1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.10
6 * Record btrace now supports non-stop mode.
8 * Support for tracepoints on aarch64-linux was added in GDBserver.
10 * The 'record instruction-history' command now indicates speculative execution
11 when using the Intel(R) Processor Trace recording format.
13 * GDB now allows users to specify explicit locations, bypassing
14 the linespec parser. This feature is also available to GDB/MI
17 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
18 GDB now is able to debug both AArch64 applications and ARM applications
21 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
22 including JIT compiling fast tracepoint's conditional expression bytecode
25 * GDB now supports displaced stepping on AArch64 GNU/Linux.
29 maint set target-non-stop (on|off|auto)
30 maint show target-non-stop
31 Control whether GDB targets always operate in non-stop mode even if
32 "set non-stop" is "off". The default is "auto", meaning non-stop
33 mode is enabled if supported by the target.
36 maint show bfd-sharing
37 Control the reuse of bfd objects.
41 Control display of debugging info regarding bfd caching.
43 set remote multiprocess-extensions-packet
44 show remote multiprocess-extensions-packet
45 Set/show the use of the remote protocol multiprocess extensions.
47 * The "disassemble" command accepts a new modifier: /s.
48 It prints mixed source+disassembly like /m with two differences:
49 - disassembled instructions are now printed in program order, and
50 - and source for all relevant files is now printed.
51 The "/m" option is now considered deprecated: its "source-centric"
52 output hasn't proved useful in practice.
54 * The "record instruction-history" command accepts a new modifier: /s.
55 It behaves exactly like /m and prints mixed source+disassembly.
57 * The "set scheduler-locking" command supports a new mode "replay".
58 It behaves like "off" in record mode and like "on" in replay mode.
60 * Support for various ROM monitors has been removed:
62 target dbug dBUG ROM monitor for Motorola ColdFire
63 target picobug Motorola picobug monitor
64 target dink32 DINK32 ROM monitor for PowerPC
65 target m32r Renesas M32R/D ROM monitor
66 target mon2000 mon2000 ROM monitor
67 target ppcbug PPCBUG ROM monitor for PowerPC
69 * Support for reading/writing memory and extracting values on architectures
70 whose memory is addressable in units of any integral multiple of 8 bits.
75 Indicates that an exec system call was executed.
77 exec-events feature in qSupported
78 The qSupported packet allows GDB to request support for exec
79 events using the new 'gdbfeature' exec-event, and the qSupported
80 response can contain the corresponding 'stubfeature'. Set and
81 show commands can be used to display whether these features are enabled.
83 * Extended-remote exec events
85 ** GDB now has support for exec events on extended-remote Linux targets.
86 For such targets with Linux kernels 2.5.46 and later, this enables
87 follow-exec-mode and exec catchpoints.
89 set remote exec-event-feature-packet
90 show remote exec-event-feature-packet
91 Set/show the use of the remote exec event feature.
93 *** Changes in GDB 7.10
95 * Support for process record-replay and reverse debugging on aarch64*-linux*
96 targets has been added. GDB now supports recording of A64 instruction set
97 including advance SIMD instructions.
99 * Support for Sun's version of the "stabs" debug file format has been removed.
101 * GDB now honors the content of the file /proc/PID/coredump_filter
102 (PID is the process ID) on GNU/Linux systems. This file can be used
103 to specify the types of memory mappings that will be included in a
104 corefile. For more information, please refer to the manual page of
105 "core(5)". GDB also has a new command: "set use-coredump-filter
106 on|off". It allows to set whether GDB will read the content of the
107 /proc/PID/coredump_filter file when generating a corefile.
109 * The "info os" command on GNU/Linux can now display information on
111 "info os cpus" Listing of all cpus/cores on the system
113 * GDB has two new commands: "set serial parity odd|even|none" and
114 "show serial parity". These allows to set or show parity for the
117 * The "info source" command now displays the producer string if it was
118 present in the debug info. This typically includes the compiler version
119 and may include things like its command line arguments.
121 * The "info dll", an alias of the "info sharedlibrary" command,
122 is now available on all platforms.
124 * Directory names supplied to the "set sysroot" commands may be
125 prefixed with "target:" to tell GDB to access shared libraries from
126 the target system, be it local or remote. This replaces the prefix
127 "remote:". The default sysroot has been changed from "" to
128 "target:". "remote:" is automatically converted to "target:" for
129 backward compatibility.
131 * The system root specified by "set sysroot" will be prepended to the
132 filename of the main executable (if reported to GDB as absolute by
133 the operating system) when starting processes remotely, and when
134 attaching to already-running local or remote processes.
136 * GDB now supports automatic location and retrieval of executable
137 files from remote targets. Remote debugging can now be initiated
138 using only a "target remote" or "target extended-remote" command
139 (no "set sysroot" or "file" commands are required). See "New remote
142 * The "dump" command now supports verilog hex format.
144 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
146 * On GNU/Linux, GDB and gdbserver are now able to access executable
147 and shared library files without a "set sysroot" command when
148 attaching to processes running in different mount namespaces from
149 the debugger. This makes it possible to attach to processes in
150 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
151 See "New remote packets" below.
153 * The "tui reg" command now provides completion for all of the
154 available register groups, including target specific groups.
156 * The HISTSIZE environment variable is no longer read when determining
157 the size of GDB's command history. GDB now instead reads the dedicated
158 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
159 disables truncation of command history. Non-numeric values of GDBHISTSIZE
164 ** Memory ports can now be unbuffered.
168 ** gdb.Objfile objects have a new attribute "username",
169 which is the name of the objfile as specified by the user,
170 without, for example, resolving symlinks.
171 ** You can now write frame unwinders in Python.
172 ** gdb.Type objects have a new method "optimized_out",
173 returning optimized out gdb.Value instance of this type.
174 ** gdb.Value objects have new methods "reference_value" and
175 "const_value" which return a reference to the value and a
176 "const" version of the value respectively.
180 maint print symbol-cache
181 Print the contents of the symbol cache.
183 maint print symbol-cache-statistics
184 Print statistics of symbol cache usage.
186 maint flush-symbol-cache
187 Flush the contents of the symbol cache.
191 Start branch trace recording using Branch Trace Store (BTS) format.
194 Evaluate expression by using the compiler and print result.
198 Explicit commands for enabling and disabling tui mode.
201 set mpx bound on i386 and amd64
202 Support for bound table investigation on Intel(R) MPX enabled applications.
206 Start branch trace recording using Intel(R) Processor Trace format.
209 Print information about branch tracing internals.
211 maint btrace packet-history
212 Print the raw branch tracing data.
214 maint btrace clear-packet-history
215 Discard the stored raw branch tracing data.
218 Discard all branch tracing data. It will be fetched and processed
219 anew by the next "record" command.
224 Renamed from "set debug dwarf2-die".
226 Renamed from "show debug dwarf2-die".
229 Renamed from "set debug dwarf2-read".
230 show debug dwarf-read
231 Renamed from "show debug dwarf2-read".
233 maint set dwarf always-disassemble
234 Renamed from "maint set dwarf2 always-disassemble".
235 maint show dwarf always-disassemble
236 Renamed from "maint show dwarf2 always-disassemble".
238 maint set dwarf max-cache-age
239 Renamed from "maint set dwarf2 max-cache-age".
240 maint show dwarf max-cache-age
241 Renamed from "maint show dwarf2 max-cache-age".
244 show debug dwarf-line
245 Control display of debugging info regarding DWARF line processing.
249 Set the maximum number of candidates to be considered during
250 completion. The default value is 200. This limit allows GDB
251 to avoid generating large completion lists, the computation of
252 which can cause the debugger to become temporarily unresponsive.
254 set history remove-duplicates
255 show history remove-duplicates
256 Control the removal of duplicate history entries.
258 maint set symbol-cache-size
259 maint show symbol-cache-size
260 Control the size of the symbol cache.
262 set|show record btrace bts buffer-size
263 Set and show the size of the ring buffer used for branch tracing in
265 The obtained size may differ from the requested size. Use "info
266 record" to see the obtained buffer size.
268 set debug linux-namespaces
269 show debug linux-namespaces
270 Control display of debugging info regarding Linux namespaces.
272 set|show record btrace pt buffer-size
273 Set and show the size of the ring buffer used for branch tracing in
274 Intel(R) Processor Trace format.
275 The obtained size may differ from the requested size. Use "info
276 record" to see the obtained buffer size.
278 maint set|show btrace pt skip-pad
279 Set and show whether PAD packets are skipped when computing the
282 * The command 'thread apply all' can now support new option '-ascending'
283 to call its specified command for all threads in ascending order.
285 * Python/Guile scripting
287 ** GDB now supports auto-loading of Python/Guile scripts contained in the
288 special section named `.debug_gdb_scripts'.
292 qXfer:btrace-conf:read
293 Return the branch trace configuration for the current thread.
295 Qbtrace-conf:bts:size
296 Set the requested ring buffer size for branch tracing in BTS format.
299 Enable Intel(R) Procesor Trace-based branch tracing for the current
300 process. The remote stub reports support for this packet to GDB's
304 Set the requested ring buffer size for branch tracing in Intel(R) Processor
308 Indicates a memory breakpoint instruction was executed, irrespective
309 of whether it was GDB that planted the breakpoint or the breakpoint
310 is hardcoded in the program. This is required for correct non-stop
314 Indicates the target stopped for a hardware breakpoint. This is
315 required for correct non-stop mode operation.
318 Return information about files on the remote system.
321 Return the full absolute name of the file that was executed to
322 create a process running on the remote system.
325 Select the filesystem on which vFile: operations with filename
326 arguments will operate. This is required for GDB to be able to
327 access files on remote targets where the remote stub does not
328 share a common filesystem with the inferior(s).
331 Indicates that a fork system call was executed.
334 Indicates that a vfork system call was executed.
336 vforkdone stop reason
337 Indicates that a vfork child of the specified process has executed
338 an exec or exit, allowing the vfork parent to resume execution.
340 fork-events and vfork-events features in qSupported
341 The qSupported packet allows GDB to request support for fork and
342 vfork events using new 'gdbfeatures' fork-events and vfork-events,
343 and the qSupported response can contain the corresponding
344 'stubfeatures'. Set and show commands can be used to display
345 whether these features are enabled.
347 * Extended-remote fork events
349 ** GDB now has support for fork events on extended-remote Linux
350 targets. For targets with Linux kernels 2.5.60 and later, this
351 enables follow-fork-mode and detach-on-fork for both fork and
352 vfork, as well as fork and vfork catchpoints.
354 * The info record command now shows the recording format and the
355 branch tracing configuration for the current thread when using
356 the btrace record target.
357 For the BTS format, it shows the ring buffer size.
359 * GDB now has support for DTrace USDT (Userland Static Defined
360 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
362 * GDB now supports access to vector registers on S/390 GNU/Linux
365 * Removed command line options
367 -xdb HP-UX XDB compatibility mode.
369 * Removed targets and native configurations
371 HP/PA running HP-UX hppa*-*-hpux*
372 Itanium running HP-UX ia64-*-hpux*
374 * New configure options
377 This configure option allows the user to build GDB with support for
378 Intel(R) Processor Trace (default: auto). This requires libipt.
380 --with-libipt-prefix=PATH
381 Specify the path to the version of libipt that GDB should use.
382 $PATH/include should contain the intel-pt.h header and
383 $PATH/lib should contain the libipt.so library.
385 *** Changes in GDB 7.9.1
389 ** Xmethods can now specify a result type.
391 *** Changes in GDB 7.9
393 * GDB now supports hardware watchpoints on x86 GNU Hurd.
397 ** You can now access frame registers from Python scripts.
398 ** New attribute 'producer' for gdb.Symtab objects.
399 ** gdb.Objfile objects have a new attribute "progspace",
400 which is the gdb.Progspace object of the containing program space.
401 ** gdb.Objfile objects have a new attribute "owner".
402 ** gdb.Objfile objects have a new attribute "build_id",
403 which is the build ID generated when the file was built.
404 ** gdb.Objfile objects have a new method "add_separate_debug_file".
405 ** A new event "gdb.clear_objfiles" has been added, triggered when
406 selecting a new file to debug.
407 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
408 ** New function gdb.lookup_objfile.
410 New events which are triggered when GDB modifies the state of the
413 ** gdb.events.inferior_call_pre: Function call is about to be made.
414 ** gdb.events.inferior_call_post: Function call has just been made.
415 ** gdb.events.memory_changed: A memory location has been altered.
416 ** gdb.events.register_changed: A register has been altered.
418 * New Python-based convenience functions:
420 ** $_caller_is(name [, number_of_frames])
421 ** $_caller_matches(regexp [, number_of_frames])
422 ** $_any_caller_is(name [, number_of_frames])
423 ** $_any_caller_matches(regexp [, number_of_frames])
425 * GDB now supports the compilation and injection of source code into
426 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
427 to compile the source code to object code, and if successful, inject
428 and execute that code within the current context of the inferior.
429 Currently the C language is supported. The commands used to
430 interface with this new feature are:
432 compile code [-raw|-r] [--] [source code]
433 compile file [-raw|-r] filename
437 demangle [-l language] [--] name
438 Demangle "name" in the specified language, or the current language
439 if elided. This command is renamed from the "maint demangle" command.
440 The latter is kept as a no-op to avoid "maint demangle" being interpreted
441 as "maint demangler-warning".
443 queue-signal signal-name-or-number
444 Queue a signal to be delivered to the thread when it is resumed.
446 add-auto-load-scripts-directory directory
447 Add entries to the list of directories from which to load auto-loaded
450 maint print user-registers
451 List all currently available "user" registers.
453 compile code [-r|-raw] [--] [source code]
454 Compile, inject, and execute in the inferior the executable object
455 code produced by compiling the provided source code.
457 compile file [-r|-raw] filename
458 Compile and inject into the inferior the executable object code
459 produced by compiling the source code stored in the filename
462 * On resume, GDB now always passes the signal the program had stopped
463 for to the thread the signal was sent to, even if the user changed
464 threads before resuming. Previously GDB would often (but not
465 always) deliver the signal to the thread that happens to be current
468 * Conversely, the "signal" command now consistently delivers the
469 requested signal to the current thread. GDB now asks for
470 confirmation if the program had stopped for a signal and the user
471 switched threads meanwhile.
473 * "breakpoint always-inserted" modes "off" and "auto" merged.
475 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
476 won't remove breakpoints from the target until all threads stop,
477 even in non-stop mode. The "auto" mode has been removed, and "off"
478 is now the default mode.
482 set debug symbol-lookup
483 show debug symbol-lookup
484 Control display of debugging info regarding symbol lookup.
488 ** The -list-thread-groups command outputs an exit-code field for
489 inferiors that have exited.
493 MIPS SDE mips*-sde*-elf*
497 Support for these obsolete configurations has been removed.
499 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
500 SGI Irix-5.x mips-*-irix5*
501 SGI Irix-6.x mips-*-irix6*
502 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
503 VAX running Ultrix vax-*-ultrix*
505 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
506 and "assf"), have been removed. Use the "sharedlibrary" command, or
507 its alias "share", instead.
509 *** Changes in GDB 7.8
511 * New command line options
514 This is an alias for the --data-directory option.
516 * GDB supports printing and modifying of variable length automatic arrays
517 as specified in ISO C99.
519 * The ARM simulator now supports instruction level tracing
520 with or without disassembly.
524 GDB now has support for scripting using Guile. Whether this is
525 available is determined at configure time.
526 Guile version 2.0 or greater is required.
527 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
529 * New commands (for set/show, see "New options" below)
533 Invoke CODE by passing it to the Guile interpreter.
537 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
539 info auto-load guile-scripts [regexp]
540 Print the list of automatically loaded Guile scripts.
542 * The source command is now capable of sourcing Guile scripts.
543 This feature is dependent on the debugger being built with Guile support.
547 set print symbol-loading (off|brief|full)
548 show print symbol-loading
549 Control whether to print informational messages when loading symbol
550 information for a file. The default is "full", but when debugging
551 programs with large numbers of shared libraries the amount of output
554 set guile print-stack (none|message|full)
555 show guile print-stack
556 Show a stack trace when an error is encountered in a Guile script.
558 set auto-load guile-scripts (on|off)
559 show auto-load guile-scripts
560 Control auto-loading of Guile script files.
562 maint ada set ignore-descriptive-types (on|off)
563 maint ada show ignore-descriptive-types
564 Control whether the debugger should ignore descriptive types in Ada
565 programs. The default is not to ignore the descriptive types. See
566 the user manual for more details on descriptive types and the intended
567 usage of this option.
569 set auto-connect-native-target
571 Control whether GDB is allowed to automatically connect to the
572 native target for the run, attach, etc. commands when not connected
573 to any target yet. See also "target native" below.
575 set record btrace replay-memory-access (read-only|read-write)
576 show record btrace replay-memory-access
577 Control what memory accesses are allowed during replay.
579 maint set target-async (on|off)
580 maint show target-async
581 This controls whether GDB targets operate in synchronous or
582 asynchronous mode. Normally the default is asynchronous, if it is
583 available; but this can be changed to more easily debug problems
584 occurring only in synchronous mode.
586 set mi-async (on|off)
588 Control whether MI asynchronous mode is preferred. This supersedes
589 "set target-async" of previous GDB versions.
591 * "set target-async" is deprecated as a CLI option and is now an alias
592 for "set mi-async" (only puts MI into async mode).
594 * Background execution commands (e.g., "c&", "s&", etc.) are now
595 possible ``out of the box'' if the target supports them. Previously
596 the user would need to explicitly enable the possibility with the
597 "set target-async on" command.
599 * New features in the GDB remote stub, GDBserver
601 ** New option --debug-format=option1[,option2,...] allows one to add
602 additional text to each output. At present only timestamps
603 are supported: --debug-format=timestamps.
604 Timestamps can also be turned on with the
605 "monitor set debug-format timestamps" command from GDB.
607 * The 'record instruction-history' command now starts counting instructions
608 at one. This also affects the instruction ranges reported by the
609 'record function-call-history' command when given the /i modifier.
611 * The command 'record function-call-history' supports a new modifier '/c' to
612 indent the function names based on their call stack depth.
613 The fields for the '/i' and '/l' modifier have been reordered.
614 The source line range is now prefixed with 'at'.
615 The instruction range is now prefixed with 'inst'.
616 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
617 "record instruction-history" and "list" commands.
619 * The ranges given as arguments to the 'record function-call-history' and
620 'record instruction-history' commands are now inclusive.
622 * The btrace record target now supports the 'record goto' command.
623 For locations inside the execution trace, the back trace is computed
624 based on the information stored in the execution trace.
626 * The btrace record target supports limited reverse execution and replay.
627 The target does not record data and therefore does not allow reading
630 * The "catch syscall" command now works on s390*-linux* targets.
632 * The "compare-sections" command is no longer specific to target
633 remote. It now works with all targets.
635 * All native targets are now consistently called "native".
636 Consequently, the "target child", "target GNU", "target djgpp",
637 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
638 commands have been replaced with "target native". The QNX/NTO port
639 leaves the "procfs" target in place and adds a "native" target for
640 consistency with other ports. The impact on users should be minimal
641 as these commands previously either throwed an error, or were
642 no-ops. The target's name is visible in the output of the following
643 commands: "help target", "info target", "info files", "maint print
646 * The "target native" command now connects to the native target. This
647 can be used to launch native programs even when "set
648 auto-connect-native-target" is set to off.
650 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.
652 * Support for Intel(R) AVX-512 registers on GNU/Linux.
653 Support displaying and modifying Intel(R) AVX-512 registers
654 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
658 qXfer:btrace:read's annex
659 The qXfer:btrace:read packet supports a new annex 'delta' to read
660 branch trace incrementally.
664 ** Valid Python operations on gdb.Value objects representing
665 structs/classes invoke the corresponding overloaded operators if
667 ** New `Xmethods' feature in the Python API. Xmethods are
668 additional methods or replacements for existing methods of a C++
669 class. This feature is useful for those cases where a method
670 defined in C++ source code could be inlined or optimized out by
671 the compiler, making it unavailable to GDB.
674 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
676 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
677 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
678 its alias "share", instead.
680 * The commands "set remotebaud" and "show remotebaud" are no longer
681 supported. Use "set serial baud" and "show serial baud" (respectively)
686 ** A new option "-gdb-set mi-async" replaces "-gdb-set
687 target-async". The latter is left as a deprecated alias of the
688 former for backward compatibility. If the target supports it,
689 CLI background execution commands are now always possible by
690 default, independently of whether the frontend stated a
691 preference for asynchronous execution with "-gdb-set mi-async".
692 Previously "-gdb-set target-async off" affected both MI execution
693 commands and CLI execution commands.
695 *** Changes in GDB 7.7
697 * Improved support for process record-replay and reverse debugging on
698 arm*-linux* targets. Support for thumb32 and syscall instruction
699 recording has been added.
701 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
703 * GDB now supports Fission DWP file format version 2.
704 http://gcc.gnu.org/wiki/DebugFission
706 * New convenience function "$_isvoid", to check whether an expression
707 is void. A void expression is an expression where the type of the
708 result is "void". For example, some convenience variables may be
709 "void" when evaluated (e.g., "$_exitcode" before the execution of
710 the program being debugged; or an undefined convenience variable).
711 Another example, when calling a function whose return type is
714 * The "maintenance print objfiles" command now takes an optional regexp.
716 * The "catch syscall" command now works on arm*-linux* targets.
718 * GDB now consistently shows "<not saved>" when printing values of
719 registers the debug info indicates have not been saved in the frame
720 and there's nowhere to retrieve them from
721 (callee-saved/call-clobbered registers):
726 (gdb) info registers rax
729 Before, the former would print "<optimized out>", and the latter
730 "*value not available*".
732 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
737 ** Frame filters and frame decorators have been added.
738 ** Temporary breakpoints are now supported.
739 ** Line tables representation has been added.
740 ** New attribute 'parent_type' for gdb.Field objects.
741 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
742 ** New attribute 'name' for gdb.Type objects.
746 Nios II ELF nios2*-*-elf
747 Nios II GNU/Linux nios2*-*-linux
748 Texas Instruments MSP430 msp430*-*-elf
750 * Removed native configurations
752 Support for these a.out NetBSD and OpenBSD obsolete configurations has
753 been removed. ELF variants of these configurations are kept supported.
755 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
756 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
757 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
758 i[34567]86-*-openbsd3.[0-3]
759 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
760 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
761 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
765 Like "catch throw", but catches a re-thrown exception.
767 Renamed from old "maint check-symtabs".
769 Perform consistency checks on symtabs.
771 Expand symtabs matching an optional regexp.
774 Display the details of GDB configure-time options.
776 maint set|show per-command
777 maint set|show per-command space
778 maint set|show per-command time
779 maint set|show per-command symtab
780 Enable display of per-command gdb resource usage.
782 remove-symbol-file FILENAME
783 remove-symbol-file -a ADDRESS
784 Remove a symbol file added via add-symbol-file. The file to remove
785 can be identified by its filename or by an address that lies within
786 the boundaries of this symbol file in memory.
789 info exceptions REGEXP
790 Display the list of Ada exceptions defined in the program being
791 debugged. If provided, only the exceptions whose names match REGEXP
796 set debug symfile off|on
798 Control display of debugging info regarding reading symbol files and
799 symbol tables within those files
801 set print raw frame-arguments
802 show print raw frame-arguments
803 Set/show whether to print frame arguments in raw mode,
804 disregarding any defined pretty-printers.
806 set remote trace-status-packet
807 show remote trace-status-packet
808 Set/show the use of remote protocol qTStatus packet.
812 Control display of debugging messages related to Nios II targets.
816 Control whether target-assisted range stepping is enabled.
818 set startup-with-shell
819 show startup-with-shell
820 Specifies whether Unix child processes are started via a shell or
825 Use the target memory cache for accesses to the code segment. This
826 improves performance of remote debugging (particularly disassembly).
828 * You can now use a literal value 'unlimited' for options that
829 interpret 0 or -1 as meaning "unlimited". E.g., "set
830 trace-buffer-size unlimited" is now an alias for "set
831 trace-buffer-size -1" and "set height unlimited" is now an alias for
834 * The "set debug symtab-create" debugging option of GDB has been changed to
835 accept a verbosity level. 0 means "off", 1 provides basic debugging
836 output, and values of 2 or greater provides more verbose output.
838 * New command-line options
840 Display the details of GDB configure-time options.
842 * The command 'tsave' can now support new option '-ctf' to save trace
843 buffer in Common Trace Format.
845 * Newly installed $prefix/bin/gcore acts as a shell interface for the
848 * GDB now implements the the C++ 'typeid' operator.
850 * The new convenience variable $_exception holds the exception being
851 thrown or caught at an exception-related catchpoint.
853 * The exception-related catchpoints, like "catch throw", now accept a
854 regular expression which can be used to filter exceptions by type.
856 * The new convenience variable $_exitsignal is automatically set to
857 the terminating signal number when the program being debugged dies
858 due to an uncaught signal.
862 ** All MI commands now accept an optional "--language" option.
863 Support for this feature can be verified by using the "-list-features"
864 command, which should contain "language-option".
866 ** The new command -info-gdb-mi-command allows the user to determine
867 whether a GDB/MI command is supported or not.
869 ** The "^error" result record returned when trying to execute an undefined
870 GDB/MI command now provides a variable named "code" whose content is the
871 "undefined-command" error code. Support for this feature can be verified
872 by using the "-list-features" command, which should contain
873 "undefined-command-error-code".
875 ** The -trace-save MI command can optionally save trace buffer in Common
878 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
880 ** The command -data-list-register-values now accepts an optional
881 "--skip-unavailable" option. When used, only the available registers
884 ** The new command -trace-frame-collected dumps collected variables,
885 computed expressions, tvars, memory and registers in a traceframe.
887 ** The commands -stack-list-locals, -stack-list-arguments and
888 -stack-list-variables now accept an option "--skip-unavailable".
889 When used, only the available locals or arguments are displayed.
891 ** The -exec-run command now accepts an optional "--start" option.
892 When used, the command follows the same semantics as the "start"
893 command, stopping the program's execution at the start of its
894 main subprogram. Support for this feature can be verified using
895 the "-list-features" command, which should contain
896 "exec-run-start-option".
898 ** The new commands -catch-assert and -catch-exceptions insert
899 catchpoints stopping the program when Ada exceptions are raised.
901 ** The new command -info-ada-exceptions provides the equivalent of
902 the new "info exceptions" command.
904 * New system-wide configuration scripts
905 A GDB installation now provides scripts suitable for use as system-wide
906 configuration scripts for the following systems:
910 * GDB now supports target-assigned range stepping with remote targets.
911 This improves the performance of stepping source lines by reducing
912 the number of control packets from/to GDB. See "New remote packets"
915 * GDB now understands the element 'tvar' in the XML traceframe info.
916 It has the id of the collected trace state variables.
918 * On S/390 targets that provide the transactional-execution feature,
919 the program interruption transaction diagnostic block (TDB) is now
920 represented as a number of additional "registers" in GDB.
926 The vCont packet supports a new 'r' action, that tells the remote
927 stub to step through an address range itself, without GDB
928 involvemement at each single-step.
930 qXfer:libraries-svr4:read's annex
931 The previously unused annex of the qXfer:libraries-svr4:read packet
932 is now used to support passing an argument list. The remote stub
933 reports support for this argument list to GDB's qSupported query.
934 The defined arguments are "start" and "prev", used to reduce work
935 necessary for library list updating, resulting in significant
938 * New features in the GDB remote stub, GDBserver
940 ** GDBserver now supports target-assisted range stepping. Currently
941 enabled on x86/x86_64 GNU/Linux targets.
943 ** GDBserver now adds element 'tvar' in the XML in the reply to
944 'qXfer:traceframe-info:read'. It has the id of the collected
945 trace state variables.
947 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
950 * New 'z' formatter for printing and examining memory, this displays the
951 value as hexadecimal zero padded on the left to the size of the type.
953 * GDB can now use Windows x64 unwinding data.
955 * The "set remotebaud" command has been replaced by "set serial baud".
956 Similarly, "show remotebaud" has been replaced by "show serial baud".
957 The "set remotebaud" and "show remotebaud" commands are still available
958 to provide backward compatibility with older versions of GDB.
960 *** Changes in GDB 7.6
962 * Target record has been renamed to record-full.
963 Record/replay is now enabled with the "record full" command.
964 This also affects settings that are associated with full record/replay
965 that have been moved from "set/show record" to "set/show record full":
967 set|show record full insn-number-max
968 set|show record full stop-at-limit
969 set|show record full memory-query
971 * A new record target "record-btrace" has been added. The new target
972 uses hardware support to record the control-flow of a process. It
973 does not support replaying the execution, but it implements the
974 below new commands for investigating the recorded execution log.
975 This new recording method can be enabled using:
979 The "record-btrace" target is only available on Intel Atom processors
980 and requires a Linux kernel 2.6.32 or later.
982 * Two new commands have been added for record/replay to give information
983 about the recorded execution without having to replay the execution.
984 The commands are only supported by "record btrace".
986 record instruction-history prints the execution history at
987 instruction granularity
989 record function-call-history prints the execution history at
992 * New native configurations
994 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
995 FreeBSD/powerpc powerpc*-*-freebsd
996 x86_64/Cygwin x86_64-*-cygwin*
997 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1001 ARM AArch64 aarch64*-*-elf
1002 ARM AArch64 GNU/Linux aarch64*-*-linux
1003 Lynx 178 PowerPC powerpc-*-lynx*178
1004 x86_64/Cygwin x86_64-*-cygwin*
1005 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1007 * If the configured location of system.gdbinit file (as given by the
1008 --with-system-gdbinit option at configure time) is in the
1009 data-directory (as specified by --with-gdb-datadir at configure
1010 time) or in one of its subdirectories, then GDB will look for the
1011 system-wide init file in the directory specified by the
1012 --data-directory command-line option.
1014 * New command line options:
1016 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1017 other initialization files, unlike -nx which disables all of them.
1019 * Removed command line options
1021 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1024 * The 'ptype' and 'whatis' commands now accept an argument to control
1027 * 'info proc' now works on some core files.
1031 ** Vectors can be created with gdb.Type.vector.
1033 ** Python's atexit.register now works in GDB.
1035 ** Types can be pretty-printed via a Python API.
1037 ** Python 3 is now supported (in addition to Python 2.4 or later)
1039 ** New class gdb.Architecture exposes GDB's internal representation
1040 of architecture in the Python API.
1042 ** New method Frame.architecture returns the gdb.Architecture object
1043 corresponding to the frame's architecture.
1045 * New Python-based convenience functions:
1047 ** $_memeq(buf1, buf2, length)
1048 ** $_streq(str1, str2)
1050 ** $_regex(str, regex)
1052 * The 'cd' command now defaults to using '~' (the home directory) if not
1055 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1056 default for GCC since November 2000.
1058 * The command 'forward-search' can now be abbreviated as 'fo'.
1060 * The command 'info tracepoints' can now display 'installed on target'
1061 or 'not installed on target' for each non-pending location of tracepoint.
1063 * New configure options
1065 --enable-libmcheck/--disable-libmcheck
1066 By default, development versions are built with -lmcheck on hosts
1067 that support it, in order to help track memory corruption issues.
1068 Release versions, on the other hand, are built without -lmcheck
1069 by default. The --enable-libmcheck/--disable-libmcheck configure
1070 options allow the user to override that default.
1071 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1072 This configure option allows the user to build GDB with
1073 libbabeltrace using which GDB can read Common Trace Format data.
1075 * New commands (for set/show, see "New options" below)
1078 Catch signals. This is similar to "handle", but allows commands and
1079 conditions to be attached.
1082 List the BFDs known to GDB.
1084 python-interactive [command]
1086 Start a Python interactive prompt, or evaluate the optional command
1087 and print the result of expressions.
1090 "py" is a new alias for "python".
1092 enable type-printer [name]...
1093 disable type-printer [name]...
1094 Enable or disable type printers.
1098 ** For the Renesas Super-H architecture, the "regs" command has been removed
1099 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1104 set print type methods (on|off)
1105 show print type methods
1106 Control whether method declarations are displayed by "ptype".
1107 The default is to show them.
1109 set print type typedefs (on|off)
1110 show print type typedefs
1111 Control whether typedef definitions are displayed by "ptype".
1112 The default is to show them.
1114 set filename-display basename|relative|absolute
1115 show filename-display
1116 Control the way in which filenames is displayed.
1117 The default is "relative", which preserves previous behavior.
1119 set trace-buffer-size
1120 show trace-buffer-size
1121 Request target to change the size of trace buffer.
1123 set remote trace-buffer-size-packet auto|on|off
1124 show remote trace-buffer-size-packet
1125 Control the use of the remote protocol `QTBuffer:size' packet.
1129 Control display of debugging messages related to ARM AArch64.
1132 set debug coff-pe-read
1133 show debug coff-pe-read
1134 Control display of debugging messages related to reading of COFF/PE
1139 Control display of debugging messages related to Mach-O symbols
1142 set debug notification
1143 show debug notification
1144 Control display of debugging info for async remote notification.
1148 ** Command parameter changes are now notified using new async record
1149 "=cmd-param-changed".
1150 ** Trace frame changes caused by command "tfind" are now notified using
1151 new async record "=traceframe-changed".
1152 ** The creation, deletion and modification of trace state variables
1153 are now notified using new async records "=tsv-created",
1154 "=tsv-deleted" and "=tsv-modified".
1155 ** The start and stop of process record are now notified using new
1156 async record "=record-started" and "=record-stopped".
1157 ** Memory changes are now notified using new async record
1159 ** The data-disassemble command response will include a "fullname" field
1160 containing the absolute file name when source has been requested.
1161 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1162 command, to allow pattern filling of memory areas.
1163 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1164 library load/unload events.
1165 ** The response to breakpoint commands and breakpoint async records
1166 includes an "installed" field containing a boolean state about each
1167 non-pending tracepoint location is whether installed on target or not.
1168 ** Output of the "-trace-status" command includes a "trace-file" field
1169 containing the name of the trace file being examined. This field is
1170 optional, and only present when examining a trace file.
1171 ** The "fullname" field is now always present along with the "file" field,
1172 even if the file cannot be found by GDB.
1174 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1175 You must have the LZMA library available when configuring GDB for this
1176 feature to be enabled. For more information, see:
1177 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1179 * New remote packets
1182 Set the size of trace buffer. The remote stub reports support for this
1183 packet to gdb's qSupported query.
1186 Enable Branch Trace Store (BTS)-based branch tracing for the current
1187 thread. The remote stub reports support for this packet to gdb's
1191 Disable branch tracing for the current thread. The remote stub reports
1192 support for this packet to gdb's qSupported query.
1195 Read the traced branches for the current thread. The remote stub
1196 reports support for this packet to gdb's qSupported query.
1198 *** Changes in GDB 7.5
1200 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1201 for more x32 ABI info.
1203 * GDB now supports access to MIPS DSP registers on Linux targets.
1205 * GDB now supports debugging microMIPS binaries.
1207 * The "info os" command on GNU/Linux can now display information on
1208 several new classes of objects managed by the operating system:
1209 "info os procgroups" lists process groups
1210 "info os files" lists file descriptors
1211 "info os sockets" lists internet-domain sockets
1212 "info os shm" lists shared-memory regions
1213 "info os semaphores" lists semaphores
1214 "info os msg" lists message queues
1215 "info os modules" lists loaded kernel modules
1217 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1218 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1219 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1220 options and inspect the probe arguments using the new $_probe_arg family
1221 of convenience variables. You can obtain more information about SystemTap
1222 in <http://sourceware.org/systemtap/>.
1224 * GDB now supports reversible debugging on ARM, it allows you to
1225 debug basic ARM and THUMB instructions, and provides
1226 record/replay support.
1228 * The option "symbol-reloading" has been deleted as it is no longer used.
1232 ** GDB commands implemented in Python can now be put in command class
1235 ** The "maint set python print-stack on|off" is now deleted.
1237 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1238 apply "flag enum"-style pretty-printing to any enum.
1240 ** gdb.lookup_symbol can now work when there is no current frame.
1242 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1243 the source at which the symbol was defined.
1245 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1246 method 'value'. The former indicates whether the symbol needs a
1247 frame in order to compute its value, and the latter computes the
1250 ** A new method 'referenced_value' on gdb.Value objects which can
1251 dereference pointer as well as C++ reference values.
1253 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1254 which return the global and static blocks (as gdb.Block objects),
1255 of the underlying symbol table, respectively.
1257 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1258 object associated with a PC value.
1260 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1261 of the address range occupied by code for the current source line.
1263 * Go language support.
1264 GDB now supports debugging programs written in the Go programming
1267 * GDBserver now supports stdio connections.
1268 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1270 * The binary "gdbtui" can no longer be built or installed.
1271 Use "gdb -tui" instead.
1273 * GDB will now print "flag" enums specially. A flag enum is one where
1274 all the enumerator values have no bits in common when pairwise
1275 "and"ed. When printing a value whose type is a flag enum, GDB will
1276 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1277 (gdb) print (enum E) 3
1280 * The filename part of a linespec will now match trailing components
1281 of a source file name. For example, "break gcc/expr.c:1000" will
1282 now set a breakpoint in build/gcc/expr.c, but not
1283 build/libcpp/expr.c.
1285 * The "info proc" and "generate-core-file" commands will now also
1286 work on remote targets connected to GDBserver on Linux.
1288 * The command "info catch" has been removed. It has been disabled
1289 since December 2007.
1291 * The "catch exception" and "catch assert" commands now accept
1292 a condition at the end of the command, much like the "break"
1293 command does. For instance:
1295 (gdb) catch exception Constraint_Error if Barrier = True
1297 Previously, it was possible to add a condition to such catchpoints,
1298 but it had to be done as a second step, after the catchpoint had been
1299 created, using the "condition" command.
1301 * The "info static-tracepoint-marker" command will now also work on
1302 native Linux targets with in-process agent.
1304 * GDB can now set breakpoints on inlined functions.
1306 * The .gdb_index section has been updated to include symbols for
1307 inlined functions. GDB will ignore older .gdb_index sections by
1308 default, which could cause symbol files to be loaded more slowly
1309 until their .gdb_index sections can be recreated. The new command
1310 "set use-deprecated-index-sections on" will cause GDB to use any older
1311 .gdb_index sections it finds. This will restore performance, but the
1312 ability to set breakpoints on inlined functions will be lost in symbol
1313 files with older .gdb_index sections.
1315 The .gdb_index section has also been updated to record more information
1316 about each symbol. This speeds up the "info variables", "info functions"
1317 and "info types" commands when used with programs having the .gdb_index
1318 section, as well as speeding up debugging with shared libraries using
1319 the .gdb_index section.
1321 * Ada support for GDB/MI Variable Objects has been added.
1323 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1328 ** New command -info-os is the MI equivalent of "info os".
1330 ** Output logs ("set logging" and related) now include MI output.
1334 ** "set use-deprecated-index-sections on|off"
1335 "show use-deprecated-index-sections on|off"
1336 Controls the use of deprecated .gdb_index sections.
1338 ** "catch load" and "catch unload" can be used to stop when a shared
1339 library is loaded or unloaded, respectively.
1341 ** "enable count" can be used to auto-disable a breakpoint after
1344 ** "info vtbl" can be used to show the virtual method tables for
1345 C++ and Java objects.
1347 ** "explore" and its sub commands "explore value" and "explore type"
1348 can be used to recursively explore values and types of
1349 expressions. These commands are available only if GDB is
1350 configured with '--with-python'.
1352 ** "info auto-load" shows status of all kinds of auto-loaded files,
1353 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1354 sequences of commands files, "info auto-load python-scripts"
1355 shows status of auto-loading Python script files,
1356 "info auto-load local-gdbinit" shows status of loading init file
1357 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1358 status of inferior specific thread debugging shared library loading.
1360 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1361 and "show auto-load-scripts" commands have been deprecated, use their
1362 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1363 and "show auto-load python-scripts" counterparts instead.
1365 ** "dprintf location,format,args..." creates a dynamic printf, which
1366 is basically a breakpoint that does a printf and immediately
1367 resumes your program's execution, so it is like a printf that you
1368 can insert dynamically at runtime instead of at compiletime.
1370 ** "set print symbol"
1372 Controls whether GDB attempts to display the symbol, if any,
1373 corresponding to addresses it prints. This defaults to "on", but
1374 you can set it to "off" to restore GDB's previous behavior.
1376 * Deprecated commands
1378 ** For the Renesas Super-H architecture, the "regs" command has been
1379 deprecated, and "info all-registers" should be used instead.
1383 Renesas RL78 rl78-*-elf
1384 HP OpenVMS ia64 ia64-hp-openvms*
1386 * GDBserver supports evaluation of breakpoint conditions. When
1387 support is advertised by GDBserver, GDB may be told to send the
1388 breakpoint conditions in bytecode form to GDBserver. GDBserver
1389 will only report the breakpoint trigger to GDB when its condition
1394 set mips compression
1395 show mips compression
1396 Select the compressed ISA encoding used in functions that have no symbol
1397 information available. The encoding can be set to either of:
1400 and is updated automatically from ELF file flags if available.
1402 set breakpoint condition-evaluation
1403 show breakpoint condition-evaluation
1404 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1405 GDBserver ("target"). Default option "auto" chooses the most efficient
1407 This option can improve debugger efficiency depending on the speed of the
1411 Disable auto-loading globally.
1414 Show auto-loading setting of all kinds of auto-loaded files.
1416 set auto-load gdb-scripts on|off
1417 show auto-load gdb-scripts
1418 Control auto-loading of GDB canned sequences of commands files.
1420 set auto-load python-scripts on|off
1421 show auto-load python-scripts
1422 Control auto-loading of Python script files.
1424 set auto-load local-gdbinit on|off
1425 show auto-load local-gdbinit
1426 Control loading of init file (.gdbinit) from current directory.
1428 set auto-load libthread-db on|off
1429 show auto-load libthread-db
1430 Control auto-loading of inferior specific thread debugging shared library.
1432 set auto-load scripts-directory <dir1>[:<dir2>...]
1433 show auto-load scripts-directory
1434 Set a list of directories from which to load auto-loaded scripts.
1435 Automatically loaded Python scripts and GDB scripts are located in one
1436 of the directories listed by this option.
1437 The delimiter (':' above) may differ according to the host platform.
1439 set auto-load safe-path <dir1>[:<dir2>...]
1440 show auto-load safe-path
1441 Set a list of directories from which it is safe to auto-load files.
1442 The delimiter (':' above) may differ according to the host platform.
1444 set debug auto-load on|off
1445 show debug auto-load
1446 Control display of debugging info for auto-loading the files above.
1448 set dprintf-style gdb|call|agent
1450 Control the way in which a dynamic printf is performed; "gdb"
1451 requests a GDB printf command, while "call" causes dprintf to call a
1452 function in the inferior. "agent" requests that the target agent
1453 (such as GDBserver) do the printing.
1455 set dprintf-function <expr>
1456 show dprintf-function
1457 set dprintf-channel <expr>
1458 show dprintf-channel
1459 Set the function and optional first argument to the call when using
1460 the "call" style of dynamic printf.
1462 set disconnected-dprintf on|off
1463 show disconnected-dprintf
1464 Control whether agent-style dynamic printfs continue to be in effect
1465 after GDB disconnects.
1467 * New configure options
1469 --with-auto-load-dir
1470 Configure default value for the 'set auto-load scripts-directory'
1471 setting above. It defaults to '$debugdir:$datadir/auto-load',
1472 $debugdir representing global debugging info directories (available
1473 via 'show debug-file-directory') and $datadir representing GDB's data
1474 directory (available via 'show data-directory').
1476 --with-auto-load-safe-path
1477 Configure default value for the 'set auto-load safe-path' setting
1478 above. It defaults to the --with-auto-load-dir setting.
1480 --without-auto-load-safe-path
1481 Set 'set auto-load safe-path' to '/', effectively disabling this
1484 * New remote packets
1486 z0/z1 conditional breakpoints extension
1488 The z0/z1 breakpoint insertion packets have been extended to carry
1489 a list of conditional expressions over to the remote stub depending on the
1490 condition evaluation mode. The use of this extension can be controlled
1491 via the "set remote conditional-breakpoints-packet" command.
1495 Specify the signals which the remote stub may pass to the debugged
1496 program without GDB involvement.
1498 * New command line options
1500 --init-command=FILE, -ix Like --command, -x but execute it
1501 before loading inferior.
1502 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1503 execute it before loading inferior.
1505 *** Changes in GDB 7.4
1507 * GDB now handles ambiguous linespecs more consistently; the existing
1508 FILE:LINE support has been expanded to other types of linespecs. A
1509 breakpoint will now be set on all matching locations in all
1510 inferiors, and locations will be added or removed according to
1513 * GDB now allows you to skip uninteresting functions and files when
1514 stepping with the "skip function" and "skip file" commands.
1516 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1517 and "show remote hardware-watchpoint-length-limit". These allows to
1518 set or show the maximum length limit (in bytes) of a remote
1519 target hardware watchpoint.
1521 This allows e.g. to use "unlimited" hardware watchpoints with the
1522 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1523 watchpoints are slower than real hardware watchpoints but are
1524 significantly faster than gdb software watchpoints.
1528 ** The register_pretty_printer function in module gdb.printing now takes
1529 an optional `replace' argument. If True, the new printer replaces any
1532 ** The "maint set python print-stack on|off" command has been
1533 deprecated and will be deleted in GDB 7.5.
1534 A new command: "set python print-stack none|full|message" has
1535 replaced it. Additionally, the default for "print-stack" is
1536 now "message", which just prints the error message without
1539 ** A prompt substitution hook (prompt_hook) is now available to the
1542 ** A new Python module, gdb.prompt has been added to the GDB Python
1543 modules library. This module provides functionality for
1544 escape sequences in prompts (used by set/show
1545 extended-prompt). These escape sequences are replaced by their
1546 corresponding value.
1548 ** Python commands and convenience-functions located in
1549 'data-directory'/python/gdb/command and
1550 'data-directory'/python/gdb/function are now automatically loaded
1553 ** Blocks now provide four new attributes. global_block and
1554 static_block will return the global and static blocks
1555 respectively. is_static and is_global are boolean attributes
1556 that indicate if the block is one of those two types.
1558 ** Symbols now provide the "type" attribute, the type of the symbol.
1560 ** The "gdb.breakpoint" function has been deprecated in favor of
1563 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1564 of a function. This class is based on the "finish" command
1565 available in the CLI.
1567 ** Type objects for struct and union types now allow access to
1568 the fields using standard Python dictionary (mapping) methods.
1569 For example, "some_type['myfield']" now works, as does
1570 "some_type.items()".
1572 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1575 ** A new function, "deep_items" has been added to the gdb.types
1576 module in the GDB Python modules library. This function returns
1577 an iterator over the fields of a struct or union type. Unlike
1578 the standard Python "iteritems" method, it will recursively traverse
1579 any anonymous fields.
1583 ** "*stopped" events can report several new "reason"s, such as
1586 ** Breakpoint changes are now notified using new async records, like
1587 "=breakpoint-modified".
1589 ** New command -ada-task-info.
1591 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1592 $sdir specifies the default system locations of shared libraries.
1593 $pdir specifies the directory where the libpthread used by the application
1596 GDB no longer looks in $sdir and $pdir after it has searched the directories
1597 mentioned in libthread-db-search-path. If you want to search those
1598 directories, they must be specified in libthread-db-search-path.
1599 The default value of libthread-db-search-path on GNU/Linux and Solaris
1600 systems is now "$sdir:$pdir".
1602 $pdir is not supported by gdbserver, it is currently ignored.
1603 $sdir is supported by gdbserver.
1605 * New configure option --with-iconv-bin.
1606 When using the internationalization support like the one in the GNU C
1607 library, GDB will invoke the "iconv" program to get a list of supported
1608 character sets. If this program lives in a non-standard location, one can
1609 use this option to specify where to find it.
1611 * When natively debugging programs on PowerPC BookE processors running
1612 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1613 watchpoints, which specify a mask in addition to an address to watch.
1614 The mask specifies that some bits of an address (the bits which are
1615 reset in the mask) should be ignored when matching the address accessed
1616 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1617 section in the user manual for more details.
1619 * The new option --once causes GDBserver to stop listening for connections once
1620 the first connection is made. The listening port used by GDBserver will
1621 become available after that.
1623 * New commands "info macros" and "alias" have been added.
1625 * New function parameters suffix @entry specifies value of function parameter
1626 at the time the function got called. Entry values are available only since
1632 "!" is now an alias of the "shell" command.
1633 Note that no space is needed between "!" and SHELL COMMAND.
1637 watch EXPRESSION mask MASK_VALUE
1638 The watch command now supports the mask argument which allows creation
1639 of masked watchpoints, if the current architecture supports this feature.
1641 info auto-load-scripts [REGEXP]
1642 This command was formerly named "maintenance print section-scripts".
1643 It is now generally useful and is no longer a maintenance-only command.
1645 info macro [-all] [--] MACRO
1646 The info macro command has new options `-all' and `--'. The first for
1647 printing all definitions of a macro. The second for explicitly specifying
1648 the end of arguments and the beginning of the macro name in case the macro
1649 name starts with a hyphen.
1651 collect[/s] EXPRESSIONS
1652 The tracepoint collect command now takes an optional modifier "/s"
1653 that directs it to dereference pointer-to-character types and
1654 collect the bytes of memory up to a zero byte. The behavior is
1655 similar to what you see when you use the regular print command on a
1656 string. An optional integer following the "/s" sets a bound on the
1657 number of bytes that will be collected.
1660 The trace start command now interprets any supplied arguments as a
1661 note to be recorded with the trace run, with an effect similar to
1662 setting the variable trace-notes.
1665 The trace stop command now interprets any arguments as a note to be
1666 mentioned along with the tstatus report that the trace was stopped
1667 with a command. The effect is similar to setting the variable
1670 * Tracepoints can now be enabled and disabled at any time after a trace
1671 experiment has been started using the standard "enable" and "disable"
1672 commands. It is now possible to start a trace experiment with no enabled
1673 tracepoints; GDB will display a warning, but will allow the experiment to
1674 begin, assuming that tracepoints will be enabled as needed while the trace
1677 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1678 locations with 4-byte instructions, when they were previously
1679 limited to locations with instructions of 5 bytes or longer.
1683 set debug dwarf2-read
1684 show debug dwarf2-read
1685 Turns on or off display of debugging messages related to reading
1686 DWARF debug info. The default is off.
1688 set debug symtab-create
1689 show debug symtab-create
1690 Turns on or off display of debugging messages related to symbol table
1691 creation. The default is off.
1694 show extended-prompt
1695 Set the GDB prompt, and allow escape sequences to be inserted to
1696 display miscellaneous information (see 'help set extended-prompt'
1697 for the list of sequences). This prompt (and any information
1698 accessed through the escape sequences) is updated every time the
1699 prompt is displayed.
1701 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1702 show print entry-values
1703 Set printing of frame argument values at function entry. In some cases
1704 GDB can determine the value of function argument which was passed by the
1705 function caller, even if the value was modified inside the called function.
1707 set debug entry-values
1708 show debug entry-values
1709 Control display of debugging info for determining frame argument values at
1710 function entry and virtual tail call frames.
1712 set basenames-may-differ
1713 show basenames-may-differ
1714 Set whether a source file may have multiple base names.
1715 (A "base name" is the name of a file with the directory part removed.
1716 Example: The base name of "/home/user/hello.c" is "hello.c".)
1717 If set, GDB will canonicalize file names (e.g., expand symlinks)
1718 before comparing them. Canonicalization is an expensive operation,
1719 but it allows the same file be known by more than one base name.
1720 If not set (the default), all source files are assumed to have just
1721 one base name, and gdb will do file name comparisons more efficiently.
1727 Set a user name and notes for the current and any future trace runs.
1728 This is useful for long-running and/or disconnected traces, to
1729 inform others (or yourself) as to who is running the trace, supply
1730 contact information, or otherwise explain what is going on.
1732 set trace-stop-notes
1733 show trace-stop-notes
1734 Set a note attached to the trace run, that is displayed when the
1735 trace has been stopped by a tstop command. This is useful for
1736 instance as an explanation, if you are stopping a trace run that was
1737 started by someone else.
1739 * New remote packets
1743 Dynamically enable a tracepoint in a started trace experiment.
1747 Dynamically disable a tracepoint in a started trace experiment.
1751 Set the user and notes of the trace run.
1755 Query the current status of a tracepoint.
1759 Query the minimum length of instruction at which a fast tracepoint may
1762 * Dcache size (number of lines) and line-size are now runtime-configurable
1763 via "set dcache line" and "set dcache line-size" commands.
1767 Texas Instruments TMS320C6x tic6x-*-*
1771 Renesas RL78 rl78-*-elf
1773 *** Changes in GDB 7.3.1
1775 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1777 *** Changes in GDB 7.3
1779 * GDB has a new command: "thread find [REGEXP]".
1780 It finds the thread id whose name, target id, or thread extra info
1781 matches the given regular expression.
1783 * The "catch syscall" command now works on mips*-linux* targets.
1785 * The -data-disassemble MI command now supports modes 2 and 3 for
1786 dumping the instruction opcodes.
1788 * New command line options
1790 -data-directory DIR Specify DIR as the "data-directory".
1791 This is mostly for testing purposes.
1793 * The "maint set python auto-load on|off" command has been renamed to
1794 "set auto-load-scripts on|off".
1796 * GDB has a new command: "set directories".
1797 It is like the "dir" command except that it replaces the
1798 source path list instead of augmenting it.
1800 * GDB now understands thread names.
1802 On GNU/Linux, "info threads" will display the thread name as set by
1803 prctl or pthread_setname_np.
1805 There is also a new command, "thread name", which can be used to
1806 assign a name internally for GDB to display.
1809 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1810 has been integrated into GDB.
1814 ** The function gdb.Write now accepts an optional keyword 'stream'.
1815 This keyword, when provided, will direct the output to either
1816 stdout, stderr, or GDB's logging output.
1818 ** Parameters can now be be sub-classed in Python, and in particular
1819 you may implement the get_set_doc and get_show_doc functions.
1820 This improves how Parameter set/show documentation is processed
1821 and allows for more dynamic content.
1823 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1824 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1825 have an is_valid method.
1827 ** Breakpoints can now be sub-classed in Python, and in particular
1828 you may implement a 'stop' function that is executed each time
1829 the inferior reaches that breakpoint.
1831 ** New function gdb.lookup_global_symbol looks up a global symbol.
1833 ** GDB values in Python are now callable if the value represents a
1834 function. For example, if 'some_value' represents a function that
1835 takes two integer parameters and returns a value, you can call
1836 that function like so:
1838 result = some_value (10,20)
1840 ** Module gdb.types has been added.
1841 It contains a collection of utilities for working with gdb.Types objects:
1842 get_basic_type, has_field, make_enum_dict.
1844 ** Module gdb.printing has been added.
1845 It contains utilities for writing and registering pretty-printers.
1846 New classes: PrettyPrinter, SubPrettyPrinter,
1847 RegexpCollectionPrettyPrinter.
1848 New function: register_pretty_printer.
1850 ** New commands "info pretty-printers", "enable pretty-printer" and
1851 "disable pretty-printer" have been added.
1853 ** gdb.parameter("directories") is now available.
1855 ** New function gdb.newest_frame returns the newest frame in the
1858 ** The gdb.InferiorThread class has a new "name" attribute. This
1859 holds the thread's name.
1861 ** Python Support for Inferior events.
1862 Python scripts can add observers to be notified of events
1863 occurring in the process being debugged.
1864 The following events are currently supported:
1865 - gdb.events.cont Continue event.
1866 - gdb.events.exited Inferior exited event.
1867 - gdb.events.stop Signal received, and Breakpoint hit events.
1871 ** GDB now puts template parameters in scope when debugging in an
1872 instantiation. For example, if you have:
1874 template<int X> int func (void) { return X; }
1876 then if you step into func<5>, "print X" will show "5". This
1877 feature requires proper debuginfo support from the compiler; it
1878 was added to GCC 4.5.
1880 ** The motion commands "next", "finish", "until", and "advance" now
1881 work better when exceptions are thrown. In particular, GDB will
1882 no longer lose control of the inferior; instead, the GDB will
1883 stop the inferior at the point at which the exception is caught.
1884 This functionality requires a change in the exception handling
1885 code that was introduced in GCC 4.5.
1887 * GDB now follows GCC's rules on accessing volatile objects when
1888 reading or writing target state during expression evaluation.
1889 One notable difference to prior behavior is that "print x = 0"
1890 no longer generates a read of x; the value of the assignment is
1891 now always taken directly from the value being assigned.
1893 * GDB now has some support for using labels in the program's source in
1894 linespecs. For instance, you can use "advance label" to continue
1895 execution to a label.
1897 * GDB now has support for reading and writing a new .gdb_index
1898 section. This section holds a fast index of DWARF debugging
1899 information and can be used to greatly speed up GDB startup and
1900 operation. See the documentation for `save gdb-index' for details.
1902 * The "watch" command now accepts an optional "-location" argument.
1903 When used, this causes GDB to watch the memory referred to by the
1904 expression. Such a watchpoint is never deleted due to it going out
1907 * GDB now supports thread debugging of core dumps on GNU/Linux.
1909 GDB now activates thread debugging using the libthread_db library
1910 when debugging GNU/Linux core dumps, similarly to when debugging
1911 live processes. As a result, when debugging a core dump file, GDB
1912 is now able to display pthread_t ids of threads. For example, "info
1913 threads" shows the same output as when debugging the process when it
1914 was live. In earlier releases, you'd see something like this:
1917 * 1 LWP 6780 main () at main.c:10
1919 While now you see this:
1922 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1924 It is also now possible to inspect TLS variables when debugging core
1927 When debugging a core dump generated on a machine other than the one
1928 used to run GDB, you may need to point GDB at the correct
1929 libthread_db library with the "set libthread-db-search-path"
1930 command. See the user manual for more details on this command.
1932 * When natively debugging programs on PowerPC BookE processors running
1933 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1934 which stop execution of the inferior whenever it executes an instruction
1935 at any address within the specified range. See the "PowerPC Embedded"
1936 section in the user manual for more details.
1938 * New features in the GDB remote stub, GDBserver
1940 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1941 and i686 LynxOS (version 5.x).
1943 ** GDBserver is now supported on Blackfin Linux.
1945 * New native configurations
1947 ia64 HP-UX ia64-*-hpux*
1951 Analog Devices, Inc. Blackfin Processor bfin-*
1953 * Ada task switching is now supported on sparc-elf targets when
1954 debugging a program using the Ravenscar Profile. For more information,
1955 see the "Tasking Support when using the Ravenscar Profile" section
1956 in the GDB user manual.
1958 * Guile support was removed.
1960 * New features in the GNU simulator
1962 ** The --map-info flag lists all known core mappings.
1964 ** CFI flashes may be simulated via the "cfi" device.
1966 *** Changes in GDB 7.2
1968 * Shared library support for remote targets by default
1970 When GDB is configured for a generic, non-OS specific target, like
1971 for example, --target=arm-eabi or one of the many *-*-elf targets,
1972 GDB now queries remote stubs for loaded shared libraries using the
1973 `qXfer:libraries:read' packet. Previously, shared library support
1974 was always disabled for such configurations.
1978 ** Argument Dependent Lookup (ADL)
1980 In C++ ADL lookup directs function search to the namespaces of its
1981 arguments even if the namespace has not been imported.
1991 Here the compiler will search for `foo' in the namespace of 'b'
1992 and find A::foo. GDB now supports this. This construct is commonly
1993 used in the Standard Template Library for operators.
1995 ** Improved User Defined Operator Support
1997 In addition to member operators, GDB now supports lookup of operators
1998 defined in a namespace and imported with a `using' directive, operators
1999 defined in the global scope, operators imported implicitly from an
2000 anonymous namespace, and the ADL operators mentioned in the previous
2002 GDB now also supports proper overload resolution for all the previously
2003 mentioned flavors of operators.
2005 ** static const class members
2007 Printing of static const class members that are initialized in the
2008 class definition has been fixed.
2010 * Windows Thread Information Block access.
2012 On Windows targets, GDB now supports displaying the Windows Thread
2013 Information Block (TIB) structure. This structure is visible either
2014 by using the new command `info w32 thread-information-block' or, by
2015 dereferencing the new convenience variable named `$_tlb', a
2016 thread-specific pointer to the TIB. This feature is also supported
2017 when remote debugging using GDBserver.
2019 * Static tracepoints
2021 Static tracepoints are calls in the user program into a tracing
2022 library. One such library is a port of the LTTng kernel tracer to
2023 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2024 When debugging with GDBserver, GDB now supports combining the GDB
2025 tracepoint machinery with such libraries. For example: the user can
2026 use GDB to probe a static tracepoint marker (a call from the user
2027 program into the tracing library) with the new "strace" command (see
2028 "New commands" below). This creates a "static tracepoint" in the
2029 breakpoint list, that can be manipulated with the same feature set
2030 as fast and regular tracepoints. E.g., collect registers, local and
2031 global variables, collect trace state variables, and define
2032 tracepoint conditions. In addition, the user can collect extra
2033 static tracepoint marker specific data, by collecting the new
2034 $_sdata internal variable. When analyzing the trace buffer, you can
2035 inspect $_sdata like any other variable available to GDB. For more
2036 information, see the "Tracepoints" chapter in GDB user manual. New
2037 remote packets have been defined to support static tracepoints, see
2038 the "New remote packets" section below.
2040 * Better reconstruction of tracepoints after disconnected tracing
2042 GDB will attempt to download the original source form of tracepoint
2043 definitions when starting a trace run, and then will upload these
2044 upon reconnection to the target, resulting in a more accurate
2045 reconstruction of the tracepoints that are in use on the target.
2049 You can now exercise direct control over the ways that GDB can
2050 affect your program. For instance, you can disallow the setting of
2051 breakpoints, so that the program can run continuously (assuming
2052 non-stop mode). In addition, the "observer" variable is available
2053 to switch all of the different controls; in observer mode, GDB
2054 cannot affect the target's behavior at all, which is useful for
2055 tasks like diagnosing live systems in the field.
2057 * The new convenience variable $_thread holds the number of the
2060 * New remote packets
2064 Return the address of the Windows Thread Information Block of a given thread.
2068 In response to several of the tracepoint packets, the target may now
2069 also respond with a number of intermediate `qRelocInsn' request
2070 packets before the final result packet, to have GDB handle
2071 relocating an instruction to execute at a different address. This
2072 is particularly useful for stubs that support fast tracepoints. GDB
2073 reports support for this feature in the qSupported packet.
2077 List static tracepoint markers in the target program.
2081 List static tracepoint markers at a given address in the target
2084 qXfer:statictrace:read
2086 Read the static trace data collected (by a `collect $_sdata'
2087 tracepoint action). The remote stub reports support for this packet
2088 to gdb's qSupported query.
2092 Send the current settings of GDB's permission flags.
2096 Send part of the source (textual) form of a tracepoint definition,
2097 which includes location, conditional, and action list.
2099 * The source command now accepts a -s option to force searching for the
2100 script in the source search path even if the script name specifies
2103 * New features in the GDB remote stub, GDBserver
2105 - GDBserver now support tracepoints (including fast tracepoints, and
2106 static tracepoints). The feature is currently supported by the
2107 i386-linux and amd64-linux builds. See the "Tracepoints support
2108 in gdbserver" section in the manual for more information.
2110 GDBserver JIT compiles the tracepoint's conditional agent
2111 expression bytecode into native code whenever possible for low
2112 overhead dynamic tracepoints conditionals. For such tracepoints,
2113 an expression that examines program state is evaluated when the
2114 tracepoint is reached, in order to determine whether to capture
2115 trace data. If the condition is simple and false, processing the
2116 tracepoint finishes very quickly and no data is gathered.
2118 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2119 for static tracepoints support.
2121 - GDBserver now supports x86_64 Windows 64-bit debugging.
2123 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2124 it understands register description.
2126 * The --batch flag now disables pagination and queries.
2128 * X86 general purpose registers
2130 GDB now supports reading/writing byte, word and double-word x86
2131 general purpose registers directly. This means you can use, say,
2132 $ah or $ax to refer, respectively, to the byte register AH and
2133 16-bit word register AX that are actually portions of the 32-bit
2134 register EAX or 64-bit register RAX.
2136 * The `commands' command now accepts a range of breakpoints to modify.
2137 A plain `commands' following a command that creates multiple
2138 breakpoints affects all the breakpoints set by that command. This
2139 applies to breakpoints set by `rbreak', and also applies when a
2140 single `break' command creates multiple breakpoints (e.g.,
2141 breakpoints on overloaded c++ functions).
2143 * The `rbreak' command now accepts a filename specification as part of
2144 its argument, limiting the functions selected by the regex to those
2145 in the specified file.
2147 * Support for remote debugging Windows and SymbianOS shared libraries
2148 from Unix hosts has been improved. Non Windows GDB builds now can
2149 understand target reported file names that follow MS-DOS based file
2150 system semantics, such as file names that include drive letters and
2151 use the backslash character as directory separator. This makes it
2152 possible to transparently use the "set sysroot" and "set
2153 solib-search-path" on Unix hosts to point as host copies of the
2154 target's shared libraries. See the new command "set
2155 target-file-system-kind" described below, and the "Commands to
2156 specify files" section in the user manual for more information.
2160 eval template, expressions...
2161 Convert the values of one or more expressions under the control
2162 of the string template to a command line, and call it.
2164 set target-file-system-kind unix|dos-based|auto
2165 show target-file-system-kind
2166 Set or show the assumed file system kind for target reported file
2169 save breakpoints <filename>
2170 Save all current breakpoint definitions to a file suitable for use
2171 in a later debugging session. To read the saved breakpoint
2172 definitions, use the `source' command.
2174 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2177 info static-tracepoint-markers
2178 Display information about static tracepoint markers in the target.
2180 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2181 Define a static tracepoint by probing a marker at the given
2182 function, line, address, or marker ID.
2186 Enable and disable observer mode.
2188 set may-write-registers on|off
2189 set may-write-memory on|off
2190 set may-insert-breakpoints on|off
2191 set may-insert-tracepoints on|off
2192 set may-insert-fast-tracepoints on|off
2193 set may-interrupt on|off
2194 Set individual permissions for GDB effects on the target. Note that
2195 some of these settings can have undesirable or surprising
2196 consequences, particularly when changed in the middle of a session.
2197 For instance, disabling the writing of memory can prevent
2198 breakpoints from being inserted, cause single-stepping to fail, or
2199 even crash your program, if you disable after breakpoints have been
2200 inserted. However, GDB should not crash.
2202 set record memory-query on|off
2203 show record memory-query
2204 Control whether to stop the inferior if memory changes caused
2205 by an instruction cannot be recorded.
2210 The disassemble command now supports "start,+length" form of two arguments.
2214 ** GDB now provides a new directory location, called the python directory,
2215 where Python scripts written for GDB can be installed. The location
2216 of that directory is <data-directory>/python, where <data-directory>
2217 is the GDB data directory. For more details, see section `Scripting
2218 GDB using Python' in the manual.
2220 ** The GDB Python API now has access to breakpoints, symbols, symbol
2221 tables, program spaces, inferiors, threads and frame's code blocks.
2222 Additionally, GDB Parameters can now be created from the API, and
2223 manipulated via set/show in the CLI.
2225 ** New functions gdb.target_charset, gdb.target_wide_charset,
2226 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2228 ** New exception gdb.GdbError.
2230 ** Pretty-printers are now also looked up in the current program space.
2232 ** Pretty-printers can now be individually enabled and disabled.
2234 ** GDB now looks for names of Python scripts to auto-load in a
2235 special section named `.debug_gdb_scripts', in addition to looking
2236 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2238 * Tracepoint actions were unified with breakpoint commands. In particular,
2239 there are no longer differences in "info break" output for breakpoints and
2240 tracepoints and the "commands" command can be used for both tracepoints and
2241 regular breakpoints.
2245 ARM Symbian arm*-*-symbianelf*
2247 * D language support.
2248 GDB now supports debugging programs written in the D programming
2251 * GDB now supports the extended ptrace interface for PowerPC which is
2252 available since Linux kernel version 2.6.34. This automatically enables
2253 any hardware breakpoints and additional hardware watchpoints available in
2254 the processor. The old ptrace interface exposes just one hardware
2255 watchpoint and no hardware breakpoints.
2257 * GDB is now able to use the Data Value Compare (DVC) register available on
2258 embedded PowerPC processors to implement in hardware simple watchpoint
2259 conditions of the form:
2261 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2263 This works in native GDB running on Linux kernels with the extended ptrace
2264 interface mentioned above.
2266 *** Changes in GDB 7.1
2270 ** Namespace Support
2272 GDB now supports importing of namespaces in C++. This enables the
2273 user to inspect variables from imported namespaces. Support for
2274 namepace aliasing has also been added. So, if a namespace is
2275 aliased in the current scope (e.g. namepace C=A; ) the user can
2276 print variables using the alias (e.g. (gdb) print C::x).
2280 All known bugs relating to the printing of virtual base class were
2281 fixed. It is now possible to call overloaded static methods using a
2286 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2287 and reinterpret_cast<> are now handled by the C++ expression parser.
2291 Xilinx MicroBlaze microblaze-*-*
2296 Xilinx MicroBlaze microblaze
2299 * Multi-program debugging.
2301 GDB now has support for multi-program (a.k.a. multi-executable or
2302 multi-exec) debugging. This allows for debugging multiple inferiors
2303 simultaneously each running a different program under the same GDB
2304 session. See "Debugging Multiple Inferiors and Programs" in the
2305 manual for more information. This implied some user visible changes
2306 in the multi-inferior support. For example, "info inferiors" now
2307 lists inferiors that are not running yet or that have exited
2308 already. See also "New commands" and "New options" below.
2310 * New tracing features
2312 GDB's tracepoint facility now includes several new features:
2314 ** Trace state variables
2316 GDB tracepoints now include support for trace state variables, which
2317 are variables managed by the target agent during a tracing
2318 experiment. They are useful for tracepoints that trigger each
2319 other, so for instance one tracepoint can count hits in a variable,
2320 and then a second tracepoint has a condition that is true when the
2321 count reaches a particular value. Trace state variables share the
2322 $-syntax of GDB convenience variables, and can appear in both
2323 tracepoint actions and condition expressions. Use the "tvariable"
2324 command to create, and "info tvariables" to view; see "Trace State
2325 Variables" in the manual for more detail.
2329 GDB now includes an option for defining fast tracepoints, which
2330 targets may implement more efficiently, such as by installing a jump
2331 into the target agent rather than a trap instruction. The resulting
2332 speedup can be by two orders of magnitude or more, although the
2333 tradeoff is that some program locations on some target architectures
2334 might not allow fast tracepoint installation, for instance if the
2335 instruction to be replaced is shorter than the jump. To request a
2336 fast tracepoint, use the "ftrace" command, with syntax identical to
2337 the regular trace command.
2339 ** Disconnected tracing
2341 It is now possible to detach GDB from the target while it is running
2342 a trace experiment, then reconnect later to see how the experiment
2343 is going. In addition, a new variable disconnected-tracing lets you
2344 tell the target agent whether to continue running a trace if the
2345 connection is lost unexpectedly.
2349 GDB now has the ability to save the trace buffer into a file, and
2350 then use that file as a target, similarly to you can do with
2351 corefiles. You can select trace frames, print data that was
2352 collected in them, and use tstatus to display the state of the
2353 tracing run at the moment that it was saved. To create a trace
2354 file, use "tsave <filename>", and to use it, do "target tfile
2357 ** Circular trace buffer
2359 You can ask the target agent to handle the trace buffer as a
2360 circular buffer, discarding the oldest trace frames to make room for
2361 newer ones, by setting circular-trace-buffer to on. This feature may
2362 not be available for all target agents.
2367 The disassemble command, when invoked with two arguments, now requires
2368 the arguments to be comma-separated.
2371 The info variables command now displays variable definitions. Files
2372 which only declare a variable are not shown.
2375 The source command is now capable of sourcing Python scripts.
2376 This feature is dependent on the debugger being build with Python
2379 Related to this enhancement is also the introduction of a new command
2380 "set script-extension" (see below).
2382 * New commands (for set/show, see "New options" below)
2384 record save [<FILENAME>]
2385 Save a file (in core file format) containing the process record
2386 execution log for replay debugging at a later time.
2388 record restore <FILENAME>
2389 Restore the process record execution log that was saved at an
2390 earlier time, for replay debugging.
2392 add-inferior [-copies <N>] [-exec <FILENAME>]
2395 clone-inferior [-copies <N>] [ID]
2396 Make a new inferior ready to execute the same program another
2397 inferior has loaded.
2402 maint info program-spaces
2403 List the program spaces loaded into GDB.
2405 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2406 show remote interrupt-sequence
2407 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2408 as the sequence to the remote target in order to interrupt the execution.
2409 Ctrl-C is a default. Some system prefers BREAK which is high level of
2410 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2411 Magic SysRq g. It is BREAK signal and character 'g'.
2413 set remote interrupt-on-connect [on | off]
2414 show remote interrupt-on-connect
2415 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2416 remote target when gdb connects to it. This is needed when you debug
2419 set remotebreak [on | off]
2421 Deprecated. Use "set/show remote interrupt-sequence" instead.
2423 tvariable $NAME [ = EXP ]
2424 Create or modify a trace state variable.
2427 List trace state variables and their values.
2429 delete tvariable $NAME ...
2430 Delete one or more trace state variables.
2433 Evaluate the given expressions without collecting anything into the
2434 trace buffer. (Valid in tracepoint actions only.)
2436 ftrace FN / FILE:LINE / *ADDR
2437 Define a fast tracepoint at the given function, line, or address.
2439 * New expression syntax
2441 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2442 GDB now parses 0b101010 identically with 42.
2446 set follow-exec-mode new|same
2447 show follow-exec-mode
2448 Control whether GDB reuses the same inferior across an exec call or
2449 creates a new one. This is useful to be able to restart the old
2450 executable after the inferior having done an exec call.
2452 set default-collect EXPR, ...
2453 show default-collect
2454 Define a list of expressions to be collected at each tracepoint.
2455 This is a useful way to ensure essential items are not overlooked,
2456 such as registers or a critical global variable.
2458 set disconnected-tracing
2459 show disconnected-tracing
2460 If set to 1, the target is instructed to continue tracing if it
2461 loses its connection to GDB. If 0, the target is to stop tracing
2464 set circular-trace-buffer
2465 show circular-trace-buffer
2466 If set to on, the target is instructed to use a circular trace buffer
2467 and discard the oldest trace frames instead of stopping the trace due
2468 to a full trace buffer. If set to off, the trace stops when the buffer
2469 fills up. Some targets may not support this.
2471 set script-extension off|soft|strict
2472 show script-extension
2473 If set to "off", the debugger does not perform any script language
2474 recognition, and all sourced files are assumed to be GDB scripts.
2475 If set to "soft" (the default), files are sourced according to
2476 filename extension, falling back to GDB scripts if the first
2478 If set to "strict", files are sourced according to filename extension.
2480 set ada trust-PAD-over-XVS on|off
2481 show ada trust-PAD-over-XVS
2482 If off, activate a workaround against a bug in the debugging information
2483 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2484 the GCC sources for more information about the GNAT encoding and
2485 PAD types in particular). It is always safe to set this option to
2486 off, but this introduces a slight performance penalty. The default
2489 * Python API Improvements
2491 ** GDB provides the new class gdb.LazyString. This is useful in
2492 some pretty-printing cases. The new method gdb.Value.lazy_string
2493 provides a simple way to create objects of this type.
2495 ** The fields returned by gdb.Type.fields now have an
2496 `is_base_class' attribute.
2498 ** The new method gdb.Type.range returns the range of an array type.
2500 ** The new method gdb.parse_and_eval can be used to parse and
2501 evaluate an expression.
2503 * New remote packets
2506 Define a trace state variable.
2509 Get the current value of a trace state variable.
2512 Set desired tracing behavior upon disconnection.
2515 Set the trace buffer to be linear or circular.
2518 Get data about the tracepoints currently in use.
2522 Process record now works correctly with hardware watchpoints.
2524 Multiple bug fixes have been made to the mips-irix port, making it
2525 much more reliable. In particular:
2526 - Debugging threaded applications is now possible again. Previously,
2527 GDB would hang while starting the program, or while waiting for
2528 the program to stop at a breakpoint.
2529 - Attaching to a running process no longer hangs.
2530 - An error occurring while loading a core file has been fixed.
2531 - Changing the value of the PC register now works again. This fixes
2532 problems observed when using the "jump" command, or when calling
2533 a function from GDB, or even when assigning a new value to $pc.
2534 - With the "finish" and "return" commands, the return value for functions
2535 returning a small array is now correctly printed.
2536 - It is now possible to break on shared library code which gets executed
2537 during a shared library init phase (code executed while executing
2538 their .init section). Previously, the breakpoint would have no effect.
2539 - GDB is now able to backtrace through the signal handler for
2540 non-threaded programs.
2542 PIE (Position Independent Executable) programs debugging is now supported.
2543 This includes debugging execution of PIC (Position Independent Code) shared
2544 libraries although for that, it should be possible to run such libraries as an
2547 *** Changes in GDB 7.0
2549 * GDB now has an interface for JIT compilation. Applications that
2550 dynamically generate code can create symbol files in memory and register
2551 them with GDB. For users, the feature should work transparently, and
2552 for JIT developers, the interface is documented in the GDB manual in the
2553 "JIT Compilation Interface" chapter.
2555 * Tracepoints may now be conditional. The syntax is as for
2556 breakpoints; either an "if" clause appended to the "trace" command,
2557 or the "condition" command is available. GDB sends the condition to
2558 the target for evaluation using the same bytecode format as is used
2559 for tracepoint actions.
2561 * The disassemble command now supports: an optional /r modifier, print the
2562 raw instructions in hex as well as in symbolic form, and an optional /m
2563 modifier to print mixed source+assembly.
2565 * Process record and replay
2567 In a architecture environment that supports ``process record and
2568 replay'', ``process record and replay'' target can record a log of
2569 the process execution, and replay it with both forward and reverse
2572 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2573 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2574 set execution-direction {forward|reverse}, for targets that support
2577 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2578 feature is available with a native GDB running on kernel version
2581 * GDB now has support for multi-byte and wide character sets on the
2582 target. Strings whose character type is wchar_t, char16_t, or
2583 char32_t are now correctly printed. GDB supports wide- and unicode-
2584 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2585 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2586 `printf'. This feature requires iconv to work properly; if your
2587 system does not have a working iconv, GDB can use GNU libiconv. See
2588 the installation instructions for more information.
2590 * GDB now supports automatic retrieval of shared library files from
2591 remote targets. To use this feature, specify a system root that begins
2592 with the `remote:' prefix, either via the `set sysroot' command or via
2593 the `--with-sysroot' configure-time option.
2595 * "info sharedlibrary" now takes an optional regex of libraries to show,
2596 and it now reports if a shared library has no debugging information.
2598 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2599 now complete on file names.
2601 * When completing in expressions, gdb will attempt to limit
2602 completions to allowable structure or union fields, where appropriate.
2603 For instance, consider:
2605 # struct example { int f1; double f2; };
2606 # struct example variable;
2609 If the user types TAB at the end of this command line, the available
2610 completions will be "f1" and "f2".
2612 * Inlined functions are now supported. They show up in backtraces, and
2613 the "step", "next", and "finish" commands handle them automatically.
2615 * GDB now supports the token-splicing (##) and stringification (#)
2616 operators when expanding macros. It also supports variable-arity
2619 * GDB now supports inspecting extra signal information, exported by
2620 the new $_siginfo convenience variable. The feature is currently
2621 implemented on linux ARM, i386 and amd64.
2623 * GDB can now display the VFP floating point registers and NEON vector
2624 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2625 can provide these registers (requires Linux 2.6.30 or later). Remote
2626 and simulator targets may also provide them.
2628 * New remote packets
2631 Search memory for a sequence of bytes.
2634 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2635 operation over reliable transport links. Use of this packet is
2636 controlled by the `set remote noack-packet' command.
2639 Kill the process with the specified process ID. Use this in preference
2640 to `k' when multiprocess protocol extensions are supported.
2643 Obtains additional operating system information
2647 Read or write additional signal information.
2649 * Removed remote protocol undocumented extension
2651 An undocumented extension to the remote protocol's `S' stop reply
2652 packet that permited the stub to pass a process id was removed.
2653 Remote servers should use the `T' stop reply packet instead.
2655 * GDB now supports multiple function calling conventions according to the
2656 DWARF-2 DW_AT_calling_convention function attribute.
2658 * The SH target utilizes the aforementioned change to distinguish between gcc
2659 and Renesas calling convention. It also adds the new CLI commands
2660 `set/show sh calling-convention'.
2662 * GDB can now read compressed debug sections, as produced by GNU gold
2663 with the --compress-debug-sections=zlib flag.
2665 * 64-bit core files are now supported on AIX.
2667 * Thread switching is now supported on Tru64.
2669 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2670 which will be allocated using malloc later in program execution.
2672 * The qXfer:libraries:read remote procotol packet now allows passing a
2673 list of section offsets.
2675 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2676 conditions handling signals delivered during attach or thread creation
2677 have also been fixed.
2679 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2680 From the user's standpoint, all unqualified instances of True and False
2681 are treated as the standard definitions, regardless of context.
2683 * GDB now parses C++ symbol and type names more flexibly. For
2686 template<typename T> class C { };
2689 GDB will now correctly handle all of:
2691 ptype C<char const *>
2692 ptype C<char const*>
2693 ptype C<const char *>
2694 ptype C<const char*>
2696 * New features in the GDB remote stub, gdbserver
2698 - The "--wrapper" command-line argument tells gdbserver to use a
2699 wrapper program to launch programs for debugging.
2701 - On PowerPC and S/390 targets, it is now possible to use a single
2702 gdbserver executable to debug both 32-bit and 64-bit programs.
2703 (This requires gdbserver itself to be built as a 64-bit executable.)
2705 - gdbserver uses the new noack protocol mode for TCP connections to
2706 reduce communications latency, if also supported and enabled in GDB.
2708 - Support for the sparc64-linux-gnu target is now included in
2711 - The amd64-linux build of gdbserver now supports debugging both
2712 32-bit and 64-bit programs.
2714 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2715 now support hardware watchpoints, and will use them automatically
2720 GDB now has support for scripting using Python. Whether this is
2721 available is determined at configure time.
2723 New GDB commands can now be written in Python.
2725 * Ada tasking support
2727 Ada tasks can now be inspected in GDB. The following commands have
2731 Print the list of Ada tasks.
2733 Print detailed information about task number N.
2735 Print the task number of the current task.
2737 Switch the context of debugging to task number N.
2739 * Support for user-defined prefixed commands. The "define" command can
2740 add new commands to existing prefixes, e.g. "target".
2742 * Multi-inferior, multi-process debugging.
2744 GDB now has generalized support for multi-inferior debugging. See
2745 "Debugging Multiple Inferiors" in the manual for more information.
2746 Although availability still depends on target support, the command
2747 set is more uniform now. The GNU/Linux specific multi-forks support
2748 has been migrated to this new framework. This implied some user
2749 visible changes; see "New commands" and also "Removed commands"
2752 * Target descriptions can now describe the target OS ABI. See the
2753 "Target Description Format" section in the user manual for more
2756 * Target descriptions can now describe "compatible" architectures
2757 to indicate that the target can execute applications for a different
2758 architecture in addition to those for the main target architecture.
2759 See the "Target Description Format" section in the user manual for
2762 * Multi-architecture debugging.
2764 GDB now includes general supports for debugging applications on
2765 hybrid systems that use more than one single processor architecture
2766 at the same time. Each such hybrid architecture still requires
2767 specific support to be added. The only hybrid architecture supported
2768 in this version of GDB is the Cell Broadband Engine.
2770 * GDB now supports integrated debugging of Cell/B.E. applications that
2771 use both the PPU and SPU architectures. To enable support for hybrid
2772 Cell/B.E. debugging, you need to configure GDB to support both the
2773 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2774 --enable-targets configure option.
2776 * Non-stop mode debugging.
2778 For some targets, GDB now supports an optional mode of operation in
2779 which you can examine stopped threads while other threads continue
2780 to execute freely. This is referred to as non-stop mode, with the
2781 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2782 section in the user manual for more information.
2784 To be able to support remote non-stop debugging, a remote stub needs
2785 to implement the non-stop mode remote protocol extensions, as
2786 described in the "Remote Non-Stop" section of the user manual. The
2787 GDB remote stub, gdbserver, has been adjusted to support these
2788 extensions on linux targets.
2790 * New commands (for set/show, see "New options" below)
2792 catch syscall [NAME(S) | NUMBER(S)]
2793 Catch system calls. Arguments, which should be names of system
2794 calls or their numbers, mean catch only those syscalls. Without
2795 arguments, every syscall will be caught. When the inferior issues
2796 any of the specified syscalls, GDB will stop and announce the system
2797 call, both when it is called and when its call returns. This
2798 feature is currently available with a native GDB running on the
2799 Linux Kernel, under the following architectures: x86, x86_64,
2800 PowerPC and PowerPC64.
2802 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2804 Search memory for a sequence of bytes.
2806 maint set python print-stack
2807 maint show python print-stack
2808 Show a stack trace when an error is encountered in a Python script.
2811 Invoke CODE by passing it to the Python interpreter.
2816 These allow macros to be defined, undefined, and listed
2820 Show operating system information about processes.
2823 List the inferiors currently under GDB's control.
2826 Switch focus to inferior number NUM.
2829 Detach from inferior number NUM.
2832 Kill inferior number NUM.
2836 set spu stop-on-load
2837 show spu stop-on-load
2838 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2840 set spu auto-flush-cache
2841 show spu auto-flush-cache
2842 Control whether to automatically flush the software-managed cache
2843 during Cell/B.E. debugging.
2845 set sh calling-convention
2846 show sh calling-convention
2847 Control the calling convention used when calling SH target functions.
2850 show debug timestamp
2851 Control display of timestamps with GDB debugging output.
2853 set disassemble-next-line
2854 show disassemble-next-line
2855 Control display of disassembled source lines or instructions when
2858 set remote noack-packet
2859 show remote noack-packet
2860 Set/show the use of remote protocol QStartNoAckMode packet. See above
2861 under "New remote packets."
2863 set remote query-attached-packet
2864 show remote query-attached-packet
2865 Control use of remote protocol `qAttached' (query-attached) packet.
2867 set remote read-siginfo-object
2868 show remote read-siginfo-object
2869 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2872 set remote write-siginfo-object
2873 show remote write-siginfo-object
2874 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2877 set remote reverse-continue
2878 show remote reverse-continue
2879 Control use of remote protocol 'bc' (reverse-continue) packet.
2881 set remote reverse-step
2882 show remote reverse-step
2883 Control use of remote protocol 'bs' (reverse-step) packet.
2885 set displaced-stepping
2886 show displaced-stepping
2887 Control displaced stepping mode. Displaced stepping is a way to
2888 single-step over breakpoints without removing them from the debuggee.
2889 Also known as "out-of-line single-stepping".
2892 show debug displaced
2893 Control display of debugging info for displaced stepping.
2895 maint set internal-error
2896 maint show internal-error
2897 Control what GDB does when an internal error is detected.
2899 maint set internal-warning
2900 maint show internal-warning
2901 Control what GDB does when an internal warning is detected.
2906 Use a wrapper program to launch programs for debugging.
2908 set multiple-symbols (all|ask|cancel)
2909 show multiple-symbols
2910 The value of this variable can be changed to adjust the debugger behavior
2911 when an expression or a breakpoint location contains an ambiguous symbol
2912 name (an overloaded function name, for instance).
2914 set breakpoint always-inserted
2915 show breakpoint always-inserted
2916 Keep breakpoints always inserted in the target, as opposed to inserting
2917 them when resuming the target, and removing them when the target stops.
2918 This option can improve debugger performance on slow remote targets.
2920 set arm fallback-mode (arm|thumb|auto)
2921 show arm fallback-mode
2922 set arm force-mode (arm|thumb|auto)
2924 These commands control how ARM GDB determines whether instructions
2925 are ARM or Thumb. The default for both settings is auto, which uses
2926 the current CPSR value for instructions without symbols; previous
2927 versions of GDB behaved as if "set arm fallback-mode arm".
2929 set disable-randomization
2930 show disable-randomization
2931 Standalone programs run with the virtual address space randomization enabled
2932 by default on some platforms. This option keeps the addresses stable across
2933 multiple debugging sessions.
2937 Control whether other threads are stopped or not when some thread hits
2942 Requests that asynchronous execution is enabled in the target, if available.
2943 In this case, it's possible to resume target in the background, and interact
2944 with GDB while the target is running. "show target-async" displays the
2945 current state of asynchronous execution of the target.
2947 set target-wide-charset
2948 show target-wide-charset
2949 The target-wide-charset is the name of the character set that GDB
2950 uses when printing characters whose type is wchar_t.
2952 set tcp auto-retry (on|off)
2954 set tcp connect-timeout
2955 show tcp connect-timeout
2956 These commands allow GDB to retry failed TCP connections to a remote stub
2957 with a specified timeout period; this is useful if the stub is launched
2958 in parallel with GDB but may not be ready to accept connections immediately.
2960 set libthread-db-search-path
2961 show libthread-db-search-path
2962 Control list of directories which GDB will search for appropriate
2965 set schedule-multiple (on|off)
2966 show schedule-multiple
2967 Allow GDB to resume all threads of all processes or only threads of
2968 the current process.
2972 Use more aggressive caching for accesses to the stack. This improves
2973 performance of remote debugging (particularly backtraces) without
2974 affecting correctness.
2976 set interactive-mode (on|off|auto)
2977 show interactive-mode
2978 Control whether GDB runs in interactive mode (on) or not (off).
2979 When in interactive mode, GDB waits for the user to answer all
2980 queries. Otherwise, GDB does not wait and assumes the default
2981 answer. When set to auto (the default), GDB determines which
2982 mode to use based on the stdin settings.
2987 For program forks, this is replaced by the new more generic `info
2988 inferiors' command. To list checkpoints, you can still use the
2989 `info checkpoints' command, which was an alias for the `info forks'
2993 Replaced by the new `inferior' command. To switch between
2994 checkpoints, you can still use the `restart' command, which was an
2995 alias for the `fork' command.
2998 This is removed, since some targets don't have a notion of
2999 processes. To switch between processes, you can still use the
3000 `inferior' command using GDB's own inferior number.
3003 For program forks, this is replaced by the new more generic `kill
3004 inferior' command. To delete a checkpoint, you can still use the
3005 `delete checkpoint' command, which was an alias for the `delete
3009 For program forks, this is replaced by the new more generic `detach
3010 inferior' command. To detach a checkpoint, you can still use the
3011 `detach checkpoint' command, which was an alias for the `detach
3014 * New native configurations
3016 x86/x86_64 Darwin i[34567]86-*-darwin*
3018 x86_64 MinGW x86_64-*-mingw*
3022 Lattice Mico32 lm32-*
3023 x86 DICOS i[34567]86-*-dicos*
3024 x86_64 DICOS x86_64-*-dicos*
3027 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3028 (mingw32ce) debugging.
3034 These commands were actually not implemented on any target.
3036 *** Changes in GDB 6.8
3038 * New native configurations
3040 NetBSD/hppa hppa*-*netbsd*
3041 Xtensa GNU/Linux xtensa*-*-linux*
3045 NetBSD/hppa hppa*-*-netbsd*
3046 Xtensa GNU/Lunux xtensa*-*-linux*
3048 * Change in command line behavior -- corefiles vs. process ids.
3050 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3051 attaching to process NUMBER fails, GDB no longer attempts to open a
3052 core file named NUMBER. Attaching to a program using the -c option
3053 is no longer supported. Instead, use the '-p' or '--pid' options.
3055 * GDB can now be built as a native debugger for debugging Windows x86
3056 (mingw32) Portable Executable (PE) programs.
3058 * Pending breakpoints no longer change their number when their address
3061 * GDB now supports breakpoints with multiple locations,
3062 including breakpoints on C++ constructors, inside C++ templates,
3063 and in inlined functions.
3065 * GDB's ability to debug optimized code has been improved. GDB more
3066 accurately identifies function bodies and lexical blocks that occupy
3067 more than one contiguous range of addresses.
3069 * Target descriptions can now describe registers for PowerPC.
3071 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3072 registers on PowerPC targets.
3074 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3075 targets even when the libthread_db library is not available.
3077 * The GDB remote stub, gdbserver, now supports the new file transfer
3078 commands (remote put, remote get, and remote delete).
3080 * The GDB remote stub, gdbserver, now supports run and attach in
3081 extended-remote mode.
3083 * hppa*64*-*-hpux11* target broken
3084 The debugger is unable to start a program and fails with the following
3085 error: "Error trying to get information about dynamic linker".
3086 The gdb-6.7 release is also affected.
3088 * GDB now supports the --enable-targets= configure option to allow
3089 building a single GDB executable that supports multiple remote
3090 target architectures.
3092 * GDB now supports debugging C and C++ programs which use the
3093 Decimal Floating Point extension. In addition, the PowerPC target
3094 now has a set of pseudo-registers to inspect decimal float values
3095 stored in two consecutive float registers.
3097 * The -break-insert MI command can optionally create pending
3100 * Improved support for debugging Ada
3101 Many improvements to the Ada language support have been made. These
3103 - Better support for Ada2005 interface types
3104 - Improved handling of arrays and slices in general
3105 - Better support for Taft-amendment types
3106 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3108 - Improved command completion in Ada
3111 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3116 set print frame-arguments (all|scalars|none)
3117 show print frame-arguments
3118 The value of this variable can be changed to control which argument
3119 values should be printed by the debugger when displaying a frame.
3124 Transfer files to and from a remote target, and delete remote files.
3131 Transfer files to and from a remote target, and delete remote files.
3133 * New remote packets
3140 Open, close, read, write, and delete files on the remote system.
3143 Attach to an existing process on the remote system, in extended-remote
3147 Run a new process on the remote system, in extended-remote mode.
3149 *** Changes in GDB 6.7
3151 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3152 bfd, libiberty and opcodes, as revealed by static analysis donated by
3153 Coverity, Inc. (http://scan.coverity.com).
3155 * When looking up multiply-defined global symbols, GDB will now prefer the
3156 symbol definition in the current shared library if it was built using the
3157 -Bsymbolic linker option.
3159 * When the Text User Interface (TUI) is not configured, GDB will now
3160 recognize the -tui command-line option and print a message that the TUI
3163 * The GDB remote stub, gdbserver, now has lower overhead for high
3164 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3166 * GDB for MIPS targets now autodetects whether a remote target provides
3167 32-bit or 64-bit register values.
3169 * Support for C++ member pointers has been improved.
3171 * GDB now understands XML target descriptions, which specify the
3172 target's overall architecture. GDB can read a description from
3173 a local file or over the remote serial protocol.
3175 * Vectors of single-byte data use a new integer type which is not
3176 automatically displayed as character or string data.
3178 * The /s format now works with the print command. It displays
3179 arrays of single-byte integers and pointers to single-byte integers
3182 * Target descriptions can now describe target-specific registers,
3183 for architectures which have implemented the support (currently
3184 only ARM, M68K, and MIPS).
3186 * GDB and the GDB remote stub, gdbserver, now support the XScale
3189 * The GDB remote stub, gdbserver, has been updated to support
3190 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3191 has been rewritten to use the standard GDB remote protocol.
3193 * GDB can now step into C++ functions which are called through thunks.
3195 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3197 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3198 layout. It also supports a TextSeg= and DataSeg= response when only
3199 segment base addresses (rather than offsets) are available.
3201 * The /i format now outputs any trailing branch delay slot instructions
3202 immediately following the last instruction within the count specified.
3204 * The GDB remote protocol "T" stop reply packet now supports a
3205 "library" response. Combined with the new "qXfer:libraries:read"
3206 packet, this response allows GDB to debug shared libraries on targets
3207 where the operating system manages the list of loaded libraries (e.g.
3208 Windows and SymbianOS).
3210 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3211 (DLLs) on Windows and Windows CE targets.
3213 * GDB now supports a faster verification that a .debug file matches its binary
3214 according to its build-id signature, if the signature is present.
3220 Enable or disable hardware flow control (RTS/CTS) on the serial port
3221 when debugging using remote targets.
3223 set mem inaccessible-by-default
3224 show mem inaccessible-by-default
3225 If the target supplies a memory map, for instance via the remote
3226 protocol's "qXfer:memory-map:read" packet, setting this variable
3227 prevents GDB from accessing memory outside the memory map. This
3228 is useful for targets with memory mapped registers or which react
3229 badly to accesses of unmapped address space.
3231 set breakpoint auto-hw
3232 show breakpoint auto-hw
3233 If the target supplies a memory map, for instance via the remote
3234 protocol's "qXfer:memory-map:read" packet, setting this variable
3235 lets GDB use hardware breakpoints automatically for memory regions
3236 where it can not use software breakpoints. This covers both the
3237 "break" command and internal breakpoints used for other commands
3238 including "next" and "finish".
3241 catch exception unhandled
3242 Stop the program execution when Ada exceptions are raised.
3245 Stop the program execution when an Ada assertion failed.
3249 Set an alternate system root for target files. This is a more
3250 general version of "set solib-absolute-prefix", which is now
3251 an alias to "set sysroot".
3254 Provide extended SPU facility status information. This set of
3255 commands is available only when debugging the Cell/B.E. SPU
3258 * New native configurations
3260 OpenBSD/sh sh*-*openbsd*
3263 unset tdesc filename
3265 Use the specified local file as an XML target description, and do
3266 not query the target for its built-in description.
3270 OpenBSD/sh sh*-*-openbsd*
3271 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3272 Toshiba Media Processor mep-elf
3274 * New remote packets
3277 Ignore the specified signals; pass them directly to the debugged program
3278 without stopping other threads or reporting them to GDB.
3280 qXfer:features:read:
3281 Read an XML target description from the target, which describes its
3286 Read or write contents of an spufs file on the target system. These
3287 packets are available only on the Cell/B.E. SPU architecture.
3289 qXfer:libraries:read:
3290 Report the loaded shared libraries. Combined with new "T" packet
3291 response, this packet allows GDB to debug shared libraries on
3292 targets where the operating system manages the list of loaded
3293 libraries (e.g. Windows and SymbianOS).
3297 Support for these obsolete configurations has been removed.
3305 i[34567]86-*-lynxos*
3306 i[34567]86-*-netware*
3307 i[34567]86-*-sco3.2v5*
3308 i[34567]86-*-sco3.2v4*
3310 i[34567]86-*-sysv4.2*
3313 i[34567]86-*-unixware2*
3314 i[34567]86-*-unixware*
3323 * Other removed features
3330 Various m68k-only ROM monitors.
3337 Various Renesas ROM monitors and debugging interfaces for SH and
3342 Support for a Macraigor serial interface to on-chip debugging.
3343 GDB does not directly support the newer parallel or USB
3348 A debug information format. The predecessor to DWARF 2 and
3349 DWARF 3, which are still supported.
3351 Support for the HP aCC compiler on HP-UX/PA-RISC
3353 SOM-encapsulated symbolic debugging information, automatic
3354 invocation of pxdb, and the aCC custom C++ ABI. This does not
3355 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3356 with aCC can still be debugged on an assembly level.
3358 MIPS ".pdr" sections
3360 A MIPS-specific format used to describe stack frame layout
3361 in debugging information.
3365 GDB could work with an older version of Guile to debug
3366 the interpreter and Scheme programs running in it.
3368 set mips stack-arg-size
3369 set mips saved-gpreg-size
3371 Use "set mips abi" to control parameter passing for MIPS.
3373 *** Changes in GDB 6.6
3378 Cell Broadband Engine SPU spu-elf
3380 * GDB can now be configured as a cross-debugger targeting native Windows
3381 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3382 running on a Windows system over TCP/IP to debug Windows programs.
3384 * The GDB remote stub, gdbserver, has been updated to support Windows and
3385 Cygwin debugging. Both single-threaded and multi-threaded programs are
3388 * The "set trust-readonly-sections" command works again. This command was
3389 broken in GDB 6.3, 6.4, and 6.5.
3391 * The "load" command now supports writing to flash memory, if the remote
3392 stub provides the required support.
3394 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3395 longer requires symbolic debug information (e.g. DWARF-2).
3400 unset substitute-path
3401 show substitute-path
3402 Manage a list of substitution rules that GDB uses to rewrite the name
3403 of the directories where the sources are located. This can be useful
3404 for instance when the sources were moved to a different location
3405 between compilation and debugging.
3409 Print each CLI command as it is executed. Each command is prefixed with
3410 a number of `+' symbols representing the nesting depth.
3411 The source command now has a `-v' option to enable the same feature.
3415 The ARM Demon monitor support (RDP protocol, "target rdp").
3417 Kernel Object Display, an embedded debugging feature which only worked with
3418 an obsolete version of Cisco IOS.
3420 The 'set download-write-size' and 'show download-write-size' commands.
3422 * New remote packets
3425 Tell a stub about GDB client features, and request remote target features.
3426 The first feature implemented is PacketSize, which allows the target to
3427 specify the size of packets it can handle - to minimize the number of
3428 packets required and improve performance when connected to a remote
3432 Fetch an OS auxilliary vector from the remote stub. This packet is a
3433 more efficient replacement for qPart:auxv:read.
3435 qXfer:memory-map:read:
3436 Fetch a memory map from the remote stub, including information about
3437 RAM, ROM, and flash memory devices.
3442 Erase and program a flash memory device.
3444 * Removed remote packets
3447 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3448 used it, and only gdbserver implemented it.
3450 *** Changes in GDB 6.5
3454 Renesas M32C/M16C m32c-elf
3456 Morpho Technologies ms1 ms1-elf
3460 init-if-undefined Initialize a convenience variable, but
3461 only if it doesn't already have a value.
3463 The following commands are presently only implemented for native GNU/Linux:
3465 checkpoint Save a snapshot of the program state.
3467 restart <n> Return the program state to a
3468 previously saved state.
3470 info checkpoints List currently saved checkpoints.
3472 delete-checkpoint <n> Delete a previously saved checkpoint.
3474 set|show detach-on-fork Tell gdb whether to detach from a newly
3475 forked process, or to keep debugging it.
3477 info forks List forks of the user program that
3478 are available to be debugged.
3480 fork <n> Switch to debugging one of several
3481 forks of the user program that are
3482 available to be debugged.
3484 delete-fork <n> Delete a fork from the list of forks
3485 that are available to be debugged (and
3486 kill the forked process).
3488 detach-fork <n> Delete a fork from the list of forks
3489 that are available to be debugged (and
3490 allow the process to continue).
3494 Morpho Technologies ms2 ms1-elf
3496 * Improved Windows host support
3498 GDB now builds as a cross debugger hosted on i686-mingw32, including
3499 native console support, and remote communications using either
3500 network sockets or serial ports.
3502 * Improved Modula-2 language support
3504 GDB can now print most types in the Modula-2 syntax. This includes:
3505 basic types, set types, record types, enumerated types, range types,
3506 pointer types and ARRAY types. Procedure var parameters are correctly
3507 printed and hexadecimal addresses and character constants are also
3508 written in the Modula-2 syntax. Best results can be obtained by using
3509 GNU Modula-2 together with the -gdwarf-2 command line option.
3513 The ARM rdi-share module.
3515 The Netware NLM debug server.
3517 *** Changes in GDB 6.4
3519 * New native configurations
3521 OpenBSD/arm arm*-*-openbsd*
3522 OpenBSD/mips64 mips64-*-openbsd*
3526 Morpho Technologies ms1 ms1-elf
3528 * New command line options
3530 --batch-silent As for --batch, but totally silent.
3531 --return-child-result The debugger will exist with the same value
3532 the child (debugged) program exited with.
3533 --eval-command COMMAND, -ex COMMAND
3534 Execute a single GDB CLI command. This may be
3535 specified multiple times and in conjunction
3536 with the --command (-x) option.
3538 * Deprecated commands removed
3540 The following commands, that were deprecated in 2000, have been
3544 set|show arm disassembly-flavor set|show arm disassembler
3545 othernames set arm disassembler
3546 set|show remotedebug set|show debug remote
3547 set|show archdebug set|show debug arch
3548 set|show eventdebug set|show debug event
3551 * New BSD user-level threads support
3553 It is now possible to debug programs using the user-level threads
3554 library on OpenBSD and FreeBSD. Currently supported (target)
3557 FreeBSD/amd64 x86_64-*-freebsd*
3558 FreeBSD/i386 i386-*-freebsd*
3559 OpenBSD/i386 i386-*-openbsd*
3561 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3562 are not yet supported.
3564 * New support for Matsushita MN10300 w/sim added
3565 (Work in progress). mn10300-elf.
3567 * REMOVED configurations and files
3569 VxWorks and the XDR protocol *-*-vxworks
3570 Motorola MCORE mcore-*-*
3571 National Semiconductor NS32000 ns32k-*-*
3573 * New "set print array-indexes" command
3575 After turning this setting "on", GDB prints the index of each element
3576 when displaying arrays. The default is "off" to preserve the previous
3579 * VAX floating point support
3581 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3583 * User-defined command support
3585 In addition to using $arg0..$arg9 for argument passing, it is now possible
3586 to use $argc to determine now many arguments have been passed. See the
3587 section on user-defined commands in the user manual for more information.
3589 *** Changes in GDB 6.3:
3591 * New command line option
3593 GDB now accepts -l followed by a number to set the timeout for remote
3596 * GDB works with GCC -feliminate-dwarf2-dups
3598 GDB now supports a more compact representation of DWARF-2 debug
3599 information using DW_FORM_ref_addr references. These are produced
3600 by GCC with the option -feliminate-dwarf2-dups and also by some
3601 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3602 to use -feliminate-dwarf2-dups.
3604 * Internationalization
3606 When supported by the host system, GDB will be built with
3607 internationalization (libintl). The task of marking up the sources is
3608 continued, we're looking forward to our first translation.
3612 Initial support for debugging programs compiled with the GNAT
3613 implementation of the Ada programming language has been integrated
3614 into GDB. In this release, support is limited to expression evaluation.
3616 * New native configurations
3618 GNU/Linux/m32r m32r-*-linux-gnu
3622 GDB's remote protocol now includes support for the 'p' packet. This
3623 packet is used to fetch individual registers from a remote inferior.
3625 * END-OF-LIFE registers[] compatibility module
3627 GDB's internal register infrastructure has been completely rewritten.
3628 The new infrastructure making possible the implementation of key new
3629 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3632 GDB 6.3 will be the last release to include the the registers[]
3633 compatibility module that allowed out-of-date configurations to
3634 continue to work. This change directly impacts the following
3644 powerpc bdm protocol
3646 Unless there is activity to revive these configurations, they will be
3647 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3649 * OBSOLETE configurations and files
3651 Configurations that have been declared obsolete in this release have
3652 been commented out. Unless there is activity to revive these
3653 configurations, the next release of GDB will have their sources
3654 permanently REMOVED.
3663 *** Changes in GDB 6.2.1:
3665 * MIPS `break main; run' gave an heuristic-fence-post warning
3667 When attempting to run even a simple program, a warning about
3668 heuristic-fence-post being hit would be reported. This problem has
3671 * MIPS IRIX 'long double' crashed GDB
3673 When examining a long double variable, GDB would get a segmentation
3674 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3675 IRIX long double values).
3679 A bug in the VAX stack code was causing problems with the "next"
3680 command. This problem has been fixed.
3682 *** Changes in GDB 6.2:
3684 * Fix for ``many threads''
3686 On GNU/Linux systems that use the NPTL threads library, a program
3687 rapidly creating and deleting threads would confuse GDB leading to the
3690 ptrace: No such process.
3691 thread_db_get_info: cannot get thread info: generic error
3693 This problem has been fixed.
3695 * "-async" and "-noasync" options removed.
3697 Support for the broken "-noasync" option has been removed (it caused
3700 * New ``start'' command.
3702 This command runs the program until the begining of the main procedure.
3704 * New BSD Kernel Data Access Library (libkvm) interface
3706 Using ``target kvm'' it is now possible to debug kernel core dumps and
3707 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3708 platforms. Currently supported (native-only) configurations are:
3710 FreeBSD/amd64 x86_64-*-freebsd*
3711 FreeBSD/i386 i?86-*-freebsd*
3712 NetBSD/i386 i?86-*-netbsd*
3713 NetBSD/m68k m68*-*-netbsd*
3714 NetBSD/sparc sparc-*-netbsd*
3715 OpenBSD/amd64 x86_64-*-openbsd*
3716 OpenBSD/i386 i?86-*-openbsd*
3717 OpenBSD/m68k m68*-openbsd*
3718 OpenBSD/sparc sparc-*-openbsd*
3720 * Signal trampoline code overhauled
3722 Many generic problems with GDB's signal handling code have been fixed.
3723 These include: backtraces through non-contiguous stacks; recognition
3724 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3725 call; backtrace through a signal trampoline; step into and out of
3726 signal handlers; and single-stepping in the signal trampoline.
3728 Please note that kernel bugs are a limiting factor here. These
3729 features have been shown to work on an s390 GNU/Linux system that
3730 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3732 * Cygwin support for DWARF 2 added.
3734 * New native configurations
3736 GNU/Linux/hppa hppa*-*-linux*
3737 OpenBSD/hppa hppa*-*-openbsd*
3738 OpenBSD/m68k m68*-*-openbsd*
3739 OpenBSD/m88k m88*-*-openbsd*
3740 OpenBSD/powerpc powerpc-*-openbsd*
3741 NetBSD/vax vax-*-netbsd*
3742 OpenBSD/vax vax-*-openbsd*
3744 * END-OF-LIFE frame compatibility module
3746 GDB's internal frame infrastructure has been completely rewritten.
3747 The new infrastructure making it possible to support key new features
3748 including DWARF 2 Call Frame Information. To aid in the task of
3749 migrating old configurations to this new infrastructure, a
3750 compatibility module, that allowed old configurations to continue to
3751 work, was also included.
3753 GDB 6.2 will be the last release to include this frame compatibility
3754 module. This change directly impacts the following configurations:
3764 Unless there is activity to revive these configurations, they will be
3765 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3767 * REMOVED configurations and files
3769 Sun 3, running SunOS 3 m68*-*-sunos3*
3770 Sun 3, running SunOS 4 m68*-*-sunos4*
3771 Sun 2, running SunOS 3 m68000-*-sunos3*
3772 Sun 2, running SunOS 4 m68000-*-sunos4*
3773 Motorola 680x0 running LynxOS m68*-*-lynxos*
3774 AT&T 3b1/Unix pc m68*-att-*
3775 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3776 decstation mips-dec-* mips-little-*
3777 riscos mips-*-riscos* mips-*-sysv*
3778 sonymips mips-sony-*
3779 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3781 *** Changes in GDB 6.1.1:
3783 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3785 The TUI (Text-mode User Interface) is now built as part of a default
3786 GDB configuration. It is enabled by either selecting the TUI with the
3787 command line option "-i=tui" or by running the separate "gdbtui"
3788 program. For more information on the TUI, see the manual "Debugging
3791 * Pending breakpoint support (also included in GDB 6.1)
3793 Support has been added to allow you to specify breakpoints in shared
3794 libraries that have not yet been loaded. If a breakpoint location
3795 cannot be found, and the "breakpoint pending" option is set to auto,
3796 GDB queries you if you wish to make the breakpoint pending on a future
3797 shared-library load. If and when GDB resolves the breakpoint symbol,
3798 the pending breakpoint is removed as one or more regular breakpoints
3801 Pending breakpoints are very useful for GCJ Java debugging.
3803 * Fixed ISO-C build problems
3805 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3806 non ISO-C code that stopped them being built using a more strict ISO-C
3807 compiler (e.g., IBM's C compiler).
3809 * Fixed build problem on IRIX 5
3811 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3812 wasn't able to compile compile on an IRIX 5 system.
3814 * Added execute permission to gdb/gdbserver/configure
3816 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3817 permission. This bug would cause configure to fail on a number of
3818 systems (Solaris, IRIX). Ref: server/519.
3820 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3822 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3823 has been updated to use constant array sizes.
3825 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3827 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3828 its generated DWARF Call Frame Info. This encoding was causing GDB to
3829 panic, that panic has been fixed. Ref: gdb/1628.
3831 * Fixed a problem when examining parameters in shared library code.
3833 When examining parameters in optimized shared library code generated
3834 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3835 not available''. GDB now correctly displays the variable's value.
3837 *** Changes in GDB 6.1:
3839 * Removed --with-mmalloc
3841 Support for the mmalloc memory manager has been removed, as it
3842 conflicted with the internal gdb byte cache.
3844 * Changes in AMD64 configurations
3846 The AMD64 target now includes the %cs and %ss registers. As a result
3847 the AMD64 remote protocol has changed; this affects the floating-point
3848 and SSE registers. If you rely on those registers for your debugging,
3849 you should upgrade gdbserver on the remote side.
3851 * Revised SPARC target
3853 The SPARC target has been completely revised, incorporating the
3854 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3855 support for LynxOS and SunOS 4 has been dropped. Calling functions
3856 from within GDB on operating systems with a non-executable stack
3857 (Solaris, OpenBSD) now works.
3861 GDB has a new C++ demangler which does a better job on the mangled
3862 names generated by current versions of g++. It also runs faster, so
3863 with this and other changes gdb should now start faster on large C++
3866 * DWARF 2 Location Expressions
3868 GDB support for location expressions has been extended to support function
3869 arguments and frame bases. Older versions of GDB could crash when they
3872 * C++ nested types and namespaces
3874 GDB's support for nested types and namespaces in C++ has been
3875 improved, especially if you use the DWARF 2 debugging format. (This
3876 is the default for recent versions of GCC on most platforms.)
3877 Specifically, if you have a class "Inner" defined within a class or
3878 namespace "Outer", then GDB realizes that the class's name is
3879 "Outer::Inner", not simply "Inner". This should greatly reduce the
3880 frequency of complaints about not finding RTTI symbols. In addition,
3881 if you are stopped at inside of a function defined within a namespace,
3882 GDB modifies its name lookup accordingly.
3884 * New native configurations
3886 NetBSD/amd64 x86_64-*-netbsd*
3887 OpenBSD/amd64 x86_64-*-openbsd*
3888 OpenBSD/alpha alpha*-*-openbsd*
3889 OpenBSD/sparc sparc-*-openbsd*
3890 OpenBSD/sparc64 sparc64-*-openbsd*
3892 * New debugging protocols
3894 M32R with SDI protocol m32r-*-elf*
3896 * "set prompt-escape-char" command deleted.
3898 The command "set prompt-escape-char" has been deleted. This command,
3899 and its very obscure effet on GDB's prompt, was never documented,
3900 tested, nor mentioned in the NEWS file.
3902 * OBSOLETE configurations and files
3904 Configurations that have been declared obsolete in this release have
3905 been commented out. Unless there is activity to revive these
3906 configurations, the next release of GDB will have their sources
3907 permanently REMOVED.
3909 Sun 3, running SunOS 3 m68*-*-sunos3*
3910 Sun 3, running SunOS 4 m68*-*-sunos4*
3911 Sun 2, running SunOS 3 m68000-*-sunos3*
3912 Sun 2, running SunOS 4 m68000-*-sunos4*
3913 Motorola 680x0 running LynxOS m68*-*-lynxos*
3914 AT&T 3b1/Unix pc m68*-att-*
3915 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3916 decstation mips-dec-* mips-little-*
3917 riscos mips-*-riscos* mips-*-sysv*
3918 sonymips mips-sony-*
3919 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3921 * REMOVED configurations and files
3923 SGI Irix-4.x mips-sgi-irix4 or iris4
3924 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3925 Z8000 simulator z8k-zilog-none or z8ksim
3926 Matsushita MN10200 w/simulator mn10200-*-*
3927 H8/500 simulator h8500-hitachi-hms or h8500hms
3928 HP/PA running BSD hppa*-*-bsd*
3929 HP/PA running OSF/1 hppa*-*-osf*
3930 HP/PA Pro target hppa*-*-pro*
3931 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3932 386BSD i[3456]86-*-bsd*
3933 Sequent family i[3456]86-sequent-sysv4*
3934 i[3456]86-sequent-sysv*
3935 i[3456]86-sequent-bsd*
3936 SPARC running LynxOS sparc-*-lynxos*
3937 SPARC running SunOS 4 sparc-*-sunos4*
3938 Tsqware Sparclet sparclet-*-*
3939 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3941 *** Changes in GDB 6.0:
3945 Support for debugging the Objective-C programming language has been
3946 integrated into GDB.
3948 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3950 DWARF 2's Call Frame Information makes available compiler generated
3951 information that more exactly describes the program's run-time stack.
3952 By using this information, GDB is able to provide more robust stack
3955 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3956 have been updated to use a new backtrace mechanism which includes
3957 DWARF 2 CFI support.
3961 GDB's remote protocol has been extended to include support for hosted
3962 file I/O (where the remote target uses GDB's file system). See GDB's
3963 remote protocol documentation for details.
3965 * All targets using the new architecture framework.
3967 All of GDB's targets have been updated to use the new internal
3968 architecture framework. The way is now open for future GDB releases
3969 to include cross-architecture native debugging support (i386 on amd64,
3972 * GNU/Linux's Thread Local Storage (TLS)
3974 GDB now includes support for for the GNU/Linux implementation of
3975 per-thread variables.
3977 * GNU/Linux's Native POSIX Thread Library (NPTL)
3979 GDB's thread code has been updated to work with either the new
3980 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3982 * Separate debug info.
3984 GDB, in conjunction with BINUTILS, now supports a mechanism for
3985 automatically loading debug information from a separate file. Instead
3986 of shipping full debug and non-debug versions of system libraries,
3987 system integrators can now instead ship just the stripped libraries
3988 and optional debug files.
3990 * DWARF 2 Location Expressions
3992 DWARF 2 Location Expressions allow the compiler to more completely
3993 describe the location of variables (even in optimized code) to the
3996 GDB now includes preliminary support for location expressions (support
3997 for DW_OP_piece is still missing).
4001 A number of long standing bugs that caused GDB to die while starting a
4002 Java application have been fixed. GDB's Java support is now
4003 considered "useable".
4005 * GNU/Linux support for fork, vfork, and exec.
4007 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4008 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4011 * GDB supports logging output to a file
4013 There are two new commands, "set logging" and "show logging", which can be
4014 used to capture GDB's output to a file.
4016 * The meaning of "detach" has changed for gdbserver
4018 The "detach" command will now resume the application, as documented. To
4019 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4022 * d10v, m68hc11 `regs' command deprecated
4024 The `info registers' command has been updated so that it displays the
4025 registers using a format identical to the old `regs' command.
4029 A new command, "maint set profile on/off", has been added. This command can
4030 be used to enable or disable profiling while running GDB, to profile a
4031 session or a set of commands. In addition there is a new configure switch,
4032 "--enable-profiling", which will cause GDB to be compiled with profiling
4033 data, for more informative profiling results.
4035 * Default MI syntax changed to "mi2".
4037 The default MI (machine interface) syntax, enabled by the command line
4038 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4039 "mi1", can be enabled by specifying the option "-i=mi1".
4041 Support for the original "mi0" syntax (included in GDB 5.0) has been
4044 Fix for gdb/192: removed extraneous space when displaying frame level.
4045 Fix for gdb/672: update changelist is now output in mi list format.
4046 Fix for gdb/702: a -var-assign that updates the value now shows up
4047 in a subsequent -var-update.
4049 * New native configurations.
4051 FreeBSD/amd64 x86_64-*-freebsd*
4053 * Multi-arched targets.
4055 HP/PA HPUX11 hppa*-*-hpux*
4056 Renesas M32R/D w/simulator m32r-*-elf*
4058 * OBSOLETE configurations and files
4060 Configurations that have been declared obsolete in this release have
4061 been commented out. Unless there is activity to revive these
4062 configurations, the next release of GDB will have their sources
4063 permanently REMOVED.
4065 Z8000 simulator z8k-zilog-none or z8ksim
4066 Matsushita MN10200 w/simulator mn10200-*-*
4067 H8/500 simulator h8500-hitachi-hms or h8500hms
4068 HP/PA running BSD hppa*-*-bsd*
4069 HP/PA running OSF/1 hppa*-*-osf*
4070 HP/PA Pro target hppa*-*-pro*
4071 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4072 Sequent family i[3456]86-sequent-sysv4*
4073 i[3456]86-sequent-sysv*
4074 i[3456]86-sequent-bsd*
4075 Tsqware Sparclet sparclet-*-*
4076 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4078 * REMOVED configurations and files
4081 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4082 IBM AIX PS/2 i[3456]86-*-aix
4083 i386 running Mach 3.0 i[3456]86-*-mach3*
4084 i386 running Mach i[3456]86-*-mach*
4085 i386 running OSF/1 i[3456]86-*osf1mk*
4086 HP/Apollo 68k Family m68*-apollo*-sysv*,
4088 m68*-hp-bsd*, m68*-hp-hpux*
4089 Argonaut Risc Chip (ARC) arc-*-*
4090 Mitsubishi D30V d30v-*-*
4091 Fujitsu FR30 fr30-*-elf*
4092 OS/9000 i[34]86-*-os9k
4093 I960 with MON960 i960-*-coff
4095 * MIPS $fp behavior changed
4097 The convenience variable $fp, for the MIPS, now consistently returns
4098 the address of the current frame's base. Previously, depending on the
4099 context, $fp could refer to either $sp or the current frame's base
4100 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4101 The GNU Source-Level Debugger''.
4103 *** Changes in GDB 5.3:
4105 * GNU/Linux shared library multi-threaded performance improved.
4107 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4108 `/proc', in preference to `ptrace' for memory reads. This may result
4109 in an improvement in the start-up time of multi-threaded, shared
4110 library applications when run under GDB. One GDB user writes: ``loads
4111 shared libs like mad''.
4113 * ``gdbserver'' now supports multi-threaded applications on some targets
4115 Support for debugging multi-threaded applications which use
4116 the GNU/Linux LinuxThreads package has been added for
4117 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4118 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4120 * GDB now supports C/C++ preprocessor macros.
4122 GDB now expands preprocessor macro invocations in C/C++ expressions,
4123 and provides various commands for showing macro definitions and how
4126 The new command `macro expand EXPRESSION' expands any macro
4127 invocations in expression, and shows the result.
4129 The new command `show macro MACRO-NAME' shows the definition of the
4130 macro named MACRO-NAME, and where it was defined.
4132 Most compilers don't include information about macros in the debugging
4133 information by default. In GCC 3.1, for example, you need to compile
4134 your program with the options `-gdwarf-2 -g3'. If the macro
4135 information is present in the executable, GDB will read it.
4137 * Multi-arched targets.
4139 DEC Alpha (partial) alpha*-*-*
4140 DEC VAX (partial) vax-*-*
4142 National Semiconductor NS32000 (partial) ns32k-*-*
4143 Motorola 68000 (partial) m68k-*-*
4144 Motorola MCORE mcore-*-*
4148 Fujitsu FRV architecture added by Red Hat frv*-*-*
4151 * New native configurations
4153 Alpha NetBSD alpha*-*-netbsd*
4154 SH NetBSD sh*-*-netbsdelf*
4155 MIPS NetBSD mips*-*-netbsd*
4156 UltraSPARC NetBSD sparc64-*-netbsd*
4158 * OBSOLETE configurations and files
4160 Configurations that have been declared obsolete in this release have
4161 been commented out. Unless there is activity to revive these
4162 configurations, the next release of GDB will have their sources
4163 permanently REMOVED.
4165 Mitsubishi D30V d30v-*-*
4166 OS/9000 i[34]86-*-os9k
4167 IBM AIX PS/2 i[3456]86-*-aix
4168 Fujitsu FR30 fr30-*-elf*
4169 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4170 Argonaut Risc Chip (ARC) arc-*-*
4171 i386 running Mach 3.0 i[3456]86-*-mach3*
4172 i386 running Mach i[3456]86-*-mach*
4173 i386 running OSF/1 i[3456]86-*osf1mk*
4174 HP/Apollo 68k Family m68*-apollo*-sysv*,
4176 m68*-hp-bsd*, m68*-hp-hpux*
4177 I960 with MON960 i960-*-coff
4179 * OBSOLETE languages
4181 CHILL, a Pascal like language used by telecommunications companies.
4183 * REMOVED configurations and files
4185 AMD 29k family via UDI a29k-amd-udi, udi29k
4186 A29K VxWorks a29k-*-vxworks
4187 AMD 29000 embedded, using EBMON a29k-none-none
4188 AMD 29000 embedded with COFF a29k-none-coff
4189 AMD 29000 embedded with a.out a29k-none-aout
4191 testsuite/gdb.hp/gdb.threads-hp/ directory
4193 * New command "set max-user-call-depth <nnn>"
4195 This command allows the user to limit the call depth of user-defined
4196 commands. The default is 1024.
4198 * Changes in FreeBSD/i386 native debugging.
4200 Support for the "generate-core-file" has been added.
4202 * New commands "dump", "append", and "restore".
4204 These commands allow data to be copied from target memory
4205 to a bfd-format or binary file (dump and append), and back
4206 from a file into memory (restore).
4208 * Improved "next/step" support on multi-processor Alpha Tru64.
4210 The previous single-step mechanism could cause unpredictable problems,
4211 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4212 of a software single-step mechanism prevents this.
4214 *** Changes in GDB 5.2.1:
4222 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4223 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4224 Fix, by Joel Brobecker imported from mainline.
4226 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4227 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4228 Fix, by Fred Fish, imported from mainline.
4230 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4231 Surprisingly enough, it works now.
4232 By Michal Ludvig, imported from mainline.
4234 i386 hardware watchpoint support:
4235 avoid misses on second run for some targets.
4236 By Pierre Muller, imported from mainline.
4238 *** Changes in GDB 5.2:
4240 * New command "set trust-readonly-sections on[off]".
4242 This command is a hint that tells gdb that read-only sections
4243 really are read-only (ie. that their contents will not change).
4244 In this mode, gdb will go to the object file rather than the
4245 target to read memory from read-only sections (such as ".text").
4246 This can be a significant performance improvement on some
4247 (notably embedded) targets.
4249 * New command "generate-core-file" (or "gcore").
4251 This new gdb command allows the user to drop a core file of the child
4252 process state at any time. So far it's been implemented only for
4253 GNU/Linux and Solaris, but should be relatively easily ported to other
4254 hosts. Argument is core file name (defaults to core.<pid>).
4256 * New command line option
4258 GDB now accepts --pid or -p followed by a process id.
4260 * Change in command line behavior -- corefiles vs. process ids.
4262 There is a subtle behavior in the way in which GDB handles
4263 command line arguments. The first non-flag argument is always
4264 a program to debug, but the second non-flag argument may either
4265 be a corefile or a process id. Previously, GDB would attempt to
4266 open the second argument as a corefile, and if that failed, would
4267 issue a superfluous error message and then attempt to attach it as
4268 a process. Now, if the second argument begins with a non-digit,
4269 it will be treated as a corefile. If it begins with a digit,
4270 GDB will attempt to attach it as a process, and if no such process
4271 is found, will then attempt to open it as a corefile.
4273 * Changes in ARM configurations.
4275 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4276 configuration is fully multi-arch.
4278 * New native configurations
4280 ARM NetBSD arm*-*-netbsd*
4281 x86 OpenBSD i[3456]86-*-openbsd*
4282 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4283 Sparc64 running FreeBSD sparc64-*-freebsd*
4287 Sanyo XStormy16 xstormy16-elf
4289 * OBSOLETE configurations and files
4291 Configurations that have been declared obsolete in this release have
4292 been commented out. Unless there is activity to revive these
4293 configurations, the next release of GDB will have their sources
4294 permanently REMOVED.
4296 AMD 29k family via UDI a29k-amd-udi, udi29k
4297 A29K VxWorks a29k-*-vxworks
4298 AMD 29000 embedded, using EBMON a29k-none-none
4299 AMD 29000 embedded with COFF a29k-none-coff
4300 AMD 29000 embedded with a.out a29k-none-aout
4302 testsuite/gdb.hp/gdb.threads-hp/ directory
4304 * REMOVED configurations and files
4306 TI TMS320C80 tic80-*-*
4308 PowerPC Solaris powerpcle-*-solaris*
4309 PowerPC Windows NT powerpcle-*-cygwin32
4310 PowerPC Netware powerpc-*-netware*
4311 Harris/CXUX m88k m88*-harris-cxux*
4312 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4313 ns32k-utek-sysv* ns32k-utek-*
4314 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4315 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4316 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4317 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4318 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4320 * Changes to command line processing
4322 The new `--args' feature can be used to specify command-line arguments
4323 for the inferior from gdb's command line.
4325 * Changes to key bindings
4327 There is a new `operate-and-get-next' function bound to `C-o'.
4329 *** Changes in GDB 5.1.1
4331 Fix compile problem on DJGPP.
4333 Fix a problem with floating-point registers on the i386 being
4336 Fix to stop GDB crashing on .debug_str debug info.
4338 Numerous documentation fixes.
4340 Numerous testsuite fixes.
4342 *** Changes in GDB 5.1:
4344 * New native configurations
4346 Alpha FreeBSD alpha*-*-freebsd*
4347 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4348 MIPS GNU/Linux mips*-*-linux*
4349 MIPS SGI Irix 6.x mips*-sgi-irix6*
4350 ia64 AIX ia64-*-aix*
4351 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4355 Motorola 68HC11 and 68HC12 m68hc11-elf
4357 UltraSparc running GNU/Linux sparc64-*-linux*
4359 * OBSOLETE configurations and files
4361 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4362 Harris/CXUX m88k m88*-harris-cxux*
4363 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4364 ns32k-utek-sysv* ns32k-utek-*
4365 TI TMS320C80 tic80-*-*
4367 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4368 PowerPC Solaris powerpcle-*-solaris*
4369 PowerPC Windows NT powerpcle-*-cygwin32
4370 PowerPC Netware powerpc-*-netware*
4371 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4372 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4373 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4374 Apple Macintosh (MPW) host N/A
4376 stuff.c (Program to stuff files into a specially prepared space in kdb)
4377 kdb-start.c (Main loop for the standalone kernel debugger)
4379 Configurations that have been declared obsolete in this release have
4380 been commented out. Unless there is activity to revive these
4381 configurations, the next release of GDB will have their sources
4382 permanently REMOVED.
4384 * REMOVED configurations and files
4386 Altos 3068 m68*-altos-*
4387 Convex c1-*-*, c2-*-*
4389 ARM RISCix arm-*-* (as host)
4393 * GDB has been converted to ISO C.
4395 GDB's source code has been converted to ISO C. In particular, the
4396 sources are fully protoized, and rely on standard headers being
4401 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4403 * The MI enabled by default.
4405 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4406 revised and enabled by default. Packages which use GDB as a debugging
4407 engine behind a UI or another front end are encouraged to switch to
4408 using the GDB/MI interface, instead of the old annotations interface
4409 which is now deprecated.
4411 * Support for debugging Pascal programs.
4413 GDB now includes support for debugging Pascal programs. The following
4414 main features are supported:
4416 - Pascal-specific data types such as sets;
4418 - automatic recognition of Pascal sources based on file-name
4421 - Pascal-style display of data types, variables, and functions;
4423 - a Pascal expression parser.
4425 However, some important features are not yet supported.
4427 - Pascal string operations are not supported at all;
4429 - there are some problems with boolean types;
4431 - Pascal type hexadecimal constants are not supported
4432 because they conflict with the internal variables format;
4434 - support for Pascal objects and classes is not full yet;
4436 - unlike Pascal, GDB is case-sensitive for symbol names.
4438 * Changes in completion.
4440 Commands such as `shell', `run' and `set args', which pass arguments
4441 to inferior programs, now complete on file names, similar to what
4442 users expect at the shell prompt.
4444 Commands which accept locations, such as `disassemble', `print',
4445 `breakpoint', `until', etc. now complete on filenames as well as
4446 program symbols. Thus, if you type "break foob TAB", and the source
4447 files linked into the programs include `foobar.c', that file name will
4448 be one of the candidates for completion. However, file names are not
4449 considered for completion after you typed a colon that delimits a file
4450 name from a name of a function in that file, as in "break foo.c:bar".
4452 `set demangle-style' completes on available demangling styles.
4454 * New platform-independent commands:
4456 It is now possible to define a post-hook for a command as well as a
4457 hook that runs before the command. For more details, see the
4458 documentation of `hookpost' in the GDB manual.
4460 * Changes in GNU/Linux native debugging.
4462 Support for debugging multi-threaded programs has been completely
4463 revised for all platforms except m68k and sparc. You can now debug as
4464 many threads as your system allows you to have.
4466 Attach/detach is supported for multi-threaded programs.
4468 Support for SSE registers was added for x86. This doesn't work for
4469 multi-threaded programs though.
4471 * Changes in MIPS configurations.
4473 Multi-arch support is enabled for all MIPS configurations.
4475 GDB can now be built as native debugger on SGI Irix 6.x systems for
4476 debugging n32 executables. (Debugging 64-bit executables is not yet
4479 * Unified support for hardware watchpoints in all x86 configurations.
4481 Most (if not all) native x86 configurations support hardware-assisted
4482 breakpoints and watchpoints in a unified manner. This support
4483 implements debug register sharing between watchpoints, which allows to
4484 put a virtually infinite number of watchpoints on the same address,
4485 and also supports watching regions up to 16 bytes with several debug
4488 The new maintenance command `maintenance show-debug-regs' toggles
4489 debugging print-outs in functions that insert, remove, and test
4490 watchpoints and hardware breakpoints.
4492 * Changes in the DJGPP native configuration.
4494 New command ``info dos sysinfo'' displays assorted information about
4495 the CPU, OS, memory, and DPMI server.
4497 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4498 display information about segment descriptors stored in GDT, LDT, and
4501 New commands ``info dos pde'' and ``info dos pte'' display entries
4502 from Page Directory and Page Tables (for now works with CWSDPMI only).
4503 New command ``info dos address-pte'' displays the Page Table entry for
4504 a given linear address.
4506 GDB can now pass command lines longer than 126 characters to the
4507 program being debugged (requires an update to the libdbg.a library
4508 which is part of the DJGPP development kit).
4510 DWARF2 debug info is now supported.
4512 It is now possible to `step' and `next' through calls to `longjmp'.
4514 * Changes in documentation.
4516 All GDB documentation was converted to GFDL, the GNU Free
4517 Documentation License.
4519 Tracepoints-related commands are now fully documented in the GDB
4522 TUI, the Text-mode User Interface, is now documented in the manual.
4524 Tracepoints-related commands are now fully documented in the GDB
4527 The "GDB Internals" manual now has an index. It also includes
4528 documentation of `ui_out' functions, GDB coding standards, x86
4529 hardware watchpoints, and memory region attributes.
4531 * GDB's version number moved to ``version.in''
4533 The Makefile variable VERSION has been replaced by the file
4534 ``version.in''. People creating GDB distributions should update the
4535 contents of this file.
4539 GUD support is now a standard part of the EMACS distribution.
4541 *** Changes in GDB 5.0:
4543 * Improved support for debugging FP programs on x86 targets
4545 Unified and much-improved support for debugging floating-point
4546 programs on all x86 targets. In particular, ``info float'' now
4547 displays the FP registers in the same format on all x86 targets, with
4548 greater level of detail.
4550 * Improvements and bugfixes in hardware-assisted watchpoints
4552 It is now possible to watch array elements, struct members, and
4553 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4554 on x86 targets no longer erroneously trigger when the address is
4557 * Improvements in the native DJGPP version of GDB
4559 The distribution now includes all the scripts and auxiliary files
4560 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4561 machines ``out of the box''.
4563 The DJGPP version can now debug programs that use signals. It is
4564 possible to catch signals that happened in the debuggee, deliver
4565 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4566 would kill the program being debugged.) Programs that hook hardware
4567 interrupts (keyboard, timer, etc.) can also be debugged.
4569 It is now possible to debug DJGPP programs that redirect their
4570 standard handles or switch them to raw (as opposed to cooked) mode, or
4571 even close them. The command ``run < foo > bar'' works as expected,
4572 and ``info terminal'' reports useful information about the debuggee's
4573 terminal, including raw/cooked mode, redirection, etc.
4575 The DJGPP version now uses termios functions for console I/O, which
4576 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4579 DOS-style file names with drive letters are now fully supported by
4582 It is now possible to debug DJGPP programs that switch their working
4583 directory. It is also possible to rerun the debuggee any number of
4584 times without restarting GDB; thus, you can use the same setup,
4585 breakpoints, etc. for many debugging sessions.
4587 * New native configurations
4589 ARM GNU/Linux arm*-*-linux*
4590 PowerPC GNU/Linux powerpc-*-linux*
4594 Motorola MCore mcore-*-*
4595 x86 VxWorks i[3456]86-*-vxworks*
4596 PowerPC VxWorks powerpc-*-vxworks*
4597 TI TMS320C80 tic80-*-*
4599 * OBSOLETE configurations
4601 Altos 3068 m68*-altos-*
4602 Convex c1-*-*, c2-*-*
4604 ARM RISCix arm-*-* (as host)
4607 Configurations that have been declared obsolete will be commented out,
4608 but the code will be left in place. If there is no activity to revive
4609 these configurations before the next release of GDB, the sources will
4610 be permanently REMOVED.
4612 * Gould support removed
4614 Support for the Gould PowerNode and NP1 has been removed.
4616 * New features for SVR4
4618 On SVR4 native platforms (such as Solaris), if you attach to a process
4619 without first loading a symbol file, GDB will now attempt to locate and
4620 load symbols from the running process's executable file.
4622 * Many C++ enhancements
4624 C++ support has been greatly improved. Overload resolution now works properly
4625 in almost all cases. RTTI support is on the way.
4627 * Remote targets can connect to a sub-program
4629 A popen(3) style serial-device has been added. This device starts a
4630 sub-process (such as a stand-alone simulator) and then communicates
4631 with that. The sub-program to run is specified using the syntax
4632 ``|<program> <args>'' vis:
4634 (gdb) set remotedebug 1
4635 (gdb) target extended-remote |mn10300-elf-sim program-args
4637 * MIPS 64 remote protocol
4639 A long standing bug in the mips64 remote protocol where by GDB
4640 expected certain 32 bit registers (ex SR) to be transfered as 32
4641 instead of 64 bits has been fixed.
4643 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4644 added to provide backward compatibility with older versions of GDB.
4646 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4648 The command ``set remotebinarydownload'' command has been replaced by
4649 ``set remote X-packet''. Other commands in ``set remote'' family
4650 include ``set remote P-packet''.
4652 * Breakpoint commands accept ranges.
4654 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4655 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4656 ``tracepoint passcount'' also accepts a range of tracepoints.
4658 * ``apropos'' command added.
4660 The ``apropos'' command searches through command names and
4661 documentation strings, printing out matches, making it much easier to
4662 try to find a command that does what you are looking for.
4666 A new machine oriented interface (MI) has been added to GDB. This
4667 interface is designed for debug environments running GDB as a separate
4668 process. This is part of the long term libGDB project. See the
4669 "GDB/MI" chapter of the GDB manual for further information. It can be
4670 enabled by configuring with:
4672 .../configure --enable-gdbmi
4674 *** Changes in GDB-4.18:
4676 * New native configurations
4678 HP-UX 10.20 hppa*-*-hpux10.20
4679 HP-UX 11.x hppa*-*-hpux11.0*
4680 M68K GNU/Linux m68*-*-linux*
4684 Fujitsu FR30 fr30-*-elf*
4685 Intel StrongARM strongarm-*-*
4686 Mitsubishi D30V d30v-*-*
4688 * OBSOLETE configurations
4690 Gould PowerNode, NP1 np1-*-*, pn-*-*
4692 Configurations that have been declared obsolete will be commented out,
4693 but the code will be left in place. If there is no activity to revive
4694 these configurations before the next release of GDB, the sources will
4695 be permanently REMOVED.
4699 As a compatibility experiment, GDB's source files buildsym.h and
4700 buildsym.c have been converted to pure standard C, no longer
4701 containing any K&R compatibility code. We believe that all systems in
4702 use today either come with a standard C compiler, or have a GCC port
4703 available. If this is not true, please report the affected
4704 configuration to bug-gdb@gnu.org immediately. See the README file for
4705 information about getting a standard C compiler if you don't have one
4710 GDB now uses readline 2.2.
4712 * set extension-language
4714 You can now control the mapping between filename extensions and source
4715 languages by using the `set extension-language' command. For instance,
4716 you can ask GDB to treat .c files as C++ by saying
4717 set extension-language .c c++
4718 The command `info extensions' lists all of the recognized extensions
4719 and their associated languages.
4721 * Setting processor type for PowerPC and RS/6000
4723 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4724 you can use the `set processor' command to specify what variant of the
4725 PowerPC family you are debugging. The command
4729 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4730 following PowerPC and RS6000 variants:
4732 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4733 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4735 403GC IBM PowerPC 403GC
4736 505 Motorola PowerPC 505
4737 860 Motorola PowerPC 860 or 850
4738 601 Motorola PowerPC 601
4739 602 Motorola PowerPC 602
4740 603 Motorola/IBM PowerPC 603 or 603e
4741 604 Motorola PowerPC 604 or 604e
4742 750 Motorola/IBM PowerPC 750 or 750
4744 At the moment, this command just tells GDB what to name the
4745 special-purpose processor registers. Since almost all the affected
4746 registers are inaccessible to user-level programs, this command is
4747 only useful for remote debugging in its present form.
4751 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4752 more extensive support for HP-UX. Added features include shared
4753 library support, kernel threads and hardware watchpoints for 11.00,
4754 support for HP's ANSI C and C++ compilers, and a compatibility mode
4755 for xdb and dbx commands.
4759 HP's donation includes the new concept of catchpoints, which is a
4760 generalization of the old catch command. On HP-UX, it is now possible
4761 to catch exec, fork, and vfork, as well as library loading.
4763 This means that the existing catch command has changed; its first
4764 argument now specifies the type of catch to be set up. See the
4765 output of "help catch" for a list of catchpoint types.
4767 * Debugging across forks
4769 On HP-UX, you can choose which process to debug when a fork() happens
4774 HP has donated a curses-based terminal user interface (TUI). To get
4775 it, build with --enable-tui. Although this can be enabled for any
4776 configuration, at present it only works for native HP debugging.
4778 * GDB remote protocol additions
4780 A new protocol packet 'X' that writes binary data is now available.
4781 Default behavior is to try 'X', then drop back to 'M' if the stub
4782 fails to respond. The settable variable `remotebinarydownload'
4783 allows explicit control over the use of 'X'.
4785 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4786 full 64-bit address. The command
4788 set remoteaddresssize 32
4790 can be used to revert to the old behaviour. For existing remote stubs
4791 the change should not be noticed, as the additional address information
4794 In order to assist in debugging stubs, you may use the maintenance
4795 command `packet' to send any text string to the stub. For instance,
4797 maint packet heythere
4799 sends the packet "$heythere#<checksum>". Note that it is very easy to
4800 disrupt a debugging session by sending the wrong packet at the wrong
4803 The compare-sections command allows you to compare section data on the
4804 target to what is in the executable file without uploading or
4805 downloading, by comparing CRC checksums.
4807 * Tracing can collect general expressions
4809 You may now collect general expressions at tracepoints. This requires
4810 further additions to the target-side stub; see tracepoint.c and
4811 doc/agentexpr.texi for further details.
4813 * mask-address variable for Mips
4815 For Mips targets, you may control the zeroing of the upper 32 bits of
4816 a 64-bit address by entering `set mask-address on'. This is mainly
4817 of interest to users of embedded R4xxx and R5xxx processors.
4819 * Higher serial baud rates
4821 GDB's serial code now allows you to specify baud rates 57600, 115200,
4822 230400, and 460800 baud. (Note that your host system may not be able
4823 to achieve all of these rates.)
4827 The i960 configuration now includes an initial implementation of a
4828 builtin simulator, contributed by Jim Wilson.
4831 *** Changes in GDB-4.17:
4833 * New native configurations
4835 Alpha GNU/Linux alpha*-*-linux*
4836 Unixware 2.x i[3456]86-unixware2*
4837 Irix 6.x mips*-sgi-irix6*
4838 PowerPC GNU/Linux powerpc-*-linux*
4839 PowerPC Solaris powerpcle-*-solaris*
4840 Sparc GNU/Linux sparc-*-linux*
4841 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4845 Argonaut Risc Chip (ARC) arc-*-*
4846 Hitachi H8/300S h8300*-*-*
4847 Matsushita MN10200 w/simulator mn10200-*-*
4848 Matsushita MN10300 w/simulator mn10300-*-*
4849 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4850 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4851 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4852 Mitsubishi D10V w/simulator d10v-*-*
4853 Mitsubishi M32R/D w/simulator m32r-*-elf*
4854 Tsqware Sparclet sparclet-*-*
4855 NEC V850 w/simulator v850-*-*
4857 * New debugging protocols
4859 ARM with RDI protocol arm*-*-*
4860 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4861 DDB and LSI variants of PMON protocol mips*-*-*
4862 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4863 PowerPC with SDS protocol powerpc{,le}-*-eabi
4864 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4868 All configurations can now understand and use the DWARF 2 debugging
4869 format. The choice is automatic, if the symbol file contains DWARF 2
4874 GDB now includes basic Java language support. This support is
4875 only useful with Java compilers that produce native machine code.
4877 * solib-absolute-prefix and solib-search-path
4879 For SunOS and SVR4 shared libraries, you may now set the prefix for
4880 loading absolute shared library symbol files, and the search path for
4881 locating non-absolute shared library symbol files.
4883 * Live range splitting
4885 GDB can now effectively debug code for which GCC has performed live
4886 range splitting as part of its optimization. See gdb/doc/LRS for
4887 more details on the expected format of the stabs information.
4891 GDB's support for the GNU Hurd, including thread debugging, has been
4892 updated to work with current versions of the Hurd.
4896 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4897 instruction set. ARM GDB automatically detects when Thumb
4898 instructions are in use, and adjusts disassembly and backtracing
4903 GDB's MIPS target configurations now handle the MIP16 16-bit
4908 GDB now includes support for overlays; if an executable has been
4909 linked such that multiple sections are based at the same address, GDB
4910 will decide which section to use for symbolic info. You can choose to
4911 control the decision manually, using overlay commands, or implement
4912 additional target-side support and use "overlay load-target" to bring
4913 in the overlay mapping. Do "help overlay" for more detail.
4917 The command "info symbol <address>" displays information about
4918 the symbol at the specified address.
4922 The standard remote protocol now includes an extension that allows
4923 asynchronous collection and display of trace data. This requires
4924 extensive support in the target-side debugging stub. Tracing mode
4925 includes a new interaction mode in GDB and new commands: see the
4926 file tracepoint.c for more details.
4930 Configurations for embedded MIPS now include a simulator contributed
4931 by Cygnus Solutions. The simulator supports the instruction sets
4932 of most MIPS variants.
4936 Sparc configurations may now include the ERC32 simulator contributed
4937 by the European Space Agency. The simulator is not built into
4938 Sparc targets by default; configure with --enable-sim to include it.
4942 For target configurations that may include multiple variants of a
4943 basic architecture (such as MIPS and SH), you may now set the
4944 architecture explicitly. "set arch" sets, "info arch" lists
4945 the possible architectures.
4947 *** Changes in GDB-4.16:
4949 * New native configurations
4951 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4952 M68K NetBSD m68k-*-netbsd*
4953 PowerPC AIX 4.x powerpc-*-aix*
4954 PowerPC MacOS powerpc-*-macos*
4955 PowerPC Windows NT powerpcle-*-cygwin32
4956 RS/6000 AIX 4.x rs6000-*-aix4*
4960 ARM with RDP protocol arm-*-*
4961 I960 with MON960 i960-*-coff
4962 MIPS VxWorks mips*-*-vxworks*
4963 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4964 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4966 Matra Sparclet sparclet-*-*
4970 The powerpc-eabi configuration now includes the PSIM simulator,
4971 contributed by Andrew Cagney, with assistance from Mike Meissner.
4972 PSIM is a very elaborate model of the PowerPC, including not only
4973 basic instruction set execution, but also details of execution unit
4974 performance and I/O hardware. See sim/ppc/README for more details.
4978 GDB now works with Solaris 2.5.
4980 * Windows 95/NT native
4982 GDB will now work as a native debugger on Windows 95 and Windows NT.
4983 To build it from source, you must use the "gnu-win32" environment,
4984 which uses a DLL to emulate enough of Unix to run the GNU tools.
4985 Further information, binaries, and sources are available at
4986 ftp.cygnus.com, under pub/gnu-win32.
4988 * dont-repeat command
4990 If a user-defined command includes the command `dont-repeat', then the
4991 command will not be repeated if the user just types return. This is
4992 useful if the command is time-consuming to run, so that accidental
4993 extra keystrokes don't run the same command many times.
4995 * Send break instead of ^C
4997 The standard remote protocol now includes an option to send a break
4998 rather than a ^C to the target in order to interrupt it. By default,
4999 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5001 * Remote protocol timeout
5003 The standard remote protocol includes a new variable `remotetimeout'
5004 that allows you to set the number of seconds before GDB gives up trying
5005 to read from the target. The default value is 2.
5007 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5009 By default GDB will automatically keep track of objects as they are
5010 loaded and unloaded by the dynamic linker. By using the command `set
5011 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5012 when shared library events occur, thus allowing you to set breakpoints
5013 in shared libraries which are explicitly loaded by the inferior.
5015 Note this feature does not work on hpux8. On hpux9 you must link
5016 /usr/lib/end.o into your program. This feature should work
5017 automatically on hpux10.
5019 * Irix 5.x hardware watchpoint support
5021 Irix 5 configurations now support the use of hardware watchpoints.
5023 * Mips protocol "SYN garbage limit"
5025 When debugging a Mips target using the `target mips' protocol, you
5026 may set the number of characters that GDB will ignore by setting
5027 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5028 every character. The default value is 1050.
5030 * Recording and replaying remote debug sessions
5032 If you set `remotelogfile' to the name of a file, gdb will write to it
5033 a recording of a remote debug session. This recording may then be
5034 replayed back to gdb using "gdbreplay". See gdbserver/README for
5035 details. This is useful when you have a problem with GDB while doing
5036 remote debugging; you can make a recording of the session and send it
5037 to someone else, who can then recreate the problem.
5039 * Speedups for remote debugging
5041 GDB includes speedups for downloading and stepping MIPS systems using
5042 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5043 and more efficient S-record downloading.
5045 * Memory use reductions and statistics collection
5047 GDB now uses less memory and reports statistics about memory usage.
5048 Try the `maint print statistics' command, for example.
5050 *** Changes in GDB-4.15:
5052 * Psymtabs for XCOFF
5054 The symbol reader for AIX GDB now uses partial symbol tables. This
5055 can greatly improve startup time, especially for large executables.
5057 * Remote targets use caching
5059 Remote targets now use a data cache to speed up communication with the
5060 remote side. The data cache could lead to incorrect results because
5061 it doesn't know about volatile variables, thus making it impossible to
5062 debug targets which use memory mapped I/O devices. `set remotecache
5063 off' turns the the data cache off.
5065 * Remote targets may have threads
5067 The standard remote protocol now includes support for multiple threads
5068 in the target system, using new protocol commands 'H' and 'T'. See
5069 gdb/remote.c for details.
5073 If GDB is configured with `--enable-netrom', then it will include
5074 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5075 acts as though it is a bank of ROM on the target board, but you can
5076 write into it over the network. GDB's support consists only of
5077 support for fast loading into the emulated ROM; to debug, you must use
5078 another protocol, such as standard remote protocol. The usual
5079 sequence is something like
5081 target nrom <netrom-hostname>
5083 target remote <netrom-hostname>:1235
5087 GDB now includes support for the Apple Macintosh, as a host only. It
5088 may be run as either an MPW tool or as a standalone application, and
5089 it can debug through the serial port. All the usual GDB commands are
5090 available, but to the target command, you must supply "serial" as the
5091 device type instead of "/dev/ttyXX". See mpw-README in the main
5092 directory for more information on how to build. The MPW configuration
5093 scripts */mpw-config.in support only a few targets, and only the
5094 mips-idt-ecoff target has been tested.
5098 GDB configuration now uses autoconf. This is not user-visible,
5099 but does simplify configuration and building.
5103 GDB now supports hpux10.
5105 *** Changes in GDB-4.14:
5107 * New native configurations
5109 x86 FreeBSD i[345]86-*-freebsd
5110 x86 NetBSD i[345]86-*-netbsd
5111 NS32k NetBSD ns32k-*-netbsd
5112 Sparc NetBSD sparc-*-netbsd
5116 A29K VxWorks a29k-*-vxworks
5117 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5118 CPU32 EST-300 emulator m68*-*-est*
5119 PowerPC ELF powerpc-*-elf
5122 * Alpha OSF/1 support for procfs
5124 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5125 possible to attach to running processes. As the mounting of the /proc
5126 filesystem is optional on the Alpha, GDB automatically determines
5127 the availability of /proc during startup. This can lead to problems
5128 if /proc is unmounted after GDB has been started.
5130 * Arguments to user-defined commands
5132 User commands may accept up to 10 arguments separated by whitespace.
5133 Arguments are accessed within the user command via $arg0..$arg9. A
5136 print $arg0 + $arg1 + $arg2
5138 To execute the command use:
5141 Defines the command "adder" which prints the sum of its three arguments.
5142 Note the arguments are text substitutions, so they may reference variables,
5143 use complex expressions, or even perform inferior function calls.
5145 * New `if' and `while' commands
5147 This makes it possible to write more sophisticated user-defined
5148 commands. Both commands take a single argument, which is the
5149 expression to evaluate, and must be followed by the commands to
5150 execute, one per line, if the expression is nonzero, the list being
5151 terminated by the word `end'. The `if' command list may include an
5152 `else' word, which causes the following commands to be executed only
5153 if the expression is zero.
5155 * Fortran source language mode
5157 GDB now includes partial support for Fortran 77. It will recognize
5158 Fortran programs and can evaluate a subset of Fortran expressions, but
5159 variables and functions may not be handled correctly. GDB will work
5160 with G77, but does not yet know much about symbols emitted by other
5163 * Better HPUX support
5165 Most debugging facilities now work on dynamic executables for HPPAs
5166 running hpux9 or later. You can attach to running dynamically linked
5167 processes, but by default the dynamic libraries will be read-only, so
5168 for instance you won't be able to put breakpoints in them. To change
5169 that behavior do the following before running the program:
5175 This will cause the libraries to be mapped private and read-write.
5176 To revert to the normal behavior, do this:
5182 You cannot set breakpoints or examine data in the library until after
5183 the library is loaded if the function/data symbols do not have
5186 GDB can now also read debug symbols produced by the HP C compiler on
5187 HPPAs (sorry, no C++, Fortran or 68k support).
5189 * Target byte order now dynamically selectable
5191 You can choose which byte order to use with a target system, via the
5192 commands "set endian big" and "set endian little", and you can see the
5193 current setting by using "show endian". You can also give the command
5194 "set endian auto", in which case GDB will use the byte order
5195 associated with the executable. Currently, only embedded MIPS
5196 configurations support dynamic selection of target byte order.
5198 * New DOS host serial code
5200 This version uses DPMI interrupts to handle buffered I/O, so you
5201 no longer need to run asynctsr when debugging boards connected to
5204 *** Changes in GDB-4.13:
5206 * New "complete" command
5208 This lists all the possible completions for the rest of the line, if it
5209 were to be given as a command itself. This is intended for use by emacs.
5211 * Trailing space optional in prompt
5213 "set prompt" no longer adds a space for you after the prompt you set. This
5214 allows you to set a prompt which ends in a space or one that does not.
5216 * Breakpoint hit counts
5218 "info break" now displays a count of the number of times the breakpoint
5219 has been hit. This is especially useful in conjunction with "ignore"; you
5220 can ignore a large number of breakpoint hits, look at the breakpoint info
5221 to see how many times the breakpoint was hit, then run again, ignoring one
5222 less than that number, and this will get you quickly to the last hit of
5225 * Ability to stop printing at NULL character
5227 "set print null-stop" will cause GDB to stop printing the characters of
5228 an array when the first NULL is encountered. This is useful when large
5229 arrays actually contain only short strings.
5231 * Shared library breakpoints
5233 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5234 breakpoints in shared libraries before the executable is run.
5236 * Hardware watchpoints
5238 There is a new hardware breakpoint for the watch command for sparclite
5239 targets. See gdb/sparclite/hw_breakpoint.note.
5241 Hardware watchpoints are also now supported under GNU/Linux.
5245 Annotations have been added. These are for use with graphical interfaces,
5246 and are still experimental. Currently only gdba.el uses these.
5248 * Improved Irix 5 support
5250 GDB now works properly with Irix 5.2.
5252 * Improved HPPA support
5254 GDB now works properly with the latest GCC and GAS.
5256 * New native configurations
5258 Sequent PTX4 i[34]86-sequent-ptx4
5259 HPPA running OSF/1 hppa*-*-osf*
5260 Atari TT running SVR4 m68*-*-sysv4*
5261 RS/6000 LynxOS rs6000-*-lynxos*
5265 OS/9000 i[34]86-*-os9k
5266 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5269 * Hitachi SH7000 and E7000-PC ICE support
5271 There is now support for communicating with the Hitachi E7000-PC ICE.
5272 This is available automatically when GDB is configured for the SH.
5276 As usual, a variety of small fixes and improvements, both generic
5277 and configuration-specific. See the ChangeLog for more detail.
5279 *** Changes in GDB-4.12:
5281 * Irix 5 is now supported
5285 GDB-4.12 on the HPPA has a number of changes which make it unable
5286 to debug the output from the currently released versions of GCC and
5287 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5288 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5289 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5292 *** Changes in GDB-4.11:
5294 * User visible changes:
5298 The "set remotedebug" option is now consistent between the mips remote
5299 target, remote targets using the gdb-specific protocol, UDI (AMD's
5300 debug protocol for the 29k) and the 88k bug monitor. It is now an
5301 integer specifying a debug level (normally 0 or 1, but 2 means more
5302 debugging info for the mips target).
5304 * DEC Alpha native support
5306 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5307 debug info, but GDB works fairly well with the DEC compiler and should
5308 work with a future GCC release. See the README file for a few
5309 Alpha-specific notes.
5311 * Preliminary thread implementation
5313 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5315 * LynxOS native and target support for 386
5317 This release has been hosted on LynxOS 2.2, and also can be configured
5318 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5321 * Improvements in C++ mangling/demangling.
5323 This release has much better g++ debugging, specifically in name
5324 mangling/demangling, virtual function calls, print virtual table,
5325 call methods, ...etc.
5327 *** Changes in GDB-4.10:
5329 * User visible changes:
5331 Remote debugging using the GDB-specific (`target remote') protocol now
5332 supports the `load' command. This is only useful if you have some
5333 other way of getting the stub to the target system, and you can put it
5334 somewhere in memory where it won't get clobbered by the download.
5336 Filename completion now works.
5338 When run under emacs mode, the "info line" command now causes the
5339 arrow to point to the line specified. Also, "info line" prints
5340 addresses in symbolic form (as well as hex).
5342 All vxworks based targets now support a user settable option, called
5343 vxworks-timeout. This option represents the number of seconds gdb
5344 should wait for responses to rpc's. You might want to use this if
5345 your vxworks target is, perhaps, a slow software simulator or happens
5346 to be on the far side of a thin network line.
5350 This release contains support for using a DEC alpha as a GDB host for
5351 cross debugging. Native alpha debugging is not supported yet.
5354 *** Changes in GDB-4.9:
5358 This is the first GDB release which is accompanied by a matching testsuite.
5359 The testsuite requires installation of dejagnu, which should be available
5360 via ftp from most sites that carry GNU software.
5364 'Cfront' style demangling has had its name changed to 'ARM' style, to
5365 emphasize that it was written from the specifications in the C++ Annotated
5366 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5367 disclaimers, it still generated too much confusion with users attempting to
5368 use gdb with AT&T cfront.
5372 GDB now uses a standard remote interface to a simulator library.
5373 So far, the library contains simulators for the Zilog Z8001/2, the
5374 Hitachi H8/300, H8/500 and Super-H.
5376 * New targets supported
5378 H8/300 simulator h8300-hitachi-hms or h8300hms
5379 H8/500 simulator h8500-hitachi-hms or h8500hms
5380 SH simulator sh-hitachi-hms or sh
5381 Z8000 simulator z8k-zilog-none or z8ksim
5382 IDT MIPS board over serial line mips-idt-ecoff
5384 Cross-debugging to GO32 targets is supported. It requires a custom
5385 version of the i386-stub.c module which is integrated with the
5386 GO32 memory extender.
5388 * New remote protocols
5390 MIPS remote debugging protocol.
5392 * New source languages supported
5394 This version includes preliminary support for Chill, a Pascal like language
5395 used by telecommunications companies. Chill support is also being integrated
5396 into the GNU compiler, but we don't know when it will be publically available.
5399 *** Changes in GDB-4.8:
5401 * HP Precision Architecture supported
5403 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5404 version of this support was available as a set of patches from the
5405 University of Utah. GDB does not support debugging of programs
5406 compiled with the HP compiler, because HP will not document their file
5407 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5408 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5410 Many problems in the preliminary version have been fixed.
5412 * Faster and better demangling
5414 We have improved template demangling and fixed numerous bugs in the GNU style
5415 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5416 character types (wchar_t) are now supported. Demangling of each symbol is now
5417 only done once, and is cached when the symbol table for a file is read in.
5418 This results in a small increase in memory usage for C programs, a moderate
5419 increase in memory usage for C++ programs, and a fantastic speedup in
5422 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5423 from the specifications in the Annotated Reference Manual, which AT&T's
5424 compiler does not actually implement.
5426 * G++ multiple inheritance compiler problem
5428 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5429 inheritance lattices was reworked to properly discover ambiguities. We
5430 recently found an example which causes this new algorithm to fail in a
5431 very subtle way, producing bad debug information for those classes.
5432 The file 'gcc.patch' (in this directory) can be applied to gcc to
5433 circumvent the problem. A future GCC release will contain a complete
5436 The previous G++ debug info problem (mentioned below for the gdb-4.7
5437 release) is fixed in gcc version 2.3.2.
5439 * Improved configure script
5441 The `configure' script will now attempt to guess your system type if
5442 you don't supply a host system type. The old scheme of supplying a
5443 host system triplet is preferable over using this. All the magic is
5444 done in the new `config.guess' script. Examine it for details.
5446 We have also brought our configure script much more in line with the FSF's
5447 version. It now supports the --with-xxx options. In particular,
5448 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5449 The resulting GDB will not be able to read arbitrary object file formats --
5450 only the format ``expected'' to be used on the configured target system.
5451 We hope to make this the default in a future release.
5453 * Documentation improvements
5455 There's new internal documentation on how to modify GDB, and how to
5456 produce clean changes to the code. We implore people to read it
5457 before submitting changes.
5459 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5460 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5461 `info' files are also provided. To build `info' files from scratch,
5462 you will need the latest `makeinfo' release, which will be available in
5463 a future texinfo-X.Y release.
5465 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5466 We're not sure exactly which versions have this problem, but it has
5467 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5468 or better. If that isn't possible, there is a patch in
5469 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5470 around this problem.
5474 GDB now supports array constants that can be used in expressions typed in by
5475 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5476 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5479 The new directory `gdb/sparclite' contains a program that demonstrates
5480 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5482 * New native hosts supported
5484 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5485 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5487 * New targets supported
5489 AMD 29k family via UDI a29k-amd-udi or udi29k
5491 * New file formats supported
5493 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5494 HPUX core files, and SCO 3.2v2 core files.
5498 Attaching to processes now works again; thanks for the many bug reports.
5500 We have also stomped on a bunch of core dumps caused by
5501 printf_filtered("%s") problems.
5503 We eliminated a copyright problem on the rpc and ptrace header files
5504 for VxWorks, which was discovered at the last minute during the 4.7
5505 release. You should now be able to build a VxWorks GDB.
5507 You can now interrupt gdb while an attached process is running. This
5508 will cause the attached process to stop, and give control back to GDB.
5510 We fixed problems caused by using too many file descriptors
5511 for reading symbols from object files and libraries. This was
5512 especially a problem for programs that used many (~100) shared
5515 The `step' command now only enters a subroutine if there is line number
5516 information for the subroutine. Otherwise it acts like the `next'
5517 command. Previously, `step' would enter subroutines if there was
5518 any debugging information about the routine. This avoids problems
5519 when using `cc -g1' on MIPS machines.
5521 * Internal improvements
5523 GDB's internal interfaces have been improved to make it easier to support
5524 debugging of multiple languages in the future.
5526 GDB now uses a common structure for symbol information internally.
5527 Minimal symbols (derived from linkage symbols in object files), partial
5528 symbols (from a quick scan of debug information), and full symbols
5529 contain a common subset of information, making it easier to write
5530 shared code that handles any of them.
5532 * New command line options
5534 We now accept --silent as an alias for --quiet.
5538 The memory-mapped-malloc library is now licensed under the GNU Library
5539 General Public License.
5541 *** Changes in GDB-4.7:
5543 * Host/native/target split
5545 GDB has had some major internal surgery to untangle the support for
5546 hosts and remote targets. Now, when you configure GDB for a remote
5547 target, it will no longer load in all of the support for debugging
5548 local programs on the host. When fully completed and tested, this will
5549 ensure that arbitrary host/target combinations are possible.
5551 The primary conceptual shift is to separate the non-portable code in
5552 GDB into three categories. Host specific code is required any time GDB
5553 is compiled on that host, regardless of the target. Target specific
5554 code relates to the peculiarities of the target, but can be compiled on
5555 any host. Native specific code is everything else: it can only be
5556 built when the host and target are the same system. Child process
5557 handling and core file support are two common `native' examples.
5559 GDB's use of /proc for controlling Unix child processes is now cleaner.
5560 It has been split out into a single module under the `target_ops' vector,
5561 plus two native-dependent functions for each system that uses /proc.
5563 * New hosts supported
5565 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5566 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5567 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5569 * New targets supported
5571 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5572 68030 and CPU32 m68030-*-*, m68332-*-*
5574 * New native hosts supported
5576 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5577 (386bsd is not well tested yet)
5578 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5580 * New file formats supported
5582 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5583 supports reading of `a.out.adobe' object files, which are an a.out
5584 format extended with minimal information about multiple sections.
5588 `show copying' is the same as the old `info copying'.
5589 `show warranty' is the same as `info warrantee'.
5590 These were renamed for consistency. The old commands continue to work.
5592 `info handle' is a new alias for `info signals'.
5594 You can now define pre-command hooks, which attach arbitrary command
5595 scripts to any command. The commands in the hook will be executed
5596 prior to the user's command. You can also create a hook which will be
5597 executed whenever the program stops. See gdb.texinfo.
5601 We now deal with Cfront style name mangling, and can even extract type
5602 info from mangled symbols. GDB can automatically figure out which
5603 symbol mangling style your C++ compiler uses.
5605 Calling of methods and virtual functions has been improved as well.
5609 The crash that occured when debugging Sun Ansi-C compiled binaries is
5610 fixed. This was due to mishandling of the extra N_SO stabs output
5613 We also finally got Ultrix 4.2 running in house, and fixed core file
5614 support, with help from a dozen people on the net.
5616 John M. Farrell discovered that the reason that single-stepping was so
5617 slow on all of the Mips based platforms (primarily SGI and DEC) was
5618 that we were trying to demangle and lookup a symbol used for internal
5619 purposes on every instruction that was being stepped through. Changing
5620 the name of that symbol so that it couldn't be mistaken for a C++
5621 mangled symbol sped things up a great deal.
5623 Rich Pixley sped up symbol lookups in general by getting much smarter
5624 about when C++ symbol mangling is necessary. This should make symbol
5625 completion (TAB on the command line) much faster. It's not as fast as
5626 we'd like, but it's significantly faster than gdb-4.6.
5630 A new user controllable variable 'call_scratch_address' can
5631 specify the location of a scratch area to be used when GDB
5632 calls a function in the target. This is necessary because the
5633 usual method of putting the scratch area on the stack does not work
5634 in systems that have separate instruction and data spaces.
5636 We integrated changes to support the 29k UDI (Universal Debugger
5637 Interface), but discovered at the last minute that we didn't have all
5638 of the appropriate copyright paperwork. We are working with AMD to
5639 resolve this, and hope to have it available soon.
5643 We have sped up the remote serial line protocol, especially for targets
5644 with lots of registers. It now supports a new `expedited status' ('T')
5645 message which can be used in place of the existing 'S' status message.
5646 This allows the remote stub to send only the registers that GDB
5647 needs to make a quick decision about single-stepping or conditional
5648 breakpoints, eliminating the need to fetch the entire register set for
5649 each instruction being stepped through.
5651 The GDB remote serial protocol now implements a write-through cache for
5652 registers, only re-reading the registers if the target has run.
5654 There is also a new remote serial stub for SPARC processors. You can
5655 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5656 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5657 processor with a serial port.
5661 Configure.in files have become much easier to read and modify. A new
5662 `table driven' format makes it more obvious what configurations are
5663 supported, and what files each one uses.
5667 There is a new opcodes library which will eventually contain all of the
5668 disassembly routines and opcode tables. At present, it only contains
5669 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5670 disassembler (binutils/objdump) to share these routines.
5672 The libiberty library is now copylefted under the GNU Library General
5673 Public License. This allows more liberal use, and was done so libg++
5674 can use it. This makes no difference to GDB, since the Library License
5675 grants all the rights from the General Public License.
5679 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5680 reference to the stabs symbol info used by the debugger. It is (as far
5681 as we know) the only published document on this fascinating topic. We
5682 encourage you to read it, compare it to the stabs information on your
5683 system, and send improvements on the document in general (to
5684 bug-gdb@prep.ai.mit.edu).
5686 And, of course, many bugs have been fixed.
5689 *** Changes in GDB-4.6:
5691 * Better support for C++ function names
5693 GDB now accepts as input the "demangled form" of C++ overloaded function
5694 names and member function names, and can do command completion on such names
5695 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5696 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5697 Make use of command completion, it is your friend.
5699 GDB also now accepts a variety of C++ mangled symbol formats. They are
5700 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5701 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5702 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5703 for the list of formats.
5705 * G++ symbol mangling problem
5707 Recent versions of gcc have a bug in how they emit debugging information for
5708 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5709 directory) can be applied to gcc to fix the problem. Alternatively, if you
5710 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5711 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5712 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5715 * New 'maintenance' command
5717 All of the commands related to hacking GDB internals have been moved out of
5718 the main command set, and now live behind the 'maintenance' command. This
5719 can also be abbreviated as 'mt'. The following changes were made:
5721 dump-me -> maintenance dump-me
5722 info all-breakpoints -> maintenance info breakpoints
5723 printmsyms -> maintenance print msyms
5724 printobjfiles -> maintenance print objfiles
5725 printpsyms -> maintenance print psymbols
5726 printsyms -> maintenance print symbols
5728 The following commands are new:
5730 maintenance demangle Call internal GDB demangler routine to
5731 demangle a C++ link name and prints the result.
5732 maintenance print type Print a type chain for a given symbol
5734 * Change to .gdbinit file processing
5736 We now read the $HOME/.gdbinit file before processing the argv arguments
5737 (e.g. reading symbol files or core files). This allows global parameters to
5738 be set, which will apply during the symbol reading. The ./.gdbinit is still
5739 read after argv processing.
5741 * New hosts supported
5743 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5745 GNU/Linux support i386-unknown-linux or linux
5747 We are also including code to support the HP/PA running BSD and HPUX. This
5748 is almost guaranteed not to work, as we didn't have time to test or build it
5749 for this release. We are including it so that the more adventurous (or
5750 masochistic) of you can play with it. We also had major problems with the
5751 fact that the compiler that we got from HP doesn't support the -g option.
5754 * New targets supported
5756 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5758 * More smarts about finding #include files
5760 GDB now remembers the compilation directory for all include files, and for
5761 all files from which C is generated (like yacc and lex sources). This
5762 greatly improves GDB's ability to find yacc/lex sources, and include files,
5763 especially if you are debugging your program from a directory different from
5764 the one that contains your sources.
5766 We also fixed a bug which caused difficulty with listing and setting
5767 breakpoints in include files which contain C code. (In the past, you had to
5768 try twice in order to list an include file that you hadn't looked at before.)
5770 * Interesting infernals change
5772 GDB now deals with arbitrary numbers of sections, where the symbols for each
5773 section must be relocated relative to that section's landing place in the
5774 target's address space. This work was needed to support ELF with embedded
5775 stabs used by Solaris-2.0.
5777 * Bug fixes (of course!)
5779 There have been loads of fixes for the following things:
5780 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5781 i960, stabs, DOS(GO32), procfs, etc...
5783 See the ChangeLog for details.
5785 *** Changes in GDB-4.5:
5787 * New machines supported (host and target)
5789 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5791 SGI Irix-4.x mips-sgi-irix4 or iris4
5793 * New malloc package
5795 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5796 Mmalloc is capable of handling mutiple heaps of memory. It is also
5797 capable of saving a heap to a file, and then mapping it back in later.
5798 This can be used to greatly speedup the startup of GDB by using a
5799 pre-parsed symbol table which lives in a mmalloc managed heap. For
5800 more details, please read mmalloc/mmalloc.texi.
5804 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5805 'help info proc' for details.
5807 * MIPS ecoff symbol table format
5809 The code that reads MIPS symbol table format is now supported on all hosts.
5810 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5813 * File name changes for MS-DOS
5815 Many files in the config directories have been renamed to make it easier to
5816 support GDB on MS-DOSe systems (which have very restrictive file name
5817 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5818 environment) is close to working but has some remaining problems. Note
5819 that debugging of DOS programs is not supported, due to limitations
5820 in the ``operating system'', but it can be used to host cross-debugging.
5822 * Cross byte order fixes
5824 Many fixes have been made to support cross debugging of Sparc and MIPS
5825 targets from hosts whose byte order differs.
5827 * New -mapped and -readnow options
5829 If memory-mapped files are available on your system through the 'mmap'
5830 system call, you can use the -mapped option on the `file' or
5831 `symbol-file' commands to cause GDB to write the symbols from your
5832 program into a reusable file. If the program you are debugging is
5833 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5834 Future GDB debugging sessions will notice the presence of this file,
5835 and will quickly map in symbol information from it, rather than reading
5836 the symbol table from the executable program. Using the '-mapped'
5837 option in a GDB `file' or `symbol-file' command has the same effect as
5838 starting GDB with the '-mapped' command-line option.
5840 You can cause GDB to read the entire symbol table immediately by using
5841 the '-readnow' option with any of the commands that load symbol table
5842 information (or on the GDB command line). This makes the command
5843 slower, but makes future operations faster.
5845 The -mapped and -readnow options are typically combined in order to
5846 build a `fred.syms' file that contains complete symbol information.
5847 A simple GDB invocation to do nothing but build a `.syms' file for future
5850 gdb -batch -nx -mapped -readnow programname
5852 The `.syms' file is specific to the host machine on which GDB is run.
5853 It holds an exact image of GDB's internal symbol table. It cannot be
5854 shared across multiple host platforms.
5856 * longjmp() handling
5858 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5859 siglongjmp() without losing control. This feature has not yet been ported to
5860 all systems. It currently works on many 386 platforms, all MIPS-based
5861 platforms (SGI, DECstation, etc), and Sun3/4.
5865 Preliminary work has been put in to support the new Solaris OS from Sun. At
5866 this time, it can control and debug processes, but it is not capable of
5871 As always, many many bug fixes. The major areas were with g++, and mipsread.
5872 People using the MIPS-based platforms should experience fewer mysterious
5873 crashes and trashed symbol tables.
5875 *** Changes in GDB-4.4:
5877 * New machines supported (host and target)
5879 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5881 BSD Reno on Vax vax-dec-bsd
5882 Ultrix on Vax vax-dec-ultrix
5884 * New machines supported (target)
5886 AMD 29000 embedded, using EBMON a29k-none-none
5890 GDB continues to improve its handling of C++. `References' work better.
5891 The demangler has also been improved, and now deals with symbols mangled as
5892 per the Annotated C++ Reference Guide.
5894 GDB also now handles `stabs' symbol information embedded in MIPS
5895 `ecoff' symbol tables. Since the ecoff format was not easily
5896 extensible to handle new languages such as C++, this appeared to be a
5897 good way to put C++ debugging info into MIPS binaries. This option
5898 will be supported in the GNU C compiler, version 2, when it is
5901 * New features for SVR4
5903 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5904 shared libraries. Debugging dynamically linked programs should present
5905 only minor differences from debugging statically linked programs.
5907 The `info proc' command will print out information about any process
5908 on an SVR4 system (including the one you are debugging). At the moment,
5909 it prints the address mappings of the process.
5911 If you bring up GDB on another SVR4 system, please send mail to
5912 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5914 * Better dynamic linking support in SunOS
5916 Reading symbols from shared libraries which contain debugging symbols
5917 now works properly. However, there remain issues such as automatic
5918 skipping of `transfer vector' code during function calls, which
5919 make it harder to debug code in a shared library, than to debug the
5920 same code linked statically.
5924 GDB is now using the latest `getopt' routines from the FSF. This
5925 version accepts the -- prefix for options with long names. GDB will
5926 continue to accept the old forms (-option and +option) as well.
5927 Various single letter abbreviations for options have been explicity
5928 added to the option table so that they won't get overshadowed in the
5929 future by other options that begin with the same letter.
5933 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5934 Many assorted bugs have been handled. Many more remain to be handled.
5935 See the various ChangeLog files (primarily in gdb and bfd) for details.
5938 *** Changes in GDB-4.3:
5940 * New machines supported (host and target)
5942 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5943 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5944 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5946 * Almost SCO Unix support
5948 We had hoped to support:
5949 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5950 (except for core file support), but we discovered very late in the release
5951 that it has problems with process groups that render gdb unusable. Sorry
5952 about that. I encourage people to fix it and post the fixes.
5954 * Preliminary ELF and DWARF support
5956 GDB can read ELF object files on System V Release 4, and can handle
5957 debugging records for C, in DWARF format, in ELF files. This support
5958 is preliminary. If you bring up GDB on another SVR4 system, please
5959 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5964 GDB now uses the latest `readline' library. One user-visible change
5965 is that two tabs will list possible command completions, which previously
5966 required typing M-? (meta-question mark, or ESC ?).
5970 The `stepi' bug that many of you noticed has been squashed.
5971 Many bugs in C++ have been handled. Many more remain to be handled.
5972 See the various ChangeLog files (primarily in gdb and bfd) for details.
5974 * State of the MIPS world (in case you wondered):
5976 GDB can understand the symbol tables emitted by the compilers
5977 supplied by most vendors of MIPS-based machines, including DEC. These
5978 symbol tables are in a format that essentially nobody else uses.
5980 Some versions of gcc come with an assembler post-processor called
5981 mips-tfile. This program is required if you want to do source-level
5982 debugging of gcc-compiled programs. I believe FSF does not ship
5983 mips-tfile with gcc version 1, but it will eventually come with gcc
5986 Debugging of g++ output remains a problem. g++ version 1.xx does not
5987 really support it at all. (If you're lucky, you should be able to get
5988 line numbers and stack traces to work, but no parameters or local
5989 variables.) With some work it should be possible to improve the
5992 When gcc version 2 is released, you will have somewhat better luck.
5993 However, even then you will get confusing results for inheritance and
5996 We will eventually provide full debugging of g++ output on
5997 DECstations. This will probably involve some kind of stabs-in-ecoff
5998 encapulation, but the details have not been worked out yet.
6001 *** Changes in GDB-4.2:
6003 * Improved configuration
6005 Only one copy of `configure' exists now, and it is not self-modifying.
6006 Porting BFD is simpler.
6010 The `step' and `next' commands now only stop at the first instruction
6011 of a source line. This prevents the multiple stops that used to occur
6012 in switch statements, for-loops, etc. `Step' continues to stop if a
6013 function that has debugging information is called within the line.
6017 Lots of small bugs fixed. More remain.
6019 * New host supported (not target)
6021 Intel 386 PC clone running Mach i386-none-mach
6024 *** Changes in GDB-4.1:
6026 * Multiple source language support
6028 GDB now has internal scaffolding to handle several source languages.
6029 It determines the type of each source file from its filename extension,
6030 and will switch expression parsing and number formatting to match the
6031 language of the function in the currently selected stack frame.
6032 You can also specifically set the language to be used, with
6033 `set language c' or `set language modula-2'.
6037 GDB now has preliminary support for the GNU Modula-2 compiler,
6038 currently under development at the State University of New York at
6039 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6040 continue through the fall of 1991 and into 1992.
6042 Other Modula-2 compilers are currently not supported, and attempting to
6043 debug programs compiled with them will likely result in an error as the
6044 symbol table is read. Feel free to work on it, though!
6046 There are hooks in GDB for strict type checking and range checking,
6047 in the `Modula-2 philosophy', but they do not currently work.
6051 GDB can now write to executable and core files (e.g. patch
6052 a variable's value). You must turn this switch on, specify
6053 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6054 by assigning a new value to a variable. Modifications take
6057 * Automatic SunOS shared library reading
6059 When you run your program, GDB automatically determines where its
6060 shared libraries (if any) have been loaded, and reads their symbols.
6061 The `share' command is no longer needed. This also works when
6062 examining core files.
6066 You can specify the number of lines that the `list' command shows.
6069 * New machines supported (host and target)
6071 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6072 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6073 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6075 * New hosts supported (not targets)
6077 IBM RT/PC: romp-ibm-aix or rtpc
6079 * New targets supported (not hosts)
6081 AMD 29000 embedded with COFF a29k-none-coff
6082 AMD 29000 embedded with a.out a29k-none-aout
6083 Ultracomputer remote kernel debug a29k-nyu-kern
6085 * New remote interfaces
6091 *** Changes in GDB-4.0:
6095 Wide output is wrapped at good places to make the output more readable.
6097 Gdb now supports cross-debugging from a host machine of one type to a
6098 target machine of another type. Communication with the target system
6099 is over serial lines. The ``target'' command handles connecting to the
6100 remote system; the ``load'' command will download a program into the
6101 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6102 also supports debugging of realtime processes running under VxWorks,
6103 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6104 stub on the target system.
6106 New CPUs supported include the AMD 29000 and Intel 960.
6108 GDB now reads object files and symbol tables via a ``binary file''
6109 library, which allows a single copy of GDB to debug programs of multiple
6110 object file types such as a.out and coff.
6112 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6113 refcard.dvi and refcard.ps are available to format it).
6116 * Control-Variable user interface simplified
6118 All variables that control the operation of the debugger can be set
6119 by the ``set'' command, and displayed by the ``show'' command.
6121 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6122 ``Show prompt'' produces the response:
6123 Gdb's prompt is new-gdb=>.
6125 What follows are the NEW set commands. The command ``help set'' will
6126 print a complete list of old and new set commands. ``help set FOO''
6127 will give a longer description of the variable FOO. ``show'' will show
6128 all of the variable descriptions and their current settings.
6130 confirm on/off: Enables warning questions for operations that are
6131 hard to recover from, e.g. rerunning the program while
6132 it is already running. Default is ON.
6134 editing on/off: Enables EMACS style command line editing
6135 of input. Previous lines can be recalled with
6136 control-P, the current line can be edited with control-B,
6137 you can search for commands with control-R, etc.
6140 history filename NAME: NAME is where the gdb command history
6141 will be stored. The default is .gdb_history,
6142 or the value of the environment variable
6145 history size N: The size, in commands, of the command history. The
6146 default is 256, or the value of the environment variable
6149 history save on/off: If this value is set to ON, the history file will
6150 be saved after exiting gdb. If set to OFF, the
6151 file will not be saved. The default is OFF.
6153 history expansion on/off: If this value is set to ON, then csh-like
6154 history expansion will be performed on
6155 command line input. The default is OFF.
6157 radix N: Sets the default radix for input and output. It can be set
6158 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6159 in the current radix, so "set radix 10" is always a no-op.
6161 height N: This integer value is the number of lines on a page. Default
6162 is 24, the current `stty rows'' setting, or the ``li#''
6163 setting from the termcap entry matching the environment
6166 width N: This integer value is the number of characters on a line.
6167 Default is 80, the current `stty cols'' setting, or the ``co#''
6168 setting from the termcap entry matching the environment
6171 Note: ``set screensize'' is obsolete. Use ``set height'' and
6172 ``set width'' instead.
6174 print address on/off: Print memory addresses in various command displays,
6175 such as stack traces and structure values. Gdb looks
6176 more ``symbolic'' if you turn this off; it looks more
6177 ``machine level'' with it on. Default is ON.
6179 print array on/off: Prettyprint arrays. New convenient format! Default
6182 print demangle on/off: Print C++ symbols in "source" form if on,
6185 print asm-demangle on/off: Same, for assembler level printouts
6188 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6191 * Support for Epoch Environment.
6193 The epoch environment is a version of Emacs v18 with windowing. One
6194 new command, ``inspect'', is identical to ``print'', except that if you
6195 are running in the epoch environment, the value is printed in its own
6199 * Support for Shared Libraries
6201 GDB can now debug programs and core files that use SunOS shared libraries.
6202 Symbols from a shared library cannot be referenced
6203 before the shared library has been linked with the program (this
6204 happens after you type ``run'' and before the function main() is entered).
6205 At any time after this linking (including when examining core files
6206 from dynamically linked programs), gdb reads the symbols from each
6207 shared library when you type the ``sharedlibrary'' command.
6208 It can be abbreviated ``share''.
6210 sharedlibrary REGEXP: Load shared object library symbols for files
6211 matching a unix regular expression. No argument
6212 indicates to load symbols for all shared libraries.
6214 info sharedlibrary: Status of loaded shared libraries.
6219 A watchpoint stops execution of a program whenever the value of an
6220 expression changes. Checking for this slows down execution
6221 tremendously whenever you are in the scope of the expression, but is
6222 quite useful for catching tough ``bit-spreader'' or pointer misuse
6223 problems. Some machines such as the 386 have hardware for doing this
6224 more quickly, and future versions of gdb will use this hardware.
6226 watch EXP: Set a watchpoint (breakpoint) for an expression.
6228 info watchpoints: Information about your watchpoints.
6230 delete N: Deletes watchpoint number N (same as breakpoints).
6231 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6232 enable N: Re-enables watchpoint number N (same as breakpoints).
6235 * C++ multiple inheritance
6237 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6240 * C++ exception handling
6242 Gdb now supports limited C++ exception handling. Besides the existing
6243 ability to breakpoint on an exception handler, gdb can breakpoint on
6244 the raising of an exception (before the stack is peeled back to the
6247 catch FOO: If there is a FOO exception handler in the dynamic scope,
6248 set a breakpoint to catch exceptions which may be raised there.
6249 Multiple exceptions (``catch foo bar baz'') may be caught.
6251 info catch: Lists all exceptions which may be caught in the
6252 current stack frame.
6255 * Minor command changes
6257 The command ``call func (arg, arg, ...)'' now acts like the print
6258 command, except it does not print or save a value if the function's result
6259 is void. This is similar to dbx usage.
6261 The ``up'' and ``down'' commands now always print the frame they end up
6262 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6263 frames without printing.
6265 * New directory command
6267 'dir' now adds directories to the FRONT of the source search path.
6268 The path starts off empty. Source files that contain debug information
6269 about the directory in which they were compiled can be found even
6270 with an empty path; Sun CC and GCC include this information. If GDB can't
6271 find your source file in the current directory, type "dir .".
6273 * Configuring GDB for compilation
6275 For normal use, type ``./configure host''. See README or gdb.texinfo
6278 GDB now handles cross debugging. If you are remotely debugging between
6279 two different machines, type ``./configure host -target=targ''.
6280 Host is the machine where GDB will run; targ is the machine
6281 where the program that you are debugging will run.