What has changed in GDB?
(Organized release by release)
-*** Changes since GDB 6.7
+*** Changes since GDB 6.8
+
+* GDB now has an interface for JIT compilation. Applications that
+dynamically generate code can create symbol files in memory and register
+them with GDB. For users, the feature should work transparently, and
+for JIT developers, the interface is documented in the GDB manual in the
+"JIT Compilation Interface" chapter.
+
+* Tracepoints may now be conditional. The syntax is as for
+breakpoints; either an "if" clause appended to the "trace" command,
+or the "condition" command is available. GDB sends the condition to
+the target for evaluation using the same bytecode format as is used
+for tracepoint actions.
+
+* "disassemble" command with a /r modifier, print the raw instructions
+in hex as well as in symbolic form."
+
+* Process record and replay
+
+ In a architecture environment that supports ``process record and
+ replay'', ``process record and replay'' target can record a log of
+ the process execution, and replay it with both forward and reverse
+ execute commands.
+
+* Reverse debugging: GDB now has new commands reverse-continue, reverse-
+step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
+set execution-direction {forward|reverse}, for targets that support
+reverse execution.
+
+* GDB now supports hardware watchpoints on MIPS/Linux systems. This
+feature is available with a native GDB running on kernel version
+2.6.28 or later.
+
+* GDB now has support for multi-byte and wide character sets on the
+target. Strings whose character type is wchar_t, char16_t, or
+char32_t are now correctly printed. GDB supports wide- and unicode-
+literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
+U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
+`printf'. This feature requires iconv to work properly; if your
+system does not have a working iconv, GDB can use GNU libiconv. See
+the installation instructions for more information.
+
+* GDB now supports automatic retrieval of shared library files from
+remote targets. To use this feature, specify a system root that begins
+with the `remote:' prefix, either via the `set sysroot' command or via
+the `--with-sysroot' configure-time option.
+
+* "info sharedlibrary" now takes an optional regex of libraries to show,
+and it now reports if a shared library has no debugging information.
+
+* Commands `set debug-file-directory', `set solib-search-path' and `set args'
+now complete on file names.
+
+* When completing in expressions, gdb will attempt to limit
+completions to allowable structure or union fields, where appropriate.
+For instance, consider:
+
+ # struct example { int f1; double f2; };
+ # struct example variable;
+ (gdb) p variable.
+
+If the user types TAB at the end of this command line, the available
+completions will be "f1" and "f2".
+
+* Inlined functions are now supported. They show up in backtraces, and
+the "step", "next", and "finish" commands handle them automatically.
+
+* GDB now supports the token-splicing (##) and stringification (#)
+operators when expanding macros. It also supports variable-arity
+macros.
+
+* GDB now supports inspecting extra signal information, exported by
+the new $_siginfo convenience variable. The feature is currently
+implemented on linux ARM, i386 and amd64.
+
+* GDB can now display the VFP floating point registers and NEON vector
+registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
+can provide these registers (requires Linux 2.6.30 or later). Remote
+and simulator targets may also provide them.
-*** Changes in GDB 6.6
+* New remote packets
+
+qSearch:memory:
+ Search memory for a sequence of bytes.
+
+QStartNoAckMode
+ Turn off `+'/`-' protocol acknowledgments to permit more efficient
+ operation over reliable transport links. Use of this packet is
+ controlled by the `set remote noack-packet' command.
+
+vKill
+ Kill the process with the specified process ID. Use this in preference
+ to `k' when multiprocess protocol extensions are supported.
+
+qXfer:osdata:read
+ Obtains additional operating system information
+
+qXfer:siginfo:read
+qXfer:siginfo:write
+ Read or write additional signal information.
+
+* Removed remote protocol undocumented extension
+
+ An undocumented extension to the remote protocol's `S' stop reply
+ packet that permited the stub to pass a process id was removed.
+ Remote servers should use the `T' stop reply packet instead.
+
+* The "disassemble" command now supports an optional /m modifier to print mixed
+source+assembly.
+
+* GDB now supports multiple function calling conventions according to the
+DWARF-2 DW_AT_calling_convention function attribute.
+
+* The SH target utilizes the aforementioned change to distinguish between gcc
+and Renesas calling convention. It also adds the new CLI commands
+`set/show sh calling-convention'.
+
+* GDB can now read compressed debug sections, as produced by GNU gold
+with the --compress-debug-sections=zlib flag.
+
+* 64-bit core files are now supported on AIX.
+
+* Thread switching is now supported on Tru64.
+
+* Watchpoints can now be set on unreadable memory locations, e.g. addresses
+which will be allocated using malloc later in program execution.
+
+* The qXfer:libraries:read remote procotol packet now allows passing a
+list of section offsets.
+
+* On GNU/Linux, GDB can now attach to stopped processes. Several race
+conditions handling signals delivered during attach or thread creation
+have also been fixed.
+
+* GDB now supports the use of DWARF boolean types for Ada's type Boolean.
+From the user's standpoint, all unqualified instances of True and False
+are treated as the standard definitions, regardless of context.
+
+* GDB now parses C++ symbol and type names more flexibly. For
+example, given:
+
+ template<typename T> class C { };
+ C<char const *> c;
+
+GDB will now correctly handle all of:
+
+ ptype C<char const *>
+ ptype C<char const*>
+ ptype C<const char *>
+ ptype C<const char*>
+
+* New features in the GDB remote stub, gdbserver
+
+ - The "--wrapper" command-line argument tells gdbserver to use a
+ wrapper program to launch programs for debugging.
+
+ - On PowerPC and S/390 targets, it is now possible to use a single
+ gdbserver executable to debug both 32-bit and 64-bit programs.
+ (This requires gdbserver itself to be built as a 64-bit executable.)
+
+ - gdbserver uses the new noack protocol mode for TCP connections to
+ reduce communications latency, if also supported and enabled in GDB.
+
+ - Support for the sparc64-linux-gnu target is now included in
+ gdbserver.
+
+ - The amd64-linux build of gdbserver now supports debugging both
+ 32-bit and 64-bit programs.
+
+ - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
+ now support hardware watchpoints, and will use them automatically
+ as appropriate.
+
+* Python scripting
+
+ GDB now has support for scripting using Python. Whether this is
+ available is determined at configure time.
+
+ New GDB commands can now be written in Python.
+
+* Ada tasking support
+
+ Ada tasks can now be inspected in GDB. The following commands have
+ been introduced:
+
+ info tasks
+ Print the list of Ada tasks.
+ info task N
+ Print detailed information about task number N.
+ task
+ Print the task number of the current task.
+ task N
+ Switch the context of debugging to task number N.
+
+* Support for user-defined prefixed commands. The "define" command can
+add new commands to existing prefixes, e.g. "target".
+
+* Multi-inferior, multi-process debugging.
+
+ GDB now has generalized support for multi-inferior debugging. See
+ "Debugging Multiple Inferiors" in the manual for more information.
+ Although availability still depends on target support, the command
+ set is more uniform now. The GNU/Linux specific multi-forks support
+ has been migrated to this new framework. This implied some user
+ visible changes; see "New commands" and also "Removed commands"
+ below.
+
+* Target descriptions can now describe the target OS ABI. See the
+"Target Description Format" section in the user manual for more
+information.
+
+* Target descriptions can now describe "compatible" architectures
+to indicate that the target can execute applications for a different
+architecture in addition to those for the main target architecture.
+See the "Target Description Format" section in the user manual for
+more information.
+
+* Multi-architecture debugging.
+
+ GDB now includes general supports for debugging applications on
+ hybrid systems that use more than one single processor architecture
+ at the same time. Each such hybrid architecture still requires
+ specific support to be added. The only hybrid architecture supported
+ in this version of GDB is the Cell Broadband Engine.
+
+* GDB now supports integrated debugging of Cell/B.E. applications that
+use both the PPU and SPU architectures. To enable support for hybrid
+Cell/B.E. debugging, you need to configure GDB to support both the
+powerpc-linux or powerpc64-linux and the spu-elf targets, using the
+--enable-targets configure option.
+
+* New commands (for set/show, see "New options" below)
+
+find [/size-char] [/max-count] start-address, end-address|+search-space-size,
+ val1 [, val2, ...]
+ Search memory for a sequence of bytes.
+
+maint set python print-stack
+maint show python print-stack
+ Show a stack trace when an error is encountered in a Python script.
+
+python [CODE]
+ Invoke CODE by passing it to the Python interpreter.
+
+macro define
+macro list
+macro undef
+ These allow macros to be defined, undefined, and listed
+ interactively.
+
+info os processes
+ Show operating system information about processes.
+
+info inferiors
+ List the inferiors currently under GDB's control.
+
+inferior NUM
+ Switch focus to inferior number NUM.
+
+detach inferior NUM
+ Detach from inferior number NUM.
+
+kill inferior NUM
+ Kill inferior number NUM.
+
+* New options
+
+set spu stop-on-load
+show spu stop-on-load
+ Control whether to stop for new SPE threads during Cell/B.E. debugging.
+
+set spu auto-flush-cache
+show spu auto-flush-cache
+ Control whether to automatically flush the software-managed cache
+ during Cell/B.E. debugging.
+
+set sh calling-convention
+show sh calling-convention
+ Control the calling convention used when calling SH target functions.
+
+set debug timestamp
+show debug timestamp
+ Control display of timestamps with GDB debugging output.
+
+set disassemble-next-line
+show disassemble-next-line
+ Control display of disassembled source lines or instructions when
+ the debuggee stops.
+
+set remote noack-packet
+show remote noack-packet
+ Set/show the use of remote protocol QStartNoAckMode packet. See above
+ under "New remote packets."
+
+set remote query-attached-packet
+show remote query-attached-packet
+ Control use of remote protocol `qAttached' (query-attached) packet.
+
+set remote read-siginfo-object
+show remote read-siginfo-object
+ Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
+ packet.
+
+set remote write-siginfo-object
+show remote write-siginfo-object
+ Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
+ packet.
+
+set displaced-stepping
+show displaced-stepping
+ Control displaced stepping mode. Displaced stepping is a way to
+ single-step over breakpoints without removing them from the debuggee.
+ Also known as "out-of-line single-stepping".
+
+set debug displaced
+show debug displaced
+ Control display of debugging info for displaced stepping.
+
+maint set internal-error
+maint show internal-error
+ Control what GDB does when an internal error is detected.
+
+maint set internal-warning
+maint show internal-warning
+ Control what GDB does when an internal warning is detected.
+
+set exec-wrapper
+show exec-wrapper
+unset exec-wrapper
+ Use a wrapper program to launch programs for debugging.
+
+set multiple-symbols (all|ask|cancel)
+show multiple-symbols
+ The value of this variable can be changed to adjust the debugger behavior
+ when an expression or a breakpoint location contains an ambiguous symbol
+ name (an overloaded function name, for instance).
+
+set breakpoint always-inserted
+show breakpoint always-inserted
+ Keep breakpoints always inserted in the target, as opposed to inserting
+ them when resuming the target, and removing them when the target stops.
+ This option can improve debugger performance on slow remote targets.
+
+set arm fallback-mode (arm|thumb|auto)
+show arm fallback-mode
+set arm force-mode (arm|thumb|auto)
+show arm force-mode
+ These commands control how ARM GDB determines whether instructions
+ are ARM or Thumb. The default for both settings is auto, which uses
+ the current CPSR value for instructions without symbols; previous
+ versions of GDB behaved as if "set arm fallback-mode arm".
+
+set disable-randomization
+show disable-randomization
+ Standalone programs run with the virtual address space randomization enabled
+ by default on some platforms. This option keeps the addresses stable across
+ multiple debugging sessions.
+
+set non-stop
+show non-stop
+ Control whether other threads are stopped or not when some thread hits
+ a breakpoint.
+
+set target-async
+show target-async
+ Requests that asynchronous execution is enabled in the target, if available.
+ In this case, it's possible to resume target in the background, and interact
+ with GDB while the target is running. "show target-async" displays the
+ current state of asynchronous execution of the target.
+
+set target-wide-charset
+show target-wide-charset
+ The target-wide-charset is the name of the character set that GDB
+ uses when printing characters whose type is wchar_t.
+
+set tcp auto-retry (on|off)
+show tcp auto-retry
+set tcp connect-timeout
+show tcp connect-timeout
+ These commands allow GDB to retry failed TCP connections to a remote stub
+ with a specified timeout period; this is useful if the stub is launched
+ in parallel with GDB but may not be ready to accept connections immediately.
+
+set libthread-db-search-path
+show libthread-db-search-path
+ Control list of directories which GDB will search for appropriate
+ libthread_db.
+
+set schedule-multiple (on|off)
+show schedule-multiple
+ Allow GDB to resume all threads of all processes or only threads of
+ the current process.
+
+set stack-cache
+show stack-cache
+ Use more aggressive caching for accesses to the stack. This improves
+ performance of remote debugging (particularly backtraces) without
+ affecting correctness.
+
+* Removed commands
+
+info forks
+ For program forks, this is replaced by the new more generic `info
+ inferiors' command. To list checkpoints, you can still use the
+ `info checkpoints' command, which was an alias for the `info forks'
+ command.
+
+fork NUM
+ Replaced by the new `inferior' command. To switch between
+ checkpoints, you can still use the `restart' command, which was an
+ alias for the `fork' command.
+
+process PID
+ This is removed, since some targets don't have a notion of
+ processes. To switch between processes, you can still use the
+ `inferior' command using GDB's own inferior number.
+
+delete fork NUM
+ For program forks, this is replaced by the new more generic `kill
+ inferior' command. To delete a checkpoint, you can still use the
+ `delete checkpoint' command, which was an alias for the `delete
+ fork' command.
+
+detach fork NUM
+ For program forks, this is replaced by the new more generic `detach
+ inferior' command. To detach a checkpoint, you can still use the
+ `detach checkpoint' command, which was an alias for the `detach
+ fork' command.
+
+* New native configurations
+
+x86/x86_64 Darwin i[34567]86-*-darwin*
+
+x86_64 MinGW x86_64-*-mingw*
+
+* New targets
+
+Lattice Mico32 lm32-*
+x86 DICOS i[34567]86-*-dicos*
+x86_64 DICOS x86_64-*-dicos*
+S+core 3 score-*-*
+
+* The GDB remote stub, gdbserver, now supports x86 Windows CE
+ (mingw32ce) debugging.
+
+* Removed commands
+
+catch load
+catch unload
+ These commands were actually not implemented on any target.
+
+*** Changes in GDB 6.8
+
+* New native configurations
+
+NetBSD/hppa hppa*-*netbsd*
+Xtensa GNU/Linux xtensa*-*-linux*
+
+* New targets
+
+NetBSD/hppa hppa*-*-netbsd*
+Xtensa GNU/Lunux xtensa*-*-linux*
+
+* Change in command line behavior -- corefiles vs. process ids.
+
+ When the '-p NUMBER' or '--pid NUMBER' options are used, and
+ attaching to process NUMBER fails, GDB no longer attempts to open a
+ core file named NUMBER. Attaching to a program using the -c option
+ is no longer supported. Instead, use the '-p' or '--pid' options.
+
+* GDB can now be built as a native debugger for debugging Windows x86
+(mingw32) Portable Executable (PE) programs.
+
+* Pending breakpoints no longer change their number when their address
+is resolved.
+
+* GDB now supports breakpoints with multiple locations,
+including breakpoints on C++ constructors, inside C++ templates,
+and in inlined functions.
+
+* GDB's ability to debug optimized code has been improved. GDB more
+accurately identifies function bodies and lexical blocks that occupy
+more than one contiguous range of addresses.
+
+* Target descriptions can now describe registers for PowerPC.
+
+* The GDB remote stub, gdbserver, now supports the AltiVec and SPE
+registers on PowerPC targets.
+
+* The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
+targets even when the libthread_db library is not available.
+
+* The GDB remote stub, gdbserver, now supports the new file transfer
+commands (remote put, remote get, and remote delete).
+
+* The GDB remote stub, gdbserver, now supports run and attach in
+extended-remote mode.
+
+* hppa*64*-*-hpux11* target broken
+The debugger is unable to start a program and fails with the following
+error: "Error trying to get information about dynamic linker".
+The gdb-6.7 release is also affected.
+
+* GDB now supports the --enable-targets= configure option to allow
+building a single GDB executable that supports multiple remote
+target architectures.
+
+* GDB now supports debugging C and C++ programs which use the
+Decimal Floating Point extension. In addition, the PowerPC target
+now has a set of pseudo-registers to inspect decimal float values
+stored in two consecutive float registers.
+
+* The -break-insert MI command can optionally create pending
+breakpoints now.
+
+* Improved support for debugging Ada
+Many improvements to the Ada language support have been made. These
+include:
+ - Better support for Ada2005 interface types
+ - Improved handling of arrays and slices in general
+ - Better support for Taft-amendment types
+ - The '{type} ADDRESS' expression is now allowed on the left hand-side
+ of an assignment
+ - Improved command completion in Ada
+ - Several bug fixes
+
+* GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
+process.
+
+* New commands
+
+set print frame-arguments (all|scalars|none)
+show print frame-arguments
+ The value of this variable can be changed to control which argument
+ values should be printed by the debugger when displaying a frame.
+
+remote put
+remote get
+remote delete
+ Transfer files to and from a remote target, and delete remote files.
+
+* New MI commands
+
+-target-file-put
+-target-file-get
+-target-file-delete
+ Transfer files to and from a remote target, and delete remote files.
+
+* New remote packets
+
+vFile:open:
+vFile:close:
+vFile:pread:
+vFile:pwrite:
+vFile:unlink:
+ Open, close, read, write, and delete files on the remote system.
+
+vAttach
+ Attach to an existing process on the remote system, in extended-remote
+ mode.
+
+vRun
+ Run a new process on the remote system, in extended-remote mode.
+
+*** Changes in GDB 6.7
* Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
bfd, libiberty and opcodes, as revealed by static analysis donated by
* Target descriptions can now describe target-specific registers,
for architectures which have implemented the support (currently
-only ARM and MIPS).
+only ARM, M68K, and MIPS).
* GDB and the GDB remote stub, gdbserver, now support the XScale
iWMMXt coprocessor.