api/docs/release.dox

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/**
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\page release_notes Release Notes for Version \DR_VERSION

This section is divided into the following subsections:

 - \ref sec_package
 - \ref sec_changes
 - \ref sec_limits
 - \ref sec_future

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\section sec_package Distribution Contents

The following are part of the DynamoRIO release distribution:

\if profiling
  PR 225255: list profile library too
\endif

 - Four different DynamoRIO libraries: debug and release for each of
   32-bit and 64-bit (for ARM or AArch64 builds, only a single bitwidth
   matching the ISA is provided).
   The debug library enables assertion messages to more easily diagnose
   API usage errors.
 - Four different IA-32/AMD64/ARM/AArch64 decoding static libraries: debug and release
   for each of 32-bit and 64-bit (only 32-bit for ARM and 64-bit for AArch64).
   The debug library enables assertion messages to more easily diagnose
   API usage errors.
 - A variety of DynamoRIO Extension libraries that augment the core
   DynamoRIO API (see \ref page_ext).
 - Additional Extension libraries from the Dr. Memory Framework (DRMF).
   If this documentation is part of a DynamoRIO public release, <a
   href="../../drmemory/drmemory/docs/html/page_drmf.html">this link</a> should
   point at the local documentation for DRMF.
 - The DynamoRIO configuration and execution libraries and command-line
   utilities \c drconfiglib.dll, \c drinjectlib.dll, \c drfrontendlib.lib,
   \c drconfig.exe, \c drrun.exe, and \c drinject.exe.
   On Linux, the tools are named \c drconfig, \c drrun, and \c drinject.
 - A utility \c drview.exe for viewing which processes
   are running under DynamoRIO control (Windows package only).
 - Header files for the DynamoRIO APIs.
 - This documentation.
 - \ref API_samples "Sample clients".
 - A graphical statistics viewer \c DRstats.exe that displays internal
   DynamoRIO statistics as well as custom statistics defined
   by a client (see \ref sec_drstats) (Windows package only).
   DynamoRIO exports a large number of statistics in its debug build, and
   a handful in release builds.
 - A binary tracedump reader, which also functions as a sample
   client using DynamoRIO as a standalone library (see \ref
   sec_standalone).
 - A number of end-user tools including a code coverage tool (see \ref
   page_drcov), a multi-process cache simulator (see \ref page_drcachesim),
   a last-level cache miss analyzer (see \ref page_drcachesim),
   and a legacy CPU testing tool (see \ref page_drcpusim).
   If this is a DynamoRIO public release, it also includes the
   Dr. Memory memory debugging tool (see \ref page_drmemory), a system call
   tracer for Windows (see \ref page_drstrace), a library tracing tool (see
   \ref page_drltrace), and a symbol querying tool (see \ref page_symquery).

When unpacking the release package on Windows, be aware that the Cygwin
unzip utility does not preserve executable permissions properly.  After
unzipping with Cygwin, add ugo+rx permissions to all of the .dll and .exe
files in the resulting directory tree:
\code
find . -name \*.dll -exec chmod ugo+rx {} \; -o -name \*.exe -exec chmod ugo+rx {} \;
\endcode

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\section sec_changes Changes Since Prior Releases

The current version is \DR_VERSION.  It includes Dr. Memory and the
Dr. Memory Framework (DRMF) in the same package as DynamoRIO.  DRMF
provides the umbra, drsyscall, and drsymcache Extensions for use by
clients.

The changes between version \DR_VERSION and 11.3.0 include the following compatibility
changes:
 - On 32-bit Arm the size of #dr_mcontext_t has been increased by 4 and the
   struct is now required to be 8-byte aligned. The offset of the field "simd"
   has changed.
 - Added new fields elf_path and elf_path_size to dr_memory_dump_spec_t. When
   dr_create_memory_dump() returns true and elf_path is not NULL, elf_path will be
   written with the path to the memory dump file.
 - Added new argument access_type of enum cache_access_type_t to the method
   access_update() of the classes dynamorio::drmemtrace::cache_replacement_policy_t and
   dynamorio::drmemtrace::caching_device_t. Possible values are:
   - cache_access_type_t::HIT,
   - cache_access_type_t::MISS.
 - Removed dynamorio::drmemtrace::reader_t::read_queued_entry(), which now does not
   require subclasses of #dynamorio::drmemtrace::reader_t to check for queued
   entries in their implementation of
   #dynamorio::drmemtrace::reader_t::read_next_entry().
 - Renamed eof_ to at_eof_ for #dynamorio::drmemtrace:record_reader_t, which must be
   set by subclasses of #dynamorio::drmemtrace:record_reader_t to indicate EOF.
 - Renamed cur_entry_ to entry_copy_ for subclasses of
   #dynamorio::drmemtrace:record_reader_t, which can be used instead to store the
   entry that is read from the trace file.
 - Changed signature of dynamorio::drmemtrace:record_reader_t::read_next_entry() to
   return a pointer to the read #dynamorio::drmemtrace:trace_entry_t instead of a bool.
 - Added a parameter to the constructor of #dynamorio::drmemtrace:reader_t and
   #dynamorio::drmemtrace:record_reader_t that indicates whether it is being used in
   the online or offline mode.
 - Moved the switch type enum from scheduler.h to trace_entry.h, now referenced as
   #dynamorio::drmemtrace::switch_type_t.
 - Added #drvector_t.config field which contains additional configuration parameters for
   a #drvector_t. It currently contains #drvector_config_t.zero_alloc that when set to
   true sets every entry pointer of the drvector's storage to 0 using memset().

The changes between version \DR_VERSION and 11.3.0 include the following minor
compatibility changes:

 - Added drmgr_register_exit_event(), drmgr_unregister_exit_event(),
   drmgr_register_exit_event_user_data(), and drmgr_unregister_exit_event_user_data(),
   which are required to be used instead of dr_register_exit_event() when using drmgr
   and provide priorities and user data to the exit event.
 - Added drmgr_register_filter_syscall_event(), drmgr_unregister_filter_syscall_event(),
   drmgr_register_filter_syscall_event_user_data(), and
   drmgr_unregister_filter_syscall_event_user_data(), which are required to be used
   instead of dr_register_filter_syscall_event() when using drmgr and provide
   priorities and user data to the filter event.
 - Added a separate cache replacement policy object to `caching_device_t`. `init` now
   takes an `std::unique_ptr<cache_replacement_policy_t>` that defines the replacement
   policy. It can be created manually or by using `create_cache_replacement_policy`.
   Removed the subclasses `cache_lru_t`, `cache_fifo_t`, `tlb_lfu_t`, `tlb_plru_t` that
   implemented specific cache replacement policies. Added implementations for the
   matching policies as subclasses of `cache_replacement_policy_t`.
 - Added the workload to the top bits of the tid for multi-workload drmemtrace
   scheduling.  The drmemtrace view tool now prints the workload and tid in
   the form "Wn.Tmmm".
 - Changed the #dynamorio::drmemtrace::scheduler_tmpl_t::input_thread_info_t.
   regions_of_interest structure layout, requiring recompiling using code.
 - Changed the #dynamorio::drmemtrace::analysis_tool_tmpl_t::process_memref and
   #dynamorio::drmemtrace::analysis_tool_tmpl_t::parallel_shard_memref return
   conditions to no longer indicate an error if the error string is empty.
   This can now be used to exit early without reporting an error.
 - Changed the -skip_refs drmemtrace option to not count markers, matching the
   -sim_refs and -warmup_refs options.  (The new -skip_records counts markers.)
 - Dropped support for -skip_refs and -sim_refs in the view tool (use the new
   -skip_records and -exit_after_records instead).
 - The post-attach event is now called in every injection/attach mode, and
   dr_register_post_attach_event() always returns true.
   A new API query dr_attached_midrun() is added to distinguish attach from
   launch injection to replace the return value of dr_register_post_attach_event().
 - Changed takeover of other threads at start time from a staggered takeover
   where each thread starts running as soon as it can to instead a synchronous
   takeover where all threads must be taken over before any can start
   executing.  The post-attach event becomes a safe spot for a snapshot of
   global properties while all threads are paused.  Setting -no_synchronous_attach
   switches to the old behavior, which may be needed for apps with a large number of
   threads that have some awareness of their slowdown and may construe it as a hang.
 - Added drmgr_register_post_attach_event(), drmgr_unregister_post_attach_event(),
   drmgr_register_post_attach_event_user_data(), and
   drmgr_unregister_post_attach_event_user_data(), which are required to be used
   instead of dr_register_post_attach_event() when using drmgr and provide
   priorities and user data to the post-attach event.
 - Added drmgr_register_pre_detach_event(), drmgr_unregister_pre_detach_event(),
   drmgr_register_pre_detach_event_user_data(), and
   drmgr_unregister_pre_detach_event_user_data(), which are required to be used
   instead of dr_register_pre_detach_event() when using drmgr and provide
   priorities and user data to the pre-detach event.
 - A C++17-supporting toolchain is now required to build.
 - The drmemtrace record type #dynamorio::drmemtrace::TRACE_TYPE_INSTR_NO_FETCH
   is no longer present in offline or online traces with the new drmemtrace
   trace version #dynamorio::drmemtrace::TRACE_ENTRY_VERSION_NO_UNFETCHED_INSTRUCTIONS.
   Instead, a repeated string loop will start with an instruction fetch of the new type
   #dynamorio::drmemtrace::TRACE_TYPE_INSTR_REPEATED, followed by consecutive
   load and store records.

Further non-compatibility-affecting changes include:
 - Changed the types of `block_size`, `total_size`, `num_blocks`, to `int64_t`
   in dynamorio::drmemtrace::caching_device_t and its deriving classes.
 - Added support for reading a single drmemtrace trace file from stdin
   via "-infile -".
 - Added the #dynamorio::drmemtrace::decode_cache_t library to make it easier and more
   efficient for drmemtrace analysis tools to obtain decoded information about
   instructions in the trace. This works for traces that have embedded instruction
   encodings in them, and also for legacy traces without embedded encodings where the
   encodings are obtained from the application binaries instead.
 - Added a new drmemtrace analyzer flag -sched_syscall_file to allow specifying the
   system call trace template file to be used for dynamic injection of system call trace
   templates. Added similar options for the drmemtrace scheduler: #dynamorio::drmemtrace::
   scheduler_tmpl_t::scheduler_options_t::kernel_syscall_trace_path, and #dynamorio::
   drmemtrace::scheduler_tmpl_t::scheduler_options_t::kernel_syscall_reader.
 - Added initial implementation of a noise generator in the drmemtrace framework. The
   noise generator produces synthetic records to schedule with one or more target traces.
   These synthetic records are interleaved with real trace records by the dynamic
   scheduler. We currently don't support mixing of noise and trace records in non-dynamic
   modes.
   To produce noise generation we implemented:
    - #dynamorio::drmemtrace::noise_generator_t scaffolding as a
      #dynamorio::drmemtrace::reader_t to produce synthetic trace records.
    - #dynamorio::drmemtrace::noise_generator_info_t, which contains the metadata
      information to drive the generation of synthetic records.
    - #dynamorio::drmemtrace::noise_generator_factory_t that creates
      #dynamorio::drmemtrace::noise_generator_t, which can then be added to the input
      workloads of #dynamorio::drmemtrace::scheduler_tmpl_t.
    - the flag -add_noise_generator to the drmemtrace framework that enables noise
      generation alongside the scheduled traces.
 - Added AUX_SUBDIR (== "aux") to the subdirs in which get_aux_file_path() looks for
   auxiliary files (e.g., v2p.textproto).
 - Added -memdump_on_window option to the drmemtrace trace analysis tools framework.
   This option triggers a memory dump when a trace window opens by -trace_after_instrs,
   -trace_instr_intervals_file, or -retrace_every_instrs. If -retrace_every_instrs is
   also enabled, a memory dump will be captured for each individual tracing window.
 - Added reg_is_avx512().
 - Added routine dr_invoke_syscall_as_app() to invoke a system call as though the
   application made it, meaning it goes through DR's handling.
 - Added drx_register_time_scaling() which scales timers on UNIX to align with
   the slowdown of heavyweight instrumentation.
 - Added a new drmemtrace option -exit_after_records which applies to all
   tools and exits after N records.
 - Added get_output_record_ordinal() to the drmemtrace scheduler.
 - Added a new drmemtrace option -skip_records which applies to all
   tools and skips the first N records.
 - Added -trim_before_instr and -trim_after_instr options to trim_filter (part of
   drmemtrace's record_filter). They allow the trimming of a trace using instruction
   ordinals. The trimming is approximated to the closest timestamp in the trace that
   follows the provided instuction ordinals, as timestamps are a safe spot to trim a
   trace.
 - Added a new library, drsyscall_record_lib, for reading and writing detailed syscall
   records. These records capture arguments, memory regions, and return codes. A new
   viewer, drsyscall_record_viewer, was also added to display the contents of these
   records.
 - Added the class dynamorio::drmemtrace::policy_rrip_t which implements RRIP cache
   replacement policy model for the drcachesim tool.
 - Added a new memtrace_stream_t::get_next_trace_pc() API for offline analysis and
   scheduling of non-i-filtered thread-sharded traces that returns the next continuous
   PC in the trace, which is from the next instruction or the next
   #dynamorio::drmemtrace::TRACE_MARKER_TYPE_KERNEL_EVENT marker, whichever comes
   first.
 - Added a new #hashtable_t iterator hashtable_apply_to_all_key_payload_pairs_user_data()
   that exposes the key of every element in the table.
 - Added a new DynamoRIO client "DrPoints" in clients/drpoints to compute the Basic Block
   Vectors of a program given a user-defined instruction interval.
 - Added a new drmemtrace option -exit_after_instrs which applies to all
   tools and exits after N instructions.
 - Added drvector_clear() API that clears a #drvector_t storage without deleting it.
 - Added #drvector_config_t that contains additional config parameters for a #drvector_t.
 - Added drvector_init_ex() API that initializes a #drvector_t with extra parameters
   defined in #drvector_config_t.
 - Added instr_get_isa_feature() which performs an encoding walk and returns the
   instruction ISA_FEAT_ constant.
 - Added instr_get_isa_feature_name() which returns the string name of an ISA_FEAT_
   constant.
 - Added -filter_kernel and -filter_kernel_except_syscalls to the drmemtrace
   analyzer that invokes #dynamorio::drmemtrace::kernel_filter_t to remove kernel
   content from a trace.
 - Changed the default for the drmemtrace -raw_compress option in statically linked
   clients from "none" to "lz4", when built against an lz4 with LZ4F_CustomMem support
   (lz4 >= 1.9.4).  lz4's allocations are routed through DR's private heap in that
   configuration.  Where that support is unavailable the static default remains "none".
 - On AArch64 the restriction that isb instructions must be the last instruction in a
   block has been lifted.
 - Added the -raw_compress_level option to drmemtrace to allow specifying the
   compression level for raw offline trace files when using lz4 compression.
 - Increased the default drmemtrace buffer size for the main (initial) thread
   by 8x. This also decreased the granularity of checking for the -trace_for_instrs
   and -exit_after_instrs flags; the old granularity can be reproduced by setting
   "-main_buf_records 4K".
 - On Linux, shared non-executable ELF module candidates are now validated against
   their executable load segments (i#8117).
 - Raised the maximum -vm_size on AArch64 from 2GB to 64GB.  A value larger
   than 2GB removes the code cache reachability guarantees described in
   \ref sec_64bit_reach.

**************************************************
<hr>

The changes between version 11.3.0 and 11.2.0 include the following compatibility
changes:
 - No compatibility changes yet.

Further non-compatibility-affecting changes include:
 - Added support for statically linking clients and the DynamoRIO library into
   a pure-static application via a new configure_DynamoRIO_static_client() CMake
   function and new "_drstatic" static library CMake targets for the provided
   extension libraries.
 - Allow v2p.textproto file in a trace directory. This file is present in public traces.
 - Allow v2p.textproto file to have one missing virtual_address field, which indicates
   virtual_address == 0x0. Necessary in case a trace accesses virtual address 0x0.

**************************************************
<hr>

The changes between version 11.2.0 and 11.1.0 include the following compatibility
changes:
 - Added #dynamorio::drmemtrace::TRACE_ENTRY_VERSION_RETIRED_INSTRUCTIONS_ONLY to
   increase the trace version for drmemtraces with uncompleted instructions removed.

Further non-compatibility-affecting changes include:
 - Added instr_get_operation_size() and instr_set_operation_size() APIs for
   #DR_ISA_REGDEPS #instr_t.

**************************************************
<hr>

The changes between version 11.1.0 and 11.0.0 include the following compatibility
changes:
 - Removed uncompleted instructions and the corresponding memrefs from drmemtraces.
   Instructions which are fetched but not completed due to asynchronous signal or
   fault are removed. A new marker
   #dynamorio::drmemtrace::TRACE_MARKER_TYPE_UNCOMPLETED_INSTRUCTION was added
   to indicate an uncompleted instruction was removed. The value of the marker
   is the encoding of the removed instruction up to a pointer's length.
   OFFLINE_FILE_VERSION_RETIRED_INSTRUCTIONS_ONLY was added by mistake and it was changed to
   #OFFLINE_FILE_VERSION_NO_OP.

 - Moved module file read logic into read_module_file() in raw2trace_shared, and
   removed raw2trace_directory_t::initialize_module_file() since the
   read_module_file() can be directly used without having to pull in the whole
   raw2trace_directory_t.

Further non-compatibility-affecting changes include:
 - Added X64 Linux support to dr_create_memory_dump(). This API has the same
   restriction as dr_suspend_all_other_threads_ex(). For X86_64 platform, the feature is
   supported only when fast FP save and restore is supported. And mixed mode is not
   supported.
 - Added the AArch64 FPMR register as DR_REG_FPMR.
 - Added OPSZ_addr which chooses the appropriate operand size on X86 from 2/4/8 based
   on the 32/64 bit mode and the presence or absence of the address size prefix.
 - Fixed the order of operands for the vpexpandd/vpexpandq opcodes (previously the
   source and destination operands were reversed).
 - Fixed the VEX-encoded forms of vaesdec/vaesdeclast/vaesenc/vaesenclast/vpclmulqdq
   to obey VEX.L, which they previously ignored.

**************************************************
<hr>

The changes between version 11.0.0 and 10.0.0 include the following compatibility
changes:
 - Marked x86 rep instructions as predicated.
 - The #dr_instr_category_t enum underwent changes to support new categories
   such as STATE, MOVE, CONVERT, and MATH.
   INT_MATH has been removed and replaced with MATH.
   FP_MATH has been removed and replaced with FP|MATH.
   The enumeration was organized in a different order, the old numbers become invalid
 - The #dynamorio::drmemtrace::TRACE_MARKER_TYPE_FUNC_RETVAL marker for system
   calls changed to contain the actual return value, rather than just whether
   successful.  A new marker #dynamorio::drmemtrace::TRACE_MARKER_TYPE_SYSCALL_FAILED
   was added to indicate failure.
 - Changed the enum value of #dynamorio::drmemtrace::scheduler_t::DEPENDENCY_TIMESTAMPS
   to include direct switch dependencies.  This is not a binary compatibility change
   as the old value still refers purely to timestamps, but on a recompile it
   refers to timestamps and direct switches, which is what most users should want.
 - Rename the macro INSTR_CREATE_mul_sve to INSTR_CREATE_mul_sve_imm to
   differentiate it from the other SVE MUL instructions.
 - Renamed a protected data member in #dynamorio::drmemtrace::analyzer_tmpl_t from
   merged_interval_snapshots_ to whole_trace_interval_snapshots_ (may be relevant for
   users sub-classing analyzer_tmpl_t).
 - Converted #dynamorio::drmemtrace::analysis_tool_tmpl_t::interval_state_snapshot_t
   into a class with all its data members marked private with public accessor functions.
 - Changed the type of the AArch64 #dr_mcontext_t members svep and ffr to #dr_svep_t.
   This breaks binary compatibility with clients that were built against versions of
   DynamoRIO before this change.
 - Changed #dynamorio::drmemtrace::record_filter_t::record_filter_func_t
   parallel_shard_filter() interface.  Added a new parameter of type
   #dynamorio::drmemtrace::record_filter_t::record_filter_info_t that allows
   #dynamorio::drmemtrace::record_filter_t to share data with its filters.
 - Changed the way we cache the feature register values on AArch64. We now use an array of
   uint64 values rather than individual variables for each feature register. This
   allows the code to be more readable and easier to maintain.
 - Renamed dr_set_sve_vector_length() to dr_set_vector_length() to share function
   signature between AArch64 and RISC-V.
 - Renamed dr_get_sve_vector_length() to dr_get_vector_length() to share function
   signature between AArch64 and RISC-V.
 - Changed the drcachesim -LL_miss_file option by adding a process ID field to the output.
   This helps in better analyzing cache misses in multi-process environments.

Further non-compatibility-affecting changes include:
 - Added DWARF-5 support to the drsyms library by linking in 4 static libraries
   from elfutils.  These libraries have LGPL licenses.
 - Added raw2trace support to inject system call kernel trace templates collected from
   elsewhere (e.g., QEMU, Gem5) into the user-space drmemtrace traces at the
   corresponding system call number marker. This is done by specifying the path to the
   template file via the new -syscall_template_file option.
 - Added a new scheme for the modoffs field in the PC trace entry which allows L0
   filtering of non-module code; see
   #dynamorio::drmemtrace::ENCODING_FILE_TYPE_SEPARATE_NON_MOD_INSTRS. Also added
   file type entry to the header of encoding files.
 - Fixed a bug in the AArch64 codec with the way that SVE scalar+immediate predicated
   contiguous load and store instructions represented the immediate offset in the IR.
   In 10.0.0 the memory operand in these instruction used the immediate value from the
   instruction (which is an index to be scaled by the vector length) as the displacement,
   whereas the displacement value in a DynamoRIO memory operand should always be a byte
   offset. This has now been corrected.
   Traces and other tool results created with DynamoRIO prior to this fix may have
   incorrect results if the application contained these instructions.
   See <a href="https://github.com/DynamoRIO/dynamorio/pull/6390">PR #6390</a> for the
   full list of affected instructions.
 - Added core-sharded analysis tool support where traces are sharded by
   core instead of by thread, with the thread schedules onto the cores
   either following how they were traced or using a dynamic schedule.
   Adds #dynamorio::drmemtrace::shard_type_t passed to initialize_shard_type()
   to inform tools of the shard type.
   Adds a new memtrace_stream_t::get_output_cpuid() query.
   Adds a number of drcachesim options to set sharding mode (-core_sharding,
   -core_serial) and control the schedule
   (-sched_quantum, -sched_time, sched_order_time, -record_file,
   -replay_file, -cpu_schedule_file).
 - Added additional timestamps to drmemtrace traces: at the end of each buffer,
   and before and after each system call.
 - Added type_is_read() API that returns true if a trace type reads from memory.
 - Added instr_num_memory_read_access() and instr_num_memory_write_access() that return
   the number of memory read and write accesses of an instruction respectively.
 - Added realloc to the set of functions traced by -record_heap by default.
 - Deprecated #dr_fp_type_t for Floating-Point operation types in favor of the new
   #dr_instr_category_t.
   Deprecated instr_is_floating_ex(), replacing it with instr_is_floating_type().
   The old versions will continue to work.
 - Added several routines to the #dynamorio::drmemtrace::memtrace_stream_t interface
   for drmemtrace analysis tools: get_output_cpuid(), get_workload_id(),
   get_input_id(), get_input_interface().
 - Added -record_syscall to drmemtrace for recording syscall parameters.
 - Added opportunity to run multiple drcachesim analysis tools simultaneously.
 - Added support of loading separately-built analysis tools to drcachesim dynamically.
 - Added instr_is_opnd_store_source().
 - Added kernel context switch sequence injection support to the drmemtrace scheduler.
 - Added dr_running_under_dynamorio().
 - Added instr_get_category_name() API that returns the string version (as char*) of a
   category.
 - Added #dynamorio::drmemtrace::TRACE_MARKER_TYPE_VECTOR_LENGTH marker to indicate the
   current vector length for architectures with a hardware defined or runtime changeable
   vector length (such as AArch64's SVE scalable vectors).
 - Added a new drmemtrace analyzer option \p -interval_instr_count that enables trace
   analyzer interval results for every given count of instrs in each shard. This mode
   does not support merging the shard interval snapshots to output the whole-trace
   interval snapshots. Instead, the print_interval_results() API is called separately
   for each shard with the interval state snapshots of that shard.
 - Added a new finalize_interval_snapshots() API to
   #dynamorio::drmemtrace::analysis_tool_t to allow the tool to make holistic
   adjustments to the interval snapshots after all have been generated, and before
   they are used for merging across shards (potentially), and printing the results.
 - Added opnd_is_vector_base_disp() to test if an opnd_t is a base+disp memory operand
   that uses a vector register for the base or index register.
 - Added -abort_on_invariant_error flag that instructs the invariant checker drmemtrace
   analysis tool to abort trace analysis when a trace invariant error is found. This
   is set to true by default to match the existing behavior of the invariant checker.
 - Added a new instr API instr_is_xrstor() that tells whether an instruction is any
   variant of the x86 xrstor opcode.
 - Added a new #dr_isa_mode_t: #DR_ISA_REGDEPS, which is a synthetic ISA with the main
   purpose of preserving register dependencies.
 - Added instr_convert_to_isa_regdeps() API that converts an #instr_t from a real ISA
   (e.g., #DR_ISA_AMD64) to the #DR_ISA_REGDEPS synthetic ISA.
 - Added encodings2regdeps_filter_t filter to #dynamorio::drmemtrace::record_filter_t to
   generate #DR_ISA_REGDEPS traces.
 - Added #dynamorio::drmemtrace::OFFLINE_FILE_TYPE_ARCH_REGDEPS file type for
   #DR_ISA_REGDEPS traces.
 - Added -tool as the preferred alias for -simulator_type for the drmemtrace/drcachesim
   trace analysis tool framework.
 - Added "-t drmemtrace" as the preferred launcher for the drmemtrace/drcachesim
   trace analysis tool framework.
 - Added func_id_filter_t to #dynamorio::drmemtrace::record_filter_t to filter function
   markers based on the function ID. This filter is enabled by "-filter_keep_func_ids"
   followed by a comma-separated list of function IDs to preserve in the output trace.
   All function markers whose ID is not in the list are removed.
 - Added -skip_to_timestamp and #dynamorio::drmemtrace::scheduler_tmpl_t::
   input_workload_t::times_of_interest to the drmemtrace scheduler.
 - Added v2p_reader_t to parse a virtual-to-physical mapping in textproto format and
   v2p_info_t to hold that mapping in memory.
 - Added -v2p_file option to drcachesim TLB tool to set the path to a v2p.textproto file,
   which provides a virtual to physical mapping of addresses for an offline trace. This
   option overwrites both -page_size and
   #dynamorio::drmemtrace::TRACE_MARKER_TYPE_PAGE_SIZE (if present) with the page size in
   v2p.textproto. Option -use_physical (in offline mode) must also be set to use the
   mapping in v2p.textproto (note that -use_physical during tracing is not necessary, nor
   related to -use_physical offline).
 - Added -trace_instr_intervals_file option to the drmemtrace trace analysis tools
   framework. The file must be in CSV format containing a <start,duration> tracing
   interval per line where start and duration are expressed in number of instructions.
 - Added modify_marker_value_filter_t to #dynamorio::drmemtrace::record_filter_t to modify
   the value of TRACE_MARKER_TYPE_ markers. This filter takes a list of
   <TRACE_MARKER_TYPE_,new_value> and changes every listed marker in the trace to its
   corresponding new_value.
 - Added trace_analysis_tool::preferred_shard_type() to the drmemtrace framework to
   allow switching to core-sharded by default if all tools prefer that mode.
 - For the drmemtrace framework, if only core-sharded-preferring tools are enabled
   (these include cache and TLB simulators and the schedule_stats tool), -core_sharded or
   -core_serial is automatically turned on for offline analysis to enable more
   representative simulated software thread scheduling onto virtual cores.

**************************************************
<hr>

The changes between version 10.0.0 and 9.0.1 include the following compatibility
changes:
 - Eliminated the -skip_syscall option to drrun and drinject, which is now always
   on by default.
 - Changed the drcachesim -use_physical option to not modify the regular trace
   entry virtual addresses but to instead insert metadata containing translation
   information for converting virtual to physical addresses.
 - Changed the layout of the DR_FAST_IR struct to add an element size property
   that supports more information about vectors. This changes the method of accessing
   the register in the structure from struct.value.reg to
   struct.value.reg_and_element_size.reg. The element size can be accessed directly
   via struct.value.reg_and_element_size.element_size.
 - Changed the size of the #instr_t structure by appending a field which is used
   for relative offsets while encoding.  The note field is no longer modified
   during encoding.
 - Reduced the value of #DR_NOTE_FIRST_RESERVED.  This is not expected to cause
   problems unless clients are directly choosing high note values without using
   drmgr_reserve_note_range().
 - Changed the values of the AArch64 DR_REG_Z* constants so that Z registers can be
   used in base+disp operands in SVE scatter/gather instructions. This breaks binary
   compatibility for clients built against an older version of opnd_api.h, but source
   code compatibility is unchanged.
 - Removed the drcachesim external iterator analyzer interface.  Users should instead
   use the new #dynamorio::drmemtrace::scheduler_tmpl_t interface for direct control
   over iteration.  See \ref sec_drcachesim_sched for example code.
 - Refactored the drmemtrace reader and file reader classes to better fit the
   new scheduler model: now each reader owns just one single stream of records
   with all multi-stream interleaving owned by the scheduler.
 - Replaced the AArch64 OP_reta with OP_retaa and OP_retab. "reta" is not a real
   AArch64 instruction and "reta" entries in the AArch64 codec were being used to
   decode "retaa" and "retab". These instructions will now encode and decode correctly
   as "retaa" and "retab".
 - Added a #DR_XFER_RSEQ_ABORT event for a signal generated during an rseq region.
 - Changed the interrupted PC for #DR_XFER_RSEQ_ABORT for native execution aborts to be
   the abort handler (a signal during the instrumented execution will continue to have
   the actual interrupted PC); changed the interrupted PC for #DR_XFER_SIGNAL_DELIVERY
   for a signal generated during an rseq region to be the abort handler, matching the
   kernel behavior.
 - Changed the arguments and decode behavior of the INSTR_CREATE_orr_sve_pred(),
   INSTR_CREATE_eor_sve_pred(), INSTR_CREATE_and_sve_pred() and
   INSTR_CREATE_bic_sve_pred() to use the new vector element registers and to
   correctly encode the predicate mode.
 - ud2a and ud2b have been renamed to ud2 and ud1, respectively. The old constants
   #OP_ud2a and #OP_ud2b, as well as the #INSTR_CREATE_ud2a()/#INSTR_CREATE_ud2b()
   macros, are \#defined to the new names, #OP_ud2, #OP_ud1, #INSTR_CREATE_ud2(),
   and #INSTR_CREATE_ud1() respectively. ud1 now correctly accounts for its operands
   so manipulation of ud1 is not backwards compatible.
 - All drcachesim/ code was changed to use the dynamorio::drmemtrace namespace.
   External code using any drcachesim or drmemtrace library will need to be
   recompiled.
 - The droption header library is now inside the dynamorio::droption namespace.
 - The drmemtrace record type #dynamorio::drmemtrace::TRACE_TYPE_INSTR_CONDITIONAL_JUMP
   is deprecated in offline traces where it is replaced by
   #dynamorio::drmemtrace::TRACE_TYPE_INSTR_TAKEN_JUMP and
   #dynamorio::drmemtrace::TRACE_TYPE_INSTR_UNTAKEN_JUMP.
 - All int_least64_t and uint_least64_t types in drcachesim were replaced with
   their precise counterparts int64_t and uint64_t.
 - The #dynamorio::drmemtrace::memref_t structure has a new field appended for
   holding the actual target of each indirect branch.
 - Increased the size of dr_simd_t to accommodate AArch64's Scalable Vector
   Extension (SVE) as well as adding two new dr_simd_t instances to
   #dr_mcontext_t: SVE predicate registers svep[] and the SVE first-fault
   register, ffr. This is a significant binary compatibility change and will
   require re-building clients built before SVE was added.
 - The #instr_t structure has a new field inserted for holding the category type
   #dr_instr_category_t which changes the size and the offsets of most fields
   in 32-bit.  64-bit compatibility is not affected.

Further non-compatibility-affecting changes include:
 - Added new drmemtrace option -L0_filter_until_instrs which enables filtering
   for the specified instruction count before switching to full instruction tracing.
   Such bimodal filtered traces have #dynamorio::drmemtrace::OFFLINE_FILE_TYPE_BIMODAL_FILTERED_WARMUP
   in their file type, and a #dynamorio::drmemtrace::TRACE_MARKER_TYPE_FILTER_ENDPOINT marker
   at the point in the trace when filtering ended.
 - Added AArchXX support for attaching to a running process.
 - Added new fields analyze_case_ex and instrument_instr_ex to #drbbdup_options_t.
 - Added drbbdup support to drwrap via #DRWRAP_INVERT_CONTROL, drwrap_invoke_insert(),
   and drwrap_invoke_insert_cleanup_only().
 - Added -trace_for_instrs and -retrace_every_instrs options to drcachesim
   for periodic trace bustrs of an unmodified application.
 - Added compression of drmemtrace raw offline files with various compression
   choices under the -raw_compress option.  Compressing with lz4 is now the
   default (if built with lz4 support).
 - Added drmodtrack_lookup_pc_from_index().
 - Added -use_physical support to drcachesim offline traces using three new
   marker types: #dynamorio::drmemtrace::TRACE_MARKER_TYPE_PHYSICAL_ADDRESS,
   #dynamorio::drmemtrace::TRACE_MARKER_TYPE_VIRTUAL_ADDRESS, and
   #dynamorio::drmemtrace::TRACE_MARKER_TYPE_PHYSICAL_ADDRESS_NOT_AVAILABLE.
 - Added an open-address hashtable implementation for cases where third-party
   libraries must be avoided and open addressing is best: dr_hashtable_create(),
   dr_hashtable_destroy(), dr_hashtable_clear(), dr_hashtable_lookup(),
   dr_hashtable_add(), dr_hashtable_remove().
 - Added a new #dynamorio::drmemtrace::TRACE_MARKER_TYPE_PAGE_SIZE record to drcachesim offline traces.
 - Added new drmemtrace options -L0I_filter and -L0D_filter that allow enabling
   online filtering for only instruction or only data entries respectively. The
   old option -L0_filter is deprecated but still supported for backward
   compatibility. It simply sets both the new options.
 - Added a new DR extension, namely "drpttracer", which provides clients with tracing
   functionality via Intel's PT instruction tracing feature. This feature is still
   experimental and available only on Intel processors.
 - Added a new drmemtrace option -enable_kernel_tracing that allows recording each
   syscall's Kernel PT and writes every syscall's PT and metadata to files in
   -outdir/kernel.raw/ for later offline analysis. This feature is still experimental
   and available only on Intel processors that support the Intel@ Processor Trace
   feature.
 - Added drmemtrace_get_encoding_path().
 - Added preliminary support for generated code to drmemtrace.
 - Changed the default drmemtrace offline file format from .gz to .zip and
   added the option -chunk_instr_count to control the split of a file within
   the .zip, which sets the granularity of a fast seek.
 - Added dr_register_post_attach_event(), dr_unregister_post_attach_event(),
   dr_register_pre_detach_event(), and dr_unregister_pre_detach_event().
 - Added instruction encodings to drmemtrace offline traces.
 - Added drmemtrace_replace_file_ops_ex().
 - Added -align_endpoints to drmemtrace to avoid uneven attach/detach periods.
 - Added a method of representing vector registers with element sizes.
   They can be created with opnd_create_reg_element_vector(), detected with
   opnd_is_element_vector_reg() and have their element size retrieved by
   opnd_get_vector_element_size().
 - Deprecated the drmemtrace analysis tool functions initialize() and
   parallel_shard_init(), replacing them with initialize_stream() and
   parallel_shard_init_stream().  The old versions will continue to work.
   The stream interface passed to analysis tools provides tools with the
   record and instruction ordinals along with the values of top-level
   headers.
 - Added #dynamorio::drmemtrace::record_analyzer_t and #dynamorio::drmemtrace::record_analysis_tool_t for analyzing the
   sequence of #dynamorio::drmemtrace::trace_entry_t exactly as present in a stored offline trace.
 - Added opnd_size_to_shift_amount() and opnd_create_base_disp_shift_aarch64()
   for explicitly specifying shift amounts in the creation of operands for
   AArch64 memory addresses.
 - Added opnd_create_increment_reg() to create a register from an existing
   register whose register number is incremented by some amount, wrapping
   at the max register number for that register.
 - Added opnd_create_vector_base_disp_aarch64() and reg_is_z() for creating
   memory address operands that use SVE Z registers with a specified element
   size.
 - Added a new #dynamorio::drmemtrace::scheduler_tmpl_t interface providing scheduling
   of drmemtrace offline files onto configurable output streams, meant for use by
   microarchitectural simulators.
 - Added a #dynamorio::drmemtrace::memtrace_stream_t interface for drmemtrace analysis tools to
   query key attributes of each input trace.
 - Added instr_create_1dst_6src() convenience function that returns an instr_t
   with one destination and six sources.
 - Added a new label to help in handling "rseq" (Linux restartable sequence) regions:
   #DR_NOTE_RSEQ_ENTRY.
 - Added instr_get_offset() API for getting the offset of an instr in an instrlist that
   has been encoded with instrlist_encode* set of APIs.
 - Added a new drmemtrace analyzer option \p -interval_microseconds and various new
   #dynamorio::drmemtrace::analysis_tool_t APIs for producing per-interval results. The analyzer framework
   invokes the generate_interval_snapshot() and generate_shard_interval_snapshot()
   analysis tool APIs periodically every \p -interval_microseconds of the trace as
   measured by the #dynamorio::drmemtrace::TRACE_MARKER_TYPE_TIMESTAMP marker values. In these callbacks, the
   tool creates and returns a snapshot of their internal state that is required to
   produce and print per-interval results in a later print_interval_results() call.
   The tool's internal state is a struct derived from the
   #dynamorio::drmemtrace::analysis_tool_tmpl_t::interval_state_snapshot_t base struct. Additionally, the tool
   implements combine_interval_snapshot() to combine two interval snapshot structs,
   which is required for producing whole-trace results in the parallel mode of analyzer
   operation, and also release_interval_snapshot() which is used to release the
   analyzer framework's claim to the interval snapshot objects.
 - Added a new drmemtrace analysis tool: syscall_mix, to count frequency of system
   calls in a trace. This tool works in both the online and offline modes of
   drmemtrace.
 - Added proc_get_vector_length_bytes() for AArch64. This returns the current
   vector length on all ARMv8 hardware including hardware which supports the
   Scalable Vector Extension (SVE).

**************************************************
<hr>

The changes between version 9.0.1 and 9.0.0 include the following compatibility
changes:
 - Introduced a new CMake option called BUILD_PACKAGE to skip glibc
   compatibility checks. This is off by default such that building DynamoRIO
   from source is straight-forward to do on rolling release Linux
   distributions, and enabled by make/package.cmake when building a
   distributable version of DynamoRIO.

Further non-compatibility-affecting changes include:
 - Fixed a significant performance regression between 8.0.0 and 9.0.0
   (between 8.0.18740 and 8.0.18747) affecting Windows programs with
   varying indirect branches on hot code paths.
 - Added alias support to droption.
 - The drcpusim option -blacklist was renamed to -blocklist but the old name
   is still accepted.
 - Added droption_parser_t::clear_values() for re-setting accumulating option
   values on re-attach for statically linked clients.
 - Added the count of cache exits to #dr_stats_t.
 - Added dr_register_inject_paths() and a corresponding -use_alt_dll drrun/drconfig
   parameter for control over DynamoRIO library paths, in particular the other
   bitwidth path, when configuring target processes.
 - Added -tool_dir drrun/drconfig parameter to control where to look for tool
   config files.

**************************************************
<hr>

The changes between version 9.0.0 and 8.0.0 include the following compatibility
changes:

 - The AArch64 opcode enum ordering changed.
 - A source compatibilty change in drcachesim analysis tools for users
   who have created derived classes from existing analysis tools:
   member fields of classes are now following a consistent style with
   an underscore suffix.  References to renamed fields will need to be
   updated.
 - A change in the load callbacks used with drmodtrack_add_custom_data()
   and drmemtrace_custom_module_data(): they each take an additional parameter, the
   segment index.  The custom data field is now per-segment and not per-module,
   and all callbacks are invoked separately for each segment.

The changes between version 9.0.0 and 8.0.0 include the following minor
compatibility changes:

 - drconfiglib (and thus drrun and drconfig) now sets only the new client path
   options which are added in this release to support other-bitwidth child processes.
   This means that a drconfiglib from this version will not properly configure for a
   DynamoRIO core library from a prior version.
 - A new option -ldstex2cas is on by default on ARM and AArch64.  This converts
   load-exclusive store-exclusive sequences to use compare-and-swap instead,
   which enables normal instrumentation of such sequences without clearing
   the exclusive monitor and causing infinite loops.  However, the compare-
   and-swap's semantics are not identical: it does not detect "ABA" changes and
   could cause errors in lock-free data structures or other application constructs.
   See \ref sec_ldrex for more information.
 - The header file dr_tools.h has been split up, with module information now in a new
   file dr_modules.h, os-specific queries in dr_os_api.h, and tracedump types in
   dr_tracedump.h.  dr_api.h includes the new files, so users including dr_api.h are
   unaffected.
 - The header files dr_ir_utils.h, dr_ir_opnd.h, dr_ir_instr.h, and dr_ir_instrlist.h
   have been split up, with encoding routines now in a new file dr_ir_encode.h,
   decoding routines in dr_ir_decode.h, disassembly routines in dr_ir_disassemble.h.
   dr_api.h includes the new files, so users including dr_api.h are unaffected.
 - The routines dr_insert_save_fpstate(), dr_insert_restore_fpstate(),
   and dr_insert_get_seg_base() moved from dr_proc.h to dr_ir_utils.h.
 - Added a flags field to #emulated_instr_t and two emulator-set flags values:
   #DR_EMULATE_REST_OF_BLOCK, indicating an emulation sequence that has no end label
   and includes the rest of the block; and #DR_EMULATE_INSTR_ONLY, indicating
   an emulation for which instrumentation should still examine the
   emulation sequence for observing data operations.  A third value is set by
   drmgr_in_emulation_region(): #DR_EMULATE_IS_FIRST_INSTR.  This flag addition preserves
   binary compatibility, but source code that did not zero the structure could end
   up with an uninitialized flags field when calling drmgr_insert_emulation_start().
 - drcov's output now uses a module segment offset, rather than a module base offset.
   This better supports modules with code beyond the first segment and with
   gaps between segments.
 - Changed the drcachesim view tool's behavior to count all trace entries, rather
   than just instructions, with respect to the -skip_refs and -sim_refs flags.
   This matches the cache and TLB simulator behavior.
 - drcachesim's child cache statistics now include hits from all lower levels and
   not just the immediately lower level child caches.
 - For AArch64 the OP_sys opcode is still implemented but has been split up
   into its data and instruction cache opcodes. In cases where OP_sys was used
   with enums representing data and instruction cache opcodes, OP_sys is no
   longer used, replaced by the relevant data and instruction cache opcodes
   starting with OP_dc_ and OP_ic_, e.g. OP_ic_ivau, OP_dc_zva.

Further non-compatibility-affecting changes include:

 - On x86 Windows, different-bitwidth child processes are now followed into.
   The default injection method has also changed to a new method relying on
   an image entry hook in some cases.  The old behavior can be requested by
   passing "-late" to drrun or calling dr_inject_use_late_injection().
 - Added drmgr_register_opcode_instrumentation_event() and
   drmgr_unregister_opcode_instrumentation_event() so that drmgr supports
   opcode event instrumentation.
 - Added dr_num_app_args(), dr_get_app_args() and dr_app_arg_as_cstring() to
   enable the gathering of application command-line args. Currently, implemented
   for Unix systems only.
 - Added dr_get_error_code() to obtain the error code of the last failed API routine.
   Not all API routines support the setting of error codes. Please look at their
   documentation to check if they do.
 - Added -instr_only_trace option to drcachesim.
 - Added other-bitwidth child process support, with the other client library
   specified by "-c32" "-c64" to drrun or drdeploy, by dr_register_client_ex()
   with #dr_config_client_t.is_alt_bitwidth=true to drconfiglib, and by
   CLIENT{32,64}_{ABS,REL} in tool files.
   Added dr_get_client_info_ex() and dr_client_iterator_next_ex() to support
   querying other-bitwidth client registration.
 - Added a new drcachesim option \p -max_global_trace_refs for specifying a global
   trace size limit that does not terminate the process.
 - Added opnd_create_immed_double(), opnd_get_immed_double() and
   opnd_is_immed_double() to enable the creation and handling of double
   precision floating-point operands.
 - Added dr_flush_region_ex API that accepts a callback to be executed after synch
   flush but before the threads are resumed. The existing dr_flush_region API
   is modified to invoke dr_flush_region_ex with a NULL callback.
 - Added instr_is_exclusive_load().
 - Added XINST_CREATE_store_pair() and XINST_CREATE_load_pair().
 - Added instr_replace_reg_resize() and opnd_replace_reg_resize().
 - Added #DRX_COUNTER_REL_ACQ flag to optionally enable release-acquire semantics for
   drx_insert_counter_update() on AArchXX.
 - Added a preferred base field to the #_module_data_t struct and to the
   #_drmodtrack_info_t struct.
 - Added support for running under QEMU via the \ref op_xarch_root "-xarch_root"
   runtime option which locates guest system libraries and enables workarounds for
   problems with QEMU's threads.
 - Added dr_is_detaching(), an API to query whether detach is in progress.
 - Added instr_zeroes_zmmh() that returns true if an instruction clears the
   upper bits of a ZMM register with zeros.
 - Added instr_clear_label_callback().
 - Added #DRREG_HANDLE_MULTI_PHASE_SLOT_RESERVATIONS to #drreg_bb_properties_t to
   enable logic that avoids conflicts in spill slots when drreg is used to reserve
   registers in multiple phases.
 - Added drmgr_in_emulation_region(), drmgr_orig_app_instr_for_fetch(), and
   drmgr_orig_app_instr_for_operands() for more conveniently handling emulation.
 - Added the reconstructed #instrlist_t when available for the faulting fragment
   to #dr_fault_fragment_info_t. This makes it available to the restore state
   event callback(s) via the #dr_restore_state_info_t arg.
 - Added the source context for restartable sequence aborts (#DR_XFER_RSEQ_ABORT)
   which was previously missing.
 - Added a #dynamorio::drmemtrace::TRACE_MARKER_TYPE_VERSION entry to drmemtrace traces.
 - Augmented drmemtrace #dynamorio::drmemtrace::TRACE_MARKER_TYPE_KERNEL_EVENT entries with the absolute
   PC of the interruption point, including for restartable sequence aborts, which
   now also have an additional #dynamorio::drmemtrace::TRACE_MARKER_TYPE_RSEQ_ABORT identifier.
 - Added a fifth instrumentation phase (meta_instru) that executes after the
   insertion of instrumentation and instrumentation optimizations. Its primary purpose
   is to enable debugging of instrumentation sequences and detection of
   instrumentation-induced bugs.
 - Added \p drstatecmp Extension which provides mechanisms to enable systematic
   and exhaustive machine state comparisons across instrumentation sequences.
 - Added drmodtrack_lookup_segment().
 - Added a new drrun option \p -attach for attaching to a running process.
   This is currently an experimental option and is not yet as well-supported
   as launching a new process.  It is only supported on x86 at this time.
 - Added \ref page_drcallstack Extension for walking application callstacks, with
   an initial Linux-only implementation.
 - Added new #dr_cleancall_save_t flags which are required for proper interaction
   between clean calls and drreg: #DR_CLEANCALL_READS_APP_CONTEXT must be set for
   dr_get_mcontext() to obtain the proper values, and #DR_CLEANCALL_WRITES_APP_CONTEXT
   must be set to ensure that dr_set_mcontext() is persistent.
   If the call may be skipped by tool-inserted control flow, #DR_CLEANCALL_MULTIPATH
   must additionally be set.
 - Added a new event dr_register_clean_call_insertion_event(), meant for use by
   register management libraries.
 - Added drreg_statelessly_restore_all().
 - Completed drx_expand_scatter_gather() support for emulating x86 scatter/gather
   instructions using a sequence of scalar stores/loads. The scalar store/load
   sequence makes it easier for clients to instrument each memory access.

**************************************************
<hr>

Version 8.0.0 includes Dr. Memory and the
Dr. Memory Framework (DRMF) in the same package as DynamoRIO.  DRMF
provides the umbra, drsyscall, and drsymcache Extensions for use by
clients.

The changes between version 8.0.0 and 7.1.0 include the following compatibility
changes:

 - Changed the enumeration of the DR_REG_ enum by adding x86 AVX-512 registers as well
   as reserved ranges for future extensions.
   This is a binary compatibility change for the DR_REG_ enum.
 - Changed the enumeration of the OPSZ_ enum by moving its start back to 0. The OPSZ_
   enum now completely overlaps the DR_REG_ enum.
   This is a binary compatibility change for the OPSZ_ enum.
 - Added a new encoding hint field to #instr_t.
 - Added a requirement that a C++11-compliant compiler be used with \ref page_droption.
 - Changed the syntax of the drcachesim -record_function option.  It no longer takes
   in an identifier: the identifier is computed by the tracer.  It thus takes pairs,
   with an optional third argument for flags such as "noret" to indicate that the
   return value should not be recorded.
   The tracer writes out a file listing functions traced and their identifiers
   with "id,library!symbol" on each line of the file.
 - Added free_key_func to the drcontainers hashtable_configure(), which adds a field
   to #hashtable_config_t.  Binary compatibility is maintained via the size field
   of the struct, but users who were not zeroing the whole structure and who update
   and recompile without setting the field may see crashes due to
   free_key_func being uninitialized.
 - Changed the 32-bit x86 stack alignment of DynamoRIO and clients built using
   DR's CMake configuration from 4 to 16 on Linux to match modern conventions.

The changes between version 8.0.0 and 7.1.0 include the following minor
compatibility changes:

 - Added the define #MCXT_NUM_SIMD_SLOTS that was renamed from NUM_SIMD_SLOTS.
   #MCXT_NUM_SIMD_SLOTS is now a constant that shall be used only to determine
   the number of SIMD slots in DynamoRIO's mcontext.
 - Replaced NUM_SIMD_SLOTS with proc_num_simd_saved().
   Clients may set(DynamoRIO_NUM_SIMD_SLOTS_COMPATIBILITY ON) in order to provide
   the define NUM_SIMD_SLOTS using proc_num_simd_saved(). The macro is not a constant
   expression and code relying on this needs to be rewritten.
   DynamoRIO_NUM_SIMD_SLOTS_COMPATIBILITY is set automatically if clients target
   version 7.1.0 or earlier.
 - Renamed mcontext's "ymm" structure to "simd".
 - Deprecated reg_is_xmm() and reg_is_ymm().
 - The function reg_is_extended() now returns true for the upper 8 simd registers
   as part of AVX-512, e.g. xmm16 - xmm31.
 - Dropped support for clients used with statically linked DynamoRIO to reach
   the code cache with 32-bit displacements.
 - An additional parameter in the accessors to the drcachesim cache stats
   (namely cache_stats_t and caching_device_stats_t) that passes a pointer to
   the cache block being accessed (on a hit) or being replaced (on a miss).
   This allows users to extend the cache block and stats classes in order to
   collect more stats.
 - Moves the immediate operand of the VEX encoded version of vextractps and vinsertps
   to be the first source.
 - The GPR versions of the vmovd and vmovq AVX opcodes are no longer combined into a
   single vmovd.
 - Changed the #PFX format string specifier to use %p rather than %x internally.
 - DR no longer forwards _snprintf, _snwprintf, _vsnprintf, sprintf, or sscanf to
   ntdll.  Clients should use the dr_-prefixed versions of these functions.
 - PC-relative control transfer instructions are now auto-re-relativized by the
   general decoder and encoder.  This affects clients and standalone tools that use
   decode_from_copy() or instr_encode_to_copy() or instrlist_encode_to_copy().
   Previously, re-relativization for instruction references only happened when an
   instruction was re-encoded.  This auto-PC-relativization can be avoided by calling
   instr_set_rip_rel_valid() and setting the validity of the PC-relative data to false.
 - Fixed major synchronization bugs on ARM and AArch64.

Further non-compatibility-affecting changes include:

 - Added the function proc_num_simd_registers().
 - Added drfront_set_verbose() to obtain diagnostics from drfrontendlib.
 - Added new fields to #dr_os_version_info_t which contain the build number,
   edition, and Windows 10 release identifier.
 - Added the function instr_is_xsave().
 - Added the type #dr_zmm_t.
 - Added the type #dr_opmask_t.
 - Added the define #MCXT_NUM_OPMASK_SLOTS for the number of AVX-512 OpMask registers.
 - Renamed mcontext's ymm structure into simd.
 - Added a new option -logprefix to drcov.
 - Added the AVX-512 registers #DR_REG_XMM16 - #DR_REG_XMM31, #DR_REG_YMM16 -
   #DR_REG_YMM31 and their #DR_REG_ZMM0 - #DR_REG_ZMM31 siblings as well as
   #DR_REG_K0 - #DR_REG_K7.
 - Added the function reg_is_opmask().
 - Added the functions reg_is_strictly_xmm(), reg_is_strictly_ymm() and
   reg_is_strictly_zmm().
 - Added the function reg_is_avx512_extended().
 - Added the function instr_is_opmask().
 - Added reg_set_value_ex() to set XMM, YMM and ZMM values.
 - Added the functions instr_set_encoding_hint(), instr_has_encoding_hint().
 - Added the type #dr_encoding_hint_type_t.
 - Added #INSTR_ENCODING_HINT macro.
 - Added dr_standalone_exit() with support for re-attaching afterward.
 - Added dr_register_low_on_memory_event() for tracking low on memory events.
 - Added dr_mcontext_zmm_fields_valid() to query the state of lazy AVX-512 context
   switching.
 - Added the function proc_avx512_enabled().
 - Added support for applications using the Linux kernel's restartable sequence
   ("rseq") feature, subject to the limitations listed in \ref sec_rseq.
 - Added coherence support in drcachesim.
 - Added the function proc_num_opmask_registers();
 - reg_get_value_ex() now supports reading AVX-512 mask registers.
 - Added the function reg_is_bnd().
 - Added the functions instr_is_gather() and instr_is_scatter().
 - Added the function drx_expand_scatter_gather().
 - Added the function dr_atomic_add64_return_sum().
 - Added the function instr_reads_from_exact_reg() to test whether instructions
   read from exact registers.
 - Added the function reg_is_vector_simd() to test whether registers are
   either XMM, YMM or ZMM, excluding any MMX register checks.
 - Added DR_NUM_SIMD_VECTOR_REGS as an alias to MCXT_NUM_SIMD_SLOTS in order
   to get the static number of supported SIMD vectors.
 - Added drmgr_register_low_on_memory_event(), drmgr_unregister_low_on_memory_event()
   and their variants so that drmgr can support low-on-memory events.
 - Added drmgr_is_first_nonlabel_instr() and instrlist_first_nonlabel().
 - Added a new standalone tool "drdisas" which disassembles raw bytes using
   DR's decoder.
 - Added decode_sizeof_ex() and instr_get_rel_data_or_instr_target() handling
   relative instruction references.
 - Added drx_instrlist_size() and drx_instrlist_app_size() to obtain the size
   of a basic block.
 - Added drreg_restore_all() to restore all unreserved registers currently
   maintained by drreg.
 - Added a func_view tool to drcachesim for analyzing function traces.
 - Added a non-heap-using instruction structure #instr_noalloc_t for use when
   decoding in a signal handler, along with instr_noalloc_init() and
   instr_from_noalloc().
 - Added drwrap_get_stats().
 - Added #DRWRAP_NO_DYNAMIC_RETADDRS for reducing drwrap overhead at the cost
   of missing some post-call callbacks.
 - Added #DRWRAP_REPLACE_RETADDR for an alternative method of setting up post-call
   control points by replacing return addresses.  This does not work for every
   application, but reduces overhead.
 - Added -record_dynsym_only to drcachesim for faster function tracing symbol
   lookups when internal symbols are not needed.
 - Added -record_replace_retaddr_only to drcachesim for faster function tracing
   wrapping for well-behaved applications.
 - Added dr_merge_arith_flags() as a convenience routine to merge arithmetic flags
   for restoration done by outlined code.
 - Added dr_annotation_pass_pc() to obtain the interrupted PC in an annotation
   handler.
 - Added atomics for safe and visible aligned loads and stores on all platforms:
   dr_atomic_load32(), dr_atomic_store32(), dr_atomic_load64() dr_atomic_store64().
 - The state restore event (dr_register_restore_state_event()) is now called for
   all translation attempts, even when the register state already contains
   application values, to allow clients to restore memory.
 - Added the function dr_get_process_id_from_drcontext() for obtaining a process ID
   associated with the given drcontext, which may be different from the current
   dr_get_process_id() in some contexts.
 - The private loader's malloc redirection now guarantees double-pointer-sized
   alignment, to match what system-provided allocators use.
 - Added a new DR extension, namely "drbbdup", which enables different case
   instrumentation of the same basic block by duplicating code.

**************************************************
<hr>

Version 7.1.0 includes Dr. Memory and the Dr. Memory Framework (DRMF) in
the same package as DynamoRIO.  DRMF provides the umbra, drsyscall, and
drsymcache Extensions for use by clients.

The changes between version 7.1.0 and 7.0.0 include the following minor
compatibility changes:

 - The drltrace tool has been moved to the Dr.Memory Framework.
 - Removed DRMGR_PRIORITY_INSERT_CLS_ENTRY, DRMGR_PRIORITY_INSERT_CLS_EXIT,
   DRMGR_PRIORITY_NAME_CLS_ENTRY, and DRMGR_PRIORITY_NAME_CLS_EXIT, as
   the new kernel xfer event (drmgr_register_kernel_xfer_event()) removes the
   need for them.
 - Renamed the LOG_ macros (#LOG_NONE, #LOG_ALL, etc.) to have a DR_ prefix
   to avoid name conflicts.  Clients should set(DynamoRIO_LOG_COMPATIBILITY ON)
   prior to configure_DynamoRIO_client() to use the old constants and avoid
   any source changes; this will happen automatically if the client
   targets version 7.0.0 or earlier.  Binary compatibility is unaffected.
 - Added a parameter to cmake functions DynamoRIO_get_target_path_for_execution and
   DynamoRIO_copy_target_to_device. External projects outside of DynamoRIO need
   to pass _DR_location_suffix.
 - The drcachesim tool's offline traces are now stored in separate files per traced
   application thread, rather than a single interleaved file.  Reading and analyzing
   a legacy interleaved file is still supported, but all new generated traces are
   split.  Splitting enables parallelized post-processing and trace analysis.
 - In standalone mode, there are no 32-bit-displacement reachability guarantees
   regarding DynamoRIO's heap.

Further non-compatibility-affecting changes include:

 - Added drx_buf_insert_buf_memcpy().
 - Added XINST_CREATE_add_sll(), XINST_CREATE_jump_cond(), and XINST_CREATE_slr_s().
 - Added thread synchronization events via dr_event_create(), dr_event_destroy(),
   dr_event_wait(), dr_event_signal(), and dr_event_reset().
 - Added drmodtrack customization via drmodtrack_add_custom_data() and
   post-processing support via drmodtrack_offline_write().
 - Added drcachesim customization via drmemtrace_replace_file_ops(),
   drmemtrace_custom_module_data(), drmemtrace_get_output_path(),
   drmemtrace_get_modlist_path(), and a separate rawtrace library for
   post-processing customization with raw2trace_t::handle_custom_data(),
   raw2trace_t::do_module_parsing(), raw2trace_t::do_conversion(), and
   raw2trace_directory_t.  The raw2trace library also includes an interface
   for obtaining further instruction information than is stored in the
   trace via raw2trace_t::do_module_parsing_and_mapping() and
   raw2trace_t::find_mapped_trace_address().
   A corresponding CMake function for finding the
   tracer customization header is use_DynamoRIO_drmemtrace_tracer().
 - Added drreg_restore_app_aflags().
 - Added a set_value() function to the \ref page_droption.
 - Added instrlist_get_auto_predicate() and instrlist_set_auto_predicate().
 - Globally enabled auto predication in the drmgr instrumentation insertion event by
   default.
 - Added drmgr_disable_auto_predication().
 - Added a new option -signal_stack_size with a smaller default value than
   before, to save space on applications with many threads.
 - Added instr_predicate_is_cond().
 - Added a hardware data next-line prefetcher to drcachesim.  It is on by
   default, so simulation results may not match those in prior releases.
   It can be disabled by running with "-data_prefetcher none" (see \ref
   sec_drcachesim_ops).
 - Added a last-level cache miss recording feature to drcachesim.
 - Added a delayed tracing feature to drcachesim.
 - Added an option to drcachesim to specify cache warmup by loaded fraction of the
   last level cache.
 - On Linux, the VDSO module is now included in the module list at program
   startup.
 - Added support for Windows 10 1703.  We provide an artificial version
   identifier #DR_WINDOWS_VERSION_10_1703 to distinguish this major update.
 - Added support for Windows 10 1709.  We provide an artificial version
   identifier #DR_WINDOWS_VERSION_10_1709 to distinguish this major update.
 - Added an event for kernel-mediated control flow via
   dr_register_kernel_xfer_event() with corresponding routines
   drmgr_register_kernel_xfer_event() and drmgr_register_kernel_xfer_event_ex().
 - Added a new option -ignore_all_libs to drcpusim.
 - Added several new trace analysis tools to drcachesim: reuse distance,
   reuse time, histogram, and trace basic counts.
 - Added a trace analysis tool framework to facilitate creating custom
   trace tools using the CMake function use_DynamoRIO_drmemtrace() and
   exported drmemtrace_analyzer and analysis tool libraries.
 - Added the CMake function configure_DynamoRIO_main_headers() to
   facilitate using drfrontendlib by itself.
 - Added instr_is_string_op() and instr_is_rep_string_op().
 - Added dr_app_recurlock_lock().
 - Added hashtable_apply_to_all_payloads() to iterate over all payloads in a
   hashtable.
 - Added drutil_insert_get_mem_addr_ex().
 - Added dr_vfprintf().
 - Added drmgr_register_thread_init_event_user_data() and
   drmgr_unregister_thread_init_event_user_data() to enable passing of user data.
 - Added drmgr_register_thread_exit_event_user_data() and
   drmgr_unregister_thread_exit_event_usr_data() to enable passing of user data.
 - Added drmgr_register_module_load_event_user_data() and
   drmgr_unregister_module_load_event_user_data() to enable passing of user data.
 - Added drmgr_register_module_unload_event_user_data() and
   drmgr_unregister_module_unload_event() to enable passing of user data.
 - Added a new drcachesim feature that records which cpu each thread
   executed on along with an optional simulator scheduling feature to
   schedule threads on simulated cores to match the recorded execution on
   physical cpus.
 - Added #DR_DISALLOW_UNSAFE_STATIC and dr_allow_unsafe_static_behavior()
   for sanity checks to help support statically-linked clients.
 - Added drmgr_register_pre_syscall_event_user_data() and
   drmgr_unregister_pre_syscall_event_user_data() to enable passing of user data.
 - Added drmgr_register_post_syscall_event_user_data() and
   drmgr_unregister_post_syscall_event_user_data() to enable passing of user data.
 - Added dr_where_am_i(), dr_track_where_am_i(), and dr_is_tracking_where_am_i()
   better support client self-profiling via sampling.
 - Added dr_get_stats() to retrieve runtime stats. Currently limited to number
   of built basic blocks.
 - Added drreg_reservation_info_ex(), drreg_statelessly_restore_app_value(),
   and drreg_is_instr_spill_or_restore().
 - Added dr_app_stop_and_cleanup_with_stats() to obtain stats values right before
   cleanup.
 - drmodtrack now allocates an entry per segment for each loaded module.
   Added a file offset field to module_segment_data_t for UNIX platforms.
   drcachesim saves file offset information in modules.log on UNIX platforms.
 - Added dr_prepopulate_cache() and dr_prepopulate_indirect_targets() for
   setting up the code cache prior to execution.
 - Added support for Windows 10 1803. We provide an artificial version
   identifier #DR_WINDOWS_VERSION_10_1803 to distinguish this major update.
 - Generalization of the drcachesim #dynamorio::drmemtrace::raw2trace_t API (Issue #3129):
   - Added #dynamorio::drmemtrace::module_mapper_t, which factors out the module mapping functionality
     out of #dynamorio::drmemtrace::raw2trace_t, replacing the following #dynamorio::drmemtrace::raw2trace_t APIs:
     #dynamorio::drmemtrace::raw2trace_t::handle_custom_data(), #dynamorio::drmemtrace::raw2trace_t::do_module_parsing(),
     #dynamorio::drmemtrace::raw2trace_t::do_module_parsing_and_mapping(), and
     #dynamorio::drmemtrace::raw2trace_t::find_mapped_trace_address().
   - Added #dynamorio::drmemtrace::trace_metadata_writer_t, a set of utility functions used by drcachesim's
     #dynamorio::drmemtrace::raw2trace_t for writing trace metadata: process/thread ids, timestamps, etc.
   - Added #dynamorio::drmemtrace::trace_metadata_reader_t, a set of utilities for checking and validating
     thread start successions of offline entries in a raw data file.
   - Added trace_converter_t, an extensibility mechanism for raw trace conversion.
 - Added drmemtrace_get_timestamp_from_offline_trace(), an API for fetching the timestamp
   from the beginning of a raw trace bundle (regardless of whether it is a thread start
   or just a subsequent bundle).
 - Added dr_abort_with_code().
 - Added support for interoperability between emulation clients and observational
   clients: #emulated_instr_t, drmgr_insert_emulation_start(),
   drmgr_insert_emulation_end(), drmgr_is_emulation_start(), drmgr_is_emulation_end()
   and drmgr_get_emulated_instr_data().
 - Added drmgr_register_signal_event_user_data() and
   drmgr_unregister_signal_event_user_data() to enable passing of user data.
 - Added hashtable_apply_to_all_payloads_user_data() to iterate over all payloads
   in a hashtable with user data also available.
 - Added cmake function DynamoRIO_get_full_path that shall be used instead of reading
   the LOCATION target property.
 - Added a drcachesim/drmemtrace analysis tool routine initialize() to help separate
   initialization that could fail from tool construction.
 - Split raw2trace_directory_t initialization from its constructors
   into new initialize() and initialize_module_file() methods.
 - Added drcachesim/drmemtrace support for analyzing offline traces in parallel,
   concurrently operating on each traced thread (or other sharding division).  This
   is made possible by the new storage of traces in separate files.  Adds a new
   analysis_tool_t interface where if the tool's parallel_shard_supported() returns
   true, analyzer_t switches to a parallel operation mode.  Today, a simple static
   scheduling among worker threads is used.  Each worker completely owns one or more
   shards, eliminating the need for synchronization when processing a thread's trace
   entries.  The tools' parallel_shard_init() function is invoked to create
   traced-thread-local data, which is passed to parallel_shard_memref().  A
   parallel_shard_exit() is provided for cleanup, though most tools will sort,
   aggregate, and clean up in print_results().
 - Added module_mapper_t::find_mapped_trace_bounds() to allow callers to cache
   results and avoid global locks during parallel operation.

**************************************************
<hr>

Version 7.0.0 includes Dr. Memory and the Dr. Memory Framework (DRMF) in
the same package as DynamoRIO.  DRMF provides the umbra, drsyscall, and
drsymcache Extensions for use by clients.

The changes between version 7.0.0 and 6.2.0 include the following minor
compatibility changes:

 - Changed dr_app_stop() to send all threads native instead of only the
   calling thread.
 - Replaced PAGE_SIZE with dr_page_size() and removed PAGE_START from the API.
   However, clients may set(DynamoRIO_PAGE_SIZE_COMPATIBILITY ON), in which
   case definitions of PAGE_SIZE and PAGE_START using dr_page_size() are
   provided, though code that uses these macros in a constant expression,
   such as a static initialiser, will still need to be rewritten.
   DynamoRIO_PAGE_SIZE_COMPATIBILITY will be set automatically if the
   client targets version 6.2 or earlier.

Further non-compatibility-affecting changes include:

 - Added preliminary AArch64 ARMv8 support: see \ref sec_limits for a
   description of what is not yet expected to work.
 - Added a static library form of DynamoRIO for use either with
   auto-takeover or the start/stop API.  The configure_DynamoRIO_static()
   and use_DynamoRIO_static_client() CMake utilities facilitate this.
 - Enabled \ref page_drcachesim for Windows for single-process applications.
 - Added a module tracking feature \p drmodtrack for quick identification of which
   library a program counter belongs to and for persistent labeling of
   modules for post-processing and across library reloads.  This is part of
   the \p drcovlib Extension.  See #drmodtrack_init() and related functions.
 - Added drx_open_unique_appid_dir().
 - Added #DRX_FILE_SKIP_OPEN.
 - Added %[] support to dr_sscanf.
 - Added dr_map_executable_file() and dr_unmap_executable_file().
 - Added dr_get_microseconds().
 - Added #DR_CLEANCALL_ALWAYS_OUT_OF_LINE.
 - Added instr_create_4dst_2src().
 - Added drreg_restore_app_values() and drreg_restore_app_aflags().
 - Added drx_tail_pad_block().
 - Added XINST_CREATE_load_1byte_zext4().

**************************************************
<hr>

Version 6.2.0 includes Dr. Memory and the Dr. Memory Framework (DRMF) in
the same package as DynamoRIO.  DRMF provides the umbra, drsyscall, and
drsymcache Extensions for use by clients.

The changes between version 6.2.0 and 6.1.0 include:

 - Added support for Windows 10 1607.  We provide an artificial version
   identifier #DR_WINDOWS_VERSION_10_1607 to distinguish this major update.
 - Split the memory trace sample memtrace_x86 into memtrace_x86_text and
   memtrace_x86_binary to highlight the huge performance difference.
 - Added instruction trace samples instrace_simple, instrace_x86_text, and
   instrace_x86_binary.
 - Added better drreg support for intra-bb control flow by adding
   drreg_set_bb_properties().
 - Added priority-controlled drmgr_register_thread_init_event_ex() and
   drmgr_register_thread_exit_event_ex().
 - Added \ref sec_drx_buf to drx: drx_buf_create_circular_buffer(),
   drx_buf_create_trace_buffer(), and more.
 - Documented that drx_insert_counter_update() does rely on drx_init().
 - Better international string support for usernames and application
   paths.

**************************************************
<hr>

Version 6.1.0 includes Dr. Memory and the Dr. Memory Framework (DRMF) in
the same package as DynamoRIO.  DRMF provides the umbra, drsyscall, and
drsymcache Extensions for use by clients.

The changes between version 6.1.0 and 6.0.0 include the
following minor compatibility changes:

 - Fixed problems with configuration directories on Android.  This involved
   changing drfront_access() to attempt to create a file by calling a new
   routine that is also exported, drfront_dir_try_writable().
 - Fixed several bugs.

**************************************************
<hr>

Version 6.1.0 includes Dr. Memory and the Dr. Memory Framework (DRMF) in
the same package as DynamoRIO.  DRMF provides the umbra, drsyscall, and
drsymcache Extensions for use by clients.

The changes between version 6.1.0 and 6.0.0 include the
following minor compatibility changes:

 - Changed drreg_aflags_liveness() to take in the target instruction.

Further non-compatibility-affecting changes include:

 - Added support for C++ clients on Android via private loader support for
   Bionic.
 - opnd_size_in_bytes() and opnd_size_in_bits() no longer accept DR_REG_
   constants as input (the caller must first call reg_get_size()).
   This was true in the 6.0.0 release but the documentation and the
   routines themselves did not reflect this.
 - Added drreg_init_and_fill_vector() and drreg_set_vector_entry().
 - Augmented drx_insert_counter_update() to work with drreg.
 - Added dr_raw_tls_opnd().
 - Added drreg_reservation_info().
 - Added opnd_create_rel_addr() and opnd_is_rel_addr() support for ARM.
 - Added drreg_is_register_dead() and drreg_reserve_dead_register().
 - Split out the core functionality of the \ref page_drcov tool into
   a new Extension \p drcovlib for easier inclusion of coverage output in
   other tools.
 - Added support for the Windows 10 TH2 1511 update.  We provide an
   artificial version identifier #DR_WINDOWS_VERSION_10_1511 to distinguish
   this major update.

**************************************************
<hr>

Version 6.0.0 includes Dr. Memory and the Dr. Memory Framework (DRMF)
in the same package as DynamoRIO.  DRMF provides the umbra, drsyscall, and
drsymcache Extensions for use by clients.

The changes between version 6.0.0 and 5.0.0 include the
following minor compatibility changes:

 - Deprecated dr_init() as a client's entry point, replacing it with
   dr_client_main() which is passed an argv-style array of client options
   just like a regular application's main() routine.
 - Changed the default injection method on Linux to use "early injection"
   which begins executing the target application from its very first
   instruction.  Clients on Linux will now see more application code than
   they did previously.  The old behavior can be requested by passing
   "-late" to drrun or drinject, or including "-no_early_inject" in the
   options to drinjectlib.
 - Moved the module load event to a later point where the application first
   executes code from the library.  This enables clients to access properly
   relocated values inside the library, which was not possible with the
   prior event point at the first memory mapping of the library.
   Applications that still wish to see the first mapping will need to
   monitor system calls to replicate the old control point.
 - To support conditionally executed instructions, added a new parameter of
   type #dr_opnd_query_flags_t to routines that explicitly query what was
   read or written by an instruction: instr_get_eflags(),
   instr_get_arith_flags(), decode_eflags_usage(), instr_writes_to_reg(),
   instr_reads_from_reg(), and instr_writes_to_exact_reg().  This new
   parameter determines how to treat conditionally accessed operands.  We
   decided that breaking compatibility directly was the best solution to
   ensure that clients performing liveness analysis versus other types of
   usage analysis are properly updated to handle conditionally executed
   instructions.  All other API routines include all operands whether
   conditionally accessed or not.
 - Removed the artificial additional source operand that was added to each
   OP_cmovcc and OP_fcmovcc instruction in the past.  We have replaced this
   with the new predication API (instr_is_predicated(), etc.) and new
   parameters to read/write query routines (#dr_opnd_query_flags_t).
 - Widened the #reg_id_t type from a byte to a ushort.
 - Changed both drconfiglib and drinjectlib to be static libraries rather
   than shared libraries on UNIX platforms, for simpler usage without
   worrying about locating them at runtime, as well as making it easier to
   use on Android.  They remain shared libraries on Windows.
 - Deprecated dr_get_options(), replacing it with direct arguments to
   dr_client_main() or alternatively with dr_get_option_array().
 - Deprecated set_x86_mode(), replacing it with dr_set_isa_mode().
 - Deprecated get_x86_mode(), replacing it with dr_get_isa_mode().
 - Deprecated instr_set_x86_mode(), replacing it with instr_set_isa_mode().
 - Deprecated instr_get_x86_mode(), replacing it with instr_get_isa_mode().
 - Added a third parameter to drfront_is_64bit_app().
 - Deprecated instr_is_sse_or_sse2().
 - Removed legacy executable bbcov2lcov.
 - Removed legacy "-t bbcov" support.

Further non-compatibility-affecting changes include:

 - Added AArch32 ARMv7 and ARMv8 support.
 - Added experimental Android support.  C clients are supported, but C++
   clients are not yet supported.
 - Added Windows 10 support.
 - Added a new scratch register coordination Extension, \p drreg.
   The \p drreg Extension is still considered experimental and its
   interface is subject to change in the next release.
 - Added easy-to-use option declaration and parsing for C++ clients
   and standalone applications via a new Extension, the \ref page_droption
   and the #dynamorio::droption::droption_t class.
 - Added a new tool: \ref page_drcachesim, a multi-process cache simulator.
 - Added a new tool: \ref page_drcpusim, a CPU simulator for illegal
   instructions on legacy processors.
 - Added distinctions between reasons for dr_query_memory_ex() to fail
 - Added opnd_size_in_bits().
 - Added cross-platform instruction creation macros
   XINST_CREATE_debug_instr(), XINST_CREATE_load(), XINST_CREATE_store(),
   XINST_CREATE_move(), XINST_CREATE_load_simd(), XINST_CREATE_store_simd(),
   XINST_CREATE_jump_mem(), XINST_CREATE_jump_reg(), XINST_CREATE_load_int(),
   XINST_CREATE_jump(), XINST_CREATE_jump_short(),
   XINST_CREATE_call(), XINST_CREATE_return(),
   XINST_CREATE_add(), XINST_CREATE_add_2src(), XINST_CREATE_add_s(),
   XINST_CREATE_sub(), XINST_CREATE_sub_s(),
   XINST_CREATE_and_s(), XINST_CREATE_cmp(),
   XINST_CREATE_interrupt(), XINST_CREATE_nop(),
   XINST_CREATE_load_1byte(), XINST_CREATE_load_2bytes(),
   XINST_CREATE_store_1byte(), and XINST_CREATE_store_2bytes().
 - Added a new feature: a binary annotation framework that facilitates communication
   between the target app and the DynamoRIO client and core. See \ref sec_annotations
   and dr_annotation.h.
 - Added instr_is_predicated(), instr_get_predicate(), and
   instr_set_predicate().
 - Added instr_predicate_triggered().
 - Added dr_save_arith_flags_to_reg() and dr_restore_arith_flags_from_reg().
 - Added opnd_get_index_shift() and opnd_set_index_shift().
 - Added opnd_create_reg_ex() and opnd_get_flags().
 - Added opnd_create_base_disp_arm().
 - Added reg_is_simd().
 - Added instr_create_0dst_4src(), instr_create_1dst_4src(),
   instr_create_2dst_5src(), instr_create_Ndst_Msrc_vardst(),
   and instr_create_Ndst_Msrc_varsrc().
 - Added OPND_CREATE_MEMLIST().
 - Added dr_get_stolen_reg(), dr_insert_get_stolen_reg_value(),
   dr_insert_set_stolen_reg_value(), and reg_is_stolen().
 - Added opnd_create_immed_uint().
 - Added instr_remove_srcs() and instr_remove_dsts().
 - Added cross-platform #EFLAGS_READ_ARITH and #EFLAGS_WRITE_ARITH.
 - Added instr_invert_predicate() and instr_predicate_name().
 - Added instr_it_block_get_count(), instr_it_block_get_pred(),
   instr_it_block_compute_immediates(), and instr_it_block_create()
   for manipulating IT block instructions on ARM.
 - Added opnd_set_flags().
 - Added opnd_create_immed_int64(), opnd_is_immed_int64(), and
   opnd_get_immed_int64() for 64-bit immediate SIMD constants on 32-bit ARM.
 - Added dr_set_client_version_string().
 - Added instr_get_prev_app() and instrlist_last_app().
 - Added the \ref op_syntax_arm "-syntax_arm" runtime option.
 - Added opnd_add_flags().
 - Added drmgr_unregister_bb_insertion_event().
 - Added drmgr_is_first_instr() and drmgr_is_last_instr().
 - Added dr_app_pc_as_jump_target() and dr_app_pc_as_load_target().
 - Added dr_remove_it_instrs() and dr_insert_it_instrs().
 - Added automated conditional instrumentation to drmgr.
 - Added dr_insert_read_raw_tls() and dr_insert_write_raw_tls().
 - Added instr_is_exclusive_store().
 - Added #DR_FILE_WRITE_ONLY.
 - Added dr_get_option_array().
 - Added drwrap_redirect_execution().
 - Added support for common calling conventions in drwrap.
 - Added a new sample client, named ssljack.
 - Added the -pathmap option to the post-processor for \ref page_drcov.
 - Added instr_is_sse() and instr_is_sse2().
 - Added instr_is_3DNow(), instr_is_sse3(), and instr_is_ssse3().
 - Added instr_is_sse41(), instr_is_sse42(), and instr_is_sse4A().
 - Added instr_is_reg_spill_or_restore().
 - Added #DR_MEMPROT_VDSO.

**************************************************
<hr>

Version 5.0.0 includes Dr. Memory and the Dr. Memory Framework (DRMF)
in the same package as DynamoRIO.  DRMF provides the umbra, drsyscall, and
drsymcache Extensions for use by clients.

The changes between version 5.0.0 and 4.2.0 also include the
following minor compatibility changes:

 - Dropped official support for Windows 2000.  The core DynamoRIO engine
   should continue to work there, but the official release package
   will not run on Windows 2000.
 - Changed the third parameter to drsym_search_symbols_ex() from a bool to
   a uint flags in order to take in demangling flags.  Binary compatibility
   is maintained as drsym_info_t's size was changed, but source
   compatibility is affected by this change.
 - Added collapsing of template parameters to "<>" for drsyms operations on
   Windows PDB symbols when #DRSYM_DEMANGLE is specified.  This can be
   undone by specifying #DRSYM_DEMANGLE_PDB_TEMPLATES.
 - Removed empty parentheses "()" from partially-demangled symbols (when
   #DRSYM_DEMANGLE is specified) for #DRSYM_ELF_SYMTAB and #DRSYM_PECOFF_SYMTAB.
   Windows and Linux symbols are now consistent for #DRSYM_DEMANGLE.
 - Changed the operand sizes of instructions that read or write only part
   of a multimedia register (mmx, xmm, or ymm) to reflect the partial size.
 - Added return value for dr_fprintf to indicate how many bytes are written.
 - Renamed the function add_rel_rpaths() in DynamoRIOConfig.cmake to
   DynamoRIO_add_rel_rpaths().
 - Deprecated instr_ok_to_mangle() and instr_set_ok_to_mangle()
   (replaced with instr_is_app(), instr_is_meta(), instr_set_app(), and
   instr_set_meta()).

Further non-compatibility-affecting changes include:

 - Added dr_syscall_get_result_ex() and dr_syscall_set_result_ex() for
   future MacOS support.
 - Added Mach-O support to drsyms.
 - Added INSTR_CREATE_cmpxchg_8() for 64-bit cmpxchg
 - Changed the default -stderr_mask on Windows to 0xC (for both release
   and debug), and the default -msgbox_mask on Windows release builds
   to 0xC, for better error reporting.  For interactive runs, then,
   the user should explicitly pass -msgbox_mask 0.
 - Added a flags output parameter to #drsym_info_t.
 - Added dr_module_contains_addr() to make handling non-contiguous
   libraries easier.
 - Added hashtable_lock_self_owns() to the drcontainers Extension.
 - Added opnd_create_reg_partial() and opnd_is_reg_partial() for
   representing a partial multimedia register
 - Added operand size suffixes on disassembly in the default mode.
   This can be disabled via -disasm_mask 0x8 or by calling
   disassemble_set_syntax(DR_DISASM_NO_OPND_SIZE).
 - Added instr_zeroes_ymmh().
 - Added new fields to module_data_t: timestamp for Linux and MacOS, and
   version and uuid fields for MacOS.
 - Added a new library drfrontendlib to be used for building tool
   front-ends.  For more information see dr_frontend.h.
 - Added dr_create_memory_dump().
 - Added dr_mcontext_to_context().
 - Added dr_call_on_clean_stack().
 - Added dr_set_client_name() for customizing the diagnostic message
   presented to users when an error occurs or when dr_messagebox() is called.
 - Added instr_get_next_app() and instrlist_first_app() to allow clients to
   traverse only application (non-meta) instructions.
 - Added dr_config_status_code_to_string().
 - Added custom tool front-end launching support to drrrun tool config files.
 - Added a tool notification feature to drrun tool config files.
 - Added get_visualstudio_info() for looking up visual studio
   installation information.
 - Renamed the strace sample to "syscall" and removed its tracing feature,
   in favor of a superior strace sample inside DRMF.
 - Included a copy of dbghelp.dll for drsyms
 - Added dr_insert_cbr_instrumentation_ex(),
   which provides the fall-through address.
 - Added instr_is_app(), instr_is_meta(), instr_set_app(), and instr_set_meta().
 - Added reg_get_value_ex().

**************************************************
<hr>
The changes between version 4.2.0 and 4.1.0 include:

 - Added preliminary Windows 8.1 support
 - Added a new Library Tracing Tool, drltrace.
 - Re-branded our \ref page_drcov
 - Added an export iterator: dr_symbol_export_iterator_start(),
   dr_symbol_export_iterator_hasnext(), dr_symbol_export_iterator_next(),
   dr_symbol_export_iterator_stop()
 - Added relative directory support to file routines on Windows
 - Added dr_get_current_directory()
 - Added dr_delete_dir()
 - Added drx_open_unique_file() and drx_open_unique_appid_file()
 - Added proc_avx_enabled()
 - Added support for recent IA-32/AMD64 instructions: the rdrand,
   fsgsbase, FMA4, XOP, TBM, LWP, BMI1, BMI2, SMX, INVPCID,
   TSX, and AVX2 instruction groups
 - Added vector addressing (VSIB) support to instr_compute_address(),
   instr_compute_address_ex() and
   instr_compute_address_ex_pos()
 - Added opnd_is_vsib()
 - Fixed misnamed opcodes: OP_pmovsxdw is now OP_pmovsxwd,
   OP_pmovzxdw is now OP_pmovzxwd, OP_vpmovsxdw is now OP_vpmovsxwd,
   and OP_vpmovzxdw is now OP_vpmovzxwd.
 - Renamed DRgui to DRstats in anticipation of a new DRgui graphical tool framework
 - dr_exit_process() now supports sending a fatal signal via the 2nd byte of
   the exit code being set to the signal number
 - Added a return value of NULL to dr_standalone_init() to indicate
   failure, such as running on an unsupported OS
 - Added a "soft kills" feature to the \p drx Extension via
   drx_register_soft_kills() to avoid child process termination preventing
   output of instrumentation results
 - Added dr_convert_pid_to_handle()
 - Added dr_syscall_intercept_natively()
 - Added dr_app_handle_mbr_target()
 - Added dr_app_running_under_dynamorio()
 - Added drvector_set_entry()
 - Re-ordered the initial thread init event to be prior to the initial
   module load events
 - Changed DynamoRIO_USE_LIBC to be on by default for all clients,
   including clients written in C
 - Added static library versions of most Extension libraries: drmgr_static,
   drutil_static, drwrap_static, drsyms_static, and drx_static.
   Be sure to check the licenses and other restrictions (in particular,
   most of these Extensions will not work properly if duplicated)
   before using these static versions.
 - Various bug fixes

**************************************************
<hr>
The changes between version 4.1.0 and 4.0.1 include the
following compatibility changes:

 - The #drsym_info_t data structure has changed.  The file name is now
   a caller-allocated buffer, and it and the symbol name are separated out.
   This affects code that calls drsym_lookup_address().
 - Memory allocated through system libraries (including malloc, operator
   new, and HeapAlloc) is not guaranteed to be reachable by a 32-bit
   displacement from the code cache: only memory directly allocated via
   DR's API.  The \ref op_reachable_heap "-reachable_heap runtime option"
   can be used to guarantee that all memory is reachable.
 - For 64-bit, the opcode constants OP_fxsave, OP_fxrstor, OP_xsave,
   OP_xrstor, and OP_xsaveopt have all been replaced with two versions: one
   with a "32" suffix and one with a "64" suffix.  E.g., OP_fxsave is split
   into #OP_fxsave32 and #OP_fxsave64.  The 32 version corresponds to the
   no-suffix assembler mnemonic while the 64 version coresponds to the
   assembler mnemonic of the same name.  Previously, the 64-bit versions of
   these instrutions could not be distinguished nor encoded from scratch.

Further non-compatibility-affecting changes include:

 - Added instr_is_floating_ex()
 - Ported the stats.c sample and DRgui to 64-bit.  As part of this, the
   shared memory structure changed shape on Windows: pid is now of type
   process_id_t.
 - Added the \p drtable Extension which provides simple table management
 - Added opnd_size_from_bytes()
 - Added path searching support to dr_load_aux_library()
 - Added limited, experimental support for 32-bit WOW64 clients to use
   64-bit libraries and code via dr_load_aux_x64_library(),
   dr_lookup_aux_x64_library_routine(), dr_unload_aux_x64_library(), and
   dr_invoke_x64_routine().
 - Added drmgr_current_bb_phase()
 - The deployment tools (drrun, drconfig, and drinject) are now helper
   binaries instead of shell scripts.
 - The deployment tools (drrun etc.) now interpret -v as an alias for
   -verbose and use -version to print version info.
 - Added instrlist_insert_mov_immed_ptrsz() and instrlist_insert_push_immed_ptrsz()
 - Added instrlist_insert_mov_instr_addr() and instrlist_insert_push_instr_addr()
 - Added drsym_enumerate_lines()
 - Added #DR_DISASM_STRICT_INVALID
 - Added a new runtime option \ref op_syntax_att "-syntax_att" for
   AT&T-style disassembly that hides the implicit operands.
   Also added #DR_DISASM_DR to name DR's default disassembly style, with
   #DR_DISASM_ATT selecting a true AT&T disassembly style that hides
   implicit operands.  The only compatibility change here is if a client
   selected DR_DISASM_ATT and expected DR-style disassembly.
 - Added #DR_MAP_IMAGE
 - Added -t option to drrun for end-user tools
 - Added 64-bit reachability support to dr_insert_call() and
   dr_insert_clean_call().  Added explicit control over reachability
   in a new routine dr_insert_call_ex() and in #DR_CLEANCALL_INDIRECT
   for dr_insert_clean_call_ex().
 - Added auto-magic conversion of absolute and pc-relative memory
   operands to each other for more flexible 64-bit encoding.
 - Added opnd_create_instr_ex() and opnd_get_shift()
 - Added dr_custom_alloc()
 - Added dr_raw_mremap() and dr_raw_brk()
 - Added #DR_EMIT_GO_NATIVE, dr_suspend_all_other_threads_ex(),
   dr_retakeover_suspended_native_thread(), and dr_is_thread_native() for
   temporarily-native support.
 - Added dr_get_token()
 - Added dr_switch_to_app_state_ex() and dr_switch_to_dr_state_ex()
 - Added dr_is_nudge_thread()
 - Added support for nudging 64-bit Windows applications
 - Added dr_get_dr_thread_handle()
 - Added #DR_MEMTYPE_RESERVED to #dr_mem_info_t
 - proc_save_fpstate(), proc_restore_fpstate(), dr_insert_save_fpstate(),
   and dr_insert_restore_fpstate() now use the current thread's x86 mode
   to determine which fxsave state format to use.
 - Added partial support for presenting the proper floating point program
   counter when floating point state is saved.
   Xref the \ref op_translate_fpu_pc "-translate_fpu_pc runtime option".
 - Added \p drx Extension: the DynamoRIO Instrumentation Utility
   Extension with BSD license
 - Added automatic restarting of appropriate system calls interrupted by signals.
 - Various bug fixes

**************************************************
<hr>
The changes between version 4.0.1 and 4.0.0 include:

 - Fixed a bug resulting in large 64-bit applications failing to allocate
   heap (Issue 1041)

**************************************************
<hr>
The changes between version 4.0.0 and 3.2.0 include a
compatibility change in the drsyms Extension:

 - Changed the drsyms type query data structures (#drsym_type_t,
   #drsym_func_type_t, #drsym_int_type_t, #drsym_ptr_type_t).
   This is a binary compatibility change for drsym_get_func_type().

And in the drmgr Extension:

 - The post-syscall, module load, module unload, signal, exception,
   and restore state events are now mediated and ordered by drmgr.
   Thus, clients should call drmgr_register_post_syscall_event()
   (for a default priority) or drmgr_register_post_syscall_event_ex() (to
   specify a priority) rather than
   dr_register_post_syscall_event().  The same applies to
   drmgr_register_module_load_event() +
   drmgr_register_module_load_event_ex(),
   drmgr_register_module_unload_event() +
   drmgr_register_module_unload_event_ex(),
   drmgr_register_signal_event() +
   drmgr_register_signal_event_ex(),
   drmgr_register_exception_event() +
   drmgr_register_exception_event_ex(), and
   drmgr_register_restore_state_event() +
   drmgr_register_restore_state_ex_event() +
   drmgr_register_restore_state_ex_event_ex().

And in the core API:

 - dr_get_milliseconds() now returns the number of milliseconds since Jan
   1, 1601 on all platforms.

And in the non-core APIs:

 - dr_inject_process_create() now takes a NULL-terminated array of strings for
   the app command line to better support porting to Linux.

Further non-compatibility-affecting changes include:

 - Added preliminary Windows 8 support, though private kernelbase.dll is
   not yet supported
 - Added persistent cache support for clients via
   dr_register_persist_ro(), dr_register_persist_rx(),
   dr_register_persist_rw(), dr_register_persist_patch(), and
   #DR_EMIT_PERSISTABLE.  However, dr_register_persist_patch() is
   still experimental, is in flux, and is subject to change in
   the next release.
 - Added hashtable persistence support via hashtable_persist_size(),
   hashtable_persist(), and hashtable_resurrect()
 - Added drsym_get_type(), drsym_expand_type(), and support for additional
   type categories for Windows drsyms.
 - Ported the drinjectlib and drconfiglib libraries to Linux.  Routines that
   are still Windows-only are marked in the API docs.
 - Added dr_inject_prepare_to_exec() on Linux
 - Added drsym_free_resources()
 - Added drsym_module_has_symbols()
 - Added a type_id field to drsym_info_t (without compatibility changes)
 - Added drsym_enumerate_symbols_ex() and drsym_search_symbols_ex() which
   return drsym_info_t on each symbol
 - Added dr_exit_process() to cleanly shut down with a specified
   exit code
 - Added dr_convert_handle_to_pid()
 - Added dr_nudge_client_ex() to enable nudging other processes
   from within a client
 - Added reg_resize_to_opsz()
 - Added dr_save_arith_flags_to_xax() and dr_restore_arith_flags_from_xax()
 - Added dr_snwprintf() and dr_vsnwprintf()
 - Added drwrap_replace_native(), drwrap_is_replaced(),
   drwrap_is_replaced_native()
 - Added dr_clobber_retaddr_after_read()
 - Added dr_get_string_option() and dr_get_integer_option() to support querying
   arbitrary DynamoRIO runtime options
 - Added support for building with Visual Studio 2010 and with MSBuild
 - Added instr_is_near_ubr() and instr_is_near_call_direct()
 - Added exported CMake cross-platform assembly support in
   cpp2asm_support.cmake and auxiliary files
 - Added get_DynamoRIO_defines() to DynamoRIOConfig.cmake
 - Added DR_EMIT_MUST_END_TRACE flag
 - Improved the performance of dr_safe_read() such that it out-performs
   DR_TRY_EXCEPT and no longer invokes a system call on Windows.
 - Added dr_redirect_native_target()
 - Added dr_mark_safe_to_suspend()
 - Added dr_mutex_mark_as_app(), dr_rwlock_mark_as_app(), and
   dr_recurlock_mark_as_app()
 - Added dr_get_main_module()
 - Added module import iterators dr_module_import_iterator_start(),
   dr_module_import_iterator_hasnext() dr_module_import_iterator_next(),
   dr_module_import_iterator_stop(), dr_symbol_import_iterator_start(),
   dr_symbol_import_iterator_hasnext(), dr_symbol_import_iterator_next(), and
   dr_symbol_import_iterator_stop().
 - Added DR_FAST_IR to allow clients to inline some key IR routines
 - Added -logdir runtime option for control over the log directory
 - Added drmgr_get_parent_cls_field()
 - Added support for building DynamoRIO with Visual Studio 2012 and
   the Windows 8 WDK
 - Added a new operand type enabling an instr_t to be used as a
   memory reference: opnd_create_mem_instr(), opnd_is_mem_instr(),
   opnd_get_mem_instr_disp()
 - Added DYNAMORIO_CONFIGDIR alternative to HOME as a config dir location.
   Additionally, drrun uses a temp dir for config files rather than failing.
 - Added library search path control via the client_basename.drpath file
 - Added drmgr_register_pre_syscall_event_ex()
 - Added DR_MEMPROT_GUARD for dr_memory_protect (Windows only).
 - Added dr_sscanf()
 - Added notifications on application faults and additional information
   on client faults
 - Added conversion between UTF-16 and UTF-8 to dr_snprintf() and
   dr_snwprintf()
 - Added simplified -c client argument form to drrun, drconfig, and drinject.
 - Added official support for the \ref op_speed "-opt_speed" option
   to prioritize speed over a simple code stream.
 - Added dr_atomic_add32_return_sum()
 - Deprecated dr_save_arith_flags() and dr_restore_arith_flags()
 - Fixed performance regression involving inlined clean calls
 - Fixed bug involving 32-bit Linux support on a 64-bit Linux
   kernel on an AVX-enabled processor (Issue 754)
 - Fixed bug involving multimedia state on a 32-bit Windows kernel
   (Issue 139)
 - Fixed bugs building and running on Ubuntu 11.10 (Issue 718, Issue 720)
 - Several other bug fixes
 - Added dr_raw_mem_alloc() and dr_raw_mem_free(). However, they are still
   experimental, are in flux, and are subject to change in the next release.

**************************************************
<hr>
The changes between version 3.2.0 and 3.1.0 are:

 - Added support for PECOFF + DWARF2 symbols on Windows in the
   drsyms Extension
 - Added support for building extensions as static libraries (subject to
   licensing constraints) via DR_EXT_{DRWRAP,DRUTIL,DRMGR,DRSYMS}_STATIC
 - Added support for linking C clients with libc via DynamoRIO_USE_LIBC
 - Added dr_insert_clean_call_ex()
 - Added a no-frills drwrap mode for faster but constrained wrapping
 - Added drwrap_get_drcontext() for performance
 - Added drwrap notification on exceptions bypassing post-hooks
 - Added drwrap_wrap_ex() to pass initial constant user data
 - Added drwrap_is_wrapped() and drwrap_is_post_wrap()
 - Added drwrap_set_global_flags() to control safety of
   application memory accesses
 - Added drwrap_get_mcontext_ex() to avoid the cost of copying
   multimedia register values when not necessary
 - Added drwrap interface for caching post-call addresses
 - Added drmgr_decode_sysnum_from_wrapper()
 - Added drutil_expand_rep_string_ex() that returns additional
   information about string loop expansion
 - Added improved instrlist disassembly that includes labels and
   instruction targets
 - Added instr_compute_address_ex_pos() for instrs with multiple memory
   operands.
 - Added dr_get_client_base()
 - Added dr_vsnprintf()
 - Added service pack version to dr_get_os_version()
 - Added mediation of note fields to drmgr
 - Added custom storage in label instructions via instr_get_label_data_area()
 - Added support for multiple non-meta control transfer instructions
   with intra-block targets in one basic block to drmgr
 - Added user data passing support among all four passes of drmgr
 - Several bug fixes

**************************************************
<hr>
Version 3.0.0 was a development version.  3.1.0 is the first official
released version of the 3.x series.

The changes between version 3.0.0 and 2.2.0 include the following major
features:

 - Added a private loader on Linux for better support for C++ clients and
   third-party library usage by clients
 - Added Linux support for \p drsyms to enable symbol processing in
   Linux clients
 - Added \p drutil Extension which provides memory address retrieval
   and string loop expansion (note: LGPL license)
 - Added a static library for decoding and encoding

\b IMPORTANT: The 3.0.0 and onward client API is mostly backward
compatible with releases from 1.0.0 (originally called 0.9.6: see below)
onward with the exception of functions that involve dr_mcontext_t and
several other source and binary compatibility changes since version 2.2.0
described below.  The dr_mcontext_t struct and all structs that contain it
have changed and are NOT backward compatible with releases prior to 3.0.0.

A sample script for updating client sources to the 3.0.0 API's version of
dr_mcontext_t and related functions is as follows:

\code
perl -pi -e '\
s|dr_mcontext_t (\w+);|dr_mcontext_t \1 = {sizeof(\1),DR_MC_ALL,};|;\
s|(dr_[gs]et_mcontext\(\S+,\s+\S+),\s+[^\s\)]+\)|\1)|;\
s|(dr_redirect_execution\(\S+),\s+\S+\)|\1)|;\
s|^\s+int app_errno;\s*\n||ms;\
s|raw_mcontext\.|raw_mcontext->|g;\
s|info->mcontext\.|info->mcontext->|g;\
s|excpt->mcontext\.|excpt->mcontext->|g;' *.c
\endcode

The script makes 3 main changes.  First, any dr_mcontext_t allocated by the
client must have its \p size and \p flags fields set.  Second, the \p app_errno
parameter was removed from several functions; it required a local variable,
so any local named \p app_errno is removed.  Third, the dr_mcontext_t
fields in the fault, signal, and exception structs all became
pointers.

This script may not catch all cases.  Use your version control system to
look at the diff after applying it to ensure it did not change anything it
shouldn't have.  Run with debug build to catch other instances where
dr_mcontext_t.size is not set.  Also note that using the dr_mcontext_t
initialization syntax in the script will end up calling memset; for
performance-critical situations, instead initialize only the size and flags
fields separately.  Also note that if the xmm or ymm registers are not
needed, asking for DR_MC_CONTROL and/or DR_MC_INTEGER is more performant
than DR_MC_ALL.

\b IMPORTANT: Further changes between version 3.0.0 and 2.2.0 include the following that
affect source and/or binary compatibilty:

 - Changed the #dr_mcontext_t structure field layout.  This is a binary
   compatibility change with respect to versions prior to 3.0.0.
 - Added a dr_mcontext_t.size field which must be set by the client prior
   to calling dr_get_mcontext(), dr_set_mcontext(), or
   dr_redirect_execution.  This is a source compatibility change with
   respect to versions prior to 3.0.0.
 - Added a dr_mcontext_t.flags field which must be set by the client prior
   to calling dr_get_mcontext(), dr_set_mcontext(), or
   dr_redirect_execution.  This is a source compatibility change with
   respect to versions prior to 3.0.0.
 - Removed the app_errno parameter from dr_get_mcontext(),
   dr_set_mcontext(), and dr_redirect_execution().  This is a source
   compatibility change with respect to versions prior to 3.0.0.
 - Changed all dr_mcontext_t fields in the dr_restore_state_info_t,
   dr_exception_t, and dr_siginfo_t structs to be pointers.  This is a
   source compatibility change with respect to versions prior to 3.0.0.
 - Changed the bool typedef from int to char for C++ compatibility.
   This is a binary compatibility change with respect to versions
   prior to 3.0.0.
 - Changed the signature of drwrap_unwrap(), in order to allow one of the
   pre or post hooks to be optional (Issue 562).  This is a source
   compatibility change with respect to versions prior to 3.0.0.
 - Moved console printing support from the drsyms Extension to core DR.  The
   drsym_write_to_console() and drsym_using_console() are no longer
   supported.  Instead, call dr_enable_console_printing() in dr_init(),
   which then enables dr_printf() and dr_fprintf() to print to the console
   (with some limitations: see dr_enable_console_printing() documentation).
   This is a source compatibility change with respect to versions
   prior to 3.0.0.
 - Added a \p flags argument to most of the routines in the \p drsyms extension
   to control demangling, and added drsym_demangle_symbol().  This is a source
   compatibility change with respect to versions prior to 3.0.0.
 - Added drsym_get_module_debug_kind() and a \p debug_kind field to the \p
   drsym_info_t struct written by drsym_lookup_address().  These additions allow
   drsyms users to determine what kind of debug info is available for a module.
   The \p debug_kind field creates a binary compatibility change for users of \p
   drsym_info_t with respect to versions prior to 3.0.0.

Additional changes between version 3.0.0 and 2.2.0 include the following:

 - Added \p drvector to drcontainers Extension: simple resizable vector
 - Added a windbg script for auto-locating libraries for easier
   debugging
 - Added dr_mutex_self_owns() and recursive lock support (dr_recurlock_*)
   (Issue 219)
 - Added dr_map_file(), dr_unmap_file(), and dr_file_size() (Issue 542)
 - Added dr_rename_file() and dr_delete_file().
 - Added routines to disassemble to a buffer rather than a file (Issue 524)
 - Added support for the AVX and FMA ISA extensions
 - Added dr_insert_get_seg_base()
 - Added return value to dr_redirect_execution() and dr_set_mcontext()
 - Increased maximum option string from 512 to 2048 (Issue 363)
 - Increased default stack size from 20KB to 56KB to make it easier to use
   C++ and external libraries with larger stack usage
 - Added dr_get_os_version() (Issue 304)
 - Deprecated the "meta-instruction that can fault" property and
   instr_is_meta_may_fault(), instr_set_meta_may_fault(),
   instrlist_meta_fault_preinsert(), instrlist_meta_fault_postinsert(),
   and instrlist_meta_fault_append().
 - Added dr_using_app_state()
 - Added instr_encode_to_copy() and instrlist_encode_to_copy()
 - Added disassemble_set_syntax() for -syntax_intel control without
   runtime options and proc_set_vendor() to control vendor-specific
   ISA details when decoding or encoding
 - Added instrlist_set_fall_through_target() and
   instrlist_set_return_target()
 - Added hashtable_clear() to the drcontainers Extension
 - Several bug fixes

**************************************************
<hr>
The changes between version 2.2.0 and 2.1.0 are:

 - Added \p drwrap Extension which provides function wrapping
   and replacing (note: LGPL license)
 - Added \p drmgr Extension: the DynamoRIO Multi-Instrumentation Manager
   Extension, a mediator for combining and coordinating multiple
   instrumentation passes
 - Added read-write locks (Issue 406)
 - Added isolation of client-opened files from the application (Issue 357)
 - Added dr_mcontext_t.xip for syscall events (Issue 442)
 - Several bug fixes

**************************************************
<hr>
The changes between version 2.1.0 and 2.0.0 are:

 - Added Windows 7 support
 - Added clean call sequence optimization and auto-inlining.
 - Added Windows child process following support for clients: -follow_children
   is now on by default for both Windows and Linux.
 - Added DR_TRY_EXCEPT() (Issue 51)
 - Added dynamic client auxiliary library loading support
   via dr_load_aux_library(), dr_lookup_aux_library_routine(), and
   dr_unload_aux_library()
 - Added dr_switch_to_app_state() and dr_switch_to_dr_state()
 - Added dr_client_thread_set_suspendable()
 - Added dr_get_random_value(), dr_set_random_seed(), and dr_get_random_seed()
 - Added dr_file_exists() and dr_directory_exists() for Linux
 - Added support for dr_get_mcontext() from secondary thread init events,
   and changed its return type to bool
 - Added dynamic hashtable resizing to the drcontainers hashtable
 - Added dr_app_pc_from_cache_pc()
 - Added a segment list to module_data_t for Linux and internal
   support for non-contiguously-mapped modules (Issue 160)
 - Added PEB isolation (Issue 249) and dr_get_app_PEB()
 - Added drsym_enumerate_symbols() to the \p drsyms Extension
 - Added limited support for printing to the cmd window (Issue 261) via the
   \p drsyms Extension: drsym_write_to_console() and drsym_using_console()
 - Renamed the REG_ constants to DR_REG_ to avoid conflicts with system
   headers (Issue 34).  Clients should set(DynamoRIO_REG_COMPATIBILITY ON)
   prior to configure_DynamoRIO_client() to use the old constants and avoid
   any source changes; this will happen automatically if the client
   targets version 2.0 or earlier.  Binary compatibility is unaffected.
 - Deprecated dr_request_synchronized_exit() and replaced it with
   dr_set_process_exit_behavior().  Now a full thread synch is performed
   at exit time in release build if a process exit event or thread exit
   event is registered.  dr_set_process_exit_behavior() can provide
   more performant exit performance for clients that have flexible
   exit event requirements.
 - Switched debug build to also be an INTERNAL=ON build
 - Fixed bug in handling single-byte-bb selfmod code
 - Fixed bugs in handling alarm signals
 - Fixed 64-bit Windows stack alignment bug (Issue 331)
 - Fixed handling of "data32 rex.w call"
 - Fixed Issue 320: a problem with thread-private cache resizing
 - Fixed Issue 319: decode movlhps and movhlps properly
 - Fixed Issue 139: add xmm0-7 preservation for 32-bit Linux applications,
   which may have noticeable impacts on clients calling clean calls:
   e.g., pushing bbs over the max size limit or having a noticeable
   performance hit.
 - Support building sources using Visual Studio

**************************************************
<hr>
In version 2.0.0, the configuration and deployment API and tools changed and
are not backward compatible with earlier versions: see below for details.
The changes between version 2.0.0 and 1.5.0 are:

 - Changed the configuration and deployment model for both Linux and
   Windows to use a configuration file based approach on both platforms,
   which adds control over child processes on Linux and supports local
   configuration on Windows for un-privileged and parallel execution
   (Issue 265).  The registry is no longer used for individual application
   configuration on Windows other than to point at the location for
   global configuration files, when used.<br>
   \b IMPORTANT: On Windows the following non-backward-compatible changes
   have been made:
   - drdeploy.exe no longer exists (replaced by drconfig.exe and drrun.exe)
   - drconfig.dll is now drconfiglib.dll
   - drconfiglib.dll's API routines now take in a process id to support
     one-time targeted-process configuration (to support parallel execution)
   - configuration is either per-user or global, with per-user taking
     precedence when both exist
   - configuration does NOT enable systemwide injection by default:
     use the -syswide_on parameter to drconfig or drrun for that
     (it requires administrative privileges)

   \b IMPORTANT: On Linux, if you're using custom injection via
   raw environment variables rather than using the \p drdeploy script,
   you must also set DYNAMORIO_RUNUNDER to 1 for injection to work with
   this release.
 - Added drinjectlib.dll and dr_inject.h, making custom injection tools
   easier to build (Issue 246)
 - Added DynamoRIO Extension support for auxiliary libraries that extend the
   DynamoRIO API (Issue 277)
 - Added symbol lookup support via Extension (Windows only for now) (Issue 44)
 - Added a "drcontainers" Extension that initially contains a hashtable
 - Added thread creation support: dr_create_client_thread() (Issue 41)
 - Added dr_sleep()
 - Added dr_set_itimer() and dr_get_itimer() (Linux-only) (Issue 283)
 - Added dr_app_pc_for_decoding()
 - Added -synch_at_exit option and dr_request_synchronized_exit() to
   provide guarantees over thread exit event timing in release build
 - Added instr_cmovcc_triggered() and instr_cmovcc_to_jcc()
 - Renamed OP_fcmovene to OP_fcmovne
 - Implemented instr_invert_cbr() for OP_jcc_short
 - Added the full path to modules in module_data_t
 - Added dr_get_proc_address_ex() to support indirect code objects
 - Added dr_get_milliseconds() and dr_get_time() impl for Linux
 - Added instr_is_undefined()

**************************************************
<hr>
The changes between version 1.5.0 and 1.4.0 are:

 - Added a private loader on Windows for better support for library usage
   by clients
 - Added nudge support on Linux
 - Added dr_suspend_all_other_threads() and dr_resume_all_other_threads()
 - Made it easier for clients to use faults to push rare events out of
   instrumentation paths:
   - Added access to the pre-translated context and the code fragment
     information for both
     dr_register_signal_event() and dr_register_exception_event()
     This changed the return type for exception event callbacks.
   - Added a signal/exception event on a fault in non-code-cache
     DynamoRIO code, such as client-generated code.
   - Added the "meta-instruction that can fault" property via
     instr_is_meta_may_fault(), instr_set_meta_may_fault(),
     instrlist_meta_fault_preinsert(), instrlist_meta_fault_postinsert(),
     and instrlist_meta_fault_append().
   - Added a new event dr_register_restore_state_ex_event() that provides
     the pre-translated context and code fragment information, and allows
     for translation failure for non-fault translations.
 - Added dr_dup_file_handle()
 - Added dr_memory_is_dr_internal() and dr_memory_is_in_client()
 - Added dr_get_parent_id()
 - Added decode_opcode_name()
 - Removed the deprecated snprintf() as it causes symbol pre-emption
   problems on Linux.  Older clients should switch to dr_snprintf().
 - Fixed bug in cross-architecture execve (Issue 146)
 - Clone record is now passed via dstack instead of ebp (Issue 149)
 - Fixed close() syscall handling, !HAVE_TLS assert & minor issues (Issue 151)

**************************************************
<hr>
The changes between version 1.4.0 and 1.3.2 are:

 - Added directly-addressable thread-local storage slots for exclusive
   client use:
   - dr_raw_tls_calloc()
   - dr_raw_tls_cfree()
 - Provide 64-bit versions of the drdeploy.exe and drview.exe tools
 - Provide dr_get_proc_address() on Linux
 - Added dr_query_memory_ex() to allow address space walking on Linux
 - Added -msgbox_mask on Linux: waits for a keypress
   - Added STDIN and dr_get_stdin_file()
 - Added shared library versioning on Linux
 - Support calling dr_get_mcontext() from bb and trace callbacks
 - Provide support for building clients using CMake (see cmake/, and for
   an example of usage see samples/CMakeLists.txt)
 - Provide support for clients to use -fvisibility by setting
   the define USE_VISIBILITY_ATTRIBUTES for dr_defines.h
 - Added instr_compute_address_ex() for instrs with multiple memory operands
 - Provide dr_snprintf() (identical to snprintf()) for consistent naming
   and to avoid gcc warnings about using pointers with %x (which we're
   using because there is no portable way to precisely control %p)
 - The statistics viewer \c DRgui.exe is no longer supported on Windows
   NT.  Statistics still work, but the graphical application itself will
   not run on NT.
 - Changed the top-level registry key to "DynamoRIO"
 - Re-arranged layout of bin and samples directories
 - Symbols for all binaries are now included

**************************************************
<hr>
The changes between version 1.3.2 and 1.3.1 are:

 - Added support for Linux execve of cross-architectural executables
   (e.g., 32-bit process performing execve of 64-bit executable)
   - Also, libdrpreload.so is now kept in the same libXX/{debug,release}
     directory as libdynamorio.so
 - instr_convert_short_meta_jmp_to_long() now returns the longer version of
   the taken jump, to use when setting the target of a jecxz or loop*
   branch.
 - Various bug fixes including in these areas:
   - dr_syscall_set_result() and dr_syscall_invoke_another()
   - 64-bit drinject stack alignment
   - 64-bit erroneous assert in dr_get_process_id()
   - 64-bit dr_file_{tell,seek} worked but returned failure
   - -opt_memory bugs resulting in asserts
   - sigprocmask() corner case bug
   - signal handler sharing for NPTL threads
   - decoding across page boundaries on Linux

**************************************************
<hr>
Version 1.3.1 is identical to 1.3.0 but is under a BSD license (see \ref
page_license).

We re-numbered the previous DynamoRIO versions as follows:

 - 1.0.0 = 0.9.6 build 9600
 - 1.1.0 = 0.9.6 build 9601
 - 1.2.0 = 0.9.6 build 9602

**************************************************
<hr>
The changes between version 1.3.0 and version 1.2.0 (0.9.6 9602) are:

 - Version numbering shift to 1.x.y instead of 0.9.6 960x
 - New system call pre, post, and filter events, and new system call
   parameter and result access, along with a feature to chain system calls:
   - dr_register_pre_syscall_event()
   - dr_register_post_syscall_event()
   - dr_register_filter_syscall_event()
   - dr_syscall_get_param()
   - dr_syscall_set_param()
   - dr_syscall_set_sysnum()
   - dr_syscall_get_result()
   - dr_syscall_set_result()
   - dr_syscall_invoke_another()
   - dr_is_wow64()
 - New signal event for Linux
   - dr_register_signal_event()
 - New option "-pause_on_error", and error messages to
   stdout by default for release builds, to improve Linux debugging
 - New routines for memory allocation and memory manipulation:
   - dr_nonheap_alloc()
   - dr_nonheap_free()
   - dr_memory_protect()
 - New option \ref op_syntax_intel "-syntax_intel" for Intel-style disassembly
 - New option \ref op_sysenter "-sysenter_is_int80"
 - The parameter to an application's system call (normally kept in the eax
   register) can now be freely changed in basic blocks on all platforms
 - Added support for 64-bit -thread_private
 - Added corner-case undocumented IA-32 opcode support
 - Fixed bug running multi-threaded 64-bit Linux apps
 - Fixed bugs in 64-bit Linux signal handling
 - Fixed bug running -thread_private debug build
 - Fixed bug running 32-bit apps on 64-bit Linux on AMD processors
 - Fixed bug where OS_OPEN_APPEND overwrote instead of appending on Windows

**************************************************
<hr>
The changes between the 0.9.6 release builds 9602 and 9601 are:

 - Performance improvements for both the base DynamoRIO system and for
   client instrumentation when running on Pentium M, Core, and Core 2
   processors.
 - 64-bit bug fixes
 - Added several convenience routines:
   - get_register_name()
   - reg_to_pointer_sized()
   - reg_is_gpr()
   - reg_is_segment()
   - reg_32_to_8()
 - Disassembly now expands immed sizes to match operands
 - Fixed bug in instr_is_nop()

**************************************************
<hr>
The changes between the 0.9.6 release builds 9601 and 9600 are:

 - The Windows registry key used is now "VMware, Inc." instead of "VMware"
 - Added large file support (see #DR_FILE_ALLOW_LARGE)
 - Added support for decoding from a copy of code: decode_from_copy() and
   disassemble_from_copy().
 - Changed the default options to favor performance, and added the
   \ref op_memory "-opt_memory" runtime option to prioritize memory instead.

Release 0.9.6 is \b not backward compatible with prior releases 0.9.1-0.9.5.

The major changes between the 0.9.6 and 0.9.5 releases include 64-bit
support, multiple clients, state translation, trace contents, and Linux
module events and fast system calls:

 - 64-bit applications and clients are now supported.  This changed
   several function signatures:
   - instr_encode()
   - decode_next_pc()
   - decode_sizeof()
   - decode_eflags_usage()
   - instr_init()
   - The binary trace dump format changed.
   .
   Several new functions were added:
   - set_x86_mode()
   - get_x86_mode()
   - instr_set_x86_mode()
   - instr_get_x86_mode()
   - opnd_create_rel_addr()
   - opnd_create_far_rel_addr()
   - opnd_is_rel_addr()
   - opnd_is_near_rel_addr()
   - opnd_is_far_rel_addr()
   - instr_has_rel_addr_reference()
   - instr_get_rel_addr_target()
   - instr_get_rel_addr_dst_idx()
   - instr_get_rel_addr_src_idx()
   - instr_shrink_to_32_bits()
   - opnd_shrink_to_32_bits()
   - reg_32_to_64()
   - reg_64_to_32()
   - reg_is_extended()
   - reg_parameter_num()
   .
   To build a 64-bit client, set the \p X86_64 preprocessor define before
   including the DynamoRIO header files, and link with the 64-bit build of
   DynamoRIO (for a 32-bit client, set \p X86_32).
 - Multiple clients are now supported.  This changed the signatures of
   dr_init(), dr_get_options(), and dr_get_client_path().  It also changed
   how clients are deployed and nudged, and how events are unregistered:
   explicit unregistration routines are now used.
 - State translation in the presence of clients is now fully supported.
   This changed the signature for the basic block and trace event callbacks
   (see dr_register_bb_event() and dr_register_trace_event()), added a
   new event dr_register_restore_state_event(), and added new functions
   instr_set_translation(), instr_set_meta_no_translation(), and INSTR_XL8().
 - The trace callback (#dr_register_trace_event()) now presents original
   application code to the client, rather than code that has already
   been modified for execution in the code cache.  The client also has
   flexibility in which instrumentation is included from constituent
   basic blocks added to a trace (the \p for_trace parameter: see
   #dr_register_bb_event()).
 - Fast system calls (syscall and sysenter) are now supported on Linux.
 - Module load/unload events and module iteration are now supported on Linux.
 - System calls for 32-bit applications on 64-bit kernels are no longer
   hidden by vsyscall; related functions were removed:
   instr_is_lol64_syscall(), instr_is_32on64_syscall().
 - Due to both 64-bit support and full WOW64 (32-bit applications on 64-bit
   Windows) support, xmm registers were added to dr_mcontext_t, and a
   new function dr_mcontext_xmm_fields_valid() was added.
 - Far instr-type operands are now supported: opnd_create_far_instr(),
   opnd_is_near_instr(), opnd_is_far_instr().
 - Miscellaneous new functions were added:
   - instr_convert_short_meta_jmp_to_long()
   - instr_reads_from_reg()
   - LOCK()
   - OPND_CREATE_INT_32OR8()
   - OPND_CREATE_INT_16OR8()
   - instrlist_meta_append()
   - dr_using_all_private_caches()
 - The type of nudge arguments was changed from (void *) to uint64.
 - The signature of dr_lookup_module() changed.  It no longer has an
   IMAGE_SECTION_HEADER out argument.  See dr_lookup_module_section()
   for that functionality.
 - The disassemble-from-address routines now return NULL when pointed at
   invalid instructions (matching the decode routines).
 - The routines to access DynamoRIO tls slots from the cache were changed.
   dr_insert_write_temp_tls was eliminated in favor of a generalized #dr_save_reg
   with more flexibility on which slot can be used.  #dr_save_arith_flags was
   similarly generalized.  Slots are now guaranteed to remain valid until the
   next non-meta instruction allowing access to saved registers during clean
   calls via #dr_read_saved_reg and #dr_write_saved_reg.  #dr_insert_mbr_instrumentation
   also now requires caller to specify the spill slot to be clobbered
   which must be less than dr_max_opnd_accessible_spill_slot().

**************************************************
<hr>
The major changes between the 0.9.5 and 0.9.4 releases are:

 - The basic block hook (\ref sec_events_bb) passes completely unmodified
   application code to the client (no mangling or elision).
 - The old client hook exports have been replaced with an explicit event
   registration model.
 - Instruction representation simplification: the client only sees fully
   decoded instructions.
 - Easier-to-use clean calls (see #dr_insert_clean_call).
 - Library support (-wrap on linux, ntdll on windows: see \ref sec_extlibs
   and \ref sec_utils).
 - Some features have been removed (these are easily implemented by a
   client): there is no more edge-counting profile build, no more
   custom exit stubs, and no more prefixes.
 - Infrastructure improvements:
   - Thread-shared caches (can still request thread-private: \ref
     op_thread_priv "-thread_private option").  Note that there are
     some subtle changes stemming from using thread-shared: in particular,
     note that the context passed to the deletion event may be NULL
     (see #dr_register_delete_event).
   - Direct access to TLS slots (#dr_save_reg, dr_insert_write_temp_tls,
     #dr_insert_write_tls_field).
 - Module events (#dr_register_module_load_event),
   module iteration (#dr_module_iterator_start, #dr_lookup_module, etc.),
   and memory querying (#dr_query_memory, #dr_virtual_query).
 - The full API is now documented in html and pdf for easy browsing.
 - Numerous type and routine name changes.


***************************************************************************
\htmlonly
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  <tr><td><table width=100% bgcolor="#0000C0" cellspacing=0 cellpadding=1 border=0>
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\endhtmlonly
\section sec_limits Limitations

\subsection sec_limit_clients Client Limitations
The most important limitation on a client is that it remain transparent.
This is described fully in \ref transparency.
Here we summarize the key points to remain transparent:

  - For full transparency, the client should be a self-contained library
with linkage to nothing other than DynamoRIO libraries.  We
provide private loading that makes some use of system libraries safe, but
global resource conflicts can still occur and clients are cautioned from
using system-interacting library routines.
See \ref sec_extlibs for further details.
  - Currently, the communication API provided by DynamoRIO is limited to file
I/O and nudges.

\subsection sec_limit_platforms Platform Limitations
  - This version of DynamoRIO supports Windows 8, 8.1, and 10.
    However, systemwide injection (-syswide_on) is not yet supported on
    Windows 8 or higher except for WOW64 (i.e., 32-bit applications on
    a 64-bit kernel).
  - DynamoRIO currently supports the following NT-based 32-bit
    Windows systems: XP (32-bit, service packs 0-3), 2003 (32-bit, service
    packs 0-2), Vista (32-bit, service packs 0-1),
    Windows 7 (32-bit, service packs 0-1), Windows 8, Windows 8.1, and
    Windows 10.
    It does not support Windows 95, 98, or ME.
    It no longer officially supports NT (all service packs) or 2000 (all service
    packs), although the core DynamoRIO library should still work there: it
    is only the tools and utility programs that will fail to run.
    Windows Server 2008 is expected to work but has not
    been tested.
  - This release of DynamoRIO supports running 32-bit
    Windows applications on the following 64-bit Windows operating
    systems: Windows XP Professional x64 (service pack 2), Windows 2003
    x64 (service pack 2), Vista x64 (service packs 0-1), Windows 7
    (service packs 0-1), Windows Server 2008, Windows 8, Windows 8.1, and
    Windows 10.
    Only the 32-bit
    code will be seen, and child processes created will not be injected
    into.  On 64-bit Windows 32-bit applications are automatically run
    through the Windows-On-Windows or WOW64 emulator so system call and
    indirect call processing clients must be aware of
    #instr_is_wow64_syscall().
  - On all versions of Windows, attaching DynamoRIO to an already-running
    process can result in loss of control if the attach point is in the
    middle of an operating system event callback. From the callback return
    point until the next system call hook, no instructions will be observed
    by a client.
\anchor limits_64bit
  - This release of DynamoRIO supports running
    64-bit Windows applications, using the 64-bit DynamoRIO build, on
    the following 64-bit Windows systems: Windows XP Professional x64
    (service pack 2), Windows 2003
    x64 (service pack 2), Vista x64 (service packs 0-1), Windows 7 x64
    (service packs 0-1), Windows 8, Windows 8.1, and Windows 10.
    Windows Server 2008 is expected to work but has not
    been tested.
  - DynamoRIO does not support any Itanium based Windows systems.
  - This release does not fully support applications that mix 32-bit and
    64-bit code.  Future releases will support such mixtures.
  - When running a cygwin application under control of DynamoRIO,
    stderr and stdout output from DynamoRIO or its clients may not
    be visible.
  - UTF-8 support is not yet present in drinjectlib, drconfiglib,
    drrun.exe, drconfig.exe, or drinject.exe.  It is present in the
    core DR API.
  - This release of DynamoRIO has support for most 32-bit and
    64-bit Linux
    distributions running on Intel-compatible hardware, including
    Ubuntu and Fedora.
  - This release of DynamoRIO has support for running 32-bit
    Linux applications on 64-bit Linux operating systems on
    AMD64-compatible hardware.
  - Cross-architecture execve (e.g., a 32-bit process performing execve of
    a 64-bit executable) may stop working if the paths to the
    libdynamorio.so and libdrpreload.so libraries are renamed.
  - This release of DynamoRIO supports 32-bit applications running on
    32-bit Linux operating systems on AArch32 ARMv7 and ARMv8 hardware.
    However, a few features are not yet ported: traces, clean
    call inlining and other optimizations, and several samples.
  - This release of DynamoRIO has experimental support for 32-bit Android
    applications running on AArch32 ARMv7 and ARMv8 hardware.
    However, a few features are not yet ported: traces, clean
    call inlining and other optimizations, and several samples.
  - This release of DynamoRIO has experimental support for 64-bit
    applications running on 64-bit Linux operating systems on AArch64 ARMv8
    hardware.  However, floating-point and SIMD instruction operands are
    not fully decoded or encoded yet, and a few features are not yet
    ported: traces, clean call inlining and other optimizations, and
    several samples and provided tools.
  - This release of DynamoRIO includes support for applications using the Linux kernel
    restartable sequence ("rseq") feature, subject to the limitations listed
    in \ref sec_rseq.

\subsection sec_limit_perf Performance Limitations

  - In order to present a more straightforward code stream to clients,
    DynamoRIO has several optimizations disabled in this release.
    System-call-heavy applications are the ones most likely to be affected.
    Future releases may allow clients to choose performance versus
    visibility.  This release does provide the \ref op_memory "-opt_memory option"
    to enable prioritizing memory usage and the \ref op_speed "-opt_speed option"
    to prioritize performance at the cost of more complex basic blocks that
    cross control transfers.
  - The performance when starting up large desktop applications
    may be noticeably worse than native.  Upcoming releases will
    address this issue.
  - The performance when
    running  Java, .Net, Flash or similar managed execution
    applications can be noticeably worse then native.  This can
    include applications that load these components as in-process
    plugins (such as Internet Explorer). Upcoming releases will
    address this issue.
  - When using DynamoRIO on all or many processes on a system
    simultaneously, memory usage may become a factor.  Upcoming
    releases will address this issue.

\subsection sec_limit_deploy Deployment Limitations

  - The dr_config.lib library is not multi-thread safe.  Users of the
    library should ensure that no more then one thread accesses the
    library at a time.
  - Other installed software that uses hooks may not always be
    interoperable with DynamoRIO.
  - Other installed software may conflict with DynamoRIO's use of the
    \c \\HKLM\\SOFTWARE\\Microsoft\\Windows\\WindowsNT\\CurrentVersion\\AppInit_DLLs
    registry key (only very rarely an issue), which is used for
    the -syswide_on feature.
  - On Windows, the Enhanced Mitigation Experience Toolkit (EMET) may prevent
    applications from running under DynamoRIO
    (<a href="https://github.com/dynamorio/dynamorio/issues/1546">issue 1546</a>).
    Please disable EMET for the application if necessary.
  - On Windows 7 and Windows Server 2008 R2, the digital signature
    requirement for AppInit_DLLs libraries is disabled when systemwide
    injection is requested (-syswide_on).  This can be a security concern.
  - On Windows 8 or 8.1, system wide injection (-syswide_on) is not yet supported.
  - Cygwin processes may not work with DynamoRIO due to cygwin's
    implementation of fork being incompatible with DynamoRIO.
  - A Windows application that does not statically link with
    user32.dll will not be run under control of DynamoRIO using
    system-wide injection unless its
    parent process (typically cmd.exe or explorer.exe, for manually
    launched applications) is already under DynamoRIO control.  Only some small
    non-graphical applications do not link with user32.dll.
  - When invoking an application in any way that is not from a parent
    process under DynamoRIO control, DynamoRIO takes control a little
    later and in some rare cases the application has already created a new
    thread.  This is in violation of the Windows specficiations, but cygwin
    processes do this.  This new thread will not be under DynamoRIO
    control and can cause a variety of problems.  In such cases it is best
    to invoke from a parent process under DynamoRIO control.  However, for
    32-bit applications on 64-bit Windows operating systems, DynamoRIO
    takes over later even from the parent.  Future releases will address
    this limitation.
  - This release does not support running some Windows services under
    control of DynamoRIO: the "System" process, smss.exe, csrss.exe, and protected
    processes on Windows Vista.

\anchor limits_vista_service_messagebox
  - On Windows Vista most services are run in a separate session as a
    security feature.  This means that neither DynamoRIO nor its
    client will be able to display a messagebox when running in said
    services (they have no associated visible window station). See
    dr_messagebox().
  - On Windows Vista the code from
    certain dlls (found mostly in services) and the code subsequently
    called from those dlls is run natively and is not visible to the
    instrumentation APIs.  This only applies to dlls that have a .pexe
    section (only 13 dlls have such a section in a standard Vista
    install) which seems to be associated with a likely obfuscation
    method involving kernel side components that this release has no
    other workaround for.
\anchor limits_linux_preload
  - On Linux, non-default late injection (requested via \p -late to drrun)
    is unable to run binaries with the suid or sgid permission bits set.
    Default injection is capable of executing these binaries, but if late
    injection is desired, one method of running these binaries
    is to place both libdrpreload.so and libdynamorio's full paths in
    /etc/ld.so.preload.
    You'll need to use a \ref sec_lin_deploy "separate configure step approach".
    Don't forget to run drconfig to create a configuration for the
    application first; otherwise, libdrpreload.so will refuse to take
    control.  This method of injection takes control part-way through
    initialization of the target application, rather than at the very
    beginning.  Alternatively, you could run as root, or remove the suid
    and sgid bits: however, both of those solutions may open up security
    holes and are not recommended.  If the suid or sgid binary is a leaf
    child process of the parent target application, another option is to
    run the problematic child process natively by either creating a configuration
    file for the child with the "-norun" parameter or running with the
    \ref op_children "-no_follow_children" runtime option.
  - On Linux, the private loader will fail to load libpthread.so.  Therefore
    clients and the libraries they use cannot link against libpthread.so.

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\section sec_future Plans for Future Releases

We hope to include the following major features in future releases:

 - Libraries to facilitate building tools that use shadow memory, examine
   system calls, and insert heavyweight instrumentation.
 - Earliest Windows injection.  Today drinject injects fairly late; from a
   parent process, injection is very early (before kernel32.dll is loaded),
   but we plan to provide injection at the very first user-mode instruction
   in the future.
 - Persistent and process-shared code caches.
 - Full control over trace building.

To discuss current and future features, join the <a
href="http://groups.google.com/group/dynamorio-users/">DynamoRIO Users
group</a>.

*/