blob: 7001ccbee164474d425a072ece61b8f2de4d7ad5 [file] [log] [blame]
/* Output Dwarf2 format symbol table information from GCC.
Copyright (C) 1992, 1993, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002,
2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
Free Software Foundation, Inc.
Contributed by Gary Funck (gary@intrepid.com).
Derived from DWARF 1 implementation of Ron Guilmette (rfg@monkeys.com).
Extensively modified by Jason Merrill (jason@cygnus.com).
This file is part of GCC.
GCC 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, or (at your option) any later
version.
GCC 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 GCC; see the file COPYING3. If not see
<http://www.gnu.org/licenses/>. */
/* TODO: Emit .debug_line header even when there are no functions, since
the file numbers are used by .debug_info. Alternately, leave
out locations for types and decls.
Avoid talking about ctors and op= for PODs.
Factor out common prologue sequences into multiple CIEs. */
/* The first part of this file deals with the DWARF 2 frame unwind
information, which is also used by the GCC efficient exception handling
mechanism. The second part, controlled only by an #ifdef
DWARF2_DEBUGGING_INFO, deals with the other DWARF 2 debugging
information. */
/* DWARF2 Abbreviation Glossary:
CFA = Canonical Frame Address
a fixed address on the stack which identifies a call frame.
We define it to be the value of SP just before the call insn.
The CFA register and offset, which may change during the course
of the function, are used to calculate its value at runtime.
CFI = Call Frame Instruction
an instruction for the DWARF2 abstract machine
CIE = Common Information Entry
information describing information common to one or more FDEs
DIE = Debugging Information Entry
FDE = Frame Description Entry
information describing the stack call frame, in particular,
how to restore registers
DW_CFA_... = DWARF2 CFA call frame instruction
DW_TAG_... = DWARF2 DIE tag */
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "tree.h"
#include "version.h"
#include "flags.h"
#include "real.h"
#include "rtl.h"
#include "hard-reg-set.h"
#include "regs.h"
#include "insn-config.h"
#include "reload.h"
#include "function.h"
#include "output.h"
#include "expr.h"
#include "libfuncs.h"
#include "except.h"
#include "dwarf2.h"
#include "dwarf2out.h"
#include "dwarf2asm.h"
#include "toplev.h"
#include "varray.h"
#include "ggc.h"
#include "md5.h"
#include "tm_p.h"
#include "diagnostic.h"
#include "debug.h"
#include "target.h"
#include "langhooks.h"
#include "hashtab.h"
#include "cgraph.h"
#include "input.h"
#ifdef DWARF2_DEBUGGING_INFO
static void dwarf2out_source_line (unsigned int, const char *);
#endif
#ifndef DWARF2_FRAME_INFO
# ifdef DWARF2_DEBUGGING_INFO
# define DWARF2_FRAME_INFO \
(write_symbols == DWARF2_DEBUG || write_symbols == VMS_AND_DWARF2_DEBUG)
# else
# define DWARF2_FRAME_INFO 0
# endif
#endif
/* Map register numbers held in the call frame info that gcc has
collected using DWARF_FRAME_REGNUM to those that should be output in
.debug_frame and .eh_frame. */
#ifndef DWARF2_FRAME_REG_OUT
#define DWARF2_FRAME_REG_OUT(REGNO, FOR_EH) (REGNO)
#endif
/* Save the result of dwarf2out_do_frame across PCH. */
static GTY(()) bool saved_do_cfi_asm = 0;
/* Decide whether we want to emit frame unwind information for the current
translation unit. */
int
dwarf2out_do_frame (void)
{
/* We want to emit correct CFA location expressions or lists, so we
have to return true if we're going to output debug info, even if
we're not going to output frame or unwind info. */
return (write_symbols == DWARF2_DEBUG
|| write_symbols == VMS_AND_DWARF2_DEBUG
|| DWARF2_FRAME_INFO || saved_do_cfi_asm
#ifdef DWARF2_UNWIND_INFO
|| (DWARF2_UNWIND_INFO
&& (flag_unwind_tables
|| (flag_exceptions && ! USING_SJLJ_EXCEPTIONS)))
#endif
);
}
/* Decide whether to emit frame unwind via assembler directives. */
int
dwarf2out_do_cfi_asm (void)
{
int enc;
#ifdef MIPS_DEBUGGING_INFO
return false;
#endif
if (!flag_dwarf2_cfi_asm || !dwarf2out_do_frame ())
return false;
if (saved_do_cfi_asm)
return true;
if (!HAVE_GAS_CFI_SECTIONS_DIRECTIVE)
{
#ifdef TARGET_UNWIND_INFO
return false;
#else
if (USING_SJLJ_EXCEPTIONS || (!flag_unwind_tables && !flag_exceptions))
return false;
#endif
}
if (!eh_personality_libfunc)
return true;
if (!HAVE_GAS_CFI_PERSONALITY_DIRECTIVE)
return false;
/* Make sure the personality encoding is one the assembler can support.
In particular, aligned addresses can't be handled. */
enc = ASM_PREFERRED_EH_DATA_FORMAT (/*code=*/2,/*global=*/1);
if ((enc & 0x70) != 0 && (enc & 0x70) != DW_EH_PE_pcrel)
return false;
enc = ASM_PREFERRED_EH_DATA_FORMAT (/*code=*/0,/*global=*/0);
if ((enc & 0x70) != 0 && (enc & 0x70) != DW_EH_PE_pcrel)
return false;
saved_do_cfi_asm = true;
return true;
}
/* The size of the target's pointer type. */
#ifndef PTR_SIZE
#define PTR_SIZE (POINTER_SIZE / BITS_PER_UNIT)
#endif
/* Array of RTXes referenced by the debugging information, which therefore
must be kept around forever. */
static GTY(()) VEC(rtx,gc) *used_rtx_array;
/* A pointer to the base of a list of incomplete types which might be
completed at some later time. incomplete_types_list needs to be a
VEC(tree,gc) because we want to tell the garbage collector about
it. */
static GTY(()) VEC(tree,gc) *incomplete_types;
/* A pointer to the base of a table of references to declaration
scopes. This table is a display which tracks the nesting
of declaration scopes at the current scope and containing
scopes. This table is used to find the proper place to
define type declaration DIE's. */
static GTY(()) VEC(tree,gc) *decl_scope_table;
/* Pointers to various DWARF2 sections. */
static GTY(()) section *debug_info_section;
static GTY(()) section *debug_abbrev_section;
static GTY(()) section *debug_aranges_section;
static GTY(()) section *debug_macinfo_section;
static GTY(()) section *debug_line_section;
static GTY(()) section *debug_loc_section;
static GTY(()) section *debug_pubnames_section;
static GTY(()) section *debug_pubtypes_section;
static GTY(()) section *debug_str_section;
static GTY(()) section *debug_ranges_section;
static GTY(()) section *debug_frame_section;
/* How to start an assembler comment. */
#ifndef ASM_COMMENT_START
#define ASM_COMMENT_START ";#"
#endif
typedef struct dw_cfi_struct *dw_cfi_ref;
typedef struct dw_fde_struct *dw_fde_ref;
typedef union dw_cfi_oprnd_struct *dw_cfi_oprnd_ref;
/* Call frames are described using a sequence of Call Frame
Information instructions. The register number, offset
and address fields are provided as possible operands;
their use is selected by the opcode field. */
enum dw_cfi_oprnd_type {
dw_cfi_oprnd_unused,
dw_cfi_oprnd_reg_num,
dw_cfi_oprnd_offset,
dw_cfi_oprnd_addr,
dw_cfi_oprnd_loc
};
typedef union dw_cfi_oprnd_struct GTY(())
{
unsigned int GTY ((tag ("dw_cfi_oprnd_reg_num"))) dw_cfi_reg_num;
HOST_WIDE_INT GTY ((tag ("dw_cfi_oprnd_offset"))) dw_cfi_offset;
const char * GTY ((tag ("dw_cfi_oprnd_addr"))) dw_cfi_addr;
struct dw_loc_descr_struct * GTY ((tag ("dw_cfi_oprnd_loc"))) dw_cfi_loc;
}
dw_cfi_oprnd;
typedef struct dw_cfi_struct GTY(())
{
dw_cfi_ref dw_cfi_next;
enum dwarf_call_frame_info dw_cfi_opc;
dw_cfi_oprnd GTY ((desc ("dw_cfi_oprnd1_desc (%1.dw_cfi_opc)")))
dw_cfi_oprnd1;
dw_cfi_oprnd GTY ((desc ("dw_cfi_oprnd2_desc (%1.dw_cfi_opc)")))
dw_cfi_oprnd2;
}
dw_cfi_node;
/* This is how we define the location of the CFA. We use to handle it
as REG + OFFSET all the time, but now it can be more complex.
It can now be either REG + CFA_OFFSET or *(REG + BASE_OFFSET) + CFA_OFFSET.
Instead of passing around REG and OFFSET, we pass a copy
of this structure. */
typedef struct cfa_loc GTY(())
{
HOST_WIDE_INT offset;
HOST_WIDE_INT base_offset;
unsigned int reg;
int indirect; /* 1 if CFA is accessed via a dereference. */
} dw_cfa_location;
/* All call frame descriptions (FDE's) in the GCC generated DWARF
refer to a single Common Information Entry (CIE), defined at
the beginning of the .debug_frame section. This use of a single
CIE obviates the need to keep track of multiple CIE's
in the DWARF generation routines below. */
typedef struct dw_fde_struct GTY(())
{
tree decl;
const char *dw_fde_begin;
const char *dw_fde_current_label;
const char *dw_fde_end;
const char *dw_fde_hot_section_label;
const char *dw_fde_hot_section_end_label;
const char *dw_fde_unlikely_section_label;
const char *dw_fde_unlikely_section_end_label;
bool dw_fde_switched_sections;
dw_cfi_ref dw_fde_cfi;
unsigned funcdef_number;
HOST_WIDE_INT stack_realignment;
/* Dynamic realign argument pointer register. */
unsigned int drap_reg;
/* Virtual dynamic realign argument pointer register. */
unsigned int vdrap_reg;
unsigned all_throwers_are_sibcalls : 1;
unsigned nothrow : 1;
unsigned uses_eh_lsda : 1;
/* Whether we did stack realign in this call frame. */
unsigned stack_realign : 1;
/* Whether dynamic realign argument pointer register has been saved. */
unsigned drap_reg_saved: 1;
}
dw_fde_node;
/* Maximum size (in bytes) of an artificially generated label. */
#define MAX_ARTIFICIAL_LABEL_BYTES 30
/* The size of addresses as they appear in the Dwarf 2 data.
Some architectures use word addresses to refer to code locations,
but Dwarf 2 info always uses byte addresses. On such machines,
Dwarf 2 addresses need to be larger than the architecture's
pointers. */
#ifndef DWARF2_ADDR_SIZE
#define DWARF2_ADDR_SIZE (POINTER_SIZE / BITS_PER_UNIT)
#endif
/* The size in bytes of a DWARF field indicating an offset or length
relative to a debug info section, specified to be 4 bytes in the
DWARF-2 specification. The SGI/MIPS ABI defines it to be the same
as PTR_SIZE. */
#ifndef DWARF_OFFSET_SIZE
#define DWARF_OFFSET_SIZE 4
#endif
/* According to the (draft) DWARF 3 specification, the initial length
should either be 4 or 12 bytes. When it's 12 bytes, the first 4
bytes are 0xffffffff, followed by the length stored in the next 8
bytes.
However, the SGI/MIPS ABI uses an initial length which is equal to
DWARF_OFFSET_SIZE. It is defined (elsewhere) accordingly. */
#ifndef DWARF_INITIAL_LENGTH_SIZE
#define DWARF_INITIAL_LENGTH_SIZE (DWARF_OFFSET_SIZE == 4 ? 4 : 12)
#endif
#define DWARF_VERSION 2
/* Round SIZE up to the nearest BOUNDARY. */
#define DWARF_ROUND(SIZE,BOUNDARY) \
((((SIZE) + (BOUNDARY) - 1) / (BOUNDARY)) * (BOUNDARY))
/* Offsets recorded in opcodes are a multiple of this alignment factor. */
#ifndef DWARF_CIE_DATA_ALIGNMENT
#ifdef STACK_GROWS_DOWNWARD
#define DWARF_CIE_DATA_ALIGNMENT (-((int) UNITS_PER_WORD))
#else
#define DWARF_CIE_DATA_ALIGNMENT ((int) UNITS_PER_WORD)
#endif
#endif
/* CIE identifier. */
#if HOST_BITS_PER_WIDE_INT >= 64
#define DWARF_CIE_ID \
(unsigned HOST_WIDE_INT) (DWARF_OFFSET_SIZE == 4 ? DW_CIE_ID : DW64_CIE_ID)
#else
#define DWARF_CIE_ID DW_CIE_ID
#endif
/* A pointer to the base of a table that contains frame description
information for each routine. */
static GTY((length ("fde_table_allocated"))) dw_fde_ref fde_table;
/* Number of elements currently allocated for fde_table. */
static GTY(()) unsigned fde_table_allocated;
/* Number of elements in fde_table currently in use. */
static GTY(()) unsigned fde_table_in_use;
/* Size (in elements) of increments by which we may expand the
fde_table. */
#define FDE_TABLE_INCREMENT 256
/* Get the current fde_table entry we should use. */
static inline dw_fde_ref
current_fde (void)
{
return fde_table_in_use ? &fde_table[fde_table_in_use - 1] : NULL;
}
/* A list of call frame insns for the CIE. */
static GTY(()) dw_cfi_ref cie_cfi_head;
#if defined (DWARF2_DEBUGGING_INFO) || defined (DWARF2_UNWIND_INFO)
/* Some DWARF extensions (e.g., MIPS/SGI) implement a subprogram
attribute that accelerates the lookup of the FDE associated
with the subprogram. This variable holds the table index of the FDE
associated with the current function (body) definition. */
static unsigned current_funcdef_fde;
#endif
struct indirect_string_node GTY(())
{
const char *str;
unsigned int refcount;
unsigned int form;
char *label;
};
static GTY ((param_is (struct indirect_string_node))) htab_t debug_str_hash;
static GTY(()) int dw2_string_counter;
static GTY(()) unsigned long dwarf2out_cfi_label_num;
/* True if the compilation unit places functions in more than one section. */
static GTY(()) bool have_multiple_function_sections = false;
/* Whether the default text and cold text sections have been used at all. */
static GTY(()) bool text_section_used = false;
static GTY(()) bool cold_text_section_used = false;
/* The default cold text section. */
static GTY(()) section *cold_text_section;
#if defined (DWARF2_DEBUGGING_INFO) || defined (DWARF2_UNWIND_INFO)
/* Forward declarations for functions defined in this file. */
static char *stripattributes (const char *);
static const char *dwarf_cfi_name (unsigned);
static dw_cfi_ref new_cfi (void);
static void add_cfi (dw_cfi_ref *, dw_cfi_ref);
static void add_fde_cfi (const char *, dw_cfi_ref);
static void lookup_cfa_1 (dw_cfi_ref, dw_cfa_location *);
static void lookup_cfa (dw_cfa_location *);
static void reg_save (const char *, unsigned, unsigned, HOST_WIDE_INT);
#ifdef DWARF2_UNWIND_INFO
static void initial_return_save (rtx);
#endif
static HOST_WIDE_INT stack_adjust_offset (const_rtx, HOST_WIDE_INT,
HOST_WIDE_INT);
static void output_cfi (dw_cfi_ref, dw_fde_ref, int);
static void output_cfi_directive (dw_cfi_ref);
static void output_call_frame_info (int);
static void dwarf2out_note_section_used (void);
static void dwarf2out_stack_adjust (rtx, bool);
static void dwarf2out_args_size_adjust (HOST_WIDE_INT, const char *);
static void flush_queued_reg_saves (void);
static bool clobbers_queued_reg_save (const_rtx);
static void dwarf2out_frame_debug_expr (rtx, const char *);
/* Support for complex CFA locations. */
static void output_cfa_loc (dw_cfi_ref);
static void output_cfa_loc_raw (dw_cfi_ref);
static void get_cfa_from_loc_descr (dw_cfa_location *,
struct dw_loc_descr_struct *);
static struct dw_loc_descr_struct *build_cfa_loc
(dw_cfa_location *, HOST_WIDE_INT);
static struct dw_loc_descr_struct *build_cfa_aligned_loc
(HOST_WIDE_INT, HOST_WIDE_INT);
static void def_cfa_1 (const char *, dw_cfa_location *);
/* How to start an assembler comment. */
#ifndef ASM_COMMENT_START
#define ASM_COMMENT_START ";#"
#endif
/* Data and reference forms for relocatable data. */
#define DW_FORM_data (DWARF_OFFSET_SIZE == 8 ? DW_FORM_data8 : DW_FORM_data4)
#define DW_FORM_ref (DWARF_OFFSET_SIZE == 8 ? DW_FORM_ref8 : DW_FORM_ref4)
#ifndef DEBUG_FRAME_SECTION
#define DEBUG_FRAME_SECTION ".debug_frame"
#endif
#ifndef FUNC_BEGIN_LABEL
#define FUNC_BEGIN_LABEL "LFB"
#endif
#ifndef FUNC_END_LABEL
#define FUNC_END_LABEL "LFE"
#endif
#ifndef FRAME_BEGIN_LABEL
#define FRAME_BEGIN_LABEL "Lframe"
#endif
#define CIE_AFTER_SIZE_LABEL "LSCIE"
#define CIE_END_LABEL "LECIE"
#define FDE_LABEL "LSFDE"
#define FDE_AFTER_SIZE_LABEL "LASFDE"
#define FDE_END_LABEL "LEFDE"
#define LINE_NUMBER_BEGIN_LABEL "LSLT"
#define LINE_NUMBER_END_LABEL "LELT"
#define LN_PROLOG_AS_LABEL "LASLTP"
#define LN_PROLOG_END_LABEL "LELTP"
#define DIE_LABEL_PREFIX "DW"
/* The DWARF 2 CFA column which tracks the return address. Normally this
is the column for PC, or the first column after all of the hard
registers. */
#ifndef DWARF_FRAME_RETURN_COLUMN
#ifdef PC_REGNUM
#define DWARF_FRAME_RETURN_COLUMN DWARF_FRAME_REGNUM (PC_REGNUM)
#else
#define DWARF_FRAME_RETURN_COLUMN DWARF_FRAME_REGISTERS
#endif
#endif
/* The mapping from gcc register number to DWARF 2 CFA column number. By
default, we just provide columns for all registers. */
#ifndef DWARF_FRAME_REGNUM
#define DWARF_FRAME_REGNUM(REG) DBX_REGISTER_NUMBER (REG)
#endif
/* Hook used by __throw. */
rtx
expand_builtin_dwarf_sp_column (void)
{
unsigned int dwarf_regnum = DWARF_FRAME_REGNUM (STACK_POINTER_REGNUM);
return GEN_INT (DWARF2_FRAME_REG_OUT (dwarf_regnum, 1));
}
/* Return a pointer to a copy of the section string name S with all
attributes stripped off, and an asterisk prepended (for assemble_name). */
static inline char *
stripattributes (const char *s)
{
char *stripped = XNEWVEC (char, strlen (s) + 2);
char *p = stripped;
*p++ = '*';
while (*s && *s != ',')
*p++ = *s++;
*p = '\0';
return stripped;
}
/* MEM is a memory reference for the register size table, each element of
which has mode MODE. Initialize column C as a return address column. */
static void
init_return_column_size (enum machine_mode mode, rtx mem, unsigned int c)
{
HOST_WIDE_INT offset = c * GET_MODE_SIZE (mode);
HOST_WIDE_INT size = GET_MODE_SIZE (Pmode);
emit_move_insn (adjust_address (mem, mode, offset), GEN_INT (size));
}
/* Generate code to initialize the register size table. */
void
expand_builtin_init_dwarf_reg_sizes (tree address)
{
unsigned int i;
enum machine_mode mode = TYPE_MODE (char_type_node);
rtx addr = expand_normal (address);
rtx mem = gen_rtx_MEM (BLKmode, addr);
bool wrote_return_column = false;
for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
{
int rnum = DWARF2_FRAME_REG_OUT (DWARF_FRAME_REGNUM (i), 1);
if (rnum < DWARF_FRAME_REGISTERS)
{
HOST_WIDE_INT offset = rnum * GET_MODE_SIZE (mode);
enum machine_mode save_mode = reg_raw_mode[i];
HOST_WIDE_INT size;
if (HARD_REGNO_CALL_PART_CLOBBERED (i, save_mode))
save_mode = choose_hard_reg_mode (i, 1, true);
if (DWARF_FRAME_REGNUM (i) == DWARF_FRAME_RETURN_COLUMN)
{
if (save_mode == VOIDmode)
continue;
wrote_return_column = true;
}
size = GET_MODE_SIZE (save_mode);
if (offset < 0)
continue;
emit_move_insn (adjust_address (mem, mode, offset),
gen_int_mode (size, mode));
}
}
if (!wrote_return_column)
init_return_column_size (mode, mem, DWARF_FRAME_RETURN_COLUMN);
#ifdef DWARF_ALT_FRAME_RETURN_COLUMN
init_return_column_size (mode, mem, DWARF_ALT_FRAME_RETURN_COLUMN);
#endif
targetm.init_dwarf_reg_sizes_extra (address);
}
/* Convert a DWARF call frame info. operation to its string name */
static const char *
dwarf_cfi_name (unsigned int cfi_opc)
{
switch (cfi_opc)
{
case DW_CFA_advance_loc:
return "DW_CFA_advance_loc";
case DW_CFA_offset:
return "DW_CFA_offset";
case DW_CFA_restore:
return "DW_CFA_restore";
case DW_CFA_nop:
return "DW_CFA_nop";
case DW_CFA_set_loc:
return "DW_CFA_set_loc";
case DW_CFA_advance_loc1:
return "DW_CFA_advance_loc1";
case DW_CFA_advance_loc2:
return "DW_CFA_advance_loc2";
case DW_CFA_advance_loc4:
return "DW_CFA_advance_loc4";
case DW_CFA_offset_extended:
return "DW_CFA_offset_extended";
case DW_CFA_restore_extended:
return "DW_CFA_restore_extended";
case DW_CFA_undefined:
return "DW_CFA_undefined";
case DW_CFA_same_value:
return "DW_CFA_same_value";
case DW_CFA_register:
return "DW_CFA_register";
case DW_CFA_remember_state:
return "DW_CFA_remember_state";
case DW_CFA_restore_state:
return "DW_CFA_restore_state";
case DW_CFA_def_cfa:
return "DW_CFA_def_cfa";
case DW_CFA_def_cfa_register:
return "DW_CFA_def_cfa_register";
case DW_CFA_def_cfa_offset:
return "DW_CFA_def_cfa_offset";
/* DWARF 3 */
case DW_CFA_def_cfa_expression:
return "DW_CFA_def_cfa_expression";
case DW_CFA_expression:
return "DW_CFA_expression";
case DW_CFA_offset_extended_sf:
return "DW_CFA_offset_extended_sf";
case DW_CFA_def_cfa_sf:
return "DW_CFA_def_cfa_sf";
case DW_CFA_def_cfa_offset_sf:
return "DW_CFA_def_cfa_offset_sf";
/* SGI/MIPS specific */
case DW_CFA_MIPS_advance_loc8:
return "DW_CFA_MIPS_advance_loc8";
/* GNU extensions */
case DW_CFA_GNU_window_save:
return "DW_CFA_GNU_window_save";
case DW_CFA_GNU_args_size:
return "DW_CFA_GNU_args_size";
case DW_CFA_GNU_negative_offset_extended:
return "DW_CFA_GNU_negative_offset_extended";
default:
return "DW_CFA_<unknown>";
}
}
/* Return a pointer to a newly allocated Call Frame Instruction. */
static inline dw_cfi_ref
new_cfi (void)
{
dw_cfi_ref cfi = GGC_NEW (dw_cfi_node);
cfi->dw_cfi_next = NULL;
cfi->dw_cfi_oprnd1.dw_cfi_reg_num = 0;
cfi->dw_cfi_oprnd2.dw_cfi_reg_num = 0;
return cfi;
}
/* Add a Call Frame Instruction to list of instructions. */
static inline void
add_cfi (dw_cfi_ref *list_head, dw_cfi_ref cfi)
{
dw_cfi_ref *p;
dw_fde_ref fde = current_fde ();
/* When DRAP is used, CFA is defined with an expression. Redefine
CFA may lead to a different CFA value. */
if (fde && fde->drap_reg != INVALID_REGNUM)
switch (cfi->dw_cfi_opc)
{
case DW_CFA_def_cfa_register:
case DW_CFA_def_cfa_offset:
case DW_CFA_def_cfa_offset_sf:
case DW_CFA_def_cfa:
case DW_CFA_def_cfa_sf:
gcc_unreachable ();
default:
break;
}
/* Find the end of the chain. */
for (p = list_head; (*p) != NULL; p = &(*p)->dw_cfi_next)
;
*p = cfi;
}
/* Generate a new label for the CFI info to refer to. FORCE is true
if a label needs to be output even when using .cfi_* directives. */
char *
dwarf2out_cfi_label (bool force)
{
static char label[20];
if (!force && dwarf2out_do_cfi_asm ())
{
/* In this case, we will be emitting the asm directive instead of
the label, so just return a placeholder to keep the rest of the
interfaces happy. */
strcpy (label, "<do not output>");
}
else
{
ASM_GENERATE_INTERNAL_LABEL (label, "LCFI", dwarf2out_cfi_label_num++);
ASM_OUTPUT_LABEL (asm_out_file, label);
}
return label;
}
/* Add CFI to the current fde at the PC value indicated by LABEL if specified,
or to the CIE if LABEL is NULL. */
static void
add_fde_cfi (const char *label, dw_cfi_ref cfi)
{
dw_cfi_ref *list_head = &cie_cfi_head;
if (dwarf2out_do_cfi_asm ())
{
if (label)
{
dw_fde_ref fde = current_fde ();
gcc_assert (fde != NULL);
/* We still have to add the cfi to the list so that
lookup_cfa works later on. When -g2 and above we
even need to force emitting of CFI labels and
add to list a DW_CFA_set_loc for convert_cfa_to_fb_loc_list
purposes. */
switch (cfi->dw_cfi_opc)
{
case DW_CFA_def_cfa_offset:
case DW_CFA_def_cfa_offset_sf:
case DW_CFA_def_cfa_register:
case DW_CFA_def_cfa:
case DW_CFA_def_cfa_sf:
case DW_CFA_def_cfa_expression:
case DW_CFA_restore_state:
if (write_symbols != DWARF2_DEBUG
&& write_symbols != VMS_AND_DWARF2_DEBUG)
break;
if (debug_info_level <= DINFO_LEVEL_TERSE)
break;
if (*label == 0 || strcmp (label, "<do not output>") == 0)
label = dwarf2out_cfi_label (true);
if (fde->dw_fde_current_label == NULL
|| strcmp (label, fde->dw_fde_current_label) != 0)
{
dw_cfi_ref xcfi;
label = xstrdup (label);
/* Set the location counter to the new label. */
xcfi = new_cfi ();
/* It doesn't metter whether DW_CFA_set_loc
or DW_CFA_advance_loc4 is added here, those aren't
emitted into assembly, only looked up by
convert_cfa_to_fb_loc_list. */
xcfi->dw_cfi_opc = DW_CFA_set_loc;
xcfi->dw_cfi_oprnd1.dw_cfi_addr = label;
add_cfi (&fde->dw_fde_cfi, xcfi);
fde->dw_fde_current_label = label;
}
break;
default:
break;
}
output_cfi_directive (cfi);
list_head = &fde->dw_fde_cfi;
}
/* ??? If this is a CFI for the CIE, we don't emit. This
assumes that the standard CIE contents that the assembler
uses matches the standard CIE contents that the compiler
uses. This is probably a bad assumption. I'm not quite
sure how to address this for now. */
}
else if (label)
{
dw_fde_ref fde = current_fde ();
gcc_assert (fde != NULL);
if (*label == 0)
label = dwarf2out_cfi_label (false);
if (fde->dw_fde_current_label == NULL
|| strcmp (label, fde->dw_fde_current_label) != 0)
{
dw_cfi_ref xcfi;
label = xstrdup (label);
/* Set the location counter to the new label. */
xcfi = new_cfi ();
/* If we have a current label, advance from there, otherwise
set the location directly using set_loc. */
xcfi->dw_cfi_opc = fde->dw_fde_current_label
? DW_CFA_advance_loc4
: DW_CFA_set_loc;
xcfi->dw_cfi_oprnd1.dw_cfi_addr = label;
add_cfi (&fde->dw_fde_cfi, xcfi);
fde->dw_fde_current_label = label;
}
list_head = &fde->dw_fde_cfi;
}
add_cfi (list_head, cfi);
}
/* Subroutine of lookup_cfa. */
static void
lookup_cfa_1 (dw_cfi_ref cfi, dw_cfa_location *loc)
{
switch (cfi->dw_cfi_opc)
{
case DW_CFA_def_cfa_offset:
case DW_CFA_def_cfa_offset_sf:
loc->offset = cfi->dw_cfi_oprnd1.dw_cfi_offset;
break;
case DW_CFA_def_cfa_register:
loc->reg = cfi->dw_cfi_oprnd1.dw_cfi_reg_num;
break;
case DW_CFA_def_cfa:
case DW_CFA_def_cfa_sf:
loc->reg = cfi->dw_cfi_oprnd1.dw_cfi_reg_num;
loc->offset = cfi->dw_cfi_oprnd2.dw_cfi_offset;
break;
case DW_CFA_def_cfa_expression:
get_cfa_from_loc_descr (loc, cfi->dw_cfi_oprnd1.dw_cfi_loc);
break;
default:
break;
}
}
/* Find the previous value for the CFA. */
static void
lookup_cfa (dw_cfa_location *loc)
{
dw_cfi_ref cfi;
dw_fde_ref fde;
loc->reg = INVALID_REGNUM;
loc->offset = 0;
loc->indirect = 0;
loc->base_offset = 0;
for (cfi = cie_cfi_head; cfi; cfi = cfi->dw_cfi_next)
lookup_cfa_1 (cfi, loc);
fde = current_fde ();
if (fde)
for (cfi = fde->dw_fde_cfi; cfi; cfi = cfi->dw_cfi_next)
lookup_cfa_1 (cfi, loc);
}
/* The current rule for calculating the DWARF2 canonical frame address. */
static dw_cfa_location cfa;
/* The register used for saving registers to the stack, and its offset
from the CFA. */
static dw_cfa_location cfa_store;
/* The running total of the size of arguments pushed onto the stack. */
static HOST_WIDE_INT args_size;
/* The last args_size we actually output. */
static HOST_WIDE_INT old_args_size;
/* Entry point to update the canonical frame address (CFA).
LABEL is passed to add_fde_cfi. The value of CFA is now to be
calculated from REG+OFFSET. */
void
dwarf2out_def_cfa (const char *label, unsigned int reg, HOST_WIDE_INT offset)
{
dw_cfa_location loc;
loc.indirect = 0;
loc.base_offset = 0;
loc.reg = reg;
loc.offset = offset;
def_cfa_1 (label, &loc);
}
/* Determine if two dw_cfa_location structures define the same data. */
static bool
cfa_equal_p (const dw_cfa_location *loc1, const dw_cfa_location *loc2)
{
return (loc1->reg == loc2->reg
&& loc1->offset == loc2->offset
&& loc1->indirect == loc2->indirect
&& (loc1->indirect == 0
|| loc1->base_offset == loc2->base_offset));
}
/* This routine does the actual work. The CFA is now calculated from
the dw_cfa_location structure. */
static void
def_cfa_1 (const char *label, dw_cfa_location *loc_p)
{
dw_cfi_ref cfi;
dw_cfa_location old_cfa, loc;
cfa = *loc_p;
loc = *loc_p;
if (cfa_store.reg == loc.reg && loc.indirect == 0)
cfa_store.offset = loc.offset;
loc.reg = DWARF_FRAME_REGNUM (loc.reg);
lookup_cfa (&old_cfa);
/* If nothing changed, no need to issue any call frame instructions. */
if (cfa_equal_p (&loc, &old_cfa))
return;
cfi = new_cfi ();
if (loc.reg == old_cfa.reg && !loc.indirect)
{
/* Construct a "DW_CFA_def_cfa_offset <offset>" instruction, indicating
the CFA register did not change but the offset did. The data
factoring for DW_CFA_def_cfa_offset_sf happens in output_cfi, or
in the assembler via the .cfi_def_cfa_offset directive. */
if (loc.offset < 0)
cfi->dw_cfi_opc = DW_CFA_def_cfa_offset_sf;
else
cfi->dw_cfi_opc = DW_CFA_def_cfa_offset;
cfi->dw_cfi_oprnd1.dw_cfi_offset = loc.offset;
}
#ifndef MIPS_DEBUGGING_INFO /* SGI dbx thinks this means no offset. */
else if (loc.offset == old_cfa.offset
&& old_cfa.reg != INVALID_REGNUM
&& !loc.indirect)
{
/* Construct a "DW_CFA_def_cfa_register <register>" instruction,
indicating the CFA register has changed to <register> but the
offset has not changed. */
cfi->dw_cfi_opc = DW_CFA_def_cfa_register;
cfi->dw_cfi_oprnd1.dw_cfi_reg_num = loc.reg;
}
#endif
else if (loc.indirect == 0)
{
/* Construct a "DW_CFA_def_cfa <register> <offset>" instruction,
indicating the CFA register has changed to <register> with
the specified offset. The data factoring for DW_CFA_def_cfa_sf
happens in output_cfi, or in the assembler via the .cfi_def_cfa
directive. */
if (loc.offset < 0)
cfi->dw_cfi_opc = DW_CFA_def_cfa_sf;
else
cfi->dw_cfi_opc = DW_CFA_def_cfa;
cfi->dw_cfi_oprnd1.dw_cfi_reg_num = loc.reg;
cfi->dw_cfi_oprnd2.dw_cfi_offset = loc.offset;
}
else
{
/* Construct a DW_CFA_def_cfa_expression instruction to
calculate the CFA using a full location expression since no
register-offset pair is available. */
struct dw_loc_descr_struct *loc_list;
cfi->dw_cfi_opc = DW_CFA_def_cfa_expression;
loc_list = build_cfa_loc (&loc, 0);
cfi->dw_cfi_oprnd1.dw_cfi_loc = loc_list;
}
add_fde_cfi (label, cfi);
}
/* Add the CFI for saving a register. REG is the CFA column number.
LABEL is passed to add_fde_cfi.
If SREG is -1, the register is saved at OFFSET from the CFA;
otherwise it is saved in SREG. */
static void
reg_save (const char *label, unsigned int reg, unsigned int sreg, HOST_WIDE_INT offset)
{
dw_cfi_ref cfi = new_cfi ();
dw_fde_ref fde = current_fde ();
cfi->dw_cfi_oprnd1.dw_cfi_reg_num = reg;
/* When stack is aligned, store REG using DW_CFA_expression with
FP. */
if (fde
&& fde->stack_realign
&& sreg == INVALID_REGNUM)
{
cfi->dw_cfi_opc = DW_CFA_expression;
cfi->dw_cfi_oprnd2.dw_cfi_reg_num = reg;
cfi->dw_cfi_oprnd1.dw_cfi_loc
= build_cfa_aligned_loc (offset, fde->stack_realignment);
}
else if (sreg == INVALID_REGNUM)
{
if (offset < 0)
cfi->dw_cfi_opc = DW_CFA_offset_extended_sf;
else if (reg & ~0x3f)
cfi->dw_cfi_opc = DW_CFA_offset_extended;
else
cfi->dw_cfi_opc = DW_CFA_offset;
cfi->dw_cfi_oprnd2.dw_cfi_offset = offset;
}
else if (sreg == reg)
cfi->dw_cfi_opc = DW_CFA_same_value;
else
{
cfi->dw_cfi_opc = DW_CFA_register;
cfi->dw_cfi_oprnd2.dw_cfi_reg_num = sreg;
}
add_fde_cfi (label, cfi);
}
/* Add the CFI for saving a register window. LABEL is passed to reg_save.
This CFI tells the unwinder that it needs to restore the window registers
from the previous frame's window save area.
??? Perhaps we should note in the CIE where windows are saved (instead of
assuming 0(cfa)) and what registers are in the window. */
void
dwarf2out_window_save (const char *label)
{
dw_cfi_ref cfi = new_cfi ();
cfi->dw_cfi_opc = DW_CFA_GNU_window_save;
add_fde_cfi (label, cfi);
}
/* Add a CFI to update the running total of the size of arguments
pushed onto the stack. */
void
dwarf2out_args_size (const char *label, HOST_WIDE_INT size)
{
dw_cfi_ref cfi;
if (size == old_args_size)
return;
old_args_size = size;
cfi = new_cfi ();
cfi->dw_cfi_opc = DW_CFA_GNU_args_size;
cfi->dw_cfi_oprnd1.dw_cfi_offset = size;
add_fde_cfi (label, cfi);
}
/* Entry point for saving a register to the stack. REG is the GCC register
number. LABEL and OFFSET are passed to reg_save. */
void
dwarf2out_reg_save (const char *label, unsigned int reg, HOST_WIDE_INT offset)
{
reg_save (label, DWARF_FRAME_REGNUM (reg), INVALID_REGNUM, offset);
}
/* Entry point for saving the return address in the stack.
LABEL and OFFSET are passed to reg_save. */
void
dwarf2out_return_save (const char *label, HOST_WIDE_INT offset)
{
reg_save (label, DWARF_FRAME_RETURN_COLUMN, INVALID_REGNUM, offset);
}
/* Entry point for saving the return address in a register.
LABEL and SREG are passed to reg_save. */
void
dwarf2out_return_reg (const char *label, unsigned int sreg)
{
reg_save (label, DWARF_FRAME_RETURN_COLUMN, DWARF_FRAME_REGNUM (sreg), 0);
}
#ifdef DWARF2_UNWIND_INFO
/* Record the initial position of the return address. RTL is
INCOMING_RETURN_ADDR_RTX. */
static void
initial_return_save (rtx rtl)
{
unsigned int reg = INVALID_REGNUM;
HOST_WIDE_INT offset = 0;
switch (GET_CODE (rtl))
{
case REG:
/* RA is in a register. */
reg = DWARF_FRAME_REGNUM (REGNO (rtl));
break;
case MEM:
/* RA is on the stack. */
rtl = XEXP (rtl, 0);
switch (GET_CODE (rtl))
{
case REG:
gcc_assert (REGNO (rtl) == STACK_POINTER_REGNUM);
offset = 0;
break;
case PLUS:
gcc_assert (REGNO (XEXP (rtl, 0)) == STACK_POINTER_REGNUM);
offset = INTVAL (XEXP (rtl, 1));
break;
case MINUS:
gcc_assert (REGNO (XEXP (rtl, 0)) == STACK_POINTER_REGNUM);
offset = -INTVAL (XEXP (rtl, 1));
break;
default:
gcc_unreachable ();
}
break;
case PLUS:
/* The return address is at some offset from any value we can
actually load. For instance, on the SPARC it is in %i7+8. Just
ignore the offset for now; it doesn't matter for unwinding frames. */
gcc_assert (GET_CODE (XEXP (rtl, 1)) == CONST_INT);
initial_return_save (XEXP (rtl, 0));
return;
default:
gcc_unreachable ();
}
if (reg != DWARF_FRAME_RETURN_COLUMN)
reg_save (NULL, DWARF_FRAME_RETURN_COLUMN, reg, offset - cfa.offset);
}
#endif
/* Given a SET, calculate the amount of stack adjustment it
contains. */
static HOST_WIDE_INT
stack_adjust_offset (const_rtx pattern, HOST_WIDE_INT cur_args_size,
HOST_WIDE_INT cur_offset)
{
const_rtx src = SET_SRC (pattern);
const_rtx dest = SET_DEST (pattern);
HOST_WIDE_INT offset = 0;
enum rtx_code code;
if (dest == stack_pointer_rtx)
{
code = GET_CODE (src);
/* Assume (set (reg sp) (reg whatever)) sets args_size
level to 0. */
if (code == REG && src != stack_pointer_rtx)
{
offset = -cur_args_size;
#ifndef STACK_GROWS_DOWNWARD
offset = -offset;
#endif
return offset - cur_offset;
}
if (! (code == PLUS || code == MINUS)
|| XEXP (src, 0) != stack_pointer_rtx
|| GET_CODE (XEXP (src, 1)) != CONST_INT)
return 0;
/* (set (reg sp) (plus (reg sp) (const_int))) */
offset = INTVAL (XEXP (src, 1));
if (code == PLUS)
offset = -offset;
return offset;
}
if (MEM_P (src) && !MEM_P (dest))
dest = src;
if (MEM_P (dest))
{
/* (set (mem (pre_dec (reg sp))) (foo)) */
src = XEXP (dest, 0);
code = GET_CODE (src);
switch (code)
{
case PRE_MODIFY:
case POST_MODIFY:
if (XEXP (src, 0) == stack_pointer_rtx)
{
rtx val = XEXP (XEXP (src, 1), 1);
/* We handle only adjustments by constant amount. */
gcc_assert (GET_CODE (XEXP (src, 1)) == PLUS
&& GET_CODE (val) == CONST_INT);
offset = -INTVAL (val);
break;
}
return 0;
case PRE_DEC:
case POST_DEC:
if (XEXP (src, 0) == stack_pointer_rtx)
{
offset = GET_MODE_SIZE (GET_MODE (dest));
break;
}
return 0;
case PRE_INC:
case POST_INC:
if (XEXP (src, 0) == stack_pointer_rtx)
{
offset = -GET_MODE_SIZE (GET_MODE (dest));
break;
}
return 0;
default:
return 0;
}
}
else
return 0;
return offset;
}
/* Precomputed args_size for CODE_LABELs and BARRIERs preceeding them,
indexed by INSN_UID. */
static HOST_WIDE_INT *barrier_args_size;
/* Helper function for compute_barrier_args_size. Handle one insn. */
static HOST_WIDE_INT
compute_barrier_args_size_1 (rtx insn, HOST_WIDE_INT cur_args_size,
VEC (rtx, heap) **next)
{
HOST_WIDE_INT offset = 0;
int i;
if (! RTX_FRAME_RELATED_P (insn))
{
if (prologue_epilogue_contains (insn)
|| sibcall_epilogue_contains (insn))
/* Nothing */;
else if (GET_CODE (PATTERN (insn)) == SET)
offset = stack_adjust_offset (PATTERN (insn), cur_args_size, 0);
else if (GET_CODE (PATTERN (insn)) == PARALLEL
|| GET_CODE (PATTERN (insn)) == SEQUENCE)
{
/* There may be stack adjustments inside compound insns. Search
for them. */
for (i = XVECLEN (PATTERN (insn), 0) - 1; i >= 0; i--)
if (GET_CODE (XVECEXP (PATTERN (insn), 0, i)) == SET)
offset += stack_adjust_offset (XVECEXP (PATTERN (insn), 0, i),
cur_args_size, offset);
}
}
else
{
rtx expr = find_reg_note (insn, REG_FRAME_RELATED_EXPR, NULL_RTX);
if (expr)
{
expr = XEXP (expr, 0);
if (GET_CODE (expr) == PARALLEL
|| GET_CODE (expr) == SEQUENCE)
for (i = 1; i < XVECLEN (expr, 0); i++)
{
rtx elem = XVECEXP (expr, 0, i);
if (GET_CODE (elem) == SET && !RTX_FRAME_RELATED_P (elem))
offset += stack_adjust_offset (elem, cur_args_size, offset);
}
}
}
#ifndef STACK_GROWS_DOWNWARD
offset = -offset;
#endif
cur_args_size += offset;
if (cur_args_size < 0)
cur_args_size = 0;
if (JUMP_P (insn))
{
rtx dest = JUMP_LABEL (insn);
if (dest)
{
if (barrier_args_size [INSN_UID (dest)] < 0)
{
barrier_args_size [INSN_UID (dest)] = cur_args_size;
VEC_safe_push (rtx, heap, *next, dest);
}
}
}
return cur_args_size;
}
/* Walk the whole function and compute args_size on BARRIERs. */
static void
compute_barrier_args_size (void)
{
int max_uid = get_max_uid (), i;
rtx insn;
VEC (rtx, heap) *worklist, *next, *tmp;
barrier_args_size = XNEWVEC (HOST_WIDE_INT, max_uid);
for (i = 0; i < max_uid; i++)
barrier_args_size[i] = -1;
worklist = VEC_alloc (rtx, heap, 20);
next = VEC_alloc (rtx, heap, 20);
insn = get_insns ();
barrier_args_size[INSN_UID (insn)] = 0;
VEC_quick_push (rtx, worklist, insn);
for (;;)
{
while (!VEC_empty (rtx, worklist))
{
rtx prev, body, first_insn;
HOST_WIDE_INT cur_args_size;
first_insn = insn = VEC_pop (rtx, worklist);
cur_args_size = barrier_args_size[INSN_UID (insn)];
prev = prev_nonnote_insn (insn);
if (prev && BARRIER_P (prev))
barrier_args_size[INSN_UID (prev)] = cur_args_size;
for (; insn; insn = NEXT_INSN (insn))
{
if (INSN_DELETED_P (insn) || NOTE_P (insn))
continue;
if (BARRIER_P (insn))
break;
if (LABEL_P (insn))
{
if (insn == first_insn)
continue;
else if (barrier_args_size[INSN_UID (insn)] < 0)
{
barrier_args_size[INSN_UID (insn)] = cur_args_size;
continue;
}
else
{
/* The insns starting with this label have been
already scanned or are in the worklist. */
break;
}
}
body = PATTERN (insn);
if (GET_CODE (body) == SEQUENCE)
{
HOST_WIDE_INT dest_args_size = cur_args_size;
for (i = 1; i < XVECLEN (body, 0); i++)
if (INSN_ANNULLED_BRANCH_P (XVECEXP (body, 0, 0))
&& INSN_FROM_TARGET_P (XVECEXP (body, 0, i)))
dest_args_size
= compute_barrier_args_size_1 (XVECEXP (body, 0, i),
dest_args_size, &next);
else
cur_args_size
= compute_barrier_args_size_1 (XVECEXP (body, 0, i),
cur_args_size, &next);
if (INSN_ANNULLED_BRANCH_P (XVECEXP (body, 0, 0)))
compute_barrier_args_size_1 (XVECEXP (body, 0, 0),
dest_args_size, &next);
else
cur_args_size
= compute_barrier_args_size_1 (XVECEXP (body, 0, 0),
cur_args_size, &next);
}
else
cur_args_size
= compute_barrier_args_size_1 (insn, cur_args_size, &next);
}
}
if (VEC_empty (rtx, next))
break;
/* Swap WORKLIST with NEXT and truncate NEXT for next iteration. */
tmp = next;
next = worklist;
worklist = tmp;
VEC_truncate (rtx, next, 0);
}
VEC_free (rtx, heap, worklist);
VEC_free (rtx, heap, next);
}
/* Check INSN to see if it looks like a push or a stack adjustment, and
make a note of it if it does. EH uses this information to find out how
much extra space it needs to pop off the stack. */
static void
dwarf2out_stack_adjust (rtx insn, bool after_p)
{
HOST_WIDE_INT offset;
const char *label;
int i;
/* Don't handle epilogues at all. Certainly it would be wrong to do so
with this function. Proper support would require all frame-related
insns to be marked, and to be able to handle saving state around
epilogues textually in the middle of the function. */
if (prologue_epilogue_contains (insn) || sibcall_epilogue_contains (insn))
return;
/* If INSN is an instruction from target of an annulled branch, the
effects are for the target only and so current argument size
shouldn't change at all. */
if (final_sequence
&& INSN_ANNULLED_BRANCH_P (XVECEXP (final_sequence, 0, 0))
&& INSN_FROM_TARGET_P (insn))
return;
/* If only calls can throw, and we have a frame pointer,
save up adjustments until we see the CALL_INSN. */
if (!flag_asynchronous_unwind_tables && cfa.reg != STACK_POINTER_REGNUM)
{
if (CALL_P (insn) && !after_p)
{
/* Extract the size of the args from the CALL rtx itself. */
insn = PATTERN (insn);
if (GET_CODE (insn) == PARALLEL)
insn = XVECEXP (insn, 0, 0);
if (GET_CODE (insn) == SET)
insn = SET_SRC (insn);
gcc_assert (GET_CODE (insn) == CALL);
dwarf2out_args_size ("", INTVAL (XEXP (insn, 1)));
}
return;
}
if (CALL_P (insn) && !after_p)
{
if (!flag_asynchronous_unwind_tables)
dwarf2out_args_size ("", args_size);
return;
}
else if (BARRIER_P (insn))
{
/* Don't call compute_barrier_args_size () if the only
BARRIER is at the end of function. */
if (barrier_args_size == NULL && next_nonnote_insn (insn))
compute_barrier_args_size ();
if (barrier_args_size == NULL)
offset = 0;
else
{
offset = barrier_args_size[INSN_UID (insn)];
if (offset < 0)
offset = 0;
}
offset -= args_size;
#ifndef STACK_GROWS_DOWNWARD
offset = -offset;
#endif
}
else if (GET_CODE (PATTERN (insn)) == SET)
offset = stack_adjust_offset (PATTERN (insn), args_size, 0);
else if (GET_CODE (PATTERN (insn)) == PARALLEL
|| GET_CODE (PATTERN (insn)) == SEQUENCE)
{
/* There may be stack adjustments inside compound insns. Search
for them. */
for (offset = 0, i = XVECLEN (PATTERN (insn), 0) - 1; i >= 0; i--)
if (GET_CODE (XVECEXP (PATTERN (insn), 0, i)) == SET)
offset += stack_adjust_offset (XVECEXP (PATTERN (insn), 0, i),
args_size, offset);
}
else
return;
if (offset == 0)
return;
label = dwarf2out_cfi_label (false);
dwarf2out_args_size_adjust (offset, label);
}
/* Adjust args_size based on stack adjustment OFFSET. */
static void
dwarf2out_args_size_adjust (HOST_WIDE_INT offset, const char *label)
{
if (cfa.reg == STACK_POINTER_REGNUM)
cfa.offset += offset;
if (cfa_store.reg == STACK_POINTER_REGNUM)
cfa_store.offset += offset;
#ifndef STACK_GROWS_DOWNWARD
offset = -offset;
#endif
args_size += offset;
if (args_size < 0)
args_size = 0;
def_cfa_1 (label, &cfa);
if (flag_asynchronous_unwind_tables)
dwarf2out_args_size (label, args_size);
}
#endif
/* We delay emitting a register save until either (a) we reach the end
of the prologue or (b) the register is clobbered. This clusters
register saves so that there are fewer pc advances. */
struct queued_reg_save GTY(())
{
struct queued_reg_save *next;
rtx reg;
HOST_WIDE_INT cfa_offset;
rtx saved_reg;
};
static GTY(()) struct queued_reg_save *queued_reg_saves;
/* The caller's ORIG_REG is saved in SAVED_IN_REG. */
struct reg_saved_in_data GTY(()) {
rtx orig_reg;
rtx saved_in_reg;
};
/* A list of registers saved in other registers.
The list intentionally has a small maximum capacity of 4; if your
port needs more than that, you might consider implementing a
more efficient data structure. */
static GTY(()) struct reg_saved_in_data regs_saved_in_regs[4];
static GTY(()) size_t num_regs_saved_in_regs;
#if defined (DWARF2_DEBUGGING_INFO) || defined (DWARF2_UNWIND_INFO)
static const char *last_reg_save_label;
/* Add an entry to QUEUED_REG_SAVES saying that REG is now saved at
SREG, or if SREG is NULL then it is saved at OFFSET to the CFA. */
static void
queue_reg_save (const char *label, rtx reg, rtx sreg, HOST_WIDE_INT offset)
{
struct queued_reg_save *q;
/* Duplicates waste space, but it's also necessary to remove them
for correctness, since the queue gets output in reverse
order. */
for (q = queued_reg_saves; q != NULL; q = q->next)
if (REGNO (q->reg) == REGNO (reg))
break;
if (q == NULL)
{
q = GGC_NEW (struct queued_reg_save);
q->next = queued_reg_saves;
queued_reg_saves = q;
}
q->reg = reg;
q->cfa_offset = offset;
q->saved_reg = sreg;
last_reg_save_label = label;
}
/* Output all the entries in QUEUED_REG_SAVES. */
static void
flush_queued_reg_saves (void)
{
struct queued_reg_save *q;
for (q = queued_reg_saves; q; q = q->next)
{
size_t i;
unsigned int reg, sreg;
for (i = 0; i < num_regs_saved_in_regs; i++)
if (REGNO (regs_saved_in_regs[i].orig_reg) == REGNO (q->reg))
break;
if (q->saved_reg && i == num_regs_saved_in_regs)
{
gcc_assert (i != ARRAY_SIZE (regs_saved_in_regs));
num_regs_saved_in_regs++;
}
if (i != num_regs_saved_in_regs)
{
regs_saved_in_regs[i].orig_reg = q->reg;
regs_saved_in_regs[i].saved_in_reg = q->saved_reg;
}
reg = DWARF_FRAME_REGNUM (REGNO (q->reg));
if (q->saved_reg)
sreg = DWARF_FRAME_REGNUM (REGNO (q->saved_reg));
else
sreg = INVALID_REGNUM;
reg_save (last_reg_save_label, reg, sreg, q->cfa_offset);
}
queued_reg_saves = NULL;
last_reg_save_label = NULL;
}
/* Does INSN clobber any register which QUEUED_REG_SAVES lists a saved
location for? Or, does it clobber a register which we've previously
said that some other register is saved in, and for which we now
have a new location for? */
static bool
clobbers_queued_reg_save (const_rtx insn)
{
struct queued_reg_save *q;
for (q = queued_reg_saves; q; q = q->next)
{
size_t i;
if (modified_in_p (q->reg, insn))
return true;
for (i = 0; i < num_regs_saved_in_regs; i++)
if (REGNO (q->reg) == REGNO (regs_saved_in_regs[i].orig_reg)
&& modified_in_p (regs_saved_in_regs[i].saved_in_reg, insn))
return true;
}
return false;
}
/* Entry point for saving the first register into the second. */
void
dwarf2out_reg_save_reg (const char *label, rtx reg, rtx sreg)
{
size_t i;
unsigned int regno, sregno;
for (i = 0; i < num_regs_saved_in_regs; i++)
if (REGNO (regs_saved_in_regs[i].orig_reg) == REGNO (reg))
break;
if (i == num_regs_saved_in_regs)
{
gcc_assert (i != ARRAY_SIZE (regs_saved_in_regs));
num_regs_saved_in_regs++;
}
regs_saved_in_regs[i].orig_reg = reg;
regs_saved_in_regs[i].saved_in_reg = sreg;
regno = DWARF_FRAME_REGNUM (REGNO (reg));
sregno = DWARF_FRAME_REGNUM (REGNO (sreg));
reg_save (label, regno, sregno, 0);
}
/* What register, if any, is currently saved in REG? */
static rtx
reg_saved_in (rtx reg)
{
unsigned int regn = REGNO (reg);
size_t i;
struct queued_reg_save *q;
for (q = queued_reg_saves; q; q = q->next)
if (q->saved_reg && regn == REGNO (q->saved_reg))
return q->reg;
for (i = 0; i < num_regs_saved_in_regs; i++)
if (regs_saved_in_regs[i].saved_in_reg
&& regn == REGNO (regs_saved_in_regs[i].saved_in_reg))
return regs_saved_in_regs[i].orig_reg;
return NULL_RTX;
}
/* A temporary register holding an integral value used in adjusting SP
or setting up the store_reg. The "offset" field holds the integer
value, not an offset. */
static dw_cfa_location cfa_temp;
/* Record call frame debugging information for an expression EXPR,
which either sets SP or FP (adjusting how we calculate the frame
address) or saves a register to the stack or another register.
LABEL indicates the address of EXPR.
This function encodes a state machine mapping rtxes to actions on
cfa, cfa_store, and cfa_temp.reg. We describe these rules so
users need not read the source code.
The High-Level Picture
Changes in the register we use to calculate the CFA: Currently we
assume that if you copy the CFA register into another register, we
should take the other one as the new CFA register; this seems to
work pretty well. If it's wrong for some target, it's simple
enough not to set RTX_FRAME_RELATED_P on the insn in question.
Changes in the register we use for saving registers to the stack:
This is usually SP, but not always. Again, we deduce that if you
copy SP into another register (and SP is not the CFA register),
then the new register is the one we will be using for register
saves. This also seems to work.
Register saves: There's not much guesswork about this one; if
RTX_FRAME_RELATED_P is set on an insn which modifies memory, it's a
register save, and the register used to calculate the destination
had better be the one we think we're using for this purpose.
It's also assumed that a copy from a call-saved register to another
register is saving that register if RTX_FRAME_RELATED_P is set on
that instruction. If the copy is from a call-saved register to
the *same* register, that means that the register is now the same
value as in the caller.
Except: If the register being saved is the CFA register, and the
offset is nonzero, we are saving the CFA, so we assume we have to
use DW_CFA_def_cfa_expression. If the offset is 0, we assume that
the intent is to save the value of SP from the previous frame.
In addition, if a register has previously been saved to a different
register,
Invariants / Summaries of Rules
cfa current rule for calculating the CFA. It usually
consists of a register and an offset.
cfa_store register used by prologue code to save things to the stack
cfa_store.offset is the offset from the value of
cfa_store.reg to the actual CFA
cfa_temp register holding an integral value. cfa_temp.offset
stores the value, which will be used to adjust the
stack pointer. cfa_temp is also used like cfa_store,
to track stores to the stack via fp or a temp reg.
Rules 1- 4: Setting a register's value to cfa.reg or an expression
with cfa.reg as the first operand changes the cfa.reg and its
cfa.offset. Rule 1 and 4 also set cfa_temp.reg and
cfa_temp.offset.
Rules 6- 9: Set a non-cfa.reg register value to a constant or an
expression yielding a constant. This sets cfa_temp.reg
and cfa_temp.offset.
Rule 5: Create a new register cfa_store used to save items to the
stack.
Rules 10-14: Save a register to the stack. Define offset as the
difference of the original location and cfa_store's
location (or cfa_temp's location if cfa_temp is used).
Rules 16-20: If AND operation happens on sp in prologue, we assume
stack is realigned. We will use a group of DW_OP_XXX
expressions to represent the location of the stored
register instead of CFA+offset.
The Rules
"{a,b}" indicates a choice of a xor b.
"<reg>:cfa.reg" indicates that <reg> must equal cfa.reg.
Rule 1:
(set <reg1> <reg2>:cfa.reg)
effects: cfa.reg = <reg1>
cfa.offset unchanged
cfa_temp.reg = <reg1>
cfa_temp.offset = cfa.offset
Rule 2:
(set sp ({minus,plus,losum} {sp,fp}:cfa.reg
{<const_int>,<reg>:cfa_temp.reg}))
effects: cfa.reg = sp if fp used
cfa.offset += {+/- <const_int>, cfa_temp.offset} if cfa.reg==sp
cfa_store.offset += {+/- <const_int>, cfa_temp.offset}
if cfa_store.reg==sp
Rule 3:
(set fp ({minus,plus,losum} <reg>:cfa.reg <const_int>))
effects: cfa.reg = fp
cfa_offset += +/- <const_int>
Rule 4:
(set <reg1> ({plus,losum} <reg2>:cfa.reg <const_int>))
constraints: <reg1> != fp
<reg1> != sp
effects: cfa.reg = <reg1>
cfa_temp.reg = <reg1>
cfa_temp.offset = cfa.offset
Rule 5:
(set <reg1> (plus <reg2>:cfa_temp.reg sp:cfa.reg))
constraints: <reg1> != fp
<reg1> != sp
effects: cfa_store.reg = <reg1>
cfa_store.offset = cfa.offset - cfa_temp.offset
Rule 6:
(set <reg> <const_int>)
effects: cfa_temp.reg = <reg>
cfa_temp.offset = <const_int>
Rule 7:
(set <reg1>:cfa_temp.reg (ior <reg2>:cfa_temp.reg <const_int>))
effects: cfa_temp.reg = <reg1>
cfa_temp.offset |= <const_int>
Rule 8:
(set <reg> (high <exp>))
effects: none
Rule 9:
(set <reg> (lo_sum <exp> <const_int>))
effects: cfa_temp.reg = <reg>
cfa_temp.offset = <const_int>
Rule 10:
(set (mem (pre_modify sp:cfa_store (???? <reg1> <const_int>))) <reg2>)
effects: cfa_store.offset -= <const_int>
cfa.offset = cfa_store.offset if cfa.reg == sp
cfa.reg = sp
cfa.base_offset = -cfa_store.offset
Rule 11:
(set (mem ({pre_inc,pre_dec} sp:cfa_store.reg)) <reg>)
effects: cfa_store.offset += -/+ mode_size(mem)
cfa.offset = cfa_store.offset if cfa.reg == sp
cfa.reg = sp
cfa.base_offset = -cfa_store.offset
Rule 12:
(set (mem ({minus,plus,losum} <reg1>:{cfa_store,cfa_temp} <const_int>))
<reg2>)
effects: cfa.reg = <reg1>
cfa.base_offset = -/+ <const_int> - {cfa_store,cfa_temp}.offset
Rule 13:
(set (mem <reg1>:{cfa_store,cfa_temp}) <reg2>)
effects: cfa.reg = <reg1>
cfa.base_offset = -{cfa_store,cfa_temp}.offset
Rule 14:
(set (mem (postinc <reg1>:cfa_temp <const_int>)) <reg2>)
effects: cfa.reg = <reg1>
cfa.base_offset = -cfa_temp.offset
cfa_temp.offset -= mode_size(mem)
Rule 15:
(set <reg> {unspec, unspec_volatile})
effects: target-dependent
Rule 16:
(set sp (and: sp <const_int>))
constraints: cfa_store.reg == sp
effects: current_fde.stack_realign = 1
cfa_store.offset = 0
fde->drap_reg = cfa.reg if cfa.reg != sp and cfa.reg != fp
Rule 17:
(set (mem ({pre_inc, pre_dec} sp)) (mem (plus (cfa.reg) (const_int))))
effects: cfa_store.offset += -/+ mode_size(mem)
Rule 18:
(set (mem ({pre_inc, pre_dec} sp)) fp)
constraints: fde->stack_realign == 1
effects: cfa_store.offset = 0
cfa.reg != HARD_FRAME_POINTER_REGNUM
Rule 19:
(set (mem ({pre_inc, pre_dec} sp)) cfa.reg)
constraints: fde->stack_realign == 1
&& cfa.offset == 0
&& cfa.indirect == 0
&& cfa.reg != HARD_FRAME_POINTER_REGNUM
effects: Use DW_CFA_def_cfa_expression to define cfa
cfa.reg == fde->drap_reg
Rule 20:
(set reg fde->drap_reg)
constraints: fde->vdrap_reg == INVALID_REGNUM
effects: fde->vdrap_reg = reg.
(set mem fde->drap_reg)
constraints: fde->drap_reg_saved == 1
effects: none. */
static void
dwarf2out_frame_debug_expr (rtx expr, const char *label)
{
rtx src, dest, span;
HOST_WIDE_INT offset;
dw_fde_ref fde;
/* If RTX_FRAME_RELATED_P is set on a PARALLEL, process each member of
the PARALLEL independently. The first element is always processed if
it is a SET. This is for backward compatibility. Other elements
are processed only if they are SETs and the RTX_FRAME_RELATED_P
flag is set in them. */
if (GET_CODE (expr) == PARALLEL || GET_CODE (expr) == SEQUENCE)
{
int par_index;
int limit = XVECLEN (expr, 0);
rtx elem;
/* PARALLELs have strict read-modify-write semantics, so we
ought to evaluate every rvalue before changing any lvalue.
It's cumbersome to do that in general, but there's an
easy approximation that is enough for all current users:
handle register saves before register assignments. */
if (GET_CODE (expr) == PARALLEL)
for (par_index = 0; par_index < limit; par_index++)
{
elem = XVECEXP (expr, 0, par_index);
if (GET_CODE (elem) == SET
&& MEM_P (SET_DEST (elem))
&& (RTX_FRAME_RELATED_P (elem) || par_index == 0))
dwarf2out_frame_debug_expr (elem, label);
}
for (par_index = 0; par_index < limit; par_index++)
{
elem = XVECEXP (expr, 0, par_index);
if (GET_CODE (elem) == SET
&& (!MEM_P (SET_DEST (elem)) || GET_CODE (expr) == SEQUENCE)
&& (RTX_FRAME_RELATED_P (elem) || par_index == 0))
dwarf2out_frame_debug_expr (elem, label);
else if (GET_CODE (elem) == SET
&& par_index != 0
&& !RTX_FRAME_RELATED_P (elem))
{
/* Stack adjustment combining might combine some post-prologue
stack adjustment into a prologue stack adjustment. */
HOST_WIDE_INT offset = stack_adjust_offset (elem, args_size, 0);
if (offset != 0)
dwarf2out_args_size_adjust (offset, label);
}
}
return;
}
gcc_assert (GET_CODE (expr) == SET);
src = SET_SRC (expr);
dest = SET_DEST (expr);
if (REG_P (src))
{
rtx rsi = reg_saved_in (src);
if (rsi)
src = rsi;
}
fde = current_fde ();
if (GET_CODE (src) == REG
&& fde
&& fde->drap_reg == REGNO (src)
&& (fde->drap_reg_saved
|| GET_CODE (dest) == REG))
{
/* Rule 20 */
/* If we are saving dynamic realign argument pointer to a
register, the destination is virtual dynamic realign
argument pointer. It may be used to access argument. */
if (GET_CODE (dest) == REG)
{
gcc_assert (fde->vdrap_reg == INVALID_REGNUM);
fde->vdrap_reg = REGNO (dest);
}
return;
}
switch (GET_CODE (dest))
{
case REG:
switch (GET_CODE (src))
{
/* Setting FP from SP. */
case REG:
if (cfa.reg == (unsigned) REGNO (src))
{
/* Rule 1 */
/* Update the CFA rule wrt SP or FP. Make sure src is
relative to the current CFA register.
We used to require that dest be either SP or FP, but the
ARM copies SP to a temporary register, and from there to
FP. So we just rely on the backends to only set
RTX_FRAME_RELATED_P on appropriate insns. */
cfa.reg = REGNO (dest);
cfa_temp.reg = cfa.reg;
cfa_temp.offset = cfa.offset;
}
else
{
/* Saving a register in a register. */
gcc_assert (!fixed_regs [REGNO (dest)]
/* For the SPARC and its register window. */
|| (DWARF_FRAME_REGNUM (REGNO (src))
== DWARF_FRAME_RETURN_COLUMN));
/* After stack is aligned, we can only save SP in FP
if drap register is used. In this case, we have
to restore stack pointer with the CFA value and we
don't generate this DWARF information. */
if (fde
&& fde->stack_realign
&& REGNO (src) == STACK_POINTER_REGNUM)
gcc_assert (REGNO (dest) == HARD_FRAME_POINTER_REGNUM
&& fde->drap_reg != INVALID_REGNUM
&& cfa.reg != REGNO (src));
else
queue_reg_save (label, src, dest, 0);
}
break;
case PLUS:
case MINUS:
case LO_SUM:
if (dest == stack_pointer_rtx)
{
/* Rule 2 */
/* Adjusting SP. */
switch (GET_CODE (XEXP (src, 1)))
{
case CONST_INT:
offset = INTVAL (XEXP (src, 1));
break;
case REG:
gcc_assert ((unsigned) REGNO (XEXP (src, 1))
== cfa_temp.reg);
offset = cfa_temp.offset;
break;
default:
gcc_unreachable ();
}
if (XEXP (src, 0) == hard_frame_pointer_rtx)
{
/* Restoring SP from FP in the epilogue. */
gcc_assert (cfa.reg == (unsigned) HARD_FRAME_POINTER_REGNUM);
cfa.reg = STACK_POINTER_REGNUM;
}
else if (GET_CODE (src) == LO_SUM)
/* Assume we've set the source reg of the LO_SUM from sp. */
;
else
gcc_assert (XEXP (src, 0) == stack_pointer_rtx);
if (GET_CODE (src) != MINUS)
offset = -offset;
if (cfa.reg == STACK_POINTER_REGNUM)
cfa.offset += offset;
if (cfa_store.reg == STACK_POINTER_REGNUM)
cfa_store.offset += offset;
}
else if (dest == hard_frame_pointer_rtx)
{
/* Rule 3 */
/* Either setting the FP from an offset of the SP,
or adjusting the FP */
gcc_assert (frame_pointer_needed);
gcc_assert (REG_P (XEXP (src, 0))
&& (unsigned) REGNO (XEXP (src, 0)) == cfa.reg
&& GET_CODE (XEXP (src, 1)) == CONST_INT);
offset = INTVAL (XEXP (src, 1));
if (GET_CODE (src) != MINUS)
offset = -offset;
cfa.offset += offset;
cfa.reg = HARD_FRAME_POINTER_REGNUM;
}
else
{
gcc_assert (GET_CODE (src) != MINUS);
/* Rule 4 */
if (REG_P (XEXP (src, 0))
&& REGNO (XEXP (src, 0)) == cfa.reg
&& GET_CODE (XEXP (src, 1)) == CONST_INT)
{
/* Setting a temporary CFA register that will be copied
into the FP later on. */
offset = - INTVAL (XEXP (src, 1));
cfa.offset += offset;
cfa.reg = REGNO (dest);
/* Or used to save regs to the stack. */
cfa_temp.reg = cfa.reg;
cfa_temp.offset = cfa.offset;
}
/* Rule 5 */
else if (REG_P (XEXP (src, 0))
&& REGNO (XEXP (src, 0)) == cfa_temp.reg
&& XEXP (src, 1) == stack_pointer_rtx)
{
/* Setting a scratch register that we will use instead
of SP for saving registers to the stack. */
gcc_assert (cfa.reg == STACK_POINTER_REGNUM);
cfa_store.reg = REGNO (dest);
cfa_store.offset = cfa.offset - cfa_temp.offset;
}
/* Rule 9 */
else if (GET_CODE (src) == LO_SUM
&& GET_CODE (XEXP (src, 1)) == CONST_INT)
{
cfa_temp.reg = REGNO (dest);
cfa_temp.offset = INTVAL (XEXP (src, 1));
}
else
gcc_unreachable ();
}
break;
/* Rule 6 */
case CONST_INT:
cfa_temp.reg = REGNO (dest);
cfa_temp.offset = INTVAL (src);
break;
/* Rule 7 */
case IOR:
gcc_assert (REG_P (XEXP (src, 0))
&& (unsigned) REGNO (XEXP (src, 0)) == cfa_temp.reg
&& GET_CODE (XEXP (src, 1)) == CONST_INT);
if ((unsigned) REGNO (dest) != cfa_temp.reg)
cfa_temp.reg = REGNO (dest);
cfa_temp.offset |= INTVAL (XEXP (src, 1));
break;
/* Skip over HIGH, assuming it will be followed by a LO_SUM,
which will fill in all of the bits. */
/* Rule 8 */
case HIGH:
break;
/* Rule 15 */
case UNSPEC:
case UNSPEC_VOLATILE:
gcc_assert (targetm.dwarf_handle_frame_unspec);
targetm.dwarf_handle_frame_unspec (label, expr, XINT (src, 1));
return;
/* Rule 16 */
case AND:
/* If this AND operation happens on stack pointer in prologue,
we assume the stack is realigned and we extract the
alignment. */
if (fde && XEXP (src, 0) == stack_pointer_rtx)
{
gcc_assert (cfa_store.reg == REGNO (XEXP (src, 0)));
fde->stack_realign = 1;
fde->stack_realignment = INTVAL (XEXP (src, 1));
cfa_store.offset = 0;
if (cfa.reg != STACK_POINTER_REGNUM
&& cfa.reg != HARD_FRAME_POINTER_REGNUM)
fde->drap_reg = cfa.reg;
}
return;
default:
gcc_unreachable ();
}
def_cfa_1 (label, &cfa);
break;
case MEM:
/* Saving a register to the stack. Make sure dest is relative to the
CFA register. */
switch (GET_CODE (XEXP (dest, 0)))
{
/* Rule 10 */
/* With a push. */
case PRE_MODIFY:
/* We can't handle variable size modifications. */
gcc_assert (GET_CODE (XEXP (XEXP (XEXP (dest, 0), 1), 1))
== CONST_INT);
offset = -INTVAL (XEXP (XEXP (XEXP (dest, 0), 1), 1));
gcc_assert (REGNO (XEXP (XEXP (dest, 0), 0)) == STACK_POINTER_REGNUM
&& cfa_store.reg == STACK_POINTER_REGNUM);
cfa_store.offset += offset;
if (cfa.reg == STACK_POINTER_REGNUM)
cfa.offset = cfa_store.offset;
offset = -cfa_store.offset;
break;
/* Rule 11 */
case PRE_INC:
case PRE_DEC:
offset = GET_MODE_SIZE (GET_MODE (dest));
if (GET_CODE (XEXP (dest, 0)) == PRE_INC)
offset = -offset;
gcc_assert ((REGNO (XEXP (XEXP (dest, 0), 0))
== STACK_POINTER_REGNUM)
&& cfa_store.reg == STACK_POINTER_REGNUM);
cfa_store.offset += offset;
/* Rule 18: If stack is aligned, we will use FP as a
reference to represent the address of the stored
regiser. */
if (fde
&& fde->stack_realign
&& src == hard_frame_pointer_rtx)
{
gcc_assert (cfa.reg != HARD_FRAME_POINTER_REGNUM);
cfa_store.offset = 0;
}
if (cfa.reg == STACK_POINTER_REGNUM)
cfa.offset = cfa_store.offset;
offset = -cfa_store.offset;
break;
/* Rule 12 */
/* With an offset. */
case PLUS:
case MINUS:
case LO_SUM:
{
int regno;
gcc_assert (GET_CODE (XEXP (XEXP (dest, 0), 1)) == CONST_INT
&& REG_P (XEXP (XEXP (dest, 0), 0)));
offset = INTVAL (XEXP (XEXP (dest, 0), 1));
if (GET_CODE (XEXP (dest, 0)) == MINUS)
offset = -offset;
regno = REGNO (XEXP (XEXP (dest, 0), 0));
if (cfa_store.reg == (unsigned) regno)
offset -= cfa_store.offset;
else
{
gcc_assert (cfa_temp.reg == (unsigned) regno);
offset -= cfa_temp.offset;
}
}
break;
/* Rule 13 */
/* Without an offset. */
case REG:
{
int regno = REGNO (XEXP (dest, 0));
if (cfa_store.reg == (unsigned) regno)
offset = -cfa_store.offset;
else
{
gcc_assert (cfa_temp.reg == (unsigned) regno);
offset = -cfa_temp.offset;
}
}
break;
/* Rule 14 */
case POST_INC:
gcc_assert (cfa_temp.reg
== (unsigned) REGNO (XEXP (XEXP (dest, 0), 0)));
offset = -cfa_temp.offset;
cfa_temp.offset -= GET_MODE_SIZE (GET_MODE (dest));
break;
default:
gcc_unreachable ();
}
/* Rule 17 */
/* If the source operand of this MEM operation is not a
register, basically the source is return address. Here
we only care how much stack grew and we don't save it. */
if (!REG_P (src))
break;
if (REGNO (src) != STACK_POINTER_REGNUM
&& REGNO (src) != HARD_FRAME_POINTER_REGNUM
&& (unsigned) REGNO (src) == cfa.reg)
{
/* We're storing the current CFA reg into the stack. */
if (cfa.offset == 0)
{
/* Rule 19 */
/* If stack is aligned, putting CFA reg into stack means
we can no longer use reg + offset to represent CFA.
Here we use DW_CFA_def_cfa_expression instead. The
result of this expression equals to the original CFA
value. */
if (fde
&& fde->stack_realign
&& cfa.indirect == 0
&& cfa.reg != HARD_FRAME_POINTER_REGNUM)
{
dw_cfa_location cfa_exp;
gcc_assert (fde->drap_reg == cfa.reg);
cfa_exp.indirect = 1;
cfa_exp.reg = HARD_FRAME_POINTER_REGNUM;
cfa_exp.base_offset = offset;
cfa_exp.offset = 0;
fde->drap_reg_saved = 1;
def_cfa_1 (label, &cfa_exp);
break;
}
/* If the source register is exactly the CFA, assume
we're saving SP like any other register; this happens
on the ARM. */
def_cfa_1 (label, &cfa);
queue_reg_save (label, stack_pointer_rtx, NULL_RTX, offset);
break;
}
else
{
/* Otherwise, we'll need to look in the stack to
calculate the CFA. */
rtx x = XEXP (dest, 0);
if (!REG_P (x))
x = XEXP (x, 0);
gcc_assert (REG_P (x));
cfa.reg = REGNO (x);
cfa.base_offset = offset;
cfa.indirect = 1;
def_cfa_1 (label, &cfa);
break;
}
}
def_cfa_1 (label, &cfa);
{
span = targetm.dwarf_register_span (src);
if (!span)
queue_reg_save (label, src, NULL_RTX, offset);
else
{
/* We have a PARALLEL describing where the contents of SRC
live. Queue register saves for each piece of the
PARALLEL. */
int par_index;
int limit;
HOST_WIDE_INT span_offset = offset;
gcc_assert (GET_CODE (span) == PARALLEL);
limit = XVECLEN (span, 0);
for (par_index = 0; par_index < limit; par_index++)
{
rtx elem = XVECEXP (span, 0, par_index);
queue_reg_save (label, elem, NULL_RTX, span_offset);
span_offset += GET_MODE_SIZE (GET_MODE (elem));
}
}
}
break;
default:
gcc_unreachable ();
}
}
/* Record call frame debugging information for INSN, which either
sets SP or FP (adjusting how we calculate the frame address) or saves a
register to the stack. If INSN is NULL_RTX, initialize our state.
If AFTER_P is false, we're being called before the insn is emitted,
otherwise after. Call instructions get invoked twice. */
void
dwarf2out_frame_debug (rtx insn, bool after_p)
{
const char *label;
rtx src;
if (insn == NULL_RTX)
{
size_t i;
/* Flush any queued register saves. */
flush_queued_reg_saves ();
/* Set up state for generating call frame debug info. */
lookup_cfa (&cfa);
gcc_assert (cfa.reg
== (unsigned long)DWARF_FRAME_REGNUM (STACK_POINTER_REGNUM));
cfa.reg = STACK_POINTER_REGNUM;
cfa_store = cfa;
cfa_temp.reg = -1;
cfa_temp.offset = 0;
for (i = 0; i < num_regs_saved_in_regs; i++)
{
regs_saved_in_regs[i].orig_reg = NULL_RTX;
regs_saved_in_regs[i].saved_in_reg = NULL_RTX;
}
num_regs_saved_in_regs = 0;
if (barrier_args_size)
{
XDELETEVEC (barrier_args_size);
barrier_args_size = NULL;
}
return;
}
if (!NONJUMP_INSN_P (insn) || clobbers_queued_reg_save (insn))
flush_queued_reg_saves ();
if (! RTX_FRAME_RELATED_P (insn))
{
if (!ACCUMULATE_OUTGOING_ARGS)
dwarf2out_stack_adjust (insn, after_p);
return;
}
label = dwarf2out_cfi_label (false);
src = find_reg_note (insn, REG_FRAME_RELATED_EXPR, NULL_RTX);
if (src)
insn = XEXP (src, 0);
else
insn = PATTERN (insn);
dwarf2out_frame_debug_expr (insn, label);
}
#endif
/* Describe for the GTY machinery what parts of dw_cfi_oprnd1 are used. */
static enum dw_cfi_oprnd_type dw_cfi_oprnd1_desc
(enum dwarf_call_frame_info cfi);
static enum dw_cfi_oprnd_type
dw_cfi_oprnd1_desc (enum dwarf_call_frame_info cfi)
{
switch (cfi)
{
case DW_CFA_nop:
case DW_CFA_GNU_window_save:
return dw_cfi_oprnd_unused;
case DW_CFA_set_loc:
case DW_CFA_advance_loc1:
case DW_CFA_advance_loc2:
case DW_CFA_advance_loc4:
case DW_CFA_MIPS_advance_loc8:
return dw_cfi_oprnd_addr;
case DW_CFA_offset:
case DW_CFA_offset_extended:
case DW_CFA_def_cfa:
case DW_CFA_offset_extended_sf:
case DW_CFA_def_cfa_sf:
case DW_CFA_restore_extended:
case DW_CFA_undefined:
case DW_CFA_same_value:
case DW_CFA_def_cfa_register:
case DW_CFA_register:
return dw_cfi_oprnd_reg_num;
case DW_CFA_def_cfa_offset:
case DW_CFA_GNU_args_size:
case DW_CFA_def_cfa_offset_sf:
return dw_cfi_oprnd_offset;
case DW_CFA_def_cfa_expression:
case DW_CFA_expression:
return dw_cfi_oprnd_loc;
default:
gcc_unreachable ();
}
}
/* Describe for the GTY machinery what parts of dw_cfi_oprnd2 are used. */
static enum dw_cfi_oprnd_type dw_cfi_oprnd2_desc
(enum dwarf_call_frame_info cfi);
static enum dw_cfi_oprnd_type
dw_cfi_oprnd2_desc (enum dwarf_call_frame_info cfi)
{
switch (cfi)
{
case DW_CFA_def_cfa:
case DW_CFA_def_cfa_sf:
case DW_CFA_offset:
case DW_CFA_offset_extended_sf:
case DW_CFA_offset_extended:
return dw_cfi_oprnd_offset;
case DW_CFA_register:
return dw_cfi_oprnd_reg_num;
default:
return dw_cfi_oprnd_unused;
}
}
#if defined (DWARF2_DEBUGGING_INFO) || defined (DWARF2_UNWIND_INFO)
/* Switch to eh_frame_section. If we don't have an eh_frame_section,
switch to the data section instead, and write out a synthetic label
for collect2. */
static void
switch_to_eh_frame_section (void)
{
tree label;
#ifdef EH_FRAME_SECTION_NAME
if (eh_frame_section == 0)
{
int flags;
if (EH_TABLES_CAN_BE_READ_ONLY)
{
int fde_encoding;
int per_encoding;
int lsda_encoding;
fde_encoding = ASM_PREFERRED_EH_DATA_FORMAT (/*code=*/1,
/*global=*/0);
per_encoding = ASM_PREFERRED_EH_DATA_FORMAT (/*code=*/2,
/*global=*/1);
lsda_encoding = ASM_PREFERRED_EH_DATA_FORMAT (/*code=*/0,
/*global=*/0);
flags = ((! flag_pic
|| ((fde_encoding & 0x70) != DW_EH_PE_absptr
&& (fde_encoding & 0x70) != DW_EH_PE_aligned
&& (per_encoding & 0x70) != DW_EH_PE_absptr
&& (per_encoding & 0x70) != DW_EH_PE_aligned
&& (lsda_encoding & 0x70) != DW_EH_PE_absptr
&& (lsda_encoding & 0x70) != DW_EH_PE_aligned))
? 0 : SECTION_WRITE);
}
else
flags = SECTION_WRITE;
eh_frame_section = get_section (EH_FRAME_SECTION_NAME, flags, NULL);
}
#endif
if (eh_frame_section)
switch_to_section (eh_frame_section);
else
{
/* We have no special eh_frame section. Put the information in
the data section and emit special labels to guide collect2. */
switch_to_section (data_section);
label = get_file_function_name ("F");
ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (PTR_SIZE));
targetm.asm_out.globalize_label (asm_out_file,
IDENTIFIER_POINTER (label));
ASM_OUTPUT_LABEL (asm_out_file, IDENTIFIER_POINTER (label));
}
}
/* Divide OFF by DWARF_CIE_DATA_ALIGNMENT, asserting no remainder. */
static HOST_WIDE_INT
div_data_align (HOST_WIDE_INT off)
{
HOST_WIDE_INT r = off / DWARF_CIE_DATA_ALIGNMENT;
gcc_assert (r * DWARF_CIE_DATA_ALIGNMENT == off);
return r;
}
/* Output a Call Frame Information opcode and its operand(s). */
static void
output_cfi (dw_cfi_ref cfi, dw_fde_ref fde, int for_eh)
{
unsigned long r;
HOST_WIDE_INT off;
if (cfi->dw_cfi_opc == DW_CFA_advance_loc)
dw2_asm_output_data (1, (cfi->dw_cfi_opc
| (cfi->dw_cfi_oprnd1.dw_cfi_offset & 0x3f)),
"DW_CFA_advance_loc " HOST_WIDE_INT_PRINT_HEX,
((unsigned HOST_WIDE_INT)
cfi->dw_cfi_oprnd1.dw_cfi_offset));
else if (cfi->dw_cfi_opc == DW_CFA_offset)
{
r = DWARF2_FRAME_REG_OUT (cfi->dw_cfi_oprnd1.dw_cfi_reg_num, for_eh);
dw2_asm_output_data (1, (cfi->dw_cfi_opc | (r & 0x3f)),
"DW_CFA_offset, column 0x%lx", r);
off = div_data_align (cfi->dw_cfi_oprnd2.dw_cfi_offset);
dw2_asm_output_data_uleb128 (off, NULL);
}
else if (cfi->dw_cfi_opc == DW_CFA_restore)
{
r = DWARF2_FRAME_REG_OUT (cfi->dw_cfi_oprnd1.dw_cfi_reg_num, for_eh);
dw2_asm_output_data (1, (cfi->dw_cfi_opc | (r & 0x3f)),
"DW_CFA_restore, column 0x%lx", r);
}
else
{
dw2_asm_output_data (1, cfi->dw_cfi_opc,
"%s", dwarf_cfi_name (cfi->dw_cfi_opc));
switch (cfi->dw_cfi_opc)
{
case DW_CFA_set_loc:
if (for_eh)
dw2_asm_output_encoded_addr_rtx (
ASM_PREFERRED_EH_DATA_FORMAT (/*code=*/1, /*global=*/0),
gen_rtx_SYMBOL_REF (Pmode, cfi->dw_cfi_oprnd1.dw_cfi_addr),
false, NULL);
else
dw2_asm_output_addr (DWARF2_ADDR_SIZE,
cfi->dw_cfi_oprnd1.dw_cfi_addr, NULL);
fde->dw_fde_current_label = cfi->dw_cfi_oprnd1.dw_cfi_addr;
break;
case DW_CFA_advance_loc1:
dw2_asm_output_delta (1, cfi->dw_cfi_oprnd1.dw_cfi_addr,
fde->dw_fde_current_label, NULL);
fde->dw_fde_current_label = cfi->dw_cfi_oprnd1.dw_cfi_addr;
break;
case DW_CFA_advance_loc2:
dw2_asm_output_delta (2, cfi->dw_cfi_oprnd1.dw_cfi_addr,
fde->dw_fde_current_label, NULL);
fde->dw_fde_current_label = cfi->dw_cfi_oprnd1.dw_cfi_addr;
break;
case DW_CFA_advance_loc4:
dw2_asm_output_delta (4, cfi->dw_cfi_oprnd1.dw_cfi_addr,
fde->dw_fde_current_label, NULL);
fde->dw_fde_current_label = cfi->dw_cfi_oprnd1.dw_cfi_addr;
break;
case DW_CFA_MIPS_advance_loc8:
dw2_asm_output_delta (8, cfi->dw_cfi_oprnd1.dw_cfi_addr,
fde->dw_fde_current_label, NULL);
fde->dw_fde_current_label = cfi->dw_cfi_oprnd1.dw_cfi_addr;
break;
case DW_CFA_offset_extended:
r = DWARF2_FRAME_REG_OUT (cfi->dw_cfi_oprnd1.dw_cfi_reg_num, for_eh);
dw2_asm_output_data_uleb128 (r, NULL);
off = div_data_align (cfi->dw_cfi_oprnd2.dw_cfi_offset);
dw2_asm_output_data_uleb128 (off, NULL);
break;
case DW_CFA_def_cfa:
r = DWARF2_FRAME_REG_OUT (cfi->dw_cfi_oprnd1.dw_cfi_reg_num, for_eh);
dw2_asm_output_data_uleb128 (r, NULL);
dw2_asm_output_data_uleb128 (cfi->dw_cfi_oprnd2.dw_cfi_offset, NULL);
break;
case DW_CFA_offset_extended_sf:
r = DWARF2_FRAME_REG_OUT (cfi->dw_cfi_oprnd1.dw_cfi_reg_num, for_eh);
dw2_asm_output_data_uleb128 (r, NULL);
off = div_data_align (cfi->dw_cfi_oprnd2.dw_cfi_offset);
dw2_asm_output_data_sleb128 (off, NULL);
break;
case DW_CFA_def_cfa_sf:
r = DWARF2_FRAME_REG_OUT (cfi->dw_cfi_oprnd1.dw_cfi_reg_num, for_eh);
dw2_asm_output_data_uleb128 (r, NULL);
off = div_data_align (cfi->dw_cfi_oprnd2.dw_cfi_offset);
dw2_asm_output_data_sleb128 (off, NULL);
break;
case DW_CFA_restore_extended:
case DW_CFA_undefined:
case DW_CFA_same_value:
case DW_CFA_def_cfa_register:
r = DWARF2_FRAME_REG_OUT (cfi->dw_cfi_oprnd1.dw_cfi_reg_num, for_eh);
dw2_asm_output_data_uleb128 (r, NULL);
break;
case DW_CFA_register:
r = DWARF2_FRAME_REG_OUT (cfi->dw_cfi_oprnd1.dw_cfi_reg_num, for_eh);
dw2_asm_output_data_uleb128 (r, NULL);
r = DWARF2_FRAME_REG_OUT (cfi->dw_cfi_oprnd2.dw_cfi_reg_num, for_eh);
dw2_asm_output_data_uleb128 (r, NULL);
break;
case DW_CFA_def_cfa_offset:
case DW_CFA_GNU_args_size:
dw2_asm_output_data_uleb128 (cfi->dw_cfi_oprnd1.dw_cfi_offset, NULL);
break;
case DW_CFA_def_cfa_offset_sf:
off = div_data_align (cfi->dw_cfi_oprnd1.dw_cfi_offset);
dw2_asm_output_data_sleb128 (off, NULL);
break;
case DW_CFA_GNU_window_save:
break;
case DW_CFA_def_cfa_expression:
case DW_CFA_expression:
output_cfa_loc (cfi);
break;
case DW_CFA_GNU_negative_offset_extended:
/* Obsoleted by DW_CFA_offset_extended_sf. */
gcc_unreachable ();
default:
break;
}
}
}
/* Similar, but do it via assembler directives instead. */
static void
output_cfi_directive (dw_cfi_ref cfi)
{
unsigned long r, r2;
switch (cfi->dw_cfi_opc)
{
case DW_CFA_advance_loc:
case DW_CFA_advance_loc1:
case DW_CFA_advance_loc2:
case DW_CFA_advance_loc4:
case DW_CFA_MIPS_advance_loc8:
case DW_CFA_set_loc:
/* Should only be created by add_fde_cfi in a code path not
followed when emitting via directives. The assembler is
going to take care of this for us. */
gcc_unreachable ();
case DW_CFA_offset:
case DW_CFA_offset_extended:
case DW_CFA_offset_extended_sf:
r = DWARF2_FRAME_REG_OUT (cfi->dw_cfi_oprnd1.dw_cfi_reg_num, 1);
fprintf (asm_out_file, "\t.cfi_offset %lu, "HOST_WIDE_INT_PRINT_DEC"\n",
r, cfi->dw_cfi_oprnd2.dw_cfi_offset);
break;
case DW_CFA_restore:
case DW_CFA_restore_extended:
r = DWARF2_FRAME_REG_OUT (cfi->dw_cfi_oprnd1.dw_cfi_reg_num, 1);
fprintf (asm_out_file, "\t.cfi_restore %lu\n", r);
break;
case DW_CFA_undefined:
r = DWARF2_FRAME_REG_OUT (cfi->dw_cfi_oprnd1.dw_cfi_reg_num, 1);
fprintf (asm_out_file, "\t.cfi_undefined %lu\n", r);
break;
case DW_CFA_same_value:
r = DWARF2_FRAME_REG_OUT (cfi->dw_cfi_oprnd1.dw_cfi_reg_num, 1);
fprintf (asm_out_file, "\t.cfi_same_value %lu\n", r);
break;
case DW_CFA_def_cfa:
case DW_CFA_def_cfa_sf:
r = DWARF2_FRAME_REG_OUT (cfi->dw_cfi_oprnd1.dw_cfi_reg_num, 1);
fprintf (asm_out_file, "\t.cfi_def_cfa %lu, "HOST_WIDE_INT_PRINT_DEC"\n",
r, cfi->dw_cfi_oprnd2.dw_cfi_offset);
break;
case DW_CFA_def_cfa_register:
r = DWARF2_FRAME_REG_OUT (cfi->dw_cfi_oprnd1.dw_cfi_reg_num, 1);
fprintf (asm_out_file, "\t.cfi_def_cfa_register %lu\n", r);
break;
case DW_CFA_register:
r = DWARF2_FRAME_REG_OUT (cfi->dw_cfi_oprnd1.dw_cfi_reg_num, 1);
r2 = DWARF2_FRAME_REG_OUT (cfi->dw_cfi_oprnd2.dw_cfi_reg_num, 1);
fprintf (asm_out_file, "\t.cfi_register %lu, %lu\n", r, r2);
break;
case DW_CFA_def_cfa_offset:
case DW_CFA_def_cfa_offset_sf:
fprintf (asm_out_file, "\t.cfi_def_cfa_offset "
HOST_WIDE_INT_PRINT_DEC"\n",
cfi->dw_cfi_oprnd1.dw_cfi_offset);
break;
case DW_CFA_GNU_args_size:
fprintf (asm_out_file, "\t.cfi_escape 0x%x,", DW_CFA_GNU_args_size);
dw2_asm_output_data_uleb128_raw (cfi->dw_cfi_oprnd1.dw_cfi_offset);
if (flag_debug_asm)
fprintf (asm_out_file, "\t%s args_size "HOST_WIDE_INT_PRINT_DEC,
ASM_COMMENT_START, cfi->dw_cfi_oprnd1.dw_cfi_offset);
fputc ('\n', asm_out_file);
break;
case DW_CFA_GNU_window_save:
fprintf (asm_out_file, "\t.cfi_window_save\n");
break;
case DW_CFA_def_cfa_expression:
case DW_CFA_expression:
fprintf (asm_out_file, "\t.cfi_escape 0x%x,", cfi->dw_cfi_opc);
output_cfa_loc_raw (cfi);
fputc ('\n', asm_out_file);
break;
default:
gcc_unreachable ();
}
}
/* Output the call frame information used to record information
that relates to calculating the frame pointer, and records the
location of saved registers. */
static void
output_call_frame_info (int for_eh)
{
unsigned int i;
dw_fde_ref fde;
dw_cfi_ref cfi;
char l1[20], l2[20], section_start_label[20];
bool any_lsda_needed = false;
char augmentation[6];
int augmentation_size;
int fde_encoding = DW_EH_PE_absptr;
int per_encoding = DW_EH_PE_absptr;
int lsda_encoding = DW_EH_PE_absptr;
int return_reg;
/* Don't emit a CIE if there won't be any FDEs. */
if (fde_table_in_use == 0)
return;
/* Nothing to do if the assembler's doing it all. */
if (dwarf2out_do_cfi_asm ())
return;
/* If we make FDEs linkonce, we may have to emit an empty label for
an FDE that wouldn't otherwise be emitted. We want to avoid
having an FDE kept around when the function it refers to is
discarded. Example where this matters: a primary function
template in C++ requires EH information, but an explicit
specialization doesn't. */
if (TARGET_USES_WEAK_UNWIND_INFO
&& ! flag_asynchronous_unwind_tables
&& flag_exceptions
&& for_eh)
for (i = 0; i < fde_table_in_use; i++)
if ((fde_table[i].nothrow || fde_table[i].all_throwers_are_sibcalls)
&& !fde_table[i].uses_eh_lsda
&& ! DECL_WEAK (fde_table[i].decl))
targetm.asm_out.unwind_label (asm_out_file, fde_table[i].decl,
for_eh, /* empty */ 1);
/* If we don't have any functions we'll want to unwind out of, don't
emit any EH unwind information. Note that if exceptions aren't
enabled, we won't have collected nothrow information, and if we
asked for asynchronous tables, we always want this info. */
if (for_eh)
{
bool any_eh_needed = !flag_exceptions || flag_asynchronous_unwind_tables;
for (i = 0; i < fde_table_in_use; i++)
if (fde_table[i].uses_eh_lsda)
any_eh_needed = any_lsda_needed = true;
else if (TARGET_USES_WEAK_UNWIND_INFO && DECL_WEAK (fde_table[i].decl))
any_eh_needed = true;
else if (! fde_table[i].nothrow
&& ! fde_table[i].all_throwers_are_sibcalls)
any_eh_needed = true;
if (! any_eh_needed)
return;
}
/* We're going to be generating comments, so turn on app. */
if (flag_debug_asm)
app_enable ();
if (for_eh)
switch_to_eh_frame_section ();
else