is to say how to print a value
+already computed. This is done by starting the arguments of the
+`print' command with a slash and a format letter. The format letters
+supported are:
+
+`x'
+ Regard the bits of the value as an integer, and print the integer
+ in hexadecimal.
+
+`d'
+ Print as integer in signed decimal.
+
+`u'
+ Print as integer in unsigned decimal.
+
+`o'
+ Print as integer in octal.
+
+`t'
+ Print as integer in binary. The letter `t' stands for "two". (1)
+
+`a'
+ Print as an address, both absolute in hexadecimal and as an offset
+ from the nearest preceding symbol. You can use this format used
+ to discover where (in what function) an unknown address is located:
+
+ (gdb) p/a 0x54320
+ $3 = 0x54320 <_initialize_vx+396>
+
+ The command `info symbol 0x54320' yields similar results. *Note
+ info symbol: Symbols.
+
+`c'
+ Regard as an integer and print it as a character constant. This
+ prints both the numerical value and its character representation.
+ The character representation is replaced with the octal escape
+ `\nnn' for characters outside the 7-bit ASCII range.
+
+ Without this format, GDB displays `char', `unsigned char', and
+ `signed char' data as character constants. Single-byte members of
+ vectors are displayed as integer data.
+
+`f'
+ Regard the bits of the value as a floating point number and print
+ using typical floating point syntax.
+
+`s'
+ Regard as a string, if possible. With this format, pointers to
+ single-byte data are displayed as null-terminated strings and
+ arrays of single-byte data are displayed as fixed-length strings.
+ Other values are displayed in their natural types.
+
+ Without this format, GDB displays pointers to and arrays of
+ `char', `unsigned char', and `signed char' as strings.
+ Single-byte members of a vector are displayed as an integer array.
+
+`r'
+ Print using the `raw' formatting. By default, GDB will use a
+ Python-based pretty-printer, if one is available (*note Pretty
+ Printing::). This typically results in a higher-level display of
+ the value's contents. The `r' format bypasses any Python
+ pretty-printer which might exist.
+
+ For example, to print the program counter in hex (*note
+Registers::), type
+
+ p/x $pc
+
+Note that no space is required before the slash; this is because command
+names in GDB cannot contain a slash.
+
+ To reprint the last value in the value history with a different
+format, you can use the `print' command with just a format and no
+expression. For example, `p/x' reprints the last value in hex.
+
+ ---------- Footnotes ----------
+
+ (1) `b' cannot be used because these format letters are also used
+with the `x' command, where `b' stands for "byte"; see *Note Examining
+Memory: Memory.
+
+
+File: gdb.info, Node: Memory, Next: Auto Display, Prev: Output Formats, Up: Data
+
+10.6 Examining Memory
+=====================
+
+You can use the command `x' (for "examine") to examine memory in any of
+several formats, independently of your program's data types.
+
+`x/NFU ADDR'
+`x ADDR'
+`x'
+ Use the `x' command to examine memory.
+
+ N, F, and U are all optional parameters that specify how much memory
+to display and how to format it; ADDR is an expression giving the
+address where you want to start displaying memory. If you use defaults
+for NFU, you need not type the slash `/'. Several commands set
+convenient defaults for ADDR.
+
+N, the repeat count
+ The repeat count is a decimal integer; the default is 1. It
+ specifies how much memory (counting by units U) to display.
+
+F, the display format
+ The display format is one of the formats used by `print' (`x',
+ `d', `u', `o', `t', `a', `c', `f', `s'), and in addition `i' (for
+ machine instructions). The default is `x' (hexadecimal)
+ initially. The default changes each time you use either `x' or
+ `print'.
+
+U, the unit size
+ The unit size is any of
+
+ `b'
+ Bytes.
+
+ `h'
+ Halfwords (two bytes).
+
+ `w'
+ Words (four bytes). This is the initial default.
+
+ `g'
+ Giant words (eight bytes).
+
+ Each time you specify a unit size with `x', that size becomes the
+ default unit the next time you use `x'. For the `i' format, the
+ unit size is ignored and is normally not written. For the `s'
+ format, the unit size defaults to `b', unless it is explicitly
+ given. Use `x /hs' to display 16-bit char strings and `x /ws' to
+ display 32-bit strings. The next use of `x /s' will again display
+ 8-bit strings. Note that the results depend on the programming
+ language of the current compilation unit. If the language is C,
+ the `s' modifier will use the UTF-16 encoding while `w' will use
+ UTF-32. The encoding is set by the programming language and cannot
+ be altered.
+
+ADDR, starting display address
+ ADDR is the address where you want GDB to begin displaying memory.
+ The expression need not have a pointer value (though it may); it
+ is always interpreted as an integer address of a byte of memory.
+ *Note Expressions: Expressions, for more information on
+ expressions. The default for ADDR is usually just after the last
+ address examined--but several other commands also set the default
+ address: `info breakpoints' (to the address of the last breakpoint
+ listed), `info line' (to the starting address of a line), and
+ `print' (if you use it to display a value from memory).
+
+ For example, `x/3uh 0x54320' is a request to display three halfwords
+(`h') of memory, formatted as unsigned decimal integers (`u'), starting
+at address `0x54320'. `x/4xw $sp' prints the four words (`w') of
+memory above the stack pointer (here, `$sp'; *note Registers:
+Registers.) in hexadecimal (`x').
+
+ Since the letters indicating unit sizes are all distinct from the
+letters specifying output formats, you do not have to remember whether
+unit size or format comes first; either order works. The output
+specifications `4xw' and `4wx' mean exactly the same thing. (However,
+the count N must come first; `wx4' does not work.)
+
+ Even though the unit size U is ignored for the formats `s' and `i',
+you might still want to use a count N; for example, `3i' specifies that
+you want to see three machine instructions, including any operands.
+For convenience, especially when used with the `display' command, the
+`i' format also prints branch delay slot instructions, if any, beyond
+the count specified, which immediately follow the last instruction that
+is within the count. The command `disassemble' gives an alternative
+way of inspecting machine instructions; see *Note Source and Machine
+Code: Machine Code.
+
+ All the defaults for the arguments to `x' are designed to make it
+easy to continue scanning memory with minimal specifications each time
+you use `x'. For example, after you have inspected three machine
+instructions with `x/3i ADDR', you can inspect the next seven with just
+`x/7'. If you use <RET> to repeat the `x' command, the repeat count N
+is used again; the other arguments default as for successive uses of
+`x'.
+
+ When examining machine instructions, the instruction at current
+program counter is shown with a `=>' marker. For example:
+
+ (gdb) x/5i $pc-6
+ 0x804837f <main+11>: mov %esp,%ebp
+ 0x8048381 <main+13>: push %ecx
+ 0x8048382 <main+14>: sub $0x4,%esp
+ => 0x8048385 <main+17>: movl $0x8048460,(%esp)
+ 0x804838c <main+24>: call 0x80482d4 <puts@plt>
+
+ The addresses and contents printed by the `x' command are not saved
+in the value history because there is often too much of them and they
+would get in the way. Instead, GDB makes these values available for
+subsequent use in expressions as values of the convenience variables
+`$_' and `$__'. After an `x' command, the last address examined is
+available for use in expressions in the convenience variable `$_'. The
+contents of that address, as examined, are available in the convenience
+variable `$__'.
+
+ If the `x' command has a repeat count, the address and contents saved
+are from the last memory unit printed; this is not the same as the last
+address printed if several units were printed on the last line of
+output.
+
+ When you are debugging a program running on a remote target machine
+(*note Remote Debugging::), you may wish to verify the program's image
+in the remote machine's memory against the executable file you
+downloaded to the target. The `compare-sections' command is provided
+for such situations.
+
+`compare-sections [SECTION-NAME]'
+ Compare the data of a loadable section SECTION-NAME in the
+ executable file of the program being debugged with the same
+ section in the remote machine's memory, and report any mismatches.
+ With no arguments, compares all loadable sections. This command's
+ availability depends on the target's support for the `"qCRC"'
+ remote request.
+
+
+File: gdb.info, Node: Auto Display, Next: Print Settings, Prev: Memory, Up: Data
+
+10.7 Automatic Display
+======================
+
+If you find that you want to print the value of an expression frequently
+(to see how it changes), you might want to add it to the "automatic
+display list" so that GDB prints its value each time your program stops.
+Each expression added to the list is given a number to identify it; to
+remove an expression from the list, you specify that number. The
+automatic display looks like this:
+
+ 2: foo = 38
+ 3: bar[5] = (struct hack *) 0x3804
+
+This display shows item numbers, expressions and their current values.
+As with displays you request manually using `x' or `print', you can
+specify the output format you prefer; in fact, `display' decides
+whether to use `print' or `x' depending your format specification--it
+uses `x' if you specify either the `i' or `s' format, or a unit size;
+otherwise it uses `print'.
+
+`display EXPR'
+ Add the expression EXPR to the list of expressions to display each
+ time your program stops. *Note Expressions: Expressions.
+
+ `display' does not repeat if you press <RET> again after using it.
+
+`display/FMT EXPR'
+ For FMT specifying only a display format and not a size or count,
+ add the expression EXPR to the auto-display list but arrange to
+ display it each time in the specified format FMT. *Note Output
+ Formats: Output Formats.
+
+`display/FMT ADDR'
+ For FMT `i' or `s', or including a unit-size or a number of units,
+ add the expression ADDR as a memory address to be examined each
+ time your program stops. Examining means in effect doing `x/FMT
+ ADDR'. *Note Examining Memory: Memory.
+
+ For example, `display/i $pc' can be helpful, to see the machine
+instruction about to be executed each time execution stops (`$pc' is a
+common name for the program counter; *note Registers: Registers.).
+
+`undisplay DNUMS...'
+`delete display DNUMS...'
+ Remove items from the list of expressions to display. Specify the
+ numbers of the displays that you want affected with the command
+ argument DNUMS. It can be a single display number, one of the
+ numbers shown in the first field of the `info display' display; or
+ it could be a range of display numbers, as in `2-4'.
+
+ `undisplay' does not repeat if you press <RET> after using it.
+ (Otherwise you would just get the error `No display number ...'.)
+
+`disable display DNUMS...'
+ Disable the display of item numbers DNUMS. A disabled display
+ item is not printed automatically, but is not forgotten. It may be
+ enabled again later. Specify the numbers of the displays that you
+ want affected with the command argument DNUMS. It can be a single
+ display number, one of the numbers shown in the first field of the
+ `info display' display; or it could be a range of display numbers,
+ as in `2-4'.
+
+`enable display DNUMS...'
+ Enable display of item numbers DNUMS. It becomes effective once
+ again in auto display of its expression, until you specify
+ otherwise. Specify the numbers of the displays that you want
+ affected with the command argument DNUMS. It can be a single
+ display number, one of the numbers shown in the first field of the
+ `info display' display; or it could be a range of display numbers,
+ as in `2-4'.
+
+`display'
+ Display the current values of the expressions on the list, just as
+ is done when your program stops.
+
+`info display'
+ Print the list of expressions previously set up to display
+ automatically, each one with its item number, but without showing
+ the values. This includes disabled expressions, which are marked
+ as such. It also includes expressions which would not be
+ displayed right now because they refer to automatic variables not
+ currently available.
+
+ If a display expression refers to local variables, then it does not
+make sense outside the lexical context for which it was set up. Such an
+expression is disabled when execution enters a context where one of its
+variables is not defined. For example, if you give the command
+`display last_char' while inside a function with an argument
+`last_char', GDB displays this argument while your program continues to
+stop inside that function. When it stops elsewhere--where there is no
+variable `last_char'--the display is disabled automatically. The next
+time your program stops where `last_char' is meaningful, you can enable
+the display expression once again.
+
+
+File: gdb.info, Node: Print Settings, Next: Pretty Printing, Prev: Auto Display, Up: Data
+
+10.8 Print Settings
+===================
+
+GDB provides the following ways to control how arrays, structures, and
+symbols are printed.
+
+These settings are useful for debugging programs in any language:
+
+`set print address'
+`set print address on'
+ GDB prints memory addresses showing the location of stack traces,
+ structure values, pointer values, breakpoints, and so forth, even
+ when it also displays the contents of those addresses. The default
+ is `on'. For example, this is what a stack frame display looks
+ like with `set print address on':
+
+ (gdb) f
+ #0 set_quotes (lq=0x34c78 "<<", rq=0x34c88 ">>")
+ at input.c:530
+ 530 if (lquote != def_lquote)
+
+`set print address off'
+ Do not print addresses when displaying their contents. For
+ example, this is the same stack frame displayed with `set print
+ address off':
+
+ (gdb) set print addr off
+ (gdb) f
+ #0 set_quotes (lq="<<", rq=">>") at input.c:530
+ 530 if (lquote != def_lquote)
+
+ You can use `set print address off' to eliminate all machine
+ dependent displays from the GDB interface. For example, with
+ `print address off', you should get the same text for backtraces on
+ all machines--whether or not they involve pointer arguments.
+
+`show print address'
+ Show whether or not addresses are to be printed.
+
+ When GDB prints a symbolic address, it normally prints the closest
+earlier symbol plus an offset. If that symbol does not uniquely
+identify the address (for example, it is a name whose scope is a single
+source file), you may need to clarify. One way to do this is with
+`info line', for example `info line *0x4537'. Alternately, you can set
+GDB to print the source file and line number when it prints a symbolic
+address:
+
+`set print symbol-filename on'
+ Tell GDB to print the source file name and line number of a symbol
+ in the symbolic form of an address.
+
+`set print symbol-filename off'
+ Do not print source file name and line number of a symbol. This
+ is the default.
+
+`show print symbol-filename'
+ Show whether or not GDB will print the source file name and line
+ number of a symbol in the symbolic form of an address.
+
+ Another situation where it is helpful to show symbol filenames and
+line numbers is when disassembling code; GDB shows you the line number
+and source file that corresponds to each instruction.
+
+ Also, you may wish to see the symbolic form only if the address being
+printed is reasonably close to the closest earlier symbol:
+
+`set print max-symbolic-offset MAX-OFFSET'
+ Tell GDB to only display the symbolic form of an address if the
+ offset between the closest earlier symbol and the address is less
+ than MAX-OFFSET. The default is 0, which tells GDB to always
+ print the symbolic form of an address if any symbol precedes it.
+
+`show print max-symbolic-offset'
+ Ask how large the maximum offset is that GDB prints in a symbolic
+ address.
+
+ If you have a pointer and you are not sure where it points, try `set
+print symbol-filename on'. Then you can determine the name and source
+file location of the variable where it points, using `p/a POINTER'.
+This interprets the address in symbolic form. For example, here GDB
+shows that a variable `ptt' points at another variable `t', defined in
+`hi2.c':
+
+ (gdb) set print symbol-filename on
+ (gdb) p/a ptt
+ $4 = 0xe008 <t in hi2.c>
+
+ _Warning:_ For pointers that point to a local variable, `p/a' does
+ not show the symbol name and filename of the referent, even with
+ the appropriate `set print' options turned on.
+
+ Other settings control how different kinds of objects are printed:
+
+`set print array'
+`set print array on'
+ Pretty print arrays. This format is more convenient to read, but
+ uses more space. The default is off.
+
+`set print array off'
+ Return to compressed format for arrays.
+
+`show print array'
+ Show whether compressed or pretty format is selected for displaying
+ arrays.
+
+`set print array-indexes'
+`set print array-indexes on'
+ Print the index of each element when displaying arrays. May be
+ more convenient to locate a given element in the array or quickly
+ find the index of a given element in that printed array. The
+ default is off.
+
+`set print array-indexes off'
+ Stop printing element indexes when displaying arrays.
+
+`show print array-indexes'
+ Show whether the index of each element is printed when displaying
+ arrays.
+
+`set print elements NUMBER-OF-ELEMENTS'
+ Set a limit on how many elements of an array GDB will print. If
+ GDB is printing a large array, it stops printing after it has
+ printed the number of elements set by the `set print elements'
+ command. This limit also applies to the display of strings. When
+ GDB starts, this limit is set to 200. Setting NUMBER-OF-ELEMENTS
+ to zero means that the printing is unlimited.
+
+`show print elements'
+ Display the number of elements of a large array that GDB will
+ print. If the number is 0, then the printing is unlimited.
+
+`set print frame-arguments VALUE'
+ This command allows to control how the values of arguments are
+ printed when the debugger prints a frame (*note Frames::). The
+ possible values are:
+
+ `all'
+ The values of all arguments are printed.
+
+ `scalars'
+ Print the value of an argument only if it is a scalar. The
+ value of more complex arguments such as arrays, structures,
+ unions, etc, is replaced by `...'. This is the default.
+ Here is an example where only scalar arguments are shown:
+
+ #1 0x08048361 in call_me (i=3, s=..., ss=0xbf8d508c, u=..., e=green)
+ at frame-args.c:23
+
+ `none'
+ None of the argument values are printed. Instead, the value
+ of each argument is replaced by `...'. In this case, the
+ example above now becomes:
+
+ #1 0x08048361 in call_me (i=..., s=..., ss=..., u=..., e=...)
+ at frame-args.c:23
+
+ By default, only scalar arguments are printed. This command can
+ be used to configure the debugger to print the value of all
+ arguments, regardless of their type. However, it is often
+ advantageous to not print the value of more complex parameters.
+ For instance, it reduces the amount of information printed in each
+ frame, making the backtrace more readable. Also, it improves
+ performance when displaying Ada frames, because the computation of
+ large arguments can sometimes be CPU-intensive, especially in
+ large applications. Setting `print frame-arguments' to `scalars'
+ (the default) or `none' avoids this computation, thus speeding up
+ the display of each Ada frame.
+
+`show print frame-arguments'
+ Show how the value of arguments should be displayed when printing
+ a frame.
+
+`set print entry-values VALUE'
+ Set printing of frame argument values at function entry. In some
+ cases GDB can determine the value of function argument which was
+ passed by the function caller, even if the value was modified
+ inside the called function and therefore is different. With
+ optimized code, the current value could be unavailable, but the
+ entry value may still be known.
+
+ The default value is `default' (see below for its description).
+ Older GDB behaved as with the setting `no'. Compilers not
+ supporting this feature will behave in the `default' setting the
+ same way as with the `no' setting.
+
+ This functionality is currently supported only by DWARF 2
+ debugging format and the compiler has to produce
+ `DW_TAG_GNU_call_site' tags. With GCC, you need to specify `-O
+ -g' during compilation, to get this information.
+
+ The VALUE parameter can be one of the following:
+
+ `no'
+ Print only actual parameter values, never print values from
+ function entry point.
+ #0 equal (val=5)
+ #0 different (val=6)
+ #0 lost (val=<optimized out>)
+ #0 born (val=10)
+ #0 invalid (val=<optimized out>)
+
+ `only'
+ Print only parameter values from function entry point. The
+ actual parameter values are never printed.
+ #0 equal (val@entry=5)
+ #0 different (val@entry=5)
+ #0 lost (val@entry=5)
+ #0 born (val@entry=<optimized out>)
+ #0 invalid (val@entry=<optimized out>)
+
+ `preferred'
+ Print only parameter values from function entry point. If
+ value from function entry point is not known while the actual
+ value is known, print the actual value for such parameter.
+ #0 equal (val@entry=5)
+ #0 different (val@entry=5)
+ #0 lost (val@entry=5)
+ #0 born (val=10)
+ #0 invalid (val@entry=<optimized out>)
+
+ `if-needed'
+ Print actual parameter values. If actual parameter value is
+ not known while value from function entry point is known,
+ print the entry point value for such parameter.
+ #0 equal (val=5)
+ #0 different (val=6)
+ #0 lost (val@entry=5)
+ #0 born (val=10)
+ #0 invalid (val=<optimized out>)
+
+ `both'
+ Always print both the actual parameter value and its value
+ from function entry point, even if values of one or both are
+ not available due to compiler optimizations.
+ #0 equal (val=5, val@entry=5)
+ #0 different (val=6, val@entry=5)
+ #0 lost (val=<optimized out>, val@entry=5)
+ #0 born (val=10, val@entry=<optimized out>)
+ #0 invalid (val=<optimized out>, val@entry=<optimized out>)
+
+ `compact'
+ Print the actual parameter value if it is known and also its
+ value from function entry point if it is known. If neither
+ is known, print for the actual value `<optimized out>'. If
+ not in MI mode (*note GDB/MI::) and if both values are known
+ and identical, print the shortened `param=param@entry=VALUE'
+ notation.
+ #0 equal (val=val@entry=5)
+ #0 different (val=6, val@entry=5)
+ #0 lost (val@entry=5)
+ #0 born (val=10)
+ #0 invalid (val=<optimized out>)
+
+ `default'
+ Always print the actual parameter value. Print also its
+ value from function entry point, but only if it is known. If
+ not in MI mode (*note GDB/MI::) and if both values are known
+ and identical, print the shortened `param=param@entry=VALUE'
+ notation.
+ #0 equal (val=val@entry=5)
+ #0 different (val=6, val@entry=5)
+ #0 lost (val=<optimized out>, val@entry=5)
+ #0 born (val=10)
+ #0 invalid (val=<optimized out>)
+
+ For analysis messages on possible failures of frame argument
+ values at function entry resolution see *Note set debug
+ entry-values::.
+
+`show print entry-values'
+ Show the method being used for printing of frame argument values
+ at function entry.
+
+`set print repeats'
+ Set the threshold for suppressing display of repeated array
+ elements. When the number of consecutive identical elements of an
+ array exceeds the threshold, GDB prints the string `"<repeats N
+ times>"', where N is the number of identical repetitions, instead
+ of displaying the identical elements themselves. Setting the
+ threshold to zero will cause all elements to be individually
+ printed. The default threshold is 10.
+
+`show print repeats'
+ Display the current threshold for printing repeated identical
+ elements.
+
+`set print null-stop'
+ Cause GDB to stop printing the characters of an array when the
+ first NULL is encountered. This is useful when large arrays
+ actually contain only short strings. The default is off.
+
+`show print null-stop'
+ Show whether GDB stops printing an array on the first NULL
+ character.
+
+`set print pretty on'
+ Cause GDB to print structures in an indented format with one member
+ per line, like this:
+
+ $1 = {
+ next = 0x0,
+ flags = {
+ sweet = 1,
+ sour = 1
+ },
+ meat = 0x54 "Pork"
+ }
+
+`set print pretty off'
+ Cause GDB to print structures in a compact format, like this:
+
+ $1 = {next = 0x0, flags = {sweet = 1, sour = 1}, \
+ meat = 0x54 "Pork"}
+
+ This is the default format.
+
+`show print pretty'
+ Show which format GDB is using to print structures.
+
+`set print sevenbit-strings on'
+ Print using only seven-bit characters; if this option is set, GDB
+ displays any eight-bit characters (in strings or character values)
+ using the notation `\'NNN. This setting is best if you are
+ working in English (ASCII) and you use the high-order bit of
+ characters as a marker or "meta" bit.
+
+`set print sevenbit-strings off'
+ Print full eight-bit characters. This allows the use of more
+ international character sets, and is the default.
+
+`show print sevenbit-strings'
+ Show whether or not GDB is printing only seven-bit characters.
+
+`set print union on'
+ Tell GDB to print unions which are contained in structures and
+ other unions. This is the default setting.
+
+`set print union off'
+ Tell GDB not to print unions which are contained in structures and
+ other unions. GDB will print `"{...}"' instead.
+
+`show print union'
+ Ask GDB whether or not it will print unions which are contained in
+ structures and other unions.
+
+ For example, given the declarations
+
+ typedef enum {Tree, Bug} Species;
+ typedef enum {Big_tree, Acorn, Seedling} Tree_forms;
+ typedef enum {Caterpillar, Cocoon, Butterfly}
+ Bug_forms;
+
+ struct thing {
+ Species it;
+ union {
+ Tree_forms tree;
+ Bug_forms bug;
+ } form;
+ };
+
+ struct thing foo = {Tree, {Acorn}};
+
+ with `set print union on' in effect `p foo' would print
+
+ $1 = {it = Tree, form = {tree = Acorn, bug = Cocoon}}
+
+ and with `set print union off' in effect it would print
+
+ $1 = {it = Tree, form = {...}}
+
+ `set print union' affects programs written in C-like languages and
+ in Pascal.
+
+These settings are of interest when debugging C++ programs:
+
+`set print demangle'
+`set print demangle on'
+ Print C++ names in their source form rather than in the encoded
+ ("mangled") form passed to the assembler and linker for type-safe
+ linkage. The default is on.
+
+`show print demangle'
+ Show whether C++ names are printed in mangled or demangled form.
+
+`set print asm-demangle'
+`set print asm-demangle on'
+ Print C++ names in their source form rather than their mangled
+ form, even in assembler code printouts such as instruction
+ disassemblies. The default is off.
+
+`show print asm-demangle'
+ Show whether C++ names in assembly listings are printed in mangled
+ or demangled form.
+
+`set demangle-style STYLE'
+ Choose among several encoding schemes used by different compilers
+ to represent C++ names. The choices for STYLE are currently:
+
+ `auto'
+ Allow GDB to choose a decoding style by inspecting your
+ program.
+
+ `gnu'
+ Decode based on the GNU C++ compiler (`g++') encoding
+ algorithm. This is the default.
+
+ `hp'
+ Decode based on the HP ANSI C++ (`aCC') encoding algorithm.
+
+ `lucid'
+ Decode based on the Lucid C++ compiler (`lcc') encoding
+ algorithm.
+
+ `arm'
+ Decode using the algorithm in the `C++ Annotated Reference
+ Manual'. *Warning:* this setting alone is not sufficient to
+ allow debugging `cfront'-generated executables. GDB would
+ require further enhancement to permit that.
+
+ If you omit STYLE, you will see a list of possible formats.
+
+`show demangle-style'
+ Display the encoding style currently in use for decoding C++
+ symbols.
+
+`set print object'
+`set print object on'
+ When displaying a pointer to an object, identify the _actual_
+ (derived) type of the object rather than the _declared_ type, using
+ the virtual function table. Note that the virtual function table
+ is required--this feature can only work for objects that have
+ run-time type identification; a single virtual method in the
+ object's declared type is sufficient.
+
+`set print object off'
+ Display only the declared type of objects, without reference to the
+ virtual function table. This is the default setting.
+
+`show print object'
+ Show whether actual, or declared, object types are displayed.
+
+`set print static-members'
+`set print static-members on'
+ Print static members when displaying a C++ object. The default is
+ on.
+
+`set print static-members off'
+ Do not print static members when displaying a C++ object.
+
+`show print static-members'
+ Show whether C++ static members are printed or not.
+
+`set print pascal_static-members'
+`set print pascal_static-members on'
+ Print static members when displaying a Pascal object. The default
+ is on.
+
+`set print pascal_static-members off'
+ Do not print static members when displaying a Pascal object.
+
+`show print pascal_static-members'
+ Show whether Pascal static members are printed or not.
+
+`set print vtbl'
+`set print vtbl on'
+ Pretty print C++ virtual function tables. The default is off.
+ (The `vtbl' commands do not work on programs compiled with the HP
+ ANSI C++ compiler (`aCC').)
+
+`set print vtbl off'
+ Do not pretty print C++ virtual function tables.
+
+`show print vtbl'
+ Show whether C++ virtual function tables are pretty printed, or
+ not.
+
diff --git a/gdb/doc/gdb.info-2 b/gdb/doc/gdb.info-2
new file mode 100644
index 0000000..2711f44
--- /dev/null
+++ b/gdb/doc/gdb.info-2
@@ -0,0 +1,7249 @@
+This is gdb.info, produced by makeinfo version 4.8 from ./gdb.texinfo.
+
+INFO-DIR-SECTION Software development
+START-INFO-DIR-ENTRY
+* Gdb: (gdb). The GNU debugger.
+END-INFO-DIR-ENTRY
+
+ Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996,
+1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009,
+2010 Free Software Foundation, Inc.
+
+ Permission is granted to copy, distribute and/or modify this document
+under the terms of the GNU Free Documentation License, Version 1.3 or
+any later version published by the Free Software Foundation; with the
+Invariant Sections being "Free Software" and "Free Software Needs Free
+Documentation", with the Front-Cover Texts being "A GNU Manual," and
+with the Back-Cover Texts as in (a) below.
+
+ (a) The FSF's Back-Cover Text is: "You are free to copy and modify
+this GNU Manual. Buying copies from GNU Press supports the FSF in
+developing GNU and promoting software freedom."
+
+ This file documents the GNU debugger GDB.
+
+ This is the Tenth Edition, of `Debugging with GDB: the GNU
+Source-Level Debugger' for GDB (GDB) Version 7.4.1.
+
+ Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996,
+1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009,
+2010 Free Software Foundation, Inc.
+
+ Permission is granted to copy, distribute and/or modify this document
+under the terms of the GNU Free Documentation License, Version 1.3 or
+any later version published by the Free Software Foundation; with the
+Invariant Sections being "Free Software" and "Free Software Needs Free
+Documentation", with the Front-Cover Texts being "A GNU Manual," and
+with the Back-Cover Texts as in (a) below.
+
+ (a) The FSF's Back-Cover Text is: "You are free to copy and modify
+this GNU Manual. Buying copies from GNU Press supports the FSF in
+developing GNU and promoting software freedom."
+
+
+File: gdb.info, Node: Pretty Printing, Next: Value History, Prev: Print Settings, Up: Data
+
+10.9 Pretty Printing
+====================
+
+GDB provides a mechanism to allow pretty-printing of values using
+Python code. It greatly simplifies the display of complex objects.
+This mechanism works for both MI and the CLI.
+
+* Menu:
+
+* Pretty-Printer Introduction:: Introduction to pretty-printers
+* Pretty-Printer Example:: An example pretty-printer
+* Pretty-Printer Commands:: Pretty-printer commands
+
+
+File: gdb.info, Node: Pretty-Printer Introduction, Next: Pretty-Printer Example, Up: Pretty Printing
+
+10.9.1 Pretty-Printer Introduction
+----------------------------------
+
+When GDB prints a value, it first sees if there is a pretty-printer
+registered for the value. If there is then GDB invokes the
+pretty-printer to print the value. Otherwise the value is printed
+normally.
+
+ Pretty-printers are normally named. This makes them easy to manage.
+The `info pretty-printer' command will list all the installed
+pretty-printers with their names. If a pretty-printer can handle
+multiple data types, then its "subprinters" are the printers for the
+individual data types. Each such subprinter has its own name. The
+format of the name is PRINTER-NAME;SUBPRINTER-NAME.
+
+ Pretty-printers are installed by "registering" them with GDB.
+Typically they are automatically loaded and registered when the
+corresponding debug information is loaded, thus making them available
+without having to do anything special.
+
+ There are three places where a pretty-printer can be registered.
+
+ * Pretty-printers registered globally are available when debugging
+ all inferiors.
+
+ * Pretty-printers registered with a program space are available only
+ when debugging that program. *Note Progspaces In Python::, for
+ more details on program spaces in Python.
+
+ * Pretty-printers registered with an objfile are loaded and unloaded
+ with the corresponding objfile (e.g., shared library). *Note
+ Objfiles In Python::, for more details on objfiles in Python.
+
+ *Note Selecting Pretty-Printers::, for further information on how
+pretty-printers are selected,
+
+ *Note Writing a Pretty-Printer::, for implementing pretty printers
+for new types.
+
+
+File: gdb.info, Node: Pretty-Printer Example, Next: Pretty-Printer Commands, Prev: Pretty-Printer Introduction, Up: Pretty Printing
+
+10.9.2 Pretty-Printer Example
+-----------------------------
+
+Here is how a C++ `std::string' looks without a pretty-printer:
+
+ (gdb) print s
+ $1 = {
+ static npos = 4294967295,
+ _M_dataplus = {
+ <std::allocator<char>> = {
+ <__gnu_cxx::new_allocator<char>> = {
+ <No data fields>}, <No data fields>
+ },
+ members of std::basic_string<char, std::char_traits<char>,
+ std::allocator<char> >::_Alloc_hider:
+ _M_p = 0x804a014 "abcd"
+ }
+ }
+
+ With a pretty-printer for `std::string' only the contents are
+printed:
+
+ (gdb) print s
+ $2 = "abcd"
+
+
+File: gdb.info, Node: Pretty-Printer Commands, Prev: Pretty-Printer Example, Up: Pretty Printing
+
+10.9.3 Pretty-Printer Commands
+------------------------------
+
+`info pretty-printer [OBJECT-REGEXP [NAME-REGEXP]]'
+ Print the list of installed pretty-printers. This includes
+ disabled pretty-printers, which are marked as such.
+
+ OBJECT-REGEXP is a regular expression matching the objects whose
+ pretty-printers to list. Objects can be `global', the program
+ space's file (*note Progspaces In Python::), and the object files
+ within that program space (*note Objfiles In Python::). *Note
+ Selecting Pretty-Printers::, for details on how GDB looks up a
+ printer from these three objects.
+
+ NAME-REGEXP is a regular expression matching the name of the
+ printers to list.
+
+`disable pretty-printer [OBJECT-REGEXP [NAME-REGEXP]]'
+ Disable pretty-printers matching OBJECT-REGEXP and NAME-REGEXP. A
+ disabled pretty-printer is not forgotten, it may be enabled again
+ later.
+
+`enable pretty-printer [OBJECT-REGEXP [NAME-REGEXP]]'
+ Enable pretty-printers matching OBJECT-REGEXP and NAME-REGEXP.
+
+ Example:
+
+ Suppose we have three pretty-printers installed: one from library1.so
+named `foo' that prints objects of type `foo', and another from
+library2.so named `bar' that prints two types of objects, `bar1' and
+`bar2'.
+
+ (gdb) info pretty-printer
+ library1.so:
+ foo
+ library2.so:
+ bar
+ bar1
+ bar2
+ (gdb) info pretty-printer library2
+ library2.so:
+ bar
+ bar1
+ bar2
+ (gdb) disable pretty-printer library1
+ 1 printer disabled
+ 2 of 3 printers enabled
+ (gdb) info pretty-printer
+ library1.so:
+ foo [disabled]
+ library2.so:
+ bar
+ bar1
+ bar2
+ (gdb) disable pretty-printer library2 bar:bar1
+ 1 printer disabled
+ 1 of 3 printers enabled
+ (gdb) info pretty-printer library2
+ library1.so:
+ foo [disabled]
+ library2.so:
+ bar
+ bar1 [disabled]
+ bar2
+ (gdb) disable pretty-printer library2 bar
+ 1 printer disabled
+ 0 of 3 printers enabled
+ (gdb) info pretty-printer library2
+ library1.so:
+ foo [disabled]
+ library2.so:
+ bar [disabled]
+ bar1 [disabled]
+ bar2
+
+ Note that for `bar' the entire printer can be disabled, as can each
+individual subprinter.
+
+
+File: gdb.info, Node: Value History, Next: Convenience Vars, Prev: Pretty Printing, Up: Data
+
+10.10 Value History
+===================
+
+Values printed by the `print' command are saved in the GDB "value
+history". This allows you to refer to them in other expressions.
+Values are kept until the symbol table is re-read or discarded (for
+example with the `file' or `symbol-file' commands). When the symbol
+table changes, the value history is discarded, since the values may
+contain pointers back to the types defined in the symbol table.
+
+ The values printed are given "history numbers" by which you can
+refer to them. These are successive integers starting with one.
+`print' shows you the history number assigned to a value by printing
+`$NUM = ' before the value; here NUM is the history number.
+
+ To refer to any previous value, use `$' followed by the value's
+history number. The way `print' labels its output is designed to
+remind you of this. Just `$' refers to the most recent value in the
+history, and `$$' refers to the value before that. `$$N' refers to the
+Nth value from the end; `$$2' is the value just prior to `$$', `$$1' is
+equivalent to `$$', and `$$0' is equivalent to `$'.
+
+ For example, suppose you have just printed a pointer to a structure
+and want to see the contents of the structure. It suffices to type
+
+ p *$
+
+ If you have a chain of structures where the component `next' points
+to the next one, you can print the contents of the next one with this:
+
+ p *$.next
+
+You can print successive links in the chain by repeating this
+command--which you can do by just typing <RET>.
+
+ Note that the history records values, not expressions. If the value
+of `x' is 4 and you type these commands:
+
+ print x
+ set x=5
+
+then the value recorded in the value history by the `print' command
+remains 4 even though the value of `x' has changed.
+
+`show values'
+ Print the last ten values in the value history, with their item
+ numbers. This is like `p $$9' repeated ten times, except that
+ `show values' does not change the history.
+
+`show values N'
+ Print ten history values centered on history item number N.
+
+`show values +'
+ Print ten history values just after the values last printed. If
+ no more values are available, `show values +' produces no display.
+
+ Pressing <RET> to repeat `show values N' has exactly the same effect
+as `show values +'.
+
+
+File: gdb.info, Node: Convenience Vars, Next: Registers, Prev: Value History, Up: Data
+
+10.11 Convenience Variables
+===========================
+
+GDB provides "convenience variables" that you can use within GDB to
+hold on to a value and refer to it later. These variables exist
+entirely within GDB; they are not part of your program, and setting a
+convenience variable has no direct effect on further execution of your
+program. That is why you can use them freely.
+
+ Convenience variables are prefixed with `$'. Any name preceded by
+`$' can be used for a convenience variable, unless it is one of the
+predefined machine-specific register names (*note Registers:
+Registers.). (Value history references, in contrast, are _numbers_
+preceded by `$'. *Note Value History: Value History.)
+
+ You can save a value in a convenience variable with an assignment
+expression, just as you would set a variable in your program. For
+example:
+
+ set $foo = *object_ptr
+
+would save in `$foo' the value contained in the object pointed to by
+`object_ptr'.
+
+ Using a convenience variable for the first time creates it, but its
+value is `void' until you assign a new value. You can alter the value
+with another assignment at any time.
+
+ Convenience variables have no fixed types. You can assign a
+convenience variable any type of value, including structures and
+arrays, even if that variable already has a value of a different type.
+The convenience variable, when used as an expression, has the type of
+its current value.
+
+`show convenience'
+ Print a list of convenience variables used so far, and their
+ values. Abbreviated `show conv'.
+
+`init-if-undefined $VARIABLE = EXPRESSION'
+ Set a convenience variable if it has not already been set. This
+ is useful for user-defined commands that keep some state. It is
+ similar, in concept, to using local static variables with
+ initializers in C (except that convenience variables are global).
+ It can also be used to allow users to override default values used
+ in a command script.
+
+ If the variable is already defined then the expression is not
+ evaluated so any side-effects do not occur.
+
+ One of the ways to use a convenience variable is as a counter to be
+incremented or a pointer to be advanced. For example, to print a field
+from successive elements of an array of structures:
+
+ set $i = 0
+ print bar[$i++]->contents
+
+Repeat that command by typing <RET>.
+
+ Some convenience variables are created automatically by GDB and given
+values likely to be useful.
+
+`$_'
+ The variable `$_' is automatically set by the `x' command to the
+ last address examined (*note Examining Memory: Memory.). Other
+ commands which provide a default address for `x' to examine also
+ set `$_' to that address; these commands include `info line' and
+ `info breakpoint'. The type of `$_' is `void *' except when set
+ by the `x' command, in which case it is a pointer to the type of
+ `$__'.
+
+`$__'
+ The variable `$__' is automatically set by the `x' command to the
+ value found in the last address examined. Its type is chosen to
+ match the format in which the data was printed.
+
+`$_exitcode'
+ The variable `$_exitcode' is automatically set to the exit code
+ when the program being debugged terminates.
+
+`$_sdata'
+ The variable `$_sdata' contains extra collected static tracepoint
+ data. *Note Tracepoint Action Lists: Tracepoint Actions. Note
+ that `$_sdata' could be empty, if not inspecting a trace buffer, or
+ if extra static tracepoint data has not been collected.
+
+`$_siginfo'
+ The variable `$_siginfo' contains extra signal information (*note
+ extra signal information::). Note that `$_siginfo' could be
+ empty, if the application has not yet received any signals. For
+ example, it will be empty before you execute the `run' command.
+
+`$_tlb'
+ The variable `$_tlb' is automatically set when debugging
+ applications running on MS-Windows in native mode or connected to
+ gdbserver that supports the `qGetTIBAddr' request. *Note General
+ Query Packets::. This variable contains the address of the thread
+ information block.
+
+
+ On HP-UX systems, if you refer to a function or variable name that
+begins with a dollar sign, GDB searches for a user or system name
+first, before it searches for a convenience variable.
+
+ GDB also supplies some "convenience functions". These have a syntax
+similar to convenience variables. A convenience function can be used
+in an expression just like an ordinary function; however, a convenience
+function is implemented internally to GDB.
+
+`help function'
+ Print a list of all convenience functions.
+
+
+File: gdb.info, Node: Registers, Next: Floating Point Hardware, Prev: Convenience Vars, Up: Data
+
+10.12 Registers
+===============
+
+You can refer to machine register contents, in expressions, as variables
+with names starting with `$'. The names of registers are different for
+each machine; use `info registers' to see the names used on your
+machine.
+
+`info registers'
+ Print the names and values of all registers except floating-point
+ and vector registers (in the selected stack frame).
+
+`info all-registers'
+ Print the names and values of all registers, including
+ floating-point and vector registers (in the selected stack frame).
+
+`info registers REGNAME ...'
+ Print the "relativized" value of each specified register REGNAME.
+ As discussed in detail below, register values are normally
+ relative to the selected stack frame. REGNAME may be any register
+ name valid on the machine you are using, with or without the
+ initial `$'.
+
+ GDB has four "standard" register names that are available (in
+expressions) on most machines--whenever they do not conflict with an
+architecture's canonical mnemonics for registers. The register names
+`$pc' and `$sp' are used for the program counter register and the stack
+pointer. `$fp' is used for a register that contains a pointer to the
+current stack frame, and `$ps' is used for a register that contains the
+processor status. For example, you could print the program counter in
+hex with
+
+ p/x $pc
+
+or print the instruction to be executed next with
+
+ x/i $pc
+
+or add four to the stack pointer(1) with
+
+ set $sp += 4
+
+ Whenever possible, these four standard register names are available
+on your machine even though the machine has different canonical
+mnemonics, so long as there is no conflict. The `info registers'
+command shows the canonical names. For example, on the SPARC, `info
+registers' displays the processor status register as `$psr' but you can
+also refer to it as `$ps'; and on x86-based machines `$ps' is an alias
+for the EFLAGS register.
+
+ GDB always considers the contents of an ordinary register as an
+integer when the register is examined in this way. Some machines have
+special registers which can hold nothing but floating point; these
+registers are considered to have floating point values. There is no way
+to refer to the contents of an ordinary register as floating point value
+(although you can _print_ it as a floating point value with `print/f
+$REGNAME').
+
+ Some registers have distinct "raw" and "virtual" data formats. This
+means that the data format in which the register contents are saved by
+the operating system is not the same one that your program normally
+sees. For example, the registers of the 68881 floating point
+coprocessor are always saved in "extended" (raw) format, but all C
+programs expect to work with "double" (virtual) format. In such cases,
+GDB normally works with the virtual format only (the format that makes
+sense for your program), but the `info registers' command prints the
+data in both formats.
+
+ Some machines have special registers whose contents can be
+interpreted in several different ways. For example, modern x86-based
+machines have SSE and MMX registers that can hold several values packed
+together in several different formats. GDB refers to such registers in
+`struct' notation:
+
+ (gdb) print $xmm1
+ $1 = {
+ v4_float = {0, 3.43859137e-038, 1.54142831e-044, 1.821688e-044},
+ v2_double = {9.92129282474342e-303, 2.7585945287983262e-313},
+ v16_int8 = "\000\000\000\000\3706;\001\v\000\000\000\r\000\000",
+ v8_int16 = {0, 0, 14072, 315, 11, 0, 13, 0},
+ v4_int32 = {0, 20657912, 11, 13},
+ v2_int64 = {88725056443645952, 55834574859},
+ uint128 = 0x0000000d0000000b013b36f800000000
+ }
+
+To set values of such registers, you need to tell GDB which view of the
+register you wish to change, as if you were assigning value to a
+`struct' member:
+
+ (gdb) set $xmm1.uint128 = 0x000000000000000000000000FFFFFFFF
+
+ Normally, register values are relative to the selected stack frame
+(*note Selecting a Frame: Selection.). This means that you get the
+value that the register would contain if all stack frames farther in
+were exited and their saved registers restored. In order to see the
+true contents of hardware registers, you must select the innermost
+frame (with `frame 0').
+
+ However, GDB must deduce where registers are saved, from the machine
+code generated by your compiler. If some registers are not saved, or if
+GDB is unable to locate the saved registers, the selected stack frame
+makes no difference.
+
+ ---------- Footnotes ----------
+
+ (1) This is a way of removing one word from the stack, on machines
+where stacks grow downward in memory (most machines, nowadays). This
+assumes that the innermost stack frame is selected; setting `$sp' is
+not allowed when other stack frames are selected. To pop entire frames
+off the stack, regardless of machine architecture, use `return'; see
+*Note Returning from a Function: Returning.
+
+
+File: gdb.info, Node: Floating Point Hardware, Next: Vector Unit, Prev: Registers, Up: Data
+
+10.13 Floating Point Hardware
+=============================
+
+Depending on the configuration, GDB may be able to give you more
+information about the status of the floating point hardware.
+
+`info float'
+ Display hardware-dependent information about the floating point
+ unit. The exact contents and layout vary depending on the
+ floating point chip. Currently, `info float' is supported on the
+ ARM and x86 machines.
+
+
+File: gdb.info, Node: Vector Unit, Next: OS Information, Prev: Floating Point Hardware, Up: Data
+
+10.14 Vector Unit
+=================
+
+Depending on the configuration, GDB may be able to give you more
+information about the status of the vector unit.
+
+`info vector'
+ Display information about the vector unit. The exact contents and
+ layout vary depending on the hardware.
+
+
+File: gdb.info, Node: OS Information, Next: Memory Region Attributes, Prev: Vector Unit, Up: Data
+
+10.15 Operating System Auxiliary Information
+============================================
+
+GDB provides interfaces to useful OS facilities that can help you debug
+your program.
+
+ When GDB runs on a "Posix system" (such as GNU or Unix machines), it
+interfaces with the inferior via the `ptrace' system call. The
+operating system creates a special sata structure, called `struct
+user', for this interface. You can use the command `info udot' to
+display the contents of this data structure.
+
+`info udot'
+ Display the contents of the `struct user' maintained by the OS
+ kernel for the program being debugged. GDB displays the contents
+ of `struct user' as a list of hex numbers, similar to the
+ `examine' command.
+
+ Some operating systems supply an "auxiliary vector" to programs at
+startup. This is akin to the arguments and environment that you
+specify for a program, but contains a system-dependent variety of
+binary values that tell system libraries important details about the
+hardware, operating system, and process. Each value's purpose is
+identified by an integer tag; the meanings are well-known but
+system-specific. Depending on the configuration and operating system
+facilities, GDB may be able to show you this information. For remote
+targets, this functionality may further depend on the remote stub's
+support of the `qXfer:auxv:read' packet, see *Note qXfer auxiliary
+vector read::.
+
+`info auxv'
+ Display the auxiliary vector of the inferior, which can be either a
+ live process or a core dump file. GDB prints each tag value
+ numerically, and also shows names and text descriptions for
+ recognized tags. Some values in the vector are numbers, some bit
+ masks, and some pointers to strings or other data. GDB displays
+ each value in the most appropriate form for a recognized tag, and
+ in hexadecimal for an unrecognized tag.
+
+ On some targets, GDB can access operating-system-specific information
+and display it to user, without interpretation. For remote targets,
+this functionality depends on the remote stub's support of the
+`qXfer:osdata:read' packet, see *Note qXfer osdata read::.
+
+`info os'
+ List the types of OS information available for the target. If the
+ target does not return a list of possible types, this command will
+ report an error.
+
+`info os processes'
+ Display the list of processes on the target. For each process,
+ GDB prints the process identifier, the name of the user, and the
+ command corresponding to the process.
+
+
+File: gdb.info, Node: Memory Region Attributes, Next: Dump/Restore Files, Prev: OS Information, Up: Data
+
+10.16 Memory Region Attributes
+==============================
+
+"Memory region attributes" allow you to describe special handling
+required by regions of your target's memory. GDB uses attributes to
+determine whether to allow certain types of memory accesses; whether to
+use specific width accesses; and whether to cache target memory. By
+default the description of memory regions is fetched from the target
+(if the current target supports this), but the user can override the
+fetched regions.
+
+ Defined memory regions can be individually enabled and disabled.
+When a memory region is disabled, GDB uses the default attributes when
+accessing memory in that region. Similarly, if no memory regions have
+been defined, GDB uses the default attributes when accessing all memory.
+
+ When a memory region is defined, it is given a number to identify it;
+to enable, disable, or remove a memory region, you specify that number.
+
+`mem LOWER UPPER ATTRIBUTES...'
+ Define a memory region bounded by LOWER and UPPER with attributes
+ ATTRIBUTES..., and add it to the list of regions monitored by GDB.
+ Note that UPPER == 0 is a special case: it is treated as the
+ target's maximum memory address. (0xffff on 16 bit targets,
+ 0xffffffff on 32 bit targets, etc.)
+
+`mem auto'
+ Discard any user changes to the memory regions and use
+ target-supplied regions, if available, or no regions if the target
+ does not support.
+
+`delete mem NUMS...'
+ Remove memory regions NUMS... from the list of regions monitored
+ by GDB.
+
+`disable mem NUMS...'
+ Disable monitoring of memory regions NUMS.... A disabled memory
+ region is not forgotten. It may be enabled again later.
+
+`enable mem NUMS...'
+ Enable monitoring of memory regions NUMS....
+
+`info mem'
+ Print a table of all defined memory regions, with the following
+ columns for each region:
+
+ _Memory Region Number_
+
+ _Enabled or Disabled._
+ Enabled memory regions are marked with `y'. Disabled memory
+ regions are marked with `n'.
+
+ _Lo Address_
+ The address defining the inclusive lower bound of the memory
+ region.
+
+ _Hi Address_
+ The address defining the exclusive upper bound of the memory
+ region.
+
+ _Attributes_
+ The list of attributes set for this memory region.
+
+10.16.1 Attributes
+------------------
+
+10.16.1.1 Memory Access Mode
+............................
+
+The access mode attributes set whether GDB may make read or write
+accesses to a memory region.
+
+ While these attributes prevent GDB from performing invalid memory
+accesses, they do nothing to prevent the target system, I/O DMA, etc.
+from accessing memory.
+
+`ro'
+ Memory is read only.
+
+`wo'
+ Memory is write only.
+
+`rw'
+ Memory is read/write. This is the default.
+
+10.16.1.2 Memory Access Size
+............................
+
+The access size attribute tells GDB to use specific sized accesses in
+the memory region. Often memory mapped device registers require
+specific sized accesses. If no access size attribute is specified, GDB
+may use accesses of any size.
+
+`8'
+ Use 8 bit memory accesses.
+
+`16'
+ Use 16 bit memory accesses.
+
+`32'
+ Use 32 bit memory accesses.
+
+`64'
+ Use 64 bit memory accesses.
+
+10.16.1.3 Data Cache
+....................
+
+The data cache attributes set whether GDB will cache target memory.
+While this generally improves performance by reducing debug protocol
+overhead, it can lead to incorrect results because GDB does not know
+about volatile variables or memory mapped device registers.
+
+`cache'
+ Enable GDB to cache target memory.
+
+`nocache'
+ Disable GDB from caching target memory. This is the default.
+
+10.16.2 Memory Access Checking
+------------------------------
+
+GDB can be instructed to refuse accesses to memory that is not
+explicitly described. This can be useful if accessing such regions has
+undesired effects for a specific target, or to provide better error
+checking. The following commands control this behaviour.
+
+`set mem inaccessible-by-default [on|off]'
+ If `on' is specified, make GDB treat memory not explicitly
+ described by the memory ranges as non-existent and refuse accesses
+ to such memory. The checks are only performed if there's at least
+ one memory range defined. If `off' is specified, make GDB treat
+ the memory not explicitly described by the memory ranges as RAM.
+ The default value is `on'.
+
+`show mem inaccessible-by-default'
+ Show the current handling of accesses to unknown memory.
+
+
+File: gdb.info, Node: Dump/Restore Files, Next: Core File Generation, Prev: Memory Region Attributes, Up: Data
+
+10.17 Copy Between Memory and a File
+====================================
+
+You can use the commands `dump', `append', and `restore' to copy data
+between target memory and a file. The `dump' and `append' commands
+write data to a file, and the `restore' command reads data from a file
+back into the inferior's memory. Files may be in binary, Motorola
+S-record, Intel hex, or Tektronix Hex format; however, GDB can only
+append to binary files.
+
+`dump [FORMAT] memory FILENAME START_ADDR END_ADDR'
+`dump [FORMAT] value FILENAME EXPR'
+ Dump the contents of memory from START_ADDR to END_ADDR, or the
+ value of EXPR, to FILENAME in the given format.
+
+ The FORMAT parameter may be any one of:
+ `binary'
+ Raw binary form.
+
+ `ihex'
+ Intel hex format.
+
+ `srec'
+ Motorola S-record format.
+
+ `tekhex'
+ Tektronix Hex format.
+
+ GDB uses the same definitions of these formats as the GNU binary
+ utilities, like `objdump' and `objcopy'. If FORMAT is omitted,
+ GDB dumps the data in raw binary form.
+
+`append [binary] memory FILENAME START_ADDR END_ADDR'
+`append [binary] value FILENAME EXPR'
+ Append the contents of memory from START_ADDR to END_ADDR, or the
+ value of EXPR, to the file FILENAME, in raw binary form. (GDB can
+ only append data to files in raw binary form.)
+
+`restore FILENAME [binary] BIAS START END'
+ Restore the contents of file FILENAME into memory. The `restore'
+ command can automatically recognize any known BFD file format,
+ except for raw binary. To restore a raw binary file you must
+ specify the optional keyword `binary' after the filename.
+
+ If BIAS is non-zero, its value will be added to the addresses
+ contained in the file. Binary files always start at address zero,
+ so they will be restored at address BIAS. Other bfd files have a
+ built-in location; they will be restored at offset BIAS from that
+ location.
+
+ If START and/or END are non-zero, then only data between file
+ offset START and file offset END will be restored. These offsets
+ are relative to the addresses in the file, before the BIAS
+ argument is applied.
+
+
+
+File: gdb.info, Node: Core File Generation, Next: Character Sets, Prev: Dump/Restore Files, Up: Data
+
+10.18 How to Produce a Core File from Your Program
+==================================================
+
+A "core file" or "core dump" is a file that records the memory image of
+a running process and its process status (register values etc.). Its
+primary use is post-mortem debugging of a program that crashed while it
+ran outside a debugger. A program that crashes automatically produces
+a core file, unless this feature is disabled by the user. *Note
+Files::, for information on invoking GDB in the post-mortem debugging
+mode.
+
+ Occasionally, you may wish to produce a core file of the program you
+are debugging in order to preserve a snapshot of its state. GDB has a
+special command for that.
+
+`generate-core-file [FILE]'
+`gcore [FILE]'
+ Produce a core dump of the inferior process. The optional argument
+ FILE specifies the file name where to put the core dump. If not
+ specified, the file name defaults to `core.PID', where PID is the
+ inferior process ID.
+
+ Note that this command is implemented only for some systems (as of
+ this writing, GNU/Linux, FreeBSD, Solaris, Unixware, and S390).
+
+
+File: gdb.info, Node: Character Sets, Next: Caching Remote Data, Prev: Core File Generation, Up: Data
+
+10.19 Character Sets
+====================
+
+If the program you are debugging uses a different character set to
+represent characters and strings than the one GDB uses itself, GDB can
+automatically translate between the character sets for you. The
+character set GDB uses we call the "host character set"; the one the
+inferior program uses we call the "target character set".
+
+ For example, if you are running GDB on a GNU/Linux system, which
+uses the ISO Latin 1 character set, but you are using GDB's remote
+protocol (*note Remote Debugging::) to debug a program running on an
+IBM mainframe, which uses the EBCDIC character set, then the host
+character set is Latin-1, and the target character set is EBCDIC. If
+you give GDB the command `set target-charset EBCDIC-US', then GDB
+translates between EBCDIC and Latin 1 as you print character or string
+values, or use character and string literals in expressions.
+
+ GDB has no way to automatically recognize which character set the
+inferior program uses; you must tell it, using the `set target-charset'
+command, described below.
+
+ Here are the commands for controlling GDB's character set support:
+
+`set target-charset CHARSET'
+ Set the current target character set to CHARSET. To display the
+ list of supported target character sets, type
+ `set target-charset <TAB><TAB>'.
+
+`set host-charset CHARSET'
+ Set the current host character set to CHARSET.
+
+ By default, GDB uses a host character set appropriate to the
+ system it is running on; you can override that default using the
+ `set host-charset' command. On some systems, GDB cannot
+ automatically determine the appropriate host character set. In
+ this case, GDB uses `UTF-8'.
+
+ GDB can only use certain character sets as its host character set.
+ If you type `set host-charset <TAB><TAB>', GDB will list the host
+ character sets it supports.
+
+`set charset CHARSET'
+ Set the current host and target character sets to CHARSET. As
+ above, if you type `set charset <TAB><TAB>', GDB will list the
+ names of the character sets that can be used for both host and
+ target.
+
+`show charset'
+ Show the names of the current host and target character sets.
+
+`show host-charset'
+ Show the name of the current host character set.
+
+`show target-charset'
+ Show the name of the current target character set.
+
+`set target-wide-charset CHARSET'
+ Set the current target's wide character set to CHARSET. This is
+ the character set used by the target's `wchar_t' type. To display
+ the list of supported wide character sets, type
+ `set target-wide-charset <TAB><TAB>'.
+
+`show target-wide-charset'
+ Show the name of the current target's wide character set.
+
+ Here is an example of GDB's character set support in action. Assume
+that the following source code has been placed in the file
+`charset-test.c':
+
+ #include <stdio.h>
+
+ char ascii_hello[]
+ = {72, 101, 108, 108, 111, 44, 32, 119,
+ 111, 114, 108, 100, 33, 10, 0};
+ char ibm1047_hello[]
+ = {200, 133, 147, 147, 150, 107, 64, 166,
+ 150, 153, 147, 132, 90, 37, 0};
+
+ main ()
+ {
+ printf ("Hello, world!\n");
+ }
+
+ In this program, `ascii_hello' and `ibm1047_hello' are arrays
+containing the string `Hello, world!' followed by a newline, encoded in
+the ASCII and IBM1047 character sets.
+
+ We compile the program, and invoke the debugger on it:
+
+ $ gcc -g charset-test.c -o charset-test
+ $ gdb -nw charset-test
+ GNU gdb 2001-12-19-cvs
+ Copyright 2001 Free Software Foundation, Inc.
+ ...
+ (gdb)
+
+ We can use the `show charset' command to see what character sets GDB
+is currently using to interpret and display characters and strings:
+
+ (gdb) show charset
+ The current host and target character set is `ISO-8859-1'.
+ (gdb)
+
+ For the sake of printing this manual, let's use ASCII as our initial
+character set:
+ (gdb) set charset ASCII
+ (gdb) show charset
+ The current host and target character set is `ASCII'.
+ (gdb)
+
+ Let's assume that ASCII is indeed the correct character set for our
+host system -- in other words, let's assume that if GDB prints
+characters using the ASCII character set, our terminal will display
+them properly. Since our current target character set is also ASCII,
+the contents of `ascii_hello' print legibly:
+
+ (gdb) print ascii_hello
+ $1 = 0x401698 "Hello, world!\n"
+ (gdb) print ascii_hello[0]
+ $2 = 72 'H'
+ (gdb)
+
+ GDB uses the target character set for character and string literals
+you use in expressions:
+
+ (gdb) print '+'
+ $3 = 43 '+'
+ (gdb)
+
+ The ASCII character set uses the number 43 to encode the `+'
+character.
+
+ GDB relies on the user to tell it which character set the target
+program uses. If we print `ibm1047_hello' while our target character
+set is still ASCII, we get jibberish:
+
+ (gdb) print ibm1047_hello
+ $4 = 0x4016a8 "\310\205\223\223\226k@\246\226\231\223\204Z%"
+ (gdb) print ibm1047_hello[0]
+ $5 = 200 '\310'
+ (gdb)
+
+ If we invoke the `set target-charset' followed by <TAB><TAB>, GDB
+tells us the character sets it supports:
+
+ (gdb) set target-charset
+ ASCII EBCDIC-US IBM1047 ISO-8859-1
+ (gdb) set target-charset
+
+ We can select IBM1047 as our target character set, and examine the
+program's strings again. Now the ASCII string is wrong, but GDB
+translates the contents of `ibm1047_hello' from the target character
+set, IBM1047, to the host character set, ASCII, and they display
+correctly:
+
+ (gdb) set target-charset IBM1047
+ (gdb) show charset
+ The current host character set is `ASCII'.
+ The current target character set is `IBM1047'.
+ (gdb) print ascii_hello
+ $6 = 0x401698 "\110\145%%?\054\040\167?\162%\144\041\012"
+ (gdb) print ascii_hello[0]
+ $7 = 72 '\110'
+ (gdb) print ibm1047_hello
+ $8 = 0x4016a8 "Hello, world!\n"
+ (gdb) print ibm1047_hello[0]
+ $9 = 200 'H'
+ (gdb)
+
+ As above, GDB uses the target character set for character and string
+literals you use in expressions:
+
+ (gdb) print '+'
+ $10 = 78 '+'
+ (gdb)
+
+ The IBM1047 character set uses the number 78 to encode the `+'
+character.
+
+
+File: gdb.info, Node: Caching Remote Data, Next: Searching Memory, Prev: Character Sets, Up: Data
+
+10.20 Caching Data of Remote Targets
+====================================
+
+GDB caches data exchanged between the debugger and a remote target
+(*note Remote Debugging::). Such caching generally improves
+performance, because it reduces the overhead of the remote protocol by
+bundling memory reads and writes into large chunks. Unfortunately,
+simply caching everything would lead to incorrect results, since GDB
+does not necessarily know anything about volatile values, memory-mapped
+I/O addresses, etc. Furthermore, in non-stop mode (*note Non-Stop
+Mode::) memory can be changed _while_ a gdb command is executing.
+Therefore, by default, GDB only caches data known to be on the stack(1).
+Other regions of memory can be explicitly marked as cacheable; see
+*note Memory Region Attributes::.
+
+`set remotecache on'
+`set remotecache off'
+ This option no longer does anything; it exists for compatibility
+ with old scripts.
+
+`show remotecache'
+ Show the current state of the obsolete remotecache flag.
+
+`set stack-cache on'
+`set stack-cache off'
+ Enable or disable caching of stack accesses. When `ON', use
+ caching. By default, this option is `ON'.
+
+`show stack-cache'
+ Show the current state of data caching for memory accesses.
+
+`info dcache [line]'
+ Print the information about the data cache performance. The
+ information displayed includes the dcache width and depth, and for
+ each cache line, its number, address, and how many times it was
+ referenced. This command is useful for debugging the data cache
+ operation.
+
+ If a line number is specified, the contents of that line will be
+ printed in hex.
+
+`set dcache size SIZE'
+ Set maximum number of entries in dcache (dcache depth above).
+
+`set dcache line-size LINE-SIZE'
+ Set number of bytes each dcache entry caches (dcache width above).
+ Must be a power of 2.
+
+`show dcache size'
+ Show maximum number of dcache entries. See also *Note info
+ dcache: Caching Remote Data.
+
+`show dcache line-size'
+ Show default size of dcache lines. See also *Note info dcache:
+ Caching Remote Data.
+
+
+ ---------- Footnotes ----------
+
+ (1) In non-stop mode, it is moderately rare for a running thread to
+modify the stack of a stopped thread in a way that would interfere with
+a backtrace, and caching of stack reads provides a significant speed up
+of remote backtraces.
+
+
+File: gdb.info, Node: Searching Memory, Prev: Caching Remote Data, Up: Data
+
+10.21 Search Memory
+===================
+
+Memory can be searched for a particular sequence of bytes with the
+`find' command.
+
+`find [/SN] START_ADDR, +LEN, VAL1 [, VAL2, ...]'
+`find [/SN] START_ADDR, END_ADDR, VAL1 [, VAL2, ...]'
+ Search memory for the sequence of bytes specified by VAL1, VAL2,
+ etc. The search begins at address START_ADDR and continues for
+ either LEN bytes or through to END_ADDR inclusive.
+
+ S and N are optional parameters. They may be specified in either
+order, apart or together.
+
+S, search query size
+ The size of each search query value.
+
+ `b'
+ bytes
+
+ `h'
+ halfwords (two bytes)
+
+ `w'
+ words (four bytes)
+
+ `g'
+ giant words (eight bytes)
+
+ All values are interpreted in the current language. This means,
+ for example, that if the current source language is C/C++ then
+ searching for the string "hello" includes the trailing '\0'.
+
+ If the value size is not specified, it is taken from the value's
+ type in the current language. This is useful when one wants to
+ specify the search pattern as a mixture of types. Note that this
+ means, for example, that in the case of C-like languages a search
+ for an untyped 0x42 will search for `(int) 0x42' which is
+ typically four bytes.
+
+N, maximum number of finds
+ The maximum number of matches to print. The default is to print
+ all finds.
+
+ You can use strings as search values. Quote them with double-quotes
+(`"'). The string value is copied into the search pattern byte by
+byte, regardless of the endianness of the target and the size
+specification.
+
+ The address of each match found is printed as well as a count of the
+number of matches found.
+
+ The address of the last value found is stored in convenience variable
+`$_'. A count of the number of matches is stored in `$numfound'.
+
+ For example, if stopped at the `printf' in this function:
+
+ void
+ hello ()
+ {
+ static char hello[] = "hello-hello";
+ static struct { char c; short s; int i; }
+ __attribute__ ((packed)) mixed
+ = { 'c', 0x1234, 0x87654321 };
+ printf ("%s\n", hello);
+ }
+
+you get during debugging:
+
+ (gdb) find &hello[0], +sizeof(hello), "hello"
+ 0x804956d <hello.1620+6>
+ 1 pattern found
+ (gdb) find &hello[0], +sizeof(hello), 'h', 'e', 'l', 'l', 'o'
+ 0x8049567 <hello.1620>
+ 0x804956d <hello.1620+6>
+ 2 patterns found
+ (gdb) find /b1 &hello[0], +sizeof(hello), 'h', 0x65, 'l'
+ 0x8049567 <hello.1620>
+ 1 pattern found
+ (gdb) find &mixed, +sizeof(mixed), (char) 'c', (short) 0x1234, (int) 0x87654321
+ 0x8049560 <mixed.1625>
+ 1 pattern found
+ (gdb) print $numfound
+ $1 = 1
+ (gdb) print $_
+ $2 = (void *) 0x8049560
+
+
+File: gdb.info, Node: Optimized Code, Next: Macros, Prev: Data, Up: Top
+
+11 Debugging Optimized Code
+***************************
+
+Almost all compilers support optimization. With optimization disabled,
+the compiler generates assembly code that corresponds directly to your
+source code, in a simplistic way. As the compiler applies more
+powerful optimizations, the generated assembly code diverges from your
+original source code. With help from debugging information generated
+by the compiler, GDB can map from the running program back to
+constructs from your original source.
+
+ GDB is more accurate with optimization disabled. If you can
+recompile without optimization, it is easier to follow the progress of
+your program during debugging. But, there are many cases where you may
+need to debug an optimized version.
+
+ When you debug a program compiled with `-g -O', remember that the
+optimizer has rearranged your code; the debugger shows you what is
+really there. Do not be too surprised when the execution path does not
+exactly match your source file! An extreme example: if you define a
+variable, but never use it, GDB never sees that variable--because the
+compiler optimizes it out of existence.
+
+ Some things do not work as well with `-g -O' as with just `-g',
+particularly on machines with instruction scheduling. If in doubt,
+recompile with `-g' alone, and if this fixes the problem, please report
+it to us as a bug (including a test case!). *Note Variables::, for
+more information about debugging optimized code.
+
+* Menu:
+
+* Inline Functions:: How GDB presents inlining
+* Tail Call Frames:: GDB analysis of jumps to functions
+
+
+File: gdb.info, Node: Inline Functions, Next: Tail Call Frames, Up: Optimized Code
+
+11.1 Inline Functions
+=====================
+
+"Inlining" is an optimization that inserts a copy of the function body
+directly at each call site, instead of jumping to a shared routine.
+GDB displays inlined functions just like non-inlined functions. They
+appear in backtraces. You can view their arguments and local
+variables, step into them with `step', skip them with `next', and
+escape from them with `finish'. You can check whether a function was
+inlined by using the `info frame' command.
+
+ For GDB to support inlined functions, the compiler must record
+information about inlining in the debug information -- GCC using the
+DWARF 2 format does this, and several other compilers do also. GDB
+only supports inlined functions when using DWARF 2. Versions of GCC
+before 4.1 do not emit two required attributes (`DW_AT_call_file' and
+`DW_AT_call_line'); GDB does not display inlined function calls with
+earlier versions of GCC. It instead displays the arguments and local
+variables of inlined functions as local variables in the caller.
+
+ The body of an inlined function is directly included at its call
+site; unlike a non-inlined function, there are no instructions devoted
+to the call. GDB still pretends that the call site and the start of
+the inlined function are different instructions. Stepping to the call
+site shows the call site, and then stepping again shows the first line
+of the inlined function, even though no additional instructions are
+executed.
+
+ This makes source-level debugging much clearer; you can see both the
+context of the call and then the effect of the call. Only stepping by
+a single instruction using `stepi' or `nexti' does not do this; single
+instruction steps always show the inlined body.
+
+ There are some ways that GDB does not pretend that inlined function
+calls are the same as normal calls:
+
+ * You cannot set breakpoints on inlined functions. GDB either
+ reports that there is no symbol with that name, or else sets the
+ breakpoint only on non-inlined copies of the function. This
+ limitation will be removed in a future version of GDB; until then,
+ set a breakpoint by line number on the first line of the inlined
+ function instead.
+
+ * Setting breakpoints at the call site of an inlined function may not
+ work, because the call site does not contain any code. GDB may
+ incorrectly move the breakpoint to the next line of the enclosing
+ function, after the call. This limitation will be removed in a
+ future version of GDB; until then, set a breakpoint on an earlier
+ line or inside the inlined function instead.
+
+ * GDB cannot locate the return value of inlined calls after using
+ the `finish' command. This is a limitation of compiler-generated
+ debugging information; after `finish', you can step to the next
+ line and print a variable where your program stored the return
+ value.
+
+
+
+File: gdb.info, Node: Tail Call Frames, Prev: Inline Functions, Up: Optimized Code
+
+11.2 Tail Call Frames
+=====================
+
+Function `B' can call function `C' in its very last statement. In
+unoptimized compilation the call of `C' is immediately followed by
+return instruction at the end of `B' code. Optimizing compiler may
+replace the call and return in function `B' into one jump to function
+`C' instead. Such use of a jump instruction is called "tail call".
+
+ During execution of function `C', there will be no indication in the
+function call stack frames that it was tail-called from `B'. If
+function `A' regularly calls function `B' which tail-calls function `C',
+then GDB will see `A' as the caller of `C'. However, in some cases GDB
+can determine that `C' was tail-called from `B', and it will then
+create fictitious call frame for that, with the return address set up
+as if `B' called `C' normally.
+
+ This functionality is currently supported only by DWARF 2 debugging
+format and the compiler has to produce `DW_TAG_GNU_call_site' tags.
+With GCC, you need to specify `-O -g' during compilation, to get this
+information.
+
+ `info frame' command (*note Frame Info::) will indicate the tail
+call frame kind by text `tail call frame' such as in this sample GDB
+output:
+
+ (gdb) x/i $pc - 2
+ 0x40066b <b(int, double)+11>: jmp 0x400640 <c(int, double)>
+ (gdb) info frame
+ Stack level 1, frame at 0x7fffffffda30:
+ rip = 0x40066d in b (amd64-entry-value.cc:59); saved rip 0x4004c5
+ tail call frame, caller of frame at 0x7fffffffda30
+ source language c++.
+ Arglist at unknown address.
+ Locals at unknown address, Previous frame's sp is 0x7fffffffda30
+
+ The detection of all the possible code path executions can find them
+ambiguous. There is no execution history stored (possible *Note
+Reverse Execution:: is never used for this purpose) and the last known
+caller could have reached the known callee by multiple different jump
+sequences. In such case GDB still tries to show at least all the
+unambiguous top tail callers and all the unambiguous bottom tail
+calees, if any.
+
+`set debug entry-values'
+ When set to on, enables printing of analysis messages for both
+ frame argument values at function entry and tail calls. It will
+ show all the possible valid tail calls code paths it has
+ considered. It will also print the intersection of them with the
+ final unambiguous (possibly partial or even empty) code path
+ result.
+
+`show debug entry-values'
+ Show the current state of analysis messages printing for both
+ frame argument values at function entry and tail calls.
+
+ The analysis messages for tail calls can for example show why the
+virtual tail call frame for function `c' has not been recognized (due
+to the indirect reference by variable `x'):
+
+ static void __attribute__((noinline, noclone)) c (void);
+ void (*x) (void) = c;
+ static void __attribute__((noinline, noclone)) a (void) { x++; }
+ static void __attribute__((noinline, noclone)) c (void) { a (); }
+ int main (void) { x (); return 0; }
+
+ Breakpoint 1, DW_OP_GNU_entry_value resolving cannot find
+ DW_TAG_GNU_call_site 0x40039a in main
+ a () at t.c:3
+ 3 static void __attribute__((noinline, noclone)) a (void) { x++; }
+ (gdb) bt
+ #0 a () at t.c:3
+ #1 0x000000000040039a in main () at t.c:5
+
+ Another possibility is an ambiguous virtual tail call frames
+resolution:
+
+ int i;
+ static void __attribute__((noinline, noclone)) f (void) { i++; }
+ static void __attribute__((noinline, noclone)) e (void) { f (); }
+ static void __attribute__((noinline, noclone)) d (void) { f (); }
+ static void __attribute__((noinline, noclone)) c (void) { d (); }
+ static void __attribute__((noinline, noclone)) b (void)
+ { if (i) c (); else e (); }
+ static void __attribute__((noinline, noclone)) a (void) { b (); }
+ int main (void) { a (); return 0; }
+
+ tailcall: initial: 0x4004d2(a) 0x4004ce(b) 0x4004b2(c) 0x4004a2(d)
+ tailcall: compare: 0x4004d2(a) 0x4004cc(b) 0x400492(e)
+ tailcall: reduced: 0x4004d2(a) |
+ (gdb) bt
+ #0 f () at t.c:2
+ #1 0x00000000004004d2 in a () at t.c:8
+ #2 0x0000000000400395 in main () at t.c:9
+
+ Frames #0 and #2 are real, #1 is a virtual tail call frame. The
+code can have possible execution paths `main->a->b->c->d->f' or
+`main->a->b->e->f', GDB cannot find which one from the inferior state.
+
+ `initial:' state shows some random possible calling sequence GDB has
+found. It then finds another possible calling sequcen - that one is
+prefixed by `compare:'. The non-ambiguous intersection of these two is
+printed as the `reduced:' calling sequence. That one could have many
+futher `compare:' and `reduced:' statements as long as there remain any
+non-ambiguous sequence entries.
+
+ For the frame of function `b' in both cases there are different
+possible `$pc' values (`0x4004cc' or `0x4004ce'), therefore this frame
+is also ambigous. The only non-ambiguous frame is the one for function
+`a', therefore this one is displayed to the user while the ambiguous
+frames are omitted.
+
+ There can be also reasons why printing of frame argument values at
+function entry may fail:
+
+ int v;
+ static void __attribute__((noinline, noclone)) c (int i) { v++; }
+ static void __attribute__((noinline, noclone)) a (int i);
+ static void __attribute__((noinline, noclone)) b (int i) { a (i); }
+ static void __attribute__((noinline, noclone)) a (int i)
+ { if (i) b (i - 1); else c (0); }
+ int main (void) { a (5); return 0; }
+
+ (gdb) bt
+ #0 c (i=i@entry=0) at t.c:2
+ #1 0x0000000000400428 in a (DW_OP_GNU_entry_value resolving has found
+ function "a" at 0x400420 can call itself via tail calls
+ i=<optimized out>) at t.c:6
+ #2 0x000000000040036e in main () at t.c:7
+
+ GDB cannot find out from the inferior state if and how many times did
+function `a' call itself (via function `b') as these calls would be
+tail calls. Such tail calls would modify thue `i' variable, therefore
+GDB cannot be sure the value it knows would be right - GDB prints
+`<optimized out>' instead.
+
+
+File: gdb.info, Node: Macros, Next: Tracepoints, Prev: Optimized Code, Up: Top
+
+12 C Preprocessor Macros
+************************
+
+Some languages, such as C and C++, provide a way to define and invoke
+"preprocessor macros" which expand into strings of tokens. GDB can
+evaluate expressions containing macro invocations, show the result of
+macro expansion, and show a macro's definition, including where it was
+defined.
+
+ You may need to compile your program specially to provide GDB with
+information about preprocessor macros. Most compilers do not include
+macros in their debugging information, even when you compile with the
+`-g' flag. *Note Compilation::.
+
+ A program may define a macro at one point, remove that definition
+later, and then provide a different definition after that. Thus, at
+different points in the program, a macro may have different
+definitions, or have no definition at all. If there is a current stack
+frame, GDB uses the macros in scope at that frame's source code line.
+Otherwise, GDB uses the macros in scope at the current listing location;
+see *Note List::.
+
+ Whenever GDB evaluates an expression, it always expands any macro
+invocations present in the expression. GDB also provides the following
+commands for working with macros explicitly.
+
+`macro expand EXPRESSION'
+`macro exp EXPRESSION'
+ Show the results of expanding all preprocessor macro invocations in
+ EXPRESSION. Since GDB simply expands macros, but does not parse
+ the result, EXPRESSION need not be a valid expression; it can be
+ any string of tokens.
+
+`macro expand-once EXPRESSION'
+`macro exp1 EXPRESSION'
+ (This command is not yet implemented.) Show the results of
+ expanding those preprocessor macro invocations that appear
+ explicitly in EXPRESSION. Macro invocations appearing in that
+ expansion are left unchanged. This command allows you to see the
+ effect of a particular macro more clearly, without being confused
+ by further expansions. Since GDB simply expands macros, but does
+ not parse the result, EXPRESSION need not be a valid expression; it
+ can be any string of tokens.
+
+`info macro [-a|-all] [--] MACRO'
+ Show the current definition or all definitions of the named MACRO,
+ and describe the source location or compiler command-line where
+ that definition was established. The optional double dash is to
+ signify the end of argument processing and the beginning of MACRO
+ for non C-like macros where the macro may begin with a hyphen.
+
+`info macros LINESPEC'
+ Show all macro definitions that are in effect at the location
+ specified by LINESPEC, and describe the source location or
+ compiler command-line where those definitions were established.
+
+`macro define MACRO REPLACEMENT-LIST'
+`macro define MACRO(ARGLIST) REPLACEMENT-LIST'
+ Introduce a definition for a preprocessor macro named MACRO,
+ invocations of which are replaced by the tokens given in
+ REPLACEMENT-LIST. The first form of this command defines an
+ "object-like" macro, which takes no arguments; the second form
+ defines a "function-like" macro, which takes the arguments given in
+ ARGLIST.
+
+ A definition introduced by this command is in scope in every
+ expression evaluated in GDB, until it is removed with the `macro
+ undef' command, described below. The definition overrides all
+ definitions for MACRO present in the program being debugged, as
+ well as any previous user-supplied definition.
+
+`macro undef MACRO'
+ Remove any user-supplied definition for the macro named MACRO.
+ This command only affects definitions provided with the `macro
+ define' command, described above; it cannot remove definitions
+ present in the program being debugged.
+
+`macro list'
+ List all the macros defined using the `macro define' command.
+
+ Here is a transcript showing the above commands in action. First, we
+show our source files:
+
+ $ cat sample.c
+ #include <stdio.h>
+ #include "sample.h"
+
+ #define M 42
+ #define ADD(x) (M + x)
+
+ main ()
+ {
+ #define N 28
+ printf ("Hello, world!\n");
+ #undef N
+ printf ("We're so creative.\n");
+ #define N 1729
+ printf ("Goodbye, world!\n");
+ }
+ $ cat sample.h
+ #define Q <
+ $
+
+ Now, we compile the program using the GNU C compiler, GCC. We pass
+the `-gdwarf-2'(1) _and_ `-g3' flags to ensure the compiler includes
+information about preprocessor macros in the debugging information.
+
+ $ gcc -gdwarf-2 -g3 sample.c -o sample
+ $
+
+ Now, we start GDB on our sample program:
+
+ $ gdb -nw sample
+ GNU gdb 2002-05-06-cvs
+ Copyright 2002 Free Software Foundation, Inc.
+ GDB is free software, ...
+ (gdb)
+
+ We can expand macros and examine their definitions, even when the
+program is not running. GDB uses the current listing position to
+decide which macro definitions are in scope:
+
+ (gdb) list main
+ 3
+ 4 #define M 42
+ 5 #define ADD(x) (M + x)
+ 6
+ 7 main ()
+ 8 {
+ 9 #define N 28
+ 10 printf ("Hello, world!\n");
+ 11 #undef N
+ 12 printf ("We're so creative.\n");
+ (gdb) info macro ADD
+ Defined at /home/jimb/gdb/macros/play/sample.c:5
+ #define ADD(x) (M + x)
+ (gdb) info macro Q
+ Defined at /home/jimb/gdb/macros/play/sample.h:1
+ included at /home/jimb/gdb/macros/play/sample.c:2
+ #define Q <
+ (gdb) macro expand ADD(1)
+ expands to: (42 + 1)
+ (gdb) macro expand-once ADD(1)
+ expands to: once (M + 1)
+ (gdb)
+
+ In the example above, note that `macro expand-once' expands only the
+macro invocation explicit in the original text -- the invocation of
+`ADD' -- but does not expand the invocation of the macro `M', which was
+introduced by `ADD'.
+
+ Once the program is running, GDB uses the macro definitions in force
+at the source line of the current stack frame:
+
+ (gdb) break main
+ Breakpoint 1 at 0x8048370: file sample.c, line 10.
+ (gdb) run
+ Starting program: /home/jimb/gdb/macros/play/sample
+
+ Breakpoint 1, main () at sample.c:10
+ 10 printf ("Hello, world!\n");
+ (gdb)
+
+ At line 10, the definition of the macro `N' at line 9 is in force:
+
+ (gdb) info macro N
+ Defined at /home/jimb/gdb/macros/play/sample.c:9
+ #define N 28
+ (gdb) macro expand N Q M
+ expands to: 28 < 42
+ (gdb) print N Q M
+ $1 = 1
+ (gdb)
+
+ As we step over directives that remove `N''s definition, and then
+give it a new definition, GDB finds the definition (or lack thereof) in
+force at each point:
+
+ (gdb) next
+ Hello, world!
+ 12 printf ("We're so creative.\n");
+ (gdb) info macro N
+ The symbol `N' has no definition as a C/C++ preprocessor macro
+ at /home/jimb/gdb/macros/play/sample.c:12
+ (gdb) next
+ We're so creative.
+ 14 printf ("Goodbye, world!\n");
+ (gdb) info macro N
+ Defined at /home/jimb/gdb/macros/play/sample.c:13
+ #define N 1729
+ (gdb) macro expand N Q M
+ expands to: 1729 < 42
+ (gdb) print N Q M
+ $2 = 0
+ (gdb)
+
+ In addition to source files, macros can be defined on the
+compilation command line using the `-DNAME=VALUE' syntax. For macros
+defined in such a way, GDB displays the location of their definition as
+line zero of the source file submitted to the compiler.
+
+ (gdb) info macro __STDC__
+ Defined at /home/jimb/gdb/macros/play/sample.c:0
+ -D__STDC__=1
+ (gdb)
+
+ ---------- Footnotes ----------
+
+ (1) This is the minimum. Recent versions of GCC support `-gdwarf-3'
+and `-gdwarf-4'; we recommend always choosing the most recent version
+of DWARF.
+
+
+File: gdb.info, Node: Tracepoints, Next: Overlays, Prev: Macros, Up: Top
+
+13 Tracepoints
+**************
+
+In some applications, it is not feasible for the debugger to interrupt
+the program's execution long enough for the developer to learn anything
+helpful about its behavior. If the program's correctness depends on
+its real-time behavior, delays introduced by a debugger might cause the
+program to change its behavior drastically, or perhaps fail, even when
+the code itself is correct. It is useful to be able to observe the
+program's behavior without interrupting it.
+
+ Using GDB's `trace' and `collect' commands, you can specify
+locations in the program, called "tracepoints", and arbitrary
+expressions to evaluate when those tracepoints are reached. Later,
+using the `tfind' command, you can examine the values those expressions
+had when the program hit the tracepoints. The expressions may also
+denote objects in memory--structures or arrays, for example--whose
+values GDB should record; while visiting a particular tracepoint, you
+may inspect those objects as if they were in memory at that moment.
+However, because GDB records these values without interacting with you,
+it can do so quickly and unobtrusively, hopefully not disturbing the
+program's behavior.
+
+ The tracepoint facility is currently available only for remote
+targets. *Note Targets::. In addition, your remote target must know
+how to collect trace data. This functionality is implemented in the
+remote stub; however, none of the stubs distributed with GDB support
+tracepoints as of this writing. The format of the remote packets used
+to implement tracepoints are described in *Note Tracepoint Packets::.
+
+ It is also possible to get trace data from a file, in a manner
+reminiscent of corefiles; you specify the filename, and use `tfind' to
+search through the file. *Note Trace Files::, for more details.
+
+ This chapter describes the tracepoint commands and features.
+
+* Menu:
+
+* Set Tracepoints::
+* Analyze Collected Data::
+* Tracepoint Variables::
+* Trace Files::
+
+
+File: gdb.info, Node: Set Tracepoints, Next: Analyze Collected Data, Up: Tracepoints
+
+13.1 Commands to Set Tracepoints
+================================
+
+Before running such a "trace experiment", an arbitrary number of
+tracepoints can be set. A tracepoint is actually a special type of
+breakpoint (*note Set Breaks::), so you can manipulate it using
+standard breakpoint commands. For instance, as with breakpoints,
+tracepoint numbers are successive integers starting from one, and many
+of the commands associated with tracepoints take the tracepoint number
+as their argument, to identify which tracepoint to work on.
+
+ For each tracepoint, you can specify, in advance, some arbitrary set
+of data that you want the target to collect in the trace buffer when it
+hits that tracepoint. The collected data can include registers, local
+variables, or global data. Later, you can use GDB commands to examine
+the values these data had at the time the tracepoint was hit.
+
+ Tracepoints do not support every breakpoint feature. Ignore counts
+on tracepoints have no effect, and tracepoints cannot run GDB commands
+when they are hit. Tracepoints may not be thread-specific either.
+
+ Some targets may support "fast tracepoints", which are inserted in a
+different way (such as with a jump instead of a trap), that is faster
+but possibly restricted in where they may be installed.
+
+ Regular and fast tracepoints are dynamic tracing facilities, meaning
+that they can be used to insert tracepoints at (almost) any location in
+the target. Some targets may also support controlling "static
+tracepoints" from GDB. With static tracing, a set of instrumentation
+points, also known as "markers", are embedded in the target program,
+and can be activated or deactivated by name or address. These are
+usually placed at locations which facilitate investigating what the
+target is actually doing. GDB's support for static tracing includes
+being able to list instrumentation points, and attach them with GDB
+defined high level tracepoints that expose the whole range of
+convenience of GDB's tracepoints support. Namely, support for
+collecting registers values and values of global or local (to the
+instrumentation point) variables; tracepoint conditions and trace state
+variables. The act of installing a GDB static tracepoint on an
+instrumentation point, or marker, is referred to as "probing" a static
+tracepoint marker.
+
+ `gdbserver' supports tracepoints on some target systems. *Note
+Tracepoints support in `gdbserver': Server.
+
+ This section describes commands to set tracepoints and associated
+conditions and actions.
+
+* Menu:
+
+* Create and Delete Tracepoints::
+* Enable and Disable Tracepoints::
+* Tracepoint Passcounts::
+* Tracepoint Conditions::
+* Trace State Variables::
+* Tracepoint Actions::
+* Listing Tracepoints::
+* Listing Static Tracepoint Markers::
+* Starting and Stopping Trace Experiments::
+* Tracepoint Restrictions::
+
+
+File: gdb.info, Node: Create and Delete Tracepoints, Next: Enable and Disable Tracepoints, Up: Set Tracepoints
+
+13.1.1 Create and Delete Tracepoints
+------------------------------------
+
+`trace LOCATION'
+ The `trace' command is very similar to the `break' command. Its
+ argument LOCATION can be a source line, a function name, or an
+ address in the target program. *Note Specify Location::. The
+ `trace' command defines a tracepoint, which is a point in the
+ target program where the debugger will briefly stop, collect some
+ data, and then allow the program to continue. Setting a
+ tracepoint or changing its actions takes effect immediately if the
+ remote stub supports the `InstallInTrace' feature (*note install
+ tracepoint in tracing::). If remote stub doesn't support the
+ `InstallInTrace' feature, all these changes don't take effect
+ until the next `tstart' command, and once a trace experiment is
+ running, further changes will not have any effect until the next
+ trace experiment starts. In addition, GDB supports "pending
+ tracepoints"--tracepoints whose address is not yet resolved.
+ (This is similar to pending breakpoints.) Pending tracepoints are
+ not downloaded to the target and not installed until they are
+ resolved. The resolution of pending tracepoints requires GDB
+ support--when debugging with the remote target, and GDB
+ disconnects from the remote stub (*note disconnected tracing::),
+ pending tracepoints can not be resolved (and downloaded to the
+ remote stub) while GDB is disconnected.
+
+ Here are some examples of using the `trace' command:
+
+ (gdb) trace foo.c:121 // a source file and line number
+
+ (gdb) trace +2 // 2 lines forward
+
+ (gdb) trace my_function // first source line of function
+
+ (gdb) trace *my_function // EXACT start address of function
+
+ (gdb) trace *0x2117c4 // an address
+
+ You can abbreviate `trace' as `tr'.
+
+`trace LOCATION if COND'
+ Set a tracepoint with condition COND; evaluate the expression COND
+ each time the tracepoint is reached, and collect data only if the
+ value is nonzero--that is, if COND evaluates as true. *Note
+ Tracepoint Conditions: Tracepoint Conditions, for more information
+ on tracepoint conditions.
+
+`ftrace LOCATION [ if COND ]'
+ The `ftrace' command sets a fast tracepoint. For targets that
+ support them, fast tracepoints will use a more efficient but
+ possibly less general technique to trigger data collection, such
+ as a jump instruction instead of a trap, or some sort of hardware
+ support. It may not be possible to create a fast tracepoint at
+ the desired location, in which case the command will exit with an
+ explanatory message.
+
+ GDB handles arguments to `ftrace' exactly as for `trace'.
+
+ On 32-bit x86-architecture systems, fast tracepoints normally need
+ to be placed at an instruction that is 5 bytes or longer, but can
+ be placed at 4-byte instructions if the low 64K of memory of the
+ target program is available to install trampolines. Some
+ Unix-type systems, such as GNU/Linux, exclude low addresses from
+ the program's address space; but for instance with the Linux
+ kernel it is possible to let GDB use this area by doing a `sysctl'
+ command to set the `mmap_min_addr' kernel parameter, as in
+
+ sudo sysctl -w vm.mmap_min_addr=32768
+
+ which sets the low address to 32K, which leaves plenty of room for
+ trampolines. The minimum address should be set to a page boundary.
+
+`strace LOCATION [ if COND ]'
+ The `strace' command sets a static tracepoint. For targets that
+ support it, setting a static tracepoint probes a static
+ instrumentation point, or marker, found at LOCATION. It may not
+ be possible to set a static tracepoint at the desired location, in
+ which case the command will exit with an explanatory message.
+
+ GDB handles arguments to `strace' exactly as for `trace', with the
+ addition that the user can also specify `-m MARKER' as LOCATION.
+ This probes the marker identified by the MARKER string identifier.
+ This identifier depends on the static tracepoint backend library
+ your program is using. You can find all the marker identifiers in
+ the `ID' field of the `info static-tracepoint-markers' command
+ output. *Note Listing Static Tracepoint Markers: Listing Static
+ Tracepoint Markers. For example, in the following small program
+ using the UST tracing engine:
+
+ main ()
+ {
+ trace_mark(ust, bar33, "str %s", "FOOBAZ");
+ }
+
+ the marker id is composed of joining the first two arguments to the
+ `trace_mark' call with a slash, which translates to:
+
+ (gdb) info static-tracepoint-markers
+ Cnt Enb ID Address What
+ 1 n ust/bar33 0x0000000000400ddc in main at stexample.c:22
+ Data: "str %s"
+ [etc...]
+
+ so you may probe the marker above with:
+
+ (gdb) strace -m ust/bar33
+
+ Static tracepoints accept an extra collect action -- `collect
+ $_sdata'. This collects arbitrary user data passed in the probe
+ point call to the tracing library. In the UST example above,
+ you'll see that the third argument to `trace_mark' is a
+ printf-like format string. The user data is then the result of
+ running that formating string against the following arguments.
+ Note that `info static-tracepoint-markers' command output lists
+ that format string in the `Data:' field.
+
+ You can inspect this data when analyzing the trace buffer, by
+ printing the $_sdata variable like any other variable available to
+ GDB. *Note Tracepoint Action Lists: Tracepoint Actions.
+
+ The convenience variable `$tpnum' records the tracepoint number of
+ the most recently set tracepoint.
+
+`delete tracepoint [NUM]'
+ Permanently delete one or more tracepoints. With no argument, the
+ default is to delete all tracepoints. Note that the regular
+ `delete' command can remove tracepoints also.
+
+ Examples:
+
+ (gdb) delete trace 1 2 3 // remove three tracepoints
+
+ (gdb) delete trace // remove all tracepoints
+
+ You can abbreviate this command as `del tr'.
+
+
+File: gdb.info, Node: Enable and Disable Tracepoints, Next: Tracepoint Passcounts, Prev: Create and Delete Tracepoints, Up: Set Tracepoints
+
+13.1.2 Enable and Disable Tracepoints
+-------------------------------------
+
+These commands are deprecated; they are equivalent to plain `disable'
+and `enable'.
+
+`disable tracepoint [NUM]'
+ Disable tracepoint NUM, or all tracepoints if no argument NUM is
+ given. A disabled tracepoint will have no effect during a trace
+ experiment, but it is not forgotten. You can re-enable a disabled
+ tracepoint using the `enable tracepoint' command. If the command
+ is issued during a trace experiment and the debug target has
+ support for disabling tracepoints during a trace experiment, then
+ the change will be effective immediately. Otherwise, it will be
+ applied to the next trace experiment.
+
+`enable tracepoint [NUM]'
+ Enable tracepoint NUM, or all tracepoints. If this command is
+ issued during a trace experiment and the debug target supports
+ enabling tracepoints during a trace experiment, then the enabled
+ tracepoints will become effective immediately. Otherwise, they
+ will become effective the next time a trace experiment is run.
+
+
+File: gdb.info, Node: Tracepoint Passcounts, Next: Tracepoint Conditions, Prev: Enable and Disable Tracepoints, Up: Set Tracepoints
+
+13.1.3 Tracepoint Passcounts
+----------------------------
+
+`passcount [N [NUM]]'
+ Set the "passcount" of a tracepoint. The passcount is a way to
+ automatically stop a trace experiment. If a tracepoint's
+ passcount is N, then the trace experiment will be automatically
+ stopped on the N'th time that tracepoint is hit. If the
+ tracepoint number NUM is not specified, the `passcount' command
+ sets the passcount of the most recently defined tracepoint. If no
+ passcount is given, the trace experiment will run until stopped
+ explicitly by the user.
+
+ Examples:
+
+ (gdb) passcount 5 2 // Stop on the 5th execution of
+ `// tracepoint 2'
+
+ (gdb) passcount 12 // Stop on the 12th execution of the
+ `// most recently defined tracepoint.'
+ (gdb) trace foo
+ (gdb) pass 3
+ (gdb) trace bar
+ (gdb) pass 2
+ (gdb) trace baz
+ (gdb) pass 1 // Stop tracing when foo has been
+ `// executed 3 times OR when bar has'
+ `// been executed 2 times'
+ `// OR when baz has been executed 1 time.'
+
+
+
+File: gdb.info, Node: Tracepoint Conditions, Next: Trace State Variables, Prev: Tracepoint Passcounts, Up: Set Tracepoints
+
+13.1.4 Tracepoint Conditions
+----------------------------
+
+The simplest sort of tracepoint collects data every time your program
+reaches a specified place. You can also specify a "condition" for a
+tracepoint. A condition is just a Boolean expression in your
+programming language (*note Expressions: Expressions.). A tracepoint
+with a condition evaluates the expression each time your program
+reaches it, and data collection happens only if the condition is true.
+
+ Tracepoint conditions can be specified when a tracepoint is set, by
+using `if' in the arguments to the `trace' command. *Note Setting
+Tracepoints: Create and Delete Tracepoints. They can also be set or
+changed at any time with the `condition' command, just as with
+breakpoints.
+
+ Unlike breakpoint conditions, GDB does not actually evaluate the
+conditional expression itself. Instead, GDB encodes the expression
+into an agent expression (*note Agent Expressions::) suitable for
+execution on the target, independently of GDB. Global variables become
+raw memory locations, locals become stack accesses, and so forth.
+
+ For instance, suppose you have a function that is usually called
+frequently, but should not be called after an error has occurred. You
+could use the following tracepoint command to collect data about calls
+of that function that happen while the error code is propagating
+through the program; an unconditional tracepoint could end up
+collecting thousands of useless trace frames that you would have to
+search through.
+
+ (gdb) trace normal_operation if errcode > 0
+
+
+File: gdb.info, Node: Trace State Variables, Next: Tracepoint Actions, Prev: Tracepoint Conditions, Up: Set Tracepoints
+
+13.1.5 Trace State Variables
+----------------------------
+
+A "trace state variable" is a special type of variable that is created
+and managed by target-side code. The syntax is the same as that for
+GDB's convenience variables (a string prefixed with "$"), but they are
+stored on the target. They must be created explicitly, using a
+`tvariable' command. They are always 64-bit signed integers.
+
+ Trace state variables are remembered by GDB, and downloaded to the
+target along with tracepoint information when the trace experiment
+starts. There are no intrinsic limits on the number of trace state
+variables, beyond memory limitations of the target.
+
+ Although trace state variables are managed by the target, you can use
+them in print commands and expressions as if they were convenience
+variables; GDB will get the current value from the target while the
+trace experiment is running. Trace state variables share the same
+namespace as other "$" variables, which means that you cannot have
+trace state variables with names like `$23' or `$pc', nor can you have
+a trace state variable and a convenience variable with the same name.
+
+`tvariable $NAME [ = EXPRESSION ]'
+ The `tvariable' command creates a new trace state variable named
+ `$NAME', and optionally gives it an initial value of EXPRESSION.
+ EXPRESSION is evaluated when this command is entered; the result
+ will be converted to an integer if possible, otherwise GDB will
+ report an error. A subsequent `tvariable' command specifying the
+ same name does not create a variable, but instead assigns the
+ supplied initial value to the existing variable of that name,
+ overwriting any previous initial value. The default initial value
+ is 0.
+
+`info tvariables'
+ List all the trace state variables along with their initial values.
+ Their current values may also be displayed, if the trace
+ experiment is currently running.
+
+`delete tvariable [ $NAME ... ]'
+ Delete the given trace state variables, or all of them if no
+ arguments are specified.
+
+
+
+File: gdb.info, Node: Tracepoint Actions, Next: Listing Tracepoints, Prev: Trace State Variables, Up: Set Tracepoints
+
+13.1.6 Tracepoint Action Lists
+------------------------------
+
+`actions [NUM]'
+ This command will prompt for a list of actions to be taken when the
+ tracepoint is hit. If the tracepoint number NUM is not specified,
+ this command sets the actions for the one that was most recently
+ defined (so that you can define a tracepoint and then say
+ `actions' without bothering about its number). You specify the
+ actions themselves on the following lines, one action at a time,
+ and terminate the actions list with a line containing just `end'.
+ So far, the only defined actions are `collect', `teval', and
+ `while-stepping'.
+
+ `actions' is actually equivalent to `commands' (*note Breakpoint
+ Command Lists: Break Commands.), except that only the defined
+ actions are allowed; any other GDB command is rejected.
+
+ To remove all actions from a tracepoint, type `actions NUM' and
+ follow it immediately with `end'.
+
+ (gdb) collect DATA // collect some data
+
+ (gdb) while-stepping 5 // single-step 5 times, collect data
+
+ (gdb) end // signals the end of actions.
+
+ In the following example, the action list begins with `collect'
+ commands indicating the things to be collected when the tracepoint
+ is hit. Then, in order to single-step and collect additional data
+ following the tracepoint, a `while-stepping' command is used,
+ followed by the list of things to be collected after each step in a
+ sequence of single steps. The `while-stepping' command is
+ terminated by its own separate `end' command. Lastly, the action
+ list is terminated by an `end' command.
+
+ (gdb) trace foo
+ (gdb) actions
+ Enter actions for tracepoint 1, one per line:
+ > collect bar,baz
+ > collect $regs
+ > while-stepping 12
+ > collect $pc, arr[i]
+ > end
+ end
+
+`collect[/MODS] EXPR1, EXPR2, ...'
+ Collect values of the given expressions when the tracepoint is hit.
+ This command accepts a comma-separated list of any valid
+ expressions. In addition to global, static, or local variables,
+ the following special arguments are supported:
+
+ `$regs'
+ Collect all registers.
+
+ `$args'
+ Collect all function arguments.
+
+ `$locals'
+ Collect all local variables.
+
+ `$_ret'
+ Collect the return address. This is helpful if you want to
+ see more of a backtrace.
+
+ `$_sdata'
+ Collect static tracepoint marker specific data. Only
+ available for static tracepoints. *Note Tracepoint Action
+ Lists: Tracepoint Actions. On the UST static tracepoints
+ library backend, an instrumentation point resembles a
+ `printf' function call. The tracing library is able to
+ collect user specified data formatted to a character string
+ using the format provided by the programmer that instrumented
+ the program. Other backends have similar mechanisms. Here's
+ an example of a UST marker call:
+
+ const char master_name[] = "$your_name";
+ trace_mark(channel1, marker1, "hello %s", master_name)
+
+ In this case, collecting `$_sdata' collects the string `hello
+ $yourname'. When analyzing the trace buffer, you can inspect
+ `$_sdata' like any other variable available to GDB.
+
+ You can give several consecutive `collect' commands, each one with
+ a single argument, or one `collect' command with several arguments
+ separated by commas; the effect is the same.
+
+ The optional MODS changes the usual handling of the arguments.
+ `s' requests that pointers to chars be handled as strings, in
+ particular collecting the contents of the memory being pointed at,
+ up to the first zero. The upper bound is by default the value of
+ the `print elements' variable; if `s' is followed by a decimal
+ number, that is the upper bound instead. So for instance
+ `collect/s25 mystr' collects as many as 25 characters at `mystr'.
+
+ The command `info scope' (*note info scope: Symbols.) is
+ particularly useful for figuring out what data to collect.
+
+`teval EXPR1, EXPR2, ...'
+ Evaluate the given expressions when the tracepoint is hit. This
+ command accepts a comma-separated list of expressions. The results
+ are discarded, so this is mainly useful for assigning values to
+ trace state variables (*note Trace State Variables::) without
+ adding those values to the trace buffer, as would be the case if
+ the `collect' action were used.
+
+`while-stepping N'
+ Perform N single-step instruction traces after the tracepoint,
+ collecting new data after each step. The `while-stepping' command
+ is followed by the list of what to collect while stepping
+ (followed by its own `end' command):
+
+ > while-stepping 12
+ > collect $regs, myglobal
+ > end
+ >
+
+ Note that `$pc' is not automatically collected by
+ `while-stepping'; you need to explicitly collect that register if
+ you need it. You may abbreviate `while-stepping' as `ws' or
+ `stepping'.
+
+`set default-collect EXPR1, EXPR2, ...'
+ This variable is a list of expressions to collect at each
+ tracepoint hit. It is effectively an additional `collect' action
+ prepended to every tracepoint action list. The expressions are
+ parsed individually for each tracepoint, so for instance a
+ variable named `xyz' may be interpreted as a global for one
+ tracepoint, and a local for another, as appropriate to the
+ tracepoint's location.
+
+`show default-collect'
+ Show the list of expressions that are collected by default at each
+ tracepoint hit.
+
+
+
+File: gdb.info, Node: Listing Tracepoints, Next: Listing Static Tracepoint Markers, Prev: Tracepoint Actions, Up: Set Tracepoints
+
+13.1.7 Listing Tracepoints
+--------------------------
+
+`info tracepoints [NUM...]'
+ Display information about the tracepoint NUM. If you don't
+ specify a tracepoint number, displays information about all the
+ tracepoints defined so far. The format is similar to that used for
+ `info breakpoints'; in fact, `info tracepoints' is the same
+ command, simply restricting itself to tracepoints.
+
+ A tracepoint's listing may include additional information specific
+ to tracing:
+
+ * its passcount as given by the `passcount N' command
+
+ (gdb) info trace
+ Num Type Disp Enb Address What
+ 1 tracepoint keep y 0x0804ab57 in foo() at main.cxx:7
+ while-stepping 20
+ collect globfoo, $regs
+ end
+ collect globfoo2
+ end
+ pass count 1200
+ (gdb)
+
+ This command can be abbreviated `info tp'.
+
+
+File: gdb.info, Node: Listing Static Tracepoint Markers, Next: Starting and Stopping Trace Experiments, Prev: Listing Tracepoints, Up: Set Tracepoints
+
+13.1.8 Listing Static Tracepoint Markers
+----------------------------------------
+
+`info static-tracepoint-markers'
+ Display information about all static tracepoint markers defined in
+ the program.
+
+ For each marker, the following columns are printed:
+
+ _Count_
+ An incrementing counter, output to help readability. This is
+ not a stable identifier.
+
+ _ID_
+ The marker ID, as reported by the target.
+
+ _Enabled or Disabled_
+ Probed markers are tagged with `y'. `n' identifies marks
+ that are not enabled.
+
+ _Address_
+ Where the marker is in your program, as a memory address.
+
+ _What_
+ Where the marker is in the source for your program, as a file
+ and line number. If the debug information included in the
+ program does not allow GDB to locate the source of the
+ marker, this column will be left blank.
+
+ In addition, the following information may be printed for each
+ marker:
+
+ _Data_
+ User data passed to the tracing library by the marker call.
+ In the UST backend, this is the format string passed as
+ argument to the marker call.
+
+ _Static tracepoints probing the marker_
+ The list of static tracepoints attached to the marker.
+
+ (gdb) info static-tracepoint-markers
+ Cnt ID Enb Address What
+ 1 ust/bar2 y 0x0000000000400e1a in main at stexample.c:25
+ Data: number1 %d number2 %d
+ Probed by static tracepoints: #2
+ 2 ust/bar33 n 0x0000000000400c87 in main at stexample.c:24
+ Data: str %s
+ (gdb)
+
+
+File: gdb.info, Node: Starting and Stopping Trace Experiments, Next: Tracepoint Restrictions, Prev: Listing Static Tracepoint Markers, Up: Set Tracepoints
+
+13.1.9 Starting and Stopping Trace Experiments
+----------------------------------------------
+
+`tstart'
+ This command starts the trace experiment, and begins collecting
+ data. It has the side effect of discarding all the data collected
+ in the trace buffer during the previous trace experiment. If any
+ arguments are supplied, they are taken as a note and stored with
+ the trace experiment's state. The notes may be arbitrary text,
+ and are especially useful with disconnected tracing in a
+ multi-user context; the notes can explain what the trace is doing,
+ supply user contact information, and so forth.
+
+`tstop'
+ This command stops the trace experiment. If any arguments are
+ supplied, they are recorded with the experiment as a note. This is
+ useful if you are stopping a trace started by someone else, for
+ instance if the trace is interfering with the system's behavior and
+ needs to be stopped quickly.
+
+ *Note*: a trace experiment and data collection may stop
+ automatically if any tracepoint's passcount is reached (*note
+ Tracepoint Passcounts::), or if the trace buffer becomes full.
+
+`tstatus'
+ This command displays the status of the current trace data
+ collection.
+
+ Here is an example of the commands we described so far:
+
+ (gdb) trace gdb_c_test
+ (gdb) actions
+ Enter actions for tracepoint #1, one per line.
+ > collect $regs,$locals,$args
+ > while-stepping 11
+ > collect $regs
+ > end
+ > end
+ (gdb) tstart
+ [time passes ...]
+ (gdb) tstop
+
+ You can choose to continue running the trace experiment even if GDB
+disconnects from the target, voluntarily or involuntarily. For
+commands such as `detach', the debugger will ask what you want to do
+with the trace. But for unexpected terminations (GDB crash, network
+outage), it would be unfortunate to lose hard-won trace data, so the
+variable `disconnected-tracing' lets you decide whether the trace should
+continue running without GDB.
+
+`set disconnected-tracing on'
+`set disconnected-tracing off'
+ Choose whether a tracing run should continue to run if GDB has
+ disconnected from the target. Note that `detach' or `quit' will
+ ask you directly what to do about a running trace no matter what
+ this variable's setting, so the variable is mainly useful for
+ handling unexpected situations, such as loss of the network.
+
+`show disconnected-tracing'
+ Show the current choice for disconnected tracing.
+
+
+ When you reconnect to the target, the trace experiment may or may not
+still be running; it might have filled the trace buffer in the
+meantime, or stopped for one of the other reasons. If it is running,
+it will continue after reconnection.
+
+ Upon reconnection, the target will upload information about the
+tracepoints in effect. GDB will then compare that information to the
+set of tracepoints currently defined, and attempt to match them up,
+allowing for the possibility that the numbers may have changed due to
+creation and deletion in the meantime. If one of the target's
+tracepoints does not match any in GDB, the debugger will create a new
+tracepoint, so that you have a number with which to specify that
+tracepoint. This matching-up process is necessarily heuristic, and it
+may result in useless tracepoints being created; you may simply delete
+them if they are of no use.
+
+ If your target agent supports a "circular trace buffer", then you
+can run a trace experiment indefinitely without filling the trace
+buffer; when space runs out, the agent deletes already-collected trace
+frames, oldest first, until there is enough room to continue
+collecting. This is especially useful if your tracepoints are being
+hit too often, and your trace gets terminated prematurely because the
+buffer is full. To ask for a circular trace buffer, simply set
+`circular-trace-buffer' to on. You can set this at any time, including
+during tracing; if the agent can do it, it will change buffer handling
+on the fly, otherwise it will not take effect until the next run.
+
+`set circular-trace-buffer on'
+`set circular-trace-buffer off'
+ Choose whether a tracing run should use a linear or circular buffer
+ for trace data. A linear buffer will not lose any trace data, but
+ may fill up prematurely, while a circular buffer will discard old
+ trace data, but it will have always room for the latest tracepoint
+ hits.
+
+`show circular-trace-buffer'
+ Show the current choice for the trace buffer. Note that this may
+ not match the agent's current buffer handling, nor is it
+ guaranteed to match the setting that might have been in effect
+ during a past run, for instance if you are looking at frames from
+ a trace file.
+
+
+`set trace-user TEXT'
+
+`show trace-user'
+
+`set trace-notes TEXT'
+ Set the trace run's notes.
+
+`show trace-notes'
+ Show the trace run's notes.
+
+`set trace-stop-notes TEXT'
+ Set the trace run's stop notes. The handling of the note is as for
+ `tstop' arguments; the set command is convenient way to fix a stop
+ note that is mistaken or incomplete.
+
+`show trace-stop-notes'
+ Show the trace run's stop notes.
+
+
+
+File: gdb.info, Node: Tracepoint Restrictions, Prev: Starting and Stopping Trace Experiments, Up: Set Tracepoints
+
+13.1.10 Tracepoint Restrictions
+-------------------------------
+
+There are a number of restrictions on the use of tracepoints. As
+described above, tracepoint data gathering occurs on the target without
+interaction from GDB. Thus the full capabilities of the debugger are
+not available during data gathering, and then at data examination time,
+you will be limited by only having what was collected. The following
+items describe some common problems, but it is not exhaustive, and you
+may run into additional difficulties not mentioned here.
+
+ * Tracepoint expressions are intended to gather objects (lvalues).
+ Thus the full flexibility of GDB's expression evaluator is not
+ available. You cannot call functions, cast objects to aggregate
+ types, access convenience variables or modify values (except by
+ assignment to trace state variables). Some language features may
+ implicitly call functions (for instance Objective-C fields with
+ accessors), and therefore cannot be collected either.
+
+ * Collection of local variables, either individually or in bulk with
+ `$locals' or `$args', during `while-stepping' may behave
+ erratically. The stepping action may enter a new scope (for
+ instance by stepping into a function), or the location of the
+ variable may change (for instance it is loaded into a register).
+ The tracepoint data recorded uses the location information for the
+ variables that is correct for the tracepoint location. When the
+ tracepoint is created, it is not possible, in general, to determine
+ where the steps of a `while-stepping' sequence will advance the
+ program--particularly if a conditional branch is stepped.
+
+ * Collection of an incompletely-initialized or partially-destroyed
+ object may result in something that GDB cannot display, or displays
+ in a misleading way.
+
+ * When GDB displays a pointer to character it automatically
+ dereferences the pointer to also display characters of the string
+ being pointed to. However, collecting the pointer during tracing
+ does not automatically collect the string. You need to explicitly
+ dereference the pointer and provide size information if you want to
+ collect not only the pointer, but the memory pointed to. For
+ example, `*ptr@50' can be used to collect the 50 element array
+ pointed to by `ptr'.
+
+ * It is not possible to collect a complete stack backtrace at a
+ tracepoint. Instead, you may collect the registers and a few
+ hundred bytes from the stack pointer with something like
+ `*(unsigned char *)$esp@300' (adjust to use the name of the actual
+ stack pointer register on your target architecture, and the amount
+ of stack you wish to capture). Then the `backtrace' command will
+ show a partial backtrace when using a trace frame. The number of
+ stack frames that can be examined depends on the sizes of the
+ frames in the collected stack. Note that if you ask for a block
+ so large that it goes past the bottom of the stack, the target
+ agent may report an error trying to read from an invalid address.
+
+ * If you do not collect registers at a tracepoint, GDB can infer
+ that the value of `$pc' must be the same as the address of the
+ tracepoint and use that when you are looking at a trace frame for
+ that tracepoint. However, this cannot work if the tracepoint has
+ multiple locations (for instance if it was set in a function that
+ was inlined), or if it has a `while-stepping' loop. In those cases
+ GDB will warn you that it can't infer `$pc', and default it to
+ zero.
+
+
+
+File: gdb.info, Node: Analyze Collected Data, Next: Tracepoint Variables, Prev: Set Tracepoints, Up: Tracepoints
+
+13.2 Using the Collected Data
+=============================
+
+After the tracepoint experiment ends, you use GDB commands for
+examining the trace data. The basic idea is that each tracepoint
+collects a trace "snapshot" every time it is hit and another snapshot
+every time it single-steps. All these snapshots are consecutively
+numbered from zero and go into a buffer, and you can examine them
+later. The way you examine them is to "focus" on a specific trace
+snapshot. When the remote stub is focused on a trace snapshot, it will
+respond to all GDB requests for memory and registers by reading from
+the buffer which belongs to that snapshot, rather than from _real_
+memory or registers of the program being debugged. This means that
+*all* GDB commands (`print', `info registers', `backtrace', etc.) will
+behave as if we were currently debugging the program state as it was
+when the tracepoint occurred. Any requests for data that are not in
+the buffer will fail.
+
+* Menu:
+
+* tfind:: How to select a trace snapshot
+* tdump:: How to display all data for a snapshot
+* save tracepoints:: How to save tracepoints for a future run
+
+
+File: gdb.info, Node: tfind, Next: tdump, Up: Analyze Collected Data
+
+13.2.1 `tfind N'
+----------------
+
+The basic command for selecting a trace snapshot from the buffer is
+`tfind N', which finds trace snapshot number N, counting from zero. If
+no argument N is given, the next snapshot is selected.
+
+ Here are the various forms of using the `tfind' command.
+
+`tfind start'
+ Find the first snapshot in the buffer. This is a synonym for
+ `tfind 0' (since 0 is the number of the first snapshot).
+
+`tfind none'
+ Stop debugging trace snapshots, resume _live_ debugging.
+
+`tfind end'
+ Same as `tfind none'.
+
+`tfind'
+ No argument means find the next trace snapshot.
+
+`tfind -'
+ Find the previous trace snapshot before the current one. This
+ permits retracing earlier steps.
+
+`tfind tracepoint NUM'
+ Find the next snapshot associated with tracepoint NUM. Search
+ proceeds forward from the last examined trace snapshot. If no
+ argument NUM is given, it means find the next snapshot collected
+ for the same tracepoint as the current snapshot.
+
+`tfind pc ADDR'
+ Find the next snapshot associated with the value ADDR of the
+ program counter. Search proceeds forward from the last examined
+ trace snapshot. If no argument ADDR is given, it means find the
+ next snapshot with the same value of PC as the current snapshot.
+
+`tfind outside ADDR1, ADDR2'
+ Find the next snapshot whose PC is outside the given range of
+ addresses (exclusive).
+
+`tfind range ADDR1, ADDR2'
+ Find the next snapshot whose PC is between ADDR1 and ADDR2
+ (inclusive).
+
+`tfind line [FILE:]N'
+ Find the next snapshot associated with the source line N. If the
+ optional argument FILE is given, refer to line N in that source
+ file. Search proceeds forward from the last examined trace
+ snapshot. If no argument N is given, it means find the next line
+ other than the one currently being examined; thus saying `tfind
+ line' repeatedly can appear to have the same effect as stepping
+ from line to line in a _live_ debugging session.
+
+ The default arguments for the `tfind' commands are specifically
+designed to make it easy to scan through the trace buffer. For
+instance, `tfind' with no argument selects the next trace snapshot, and
+`tfind -' with no argument selects the previous trace snapshot. So, by
+giving one `tfind' command, and then simply hitting <RET> repeatedly
+you can examine all the trace snapshots in order. Or, by saying `tfind
+-' and then hitting <RET> repeatedly you can examine the snapshots in
+reverse order. The `tfind line' command with no argument selects the
+snapshot for the next source line executed. The `tfind pc' command with
+no argument selects the next snapshot with the same program counter
+(PC) as the current frame. The `tfind tracepoint' command with no
+argument selects the next trace snapshot collected by the same
+tracepoint as the current one.
+
+ In addition to letting you scan through the trace buffer manually,
+these commands make it easy to construct GDB scripts that scan through
+the trace buffer and print out whatever collected data you are
+interested in. Thus, if we want to examine the PC, FP, and SP
+registers from each trace frame in the buffer, we can say this:
+
+ (gdb) tfind start
+ (gdb) while ($trace_frame != -1)
+ > printf "Frame %d, PC = %08X, SP = %08X, FP = %08X\n", \
+ $trace_frame, $pc, $sp, $fp
+ > tfind
+ > end
+
+ Frame 0, PC = 0020DC64, SP = 0030BF3C, FP = 0030BF44
+ Frame 1, PC = 0020DC6C, SP = 0030BF38, FP = 0030BF44
+ Frame 2, PC = 0020DC70, SP = 0030BF34, FP = 0030BF44
+ Frame 3, PC = 0020DC74, SP = 0030BF30, FP = 0030BF44
+ Frame 4, PC = 0020DC78, SP = 0030BF2C, FP = 0030BF44
+ Frame 5, PC = 0020DC7C, SP = 0030BF28, FP = 0030BF44
+ Frame 6, PC = 0020DC80, SP = 0030BF24, FP = 0030BF44
+ Frame 7, PC = 0020DC84, SP = 0030BF20, FP = 0030BF44
+ Frame 8, PC = 0020DC88, SP = 0030BF1C, FP = 0030BF44
+ Frame 9, PC = 0020DC8E, SP = 0030BF18, FP = 0030BF44
+ Frame 10, PC = 00203F6C, SP = 0030BE3C, FP = 0030BF14
+
+ Or, if we want to examine the variable `X' at each source line in
+the buffer:
+
+ (gdb) tfind start
+ (gdb) while ($trace_frame != -1)
+ > printf "Frame %d, X == %d\n", $trace_frame, X
+ > tfind line
+ > end
+
+ Frame 0, X = 1
+ Frame 7, X = 2
+ Frame 13, X = 255
+
+
+File: gdb.info, Node: tdump, Next: save tracepoints, Prev: tfind, Up: Analyze Collected Data
+
+13.2.2 `tdump'
+--------------
+
+This command takes no arguments. It prints all the data collected at
+the current trace snapshot.
+
+ (gdb) trace 444
+ (gdb) actions
+ Enter actions for tracepoint #2, one per line:
+ > collect $regs, $locals, $args, gdb_long_test
+ > end
+
+ (gdb) tstart
+
+ (gdb) tfind line 444
+ #0 gdb_test (p1=0x11, p2=0x22, p3=0x33, p4=0x44, p5=0x55, p6=0x66)
+ at gdb_test.c:444
+ 444 printp( "%s: arguments = 0x%X 0x%X 0x%X 0x%X 0x%X 0x%X\n", )
+
+ (gdb) tdump
+ Data collected at tracepoint 2, trace frame 1:
+ d0 0xc4aa0085 -995491707
+ d1 0x18 24
+ d2 0x80 128
+ d3 0x33 51
+ d4 0x71aea3d 119204413
+ d5 0x22 34
+ d6 0xe0 224
+ d7 0x380035 3670069
+ a0 0x19e24a 1696330
+ a1 0x3000668 50333288
+ a2 0x100 256
+ a3 0x322000 3284992
+ a4 0x3000698 50333336
+ a5 0x1ad3cc 1758156
+ fp 0x30bf3c 0x30bf3c
+ sp 0x30bf34 0x30bf34
+ ps 0x0 0
+ pc 0x20b2c8 0x20b2c8
+ fpcontrol 0x0 0
+ fpstatus 0x0 0
+ fpiaddr 0x0 0
+ p = 0x20e5b4 "gdb-test"
+ p1 = (void *) 0x11
+ p2 = (void *) 0x22
+ p3 = (void *) 0x33
+ p4 = (void *) 0x44
+ p5 = (void *) 0x55
+ p6 = (void *) 0x66
+ gdb_long_test = 17 '\021'
+
+ (gdb)
+
+ `tdump' works by scanning the tracepoint's current collection
+actions and printing the value of each expression listed. So `tdump'
+can fail, if after a run, you change the tracepoint's actions to
+mention variables that were not collected during the run.
+
+ Also, for tracepoints with `while-stepping' loops, `tdump' uses the
+collected value of `$pc' to distinguish between trace frames that were
+collected at the tracepoint hit, and frames that were collected while
+stepping. This allows it to correctly choose whether to display the
+basic list of collections, or the collections from the body of the
+while-stepping loop. However, if `$pc' was not collected, then `tdump'
+will always attempt to dump using the basic collection list, and may
+fail if a while-stepping frame does not include all the same data that
+is collected at the tracepoint hit.
+
+
+File: gdb.info, Node: save tracepoints, Prev: tdump, Up: Analyze Collected Data
+
+13.2.3 `save tracepoints FILENAME'
+----------------------------------
+
+This command saves all current tracepoint definitions together with
+their actions and passcounts, into a file `FILENAME' suitable for use
+in a later debugging session. To read the saved tracepoint
+definitions, use the `source' command (*note Command Files::). The
+`save-tracepoints' command is a deprecated alias for `save tracepoints'
+
+
+File: gdb.info, Node: Tracepoint Variables, Next: Trace Files, Prev: Analyze Collected Data, Up: Tracepoints
+
+13.3 Convenience Variables for Tracepoints
+==========================================
+
+`(int) $trace_frame'
+ The current trace snapshot (a.k.a. "frame") number, or -1 if no
+ snapshot is selected.
+
+`(int) $tracepoint'
+ The tracepoint for the current trace snapshot.
+
+`(int) $trace_line'
+ The line number for the current trace snapshot.
+
+`(char []) $trace_file'
+ The source file for the current trace snapshot.
+
+`(char []) $trace_func'
+ The name of the function containing `$tracepoint'.
+
+ Note: `$trace_file' is not suitable for use in `printf', use
+`output' instead.
+
+ Here's a simple example of using these convenience variables for
+stepping through all the trace snapshots and printing some of their
+data. Note that these are not the same as trace state variables, which
+are managed by the target.
+
+ (gdb) tfind start
+
+ (gdb) while $trace_frame != -1
+ > output $trace_file
+ > printf ", line %d (tracepoint #%d)\n", $trace_line, $tracepoint
+ > tfind
+ > end
+
+
+File: gdb.info, Node: Trace Files, Prev: Tracepoint Variables, Up: Tracepoints
+
+13.4 Using Trace Files
+======================
+
+In some situations, the target running a trace experiment may no longer
+be available; perhaps it crashed, or the hardware was needed for a
+different activity. To handle these cases, you can arrange to dump the
+trace data into a file, and later use that file as a source of trace
+data, via the `target tfile' command.
+
+`tsave [ -r ] FILENAME'
+ Save the trace data to FILENAME. By default, this command assumes
+ that FILENAME refers to the host filesystem, so if necessary GDB
+ will copy raw trace data up from the target and then save it. If
+ the target supports it, you can also supply the optional argument
+ `-r' ("remote") to direct the target to save the data directly
+ into FILENAME in its own filesystem, which may be more efficient
+ if the trace buffer is very large. (Note, however, that `target
+ tfile' can only read from files accessible to the host.)
+
+`target tfile FILENAME'
+ Use the file named FILENAME as a source of trace data. Commands
+ that examine data work as they do with a live target, but it is not
+ possible to run any new trace experiments. `tstatus' will report
+ the state of the trace run at the moment the data was saved, as
+ well as the current trace frame you are examining. FILENAME must
+ be on a filesystem accessible to the host.
+
+
+
+File: gdb.info, Node: Overlays, Next: Languages, Prev: Tracepoints, Up: Top
+
+14 Debugging Programs That Use Overlays
+***************************************
+
+If your program is too large to fit completely in your target system's
+memory, you can sometimes use "overlays" to work around this problem.
+GDB provides some support for debugging programs that use overlays.
+
+* Menu:
+
+* How Overlays Work:: A general explanation of overlays.
+* Overlay Commands:: Managing overlays in GDB.
+* Automatic Overlay Debugging:: GDB can find out which overlays are
+ mapped by asking the inferior.
+* Overlay Sample Program:: A sample program using overlays.
+
+
+File: gdb.info, Node: How Overlays Work, Next: Overlay Commands, Up: Overlays
+
+14.1 How Overlays Work
+======================
+
+Suppose you have a computer whose instruction address space is only 64
+kilobytes long, but which has much more memory which can be accessed by
+other means: special instructions, segment registers, or memory
+management hardware, for example. Suppose further that you want to
+adapt a program which is larger than 64 kilobytes to run on this system.
+
+ One solution is to identify modules of your program which are
+relatively independent, and need not call each other directly; call
+these modules "overlays". Separate the overlays from the main program,
+and place their machine code in the larger memory. Place your main
+program in instruction memory, but leave at least enough space there to
+hold the largest overlay as well.
+
+ Now, to call a function located in an overlay, you must first copy
+that overlay's machine code from the large memory into the space set
+aside for it in the instruction memory, and then jump to its entry point
+there.
+
+ Data Instruction Larger
+ Address Space Address Space Address Space
+ +-----------+ +-----------+ +-----------+
+ | | | | | |
+ +-----------+ +-----------+ +-----------+<-- overlay 1
+ | program | | main | .----| overlay 1 | load address
+ | variables | | program | | +-----------+
+ | and heap | | | | | |
+ +-----------+ | | | +-----------+<-- overlay 2
+ | | +-----------+ | | | load address
+ +-----------+ | | | .-| overlay 2 |
+ | | | | | |
+ mapped --->+-----------+ | | +-----------+
+ address | | | | | |
+ | overlay | <-' | | |
+ | area | <---' +-----------+<-- overlay 3
+ | | <---. | | load address
+ +-----------+ `--| overlay 3 |
+ | | | |
+ +-----------+ | |
+ +-----------+
+ | |
+ +-----------+
+
+ A code overlay
+
+ The diagram (*note A code overlay::) shows a system with separate
+data and instruction address spaces. To map an overlay, the program
+copies its code from the larger address space to the instruction
+address space. Since the overlays shown here all use the same mapped
+address, only one may be mapped at a time. For a system with a single
+address space for data and instructions, the diagram would be similar,
+except that the program variables and heap would share an address space
+with the main program and the overlay area.
+
+ An overlay loaded into instruction memory and ready for use is
+called a "mapped" overlay; its "mapped address" is its address in the
+instruction memory. An overlay not present (or only partially present)
+in instruction memory is called "unmapped"; its "load address" is its
+address in the larger memory. The mapped address is also called the
+"virtual memory address", or "VMA"; the load address is also called the
+"load memory address", or "LMA".
+
+ Unfortunately, overlays are not a completely transparent way to
+adapt a program to limited instruction memory. They introduce a new
+set of global constraints you must keep in mind as you design your
+program:
+
+ * Before calling or returning to a function in an overlay, your
+ program must make sure that overlay is actually mapped.
+ Otherwise, the call or return will transfer control to the right
+ address, but in the wrong overlay, and your program will probably
+ crash.
+
+ * If the process of mapping an overlay is expensive on your system,
+ you will need to choose your overlays carefully to minimize their
+ effect on your program's performance.
+
+ * The executable file you load onto your system must contain each
+ overlay's instructions, appearing at the overlay's load address,
+ not its mapped address. However, each overlay's instructions must
+ be relocated and its symbols defined as if the overlay were at its
+ mapped address. You can use GNU linker scripts to specify
+ different load and relocation addresses for pieces of your
+ program; see *Note Overlay Description: (ld.info)Overlay
+ Description.
+
+ * The procedure for loading executable files onto your system must
+ be able to load their contents into the larger address space as
+ well as the instruction and data spaces.
+
+
+ The overlay system described above is rather simple, and could be
+improved in many ways:
+
+ * If your system has suitable bank switch registers or memory
+ management hardware, you could use those facilities to make an
+ overlay's load area contents simply appear at their mapped address
+ in instruction space. This would probably be faster than copying
+ the overlay to its mapped area in the usual way.
+
+ * If your overlays are small enough, you could set aside more than
+ one overlay area, and have more than one overlay mapped at a time.
+
+ * You can use overlays to manage data, as well as instructions. In
+ general, data overlays are even less transparent to your design
+ than code overlays: whereas code overlays only require care when
+ you call or return to functions, data overlays require care every
+ time you access the data. Also, if you change the contents of a
+ data overlay, you must copy its contents back out to its load
+ address before you can copy a different data overlay into the same
+ mapped area.
+
+
+
+File: gdb.info, Node: Overlay Commands, Next: Automatic Overlay Debugging, Prev: How Overlays Work, Up: Overlays
+
+14.2 Overlay Commands
+=====================
+
+To use GDB's overlay support, each overlay in your program must
+correspond to a separate section of the executable file. The section's
+virtual memory address and load memory address must be the overlay's
+mapped and load addresses. Identifying overlays with sections allows
+GDB to determine the appropriate address of a function or variable,
+depending on whether the overlay is mapped or not.
+
+ GDB's overlay commands all start with the word `overlay'; you can
+abbreviate this as `ov' or `ovly'. The commands are:
+
+`overlay off'
+ Disable GDB's overlay support. When overlay support is disabled,
+ GDB assumes that all functions and variables are always present at
+ their mapped addresses. By default, GDB's overlay support is
+ disabled.
+
+`overlay manual'
+ Enable "manual" overlay debugging. In this mode, GDB relies on
+ you to tell it which overlays are mapped, and which are not, using
+ the `overlay map-overlay' and `overlay unmap-overlay' commands
+ described below.
+
+`overlay map-overlay OVERLAY'
+`overlay map OVERLAY'
+ Tell GDB that OVERLAY is now mapped; OVERLAY must be the name of
+ the object file section containing the overlay. When an overlay
+ is mapped, GDB assumes it can find the overlay's functions and
+ variables at their mapped addresses. GDB assumes that any other
+ overlays whose mapped ranges overlap that of OVERLAY are now
+ unmapped.
+
+`overlay unmap-overlay OVERLAY'
+`overlay unmap OVERLAY'
+ Tell GDB that OVERLAY is no longer mapped; OVERLAY must be the
+ name of the object file section containing the overlay. When an
+ overlay is unmapped, GDB assumes it can find the overlay's
+ functions and variables at their load addresses.
+
+`overlay auto'
+ Enable "automatic" overlay debugging. In this mode, GDB consults
+ a data structure the overlay manager maintains in the inferior to
+ see which overlays are mapped. For details, see *Note Automatic
+ Overlay Debugging::.
+
+`overlay load-target'
+`overlay load'
+ Re-read the overlay table from the inferior. Normally, GDB
+ re-reads the table GDB automatically each time the inferior stops,
+ so this command should only be necessary if you have changed the
+ overlay mapping yourself using GDB. This command is only useful
+ when using automatic overlay debugging.
+
+`overlay list-overlays'
+`overlay list'
+ Display a list of the overlays currently mapped, along with their
+ mapped addresses, load addresses, and sizes.
+
+
+ Normally, when GDB prints a code address, it includes the name of
+the function the address falls in:
+
+ (gdb) print main
+ $3 = {int ()} 0x11a0 <main>
+ When overlay debugging is enabled, GDB recognizes code in unmapped
+overlays, and prints the names of unmapped functions with asterisks
+around them. For example, if `foo' is a function in an unmapped
+overlay, GDB prints it this way:
+
+ (gdb) overlay list
+ No sections are mapped.
+ (gdb) print foo
+ $5 = {int (int)} 0x100000 <*foo*>
+ When `foo''s overlay is mapped, GDB prints the function's name
+normally:
+
+ (gdb) overlay list
+ Section .ov.foo.text, loaded at 0x100000 - 0x100034,
+ mapped at 0x1016 - 0x104a
+ (gdb) print foo
+ $6 = {int (int)} 0x1016 <foo>
+
+ When overlay debugging is enabled, GDB can find the correct address
+for functions and variables in an overlay, whether or not the overlay
+is mapped. This allows most GDB commands, like `break' and
+`disassemble', to work normally, even on unmapped code. However, GDB's
+breakpoint support has some limitations:
+
+ * You can set breakpoints in functions in unmapped overlays, as long
+ as GDB can write to the overlay at its load address.
+
+ * GDB can not set hardware or simulator-based breakpoints in
+ unmapped overlays. However, if you set a breakpoint at the end of
+ your overlay manager (and tell GDB which overlays are now mapped,
+ if you are using manual overlay management), GDB will re-set its
+ breakpoints properly.
+
+
+File: gdb.info, Node: Automatic Overlay Debugging, Next: Overlay Sample Program, Prev: Overlay Commands, Up: Overlays
+
+14.3 Automatic Overlay Debugging
+================================
+
+GDB can automatically track which overlays are mapped and which are
+not, given some simple co-operation from the overlay manager in the
+inferior. If you enable automatic overlay debugging with the `overlay
+auto' command (*note Overlay Commands::), GDB looks in the inferior's
+memory for certain variables describing the current state of the
+overlays.
+
+ Here are the variables your overlay manager must define to support
+GDB's automatic overlay debugging:
+
+`_ovly_table':
+ This variable must be an array of the following structures:
+
+ struct
+ {
+ /* The overlay's mapped address. */
+ unsigned long vma;
+
+ /* The size of the overlay, in bytes. */
+ unsigned long size;
+
+ /* The overlay's load address. */
+ unsigned long lma;
+
+ /* Non-zero if the overlay is currently mapped;
+ zero otherwise. */
+ unsigned long mapped;
+ }
+
+`_novlys':
+ This variable must be a four-byte signed integer, holding the total
+ number of elements in `_ovly_table'.
+
+
+ To decide whether a particular overlay is mapped or not, GDB looks
+for an entry in `_ovly_table' whose `vma' and `lma' members equal the
+VMA and LMA of the overlay's section in the executable file. When GDB
+finds a matching entry, it consults the entry's `mapped' member to
+determine whether the overlay is currently mapped.
+
+ In addition, your overlay manager may define a function called
+`_ovly_debug_event'. If this function is defined, GDB will silently
+set a breakpoint there. If the overlay manager then calls this
+function whenever it has changed the overlay table, this will enable
+GDB to accurately keep track of which overlays are in program memory,
+and update any breakpoints that may be set in overlays. This will
+allow breakpoints to work even if the overlays are kept in ROM or other
+non-writable memory while they are not being executed.
+
+
+File: gdb.info, Node: Overlay Sample Program, Prev: Automatic Overlay Debugging, Up: Overlays
+
+14.4 Overlay Sample Program
+===========================
+
+When linking a program which uses overlays, you must place the overlays
+at their load addresses, while relocating them to run at their mapped
+addresses. To do this, you must write a linker script (*note Overlay
+Description: (ld.info)Overlay Description.). Unfortunately, since
+linker scripts are specific to a particular host system, target
+architecture, and target memory layout, this manual cannot provide
+portable sample code demonstrating GDB's overlay support.
+
+ However, the GDB source distribution does contain an overlaid
+program, with linker scripts for a few systems, as part of its test
+suite. The program consists of the following files from
+`gdb/testsuite/gdb.base':
+
+`overlays.c'
+ The main program file.
+
+`ovlymgr.c'
+ A simple overlay manager, used by `overlays.c'.
+
+`foo.c'
+`bar.c'
+`baz.c'
+`grbx.c'
+ Overlay modules, loaded and used by `overlays.c'.
+
+`d10v.ld'
+`m32r.ld'
+ Linker scripts for linking the test program on the `d10v-elf' and
+ `m32r-elf' targets.
+
+ You can build the test program using the `d10v-elf' GCC
+cross-compiler like this:
+
+ $ d10v-elf-gcc -g -c overlays.c
+ $ d10v-elf-gcc -g -c ovlymgr.c
+ $ d10v-elf-gcc -g -c foo.c
+ $ d10v-elf-gcc -g -c bar.c
+ $ d10v-elf-gcc -g -c baz.c
+ $ d10v-elf-gcc -g -c grbx.c
+ $ d10v-elf-gcc -g overlays.o ovlymgr.o foo.o bar.o \
+ baz.o grbx.o -Wl,-Td10v.ld -o overlays
+
+ The build process is identical for any other architecture, except
+that you must substitute the appropriate compiler and linker script for
+the target system for `d10v-elf-gcc' and `d10v.ld'.
+
+
+File: gdb.info, Node: Languages, Next: Symbols, Prev: Overlays, Up: Top
+
+15 Using GDB with Different Languages
+*************************************
+
+Although programming languages generally have common aspects, they are
+rarely expressed in the same manner. For instance, in ANSI C,
+dereferencing a pointer `p' is accomplished by `*p', but in Modula-2,
+it is accomplished by `p^'. Values can also be represented (and
+displayed) differently. Hex numbers in C appear as `0x1ae', while in
+Modula-2 they appear as `1AEH'.
+
+ Language-specific information is built into GDB for some languages,
+allowing you to express operations like the above in your program's
+native language, and allowing GDB to output values in a manner
+consistent with the syntax of your program's native language. The
+language you use to build expressions is called the "working language".
+
+* Menu:
+
+* Setting:: Switching between source languages
+* Show:: Displaying the language
+* Checks:: Type and range checks
+* Supported Languages:: Supported languages
+* Unsupported Languages:: Unsupported languages
+
+
+File: gdb.info, Node: Setting, Next: Show, Up: Languages
+
+15.1 Switching Between Source Languages
+=======================================
+
+There are two ways to control the working language--either have GDB set
+it automatically, or select it manually yourself. You can use the `set
+language' command for either purpose. On startup, GDB defaults to
+setting the language automatically. The working language is used to
+determine how expressions you type are interpreted, how values are
+printed, etc.
+
+ In addition to the working language, every source file that GDB
+knows about has its own working language. For some object file
+formats, the compiler might indicate which language a particular source
+file is in. However, most of the time GDB infers the language from the
+name of the file. The language of a source file controls whether C++
+names are demangled--this way `backtrace' can show each frame
+appropriately for its own language. There is no way to set the
+language of a source file from within GDB, but you can set the language
+associated with a filename extension. *Note Displaying the Language:
+Show.
+
+ This is most commonly a problem when you use a program, such as
+`cfront' or `f2c', that generates C but is written in another language.
+In that case, make the program use `#line' directives in its C output;
+that way GDB will know the correct language of the source code of the
+original program, and will display that source code, not the generated
+C code.
+
+* Menu:
+
+* Filenames:: Filename extensions and languages.
+* Manually:: Setting the working language manually
+* Automatically:: Having GDB infer the source language
+
+
+File: gdb.info, Node: Filenames, Next: Manually, Up: Setting
+
+15.1.1 List of Filename Extensions and Languages
+------------------------------------------------
+
+If a source file name ends in one of the following extensions, then GDB
+infers that its language is the one indicated.
+
+`.ada'
+`.ads'
+`.adb'
+`.a'
+ Ada source file.
+
+`.c'
+ C source file
+
+`.C'
+`.cc'
+`.cp'
+`.cpp'
+`.cxx'
+`.c++'
+ C++ source file
+
+`.d'
+ D source file
+
+`.m'
+ Objective-C source file
+
+`.f'
+`.F'
+ Fortran source file
+
+`.mod'
+ Modula-2 source file
+
+`.s'
+`.S'
+ Assembler source file. This actually behaves almost like C, but
+ GDB does not skip over function prologues when stepping.
+
+ In addition, you may set the language associated with a filename
+extension. *Note Displaying the Language: Show.
+
+
+File: gdb.info, Node: Manually, Next: Automatically, Prev: Filenames, Up: Setting
+
+15.1.2 Setting the Working Language
+-----------------------------------
+
+If you allow GDB to set the language automatically, expressions are
+interpreted the same way in your debugging session and your program.
+
+ If you wish, you may set the language manually. To do this, issue
+the command `set language LANG', where LANG is the name of a language,
+such as `c' or `modula-2'. For a list of the supported languages, type
+`set language'.
+
+ Setting the language manually prevents GDB from updating the working
+language automatically. This can lead to confusion if you try to debug
+a program when the working language is not the same as the source
+language, when an expression is acceptable to both languages--but means
+different things. For instance, if the current source file were
+written in C, and GDB was parsing Modula-2, a command such as:
+
+ print a = b + c
+
+might not have the effect you intended. In C, this means to add `b'
+and `c' and place the result in `a'. The result printed would be the
+value of `a'. In Modula-2, this means to compare `a' to the result of
+`b+c', yielding a `BOOLEAN' value.
+
+
+File: gdb.info, Node: Automatically, Prev: Manually, Up: Setting
+
+15.1.3 Having GDB Infer the Source Language
+-------------------------------------------
+
+To have GDB set the working language automatically, use `set language
+local' or `set language auto'. GDB then infers the working language.
+That is, when your program stops in a frame (usually by encountering a
+breakpoint), GDB sets the working language to the language recorded for
+the function in that frame. If the language for a frame is unknown
+(that is, if the function or block corresponding to the frame was
+defined in a source file that does not have a recognized extension),
+the current working language is not changed, and GDB issues a warning.
+
+ This may not seem necessary for most programs, which are written
+entirely in one source language. However, program modules and libraries
+written in one source language can be used by a main program written in
+a different source language. Using `set language auto' in this case
+frees you from having to set the working language manually.
+
+
+File: gdb.info, Node: Show, Next: Checks, Prev: Setting, Up: Languages
+
+15.2 Displaying the Language
+============================
+
+The following commands help you find out which language is the working
+language, and also what language source files were written in.
+
+`show language'
+ Display the current working language. This is the language you
+ can use with commands such as `print' to build and compute
+ expressions that may involve variables in your program.
+
+`info frame'
+ Display the source language for this frame. This language becomes
+ the working language if you use an identifier from this frame.
+ *Note Information about a Frame: Frame Info, to identify the other
+ information listed here.
+
+`info source'
+ Display the source language of this source file. *Note Examining
+ the Symbol Table: Symbols, to identify the other information
+ listed here.
+
+ In unusual circumstances, you may have source files with extensions
+not in the standard list. You can then set the extension associated
+with a language explicitly:
+
+`set extension-language EXT LANGUAGE'
+ Tell GDB that source files with extension EXT are to be assumed as
+ written in the source language LANGUAGE.
+
+`info extensions'
+ List all the filename extensions and the associated languages.
+
+
+File: gdb.info, Node: Checks, Next: Supported Languages, Prev: Show, Up: Languages
+
+15.3 Type and Range Checking
+============================
+
+ _Warning:_ In this release, the GDB commands for type and range
+ checking are included, but they do not yet have any effect. This
+ section documents the intended facilities.
+
+ Some languages are designed to guard you against making seemingly
+common errors through a series of compile- and run-time checks. These
+include checking the type of arguments to functions and operators, and
+making sure mathematical overflows are caught at run time. Checks such
+as these help to ensure a program's correctness once it has been
+compiled by eliminating type mismatches, and providing active checks
+for range errors when your program is running.
+
+ GDB can check for conditions like the above if you wish. Although
+GDB does not check the statements in your program, it can check
+expressions entered directly into GDB for evaluation via the `print'
+command, for example. As with the working language, GDB can also
+decide whether or not to check automatically based on your program's
+source language. *Note Supported Languages: Supported Languages, for
+the default settings of supported languages.
+
+* Menu:
+
+* Type Checking:: An overview of type checking
+* Range Checking:: An overview of range checking
+
+
+File: gdb.info, Node: Type Checking, Next: Range Checking, Up: Checks
+
+15.3.1 An Overview of Type Checking
+-----------------------------------
+
+Some languages, such as Modula-2, are strongly typed, meaning that the
+arguments to operators and functions have to be of the correct type,
+otherwise an error occurs. These checks prevent type mismatch errors
+from ever causing any run-time problems. For example,
+
+ 1 + 2 => 3
+but
+ error--> 1 + 2.3
+
+ The second example fails because the `CARDINAL' 1 is not
+type-compatible with the `REAL' 2.3.
+
+ For the expressions you use in GDB commands, you can tell the GDB
+type checker to skip checking; to treat any mismatches as errors and
+abandon the expression; or to only issue warnings when type mismatches
+occur, but evaluate the expression anyway. When you choose the last of
+these, GDB evaluates expressions like the second example above, but
+also issues a warning.
+
+ Even if you turn type checking off, there may be other reasons
+related to type that prevent GDB from evaluating an expression. For
+instance, GDB does not know how to add an `int' and a `struct foo'.
+These particular type errors have nothing to do with the language in
+use, and usually arise from expressions, such as the one described
+above, which make little sense to evaluate anyway.
+
+ Each language defines to what degree it is strict about type. For
+instance, both Modula-2 and C require the arguments to arithmetical
+operators to be numbers. In C, enumerated types and pointers can be
+represented as numbers, so that they are valid arguments to mathematical
+operators. *Note Supported Languages: Supported Languages, for further
+details on specific languages.
+
+ GDB provides some additional commands for controlling the type
+checker:
+
+`set check type auto'
+ Set type checking on or off based on the current working language.
+ *Note Supported Languages: Supported Languages, for the default
+ settings for each language.
+
+`set check type on'
+`set check type off'
+ Set type checking on or off, overriding the default setting for the
+ current working language. Issue a warning if the setting does not
+ match the language default. If any type mismatches occur in
+ evaluating an expression while type checking is on, GDB prints a
+ message and aborts evaluation of the expression.
+
+`set check type warn'
+ Cause the type checker to issue warnings, but to always attempt to
+ evaluate the expression. Evaluating the expression may still be
+ impossible for other reasons. For example, GDB cannot add numbers
+ and structures.
+
+`show type'
+ Show the current setting of the type checker, and whether or not
+ GDB is setting it automatically.
+
+
+File: gdb.info, Node: Range Checking, Prev: Type Checking, Up: Checks
+
+15.3.2 An Overview of Range Checking
+------------------------------------
+
+In some languages (such as Modula-2), it is an error to exceed the
+bounds of a type; this is enforced with run-time checks. Such range
+checking is meant to ensure program correctness by making sure
+computations do not overflow, or indices on an array element access do
+not exceed the bounds of the array.
+
+ For expressions you use in GDB commands, you can tell GDB to treat
+range errors in one of three ways: ignore them, always treat them as
+errors and abandon the expression, or issue warnings but evaluate the
+expression anyway.
+
+ A range error can result from numerical overflow, from exceeding an
+array index bound, or when you type a constant that is not a member of
+any type. Some languages, however, do not treat overflows as an error.
+In many implementations of C, mathematical overflow causes the result
+to "wrap around" to lower values--for example, if M is the largest
+integer value, and S is the smallest, then
+
+ M + 1 => S
+
+ This, too, is specific to individual languages, and in some cases
+specific to individual compilers or machines. *Note Supported
+Languages: Supported Languages, for further details on specific
+languages.
+
+ GDB provides some additional commands for controlling the range
+checker:
+
+`set check range auto'
+ Set range checking on or off based on the current working language.
+ *Note Supported Languages: Supported Languages, for the default
+ settings for each language.
+
+`set check range on'
+`set check range off'
+ Set range checking on or off, overriding the default setting for
+ the current working language. A warning is issued if the setting
+ does not match the language default. If a range error occurs and
+ range checking is on, then a message is printed and evaluation of
+ the expression is aborted.
+
+`set check range warn'
+ Output messages when the GDB range checker detects a range error,
+ but attempt to evaluate the expression anyway. Evaluating the
+ expression may still be impossible for other reasons, such as
+ accessing memory that the process does not own (a typical example
+ from many Unix systems).
+
+`show range'
+ Show the current setting of the range checker, and whether or not
+ it is being set automatically by GDB.
+
+
+File: gdb.info, Node: Supported Languages, Next: Unsupported Languages, Prev: Checks, Up: Languages
+
+15.4 Supported Languages
+========================
+
+GDB supports C, C++, D, Objective-C, Fortran, Java, OpenCL C, Pascal,
+assembly, Modula-2, and Ada. Some GDB features may be used in
+expressions regardless of the language you use: the GDB `@' and `::'
+operators, and the `{type}addr' construct (*note Expressions:
+Expressions.) can be used with the constructs of any supported language.
+
+ The following sections detail to what degree each source language is
+supported by GDB. These sections are not meant to be language
+tutorials or references, but serve only as a reference guide to what the
+GDB expression parser accepts, and what input and output formats should
+look like for different languages. There are many good books written
+on each of these languages; please look to these for a language
+reference or tutorial.
+
+* Menu:
+
+* C:: C and C++
+* D:: D
+* Objective-C:: Objective-C
+* OpenCL C:: OpenCL C
+* Fortran:: Fortran
+* Pascal:: Pascal
+* Modula-2:: Modula-2
+* Ada:: Ada
+
+
+File: gdb.info, Node: C, Next: D, Up: Supported Languages
+
+15.4.1 C and C++
+----------------
+
+Since C and C++ are so closely related, many features of GDB apply to
+both languages. Whenever this is the case, we discuss those languages
+together.
+
+ The C++ debugging facilities are jointly implemented by the C++
+compiler and GDB. Therefore, to debug your C++ code effectively, you
+must compile your C++ programs with a supported C++ compiler, such as
+GNU `g++', or the HP ANSI C++ compiler (`aCC').
+
+* Menu:
+
+* C Operators:: C and C++ operators
+* C Constants:: C and C++ constants
+* C Plus Plus Expressions:: C++ expressions
+* C Defaults:: Default settings for C and C++
+* C Checks:: C and C++ type and range checks
+* Debugging C:: GDB and C
+* Debugging C Plus Plus:: GDB features for C++
+* Decimal Floating Point:: Numbers in Decimal Floating Point format
+
+
+File: gdb.info, Node: C Operators, Next: C Constants, Up: C
+
+15.4.1.1 C and C++ Operators
+............................
+
+Operators must be defined on values of specific types. For instance,
+`+' is defined on numbers, but not on structures. Operators are often
+defined on groups of types.
+
+ For the purposes of C and C++, the following definitions hold:
+
+ * _Integral types_ include `int' with any of its storage-class
+ specifiers; `char'; `enum'; and, for C++, `bool'.
+
+ * _Floating-point types_ include `float', `double', and `long
+ double' (if supported by the target platform).
+
+ * _Pointer types_ include all types defined as `(TYPE *)'.
+
+ * _Scalar types_ include all of the above.
+
+
+The following operators are supported. They are listed here in order
+of increasing precedence:
+
+`,'
+ The comma or sequencing operator. Expressions in a
+ comma-separated list are evaluated from left to right, with the
+ result of the entire expression being the last expression
+ evaluated.
+
+`='
+ Assignment. The value of an assignment expression is the value
+ assigned. Defined on scalar types.
+
+`OP='
+ Used in an expression of the form `A OP= B', and translated to
+ `A = A OP B'. `OP=' and `=' have the same precedence. OP is any
+ one of the operators `|', `^', `&', `<<', `>>', `+', `-', `*',
+ `/', `%'.
+
+`?:'
+ The ternary operator. `A ? B : C' can be thought of as: if A
+ then B else C. A should be of an integral type.
+
+`||'
+ Logical OR. Defined on integral types.
+
+`&&'
+ Logical AND. Defined on integral types.
+
+`|'
+ Bitwise OR. Defined on integral types.
+
+`^'
+ Bitwise exclusive-OR. Defined on integral types.
+
+`&'
+ Bitwise AND. Defined on integral types.
+
+`==, !='
+ Equality and inequality. Defined on scalar types. The value of
+ these expressions is 0 for false and non-zero for true.
+
+`<, >, <=, >='
+ Less than, greater than, less than or equal, greater than or equal.
+ Defined on scalar types. The value of these expressions is 0 for
+ false and non-zero for true.
+
+`<<, >>'
+ left shift, and right shift. Defined on integral types.
+
+`@'
+ The GDB "artificial array" operator (*note Expressions:
+ Expressions.).
+
+`+, -'
+ Addition and subtraction. Defined on integral types,
+ floating-point types and pointer types.
+
+`*, /, %'
+ Multiplication, division, and modulus. Multiplication and
+ division are defined on integral and floating-point types.
+ Modulus is defined on integral types.
+
+`++, --'
+ Increment and decrement. When appearing before a variable, the
+ operation is performed before the variable is used in an
+ expression; when appearing after it, the variable's value is used
+ before the operation takes place.
+
+`*'
+ Pointer dereferencing. Defined on pointer types. Same precedence
+ as `++'.
+
+`&'
+ Address operator. Defined on variables. Same precedence as `++'.
+
+ For debugging C++, GDB implements a use of `&' beyond what is
+ allowed in the C++ language itself: you can use `&(&REF)' to
+ examine the address where a C++ reference variable (declared with
+ `&REF') is stored.
+
+`-'
+ Negative. Defined on integral and floating-point types. Same
+ precedence as `++'.
+
+`!'
+ Logical negation. Defined on integral types. Same precedence as
+ `++'.
+
+`~'
+ Bitwise complement operator. Defined on integral types. Same
+ precedence as `++'.
+
+`., ->'
+ Structure member, and pointer-to-structure member. For
+ convenience, GDB regards the two as equivalent, choosing whether
+ to dereference a pointer based on the stored type information.
+ Defined on `struct' and `union' data.
+
+`.*, ->*'
+ Dereferences of pointers to members.
+
+`[]'
+ Array indexing. `A[I]' is defined as `*(A+I)'. Same precedence
+ as `->'.
+
+`()'
+ Function parameter list. Same precedence as `->'.
+
+`::'
+ C++ scope resolution operator. Defined on `struct', `union', and
+ `class' types.
+
+`::'
+ Doubled colons also represent the GDB scope operator (*note
+ Expressions: Expressions.). Same precedence as `::', above.
+
+ If an operator is redefined in the user code, GDB usually attempts
+to invoke the redefined version instead of using the operator's
+predefined meaning.
+
+
+File: gdb.info, Node: C Constants, Next: C Plus Plus Expressions, Prev: C Operators, Up: C
+
+15.4.1.2 C and C++ Constants
+............................
+
+GDB allows you to express the constants of C and C++ in the following
+ways:
+
+ * Integer constants are a sequence of digits. Octal constants are
+ specified by a leading `0' (i.e. zero), and hexadecimal constants
+ by a leading `0x' or `0X'. Constants may also end with a letter
+ `l', specifying that the constant should be treated as a `long'
+ value.
+
+ * Floating point constants are a sequence of digits, followed by a
+ decimal point, followed by a sequence of digits, and optionally
+ followed by an exponent. An exponent is of the form:
+ `e[[+]|-]NNN', where NNN is another sequence of digits. The `+'
+ is optional for positive exponents. A floating-point constant may
+ also end with a letter `f' or `F', specifying that the constant
+ should be treated as being of the `float' (as opposed to the
+ default `double') type; or with a letter `l' or `L', which
+ specifies a `long double' constant.
+
+ * Enumerated constants consist of enumerated identifiers, or their
+ integral equivalents.
+
+ * Character constants are a single character surrounded by single
+ quotes (`''), or a number--the ordinal value of the corresponding
+ character (usually its ASCII value). Within quotes, the single
+ character may be represented by a letter or by "escape sequences",
+ which are of the form `\NNN', where NNN is the octal representation
+ of the character's ordinal value; or of the form `\X', where `X'
+ is a predefined special character--for example, `\n' for newline.
+
+ Wide character constants can be written by prefixing a character
+ constant with `L', as in C. For example, `L'x'' is the wide form
+ of `x'. The target wide character set is used when computing the
+ value of this constant (*note Character Sets::).
+
+ * String constants are a sequence of character constants surrounded
+ by double quotes (`"'). Any valid character constant (as described
+ above) may appear. Double quotes within the string must be
+ preceded by a backslash, so for instance `"a\"b'c"' is a string of
+ five characters.
+
+ Wide string constants can be written by prefixing a string constant
+ with `L', as in C. The target wide character set is used when
+ computing the value of this constant (*note Character Sets::).
+
+ * Pointer constants are an integral value. You can also write
+ pointers to constants using the C operator `&'.
+
+ * Array constants are comma-separated lists surrounded by braces `{'
+ and `}'; for example, `{1,2,3}' is a three-element array of
+ integers, `{{1,2}, {3,4}, {5,6}}' is a three-by-two array, and
+ `{&"hi", &"there", &"fred"}' is a three-element array of pointers.
+
+
+File: gdb.info, Node: C Plus Plus Expressions, Next: C Defaults, Prev: C Constants, Up: C
+
+15.4.1.3 C++ Expressions
+........................
+
+GDB expression handling can interpret most C++ expressions.
+
+ _Warning:_ GDB can only debug C++ code if you use the proper
+ compiler and the proper debug format. Currently, GDB works best
+ when debugging C++ code that is compiled with the most recent
+ version of GCC possible. The DWARF debugging format is preferred;
+ GCC defaults to this on most popular platforms. Other compilers
+ and/or debug formats are likely to work badly or not at all when
+ using GDB to debug C++ code. *Note Compilation::.
+
+ 1. Member function calls are allowed; you can use expressions like
+
+ count = aml->GetOriginal(x, y)
+
+ 2. While a member function is active (in the selected stack frame),
+ your expressions have the same namespace available as the member
+ function; that is, GDB allows implicit references to the class
+ instance pointer `this' following the same rules as C++. `using'
+ declarations in the current scope are also respected by GDB.
+
+ 3. You can call overloaded functions; GDB resolves the function call
+ to the right definition, with some restrictions. GDB does not
+ perform overload resolution involving user-defined type
+ conversions, calls to constructors, or instantiations of templates
+ that do not exist in the program. It also cannot handle ellipsis
+ argument lists or default arguments.
+
+ It does perform integral conversions and promotions, floating-point
+ promotions, arithmetic conversions, pointer conversions,
+ conversions of class objects to base classes, and standard
+ conversions such as those of functions or arrays to pointers; it
+ requires an exact match on the number of function arguments.
+
+ Overload resolution is always performed, unless you have specified
+ `set overload-resolution off'. *Note GDB Features for C++:
+ Debugging C Plus Plus.
+
+ You must specify `set overload-resolution off' in order to use an
+ explicit function signature to call an overloaded function, as in
+ p 'foo(char,int)'('x', 13)
+
+ The GDB command-completion facility can simplify this; see *Note
+ Command Completion: Completion.
+
+ 4. GDB understands variables declared as C++ references; you can use
+ them in expressions just as you do in C++ source--they are
+ automatically dereferenced.
+
+ In the parameter list shown when GDB displays a frame, the values
+ of reference variables are not displayed (unlike other variables);
+ this avoids clutter, since references are often used for large
+ structures. The _address_ of a reference variable is always
+ shown, unless you have specified `set print address off'.
+
+ 5. GDB supports the C++ name resolution operator `::'--your
+ expressions can use it just as expressions in your program do.
+ Since one scope may be defined in another, you can use `::'
+ repeatedly if necessary, for example in an expression like
+ `SCOPE1::SCOPE2::NAME'. GDB also allows resolving name scope by
+ reference to source files, in both C and C++ debugging (*note
+ Program Variables: Variables.).
+
+ 6. GDB performs argument-dependent lookup, following the C++
+ specification.
+
+
+File: gdb.info, Node: C Defaults, Next: C Checks, Prev: C Plus Plus Expressions, Up: C
+
+15.4.1.4 C and C++ Defaults
+...........................
+
+If you allow GDB to set type and range checking automatically, they
+both default to `off' whenever the working language changes to C or
+C++. This happens regardless of whether you or GDB selects the working
+language.
+
+ If you allow GDB to set the language automatically, it recognizes
+source files whose names end with `.c', `.C', or `.cc', etc, and when
+GDB enters code compiled from one of these files, it sets the working
+language to C or C++. *Note Having GDB Infer the Source Language:
+Automatically, for further details.
+
+
+File: gdb.info, Node: C Checks, Next: Debugging C, Prev: C Defaults, Up: C
+
+15.4.1.5 C and C++ Type and Range Checks
+........................................
+
+By default, when GDB parses C or C++ expressions, type checking is not
+used. However, if you turn type checking on, GDB considers two
+variables type equivalent if:
+
+ * The two variables are structured and have the same structure,
+ union, or enumerated tag.
+
+ * The two variables have the same type name, or types that have been
+ declared equivalent through `typedef'.
+
+
+ Range checking, if turned on, is done on mathematical operations.
+Array indices are not checked, since they are often used to index a
+pointer that is not itself an array.
+
+
+File: gdb.info, Node: Debugging C, Next: Debugging C Plus Plus, Prev: C Checks, Up: C
+
+15.4.1.6 GDB and C
+..................
+
+The `set print union' and `show print union' commands apply to the
+`union' type. When set to `on', any `union' that is inside a `struct'
+or `class' is also printed. Otherwise, it appears as `{...}'.
+
+ The `@' operator aids in the debugging of dynamic arrays, formed
+with pointers and a memory allocation function. *Note Expressions:
+Expressions.
+
+
+File: gdb.info, Node: Debugging C Plus Plus, Next: Decimal Floating Point, Prev: Debugging C, Up: C
+
+15.4.1.7 GDB Features for C++
+.............................
+
+Some GDB commands are particularly useful with C++, and some are
+designed specifically for use with C++. Here is a summary:
+
+`breakpoint menus'
+ When you want a breakpoint in a function whose name is overloaded,
+ GDB has the capability to display a menu of possible breakpoint
+ locations to help you specify which function definition you want.
+ *Note Ambiguous Expressions: Ambiguous Expressions.
+
+`rbreak REGEX'
+ Setting breakpoints using regular expressions is helpful for
+ setting breakpoints on overloaded functions that are not members
+ of any special classes. *Note Setting Breakpoints: Set Breaks.
+
+`catch throw'
+`catch catch'
+ Debug C++ exception handling using these commands. *Note Setting
+ Catchpoints: Set Catchpoints.
+
+`ptype TYPENAME'
+ Print inheritance relationships as well as other information for
+ type TYPENAME. *Note Examining the Symbol Table: Symbols.
+
+`set print demangle'
+`show print demangle'
+`set print asm-demangle'
+`show print asm-demangle'
+ Control whether C++ symbols display in their source form, both when
+ displaying code as C++ source and when displaying disassemblies.
+ *Note Print Settings: Print Settings.
+
+`set print object'
+`show print object'
+ Choose whether to print derived (actual) or declared types of
+ objects. *Note Print Settings: Print Settings.
+
+`set print vtbl'
+`show print vtbl'
+ Control the format for printing virtual function tables. *Note
+ Print Settings: Print Settings. (The `vtbl' commands do not work
+ on programs compiled with the HP ANSI C++ compiler (`aCC').)
+
+`set overload-resolution on'
+ Enable overload resolution for C++ expression evaluation. The
+ default is on. For overloaded functions, GDB evaluates the
+ arguments and searches for a function whose signature matches the
+ argument types, using the standard C++ conversion rules (see *Note
+ C++ Expressions: C Plus Plus Expressions, for details). If it
+ cannot find a match, it emits a message.
+
+`set overload-resolution off'
+ Disable overload resolution for C++ expression evaluation. For
+ overloaded functions that are not class member functions, GDB
+ chooses the first function of the specified name that it finds in
+ the symbol table, whether or not its arguments are of the correct
+ type. For overloaded functions that are class member functions,
+ GDB searches for a function whose signature _exactly_ matches the
+ argument types.
+
+`show overload-resolution'
+ Show the current setting of overload resolution.
+
+`Overloaded symbol names'
+ You can specify a particular definition of an overloaded symbol,
+ using the same notation that is used to declare such symbols in
+ C++: type `SYMBOL(TYPES)' rather than just SYMBOL. You can also
+ use the GDB command-line word completion facilities to list the
+ available choices, or to finish the type list for you. *Note
+ Command Completion: Completion, for details on how to do this.
+
+
+File: gdb.info, Node: Decimal Floating Point, Prev: Debugging C Plus Plus, Up: C
+
+15.4.1.8 Decimal Floating Point format
+......................................
+
+GDB can examine, set and perform computations with numbers in decimal
+floating point format, which in the C language correspond to the
+`_Decimal32', `_Decimal64' and `_Decimal128' types as specified by the
+extension to support decimal floating-point arithmetic.
+
+ There are two encodings in use, depending on the architecture: BID
+(Binary Integer Decimal) for x86 and x86-64, and DPD (Densely Packed
+Decimal) for PowerPC. GDB will use the appropriate encoding for the
+configured target.
+
+ Because of a limitation in `libdecnumber', the library used by GDB
+to manipulate decimal floating point numbers, it is not possible to
+convert (using a cast, for example) integers wider than 32-bit to
+decimal float.
+
+ In addition, in order to imitate GDB's behaviour with binary floating
+point computations, error checking in decimal float operations ignores
+underflow, overflow and divide by zero exceptions.
+
+ In the PowerPC architecture, GDB provides a set of pseudo-registers
+to inspect `_Decimal128' values stored in floating point registers.
+See *Note PowerPC: PowerPC. for more details.
+
+
+File: gdb.info, Node: D, Next: Objective-C, Prev: C, Up: Supported Languages
+
+15.4.2 D
+--------
+
+GDB can be used to debug programs written in D and compiled with GDC,
+LDC or DMD compilers. Currently GDB supports only one D specific
+feature -- dynamic arrays.
+
+
+File: gdb.info, Node: Objective-C, Next: OpenCL C, Prev: D, Up: Supported Languages
+
+15.4.3 Objective-C
+------------------
+
+This section provides information about some commands and command
+options that are useful for debugging Objective-C code. See also *Note
+info classes: Symbols, and *Note info selectors: Symbols, for a few
+more commands specific to Objective-C support.
+
+* Menu:
+
+* Method Names in Commands::
+* The Print Command with Objective-C::
+
+
+File: gdb.info, Node: Method Names in Commands, Next: The Print Command with Objective-C, Up: Objective-C
+
+15.4.3.1 Method Names in Commands
+.................................
+
+The following commands have been extended to accept Objective-C method
+names as line specifications:
+
+ * `clear'
+
+ * `break'
+
+ * `info line'
+
+ * `jump'
+
+ * `list'
+
+ A fully qualified Objective-C method name is specified as
+
+ -[CLASS METHODNAME]
+
+ where the minus sign is used to indicate an instance method and a
+plus sign (not shown) is used to indicate a class method. The class
+name CLASS and method name METHODNAME are enclosed in brackets, similar
+to the way messages are specified in Objective-C source code. For
+example, to set a breakpoint at the `create' instance method of class
+`Fruit' in the program currently being debugged, enter:
+
+ break -[Fruit create]
+
+ To list ten program lines around the `initialize' class method,
+enter:
+
+ list +[NSText initialize]
+
+ In the current version of GDB, the plus or minus sign is required.
+In future versions of GDB, the plus or minus sign will be optional, but
+you can use it to narrow the search. It is also possible to specify
+just a method name:
+
+ break create
+
+ You must specify the complete method name, including any colons. If
+your program's source files contain more than one `create' method,
+you'll be presented with a numbered list of classes that implement that
+method. Indicate your choice by number, or type `0' to exit if none
+apply.
+
+ As another example, to clear a breakpoint established at the
+`makeKeyAndOrderFront:' method of the `NSWindow' class, enter:
+
+ clear -[NSWindow makeKeyAndOrderFront:]
+
+
+File: gdb.info, Node: The Print Command with Objective-C, Prev: Method Names in Commands, Up: Objective-C
+
+15.4.3.2 The Print Command With Objective-C
+...........................................
+
+The print command has also been extended to accept methods. For
+example:
+
+ print -[OBJECT hash]
+
+will tell GDB to send the `hash' message to OBJECT and print the
+result. Also, an additional command has been added, `print-object' or
+`po' for short, which is meant to print the description of an object.
+However, this command may only work with certain Objective-C libraries
+that have a particular hook function, `_NSPrintForDebugger', defined.
+
+
+File: gdb.info, Node: OpenCL C, Next: Fortran, Prev: Objective-C, Up: Supported Languages
+
+15.4.4 OpenCL C
+---------------
+
+This section provides information about GDBs OpenCL C support.
+
+* Menu:
+
+* OpenCL C Datatypes::
+* OpenCL C Expressions::
+* OpenCL C Operators::
+
+
+File: gdb.info, Node: OpenCL C Datatypes, Next: OpenCL C Expressions, Up: OpenCL C
+
+15.4.4.1 OpenCL C Datatypes
+...........................
+
+GDB supports the builtin scalar and vector datatypes specified by
+OpenCL 1.1. In addition the half- and double-precision floating point
+data types of the `cl_khr_fp16' and `cl_khr_fp64' OpenCL extensions are
+also known to GDB.
+
+
+File: gdb.info, Node: OpenCL C Expressions, Next: OpenCL C Operators, Prev: OpenCL C Datatypes, Up: OpenCL C
+
+15.4.4.2 OpenCL C Expressions
+.............................
+
+GDB supports accesses to vector components including the access as
+lvalue where possible. Since OpenCL C is based on C99 most C
+expressions supported by GDB can be used as well.
+
+
+File: gdb.info, Node: OpenCL C Operators, Prev: OpenCL C Expressions, Up: OpenCL C
+
+15.4.4.3 OpenCL C Operators
+...........................
+
+GDB supports the operators specified by OpenCL 1.1 for scalar and
+vector data types.
+
+
+File: gdb.info, Node: Fortran, Next: Pascal, Prev: OpenCL C, Up: Supported Languages
+
+15.4.5 Fortran
+--------------
+
+GDB can be used to debug programs written in Fortran, but it currently
+supports only the features of Fortran 77 language.
+
+ Some Fortran compilers (GNU Fortran 77 and Fortran 95 compilers
+among them) append an underscore to the names of variables and
+functions. When you debug programs compiled by those compilers, you
+will need to refer to variables and functions with a trailing
+underscore.
+
+* Menu:
+
+* Fortran Operators:: Fortran operators and expressions
+* Fortran Defaults:: Default settings for Fortran
+* Special Fortran Commands:: Special GDB commands for Fortran
+
+
+File: gdb.info, Node: Fortran Operators, Next: Fortran Defaults, Up: Fortran
+
+15.4.5.1 Fortran Operators and Expressions
+..........................................
+
+Operators must be defined on values of specific types. For instance,
+`+' is defined on numbers, but not on characters or other non-
+arithmetic types. Operators are often defined on groups of types.
+
+`**'
+ The exponentiation operator. It raises the first operand to the
+ power of the second one.
+
+`:'
+ The range operator. Normally used in the form of array(low:high)
+ to represent a section of array.
+
+`%'
+ The access component operator. Normally used to access elements
+ in derived types. Also suitable for unions. As unions aren't
+ part of regular Fortran, this can only happen when accessing a
+ register that uses a gdbarch-defined union type.
+
+
+File: gdb.info, Node: Fortran Defaults, Next: Special Fortran Commands, Prev: Fortran Operators, Up: Fortran
+
+15.4.5.2 Fortran Defaults
+.........................
+
+Fortran symbols are usually case-insensitive, so GDB by default uses
+case-insensitive matches for Fortran symbols. You can change that with
+the `set case-insensitive' command, see *Note Symbols::, for the
+details.
+
+
+File: gdb.info, Node: Special Fortran Commands, Prev: Fortran Defaults, Up: Fortran
+
+15.4.5.3 Special Fortran Commands
+.................................
+
+GDB has some commands to support Fortran-specific features, such as
+displaying common blocks.
+
+`info common [COMMON-NAME]'
+ This command prints the values contained in the Fortran `COMMON'
+ block whose name is COMMON-NAME. With no argument, the names of
+ all `COMMON' blocks visible at the current program location are
+ printed.
+
+
+File: gdb.info, Node: Pascal, Next: Modula-2, Prev: Fortran, Up: Supported Languages
+
+15.4.6 Pascal
+-------------
+
+Debugging Pascal programs which use sets, subranges, file variables, or
+nested functions does not currently work. GDB does not support
+entering expressions, printing values, or similar features using Pascal
+syntax.
+
+ The Pascal-specific command `set print pascal_static-members'
+controls whether static members of Pascal objects are displayed. *Note
+pascal_static-members: Print Settings.
+
+
+File: gdb.info, Node: Modula-2, Next: Ada, Prev: Pascal, Up: Supported Languages
+
+15.4.7 Modula-2
+---------------
+
+The extensions made to GDB to support Modula-2 only support output from
+the GNU Modula-2 compiler (which is currently being developed). Other
+Modula-2 compilers are not currently supported, and attempting to debug
+executables produced by them is most likely to give an error as GDB
+reads in the executable's symbol table.
+
+* Menu:
+
+* M2 Operators:: Built-in operators
+* Built-In Func/Proc:: Built-in functions and procedures
+* M2 Constants:: Modula-2 constants
+* M2 Types:: Modula-2 types
+* M2 Defaults:: Default settings for Modula-2
+* Deviations:: Deviations from standard Modula-2
+* M2 Checks:: Modula-2 type and range checks
+* M2 Scope:: The scope operators `::' and `.'
+* GDB/M2:: GDB and Modula-2
+
+
+File: gdb.info, Node: M2 Operators, Next: Built-In Func/Proc, Up: Modula-2
+
+15.4.7.1 Operators
+..................
+
+Operators must be defined on values of specific types. For instance,
+`+' is defined on numbers, but not on structures. Operators are often
+defined on groups of types. For the purposes of Modula-2, the
+following definitions hold:
+
+ * _Integral types_ consist of `INTEGER', `CARDINAL', and their
+ subranges.
+
+ * _Character types_ consist of `CHAR' and its subranges.
+
+ * _Floating-point types_ consist of `REAL'.
+
+ * _Pointer types_ consist of anything declared as `POINTER TO TYPE'.
+
+ * _Scalar types_ consist of all of the above.
+
+ * _Set types_ consist of `SET' and `BITSET' types.
+
+ * _Boolean types_ consist of `BOOLEAN'.
+
+The following operators are supported, and appear in order of
+increasing precedence:
+
+`,'
+ Function argument or array index separator.
+
+`:='
+ Assignment. The value of VAR `:=' VALUE is VALUE.
+
+`<, >'
+ Less than, greater than on integral, floating-point, or enumerated
+ types.
+
+`<=, >='
+ Less than or equal to, greater than or equal to on integral,
+ floating-point and enumerated types, or set inclusion on set
+ types. Same precedence as `<'.
+
+`=, <>, #'
+ Equality and two ways of expressing inequality, valid on scalar
+ types. Same precedence as `<'. In GDB scripts, only `<>' is
+ available for inequality, since `#' conflicts with the script
+ comment character.
+
+`IN'
+ Set membership. Defined on set types and the types of their
+ members. Same precedence as `<'.
+
+`OR'
+ Boolean disjunction. Defined on boolean types.
+
+`AND, &'
+ Boolean conjunction. Defined on boolean types.
+
+`@'
+ The GDB "artificial array" operator (*note Expressions:
+ Expressions.).
+
+`+, -'
+ Addition and subtraction on integral and floating-point types, or
+ union and difference on set types.
+
+`*'
+ Multiplication on integral and floating-point types, or set
+ intersection on set types.
+
+`/'
+ Division on floating-point types, or symmetric set difference on
+ set types. Same precedence as `*'.
+
+`DIV, MOD'
+ Integer division and remainder. Defined on integral types. Same
+ precedence as `*'.
+
+`-'
+ Negative. Defined on `INTEGER' and `REAL' data.
+
+`^'
+ Pointer dereferencing. Defined on pointer types.
+
+`NOT'
+ Boolean negation. Defined on boolean types. Same precedence as
+ `^'.
+
+`.'
+ `RECORD' field selector. Defined on `RECORD' data. Same
+ precedence as `^'.
+
+`[]'
+ Array indexing. Defined on `ARRAY' data. Same precedence as `^'.
+
+`()'
+ Procedure argument list. Defined on `PROCEDURE' objects. Same
+ precedence as `^'.
+
+`::, .'
+ GDB and Modula-2 scope operators.
+
+ _Warning:_ Set expressions and their operations are not yet
+ supported, so GDB treats the use of the operator `IN', or the use
+ of operators `+', `-', `*', `/', `=', , `<>', `#', `<=', and `>='
+ on sets as an error.
+
+
+File: gdb.info, Node: Built-In Func/Proc, Next: M2 Constants, Prev: M2 Operators, Up: Modula-2
+
+15.4.7.2 Built-in Functions and Procedures
+..........................................
+
+Modula-2 also makes available several built-in procedures and functions.
+In describing these, the following metavariables are used:
+
+A
+ represents an `ARRAY' variable.
+
+C
+ represents a `CHAR' constant or variable.
+
+I
+ represents a variable or constant of integral type.
+
+M
+ represents an identifier that belongs to a set. Generally used in
+ the same function with the metavariable S. The type of S should
+ be `SET OF MTYPE' (where MTYPE is the type of M).
+
+N
+ represents a variable or constant of integral or floating-point
+ type.
+
+R
+ represents a variable or constant of floating-point type.
+
+T
+ represents a type.
+
+V
+ represents a variable.
+
+X
+ represents a variable or constant of one of many types. See the
+ explanation of the function for details.
+
+ All Modula-2 built-in procedures also return a result, described
+below.
+
+`ABS(N)'
+ Returns the absolute value of N.
+
+`CAP(C)'
+ If C is a lower case letter, it returns its upper case equivalent,
+ otherwise it returns its argument.
+
+`CHR(I)'
+ Returns the character whose ordinal value is I.
+
+`DEC(V)'
+ Decrements the value in the variable V by one. Returns the new
+ value.
+
+`DEC(V,I)'
+ Decrements the value in the variable V by I. Returns the new
+ value.
+
+`EXCL(M,S)'
+ Removes the element M from the set S. Returns the new set.
+
+`FLOAT(I)'
+ Returns the floating point equivalent of the integer I.
+
+`HIGH(A)'
+ Returns the index of the last member of A.
+
+`INC(V)'
+ Increments the value in the variable V by one. Returns the new
+ value.
+
+`INC(V,I)'
+ Increments the value in the variable V by I. Returns the new
+ value.
+
+`INCL(M,S)'
+ Adds the element M to the set S if it is not already there.
+ Returns the new set.
+
+`MAX(T)'
+ Returns the maximum value of the type T.
+
+`MIN(T)'
+ Returns the minimum value of the type T.
+
+`ODD(I)'
+ Returns boolean TRUE if I is an odd number.
+
+`ORD(X)'
+ Returns the ordinal value of its argument. For example, the
+ ordinal value of a character is its ASCII value (on machines
+ supporting the ASCII character set). X must be of an ordered
+ type, which include integral, character and enumerated types.
+
+`SIZE(X)'
+ Returns the size of its argument. X can be a variable or a type.
+
+`TRUNC(R)'
+ Returns the integral part of R.
+
+`TSIZE(X)'
+ Returns the size of its argument. X can be a variable or a type.
+
+`VAL(T,I)'
+ Returns the member of the type T whose ordinal value is I.
+
+ _Warning:_ Sets and their operations are not yet supported, so
+ GDB treats the use of procedures `INCL' and `EXCL' as an error.
+
+
+File: gdb.info, Node: M2 Constants, Next: M2 Types, Prev: Built-In Func/Proc, Up: Modula-2
+
+15.4.7.3 Constants
+..................
+
+GDB allows you to express the constants of Modula-2 in the following
+ways:
+
+ * Integer constants are simply a sequence of digits. When used in an
+ expression, a constant is interpreted to be type-compatible with
+ the rest of the expression. Hexadecimal integers are specified by
+ a trailing `H', and octal integers by a trailing `B'.
+
+ * Floating point constants appear as a sequence of digits, followed
+ by a decimal point and another sequence of digits. An optional
+ exponent can then be specified, in the form `E[+|-]NNN', where
+ `[+|-]NNN' is the desired exponent. All of the digits of the
+ floating point constant must be valid decimal (base 10) digits.
+
+ * Character constants consist of a single character enclosed by a
+ pair of like quotes, either single (`'') or double (`"'). They may
+ also be expressed by their ordinal value (their ASCII value,
+ usually) followed by a `C'.
+
+ * String constants consist of a sequence of characters enclosed by a
+ pair of like quotes, either single (`'') or double (`"'). Escape
+ sequences in the style of C are also allowed. *Note C and C++
+ Constants: C Constants, for a brief explanation of escape
+ sequences.
+
+ * Enumerated constants consist of an enumerated identifier.
+
+ * Boolean constants consist of the identifiers `TRUE' and `FALSE'.
+
+ * Pointer constants consist of integral values only.
+
+ * Set constants are not yet supported.
+
+
+File: gdb.info, Node: M2 Types, Next: M2 Defaults, Prev: M2 Constants, Up: Modula-2
+
+15.4.7.4 Modula-2 Types
+.......................
+
+Currently GDB can print the following data types in Modula-2 syntax:
+array types, record types, set types, pointer types, procedure types,
+enumerated types, subrange types and base types. You can also print
+the contents of variables declared using these type. This section
+gives a number of simple source code examples together with sample GDB
+sessions.
+
+ The first example contains the following section of code:
+
+ VAR
+ s: SET OF CHAR ;
+ r: [20..40] ;
+
+and you can request GDB to interrogate the type and value of `r' and
+`s'.
+
+ (gdb) print s
+ {'A'..'C', 'Z'}
+ (gdb) ptype s
+ SET OF CHAR
+ (gdb) print r
+ 21
+ (gdb) ptype r
+ [20..40]
+
+Likewise if your source code declares `s' as:
+
+ VAR
+ s: SET ['A'..'Z'] ;
+
+then you may query the type of `s' by:
+
+ (gdb) ptype s
+ type = SET ['A'..'Z']
+
+Note that at present you cannot interactively manipulate set
+expressions using the debugger.
+
+ The following example shows how you might declare an array in
+Modula-2 and how you can interact with GDB to print its type and
+contents:
+
+ VAR
+ s: ARRAY [-10..10] OF CHAR ;
+
+ (gdb) ptype s
+ ARRAY [-10..10] OF CHAR
+
+ Note that the array handling is not yet complete and although the
+type is printed correctly, expression handling still assumes that all
+arrays have a lower bound of zero and not `-10' as in the example above.
+
+ Here are some more type related Modula-2 examples:
+
+ TYPE
+ colour = (blue, red, yellow, green) ;
+ t = [blue..yellow] ;
+ VAR
+ s: t ;
+ BEGIN
+ s := blue ;
+
+The GDB interaction shows how you can query the data type and value of
+a variable.
+
+ (gdb) print s
+ $1 = blue
+ (gdb) ptype t
+ type = [blue..yellow]
+
+In this example a Modula-2 array is declared and its contents
+displayed. Observe that the contents are written in the same way as
+their `C' counterparts.
+
+ VAR
+ s: ARRAY [1..5] OF CARDINAL ;
+ BEGIN
+ s[1] := 1 ;
+
+ (gdb) print s
+ $1 = {1, 0, 0, 0, 0}
+ (gdb) ptype s
+ type = ARRAY [1..5] OF CARDINAL
+
+ The Modula-2 language interface to GDB also understands pointer
+types as shown in this example:
+
+ VAR
+ s: POINTER TO ARRAY [1..5] OF CARDINAL ;
+ BEGIN
+ NEW(s) ;
+ s^[1] := 1 ;
+
+and you can request that GDB describes the type of `s'.
+
+ (gdb) ptype s
+ type = POINTER TO ARRAY [1..5] OF CARDINAL
+
+ GDB handles compound types as we can see in this example. Here we
+combine array types, record types, pointer types and subrange types:
+
+ TYPE
+ foo = RECORD
+ f1: CARDINAL ;
+ f2: CHAR ;
+ f3: myarray ;
+ END ;
+
+ myarray = ARRAY myrange OF CARDINAL ;
+ myrange = [-2..2] ;
+ VAR
+ s: POINTER TO ARRAY myrange OF foo ;
+
+and you can ask GDB to describe the type of `s' as shown below.
+
+ (gdb) ptype s
+ type = POINTER TO ARRAY [-2..2] OF foo = RECORD
+ f1 : CARDINAL;
+ f2 : CHAR;
+ f3 : ARRAY [-2..2] OF CARDINAL;
+ END
+
+
+File: gdb.info, Node: M2 Defaults, Next: Deviations, Prev: M2 Types, Up: Modula-2
+
+15.4.7.5 Modula-2 Defaults
+..........................
+
+If type and range checking are set automatically by GDB, they both
+default to `on' whenever the working language changes to Modula-2.
+This happens regardless of whether you or GDB selected the working
+language.
+
+ If you allow GDB to set the language automatically, then entering
+code compiled from a file whose name ends with `.mod' sets the working
+language to Modula-2. *Note Having GDB Infer the Source Language:
+Automatically, for further details.
+
+
+File: gdb.info, Node: Deviations, Next: M2 Checks, Prev: M2 Defaults, Up: Modula-2
+
+15.4.7.6 Deviations from Standard Modula-2
+..........................................
+
+A few changes have been made to make Modula-2 programs easier to debug.
+This is done primarily via loosening its type strictness:
+
+ * Unlike in standard Modula-2, pointer constants can be formed by
+ integers. This allows you to modify pointer variables during
+ debugging. (In standard Modula-2, the actual address contained in
+ a pointer variable is hidden from you; it can only be modified
+ through direct assignment to another pointer variable or
+ expression that returned a pointer.)
+
+ * C escape sequences can be used in strings and characters to
+ represent non-printable characters. GDB prints out strings with
+ these escape sequences embedded. Single non-printable characters
+ are printed using the `CHR(NNN)' format.
+
+ * The assignment operator (`:=') returns the value of its right-hand
+ argument.
+
+ * All built-in procedures both modify _and_ return their argument.
+
+
+File: gdb.info, Node: M2 Checks, Next: M2 Scope, Prev: Deviations, Up: Modula-2
+
+15.4.7.7 Modula-2 Type and Range Checks
+.......................................
+
+ _Warning:_ in this release, GDB does not yet perform type or range
+ checking.
+
+ GDB considers two Modula-2 variables type equivalent if:
+
+ * They are of types that have been declared equivalent via a `TYPE
+ T1 = T2' statement
+
+ * They have been declared on the same line. (Note: This is true of
+ the GNU Modula-2 compiler, but it may not be true of other
+ compilers.)
+
+ As long as type checking is enabled, any attempt to combine variables
+whose types are not equivalent is an error.
+
+ Range checking is done on all mathematical operations, assignment,
+array index bounds, and all built-in functions and procedures.
+
+
+File: gdb.info, Node: M2 Scope, Next: GDB/M2, Prev: M2 Checks, Up: Modula-2
+
+15.4.7.8 The Scope Operators `::' and `.'
+.........................................
+
+There are a few subtle differences between the Modula-2 scope operator
+(`.') and the GDB scope operator (`::'). The two have similar syntax:
+
+
+ MODULE . ID
+ SCOPE :: ID
+
+where SCOPE is the name of a module or a procedure, MODULE the name of
+a module, and ID is any declared identifier within your program, except
+another module.
+
+ Using the `::' operator makes GDB search the scope specified by
+SCOPE for the identifier ID. If it is not found in the specified
+scope, then GDB searches all scopes enclosing the one specified by
+SCOPE.
+
+ Using the `.' operator makes GDB search the current scope for the
+identifier specified by ID that was imported from the definition module
+specified by MODULE. With this operator, it is an error if the
+identifier ID was not imported from definition module MODULE, or if ID
+is not an identifier in MODULE.
+
+
+File: gdb.info, Node: GDB/M2, Prev: M2 Scope, Up: Modula-2
+
+15.4.7.9 GDB and Modula-2
+.........................
+
+Some GDB commands have little use when debugging Modula-2 programs.
+Five subcommands of `set print' and `show print' apply specifically to
+C and C++: `vtbl', `demangle', `asm-demangle', `object', and `union'.
+The first four apply to C++, and the last to the C `union' type, which
+has no direct analogue in Modula-2.
+
+ The `@' operator (*note Expressions: Expressions.), while available
+with any language, is not useful with Modula-2. Its intent is to aid
+the debugging of "dynamic arrays", which cannot be created in Modula-2
+as they can in C or C++. However, because an address can be specified
+by an integral constant, the construct `{TYPE}ADREXP' is still useful.
+
+ In GDB scripts, the Modula-2 inequality operator `#' is interpreted
+as the beginning of a comment. Use `<>' instead.
+
+
+File: gdb.info, Node: Ada, Prev: Modula-2, Up: Supported Languages
+
+15.4.8 Ada
+----------
+
+The extensions made to GDB for Ada only support output from the GNU Ada
+(GNAT) compiler. Other Ada compilers are not currently supported, and
+attempting to debug executables produced by them is most likely to be
+difficult.
+
+* Menu:
+
+* Ada Mode Intro:: General remarks on the Ada syntax
+ and semantics supported by Ada mode
+ in GDB.
+* Omissions from Ada:: Restrictions on the Ada expression syntax.
+* Additions to Ada:: Extensions of the Ada expression syntax.
+* Stopping Before Main Program:: Debugging the program during elaboration.
+* Ada Tasks:: Listing and setting breakpoints in tasks.
+* Ada Tasks and Core Files:: Tasking Support when Debugging Core Files
+* Ravenscar Profile:: Tasking Support when using the Ravenscar
+ Profile
+* Ada Glitches:: Known peculiarities of Ada mode.
+
+
+File: gdb.info, Node: Ada Mode Intro, Next: Omissions from Ada, Up: Ada
+
+15.4.8.1 Introduction
+.....................
+
+The Ada mode of GDB supports a fairly large subset of Ada expression
+syntax, with some extensions. The philosophy behind the design of this
+subset is
+
+ * That GDB should provide basic literals and access to operations for
+ arithmetic, dereferencing, field selection, indexing, and
+ subprogram calls, leaving more sophisticated computations to
+ subprograms written into the program (which therefore may be
+ called from GDB).
+
+ * That type safety and strict adherence to Ada language restrictions
+ are not particularly important to the GDB user.
+
+ * That brevity is important to the GDB user.
+
+ Thus, for brevity, the debugger acts as if all names declared in
+user-written packages are directly visible, even if they are not visible
+according to Ada rules, thus making it unnecessary to fully qualify most
+names with their packages, regardless of context. Where this causes
+ambiguity, GDB asks the user's intent.
+
+ The debugger will start in Ada mode if it detects an Ada main
+program. As for other languages, it will enter Ada mode when stopped
+in a program that was translated from an Ada source file.
+
+ While in Ada mode, you may use `-' for comments. This is useful
+mostly for documenting command files. The standard GDB comment (`#')
+still works at the beginning of a line in Ada mode, but not in the
+middle (to allow based literals).
+
+ The debugger supports limited overloading. Given a subprogram call
+in which the function symbol has multiple definitions, it will use the
+number of actual parameters and some information about their types to
+attempt to narrow the set of definitions. It also makes very limited
+use of context, preferring procedures to functions in the context of
+the `call' command, and functions to procedures elsewhere.
+
+
+File: gdb.info, Node: Omissions from Ada, Next: Additions to Ada, Prev: Ada Mode Intro, Up: Ada
+
+15.4.8.2 Omissions from Ada
+...........................
+
+Here are the notable omissions from the subset:
+
+ * Only a subset of the attributes are supported:
+
+ - 'First, 'Last, and 'Length on array objects (not on types
+ and subtypes).
+
+ - 'Min and 'Max.
+
+ - 'Pos and 'Val.
+
+ - 'Tag.
+
+ - 'Range on array objects (not subtypes), but only as the right
+ operand of the membership (`in') operator.
+
+ - 'Access, 'Unchecked_Access, and 'Unrestricted_Access (a GNAT
+ extension).
+
+ - 'Address.
+
+ * The names in `Characters.Latin_1' are not available and
+ concatenation is not implemented. Thus, escape characters in
+ strings are not currently available.
+
+ * Equality tests (`=' and `/=') on arrays test for bitwise equality
+ of representations. They will generally work correctly for
+ strings and arrays whose elements have integer or enumeration
+ types. They may not work correctly for arrays whose element types
+ have user-defined equality, for arrays of real values (in
+ particular, IEEE-conformant floating point, because of negative
+ zeroes and NaNs), and for arrays whose elements contain unused
+ bits with indeterminate values.
+
+ * The other component-by-component array operations (`and', `or',
+ `xor', `not', and relational tests other than equality) are not
+ implemented.
+
+ * There is limited support for array and record aggregates. They are
+ permitted only on the right sides of assignments, as in these
+ examples:
+
+ (gdb) set An_Array := (1, 2, 3, 4, 5, 6)
+ (gdb) set An_Array := (1, others => 0)
+ (gdb) set An_Array := (0|4 => 1, 1..3 => 2, 5 => 6)
+ (gdb) set A_2D_Array := ((1, 2, 3), (4, 5, 6), (7, 8, 9))
+ (gdb) set A_Record := (1, "Peter", True);
+ (gdb) set A_Record := (Name => "Peter", Id => 1, Alive => True)
+
+ Changing a discriminant's value by assigning an aggregate has an
+ undefined effect if that discriminant is used within the record.
+ However, you can first modify discriminants by directly assigning
+ to them (which normally would not be allowed in Ada), and then
+ performing an aggregate assignment. For example, given a variable
+ `A_Rec' declared to have a type such as:
+
+ type Rec (Len : Small_Integer := 0) is record
+ Id : Integer;
+ Vals : IntArray (1 .. Len);
+ end record;
+
+ you can assign a value with a different size of `Vals' with two
+ assignments:
+
+ (gdb) set A_Rec.Len := 4
+ (gdb) set A_Rec := (Id => 42, Vals => (1, 2, 3, 4))
+
+ As this example also illustrates, GDB is very loose about the usual
+ rules concerning aggregates. You may leave out some of the
+ components of an array or record aggregate (such as the `Len'
+ component in the assignment to `A_Rec' above); they will retain
+ their original values upon assignment. You may freely use dynamic
+ values as indices in component associations. You may even use
+ overlapping or redundant component associations, although which
+ component values are assigned in such cases is not defined.
+
+ * Calls to dispatching subprograms are not implemented.
+
+ * The overloading algorithm is much more limited (i.e., less
+ selective) than that of real Ada. It makes only limited use of
+ the context in which a subexpression appears to resolve its
+ meaning, and it is much looser in its rules for allowing type
+ matches. As a result, some function calls will be ambiguous, and
+ the user will be asked to choose the proper resolution.
+
+ * The `new' operator is not implemented.
+
+ * Entry calls are not implemented.
+
+ * Aside from printing, arithmetic operations on the native VAX
+ floating-point formats are not supported.
+
+ * It is not possible to slice a packed array.
+
+ * The names `True' and `False', when not part of a qualified name,
+ are interpreted as if implicitly prefixed by `Standard',
+ regardless of context. Should your program redefine these names
+ in a package or procedure (at best a dubious practice), you will
+ have to use fully qualified names to access their new definitions.
+
+
+File: gdb.info, Node: Additions to Ada, Next: Stopping Before Main Program, Prev: Omissions from Ada, Up: Ada
+
+15.4.8.3 Additions to Ada
+.........................
+
+As it does for other languages, GDB makes certain generic extensions to
+Ada (*note Expressions::):
+
+ * If the expression E is a variable residing in memory (typically a
+ local variable or array element) and N is a positive integer, then
+ `E@N' displays the values of E and the N-1 adjacent variables
+ following it in memory as an array. In Ada, this operator is
+ generally not necessary, since its prime use is in displaying
+ parts of an array, and slicing will usually do this in Ada.
+ However, there are occasional uses when debugging programs in
+ which certain debugging information has been optimized away.
+
+ * `B::VAR' means "the variable named VAR that appears in function or
+ file B." When B is a file name, you must typically surround it in
+ single quotes.
+
+ * The expression `{TYPE} ADDR' means "the variable of type TYPE that
+ appears at address ADDR."
+
+ * A name starting with `$' is a convenience variable (*note
+ Convenience Vars::) or a machine register (*note Registers::).
+
+ In addition, GDB provides a few other shortcuts and outright
+additions specific to Ada:
+
+ * The assignment statement is allowed as an expression, returning
+ its right-hand operand as its value. Thus, you may enter
+
+ (gdb) set x := y + 3
+ (gdb) print A(tmp := y + 1)
+
+ * The semicolon is allowed as an "operator," returning as its value
+ the value of its right-hand operand. This allows, for example,
+ complex conditional breaks:
+
+ (gdb) break f
+ (gdb) condition 1 (report(i); k += 1; A(k) > 100)
+
+ * Rather than use catenation and symbolic character names to
+ introduce special characters into strings, one may instead use a
+ special bracket notation, which is also used to print strings. A
+ sequence of characters of the form `["XX"]' within a string or
+ character literal denotes the (single) character whose numeric
+ encoding is XX in hexadecimal. The sequence of characters `["""]'
+ also denotes a single quotation mark in strings. For example,
+ "One line.["0a"]Next line.["0a"]"
+ contains an ASCII newline character (`Ada.Characters.Latin_1.LF')
+ after each period.
+
+ * The subtype used as a prefix for the attributes 'Pos, 'Min, and
+ 'Max is optional (and is ignored in any case). For example, it is
+ valid to write
+
+ (gdb) print 'max(x, y)
+
+ * When printing arrays, GDB uses positional notation when the array
+ has a lower bound of 1, and uses a modified named notation
+ otherwise. For example, a one-dimensional array of three integers
+ with a lower bound of 3 might print as
+
+ (3 => 10, 17, 1)
+
+ That is, in contrast to valid Ada, only the first component has a
+ `=>' clause.
+
+ * You may abbreviate attributes in expressions with any unique,
+ multi-character subsequence of their names (an exact match gets
+ preference). For example, you may use a'len, a'gth, or a'lh in
+ place of a'length.
+
+ * Since Ada is case-insensitive, the debugger normally maps
+ identifiers you type to lower case. The GNAT compiler uses
+ upper-case characters for some of its internal identifiers, which
+ are normally of no interest to users. For the rare occasions when
+ you actually have to look at them, enclose them in angle brackets
+ to avoid the lower-case mapping. For example,
+ (gdb) print <JMPBUF_SAVE>[0]
+
+ * Printing an object of class-wide type or dereferencing an
+ access-to-class-wide value will display all the components of the
+ object's specific type (as indicated by its run-time tag).
+ Likewise, component selection on such a value will operate on the
+ specific type of the object.
+
+
+
+File: gdb.info, Node: Stopping Before Main Program, Next: Ada Tasks, Prev: Additions to Ada, Up: Ada
+
+15.4.8.4 Stopping at the Very Beginning
+.......................................
+
+It is sometimes necessary to debug the program during elaboration, and
+before reaching the main procedure. As defined in the Ada Reference
+Manual, the elaboration code is invoked from a procedure called
+`adainit'. To run your program up to the beginning of elaboration,
+simply use the following two commands: `tbreak adainit' and `run'.
+
+
+File: gdb.info, Node: Ada Tasks, Next: Ada Tasks and Core Files, Prev: Stopping Before Main Program, Up: Ada
+
+15.4.8.5 Extensions for Ada Tasks
+.................................
+
+Support for Ada tasks is analogous to that for threads (*note
+Threads::). GDB provides the following task-related commands:
+
+`info tasks'
+ This command shows a list of current Ada tasks, as in the
+ following example:
+
+ (gdb) info tasks
+ ID TID P-ID Pri State Name
+ 1 8088000 0 15 Child Activation Wait main_task
+ 2 80a4000 1 15 Accept Statement b
+ 3 809a800 1 15 Child Activation Wait a
+ * 4 80ae800 3 15 Runnable c
+
+ In this listing, the asterisk before the last task indicates it to
+ be the task currently being inspected.
+
+ ID
+ Represents GDB's internal task number.
+
+ TID
+ The Ada task ID.
+
+ P-ID
+ The parent's task ID (GDB's internal task number).
+
+ Pri
+ The base priority of the task.
+
+ State
+ Current state of the task.
+
+ `Unactivated'
+ The task has been created but has not been activated.
+ It cannot be executing.
+
+ `Runnable'
+ The task is not blocked for any reason known to Ada.
+ (It may be waiting for a mutex, though.) It is
+ conceptually "executing" in normal mode.
+
+ `Terminated'
+ The task is terminated, in the sense of ARM 9.3 (5).
+ Any dependents that were waiting on terminate
+ alternatives have been awakened and have terminated
+ themselves.
+
+ `Child Activation Wait'
+ The task is waiting for created tasks to complete
+ activation.
+
+ `Accept Statement'
+ The task is waiting on an accept or selective wait
+ statement.
+
+ `Waiting on entry call'
+ The task is waiting on an entry call.
+
+ `Async Select Wait'
+ The task is waiting to start the abortable part of an
+ asynchronous select statement.
+
+ `Delay Sleep'
+ The task is waiting on a select statement with only a
+ delay alternative open.
+
+ `Child Termination Wait'
+ The task is sleeping having completed a master within
+ itself, and is waiting for the tasks dependent on that
+ master to become terminated or waiting on a terminate
+ Phase.
+
+ `Wait Child in Term Alt'
+ The task is sleeping waiting for tasks on terminate
+ alternatives to finish terminating.
+
+ `Accepting RV with TASKNO'
+ The task is accepting a rendez-vous with the task TASKNO.
+
+ Name
+ Name of the task in the program.
+
+
+`info task TASKNO'
+ This command shows detailled informations on the specified task,
+ as in the following example:
+ (gdb) info tasks
+ ID TID P-ID Pri State Name
+ 1 8077880 0 15 Child Activation Wait main_task
+ * 2 807c468 1 15 Runnable task_1
+ (gdb) info task 2
+ Ada Task: 0x807c468
+ Name: task_1
+ Thread: 0x807f378
+ Parent: 1 (main_task)
+ Base Priority: 15
+ State: Runnable
+
+`task'
+ This command prints the ID of the current task.
+
+ (gdb) info tasks
+ ID TID P-ID Pri State Name
+ 1 8077870 0 15 Child Activation Wait main_task
+ * 2 807c458 1 15 Runnable t
+ (gdb) task
+ [Current task is 2]
+
+`task TASKNO'
+ This command is like the `thread THREADNO' command (*note
+ Threads::). It switches the context of debugging from the current
+ task to the given task.
+
+ (gdb) info tasks
+ ID TID P-ID Pri State Name
+ 1 8077870 0 15 Child Activation Wait main_task
+ * 2 807c458 1 15 Runnable t
+ (gdb) task 1
+ [Switching to task 1]
+ #0 0x8067726 in pthread_cond_wait ()
+ (gdb) bt
+ #0 0x8067726 in pthread_cond_wait ()
+ #1 0x8056714 in system.os_interface.pthread_cond_wait ()
+ #2 0x805cb63 in system.task_primitives.operations.sleep ()
+ #3 0x806153e in system.tasking.stages.activate_tasks ()
+ #4 0x804aacc in un () at un.adb:5
+
+`break LINESPEC task TASKNO'
+`break LINESPEC task TASKNO if ...'
+ These commands are like the `break ... thread ...' command (*note
+ Thread Stops::). LINESPEC specifies source lines, as described in
+ *Note Specify Location::.
+
+ Use the qualifier `task TASKNO' with a breakpoint command to
+ specify that you only want GDB to stop the program when a
+ particular Ada task reaches this breakpoint. TASKNO is one of the
+ numeric task identifiers assigned by GDB, shown in the first
+ column of the `info tasks' display.
+
+ If you do not specify `task TASKNO' when you set a breakpoint, the
+ breakpoint applies to _all_ tasks of your program.
+
+ You can use the `task' qualifier on conditional breakpoints as
+ well; in this case, place `task TASKNO' before the breakpoint
+ condition (before the `if').
+
+ For example,
+
+ (gdb) info tasks
+ ID TID P-ID Pri State Name
+ 1 140022020 0 15 Child Activation Wait main_task
+ 2 140045060 1 15 Accept/Select Wait t2
+ 3 140044840 1 15 Runnable t1
+ * 4 140056040 1 15 Runnable t3
+ (gdb) b 15 task 2
+ Breakpoint 5 at 0x120044cb0: file test_task_debug.adb, line 15.
+ (gdb) cont
+ Continuing.
+ task # 1 running
+ task # 2 running
+
+ Breakpoint 5, test_task_debug () at test_task_debug.adb:15
+ 15 flush;
+ (gdb) info tasks
+ ID TID P-ID Pri State Name
+ 1 140022020 0 15 Child Activation Wait main_task
+ * 2 140045060 1 15 Runnable t2
+ 3 140044840 1 15 Runnable t1
+ 4 140056040 1 15 Delay Sleep t3
+
+
+File: gdb.info, Node: Ada Tasks and Core Files, Next: Ravenscar Profile, Prev: Ada Tasks, Up: Ada
+
+15.4.8.6 Tasking Support when Debugging Core Files
+..................................................
+
+When inspecting a core file, as opposed to debugging a live program,
+tasking support may be limited or even unavailable, depending on the
+platform being used. For instance, on x86-linux, the list of tasks is
+available, but task switching is not supported. On Tru64, however,
+task switching will work as usual.
+
+ On certain platforms, including Tru64, the debugger needs to perform
+some memory writes in order to provide Ada tasking support. When
+inspecting a core file, this means that the core file must be opened
+with read-write privileges, using the command `"set write on"' (*note
+Patching::). Under these circumstances, you should make a backup copy
+of the core file before inspecting it with GDB.
+
+
+File: gdb.info, Node: Ravenscar Profile, Next: Ada Glitches, Prev: Ada Tasks and Core Files, Up: Ada
+
+15.4.8.7 Tasking Support when using the Ravenscar Profile
+.........................................................
+
+The "Ravenscar Profile" is a subset of the Ada tasking features,
+specifically designed for systems with safety-critical real-time
+requirements.
+
+`set ravenscar task-switching on'
+ Allows task switching when debugging a program that uses the
+ Ravenscar Profile. This is the default.
+
+`set ravenscar task-switching off'
+ Turn off task switching when debugging a program that uses the
+ Ravenscar Profile. This is mostly intended to disable the code
+ that adds support for the Ravenscar Profile, in case a bug in
+ either GDB or in the Ravenscar runtime is preventing GDB from
+ working properly. To be effective, this command should be run
+ before the program is started.
+
+`show ravenscar task-switching'
+ Show whether it is possible to switch from task to task in a
+ program using the Ravenscar Profile.
+
+
+
+File: gdb.info, Node: Ada Glitches, Prev: Ravenscar Profile, Up: Ada
+
+15.4.8.8 Known Peculiarities of Ada Mode
+........................................
+
+Besides the omissions listed previously (*note Omissions from Ada::),
+we know of several problems with and limitations of Ada mode in GDB,
+some of which will be fixed with planned future releases of the debugger
+and the GNU Ada compiler.
+
+ * Static constants that the compiler chooses not to materialize as
+ objects in storage are invisible to the debugger.
+
+ * Named parameter associations in function argument lists are
+ ignored (the argument lists are treated as positional).
+
+ * Many useful library packages are currently invisible to the
+ debugger.
+
+ * Fixed-point arithmetic, conversions, input, and output is carried
+ out using floating-point arithmetic, and may give results that
+ only approximate those on the host machine.
+
+ * The GNAT compiler never generates the prefix `Standard' for any of
+ the standard symbols defined by the Ada language. GDB knows about
+ this: it will strip the prefix from names when you use it, and
+ will never look for a name you have so qualified among local
+ symbols, nor match against symbols in other packages or
+ subprograms. If you have defined entities anywhere in your
+ program other than parameters and local variables whose simple
+ names match names in `Standard', GNAT's lack of qualification here
+ can cause confusion. When this happens, you can usually resolve
+ the confusion by qualifying the problematic names with package
+ `Standard' explicitly.
+
+ Older versions of the compiler sometimes generate erroneous debugging
+information, resulting in the debugger incorrectly printing the value
+of affected entities. In some cases, the debugger is able to work
+around an issue automatically. In other cases, the debugger is able to
+work around the issue, but the work-around has to be specifically
+enabled.
+
+`set ada trust-PAD-over-XVS on'
+ Configure GDB to strictly follow the GNAT encoding when computing
+ the value of Ada entities, particularly when `PAD' and `PAD___XVS'
+ types are involved (see `ada/exp_dbug.ads' in the GCC sources for
+ a complete description of the encoding used by the GNAT compiler).
+ This is the default.
+
+`set ada trust-PAD-over-XVS off'
+ This is related to the encoding using by the GNAT compiler. If
+ GDB sometimes prints the wrong value for certain entities,
+ changing `ada trust-PAD-over-XVS' to `off' activates a work-around
+ which may fix the issue. It is always safe to set `ada
+ trust-PAD-over-XVS' to `off', but this incurs a slight performance
+ penalty, so it is recommended to leave this setting to `on' unless
+ necessary.
+
+
+
+File: gdb.info, Node: Unsupported Languages, Prev: Supported Languages, Up: Languages
+
+15.5 Unsupported Languages
+==========================
+
+In addition to the other fully-supported programming languages, GDB
+also provides a pseudo-language, called `minimal'. It does not
+represent a real programming language, but provides a set of
+capabilities close to what the C or assembly languages provide. This
+should allow most simple operations to be performed while debugging an
+application that uses a language currently not supported by GDB.
+
+ If the language is set to `auto', GDB will automatically select this
+language if the current frame corresponds to an unsupported language.
+
+
+File: gdb.info, Node: Symbols, Next: Altering, Prev: Languages, Up: Top
+
+16 Examining the Symbol Table
+*****************************
+
+The commands described in this chapter allow you to inquire about the
+symbols (names of variables, functions and types) defined in your
+program. This information is inherent in the text of your program and
+does not change as your program executes. GDB finds it in your
+program's symbol table, in the file indicated when you started GDB
+(*note Choosing Files: File Options.), or by one of the file-management
+commands (*note Commands to Specify Files: Files.).
+
+ Occasionally, you may need to refer to symbols that contain unusual
+characters, which GDB ordinarily treats as word delimiters. The most
+frequent case is in referring to static variables in other source files
+(*note Program Variables: Variables.). File names are recorded in
+object files as debugging symbols, but GDB would ordinarily parse a
+typical file name, like `foo.c', as the three words `foo' `.' `c'. To
+allow GDB to recognize `foo.c' as a single symbol, enclose it in single
+quotes; for example,
+
+ p 'foo.c'::x
+
+looks up the value of `x' in the scope of the file `foo.c'.
+
+`set case-sensitive on'
+`set case-sensitive off'
+`set case-sensitive auto'
+ Normally, when GDB looks up symbols, it matches their names with
+ case sensitivity determined by the current source language.
+ Occasionally, you may wish to control that. The command `set
+ case-sensitive' lets you do that by specifying `on' for
+ case-sensitive matches or `off' for case-insensitive ones. If you
+ specify `auto', case sensitivity is reset to the default suitable
+ for the source language. The default is case-sensitive matches
+ for all languages except for Fortran, for which the default is
+ case-insensitive matches.
+
+`show case-sensitive'
+ This command shows the current setting of case sensitivity for
+ symbols lookups.
+
+`info address SYMBOL'
+ Describe where the data for SYMBOL is stored. For a register
+ variable, this says which register it is kept in. For a
+ non-register local variable, this prints the stack-frame offset at
+ which the variable is always stored.
+
+ Note the contrast with `print &SYMBOL', which does not work at all
+ for a register variable, and for a stack local variable prints the
+ exact address of the current instantiation of the variable.
+
+`info symbol ADDR'
+ Print the name of a symbol which is stored at the address ADDR.
+ If no symbol is stored exactly at ADDR, GDB prints the nearest
+ symbol and an offset from it:
+
+ (gdb) info symbol 0x54320
+ _initialize_vx + 396 in section .text
+
+ This is the opposite of the `info address' command. You can use
+ it to find out the name of a variable or a function given its
+ address.
+
+ For dynamically linked executables, the name of executable or
+ shared library containing the symbol is also printed:
+
+ (gdb) info symbol 0x400225
+ _start + 5 in section .text of /tmp/a.out
+ (gdb) info symbol 0x2aaaac2811cf
+ __read_nocancel + 6 in section .text of /usr/lib64/libc.so.6
+
+`whatis [ARG]'
+ Print the data type of ARG, which can be either an expression or a
+ name of a data type. With no argument, print the data type of
+ `$', the last value in the value history.
+
+ If ARG is an expression (*note Expressions: Expressions.), it is
+ not actually evaluated, and any side-effecting operations (such as
+ assignments or function calls) inside it do not take place.
+
+ If ARG is a variable or an expression, `whatis' prints its literal
+ type as it is used in the source code. If the type was defined
+ using a `typedef', `whatis' will _not_ print the data type
+ underlying the `typedef'. If the type of the variable or the
+ expression is a compound data type, such as `struct' or `class',
+ `whatis' never prints their fields or methods. It just prints the
+ `struct'/`class' name (a.k.a. its "tag"). If you want to see the
+ members of such a compound data type, use `ptype'.
+
+ If ARG is a type name that was defined using `typedef', `whatis'
+ "unrolls" only one level of that `typedef'. Unrolling means that
+ `whatis' will show the underlying type used in the `typedef'
+ declaration of ARG. However, if that underlying type is also a
+ `typedef', `whatis' will not unroll it.
+
+ For C code, the type names may also have the form `class
+ CLASS-NAME', `struct STRUCT-TAG', `union UNION-TAG' or `enum
+ ENUM-TAG'.
+
+`ptype [ARG]'
+ `ptype' accepts the same arguments as `whatis', but prints a
+ detailed description of the type, instead of just the name of the
+ type. *Note Expressions: Expressions.
+
+ Contrary to `whatis', `ptype' always unrolls any `typedef's in its
+ argument declaration, whether the argument is a variable,
+ expression, or a data type. This means that `ptype' of a variable
+ or an expression will not print literally its type as present in
+ the source code--use `whatis' for that. `typedef's at the pointer
+ or reference targets are also unrolled. Only `typedef's of
+ fields, methods and inner `class typedef's of `struct's, `class'es
+ and `union's are not unrolled even with `ptype'.
+
+ For example, for this variable declaration:
+
+ typedef double real_t;
+ struct complex { real_t real; double imag; };
+ typedef struct complex complex_t;
+ complex_t var;
+ real_t *real_pointer_var;
+
+ the two commands give this output:
+
+ (gdb) whatis var
+ type = complex_t
+ (gdb) ptype var
+ type = struct complex {
+ real_t real;
+ double imag;
+ }
+ (gdb) whatis complex_t
+ type = struct complex
+ (gdb) whatis struct complex
+ type = struct complex
+ (gdb) ptype struct complex
+ type = struct complex {
+ real_t real;
+ double imag;
+ }
+ (gdb) whatis real_pointer_var
+ type = real_t *
+ (gdb) ptype real_pointer_var
+ type = double *
+
+ As with `whatis', using `ptype' without an argument refers to the
+ type of `$', the last value in the value history.
+
+ Sometimes, programs use opaque data types or incomplete
+ specifications of complex data structure. If the debug
+ information included in the program does not allow GDB to display
+ a full declaration of the data type, it will say `<incomplete
+ type>'. For example, given these declarations:
+
+ struct foo;
+ struct foo *fooptr;
+
+ but no definition for `struct foo' itself, GDB will say:
+
+ (gdb) ptype foo
+ $1 = <incomplete type>
+
+ "Incomplete type" is C terminology for data types that are not
+ completely specified.
+
+`info types REGEXP'
+`info types'
+ Print a brief description of all types whose names match the
+ regular expression REGEXP (or all types in your program, if you
+ supply no argument). Each complete typename is matched as though
+ it were a complete line; thus, `i type value' gives information on
+ all types in your program whose names include the string `value',
+ but `i type ^value$' gives information only on types whose complete
+ name is `value'.
+
+ This command differs from `ptype' in two ways: first, like
+ `whatis', it does not print a detailed description; second, it
+ lists all source files where a type is defined.
+
+`info scope LOCATION'
+ List all the variables local to a particular scope. This command
+ accepts a LOCATION argument--a function name, a source line, or an
+ address preceded by a `*', and prints all the variables local to
+ the scope defined by that location. (*Note Specify Location::, for
+ details about supported forms of LOCATION.) For example:
+
+ (gdb) info scope command_line_handler
+ Scope for command_line_handler:
+ Symbol rl is an argument at stack/frame offset 8, length 4.
+ Symbol linebuffer is in static storage at address 0x150a18, length 4.
+ Symbol linelength is in static storage at address 0x150a1c, length 4.
+ Symbol p is a local variable in register $esi, length 4.
+ Symbol p1 is a local variable in register $ebx, length 4.
+ Symbol nline is a local variable in register $edx, length 4.
+ Symbol repeat is a local variable at frame offset -8, length 4.
+
+ This command is especially useful for determining what data to
+ collect during a "trace experiment", see *Note collect: Tracepoint
+ Actions.
+
+`info source'
+ Show information about the current source file--that is, the
+ source file for the function containing the current point of
+ execution:
+ * the name of the source file, and the directory containing it,
+
+ * the directory it was compiled in,
+
+ * its length, in lines,
+
+ * which programming language it is written in,
+
+ * whether the executable includes debugging information for
+ that file, and if so, what format the information is in
+ (e.g., STABS, Dwarf 2, etc.), and
+
+ * whether the debugging information includes information about
+ preprocessor macros.
+
+`info sources'
+ Print the names of all source files in your program for which
+ there is debugging information, organized into two lists: files
+ whose symbols have already been read, and files whose symbols will
+ be read when needed.
+
+`info functions'
+ Print the names and data types of all defined functions.
+
+`info functions REGEXP'
+ Print the names and data types of all defined functions whose
+ names contain a match for regular expression REGEXP. Thus, `info
+ fun step' finds all functions whose names include `step'; `info
+ fun ^step' finds those whose names start with `step'. If a
+ function name contains characters that conflict with the regular
+ expression language (e.g. `operator*()'), they may be quoted with
+ a backslash.
+
+`info variables'
+ Print the names and data types of all variables that are defined
+ outside of functions (i.e. excluding local variables).
+
+`info variables REGEXP'
+ Print the names and data types of all variables (except for local
+ variables) whose names contain a match for regular expression
+ REGEXP.
+
+`info classes'
+`info classes REGEXP'
+ Display all Objective-C classes in your program, or (with the
+ REGEXP argument) all those matching a particular regular
+ expression.
+
+`info selectors'
+`info selectors REGEXP'
+ Display all Objective-C selectors in your program, or (with the
+ REGEXP argument) all those matching a particular regular
+ expression.
+
+ Some systems allow individual object files that make up your
+ program to be replaced without stopping and restarting your
+ program. For example, in VxWorks you can simply recompile a
+ defective object file and keep on running. If you are running on
+ one of these systems, you can allow GDB to reload the symbols for
+ automatically relinked modules:
+
+ `set symbol-reloading on'
+ Replace symbol definitions for the corresponding source file
+ when an object file with a particular name is seen again.
+
+ `set symbol-reloading off'
+ Do not replace symbol definitions when encountering object
+ files of the same name more than once. This is the default
+ state; if you are not running on a system that permits
+ automatic relinking of modules, you should leave
+ `symbol-reloading' off, since otherwise GDB may discard
+ symbols when linking large programs, that may contain several
+ modules (from different directories or libraries) with the
+ same name.
+
+ `show symbol-reloading'
+ Show the current `on' or `off' setting.
+
+`set opaque-type-resolution on'
+ Tell GDB to resolve opaque types. An opaque type is a type
+ declared as a pointer to a `struct', `class', or `union'--for
+ example, `struct MyType *'--that is used in one source file
+ although the full declaration of `struct MyType' is in another
+ source file. The default is on.
+
+ A change in the setting of this subcommand will not take effect
+ until the next time symbols for a file are loaded.
+
+`set opaque-type-resolution off'
+ Tell GDB not to resolve opaque types. In this case, the type is
+ printed as follows:
+ {<no data fields>}
+
+`show opaque-type-resolution'
+ Show whether opaque types are resolved or not.
+
+`maint print symbols FILENAME'
+`maint print psymbols FILENAME'
+`maint print msymbols FILENAME'
+ Write a dump of debugging symbol data into the file FILENAME.
+ These commands are used to debug the GDB symbol-reading code. Only
+ symbols with debugging data are included. If you use `maint print
+ symbols', GDB includes all the symbols for which it has already
+ collected full details: that is, FILENAME reflects symbols for
+ only those files whose symbols GDB has read. You can use the
+ command `info sources' to find out which files these are. If you
+ use `maint print psymbols' instead, the dump shows information
+ about symbols that GDB only knows partially--that is, symbols
+ defined in files that GDB has skimmed, but not yet read
+ completely. Finally, `maint print msymbols' dumps just the
+ minimal symbol information required for each object file from
+ which GDB has read some symbols. *Note Commands to Specify Files:
+ Files, for a discussion of how GDB reads symbols (in the
+ description of `symbol-file').
+
+`maint info symtabs [ REGEXP ]'
+`maint info psymtabs [ REGEXP ]'
+ List the `struct symtab' or `struct partial_symtab' structures
+ whose names match REGEXP. If REGEXP is not given, list them all.
+ The output includes expressions which you can copy into a GDB
+ debugging this one to examine a particular structure in more
+ detail. For example:
+
+ (gdb) maint info psymtabs dwarf2read
+ { objfile /home/gnu/build/gdb/gdb
+ ((struct objfile *) 0x82e69d0)
+ { psymtab /home/gnu/src/gdb/dwarf2read.c
+ ((struct partial_symtab *) 0x8474b10)
+ readin no
+ fullname (null)
+ text addresses 0x814d3c8 -- 0x8158074
+ globals (* (struct partial_symbol **) 0x8507a08 @ 9)
+ statics (* (struct partial_symbol **) 0x40e95b78 @ 2882)
+ dependencies (none)
+ }
+ }
+ (gdb) maint info symtabs
+ (gdb)
+ We see that there is one partial symbol table whose filename
+ contains the string `dwarf2read', belonging to the `gdb'
+ executable; and we see that GDB has not read in any symtabs yet at
+ all. If we set a breakpoint on a function, that will cause GDB to
+ read the symtab for the compilation unit containing that function:
+
+ (gdb) break dwarf2_psymtab_to_symtab
+ Breakpoint 1 at 0x814e5da: file /home/gnu/src/gdb/dwarf2read.c,
+ line 1574.
+ (gdb) maint info symtabs
+ { objfile /home/gnu/build/gdb/gdb
+ ((struct objfile *) 0x82e69d0)
+ { symtab /home/gnu/src/gdb/dwarf2read.c
+ ((struct symtab *) 0x86c1f38)
+ dirname (null)
+ fullname (null)
+ blockvector ((struct blockvector *) 0x86c1bd0) (primary)
+ linetable ((struct linetable *) 0x8370fa0)
+ debugformat DWARF 2
+ }
+ }
+ (gdb)
+
+
+File: gdb.info, Node: Altering, Next: GDB Files, Prev: Symbols, Up: Top
+
+17 Altering Execution
+*********************
+
+Once you think you have found an error in your program, you might want
+to find out for certain whether correcting the apparent error would
+lead to correct results in the rest of the run. You can find the
+answer by experiment, using the GDB features for altering execution of
+the program.
+
+ For example, you can store new values into variables or memory
+locations, give your program a signal, restart it at a different
+address, or even return prematurely from a function.
+
+* Menu:
+
+* Assignment:: Assignment to variables
+* Jumping:: Continuing at a different address
+* Signaling:: Giving your program a signal
+* Returning:: Returning from a function
+* Calling:: Calling your program's functions
+* Patching:: Patching your program
+
+
+File: gdb.info, Node: Assignment, Next: Jumping, Up: Altering
+
+17.1 Assignment to Variables
+============================
+
+To alter the value of a variable, evaluate an assignment expression.
+*Note Expressions: Expressions. For example,
+
+ print x=4
+
+stores the value 4 into the variable `x', and then prints the value of
+the assignment expression (which is 4). *Note Using GDB with Different
+Languages: Languages, for more information on operators in supported
+languages.
+
+ If you are not interested in seeing the value of the assignment, use
+the `set' command instead of the `print' command. `set' is really the
+same as `print' except that the expression's value is not printed and
+is not put in the value history (*note Value History: Value History.).
+The expression is evaluated only for its effects.
+
+ If the beginning of the argument string of the `set' command appears
+identical to a `set' subcommand, use the `set variable' command instead
+of just `set'. This command is identical to `set' except for its lack
+of subcommands. For example, if your program has a variable `width',
+you get an error if you try to set a new value with just `set
+width=13', because GDB has the command `set width':
+
+ (gdb) whatis width
+ type = double
+ (gdb) p width
+ $4 = 13
+ (gdb) set width=47
+ Invalid syntax in expression.
+
+The invalid expression, of course, is `=47'. In order to actually set
+the program's variable `width', use
+
+ (gdb) set var width=47
+
+ Because the `set' command has many subcommands that can conflict
+with the names of program variables, it is a good idea to use the `set
+variable' command instead of just `set'. For example, if your program
+has a variable `g', you run into problems if you try to set a new value
+with just `set g=4', because GDB has the command `set gnutarget',
+abbreviated `set g':
+
+ (gdb) whatis g
+ type = double
+ (gdb) p g
+ $1 = 1
+ (gdb) set g=4
+ (gdb) p g
+ $2 = 1
+ (gdb) r
+ The program being debugged has been started already.
+ Start it from the beginning? (y or n) y
+ Starting program: /home/smith/cc_progs/a.out
+ "/home/smith/cc_progs/a.out": can't open to read symbols:
+ Invalid bfd target.
+ (gdb) show g
+ The current BFD target is "=4".
+
+The program variable `g' did not change, and you silently set the
+`gnutarget' to an invalid value. In order to set the variable `g', use
+
+ (gdb) set var g=4
+
+ GDB allows more implicit conversions in assignments than C; you can
+freely store an integer value into a pointer variable or vice versa,
+and you can convert any structure to any other structure that is the
+same length or shorter.
+
+ To store values into arbitrary places in memory, use the `{...}'
+construct to generate a value of specified type at a specified address
+(*note Expressions: Expressions.). For example, `{int}0x83040' refers
+to memory location `0x83040' as an integer (which implies a certain size
+and representation in memory), and
+
+ set {int}0x83040 = 4
+
+stores the value 4 into that memory location.
+
+
+File: gdb.info, Node: Jumping, Next: Signaling, Prev: Assignment, Up: Altering
+
+17.2 Continuing at a Different Address
+======================================
+
+Ordinarily, when you continue your program, you do so at the place where
+it stopped, with the `continue' command. You can instead continue at
+an address of your own choosing, with the following commands:
+
+`jump LINESPEC'
+`jump LOCATION'
+ Resume execution at line LINESPEC or at address given by LOCATION.
+ Execution stops again immediately if there is a breakpoint there.
+ *Note Specify Location::, for a description of the different
+ forms of LINESPEC and LOCATION. It is common practice to use the
+ `tbreak' command in conjunction with `jump'. *Note Setting
+ Breakpoints: Set Breaks.
+
+ The `jump' command does not change the current stack frame, or the
+ stack pointer, or the contents of any memory location or any
+ register other than the program counter. If line LINESPEC is in a
+ different function from the one currently executing, the results
+ may be bizarre if the two functions expect different patterns of
+ arguments or of local variables. For this reason, the `jump'
+ command requests confirmation if the specified line is not in the
+ function currently executing. However, even bizarre results are
+ predictable if you are well acquainted with the machine-language
+ code of your program.
+
+ On many systems, you can get much the same effect as the `jump'
+command by storing a new value into the register `$pc'. The difference
+is that this does not start your program running; it only changes the
+address of where it _will_ run when you continue. For example,
+
+ set $pc = 0x485
+
+makes the next `continue' command or stepping command execute at
+address `0x485', rather than at the address where your program stopped.
+*Note Continuing and Stepping: Continuing and Stepping.
+
+ The most common occasion to use the `jump' command is to back
+up--perhaps with more breakpoints set--over a portion of a program that
+has already executed, in order to examine its execution in more detail.
+
+
+File: gdb.info, Node: Signaling, Next: Returning, Prev: Jumping, Up: Altering
+
+17.3 Giving your Program a Signal
+=================================
+
+`signal SIGNAL'
+ Resume execution where your program stopped, but immediately give
+ it the signal SIGNAL. SIGNAL can be the name or the number of a
+ signal. For example, on many systems `signal 2' and `signal
+ SIGINT' are both ways of sending an interrupt signal.
+
+ Alternatively, if SIGNAL is zero, continue execution without
+ giving a signal. This is useful when your program stopped on
+ account of a signal and would ordinary see the signal when resumed
+ with the `continue' command; `signal 0' causes it to resume
+ without a signal.
+
+ `signal' does not repeat when you press <RET> a second time after
+ executing the command.
+
+ Invoking the `signal' command is not the same as invoking the `kill'
+utility from the shell. Sending a signal with `kill' causes GDB to
+decide what to do with the signal depending on the signal handling
+tables (*note Signals::). The `signal' command passes the signal
+directly to your program.
+
+
+File: gdb.info, Node: Returning, Next: Calling, Prev: Signaling, Up: Altering
+
+17.4 Returning from a Function
+==============================
+
+`return'
+`return EXPRESSION'
+ You can cancel execution of a function call with the `return'
+ command. If you give an EXPRESSION argument, its value is used as
+ the function's return value.
+
+ When you use `return', GDB discards the selected stack frame (and
+all frames within it). You can think of this as making the discarded
+frame return prematurely. If you wish to specify a value to be
+returned, give that value as the argument to `return'.
+
+ This pops the selected stack frame (*note Selecting a Frame:
+Selection.), and any other frames inside of it, leaving its caller as
+the innermost remaining frame. That frame becomes selected. The
+specified value is stored in the registers used for returning values of
+functions.
+
+ The `return' command does not resume execution; it leaves the
+program stopped in the state that would exist if the function had just
+returned. In contrast, the `finish' command (*note Continuing and
+Stepping: Continuing and Stepping.) resumes execution until the
+selected stack frame returns naturally.
+
+ GDB needs to know how the EXPRESSION argument should be set for the
+inferior. The concrete registers assignment depends on the OS ABI and
+the type being returned by the selected stack frame. For example it is
+common for OS ABI to return floating point values in FPU registers
+while integer values in CPU registers. Still some ABIs return even
+floating point values in CPU registers. Larger integer widths (such as
+`long long int') also have specific placement rules. GDB already knows
+the OS ABI from its current target so it needs to find out also the
+type being returned to make the assignment into the right register(s).
+
+ Normally, the selected stack frame has debug info. GDB will always
+use the debug info instead of the implicit type of EXPRESSION when the
+debug info is available. For example, if you type `return -1', and the
+function in the current stack frame is declared to return a `long long
+int', GDB transparently converts the implicit `int' value of -1 into a
+`long long int':
+
+ Breakpoint 1, func () at gdb.base/return-nodebug.c:29
+ 29 return 31;
+ (gdb) return -1
+ Make func return now? (y or n) y
+ #0 0x004004f6 in main () at gdb.base/return-nodebug.c:43
+ 43 printf ("result=%lld\n", func ());
+ (gdb)
+
+ However, if the selected stack frame does not have a debug info,
+e.g., if the function was compiled without debug info, GDB has to find
+out the type to return from user. Specifying a different type by
+mistake may set the value in different inferior registers than the
+caller code expects. For example, typing `return -1' with its implicit
+type `int' would set only a part of a `long long int' result for a
+debug info less function (on 32-bit architectures). Therefore the user
+is required to specify the return type by an appropriate cast
+explicitly:
+
+ Breakpoint 2, 0x0040050b in func ()
+ (gdb) return -1
+ Return value type not available for selected stack frame.
+ Please use an explicit cast of the value to return.
+ (gdb) return (long long int) -1
+ Make selected stack frame return now? (y or n) y
+ #0 0x00400526 in main ()
+ (gdb)
+
+
+File: gdb.info, Node: Calling, Next: Patching, Prev: Returning, Up: Altering
+
+17.5 Calling Program Functions
+==============================
+
+`print EXPR'
+ Evaluate the expression EXPR and display the resulting value.
+ EXPR may include calls to functions in the program being debugged.
+
+`call EXPR'
+ Evaluate the expression EXPR without displaying `void' returned
+ values.
+
+ You can use this variant of the `print' command if you want to
+ execute a function from your program that does not return anything
+ (a.k.a. "a void function"), but without cluttering the output with
+ `void' returned values that GDB will otherwise print. If the
+ result is not void, it is printed and saved in the value history.
+
+ It is possible for the function you call via the `print' or `call'
+command to generate a signal (e.g., if there's a bug in the function,
+or if you passed it incorrect arguments). What happens in that case is
+controlled by the `set unwindonsignal' command.
+
+ Similarly, with a C++ program it is possible for the function you
+call via the `print' or `call' command to generate an exception that is
+not handled due to the constraints of the dummy frame. In this case,
+any exception that is raised in the frame, but has an out-of-frame
+exception handler will not be found. GDB builds a dummy-frame for the
+inferior function call, and the unwinder cannot seek for exception
+handlers outside of this dummy-frame. What happens in that case is
+controlled by the `set unwind-on-terminating-exception' command.
+
+`set unwindonsignal'
+ Set unwinding of the stack if a signal is received while in a
+ function that GDB called in the program being debugged. If set to
+ on, GDB unwinds the stack it created for the call and restores the
+ context to what it was before the call. If set to off (the
+ default), GDB stops in the frame where the signal was received.
+
+`show unwindonsignal'
+ Show the current setting of stack unwinding in the functions
+ called by GDB.
+
+`set unwind-on-terminating-exception'
+ Set unwinding of the stack if a C++ exception is raised, but left
+ unhandled while in a function that GDB called in the program being
+ debugged. If set to on (the default), GDB unwinds the stack it
+ created for the call and restores the context to what it was before
+ the call. If set to off, GDB the exception is delivered to the
+ default C++ exception handler and the inferior terminated.
+
+`show unwind-on-terminating-exception'
+ Show the current setting of stack unwinding in the functions
+ called by GDB.
+
+
+ Sometimes, a function you wish to call is actually a "weak alias"
+for another function. In such case, GDB might not pick up the type
+information, including the types of the function arguments, which
+causes GDB to call the inferior function incorrectly. As a result, the
+called function will function erroneously and may even crash. A
+solution to that is to use the name of the aliased function instead.
+
+
+File: gdb.info, Node: Patching, Prev: Calling, Up: Altering
+
+17.6 Patching Programs
+======================
+
+By default, GDB opens the file containing your program's executable
+code (or the corefile) read-only. This prevents accidental alterations
+to machine code; but it also prevents you from intentionally patching
+your program's binary.
+
+ If you'd like to be able to patch the binary, you can specify that
+explicitly with the `set write' command. For example, you might want
+to turn on internal debugging flags, or even to make emergency repairs.
+
+`set write on'
+`set write off'
+ If you specify `set write on', GDB opens executable and core files
+ for both reading and writing; if you specify `set write off' (the
+ default), GDB opens them read-only.
+
+ If you have already loaded a file, you must load it again (using
+ the `exec-file' or `core-file' command) after changing `set
+ write', for your new setting to take effect.
+
+`show write'
+ Display whether executable files and core files are opened for
+ writing as well as reading.
+
+
+File: gdb.info, Node: GDB Files, Next: Targets, Prev: Altering, Up: Top
+
+18 GDB Files
+************
+
+GDB needs to know the file name of the program to be debugged, both in
+order to read its symbol table and in order to start your program. To
+debug a core dump of a previous run, you must also tell GDB the name of
+the core dump file.
+
+* Menu:
+
+* Files:: Commands to specify files
+* Separate Debug Files:: Debugging information in separate files
+* Index Files:: Index files speed up GDB
+* Symbol Errors:: Errors reading symbol files
+* Data Files:: GDB data files
+
+
+File: gdb.info, Node: Files, Next: Separate Debug Files, Up: GDB Files
+
+18.1 Commands to Specify Files
+==============================
+
+You may want to specify executable and core dump file names. The usual
+way to do this is at start-up time, using the arguments to GDB's
+start-up commands (*note Getting In and Out of GDB: Invocation.).
+
+ Occasionally it is necessary to change to a different file during a
+GDB session. Or you may run GDB and forget to specify a file you want
+to use. Or you are debugging a remote target via `gdbserver' (*note
+file: Server.). In these situations the GDB commands to specify new
+files are useful.
+
+`file FILENAME'
+ Use FILENAME as the program to be debugged. It is read for its
+ symbols and for the contents of pure memory. It is also the
+ program executed when you use the `run' command. If you do not
+ specify a directory and the file is not found in the GDB working
+ directory, GDB uses the environment variable `PATH' as a list of
+ directories to search, just as the shell does when looking for a
+ program to run. You can change the value of this variable, for
+ both GDB and your program, using the `path' command.
+
+ You can load unlinked object `.o' files into GDB using the `file'
+ command. You will not be able to "run" an object file, but you
+ can disassemble functions and inspect variables. Also, if the
+ underlying BFD functionality supports it, you could use `gdb
+ -write' to patch object files using this technique. Note that GDB
+ can neither interpret nor modify relocations in this case, so
+ branches and some initialized variables will appear to go to the
+ wrong place. But this feature is still handy from time to time.
+
+`file'
+ `file' with no argument makes GDB discard any information it has
+ on both executable file and the symbol table.
+
+`exec-file [ FILENAME ]'
+ Specify that the program to be run (but not the symbol table) is
+ found in FILENAME. GDB searches the environment variable `PATH'
+ if necessary to locate your program. Omitting FILENAME means to
+ discard information on the executable file.
+
+`symbol-file [ FILENAME ]'
+ Read symbol table information from file FILENAME. `PATH' is
+ searched when necessary. Use the `file' command to get both symbol
+ table and program to run from the same file.
+
+ `symbol-file' with no argument clears out GDB information on your
+ program's symbol table.
+
+ The `symbol-file' command causes GDB to forget the contents of
+ some breakpoints and auto-display expressions. This is because
+ they may contain pointers to the internal data recording symbols
+ and data types, which are part of the old symbol table data being
+ discarded inside GDB.
+
+ `symbol-file' does not repeat if you press <RET> again after
+ executing it once.
+
+ When GDB is configured for a particular environment, it
+ understands debugging information in whatever format is the
+ standard generated for that environment; you may use either a GNU
+ compiler, or other compilers that adhere to the local conventions.
+ Best results are usually obtained from GNU compilers; for example,
+ using `GCC' you can generate debugging information for optimized
+ code.
+
+ For most kinds of object files, with the exception of old SVR3
+ systems using COFF, the `symbol-file' command does not normally
+ read the symbol table in full right away. Instead, it scans the
+ symbol table quickly to find which source files and which symbols
+ are present. The details are read later, one source file at a
+ time, as they are needed.
+
+ The purpose of this two-stage reading strategy is to make GDB
+ start up faster. For the most part, it is invisible except for
+ occasional pauses while the symbol table details for a particular
+ source file are being read. (The `set verbose' command can turn
+ these pauses into messages if desired. *Note Optional Warnings
+ and Messages: Messages/Warnings.)
+
+ We have not implemented the two-stage strategy for COFF yet. When
+ the symbol table is stored in COFF format, `symbol-file' reads the
+ symbol table data in full right away. Note that "stabs-in-COFF"
+ still does the two-stage strategy, since the debug info is actually
+ in stabs format.
+
+`symbol-file [ -readnow ] FILENAME'
+`file [ -readnow ] FILENAME'
+ You can override the GDB two-stage strategy for reading symbol
+ tables by using the `-readnow' option with any of the commands that
+ load symbol table information, if you want to be sure GDB has the
+ entire symbol table available.
+
+`core-file [FILENAME]'
+`core'
+ Specify the whereabouts of a core dump file to be used as the
+ "contents of memory". Traditionally, core files contain only some
+ parts of the address space of the process that generated them; GDB
+ can access the executable file itself for other parts.
+
+ `core-file' with no argument specifies that no core file is to be
+ used.
+
+ Note that the core file is ignored when your program is actually
+ running under GDB. So, if you have been running your program and
+ you wish to debug a core file instead, you must kill the
+ subprocess in which the program is running. To do this, use the
+ `kill' command (*note Killing the Child Process: Kill Process.).
+
+`add-symbol-file FILENAME ADDRESS'
+`add-symbol-file FILENAME ADDRESS [ -readnow ]'
+`add-symbol-file FILENAME ADDRESS -s SECTION ADDRESS ...'
+ The `add-symbol-file' command reads additional symbol table
+ information from the file FILENAME. You would use this command
+ when FILENAME has been dynamically loaded (by some other means)
+ into the program that is running. ADDRESS should be the memory
+ address at which the file has been loaded; GDB cannot figure this
+ out for itself. You can additionally specify an arbitrary number
+ of `-s SECTION ADDRESS' pairs, to give an explicit section name
+ and base address for that section. You can specify any ADDRESS as
+ an expression.
+
+ The symbol table of the file FILENAME is added to the symbol table
+ originally read with the `symbol-file' command. You can use the
+ `add-symbol-file' command any number of times; the new symbol data
+ thus read keeps adding to the old. To discard all old symbol data
+ instead, use the `symbol-file' command without any arguments.
+
+ Although FILENAME is typically a shared library file, an
+ executable file, or some other object file which has been fully
+ relocated for loading into a process, you can also load symbolic
+ information from relocatable `.o' files, as long as:
+
+ * the file's symbolic information refers only to linker symbols
+ defined in that file, not to symbols defined by other object
+ files,
+
+ * every section the file's symbolic information refers to has
+ actually been loaded into the inferior, as it appears in the
+ file, and
+
+ * you can determine the address at which every section was
+ loaded, and provide these to the `add-symbol-file' command.
+
+ Some embedded operating systems, like Sun Chorus and VxWorks, can
+ load relocatable files into an already running program; such
+ systems typically make the requirements above easy to meet.
+ However, it's important to recognize that many native systems use
+ complex link procedures (`.linkonce' section factoring and C++
+ constructor table assembly, for example) that make the
+ requirements difficult to meet. In general, one cannot assume
+ that using `add-symbol-file' to read a relocatable object file's
+ symbolic information will have the same effect as linking the
+ relocatable object file into the program in the normal way.
+
+ `add-symbol-file' does not repeat if you press <RET> after using
+ it.
+
+`add-symbol-file-from-memory ADDRESS'
+ Load symbols from the given ADDRESS in a dynamically loaded object
+ file whose image is mapped directly into the inferior's memory.
+ For example, the Linux kernel maps a `syscall DSO' into each
+ process's address space; this DSO provides kernel-specific code for
+ some system calls. The argument can be any expression whose
+ evaluation yields the address of the file's shared object file
+ header. For this command to work, you must have used
+ `symbol-file' or `exec-file' commands in advance.
+
+`add-shared-symbol-files LIBRARY-FILE'
+`assf LIBRARY-FILE'
+ The `add-shared-symbol-files' command can currently be used only
+ in the Cygwin build of GDB on MS-Windows OS, where it is an alias
+ for the `dll-symbols' command (*note Cygwin Native::). GDB
+ automatically looks for shared libraries, however if GDB does not
+ find yours, you can invoke `add-shared-symbol-files'. It takes
+ one argument: the shared library's file name. `assf' is a
+ shorthand alias for `add-shared-symbol-files'.
+
+`section SECTION ADDR'
+ The `section' command changes the base address of the named
+ SECTION of the exec file to ADDR. This can be used if the exec
+ file does not contain section addresses, (such as in the `a.out'
+ format), or when the addresses specified in the file itself are
+ wrong. Each section must be changed separately. The `info files'
+ command, described below, lists all the sections and their
+ addresses.
+
+`info files'
+`info target'
+ `info files' and `info target' are synonymous; both print the
+ current target (*note Specifying a Debugging Target: Targets.),
+ including the names of the executable and core dump files
+ currently in use by GDB, and the files from which symbols were
+ loaded. The command `help target' lists all possible targets
+ rather than current ones.
+
+`maint info sections'
+ Another command that can give you extra information about program
+ sections is `maint info sections'. In addition to the section
+ information displayed by `info files', this command displays the
+ flags and file offset of each section in the executable and core
+ dump files. In addition, `maint info sections' provides the
+ following command options (which may be arbitrarily combined):
+
+ `ALLOBJ'
+ Display sections for all loaded object files, including
+ shared libraries.
+
+ `SECTIONS'
+ Display info only for named SECTIONS.
+
+ `SECTION-FLAGS'
+ Display info only for sections for which SECTION-FLAGS are
+ true. The section flags that GDB currently knows about are:
+ `ALLOC'
+ Section will have space allocated in the process when
+ loaded. Set for all sections except those containing
+ debug information.
+
+ `LOAD'
+ Section will be loaded from the file into the child
+ process memory. Set for pre-initialized code and data,
+ clear for `.bss' sections.
+
+ `RELOC'
+ Section needs to be relocated before loading.
+
+ `READONLY'
+ Section cannot be modified by the child process.
+
+ `CODE'
+ Section contains executable code only.
+
+ `DATA'
+ Section contains data only (no executable code).
+
+ `ROM'
+ Section will reside in ROM.
+
+ `CONSTRUCTOR'
+ Section contains data for constructor/destructor lists.
+
+ `HAS_CONTENTS'
+ Section is not empty.
+
+ `NEVER_LOAD'
+ An instruction to the linker to not output the section.
+
+ `COFF_SHARED_LIBRARY'
+ A notification to the linker that the section contains
+ COFF shared library information.
+
+ `IS_COMMON'
+ Section contains common symbols.
+
+`set trust-readonly-sections on'
+ Tell GDB that readonly sections in your object file really are
+ read-only (i.e. that their contents will not change). In that
+ case, GDB can fetch values from these sections out of the object
+ file, rather than from the target program. For some targets
+ (notably embedded ones), this can be a significant enhancement to
+ debugging performance.
+
+ The default is off.
+
+`set trust-readonly-sections off'
+ Tell GDB not to trust readonly sections. This means that the
+ contents of the section might change while the program is running,
+ and must therefore be fetched from the target when needed.
+
+`show trust-readonly-sections'
+ Show the current setting of trusting readonly sections.
+
+ All file-specifying commands allow both absolute and relative file
+names as arguments. GDB always converts the file name to an absolute
+file name and remembers it that way.
+
+ GDB supports GNU/Linux, MS-Windows, HP-UX, SunOS, SVr4, Irix, and
+IBM RS/6000 AIX shared libraries.
+
+ On MS-Windows GDB must be linked with the Expat library to support
+shared libraries. *Note Expat::.
+
+ GDB automatically loads symbol definitions from shared libraries
+when you use the `run' command, or when you examine a core file.
+(Before you issue the `run' command, GDB does not understand references
+to a function in a shared library, however--unless you are debugging a
+core file).
+
+ On HP-UX, if the program loads a library explicitly, GDB
+automatically loads the symbols at the time of the `shl_load' call.
+
+ There are times, however, when you may wish to not automatically load
+symbol definitions from shared libraries, such as when they are
+particularly large or there are many of them.
+
+ To control the automatic loading of shared library symbols, use the
+commands:
+
+`set auto-solib-add MODE'
+ If MODE is `on', symbols from all shared object libraries will be
+ loaded automatically when the inferior begins execution, you
+ attach to an independently started inferior, or when the dynamic
+ linker informs GDB that a new library has been loaded. If MODE is
+ `off', symbols must be loaded manually, using the `sharedlibrary'
+ command. The default value is `on'.
+
+ If your program uses lots of shared libraries with debug info that
+ takes large amounts of memory, you can decrease the GDB memory
+ footprint by preventing it from automatically loading the symbols
+ from shared libraries. To that end, type `set auto-solib-add off'
+ before running the inferior, then load each library whose debug
+ symbols you do need with `sharedlibrary REGEXP', where REGEXP is a
+ regular expression that matches the libraries whose symbols you
+ want to be loaded.
+
+`show auto-solib-add'
+ Display the current autoloading mode.
+
+ To explicitly load shared library symbols, use the `sharedlibrary'
+command:
+
+`info share REGEX'
+`info sharedlibrary REGEX'
+ Print the names of the shared libraries which are currently loaded
+ that match REGEX. If REGEX is omitted then print all shared
+ libraries that are loaded.
+
+`sharedlibrary REGEX'
+`share REGEX'
+ Load shared object library symbols for files matching a Unix
+ regular expression. As with files loaded automatically, it only
+ loads shared libraries required by your program for a core file or
+ after typing `run'. If REGEX is omitted all shared libraries
+ required by your program are loaded.
+
+`nosharedlibrary'
+ Unload all shared object library symbols. This discards all
+ symbols that have been loaded from all shared libraries. Symbols
+ from shared libraries that were loaded by explicit user requests
+ are not discarded.
+
+ Sometimes you may wish that GDB stops and gives you control when any
+of shared library events happen. Use the `set stop-on-solib-events'
+command for this:
+
+`set stop-on-solib-events'
+ This command controls whether GDB should give you control when the
+ dynamic linker notifies it about some shared library event. The
+ most common event of interest is loading or unloading of a new
+ shared library.
+
+`show stop-on-solib-events'
+ Show whether GDB stops and gives you control when shared library
+ events happen.
+
+ Shared libraries are also supported in many cross or remote debugging
+configurations. GDB needs to have access to the target's libraries;
+this can be accomplished either by providing copies of the libraries on
+the host system, or by asking GDB to automatically retrieve the
+libraries from the target. If copies of the target libraries are
+provided, they need to be the same as the target libraries, although the
+copies on the target can be stripped as long as the copies on the host
+are not.
+
+ For remote debugging, you need to tell GDB where the target
+libraries are, so that it can load the correct copies--otherwise, it
+may try to load the host's libraries. GDB has two variables to specify
+the search directories for target libraries.
+
+`set sysroot PATH'
+ Use PATH as the system root for the program being debugged. Any
+ absolute shared library paths will be prefixed with PATH; many
+ runtime loaders store the absolute paths to the shared library in
+ the target program's memory. If you use `set sysroot' to find
+ shared libraries, they need to be laid out in the same way that
+ they are on the target, with e.g. a `/lib' and `/usr/lib' hierarchy
+ under PATH.
+
+ If PATH starts with the sequence `remote:', GDB will retrieve the
+ target libraries from the remote system. This is only supported
+ when using a remote target that supports the `remote get' command
+ (*note Sending files to a remote system: File Transfer.). The
+ part of PATH following the initial `remote:' (if present) is used
+ as system root prefix on the remote file system. (1)
+
+ For targets with an MS-DOS based filesystem, such as MS-Windows and
+ SymbianOS, GDB tries prefixing a few variants of the target
+ absolute file name with PATH. But first, on Unix hosts, GDB
+ converts all backslash directory separators into forward slashes,
+ because the backslash is not a directory separator on Unix:
+
+ c:\foo\bar.dll => c:/foo/bar.dll
+
+ Then, GDB attempts prefixing the target file name with PATH, and
+ looks for the resulting file name in the host file system:
+
+ c:/foo/bar.dll => /path/to/sysroot/c:/foo/bar.dll
+
+ If that does not find the shared library, GDB tries removing the
+ `:' character from the drive spec, both for convenience, and, for
+ the case of the host file system not supporting file names with
+ colons:
+
+ c:/foo/bar.dll => /path/to/sysroot/c/foo/bar.dll
+
+ This makes it possible to have a system root that mirrors a target
+ with more than one drive. E.g., you may want to setup your local
+ copies of the target system shared libraries like so (note `c' vs
+ `z'):
+
+ `/path/to/sysroot/c/sys/bin/foo.dll'
+ `/path/to/sysroot/c/sys/bin/bar.dll'
+ `/path/to/sysroot/z/sys/bin/bar.dll'
+
+ and point the system root at `/path/to/sysroot', so that GDB can
+ find the correct copies of both `c:\sys\bin\foo.dll', and
+ `z:\sys\bin\bar.dll'.
+
+ If that still does not find the shared library, GDB tries removing
+ the whole drive spec from the target file name:
+
+ c:/foo/bar.dll => /path/to/sysroot/foo/bar.dll
+
+ This last lookup makes it possible to not care about the drive
+ name, if you don't want or need to.
+
+ The `set solib-absolute-prefix' command is an alias for `set
+ sysroot'.
+
+ You can set the default system root by using the configure-time
+ `--with-sysroot' option. If the system root is inside GDB's
+ configured binary prefix (set with `--prefix' or `--exec-prefix'),
+ then the default system root will be updated automatically if the
+ installed GDB is moved to a new location.
+
+`show sysroot'
+ Display the current shared library prefix.
+
+`set solib-search-path PATH'
+ If this variable is set, PATH is a colon-separated list of
+ directories to search for shared libraries. `solib-search-path'
+ is used after `sysroot' fails to locate the library, or if the
+ path to the library is relative instead of absolute. If you want
+ to use `solib-search-path' instead of `sysroot', be sure to set
+ `sysroot' to a nonexistent directory to prevent GDB from finding
+ your host's libraries. `sysroot' is preferred; setting it to a
+ nonexistent directory may interfere with automatic loading of
+ shared library symbols.
+
+`show solib-search-path'
+ Display the current shared library search path.
+
+`set target-file-system-kind KIND'
+ Set assumed file system kind for target reported file names.
+
+ Shared library file names as reported by the target system may not
+ make sense as is on the system GDB is running on. For example,
+ when remote debugging a target that has MS-DOS based file system
+ semantics, from a Unix host, the target may be reporting to GDB a
+ list of loaded shared libraries with file names such as
+ `c:\Windows\kernel32.dll'. On Unix hosts, there's no concept of
+ drive letters, so the `c:\' prefix is not normally understood as
+ indicating an absolute file name, and neither is the backslash
+ normally considered a directory separator character. In that case,
+ the native file system would interpret this whole absolute file
+ name as a relative file name with no directory components. This
+ would make it impossible to point GDB at a copy of the remote
+ target's shared libraries on the host using `set sysroot', and
+ impractical with `set solib-search-path'. Setting
+ `target-file-system-kind' to `dos-based' tells GDB to interpret
+ such file names similarly to how the target would, and to map them
+ to file names valid on GDB's native file system semantics. The
+ value of KIND can be `"auto"', in addition to one of the supported
+ file system kinds. In that case, GDB tries to determine the
+ appropriate file system variant based on the current target's
+ operating system (*note Configuring the Current ABI: ABI.). The
+ supported file system settings are:
+
+ `unix'
+ Instruct GDB to assume the target file system is of Unix
+ kind. Only file names starting the forward slash (`/')
+ character are considered absolute, and the directory
+ separator character is also the forward slash.
+
+ `dos-based'
+ Instruct GDB to assume the target file system is DOS based.
+ File names starting with either a forward slash, or a drive
+ letter followed by a colon (e.g., `c:'), are considered
+ absolute, and both the slash (`/') and the backslash (`\\')
+ characters are considered directory separators.
+
+ `auto'
+ Instruct GDB to use the file system kind associated with the
+ target operating system (*note Configuring the Current ABI:
+ ABI.). This is the default.
+
+ When processing file names provided by the user, GDB frequently
+needs to compare them to the file names recorded in the program's debug
+info. Normally, GDB compares just the "base names" of the files as
+strings, which is reasonably fast even for very large programs. (The
+base name of a file is the last portion of its name, after stripping
+all the leading directories.) This shortcut in comparison is based
+upon the assumption that files cannot have more than one base name.
+This is usually true, but references to files that use symlinks or
+similar filesystem facilities violate that assumption. If your program
+records files using such facilities, or if you provide file names to
+GDB using symlinks etc., you can set `basenames-may-differ' to `true'
+to instruct GDB to completely canonicalize each pair of file names it
+needs to compare. This will make file-name comparisons accurate, but
+at a price of a significant slowdown.
+
+`set basenames-may-differ'
+ Set whether a source file may have multiple base names.
+
+`show basenames-may-differ'
+ Show whether a source file may have multiple base names.
+
+ ---------- Footnotes ----------
+
+ (1) If you want to specify a local system root using a directory
+that happens to be named `remote:', you need to use some equivalent
+variant of the name like `./remote:'.
+
+
+File: gdb.info, Node: Separate Debug Files, Next: Index Files, Prev: Files, Up: GDB Files
+
+18.2 Debugging Information in Separate Files
+============================================
+
+GDB allows you to put a program's debugging information in a file
+separate from the executable itself, in a way that allows GDB to find
+and load the debugging information automatically. Since debugging
+information can be very large--sometimes larger than the executable
+code itself--some systems distribute debugging information for their
+executables in separate files, which users can install only when they
+need to debug a problem.
+
+ GDB supports two ways of specifying the separate debug info file:
+
+ * The executable contains a "debug link" that specifies the name of
+ the separate debug info file. The separate debug file's name is
+ usually `EXECUTABLE.debug', where EXECUTABLE is the name of the
+ corresponding executable file without leading directories (e.g.,
+ `ls.debug' for `/usr/bin/ls'). In addition, the debug link
+ specifies a 32-bit "Cyclic Redundancy Check" (CRC) checksum for
+ the debug file, which GDB uses to validate that the executable and
+ the debug file came from the same build.
+
+ * The executable contains a "build ID", a unique bit string that is
+ also present in the corresponding debug info file. (This is
+ supported only on some operating systems, notably those which use
+ the ELF format for binary files and the GNU Binutils.) For more
+ details about this feature, see the description of the `--build-id'
+ command-line option in *Note Command Line Options:
+ (ld.info)Options. The debug info file's name is not specified
+ explicitly by the build ID, but can be computed from the build ID,
+ see below.
+
+ Depending on the way the debug info file is specified, GDB uses two
+different methods of looking for the debug file:
+
+ * For the "debug link" method, GDB looks up the named file in the
+ directory of the executable file, then in a subdirectory of that
+ directory named `.debug', and finally under the global debug
+ directory, in a subdirectory whose name is identical to the leading
+ directories of the executable's absolute file name.
+
+ * For the "build ID" method, GDB looks in the `.build-id'
+ subdirectory of the global debug directory for a file named
+ `NN/NNNNNNNN.debug', where NN are the first 2 hex characters of
+ the build ID bit string, and NNNNNNNN are the rest of the bit
+ string. (Real build ID strings are 32 or more hex characters, not
+ 10.)
+
+ So, for example, suppose you ask GDB to debug `/usr/bin/ls', which
+has a debug link that specifies the file `ls.debug', and a build ID
+whose value in hex is `abcdef1234'. If the global debug directory is
+`/usr/lib/debug', then GDB will look for the following debug
+information files, in the indicated order:
+
+ - `/usr/lib/debug/.build-id/ab/cdef1234.debug'
+
+ - `/usr/bin/ls.debug'
+
+ - `/usr/bin/.debug/ls.debug'
+
+ - `/usr/lib/debug/usr/bin/ls.debug'.
+
+ You can set the global debugging info directory's name, and view the
+name GDB is currently using.
+
+`set debug-file-directory DIRECTORIES'
+ Set the directories which GDB searches for separate debugging
+ information files to DIRECTORY. Multiple directory components can
+ be set concatenating them by a directory separator.
+
+`show debug-file-directory'
+ Show the directories GDB searches for separate debugging
+ information files.
+
+
+ A debug link is a special section of the executable file named
+`.gnu_debuglink'. The section must contain:
+
+ * A filename, with any leading directory components removed,
+ followed by a zero byte,
+
+ * zero to three bytes of padding, as needed to reach the next
+ four-byte boundary within the section, and
+
+ * a four-byte CRC checksum, stored in the same endianness used for
+ the executable file itself. The checksum is computed on the
+ debugging information file's full contents by the function given
+ below, passing zero as the CRC argument.
+
+ Any executable file format can carry a debug link, as long as it can
+contain a section named `.gnu_debuglink' with the contents described
+above.
+
+ The build ID is a special section in the executable file (and in
+other ELF binary files that GDB may consider). This section is often
+named `.note.gnu.build-id', but that name is not mandatory. It
+contains unique identification for the built files--the ID remains the
+same across multiple builds of the same build tree. The default
+algorithm SHA1 produces 160 bits (40 hexadecimal characters) of the
+content for the build ID string. The same section with an identical
+value is present in the original built binary with symbols, in its
+stripped variant, and in the separate debugging information file.
+
+ The debugging information file itself should be an ordinary
+executable, containing a full set of linker symbols, sections, and
+debugging information. The sections of the debugging information file
+should have the same names, addresses, and sizes as the original file,
+but they need not contain any data--much like a `.bss' section in an
+ordinary executable.
+
+ The GNU binary utilities (Binutils) package includes the `objcopy'
+utility that can produce the separated executable / debugging
+information file pairs using the following commands:
+
+ objcopy --only-keep-debug foo foo.debug
+ strip -g foo
+
+These commands remove the debugging information from the executable
+file `foo' and place it in the file `foo.debug'. You can use the
+first, second or both methods to link the two files:
+
+ * The debug link method needs the following additional command to
+ also leave behind a debug link in `foo':
+
+ objcopy --add-gnu-debuglink=foo.debug foo
+
+ Ulrich Drepper's `elfutils' package, starting with version 0.53,
+ contains a version of the `strip' command such that the command
+ `strip foo -f foo.debug' has the same functionality as the two
+ `objcopy' commands and the `ln -s' command above, together.
+
+ * Build ID gets embedded into the main executable using `ld
+ --build-id' or the GCC counterpart `gcc -Wl,--build-id'. Build ID
+ support plus compatibility fixes for debug files separation are
+ present in GNU binary utilities (Binutils) package since version
+ 2.18.
+
+The CRC used in `.gnu_debuglink' is the CRC-32 defined in IEEE 802.3
+using the polynomial:
+
+ x^32 + x^26 + x^23 + x^22 + x^16 + x^12 + x^11
+ + x^10 + x^8 + x^7 + x^5 + x^4 + x^2 + x + 1
+
+ The function is computed byte at a time, taking the least
+significant bit of each byte first. The initial pattern `0xffffffff'
+is used, to ensure leading zeros affect the CRC and the final result is
+inverted to ensure trailing zeros also affect the CRC.
+
+ _Note:_ This is the same CRC polynomial as used in handling the
+"Remote Serial Protocol" `qCRC' packet (*note GDB Remote Serial
+Protocol: Remote Protocol.). However in the case of the Remote Serial
+Protocol, the CRC is computed _most_ significant bit first, and the
+result is not inverted, so trailing zeros have no effect on the CRC
+value.
+
+ To complete the description, we show below the code of the function
+which produces the CRC used in `.gnu_debuglink'. Inverting the
+initially supplied `crc' argument means that an initial call to this
+function passing in zero will start computing the CRC using
+`0xffffffff'.
+
+ unsigned long
+ gnu_debuglink_crc32 (unsigned long crc,
+ unsigned char *buf, size_t len)
+ {
+ static const unsigned long crc32_table[256] =
+ {
+ 0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419,
+ 0x706af48f, 0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4,
+ 0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07,
+ 0x90bf1d91, 0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de,
+ 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7, 0x136c9856,
+ 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9,
+ 0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4,
+ 0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b,
+ 0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3,
+ 0x45df5c75, 0xdcd60dcf, 0xabd13d59, 0x26d930ac, 0x51de003a,
+ 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599,
+ 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
+ 0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190,
+ 0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f,
+ 0x9fbfe4a5, 0xe8b8d433, 0x7807c9a2, 0x0f00f934, 0x9609a88e,
+ 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01,
+ 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed,
+ 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950,
+ 0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3,
+ 0xfbd44c65, 0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2,
+ 0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a,
+ 0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5,
+ 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa, 0xbe0b1010,
+ 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
+ 0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17,
+ 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6,
+ 0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615,
+ 0x73dc1683, 0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8,
+ 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1, 0xf00f9344,
+ 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb,
+ 0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a,
+ 0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5,
+ 0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1,
+ 0xa6bc5767, 0x3fb506dd, 0x48b2364b, 0xd80d2bda, 0xaf0a1b4c,
+ 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef,
+ 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
+ 0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe,
+ 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31,
+ 0x2cd99e8b, 0x5bdeae1d, 0x9b64c2b0, 0xec63f226, 0x756aa39c,
+ 0x026d930a, 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713,
+ 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b,
+ 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242,
+ 0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1,
+ 0x18b74777, 0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c,
+ 0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45, 0xa00ae278,
+ 0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7,
+ 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc, 0x40df0b66,
+ 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
+ 0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605,
+ 0xcdd70693, 0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8,
+ 0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b,
+ 0x2d02ef8d
+ };
+ unsigned char *end;
+
+ crc = ~crc & 0xffffffff;
+ for (end = buf + len; buf < end; ++buf)
+ crc = crc32_table[(crc ^ *buf) & 0xff] ^ (crc >> 8);
+ return ~crc & 0xffffffff;
+ }
+
+This computation does not apply to the "build ID" method.
+
+
+File: gdb.info, Node: Index Files, Next: Symbol Errors, Prev: Separate Debug Files, Up: GDB Files
+
+18.3 Index Files Speed Up GDB
+=============================
+
+When GDB finds a symbol file, it scans the symbols in the file in order
+to construct an internal symbol table. This lets most GDB operations
+work quickly--at the cost of a delay early on. For large programs,
+this delay can be quite lengthy, so GDB provides a way to build an
+index, which speeds up startup.
+
+ The index is stored as a section in the symbol file. GDB can write
+the index to a file, then you can put it into the symbol file using
+`objcopy'.
+
+ To create an index file, use the `save gdb-index' command:
+
+`save gdb-index DIRECTORY'
+ Create an index file for each symbol file currently known by GDB.
+ Each file is named after its corresponding symbol file, with
+ `.gdb-index' appended, and is written into the given DIRECTORY.
+
+ Once you have created an index file you can merge it into your symbol
+file, here named `symfile', using `objcopy':
+
+ $ objcopy --add-section .gdb_index=symfile.gdb-index \
+ --set-section-flags .gdb_index=readonly symfile symfile
+
+ There are currently some limitation on indices. They only work when
+for DWARF debugging information, not stabs. And, they do not currently
+work for programs using Ada.
+
+
+File: gdb.info, Node: Symbol Errors, Next: Data Files, Prev: Index Files, Up: GDB Files
+
+18.4 Errors Reading Symbol Files
+================================
+
+While reading a symbol file, GDB occasionally encounters problems, such
+as symbol types it does not recognize, or known bugs in compiler
+output. By default, GDB does not notify you of such problems, since
+they are relatively common and primarily of interest to people
+debugging compilers. If you are interested in seeing information about
+ill-constructed symbol tables, you can either ask GDB to print only one
+message about each such type of problem, no matter how many times the
+problem occurs; or you can ask GDB to print more messages, to see how
+many times the problems occur, with the `set complaints' command (*note
+Optional Warnings and Messages: Messages/Warnings.).
+
+ The messages currently printed, and their meanings, include:
+
+`inner block not inside outer block in SYMBOL'
+ The symbol information shows where symbol scopes begin and end
+ (such as at the start of a function or a block of statements).
+ This error indicates that an inner scope block is not fully
+ contained in its outer scope blocks.
+
+ GDB circumvents the problem by treating the inner block as if it
+ had the same scope as the outer block. In the error message,
+ SYMBOL may be shown as "`(don't know)'" if the outer block is not a
+ function.
+
+`block at ADDRESS out of order'
+ The symbol information for symbol scope blocks should occur in
+ order of increasing addresses. This error indicates that it does
+ not do so.
+
+ GDB does not circumvent this problem, and has trouble locating
+ symbols in the source file whose symbols it is reading. (You can
+ often determine what source file is affected by specifying `set
+ verbose on'. *Note Optional Warnings and Messages:
+ Messages/Warnings.)
+
+`bad block start address patched'
+ The symbol information for a symbol scope block has a start address
+ smaller than the address of the preceding source line. This is
+ known to occur in the SunOS 4.1.1 (and earlier) C compiler.
+
+ GDB circumvents the problem by treating the symbol scope block as
+ starting on the previous source line.
+
+`bad string table offset in symbol N'
+ Symbol number N contains a pointer into the string table which is
+ larger than the size of the string table.
+
+ GDB circumvents the problem by considering the symbol to have the
+ name `foo', which may cause other problems if many symbols end up
+ with this name.
+
+`unknown symbol type `0xNN''
+ The symbol information contains new data types that GDB does not
+ yet know how to read. `0xNN' is the symbol type of the
+ uncomprehended information, in hexadecimal.
+
+ GDB circumvents the error by ignoring this symbol information.
+ This usually allows you to debug your program, though certain
+ symbols are not accessible. If you encounter such a problem and
+ feel like debugging it, you can debug `gdb' with itself, breakpoint
+ on `complain', then go up to the function `read_dbx_symtab' and
+ examine `*bufp' to see the symbol.
+
+`stub type has NULL name'
+ GDB could not find the full definition for a struct or class.
+
+`const/volatile indicator missing (ok if using g++ v1.x), got...'
+ The symbol information for a C++ member function is missing some
+ information that recent versions of the compiler should have
+ output for it.
+
+`info mismatch between compiler and debugger'
+ GDB could not parse a type specification output by the compiler.
+
+
+
+File: gdb.info, Node: Data Files, Prev: Symbol Errors, Up: GDB Files
+
+18.5 GDB Data Files
+===================
+
+GDB will sometimes read an auxiliary data file. These files are kept
+in a directory known as the "data directory".
+
+ You can set the data directory's name, and view the name GDB is
+currently using.
+
+`set data-directory DIRECTORY'
+ Set the directory which GDB searches for auxiliary data files to
+ DIRECTORY.
+
+`show data-directory'
+ Show the directory GDB searches for auxiliary data files.
+
+ You can set the default data directory by using the configure-time
+`--with-gdb-datadir' option. If the data directory is inside GDB's
+configured binary prefix (set with `--prefix' or `--exec-prefix'), then
+the default data directory will be updated automatically if the
+installed GDB is moved to a new location.
+
+ The data directory may also be specified with the `--data-directory'
+command line option. *Note Mode Options::.
+
+
+File: gdb.info, Node: Targets, Next: Remote Debugging, Prev: GDB Files, Up: Top
+
+19 Specifying a Debugging Target
+********************************
+
+A "target" is the execution environment occupied by your program.
+
+ Often, GDB runs in the same host environment as your program; in
+that case, the debugging target is specified as a side effect when you
+use the `file' or `core' commands. When you need more flexibility--for
+example, running GDB on a physically separate host, or controlling a
+standalone system over a serial port or a realtime system over a TCP/IP
+connection--you can use the `target' command to specify one of the
+target types configured for GDB (*note Commands for Managing Targets:
+Target Commands.).
+
+ It is possible to build GDB for several different "target
+architectures". When GDB is built like that, you can choose one of the
+available architectures with the `set architecture' command.
+
+`set architecture ARCH'
+ This command sets the current target architecture to ARCH. The
+ value of ARCH can be `"auto"', in addition to one of the supported
+ architectures.
+
+`show architecture'
+ Show the current target architecture.
+
+`set processor'
+`processor'
+ These are alias commands for, respectively, `set architecture' and
+ `show architecture'.
+
+* Menu:
+
+* Active Targets:: Active targets
+* Target Commands:: Commands for managing targets
+* Byte Order:: Choosing target byte order
+
+
+File: gdb.info, Node: Active Targets, Next: Target Commands, Up: Targets
+
+19.1 Active Targets
+===================
+
+There are multiple classes of targets such as: processes, executable
+files or recording sessions. Core files belong to the process class,
+making core file and process mutually exclusive. Otherwise, GDB can
+work concurrently on multiple active targets, one in each class. This
+allows you to (for example) start a process and inspect its activity,
+while still having access to the executable file after the process
+finishes. Or if you start process recording (*note Reverse
+Execution::) and `reverse-step' there, you are presented a virtual
+layer of the recording target, while the process target remains stopped
+at the chronologically last point of the process execution.
+
+ Use the `core-file' and `exec-file' commands to select a new core
+file or executable target (*note Commands to Specify Files: Files.). To
+specify as a target a process that is already running, use the `attach'
+command (*note Debugging an Already-running Process: Attach.).
+
+
+File: gdb.info, Node: Target Commands, Next: Byte Order, Prev: Active Targets, Up: Targets
+
+19.2 Commands for Managing Targets
+==================================
+
+`target TYPE PARAMETERS'
+ Connects the GDB host environment to a target machine or process.
+ A target is typically a protocol for talking to debugging
+ facilities. You use the argument TYPE to specify the type or
+ protocol of the target machine.
+
+ Further PARAMETERS are interpreted by the target protocol, but
+ typically include things like device names or host names to connect
+ with, process numbers, and baud rates.
+
+ The `target' command does not repeat if you press <RET> again
+ after executing the command.
+
+`help target'
+ Displays the names of all targets available. To display targets
+ currently selected, use either `info target' or `info files'
+ (*note Commands to Specify Files: Files.).
+
+`help target NAME'
+ Describe a particular target, including any parameters necessary to
+ select it.
+
+`set gnutarget ARGS'
+ GDB uses its own library BFD to read your files. GDB knows
+ whether it is reading an "executable", a "core", or a ".o" file;
+ however, you can specify the file format with the `set gnutarget'
+ command. Unlike most `target' commands, with `gnutarget' the
+ `target' refers to a program, not a machine.
+
+ _Warning:_ To specify a file format with `set gnutarget', you
+ must know the actual BFD name.
+
+ *Note Commands to Specify Files: Files.
+
+`show gnutarget'
+ Use the `show gnutarget' command to display what file format
+ `gnutarget' is set to read. If you have not set `gnutarget', GDB
+ will determine the file format for each file automatically, and
+ `show gnutarget' displays `The current BDF target is "auto"'.
+
+ Here are some common targets (available, or not, depending on the GDB
+configuration):
+
+`target exec PROGRAM'
+ An executable file. `target exec PROGRAM' is the same as
+ `exec-file PROGRAM'.
+
+`target core FILENAME'
+ A core dump file. `target core FILENAME' is the same as
+ `core-file FILENAME'.
+
+`target remote MEDIUM'
+ A remote system connected to GDB via a serial line or network
+ connection. This command tells GDB to use its own remote protocol
+ over MEDIUM for debugging. *Note Remote Debugging::.
+
+ For example, if you have a board connected to `/dev/ttya' on the
+ machine running GDB, you could say:
+
+ target remote /dev/ttya
+
+ `target remote' supports the `load' command. This is only useful
+ if you have some other way of getting the stub to the target
+ system, and you can put it somewhere in memory where it won't get
+ clobbered by the download.
+
+`target sim [SIMARGS] ...'
+ Builtin CPU simulator. GDB includes simulators for most
+ architectures. In general,
+ target sim
+ load
+ run
+ works; however, you cannot assume that a specific memory map,
+ device drivers, or even basic I/O is available, although some
+ simulators do provide these. For info about any
+ processor-specific simulator details, see the appropriate section
+ in *Note Embedded Processors: Embedded Processors.
+
+
+ Some configurations may include these targets as well:
+
+`target nrom DEV'
+ NetROM ROM emulator. This target only supports downloading.
+
+
+ Different targets are available on different configurations of GDB;
+your configuration may have more or fewer targets.
+
+ Many remote targets require you to download the executable's code
+once you've successfully established a connection. You may wish to
+control various aspects of this process.
+
+`set hash'
+ This command controls whether a hash mark `#' is displayed while
+ downloading a file to the remote monitor. If on, a hash mark is
+ displayed after each S-record is successfully downloaded to the
+ monitor.
+
+`show hash'
+ Show the current status of displaying the hash mark.
+
+`set debug monitor'
+ Enable or disable display of communications messages between GDB
+ and the remote monitor.
+
+`show debug monitor'
+ Show the current status of displaying communications between GDB
+ and the remote monitor.
+
+`load FILENAME'
+ Depending on what remote debugging facilities are configured into
+ GDB, the `load' command may be available. Where it exists, it is
+ meant to make FILENAME (an executable) available for debugging on
+ the remote system--by downloading, or dynamic linking, for example.
+ `load' also records the FILENAME symbol table in GDB, like the
+ `add-symbol-file' command.
+
+ If your GDB does not have a `load' command, attempting to execute
+ it gets the error message "`You can't do that when your target is
+ ...'"
+
+ The file is loaded at whatever address is specified in the
+ executable. For some object file formats, you can specify the
+ load address when you link the program; for other formats, like
+ a.out, the object file format specifies a fixed address.
+
+ Depending on the remote side capabilities, GDB may be able to load
+ programs into flash memory.
+
+ `load' does not repeat if you press <RET> again after using it.
+
+
+File: gdb.info, Node: Byte Order, Prev: Target Commands, Up: Targets
+
+19.3 Choosing Target Byte Order
+===============================
+
+Some types of processors, such as the MIPS, PowerPC, and Renesas SH,
+offer the ability to run either big-endian or little-endian byte
+orders. Usually the executable or symbol will include a bit to
+designate the endian-ness, and you will not need to worry about which
+to use. However, you may still find it useful to adjust GDB's idea of
+processor endian-ness manually.
+
+`set endian big'
+ Instruct GDB to assume the target is big-endian.
+
+`set endian little'
+ Instruct GDB to assume the target is little-endian.
+
+`set endian auto'
+ Instruct GDB to use the byte order associated with the executable.
+
+`show endian'
+ Display GDB's current idea of the target byte order.
+
+
+ Note that these commands merely adjust interpretation of symbolic
+data on the host, and that they have absolutely no effect on the target
+system.
+
+
+File: gdb.info, Node: Remote Debugging, Next: Configurations, Prev: Targets, Up: Top
+
+20 Debugging Remote Programs
+****************************
+
+If you are trying to debug a program running on a machine that cannot
+run GDB in the usual way, it is often useful to use remote debugging.
+For example, you might use remote debugging on an operating system
+kernel, or on a small system which does not have a general purpose
+operating system powerful enough to run a full-featured debugger.
+
+ Some configurations of GDB have special serial or TCP/IP interfaces
+to make this work with particular debugging targets. In addition, GDB
+comes with a generic serial protocol (specific to GDB, but not specific
+to any particular target system) which you can use if you write the
+remote stubs--the code that runs on the remote system to communicate
+with GDB.
+
+ Other remote targets may be available in your configuration of GDB;
+use `help target' to list them.
+
+* Menu:
+
+* Connecting:: Connecting to a remote target
+* File Transfer:: Sending files to a remote system
+* Server:: Using the gdbserver program
+* Remote Configuration:: Remote configuration
+* Remote Stub:: Implementing a remote stub
+
+
+File: gdb.info, Node: Connecting, Next: File Transfer, Up: Remote Debugging
+
+20.1 Connecting to a Remote Target
+==================================
+
+On the GDB host machine, you will need an unstripped copy of your
+program, since GDB needs symbol and debugging information. Start up
+GDB as usual, using the name of the local copy of your program as the
+first argument.
+
+ GDB can communicate with the target over a serial line, or over an
+IP network using TCP or UDP. In each case, GDB uses the same protocol
+for debugging your program; only the medium carrying the debugging
+packets varies. The `target remote' command establishes a connection
+to the target. Its arguments indicate which medium to use:
+
+`target remote SERIAL-DEVICE'
+ Use SERIAL-DEVICE to communicate with the target. For example, to
+ use a serial line connected to the device named `/dev/ttyb':
+
+ target remote /dev/ttyb
+
+ If you're using a serial line, you may want to give GDB the
+ `--baud' option, or use the `set remotebaud' command (*note set
+ remotebaud: Remote Configuration.) before the `target' command.
+
+`target remote `HOST:PORT''
+`target remote `tcp:HOST:PORT''
+ Debug using a TCP connection to PORT on HOST. The HOST may be
+ either a host name or a numeric IP address; PORT must be a decimal
+ number. The HOST could be the target machine itself, if it is
+ directly connected to the net, or it might be a terminal server
+ which in turn has a serial line to the target.
+
+ For example, to connect to port 2828 on a terminal server named
+ `manyfarms':
+
+ target remote manyfarms:2828
+
+ If your remote target is actually running on the same machine as
+ your debugger session (e.g. a simulator for your target running on
+ the same host), you can omit the hostname. For example, to
+ connect to port 1234 on your local machine:
+
+ target remote :1234
+ Note that the colon is still required here.
+
+`target remote `udp:HOST:PORT''
+ Debug using UDP packets to PORT on HOST. For example, to connect
+ to UDP port 2828 on a terminal server named `manyfarms':
+
+ target remote udp:manyfarms:2828
+
+ When using a UDP connection for remote debugging, you should keep
+ in mind that the `U' stands for "Unreliable". UDP can silently
+ drop packets on busy or unreliable networks, which will cause
+ havoc with your debugging session.
+
+`target remote | COMMAND'
+ Run COMMAND in the background and communicate with it using a
+ pipe. The COMMAND is a shell command, to be parsed and expanded
+ by the system's command shell, `/bin/sh'; it should expect remote
+ protocol packets on its standard input, and send replies on its
+ standard output. You could use this to run a stand-alone simulator
+ that speaks the remote debugging protocol, to make net connections
+ using programs like `ssh', or for other similar tricks.
+
+ If COMMAND closes its standard output (perhaps by exiting), GDB
+ will try to send it a `SIGTERM' signal. (If the program has
+ already exited, this will have no effect.)
+
+
+ Once the connection has been established, you can use all the usual
+commands to examine and change data. The remote program is already
+running; you can use `step' and `continue', and you do not need to use
+`run'.
+
+ Whenever GDB is waiting for the remote program, if you type the
+interrupt character (often `Ctrl-c'), GDB attempts to stop the program.
+This may or may not succeed, depending in part on the hardware and the
+serial drivers the remote system uses. If you type the interrupt
+character once again, GDB displays this prompt:
+
+ Interrupted while waiting for the program.
+ Give up (and stop debugging it)? (y or n)
+
+ If you type `y', GDB abandons the remote debugging session. (If you
+decide you want to try again later, you can use `target remote' again
+to connect once more.) If you type `n', GDB goes back to waiting.
+
+`detach'
+ When you have finished debugging the remote program, you can use
+ the `detach' command to release it from GDB control. Detaching
+ from the target normally resumes its execution, but the results
+ will depend on your particular remote stub. After the `detach'
+ command, GDB is free to connect to another target.
+
+`disconnect'
+ The `disconnect' command behaves like `detach', except that the
+ target is generally not resumed. It will wait for GDB (this
+ instance or another one) to connect and continue debugging. After
+ the `disconnect' command, GDB is again free to connect to another
+ target.
+
+`monitor CMD'
+ This command allows you to send arbitrary commands directly to the
+ remote monitor. Since GDB doesn't care about the commands it
+ sends like this, this command is the way to extend GDB--you can
+ add new commands that only the external monitor will understand
+ and implement.
+
+
+File: gdb.info, Node: File Transfer, Next: Server, Prev: Connecting, Up: Remote Debugging
+
+20.2 Sending files to a remote system
+=====================================
+
+Some remote targets offer the ability to transfer files over the same
+connection used to communicate with GDB. This is convenient for
+targets accessible through other means, e.g. GNU/Linux systems running
+`gdbserver' over a network interface. For other targets, e.g. embedded
+devices with only a single serial port, this may be the only way to
+upload or download files.
+
+ Not all remote targets support these commands.
+
+`remote put HOSTFILE TARGETFILE'
+ Copy file HOSTFILE from the host system (the machine running GDB)
+ to TARGETFILE on the target system.
+
+`remote get TARGETFILE HOSTFILE'
+ Copy file TARGETFILE from the target system to HOSTFILE on the
+ host system.
+
+`remote delete TARGETFILE'
+ Delete TARGETFILE from the target system.
+
+
diff --git a/gdb/doc/gdb.info-3 b/gdb/doc/gdb.info-3
new file mode 100644
index 0000000..8d863eb
--- /dev/null
+++ b/gdb/doc/gdb.info-3
@@ -0,0 +1,7798 @@
+This is gdb.info, produced by makeinfo version 4.8 from ./gdb.texinfo.
+
+INFO-DIR-SECTION Software development
+START-INFO-DIR-ENTRY
+* Gdb: (gdb). The GNU debugger.
+END-INFO-DIR-ENTRY
+
+ Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996,
+1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009,
+2010 Free Software Foundation, Inc.
+
+ Permission is granted to copy, distribute and/or modify this document
+under the terms of the GNU Free Documentation License, Version 1.3 or
+any later version published by the Free Software Foundation; with the
+Invariant Sections being "Free Software" and "Free Software Needs Free
+Documentation", with the Front-Cover Texts being "A GNU Manual," and
+with the Back-Cover Texts as in (a) below.
+
+ (a) The FSF's Back-Cover Text is: "You are free to copy and modify
+this GNU Manual. Buying copies from GNU Press supports the FSF in
+developing GNU and promoting software freedom."
+
+ This file documents the GNU debugger GDB.
+
+ This is the Tenth Edition, of `Debugging with GDB: the GNU
+Source-Level Debugger' for GDB (GDB) Version 7.4.1.
+
+ Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996,
+1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009,
+2010 Free Software Foundation, Inc.
+
+ Permission is granted to copy, distribute and/or modify this document
+under the terms of the GNU Free Documentation License, Version 1.3 or
+any later version published by the Free Software Foundation; with the
+Invariant Sections being "Free Software" and "Free Software Needs Free
+Documentation", with the Front-Cover Texts being "A GNU Manual," and
+with the Back-Cover Texts as in (a) below.
+
+ (a) The FSF's Back-Cover Text is: "You are free to copy and modify
+this GNU Manual. Buying copies from GNU Press supports the FSF in
+developing GNU and promoting software freedom."
+
+
+File: gdb.info, Node: Server, Next: Remote Configuration, Prev: File Transfer, Up: Remote Debugging
+
+20.3 Using the `gdbserver' Program
+==================================
+
+`gdbserver' is a control program for Unix-like systems, which allows
+you to connect your program with a remote GDB via `target remote'--but
+without linking in the usual debugging stub.
+
+ `gdbserver' is not a complete replacement for the debugging stubs,
+because it requires essentially the same operating-system facilities
+that GDB itself does. In fact, a system that can run `gdbserver' to
+connect to a remote GDB could also run GDB locally! `gdbserver' is
+sometimes useful nevertheless, because it is a much smaller program
+than GDB itself. It is also easier to port than all of GDB, so you may
+be able to get started more quickly on a new system by using
+`gdbserver'. Finally, if you develop code for real-time systems, you
+may find that the tradeoffs involved in real-time operation make it
+more convenient to do as much development work as possible on another
+system, for example by cross-compiling. You can use `gdbserver' to
+make a similar choice for debugging.
+
+ GDB and `gdbserver' communicate via either a serial line or a TCP
+connection, using the standard GDB remote serial protocol.
+
+ _Warning:_ `gdbserver' does not have any built-in security. Do
+ not run `gdbserver' connected to any public network; a GDB
+ connection to `gdbserver' provides access to the target system
+ with the same privileges as the user running `gdbserver'.
+
+20.3.1 Running `gdbserver'
+--------------------------
+
+Run `gdbserver' on the target system. You need a copy of the program
+you want to debug, including any libraries it requires. `gdbserver'
+does not need your program's symbol table, so you can strip the program
+if necessary to save space. GDB on the host system does all the symbol
+handling.
+
+ To use the server, you must tell it how to communicate with GDB; the
+name of your program; and the arguments for your program. The usual
+syntax is:
+
+ target> gdbserver COMM PROGRAM [ ARGS ... ]
+
+ COMM is either a device name (to use a serial line) or a TCP
+hostname and portnumber. For example, to debug Emacs with the argument
+`foo.txt' and communicate with GDB over the serial port `/dev/com1':
+
+ target> gdbserver /dev/com1 emacs foo.txt
+
+ `gdbserver' waits passively for the host GDB to communicate with it.
+
+ To use a TCP connection instead of a serial line:
+
+ target> gdbserver host:2345 emacs foo.txt
+
+ The only difference from the previous example is the first argument,
+specifying that you are communicating with the host GDB via TCP. The
+`host:2345' argument means that `gdbserver' is to expect a TCP
+connection from machine `host' to local TCP port 2345. (Currently, the
+`host' part is ignored.) You can choose any number you want for the
+port number as long as it does not conflict with any TCP ports already
+in use on the target system (for example, `23' is reserved for
+`telnet').(1) You must use the same port number with the host GDB
+`target remote' command.
+
+20.3.1.1 Attaching to a Running Program
+.......................................
+
+On some targets, `gdbserver' can also attach to running programs. This
+is accomplished via the `--attach' argument. The syntax is:
+
+ target> gdbserver --attach COMM PID
+
+ PID is the process ID of a currently running process. It isn't
+necessary to point `gdbserver' at a binary for the running process.
+
+ You can debug processes by name instead of process ID if your target
+has the `pidof' utility:
+
+ target> gdbserver --attach COMM `pidof PROGRAM`
+
+ In case more than one copy of PROGRAM is running, or PROGRAM has
+multiple threads, most versions of `pidof' support the `-s' option to
+only return the first process ID.
+
+20.3.1.2 Multi-Process Mode for `gdbserver'
+...........................................
+
+When you connect to `gdbserver' using `target remote', `gdbserver'
+debugs the specified program only once. When the program exits, or you
+detach from it, GDB closes the connection and `gdbserver' exits.
+
+ If you connect using `target extended-remote', `gdbserver' enters
+multi-process mode. When the debugged program exits, or you detach
+from it, GDB stays connected to `gdbserver' even though no program is
+running. The `run' and `attach' commands instruct `gdbserver' to run
+or attach to a new program. The `run' command uses `set remote
+exec-file' (*note set remote exec-file::) to select the program to run.
+Command line arguments are supported, except for wildcard expansion
+and I/O redirection (*note Arguments::).
+
+ To start `gdbserver' without supplying an initial command to run or
+process ID to attach, use the `--multi' command line option. Then you
+can connect using `target extended-remote' and start the program you
+want to debug.
+
+ In multi-process mode `gdbserver' does not automatically exit unless
+you use the option `--once'. You can terminate it by using `monitor
+exit' (*note Monitor Commands for gdbserver::). Note that the
+conditions under which `gdbserver' terminates depend on how GDB
+connects to it (`target remote' or `target extended-remote'). The
+`--multi' option to `gdbserver' has no influence on that.
+
+20.3.1.3 TCP port allocation lifecycle of `gdbserver'
+.....................................................
+
+This section applies only when `gdbserver' is run to listen on a TCP
+port.
+
+ `gdbserver' normally terminates after all of its debugged processes
+have terminated in `target remote' mode. On the other hand, for `target
+extended-remote', `gdbserver' stays running even with no processes left.
+GDB normally terminates the spawned debugged process on its exit, which
+normally also terminates `gdbserver' in the `target remote' mode.
+Therefore, when the connection drops unexpectedly, and GDB cannot ask
+`gdbserver' to kill its debugged processes, `gdbserver' stays running
+even in the `target remote' mode.
+
+ When `gdbserver' stays running, GDB can connect to it again later.
+Such reconnecting is useful for features like *Note disconnected
+tracing::. For completeness, at most one GDB can be connected at a
+time.
+
+ By default, `gdbserver' keeps the listening TCP port open, so that
+additional connections are possible. However, if you start `gdbserver'
+with the `--once' option, it will stop listening for any further
+connection attempts after connecting to the first GDB session. This
+means no further connections to `gdbserver' will be possible after the
+first one. It also means `gdbserver' will terminate after the first
+connection with remote GDB has closed, even for unexpectedly closed
+connections and even in the `target extended-remote' mode. The
+`--once' option allows reusing the same port number for connecting to
+multiple instances of `gdbserver' running on the same host, since each
+instance closes its port after the first connection.
+
+20.3.1.4 Other Command-Line Arguments for `gdbserver'
+.....................................................
+
+The `--debug' option tells `gdbserver' to display extra status
+information about the debugging process. The `--remote-debug' option
+tells `gdbserver' to display remote protocol debug output. These
+options are intended for `gdbserver' development and for bug reports to
+the developers.
+
+ The `--wrapper' option specifies a wrapper to launch programs for
+debugging. The option should be followed by the name of the wrapper,
+then any command-line arguments to pass to the wrapper, then `--'
+indicating the end of the wrapper arguments.
+
+ `gdbserver' runs the specified wrapper program with a combined
+command line including the wrapper arguments, then the name of the
+program to debug, then any arguments to the program. The wrapper runs
+until it executes your program, and then GDB gains control.
+
+ You can use any program that eventually calls `execve' with its
+arguments as a wrapper. Several standard Unix utilities do this, e.g.
+`env' and `nohup'. Any Unix shell script ending with `exec "$@"' will
+also work.
+
+ For example, you can use `env' to pass an environment variable to
+the debugged program, without setting the variable in `gdbserver''s
+environment:
+
+ $ gdbserver --wrapper env LD_PRELOAD=libtest.so -- :2222 ./testprog
+
+20.3.2 Connecting to `gdbserver'
+--------------------------------
+
+Run GDB on the host system.
+
+ First make sure you have the necessary symbol files. Load symbols
+for your application using the `file' command before you connect. Use
+`set sysroot' to locate target libraries (unless your GDB was compiled
+with the correct sysroot using `--with-sysroot').
+
+ The symbol file and target libraries must exactly match the
+executable and libraries on the target, with one exception: the files
+on the host system should not be stripped, even if the files on the
+target system are. Mismatched or missing files will lead to confusing
+results during debugging. On GNU/Linux targets, mismatched or missing
+files may also prevent `gdbserver' from debugging multi-threaded
+programs.
+
+ Connect to your target (*note Connecting to a Remote Target:
+Connecting.). For TCP connections, you must start up `gdbserver' prior
+to using the `target remote' command. Otherwise you may get an error
+whose text depends on the host system, but which usually looks
+something like `Connection refused'. Don't use the `load' command in
+GDB when using `gdbserver', since the program is already on the target.
+
+20.3.3 Monitor Commands for `gdbserver'
+---------------------------------------
+
+During a GDB session using `gdbserver', you can use the `monitor'
+command to send special requests to `gdbserver'. Here are the
+available commands.
+
+`monitor help'
+ List the available monitor commands.
+
+`monitor set debug 0'
+`monitor set debug 1'
+ Disable or enable general debugging messages.
+
+`monitor set remote-debug 0'
+`monitor set remote-debug 1'
+ Disable or enable specific debugging messages associated with the
+ remote protocol (*note Remote Protocol::).
+
+`monitor set libthread-db-search-path [PATH]'
+ When this command is issued, PATH is a colon-separated list of
+ directories to search for `libthread_db' (*note set
+ libthread-db-search-path: Threads.). If you omit PATH,
+ `libthread-db-search-path' will be reset to its default value.
+
+ The special entry `$pdir' for `libthread-db-search-path' is not
+ supported in `gdbserver'.
+
+`monitor exit'
+ Tell gdbserver to exit immediately. This command should be
+ followed by `disconnect' to close the debugging session.
+ `gdbserver' will detach from any attached processes and kill any
+ processes it created. Use `monitor exit' to terminate `gdbserver'
+ at the end of a multi-process mode debug session.
+
+
+20.3.4 Tracepoints support in `gdbserver'
+-----------------------------------------
+
+On some targets, `gdbserver' supports tracepoints, fast tracepoints and
+static tracepoints.
+
+ For fast or static tracepoints to work, a special library called the
+"in-process agent" (IPA), must be loaded in the inferior process. This
+library is built and distributed as an integral part of `gdbserver'.
+In addition, support for static tracepoints requires building the
+in-process agent library with static tracepoints support. At present,
+the UST (LTTng Userspace Tracer, `http://lttng.org/ust') tracing engine
+is supported. This support is automatically available if UST
+development headers are found in the standard include path when
+`gdbserver' is built, or if `gdbserver' was explicitly configured using
+`--with-ust' to point at such headers. You can explicitly disable the
+support using `--with-ust=no'.
+
+ There are several ways to load the in-process agent in your program:
+
+`Specifying it as dependency at link time'
+ You can link your program dynamically with the in-process agent
+ library. On most systems, this is accomplished by adding
+ `-linproctrace' to the link command.
+
+`Using the system's preloading mechanisms'
+ You can force loading the in-process agent at startup time by using
+ your system's support for preloading shared libraries. Many Unixes
+ support the concept of preloading user defined libraries. In most
+ cases, you do that by specifying `LD_PRELOAD=libinproctrace.so' in
+ the environment. See also the description of `gdbserver''s
+ `--wrapper' command line option.
+
+`Using GDB to force loading the agent at run time'
+ On some systems, you can force the inferior to load a shared
+ library, by calling a dynamic loader function in the inferior that
+ takes care of dynamically looking up and loading a shared library.
+ On most Unix systems, the function is `dlopen'. You'll use the
+ `call' command for that. For example:
+
+ (gdb) call dlopen ("libinproctrace.so", ...)
+
+ Note that on most Unix systems, for the `dlopen' function to be
+ available, the program needs to be linked with `-ldl'.
+
+ On systems that have a userspace dynamic loader, like most Unix
+systems, when you connect to `gdbserver' using `target remote', you'll
+find that the program is stopped at the dynamic loader's entry point,
+and no shared library has been loaded in the program's address space
+yet, including the in-process agent. In that case, before being able
+to use any of the fast or static tracepoints features, you need to let
+the loader run and load the shared libraries. The simplest way to do
+that is to run the program to the main procedure. E.g., if debugging a
+C or C++ program, start `gdbserver' like so:
+
+ $ gdbserver :9999 myprogram
+
+ Start GDB and connect to `gdbserver' like so, and run to main:
+
+ $ gdb myprogram
+ (gdb) target remote myhost:9999
+ 0x00007f215893ba60 in ?? () from /lib64/ld-linux-x86-64.so.2
+ (gdb) b main
+ (gdb) continue
+
+ The in-process tracing agent library should now be loaded into the
+process; you can confirm it with the `info sharedlibrary' command,
+which will list `libinproctrace.so' as loaded in the process. You are
+now ready to install fast tracepoints, list static tracepoint markers,
+probe static tracepoints markers, and start tracing.
+
+ ---------- Footnotes ----------
+
+ (1) If you choose a port number that conflicts with another service,
+`gdbserver' prints an error message and exits.
+
+
+File: gdb.info, Node: Remote Configuration, Next: Remote Stub, Prev: Server, Up: Remote Debugging
+
+20.4 Remote Configuration
+=========================
+
+This section documents the configuration options available when
+debugging remote programs. For the options related to the File I/O
+extensions of the remote protocol, see *Note system-call-allowed:
+system.
+
+`set remoteaddresssize BITS'
+ Set the maximum size of address in a memory packet to the specified
+ number of bits. GDB will mask off the address bits above that
+ number, when it passes addresses to the remote target. The
+ default value is the number of bits in the target's address.
+
+`show remoteaddresssize'
+ Show the current value of remote address size in bits.
+
+`set remotebaud N'
+ Set the baud rate for the remote serial I/O to N baud. The value
+ is used to set the speed of the serial port used for debugging
+ remote targets.
+
+`show remotebaud'
+ Show the current speed of the remote connection.
+
+`set remotebreak'
+ If set to on, GDB sends a `BREAK' signal to the remote when you
+ type `Ctrl-c' to interrupt the program running on the remote. If
+ set to off, GDB sends the `Ctrl-C' character instead. The default
+ is off, since most remote systems expect to see `Ctrl-C' as the
+ interrupt signal.
+
+`show remotebreak'
+ Show whether GDB sends `BREAK' or `Ctrl-C' to interrupt the remote
+ program.
+
+`set remoteflow on'
+`set remoteflow off'
+ Enable or disable hardware flow control (`RTS'/`CTS') on the
+ serial port used to communicate to the remote target.
+
+`show remoteflow'
+ Show the current setting of hardware flow control.
+
+`set remotelogbase BASE'
+ Set the base (a.k.a. radix) of logging serial protocol
+ communications to BASE. Supported values of BASE are: `ascii',
+ `octal', and `hex'. The default is `ascii'.
+
+`show remotelogbase'
+ Show the current setting of the radix for logging remote serial
+ protocol.
+
+`set remotelogfile FILE'
+ Record remote serial communications on the named FILE. The
+ default is not to record at all.
+
+`show remotelogfile.'
+ Show the current setting of the file name on which to record the
+ serial communications.
+
+`set remotetimeout NUM'
+ Set the timeout limit to wait for the remote target to respond to
+ NUM seconds. The default is 2 seconds.
+
+`show remotetimeout'
+ Show the current number of seconds to wait for the remote target
+ responses.
+
+`set remote hardware-watchpoint-limit LIMIT'
+`set remote hardware-breakpoint-limit LIMIT'
+ Restrict GDB to using LIMIT remote hardware breakpoint or
+ watchpoints. A limit of -1, the default, is treated as unlimited.
+
+`set remote hardware-watchpoint-length-limit LIMIT'
+ Restrict GDB to using LIMIT bytes for the maximum length of a
+ remote hardware watchpoint. A limit of -1, the default, is treated
+ as unlimited.
+
+`show remote hardware-watchpoint-length-limit'
+ Show the current limit (in bytes) of the maximum length of a
+ remote hardware watchpoint.
+
+`set remote exec-file FILENAME'
+`show remote exec-file'
+ Select the file used for `run' with `target extended-remote'.
+ This should be set to a filename valid on the target system. If
+ it is not set, the target will use a default filename (e.g. the
+ last program run).
+
+`set remote interrupt-sequence'
+ Allow the user to select one of `Ctrl-C', a `BREAK' or `BREAK-g'
+ as the sequence to the remote target in order to interrupt the
+ execution. `Ctrl-C' is a default. Some system prefers `BREAK'
+ which is high level of serial line for some certain time. Linux
+ kernel prefers `BREAK-g', a.k.a Magic SysRq g. It is `BREAK'
+ signal followed by character `g'.
+
+`show interrupt-sequence'
+ Show which of `Ctrl-C', `BREAK' or `BREAK-g' is sent by GDB to
+ interrupt the remote program. `BREAK-g' is BREAK signal followed
+ by `g' and also known as Magic SysRq g.
+
+`set remote interrupt-on-connect'
+ Specify whether interrupt-sequence is sent to remote target when
+ GDB connects to it. This is mostly needed when you debug Linux
+ kernel. Linux kernel expects `BREAK' followed by `g' which is
+ known as Magic SysRq g in order to connect GDB.
+
+`show interrupt-on-connect'
+ Show whether interrupt-sequence is sent to remote target when GDB
+ connects to it.
+
+`set tcp auto-retry on'
+ Enable auto-retry for remote TCP connections. This is useful if
+ the remote debugging agent is launched in parallel with GDB; there
+ is a race condition because the agent may not become ready to
+ accept the connection before GDB attempts to connect. When
+ auto-retry is enabled, if the initial attempt to connect fails,
+ GDB reattempts to establish the connection using the timeout
+ specified by `set tcp connect-timeout'.
+
+`set tcp auto-retry off'
+ Do not auto-retry failed TCP connections.
+
+`show tcp auto-retry'
+ Show the current auto-retry setting.
+
+`set tcp connect-timeout SECONDS'
+ Set the timeout for establishing a TCP connection to the remote
+ target to SECONDS. The timeout affects both polling to retry
+ failed connections (enabled by `set tcp auto-retry on') and
+ waiting for connections that are merely slow to complete, and
+ represents an approximate cumulative value.
+
+`show tcp connect-timeout'
+ Show the current connection timeout setting.
+
+ The GDB remote protocol autodetects the packets supported by your
+debugging stub. If you need to override the autodetection, you can use
+these commands to enable or disable individual packets. Each packet
+can be set to `on' (the remote target supports this packet), `off' (the
+remote target does not support this packet), or `auto' (detect remote
+target support for this packet). They all default to `auto'. For more
+information about each packet, see *Note Remote Protocol::.
+
+ During normal use, you should not have to use any of these commands.
+If you do, that may be a bug in your remote debugging stub, or a bug in
+GDB. You may want to report the problem to the GDB developers.
+
+ For each packet NAME, the command to enable or disable the packet is
+`set remote NAME-packet'. The available settings are:
+
+Command Name Remote Packet Related Features
+`fetch-register' `p' `info registers'
+`set-register' `P' `set'
+`binary-download' `X' `load', `set'
+`read-aux-vector' `qXfer:auxv:read' `info auxv'
+`symbol-lookup' `qSymbol' Detecting
+ multiple threads
+`attach' `vAttach' `attach'
+`verbose-resume' `vCont' Stepping or
+ resuming multiple
+ threads
+`run' `vRun' `run'
+`software-breakpoint'`Z0' `break'
+`hardware-breakpoint'`Z1' `hbreak'
+`write-watchpoint' `Z2' `watch'
+`read-watchpoint' `Z3' `rwatch'
+`access-watchpoint' `Z4' `awatch'
+`target-features' `qXfer:features:read' `set architecture'
+`library-info' `qXfer:libraries:read' `info
+ sharedlibrary'
+`memory-map' `qXfer:memory-map:read' `info mem'
+`read-sdata-object' `qXfer:sdata:read' `print $_sdata'
+`read-spu-object' `qXfer:spu:read' `info spu'
+`write-spu-object' `qXfer:spu:write' `info spu'
+`read-siginfo-object'`qXfer:siginfo:read' `print $_siginfo'
+`write-siginfo-object'`qXfer:siginfo:write' `set $_siginfo'
+`threads' `qXfer:threads:read' `info threads'
+`get-thread-local- `qGetTLSAddr' Displaying
+storage-address' `__thread'
+ variables
+`get-thread-information-block-address'`qGetTIBAddr' Display
+ MS-Windows Thread
+ Information Block.
+`search-memory' `qSearch:memory' `find'
+`supported-packets' `qSupported' Remote
+ communications
+ parameters
+`pass-signals' `QPassSignals' `handle SIGNAL'
+`hostio-close-packet'`vFile:close' `remote get',
+ `remote put'
+`hostio-open-packet' `vFile:open' `remote get',
+ `remote put'
+`hostio-pread-packet'`vFile:pread' `remote get',
+ `remote put'
+`hostio-pwrite-packet'`vFile:pwrite' `remote get',
+ `remote put'
+`hostio-unlink-packet'`vFile:unlink' `remote delete'
+`noack-packet' `QStartNoAckMode' Packet
+ acknowledgment
+`osdata' `qXfer:osdata:read' `info os'
+`query-attached' `qAttached' Querying remote
+ process attach
+ state.
+`traceframe-info' `qXfer:traceframe-info:read'Traceframe info
+`install-in-trace' `InstallInTrace' Install
+ tracepoint in
+ tracing
+`disable-randomization'`QDisableRandomization' `set
+ disable-randomization'
+
+
+File: gdb.info, Node: Remote Stub, Prev: Remote Configuration, Up: Remote Debugging
+
+20.5 Implementing a Remote Stub
+===============================
+
+The stub files provided with GDB implement the target side of the
+communication protocol, and the GDB side is implemented in the GDB
+source file `remote.c'. Normally, you can simply allow these
+subroutines to communicate, and ignore the details. (If you're
+implementing your own stub file, you can still ignore the details: start
+with one of the existing stub files. `sparc-stub.c' is the best
+organized, and therefore the easiest to read.)
+
+ To debug a program running on another machine (the debugging
+"target" machine), you must first arrange for all the usual
+prerequisites for the program to run by itself. For example, for a C
+program, you need:
+
+ 1. A startup routine to set up the C runtime environment; these
+ usually have a name like `crt0'. The startup routine may be
+ supplied by your hardware supplier, or you may have to write your
+ own.
+
+ 2. A C subroutine library to support your program's subroutine calls,
+ notably managing input and output.
+
+ 3. A way of getting your program to the other machine--for example, a
+ download program. These are often supplied by the hardware
+ manufacturer, but you may have to write your own from hardware
+ documentation.
+
+ The next step is to arrange for your program to use a serial port to
+communicate with the machine where GDB is running (the "host" machine).
+In general terms, the scheme looks like this:
+
+_On the host,_
+ GDB already understands how to use this protocol; when everything
+ else is set up, you can simply use the `target remote' command
+ (*note Specifying a Debugging Target: Targets.).
+
+_On the target,_
+ you must link with your program a few special-purpose subroutines
+ that implement the GDB remote serial protocol. The file
+ containing these subroutines is called a "debugging stub".
+
+ On certain remote targets, you can use an auxiliary program
+ `gdbserver' instead of linking a stub into your program. *Note
+ Using the `gdbserver' Program: Server, for details.
+
+ The debugging stub is specific to the architecture of the remote
+machine; for example, use `sparc-stub.c' to debug programs on SPARC
+boards.
+
+ These working remote stubs are distributed with GDB:
+
+`i386-stub.c'
+ For Intel 386 and compatible architectures.
+
+`m68k-stub.c'
+ For Motorola 680x0 architectures.
+
+`sh-stub.c'
+ For Renesas SH architectures.
+
+`sparc-stub.c'
+ For SPARC architectures.
+
+`sparcl-stub.c'
+ For Fujitsu SPARCLITE architectures.
+
+
+ The `README' file in the GDB distribution may list other recently
+added stubs.
+
+* Menu:
+
+* Stub Contents:: What the stub can do for you
+* Bootstrapping:: What you must do for the stub
+* Debug Session:: Putting it all together
+
+
+File: gdb.info, Node: Stub Contents, Next: Bootstrapping, Up: Remote Stub
+
+20.5.1 What the Stub Can Do for You
+-----------------------------------
+
+The debugging stub for your architecture supplies these three
+subroutines:
+
+`set_debug_traps'
+ This routine arranges for `handle_exception' to run when your
+ program stops. You must call this subroutine explicitly near the
+ beginning of your program.
+
+`handle_exception'
+ This is the central workhorse, but your program never calls it
+ explicitly--the setup code arranges for `handle_exception' to run
+ when a trap is triggered.
+
+ `handle_exception' takes control when your program stops during
+ execution (for example, on a breakpoint), and mediates
+ communications with GDB on the host machine. This is where the
+ communications protocol is implemented; `handle_exception' acts as
+ the GDB representative on the target machine. It begins by
+ sending summary information on the state of your program, then
+ continues to execute, retrieving and transmitting any information
+ GDB needs, until you execute a GDB command that makes your program
+ resume; at that point, `handle_exception' returns control to your
+ own code on the target machine.
+
+`breakpoint'
+ Use this auxiliary subroutine to make your program contain a
+ breakpoint. Depending on the particular situation, this may be
+ the only way for GDB to get control. For instance, if your target
+ machine has some sort of interrupt button, you won't need to call
+ this; pressing the interrupt button transfers control to
+ `handle_exception'--in effect, to GDB. On some machines, simply
+ receiving characters on the serial port may also trigger a trap;
+ again, in that situation, you don't need to call `breakpoint' from
+ your own program--simply running `target remote' from the host GDB
+ session gets control.
+
+ Call `breakpoint' if none of these is true, or if you simply want
+ to make certain your program stops at a predetermined point for the
+ start of your debugging session.
+
+
+File: gdb.info, Node: Bootstrapping, Next: Debug Session, Prev: Stub Contents, Up: Remote Stub
+
+20.5.2 What You Must Do for the Stub
+------------------------------------
+
+The debugging stubs that come with GDB are set up for a particular chip
+architecture, but they have no information about the rest of your
+debugging target machine.
+
+ First of all you need to tell the stub how to communicate with the
+serial port.
+
+`int getDebugChar()'
+ Write this subroutine to read a single character from the serial
+ port. It may be identical to `getchar' for your target system; a
+ different name is used to allow you to distinguish the two if you
+ wish.
+
+`void putDebugChar(int)'
+ Write this subroutine to write a single character to the serial
+ port. It may be identical to `putchar' for your target system; a
+ different name is used to allow you to distinguish the two if you
+ wish.
+
+ If you want GDB to be able to stop your program while it is running,
+you need to use an interrupt-driven serial driver, and arrange for it
+to stop when it receives a `^C' (`\003', the control-C character).
+That is the character which GDB uses to tell the remote system to stop.
+
+ Getting the debugging target to return the proper status to GDB
+probably requires changes to the standard stub; one quick and dirty way
+is to just execute a breakpoint instruction (the "dirty" part is that
+GDB reports a `SIGTRAP' instead of a `SIGINT').
+
+ Other routines you need to supply are:
+
+`void exceptionHandler (int EXCEPTION_NUMBER, void *EXCEPTION_ADDRESS)'
+ Write this function to install EXCEPTION_ADDRESS in the exception
+ handling tables. You need to do this because the stub does not
+ have any way of knowing what the exception handling tables on your
+ target system are like (for example, the processor's table might
+ be in ROM, containing entries which point to a table in RAM).
+ EXCEPTION_NUMBER is the exception number which should be changed;
+ its meaning is architecture-dependent (for example, different
+ numbers might represent divide by zero, misaligned access, etc).
+ When this exception occurs, control should be transferred directly
+ to EXCEPTION_ADDRESS, and the processor state (stack, registers,
+ and so on) should be just as it is when a processor exception
+ occurs. So if you want to use a jump instruction to reach
+ EXCEPTION_ADDRESS, it should be a simple jump, not a jump to
+ subroutine.
+
+ For the 386, EXCEPTION_ADDRESS should be installed as an interrupt
+ gate so that interrupts are masked while the handler runs. The
+ gate should be at privilege level 0 (the most privileged level).
+ The SPARC and 68k stubs are able to mask interrupts themselves
+ without help from `exceptionHandler'.
+
+`void flush_i_cache()'
+ On SPARC and SPARCLITE only, write this subroutine to flush the
+ instruction cache, if any, on your target machine. If there is no
+ instruction cache, this subroutine may be a no-op.
+
+ On target machines that have instruction caches, GDB requires this
+ function to make certain that the state of your program is stable.
+
+You must also make sure this library routine is available:
+
+`void *memset(void *, int, int)'
+ This is the standard library function `memset' that sets an area of
+ memory to a known value. If you have one of the free versions of
+ `libc.a', `memset' can be found there; otherwise, you must either
+ obtain it from your hardware manufacturer, or write your own.
+
+ If you do not use the GNU C compiler, you may need other standard
+library subroutines as well; this varies from one stub to another, but
+in general the stubs are likely to use any of the common library
+subroutines which `GCC' generates as inline code.
+
+
+File: gdb.info, Node: Debug Session, Prev: Bootstrapping, Up: Remote Stub
+
+20.5.3 Putting it All Together
+------------------------------
+
+In summary, when your program is ready to debug, you must follow these
+steps.
+
+ 1. Make sure you have defined the supporting low-level routines
+ (*note What You Must Do for the Stub: Bootstrapping.):
+ `getDebugChar', `putDebugChar',
+ `flush_i_cache', `memset', `exceptionHandler'.
+
+ 2. Insert these lines near the top of your program:
+
+ set_debug_traps();
+ breakpoint();
+
+ 3. For the 680x0 stub only, you need to provide a variable called
+ `exceptionHook'. Normally you just use:
+
+ void (*exceptionHook)() = 0;
+
+ but if before calling `set_debug_traps', you set it to point to a
+ function in your program, that function is called when `GDB'
+ continues after stopping on a trap (for example, bus error). The
+ function indicated by `exceptionHook' is called with one
+ parameter: an `int' which is the exception number.
+
+ 4. Compile and link together: your program, the GDB debugging stub for
+ your target architecture, and the supporting subroutines.
+
+ 5. Make sure you have a serial connection between your target machine
+ and the GDB host, and identify the serial port on the host.
+
+ 6. Download your program to your target machine (or get it there by
+ whatever means the manufacturer provides), and start it.
+
+ 7. Start GDB on the host, and connect to the target (*note Connecting
+ to a Remote Target: Connecting.).
+
+
+
+File: gdb.info, Node: Configurations, Next: Controlling GDB, Prev: Remote Debugging, Up: Top
+
+21 Configuration-Specific Information
+*************************************
+
+While nearly all GDB commands are available for all native and cross
+versions of the debugger, there are some exceptions. This chapter
+describes things that are only available in certain configurations.
+
+ There are three major categories of configurations: native
+configurations, where the host and target are the same, embedded
+operating system configurations, which are usually the same for several
+different processor architectures, and bare embedded processors, which
+are quite different from each other.
+
+* Menu:
+
+* Native::
+* Embedded OS::
+* Embedded Processors::
+* Architectures::
+
+
+File: gdb.info, Node: Native, Next: Embedded OS, Up: Configurations
+
+21.1 Native
+===========
+
+This section describes details specific to particular native
+configurations.
+
+* Menu:
+
+* HP-UX:: HP-UX
+* BSD libkvm Interface:: Debugging BSD kernel memory images
+* SVR4 Process Information:: SVR4 process information
+* DJGPP Native:: Features specific to the DJGPP port
+* Cygwin Native:: Features specific to the Cygwin port
+* Hurd Native:: Features specific to GNU Hurd
+* Neutrino:: Features specific to QNX Neutrino
+* Darwin:: Features specific to Darwin
+
+
+File: gdb.info, Node: HP-UX, Next: BSD libkvm Interface, Up: Native
+
+21.1.1 HP-UX
+------------
+
+On HP-UX systems, if you refer to a function or variable name that
+begins with a dollar sign, GDB searches for a user or system name
+first, before it searches for a convenience variable.
+
+
+File: gdb.info, Node: BSD libkvm Interface, Next: SVR4 Process Information, Prev: HP-UX, Up: Native
+
+21.1.2 BSD libkvm Interface
+---------------------------
+
+BSD-derived systems (FreeBSD/NetBSD/OpenBSD) have a kernel memory
+interface that provides a uniform interface for accessing kernel virtual
+memory images, including live systems and crash dumps. GDB uses this
+interface to allow you to debug live kernels and kernel crash dumps on
+many native BSD configurations. This is implemented as a special `kvm'
+debugging target. For debugging a live system, load the currently
+running kernel into GDB and connect to the `kvm' target:
+
+ (gdb) target kvm
+
+ For debugging crash dumps, provide the file name of the crash dump
+as an argument:
+
+ (gdb) target kvm /var/crash/bsd.0
+
+ Once connected to the `kvm' target, the following commands are
+available:
+
+`kvm pcb'
+ Set current context from the "Process Control Block" (PCB) address.
+
+`kvm proc'
+ Set current context from proc address. This command isn't
+ available on modern FreeBSD systems.
+
+
+File: gdb.info, Node: SVR4 Process Information, Next: DJGPP Native, Prev: BSD libkvm Interface, Up: Native
+
+21.1.3 SVR4 Process Information
+-------------------------------
+
+Many versions of SVR4 and compatible systems provide a facility called
+`/proc' that can be used to examine the image of a running process
+using file-system subroutines. If GDB is configured for an operating
+system with this facility, the command `info proc' is available to
+report information about the process running your program, or about any
+process running on your system. `info proc' works only on SVR4 systems
+that include the `procfs' code. This includes, as of this writing,
+GNU/Linux, OSF/1 (Digital Unix), Solaris, Irix, and Unixware, but not
+HP-UX, for example.
+
+`info proc'
+`info proc PROCESS-ID'
+ Summarize available information about any running process. If a
+ process ID is specified by PROCESS-ID, display information about
+ that process; otherwise display information about the program being
+ debugged. The summary includes the debugged process ID, the
+ command line used to invoke it, its current working directory, and
+ its executable file's absolute file name.
+
+ On some systems, PROCESS-ID can be of the form `[PID]/TID' which
+ specifies a certain thread ID within a process. If the optional
+ PID part is missing, it means a thread from the process being
+ debugged (the leading `/' still needs to be present, or else GDB
+ will interpret the number as a process ID rather than a thread ID).
+
+`info proc mappings'
+ Report the memory address space ranges accessible in the program,
+ with information on whether the process has read, write, or
+ execute access rights to each range. On GNU/Linux systems, each
+ memory range includes the object file which is mapped to that
+ range, instead of the memory access rights to that range.
+
+`info proc stat'
+`info proc status'
+ These subcommands are specific to GNU/Linux systems. They show
+ the process-related information, including the user ID and group
+ ID; how many threads are there in the process; its virtual memory
+ usage; the signals that are pending, blocked, and ignored; its
+ TTY; its consumption of system and user time; its stack size; its
+ `nice' value; etc. For more information, see the `proc' man page
+ (type `man 5 proc' from your shell prompt).
+
+`info proc all'
+ Show all the information about the process described under all of
+ the above `info proc' subcommands.
+
+`set procfs-trace'
+ This command enables and disables tracing of `procfs' API calls.
+
+`show procfs-trace'
+ Show the current state of `procfs' API call tracing.
+
+`set procfs-file FILE'
+ Tell GDB to write `procfs' API trace to the named FILE. GDB
+ appends the trace info to the previous contents of the file. The
+ default is to display the trace on the standard output.
+
+`show procfs-file'
+ Show the file to which `procfs' API trace is written.
+
+`proc-trace-entry'
+`proc-trace-exit'
+`proc-untrace-entry'
+`proc-untrace-exit'
+ These commands enable and disable tracing of entries into and exits
+ from the `syscall' interface.
+
+`info pidlist'
+ For QNX Neutrino only, this command displays the list of all the
+ processes and all the threads within each process.
+
+`info meminfo'
+ For QNX Neutrino only, this command displays the list of all
+ mapinfos.
+
+
+File: gdb.info, Node: DJGPP Native, Next: Cygwin Native, Prev: SVR4 Process Information, Up: Native
+
+21.1.4 Features for Debugging DJGPP Programs
+--------------------------------------------
+
+DJGPP is a port of the GNU development tools to MS-DOS and MS-Windows.
+DJGPP programs are 32-bit protected-mode programs that use the "DPMI"
+(DOS Protected-Mode Interface) API to run on top of real-mode DOS
+systems and their emulations.
+
+ GDB supports native debugging of DJGPP programs, and defines a few
+commands specific to the DJGPP port. This subsection describes those
+commands.
+
+`info dos'
+ This is a prefix of DJGPP-specific commands which print
+ information about the target system and important OS structures.
+
+`info dos sysinfo'
+ This command displays assorted information about the underlying
+ platform: the CPU type and features, the OS version and flavor, the
+ DPMI version, and the available conventional and DPMI memory.
+
+`info dos gdt'
+`info dos ldt'
+`info dos idt'
+ These 3 commands display entries from, respectively, Global, Local,
+ and Interrupt Descriptor Tables (GDT, LDT, and IDT). The
+ descriptor tables are data structures which store a descriptor for
+ each segment that is currently in use. The segment's selector is
+ an index into a descriptor table; the table entry for that index
+ holds the descriptor's base address and limit, and its attributes
+ and access rights.
+
+ A typical DJGPP program uses 3 segments: a code segment, a data
+ segment (used for both data and the stack), and a DOS segment
+ (which allows access to DOS/BIOS data structures and absolute
+ addresses in conventional memory). However, the DPMI host will
+ usually define additional segments in order to support the DPMI
+ environment.
+
+ These commands allow to display entries from the descriptor tables.
+ Without an argument, all entries from the specified table are
+ displayed. An argument, which should be an integer expression,
+ means display a single entry whose index is given by the argument.
+ For example, here's a convenient way to display information about
+ the debugged program's data segment:
+
+ `(gdb) info dos ldt $ds'
+ `0x13f: base=0x11970000 limit=0x0009ffff 32-Bit Data (Read/Write, Exp-up)'
+
+
+ This comes in handy when you want to see whether a pointer is
+ outside the data segment's limit (i.e. "garbled").
+
+`info dos pde'
+`info dos pte'
+ These two commands display entries from, respectively, the Page
+ Directory and the Page Tables. Page Directories and Page Tables
+ are data structures which control how virtual memory addresses are
+ mapped into physical addresses. A Page Table includes an entry
+ for every page of memory that is mapped into the program's address
+ space; there may be several Page Tables, each one holding up to
+ 4096 entries. A Page Directory has up to 4096 entries, one each
+ for every Page Table that is currently in use.
+
+ Without an argument, `info dos pde' displays the entire Page
+ Directory, and `info dos pte' displays all the entries in all of
+ the Page Tables. An argument, an integer expression, given to the
+ `info dos pde' command means display only that entry from the Page
+ Directory table. An argument given to the `info dos pte' command
+ means display entries from a single Page Table, the one pointed to
+ by the specified entry in the Page Directory.
+
+ These commands are useful when your program uses "DMA" (Direct
+ Memory Access), which needs physical addresses to program the DMA
+ controller.
+
+ These commands are supported only with some DPMI servers.
+
+`info dos address-pte ADDR'
+ This command displays the Page Table entry for a specified linear
+ address. The argument ADDR is a linear address which should
+ already have the appropriate segment's base address added to it,
+ because this command accepts addresses which may belong to _any_
+ segment. For example, here's how to display the Page Table entry
+ for the page where a variable `i' is stored:
+
+ `(gdb) info dos address-pte __djgpp_base_address + (char *)&i'
+ `Page Table entry for address 0x11a00d30:'
+ `Base=0x02698000 Dirty Acc. Not-Cached Write-Back Usr Read-Write +0xd30'
+
+
+ This says that `i' is stored at offset `0xd30' from the page whose
+ physical base address is `0x02698000', and shows all the
+ attributes of that page.
+
+ Note that you must cast the addresses of variables to a `char *',
+ since otherwise the value of `__djgpp_base_address', the base
+ address of all variables and functions in a DJGPP program, will be
+ added using the rules of C pointer arithmetics: if `i' is declared
+ an `int', GDB will add 4 times the value of `__djgpp_base_address'
+ to the address of `i'.
+
+ Here's another example, it displays the Page Table entry for the
+ transfer buffer:
+
+ `(gdb) info dos address-pte *((unsigned *)&_go32_info_block + 3)'
+ `Page Table entry for address 0x29110:'
+ `Base=0x00029000 Dirty Acc. Not-Cached Write-Back Usr Read-Write +0x110'
+
+
+ (The `+ 3' offset is because the transfer buffer's address is the
+ 3rd member of the `_go32_info_block' structure.) The output
+ clearly shows that this DPMI server maps the addresses in
+ conventional memory 1:1, i.e. the physical (`0x00029000' +
+ `0x110') and linear (`0x29110') addresses are identical.
+
+ This command is supported only with some DPMI servers.
+
+ In addition to native debugging, the DJGPP port supports remote
+debugging via a serial data link. The following commands are specific
+to remote serial debugging in the DJGPP port of GDB.
+
+`set com1base ADDR'
+ This command sets the base I/O port address of the `COM1' serial
+ port.
+
+`set com1irq IRQ'
+ This command sets the "Interrupt Request" (`IRQ') line to use for
+ the `COM1' serial port.
+
+ There are similar commands `set com2base', `set com3irq', etc. for
+ setting the port address and the `IRQ' lines for the other 3 COM
+ ports.
+
+ The related commands `show com1base', `show com1irq' etc. display
+ the current settings of the base address and the `IRQ' lines used
+ by the COM ports.
+
+`info serial'
+ This command prints the status of the 4 DOS serial ports. For each
+ port, it prints whether it's active or not, its I/O base address
+ and IRQ number, whether it uses a 16550-style FIFO, its baudrate,
+ and the counts of various errors encountered so far.
+
+
+File: gdb.info, Node: Cygwin Native, Next: Hurd Native, Prev: DJGPP Native, Up: Native
+
+21.1.5 Features for Debugging MS Windows PE Executables
+-------------------------------------------------------
+
+GDB supports native debugging of MS Windows programs, including DLLs
+with and without symbolic debugging information.
+
+ MS-Windows programs that call `SetConsoleMode' to switch off the
+special meaning of the `Ctrl-C' keystroke cannot be interrupted by
+typing `C-c'. For this reason, GDB on MS-Windows supports `C-<BREAK>'
+as an alternative interrupt key sequence, which can be used to
+interrupt the debuggee even if it ignores `C-c'.
+
+ There are various additional Cygwin-specific commands, described in
+this section. Working with DLLs that have no debugging symbols is
+described in *Note Non-debug DLL Symbols::.
+
+`info w32'
+ This is a prefix of MS Windows-specific commands which print
+ information about the target system and important OS structures.
+
+`info w32 selector'
+ This command displays information returned by the Win32 API
+ `GetThreadSelectorEntry' function. It takes an optional argument
+ that is evaluated to a long value to give the information about
+ this given selector. Without argument, this command displays
+ information about the six segment registers.
+
+`info w32 thread-information-block'
+ This command displays thread specific information stored in the
+ Thread Information Block (readable on the X86 CPU family using
+ `$fs' selector for 32-bit programs and `$gs' for 64-bit programs).
+
+`info dll'
+ This is a Cygwin-specific alias of `info shared'.
+
+`dll-symbols'
+ This command loads symbols from a dll similarly to add-sym command
+ but without the need to specify a base address.
+
+`set cygwin-exceptions MODE'
+ If MODE is `on', GDB will break on exceptions that happen inside
+ the Cygwin DLL. If MODE is `off', GDB will delay recognition of
+ exceptions, and may ignore some exceptions which seem to be caused
+ by internal Cygwin DLL "bookkeeping". This option is meant
+ primarily for debugging the Cygwin DLL itself; the default value
+ is `off' to avoid annoying GDB users with false `SIGSEGV' signals.
+
+`show cygwin-exceptions'
+ Displays whether GDB will break on exceptions that happen inside
+ the Cygwin DLL itself.
+
+`set new-console MODE'
+ If MODE is `on' the debuggee will be started in a new console on
+ next start. If MODE is `off', the debuggee will be started in the
+ same console as the debugger.
+
+`show new-console'
+ Displays whether a new console is used when the debuggee is
+ started.
+
+`set new-group MODE'
+ This boolean value controls whether the debuggee should start a
+ new group or stay in the same group as the debugger. This affects
+ the way the Windows OS handles `Ctrl-C'.
+
+`show new-group'
+ Displays current value of new-group boolean.
+
+`set debugevents'
+ This boolean value adds debug output concerning kernel events
+ related to the debuggee seen by the debugger. This includes
+ events that signal thread and process creation and exit, DLL
+ loading and unloading, console interrupts, and debugging messages
+ produced by the Windows `OutputDebugString' API call.
+
+`set debugexec'
+ This boolean value adds debug output concerning execute events
+ (such as resume thread) seen by the debugger.
+
+`set debugexceptions'
+ This boolean value adds debug output concerning exceptions in the
+ debuggee seen by the debugger.
+
+`set debugmemory'
+ This boolean value adds debug output concerning debuggee memory
+ reads and writes by the debugger.
+
+`set shell'
+ This boolean values specifies whether the debuggee is called via a
+ shell or directly (default value is on).
+
+`show shell'
+ Displays if the debuggee will be started with a shell.
+
+
+* Menu:
+
+* Non-debug DLL Symbols:: Support for DLLs without debugging symbols
+
+
+File: gdb.info, Node: Non-debug DLL Symbols, Up: Cygwin Native
+
+21.1.5.1 Support for DLLs without Debugging Symbols
+...................................................
+
+Very often on windows, some of the DLLs that your program relies on do
+not include symbolic debugging information (for example,
+`kernel32.dll'). When GDB doesn't recognize any debugging symbols in a
+DLL, it relies on the minimal amount of symbolic information contained
+in the DLL's export table. This section describes working with such
+symbols, known internally to GDB as "minimal symbols".
+
+ Note that before the debugged program has started execution, no DLLs
+will have been loaded. The easiest way around this problem is simply to
+start the program -- either by setting a breakpoint or letting the
+program run once to completion. It is also possible to force GDB to
+load a particular DLL before starting the executable -- see the shared
+library information in *Note Files::, or the `dll-symbols' command in
+*Note Cygwin Native::. Currently, explicitly loading symbols from a
+DLL with no debugging information will cause the symbol names to be
+duplicated in GDB's lookup table, which may adversely affect symbol
+lookup performance.
+
+21.1.5.2 DLL Name Prefixes
+..........................
+
+In keeping with the naming conventions used by the Microsoft debugging
+tools, DLL export symbols are made available with a prefix based on the
+DLL name, for instance `KERNEL32!CreateFileA'. The plain name is also
+entered into the symbol table, so `CreateFileA' is often sufficient.
+In some cases there will be name clashes within a program (particularly
+if the executable itself includes full debugging symbols) necessitating
+the use of the fully qualified name when referring to the contents of
+the DLL. Use single-quotes around the name to avoid the exclamation
+mark ("!") being interpreted as a language operator.
+
+ Note that the internal name of the DLL may be all upper-case, even
+though the file name of the DLL is lower-case, or vice-versa. Since
+symbols within GDB are _case-sensitive_ this may cause some confusion.
+If in doubt, try the `info functions' and `info variables' commands or
+even `maint print msymbols' (*note Symbols::). Here's an example:
+
+ (gdb) info function CreateFileA
+ All functions matching regular expression "CreateFileA":
+
+ Non-debugging symbols:
+ 0x77e885f4 CreateFileA
+ 0x77e885f4 KERNEL32!CreateFileA
+
+ (gdb) info function !
+ All functions matching regular expression "!":
+
+ Non-debugging symbols:
+ 0x6100114c cygwin1!__assert
+ 0x61004034 cygwin1!_dll_crt0@0
+ 0x61004240 cygwin1!dll_crt0(per_process *)
+ [etc...]
+
+21.1.5.3 Working with Minimal Symbols
+.....................................
+
+Symbols extracted from a DLL's export table do not contain very much
+type information. All that GDB can do is guess whether a symbol refers
+to a function or variable depending on the linker section that contains
+the symbol. Also note that the actual contents of the memory contained
+in a DLL are not available unless the program is running. This means
+that you cannot examine the contents of a variable or disassemble a
+function within a DLL without a running program.
+
+ Variables are generally treated as pointers and dereferenced
+automatically. For this reason, it is often necessary to prefix a
+variable name with the address-of operator ("&") and provide explicit
+type information in the command. Here's an example of the type of
+problem:
+
+ (gdb) print 'cygwin1!__argv'
+ $1 = 268572168
+
+ (gdb) x 'cygwin1!__argv'
+ 0x10021610: "\230y\""
+
+ And two possible solutions:
+
+ (gdb) print ((char **)'cygwin1!__argv')[0]
+ $2 = 0x22fd98 "/cygdrive/c/mydirectory/myprogram"
+
+ (gdb) x/2x &'cygwin1!__argv'
+ 0x610c0aa8 <cygwin1!__argv>: 0x10021608 0x00000000
+ (gdb) x/x 0x10021608
+ 0x10021608: 0x0022fd98
+ (gdb) x/s 0x0022fd98
+ 0x22fd98: "/cygdrive/c/mydirectory/myprogram"
+
+ Setting a break point within a DLL is possible even before the
+program starts execution. However, under these circumstances, GDB can't
+examine the initial instructions of the function in order to skip the
+function's frame set-up code. You can work around this by using "*&" to
+set the breakpoint at a raw memory address:
+
+ (gdb) break *&'python22!PyOS_Readline'
+ Breakpoint 1 at 0x1e04eff0
+
+ The author of these extensions is not entirely convinced that
+setting a break point within a shared DLL like `kernel32.dll' is
+completely safe.
+
+
+File: gdb.info, Node: Hurd Native, Next: Neutrino, Prev: Cygwin Native, Up: Native
+
+21.1.6 Commands Specific to GNU Hurd Systems
+--------------------------------------------
+
+This subsection describes GDB commands specific to the GNU Hurd native
+debugging.
+
+`set signals'
+`set sigs'
+ This command toggles the state of inferior signal interception by
+ GDB. Mach exceptions, such as breakpoint traps, are not affected
+ by this command. `sigs' is a shorthand alias for `signals'.
+
+`show signals'
+`show sigs'
+ Show the current state of intercepting inferior's signals.
+
+`set signal-thread'
+`set sigthread'
+ This command tells GDB which thread is the `libc' signal thread.
+ That thread is run when a signal is delivered to a running
+ process. `set sigthread' is the shorthand alias of `set
+ signal-thread'.
+
+`show signal-thread'
+`show sigthread'
+ These two commands show which thread will run when the inferior is
+ delivered a signal.
+
+`set stopped'
+ This commands tells GDB that the inferior process is stopped, as
+ with the `SIGSTOP' signal. The stopped process can be continued
+ by delivering a signal to it.
+
+`show stopped'
+ This command shows whether GDB thinks the debuggee is stopped.
+
+`set exceptions'
+ Use this command to turn off trapping of exceptions in the
+ inferior. When exception trapping is off, neither breakpoints nor
+ single-stepping will work. To restore the default, set exception
+ trapping on.
+
+`show exceptions'
+ Show the current state of trapping exceptions in the inferior.
+
+`set task pause'
+ This command toggles task suspension when GDB has control.
+ Setting it to on takes effect immediately, and the task is
+ suspended whenever GDB gets control. Setting it to off will take
+ effect the next time the inferior is continued. If this option is
+ set to off, you can use `set thread default pause on' or `set
+ thread pause on' (see below) to pause individual threads.
+
+`show task pause'
+ Show the current state of task suspension.
+
+`set task detach-suspend-count'
+ This command sets the suspend count the task will be left with when
+ GDB detaches from it.
+
+`show task detach-suspend-count'
+ Show the suspend count the task will be left with when detaching.
+
+`set task exception-port'
+`set task excp'
+ This command sets the task exception port to which GDB will
+ forward exceptions. The argument should be the value of the "send
+ rights" of the task. `set task excp' is a shorthand alias.
+
+`set noninvasive'
+ This command switches GDB to a mode that is the least invasive as
+ far as interfering with the inferior is concerned. This is the
+ same as using `set task pause', `set exceptions', and `set
+ signals' to values opposite to the defaults.
+
+`info send-rights'
+`info receive-rights'
+`info port-rights'
+`info port-sets'
+`info dead-names'
+`info ports'
+`info psets'
+ These commands display information about, respectively, send
+ rights, receive rights, port rights, port sets, and dead names of
+ a task. There are also shorthand aliases: `info ports' for `info
+ port-rights' and `info psets' for `info port-sets'.
+
+`set thread pause'
+ This command toggles current thread suspension when GDB has
+ control. Setting it to on takes effect immediately, and the
+ current thread is suspended whenever GDB gets control. Setting it
+ to off will take effect the next time the inferior is continued.
+ Normally, this command has no effect, since when GDB has control,
+ the whole task is suspended. However, if you used `set task pause
+ off' (see above), this command comes in handy to suspend only the
+ current thread.
+
+`show thread pause'
+ This command shows the state of current thread suspension.
+
+`set thread run'
+ This command sets whether the current thread is allowed to run.
+
+`show thread run'
+ Show whether the current thread is allowed to run.
+
+`set thread detach-suspend-count'
+ This command sets the suspend count GDB will leave on a thread
+ when detaching. This number is relative to the suspend count
+ found by GDB when it notices the thread; use `set thread
+ takeover-suspend-count' to force it to an absolute value.
+
+`show thread detach-suspend-count'
+ Show the suspend count GDB will leave on the thread when detaching.
+
+`set thread exception-port'
+`set thread excp'
+ Set the thread exception port to which to forward exceptions. This
+ overrides the port set by `set task exception-port' (see above).
+ `set thread excp' is the shorthand alias.
+
+`set thread takeover-suspend-count'
+ Normally, GDB's thread suspend counts are relative to the value
+ GDB finds when it notices each thread. This command changes the
+ suspend counts to be absolute instead.
+
+`set thread default'
+`show thread default'
+ Each of the above `set thread' commands has a `set thread default'
+ counterpart (e.g., `set thread default pause', `set thread default
+ exception-port', etc.). The `thread default' variety of commands
+ sets the default thread properties for all threads; you can then
+ change the properties of individual threads with the non-default
+ commands.
+
+
+File: gdb.info, Node: Neutrino, Next: Darwin, Prev: Hurd Native, Up: Native
+
+21.1.7 QNX Neutrino
+-------------------
+
+GDB provides the following commands specific to the QNX Neutrino target:
+
+`set debug nto-debug'
+ When set to on, enables debugging messages specific to the QNX
+ Neutrino support.
+
+`show debug nto-debug'
+ Show the current state of QNX Neutrino messages.
+
+
+File: gdb.info, Node: Darwin, Prev: Neutrino, Up: Native
+
+21.1.8 Darwin
+-------------
+
+GDB provides the following commands specific to the Darwin target:
+
+`set debug darwin NUM'
+ When set to a non zero value, enables debugging messages specific
+ to the Darwin support. Higher values produce more verbose output.
+
+`show debug darwin'
+ Show the current state of Darwin messages.
+
+`set debug mach-o NUM'
+ When set to a non zero value, enables debugging messages while GDB
+ is reading Darwin object files. ("Mach-O" is the file format used
+ on Darwin for object and executable files.) Higher values produce
+ more verbose output. This is a command to diagnose problems
+ internal to GDB and should not be needed in normal usage.
+
+`show debug mach-o'
+ Show the current state of Mach-O file messages.
+
+`set mach-exceptions on'
+`set mach-exceptions off'
+ On Darwin, faults are first reported as a Mach exception and are
+ then mapped to a Posix signal. Use this command to turn on
+ trapping of Mach exceptions in the inferior. This might be
+ sometimes useful to better understand the cause of a fault. The
+ default is off.
+
+`show mach-exceptions'
+ Show the current state of exceptions trapping.
+
+
+File: gdb.info, Node: Embedded OS, Next: Embedded Processors, Prev: Native, Up: Configurations
+
+21.2 Embedded Operating Systems
+===============================
+
+This section describes configurations involving the debugging of
+embedded operating systems that are available for several different
+architectures.
+
+* Menu:
+
+* VxWorks:: Using GDB with VxWorks
+
+ GDB includes the ability to debug programs running on various
+real-time operating systems.
+
+
+File: gdb.info, Node: VxWorks, Up: Embedded OS
+
+21.2.1 Using GDB with VxWorks
+-----------------------------
+
+`target vxworks MACHINENAME'
+ A VxWorks system, attached via TCP/IP. The argument MACHINENAME
+ is the target system's machine name or IP address.
+
+
+ On VxWorks, `load' links FILENAME dynamically on the current target
+system as well as adding its symbols in GDB.
+
+ GDB enables developers to spawn and debug tasks running on networked
+VxWorks targets from a Unix host. Already-running tasks spawned from
+the VxWorks shell can also be debugged. GDB uses code that runs on
+both the Unix host and on the VxWorks target. The program `gdb' is
+installed and executed on the Unix host. (It may be installed with the
+name `vxgdb', to distinguish it from a GDB for debugging programs on
+the host itself.)
+
+`VxWorks-timeout ARGS'
+ All VxWorks-based targets now support the option `vxworks-timeout'.
+ This option is set by the user, and ARGS represents the number of
+ seconds GDB waits for responses to rpc's. You might use this if
+ your VxWorks target is a slow software simulator or is on the far
+ side of a thin network line.
+
+ The following information on connecting to VxWorks was current when
+this manual was produced; newer releases of VxWorks may use revised
+procedures.
+
+ To use GDB with VxWorks, you must rebuild your VxWorks kernel to
+include the remote debugging interface routines in the VxWorks library
+`rdb.a'. To do this, define `INCLUDE_RDB' in the VxWorks configuration
+file `configAll.h' and rebuild your VxWorks kernel. The resulting
+kernel contains `rdb.a', and spawns the source debugging task
+`tRdbTask' when VxWorks is booted. For more information on configuring
+and remaking VxWorks, see the manufacturer's manual.
+
+ Once you have included `rdb.a' in your VxWorks system image and set
+your Unix execution search path to find GDB, you are ready to run GDB.
+From your Unix host, run `gdb' (or `vxgdb', depending on your
+installation).
+
+ GDB comes up showing the prompt:
+
+ (vxgdb)
+
+* Menu:
+
+* VxWorks Connection:: Connecting to VxWorks
+* VxWorks Download:: VxWorks download
+* VxWorks Attach:: Running tasks
+
+
+File: gdb.info, Node: VxWorks Connection, Next: VxWorks Download, Up: VxWorks
+
+21.2.1.1 Connecting to VxWorks
+..............................
+
+The GDB command `target' lets you connect to a VxWorks target on the
+network. To connect to a target whose host name is "`tt'", type:
+
+ (vxgdb) target vxworks tt
+
+ GDB displays messages like these:
+
+ Attaching remote machine across net...
+ Connected to tt.
+
+ GDB then attempts to read the symbol tables of any object modules
+loaded into the VxWorks target since it was last booted. GDB locates
+these files by searching the directories listed in the command search
+path (*note Your Program's Environment: Environment.); if it fails to
+find an object file, it displays a message such as:
+
+ prog.o: No such file or directory.
+
+ When this happens, add the appropriate directory to the search path
+with the GDB command `path', and execute the `target' command again.
+
+
+File: gdb.info, Node: VxWorks Download, Next: VxWorks Attach, Prev: VxWorks Connection, Up: VxWorks
+
+21.2.1.2 VxWorks Download
+.........................
+
+If you have connected to the VxWorks target and you want to debug an
+object that has not yet been loaded, you can use the GDB `load' command
+to download a file from Unix to VxWorks incrementally. The object file
+given as an argument to the `load' command is actually opened twice:
+first by the VxWorks target in order to download the code, then by GDB
+in order to read the symbol table. This can lead to problems if the
+current working directories on the two systems differ. If both systems
+have NFS mounted the same filesystems, you can avoid these problems by
+using absolute paths. Otherwise, it is simplest to set the working
+directory on both systems to the directory in which the object file
+resides, and then to reference the file by its name, without any path.
+For instance, a program `prog.o' may reside in `VXPATH/vw/demo/rdb' in
+VxWorks and in `HOSTPATH/vw/demo/rdb' on the host. To load this
+program, type this on VxWorks:
+
+ -> cd "VXPATH/vw/demo/rdb"
+
+Then, in GDB, type:
+
+ (vxgdb) cd HOSTPATH/vw/demo/rdb
+ (vxgdb) load prog.o
+
+ GDB displays a response similar to this:
+
+ Reading symbol data from wherever/vw/demo/rdb/prog.o... done.
+
+ You can also use the `load' command to reload an object module after
+editing and recompiling the corresponding source file. Note that this
+makes GDB delete all currently-defined breakpoints, auto-displays, and
+convenience variables, and to clear the value history. (This is
+necessary in order to preserve the integrity of debugger's data
+structures that reference the target system's symbol table.)
+
+
+File: gdb.info, Node: VxWorks Attach, Prev: VxWorks Download, Up: VxWorks
+
+21.2.1.3 Running Tasks
+......................
+
+You can also attach to an existing task using the `attach' command as
+follows:
+
+ (vxgdb) attach TASK
+
+where TASK is the VxWorks hexadecimal task ID. The task can be running
+or suspended when you attach to it. Running tasks are suspended at the
+time of attachment.
+
+
+File: gdb.info, Node: Embedded Processors, Next: Architectures, Prev: Embedded OS, Up: Configurations
+
+21.3 Embedded Processors
+========================
+
+This section goes into details specific to particular embedded
+configurations.
+
+ Whenever a specific embedded processor has a simulator, GDB allows
+to send an arbitrary command to the simulator.
+
+`sim COMMAND'
+ Send an arbitrary COMMAND string to the simulator. Consult the
+ documentation for the specific simulator in use for information
+ about acceptable commands.
+
+* Menu:
+
+* ARM:: ARM RDI
+* M32R/D:: Renesas M32R/D
+* M68K:: Motorola M68K
+* MicroBlaze:: Xilinx MicroBlaze
+* MIPS Embedded:: MIPS Embedded
+* OpenRISC 1000:: OpenRisc 1000
+* PA:: HP PA Embedded
+* PowerPC Embedded:: PowerPC Embedded
+* Sparclet:: Tsqware Sparclet
+* Sparclite:: Fujitsu Sparclite
+* Z8000:: Zilog Z8000
+* AVR:: Atmel AVR
+* CRIS:: CRIS
+* Super-H:: Renesas Super-H
+
+
+File: gdb.info, Node: ARM, Next: M32R/D, Up: Embedded Processors
+
+21.3.1 ARM
+----------
+
+`target rdi DEV'
+ ARM Angel monitor, via RDI library interface to ADP protocol. You
+ may use this target to communicate with both boards running the
+ Angel monitor, or with the EmbeddedICE JTAG debug device.
+
+`target rdp DEV'
+ ARM Demon monitor.
+
+
+ GDB provides the following ARM-specific commands:
+
+`set arm disassembler'
+ This commands selects from a list of disassembly styles. The
+ `"std"' style is the standard style.
+
+`show arm disassembler'
+ Show the current disassembly style.
+
+`set arm apcs32'
+ This command toggles ARM operation mode between 32-bit and 26-bit.
+
+`show arm apcs32'
+ Display the current usage of the ARM 32-bit mode.
+
+`set arm fpu FPUTYPE'
+ This command sets the ARM floating-point unit (FPU) type. The
+ argument FPUTYPE can be one of these:
+
+ `auto'
+ Determine the FPU type by querying the OS ABI.
+
+ `softfpa'
+ Software FPU, with mixed-endian doubles on little-endian ARM
+ processors.
+
+ `fpa'
+ GCC-compiled FPA co-processor.
+
+ `softvfp'
+ Software FPU with pure-endian doubles.
+
+ `vfp'
+ VFP co-processor.
+
+`show arm fpu'
+ Show the current type of the FPU.
+
+`set arm abi'
+ This command forces GDB to use the specified ABI.
+
+`show arm abi'
+ Show the currently used ABI.
+
+`set arm fallback-mode (arm|thumb|auto)'
+ GDB uses the symbol table, when available, to determine whether
+ instructions are ARM or Thumb. This command controls GDB's
+ default behavior when the symbol table is not available. The
+ default is `auto', which causes GDB to use the current execution
+ mode (from the `T' bit in the `CPSR' register).
+
+`show arm fallback-mode'
+ Show the current fallback instruction mode.
+
+`set arm force-mode (arm|thumb|auto)'
+ This command overrides use of the symbol table to determine whether
+ instructions are ARM or Thumb. The default is `auto', which
+ causes GDB to use the symbol table and then the setting of `set
+ arm fallback-mode'.
+
+`show arm force-mode'
+ Show the current forced instruction mode.
+
+`set debug arm'
+ Toggle whether to display ARM-specific debugging messages from the
+ ARM target support subsystem.
+
+`show debug arm'
+ Show whether ARM-specific debugging messages are enabled.
+
+ The following commands are available when an ARM target is debugged
+using the RDI interface:
+
+`rdilogfile [FILE]'
+ Set the filename for the ADP (Angel Debugger Protocol) packet log.
+ With an argument, sets the log file to the specified FILE. With
+ no argument, show the current log file name. The default log file
+ is `rdi.log'.
+
+`rdilogenable [ARG]'
+ Control logging of ADP packets. With an argument of 1 or `"yes"'
+ enables logging, with an argument 0 or `"no"' disables it. With
+ no arguments displays the current setting. When logging is
+ enabled, ADP packets exchanged between GDB and the RDI target
+ device are logged to a file.
+
+`set rdiromatzero'
+ Tell GDB whether the target has ROM at address 0. If on, vector
+ catching is disabled, so that zero address can be used. If off
+ (the default), vector catching is enabled. For this command to
+ take effect, it needs to be invoked prior to the `target rdi'
+ command.
+
+`show rdiromatzero'
+ Show the current setting of ROM at zero address.
+
+`set rdiheartbeat'
+ Enable or disable RDI heartbeat packets. It is not recommended to
+ turn on this option, since it confuses ARM and EPI JTAG interface,
+ as well as the Angel monitor.
+
+`show rdiheartbeat'
+ Show the setting of RDI heartbeat packets.
+
+`target sim [SIMARGS] ...'
+ The GDB ARM simulator accepts the following optional arguments.
+
+ `--swi-support=TYPE'
+ Tell the simulator which SWI interfaces to support. TYPE may
+ be a comma separated list of the following values. The
+ default value is `all'.
+
+ `none'
+
+ `demon'
+
+ `angel'
+
+ `redboot'
+
+ `all'
+
+
+File: gdb.info, Node: M32R/D, Next: M68K, Prev: ARM, Up: Embedded Processors
+
+21.3.2 Renesas M32R/D and M32R/SDI
+----------------------------------
+
+`target m32r DEV'
+ Renesas M32R/D ROM monitor.
+
+`target m32rsdi DEV'
+ Renesas M32R SDI server, connected via parallel port to the board.
+
+ The following GDB commands are specific to the M32R monitor:
+
+`set download-path PATH'
+ Set the default path for finding downloadable SREC files.
+
+`show download-path'
+ Show the default path for downloadable SREC files.
+
+`set board-address ADDR'
+ Set the IP address for the M32R-EVA target board.
+
+`show board-address'
+ Show the current IP address of the target board.
+
+`set server-address ADDR'
+ Set the IP address for the download server, which is the GDB's
+ host machine.
+
+`show server-address'
+ Display the IP address of the download server.
+
+`upload [FILE]'
+ Upload the specified SREC FILE via the monitor's Ethernet upload
+ capability. If no FILE argument is given, the current executable
+ file is uploaded.
+
+`tload [FILE]'
+ Test the `upload' command.
+
+ The following commands are available for M32R/SDI:
+
+`sdireset'
+ This command resets the SDI connection.
+
+`sdistatus'
+ This command shows the SDI connection status.
+
+`debug_chaos'
+ Instructs the remote that M32R/Chaos debugging is to be used.
+
+`use_debug_dma'
+ Instructs the remote to use the DEBUG_DMA method of accessing
+ memory.
+
+`use_mon_code'
+ Instructs the remote to use the MON_CODE method of accessing
+ memory.
+
+`use_ib_break'
+ Instructs the remote to set breakpoints by IB break.
+
+`use_dbt_break'
+ Instructs the remote to set breakpoints by DBT.
+
+
+File: gdb.info, Node: M68K, Next: MicroBlaze, Prev: M32R/D, Up: Embedded Processors
+
+21.3.3 M68k
+-----------
+
+The Motorola m68k configuration includes ColdFire support, and a target
+command for the following ROM monitor.
+
+`target dbug DEV'
+ dBUG ROM monitor for Motorola ColdFire.
+
+
+
+File: gdb.info, Node: MicroBlaze, Next: MIPS Embedded, Prev: M68K, Up: Embedded Processors
+
+21.3.4 MicroBlaze
+-----------------
+
+The MicroBlaze is a soft-core processor supported on various Xilinx
+FPGAs, such as Spartan or Virtex series. Boards with these processors
+usually have JTAG ports which connect to a host system running the
+Xilinx Embedded Development Kit (EDK) or Software Development Kit (SDK).
+This host system is used to download the configuration bitstream to the
+target FPGA. The Xilinx Microprocessor Debugger (XMD) program
+communicates with the target board using the JTAG interface and
+presents a `gdbserver' interface to the board. By default `xmd' uses
+port `1234'. (While it is possible to change this default port, it
+requires the use of undocumented `xmd' commands. Contact Xilinx
+support if you need to do this.)
+
+ Use these GDB commands to connect to the MicroBlaze target processor.
+
+`target remote :1234'
+ Use this command to connect to the target if you are running GDB
+ on the same system as `xmd'.
+
+`target remote XMD-HOST:1234'
+ Use this command to connect to the target if it is connected to
+ `xmd' running on a different system named XMD-HOST.
+
+`load'
+ Use this command to download a program to the MicroBlaze target.
+
+`set debug microblaze N'
+ Enable MicroBlaze-specific debugging messages if non-zero.
+
+`show debug microblaze N'
+ Show MicroBlaze-specific debugging level.
+
+
+File: gdb.info, Node: MIPS Embedded, Next: OpenRISC 1000, Prev: MicroBlaze, Up: Embedded Processors
+
+21.3.5 MIPS Embedded
+--------------------
+
+GDB can use the MIPS remote debugging protocol to talk to a MIPS board
+attached to a serial line. This is available when you configure GDB
+with `--target=mips-idt-ecoff'.
+
+ Use these GDB commands to specify the connection to your target
+board:
+
+`target mips PORT'
+ To run a program on the board, start up `gdb' with the name of
+ your program as the argument. To connect to the board, use the
+ command `target mips PORT', where PORT is the name of the serial
+ port connected to the board. If the program has not already been
+ downloaded to the board, you may use the `load' command to
+ download it. You can then use all the usual GDB commands.
+
+ For example, this sequence connects to the target board through a
+ serial port, and loads and runs a program called PROG through the
+ debugger:
+
+ host$ gdb PROG
+ GDB is free software and ...
+ (gdb) target mips /dev/ttyb
+ (gdb) load PROG
+ (gdb) run
+
+`target mips HOSTNAME:PORTNUMBER'
+ On some GDB host configurations, you can specify a TCP connection
+ (for instance, to a serial line managed by a terminal
+ concentrator) instead of a serial port, using the syntax
+ `HOSTNAME:PORTNUMBER'.
+
+`target pmon PORT'
+ PMON ROM monitor.
+
+`target ddb PORT'
+ NEC's DDB variant of PMON for Vr4300.
+
+`target lsi PORT'
+ LSI variant of PMON.
+
+`target r3900 DEV'
+ Densan DVE-R3900 ROM monitor for Toshiba R3900 Mips.
+
+`target array DEV'
+ Array Tech LSI33K RAID controller board.
+
+
+GDB also supports these special commands for MIPS targets:
+
+`set mipsfpu double'
+`set mipsfpu single'
+`set mipsfpu none'
+`set mipsfpu auto'
+`show mipsfpu'
+ If your target board does not support the MIPS floating point
+ coprocessor, you should use the command `set mipsfpu none' (if you
+ need this, you may wish to put the command in your GDB init file).
+ This tells GDB how to find the return value of functions which
+ return floating point values. It also allows GDB to avoid saving
+ the floating point registers when calling functions on the board.
+ If you are using a floating point coprocessor with only single
+ precision floating point support, as on the R4650 processor, use
+ the command `set mipsfpu single'. The default double precision
+ floating point coprocessor may be selected using `set mipsfpu
+ double'.
+
+ In previous versions the only choices were double precision or no
+ floating point, so `set mipsfpu on' will select double precision
+ and `set mipsfpu off' will select no floating point.
+
+ As usual, you can inquire about the `mipsfpu' variable with `show
+ mipsfpu'.
+
+`set timeout SECONDS'
+`set retransmit-timeout SECONDS'
+`show timeout'
+`show retransmit-timeout'
+ You can control the timeout used while waiting for a packet, in
+ the MIPS remote protocol, with the `set timeout SECONDS' command.
+ The default is 5 seconds. Similarly, you can control the timeout
+ used while waiting for an acknowledgment of a packet with the `set
+ retransmit-timeout SECONDS' command. The default is 3 seconds.
+ You can inspect both values with `show timeout' and `show
+ retransmit-timeout'. (These commands are _only_ available when
+ GDB is configured for `--target=mips-idt-ecoff'.)
+
+ The timeout set by `set timeout' does not apply when GDB is
+ waiting for your program to stop. In that case, GDB waits forever
+ because it has no way of knowing how long the program is going to
+ run before stopping.
+
+`set syn-garbage-limit NUM'
+ Limit the maximum number of characters GDB should ignore when it
+ tries to synchronize with the remote target. The default is 10
+ characters. Setting the limit to -1 means there's no limit.
+
+`show syn-garbage-limit'
+ Show the current limit on the number of characters to ignore when
+ trying to synchronize with the remote system.
+
+`set monitor-prompt PROMPT'
+ Tell GDB to expect the specified PROMPT string from the remote
+ monitor. The default depends on the target:
+ pmon target
+ `PMON'
+
+ ddb target
+ `NEC010'
+
+ lsi target
+ `PMON>'
+
+`show monitor-prompt'
+ Show the current strings GDB expects as the prompt from the remote
+ monitor.
+
+`set monitor-warnings'
+ Enable or disable monitor warnings about hardware breakpoints.
+ This has effect only for the `lsi' target. When on, GDB will
+ display warning messages whose codes are returned by the `lsi'
+ PMON monitor for breakpoint commands.
+
+`show monitor-warnings'
+ Show the current setting of printing monitor warnings.
+
+`pmon COMMAND'
+ This command allows sending an arbitrary COMMAND string to the
+ monitor. The monitor must be in debug mode for this to work.
+
+
+File: gdb.info, Node: OpenRISC 1000, Next: PA, Prev: MIPS Embedded, Up: Embedded Processors
+
+21.3.6 OpenRISC 1000
+--------------------
+
+See OR1k Architecture document (`www.opencores.org') for more
+information about platform and commands.
+
+`target jtag jtag://HOST:PORT'
+ Connects to remote JTAG server. JTAG remote server can be either
+ an or1ksim or JTAG server, connected via parallel port to the
+ board.
+
+ Example: `target jtag jtag://localhost:9999'
+
+`or1ksim COMMAND'
+ If connected to `or1ksim' OpenRISC 1000 Architectural Simulator,
+ proprietary commands can be executed.
+
+`info or1k spr'
+ Displays spr groups.
+
+`info or1k spr GROUP'
+`info or1k spr GROUPNO'
+ Displays register names in selected group.
+
+`info or1k spr GROUP REGISTER'
+`info or1k spr REGISTER'
+`info or1k spr GROUPNO REGISTERNO'
+`info or1k spr REGISTERNO'
+ Shows information about specified spr register.
+
+`spr GROUP REGISTER VALUE'
+`spr REGISTER VALUE'
+`spr GROUPNO REGISTERNO VALUE'
+`spr REGISTERNO VALUE'
+ Writes VALUE to specified spr register.
+
+ Some implementations of OpenRISC 1000 Architecture also have
+hardware trace. It is very similar to GDB trace, except it does not
+interfere with normal program execution and is thus much faster.
+Hardware breakpoints/watchpoint triggers can be set using:
+`$LEA/$LDATA'
+ Load effective address/data
+
+`$SEA/$SDATA'
+ Store effective address/data
+
+`$AEA/$ADATA'
+ Access effective address ($SEA or $LEA) or data ($SDATA/$LDATA)
+
+`$FETCH'
+ Fetch data
+
+ When triggered, it can capture low level data, like: `PC', `LSEA',
+`LDATA', `SDATA', `READSPR', `WRITESPR', `INSTR'.
+
+ `htrace' commands:
+`hwatch CONDITIONAL'
+ Set hardware watchpoint on combination of Load/Store Effective
+ Address(es) or Data. For example:
+
+ `hwatch ($LEA == my_var) && ($LDATA < 50) || ($SEA == my_var) &&
+ ($SDATA >= 50)'
+
+ `hwatch ($LEA == my_var) && ($LDATA < 50) || ($SEA == my_var) &&
+ ($SDATA >= 50)'
+
+`htrace info'
+ Display information about current HW trace configuration.
+
+`htrace trigger CONDITIONAL'
+ Set starting criteria for HW trace.
+
+`htrace qualifier CONDITIONAL'
+ Set acquisition qualifier for HW trace.
+
+`htrace stop CONDITIONAL'
+ Set HW trace stopping criteria.
+
+`htrace record [DATA]*'
+ Selects the data to be recorded, when qualifier is met and HW
+ trace was triggered.
+
+`htrace enable'
+`htrace disable'
+ Enables/disables the HW trace.
+
+`htrace rewind [FILENAME]'
+ Clears currently recorded trace data.
+
+ If filename is specified, new trace file is made and any newly
+ collected data will be written there.
+
+`htrace print [START [LEN]]'
+ Prints trace buffer, using current record configuration.
+
+`htrace mode continuous'
+ Set continuous trace mode.
+
+`htrace mode suspend'
+ Set suspend trace mode.
+
+
+
+File: gdb.info, Node: PowerPC Embedded, Next: Sparclet, Prev: PA, Up: Embedded Processors
+
+21.3.7 PowerPC Embedded
+-----------------------
+
+GDB supports using the DVC (Data Value Compare) register to implement
+in hardware simple hardware watchpoint conditions of the form:
+
+ (gdb) watch ADDRESS|VARIABLE \
+ if ADDRESS|VARIABLE == CONSTANT EXPRESSION
+
+ The DVC register will be automatically used when GDB detects such
+pattern in a condition expression, and the created watchpoint uses one
+debug register (either the `exact-watchpoints' option is on and the
+variable is scalar, or the variable has a length of one byte). This
+feature is available in native GDB running on a Linux kernel version
+2.6.34 or newer.
+
+ When running on PowerPC embedded processors, GDB automatically uses
+ranged hardware watchpoints, unless the `exact-watchpoints' option is
+on, in which case watchpoints using only one debug register are created
+when watching variables of scalar types.
+
+ You can create an artificial array to watch an arbitrary memory
+region using one of the following commands (*note Expressions::):
+
+ (gdb) watch *((char *) ADDRESS)@LENGTH
+ (gdb) watch {char[LENGTH]} ADDRESS
+
+ PowerPC embedded processors support masked watchpoints. See the
+discussion about the `mask' argument in *Note Set Watchpoints::.
+
+ PowerPC embedded processors support hardware accelerated "ranged
+breakpoints". A ranged breakpoint stops execution of the inferior
+whenever it executes an instruction at any address within the range it
+specifies. To set a ranged breakpoint in GDB, use the `break-range'
+command.
+
+ GDB provides the following PowerPC-specific commands:
+
+`break-range START-LOCATION, END-LOCATION'
+ Set a breakpoint for an address range. START-LOCATION and
+ END-LOCATION can specify a function name, a line number, an offset
+ of lines from the current line or from the start location, or an
+ address of an instruction (see *Note Specify Location::, for a
+ list of all the possible ways to specify a LOCATION.) The
+ breakpoint will stop execution of the inferior whenever it
+ executes an instruction at any address within the specified range,
+ (including START-LOCATION and END-LOCATION.)
+
+`set powerpc soft-float'
+`show powerpc soft-float'
+ Force GDB to use (or not use) a software floating point calling
+ convention. By default, GDB selects the calling convention based
+ on the selected architecture and the provided executable file.
+
+`set powerpc vector-abi'
+`show powerpc vector-abi'
+ Force GDB to use the specified calling convention for vector
+ arguments and return values. The valid options are `auto';
+ `generic', to avoid vector registers even if they are present;
+ `altivec', to use AltiVec registers; and `spe' to use SPE
+ registers. By default, GDB selects the calling convention based
+ on the selected architecture and the provided executable file.
+
+`set powerpc exact-watchpoints'
+`show powerpc exact-watchpoints'
+ Allow GDB to use only one debug register when watching a variable
+ of scalar type, thus assuming that the variable is accessed
+ through the address of its first byte.
+
+`target dink32 DEV'
+ DINK32 ROM monitor.
+
+`target ppcbug DEV'
+
+`target ppcbug1 DEV'
+ PPCBUG ROM monitor for PowerPC.
+
+`target sds DEV'
+ SDS monitor, running on a PowerPC board (such as Motorola's ADS).
+
+ The following commands specific to the SDS protocol are supported by
+GDB:
+
+`set sdstimeout NSEC'
+ Set the timeout for SDS protocol reads to be NSEC seconds. The
+ default is 2 seconds.
+
+`show sdstimeout'
+ Show the current value of the SDS timeout.
+
+`sds COMMAND'
+ Send the specified COMMAND string to the SDS monitor.
+
+
+File: gdb.info, Node: PA, Next: PowerPC Embedded, Prev: OpenRISC 1000, Up: Embedded Processors
+
+21.3.8 HP PA Embedded
+---------------------
+
+`target op50n DEV'
+ OP50N monitor, running on an OKI HPPA board.
+
+`target w89k DEV'
+ W89K monitor, running on a Winbond HPPA board.
+
+
+
+File: gdb.info, Node: Sparclet, Next: Sparclite, Prev: PowerPC Embedded, Up: Embedded Processors
+
+21.3.9 Tsqware Sparclet
+-----------------------
+
+GDB enables developers to debug tasks running on Sparclet targets from
+a Unix host. GDB uses code that runs on both the Unix host and on the
+Sparclet target. The program `gdb' is installed and executed on the
+Unix host.
+
+`remotetimeout ARGS'
+ GDB supports the option `remotetimeout'. This option is set by
+ the user, and ARGS represents the number of seconds GDB waits for
+ responses.
+
+ When compiling for debugging, include the options `-g' to get debug
+information and `-Ttext' to relocate the program to where you wish to
+load it on the target. You may also want to add the options `-n' or
+`-N' in order to reduce the size of the sections. Example:
+
+ sparclet-aout-gcc prog.c -Ttext 0x12010000 -g -o prog -N
+
+ You can use `objdump' to verify that the addresses are what you
+intended:
+
+ sparclet-aout-objdump --headers --syms prog
+
+ Once you have set your Unix execution search path to find GDB, you
+are ready to run GDB. From your Unix host, run `gdb' (or
+`sparclet-aout-gdb', depending on your installation).
+
+ GDB comes up showing the prompt:
+
+ (gdbslet)
+
+* Menu:
+
+* Sparclet File:: Setting the file to debug
+* Sparclet Connection:: Connecting to Sparclet
+* Sparclet Download:: Sparclet download
+* Sparclet Execution:: Running and debugging
+
+
+File: gdb.info, Node: Sparclet File, Next: Sparclet Connection, Up: Sparclet
+
+21.3.9.1 Setting File to Debug
+..............................
+
+The GDB command `file' lets you choose with program to debug.
+
+ (gdbslet) file prog
+
+ GDB then attempts to read the symbol table of `prog'. GDB locates
+the file by searching the directories listed in the command search path.
+If the file was compiled with debug information (option `-g'), source
+files will be searched as well. GDB locates the source files by
+searching the directories listed in the directory search path (*note
+Your Program's Environment: Environment.). If it fails to find a file,
+it displays a message such as:
+
+ prog: No such file or directory.
+
+ When this happens, add the appropriate directories to the search
+paths with the GDB commands `path' and `dir', and execute the `target'
+command again.
+
+
+File: gdb.info, Node: Sparclet Connection, Next: Sparclet Download, Prev: Sparclet File, Up: Sparclet
+
+21.3.9.2 Connecting to Sparclet
+...............................
+
+The GDB command `target' lets you connect to a Sparclet target. To
+connect to a target on serial port "`ttya'", type:
+
+ (gdbslet) target sparclet /dev/ttya
+ Remote target sparclet connected to /dev/ttya
+ main () at ../prog.c:3
+
+ GDB displays messages like these:
+
+ Connected to ttya.
+
+
+File: gdb.info, Node: Sparclet Download, Next: Sparclet Execution, Prev: Sparclet Connection, Up: Sparclet
+
+21.3.9.3 Sparclet Download
+..........................
+
+Once connected to the Sparclet target, you can use the GDB `load'
+command to download the file from the host to the target. The file
+name and load offset should be given as arguments to the `load' command.
+Since the file format is aout, the program must be loaded to the
+starting address. You can use `objdump' to find out what this value
+is. The load offset is an offset which is added to the VMA (virtual
+memory address) of each of the file's sections. For instance, if the
+program `prog' was linked to text address 0x1201000, with data at
+0x12010160 and bss at 0x12010170, in GDB, type:
+
+ (gdbslet) load prog 0x12010000
+ Loading section .text, size 0xdb0 vma 0x12010000
+
+ If the code is loaded at a different address then what the program
+was linked to, you may need to use the `section' and `add-symbol-file'
+commands to tell GDB where to map the symbol table.
+
+
+File: gdb.info, Node: Sparclet Execution, Prev: Sparclet Download, Up: Sparclet
+
+21.3.9.4 Running and Debugging
+..............................
+
+You can now begin debugging the task using GDB's execution control
+commands, `b', `step', `run', etc. See the GDB manual for the list of
+commands.
+
+ (gdbslet) b main
+ Breakpoint 1 at 0x12010000: file prog.c, line 3.
+ (gdbslet) run
+ Starting program: prog
+ Breakpoint 1, main (argc=1, argv=0xeffff21c) at prog.c:3
+ 3 char *symarg = 0;
+ (gdbslet) step
+ 4 char *execarg = "hello!";
+ (gdbslet)
+
+
+File: gdb.info, Node: Sparclite, Next: Z8000, Prev: Sparclet, Up: Embedded Processors
+
+21.3.10 Fujitsu Sparclite
+-------------------------
+
+`target sparclite DEV'
+ Fujitsu sparclite boards, used only for the purpose of loading.
+ You must use an additional command to debug the program. For
+ example: target remote DEV using GDB standard remote protocol.
+
+
+
+File: gdb.info, Node: Z8000, Next: AVR, Prev: Sparclite, Up: Embedded Processors
+
+21.3.11 Zilog Z8000
+-------------------
+
+When configured for debugging Zilog Z8000 targets, GDB includes a Z8000
+simulator.
+
+ For the Z8000 family, `target sim' simulates either the Z8002 (the
+unsegmented variant of the Z8000 architecture) or the Z8001 (the
+segmented variant). The simulator recognizes which architecture is
+appropriate by inspecting the object code.
+
+`target sim ARGS'
+ Debug programs on a simulated CPU. If the simulator supports setup
+ options, specify them via ARGS.
+
+After specifying this target, you can debug programs for the simulated
+CPU in the same style as programs for your host computer; use the
+`file' command to load a new program image, the `run' command to run
+your program, and so on.
+
+ As well as making available all the usual machine registers (*note
+Registers: Registers.), the Z8000 simulator provides three additional
+items of information as specially named registers:
+
+`cycles'
+ Counts clock-ticks in the simulator.
+
+`insts'
+ Counts instructions run in the simulator.
+
+`time'
+ Execution time in 60ths of a second.
+
+
+ You can refer to these values in GDB expressions with the usual
+conventions; for example, `b fputc if $cycles>5000' sets a conditional
+breakpoint that suspends only after at least 5000 simulated clock ticks.
+
+
+File: gdb.info, Node: AVR, Next: CRIS, Prev: Z8000, Up: Embedded Processors
+
+21.3.12 Atmel AVR
+-----------------
+
+When configured for debugging the Atmel AVR, GDB supports the following
+AVR-specific commands:
+
+`info io_registers'
+ This command displays information about the AVR I/O registers. For
+ each register, GDB prints its number and value.
+
+
+File: gdb.info, Node: CRIS, Next: Super-H, Prev: AVR, Up: Embedded Processors
+
+21.3.13 CRIS
+------------
+
+When configured for debugging CRIS, GDB provides the following
+CRIS-specific commands:
+
+`set cris-version VER'
+ Set the current CRIS version to VER, either `10' or `32'. The
+ CRIS version affects register names and sizes. This command is
+ useful in case autodetection of the CRIS version fails.
+
+`show cris-version'
+ Show the current CRIS version.
+
+`set cris-dwarf2-cfi'
+ Set the usage of DWARF-2 CFI for CRIS debugging. The default is
+ `on'. Change to `off' when using `gcc-cris' whose version is below
+ `R59'.
+
+`show cris-dwarf2-cfi'
+ Show the current state of using DWARF-2 CFI.
+
+`set cris-mode MODE'
+ Set the current CRIS mode to MODE. It should only be changed when
+ debugging in guru mode, in which case it should be set to `guru'
+ (the default is `normal').
+
+`show cris-mode'
+ Show the current CRIS mode.
+
+
+File: gdb.info, Node: Super-H, Prev: CRIS, Up: Embedded Processors
+
+21.3.14 Renesas Super-H
+-----------------------
+
+For the Renesas Super-H processor, GDB provides these commands:
+
+`regs'
+ Show the values of all Super-H registers.
+
+`set sh calling-convention CONVENTION'
+ Set the calling-convention used when calling functions from GDB.
+ Allowed values are `gcc', which is the default setting, and
+ `renesas'. With the `gcc' setting, functions are called using the
+ GCC calling convention. If the DWARF-2 information of the called
+ function specifies that the function follows the Renesas calling
+ convention, the function is called using the Renesas calling
+ convention. If the calling convention is set to `renesas', the
+ Renesas calling convention is always used, regardless of the
+ DWARF-2 information. This can be used to override the default of
+ `gcc' if debug information is missing, or the compiler does not
+ emit the DWARF-2 calling convention entry for a function.
+
+`show sh calling-convention'
+ Show the current calling convention setting.
+
+
+
+File: gdb.info, Node: Architectures, Prev: Embedded Processors, Up: Configurations
+
+21.4 Architectures
+==================
+
+This section describes characteristics of architectures that affect all
+uses of GDB with the architecture, both native and cross.
+
+* Menu:
+
+* i386::
+* A29K::
+* Alpha::
+* MIPS::
+* HPPA:: HP PA architecture
+* SPU:: Cell Broadband Engine SPU architecture
+* PowerPC::
+
+
+File: gdb.info, Node: i386, Next: A29K, Up: Architectures
+
+21.4.1 x86 Architecture-specific Issues
+---------------------------------------
+
+`set struct-convention MODE'
+ Set the convention used by the inferior to return `struct's and
+ `union's from functions to MODE. Possible values of MODE are
+ `"pcc"', `"reg"', and `"default"' (the default). `"default"' or
+ `"pcc"' means that `struct's are returned on the stack, while
+ `"reg"' means that a `struct' or a `union' whose size is 1, 2, 4,
+ or 8 bytes will be returned in a register.
+
+`show struct-convention'
+ Show the current setting of the convention to return `struct's
+ from functions.
+
+
+File: gdb.info, Node: A29K, Next: Alpha, Prev: i386, Up: Architectures
+
+21.4.2 A29K
+-----------
+
+`set rstack_high_address ADDRESS'
+ On AMD 29000 family processors, registers are saved in a separate
+ "register stack". There is no way for GDB to determine the extent
+ of this stack. Normally, GDB just assumes that the stack is
+ "large enough". This may result in GDB referencing memory
+ locations that do not exist. If necessary, you can get around
+ this problem by specifying the ending address of the register
+ stack with the `set rstack_high_address' command. The argument
+ should be an address, which you probably want to precede with `0x'
+ to specify in hexadecimal.
+
+`show rstack_high_address'
+ Display the current limit of the register stack, on AMD 29000
+ family processors.
+
+
+
+File: gdb.info, Node: Alpha, Next: MIPS, Prev: A29K, Up: Architectures
+
+21.4.3 Alpha
+------------
+
+See the following section.
+
+
+File: gdb.info, Node: MIPS, Next: HPPA, Prev: Alpha, Up: Architectures
+
+21.4.4 MIPS
+-----------
+
+Alpha- and MIPS-based computers use an unusual stack frame, which
+sometimes requires GDB to search backward in the object code to find
+the beginning of a function.
+
+ To improve response time (especially for embedded applications, where
+GDB may be restricted to a slow serial line for this search) you may
+want to limit the size of this search, using one of these commands:
+
+`set heuristic-fence-post LIMIT'
+ Restrict GDB to examining at most LIMIT bytes in its search for
+ the beginning of a function. A value of 0 (the default) means
+ there is no limit. However, except for 0, the larger the limit
+ the more bytes `heuristic-fence-post' must search and therefore
+ the longer it takes to run. You should only need to use this
+ command when debugging a stripped executable.
+
+`show heuristic-fence-post'
+ Display the current limit.
+
+These commands are available _only_ when GDB is configured for
+debugging programs on Alpha or MIPS processors.
+
+ Several MIPS-specific commands are available when debugging MIPS
+programs:
+
+`set mips abi ARG'
+ Tell GDB which MIPS ABI is used by the inferior. Possible values
+ of ARG are:
+
+ `auto'
+ The default ABI associated with the current binary (this is
+ the default).
+
+ `o32'
+
+ `o64'
+
+ `n32'
+
+ `n64'
+
+ `eabi32'
+
+ `eabi64'
+
+`show mips abi'
+ Show the MIPS ABI used by GDB to debug the inferior.
+
+`set mipsfpu'
+`show mipsfpu'
+ *Note set mipsfpu: MIPS Embedded.
+
+`set mips mask-address ARG'
+ This command determines whether the most-significant 32 bits of
+ 64-bit MIPS addresses are masked off. The argument ARG can be
+ `on', `off', or `auto'. The latter is the default setting, which
+ lets GDB determine the correct value.
+
+`show mips mask-address'
+ Show whether the upper 32 bits of MIPS addresses are masked off or
+ not.
+
+`set remote-mips64-transfers-32bit-regs'
+ This command controls compatibility with 64-bit MIPS targets that
+ transfer data in 32-bit quantities. If you have an old MIPS 64
+ target that transfers 32 bits for some registers, like SR and FSR,
+ and 64 bits for other registers, set this option to `on'.
+
+`show remote-mips64-transfers-32bit-regs'
+ Show the current setting of compatibility with older MIPS 64
+ targets.
+
+`set debug mips'
+ This command turns on and off debugging messages for the
+ MIPS-specific target code in GDB.
+
+`show debug mips'
+ Show the current setting of MIPS debugging messages.
+
+
+File: gdb.info, Node: HPPA, Next: SPU, Prev: MIPS, Up: Architectures
+
+21.4.5 HPPA
+-----------
+
+When GDB is debugging the HP PA architecture, it provides the following
+special commands:
+
+`set debug hppa'
+ This command determines whether HPPA architecture-specific
+ debugging messages are to be displayed.
+
+`show debug hppa'
+ Show whether HPPA debugging messages are displayed.
+
+`maint print unwind ADDRESS'
+ This command displays the contents of the unwind table entry at the
+ given ADDRESS.
+
+
+
+File: gdb.info, Node: SPU, Next: PowerPC, Prev: HPPA, Up: Architectures
+
+21.4.6 Cell Broadband Engine SPU architecture
+---------------------------------------------
+
+When GDB is debugging the Cell Broadband Engine SPU architecture, it
+provides the following special commands:
+
+`info spu event'
+ Display SPU event facility status. Shows current event mask and
+ pending event status.
+
+`info spu signal'
+ Display SPU signal notification facility status. Shows pending
+ signal-control word and signal notification mode of both signal
+ notification channels.
+
+`info spu mailbox'
+ Display SPU mailbox facility status. Shows all pending entries,
+ in order of processing, in each of the SPU Write Outbound, SPU
+ Write Outbound Interrupt, and SPU Read Inbound mailboxes.
+
+`info spu dma'
+ Display MFC DMA status. Shows all pending commands in the MFC DMA
+ queue. For each entry, opcode, tag, class IDs, effective and
+ local store addresses and transfer size are shown.
+
+`info spu proxydma'
+ Display MFC Proxy-DMA status. Shows all pending commands in the
+ MFC Proxy-DMA queue. For each entry, opcode, tag, class IDs,
+ effective and local store addresses and transfer size are shown.
+
+
+ When GDB is debugging a combined PowerPC/SPU application on the Cell
+Broadband Engine, it provides in addition the following special
+commands:
+
+`set spu stop-on-load ARG'
+ Set whether to stop for new SPE threads. When set to `on', GDB
+ will give control to the user when a new SPE thread enters its
+ `main' function. The default is `off'.
+
+`show spu stop-on-load'
+ Show whether to stop for new SPE threads.
+
+`set spu auto-flush-cache ARG'
+ Set whether to automatically flush the software-managed cache.
+ When set to `on', GDB will automatically cause the SPE
+ software-managed cache to be flushed whenever SPE execution stops.
+ This provides a consistent view of PowerPC memory that is
+ accessed via the cache. If an application does not use the
+ software-managed cache, this option has no effect.
+
+`show spu auto-flush-cache'
+ Show whether to automatically flush the software-managed cache.
+
+
+
+File: gdb.info, Node: PowerPC, Prev: SPU, Up: Architectures
+
+21.4.7 PowerPC
+--------------
+
+When GDB is debugging the PowerPC architecture, it provides a set of
+pseudo-registers to enable inspection of 128-bit wide Decimal Floating
+Point numbers stored in the floating point registers. These values must
+be stored in two consecutive registers, always starting at an even
+register like `f0' or `f2'.
+
+ The pseudo-registers go from `$dl0' through `$dl15', and are formed
+by joining the even/odd register pairs `f0' and `f1' for `$dl0', `f2'
+and `f3' for `$dl1' and so on.
+
+ For POWER7 processors, GDB provides a set of pseudo-registers, the
+64-bit wide Extended Floating Point Registers (`f32' through `f63').
+
+
+File: gdb.info, Node: Controlling GDB, Next: Extending GDB, Prev: Configurations, Up: Top
+
+22 Controlling GDB
+******************
+
+You can alter the way GDB interacts with you by using the `set'
+command. For commands controlling how GDB displays data, see *Note
+Print Settings: Print Settings. Other settings are described here.
+
+* Menu:
+
+* Prompt:: Prompt
+* Editing:: Command editing
+* Command History:: Command history
+* Screen Size:: Screen size
+* Numbers:: Numbers
+* ABI:: Configuring the current ABI
+* Messages/Warnings:: Optional warnings and messages
+* Debugging Output:: Optional messages about internal happenings
+* Other Misc Settings:: Other Miscellaneous Settings
+
+
+File: gdb.info, Node: Prompt, Next: Editing, Up: Controlling GDB
+
+22.1 Prompt
+===========
+
+GDB indicates its readiness to read a command by printing a string
+called the "prompt". This string is normally `(gdb)'. You can change
+the prompt string with the `set prompt' command. For instance, when
+debugging GDB with GDB, it is useful to change the prompt in one of the
+GDB sessions so that you can always tell which one you are talking to.
+
+ _Note:_ `set prompt' does not add a space for you after the prompt
+you set. This allows you to set a prompt which ends in a space or a
+prompt that does not.
+
+`set prompt NEWPROMPT'
+ Directs GDB to use NEWPROMPT as its prompt string henceforth.
+
+`show prompt'
+ Prints a line of the form: `Gdb's prompt is: YOUR-PROMPT'
+
+ Versions of GDB that ship with Python scripting enabled have prompt
+extensions. The commands for interacting with these extensions are:
+
+`set extended-prompt PROMPT'
+ Set an extended prompt that allows for substitutions. *Note
+ gdb.prompt::, for a list of escape sequences that can be used for
+ substitution. Any escape sequences specified as part of the prompt
+ string are replaced with the corresponding strings each time the
+ prompt is displayed.
+
+ For example:
+
+ set extended-prompt Current working directory: \w (gdb)
+
+ Note that when an extended-prompt is set, it takes control of the
+ PROMPT_HOOK hook. *Note prompt_hook::, for further information.
+
+`show extended-prompt'
+ Prints the extended prompt. Any escape sequences specified as
+ part of the prompt string with `set extended-prompt', are replaced
+ with the corresponding strings each time the prompt is displayed.
+
+
+File: gdb.info, Node: Editing, Next: Command History, Prev: Prompt, Up: Controlling GDB
+
+22.2 Command Editing
+====================
+
+GDB reads its input commands via the "Readline" interface. This GNU
+library provides consistent behavior for programs which provide a
+command line interface to the user. Advantages are GNU Emacs-style or
+"vi"-style inline editing of commands, `csh'-like history substitution,
+and a storage and recall of command history across debugging sessions.
+
+ You may control the behavior of command line editing in GDB with the
+command `set'.
+
+`set editing'
+`set editing on'
+ Enable command line editing (enabled by default).
+
+`set editing off'
+ Disable command line editing.
+
+`show editing'
+ Show whether command line editing is enabled.
+
+ *Note Command Line Editing::, for more details about the Readline
+interface. Users unfamiliar with GNU Emacs or `vi' are encouraged to
+read that chapter.
+
+
+File: gdb.info, Node: Command History, Next: Screen Size, Prev: Editing, Up: Controlling GDB
+
+22.3 Command History
+====================
+
+GDB can keep track of the commands you type during your debugging
+sessions, so that you can be certain of precisely what happened. Use
+these commands to manage the GDB command history facility.
+
+ GDB uses the GNU History library, a part of the Readline package, to
+provide the history facility. *Note Using History Interactively::, for
+the detailed description of the History library.
+
+ To issue a command to GDB without affecting certain aspects of the
+state which is seen by users, prefix it with `server ' (*note Server
+Prefix::). This means that this command will not affect the command
+history, nor will it affect GDB's notion of which command to repeat if
+<RET> is pressed on a line by itself.
+
+ The server prefix does not affect the recording of values into the
+value history; to print a value without recording it into the value
+history, use the `output' command instead of the `print' command.
+
+ Here is the description of GDB commands related to command history.
+
+`set history filename FNAME'
+ Set the name of the GDB command history file to FNAME. This is
+ the file where GDB reads an initial command history list, and
+ where it writes the command history from this session when it
+ exits. You can access this list through history expansion or
+ through the history command editing characters listed below. This
+ file defaults to the value of the environment variable
+ `GDBHISTFILE', or to `./.gdb_history' (`./_gdb_history' on MS-DOS)
+ if this variable is not set.
+
+`set history save'
+`set history save on'
+ Record command history in a file, whose name may be specified with
+ the `set history filename' command. By default, this option is
+ disabled.
+
+`set history save off'
+ Stop recording command history in a file.
+
+`set history size SIZE'
+ Set the number of commands which GDB keeps in its history list.
+ This defaults to the value of the environment variable `HISTSIZE',
+ or to 256 if this variable is not set.
+
+ History expansion assigns special meaning to the character `!'.
+*Note Event Designators::, for more details.
+
+ Since `!' is also the logical not operator in C, history expansion
+is off by default. If you decide to enable history expansion with the
+`set history expansion on' command, you may sometimes need to follow
+`!' (when it is used as logical not, in an expression) with a space or
+a tab to prevent it from being expanded. The readline history
+facilities do not attempt substitution on the strings `!=' and `!(',
+even when history expansion is enabled.
+
+ The commands to control history expansion are:
+
+`set history expansion on'
+`set history expansion'
+ Enable history expansion. History expansion is off by default.
+
+`set history expansion off'
+ Disable history expansion.
+
+`show history'
+`show history filename'
+`show history save'
+`show history size'
+`show history expansion'
+ These commands display the state of the GDB history parameters.
+ `show history' by itself displays all four states.
+
+`show commands'
+ Display the last ten commands in the command history.
+
+`show commands N'
+ Print ten commands centered on command number N.
+
+`show commands +'
+ Print ten commands just after the commands last printed.
+
+
+File: gdb.info, Node: Screen Size, Next: Numbers, Prev: Command History, Up: Controlling GDB
+
+22.4 Screen Size
+================
+
+Certain commands to GDB may produce large amounts of information output
+to the screen. To help you read all of it, GDB pauses and asks you for
+input at the end of each page of output. Type <RET> when you want to
+continue the output, or `q' to discard the remaining output. Also, the
+screen width setting determines when to wrap lines of output.
+Depending on what is being printed, GDB tries to break the line at a
+readable place, rather than simply letting it overflow onto the
+following line.
+
+ Normally GDB knows the size of the screen from the terminal driver
+software. For example, on Unix GDB uses the termcap data base together
+with the value of the `TERM' environment variable and the `stty rows'
+and `stty cols' settings. If this is not correct, you can override it
+with the `set height' and `set width' commands:
+
+`set height LPP'
+`show height'
+`set width CPL'
+`show width'
+ These `set' commands specify a screen height of LPP lines and a
+ screen width of CPL characters. The associated `show' commands
+ display the current settings.
+
+ If you specify a height of zero lines, GDB does not pause during
+ output no matter how long the output is. This is useful if output
+ is to a file or to an editor buffer.
+
+ Likewise, you can specify `set width 0' to prevent GDB from
+ wrapping its output.
+
+`set pagination on'
+`set pagination off'
+ Turn the output pagination on or off; the default is on. Turning
+ pagination off is the alternative to `set height 0'. Note that
+ running GDB with the `--batch' option (*note -batch: Mode
+ Options.) also automatically disables pagination.
+
+`show pagination'
+ Show the current pagination mode.
+
+
+File: gdb.info, Node: Numbers, Next: ABI, Prev: Screen Size, Up: Controlling GDB
+
+22.5 Numbers
+============
+
+You can always enter numbers in octal, decimal, or hexadecimal in GDB
+by the usual conventions: octal numbers begin with `0', decimal numbers
+end with `.', and hexadecimal numbers begin with `0x'. Numbers that
+neither begin with `0' or `0x', nor end with a `.' are, by default,
+entered in base 10; likewise, the default display for numbers--when no
+particular format is specified--is base 10. You can change the default
+base for both input and output with the commands described below.
+
+`set input-radix BASE'
+ Set the default base for numeric input. Supported choices for
+ BASE are decimal 8, 10, or 16. BASE must itself be specified
+ either unambiguously or using the current input radix; for
+ example, any of
+
+ set input-radix 012
+ set input-radix 10.
+ set input-radix 0xa
+
+ sets the input base to decimal. On the other hand, `set
+ input-radix 10' leaves the input radix unchanged, no matter what
+ it was, since `10', being without any leading or trailing signs of
+ its base, is interpreted in the current radix. Thus, if the
+ current radix is 16, `10' is interpreted in hex, i.e. as 16
+ decimal, which doesn't change the radix.
+
+`set output-radix BASE'
+ Set the default base for numeric display. Supported choices for
+ BASE are decimal 8, 10, or 16. BASE must itself be specified
+ either unambiguously or using the current input radix.
+
+`show input-radix'
+ Display the current default base for numeric input.
+
+`show output-radix'
+ Display the current default base for numeric display.
+
+`set radix [BASE]'
+`show radix'
+ These commands set and show the default base for both input and
+ output of numbers. `set radix' sets the radix of input and output
+ to the same base; without an argument, it resets the radix back to
+ its default value of 10.
+
+
+
+File: gdb.info, Node: ABI, Next: Messages/Warnings, Prev: Numbers, Up: Controlling GDB
+
+22.6 Configuring the Current ABI
+================================
+
+GDB can determine the "ABI" (Application Binary Interface) of your
+application automatically. However, sometimes you need to override its
+conclusions. Use these commands to manage GDB's view of the current
+ABI.
+
+ One GDB configuration can debug binaries for multiple operating
+system targets, either via remote debugging or native emulation. GDB
+will autodetect the "OS ABI" (Operating System ABI) in use, but you can
+override its conclusion using the `set osabi' command. One example
+where this is useful is in debugging of binaries which use an alternate
+C library (e.g. UCLIBC for GNU/Linux) which does not have the same
+identifying marks that the standard C library for your platform
+provides.
+
+`show osabi'
+ Show the OS ABI currently in use.
+
+`set osabi'
+ With no argument, show the list of registered available OS ABI's.
+
+`set osabi ABI'
+ Set the current OS ABI to ABI.
+
+ Generally, the way that an argument of type `float' is passed to a
+function depends on whether the function is prototyped. For a
+prototyped (i.e. ANSI/ISO style) function, `float' arguments are passed
+unchanged, according to the architecture's convention for `float'. For
+unprototyped (i.e. K&R style) functions, `float' arguments are first
+promoted to type `double' and then passed.
+
+ Unfortunately, some forms of debug information do not reliably
+indicate whether a function is prototyped. If GDB calls a function
+that is not marked as prototyped, it consults `set
+coerce-float-to-double'.
+
+`set coerce-float-to-double'
+`set coerce-float-to-double on'
+ Arguments of type `float' will be promoted to `double' when passed
+ to an unprototyped function. This is the default setting.
+
+`set coerce-float-to-double off'
+ Arguments of type `float' will be passed directly to unprototyped
+ functions.
+
+`show coerce-float-to-double'
+ Show the current setting of promoting `float' to `double'.
+
+ GDB needs to know the ABI used for your program's C++ objects. The
+correct C++ ABI depends on which C++ compiler was used to build your
+application. GDB only fully supports programs with a single C++ ABI;
+if your program contains code using multiple C++ ABI's or if GDB can
+not identify your program's ABI correctly, you can tell GDB which ABI
+to use. Currently supported ABI's include "gnu-v2", for `g++' versions
+before 3.0, "gnu-v3", for `g++' versions 3.0 and later, and "hpaCC" for
+the HP ANSI C++ compiler. Other C++ compilers may use the "gnu-v2" or
+"gnu-v3" ABI's as well. The default setting is "auto".
+
+`show cp-abi'
+ Show the C++ ABI currently in use.
+
+`set cp-abi'
+ With no argument, show the list of supported C++ ABI's.
+
+`set cp-abi ABI'
+`set cp-abi auto'
+ Set the current C++ ABI to ABI, or return to automatic detection.
+
+
+File: gdb.info, Node: Messages/Warnings, Next: Debugging Output, Prev: ABI, Up: Controlling GDB
+
+22.7 Optional Warnings and Messages
+===================================
+
+By default, GDB is silent about its inner workings. If you are running
+on a slow machine, you may want to use the `set verbose' command. This
+makes GDB tell you when it does a lengthy internal operation, so you
+will not think it has crashed.
+
+ Currently, the messages controlled by `set verbose' are those which
+announce that the symbol table for a source file is being read; see
+`symbol-file' in *Note Commands to Specify Files: Files.
+
+`set verbose on'
+ Enables GDB output of certain informational messages.
+
+`set verbose off'
+ Disables GDB output of certain informational messages.
+
+`show verbose'
+ Displays whether `set verbose' is on or off.
+
+ By default, if GDB encounters bugs in the symbol table of an object
+file, it is silent; but if you are debugging a compiler, you may find
+this information useful (*note Errors Reading Symbol Files: Symbol
+Errors.).
+
+`set complaints LIMIT'
+ Permits GDB to output LIMIT complaints about each type of unusual
+ symbols before becoming silent about the problem. Set LIMIT to
+ zero to suppress all complaints; set it to a large number to
+ prevent complaints from being suppressed.
+
+`show complaints'
+ Displays how many symbol complaints GDB is permitted to produce.
+
+
+ By default, GDB is cautious, and asks what sometimes seems to be a
+lot of stupid questions to confirm certain commands. For example, if
+you try to run a program which is already running:
+
+ (gdb) run
+ The program being debugged has been started already.
+ Start it from the beginning? (y or n)
+
+ If you are willing to unflinchingly face the consequences of your own
+commands, you can disable this "feature":
+
+`set confirm off'
+ Disables confirmation requests. Note that running GDB with the
+ `--batch' option (*note -batch: Mode Options.) also automatically
+ disables confirmation requests.
+
+`set confirm on'
+ Enables confirmation requests (the default).
+
+`show confirm'
+ Displays state of confirmation requests.
+
+
+ If you need to debug user-defined commands or sourced files you may
+find it useful to enable "command tracing". In this mode each command
+will be printed as it is executed, prefixed with one or more `+'
+symbols, the quantity denoting the call depth of each command.
+
+`set trace-commands on'
+ Enable command tracing.
+
+`set trace-commands off'
+ Disable command tracing.
+
+`show trace-commands'
+ Display the current state of command tracing.
+
+
+File: gdb.info, Node: Debugging Output, Next: Other Misc Settings, Prev: Messages/Warnings, Up: Controlling GDB
+
+22.8 Optional Messages about Internal Happenings
+================================================
+
+GDB has commands that enable optional debugging messages from various
+GDB subsystems; normally these commands are of interest to GDB
+maintainers, or when reporting a bug. This section documents those
+commands.
+
+`set exec-done-display'
+ Turns on or off the notification of asynchronous commands'
+ completion. When on, GDB will print a message when an
+ asynchronous command finishes its execution. The default is off.
+
+`show exec-done-display'
+ Displays the current setting of asynchronous command completion
+ notification.
+
+`set debug arch'
+ Turns on or off display of gdbarch debugging info. The default is
+ off
+
+`show debug arch'
+ Displays the current state of displaying gdbarch debugging info.
+
+`set debug aix-thread'
+ Display debugging messages about inner workings of the AIX thread
+ module.
+
+`show debug aix-thread'
+ Show the current state of AIX thread debugging info display.
+
+`set debug check-physname'
+ Check the results of the "physname" computation. When reading
+ DWARF debugging information for C++, GDB attempts to compute each
+ entity's name. GDB can do this computation in two different ways,
+ depending on exactly what information is present. When enabled,
+ this setting causes GDB to compute the names both ways and display
+ any discrepancies.
+
+`show debug check-physname'
+ Show the current state of "physname" checking.
+
+`set debug dwarf2-die'
+ Dump DWARF2 DIEs after they are read in. The value is the number
+ of nesting levels to print. A value of zero turns off the display.
+
+`show debug dwarf2-die'
+ Show the current state of DWARF2 DIE debugging.
+
+`set debug displaced'
+ Turns on or off display of GDB debugging info for the displaced
+ stepping support. The default is off.
+
+`show debug displaced'
+ Displays the current state of displaying GDB debugging info
+ related to displaced stepping.
+
+`set debug event'
+ Turns on or off display of GDB event debugging info. The default
+ is off.
+
+`show debug event'
+ Displays the current state of displaying GDB event debugging info.
+
+`set debug expression'
+ Turns on or off display of debugging info about GDB expression
+ parsing. The default is off.
+
+`show debug expression'
+ Displays the current state of displaying debugging info about GDB
+ expression parsing.
+
+`set debug frame'
+ Turns on or off display of GDB frame debugging info. The default
+ is off.
+
+`show debug frame'
+ Displays the current state of displaying GDB frame debugging info.
+
+`set debug gnu-nat'
+ Turns on or off debugging messages from the GNU/Hurd debug support.
+
+`show debug gnu-nat'
+ Show the current state of GNU/Hurd debugging messages.
+
+`set debug infrun'
+ Turns on or off display of GDB debugging info for running the
+ inferior. The default is off. `infrun.c' contains GDB's runtime
+ state machine used for implementing operations such as
+ single-stepping the inferior.
+
+`show debug infrun'
+ Displays the current state of GDB inferior debugging.
+
+`set debug jit'
+ Turns on or off debugging messages from JIT debug support.
+
+`show debug jit'
+ Displays the current state of GDB JIT debugging.
+
+`set debug lin-lwp'
+ Turns on or off debugging messages from the Linux LWP debug
+ support.
+
+`show debug lin-lwp'
+ Show the current state of Linux LWP debugging messages.
+
+`set debug observer'
+ Turns on or off display of GDB observer debugging. This includes
+ info such as the notification of observable events.
+
+`show debug observer'
+ Displays the current state of observer debugging.
+
+`set debug overload'
+ Turns on or off display of GDB C++ overload debugging info. This
+ includes info such as ranking of functions, etc. The default is
+ off.
+
+`show debug overload'
+ Displays the current state of displaying GDB C++ overload
+ debugging info.
+
+`set debug parser'
+ Turns on or off the display of expression parser debugging output.
+ Internally, this sets the `yydebug' variable in the expression
+ parser. *Note Tracing Your Parser: (bison)Tracing, for details.
+ The default is off.
+
+`show debug parser'
+ Show the current state of expression parser debugging.
+
+`set debug remote'
+ Turns on or off display of reports on all packets sent back and
+ forth across the serial line to the remote machine. The info is
+ printed on the GDB standard output stream. The default is off.
+
+`show debug remote'
+ Displays the state of display of remote packets.
+
+`set debug serial'
+ Turns on or off display of GDB serial debugging info. The default
+ is off.
+
+`show debug serial'
+ Displays the current state of displaying GDB serial debugging info.
+
+`set debug solib-frv'
+ Turns on or off debugging messages for FR-V shared-library code.
+
+`show debug solib-frv'
+ Display the current state of FR-V shared-library code debugging
+ messages.
+
+`set debug target'
+ Turns on or off display of GDB target debugging info. This info
+ includes what is going on at the target level of GDB, as it
+ happens. The default is 0. Set it to 1 to track events, and to 2
+ to also track the value of large memory transfers. Changes to
+ this flag do not take effect until the next time you connect to a
+ target or use the `run' command.
+
+`show debug target'
+ Displays the current state of displaying GDB target debugging info.
+
+`set debug timestamp'
+ Turns on or off display of timestamps with GDB debugging info.
+ When enabled, seconds and microseconds are displayed before each
+ debugging message.
+
+`show debug timestamp'
+ Displays the current state of displaying timestamps with GDB
+ debugging info.
+
+`set debugvarobj'
+ Turns on or off display of GDB variable object debugging info. The
+ default is off.
+
+`show debugvarobj'
+ Displays the current state of displaying GDB variable object
+ debugging info.
+
+`set debug xml'
+ Turns on or off debugging messages for built-in XML parsers.
+
+`show debug xml'
+ Displays the current state of XML debugging messages.
+
+
+File: gdb.info, Node: Other Misc Settings, Prev: Debugging Output, Up: Controlling GDB
+
+22.9 Other Miscellaneous Settings
+=================================
+
+`set interactive-mode'
+ If `on', forces GDB to assume that GDB was started in a terminal.
+ In practice, this means that GDB should wait for the user to
+ answer queries generated by commands entered at the command
+ prompt. If `off', forces GDB to operate in the opposite mode, and
+ it uses the default answers to all queries. If `auto' (the
+ default), GDB tries to determine whether its standard input is a
+ terminal, and works in interactive-mode if it is,
+ non-interactively otherwise.
+
+ In the vast majority of cases, the debugger should be able to guess
+ correctly which mode should be used. But this setting can be
+ useful in certain specific cases, such as running a MinGW GDB
+ inside a cygwin window.
+
+`show interactive-mode'
+ Displays whether the debugger is operating in interactive mode or
+ not.
+
+
+File: gdb.info, Node: Extending GDB, Next: Interpreters, Prev: Controlling GDB, Up: Top
+
+23 Extending GDB
+****************
+
+GDB provides three mechanisms for extension. The first is based on
+composition of GDB commands, the second is based on the Python
+scripting language, and the third is for defining new aliases of
+existing commands.
+
+ To facilitate the use of the first two extensions, GDB is capable of
+evaluating the contents of a file. When doing so, GDB can recognize
+which scripting language is being used by looking at the filename
+extension. Files with an unrecognized filename extension are always
+treated as a GDB Command Files. *Note Command files: Command Files.
+
+ You can control how GDB evaluates these files with the following
+setting:
+
+`set script-extension off'
+ All scripts are always evaluated as GDB Command Files.
+
+`set script-extension soft'
+ The debugger determines the scripting language based on filename
+ extension. If this scripting language is supported, GDB evaluates
+ the script using that language. Otherwise, it evaluates the file
+ as a GDB Command File.
+
+`set script-extension strict'
+ The debugger determines the scripting language based on filename
+ extension, and evaluates the script using that language. If the
+ language is not supported, then the evaluation fails.
+
+`show script-extension'
+ Display the current value of the `script-extension' option.
+
+
+* Menu:
+
+* Sequences:: Canned Sequences of Commands
+* Python:: Scripting GDB using Python
+* Aliases:: Creating new spellings of existing commands
+
+
+File: gdb.info, Node: Sequences, Next: Python, Up: Extending GDB
+
+23.1 Canned Sequences of Commands
+=================================
+
+Aside from breakpoint commands (*note Breakpoint Command Lists: Break
+Commands.), GDB provides two ways to store sequences of commands for
+execution as a unit: user-defined commands and command files.
+
+* Menu:
+
+* Define:: How to define your own commands
+* Hooks:: Hooks for user-defined commands
+* Command Files:: How to write scripts of commands to be stored in a file
+* Output:: Commands for controlled output
+
+
+File: gdb.info, Node: Define, Next: Hooks, Up: Sequences
+
+23.1.1 User-defined Commands
+----------------------------
+
+A "user-defined command" is a sequence of GDB commands to which you
+assign a new name as a command. This is done with the `define'
+command. User commands may accept up to 10 arguments separated by
+whitespace. Arguments are accessed within the user command via
+`$arg0...$arg9'. A trivial example:
+
+ define adder
+ print $arg0 + $arg1 + $arg2
+ end
+
+To execute the command use:
+
+ adder 1 2 3
+
+This defines the command `adder', which prints the sum of its three
+arguments. Note the arguments are text substitutions, so they may
+reference variables, use complex expressions, or even perform inferior
+functions calls.
+
+ In addition, `$argc' may be used to find out how many arguments have
+been passed. This expands to a number in the range 0...10.
+
+ define adder
+ if $argc == 2
+ print $arg0 + $arg1
+ end
+ if $argc == 3
+ print $arg0 + $arg1 + $arg2
+ end
+ end
+
+`define COMMANDNAME'
+ Define a command named COMMANDNAME. If there is already a command
+ by that name, you are asked to confirm that you want to redefine
+ it. COMMANDNAME may be a bare command name consisting of letters,
+ numbers, dashes, and underscores. It may also start with any
+ predefined prefix command. For example, `define target my-target'
+ creates a user-defined `target my-target' command.
+
+ The definition of the command is made up of other GDB command
+ lines, which are given following the `define' command. The end of
+ these commands is marked by a line containing `end'.
+
+`document COMMANDNAME'
+ Document the user-defined command COMMANDNAME, so that it can be
+ accessed by `help'. The command COMMANDNAME must already be
+ defined. This command reads lines of documentation just as
+ `define' reads the lines of the command definition, ending with
+ `end'. After the `document' command is finished, `help' on command
+ COMMANDNAME displays the documentation you have written.
+
+ You may use the `document' command again to change the
+ documentation of a command. Redefining the command with `define'
+ does not change the documentation.
+
+`dont-repeat'
+ Used inside a user-defined command, this tells GDB that this
+ command should not be repeated when the user hits <RET> (*note
+ repeat last command: Command Syntax.).
+
+`help user-defined'
+ List all user-defined commands, with the first line of the
+ documentation (if any) for each.
+
+`show user'
+`show user COMMANDNAME'
+ Display the GDB commands used to define COMMANDNAME (but not its
+ documentation). If no COMMANDNAME is given, display the
+ definitions for all user-defined commands.
+
+`show max-user-call-depth'
+`set max-user-call-depth'
+ The value of `max-user-call-depth' controls how many recursion
+ levels are allowed in user-defined commands before GDB suspects an
+ infinite recursion and aborts the command.
+
+ In addition to the above commands, user-defined commands frequently
+use control flow commands, described in *Note Command Files::.
+
+ When user-defined commands are executed, the commands of the
+definition are not printed. An error in any command stops execution of
+the user-defined command.
+
+ If used interactively, commands that would ask for confirmation
+proceed without asking when used inside a user-defined command. Many
+GDB commands that normally print messages to say what they are doing
+omit the messages when used in a user-defined command.
+
+
+File: gdb.info, Node: Hooks, Next: Command Files, Prev: Define, Up: Sequences
+
+23.1.2 User-defined Command Hooks
+---------------------------------
+
+You may define "hooks", which are a special kind of user-defined
+command. Whenever you run the command `foo', if the user-defined
+command `hook-foo' exists, it is executed (with no arguments) before
+that command.
+
+ A hook may also be defined which is run after the command you
+executed. Whenever you run the command `foo', if the user-defined
+command `hookpost-foo' exists, it is executed (with no arguments) after
+that command. Post-execution hooks may exist simultaneously with
+pre-execution hooks, for the same command.
+
+ It is valid for a hook to call the command which it hooks. If this
+occurs, the hook is not re-executed, thereby avoiding infinite
+recursion.
+
+ In addition, a pseudo-command, `stop' exists. Defining
+(`hook-stop') makes the associated commands execute every time
+execution stops in your program: before breakpoint commands are run,
+displays are printed, or the stack frame is printed.
+
+ For example, to ignore `SIGALRM' signals while single-stepping, but
+treat them normally during normal execution, you could define:
+
+ define hook-stop
+ handle SIGALRM nopass
+ end
+
+ define hook-run
+ handle SIGALRM pass
+ end
+
+ define hook-continue
+ handle SIGALRM pass
+ end
+
+ As a further example, to hook at the beginning and end of the `echo'
+command, and to add extra text to the beginning and end of the message,
+you could define:
+
+ define hook-echo
+ echo <<<---
+ end
+
+ define hookpost-echo
+ echo --->>>\n
+ end
+
+ (gdb) echo Hello World
+ <<<---Hello World--->>>
+ (gdb)
+
+ You can define a hook for any single-word command in GDB, but not
+for command aliases; you should define a hook for the basic command
+name, e.g. `backtrace' rather than `bt'. You can hook a multi-word
+command by adding `hook-' or `hookpost-' to the last word of the
+command, e.g. `define target hook-remote' to add a hook to `target
+remote'.
+
+ If an error occurs during the execution of your hook, execution of
+GDB commands stops and GDB issues a prompt (before the command that you
+actually typed had a chance to run).
+
+ If you try to define a hook which does not match any known command,
+you get a warning from the `define' command.
+
+
+File: gdb.info, Node: Command Files, Next: Output, Prev: Hooks, Up: Sequences
+
+23.1.3 Command Files
+--------------------
+
+A command file for GDB is a text file made of lines that are GDB
+commands. Comments (lines starting with `#') may also be included. An
+empty line in a command file does nothing; it does not mean to repeat
+the last command, as it would from the terminal.
+
+ You can request the execution of a command file with the `source'
+command. Note that the `source' command is also used to evaluate
+scripts that are not Command Files. The exact behavior can be
+configured using the `script-extension' setting. *Note Extending GDB:
+Extending GDB.
+
+`source [-s] [-v] FILENAME'
+ Execute the command file FILENAME.
+
+ The lines in a command file are generally executed sequentially,
+unless the order of execution is changed by one of the _flow-control
+commands_ described below. The commands are not printed as they are
+executed. An error in any command terminates execution of the command
+file and control is returned to the console.
+
+ GDB first searches for FILENAME in the current directory. If the
+file is not found there, and FILENAME does not specify a directory,
+then GDB also looks for the file on the source search path (specified
+with the `directory' command); except that `$cdir' is not searched
+because the compilation directory is not relevant to scripts.
+
+ If `-s' is specified, then GDB searches for FILENAME on the search
+path even if FILENAME specifies a directory. The search is done by
+appending FILENAME to each element of the search path. So, for
+example, if FILENAME is `mylib/myscript' and the search path contains
+`/home/user' then GDB will look for the script
+`/home/user/mylib/myscript'. The search is also done if FILENAME is an
+absolute path. For example, if FILENAME is `/tmp/myscript' and the
+search path contains `/home/user' then GDB will look for the script
+`/home/user/tmp/myscript'. For DOS-like systems, if FILENAME contains
+a drive specification, it is stripped before concatenation. For
+example, if FILENAME is `d:myscript' and the search path contains
+`c:/tmp' then GDB will look for the script `c:/tmp/myscript'.
+
+ If `-v', for verbose mode, is given then GDB displays each command
+as it is executed. The option must be given before FILENAME, and is
+interpreted as part of the filename anywhere else.
+
+ Commands that would ask for confirmation if used interactively
+proceed without asking when used in a command file. Many GDB commands
+that normally print messages to say what they are doing omit the
+messages when called from command files.
+
+ GDB also accepts command input from standard input. In this mode,
+normal output goes to standard output and error output goes to standard
+error. Errors in a command file supplied on standard input do not
+terminate execution of the command file--execution continues with the
+next command.
+
+ gdb < cmds > log 2>&1
+
+ (The syntax above will vary depending on the shell used.) This
+example will execute commands from the file `cmds'. All output and
+errors would be directed to `log'.
+
+ Since commands stored on command files tend to be more general than
+commands typed interactively, they frequently need to deal with
+complicated situations, such as different or unexpected values of
+variables and symbols, changes in how the program being debugged is
+built, etc. GDB provides a set of flow-control commands to deal with
+these complexities. Using these commands, you can write complex
+scripts that loop over data structures, execute commands conditionally,
+etc.
+
+`if'
+`else'
+ This command allows to include in your script conditionally
+ executed commands. The `if' command takes a single argument, which
+ is an expression to evaluate. It is followed by a series of
+ commands that are executed only if the expression is true (its
+ value is nonzero). There can then optionally be an `else' line,
+ followed by a series of commands that are only executed if the
+ expression was false. The end of the list is marked by a line
+ containing `end'.
+
+`while'
+ This command allows to write loops. Its syntax is similar to
+ `if': the command takes a single argument, which is an expression
+ to evaluate, and must be followed by the commands to execute, one
+ per line, terminated by an `end'. These commands are called the
+ "body" of the loop. The commands in the body of `while' are
+ executed repeatedly as long as the expression evaluates to true.
+
+`loop_break'
+ This command exits the `while' loop in whose body it is included.
+ Execution of the script continues after that `while's `end' line.
+
+`loop_continue'
+ This command skips the execution of the rest of the body of
+ commands in the `while' loop in whose body it is included.
+ Execution branches to the beginning of the `while' loop, where it
+ evaluates the controlling expression.
+
+`end'
+ Terminate the block of commands that are the body of `if', `else',
+ or `while' flow-control commands.
+
+
+File: gdb.info, Node: Output, Prev: Command Files, Up: Sequences
+
+23.1.4 Commands for Controlled Output
+-------------------------------------
+
+During the execution of a command file or a user-defined command, normal
+GDB output is suppressed; the only output that appears is what is
+explicitly printed by the commands in the definition. This section
+describes three commands useful for generating exactly the output you
+want.
+
+`echo TEXT'
+ Print TEXT. Nonprinting characters can be included in TEXT using
+ C escape sequences, such as `\n' to print a newline. *No newline
+ is printed unless you specify one.* In addition to the standard C
+ escape sequences, a backslash followed by a space stands for a
+ space. This is useful for displaying a string with spaces at the
+ beginning or the end, since leading and trailing spaces are
+ otherwise trimmed from all arguments. To print ` and foo = ', use
+ the command `echo \ and foo = \ '.
+
+ A backslash at the end of TEXT can be used, as in C, to continue
+ the command onto subsequent lines. For example,
+
+ echo This is some text\n\
+ which is continued\n\
+ onto several lines.\n
+
+ produces the same output as
+
+ echo This is some text\n
+ echo which is continued\n
+ echo onto several lines.\n
+
+`output EXPRESSION'
+ Print the value of EXPRESSION and nothing but that value: no
+ newlines, no `$NN = '. The value is not entered in the value
+ history either. *Note Expressions: Expressions, for more
+ information on expressions.
+
+`output/FMT EXPRESSION'
+ Print the value of EXPRESSION in format FMT. You can use the same
+ formats as for `print'. *Note Output Formats: Output Formats, for
+ more information.
+
+`printf TEMPLATE, EXPRESSIONS...'
+ Print the values of one or more EXPRESSIONS under the control of
+ the string TEMPLATE. To print several values, make EXPRESSIONS be
+ a comma-separated list of individual expressions, which may be
+ either numbers or pointers. Their values are printed as specified
+ by TEMPLATE, exactly as a C program would do by executing the code
+ below:
+
+ printf (TEMPLATE, EXPRESSIONS...);
+
+ As in `C' `printf', ordinary characters in TEMPLATE are printed
+ verbatim, while "conversion specification" introduced by the `%'
+ character cause subsequent EXPRESSIONS to be evaluated, their
+ values converted and formatted according to type and style
+ information encoded in the conversion specifications, and then
+ printed.
+
+ For example, you can print two values in hex like this:
+
+ printf "foo, bar-foo = 0x%x, 0x%x\n", foo, bar-foo
+
+ `printf' supports all the standard `C' conversion specifications,
+ including the flags and modifiers between the `%' character and
+ the conversion letter, with the following exceptions:
+
+ * The argument-ordering modifiers, such as `2$', are not
+ supported.
+
+ * The modifier `*' is not supported for specifying precision or
+ width.
+
+ * The `'' flag (for separation of digits into groups according
+ to `LC_NUMERIC'') is not supported.
+
+ * The type modifiers `hh', `j', `t', and `z' are not supported.
+
+ * The conversion letter `n' (as in `%n') is not supported.
+
+ * The conversion letters `a' and `A' are not supported.
+
+ Note that the `ll' type modifier is supported only if the
+ underlying `C' implementation used to build GDB supports the `long
+ long int' type, and the `L' type modifier is supported only if
+ `long double' type is available.
+
+ As in `C', `printf' supports simple backslash-escape sequences,
+ such as `\n', `\t', `\\', `\"', `\a', and `\f', that consist of
+ backslash followed by a single character. Octal and hexadecimal
+ escape sequences are not supported.
+
+ Additionally, `printf' supports conversion specifications for DFP
+ ("Decimal Floating Point") types using the following length
+ modifiers together with a floating point specifier. letters:
+
+ * `H' for printing `Decimal32' types.
+
+ * `D' for printing `Decimal64' types.
+
+ * `DD' for printing `Decimal128' types.
+
+ If the underlying `C' implementation used to build GDB has support
+ for the three length modifiers for DFP types, other modifiers such
+ as width and precision will also be available for GDB to use.
+
+ In case there is no such `C' support, no additional modifiers will
+ be available and the value will be printed in the standard way.
+
+ Here's an example of printing DFP types using the above conversion
+ letters:
+ printf "D32: %Hf - D64: %Df - D128: %DDf\n",1.2345df,1.2E10dd,1.2E1dl
+
+`eval TEMPLATE, EXPRESSIONS...'
+ Convert the values of one or more EXPRESSIONS under the control of
+ the string TEMPLATE to a command line, and call it.
+
+
+
+File: gdb.info, Node: Python, Next: Aliases, Prev: Sequences, Up: Extending GDB
+
+23.2 Scripting GDB using Python
+===============================
+
+You can script GDB using the Python programming language
+(http://www.python.org/). This feature is available only if GDB was
+configured using `--with-python'.
+
+ Python scripts used by GDB should be installed in
+`DATA-DIRECTORY/python', where DATA-DIRECTORY is the data directory as
+determined at GDB startup (*note Data Files::). This directory, known
+as the "python directory", is automatically added to the Python Search
+Path in order to allow the Python interpreter to locate all scripts
+installed at this location.
+
+ Additionally, GDB commands and convenience functions which are
+written in Python and are located in the
+`DATA-DIRECTORY/python/gdb/command' or
+`DATA-DIRECTORY/python/gdb/function' directories are automatically
+imported when GDB starts.
+
+* Menu:
+
+* Python Commands:: Accessing Python from GDB.
+* Python API:: Accessing GDB from Python.
+* Auto-loading:: Automatically loading Python code.
+* Python modules:: Python modules provided by GDB.
+
+
+File: gdb.info, Node: Python Commands, Next: Python API, Up: Python
+
+23.2.1 Python Commands
+----------------------
+
+GDB provides one command for accessing the Python interpreter, and one
+related setting:
+
+`python [CODE]'
+ The `python' command can be used to evaluate Python code.
+
+ If given an argument, the `python' command will evaluate the
+ argument as a Python command. For example:
+
+ (gdb) python print 23
+ 23
+
+ If you do not provide an argument to `python', it will act as a
+ multi-line command, like `define'. In this case, the Python
+ script is made up of subsequent command lines, given after the
+ `python' command. This command list is terminated using a line
+ containing `end'. For example:
+
+ (gdb) python
+ Type python script
+ End with a line saying just "end".
+ >print 23
+ >end
+ 23
+
+`set python print-stack'
+ By default, GDB will print only the message component of a Python
+ exception when an error occurs in a Python script. This can be
+ controlled using `set python print-stack': if `full', then full
+ Python stack printing is enabled; if `none', then Python stack and
+ message printing is disabled; if `message', the default, only the
+ message component of the error is printed.
+
+ It is also possible to execute a Python script from the GDB
+interpreter:
+
+`source `script-name''
+ The script name must end with `.py' and GDB must be configured to
+ recognize the script language based on filename extension using
+ the `script-extension' setting. *Note Extending GDB: Extending
+ GDB.
+
+`python execfile ("script-name")'
+ This method is based on the `execfile' Python built-in function,
+ and thus is always available.
+
+
+File: gdb.info, Node: Python API, Next: Auto-loading, Prev: Python Commands, Up: Python
+
+23.2.2 Python API
+-----------------
+
+At startup, GDB overrides Python's `sys.stdout' and `sys.stderr' to
+print using GDB's output-paging streams. A Python program which
+outputs to one of these streams may have its output interrupted by the
+user (*note Screen Size::). In this situation, a Python
+`KeyboardInterrupt' exception is thrown.
+
+* Menu:
+
+* Basic Python:: Basic Python Functions.
+* Exception Handling:: How Python exceptions are translated.
+* Values From Inferior:: Python representation of values.
+* Types In Python:: Python representation of types.
+* Pretty Printing API:: Pretty-printing values.
+* Selecting Pretty-Printers:: How GDB chooses a pretty-printer.
+* Writing a Pretty-Printer:: Writing a Pretty-Printer.
+* Inferiors In Python:: Python representation of inferiors (processes)
+* Events In Python:: Listening for events from GDB.
+* Threads In Python:: Accessing inferior threads from Python.
+* Commands In Python:: Implementing new commands in Python.
+* Parameters In Python:: Adding new GDB parameters.
+* Functions In Python:: Writing new convenience functions.
+* Progspaces In Python:: Program spaces.
+* Objfiles In Python:: Object files.
+* Frames In Python:: Accessing inferior stack frames from Python.
+* Blocks In Python:: Accessing frame blocks from Python.
+* Symbols In Python:: Python representation of symbols.
+* Symbol Tables In Python:: Python representation of symbol tables.
+* Lazy Strings In Python:: Python representation of lazy strings.
+* Breakpoints In Python:: Manipulating breakpoints using Python.
+* Finish Breakpoints in Python:: Setting Breakpoints on function return
+ using Python.
+
+
+File: gdb.info, Node: Basic Python, Next: Exception Handling, Up: Python API
+
+23.2.2.1 Basic Python
+.....................
+
+GDB introduces a new Python module, named `gdb'. All methods and
+classes added by GDB are placed in this module. GDB automatically
+`import's the `gdb' module for use in all scripts evaluated by the
+`python' command.
+
+ -- Variable: gdb.PYTHONDIR
+ A string containing the python directory (*note Python::).
+
+ -- Function: gdb.execute (command [, from_tty [, to_string]])
+ Evaluate COMMAND, a string, as a GDB CLI command. If a GDB
+ exception happens while COMMAND runs, it is translated as
+ described in *Note Exception Handling: Exception Handling.
+
+ FROM_TTY specifies whether GDB ought to consider this command as
+ having originated from the user invoking it interactively. It
+ must be a boolean value. If omitted, it defaults to `False'.
+
+ By default, any output produced by COMMAND is sent to GDB's
+ standard output. If the TO_STRING parameter is `True', then
+ output will be collected by `gdb.execute' and returned as a
+ string. The default is `False', in which case the return value is
+ `None'. If TO_STRING is `True', the GDB virtual terminal will be
+ temporarily set to unlimited width and height, and its pagination
+ will be disabled; *note Screen Size::.
+
+ -- Function: gdb.breakpoints ()
+ Return a sequence holding all of GDB's breakpoints. *Note
+ Breakpoints In Python::, for more information.
+
+ -- Function: gdb.parameter (parameter)
+ Return the value of a GDB parameter. PARAMETER is a string naming
+ the parameter to look up; PARAMETER may contain spaces if the
+ parameter has a multi-part name. For example, `print object' is a
+ valid parameter name.
+
+ If the named parameter does not exist, this function throws a
+ `gdb.error' (*note Exception Handling::). Otherwise, the
+ parameter's value is converted to a Python value of the appropriate
+ type, and returned.
+
+ -- Function: gdb.history (number)
+ Return a value from GDB's value history (*note Value History::).
+ NUMBER indicates which history element to return. If NUMBER is
+ negative, then GDB will take its absolute value and count backward
+ from the last element (i.e., the most recent element) to find the
+ value to return. If NUMBER is zero, then GDB will return the most
+ recent element. If the element specified by NUMBER doesn't exist
+ in the value history, a `gdb.error' exception will be raised.
+
+ If no exception is raised, the return value is always an instance
+ of `gdb.Value' (*note Values From Inferior::).
+
+ -- Function: gdb.parse_and_eval (expression)
+ Parse EXPRESSION as an expression in the current language,
+ evaluate it, and return the result as a `gdb.Value'. EXPRESSION
+ must be a string.
+
+ This function can be useful when implementing a new command (*note
+ Commands In Python::), as it provides a way to parse the command's
+ argument as an expression. It is also useful simply to compute
+ values, for example, it is the only way to get the value of a
+ convenience variable (*note Convenience Vars::) as a `gdb.Value'.
+
+ -- Function: gdb.post_event (event)
+ Put EVENT, a callable object taking no arguments, into GDB's
+ internal event queue. This callable will be invoked at some later
+ point, during GDB's event processing. Events posted using
+ `post_event' will be run in the order in which they were posted;
+ however, there is no way to know when they will be processed
+ relative to other events inside GDB.
+
+ GDB is not thread-safe. If your Python program uses multiple
+ threads, you must be careful to only call GDB-specific functions
+ in the main GDB thread. `post_event' ensures this. For example:
+
+ (gdb) python
+ >import threading
+ >
+ >class Writer():
+ > def __init__(self, message):
+ > self.message = message;
+ > def __call__(self):
+ > gdb.write(self.message)
+ >
+ >class MyThread1 (threading.Thread):
+ > def run (self):
+ > gdb.post_event(Writer("Hello "))
+ >
+ >class MyThread2 (threading.Thread):
+ > def run (self):
+ > gdb.post_event(Writer("World\n"))
+ >
+ >MyThread1().start()
+ >MyThread2().start()
+ >end
+ (gdb) Hello World
+
+ -- Function: gdb.write (string [, stream])
+ Print a string to GDB's paginated output stream. The optional
+ STREAM determines the stream to print to. The default stream is
+ GDB's standard output stream. Possible stream values are:
+
+ `gdb.STDOUT'
+ GDB's standard output stream.
+
+ `gdb.STDERR'
+ GDB's standard error stream.
+
+ `gdb.STDLOG'
+ GDB's log stream (*note Logging Output::).
+
+ Writing to `sys.stdout' or `sys.stderr' will automatically call
+ this function and will automatically direct the output to the
+ relevant stream.
+
+ -- Function: gdb.flush ()
+ Flush the buffer of a GDB paginated stream so that the contents
+ are displayed immediately. GDB will flush the contents of a
+ stream automatically when it encounters a newline in the buffer.
+ The optional STREAM determines the stream to flush. The default
+ stream is GDB's standard output stream. Possible stream values
+ are:
+
+ `gdb.STDOUT'
+ GDB's standard output stream.
+
+ `gdb.STDERR'
+ GDB's standard error stream.
+
+ `gdb.STDLOG'
+ GDB's log stream (*note Logging Output::).
+
+
+ Flushing `sys.stdout' or `sys.stderr' will automatically call this
+ function for the relevant stream.
+
+ -- Function: gdb.target_charset ()
+ Return the name of the current target character set (*note
+ Character Sets::). This differs from
+ `gdb.parameter('target-charset')' in that `auto' is never returned.
+
+ -- Function: gdb.target_wide_charset ()
+ Return the name of the current target wide character set (*note
+ Character Sets::). This differs from
+ `gdb.parameter('target-wide-charset')' in that `auto' is never
+ returned.
+
+ -- Function: gdb.solib_name (address)
+ Return the name of the shared library holding the given ADDRESS as
+ a string, or `None'.
+
+ -- Function: gdb.decode_line [expression]
+ Return locations of the line specified by EXPRESSION, or of the
+ current line if no argument was given. This function returns a
+ Python tuple containing two elements. The first element contains
+ a string holding any unparsed section of EXPRESSION (or `None' if
+ the expression has been fully parsed). The second element contains
+ either `None' or another tuple that contains all the locations
+ that match the expression represented as `gdb.Symtab_and_line'
+ objects (*note Symbol Tables In Python::). If EXPRESSION is
+ provided, it is decoded the way that GDB's inbuilt `break' or
+ `edit' commands do (*note Specify Location::).
+
+ -- Function: gdb.prompt_hook (current_prompt)
+ If PROMPT_HOOK is callable, GDB will call the method assigned to
+ this operation before a prompt is displayed by GDB.
+
+ The parameter `current_prompt' contains the current GDB prompt.
+ This method must return a Python string, or `None'. If a string
+ is returned, the GDB prompt will be set to that string. If `None'
+ is returned, GDB will continue to use the current prompt.
+
+ Some prompts cannot be substituted in GDB. Secondary prompts such
+ as those used by readline for command input, and annotation
+ related prompts are prohibited from being changed.
+
+
+File: gdb.info, Node: Exception Handling, Next: Values From Inferior, Prev: Basic Python, Up: Python API
+
+23.2.2.2 Exception Handling
+...........................
+
+When executing the `python' command, Python exceptions uncaught within
+the Python code are translated to calls to GDB error-reporting
+mechanism. If the command that called `python' does not handle the
+error, GDB will terminate it and print an error message containing the
+Python exception name, the associated value, and the Python call stack
+backtrace at the point where the exception was raised. Example:
+
+ (gdb) python print foo
+ Traceback (most recent call last):
+ File "<string>", line 1, in <module>
+ NameError: name 'foo' is not defined
+
+ GDB errors that happen in GDB commands invoked by Python code are
+converted to Python exceptions. The type of the Python exception
+depends on the error.
+
+`gdb.error'
+ This is the base class for most exceptions generated by GDB. It
+ is derived from `RuntimeError', for compatibility with earlier
+ versions of GDB.
+
+ If an error occurring in GDB does not fit into some more specific
+ category, then the generated exception will have this type.
+
+`gdb.MemoryError'
+ This is a subclass of `gdb.error' which is thrown when an
+ operation tried to access invalid memory in the inferior.
+
+`KeyboardInterrupt'
+ User interrupt (via `C-c' or by typing `q' at a pagination prompt)
+ is translated to a Python `KeyboardInterrupt' exception.
+
+ In all cases, your exception handler will see the GDB error message
+as its value and the Python call stack backtrace at the Python
+statement closest to where the GDB error occured as the traceback.
+
+ When implementing GDB commands in Python via `gdb.Command', it is
+useful to be able to throw an exception that doesn't cause a traceback
+to be printed. For example, the user may have invoked the command
+incorrectly. Use the `gdb.GdbError' exception to handle this case.
+Example:
+
+ (gdb) python
+ >class HelloWorld (gdb.Command):
+ > """Greet the whole world."""
+ > def __init__ (self):
+ > super (HelloWorld, self).__init__ ("hello-world", gdb.COMMAND_OBSCURE)
+ > def invoke (self, args, from_tty):
+ > argv = gdb.string_to_argv (args)
+ > if len (argv) != 0:
+ > raise gdb.GdbError ("hello-world takes no arguments")
+ > print "Hello, World!"
+ >HelloWorld ()
+ >end
+ (gdb) hello-world 42
+ hello-world takes no arguments
+
+
+File: gdb.info, Node: Values From Inferior, Next: Types In Python, Prev: Exception Handling, Up: Python API
+
+23.2.2.3 Values From Inferior
+.............................
+
+GDB provides values it obtains from the inferior program in an object
+of type `gdb.Value'. GDB uses this object for its internal bookkeeping
+of the inferior's values, and for fetching values when necessary.
+
+ Inferior values that are simple scalars can be used directly in
+Python expressions that are valid for the value's data type. Here's an
+example for an integer or floating-point value `some_val':
+
+ bar = some_val + 2
+
+As result of this, `bar' will also be a `gdb.Value' object whose values
+are of the same type as those of `some_val'.
+
+ Inferior values that are structures or instances of some class can
+be accessed using the Python "dictionary syntax". For example, if
+`some_val' is a `gdb.Value' instance holding a structure, you can
+access its `foo' element with:
+
+ bar = some_val['foo']
+
+ Again, `bar' will also be a `gdb.Value' object.
+
+ A `gdb.Value' that represents a function can be executed via
+inferior function call. Any arguments provided to the call must match
+the function's prototype, and must be provided in the order specified
+by that prototype.
+
+ For example, `some_val' is a `gdb.Value' instance representing a
+function that takes two integers as arguments. To execute this
+function, call it like so:
+
+ result = some_val (10,20)
+
+ Any values returned from a function call will be stored as a
+`gdb.Value'.
+
+ The following attributes are provided:
+
+ -- Variable: Value.address
+ If this object is addressable, this read-only attribute holds
+ a `gdb.Value' object representing the address. Otherwise,
+ this attribute holds `None'.
+
+ -- Variable: Value.is_optimized_out
+ This read-only boolean attribute is true if the compiler
+ optimized out this value, thus it is not available for
+ fetching from the inferior.
+
+ -- Variable: Value.type
+ The type of this `gdb.Value'. The value of this attribute is
+ a `gdb.Type' object (*note Types In Python::).
+
+ -- Variable: Value.dynamic_type
+ The dynamic type of this `gdb.Value'. This uses C++ run-time
+ type information (RTTI) to determine the dynamic type of the
+ value. If this value is of class type, it will return the
+ class in which the value is embedded, if any. If this value
+ is of pointer or reference to a class type, it will compute
+ the dynamic type of the referenced object, and return a
+ pointer or reference to that type, respectively. In all
+ other cases, it will return the value's static type.
+
+ Note that this feature will only work when debugging a C++
+ program that includes RTTI for the object in question.
+ Otherwise, it will just return the static type of the value
+ as in `ptype foo' (*note ptype: Symbols.).
+
+ -- Variable: Value.is_lazy
+ The value of this read-only boolean attribute is `True' if
+ this `gdb.Value' has not yet been fetched from the inferior.
+ GDB does not fetch values until necessary, for efficiency.
+ For example:
+
+ myval = gdb.parse_and_eval ('somevar')
+
+ The value of `somevar' is not fetched at this time. It will
+ be fetched when the value is needed, or when the `fetch_lazy'
+ method is invoked.
+
+ The following methods are provided:
+
+ -- Function: Value.__init__ (VAL)
+ Many Python values can be converted directly to a `gdb.Value'
+ via this object initializer. Specifically:
+
+ Python boolean
+ A Python boolean is converted to the boolean type from
+ the current language.
+
+ Python integer
+ A Python integer is converted to the C `long' type for
+ the current architecture.
+
+ Python long
+ A Python long is converted to the C `long long' type for
+ the current architecture.
+
+ Python float
+ A Python float is converted to the C `double' type for
+ the current architecture.
+
+ Python string
+ A Python string is converted to a target string, using
+ the current target encoding.
+
+ `gdb.Value'
+ If `val' is a `gdb.Value', then a copy of the value is
+ made.
+
+ `gdb.LazyString'
+ If `val' is a `gdb.LazyString' (*note Lazy Strings In
+ Python::), then the lazy string's `value' method is
+ called, and its result is used.
+
+ -- Function: Value.cast (type)
+ Return a new instance of `gdb.Value' that is the result of
+ casting this instance to the type described by TYPE, which
+ must be a `gdb.Type' object. If the cast cannot be performed
+ for some reason, this method throws an exception.
+
+ -- Function: Value.dereference ()
+ For pointer data types, this method returns a new `gdb.Value'
+ object whose contents is the object pointed to by the
+ pointer. For example, if `foo' is a C pointer to an `int',
+ declared in your C program as
+
+ int *foo;
+
+ then you can use the corresponding `gdb.Value' to access what
+ `foo' points to like this:
+
+ bar = foo.dereference ()
+
+ The result `bar' will be a `gdb.Value' object holding the
+ value pointed to by `foo'.
+
+ -- Function: Value.dynamic_cast (type)
+ Like `Value.cast', but works as if the C++ `dynamic_cast'
+ operator were used. Consult a C++ reference for details.
+
+ -- Function: Value.reinterpret_cast (type)
+ Like `Value.cast', but works as if the C++ `reinterpret_cast'
+ operator were used. Consult a C++ reference for details.
+
+ -- Function: Value.string ([encoding[, errors[, length]]])
+ If this `gdb.Value' represents a string, then this method
+ converts the contents to a Python string. Otherwise, this
+ method will throw an exception.
+
+ Strings are recognized in a language-specific way; whether a
+ given `gdb.Value' represents a string is determined by the
+ current language.
+
+ For C-like languages, a value is a string if it is a pointer
+ to or an array of characters or ints. The string is assumed
+ to be terminated by a zero of the appropriate width. However
+ if the optional length argument is given, the string will be
+ converted to that given length, ignoring any embedded zeros
+ that the string may contain.
+
+ If the optional ENCODING argument is given, it must be a
+ string naming the encoding of the string in the `gdb.Value',
+ such as `"ascii"', `"iso-8859-6"' or `"utf-8"'. It accepts
+ the same encodings as the corresponding argument to Python's
+ `string.decode' method, and the Python codec machinery will
+ be used to convert the string. If ENCODING is not given, or
+ if ENCODING is the empty string, then either the
+ `target-charset' (*note Character Sets::) will be used, or a
+ language-specific encoding will be used, if the current
+ language is able to supply one.
+
+ The optional ERRORS argument is the same as the corresponding
+ argument to Python's `string.decode' method.
+
+ If the optional LENGTH argument is given, the string will be
+ fetched and converted to the given length.
+
+ -- Function: Value.lazy_string ([encoding [, length]])
+ If this `gdb.Value' represents a string, then this method
+ converts the contents to a `gdb.LazyString' (*note Lazy
+ Strings In Python::). Otherwise, this method will throw an
+ exception.
+
+ If the optional ENCODING argument is given, it must be a
+ string naming the encoding of the `gdb.LazyString'. Some
+ examples are: `ascii', `iso-8859-6' or `utf-8'. If the
+ ENCODING argument is an encoding that GDB does recognize, GDB
+ will raise an error.
+
+ When a lazy string is printed, the GDB encoding machinery is
+ used to convert the string during printing. If the optional
+ ENCODING argument is not provided, or is an empty string, GDB
+ will automatically select the encoding most suitable for the
+ string type. For further information on encoding in GDB
+ please see *Note Character Sets::.
+
+ If the optional LENGTH argument is given, the string will be
+ fetched and encoded to the length of characters specified. If
+ the LENGTH argument is not provided, the string will be
+ fetched and encoded until a null of appropriate width is
+ found.
+
+ -- Function: Value.fetch_lazy ()
+ If the `gdb.Value' object is currently a lazy value
+ (`gdb.Value.is_lazy' is `True'), then the value is fetched
+ from the inferior. Any errors that occur in the process will
+ produce a Python exception.
+
+ If the `gdb.Value' object is not a lazy value, this method
+ has no effect.
+
+ This method does not return a value.
+
+
+
+File: gdb.info, Node: Types In Python, Next: Pretty Printing API, Prev: Values From Inferior, Up: Python API
+
+23.2.2.4 Types In Python
+........................
+
+GDB represents types from the inferior using the class `gdb.Type'.
+
+ The following type-related functions are available in the `gdb'
+module:
+
+ -- Function: gdb.lookup_type (name [, block])
+ This function looks up a type by name. NAME is the name of the
+ type to look up. It must be a string.
+
+ If BLOCK is given, then NAME is looked up in that scope.
+ Otherwise, it is searched for globally.
+
+ Ordinarily, this function will return an instance of `gdb.Type'.
+ If the named type cannot be found, it will throw an exception.
+
+ If the type is a structure or class type, or an enum type, the fields
+of that type can be accessed using the Python "dictionary syntax". For
+example, if `some_type' is a `gdb.Type' instance holding a structure
+type, you can access its `foo' field with:
+
+ bar = some_type['foo']
+
+ `bar' will be a `gdb.Field' object; see below under the description
+of the `Type.fields' method for a description of the `gdb.Field' class.
+
+ An instance of `Type' has the following attributes:
+
+ -- Variable: Type.code
+ The type code for this type. The type code will be one of the
+ `TYPE_CODE_' constants defined below.
+
+ -- Variable: Type.sizeof
+ The size of this type, in target `char' units. Usually, a
+ target's `char' type will be an 8-bit byte. However, on some
+ unusual platforms, this type may have a different size.
+
+ -- Variable: Type.tag
+ The tag name for this type. The tag name is the name after
+ `struct', `union', or `enum' in C and C++; not all languages
+ have this concept. If this type has no tag name, then `None'
+ is returned.
+
+ The following methods are provided:
+
+ -- Function: Type.fields ()
+ For structure and union types, this method returns the
+ fields. Range types have two fields, the minimum and maximum
+ values. Enum types have one field per enum constant.
+ Function and method types have one field per parameter. The
+ base types of C++ classes are also represented as fields. If
+ the type has no fields, or does not fit into one of these
+ categories, an empty sequence will be returned.
+
+ Each field is a `gdb.Field' object, with some pre-defined
+ attributes:
+ `bitpos'
+ This attribute is not available for `static' fields (as
+ in C++ or Java). For non-`static' fields, the value is
+ the bit position of the field. For `enum' fields, the
+ value is the enumeration member's integer representation.
+
+ `name'
+ The name of the field, or `None' for anonymous fields.
+
+ `artificial'
+ This is `True' if the field is artificial, usually
+ meaning that it was provided by the compiler and not the
+ user. This attribute is always provided, and is `False'
+ if the field is not artificial.
+
+ `is_base_class'
+ This is `True' if the field represents a base class of a
+ C++ structure. This attribute is always provided, and
+ is `False' if the field is not a base class of the type
+ that is the argument of `fields', or if that type was
+ not a C++ class.
+
+ `bitsize'
+ If the field is packed, or is a bitfield, then this will
+ have a non-zero value, which is the size of the field in
+ bits. Otherwise, this will be zero; in this case the
+ field's size is given by its type.
+
+ `type'
+ The type of the field. This is usually an instance of
+ `Type', but it can be `None' in some situations.
+
+ -- Function: Type.array (N1 [, N2])
+ Return a new `gdb.Type' object which represents an array of
+ this type. If one argument is given, it is the inclusive
+ upper bound of the array; in this case the lower bound is
+ zero. If two arguments are given, the first argument is the
+ lower bound of the array, and the second argument is the
+ upper bound of the array. An array's length must not be
+ negative, but the bounds can be.
+
+ -- Function: Type.const ()
+ Return a new `gdb.Type' object which represents a
+ `const'-qualified variant of this type.
+
+ -- Function: Type.volatile ()
+ Return a new `gdb.Type' object which represents a
+ `volatile'-qualified variant of this type.
+
+ -- Function: Type.unqualified ()
+ Return a new `gdb.Type' object which represents an unqualified
+ variant of this type. That is, the result is neither `const'
+ nor `volatile'.
+
+ -- Function: Type.range ()
+ Return a Python `Tuple' object that contains two elements: the
+ low bound of the argument type and the high bound of that
+ type. If the type does not have a range, GDB will raise a
+ `gdb.error' exception (*note Exception Handling::).
+
+ -- Function: Type.reference ()
+ Return a new `gdb.Type' object which represents a reference
+ to this type.
+
+ -- Function: Type.pointer ()
+ Return a new `gdb.Type' object which represents a pointer to
+ this type.
+
+ -- Function: Type.strip_typedefs ()
+ Return a new `gdb.Type' that represents the real type, after
+ removing all layers of typedefs.
+
+ -- Function: Type.target ()
+ Return a new `gdb.Type' object which represents the target
+ type of this type.
+
+ For a pointer type, the target type is the type of the
+ pointed-to object. For an array type (meaning C-like
+ arrays), the target type is the type of the elements of the
+ array. For a function or method type, the target type is the
+ type of the return value. For a complex type, the target
+ type is the type of the elements. For a typedef, the target
+ type is the aliased type.
+
+ If the type does not have a target, this method will throw an
+ exception.
+
+ -- Function: Type.template_argument (n [, block])
+ If this `gdb.Type' is an instantiation of a template, this
+ will return a new `gdb.Type' which represents the type of the
+ Nth template argument.
+
+ If this `gdb.Type' is not a template type, this will throw an
+ exception. Ordinarily, only C++ code will have template
+ types.
+
+ If BLOCK is given, then NAME is looked up in that scope.
+ Otherwise, it is searched for globally.
+
+ Each type has a code, which indicates what category this type falls
+into. The available type categories are represented by constants
+defined in the `gdb' module:
+
+`gdb.TYPE_CODE_PTR'
+ The type is a pointer.
+
+`gdb.TYPE_CODE_ARRAY'
+ The type is an array.
+
+`gdb.TYPE_CODE_STRUCT'
+ The type is a structure.
+
+`gdb.TYPE_CODE_UNION'
+ The type is a union.
+
+`gdb.TYPE_CODE_ENUM'
+ The type is an enum.
+
+`gdb.TYPE_CODE_FLAGS'
+ A bit flags type, used for things such as status registers.
+
+`gdb.TYPE_CODE_FUNC'
+ The type is a function.
+
+`gdb.TYPE_CODE_INT'
+ The type is an integer type.
+
+`gdb.TYPE_CODE_FLT'
+ A floating point type.
+
+`gdb.TYPE_CODE_VOID'
+ The special type `void'.
+
+`gdb.TYPE_CODE_SET'
+ A Pascal set type.
+
+`gdb.TYPE_CODE_RANGE'
+ A range type, that is, an integer type with bounds.
+
+`gdb.TYPE_CODE_STRING'
+ A string type. Note that this is only used for certain languages
+ with language-defined string types; C strings are not represented
+ this way.
+
+`gdb.TYPE_CODE_BITSTRING'
+ A string of bits.
+
+`gdb.TYPE_CODE_ERROR'
+ An unknown or erroneous type.
+
+`gdb.TYPE_CODE_METHOD'
+ A method type, as found in C++ or Java.
+
+`gdb.TYPE_CODE_METHODPTR'
+ A pointer-to-member-function.
+
+`gdb.TYPE_CODE_MEMBERPTR'
+ A pointer-to-member.
+
+`gdb.TYPE_CODE_REF'
+ A reference type.
+
+`gdb.TYPE_CODE_CHAR'
+ A character type.
+
+`gdb.TYPE_CODE_BOOL'
+ A boolean type.
+
+`gdb.TYPE_CODE_COMPLEX'
+ A complex float type.
+
+`gdb.TYPE_CODE_TYPEDEF'
+ A typedef to some other type.
+
+`gdb.TYPE_CODE_NAMESPACE'
+ A C++ namespace.
+
+`gdb.TYPE_CODE_DECFLOAT'
+ A decimal floating point type.
+
+`gdb.TYPE_CODE_INTERNAL_FUNCTION'
+ A function internal to GDB. This is the type used to represent
+ convenience functions.
+
+ Further support for types is provided in the `gdb.types' Python
+module (*note gdb.types::).
+
+
+File: gdb.info, Node: Pretty Printing API, Next: Selecting Pretty-Printers, Prev: Types In Python, Up: Python API
+
+23.2.2.5 Pretty Printing API
+............................
+
+An example output is provided (*note Pretty Printing::).
+
+ A pretty-printer is just an object that holds a value and implements
+a specific interface, defined here.
+
+ -- Function: pretty_printer.children (self)
+ GDB will call this method on a pretty-printer to compute the
+ children of the pretty-printer's value.
+
+ This method must return an object conforming to the Python iterator
+ protocol. Each item returned by the iterator must be a tuple
+ holding two elements. The first element is the "name" of the
+ child; the second element is the child's value. The value can be
+ any Python object which is convertible to a GDB value.
+
+ This method is optional. If it does not exist, GDB will act as
+ though the value has no children.
+
+ -- Function: pretty_printer.display_hint (self)
+ The CLI may call this method and use its result to change the
+ formatting of a value. The result will also be supplied to an MI
+ consumer as a `displayhint' attribute of the variable being
+ printed.
+
+ This method is optional. If it does exist, this method must
+ return a string.
+
+ Some display hints are predefined by GDB:
+
+ `array'
+ Indicate that the object being printed is "array-like". The
+ CLI uses this to respect parameters such as `set print
+ elements' and `set print array'.
+
+ `map'
+ Indicate that the object being printed is "map-like", and
+ that the children of this value can be assumed to alternate
+ between keys and values.
+
+ `string'
+ Indicate that the object being printed is "string-like". If
+ the printer's `to_string' method returns a Python string of
+ some kind, then GDB will call its internal language-specific
+ string-printing function to format the string. For the CLI
+ this means adding quotation marks, possibly escaping some
+ characters, respecting `set print elements', and the like.
+
+ -- Function: pretty_printer.to_string (self)
+ GDB will call this method to display the string representation of
+ the value passed to the object's constructor.
+
+ When printing from the CLI, if the `to_string' method exists, then
+ GDB will prepend its result to the values returned by `children'.
+ Exactly how this formatting is done is dependent on the display
+ hint, and may change as more hints are added. Also, depending on
+ the print settings (*note Print Settings::), the CLI may print
+ just the result of `to_string' in a stack trace, omitting the
+ result of `children'.
+
+ If this method returns a string, it is printed verbatim.
+
+ Otherwise, if this method returns an instance of `gdb.Value', then
+ GDB prints this value. This may result in a call to another
+ pretty-printer.
+
+ If instead the method returns a Python value which is convertible
+ to a `gdb.Value', then GDB performs the conversion and prints the
+ resulting value. Again, this may result in a call to another
+ pretty-printer. Python scalars (integers, floats, and booleans)
+ and strings are convertible to `gdb.Value'; other types are not.
+
+ Finally, if this method returns `None' then no further operations
+ are peformed in this method and nothing is printed.
+
+ If the result is not one of these types, an exception is raised.
+
+ GDB provides a function which can be used to look up the default
+pretty-printer for a `gdb.Value':
+
+ -- Function: gdb.default_visualizer (value)
+ This function takes a `gdb.Value' object as an argument. If a
+ pretty-printer for this value exists, then it is returned. If no
+ such printer exists, then this returns `None'.
+
+
+File: gdb.info, Node: Selecting Pretty-Printers, Next: Writing a Pretty-Printer, Prev: Pretty Printing API, Up: Python API
+
+23.2.2.6 Selecting Pretty-Printers
+..................................
+
+The Python list `gdb.pretty_printers' contains an array of functions or
+callable objects that have been registered via addition as a
+pretty-printer. Printers in this list are called `global' printers,
+they're available when debugging all inferiors. Each `gdb.Progspace'
+contains a `pretty_printers' attribute. Each `gdb.Objfile' also
+contains a `pretty_printers' attribute.
+
+ Each function on these lists is passed a single `gdb.Value' argument
+and should return a pretty-printer object conforming to the interface
+definition above (*note Pretty Printing API::). If a function cannot
+create a pretty-printer for the value, it should return `None'.
+
+ GDB first checks the `pretty_printers' attribute of each
+`gdb.Objfile' in the current program space and iteratively calls each
+enabled lookup routine in the list for that `gdb.Objfile' until it
+receives a pretty-printer object. If no pretty-printer is found in the
+objfile lists, GDB then searches the pretty-printer list of the current
+program space, calling each enabled function until an object is
+returned. After these lists have been exhausted, it tries the global
+`gdb.pretty_printers' list, again calling each enabled function until an
+object is returned.
+
+ The order in which the objfiles are searched is not specified. For a
+given list, functions are always invoked from the head of the list, and
+iterated over sequentially until the end of the list, or a printer
+object is returned.
+
+ For various reasons a pretty-printer may not work. For example, the
+underlying data structure may have changed and the pretty-printer is
+out of date.
+
+ The consequences of a broken pretty-printer are severe enough that
+GDB provides support for enabling and disabling individual printers.
+For example, if `print frame-arguments' is on, a backtrace can become
+highly illegible if any argument is printed with a broken printer.
+
+ Pretty-printers are enabled and disabled by attaching an `enabled'
+attribute to the registered function or callable object. If this
+attribute is present and its value is `False', the printer is disabled,
+otherwise the printer is enabled.
+
+
+File: gdb.info, Node: Writing a Pretty-Printer, Next: Inferiors In Python, Prev: Selecting Pretty-Printers, Up: Python API
+
+23.2.2.7 Writing a Pretty-Printer
+.................................
+
+A pretty-printer consists of two parts: a lookup function to detect if
+the type is supported, and the printer itself.
+
+ Here is an example showing how a `std::string' printer might be
+written. *Note Pretty Printing API::, for details on the API this class
+must provide.
+
+ class StdStringPrinter(object):
+ "Print a std::string"
+
+ def __init__(self, val):
+ self.val = val
+
+ def to_string(self):
+ return self.val['_M_dataplus']['_M_p']
+
+ def display_hint(self):
+ return 'string'
+
+ And here is an example showing how a lookup function for the printer
+example above might be written.
+
+ def str_lookup_function(val):
+ lookup_tag = val.type.tag
+ if lookup_tag == None:
+ return None
+ regex = re.compile("^std::basic_string<char,.*>$")
+ if regex.match(lookup_tag):
+ return StdStringPrinter(val)
+ return None
+
+ The example lookup function extracts the value's type, and attempts
+to match it to a type that it can pretty-print. If it is a type the
+printer can pretty-print, it will return a printer object. If not, it
+returns `None'.
+
+ We recommend that you put your core pretty-printers into a Python
+package. If your pretty-printers are for use with a library, we
+further recommend embedding a version number into the package name.
+This practice will enable GDB to load multiple versions of your
+pretty-printers at the same time, because they will have different
+names.
+
+ You should write auto-loaded code (*note Auto-loading::) such that it
+can be evaluated multiple times without changing its meaning. An ideal
+auto-load file will consist solely of `import's of your printer
+modules, followed by a call to a register pretty-printers with the
+current objfile.
+
+ Taken as a whole, this approach will scale nicely to multiple
+inferiors, each potentially using a different library version.
+Embedding a version number in the Python package name will ensure that
+GDB is able to load both sets of printers simultaneously. Then,
+because the search for pretty-printers is done by objfile, and because
+your auto-loaded code took care to register your library's printers
+with a specific objfile, GDB will find the correct printers for the
+specific version of the library used by each inferior.
+
+ To continue the `std::string' example (*note Pretty Printing API::),
+this code might appear in `gdb.libstdcxx.v6':
+
+ def register_printers(objfile):
+ objfile.pretty_printers.append(str_lookup_function)
+
+And then the corresponding contents of the auto-load file would be:
+
+ import gdb.libstdcxx.v6
+ gdb.libstdcxx.v6.register_printers(gdb.current_objfile())
+
+ The previous example illustrates a basic pretty-printer. There are
+a few things that can be improved on. The printer doesn't have a name,
+making it hard to identify in a list of installed printers. The lookup
+function has a name, but lookup functions can have arbitrary, even
+identical, names.
+
+ Second, the printer only handles one type, whereas a library
+typically has several types. One could install a lookup function for
+each desired type in the library, but one could also have a single
+lookup function recognize several types. The latter is the
+conventional way this is handled. If a pretty-printer can handle
+multiple data types, then its "subprinters" are the printers for the
+individual data types.
+
+ The `gdb.printing' module provides a formal way of solving these
+problems (*note gdb.printing::). Here is another example that handles
+multiple types.
+
+ These are the types we are going to pretty-print:
+
+ struct foo { int a, b; };
+ struct bar { struct foo x, y; };
+
+ Here are the printers:
+
+ class fooPrinter:
+ """Print a foo object."""
+
+ def __init__(self, val):
+ self.val = val
+
+ def to_string(self):
+ return ("a=<" + str(self.val["a"]) +
+ "> b=<" + str(self.val["b"]) + ">")
+
+ class barPrinter:
+ """Print a bar object."""
+
+ def __init__(self, val):
+ self.val = val
+
+ def to_string(self):
+ return ("x=<" + str(self.val["x"]) +
+ "> y=<" + str(self.val["y"]) + ">")
+
+ This example doesn't need a lookup function, that is handled by the
+`gdb.printing' module. Instead a function is provided to build up the
+object that handles the lookup.
+
+ import gdb.printing
+
+ def build_pretty_printer():
+ pp = gdb.printing.RegexpCollectionPrettyPrinter(
+ "my_library")
+ pp.add_printer('foo', '^foo$', fooPrinter)
+ pp.add_printer('bar', '^bar$', barPrinter)
+ return pp
+
+ And here is the autoload support:
+
+ import gdb.printing
+ import my_library
+ gdb.printing.register_pretty_printer(
+ gdb.current_objfile(),
+ my_library.build_pretty_printer())
+
+ Finally, when this printer is loaded into GDB, here is the
+corresponding output of `info pretty-printer':
+
+ (gdb) info pretty-printer
+ my_library.so:
+ my_library
+ foo
+ bar
+
+
+File: gdb.info, Node: Inferiors In Python, Next: Events In Python, Prev: Writing a Pretty-Printer, Up: Python API
+
+23.2.2.8 Inferiors In Python
+............................
+
+Programs which are being run under GDB are called inferiors (*note
+Inferiors and Programs::). Python scripts can access information about
+and manipulate inferiors controlled by GDB via objects of the
+`gdb.Inferior' class.
+
+ The following inferior-related functions are available in the `gdb'
+module:
+
+ -- Function: gdb.inferiors ()
+ Return a tuple containing all inferior objects.
+
+ -- Function: gdb.selected_inferior ()
+ Return an object representing the current inferior.
+
+ A `gdb.Inferior' object has the following attributes:
+
+ -- Variable: Inferior.num
+ ID of inferior, as assigned by GDB.
+
+ -- Variable: Inferior.pid
+ Process ID of the inferior, as assigned by the underlying
+ operating system.
+
+ -- Variable: Inferior.was_attached
+ Boolean signaling whether the inferior was created using
+ `attach', or started by GDB itself.
+
+ A `gdb.Inferior' object has the following methods:
+
+ -- Function: Inferior.is_valid ()
+ Returns `True' if the `gdb.Inferior' object is valid, `False'
+ if not. A `gdb.Inferior' object will become invalid if the
+ inferior no longer exists within GDB. All other
+ `gdb.Inferior' methods will throw an exception if it is
+ invalid at the time the method is called.
+
+ -- Function: Inferior.threads ()
+ This method returns a tuple holding all the threads which are
+ valid when it is called. If there are no valid threads, the
+ method will return an empty tuple.
+
+ -- Function: Inferior.read_memory (address, length)
+ Read LENGTH bytes of memory from the inferior, starting at
+ ADDRESS. Returns a buffer object, which behaves much like an
+ array or a string. It can be modified and given to the
+ `gdb.write_memory' function.
+
+ -- Function: Inferior.write_memory (address, buffer [, length])
+ Write the contents of BUFFER to the inferior, starting at
+ ADDRESS. The BUFFER parameter must be a Python object which
+ supports the buffer protocol, i.e., a string, an array or the
+ object returned from `gdb.read_memory'. If given, LENGTH
+ determines the number of bytes from BUFFER to be written.
+
+ -- Function: Inferior.search_memory (address, length, pattern)
+ Search a region of the inferior memory starting at ADDRESS
+ with the given LENGTH using the search pattern supplied in
+ PATTERN. The PATTERN parameter must be a Python object which
+ supports the buffer protocol, i.e., a string, an array or the
+ object returned from `gdb.read_memory'. Returns a Python
+ `Long' containing the address where the pattern was found, or
+ `None' if the pattern could not be found.
+
+
+File: gdb.info, Node: Events In Python, Next: Threads In Python, Prev: Inferiors In Python, Up: Python API
+
+23.2.2.9 Events In Python
+.........................
+
+GDB provides a general event facility so that Python code can be
+notified of various state changes, particularly changes that occur in
+the inferior.
+
+ An "event" is just an object that describes some state change. The
+type of the object and its attributes will vary depending on the details
+of the change. All the existing events are described below.
+
+ In order to be notified of an event, you must register an event
+handler with an "event registry". An event registry is an object in the
+`gdb.events' module which dispatches particular events. A registry
+provides methods to register and unregister event handlers:
+
+ -- Function: EventRegistry.connect (object)
+ Add the given callable OBJECT to the registry. This object
+ will be called when an event corresponding to this registry
+ occurs.
+
+ -- Function: EventRegistry.disconnect (object)
+ Remove the given OBJECT from the registry. Once removed, the
+ object will no longer receive notifications of events.
+
+ Here is an example:
+
+ def exit_handler (event):
+ print "event type: exit"
+ print "exit code: %d" % (event.exit_code)
+
+ gdb.events.exited.connect (exit_handler)
+
+ In the above example we connect our handler `exit_handler' to the
+registry `events.exited'. Once connected, `exit_handler' gets called
+when the inferior exits. The argument "event" in this example is of
+type `gdb.ExitedEvent'. As you can see in the example the
+`ExitedEvent' object has an attribute which indicates the exit code of
+the inferior.
+
+ The following is a listing of the event registries that are
+available and details of the events they emit:
+
+`events.cont'
+ Emits `gdb.ThreadEvent'.
+
+ Some events can be thread specific when GDB is running in non-stop
+ mode. When represented in Python, these events all extend
+ `gdb.ThreadEvent'. Note, this event is not emitted directly;
+ instead, events which are emitted by this or other modules might
+ extend this event. Examples of these events are
+ `gdb.BreakpointEvent' and `gdb.ContinueEvent'.
+
+ -- Variable: ThreadEvent.inferior_thread
+ In non-stop mode this attribute will be set to the
+ specific thread which was involved in the emitted event.
+ Otherwise, it will be set to `None'.
+
+ Emits `gdb.ContinueEvent' which extends `gdb.ThreadEvent'.
+
+ This event indicates that the inferior has been continued after a
+ stop. For inherited attribute refer to `gdb.ThreadEvent' above.
+
+`events.exited'
+ Emits `events.ExitedEvent' which indicates that the inferior has
+ exited. `events.ExitedEvent' has two attributes:
+ -- Variable: ExitedEvent.exit_code
+ An integer representing the exit code, if available,
+ which the inferior has returned. (The exit code could
+ be unavailable if, for example, GDB detaches from the
+ inferior.) If the exit code is unavailable, the
+ attribute does not exist.
+
+ -- Variable: ExitedEvent inferior
+ A reference to the inferior which triggered the `exited'
+ event.
+
+`events.stop'
+ Emits `gdb.StopEvent' which extends `gdb.ThreadEvent'.
+
+ Indicates that the inferior has stopped. All events emitted by
+ this registry extend StopEvent. As a child of `gdb.ThreadEvent',
+ `gdb.StopEvent' will indicate the stopped thread when GDB is
+ running in non-stop mode. Refer to `gdb.ThreadEvent' above for
+ more details.
+
+ Emits `gdb.SignalEvent' which extends `gdb.StopEvent'.
+
+ This event indicates that the inferior or one of its threads has
+ received as signal. `gdb.SignalEvent' has the following
+ attributes:
+
+ -- Variable: SignalEvent.stop_signal
+ A string representing the signal received by the
+ inferior. A list of possible signal values can be
+ obtained by running the command `info signals' in the
+ GDB command prompt.
+
+ Also emits `gdb.BreakpointEvent' which extends `gdb.StopEvent'.
+
+ `gdb.BreakpointEvent' event indicates that one or more breakpoints
+ have been hit, and has the following attributes:
+
+ -- Variable: BreakpointEvent.breakpoints
+ A sequence containing references to all the breakpoints
+ (type `gdb.Breakpoint') that were hit. *Note
+ Breakpoints In Python::, for details of the
+ `gdb.Breakpoint' object.
+
+ -- Variable: BreakpointEvent.breakpoint
+ A reference to the first breakpoint that was hit. This
+ function is maintained for backward compatibility and is
+ now deprecated in favor of the
+ `gdb.BreakpointEvent.breakpoints' attribute.
+
+`events.new_objfile'
+ Emits `gdb.NewObjFileEvent' which indicates that a new object file
+ has been loaded by GDB. `gdb.NewObjFileEvent' has one attribute:
+
+ -- Variable: NewObjFileEvent.new_objfile
+ A reference to the object file (`gdb.Objfile') which has
+ been loaded. *Note Objfiles In Python::, for details of
+ the `gdb.Objfile' object.
+
+
+
+File: gdb.info, Node: Threads In Python, Next: Commands In Python, Prev: Events In Python, Up: Python API
+
+23.2.2.10 Threads In Python
+...........................
+
+Python scripts can access information about, and manipulate inferior
+threads controlled by GDB, via objects of the `gdb.InferiorThread'
+class.
+
+ The following thread-related functions are available in the `gdb'
+module:
+
+ -- Function: gdb.selected_thread ()
+ This function returns the thread object for the selected thread.
+ If there is no selected thread, this will return `None'.
+
+ A `gdb.InferiorThread' object has the following attributes:
+
+ -- Variable: InferiorThread.name
+ The name of the thread. If the user specified a name using
+ `thread name', then this returns that name. Otherwise, if an
+ OS-supplied name is available, then it is returned.
+ Otherwise, this returns `None'.
+
+ This attribute can be assigned to. The new value must be a
+ string object, which sets the new name, or `None', which
+ removes any user-specified thread name.
+
+ -- Variable: InferiorThread.num
+ ID of the thread, as assigned by GDB.
+
+ -- Variable: InferiorThread.ptid
+ ID of the thread, as assigned by the operating system. This
+ attribute is a tuple containing three integers. The first is
+ the Process ID (PID); the second is the Lightweight Process
+ ID (LWPID), and the third is the Thread ID (TID). Either the
+ LWPID or TID may be 0, which indicates that the operating
+ system does not use that identifier.
+
+ A `gdb.InferiorThread' object has the following methods:
+
+ -- Function: InferiorThread.is_valid ()
+ Returns `True' if the `gdb.InferiorThread' object is valid,
+ `False' if not. A `gdb.InferiorThread' object will become
+ invalid if the thread exits, or the inferior that the thread
+ belongs is deleted. All other `gdb.InferiorThread' methods
+ will throw an exception if it is invalid at the time the
+ method is called.
+
+ -- Function: InferiorThread.switch ()
+ This changes GDB's currently selected thread to the one
+ represented by this object.
+
+ -- Function: InferiorThread.is_stopped ()
+ Return a Boolean indicating whether the thread is stopped.
+
+ -- Function: InferiorThread.is_running ()
+ Return a Boolean indicating whether the thread is running.
+
+ -- Function: InferiorThread.is_exited ()
+ Return a Boolean indicating whether the thread is exited.
+
+
+File: gdb.info, Node: Commands In Python, Next: Parameters In Python, Prev: Threads In Python, Up: Python API
+
+23.2.2.11 Commands In Python
+............................
+
+You can implement new GDB CLI commands in Python. A CLI command is
+implemented using an instance of the `gdb.Command' class, most commonly
+using a subclass.
+
+ -- Function: Command.__init__ (name, COMMAND_CLASS [, COMPLETER_CLASS
+ [, PREFIX]])
+ The object initializer for `Command' registers the new command
+ with GDB. This initializer is normally invoked from the subclass'
+ own `__init__' method.
+
+ NAME is the name of the command. If NAME consists of multiple
+ words, then the initial words are looked for as prefix commands.
+ In this case, if one of the prefix commands does not exist, an
+ exception is raised.
+
+ There is no support for multi-line commands.
+
+ COMMAND_CLASS should be one of the `COMMAND_' constants defined
+ below. This argument tells GDB how to categorize the new command
+ in the help system.
+
+ COMPLETER_CLASS is an optional argument. If given, it should be
+ one of the `COMPLETE_' constants defined below. This argument
+ tells GDB how to perform completion for this command. If not
+ given, GDB will attempt to complete using the object's `complete'
+ method (see below); if no such method is found, an error will
+ occur when completion is attempted.
+
+ PREFIX is an optional argument. If `True', then the new command
+ is a prefix command; sub-commands of this command may be
+ registered.
+
+ The help text for the new command is taken from the Python
+ documentation string for the command's class, if there is one. If
+ no documentation string is provided, the default value "This
+ command is not documented." is used.
+
+ -- Function: Command.dont_repeat ()
+ By default, a GDB command is repeated when the user enters a blank
+ line at the command prompt. A command can suppress this behavior
+ by invoking the `dont_repeat' method. This is similar to the user
+ command `dont-repeat', see *Note dont-repeat: Define.
+
+ -- Function: Command.invoke (argument, from_tty)
+ This method is called by GDB when this command is invoked.
+
+ ARGUMENT is a string. It is the argument to the command, after
+ leading and trailing whitespace has been stripped.
+
+ FROM_TTY is a boolean argument. When true, this means that the
+ command was entered by the user at the terminal; when false it
+ means that the command came from elsewhere.
+
+ If this method throws an exception, it is turned into a GDB
+ `error' call. Otherwise, the return value is ignored.
+
+ To break ARGUMENT up into an argv-like string use
+ `gdb.string_to_argv'. This function behaves identically to GDB's
+ internal argument lexer `buildargv'. It is recommended to use
+ this for consistency. Arguments are separated by spaces and may
+ be quoted. Example:
+
+ print gdb.string_to_argv ("1 2\ \\\"3 '4 \"5' \"6 '7\"")
+ ['1', '2 "3', '4 "5', "6 '7"]
+
+
+ -- Function: Command.complete (text, word)
+ This method is called by GDB when the user attempts completion on
+ this command. All forms of completion are handled by this method,
+ that is, the <TAB> and <M-?> key bindings (*note Completion::),
+ and the `complete' command (*note complete: Help.).
+
+ The arguments TEXT and WORD are both strings. TEXT holds the
+ complete command line up to the cursor's location. WORD holds the
+ last word of the command line; this is computed using a
+ word-breaking heuristic.
+
+ The `complete' method can return several values:
+ * If the return value is a sequence, the contents of the
+ sequence are used as the completions. It is up to `complete'
+ to ensure that the contents actually do complete the word. A
+ zero-length sequence is allowed, it means that there were no
+ completions available. Only string elements of the sequence
+ are used; other elements in the sequence are ignored.
+
+ * If the return value is one of the `COMPLETE_' constants
+ defined below, then the corresponding GDB-internal completion
+ function is invoked, and its result is used.
+
+ * All other results are treated as though there were no
+ available completions.
+
+ When a new command is registered, it must be declared as a member of
+some general class of commands. This is used to classify top-level
+commands in the on-line help system; note that prefix commands are not
+listed under their own category but rather that of their top-level
+command. The available classifications are represented by constants
+defined in the `gdb' module:
+
+`gdb.COMMAND_NONE'
+ The command does not belong to any particular class. A command in
+ this category will not be displayed in any of the help categories.
+
+`gdb.COMMAND_RUNNING'
+ The command is related to running the inferior. For example,
+ `start', `step', and `continue' are in this category. Type `help
+ running' at the GDB prompt to see a list of commands in this
+ category.
+
+`gdb.COMMAND_DATA'
+ The command is related to data or variables. For example, `call',
+ `find', and `print' are in this category. Type `help data' at the
+ GDB prompt to see a list of commands in this category.
+
+`gdb.COMMAND_STACK'
+ The command has to do with manipulation of the stack. For example,
+ `backtrace', `frame', and `return' are in this category. Type
+ `help stack' at the GDB prompt to see a list of commands in this
+ category.
+
+`gdb.COMMAND_FILES'
+ This class is used for file-related commands. For example,
+ `file', `list' and `section' are in this category. Type `help
+ files' at the GDB prompt to see a list of commands in this
+ category.
+
+`gdb.COMMAND_SUPPORT'
+ This should be used for "support facilities", generally meaning
+ things that are useful to the user when interacting with GDB, but
+ not related to the state of the inferior. For example, `help',
+ `make', and `shell' are in this category. Type `help support' at
+ the GDB prompt to see a list of commands in this category.
+
+`gdb.COMMAND_STATUS'
+ The command is an `info'-related command, that is, related to the
+ state of GDB itself. For example, `info', `macro', and `show' are
+ in this category. Type `help status' at the GDB prompt to see a
+ list of commands in this category.
+
+`gdb.COMMAND_BREAKPOINTS'
+ The command has to do with breakpoints. For example, `break',
+ `clear', and `delete' are in this category. Type `help
+ breakpoints' at the GDB prompt to see a list of commands in this
+ category.
+
+`gdb.COMMAND_TRACEPOINTS'
+ The command has to do with tracepoints. For example, `trace',
+ `actions', and `tfind' are in this category. Type `help
+ tracepoints' at the GDB prompt to see a list of commands in this
+ category.
+
+`gdb.COMMAND_OBSCURE'
+ The command is only used in unusual circumstances, or is not of
+ general interest to users. For example, `checkpoint', `fork', and
+ `stop' are in this category. Type `help obscure' at the GDB
+ prompt to see a list of commands in this category.
+
+`gdb.COMMAND_MAINTENANCE'
+ The command is only useful to GDB maintainers. The `maintenance'
+ and `flushregs' commands are in this category. Type `help
+ internals' at the GDB prompt to see a list of commands in this
+ category.
+
+ A new command can use a predefined completion function, either by
+specifying it via an argument at initialization, or by returning it
+from the `complete' method. These predefined completion constants are
+all defined in the `gdb' module:
+
+`gdb.COMPLETE_NONE'
+ This constant means that no completion should be done.
+
+`gdb.COMPLETE_FILENAME'
+ This constant means that filename completion should be performed.
+
+`gdb.COMPLETE_LOCATION'
+ This constant means that location completion should be done.
+ *Note Specify Location::.
+
+`gdb.COMPLETE_COMMAND'
+ This constant means that completion should examine GDB command
+ names.
+
+`gdb.COMPLETE_SYMBOL'
+ This constant means that completion should be done using symbol
+ names as the source.
+
+ The following code snippet shows how a trivial CLI command can be
+implemented in Python:
+
+ class HelloWorld (gdb.Command):
+ """Greet the whole world."""
+
+ def __init__ (self):
+ super (HelloWorld, self).__init__ ("hello-world", gdb.COMMAND_OBSCURE)
+
+ def invoke (self, arg, from_tty):
+ print "Hello, World!"
+
+ HelloWorld ()
+
+ The last line instantiates the class, and is necessary to trigger the
+registration of the command with GDB. Depending on how the Python code
+is read into GDB, you may need to import the `gdb' module explicitly.
+
+
+File: gdb.info, Node: Parameters In Python, Next: Functions In Python, Prev: Commands In Python, Up: Python API
+
+23.2.2.12 Parameters In Python
+..............................
+
+You can implement new GDB parameters using Python. A new parameter is
+implemented as an instance of the `gdb.Parameter' class.
+
+ Parameters are exposed to the user via the `set' and `show'
+commands. *Note Help::.
+
+ There are many parameters that already exist and can be set in GDB.
+Two examples are: `set follow fork' and `set charset'. Setting these
+parameters influences certain behavior in GDB. Similarly, you can
+define parameters that can be used to influence behavior in custom
+Python scripts and commands.
+
+ -- Function: Parameter.__init__ (name, COMMAND-CLASS, PARAMETER-CLASS
+ [, ENUM-SEQUENCE])
+ The object initializer for `Parameter' registers the new parameter
+ with GDB. This initializer is normally invoked from the subclass'
+ own `__init__' method.
+
+ NAME is the name of the new parameter. If NAME consists of
+ multiple words, then the initial words are looked for as prefix
+ parameters. An example of this can be illustrated with the `set
+ print' set of parameters. If NAME is `print foo', then `print'
+ will be searched as the prefix parameter. In this case the
+ parameter can subsequently be accessed in GDB as `set print foo'.
+
+ If NAME consists of multiple words, and no prefix parameter group
+ can be found, an exception is raised.
+
+ COMMAND-CLASS should be one of the `COMMAND_' constants (*note
+ Commands In Python::). This argument tells GDB how to categorize
+ the new parameter in the help system.
+
+ PARAMETER-CLASS should be one of the `PARAM_' constants defined
+ below. This argument tells GDB the type of the new parameter;
+ this information is used for input validation and completion.
+
+ If PARAMETER-CLASS is `PARAM_ENUM', then ENUM-SEQUENCE must be a
+ sequence of strings. These strings represent the possible values
+ for the parameter.
+
+ If PARAMETER-CLASS is not `PARAM_ENUM', then the presence of a
+ fourth argument will cause an exception to be thrown.
+
+ The help text for the new parameter is taken from the Python
+ documentation string for the parameter's class, if there is one.
+ If there is no documentation string, a default value is used.
+
+ -- Variable: Parameter.set_doc
+ If this attribute exists, and is a string, then its value is used
+ as the help text for this parameter's `set' command. The value is
+ examined when `Parameter.__init__' is invoked; subsequent changes
+ have no effect.
+
+ -- Variable: Parameter.show_doc
+ If this attribute exists, and is a string, then its value is used
+ as the help text for this parameter's `show' command. The value is
+ examined when `Parameter.__init__' is invoked; subsequent changes
+ have no effect.
+
+ -- Variable: Parameter.value
+ The `value' attribute holds the underlying value of the parameter.
+ It can be read and assigned to just as any other attribute. GDB
+ does validation when assignments are made.
+
+ There are two methods that should be implemented in any `Parameter'
+class. These are:
+
+ -- Function: Parameter.get_set_string (self)
+ GDB will call this method when a PARAMETER's value has been
+ changed via the `set' API (for example, `set foo off'). The
+ `value' attribute has already been populated with the new value
+ and may be used in output. This method must return a string.
+
+ -- Function: Parameter.get_show_string (self, svalue)
+ GDB will call this method when a PARAMETER's `show' API has been
+ invoked (for example, `show foo'). The argument `svalue' receives
+ the string representation of the current value. This method must
+ return a string.
+
+ When a new parameter is defined, its type must be specified. The
+available types are represented by constants defined in the `gdb'
+module:
+
+`gdb.PARAM_BOOLEAN'
+ The value is a plain boolean. The Python boolean values, `True'
+ and `False' are the only valid values.
+
+`gdb.PARAM_AUTO_BOOLEAN'
+ The value has three possible states: true, false, and `auto'. In
+ Python, true and false are represented using boolean constants, and
+ `auto' is represented using `None'.
+
+`gdb.PARAM_UINTEGER'
+ The value is an unsigned integer. The value of 0 should be
+ interpreted to mean "unlimited".
+
+`gdb.PARAM_INTEGER'
+ The value is a signed integer. The value of 0 should be
+ interpreted to mean "unlimited".
+
+`gdb.PARAM_STRING'
+ The value is a string. When the user modifies the string, any
+ escape sequences, such as `\t', `\f', and octal escapes, are
+ translated into corresponding characters and encoded into the
+ current host charset.
+
+`gdb.PARAM_STRING_NOESCAPE'
+ The value is a string. When the user modifies the string, escapes
+ are passed through untranslated.
+
+`gdb.PARAM_OPTIONAL_FILENAME'
+ The value is a either a filename (a string), or `None'.
+
+`gdb.PARAM_FILENAME'
+ The value is a filename. This is just like
+ `PARAM_STRING_NOESCAPE', but uses file names for completion.
+
+`gdb.PARAM_ZINTEGER'
+ The value is an integer. This is like `PARAM_INTEGER', except 0
+ is interpreted as itself.
+
+`gdb.PARAM_ENUM'
+ The value is a string, which must be one of a collection string
+ constants provided when the parameter is created.
+
+
+File: gdb.info, Node: Functions In Python, Next: Progspaces In Python, Prev: Parameters In Python, Up: Python API
+
+23.2.2.13 Writing new convenience functions
+...........................................
+
+You can implement new convenience functions (*note Convenience Vars::)
+in Python. A convenience function is an instance of a subclass of the
+class `gdb.Function'.
+
+ -- Function: Function.__init__ (name)
+ The initializer for `Function' registers the new function with
+ GDB. The argument NAME is the name of the function, a string.
+ The function will be visible to the user as a convenience variable
+ of type `internal function', whose name is the same as the given
+ NAME.
+
+ The documentation for the new function is taken from the
+ documentation string for the new class.
+
+ -- Function: Function.invoke (*ARGS)
+ When a convenience function is evaluated, its arguments are
+ converted to instances of `gdb.Value', and then the function's
+ `invoke' method is called. Note that GDB does not predetermine
+ the arity of convenience functions. Instead, all available
+ arguments are passed to `invoke', following the standard Python
+ calling convention. In particular, a convenience function can
+ have default values for parameters without ill effect.
+
+ The return value of this method is used as its value in the
+ enclosing expression. If an ordinary Python value is returned, it
+ is converted to a `gdb.Value' following the usual rules.
+
+ The following code snippet shows how a trivial convenience function
+can be implemented in Python:
+
+ class Greet (gdb.Function):
+ """Return string to greet someone.
+ Takes a name as argument."""
+
+ def __init__ (self):
+ super (Greet, self).__init__ ("greet")
+
+ def invoke (self, name):
+ return "Hello, %s!" % name.string ()
+
+ Greet ()
+
+ The last line instantiates the class, and is necessary to trigger the
+registration of the function with GDB. Depending on how the Python
+code is read into GDB, you may need to import the `gdb' module
+explicitly.
+
+
+File: gdb.info, Node: Progspaces In Python, Next: Objfiles In Python, Prev: Functions In Python, Up: Python API
+
+23.2.2.14 Program Spaces In Python
+..................................
+
+A program space, or "progspace", represents a symbolic view of an
+address space. It consists of all of the objfiles of the program.
+*Note Objfiles In Python::. *Note program spaces: Inferiors and
+Programs, for more details about program spaces.
+
+ The following progspace-related functions are available in the `gdb'
+module:
+
+ -- Function: gdb.current_progspace ()
+ This function returns the program space of the currently selected
+ inferior. *Note Inferiors and Programs::.
+
+ -- Function: gdb.progspaces ()
+ Return a sequence of all the progspaces currently known to GDB.
+
+ Each progspace is represented by an instance of the `gdb.Progspace'
+class.
+
+ -- Variable: Progspace.filename
+ The file name of the progspace as a string.
+
+ -- Variable: Progspace.pretty_printers
+ The `pretty_printers' attribute is a list of functions. It is
+ used to look up pretty-printers. A `Value' is passed to each
+ function in order; if the function returns `None', then the search
+ continues. Otherwise, the return value should be an object which
+ is used to format the value. *Note Pretty Printing API::, for more
+ information.
+
+
+File: gdb.info, Node: Objfiles In Python, Next: Frames In Python, Prev: Progspaces In Python, Up: Python API
+
+23.2.2.15 Objfiles In Python
+............................
+
+GDB loads symbols for an inferior from various symbol-containing files
+(*note Files::). These include the primary executable file, any shared
+libraries used by the inferior, and any separate debug info files
+(*note Separate Debug Files::). GDB calls these symbol-containing
+files "objfiles".
+
+ The following objfile-related functions are available in the `gdb'
+module:
+
+ -- Function: gdb.current_objfile ()
+ When auto-loading a Python script (*note Auto-loading::), GDB sets
+ the "current objfile" to the corresponding objfile. This function
+ returns the current objfile. If there is no current objfile, this
+ function returns `None'.
+
+ -- Function: gdb.objfiles ()
+ Return a sequence of all the objfiles current known to GDB. *Note
+ Objfiles In Python::.
+
+ Each objfile is represented by an instance of the `gdb.Objfile'
+class.
+
+ -- Variable: Objfile.filename
+ The file name of the objfile as a string.
+
+ -- Variable: Objfile.pretty_printers
+ The `pretty_printers' attribute is a list of functions. It is
+ used to look up pretty-printers. A `Value' is passed to each
+ function in order; if the function returns `None', then the search
+ continues. Otherwise, the return value should be an object which
+ is used to format the value. *Note Pretty Printing API::, for more
+ information.
+
+ A `gdb.Objfile' object has the following methods:
+
+ -- Function: Objfile.is_valid ()
+ Returns `True' if the `gdb.Objfile' object is valid, `False' if
+ not. A `gdb.Objfile' object can become invalid if the object file
+ it refers to is not loaded in GDB any longer. All other
+ `gdb.Objfile' methods will throw an exception if it is invalid at
+ the time the method is called.
+
+
+File: gdb.info, Node: Frames In Python, Next: Blocks In Python, Prev: Objfiles In Python, Up: Python API
+
+23.2.2.16 Accessing inferior stack frames from Python.
+......................................................
+
+When the debugged program stops, GDB is able to analyze its call stack
+(*note Stack frames: Frames.). The `gdb.Frame' class represents a
+frame in the stack. A `gdb.Frame' object is only valid while its
+corresponding frame exists in the inferior's stack. If you try to use
+an invalid frame object, GDB will throw a `gdb.error' exception (*note
+Exception Handling::).
+
+ Two `gdb.Frame' objects can be compared for equality with the `=='
+operator, like:
+
+ (gdb) python print gdb.newest_frame() == gdb.selected_frame ()
+ True
+
+ The following frame-related functions are available in the `gdb'
+module:
+
+ -- Function: gdb.selected_frame ()
+ Return the selected frame object. (*note Selecting a Frame:
+ Selection.).
+
+ -- Function: gdb.newest_frame ()
+ Return the newest frame object for the selected thread.
+
+ -- Function: gdb.frame_stop_reason_string (reason)
+ Return a string explaining the reason why GDB stopped unwinding
+ frames, as expressed by the given REASON code (an integer, see the
+ `unwind_stop_reason' method further down in this section).
+
+ A `gdb.Frame' object has the following methods:
+
+ -- Function: Frame.is_valid ()
+ Returns true if the `gdb.Frame' object is valid, false if not.
+ A frame object can become invalid if the frame it refers to
+ doesn't exist anymore in the inferior. All `gdb.Frame'
+ methods will throw an exception if it is invalid at the time
+ the method is called.
+
+ -- Function: Frame.name ()
+ Returns the function name of the frame, or `None' if it can't
+ be obtained.
+
+ -- Function: Frame.type ()
+ Returns the type of the frame. The value can be one of:
+ `gdb.NORMAL_FRAME'
+ An ordinary stack frame.
+
+ `gdb.DUMMY_FRAME'
+ A fake stack frame that was created by GDB when
+ performing an inferior function call.
+
+ `gdb.INLINE_FRAME'
+ A frame representing an inlined function. The function
+ was inlined into a `gdb.NORMAL_FRAME' that is older than
+ this one.
+
+ `gdb.TAILCALL_FRAME'
+ A frame representing a tail call. *Note Tail Call
+ Frames::.
+
+ `gdb.SIGTRAMP_FRAME'
+ A signal trampoline frame. This is the frame created by
+ the OS when it calls into a signal handler.
+
+ `gdb.ARCH_FRAME'
+ A fake stack frame representing a cross-architecture
+ call.
+
+ `gdb.SENTINEL_FRAME'
+ This is like `gdb.NORMAL_FRAME', but it is only used for
+ the newest frame.
+
+ -- Function: Frame.unwind_stop_reason ()
+ Return an integer representing the reason why it's not
+ possible to find more frames toward the outermost frame. Use
+ `gdb.frame_stop_reason_string' to convert the value returned
+ by this function to a string. The value can be one of:
+
+ `gdb.FRAME_UNWIND_NO_REASON'
+ No particular reason (older frames should be available).
+
+ `gdb.FRAME_UNWIND_NULL_ID'
+ The previous frame's analyzer returns an invalid result.
+
+ `gdb.FRAME_UNWIND_OUTERMOST'
+ This frame is the outermost.
+
+ `gdb.FRAME_UNWIND_UNAVAILABLE'
+ Cannot unwind further, because that would require
+ knowing the values of registers or memory that have not
+ been collected.
+
+ `gdb.FRAME_UNWIND_INNER_ID'
+ This frame ID looks like it ought to belong to a NEXT
+ frame, but we got it for a PREV frame. Normally, this
+ is a sign of unwinder failure. It could also indicate
+ stack corruption.
+
+ `gdb.FRAME_UNWIND_SAME_ID'
+ This frame has the same ID as the previous one. That
+ means that unwinding further would almost certainly give
+ us another frame with exactly the same ID, so break the
+ chain. Normally, this is a sign of unwinder failure.
+ It could also indicate stack corruption.
+
+ `gdb.FRAME_UNWIND_NO_SAVED_PC'
+ The frame unwinder did not find any saved PC, but we
+ needed one to unwind further.
+
+ `gdb.FRAME_UNWIND_FIRST_ERROR'
+ Any stop reason greater or equal to this value indicates
+ some kind of error. This special value facilitates
+ writing code that tests for errors in unwinding in a way
+ that will work correctly even if the list of the other
+ values is modified in future GDB versions. Using it,
+ you could write:
+ reason = gdb.selected_frame().unwind_stop_reason ()
+ reason_str = gdb.frame_stop_reason_string (reason)
+ if reason >= gdb.FRAME_UNWIND_FIRST_ERROR:
+ print "An error occured: %s" % reason_str
+
+
+ -- Function: Frame.pc ()
+ Returns the frame's resume address.
+
+ -- Function: Frame.block ()
+ Return the frame's code block. *Note Blocks In Python::.
+
+ -- Function: Frame.function ()
+ Return the symbol for the function corresponding to this
+ frame. *Note Symbols In Python::.
+
+ -- Function: Frame.older ()
+ Return the frame that called this frame.
+
+ -- Function: Frame.newer ()
+ Return the frame called by this frame.
+
+ -- Function: Frame.find_sal ()
+ Return the frame's symtab and line object. *Note Symbol
+ Tables In Python::.
+
+ -- Function: Frame.read_var (variable [, block])
+ Return the value of VARIABLE in this frame. If the optional
+ argument BLOCK is provided, search for the variable from that
+ block; otherwise start at the frame's current block (which is
+ determined by the frame's current program counter). VARIABLE
+ must be a string or a `gdb.Symbol' object. BLOCK must be a
+ `gdb.Block' object.
+
+ -- Function: Frame.select ()
+ Set this frame to be the selected frame. *Note Examining the
+ Stack: Stack.
+
+
+File: gdb.info, Node: Blocks In Python, Next: Symbols In Python, Prev: Frames In Python, Up: Python API
+
+23.2.2.17 Accessing frame blocks from Python.
+.............................................
+
+Within each frame, GDB maintains information on each block stored in
+that frame. These blocks are organized hierarchically, and are
+represented individually in Python as a `gdb.Block'. Please see *Note
+Frames In Python::, for a more in-depth discussion on frames.
+Furthermore, see *Note Examining the Stack: Stack, for more detailed
+technical information on GDB's book-keeping of the stack.
+
+ The following block-related functions are available in the `gdb'
+module:
+
+ -- Function: gdb.block_for_pc (pc)
+ Return the `gdb.Block' containing the given PC value. If the
+ block cannot be found for the PC value specified, the function
+ will return `None'.
+
+ A `gdb.Block' object has the following methods:
+
+ -- Function: Block.is_valid ()
+ Returns `True' if the `gdb.Block' object is valid, `False' if
+ not. A block object can become invalid if the block it
+ refers to doesn't exist anymore in the inferior. All other
+ `gdb.Block' methods will throw an exception if it is invalid
+ at the time the method is called. This method is also made
+ available to the Python iterator object that `gdb.Block'
+ provides in an iteration context and via the Python `iter'
+ built-in function.
+
+ A `gdb.Block' object has the following attributes:
+
+ -- Variable: Block.start
+ The start address of the block. This attribute is not
+ writable.
+
+ -- Variable: Block.end
+ The end address of the block. This attribute is not writable.
+
+ -- Variable: Block.function
+ The name of the block represented as a `gdb.Symbol'. If the
+ block is not named, then this attribute holds `None'. This
+ attribute is not writable.
+
+ -- Variable: Block.superblock
+ The block containing this block. If this parent block does
+ not exist, this attribute holds `None'. This attribute is
+ not writable.
+
+ -- Variable: Block.global_block
+ The global block associated with this block. This attribute
+ is not writable.
+
+ -- Variable: Block.static_block
+ The static block associated with this block. This attribute
+ is not writable.
+
+ -- Variable: Block.is_global
+ `True' if the `gdb.Block' object is a global block, `False'
+ if not. This attribute is not writable.
+
+ -- Variable: Block.is_static
+ `True' if the `gdb.Block' object is a static block, `False'
+ if not. This attribute is not writable.
+
+
+File: gdb.info, Node: Symbols In Python, Next: Symbol Tables In Python, Prev: Blocks In Python, Up: Python API
+
+23.2.2.18 Python representation of Symbols.
+...........................................
+
+GDB represents every variable, function and type as an entry in a
+symbol table. *Note Examining the Symbol Table: Symbols. Similarly,
+Python represents these symbols in GDB with the `gdb.Symbol' object.
+
+ The following symbol-related functions are available in the `gdb'
+module:
+
+ -- Function: gdb.lookup_symbol (name [, block [, domain]])
+ This function searches for a symbol by name. The search scope can
+ be restricted to the parameters defined in the optional domain and
+ block arguments.
+
+ NAME is the name of the symbol. It must be a string. The
+ optional BLOCK argument restricts the search to symbols visible in
+ that BLOCK. The BLOCK argument must be a `gdb.Block' object. If
+ omitted, the block for the current frame is used. The optional
+ DOMAIN argument restricts the search to the domain type. The
+ DOMAIN argument must be a domain constant defined in the `gdb'
+ module and described later in this chapter.
+
+ The result is a tuple of two elements. The first element is a
+ `gdb.Symbol' object or `None' if the symbol is not found. If the
+ symbol is found, the second element is `True' if the symbol is a
+ field of a method's object (e.g., `this' in C++), otherwise it is
+ `False'. If the symbol is not found, the second element is
+ `False'.
+
+ -- Function: gdb.lookup_global_symbol (name [, domain])
+ This function searches for a global symbol by name. The search
+ scope can be restricted to by the domain argument.
+
+ NAME is the name of the symbol. It must be a string. The
+ optional DOMAIN argument restricts the search to the domain type.
+ The DOMAIN argument must be a domain constant defined in the `gdb'
+ module and described later in this chapter.
+
+ The result is a `gdb.Symbol' object or `None' if the symbol is not
+ found.
+
+ A `gdb.Symbol' object has the following attributes:
+
+ -- Variable: Symbol.type
+ The type of the symbol or `None' if no type is recorded.
+ This attribute is represented as a `gdb.Type' object. *Note
+ Types In Python::. This attribute is not writable.
+
+ -- Variable: Symbol.symtab
+ The symbol table in which the symbol appears. This attribute
+ is represented as a `gdb.Symtab' object. *Note Symbol Tables
+ In Python::. This attribute is not writable.
+
+ -- Variable: Symbol.name
+ The name of the symbol as a string. This attribute is not
+ writable.
+
+ -- Variable: Symbol.linkage_name
+ The name of the symbol, as used by the linker (i.e., may be
+ mangled). This attribute is not writable.
+
+ -- Variable: Symbol.print_name
+ The name of the symbol in a form suitable for output. This
+ is either `name' or `linkage_name', depending on whether the
+ user asked GDB to display demangled or mangled names.
+
+ -- Variable: Symbol.addr_class
+ The address class of the symbol. This classifies how to find
+ the value of a symbol. Each address class is a constant
+ defined in the `gdb' module and described later in this
+ chapter.
+
+ -- Variable: Symbol.is_argument
+ `True' if the symbol is an argument of a function.
+
+ -- Variable: Symbol.is_constant
+ `True' if the symbol is a constant.
+
+ -- Variable: Symbol.is_function
+ `True' if the symbol is a function or a method.
+
+ -- Variable: Symbol.is_variable
+ `True' if the symbol is a variable.
+
+ A `gdb.Symbol' object has the following methods:
+
+ -- Function: Symbol.is_valid ()
+ Returns `True' if the `gdb.Symbol' object is valid, `False'
+ if not. A `gdb.Symbol' object can become invalid if the
+ symbol it refers to does not exist in GDB any longer. All
+ other `gdb.Symbol' methods will throw an exception if it is
+ invalid at the time the method is called.
+
+ The available domain categories in `gdb.Symbol' are represented as
+constants in the `gdb' module:
+
+`gdb.SYMBOL_UNDEF_DOMAIN'
+ This is used when a domain has not been discovered or none of the
+ following domains apply. This usually indicates an error either
+ in the symbol information or in GDB's handling of symbols.
+
+`gdb.SYMBOL_VAR_DOMAIN'
+ This domain contains variables, function names, typedef names and
+ enum type values.
+
+`gdb.SYMBOL_STRUCT_DOMAIN'
+ This domain holds struct, union and enum type names.
+
+`gdb.SYMBOL_LABEL_DOMAIN'
+ This domain contains names of labels (for gotos).
+
+`gdb.SYMBOL_VARIABLES_DOMAIN'
+ This domain holds a subset of the `SYMBOLS_VAR_DOMAIN'; it
+ contains everything minus functions and types.
+
+`gdb.SYMBOL_FUNCTION_DOMAIN'
+ This domain contains all functions.
+
+`gdb.SYMBOL_TYPES_DOMAIN'
+ This domain contains all types.
+
+ The available address class categories in `gdb.Symbol' are
+represented as constants in the `gdb' module:
+
+`gdb.SYMBOL_LOC_UNDEF'
+ If this is returned by address class, it indicates an error either
+ in the symbol information or in GDB's handling of symbols.
+
+`gdb.SYMBOL_LOC_CONST'
+ Value is constant int.
+
+`gdb.SYMBOL_LOC_STATIC'
+ Value is at a fixed address.
+
+`gdb.SYMBOL_LOC_REGISTER'
+ Value is in a register.
+
+`gdb.SYMBOL_LOC_ARG'
+ Value is an argument. This value is at the offset stored within
+ the symbol inside the frame's argument list.
+
+`gdb.SYMBOL_LOC_REF_ARG'
+ Value address is stored in the frame's argument list. Just like
+ `LOC_ARG' except that the value's address is stored at the offset,
+ not the value itself.
+
+`gdb.SYMBOL_LOC_REGPARM_ADDR'
+ Value is a specified register. Just like `LOC_REGISTER' except
+ the register holds the address of the argument instead of the
+ argument itself.
+
+`gdb.SYMBOL_LOC_LOCAL'
+ Value is a local variable.
+
+`gdb.SYMBOL_LOC_TYPEDEF'
+ Value not used. Symbols in the domain `SYMBOL_STRUCT_DOMAIN' all
+ have this class.
+
+`gdb.SYMBOL_LOC_BLOCK'
+ Value is a block.
+
+`gdb.SYMBOL_LOC_CONST_BYTES'
+ Value is a byte-sequence.
+
+`gdb.SYMBOL_LOC_UNRESOLVED'
+ Value is at a fixed address, but the address of the variable has
+ to be determined from the minimal symbol table whenever the
+ variable is referenced.
+
+`gdb.SYMBOL_LOC_OPTIMIZED_OUT'
+ The value does not actually exist in the program.
+
+`gdb.SYMBOL_LOC_COMPUTED'
+ The value's address is a computed location.
+
+
+File: gdb.info, Node: Symbol Tables In Python, Next: Lazy Strings In Python, Prev: Symbols In Python, Up: Python API
+
+23.2.2.19 Symbol table representation in Python.
+................................................
+
+Access to symbol table data maintained by GDB on the inferior is
+exposed to Python via two objects: `gdb.Symtab_and_line' and
+`gdb.Symtab'. Symbol table and line data for a frame is returned from
+the `find_sal' method in `gdb.Frame' object. *Note Frames In Python::.
+
+ For more information on GDB's symbol table management, see *Note
+Examining the Symbol Table: Symbols, for more information.
+
+ A `gdb.Symtab_and_line' object has the following attributes:
+
+ -- Variable: Symtab_and_line.symtab
+ The symbol table object (`gdb.Symtab') for this frame. This
+ attribute is not writable.
+
+ -- Variable: Symtab_and_line.pc
+ Indicates the current program counter address. This
+ attribute is not writable.
+
+ -- Variable: Symtab_and_line.line
+ Indicates the current line number for this object. This
+ attribute is not writable.
+
+ A `gdb.Symtab_and_line' object has the following methods:
+
+ -- Function: Symtab_and_line.is_valid ()
+ Returns `True' if the `gdb.Symtab_and_line' object is valid,
+ `False' if not. A `gdb.Symtab_and_line' object can become
+ invalid if the Symbol table and line object it refers to does
+ not exist in GDB any longer. All other `gdb.Symtab_and_line'
+ methods will throw an exception if it is invalid at the time
+ the method is called.
+
+ A `gdb.Symtab' object has the following attributes:
+
+ -- Variable: Symtab.filename
+ The symbol table's source filename. This attribute is not
+ writable.
+
+ -- Variable: Symtab.objfile
+ The symbol table's backing object file. *Note Objfiles In
+ Python::. This attribute is not writable.
+
+ A `gdb.Symtab' object has the following methods:
+
+ -- Function: Symtab.is_valid ()
+ Returns `True' if the `gdb.Symtab' object is valid, `False'
+ if not. A `gdb.Symtab' object can become invalid if the
+ symbol table it refers to does not exist in GDB any longer.
+ All other `gdb.Symtab' methods will throw an exception if it
+ is invalid at the time the method is called.
+
+ -- Function: Symtab.fullname ()
+ Return the symbol table's source absolute file name.
+
+
+File: gdb.info, Node: Breakpoints In Python, Next: Finish Breakpoints in Python, Prev: Lazy Strings In Python, Up: Python API
+
+23.2.2.20 Manipulating breakpoints using Python
+...............................................
+
+Python code can manipulate breakpoints via the `gdb.Breakpoint' class.
+
+ -- Function: Breakpoint.__init__ (spec [, type [, wp_class
+ [,internal]]])
+ Create a new breakpoint. SPEC is a string naming the location of
+ the breakpoint, or an expression that defines a watchpoint. The
+ contents can be any location recognized by the `break' command, or
+ in the case of a watchpoint, by the `watch' command. The optional
+ TYPE denotes the breakpoint to create from the types defined later
+ in this chapter. This argument can be either: `gdb.BP_BREAKPOINT'
+ or `gdb.BP_WATCHPOINT'. TYPE defaults to `gdb.BP_BREAKPOINT'.
+ The optional INTERNAL argument allows the breakpoint to become
+ invisible to the user. The breakpoint will neither be reported
+ when created, nor will it be listed in the output from `info
+ breakpoints' (but will be listed with the `maint info breakpoints'
+ command). The optional WP_CLASS argument defines the class of
+ watchpoint to create, if TYPE is `gdb.BP_WATCHPOINT'. If a
+ watchpoint class is not provided, it is assumed to be a
+ `gdb.WP_WRITE' class.
+
+ -- Function: Breakpoint.stop (self)
+ The `gdb.Breakpoint' class can be sub-classed and, in particular,
+ you may choose to implement the `stop' method. If this method is
+ defined as a sub-class of `gdb.Breakpoint', it will be called when
+ the inferior reaches any location of a breakpoint which
+ instantiates that sub-class. If the method returns `True', the
+ inferior will be stopped at the location of the breakpoint,
+ otherwise the inferior will continue.
+
+ If there are multiple breakpoints at the same location with a
+ `stop' method, each one will be called regardless of the return
+ status of the previous. This ensures that all `stop' methods have
+ a chance to execute at that location. In this scenario if one of
+ the methods returns `True' but the others return `False', the
+ inferior will still be stopped.
+
+ You should not alter the execution state of the inferior (i.e.,
+ step, next, etc.), alter the current frame context (i.e., change
+ the current active frame), or alter, add or delete any breakpoint.
+ As a general rule, you should not alter any data within GDB or
+ the inferior at this time.
+
+ Example `stop' implementation:
+
+ class MyBreakpoint (gdb.Breakpoint):
+ def stop (self):
+ inf_val = gdb.parse_and_eval("foo")
+ if inf_val == 3:
+ return True
+ return False
+
+ The available watchpoint types represented by constants are defined
+in the `gdb' module:
+
+`gdb.WP_READ'
+ Read only watchpoint.
+
+`gdb.WP_WRITE'
+ Write only watchpoint.
+
+`gdb.WP_ACCESS'
+ Read/Write watchpoint.
+
+ -- Function: Breakpoint.is_valid ()
+ Return `True' if this `Breakpoint' object is valid, `False'
+ otherwise. A `Breakpoint' object can become invalid if the user
+ deletes the breakpoint. In this case, the object still exists,
+ but the underlying breakpoint does not. In the cases of
+ watchpoint scope, the watchpoint remains valid even if execution
+ of the inferior leaves the scope of that watchpoint.
+
+ -- Function: Breakpoint.delete
+ Permanently deletes the GDB breakpoint. This also invalidates the
+ Python `Breakpoint' object. Any further access to this object's
+ attributes or methods will raise an error.
+
+ -- Variable: Breakpoint.enabled
+ This attribute is `True' if the breakpoint is enabled, and `False'
+ otherwise. This attribute is writable.
+
+ -- Variable: Breakpoint.silent
+ This attribute is `True' if the breakpoint is silent, and `False'
+ otherwise. This attribute is writable.
+
+ Note that a breakpoint can also be silent if it has commands and
+ the first command is `silent'. This is not reported by the
+ `silent' attribute.
+
+ -- Variable: Breakpoint.thread
+ If the breakpoint is thread-specific, this attribute holds the
+ thread id. If the breakpoint is not thread-specific, this
+ attribute is `None'. This attribute is writable.
+
+ -- Variable: Breakpoint.task
+ If the breakpoint is Ada task-specific, this attribute holds the
+ Ada task id. If the breakpoint is not task-specific (or the
+ underlying language is not Ada), this attribute is `None'. This
+ attribute is writable.
+
+ -- Variable: Breakpoint.ignore_count
+ This attribute holds the ignore count for the breakpoint, an
+ integer. This attribute is writable.
+
+ -- Variable: Breakpoint.number
+ This attribute holds the breakpoint's number -- the identifier
+ used by the user to manipulate the breakpoint. This attribute is
+ not writable.
+
+ -- Variable: Breakpoint.type
+ This attribute holds the breakpoint's type -- the identifier used
+ to determine the actual breakpoint type or use-case. This
+ attribute is not writable.
+
+ -- Variable: Breakpoint.visible
+ This attribute tells whether the breakpoint is visible to the user
+ when set, or when the `info breakpoints' command is run. This
+ attribute is not writable.
+
+ The available types are represented by constants defined in the `gdb'
+module:
+
+`gdb.BP_BREAKPOINT'
+ Normal code breakpoint.
+
+`gdb.BP_WATCHPOINT'
+ Watchpoint breakpoint.
+
+`gdb.BP_HARDWARE_WATCHPOINT'
+ Hardware assisted watchpoint.
+
+`gdb.BP_READ_WATCHPOINT'
+ Hardware assisted read watchpoint.
+
+`gdb.BP_ACCESS_WATCHPOINT'
+ Hardware assisted access watchpoint.
+
+ -- Variable: Breakpoint.hit_count
+ This attribute holds the hit count for the breakpoint, an integer.
+ This attribute is writable, but currently it can only be set to
+ zero.
+
+ -- Variable: Breakpoint.location
+ This attribute holds the location of the breakpoint, as specified
+ by the user. It is a string. If the breakpoint does not have a
+ location (that is, it is a watchpoint) the attribute's value is
+ `None'. This attribute is not writable.
+
+ -- Variable: Breakpoint.expression
+ This attribute holds a breakpoint expression, as specified by the
+ user. It is a string. If the breakpoint does not have an
+ expression (the breakpoint is not a watchpoint) the attribute's
+ value is `None'. This attribute is not writable.
+
+ -- Variable: Breakpoint.condition
+ This attribute holds the condition of the breakpoint, as specified
+ by the user. It is a string. If there is no condition, this
+ attribute's value is `None'. This attribute is writable.
+
+ -- Variable: Breakpoint.commands
+ This attribute holds the commands attached to the breakpoint. If
+ there are commands, this attribute's value is a string holding all
+ the commands, separated by newlines. If there are no commands,
+ this attribute is `None'. This attribute is not writable.
+
+
+File: gdb.info, Node: Finish Breakpoints in Python, Prev: Breakpoints In Python, Up: Python API
+
+23.2.2.21 Finish Breakpoints
+............................
+
+A finish breakpoint is a temporary breakpoint set at the return address
+of a frame, based on the `finish' command. `gdb.FinishBreakpoint'
+extends `gdb.Breakpoint'. The underlying breakpoint will be disabled
+and deleted when the execution will run out of the breakpoint scope
+(i.e. `Breakpoint.stop' or `FinishBreakpoint.out_of_scope' triggered).
+Finish breakpoints are thread specific and must be create with the right
+thread selected.
+
+ -- Function: FinishBreakpoint.__init__ ([frame] [, internal])
+ Create a finish breakpoint at the return address of the `gdb.Frame'
+ object FRAME. If FRAME is not provided, this defaults to the
+ newest frame. The optional INTERNAL argument allows the
+ breakpoint to become invisible to the user. *Note Breakpoints In
+ Python::, for further details about this argument.
+
+ -- Function: FinishBreakpoint.out_of_scope (self)
+ In some circumstances (e.g. `longjmp', C++ exceptions, GDB
+ `return' command, ...), a function may not properly terminate, and
+ thus never hit the finish breakpoint. When GDB notices such a
+ situation, the `out_of_scope' callback will be triggered.
+
+ You may want to sub-class `gdb.FinishBreakpoint' and override this
+ method:
+
+ class MyFinishBreakpoint (gdb.FinishBreakpoint)
+ def stop (self):
+ print "normal finish"
+ return True
+
+ def out_of_scope ():
+ print "abnormal finish"
+
+ -- Variable: FinishBreakpoint.return_value
+ When GDB is stopped at a finish breakpoint and the frame used to
+ build the `gdb.FinishBreakpoint' object had debug symbols, this
+ attribute will contain a `gdb.Value' object corresponding to the
+ return value of the function. The value will be `None' if the
+ function return type is `void' or if the return value was not
+ computable. This attribute is not writable.
+
+
+File: gdb.info, Node: Lazy Strings In Python, Next: Breakpoints In Python, Prev: Symbol Tables In Python, Up: Python API
+
+23.2.2.22 Python representation of lazy strings.
+................................................
+
+A "lazy string" is a string whose contents is not retrieved or encoded
+until it is needed.
+
+ A `gdb.LazyString' is represented in GDB as an `address' that points
+to a region of memory, an `encoding' that will be used to encode that
+region of memory, and a `length' to delimit the region of memory that
+represents the string. The difference between a `gdb.LazyString' and a
+string wrapped within a `gdb.Value' is that a `gdb.LazyString' will be
+treated differently by GDB when printing. A `gdb.LazyString' is
+retrieved and encoded during printing, while a `gdb.Value' wrapping a
+string is immediately retrieved and encoded on creation.
+
+ A `gdb.LazyString' object has the following functions:
+
+ -- Function: LazyString.value ()
+ Convert the `gdb.LazyString' to a `gdb.Value'. This value will
+ point to the string in memory, but will lose all the delayed
+ retrieval, encoding and handling that GDB applies to a
+ `gdb.LazyString'.
+
+ -- Variable: LazyString.address
+ This attribute holds the address of the string. This attribute is
+ not writable.
+
+ -- Variable: LazyString.length
+ This attribute holds the length of the string in characters. If
+ the length is -1, then the string will be fetched and encoded up
+ to the first null of appropriate width. This attribute is not
+ writable.
+
+ -- Variable: LazyString.encoding
+ This attribute holds the encoding that will be applied to the
+ string when the string is printed by GDB. If the encoding is not
+ set, or contains an empty string, then GDB will select the most
+ appropriate encoding when the string is printed. This attribute
+ is not writable.
+
+ -- Variable: LazyString.type
+ This attribute holds the type that is represented by the lazy
+ string's type. For a lazy string this will always be a pointer
+ type. To resolve this to the lazy string's character type, use
+ the type's `target' method. *Note Types In Python::. This
+ attribute is not writable.
+
+
+File: gdb.info, Node: Auto-loading, Next: Python modules, Prev: Python API, Up: Python
+
+23.2.3 Auto-loading
+-------------------
+
+When a new object file is read (for example, due to the `file' command,
+or because the inferior has loaded a shared library), GDB will look for
+Python support scripts in several ways: `OBJFILE-gdb.py' and
+`.debug_gdb_scripts' section.
+
+* Menu:
+
+* objfile-gdb.py file:: The `OBJFILE-gdb.py' file
+* .debug_gdb_scripts section:: The `.debug_gdb_scripts' section
+* Which flavor to choose?::
+
+ The auto-loading feature is useful for supplying application-specific
+debugging commands and scripts.
+
+ Auto-loading can be enabled or disabled, and the list of auto-loaded
+scripts can be printed.
+
+`set auto-load-scripts [yes|no]'
+ Enable or disable the auto-loading of Python scripts.
+
+`show auto-load-scripts'
+ Show whether auto-loading of Python scripts is enabled or disabled.
+
+`info auto-load-scripts [REGEXP]'
+ Print the list of all scripts that GDB auto-loaded.
+
+ Also printed is the list of scripts that were mentioned in the
+ `.debug_gdb_scripts' section and were not found (*note
+ .debug_gdb_scripts section::). This is useful because their names
+ are not printed when GDB tries to load them and fails. There may
+ be many of them, and printing an error message for each one is
+ problematic.
+
+ If REGEXP is supplied only scripts with matching names are printed.
+
+ Example:
+
+ (gdb) info auto-load-scripts
+ Loaded Script
+ Yes py-section-script.py
+ full name: /tmp/py-section-script.py
+ Missing my-foo-pretty-printers.py
+
+ When reading an auto-loaded file, GDB sets the "current objfile".
+This is available via the `gdb.current_objfile' function (*note
+Objfiles In Python::). This can be useful for registering
+objfile-specific pretty-printers.
+
+
+File: gdb.info, Node: objfile-gdb.py file, Next: .debug_gdb_scripts section, Up: Auto-loading
+
+23.2.3.1 The `OBJFILE-gdb.py' file
+..................................
+
+When a new object file is read, GDB looks for a file named
+`OBJFILE-gdb.py', where OBJFILE is the object file's real name, formed
+by ensuring that the file name is absolute, following all symlinks, and
+resolving `.' and `..' components. If this file exists and is
+readable, GDB will evaluate it as a Python script.
+
+ If this file does not exist, and if the parameter
+`debug-file-directory' is set (*note Separate Debug Files::), then GDB
+will look for REAL-NAME in all of the directories mentioned in the
+value of `debug-file-directory'.
+
+ Finally, if this file does not exist, then GDB will look for a file
+named `DATA-DIRECTORY/python/auto-load/REAL-NAME', where DATA-DIRECTORY
+is GDB's data directory (available via `show data-directory', *note
+Data Files::), and REAL-NAME is the object file's real name, as
+described above.
+
+ GDB does not track which files it has already auto-loaded this way.
+GDB will load the associated script every time the corresponding
+OBJFILE is opened. So your `-gdb.py' file should be careful to avoid
+errors if it is evaluated more than once.
+
+
+File: gdb.info, Node: .debug_gdb_scripts section, Next: Which flavor to choose?, Prev: objfile-gdb.py file, Up: Auto-loading
+
+23.2.3.2 The `.debug_gdb_scripts' section
+.........................................
+
+For systems using file formats like ELF and COFF, when GDB loads a new
+object file it will look for a special section named
+`.debug_gdb_scripts'. If this section exists, its contents is a list
+of names of scripts to load.
+
+ GDB will look for each specified script file first in the current
+directory and then along the source search path (*note Specifying
+Source Directories: Source Path.), except that `$cdir' is not searched,
+since the compilation directory is not relevant to scripts.
+
+ Entries can be placed in section `.debug_gdb_scripts' with, for
+example, this GCC macro:
+
+ /* Note: The "MS" section flags are to remove duplicates. */
+ #define DEFINE_GDB_SCRIPT(script_name) \
+ asm("\
+ .pushsection \".debug_gdb_scripts\", \"MS\",@progbits,1\n\
+ .byte 1\n\
+ .asciz \"" script_name "\"\n\
+ .popsection \n\
+ ");
+
+Then one can reference the macro in a header or source file like this:
+
+ DEFINE_GDB_SCRIPT ("my-app-scripts.py")
+
+ The script name may include directories if desired.
+
+ If the macro is put in a header, any application or library using
+this header will get a reference to the specified script.
+
+
+File: gdb.info, Node: Which flavor to choose?, Prev: .debug_gdb_scripts section, Up: Auto-loading
+
+23.2.3.3 Which flavor to choose?
+................................
+
+Given the multiple ways of auto-loading Python scripts, it might not
+always be clear which one to choose. This section provides some
+guidance.
+
+ Benefits of the `-gdb.py' way:
+
+ * Can be used with file formats that don't support multiple sections.
+
+ * Ease of finding scripts for public libraries.
+
+ Scripts specified in the `.debug_gdb_scripts' section are searched
+ for in the source search path. For publicly installed libraries,
+ e.g., `libstdc++', there typically isn't a source directory in
+ which to find the script.
+
+ * Doesn't require source code additions.
+
+ Benefits of the `.debug_gdb_scripts' way:
+
+ * Works with static linking.
+
+ Scripts for libraries done the `-gdb.py' way require an objfile to
+ trigger their loading. When an application is statically linked
+ the only objfile available is the executable, and it is cumbersome
+ to attach all the scripts from all the input libraries to the
+ executable's `-gdb.py' script.
+
+ * Works with classes that are entirely inlined.
+
+ Some classes can be entirely inlined, and thus there may not be an
+ associated shared library to attach a `-gdb.py' script to.
+
+ * Scripts needn't be copied out of the source tree.
+
+ In some circumstances, apps can be built out of large collections
+ of internal libraries, and the build infrastructure necessary to
+ install the `-gdb.py' scripts in a place where GDB can find them is
+ cumbersome. It may be easier to specify the scripts in the
+ `.debug_gdb_scripts' section as relative paths, and add a path to
+ the top of the source tree to the source search path.
+
+
+File: gdb.info, Node: Python modules, Prev: Auto-loading, Up: Python
+
+23.2.4 Python modules
+---------------------
+
+GDB comes with several modules to assist writing Python code.
+
+* Menu:
+
+* gdb.printing:: Building and registering pretty-printers.
+* gdb.types:: Utilities for working with types.
+* gdb.prompt:: Utilities for prompt value substitution.
+
+
+File: gdb.info, Node: gdb.printing, Next: gdb.types, Up: Python modules
+
+23.2.4.1 gdb.printing
+.....................
+
+This module provides a collection of utilities for working with
+pretty-printers.
+
+`PrettyPrinter (NAME, SUBPRINTERS=None)'
+ This class specifies the API that makes `info pretty-printer',
+ `enable pretty-printer' and `disable pretty-printer' work.
+ Pretty-printers should generally inherit from this class.
+
+`SubPrettyPrinter (NAME)'
+ For printers that handle multiple types, this class specifies the
+ corresponding API for the subprinters.
+
+`RegexpCollectionPrettyPrinter (NAME)'
+ Utility class for handling multiple printers, all recognized via
+ regular expressions. *Note Writing a Pretty-Printer::, for an
+ example.
+
+`register_pretty_printer (OBJ, PRINTER, REPLACE=False)'
+ Register PRINTER with the pretty-printer list of OBJ. If REPLACE
+ is `True' then any existing copy of the printer is replaced.
+ Otherwise a `RuntimeError' exception is raised if a printer with
+ the same name already exists.
+
+
+File: gdb.info, Node: gdb.types, Next: gdb.prompt, Prev: gdb.printing, Up: Python modules
+
+23.2.4.2 gdb.types
+..................
+
+This module provides a collection of utilities for working with
+`gdb.Types' objects.
+
+`get_basic_type (TYPE)'
+ Return TYPE with const and volatile qualifiers stripped, and with
+ typedefs and C++ references converted to the underlying type.
+
+ C++ example:
+
+ typedef const int const_int;
+ const_int foo (3);
+ const_int& foo_ref (foo);
+ int main () { return 0; }
+
+ Then in gdb:
+
+ (gdb) start
+ (gdb) python import gdb.types
+ (gdb) python foo_ref = gdb.parse_and_eval("foo_ref")
+ (gdb) python print gdb.types.get_basic_type(foo_ref.type)
+ int
+
+`has_field (TYPE, FIELD)'
+ Return `True' if TYPE, assumed to be a type with fields (e.g., a
+ structure or union), has field FIELD.
+
+`make_enum_dict (ENUM_TYPE)'
+ Return a Python `dictionary' type produced from ENUM_TYPE.
+
+`deep_items (TYPE)'
+ Returns a Python iterator similar to the standard
+ `gdb.Type.iteritems' method, except that the iterator returned by
+ `deep_items' will recursively traverse anonymous struct or union
+ fields. For example:
+
+ struct A
+ {
+ int a;
+ union {
+ int b0;
+ int b1;
+ };
+ };
+
+ Then in GDB:
+ (gdb) python import gdb.types
+ (gdb) python struct_a = gdb.lookup_type("struct A")
+ (gdb) python print struct_a.keys ()
+ {['a', '']}
+ (gdb) python print [k for k,v in gdb.types.deep_items(struct_a)]
+ {['a', 'b0', 'b1']}
+
+
+
+File: gdb.info, Node: gdb.prompt, Prev: gdb.types, Up: Python modules
+
+23.2.4.3 gdb.prompt
+...................
+
+This module provides a method for prompt value-substitution.
+
+`substitute_prompt (STRING)'
+ Return STRING with escape sequences substituted by values. Some
+ escape sequences take arguments. You can specify arguments inside
+ "{}" immediately following the escape sequence.
+
+ The escape sequences you can pass to this function are:
+
+ `\\'
+ Substitute a backslash.
+
+ `\e'
+ Substitute an ESC character.
+
+ `\f'
+ Substitute the selected frame; an argument names a frame
+ parameter.
+
+ `\n'
+ Substitute a newline.
+
+ `\p'
+ Substitute a parameter's value; the argument names the
+ parameter.
+
+ `\r'
+ Substitute a carriage return.
+
+ `\t'
+ Substitute the selected thread; an argument names a thread
+ parameter.
+
+ `\v'
+ Substitute the version of GDB.
+
+ `\w'
+ Substitute the current working directory.
+
+ `\['
+ Begin a sequence of non-printing characters. These sequences
+ are typically used with the ESC character, and are not
+ counted in the string length. Example:
+ "\[\e[0;34m\](gdb)\[\e[0m\]" will return a blue-colored
+ "(gdb)" prompt where the length is five.
+
+ `\]'
+ End a sequence of non-printing characters.
+
+ For example:
+
+ substitute_prompt (``frame: \f,
+ print arguments: \p{print frame-arguments}'')
+
+will return the string:
+
+
+ "frame: main, print arguments: scalars"
+
+
+File: gdb.info, Node: Aliases, Prev: Python, Up: Extending GDB
+
+23.3 Creating new spellings of existing commands
+================================================
+
+It is often useful to define alternate spellings of existing commands.
+For example, if a new GDB command defined in Python has a long name to
+type, it is handy to have an abbreviated version of it that involves
+less typing.
+
+ GDB itself uses aliases. For example `s' is an alias of the `step'
+command even though it is otherwise an ambiguous abbreviation of other
+commands like `set' and `show'.
+
+ Aliases are also used to provide shortened or more common versions
+of multi-word commands. For example, GDB provides the `tty' alias of
+the `set inferior-tty' command.
+
+ You can define a new alias with the `alias' command.
+
+`alias [-a] [--] ALIAS = COMMAND'
+
+ ALIAS specifies the name of the new alias. Each word of ALIAS must
+consist of letters, numbers, dashes and underscores.
+
+ COMMAND specifies the name of an existing command that is being
+aliased.
+
+ The `-a' option specifies that the new alias is an abbreviation of
+the command. Abbreviations are not shown in command lists displayed by
+the `help' command.
+
+ The `--' option specifies the end of options, and is useful when
+ALIAS begins with a dash.
+
+ Here is a simple example showing how to make an abbreviation of a
+command so that there is less to type. Suppose you were tired of
+typing `disas', the current shortest unambiguous abbreviation of the
+`disassemble' command and you wanted an even shorter version named `di'.
+The following will accomplish this.
+
+ (gdb) alias -a di = disas
+
+ Note that aliases are different from user-defined commands. With a
+user-defined command, you also need to write documentation for it with
+the `document' command. An alias automatically picks up the
+documentation of the existing command.
+
+ Here is an example where we make `elms' an abbreviation of
+`elements' in the `set print elements' command. This is to show that
+you can make an abbreviation of any part of a command.
+
+ (gdb) alias -a set print elms = set print elements
+ (gdb) alias -a show print elms = show print elements
+ (gdb) set p elms 20
+ (gdb) show p elms
+ Limit on string chars or array elements to print is 200.
+
+ Note that if you are defining an alias of a `set' command, and you
+want to have an alias for the corresponding `show' command, then you
+need to define the latter separately.
+
+ Unambiguously abbreviated commands are allowed in COMMAND and ALIAS,
+just as they are normally.
+
+ (gdb) alias -a set pr elms = set p ele
+
+ Finally, here is an example showing the creation of a one word alias
+for a more complex command. This creates alias `spe' of the command
+`set print elements'.
+
+ (gdb) alias spe = set print elements
+ (gdb) spe 20
+
+
+File: gdb.info, Node: Interpreters, Next: TUI, Prev: Extending GDB, Up: Top
+
+24 Command Interpreters
+***********************
+
+GDB supports multiple command interpreters, and some command
+infrastructure to allow users or user interface writers to switch
+between interpreters or run commands in other interpreters.
+
+ GDB currently supports two command interpreters, the console
+interpreter (sometimes called the command-line interpreter or CLI) and
+the machine interface interpreter (or GDB/MI). This manual describes
+both of these interfaces in great detail.
+
+ By default, GDB will start with the console interpreter. However,
+the user may choose to start GDB with another interpreter by specifying
+the `-i' or `--interpreter' startup options. Defined interpreters
+include:
+
+`console'
+ The traditional console or command-line interpreter. This is the
+ most often used interpreter with GDB. With no interpreter
+ specified at runtime, GDB will use this interpreter.
+
+`mi'
+ The newest GDB/MI interface (currently `mi2'). Used primarily by
+ programs wishing to use GDB as a backend for a debugger GUI or an
+ IDE. For more information, see *Note The GDB/MI Interface: GDB/MI.
+
+`mi2'
+ The current GDB/MI interface.
+
+`mi1'
+ The GDB/MI interface included in GDB 5.1, 5.2, and 5.3.
+
+
+ The interpreter being used by GDB may not be dynamically switched at
+runtime. Although possible, this could lead to a very precarious
+situation. Consider an IDE using GDB/MI. If a user enters the command
+"interpreter-set console" in a console view, GDB would switch to using
+the console interpreter, rendering the IDE inoperable!
+
+ Although you may only choose a single interpreter at startup, you
+may execute commands in any interpreter from the current interpreter
+using the appropriate command. If you are running the console
+interpreter, simply use the `interpreter-exec' command:
+
+ interpreter-exec mi "-data-list-register-names"
+
+ GDB/MI has a similar command, although it is only available in
+versions of GDB which support GDB/MI version 2 (or greater).
+
+
+File: gdb.info, Node: TUI, Next: Emacs, Prev: Interpreters, Up: Top
+
+25 GDB Text User Interface
+**************************
+
+* Menu:
+
+* TUI Overview:: TUI overview
+* TUI Keys:: TUI key bindings
+* TUI Single Key Mode:: TUI single key mode
+* TUI Commands:: TUI-specific commands
+* TUI Configuration:: TUI configuration variables
+
+ The GDB Text User Interface (TUI) is a terminal interface which uses
+the `curses' library to show the source file, the assembly output, the
+program registers and GDB commands in separate text windows. The TUI
+mode is supported only on platforms where a suitable version of the
+`curses' library is available.
+
+ The TUI mode is enabled by default when you invoke GDB as either
+`gdbtui' or `gdb -tui'. You can also switch in and out of TUI mode
+while GDB runs by using various TUI commands and key bindings, such as
+`C-x C-a'. *Note TUI Key Bindings: TUI Keys.
+
+
+File: gdb.info, Node: TUI Overview, Next: TUI Keys, Up: TUI
+
+25.1 TUI Overview
+=================
+
+In TUI mode, GDB can display several text windows:
+
+_command_
+ This window is the GDB command window with the GDB prompt and the
+ GDB output. The GDB input is still managed using readline.
+
+_source_
+ The source window shows the source file of the program. The
+ current line and active breakpoints are displayed in this window.
+
+_assembly_
+ The assembly window shows the disassembly output of the program.
+
+_register_
+ This window shows the processor registers. Registers are
+ highlighted when their values change.
+
+ The source and assembly windows show the current program position by
+highlighting the current line and marking it with a `>' marker.
+Breakpoints are indicated with two markers. The first marker indicates
+the breakpoint type:
+
+`B'
+ Breakpoint which was hit at least once.
+
+`b'
+ Breakpoint which was never hit.
+
+`H'
+ Hardware breakpoint which was hit at least once.
+
+`h'
+ Hardware breakpoint which was never hit.
+
+ The second marker indicates whether the breakpoint is enabled or not:
+
+`+'
+ Breakpoint is enabled.
+
+`-'
+ Breakpoint is disabled.
+
+ The source, assembly and register windows are updated when the
+current thread changes, when the frame changes, or when the program
+counter changes.
+
+ These windows are not all visible at the same time. The command
+window is always visible. The others can be arranged in several
+layouts:
+
+ * source only,
+
+ * assembly only,
+
+ * source and assembly,
+
+ * source and registers, or
+
+ * assembly and registers.
+
+ A status line above the command window shows the following
+information:
+
+_target_
+ Indicates the current GDB target. (*note Specifying a Debugging
+ Target: Targets.).
+
+_process_
+ Gives the current process or thread number. When no process is
+ being debugged, this field is set to `No process'.
+
+_function_
+ Gives the current function name for the selected frame. The name
+ is demangled if demangling is turned on (*note Print Settings::).
+ When there is no symbol corresponding to the current program
+ counter, the string `??' is displayed.
+
+_line_
+ Indicates the current line number for the selected frame. When
+ the current line number is not known, the string `??' is displayed.
+
+_pc_
+ Indicates the current program counter address.
+
+
+File: gdb.info, Node: TUI Keys, Next: TUI Single Key Mode, Prev: TUI Overview, Up: TUI
+
+25.2 TUI Key Bindings
+=====================
+
+The TUI installs several key bindings in the readline keymaps (*note
+Command Line Editing::). The following key bindings are installed for
+both TUI mode and the GDB standard mode.
+
+`C-x C-a'
+`C-x a'
+`C-x A'
+ Enter or leave the TUI mode. When leaving the TUI mode, the
+ curses window management stops and GDB operates using its standard
+ mode, writing on the terminal directly. When reentering the TUI
+ mode, control is given back to the curses windows. The screen is
+ then refreshed.
+
+`C-x 1'
+ Use a TUI layout with only one window. The layout will either be
+ `source' or `assembly'. When the TUI mode is not active, it will
+ switch to the TUI mode.
+
+ Think of this key binding as the Emacs `C-x 1' binding.
+
+`C-x 2'
+ Use a TUI layout with at least two windows. When the current
+ layout already has two windows, the next layout with two windows
+ is used. When a new layout is chosen, one window will always be
+ common to the previous layout and the new one.
+
+ Think of it as the Emacs `C-x 2' binding.
+
+`C-x o'
+ Change the active window. The TUI associates several key bindings
+ (like scrolling and arrow keys) with the active window. This
+ command gives the focus to the next TUI window.
+
+ Think of it as the Emacs `C-x o' binding.
+
+`C-x s'
+ Switch in and out of the TUI SingleKey mode that binds single keys
+ to GDB commands (*note TUI Single Key Mode::).
+
+ The following key bindings only work in the TUI mode:
+
+<PgUp>
+ Scroll the active window one page up.
+
+<PgDn>
+ Scroll the active window one page down.
+
+<Up>
+ Scroll the active window one line up.
+
+<Down>
+ Scroll the active window one line down.
+
+<Left>
+ Scroll the active window one column left.
+
+<Right>
+ Scroll the active window one column right.
+
+`C-L'
+ Refresh the screen.
+
+ Because the arrow keys scroll the active window in the TUI mode, they
+are not available for their normal use by readline unless the command
+window has the focus. When another window is active, you must use
+other readline key bindings such as `C-p', `C-n', `C-b' and `C-f' to
+control the command window.
+
+
+File: gdb.info, Node: TUI Single Key Mode, Next: TUI Commands, Prev: TUI Keys, Up: TUI
+
+25.3 TUI Single Key Mode
+========================
+
+The TUI also provides a "SingleKey" mode, which binds several
+frequently used GDB commands to single keys. Type `C-x s' to switch
+into this mode, where the following key bindings are used:
+
+`c'
+ continue
+
+`d'
+ down
+
+`f'
+ finish
+
+`n'
+ next
+
+`q'
+ exit the SingleKey mode.
+
+`r'
+ run
+
+`s'
+ step
+
+`u'
+ up
+
+`v'
+ info locals
+
+`w'
+ where
+
+ Other keys temporarily switch to the GDB command prompt. The key
+that was pressed is inserted in the editing buffer so that it is
+possible to type most GDB commands without interaction with the TUI
+SingleKey mode. Once the command is entered the TUI SingleKey mode is
+restored. The only way to permanently leave this mode is by typing `q'
+or `C-x s'.
+
+
+File: gdb.info, Node: TUI Commands, Next: TUI Configuration, Prev: TUI Single Key Mode, Up: TUI
+
+25.4 TUI-specific Commands
+==========================
+
+The TUI has specific commands to control the text windows. These
+commands are always available, even when GDB is not in the TUI mode.
+When GDB is in the standard mode, most of these commands will
+automatically switch to the TUI mode.
+
+ Note that if GDB's `stdout' is not connected to a terminal, or GDB
+has been started with the machine interface interpreter (*note The
+GDB/MI Interface: GDB/MI.), most of these commands will fail with an
+error, because it would not be possible or desirable to enable curses
+window management.
+
+`info win'
+ List and give the size of all displayed windows.
+
+`layout next'
+ Display the next layout.
+
+`layout prev'
+ Display the previous layout.
+
+`layout src'
+ Display the source window only.
+
+`layout asm'
+ Display the assembly window only.
+
+`layout split'
+ Display the source and assembly window.
+
+`layout regs'
+ Display the register window together with the source or assembly
+ window.
+
+`focus next'
+ Make the next window active for scrolling.
+
+`focus prev'
+ Make the previous window active for scrolling.
+
+`focus src'
+ Make the source window active for scrolling.
+
+`focus asm'
+ Make the assembly window active for scrolling.
+
+`focus regs'
+ Make the register window active for scrolling.
+
+`focus cmd'
+ Make the command window active for scrolling.
+
+`refresh'
+ Refresh the screen. This is similar to typing `C-L'.
+
+`tui reg float'
+ Show the floating point registers in the register window.
+
+`tui reg general'
+ Show the general registers in the register window.
+
+`tui reg next'
+ Show the next register group. The list of register groups as well
+ as their order is target specific. The predefined register groups
+ are the following: `general', `float', `system', `vector', `all',
+ `save', `restore'.
+
+`tui reg system'
+ Show the system registers in the register window.
+
+`update'
+ Update the source window and the current execution point.
+
+`winheight NAME +COUNT'
+`winheight NAME -COUNT'
+ Change the height of the window NAME by COUNT lines. Positive
+ counts increase the height, while negative counts decrease it.
+
+`tabset NCHARS'
+ Set the width of tab stops to be NCHARS characters.
+
+
+File: gdb.info, Node: TUI Configuration, Prev: TUI Commands, Up: TUI
+
+25.5 TUI Configuration Variables
+================================
+
+Several configuration variables control the appearance of TUI windows.
+
+`set tui border-kind KIND'
+ Select the border appearance for the source, assembly and register
+ windows. The possible values are the following:
+ `space'
+ Use a space character to draw the border.
+
+ `ascii'
+ Use ASCII characters `+', `-' and `|' to draw the border.
+
+ `acs'
+ Use the Alternate Character Set to draw the border. The
+ border is drawn using character line graphics if the terminal
+ supports them.
+
+`set tui border-mode MODE'
+`set tui active-border-mode MODE'
+ Select the display attributes for the borders of the inactive
+ windows or the active window. The MODE can be one of the
+ following:
+ `normal'
+ Use normal attributes to display the border.
+
+ `standout'
+ Use standout mode.
+
+ `reverse'
+ Use reverse video mode.
+
+ `half'
+ Use half bright mode.
+
+ `half-standout'
+ Use half bright and standout mode.
+
+ `bold'
+ Use extra bright or bold mode.
+
+ `bold-standout'
+ Use extra bright or bold and standout mode.
+
+
+File: gdb.info, Node: Emacs, Next: GDB/MI, Prev: TUI, Up: Top
+
+26 Using GDB under GNU Emacs
+****************************
+
+A special interface allows you to use GNU Emacs to view (and edit) the
+source files for the program you are debugging with GDB.
+
+ To use this interface, use the command `M-x gdb' in Emacs. Give the
+executable file you want to debug as an argument. This command starts
+GDB as a subprocess of Emacs, with input and output through a newly
+created Emacs buffer.
+
+ Running GDB under Emacs can be just like running GDB normally except
+for two things:
+
+ * All "terminal" input and output goes through an Emacs buffer,
+ called the GUD buffer.
+
+ This applies both to GDB commands and their output, and to the
+ input and output done by the program you are debugging.
+
+ This is useful because it means that you can copy the text of
+ previous commands and input them again; you can even use parts of
+ the output in this way.
+
+ All the facilities of Emacs' Shell mode are available for
+ interacting with your program. In particular, you can send
+ signals the usual way--for example, `C-c C-c' for an interrupt,
+ `C-c C-z' for a stop.
+
+ * GDB displays source code through Emacs.
+
+ Each time GDB displays a stack frame, Emacs automatically finds the
+ source file for that frame and puts an arrow (`=>') at the left
+ margin of the current line. Emacs uses a separate buffer for
+ source display, and splits the screen to show both your GDB session
+ and the source.
+
+ Explicit GDB `list' or search commands still produce output as
+ usual, but you probably have no reason to use them from Emacs.
+
+ We call this "text command mode". Emacs 22.1, and later, also uses
+a graphical mode, enabled by default, which provides further buffers
+that can control the execution and describe the state of your program.
+*Note GDB Graphical Interface: (Emacs)GDB Graphical Interface.
+
+ If you specify an absolute file name when prompted for the `M-x gdb'
+argument, then Emacs sets your current working directory to where your
+program resides. If you only specify the file name, then Emacs sets
+your current working directory to the directory associated with the
+previous buffer. In this case, GDB may find your program by searching
+your environment's `PATH' variable, but on some operating systems it
+might not find the source. So, although the GDB input and output
+session proceeds normally, the auxiliary buffer does not display the
+current source and line of execution.
+
+ The initial working directory of GDB is printed on the top line of
+the GUD buffer and this serves as a default for the commands that
+specify files for GDB to operate on. *Note Commands to Specify Files:
+Files.
+
+ By default, `M-x gdb' calls the program called `gdb'. If you need
+to call GDB by a different name (for example, if you keep several
+configurations around, with different names) you can customize the
+Emacs variable `gud-gdb-command-name' to run the one you want.
+
+ In the GUD buffer, you can use these special Emacs commands in
+addition to the standard Shell mode commands:
+
+`C-h m'
+ Describe the features of Emacs' GUD Mode.
+
+`C-c C-s'
+ Execute to another source line, like the GDB `step' command; also
+ update the display window to show the current file and location.
+
+`C-c C-n'
+ Execute to next source line in this function, skipping all function
+ calls, like the GDB `next' command. Then update the display window
+ to show the current file and location.
+
+`C-c C-i'
+ Execute one instruction, like the GDB `stepi' command; update
+ display window accordingly.
+
+`C-c C-f'
+ Execute until exit from the selected stack frame, like the GDB
+ `finish' command.
+
+`C-c C-r'
+ Continue execution of your program, like the GDB `continue'
+ command.
+
+`C-c <'
+ Go up the number of frames indicated by the numeric argument
+ (*note Numeric Arguments: (Emacs)Arguments.), like the GDB `up'
+ command.
+
+`C-c >'
+ Go down the number of frames indicated by the numeric argument,
+ like the GDB `down' command.
+
+ In any source file, the Emacs command `C-x <SPC>' (`gud-break')
+tells GDB to set a breakpoint on the source line point is on.
+
+ In text command mode, if you type `M-x speedbar', Emacs displays a
+separate frame which shows a backtrace when the GUD buffer is current.
+Move point to any frame in the stack and type <RET> to make it become
+the current frame and display the associated source in the source
+buffer. Alternatively, click `Mouse-2' to make the selected frame
+become the current one. In graphical mode, the speedbar displays watch
+expressions.
+
+ If you accidentally delete the source-display buffer, an easy way to
+get it back is to type the command `f' in the GDB buffer, to request a
+frame display; when you run under Emacs, this recreates the source
+buffer if necessary to show you the context of the current frame.
+
+ The source files displayed in Emacs are in ordinary Emacs buffers
+which are visiting the source files in the usual way. You can edit the
+files with these buffers if you wish; but keep in mind that GDB
+communicates with Emacs in terms of line numbers. If you add or delete
+lines from the text, the line numbers that GDB knows cease to
+correspond properly with the code.
+
+ A more detailed description of Emacs' interaction with GDB is given
+in the Emacs manual (*note Debuggers: (Emacs)Debuggers.).
+
+
+File: gdb.info, Node: GDB/MI, Next: Annotations, Prev: Emacs, Up: Top
+
+27 The GDB/MI Interface
+***********************
+
+Function and Purpose
+====================
+
+GDB/MI is a line based machine oriented text interface to GDB and is
+activated by specifying using the `--interpreter' command line option
+(*note Mode Options::). It is specifically intended to support the
+development of systems which use the debugger as just one small
+component of a larger system.
+
+ This chapter is a specification of the GDB/MI interface. It is
+written in the form of a reference manual.
+
+ Note that GDB/MI is still under construction, so some of the
+features described below are incomplete and subject to change (*note
+GDB/MI Development and Front Ends: GDB/MI Development and Front Ends.).
+
+Notation and Terminology
+========================
+
+This chapter uses the following notation:
+
+ * `|' separates two alternatives.
+
+ * `[ SOMETHING ]' indicates that SOMETHING is optional: it may or
+ may not be given.
+
+ * `( GROUP )*' means that GROUP inside the parentheses may repeat
+ zero or more times.
+
+ * `( GROUP )+' means that GROUP inside the parentheses may repeat
+ one or more times.
+
+ * `"STRING"' means a literal STRING.
+
+* Menu:
+
+* GDB/MI General Design::
+* GDB/MI Command Syntax::
+* GDB/MI Compatibility with CLI::
+* GDB/MI Development and Front Ends::
+* GDB/MI Output Records::
+* GDB/MI Simple Examples::
+* GDB/MI Command Description Format::
+* GDB/MI Breakpoint Commands::
+* GDB/MI Program Context::
+* GDB/MI Thread Commands::
+* GDB/MI Ada Tasking Commands::
+* GDB/MI Program Execution::
+* GDB/MI Stack Manipulation::
+* GDB/MI Variable Objects::
+* GDB/MI Data Manipulation::
+* GDB/MI Tracepoint Commands::
+* GDB/MI Symbol Query::
+* GDB/MI File Commands::
+* GDB/MI Target Manipulation::
+* GDB/MI File Transfer Commands::
+* GDB/MI Miscellaneous Commands::
+
+
+File: gdb.info, Node: GDB/MI General Design, Next: GDB/MI Command Syntax, Up: GDB/MI
+
+27.1 GDB/MI General Design
+==========================
+
+Interaction of a GDB/MI frontend with GDB involves three
+parts--commands sent to GDB, responses to those commands and
+notifications. Each command results in exactly one response,
+indicating either successful completion of the command, or an error.
+For the commands that do not resume the target, the response contains
+the requested information. For the commands that resume the target, the
+response only indicates whether the target was successfully resumed.
+Notifications is the mechanism for reporting changes in the state of the
+target, or in GDB state, that cannot conveniently be associated with a
+command and reported as part of that command response.
+
+ The important examples of notifications are:
+ * Exec notifications. These are used to report changes in target
+ state--when a target is resumed, or stopped. It would not be
+ feasible to include this information in response of resuming
+ commands, because one resume commands can result in multiple
+ events in different threads. Also, quite some time may pass
+ before any event happens in the target, while a frontend needs to
+ know whether the resuming command itself was successfully executed.
+
+ * Console output, and status notifications. Console output
+ notifications are used to report output of CLI commands, as well as
+ diagnostics for other commands. Status notifications are used to
+ report the progress of a long-running operation. Naturally,
+ including this information in command response would mean no
+ output is produced until the command is finished, which is
+ undesirable.
+
+ * General notifications. Commands may have various side effects on
+ the GDB or target state beyond their official purpose. For
+ example, a command may change the selected thread. Although such
+ changes can be included in command response, using notification
+ allows for more orthogonal frontend design.
+
+
+ There's no guarantee that whenever an MI command reports an error,
+GDB or the target are in any specific state, and especially, the state
+is not reverted to the state before the MI command was processed.
+Therefore, whenever an MI command results in an error, we recommend
+that the frontend refreshes all the information shown in the user
+interface.
+
+* Menu:
+
+* Context management::
+* Asynchronous and non-stop modes::
+* Thread groups::
+
+
+File: gdb.info, Node: Context management, Next: Asynchronous and non-stop modes, Up: GDB/MI General Design
+
+27.1.1 Context management
+-------------------------
+
+In most cases when GDB accesses the target, this access is done in
+context of a specific thread and frame (*note Frames::). Often, even
+when accessing global data, the target requires that a thread be
+specified. The CLI interface maintains the selected thread and frame,
+and supplies them to target on each command. This is convenient,
+because a command line user would not want to specify that information
+explicitly on each command, and because user interacts with GDB via a
+single terminal, so no confusion is possible as to what thread and
+frame are the current ones.
+
+ In the case of MI, the concept of selected thread and frame is less
+useful. First, a frontend can easily remember this information itself.
+Second, a graphical frontend can have more than one window, each one
+used for debugging a different thread, and the frontend might want to
+access additional threads for internal purposes. This increases the
+risk that by relying on implicitly selected thread, the frontend may be
+operating on a wrong one. Therefore, each MI command should explicitly
+specify which thread and frame to operate on. To make it possible,
+each MI command accepts the `--thread' and `--frame' options, the value
+to each is GDB identifier for thread and frame to operate on.
+
+ Usually, each top-level window in a frontend allows the user to
+select a thread and a frame, and remembers the user selection for
+further operations. However, in some cases GDB may suggest that the
+current thread be changed. For example, when stopping on a breakpoint
+it is reasonable to switch to the thread where breakpoint is hit. For
+another example, if the user issues the CLI `thread' command via the
+frontend, it is desirable to change the frontend's selected thread to
+the one specified by user. GDB communicates the suggestion to change
+current thread using the `=thread-selected' notification. No such
+notification is available for the selected frame at the moment.
+
+ Note that historically, MI shares the selected thread with CLI, so
+frontends used the `-thread-select' to execute commands in the right
+context. However, getting this to work right is cumbersome. The
+simplest way is for frontend to emit `-thread-select' command before
+every command. This doubles the number of commands that need to be
+sent. The alternative approach is to suppress `-thread-select' if the
+selected thread in GDB is supposed to be identical to the thread the
+frontend wants to operate on. However, getting this optimization right
+can be tricky. In particular, if the frontend sends several commands
+to GDB, and one of the commands changes the selected thread, then the
+behaviour of subsequent commands will change. So, a frontend should
+either wait for response from such problematic commands, or explicitly
+add `-thread-select' for all subsequent commands. No frontend is known
+to do this exactly right, so it is suggested to just always pass the
+`--thread' and `--frame' options.
+
+
+File: gdb.info, Node: Asynchronous and non-stop modes, Next: Thread groups, Prev: Context management, Up: GDB/MI General Design
+
+27.1.2 Asynchronous command execution and non-stop mode
+-------------------------------------------------------
+
+On some targets, GDB is capable of processing MI commands even while
+the target is running. This is called "asynchronous command execution"
+(*note Background Execution::). The frontend may specify a preferrence
+for asynchronous execution using the `-gdb-set target-async 1' command,
+which should be emitted before either running the executable or
+attaching to the target. After the frontend has started the executable
+or attached to the target, it can find if asynchronous execution is
+enabled using the `-list-target-features' command.
+
+ Even if GDB can accept a command while target is running, many
+commands that access the target do not work when the target is running.
+Therefore, asynchronous command execution is most useful when combined
+with non-stop mode (*note Non-Stop Mode::). Then, it is possible to
+examine the state of one thread, while other threads are running.
+
+ When a given thread is running, MI commands that try to access the
+target in the context of that thread may not work, or may work only on
+some targets. In particular, commands that try to operate on thread's
+stack will not work, on any target. Commands that read memory, or
+modify breakpoints, may work or not work, depending on the target. Note
+that even commands that operate on global state, such as `print',
+`set', and breakpoint commands, still access the target in the context
+of a specific thread, so frontend should try to find a stopped thread
+and perform the operation on that thread (using the `--thread' option).
+
+ Which commands will work in the context of a running thread is
+highly target dependent. However, the two commands `-exec-interrupt',
+to stop a thread, and `-thread-info', to find the state of a thread,
+will always work.
+
+
+File: gdb.info, Node: Thread groups, Prev: Asynchronous and non-stop modes, Up: GDB/MI General Design
+
+27.1.3 Thread groups
+--------------------
+
+GDB may be used to debug several processes at the same time. On some
+platfroms, GDB may support debugging of several hardware systems, each
+one having several cores with several different processes running on
+each core. This section describes the MI mechanism to support such
+debugging scenarios.
+
+ The key observation is that regardless of the structure of the
+target, MI can have a global list of threads, because most commands that
+accept the `--thread' option do not need to know what process that
+thread belongs to. Therefore, it is not necessary to introduce neither
+additional `--process' option, nor an notion of the current process in
+the MI interface. The only strictly new feature that is required is
+the ability to find how the threads are grouped into processes.
+
+ To allow the user to discover such grouping, and to support arbitrary
+hierarchy of machines/cores/processes, MI introduces the concept of a
+"thread group". Thread group is a collection of threads and other
+thread groups. A thread group always has a string identifier, a type,
+and may have additional attributes specific to the type. A new
+command, `-list-thread-groups', returns the list of top-level thread
+groups, which correspond to processes that GDB is debugging at the
+moment. By passing an identifier of a thread group to the
+`-list-thread-groups' command, it is possible to obtain the members of
+specific thread group.
+
+ To allow the user to easily discover processes, and other objects, he
+wishes to debug, a concept of "available thread group" is introduced.
+Available thread group is an thread group that GDB is not debugging,
+but that can be attached to, using the `-target-attach' command. The
+list of available top-level thread groups can be obtained using
+`-list-thread-groups --available'. In general, the content of a thread
+group may be only retrieved only after attaching to that thread group.
+
+ Thread groups are related to inferiors (*note Inferiors and
+Programs::). Each inferior corresponds to a thread group of a special
+type `process', and some additional operations are permitted on such
+thread groups.
+
+
+File: gdb.info, Node: GDB/MI Command Syntax, Next: GDB/MI Compatibility with CLI, Prev: GDB/MI General Design, Up: GDB/MI
+
+27.2 GDB/MI Command Syntax
+==========================
+
+* Menu:
+
+* GDB/MI Input Syntax::
+* GDB/MI Output Syntax::
+
+
+File: gdb.info, Node: GDB/MI Input Syntax, Next: GDB/MI Output Syntax, Up: GDB/MI Command Syntax
+
+27.2.1 GDB/MI Input Syntax
+--------------------------
+
+`COMMAND ==>'
+ `CLI-COMMAND | MI-COMMAND'
+
+`CLI-COMMAND ==>'
+ `[ TOKEN ] CLI-COMMAND NL', where CLI-COMMAND is any existing GDB
+ CLI command.
+
+`MI-COMMAND ==>'
+ `[ TOKEN ] "-" OPERATION ( " " OPTION )* `[' " --" `]' ( " "
+ PARAMETER )* NL'
+
+`TOKEN ==>'
+ "any sequence of digits"
+
+`OPTION ==>'
+ `"-" PARAMETER [ " " PARAMETER ]'
+
+`PARAMETER ==>'
+ `NON-BLANK-SEQUENCE | C-STRING'
+
+`OPERATION ==>'
+ _any of the operations described in this chapter_
+
+`NON-BLANK-SEQUENCE ==>'
+ _anything, provided it doesn't contain special characters such as
+ "-", NL, """ and of course " "_
+
+`C-STRING ==>'
+ `""" SEVEN-BIT-ISO-C-STRING-CONTENT """'
+
+`NL ==>'
+ `CR | CR-LF'
+
+Notes:
+
+ * The CLI commands are still handled by the MI interpreter; their
+ output is described below.
+
+ * The `TOKEN', when present, is passed back when the command
+ finishes.
+
+ * Some MI commands accept optional arguments as part of the parameter
+ list. Each option is identified by a leading `-' (dash) and may be
+ followed by an optional argument parameter. Options occur first
+ in the parameter list and can be delimited from normal parameters
+ using `--' (this is useful when some parameters begin with a dash).
+
+ Pragmatics:
+
+ * We want easy access to the existing CLI syntax (for debugging).
+
+ * We want it to be easy to spot a MI operation.
+
diff --git a/gdb/doc/gdb.info-4 b/gdb/doc/gdb.info-4
new file mode 100644
index 0000000..ed5c1bc
--- /dev/null
+++ b/gdb/doc/gdb.info-4
@@ -0,0 +1,8861 @@
+This is gdb.info, produced by makeinfo version 4.8 from ./gdb.texinfo.
+
+INFO-DIR-SECTION Software development
+START-INFO-DIR-ENTRY
+* Gdb: (gdb). The GNU debugger.
+END-INFO-DIR-ENTRY
+
+ Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996,
+1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009,
+2010 Free Software Foundation, Inc.
+
+ Permission is granted to copy, distribute and/or modify this document
+under the terms of the GNU Free Documentation License, Version 1.3 or
+any later version published by the Free Software Foundation; with the
+Invariant Sections being "Free Software" and "Free Software Needs Free
+Documentation", with the Front-Cover Texts being "A GNU Manual," and
+with the Back-Cover Texts as in (a) below.
+
+ (a) The FSF's Back-Cover Text is: "You are free to copy and modify
+this GNU Manual. Buying copies from GNU Press supports the FSF in
+developing GNU and promoting software freedom."
+
+ This file documents the GNU debugger GDB.
+
+ This is the Tenth Edition, of `Debugging with GDB: the GNU
+Source-Level Debugger' for GDB (GDB) Version 7.4.1.
+
+ Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996,
+1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009,
+2010 Free Software Foundation, Inc.
+
+ Permission is granted to copy, distribute and/or modify this document
+under the terms of the GNU Free Documentation License, Version 1.3 or
+any later version published by the Free Software Foundation; with the
+Invariant Sections being "Free Software" and "Free Software Needs Free
+Documentation", with the Front-Cover Texts being "A GNU Manual," and
+with the Back-Cover Texts as in (a) below.
+
+ (a) The FSF's Back-Cover Text is: "You are free to copy and modify
+this GNU Manual. Buying copies from GNU Press supports the FSF in
+developing GNU and promoting software freedom."
+
+
+File: gdb.info, Node: GDB/MI Output Syntax, Prev: GDB/MI Input Syntax, Up: GDB/MI Command Syntax
+
+27.2.2 GDB/MI Output Syntax
+---------------------------
+
+The output from GDB/MI consists of zero or more out-of-band records
+followed, optionally, by a single result record. This result record is
+for the most recent command. The sequence of output records is
+terminated by `(gdb)'.
+
+ If an input command was prefixed with a `TOKEN' then the
+corresponding output for that command will also be prefixed by that same
+TOKEN.
+
+`OUTPUT ==>'
+ `( OUT-OF-BAND-RECORD )* [ RESULT-RECORD ] "(gdb)" NL'
+
+`RESULT-RECORD ==>'
+ ` [ TOKEN ] "^" RESULT-CLASS ( "," RESULT )* NL'
+
+`OUT-OF-BAND-RECORD ==>'
+ `ASYNC-RECORD | STREAM-RECORD'
+
+`ASYNC-RECORD ==>'
+ `EXEC-ASYNC-OUTPUT | STATUS-ASYNC-OUTPUT | NOTIFY-ASYNC-OUTPUT'
+
+`EXEC-ASYNC-OUTPUT ==>'
+ `[ TOKEN ] "*" ASYNC-OUTPUT'
+
+`STATUS-ASYNC-OUTPUT ==>'
+ `[ TOKEN ] "+" ASYNC-OUTPUT'
+
+`NOTIFY-ASYNC-OUTPUT ==>'
+ `[ TOKEN ] "=" ASYNC-OUTPUT'
+
+`ASYNC-OUTPUT ==>'
+ `ASYNC-CLASS ( "," RESULT )* NL'
+
+`RESULT-CLASS ==>'
+ `"done" | "running" | "connected" | "error" | "exit"'
+
+`ASYNC-CLASS ==>'
+ `"stopped" | OTHERS' (where OTHERS will be added depending on the
+ needs--this is still in development).
+
+`RESULT ==>'
+ ` VARIABLE "=" VALUE'
+
+`VARIABLE ==>'
+ ` STRING '
+
+`VALUE ==>'
+ ` CONST | TUPLE | LIST '
+
+`CONST ==>'
+ `C-STRING'
+
+`TUPLE ==>'
+ ` "{}" | "{" RESULT ( "," RESULT )* "}" '
+
+`LIST ==>'
+ ` "[]" | "[" VALUE ( "," VALUE )* "]" | "[" RESULT ( "," RESULT )*
+ "]" '
+
+`STREAM-RECORD ==>'
+ `CONSOLE-STREAM-OUTPUT | TARGET-STREAM-OUTPUT | LOG-STREAM-OUTPUT'
+
+`CONSOLE-STREAM-OUTPUT ==>'
+ `"~" C-STRING'
+
+`TARGET-STREAM-OUTPUT ==>'
+ `"@" C-STRING'
+
+`LOG-STREAM-OUTPUT ==>'
+ `"&" C-STRING'
+
+`NL ==>'
+ `CR | CR-LF'
+
+`TOKEN ==>'
+ _any sequence of digits_.
+
+Notes:
+
+ * All output sequences end in a single line containing a period.
+
+ * The `TOKEN' is from the corresponding request. Note that for all
+ async output, while the token is allowed by the grammar and may be
+ output by future versions of GDB for select async output messages,
+ it is generally omitted. Frontends should treat all async output
+ as reporting general changes in the state of the target and there
+ should be no need to associate async output to any prior command.
+
+ * STATUS-ASYNC-OUTPUT contains on-going status information about the
+ progress of a slow operation. It can be discarded. All status
+ output is prefixed by `+'.
+
+ * EXEC-ASYNC-OUTPUT contains asynchronous state change on the target
+ (stopped, started, disappeared). All async output is prefixed by
+ `*'.
+
+ * NOTIFY-ASYNC-OUTPUT contains supplementary information that the
+ client should handle (e.g., a new breakpoint information). All
+ notify output is prefixed by `='.
+
+ * CONSOLE-STREAM-OUTPUT is output that should be displayed as is in
+ the console. It is the textual response to a CLI command. All
+ the console output is prefixed by `~'.
+
+ * TARGET-STREAM-OUTPUT is the output produced by the target program.
+ All the target output is prefixed by `@'.
+
+ * LOG-STREAM-OUTPUT is output text coming from GDB's internals, for
+ instance messages that should be displayed as part of an error
+ log. All the log output is prefixed by `&'.
+
+ * New GDB/MI commands should only output LISTS containing VALUES.
+
+
+ *Note GDB/MI Stream Records: GDB/MI Stream Records, for more details
+about the various output records.
+
+
+File: gdb.info, Node: GDB/MI Compatibility with CLI, Next: GDB/MI Development and Front Ends, Prev: GDB/MI Command Syntax, Up: GDB/MI
+
+27.3 GDB/MI Compatibility with CLI
+==================================
+
+For the developers convenience CLI commands can be entered directly,
+but there may be some unexpected behaviour. For example, commands that
+query the user will behave as if the user replied yes, breakpoint
+command lists are not executed and some CLI commands, such as `if',
+`when' and `define', prompt for further input with `>', which is not
+valid MI output.
+
+ This feature may be removed at some stage in the future and it is
+recommended that front ends use the `-interpreter-exec' command (*note
+-interpreter-exec::).
+
+
+File: gdb.info, Node: GDB/MI Development and Front Ends, Next: GDB/MI Output Records, Prev: GDB/MI Compatibility with CLI, Up: GDB/MI
+
+27.4 GDB/MI Development and Front Ends
+======================================
+
+The application which takes the MI output and presents the state of the
+program being debugged to the user is called a "front end".
+
+ Although GDB/MI is still incomplete, it is currently being used by a
+variety of front ends to GDB. This makes it difficult to introduce new
+functionality without breaking existing usage. This section tries to
+minimize the problems by describing how the protocol might change.
+
+ Some changes in MI need not break a carefully designed front end, and
+for these the MI version will remain unchanged. The following is a
+list of changes that may occur within one level, so front ends should
+parse MI output in a way that can handle them:
+
+ * New MI commands may be added.
+
+ * New fields may be added to the output of any MI command.
+
+ * The range of values for fields with specified values, e.g.,
+ `in_scope' (*note -var-update::) may be extended.
+
+
+ If the changes are likely to break front ends, the MI version level
+will be increased by one. This will allow the front end to parse the
+output according to the MI version. Apart from mi0, new versions of
+GDB will not support old versions of MI and it will be the
+responsibility of the front end to work with the new one.
+
+ The best way to avoid unexpected changes in MI that might break your
+front end is to make your project known to GDB developers and follow
+development on <gdb@sourceware.org> and <gdb-patches@sourceware.org>.
+
+
+File: gdb.info, Node: GDB/MI Output Records, Next: GDB/MI Simple Examples, Prev: GDB/MI Development and Front Ends, Up: GDB/MI
+
+27.5 GDB/MI Output Records
+==========================
+
+* Menu:
+
+* GDB/MI Result Records::
+* GDB/MI Stream Records::
+* GDB/MI Async Records::
+* GDB/MI Frame Information::
+* GDB/MI Thread Information::
+* GDB/MI Ada Exception Information::
+
+
+File: gdb.info, Node: GDB/MI Result Records, Next: GDB/MI Stream Records, Up: GDB/MI Output Records
+
+27.5.1 GDB/MI Result Records
+----------------------------
+
+In addition to a number of out-of-band notifications, the response to a
+GDB/MI command includes one of the following result indications:
+
+`"^done" [ "," RESULTS ]'
+ The synchronous operation was successful, `RESULTS' are the return
+ values.
+
+`"^running"'
+ This result record is equivalent to `^done'. Historically, it was
+ output instead of `^done' if the command has resumed the target.
+ This behaviour is maintained for backward compatibility, but all
+ frontends should treat `^done' and `^running' identically and rely
+ on the `*running' output record to determine which threads are
+ resumed.
+
+`"^connected"'
+ GDB has connected to a remote target.
+
+`"^error" "," C-STRING'
+ The operation failed. The `C-STRING' contains the corresponding
+ error message.
+
+`"^exit"'
+ GDB has terminated.
+
+
+
+File: gdb.info, Node: GDB/MI Stream Records, Next: GDB/MI Async Records, Prev: GDB/MI Result Records, Up: GDB/MI Output Records
+
+27.5.2 GDB/MI Stream Records
+----------------------------
+
+GDB internally maintains a number of output streams: the console, the
+target, and the log. The output intended for each of these streams is
+funneled through the GDB/MI interface using "stream records".
+
+ Each stream record begins with a unique "prefix character" which
+identifies its stream (*note GDB/MI Output Syntax: GDB/MI Output
+Syntax.). In addition to the prefix, each stream record contains a
+`STRING-OUTPUT'. This is either raw text (with an implicit new line)
+or a quoted C string (which does not contain an implicit newline).
+
+`"~" STRING-OUTPUT'
+ The console output stream contains text that should be displayed
+ in the CLI console window. It contains the textual responses to
+ CLI commands.
+
+`"@" STRING-OUTPUT'
+ The target output stream contains any textual output from the
+ running target. This is only present when GDB's event loop is
+ truly asynchronous, which is currently only the case for remote
+ targets.
+
+`"&" STRING-OUTPUT'
+ The log stream contains debugging messages being produced by GDB's
+ internals.
+
+
+File: gdb.info, Node: GDB/MI Async Records, Next: GDB/MI Frame Information, Prev: GDB/MI Stream Records, Up: GDB/MI Output Records
+
+27.5.3 GDB/MI Async Records
+---------------------------
+
+"Async" records are used to notify the GDB/MI client of additional
+changes that have occurred. Those changes can either be a consequence
+of GDB/MI commands (e.g., a breakpoint modified) or a result of target
+activity (e.g., target stopped).
+
+ The following is the list of possible async records:
+
+`*running,thread-id="THREAD"'
+ The target is now running. The THREAD field tells which specific
+ thread is now running, and can be `all' if all threads are
+ running. The frontend should assume that no interaction with a
+ running thread is possible after this notification is produced.
+ The frontend should not assume that this notification is output
+ only once for any command. GDB may emit this notification several
+ times, either for different threads, because it cannot resume all
+ threads together, or even for a single thread, if the thread must
+ be stepped though some code before letting it run freely.
+
+`*stopped,reason="REASON",thread-id="ID",stopped-threads="STOPPED",core="CORE"'
+ The target has stopped. The REASON field can have one of the
+ following values:
+
+ `breakpoint-hit'
+ A breakpoint was reached.
+
+ `watchpoint-trigger'
+ A watchpoint was triggered.
+
+ `read-watchpoint-trigger'
+ A read watchpoint was triggered.
+
+ `access-watchpoint-trigger'
+ An access watchpoint was triggered.
+
+ `function-finished'
+ An -exec-finish or similar CLI command was accomplished.
+
+ `location-reached'
+ An -exec-until or similar CLI command was accomplished.
+
+ `watchpoint-scope'
+ A watchpoint has gone out of scope.
+
+ `end-stepping-range'
+ An -exec-next, -exec-next-instruction, -exec-step,
+ -exec-step-instruction or similar CLI command was
+ accomplished.
+
+ `exited-signalled'
+ The inferior exited because of a signal.
+
+ `exited'
+ The inferior exited.
+
+ `exited-normally'
+ The inferior exited normally.
+
+ `signal-received'
+ A signal was received by the inferior.
+
+ `solib-event'
+ The inferior has stopped due to a library being loaded or
+ unloaded. This can only happen when `stop-on-solib-events'
+ (*note Files::) is set.
+
+ `fork'
+ The inferior has forked. This is reported when `catch fork'
+ (*note Set Catchpoints::) has been used.
+
+ `vfork'
+ The inferior has vforked. This is reported in when `catch
+ vfork' (*note Set Catchpoints::) has been used.
+
+ `syscall-entry'
+ The inferior entered a system call. This is reported when
+ `catch syscall' (*note Set Catchpoints::) has been used.
+
+ `syscall-entry'
+ The inferior returned from a system call. This is reported
+ when `catch syscall' (*note Set Catchpoints::) has been used.
+
+ `exec'
+ The inferior called `exec'. This is reported when `catch
+ exec' (*note Set Catchpoints::) has been used.
+
+ The ID field identifies the thread that directly caused the stop -
+ for example by hitting a breakpoint. Depending on whether all-stop
+ mode is in effect (*note All-Stop Mode::), GDB may either stop all
+ threads, or only the thread that directly triggered the stop. If
+ all threads are stopped, the STOPPED field will have the value of
+ `"all"'. Otherwise, the value of the STOPPED field will be a list
+ of thread identifiers. Presently, this list will always include a
+ single thread, but frontend should be prepared to see several
+ threads in the list. The CORE field reports the processor core on
+ which the stop event has happened. This field may be absent if
+ such information is not available.
+
+`=thread-group-added,id="ID"'
+`=thread-group-removed,id="ID"'
+ A thread group was either added or removed. The ID field contains
+ the GDB identifier of the thread group. When a thread group is
+ added, it generally might not be associated with a running
+ process. When a thread group is removed, its id becomes invalid
+ and cannot be used in any way.
+
+`=thread-group-started,id="ID",pid="PID"'
+ A thread group became associated with a running program, either
+ because the program was just started or the thread group was
+ attached to a program. The ID field contains the GDB identifier
+ of the thread group. The PID field contains process identifier,
+ specific to the operating system.
+
+`=thread-group-exited,id="ID"[,exit-code="CODE"]'
+ A thread group is no longer associated with a running program,
+ either because the program has exited, or because it was detached
+ from. The ID field contains the GDB identifier of the thread
+ group. CODE is the exit code of the inferior; it exists only when
+ the inferior exited with some code.
+
+`=thread-created,id="ID",group-id="GID"'
+`=thread-exited,id="ID",group-id="GID"'
+ A thread either was created, or has exited. The ID field contains
+ the GDB identifier of the thread. The GID field identifies the
+ thread group this thread belongs to.
+
+`=thread-selected,id="ID"'
+ Informs that the selected thread was changed as result of the last
+ command. This notification is not emitted as result of
+ `-thread-select' command but is emitted whenever an MI command
+ that is not documented to change the selected thread actually
+ changes it. In particular, invoking, directly or indirectly (via
+ user-defined command), the CLI `thread' command, will generate
+ this notification.
+
+ We suggest that in response to this notification, front ends
+ highlight the selected thread and cause subsequent commands to
+ apply to that thread.
+
+`=library-loaded,...'
+ Reports that a new library file was loaded by the program. This
+ notification has 4 fields--ID, TARGET-NAME, HOST-NAME, and
+ SYMBOLS-LOADED. The ID field is an opaque identifier of the
+ library. For remote debugging case, TARGET-NAME and HOST-NAME
+ fields give the name of the library file on the target, and on the
+ host respectively. For native debugging, both those fields have
+ the same value. The SYMBOLS-LOADED field is emitted only for
+ backward compatibility and should not be relied on to convey any
+ useful information. The THREAD-GROUP field, if present, specifies
+ the id of the thread group in whose context the library was
+ loaded. If the field is absent, it means the library was loaded
+ in the context of all present thread groups.
+
+`=library-unloaded,...'
+ Reports that a library was unloaded by the program. This
+ notification has 3 fields--ID, TARGET-NAME and HOST-NAME with the
+ same meaning as for the `=library-loaded' notification. The
+ THREAD-GROUP field, if present, specifies the id of the thread
+ group in whose context the library was unloaded. If the field is
+ absent, it means the library was unloaded in the context of all
+ present thread groups.
+
+`=breakpoint-created,bkpt={...}'
+`=breakpoint-modified,bkpt={...}'
+`=breakpoint-deleted,bkpt={...}'
+ Reports that a breakpoint was created, modified, or deleted,
+ respectively. Only user-visible breakpoints are reported to the MI
+ user.
+
+ The BKPT argument is of the same form as returned by the various
+ breakpoint commands; *Note GDB/MI Breakpoint Commands::.
+
+ Note that if a breakpoint is emitted in the result record of a
+ command, then it will not also be emitted in an async record.
+
+
+
+File: gdb.info, Node: GDB/MI Frame Information, Next: GDB/MI Thread Information, Prev: GDB/MI Async Records, Up: GDB/MI Output Records
+
+27.5.4 GDB/MI Frame Information
+-------------------------------
+
+Response from many MI commands includes an information about stack
+frame. This information is a tuple that may have the following fields:
+
+`level'
+ The level of the stack frame. The innermost frame has the level of
+ zero. This field is always present.
+
+`func'
+ The name of the function corresponding to the frame. This field
+ may be absent if GDB is unable to determine the function name.
+
+`addr'
+ The code address for the frame. This field is always present.
+
+`file'
+ The name of the source files that correspond to the frame's code
+ address. This field may be absent.
+
+`line'
+ The source line corresponding to the frames' code address. This
+ field may be absent.
+
+`from'
+ The name of the binary file (either executable or shared library)
+ the corresponds to the frame's code address. This field may be
+ absent.
+
+
+
+File: gdb.info, Node: GDB/MI Thread Information, Next: GDB/MI Ada Exception Information, Prev: GDB/MI Frame Information, Up: GDB/MI Output Records
+
+27.5.5 GDB/MI Thread Information
+--------------------------------
+
+Whenever GDB has to report an information about a thread, it uses a
+tuple with the following fields:
+
+`id'
+ The numeric id assigned to the thread by GDB. This field is
+ always present.
+
+`target-id'
+ Target-specific string identifying the thread. This field is
+ always present.
+
+`details'
+ Additional information about the thread provided by the target.
+ It is supposed to be human-readable and not interpreted by the
+ frontend. This field is optional.
+
+`state'
+ Either `stopped' or `running', depending on whether the thread is
+ presently running. This field is always present.
+
+`core'
+ The value of this field is an integer number of the processor core
+ the thread was last seen on. This field is optional.
+
+
+File: gdb.info, Node: GDB/MI Ada Exception Information, Prev: GDB/MI Thread Information, Up: GDB/MI Output Records
+
+27.5.6 GDB/MI Ada Exception Information
+---------------------------------------
+
+Whenever a `*stopped' record is emitted because the program stopped
+after hitting an exception catchpoint (*note Set Catchpoints::), GDB
+provides the name of the exception that was raised via the
+`exception-name' field.
+
+
+File: gdb.info, Node: GDB/MI Simple Examples, Next: GDB/MI Command Description Format, Prev: GDB/MI Output Records, Up: GDB/MI
+
+27.6 Simple Examples of GDB/MI Interaction
+==========================================
+
+This subsection presents several simple examples of interaction using
+the GDB/MI interface. In these examples, `->' means that the following
+line is passed to GDB/MI as input, while `<-' means the output received
+from GDB/MI.
+
+ Note the line breaks shown in the examples are here only for
+readability, they don't appear in the real output.
+
+Setting a Breakpoint
+--------------------
+
+Setting a breakpoint generates synchronous output which contains
+detailed information of the breakpoint.
+
+ -> -break-insert main
+ <- ^done,bkpt={number="1",type="breakpoint",disp="keep",
+ enabled="y",addr="0x08048564",func="main",file="myprog.c",
+ fullname="/home/nickrob/myprog.c",line="68",times="0"}
+ <- (gdb)
+
+Program Execution
+-----------------
+
+Program execution generates asynchronous records and MI gives the
+reason that execution stopped.
+
+ -> -exec-run
+ <- ^running
+ <- (gdb)
+ <- *stopped,reason="breakpoint-hit",disp="keep",bkptno="1",thread-id="0",
+ frame={addr="0x08048564",func="main",
+ args=[{name="argc",value="1"},{name="argv",value="0xbfc4d4d4"}],
+ file="myprog.c",fullname="/home/nickrob/myprog.c",line="68"}
+ <- (gdb)
+ -> -exec-continue
+ <- ^running
+ <- (gdb)
+ <- *stopped,reason="exited-normally"
+ <- (gdb)
+
+Quitting GDB
+------------
+
+Quitting GDB just prints the result class `^exit'.
+
+ -> (gdb)
+ <- -gdb-exit
+ <- ^exit
+
+ Please note that `^exit' is printed immediately, but it might take
+some time for GDB to actually exit. During that time, GDB performs
+necessary cleanups, including killing programs being debugged or
+disconnecting from debug hardware, so the frontend should wait till GDB
+exits and should only forcibly kill GDB if it fails to exit in
+reasonable time.
+
+A Bad Command
+-------------
+
+Here's what happens if you pass a non-existent command:
+
+ -> -rubbish
+ <- ^error,msg="Undefined MI command: rubbish"
+ <- (gdb)
+
+
+File: gdb.info, Node: GDB/MI Command Description Format, Next: GDB/MI Breakpoint Commands, Prev: GDB/MI Simple Examples, Up: GDB/MI
+
+27.7 GDB/MI Command Description Format
+======================================
+
+The remaining sections describe blocks of commands. Each block of
+commands is laid out in a fashion similar to this section.
+
+Motivation
+----------
+
+The motivation for this collection of commands.
+
+Introduction
+------------
+
+A brief introduction to this collection of commands as a whole.
+
+Commands
+--------
+
+For each command in the block, the following is described:
+
+Synopsis
+........
+
+ -command ARGS...
+
+Result
+......
+
+GDB Command
+...........
+
+The corresponding GDB CLI command(s), if any.
+
+Example
+.......
+
+Example(s) formatted for readability. Some of the described commands
+have not been implemented yet and these are labeled N.A. (not
+available).
+
+
+File: gdb.info, Node: GDB/MI Breakpoint Commands, Next: GDB/MI Program Context, Prev: GDB/MI Command Description Format, Up: GDB/MI
+
+27.8 GDB/MI Breakpoint Commands
+===============================
+
+This section documents GDB/MI commands for manipulating breakpoints.
+
+The `-break-after' Command
+--------------------------
+
+Synopsis
+........
+
+ -break-after NUMBER COUNT
+
+ The breakpoint number NUMBER is not in effect until it has been hit
+COUNT times. To see how this is reflected in the output of the
+`-break-list' command, see the description of the `-break-list' command
+below.
+
+GDB Command
+...........
+
+The corresponding GDB command is `ignore'.
+
+Example
+.......
+
+ (gdb)
+ -break-insert main
+ ^done,bkpt={number="1",type="breakpoint",disp="keep",
+ enabled="y",addr="0x000100d0",func="main",file="hello.c",
+ fullname="/home/foo/hello.c",line="5",times="0"}
+ (gdb)
+ -break-after 1 3
+ ~
+ ^done
+ (gdb)
+ -break-list
+ ^done,BreakpointTable={nr_rows="1",nr_cols="6",
+ hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"},
+ {width="14",alignment="-1",col_name="type",colhdr="Type"},
+ {width="4",alignment="-1",col_name="disp",colhdr="Disp"},
+ {width="3",alignment="-1",col_name="enabled",colhdr="Enb"},
+ {width="10",alignment="-1",col_name="addr",colhdr="Address"},
+ {width="40",alignment="2",col_name="what",colhdr="What"}],
+ body=[bkpt={number="1",type="breakpoint",disp="keep",enabled="y",
+ addr="0x000100d0",func="main",file="hello.c",fullname="/home/foo/hello.c",
+ line="5",times="0",ignore="3"}]}
+ (gdb)
+
+The `-break-commands' Command
+-----------------------------
+
+Synopsis
+........
+
+ -break-commands NUMBER [ COMMAND1 ... COMMANDN ]
+
+ Specifies the CLI commands that should be executed when breakpoint
+NUMBER is hit. The parameters COMMAND1 to COMMANDN are the commands.
+If no command is specified, any previously-set commands are cleared.
+*Note Break Commands::. Typical use of this functionality is tracing a
+program, that is, printing of values of some variables whenever
+breakpoint is hit and then continuing.
+
+GDB Command
+...........
+
+The corresponding GDB command is `commands'.
+
+Example
+.......
+
+ (gdb)
+ -break-insert main
+ ^done,bkpt={number="1",type="breakpoint",disp="keep",
+ enabled="y",addr="0x000100d0",func="main",file="hello.c",
+ fullname="/home/foo/hello.c",line="5",times="0"}
+ (gdb)
+ -break-commands 1 "print v" "continue"
+ ^done
+ (gdb)
+
+The `-break-condition' Command
+------------------------------
+
+Synopsis
+........
+
+ -break-condition NUMBER EXPR
+
+ Breakpoint NUMBER will stop the program only if the condition in
+EXPR is true. The condition becomes part of the `-break-list' output
+(see the description of the `-break-list' command below).
+
+GDB Command
+...........
+
+The corresponding GDB command is `condition'.
+
+Example
+.......
+
+ (gdb)
+ -break-condition 1 1
+ ^done
+ (gdb)
+ -break-list
+ ^done,BreakpointTable={nr_rows="1",nr_cols="6",
+ hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"},
+ {width="14",alignment="-1",col_name="type",colhdr="Type"},
+ {width="4",alignment="-1",col_name="disp",colhdr="Disp"},
+ {width="3",alignment="-1",col_name="enabled",colhdr="Enb"},
+ {width="10",alignment="-1",col_name="addr",colhdr="Address"},
+ {width="40",alignment="2",col_name="what",colhdr="What"}],
+ body=[bkpt={number="1",type="breakpoint",disp="keep",enabled="y",
+ addr="0x000100d0",func="main",file="hello.c",fullname="/home/foo/hello.c",
+ line="5",cond="1",times="0",ignore="3"}]}
+ (gdb)
+
+The `-break-delete' Command
+---------------------------
+
+Synopsis
+........
+
+ -break-delete ( BREAKPOINT )+
+
+ Delete the breakpoint(s) whose number(s) are specified in the
+argument list. This is obviously reflected in the breakpoint list.
+
+GDB Command
+...........
+
+The corresponding GDB command is `delete'.
+
+Example
+.......
+
+ (gdb)
+ -break-delete 1
+ ^done
+ (gdb)
+ -break-list
+ ^done,BreakpointTable={nr_rows="0",nr_cols="6",
+ hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"},
+ {width="14",alignment="-1",col_name="type",colhdr="Type"},
+ {width="4",alignment="-1",col_name="disp",colhdr="Disp"},
+ {width="3",alignment="-1",col_name="enabled",colhdr="Enb"},
+ {width="10",alignment="-1",col_name="addr",colhdr="Address"},
+ {width="40",alignment="2",col_name="what",colhdr="What"}],
+ body=[]}
+ (gdb)
+
+The `-break-disable' Command
+----------------------------
+
+Synopsis
+........
+
+ -break-disable ( BREAKPOINT )+
+
+ Disable the named BREAKPOINT(s). The field `enabled' in the break
+list is now set to `n' for the named BREAKPOINT(s).
+
+GDB Command
+...........
+
+The corresponding GDB command is `disable'.
+
+Example
+.......
+
+ (gdb)
+ -break-disable 2
+ ^done
+ (gdb)
+ -break-list
+ ^done,BreakpointTable={nr_rows="1",nr_cols="6",
+ hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"},
+ {width="14",alignment="-1",col_name="type",colhdr="Type"},
+ {width="4",alignment="-1",col_name="disp",colhdr="Disp"},
+ {width="3",alignment="-1",col_name="enabled",colhdr="Enb"},
+ {width="10",alignment="-1",col_name="addr",colhdr="Address"},
+ {width="40",alignment="2",col_name="what",colhdr="What"}],
+ body=[bkpt={number="2",type="breakpoint",disp="keep",enabled="n",
+ addr="0x000100d0",func="main",file="hello.c",fullname="/home/foo/hello.c",
+ line="5",times="0"}]}
+ (gdb)
+
+The `-break-enable' Command
+---------------------------
+
+Synopsis
+........
+
+ -break-enable ( BREAKPOINT )+
+
+ Enable (previously disabled) BREAKPOINT(s).
+
+GDB Command
+...........
+
+The corresponding GDB command is `enable'.
+
+Example
+.......
+
+ (gdb)
+ -break-enable 2
+ ^done
+ (gdb)
+ -break-list
+ ^done,BreakpointTable={nr_rows="1",nr_cols="6",
+ hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"},
+ {width="14",alignment="-1",col_name="type",colhdr="Type"},
+ {width="4",alignment="-1",col_name="disp",colhdr="Disp"},
+ {width="3",alignment="-1",col_name="enabled",colhdr="Enb"},
+ {width="10",alignment="-1",col_name="addr",colhdr="Address"},
+ {width="40",alignment="2",col_name="what",colhdr="What"}],
+ body=[bkpt={number="2",type="breakpoint",disp="keep",enabled="y",
+ addr="0x000100d0",func="main",file="hello.c",fullname="/home/foo/hello.c",
+ line="5",times="0"}]}
+ (gdb)
+
+The `-break-info' Command
+-------------------------
+
+Synopsis
+........
+
+ -break-info BREAKPOINT
+
+ Get information about a single breakpoint.
+
+GDB Command
+...........
+
+The corresponding GDB command is `info break BREAKPOINT'.
+
+Example
+.......
+
+N.A.
+
+The `-break-insert' Command
+---------------------------
+
+Synopsis
+........
+
+ -break-insert [ -t ] [ -h ] [ -f ] [ -d ] [ -a ]
+ [ -c CONDITION ] [ -i IGNORE-COUNT ]
+ [ -p THREAD ] [ LOCATION ]
+
+If specified, LOCATION, can be one of:
+
+ * function
+
+ * filename:linenum
+
+ * filename:function
+
+ * *address
+
+ The possible optional parameters of this command are:
+
+`-t'
+ Insert a temporary breakpoint.
+
+`-h'
+ Insert a hardware breakpoint.
+
+`-c CONDITION'
+ Make the breakpoint conditional on CONDITION.
+
+`-i IGNORE-COUNT'
+ Initialize the IGNORE-COUNT.
+
+`-f'
+ If LOCATION cannot be parsed (for example if it refers to unknown
+ files or functions), create a pending breakpoint. Without this
+ flag, GDB will report an error, and won't create a breakpoint, if
+ LOCATION cannot be parsed.
+
+`-d'
+ Create a disabled breakpoint.
+
+`-a'
+ Create a tracepoint. *Note Tracepoints::. When this parameter is
+ used together with `-h', a fast tracepoint is created.
+
+Result
+......
+
+The result is in the form:
+
+ ^done,bkpt={number="NUMBER",type="TYPE",disp="del"|"keep",
+ enabled="y"|"n",addr="HEX",func="FUNCNAME",file="FILENAME",
+ fullname="FULL_FILENAME",line="LINENO",[thread="THREADNO,]
+ times="TIMES"}
+
+where NUMBER is the GDB number for this breakpoint, FUNCNAME is the
+name of the function where the breakpoint was inserted, FILENAME is the
+name of the source file which contains this function, LINENO is the
+source line number within that file and TIMES the number of times that
+the breakpoint has been hit (always 0 for -break-insert but may be
+greater for -break-info or -break-list which use the same output).
+
+ Note: this format is open to change.
+
+GDB Command
+...........
+
+The corresponding GDB commands are `break', `tbreak', `hbreak',
+`thbreak', and `rbreak'.
+
+Example
+.......
+
+ (gdb)
+ -break-insert main
+ ^done,bkpt={number="1",addr="0x0001072c",file="recursive2.c",
+ fullname="/home/foo/recursive2.c,line="4",times="0"}
+ (gdb)
+ -break-insert -t foo
+ ^done,bkpt={number="2",addr="0x00010774",file="recursive2.c",
+ fullname="/home/foo/recursive2.c,line="11",times="0"}
+ (gdb)
+ -break-list
+ ^done,BreakpointTable={nr_rows="2",nr_cols="6",
+ hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"},
+ {width="14",alignment="-1",col_name="type",colhdr="Type"},
+ {width="4",alignment="-1",col_name="disp",colhdr="Disp"},
+ {width="3",alignment="-1",col_name="enabled",colhdr="Enb"},
+ {width="10",alignment="-1",col_name="addr",colhdr="Address"},
+ {width="40",alignment="2",col_name="what",colhdr="What"}],
+ body=[bkpt={number="1",type="breakpoint",disp="keep",enabled="y",
+ addr="0x0001072c", func="main",file="recursive2.c",
+ fullname="/home/foo/recursive2.c,"line="4",times="0"},
+ bkpt={number="2",type="breakpoint",disp="del",enabled="y",
+ addr="0x00010774",func="foo",file="recursive2.c",
+ fullname="/home/foo/recursive2.c",line="11",times="0"}]}
+ (gdb)
+ -break-insert -r foo.*
+ ~int foo(int, int);
+ ^done,bkpt={number="3",addr="0x00010774",file="recursive2.c,
+ "fullname="/home/foo/recursive2.c",line="11",times="0"}
+ (gdb)
+
+The `-break-list' Command
+-------------------------
+
+Synopsis
+........
+
+ -break-list
+
+ Displays the list of inserted breakpoints, showing the following
+fields:
+
+`Number'
+ number of the breakpoint
+
+`Type'
+ type of the breakpoint: `breakpoint' or `watchpoint'
+
+`Disposition'
+ should the breakpoint be deleted or disabled when it is hit: `keep'
+ or `nokeep'
+
+`Enabled'
+ is the breakpoint enabled or no: `y' or `n'
+
+`Address'
+ memory location at which the breakpoint is set
+
+`What'
+ logical location of the breakpoint, expressed by function name,
+ file name, line number
+
+`Times'
+ number of times the breakpoint has been hit
+
+ If there are no breakpoints or watchpoints, the `BreakpointTable'
+`body' field is an empty list.
+
+GDB Command
+...........
+
+The corresponding GDB command is `info break'.
+
+Example
+.......
+
+ (gdb)
+ -break-list
+ ^done,BreakpointTable={nr_rows="2",nr_cols="6",
+ hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"},
+ {width="14",alignment="-1",col_name="type",colhdr="Type"},
+ {width="4",alignment="-1",col_name="disp",colhdr="Disp"},
+ {width="3",alignment="-1",col_name="enabled",colhdr="Enb"},
+ {width="10",alignment="-1",col_name="addr",colhdr="Address"},
+ {width="40",alignment="2",col_name="what",colhdr="What"}],
+ body=[bkpt={number="1",type="breakpoint",disp="keep",enabled="y",
+ addr="0x000100d0",func="main",file="hello.c",line="5",times="0"},
+ bkpt={number="2",type="breakpoint",disp="keep",enabled="y",
+ addr="0x00010114",func="foo",file="hello.c",fullname="/home/foo/hello.c",
+ line="13",times="0"}]}
+ (gdb)
+
+ Here's an example of the result when there are no breakpoints:
+
+ (gdb)
+ -break-list
+ ^done,BreakpointTable={nr_rows="0",nr_cols="6",
+ hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"},
+ {width="14",alignment="-1",col_name="type",colhdr="Type"},
+ {width="4",alignment="-1",col_name="disp",colhdr="Disp"},
+ {width="3",alignment="-1",col_name="enabled",colhdr="Enb"},
+ {width="10",alignment="-1",col_name="addr",colhdr="Address"},
+ {width="40",alignment="2",col_name="what",colhdr="What"}],
+ body=[]}
+ (gdb)
+
+The `-break-passcount' Command
+------------------------------
+
+Synopsis
+........
+
+ -break-passcount TRACEPOINT-NUMBER PASSCOUNT
+
+ Set the passcount for tracepoint TRACEPOINT-NUMBER to PASSCOUNT. If
+the breakpoint referred to by TRACEPOINT-NUMBER is not a tracepoint,
+error is emitted. This corresponds to CLI command `passcount'.
+
+The `-break-watch' Command
+--------------------------
+
+Synopsis
+........
+
+ -break-watch [ -a | -r ]
+
+ Create a watchpoint. With the `-a' option it will create an
+"access" watchpoint, i.e., a watchpoint that triggers either on a read
+from or on a write to the memory location. With the `-r' option, the
+watchpoint created is a "read" watchpoint, i.e., it will trigger only
+when the memory location is accessed for reading. Without either of
+the options, the watchpoint created is a regular watchpoint, i.e., it
+will trigger when the memory location is accessed for writing. *Note
+Setting Watchpoints: Set Watchpoints.
+
+ Note that `-break-list' will report a single list of watchpoints and
+breakpoints inserted.
+
+GDB Command
+...........
+
+The corresponding GDB commands are `watch', `awatch', and `rwatch'.
+
+Example
+.......
+
+Setting a watchpoint on a variable in the `main' function:
+
+ (gdb)
+ -break-watch x
+ ^done,wpt={number="2",exp="x"}
+ (gdb)
+ -exec-continue
+ ^running
+ (gdb)
+ *stopped,reason="watchpoint-trigger",wpt={number="2",exp="x"},
+ value={old="-268439212",new="55"},
+ frame={func="main",args=[],file="recursive2.c",
+ fullname="/home/foo/bar/recursive2.c",line="5"}
+ (gdb)
+
+ Setting a watchpoint on a variable local to a function. GDB will
+stop the program execution twice: first for the variable changing
+value, then for the watchpoint going out of scope.
+
+ (gdb)
+ -break-watch C
+ ^done,wpt={number="5",exp="C"}
+ (gdb)
+ -exec-continue
+ ^running
+ (gdb)
+ *stopped,reason="watchpoint-trigger",
+ wpt={number="5",exp="C"},value={old="-276895068",new="3"},
+ frame={func="callee4",args=[],
+ file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
+ fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="13"}
+ (gdb)
+ -exec-continue
+ ^running
+ (gdb)
+ *stopped,reason="watchpoint-scope",wpnum="5",
+ frame={func="callee3",args=[{name="strarg",
+ value="0x11940 \"A string argument.\""}],
+ file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
+ fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="18"}
+ (gdb)
+
+ Listing breakpoints and watchpoints, at different points in the
+program execution. Note that once the watchpoint goes out of scope, it
+is deleted.
+
+ (gdb)
+ -break-watch C
+ ^done,wpt={number="2",exp="C"}
+ (gdb)
+ -break-list
+ ^done,BreakpointTable={nr_rows="2",nr_cols="6",
+ hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"},
+ {width="14",alignment="-1",col_name="type",colhdr="Type"},
+ {width="4",alignment="-1",col_name="disp",colhdr="Disp"},
+ {width="3",alignment="-1",col_name="enabled",colhdr="Enb"},
+ {width="10",alignment="-1",col_name="addr",colhdr="Address"},
+ {width="40",alignment="2",col_name="what",colhdr="What"}],
+ body=[bkpt={number="1",type="breakpoint",disp="keep",enabled="y",
+ addr="0x00010734",func="callee4",
+ file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
+ fullname="/home/foo/devo/gdb/testsuite/gdb.mi/basics.c"line="8",times="1"},
+ bkpt={number="2",type="watchpoint",disp="keep",
+ enabled="y",addr="",what="C",times="0"}]}
+ (gdb)
+ -exec-continue
+ ^running
+ (gdb)
+ *stopped,reason="watchpoint-trigger",wpt={number="2",exp="C"},
+ value={old="-276895068",new="3"},
+ frame={func="callee4",args=[],
+ file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
+ fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="13"}
+ (gdb)
+ -break-list
+ ^done,BreakpointTable={nr_rows="2",nr_cols="6",
+ hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"},
+ {width="14",alignment="-1",col_name="type",colhdr="Type"},
+ {width="4",alignment="-1",col_name="disp",colhdr="Disp"},
+ {width="3",alignment="-1",col_name="enabled",colhdr="Enb"},
+ {width="10",alignment="-1",col_name="addr",colhdr="Address"},
+ {width="40",alignment="2",col_name="what",colhdr="What"}],
+ body=[bkpt={number="1",type="breakpoint",disp="keep",enabled="y",
+ addr="0x00010734",func="callee4",
+ file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
+ fullname="/home/foo/devo/gdb/testsuite/gdb.mi/basics.c",line="8",times="1"},
+ bkpt={number="2",type="watchpoint",disp="keep",
+ enabled="y",addr="",what="C",times="-5"}]}
+ (gdb)
+ -exec-continue
+ ^running
+ ^done,reason="watchpoint-scope",wpnum="2",
+ frame={func="callee3",args=[{name="strarg",
+ value="0x11940 \"A string argument.\""}],
+ file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
+ fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="18"}
+ (gdb)
+ -break-list
+ ^done,BreakpointTable={nr_rows="1",nr_cols="6",
+ hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"},
+ {width="14",alignment="-1",col_name="type",colhdr="Type"},
+ {width="4",alignment="-1",col_name="disp",colhdr="Disp"},
+ {width="3",alignment="-1",col_name="enabled",colhdr="Enb"},
+ {width="10",alignment="-1",col_name="addr",colhdr="Address"},
+ {width="40",alignment="2",col_name="what",colhdr="What"}],
+ body=[bkpt={number="1",type="breakpoint",disp="keep",enabled="y",
+ addr="0x00010734",func="callee4",
+ file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
+ fullname="/home/foo/devo/gdb/testsuite/gdb.mi/basics.c",line="8",
+ times="1"}]}
+ (gdb)
+
+
+File: gdb.info, Node: GDB/MI Program Context, Next: GDB/MI Thread Commands, Prev: GDB/MI Breakpoint Commands, Up: GDB/MI
+
+27.9 GDB/MI Program Context
+============================
+
+The `-exec-arguments' Command
+-----------------------------
+
+Synopsis
+........
+
+ -exec-arguments ARGS
+
+ Set the inferior program arguments, to be used in the next
+`-exec-run'.
+
+GDB Command
+...........
+
+The corresponding GDB command is `set args'.
+
+Example
+.......
+
+ (gdb)
+ -exec-arguments -v word
+ ^done
+ (gdb)
+
+The `-environment-cd' Command
+-----------------------------
+
+Synopsis
+........
+
+ -environment-cd PATHDIR
+
+ Set GDB's working directory.
+
+GDB Command
+...........
+
+The corresponding GDB command is `cd'.
+
+Example
+.......
+
+ (gdb)
+ -environment-cd /kwikemart/marge/ezannoni/flathead-dev/devo/gdb
+ ^done
+ (gdb)
+
+The `-environment-directory' Command
+------------------------------------
+
+Synopsis
+........
+
+ -environment-directory [ -r ] [ PATHDIR ]+
+
+ Add directories PATHDIR to beginning of search path for source files.
+If the `-r' option is used, the search path is reset to the default
+search path. If directories PATHDIR are supplied in addition to the
+`-r' option, the search path is first reset and then addition occurs as
+normal. Multiple directories may be specified, separated by blanks.
+Specifying multiple directories in a single command results in the
+directories added to the beginning of the search path in the same order
+they were presented in the command. If blanks are needed as part of a
+directory name, double-quotes should be used around the name. In the
+command output, the path will show up separated by the system
+directory-separator character. The directory-separator character must
+not be used in any directory name. If no directories are specified,
+the current search path is displayed.
+
+GDB Command
+...........
+
+The corresponding GDB command is `dir'.
+
+Example
+.......
+
+ (gdb)
+ -environment-directory /kwikemart/marge/ezannoni/flathead-dev/devo/gdb
+ ^done,source-path="/kwikemart/marge/ezannoni/flathead-dev/devo/gdb:$cdir:$cwd"
+ (gdb)
+ -environment-directory ""
+ ^done,source-path="/kwikemart/marge/ezannoni/flathead-dev/devo/gdb:$cdir:$cwd"
+ (gdb)
+ -environment-directory -r /home/jjohnstn/src/gdb /usr/src
+ ^done,source-path="/home/jjohnstn/src/gdb:/usr/src:$cdir:$cwd"
+ (gdb)
+ -environment-directory -r
+ ^done,source-path="$cdir:$cwd"
+ (gdb)
+
+The `-environment-path' Command
+-------------------------------
+
+Synopsis
+........
+
+ -environment-path [ -r ] [ PATHDIR ]+
+
+ Add directories PATHDIR to beginning of search path for object files.
+If the `-r' option is used, the search path is reset to the original
+search path that existed at gdb start-up. If directories PATHDIR are
+supplied in addition to the `-r' option, the search path is first reset
+and then addition occurs as normal. Multiple directories may be
+specified, separated by blanks. Specifying multiple directories in a
+single command results in the directories added to the beginning of the
+search path in the same order they were presented in the command. If
+blanks are needed as part of a directory name, double-quotes should be
+used around the name. In the command output, the path will show up
+separated by the system directory-separator character. The
+directory-separator character must not be used in any directory name.
+If no directories are specified, the current path is displayed.
+
+GDB Command
+...........
+
+The corresponding GDB command is `path'.
+
+Example
+.......
+
+ (gdb)
+ -environment-path
+ ^done,path="/usr/bin"
+ (gdb)
+ -environment-path /kwikemart/marge/ezannoni/flathead-dev/ppc-eabi/gdb /bin
+ ^done,path="/kwikemart/marge/ezannoni/flathead-dev/ppc-eabi/gdb:/bin:/usr/bin"
+ (gdb)
+ -environment-path -r /usr/local/bin
+ ^done,path="/usr/local/bin:/usr/bin"
+ (gdb)
+
+The `-environment-pwd' Command
+------------------------------
+
+Synopsis
+........
+
+ -environment-pwd
+
+ Show the current working directory.
+
+GDB Command
+...........
+
+The corresponding GDB command is `pwd'.
+
+Example
+.......
+
+ (gdb)
+ -environment-pwd
+ ^done,cwd="/kwikemart/marge/ezannoni/flathead-dev/devo/gdb"
+ (gdb)
+
+
+File: gdb.info, Node: GDB/MI Thread Commands, Next: GDB/MI Ada Tasking Commands, Prev: GDB/MI Program Context, Up: GDB/MI
+
+27.10 GDB/MI Thread Commands
+============================
+
+The `-thread-info' Command
+--------------------------
+
+Synopsis
+........
+
+ -thread-info [ THREAD-ID ]
+
+ Reports information about either a specific thread, if the THREAD-ID
+parameter is present, or about all threads. When printing information
+about all threads, also reports the current thread.
+
+GDB Command
+...........
+
+The `info thread' command prints the same information about all threads.
+
+Result
+......
+
+The result is a list of threads. The following attributes are defined
+for a given thread:
+
+`current'
+ This field exists only for the current thread. It has the value
+ `*'.
+
+`id'
+ The identifier that GDB uses to refer to the thread.
+
+`target-id'
+ The identifier that the target uses to refer to the thread.
+
+`details'
+ Extra information about the thread, in a target-specific format.
+ This field is optional.
+
+`name'
+ The name of the thread. If the user specified a name using the
+ `thread name' command, then this name is given. Otherwise, if GDB
+ can extract the thread name from the target, then that name is
+ given. If GDB cannot find the thread name, then this field is
+ omitted.
+
+`frame'
+ The stack frame currently executing in the thread.
+
+`state'
+ The thread's state. The `state' field may have the following
+ values:
+
+ `stopped'
+ The thread is stopped. Frame information is available for
+ stopped threads.
+
+ `running'
+ The thread is running. There's no frame information for
+ running threads.
+
+
+`core'
+ If GDB can find the CPU core on which this thread is running, then
+ this field is the core identifier. This field is optional.
+
+
+Example
+.......
+
+ -thread-info
+ ^done,threads=[
+ {id="2",target-id="Thread 0xb7e14b90 (LWP 21257)",
+ frame={level="0",addr="0xffffe410",func="__kernel_vsyscall",
+ args=[]},state="running"},
+ {id="1",target-id="Thread 0xb7e156b0 (LWP 21254)",
+ frame={level="0",addr="0x0804891f",func="foo",
+ args=[{name="i",value="10"}],
+ file="/tmp/a.c",fullname="/tmp/a.c",line="158"},
+ state="running"}],
+ current-thread-id="1"
+ (gdb)
+
+The `-thread-list-ids' Command
+------------------------------
+
+Synopsis
+........
+
+ -thread-list-ids
+
+ Produces a list of the currently known GDB thread ids. At the end
+of the list it also prints the total number of such threads.
+
+ This command is retained for historical reasons, the `-thread-info'
+command should be used instead.
+
+GDB Command
+...........
+
+Part of `info threads' supplies the same information.
+
+Example
+.......
+
+ (gdb)
+ -thread-list-ids
+ ^done,thread-ids={thread-id="3",thread-id="2",thread-id="1"},
+ current-thread-id="1",number-of-threads="3"
+ (gdb)
+
+The `-thread-select' Command
+----------------------------
+
+Synopsis
+........
+
+ -thread-select THREADNUM
+
+ Make THREADNUM the current thread. It prints the number of the new
+current thread, and the topmost frame for that thread.
+
+ This command is deprecated in favor of explicitly using the
+`--thread' option to each command.
+
+GDB Command
+...........
+
+The corresponding GDB command is `thread'.
+
+Example
+.......
+
+ (gdb)
+ -exec-next
+ ^running
+ (gdb)
+ *stopped,reason="end-stepping-range",thread-id="2",line="187",
+ file="../../../devo/gdb/testsuite/gdb.threads/linux-dp.c"
+ (gdb)
+ -thread-list-ids
+ ^done,
+ thread-ids={thread-id="3",thread-id="2",thread-id="1"},
+ number-of-threads="3"
+ (gdb)
+ -thread-select 3
+ ^done,new-thread-id="3",
+ frame={level="0",func="vprintf",
+ args=[{name="format",value="0x8048e9c \"%*s%c %d %c\\n\""},
+ {name="arg",value="0x2"}],file="vprintf.c",line="31"}
+ (gdb)
+
+
+File: gdb.info, Node: GDB/MI Ada Tasking Commands, Next: GDB/MI Program Execution, Prev: GDB/MI Thread Commands, Up: GDB/MI
+
+27.11 GDB/MI Ada Tasking Commands
+=================================
+
+The `-ada-task-info' Command
+----------------------------
+
+Synopsis
+........
+
+ -ada-task-info [ TASK-ID ]
+
+ Reports information about either a specific Ada task, if the TASK-ID
+parameter is present, or about all Ada tasks.
+
+GDB Command
+...........
+
+The `info tasks' command prints the same information about all Ada
+tasks (*note Ada Tasks::).
+
+Result
+......
+
+The result is a table of Ada tasks. The following columns are defined
+for each Ada task:
+
+`current'
+ This field exists only for the current thread. It has the value
+ `*'.
+
+`id'
+ The identifier that GDB uses to refer to the Ada task.
+
+`task-id'
+ The identifier that the target uses to refer to the Ada task.
+
+`thread-id'
+ The identifier of the thread corresponding to the Ada task.
+
+ This field should always exist, as Ada tasks are always implemented
+ on top of a thread. But if GDB cannot find this corresponding
+ thread for any reason, the field is omitted.
+
+`parent-id'
+ This field exists only when the task was created by another task.
+ In this case, it provides the ID of the parent task.
+
+`priority'
+ The base priority of the task.
+
+`state'
+ The current state of the task. For a detailed description of the
+ possible states, see *Note Ada Tasks::.
+
+`name'
+ The name of the task.
+
+
+Example
+.......
+
+ -ada-task-info
+ ^done,tasks={nr_rows="3",nr_cols="8",
+ hdr=[{width="1",alignment="-1",col_name="current",colhdr=""},
+ {width="3",alignment="1",col_name="id",colhdr="ID"},
+ {width="9",alignment="1",col_name="task-id",colhdr="TID"},
+ {width="4",alignment="1",col_name="thread-id",colhdr=""},
+ {width="4",alignment="1",col_name="parent-id",colhdr="P-ID"},
+ {width="3",alignment="1",col_name="priority",colhdr="Pri"},
+ {width="22",alignment="-1",col_name="state",colhdr="State"},
+ {width="1",alignment="2",col_name="name",colhdr="Name"}],
+ body=[{current="*",id="1",task-id=" 644010",thread-id="1",priority="48",
+ state="Child Termination Wait",name="main_task"}]}
+ (gdb)
+
+
+File: gdb.info, Node: GDB/MI Program Execution, Next: GDB/MI Stack Manipulation, Prev: GDB/MI Ada Tasking Commands, Up: GDB/MI
+
+27.12 GDB/MI Program Execution
+==============================
+
+These are the asynchronous commands which generate the out-of-band
+record `*stopped'. Currently GDB only really executes asynchronously
+with remote targets and this interaction is mimicked in other cases.
+
+The `-exec-continue' Command
+----------------------------
+
+Synopsis
+........
+
+ -exec-continue [--reverse] [--all|--thread-group N]
+
+ Resumes the execution of the inferior program, which will continue
+to execute until it reaches a debugger stop event. If the `--reverse'
+option is specified, execution resumes in reverse until it reaches a
+stop event. Stop events may include
+ * breakpoints or watchpoints
+
+ * signals or exceptions
+
+ * the end of the process (or its beginning under `--reverse')
+
+ * the end or beginning of a replay log if one is being used.
+ In all-stop mode (*note All-Stop Mode::), may resume only one
+thread, or all threads, depending on the value of the
+`scheduler-locking' variable. If `--all' is specified, all threads (in
+all inferiors) will be resumed. The `--all' option is ignored in
+all-stop mode. If the `--thread-group' options is specified, then all
+threads in that thread group are resumed.
+
+GDB Command
+...........
+
+The corresponding GDB corresponding is `continue'.
+
+Example
+.......
+
+ -exec-continue
+ ^running
+ (gdb)
+ @Hello world
+ *stopped,reason="breakpoint-hit",disp="keep",bkptno="2",frame={
+ func="foo",args=[],file="hello.c",fullname="/home/foo/bar/hello.c",
+ line="13"}
+ (gdb)
+
+The `-exec-finish' Command
+--------------------------
+
+Synopsis
+........
+
+ -exec-finish [--reverse]
+
+ Resumes the execution of the inferior program until the current
+function is exited. Displays the results returned by the function. If
+the `--reverse' option is specified, resumes the reverse execution of
+the inferior program until the point where current function was called.
+
+GDB Command
+...........
+
+The corresponding GDB command is `finish'.
+
+Example
+.......
+
+Function returning `void'.
+
+ -exec-finish
+ ^running
+ (gdb)
+ @hello from foo
+ *stopped,reason="function-finished",frame={func="main",args=[],
+ file="hello.c",fullname="/home/foo/bar/hello.c",line="7"}
+ (gdb)
+
+ Function returning other than `void'. The name of the internal GDB
+variable storing the result is printed, together with the value itself.
+
+ -exec-finish
+ ^running
+ (gdb)
+ *stopped,reason="function-finished",frame={addr="0x000107b0",func="foo",
+ args=[{name="a",value="1"],{name="b",value="9"}},
+ file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"},
+ gdb-result-var="$1",return-value="0"
+ (gdb)
+
+The `-exec-interrupt' Command
+-----------------------------
+
+Synopsis
+........
+
+ -exec-interrupt [--all|--thread-group N]
+
+ Interrupts the background execution of the target. Note how the
+token associated with the stop message is the one for the execution
+command that has been interrupted. The token for the interrupt itself
+only appears in the `^done' output. If the user is trying to interrupt
+a non-running program, an error message will be printed.
+
+ Note that when asynchronous execution is enabled, this command is
+asynchronous just like other execution commands. That is, first the
+`^done' response will be printed, and the target stop will be reported
+after that using the `*stopped' notification.
+
+ In non-stop mode, only the context thread is interrupted by default.
+All threads (in all inferiors) will be interrupted if the `--all'
+option is specified. If the `--thread-group' option is specified, all
+threads in that group will be interrupted.
+
+GDB Command
+...........
+
+The corresponding GDB command is `interrupt'.
+
+Example
+.......
+
+ (gdb)
+ 111-exec-continue
+ 111^running
+
+ (gdb)
+ 222-exec-interrupt
+ 222^done
+ (gdb)
+ 111*stopped,signal-name="SIGINT",signal-meaning="Interrupt",
+ frame={addr="0x00010140",func="foo",args=[],file="try.c",
+ fullname="/home/foo/bar/try.c",line="13"}
+ (gdb)
+
+ (gdb)
+ -exec-interrupt
+ ^error,msg="mi_cmd_exec_interrupt: Inferior not executing."
+ (gdb)
+
+The `-exec-jump' Command
+------------------------
+
+Synopsis
+........
+
+ -exec-jump LOCATION
+
+ Resumes execution of the inferior program at the location specified
+by parameter. *Note Specify Location::, for a description of the
+different forms of LOCATION.
+
+GDB Command
+...........
+
+The corresponding GDB command is `jump'.
+
+Example
+.......
+
+ -exec-jump foo.c:10
+ *running,thread-id="all"
+ ^running
+
+The `-exec-next' Command
+------------------------
+
+Synopsis
+........
+
+ -exec-next [--reverse]
+
+ Resumes execution of the inferior program, stopping when the
+beginning of the next source line is reached.
+
+ If the `--reverse' option is specified, resumes reverse execution of
+the inferior program, stopping at the beginning of the previous source
+line. If you issue this command on the first line of a function, it
+will take you back to the caller of that function, to the source line
+where the function was called.
+
+GDB Command
+...........
+
+The corresponding GDB command is `next'.
+
+Example
+.......
+
+ -exec-next
+ ^running
+ (gdb)
+ *stopped,reason="end-stepping-range",line="8",file="hello.c"
+ (gdb)
+
+The `-exec-next-instruction' Command
+------------------------------------
+
+Synopsis
+........
+
+ -exec-next-instruction [--reverse]
+
+ Executes one machine instruction. If the instruction is a function
+call, continues until the function returns. If the program stops at an
+instruction in the middle of a source line, the address will be printed
+as well.
+
+ If the `--reverse' option is specified, resumes reverse execution of
+the inferior program, stopping at the previous instruction. If the
+previously executed instruction was a return from another function, it
+will continue to execute in reverse until the call to that function
+(from the current stack frame) is reached.
+
+GDB Command
+...........
+
+The corresponding GDB command is `nexti'.
+
+Example
+.......
+
+ (gdb)
+ -exec-next-instruction
+ ^running
+
+ (gdb)
+ *stopped,reason="end-stepping-range",
+ addr="0x000100d4",line="5",file="hello.c"
+ (gdb)
+
+The `-exec-return' Command
+--------------------------
+
+Synopsis
+........
+
+ -exec-return
+
+ Makes current function return immediately. Doesn't execute the
+inferior. Displays the new current frame.
+
+GDB Command
+...........
+
+The corresponding GDB command is `return'.
+
+Example
+.......
+
+ (gdb)
+ 200-break-insert callee4
+ 200^done,bkpt={number="1",addr="0x00010734",
+ file="../../../devo/gdb/testsuite/gdb.mi/basics.c",line="8"}
+ (gdb)
+ 000-exec-run
+ 000^running
+ (gdb)
+ 000*stopped,reason="breakpoint-hit",disp="keep",bkptno="1",
+ frame={func="callee4",args=[],
+ file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
+ fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="8"}
+ (gdb)
+ 205-break-delete
+ 205^done
+ (gdb)
+ 111-exec-return
+ 111^done,frame={level="0",func="callee3",
+ args=[{name="strarg",
+ value="0x11940 \"A string argument.\""}],
+ file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
+ fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="18"}
+ (gdb)
+
+The `-exec-run' Command
+-----------------------
+
+Synopsis
+........
+
+ -exec-run [--all | --thread-group N]
+
+ Starts execution of the inferior from the beginning. The inferior
+executes until either a breakpoint is encountered or the program exits.
+In the latter case the output will include an exit code, if the
+program has exited exceptionally.
+
+ When no option is specified, the current inferior is started. If the
+`--thread-group' option is specified, it should refer to a thread group
+of type `process', and that thread group will be started. If the
+`--all' option is specified, then all inferiors will be started.
+
+GDB Command
+...........
+
+The corresponding GDB command is `run'.
+
+Examples
+........
+
+ (gdb)
+ -break-insert main
+ ^done,bkpt={number="1",addr="0x0001072c",file="recursive2.c",line="4"}
+ (gdb)
+ -exec-run
+ ^running
+ (gdb)
+ *stopped,reason="breakpoint-hit",disp="keep",bkptno="1",
+ frame={func="main",args=[],file="recursive2.c",
+ fullname="/home/foo/bar/recursive2.c",line="4"}
+ (gdb)
+
+Program exited normally:
+
+ (gdb)
+ -exec-run
+ ^running
+ (gdb)
+ x = 55
+ *stopped,reason="exited-normally"
+ (gdb)
+
+Program exited exceptionally:
+
+ (gdb)
+ -exec-run
+ ^running
+ (gdb)
+ x = 55
+ *stopped,reason="exited",exit-code="01"
+ (gdb)
+
+ Another way the program can terminate is if it receives a signal
+such as `SIGINT'. In this case, GDB/MI displays this:
+
+ (gdb)
+ *stopped,reason="exited-signalled",signal-name="SIGINT",
+ signal-meaning="Interrupt"
+
+The `-exec-step' Command
+------------------------
+
+Synopsis
+........
+
+ -exec-step [--reverse]
+
+ Resumes execution of the inferior program, stopping when the
+beginning of the next source line is reached, if the next source line
+is not a function call. If it is, stop at the first instruction of the
+called function. If the `--reverse' option is specified, resumes
+reverse execution of the inferior program, stopping at the beginning of
+the previously executed source line.
+
+GDB Command
+...........
+
+The corresponding GDB command is `step'.
+
+Example
+.......
+
+Stepping into a function:
+
+ -exec-step
+ ^running
+ (gdb)
+ *stopped,reason="end-stepping-range",
+ frame={func="foo",args=[{name="a",value="10"},
+ {name="b",value="0"}],file="recursive2.c",
+ fullname="/home/foo/bar/recursive2.c",line="11"}
+ (gdb)
+
+ Regular stepping:
+
+ -exec-step
+ ^running
+ (gdb)
+ *stopped,reason="end-stepping-range",line="14",file="recursive2.c"
+ (gdb)
+
+The `-exec-step-instruction' Command
+------------------------------------
+
+Synopsis
+........
+
+ -exec-step-instruction [--reverse]
+
+ Resumes the inferior which executes one machine instruction. If the
+`--reverse' option is specified, resumes reverse execution of the
+inferior program, stopping at the previously executed instruction. The
+output, once GDB has stopped, will vary depending on whether we have
+stopped in the middle of a source line or not. In the former case, the
+address at which the program stopped will be printed as well.
+
+GDB Command
+...........
+
+The corresponding GDB command is `stepi'.
+
+Example
+.......
+
+ (gdb)
+ -exec-step-instruction
+ ^running
+
+ (gdb)
+ *stopped,reason="end-stepping-range",
+ frame={func="foo",args=[],file="try.c",
+ fullname="/home/foo/bar/try.c",line="10"}
+ (gdb)
+ -exec-step-instruction
+ ^running
+
+ (gdb)
+ *stopped,reason="end-stepping-range",
+ frame={addr="0x000100f4",func="foo",args=[],file="try.c",
+ fullname="/home/foo/bar/try.c",line="10"}
+ (gdb)
+
+The `-exec-until' Command
+-------------------------
+
+Synopsis
+........
+
+ -exec-until [ LOCATION ]
+
+ Executes the inferior until the LOCATION specified in the argument
+is reached. If there is no argument, the inferior executes until a
+source line greater than the current one is reached. The reason for
+stopping in this case will be `location-reached'.
+
+GDB Command
+...........
+
+The corresponding GDB command is `until'.
+
+Example
+.......
+
+ (gdb)
+ -exec-until recursive2.c:6
+ ^running
+ (gdb)
+ x = 55
+ *stopped,reason="location-reached",frame={func="main",args=[],
+ file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="6"}
+ (gdb)
+
+
+File: gdb.info, Node: GDB/MI Stack Manipulation, Next: GDB/MI Variable Objects, Prev: GDB/MI Program Execution, Up: GDB/MI
+
+27.13 GDB/MI Stack Manipulation Commands
+========================================
+
+The `-stack-info-frame' Command
+-------------------------------
+
+Synopsis
+........
+
+ -stack-info-frame
+
+ Get info on the selected frame.
+
+GDB Command
+...........
+
+The corresponding GDB command is `info frame' or `frame' (without
+arguments).
+
+Example
+.......
+
+ (gdb)
+ -stack-info-frame
+ ^done,frame={level="1",addr="0x0001076c",func="callee3",
+ file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
+ fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="17"}
+ (gdb)
+
+The `-stack-info-depth' Command
+-------------------------------
+
+Synopsis
+........
+
+ -stack-info-depth [ MAX-DEPTH ]
+
+ Return the depth of the stack. If the integer argument MAX-DEPTH is
+specified, do not count beyond MAX-DEPTH frames.
+
+GDB Command
+...........
+
+There's no equivalent GDB command.
+
+Example
+.......
+
+For a stack with frame levels 0 through 11:
+
+ (gdb)
+ -stack-info-depth
+ ^done,depth="12"
+ (gdb)
+ -stack-info-depth 4
+ ^done,depth="4"
+ (gdb)
+ -stack-info-depth 12
+ ^done,depth="12"
+ (gdb)
+ -stack-info-depth 11
+ ^done,depth="11"
+ (gdb)
+ -stack-info-depth 13
+ ^done,depth="12"
+ (gdb)
+
+The `-stack-list-arguments' Command
+-----------------------------------
+
+Synopsis
+........
+
+ -stack-list-arguments PRINT-VALUES
+ [ LOW-FRAME HIGH-FRAME ]
+
+ Display a list of the arguments for the frames between LOW-FRAME and
+HIGH-FRAME (inclusive). If LOW-FRAME and HIGH-FRAME are not provided,
+list the arguments for the whole call stack. If the two arguments are
+equal, show the single frame at the corresponding level. It is an
+error if LOW-FRAME is larger than the actual number of frames. On the
+other hand, HIGH-FRAME may be larger than the actual number of frames,
+in which case only existing frames will be returned.
+
+ If PRINT-VALUES is 0 or `--no-values', print only the names of the
+variables; if it is 1 or `--all-values', print also their values; and
+if it is 2 or `--simple-values', print the name, type and value for
+simple data types, and the name and type for arrays, structures and
+unions.
+
+ Use of this command to obtain arguments in a single frame is
+deprecated in favor of the `-stack-list-variables' command.
+
+GDB Command
+...........
+
+GDB does not have an equivalent command. `gdbtk' has a `gdb_get_args'
+command which partially overlaps with the functionality of
+`-stack-list-arguments'.
+
+Example
+.......
+
+ (gdb)
+ -stack-list-frames
+ ^done,
+ stack=[
+ frame={level="0",addr="0x00010734",func="callee4",
+ file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
+ fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="8"},
+ frame={level="1",addr="0x0001076c",func="callee3",
+ file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
+ fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="17"},
+ frame={level="2",addr="0x0001078c",func="callee2",
+ file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
+ fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="22"},
+ frame={level="3",addr="0x000107b4",func="callee1",
+ file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
+ fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="27"},
+ frame={level="4",addr="0x000107e0",func="main",
+ file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
+ fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="32"}]
+ (gdb)
+ -stack-list-arguments 0
+ ^done,
+ stack-args=[
+ frame={level="0",args=[]},
+ frame={level="1",args=[name="strarg"]},
+ frame={level="2",args=[name="intarg",name="strarg"]},
+ frame={level="3",args=[name="intarg",name="strarg",name="fltarg"]},
+ frame={level="4",args=[]}]
+ (gdb)
+ -stack-list-arguments 1
+ ^done,
+ stack-args=[
+ frame={level="0",args=[]},
+ frame={level="1",
+ args=[{name="strarg",value="0x11940 \"A string argument.\""}]},
+ frame={level="2",args=[
+ {name="intarg",value="2"},
+ {name="strarg",value="0x11940 \"A string argument.\""}]},
+ {frame={level="3",args=[
+ {name="intarg",value="2"},
+ {name="strarg",value="0x11940 \"A string argument.\""},
+ {name="fltarg",value="3.5"}]},
+ frame={level="4",args=[]}]
+ (gdb)
+ -stack-list-arguments 0 2 2
+ ^done,stack-args=[frame={level="2",args=[name="intarg",name="strarg"]}]
+ (gdb)
+ -stack-list-arguments 1 2 2
+ ^done,stack-args=[frame={level="2",
+ args=[{name="intarg",value="2"},
+ {name="strarg",value="0x11940 \"A string argument.\""}]}]
+ (gdb)
+
+The `-stack-list-frames' Command
+--------------------------------
+
+Synopsis
+........
+
+ -stack-list-frames [ LOW-FRAME HIGH-FRAME ]
+
+ List the frames currently on the stack. For each frame it displays
+the following info:
+
+`LEVEL'
+ The frame number, 0 being the topmost frame, i.e., the innermost
+ function.
+
+`ADDR'
+ The `$pc' value for that frame.
+
+`FUNC'
+ Function name.
+
+`FILE'
+ File name of the source file where the function lives.
+
+`FULLNAME'
+ The full file name of the source file where the function lives.
+
+`LINE'
+ Line number corresponding to the `$pc'.
+
+`FROM'
+ The shared library where this function is defined. This is only
+ given if the frame's function is not known.
+
+ If invoked without arguments, this command prints a backtrace for the
+whole stack. If given two integer arguments, it shows the frames whose
+levels are between the two arguments (inclusive). If the two arguments
+are equal, it shows the single frame at the corresponding level. It is
+an error if LOW-FRAME is larger than the actual number of frames. On
+the other hand, HIGH-FRAME may be larger than the actual number of
+frames, in which case only existing frames will be returned.
+
+GDB Command
+...........
+
+The corresponding GDB commands are `backtrace' and `where'.
+
+Example
+.......
+
+Full stack backtrace:
+
+ (gdb)
+ -stack-list-frames
+ ^done,stack=
+ [frame={level="0",addr="0x0001076c",func="foo",
+ file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="11"},
+ frame={level="1",addr="0x000107a4",func="foo",
+ file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"},
+ frame={level="2",addr="0x000107a4",func="foo",
+ file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"},
+ frame={level="3",addr="0x000107a4",func="foo",
+ file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"},
+ frame={level="4",addr="0x000107a4",func="foo",
+ file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"},
+ frame={level="5",addr="0x000107a4",func="foo",
+ file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"},
+ frame={level="6",addr="0x000107a4",func="foo",
+ file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"},
+ frame={level="7",addr="0x000107a4",func="foo",
+ file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"},
+ frame={level="8",addr="0x000107a4",func="foo",
+ file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"},
+ frame={level="9",addr="0x000107a4",func="foo",
+ file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"},
+ frame={level="10",addr="0x000107a4",func="foo",
+ file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"},
+ frame={level="11",addr="0x00010738",func="main",
+ file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="4"}]
+ (gdb)
+
+ Show frames between LOW_FRAME and HIGH_FRAME:
+
+ (gdb)
+ -stack-list-frames 3 5
+ ^done,stack=
+ [frame={level="3",addr="0x000107a4",func="foo",
+ file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"},
+ frame={level="4",addr="0x000107a4",func="foo",
+ file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"},
+ frame={level="5",addr="0x000107a4",func="foo",
+ file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"}]
+ (gdb)
+
+ Show a single frame:
+
+ (gdb)
+ -stack-list-frames 3 3
+ ^done,stack=
+ [frame={level="3",addr="0x000107a4",func="foo",
+ file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"}]
+ (gdb)
+
+The `-stack-list-locals' Command
+--------------------------------
+
+Synopsis
+........
+
+ -stack-list-locals PRINT-VALUES
+
+ Display the local variable names for the selected frame. If
+PRINT-VALUES is 0 or `--no-values', print only the names of the
+variables; if it is 1 or `--all-values', print also their values; and
+if it is 2 or `--simple-values', print the name, type and value for
+simple data types, and the name and type for arrays, structures and
+unions. In this last case, a frontend can immediately display the
+value of simple data types and create variable objects for other data
+types when the user wishes to explore their values in more detail.
+
+ This command is deprecated in favor of the `-stack-list-variables'
+command.
+
+GDB Command
+...........
+
+`info locals' in GDB, `gdb_get_locals' in `gdbtk'.
+
+Example
+.......
+
+ (gdb)
+ -stack-list-locals 0
+ ^done,locals=[name="A",name="B",name="C"]
+ (gdb)
+ -stack-list-locals --all-values
+ ^done,locals=[{name="A",value="1"},{name="B",value="2"},
+ {name="C",value="{1, 2, 3}"}]
+ -stack-list-locals --simple-values
+ ^done,locals=[{name="A",type="int",value="1"},
+ {name="B",type="int",value="2"},{name="C",type="int [3]"}]
+ (gdb)
+
+The `-stack-list-variables' Command
+-----------------------------------
+
+Synopsis
+........
+
+ -stack-list-variables PRINT-VALUES
+
+ Display the names of local variables and function arguments for the
+selected frame. If PRINT-VALUES is 0 or `--no-values', print only the
+names of the variables; if it is 1 or `--all-values', print also their
+values; and if it is 2 or `--simple-values', print the name, type and
+value for simple data types, and the name and type for arrays,
+structures and unions.
+
+Example
+.......
+
+ (gdb)
+ -stack-list-variables --thread 1 --frame 0 --all-values
+ ^done,variables=[{name="x",value="11"},{name="s",value="{a = 1, b = 2}"}]
+ (gdb)
+
+The `-stack-select-frame' Command
+---------------------------------
+
+Synopsis
+........
+
+ -stack-select-frame FRAMENUM
+
+ Change the selected frame. Select a different frame FRAMENUM on the
+stack.
+
+ This command in deprecated in favor of passing the `--frame' option
+to every command.
+
+GDB Command
+...........
+
+The corresponding GDB commands are `frame', `up', `down',
+`select-frame', `up-silent', and `down-silent'.
+
+Example
+.......
+
+ (gdb)
+ -stack-select-frame 2
+ ^done
+ (gdb)
+
+
+File: gdb.info, Node: GDB/MI Variable Objects, Next: GDB/MI Data Manipulation, Prev: GDB/MI Stack Manipulation, Up: GDB/MI
+
+27.14 GDB/MI Variable Objects
+=============================
+
+Introduction to Variable Objects
+--------------------------------
+
+Variable objects are "object-oriented" MI interface for examining and
+changing values of expressions. Unlike some other MI interfaces that
+work with expressions, variable objects are specifically designed for
+simple and efficient presentation in the frontend. A variable object
+is identified by string name. When a variable object is created, the
+frontend specifies the expression for that variable object. The
+expression can be a simple variable, or it can be an arbitrary complex
+expression, and can even involve CPU registers. After creating a
+variable object, the frontend can invoke other variable object
+operations--for example to obtain or change the value of a variable
+object, or to change display format.
+
+ Variable objects have hierarchical tree structure. Any variable
+object that corresponds to a composite type, such as structure in C, has
+a number of child variable objects, for example corresponding to each
+element of a structure. A child variable object can itself have
+children, recursively. Recursion ends when we reach leaf variable
+objects, which always have built-in types. Child variable objects are
+created only by explicit request, so if a frontend is not interested in
+the children of a particular variable object, no child will be created.
+
+ For a leaf variable object it is possible to obtain its value as a
+string, or set the value from a string. String value can be also
+obtained for a non-leaf variable object, but it's generally a string
+that only indicates the type of the object, and does not list its
+contents. Assignment to a non-leaf variable object is not allowed.
+
+ A frontend does not need to read the values of all variable objects
+each time the program stops. Instead, MI provides an update command
+that lists all variable objects whose values has changed since the last
+update operation. This considerably reduces the amount of data that
+must be transferred to the frontend. As noted above, children variable
+objects are created on demand, and only leaf variable objects have a
+real value. As result, gdb will read target memory only for leaf
+variables that frontend has created.
+
+ The automatic update is not always desirable. For example, a
+frontend might want to keep a value of some expression for future
+reference, and never update it. For another example, fetching memory
+is relatively slow for embedded targets, so a frontend might want to
+disable automatic update for the variables that are either not visible
+on the screen, or "closed". This is possible using so called "frozen
+variable objects". Such variable objects are never implicitly updated.
+
+ Variable objects can be either "fixed" or "floating". For the fixed
+variable object, the expression is parsed when the variable object is
+created, including associating identifiers to specific variables. The
+meaning of expression never changes. For a floating variable object
+the values of variables whose names appear in the expressions are
+re-evaluated every time in the context of the current frame. Consider
+this example:
+
+ void do_work(...)
+ {
+ struct work_state state;
+
+ if (...)
+ do_work(...);
+ }
+
+ If a fixed variable object for the `state' variable is created in
+this function, and we enter the recursive call, the variable object
+will report the value of `state' in the top-level `do_work' invocation.
+On the other hand, a floating variable object will report the value of
+`state' in the current frame.
+
+ If an expression specified when creating a fixed variable object
+refers to a local variable, the variable object becomes bound to the
+thread and frame in which the variable object is created. When such
+variable object is updated, GDB makes sure that the thread/frame
+combination the variable object is bound to still exists, and
+re-evaluates the variable object in context of that thread/frame.
+
+ The following is the complete set of GDB/MI operations defined to
+access this functionality:
+
+*Operation* *Description*
+`-enable-pretty-printing' enable Python-based pretty-printing
+`-var-create' create a variable object
+`-var-delete' delete the variable object and/or its
+ children
+`-var-set-format' set the display format of this variable
+`-var-show-format' show the display format of this variable
+`-var-info-num-children' tells how many children this object has
+`-var-list-children' return a list of the object's children
+`-var-info-type' show the type of this variable object
+`-var-info-expression' print parent-relative expression that this
+ variable object represents
+`-var-info-path-expression' print full expression that this variable
+ object represents
+`-var-show-attributes' is this variable editable? does it exist
+ here?
+`-var-evaluate-expression' get the value of this variable
+`-var-assign' set the value of this variable
+`-var-update' update the variable and its children
+`-var-set-frozen' set frozeness attribute
+`-var-set-update-range' set range of children to display on update
+
+ In the next subsection we describe each operation in detail and
+suggest how it can be used.
+
+Description And Use of Operations on Variable Objects
+-----------------------------------------------------
+
+The `-enable-pretty-printing' Command
+-------------------------------------
+
+ -enable-pretty-printing
+
+ GDB allows Python-based visualizers to affect the output of the MI
+variable object commands. However, because there was no way to
+implement this in a fully backward-compatible way, a front end must
+request that this functionality be enabled.
+
+ Once enabled, this feature cannot be disabled.
+
+ Note that if Python support has not been compiled into GDB, this
+command will still succeed (and do nothing).
+
+ This feature is currently (as of GDB 7.0) experimental, and may work
+differently in future versions of GDB.
+
+The `-var-create' Command
+-------------------------
+
+Synopsis
+........
+
+ -var-create {NAME | "-"}
+ {FRAME-ADDR | "*" | "@"} EXPRESSION
+
+ This operation creates a variable object, which allows the
+monitoring of a variable, the result of an expression, a memory cell or
+a CPU register.
+
+ The NAME parameter is the string by which the object can be
+referenced. It must be unique. If `-' is specified, the varobj system
+will generate a string "varNNNNNN" automatically. It will be unique
+provided that one does not specify NAME of that format. The command
+fails if a duplicate name is found.
+
+ The frame under which the expression should be evaluated can be
+specified by FRAME-ADDR. A `*' indicates that the current frame should
+be used. A `@' indicates that a floating variable object must be
+created.
+
+ EXPRESSION is any expression valid on the current language set (must
+not begin with a `*'), or one of the following:
+
+ * `*ADDR', where ADDR is the address of a memory cell
+
+ * `*ADDR-ADDR' -- a memory address range (TBD)
+
+ * `$REGNAME' -- a CPU register name
+
+ A varobj's contents may be provided by a Python-based
+pretty-printer. In this case the varobj is known as a "dynamic
+varobj". Dynamic varobjs have slightly different semantics in some
+cases. If the `-enable-pretty-printing' command is not sent, then GDB
+will never create a dynamic varobj. This ensures backward
+compatibility for existing clients.
+
+Result
+......
+
+This operation returns attributes of the newly-created varobj. These
+are:
+
+`name'
+ The name of the varobj.
+
+`numchild'
+ The number of children of the varobj. This number is not
+ necessarily reliable for a dynamic varobj. Instead, you must
+ examine the `has_more' attribute.
+
+`value'
+ The varobj's scalar value. For a varobj whose type is some sort of
+ aggregate (e.g., a `struct'), or for a dynamic varobj, this value
+ will not be interesting.
+
+`type'
+ The varobj's type. This is a string representation of the type, as
+ would be printed by the GDB CLI.
+
+`thread-id'
+ If a variable object is bound to a specific thread, then this is
+ the thread's identifier.
+
+`has_more'
+ For a dynamic varobj, this indicates whether there appear to be any
+ children available. For a non-dynamic varobj, this will be 0.
+
+`dynamic'
+ This attribute will be present and have the value `1' if the
+ varobj is a dynamic varobj. If the varobj is not a dynamic varobj,
+ then this attribute will not be present.
+
+`displayhint'
+ A dynamic varobj can supply a display hint to the front end. The
+ value comes directly from the Python pretty-printer object's
+ `display_hint' method. *Note Pretty Printing API::.
+
+ Typical output will look like this:
+
+ name="NAME",numchild="N",type="TYPE",thread-id="M",
+ has_more="HAS_MORE"
+
+The `-var-delete' Command
+-------------------------
+
+Synopsis
+........
+
+ -var-delete [ -c ] NAME
+
+ Deletes a previously created variable object and all of its children.
+With the `-c' option, just deletes the children.
+
+ Returns an error if the object NAME is not found.
+
+The `-var-set-format' Command
+-----------------------------
+
+Synopsis
+........
+
+ -var-set-format NAME FORMAT-SPEC
+
+ Sets the output format for the value of the object NAME to be
+FORMAT-SPEC.
+
+ The syntax for the FORMAT-SPEC is as follows:
+
+ FORMAT-SPEC ==>
+ {binary | decimal | hexadecimal | octal | natural}
+
+ The natural format is the default format choosen automatically based
+on the variable type (like decimal for an `int', hex for pointers,
+etc.).
+
+ For a variable with children, the format is set only on the variable
+itself, and the children are not affected.
+
+The `-var-show-format' Command
+------------------------------
+
+Synopsis
+........
+
+ -var-show-format NAME
+
+ Returns the format used to display the value of the object NAME.
+
+ FORMAT ==>
+ FORMAT-SPEC
+
+The `-var-info-num-children' Command
+------------------------------------
+
+Synopsis
+........
+
+ -var-info-num-children NAME
+
+ Returns the number of children of a variable object NAME:
+
+ numchild=N
+
+ Note that this number is not completely reliable for a dynamic
+varobj. It will return the current number of children, but more
+children may be available.
+
+The `-var-list-children' Command
+--------------------------------
+
+Synopsis
+........
+
+ -var-list-children [PRINT-VALUES] NAME [FROM TO]
+
+ Return a list of the children of the specified variable object and
+create variable objects for them, if they do not already exist. With a
+single argument or if PRINT-VALUES has a value of 0 or `--no-values',
+print only the names of the variables; if PRINT-VALUES is 1 or
+`--all-values', also print their values; and if it is 2 or
+`--simple-values' print the name and value for simple data types and
+just the name for arrays, structures and unions.
+
+ FROM and TO, if specified, indicate the range of children to report.
+If FROM or TO is less than zero, the range is reset and all children
+will be reported. Otherwise, children starting at FROM (zero-based)
+and up to and excluding TO will be reported.
+
+ If a child range is requested, it will only affect the current call
+to `-var-list-children', but not future calls to `-var-update'. For
+this, you must instead use `-var-set-update-range'. The intent of this
+approach is to enable a front end to implement any update approach it
+likes; for example, scrolling a view may cause the front end to request
+more children with `-var-list-children', and then the front end could
+call `-var-set-update-range' with a different range to ensure that
+future updates are restricted to just the visible items.
+
+ For each child the following results are returned:
+
+NAME
+ Name of the variable object created for this child.
+
+EXP
+ The expression to be shown to the user by the front end to
+ designate this child. For example this may be the name of a
+ structure member.
+
+ For a dynamic varobj, this value cannot be used to form an
+ expression. There is no way to do this at all with a dynamic
+ varobj.
+
+ For C/C++ structures there are several pseudo children returned to
+ designate access qualifiers. For these pseudo children EXP is
+ `public', `private', or `protected'. In this case the type and
+ value are not present.
+
+ A dynamic varobj will not report the access qualifying
+ pseudo-children, regardless of the language. This information is
+ not available at all with a dynamic varobj.
+
+NUMCHILD
+ Number of children this child has. For a dynamic varobj, this
+ will be 0.
+
+TYPE
+ The type of the child.
+
+VALUE
+ If values were requested, this is the value.
+
+THREAD-ID
+ If this variable object is associated with a thread, this is the
+ thread id. Otherwise this result is not present.
+
+FROZEN
+ If the variable object is frozen, this variable will be present
+ with a value of 1.
+
+ The result may have its own attributes:
+
+`displayhint'
+ A dynamic varobj can supply a display hint to the front end. The
+ value comes directly from the Python pretty-printer object's
+ `display_hint' method. *Note Pretty Printing API::.
+
+`has_more'
+ This is an integer attribute which is nonzero if there are children
+ remaining after the end of the selected range.
+
+Example
+.......
+
+ (gdb)
+ -var-list-children n
+ ^done,numchild=N,children=[child={name=NAME,exp=EXP,
+ numchild=N,type=TYPE},(repeats N times)]
+ (gdb)
+ -var-list-children --all-values n
+ ^done,numchild=N,children=[child={name=NAME,exp=EXP,
+ numchild=N,value=VALUE,type=TYPE},(repeats N times)]
+
+The `-var-info-type' Command
+----------------------------
+
+Synopsis
+........
+
+ -var-info-type NAME
+
+ Returns the type of the specified variable NAME. The type is
+returned as a string in the same format as it is output by the GDB CLI:
+
+ type=TYPENAME
+
+The `-var-info-expression' Command
+----------------------------------
+
+Synopsis
+........
+
+ -var-info-expression NAME
+
+ Returns a string that is suitable for presenting this variable
+object in user interface. The string is generally not valid expression
+in the current language, and cannot be evaluated.
+
+ For example, if `a' is an array, and variable object `A' was created
+for `a', then we'll get this output:
+
+ (gdb) -var-info-expression A.1
+ ^done,lang="C",exp="1"
+
+Here, the values of `lang' can be `{"C" | "C++" | "Java"}'.
+
+ Note that the output of the `-var-list-children' command also
+includes those expressions, so the `-var-info-expression' command is of
+limited use.
+
+The `-var-info-path-expression' Command
+---------------------------------------
+
+Synopsis
+........
+
+ -var-info-path-expression NAME
+
+ Returns an expression that can be evaluated in the current context
+and will yield the same value that a variable object has. Compare this
+with the `-var-info-expression' command, which result can be used only
+for UI presentation. Typical use of the `-var-info-path-expression'
+command is creating a watchpoint from a variable object.
+
+ This command is currently not valid for children of a dynamic varobj,
+and will give an error when invoked on one.
+
+ For example, suppose `C' is a C++ class, derived from class `Base',
+and that the `Base' class has a member called `m_size'. Assume a
+variable `c' is has the type of `C' and a variable object `C' was
+created for variable `c'. Then, we'll get this output:
+ (gdb) -var-info-path-expression C.Base.public.m_size
+ ^done,path_expr=((Base)c).m_size)
+
+The `-var-show-attributes' Command
+----------------------------------
+
+Synopsis
+........
+
+ -var-show-attributes NAME
+
+ List attributes of the specified variable object NAME:
+
+ status=ATTR [ ( ,ATTR )* ]
+
+where ATTR is `{ { editable | noneditable } | TBD }'.
+
+The `-var-evaluate-expression' Command
+--------------------------------------
+
+Synopsis
+........
+
+ -var-evaluate-expression [-f FORMAT-SPEC] NAME
+
+ Evaluates the expression that is represented by the specified
+variable object and returns its value as a string. The format of the
+string can be specified with the `-f' option. The possible values of
+this option are the same as for `-var-set-format' (*note
+-var-set-format::). If the `-f' option is not specified, the current
+display format will be used. The current display format can be changed
+using the `-var-set-format' command.
+
+ value=VALUE
+
+ Note that one must invoke `-var-list-children' for a variable before
+the value of a child variable can be evaluated.
+
+The `-var-assign' Command
+-------------------------
+
+Synopsis
+........
+
+ -var-assign NAME EXPRESSION
+
+ Assigns the value of EXPRESSION to the variable object specified by
+NAME. The object must be `editable'. If the variable's value is
+altered by the assign, the variable will show up in any subsequent
+`-var-update' list.
+
+Example
+.......
+
+ (gdb)
+ -var-assign var1 3
+ ^done,value="3"
+ (gdb)
+ -var-update *
+ ^done,changelist=[{name="var1",in_scope="true",type_changed="false"}]
+ (gdb)
+
+The `-var-update' Command
+-------------------------
+
+Synopsis
+........
+
+ -var-update [PRINT-VALUES] {NAME | "*"}
+
+ Reevaluate the expressions corresponding to the variable object NAME
+and all its direct and indirect children, and return the list of
+variable objects whose values have changed; NAME must be a root
+variable object. Here, "changed" means that the result of
+`-var-evaluate-expression' before and after the `-var-update' is
+different. If `*' is used as the variable object names, all existing
+variable objects are updated, except for frozen ones (*note
+-var-set-frozen::). The option PRINT-VALUES determines whether both
+names and values, or just names are printed. The possible values of
+this option are the same as for `-var-list-children' (*note
+-var-list-children::). It is recommended to use the `--all-values'
+option, to reduce the number of MI commands needed on each program stop.
+
+ With the `*' parameter, if a variable object is bound to a currently
+running thread, it will not be updated, without any diagnostic.
+
+ If `-var-set-update-range' was previously used on a varobj, then
+only the selected range of children will be reported.
+
+ `-var-update' reports all the changed varobjs in a tuple named
+`changelist'.
+
+ Each item in the change list is itself a tuple holding:
+
+`name'
+ The name of the varobj.
+
+`value'
+ If values were requested for this update, then this field will be
+ present and will hold the value of the varobj.
+
+`in_scope'
+ This field is a string which may take one of three values:
+
+ `"true"'
+ The variable object's current value is valid.
+
+ `"false"'
+ The variable object does not currently hold a valid value but
+ it may hold one in the future if its associated expression
+ comes back into scope.
+
+ `"invalid"'
+ The variable object no longer holds a valid value. This can
+ occur when the executable file being debugged has changed,
+ either through recompilation or by using the GDB `file'
+ command. The front end should normally choose to delete
+ these variable objects.
+
+ In the future new values may be added to this list so the front
+ should be prepared for this possibility. *Note GDB/MI Development
+ and Front Ends: GDB/MI Development and Front Ends.
+
+`type_changed'
+ This is only present if the varobj is still valid. If the type
+ changed, then this will be the string `true'; otherwise it will be
+ `false'.
+
+`new_type'
+ If the varobj's type changed, then this field will be present and
+ will hold the new type.
+
+`new_num_children'
+ For a dynamic varobj, if the number of children changed, or if the
+ type changed, this will be the new number of children.
+
+ The `numchild' field in other varobj responses is generally not
+ valid for a dynamic varobj - it will show the number of children
+ that GDB knows about, but because dynamic varobjs lazily
+ instantiate their children, this will not reflect the number of
+ children which may be available.
+
+ The `new_num_children' attribute only reports changes to the
+ number of children known by GDB. This is the only way to detect
+ whether an update has removed children (which necessarily can only
+ happen at the end of the update range).
+
+`displayhint'
+ The display hint, if any.
+
+`has_more'
+ This is an integer value, which will be 1 if there are more
+ children available outside the varobj's update range.
+
+`dynamic'
+ This attribute will be present and have the value `1' if the
+ varobj is a dynamic varobj. If the varobj is not a dynamic varobj,
+ then this attribute will not be present.
+
+`new_children'
+ If new children were added to a dynamic varobj within the selected
+ update range (as set by `-var-set-update-range'), then they will
+ be listed in this attribute.
+
+Example
+.......
+
+ (gdb)
+ -var-assign var1 3
+ ^done,value="3"
+ (gdb)
+ -var-update --all-values var1
+ ^done,changelist=[{name="var1",value="3",in_scope="true",
+ type_changed="false"}]
+ (gdb)
+
+The `-var-set-frozen' Command
+-----------------------------
+
+Synopsis
+........
+
+ -var-set-frozen NAME FLAG
+
+ Set the frozenness flag on the variable object NAME. The FLAG
+parameter should be either `1' to make the variable frozen or `0' to
+make it unfrozen. If a variable object is frozen, then neither itself,
+nor any of its children, are implicitly updated by `-var-update' of a
+parent variable or by `-var-update *'. Only `-var-update' of the
+variable itself will update its value and values of its children.
+After a variable object is unfrozen, it is implicitly updated by all
+subsequent `-var-update' operations. Unfreezing a variable does not
+update it, only subsequent `-var-update' does.
+
+Example
+.......
+
+ (gdb)
+ -var-set-frozen V 1
+ ^done
+ (gdb)
+
+The `-var-set-update-range' command
+-----------------------------------
+
+Synopsis
+........
+
+ -var-set-update-range NAME FROM TO
+
+ Set the range of children to be returned by future invocations of
+`-var-update'.
+
+ FROM and TO indicate the range of children to report. If FROM or TO
+is less than zero, the range is reset and all children will be
+reported. Otherwise, children starting at FROM (zero-based) and up to
+and excluding TO will be reported.
+
+Example
+.......
+
+ (gdb)
+ -var-set-update-range V 1 2
+ ^done
+
+The `-var-set-visualizer' command
+---------------------------------
+
+Synopsis
+........
+
+ -var-set-visualizer NAME VISUALIZER
+
+ Set a visualizer for the variable object NAME.
+
+ VISUALIZER is the visualizer to use. The special value `None' means
+to disable any visualizer in use.
+
+ If not `None', VISUALIZER must be a Python expression. This
+expression must evaluate to a callable object which accepts a single
+argument. GDB will call this object with the value of the varobj NAME
+as an argument (this is done so that the same Python pretty-printing
+code can be used for both the CLI and MI). When called, this object
+must return an object which conforms to the pretty-printing interface
+(*note Pretty Printing API::).
+
+ The pre-defined function `gdb.default_visualizer' may be used to
+select a visualizer by following the built-in process (*note Selecting
+Pretty-Printers::). This is done automatically when a varobj is
+created, and so ordinarily is not needed.
+
+ This feature is only available if Python support is enabled. The MI
+command `-list-features' (*note GDB/MI Miscellaneous Commands::) can be
+used to check this.
+
+Example
+.......
+
+Resetting the visualizer:
+
+ (gdb)
+ -var-set-visualizer V None
+ ^done
+
+ Reselecting the default (type-based) visualizer:
+
+ (gdb)
+ -var-set-visualizer V gdb.default_visualizer
+ ^done
+
+ Suppose `SomeClass' is a visualizer class. A lambda expression can
+be used to instantiate this class for a varobj:
+
+ (gdb)
+ -var-set-visualizer V "lambda val: SomeClass()"
+ ^done
+
+
+File: gdb.info, Node: GDB/MI Data Manipulation, Next: GDB/MI Tracepoint Commands, Prev: GDB/MI Variable Objects, Up: GDB/MI
+
+27.15 GDB/MI Data Manipulation
+==============================
+
+This section describes the GDB/MI commands that manipulate data:
+examine memory and registers, evaluate expressions, etc.
+
+The `-data-disassemble' Command
+-------------------------------
+
+Synopsis
+........
+
+ -data-disassemble
+ [ -s START-ADDR -e END-ADDR ]
+ | [ -f FILENAME -l LINENUM [ -n LINES ] ]
+ -- MODE
+
+Where:
+
+`START-ADDR'
+ is the beginning address (or `$pc')
+
+`END-ADDR'
+ is the end address
+
+`FILENAME'
+ is the name of the file to disassemble
+
+`LINENUM'
+ is the line number to disassemble around
+
+`LINES'
+ is the number of disassembly lines to be produced. If it is -1,
+ the whole function will be disassembled, in case no END-ADDR is
+ specified. If END-ADDR is specified as a non-zero value, and
+ LINES is lower than the number of disassembly lines between
+ START-ADDR and END-ADDR, only LINES lines are displayed; if LINES
+ is higher than the number of lines between START-ADDR and
+ END-ADDR, only the lines up to END-ADDR are displayed.
+
+`MODE'
+ is either 0 (meaning only disassembly), 1 (meaning mixed source and
+ disassembly), 2 (meaning disassembly with raw opcodes), or 3
+ (meaning mixed source and disassembly with raw opcodes).
+
+Result
+......
+
+The output for each instruction is composed of four fields:
+
+ * Address
+
+ * Func-name
+
+ * Offset
+
+ * Instruction
+
+ Note that whatever included in the instruction field, is not
+manipulated directly by GDB/MI, i.e., it is not possible to adjust its
+format.
+
+GDB Command
+...........
+
+There's no direct mapping from this command to the CLI.
+
+Example
+.......
+
+Disassemble from the current value of `$pc' to `$pc + 20':
+
+ (gdb)
+ -data-disassemble -s $pc -e "$pc + 20" -- 0
+ ^done,
+ asm_insns=[
+ {address="0x000107c0",func-name="main",offset="4",
+ inst="mov 2, %o0"},
+ {address="0x000107c4",func-name="main",offset="8",
+ inst="sethi %hi(0x11800), %o2"},
+ {address="0x000107c8",func-name="main",offset="12",
+ inst="or %o2, 0x140, %o1\t! 0x11940 <_lib_version+8>"},
+ {address="0x000107cc",func-name="main",offset="16",
+ inst="sethi %hi(0x11800), %o2"},
+ {address="0x000107d0",func-name="main",offset="20",
+ inst="or %o2, 0x168, %o4\t! 0x11968 <_lib_version+48>"}]
+ (gdb)
+
+ Disassemble the whole `main' function. Line 32 is part of `main'.
+
+ -data-disassemble -f basics.c -l 32 -- 0
+ ^done,asm_insns=[
+ {address="0x000107bc",func-name="main",offset="0",
+ inst="save %sp, -112, %sp"},
+ {address="0x000107c0",func-name="main",offset="4",
+ inst="mov 2, %o0"},
+ {address="0x000107c4",func-name="main",offset="8",
+ inst="sethi %hi(0x11800), %o2"},
+ [...]
+ {address="0x0001081c",func-name="main",offset="96",inst="ret "},
+ {address="0x00010820",func-name="main",offset="100",inst="restore "}]
+ (gdb)
+
+ Disassemble 3 instructions from the start of `main':
+
+ (gdb)
+ -data-disassemble -f basics.c -l 32 -n 3 -- 0
+ ^done,asm_insns=[
+ {address="0x000107bc",func-name="main",offset="0",
+ inst="save %sp, -112, %sp"},
+ {address="0x000107c0",func-name="main",offset="4",
+ inst="mov 2, %o0"},
+ {address="0x000107c4",func-name="main",offset="8",
+ inst="sethi %hi(0x11800), %o2"}]
+ (gdb)
+
+ Disassemble 3 instructions from the start of `main' in mixed mode:
+
+ (gdb)
+ -data-disassemble -f basics.c -l 32 -n 3 -- 1
+ ^done,asm_insns=[
+ src_and_asm_line={line="31",
+ file="/kwikemart/marge/ezannoni/flathead-dev/devo/gdb/ \
+ testsuite/gdb.mi/basics.c",line_asm_insn=[
+ {address="0x000107bc",func-name="main",offset="0",
+ inst="save %sp, -112, %sp"}]},
+ src_and_asm_line={line="32",
+ file="/kwikemart/marge/ezannoni/flathead-dev/devo/gdb/ \
+ testsuite/gdb.mi/basics.c",line_asm_insn=[
+ {address="0x000107c0",func-name="main",offset="4",
+ inst="mov 2, %o0"},
+ {address="0x000107c4",func-name="main",offset="8",
+ inst="sethi %hi(0x11800), %o2"}]}]
+ (gdb)
+
+The `-data-evaluate-expression' Command
+---------------------------------------
+
+Synopsis
+........
+
+ -data-evaluate-expression EXPR
+
+ Evaluate EXPR as an expression. The expression could contain an
+inferior function call. The function call will execute synchronously.
+If the expression contains spaces, it must be enclosed in double quotes.
+
+GDB Command
+...........
+
+The corresponding GDB commands are `print', `output', and `call'. In
+`gdbtk' only, there's a corresponding `gdb_eval' command.
+
+Example
+.......
+
+In the following example, the numbers that precede the commands are the
+"tokens" described in *Note GDB/MI Command Syntax: GDB/MI Command
+Syntax. Notice how GDB/MI returns the same tokens in its output.
+
+ 211-data-evaluate-expression A
+ 211^done,value="1"
+ (gdb)
+ 311-data-evaluate-expression &A
+ 311^done,value="0xefffeb7c"
+ (gdb)
+ 411-data-evaluate-expression A+3
+ 411^done,value="4"
+ (gdb)
+ 511-data-evaluate-expression "A + 3"
+ 511^done,value="4"
+ (gdb)
+
+The `-data-list-changed-registers' Command
+------------------------------------------
+
+Synopsis
+........
+
+ -data-list-changed-registers
+
+ Display a list of the registers that have changed.
+
+GDB Command
+...........
+
+GDB doesn't have a direct analog for this command; `gdbtk' has the
+corresponding command `gdb_changed_register_list'.
+
+Example
+.......
+
+On a PPC MBX board:
+
+ (gdb)
+ -exec-continue
+ ^running
+
+ (gdb)
+ *stopped,reason="breakpoint-hit",disp="keep",bkptno="1",frame={
+ func="main",args=[],file="try.c",fullname="/home/foo/bar/try.c",
+ line="5"}
+ (gdb)
+ -data-list-changed-registers
+ ^done,changed-registers=["0","1","2","4","5","6","7","8","9",
+ "10","11","13","14","15","16","17","18","19","20","21","22","23",
+ "24","25","26","27","28","30","31","64","65","66","67","69"]
+ (gdb)
+
+The `-data-list-register-names' Command
+---------------------------------------
+
+Synopsis
+........
+
+ -data-list-register-names [ ( REGNO )+ ]
+
+ Show a list of register names for the current target. If no
+arguments are given, it shows a list of the names of all the registers.
+If integer numbers are given as arguments, it will print a list of the
+names of the registers corresponding to the arguments. To ensure
+consistency between a register name and its number, the output list may
+include empty register names.
+
+GDB Command
+...........
+
+GDB does not have a command which corresponds to
+`-data-list-register-names'. In `gdbtk' there is a corresponding
+command `gdb_regnames'.
+
+Example
+.......
+
+For the PPC MBX board:
+ (gdb)
+ -data-list-register-names
+ ^done,register-names=["r0","r1","r2","r3","r4","r5","r6","r7",
+ "r8","r9","r10","r11","r12","r13","r14","r15","r16","r17","r18",
+ "r19","r20","r21","r22","r23","r24","r25","r26","r27","r28","r29",
+ "r30","r31","f0","f1","f2","f3","f4","f5","f6","f7","f8","f9",
+ "f10","f11","f12","f13","f14","f15","f16","f17","f18","f19","f20",
+ "f21","f22","f23","f24","f25","f26","f27","f28","f29","f30","f31",
+ "", "pc","ps","cr","lr","ctr","xer"]
+ (gdb)
+ -data-list-register-names 1 2 3
+ ^done,register-names=["r1","r2","r3"]
+ (gdb)
+
+The `-data-list-register-values' Command
+----------------------------------------
+
+Synopsis
+........
+
+ -data-list-register-values FMT [ ( REGNO )*]
+
+ Display the registers' contents. FMT is the format according to
+which the registers' contents are to be returned, followed by an
+optional list of numbers specifying the registers to display. A
+missing list of numbers indicates that the contents of all the
+registers must be returned.
+
+ Allowed formats for FMT are:
+
+`x'
+ Hexadecimal
+
+`o'
+ Octal
+
+`t'
+ Binary
+
+`d'
+ Decimal
+
+`r'
+ Raw
+
+`N'
+ Natural
+
+GDB Command
+...........
+
+The corresponding GDB commands are `info reg', `info all-reg', and (in
+`gdbtk') `gdb_fetch_registers'.
+
+Example
+.......
+
+For a PPC MBX board (note: line breaks are for readability only, they
+don't appear in the actual output):
+
+ (gdb)
+ -data-list-register-values r 64 65
+ ^done,register-values=[{number="64",value="0xfe00a300"},
+ {number="65",value="0x00029002"}]
+ (gdb)
+ -data-list-register-values x
+ ^done,register-values=[{number="0",value="0xfe0043c8"},
+ {number="1",value="0x3fff88"},{number="2",value="0xfffffffe"},
+ {number="3",value="0x0"},{number="4",value="0xa"},
+ {number="5",value="0x3fff68"},{number="6",value="0x3fff58"},
+ {number="7",value="0xfe011e98"},{number="8",value="0x2"},
+ {number="9",value="0xfa202820"},{number="10",value="0xfa202808"},
+ {number="11",value="0x1"},{number="12",value="0x0"},
+ {number="13",value="0x4544"},{number="14",value="0xffdfffff"},
+ {number="15",value="0xffffffff"},{number="16",value="0xfffffeff"},
+ {number="17",value="0xefffffed"},{number="18",value="0xfffffffe"},
+ {number="19",value="0xffffffff"},{number="20",value="0xffffffff"},
+ {number="21",value="0xffffffff"},{number="22",value="0xfffffff7"},
+ {number="23",value="0xffffffff"},{number="24",value="0xffffffff"},
+ {number="25",value="0xffffffff"},{number="26",value="0xfffffffb"},
+ {number="27",value="0xffffffff"},{number="28",value="0xf7bfffff"},
+ {number="29",value="0x0"},{number="30",value="0xfe010000"},
+ {number="31",value="0x0"},{number="32",value="0x0"},
+ {number="33",value="0x0"},{number="34",value="0x0"},
+ {number="35",value="0x0"},{number="36",value="0x0"},
+ {number="37",value="0x0"},{number="38",value="0x0"},
+ {number="39",value="0x0"},{number="40",value="0x0"},
+ {number="41",value="0x0"},{number="42",value="0x0"},
+ {number="43",value="0x0"},{number="44",value="0x0"},
+ {number="45",value="0x0"},{number="46",value="0x0"},
+ {number="47",value="0x0"},{number="48",value="0x0"},
+ {number="49",value="0x0"},{number="50",value="0x0"},
+ {number="51",value="0x0"},{number="52",value="0x0"},
+ {number="53",value="0x0"},{number="54",value="0x0"},
+ {number="55",value="0x0"},{number="56",value="0x0"},
+ {number="57",value="0x0"},{number="58",value="0x0"},
+ {number="59",value="0x0"},{number="60",value="0x0"},
+ {number="61",value="0x0"},{number="62",value="0x0"},
+ {number="63",value="0x0"},{number="64",value="0xfe00a300"},
+ {number="65",value="0x29002"},{number="66",value="0x202f04b5"},
+ {number="67",value="0xfe0043b0"},{number="68",value="0xfe00b3e4"},
+ {number="69",value="0x20002b03"}]
+ (gdb)
+
+The `-data-read-memory' Command
+-------------------------------
+
+This command is deprecated, use `-data-read-memory-bytes' instead.
+
+Synopsis
+........
+
+ -data-read-memory [ -o BYTE-OFFSET ]
+ ADDRESS WORD-FORMAT WORD-SIZE
+ NR-ROWS NR-COLS [ ASCHAR ]
+
+where:
+
+`ADDRESS'
+ An expression specifying the address of the first memory word to be
+ read. Complex expressions containing embedded white space should
+ be quoted using the C convention.
+
+`WORD-FORMAT'
+ The format to be used to print the memory words. The notation is
+ the same as for GDB's `print' command (*note Output Formats:
+ Output Formats.).
+
+`WORD-SIZE'
+ The size of each memory word in bytes.
+
+`NR-ROWS'
+ The number of rows in the output table.
+
+`NR-COLS'
+ The number of columns in the output table.
+
+`ASCHAR'
+ If present, indicates that each row should include an ASCII dump.
+ The value of ASCHAR is used as a padding character when a byte is
+ not a member of the printable ASCII character set (printable ASCII
+ characters are those whose code is between 32 and 126,
+ inclusively).
+
+`BYTE-OFFSET'
+ An offset to add to the ADDRESS before fetching memory.
+
+ This command displays memory contents as a table of NR-ROWS by
+NR-COLS words, each word being WORD-SIZE bytes. In total, `NR-ROWS *
+NR-COLS * WORD-SIZE' bytes are read (returned as `total-bytes').
+Should less than the requested number of bytes be returned by the
+target, the missing words are identified using `N/A'. The number of
+bytes read from the target is returned in `nr-bytes' and the starting
+address used to read memory in `addr'.
+
+ The address of the next/previous row or page is available in
+`next-row' and `prev-row', `next-page' and `prev-page'.
+
+GDB Command
+...........
+
+The corresponding GDB command is `x'. `gdbtk' has `gdb_get_mem' memory
+read command.
+
+Example
+.......
+
+Read six bytes of memory starting at `bytes+6' but then offset by `-6'
+bytes. Format as three rows of two columns. One byte per word.
+Display each word in hex.
+
+ (gdb)
+ 9-data-read-memory -o -6 -- bytes+6 x 1 3 2
+ 9^done,addr="0x00001390",nr-bytes="6",total-bytes="6",
+ next-row="0x00001396",prev-row="0x0000138e",next-page="0x00001396",
+ prev-page="0x0000138a",memory=[
+ {addr="0x00001390",data=["0x00","0x01"]},
+ {addr="0x00001392",data=["0x02","0x03"]},
+ {addr="0x00001394",data=["0x04","0x05"]}]
+ (gdb)
+
+ Read two bytes of memory starting at address `shorts + 64' and
+display as a single word formatted in decimal.
+
+ (gdb)
+ 5-data-read-memory shorts+64 d 2 1 1
+ 5^done,addr="0x00001510",nr-bytes="2",total-bytes="2",
+ next-row="0x00001512",prev-row="0x0000150e",
+ next-page="0x00001512",prev-page="0x0000150e",memory=[
+ {addr="0x00001510",data=["128"]}]
+ (gdb)
+
+ Read thirty two bytes of memory starting at `bytes+16' and format as
+eight rows of four columns. Include a string encoding with `x' used as
+the non-printable character.
+
+ (gdb)
+ 4-data-read-memory bytes+16 x 1 8 4 x
+ 4^done,addr="0x000013a0",nr-bytes="32",total-bytes="32",
+ next-row="0x000013c0",prev-row="0x0000139c",
+ next-page="0x000013c0",prev-page="0x00001380",memory=[
+ {addr="0x000013a0",data=["0x10","0x11","0x12","0x13"],ascii="xxxx"},
+ {addr="0x000013a4",data=["0x14","0x15","0x16","0x17"],ascii="xxxx"},
+ {addr="0x000013a8",data=["0x18","0x19","0x1a","0x1b"],ascii="xxxx"},
+ {addr="0x000013ac",data=["0x1c","0x1d","0x1e","0x1f"],ascii="xxxx"},
+ {addr="0x000013b0",data=["0x20","0x21","0x22","0x23"],ascii=" !\"#"},
+ {addr="0x000013b4",data=["0x24","0x25","0x26","0x27"],ascii="$%&'"},
+ {addr="0x000013b8",data=["0x28","0x29","0x2a","0x2b"],ascii="()*+"},
+ {addr="0x000013bc",data=["0x2c","0x2d","0x2e","0x2f"],ascii=",-./"}]
+ (gdb)
+
+The `-data-read-memory-bytes' Command
+-------------------------------------
+
+Synopsis
+........
+
+ -data-read-memory-bytes [ -o BYTE-OFFSET ]
+ ADDRESS COUNT
+
+where:
+
+`ADDRESS'
+ An expression specifying the address of the first memory word to be
+ read. Complex expressions containing embedded white space should
+ be quoted using the C convention.
+
+`COUNT'
+ The number of bytes to read. This should be an integer literal.
+
+`BYTE-OFFSET'
+ The offsets in bytes relative to ADDRESS at which to start
+ reading. This should be an integer literal. This option is
+ provided so that a frontend is not required to first evaluate
+ address and then perform address arithmetics itself.
+
+
+ This command attempts to read all accessible memory regions in the
+specified range. First, all regions marked as unreadable in the memory
+map (if one is defined) will be skipped. *Note Memory Region
+Attributes::. Second, GDB will attempt to read the remaining regions.
+For each one, if reading full region results in an errors, GDB will try
+to read a subset of the region.
+
+ In general, every single byte in the region may be readable or not,
+and the only way to read every readable byte is to try a read at every
+address, which is not practical. Therefore, GDB will attempt to read
+all accessible bytes at either beginning or the end of the region,
+using a binary division scheme. This heuristic works well for reading
+accross a memory map boundary. Note that if a region has a readable
+range that is neither at the beginning or the end, GDB will not read it.
+
+ The result record (*note GDB/MI Result Records::) that is output of
+the command includes a field named `memory' whose content is a list of
+tuples. Each tuple represent a successfully read memory block and has
+the following fields:
+
+`begin'
+ The start address of the memory block, as hexadecimal literal.
+
+`end'
+ The end address of the memory block, as hexadecimal literal.
+
+`offset'
+ The offset of the memory block, as hexadecimal literal, relative to
+ the start address passed to `-data-read-memory-bytes'.
+
+`contents'
+ The contents of the memory block, in hex.
+
+
+GDB Command
+...........
+
+The corresponding GDB command is `x'.
+
+Example
+.......
+
+ (gdb)
+ -data-read-memory-bytes &a 10
+ ^done,memory=[{begin="0xbffff154",offset="0x00000000",
+ end="0xbffff15e",
+ contents="01000000020000000300"}]
+ (gdb)
+
+The `-data-write-memory-bytes' Command
+--------------------------------------
+
+Synopsis
+........
+
+ -data-write-memory-bytes ADDRESS CONTENTS
+
+where:
+
+`ADDRESS'
+ An expression specifying the address of the first memory word to be
+ read. Complex expressions containing embedded white space should
+ be quoted using the C convention.
+
+`CONTENTS'
+ The hex-encoded bytes to write.
+
+
+GDB Command
+...........
+
+There's no corresponding GDB command.
+
+Example
+.......
+
+ (gdb)
+ -data-write-memory-bytes &a "aabbccdd"
+ ^done
+ (gdb)
+
+
+File: gdb.info, Node: GDB/MI Tracepoint Commands, Next: GDB/MI Symbol Query, Prev: GDB/MI Data Manipulation, Up: GDB/MI
+
+27.16 GDB/MI Tracepoint Commands
+================================
+
+The commands defined in this section implement MI support for
+tracepoints. For detailed introduction, see *Note Tracepoints::.
+
+The `-trace-find' Command
+-------------------------
+
+Synopsis
+........
+
+ -trace-find MODE [PARAMETERS...]
+
+ Find a trace frame using criteria defined by MODE and PARAMETERS.
+The following table lists permissible modes and their parameters. For
+details of operation, see *Note tfind::.
+
+`none'
+ No parameters are required. Stops examining trace frames.
+
+`frame-number'
+ An integer is required as parameter. Selects tracepoint frame with
+ that index.
+
+`tracepoint-number'
+ An integer is required as parameter. Finds next trace frame that
+ corresponds to tracepoint with the specified number.
+
+`pc'
+ An address is required as parameter. Finds next trace frame that
+ corresponds to any tracepoint at the specified address.
+
+`pc-inside-range'
+ Two addresses are required as parameters. Finds next trace frame
+ that corresponds to a tracepoint at an address inside the
+ specified range. Both bounds are considered to be inside the
+ range.
+
+`pc-outside-range'
+ Two addresses are required as parameters. Finds next trace frame
+ that corresponds to a tracepoint at an address outside the
+ specified range. Both bounds are considered to be inside the
+ range.
+
+`line'
+ Line specification is required as parameter. *Note Specify
+ Location::. Finds next trace frame that corresponds to a
+ tracepoint at the specified location.
+
+
+ If `none' was passed as MODE, the response does not have fields.
+Otherwise, the response may have the following fields:
+
+`found'
+ This field has either `0' or `1' as the value, depending on
+ whether a matching tracepoint was found.
+
+`traceframe'
+ The index of the found traceframe. This field is present iff the
+ `found' field has value of `1'.
+
+`tracepoint'
+ The index of the found tracepoint. This field is present iff the
+ `found' field has value of `1'.
+
+`frame'
+ The information about the frame corresponding to the found trace
+ frame. This field is present only if a trace frame was found.
+ *Note GDB/MI Frame Information::, for description of this field.
+
+
+GDB Command
+...........
+
+The corresponding GDB command is `tfind'.
+
+-trace-define-variable
+----------------------
+
+Synopsis
+........
+
+ -trace-define-variable NAME [ VALUE ]
+
+ Create trace variable NAME if it does not exist. If VALUE is
+specified, sets the initial value of the specified trace variable to
+that value. Note that the NAME should start with the `$' character.
+
+GDB Command
+...........
+
+The corresponding GDB command is `tvariable'.
+
+-trace-list-variables
+---------------------
+
+Synopsis
+........
+
+ -trace-list-variables
+
+ Return a table of all defined trace variables. Each element of the
+table has the following fields:
+
+`name'
+ The name of the trace variable. This field is always present.
+
+`initial'
+ The initial value. This is a 64-bit signed integer. This field
+ is always present.
+
+`current'
+ The value the trace variable has at the moment. This is a 64-bit
+ signed integer. This field is absent iff current value is not
+ defined, for example if the trace was never run, or is presently
+ running.
+
+
+GDB Command
+...........
+
+The corresponding GDB command is `tvariables'.
+
+Example
+.......
+
+ (gdb)
+ -trace-list-variables
+ ^done,trace-variables={nr_rows="1",nr_cols="3",
+ hdr=[{width="15",alignment="-1",col_name="name",colhdr="Name"},
+ {width="11",alignment="-1",col_name="initial",colhdr="Initial"},
+ {width="11",alignment="-1",col_name="current",colhdr="Current"}],
+ body=[variable={name="$trace_timestamp",initial="0"}
+ variable={name="$foo",initial="10",current="15"}]}
+ (gdb)
+
+-trace-save
+-----------
+
+Synopsis
+........
+
+ -trace-save [-r ] FILENAME
+
+ Saves the collected trace data to FILENAME. Without the `-r'
+option, the data is downloaded from the target and saved in a local
+file. With the `-r' option the target is asked to perform the save.
+
+GDB Command
+...........
+
+The corresponding GDB command is `tsave'.
+
+-trace-start
+------------
+
+Synopsis
+........
+
+ -trace-start
+
+ Starts a tracing experiments. The result of this command does not
+have any fields.
+
+GDB Command
+...........
+
+The corresponding GDB command is `tstart'.
+
+-trace-status
+-------------
+
+Synopsis
+........
+
+ -trace-status
+
+ Obtains the status of a tracing experiment. The result may include
+the following fields:
+
+`supported'
+ May have a value of either `0', when no tracing operations are
+ supported, `1', when all tracing operations are supported, or
+ `file' when examining trace file. In the latter case, examining
+ of trace frame is possible but new tracing experiement cannot be
+ started. This field is always present.
+
+`running'
+ May have a value of either `0' or `1' depending on whether tracing
+ experiement is in progress on target. This field is present if
+ `supported' field is not `0'.
+
+`stop-reason'
+ Report the reason why the tracing was stopped last time. This
+ field may be absent iff tracing was never stopped on target yet.
+ The value of `request' means the tracing was stopped as result of
+ the `-trace-stop' command. The value of `overflow' means the
+ tracing buffer is full. The value of `disconnection' means
+ tracing was automatically stopped when GDB has disconnected. The
+ value of `passcount' means tracing was stopped when a tracepoint
+ was passed a maximal number of times for that tracepoint. This
+ field is present if `supported' field is not `0'.
+
+`stopping-tracepoint'
+ The number of tracepoint whose passcount as exceeded. This field
+ is present iff the `stop-reason' field has the value of
+ `passcount'.
+
+`frames'
+`frames-created'
+ The `frames' field is a count of the total number of trace frames
+ in the trace buffer, while `frames-created' is the total created
+ during the run, including ones that were discarded, such as when a
+ circular trace buffer filled up. Both fields are optional.
+
+`buffer-size'
+`buffer-free'
+ These fields tell the current size of the tracing buffer and the
+ remaining space. These fields are optional.
+
+`circular'
+ The value of the circular trace buffer flag. `1' means that the
+ trace buffer is circular and old trace frames will be discarded if
+ necessary to make room, `0' means that the trace buffer is linear
+ and may fill up.
+
+`disconnected'
+ The value of the disconnected tracing flag. `1' means that
+ tracing will continue after GDB disconnects, `0' means that the
+ trace run will stop.
+
+
+GDB Command
+...........
+
+The corresponding GDB command is `tstatus'.
+
+-trace-stop
+-----------
+
+Synopsis
+........
+
+ -trace-stop
+
+ Stops a tracing experiment. The result of this command has the same
+fields as `-trace-status', except that the `supported' and `running'
+fields are not output.
+
+GDB Command
+...........
+
+The corresponding GDB command is `tstop'.
+
+
+File: gdb.info, Node: GDB/MI Symbol Query, Next: GDB/MI File Commands, Prev: GDB/MI Tracepoint Commands, Up: GDB/MI
+
+27.17 GDB/MI Symbol Query Commands
+==================================
+
+The `-symbol-list-lines' Command
+--------------------------------
+
+Synopsis
+........
+
+ -symbol-list-lines FILENAME
+
+ Print the list of lines that contain code and their associated
+program addresses for the given source filename. The entries are
+sorted in ascending PC order.
+
+GDB Command
+...........
+
+There is no corresponding GDB command.
+
+Example
+.......
+
+ (gdb)
+ -symbol-list-lines basics.c
+ ^done,lines=[{pc="0x08048554",line="7"},{pc="0x0804855a",line="8"}]
+ (gdb)
+
+
+File: gdb.info, Node: GDB/MI File Commands, Next: GDB/MI Target Manipulation, Prev: GDB/MI Symbol Query, Up: GDB/MI
+
+27.18 GDB/MI File Commands
+==========================
+
+This section describes the GDB/MI commands to specify executable file
+names and to read in and obtain symbol table information.
+
+The `-file-exec-and-symbols' Command
+------------------------------------
+
+Synopsis
+........
+
+ -file-exec-and-symbols FILE
+
+ Specify the executable file to be debugged. This file is the one
+from which the symbol table is also read. If no file is specified, the
+command clears the executable and symbol information. If breakpoints
+are set when using this command with no arguments, GDB will produce
+error messages. Otherwise, no output is produced, except a completion
+notification.
+
+GDB Command
+...........
+
+The corresponding GDB command is `file'.
+
+Example
+.......
+
+ (gdb)
+ -file-exec-and-symbols /kwikemart/marge/ezannoni/TRUNK/mbx/hello.mbx
+ ^done
+ (gdb)
+
+The `-file-exec-file' Command
+-----------------------------
+
+Synopsis
+........
+
+ -file-exec-file FILE
+
+ Specify the executable file to be debugged. Unlike
+`-file-exec-and-symbols', the symbol table is _not_ read from this
+file. If used without argument, GDB clears the information about the
+executable file. No output is produced, except a completion
+notification.
+
+GDB Command
+...........
+
+The corresponding GDB command is `exec-file'.
+
+Example
+.......
+
+ (gdb)
+ -file-exec-file /kwikemart/marge/ezannoni/TRUNK/mbx/hello.mbx
+ ^done
+ (gdb)
+
+The `-file-list-exec-source-file' Command
+-----------------------------------------
+
+Synopsis
+........
+
+ -file-list-exec-source-file
+
+ List the line number, the current source file, and the absolute path
+to the current source file for the current executable. The macro
+information field has a value of `1' or `0' depending on whether or not
+the file includes preprocessor macro information.
+
+GDB Command
+...........
+
+The GDB equivalent is `info source'
+
+Example
+.......
+
+ (gdb)
+ 123-file-list-exec-source-file
+ 123^done,line="1",file="foo.c",fullname="/home/bar/foo.c,macro-info="1"
+ (gdb)
+
+The `-file-list-exec-source-files' Command
+------------------------------------------
+
+Synopsis
+........
+
+ -file-list-exec-source-files
+
+ List the source files for the current executable.
+
+ It will always output the filename, but only when GDB can find the
+absolute file name of a source file, will it output the fullname.
+
+GDB Command
+...........
+
+The GDB equivalent is `info sources'. `gdbtk' has an analogous command
+`gdb_listfiles'.
+
+Example
+.......
+
+ (gdb)
+ -file-list-exec-source-files
+ ^done,files=[
+ {file=foo.c,fullname=/home/foo.c},
+ {file=/home/bar.c,fullname=/home/bar.c},
+ {file=gdb_could_not_find_fullpath.c}]
+ (gdb)
+
+The `-file-symbol-file' Command
+-------------------------------
+
+Synopsis
+........
+
+ -file-symbol-file FILE
+
+ Read symbol table info from the specified FILE argument. When used
+without arguments, clears GDB's symbol table info. No output is
+produced, except for a completion notification.
+
+GDB Command
+...........
+
+The corresponding GDB command is `symbol-file'.
+
+Example
+.......
+
+ (gdb)
+ -file-symbol-file /kwikemart/marge/ezannoni/TRUNK/mbx/hello.mbx
+ ^done
+ (gdb)
+
+
+File: gdb.info, Node: GDB/MI Target Manipulation, Next: GDB/MI File Transfer Commands, Prev: GDB/MI File Commands, Up: GDB/MI
+
+27.19 GDB/MI Target Manipulation Commands
+=========================================
+
+The `-target-attach' Command
+----------------------------
+
+Synopsis
+........
+
+ -target-attach PID | GID | FILE
+
+ Attach to a process PID or a file FILE outside of GDB, or a thread
+group GID. If attaching to a thread group, the id previously returned
+by `-list-thread-groups --available' must be used.
+
+GDB Command
+...........
+
+The corresponding GDB command is `attach'.
+
+Example
+.......
+
+ (gdb)
+ -target-attach 34
+ =thread-created,id="1"
+ *stopped,thread-id="1",frame={addr="0xb7f7e410",func="bar",args=[]}
+ ^done
+ (gdb)
+
+The `-target-detach' Command
+----------------------------
+
+Synopsis
+........
+
+ -target-detach [ PID | GID ]
+
+ Detach from the remote target which normally resumes its execution.
+If either PID or GID is specified, detaches from either the specified
+process, or specified thread group. There's no output.
+
+GDB Command
+...........
+
+The corresponding GDB command is `detach'.
+
+Example
+.......
+
+ (gdb)
+ -target-detach
+ ^done
+ (gdb)
+
+The `-target-disconnect' Command
+--------------------------------
+
+Synopsis
+........
+
+ -target-disconnect
+
+ Disconnect from the remote target. There's no output and the target
+is generally not resumed.
+
+GDB Command
+...........
+
+The corresponding GDB command is `disconnect'.
+
+Example
+.......
+
+ (gdb)
+ -target-disconnect
+ ^done
+ (gdb)
+
+The `-target-download' Command
+------------------------------
+
+Synopsis
+........
+
+ -target-download
+
+ Loads the executable onto the remote target. It prints out an
+update message every half second, which includes the fields:
+
+`section'
+ The name of the section.
+
+`section-sent'
+ The size of what has been sent so far for that section.
+
+`section-size'
+ The size of the section.
+
+`total-sent'
+ The total size of what was sent so far (the current and the
+ previous sections).
+
+`total-size'
+ The size of the overall executable to download.
+
+Each message is sent as status record (*note GDB/MI Output Syntax:
+GDB/MI Output Syntax.).
+
+ In addition, it prints the name and size of the sections, as they are
+downloaded. These messages include the following fields:
+
+`section'
+ The name of the section.
+
+`section-size'
+ The size of the section.
+
+`total-size'
+ The size of the overall executable to download.
+
+At the end, a summary is printed.
+
+GDB Command
+...........
+
+The corresponding GDB command is `load'.
+
+Example
+.......
+
+Note: each status message appears on a single line. Here the messages
+have been broken down so that they can fit onto a page.
+
+ (gdb)
+ -target-download
+ +download,{section=".text",section-size="6668",total-size="9880"}
+ +download,{section=".text",section-sent="512",section-size="6668",
+ total-sent="512",total-size="9880"}
+ +download,{section=".text",section-sent="1024",section-size="6668",
+ total-sent="1024",total-size="9880"}
+ +download,{section=".text",section-sent="1536",section-size="6668",
+ total-sent="1536",total-size="9880"}
+ +download,{section=".text",section-sent="2048",section-size="6668",
+ total-sent="2048",total-size="9880"}
+ +download,{section=".text",section-sent="2560",section-size="6668",
+ total-sent="2560",total-size="9880"}
+ +download,{section=".text",section-sent="3072",section-size="6668",
+ total-sent="3072",total-size="9880"}
+ +download,{section=".text",section-sent="3584",section-size="6668",
+ total-sent="3584",total-size="9880"}
+ +download,{section=".text",section-sent="4096",section-size="6668",
+ total-sent="4096",total-size="9880"}
+ +download,{section=".text",section-sent="4608",section-size="6668",
+ total-sent="4608",total-size="9880"}
+ +download,{section=".text",section-sent="5120",section-size="6668",
+ total-sent="5120",total-size="9880"}
+ +download,{section=".text",section-sent="5632",section-size="6668",
+ total-sent="5632",total-size="9880"}
+ +download,{section=".text",section-sent="6144",section-size="6668",
+ total-sent="6144",total-size="9880"}
+ +download,{section=".text",section-sent="6656",section-size="6668",
+ total-sent="6656",total-size="9880"}
+ +download,{section=".init",section-size="28",total-size="9880"}
+ +download,{section=".fini",section-size="28",total-size="9880"}
+ +download,{section=".data",section-size="3156",total-size="9880"}
+ +download,{section=".data",section-sent="512",section-size="3156",
+ total-sent="7236",total-size="9880"}
+ +download,{section=".data",section-sent="1024",section-size="3156",
+ total-sent="7748",total-size="9880"}
+ +download,{section=".data",section-sent="1536",section-size="3156",
+ total-sent="8260",total-size="9880"}
+ +download,{section=".data",section-sent="2048",section-size="3156",
+ total-sent="8772",total-size="9880"}
+ +download,{section=".data",section-sent="2560",section-size="3156",
+ total-sent="9284",total-size="9880"}
+ +download,{section=".data",section-sent="3072",section-size="3156",
+ total-sent="9796",total-size="9880"}
+ ^done,address="0x10004",load-size="9880",transfer-rate="6586",
+ write-rate="429"
+ (gdb)
+
+GDB Command
+...........
+
+No equivalent.
+
+Example
+.......
+
+N.A.
+
+The `-target-select' Command
+----------------------------
+
+Synopsis
+........
+
+ -target-select TYPE PARAMETERS ...
+
+ Connect GDB to the remote target. This command takes two args:
+
+`TYPE'
+ The type of target, for instance `remote', etc.
+
+`PARAMETERS'
+ Device names, host names and the like. *Note Commands for
+ Managing Targets: Target Commands, for more details.
+
+ The output is a connection notification, followed by the address at
+which the target program is, in the following form:
+
+ ^connected,addr="ADDRESS",func="FUNCTION NAME",
+ args=[ARG LIST]
+
+GDB Command
+...........
+
+The corresponding GDB command is `target'.
+
+Example
+.......
+
+ (gdb)
+ -target-select remote /dev/ttya
+ ^connected,addr="0xfe00a300",func="??",args=[]
+ (gdb)
+
+
+File: gdb.info, Node: GDB/MI File Transfer Commands, Next: GDB/MI Miscellaneous Commands, Prev: GDB/MI Target Manipulation, Up: GDB/MI
+
+27.20 GDB/MI File Transfer Commands
+===================================
+
+The `-target-file-put' Command
+------------------------------
+
+Synopsis
+........
+
+ -target-file-put HOSTFILE TARGETFILE
+
+ Copy file HOSTFILE from the host system (the machine running GDB) to
+TARGETFILE on the target system.
+
+GDB Command
+...........
+
+The corresponding GDB command is `remote put'.
+
+Example
+.......
+
+ (gdb)
+ -target-file-put localfile remotefile
+ ^done
+ (gdb)
+
+The `-target-file-get' Command
+------------------------------
+
+Synopsis
+........
+
+ -target-file-get TARGETFILE HOSTFILE
+
+ Copy file TARGETFILE from the target system to HOSTFILE on the host
+system.
+
+GDB Command
+...........
+
+The corresponding GDB command is `remote get'.
+
+Example
+.......
+
+ (gdb)
+ -target-file-get remotefile localfile
+ ^done
+ (gdb)
+
+The `-target-file-delete' Command
+---------------------------------
+
+Synopsis
+........
+
+ -target-file-delete TARGETFILE
+
+ Delete TARGETFILE from the target system.
+
+GDB Command
+...........
+
+The corresponding GDB command is `remote delete'.
+
+Example
+.......
+
+ (gdb)
+ -target-file-delete remotefile
+ ^done
+ (gdb)
+
+
+File: gdb.info, Node: GDB/MI Miscellaneous Commands, Prev: GDB/MI File Transfer Commands, Up: GDB/MI
+
+27.21 Miscellaneous GDB/MI Commands
+===================================
+
+The `-gdb-exit' Command
+-----------------------
+
+Synopsis
+........
+
+ -gdb-exit
+
+ Exit GDB immediately.
+
+GDB Command
+...........
+
+Approximately corresponds to `quit'.
+
+Example
+.......
+
+ (gdb)
+ -gdb-exit
+ ^exit
+
+The `-gdb-set' Command
+----------------------
+
+Synopsis
+........
+
+ -gdb-set
+
+ Set an internal GDB variable.
+
+GDB Command
+...........
+
+The corresponding GDB command is `set'.
+
+Example
+.......
+
+ (gdb)
+ -gdb-set $foo=3
+ ^done
+ (gdb)
+
+The `-gdb-show' Command
+-----------------------
+
+Synopsis
+........
+
+ -gdb-show
+
+ Show the current value of a GDB variable.
+
+GDB Command
+...........
+
+The corresponding GDB command is `show'.
+
+Example
+.......
+
+ (gdb)
+ -gdb-show annotate
+ ^done,value="0"
+ (gdb)
+
+The `-gdb-version' Command
+--------------------------
+
+Synopsis
+........
+
+ -gdb-version
+
+ Show version information for GDB. Used mostly in testing.
+
+GDB Command
+...........
+
+The GDB equivalent is `show version'. GDB by default shows this
+information when you start an interactive session.
+
+Example
+.......
+
+ (gdb)
+ -gdb-version
+ ~GNU gdb 5.2.1
+ ~Copyright 2000 Free Software Foundation, Inc.
+ ~GDB is free software, covered by the GNU General Public License, and
+ ~you are welcome to change it and/or distribute copies of it under
+ ~ certain conditions.
+ ~Type "show copying" to see the conditions.
+ ~There is absolutely no warranty for GDB. Type "show warranty" for
+ ~ details.
+ ~This GDB was configured as
+ "--host=sparc-sun-solaris2.5.1 --target=ppc-eabi".
+ ^done
+ (gdb)
+
+The `-list-features' Command
+----------------------------
+
+Returns a list of particular features of the MI protocol that this
+version of gdb implements. A feature can be a command, or a new field
+in an output of some command, or even an important bugfix. While a
+frontend can sometimes detect presence of a feature at runtime, it is
+easier to perform detection at debugger startup.
+
+ The command returns a list of strings, with each string naming an
+available feature. Each returned string is just a name, it does not
+have any internal structure. The list of possible feature names is
+given below.
+
+ Example output:
+
+ (gdb) -list-features
+ ^done,result=["feature1","feature2"]
+
+ The current list of features is:
+
+`frozen-varobjs'
+ Indicates support for the `-var-set-frozen' command, as well as
+ possible presense of the `frozen' field in the output of
+ `-varobj-create'.
+
+`pending-breakpoints'
+ Indicates support for the `-f' option to the `-break-insert'
+ command.
+
+`python'
+ Indicates Python scripting support, Python-based pretty-printing
+ commands, and possible presence of the `display_hint' field in the
+ output of `-var-list-children'
+
+`thread-info'
+ Indicates support for the `-thread-info' command.
+
+`data-read-memory-bytes'
+ Indicates support for the `-data-read-memory-bytes' and the
+ `-data-write-memory-bytes' commands.
+
+`breakpoint-notifications'
+ Indicates that changes to breakpoints and breakpoints created via
+ the CLI will be announced via async records.
+
+`ada-task-info'
+ Indicates support for the `-ada-task-info' command.
+
+The `-list-target-features' Command
+-----------------------------------
+
+Returns a list of particular features that are supported by the target.
+Those features affect the permitted MI commands, but unlike the
+features reported by the `-list-features' command, the features depend
+on which target GDB is using at the moment. Whenever a target can
+change, due to commands such as `-target-select', `-target-attach' or
+`-exec-run', the list of target features may change, and the frontend
+should obtain it again. Example output:
+
+ (gdb) -list-features
+ ^done,result=["async"]
+
+ The current list of features is:
+
+`async'
+ Indicates that the target is capable of asynchronous command
+ execution, which means that GDB will accept further commands while
+ the target is running.
+
+`reverse'
+ Indicates that the target is capable of reverse execution. *Note
+ Reverse Execution::, for more information.
+
+
+The `-list-thread-groups' Command
+---------------------------------
+
+Synopsis
+--------
+
+ -list-thread-groups [ --available ] [ --recurse 1 ] [ GROUP ... ]
+
+ Lists thread groups (*note Thread groups::). When a single thread
+group is passed as the argument, lists the children of that group.
+When several thread group are passed, lists information about those
+thread groups. Without any parameters, lists information about all
+top-level thread groups.
+
+ Normally, thread groups that are being debugged are reported. With
+the `--available' option, GDB reports thread groups available on the
+target.
+
+ The output of this command may have either a `threads' result or a
+`groups' result. The `thread' result has a list of tuples as value,
+with each tuple describing a thread (*note GDB/MI Thread
+Information::). The `groups' result has a list of tuples as value,
+each tuple describing a thread group. If top-level groups are
+requested (that is, no parameter is passed), or when several groups are
+passed, the output always has a `groups' result. The format of the
+`group' result is described below.
+
+ To reduce the number of roundtrips it's possible to list thread
+groups together with their children, by passing the `--recurse' option
+and the recursion depth. Presently, only recursion depth of 1 is
+permitted. If this option is present, then every reported thread group
+will also include its children, either as `group' or `threads' field.
+
+ In general, any combination of option and parameters is permitted,
+with the following caveats:
+
+ * When a single thread group is passed, the output will typically be
+ the `threads' result. Because threads may not contain anything,
+ the `recurse' option will be ignored.
+
+ * When the `--available' option is passed, limited information may
+ be available. In particular, the list of threads of a process
+ might be inaccessible. Further, specifying specific thread groups
+ might not give any performance advantage over listing all thread
+ groups. The frontend should assume that `-list-thread-groups
+ --available' is always an expensive operation and cache the
+ results.
+
+
+ The `groups' result is a list of tuples, where each tuple may have
+the following fields:
+
+`id'
+ Identifier of the thread group. This field is always present.
+ The identifier is an opaque string; frontends should not try to
+ convert it to an integer, even though it might look like one.
+
+`type'
+ The type of the thread group. At present, only `process' is a
+ valid type.
+
+`pid'
+ The target-specific process identifier. This field is only present
+ for thread groups of type `process' and only if the process exists.
+
+`num_children'
+ The number of children this thread group has. This field may be
+ absent for an available thread group.
+
+`threads'
+ This field has a list of tuples as value, each tuple describing a
+ thread. It may be present if the `--recurse' option is specified,
+ and it's actually possible to obtain the threads.
+
+`cores'
+ This field is a list of integers, each identifying a core that one
+ thread of the group is running on. This field may be absent if
+ such information is not available.
+
+`executable'
+ The name of the executable file that corresponds to this thread
+ group. The field is only present for thread groups of type
+ `process', and only if there is a corresponding executable file.
+
+
+Example
+-------
+
+ gdb
+ -list-thread-groups
+ ^done,groups=[{id="17",type="process",pid="yyy",num_children="2"}]
+ -list-thread-groups 17
+ ^done,threads=[{id="2",target-id="Thread 0xb7e14b90 (LWP 21257)",
+ frame={level="0",addr="0xffffe410",func="__kernel_vsyscall",args=[]},state="running"},
+ {id="1",target-id="Thread 0xb7e156b0 (LWP 21254)",
+ frame={level="0",addr="0x0804891f",func="foo",args=[{name="i",value="10"}],
+ file="/tmp/a.c",fullname="/tmp/a.c",line="158"},state="running"}]]
+ -list-thread-groups --available
+ ^done,groups=[{id="17",type="process",pid="yyy",num_children="2",cores=[1,2]}]
+ -list-thread-groups --available --recurse 1
+ ^done,groups=[{id="17", types="process",pid="yyy",num_children="2",cores=[1,2],
+ threads=[{id="1",target-id="Thread 0xb7e14b90",cores=[1]},
+ {id="2",target-id="Thread 0xb7e14b90",cores=[2]}]},..]
+ -list-thread-groups --available --recurse 1 17 18
+ ^done,groups=[{id="17", types="process",pid="yyy",num_children="2",cores=[1,2],
+ threads=[{id="1",target-id="Thread 0xb7e14b90",cores=[1]},
+ {id="2",target-id="Thread 0xb7e14b90",cores=[2]}]},...]
+
+The `-add-inferior' Command
+---------------------------
+
+Synopsis
+--------
+
+ -add-inferior
+
+ Creates a new inferior (*note Inferiors and Programs::). The created
+inferior is not associated with any executable. Such association may
+be established with the `-file-exec-and-symbols' command (*note GDB/MI
+File Commands::). The command response has a single field,
+`thread-group', whose value is the identifier of the thread group
+corresponding to the new inferior.
+
+Example
+-------
+
+ gdb
+ -add-inferior
+ ^done,thread-group="i3"
+
+The `-interpreter-exec' Command
+-------------------------------
+
+Synopsis
+--------
+
+ -interpreter-exec INTERPRETER COMMAND
+
+ Execute the specified COMMAND in the given INTERPRETER.
+
+GDB Command
+-----------
+
+The corresponding GDB command is `interpreter-exec'.
+
+Example
+-------
+
+ (gdb)
+ -interpreter-exec console "break main"
+ &"During symbol reading, couldn't parse type; debugger out of date?.\n"
+ &"During symbol reading, bad structure-type format.\n"
+ ~"Breakpoint 1 at 0x8074fc6: file ../../src/gdb/main.c, line 743.\n"
+ ^done
+ (gdb)
+
+The `-inferior-tty-set' Command
+-------------------------------
+
+Synopsis
+--------
+
+ -inferior-tty-set /dev/pts/1
+
+ Set terminal for future runs of the program being debugged.
+
+GDB Command
+-----------
+
+The corresponding GDB command is `set inferior-tty' /dev/pts/1.
+
+Example
+-------
+
+ (gdb)
+ -inferior-tty-set /dev/pts/1
+ ^done
+ (gdb)
+
+The `-inferior-tty-show' Command
+--------------------------------
+
+Synopsis
+--------
+
+ -inferior-tty-show
+
+ Show terminal for future runs of program being debugged.
+
+GDB Command
+-----------
+
+The corresponding GDB command is `show inferior-tty'.
+
+Example
+-------
+
+ (gdb)
+ -inferior-tty-set /dev/pts/1
+ ^done
+ (gdb)
+ -inferior-tty-show
+ ^done,inferior_tty_terminal="/dev/pts/1"
+ (gdb)
+
+The `-enable-timings' Command
+-----------------------------
+
+Synopsis
+--------
+
+ -enable-timings [yes | no]
+
+ Toggle the printing of the wallclock, user and system times for an MI
+command as a field in its output. This command is to help frontend
+developers optimize the performance of their code. No argument is
+equivalent to `yes'.
+
+GDB Command
+-----------
+
+No equivalent.
+
+Example
+-------
+
+ (gdb)
+ -enable-timings
+ ^done
+ (gdb)
+ -break-insert main
+ ^done,bkpt={number="1",type="breakpoint",disp="keep",enabled="y",
+ addr="0x080484ed",func="main",file="myprog.c",
+ fullname="/home/nickrob/myprog.c",line="73",times="0"},
+ time={wallclock="0.05185",user="0.00800",system="0.00000"}
+ (gdb)
+ -enable-timings no
+ ^done
+ (gdb)
+ -exec-run
+ ^running
+ (gdb)
+ *stopped,reason="breakpoint-hit",disp="keep",bkptno="1",thread-id="0",
+ frame={addr="0x080484ed",func="main",args=[{name="argc",value="1"},
+ {name="argv",value="0xbfb60364"}],file="myprog.c",
+ fullname="/home/nickrob/myprog.c",line="73"}
+ (gdb)
+
+
+File: gdb.info, Node: Annotations, Next: JIT Interface, Prev: GDB/MI, Up: Top
+
+28 GDB Annotations
+******************
+
+This chapter describes annotations in GDB. Annotations were designed
+to interface GDB to graphical user interfaces or other similar programs
+which want to interact with GDB at a relatively high level.
+
+ The annotation mechanism has largely been superseded by GDB/MI
+(*note GDB/MI::).
+
+* Menu:
+
+* Annotations Overview:: What annotations are; the general syntax.
+* Server Prefix:: Issuing a command without affecting user state.
+* Prompting:: Annotations marking GDB's need for input.
+* Errors:: Annotations for error messages.
+* Invalidation:: Some annotations describe things now invalid.
+* Annotations for Running::
+ Whether the program is running, how it stopped, etc.
+* Source Annotations:: Annotations describing source code.
+
+
+File: gdb.info, Node: Annotations Overview, Next: Server Prefix, Up: Annotations
+
+28.1 What is an Annotation?
+===========================
+
+Annotations start with a newline character, two `control-z' characters,
+and the name of the annotation. If there is no additional information
+associated with this annotation, the name of the annotation is followed
+immediately by a newline. If there is additional information, the name
+of the annotation is followed by a space, the additional information,
+and a newline. The additional information cannot contain newline
+characters.
+
+ Any output not beginning with a newline and two `control-z'
+characters denotes literal output from GDB. Currently there is no need
+for GDB to output a newline followed by two `control-z' characters, but
+if there was such a need, the annotations could be extended with an
+`escape' annotation which means those three characters as output.
+
+ The annotation LEVEL, which is specified using the `--annotate'
+command line option (*note Mode Options::), controls how much
+information GDB prints together with its prompt, values of expressions,
+source lines, and other types of output. Level 0 is for no
+annotations, level 1 is for use when GDB is run as a subprocess of GNU
+Emacs, level 3 is the maximum annotation suitable for programs that
+control GDB, and level 2 annotations have been made obsolete (*note
+Limitations of the Annotation Interface: (annotate)Limitations.).
+
+`set annotate LEVEL'
+ The GDB command `set annotate' sets the level of annotations to
+ the specified LEVEL.
+
+`show annotate'
+ Show the current annotation level.
+
+ This chapter describes level 3 annotations.
+
+ A simple example of starting up GDB with annotations is:
+
+ $ gdb --annotate=3
+ GNU gdb 6.0
+ Copyright 2003 Free Software Foundation, Inc.
+ GDB is free software, covered by the GNU General Public License,
+ and you are welcome to change it and/or distribute copies of it
+ under certain conditions.
+ Type "show copying" to see the conditions.
+ There is absolutely no warranty for GDB. Type "show warranty"
+ for details.
+ This GDB was configured as "i386-pc-linux-gnu"
+
+ ^Z^Zpre-prompt
+ (gdb)
+ ^Z^Zprompt
+ quit
+
+ ^Z^Zpost-prompt
+ $
+
+ Here `quit' is input to GDB; the rest is output from GDB. The three
+lines beginning `^Z^Z' (where `^Z' denotes a `control-z' character) are
+annotations; the rest is output from GDB.
+
+
+File: gdb.info, Node: Server Prefix, Next: Prompting, Prev: Annotations Overview, Up: Annotations
+
+28.2 The Server Prefix
+======================
+
+If you prefix a command with `server ' then it will not affect the
+command history, nor will it affect GDB's notion of which command to
+repeat if <RET> is pressed on a line by itself. This means that
+commands can be run behind a user's back by a front-end in a
+transparent manner.
+
+ The `server ' prefix does not affect the recording of values into
+the value history; to print a value without recording it into the value
+history, use the `output' command instead of the `print' command.
+
+ Using this prefix also disables confirmation requests (*note
+confirmation requests::).
+
+
+File: gdb.info, Node: Prompting, Next: Errors, Prev: Server Prefix, Up: Annotations
+
+28.3 Annotation for GDB Input
+=============================
+
+When GDB prompts for input, it annotates this fact so it is possible to
+know when to send output, when the output from a given command is over,
+etc.
+
+ Different kinds of input each have a different "input type". Each
+input type has three annotations: a `pre-' annotation, which denotes
+the beginning of any prompt which is being output, a plain annotation,
+which denotes the end of the prompt, and then a `post-' annotation
+which denotes the end of any echo which may (or may not) be associated
+with the input. For example, the `prompt' input type features the
+following annotations:
+
+ ^Z^Zpre-prompt
+ ^Z^Zprompt
+ ^Z^Zpost-prompt
+
+ The input types are
+
+`prompt'
+ When GDB is prompting for a command (the main GDB prompt).
+
+`commands'
+ When GDB prompts for a set of commands, like in the `commands'
+ command. The annotations are repeated for each command which is
+ input.
+
+`overload-choice'
+ When GDB wants the user to select between various overloaded
+ functions.
+
+`query'
+ When GDB wants the user to confirm a potentially dangerous
+ operation.
+
+`prompt-for-continue'
+ When GDB is asking the user to press return to continue. Note:
+ Don't expect this to work well; instead use `set height 0' to
+ disable prompting. This is because the counting of lines is buggy
+ in the presence of annotations.
+
+
+File: gdb.info, Node: Errors, Next: Invalidation, Prev: Prompting, Up: Annotations
+
+28.4 Errors
+===========
+
+ ^Z^Zquit
+
+ This annotation occurs right before GDB responds to an interrupt.
+
+ ^Z^Zerror
+
+ This annotation occurs right before GDB responds to an error.
+
+ Quit and error annotations indicate that any annotations which GDB
+was in the middle of may end abruptly. For example, if a
+`value-history-begin' annotation is followed by a `error', one cannot
+expect to receive the matching `value-history-end'. One cannot expect
+not to receive it either, however; an error annotation does not
+necessarily mean that GDB is immediately returning all the way to the
+top level.
+
+ A quit or error annotation may be preceded by
+
+ ^Z^Zerror-begin
+
+ Any output between that and the quit or error annotation is the error
+message.
+
+ Warning messages are not yet annotated.
+
+
+File: gdb.info, Node: Invalidation, Next: Annotations for Running, Prev: Errors, Up: Annotations
+
+28.5 Invalidation Notices
+=========================
+
+The following annotations say that certain pieces of state may have
+changed.
+
+`^Z^Zframes-invalid'
+ The frames (for example, output from the `backtrace' command) may
+ have changed.
+
+`^Z^Zbreakpoints-invalid'
+ The breakpoints may have changed. For example, the user just
+ added or deleted a breakpoint.
+
+
+File: gdb.info, Node: Annotations for Running, Next: Source Annotations, Prev: Invalidation, Up: Annotations
+
+28.6 Running the Program
+========================
+
+When the program starts executing due to a GDB command such as `step'
+or `continue',
+
+ ^Z^Zstarting
+
+ is output. When the program stops,
+
+ ^Z^Zstopped
+
+ is output. Before the `stopped' annotation, a variety of
+annotations describe how the program stopped.
+
+`^Z^Zexited EXIT-STATUS'
+ The program exited, and EXIT-STATUS is the exit status (zero for
+ successful exit, otherwise nonzero).
+
+`^Z^Zsignalled'
+ The program exited with a signal. After the `^Z^Zsignalled', the
+ annotation continues:
+
+ INTRO-TEXT
+ ^Z^Zsignal-name
+ NAME
+ ^Z^Zsignal-name-end
+ MIDDLE-TEXT
+ ^Z^Zsignal-string
+ STRING
+ ^Z^Zsignal-string-end
+ END-TEXT
+
+ where NAME is the name of the signal, such as `SIGILL' or
+ `SIGSEGV', and STRING is the explanation of the signal, such as
+ `Illegal Instruction' or `Segmentation fault'. INTRO-TEXT,
+ MIDDLE-TEXT, and END-TEXT are for the user's benefit and have no
+ particular format.
+
+`^Z^Zsignal'
+ The syntax of this annotation is just like `signalled', but GDB is
+ just saying that the program received the signal, not that it was
+ terminated with it.
+
+`^Z^Zbreakpoint NUMBER'
+ The program hit breakpoint number NUMBER.
+
+`^Z^Zwatchpoint NUMBER'
+ The program hit watchpoint number NUMBER.
+
+
+File: gdb.info, Node: Source Annotations, Prev: Annotations for Running, Up: Annotations
+
+28.7 Displaying Source
+======================
+
+The following annotation is used instead of displaying source code:
+
+ ^Z^Zsource FILENAME:LINE:CHARACTER:MIDDLE:ADDR
+
+ where FILENAME is an absolute file name indicating which source
+file, LINE is the line number within that file (where 1 is the first
+line in the file), CHARACTER is the character position within the file
+(where 0 is the first character in the file) (for most debug formats
+this will necessarily point to the beginning of a line), MIDDLE is
+`middle' if ADDR is in the middle of the line, or `beg' if ADDR is at
+the beginning of the line, and ADDR is the address in the target
+program associated with the source which is being displayed. ADDR is
+in the form `0x' followed by one or more lowercase hex digits (note
+that this does not depend on the language).
+
+
+File: gdb.info, Node: JIT Interface, Next: GDB Bugs, Prev: Annotations, Up: Top
+
+29 JIT Compilation Interface
+****************************
+
+This chapter documents GDB's "just-in-time" (JIT) compilation
+interface. A JIT compiler is a program or library that generates native
+executable code at runtime and executes it, usually in order to achieve
+good performance while maintaining platform independence.
+
+ Programs that use JIT compilation are normally difficult to debug
+because portions of their code are generated at runtime, instead of
+being loaded from object files, which is where GDB normally finds the
+program's symbols and debug information. In order to debug programs
+that use JIT compilation, GDB has an interface that allows the program
+to register in-memory symbol files with GDB at runtime.
+
+ If you are using GDB to debug a program that uses this interface,
+then it should work transparently so long as you have not stripped the
+binary. If you are developing a JIT compiler, then the interface is
+documented in the rest of this chapter. At this time, the only known
+client of this interface is the LLVM JIT.
+
+ Broadly speaking, the JIT interface mirrors the dynamic loader
+interface. The JIT compiler communicates with GDB by writing data into
+a global variable and calling a fuction at a well-known symbol. When
+GDB attaches, it reads a linked list of symbol files from the global
+variable to find existing code, and puts a breakpoint in the function
+so that it can find out about additional code.
+
+* Menu:
+
+* Declarations:: Relevant C struct declarations
+* Registering Code:: Steps to register code
+* Unregistering Code:: Steps to unregister code
+* Custom Debug Info:: Emit debug information in a custom format
+
+
+File: gdb.info, Node: Declarations, Next: Registering Code, Up: JIT Interface
+
+29.1 JIT Declarations
+=====================
+
+These are the relevant struct declarations that a C program should
+include to implement the interface:
+
+ typedef enum
+ {
+ JIT_NOACTION = 0,
+ JIT_REGISTER_FN,
+ JIT_UNREGISTER_FN
+ } jit_actions_t;
+
+ struct jit_code_entry
+ {
+ struct jit_code_entry *next_entry;
+ struct jit_code_entry *prev_entry;
+ const char *symfile_addr;
+ uint64_t symfile_size;
+ };
+
+ struct jit_descriptor
+ {
+ uint32_t version;
+ /* This type should be jit_actions_t, but we use uint32_t
+ to be explicit about the bitwidth. */
+ uint32_t action_flag;
+ struct jit_code_entry *relevant_entry;
+ struct jit_code_entry *first_entry;
+ };
+
+ /* GDB puts a breakpoint in this function. */
+ void __attribute__((noinline)) __jit_debug_register_code() { };
+
+ /* Make sure to specify the version statically, because the
+ debugger may check the version before we can set it. */
+ struct jit_descriptor __jit_debug_descriptor = { 1, 0, 0, 0 };
+
+ If the JIT is multi-threaded, then it is important that the JIT
+synchronize any modifications to this global data properly, which can
+easily be done by putting a global mutex around modifications to these
+structures.
+
+
+File: gdb.info, Node: Registering Code, Next: Unregistering Code, Prev: Declarations, Up: JIT Interface
+
+29.2 Registering Code
+=====================
+
+To register code with GDB, the JIT should follow this protocol:
+
+ * Generate an object file in memory with symbols and other desired
+ debug information. The file must include the virtual addresses of
+ the sections.
+
+ * Create a code entry for the file, which gives the start and size
+ of the symbol file.
+
+ * Add it to the linked list in the JIT descriptor.
+
+ * Point the relevant_entry field of the descriptor at the entry.
+
+ * Set `action_flag' to `JIT_REGISTER' and call
+ `__jit_debug_register_code'.
+
+ When GDB is attached and the breakpoint fires, GDB uses the
+`relevant_entry' pointer so it doesn't have to walk the list looking for
+new code. However, the linked list must still be maintained in order
+to allow GDB to attach to a running process and still find the symbol
+files.
+
+
+File: gdb.info, Node: Unregistering Code, Next: Custom Debug Info, Prev: Registering Code, Up: JIT Interface
+
+29.3 Unregistering Code
+=======================
+
+If code is freed, then the JIT should use the following protocol:
+
+ * Remove the code entry corresponding to the code from the linked
+ list.
+
+ * Point the `relevant_entry' field of the descriptor at the code
+ entry.
+
+ * Set `action_flag' to `JIT_UNREGISTER' and call
+ `__jit_debug_register_code'.
+
+ If the JIT frees or recompiles code without unregistering it, then
+GDB and the JIT will leak the memory used for the associated symbol
+files.
+
+
+File: gdb.info, Node: Custom Debug Info, Prev: Unregistering Code, Up: JIT Interface
+
+29.4 Custom Debug Info
+======================
+
+Generating debug information in platform-native file formats (like ELF
+or COFF) may be an overkill for JIT compilers; especially if all the
+debug info is used for is displaying a meaningful backtrace. The issue
+can be resolved by having the JIT writers decide on a debug info format
+and also provide a reader that parses the debug info generated by the
+JIT compiler. This section gives a brief overview on writing such a
+parser. More specific details can be found in the source file
+`gdb/jit-reader.in', which is also installed as a header at
+`INCLUDEDIR/gdb/jit-reader.h' for easy inclusion.
+
+ The reader is implemented as a shared object (so this functionality
+is not available on platforms which don't allow loading shared objects
+at runtime). Two GDB commands, `jit-reader-load' and
+`jit-reader-unload' are provided, to be used to load and unload the
+readers from a preconfigured directory. Once loaded, the shared object
+is used the parse the debug information emitted by the JIT compiler.
+
+* Menu:
+
+* Using JIT Debug Info Readers:: How to use supplied readers correctly
+* Writing JIT Debug Info Readers:: Creating a debug-info reader
+
+
+File: gdb.info, Node: Using JIT Debug Info Readers, Next: Writing JIT Debug Info Readers, Up: Custom Debug Info
+
+29.4.1 Using JIT Debug Info Readers
+-----------------------------------
+
+Readers can be loaded and unloaded using the `jit-reader-load' and
+`jit-reader-unload' commands.
+
+`jit-reader-load READER-NAME'
+ Load the JIT reader named READER-NAME. On a UNIX system, this
+ will usually load `LIBDIR/gdb/READER-NAME', where LIBDIR is the
+ system library directory, usually `/usr/local/lib'. Only one
+ reader can be active at a time; trying to load a second reader
+ when one is already loaded will result in GDB reporting an error.
+ A new JIT reader can be loaded by first unloading the current one
+ using `jit-reader-load' and then invoking `jit-reader-load'.
+
+`jit-reader-unload'
+ Unload the currently loaded JIT reader.
+
+
+
+File: gdb.info, Node: Writing JIT Debug Info Readers, Prev: Using JIT Debug Info Readers, Up: Custom Debug Info
+
+29.4.2 Writing JIT Debug Info Readers
+-------------------------------------
+
+As mentioned, a reader is essentially a shared object conforming to a
+certain ABI. This ABI is described in `jit-reader.h'.
+
+ `jit-reader.h' defines the structures, macros and functions required
+to write a reader. It is installed (along with GDB), in
+`INCLUDEDIR/gdb' where INCLUDEDIR is the system include directory.
+
+ Readers need to be released under a GPL compatible license. A reader
+can be declared as released under such a license by placing the macro
+`GDB_DECLARE_GPL_COMPATIBLE_READER' in a source file.
+
+ The entry point for readers is the symbol `gdb_init_reader', which
+is expected to be a function with the prototype
+
+ extern struct gdb_reader_funcs *gdb_init_reader (void);
+
+ `struct gdb_reader_funcs' contains a set of pointers to callback
+functions. These functions are executed to read the debug info
+generated by the JIT compiler (`read'), to unwind stack frames
+(`unwind') and to create canonical frame IDs (`get_Frame_id'). It also
+has a callback that is called when the reader is being unloaded
+(`destroy'). The struct looks like this
+
+ struct gdb_reader_funcs
+ {
+ /* Must be set to GDB_READER_INTERFACE_VERSION. */
+ int reader_version;
+
+ /* For use by the reader. */
+ void *priv_data;
+
+ gdb_read_debug_info *read;
+ gdb_unwind_frame *unwind;
+ gdb_get_frame_id *get_frame_id;
+ gdb_destroy_reader *destroy;
+ };
+
+ The callbacks are provided with another set of callbacks by GDB to
+do their job. For `read', these callbacks are passed in a `struct
+gdb_symbol_callbacks' and for `unwind' and `get_frame_id', in a `struct
+gdb_unwind_callbacks'. `struct gdb_symbol_callbacks' has callbacks to
+create new object files and new symbol tables inside those object
+files. `struct gdb_unwind_callbacks' has callbacks to read registers
+off the current frame and to write out the values of the registers in
+the previous frame. Both have a callback (`target_read') to read bytes
+off the target's address space.
+
+
+File: gdb.info, Node: GDB Bugs, Next: Command Line Editing, Prev: JIT Interface, Up: Top
+
+30 Reporting Bugs in GDB
+************************
+
+Your bug reports play an essential role in making GDB reliable.
+
+ Reporting a bug may help you by bringing a solution to your problem,
+or it may not. But in any case the principal function of a bug report
+is to help the entire community by making the next version of GDB work
+better. Bug reports are your contribution to the maintenance of GDB.
+
+ In order for a bug report to serve its purpose, you must include the
+information that enables us to fix the bug.
+
+* Menu:
+
+* Bug Criteria:: Have you found a bug?
+* Bug Reporting:: How to report bugs
+
+
+File: gdb.info, Node: Bug Criteria, Next: Bug Reporting, Up: GDB Bugs
+
+30.1 Have You Found a Bug?
+==========================
+
+If you are not sure whether you have found a bug, here are some
+guidelines:
+
+ * If the debugger gets a fatal signal, for any input whatever, that
+ is a GDB bug. Reliable debuggers never crash.
+
+ * If GDB produces an error message for valid input, that is a bug.
+ (Note that if you're cross debugging, the problem may also be
+ somewhere in the connection to the target.)
+
+ * If GDB does not produce an error message for invalid input, that
+ is a bug. However, you should note that your idea of "invalid
+ input" might be our idea of "an extension" or "support for
+ traditional practice".
+
+ * If you are an experienced user of debugging tools, your suggestions
+ for improvement of GDB are welcome in any case.
+
+
+File: gdb.info, Node: Bug Reporting, Prev: Bug Criteria, Up: GDB Bugs
+
+30.2 How to Report Bugs
+=======================
+
+A number of companies and individuals offer support for GNU products.
+If you obtained GDB from a support organization, we recommend you
+contact that organization first.
+
+ You can find contact information for many support companies and
+individuals in the file `etc/SERVICE' in the GNU Emacs distribution.
+
+ In any event, we also recommend that you submit bug reports for GDB.
+The preferred method is to submit them directly using GDB's Bugs web
+page (http://www.gnu.org/software/gdb/bugs/). Alternatively, the
+e-mail gateway <bug-gdb@gnu.org> can be used.
+
+ *Do not send bug reports to `info-gdb', or to `help-gdb', or to any
+newsgroups.* Most users of GDB do not want to receive bug reports.
+Those that do have arranged to receive `bug-gdb'.
+
+ The mailing list `bug-gdb' has a newsgroup `gnu.gdb.bug' which
+serves as a repeater. The mailing list and the newsgroup carry exactly
+the same messages. Often people think of posting bug reports to the
+newsgroup instead of mailing them. This appears to work, but it has one
+problem which can be crucial: a newsgroup posting often lacks a mail
+path back to the sender. Thus, if we need to ask for more information,
+we may be unable to reach you. For this reason, it is better to send
+bug reports to the mailing list.
+
+ The fundamental principle of reporting bugs usefully is this:
+*report all the facts*. If you are not sure whether to state a fact or
+leave it out, state it!
+
+ Often people omit facts because they think they know what causes the
+problem and assume that some details do not matter. Thus, you might
+assume that the name of the variable you use in an example does not
+matter. Well, probably it does not, but one cannot be sure. Perhaps
+the bug is a stray memory reference which happens to fetch from the
+location where that name is stored in memory; perhaps, if the name were
+different, the contents of that location would fool the debugger into
+doing the right thing despite the bug. Play it safe and give a
+specific, complete example. That is the easiest thing for you to do,
+and the most helpful.
+
+ Keep in mind that the purpose of a bug report is to enable us to fix
+the bug. It may be that the bug has been reported previously, but
+neither you nor we can know that unless your bug report is complete and
+self-contained.
+
+ Sometimes people give a few sketchy facts and ask, "Does this ring a
+bell?" Those bug reports are useless, and we urge everyone to _refuse
+to respond to them_ except to chide the sender to report bugs properly.
+
+ To enable us to fix the bug, you should include all these things:
+
+ * The version of GDB. GDB announces it if you start with no
+ arguments; you can also print it at any time using `show version'.
+
+ Without this, we will not know whether there is any point in
+ looking for the bug in the current version of GDB.
+
+ * The type of machine you are using, and the operating system name
+ and version number.
+
+ * What compiler (and its version) was used to compile GDB--e.g.
+ "gcc-2.8.1".
+
+ * What compiler (and its version) was used to compile the program
+ you are debugging--e.g. "gcc-2.8.1", or "HP92453-01 A.10.32.03 HP
+ C Compiler". For GCC, you can say `gcc --version' to get this
+ information; for other compilers, see the documentation for those
+ compilers.
+
+ * The command arguments you gave the compiler to compile your
+ example and observe the bug. For example, did you use `-O'? To
+ guarantee you will not omit something important, list them all. A
+ copy of the Makefile (or the output from make) is sufficient.
+
+ If we were to try to guess the arguments, we would probably guess
+ wrong and then we might not encounter the bug.
+
+ * A complete input script, and all necessary source files, that will
+ reproduce the bug.
+
+ * A description of what behavior you observe that you believe is
+ incorrect. For example, "It gets a fatal signal."
+
+ Of course, if the bug is that GDB gets a fatal signal, then we
+ will certainly notice it. But if the bug is incorrect output, we
+ might not notice unless it is glaringly wrong. You might as well
+ not give us a chance to make a mistake.
+
+ Even if the problem you experience is a fatal signal, you should
+ still say so explicitly. Suppose something strange is going on,
+ such as, your copy of GDB is out of synch, or you have encountered
+ a bug in the C library on your system. (This has happened!) Your
+ copy might crash and ours would not. If you told us to expect a
+ crash, then when ours fails to crash, we would know that the bug
+ was not happening for us. If you had not told us to expect a
+ crash, then we would not be able to draw any conclusion from our
+ observations.
+
+ To collect all this information, you can use a session recording
+ program such as `script', which is available on many Unix systems.
+ Just run your GDB session inside `script' and then include the
+ `typescript' file with your bug report.
+
+ Another way to record a GDB session is to run GDB inside Emacs and
+ then save the entire buffer to a file.
+
+ * If you wish to suggest changes to the GDB source, send us context
+ diffs. If you even discuss something in the GDB source, refer to
+ it by context, not by line number.
+
+ The line numbers in our development sources will not match those
+ in your sources. Your line numbers would convey no useful
+ information to us.
+
+
+ Here are some things that are not necessary:
+
+ * A description of the envelope of the bug.
+
+ Often people who encounter a bug spend a lot of time investigating
+ which changes to the input file will make the bug go away and which
+ changes will not affect it.
+
+ This is often time consuming and not very useful, because the way
+ we will find the bug is by running a single example under the
+ debugger with breakpoints, not by pure deduction from a series of
+ examples. We recommend that you save your time for something else.
+
+ Of course, if you can find a simpler example to report _instead_
+ of the original one, that is a convenience for us. Errors in the
+ output will be easier to spot, running under the debugger will take
+ less time, and so on.
+
+ However, simplification is not vital; if you do not want to do
+ this, report the bug anyway and send us the entire test case you
+ used.
+
+ * A patch for the bug.
+
+ A patch for the bug does help us if it is a good one. But do not
+ omit the necessary information, such as the test case, on the
+ assumption that a patch is all we need. We might see problems
+ with your patch and decide to fix the problem another way, or we
+ might not understand it at all.
+
+ Sometimes with a program as complicated as GDB it is very hard to
+ construct an example that will make the program follow a certain
+ path through the code. If you do not send us the example, we will
+ not be able to construct one, so we will not be able to verify
+ that the bug is fixed.
+
+ And if we cannot understand what bug you are trying to fix, or why
+ your patch should be an improvement, we will not install it. A
+ test case will help us to understand.
+
+ * A guess about what the bug is or what it depends on.
+
+ Such guesses are usually wrong. Even we cannot guess right about
+ such things without first using the debugger to find the facts.
+
+
+File: gdb.info, Node: Command Line Editing, Next: Using History Interactively, Prev: GDB Bugs, Up: Top
+
+31 Command Line Editing
+***********************
+
+This chapter describes the basic features of the GNU command line
+editing interface.
+
+* Menu:
+
+* Introduction and Notation:: Notation used in this text.
+* Readline Interaction:: The minimum set of commands for editing a line.
+* Readline Init File:: Customizing Readline from a user's view.
+* Bindable Readline Commands:: A description of most of the Readline commands
+ available for binding
+* Readline vi Mode:: A short description of how to make Readline
+ behave like the vi editor.
+
+
+File: gdb.info, Node: Introduction and Notation, Next: Readline Interaction, Up: Command Line Editing
+
+31.1 Introduction to Line Editing
+=================================
+
+The following paragraphs describe the notation used to represent
+keystrokes.
+
+ The text `C-k' is read as `Control-K' and describes the character
+produced when the <k> key is pressed while the Control key is depressed.
+
+ The text `M-k' is read as `Meta-K' and describes the character
+produced when the Meta key (if you have one) is depressed, and the <k>
+key is pressed. The Meta key is labeled <ALT> on many keyboards. On
+keyboards with two keys labeled <ALT> (usually to either side of the
+space bar), the <ALT> on the left side is generally set to work as a
+Meta key. The <ALT> key on the right may also be configured to work as
+a Meta key or may be configured as some other modifier, such as a
+Compose key for typing accented characters.
+
+ If you do not have a Meta or <ALT> key, or another key working as a
+Meta key, the identical keystroke can be generated by typing <ESC>
+_first_, and then typing <k>. Either process is known as "metafying"
+the <k> key.
+
+ The text `M-C-k' is read as `Meta-Control-k' and describes the
+character produced by "metafying" `C-k'.
+
+ In addition, several keys have their own names. Specifically,
+<DEL>, <ESC>, <LFD>, <SPC>, <RET>, and <TAB> all stand for themselves
+when seen in this text, or in an init file (*note Readline Init File::).
+If your keyboard lacks a <LFD> key, typing <C-j> will produce the
+desired character. The <RET> key may be labeled <Return> or <Enter> on
+some keyboards.
+
+
+File: gdb.info, Node: Readline Interaction, Next: Readline Init File, Prev: Introduction and Notation, Up: Command Line Editing
+
+31.2 Readline Interaction
+=========================
+
+Often during an interactive session you type in a long line of text,
+only to notice that the first word on the line is misspelled. The
+Readline library gives you a set of commands for manipulating the text
+as you type it in, allowing you to just fix your typo, and not forcing
+you to retype the majority of the line. Using these editing commands,
+you move the cursor to the place that needs correction, and delete or
+insert the text of the corrections. Then, when you are satisfied with
+the line, you simply press <RET>. You do not have to be at the end of
+the line to press <RET>; the entire line is accepted regardless of the
+location of the cursor within the line.
+
+* Menu:
+
+* Readline Bare Essentials:: The least you need to know about Readline.
+* Readline Movement Commands:: Moving about the input line.
+* Readline Killing Commands:: How to delete text, and how to get it back!
+* Readline Arguments:: Giving numeric arguments to commands.
+* Searching:: Searching through previous lines.
+
+
+File: gdb.info, Node: Readline Bare Essentials, Next: Readline Movement Commands, Up: Readline Interaction
+
+31.2.1 Readline Bare Essentials
+-------------------------------
+
+In order to enter characters into the line, simply type them. The typed
+character appears where the cursor was, and then the cursor moves one
+space to the right. If you mistype a character, you can use your erase
+character to back up and delete the mistyped character.
+
+ Sometimes you may mistype a character, and not notice the error
+until you have typed several other characters. In that case, you can
+type `C-b' to move the cursor to the left, and then correct your
+mistake. Afterwards, you can move the cursor to the right with `C-f'.
+
+ When you add text in the middle of a line, you will notice that
+characters to the right of the cursor are `pushed over' to make room
+for the text that you have inserted. Likewise, when you delete text
+behind the cursor, characters to the right of the cursor are `pulled
+back' to fill in the blank space created by the removal of the text. A
+list of the bare essentials for editing the text of an input line
+follows.
+
+`C-b'
+ Move back one character.
+
+`C-f'
+ Move forward one character.
+
+<DEL> or <Backspace>
+ Delete the character to the left of the cursor.
+
+`C-d'
+ Delete the character underneath the cursor.
+
+Printing characters
+ Insert the character into the line at the cursor.
+
+`C-_' or `C-x C-u'
+ Undo the last editing command. You can undo all the way back to an
+ empty line.
+
+(Depending on your configuration, the <Backspace> key be set to delete
+the character to the left of the cursor and the <DEL> key set to delete
+the character underneath the cursor, like `C-d', rather than the
+character to the left of the cursor.)
+
+
+File: gdb.info, Node: Readline Movement Commands, Next: Readline Killing Commands, Prev: Readline Bare Essentials, Up: Readline Interaction
+
+31.2.2 Readline Movement Commands
+---------------------------------
+
+The above table describes the most basic keystrokes that you need in
+order to do editing of the input line. For your convenience, many
+other commands have been added in addition to `C-b', `C-f', `C-d', and
+<DEL>. Here are some commands for moving more rapidly about the line.
+
+`C-a'
+ Move to the start of the line.
+
+`C-e'
+ Move to the end of the line.
+
+`M-f'
+ Move forward a word, where a word is composed of letters and
+ digits.
+
+`M-b'
+ Move backward a word.
+
+`C-l'
+ Clear the screen, reprinting the current line at the top.
+
+ Notice how `C-f' moves forward a character, while `M-f' moves
+forward a word. It is a loose convention that control keystrokes
+operate on characters while meta keystrokes operate on words.
+
+
+File: gdb.info, Node: Readline Killing Commands, Next: Readline Arguments, Prev: Readline Movement Commands, Up: Readline Interaction
+
+31.2.3 Readline Killing Commands
+--------------------------------
+
+"Killing" text means to delete the text from the line, but to save it
+away for later use, usually by "yanking" (re-inserting) it back into
+the line. (`Cut' and `paste' are more recent jargon for `kill' and
+`yank'.)
+
+ If the description for a command says that it `kills' text, then you
+can be sure that you can get the text back in a different (or the same)
+place later.
+
+ When you use a kill command, the text is saved in a "kill-ring".
+Any number of consecutive kills save all of the killed text together, so
+that when you yank it back, you get it all. The kill ring is not line
+specific; the text that you killed on a previously typed line is
+available to be yanked back later, when you are typing another line.
+
+ Here is the list of commands for killing text.
+
+`C-k'
+ Kill the text from the current cursor position to the end of the
+ line.
+
+`M-d'
+ Kill from the cursor to the end of the current word, or, if between
+ words, to the end of the next word. Word boundaries are the same
+ as those used by `M-f'.
+
+`M-<DEL>'
+ Kill from the cursor the start of the current word, or, if between
+ words, to the start of the previous word. Word boundaries are the
+ same as those used by `M-b'.
+
+`C-w'
+ Kill from the cursor to the previous whitespace. This is
+ different than `M-<DEL>' because the word boundaries differ.
+
+
+ Here is how to "yank" the text back into the line. Yanking means to
+copy the most-recently-killed text from the kill buffer.
+
+`C-y'
+ Yank the most recently killed text back into the buffer at the
+ cursor.
+
+`M-y'
+ Rotate the kill-ring, and yank the new top. You can only do this
+ if the prior command is `C-y' or `M-y'.
+
+
+File: gdb.info, Node: Readline Arguments, Next: Searching, Prev: Readline Killing Commands, Up: Readline Interaction
+
+31.2.4 Readline Arguments
+-------------------------
+
+You can pass numeric arguments to Readline commands. Sometimes the
+argument acts as a repeat count, other times it is the sign of the
+argument that is significant. If you pass a negative argument to a
+command which normally acts in a forward direction, that command will
+act in a backward direction. For example, to kill text back to the
+start of the line, you might type `M-- C-k'.
+
+ The general way to pass numeric arguments to a command is to type
+meta digits before the command. If the first `digit' typed is a minus
+sign (`-'), then the sign of the argument will be negative. Once you
+have typed one meta digit to get the argument started, you can type the
+remainder of the digits, and then the command. For example, to give
+the `C-d' command an argument of 10, you could type `M-1 0 C-d', which
+will delete the next ten characters on the input line.
+
+
+File: gdb.info, Node: Searching, Prev: Readline Arguments, Up: Readline Interaction
+
+31.2.5 Searching for Commands in the History
+--------------------------------------------
+
+Readline provides commands for searching through the command history
+for lines containing a specified string. There are two search modes:
+"incremental" and "non-incremental".
+
+ Incremental searches begin before the user has finished typing the
+search string. As each character of the search string is typed,
+Readline displays the next entry from the history matching the string
+typed so far. An incremental search requires only as many characters
+as needed to find the desired history entry. To search backward in the
+history for a particular string, type `C-r'. Typing `C-s' searches
+forward through the history. The characters present in the value of
+the `isearch-terminators' variable are used to terminate an incremental
+search. If that variable has not been assigned a value, the <ESC> and
+`C-J' characters will terminate an incremental search. `C-g' will
+abort an incremental search and restore the original line. When the
+search is terminated, the history entry containing the search string
+becomes the current line.
+
+ To find other matching entries in the history list, type `C-r' or
+`C-s' as appropriate. This will search backward or forward in the
+history for the next entry matching the search string typed so far.
+Any other key sequence bound to a Readline command will terminate the
+search and execute that command. For instance, a <RET> will terminate
+the search and accept the line, thereby executing the command from the
+history list. A movement command will terminate the search, make the
+last line found the current line, and begin editing.
+
+ Readline remembers the last incremental search string. If two
+`C-r's are typed without any intervening characters defining a new
+search string, any remembered search string is used.
+
+ Non-incremental searches read the entire search string before
+starting to search for matching history lines. The search string may be
+typed by the user or be part of the contents of the current line.
+
+
+File: gdb.info, Node: Readline Init File, Next: Bindable Readline Commands, Prev: Readline Interaction, Up: Command Line Editing
+
+31.3 Readline Init File
+=======================
+
+Although the Readline library comes with a set of Emacs-like
+keybindings installed by default, it is possible to use a different set
+of keybindings. Any user can customize programs that use Readline by
+putting commands in an "inputrc" file, conventionally in his home
+directory. The name of this file is taken from the value of the
+environment variable `INPUTRC'. If that variable is unset, the default
+is `~/.inputrc'. If that file does not exist or cannot be read, the
+ultimate default is `/etc/inputrc'.
+
+ When a program which uses the Readline library starts up, the init
+file is read, and the key bindings are set.
+
+ In addition, the `C-x C-r' command re-reads this init file, thus
+incorporating any changes that you might have made to it.
+
+* Menu:
+
+* Readline Init File Syntax:: Syntax for the commands in the inputrc file.
+
+* Conditional Init Constructs:: Conditional key bindings in the inputrc file.
+
+* Sample Init File:: An example inputrc file.
+
+
+File: gdb.info, Node: Readline Init File Syntax, Next: Conditional Init Constructs, Up: Readline Init File
+
+31.3.1 Readline Init File Syntax
+--------------------------------
+
+There are only a few basic constructs allowed in the Readline init
+file. Blank lines are ignored. Lines beginning with a `#' are
+comments. Lines beginning with a `$' indicate conditional constructs
+(*note Conditional Init Constructs::). Other lines denote variable
+settings and key bindings.
+
+Variable Settings
+ You can modify the run-time behavior of Readline by altering the
+ values of variables in Readline using the `set' command within the
+ init file. The syntax is simple:
+
+ set VARIABLE VALUE
+
+ Here, for example, is how to change from the default Emacs-like
+ key binding to use `vi' line editing commands:
+
+ set editing-mode vi
+
+ Variable names and values, where appropriate, are recognized
+ without regard to case. Unrecognized variable names are ignored.
+
+ Boolean variables (those that can be set to on or off) are set to
+ on if the value is null or empty, ON (case-insensitive), or 1.
+ Any other value results in the variable being set to off.
+
+ A great deal of run-time behavior is changeable with the following
+ variables.
+
+ `bell-style'
+ Controls what happens when Readline wants to ring the
+ terminal bell. If set to `none', Readline never rings the
+ bell. If set to `visible', Readline uses a visible bell if
+ one is available. If set to `audible' (the default),
+ Readline attempts to ring the terminal's bell.
+
+ `bind-tty-special-chars'
+ If set to `on', Readline attempts to bind the control
+ characters treated specially by the kernel's terminal driver
+ to their Readline equivalents.
+
+ `comment-begin'
+ The string to insert at the beginning of the line when the
+ `insert-comment' command is executed. The default value is
+ `"#"'.
+
+ `completion-display-width'
+ The number of screen columns used to display possible matches
+ when performing completion. The value is ignored if it is
+ less than 0 or greater than the terminal screen width. A
+ value of 0 will cause matches to be displayed one per line.
+ The default value is -1.
+
+ `completion-ignore-case'
+ If set to `on', Readline performs filename matching and
+ completion in a case-insensitive fashion. The default value
+ is `off'.
+
+ `completion-map-case'
+ If set to `on', and COMPLETION-IGNORE-CASE is enabled,
+ Readline treats hyphens (`-') and underscores (`_') as
+ equivalent when performing case-insensitive filename matching
+ and completion.
+
+ `completion-prefix-display-length'
+ The length in characters of the common prefix of a list of
+ possible completions that is displayed without modification.
+ When set to a value greater than zero, common prefixes longer
+ than this value are replaced with an ellipsis when displaying
+ possible completions.
+
+ `completion-query-items'
+ The number of possible completions that determines when the
+ user is asked whether the list of possibilities should be
+ displayed. If the number of possible completions is greater
+ than this value, Readline will ask the user whether or not he
+ wishes to view them; otherwise, they are simply listed. This
+ variable must be set to an integer value greater than or
+ equal to 0. A negative value means Readline should never ask.
+ The default limit is `100'.
+
+ `convert-meta'
+ If set to `on', Readline will convert characters with the
+ eighth bit set to an ASCII key sequence by stripping the
+ eighth bit and prefixing an <ESC> character, converting them
+ to a meta-prefixed key sequence. The default value is `on'.
+
+ `disable-completion'
+ If set to `On', Readline will inhibit word completion.
+ Completion characters will be inserted into the line as if
+ they had been mapped to `self-insert'. The default is `off'.
+
+ `editing-mode'
+ The `editing-mode' variable controls which default set of key
+ bindings is used. By default, Readline starts up in Emacs
+ editing mode, where the keystrokes are most similar to Emacs.
+ This variable can be set to either `emacs' or `vi'.
+
+ `echo-control-characters'
+ When set to `on', on operating systems that indicate they
+ support it, readline echoes a character corresponding to a
+ signal generated from the keyboard. The default is `on'.
+
+ `enable-keypad'
+ When set to `on', Readline will try to enable the application
+ keypad when it is called. Some systems need this to enable
+ the arrow keys. The default is `off'.
+
+ `enable-meta-key'
+ When set to `on', Readline will try to enable any meta
+ modifier key the terminal claims to support when it is
+ called. On many terminals, the meta key is used to send
+ eight-bit characters. The default is `on'.
+
+ `expand-tilde'
+ If set to `on', tilde expansion is performed when Readline
+ attempts word completion. The default is `off'.
+
+ `history-preserve-point'
+ If set to `on', the history code attempts to place the point
+ (the current cursor position) at the same location on each
+ history line retrieved with `previous-history' or
+ `next-history'. The default is `off'.
+
+ `history-size'
+ Set the maximum number of history entries saved in the
+ history list. If set to zero, the number of entries in the
+ history list is not limited.
+
+ `horizontal-scroll-mode'
+ This variable can be set to either `on' or `off'. Setting it
+ to `on' means that the text of the lines being edited will
+ scroll horizontally on a single screen line when they are
+ longer than the width of the screen, instead of wrapping onto
+ a new screen line. By default, this variable is set to `off'.
+
+ `input-meta'
+ If set to `on', Readline will enable eight-bit input (it will
+ not clear the eighth bit in the characters it reads),
+ regardless of what the terminal claims it can support. The
+ default value is `off'. The name `meta-flag' is a synonym
+ for this variable.
+
+ `isearch-terminators'
+ The string of characters that should terminate an incremental
+ search without subsequently executing the character as a
+ command (*note Searching::). If this variable has not been
+ given a value, the characters <ESC> and `C-J' will terminate
+ an incremental search.
+
+ `keymap'
+ Sets Readline's idea of the current keymap for key binding
+ commands. Acceptable `keymap' names are `emacs',
+ `emacs-standard', `emacs-meta', `emacs-ctlx', `vi', `vi-move',
+ `vi-command', and `vi-insert'. `vi' is equivalent to
+ `vi-command'; `emacs' is equivalent to `emacs-standard'. The
+ default value is `emacs'. The value of the `editing-mode'
+ variable also affects the default keymap.
+
+ `mark-directories'
+ If set to `on', completed directory names have a slash
+ appended. The default is `on'.
+
+ `mark-modified-lines'
+ This variable, when set to `on', causes Readline to display an
+ asterisk (`*') at the start of history lines which have been
+ modified. This variable is `off' by default.
+
+ `mark-symlinked-directories'
+ If set to `on', completed names which are symbolic links to
+ directories have a slash appended (subject to the value of
+ `mark-directories'). The default is `off'.
+
+ `match-hidden-files'
+ This variable, when set to `on', causes Readline to match
+ files whose names begin with a `.' (hidden files) when
+ performing filename completion. If set to `off', the leading
+ `.' must be supplied by the user in the filename to be
+ completed. This variable is `on' by default.
+
+ `menu-complete-display-prefix'
+ If set to `on', menu completion displays the common prefix of
+ the list of possible completions (which may be empty) before
+ cycling through the list. The default is `off'.
+
+ `output-meta'
+ If set to `on', Readline will display characters with the
+ eighth bit set directly rather than as a meta-prefixed escape
+ sequence. The default is `off'.
+
+ `page-completions'
+ If set to `on', Readline uses an internal `more'-like pager
+ to display a screenful of possible completions at a time.
+ This variable is `on' by default.
+
+ `print-completions-horizontally'
+ If set to `on', Readline will display completions with matches
+ sorted horizontally in alphabetical order, rather than down
+ the screen. The default is `off'.
+
+ `revert-all-at-newline'
+ If set to `on', Readline will undo all changes to history
+ lines before returning when `accept-line' is executed. By
+ default, history lines may be modified and retain individual
+ undo lists across calls to `readline'. The default is `off'.
+
+ `show-all-if-ambiguous'
+ This alters the default behavior of the completion functions.
+ If set to `on', words which have more than one possible
+ completion cause the matches to be listed immediately instead
+ of ringing the bell. The default value is `off'.
+
+ `show-all-if-unmodified'
+ This alters the default behavior of the completion functions
+ in a fashion similar to SHOW-ALL-IF-AMBIGUOUS. If set to
+ `on', words which have more than one possible completion
+ without any possible partial completion (the possible
+ completions don't share a common prefix) cause the matches to
+ be listed immediately instead of ringing the bell. The
+ default value is `off'.
+
+ `skip-completed-text'
+ If set to `on', this alters the default completion behavior
+ when inserting a single match into the line. It's only
+ active when performing completion in the middle of a word.
+ If enabled, readline does not insert characters from the
+ completion that match characters after point in the word
+ being completed, so portions of the word following the cursor
+ are not duplicated. For instance, if this is enabled,
+ attempting completion when the cursor is after the `e' in
+ `Makefile' will result in `Makefile' rather than
+ `Makefilefile', assuming there is a single possible
+ completion. The default value is `off'.
+
+ `visible-stats'
+ If set to `on', a character denoting a file's type is
+ appended to the filename when listing possible completions.
+ The default is `off'.
+
+
+Key Bindings
+ The syntax for controlling key bindings in the init file is
+ simple. First you need to find the name of the command that you
+ want to change. The following sections contain tables of the
+ command name, the default keybinding, if any, and a short
+ description of what the command does.
+
+ Once you know the name of the command, simply place on a line in
+ the init file the name of the key you wish to bind the command to,
+ a colon, and then the name of the command. There can be no space
+ between the key name and the colon - that will be interpreted as
+ part of the key name. The name of the key can be expressed in
+ different ways, depending on what you find most comfortable.
+
+ In addition to command names, readline allows keys to be bound to
+ a string that is inserted when the key is pressed (a MACRO).
+
+ KEYNAME: FUNCTION-NAME or MACRO
+ KEYNAME is the name of a key spelled out in English. For
+ example:
+ Control-u: universal-argument
+ Meta-Rubout: backward-kill-word
+ Control-o: "> output"
+
+ In the above example, `C-u' is bound to the function
+ `universal-argument', `M-DEL' is bound to the function
+ `backward-kill-word', and `C-o' is bound to run the macro
+ expressed on the right hand side (that is, to insert the text
+ `> output' into the line).
+
+ A number of symbolic character names are recognized while
+ processing this key binding syntax: DEL, ESC, ESCAPE, LFD,
+ NEWLINE, RET, RETURN, RUBOUT, SPACE, SPC, and TAB.
+
+ "KEYSEQ": FUNCTION-NAME or MACRO
+ KEYSEQ differs from KEYNAME above in that strings denoting an
+ entire key sequence can be specified, by placing the key
+ sequence in double quotes. Some GNU Emacs style key escapes
+ can be used, as in the following example, but the special
+ character names are not recognized.
+
+ "\C-u": universal-argument
+ "\C-x\C-r": re-read-init-file
+ "\e[11~": "Function Key 1"
+
+ In the above example, `C-u' is again bound to the function
+ `universal-argument' (just as it was in the first example),
+ `C-x C-r' is bound to the function `re-read-init-file', and
+ `<ESC> <[> <1> <1> <~>' is bound to insert the text `Function
+ Key 1'.
+
+
+ The following GNU Emacs style escape sequences are available when
+ specifying key sequences:
+
+ `\C-'
+ control prefix
+
+ `\M-'
+ meta prefix
+
+ `\e'
+ an escape character
+
+ `\\'
+ backslash
+
+ `\"'
+ <">, a double quotation mark
+
+ `\''
+ <'>, a single quote or apostrophe
+
+ In addition to the GNU Emacs style escape sequences, a second set
+ of backslash escapes is available:
+
+ `\a'
+ alert (bell)
+
+ `\b'
+ backspace
+
+ `\d'
+ delete
+
+ `\f'
+ form feed
+
+ `\n'
+ newline
+
+ `\r'
+ carriage return
+
+ `\t'
+ horizontal tab
+
+ `\v'
+ vertical tab
+
+ `\NNN'
+ the eight-bit character whose value is the octal value NNN
+ (one to three digits)
+
+ `\xHH'
+ the eight-bit character whose value is the hexadecimal value
+ HH (one or two hex digits)
+
+ When entering the text of a macro, single or double quotes must be
+ used to indicate a macro definition. Unquoted text is assumed to
+ be a function name. In the macro body, the backslash escapes
+ described above are expanded. Backslash will quote any other
+ character in the macro text, including `"' and `''. For example,
+ the following binding will make `C-x \' insert a single `\' into
+ the line:
+ "\C-x\\": "\\"
+
+
+
+File: gdb.info, Node: Conditional Init Constructs, Next: Sample Init File, Prev: Readline Init File Syntax, Up: Readline Init File
+
+31.3.2 Conditional Init Constructs
+----------------------------------
+
+Readline implements a facility similar in spirit to the conditional
+compilation features of the C preprocessor which allows key bindings
+and variable settings to be performed as the result of tests. There
+are four parser directives used.
+
+`$if'
+ The `$if' construct allows bindings to be made based on the
+ editing mode, the terminal being used, or the application using
+ Readline. The text of the test extends to the end of the line; no
+ characters are required to isolate it.
+
+ `mode'
+ The `mode=' form of the `$if' directive is used to test
+ whether Readline is in `emacs' or `vi' mode. This may be
+ used in conjunction with the `set keymap' command, for
+ instance, to set bindings in the `emacs-standard' and
+ `emacs-ctlx' keymaps only if Readline is starting out in
+ `emacs' mode.
+
+ `term'
+ The `term=' form may be used to include terminal-specific key
+ bindings, perhaps to bind the key sequences output by the
+ terminal's function keys. The word on the right side of the
+ `=' is tested against both the full name of the terminal and
+ the portion of the terminal name before the first `-'. This
+ allows `sun' to match both `sun' and `sun-cmd', for instance.
+
+ `application'
+ The APPLICATION construct is used to include
+ application-specific settings. Each program using the
+ Readline library sets the APPLICATION NAME, and you can test
+ for a particular value. This could be used to bind key
+ sequences to functions useful for a specific program. For
+ instance, the following command adds a key sequence that
+ quotes the current or previous word in Bash:
+ $if Bash
+ # Quote the current or previous word
+ "\C-xq": "\eb\"\ef\""
+ $endif
+
+`$endif'
+ This command, as seen in the previous example, terminates an `$if'
+ command.
+
+`$else'
+ Commands in this branch of the `$if' directive are executed if the
+ test fails.
+
+`$include'
+ This directive takes a single filename as an argument and reads
+ commands and bindings from that file. For example, the following
+ directive reads from `/etc/inputrc':
+ $include /etc/inputrc
+
+
+File: gdb.info, Node: Sample Init File, Prev: Conditional Init Constructs, Up: Readline Init File
+
+31.3.3 Sample Init File
+-----------------------
+
+Here is an example of an INPUTRC file. This illustrates key binding,
+variable assignment, and conditional syntax.
+
+
+ # This file controls the behaviour of line input editing for
+ # programs that use the GNU Readline library. Existing
+ # programs include FTP, Bash, and GDB.
+ #
+ # You can re-read the inputrc file with C-x C-r.
+ # Lines beginning with '#' are comments.
+ #
+ # First, include any systemwide bindings and variable
+ # assignments from /etc/Inputrc
+ $include /etc/Inputrc
+
+ #
+ # Set various bindings for emacs mode.
+
+ set editing-mode emacs
+
+ $if mode=emacs
+
+ Meta-Control-h: backward-kill-word Text after the function name is ignored
+
+ #
+ # Arrow keys in keypad mode
+ #
+ #"\M-OD": backward-char
+ #"\M-OC": forward-char
+ #"\M-OA": previous-history
+ #"\M-OB": next-history
+ #
+ # Arrow keys in ANSI mode
+ #
+ "\M-[D": backward-char
+ "\M-[C": forward-char
+ "\M-[A": previous-history
+ "\M-[B": next-history
+ #
+ # Arrow keys in 8 bit keypad mode
+ #
+ #"\M-\C-OD": backward-char
+ #"\M-\C-OC": forward-char
+ #"\M-\C-OA": previous-history
+ #"\M-\C-OB": next-history
+ #
+ # Arrow keys in 8 bit ANSI mode
+ #
+ #"\M-\C-[D": backward-char
+ #"\M-\C-[C": forward-char
+ #"\M-\C-[A": previous-history
+ #"\M-\C-[B": next-history
+
+ C-q: quoted-insert
+
+ $endif
+
+ # An old-style binding. This happens to be the default.
+ TAB: complete
+
+ # Macros that are convenient for shell interaction
+ $if Bash
+ # edit the path
+ "\C-xp": "PATH=${PATH}\e\C-e\C-a\ef\C-f"
+ # prepare to type a quoted word --
+ # insert open and close double quotes
+ # and move to just after the open quote
+ "\C-x\"": "\"\"\C-b"
+ # insert a backslash (testing backslash escapes
+ # in sequences and macros)
+ "\C-x\\": "\\"
+ # Quote the current or previous word
+ "\C-xq": "\eb\"\ef\""
+ # Add a binding to refresh the line, which is unbound
+ "\C-xr": redraw-current-line
+ # Edit variable on current line.
+ "\M-\C-v": "\C-a\C-k$\C-y\M-\C-e\C-a\C-y="
+ $endif
+
+ # use a visible bell if one is available
+ set bell-style visible
+
+ # don't strip characters to 7 bits when reading
+ set input-meta on
+
+ # allow iso-latin1 characters to be inserted rather
+ # than converted to prefix-meta sequences
+ set convert-meta off
+
+ # display characters with the eighth bit set directly
+ # rather than as meta-prefixed characters
+ set output-meta on
+
+ # if there are more than 150 possible completions for
+ # a word, ask the user if he wants to see all of them
+ set completion-query-items 150
+
+ # For FTP
+ $if Ftp
+ "\C-xg": "get \M-?"
+ "\C-xt": "put \M-?"
+ "\M-.": yank-last-arg
+ $endif
+
+
+File: gdb.info, Node: Bindable Readline Commands, Next: Readline vi Mode, Prev: Readline Init File, Up: Command Line Editing
+
+31.4 Bindable Readline Commands
+===============================
+
+* Menu:
+
+* Commands For Moving:: Moving about the line.
+* Commands For History:: Getting at previous lines.
+* Commands For Text:: Commands for changing text.
+* Commands For Killing:: Commands for killing and yanking.
+* Numeric Arguments:: Specifying numeric arguments, repeat counts.
+* Commands For Completion:: Getting Readline to do the typing for you.
+* Keyboard Macros:: Saving and re-executing typed characters
+* Miscellaneous Commands:: Other miscellaneous commands.
+
+ This section describes Readline commands that may be bound to key
+sequences. Command names without an accompanying key sequence are
+unbound by default.
+
+ In the following descriptions, "point" refers to the current cursor
+position, and "mark" refers to a cursor position saved by the
+`set-mark' command. The text between the point and mark is referred to
+as the "region".
+
+
+File: gdb.info, Node: Commands For Moving, Next: Commands For History, Up: Bindable Readline Commands
+
+31.4.1 Commands For Moving
+--------------------------
+
+`beginning-of-line (C-a)'
+ Move to the start of the current line.
+
+`end-of-line (C-e)'
+ Move to the end of the line.
+
+`forward-char (C-f)'
+ Move forward a character.
+
+`backward-char (C-b)'
+ Move back a character.
+
+`forward-word (M-f)'
+ Move forward to the end of the next word. Words are composed of
+ letters and digits.
+
+`backward-word (M-b)'
+ Move back to the start of the current or previous word. Words are
+ composed of letters and digits.
+
+`clear-screen (C-l)'
+ Clear the screen and redraw the current line, leaving the current
+ line at the top of the screen.
+
+`redraw-current-line ()'
+ Refresh the current line. By default, this is unbound.
+
+
+
+File: gdb.info, Node: Commands For History, Next: Commands For Text, Prev: Commands For Moving, Up: Bindable Readline Commands
+
+31.4.2 Commands For Manipulating The History
+--------------------------------------------
+
+`accept-line (Newline or Return)'
+ Accept the line regardless of where the cursor is. If this line is
+ non-empty, it may be added to the history list for future recall
+ with `add_history()'. If this line is a modified history line,
+ the history line is restored to its original state.
+
+`previous-history (C-p)'
+ Move `back' through the history list, fetching the previous
+ command.
+
+`next-history (C-n)'
+ Move `forward' through the history list, fetching the next command.
+
+`beginning-of-history (M-<)'
+ Move to the first line in the history.
+
+`end-of-history (M->)'
+ Move to the end of the input history, i.e., the line currently
+ being entered.
+
+`reverse-search-history (C-r)'
+ Search backward starting at the current line and moving `up'
+ through the history as necessary. This is an incremental search.
+
+`forward-search-history (C-s)'
+ Search forward starting at the current line and moving `down'
+ through the the history as necessary. This is an incremental
+ search.
+
+`non-incremental-reverse-search-history (M-p)'
+ Search backward starting at the current line and moving `up'
+ through the history as necessary using a non-incremental search
+ for a string supplied by the user.
+
+`non-incremental-forward-search-history (M-n)'
+ Search forward starting at the current line and moving `down'
+ through the the history as necessary using a non-incremental search
+ for a string supplied by the user.
+
+`history-search-forward ()'
+ Search forward through the history for the string of characters
+ between the start of the current line and the point. This is a
+ non-incremental search. By default, this command is unbound.
+
+`history-search-backward ()'
+ Search backward through the history for the string of characters
+ between the start of the current line and the point. This is a
+ non-incremental search. By default, this command is unbound.
+
+`yank-nth-arg (M-C-y)'
+ Insert the first argument to the previous command (usually the
+ second word on the previous line) at point. With an argument N,
+ insert the Nth word from the previous command (the words in the
+ previous command begin with word 0). A negative argument inserts
+ the Nth word from the end of the previous command. Once the
+ argument N is computed, the argument is extracted as if the `!N'
+ history expansion had been specified.
+
+`yank-last-arg (M-. or M-_)'
+ Insert last argument to the previous command (the last word of the
+ previous history entry). With a numeric argument, behave exactly
+ like `yank-nth-arg'. Successive calls to `yank-last-arg' move
+ back through the history list, inserting the last word (or the
+ word specified by the argument to the first call) of each line in
+ turn. Any numeric argument supplied to these successive calls
+ determines the direction to move through the history. A negative
+ argument switches the direction through the history (back or
+ forward). The history expansion facilities are used to extract
+ the last argument, as if the `!$' history expansion had been
+ specified.
+
+
+
+File: gdb.info, Node: Commands For Text, Next: Commands For Killing, Prev: Commands For History, Up: Bindable Readline Commands
+
+31.4.3 Commands For Changing Text
+---------------------------------
+
+`delete-char (C-d)'
+ Delete the character at point. If point is at the beginning of
+ the line, there are no characters in the line, and the last
+ character typed was not bound to `delete-char', then return EOF.
+
+`backward-delete-char (Rubout)'
+ Delete the character behind the cursor. A numeric argument means
+ to kill the characters instead of deleting them.
+
+`forward-backward-delete-char ()'
+ Delete the character under the cursor, unless the cursor is at the
+ end of the line, in which case the character behind the cursor is
+ deleted. By default, this is not bound to a key.
+
+`quoted-insert (C-q or C-v)'
+ Add the next character typed to the line verbatim. This is how to
+ insert key sequences like `C-q', for example.
+
+`tab-insert (M-<TAB>)'
+ Insert a tab character.
+
+`self-insert (a, b, A, 1, !, ...)'
+ Insert yourself.
+
+`transpose-chars (C-t)'
+ Drag the character before the cursor forward over the character at
+ the cursor, moving the cursor forward as well. If the insertion
+ point is at the end of the line, then this transposes the last two
+ characters of the line. Negative arguments have no effect.
+
+`transpose-words (M-t)'
+ Drag the word before point past the word after point, moving point
+ past that word as well. If the insertion point is at the end of
+ the line, this transposes the last two words on the line.
+
+`upcase-word (M-u)'
+ Uppercase the current (or following) word. With a negative
+ argument, uppercase the previous word, but do not move the cursor.
+
+`downcase-word (M-l)'
+ Lowercase the current (or following) word. With a negative
+ argument, lowercase the previous word, but do not move the cursor.
+
+`capitalize-word (M-c)'
+ Capitalize the current (or following) word. With a negative
+ argument, capitalize the previous word, but do not move the cursor.
+
+`overwrite-mode ()'
+ Toggle overwrite mode. With an explicit positive numeric argument,
+ switches to overwrite mode. With an explicit non-positive numeric
+ argument, switches to insert mode. This command affects only
+ `emacs' mode; `vi' mode does overwrite differently. Each call to
+ `readline()' starts in insert mode.
+
+ In overwrite mode, characters bound to `self-insert' replace the
+ text at point rather than pushing the text to the right.
+ Characters bound to `backward-delete-char' replace the character
+ before point with a space.
+
+ By default, this command is unbound.
+
+
+
+File: gdb.info, Node: Commands For Killing, Next: Numeric Arguments, Prev: Commands For Text, Up: Bindable Readline Commands
+
+31.4.4 Killing And Yanking
+--------------------------
+
+`kill-line (C-k)'
+ Kill the text from point to the end of the line.
+
+`backward-kill-line (C-x Rubout)'
+ Kill backward to the beginning of the line.
+
+`unix-line-discard (C-u)'
+ Kill backward from the cursor to the beginning of the current line.
+
+`kill-whole-line ()'
+ Kill all characters on the current line, no matter where point is.
+ By default, this is unbound.
+
+`kill-word (M-d)'
+ Kill from point to the end of the current word, or if between
+ words, to the end of the next word. Word boundaries are the same
+ as `forward-word'.
+
+`backward-kill-word (M-<DEL>)'
+ Kill the word behind point. Word boundaries are the same as
+ `backward-word'.
+
+`unix-word-rubout (C-w)'
+ Kill the word behind point, using white space as a word boundary.
+ The killed text is saved on the kill-ring.
+
+`unix-filename-rubout ()'
+ Kill the word behind point, using white space and the slash
+ character as the word boundaries. The killed text is saved on the
+ kill-ring.
+
+`delete-horizontal-space ()'
+ Delete all spaces and tabs around point. By default, this is
+ unbound.
+
+`kill-region ()'
+ Kill the text in the current region. By default, this command is
+ unbound.
+
+`copy-region-as-kill ()'
+ Copy the text in the region to the kill buffer, so it can be yanked
+ right away. By default, this command is unbound.
+
+`copy-backward-word ()'
+ Copy the word before point to the kill buffer. The word
+ boundaries are the same as `backward-word'. By default, this
+ command is unbound.
+
+`copy-forward-word ()'
+ Copy the word following point to the kill buffer. The word
+ boundaries are the same as `forward-word'. By default, this
+ command is unbound.
+
+`yank (C-y)'
+ Yank the top of the kill ring into the buffer at point.
+
+`yank-pop (M-y)'
+ Rotate the kill-ring, and yank the new top. You can only do this
+ if the prior command is `yank' or `yank-pop'.
+
+
+File: gdb.info, Node: Numeric Arguments, Next: Commands For Completion, Prev: Commands For Killing, Up: Bindable Readline Commands
+
+31.4.5 Specifying Numeric Arguments
+-----------------------------------
+
+`digit-argument (M-0, M-1, ... M--)'
+ Add this digit to the argument already accumulating, or start a new
+ argument. `M--' starts a negative argument.
+
+`universal-argument ()'
+ This is another way to specify an argument. If this command is
+ followed by one or more digits, optionally with a leading minus
+ sign, those digits define the argument. If the command is
+ followed by digits, executing `universal-argument' again ends the
+ numeric argument, but is otherwise ignored. As a special case, if
+ this command is immediately followed by a character that is
+ neither a digit or minus sign, the argument count for the next
+ command is multiplied by four. The argument count is initially
+ one, so executing this function the first time makes the argument
+ count four, a second time makes the argument count sixteen, and so
+ on. By default, this is not bound to a key.
+
+
+File: gdb.info, Node: Commands For Completion, Next: Keyboard Macros, Prev: Numeric Arguments, Up: Bindable Readline Commands
+
+31.4.6 Letting Readline Type For You
+------------------------------------
+
+`complete (<TAB>)'
+ Attempt to perform completion on the text before point. The
+ actual completion performed is application-specific. The default
+ is filename completion.
+
+`possible-completions (M-?)'
+ List the possible completions of the text before point. When
+ displaying completions, Readline sets the number of columns used
+ for display to the value of `completion-display-width', the value
+ of the environment variable `COLUMNS', or the screen width, in
+ that order.
+
+`insert-completions (M-*)'
+ Insert all completions of the text before point that would have
+ been generated by `possible-completions'.
+
+`menu-complete ()'
+ Similar to `complete', but replaces the word to be completed with
+ a single match from the list of possible completions. Repeated
+ execution of `menu-complete' steps through the list of possible
+ completions, inserting each match in turn. At the end of the list
+ of completions, the bell is rung (subject to the setting of
+ `bell-style') and the original text is restored. An argument of N
+ moves N positions forward in the list of matches; a negative
+ argument may be used to move backward through the list. This
+ command is intended to be bound to <TAB>, but is unbound by
+ default.
+
+`menu-complete-backward ()'
+ Identical to `menu-complete', but moves backward through the list
+ of possible completions, as if `menu-complete' had been given a
+ negative argument.
+
+`delete-char-or-list ()'
+ Deletes the character under the cursor if not at the beginning or
+ end of the line (like `delete-char'). If at the end of the line,
+ behaves identically to `possible-completions'. This command is
+ unbound by default.
+
+
+
+File: gdb.info, Node: Keyboard Macros, Next: Miscellaneous Commands, Prev: Commands For Completion, Up: Bindable Readline Commands
+
+31.4.7 Keyboard Macros
+----------------------
+
+`start-kbd-macro (C-x ()'
+ Begin saving the characters typed into the current keyboard macro.
+
+`end-kbd-macro (C-x ))'
+ Stop saving the characters typed into the current keyboard macro
+ and save the definition.
+
+`call-last-kbd-macro (C-x e)'
+ Re-execute the last keyboard macro defined, by making the
+ characters in the macro appear as if typed at the keyboard.
+
+
+
+File: gdb.info, Node: Miscellaneous Commands, Prev: Keyboard Macros, Up: Bindable Readline Commands
+
+31.4.8 Some Miscellaneous Commands
+----------------------------------
+
+`re-read-init-file (C-x C-r)'
+ Read in the contents of the INPUTRC file, and incorporate any
+ bindings or variable assignments found there.
+
+`abort (C-g)'
+ Abort the current editing command and ring the terminal's bell
+ (subject to the setting of `bell-style').
+
+`do-uppercase-version (M-a, M-b, M-X, ...)'
+ If the metafied character X is lowercase, run the command that is
+ bound to the corresponding uppercase character.
+
+`prefix-meta (<ESC>)'
+ Metafy the next character typed. This is for keyboards without a
+ meta key. Typing `<ESC> f' is equivalent to typing `M-f'.
+
+`undo (C-_ or C-x C-u)'
+ Incremental undo, separately remembered for each line.
+
+`revert-line (M-r)'
+ Undo all changes made to this line. This is like executing the
+ `undo' command enough times to get back to the beginning.
+
+`tilde-expand (M-~)'
+ Perform tilde expansion on the current word.
+
+`set-mark (C-@)'
+ Set the mark to the point. If a numeric argument is supplied, the
+ mark is set to that position.
+
+`exchange-point-and-mark (C-x C-x)'
+ Swap the point with the mark. The current cursor position is set
+ to the saved position, and the old cursor position is saved as the
+ mark.
+
+`character-search (C-])'
+ A character is read and point is moved to the next occurrence of
+ that character. A negative count searches for previous
+ occurrences.
+
+`character-search-backward (M-C-])'
+ A character is read and point is moved to the previous occurrence
+ of that character. A negative count searches for subsequent
+ occurrences.
+
+`skip-csi-sequence ()'
+ Read enough characters to consume a multi-key sequence such as
+ those defined for keys like Home and End. Such sequences begin
+ with a Control Sequence Indicator (CSI), usually ESC-[. If this
+ sequence is bound to "\e[", keys producing such sequences will
+ have no effect unless explicitly bound to a readline command,
+ instead of inserting stray characters into the editing buffer.
+ This is unbound by default, but usually bound to ESC-[.
+
+`insert-comment (M-#)'
+ Without a numeric argument, the value of the `comment-begin'
+ variable is inserted at the beginning of the current line. If a
+ numeric argument is supplied, this command acts as a toggle: if
+ the characters at the beginning of the line do not match the value
+ of `comment-begin', the value is inserted, otherwise the
+ characters in `comment-begin' are deleted from the beginning of
+ the line. In either case, the line is accepted as if a newline
+ had been typed.
+
+`dump-functions ()'
+ Print all of the functions and their key bindings to the Readline
+ output stream. If a numeric argument is supplied, the output is
+ formatted in such a way that it can be made part of an INPUTRC
+ file. This command is unbound by default.
+
+`dump-variables ()'
+ Print all of the settable variables and their values to the
+ Readline output stream. If a numeric argument is supplied, the
+ output is formatted in such a way that it can be made part of an
+ INPUTRC file. This command is unbound by default.
+
+`dump-macros ()'
+ Print all of the Readline key sequences bound to macros and the
+ strings they output. If a numeric argument is supplied, the
+ output is formatted in such a way that it can be made part of an
+ INPUTRC file. This command is unbound by default.
+
+`emacs-editing-mode (C-e)'
+ When in `vi' command mode, this causes a switch to `emacs' editing
+ mode.
+
+`vi-editing-mode (M-C-j)'
+ When in `emacs' editing mode, this causes a switch to `vi' editing
+ mode.
+
+
+
+File: gdb.info, Node: Readline vi Mode, Prev: Bindable Readline Commands, Up: Command Line Editing
+
+31.5 Readline vi Mode
+=====================
+
+While the Readline library does not have a full set of `vi' editing
+functions, it does contain enough to allow simple editing of the line.
+The Readline `vi' mode behaves as specified in the POSIX standard.
+
+ In order to switch interactively between `emacs' and `vi' editing
+modes, use the command `M-C-j' (bound to emacs-editing-mode when in
+`vi' mode and to vi-editing-mode in `emacs' mode). The Readline
+default is `emacs' mode.
+
+ When you enter a line in `vi' mode, you are already placed in
+`insertion' mode, as if you had typed an `i'. Pressing <ESC> switches
+you into `command' mode, where you can edit the text of the line with
+the standard `vi' movement keys, move to previous history lines with
+`k' and subsequent lines with `j', and so forth.
+
+
+File: gdb.info, Node: Using History Interactively, Next: In Memoriam, Prev: Command Line Editing, Up: Top
+
+32 Using History Interactively
+******************************
+
+This chapter describes how to use the GNU History Library interactively,
+from a user's standpoint. It should be considered a user's guide. For
+information on using the GNU History Library in your own programs,
+*note Programming with GNU History: (history)Programming with GNU
+History.
+
+* Menu:
+
+* History Interaction:: What it feels like using History as a user.
+
+
+File: gdb.info, Node: History Interaction, Up: Using History Interactively
+
+32.1 History Expansion
+======================
+
+The History library provides a history expansion feature that is similar
+to the history expansion provided by `csh'. This section describes the
+syntax used to manipulate the history information.
+
+ History expansions introduce words from the history list into the
+input stream, making it easy to repeat commands, insert the arguments
+to a previous command into the current input line, or fix errors in
+previous commands quickly.
+
+ History expansion takes place in two parts. The first is to
+determine which line from the history list should be used during
+substitution. The second is to select portions of that line for
+inclusion into the current one. The line selected from the history is
+called the "event", and the portions of that line that are acted upon
+are called "words". Various "modifiers" are available to manipulate
+the selected words. The line is broken into words in the same fashion
+that Bash does, so that several words surrounded by quotes are
+considered one word. History expansions are introduced by the
+appearance of the history expansion character, which is `!' by default.
+
+* Menu:
+
+* Event Designators:: How to specify which history line to use.
+* Word Designators:: Specifying which words are of interest.
+* Modifiers:: Modifying the results of substitution.
+
+
+File: gdb.info, Node: Event Designators, Next: Word Designators, Up: History Interaction
+
+32.1.1 Event Designators
+------------------------
+
+An event designator is a reference to a command line entry in the
+history list. Unless the reference is absolute, events are relative to
+the current position in the history list.
+
+`!'
+ Start a history substitution, except when followed by a space, tab,
+ the end of the line, or `='.
+
+`!N'
+ Refer to command line N.
+
+`!-N'
+ Refer to the command N lines back.
+
+`!!'
+ Refer to the previous command. This is a synonym for `!-1'.
+
+`!STRING'
+ Refer to the most recent command preceding the current position in
+ the history list starting with STRING.
+
+`!?STRING[?]'
+ Refer to the most recent command preceding the current position in
+ the history list containing STRING. The trailing `?' may be
+ omitted if the STRING is followed immediately by a newline.
+
+`^STRING1^STRING2^'
+ Quick Substitution. Repeat the last command, replacing STRING1
+ with STRING2. Equivalent to `!!:s/STRING1/STRING2/'.
+
+`!#'
+ The entire command line typed so far.
+
+
+
+File: gdb.info, Node: Word Designators, Next: Modifiers, Prev: Event Designators, Up: History Interaction
+
+32.1.2 Word Designators
+-----------------------
+
+Word designators are used to select desired words from the event. A
+`:' separates the event specification from the word designator. It may
+be omitted if the word designator begins with a `^', `$', `*', `-', or
+`%'. Words are numbered from the beginning of the line, with the first
+word being denoted by 0 (zero). Words are inserted into the current
+line separated by single spaces.
+
+ For example,
+
+`!!'
+ designates the preceding command. When you type this, the
+ preceding command is repeated in toto.
+
+`!!:$'
+ designates the last argument of the preceding command. This may be
+ shortened to `!$'.
+
+`!fi:2'
+ designates the second argument of the most recent command starting
+ with the letters `fi'.
+
+ Here are the word designators:
+
+`0 (zero)'
+ The `0'th word. For many applications, this is the command word.
+
+`N'
+ The Nth word.
+
+`^'
+ The first argument; that is, word 1.
+
+`$'
+ The last argument.
+
+`%'
+ The word matched by the most recent `?STRING?' search.
+
+`X-Y'
+ A range of words; `-Y' abbreviates `0-Y'.
+
+`*'
+ All of the words, except the `0'th. This is a synonym for `1-$'.
+ It is not an error to use `*' if there is just one word in the
+ event; the empty string is returned in that case.
+
+`X*'
+ Abbreviates `X-$'
+
+`X-'
+ Abbreviates `X-$' like `X*', but omits the last word.
+
+
+ If a word designator is supplied without an event specification, the
+previous command is used as the event.
+
+
+File: gdb.info, Node: Modifiers, Prev: Word Designators, Up: History Interaction
+
+32.1.3 Modifiers
+----------------
+
+After the optional word designator, you can add a sequence of one or
+more of the following modifiers, each preceded by a `:'.
+
+`h'
+ Remove a trailing pathname component, leaving only the head.
+
+`t'
+ Remove all leading pathname components, leaving the tail.
+
+`r'
+ Remove a trailing suffix of the form `.SUFFIX', leaving the
+ basename.
+
+`e'
+ Remove all but the trailing suffix.
+
+`p'
+ Print the new command but do not execute it.
+
+`s/OLD/NEW/'
+ Substitute NEW for the first occurrence of OLD in the event line.
+ Any delimiter may be used in place of `/'. The delimiter may be
+ quoted in OLD and NEW with a single backslash. If `&' appears in
+ NEW, it is replaced by OLD. A single backslash will quote the
+ `&'. The final delimiter is optional if it is the last character
+ on the input line.
+
+`&'
+ Repeat the previous substitution.
+
+`g'
+`a'
+ Cause changes to be applied over the entire event line. Used in
+ conjunction with `s', as in `gs/OLD/NEW/', or with `&'.
+
+`G'
+ Apply the following `s' modifier once to each word in the event.
+
+
+
+File: gdb.info, Node: In Memoriam, Next: Formatting Documentation, Prev: Using History Interactively, Up: Top
+
+Appendix A In Memoriam
+**********************
+
+The GDB project mourns the loss of the following long-time contributors:
+
+`Fred Fish'
+ Fred was a long-standing contributor to GDB (1991-2006), and to
+ Free Software in general. Outside of GDB, he was known in the
+ Amiga world for his series of Fish Disks, and the GeekGadget
+ project.
+
+`Michael Snyder'
+ Michael was one of the Global Maintainers of the GDB project, with
+ contributions recorded as early as 1996, until 2011. In addition
+ to his day to day participation, he was a large driving force
+ behind adding Reverse Debugging to GDB.
+
+ Beyond their technical contributions to the project, they were also
+enjoyable members of the Free Software Community. We will miss them.
+
+
+File: gdb.info, Node: Formatting Documentation, Next: Installing GDB, Prev: In Memoriam, Up: Top
+
+Appendix B Formatting Documentation
+***********************************
+
+The GDB 4 release includes an already-formatted reference card, ready
+for printing with PostScript or Ghostscript, in the `gdb' subdirectory
+of the main source directory(1). If you can use PostScript or
+Ghostscript with your printer, you can print the reference card
+immediately with `refcard.ps'.
+
+ The release also includes the source for the reference card. You
+can format it, using TeX, by typing:
+
+ make refcard.dvi
+
+ The GDB reference card is designed to print in "landscape" mode on
+US "letter" size paper; that is, on a sheet 11 inches wide by 8.5 inches
+high. You will need to specify this form of printing as an option to
+your DVI output program.
+
+ All the documentation for GDB comes as part of the machine-readable
+distribution. The documentation is written in Texinfo format, which is
+a documentation system that uses a single source file to produce both
+on-line information and a printed manual. You can use one of the Info
+formatting commands to create the on-line version of the documentation
+and TeX (or `texi2roff') to typeset the printed version.
+
+ GDB includes an already formatted copy of the on-line Info version
+of this manual in the `gdb' subdirectory. The main Info file is
+`gdb-7.4.1/gdb/gdb.info', and it refers to subordinate files matching
+`gdb.info*' in the same directory. If necessary, you can print out
+these files, or read them with any editor; but they are easier to read
+using the `info' subsystem in GNU Emacs or the standalone `info'
+program, available as part of the GNU Texinfo distribution.
+
+ If you want to format these Info files yourself, you need one of the
+Info formatting programs, such as `texinfo-format-buffer' or `makeinfo'.
+
+ If you have `makeinfo' installed, and are in the top level GDB
+source directory (`gdb-7.4.1', in the case of version 7.4.1), you can
+make the Info file by typing:
+
+ cd gdb
+ make gdb.info
+
+ If you want to typeset and print copies of this manual, you need TeX,
+a program to print its DVI output files, and `texinfo.tex', the Texinfo
+definitions file.
+
+ TeX is a typesetting program; it does not print files directly, but
+produces output files called DVI files. To print a typeset document,
+you need a program to print DVI files. If your system has TeX
+installed, chances are it has such a program. The precise command to
+use depends on your system; `lpr -d' is common; another (for PostScript
+devices) is `dvips'. The DVI print command may require a file name
+without any extension or a `.dvi' extension.
+
+ TeX also requires a macro definitions file called `texinfo.tex'.
+This file tells TeX how to typeset a document written in Texinfo
+format. On its own, TeX cannot either read or typeset a Texinfo file.
+`texinfo.tex' is distributed with GDB and is located in the
+`gdb-VERSION-NUMBER/texinfo' directory.
+
+ If you have TeX and a DVI printer program installed, you can typeset
+and print this manual. First switch to the `gdb' subdirectory of the
+main source directory (for example, to `gdb-7.4.1/gdb') and type:
+
+ make gdb.dvi
+
+ Then give `gdb.dvi' to your DVI printing program.
+
+ ---------- Footnotes ----------
+
+ (1) In `gdb-7.4.1/gdb/refcard.ps' of the version 7.4.1 release.
+
+
+File: gdb.info, Node: Installing GDB, Next: Maintenance Commands, Prev: Formatting Documentation, Up: Top
+
+Appendix C Installing GDB
+*************************
+
+* Menu:
+
+* Requirements:: Requirements for building GDB
+* Running Configure:: Invoking the GDB `configure' script
+* Separate Objdir:: Compiling GDB in another directory
+* Config Names:: Specifying names for hosts and targets
+* Configure Options:: Summary of options for configure
+* System-wide configuration:: Having a system-wide init file
+
+
+File: gdb.info, Node: Requirements, Next: Running Configure, Up: Installing GDB
+
+C.1 Requirements for Building GDB
+=================================
+
+Building GDB requires various tools and packages to be available.
+Other packages will be used only if they are found.
+
+Tools/Packages Necessary for Building GDB
+=========================================
+
+ISO C90 compiler
+ GDB is written in ISO C90. It should be buildable with any
+ working C90 compiler, e.g. GCC.
+
+
+Tools/Packages Optional for Building GDB
+========================================
+
+Expat
+ GDB can use the Expat XML parsing library. This library may be
+ included with your operating system distribution; if it is not, you
+ can get the latest version from `http://expat.sourceforge.net'.
+ The `configure' script will search for this library in several
+ standard locations; if it is installed in an unusual path, you can
+ use the `--with-libexpat-prefix' option to specify its location.
+
+ Expat is used for:
+
+ * Remote protocol memory maps (*note Memory Map Format::)
+
+ * Target descriptions (*note Target Descriptions::)
+
+ * Remote shared library lists (*Note Library List Format::, or
+ alternatively *note Library List Format for SVR4 Targets::)
+
+ * MS-Windows shared libraries (*note Shared Libraries::)
+
+ * Traceframe info (*note Traceframe Info Format::)
+
+zlib
+ GDB will use the `zlib' library, if available, to read compressed
+ debug sections. Some linkers, such as GNU gold, are capable of
+ producing binaries with compressed debug sections. If GDB is
+ compiled with `zlib', it will be able to read the debug
+ information in such binaries.
+
+ The `zlib' library is likely included with your operating system
+ distribution; if it is not, you can get the latest version from
+ `http://zlib.net'.
+
+iconv
+ GDB's features related to character sets (*note Character Sets::)
+ require a functioning `iconv' implementation. If you are on a GNU
+ system, then this is provided by the GNU C Library. Some other
+ systems also provide a working `iconv'.
+
+ If GDB is using the `iconv' program which is installed in a
+ non-standard place, you will need to tell GDB where to find it.
+ This is done with `--with-iconv-bin' which specifies the directory
+ that contains the `iconv' program.
+
+ On systems without `iconv', you can install GNU Libiconv. If you
+ have previously installed Libiconv, you can use the
+ `--with-libiconv-prefix' option to configure.
+
+ GDB's top-level `configure' and `Makefile' will arrange to build
+ Libiconv if a directory named `libiconv' appears in the top-most
+ source directory. If Libiconv is built this way, and if the
+ operating system does not provide a suitable `iconv'
+ implementation, then the just-built library will automatically be
+ used by GDB. One easy way to set this up is to download GNU
+ Libiconv, unpack it, and then rename the directory holding the
+ Libiconv source code to `libiconv'.
+
+
+File: gdb.info, Node: Running Configure, Next: Separate Objdir, Prev: Requirements, Up: Installing GDB
+
+C.2 Invoking the GDB `configure' Script
+=======================================
+
+GDB comes with a `configure' script that automates the process of
+preparing GDB for installation; you can then use `make' to build the
+`gdb' program.
+
+ The GDB distribution includes all the source code you need for GDB
+in a single directory, whose name is usually composed by appending the
+version number to `gdb'.
+
+ For example, the GDB version 7.4.1 distribution is in the
+`gdb-7.4.1' directory. That directory contains:
+
+`gdb-7.4.1/configure (and supporting files)'
+ script for configuring GDB and all its supporting libraries
+
+`gdb-7.4.1/gdb'
+ the source specific to GDB itself
+
+`gdb-7.4.1/bfd'
+ source for the Binary File Descriptor library
+
+`gdb-7.4.1/include'
+ GNU include files
+
+`gdb-7.4.1/libiberty'
+ source for the `-liberty' free software library
+
+`gdb-7.4.1/opcodes'
+ source for the library of opcode tables and disassemblers
+
+`gdb-7.4.1/readline'
+ source for the GNU command-line interface
+
+`gdb-7.4.1/glob'
+ source for the GNU filename pattern-matching subroutine
+
+`gdb-7.4.1/mmalloc'
+ source for the GNU memory-mapped malloc package
+
+ The simplest way to configure and build GDB is to run `configure'
+from the `gdb-VERSION-NUMBER' source directory, which in this example
+is the `gdb-7.4.1' directory.
+
+ First switch to the `gdb-VERSION-NUMBER' source directory if you are
+not already in it; then run `configure'. Pass the identifier for the
+platform on which GDB will run as an argument.
+
+ For example:
+
+ cd gdb-7.4.1
+ ./configure HOST
+ make
+
+where HOST is an identifier such as `sun4' or `decstation', that
+identifies the platform where GDB will run. (You can often leave off
+HOST; `configure' tries to guess the correct value by examining your
+system.)
+
+ Running `configure HOST' and then running `make' builds the `bfd',
+`readline', `mmalloc', and `libiberty' libraries, then `gdb' itself.
+The configured source files, and the binaries, are left in the
+corresponding source directories.
+
+ `configure' is a Bourne-shell (`/bin/sh') script; if your system
+does not recognize this automatically when you run a different shell,
+you may need to run `sh' on it explicitly:
+
+ sh configure HOST
+
+ If you run `configure' from a directory that contains source
+directories for multiple libraries or programs, such as the `gdb-7.4.1'
+source directory for version 7.4.1, `configure' creates configuration
+files for every directory level underneath (unless you tell it not to,
+with the `--norecursion' option).
+
+ You should run the `configure' script from the top directory in the
+source tree, the `gdb-VERSION-NUMBER' directory. If you run
+`configure' from one of the subdirectories, you will configure only
+that subdirectory. That is usually not what you want. In particular,
+if you run the first `configure' from the `gdb' subdirectory of the
+`gdb-VERSION-NUMBER' directory, you will omit the configuration of
+`bfd', `readline', and other sibling directories of the `gdb'
+subdirectory. This leads to build errors about missing include files
+such as `bfd/bfd.h'.
+
+ You can install `gdb' anywhere; it has no hardwired paths. However,
+you should make sure that the shell on your path (named by the `SHELL'
+environment variable) is publicly readable. Remember that GDB uses the
+shell to start your program--some systems refuse to let GDB debug child
+processes whose programs are not readable.
+
+
+File: gdb.info, Node: Separate Objdir, Next: Config Names, Prev: Running Configure, Up: Installing GDB
+
+C.3 Compiling GDB in Another Directory
+======================================
+
+If you want to run GDB versions for several host or target machines,
+you need a different `gdb' compiled for each combination of host and
+target. `configure' is designed to make this easy by allowing you to
+generate each configuration in a separate subdirectory, rather than in
+the source directory. If your `make' program handles the `VPATH'
+feature (GNU `make' does), running `make' in each of these directories
+builds the `gdb' program specified there.
+
+ To build `gdb' in a separate directory, run `configure' with the
+`--srcdir' option to specify where to find the source. (You also need
+to specify a path to find `configure' itself from your working
+directory. If the path to `configure' would be the same as the
+argument to `--srcdir', you can leave out the `--srcdir' option; it is
+assumed.)
+
+ For example, with version 7.4.1, you can build GDB in a separate
+directory for a Sun 4 like this:
+
+ cd gdb-7.4.1
+ mkdir ../gdb-sun4
+ cd ../gdb-sun4
+ ../gdb-7.4.1/configure sun4
+ make
+
+ When `configure' builds a configuration using a remote source
+directory, it creates a tree for the binaries with the same structure
+(and using the same names) as the tree under the source directory. In
+the example, you'd find the Sun 4 library `libiberty.a' in the
+directory `gdb-sun4/libiberty', and GDB itself in `gdb-sun4/gdb'.
+
+ Make sure that your path to the `configure' script has just one
+instance of `gdb' in it. If your path to `configure' looks like
+`../gdb-7.4.1/gdb/configure', you are configuring only one subdirectory
+of GDB, not the whole package. This leads to build errors about
+missing include files such as `bfd/bfd.h'.
+
+ One popular reason to build several GDB configurations in separate
+directories is to configure GDB for cross-compiling (where GDB runs on
+one machine--the "host"--while debugging programs that run on another
+machine--the "target"). You specify a cross-debugging target by giving
+the `--target=TARGET' option to `configure'.
+
+ When you run `make' to build a program or library, you must run it
+in a configured directory--whatever directory you were in when you
+called `configure' (or one of its subdirectories).
+
+ The `Makefile' that `configure' generates in each source directory
+also runs recursively. If you type `make' in a source directory such
+as `gdb-7.4.1' (or in a separate configured directory configured with
+`--srcdir=DIRNAME/gdb-7.4.1'), you will build all the required
+libraries, and then build GDB.
+
+ When you have multiple hosts or targets configured in separate
+directories, you can run `make' on them in parallel (for example, if
+they are NFS-mounted on each of the hosts); they will not interfere
+with each other.
+
+
+File: gdb.info, Node: Config Names, Next: Configure Options, Prev: Separate Objdir, Up: Installing GDB
+
+C.4 Specifying Names for Hosts and Targets
+==========================================
+
+The specifications used for hosts and targets in the `configure' script
+are based on a three-part naming scheme, but some short predefined
+aliases are also supported. The full naming scheme encodes three pieces
+of information in the following pattern:
+
+ ARCHITECTURE-VENDOR-OS
+
+ For example, you can use the alias `sun4' as a HOST argument, or as
+the value for TARGET in a `--target=TARGET' option. The equivalent
+full name is `sparc-sun-sunos4'.
+
+ The `configure' script accompanying GDB does not provide any query
+facility to list all supported host and target names or aliases.
+`configure' calls the Bourne shell script `config.sub' to map
+abbreviations to full names; you can read the script, if you wish, or
+you can use it to test your guesses on abbreviations--for example:
+
+ % sh config.sub i386-linux
+ i386-pc-linux-gnu
+ % sh config.sub alpha-linux
+ alpha-unknown-linux-gnu
+ % sh config.sub hp9k700
+ hppa1.1-hp-hpux
+ % sh config.sub sun4
+ sparc-sun-sunos4.1.1
+ % sh config.sub sun3
+ m68k-sun-sunos4.1.1
+ % sh config.sub i986v
+ Invalid configuration `i986v': machine `i986v' not recognized
+
+`config.sub' is also distributed in the GDB source directory
+(`gdb-7.4.1', for version 7.4.1).
+
+
+File: gdb.info, Node: Configure Options, Next: System-wide configuration, Prev: Config Names, Up: Installing GDB
+
+C.5 `configure' Options
+=======================
+
+Here is a summary of the `configure' options and arguments that are
+most often useful for building GDB. `configure' also has several other
+options not listed here. *note (configure.info)What Configure Does::,
+for a full explanation of `configure'.
+
+ configure [--help]
+ [--prefix=DIR]
+ [--exec-prefix=DIR]
+ [--srcdir=DIRNAME]
+ [--norecursion] [--rm]
+ [--target=TARGET]
+ HOST
+
+You may introduce options with a single `-' rather than `--' if you
+prefer; but you may abbreviate option names if you use `--'.
+
+`--help'
+ Display a quick summary of how to invoke `configure'.
+
+`--prefix=DIR'
+ Configure the source to install programs and files under directory
+ `DIR'.
+
+`--exec-prefix=DIR'
+ Configure the source to install programs under directory `DIR'.
+
+`--srcdir=DIRNAME'
+ *Warning: using this option requires GNU `make', or another `make'
+ that implements the `VPATH' feature.*
+ Use this option to make configurations in directories separate
+ from the GDB source directories. Among other things, you can use
+ this to build (or maintain) several configurations simultaneously,
+ in separate directories. `configure' writes
+ configuration-specific files in the current directory, but
+ arranges for them to use the source in the directory DIRNAME.
+ `configure' creates directories under the working directory in
+ parallel to the source directories below DIRNAME.
+
+`--norecursion'
+ Configure only the directory level where `configure' is executed;
+ do not propagate configuration to subdirectories.
+
+`--target=TARGET'
+ Configure GDB for cross-debugging programs running on the specified
+ TARGET. Without this option, GDB is configured to debug programs
+ that run on the same machine (HOST) as GDB itself.
+
+ There is no convenient way to generate a list of all available
+ targets.
+
+`HOST ...'
+ Configure GDB to run on the specified HOST.
+
+ There is no convenient way to generate a list of all available
+ hosts.
+
+ There are many other options available as well, but they are
+generally needed for special purposes only.
+
+
+File: gdb.info, Node: System-wide configuration, Prev: Configure Options, Up: Installing GDB
+
+C.6 System-wide configuration and settings
+==========================================
+
+GDB can be configured to have a system-wide init file; this file will
+be read and executed at startup (*note What GDB does during startup:
+Startup.).
+
+ Here is the corresponding configure option:
+
+`--with-system-gdbinit=FILE'
+ Specify that the default location of the system-wide init file is
+ FILE.
+
+ If GDB has been configured with the option `--prefix=$prefix', it
+may be subject to relocation. Two possible cases:
+
+ * If the default location of this init file contains `$prefix', it
+ will be subject to relocation. Suppose that the configure options
+ are `--prefix=$prefix --with-system-gdbinit=$prefix/etc/gdbinit';
+ if GDB is moved from `$prefix' to `$install', the system init file
+ is looked for as `$install/etc/gdbinit' instead of
+ `$prefix/etc/gdbinit'.
+
+ * By contrast, if the default location does not contain the prefix,
+ it will not be relocated. E.g. if GDB has been configured with
+ `--prefix=/usr/local --with-system-gdbinit=/usr/share/gdb/gdbinit',
+ then GDB will always look for `/usr/share/gdb/gdbinit', wherever
+ GDB is installed.
+
+
+File: gdb.info, Node: Maintenance Commands, Next: Remote Protocol, Prev: Installing GDB, Up: Top
+
+Appendix D Maintenance Commands
+*******************************
+
+In addition to commands intended for GDB users, GDB includes a number
+of commands intended for GDB developers, that are not documented
+elsewhere in this manual. These commands are provided here for
+reference. (For commands that turn on debugging messages, see *Note
+Debugging Output::.)
+
+`maint agent EXPRESSION'
+`maint agent-eval EXPRESSION'
+ Translate the given EXPRESSION into remote agent bytecodes. This
+ command is useful for debugging the Agent Expression mechanism
+ (*note Agent Expressions::). The `agent' version produces an
+ expression useful for data collection, such as by tracepoints,
+ while `maint agent-eval' produces an expression that evaluates
+ directly to a result. For instance, a collection expression for
+ `globa + globb' will include bytecodes to record four bytes of
+ memory at each of the addresses of `globa' and `globb', while
+ discarding the result of the addition, while an evaluation
+ expression will do the addition and return the sum.
+
+`maint info breakpoints'
+ Using the same format as `info breakpoints', display both the
+ breakpoints you've set explicitly, and those GDB is using for
+ internal purposes. Internal breakpoints are shown with negative
+ breakpoint numbers. The type column identifies what kind of
+ breakpoint is shown:
+
+ `breakpoint'
+ Normal, explicitly set breakpoint.
+
+ `watchpoint'
+ Normal, explicitly set watchpoint.
+
+ `longjmp'
+ Internal breakpoint, used to handle correctly stepping through
+ `longjmp' calls.
+
+ `longjmp resume'
+ Internal breakpoint at the target of a `longjmp'.
+
+ `until'
+ Temporary internal breakpoint used by the GDB `until' command.
+
+ `finish'
+ Temporary internal breakpoint used by the GDB `finish'
+ command.
+
+ `shlib events'
+ Shared library events.
+
+
+`set displaced-stepping'
+`show displaced-stepping'
+ Control whether or not GDB will do "displaced stepping" if the
+ target supports it. Displaced stepping is a way to single-step
+ over breakpoints without removing them from the inferior, by
+ executing an out-of-line copy of the instruction that was
+ originally at the breakpoint location. It is also known as
+ out-of-line single-stepping.
+
+ `set displaced-stepping on'
+ If the target architecture supports it, GDB will use
+ displaced stepping to step over breakpoints.
+
+ `set displaced-stepping off'
+ GDB will not use displaced stepping to step over breakpoints,
+ even if such is supported by the target architecture.
+
+ `set displaced-stepping auto'
+ This is the default mode. GDB will use displaced stepping
+ only if non-stop mode is active (*note Non-Stop Mode::) and
+ the target architecture supports displaced stepping.
+
+`maint check-symtabs'
+ Check the consistency of psymtabs and symtabs.
+
+`maint cplus first_component NAME'
+ Print the first C++ class/namespace component of NAME.
+
+`maint cplus namespace'
+ Print the list of possible C++ namespaces.
+
+`maint demangle NAME'
+ Demangle a C++ or Objective-C mangled NAME.
+
+`maint deprecate COMMAND [REPLACEMENT]'
+`maint undeprecate COMMAND'
+ Deprecate or undeprecate the named COMMAND. Deprecated commands
+ cause GDB to issue a warning when you use them. The optional
+ argument REPLACEMENT says which newer command should be used in
+ favor of the deprecated one; if it is given, GDB will mention the
+ replacement as part of the warning.
+
+`maint dump-me'
+ Cause a fatal signal in the debugger and force it to dump its core.
+ This is supported only on systems which support aborting a program
+ with the `SIGQUIT' signal.
+
+`maint internal-error [MESSAGE-TEXT]'
+`maint internal-warning [MESSAGE-TEXT]'
+ Cause GDB to call the internal function `internal_error' or
+ `internal_warning' and hence behave as though an internal error or
+ internal warning has been detected. In addition to reporting the
+ internal problem, these functions give the user the opportunity to
+ either quit GDB or create a core file of the current GDB session.
+
+ These commands take an optional parameter MESSAGE-TEXT that is
+ used as the text of the error or warning message.
+
+ Here's an example of using `internal-error':
+
+ (gdb) maint internal-error testing, 1, 2
+ .../maint.c:121: internal-error: testing, 1, 2
+ A problem internal to GDB has been detected. Further
+ debugging may prove unreliable.
+ Quit this debugging session? (y or n) n
+ Create a core file? (y or n) n
+ (gdb)
+
+`maint set internal-error ACTION [ask|yes|no]'
+`maint show internal-error ACTION'
+`maint set internal-warning ACTION [ask|yes|no]'
+`maint show internal-warning ACTION'
+ When GDB reports an internal problem (error or warning) it gives
+ the user the opportunity to both quit GDB and create a core file
+ of the current GDB session. These commands let you override the
+ default behaviour for each particular ACTION, described in the
+ table below.
+
+ `quit'
+ You can specify that GDB should always (yes) or never (no)
+ quit. The default is to ask the user what to do.
+
+ `corefile'
+ You can specify that GDB should always (yes) or never (no)
+ create a core file. The default is to ask the user what to
+ do.
+
+`maint packet TEXT'
+ If GDB is talking to an inferior via the serial protocol, then
+ this command sends the string TEXT to the inferior, and displays
+ the response packet. GDB supplies the initial `$' character, the
+ terminating `#' character, and the checksum.
+
+`maint print architecture [FILE]'
+ Print the entire architecture configuration. The optional argument
+ FILE names the file where the output goes.
+
+`maint print c-tdesc'
+ Print the current target description (*note Target Descriptions::)
+ as a C source file. The created source file can be used in GDB
+ when an XML parser is not available to parse the description.
+
+`maint print dummy-frames'
+ Prints the contents of GDB's internal dummy-frame stack.
+
+ (gdb) b add
+ ...
+ (gdb) print add(2,3)
+ Breakpoint 2, add (a=2, b=3) at ...
+ 58 return (a + b);
+ The program being debugged stopped while in a function called from GDB.
+ ...
+ (gdb) maint print dummy-frames
+ 0x1a57c80: pc=0x01014068 fp=0x0200bddc sp=0x0200bdd6
+ top=0x0200bdd4 id={stack=0x200bddc,code=0x101405c}
+ call_lo=0x01014000 call_hi=0x01014001
+ (gdb)
+
+ Takes an optional file parameter.
+
+`maint print registers [FILE]'
+`maint print raw-registers [FILE]'
+`maint print cooked-registers [FILE]'
+`maint print register-groups [FILE]'
+`maint print remote-registers [FILE]'
+ Print GDB's internal register data structures.
+
+ The command `maint print raw-registers' includes the contents of
+ the raw register cache; the command `maint print cooked-registers'
+ includes the (cooked) value of all registers, including registers
+ which aren't available on the target nor visible to user; the
+ command `maint print register-groups' includes the groups that
+ each register is a member of; and the command `maint print
+ remote-registers' includes the remote target's register numbers
+ and offsets in the `G' packets. *Note Registers:
+ (gdbint)Registers.
+
+ These commands take an optional parameter, a file name to which to
+ write the information.
+
+`maint print reggroups [FILE]'
+ Print GDB's internal register group data structures. The optional
+ argument FILE tells to what file to write the information.
+
+ The register groups info looks like this:
+
+ (gdb) maint print reggroups
+ Group Type
+ general user
+ float user
+ all user
+ vector user
+ system user
+ save internal
+ restore internal
+
+`flushregs'
+ This command forces GDB to flush its internal register cache.
+
+`maint print objfiles'
+ Print a dump of all known object files. For each object file, this
+ command prints its name, address in memory, and all of its psymtabs
+ and symtabs.
+
+`maint print section-scripts [REGEXP]'
+ Print a dump of scripts specified in the `.debug_gdb_section'
+ section. If REGEXP is specified, only print scripts loaded by
+ object files matching REGEXP. For each script, this command
+ prints its name as specified in the objfile, and the full path if
+ known. *Note .debug_gdb_scripts section::.
+
+`maint print statistics'
+ This command prints, for each object file in the program, various
+ data about that object file followed by the byte cache ("bcache")
+ statistics for the object file. The objfile data includes the
+ number of minimal, partial, full, and stabs symbols, the number of
+ types defined by the objfile, the number of as yet unexpanded psym
+ tables, the number of line tables and string tables, and the
+ amount of memory used by the various tables. The bcache
+ statistics include the counts, sizes, and counts of duplicates of
+ all and unique objects, max, average, and median entry size, total
+ memory used and its overhead and savings, and various measures of
+ the hash table size and chain lengths.
+
+`maint print target-stack'
+ A "target" is an interface between the debugger and a particular
+ kind of file or process. Targets can be stacked in "strata", so
+ that more than one target can potentially respond to a request.
+ In particular, memory accesses will walk down the stack of targets
+ until they find a target that is interested in handling that
+ particular address.
+
+ This command prints a short description of each layer that was
+ pushed on the "target stack", starting from the top layer down to
+ the bottom one.
+
+`maint print type EXPR'
+ Print the type chain for a type specified by EXPR. The argument
+ can be either a type name or a symbol. If it is a symbol, the
+ type of that symbol is described. The type chain produced by this
+ command is a recursive definition of the data type as stored in
+ GDB's data structures, including its flags and contained types.
+
+`maint set dwarf2 always-disassemble'
+
+`maint show dwarf2 always-disassemble'
+ Control the behavior of `info address' when using DWARF debugging
+ information.
+
+ The default is `off', which means that GDB should try to describe
+ a variable's location in an easily readable format. When `on',
+ GDB will instead display the DWARF location expression in an
+ assembly-like format. Note that some locations are too complex
+ for GDB to describe simply; in this case you will always see the
+ disassembly form.
+
+ Here is an example of the resulting disassembly:
+
+ (gdb) info addr argc
+ Symbol "argc" is a complex DWARF expression:
+ 1: DW_OP_fbreg 0
+
+ For more information on these expressions, see the DWARF standard
+ (http://www.dwarfstd.org/).
+
+`maint set dwarf2 max-cache-age'
+`maint show dwarf2 max-cache-age'
+ Control the DWARF 2 compilation unit cache.
+
+ In object files with inter-compilation-unit references, such as
+ those produced by the GCC option `-feliminate-dwarf2-dups', the
+ DWARF 2 reader needs to frequently refer to previously read
+ compilation units. This setting controls how long a compilation
+ unit will remain in the cache if it is not referenced. A higher
+ limit means that cached compilation units will be stored in memory
+ longer, and more total memory will be used. Setting it to zero
+ disables caching, which will slow down GDB startup, but reduce
+ memory consumption.
+
+`maint set profile'
+`maint show profile'
+ Control profiling of GDB.
+
+ Profiling will be disabled until you use the `maint set profile'
+ command to enable it. When you enable profiling, the system will
+ begin collecting timing and execution count data; when you disable
+ profiling or exit GDB, the results will be written to a log file.
+ Remember that if you use profiling, GDB will overwrite the
+ profiling log file (often called `gmon.out'). If you have a
+ record of important profiling data in a `gmon.out' file, be sure
+ to move it to a safe location.
+
+ Configuring with `--enable-profiling' arranges for GDB to be
+ compiled with the `-pg' compiler option.
+
+`maint set show-debug-regs'
+`maint show show-debug-regs'
+ Control whether to show variables that mirror the hardware debug
+ registers. Use `ON' to enable, `OFF' to disable. If enabled, the
+ debug registers values are shown when GDB inserts or removes a
+ hardware breakpoint or watchpoint, and when the inferior triggers
+ a hardware-assisted breakpoint or watchpoint.
+
+`maint set show-all-tib'
+`maint show show-all-tib'
+ Control whether to show all non zero areas within a 1k block
+ starting at thread local base, when using the `info w32
+ thread-information-block' command.
+
+`maint space'
+ Control whether to display memory usage for each command. If set
+ to a nonzero value, GDB will display how much memory each command
+ took, following the command's own output. This can also be
+ requested by invoking GDB with the `--statistics' command-line
+ switch (*note Mode Options::).
+
+`maint time'
+ Control whether to display the execution time of GDB for each
+ command. If set to a nonzero value, GDB will display how much
+ time it took to execute each command, following the command's own
+ output. Both CPU time and wallclock time are printed. Printing
+ both is useful when trying to determine whether the cost is CPU
+ or, e.g., disk/network, latency. Note that the CPU time printed
+ is for GDB only, it does not include the execution time of the
+ inferior because there's no mechanism currently to compute how
+ much time was spent by GDB and how much time was spent by the
+ program been debugged. This can also be requested by invoking GDB
+ with the `--statistics' command-line switch (*note Mode Options::).
+
+`maint translate-address [SECTION] ADDR'
+ Find the symbol stored at the location specified by the address
+ ADDR and an optional section name SECTION. If found, GDB prints
+ the name of the closest symbol and an offset from the symbol's
+ location to the specified address. This is similar to the `info
+ address' command (*note Symbols::), except that this command also
+ allows to find symbols in other sections.
+
+ If section was not specified, the section in which the symbol was
+ found is also printed. For dynamically linked executables, the
+ name of executable or shared library containing the symbol is
+ printed as well.
+
+
+ The following command is useful for non-interactive invocations of
+GDB, such as in the test suite.
+
+`set watchdog NSEC'
+ Set the maximum number of seconds GDB will wait for the target
+ operation to finish. If this time expires, GDB reports and error
+ and the command is aborted.
+
+`show watchdog'
+ Show the current setting of the target wait timeout.
+
+
+File: gdb.info, Node: Remote Protocol, Next: Agent Expressions, Prev: Maintenance Commands, Up: Top
+
+Appendix E GDB Remote Serial Protocol
+*************************************
+
+* Menu:
+
+* Overview::
+* Packets::
+* Stop Reply Packets::
+* General Query Packets::
+* Architecture-Specific Protocol Details::
+* Tracepoint Packets::
+* Host I/O Packets::
+* Interrupts::
+* Notification Packets::
+* Remote Non-Stop::
+* Packet Acknowledgment::
+* Examples::
+* File-I/O Remote Protocol Extension::
+* Library List Format::
+* Library List Format for SVR4 Targets::
+* Memory Map Format::
+* Thread List Format::
+* Traceframe Info Format::
+
+
+File: gdb.info, Node: Overview, Next: Packets, Up: Remote Protocol
+
+E.1 Overview
+============
+
+There may be occasions when you need to know something about the
+protocol--for example, if there is only one serial port to your target
+machine, you might want your program to do something special if it
+recognizes a packet meant for GDB.
+
+ In the examples below, `->' and `<-' are used to indicate
+transmitted and received data, respectively.
+
+ All GDB commands and responses (other than acknowledgments and
+notifications, see *Note Notification Packets::) are sent as a PACKET.
+A PACKET is introduced with the character `$', the actual PACKET-DATA,
+and the terminating character `#' followed by a two-digit CHECKSUM:
+
+ `$'PACKET-DATA`#'CHECKSUM
+ The two-digit CHECKSUM is computed as the modulo 256 sum of all
+characters between the leading `$' and the trailing `#' (an eight bit
+unsigned checksum).
+
+ Implementors should note that prior to GDB 5.0 the protocol
+specification also included an optional two-digit SEQUENCE-ID:
+
+ `$'SEQUENCE-ID`:'PACKET-DATA`#'CHECKSUM
+
+That SEQUENCE-ID was appended to the acknowledgment. GDB has never
+output SEQUENCE-IDs. Stubs that handle packets added since GDB 5.0
+must not accept SEQUENCE-ID.
+
+ When either the host or the target machine receives a packet, the
+first response expected is an acknowledgment: either `+' (to indicate
+the package was received correctly) or `-' (to request retransmission):
+
+ -> `$'PACKET-DATA`#'CHECKSUM
+ <- `+'
+ The `+'/`-' acknowledgments can be disabled once a connection is
+established. *Note Packet Acknowledgment::, for details.
+
+ The host (GDB) sends COMMANDs, and the target (the debugging stub
+incorporated in your program) sends a RESPONSE. In the case of step
+and continue COMMANDs, the response is only sent when the operation has
+completed, and the target has again stopped all threads in all attached
+processes. This is the default all-stop mode behavior, but the remote
+protocol also supports GDB's non-stop execution mode; see *Note Remote
+Non-Stop::, for details.
+
+ PACKET-DATA consists of a sequence of characters with the exception
+of `#' and `$' (see `X' packet for additional exceptions).
+
+ Fields within the packet should be separated using `,' `;' or `:'.
+Except where otherwise noted all numbers are represented in HEX with
+leading zeros suppressed.
+
+ Implementors should note that prior to GDB 5.0, the character `:'
+could not appear as the third character in a packet (as it would
+potentially conflict with the SEQUENCE-ID).
+
+ Binary data in most packets is encoded either as two hexadecimal
+digits per byte of binary data. This allowed the traditional remote
+protocol to work over connections which were only seven-bit clean.
+Some packets designed more recently assume an eight-bit clean
+connection, and use a more efficient encoding to send and receive
+binary data.
+
+ The binary data representation uses `7d' (ASCII `}') as an escape
+character. Any escaped byte is transmitted as the escape character
+followed by the original character XORed with `0x20'. For example, the
+byte `0x7d' would be transmitted as the two bytes `0x7d 0x5d'. The
+bytes `0x23' (ASCII `#'), `0x24' (ASCII `$'), and `0x7d' (ASCII `}')
+must always be escaped. Responses sent by the stub must also escape
+`0x2a' (ASCII `*'), so that it is not interpreted as the start of a
+run-length encoded sequence (described next).
+
+ Response DATA can be run-length encoded to save space. Run-length
+encoding replaces runs of identical characters with one instance of the
+repeated character, followed by a `*' and a repeat count. The repeat
+count is itself sent encoded, to avoid binary characters in DATA: a
+value of N is sent as `N+29'. For a repeat count greater or equal to
+3, this produces a printable ASCII character, e.g. a space (ASCII code
+32) for a repeat count of 3. (This is because run-length encoding
+starts to win for counts 3 or more.) Thus, for example, `0* ' is a
+run-length encoding of "0000": the space character after `*' means
+repeat the leading `0' `32 - 29 = 3' more times.
+
+ The printable characters `#' and `$' or with a numeric value greater
+than 126 must not be used. Runs of six repeats (`#') or seven repeats
+(`$') can be expanded using a repeat count of only five (`"'). For
+example, `00000000' can be encoded as `0*"00'.
+
+ The error response returned for some packets includes a two character
+error number. That number is not well defined.
+
+ For any COMMAND not supported by the stub, an empty response
+(`$#00') should be returned. That way it is possible to extend the
+protocol. A newer GDB can tell if a packet is supported based on that
+response.
+
+ At a minimum, a stub is required to support the `g' and `G' commands
+for register access, and the `m' and `M' commands for memory access.
+Stubs that only control single-threaded targets can implement run
+control with the `c' (continue), and `s' (step) commands. Stubs that
+support multi-threading targets should support the `vCont' command.
+All other commands are optional.
+
+
+File: gdb.info, Node: Packets, Next: Stop Reply Packets, Prev: Overview, Up: Remote Protocol
+
+E.2 Packets
+===========
+
+The following table provides a complete list of all currently defined
+COMMANDs and their corresponding response DATA. *Note File-I/O Remote
+Protocol Extension::, for details about the File I/O extension of the
+remote protocol.
+
+ Each packet's description has a template showing the packet's overall
+syntax, followed by an explanation of the packet's meaning. We include
+spaces in some of the templates for clarity; these are not part of the
+packet's syntax. No GDB packet uses spaces to separate its components.
+For example, a template like `foo BAR BAZ' describes a packet
+beginning with the three ASCII bytes `foo', followed by a BAR, followed
+directly by a BAZ. GDB does not transmit a space character between the
+`foo' and the BAR, or between the BAR and the BAZ.
+
+ Several packets and replies include a THREAD-ID field to identify a
+thread. Normally these are positive numbers with a target-specific
+interpretation, formatted as big-endian hex strings. A THREAD-ID can
+also be a literal `-1' to indicate all threads, or `0' to pick any
+thread.
+
+ In addition, the remote protocol supports a multiprocess feature in
+which the THREAD-ID syntax is extended to optionally include both
+process and thread ID fields, as `pPID.TID'. The PID (process) and TID
+(thread) components each have the format described above: a positive
+number with target-specific interpretation formatted as a big-endian
+hex string, literal `-1' to indicate all processes or threads
+(respectively), or `0' to indicate an arbitrary process or thread.
+Specifying just a process, as `pPID', is equivalent to `pPID.-1'. It
+is an error to specify all processes but a specific thread, such as
+`p-1.TID'. Note that the `p' prefix is _not_ used for those packets
+and replies explicitly documented to include a process ID, rather than
+a THREAD-ID.
+
+ The multiprocess THREAD-ID syntax extensions are only used if both
+GDB and the stub report support for the `multiprocess' feature using
+`qSupported'. *Note multiprocess extensions::, for more information.
+
+ Note that all packet forms beginning with an upper- or lower-case
+letter, other than those described here, are reserved for future use.
+
+ Here are the packet descriptions.
+
+`!'
+ Enable extended mode. In extended mode, the remote server is made
+ persistent. The `R' packet is used to restart the program being
+ debugged.
+
+ Reply:
+ `OK'
+ The remote target both supports and has enabled extended mode.
+
+`?'
+ Indicate the reason the target halted. The reply is the same as
+ for step and continue. This packet has a special interpretation
+ when the target is in non-stop mode; see *Note Remote Non-Stop::.
+
+ Reply: *Note Stop Reply Packets::, for the reply specifications.
+
+`A ARGLEN,ARGNUM,ARG,...'
+ Initialized `argv[]' array passed into program. ARGLEN specifies
+ the number of bytes in the hex encoded byte stream ARG. See
+ `gdbserver' for more details.
+
+ Reply:
+ `OK'
+ The arguments were set.
+
+ `E NN'
+ An error occurred.
+
+`b BAUD'
+ (Don't use this packet; its behavior is not well-defined.) Change
+ the serial line speed to BAUD.
+
+ JTC: _When does the transport layer state change? When it's
+ received, or after the ACK is transmitted. In either case, there
+ are problems if the command or the acknowledgment packet is
+ dropped._
+
+ Stan: _If people really wanted to add something like this, and get
+ it working for the first time, they ought to modify ser-unix.c to
+ send some kind of out-of-band message to a specially-setup stub
+ and have the switch happen "in between" packets, so that from
+ remote protocol's point of view, nothing actually happened._
+
+`B ADDR,MODE'
+ Set (MODE is `S') or clear (MODE is `C') a breakpoint at ADDR.
+
+ Don't use this packet. Use the `Z' and `z' packets instead (*note
+ insert breakpoint or watchpoint packet::).
+
+`bc'
+ Backward continue. Execute the target system in reverse. No
+ parameter. *Note Reverse Execution::, for more information.
+
+ Reply: *Note Stop Reply Packets::, for the reply specifications.
+
+`bs'
+ Backward single step. Execute one instruction in reverse. No
+ parameter. *Note Reverse Execution::, for more information.
+
+ Reply: *Note Stop Reply Packets::, for the reply specifications.
+
+`c [ADDR]'
+ Continue. ADDR is address to resume. If ADDR is omitted, resume
+ at current address.
+
+ This packet is deprecated for multi-threading support. *Note
+ vCont packet::.
+
+ Reply: *Note Stop Reply Packets::, for the reply specifications.
+
+`C SIG[;ADDR]'
+ Continue with signal SIG (hex signal number). If `;ADDR' is
+ omitted, resume at same address.
+
+ This packet is deprecated for multi-threading support. *Note
+ vCont packet::.
+
+ Reply: *Note Stop Reply Packets::, for the reply specifications.
+
+`d'
+ Toggle debug flag.
+
+ Don't use this packet; instead, define a general set packet (*note
+ General Query Packets::).
+
+`D'
+`D;PID'
+ The first form of the packet is used to detach GDB from the remote
+ system. It is sent to the remote target before GDB disconnects
+ via the `detach' command.
+
+ The second form, including a process ID, is used when multiprocess
+ protocol extensions are enabled (*note multiprocess extensions::),
+ to detach only a specific process. The PID is specified as a
+ big-endian hex string.
+
+ Reply:
+ `OK'
+ for success
+
+ `E NN'
+ for an error
+
+`F RC,EE,CF;XX'
+ A reply from GDB to an `F' packet sent by the target. This is
+ part of the File-I/O protocol extension. *Note File-I/O Remote
+ Protocol Extension::, for the specification.
+
+`g'
+ Read general registers.
+
+ Reply:
+ `XX...'
+ Each byte of register data is described by two hex digits.
+ The bytes with the register are transmitted in target byte
+ order. The size of each register and their position within
+ the `g' packet are determined by the GDB internal gdbarch
+ functions `DEPRECATED_REGISTER_RAW_SIZE' and
+ `gdbarch_register_name'. The specification of several
+ standard `g' packets is specified below.
+
+ When reading registers from a trace frame (*note Using the
+ Collected Data: Analyze Collected Data.), the stub may also
+ return a string of literal `x''s in place of the register
+ data digits, to indicate that the corresponding register has
+ not been collected, thus its value is unavailable. For
+ example, for an architecture with 4 registers of 4 bytes
+ each, the following reply indicates to GDB that registers 0
+ and 2 have not been collected, while registers 1 and 3 have
+ been collected, and both have zero value:
+
+ -> `g'
+ <- `xxxxxxxx00000000xxxxxxxx00000000'
+
+ `E NN'
+ for an error.
+
+`G XX...'
+ Write general registers. *Note read registers packet::, for a
+ description of the XX... data.
+
+ Reply:
+ `OK'
+ for success
+
+ `E NN'
+ for an error
+
+`H OP THREAD-ID'
+ Set thread for subsequent operations (`m', `M', `g', `G', et.al.).
+ OP depends on the operation to be performed: it should be `c' for
+ step and continue operations (note that this is deprecated,
+ supporting the `vCont' command is a better option), `g' for other
+ operations. The thread designator THREAD-ID has the format and
+ interpretation described in *Note thread-id syntax::.
+
+ Reply:
+ `OK'
+ for success
+
+ `E NN'
+ for an error
+
+`i [ADDR[,NNN]]'
+ Step the remote target by a single clock cycle. If `,NNN' is
+ present, cycle step NNN cycles. If ADDR is present, cycle step
+ starting at that address.
+
+`I'
+ Signal, then cycle step. *Note step with signal packet::. *Note
+ cycle step packet::.
+
+`k'
+ Kill request.
+
+ FIXME: _There is no description of how to operate when a specific
+ thread context has been selected (i.e. does 'k' kill only that
+ thread?)_.
+
+`m ADDR,LENGTH'
+ Read LENGTH bytes of memory starting at address ADDR. Note that
+ ADDR may not be aligned to any particular boundary.
+
+ The stub need not use any particular size or alignment when
+ gathering data from memory for the response; even if ADDR is
+ word-aligned and LENGTH is a multiple of the word size, the stub
+ is free to use byte accesses, or not. For this reason, this
+ packet may not be suitable for accessing memory-mapped I/O devices.
+
+ Reply:
+ `XX...'
+ Memory contents; each byte is transmitted as a two-digit
+ hexadecimal number. The reply may contain fewer bytes than
+ requested if the server was able to read only part of the
+ region of memory.
+
+ `E NN'
+ NN is errno
+
+`M ADDR,LENGTH:XX...'
+ Write LENGTH bytes of memory starting at address ADDR. XX... is
+ the data; each byte is transmitted as a two-digit hexadecimal
+ number.
+
+ Reply:
+ `OK'
+ for success
+
+ `E NN'
+ for an error (this includes the case where only part of the
+ data was written).
+
+`p N'
+ Read the value of register N; N is in hex. *Note read registers
+ packet::, for a description of how the returned register value is
+ encoded.
+
+ Reply:
+ `XX...'
+ the register's value
+
+ `E NN'
+ for an error
+
+ `'
+ Indicating an unrecognized QUERY.
+
+`P N...=R...'
+ Write register N... with value R.... The register number N is in
+ hexadecimal, and R... contains two hex digits for each byte in the
+ register (target byte order).
+
+ Reply:
+ `OK'
+ for success
+
+ `E NN'
+ for an error
+
+`q NAME PARAMS...'
+`Q NAME PARAMS...'
+ General query (`q') and set (`Q'). These packets are described
+ fully in *Note General Query Packets::.
+
+`r'
+ Reset the entire system.
+
+ Don't use this packet; use the `R' packet instead.
+
+`R XX'
+ Restart the program being debugged. XX, while needed, is ignored.
+ This packet is only available in extended mode (*note extended
+ mode::).
+
+ The `R' packet has no reply.
+
+`s [ADDR]'
+ Single step. ADDR is the address at which to resume. If ADDR is
+ omitted, resume at same address.
+
+ This packet is deprecated for multi-threading support. *Note
+ vCont packet::.
+
+ Reply: *Note Stop Reply Packets::, for the reply specifications.
+
+`S SIG[;ADDR]'
+ Step with signal. This is analogous to the `C' packet, but
+ requests a single-step, rather than a normal resumption of
+ execution.
+
+ This packet is deprecated for multi-threading support. *Note
+ vCont packet::.
+
+ Reply: *Note Stop Reply Packets::, for the reply specifications.
+
+`t ADDR:PP,MM'
+ Search backwards starting at address ADDR for a match with pattern
+ PP and mask MM. PP and MM are 4 bytes. ADDR must be at least 3
+ digits.
+
+`T THREAD-ID'
+ Find out if the thread THREAD-ID is alive. *Note thread-id
+ syntax::.
+
+ Reply:
+ `OK'
+ thread is still alive
+
+ `E NN'
+ thread is dead
+
+`v'
+ Packets starting with `v' are identified by a multi-letter name,
+ up to the first `;' or `?' (or the end of the packet).
+
+`vAttach;PID'
+ Attach to a new process with the specified process ID PID. The
+ process ID is a hexadecimal integer identifying the process. In
+ all-stop mode, all threads in the attached process are stopped; in
+ non-stop mode, it may be attached without being stopped if that is
+ supported by the target.
+
+ This packet is only available in extended mode (*note extended
+ mode::).
+
+ Reply:
+ `E NN'
+ for an error
+
+ `Any stop packet'
+ for success in all-stop mode (*note Stop Reply Packets::)
+
+ `OK'
+ for success in non-stop mode (*note Remote Non-Stop::)
+
+`vCont[;ACTION[:THREAD-ID]]...'
+ Resume the inferior, specifying different actions for each thread.
+ If an action is specified with no THREAD-ID, then it is applied to
+ any threads that don't have a specific action specified; if no
+ default action is specified then other threads should remain
+ stopped in all-stop mode and in their current state in non-stop
+ mode. Specifying multiple default actions is an error; specifying
+ no actions is also an error. Thread IDs are specified using the
+ syntax described in *Note thread-id syntax::.
+
+ Currently supported actions are:
+
+ `c'
+ Continue.
+
+ `C SIG'
+ Continue with signal SIG. The signal SIG should be two hex
+ digits.
+
+ `s'
+ Step.
+
+ `S SIG'
+ Step with signal SIG. The signal SIG should be two hex
+ digits.
+
+ `t'
+ Stop.
+
+ The optional argument ADDR normally associated with the `c', `C',
+ `s', and `S' packets is not supported in `vCont'.
+
+ The `t' action is only relevant in non-stop mode (*note Remote
+ Non-Stop::) and may be ignored by the stub otherwise. A stop
+ reply should be generated for any affected thread not already
+ stopped. When a thread is stopped by means of a `t' action, the
+ corresponding stop reply should indicate that the thread has
+ stopped with signal `0', regardless of whether the target uses
+ some other signal as an implementation detail.
+
+ Reply: *Note Stop Reply Packets::, for the reply specifications.
+
+`vCont?'
+ Request a list of actions supported by the `vCont' packet.
+
+ Reply:
+ `vCont[;ACTION...]'
+ The `vCont' packet is supported. Each ACTION is a supported
+ command in the `vCont' packet.
+
+ `'
+ The `vCont' packet is not supported.
+
+`vFile:OPERATION:PARAMETER...'
+ Perform a file operation on the target system. For details, see
+ *Note Host I/O Packets::.
+
+`vFlashErase:ADDR,LENGTH'
+ Direct the stub to erase LENGTH bytes of flash starting at ADDR.
+ The region may enclose any number of flash blocks, but its start
+ and end must fall on block boundaries, as indicated by the flash
+ block size appearing in the memory map (*note Memory Map
+ Format::). GDB groups flash memory programming operations
+ together, and sends a `vFlashDone' request after each group; the
+ stub is allowed to delay erase operation until the `vFlashDone'
+ packet is received.
+
+ The stub must support `vCont' if it reports support for
+ multiprocess extensions (*note multiprocess extensions::). Note
+ that in this case `vCont' actions can be specified to apply to all
+ threads in a process by using the `pPID.-1' form of the THREAD-ID.
+
+ Reply:
+ `OK'
+ for success
+
+ `E NN'
+ for an error
+
+`vFlashWrite:ADDR:XX...'
+ Direct the stub to write data to flash address ADDR. The data is
+ passed in binary form using the same encoding as for the `X'
+ packet (*note Binary Data::). The memory ranges specified by
+ `vFlashWrite' packets preceding a `vFlashDone' packet must not
+ overlap, and must appear in order of increasing addresses
+ (although `vFlashErase' packets for higher addresses may already
+ have been received; the ordering is guaranteed only between
+ `vFlashWrite' packets). If a packet writes to an address that was
+ neither erased by a preceding `vFlashErase' packet nor by some
+ other target-specific method, the results are unpredictable.
+
+ Reply:
+ `OK'
+ for success
+
+ `E.memtype'
+ for vFlashWrite addressing non-flash memory
+
+ `E NN'
+ for an error
+
+`vFlashDone'
+ Indicate to the stub that flash programming operation is finished.
+ The stub is permitted to delay or batch the effects of a group of
+ `vFlashErase' and `vFlashWrite' packets until a `vFlashDone'
+ packet is received. The contents of the affected regions of flash
+ memory are unpredictable until the `vFlashDone' request is
+ completed.
+
+`vKill;PID'
+ Kill the process with the specified process ID. PID is a
+ hexadecimal integer identifying the process. This packet is used
+ in preference to `k' when multiprocess protocol extensions are
+ supported; see *Note multiprocess extensions::.
+
+ Reply:
+ `E NN'
+ for an error
+
+ `OK'
+ for success
+
+`vRun;FILENAME[;ARGUMENT]...'
+ Run the program FILENAME, passing it each ARGUMENT on its command
+ line. The file and arguments are hex-encoded strings. If
+ FILENAME is an empty string, the stub may use a default program
+ (e.g. the last program run). The program is created in the stopped
+ state.
+
+ This packet is only available in extended mode (*note extended
+ mode::).
+
+ Reply:
+ `E NN'
+ for an error
+
+ `Any stop packet'
+ for success (*note Stop Reply Packets::)
+
+`vStopped'
+ In non-stop mode (*note Remote Non-Stop::), acknowledge a previous
+ stop reply and prompt for the stub to report another one.
+
+ Reply:
+ `Any stop packet'
+ if there is another unreported stop event (*note Stop Reply
+ Packets::)
+
+ `OK'
+ if there are no unreported stop events
+
+`X ADDR,LENGTH:XX...'
+ Write data to memory, where the data is transmitted in binary.
+ ADDR is address, LENGTH is number of bytes, `XX...' is binary data
+ (*note Binary Data::).
+
+ Reply:
+ `OK'
+ for success
+
+ `E NN'
+ for an error
+
+`z TYPE,ADDR,KIND'
+`Z TYPE,ADDR,KIND'
+ Insert (`Z') or remove (`z') a TYPE breakpoint or watchpoint
+ starting at address ADDRESS of kind KIND.
+
+ Each breakpoint and watchpoint packet TYPE is documented
+ separately.
+
+ _Implementation notes: A remote target shall return an empty string
+ for an unrecognized breakpoint or watchpoint packet TYPE. A
+ remote target shall support either both or neither of a given
+ `ZTYPE...' and `zTYPE...' packet pair. To avoid potential
+ problems with duplicate packets, the operations should be
+ implemented in an idempotent way._
+
+`z0,ADDR,KIND'
+`Z0,ADDR,KIND'
+ Insert (`Z0') or remove (`z0') a memory breakpoint at address ADDR
+ of type KIND.
+
+ A memory breakpoint is implemented by replacing the instruction at
+ ADDR with a software breakpoint or trap instruction. The KIND is
+ target-specific and typically indicates the size of the breakpoint
+ in bytes that should be inserted. E.g., the ARM and MIPS can
+ insert either a 2 or 4 byte breakpoint. Some architectures have
+ additional meanings for KIND; see *Note Architecture-Specific
+ Protocol Details::.
+
+ _Implementation note: It is possible for a target to copy or move
+ code that contains memory breakpoints (e.g., when implementing
+ overlays). The behavior of this packet, in the presence of such a
+ target, is not defined._
+
+ Reply:
+ `OK'
+ success
+
+ `'
+ not supported
+
+ `E NN'
+ for an error
+
+`z1,ADDR,KIND'
+`Z1,ADDR,KIND'
+ Insert (`Z1') or remove (`z1') a hardware breakpoint at address
+ ADDR.
+
+ A hardware breakpoint is implemented using a mechanism that is not
+ dependant on being able to modify the target's memory. KIND has
+ the same meaning as in `Z0' packets.
+
+ _Implementation note: A hardware breakpoint is not affected by code
+ movement._
+
+ Reply:
+ `OK'
+ success
+
+ `'
+ not supported
+
+ `E NN'
+ for an error
+
+`z2,ADDR,KIND'
+`Z2,ADDR,KIND'
+ Insert (`Z2') or remove (`z2') a write watchpoint at ADDR. KIND
+ is interpreted as the number of bytes to watch.
+
+ Reply:
+ `OK'
+ success
+
+ `'
+ not supported
+
+ `E NN'
+ for an error
+
+`z3,ADDR,KIND'
+`Z3,ADDR,KIND'
+ Insert (`Z3') or remove (`z3') a read watchpoint at ADDR. KIND is
+ interpreted as the number of bytes to watch.
+
+ Reply:
+ `OK'
+ success
+
+ `'
+ not supported
+
+ `E NN'
+ for an error
+
+`z4,ADDR,KIND'
+`Z4,ADDR,KIND'
+ Insert (`Z4') or remove (`z4') an access watchpoint at ADDR. KIND
+ is interpreted as the number of bytes to watch.
+
+ Reply:
+ `OK'
+ success
+
+ `'
+ not supported
+
+ `E NN'
+ for an error
+
+
+
+File: gdb.info, Node: Stop Reply Packets, Next: General Query Packets, Prev: Packets, Up: Remote Protocol
+
+E.3 Stop Reply Packets
+======================
+
+The `C', `c', `S', `s', `vCont', `vAttach', `vRun', `vStopped', and `?'
+packets can receive any of the below as a reply. Except for `?' and
+`vStopped', that reply is only returned when the target halts. In the
+below the exact meaning of "signal number" is defined by the header
+`include/gdb/signals.h' in the GDB source code.
+
+ As in the description of request packets, we include spaces in the
+reply templates for clarity; these are not part of the reply packet's
+syntax. No GDB stop reply packet uses spaces to separate its
+components.
+
+`S AA'
+ The program received signal number AA (a two-digit hexadecimal
+ number). This is equivalent to a `T' response with no N:R pairs.
+
+`T AA N1:R1;N2:R2;...'
+ The program received signal number AA (a two-digit hexadecimal
+ number). This is equivalent to an `S' response, except that the
+ `N:R' pairs can carry values of important registers and other
+ information directly in the stop reply packet, reducing round-trip
+ latency. Single-step and breakpoint traps are reported this way.
+ Each `N:R' pair is interpreted as follows:
+
+ * If N is a hexadecimal number, it is a register number, and the
+ corresponding R gives that register's value. R is a series
+ of bytes in target byte order, with each byte given by a
+ two-digit hex number.
+
+ * If N is `thread', then R is the THREAD-ID of the stopped
+ thread, as specified in *Note thread-id syntax::.
+
+ * If N is `core', then R is the hexadecimal number of the core
+ on which the stop event was detected.
+
+ * If N is a recognized "stop reason", it describes a more
+ specific event that stopped the target. The currently
+ defined stop reasons are listed below. AA should be `05',
+ the trap signal. At most one stop reason should be present.
+
+ * Otherwise, GDB should ignore this `N:R' pair and go on to the
+ next; this allows us to extend the protocol in the future.
+
+ The currently defined stop reasons are:
+
+ `watch'
+ `rwatch'
+ `awatch'
+ The packet indicates a watchpoint hit, and R is the data
+ address, in hex.
+
+ `library'
+ The packet indicates that the loaded libraries have changed.
+ GDB should use `qXfer:libraries:read' to fetch a new list of
+ loaded libraries. R is ignored.
+
+ `replaylog'
+ The packet indicates that the target cannot continue replaying
+ logged execution events, because it has reached the end (or
+ the beginning when executing backward) of the log. The value
+ of R will be either `begin' or `end'. *Note Reverse
+ Execution::, for more information.
+
+`W AA'
+`W AA ; process:PID'
+ The process exited, and AA is the exit status. This is only
+ applicable to certain targets.
+
+ The second form of the response, including the process ID of the
+ exited process, can be used only when GDB has reported support for
+ multiprocess protocol extensions; see *Note multiprocess
+ extensions::. The PID is formatted as a big-endian hex string.
+
+`X AA'
+`X AA ; process:PID'
+ The process terminated with signal AA.
+
+ The second form of the response, including the process ID of the
+ terminated process, can be used only when GDB has reported support
+ for multiprocess protocol extensions; see *Note multiprocess
+ extensions::. The PID is formatted as a big-endian hex string.
+
+`O XX...'
+ `XX...' is hex encoding of ASCII data, to be written as the
+ program's console output. This can happen at any time while the
+ program is running and the debugger should continue to wait for
+ `W', `T', etc. This reply is not permitted in non-stop mode.
+
+`F CALL-ID,PARAMETER...'
+ CALL-ID is the identifier which says which host system call should
+ be called. This is just the name of the function. Translation
+ into the correct system call is only applicable as it's defined in
+ GDB. *Note File-I/O Remote Protocol Extension::, for a list of
+ implemented system calls.
+
+ `PARAMETER...' is a list of parameters as defined for this very
+ system call.
+
+ The target replies with this packet when it expects GDB to call a
+ host system call on behalf of the target. GDB replies with an
+ appropriate `F' packet and keeps up waiting for the next reply
+ packet from the target. The latest `C', `c', `S' or `s' action is
+ expected to be continued. *Note File-I/O Remote Protocol
+ Extension::, for more details.
+
+
diff --git a/gdb/doc/gdb.info-5 b/gdb/doc/gdb.info-5
new file mode 100644
index 0000000..cfc43f4
--- /dev/null
+++ b/gdb/doc/gdb.info-5
@@ -0,0 +1,5835 @@
+This is gdb.info, produced by makeinfo version 4.8 from ./gdb.texinfo.
+
+INFO-DIR-SECTION Software development
+START-INFO-DIR-ENTRY
+* Gdb: (gdb). The GNU debugger.
+END-INFO-DIR-ENTRY
+
+ Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996,
+1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009,
+2010 Free Software Foundation, Inc.
+
+ Permission is granted to copy, distribute and/or modify this document
+under the terms of the GNU Free Documentation License, Version 1.3 or
+any later version published by the Free Software Foundation; with the
+Invariant Sections being "Free Software" and "Free Software Needs Free
+Documentation", with the Front-Cover Texts being "A GNU Manual," and
+with the Back-Cover Texts as in (a) below.
+
+ (a) The FSF's Back-Cover Text is: "You are free to copy and modify
+this GNU Manual. Buying copies from GNU Press supports the FSF in
+developing GNU and promoting software freedom."
+
+ This file documents the GNU debugger GDB.
+
+ This is the Tenth Edition, of `Debugging with GDB: the GNU
+Source-Level Debugger' for GDB (GDB) Version 7.4.1.
+
+ Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996,
+1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009,
+2010 Free Software Foundation, Inc.
+
+ Permission is granted to copy, distribute and/or modify this document
+under the terms of the GNU Free Documentation License, Version 1.3 or
+any later version published by the Free Software Foundation; with the
+Invariant Sections being "Free Software" and "Free Software Needs Free
+Documentation", with the Front-Cover Texts being "A GNU Manual," and
+with the Back-Cover Texts as in (a) below.
+
+ (a) The FSF's Back-Cover Text is: "You are free to copy and modify
+this GNU Manual. Buying copies from GNU Press supports the FSF in
+developing GNU and promoting software freedom."
+
+
+File: gdb.info, Node: General Query Packets, Next: Architecture-Specific Protocol Details, Prev: Stop Reply Packets, Up: Remote Protocol
+
+E.4 General Query Packets
+=========================
+
+Packets starting with `q' are "general query packets"; packets starting
+with `Q' are "general set packets". General query and set packets are
+a semi-unified form for retrieving and sending information to and from
+the stub.
+
+ The initial letter of a query or set packet is followed by a name
+indicating what sort of thing the packet applies to. For example, GDB
+may use a `qSymbol' packet to exchange symbol definitions with the
+stub. These packet names follow some conventions:
+
+ * The name must not contain commas, colons or semicolons.
+
+ * Most GDB query and set packets have a leading upper case letter.
+
+ * The names of custom vendor packets should use a company prefix, in
+ lower case, followed by a period. For example, packets designed at
+ the Acme Corporation might begin with `qacme.foo' (for querying
+ foos) or `Qacme.bar' (for setting bars).
+
+ The name of a query or set packet should be separated from any
+parameters by a `:'; the parameters themselves should be separated by
+`,' or `;'. Stubs must be careful to match the full packet name, and
+check for a separator or the end of the packet, in case two packet
+names share a common prefix. New packets should not begin with `qC',
+`qP', or `qL'(1).
+
+ Like the descriptions of the other packets, each description here
+has a template showing the packet's overall syntax, followed by an
+explanation of the packet's meaning. We include spaces in some of the
+templates for clarity; these are not part of the packet's syntax. No
+GDB packet uses spaces to separate its components.
+
+ Here are the currently defined query and set packets:
+
+`QAllow:OP:VAL...'
+ Specify which operations GDB expects to request of the target, as
+ a semicolon-separated list of operation name and value pairs.
+ Possible values for OP include `WriteReg', `WriteMem',
+ `InsertBreak', `InsertTrace', `InsertFastTrace', and `Stop'. VAL
+ is either 0, indicating that GDB will not request the operation,
+ or 1, indicating that it may. (The target can then use this to
+ set up its own internals optimally, for instance if the debugger
+ never expects to insert breakpoints, it may not need to install
+ its own trap handler.)
+
+`qC'
+ Return the current thread ID.
+
+ Reply:
+ `QC THREAD-ID'
+ Where THREAD-ID is a thread ID as documented in *Note
+ thread-id syntax::.
+
+ `(anything else)'
+ Any other reply implies the old thread ID.
+
+`qCRC:ADDR,LENGTH'
+ Compute the CRC checksum of a block of memory using CRC-32 defined
+ in IEEE 802.3. The CRC is computed byte at a time, taking the most
+ significant bit of each byte first. The initial pattern code
+ `0xffffffff' is used to ensure leading zeros affect the CRC.
+
+ _Note:_ This is the same CRC used in validating separate debug
+ files (*note Debugging Information in Separate Files: Separate
+ Debug Files.). However the algorithm is slightly different. When
+ validating separate debug files, the CRC is computed taking the
+ _least_ significant bit of each byte first, and the final result
+ is inverted to detect trailing zeros.
+
+ Reply:
+ `E NN'
+ An error (such as memory fault)
+
+ `C CRC32'
+ The specified memory region's checksum is CRC32.
+
+`QDisableRandomization:VALUE'
+ Some target operating systems will randomize the virtual address
+ space of the inferior process as a security feature, but provide a
+ feature to disable such randomization, e.g. to allow for a more
+ deterministic debugging experience. On such systems, this packet
+ with a VALUE of 1 directs the target to disable address space
+ randomization for processes subsequently started via `vRun'
+ packets, while a packet with a VALUE of 0 tells the target to
+ enable address space randomization.
+
+ This packet is only available in extended mode (*note extended
+ mode::).
+
+ Reply:
+ `OK'
+ The request succeeded.
+
+ `E NN'
+ An error occurred. NN are hex digits.
+
+ `'
+ An empty reply indicates that `QDisableRandomization' is not
+ supported by the stub.
+
+ This packet is not probed by default; the remote stub must request
+ it, by supplying an appropriate `qSupported' response (*note
+ qSupported::). This should only be done on targets that actually
+ support disabling address space randomization.
+
+`qfThreadInfo'
+`qsThreadInfo'
+ Obtain a list of all active thread IDs from the target (OS).
+ Since there may be too many active threads to fit into one reply
+ packet, this query works iteratively: it may require more than one
+ query/reply sequence to obtain the entire list of threads. The
+ first query of the sequence will be the `qfThreadInfo' query;
+ subsequent queries in the sequence will be the `qsThreadInfo'
+ query.
+
+ NOTE: This packet replaces the `qL' query (see below).
+
+ Reply:
+ `m THREAD-ID'
+ A single thread ID
+
+ `m THREAD-ID,THREAD-ID...'
+ a comma-separated list of thread IDs
+
+ `l'
+ (lower case letter `L') denotes end of list.
+
+ In response to each query, the target will reply with a list of
+ one or more thread IDs, separated by commas. GDB will respond to
+ each reply with a request for more thread ids (using the `qs' form
+ of the query), until the target responds with `l' (lower-case ell,
+ for "last"). Refer to *Note thread-id syntax::, for the format of
+ the THREAD-ID fields.
+
+`qGetTLSAddr:THREAD-ID,OFFSET,LM'
+ Fetch the address associated with thread local storage specified
+ by THREAD-ID, OFFSET, and LM.
+
+ THREAD-ID is the thread ID associated with the thread for which to
+ fetch the TLS address. *Note thread-id syntax::.
+
+ OFFSET is the (big endian, hex encoded) offset associated with the
+ thread local variable. (This offset is obtained from the debug
+ information associated with the variable.)
+
+ LM is the (big endian, hex encoded) OS/ABI-specific encoding of the
+ load module associated with the thread local storage. For example,
+ a GNU/Linux system will pass the link map address of the shared
+ object associated with the thread local storage under
+ consideration. Other operating environments may choose to
+ represent the load module differently, so the precise meaning of
+ this parameter will vary.
+
+ Reply:
+ `XX...'
+ Hex encoded (big endian) bytes representing the address of
+ the thread local storage requested.
+
+ `E NN'
+ An error occurred. NN are hex digits.
+
+ `'
+ An empty reply indicates that `qGetTLSAddr' is not supported
+ by the stub.
+
+`qGetTIBAddr:THREAD-ID'
+ Fetch address of the Windows OS specific Thread Information Block.
+
+ THREAD-ID is the thread ID associated with the thread.
+
+ Reply:
+ `XX...'
+ Hex encoded (big endian) bytes representing the linear
+ address of the thread information block.
+
+ `E NN'
+ An error occured. This means that either the thread was not
+ found, or the address could not be retrieved.
+
+ `'
+ An empty reply indicates that `qGetTIBAddr' is not supported
+ by the stub.
+
+`qL STARTFLAG THREADCOUNT NEXTTHREAD'
+ Obtain thread information from RTOS. Where: STARTFLAG (one hex
+ digit) is one to indicate the first query and zero to indicate a
+ subsequent query; THREADCOUNT (two hex digits) is the maximum
+ number of threads the response packet can contain; and NEXTTHREAD
+ (eight hex digits), for subsequent queries (STARTFLAG is zero), is
+ returned in the response as ARGTHREAD.
+
+ Don't use this packet; use the `qfThreadInfo' query instead (see
+ above).
+
+ Reply:
+ `qM COUNT DONE ARGTHREAD THREAD...'
+ Where: COUNT (two hex digits) is the number of threads being
+ returned; DONE (one hex digit) is zero to indicate more
+ threads and one indicates no further threads; ARGTHREADID
+ (eight hex digits) is NEXTTHREAD from the request packet;
+ THREAD... is a sequence of thread IDs from the target.
+ THREADID (eight hex digits). See
+ `remote.c:parse_threadlist_response()'.
+
+`qOffsets'
+ Get section offsets that the target used when relocating the
+ downloaded image.
+
+ Reply:
+ `Text=XXX;Data=YYY[;Bss=ZZZ]'
+ Relocate the `Text' section by XXX from its original address.
+ Relocate the `Data' section by YYY from its original address.
+ If the object file format provides segment information (e.g.
+ ELF `PT_LOAD' program headers), GDB will relocate entire
+ segments by the supplied offsets.
+
+ _Note: while a `Bss' offset may be included in the response,
+ GDB ignores this and instead applies the `Data' offset to the
+ `Bss' section._
+
+ `TextSeg=XXX[;DataSeg=YYY]'
+ Relocate the first segment of the object file, which
+ conventionally contains program code, to a starting address
+ of XXX. If `DataSeg' is specified, relocate the second
+ segment, which conventionally contains modifiable data, to a
+ starting address of YYY. GDB will report an error if the
+ object file does not contain segment information, or does not
+ contain at least as many segments as mentioned in the reply.
+ Extra segments are kept at fixed offsets relative to the last
+ relocated segment.
+
+`qP MODE THREAD-ID'
+ Returns information on THREAD-ID. Where: MODE is a hex encoded 32
+ bit mode; THREAD-ID is a thread ID (*note thread-id syntax::).
+
+ Don't use this packet; use the `qThreadExtraInfo' query instead
+ (see below).
+
+ Reply: see `remote.c:remote_unpack_thread_info_response()'.
+
+`QNonStop:1'
+
+`QNonStop:0'
+ Enter non-stop (`QNonStop:1') or all-stop (`QNonStop:0') mode.
+ *Note Remote Non-Stop::, for more information.
+
+ Reply:
+ `OK'
+ The request succeeded.
+
+ `E NN'
+ An error occurred. NN are hex digits.
+
+ `'
+ An empty reply indicates that `QNonStop' is not supported by
+ the stub.
+
+ This packet is not probed by default; the remote stub must request
+ it, by supplying an appropriate `qSupported' response (*note
+ qSupported::). Use of this packet is controlled by the `set
+ non-stop' command; *note Non-Stop Mode::.
+
+`QPassSignals: SIGNAL [;SIGNAL]...'
+ Each listed SIGNAL should be passed directly to the inferior
+ process. Signals are numbered identically to continue packets and
+ stop replies (*note Stop Reply Packets::). Each SIGNAL list item
+ should be strictly greater than the previous item. These signals
+ do not need to stop the inferior, or be reported to GDB. All
+ other signals should be reported to GDB. Multiple `QPassSignals'
+ packets do not combine; any earlier `QPassSignals' list is
+ completely replaced by the new list. This packet improves
+ performance when using `handle SIGNAL nostop noprint pass'.
+
+ Reply:
+ `OK'
+ The request succeeded.
+
+ `E NN'
+ An error occurred. NN are hex digits.
+
+ `'
+ An empty reply indicates that `QPassSignals' is not supported
+ by the stub.
+
+ Use of this packet is controlled by the `set remote pass-signals'
+ command (*note set remote pass-signals: Remote Configuration.).
+ This packet is not probed by default; the remote stub must request
+ it, by supplying an appropriate `qSupported' response (*note
+ qSupported::).
+
+`qRcmd,COMMAND'
+ COMMAND (hex encoded) is passed to the local interpreter for
+ execution. Invalid commands should be reported using the output
+ string. Before the final result packet, the target may also
+ respond with a number of intermediate `OOUTPUT' console output
+ packets. _Implementors should note that providing access to a
+ stubs's interpreter may have security implications_.
+
+ Reply:
+ `OK'
+ A command response with no output.
+
+ `OUTPUT'
+ A command response with the hex encoded output string OUTPUT.
+
+ `E NN'
+ Indicate a badly formed request.
+
+ `'
+ An empty reply indicates that `qRcmd' is not recognized.
+
+ (Note that the `qRcmd' packet's name is separated from the command
+ by a `,', not a `:', contrary to the naming conventions above.
+ Please don't use this packet as a model for new packets.)
+
+`qSearch:memory:ADDRESS;LENGTH;SEARCH-PATTERN'
+ Search LENGTH bytes at ADDRESS for SEARCH-PATTERN. ADDRESS and
+ LENGTH are encoded in hex. SEARCH-PATTERN is a sequence of bytes,
+ hex encoded.
+
+ Reply:
+ `0'
+ The pattern was not found.
+
+ `1,address'
+ The pattern was found at ADDRESS.
+
+ `E NN'
+ A badly formed request or an error was encountered while
+ searching memory.
+
+ `'
+ An empty reply indicates that `qSearch:memory' is not
+ recognized.
+
+`QStartNoAckMode'
+ Request that the remote stub disable the normal `+'/`-' protocol
+ acknowledgments (*note Packet Acknowledgment::).
+
+ Reply:
+ `OK'
+ The stub has switched to no-acknowledgment mode. GDB
+ acknowledges this reponse, but neither the stub nor GDB shall
+ send or expect further `+'/`-' acknowledgments in the current
+ connection.
+
+ `'
+ An empty reply indicates that the stub does not support
+ no-acknowledgment mode.
+
+`qSupported [:GDBFEATURE [;GDBFEATURE]... ]'
+ Tell the remote stub about features supported by GDB, and query
+ the stub for features it supports. This packet allows GDB and the
+ remote stub to take advantage of each others' features.
+ `qSupported' also consolidates multiple feature probes at startup,
+ to improve GDB performance--a single larger packet performs better
+ than multiple smaller probe packets on high-latency links. Some
+ features may enable behavior which must not be on by default, e.g.
+ because it would confuse older clients or stubs. Other features
+ may describe packets which could be automatically probed for, but
+ are not. These features must be reported before GDB will use
+ them. This "default unsupported" behavior is not appropriate for
+ all packets, but it helps to keep the initial connection time
+ under control with new versions of GDB which support increasing
+ numbers of packets.
+
+ Reply:
+ `STUBFEATURE [;STUBFEATURE]...'
+ The stub supports or does not support each returned
+ STUBFEATURE, depending on the form of each STUBFEATURE (see
+ below for the possible forms).
+
+ `'
+ An empty reply indicates that `qSupported' is not recognized,
+ or that no features needed to be reported to GDB.
+
+ The allowed forms for each feature (either a GDBFEATURE in the
+ `qSupported' packet, or a STUBFEATURE in the response) are:
+
+ `NAME=VALUE'
+ The remote protocol feature NAME is supported, and associated
+ with the specified VALUE. The format of VALUE depends on the
+ feature, but it must not include a semicolon.
+
+ `NAME+'
+ The remote protocol feature NAME is supported, and does not
+ need an associated value.
+
+ `NAME-'
+ The remote protocol feature NAME is not supported.
+
+ `NAME?'
+ The remote protocol feature NAME may be supported, and GDB
+ should auto-detect support in some other way when it is
+ needed. This form will not be used for GDBFEATURE
+ notifications, but may be used for STUBFEATURE responses.
+
+ Whenever the stub receives a `qSupported' request, the supplied
+ set of GDB features should override any previous request. This
+ allows GDB to put the stub in a known state, even if the stub had
+ previously been communicating with a different version of GDB.
+
+ The following values of GDBFEATURE (for the packet sent by GDB)
+ are defined:
+
+ `multiprocess'
+ This feature indicates whether GDB supports multiprocess
+ extensions to the remote protocol. GDB does not use such
+ extensions unless the stub also reports that it supports them
+ by including `multiprocess+' in its `qSupported' reply.
+ *Note multiprocess extensions::, for details.
+
+ `xmlRegisters'
+ This feature indicates that GDB supports the XML target
+ description. If the stub sees `xmlRegisters=' with target
+ specific strings separated by a comma, it will report register
+ description.
+
+ `qRelocInsn'
+ This feature indicates whether GDB supports the `qRelocInsn'
+ packet (*note Relocate instruction reply packet: Tracepoint
+ Packets.).
+
+ Stubs should ignore any unknown values for GDBFEATURE. Any GDB
+ which sends a `qSupported' packet supports receiving packets of
+ unlimited length (earlier versions of GDB may reject overly long
+ responses). Additional values for GDBFEATURE may be defined in
+ the future to let the stub take advantage of new features in GDB,
+ e.g. incompatible improvements in the remote protocol--the
+ `multiprocess' feature is an example of such a feature. The
+ stub's reply should be independent of the GDBFEATURE entries sent
+ by GDB; first GDB describes all the features it supports, and then
+ the stub replies with all the features it supports.
+
+ Similarly, GDB will silently ignore unrecognized stub feature
+ responses, as long as each response uses one of the standard forms.
+
+ Some features are flags. A stub which supports a flag feature
+ should respond with a `+' form response. Other features require
+ values, and the stub should respond with an `=' form response.
+
+ Each feature has a default value, which GDB will use if
+ `qSupported' is not available or if the feature is not mentioned
+ in the `qSupported' response. The default values are fixed; a
+ stub is free to omit any feature responses that match the defaults.
+
+ Not all features can be probed, but for those which can, the
+ probing mechanism is useful: in some cases, a stub's internal
+ architecture may not allow the protocol layer to know some
+ information about the underlying target in advance. This is
+ especially common in stubs which may be configured for multiple
+ targets.
+
+ These are the currently defined stub features and their properties:
+
+ Feature Name Value Default Probe Allowed
+ Required
+ `PacketSize' Yes `-' No
+ `qXfer:auxv:read' No `-' Yes
+ `qXfer:features:read' No `-' Yes
+ `qXfer:libraries:read' No `-' Yes
+ `qXfer:memory-map:read' No `-' Yes
+ `qXfer:sdata:read' No `-' Yes
+ `qXfer:spu:read' No `-' Yes
+ `qXfer:spu:write' No `-' Yes
+ `qXfer:siginfo:read' No `-' Yes
+ `qXfer:siginfo:write' No `-' Yes
+ `qXfer:threads:read' No `-' Yes
+ `qXfer:traceframe-info:read'No `-' Yes
+ `qXfer:fdpic:read' No `-' Yes
+ `QNonStop' No `-' Yes
+ `QPassSignals' No `-' Yes
+ `QStartNoAckMode' No `-' Yes
+ `multiprocess' No `-' No
+ `ConditionalTracepoints'No `-' No
+ `ReverseContinue' No `-' No
+ `ReverseStep' No `-' No
+ `TracepointSource' No `-' No
+ `QAllow' No `-' No
+ `QDisableRandomization' No `-' No
+ `EnableDisableTracepoints'No `-' No
+ `tracenz' No `-' No
+
+ These are the currently defined stub features, in more detail:
+
+ `PacketSize=BYTES'
+ The remote stub can accept packets up to at least BYTES in
+ length. GDB will send packets up to this size for bulk
+ transfers, and will never send larger packets. This is a
+ limit on the data characters in the packet, including the
+ frame and checksum. There is no trailing NUL byte in a
+ remote protocol packet; if the stub stores packets in a
+ NUL-terminated format, it should allow an extra byte in its
+ buffer for the NUL. If this stub feature is not supported,
+ GDB guesses based on the size of the `g' packet response.
+
+ `qXfer:auxv:read'
+ The remote stub understands the `qXfer:auxv:read' packet
+ (*note qXfer auxiliary vector read::).
+
+ `qXfer:features:read'
+ The remote stub understands the `qXfer:features:read' packet
+ (*note qXfer target description read::).
+
+ `qXfer:libraries:read'
+ The remote stub understands the `qXfer:libraries:read' packet
+ (*note qXfer library list read::).
+
+ `qXfer:libraries-svr4:read'
+ The remote stub understands the `qXfer:libraries-svr4:read'
+ packet (*note qXfer svr4 library list read::).
+
+ `qXfer:memory-map:read'
+ The remote stub understands the `qXfer:memory-map:read' packet
+ (*note qXfer memory map read::).
+
+ `qXfer:sdata:read'
+ The remote stub understands the `qXfer:sdata:read' packet
+ (*note qXfer sdata read::).
+
+ `qXfer:spu:read'
+ The remote stub understands the `qXfer:spu:read' packet
+ (*note qXfer spu read::).
+
+ `qXfer:spu:write'
+ The remote stub understands the `qXfer:spu:write' packet
+ (*note qXfer spu write::).
+
+ `qXfer:siginfo:read'
+ The remote stub understands the `qXfer:siginfo:read' packet
+ (*note qXfer siginfo read::).
+
+ `qXfer:siginfo:write'
+ The remote stub understands the `qXfer:siginfo:write' packet
+ (*note qXfer siginfo write::).
+
+ `qXfer:threads:read'
+ The remote stub understands the `qXfer:threads:read' packet
+ (*note qXfer threads read::).
+
+ `qXfer:traceframe-info:read'
+ The remote stub understands the `qXfer:traceframe-info:read'
+ packet (*note qXfer traceframe info read::).
+
+ `qXfer:fdpic:read'
+ The remote stub understands the `qXfer:fdpic:read' packet
+ (*note qXfer fdpic loadmap read::).
+
+ `QNonStop'
+ The remote stub understands the `QNonStop' packet (*note
+ QNonStop::).
+
+ `QPassSignals'
+ The remote stub understands the `QPassSignals' packet (*note
+ QPassSignals::).
+
+ `QStartNoAckMode'
+ The remote stub understands the `QStartNoAckMode' packet and
+ prefers to operate in no-acknowledgment mode. *Note Packet
+ Acknowledgment::.
+
+ `multiprocess'
+ The remote stub understands the multiprocess extensions to
+ the remote protocol syntax. The multiprocess extensions
+ affect the syntax of thread IDs in both packets and replies
+ (*note thread-id syntax::), and add process IDs to the `D'
+ packet and `W' and `X' replies. Note that reporting this
+ feature indicates support for the syntactic extensions only,
+ not that the stub necessarily supports debugging of more than
+ one process at a time. The stub must not use multiprocess
+ extensions in packet replies unless GDB has also indicated it
+ supports them in its `qSupported' request.
+
+ `qXfer:osdata:read'
+ The remote stub understands the `qXfer:osdata:read' packet
+ ((*note qXfer osdata read::).
+
+ `ConditionalTracepoints'
+ The remote stub accepts and implements conditional
+ expressions defined for tracepoints (*note Tracepoint
+ Conditions::).
+
+ `ReverseContinue'
+ The remote stub accepts and implements the reverse continue
+ packet (*note bc::).
+
+ `ReverseStep'
+ The remote stub accepts and implements the reverse step packet
+ (*note bs::).
+
+ `TracepointSource'
+ The remote stub understands the `QTDPsrc' packet that supplies
+ the source form of tracepoint definitions.
+
+ `QAllow'
+ The remote stub understands the `QAllow' packet.
+
+ `QDisableRandomization'
+ The remote stub understands the `QDisableRandomization'
+ packet.
+
+ `StaticTracepoint'
+ The remote stub supports static tracepoints.
+
+ `InstallInTrace'
+ The remote stub supports installing tracepoint in tracing.
+
+ `EnableDisableTracepoints'
+ The remote stub supports the `QTEnable' (*note QTEnable::) and
+ `QTDisable' (*note QTDisable::) packets that allow tracepoints
+ to be enabled and disabled while a trace experiment is
+ running.
+
+ `tracenz'
+ The remote stub supports the `tracenz' bytecode for
+ collecting strings. See *Note Bytecode Descriptions:: for
+ details about the bytecode.
+
+
+`qSymbol::'
+ Notify the target that GDB is prepared to serve symbol lookup
+ requests. Accept requests from the target for the values of
+ symbols.
+
+ Reply:
+ `OK'
+ The target does not need to look up any (more) symbols.
+
+ `qSymbol:SYM_NAME'
+ The target requests the value of symbol SYM_NAME (hex
+ encoded). GDB may provide the value by using the
+ `qSymbol:SYM_VALUE:SYM_NAME' message, described below.
+
+`qSymbol:SYM_VALUE:SYM_NAME'
+ Set the value of SYM_NAME to SYM_VALUE.
+
+ SYM_NAME (hex encoded) is the name of a symbol whose value the
+ target has previously requested.
+
+ SYM_VALUE (hex) is the value for symbol SYM_NAME. If GDB cannot
+ supply a value for SYM_NAME, then this field will be empty.
+
+ Reply:
+ `OK'
+ The target does not need to look up any (more) symbols.
+
+ `qSymbol:SYM_NAME'
+ The target requests the value of a new symbol SYM_NAME (hex
+ encoded). GDB will continue to supply the values of symbols
+ (if available), until the target ceases to request them.
+
+`qTBuffer'
+
+`QTBuffer'
+
+`QTDisconnected'
+`QTDP'
+`QTDPsrc'
+`QTDV'
+`qTfP'
+`qTfV'
+`QTFrame'
+`qTMinFTPILen'
+ *Note Tracepoint Packets::.
+
+`qThreadExtraInfo,THREAD-ID'
+ Obtain a printable string description of a thread's attributes from
+ the target OS. THREAD-ID is a thread ID; see *Note thread-id
+ syntax::. This string may contain anything that the target OS
+ thinks is interesting for GDB to tell the user about the thread.
+ The string is displayed in GDB's `info threads' display. Some
+ examples of possible thread extra info strings are `Runnable', or
+ `Blocked on Mutex'.
+
+ Reply:
+ `XX...'
+ Where `XX...' is a hex encoding of ASCII data, comprising the
+ printable string containing the extra information about the
+ thread's attributes.
+
+ (Note that the `qThreadExtraInfo' packet's name is separated from
+ the command by a `,', not a `:', contrary to the naming
+ conventions above. Please don't use this packet as a model for new
+ packets.)
+
+`QTNotes'
+
+`qTP'
+
+`QTSave'
+
+`qTsP'
+
+`qTsV'
+`QTStart'
+`QTStop'
+`QTEnable'
+`QTDisable'
+`QTinit'
+`QTro'
+`qTStatus'
+`qTV'
+`qTfSTM'
+`qTsSTM'
+`qTSTMat'
+ *Note Tracepoint Packets::.
+
+`qXfer:OBJECT:read:ANNEX:OFFSET,LENGTH'
+ Read uninterpreted bytes from the target's special data area
+ identified by the keyword OBJECT. Request LENGTH bytes starting
+ at OFFSET bytes into the data. The content and encoding of ANNEX
+ is specific to OBJECT; it can supply additional details about what
+ data to access.
+
+ Here are the specific requests of this form defined so far. All
+ `qXfer:OBJECT:read:...' requests use the same reply formats,
+ listed below.
+
+ `qXfer:auxv:read::OFFSET,LENGTH'
+ Access the target's "auxiliary vector". *Note auxiliary
+ vector: OS Information. Note ANNEX must be empty.
+
+ This packet is not probed by default; the remote stub must
+ request it, by supplying an appropriate `qSupported' response
+ (*note qSupported::).
+
+ `qXfer:features:read:ANNEX:OFFSET,LENGTH'
+ Access the "target description". *Note Target
+ Descriptions::. The annex specifies which XML document to
+ access. The main description is always loaded from the
+ `target.xml' annex.
+
+ This packet is not probed by default; the remote stub must
+ request it, by supplying an appropriate `qSupported' response
+ (*note qSupported::).
+
+ `qXfer:libraries:read:ANNEX:OFFSET,LENGTH'
+ Access the target's list of loaded libraries. *Note Library
+ List Format::. The annex part of the generic `qXfer' packet
+ must be empty (*note qXfer read::).
+
+ Targets which maintain a list of libraries in the program's
+ memory do not need to implement this packet; it is designed
+ for platforms where the operating system manages the list of
+ loaded libraries.
+
+ This packet is not probed by default; the remote stub must
+ request it, by supplying an appropriate `qSupported' response
+ (*note qSupported::).
+
+ `qXfer:libraries-svr4:read:ANNEX:OFFSET,LENGTH'
+ Access the target's list of loaded libraries when the target
+ is an SVR4 platform. *Note Library List Format for SVR4
+ Targets::. The annex part of the generic `qXfer' packet must
+ be empty (*note qXfer read::).
+
+ This packet is optional for better performance on SVR4
+ targets. GDB uses memory read packets to read the SVR4
+ library list otherwise.
+
+ This packet is not probed by default; the remote stub must
+ request it, by supplying an appropriate `qSupported' response
+ (*note qSupported::).
+
+ `qXfer:memory-map:read::OFFSET,LENGTH'
+ Access the target's "memory-map". *Note Memory Map Format::.
+ The annex part of the generic `qXfer' packet must be empty
+ (*note qXfer read::).
+
+ This packet is not probed by default; the remote stub must
+ request it, by supplying an appropriate `qSupported' response
+ (*note qSupported::).
+
+ `qXfer:sdata:read::OFFSET,LENGTH'
+ Read contents of the extra collected static tracepoint marker
+ information. The annex part of the generic `qXfer' packet
+ must be empty (*note qXfer read::). *Note Tracepoint Action
+ Lists: Tracepoint Actions.
+
+ This packet is not probed by default; the remote stub must
+ request it, by supplying an appropriate `qSupported' response
+ (*note qSupported::).
+
+ `qXfer:siginfo:read::OFFSET,LENGTH'
+ Read contents of the extra signal information on the target
+ system. The annex part of the generic `qXfer' packet must be
+ empty (*note qXfer read::).
+
+ This packet is not probed by default; the remote stub must
+ request it, by supplying an appropriate `qSupported' response
+ (*note qSupported::).
+
+ `qXfer:spu:read:ANNEX:OFFSET,LENGTH'
+ Read contents of an `spufs' file on the target system. The
+ annex specifies which file to read; it must be of the form
+ `ID/NAME', where ID specifies an SPU context ID in the target
+ process, and NAME identifes the `spufs' file in that context
+ to be accessed.
+
+ This packet is not probed by default; the remote stub must
+ request it, by supplying an appropriate `qSupported' response
+ (*note qSupported::).
+
+ `qXfer:threads:read::OFFSET,LENGTH'
+ Access the list of threads on target. *Note Thread List
+ Format::. The annex part of the generic `qXfer' packet must
+ be empty (*note qXfer read::).
+
+ This packet is not probed by default; the remote stub must
+ request it, by supplying an appropriate `qSupported' response
+ (*note qSupported::).
+
+ `qXfer:traceframe-info:read::OFFSET,LENGTH'
+ Return a description of the current traceframe's contents.
+ *Note Traceframe Info Format::. The annex part of the generic
+ `qXfer' packet must be empty (*note qXfer read::).
+
+ This packet is not probed by default; the remote stub must
+ request it, by supplying an appropriate `qSupported' response
+ (*note qSupported::).
+
+ `qXfer:fdpic:read:ANNEX:OFFSET,LENGTH'
+ Read contents of `loadmap's on the target system. The annex,
+ either `exec' or `interp', specifies which `loadmap',
+ executable `loadmap' or interpreter `loadmap' to read.
+
+ This packet is not probed by default; the remote stub must
+ request it, by supplying an appropriate `qSupported' response
+ (*note qSupported::).
+
+ `qXfer:osdata:read::OFFSET,LENGTH'
+ Access the target's "operating system information". *Note
+ Operating System Information::.
+
+
+ Reply:
+ `m DATA'
+ Data DATA (*note Binary Data::) has been read from the
+ target. There may be more data at a higher address (although
+ it is permitted to return `m' even for the last valid block
+ of data, as long as at least one byte of data was read).
+ DATA may have fewer bytes than the LENGTH in the request.
+
+ `l DATA'
+ Data DATA (*note Binary Data::) has been read from the target.
+ There is no more data to be read. DATA may have fewer bytes
+ than the LENGTH in the request.
+
+ `l'
+ The OFFSET in the request is at the end of the data. There
+ is no more data to be read.
+
+ `E00'
+ The request was malformed, or ANNEX was invalid.
+
+ `E NN'
+ The offset was invalid, or there was an error encountered
+ reading the data. NN is a hex-encoded `errno' value.
+
+ `'
+ An empty reply indicates the OBJECT string was not recognized
+ by the stub, or that the object does not support reading.
+
+`qXfer:OBJECT:write:ANNEX:OFFSET:DATA...'
+ Write uninterpreted bytes into the target's special data area
+ identified by the keyword OBJECT, starting at OFFSET bytes into
+ the data. DATA... is the binary-encoded data (*note Binary
+ Data::) to be written. The content and encoding of ANNEX is
+ specific to OBJECT; it can supply additional details about what
+ data to access.
+
+ Here are the specific requests of this form defined so far. All
+ `qXfer:OBJECT:write:...' requests use the same reply formats,
+ listed below.
+
+ `qXfer:siginfo:write::OFFSET:DATA...'
+ Write DATA to the extra signal information on the target
+ system. The annex part of the generic `qXfer' packet must be
+ empty (*note qXfer write::).
+
+ This packet is not probed by default; the remote stub must
+ request it, by supplying an appropriate `qSupported' response
+ (*note qSupported::).
+
+ `qXfer:spu:write:ANNEX:OFFSET:DATA...'
+ Write DATA to an `spufs' file on the target system. The
+ annex specifies which file to write; it must be of the form
+ `ID/NAME', where ID specifies an SPU context ID in the target
+ process, and NAME identifes the `spufs' file in that context
+ to be accessed.
+
+ This packet is not probed by default; the remote stub must
+ request it, by supplying an appropriate `qSupported' response
+ (*note qSupported::).
+
+ Reply:
+ `NN'
+ NN (hex encoded) is the number of bytes written. This may be
+ fewer bytes than supplied in the request.
+
+ `E00'
+ The request was malformed, or ANNEX was invalid.
+
+ `E NN'
+ The offset was invalid, or there was an error encountered
+ writing the data. NN is a hex-encoded `errno' value.
+
+ `'
+ An empty reply indicates the OBJECT string was not recognized
+ by the stub, or that the object does not support writing.
+
+`qXfer:OBJECT:OPERATION:...'
+ Requests of this form may be added in the future. When a stub does
+ not recognize the OBJECT keyword, or its support for OBJECT does
+ not recognize the OPERATION keyword, the stub must respond with an
+ empty packet.
+
+`qAttached:PID'
+ Return an indication of whether the remote server attached to an
+ existing process or created a new process. When the multiprocess
+ protocol extensions are supported (*note multiprocess
+ extensions::), PID is an integer in hexadecimal format identifying
+ the target process. Otherwise, GDB will omit the PID field and
+ the query packet will be simplified as `qAttached'.
+
+ This query is used, for example, to know whether the remote process
+ should be detached or killed when a GDB session is ended with the
+ `quit' command.
+
+ Reply:
+ `1'
+ The remote server attached to an existing process.
+
+ `0'
+ The remote server created a new process.
+
+ `E NN'
+ A badly formed request or an error was encountered.
+
+
+ ---------- Footnotes ----------
+
+ (1) The `qP' and `qL' packets predate these conventions, and have
+arguments without any terminator for the packet name; we suspect they
+are in widespread use in places that are difficult to upgrade. The
+`qC' packet has no arguments, but some existing stubs (e.g. RedBoot)
+are known to not check for the end of the packet.
+
+
+File: gdb.info, Node: Architecture-Specific Protocol Details, Next: Tracepoint Packets, Prev: General Query Packets, Up: Remote Protocol
+
+E.5 Architecture-Specific Protocol Details
+==========================================
+
+This section describes how the remote protocol is applied to specific
+target architectures. Also see *Note Standard Target Features::, for
+details of XML target descriptions for each architecture.
+
+E.5.1 ARM
+---------
+
+E.5.1.1 Breakpoint Kinds
+........................
+
+These breakpoint kinds are defined for the `Z0' and `Z1' packets.
+
+2
+ 16-bit Thumb mode breakpoint.
+
+3
+ 32-bit Thumb mode (Thumb-2) breakpoint.
+
+4
+ 32-bit ARM mode breakpoint.
+
+
+E.5.2 MIPS
+----------
+
+E.5.2.1 Register Packet Format
+..............................
+
+The following `g'/`G' packets have previously been defined. In the
+below, some thirty-two bit registers are transferred as sixty-four
+bits. Those registers should be zero/sign extended (which?) to fill
+the space allocated. Register bytes are transferred in target byte
+order. The two nibbles within a register byte are transferred
+most-significant - least-significant.
+
+MIPS32
+ All registers are transferred as thirty-two bit quantities in the
+ order: 32 general-purpose; sr; lo; hi; bad; cause; pc; 32
+ floating-point registers; fsr; fir; fp.
+
+MIPS64
+ All registers are transferred as sixty-four bit quantities
+ (including thirty-two bit registers such as `sr'). The ordering
+ is the same as `MIPS32'.
+
+
+
+File: gdb.info, Node: Tracepoint Packets, Next: Host I/O Packets, Prev: Architecture-Specific Protocol Details, Up: Remote Protocol
+
+E.6 Tracepoint Packets
+======================
+
+Here we describe the packets GDB uses to implement tracepoints (*note
+Tracepoints::).
+
+`QTDP:N:ADDR:ENA:STEP:PASS[:FFLEN][:XLEN,BYTES][-]'
+ Create a new tracepoint, number N, at ADDR. If ENA is `E', then
+ the tracepoint is enabled; if it is `D', then the tracepoint is
+ disabled. STEP is the tracepoint's step count, and PASS is its
+ pass count. If an `F' is present, then the tracepoint is to be a
+ fast tracepoint, and the FLEN is the number of bytes that the
+ target should copy elsewhere to make room for the tracepoint. If
+ an `X' is present, it introduces a tracepoint condition, which
+ consists of a hexadecimal length, followed by a comma and
+ hex-encoded bytes, in a manner similar to action encodings as
+ described below. If the trailing `-' is present, further `QTDP'
+ packets will follow to specify this tracepoint's actions.
+
+ Replies:
+ `OK'
+ The packet was understood and carried out.
+
+ `qRelocInsn'
+ *Note Relocate instruction reply packet: Tracepoint Packets.
+
+ `'
+ The packet was not recognized.
+
+`QTDP:-N:ADDR:[S]ACTION...[-]'
+ Define actions to be taken when a tracepoint is hit. N and ADDR
+ must be the same as in the initial `QTDP' packet for this
+ tracepoint. This packet may only be sent immediately after
+ another `QTDP' packet that ended with a `-'. If the trailing `-'
+ is present, further `QTDP' packets will follow, specifying more
+ actions for this tracepoint.
+
+ In the series of action packets for a given tracepoint, at most one
+ can have an `S' before its first ACTION. If such a packet is
+ sent, it and the following packets define "while-stepping"
+ actions. Any prior packets define ordinary actions -- that is,
+ those taken when the tracepoint is first hit. If no action packet
+ has an `S', then all the packets in the series specify ordinary
+ tracepoint actions.
+
+ The `ACTION...' portion of the packet is a series of actions,
+ concatenated without separators. Each action has one of the
+ following forms:
+
+ `R MASK'
+ Collect the registers whose bits are set in MASK. MASK is a
+ hexadecimal number whose I'th bit is set if register number I
+ should be collected. (The least significant bit is numbered
+ zero.) Note that MASK may be any number of digits long; it
+ may not fit in a 32-bit word.
+
+ `M BASEREG,OFFSET,LEN'
+ Collect LEN bytes of memory starting at the address in
+ register number BASEREG, plus OFFSET. If BASEREG is `-1',
+ then the range has a fixed address: OFFSET is the address of
+ the lowest byte to collect. The BASEREG, OFFSET, and LEN
+ parameters are all unsigned hexadecimal values (the `-1'
+ value for BASEREG is a special case).
+
+ `X LEN,EXPR'
+ Evaluate EXPR, whose length is LEN, and collect memory as it
+ directs. EXPR is an agent expression, as described in *Note
+ Agent Expressions::. Each byte of the expression is encoded
+ as a two-digit hex number in the packet; LEN is the number of
+ bytes in the expression (and thus one-half the number of hex
+ digits in the packet).
+
+
+ Any number of actions may be packed together in a single `QTDP'
+ packet, as long as the packet does not exceed the maximum packet
+ length (400 bytes, for many stubs). There may be only one `R'
+ action per tracepoint, and it must precede any `M' or `X' actions.
+ Any registers referred to by `M' and `X' actions must be
+ collected by a preceding `R' action. (The "while-stepping"
+ actions are treated as if they were attached to a separate
+ tracepoint, as far as these restrictions are concerned.)
+
+ Replies:
+ `OK'
+ The packet was understood and carried out.
+
+ `qRelocInsn'
+ *Note Relocate instruction reply packet: Tracepoint Packets.
+
+ `'
+ The packet was not recognized.
+
+`QTDPsrc:N:ADDR:TYPE:START:SLEN:BYTES'
+ Specify a source string of tracepoint N at address ADDR. This is
+ useful to get accurate reproduction of the tracepoints originally
+ downloaded at the beginning of the trace run. TYPE is the name of
+ the tracepoint part, such as `cond' for the tracepoint's
+ conditional expression (see below for a list of types), while
+ BYTES is the string, encoded in hexadecimal.
+
+ START is the offset of the BYTES within the overall source string,
+ while SLEN is the total length of the source string. This is
+ intended for handling source strings that are longer than will fit
+ in a single packet.
+
+ The available string types are `at' for the location, `cond' for
+ the conditional, and `cmd' for an action command. GDB sends a
+ separate packet for each command in the action list, in the same
+ order in which the commands are stored in the list.
+
+ The target does not need to do anything with source strings except
+ report them back as part of the replies to the `qTfP'/`qTsP' query
+ packets.
+
+ Although this packet is optional, and GDB will only send it if the
+ target replies with `TracepointSource' *Note General Query
+ Packets::, it makes both disconnected tracing and trace files much
+ easier to use. Otherwise the user must be careful that the
+ tracepoints in effect while looking at trace frames are identical
+ to the ones in effect during the trace run; even a small
+ discrepancy could cause `tdump' not to work, or a particular trace
+ frame not be found.
+
+`QTDV:N:VALUE'
+ Create a new trace state variable, number N, with an initial value
+ of VALUE, which is a 64-bit signed integer. Both N and VALUE are
+ encoded as hexadecimal values. GDB has the option of not using
+ this packet for initial values of zero; the target should simply
+ create the trace state variables as they are mentioned in
+ expressions.
+
+`QTFrame:N'
+ Select the N'th tracepoint frame from the buffer, and use the
+ register and memory contents recorded there to answer subsequent
+ request packets from GDB.
+
+ A successful reply from the stub indicates that the stub has found
+ the requested frame. The response is a series of parts,
+ concatenated without separators, describing the frame we selected.
+ Each part has one of the following forms:
+
+ `F F'
+ The selected frame is number N in the trace frame buffer; F
+ is a hexadecimal number. If F is `-1', then there was no
+ frame matching the criteria in the request packet.
+
+ `T T'
+ The selected trace frame records a hit of tracepoint number T;
+ T is a hexadecimal number.
+
+
+`QTFrame:pc:ADDR'
+ Like `QTFrame:N', but select the first tracepoint frame after the
+ currently selected frame whose PC is ADDR; ADDR is a hexadecimal
+ number.
+
+`QTFrame:tdp:T'
+ Like `QTFrame:N', but select the first tracepoint frame after the
+ currently selected frame that is a hit of tracepoint T; T is a
+ hexadecimal number.
+
+`QTFrame:range:START:END'
+ Like `QTFrame:N', but select the first tracepoint frame after the
+ currently selected frame whose PC is between START (inclusive) and
+ END (inclusive); START and END are hexadecimal numbers.
+
+`QTFrame:outside:START:END'
+ Like `QTFrame:range:START:END', but select the first frame
+ _outside_ the given range of addresses (exclusive).
+
+`qTMinFTPILen'
+ This packet requests the minimum length of instruction at which a
+ fast tracepoint (*note Set Tracepoints::) may be placed. For
+ instance, on the 32-bit x86 architecture, it is possible to use a
+ 4-byte jump, but it depends on the target system being able to
+ create trampolines in the first 64K of memory, which might or
+ might not be possible for that system. So the reply to this
+ packet will be 4 if it is able to arrange for that.
+
+ Replies:
+
+ `0'
+ The minimum instruction length is currently unknown.
+
+ `LENGTH'
+ The minimum instruction length is LENGTH, where LENGTH is
+ greater or equal to 1. LENGTH is a hexadecimal number. A
+ reply of 1 means that a fast tracepoint may be placed on any
+ instruction regardless of size.
+
+ `E'
+ An error has occurred.
+
+ `'
+ An empty reply indicates that the request is not supported by
+ the stub.
+
+`QTStart'
+ Begin the tracepoint experiment. Begin collecting data from
+ tracepoint hits in the trace frame buffer. This packet supports
+ the `qRelocInsn' reply (*note Relocate instruction reply packet:
+ Tracepoint Packets.).
+
+`QTStop'
+ End the tracepoint experiment. Stop collecting trace frames.
+
+`QTEnable:N:ADDR'
+ Enable tracepoint N at address ADDR in a started tracepoint
+ experiment. If the tracepoint was previously disabled, then
+ collection of data from it will resume.
+
+`QTDisable:N:ADDR'
+ Disable tracepoint N at address ADDR in a started tracepoint
+ experiment. No more data will be collected from the tracepoint
+ unless `QTEnable:N:ADDR' is subsequently issued.
+
+`QTinit'
+ Clear the table of tracepoints, and empty the trace frame buffer.
+
+`QTro:START1,END1:START2,END2:...'
+ Establish the given ranges of memory as "transparent". The stub
+ will answer requests for these ranges from memory's current
+ contents, if they were not collected as part of the tracepoint hit.
+
+ GDB uses this to mark read-only regions of memory, like those
+ containing program code. Since these areas never change, they
+ should still have the same contents they did when the tracepoint
+ was hit, so there's no reason for the stub to refuse to provide
+ their contents.
+
+`QTDisconnected:VALUE'
+ Set the choice to what to do with the tracing run when GDB
+ disconnects from the target. A VALUE of 1 directs the target to
+ continue the tracing run, while 0 tells the target to stop tracing
+ if GDB is no longer in the picture.
+
+`qTStatus'
+ Ask the stub if there is a trace experiment running right now.
+
+ The reply has the form:
+
+ `TRUNNING[;FIELD]...'
+ RUNNING is a single digit `1' if the trace is presently
+ running, or `0' if not. It is followed by semicolon-separated
+ optional fields that an agent may use to report additional
+ status.
+
+
+ If the trace is not running, the agent may report any of several
+ explanations as one of the optional fields:
+
+ `tnotrun:0'
+ No trace has been run yet.
+
+ `tstop[:TEXT]:0'
+ The trace was stopped by a user-originated stop command. The
+ optional TEXT field is a user-supplied string supplied as
+ part of the stop command (for instance, an explanation of why
+ the trace was stopped manually). It is hex-encoded.
+
+ `tfull:0'
+ The trace stopped because the trace buffer filled up.
+
+ `tdisconnected:0'
+ The trace stopped because GDB disconnected from the target.
+
+ `tpasscount:TPNUM'
+ The trace stopped because tracepoint TPNUM exceeded its pass
+ count.
+
+ `terror:TEXT:TPNUM'
+ The trace stopped because tracepoint TPNUM had an error. The
+ string TEXT is available to describe the nature of the error
+ (for instance, a divide by zero in the condition expression).
+ TEXT is hex encoded.
+
+ `tunknown:0'
+ The trace stopped for some other reason.
+
+
+ Additional optional fields supply statistical and other
+ information. Although not required, they are extremely useful for
+ users monitoring the progress of a trace run. If a trace has
+ stopped, and these numbers are reported, they must reflect the
+ state of the just-stopped trace.
+
+ `tframes:N'
+ The number of trace frames in the buffer.
+
+ `tcreated:N'
+ The total number of trace frames created during the run. This
+ may be larger than the trace frame count, if the buffer is
+ circular.
+
+ `tsize:N'
+ The total size of the trace buffer, in bytes.
+
+ `tfree:N'
+ The number of bytes still unused in the buffer.
+
+ `circular:N'
+ The value of the circular trace buffer flag. `1' means that
+ the trace buffer is circular and old trace frames will be
+ discarded if necessary to make room, `0' means that the trace
+ buffer is linear and may fill up.
+
+ `disconn:N'
+ The value of the disconnected tracing flag. `1' means that
+ tracing will continue after GDB disconnects, `0' means that
+ the trace run will stop.
+
+
+`qTP:TP:ADDR'
+ Ask the stub for the current state of tracepoint number TP at
+ address ADDR.
+
+ Replies:
+ `VHITS:USAGE'
+ The tracepoint has been hit HITS times so far during the trace
+ run, and accounts for USAGE in the trace buffer. Note that
+ `while-stepping' steps are not counted as separate hits, but
+ the steps' space consumption is added into the usage number.
+
+
+`qTV:VAR'
+ Ask the stub for the value of the trace state variable number VAR.
+
+ Replies:
+ `VVALUE'
+ The value of the variable is VALUE. This will be the current
+ value of the variable if the user is examining a running
+ target, or a saved value if the variable was collected in the
+ trace frame that the user is looking at. Note that multiple
+ requests may result in different reply values, such as when
+ requesting values while the program is running.
+
+ `U'
+ The value of the variable is unknown. This would occur, for
+ example, if the user is examining a trace frame in which the
+ requested variable was not collected.
+
+`qTfP'
+`qTsP'
+ These packets request data about tracepoints that are being used by
+ the target. GDB sends `qTfP' to get the first piece of data, and
+ multiple `qTsP' to get additional pieces. Replies to these
+ packets generally take the form of the `QTDP' packets that define
+ tracepoints. (FIXME add detailed syntax)
+
+`qTfV'
+`qTsV'
+ These packets request data about trace state variables that are on
+ the target. GDB sends `qTfV' to get the first vari of data, and
+ multiple `qTsV' to get additional variables. Replies to these
+ packets follow the syntax of the `QTDV' packets that define trace
+ state variables.
+
+`qTfSTM'
+`qTsSTM'
+ These packets request data about static tracepoint markers that
+ exist in the target program. GDB sends `qTfSTM' to get the first
+ piece of data, and multiple `qTsSTM' to get additional pieces.
+ Replies to these packets take the following form:
+
+ Reply:
+ `m ADDRESS:ID:EXTRA'
+ A single marker
+
+ `m ADDRESS:ID:EXTRA,ADDRESS:ID:EXTRA...'
+ a comma-separated list of markers
+
+ `l'
+ (lower case letter `L') denotes end of list.
+
+ `E NN'
+ An error occurred. NN are hex digits.
+
+ `'
+ An empty reply indicates that the request is not supported by
+ the stub.
+
+ ADDRESS is encoded in hex. ID and EXTRA are strings encoded in
+ hex.
+
+ In response to each query, the target will reply with a list of
+ one or more markers, separated by commas. GDB will respond to each
+ reply with a request for more markers (using the `qs' form of the
+ query), until the target responds with `l' (lower-case ell, for
+ "last").
+
+`qTSTMat:ADDRESS'
+ This packets requests data about static tracepoint markers in the
+ target program at ADDRESS. Replies to this packet follow the
+ syntax of the `qTfSTM' and `qTsSTM' packets that list static
+ tracepoint markers.
+
+`QTSave:FILENAME'
+ This packet directs the target to save trace data to the file name
+ FILENAME in the target's filesystem. FILENAME is encoded as a hex
+ string; the interpretation of the file name (relative vs absolute,
+ wild cards, etc) is up to the target.
+
+`qTBuffer:OFFSET,LEN'
+ Return up to LEN bytes of the current contents of trace buffer,
+ starting at OFFSET. The trace buffer is treated as if it were a
+ contiguous collection of traceframes, as per the trace file format.
+ The reply consists as many hex-encoded bytes as the target can
+ deliver in a packet; it is not an error to return fewer than were
+ asked for. A reply consisting of just `l' indicates that no bytes
+ are available.
+
+`QTBuffer:circular:VALUE'
+ This packet directs the target to use a circular trace buffer if
+ VALUE is 1, or a linear buffer if the value is 0.
+
+`QTNotes:[TYPE:TEXT][;TYPE:TEXT]...'
+ This packet adds optional textual notes to the trace run.
+ Allowable types include `user', `notes', and `tstop', the TEXT
+ fields are arbitrary strings, hex-encoded.
+
+
+E.6.1 Relocate instruction reply packet
+---------------------------------------
+
+When installing fast tracepoints in memory, the target may need to
+relocate the instruction currently at the tracepoint address to a
+different address in memory. For most instructions, a simple copy is
+enough, but, for example, call instructions that implicitly push the
+return address on the stack, and relative branches or other PC-relative
+instructions require offset adjustment, so that the effect of executing
+the instruction at a different address is the same as if it had
+executed in the original location.
+
+ In response to several of the tracepoint packets, the target may also
+respond with a number of intermediate `qRelocInsn' request packets
+before the final result packet, to have GDB handle this relocation
+operation. If a packet supports this mechanism, its documentation will
+explicitly say so. See for example the above descriptions for the
+`QTStart' and `QTDP' packets. The format of the request is:
+
+`qRelocInsn:FROM;TO'
+ This requests GDB to copy instruction at address FROM to address
+ TO, possibly adjusted so that executing the instruction at TO has
+ the same effect as executing it at FROM. GDB writes the adjusted
+ instruction to target memory starting at TO.
+
+ Replies:
+`qRelocInsn:ADJUSTED_SIZE'
+ Informs the stub the relocation is complete. ADJUSTED_SIZE is the
+ length in bytes of resulting relocated instruction sequence.
+
+`E NN'
+ A badly formed request was detected, or an error was encountered
+ while relocating the instruction.
+
+
+File: gdb.info, Node: Host I/O Packets, Next: Interrupts, Prev: Tracepoint Packets, Up: Remote Protocol
+
+E.7 Host I/O Packets
+====================
+
+The "Host I/O" packets allow GDB to perform I/O operations on the far
+side of a remote link. For example, Host I/O is used to upload and
+download files to a remote target with its own filesystem. Host I/O
+uses the same constant values and data structure layout as the
+target-initiated File-I/O protocol. However, the Host I/O packets are
+structured differently. The target-initiated protocol relies on target
+memory to store parameters and buffers. Host I/O requests are
+initiated by GDB, and the target's memory is not involved. *Note
+File-I/O Remote Protocol Extension::, for more details on the
+target-initiated protocol.
+
+ The Host I/O request packets all encode a single operation along with
+its arguments. They have this format:
+
+`vFile:OPERATION: PARAMETER...'
+ OPERATION is the name of the particular request; the target should
+ compare the entire packet name up to the second colon when checking
+ for a supported operation. The format of PARAMETER depends on the
+ operation. Numbers are always passed in hexadecimal. Negative
+ numbers have an explicit minus sign (i.e. two's complement is not
+ used). Strings (e.g. filenames) are encoded as a series of
+ hexadecimal bytes. The last argument to a system call may be a
+ buffer of escaped binary data (*note Binary Data::).
+
+
+ The valid responses to Host I/O packets are:
+
+`F RESULT [, ERRNO] [; ATTACHMENT]'
+ RESULT is the integer value returned by this operation, usually
+ non-negative for success and -1 for errors. If an error has
+ occured, ERRNO will be included in the result. ERRNO will have a
+ value defined by the File-I/O protocol (*note Errno Values::). For
+ operations which return data, ATTACHMENT supplies the data as a
+ binary buffer. Binary buffers in response packets are escaped in
+ the normal way (*note Binary Data::). See the individual packet
+ documentation for the interpretation of RESULT and ATTACHMENT.
+
+`'
+ An empty response indicates that this operation is not recognized.
+
+
+ These are the supported Host I/O operations:
+
+`vFile:open: PATHNAME, FLAGS, MODE'
+ Open a file at PATHNAME and return a file descriptor for it, or
+ return -1 if an error occurs. PATHNAME is a string, FLAGS is an
+ integer indicating a mask of open flags (*note Open Flags::), and
+ MODE is an integer indicating a mask of mode bits to use if the
+ file is created (*note mode_t Values::). *Note open::, for
+ details of the open flags and mode values.
+
+`vFile:close: FD'
+ Close the open file corresponding to FD and return 0, or -1 if an
+ error occurs.
+
+`vFile:pread: FD, COUNT, OFFSET'
+ Read data from the open file corresponding to FD. Up to COUNT
+ bytes will be read from the file, starting at OFFSET relative to
+ the start of the file. The target may read fewer bytes; common
+ reasons include packet size limits and an end-of-file condition.
+ The number of bytes read is returned. Zero should only be
+ returned for a successful read at the end of the file, or if COUNT
+ was zero.
+
+ The data read should be returned as a binary attachment on success.
+ If zero bytes were read, the response should include an empty
+ binary attachment (i.e. a trailing semicolon). The return value
+ is the number of target bytes read; the binary attachment may be
+ longer if some characters were escaped.
+
+`vFile:pwrite: FD, OFFSET, DATA'
+ Write DATA (a binary buffer) to the open file corresponding to FD.
+ Start the write at OFFSET from the start of the file. Unlike
+ many `write' system calls, there is no separate COUNT argument;
+ the length of DATA in the packet is used. `vFile:write' returns
+ the number of bytes written, which may be shorter than the length
+ of DATA, or -1 if an error occurred.
+
+`vFile:unlink: PATHNAME'
+ Delete the file at PATHNAME on the target. Return 0, or -1 if an
+ error occurs. PATHNAME is a string.
+
+
+
+File: gdb.info, Node: Interrupts, Next: Notification Packets, Prev: Host I/O Packets, Up: Remote Protocol
+
+E.8 Interrupts
+==============
+
+When a program on the remote target is running, GDB may attempt to
+interrupt it by sending a `Ctrl-C', `BREAK' or a `BREAK' followed by
+`g', control of which is specified via GDB's `interrupt-sequence'.
+
+ The precise meaning of `BREAK' is defined by the transport mechanism
+and may, in fact, be undefined. GDB does not currently define a
+`BREAK' mechanism for any of the network interfaces except for TCP, in
+which case GDB sends the `telnet' BREAK sequence.
+
+ `Ctrl-C', on the other hand, is defined and implemented for all
+transport mechanisms. It is represented by sending the single byte
+`0x03' without any of the usual packet overhead described in the
+Overview section (*note Overview::). When a `0x03' byte is transmitted
+as part of a packet, it is considered to be packet data and does _not_
+represent an interrupt. E.g., an `X' packet (*note X packet::), used
+for binary downloads, may include an unescaped `0x03' as part of its
+packet.
+
+ `BREAK' followed by `g' is also known as Magic SysRq g. When Linux
+kernel receives this sequence from serial port, it stops execution and
+connects to gdb.
+
+ Stubs are not required to recognize these interrupt mechanisms and
+the precise meaning associated with receipt of the interrupt is
+implementation defined. If the target supports debugging of multiple
+threads and/or processes, it should attempt to interrupt all
+currently-executing threads and processes. If the stub is successful
+at interrupting the running program, it should send one of the stop
+reply packets (*note Stop Reply Packets::) to GDB as a result of
+successfully stopping the program in all-stop mode, and a stop reply
+for each stopped thread in non-stop mode. Interrupts received while the
+program is stopped are discarded.
+
+
+File: gdb.info, Node: Notification Packets, Next: Remote Non-Stop, Prev: Interrupts, Up: Remote Protocol
+
+E.9 Notification Packets
+========================
+
+The GDB remote serial protocol includes "notifications", packets that
+require no acknowledgment. Both the GDB and the stub may send
+notifications (although the only notifications defined at present are
+sent by the stub). Notifications carry information without incurring
+the round-trip latency of an acknowledgment, and so are useful for
+low-impact communications where occasional packet loss is not a problem.
+
+ A notification packet has the form `% DATA # CHECKSUM', where DATA
+is the content of the notification, and CHECKSUM is a checksum of DATA,
+computed and formatted as for ordinary GDB packets. A notification's
+DATA never contains `$', `%' or `#' characters. Upon receiving a
+notification, the recipient sends no `+' or `-' to acknowledge the
+notification's receipt or to report its corruption.
+
+ Every notification's DATA begins with a name, which contains no
+colon characters, followed by a colon character.
+
+ Recipients should silently ignore corrupted notifications and
+notifications they do not understand. Recipients should restart
+timeout periods on receipt of a well-formed notification, whether or
+not they understand it.
+
+ Senders should only send the notifications described here when this
+protocol description specifies that they are permitted. In the future,
+we may extend the protocol to permit existing notifications in new
+contexts; this rule helps older senders avoid confusing newer
+recipients.
+
+ (Older versions of GDB ignore bytes received until they see the `$'
+byte that begins an ordinary packet, so new stubs may transmit
+notifications without fear of confusing older clients. There are no
+notifications defined for GDB to send at the moment, but we assume that
+most older stubs would ignore them, as well.)
+
+ The following notification packets from the stub to GDB are defined:
+
+`Stop: REPLY'
+ Report an asynchronous stop event in non-stop mode. The REPLY has
+ the form of a stop reply, as described in *Note Stop Reply
+ Packets::. Refer to *Note Remote Non-Stop::, for information on
+ how these notifications are acknowledged by GDB.
+
+
+File: gdb.info, Node: Remote Non-Stop, Next: Packet Acknowledgment, Prev: Notification Packets, Up: Remote Protocol
+
+E.10 Remote Protocol Support for Non-Stop Mode
+==============================================
+
+GDB's remote protocol supports non-stop debugging of multi-threaded
+programs, as described in *Note Non-Stop Mode::. If the stub supports
+non-stop mode, it should report that to GDB by including `QNonStop+' in
+its `qSupported' response (*note qSupported::).
+
+ GDB typically sends a `QNonStop' packet only when establishing a new
+connection with the stub. Entering non-stop mode does not alter the
+state of any currently-running threads, but targets must stop all
+threads in any already-attached processes when entering all-stop mode.
+GDB uses the `?' packet as necessary to probe the target state after a
+mode change.
+
+ In non-stop mode, when an attached process encounters an event that
+would otherwise be reported with a stop reply, it uses the asynchronous
+notification mechanism (*note Notification Packets::) to inform GDB.
+In contrast to all-stop mode, where all threads in all processes are
+stopped when a stop reply is sent, in non-stop mode only the thread
+reporting the stop event is stopped. That is, when reporting a `S' or
+`T' response to indicate completion of a step operation, hitting a
+breakpoint, or a fault, only the affected thread is stopped; any other
+still-running threads continue to run. When reporting a `W' or `X'
+response, all running threads belonging to other attached processes
+continue to run.
+
+ Only one stop reply notification at a time may be pending; if
+additional stop events occur before GDB has acknowledged the previous
+notification, they must be queued by the stub for later synchronous
+transmission in response to `vStopped' packets from GDB. Because the
+notification mechanism is unreliable, the stub is permitted to resend a
+stop reply notification if it believes GDB may not have received it.
+GDB ignores additional stop reply notifications received before it has
+finished processing a previous notification and the stub has completed
+sending any queued stop events.
+
+ Otherwise, GDB must be prepared to receive a stop reply notification
+at any time. Specifically, they may appear when GDB is not otherwise
+reading input from the stub, or when GDB is expecting to read a normal
+synchronous response or a `+'/`-' acknowledgment to a packet it has
+sent. Notification packets are distinct from any other communication
+from the stub so there is no ambiguity.
+
+ After receiving a stop reply notification, GDB shall acknowledge it
+by sending a `vStopped' packet (*note vStopped packet::) as a regular,
+synchronous request to the stub. Such acknowledgment is not required
+to happen immediately, as GDB is permitted to send other, unrelated
+packets to the stub first, which the stub should process normally.
+
+ Upon receiving a `vStopped' packet, if the stub has other queued
+stop events to report to GDB, it shall respond by sending a normal stop
+reply response. GDB shall then send another `vStopped' packet to
+solicit further responses; again, it is permitted to send other,
+unrelated packets as well which the stub should process normally.
+
+ If the stub receives a `vStopped' packet and there are no additional
+stop events to report, the stub shall return an `OK' response. At this
+point, if further stop events occur, the stub shall send a new stop
+reply notification, GDB shall accept the notification, and the process
+shall be repeated.
+
+ In non-stop mode, the target shall respond to the `?' packet as
+follows. First, any incomplete stop reply notification/`vStopped'
+sequence in progress is abandoned. The target must begin a new
+sequence reporting stop events for all stopped threads, whether or not
+it has previously reported those events to GDB. The first stop reply
+is sent as a synchronous reply to the `?' packet, and subsequent stop
+replies are sent as responses to `vStopped' packets using the mechanism
+described above. The target must not send asynchronous stop reply
+notifications until the sequence is complete. If all threads are
+running when the target receives the `?' packet, or if the target is
+not attached to any process, it shall respond `OK'.
+
+
+File: gdb.info, Node: Packet Acknowledgment, Next: Examples, Prev: Remote Non-Stop, Up: Remote Protocol
+
+E.11 Packet Acknowledgment
+==========================
+
+By default, when either the host or the target machine receives a
+packet, the first response expected is an acknowledgment: either `+'
+(to indicate the package was received correctly) or `-' (to request
+retransmission). This mechanism allows the GDB remote protocol to
+operate over unreliable transport mechanisms, such as a serial line.
+
+ In cases where the transport mechanism is itself reliable (such as a
+pipe or TCP connection), the `+'/`-' acknowledgments are redundant. It
+may be desirable to disable them in that case to reduce communication
+overhead, or for other reasons. This can be accomplished by means of
+the `QStartNoAckMode' packet; *note QStartNoAckMode::.
+
+ When in no-acknowledgment mode, neither the stub nor GDB shall send
+or expect `+'/`-' protocol acknowledgments. The packet and response
+format still includes the normal checksum, as described in *Note
+Overview::, but the checksum may be ignored by the receiver.
+
+ If the stub supports `QStartNoAckMode' and prefers to operate in
+no-acknowledgment mode, it should report that to GDB by including
+`QStartNoAckMode+' in its response to `qSupported'; *note qSupported::.
+If GDB also supports `QStartNoAckMode' and it has not been disabled via
+the `set remote noack-packet off' command (*note Remote
+Configuration::), GDB may then send a `QStartNoAckMode' packet to the
+stub. Only then may the stub actually turn off packet acknowledgments.
+GDB sends a final `+' acknowledgment of the stub's `OK' response, which
+can be safely ignored by the stub.
+
+ Note that `set remote noack-packet' command only affects negotiation
+between GDB and the stub when subsequent connections are made; it does
+not affect the protocol acknowledgment state for any current connection.
+Since `+'/`-' acknowledgments are enabled by default when a new
+connection is established, there is also no protocol request to
+re-enable the acknowledgments for the current connection, once disabled.
+
+
+File: gdb.info, Node: Examples, Next: File-I/O Remote Protocol Extension, Prev: Packet Acknowledgment, Up: Remote Protocol
+
+E.12 Examples
+=============
+
+Example sequence of a target being re-started. Notice how the restart
+does not get any direct output:
+
+ -> `R00'
+ <- `+'
+ _target restarts_
+ -> `?'
+ <- `+'
+ <- `T001:1234123412341234'
+ -> `+'
+
+ Example sequence of a target being stepped by a single instruction:
+
+ -> `G1445...'
+ <- `+'
+ -> `s'
+ <- `+'
+ _time passes_
+ <- `T001:1234123412341234'
+ -> `+'
+ -> `g'
+ <- `+'
+ <- `1455...'
+ -> `+'
+
+
+File: gdb.info, Node: File-I/O Remote Protocol Extension, Next: Library List Format, Prev: Examples, Up: Remote Protocol
+
+E.13 File-I/O Remote Protocol Extension
+=======================================
+
+* Menu:
+
+* File-I/O Overview::
+* Protocol Basics::
+* The F Request Packet::
+* The F Reply Packet::
+* The Ctrl-C Message::
+* Console I/O::
+* List of Supported Calls::
+* Protocol-specific Representation of Datatypes::
+* Constants::
+* File-I/O Examples::
+
+
+File: gdb.info, Node: File-I/O Overview, Next: Protocol Basics, Up: File-I/O Remote Protocol Extension
+
+E.13.1 File-I/O Overview
+------------------------
+
+The "File I/O remote protocol extension" (short: File-I/O) allows the
+target to use the host's file system and console I/O to perform various
+system calls. System calls on the target system are translated into a
+remote protocol packet to the host system, which then performs the
+needed actions and returns a response packet to the target system.
+This simulates file system operations even on targets that lack file
+systems.
+
+ The protocol is defined to be independent of both the host and
+target systems. It uses its own internal representation of datatypes
+and values. Both GDB and the target's GDB stub are responsible for
+translating the system-dependent value representations into the internal
+protocol representations when data is transmitted.
+
+ The communication is synchronous. A system call is possible only
+when GDB is waiting for a response from the `C', `c', `S' or `s'
+packets. While GDB handles the request for a system call, the target
+is stopped to allow deterministic access to the target's memory.
+Therefore File-I/O is not interruptible by target signals. On the
+other hand, it is possible to interrupt File-I/O by a user interrupt
+(`Ctrl-C') within GDB.
+
+ The target's request to perform a host system call does not finish
+the latest `C', `c', `S' or `s' action. That means, after finishing
+the system call, the target returns to continuing the previous activity
+(continue, step). No additional continue or step request from GDB is
+required.
+
+ (gdb) continue
+ <- target requests 'system call X'
+ target is stopped, GDB executes system call
+ -> GDB returns result
+ ... target continues, GDB returns to wait for the target
+ <- target hits breakpoint and sends a Txx packet
+
+ The protocol only supports I/O on the console and to regular files on
+the host file system. Character or block special devices, pipes, named
+pipes, sockets or any other communication method on the host system are
+not supported by this protocol.
+
+ File I/O is not supported in non-stop mode.
+
+
+File: gdb.info, Node: Protocol Basics, Next: The F Request Packet, Prev: File-I/O Overview, Up: File-I/O Remote Protocol Extension
+
+E.13.2 Protocol Basics
+----------------------
+
+The File-I/O protocol uses the `F' packet as the request as well as
+reply packet. Since a File-I/O system call can only occur when GDB is
+waiting for a response from the continuing or stepping target, the
+File-I/O request is a reply that GDB has to expect as a result of a
+previous `C', `c', `S' or `s' packet. This `F' packet contains all
+information needed to allow GDB to call the appropriate host system
+call:
+
+ * A unique identifier for the requested system call.
+
+ * All parameters to the system call. Pointers are given as addresses
+ in the target memory address space. Pointers to strings are given
+ as pointer/length pair. Numerical values are given as they are.
+ Numerical control flags are given in a protocol-specific
+ representation.
+
+
+ At this point, GDB has to perform the following actions.
+
+ * If the parameters include pointer values to data needed as input
+ to a system call, GDB requests this data from the target with a
+ standard `m' packet request. This additional communication has to
+ be expected by the target implementation and is handled as any
+ other `m' packet.
+
+ * GDB translates all value from protocol representation to host
+ representation as needed. Datatypes are coerced into the host
+ types.
+
+ * GDB calls the system call.
+
+ * It then coerces datatypes back to protocol representation.
+
+ * If the system call is expected to return data in buffer space
+ specified by pointer parameters to the call, the data is
+ transmitted to the target using a `M' or `X' packet. This packet
+ has to be expected by the target implementation and is handled as
+ any other `M' or `X' packet.
+
+
+ Eventually GDB replies with another `F' packet which contains all
+necessary information for the target to continue. This at least
+contains
+
+ * Return value.
+
+ * `errno', if has been changed by the system call.
+
+ * "Ctrl-C" flag.
+
+
+ After having done the needed type and value coercion, the target
+continues the latest continue or step action.
+
+
+File: gdb.info, Node: The F Request Packet, Next: The F Reply Packet, Prev: Protocol Basics, Up: File-I/O Remote Protocol Extension
+
+E.13.3 The `F' Request Packet
+-----------------------------
+
+The `F' request packet has the following format:
+
+`FCALL-ID,PARAMETER...'
+ CALL-ID is the identifier to indicate the host system call to be
+ called. This is just the name of the function.
+
+ PARAMETER... are the parameters to the system call. Parameters
+ are hexadecimal integer values, either the actual values in case
+ of scalar datatypes, pointers to target buffer space in case of
+ compound datatypes and unspecified memory areas, or pointer/length
+ pairs in case of string parameters. These are appended to the
+ CALL-ID as a comma-delimited list. All values are transmitted in
+ ASCII string representation, pointer/length pairs separated by a
+ slash.
+
+
+
+File: gdb.info, Node: The F Reply Packet, Next: The Ctrl-C Message, Prev: The F Request Packet, Up: File-I/O Remote Protocol Extension
+
+E.13.4 The `F' Reply Packet
+---------------------------
+
+The `F' reply packet has the following format:
+
+`FRETCODE,ERRNO,CTRL-C FLAG;CALL-SPECIFIC ATTACHMENT'
+ RETCODE is the return code of the system call as hexadecimal value.
+
+ ERRNO is the `errno' set by the call, in protocol-specific
+ representation. This parameter can be omitted if the call was
+ successful.
+
+ CTRL-C FLAG is only sent if the user requested a break. In this
+ case, ERRNO must be sent as well, even if the call was successful.
+ The CTRL-C FLAG itself consists of the character `C':
+
+ F0,0,C
+
+ or, if the call was interrupted before the host call has been
+ performed:
+
+ F-1,4,C
+
+ assuming 4 is the protocol-specific representation of `EINTR'.
+
+
+
+File: gdb.info, Node: The Ctrl-C Message, Next: Console I/O, Prev: The F Reply Packet, Up: File-I/O Remote Protocol Extension
+
+E.13.5 The `Ctrl-C' Message
+---------------------------
+
+If the `Ctrl-C' flag is set in the GDB reply packet (*note The F Reply
+Packet::), the target should behave as if it had gotten a break
+message. The meaning for the target is "system call interrupted by
+`SIGINT'". Consequentially, the target should actually stop (as with a
+break message) and return to GDB with a `T02' packet.
+
+ It's important for the target to know in which state the system call
+was interrupted. There are two possible cases:
+
+ * The system call hasn't been performed on the host yet.
+
+ * The system call on the host has been finished.
+
+
+ These two states can be distinguished by the target by the value of
+the returned `errno'. If it's the protocol representation of `EINTR',
+the system call hasn't been performed. This is equivalent to the
+`EINTR' handling on POSIX systems. In any other case, the target may
+presume that the system call has been finished -- successfully or not
+-- and should behave as if the break message arrived right after the
+system call.
+
+ GDB must behave reliably. If the system call has not been called
+yet, GDB may send the `F' reply immediately, setting `EINTR' as `errno'
+in the packet. If the system call on the host has been finished before
+the user requests a break, the full action must be finished by GDB.
+This requires sending `M' or `X' packets as necessary. The `F' packet
+may only be sent when either nothing has happened or the full action
+has been completed.
+
+
+File: gdb.info, Node: Console I/O, Next: List of Supported Calls, Prev: The Ctrl-C Message, Up: File-I/O Remote Protocol Extension
+
+E.13.6 Console I/O
+------------------
+
+By default and if not explicitly closed by the target system, the file
+descriptors 0, 1 and 2 are connected to the GDB console. Output on the
+GDB console is handled as any other file output operation (`write(1,
+...)' or `write(2, ...)'). Console input is handled by GDB so that
+after the target read request from file descriptor 0 all following
+typing is buffered until either one of the following conditions is met:
+
+ * The user types `Ctrl-c'. The behaviour is as explained above, and
+ the `read' system call is treated as finished.
+
+ * The user presses <RET>. This is treated as end of input with a
+ trailing newline.
+
+ * The user types `Ctrl-d'. This is treated as end of input. No
+ trailing character (neither newline nor `Ctrl-D') is appended to
+ the input.
+
+
+ If the user has typed more characters than fit in the buffer given to
+the `read' call, the trailing characters are buffered in GDB until
+either another `read(0, ...)' is requested by the target, or debugging
+is stopped at the user's request.
+
+
+File: gdb.info, Node: List of Supported Calls, Next: Protocol-specific Representation of Datatypes, Prev: Console I/O, Up: File-I/O Remote Protocol Extension
+
+E.13.7 List of Supported Calls
+------------------------------
+
+* Menu:
+
+* open::
+* close::
+* read::
+* write::
+* lseek::
+* rename::
+* unlink::
+* stat/fstat::
+* gettimeofday::
+* isatty::
+* system::
+
+
+File: gdb.info, Node: open, Next: close, Up: List of Supported Calls
+
+open
+....
+
+Synopsis:
+ int open(const char *pathname, int flags);
+ int open(const char *pathname, int flags, mode_t mode);
+
+Request:
+ `Fopen,PATHPTR/LEN,FLAGS,MODE'
+
+ FLAGS is the bitwise `OR' of the following values:
+
+ `O_CREAT'
+ If the file does not exist it will be created. The host
+ rules apply as far as file ownership and time stamps are
+ concerned.
+
+ `O_EXCL'
+ When used with `O_CREAT', if the file already exists it is an
+ error and open() fails.
+
+ `O_TRUNC'
+ If the file already exists and the open mode allows writing
+ (`O_RDWR' or `O_WRONLY' is given) it will be truncated to
+ zero length.
+
+ `O_APPEND'
+ The file is opened in append mode.
+
+ `O_RDONLY'
+ The file is opened for reading only.
+
+ `O_WRONLY'
+ The file is opened for writing only.
+
+ `O_RDWR'
+ The file is opened for reading and writing.
+
+ Other bits are silently ignored.
+
+ MODE is the bitwise `OR' of the following values:
+
+ `S_IRUSR'
+ User has read permission.
+
+ `S_IWUSR'
+ User has write permission.
+
+ `S_IRGRP'
+ Group has read permission.
+
+ `S_IWGRP'
+ Group has write permission.
+
+ `S_IROTH'
+ Others have read permission.
+
+ `S_IWOTH'
+ Others have write permission.
+
+ Other bits are silently ignored.
+
+Return value:
+ `open' returns the new file descriptor or -1 if an error occurred.
+
+Errors:
+
+ `EEXIST'
+ PATHNAME already exists and `O_CREAT' and `O_EXCL' were used.
+
+ `EISDIR'
+ PATHNAME refers to a directory.
+
+ `EACCES'
+ The requested access is not allowed.
+
+ `ENAMETOOLONG'
+ PATHNAME was too long.
+
+ `ENOENT'
+ A directory component in PATHNAME does not exist.
+
+ `ENODEV'
+ PATHNAME refers to a device, pipe, named pipe or socket.
+
+ `EROFS'
+ PATHNAME refers to a file on a read-only filesystem and write
+ access was requested.
+
+ `EFAULT'
+ PATHNAME is an invalid pointer value.
+
+ `ENOSPC'
+ No space on device to create the file.
+
+ `EMFILE'
+ The process already has the maximum number of files open.
+
+ `ENFILE'
+ The limit on the total number of files open on the system has
+ been reached.
+
+ `EINTR'
+ The call was interrupted by the user.
+
+
+
+File: gdb.info, Node: close, Next: read, Prev: open, Up: List of Supported Calls
+
+close
+.....
+
+Synopsis:
+ int close(int fd);
+
+Request:
+ `Fclose,FD'
+
+Return value:
+ `close' returns zero on success, or -1 if an error occurred.
+
+Errors:
+
+ `EBADF'
+ FD isn't a valid open file descriptor.
+
+ `EINTR'
+ The call was interrupted by the user.
+
+
+
+File: gdb.info, Node: read, Next: write, Prev: close, Up: List of Supported Calls
+
+read
+....
+
+Synopsis:
+ int read(int fd, void *buf, unsigned int count);
+
+Request:
+ `Fread,FD,BUFPTR,COUNT'
+
+Return value:
+ On success, the number of bytes read is returned. Zero indicates
+ end of file. If count is zero, read returns zero as well. On
+ error, -1 is returned.
+
+Errors:
+
+ `EBADF'
+ FD is not a valid file descriptor or is not open for reading.
+
+ `EFAULT'
+ BUFPTR is an invalid pointer value.
+
+ `EINTR'
+ The call was interrupted by the user.
+
+
+
+File: gdb.info, Node: write, Next: lseek, Prev: read, Up: List of Supported Calls
+
+write
+.....
+
+Synopsis:
+ int write(int fd, const void *buf, unsigned int count);
+
+Request:
+ `Fwrite,FD,BUFPTR,COUNT'
+
+Return value:
+ On success, the number of bytes written are returned. Zero
+ indicates nothing was written. On error, -1 is returned.
+
+Errors:
+
+ `EBADF'
+ FD is not a valid file descriptor or is not open for writing.
+
+ `EFAULT'
+ BUFPTR is an invalid pointer value.
+
+ `EFBIG'
+ An attempt was made to write a file that exceeds the
+ host-specific maximum file size allowed.
+
+ `ENOSPC'
+ No space on device to write the data.
+
+ `EINTR'
+ The call was interrupted by the user.
+
+
+
+File: gdb.info, Node: lseek, Next: rename, Prev: write, Up: List of Supported Calls
+
+lseek
+.....
+
+Synopsis:
+ long lseek (int fd, long offset, int flag);
+
+Request:
+ `Flseek,FD,OFFSET,FLAG'
+
+ FLAG is one of:
+
+ `SEEK_SET'
+ The offset is set to OFFSET bytes.
+
+ `SEEK_CUR'
+ The offset is set to its current location plus OFFSET bytes.
+
+ `SEEK_END'
+ The offset is set to the size of the file plus OFFSET bytes.
+
+Return value:
+ On success, the resulting unsigned offset in bytes from the
+ beginning of the file is returned. Otherwise, a value of -1 is
+ returned.
+
+Errors:
+
+ `EBADF'
+ FD is not a valid open file descriptor.
+
+ `ESPIPE'
+ FD is associated with the GDB console.
+
+ `EINVAL'
+ FLAG is not a proper value.
+
+ `EINTR'
+ The call was interrupted by the user.
+
+
+
+File: gdb.info, Node: rename, Next: unlink, Prev: lseek, Up: List of Supported Calls
+
+rename
+......
+
+Synopsis:
+ int rename(const char *oldpath, const char *newpath);
+
+Request:
+ `Frename,OLDPATHPTR/LEN,NEWPATHPTR/LEN'
+
+Return value:
+ On success, zero is returned. On error, -1 is returned.
+
+Errors:
+
+ `EISDIR'
+ NEWPATH is an existing directory, but OLDPATH is not a
+ directory.
+
+ `EEXIST'
+ NEWPATH is a non-empty directory.
+
+ `EBUSY'
+ OLDPATH or NEWPATH is a directory that is in use by some
+ process.
+
+ `EINVAL'
+ An attempt was made to make a directory a subdirectory of
+ itself.
+
+ `ENOTDIR'
+ A component used as a directory in OLDPATH or new path is
+ not a directory. Or OLDPATH is a directory and NEWPATH
+ exists but is not a directory.
+
+ `EFAULT'
+ OLDPATHPTR or NEWPATHPTR are invalid pointer values.
+
+ `EACCES'
+ No access to the file or the path of the file.
+
+ `ENAMETOOLONG'
+ OLDPATH or NEWPATH was too long.
+
+ `ENOENT'
+ A directory component in OLDPATH or NEWPATH does not exist.
+
+ `EROFS'
+ The file is on a read-only filesystem.
+
+ `ENOSPC'
+ The device containing the file has no room for the new
+ directory entry.
+
+ `EINTR'
+ The call was interrupted by the user.
+
+
+
+File: gdb.info, Node: unlink, Next: stat/fstat, Prev: rename, Up: List of Supported Calls
+
+unlink
+......
+
+Synopsis:
+ int unlink(const char *pathname);
+
+Request:
+ `Funlink,PATHNAMEPTR/LEN'
+
+Return value:
+ On success, zero is returned. On error, -1 is returned.
+
+Errors:
+
+ `EACCES'
+ No access to the file or the path of the file.
+
+ `EPERM'
+ The system does not allow unlinking of directories.
+
+ `EBUSY'
+ The file PATHNAME cannot be unlinked because it's being used
+ by another process.
+
+ `EFAULT'
+ PATHNAMEPTR is an invalid pointer value.
+
+ `ENAMETOOLONG'
+ PATHNAME was too long.
+
+ `ENOENT'
+ A directory component in PATHNAME does not exist.
+
+ `ENOTDIR'
+ A component of the path is not a directory.
+
+ `EROFS'
+ The file is on a read-only filesystem.
+
+ `EINTR'
+ The call was interrupted by the user.
+
+
+
+File: gdb.info, Node: stat/fstat, Next: gettimeofday, Prev: unlink, Up: List of Supported Calls
+
+stat/fstat
+..........
+
+Synopsis:
+ int stat(const char *pathname, struct stat *buf);
+ int fstat(int fd, struct stat *buf);
+
+Request:
+ `Fstat,PATHNAMEPTR/LEN,BUFPTR'
+ `Ffstat,FD,BUFPTR'
+
+Return value:
+ On success, zero is returned. On error, -1 is returned.
+
+Errors:
+
+ `EBADF'
+ FD is not a valid open file.
+
+ `ENOENT'
+ A directory component in PATHNAME does not exist or the path
+ is an empty string.
+
+ `ENOTDIR'
+ A component of the path is not a directory.
+
+ `EFAULT'
+ PATHNAMEPTR is an invalid pointer value.
+
+ `EACCES'
+ No access to the file or the path of the file.
+
+ `ENAMETOOLONG'
+ PATHNAME was too long.
+
+ `EINTR'
+ The call was interrupted by the user.
+
+
+
+File: gdb.info, Node: gettimeofday, Next: isatty, Prev: stat/fstat, Up: List of Supported Calls
+
+gettimeofday
+............
+
+Synopsis:
+ int gettimeofday(struct timeval *tv, void *tz);
+
+Request:
+ `Fgettimeofday,TVPTR,TZPTR'
+
+Return value:
+ On success, 0 is returned, -1 otherwise.
+
+Errors:
+
+ `EINVAL'
+ TZ is a non-NULL pointer.
+
+ `EFAULT'
+ TVPTR and/or TZPTR is an invalid pointer value.
+
+
+
+File: gdb.info, Node: isatty, Next: system, Prev: gettimeofday, Up: List of Supported Calls
+
+isatty
+......
+
+Synopsis:
+ int isatty(int fd);
+
+Request:
+ `Fisatty,FD'
+
+Return value:
+ Returns 1 if FD refers to the GDB console, 0 otherwise.
+
+Errors:
+
+ `EINTR'
+ The call was interrupted by the user.
+
+
+ Note that the `isatty' call is treated as a special case: it returns
+1 to the target if the file descriptor is attached to the GDB console,
+0 otherwise. Implementing through system calls would require
+implementing `ioctl' and would be more complex than needed.
+
+
+File: gdb.info, Node: system, Prev: isatty, Up: List of Supported Calls
+
+system
+......
+
+Synopsis:
+ int system(const char *command);
+
+Request:
+ `Fsystem,COMMANDPTR/LEN'
+
+Return value:
+ If LEN is zero, the return value indicates whether a shell is
+ available. A zero return value indicates a shell is not available.
+ For non-zero LEN, the value returned is -1 on error and the return
+ status of the command otherwise. Only the exit status of the
+ command is returned, which is extracted from the host's `system'
+ return value by calling `WEXITSTATUS(retval)'. In case `/bin/sh'
+ could not be executed, 127 is returned.
+
+Errors:
+
+ `EINTR'
+ The call was interrupted by the user.
+
+
+ GDB takes over the full task of calling the necessary host calls to
+perform the `system' call. The return value of `system' on the host is
+simplified before it's returned to the target. Any termination signal
+information from the child process is discarded, and the return value
+consists entirely of the exit status of the called command.
+
+ Due to security concerns, the `system' call is by default refused by
+GDB. The user has to allow this call explicitly with the `set remote
+system-call-allowed 1' command.
+
+`set remote system-call-allowed'
+ Control whether to allow the `system' calls in the File I/O
+ protocol for the remote target. The default is zero (disabled).
+
+`show remote system-call-allowed'
+ Show whether the `system' calls are allowed in the File I/O
+ protocol.
+
+
+File: gdb.info, Node: Protocol-specific Representation of Datatypes, Next: Constants, Prev: List of Supported Calls, Up: File-I/O Remote Protocol Extension
+
+E.13.8 Protocol-specific Representation of Datatypes
+----------------------------------------------------
+
+* Menu:
+
+* Integral Datatypes::
+* Pointer Values::
+* Memory Transfer::
+* struct stat::
+* struct timeval::
+
+
+File: gdb.info, Node: Integral Datatypes, Next: Pointer Values, Up: Protocol-specific Representation of Datatypes
+
+Integral Datatypes
+..................
+
+The integral datatypes used in the system calls are `int', `unsigned
+int', `long', `unsigned long', `mode_t', and `time_t'.
+
+ `int', `unsigned int', `mode_t' and `time_t' are implemented as 32
+bit values in this protocol.
+
+ `long' and `unsigned long' are implemented as 64 bit types.
+
+ *Note Limits::, for corresponding MIN and MAX values (similar to
+those in `limits.h') to allow range checking on host and target.
+
+ `time_t' datatypes are defined as seconds since the Epoch.
+
+ All integral datatypes transferred as part of a memory read or write
+of a structured datatype e.g. a `struct stat' have to be given in big
+endian byte order.
+
+
+File: gdb.info, Node: Pointer Values, Next: Memory Transfer, Prev: Integral Datatypes, Up: Protocol-specific Representation of Datatypes
+
+Pointer Values
+..............
+
+Pointers to target data are transmitted as they are. An exception is
+made for pointers to buffers for which the length isn't transmitted as
+part of the function call, namely strings. Strings are transmitted as
+a pointer/length pair, both as hex values, e.g.
+
+ `1aaf/12'
+
+which is a pointer to data of length 18 bytes at position 0x1aaf. The
+length is defined as the full string length in bytes, including the
+trailing null byte. For example, the string `"hello world"' at address
+0x123456 is transmitted as
+
+ `123456/d'
+
+
+File: gdb.info, Node: Memory Transfer, Next: struct stat, Prev: Pointer Values, Up: Protocol-specific Representation of Datatypes
+
+Memory Transfer
+...............
+
+Structured data which is transferred using a memory read or write (for
+example, a `struct stat') is expected to be in a protocol-specific
+format with all scalar multibyte datatypes being big endian.
+Translation to this representation needs to be done both by the target
+before the `F' packet is sent, and by GDB before it transfers memory to
+the target. Transferred pointers to structured data should point to
+the already-coerced data at any time.
+
+
+File: gdb.info, Node: struct stat, Next: struct timeval, Prev: Memory Transfer, Up: Protocol-specific Representation of Datatypes
+
+struct stat
+...........
+
+The buffer of type `struct stat' used by the target and GDB is defined
+as follows:
+
+ struct stat {
+ unsigned int st_dev; /* device */
+ unsigned int st_ino; /* inode */
+ mode_t st_mode; /* protection */
+ unsigned int st_nlink; /* number of hard links */
+ unsigned int st_uid; /* user ID of owner */
+ unsigned int st_gid; /* group ID of owner */
+ unsigned int st_rdev; /* device type (if inode device) */
+ unsigned long st_size; /* total size, in bytes */
+ unsigned long st_blksize; /* blocksize for filesystem I/O */
+ unsigned long st_blocks; /* number of blocks allocated */
+ time_t st_atime; /* time of last access */
+ time_t st_mtime; /* time of last modification */
+ time_t st_ctime; /* time of last change */
+ };
+
+ The integral datatypes conform to the definitions given in the
+appropriate section (see *Note Integral Datatypes::, for details) so
+this structure is of size 64 bytes.
+
+ The values of several fields have a restricted meaning and/or range
+of values.
+
+`st_dev'
+ A value of 0 represents a file, 1 the console.
+
+`st_ino'
+ No valid meaning for the target. Transmitted unchanged.
+
+`st_mode'
+ Valid mode bits are described in *Note Constants::. Any other
+ bits have currently no meaning for the target.
+
+`st_uid'
+`st_gid'
+`st_rdev'
+ No valid meaning for the target. Transmitted unchanged.
+
+`st_atime'
+`st_mtime'
+`st_ctime'
+ These values have a host and file system dependent accuracy.
+ Especially on Windows hosts, the file system may not support exact
+ timing values.
+
+ The target gets a `struct stat' of the above representation and is
+responsible for coercing it to the target representation before
+continuing.
+
+ Note that due to size differences between the host, target, and
+protocol representations of `struct stat' members, these members could
+eventually get truncated on the target.
+
+
+File: gdb.info, Node: struct timeval, Prev: struct stat, Up: Protocol-specific Representation of Datatypes
+
+struct timeval
+..............
+
+The buffer of type `struct timeval' used by the File-I/O protocol is
+defined as follows:
+
+ struct timeval {
+ time_t tv_sec; /* second */
+ long tv_usec; /* microsecond */
+ };
+
+ The integral datatypes conform to the definitions given in the
+appropriate section (see *Note Integral Datatypes::, for details) so
+this structure is of size 8 bytes.
+
+
+File: gdb.info, Node: Constants, Next: File-I/O Examples, Prev: Protocol-specific Representation of Datatypes, Up: File-I/O Remote Protocol Extension
+
+E.13.9 Constants
+----------------
+
+The following values are used for the constants inside of the protocol.
+GDB and target are responsible for translating these values before and
+after the call as needed.
+
+* Menu:
+
+* Open Flags::
+* mode_t Values::
+* Errno Values::
+* Lseek Flags::
+* Limits::
+
+
+File: gdb.info, Node: Open Flags, Next: mode_t Values, Up: Constants
+
+Open Flags
+..........
+
+All values are given in hexadecimal representation.
+
+ O_RDONLY 0x0
+ O_WRONLY 0x1
+ O_RDWR 0x2
+ O_APPEND 0x8
+ O_CREAT 0x200
+ O_TRUNC 0x400
+ O_EXCL 0x800
+
+
+File: gdb.info, Node: mode_t Values, Next: Errno Values, Prev: Open Flags, Up: Constants
+
+mode_t Values
+.............
+
+All values are given in octal representation.
+
+ S_IFREG 0100000
+ S_IFDIR 040000
+ S_IRUSR 0400
+ S_IWUSR 0200
+ S_IXUSR 0100
+ S_IRGRP 040
+ S_IWGRP 020
+ S_IXGRP 010
+ S_IROTH 04
+ S_IWOTH 02
+ S_IXOTH 01
+
+
+File: gdb.info, Node: Errno Values, Next: Lseek Flags, Prev: mode_t Values, Up: Constants
+
+Errno Values
+............
+
+All values are given in decimal representation.
+
+ EPERM 1
+ ENOENT 2
+ EINTR 4
+ EBADF 9
+ EACCES 13
+ EFAULT 14
+ EBUSY 16
+ EEXIST 17
+ ENODEV 19
+ ENOTDIR 20
+ EISDIR 21
+ EINVAL 22
+ ENFILE 23
+ EMFILE 24
+ EFBIG 27
+ ENOSPC 28
+ ESPIPE 29
+ EROFS 30
+ ENAMETOOLONG 91
+ EUNKNOWN 9999
+
+ `EUNKNOWN' is used as a fallback error value if a host system returns
+ any error value not in the list of supported error numbers.
+
+
+File: gdb.info, Node: Lseek Flags, Next: Limits, Prev: Errno Values, Up: Constants
+
+Lseek Flags
+...........
+
+ SEEK_SET 0
+ SEEK_CUR 1
+ SEEK_END 2
+
+
+File: gdb.info, Node: Limits, Prev: Lseek Flags, Up: Constants
+
+Limits
+......
+
+All values are given in decimal representation.
+
+ INT_MIN -2147483648
+ INT_MAX 2147483647
+ UINT_MAX 4294967295
+ LONG_MIN -9223372036854775808
+ LONG_MAX 9223372036854775807
+ ULONG_MAX 18446744073709551615
+
+
+File: gdb.info, Node: File-I/O Examples, Prev: Constants, Up: File-I/O Remote Protocol Extension
+
+E.13.10 File-I/O Examples
+-------------------------
+
+Example sequence of a write call, file descriptor 3, buffer is at target
+address 0x1234, 6 bytes should be written:
+
+ <- `Fwrite,3,1234,6'
+ _request memory read from target_
+ -> `m1234,6'
+ <- XXXXXX
+ _return "6 bytes written"_
+ -> `F6'
+
+ Example sequence of a read call, file descriptor 3, buffer is at
+target address 0x1234, 6 bytes should be read:
+
+ <- `Fread,3,1234,6'
+ _request memory write to target_
+ -> `X1234,6:XXXXXX'
+ _return "6 bytes read"_
+ -> `F6'
+
+ Example sequence of a read call, call fails on the host due to
+invalid file descriptor (`EBADF'):
+
+ <- `Fread,3,1234,6'
+ -> `F-1,9'
+
+ Example sequence of a read call, user presses `Ctrl-c' before
+syscall on host is called:
+
+ <- `Fread,3,1234,6'
+ -> `F-1,4,C'
+ <- `T02'
+
+ Example sequence of a read call, user presses `Ctrl-c' after syscall
+on host is called:
+
+ <- `Fread,3,1234,6'
+ -> `X1234,6:XXXXXX'
+ <- `T02'
+
+
+File: gdb.info, Node: Library List Format, Next: Library List Format for SVR4 Targets, Prev: File-I/O Remote Protocol Extension, Up: Remote Protocol
+
+E.14 Library List Format
+========================
+
+On some platforms, a dynamic loader (e.g. `ld.so') runs in the same
+process as your application to manage libraries. In this case, GDB can
+use the loader's symbol table and normal memory operations to maintain
+a list of shared libraries. On other platforms, the operating system
+manages loaded libraries. GDB can not retrieve the list of currently
+loaded libraries through memory operations, so it uses the
+`qXfer:libraries:read' packet (*note qXfer library list read::)
+instead. The remote stub queries the target's operating system and
+reports which libraries are loaded.
+
+ The `qXfer:libraries:read' packet returns an XML document which
+lists loaded libraries and their offsets. Each library has an
+associated name and one or more segment or section base addresses,
+which report where the library was loaded in memory.
+
+ For the common case of libraries that are fully linked binaries, the
+library should have a list of segments. If the target supports dynamic
+linking of a relocatable object file, its library XML element should
+instead include a list of allocated sections. The segment or section
+bases are start addresses, not relocation offsets; they do not depend
+on the library's link-time base addresses.
+
+ GDB must be linked with the Expat library to support XML library
+lists. *Note Expat::.
+
+ A simple memory map, with one loaded library relocated by a single
+offset, looks like this:
+
+ <library-list>
+ <library name="/lib/libc.so.6">
+ <segment address="0x10000000"/>
+ </library>
+ </library-list>
+
+ Another simple memory map, with one loaded library with three
+allocated sections (.text, .data, .bss), looks like this:
+
+ <library-list>
+ <library name="sharedlib.o">
+ <section address="0x10000000"/>
+ <section address="0x20000000"/>
+ <section address="0x30000000"/>
+ </library>
+ </library-list>
+
+ The format of a library list is described by this DTD:
+
+ <!-- library-list: Root element with versioning -->
+ <!ELEMENT library-list (library)*>
+ <!ATTLIST library-list version CDATA #FIXED "1.0">
+ <!ELEMENT library (segment*, section*)>
+ <!ATTLIST library name CDATA #REQUIRED>
+ <!ELEMENT segment EMPTY>
+ <!ATTLIST segment address CDATA #REQUIRED>
+ <!ELEMENT section EMPTY>
+ <!ATTLIST section address CDATA #REQUIRED>
+
+ In addition, segments and section descriptors cannot be mixed within
+a single library element, and you must supply at least one segment or
+section for each library.
+
+
+File: gdb.info, Node: Library List Format for SVR4 Targets, Next: Memory Map Format, Prev: Library List Format, Up: Remote Protocol
+
+E.15 Library List Format for SVR4 Targets
+=========================================
+
+On SVR4 platforms GDB can use the symbol table of a dynamic loader
+(e.g. `ld.so') and normal memory operations to maintain a list of
+shared libraries. Still a special library list provided by this packet
+is more efficient for the GDB remote protocol.
+
+ The `qXfer:libraries-svr4:read' packet returns an XML document which
+lists loaded libraries and their SVR4 linker parameters. For each
+library on SVR4 target, the following parameters are reported:
+
+ - `name', the absolute file name from the `l_name' field of `struct
+ link_map'.
+
+ - `lm' with address of `struct link_map' used for TLS (Thread Local
+ Storage) access.
+
+ - `l_addr', the displacement as read from the field `l_addr' of
+ `struct link_map'. For prelinked libraries this is not an absolute
+ memory address. It is a displacement of absolute memory address
+ against address the file was prelinked to during the library load.
+
+ - `l_ld', which is memory address of the `PT_DYNAMIC' segment
+
+ Additionally the single `main-lm' attribute specifies address of
+`struct link_map' used for the main executable. This parameter is used
+for TLS access and its presence is optional.
+
+ GDB must be linked with the Expat library to support XML SVR4
+library lists. *Note Expat::.
+
+ A simple memory map, with two loaded libraries (which do not use
+prelink), looks like this:
+
+ <library-list-svr4 version="1.0" main-lm="0xe4f8f8">
+ <library name="/lib/ld-linux.so.2" lm="0xe4f51c" l_addr="0xe2d000"
+ l_ld="0xe4eefc"/>
+ <library name="/lib/libc.so.6" lm="0xe4fbe8" l_addr="0x154000"
+ l_ld="0x152350"/>
+ </library-list-svr>
+
+ The format of an SVR4 library list is described by this DTD:
+
+ <!-- library-list-svr4: Root element with versioning -->
+ <!ELEMENT library-list-svr4 (library)*>
+ <!ATTLIST library-list-svr4 version CDATA #FIXED "1.0">
+ <!ATTLIST library-list-svr4 main-lm CDATA #IMPLIED>
+ <!ELEMENT library EMPTY>
+ <!ATTLIST library name CDATA #REQUIRED>
+ <!ATTLIST library lm CDATA #REQUIRED>
+ <!ATTLIST library l_addr CDATA #REQUIRED>
+ <!ATTLIST library l_ld CDATA #REQUIRED>
+
+
+File: gdb.info, Node: Memory Map Format, Next: Thread List Format, Prev: Library List Format for SVR4 Targets, Up: Remote Protocol
+
+E.16 Memory Map Format
+======================
+
+To be able to write into flash memory, GDB needs to obtain a memory map
+from the target. This section describes the format of the memory map.
+
+ The memory map is obtained using the `qXfer:memory-map:read' (*note
+qXfer memory map read::) packet and is an XML document that lists
+memory regions.
+
+ GDB must be linked with the Expat library to support XML memory
+maps. *Note Expat::.
+
+ The top-level structure of the document is shown below:
+
+ <?xml version="1.0"?>
+ <!DOCTYPE memory-map
+ PUBLIC "+//IDN gnu.org//DTD GDB Memory Map V1.0//EN"
+ "http://sourceware.org/gdb/gdb-memory-map.dtd">
+ <memory-map>
+ region...
+ </memory-map>
+
+ Each region can be either:
+
+ * A region of RAM starting at ADDR and extending for LENGTH bytes
+ from there:
+
+ <memory type="ram" start="ADDR" length="LENGTH"/>
+
+ * A region of read-only memory:
+
+ <memory type="rom" start="ADDR" length="LENGTH"/>
+
+ * A region of flash memory, with erasure blocks BLOCKSIZE bytes in
+ length:
+
+ <memory type="flash" start="ADDR" length="LENGTH">
+ <property name="blocksize">BLOCKSIZE</property>
+ </memory>
+
+
+ Regions must not overlap. GDB assumes that areas of memory not
+covered by the memory map are RAM, and uses the ordinary `M' and `X'
+packets to write to addresses in such ranges.
+
+ The formal DTD for memory map format is given below:
+
+ <!-- ................................................... -->
+ <!-- Memory Map XML DTD ................................ -->
+ <!-- File: memory-map.dtd .............................. -->
+ <!-- .................................... .............. -->
+ <!-- memory-map.dtd -->
+ <!-- memory-map: Root element with versioning -->
+ <!ELEMENT memory-map (memory | property)>
+ <!ATTLIST memory-map version CDATA #FIXED "1.0.0">
+ <!ELEMENT memory (property)>
+ <!-- memory: Specifies a memory region,
+ and its type, or device. -->
+ <!ATTLIST memory type CDATA #REQUIRED
+ start CDATA #REQUIRED
+ length CDATA #REQUIRED
+ device CDATA #IMPLIED>
+ <!-- property: Generic attribute tag -->
+ <!ELEMENT property (#PCDATA | property)*>
+ <!ATTLIST property name CDATA #REQUIRED>
+
+
+File: gdb.info, Node: Thread List Format, Next: Traceframe Info Format, Prev: Memory Map Format, Up: Remote Protocol
+
+E.17 Thread List Format
+=======================
+
+To efficiently update the list of threads and their attributes, GDB
+issues the `qXfer:threads:read' packet (*note qXfer threads read::) and
+obtains the XML document with the following structure:
+
+ <?xml version="1.0"?>
+ <threads>
+ <thread id="id" core="0">
+ ... description ...
+ </thread>
+ </threads>
+
+ Each `thread' element must have the `id' attribute that identifies
+the thread (*note thread-id syntax::). The `core' attribute, if
+present, specifies which processor core the thread was last executing
+on. The content of the of `thread' element is interpreted as
+human-readable auxilliary information.
+
+
+File: gdb.info, Node: Traceframe Info Format, Prev: Thread List Format, Up: Remote Protocol
+
+E.18 Traceframe Info Format
+===========================
+
+To be able to know which objects in the inferior can be examined when
+inspecting a tracepoint hit, GDB needs to obtain the list of memory
+ranges, registers and trace state variables that have been collected in
+a traceframe.
+
+ This list is obtained using the `qXfer:traceframe-info:read' (*note
+qXfer traceframe info read::) packet and is an XML document.
+
+ GDB must be linked with the Expat library to support XML traceframe
+info discovery. *Note Expat::.
+
+ The top-level structure of the document is shown below:
+
+ <?xml version="1.0"?>
+ <!DOCTYPE traceframe-info
+ PUBLIC "+//IDN gnu.org//DTD GDB Memory Map V1.0//EN"
+ "http://sourceware.org/gdb/gdb-traceframe-info.dtd">
+ <traceframe-info>
+ block...
+ </traceframe-info>
+
+ Each traceframe block can be either:
+
+ * A region of collected memory starting at ADDR and extending for
+ LENGTH bytes from there:
+
+ <memory start="ADDR" length="LENGTH"/>
+
+
+ The formal DTD for the traceframe info format is given below:
+
+ <!ELEMENT traceframe-info (memory)* >
+ <!ATTLIST traceframe-info version CDATA #FIXED "1.0">
+
+ <!ELEMENT memory EMPTY>
+ <!ATTLIST memory start CDATA #REQUIRED
+ length CDATA #REQUIRED>
+
+
+File: gdb.info, Node: Agent Expressions, Next: Target Descriptions, Prev: Remote Protocol, Up: Top
+
+Appendix F The GDB Agent Expression Mechanism
+*********************************************
+
+In some applications, it is not feasible for the debugger to interrupt
+the program's execution long enough for the developer to learn anything
+helpful about its behavior. If the program's correctness depends on its
+real-time behavior, delays introduced by a debugger might cause the
+program to fail, even when the code itself is correct. It is useful to
+be able to observe the program's behavior without interrupting it.
+
+ Using GDB's `trace' and `collect' commands, the user can specify
+locations in the program, and arbitrary expressions to evaluate when
+those locations are reached. Later, using the `tfind' command, she can
+examine the values those expressions had when the program hit the trace
+points. The expressions may also denote objects in memory --
+structures or arrays, for example -- whose values GDB should record;
+while visiting a particular tracepoint, the user may inspect those
+objects as if they were in memory at that moment. However, because GDB
+records these values without interacting with the user, it can do so
+quickly and unobtrusively, hopefully not disturbing the program's
+behavior.
+
+ When GDB is debugging a remote target, the GDB "agent" code running
+on the target computes the values of the expressions itself. To avoid
+having a full symbolic expression evaluator on the agent, GDB translates
+expressions in the source language into a simpler bytecode language, and
+then sends the bytecode to the agent; the agent then executes the
+bytecode, and records the values for GDB to retrieve later.
+
+ The bytecode language is simple; there are forty-odd opcodes, the
+bulk of which are the usual vocabulary of C operands (addition,
+subtraction, shifts, and so on) and various sizes of literals and
+memory reference operations. The bytecode interpreter operates
+strictly on machine-level values -- various sizes of integers and
+floating point numbers -- and requires no information about types or
+symbols; thus, the interpreter's internal data structures are simple,
+and each bytecode requires only a few native machine instructions to
+implement it. The interpreter is small, and strict limits on the
+memory and time required to evaluate an expression are easy to
+determine, making it suitable for use by the debugging agent in
+real-time applications.
+
+* Menu:
+
+* General Bytecode Design:: Overview of the interpreter.
+* Bytecode Descriptions:: What each one does.
+* Using Agent Expressions:: How agent expressions fit into the big picture.
+* Varying Target Capabilities:: How to discover what the target can do.
+* Rationale:: Why we did it this way.
+
+
+File: gdb.info, Node: General Bytecode Design, Next: Bytecode Descriptions, Up: Agent Expressions
+
+F.1 General Bytecode Design
+===========================
+
+The agent represents bytecode expressions as an array of bytes. Each
+instruction is one byte long (thus the term "bytecode"). Some
+instructions are followed by operand bytes; for example, the `goto'
+instruction is followed by a destination for the jump.
+
+ The bytecode interpreter is a stack-based machine; most instructions
+pop their operands off the stack, perform some operation, and push the
+result back on the stack for the next instruction to consume. Each
+element of the stack may contain either a integer or a floating point
+value; these values are as many bits wide as the largest integer that
+can be directly manipulated in the source language. Stack elements
+carry no record of their type; bytecode could push a value as an
+integer, then pop it as a floating point value. However, GDB will not
+generate code which does this. In C, one might define the type of a
+stack element as follows:
+ union agent_val {
+ LONGEST l;
+ DOUBLEST d;
+ };
+ where `LONGEST' and `DOUBLEST' are `typedef' names for the largest
+integer and floating point types on the machine.
+
+ By the time the bytecode interpreter reaches the end of the
+expression, the value of the expression should be the only value left
+on the stack. For tracing applications, `trace' bytecodes in the
+expression will have recorded the necessary data, and the value on the
+stack may be discarded. For other applications, like conditional
+breakpoints, the value may be useful.
+
+ Separate from the stack, the interpreter has two registers:
+`pc'
+ The address of the next bytecode to execute.
+
+`start'
+ The address of the start of the bytecode expression, necessary for
+ interpreting the `goto' and `if_goto' instructions.
+
+ Neither of these registers is directly visible to the bytecode
+language itself, but they are useful for defining the meanings of the
+bytecode operations.
+
+ There are no instructions to perform side effects on the running
+program, or call the program's functions; we assume that these
+expressions are only used for unobtrusive debugging, not for patching
+the running code.
+
+ Most bytecode instructions do not distinguish between the various
+sizes of values, and operate on full-width values; the upper bits of the
+values are simply ignored, since they do not usually make a difference
+to the value computed. The exceptions to this rule are:
+memory reference instructions (`ref'N)
+ There are distinct instructions to fetch different word sizes from
+ memory. Once on the stack, however, the values are treated as
+ full-size integers. They may need to be sign-extended; the `ext'
+ instruction exists for this purpose.
+
+the sign-extension instruction (`ext' N)
+ These clearly need to know which portion of their operand is to be
+ extended to occupy the full length of the word.
+
+
+ If the interpreter is unable to evaluate an expression completely for
+some reason (a memory location is inaccessible, or a divisor is zero,
+for example), we say that interpretation "terminates with an error".
+This means that the problem is reported back to the interpreter's caller
+in some helpful way. In general, code using agent expressions should
+assume that they may attempt to divide by zero, fetch arbitrary memory
+locations, and misbehave in other ways.
+
+ Even complicated C expressions compile to a few bytecode
+instructions; for example, the expression `x + y * z' would typically
+produce code like the following, assuming that `x' and `y' live in
+registers, and `z' is a global variable holding a 32-bit `int':
+ reg 1
+ reg 2
+ const32 address of z
+ ref32
+ ext 32
+ mul
+ add
+ end
+
+ In detail, these mean:
+`reg 1'
+ Push the value of register 1 (presumably holding `x') onto the
+ stack.
+
+`reg 2'
+ Push the value of register 2 (holding `y').
+
+`const32 address of z'
+ Push the address of `z' onto the stack.
+
+`ref32'
+ Fetch a 32-bit word from the address at the top of the stack;
+ replace the address on the stack with the value. Thus, we replace
+ the address of `z' with `z''s value.
+
+`ext 32'
+ Sign-extend the value on the top of the stack from 32 bits to full
+ length. This is necessary because `z' is a signed integer.
+
+`mul'
+ Pop the top two numbers on the stack, multiply them, and push their
+ product. Now the top of the stack contains the value of the
+ expression `y * z'.
+
+`add'
+ Pop the top two numbers, add them, and push the sum. Now the top
+ of the stack contains the value of `x + y * z'.
+
+`end'
+ Stop executing; the value left on the stack top is the value to be
+ recorded.
+
+
+
+File: gdb.info, Node: Bytecode Descriptions, Next: Using Agent Expressions, Prev: General Bytecode Design, Up: Agent Expressions
+
+F.2 Bytecode Descriptions
+=========================
+
+Each bytecode description has the following form:
+
+`add' (0x02): A B => A+B
+ Pop the top two stack items, A and B, as integers; push their sum,
+ as an integer.
+
+
+ In this example, `add' is the name of the bytecode, and `(0x02)' is
+the one-byte value used to encode the bytecode, in hexadecimal. The
+phrase "A B => A+B" shows the stack before and after the bytecode
+executes. Beforehand, the stack must contain at least two values, A
+and B; since the top of the stack is to the right, B is on the top of
+the stack, and A is underneath it. After execution, the bytecode will
+have popped A and B from the stack, and replaced them with a single
+value, A+B. There may be other values on the stack below those shown,
+but the bytecode affects only those shown.
+
+ Here is another example:
+
+`const8' (0x22) N: => N
+ Push the 8-bit integer constant N on the stack, without sign
+ extension.
+
+
+ In this example, the bytecode `const8' takes an operand N directly
+from the bytecode stream; the operand follows the `const8' bytecode
+itself. We write any such operands immediately after the name of the
+bytecode, before the colon, and describe the exact encoding of the
+operand in the bytecode stream in the body of the bytecode description.
+
+ For the `const8' bytecode, there are no stack items given before the
+=>; this simply means that the bytecode consumes no values from the
+stack. If a bytecode consumes no values, or produces no values, the
+list on either side of the => may be empty.
+
+ If a value is written as A, B, or N, then the bytecode treats it as
+an integer. If a value is written is ADDR, then the bytecode treats it
+as an address.
+
+ We do not fully describe the floating point operations here; although
+this design can be extended in a clean way to handle floating point
+values, they are not of immediate interest to the customer, so we avoid
+describing them, to save time.
+
+`float' (0x01): =>
+ Prefix for floating-point bytecodes. Not implemented yet.
+
+`add' (0x02): A B => A+B
+ Pop two integers from the stack, and push their sum, as an integer.
+
+`sub' (0x03): A B => A-B
+ Pop two integers from the stack, subtract the top value from the
+ next-to-top value, and push the difference.
+
+`mul' (0x04): A B => A*B
+ Pop two integers from the stack, multiply them, and push the
+ product on the stack. Note that, when one multiplies two N-bit
+ numbers yielding another N-bit number, it is irrelevant whether the
+ numbers are signed or not; the results are the same.
+
+`div_signed' (0x05): A B => A/B
+ Pop two signed integers from the stack; divide the next-to-top
+ value by the top value, and push the quotient. If the divisor is
+ zero, terminate with an error.
+
+`div_unsigned' (0x06): A B => A/B
+ Pop two unsigned integers from the stack; divide the next-to-top
+ value by the top value, and push the quotient. If the divisor is
+ zero, terminate with an error.
+
+`rem_signed' (0x07): A B => A MODULO B
+ Pop two signed integers from the stack; divide the next-to-top
+ value by the top value, and push the remainder. If the divisor is
+ zero, terminate with an error.
+
+`rem_unsigned' (0x08): A B => A MODULO B
+ Pop two unsigned integers from the stack; divide the next-to-top
+ value by the top value, and push the remainder. If the divisor is
+ zero, terminate with an error.
+
+`lsh' (0x09): A B => A<<B
+ Pop two integers from the stack; let A be the next-to-top value,
+ and B be the top value. Shift A left by B bits, and push the
+ result.
+
+`rsh_signed' (0x0a): A B => `(signed)'A>>B
+ Pop two integers from the stack; let A be the next-to-top value,
+ and B be the top value. Shift A right by B bits, inserting copies
+ of the top bit at the high end, and push the result.
+
+`rsh_unsigned' (0x0b): A B => A>>B
+ Pop two integers from the stack; let A be the next-to-top value,
+ and B be the top value. Shift A right by B bits, inserting zero
+ bits at the high end, and push the result.
+
+`log_not' (0x0e): A => !A
+ Pop an integer from the stack; if it is zero, push the value one;
+ otherwise, push the value zero.
+
+`bit_and' (0x0f): A B => A&B
+ Pop two integers from the stack, and push their bitwise `and'.
+
+`bit_or' (0x10): A B => A|B
+ Pop two integers from the stack, and push their bitwise `or'.
+
+`bit_xor' (0x11): A B => A^B
+ Pop two integers from the stack, and push their bitwise
+ exclusive-`or'.
+
+`bit_not' (0x12): A => ~A
+ Pop an integer from the stack, and push its bitwise complement.
+
+`equal' (0x13): A B => A=B
+ Pop two integers from the stack; if they are equal, push the value
+ one; otherwise, push the value zero.
+
+`less_signed' (0x14): A B => A<B
+ Pop two signed integers from the stack; if the next-to-top value
+ is less than the top value, push the value one; otherwise, push
+ the value zero.
+
+`less_unsigned' (0x15): A B => A<B
+ Pop two unsigned integers from the stack; if the next-to-top value
+ is less than the top value, push the value one; otherwise, push
+ the value zero.
+
+`ext' (0x16) N: A => A, sign-extended from N bits
+ Pop an unsigned value from the stack; treating it as an N-bit
+ twos-complement value, extend it to full length. This means that
+ all bits to the left of bit N-1 (where the least significant bit
+ is bit 0) are set to the value of bit N-1. Note that N may be
+ larger than or equal to the width of the stack elements of the
+ bytecode engine; in this case, the bytecode should have no effect.
+
+ The number of source bits to preserve, N, is encoded as a single
+ byte unsigned integer following the `ext' bytecode.
+
+`zero_ext' (0x2a) N: A => A, zero-extended from N bits
+ Pop an unsigned value from the stack; zero all but the bottom N
+ bits. This means that all bits to the left of bit N-1 (where the
+ least significant bit is bit 0) are set to the value of bit N-1.
+
+ The number of source bits to preserve, N, is encoded as a single
+ byte unsigned integer following the `zero_ext' bytecode.
+
+`ref8' (0x17): ADDR => A
+`ref16' (0x18): ADDR => A
+`ref32' (0x19): ADDR => A
+`ref64' (0x1a): ADDR => A
+ Pop an address ADDR from the stack. For bytecode `ref'N, fetch an
+ N-bit value from ADDR, using the natural target endianness. Push
+ the fetched value as an unsigned integer.
+
+ Note that ADDR may not be aligned in any particular way; the
+ `refN' bytecodes should operate correctly for any address.
+
+ If attempting to access memory at ADDR would cause a processor
+ exception of some sort, terminate with an error.
+
+`ref_float' (0x1b): ADDR => D
+`ref_double' (0x1c): ADDR => D
+`ref_long_double' (0x1d): ADDR => D
+`l_to_d' (0x1e): A => D
+`d_to_l' (0x1f): D => A
+ Not implemented yet.
+
+`dup' (0x28): A => A A
+ Push another copy of the stack's top element.
+
+`swap' (0x2b): A B => B A
+ Exchange the top two items on the stack.
+
+`pop' (0x29): A =>
+ Discard the top value on the stack.
+
+`pick' (0x32) N: A ... B => A ... B A
+ Duplicate an item from the stack and push it on the top of the
+ stack. N, a single byte, indicates the stack item to copy. If N
+ is zero, this is the same as `dup'; if N is one, it copies the
+ item under the top item, etc. If N exceeds the number of items on
+ the stack, terminate with an error.
+
+`rot' (0x33): A B C => C B A
+ Rotate the top three items on the stack.
+
+`if_goto' (0x20) OFFSET: A =>
+ Pop an integer off the stack; if it is non-zero, branch to the
+ given offset in the bytecode string. Otherwise, continue to the
+ next instruction in the bytecode stream. In other words, if A is
+ non-zero, set the `pc' register to `start' + OFFSET. Thus, an
+ offset of zero denotes the beginning of the expression.
+
+ The OFFSET is stored as a sixteen-bit unsigned value, stored
+ immediately following the `if_goto' bytecode. It is always stored
+ most significant byte first, regardless of the target's normal
+ endianness. The offset is not guaranteed to fall at any particular
+ alignment within the bytecode stream; thus, on machines where
+ fetching a 16-bit on an unaligned address raises an exception, you
+ should fetch the offset one byte at a time.
+
+`goto' (0x21) OFFSET: =>
+ Branch unconditionally to OFFSET; in other words, set the `pc'
+ register to `start' + OFFSET.
+
+ The offset is stored in the same way as for the `if_goto' bytecode.
+
+`const8' (0x22) N: => N
+`const16' (0x23) N: => N
+`const32' (0x24) N: => N
+`const64' (0x25) N: => N
+ Push the integer constant N on the stack, without sign extension.
+ To produce a small negative value, push a small twos-complement
+ value, and then sign-extend it using the `ext' bytecode.
+
+ The constant N is stored in the appropriate number of bytes
+ following the `const'B bytecode. The constant N is always stored
+ most significant byte first, regardless of the target's normal
+ endianness. The constant is not guaranteed to fall at any
+ particular alignment within the bytecode stream; thus, on machines
+ where fetching a 16-bit on an unaligned address raises an
+ exception, you should fetch N one byte at a time.
+
+`reg' (0x26) N: => A
+ Push the value of register number N, without sign extension. The
+ registers are numbered following GDB's conventions.
+
+ The register number N is encoded as a 16-bit unsigned integer
+ immediately following the `reg' bytecode. It is always stored most
+ significant byte first, regardless of the target's normal
+ endianness. The register number is not guaranteed to fall at any
+ particular alignment within the bytecode stream; thus, on machines
+ where fetching a 16-bit on an unaligned address raises an
+ exception, you should fetch the register number one byte at a time.
+
+`getv' (0x2c) N: => V
+ Push the value of trace state variable number N, without sign
+ extension.
+
+ The variable number N is encoded as a 16-bit unsigned integer
+ immediately following the `getv' bytecode. It is always stored
+ most significant byte first, regardless of the target's normal
+ endianness. The variable number is not guaranteed to fall at any
+ particular alignment within the bytecode stream; thus, on machines
+ where fetching a 16-bit on an unaligned address raises an
+ exception, you should fetch the register number one byte at a time.
+
+`setv' (0x2d) N: => V
+ Set trace state variable number N to the value found on the top of
+ the stack. The stack is unchanged, so that the value is readily
+ available if the assignment is part of a larger expression. The
+ handling of N is as described for `getv'.
+
+`trace' (0x0c): ADDR SIZE =>
+ Record the contents of the SIZE bytes at ADDR in a trace buffer,
+ for later retrieval by GDB.
+
+`trace_quick' (0x0d) SIZE: ADDR => ADDR
+ Record the contents of the SIZE bytes at ADDR in a trace buffer,
+ for later retrieval by GDB. SIZE is a single byte unsigned
+ integer following the `trace' opcode.
+
+ This bytecode is equivalent to the sequence `dup const8 SIZE
+ trace', but we provide it anyway to save space in bytecode strings.
+
+`trace16' (0x30) SIZE: ADDR => ADDR
+ Identical to trace_quick, except that SIZE is a 16-bit big-endian
+ unsigned integer, not a single byte. This should probably have
+ been named `trace_quick16', for consistency.
+
+`tracev' (0x2e) N: => A
+ Record the value of trace state variable number N in the trace
+ buffer. The handling of N is as described for `getv'.
+
+`tracenz' (0x2f) ADDR SIZE =>
+ Record the bytes at ADDR in a trace buffer, for later retrieval by
+ GDB. Stop at either the first zero byte, or when SIZE bytes have
+ been recorded, whichever occurs first.
+
+`end' (0x27): =>
+ Stop executing bytecode; the result should be the top element of
+ the stack. If the purpose of the expression was to compute an
+ lvalue or a range of memory, then the next-to-top of the stack is
+ the lvalue's address, and the top of the stack is the lvalue's
+ size, in bytes.
+
+
+
+File: gdb.info, Node: Using Agent Expressions, Next: Varying Target Capabilities, Prev: Bytecode Descriptions, Up: Agent Expressions
+
+F.3 Using Agent Expressions
+===========================
+
+Agent expressions can be used in several different ways by GDB, and the
+debugger can generate different bytecode sequences as appropriate.
+
+ One possibility is to do expression evaluation on the target rather
+than the host, such as for the conditional of a conditional tracepoint.
+In such a case, GDB compiles the source expression into a bytecode
+sequence that simply gets values from registers or memory, does
+arithmetic, and returns a result.
+
+ Another way to use agent expressions is for tracepoint data
+collection. GDB generates a different bytecode sequence for
+collection; in addition to bytecodes that do the calculation, GDB adds
+`trace' bytecodes to save the pieces of memory that were used.
+
+ * The user selects trace points in the program's code at which GDB
+ should collect data.
+
+ * The user specifies expressions to evaluate at each trace point.
+ These expressions may denote objects in memory, in which case
+ those objects' contents are recorded as the program runs, or
+ computed values, in which case the values themselves are recorded.
+
+ * GDB transmits the tracepoints and their associated expressions to
+ the GDB agent, running on the debugging target.
+
+ * The agent arranges to be notified when a trace point is hit.
+
+ * When execution on the target reaches a trace point, the agent
+ evaluates the expressions associated with that trace point, and
+ records the resulting values and memory ranges.
+
+ * Later, when the user selects a given trace event and inspects the
+ objects and expression values recorded, GDB talks to the agent to
+ retrieve recorded data as necessary to meet the user's requests.
+ If the user asks to see an object whose contents have not been
+ recorded, GDB reports an error.
+
+
+
+File: gdb.info, Node: Varying Target Capabilities, Next: Rationale, Prev: Using Agent Expressions, Up: Agent Expressions
+
+F.4 Varying Target Capabilities
+===============================
+
+Some targets don't support floating-point, and some would rather not
+have to deal with `long long' operations. Also, different targets will
+have different stack sizes, and different bytecode buffer lengths.
+
+ Thus, GDB needs a way to ask the target about itself. We haven't
+worked out the details yet, but in general, GDB should be able to send
+the target a packet asking it to describe itself. The reply should be a
+packet whose length is explicit, so we can add new information to the
+packet in future revisions of the agent, without confusing old versions
+of GDB, and it should contain a version number. It should contain at
+least the following information:
+
+ * whether floating point is supported
+
+ * whether `long long' is supported
+
+ * maximum acceptable size of bytecode stack
+
+ * maximum acceptable length of bytecode expressions
+
+ * which registers are actually available for collection
+
+ * whether the target supports disabled tracepoints
+
+
+
+File: gdb.info, Node: Rationale, Prev: Varying Target Capabilities, Up: Agent Expressions
+
+F.5 Rationale
+=============
+
+Some of the design decisions apparent above are arguable.
+
+What about stack overflow/underflow?
+ GDB should be able to query the target to discover its stack size.
+ Given that information, GDB can determine at translation time
+ whether a given expression will overflow the stack. But this spec
+ isn't about what kinds of error-checking GDB ought to do.
+
+Why are you doing everything in LONGEST?
+ Speed isn't important, but agent code size is; using LONGEST
+ brings in a bunch of support code to do things like division, etc.
+ So this is a serious concern.
+
+ First, note that you don't need different bytecodes for different
+ operand sizes. You can generate code without _knowing_ how big the
+ stack elements actually are on the target. If the target only
+ supports 32-bit ints, and you don't send any 64-bit bytecodes,
+ everything just works. The observation here is that the MIPS and
+ the Alpha have only fixed-size registers, and you can still get
+ C's semantics even though most instructions only operate on
+ full-sized words. You just need to make sure everything is
+ properly sign-extended at the right times. So there is no need
+ for 32- and 64-bit variants of the bytecodes. Just implement
+ everything using the largest size you support.
+
+ GDB should certainly check to see what sizes the target supports,
+ so the user can get an error earlier, rather than later. But this
+ information is not necessary for correctness.
+
+Why don't you have `>' or `<=' operators?
+ I want to keep the interpreter small, and we don't need them. We
+ can combine the `less_' opcodes with `log_not', and swap the order
+ of the operands, yielding all four asymmetrical comparison
+ operators. For example, `(x <= y)' is `! (x > y)', which is `! (y
+ < x)'.
+
+Why do you have `log_not'?
+Why do you have `ext'?
+Why do you have `zero_ext'?
+ These are all easily synthesized from other instructions, but I
+ expect them to be used frequently, and they're simple, so I
+ include them to keep bytecode strings short.
+
+ `log_not' is equivalent to `const8 0 equal'; it's used in half the
+ relational operators.
+
+ `ext N' is equivalent to `const8 S-N lsh const8 S-N rsh_signed',
+ where S is the size of the stack elements; it follows `refM' and
+ REG bytecodes when the value should be signed. See the next
+ bulleted item.
+
+ `zero_ext N' is equivalent to `constM MASK log_and'; it's used
+ whenever we push the value of a register, because we can't assume
+ the upper bits of the register aren't garbage.
+
+Why not have sign-extending variants of the `ref' operators?
+ Because that would double the number of `ref' operators, and we
+ need the `ext' bytecode anyway for accessing bitfields.
+
+Why not have constant-address variants of the `ref' operators?
+ Because that would double the number of `ref' operators again, and
+ `const32 ADDRESS ref32' is only one byte longer.
+
+Why do the `refN' operators have to support unaligned fetches?
+ GDB will generate bytecode that fetches multi-byte values at
+ unaligned addresses whenever the executable's debugging
+ information tells it to. Furthermore, GDB does not know the value
+ the pointer will have when GDB generates the bytecode, so it
+ cannot determine whether a particular fetch will be aligned or not.
+
+ In particular, structure bitfields may be several bytes long, but
+ follow no alignment rules; members of packed structures are not
+ necessarily aligned either.
+
+ In general, there are many cases where unaligned references occur
+ in correct C code, either at the programmer's explicit request, or
+ at the compiler's discretion. Thus, it is simpler to make the GDB
+ agent bytecodes work correctly in all circumstances than to make
+ GDB guess in each case whether the compiler did the usual thing.
+
+Why are there no side-effecting operators?
+ Because our current client doesn't want them? That's a cheap
+ answer. I think the real answer is that I'm afraid of
+ implementing function calls. We should re-visit this issue after
+ the present contract is delivered.
+
+Why aren't the `goto' ops PC-relative?
+ The interpreter has the base address around anyway for PC bounds
+ checking, and it seemed simpler.
+
+Why is there only one offset size for the `goto' ops?
+ Offsets are currently sixteen bits. I'm not happy with this
+ situation either:
+
+ Suppose we have multiple branch ops with different offset sizes.
+ As I generate code left-to-right, all my jumps are forward jumps
+ (there are no loops in expressions), so I never know the target
+ when I emit the jump opcode. Thus, I have to either always assume
+ the largest offset size, or do jump relaxation on the code after I
+ generate it, which seems like a big waste of time.
+
+ I can imagine a reasonable expression being longer than 256 bytes.
+ I can't imagine one being longer than 64k. Thus, we need 16-bit
+ offsets. This kind of reasoning is so bogus, but relaxation is
+ pathetic.
+
+ The other approach would be to generate code right-to-left. Then
+ I'd always know my offset size. That might be fun.
+
+Where is the function call bytecode?
+ When we add side-effects, we should add this.
+
+Why does the `reg' bytecode take a 16-bit register number?
+ Intel's IA-64 architecture has 128 general-purpose registers, and
+ 128 floating-point registers, and I'm sure it has some random
+ control registers.
+
+Why do we need `trace' and `trace_quick'?
+ Because GDB needs to record all the memory contents and registers
+ an expression touches. If the user wants to evaluate an expression
+ `x->y->z', the agent must record the values of `x' and `x->y' as
+ well as the value of `x->y->z'.
+
+Don't the `trace' bytecodes make the interpreter less general?
+ They do mean that the interpreter contains special-purpose code,
+ but that doesn't mean the interpreter can only be used for that
+ purpose. If an expression doesn't use the `trace' bytecodes, they
+ don't get in its way.
+
+Why doesn't `trace_quick' consume its arguments the way everything else does?
+ In general, you do want your operators to consume their arguments;
+ it's consistent, and generally reduces the amount of stack
+ rearrangement necessary. However, `trace_quick' is a kludge to
+ save space; it only exists so we needn't write `dup const8 SIZE
+ trace' before every memory reference. Therefore, it's okay for it
+ not to consume its arguments; it's meant for a specific context in
+ which we know exactly what it should do with the stack. If we're
+ going to have a kludge, it should be an effective kludge.
+
+Why does `trace16' exist?
+ That opcode was added by the customer that contracted Cygnus for
+ the data tracing work. I personally think it is unnecessary;
+ objects that large will be quite rare, so it is okay to use `dup
+ const16 SIZE trace' in those cases.
+
+ Whatever we decide to do with `trace16', we should at least leave
+ opcode 0x30 reserved, to remain compatible with the customer who
+ added it.
+
+
+
+File: gdb.info, Node: Target Descriptions, Next: Operating System Information, Prev: Agent Expressions, Up: Top
+
+Appendix G Target Descriptions
+******************************
+
+One of the challenges of using GDB to debug embedded systems is that
+there are so many minor variants of each processor architecture in use.
+It is common practice for vendors to start with a standard processor
+core -- ARM, PowerPC, or MIPS, for example -- and then make changes to
+adapt it to a particular market niche. Some architectures have
+hundreds of variants, available from dozens of vendors. This leads to
+a number of problems:
+
+ * With so many different customized processors, it is difficult for
+ the GDB maintainers to keep up with the changes.
+
+ * Since individual variants may have short lifetimes or limited
+ audiences, it may not be worthwhile to carry information about
+ every variant in the GDB source tree.
+
+ * When GDB does support the architecture of the embedded system at
+ hand, the task of finding the correct architecture name to give the
+ `set architecture' command can be error-prone.
+
+ To address these problems, the GDB remote protocol allows a target
+system to not only identify itself to GDB, but to actually describe its
+own features. This lets GDB support processor variants it has never
+seen before -- to the extent that the descriptions are accurate, and
+that GDB understands them.
+
+ GDB must be linked with the Expat library to support XML target
+descriptions. *Note Expat::.
+
+* Menu:
+
+* Retrieving Descriptions:: How descriptions are fetched from a target.
+* Target Description Format:: The contents of a target description.
+* Predefined Target Types:: Standard types available for target
+ descriptions.
+* Standard Target Features:: Features GDB knows about.
+
+
+File: gdb.info, Node: Retrieving Descriptions, Next: Target Description Format, Up: Target Descriptions
+
+G.1 Retrieving Descriptions
+===========================
+
+Target descriptions can be read from the target automatically, or
+specified by the user manually. The default behavior is to read the
+description from the target. GDB retrieves it via the remote protocol
+using `qXfer' requests (*note qXfer: General Query Packets.). The
+ANNEX in the `qXfer' packet will be `target.xml'. The contents of the
+`target.xml' annex are an XML document, of the form described in *Note
+Target Description Format::.
+
+ Alternatively, you can specify a file to read for the target
+description. If a file is set, the target will not be queried. The
+commands to specify a file are:
+
+`set tdesc filename PATH'
+ Read the target description from PATH.
+
+`unset tdesc filename'
+ Do not read the XML target description from a file. GDB will use
+ the description supplied by the current target.
+
+`show tdesc filename'
+ Show the filename to read for a target description, if any.
+
+
+File: gdb.info, Node: Target Description Format, Next: Predefined Target Types, Prev: Retrieving Descriptions, Up: Target Descriptions
+
+G.2 Target Description Format
+=============================
+
+A target description annex is an XML (http://www.w3.org/XML/) document
+which complies with the Document Type Definition provided in the GDB
+sources in `gdb/features/gdb-target.dtd'. This means you can use
+generally available tools like `xmllint' to check that your feature
+descriptions are well-formed and valid. However, to help people
+unfamiliar with XML write descriptions for their targets, we also
+describe the grammar here.
+
+ Target descriptions can identify the architecture of the remote
+target and (for some architectures) provide information about custom
+register sets. They can also identify the OS ABI of the remote target.
+GDB can use this information to autoconfigure for your target, or to
+warn you if you connect to an unsupported target.
+
+ Here is a simple target description:
+
+ <target version="1.0">
+ <architecture>i386:x86-64</architecture>
+ </target>
+
+This minimal description only says that the target uses the x86-64
+architecture.
+
+ A target description has the following overall form, with [ ] marking
+optional elements and ... marking repeatable elements. The elements
+are explained further below.
+
+ <?xml version="1.0"?>
+ <!DOCTYPE target SYSTEM "gdb-target.dtd">
+ <target version="1.0">
+ [ARCHITECTURE]
+ [OSABI]
+ [COMPATIBLE]
+ [FEATURE...]
+ </target>
+
+The description is generally insensitive to whitespace and line breaks,
+under the usual common-sense rules. The XML version declaration and
+document type declaration can generally be omitted (GDB does not
+require them), but specifying them may be useful for XML validation
+tools. The `version' attribute for `<target>' may also be omitted, but
+we recommend including it; if future versions of GDB use an incompatible
+revision of `gdb-target.dtd', they will detect and report the version
+mismatch.
+
+G.2.1 Inclusion
+---------------
+
+It can sometimes be valuable to split a target description up into
+several different annexes, either for organizational purposes, or to
+share files between different possible target descriptions. You can
+divide a description into multiple files by replacing any element of
+the target description with an inclusion directive of the form:
+
+ <xi:include href="DOCUMENT"/>
+
+When GDB encounters an element of this form, it will retrieve the named
+XML DOCUMENT, and replace the inclusion directive with the contents of
+that document. If the current description was read using `qXfer', then
+so will be the included document; DOCUMENT will be interpreted as the
+name of an annex. If the current description was read from a file, GDB
+will look for DOCUMENT as a file in the same directory where it found
+the original description.
+
+G.2.2 Architecture
+------------------
+
+An `<architecture>' element has this form:
+
+ <architecture>ARCH</architecture>
+
+ ARCH is one of the architectures from the set accepted by `set
+architecture' (*note Specifying a Debugging Target: Targets.).
+
+G.2.3 OS ABI
+------------
+
+This optional field was introduced in GDB version 7.0. Previous
+versions of GDB ignore it.
+
+ An `<osabi>' element has this form:
+
+ <osabi>ABI-NAME</osabi>
+
+ ABI-NAME is an OS ABI name from the same selection accepted by
+`set osabi' (*note Configuring the Current ABI: ABI.).
+
+G.2.4 Compatible Architecture
+-----------------------------
+
+This optional field was introduced in GDB version 7.0. Previous
+versions of GDB ignore it.
+
+ A `<compatible>' element has this form:
+
+ <compatible>ARCH</compatible>
+
+ ARCH is one of the architectures from the set accepted by `set
+architecture' (*note Specifying a Debugging Target: Targets.).
+
+ A `<compatible>' element is used to specify that the target is able
+to run binaries in some other than the main target architecture given
+by the `<architecture>' element. For example, on the Cell Broadband
+Engine, the main architecture is `powerpc:common' or
+`powerpc:common64', but the system is able to run binaries in the `spu'
+architecture as well. The way to describe this capability with
+`<compatible>' is as follows:
+
+ <architecture>powerpc:common</architecture>
+ <compatible>spu</compatible>
+
+G.2.5 Features
+--------------
+
+Each `<feature>' describes some logical portion of the target system.
+Features are currently used to describe available CPU registers and the
+types of their contents. A `<feature>' element has this form:
+
+ <feature name="NAME">
+ [TYPE...]
+ REG...
+ </feature>
+
+Each feature's name should be unique within the description. The name
+of a feature does not matter unless GDB has some special knowledge of
+the contents of that feature; if it does, the feature should have its
+standard name. *Note Standard Target Features::.
+
+G.2.6 Types
+-----------
+
+Any register's value is a collection of bits which GDB must interpret.
+The default interpretation is a two's complement integer, but other
+types can be requested by name in the register description. Some
+predefined types are provided by GDB (*note Predefined Target Types::),
+and the description can define additional composite types.
+
+ Each type element must have an `id' attribute, which gives a unique
+(within the containing `<feature>') name to the type. Types must be
+defined before they are used.
+
+ Some targets offer vector registers, which can be treated as arrays
+of scalar elements. These types are written as `<vector>' elements,
+specifying the array element type, TYPE, and the number of elements,
+COUNT:
+
+ <vector id="ID" type="TYPE" count="COUNT"/>
+
+ If a register's value is usefully viewed in multiple ways, define it
+with a union type containing the useful representations. The `<union>'
+element contains one or more `<field>' elements, each of which has a
+NAME and a TYPE:
+
+ <union id="ID">
+ <field name="NAME" type="TYPE"/>
+ ...
+ </union>
+
+ If a register's value is composed from several separate values,
+define it with a structure type. There are two forms of the `<struct>'
+element; a `<struct>' element must either contain only bitfields or
+contain no bitfields. If the structure contains only bitfields, its
+total size in bytes must be specified, each bitfield must have an
+explicit start and end, and bitfields are automatically assigned an
+integer type. The field's START should be less than or equal to its
+END, and zero represents the least significant bit.
+
+ <struct id="ID" size="SIZE">
+ <field name="NAME" start="START" end="END"/>
+ ...
+ </struct>
+
+ If the structure contains no bitfields, then each field has an
+explicit type, and no implicit padding is added.
+
+ <struct id="ID">
+ <field name="NAME" type="TYPE"/>
+ ...
+ </struct>
+
+ If a register's value is a series of single-bit flags, define it with
+a flags type. The `<flags>' element has an explicit SIZE and contains
+one or more `<field>' elements. Each field has a NAME, a START, and an
+END. Only single-bit flags are supported.
+
+ <flags id="ID" size="SIZE">
+ <field name="NAME" start="START" end="END"/>
+ ...
+ </flags>
+
+G.2.7 Registers
+---------------
+
+Each register is represented as an element with this form:
+
+ <reg name="NAME"
+ bitsize="SIZE"
+ [regnum="NUM"]
+ [save-restore="SAVE-RESTORE"]
+ [type="TYPE"]
+ [group="GROUP"]/>
+
+The components are as follows:
+
+NAME
+ The register's name; it must be unique within the target
+ description.
+
+BITSIZE
+ The register's size, in bits.
+
+REGNUM
+ The register's number. If omitted, a register's number is one
+ greater than that of the previous register (either in the current
+ feature or in a preceding feature); the first register in the
+ target description defaults to zero. This register number is used
+ to read or write the register; e.g. it is used in the remote `p'
+ and `P' packets, and registers appear in the `g' and `G' packets
+ in order of increasing register number.
+
+SAVE-RESTORE
+ Whether the register should be preserved across inferior function
+ calls; this must be either `yes' or `no'. The default is `yes',
+ which is appropriate for most registers except for some system
+ control registers; this is not related to the target's ABI.
+
+TYPE
+ The type of the register. TYPE may be a predefined type, a type
+ defined in the current feature, or one of the special types `int'
+ and `float'. `int' is an integer type of the correct size for
+ BITSIZE, and `float' is a floating point type (in the
+ architecture's normal floating point format) of the correct size
+ for BITSIZE. The default is `int'.
+
+GROUP
+ The register group to which this register belongs. GROUP must be
+ either `general', `float', or `vector'. If no GROUP is specified,
+ GDB will not display the register in `info registers'.
+
+
+
+File: gdb.info, Node: Predefined Target Types, Next: Standard Target Features, Prev: Target Description Format, Up: Target Descriptions
+
+G.3 Predefined Target Types
+===========================
+
+Type definitions in the self-description can build up composite types
+from basic building blocks, but can not define fundamental types.
+Instead, standard identifiers are provided by GDB for the fundamental
+types. The currently supported types are:
+
+`int8'
+`int16'
+`int32'
+`int64'
+`int128'
+ Signed integer types holding the specified number of bits.
+
+`uint8'
+`uint16'
+`uint32'
+`uint64'
+`uint128'
+ Unsigned integer types holding the specified number of bits.
+
+`code_ptr'
+`data_ptr'
+ Pointers to unspecified code and data. The program counter and
+ any dedicated return address register may be marked as code
+ pointers; printing a code pointer converts it into a symbolic
+ address. The stack pointer and any dedicated address registers
+ may be marked as data pointers.
+
+`ieee_single'
+ Single precision IEEE floating point.
+
+`ieee_double'
+ Double precision IEEE floating point.
+
+`arm_fpa_ext'
+ The 12-byte extended precision format used by ARM FPA registers.
+
+`i387_ext'
+ The 10-byte extended precision format used by x87 registers.
+
+`i386_eflags'
+ 32bit EFLAGS register used by x86.
+
+`i386_mxcsr'
+ 32bit MXCSR register used by x86.
+
+
+
+File: gdb.info, Node: Standard Target Features, Prev: Predefined Target Types, Up: Target Descriptions
+
+G.4 Standard Target Features
+============================
+
+A target description must contain either no registers or all the
+target's registers. If the description contains no registers, then GDB
+will assume a default register layout, selected based on the
+architecture. If the description contains any registers, the default
+layout will not be used; the standard registers must be described in
+the target description, in such a way that GDB can recognize them.
+
+ This is accomplished by giving specific names to feature elements
+which contain standard registers. GDB will look for features with
+those names and verify that they contain the expected registers; if any
+known feature is missing required registers, or if any required feature
+is missing, GDB will reject the target description. You can add
+additional registers to any of the standard features -- GDB will
+display them just as if they were added to an unrecognized feature.
+
+ This section lists the known features and their expected contents.
+Sample XML documents for these features are included in the GDB source
+tree, in the directory `gdb/features'.
+
+ Names recognized by GDB should include the name of the company or
+organization which selected the name, and the overall architecture to
+which the feature applies; so e.g. the feature containing ARM core
+registers is named `org.gnu.gdb.arm.core'.
+
+ The names of registers are not case sensitive for the purpose of
+recognizing standard features, but GDB will only display registers
+using the capitalization used in the description.
+
+* Menu:
+
+* ARM Features::
+* i386 Features::
+* MIPS Features::
+* M68K Features::
+* PowerPC Features::
+* TIC6x Features::
+
+
+File: gdb.info, Node: ARM Features, Next: i386 Features, Up: Standard Target Features
+
+G.4.1 ARM Features
+------------------
+
+The `org.gnu.gdb.arm.core' feature is required for non-M-profile ARM
+targets. It should contain registers `r0' through `r13', `sp', `lr',
+`pc', and `cpsr'.
+
+ For M-profile targets (e.g. Cortex-M3), the `org.gnu.gdb.arm.core'
+feature is replaced by `org.gnu.gdb.arm.m-profile'. It should contain
+registers `r0' through `r13', `sp', `lr', `pc', and `xpsr'.
+
+ The `org.gnu.gdb.arm.fpa' feature is optional. If present, it
+should contain registers `f0' through `f7' and `fps'.
+
+ The `org.gnu.gdb.xscale.iwmmxt' feature is optional. If present, it
+should contain at least registers `wR0' through `wR15' and `wCGR0'
+through `wCGR3'. The `wCID', `wCon', `wCSSF', and `wCASF' registers
+are optional.
+
+ The `org.gnu.gdb.arm.vfp' feature is optional. If present, it
+should contain at least registers `d0' through `d15'. If they are
+present, `d16' through `d31' should also be included. GDB will
+synthesize the single-precision registers from halves of the
+double-precision registers.
+
+ The `org.gnu.gdb.arm.neon' feature is optional. It does not need to
+contain registers; it instructs GDB to display the VFP double-precision
+registers as vectors and to synthesize the quad-precision registers
+from pairs of double-precision registers. If this feature is present,
+`org.gnu.gdb.arm.vfp' must also be present and include 32
+double-precision registers.
+
+
+File: gdb.info, Node: i386 Features, Next: MIPS Features, Prev: ARM Features, Up: Standard Target Features
+
+G.4.2 i386 Features
+-------------------
+
+The `org.gnu.gdb.i386.core' feature is required for i386/amd64 targets.
+It should describe the following registers:
+
+ - `eax' through `edi' plus `eip' for i386
+
+ - `rax' through `r15' plus `rip' for amd64
+
+ - `eflags', `cs', `ss', `ds', `es', `fs', `gs'
+
+ - `st0' through `st7'
+
+ - `fctrl', `fstat', `ftag', `fiseg', `fioff', `foseg', `fooff' and
+ `fop'
+
+ The register sets may be different, depending on the target.
+
+ The `org.gnu.gdb.i386.sse' feature is optional. It should describe
+registers:
+
+ - `xmm0' through `xmm7' for i386
+
+ - `xmm0' through `xmm15' for amd64
+
+ - `mxcsr'
+
+ The `org.gnu.gdb.i386.avx' feature is optional and requires the
+`org.gnu.gdb.i386.sse' feature. It should describe the upper 128 bits
+of YMM registers:
+
+ - `ymm0h' through `ymm7h' for i386
+
+ - `ymm0h' through `ymm15h' for amd64
+
+ The `org.gnu.gdb.i386.linux' feature is optional. It should
+describe a single register, `orig_eax'.
+
+
+File: gdb.info, Node: MIPS Features, Next: M68K Features, Prev: i386 Features, Up: Standard Target Features
+
+G.4.3 MIPS Features
+-------------------
+
+The `org.gnu.gdb.mips.cpu' feature is required for MIPS targets. It
+should contain registers `r0' through `r31', `lo', `hi', and `pc'.
+They may be 32-bit or 64-bit depending on the target.
+
+ The `org.gnu.gdb.mips.cp0' feature is also required. It should
+contain at least the `status', `badvaddr', and `cause' registers. They
+may be 32-bit or 64-bit depending on the target.
+
+ The `org.gnu.gdb.mips.fpu' feature is currently required, though it
+may be optional in a future version of GDB. It should contain
+registers `f0' through `f31', `fcsr', and `fir'. They may be 32-bit or
+64-bit depending on the target.
+
+ The `org.gnu.gdb.mips.linux' feature is optional. It should contain
+a single register, `restart', which is used by the Linux kernel to
+control restartable syscalls.
+
+
+File: gdb.info, Node: M68K Features, Next: PowerPC Features, Prev: MIPS Features, Up: Standard Target Features
+
+G.4.4 M68K Features
+-------------------
+
+``org.gnu.gdb.m68k.core''
+``org.gnu.gdb.coldfire.core''
+``org.gnu.gdb.fido.core''
+ One of those features must be always present. The feature that is
+ present determines which flavor of m68k is used. The feature that
+ is present should contain registers `d0' through `d7', `a0'
+ through `a5', `fp', `sp', `ps' and `pc'.
+
+``org.gnu.gdb.coldfire.fp''
+ This feature is optional. If present, it should contain registers
+ `fp0' through `fp7', `fpcontrol', `fpstatus' and `fpiaddr'.
+
+
+File: gdb.info, Node: PowerPC Features, Next: TIC6x Features, Prev: M68K Features, Up: Standard Target Features
+
+G.4.5 PowerPC Features
+----------------------
+
+The `org.gnu.gdb.power.core' feature is required for PowerPC targets.
+It should contain registers `r0' through `r31', `pc', `msr', `cr',
+`lr', `ctr', and `xer'. They may be 32-bit or 64-bit depending on the
+target.
+
+ The `org.gnu.gdb.power.fpu' feature is optional. It should contain
+registers `f0' through `f31' and `fpscr'.
+
+ The `org.gnu.gdb.power.altivec' feature is optional. It should
+contain registers `vr0' through `vr31', `vscr', and `vrsave'.
+
+ The `org.gnu.gdb.power.vsx' feature is optional. It should contain
+registers `vs0h' through `vs31h'. GDB will combine these registers
+with the floating point registers (`f0' through `f31') and the altivec
+registers (`vr0' through `vr31') to present the 128-bit wide registers
+`vs0' through `vs63', the set of vector registers for POWER7.
+
+ The `org.gnu.gdb.power.spe' feature is optional. It should contain
+registers `ev0h' through `ev31h', `acc', and `spefscr'. SPE targets
+should provide 32-bit registers in `org.gnu.gdb.power.core' and provide
+the upper halves in `ev0h' through `ev31h'. GDB will combine these to
+present registers `ev0' through `ev31' to the user.
+
+
+File: gdb.info, Node: TIC6x Features, Prev: PowerPC Features, Up: Standard Target Features
+
+G.4.6 TMS320C6x Features
+------------------------
+
+The `org.gnu.gdb.tic6x.core' feature is required for TMS320C6x targets.
+It should contain registers `A0' through `A15', registers `B0' through
+`B15', `CSR' and `PC'.
+
+ The `org.gnu.gdb.tic6x.gp' feature is optional. It should contain
+registers `A16' through `A31' and `B16' through `B31'.
+
+ The `org.gnu.gdb.tic6x.c6xp' feature is optional. It should contain
+registers `TSR', `ILC' and `RILC'.
+
+
+File: gdb.info, Node: Operating System Information, Next: Trace File Format, Prev: Target Descriptions, Up: Top
+
+Appendix H Operating System Information
+***************************************
+
+* Menu:
+
+* Process list::
+
+ Users of GDB often wish to obtain information about the state of the
+operating system running on the target--for example the list of
+processes, or the list of open files. This section describes the
+mechanism that makes it possible. This mechanism is similar to the
+target features mechanism (*note Target Descriptions::), but focuses on
+a different aspect of target.
+
+ Operating system information is retrived from the target via the
+remote protocol, using `qXfer' requests (*note qXfer osdata read::).
+The object name in the request should be `osdata', and the ANNEX
+identifies the data to be fetched.
+
+
+File: gdb.info, Node: Process list, Up: Operating System Information
+
+H.1 Process list
+================
+
+When requesting the process list, the ANNEX field in the `qXfer'
+request should be `processes'. The returned data is an XML document.
+The formal syntax of this document is defined in
+`gdb/features/osdata.dtd'.
+
+ An example document is:
+
+ <?xml version="1.0"?>
+ <!DOCTYPE target SYSTEM "osdata.dtd">
+ <osdata type="processes">
+ <item>
+ <column name="pid">1</column>
+ <column name="user">root</column>
+ <column name="command">/sbin/init</column>
+ <column name="cores">1,2,3</column>
+ </item>
+ </osdata>
+
+ Each item should include a column whose name is `pid'. The value of
+that column should identify the process on the target. The `user' and
+`command' columns are optional, and will be displayed by GDB. The
+`cores' column, if present, should contain a comma-separated list of
+cores that this process is running on. Target may provide additional
+columns, which GDB currently ignores.
+
+
+File: gdb.info, Node: Trace File Format, Next: Index Section Format, Prev: Operating System Information, Up: Top
+
+Appendix I Trace File Format
+****************************
+
+The trace file comes in three parts: a header, a textual description
+section, and a trace frame section with binary data.
+
+ The header has the form `\x7fTRACE0\n'. The first byte is `0x7f' so
+as to indicate that the file contains binary data, while the `0' is a
+version number that may have different values in the future.
+
+ The description section consists of multiple lines of ASCII text
+separated by newline characters (`0xa'). The lines may include a
+variety of optional descriptive or context-setting information, such as
+tracepoint definitions or register set size. GDB will ignore any line
+that it does not recognize. An empty line marks the end of this
+section.
+
+ The trace frame section consists of a number of consecutive frames.
+Each frame begins with a two-byte tracepoint number, followed by a
+four-byte size giving the amount of data in the frame. The data in the
+frame consists of a number of blocks, each introduced by a character
+indicating its type (at least register, memory, and trace state
+variable). The data in this section is raw binary, not a hexadecimal
+or other encoding; its endianness matches the target's endianness.
+
+`R BYTES'
+ Register block. The number and ordering of bytes matches that of a
+ `g' packet in the remote protocol. Note that these are the actual
+ bytes, in target order and GDB register order, not a hexadecimal
+ encoding.
+
+`M ADDRESS LENGTH BYTES...'
+ Memory block. This is a contiguous block of memory, at the 8-byte
+ address ADDRESS, with a 2-byte length LENGTH, followed by LENGTH
+ bytes.
+
+`V NUMBER VALUE'
+ Trace state variable block. This records the 8-byte signed value
+ VALUE of trace state variable numbered NUMBER.
+
+
+ Future enhancements of the trace file format may include additional
+types of blocks.
+
+
+File: gdb.info, Node: Index Section Format, Next: Copying, Prev: Trace File Format, Up: Top
+
+Appendix J `.gdb_index' section format
+**************************************
+
+This section documents the index section that is created by `save
+gdb-index' (*note Index Files::). The index section is DWARF-specific;
+some knowledge of DWARF is assumed in this description.
+
+ The mapped index file format is designed to be directly `mmap'able
+on any architecture. In most cases, a datum is represented using a
+little-endian 32-bit integer value, called an `offset_type'. Big
+endian machines must byte-swap the values before using them.
+Exceptions to this rule are noted. The data is laid out such that
+alignment is always respected.
+
+ A mapped index consists of several areas, laid out in order.
+
+ 1. The file header. This is a sequence of values, of `offset_type'
+ unless otherwise noted:
+
+ 1. The version number, currently 5. Versions 1, 2 and 3 are
+ obsolete. Version 4 differs by its hashing function.
+
+ 2. The offset, from the start of the file, of the CU list.
+
+ 3. The offset, from the start of the file, of the types CU list.
+ Note that this area can be empty, in which case this offset
+ will be equal to the next offset.
+
+ 4. The offset, from the start of the file, of the address area.
+
+ 5. The offset, from the start of the file, of the symbol table.
+
+ 6. The offset, from the start of the file, of the constant pool.
+
+ 2. The CU list. This is a sequence of pairs of 64-bit little-endian
+ values, sorted by the CU offset. The first element in each pair is
+ the offset of a CU in the `.debug_info' section. The second
+ element in each pair is the length of that CU. References to a CU
+ elsewhere in the map are done using a CU index, which is just the
+ 0-based index into this table. Note that if there are type CUs,
+ then conceptually CUs and type CUs form a single list for the
+ purposes of CU indices.
+
+ 3. The types CU list. This is a sequence of triplets of 64-bit
+ little-endian values. In a triplet, the first value is the CU
+ offset, the second value is the type offset in the CU, and the
+ third value is the type signature. The types CU list is not
+ sorted.
+
+ 4. The address area. The address area consists of a sequence of
+ address entries. Each address entry has three elements:
+
+ 1. The low address. This is a 64-bit little-endian value.
+
+ 2. The high address. This is a 64-bit little-endian value. Like
+ `DW_AT_high_pc', the value is one byte beyond the end.
+
+ 3. The CU index. This is an `offset_type' value.
+
+ 5. The symbol table. This is an open-addressed hash table. The size
+ of the hash table is always a power of 2.
+
+ Each slot in the hash table consists of a pair of `offset_type'
+ values. The first value is the offset of the symbol's name in the
+ constant pool. The second value is the offset of the CU vector in
+ the constant pool.
+
+ If both values are 0, then this slot in the hash table is empty.
+ This is ok because while 0 is a valid constant pool index, it
+ cannot be a valid index for both a string and a CU vector.
+
+ The hash value for a table entry is computed by applying an
+ iterative hash function to the symbol's name. Starting with an
+ initial value of `r = 0', each (unsigned) character `c' in the
+ string is incorporated into the hash using the formula depending
+ on the index version:
+
+ Version 4
+ The formula is `r = r * 67 + c - 113'.
+
+ Version 5
+ The formula is `r = r * 67 + tolower (c) - 113'.
+
+ The terminating `\0' is not incorporated into the hash.
+
+ The step size used in the hash table is computed via `((hash * 17)
+ & (size - 1)) | 1', where `hash' is the hash value, and `size' is
+ the size of the hash table. The step size is used to find the
+ next candidate slot when handling a hash collision.
+
+ The names of C++ symbols in the hash table are canonicalized. We
+ don't currently have a simple description of the canonicalization
+ algorithm; if you intend to create new index sections, you must
+ read the code.
+
+ 6. The constant pool. This is simply a bunch of bytes. It is
+ organized so that alignment is correct: CU vectors are stored
+ first, followed by strings.
+
+ A CU vector in the constant pool is a sequence of `offset_type'
+ values. The first value is the number of CU indices in the vector.
+ Each subsequent value is the index of a CU in the CU list. This
+ element in the hash table is used to indicate which CUs define the
+ symbol.
+
+ A string in the constant pool is zero-terminated.
+
+
+File: gdb.info, Node: Copying, Next: GNU Free Documentation License, Prev: Index Section Format, Up: Top
+
+Appendix K GNU GENERAL PUBLIC LICENSE
+*************************************
+
+ Version 3, 29 June 2007
+
+ Copyright (C) 2007 Free Software Foundation, Inc. `http://fsf.org/'
+
+ Everyone is permitted to copy and distribute verbatim copies of this
+ license document, but changing it is not allowed.
+
+Preamble
+========
+
+The GNU General Public License is a free, copyleft license for software
+and other kinds of works.
+
+ The licenses for most software and other practical works are designed
+to take away your freedom to share and change the works. By contrast,
+the GNU General Public License is intended to guarantee your freedom to
+share and change all versions of a program--to make sure it remains
+free software for all its users. We, the Free Software Foundation, use
+the GNU General Public License for most of our software; it applies
+also to any other work released this way by its authors. You can apply
+it to your programs, too.
+
+ When we speak of free software, we are referring to freedom, not
+price. Our General Public Licenses are designed to make sure that you
+have the freedom to distribute copies of free software (and charge for
+them if you wish), that you receive source code or can get it if you
+want it, that you can change the software or use pieces of it in new
+free programs, and that you know you can do these things.
+
+ To protect your rights, we need to prevent others from denying you
+these rights or asking you to surrender the rights. Therefore, you
+have certain responsibilities if you distribute copies of the software,
+or if you modify it: responsibilities to respect the freedom of others.
+
+ For example, if you distribute copies of such a program, whether
+gratis or for a fee, you must pass on to the recipients the same
+freedoms that you received. You must make sure that they, too, receive
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+
+ Developers that use the GNU GPL protect your rights with two steps:
+(1) assert copyright on the software, and (2) offer you this License
+giving you legal permission to copy, distribute and/or modify it.
+
+ For the developers' and authors' protection, the GPL clearly explains
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+
+ Some devices are designed to deny users access to install or run
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+
+ Finally, every program is threatened constantly by software patents.
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+ The precise terms and conditions for copying, distribution and
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+
+TERMS AND CONDITIONS
+====================
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+ conditions. Additional permissions that are applicable to the
+ entire Program shall be treated as though they were included in
+ this License, to the extent that they are valid under applicable
+ law. If additional permissions apply only to part of the Program,
+ that part may be used separately under those permissions, but the
+ entire Program remains governed by this License without regard to
+ the additional permissions.
+
+ When you convey a copy of a covered work, you may at your option
+ remove any additional permissions from that copy, or from any part
+ of it. (Additional permissions may be written to require their own
+ removal in certain cases when you modify the work.) You may place
+ additional permissions on material, added by you to a covered work,
+ for which you have or can give appropriate copyright permission.
+
+ Notwithstanding any other provision of this License, for material
+ you add to a covered work, you may (if authorized by the copyright
+ holders of that material) supplement the terms of this License
+ with terms:
+
+ a. Disclaiming warranty or limiting liability differently from
+ the terms of sections 15 and 16 of this License; or
+
+ b. Requiring preservation of specified reasonable legal notices
+ or author attributions in that material or in the Appropriate
+ Legal Notices displayed by works containing it; or
+
+ c. Prohibiting misrepresentation of the origin of that material,
+ or requiring that modified versions of such material be
+ marked in reasonable ways as different from the original
+ version; or
+
+ d. Limiting the use for publicity purposes of names of licensors
+ or authors of the material; or
+
+ e. Declining to grant rights under trademark law for use of some
+ trade names, trademarks, or service marks; or
+
+ f. Requiring indemnification of licensors and authors of that
+ material by anyone who conveys the material (or modified
+ versions of it) with contractual assumptions of liability to
+ the recipient, for any liability that these contractual
+ assumptions directly impose on those licensors and authors.
+
+ All other non-permissive additional terms are considered "further
+ restrictions" within the meaning of section 10. If the Program as
+ you received it, or any part of it, contains a notice stating that
+ it is governed by this License along with a term that is a further
+ restriction, you may remove that term. If a license document
+ contains a further restriction but permits relicensing or
+ conveying under this License, you may add to a covered work
+ material governed by the terms of that license document, provided
+ that the further restriction does not survive such relicensing or
+ conveying.
+
+ If you add terms to a covered work in accord with this section, you
+ must place, in the relevant source files, a statement of the
+ additional terms that apply to those files, or a notice indicating
+ where to find the applicable terms.
+
+ Additional terms, permissive or non-permissive, may be stated in
+ the form of a separately written license, or stated as exceptions;
+ the above requirements apply either way.
+
+ 8. Termination.
+
+ You may not propagate or modify a covered work except as expressly
+ provided under this License. Any attempt otherwise to propagate or
+ modify it is void, and will automatically terminate your rights
+ under this License (including any patent licenses granted under
+ the third paragraph of section 11).
+
+ However, if you cease all violation of this License, then your
+ license from a particular copyright holder is reinstated (a)
+ provisionally, unless and until the copyright holder explicitly
+ and finally terminates your license, and (b) permanently, if the
+ copyright holder fails to notify you of the violation by some
+ reasonable means prior to 60 days after the cessation.
+
+ Moreover, your license from a particular copyright holder is
+ reinstated permanently if the copyright holder notifies you of the
+ violation by some reasonable means, this is the first time you have
+ received notice of violation of this License (for any work) from
+ that copyright holder, and you cure the violation prior to 30 days
+ after your receipt of the notice.
+
+ Termination of your rights under this section does not terminate
+ the licenses of parties who have received copies or rights from
+ you under this License. If your rights have been terminated and
+ not permanently reinstated, you do not qualify to receive new
+ licenses for the same material under section 10.
+
+ 9. Acceptance Not Required for Having Copies.
+
+ You are not required to accept this License in order to receive or
+ run a copy of the Program. Ancillary propagation of a covered work
+ occurring solely as a consequence of using peer-to-peer
+ transmission to receive a copy likewise does not require
+ acceptance. However, nothing other than this License grants you
+ permission to propagate or modify any covered work. These actions
+ infringe copyright if you do not accept this License. Therefore,
+ by modifying or propagating a covered work, you indicate your
+ acceptance of this License to do so.
+
+ 10. Automatic Licensing of Downstream Recipients.
+
+ Each time you convey a covered work, the recipient automatically
+ receives a license from the original licensors, to run, modify and
+ propagate that work, subject to this License. You are not
+ responsible for enforcing compliance by third parties with this
+ License.
+
+ An "entity transaction" is a transaction transferring control of an
+ organization, or substantially all assets of one, or subdividing an
+ organization, or merging organizations. If propagation of a
+ covered work results from an entity transaction, each party to that
+ transaction who receives a copy of the work also receives whatever
+ licenses to the work the party's predecessor in interest had or
+ could give under the previous paragraph, plus a right to
+ possession of the Corresponding Source of the work from the
+ predecessor in interest, if the predecessor has it or can get it
+ with reasonable efforts.
+
+ You may not impose any further restrictions on the exercise of the
+ rights granted or affirmed under this License. For example, you
+ may not impose a license fee, royalty, or other charge for
+ exercise of rights granted under this License, and you may not
+ initiate litigation (including a cross-claim or counterclaim in a
+ lawsuit) alleging that any patent claim is infringed by making,
+ using, selling, offering for sale, or importing the Program or any
+ portion of it.
+
+ 11. Patents.
+
+ A "contributor" is a copyright holder who authorizes use under this
+ License of the Program or a work on which the Program is based.
+ The work thus licensed is called the contributor's "contributor
+ version".
+
+ A contributor's "essential patent claims" are all patent claims
+ owned or controlled by the contributor, whether already acquired or
+ hereafter acquired, that would be infringed by some manner,
+ permitted by this License, of making, using, or selling its
+ contributor version, but do not include claims that would be
+ infringed only as a consequence of further modification of the
+ contributor version. For purposes of this definition, "control"
+ includes the right to grant patent sublicenses in a manner
+ consistent with the requirements of this License.
+
+ Each contributor grants you a non-exclusive, worldwide,
+ royalty-free patent license under the contributor's essential
+ patent claims, to make, use, sell, offer for sale, import and
+ otherwise run, modify and propagate the contents of its
+ contributor version.
+
+ In the following three paragraphs, a "patent license" is any
+ express agreement or commitment, however denominated, not to
+ enforce a patent (such as an express permission to practice a
+ patent or covenant not to sue for patent infringement). To
+ "grant" such a patent license to a party means to make such an
+ agreement or commitment not to enforce a patent against the party.
+
+ If you convey a covered work, knowingly relying on a patent
+ license, and the Corresponding Source of the work is not available
+ for anyone to copy, free of charge and under the terms of this
+ License, through a publicly available network server or other
+ readily accessible means, then you must either (1) cause the
+ Corresponding Source to be so available, or (2) arrange to deprive
+ yourself of the benefit of the patent license for this particular
+ work, or (3) arrange, in a manner consistent with the requirements
+ of this License, to extend the patent license to downstream
+ recipients. "Knowingly relying" means you have actual knowledge
+ that, but for the patent license, your conveying the covered work
+ in a country, or your recipient's use of the covered work in a
+ country, would infringe one or more identifiable patents in that
+ country that you have reason to believe are valid.
+
+ If, pursuant to or in connection with a single transaction or
+ arrangement, you convey, or propagate by procuring conveyance of, a
+ covered work, and grant a patent license to some of the parties
+ receiving the covered work authorizing them to use, propagate,
+ modify or convey a specific copy of the covered work, then the
+ patent license you grant is automatically extended to all
+ recipients of the covered work and works based on it.
+
+ A patent license is "discriminatory" if it does not include within
+ the scope of its coverage, prohibits the exercise of, or is
+ conditioned on the non-exercise of one or more of the rights that
+ are specifically granted under this License. You may not convey a
+ covered work if you are a party to an arrangement with a third
+ party that is in the business of distributing software, under
+ which you make payment to the third party based on the extent of
+ your activity of conveying the work, and under which the third
+ party grants, to any of the parties who would receive the covered
+ work from you, a discriminatory patent license (a) in connection
+ with copies of the covered work conveyed by you (or copies made
+ from those copies), or (b) primarily for and in connection with
+ specific products or compilations that contain the covered work,
+ unless you entered into that arrangement, or that patent license
+ was granted, prior to 28 March 2007.
+
+ Nothing in this License shall be construed as excluding or limiting
+ any implied license or other defenses to infringement that may
+ otherwise be available to you under applicable patent law.
+
+ 12. No Surrender of Others' Freedom.
+
+ If conditions are imposed on you (whether by court order,
+ agreement or otherwise) that contradict the conditions of this
+ License, they do not excuse you from the conditions of this
+ License. If you cannot convey a covered work so as to satisfy
+ simultaneously your obligations under this License and any other
+ pertinent obligations, then as a consequence you may not convey it
+ at all. For example, if you agree to terms that obligate you to
+ collect a royalty for further conveying from those to whom you
+ convey the Program, the only way you could satisfy both those
+ terms and this License would be to refrain entirely from conveying
+ the Program.
+
+ 13. Use with the GNU Affero General Public License.
+
+ Notwithstanding any other provision of this License, you have
+ permission to link or combine any covered work with a work licensed
+ under version 3 of the GNU Affero General Public License into a
+ single combined work, and to convey the resulting work. The terms
+ of this License will continue to apply to the part which is the
+ covered work, but the special requirements of the GNU Affero
+ General Public License, section 13, concerning interaction through
+ a network will apply to the combination as such.
+
+ 14. Revised Versions of this License.
+
+ The Free Software Foundation may publish revised and/or new
+ versions of the GNU General Public License from time to time.
+ Such new versions will be similar in spirit to the present
+ version, but may differ in detail to address new problems or
+ concerns.
+
+ Each version is given a distinguishing version number. If the
+ Program specifies that a certain numbered version of the GNU
+ General Public License "or any later version" applies to it, you
+ have the option of following the terms and conditions either of
+ that numbered version or of any later version published by the
+ Free Software Foundation. If the Program does not specify a
+ version number of the GNU General Public License, you may choose
+ any version ever published by the Free Software Foundation.
+
+ If the Program specifies that a proxy can decide which future
+ versions of the GNU General Public License can be used, that
+ proxy's public statement of acceptance of a version permanently
+ authorizes you to choose that version for the Program.
+
+ Later license versions may give you additional or different
+ permissions. However, no additional obligations are imposed on any
+ author or copyright holder as a result of your choosing to follow a
+ later version.
+
+ 15. Disclaimer of Warranty.
+
+ THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
+ APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE
+ COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS"
+ WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED,
+ INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE
+ RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU.
+ SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL
+ NECESSARY SERVICING, REPAIR OR CORRECTION.
+
+ 16. Limitation of Liability.
+
+ IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN
+ WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES
+ AND/OR CONVEYS THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU
+ FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR
+ CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE
+ THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA
+ BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
+ PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER
+ PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF
+ THE POSSIBILITY OF SUCH DAMAGES.
+
+ 17. Interpretation of Sections 15 and 16.
+
+ If the disclaimer of warranty and limitation of liability provided
+ above cannot be given local legal effect according to their terms,
+ reviewing courts shall apply local law that most closely
+ approximates an absolute waiver of all civil liability in
+ connection with the Program, unless a warranty or assumption of
+ liability accompanies a copy of the Program in return for a fee.
+
+
+END OF TERMS AND CONDITIONS
+===========================
+
+How to Apply These Terms to Your New Programs
+=============================================
+
+If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these
+terms.
+
+ To do so, attach the following notices to the program. It is safest
+to attach them to the start of each source file to most effectively
+state the exclusion of warranty; and each file should have at least the
+"copyright" line and a pointer to where the full notice is found.
+
+ ONE LINE TO GIVE THE PROGRAM'S NAME AND A BRIEF IDEA OF WHAT IT DOES.
+ Copyright (C) YEAR NAME OF AUTHOR
+
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or (at
+ your option) any later version.
+
+ This program is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see `http://www.gnu.org/licenses/'.
+
+ Also add information on how to contact you by electronic and paper
+mail.
+
+ If the program does terminal interaction, make it output a short
+notice like this when it starts in an interactive mode:
+
+ PROGRAM Copyright (C) YEAR NAME OF AUTHOR
+ This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
+ This is free software, and you are welcome to redistribute it
+ under certain conditions; type `show c' for details.
+
+ The hypothetical commands `show w' and `show c' should show the
+appropriate parts of the General Public License. Of course, your
+program's commands might be different; for a GUI interface, you would
+use an "about box".
+
+ You should also get your employer (if you work as a programmer) or
+school, if any, to sign a "copyright disclaimer" for the program, if
+necessary. For more information on this, and how to apply and follow
+the GNU GPL, see `http://www.gnu.org/licenses/'.
+
+ The GNU General Public License does not permit incorporating your
+program into proprietary programs. If your program is a subroutine
+library, you may consider it more useful to permit linking proprietary
+applications with the library. If this is what you want to do, use the
+GNU Lesser General Public License instead of this License. But first,
+please read `http://www.gnu.org/philosophy/why-not-lgpl.html'.
+
+
+File: gdb.info, Node: GNU Free Documentation License, Next: Index, Prev: Copying, Up: Top
+
+Appendix L GNU Free Documentation License
+*****************************************
+
+ Version 1.3, 3 November 2008
+
+ Copyright (C) 2000, 2001, 2002, 2007, 2008 Free Software Foundation, Inc.
+ `http://fsf.org/'
+
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+ 0. PREAMBLE
+
+ The purpose of this License is to make a manual, textbook, or other
+ functional and useful document "free" in the sense of freedom: to
+ assure everyone the effective freedom to copy and redistribute it,
+ with or without modifying it, either commercially or
+ noncommercially. Secondarily, this License preserves for the
+ author and publisher a way to get credit for their work, while not
+ being considered responsible for modifications made by others.
+
+ This License is a kind of "copyleft", which means that derivative
+ works of the document must themselves be free in the same sense.
+ It complements the GNU General Public License, which is a copyleft
+ license designed for free software.
+
+ We have designed this License in order to use it for manuals for
+ free software, because free software needs free documentation: a
+ free program should come with manuals providing the same freedoms
+ that the software does. But this License is not limited to
+ software manuals; it can be used for any textual work, regardless
+ of subject matter or whether it is published as a printed book.
+ We recommend this License principally for works whose purpose is
+ instruction or reference.
+
+ 1. APPLICABILITY AND DEFINITIONS
+
+ This License applies to any manual or other work, in any medium,
+ that contains a notice placed by the copyright holder saying it
+ can be distributed under the terms of this License. Such a notice
+ grants a world-wide, royalty-free license, unlimited in duration,
+ to use that work under the conditions stated herein. The
+ "Document", below, refers to any such manual or work. Any member
+ of the public is a licensee, and is addressed as "you". You
+ accept the license if you copy, modify or distribute the work in a
+ way requiring permission under copyright law.
+
+ A "Modified Version" of the Document means any work containing the
+ Document or a portion of it, either copied verbatim, or with
+ modifications and/or translated into another language.
+
+ A "Secondary Section" is a named appendix or a front-matter section
+ of the Document that deals exclusively with the relationship of the
+ publishers or authors of the Document to the Document's overall
+ subject (or to related matters) and contains nothing that could
+ fall directly within that overall subject. (Thus, if the Document
+ is in part a textbook of mathematics, a Secondary Section may not
+ explain any mathematics.) The relationship could be a matter of
+ historical connection with the subject or with related matters, or
+ of legal, commercial, philosophical, ethical or political position
+ regarding them.
+
+ The "Invariant Sections" are certain Secondary Sections whose
+ titles are designated, as being those of Invariant Sections, in
+ the notice that says that the Document is released under this
+ License. If a section does not fit the above definition of
+ Secondary then it is not allowed to be designated as Invariant.
+ The Document may contain zero Invariant Sections. If the Document
+ does not identify any Invariant Sections then there are none.
+
+ The "Cover Texts" are certain short passages of text that are
+ listed, as Front-Cover Texts or Back-Cover Texts, in the notice
+ that says that the Document is released under this License. A
+ Front-Cover Text may be at most 5 words, and a Back-Cover Text may
+ be at most 25 words.
+
+ A "Transparent" copy of the Document means a machine-readable copy,
+ represented in a format whose specification is available to the
+ general public, that is suitable for revising the document
+ straightforwardly with generic text editors or (for images
+ composed of pixels) generic paint programs or (for drawings) some
+ widely available drawing editor, and that is suitable for input to
+ text formatters or for automatic translation to a variety of
+ formats suitable for input to text formatters. A copy made in an
+ otherwise Transparent file format whose markup, or absence of
+ markup, has been arranged to thwart or discourage subsequent
+ modification by readers is not Transparent. An image format is
+ not Transparent if used for any substantial amount of text. A
+ copy that is not "Transparent" is called "Opaque".
+
+ Examples of suitable formats for Transparent copies include plain
+ ASCII without markup, Texinfo input format, LaTeX input format,
+ SGML or XML using a publicly available DTD, and
+ standard-conforming simple HTML, PostScript or PDF designed for
+ human modification. Examples of transparent image formats include
+ PNG, XCF and JPG. Opaque formats include proprietary formats that
+ can be read and edited only by proprietary word processors, SGML or
+ XML for which the DTD and/or processing tools are not generally
+ available, and the machine-generated HTML, PostScript or PDF
+ produced by some word processors for output purposes only.
+
+ The "Title Page" means, for a printed book, the title page itself,
+ plus such following pages as are needed to hold, legibly, the
+ material this License requires to appear in the title page. For
+ works in formats which do not have any title page as such, "Title
+ Page" means the text near the most prominent appearance of the
+ work's title, preceding the beginning of the body of the text.
+
+ The "publisher" means any person or entity that distributes copies
+ of the Document to the public.
+
+ A section "Entitled XYZ" means a named subunit of the Document
+ whose title either is precisely XYZ or contains XYZ in parentheses
+ following text that translates XYZ in another language. (Here XYZ
+ stands for a specific section name mentioned below, such as
+ "Acknowledgements", "Dedications", "Endorsements", or "History".)
+ To "Preserve the Title" of such a section when you modify the
+ Document means that it remains a section "Entitled XYZ" according
+ to this definition.
+
+ The Document may include Warranty Disclaimers next to the notice
+ which states that this License applies to the Document. These
+ Warranty Disclaimers are considered to be included by reference in
+ this License, but only as regards disclaiming warranties: any other
+ implication that these Warranty Disclaimers may have is void and
+ has no effect on the meaning of this License.
+
+ 2. VERBATIM COPYING
+
+ You may copy and distribute the Document in any medium, either
+ commercially or noncommercially, provided that this License, the
+ copyright notices, and the license notice saying this License
+ applies to the Document are reproduced in all copies, and that you
+ add no other conditions whatsoever to those of this License. You
+ may not use technical measures to obstruct or control the reading
+ or further copying of the copies you make or distribute. However,
+ you may accept compensation in exchange for copies. If you
+ distribute a large enough number of copies you must also follow
+ the conditions in section 3.
+
+ You may also lend copies, under the same conditions stated above,
+ and you may publicly display copies.
+
+ 3. COPYING IN QUANTITY
+
+ If you publish printed copies (or copies in media that commonly
+ have printed covers) of the Document, numbering more than 100, and
+ the Document's license notice requires Cover Texts, you must
+ enclose the copies in covers that carry, clearly and legibly, all
+ these Cover Texts: Front-Cover Texts on the front cover, and
+ Back-Cover Texts on the back cover. Both covers must also clearly
+ and legibly identify you as the publisher of these copies. The
+ front cover must present the full title with all words of the
+ title equally prominent and visible. You may add other material
+ on the covers in addition. Copying with changes limited to the
+ covers, as long as they preserve the title of the Document and
+ satisfy these conditions, can be treated as verbatim copying in
+ other respects.
+
+ If the required texts for either cover are too voluminous to fit
+ legibly, you should put the first ones listed (as many as fit
+ reasonably) on the actual cover, and continue the rest onto
+ adjacent pages.
+
+ If you publish or distribute Opaque copies of the Document
+ numbering more than 100, you must either include a
+ machine-readable Transparent copy along with each Opaque copy, or
+ state in or with each Opaque copy a computer-network location from
+ which the general network-using public has access to download
+ using public-standard network protocols a complete Transparent
+ copy of the Document, free of added material. If you use the
+ latter option, you must take reasonably prudent steps, when you
+ begin distribution of Opaque copies in quantity, to ensure that
+ this Transparent copy will remain thus accessible at the stated
+ location until at least one year after the last time you
+ distribute an Opaque copy (directly or through your agents or
+ retailers) of that edition to the public.
+
+ It is requested, but not required, that you contact the authors of
+ the Document well before redistributing any large number of
+ copies, to give them a chance to provide you with an updated
+ version of the Document.
+
+ 4. MODIFICATIONS
+
+ You may copy and distribute a Modified Version of the Document
+ under the conditions of sections 2 and 3 above, provided that you
+ release the Modified Version under precisely this License, with
+ the Modified Version filling the role of the Document, thus
+ licensing distribution and modification of the Modified Version to
+ whoever possesses a copy of it. In addition, you must do these
+ things in the Modified Version:
+
+ A. Use in the Title Page (and on the covers, if any) a title
+ distinct from that of the Document, and from those of
+ previous versions (which should, if there were any, be listed
+ in the History section of the Document). You may use the
+ same title as a previous version if the original publisher of
+ that version gives permission.
+
+ B. List on the Title Page, as authors, one or more persons or
+ entities responsible for authorship of the modifications in
+ the Modified Version, together with at least five of the
+ principal authors of the Document (all of its principal
+ authors, if it has fewer than five), unless they release you
+ from this requirement.
+
+ C. State on the Title page the name of the publisher of the
+ Modified Version, as the publisher.
+
+ D. Preserve all the copyright notices of the Document.
+
+ E. Add an appropriate copyright notice for your modifications
+ adjacent to the other copyright notices.
+
+ F. Include, immediately after the copyright notices, a license
+ notice giving the public permission to use the Modified
+ Version under the terms of this License, in the form shown in
+ the Addendum below.
+
+ G. Preserve in that license notice the full lists of Invariant
+ Sections and required Cover Texts given in the Document's
+ license notice.
+
+ H. Include an unaltered copy of this License.
+
+ I. Preserve the section Entitled "History", Preserve its Title,
+ and add to it an item stating at least the title, year, new
+ authors, and publisher of the Modified Version as given on
+ the Title Page. If there is no section Entitled "History" in
+ the Document, create one stating the title, year, authors,
+ and publisher of the Document as given on its Title Page,
+ then add an item describing the Modified Version as stated in
+ the previous sentence.
+
+ J. Preserve the network location, if any, given in the Document
+ for public access to a Transparent copy of the Document, and
+ likewise the network locations given in the Document for
+ previous versions it was based on. These may be placed in
+ the "History" section. You may omit a network location for a
+ work that was published at least four years before the
+ Document itself, or if the original publisher of the version
+ it refers to gives permission.
+
+ K. For any section Entitled "Acknowledgements" or "Dedications",
+ Preserve the Title of the section, and preserve in the
+ section all the substance and tone of each of the contributor
+ acknowledgements and/or dedications given therein.
+
+ L. Preserve all the Invariant Sections of the Document,
+ unaltered in their text and in their titles. Section numbers
+ or the equivalent are not considered part of the section
+ titles.
+
+ M. Delete any section Entitled "Endorsements". Such a section
+ may not be included in the Modified Version.
+
+ N. Do not retitle any existing section to be Entitled
+ "Endorsements" or to conflict in title with any Invariant
+ Section.
+
+ O. Preserve any Warranty Disclaimers.
+
+ If the Modified Version includes new front-matter sections or
+ appendices that qualify as Secondary Sections and contain no
+ material copied from the Document, you may at your option
+ designate some or all of these sections as invariant. To do this,
+ add their titles to the list of Invariant Sections in the Modified
+ Version's license notice. These titles must be distinct from any
+ other section titles.
+
+ You may add a section Entitled "Endorsements", provided it contains
+ nothing but endorsements of your Modified Version by various
+ parties--for example, statements of peer review or that the text
+ has been approved by an organization as the authoritative
+ definition of a standard.
+
+ You may add a passage of up to five words as a Front-Cover Text,
+ and a passage of up to 25 words as a Back-Cover Text, to the end
+ of the list of Cover Texts in the Modified Version. Only one
+ passage of Front-Cover Text and one of Back-Cover Text may be
+ added by (or through arrangements made by) any one entity. If the
+ Document already includes a cover text for the same cover,
+ previously added by you or by arrangement made by the same entity
+ you are acting on behalf of, you may not add another; but you may
+ replace the old one, on explicit permission from the previous
+ publisher that added the old one.
+
+ The author(s) and publisher(s) of the Document do not by this
+ License give permission to use their names for publicity for or to
+ assert or imply endorsement of any Modified Version.
+
+ 5. COMBINING DOCUMENTS
+
+ You may combine the Document with other documents released under
+ this License, under the terms defined in section 4 above for
+ modified versions, provided that you include in the combination
+ all of the Invariant Sections of all of the original documents,
+ unmodified, and list them all as Invariant Sections of your
+ combined work in its license notice, and that you preserve all
+ their Warranty Disclaimers.
+
+ The combined work need only contain one copy of this License, and
+ multiple identical Invariant Sections may be replaced with a single
+ copy. If there are multiple Invariant Sections with the same name
+ but different contents, make the title of each such section unique
+ by adding at the end of it, in parentheses, the name of the
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+ unique number. Make the same adjustment to the section titles in
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+ In the combination, you must combine any sections Entitled
+ "History" in the various original documents, forming one section
+ Entitled "History"; likewise combine any sections Entitled
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+ must delete all sections Entitled "Endorsements."
+
+ 6. COLLECTIONS OF DOCUMENTS
+
+ You may make a collection consisting of the Document and other
+ documents released under this License, and replace the individual
+ copies of this License in the various documents with a single copy
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+ rules of this License for verbatim copying of each of the
+ documents in all other respects.
+
+ You may extract a single document from such a collection, and
+ distribute it individually under this License, provided you insert
+ a copy of this License into the extracted document, and follow
+ this License in all other respects regarding verbatim copying of
+ that document.
+
+ 7. AGGREGATION WITH INDEPENDENT WORKS
+
+ A compilation of the Document or its derivatives with other
+ separate and independent documents or works, in or on a volume of
+ a storage or distribution medium, is called an "aggregate" if the
+ copyright resulting from the compilation is not used to limit the
+ legal rights of the compilation's users beyond what the individual
+ works permit. When the Document is included in an aggregate, this
+ License does not apply to the other works in the aggregate which
+ are not themselves derivative works of the Document.
+
+ If the Cover Text requirement of section 3 is applicable to these
+ copies of the Document, then if the Document is less than one half
+ of the entire aggregate, the Document's Cover Texts may be placed
+ on covers that bracket the Document within the aggregate, or the
+ electronic equivalent of covers if the Document is in electronic
+ form. Otherwise they must appear on printed covers that bracket
+ the whole aggregate.
+
+ 8. TRANSLATION
+
+ Translation is considered a kind of modification, so you may
+ distribute translations of the Document under the terms of section
+ 4. Replacing Invariant Sections with translations requires special
+ permission from their copyright holders, but you may include
+ translations of some or all Invariant Sections in addition to the
+ original versions of these Invariant Sections. You may include a
+ translation of this License, and all the license notices in the
+ Document, and any Warranty Disclaimers, provided that you also
+ include the original English version of this License and the
+ original versions of those notices and disclaimers. In case of a
+ disagreement between the translation and the original version of
+ this License or a notice or disclaimer, the original version will
+ prevail.
+
+ If a section in the Document is Entitled "Acknowledgements",
+ "Dedications", or "History", the requirement (section 4) to
+ Preserve its Title (section 1) will typically require changing the
+ actual title.
+
+ 9. TERMINATION
+
+ You may not copy, modify, sublicense, or distribute the Document
+ except as expressly provided under this License. Any attempt
+ otherwise to copy, modify, sublicense, or distribute it is void,
+ and will automatically terminate your rights under this License.
+
+ However, if you cease all violation of this License, then your
+ license from a particular copyright holder is reinstated (a)
+ provisionally, unless and until the copyright holder explicitly
+ and finally terminates your license, and (b) permanently, if the
+ copyright holder fails to notify you of the violation by some
+ reasonable means prior to 60 days after the cessation.
+
+ Moreover, your license from a particular copyright holder is
+ reinstated permanently if the copyright holder notifies you of the
+ violation by some reasonable means, this is the first time you have
+ received notice of violation of this License (for any work) from
+ that copyright holder, and you cure the violation prior to 30 days
+ after your receipt of the notice.
+
+ Termination of your rights under this section does not terminate
+ the licenses of parties who have received copies or rights from
+ you under this License. If your rights have been terminated and
+ not permanently reinstated, receipt of a copy of some or all of
+ the same material does not give you any rights to use it.
+
+ 10. FUTURE REVISIONS OF THIS LICENSE
+
+ The Free Software Foundation may publish new, revised versions of
+ the GNU Free Documentation License from time to time. Such new
+ versions will be similar in spirit to the present version, but may
+ differ in detail to address new problems or concerns. See
+ `http://www.gnu.org/copyleft/'.
+
+ Each version of the License is given a distinguishing version
+ number. If the Document specifies that a particular numbered
+ version of this License "or any later version" applies to it, you
+ have the option of following the terms and conditions either of
+ that specified version or of any later version that has been
+ published (not as a draft) by the Free Software Foundation. If
+ the Document does not specify a version number of this License,
+ you may choose any version ever published (not as a draft) by the
+ Free Software Foundation. If the Document specifies that a proxy
+ can decide which future versions of this License can be used, that
+ proxy's public statement of acceptance of a version permanently
+ authorizes you to choose that version for the Document.
+
+ 11. RELICENSING
+
+ "Massive Multiauthor Collaboration Site" (or "MMC Site") means any
+ World Wide Web server that publishes copyrightable works and also
+ provides prominent facilities for anybody to edit those works. A
+ public wiki that anybody can edit is an example of such a server.
+ A "Massive Multiauthor Collaboration" (or "MMC") contained in the
+ site means any set of copyrightable works thus published on the MMC
+ site.
+
+ "CC-BY-SA" means the Creative Commons Attribution-Share Alike 3.0
+ license published by Creative Commons Corporation, a not-for-profit
+ corporation with a principal place of business in San Francisco,
+ California, as well as future copyleft versions of that license
+ published by that same organization.
+
+ "Incorporate" means to publish or republish a Document, in whole or
+ in part, as part of another Document.
+
+ An MMC is "eligible for relicensing" if it is licensed under this
+ License, and if all works that were first published under this
+ License somewhere other than this MMC, and subsequently
+ incorporated in whole or in part into the MMC, (1) had no cover
+ texts or invariant sections, and (2) were thus incorporated prior
+ to November 1, 2008.
+
+ The operator of an MMC Site may republish an MMC contained in the
+ site under CC-BY-SA on the same site at any time before August 1,
+ 2009, provided the MMC is eligible for relicensing.
+
+
+ADDENDUM: How to use this License for your documents
+====================================================
+
+To use this License in a document you have written, include a copy of
+the License in the document and put the following copyright and license
+notices just after the title page:
+
+ Copyright (C) YEAR YOUR NAME.
+ Permission is granted to copy, distribute and/or modify this document
+ under the terms of the GNU Free Documentation License, Version 1.3
+ or any later version published by the Free Software Foundation;
+ with no Invariant Sections, no Front-Cover Texts, and no Back-Cover
+ Texts. A copy of the license is included in the section entitled ``GNU
+ Free Documentation License''.
+
+ If you have Invariant Sections, Front-Cover Texts and Back-Cover
+Texts, replace the "with...Texts." line with this:
+
+ with the Invariant Sections being LIST THEIR TITLES, with
+ the Front-Cover Texts being LIST, and with the Back-Cover Texts
+ being LIST.
+
+ If you have Invariant Sections without Cover Texts, or some other
+combination of the three, merge those two alternatives to suit the
+situation.
+
+ If your document contains nontrivial examples of program code, we
+recommend releasing these examples in parallel under your choice of
+free software license, such as the GNU General Public License, to
+permit their use in free software.
+
diff --git a/gdb/doc/gdb.info-6 b/gdb/doc/gdb.info-6
new file mode 100644
index 0000000..96eb818
--- /dev/null
+++ b/gdb/doc/gdb.info-6
Binary files differ
diff --git a/gdb/doc/gdbint.info b/gdb/doc/gdbint.info
index 456ef6f..d3fa773 100644
--- a/gdb/doc/gdbint.info
+++ b/gdb/doc/gdbint.info
Binary files differ
diff --git a/gdb/doc/gdbint.info-1 b/gdb/doc/gdbint.info-1
new file mode 100644
index 0000000..190fe35
--- /dev/null
+++ b/gdb/doc/gdbint.info-1
Binary files differ
diff --git a/gdb/doc/gdbint.info-2 b/gdb/doc/gdbint.info-2
new file mode 100644
index 0000000..0238b35
--- /dev/null
+++ b/gdb/doc/gdbint.info-2
Binary files differ
diff --git a/gdb/i387-tdep.c b/gdb/i387-tdep.c
index 450b8f2..d2ff9e5 100644
--- a/gdb/i387-tdep.c
+++ b/gdb/i387-tdep.c
@@ -725,6 +725,7 @@
const gdb_byte *regs = xsave;
int i;
unsigned int clear_bv;
+ static const gdb_byte zero[MAX_REGISTER_SIZE] = { 0 };
const gdb_byte *p;
enum
{
@@ -764,6 +765,19 @@
else
clear_bv = I386_XSTATE_AVX_MASK;
+ /* With the delayed xsave mechanism, in between the program
+ starting, and the program accessing the vector registers for the
+ first time, the register's values are invalid. The kernel
+ initializes register states to zero when they are set the first
+ time in a program. This means that from the user-space programs'
+ perspective, it's the same as if the registers have always been
+ zero from the start of the program. Therefore, the debugger
+ should provide the same illusion to the user.
+
+ Note however, the case when REGS is NULL is a different case.
+ That case means we do not have access to the x87 states, so we
+ should mark the registers as unavailable (by supplying NULL). */
+
switch (regclass)
{
case none:
@@ -771,26 +785,26 @@
case avxh:
if ((clear_bv & I386_XSTATE_AVX))
- p = NULL;
+ regcache_raw_supply (regcache, regnum, regs == NULL ? NULL : zero);
else
- p = XSAVE_AVXH_ADDR (tdep, regs, regnum);
- regcache_raw_supply (regcache, regnum, p);
+ regcache_raw_supply (regcache, regnum,
+ XSAVE_AVXH_ADDR (tdep, regs, regnum));
return;
case sse:
if ((clear_bv & I386_XSTATE_SSE))
- p = NULL;
+ regcache_raw_supply (regcache, regnum, regs == NULL ? NULL : zero);
else
- p = FXSAVE_ADDR (tdep, regs, regnum);
- regcache_raw_supply (regcache, regnum, p);
+ regcache_raw_supply (regcache, regnum,
+ FXSAVE_ADDR (tdep, regs, regnum));
return;
case x87:
if ((clear_bv & I386_XSTATE_X87))
- p = NULL;
+ regcache_raw_supply (regcache, regnum, regs == NULL ? NULL : zero);
else
- p = FXSAVE_ADDR (tdep, regs, regnum);
- regcache_raw_supply (regcache, regnum, p);
+ regcache_raw_supply (regcache, regnum,
+ FXSAVE_ADDR (tdep, regs, regnum));
return;
case all:
@@ -798,16 +812,19 @@
if ((tdep->xcr0 & I386_XSTATE_AVX))
{
if ((clear_bv & I386_XSTATE_AVX))
- p = NULL;
- else
- p = regs;
-
- for (i = I387_YMM0H_REGNUM (tdep);
- i < I387_YMMENDH_REGNUM (tdep); i++)
{
- if (p != NULL)
- p = XSAVE_AVXH_ADDR (tdep, regs, i);
- regcache_raw_supply (regcache, i, p);
+ for (i = I387_YMM0H_REGNUM (tdep);
+ i < I387_YMMENDH_REGNUM (tdep);
+ i++)
+ regcache_raw_supply (regcache, i, regs == NULL ? NULL : zero);
+ }
+ else
+ {
+ for (i = I387_YMM0H_REGNUM (tdep);
+ i < I387_YMMENDH_REGNUM (tdep);
+ i++)
+ regcache_raw_supply (regcache, i,
+ XSAVE_AVXH_ADDR (tdep, regs, i));
}
}
@@ -815,16 +832,18 @@
if ((tdep->xcr0 & I386_XSTATE_SSE))
{
if ((clear_bv & I386_XSTATE_SSE))
- p = NULL;
- else
- p = regs;
-
- for (i = I387_XMM0_REGNUM (tdep);
- i < I387_MXCSR_REGNUM (tdep); i++)
{
- if (p != NULL)
- p = FXSAVE_ADDR (tdep, regs, i);
- regcache_raw_supply (regcache, i, p);
+ for (i = I387_XMM0_REGNUM (tdep);
+ i < I387_MXCSR_REGNUM (tdep);
+ i++)
+ regcache_raw_supply (regcache, i, regs == NULL ? NULL : zero);
+ }
+ else
+ {
+ for (i = I387_XMM0_REGNUM (tdep);
+ i < I387_MXCSR_REGNUM (tdep); i++)
+ regcache_raw_supply (regcache, i,
+ FXSAVE_ADDR (tdep, regs, i));
}
}
@@ -832,16 +851,18 @@
if ((tdep->xcr0 & I386_XSTATE_X87))
{
if ((clear_bv & I386_XSTATE_X87))
- p = NULL;
- else
- p = regs;
-
- for (i = I387_ST0_REGNUM (tdep);
- i < I387_FCTRL_REGNUM (tdep); i++)
{
- if (p != NULL)
- p = FXSAVE_ADDR (tdep, regs, i);
- regcache_raw_supply (regcache, i, p);
+ for (i = I387_ST0_REGNUM (tdep);
+ i < I387_FCTRL_REGNUM (tdep);
+ i++)
+ regcache_raw_supply (regcache, i, regs == NULL ? NULL : zero);
+ }
+ else
+ {
+ for (i = I387_ST0_REGNUM (tdep);
+ i < I387_FCTRL_REGNUM (tdep);
+ i++)
+ regcache_raw_supply (regcache, i, FXSAVE_ADDR (tdep, regs, i));
}
}
break;
diff --git a/gdb/infcmd.c b/gdb/infcmd.c
index 75dc55b..4b31c98 100644
--- a/gdb/infcmd.c
+++ b/gdb/infcmd.c
@@ -1636,6 +1636,7 @@
static void
finish_forward (struct symbol *function, struct frame_info *frame)
{
+ struct frame_id frame_id = get_frame_id (frame);
struct gdbarch *gdbarch = get_frame_arch (frame);
struct symtab_and_line sal;
struct thread_info *tp = inferior_thread ();
@@ -1653,7 +1654,7 @@
old_chain = make_cleanup_delete_breakpoint (breakpoint);
- set_longjmp_breakpoint (tp, get_frame_id (frame));
+ set_longjmp_breakpoint (tp, frame_id);
make_cleanup (delete_longjmp_breakpoint_cleanup, &thread);
/* We want stop_registers, please... */
diff --git a/gdb/mi/mi-cmd-break.c b/gdb/mi/mi-cmd-break.c
index d73f96a..e04d34d 100644
--- a/gdb/mi/mi-cmd-break.c
+++ b/gdb/mi/mi-cmd-break.c
@@ -168,7 +168,7 @@
temp_p, type_wanted,
ignore_count,
pending ? AUTO_BOOLEAN_TRUE : AUTO_BOOLEAN_FALSE,
- &bkpt_breakpoint_ops, 0, enabled, 0);
+ &bkpt_breakpoint_ops, 0, enabled, 0, 0);
do_cleanups (back_to);
}
diff --git a/gdb/mi/mi-main.c b/gdb/mi/mi-main.c
index b9c945c..b170f01 100644
--- a/gdb/mi/mi-main.c
+++ b/gdb/mi/mi-main.c
@@ -2065,7 +2065,7 @@
This is not a problem -- frontend should always provide --thread if
it wishes to operate on a specific thread. */
if (inf->pid != 0)
- tp = any_thread_of_process (inf->pid);
+ tp = any_live_thread_of_process (inf->pid);
switch_to_thread (tp ? tp->ptid : null_ptid);
set_current_program_space (inf->pspace);
}
diff --git a/gdb/p-typeprint.c b/gdb/p-typeprint.c
index 7bcacdf..dae56d3 100644
--- a/gdb/p-typeprint.c
+++ b/gdb/p-typeprint.c
@@ -183,8 +183,7 @@
physname += len;
for (j = 0; j < i; ++j)
- fputc_filtered (physname[i], stream);
- fputs_filtered (physname, stream);
+ fputc_filtered (physname[j], stream);
physname += i;
if (physname[0] != 0)
diff --git a/gdb/po/gdb.pot b/gdb/po/gdb.pot
index ca62b7c..f726b2f 100644
--- a/gdb/po/gdb.pot
+++ b/gdb/po/gdb.pot
@@ -8,7 +8,7 @@
msgstr ""
"Project-Id-Version: PACKAGE VERSION\n"
"Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2012-01-24 09:23+0000\n"
+"POT-Creation-Date: 2012-04-26 15:22+0000\n"
"PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
"Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
"Language-Team: LANGUAGE <LL@li.org>\n"
@@ -593,11 +593,11 @@
msgid "`%s' Ada exception"
msgstr ""
-#: ada-lang.c:11287 breakpoint.c:9796
+#: ada-lang.c:11287 breakpoint.c:9806
msgid "Temporary catchpoint "
msgstr ""
-#: ada-lang.c:11288 breakpoint.c:9797
+#: ada-lang.c:11288 breakpoint.c:9807
msgid "Catchpoint "
msgstr ""
@@ -622,8 +622,8 @@
msgid "unexpected catchpoint kind (%d)"
msgstr ""
-#: ada-lang.c:11806 breakpoint.c:7635 breakpoint.c:9544 breakpoint.c:9673
-#: breakpoint.c:9718 breakpoint.c:9861 breakpoint.c:13030 skip.c:191
+#: ada-lang.c:11806 breakpoint.c:7643 breakpoint.c:9554 breakpoint.c:9683
+#: breakpoint.c:9728 breakpoint.c:9872 breakpoint.c:13042 skip.c:191
msgid "Junk at end of arguments."
msgstr ""
@@ -2455,7 +2455,7 @@
"breakpoint."
msgstr ""
-#: breakpoint.c:698 breakpoint.c:12114
+#: breakpoint.c:698 breakpoint.c:12125
#, possible-c-format
msgid "No breakpoint number %d."
msgstr ""
@@ -2568,7 +2568,7 @@
#. Did we stop because the user set the stop_on_solib_events
#. variable? (If so, we report this as a generic, "Stopped due
#. to shlib event" message.)
-#: breakpoint.c:3520 breakpoint.c:11123
+#: breakpoint.c:3520 breakpoint.c:11134
msgid "Stopped due to shared library event\n"
msgstr ""
@@ -2662,232 +2662,232 @@
msgid "Catchpoint %d (exec)"
msgstr ""
-#: breakpoint.c:7264 breakpoint.c:12318
+#: breakpoint.c:7265 breakpoint.c:12329
msgid "No hardware breakpoint support in the target."
msgstr ""
-#: breakpoint.c:7266 breakpoint.c:8335 breakpoint.c:12320
+#: breakpoint.c:7267 breakpoint.c:8345 breakpoint.c:12331
msgid "Hardware breakpoints used exceeds limit."
msgstr ""
-#: breakpoint.c:7317 breakpoint.c:7326
+#: breakpoint.c:7321 breakpoint.c:7330
#, possible-c-format
msgid "Probed static tracepoint marker \"%s\"\n"
msgstr ""
-#: breakpoint.c:7331
+#: breakpoint.c:7335
msgid "Couldn't determine the static tracepoint marker to probe"
msgstr ""
-#: breakpoint.c:7350
+#: breakpoint.c:7356
#, possible-c-format
msgid "Garbage %s follows condition"
msgstr ""
-#: breakpoint.c:7502
+#: breakpoint.c:7510
msgid "No default breakpoint address now."
msgstr ""
-#: breakpoint.c:7567
+#: breakpoint.c:7575
#, possible-c-format
msgid "May not have a fast tracepoint at 0x%s%s"
msgstr ""
-#: breakpoint.c:7618
+#: breakpoint.c:7626
msgid "Junk after thread keyword."
msgstr ""
-#: breakpoint.c:7620 breakpoint.c:9098 thread.c:1239
+#: breakpoint.c:7628 breakpoint.c:9108 thread.c:1239
#, possible-c-format
msgid "Unknown thread %d."
msgstr ""
-#: breakpoint.c:7630
+#: breakpoint.c:7638
msgid "Junk after task keyword."
msgstr ""
-#: breakpoint.c:7632
+#: breakpoint.c:7640
#, possible-c-format
msgid "Unknown task %d."
msgstr ""
-#: breakpoint.c:7663
+#: breakpoint.c:7671
#, possible-c-format
msgid "No known static tracepoint marker named %s"
msgstr ""
-#: breakpoint.c:7766
+#: breakpoint.c:7775
#, possible-c-format
msgid "Make %s pending on future shared library load? "
msgstr ""
-#: breakpoint.c:7944
+#: breakpoint.c:7953
msgid ""
"Multiple breakpoints were set.\n"
"Use the \"delete\" command to delete unwanted breakpoints."
msgstr ""
-#: breakpoint.c:7998 linespec.c:2429
+#: breakpoint.c:8008 linespec.c:2429
#, possible-c-format
msgid "No line %d in file \"%s\"."
msgstr ""
-#: breakpoint.c:8072
+#: breakpoint.c:8082
msgid ""
"Specify the type of breakpoint to set.\n"
"Usage: stop in <function | address>\n"
" stop at <line>\n"
msgstr ""
-#: breakpoint.c:8105
+#: breakpoint.c:8115
msgid "Usage: stop in <function | address>\n"
msgstr ""
-#: breakpoint.c:8137
+#: breakpoint.c:8147
msgid "Usage: stop at <line>\n"
msgstr ""
-#: breakpoint.c:8262
+#: breakpoint.c:8272
#, possible-c-format
msgid "Hardware assisted ranged breakpoint %d from %s to %s."
msgstr ""
-#: breakpoint.c:8303 breakpoint.c:8383
+#: breakpoint.c:8313 breakpoint.c:8393
msgid "Could not find location of the end of the range."
msgstr ""
-#: breakpoint.c:8328
+#: breakpoint.c:8338
msgid "This target does not support hardware ranged breakpoints."
msgstr ""
-#: breakpoint.c:8339
+#: breakpoint.c:8349
msgid "No address range specified."
msgstr ""
-#: breakpoint.c:8349
+#: breakpoint.c:8359
msgid "Too few arguments."
msgstr ""
-#: breakpoint.c:8351
+#: breakpoint.c:8361
msgid "Could not find location of the beginning of the range."
msgstr ""
-#: breakpoint.c:8357 breakpoint.c:8388
+#: breakpoint.c:8367 breakpoint.c:8398
msgid "Cannot create a ranged breakpoint with multiple locations."
msgstr ""
-#: breakpoint.c:8396
+#: breakpoint.c:8406
msgid "Invalid address range, end precedes start."
msgstr ""
#. Length overflowed.
-#: breakpoint.c:8401
+#: breakpoint.c:8411
msgid "Address range too large."
msgstr ""
-#: breakpoint.c:8788 breakpoint.c:8911 breakpoint.c:8967 breakpoint.c:8998
+#: breakpoint.c:8798 breakpoint.c:8921 breakpoint.c:8977 breakpoint.c:9008
msgid "Invalid hardware watchpoint type."
msgstr ""
-#: breakpoint.c:8819
+#: breakpoint.c:8829
msgid "Invalid watchpoint type."
msgstr ""
-#: breakpoint.c:8915
+#: breakpoint.c:8925
msgid ""
"\n"
"Check the underlying instruction at PC for the memory\n"
"address and value which triggered this watchpoint.\n"
msgstr ""
-#: breakpoint.c:9086
+#: breakpoint.c:9096
msgid "You can specify only one thread."
msgstr ""
-#: breakpoint.c:9094
+#: breakpoint.c:9104
#, possible-c-format
msgid "Invalid thread ID specification %s."
msgstr ""
-#: breakpoint.c:9108
+#: breakpoint.c:9118
msgid "You can specify only one mask."
msgstr ""
-#: breakpoint.c:9146
+#: breakpoint.c:9156
#, possible-c-format
msgid "Cannot watch constant value `%.*s'."
msgstr ""
-#: breakpoint.c:9167
+#: breakpoint.c:9177
msgid "This target does not support masked watchpoints."
msgstr ""
-#: breakpoint.c:9169
+#: breakpoint.c:9179
msgid "Invalid mask or memory region."
msgstr ""
-#: breakpoint.c:9195
+#: breakpoint.c:9205
msgid "Junk at end of command."
msgstr ""
-#: breakpoint.c:9538
+#: breakpoint.c:9548
msgid "Couldn't get information on specified line."
msgstr ""
-#: breakpoint.c:9690
+#: breakpoint.c:9700
msgid "unsupported or unknown fork kind; cannot catch it"
msgstr ""
-#: breakpoint.c:9799
+#: breakpoint.c:9809
msgid " (throw)"
msgstr ""
-#: breakpoint.c:9800
+#: breakpoint.c:9810
msgid " (catch)"
msgstr ""
-#: breakpoint.c:9865
+#: breakpoint.c:9876
msgid "Unsupported or unknown exception event; cannot catch it"
msgstr ""
-#: breakpoint.c:9870
+#: breakpoint.c:9881
msgid "Unsupported with this platform/compiler combination."
msgstr ""
#. Here we have to issue an error instead of a warning,
#. because GDB cannot do anything useful if there's no
#. syscall number to be caught.
-#: breakpoint.c:9966
+#: breakpoint.c:9977
#, possible-c-format
msgid "Unknown syscall name '%s'."
msgstr ""
-#: breakpoint.c:9990
+#: breakpoint.c:10001
msgid "The feature 'catch syscall' is not supported on this architecture yet."
msgstr ""
-#: breakpoint.c:10021 breakpoint.c:10028
+#: breakpoint.c:10032 breakpoint.c:10039
msgid "Catch requires an event name."
msgstr ""
-#: breakpoint.c:10085
+#: breakpoint.c:10096
msgid "No source file specified."
msgstr ""
-#: breakpoint.c:10175
+#: breakpoint.c:10186
#, possible-c-format
msgid "No breakpoint at %s."
msgstr ""
-#: breakpoint.c:10177
+#: breakpoint.c:10188
msgid "No breakpoint at this line."
msgstr ""
-#: breakpoint.c:10200
+#: breakpoint.c:10211
msgid "Deleted breakpoint "
msgstr ""
-#: breakpoint.c:10202
+#: breakpoint.c:10213
msgid "Deleted breakpoints "
msgstr ""
@@ -2899,195 +2899,195 @@
#. Note that at this point, old_loc->owner is still
#. valid, as delete_breakpoint frees the breakpoint
#. only after calling us.
-#: breakpoint.c:10547
+#: breakpoint.c:10558
#, possible-c-format
msgid "warning: Error removing breakpoint %d\n"
msgstr ""
-#: breakpoint.c:10651
+#: breakpoint.c:10662
msgid "allegedly permanent breakpoint is not actually inserted"
msgstr ""
-#: breakpoint.c:10683
+#: breakpoint.c:10694
msgid "another breakpoint was inserted on top of a permanent breakpoint"
msgstr ""
-#: breakpoint.c:10763
+#: breakpoint.c:10774
#, possible-c-format
msgid " (%s) pending."
msgstr ""
-#: breakpoint.c:11040
+#: breakpoint.c:11051
msgid "Temporary breakpoint"
msgstr ""
-#: breakpoint.c:11042
+#: breakpoint.c:11053
msgid "Breakpoint"
msgstr ""
-#: breakpoint.c:11043 breakpoint.c:11261 breakpoint.c:11265 breakpoint.c:11269
+#: breakpoint.c:11054 breakpoint.c:11272 breakpoint.c:11276 breakpoint.c:11280
#, possible-c-format
msgid " %d"
msgstr ""
-#: breakpoint.c:11045
+#: breakpoint.c:11056
msgid " at gnu-indirect-function resolver"
msgstr ""
-#: breakpoint.c:11048
+#: breakpoint.c:11059
#, possible-c-format
msgid "Hardware assisted breakpoint %d"
msgstr ""
-#: breakpoint.c:11069
+#: breakpoint.c:11080
#, possible-c-format
msgid "unhandled breakpoint type %d"
msgstr ""
#. Not sure how we will get here.
#. GDB should not stop for these breakpoints.
-#: breakpoint.c:11132
+#: breakpoint.c:11143
msgid "Thread Event Breakpoint: gdb should not stop!\n"
msgstr ""
#. By analogy with the thread event, GDB should not stop for these.
-#: breakpoint.c:11137
+#: breakpoint.c:11148
msgid "Overlay Event Breakpoint: gdb should not stop!\n"
msgstr ""
#. These should never be enabled.
-#: breakpoint.c:11142
+#: breakpoint.c:11153
msgid "Longjmp Master Breakpoint: gdb should not stop!\n"
msgstr ""
#. These should never be enabled.
-#: breakpoint.c:11147
+#: breakpoint.c:11158
msgid "std::terminate Master Breakpoint: gdb should not stop!\n"
msgstr ""
#. These should never be enabled.
-#: breakpoint.c:11153
+#: breakpoint.c:11164
msgid "Exception Master Breakpoint: gdb should not stop!\n"
msgstr ""
-#: breakpoint.c:11260
+#: breakpoint.c:11271
msgid "Tracepoint"
msgstr ""
-#: breakpoint.c:11264
+#: breakpoint.c:11275
msgid "Fast tracepoint"
msgstr ""
-#: breakpoint.c:11268
+#: breakpoint.c:11279
msgid "Static tracepoint"
msgstr ""
-#: breakpoint.c:11273 breakpoint.c:11292
+#: breakpoint.c:11284 breakpoint.c:11303
#, possible-c-format
msgid "unhandled tracepoint type %d"
msgstr ""
-#: breakpoint.c:11486
+#: breakpoint.c:11497
msgid "Delete all breakpoints? "
msgstr ""
-#: breakpoint.c:11593
+#: breakpoint.c:11604
#, possible-c-format
msgid "static tracepoint %d changed probed marker from %s to %s"
msgstr ""
-#: breakpoint.c:11628
+#: breakpoint.c:11639
#, possible-c-format
msgid "marker for static tracepoint %d (%s) not found at previous line number"
msgstr ""
-#: breakpoint.c:11726
+#: breakpoint.c:11737
#, possible-c-format
msgid "Could not reset ranged breakpoint %d: multiple locations found\n"
msgstr ""
-#: breakpoint.c:11766
+#: breakpoint.c:11777
#, possible-c-format
msgid "failed to reevaluate condition for breakpoint %d: %s"
msgstr ""
-#: breakpoint.c:11857
+#: breakpoint.c:11868
#, possible-c-format
msgid "marker %s not found"
msgstr ""
-#: breakpoint.c:12089
+#: breakpoint.c:12100
#, possible-c-format
msgid "Ignore count ignored for tracepoint %d."
msgstr ""
-#: breakpoint.c:12098
+#: breakpoint.c:12109
#, possible-c-format
msgid "Will stop next time breakpoint %d is reached."
msgstr ""
-#: breakpoint.c:12102
+#: breakpoint.c:12113
#, possible-c-format
msgid "Will ignore next crossing of breakpoint %d."
msgstr ""
-#: breakpoint.c:12105
+#: breakpoint.c:12116
#, possible-c-format
msgid "Will ignore next %d crossings of breakpoint %d."
msgstr ""
-#: breakpoint.c:12126
+#: breakpoint.c:12137
msgid "a breakpoint number"
msgstr ""
-#: breakpoint.c:12130
+#: breakpoint.c:12141
#, possible-c-format
msgid "bad breakpoint number: '%s'"
msgstr ""
-#: breakpoint.c:12132
+#: breakpoint.c:12143
msgid "Second argument (specified ignore-count) is missing."
msgstr ""
-#: breakpoint.c:12155
+#: breakpoint.c:12166
msgid "one or more breakpoint numbers"
msgstr ""
-#: breakpoint.c:12168
+#: breakpoint.c:12179
#, possible-c-format
msgid "bad breakpoint number at or near '%s'"
msgstr ""
-#: breakpoint.c:12180
+#: breakpoint.c:12191
#, possible-c-format
msgid "No breakpoint number %d.\n"
msgstr ""
-#: breakpoint.c:12200 breakpoint.c:12209
+#: breakpoint.c:12211 breakpoint.c:12220
#, possible-c-format
msgid "Bad breakpoint number '%s'"
msgstr ""
-#: breakpoint.c:12214 breakpoint.c:12221
+#: breakpoint.c:12225 breakpoint.c:12232
#, possible-c-format
msgid "Bad breakpoint location number '%s'"
msgstr ""
-#: breakpoint.c:12340
+#: breakpoint.c:12351
#, possible-c-format
msgid "Cannot enable watchpoint %d: "
msgstr ""
-#: breakpoint.c:12507 symtab.c:4681
+#: breakpoint.c:12518 symtab.c:4681
msgid "Empty line specification."
msgstr ""
-#: breakpoint.c:12515 symtab.c:4691
+#: breakpoint.c:12526 symtab.c:4691
#, possible-c-format
msgid "Junk at end of line specification: %s"
msgstr ""
-#: breakpoint.c:12597
+#: breakpoint.c:12608
#, possible-c-format
msgid "Could not insert single-step breakpoint at %s"
msgstr ""
@@ -3096,76 +3096,76 @@
#. address. Since there is no way to confirm that the address
#. means the same thing as when the trace was started, warn the
#. user.
-#: breakpoint.c:12850
+#: breakpoint.c:12861
#, possible-c-format
msgid "Uploaded tracepoint %d has no source location, using raw address"
msgstr ""
-#: breakpoint.c:12859
+#: breakpoint.c:12870
#, possible-c-format
msgid "Uploaded tracepoint %d condition has no source form, ignoring it"
msgstr ""
-#: breakpoint.c:12906
+#: breakpoint.c:12918
#, possible-c-format
msgid "Uploaded tracepoint %d actions have no source form, ignoring them"
msgstr ""
-#: breakpoint.c:12980
+#: breakpoint.c:12992
msgid "Delete all tracepoints? "
msgstr ""
-#: breakpoint.c:12999
+#: breakpoint.c:13011
#, possible-c-format
msgid "Setting tracepoint %d's passcount to %d\n"
msgstr ""
-#: breakpoint.c:13016
+#: breakpoint.c:13028
msgid "passcount command requires an argument (count + optional TP num)"
msgstr ""
-#: breakpoint.c:13114
+#: breakpoint.c:13126
msgid "tracepoint number"
msgstr ""
-#: breakpoint.c:13122
+#: breakpoint.c:13134
#, possible-c-format
msgid "bad tracepoint number at or near '%s'\n"
msgstr ""
-#: breakpoint.c:13125
+#: breakpoint.c:13137
msgid "Tracepoint argument missing and no previous tracepoint\n"
msgstr ""
-#: breakpoint.c:13169
+#: breakpoint.c:13181
msgid "Argument required (file name in which to save)"
msgstr ""
-#: breakpoint.c:13195
+#: breakpoint.c:13207
msgid "Nothing to save."
msgstr ""
-#: breakpoint.c:13203
+#: breakpoint.c:13215
#, possible-c-format
msgid "Unable to open file '%s' for saving (%s)"
msgstr ""
-#: breakpoint.c:13273
+#: breakpoint.c:13285
#, possible-c-format
msgid "Saved to file '%s'.\n"
msgstr ""
-#: breakpoint.c:13371
+#: breakpoint.c:13383
msgid "\"save\" must be followed by the name of a save subcommand.\n"
msgstr ""
-#: breakpoint.c:13598
+#: breakpoint.c:13610
msgid ""
"Set ignore-count of breakpoint number N to COUNT.\n"
"Usage is `ignore N COUNT'."
msgstr ""
-#: breakpoint.c:13604
+#: breakpoint.c:13616
msgid ""
"Set commands to be executed when a breakpoint is hit.\n"
"Give breakpoint number as argument after \"commands\".\n"
@@ -3176,14 +3176,14 @@
"then no output is printed when it is hit, except what the commands print."
msgstr ""
-#: breakpoint.c:13613
+#: breakpoint.c:13625
msgid ""
"Specify breakpoint number N to break only if COND is true.\n"
"Usage is `condition N COND', where N is an integer and COND is an\n"
"expression to be evaluated whenever breakpoint N is reached."
msgstr ""
-#: breakpoint.c:13618
+#: breakpoint.c:13630
msgid ""
"Set a temporary breakpoint.\n"
"Like \"break\" except the breakpoint is only temporary,\n"
@@ -3192,7 +3192,7 @@
"\n"
msgstr ""
-#: breakpoint.c:13627
+#: breakpoint.c:13639
msgid ""
"Set a hardware assisted breakpoint.\n"
"Like \"break\" except the breakpoint requires hardware support,\n"
@@ -3200,7 +3200,7 @@
"\n"
msgstr ""
-#: breakpoint.c:13635
+#: breakpoint.c:13647
msgid ""
"Set a temporary hardware assisted breakpoint.\n"
"Like \"hbreak\" except the breakpoint is only temporary,\n"
@@ -3208,7 +3208,7 @@
"\n"
msgstr ""
-#: breakpoint.c:13643 breakpoint.c:13651
+#: breakpoint.c:13655 breakpoint.c:13663
msgid ""
"Enable some breakpoints.\n"
"Give breakpoint numbers (separated by spaces) as arguments.\n"
@@ -3217,7 +3217,7 @@
"With a subcommand you can enable temporarily."
msgstr ""
-#: breakpoint.c:13660
+#: breakpoint.c:13672
msgid ""
"Enable some breakpoints.\n"
"Give breakpoint numbers (separated by spaces) as arguments.\n"
@@ -3225,19 +3225,19 @@
"May be abbreviated to simply \"enable\".\n"
msgstr ""
-#: breakpoint.c:13667 breakpoint.c:13682
+#: breakpoint.c:13679 breakpoint.c:13694
msgid ""
"Enable breakpoints for one hit. Give breakpoint numbers.\n"
"If a breakpoint is hit while enabled in this fashion, it becomes disabled."
msgstr ""
-#: breakpoint.c:13672 breakpoint.c:13677
+#: breakpoint.c:13684 breakpoint.c:13689
msgid ""
"Enable breakpoints and delete when hit. Give breakpoint numbers.\n"
"If a breakpoint is hit while enabled in this fashion, it is deleted."
msgstr ""
-#: breakpoint.c:13687 breakpoint.c:13696
+#: breakpoint.c:13699 breakpoint.c:13708
msgid ""
"Disable some breakpoints.\n"
"Arguments are breakpoint numbers with spaces in between.\n"
@@ -3245,7 +3245,7 @@
"A disabled breakpoint is not forgotten, but has no effect until re-enabled."
msgstr ""
-#: breakpoint.c:13702
+#: breakpoint.c:13714
msgid ""
"Disable some breakpoints.\n"
"Arguments are breakpoint numbers with spaces in between.\n"
@@ -3254,7 +3254,7 @@
"This command may be abbreviated \"disable\"."
msgstr ""
-#: breakpoint.c:13710
+#: breakpoint.c:13722
msgid ""
"Delete some breakpoints or auto-display expressions.\n"
"Arguments are breakpoint numbers with spaces in between.\n"
@@ -3264,14 +3264,14 @@
"The \"unset\" command is also an alias for \"delete\"."
msgstr ""
-#: breakpoint.c:13721
+#: breakpoint.c:13733
msgid ""
"Delete some breakpoints.\n"
"Arguments are breakpoint numbers with spaces in between.\n"
"To delete all breakpoints, give no argument.\n"
msgstr ""
-#: breakpoint.c:13726
+#: breakpoint.c:13738
msgid ""
"Delete some breakpoints or auto-display expressions.\n"
"Arguments are breakpoint numbers with spaces in between.\n"
@@ -3279,7 +3279,7 @@
"This command may be abbreviated \"delete\"."
msgstr ""
-#: breakpoint.c:13733
+#: breakpoint.c:13745
msgid ""
"Clear breakpoint at specified line or function.\n"
"Argument may be line number, function name, or \"*\" and an address.\n"
@@ -3294,23 +3294,23 @@
"See also the \"delete\" command which clears breakpoints by number."
msgstr ""
-#: breakpoint.c:13746
+#: breakpoint.c:13758
msgid "Set breakpoint at specified line or function.\n"
msgstr ""
-#: breakpoint.c:13761
+#: breakpoint.c:13773
msgid "Break in function/address or break at a line in the current file."
msgstr ""
-#: breakpoint.c:13765
+#: breakpoint.c:13777
msgid "Break in function or address."
msgstr ""
-#: breakpoint.c:13767
+#: breakpoint.c:13779
msgid "Break at a line in the current file."
msgstr ""
-#: breakpoint.c:13768 breakpoint.c:13804
+#: breakpoint.c:13780 breakpoint.c:13816
msgid ""
"Status of user-settable breakpoints, or breakpoint number NUMBER.\n"
"The \"Type\" column indicates one of:\n"
@@ -3332,7 +3332,7 @@
"breakpoint set."
msgstr ""
-#: breakpoint.c:13785
+#: breakpoint.c:13797
msgid ""
"Status of specified breakpoints (all user-settable breakpoints if no "
"argument).\n"
@@ -3355,7 +3355,7 @@
"breakpoint set."
msgstr ""
-#: breakpoint.c:13820
+#: breakpoint.c:13832
msgid ""
"Status of all breakpoints, or breakpoint number NUMBER.\n"
"The \"Type\" column indicates one of:\n"
@@ -3381,42 +3381,42 @@
"breakpoint set."
msgstr ""
-#: breakpoint.c:13841
+#: breakpoint.c:13853
msgid "Set catchpoints to catch events."
msgstr ""
#. allow-unknown
-#: breakpoint.c:13846
+#: breakpoint.c:13858
msgid "Set temporary catchpoints to catch events."
msgstr ""
#. allow-unknown
#. Add catch and tcatch sub-commands.
-#: breakpoint.c:13852
+#: breakpoint.c:13864
msgid ""
"Catch an exception, when caught.\n"
"With an argument, catch only exceptions with the given name."
msgstr ""
-#: breakpoint.c:13859
+#: breakpoint.c:13871
msgid ""
"Catch an exception, when thrown.\n"
"With an argument, catch only exceptions with the given name."
msgstr ""
-#: breakpoint.c:13866
+#: breakpoint.c:13878
msgid "Catch calls to fork."
msgstr ""
-#: breakpoint.c:13871
+#: breakpoint.c:13883
msgid "Catch calls to vfork."
msgstr ""
-#: breakpoint.c:13876
+#: breakpoint.c:13888
msgid "Catch calls to exec."
msgstr ""
-#: breakpoint.c:13881
+#: breakpoint.c:13893
msgid ""
"Catch system calls by their names and/or numbers.\n"
"Arguments say which system calls to catch. If no arguments\n"
@@ -3425,7 +3425,7 @@
"(if your system supports that), or system call numbers."
msgstr ""
-#: breakpoint.c:13892
+#: breakpoint.c:13904
msgid ""
"Set a watchpoint for an expression.\n"
"Usage: watch [-l|-location] EXPRESSION\n"
@@ -3435,7 +3435,7 @@
"the memory to which it refers."
msgstr ""
-#: breakpoint.c:13901
+#: breakpoint.c:13913
msgid ""
"Set a read watchpoint for an expression.\n"
"Usage: rwatch [-l|-location] EXPRESSION\n"
@@ -3445,7 +3445,7 @@
"the memory to which it refers."
msgstr ""
-#: breakpoint.c:13910
+#: breakpoint.c:13922
msgid ""
"Set a watchpoint for an expression.\n"
"Usage: awatch [-l|-location] EXPRESSION\n"
@@ -3455,19 +3455,19 @@
"the memory to which it refers."
msgstr ""
-#: breakpoint.c:13919
+#: breakpoint.c:13931
msgid "Status of specified watchpoints (all watchpoints if no argument)."
msgstr ""
-#: breakpoint.c:13925
+#: breakpoint.c:13937
msgid "Set debugger's willingness to use watchpoint hardware."
msgstr ""
-#: breakpoint.c:13926
+#: breakpoint.c:13938
msgid "Show debugger's willingness to use watchpoint hardware."
msgstr ""
-#: breakpoint.c:13927
+#: breakpoint.c:13939
msgid ""
"If zero, gdb will not use hardware for new watchpoints, even if\n"
"such is available. (However, any hardware watchpoints that were\n"
@@ -3476,25 +3476,25 @@
msgstr ""
#. Tracepoint manipulation commands.
-#: breakpoint.c:13940
+#: breakpoint.c:13952
msgid ""
"Set a tracepoint at specified line or function.\n"
"\n"
msgstr ""
-#: breakpoint.c:13943 breakpoint.c:13955
+#: breakpoint.c:13955 breakpoint.c:13967
msgid ""
"\n"
"Do \"help tracepoints\" for info on other tracepoint commands."
msgstr ""
-#: breakpoint.c:13952
+#: breakpoint.c:13964
msgid ""
"Set a fast tracepoint at specified line or function.\n"
"\n"
msgstr ""
-#: breakpoint.c:13959
+#: breakpoint.c:13971
msgid ""
"Set a static tracepoint at specified line, function or marker.\n"
"\n"
@@ -3522,35 +3522,35 @@
"Do \"help tracepoints\" for info on other tracepoint commands."
msgstr ""
-#: breakpoint.c:13985
+#: breakpoint.c:13997
msgid ""
"Status of specified tracepoints (all tracepoints if no argument).\n"
"Convenience variable \"$tpnum\" contains the number of the\n"
"last tracepoint set."
msgstr ""
-#: breakpoint.c:13992
+#: breakpoint.c:14004
msgid ""
"Delete specified tracepoints.\n"
"Arguments are tracepoint numbers, separated by spaces.\n"
"No argument means delete all tracepoints."
msgstr ""
-#: breakpoint.c:13998
+#: breakpoint.c:14010
msgid ""
"Disable specified tracepoints.\n"
"Arguments are tracepoint numbers, separated by spaces.\n"
"No argument means disable all tracepoints."
msgstr ""
-#: breakpoint.c:14005
+#: breakpoint.c:14017
msgid ""
"Enable specified tracepoints.\n"
"Arguments are tracepoint numbers, separated by spaces.\n"
"No argument means enable all tracepoints."
msgstr ""
-#: breakpoint.c:14012
+#: breakpoint.c:14024
msgid ""
"Set the passcount for a tracepoint.\n"
"The trace will end when the tracepoint has been passed 'count' times.\n"
@@ -3558,12 +3558,12 @@
"if TPNUM is omitted, passcount refers to the last tracepoint defined."
msgstr ""
-#: breakpoint.c:14019
+#: breakpoint.c:14031
msgid "Save breakpoint definitions as a script."
msgstr ""
#. allow-unknown
-#: breakpoint.c:14023
+#: breakpoint.c:14035
msgid ""
"Save current breakpoint definitions as a script.\n"
"This includes all types of breakpoints (breakpoints, watchpoints,\n"
@@ -3571,29 +3571,29 @@
"session to restore them."
msgstr ""
-#: breakpoint.c:14031
+#: breakpoint.c:14043
msgid ""
"Save current tracepoint definitions as a script.\n"
"Use the 'source' command in another debug session to restore them."
msgstr ""
#. allow-unknown
-#: breakpoint.c:14040 breakpoint.c:14046
+#: breakpoint.c:14052 breakpoint.c:14058
msgid ""
"Breakpoint specific settings\n"
"Configure various breakpoint-specific variables such as\n"
"pending breakpoint behavior"
msgstr ""
-#: breakpoint.c:14054
+#: breakpoint.c:14066
msgid "Set debugger's behavior regarding pending breakpoints."
msgstr ""
-#: breakpoint.c:14055
+#: breakpoint.c:14067
msgid "Show debugger's behavior regarding pending breakpoints."
msgstr ""
-#: breakpoint.c:14056
+#: breakpoint.c:14068
msgid ""
"If on, an unrecognized breakpoint location will cause gdb to create a\n"
"pending breakpoint. If off, an unrecognized breakpoint location results in\n"
@@ -3601,15 +3601,15 @@
"user-query to see if a pending breakpoint should be created."
msgstr ""
-#: breakpoint.c:14069
+#: breakpoint.c:14081
msgid "Set automatic usage of hardware breakpoints."
msgstr ""
-#: breakpoint.c:14070
+#: breakpoint.c:14082
msgid "Show automatic usage of hardware breakpoints."
msgstr ""
-#: breakpoint.c:14071
+#: breakpoint.c:14083
msgid ""
"If set, the debugger will automatically use hardware breakpoints for\n"
"breakpoints set with \"break\" but falling in read-only memory. If not "
@@ -3617,15 +3617,15 @@
"a warning will be emitted for such breakpoints."
msgstr ""
-#: breakpoint.c:14081
+#: breakpoint.c:14093
msgid "Set mode for inserting breakpoints."
msgstr ""
-#: breakpoint.c:14082
+#: breakpoint.c:14094
msgid "Show mode for inserting breakpoints."
msgstr ""
-#: breakpoint.c:14083
+#: breakpoint.c:14095
msgid ""
"When this mode is off, breakpoints are inserted in inferior when it is\n"
"resumed, and removed when execution stops. When this mode is on,\n"
@@ -3637,7 +3637,7 @@
"inferior in all-stop mode, gdb behaves as if always-inserted mode is off."
msgstr ""
-#: breakpoint.c:14097
+#: breakpoint.c:14109
msgid ""
"Set a breakpoint for an address range.\n"
"break-range START-LOCATION, END-LOCATION\n"
@@ -3996,7 +3996,7 @@
msgstr ""
#: cli/cli-cmds.c:336 cli/cli-script.c:1501 infcmd.c:1140 infcmd.c:1154
-#: infcmd.c:2288 symfile.c:1103 symfile.c:1268 symfile.c:2360
+#: infcmd.c:2289 symfile.c:1103 symfile.c:1268 symfile.c:2360
#: tracepoint.c:2165 tracepoint.c:2171
msgid "Not confirmed."
msgstr ""
@@ -4986,7 +4986,7 @@
#: infcall.c:671 infcmd.c:1460 infrun.c:3306 language.c:797 language.c:823
#: mi/mi-out.c:348 mi/mi-out.c:367 mips-tdep.c:254 mips-tdep.c:311
#: mips-tdep.c:1411 mips-tdep.c:4086 mips-tdep.c:5073 mn10300-tdep.c:126
-#: reggroups.c:219 remote.c:6492 utils.c:987 utils.c:1006
+#: reggroups.c:219 remote.c:6508 utils.c:987 utils.c:1006
msgid "bad switch"
msgstr ""
@@ -8796,7 +8796,7 @@
msgid "No selected thread."
msgstr ""
-#: frame.c:1299 infcmd.c:1796
+#: frame.c:1299 infcmd.c:1797
msgid "Invalid selected thread."
msgstr ""
@@ -10301,7 +10301,7 @@
"Cannot convert non-floating-point type to floating-point register value."
msgstr ""
-#: i387-tdep.c:1044 i387-tdep.c:1089
+#: i387-tdep.c:1065 i387-tdep.c:1110
msgid "invalid i387 regclass"
msgstr ""
@@ -10550,7 +10550,7 @@
msgid "Use the \"run\" command to start a Unix child process."
msgstr ""
-#: infcmd.c:128 infcmd.c:2286 infcmd.c:2674 linux-fork.c:658 remote-sim.c:888
+#: infcmd.c:128 infcmd.c:2287 infcmd.c:2675 linux-fork.c:658 remote-sim.c:888
msgid "The program is not being run."
msgstr ""
@@ -10584,7 +10584,7 @@
msgstr ""
#: infcmd.c:557 infcmd.c:730 infcmd.c:873 infcmd.c:1113 infcmd.c:1217
-#: infcmd.c:1366 infcmd.c:1402 infcmd.c:1698 infcmd.c:2518
+#: infcmd.c:1366 infcmd.c:1402 infcmd.c:1699 infcmd.c:2519
msgid "Asynchronous execution not supported on this target."
msgstr ""
@@ -10681,152 +10681,152 @@
msgid "Finish: couldn't find function."
msgstr ""
-#: infcmd.c:1709
+#: infcmd.c:1710
msgid "The \"finish\" command does not take any arguments."
msgstr ""
#. Finishing from an inline frame is completely different. We don't
#. try to show the "return value" - no way to locate it. So we do
#. not need a completion.
-#: infcmd.c:1711 infcmd.c:1720
+#: infcmd.c:1712 infcmd.c:1721
msgid "No selected frame."
msgstr ""
-#: infcmd.c:1713
+#: infcmd.c:1714
msgid "\"finish\" not meaningful in the outermost frame."
msgstr ""
-#: infcmd.c:1741 infcmd.c:1760
+#: infcmd.c:1742 infcmd.c:1761
msgid "Run till exit from "
msgstr ""
-#: infcmd.c:1758
+#: infcmd.c:1759
msgid "Run back to call of "
msgstr ""
-#: infcmd.c:1782
+#: infcmd.c:1783
msgid "The program being debugged is not being run.\n"
msgstr ""
-#: infcmd.c:1798 infrun.c:6500
+#: infcmd.c:1799 infrun.c:6500
msgid "Selected thread is running."
msgstr ""
-#: infcmd.c:1805
+#: infcmd.c:1806
#, possible-c-format
msgid "Program stopped at %s.\n"
msgstr ""
-#: infcmd.c:1808
+#: infcmd.c:1809
msgid "It stopped after being stepped.\n"
msgstr ""
-#: infcmd.c:1817
+#: infcmd.c:1818
msgid "It stopped at a breakpoint that has since been deleted.\n"
msgstr ""
-#: infcmd.c:1821
+#: infcmd.c:1822
#, possible-c-format
msgid "It stopped at breakpoint %d.\n"
msgstr ""
-#: infcmd.c:1827
+#: infcmd.c:1828
#, possible-c-format
msgid "It stopped with signal %s, %s.\n"
msgstr ""
-#: infcmd.c:1834
+#: infcmd.c:1835
msgid "Type \"info stack\" or \"info registers\" for more information.\n"
msgstr ""
-#: infcmd.c:1879
+#: infcmd.c:1880
msgid "environment variable and value"
msgstr ""
-#: infcmd.c:1903
+#: infcmd.c:1904
msgid "environment variable to set"
msgstr ""
-#: infcmd.c:1925
+#: infcmd.c:1926
#, possible-c-format
msgid "Setting environment variable \"%s\" to null value.\n"
msgstr ""
#. If there is no argument, delete all environment variables.
#. Ask for confirmation if reading from the terminal.
-#: infcmd.c:1942
+#: infcmd.c:1943
msgid "Delete all environment variables? "
msgstr ""
-#: infcmd.c:2120 infcmd.c:2271 infcmd.c:2795
+#: infcmd.c:2121 infcmd.c:2272 infcmd.c:2796
msgid "The program has no registers now."
msgstr ""
-#: infcmd.c:2148
+#: infcmd.c:2149
msgid "Missing register name"
msgstr ""
#. Nothing matched.
-#: infcmd.c:2222
+#: infcmd.c:2223
#, possible-c-format
msgid "Invalid register `%.*s'"
msgstr ""
-#: infcmd.c:2287
+#: infcmd.c:2288
msgid "Kill the program being debugged? "
msgstr ""
-#: infcmd.c:2301
+#: infcmd.c:2302
#, possible-c-format
msgid "In %s,\n"
msgstr ""
-#: infcmd.c:2498 target.c:2522
+#: infcmd.c:2499 target.c:2522
msgid "A program is being debugged already. Kill it? "
msgstr ""
-#: infcmd.c:2501
+#: infcmd.c:2502
msgid "Not killed."
msgstr ""
-#: infcmd.c:2509
+#: infcmd.c:2510
msgid "Cannot attach to this target in non-stop mode"
msgstr ""
-#: infcmd.c:2755
+#: infcmd.c:2756
msgid "-a is meaningless in all-stop mode."
msgstr ""
-#: infcmd.c:2803
+#: infcmd.c:2804
msgid "\"unset\" must be followed by the name of an unset subcommand.\n"
msgstr ""
-#: infcmd.c:2815
+#: infcmd.c:2816
msgid "Set terminal for future runs of program being debugged."
msgstr ""
-#: infcmd.c:2816
+#: infcmd.c:2817
msgid "Show terminal for future runs of program being debugged."
msgstr ""
-#: infcmd.c:2817
+#: infcmd.c:2818
msgid "Usage: set inferior-tty /dev/pts/1"
msgstr ""
-#: infcmd.c:2825
+#: infcmd.c:2826
msgid "Set argument list to give program being debugged when it is started."
msgstr ""
-#: infcmd.c:2826
+#: infcmd.c:2827
msgid "Show argument list to give program being debugged when it is started."
msgstr ""
-#: infcmd.c:2827
+#: infcmd.c:2828
msgid ""
"Follow this command with any number of args, to be passed to the program."
msgstr ""
-#: infcmd.c:2833
+#: infcmd.c:2834
msgid ""
"The environment to give the program, or one variable's value.\n"
"With an argument VAR, prints the value of environment variable VAR to\n"
@@ -10834,17 +10834,17 @@
"environment to be given to the program."
msgstr ""
-#: infcmd.c:2841
+#: infcmd.c:2842
msgid "Complement to certain \"set\" commands."
msgstr ""
-#: infcmd.c:2844
+#: infcmd.c:2845
msgid ""
"Cancel environment variable VAR for the program.\n"
"This does not affect the program until the next \"run\" command."
msgstr ""
-#: infcmd.c:2850
+#: infcmd.c:2851
msgid ""
"Set environment variable value to give the program.\n"
"Arguments are VAR VALUE where VAR is variable name and VALUE is value.\n"
@@ -10852,7 +10852,7 @@
"This does not affect the program until the next \"run\" command."
msgstr ""
-#: infcmd.c:2858
+#: infcmd.c:2859
msgid ""
"Add directory DIR(s) to beginning of search path for object files.\n"
"$cwd in the path means the current working directory.\n"
@@ -10861,7 +10861,7 @@
"fully linked executable files and separately compiled object files as needed."
msgstr ""
-#: infcmd.c:2867
+#: infcmd.c:2868
msgid ""
"Current search path for finding object files.\n"
"$cwd in the path means the current working directory.\n"
@@ -10870,11 +10870,11 @@
"fully linked executable files and separately compiled object files as needed."
msgstr ""
-#: infcmd.c:2878
+#: infcmd.c:2879
msgid "Kill execution of program being debugged."
msgstr ""
-#: infcmd.c:2881
+#: infcmd.c:2882
msgid ""
"Attach to a process or file outside of GDB.\n"
"This command attaches to another target, of the same type as your last\n"
@@ -10889,45 +10889,45 @@
"to specify the program, and to load its symbol table."
msgstr ""
-#: infcmd.c:2894
+#: infcmd.c:2895
msgid ""
"Detach a process or file previously attached.\n"
"If a process, it is no longer traced, and it continues its execution. If\n"
"you were debugging a file, the file is closed and gdb no longer accesses it."
msgstr ""
-#: infcmd.c:2900
+#: infcmd.c:2901
msgid ""
"Disconnect from a target.\n"
"The target will wait for another debugger to connect. Not available for\n"
"all targets."
msgstr ""
-#: infcmd.c:2905
+#: infcmd.c:2906
msgid ""
"Continue program giving it signal specified by the argument.\n"
"An argument of \"0\" means continue program without giving it a signal."
msgstr ""
-#: infcmd.c:2909
+#: infcmd.c:2910
msgid ""
"Step one instruction exactly.\n"
"Argument N means do this N times (or till program stops for another reason)."
msgstr ""
-#: infcmd.c:2915
+#: infcmd.c:2916
msgid ""
"Step one instruction, but proceed through subroutine calls.\n"
"Argument N means do this N times (or till program stops for another reason)."
msgstr ""
-#: infcmd.c:2921
+#: infcmd.c:2922
msgid ""
"Execute until selected stack frame returns.\n"
"Upon return, the value returned is printed and put in the value history."
msgstr ""
-#: infcmd.c:2926
+#: infcmd.c:2927
msgid ""
"Step program, proceeding through subroutine calls.\n"
"Like the \"step\" command as long as subroutine calls do not happen;\n"
@@ -10935,34 +10935,34 @@
"Argument N means do this N times (or till program stops for another reason)."
msgstr ""
-#: infcmd.c:2936
+#: infcmd.c:2937
msgid ""
"Step program until it reaches a different source line.\n"
"Argument N means do this N times (or till program stops for another reason)."
msgstr ""
-#: infcmd.c:2942
+#: infcmd.c:2943
msgid ""
"Execute until the program reaches a source line greater than the current\n"
"or a specified location (same args as break command) within the current "
"frame."
msgstr ""
-#: infcmd.c:2949
+#: infcmd.c:2950
msgid ""
"Continue the program up to the given location (same form as args for break "
"command).\n"
"Execution will also stop upon exit from the current stack frame."
msgstr ""
-#: infcmd.c:2955
+#: infcmd.c:2956
msgid ""
"Continue program being debugged at specified line or address.\n"
"Give as argument either LINENUM or *ADDR, where ADDR is an expression\n"
"for an address to start at."
msgstr ""
-#: infcmd.c:2963
+#: infcmd.c:2964
msgid ""
"Usage: go <location>\n"
"Continue program being debugged, stopping at specified line or \n"
@@ -10972,7 +10972,7 @@
"This command is a combination of tbreak and jump."
msgstr ""
-#: infcmd.c:2976
+#: infcmd.c:2977
msgid ""
"Continue program being debugged, after signal or breakpoint.\n"
"If proceeding from breakpoint, a number N may be used as an argument,\n"
@@ -10985,7 +10985,7 @@
"Specifying -a and an ignore count simultaneously is an error."
msgstr ""
-#: infcmd.c:2989
+#: infcmd.c:2990
msgid ""
"Start debugged program. You may specify arguments to give it.\n"
"Args may include \"*\", or \"[...]\"; they are expanded using \"sh\".\n"
@@ -10997,18 +10997,18 @@
"use \"set args\" without arguments."
msgstr ""
-#: infcmd.c:3002
+#: infcmd.c:3003
msgid "Start debugged program with no arguments."
msgstr ""
-#: infcmd.c:3004
+#: infcmd.c:3005
msgid ""
"Run the debugged program until the beginning of the main procedure.\n"
"You may specify arguments to give to your program, just as with the\n"
"\"run\" command."
msgstr ""
-#: infcmd.c:3011
+#: infcmd.c:3012
msgid ""
"Interrupt the execution of the debugged program.\n"
"If non-stop mode is enabled, interrupt only the current thread,\n"
@@ -11016,27 +11016,27 @@
"interrupt all running threads in non-stop mode, use the -a option."
msgstr ""
-#: infcmd.c:3016 infcmd.c:3022
+#: infcmd.c:3017 infcmd.c:3023
msgid ""
"List of integer registers and their contents, for selected stack frame.\n"
"Register name as argument means describe only that register."
msgstr ""
-#: infcmd.c:3025
+#: infcmd.c:3026
msgid ""
"List of all registers and their contents, for selected stack frame.\n"
"Register name as argument means describe only that register."
msgstr ""
-#: infcmd.c:3030
+#: infcmd.c:3031
msgid "Execution status of the program."
msgstr ""
-#: infcmd.c:3033
+#: infcmd.c:3034
msgid "Print the status of the floating point unit\n"
msgstr ""
-#: infcmd.c:3036
+#: infcmd.c:3037
msgid "Print the status of the vector unit\n"
msgstr ""
@@ -15464,7 +15464,7 @@
msgid "monitor_supply_register (%d): bad value from monitor: %s."
msgstr ""
-#: monitor.c:1033 nto-procfs.c:693 remote.c:4850 remote-mips.c:2274
+#: monitor.c:1033 nto-procfs.c:693 remote.c:4866 remote-mips.c:2274
msgid ""
"Interrupted while waiting for the program.\n"
"Give up (and stop debugging it)? "
@@ -16794,11 +16794,11 @@
msgid "print-psymbols takes an output file name and optional symbol file name"
msgstr ""
-#: p-typeprint.c:300
+#: p-typeprint.c:299
msgid "type not handled in pascal_type_print_varspec_prefix()"
msgstr ""
-#: p-typeprint.c:419
+#: p-typeprint.c:418
msgid "type not handled in pascal_type_print_varspec_suffix()"
msgstr ""
@@ -17945,125 +17945,125 @@
#. malformed packet error
#. general case:
-#: remote.c:425
+#: remote.c:429
msgid "remote.c: error in outgoing packet."
msgstr ""
-#: remote.c:427
+#: remote.c:431
#, possible-c-format
msgid "remote.c: error in outgoing packet at field #%ld."
msgstr ""
-#: remote.c:430
+#: remote.c:434
#, possible-c-format
msgid "trace API error 0x%s."
msgstr ""
-#: remote.c:432
+#: remote.c:436
#, possible-c-format
msgid "Target returns error code '%s'."
msgstr ""
-#: remote.c:461
+#: remote.c:465
#, possible-c-format
msgid "invalid qRelocInsn packet: %s"
msgstr ""
-#: remote.c:495
+#: remote.c:499
msgid "warning: relocating instruction: "
msgstr ""
-#: remote.c:761
+#: remote.c:765
msgid ""
"Send the ASCII ETX character (Ctrl-c) to the remote target to interrupt the "
"execution of the program.\n"
msgstr ""
-#: remote.c:766
+#: remote.c:770
msgid ""
"send a break signal to the remote target to interrupt the execution of the "
"program.\n"
msgstr ""
-#: remote.c:770
+#: remote.c:774
msgid ""
"Send a break signal and 'g' a.k.a. Magic SysRq g to the remote target to "
"interrupt the execution of Linux kernel.\n"
msgstr ""
-#: remote.c:775 remote.c:3148
+#: remote.c:779 remote.c:3152
#, possible-c-format
msgid "Invalid value for interrupt_sequence_mode: %s."
msgstr ""
-#: remote.c:919
+#: remote.c:923
msgid "Argument required (integer, `fixed' or `limited')."
msgstr ""
-#: remote.c:932
+#: remote.c:936
#, possible-c-format
msgid "Invalid %s (bad syntax)."
msgstr ""
-#: remote.c:939
+#: remote.c:943
#, possible-c-format
msgid "Invalid %s (too large)."
msgstr ""
-#: remote.c:945
+#: remote.c:949
#, possible-c-format
msgid ""
"The target may not be able to correctly handle a %s\n"
"of %ld bytes. Change the packet size? "
msgstr ""
-#: remote.c:948
+#: remote.c:952
msgid "Packet size not changed."
msgstr ""
-#: remote.c:958
+#: remote.c:962
#, possible-c-format
msgid "The %s is %ld. "
msgstr ""
-#: remote.c:960
+#: remote.c:964
#, possible-c-format
msgid "Packets are fixed at %ld bytes.\n"
msgstr ""
-#: remote.c:963
+#: remote.c:967
#, possible-c-format
msgid "Packets are limited to %ld bytes.\n"
msgstr ""
-#: remote.c:1087
+#: remote.c:1091
#, possible-c-format
msgid "Support for the `%s' packet is auto-detected, currently %s.\n"
msgstr ""
-#: remote.c:1093
+#: remote.c:1097
#, possible-c-format
msgid "Support for the `%s' packet is currently %s.\n"
msgstr ""
-#: remote.c:1188
+#: remote.c:1192
msgid "packet_ok: attempt to use a disabled packet"
msgstr ""
#. If the stub previously indicated that the packet was
#. supported then there is a protocol error..
-#: remote.c:1202
+#: remote.c:1206
#, possible-c-format
msgid "Protocol error: %s (%s) conflicting enabled responses."
msgstr ""
#. The user set it wrong.
-#: remote.c:1206
+#: remote.c:1210
#, possible-c-format
msgid "Enabled packet %s (%s) not recognized by stub"
msgstr ""
-#: remote.c:1295 remote.c:1316
+#: remote.c:1299 remote.c:1320
#, possible-c-format
msgid "Could not find config for %s"
msgstr ""
@@ -18075,39 +18075,39 @@
#. Error of some sort.
#. We're out of sync with the target now. Did it continue or
#. not? Not is more likely, so report a stop.
-#: remote.c:1433 remote.c:2827 remote.c:2867 remote.c:2984 remote.c:3886
-#: remote.c:5464 remote.c:5563 remote.c:6783
+#: remote.c:1437 remote.c:2831 remote.c:2871 remote.c:2988 remote.c:3902
+#: remote.c:5480 remote.c:5579 remote.c:6799
#, possible-c-format
msgid "Remote failure reply: %s"
msgstr ""
-#: remote.c:1912
+#: remote.c:1916
#, possible-c-format
msgid "invalid remote ptid: %s"
msgstr ""
-#: remote.c:2243
+#: remote.c:2247
msgid "Incomplete response to threadinfo request."
msgstr ""
#. This is an answer to a different request.
-#: remote.c:2246
+#: remote.c:2250
msgid "ERROR RMT Thread info mismatch."
msgstr ""
-#: remote.c:2260
+#: remote.c:2264
msgid "ERROR RMT: threadinfo tag mismatch."
msgstr ""
-#: remote.c:2268
+#: remote.c:2272
msgid "ERROR RMT: length of threadid is not 16."
msgstr ""
-#: remote.c:2283
+#: remote.c:2287
msgid "ERROR RMT: 'exists' length too long."
msgstr ""
-#: remote.c:2307
+#: remote.c:2311
msgid "ERROR RMT: unknown thread info tag."
msgstr ""
@@ -18119,740 +18119,740 @@
#. exit
#. wait for packet, then exit
#.
-#: remote.c:2411
+#: remote.c:2415
msgid "HMM: threadlist did not echo arg thread, dropping it."
msgstr ""
-#: remote.c:2418
+#: remote.c:2422
msgid "RMT ERROR : failed to get remote thread list."
msgstr ""
-#: remote.c:2426
+#: remote.c:2430
msgid "RMT ERROR: threadlist response longer than requested."
msgstr ""
-#: remote.c:2463
+#: remote.c:2467
msgid "Remote fetch threadlist -infinite loop-."
msgstr ""
#. paranoia
-#: remote.c:2628
+#: remote.c:2632
msgid "Command can only be used when connected to the remote target."
msgstr ""
-#: remote.c:2645
+#: remote.c:2649
msgid "threads"
msgstr ""
-#: remote.c:2744
+#: remote.c:2748
msgid "remote_threads_extra_info"
msgstr ""
-#: remote.c:3019 remote.c:3046
+#: remote.c:3023 remote.c:3050
#, possible-c-format
msgid "Target reported unsupported offsets: %s"
msgstr ""
-#: remote.c:3044
+#: remote.c:3048
#, possible-c-format
msgid "Malformed response to offset query, %s"
msgstr ""
-#: remote.c:3092
+#: remote.c:3096
msgid "Can not handle qOffsets TextSeg response with this symbol file"
msgstr ""
-#: remote.c:3224
+#: remote.c:3232
msgid "Non-stop mode requested, but remote does not support non-stop"
msgstr ""
-#: remote.c:3231
+#: remote.c:3239
#, possible-c-format
msgid "Remote refused setting non-stop mode with: %s"
msgstr ""
-#: remote.c:3247
+#: remote.c:3255
#, possible-c-format
msgid "Remote refused setting all-stop mode with: %s"
msgstr ""
-#: remote.c:3259 remote.c:3365
+#: remote.c:3267 remote.c:3374
msgid "The target is not running (try extended-remote?)"
msgstr ""
-#: remote.c:3380
+#: remote.c:3390
msgid "remote didn't report the current thread in non-stop mode"
msgstr ""
-#: remote.c:3407
+#: remote.c:3417
msgid "Trace is already running on the target.\n"
msgstr ""
-#: remote.c:3532
+#: remote.c:3548
msgid ""
"The remote protocol may be unreliable over UDP.\n"
"Some events may be lost, rendering further debugging impossible."
msgstr ""
-#: remote.c:3568
+#: remote.c:3584
#, possible-c-format
msgid "Remote refused setting permissions with: %s"
msgstr ""
-#: remote.c:3605
+#: remote.c:3621
#, possible-c-format
msgid "Remote qSupported response supplied an unexpected value for \"%s\"."
msgstr ""
-#: remote.c:3629
+#: remote.c:3645
#, possible-c-format
msgid "Remote target reported \"%s\" without a size."
msgstr ""
-#: remote.c:3638
+#: remote.c:3654
#, possible-c-format
msgid "Remote target reported \"%s\" with a bad size: \"%s\"."
msgstr ""
-#: remote.c:3645
+#: remote.c:3661
#, possible-c-format
msgid "limiting remote suggested packet size (%d bytes) to %d"
msgstr ""
-#: remote.c:3916
+#: remote.c:3932
msgid "empty item in \"qSupported\" response"
msgstr ""
-#: remote.c:3947
+#: remote.c:3963
#, possible-c-format
msgid "unrecognized item \"%s\" in \"qSupported\" response"
msgstr ""
-#: remote.c:3995
+#: remote.c:4011
msgid ""
"To open a remote debug connection, you need to specify what\n"
"serial device is attached to the remote system\n"
"(e.g. /dev/ttyS0, /dev/ttya, COM1, etc.)."
msgstr ""
-#: remote.c:4010
+#: remote.c:4026
msgid "Already connected to a remote target. Disconnect? "
msgstr ""
-#: remote.c:4013
+#: remote.c:4029
msgid "Still connected."
msgstr ""
-#: remote.c:4167 remote-mips.c:1744
+#: remote.c:4183 remote-mips.c:1744
msgid "Argument given to \"detach\" when remotely debugging."
msgstr ""
-#: remote.c:4170
+#: remote.c:4186
msgid "No process to detach from."
msgstr ""
-#: remote.c:4184
+#: remote.c:4200
msgid "Remote doesn't know how to detach"
msgstr ""
-#: remote.c:4186
+#: remote.c:4202
msgid "Can't detach process."
msgstr ""
-#: remote.c:4191
+#: remote.c:4207
#, possible-c-format
msgid "Detached from remote %s.\n"
msgstr ""
-#: remote.c:4196
+#: remote.c:4212
msgid "Detached from remote process.\n"
msgstr ""
-#: remote.c:4198
+#: remote.c:4214
msgid "Ending remote debugging.\n"
msgstr ""
-#: remote.c:4224
+#: remote.c:4240
msgid "Argument given to \"disconnect\" when remotely debugging."
msgstr ""
-#: remote.c:4251 remote.c:4276
+#: remote.c:4267 remote.c:4292
msgid "This target does not support attaching to a process"
msgstr ""
-#: remote.c:4261
+#: remote.c:4277
#, possible-c-format
msgid "Attached to %s\n"
msgstr ""
-#: remote.c:4271
+#: remote.c:4287
#, possible-c-format
msgid "Attaching to %s failed with: %s"
msgstr ""
-#: remote.c:4278
+#: remote.c:4294
#, possible-c-format
msgid "Attaching to %s failed"
msgstr ""
-#: remote.c:4361
+#: remote.c:4377
#, possible-c-format
msgid "Reply contains invalid hex digit %d"
msgstr ""
-#: remote.c:4577
+#: remote.c:4593
#, possible-c-format
msgid "Unexpected vCont reply in non-stop mode: %s"
msgstr ""
-#: remote.c:4617
+#: remote.c:4633
#, possible-c-format
msgid " - Can't pass signal %d to target in reverse: ignored."
msgstr ""
-#: remote.c:4622
+#: remote.c:4638
msgid "Remote reverse-step not supported."
msgstr ""
-#: remote.c:4625
+#: remote.c:4641
msgid "Remote reverse-continue not supported."
msgstr ""
-#: remote.c:4763
+#: remote.c:4779
msgid "Remote server does not support stopping threads"
msgstr ""
-#: remote.c:4796
+#: remote.c:4812
#, possible-c-format
msgid "Stopping %s failed: %s"
msgstr ""
-#: remote.c:5153
+#: remote.c:5169
#, possible-c-format
msgid ""
"Malformed packet(a) (missing colon): %s\n"
"Packet: '%s'\n"
msgstr ""
-#: remote.c:5209
+#: remote.c:5225
#, possible-c-format
msgid ""
"Malformed packet(b) (missing colon): %s\n"
"Packet: '%s'\n"
msgstr ""
-#: remote.c:5215
+#: remote.c:5231
#, possible-c-format
msgid ""
"Remote sent bad register number %s: %s\n"
"Packet: '%s'\n"
msgstr ""
-#: remote.c:5227
+#: remote.c:5243
#, possible-c-format
msgid "Remote reply is too short: %s"
msgstr ""
-#: remote.c:5233
+#: remote.c:5249
#, possible-c-format
msgid ""
"Remote register badly formatted: %s\n"
"here: %s"
msgstr ""
-#: remote.c:5295 remote.c:5298
+#: remote.c:5311 remote.c:5314
#, possible-c-format
msgid "unknown stop reply packet: %s"
msgstr ""
-#: remote.c:5305
+#: remote.c:5321
#, possible-c-format
msgid "No process or thread specified in stop reply: %s"
msgstr ""
-#: remote.c:5470 remote.c:5612
+#: remote.c:5486 remote.c:5628
#, possible-c-format
msgid "Invalid remote reply: %s"
msgstr ""
-#: remote.c:5699
+#: remote.c:5715
#, possible-c-format
msgid "Could not fetch register \"%s\"; remote failure reply '%s'"
msgstr ""
-#: remote.c:5718
+#: remote.c:5734
msgid "fetch_register_using_p: early buf termination"
msgstr ""
-#: remote.c:5756
+#: remote.c:5772
#, possible-c-format
msgid "Remote 'g' packet reply is of odd length: %s"
msgstr ""
-#: remote.c:5775
+#: remote.c:5791
#, possible-c-format
msgid "Remote 'g' packet reply is too long: %s"
msgstr ""
-#: remote.c:5818 remote.c:5836
+#: remote.c:5834 remote.c:5852
msgid "unexpected end of 'g' packet reply"
msgstr ""
-#: remote.c:5877
+#: remote.c:5893
msgid "could not set remote traceframe"
msgstr ""
-#: remote.c:5985
+#: remote.c:6001
#, possible-c-format
msgid "Could not write register \"%s\"; remote failure reply '%s'"
msgstr ""
-#: remote.c:5990
+#: remote.c:6006
msgid "Bad result from packet_ok"
msgstr ""
-#: remote.c:6031
+#: remote.c:6047
#, possible-c-format
msgid "Could not write registers; remote failure reply '%s'"
msgstr ""
-#: remote.c:6211
+#: remote.c:6227
msgid "Received too much data from remote target; ignoring overflow."
msgstr ""
-#: remote.c:6228
+#: remote.c:6244
msgid "Unmatched escape character in target response."
msgstr ""
-#: remote.c:6327
+#: remote.c:6343
msgid "remote_write_bytes_aux: bad packet format"
msgstr ""
-#: remote.c:6374
+#: remote.c:6390
msgid "minimum packet size too small to write data"
msgstr ""
-#: remote.c:6490
+#: remote.c:6506
msgid "remote_write_bytes: bad internal state"
msgstr ""
-#: remote.c:6640
+#: remote.c:6656
msgid "Too long remote packet."
msgstr ""
-#: remote.c:6643 remote.c:8556
+#: remote.c:6659 remote.c:8572
msgid "Communication problem with target."
msgstr ""
-#: remote.c:6682
+#: remote.c:6698
msgid "Remote target does not support flash erase"
msgstr ""
-#: remote.c:6684
+#: remote.c:6700
msgid "Error erasing flash with vFlashErase packet"
msgstr ""
-#: remote.c:6724
+#: remote.c:6740
msgid "Remote target does not support vFlashDone"
msgstr ""
-#: remote.c:6726
+#: remote.c:6742
msgid "Error finishing flash operation"
msgstr ""
-#: remote.c:6757 remote-m32r-sdi.c:725 remote-m32r-sdi.c:731
+#: remote.c:6773 remote-m32r-sdi.c:725 remote-m32r-sdi.c:731
#: remote-m32r-sdi.c:747
msgid "Remote connection closed"
msgstr ""
-#: remote.c:6761
+#: remote.c:6777
msgid "Remote communication error. Target disconnected."
msgstr ""
-#: remote.c:6850
+#: remote.c:6866
msgid "Cannot execute this command while the target is running."
msgstr ""
-#: remote.c:6890
+#: remote.c:6906
msgid "putpkt: write failed"
msgstr ""
-#: remote.c:7176
+#: remote.c:7192
#, possible-c-format
msgid "Invalid run length encoding: %s\n"
msgstr ""
-#: remote.c:7282
+#: remote.c:7298
msgid "Watchdog timeout has expired. Target detached."
msgstr ""
#. We have tried hard enough, and just can't receive the
#. packet/notification. Give up.
-#: remote.c:7303
+#: remote.c:7319
msgid "Ignoring packet error, continuing...\n"
msgstr ""
-#: remote.c:7439
+#: remote.c:7455
msgid "Can't kill process"
msgstr ""
-#: remote.c:7547
+#: remote.c:7563
msgid "Target does not support QDisableRandomization."
msgstr ""
-#: remote.c:7549
+#: remote.c:7565
#, possible-c-format
msgid "Bogus QDisableRandomization reply from target: %s"
msgstr ""
-#: remote.c:7567
+#: remote.c:7583
msgid "Remote file name too long for run packet"
msgstr ""
-#: remote.c:7582
+#: remote.c:7598
msgid "Argument list too long for run packet"
msgstr ""
-#: remote.c:7605
+#: remote.c:7621
msgid ""
"Running the default executable on the remote target failed; try \"set remote "
"exec-file\"?"
msgstr ""
-#: remote.c:7608
+#: remote.c:7624
#, possible-c-format
msgid "Running \"%s\" on the remote target failed"
msgstr ""
-#: remote.c:7638
+#: remote.c:7654
msgid "Remote target does not support \"set remote exec-file\""
msgstr ""
-#: remote.c:7640
+#: remote.c:7656
msgid "Remote target does not support \"set args\" or run <ARGS>"
msgstr ""
-#: remote.c:7772
+#: remote.c:7788
#, possible-c-format
msgid "hw_bp_to_z: bad watchpoint type %d"
msgstr ""
-#: remote.c:7806
+#: remote.c:7822
msgid "remote_insert_watchpoint: reached end of function"
msgstr ""
-#: remote.c:7838
+#: remote.c:7854
msgid "remote_remove_watchpoint: reached end of function"
msgstr ""
-#: remote.c:7946
+#: remote.c:7962
msgid "remote_insert_hw_breakpoint: reached end of function"
msgstr ""
-#: remote.c:7981
+#: remote.c:7997
msgid "remote_remove_hw_breakpoint: reached end of function"
msgstr ""
-#: remote.c:8038
+#: remote.c:8054
msgid "remote target does not support this operation"
msgstr ""
-#: remote.c:8066
+#: remote.c:8082
msgid "command cannot be used without an exec file"
msgstr ""
-#: remote.c:8091
+#: remote.c:8107
#, possible-c-format
msgid "target memory fault, section %s, range %s -- %s"
msgstr ""
-#: remote.c:8109
+#: remote.c:8125
msgid ""
"One or more sections of the remote executable does not match\n"
"the loaded file\n"
msgstr ""
-#: remote.c:8112
+#: remote.c:8128
#, possible-c-format
msgid "No loaded section named '%s'.\n"
msgstr ""
-#: remote.c:8212
+#: remote.c:8228
#, possible-c-format
msgid "Unknown remote qXfer reply: %s"
msgstr ""
-#: remote.c:8218
+#: remote.c:8234
msgid "Remote qXfer reply contained no data."
msgstr ""
-#: remote.c:8407
+#: remote.c:8423
msgid "remote query is only available after target open"
msgstr ""
-#: remote.c:8498
+#: remote.c:8514
msgid "Pattern is too large to transmit to remote target."
msgstr ""
-#: remote.c:8520 remote.c:8525
+#: remote.c:8536 remote.c:8541
#, possible-c-format
msgid "Unknown qSearch:memory reply: %s"
msgstr ""
-#: remote.c:8538
+#: remote.c:8554
msgid "remote rcmd is only available after target open"
msgstr ""
-#: remote.c:8550
+#: remote.c:8566
#, possible-c-format
msgid "\"monitor\" command ``%s'' is too long."
msgstr ""
-#: remote.c:8568 remote.c:9811 remote.c:10084 remote.c:10174 remote.c:10274
-#: remote.c:10321 remote.c:10398 remote.c:10460 remote.c:10488
+#: remote.c:8584 remote.c:9827 remote.c:10110 remote.c:10200 remote.c:10300
+#: remote.c:10347 remote.c:10424 remote.c:10486 remote.c:10514
msgid "Target does not support this command."
msgstr ""
-#: remote.c:8579
+#: remote.c:8595
msgid "Protocol error with Rcmd"
msgstr ""
-#: remote.c:8615 remote.c:9514 remote.c:9602 remote.c:9653
+#: remote.c:8631 remote.c:9530 remote.c:9618 remote.c:9669
msgid "command can only be used with remote target"
msgstr ""
-#: remote.c:8618
+#: remote.c:8634
msgid "remote-packet command requires packet text as argument"
msgstr ""
-#: remote.c:8659
+#: remote.c:8675
msgid "Remote threadset test\n"
msgstr ""
-#: remote.c:8765
+#: remote.c:8781
msgid "Fetch and print the remote list of thread identifiers, one pkt only"
msgstr ""
-#: remote.c:8768
+#: remote.c:8784
msgid "Fetch and display info about one thread"
msgstr ""
-#: remote.c:8770
+#: remote.c:8786
msgid "Test setting to a different thread"
msgstr ""
-#: remote.c:8772
+#: remote.c:8788
msgid "Iterate through updating all remote thread info"
msgstr ""
-#: remote.c:8774
+#: remote.c:8790
msgid " Remote thread alive test "
msgstr ""
-#: remote.c:8859
+#: remote.c:8875
msgid "Remote target doesn't support qGetTLSAddr packet"
msgstr ""
-#: remote.c:8862
+#: remote.c:8878
msgid "Remote target failed to process qGetTLSAddr request"
msgstr ""
-#: remote.c:8866
+#: remote.c:8882
msgid "TLS not supported or disabled on this target"
msgstr ""
-#: remote.c:8903
+#: remote.c:8919
msgid "Remote target doesn't support qGetTIBAddr packet"
msgstr ""
-#: remote.c:8905
+#: remote.c:8921
msgid "Remote target failed to process qGetTIBAddr request"
msgstr ""
-#: remote.c:8908
+#: remote.c:8924
msgid "qGetTIBAddr not supported or disabled on this target"
msgstr ""
-#: remote.c:8956
+#: remote.c:8972
#, possible-c-format
msgid "Duplicate g packet description added for size %d"
msgstr ""
-#: remote.c:9023 remote.c:9044 remote.c:9066
+#: remote.c:9039 remote.c:9060 remote.c:9082
msgid "Packet too long for target."
msgstr ""
-#: remote.c:9298
+#: remote.c:9314
#, possible-c-format
msgid "Read returned %d, but %d bytes."
msgstr ""
-#: remote.c:9397
+#: remote.c:9413
#, possible-c-format
msgid "Unknown remote I/O error %d"
msgstr ""
-#: remote.c:9399
+#: remote.c:9415
#, possible-c-format
msgid "Remote I/O error: %s"
msgstr ""
-#: remote.c:9548
+#: remote.c:9564
#, possible-c-format
msgid "Error reading %s."
msgstr ""
-#: remote.c:9571
+#: remote.c:9587
#, possible-c-format
msgid "Remote write of %d bytes returned 0!"
msgstr ""
-#: remote.c:9588
+#: remote.c:9604
#, possible-c-format
msgid "Successfully sent file \"%s\".\n"
msgstr ""
-#: remote.c:9643
+#: remote.c:9659
#, possible-c-format
msgid "Successfully fetched file \"%s\".\n"
msgstr ""
-#: remote.c:9660
+#: remote.c:9676
#, possible-c-format
msgid "Successfully deleted file \"%s\".\n"
msgstr ""
-#: remote.c:9670
+#: remote.c:9686
msgid "file to put"
msgstr ""
-#: remote.c:9675
+#: remote.c:9691
msgid "Invalid parameters to remote put"
msgstr ""
-#: remote.c:9689
+#: remote.c:9705
msgid "file to get"
msgstr ""
-#: remote.c:9694
+#: remote.c:9710
msgid "Invalid parameters to remote get"
msgstr ""
-#: remote.c:9708
+#: remote.c:9724
msgid "file to delete"
msgstr ""
-#: remote.c:9713
+#: remote.c:9729
msgid "Invalid parameters to remote delete"
msgstr ""
-#: remote.c:9856 remote.c:9871 remote.c:10030 remote.c:10041
+#: remote.c:9872 remote.c:9887 remote.c:10046 remote.c:10057
msgid "Target does not support source download."
msgstr ""
-#: remote.c:9923
+#: remote.c:9939
msgid "Fast tracepoint not valid during download"
msgstr ""
#. Fast tracepoints are functionally identical to regular
#. tracepoints, so don't take lack of support as a reason to
#. give up on the trace run.
-#: remote.c:9930
+#: remote.c:9946
#, possible-c-format
msgid ""
"Target does not support fast tracepoints, downloading %d as regular "
"tracepoint"
msgstr ""
-#: remote.c:9944
+#: remote.c:9960
msgid "Static tracepoint not valid during download"
msgstr ""
#. Fast tracepoints are functionally identical to regular
#. tracepoints, so don't take lack of support as a reason
#. to give up on the trace run.
-#: remote.c:9950
+#: remote.c:9966
msgid "Target does not support static tracepoints"
msgstr ""
-#: remote.c:9970
+#: remote.c:9986
#, possible-c-format
msgid "Target does not support conditional tracepoints, ignoring tp %d cond"
msgstr ""
-#: remote.c:9979
+#: remote.c:9995
msgid "Target does not support tracepoints."
msgstr ""
-#: remote.c:9996 remote.c:10013
+#: remote.c:10012 remote.c:10029
msgid "Error on target while setting tracepoints."
msgstr ""
-#: remote.c:10078
+#: remote.c:10104
msgid "Trace state variable name too long for tsv definition packet"
msgstr ""
-#: remote.c:10086
+#: remote.c:10112
msgid "Error on target while downloading trace state variable."
msgstr ""
-#: remote.c:10100
+#: remote.c:10126
msgid ""
"Target does not support enabling tracepoints while a trace run is ongoing."
msgstr ""
-#: remote.c:10102
+#: remote.c:10128
msgid "Error on target while enabling tracepoint."
msgstr ""
-#: remote.c:10116
+#: remote.c:10142
msgid ""
"Target does not support disabling tracepoints while a trace run is ongoing."
msgstr ""
-#: remote.c:10118
+#: remote.c:10144
msgid "Error on target while disabling tracepoint."
msgstr ""
-#: remote.c:10154
+#: remote.c:10180
msgid "Too many sections for read-only sections definition packet."
msgstr ""
-#: remote.c:10176 remote.c:10276 remote.c:10346 remote.c:10349 remote.c:10400
-#: remote.c:10462 remote.c:10490 remote.c:10579
+#: remote.c:10202 remote.c:10302 remote.c:10372 remote.c:10375 remote.c:10426
+#: remote.c:10488 remote.c:10516 remote.c:10605
#, possible-c-format
msgid "Bogus reply from target: %s"
msgstr ""
-#: remote.c:10216
+#: remote.c:10242
#, possible-c-format
msgid "Bogus trace status reply from target: %s"
msgstr ""
-#: remote.c:10315
+#: remote.c:10341
#, possible-c-format
msgid "Unknown trace find type %d"
msgstr ""
-#: remote.c:10330
+#: remote.c:10356
msgid "Unable to parse trace frame number"
msgstr ""
-#: remote.c:10340
+#: remote.c:10366
msgid "Unable to parse tracepoint number"
msgstr ""
-#: remote.c:10392
+#: remote.c:10418
msgid "Remote file name too long for trace save packet"
msgstr ""
-#: remote.c:10465
+#: remote.c:10491
msgid "Target does not support disconnected tracing."
msgstr ""
#. set/show remote ...
#. allow-unknown
-#: remote.c:10918 remote.c:10924
+#: remote.c:10944 remote.c:10950
msgid ""
"Remote protocol specific variables\n"
"Configure various remote-protocol specific variables such as\n"
@@ -18860,13 +18860,13 @@
msgstr ""
#. allow-unknown
-#: remote.c:10931
+#: remote.c:10957
msgid ""
"Compare section data on target to the exec file.\n"
"Argument is a single section name (default: all loaded sections)."
msgstr ""
-#: remote.c:10936
+#: remote.c:10962
msgid ""
"Send an arbitrary packet to a remote target.\n"
" maintenance packet TEXT\n"
@@ -18876,57 +18876,57 @@
"terminating `#' character and checksum."
msgstr ""
-#: remote.c:10945
+#: remote.c:10971
msgid "Set whether to send break if interrupted."
msgstr ""
-#: remote.c:10946
+#: remote.c:10972
msgid "Show whether to send break if interrupted."
msgstr ""
-#: remote.c:10947
+#: remote.c:10973
msgid "If set, a break, instead of a cntrl-c, is sent to the remote target."
msgstr ""
-#: remote.c:10960
+#: remote.c:10986
msgid "Set interrupt sequence to remote target."
msgstr ""
-#: remote.c:10961
+#: remote.c:10987
msgid "Show interrupt sequence to remote target."
msgstr ""
-#: remote.c:10962
+#: remote.c:10988
msgid ""
"Valid value is \"Ctrl-C\", \"BREAK\" or \"BREAK-g\". The default is \"Ctrl-C"
"\"."
msgstr ""
-#: remote.c:10969
+#: remote.c:10995
msgid ""
"Set whether interrupt-sequence is sent to remote target when gdb connects to."
msgstr ""
-#: remote.c:10970
+#: remote.c:10996
msgid ""
"\t\tShow whether interrupt-sequence is sent to remote target when gdb "
"connects to."
msgstr ""
-#: remote.c:10971
+#: remote.c:10997
msgid "\t\tIf set, interrupt sequence is sent to remote target."
msgstr ""
#. Install commands for configuring memory read/write packets.
-#: remote.c:10978
+#: remote.c:11004
msgid "Set the maximum number of bytes per memory write packet (deprecated)."
msgstr ""
-#: remote.c:10981
+#: remote.c:11007
msgid "Show the maximum number of bytes per memory write packet (deprecated)."
msgstr ""
-#: remote.c:10985
+#: remote.c:11011
msgid ""
"Set the maximum number of bytes per memory-write packet.\n"
"Specify the number of bytes in a packet or 0 (zero) for the\n"
@@ -18935,7 +18935,7 @@
"further restriction and ``limit'' to enable that restriction."
msgstr ""
-#: remote.c:10993
+#: remote.c:11019
msgid ""
"Set the maximum number of bytes per memory-read packet.\n"
"Specify the number of bytes in a packet or 0 (zero) for the\n"
@@ -18944,87 +18944,87 @@
"further restriction and ``limit'' to enable that restriction."
msgstr ""
-#: remote.c:11002
+#: remote.c:11028
msgid "Show the maximum number of bytes per memory-write packet."
msgstr ""
-#: remote.c:11006
+#: remote.c:11032
msgid "Show the maximum number of bytes per memory-read packet."
msgstr ""
-#: remote.c:11010
+#: remote.c:11036
msgid "Set the maximum number of target hardware watchpoints."
msgstr ""
-#: remote.c:11011
+#: remote.c:11037
msgid "Show the maximum number of target hardware watchpoints."
msgstr ""
-#: remote.c:11012 remote.c:11021 remote.c:11030
+#: remote.c:11038 remote.c:11047 remote.c:11056
msgid "Specify a negative limit for unlimited."
msgstr ""
-#: remote.c:11019
+#: remote.c:11045
msgid "Set the maximum length (in bytes) of a target hardware watchpoint."
msgstr ""
-#: remote.c:11020
+#: remote.c:11046
msgid "Show the maximum length (in bytes) of a target hardware watchpoint."
msgstr ""
-#: remote.c:11028
+#: remote.c:11054
msgid "Set the maximum number of target hardware breakpoints."
msgstr ""
-#: remote.c:11029
+#: remote.c:11055
msgid "Show the maximum number of target hardware breakpoints."
msgstr ""
-#: remote.c:11038
+#: remote.c:11064
msgid "Set the maximum size of the address (in bits) in a memory packet."
msgstr ""
-#: remote.c:11039
+#: remote.c:11065
msgid "Show the maximum size of the address (in bits) in a memory packet."
msgstr ""
-#: remote.c:11197
+#: remote.c:11223
msgid "Set use of remote protocol `Z' packets"
msgstr ""
-#: remote.c:11198
+#: remote.c:11224
msgid "Show use of remote protocol `Z' packets "
msgstr ""
-#: remote.c:11199
+#: remote.c:11225
msgid ""
"When set, GDB will attempt to use the remote breakpoint and watchpoint\n"
"packets."
msgstr ""
-#: remote.c:11208
+#: remote.c:11234
msgid ""
"Manipulate files on the remote system\n"
"Transfer files to and from the remote target system."
msgstr ""
-#: remote.c:11215
+#: remote.c:11241
msgid "Copy a local file to the remote system."
msgstr ""
-#: remote.c:11219
+#: remote.c:11245
msgid "Copy a remote file to the local system."
msgstr ""
-#: remote.c:11223
+#: remote.c:11249
msgid "Delete a remote file."
msgstr ""
-#: remote.c:11228
+#: remote.c:11254
msgid "Set the remote pathname for \"run\""
msgstr ""
-#: remote.c:11229
+#: remote.c:11255
msgid "Show the remote pathname for \"run\""
msgstr ""
diff --git a/gdb/python/py-breakpoint.c b/gdb/python/py-breakpoint.c
index 195ed2b..0c84d03 100644
--- a/gdb/python/py-breakpoint.c
+++ b/gdb/python/py-breakpoint.c
@@ -627,7 +627,7 @@
0,
AUTO_BOOLEAN_TRUE,
&bkpt_breakpoint_ops,
- 0, 1, internal_bp);
+ 0, 1, internal_bp, 0);
break;
}
case bp_watchpoint:
diff --git a/gdb/python/py-finishbreakpoint.c b/gdb/python/py-finishbreakpoint.c
index b0c16b5..e083576 100644
--- a/gdb/python/py-finishbreakpoint.c
+++ b/gdb/python/py-finishbreakpoint.c
@@ -288,7 +288,7 @@
0,
AUTO_BOOLEAN_TRUE,
&bkpt_breakpoint_ops,
- 0, 1, internal_bp);
+ 0, 1, internal_bp, 0);
}
GDB_PY_SET_HANDLE_EXCEPTION (except);
diff --git a/gdb/remote.c b/gdb/remote.c
index 60d7ecd..04b818f 100644
--- a/gdb/remote.c
+++ b/gdb/remote.c
@@ -271,6 +271,10 @@
char *buf;
long buf_size;
+ /* True if we're going through initial connection setup (finding out
+ about the remote side's threads, relocating symbols, etc.). */
+ int starting_up;
+
/* If we negotiated packet size explicitly (and thus can bypass
heuristics for the largest packet size that will not overflow
a buffer in the stub), this will be set to that packet size.
@@ -3164,6 +3168,10 @@
/* Ack any packet which the remote side has already sent. */
serial_write (remote_desc, "+", 1);
+ /* Signal other parts that we're going through the initial setup,
+ and so things may not be stable yet. */
+ rs->starting_up = 1;
+
/* The first packet we send to the target is the optional "supported
packets" request. If the target can answer this, it will tell us
which later probes to skip. */
@@ -3260,6 +3268,7 @@
/* We're connected, but not running. Drop out before we
call start_remote. */
+ rs->starting_up = 0;
return;
}
else
@@ -3366,6 +3375,7 @@
/* We're connected, but not running. Drop out before we
call start_remote. */
+ rs->starting_up = 0;
return;
}
@@ -3418,6 +3428,12 @@
merge_uploaded_tracepoints (&uploaded_tps);
}
+ /* The thread and inferior lists are now synchronized with the
+ target, our symbols have been relocated, and we're merged the
+ target's tracepoints with ours. We're done with basic start
+ up. */
+ rs->starting_up = 0;
+
/* If breakpoints are global, insert them now. */
if (gdbarch_has_global_breakpoints (target_gdbarch)
&& breakpoints_always_inserted_mode ())
@@ -10050,8 +10066,18 @@
static int
remote_can_download_tracepoint (void)
{
- struct trace_status *ts = current_trace_status ();
- int status = remote_get_trace_status (ts);
+ struct remote_state *rs = get_remote_state ();
+ struct trace_status *ts;
+ int status;
+
+ /* Don't try to install tracepoints until we've relocated our
+ symbols, and fetched and merged the target's tracepoint list with
+ ours. */
+ if (rs->starting_up)
+ return 0;
+
+ ts = current_trace_status ();
+ status = remote_get_trace_status (ts);
if (status == -1 || !ts->running_known || !ts->running)
return 0;
diff --git a/gdb/spu-tdep.c b/gdb/spu-tdep.c
index 17dae90..78ba007 100644
--- a/gdb/spu-tdep.c
+++ b/gdb/spu-tdep.c
@@ -1947,7 +1947,7 @@
0 /* ignore_count */,
AUTO_BOOLEAN_FALSE /* pending_break_support */,
&bkpt_breakpoint_ops /* ops */, 0 /* from_tty */,
- 1 /* enabled */, 0 /* internal */);
+ 1 /* enabled */, 0 /* internal */, 0);
}
diff --git a/gdb/version.in b/gdb/version.in
index 37722eb..815da58 100644
--- a/gdb/version.in
+++ b/gdb/version.in
@@ -1 +1 @@
-7.4
+7.4.1
diff --git a/md5.sum b/md5.sum
index fbd93c3..d451152 100644
--- a/md5.sum
+++ b/md5.sum
@@ -450,7 +450,7 @@
39f61ac0fb56eced56e6894e7bc47cef bfd/doc/header.sed
5fa24958e8a60b2f879af658e615ccc0 bfd/doc/makefile.vms
d7a37304ccd7b245f93df4be02797477 bfd/doc/proto.str
-2b6488ed7b69a42f30343be7198989ea bfd/doc/bfdver.texi
+86cc3f1170e71432f8c814bca7de35d5 bfd/doc/bfdver.texi
b1848292a4811cd7301fc6201debe63a bfd/doc/aoutx.texi
1ec269e34cd7de48135ce9d4aefb98b6 bfd/doc/archive.texi
197c39bd6f28ed23c62dac11a648c77f bfd/doc/archures.texi
@@ -686,7 +686,7 @@
00708d79997ccea662940ac0766199d4 gdb/.gitignore
3e085b17b51d615c12da7b4a99492d1d gdb/CONTRIBUTE
d32239bcb673463ab874e80d47fae504 gdb/COPYING
-c052b199c5435670abd8dea74ac0f320 gdb/ChangeLog
+ace056f9fe75c9baad5a50b3c1f7c965 gdb/ChangeLog
42b9f7c51223e595f66c2210064be682 gdb/ChangeLog-1990
8f5a03c189727d347a330548f3ea9c98 gdb/ChangeLog-1991
51d2fa6ce8618d5c87150c7c576f1f6d gdb/ChangeLog-1992
@@ -792,8 +792,8 @@
311d4834750b544b40c8c8533c5fc142 gdb/block.c
12b0711b6fabfc7a0a9317f8ec6c76ca gdb/block.h
996089c64e1ce601b5393710693945c2 gdb/blockframe.c
-ed7f88a46c2d609cf934310a407ec526 gdb/breakpoint.c
-1943a5aee6e04b5dda0ba31bd8f41317 gdb/breakpoint.h
+889fd525008aca5b911f5b12dbdc296a gdb/breakpoint.c
+cae77f8b727294759a4854ae8f905c28 gdb/breakpoint.h
948f4853765807667e49728e96bacc56 gdb/bsd-kvm.c
b5ed82189a99a125cfa8f4223c5c7bc5 gdb/bsd-kvm.h
33cf3cf339daf5497fb4378d752e4d2f gdb/bsd-uthread.c
@@ -820,9 +820,9 @@
7edb456dd3a92b053179651bbb24c88c gdb/complaints.h
3a95be95abfe2c13220c33755f6f9bd0 gdb/completer.c
95b27bbd8303620aa2b6bb2331b2c2a8 gdb/completer.h
-988952496a128fdd96389233bcdacd3c gdb/config.in
-fec4e9f4cb71db654663e0326f6e8f7f gdb/configure
-68dcd9e2d560a2c06f9cb4d147cf2787 gdb/configure.ac
+bd98c674c21d0c46d5bf71adb370bcda gdb/config.in
+10d8c5c1de3098e5e4fc9ee20f78a084 gdb/configure
+3b3447124bce69c6e84f02267dbb3074 gdb/configure.ac
9ed90aedec0635100e1d9dab007e0a68 gdb/configure.host
0c9f5591c7c7d76d47fedb63b262c736 gdb/configure.tgt
af82fbafe700324fba5ab56fedde6d64 gdb/continuations.c
@@ -1003,7 +1003,7 @@
610c54d2f64c62ee2841a5f3f1cc6ab4 gdb/i386obsd-nat.c
ad1a0227ab5618cf99b99defc77e5b49 gdb/i386obsd-tdep.c
6dc92c37afea3134079db7d44626dc46 gdb/i386v4-nat.c
-e18ac387c8c8652e3e32ce6c7244e9ed gdb/i387-tdep.c
+ed09a85f99d152b8f6595285811e47ae gdb/i387-tdep.c
6fd84f2f73947d1f9a69badac39431e8 gdb/i387-tdep.h
67946d50029566cdd23c21431b0d3534 gdb/ia64-hpux-nat.c
127d4e2bda2904e017614cd8139f44b9 gdb/ia64-hpux-tdep.c
@@ -1022,7 +1022,7 @@
c35fd23919a8cca9b4e0d148b4000459 gdb/inf-ttrace.h
39c4979f1e97139d88303becdb1845b3 gdb/infcall.c
56b778f95084e0c4623e87cdb168a776 gdb/infcall.h
-0ab3976e291e9c3f91ce77c801f79232 gdb/infcmd.c
+593f4c6d28dca788b20d2dfdd1e38728 gdb/infcmd.c
f5521d21d0d2dfc6f84b716c9d44917c gdb/inferior.c
0a1f6f277e59361278df54f0679d5c4b gdb/inferior.h
09772df7a350117869dc7dab168a9282 gdb/inflow.c
@@ -1155,7 +1155,7 @@
3c56dde79b6ca2b1a75c2b643d1f2b31 gdb/p-exp.y
aa4dc8c7c4cf02d3ab5487482ece2dec gdb/p-lang.c
7d96ba7326c21b3b7017bdd8a8aacdd8 gdb/p-lang.h
-d72c35115ea262f832e5a5f96521a02b gdb/p-typeprint.c
+2470b01ff4a1f0ab6447a628584d211a gdb/p-typeprint.c
ea5b3277f55bd03998b5bf316521f431 gdb/p-valprint.c
8afa99088c75df0502ec114947e4c4e1 gdb/parse.c
71c3af45133cee23c48518af0275835a gdb/parser-defs.h
@@ -1206,7 +1206,7 @@
6e3352acc620cbef7b2ca57d6dfeeb35 gdb/remote-m32r-sdi.c
e2168e10a3f96685add418e4ebd71cb4 gdb/remote-mips.c
3eb49222d524631dd316722a93557ea7 gdb/remote-sim.c
-02d6856145eaa1ebdc3a806b3a5460e1 gdb/remote.c
+8c56af1536fea367ba083de758632cb7 gdb/remote.c
b63b1f20baf437bbb2fa87e630f3ab9e gdb/remote.h
f06ddee84bfa448102afb491decdaadb gdb/reply_mig_hack.awk
8cd5ccd4b05c5de996101ce08b42aedb gdb/reverse.c
@@ -1297,7 +1297,7 @@
549d0b35739a80f6e5b8e7c52bf4c0e9 gdb/sparcobsd-tdep.c
8dcf88eb43438f9e70bfd9621f4f890e gdb/spu-linux-nat.c
38778d2a021765f273e2ea7daa87f9a6 gdb/spu-multiarch.c
-089d50a5bd789d3cd3531ce0da0b9a66 gdb/spu-tdep.c
+a5df527f7b0e2754239e7bde34ffe918 gdb/spu-tdep.c
b01d53391d1c53810714b24b06c860cc gdb/spu-tdep.h
7e9582b9fbe1646d6654e1383309480d gdb/srec.h
cb727c206887e592b880069e1e6ab264 gdb/stabsread.c
@@ -1358,7 +1358,7 @@
2d3a8dd8020df5ba26f34232fab12279 gdb/vec.c
b03c6cf101ad30bee65195c9f7afc8de gdb/vec.h
fe8a5f81dd9b4284facd03f11f79a03e gdb/version.h
-49a8137046ea585514da374edc475322 gdb/version.in
+6b6ca27c1897d473226f20f54f215bc8 gdb/version.in
db4d8c78647c2420b8a9a978a73627ed gdb/windows-nat.c
187722ce28b0e44661d213c94b2030a3 gdb/windows-nat.h
3ff955d7da99ae492c087979bf3652c0 gdb/windows-tdep.c
@@ -1517,8 +1517,16 @@
6076d300a46651562d4ecd0604442414 gdb/doc/stack_frame.png
553b7fe1bf4b5d8b96fdb8cd83503de1 gdb/doc/stack_frame.svg
f81a0e00e0cb9e41b078069fb9bedb07 gdb/doc/stack_frame.txt
-fe77cdce79793f74899f0ac30bd0406f gdb/doc/gdb.info
-ad6b67a5363321e2be88003344161f43 gdb/doc/gdbint.info
+32f451da2e4c722938ffd253da784318 gdb/doc/gdb.info
+20509215f56bc4061535524841f1d1d9 gdb/doc/gdb.info-1
+2f137ecb4a7ea11d07bb88801e25f0fb gdb/doc/gdb.info-2
+345eb4bec007bfe1dde0947466551232 gdb/doc/gdb.info-3
+f318b34b198be49872c18afd69b492ac gdb/doc/gdb.info-4
+acca72d459d7ce181fa3cdec20497363 gdb/doc/gdb.info-5
+c899397f297f7f95cf19d8d7415cfefa gdb/doc/gdb.info-6
+f57f91ede26642e2a8fb12ce558e39cf gdb/doc/gdbint.info
+dd97188666a9a295463aab8b110e8e48 gdb/doc/gdbint.info-1
+6c9191d631d31b4e9ce4787ebd339d30 gdb/doc/gdbint.info-2
b1c8f301843bd266c184403fb9ef3e37 gdb/doc/stabs.info
ff611a6ef4f4b51d72bc5dd9562b1866 gdb/doc/annotate.info
c0fcb5a1b83fe8682c303a5900e86eac gdb/features/Makefile
@@ -1809,7 +1817,7 @@
c570967ef8896ae2d04557ecc04869a0 gdb/gnulib/m4/wchar_t.m4
ccd9fed60bef4397936592d030d2eb08 gdb/gnulib/m4/wint_t.m4
90b81f951a2351c88c1b4a1fedbb492f gdb/mi/ChangeLog-1999-2003
-fa96ed36a1758b590c85fd645eeee105 gdb/mi/mi-cmd-break.c
+4fa89925a2b1970950976932d253154b gdb/mi/mi-cmd-break.c
0827e8f4645824d0d29164e6e256bb11 gdb/mi/mi-cmd-disas.c
6245fb5753f0177ca6760014bc72f705 gdb/mi/mi-cmd-env.c
47c52f73129733aa2b7f65df19039810 gdb/mi/mi-cmd-file.c
@@ -1825,7 +1833,7 @@
42e03bf4bcb6ef4b93681d84b3eabb2a gdb/mi/mi-getopt.c
84ee5b643f7635ec5812b268f0eefe05 gdb/mi/mi-getopt.h
7e742b5764ee97af000ebbab0332c2c4 gdb/mi/mi-interp.c
-d8afbe16e9ca4e347a5f884719680560 gdb/mi/mi-main.c
+ee6cb3bc178a8bd6b3d5ec6bdd27af08 gdb/mi/mi-main.c
671215a10757e577147d49d6b76b53c2 gdb/mi/mi-main.h
68e8e953d7d459929d8f09efa9f29a6f gdb/mi/mi-out.c
221b1b20bcab5757ffc8565b8ad768e7 gdb/mi/mi-out.h
@@ -1852,11 +1860,11 @@
7cd3745f37bbbfcd24086735939ead52 gdb/osf-share/HP800/cma_thread_io.h
36cb16e3cf86ddd4609d275a6a3052f5 gdb/osf-share/RIOS/cma_thread_io.h
1851bff0653201a488dcae18dde7efad gdb/po/gdbtext
-f356f4ca429d545f539603e884a2c422 gdb/po/gdb.pot
+18fbf78a6d7bd184ea5a132a96e46eed gdb/po/gdb.pot
7d8e9488c01631f6ced7a5ee1abe4e82 gdb/python/py-auto-load.c
c50cdb4ab700237449f27ea7d6b0637b gdb/python/py-block.c
be8cbd2c7ccd83e31f62e01605df83b8 gdb/python/py-bpevent.c
-dda0e1cb6109f6cb34f04d2c01a2cb38 gdb/python/py-breakpoint.c
+fdfa7fb2ef76b8dea2d0a2c0aad8a048 gdb/python/py-breakpoint.c
fef6c273551544195b08180798d25ff6 gdb/python/py-cmd.c
698a44eebf25ce0b09902b1ba4f64fd7 gdb/python/py-continueevent.c
2333c66f4114500b29e956629bd43d70 gdb/python/py-event.c
@@ -1865,7 +1873,7 @@
40ae56eb3dfcebc84d3a9c0f33b84ff3 gdb/python/py-evtregistry.c
70046ad59d23797fb3de152bedd10099 gdb/python/py-evts.c
20202c9e5c2493b0e7f2f070736f2569 gdb/python/py-exitedevent.c
-8bd7ddda44115ac89f3ba352403b10ff gdb/python/py-finishbreakpoint.c
+681bbc34c8b215f6eba58c469f250c5b gdb/python/py-finishbreakpoint.c
cbff3f902f47af733f776e5c60fa9394 gdb/python/py-frame.c
33033c2d859aa201f90cca8f8c28f0f5 gdb/python/py-function.c
a2ca777c5d83c952037f1c3b82241850 gdb/python/py-inferior.c
@@ -4993,15 +5001,15 @@
e063229b2cf1791d2589dd147cfbbe83 sim/avr/configure
8bd719d3c014d2c2d004522bdddfa99f sim/avr/configure.ac
32d79d4cf102b5ad6c4c2745f68ee449 sim/avr/interp.c
-61f7dded6085f72789a9fb1f97bf784e sim/bfin/ChangeLog
+88b3c6f558d1a2bb82e72111f844d2bd sim/bfin/ChangeLog
f7c4ad7755665dab78c17d6388916d4f sim/bfin/Makefile.in
f98ea62fb3f55a9a7de978460c19b0d7 sim/bfin/TODO
e56b6c27ddaaed521429306d131d537a sim/bfin/aclocal.m4
f198125ebd49d034b295a7a7c292cee7 sim/bfin/bfin-sim.c
3a321ec317d271d6e504d103892f69ef sim/bfin/bfin-sim.h
-d2b15b1692a06172dbeb4f5f8934842c sim/bfin/config.in
-531dba58380615e62e5289e521049ac8 sim/bfin/configure
-9cb34ad0c1b5ae5ef031eea2217d17fa sim/bfin/configure.ac
+40e3ad2a04af58806f54123b09b7366a sim/bfin/config.in
+361b05046656ff822012c5bb3740e977 sim/bfin/configure
+5cb7e753f86dfea1f6bf2463a7f34aa3 sim/bfin/configure.ac
a107410d6152155a2504673d5a68b5e2 sim/bfin/devices.c
8eb68c05f5ac0c950187bb69a4409e8c sim/bfin/devices.h
0ff63580a8e5beb2da364a615190757e sim/bfin/dv-bfin_cec.c
@@ -5060,7 +5068,7 @@
b70c691da7250c3f92f16b311fb3d664 sim/bfin/dv-bfin_wdog.h
d4500c8aa6e02de68a52d5688f65d520 sim/bfin/dv-bfin_wp.c
c9099cf44cb70d4647ad4bc4e588cb73 sim/bfin/dv-bfin_wp.h
-3e915f7a459ceaa586e584e7d61de0ee sim/bfin/dv-eth_phy.c
+de93375012a60e62b35fbbae386d7ed8 sim/bfin/dv-eth_phy.c
45f9bb1026267ccc7d9243cf08d61701 sim/bfin/gui.c
da3e7e47b8e62f28716fc770edff8212 sim/bfin/gui.h
a751ed26a3c04c3f39508421dfe815be sim/bfin/insn_list.def
diff --git a/sim/bfin/ChangeLog b/sim/bfin/ChangeLog
index 1376e6b..c79accf 100644
--- a/sim/bfin/ChangeLog
+++ b/sim/bfin/ChangeLog
@@ -1,3 +1,11 @@
+2012-04-12 Mike Frysinger <vapier@gentoo.org>
+
+ * config.in: Regenerate.
+ * configure: Likewise.
+ * configure.ac: Add linux/types.h to AC_CHECK_HEADERS.
+ * dv-eth_phy.c: Check for HAVE_LINUX_TYPES_H, and delete __u16 and
+ _LINUX_TYPES_H defines.
+
2011-12-03 Mike Frysinger <vapier@gentoo.org>
* interp.c (bfin_syscall): Increase _tbuf storage. Declare new local
diff --git a/sim/bfin/config.in b/sim/bfin/config.in
index 2b25645..4175dad 100644
--- a/sim/bfin/config.in
+++ b/sim/bfin/config.in
@@ -1,20 +1,5 @@
/* config.in. Generated from configure.ac by autoheader. */
-/* Define to 1 if NLS is requested. */
-#undef ENABLE_NLS
-
-/* Define as 1 if you have catgets and don't want to use GNU gettext. */
-#undef HAVE_CATGETS
-
-/* Define as 1 if you have gettext and don't want to use GNU gettext. */
-#undef HAVE_GETTEXT
-
-/* Define as 1 if you have the stpcpy function. */
-#undef HAVE_STPCPY
-
-/* Define if your locale.h file contains LC_MESSAGES. */
-#undef HAVE_LC_MESSAGES
-
/* Define if building universal (internal helper macro) */
#undef AC_APPLE_UNIVERSAL_BUILD
@@ -58,6 +43,9 @@
/* Define to 1 if you have the `kill' function. */
#undef HAVE_KILL
+/* Define to 1 if you have the `m' library (-lm). */
+#undef HAVE_LIBM
+
/* Define to 1 if you have the `nsl' library (-lnsl). */
#undef HAVE_LIBNSL
@@ -70,6 +58,9 @@
/* Define to 1 if you have the <linux/mii.h> header file. */
#undef HAVE_LINUX_MII_H
+/* Define to 1 if you have the <linux/types.h> header file. */
+#undef HAVE_LINUX_TYPES_H
+
/* Define to 1 if you have the <memory.h> header file. */
#undef HAVE_MEMORY_H
diff --git a/sim/bfin/configure b/sim/bfin/configure
index a8c4639..fe1fc7c 100755
--- a/sim/bfin/configure
+++ b/sim/bfin/configure
@@ -2468,9 +2468,9 @@
# AC_PROG_CPP_WERROR
# Test for GNAT.
-# We require the gnatbind program, and a compiler driver that
-# understands Ada. We use the user's CC setting, already found,
-# and possibly add $1 to the command-line parameters.
+# We require the gnatbind & gnatmake programs, as well as a compiler driver
+# that understands Ada. We use the user's CC setting, already found, and
+# possibly add $1 to the command-line parameters.
#
# Sets the shell variable have_gnat to yes or no as appropriate, and
# substitutes GNATBIND and GNATMAKE.
@@ -5414,7 +5414,14 @@
fi
done
-for ac_header in sys/ioctl.h sys/mman.h net/if.h linux/if_tun.h linux/mii.h
+for ac_header in \
+ linux/if_tun.h \
+ linux/mii.h \
+ linux/types.h \
+ net/if.h \
+ sys/ioctl.h \
+ sys/mman.h \
+
do :
as_ac_Header=`$as_echo "ac_cv_header_$ac_header" | $as_tr_sh`
ac_fn_c_check_header_mongrel "$LINENO" "$ac_header" "$as_ac_Header" "$ac_includes_default"
diff --git a/sim/bfin/configure.ac b/sim/bfin/configure.ac
index 1917c01..cda3ac9 100644
--- a/sim/bfin/configure.ac
+++ b/sim/bfin/configure.ac
@@ -45,7 +45,14 @@
)
AC_CHECK_FUNCS([getuid getgid geteuid getegid setuid setgid mmap munmap kill pread])
-AC_CHECK_HEADERS([sys/ioctl.h sys/mman.h net/if.h linux/if_tun.h linux/mii.h])
+AC_CHECK_HEADERS([ \
+ linux/if_tun.h \
+ linux/mii.h \
+ linux/types.h \
+ net/if.h \
+ sys/ioctl.h \
+ sys/mman.h \
+])
BFIN_SIM_EXTRA_OBJS=
diff --git a/sim/bfin/dv-eth_phy.c b/sim/bfin/dv-eth_phy.c
index f7d7172..e42b213 100644
--- a/sim/bfin/dv-eth_phy.c
+++ b/sim/bfin/dv-eth_phy.c
@@ -23,11 +23,10 @@
#include "sim-main.h"
#include "devices.h"
-#ifdef HAVE_LINUX_MII_H
+#if defined (HAVE_LINUX_MII_H) && defined (HAVE_LINUX_TYPES_H)
/* Workaround old/broken linux headers. */
-#define _LINUX_TYPES_H
-#define __u16 unsigned short
+#include <linux/types.h>
#include <linux/mii.h>
#define REG_PHY_SIZE 0x20
