1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.9
6 * The "info os" command on GNU/Linux can now display information on
8 "info os cpus" Listing of all cpus/cores on the system
10 * GDB has two new commands: "set serial parity odd|even|none" and
11 "show serial parity". These allows to set or show parity for the
14 * The "info source" command now displays the producer string if it was
15 present in the debug info. This typically includes the compiler version
16 and may include things like its command line arguments.
20 ** gdb.Objfile objects have a new attribute "username",
21 which is the name of the objfile as specified by the user,
22 without, for example, resolving symlinks.
26 maint print symbol-cache
27 Print the contents of the symbol cache.
29 maint print symbol-cache-statistics
30 Print statistics of symbol cache usage.
32 maint flush-symbol-cache
33 Flush the contents of the symbol cache.
37 Start branch trace recording using Branch Trace Store (BTS) format.
43 Set the maximum number of candidates to be considered during
44 completion. The default value is 200. This limit allows GDB
45 to avoid generating large completion lists, the computation of
46 which can cause the debugger to become temporarily unresponsive.
48 maint set symbol-cache-size
49 maint show symbol-cache-size
50 Control the size of the symbol cache.
52 set|show record btrace bts buffer-size
53 Set and show the size of the ring buffer used for branch tracing in
55 The obtained size may differ from the requested size. Use "info
56 record" to see the obtained buffer size.
58 * The command 'thread apply all' can now support new option '-ascending'
59 to call its specified command for all threads in ascending order.
61 * Python/Guile scripting
63 ** GDB now supports auto-loading of Python/Guile scripts contained in the
64 special section named `.debug_gdb_scripts'.
68 qXfer:btrace-conf:read
69 Return the branch trace configuration for the current thread.
72 Set the requested ring buffer size for branch tracing in BTS format.
75 Indicates a memory breakpoint instruction was executed, irrespective
76 of whether it was GDB that planted the breakpoint or the breakpoint
77 is hardcoded in the program. This is required for correct non-stop
81 Indicates the target stopped for a hardware breakpoint. This is
82 required for correct non-stop mode operation.
85 Return information about files on the remote system.
87 * The info record command now shows the recording format and the
88 branch tracing configuration for the current thread when using
89 the btrace record target.
90 For the BTS format, it shows the ring buffer size.
92 * GDB now has support for DTrace USDT (Userland Static Defined
93 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
95 * GDB now supports access to vector registers on S/390 GNU/Linux
98 * Removed targets and native configurations
100 HP/PA running HP-UX hppa*-*-hpux*
101 Itanium running HP-UX ia64-*-hpux*
103 *** Changes in GDB 7.9
105 * GDB now supports hardware watchpoints on x86 GNU Hurd.
109 ** You can now access frame registers from Python scripts.
110 ** New attribute 'producer' for gdb.Symtab objects.
111 ** gdb.Objfile objects have a new attribute "progspace",
112 which is the gdb.Progspace object of the containing program space.
113 ** gdb.Objfile objects have a new attribute "owner".
114 ** gdb.Objfile objects have a new attribute "build_id",
115 which is the build ID generated when the file was built.
116 ** gdb.Objfile objects have a new method "add_separate_debug_file".
117 ** A new event "gdb.clear_objfiles" has been added, triggered when
118 selecting a new file to debug.
119 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
120 ** New function gdb.lookup_objfile.
122 New events which are triggered when GDB modifies the state of the
125 ** gdb.events.inferior_call_pre: Function call is about to be made.
126 ** gdb.events.inferior_call_post: Function call has just been made.
127 ** gdb.events.memory_changed: A memory location has been altered.
128 ** gdb.events.register_changed: A register has been altered.
130 * New Python-based convenience functions:
132 ** $_caller_is(name [, number_of_frames])
133 ** $_caller_matches(regexp [, number_of_frames])
134 ** $_any_caller_is(name [, number_of_frames])
135 ** $_any_caller_matches(regexp [, number_of_frames])
137 * GDB now supports the compilation and injection of source code into
138 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
139 to compile the source code to object code, and if successful, inject
140 and execute that code within the current context of the inferior.
141 Currently the C language is supported. The commands used to
142 interface with this new feature are:
144 compile code [-raw|-r] [--] [source code]
145 compile file [-raw|-r] filename
149 demangle [-l language] [--] name
150 Demangle "name" in the specified language, or the current language
151 if elided. This command is renamed from the "maint demangle" command.
152 The latter is kept as a no-op to avoid "maint demangle" being interpreted
153 as "maint demangler-warning".
155 queue-signal signal-name-or-number
156 Queue a signal to be delivered to the thread when it is resumed.
158 add-auto-load-scripts-directory directory
159 Add entries to the list of directories from which to load auto-loaded
162 maint print user-registers
163 List all currently available "user" registers.
165 compile code [-r|-raw] [--] [source code]
166 Compile, inject, and execute in the inferior the executable object
167 code produced by compiling the provided source code.
169 compile file [-r|-raw] filename
170 Compile and inject into the inferior the executable object code
171 produced by compiling the source code stored in the filename
174 * On resume, GDB now always passes the signal the program had stopped
175 for to the thread the signal was sent to, even if the user changed
176 threads before resuming. Previously GDB would often (but not
177 always) deliver the signal to the thread that happens to be current
180 * Conversely, the "signal" command now consistently delivers the
181 requested signal to the current thread. GDB now asks for
182 confirmation if the program had stopped for a signal and the user
183 switched threads meanwhile.
185 * "breakpoint always-inserted" modes "off" and "auto" merged.
187 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
188 won't remove breakpoints from the target until all threads stop,
189 even in non-stop mode. The "auto" mode has been removed, and "off"
190 is now the default mode.
194 set debug symbol-lookup
195 show debug symbol-lookup
196 Control display of debugging info regarding symbol lookup.
200 ** The -list-thread-groups command outputs an exit-code field for
201 inferiors that have exited.
205 MIPS SDE mips*-sde*-elf*
209 Support for these obsolete configurations has been removed.
211 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
212 SGI Irix-5.x mips-*-irix5*
213 SGI Irix-6.x mips-*-irix6*
214 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
215 VAX running Ultrix vax-*-ultrix*
217 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
218 and "assf"), have been removed. Use the "sharedlibrary" command, or
219 its alias "share", instead.
221 *** Changes in GDB 7.8
223 * New command line options
226 This is an alias for the --data-directory option.
228 * GDB supports printing and modifying of variable length automatic arrays
229 as specified in ISO C99.
231 * The ARM simulator now supports instruction level tracing
232 with or without disassembly.
236 GDB now has support for scripting using Guile. Whether this is
237 available is determined at configure time.
238 Guile version 2.0 or greater is required.
239 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
241 * New commands (for set/show, see "New options" below)
245 Invoke CODE by passing it to the Guile interpreter.
249 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
251 info auto-load guile-scripts [regexp]
252 Print the list of automatically loaded Guile scripts.
254 * The source command is now capable of sourcing Guile scripts.
255 This feature is dependent on the debugger being built with Guile support.
259 set print symbol-loading (off|brief|full)
260 show print symbol-loading
261 Control whether to print informational messages when loading symbol
262 information for a file. The default is "full", but when debugging
263 programs with large numbers of shared libraries the amount of output
266 set guile print-stack (none|message|full)
267 show guile print-stack
268 Show a stack trace when an error is encountered in a Guile script.
270 set auto-load guile-scripts (on|off)
271 show auto-load guile-scripts
272 Control auto-loading of Guile script files.
274 maint ada set ignore-descriptive-types (on|off)
275 maint ada show ignore-descriptive-types
276 Control whether the debugger should ignore descriptive types in Ada
277 programs. The default is not to ignore the descriptive types. See
278 the user manual for more details on descriptive types and the intended
279 usage of this option.
281 set auto-connect-native-target
283 Control whether GDB is allowed to automatically connect to the
284 native target for the run, attach, etc. commands when not connected
285 to any target yet. See also "target native" below.
287 set record btrace replay-memory-access (read-only|read-write)
288 show record btrace replay-memory-access
289 Control what memory accesses are allowed during replay.
291 maint set target-async (on|off)
292 maint show target-async
293 This controls whether GDB targets operate in synchronous or
294 asynchronous mode. Normally the default is asynchronous, if it is
295 available; but this can be changed to more easily debug problems
296 occurring only in synchronous mode.
298 set mi-async (on|off)
300 Control whether MI asynchronous mode is preferred. This supersedes
301 "set target-async" of previous GDB versions.
303 * "set target-async" is deprecated as a CLI option and is now an alias
304 for "set mi-async" (only puts MI into async mode).
306 * Background execution commands (e.g., "c&", "s&", etc.) are now
307 possible ``out of the box'' if the target supports them. Previously
308 the user would need to explicitly enable the possibility with the
309 "set target-async on" command.
311 * New features in the GDB remote stub, GDBserver
313 ** New option --debug-format=option1[,option2,...] allows one to add
314 additional text to each output. At present only timestamps
315 are supported: --debug-format=timestamps.
316 Timestamps can also be turned on with the
317 "monitor set debug-format timestamps" command from GDB.
319 * The 'record instruction-history' command now starts counting instructions
320 at one. This also affects the instruction ranges reported by the
321 'record function-call-history' command when given the /i modifier.
323 * The command 'record function-call-history' supports a new modifier '/c' to
324 indent the function names based on their call stack depth.
325 The fields for the '/i' and '/l' modifier have been reordered.
326 The source line range is now prefixed with 'at'.
327 The instruction range is now prefixed with 'inst'.
328 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
329 "record instruction-history" and "list" commands.
331 * The ranges given as arguments to the 'record function-call-history' and
332 'record instruction-history' commands are now inclusive.
334 * The btrace record target now supports the 'record goto' command.
335 For locations inside the execution trace, the back trace is computed
336 based on the information stored in the execution trace.
338 * The btrace record target supports limited reverse execution and replay.
339 The target does not record data and therefore does not allow reading
342 * The "catch syscall" command now works on s390*-linux* targets.
344 * The "compare-sections" command is no longer specific to target
345 remote. It now works with all targets.
347 * All native targets are now consistently called "native".
348 Consequently, the "target child", "target GNU", "target djgpp",
349 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
350 commands have been replaced with "target native". The QNX/NTO port
351 leaves the "procfs" target in place and adds a "native" target for
352 consistency with other ports. The impact on users should be minimal
353 as these commands previously either throwed an error, or were
354 no-ops. The target's name is visible in the output of the following
355 commands: "help target", "info target", "info files", "maint print
358 * The "target native" command now connects to the native target. This
359 can be used to launch native programs even when "set
360 auto-connect-native-target" is set to off.
362 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.
364 * Support for Intel(R) AVX-512 registers on GNU/Linux.
365 Support displaying and modifying Intel(R) AVX-512 registers
366 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
370 qXfer:btrace:read's annex
371 The qXfer:btrace:read packet supports a new annex 'delta' to read
372 branch trace incrementally.
376 ** Valid Python operations on gdb.Value objects representing
377 structs/classes invoke the corresponding overloaded operators if
379 ** New `Xmethods' feature in the Python API. Xmethods are
380 additional methods or replacements for existing methods of a C++
381 class. This feature is useful for those cases where a method
382 defined in C++ source code could be inlined or optimized out by
383 the compiler, making it unavailable to GDB.
386 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
388 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
389 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
390 its alias "share", instead.
392 * The commands "set remotebaud" and "show remotebaud" are no longer
393 supported. Use "set serial baud" and "show serial baud" (respectively)
398 ** A new option "-gdb-set mi-async" replaces "-gdb-set
399 target-async". The latter is left as a deprecated alias of the
400 former for backward compatibility. If the target supports it,
401 CLI background execution commands are now always possible by
402 default, independently of whether the frontend stated a
403 preference for asynchronous execution with "-gdb-set mi-async".
404 Previously "-gdb-set target-async off" affected both MI execution
405 commands and CLI execution commands.
407 *** Changes in GDB 7.7
409 * Improved support for process record-replay and reverse debugging on
410 arm*-linux* targets. Support for thumb32 and syscall instruction
411 recording has been added.
413 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
415 * GDB now supports Fission DWP file format version 2.
416 http://gcc.gnu.org/wiki/DebugFission
418 * New convenience function "$_isvoid", to check whether an expression
419 is void. A void expression is an expression where the type of the
420 result is "void". For example, some convenience variables may be
421 "void" when evaluated (e.g., "$_exitcode" before the execution of
422 the program being debugged; or an undefined convenience variable).
423 Another example, when calling a function whose return type is
426 * The "maintenance print objfiles" command now takes an optional regexp.
428 * The "catch syscall" command now works on arm*-linux* targets.
430 * GDB now consistently shows "<not saved>" when printing values of
431 registers the debug info indicates have not been saved in the frame
432 and there's nowhere to retrieve them from
433 (callee-saved/call-clobbered registers):
438 (gdb) info registers rax
441 Before, the former would print "<optimized out>", and the latter
442 "*value not available*".
444 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
449 ** Frame filters and frame decorators have been added.
450 ** Temporary breakpoints are now supported.
451 ** Line tables representation has been added.
452 ** New attribute 'parent_type' for gdb.Field objects.
453 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
454 ** New attribute 'name' for gdb.Type objects.
458 Nios II ELF nios2*-*-elf
459 Nios II GNU/Linux nios2*-*-linux
460 Texas Instruments MSP430 msp430*-*-elf
462 * Removed native configurations
464 Support for these a.out NetBSD and OpenBSD obsolete configurations has
465 been removed. ELF variants of these configurations are kept supported.
467 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
468 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
469 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
470 i[34567]86-*-openbsd3.[0-3]
471 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
472 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
473 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
477 Like "catch throw", but catches a re-thrown exception.
479 Renamed from old "maint check-symtabs".
481 Perform consistency checks on symtabs.
483 Expand symtabs matching an optional regexp.
486 Display the details of GDB configure-time options.
488 maint set|show per-command
489 maint set|show per-command space
490 maint set|show per-command time
491 maint set|show per-command symtab
492 Enable display of per-command gdb resource usage.
494 remove-symbol-file FILENAME
495 remove-symbol-file -a ADDRESS
496 Remove a symbol file added via add-symbol-file. The file to remove
497 can be identified by its filename or by an address that lies within
498 the boundaries of this symbol file in memory.
501 info exceptions REGEXP
502 Display the list of Ada exceptions defined in the program being
503 debugged. If provided, only the exceptions whose names match REGEXP
508 set debug symfile off|on
510 Control display of debugging info regarding reading symbol files and
511 symbol tables within those files
513 set print raw frame-arguments
514 show print raw frame-arguments
515 Set/show whether to print frame arguments in raw mode,
516 disregarding any defined pretty-printers.
518 set remote trace-status-packet
519 show remote trace-status-packet
520 Set/show the use of remote protocol qTStatus packet.
524 Control display of debugging messages related to Nios II targets.
528 Control whether target-assisted range stepping is enabled.
530 set startup-with-shell
531 show startup-with-shell
532 Specifies whether Unix child processes are started via a shell or
537 Use the target memory cache for accesses to the code segment. This
538 improves performance of remote debugging (particularly disassembly).
540 * You can now use a literal value 'unlimited' for options that
541 interpret 0 or -1 as meaning "unlimited". E.g., "set
542 trace-buffer-size unlimited" is now an alias for "set
543 trace-buffer-size -1" and "set height unlimited" is now an alias for
546 * The "set debug symtab-create" debugging option of GDB has been changed to
547 accept a verbosity level. 0 means "off", 1 provides basic debugging
548 output, and values of 2 or greater provides more verbose output.
550 * New command-line options
552 Display the details of GDB configure-time options.
554 * The command 'tsave' can now support new option '-ctf' to save trace
555 buffer in Common Trace Format.
557 * Newly installed $prefix/bin/gcore acts as a shell interface for the
560 * GDB now implements the the C++ 'typeid' operator.
562 * The new convenience variable $_exception holds the exception being
563 thrown or caught at an exception-related catchpoint.
565 * The exception-related catchpoints, like "catch throw", now accept a
566 regular expression which can be used to filter exceptions by type.
568 * The new convenience variable $_exitsignal is automatically set to
569 the terminating signal number when the program being debugged dies
570 due to an uncaught signal.
574 ** All MI commands now accept an optional "--language" option.
575 Support for this feature can be verified by using the "-list-features"
576 command, which should contain "language-option".
578 ** The new command -info-gdb-mi-command allows the user to determine
579 whether a GDB/MI command is supported or not.
581 ** The "^error" result record returned when trying to execute an undefined
582 GDB/MI command now provides a variable named "code" whose content is the
583 "undefined-command" error code. Support for this feature can be verified
584 by using the "-list-features" command, which should contain
585 "undefined-command-error-code".
587 ** The -trace-save MI command can optionally save trace buffer in Common
590 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
592 ** The command -data-list-register-values now accepts an optional
593 "--skip-unavailable" option. When used, only the available registers
596 ** The new command -trace-frame-collected dumps collected variables,
597 computed expressions, tvars, memory and registers in a traceframe.
599 ** The commands -stack-list-locals, -stack-list-arguments and
600 -stack-list-variables now accept an option "--skip-unavailable".
601 When used, only the available locals or arguments are displayed.
603 ** The -exec-run command now accepts an optional "--start" option.
604 When used, the command follows the same semantics as the "start"
605 command, stopping the program's execution at the start of its
606 main subprogram. Support for this feature can be verified using
607 the "-list-features" command, which should contain
608 "exec-run-start-option".
610 ** The new commands -catch-assert and -catch-exceptions insert
611 catchpoints stopping the program when Ada exceptions are raised.
613 ** The new command -info-ada-exceptions provides the equivalent of
614 the new "info exceptions" command.
616 * New system-wide configuration scripts
617 A GDB installation now provides scripts suitable for use as system-wide
618 configuration scripts for the following systems:
622 * GDB now supports target-assigned range stepping with remote targets.
623 This improves the performance of stepping source lines by reducing
624 the number of control packets from/to GDB. See "New remote packets"
627 * GDB now understands the element 'tvar' in the XML traceframe info.
628 It has the id of the collected trace state variables.
630 * On S/390 targets that provide the transactional-execution feature,
631 the program interruption transaction diagnostic block (TDB) is now
632 represented as a number of additional "registers" in GDB.
638 The vCont packet supports a new 'r' action, that tells the remote
639 stub to step through an address range itself, without GDB
640 involvemement at each single-step.
642 qXfer:libraries-svr4:read's annex
643 The previously unused annex of the qXfer:libraries-svr4:read packet
644 is now used to support passing an argument list. The remote stub
645 reports support for this argument list to GDB's qSupported query.
646 The defined arguments are "start" and "prev", used to reduce work
647 necessary for library list updating, resulting in significant
650 * New features in the GDB remote stub, GDBserver
652 ** GDBserver now supports target-assisted range stepping. Currently
653 enabled on x86/x86_64 GNU/Linux targets.
655 ** GDBserver now adds element 'tvar' in the XML in the reply to
656 'qXfer:traceframe-info:read'. It has the id of the collected
657 trace state variables.
659 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
662 * New 'z' formatter for printing and examining memory, this displays the
663 value as hexadecimal zero padded on the left to the size of the type.
665 * GDB can now use Windows x64 unwinding data.
667 * The "set remotebaud" command has been replaced by "set serial baud".
668 Similarly, "show remotebaud" has been replaced by "show serial baud".
669 The "set remotebaud" and "show remotebaud" commands are still available
670 to provide backward compatibility with older versions of GDB.
672 *** Changes in GDB 7.6
674 * Target record has been renamed to record-full.
675 Record/replay is now enabled with the "record full" command.
676 This also affects settings that are associated with full record/replay
677 that have been moved from "set/show record" to "set/show record full":
679 set|show record full insn-number-max
680 set|show record full stop-at-limit
681 set|show record full memory-query
683 * A new record target "record-btrace" has been added. The new target
684 uses hardware support to record the control-flow of a process. It
685 does not support replaying the execution, but it implements the
686 below new commands for investigating the recorded execution log.
687 This new recording method can be enabled using:
691 The "record-btrace" target is only available on Intel Atom processors
692 and requires a Linux kernel 2.6.32 or later.
694 * Two new commands have been added for record/replay to give information
695 about the recorded execution without having to replay the execution.
696 The commands are only supported by "record btrace".
698 record instruction-history prints the execution history at
699 instruction granularity
701 record function-call-history prints the execution history at
704 * New native configurations
706 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
707 FreeBSD/powerpc powerpc*-*-freebsd
708 x86_64/Cygwin x86_64-*-cygwin*
709 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
713 ARM AArch64 aarch64*-*-elf
714 ARM AArch64 GNU/Linux aarch64*-*-linux
715 Lynx 178 PowerPC powerpc-*-lynx*178
716 x86_64/Cygwin x86_64-*-cygwin*
717 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
719 * If the configured location of system.gdbinit file (as given by the
720 --with-system-gdbinit option at configure time) is in the
721 data-directory (as specified by --with-gdb-datadir at configure
722 time) or in one of its subdirectories, then GDB will look for the
723 system-wide init file in the directory specified by the
724 --data-directory command-line option.
726 * New command line options:
728 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
729 other initialization files, unlike -nx which disables all of them.
731 * Removed command line options
733 -epoch This was used by the gdb mode in Epoch, an ancient fork of
736 * The 'ptype' and 'whatis' commands now accept an argument to control
739 * 'info proc' now works on some core files.
743 ** Vectors can be created with gdb.Type.vector.
745 ** Python's atexit.register now works in GDB.
747 ** Types can be pretty-printed via a Python API.
749 ** Python 3 is now supported (in addition to Python 2.4 or later)
751 ** New class gdb.Architecture exposes GDB's internal representation
752 of architecture in the Python API.
754 ** New method Frame.architecture returns the gdb.Architecture object
755 corresponding to the frame's architecture.
757 * New Python-based convenience functions:
759 ** $_memeq(buf1, buf2, length)
760 ** $_streq(str1, str2)
762 ** $_regex(str, regex)
764 * The 'cd' command now defaults to using '~' (the home directory) if not
767 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
768 default for GCC since November 2000.
770 * The command 'forward-search' can now be abbreviated as 'fo'.
772 * The command 'info tracepoints' can now display 'installed on target'
773 or 'not installed on target' for each non-pending location of tracepoint.
775 * New configure options
777 --enable-libmcheck/--disable-libmcheck
778 By default, development versions are built with -lmcheck on hosts
779 that support it, in order to help track memory corruption issues.
780 Release versions, on the other hand, are built without -lmcheck
781 by default. The --enable-libmcheck/--disable-libmcheck configure
782 options allow the user to override that default.
783 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
784 This configure option allows the user to build GDB with
785 libbabeltrace using which GDB can read Common Trace Format data.
787 * New commands (for set/show, see "New options" below)
790 Catch signals. This is similar to "handle", but allows commands and
791 conditions to be attached.
794 List the BFDs known to GDB.
796 python-interactive [command]
798 Start a Python interactive prompt, or evaluate the optional command
799 and print the result of expressions.
802 "py" is a new alias for "python".
804 enable type-printer [name]...
805 disable type-printer [name]...
806 Enable or disable type printers.
810 ** For the Renesas Super-H architecture, the "regs" command has been removed
811 (has been deprecated in GDB 7.5), and "info all-registers" should be used
816 set print type methods (on|off)
817 show print type methods
818 Control whether method declarations are displayed by "ptype".
819 The default is to show them.
821 set print type typedefs (on|off)
822 show print type typedefs
823 Control whether typedef definitions are displayed by "ptype".
824 The default is to show them.
826 set filename-display basename|relative|absolute
827 show filename-display
828 Control the way in which filenames is displayed.
829 The default is "relative", which preserves previous behavior.
831 set trace-buffer-size
832 show trace-buffer-size
833 Request target to change the size of trace buffer.
835 set remote trace-buffer-size-packet auto|on|off
836 show remote trace-buffer-size-packet
837 Control the use of the remote protocol `QTBuffer:size' packet.
841 Control display of debugging messages related to ARM AArch64.
844 set debug coff-pe-read
845 show debug coff-pe-read
846 Control display of debugging messages related to reading of COFF/PE
851 Control display of debugging messages related to Mach-O symbols
854 set debug notification
855 show debug notification
856 Control display of debugging info for async remote notification.
860 ** Command parameter changes are now notified using new async record
861 "=cmd-param-changed".
862 ** Trace frame changes caused by command "tfind" are now notified using
863 new async record "=traceframe-changed".
864 ** The creation, deletion and modification of trace state variables
865 are now notified using new async records "=tsv-created",
866 "=tsv-deleted" and "=tsv-modified".
867 ** The start and stop of process record are now notified using new
868 async record "=record-started" and "=record-stopped".
869 ** Memory changes are now notified using new async record
871 ** The data-disassemble command response will include a "fullname" field
872 containing the absolute file name when source has been requested.
873 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
874 command, to allow pattern filling of memory areas.
875 ** New commands "-catch-load"/"-catch-unload" added for intercepting
876 library load/unload events.
877 ** The response to breakpoint commands and breakpoint async records
878 includes an "installed" field containing a boolean state about each
879 non-pending tracepoint location is whether installed on target or not.
880 ** Output of the "-trace-status" command includes a "trace-file" field
881 containing the name of the trace file being examined. This field is
882 optional, and only present when examining a trace file.
883 ** The "fullname" field is now always present along with the "file" field,
884 even if the file cannot be found by GDB.
886 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
887 You must have the LZMA library available when configuring GDB for this
888 feature to be enabled. For more information, see:
889 http://fedoraproject.org/wiki/Features/MiniDebugInfo
894 Set the size of trace buffer. The remote stub reports support for this
895 packet to gdb's qSupported query.
898 Enable Branch Trace Store (BTS)-based branch tracing for the current
899 thread. The remote stub reports support for this packet to gdb's
903 Disable branch tracing for the current thread. The remote stub reports
904 support for this packet to gdb's qSupported query.
907 Read the traced branches for the current thread. The remote stub
908 reports support for this packet to gdb's qSupported query.
910 *** Changes in GDB 7.5
912 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
913 for more x32 ABI info.
915 * GDB now supports access to MIPS DSP registers on Linux targets.
917 * GDB now supports debugging microMIPS binaries.
919 * The "info os" command on GNU/Linux can now display information on
920 several new classes of objects managed by the operating system:
921 "info os procgroups" lists process groups
922 "info os files" lists file descriptors
923 "info os sockets" lists internet-domain sockets
924 "info os shm" lists shared-memory regions
925 "info os semaphores" lists semaphores
926 "info os msg" lists message queues
927 "info os modules" lists loaded kernel modules
929 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
930 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
931 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
932 options and inspect the probe arguments using the new $_probe_arg family
933 of convenience variables. You can obtain more information about SystemTap
934 in <http://sourceware.org/systemtap/>.
936 * GDB now supports reversible debugging on ARM, it allows you to
937 debug basic ARM and THUMB instructions, and provides
938 record/replay support.
940 * The option "symbol-reloading" has been deleted as it is no longer used.
944 ** GDB commands implemented in Python can now be put in command class
947 ** The "maint set python print-stack on|off" is now deleted.
949 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
950 apply "flag enum"-style pretty-printing to any enum.
952 ** gdb.lookup_symbol can now work when there is no current frame.
954 ** gdb.Symbol now has a 'line' attribute, holding the line number in
955 the source at which the symbol was defined.
957 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
958 method 'value'. The former indicates whether the symbol needs a
959 frame in order to compute its value, and the latter computes the
962 ** A new method 'referenced_value' on gdb.Value objects which can
963 dereference pointer as well as C++ reference values.
965 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
966 which return the global and static blocks (as gdb.Block objects),
967 of the underlying symbol table, respectively.
969 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
970 object associated with a PC value.
972 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
973 of the address range occupied by code for the current source line.
975 * Go language support.
976 GDB now supports debugging programs written in the Go programming
979 * GDBserver now supports stdio connections.
980 E.g. (gdb) target remote | ssh myhost gdbserver - hello
982 * The binary "gdbtui" can no longer be built or installed.
983 Use "gdb -tui" instead.
985 * GDB will now print "flag" enums specially. A flag enum is one where
986 all the enumerator values have no bits in common when pairwise
987 "and"ed. When printing a value whose type is a flag enum, GDB will
988 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
989 (gdb) print (enum E) 3
992 * The filename part of a linespec will now match trailing components
993 of a source file name. For example, "break gcc/expr.c:1000" will
994 now set a breakpoint in build/gcc/expr.c, but not
997 * The "info proc" and "generate-core-file" commands will now also
998 work on remote targets connected to GDBserver on Linux.
1000 * The command "info catch" has been removed. It has been disabled
1001 since December 2007.
1003 * The "catch exception" and "catch assert" commands now accept
1004 a condition at the end of the command, much like the "break"
1005 command does. For instance:
1007 (gdb) catch exception Constraint_Error if Barrier = True
1009 Previously, it was possible to add a condition to such catchpoints,
1010 but it had to be done as a second step, after the catchpoint had been
1011 created, using the "condition" command.
1013 * The "info static-tracepoint-marker" command will now also work on
1014 native Linux targets with in-process agent.
1016 * GDB can now set breakpoints on inlined functions.
1018 * The .gdb_index section has been updated to include symbols for
1019 inlined functions. GDB will ignore older .gdb_index sections by
1020 default, which could cause symbol files to be loaded more slowly
1021 until their .gdb_index sections can be recreated. The new command
1022 "set use-deprecated-index-sections on" will cause GDB to use any older
1023 .gdb_index sections it finds. This will restore performance, but the
1024 ability to set breakpoints on inlined functions will be lost in symbol
1025 files with older .gdb_index sections.
1027 The .gdb_index section has also been updated to record more information
1028 about each symbol. This speeds up the "info variables", "info functions"
1029 and "info types" commands when used with programs having the .gdb_index
1030 section, as well as speeding up debugging with shared libraries using
1031 the .gdb_index section.
1033 * Ada support for GDB/MI Variable Objects has been added.
1035 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1040 ** New command -info-os is the MI equivalent of "info os".
1042 ** Output logs ("set logging" and related) now include MI output.
1046 ** "set use-deprecated-index-sections on|off"
1047 "show use-deprecated-index-sections on|off"
1048 Controls the use of deprecated .gdb_index sections.
1050 ** "catch load" and "catch unload" can be used to stop when a shared
1051 library is loaded or unloaded, respectively.
1053 ** "enable count" can be used to auto-disable a breakpoint after
1056 ** "info vtbl" can be used to show the virtual method tables for
1057 C++ and Java objects.
1059 ** "explore" and its sub commands "explore value" and "explore type"
1060 can be used to recursively explore values and types of
1061 expressions. These commands are available only if GDB is
1062 configured with '--with-python'.
1064 ** "info auto-load" shows status of all kinds of auto-loaded files,
1065 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1066 sequences of commands files, "info auto-load python-scripts"
1067 shows status of auto-loading Python script files,
1068 "info auto-load local-gdbinit" shows status of loading init file
1069 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1070 status of inferior specific thread debugging shared library loading.
1072 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1073 and "show auto-load-scripts" commands have been deprecated, use their
1074 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1075 and "show auto-load python-scripts" counterparts instead.
1077 ** "dprintf location,format,args..." creates a dynamic printf, which
1078 is basically a breakpoint that does a printf and immediately
1079 resumes your program's execution, so it is like a printf that you
1080 can insert dynamically at runtime instead of at compiletime.
1082 ** "set print symbol"
1084 Controls whether GDB attempts to display the symbol, if any,
1085 corresponding to addresses it prints. This defaults to "on", but
1086 you can set it to "off" to restore GDB's previous behavior.
1088 * Deprecated commands
1090 ** For the Renesas Super-H architecture, the "regs" command has been
1091 deprecated, and "info all-registers" should be used instead.
1095 Renesas RL78 rl78-*-elf
1096 HP OpenVMS ia64 ia64-hp-openvms*
1098 * GDBserver supports evaluation of breakpoint conditions. When
1099 support is advertised by GDBserver, GDB may be told to send the
1100 breakpoint conditions in bytecode form to GDBserver. GDBserver
1101 will only report the breakpoint trigger to GDB when its condition
1106 set mips compression
1107 show mips compression
1108 Select the compressed ISA encoding used in functions that have no symbol
1109 information available. The encoding can be set to either of:
1112 and is updated automatically from ELF file flags if available.
1114 set breakpoint condition-evaluation
1115 show breakpoint condition-evaluation
1116 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1117 GDBserver ("target"). Default option "auto" chooses the most efficient
1119 This option can improve debugger efficiency depending on the speed of the
1123 Disable auto-loading globally.
1126 Show auto-loading setting of all kinds of auto-loaded files.
1128 set auto-load gdb-scripts on|off
1129 show auto-load gdb-scripts
1130 Control auto-loading of GDB canned sequences of commands files.
1132 set auto-load python-scripts on|off
1133 show auto-load python-scripts
1134 Control auto-loading of Python script files.
1136 set auto-load local-gdbinit on|off
1137 show auto-load local-gdbinit
1138 Control loading of init file (.gdbinit) from current directory.
1140 set auto-load libthread-db on|off
1141 show auto-load libthread-db
1142 Control auto-loading of inferior specific thread debugging shared library.
1144 set auto-load scripts-directory <dir1>[:<dir2>...]
1145 show auto-load scripts-directory
1146 Set a list of directories from which to load auto-loaded scripts.
1147 Automatically loaded Python scripts and GDB scripts are located in one
1148 of the directories listed by this option.
1149 The delimiter (':' above) may differ according to the host platform.
1151 set auto-load safe-path <dir1>[:<dir2>...]
1152 show auto-load safe-path
1153 Set a list of directories from which it is safe to auto-load files.
1154 The delimiter (':' above) may differ according to the host platform.
1156 set debug auto-load on|off
1157 show debug auto-load
1158 Control display of debugging info for auto-loading the files above.
1160 set dprintf-style gdb|call|agent
1162 Control the way in which a dynamic printf is performed; "gdb"
1163 requests a GDB printf command, while "call" causes dprintf to call a
1164 function in the inferior. "agent" requests that the target agent
1165 (such as GDBserver) do the printing.
1167 set dprintf-function <expr>
1168 show dprintf-function
1169 set dprintf-channel <expr>
1170 show dprintf-channel
1171 Set the function and optional first argument to the call when using
1172 the "call" style of dynamic printf.
1174 set disconnected-dprintf on|off
1175 show disconnected-dprintf
1176 Control whether agent-style dynamic printfs continue to be in effect
1177 after GDB disconnects.
1179 * New configure options
1181 --with-auto-load-dir
1182 Configure default value for the 'set auto-load scripts-directory'
1183 setting above. It defaults to '$debugdir:$datadir/auto-load',
1184 $debugdir representing global debugging info directories (available
1185 via 'show debug-file-directory') and $datadir representing GDB's data
1186 directory (available via 'show data-directory').
1188 --with-auto-load-safe-path
1189 Configure default value for the 'set auto-load safe-path' setting
1190 above. It defaults to the --with-auto-load-dir setting.
1192 --without-auto-load-safe-path
1193 Set 'set auto-load safe-path' to '/', effectively disabling this
1196 * New remote packets
1198 z0/z1 conditional breakpoints extension
1200 The z0/z1 breakpoint insertion packets have been extended to carry
1201 a list of conditional expressions over to the remote stub depending on the
1202 condition evaluation mode. The use of this extension can be controlled
1203 via the "set remote conditional-breakpoints-packet" command.
1207 Specify the signals which the remote stub may pass to the debugged
1208 program without GDB involvement.
1210 * New command line options
1212 --init-command=FILE, -ix Like --command, -x but execute it
1213 before loading inferior.
1214 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1215 execute it before loading inferior.
1217 *** Changes in GDB 7.4
1219 * GDB now handles ambiguous linespecs more consistently; the existing
1220 FILE:LINE support has been expanded to other types of linespecs. A
1221 breakpoint will now be set on all matching locations in all
1222 inferiors, and locations will be added or removed according to
1225 * GDB now allows you to skip uninteresting functions and files when
1226 stepping with the "skip function" and "skip file" commands.
1228 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1229 and "show remote hardware-watchpoint-length-limit". These allows to
1230 set or show the maximum length limit (in bytes) of a remote
1231 target hardware watchpoint.
1233 This allows e.g. to use "unlimited" hardware watchpoints with the
1234 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1235 watchpoints are slower than real hardware watchpoints but are
1236 significantly faster than gdb software watchpoints.
1240 ** The register_pretty_printer function in module gdb.printing now takes
1241 an optional `replace' argument. If True, the new printer replaces any
1244 ** The "maint set python print-stack on|off" command has been
1245 deprecated and will be deleted in GDB 7.5.
1246 A new command: "set python print-stack none|full|message" has
1247 replaced it. Additionally, the default for "print-stack" is
1248 now "message", which just prints the error message without
1251 ** A prompt substitution hook (prompt_hook) is now available to the
1254 ** A new Python module, gdb.prompt has been added to the GDB Python
1255 modules library. This module provides functionality for
1256 escape sequences in prompts (used by set/show
1257 extended-prompt). These escape sequences are replaced by their
1258 corresponding value.
1260 ** Python commands and convenience-functions located in
1261 'data-directory'/python/gdb/command and
1262 'data-directory'/python/gdb/function are now automatically loaded
1265 ** Blocks now provide four new attributes. global_block and
1266 static_block will return the global and static blocks
1267 respectively. is_static and is_global are boolean attributes
1268 that indicate if the block is one of those two types.
1270 ** Symbols now provide the "type" attribute, the type of the symbol.
1272 ** The "gdb.breakpoint" function has been deprecated in favor of
1275 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1276 of a function. This class is based on the "finish" command
1277 available in the CLI.
1279 ** Type objects for struct and union types now allow access to
1280 the fields using standard Python dictionary (mapping) methods.
1281 For example, "some_type['myfield']" now works, as does
1282 "some_type.items()".
1284 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1287 ** A new function, "deep_items" has been added to the gdb.types
1288 module in the GDB Python modules library. This function returns
1289 an iterator over the fields of a struct or union type. Unlike
1290 the standard Python "iteritems" method, it will recursively traverse
1291 any anonymous fields.
1295 ** "*stopped" events can report several new "reason"s, such as
1298 ** Breakpoint changes are now notified using new async records, like
1299 "=breakpoint-modified".
1301 ** New command -ada-task-info.
1303 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1304 $sdir specifies the default system locations of shared libraries.
1305 $pdir specifies the directory where the libpthread used by the application
1308 GDB no longer looks in $sdir and $pdir after it has searched the directories
1309 mentioned in libthread-db-search-path. If you want to search those
1310 directories, they must be specified in libthread-db-search-path.
1311 The default value of libthread-db-search-path on GNU/Linux and Solaris
1312 systems is now "$sdir:$pdir".
1314 $pdir is not supported by gdbserver, it is currently ignored.
1315 $sdir is supported by gdbserver.
1317 * New configure option --with-iconv-bin.
1318 When using the internationalization support like the one in the GNU C
1319 library, GDB will invoke the "iconv" program to get a list of supported
1320 character sets. If this program lives in a non-standard location, one can
1321 use this option to specify where to find it.
1323 * When natively debugging programs on PowerPC BookE processors running
1324 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1325 watchpoints, which specify a mask in addition to an address to watch.
1326 The mask specifies that some bits of an address (the bits which are
1327 reset in the mask) should be ignored when matching the address accessed
1328 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1329 section in the user manual for more details.
1331 * The new option --once causes GDBserver to stop listening for connections once
1332 the first connection is made. The listening port used by GDBserver will
1333 become available after that.
1335 * New commands "info macros" and "alias" have been added.
1337 * New function parameters suffix @entry specifies value of function parameter
1338 at the time the function got called. Entry values are available only since
1344 "!" is now an alias of the "shell" command.
1345 Note that no space is needed between "!" and SHELL COMMAND.
1349 watch EXPRESSION mask MASK_VALUE
1350 The watch command now supports the mask argument which allows creation
1351 of masked watchpoints, if the current architecture supports this feature.
1353 info auto-load-scripts [REGEXP]
1354 This command was formerly named "maintenance print section-scripts".
1355 It is now generally useful and is no longer a maintenance-only command.
1357 info macro [-all] [--] MACRO
1358 The info macro command has new options `-all' and `--'. The first for
1359 printing all definitions of a macro. The second for explicitly specifying
1360 the end of arguments and the beginning of the macro name in case the macro
1361 name starts with a hyphen.
1363 collect[/s] EXPRESSIONS
1364 The tracepoint collect command now takes an optional modifier "/s"
1365 that directs it to dereference pointer-to-character types and
1366 collect the bytes of memory up to a zero byte. The behavior is
1367 similar to what you see when you use the regular print command on a
1368 string. An optional integer following the "/s" sets a bound on the
1369 number of bytes that will be collected.
1372 The trace start command now interprets any supplied arguments as a
1373 note to be recorded with the trace run, with an effect similar to
1374 setting the variable trace-notes.
1377 The trace stop command now interprets any arguments as a note to be
1378 mentioned along with the tstatus report that the trace was stopped
1379 with a command. The effect is similar to setting the variable
1382 * Tracepoints can now be enabled and disabled at any time after a trace
1383 experiment has been started using the standard "enable" and "disable"
1384 commands. It is now possible to start a trace experiment with no enabled
1385 tracepoints; GDB will display a warning, but will allow the experiment to
1386 begin, assuming that tracepoints will be enabled as needed while the trace
1389 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1390 locations with 4-byte instructions, when they were previously
1391 limited to locations with instructions of 5 bytes or longer.
1395 set debug dwarf2-read
1396 show debug dwarf2-read
1397 Turns on or off display of debugging messages related to reading
1398 DWARF debug info. The default is off.
1400 set debug symtab-create
1401 show debug symtab-create
1402 Turns on or off display of debugging messages related to symbol table
1403 creation. The default is off.
1406 show extended-prompt
1407 Set the GDB prompt, and allow escape sequences to be inserted to
1408 display miscellaneous information (see 'help set extended-prompt'
1409 for the list of sequences). This prompt (and any information
1410 accessed through the escape sequences) is updated every time the
1411 prompt is displayed.
1413 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1414 show print entry-values
1415 Set printing of frame argument values at function entry. In some cases
1416 GDB can determine the value of function argument which was passed by the
1417 function caller, even if the value was modified inside the called function.
1419 set debug entry-values
1420 show debug entry-values
1421 Control display of debugging info for determining frame argument values at
1422 function entry and virtual tail call frames.
1424 set basenames-may-differ
1425 show basenames-may-differ
1426 Set whether a source file may have multiple base names.
1427 (A "base name" is the name of a file with the directory part removed.
1428 Example: The base name of "/home/user/hello.c" is "hello.c".)
1429 If set, GDB will canonicalize file names (e.g., expand symlinks)
1430 before comparing them. Canonicalization is an expensive operation,
1431 but it allows the same file be known by more than one base name.
1432 If not set (the default), all source files are assumed to have just
1433 one base name, and gdb will do file name comparisons more efficiently.
1439 Set a user name and notes for the current and any future trace runs.
1440 This is useful for long-running and/or disconnected traces, to
1441 inform others (or yourself) as to who is running the trace, supply
1442 contact information, or otherwise explain what is going on.
1444 set trace-stop-notes
1445 show trace-stop-notes
1446 Set a note attached to the trace run, that is displayed when the
1447 trace has been stopped by a tstop command. This is useful for
1448 instance as an explanation, if you are stopping a trace run that was
1449 started by someone else.
1451 * New remote packets
1455 Dynamically enable a tracepoint in a started trace experiment.
1459 Dynamically disable a tracepoint in a started trace experiment.
1463 Set the user and notes of the trace run.
1467 Query the current status of a tracepoint.
1471 Query the minimum length of instruction at which a fast tracepoint may
1474 * Dcache size (number of lines) and line-size are now runtime-configurable
1475 via "set dcache line" and "set dcache line-size" commands.
1479 Texas Instruments TMS320C6x tic6x-*-*
1483 Renesas RL78 rl78-*-elf
1485 *** Changes in GDB 7.3.1
1487 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1489 *** Changes in GDB 7.3
1491 * GDB has a new command: "thread find [REGEXP]".
1492 It finds the thread id whose name, target id, or thread extra info
1493 matches the given regular expression.
1495 * The "catch syscall" command now works on mips*-linux* targets.
1497 * The -data-disassemble MI command now supports modes 2 and 3 for
1498 dumping the instruction opcodes.
1500 * New command line options
1502 -data-directory DIR Specify DIR as the "data-directory".
1503 This is mostly for testing purposes.
1505 * The "maint set python auto-load on|off" command has been renamed to
1506 "set auto-load-scripts on|off".
1508 * GDB has a new command: "set directories".
1509 It is like the "dir" command except that it replaces the
1510 source path list instead of augmenting it.
1512 * GDB now understands thread names.
1514 On GNU/Linux, "info threads" will display the thread name as set by
1515 prctl or pthread_setname_np.
1517 There is also a new command, "thread name", which can be used to
1518 assign a name internally for GDB to display.
1521 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1522 has been integrated into GDB.
1526 ** The function gdb.Write now accepts an optional keyword 'stream'.
1527 This keyword, when provided, will direct the output to either
1528 stdout, stderr, or GDB's logging output.
1530 ** Parameters can now be be sub-classed in Python, and in particular
1531 you may implement the get_set_doc and get_show_doc functions.
1532 This improves how Parameter set/show documentation is processed
1533 and allows for more dynamic content.
1535 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1536 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1537 have an is_valid method.
1539 ** Breakpoints can now be sub-classed in Python, and in particular
1540 you may implement a 'stop' function that is executed each time
1541 the inferior reaches that breakpoint.
1543 ** New function gdb.lookup_global_symbol looks up a global symbol.
1545 ** GDB values in Python are now callable if the value represents a
1546 function. For example, if 'some_value' represents a function that
1547 takes two integer parameters and returns a value, you can call
1548 that function like so:
1550 result = some_value (10,20)
1552 ** Module gdb.types has been added.
1553 It contains a collection of utilities for working with gdb.Types objects:
1554 get_basic_type, has_field, make_enum_dict.
1556 ** Module gdb.printing has been added.
1557 It contains utilities for writing and registering pretty-printers.
1558 New classes: PrettyPrinter, SubPrettyPrinter,
1559 RegexpCollectionPrettyPrinter.
1560 New function: register_pretty_printer.
1562 ** New commands "info pretty-printers", "enable pretty-printer" and
1563 "disable pretty-printer" have been added.
1565 ** gdb.parameter("directories") is now available.
1567 ** New function gdb.newest_frame returns the newest frame in the
1570 ** The gdb.InferiorThread class has a new "name" attribute. This
1571 holds the thread's name.
1573 ** Python Support for Inferior events.
1574 Python scripts can add observers to be notified of events
1575 occurring in the process being debugged.
1576 The following events are currently supported:
1577 - gdb.events.cont Continue event.
1578 - gdb.events.exited Inferior exited event.
1579 - gdb.events.stop Signal received, and Breakpoint hit events.
1583 ** GDB now puts template parameters in scope when debugging in an
1584 instantiation. For example, if you have:
1586 template<int X> int func (void) { return X; }
1588 then if you step into func<5>, "print X" will show "5". This
1589 feature requires proper debuginfo support from the compiler; it
1590 was added to GCC 4.5.
1592 ** The motion commands "next", "finish", "until", and "advance" now
1593 work better when exceptions are thrown. In particular, GDB will
1594 no longer lose control of the inferior; instead, the GDB will
1595 stop the inferior at the point at which the exception is caught.
1596 This functionality requires a change in the exception handling
1597 code that was introduced in GCC 4.5.
1599 * GDB now follows GCC's rules on accessing volatile objects when
1600 reading or writing target state during expression evaluation.
1601 One notable difference to prior behavior is that "print x = 0"
1602 no longer generates a read of x; the value of the assignment is
1603 now always taken directly from the value being assigned.
1605 * GDB now has some support for using labels in the program's source in
1606 linespecs. For instance, you can use "advance label" to continue
1607 execution to a label.
1609 * GDB now has support for reading and writing a new .gdb_index
1610 section. This section holds a fast index of DWARF debugging
1611 information and can be used to greatly speed up GDB startup and
1612 operation. See the documentation for `save gdb-index' for details.
1614 * The "watch" command now accepts an optional "-location" argument.
1615 When used, this causes GDB to watch the memory referred to by the
1616 expression. Such a watchpoint is never deleted due to it going out
1619 * GDB now supports thread debugging of core dumps on GNU/Linux.
1621 GDB now activates thread debugging using the libthread_db library
1622 when debugging GNU/Linux core dumps, similarly to when debugging
1623 live processes. As a result, when debugging a core dump file, GDB
1624 is now able to display pthread_t ids of threads. For example, "info
1625 threads" shows the same output as when debugging the process when it
1626 was live. In earlier releases, you'd see something like this:
1629 * 1 LWP 6780 main () at main.c:10
1631 While now you see this:
1634 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1636 It is also now possible to inspect TLS variables when debugging core
1639 When debugging a core dump generated on a machine other than the one
1640 used to run GDB, you may need to point GDB at the correct
1641 libthread_db library with the "set libthread-db-search-path"
1642 command. See the user manual for more details on this command.
1644 * When natively debugging programs on PowerPC BookE processors running
1645 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1646 which stop execution of the inferior whenever it executes an instruction
1647 at any address within the specified range. See the "PowerPC Embedded"
1648 section in the user manual for more details.
1650 * New features in the GDB remote stub, GDBserver
1652 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1653 and i686 LynxOS (version 5.x).
1655 ** GDBserver is now supported on Blackfin Linux.
1657 * New native configurations
1659 ia64 HP-UX ia64-*-hpux*
1663 Analog Devices, Inc. Blackfin Processor bfin-*
1665 * Ada task switching is now supported on sparc-elf targets when
1666 debugging a program using the Ravenscar Profile. For more information,
1667 see the "Tasking Support when using the Ravenscar Profile" section
1668 in the GDB user manual.
1670 * Guile support was removed.
1672 * New features in the GNU simulator
1674 ** The --map-info flag lists all known core mappings.
1676 ** CFI flashes may be simulated via the "cfi" device.
1678 *** Changes in GDB 7.2
1680 * Shared library support for remote targets by default
1682 When GDB is configured for a generic, non-OS specific target, like
1683 for example, --target=arm-eabi or one of the many *-*-elf targets,
1684 GDB now queries remote stubs for loaded shared libraries using the
1685 `qXfer:libraries:read' packet. Previously, shared library support
1686 was always disabled for such configurations.
1690 ** Argument Dependent Lookup (ADL)
1692 In C++ ADL lookup directs function search to the namespaces of its
1693 arguments even if the namespace has not been imported.
1703 Here the compiler will search for `foo' in the namespace of 'b'
1704 and find A::foo. GDB now supports this. This construct is commonly
1705 used in the Standard Template Library for operators.
1707 ** Improved User Defined Operator Support
1709 In addition to member operators, GDB now supports lookup of operators
1710 defined in a namespace and imported with a `using' directive, operators
1711 defined in the global scope, operators imported implicitly from an
1712 anonymous namespace, and the ADL operators mentioned in the previous
1714 GDB now also supports proper overload resolution for all the previously
1715 mentioned flavors of operators.
1717 ** static const class members
1719 Printing of static const class members that are initialized in the
1720 class definition has been fixed.
1722 * Windows Thread Information Block access.
1724 On Windows targets, GDB now supports displaying the Windows Thread
1725 Information Block (TIB) structure. This structure is visible either
1726 by using the new command `info w32 thread-information-block' or, by
1727 dereferencing the new convenience variable named `$_tlb', a
1728 thread-specific pointer to the TIB. This feature is also supported
1729 when remote debugging using GDBserver.
1731 * Static tracepoints
1733 Static tracepoints are calls in the user program into a tracing
1734 library. One such library is a port of the LTTng kernel tracer to
1735 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1736 When debugging with GDBserver, GDB now supports combining the GDB
1737 tracepoint machinery with such libraries. For example: the user can
1738 use GDB to probe a static tracepoint marker (a call from the user
1739 program into the tracing library) with the new "strace" command (see
1740 "New commands" below). This creates a "static tracepoint" in the
1741 breakpoint list, that can be manipulated with the same feature set
1742 as fast and regular tracepoints. E.g., collect registers, local and
1743 global variables, collect trace state variables, and define
1744 tracepoint conditions. In addition, the user can collect extra
1745 static tracepoint marker specific data, by collecting the new
1746 $_sdata internal variable. When analyzing the trace buffer, you can
1747 inspect $_sdata like any other variable available to GDB. For more
1748 information, see the "Tracepoints" chapter in GDB user manual. New
1749 remote packets have been defined to support static tracepoints, see
1750 the "New remote packets" section below.
1752 * Better reconstruction of tracepoints after disconnected tracing
1754 GDB will attempt to download the original source form of tracepoint
1755 definitions when starting a trace run, and then will upload these
1756 upon reconnection to the target, resulting in a more accurate
1757 reconstruction of the tracepoints that are in use on the target.
1761 You can now exercise direct control over the ways that GDB can
1762 affect your program. For instance, you can disallow the setting of
1763 breakpoints, so that the program can run continuously (assuming
1764 non-stop mode). In addition, the "observer" variable is available
1765 to switch all of the different controls; in observer mode, GDB
1766 cannot affect the target's behavior at all, which is useful for
1767 tasks like diagnosing live systems in the field.
1769 * The new convenience variable $_thread holds the number of the
1772 * New remote packets
1776 Return the address of the Windows Thread Information Block of a given thread.
1780 In response to several of the tracepoint packets, the target may now
1781 also respond with a number of intermediate `qRelocInsn' request
1782 packets before the final result packet, to have GDB handle
1783 relocating an instruction to execute at a different address. This
1784 is particularly useful for stubs that support fast tracepoints. GDB
1785 reports support for this feature in the qSupported packet.
1789 List static tracepoint markers in the target program.
1793 List static tracepoint markers at a given address in the target
1796 qXfer:statictrace:read
1798 Read the static trace data collected (by a `collect $_sdata'
1799 tracepoint action). The remote stub reports support for this packet
1800 to gdb's qSupported query.
1804 Send the current settings of GDB's permission flags.
1808 Send part of the source (textual) form of a tracepoint definition,
1809 which includes location, conditional, and action list.
1811 * The source command now accepts a -s option to force searching for the
1812 script in the source search path even if the script name specifies
1815 * New features in the GDB remote stub, GDBserver
1817 - GDBserver now support tracepoints (including fast tracepoints, and
1818 static tracepoints). The feature is currently supported by the
1819 i386-linux and amd64-linux builds. See the "Tracepoints support
1820 in gdbserver" section in the manual for more information.
1822 GDBserver JIT compiles the tracepoint's conditional agent
1823 expression bytecode into native code whenever possible for low
1824 overhead dynamic tracepoints conditionals. For such tracepoints,
1825 an expression that examines program state is evaluated when the
1826 tracepoint is reached, in order to determine whether to capture
1827 trace data. If the condition is simple and false, processing the
1828 tracepoint finishes very quickly and no data is gathered.
1830 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1831 for static tracepoints support.
1833 - GDBserver now supports x86_64 Windows 64-bit debugging.
1835 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1836 it understands register description.
1838 * The --batch flag now disables pagination and queries.
1840 * X86 general purpose registers
1842 GDB now supports reading/writing byte, word and double-word x86
1843 general purpose registers directly. This means you can use, say,
1844 $ah or $ax to refer, respectively, to the byte register AH and
1845 16-bit word register AX that are actually portions of the 32-bit
1846 register EAX or 64-bit register RAX.
1848 * The `commands' command now accepts a range of breakpoints to modify.
1849 A plain `commands' following a command that creates multiple
1850 breakpoints affects all the breakpoints set by that command. This
1851 applies to breakpoints set by `rbreak', and also applies when a
1852 single `break' command creates multiple breakpoints (e.g.,
1853 breakpoints on overloaded c++ functions).
1855 * The `rbreak' command now accepts a filename specification as part of
1856 its argument, limiting the functions selected by the regex to those
1857 in the specified file.
1859 * Support for remote debugging Windows and SymbianOS shared libraries
1860 from Unix hosts has been improved. Non Windows GDB builds now can
1861 understand target reported file names that follow MS-DOS based file
1862 system semantics, such as file names that include drive letters and
1863 use the backslash character as directory separator. This makes it
1864 possible to transparently use the "set sysroot" and "set
1865 solib-search-path" on Unix hosts to point as host copies of the
1866 target's shared libraries. See the new command "set
1867 target-file-system-kind" described below, and the "Commands to
1868 specify files" section in the user manual for more information.
1872 eval template, expressions...
1873 Convert the values of one or more expressions under the control
1874 of the string template to a command line, and call it.
1876 set target-file-system-kind unix|dos-based|auto
1877 show target-file-system-kind
1878 Set or show the assumed file system kind for target reported file
1881 save breakpoints <filename>
1882 Save all current breakpoint definitions to a file suitable for use
1883 in a later debugging session. To read the saved breakpoint
1884 definitions, use the `source' command.
1886 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1889 info static-tracepoint-markers
1890 Display information about static tracepoint markers in the target.
1892 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1893 Define a static tracepoint by probing a marker at the given
1894 function, line, address, or marker ID.
1898 Enable and disable observer mode.
1900 set may-write-registers on|off
1901 set may-write-memory on|off
1902 set may-insert-breakpoints on|off
1903 set may-insert-tracepoints on|off
1904 set may-insert-fast-tracepoints on|off
1905 set may-interrupt on|off
1906 Set individual permissions for GDB effects on the target. Note that
1907 some of these settings can have undesirable or surprising
1908 consequences, particularly when changed in the middle of a session.
1909 For instance, disabling the writing of memory can prevent
1910 breakpoints from being inserted, cause single-stepping to fail, or
1911 even crash your program, if you disable after breakpoints have been
1912 inserted. However, GDB should not crash.
1914 set record memory-query on|off
1915 show record memory-query
1916 Control whether to stop the inferior if memory changes caused
1917 by an instruction cannot be recorded.
1922 The disassemble command now supports "start,+length" form of two arguments.
1926 ** GDB now provides a new directory location, called the python directory,
1927 where Python scripts written for GDB can be installed. The location
1928 of that directory is <data-directory>/python, where <data-directory>
1929 is the GDB data directory. For more details, see section `Scripting
1930 GDB using Python' in the manual.
1932 ** The GDB Python API now has access to breakpoints, symbols, symbol
1933 tables, program spaces, inferiors, threads and frame's code blocks.
1934 Additionally, GDB Parameters can now be created from the API, and
1935 manipulated via set/show in the CLI.
1937 ** New functions gdb.target_charset, gdb.target_wide_charset,
1938 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1940 ** New exception gdb.GdbError.
1942 ** Pretty-printers are now also looked up in the current program space.
1944 ** Pretty-printers can now be individually enabled and disabled.
1946 ** GDB now looks for names of Python scripts to auto-load in a
1947 special section named `.debug_gdb_scripts', in addition to looking
1948 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1950 * Tracepoint actions were unified with breakpoint commands. In particular,
1951 there are no longer differences in "info break" output for breakpoints and
1952 tracepoints and the "commands" command can be used for both tracepoints and
1953 regular breakpoints.
1957 ARM Symbian arm*-*-symbianelf*
1959 * D language support.
1960 GDB now supports debugging programs written in the D programming
1963 * GDB now supports the extended ptrace interface for PowerPC which is
1964 available since Linux kernel version 2.6.34. This automatically enables
1965 any hardware breakpoints and additional hardware watchpoints available in
1966 the processor. The old ptrace interface exposes just one hardware
1967 watchpoint and no hardware breakpoints.
1969 * GDB is now able to use the Data Value Compare (DVC) register available on
1970 embedded PowerPC processors to implement in hardware simple watchpoint
1971 conditions of the form:
1973 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1975 This works in native GDB running on Linux kernels with the extended ptrace
1976 interface mentioned above.
1978 *** Changes in GDB 7.1
1982 ** Namespace Support
1984 GDB now supports importing of namespaces in C++. This enables the
1985 user to inspect variables from imported namespaces. Support for
1986 namepace aliasing has also been added. So, if a namespace is
1987 aliased in the current scope (e.g. namepace C=A; ) the user can
1988 print variables using the alias (e.g. (gdb) print C::x).
1992 All known bugs relating to the printing of virtual base class were
1993 fixed. It is now possible to call overloaded static methods using a
1998 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1999 and reinterpret_cast<> are now handled by the C++ expression parser.
2003 Xilinx MicroBlaze microblaze-*-*
2008 Xilinx MicroBlaze microblaze
2011 * Multi-program debugging.
2013 GDB now has support for multi-program (a.k.a. multi-executable or
2014 multi-exec) debugging. This allows for debugging multiple inferiors
2015 simultaneously each running a different program under the same GDB
2016 session. See "Debugging Multiple Inferiors and Programs" in the
2017 manual for more information. This implied some user visible changes
2018 in the multi-inferior support. For example, "info inferiors" now
2019 lists inferiors that are not running yet or that have exited
2020 already. See also "New commands" and "New options" below.
2022 * New tracing features
2024 GDB's tracepoint facility now includes several new features:
2026 ** Trace state variables
2028 GDB tracepoints now include support for trace state variables, which
2029 are variables managed by the target agent during a tracing
2030 experiment. They are useful for tracepoints that trigger each
2031 other, so for instance one tracepoint can count hits in a variable,
2032 and then a second tracepoint has a condition that is true when the
2033 count reaches a particular value. Trace state variables share the
2034 $-syntax of GDB convenience variables, and can appear in both
2035 tracepoint actions and condition expressions. Use the "tvariable"
2036 command to create, and "info tvariables" to view; see "Trace State
2037 Variables" in the manual for more detail.
2041 GDB now includes an option for defining fast tracepoints, which
2042 targets may implement more efficiently, such as by installing a jump
2043 into the target agent rather than a trap instruction. The resulting
2044 speedup can be by two orders of magnitude or more, although the
2045 tradeoff is that some program locations on some target architectures
2046 might not allow fast tracepoint installation, for instance if the
2047 instruction to be replaced is shorter than the jump. To request a
2048 fast tracepoint, use the "ftrace" command, with syntax identical to
2049 the regular trace command.
2051 ** Disconnected tracing
2053 It is now possible to detach GDB from the target while it is running
2054 a trace experiment, then reconnect later to see how the experiment
2055 is going. In addition, a new variable disconnected-tracing lets you
2056 tell the target agent whether to continue running a trace if the
2057 connection is lost unexpectedly.
2061 GDB now has the ability to save the trace buffer into a file, and
2062 then use that file as a target, similarly to you can do with
2063 corefiles. You can select trace frames, print data that was
2064 collected in them, and use tstatus to display the state of the
2065 tracing run at the moment that it was saved. To create a trace
2066 file, use "tsave <filename>", and to use it, do "target tfile
2069 ** Circular trace buffer
2071 You can ask the target agent to handle the trace buffer as a
2072 circular buffer, discarding the oldest trace frames to make room for
2073 newer ones, by setting circular-trace-buffer to on. This feature may
2074 not be available for all target agents.
2079 The disassemble command, when invoked with two arguments, now requires
2080 the arguments to be comma-separated.
2083 The info variables command now displays variable definitions. Files
2084 which only declare a variable are not shown.
2087 The source command is now capable of sourcing Python scripts.
2088 This feature is dependent on the debugger being build with Python
2091 Related to this enhancement is also the introduction of a new command
2092 "set script-extension" (see below).
2094 * New commands (for set/show, see "New options" below)
2096 record save [<FILENAME>]
2097 Save a file (in core file format) containing the process record
2098 execution log for replay debugging at a later time.
2100 record restore <FILENAME>
2101 Restore the process record execution log that was saved at an
2102 earlier time, for replay debugging.
2104 add-inferior [-copies <N>] [-exec <FILENAME>]
2107 clone-inferior [-copies <N>] [ID]
2108 Make a new inferior ready to execute the same program another
2109 inferior has loaded.
2114 maint info program-spaces
2115 List the program spaces loaded into GDB.
2117 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2118 show remote interrupt-sequence
2119 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2120 as the sequence to the remote target in order to interrupt the execution.
2121 Ctrl-C is a default. Some system prefers BREAK which is high level of
2122 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2123 Magic SysRq g. It is BREAK signal and character 'g'.
2125 set remote interrupt-on-connect [on | off]
2126 show remote interrupt-on-connect
2127 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2128 remote target when gdb connects to it. This is needed when you debug
2131 set remotebreak [on | off]
2133 Deprecated. Use "set/show remote interrupt-sequence" instead.
2135 tvariable $NAME [ = EXP ]
2136 Create or modify a trace state variable.
2139 List trace state variables and their values.
2141 delete tvariable $NAME ...
2142 Delete one or more trace state variables.
2145 Evaluate the given expressions without collecting anything into the
2146 trace buffer. (Valid in tracepoint actions only.)
2148 ftrace FN / FILE:LINE / *ADDR
2149 Define a fast tracepoint at the given function, line, or address.
2151 * New expression syntax
2153 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2154 GDB now parses 0b101010 identically with 42.
2158 set follow-exec-mode new|same
2159 show follow-exec-mode
2160 Control whether GDB reuses the same inferior across an exec call or
2161 creates a new one. This is useful to be able to restart the old
2162 executable after the inferior having done an exec call.
2164 set default-collect EXPR, ...
2165 show default-collect
2166 Define a list of expressions to be collected at each tracepoint.
2167 This is a useful way to ensure essential items are not overlooked,
2168 such as registers or a critical global variable.
2170 set disconnected-tracing
2171 show disconnected-tracing
2172 If set to 1, the target is instructed to continue tracing if it
2173 loses its connection to GDB. If 0, the target is to stop tracing
2176 set circular-trace-buffer
2177 show circular-trace-buffer
2178 If set to on, the target is instructed to use a circular trace buffer
2179 and discard the oldest trace frames instead of stopping the trace due
2180 to a full trace buffer. If set to off, the trace stops when the buffer
2181 fills up. Some targets may not support this.
2183 set script-extension off|soft|strict
2184 show script-extension
2185 If set to "off", the debugger does not perform any script language
2186 recognition, and all sourced files are assumed to be GDB scripts.
2187 If set to "soft" (the default), files are sourced according to
2188 filename extension, falling back to GDB scripts if the first
2190 If set to "strict", files are sourced according to filename extension.
2192 set ada trust-PAD-over-XVS on|off
2193 show ada trust-PAD-over-XVS
2194 If off, activate a workaround against a bug in the debugging information
2195 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2196 the GCC sources for more information about the GNAT encoding and
2197 PAD types in particular). It is always safe to set this option to
2198 off, but this introduces a slight performance penalty. The default
2201 * Python API Improvements
2203 ** GDB provides the new class gdb.LazyString. This is useful in
2204 some pretty-printing cases. The new method gdb.Value.lazy_string
2205 provides a simple way to create objects of this type.
2207 ** The fields returned by gdb.Type.fields now have an
2208 `is_base_class' attribute.
2210 ** The new method gdb.Type.range returns the range of an array type.
2212 ** The new method gdb.parse_and_eval can be used to parse and
2213 evaluate an expression.
2215 * New remote packets
2218 Define a trace state variable.
2221 Get the current value of a trace state variable.
2224 Set desired tracing behavior upon disconnection.
2227 Set the trace buffer to be linear or circular.
2230 Get data about the tracepoints currently in use.
2234 Process record now works correctly with hardware watchpoints.
2236 Multiple bug fixes have been made to the mips-irix port, making it
2237 much more reliable. In particular:
2238 - Debugging threaded applications is now possible again. Previously,
2239 GDB would hang while starting the program, or while waiting for
2240 the program to stop at a breakpoint.
2241 - Attaching to a running process no longer hangs.
2242 - An error occurring while loading a core file has been fixed.
2243 - Changing the value of the PC register now works again. This fixes
2244 problems observed when using the "jump" command, or when calling
2245 a function from GDB, or even when assigning a new value to $pc.
2246 - With the "finish" and "return" commands, the return value for functions
2247 returning a small array is now correctly printed.
2248 - It is now possible to break on shared library code which gets executed
2249 during a shared library init phase (code executed while executing
2250 their .init section). Previously, the breakpoint would have no effect.
2251 - GDB is now able to backtrace through the signal handler for
2252 non-threaded programs.
2254 PIE (Position Independent Executable) programs debugging is now supported.
2255 This includes debugging execution of PIC (Position Independent Code) shared
2256 libraries although for that, it should be possible to run such libraries as an
2259 *** Changes in GDB 7.0
2261 * GDB now has an interface for JIT compilation. Applications that
2262 dynamically generate code can create symbol files in memory and register
2263 them with GDB. For users, the feature should work transparently, and
2264 for JIT developers, the interface is documented in the GDB manual in the
2265 "JIT Compilation Interface" chapter.
2267 * Tracepoints may now be conditional. The syntax is as for
2268 breakpoints; either an "if" clause appended to the "trace" command,
2269 or the "condition" command is available. GDB sends the condition to
2270 the target for evaluation using the same bytecode format as is used
2271 for tracepoint actions.
2273 * The disassemble command now supports: an optional /r modifier, print the
2274 raw instructions in hex as well as in symbolic form, and an optional /m
2275 modifier to print mixed source+assembly.
2277 * Process record and replay
2279 In a architecture environment that supports ``process record and
2280 replay'', ``process record and replay'' target can record a log of
2281 the process execution, and replay it with both forward and reverse
2284 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2285 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2286 set execution-direction {forward|reverse}, for targets that support
2289 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2290 feature is available with a native GDB running on kernel version
2293 * GDB now has support for multi-byte and wide character sets on the
2294 target. Strings whose character type is wchar_t, char16_t, or
2295 char32_t are now correctly printed. GDB supports wide- and unicode-
2296 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2297 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2298 `printf'. This feature requires iconv to work properly; if your
2299 system does not have a working iconv, GDB can use GNU libiconv. See
2300 the installation instructions for more information.
2302 * GDB now supports automatic retrieval of shared library files from
2303 remote targets. To use this feature, specify a system root that begins
2304 with the `remote:' prefix, either via the `set sysroot' command or via
2305 the `--with-sysroot' configure-time option.
2307 * "info sharedlibrary" now takes an optional regex of libraries to show,
2308 and it now reports if a shared library has no debugging information.
2310 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2311 now complete on file names.
2313 * When completing in expressions, gdb will attempt to limit
2314 completions to allowable structure or union fields, where appropriate.
2315 For instance, consider:
2317 # struct example { int f1; double f2; };
2318 # struct example variable;
2321 If the user types TAB at the end of this command line, the available
2322 completions will be "f1" and "f2".
2324 * Inlined functions are now supported. They show up in backtraces, and
2325 the "step", "next", and "finish" commands handle them automatically.
2327 * GDB now supports the token-splicing (##) and stringification (#)
2328 operators when expanding macros. It also supports variable-arity
2331 * GDB now supports inspecting extra signal information, exported by
2332 the new $_siginfo convenience variable. The feature is currently
2333 implemented on linux ARM, i386 and amd64.
2335 * GDB can now display the VFP floating point registers and NEON vector
2336 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2337 can provide these registers (requires Linux 2.6.30 or later). Remote
2338 and simulator targets may also provide them.
2340 * New remote packets
2343 Search memory for a sequence of bytes.
2346 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2347 operation over reliable transport links. Use of this packet is
2348 controlled by the `set remote noack-packet' command.
2351 Kill the process with the specified process ID. Use this in preference
2352 to `k' when multiprocess protocol extensions are supported.
2355 Obtains additional operating system information
2359 Read or write additional signal information.
2361 * Removed remote protocol undocumented extension
2363 An undocumented extension to the remote protocol's `S' stop reply
2364 packet that permited the stub to pass a process id was removed.
2365 Remote servers should use the `T' stop reply packet instead.
2367 * GDB now supports multiple function calling conventions according to the
2368 DWARF-2 DW_AT_calling_convention function attribute.
2370 * The SH target utilizes the aforementioned change to distinguish between gcc
2371 and Renesas calling convention. It also adds the new CLI commands
2372 `set/show sh calling-convention'.
2374 * GDB can now read compressed debug sections, as produced by GNU gold
2375 with the --compress-debug-sections=zlib flag.
2377 * 64-bit core files are now supported on AIX.
2379 * Thread switching is now supported on Tru64.
2381 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2382 which will be allocated using malloc later in program execution.
2384 * The qXfer:libraries:read remote procotol packet now allows passing a
2385 list of section offsets.
2387 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2388 conditions handling signals delivered during attach or thread creation
2389 have also been fixed.
2391 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2392 From the user's standpoint, all unqualified instances of True and False
2393 are treated as the standard definitions, regardless of context.
2395 * GDB now parses C++ symbol and type names more flexibly. For
2398 template<typename T> class C { };
2401 GDB will now correctly handle all of:
2403 ptype C<char const *>
2404 ptype C<char const*>
2405 ptype C<const char *>
2406 ptype C<const char*>
2408 * New features in the GDB remote stub, gdbserver
2410 - The "--wrapper" command-line argument tells gdbserver to use a
2411 wrapper program to launch programs for debugging.
2413 - On PowerPC and S/390 targets, it is now possible to use a single
2414 gdbserver executable to debug both 32-bit and 64-bit programs.
2415 (This requires gdbserver itself to be built as a 64-bit executable.)
2417 - gdbserver uses the new noack protocol mode for TCP connections to
2418 reduce communications latency, if also supported and enabled in GDB.
2420 - Support for the sparc64-linux-gnu target is now included in
2423 - The amd64-linux build of gdbserver now supports debugging both
2424 32-bit and 64-bit programs.
2426 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2427 now support hardware watchpoints, and will use them automatically
2432 GDB now has support for scripting using Python. Whether this is
2433 available is determined at configure time.
2435 New GDB commands can now be written in Python.
2437 * Ada tasking support
2439 Ada tasks can now be inspected in GDB. The following commands have
2443 Print the list of Ada tasks.
2445 Print detailed information about task number N.
2447 Print the task number of the current task.
2449 Switch the context of debugging to task number N.
2451 * Support for user-defined prefixed commands. The "define" command can
2452 add new commands to existing prefixes, e.g. "target".
2454 * Multi-inferior, multi-process debugging.
2456 GDB now has generalized support for multi-inferior debugging. See
2457 "Debugging Multiple Inferiors" in the manual for more information.
2458 Although availability still depends on target support, the command
2459 set is more uniform now. The GNU/Linux specific multi-forks support
2460 has been migrated to this new framework. This implied some user
2461 visible changes; see "New commands" and also "Removed commands"
2464 * Target descriptions can now describe the target OS ABI. See the
2465 "Target Description Format" section in the user manual for more
2468 * Target descriptions can now describe "compatible" architectures
2469 to indicate that the target can execute applications for a different
2470 architecture in addition to those for the main target architecture.
2471 See the "Target Description Format" section in the user manual for
2474 * Multi-architecture debugging.
2476 GDB now includes general supports for debugging applications on
2477 hybrid systems that use more than one single processor architecture
2478 at the same time. Each such hybrid architecture still requires
2479 specific support to be added. The only hybrid architecture supported
2480 in this version of GDB is the Cell Broadband Engine.
2482 * GDB now supports integrated debugging of Cell/B.E. applications that
2483 use both the PPU and SPU architectures. To enable support for hybrid
2484 Cell/B.E. debugging, you need to configure GDB to support both the
2485 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2486 --enable-targets configure option.
2488 * Non-stop mode debugging.
2490 For some targets, GDB now supports an optional mode of operation in
2491 which you can examine stopped threads while other threads continue
2492 to execute freely. This is referred to as non-stop mode, with the
2493 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2494 section in the user manual for more information.
2496 To be able to support remote non-stop debugging, a remote stub needs
2497 to implement the non-stop mode remote protocol extensions, as
2498 described in the "Remote Non-Stop" section of the user manual. The
2499 GDB remote stub, gdbserver, has been adjusted to support these
2500 extensions on linux targets.
2502 * New commands (for set/show, see "New options" below)
2504 catch syscall [NAME(S) | NUMBER(S)]
2505 Catch system calls. Arguments, which should be names of system
2506 calls or their numbers, mean catch only those syscalls. Without
2507 arguments, every syscall will be caught. When the inferior issues
2508 any of the specified syscalls, GDB will stop and announce the system
2509 call, both when it is called and when its call returns. This
2510 feature is currently available with a native GDB running on the
2511 Linux Kernel, under the following architectures: x86, x86_64,
2512 PowerPC and PowerPC64.
2514 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2516 Search memory for a sequence of bytes.
2518 maint set python print-stack
2519 maint show python print-stack
2520 Show a stack trace when an error is encountered in a Python script.
2523 Invoke CODE by passing it to the Python interpreter.
2528 These allow macros to be defined, undefined, and listed
2532 Show operating system information about processes.
2535 List the inferiors currently under GDB's control.
2538 Switch focus to inferior number NUM.
2541 Detach from inferior number NUM.
2544 Kill inferior number NUM.
2548 set spu stop-on-load
2549 show spu stop-on-load
2550 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2552 set spu auto-flush-cache
2553 show spu auto-flush-cache
2554 Control whether to automatically flush the software-managed cache
2555 during Cell/B.E. debugging.
2557 set sh calling-convention
2558 show sh calling-convention
2559 Control the calling convention used when calling SH target functions.
2562 show debug timestamp
2563 Control display of timestamps with GDB debugging output.
2565 set disassemble-next-line
2566 show disassemble-next-line
2567 Control display of disassembled source lines or instructions when
2570 set remote noack-packet
2571 show remote noack-packet
2572 Set/show the use of remote protocol QStartNoAckMode packet. See above
2573 under "New remote packets."
2575 set remote query-attached-packet
2576 show remote query-attached-packet
2577 Control use of remote protocol `qAttached' (query-attached) packet.
2579 set remote read-siginfo-object
2580 show remote read-siginfo-object
2581 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2584 set remote write-siginfo-object
2585 show remote write-siginfo-object
2586 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2589 set remote reverse-continue
2590 show remote reverse-continue
2591 Control use of remote protocol 'bc' (reverse-continue) packet.
2593 set remote reverse-step
2594 show remote reverse-step
2595 Control use of remote protocol 'bs' (reverse-step) packet.
2597 set displaced-stepping
2598 show displaced-stepping
2599 Control displaced stepping mode. Displaced stepping is a way to
2600 single-step over breakpoints without removing them from the debuggee.
2601 Also known as "out-of-line single-stepping".
2604 show debug displaced
2605 Control display of debugging info for displaced stepping.
2607 maint set internal-error
2608 maint show internal-error
2609 Control what GDB does when an internal error is detected.
2611 maint set internal-warning
2612 maint show internal-warning
2613 Control what GDB does when an internal warning is detected.
2618 Use a wrapper program to launch programs for debugging.
2620 set multiple-symbols (all|ask|cancel)
2621 show multiple-symbols
2622 The value of this variable can be changed to adjust the debugger behavior
2623 when an expression or a breakpoint location contains an ambiguous symbol
2624 name (an overloaded function name, for instance).
2626 set breakpoint always-inserted
2627 show breakpoint always-inserted
2628 Keep breakpoints always inserted in the target, as opposed to inserting
2629 them when resuming the target, and removing them when the target stops.
2630 This option can improve debugger performance on slow remote targets.
2632 set arm fallback-mode (arm|thumb|auto)
2633 show arm fallback-mode
2634 set arm force-mode (arm|thumb|auto)
2636 These commands control how ARM GDB determines whether instructions
2637 are ARM or Thumb. The default for both settings is auto, which uses
2638 the current CPSR value for instructions without symbols; previous
2639 versions of GDB behaved as if "set arm fallback-mode arm".
2641 set disable-randomization
2642 show disable-randomization
2643 Standalone programs run with the virtual address space randomization enabled
2644 by default on some platforms. This option keeps the addresses stable across
2645 multiple debugging sessions.
2649 Control whether other threads are stopped or not when some thread hits
2654 Requests that asynchronous execution is enabled in the target, if available.
2655 In this case, it's possible to resume target in the background, and interact
2656 with GDB while the target is running. "show target-async" displays the
2657 current state of asynchronous execution of the target.
2659 set target-wide-charset
2660 show target-wide-charset
2661 The target-wide-charset is the name of the character set that GDB
2662 uses when printing characters whose type is wchar_t.
2664 set tcp auto-retry (on|off)
2666 set tcp connect-timeout
2667 show tcp connect-timeout
2668 These commands allow GDB to retry failed TCP connections to a remote stub
2669 with a specified timeout period; this is useful if the stub is launched
2670 in parallel with GDB but may not be ready to accept connections immediately.
2672 set libthread-db-search-path
2673 show libthread-db-search-path
2674 Control list of directories which GDB will search for appropriate
2677 set schedule-multiple (on|off)
2678 show schedule-multiple
2679 Allow GDB to resume all threads of all processes or only threads of
2680 the current process.
2684 Use more aggressive caching for accesses to the stack. This improves
2685 performance of remote debugging (particularly backtraces) without
2686 affecting correctness.
2688 set interactive-mode (on|off|auto)
2689 show interactive-mode
2690 Control whether GDB runs in interactive mode (on) or not (off).
2691 When in interactive mode, GDB waits for the user to answer all
2692 queries. Otherwise, GDB does not wait and assumes the default
2693 answer. When set to auto (the default), GDB determines which
2694 mode to use based on the stdin settings.
2699 For program forks, this is replaced by the new more generic `info
2700 inferiors' command. To list checkpoints, you can still use the
2701 `info checkpoints' command, which was an alias for the `info forks'
2705 Replaced by the new `inferior' command. To switch between
2706 checkpoints, you can still use the `restart' command, which was an
2707 alias for the `fork' command.
2710 This is removed, since some targets don't have a notion of
2711 processes. To switch between processes, you can still use the
2712 `inferior' command using GDB's own inferior number.
2715 For program forks, this is replaced by the new more generic `kill
2716 inferior' command. To delete a checkpoint, you can still use the
2717 `delete checkpoint' command, which was an alias for the `delete
2721 For program forks, this is replaced by the new more generic `detach
2722 inferior' command. To detach a checkpoint, you can still use the
2723 `detach checkpoint' command, which was an alias for the `detach
2726 * New native configurations
2728 x86/x86_64 Darwin i[34567]86-*-darwin*
2730 x86_64 MinGW x86_64-*-mingw*
2734 Lattice Mico32 lm32-*
2735 x86 DICOS i[34567]86-*-dicos*
2736 x86_64 DICOS x86_64-*-dicos*
2739 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2740 (mingw32ce) debugging.
2746 These commands were actually not implemented on any target.
2748 *** Changes in GDB 6.8
2750 * New native configurations
2752 NetBSD/hppa hppa*-*netbsd*
2753 Xtensa GNU/Linux xtensa*-*-linux*
2757 NetBSD/hppa hppa*-*-netbsd*
2758 Xtensa GNU/Lunux xtensa*-*-linux*
2760 * Change in command line behavior -- corefiles vs. process ids.
2762 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2763 attaching to process NUMBER fails, GDB no longer attempts to open a
2764 core file named NUMBER. Attaching to a program using the -c option
2765 is no longer supported. Instead, use the '-p' or '--pid' options.
2767 * GDB can now be built as a native debugger for debugging Windows x86
2768 (mingw32) Portable Executable (PE) programs.
2770 * Pending breakpoints no longer change their number when their address
2773 * GDB now supports breakpoints with multiple locations,
2774 including breakpoints on C++ constructors, inside C++ templates,
2775 and in inlined functions.
2777 * GDB's ability to debug optimized code has been improved. GDB more
2778 accurately identifies function bodies and lexical blocks that occupy
2779 more than one contiguous range of addresses.
2781 * Target descriptions can now describe registers for PowerPC.
2783 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2784 registers on PowerPC targets.
2786 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2787 targets even when the libthread_db library is not available.
2789 * The GDB remote stub, gdbserver, now supports the new file transfer
2790 commands (remote put, remote get, and remote delete).
2792 * The GDB remote stub, gdbserver, now supports run and attach in
2793 extended-remote mode.
2795 * hppa*64*-*-hpux11* target broken
2796 The debugger is unable to start a program and fails with the following
2797 error: "Error trying to get information about dynamic linker".
2798 The gdb-6.7 release is also affected.
2800 * GDB now supports the --enable-targets= configure option to allow
2801 building a single GDB executable that supports multiple remote
2802 target architectures.
2804 * GDB now supports debugging C and C++ programs which use the
2805 Decimal Floating Point extension. In addition, the PowerPC target
2806 now has a set of pseudo-registers to inspect decimal float values
2807 stored in two consecutive float registers.
2809 * The -break-insert MI command can optionally create pending
2812 * Improved support for debugging Ada
2813 Many improvements to the Ada language support have been made. These
2815 - Better support for Ada2005 interface types
2816 - Improved handling of arrays and slices in general
2817 - Better support for Taft-amendment types
2818 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2820 - Improved command completion in Ada
2823 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2828 set print frame-arguments (all|scalars|none)
2829 show print frame-arguments
2830 The value of this variable can be changed to control which argument
2831 values should be printed by the debugger when displaying a frame.
2836 Transfer files to and from a remote target, and delete remote files.
2843 Transfer files to and from a remote target, and delete remote files.
2845 * New remote packets
2852 Open, close, read, write, and delete files on the remote system.
2855 Attach to an existing process on the remote system, in extended-remote
2859 Run a new process on the remote system, in extended-remote mode.
2861 *** Changes in GDB 6.7
2863 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2864 bfd, libiberty and opcodes, as revealed by static analysis donated by
2865 Coverity, Inc. (http://scan.coverity.com).
2867 * When looking up multiply-defined global symbols, GDB will now prefer the
2868 symbol definition in the current shared library if it was built using the
2869 -Bsymbolic linker option.
2871 * When the Text User Interface (TUI) is not configured, GDB will now
2872 recognize the -tui command-line option and print a message that the TUI
2875 * The GDB remote stub, gdbserver, now has lower overhead for high
2876 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2878 * GDB for MIPS targets now autodetects whether a remote target provides
2879 32-bit or 64-bit register values.
2881 * Support for C++ member pointers has been improved.
2883 * GDB now understands XML target descriptions, which specify the
2884 target's overall architecture. GDB can read a description from
2885 a local file or over the remote serial protocol.
2887 * Vectors of single-byte data use a new integer type which is not
2888 automatically displayed as character or string data.
2890 * The /s format now works with the print command. It displays
2891 arrays of single-byte integers and pointers to single-byte integers
2894 * Target descriptions can now describe target-specific registers,
2895 for architectures which have implemented the support (currently
2896 only ARM, M68K, and MIPS).
2898 * GDB and the GDB remote stub, gdbserver, now support the XScale
2901 * The GDB remote stub, gdbserver, has been updated to support
2902 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2903 has been rewritten to use the standard GDB remote protocol.
2905 * GDB can now step into C++ functions which are called through thunks.
2907 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2909 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2910 layout. It also supports a TextSeg= and DataSeg= response when only
2911 segment base addresses (rather than offsets) are available.
2913 * The /i format now outputs any trailing branch delay slot instructions
2914 immediately following the last instruction within the count specified.
2916 * The GDB remote protocol "T" stop reply packet now supports a
2917 "library" response. Combined with the new "qXfer:libraries:read"
2918 packet, this response allows GDB to debug shared libraries on targets
2919 where the operating system manages the list of loaded libraries (e.g.
2920 Windows and SymbianOS).
2922 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2923 (DLLs) on Windows and Windows CE targets.
2925 * GDB now supports a faster verification that a .debug file matches its binary
2926 according to its build-id signature, if the signature is present.
2932 Enable or disable hardware flow control (RTS/CTS) on the serial port
2933 when debugging using remote targets.
2935 set mem inaccessible-by-default
2936 show mem inaccessible-by-default
2937 If the target supplies a memory map, for instance via the remote
2938 protocol's "qXfer:memory-map:read" packet, setting this variable
2939 prevents GDB from accessing memory outside the memory map. This
2940 is useful for targets with memory mapped registers or which react
2941 badly to accesses of unmapped address space.
2943 set breakpoint auto-hw
2944 show breakpoint auto-hw
2945 If the target supplies a memory map, for instance via the remote
2946 protocol's "qXfer:memory-map:read" packet, setting this variable
2947 lets GDB use hardware breakpoints automatically for memory regions
2948 where it can not use software breakpoints. This covers both the
2949 "break" command and internal breakpoints used for other commands
2950 including "next" and "finish".
2953 catch exception unhandled
2954 Stop the program execution when Ada exceptions are raised.
2957 Stop the program execution when an Ada assertion failed.
2961 Set an alternate system root for target files. This is a more
2962 general version of "set solib-absolute-prefix", which is now
2963 an alias to "set sysroot".
2966 Provide extended SPU facility status information. This set of
2967 commands is available only when debugging the Cell/B.E. SPU
2970 * New native configurations
2972 OpenBSD/sh sh*-*openbsd*
2975 unset tdesc filename
2977 Use the specified local file as an XML target description, and do
2978 not query the target for its built-in description.
2982 OpenBSD/sh sh*-*-openbsd*
2983 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2984 Toshiba Media Processor mep-elf
2986 * New remote packets
2989 Ignore the specified signals; pass them directly to the debugged program
2990 without stopping other threads or reporting them to GDB.
2992 qXfer:features:read:
2993 Read an XML target description from the target, which describes its
2998 Read or write contents of an spufs file on the target system. These
2999 packets are available only on the Cell/B.E. SPU architecture.
3001 qXfer:libraries:read:
3002 Report the loaded shared libraries. Combined with new "T" packet
3003 response, this packet allows GDB to debug shared libraries on
3004 targets where the operating system manages the list of loaded
3005 libraries (e.g. Windows and SymbianOS).
3009 Support for these obsolete configurations has been removed.
3017 i[34567]86-*-lynxos*
3018 i[34567]86-*-netware*
3019 i[34567]86-*-sco3.2v5*
3020 i[34567]86-*-sco3.2v4*
3022 i[34567]86-*-sysv4.2*
3025 i[34567]86-*-unixware2*
3026 i[34567]86-*-unixware*
3035 * Other removed features
3042 Various m68k-only ROM monitors.
3049 Various Renesas ROM monitors and debugging interfaces for SH and
3054 Support for a Macraigor serial interface to on-chip debugging.
3055 GDB does not directly support the newer parallel or USB
3060 A debug information format. The predecessor to DWARF 2 and
3061 DWARF 3, which are still supported.
3063 Support for the HP aCC compiler on HP-UX/PA-RISC
3065 SOM-encapsulated symbolic debugging information, automatic
3066 invocation of pxdb, and the aCC custom C++ ABI. This does not
3067 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3068 with aCC can still be debugged on an assembly level.
3070 MIPS ".pdr" sections
3072 A MIPS-specific format used to describe stack frame layout
3073 in debugging information.
3077 GDB could work with an older version of Guile to debug
3078 the interpreter and Scheme programs running in it.
3080 set mips stack-arg-size
3081 set mips saved-gpreg-size
3083 Use "set mips abi" to control parameter passing for MIPS.
3085 *** Changes in GDB 6.6
3090 Cell Broadband Engine SPU spu-elf
3092 * GDB can now be configured as a cross-debugger targeting native Windows
3093 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3094 running on a Windows system over TCP/IP to debug Windows programs.
3096 * The GDB remote stub, gdbserver, has been updated to support Windows and
3097 Cygwin debugging. Both single-threaded and multi-threaded programs are
3100 * The "set trust-readonly-sections" command works again. This command was
3101 broken in GDB 6.3, 6.4, and 6.5.
3103 * The "load" command now supports writing to flash memory, if the remote
3104 stub provides the required support.
3106 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3107 longer requires symbolic debug information (e.g. DWARF-2).
3112 unset substitute-path
3113 show substitute-path
3114 Manage a list of substitution rules that GDB uses to rewrite the name
3115 of the directories where the sources are located. This can be useful
3116 for instance when the sources were moved to a different location
3117 between compilation and debugging.
3121 Print each CLI command as it is executed. Each command is prefixed with
3122 a number of `+' symbols representing the nesting depth.
3123 The source command now has a `-v' option to enable the same feature.
3127 The ARM Demon monitor support (RDP protocol, "target rdp").
3129 Kernel Object Display, an embedded debugging feature which only worked with
3130 an obsolete version of Cisco IOS.
3132 The 'set download-write-size' and 'show download-write-size' commands.
3134 * New remote packets
3137 Tell a stub about GDB client features, and request remote target features.
3138 The first feature implemented is PacketSize, which allows the target to
3139 specify the size of packets it can handle - to minimize the number of
3140 packets required and improve performance when connected to a remote
3144 Fetch an OS auxilliary vector from the remote stub. This packet is a
3145 more efficient replacement for qPart:auxv:read.
3147 qXfer:memory-map:read:
3148 Fetch a memory map from the remote stub, including information about
3149 RAM, ROM, and flash memory devices.
3154 Erase and program a flash memory device.
3156 * Removed remote packets
3159 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3160 used it, and only gdbserver implemented it.
3162 *** Changes in GDB 6.5
3166 Renesas M32C/M16C m32c-elf
3168 Morpho Technologies ms1 ms1-elf
3172 init-if-undefined Initialize a convenience variable, but
3173 only if it doesn't already have a value.
3175 The following commands are presently only implemented for native GNU/Linux:
3177 checkpoint Save a snapshot of the program state.
3179 restart <n> Return the program state to a
3180 previously saved state.
3182 info checkpoints List currently saved checkpoints.
3184 delete-checkpoint <n> Delete a previously saved checkpoint.
3186 set|show detach-on-fork Tell gdb whether to detach from a newly
3187 forked process, or to keep debugging it.
3189 info forks List forks of the user program that
3190 are available to be debugged.
3192 fork <n> Switch to debugging one of several
3193 forks of the user program that are
3194 available to be debugged.
3196 delete-fork <n> Delete a fork from the list of forks
3197 that are available to be debugged (and
3198 kill the forked process).
3200 detach-fork <n> Delete a fork from the list of forks
3201 that are available to be debugged (and
3202 allow the process to continue).
3206 Morpho Technologies ms2 ms1-elf
3208 * Improved Windows host support
3210 GDB now builds as a cross debugger hosted on i686-mingw32, including
3211 native console support, and remote communications using either
3212 network sockets or serial ports.
3214 * Improved Modula-2 language support
3216 GDB can now print most types in the Modula-2 syntax. This includes:
3217 basic types, set types, record types, enumerated types, range types,
3218 pointer types and ARRAY types. Procedure var parameters are correctly
3219 printed and hexadecimal addresses and character constants are also
3220 written in the Modula-2 syntax. Best results can be obtained by using
3221 GNU Modula-2 together with the -gdwarf-2 command line option.
3225 The ARM rdi-share module.
3227 The Netware NLM debug server.
3229 *** Changes in GDB 6.4
3231 * New native configurations
3233 OpenBSD/arm arm*-*-openbsd*
3234 OpenBSD/mips64 mips64-*-openbsd*
3238 Morpho Technologies ms1 ms1-elf
3240 * New command line options
3242 --batch-silent As for --batch, but totally silent.
3243 --return-child-result The debugger will exist with the same value
3244 the child (debugged) program exited with.
3245 --eval-command COMMAND, -ex COMMAND
3246 Execute a single GDB CLI command. This may be
3247 specified multiple times and in conjunction
3248 with the --command (-x) option.
3250 * Deprecated commands removed
3252 The following commands, that were deprecated in 2000, have been
3256 set|show arm disassembly-flavor set|show arm disassembler
3257 othernames set arm disassembler
3258 set|show remotedebug set|show debug remote
3259 set|show archdebug set|show debug arch
3260 set|show eventdebug set|show debug event
3263 * New BSD user-level threads support
3265 It is now possible to debug programs using the user-level threads
3266 library on OpenBSD and FreeBSD. Currently supported (target)
3269 FreeBSD/amd64 x86_64-*-freebsd*
3270 FreeBSD/i386 i386-*-freebsd*
3271 OpenBSD/i386 i386-*-openbsd*
3273 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3274 are not yet supported.
3276 * New support for Matsushita MN10300 w/sim added
3277 (Work in progress). mn10300-elf.
3279 * REMOVED configurations and files
3281 VxWorks and the XDR protocol *-*-vxworks
3282 Motorola MCORE mcore-*-*
3283 National Semiconductor NS32000 ns32k-*-*
3285 * New "set print array-indexes" command
3287 After turning this setting "on", GDB prints the index of each element
3288 when displaying arrays. The default is "off" to preserve the previous
3291 * VAX floating point support
3293 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3295 * User-defined command support
3297 In addition to using $arg0..$arg9 for argument passing, it is now possible
3298 to use $argc to determine now many arguments have been passed. See the
3299 section on user-defined commands in the user manual for more information.
3301 *** Changes in GDB 6.3:
3303 * New command line option
3305 GDB now accepts -l followed by a number to set the timeout for remote
3308 * GDB works with GCC -feliminate-dwarf2-dups
3310 GDB now supports a more compact representation of DWARF-2 debug
3311 information using DW_FORM_ref_addr references. These are produced
3312 by GCC with the option -feliminate-dwarf2-dups and also by some
3313 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3314 to use -feliminate-dwarf2-dups.
3316 * Internationalization
3318 When supported by the host system, GDB will be built with
3319 internationalization (libintl). The task of marking up the sources is
3320 continued, we're looking forward to our first translation.
3324 Initial support for debugging programs compiled with the GNAT
3325 implementation of the Ada programming language has been integrated
3326 into GDB. In this release, support is limited to expression evaluation.
3328 * New native configurations
3330 GNU/Linux/m32r m32r-*-linux-gnu
3334 GDB's remote protocol now includes support for the 'p' packet. This
3335 packet is used to fetch individual registers from a remote inferior.
3337 * END-OF-LIFE registers[] compatibility module
3339 GDB's internal register infrastructure has been completely rewritten.
3340 The new infrastructure making possible the implementation of key new
3341 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3344 GDB 6.3 will be the last release to include the the registers[]
3345 compatibility module that allowed out-of-date configurations to
3346 continue to work. This change directly impacts the following
3356 powerpc bdm protocol
3358 Unless there is activity to revive these configurations, they will be
3359 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3361 * OBSOLETE configurations and files
3363 Configurations that have been declared obsolete in this release have
3364 been commented out. Unless there is activity to revive these
3365 configurations, the next release of GDB will have their sources
3366 permanently REMOVED.
3375 *** Changes in GDB 6.2.1:
3377 * MIPS `break main; run' gave an heuristic-fence-post warning
3379 When attempting to run even a simple program, a warning about
3380 heuristic-fence-post being hit would be reported. This problem has
3383 * MIPS IRIX 'long double' crashed GDB
3385 When examining a long double variable, GDB would get a segmentation
3386 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3387 IRIX long double values).
3391 A bug in the VAX stack code was causing problems with the "next"
3392 command. This problem has been fixed.
3394 *** Changes in GDB 6.2:
3396 * Fix for ``many threads''
3398 On GNU/Linux systems that use the NPTL threads library, a program
3399 rapidly creating and deleting threads would confuse GDB leading to the
3402 ptrace: No such process.
3403 thread_db_get_info: cannot get thread info: generic error
3405 This problem has been fixed.
3407 * "-async" and "-noasync" options removed.
3409 Support for the broken "-noasync" option has been removed (it caused
3412 * New ``start'' command.
3414 This command runs the program until the begining of the main procedure.
3416 * New BSD Kernel Data Access Library (libkvm) interface
3418 Using ``target kvm'' it is now possible to debug kernel core dumps and
3419 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3420 platforms. Currently supported (native-only) configurations are:
3422 FreeBSD/amd64 x86_64-*-freebsd*
3423 FreeBSD/i386 i?86-*-freebsd*
3424 NetBSD/i386 i?86-*-netbsd*
3425 NetBSD/m68k m68*-*-netbsd*
3426 NetBSD/sparc sparc-*-netbsd*
3427 OpenBSD/amd64 x86_64-*-openbsd*
3428 OpenBSD/i386 i?86-*-openbsd*
3429 OpenBSD/m68k m68*-openbsd*
3430 OpenBSD/sparc sparc-*-openbsd*
3432 * Signal trampoline code overhauled
3434 Many generic problems with GDB's signal handling code have been fixed.
3435 These include: backtraces through non-contiguous stacks; recognition
3436 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3437 call; backtrace through a signal trampoline; step into and out of
3438 signal handlers; and single-stepping in the signal trampoline.
3440 Please note that kernel bugs are a limiting factor here. These
3441 features have been shown to work on an s390 GNU/Linux system that
3442 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3444 * Cygwin support for DWARF 2 added.
3446 * New native configurations
3448 GNU/Linux/hppa hppa*-*-linux*
3449 OpenBSD/hppa hppa*-*-openbsd*
3450 OpenBSD/m68k m68*-*-openbsd*
3451 OpenBSD/m88k m88*-*-openbsd*
3452 OpenBSD/powerpc powerpc-*-openbsd*
3453 NetBSD/vax vax-*-netbsd*
3454 OpenBSD/vax vax-*-openbsd*
3456 * END-OF-LIFE frame compatibility module
3458 GDB's internal frame infrastructure has been completely rewritten.
3459 The new infrastructure making it possible to support key new features
3460 including DWARF 2 Call Frame Information. To aid in the task of
3461 migrating old configurations to this new infrastructure, a
3462 compatibility module, that allowed old configurations to continue to
3463 work, was also included.
3465 GDB 6.2 will be the last release to include this frame compatibility
3466 module. This change directly impacts the following configurations:
3476 Unless there is activity to revive these configurations, they will be
3477 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3479 * REMOVED configurations and files
3481 Sun 3, running SunOS 3 m68*-*-sunos3*
3482 Sun 3, running SunOS 4 m68*-*-sunos4*
3483 Sun 2, running SunOS 3 m68000-*-sunos3*
3484 Sun 2, running SunOS 4 m68000-*-sunos4*
3485 Motorola 680x0 running LynxOS m68*-*-lynxos*
3486 AT&T 3b1/Unix pc m68*-att-*
3487 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3488 decstation mips-dec-* mips-little-*
3489 riscos mips-*-riscos* mips-*-sysv*
3490 sonymips mips-sony-*
3491 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3493 *** Changes in GDB 6.1.1:
3495 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3497 The TUI (Text-mode User Interface) is now built as part of a default
3498 GDB configuration. It is enabled by either selecting the TUI with the
3499 command line option "-i=tui" or by running the separate "gdbtui"
3500 program. For more information on the TUI, see the manual "Debugging
3503 * Pending breakpoint support (also included in GDB 6.1)
3505 Support has been added to allow you to specify breakpoints in shared
3506 libraries that have not yet been loaded. If a breakpoint location
3507 cannot be found, and the "breakpoint pending" option is set to auto,
3508 GDB queries you if you wish to make the breakpoint pending on a future
3509 shared-library load. If and when GDB resolves the breakpoint symbol,
3510 the pending breakpoint is removed as one or more regular breakpoints
3513 Pending breakpoints are very useful for GCJ Java debugging.
3515 * Fixed ISO-C build problems
3517 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3518 non ISO-C code that stopped them being built using a more strict ISO-C
3519 compiler (e.g., IBM's C compiler).
3521 * Fixed build problem on IRIX 5
3523 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3524 wasn't able to compile compile on an IRIX 5 system.
3526 * Added execute permission to gdb/gdbserver/configure
3528 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3529 permission. This bug would cause configure to fail on a number of
3530 systems (Solaris, IRIX). Ref: server/519.
3532 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3534 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3535 has been updated to use constant array sizes.
3537 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3539 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3540 its generated DWARF Call Frame Info. This encoding was causing GDB to
3541 panic, that panic has been fixed. Ref: gdb/1628.
3543 * Fixed a problem when examining parameters in shared library code.
3545 When examining parameters in optimized shared library code generated
3546 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3547 not available''. GDB now correctly displays the variable's value.
3549 *** Changes in GDB 6.1:
3551 * Removed --with-mmalloc
3553 Support for the mmalloc memory manager has been removed, as it
3554 conflicted with the internal gdb byte cache.
3556 * Changes in AMD64 configurations
3558 The AMD64 target now includes the %cs and %ss registers. As a result
3559 the AMD64 remote protocol has changed; this affects the floating-point
3560 and SSE registers. If you rely on those registers for your debugging,
3561 you should upgrade gdbserver on the remote side.
3563 * Revised SPARC target
3565 The SPARC target has been completely revised, incorporating the
3566 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3567 support for LynxOS and SunOS 4 has been dropped. Calling functions
3568 from within GDB on operating systems with a non-executable stack
3569 (Solaris, OpenBSD) now works.
3573 GDB has a new C++ demangler which does a better job on the mangled
3574 names generated by current versions of g++. It also runs faster, so
3575 with this and other changes gdb should now start faster on large C++
3578 * DWARF 2 Location Expressions
3580 GDB support for location expressions has been extended to support function
3581 arguments and frame bases. Older versions of GDB could crash when they
3584 * C++ nested types and namespaces
3586 GDB's support for nested types and namespaces in C++ has been
3587 improved, especially if you use the DWARF 2 debugging format. (This
3588 is the default for recent versions of GCC on most platforms.)
3589 Specifically, if you have a class "Inner" defined within a class or
3590 namespace "Outer", then GDB realizes that the class's name is
3591 "Outer::Inner", not simply "Inner". This should greatly reduce the
3592 frequency of complaints about not finding RTTI symbols. In addition,
3593 if you are stopped at inside of a function defined within a namespace,
3594 GDB modifies its name lookup accordingly.
3596 * New native configurations
3598 NetBSD/amd64 x86_64-*-netbsd*
3599 OpenBSD/amd64 x86_64-*-openbsd*
3600 OpenBSD/alpha alpha*-*-openbsd*
3601 OpenBSD/sparc sparc-*-openbsd*
3602 OpenBSD/sparc64 sparc64-*-openbsd*
3604 * New debugging protocols
3606 M32R with SDI protocol m32r-*-elf*
3608 * "set prompt-escape-char" command deleted.
3610 The command "set prompt-escape-char" has been deleted. This command,
3611 and its very obscure effet on GDB's prompt, was never documented,
3612 tested, nor mentioned in the NEWS file.
3614 * OBSOLETE configurations and files
3616 Configurations that have been declared obsolete in this release have
3617 been commented out. Unless there is activity to revive these
3618 configurations, the next release of GDB will have their sources
3619 permanently REMOVED.
3621 Sun 3, running SunOS 3 m68*-*-sunos3*
3622 Sun 3, running SunOS 4 m68*-*-sunos4*
3623 Sun 2, running SunOS 3 m68000-*-sunos3*
3624 Sun 2, running SunOS 4 m68000-*-sunos4*
3625 Motorola 680x0 running LynxOS m68*-*-lynxos*
3626 AT&T 3b1/Unix pc m68*-att-*
3627 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3628 decstation mips-dec-* mips-little-*
3629 riscos mips-*-riscos* mips-*-sysv*
3630 sonymips mips-sony-*
3631 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3633 * REMOVED configurations and files
3635 SGI Irix-4.x mips-sgi-irix4 or iris4
3636 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3637 Z8000 simulator z8k-zilog-none or z8ksim
3638 Matsushita MN10200 w/simulator mn10200-*-*
3639 H8/500 simulator h8500-hitachi-hms or h8500hms
3640 HP/PA running BSD hppa*-*-bsd*
3641 HP/PA running OSF/1 hppa*-*-osf*
3642 HP/PA Pro target hppa*-*-pro*
3643 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3644 386BSD i[3456]86-*-bsd*
3645 Sequent family i[3456]86-sequent-sysv4*
3646 i[3456]86-sequent-sysv*
3647 i[3456]86-sequent-bsd*
3648 SPARC running LynxOS sparc-*-lynxos*
3649 SPARC running SunOS 4 sparc-*-sunos4*
3650 Tsqware Sparclet sparclet-*-*
3651 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3653 *** Changes in GDB 6.0:
3657 Support for debugging the Objective-C programming language has been
3658 integrated into GDB.
3660 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3662 DWARF 2's Call Frame Information makes available compiler generated
3663 information that more exactly describes the program's run-time stack.
3664 By using this information, GDB is able to provide more robust stack
3667 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3668 have been updated to use a new backtrace mechanism which includes
3669 DWARF 2 CFI support.
3673 GDB's remote protocol has been extended to include support for hosted
3674 file I/O (where the remote target uses GDB's file system). See GDB's
3675 remote protocol documentation for details.
3677 * All targets using the new architecture framework.
3679 All of GDB's targets have been updated to use the new internal
3680 architecture framework. The way is now open for future GDB releases
3681 to include cross-architecture native debugging support (i386 on amd64,
3684 * GNU/Linux's Thread Local Storage (TLS)
3686 GDB now includes support for for the GNU/Linux implementation of
3687 per-thread variables.
3689 * GNU/Linux's Native POSIX Thread Library (NPTL)
3691 GDB's thread code has been updated to work with either the new
3692 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3694 * Separate debug info.
3696 GDB, in conjunction with BINUTILS, now supports a mechanism for
3697 automatically loading debug information from a separate file. Instead
3698 of shipping full debug and non-debug versions of system libraries,
3699 system integrators can now instead ship just the stripped libraries
3700 and optional debug files.
3702 * DWARF 2 Location Expressions
3704 DWARF 2 Location Expressions allow the compiler to more completely
3705 describe the location of variables (even in optimized code) to the
3708 GDB now includes preliminary support for location expressions (support
3709 for DW_OP_piece is still missing).
3713 A number of long standing bugs that caused GDB to die while starting a
3714 Java application have been fixed. GDB's Java support is now
3715 considered "useable".
3717 * GNU/Linux support for fork, vfork, and exec.
3719 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3720 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3723 * GDB supports logging output to a file
3725 There are two new commands, "set logging" and "show logging", which can be
3726 used to capture GDB's output to a file.
3728 * The meaning of "detach" has changed for gdbserver
3730 The "detach" command will now resume the application, as documented. To
3731 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3734 * d10v, m68hc11 `regs' command deprecated
3736 The `info registers' command has been updated so that it displays the
3737 registers using a format identical to the old `regs' command.
3741 A new command, "maint set profile on/off", has been added. This command can
3742 be used to enable or disable profiling while running GDB, to profile a
3743 session or a set of commands. In addition there is a new configure switch,
3744 "--enable-profiling", which will cause GDB to be compiled with profiling
3745 data, for more informative profiling results.
3747 * Default MI syntax changed to "mi2".
3749 The default MI (machine interface) syntax, enabled by the command line
3750 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3751 "mi1", can be enabled by specifying the option "-i=mi1".
3753 Support for the original "mi0" syntax (included in GDB 5.0) has been
3756 Fix for gdb/192: removed extraneous space when displaying frame level.
3757 Fix for gdb/672: update changelist is now output in mi list format.
3758 Fix for gdb/702: a -var-assign that updates the value now shows up
3759 in a subsequent -var-update.
3761 * New native configurations.
3763 FreeBSD/amd64 x86_64-*-freebsd*
3765 * Multi-arched targets.
3767 HP/PA HPUX11 hppa*-*-hpux*
3768 Renesas M32R/D w/simulator m32r-*-elf*
3770 * OBSOLETE configurations and files
3772 Configurations that have been declared obsolete in this release have
3773 been commented out. Unless there is activity to revive these
3774 configurations, the next release of GDB will have their sources
3775 permanently REMOVED.
3777 Z8000 simulator z8k-zilog-none or z8ksim
3778 Matsushita MN10200 w/simulator mn10200-*-*
3779 H8/500 simulator h8500-hitachi-hms or h8500hms
3780 HP/PA running BSD hppa*-*-bsd*
3781 HP/PA running OSF/1 hppa*-*-osf*
3782 HP/PA Pro target hppa*-*-pro*
3783 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3784 Sequent family i[3456]86-sequent-sysv4*
3785 i[3456]86-sequent-sysv*
3786 i[3456]86-sequent-bsd*
3787 Tsqware Sparclet sparclet-*-*
3788 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3790 * REMOVED configurations and files
3793 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3794 IBM AIX PS/2 i[3456]86-*-aix
3795 i386 running Mach 3.0 i[3456]86-*-mach3*
3796 i386 running Mach i[3456]86-*-mach*
3797 i386 running OSF/1 i[3456]86-*osf1mk*
3798 HP/Apollo 68k Family m68*-apollo*-sysv*,
3800 m68*-hp-bsd*, m68*-hp-hpux*
3801 Argonaut Risc Chip (ARC) arc-*-*
3802 Mitsubishi D30V d30v-*-*
3803 Fujitsu FR30 fr30-*-elf*
3804 OS/9000 i[34]86-*-os9k
3805 I960 with MON960 i960-*-coff
3807 * MIPS $fp behavior changed
3809 The convenience variable $fp, for the MIPS, now consistently returns
3810 the address of the current frame's base. Previously, depending on the
3811 context, $fp could refer to either $sp or the current frame's base
3812 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3813 The GNU Source-Level Debugger''.
3815 *** Changes in GDB 5.3:
3817 * GNU/Linux shared library multi-threaded performance improved.
3819 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3820 `/proc', in preference to `ptrace' for memory reads. This may result
3821 in an improvement in the start-up time of multi-threaded, shared
3822 library applications when run under GDB. One GDB user writes: ``loads
3823 shared libs like mad''.
3825 * ``gdbserver'' now supports multi-threaded applications on some targets
3827 Support for debugging multi-threaded applications which use
3828 the GNU/Linux LinuxThreads package has been added for
3829 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3830 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3832 * GDB now supports C/C++ preprocessor macros.
3834 GDB now expands preprocessor macro invocations in C/C++ expressions,
3835 and provides various commands for showing macro definitions and how
3838 The new command `macro expand EXPRESSION' expands any macro
3839 invocations in expression, and shows the result.
3841 The new command `show macro MACRO-NAME' shows the definition of the
3842 macro named MACRO-NAME, and where it was defined.
3844 Most compilers don't include information about macros in the debugging
3845 information by default. In GCC 3.1, for example, you need to compile
3846 your program with the options `-gdwarf-2 -g3'. If the macro
3847 information is present in the executable, GDB will read it.
3849 * Multi-arched targets.
3851 DEC Alpha (partial) alpha*-*-*
3852 DEC VAX (partial) vax-*-*
3854 National Semiconductor NS32000 (partial) ns32k-*-*
3855 Motorola 68000 (partial) m68k-*-*
3856 Motorola MCORE mcore-*-*
3860 Fujitsu FRV architecture added by Red Hat frv*-*-*
3863 * New native configurations
3865 Alpha NetBSD alpha*-*-netbsd*
3866 SH NetBSD sh*-*-netbsdelf*
3867 MIPS NetBSD mips*-*-netbsd*
3868 UltraSPARC NetBSD sparc64-*-netbsd*
3870 * OBSOLETE configurations and files
3872 Configurations that have been declared obsolete in this release have
3873 been commented out. Unless there is activity to revive these
3874 configurations, the next release of GDB will have their sources
3875 permanently REMOVED.
3877 Mitsubishi D30V d30v-*-*
3878 OS/9000 i[34]86-*-os9k
3879 IBM AIX PS/2 i[3456]86-*-aix
3880 Fujitsu FR30 fr30-*-elf*
3881 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3882 Argonaut Risc Chip (ARC) arc-*-*
3883 i386 running Mach 3.0 i[3456]86-*-mach3*
3884 i386 running Mach i[3456]86-*-mach*
3885 i386 running OSF/1 i[3456]86-*osf1mk*
3886 HP/Apollo 68k Family m68*-apollo*-sysv*,
3888 m68*-hp-bsd*, m68*-hp-hpux*
3889 I960 with MON960 i960-*-coff
3891 * OBSOLETE languages
3893 CHILL, a Pascal like language used by telecommunications companies.
3895 * REMOVED configurations and files
3897 AMD 29k family via UDI a29k-amd-udi, udi29k
3898 A29K VxWorks a29k-*-vxworks
3899 AMD 29000 embedded, using EBMON a29k-none-none
3900 AMD 29000 embedded with COFF a29k-none-coff
3901 AMD 29000 embedded with a.out a29k-none-aout
3903 testsuite/gdb.hp/gdb.threads-hp/ directory
3905 * New command "set max-user-call-depth <nnn>"
3907 This command allows the user to limit the call depth of user-defined
3908 commands. The default is 1024.
3910 * Changes in FreeBSD/i386 native debugging.
3912 Support for the "generate-core-file" has been added.
3914 * New commands "dump", "append", and "restore".
3916 These commands allow data to be copied from target memory
3917 to a bfd-format or binary file (dump and append), and back
3918 from a file into memory (restore).
3920 * Improved "next/step" support on multi-processor Alpha Tru64.
3922 The previous single-step mechanism could cause unpredictable problems,
3923 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3924 of a software single-step mechanism prevents this.
3926 *** Changes in GDB 5.2.1:
3934 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3935 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3936 Fix, by Joel Brobecker imported from mainline.
3938 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3939 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3940 Fix, by Fred Fish, imported from mainline.
3942 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3943 Surprisingly enough, it works now.
3944 By Michal Ludvig, imported from mainline.
3946 i386 hardware watchpoint support:
3947 avoid misses on second run for some targets.
3948 By Pierre Muller, imported from mainline.
3950 *** Changes in GDB 5.2:
3952 * New command "set trust-readonly-sections on[off]".
3954 This command is a hint that tells gdb that read-only sections
3955 really are read-only (ie. that their contents will not change).
3956 In this mode, gdb will go to the object file rather than the
3957 target to read memory from read-only sections (such as ".text").
3958 This can be a significant performance improvement on some
3959 (notably embedded) targets.
3961 * New command "generate-core-file" (or "gcore").
3963 This new gdb command allows the user to drop a core file of the child
3964 process state at any time. So far it's been implemented only for
3965 GNU/Linux and Solaris, but should be relatively easily ported to other
3966 hosts. Argument is core file name (defaults to core.<pid>).
3968 * New command line option
3970 GDB now accepts --pid or -p followed by a process id.
3972 * Change in command line behavior -- corefiles vs. process ids.
3974 There is a subtle behavior in the way in which GDB handles
3975 command line arguments. The first non-flag argument is always
3976 a program to debug, but the second non-flag argument may either
3977 be a corefile or a process id. Previously, GDB would attempt to
3978 open the second argument as a corefile, and if that failed, would
3979 issue a superfluous error message and then attempt to attach it as
3980 a process. Now, if the second argument begins with a non-digit,
3981 it will be treated as a corefile. If it begins with a digit,
3982 GDB will attempt to attach it as a process, and if no such process
3983 is found, will then attempt to open it as a corefile.
3985 * Changes in ARM configurations.
3987 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3988 configuration is fully multi-arch.
3990 * New native configurations
3992 ARM NetBSD arm*-*-netbsd*
3993 x86 OpenBSD i[3456]86-*-openbsd*
3994 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3995 Sparc64 running FreeBSD sparc64-*-freebsd*
3999 Sanyo XStormy16 xstormy16-elf
4001 * OBSOLETE configurations and files
4003 Configurations that have been declared obsolete in this release have
4004 been commented out. Unless there is activity to revive these
4005 configurations, the next release of GDB will have their sources
4006 permanently REMOVED.
4008 AMD 29k family via UDI a29k-amd-udi, udi29k
4009 A29K VxWorks a29k-*-vxworks
4010 AMD 29000 embedded, using EBMON a29k-none-none
4011 AMD 29000 embedded with COFF a29k-none-coff
4012 AMD 29000 embedded with a.out a29k-none-aout
4014 testsuite/gdb.hp/gdb.threads-hp/ directory
4016 * REMOVED configurations and files
4018 TI TMS320C80 tic80-*-*
4020 PowerPC Solaris powerpcle-*-solaris*
4021 PowerPC Windows NT powerpcle-*-cygwin32
4022 PowerPC Netware powerpc-*-netware*
4023 Harris/CXUX m88k m88*-harris-cxux*
4024 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4025 ns32k-utek-sysv* ns32k-utek-*
4026 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4027 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4028 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4029 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4030 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4032 * Changes to command line processing
4034 The new `--args' feature can be used to specify command-line arguments
4035 for the inferior from gdb's command line.
4037 * Changes to key bindings
4039 There is a new `operate-and-get-next' function bound to `C-o'.
4041 *** Changes in GDB 5.1.1
4043 Fix compile problem on DJGPP.
4045 Fix a problem with floating-point registers on the i386 being
4048 Fix to stop GDB crashing on .debug_str debug info.
4050 Numerous documentation fixes.
4052 Numerous testsuite fixes.
4054 *** Changes in GDB 5.1:
4056 * New native configurations
4058 Alpha FreeBSD alpha*-*-freebsd*
4059 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4060 MIPS GNU/Linux mips*-*-linux*
4061 MIPS SGI Irix 6.x mips*-sgi-irix6*
4062 ia64 AIX ia64-*-aix*
4063 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4067 Motorola 68HC11 and 68HC12 m68hc11-elf
4069 UltraSparc running GNU/Linux sparc64-*-linux*
4071 * OBSOLETE configurations and files
4073 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4074 Harris/CXUX m88k m88*-harris-cxux*
4075 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4076 ns32k-utek-sysv* ns32k-utek-*
4077 TI TMS320C80 tic80-*-*
4079 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4080 PowerPC Solaris powerpcle-*-solaris*
4081 PowerPC Windows NT powerpcle-*-cygwin32
4082 PowerPC Netware powerpc-*-netware*
4083 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4084 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4085 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4086 Apple Macintosh (MPW) host N/A
4088 stuff.c (Program to stuff files into a specially prepared space in kdb)
4089 kdb-start.c (Main loop for the standalone kernel debugger)
4091 Configurations that have been declared obsolete in this release have
4092 been commented out. Unless there is activity to revive these
4093 configurations, the next release of GDB will have their sources
4094 permanently REMOVED.
4096 * REMOVED configurations and files
4098 Altos 3068 m68*-altos-*
4099 Convex c1-*-*, c2-*-*
4101 ARM RISCix arm-*-* (as host)
4105 * GDB has been converted to ISO C.
4107 GDB's source code has been converted to ISO C. In particular, the
4108 sources are fully protoized, and rely on standard headers being
4113 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4115 * The MI enabled by default.
4117 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4118 revised and enabled by default. Packages which use GDB as a debugging
4119 engine behind a UI or another front end are encouraged to switch to
4120 using the GDB/MI interface, instead of the old annotations interface
4121 which is now deprecated.
4123 * Support for debugging Pascal programs.
4125 GDB now includes support for debugging Pascal programs. The following
4126 main features are supported:
4128 - Pascal-specific data types such as sets;
4130 - automatic recognition of Pascal sources based on file-name
4133 - Pascal-style display of data types, variables, and functions;
4135 - a Pascal expression parser.
4137 However, some important features are not yet supported.
4139 - Pascal string operations are not supported at all;
4141 - there are some problems with boolean types;
4143 - Pascal type hexadecimal constants are not supported
4144 because they conflict with the internal variables format;
4146 - support for Pascal objects and classes is not full yet;
4148 - unlike Pascal, GDB is case-sensitive for symbol names.
4150 * Changes in completion.
4152 Commands such as `shell', `run' and `set args', which pass arguments
4153 to inferior programs, now complete on file names, similar to what
4154 users expect at the shell prompt.
4156 Commands which accept locations, such as `disassemble', `print',
4157 `breakpoint', `until', etc. now complete on filenames as well as
4158 program symbols. Thus, if you type "break foob TAB", and the source
4159 files linked into the programs include `foobar.c', that file name will
4160 be one of the candidates for completion. However, file names are not
4161 considered for completion after you typed a colon that delimits a file
4162 name from a name of a function in that file, as in "break foo.c:bar".
4164 `set demangle-style' completes on available demangling styles.
4166 * New platform-independent commands:
4168 It is now possible to define a post-hook for a command as well as a
4169 hook that runs before the command. For more details, see the
4170 documentation of `hookpost' in the GDB manual.
4172 * Changes in GNU/Linux native debugging.
4174 Support for debugging multi-threaded programs has been completely
4175 revised for all platforms except m68k and sparc. You can now debug as
4176 many threads as your system allows you to have.
4178 Attach/detach is supported for multi-threaded programs.
4180 Support for SSE registers was added for x86. This doesn't work for
4181 multi-threaded programs though.
4183 * Changes in MIPS configurations.
4185 Multi-arch support is enabled for all MIPS configurations.
4187 GDB can now be built as native debugger on SGI Irix 6.x systems for
4188 debugging n32 executables. (Debugging 64-bit executables is not yet
4191 * Unified support for hardware watchpoints in all x86 configurations.
4193 Most (if not all) native x86 configurations support hardware-assisted
4194 breakpoints and watchpoints in a unified manner. This support
4195 implements debug register sharing between watchpoints, which allows to
4196 put a virtually infinite number of watchpoints on the same address,
4197 and also supports watching regions up to 16 bytes with several debug
4200 The new maintenance command `maintenance show-debug-regs' toggles
4201 debugging print-outs in functions that insert, remove, and test
4202 watchpoints and hardware breakpoints.
4204 * Changes in the DJGPP native configuration.
4206 New command ``info dos sysinfo'' displays assorted information about
4207 the CPU, OS, memory, and DPMI server.
4209 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4210 display information about segment descriptors stored in GDT, LDT, and
4213 New commands ``info dos pde'' and ``info dos pte'' display entries
4214 from Page Directory and Page Tables (for now works with CWSDPMI only).
4215 New command ``info dos address-pte'' displays the Page Table entry for
4216 a given linear address.
4218 GDB can now pass command lines longer than 126 characters to the
4219 program being debugged (requires an update to the libdbg.a library
4220 which is part of the DJGPP development kit).
4222 DWARF2 debug info is now supported.
4224 It is now possible to `step' and `next' through calls to `longjmp'.
4226 * Changes in documentation.
4228 All GDB documentation was converted to GFDL, the GNU Free
4229 Documentation License.
4231 Tracepoints-related commands are now fully documented in the GDB
4234 TUI, the Text-mode User Interface, is now documented in the manual.
4236 Tracepoints-related commands are now fully documented in the GDB
4239 The "GDB Internals" manual now has an index. It also includes
4240 documentation of `ui_out' functions, GDB coding standards, x86
4241 hardware watchpoints, and memory region attributes.
4243 * GDB's version number moved to ``version.in''
4245 The Makefile variable VERSION has been replaced by the file
4246 ``version.in''. People creating GDB distributions should update the
4247 contents of this file.
4251 GUD support is now a standard part of the EMACS distribution.
4253 *** Changes in GDB 5.0:
4255 * Improved support for debugging FP programs on x86 targets
4257 Unified and much-improved support for debugging floating-point
4258 programs on all x86 targets. In particular, ``info float'' now
4259 displays the FP registers in the same format on all x86 targets, with
4260 greater level of detail.
4262 * Improvements and bugfixes in hardware-assisted watchpoints
4264 It is now possible to watch array elements, struct members, and
4265 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4266 on x86 targets no longer erroneously trigger when the address is
4269 * Improvements in the native DJGPP version of GDB
4271 The distribution now includes all the scripts and auxiliary files
4272 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4273 machines ``out of the box''.
4275 The DJGPP version can now debug programs that use signals. It is
4276 possible to catch signals that happened in the debuggee, deliver
4277 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4278 would kill the program being debugged.) Programs that hook hardware
4279 interrupts (keyboard, timer, etc.) can also be debugged.
4281 It is now possible to debug DJGPP programs that redirect their
4282 standard handles or switch them to raw (as opposed to cooked) mode, or
4283 even close them. The command ``run < foo > bar'' works as expected,
4284 and ``info terminal'' reports useful information about the debuggee's
4285 terminal, including raw/cooked mode, redirection, etc.
4287 The DJGPP version now uses termios functions for console I/O, which
4288 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4291 DOS-style file names with drive letters are now fully supported by
4294 It is now possible to debug DJGPP programs that switch their working
4295 directory. It is also possible to rerun the debuggee any number of
4296 times without restarting GDB; thus, you can use the same setup,
4297 breakpoints, etc. for many debugging sessions.
4299 * New native configurations
4301 ARM GNU/Linux arm*-*-linux*
4302 PowerPC GNU/Linux powerpc-*-linux*
4306 Motorola MCore mcore-*-*
4307 x86 VxWorks i[3456]86-*-vxworks*
4308 PowerPC VxWorks powerpc-*-vxworks*
4309 TI TMS320C80 tic80-*-*
4311 * OBSOLETE configurations
4313 Altos 3068 m68*-altos-*
4314 Convex c1-*-*, c2-*-*
4316 ARM RISCix arm-*-* (as host)
4319 Configurations that have been declared obsolete will be commented out,
4320 but the code will be left in place. If there is no activity to revive
4321 these configurations before the next release of GDB, the sources will
4322 be permanently REMOVED.
4324 * Gould support removed
4326 Support for the Gould PowerNode and NP1 has been removed.
4328 * New features for SVR4
4330 On SVR4 native platforms (such as Solaris), if you attach to a process
4331 without first loading a symbol file, GDB will now attempt to locate and
4332 load symbols from the running process's executable file.
4334 * Many C++ enhancements
4336 C++ support has been greatly improved. Overload resolution now works properly
4337 in almost all cases. RTTI support is on the way.
4339 * Remote targets can connect to a sub-program
4341 A popen(3) style serial-device has been added. This device starts a
4342 sub-process (such as a stand-alone simulator) and then communicates
4343 with that. The sub-program to run is specified using the syntax
4344 ``|<program> <args>'' vis:
4346 (gdb) set remotedebug 1
4347 (gdb) target extended-remote |mn10300-elf-sim program-args
4349 * MIPS 64 remote protocol
4351 A long standing bug in the mips64 remote protocol where by GDB
4352 expected certain 32 bit registers (ex SR) to be transfered as 32
4353 instead of 64 bits has been fixed.
4355 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4356 added to provide backward compatibility with older versions of GDB.
4358 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4360 The command ``set remotebinarydownload'' command has been replaced by
4361 ``set remote X-packet''. Other commands in ``set remote'' family
4362 include ``set remote P-packet''.
4364 * Breakpoint commands accept ranges.
4366 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4367 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4368 ``tracepoint passcount'' also accepts a range of tracepoints.
4370 * ``apropos'' command added.
4372 The ``apropos'' command searches through command names and
4373 documentation strings, printing out matches, making it much easier to
4374 try to find a command that does what you are looking for.
4378 A new machine oriented interface (MI) has been added to GDB. This
4379 interface is designed for debug environments running GDB as a separate
4380 process. This is part of the long term libGDB project. See the
4381 "GDB/MI" chapter of the GDB manual for further information. It can be
4382 enabled by configuring with:
4384 .../configure --enable-gdbmi
4386 *** Changes in GDB-4.18:
4388 * New native configurations
4390 HP-UX 10.20 hppa*-*-hpux10.20
4391 HP-UX 11.x hppa*-*-hpux11.0*
4392 M68K GNU/Linux m68*-*-linux*
4396 Fujitsu FR30 fr30-*-elf*
4397 Intel StrongARM strongarm-*-*
4398 Mitsubishi D30V d30v-*-*
4400 * OBSOLETE configurations
4402 Gould PowerNode, NP1 np1-*-*, pn-*-*
4404 Configurations that have been declared obsolete will be commented out,
4405 but the code will be left in place. If there is no activity to revive
4406 these configurations before the next release of GDB, the sources will
4407 be permanently REMOVED.
4411 As a compatibility experiment, GDB's source files buildsym.h and
4412 buildsym.c have been converted to pure standard C, no longer
4413 containing any K&R compatibility code. We believe that all systems in
4414 use today either come with a standard C compiler, or have a GCC port
4415 available. If this is not true, please report the affected
4416 configuration to bug-gdb@gnu.org immediately. See the README file for
4417 information about getting a standard C compiler if you don't have one
4422 GDB now uses readline 2.2.
4424 * set extension-language
4426 You can now control the mapping between filename extensions and source
4427 languages by using the `set extension-language' command. For instance,
4428 you can ask GDB to treat .c files as C++ by saying
4429 set extension-language .c c++
4430 The command `info extensions' lists all of the recognized extensions
4431 and their associated languages.
4433 * Setting processor type for PowerPC and RS/6000
4435 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4436 you can use the `set processor' command to specify what variant of the
4437 PowerPC family you are debugging. The command
4441 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4442 following PowerPC and RS6000 variants:
4444 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4445 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4447 403GC IBM PowerPC 403GC
4448 505 Motorola PowerPC 505
4449 860 Motorola PowerPC 860 or 850
4450 601 Motorola PowerPC 601
4451 602 Motorola PowerPC 602
4452 603 Motorola/IBM PowerPC 603 or 603e
4453 604 Motorola PowerPC 604 or 604e
4454 750 Motorola/IBM PowerPC 750 or 750
4456 At the moment, this command just tells GDB what to name the
4457 special-purpose processor registers. Since almost all the affected
4458 registers are inaccessible to user-level programs, this command is
4459 only useful for remote debugging in its present form.
4463 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4464 more extensive support for HP-UX. Added features include shared
4465 library support, kernel threads and hardware watchpoints for 11.00,
4466 support for HP's ANSI C and C++ compilers, and a compatibility mode
4467 for xdb and dbx commands.
4471 HP's donation includes the new concept of catchpoints, which is a
4472 generalization of the old catch command. On HP-UX, it is now possible
4473 to catch exec, fork, and vfork, as well as library loading.
4475 This means that the existing catch command has changed; its first
4476 argument now specifies the type of catch to be set up. See the
4477 output of "help catch" for a list of catchpoint types.
4479 * Debugging across forks
4481 On HP-UX, you can choose which process to debug when a fork() happens
4486 HP has donated a curses-based terminal user interface (TUI). To get
4487 it, build with --enable-tui. Although this can be enabled for any
4488 configuration, at present it only works for native HP debugging.
4490 * GDB remote protocol additions
4492 A new protocol packet 'X' that writes binary data is now available.
4493 Default behavior is to try 'X', then drop back to 'M' if the stub
4494 fails to respond. The settable variable `remotebinarydownload'
4495 allows explicit control over the use of 'X'.
4497 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4498 full 64-bit address. The command
4500 set remoteaddresssize 32
4502 can be used to revert to the old behaviour. For existing remote stubs
4503 the change should not be noticed, as the additional address information
4506 In order to assist in debugging stubs, you may use the maintenance
4507 command `packet' to send any text string to the stub. For instance,
4509 maint packet heythere
4511 sends the packet "$heythere#<checksum>". Note that it is very easy to
4512 disrupt a debugging session by sending the wrong packet at the wrong
4515 The compare-sections command allows you to compare section data on the
4516 target to what is in the executable file without uploading or
4517 downloading, by comparing CRC checksums.
4519 * Tracing can collect general expressions
4521 You may now collect general expressions at tracepoints. This requires
4522 further additions to the target-side stub; see tracepoint.c and
4523 doc/agentexpr.texi for further details.
4525 * mask-address variable for Mips
4527 For Mips targets, you may control the zeroing of the upper 32 bits of
4528 a 64-bit address by entering `set mask-address on'. This is mainly
4529 of interest to users of embedded R4xxx and R5xxx processors.
4531 * Higher serial baud rates
4533 GDB's serial code now allows you to specify baud rates 57600, 115200,
4534 230400, and 460800 baud. (Note that your host system may not be able
4535 to achieve all of these rates.)
4539 The i960 configuration now includes an initial implementation of a
4540 builtin simulator, contributed by Jim Wilson.
4543 *** Changes in GDB-4.17:
4545 * New native configurations
4547 Alpha GNU/Linux alpha*-*-linux*
4548 Unixware 2.x i[3456]86-unixware2*
4549 Irix 6.x mips*-sgi-irix6*
4550 PowerPC GNU/Linux powerpc-*-linux*
4551 PowerPC Solaris powerpcle-*-solaris*
4552 Sparc GNU/Linux sparc-*-linux*
4553 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4557 Argonaut Risc Chip (ARC) arc-*-*
4558 Hitachi H8/300S h8300*-*-*
4559 Matsushita MN10200 w/simulator mn10200-*-*
4560 Matsushita MN10300 w/simulator mn10300-*-*
4561 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4562 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4563 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4564 Mitsubishi D10V w/simulator d10v-*-*
4565 Mitsubishi M32R/D w/simulator m32r-*-elf*
4566 Tsqware Sparclet sparclet-*-*
4567 NEC V850 w/simulator v850-*-*
4569 * New debugging protocols
4571 ARM with RDI protocol arm*-*-*
4572 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4573 DDB and LSI variants of PMON protocol mips*-*-*
4574 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4575 PowerPC with SDS protocol powerpc{,le}-*-eabi
4576 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4580 All configurations can now understand and use the DWARF 2 debugging
4581 format. The choice is automatic, if the symbol file contains DWARF 2
4586 GDB now includes basic Java language support. This support is
4587 only useful with Java compilers that produce native machine code.
4589 * solib-absolute-prefix and solib-search-path
4591 For SunOS and SVR4 shared libraries, you may now set the prefix for
4592 loading absolute shared library symbol files, and the search path for
4593 locating non-absolute shared library symbol files.
4595 * Live range splitting
4597 GDB can now effectively debug code for which GCC has performed live
4598 range splitting as part of its optimization. See gdb/doc/LRS for
4599 more details on the expected format of the stabs information.
4603 GDB's support for the GNU Hurd, including thread debugging, has been
4604 updated to work with current versions of the Hurd.
4608 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4609 instruction set. ARM GDB automatically detects when Thumb
4610 instructions are in use, and adjusts disassembly and backtracing
4615 GDB's MIPS target configurations now handle the MIP16 16-bit
4620 GDB now includes support for overlays; if an executable has been
4621 linked such that multiple sections are based at the same address, GDB
4622 will decide which section to use for symbolic info. You can choose to
4623 control the decision manually, using overlay commands, or implement
4624 additional target-side support and use "overlay load-target" to bring
4625 in the overlay mapping. Do "help overlay" for more detail.
4629 The command "info symbol <address>" displays information about
4630 the symbol at the specified address.
4634 The standard remote protocol now includes an extension that allows
4635 asynchronous collection and display of trace data. This requires
4636 extensive support in the target-side debugging stub. Tracing mode
4637 includes a new interaction mode in GDB and new commands: see the
4638 file tracepoint.c for more details.
4642 Configurations for embedded MIPS now include a simulator contributed
4643 by Cygnus Solutions. The simulator supports the instruction sets
4644 of most MIPS variants.
4648 Sparc configurations may now include the ERC32 simulator contributed
4649 by the European Space Agency. The simulator is not built into
4650 Sparc targets by default; configure with --enable-sim to include it.
4654 For target configurations that may include multiple variants of a
4655 basic architecture (such as MIPS and SH), you may now set the
4656 architecture explicitly. "set arch" sets, "info arch" lists
4657 the possible architectures.
4659 *** Changes in GDB-4.16:
4661 * New native configurations
4663 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4664 M68K NetBSD m68k-*-netbsd*
4665 PowerPC AIX 4.x powerpc-*-aix*
4666 PowerPC MacOS powerpc-*-macos*
4667 PowerPC Windows NT powerpcle-*-cygwin32
4668 RS/6000 AIX 4.x rs6000-*-aix4*
4672 ARM with RDP protocol arm-*-*
4673 I960 with MON960 i960-*-coff
4674 MIPS VxWorks mips*-*-vxworks*
4675 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4676 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4678 Matra Sparclet sparclet-*-*
4682 The powerpc-eabi configuration now includes the PSIM simulator,
4683 contributed by Andrew Cagney, with assistance from Mike Meissner.
4684 PSIM is a very elaborate model of the PowerPC, including not only
4685 basic instruction set execution, but also details of execution unit
4686 performance and I/O hardware. See sim/ppc/README for more details.
4690 GDB now works with Solaris 2.5.
4692 * Windows 95/NT native
4694 GDB will now work as a native debugger on Windows 95 and Windows NT.
4695 To build it from source, you must use the "gnu-win32" environment,
4696 which uses a DLL to emulate enough of Unix to run the GNU tools.
4697 Further information, binaries, and sources are available at
4698 ftp.cygnus.com, under pub/gnu-win32.
4700 * dont-repeat command
4702 If a user-defined command includes the command `dont-repeat', then the
4703 command will not be repeated if the user just types return. This is
4704 useful if the command is time-consuming to run, so that accidental
4705 extra keystrokes don't run the same command many times.
4707 * Send break instead of ^C
4709 The standard remote protocol now includes an option to send a break
4710 rather than a ^C to the target in order to interrupt it. By default,
4711 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4713 * Remote protocol timeout
4715 The standard remote protocol includes a new variable `remotetimeout'
4716 that allows you to set the number of seconds before GDB gives up trying
4717 to read from the target. The default value is 2.
4719 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4721 By default GDB will automatically keep track of objects as they are
4722 loaded and unloaded by the dynamic linker. By using the command `set
4723 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4724 when shared library events occur, thus allowing you to set breakpoints
4725 in shared libraries which are explicitly loaded by the inferior.
4727 Note this feature does not work on hpux8. On hpux9 you must link
4728 /usr/lib/end.o into your program. This feature should work
4729 automatically on hpux10.
4731 * Irix 5.x hardware watchpoint support
4733 Irix 5 configurations now support the use of hardware watchpoints.
4735 * Mips protocol "SYN garbage limit"
4737 When debugging a Mips target using the `target mips' protocol, you
4738 may set the number of characters that GDB will ignore by setting
4739 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4740 every character. The default value is 1050.
4742 * Recording and replaying remote debug sessions
4744 If you set `remotelogfile' to the name of a file, gdb will write to it
4745 a recording of a remote debug session. This recording may then be
4746 replayed back to gdb using "gdbreplay". See gdbserver/README for
4747 details. This is useful when you have a problem with GDB while doing
4748 remote debugging; you can make a recording of the session and send it
4749 to someone else, who can then recreate the problem.
4751 * Speedups for remote debugging
4753 GDB includes speedups for downloading and stepping MIPS systems using
4754 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4755 and more efficient S-record downloading.
4757 * Memory use reductions and statistics collection
4759 GDB now uses less memory and reports statistics about memory usage.
4760 Try the `maint print statistics' command, for example.
4762 *** Changes in GDB-4.15:
4764 * Psymtabs for XCOFF
4766 The symbol reader for AIX GDB now uses partial symbol tables. This
4767 can greatly improve startup time, especially for large executables.
4769 * Remote targets use caching
4771 Remote targets now use a data cache to speed up communication with the
4772 remote side. The data cache could lead to incorrect results because
4773 it doesn't know about volatile variables, thus making it impossible to
4774 debug targets which use memory mapped I/O devices. `set remotecache
4775 off' turns the the data cache off.
4777 * Remote targets may have threads
4779 The standard remote protocol now includes support for multiple threads
4780 in the target system, using new protocol commands 'H' and 'T'. See
4781 gdb/remote.c for details.
4785 If GDB is configured with `--enable-netrom', then it will include
4786 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4787 acts as though it is a bank of ROM on the target board, but you can
4788 write into it over the network. GDB's support consists only of
4789 support for fast loading into the emulated ROM; to debug, you must use
4790 another protocol, such as standard remote protocol. The usual
4791 sequence is something like
4793 target nrom <netrom-hostname>
4795 target remote <netrom-hostname>:1235
4799 GDB now includes support for the Apple Macintosh, as a host only. It
4800 may be run as either an MPW tool or as a standalone application, and
4801 it can debug through the serial port. All the usual GDB commands are
4802 available, but to the target command, you must supply "serial" as the
4803 device type instead of "/dev/ttyXX". See mpw-README in the main
4804 directory for more information on how to build. The MPW configuration
4805 scripts */mpw-config.in support only a few targets, and only the
4806 mips-idt-ecoff target has been tested.
4810 GDB configuration now uses autoconf. This is not user-visible,
4811 but does simplify configuration and building.
4815 GDB now supports hpux10.
4817 *** Changes in GDB-4.14:
4819 * New native configurations
4821 x86 FreeBSD i[345]86-*-freebsd
4822 x86 NetBSD i[345]86-*-netbsd
4823 NS32k NetBSD ns32k-*-netbsd
4824 Sparc NetBSD sparc-*-netbsd
4828 A29K VxWorks a29k-*-vxworks
4829 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4830 CPU32 EST-300 emulator m68*-*-est*
4831 PowerPC ELF powerpc-*-elf
4834 * Alpha OSF/1 support for procfs
4836 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4837 possible to attach to running processes. As the mounting of the /proc
4838 filesystem is optional on the Alpha, GDB automatically determines
4839 the availability of /proc during startup. This can lead to problems
4840 if /proc is unmounted after GDB has been started.
4842 * Arguments to user-defined commands
4844 User commands may accept up to 10 arguments separated by whitespace.
4845 Arguments are accessed within the user command via $arg0..$arg9. A
4848 print $arg0 + $arg1 + $arg2
4850 To execute the command use:
4853 Defines the command "adder" which prints the sum of its three arguments.
4854 Note the arguments are text substitutions, so they may reference variables,
4855 use complex expressions, or even perform inferior function calls.
4857 * New `if' and `while' commands
4859 This makes it possible to write more sophisticated user-defined
4860 commands. Both commands take a single argument, which is the
4861 expression to evaluate, and must be followed by the commands to
4862 execute, one per line, if the expression is nonzero, the list being
4863 terminated by the word `end'. The `if' command list may include an
4864 `else' word, which causes the following commands to be executed only
4865 if the expression is zero.
4867 * Fortran source language mode
4869 GDB now includes partial support for Fortran 77. It will recognize
4870 Fortran programs and can evaluate a subset of Fortran expressions, but
4871 variables and functions may not be handled correctly. GDB will work
4872 with G77, but does not yet know much about symbols emitted by other
4875 * Better HPUX support
4877 Most debugging facilities now work on dynamic executables for HPPAs
4878 running hpux9 or later. You can attach to running dynamically linked
4879 processes, but by default the dynamic libraries will be read-only, so
4880 for instance you won't be able to put breakpoints in them. To change
4881 that behavior do the following before running the program:
4887 This will cause the libraries to be mapped private and read-write.
4888 To revert to the normal behavior, do this:
4894 You cannot set breakpoints or examine data in the library until after
4895 the library is loaded if the function/data symbols do not have
4898 GDB can now also read debug symbols produced by the HP C compiler on
4899 HPPAs (sorry, no C++, Fortran or 68k support).
4901 * Target byte order now dynamically selectable
4903 You can choose which byte order to use with a target system, via the
4904 commands "set endian big" and "set endian little", and you can see the
4905 current setting by using "show endian". You can also give the command
4906 "set endian auto", in which case GDB will use the byte order
4907 associated with the executable. Currently, only embedded MIPS
4908 configurations support dynamic selection of target byte order.
4910 * New DOS host serial code
4912 This version uses DPMI interrupts to handle buffered I/O, so you
4913 no longer need to run asynctsr when debugging boards connected to
4916 *** Changes in GDB-4.13:
4918 * New "complete" command
4920 This lists all the possible completions for the rest of the line, if it
4921 were to be given as a command itself. This is intended for use by emacs.
4923 * Trailing space optional in prompt
4925 "set prompt" no longer adds a space for you after the prompt you set. This
4926 allows you to set a prompt which ends in a space or one that does not.
4928 * Breakpoint hit counts
4930 "info break" now displays a count of the number of times the breakpoint
4931 has been hit. This is especially useful in conjunction with "ignore"; you
4932 can ignore a large number of breakpoint hits, look at the breakpoint info
4933 to see how many times the breakpoint was hit, then run again, ignoring one
4934 less than that number, and this will get you quickly to the last hit of
4937 * Ability to stop printing at NULL character
4939 "set print null-stop" will cause GDB to stop printing the characters of
4940 an array when the first NULL is encountered. This is useful when large
4941 arrays actually contain only short strings.
4943 * Shared library breakpoints
4945 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4946 breakpoints in shared libraries before the executable is run.
4948 * Hardware watchpoints
4950 There is a new hardware breakpoint for the watch command for sparclite
4951 targets. See gdb/sparclite/hw_breakpoint.note.
4953 Hardware watchpoints are also now supported under GNU/Linux.
4957 Annotations have been added. These are for use with graphical interfaces,
4958 and are still experimental. Currently only gdba.el uses these.
4960 * Improved Irix 5 support
4962 GDB now works properly with Irix 5.2.
4964 * Improved HPPA support
4966 GDB now works properly with the latest GCC and GAS.
4968 * New native configurations
4970 Sequent PTX4 i[34]86-sequent-ptx4
4971 HPPA running OSF/1 hppa*-*-osf*
4972 Atari TT running SVR4 m68*-*-sysv4*
4973 RS/6000 LynxOS rs6000-*-lynxos*
4977 OS/9000 i[34]86-*-os9k
4978 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4981 * Hitachi SH7000 and E7000-PC ICE support
4983 There is now support for communicating with the Hitachi E7000-PC ICE.
4984 This is available automatically when GDB is configured for the SH.
4988 As usual, a variety of small fixes and improvements, both generic
4989 and configuration-specific. See the ChangeLog for more detail.
4991 *** Changes in GDB-4.12:
4993 * Irix 5 is now supported
4997 GDB-4.12 on the HPPA has a number of changes which make it unable
4998 to debug the output from the currently released versions of GCC and
4999 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5000 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5001 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5004 *** Changes in GDB-4.11:
5006 * User visible changes:
5010 The "set remotedebug" option is now consistent between the mips remote
5011 target, remote targets using the gdb-specific protocol, UDI (AMD's
5012 debug protocol for the 29k) and the 88k bug monitor. It is now an
5013 integer specifying a debug level (normally 0 or 1, but 2 means more
5014 debugging info for the mips target).
5016 * DEC Alpha native support
5018 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5019 debug info, but GDB works fairly well with the DEC compiler and should
5020 work with a future GCC release. See the README file for a few
5021 Alpha-specific notes.
5023 * Preliminary thread implementation
5025 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5027 * LynxOS native and target support for 386
5029 This release has been hosted on LynxOS 2.2, and also can be configured
5030 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5033 * Improvements in C++ mangling/demangling.
5035 This release has much better g++ debugging, specifically in name
5036 mangling/demangling, virtual function calls, print virtual table,
5037 call methods, ...etc.
5039 *** Changes in GDB-4.10:
5041 * User visible changes:
5043 Remote debugging using the GDB-specific (`target remote') protocol now
5044 supports the `load' command. This is only useful if you have some
5045 other way of getting the stub to the target system, and you can put it
5046 somewhere in memory where it won't get clobbered by the download.
5048 Filename completion now works.
5050 When run under emacs mode, the "info line" command now causes the
5051 arrow to point to the line specified. Also, "info line" prints
5052 addresses in symbolic form (as well as hex).
5054 All vxworks based targets now support a user settable option, called
5055 vxworks-timeout. This option represents the number of seconds gdb
5056 should wait for responses to rpc's. You might want to use this if
5057 your vxworks target is, perhaps, a slow software simulator or happens
5058 to be on the far side of a thin network line.
5062 This release contains support for using a DEC alpha as a GDB host for
5063 cross debugging. Native alpha debugging is not supported yet.
5066 *** Changes in GDB-4.9:
5070 This is the first GDB release which is accompanied by a matching testsuite.
5071 The testsuite requires installation of dejagnu, which should be available
5072 via ftp from most sites that carry GNU software.
5076 'Cfront' style demangling has had its name changed to 'ARM' style, to
5077 emphasize that it was written from the specifications in the C++ Annotated
5078 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5079 disclaimers, it still generated too much confusion with users attempting to
5080 use gdb with AT&T cfront.
5084 GDB now uses a standard remote interface to a simulator library.
5085 So far, the library contains simulators for the Zilog Z8001/2, the
5086 Hitachi H8/300, H8/500 and Super-H.
5088 * New targets supported
5090 H8/300 simulator h8300-hitachi-hms or h8300hms
5091 H8/500 simulator h8500-hitachi-hms or h8500hms
5092 SH simulator sh-hitachi-hms or sh
5093 Z8000 simulator z8k-zilog-none or z8ksim
5094 IDT MIPS board over serial line mips-idt-ecoff
5096 Cross-debugging to GO32 targets is supported. It requires a custom
5097 version of the i386-stub.c module which is integrated with the
5098 GO32 memory extender.
5100 * New remote protocols
5102 MIPS remote debugging protocol.
5104 * New source languages supported
5106 This version includes preliminary support for Chill, a Pascal like language
5107 used by telecommunications companies. Chill support is also being integrated
5108 into the GNU compiler, but we don't know when it will be publically available.
5111 *** Changes in GDB-4.8:
5113 * HP Precision Architecture supported
5115 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5116 version of this support was available as a set of patches from the
5117 University of Utah. GDB does not support debugging of programs
5118 compiled with the HP compiler, because HP will not document their file
5119 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5120 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5122 Many problems in the preliminary version have been fixed.
5124 * Faster and better demangling
5126 We have improved template demangling and fixed numerous bugs in the GNU style
5127 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5128 character types (wchar_t) are now supported. Demangling of each symbol is now
5129 only done once, and is cached when the symbol table for a file is read in.
5130 This results in a small increase in memory usage for C programs, a moderate
5131 increase in memory usage for C++ programs, and a fantastic speedup in
5134 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5135 from the specifications in the Annotated Reference Manual, which AT&T's
5136 compiler does not actually implement.
5138 * G++ multiple inheritance compiler problem
5140 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5141 inheritance lattices was reworked to properly discover ambiguities. We
5142 recently found an example which causes this new algorithm to fail in a
5143 very subtle way, producing bad debug information for those classes.
5144 The file 'gcc.patch' (in this directory) can be applied to gcc to
5145 circumvent the problem. A future GCC release will contain a complete
5148 The previous G++ debug info problem (mentioned below for the gdb-4.7
5149 release) is fixed in gcc version 2.3.2.
5151 * Improved configure script
5153 The `configure' script will now attempt to guess your system type if
5154 you don't supply a host system type. The old scheme of supplying a
5155 host system triplet is preferable over using this. All the magic is
5156 done in the new `config.guess' script. Examine it for details.
5158 We have also brought our configure script much more in line with the FSF's
5159 version. It now supports the --with-xxx options. In particular,
5160 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5161 The resulting GDB will not be able to read arbitrary object file formats --
5162 only the format ``expected'' to be used on the configured target system.
5163 We hope to make this the default in a future release.
5165 * Documentation improvements
5167 There's new internal documentation on how to modify GDB, and how to
5168 produce clean changes to the code. We implore people to read it
5169 before submitting changes.
5171 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5172 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5173 `info' files are also provided. To build `info' files from scratch,
5174 you will need the latest `makeinfo' release, which will be available in
5175 a future texinfo-X.Y release.
5177 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5178 We're not sure exactly which versions have this problem, but it has
5179 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5180 or better. If that isn't possible, there is a patch in
5181 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5182 around this problem.
5186 GDB now supports array constants that can be used in expressions typed in by
5187 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5188 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5191 The new directory `gdb/sparclite' contains a program that demonstrates
5192 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5194 * New native hosts supported
5196 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5197 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5199 * New targets supported
5201 AMD 29k family via UDI a29k-amd-udi or udi29k
5203 * New file formats supported
5205 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5206 HPUX core files, and SCO 3.2v2 core files.
5210 Attaching to processes now works again; thanks for the many bug reports.
5212 We have also stomped on a bunch of core dumps caused by
5213 printf_filtered("%s") problems.
5215 We eliminated a copyright problem on the rpc and ptrace header files
5216 for VxWorks, which was discovered at the last minute during the 4.7
5217 release. You should now be able to build a VxWorks GDB.
5219 You can now interrupt gdb while an attached process is running. This
5220 will cause the attached process to stop, and give control back to GDB.
5222 We fixed problems caused by using too many file descriptors
5223 for reading symbols from object files and libraries. This was
5224 especially a problem for programs that used many (~100) shared
5227 The `step' command now only enters a subroutine if there is line number
5228 information for the subroutine. Otherwise it acts like the `next'
5229 command. Previously, `step' would enter subroutines if there was
5230 any debugging information about the routine. This avoids problems
5231 when using `cc -g1' on MIPS machines.
5233 * Internal improvements
5235 GDB's internal interfaces have been improved to make it easier to support
5236 debugging of multiple languages in the future.
5238 GDB now uses a common structure for symbol information internally.
5239 Minimal symbols (derived from linkage symbols in object files), partial
5240 symbols (from a quick scan of debug information), and full symbols
5241 contain a common subset of information, making it easier to write
5242 shared code that handles any of them.
5244 * New command line options
5246 We now accept --silent as an alias for --quiet.
5250 The memory-mapped-malloc library is now licensed under the GNU Library
5251 General Public License.
5253 *** Changes in GDB-4.7:
5255 * Host/native/target split
5257 GDB has had some major internal surgery to untangle the support for
5258 hosts and remote targets. Now, when you configure GDB for a remote
5259 target, it will no longer load in all of the support for debugging
5260 local programs on the host. When fully completed and tested, this will
5261 ensure that arbitrary host/target combinations are possible.
5263 The primary conceptual shift is to separate the non-portable code in
5264 GDB into three categories. Host specific code is required any time GDB
5265 is compiled on that host, regardless of the target. Target specific
5266 code relates to the peculiarities of the target, but can be compiled on
5267 any host. Native specific code is everything else: it can only be
5268 built when the host and target are the same system. Child process
5269 handling and core file support are two common `native' examples.
5271 GDB's use of /proc for controlling Unix child processes is now cleaner.
5272 It has been split out into a single module under the `target_ops' vector,
5273 plus two native-dependent functions for each system that uses /proc.
5275 * New hosts supported
5277 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5278 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5279 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5281 * New targets supported
5283 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5284 68030 and CPU32 m68030-*-*, m68332-*-*
5286 * New native hosts supported
5288 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5289 (386bsd is not well tested yet)
5290 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5292 * New file formats supported
5294 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5295 supports reading of `a.out.adobe' object files, which are an a.out
5296 format extended with minimal information about multiple sections.
5300 `show copying' is the same as the old `info copying'.
5301 `show warranty' is the same as `info warrantee'.
5302 These were renamed for consistency. The old commands continue to work.
5304 `info handle' is a new alias for `info signals'.
5306 You can now define pre-command hooks, which attach arbitrary command
5307 scripts to any command. The commands in the hook will be executed
5308 prior to the user's command. You can also create a hook which will be
5309 executed whenever the program stops. See gdb.texinfo.
5313 We now deal with Cfront style name mangling, and can even extract type
5314 info from mangled symbols. GDB can automatically figure out which
5315 symbol mangling style your C++ compiler uses.
5317 Calling of methods and virtual functions has been improved as well.
5321 The crash that occured when debugging Sun Ansi-C compiled binaries is
5322 fixed. This was due to mishandling of the extra N_SO stabs output
5325 We also finally got Ultrix 4.2 running in house, and fixed core file
5326 support, with help from a dozen people on the net.
5328 John M. Farrell discovered that the reason that single-stepping was so
5329 slow on all of the Mips based platforms (primarily SGI and DEC) was
5330 that we were trying to demangle and lookup a symbol used for internal
5331 purposes on every instruction that was being stepped through. Changing
5332 the name of that symbol so that it couldn't be mistaken for a C++
5333 mangled symbol sped things up a great deal.
5335 Rich Pixley sped up symbol lookups in general by getting much smarter
5336 about when C++ symbol mangling is necessary. This should make symbol
5337 completion (TAB on the command line) much faster. It's not as fast as
5338 we'd like, but it's significantly faster than gdb-4.6.
5342 A new user controllable variable 'call_scratch_address' can
5343 specify the location of a scratch area to be used when GDB
5344 calls a function in the target. This is necessary because the
5345 usual method of putting the scratch area on the stack does not work
5346 in systems that have separate instruction and data spaces.
5348 We integrated changes to support the 29k UDI (Universal Debugger
5349 Interface), but discovered at the last minute that we didn't have all
5350 of the appropriate copyright paperwork. We are working with AMD to
5351 resolve this, and hope to have it available soon.
5355 We have sped up the remote serial line protocol, especially for targets
5356 with lots of registers. It now supports a new `expedited status' ('T')
5357 message which can be used in place of the existing 'S' status message.
5358 This allows the remote stub to send only the registers that GDB
5359 needs to make a quick decision about single-stepping or conditional
5360 breakpoints, eliminating the need to fetch the entire register set for
5361 each instruction being stepped through.
5363 The GDB remote serial protocol now implements a write-through cache for
5364 registers, only re-reading the registers if the target has run.
5366 There is also a new remote serial stub for SPARC processors. You can
5367 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5368 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5369 processor with a serial port.
5373 Configure.in files have become much easier to read and modify. A new
5374 `table driven' format makes it more obvious what configurations are
5375 supported, and what files each one uses.
5379 There is a new opcodes library which will eventually contain all of the
5380 disassembly routines and opcode tables. At present, it only contains
5381 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5382 disassembler (binutils/objdump) to share these routines.
5384 The libiberty library is now copylefted under the GNU Library General
5385 Public License. This allows more liberal use, and was done so libg++
5386 can use it. This makes no difference to GDB, since the Library License
5387 grants all the rights from the General Public License.
5391 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5392 reference to the stabs symbol info used by the debugger. It is (as far
5393 as we know) the only published document on this fascinating topic. We
5394 encourage you to read it, compare it to the stabs information on your
5395 system, and send improvements on the document in general (to
5396 bug-gdb@prep.ai.mit.edu).
5398 And, of course, many bugs have been fixed.
5401 *** Changes in GDB-4.6:
5403 * Better support for C++ function names
5405 GDB now accepts as input the "demangled form" of C++ overloaded function
5406 names and member function names, and can do command completion on such names
5407 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5408 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5409 Make use of command completion, it is your friend.
5411 GDB also now accepts a variety of C++ mangled symbol formats. They are
5412 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5413 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5414 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5415 for the list of formats.
5417 * G++ symbol mangling problem
5419 Recent versions of gcc have a bug in how they emit debugging information for
5420 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5421 directory) can be applied to gcc to fix the problem. Alternatively, if you
5422 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5423 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5424 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5427 * New 'maintenance' command
5429 All of the commands related to hacking GDB internals have been moved out of
5430 the main command set, and now live behind the 'maintenance' command. This
5431 can also be abbreviated as 'mt'. The following changes were made:
5433 dump-me -> maintenance dump-me
5434 info all-breakpoints -> maintenance info breakpoints
5435 printmsyms -> maintenance print msyms
5436 printobjfiles -> maintenance print objfiles
5437 printpsyms -> maintenance print psymbols
5438 printsyms -> maintenance print symbols
5440 The following commands are new:
5442 maintenance demangle Call internal GDB demangler routine to
5443 demangle a C++ link name and prints the result.
5444 maintenance print type Print a type chain for a given symbol
5446 * Change to .gdbinit file processing
5448 We now read the $HOME/.gdbinit file before processing the argv arguments
5449 (e.g. reading symbol files or core files). This allows global parameters to
5450 be set, which will apply during the symbol reading. The ./.gdbinit is still
5451 read after argv processing.
5453 * New hosts supported
5455 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5457 GNU/Linux support i386-unknown-linux or linux
5459 We are also including code to support the HP/PA running BSD and HPUX. This
5460 is almost guaranteed not to work, as we didn't have time to test or build it
5461 for this release. We are including it so that the more adventurous (or
5462 masochistic) of you can play with it. We also had major problems with the
5463 fact that the compiler that we got from HP doesn't support the -g option.
5466 * New targets supported
5468 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5470 * More smarts about finding #include files
5472 GDB now remembers the compilation directory for all include files, and for
5473 all files from which C is generated (like yacc and lex sources). This
5474 greatly improves GDB's ability to find yacc/lex sources, and include files,
5475 especially if you are debugging your program from a directory different from
5476 the one that contains your sources.
5478 We also fixed a bug which caused difficulty with listing and setting
5479 breakpoints in include files which contain C code. (In the past, you had to
5480 try twice in order to list an include file that you hadn't looked at before.)
5482 * Interesting infernals change
5484 GDB now deals with arbitrary numbers of sections, where the symbols for each
5485 section must be relocated relative to that section's landing place in the
5486 target's address space. This work was needed to support ELF with embedded
5487 stabs used by Solaris-2.0.
5489 * Bug fixes (of course!)
5491 There have been loads of fixes for the following things:
5492 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5493 i960, stabs, DOS(GO32), procfs, etc...
5495 See the ChangeLog for details.
5497 *** Changes in GDB-4.5:
5499 * New machines supported (host and target)
5501 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5503 SGI Irix-4.x mips-sgi-irix4 or iris4
5505 * New malloc package
5507 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5508 Mmalloc is capable of handling mutiple heaps of memory. It is also
5509 capable of saving a heap to a file, and then mapping it back in later.
5510 This can be used to greatly speedup the startup of GDB by using a
5511 pre-parsed symbol table which lives in a mmalloc managed heap. For
5512 more details, please read mmalloc/mmalloc.texi.
5516 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5517 'help info proc' for details.
5519 * MIPS ecoff symbol table format
5521 The code that reads MIPS symbol table format is now supported on all hosts.
5522 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5525 * File name changes for MS-DOS
5527 Many files in the config directories have been renamed to make it easier to
5528 support GDB on MS-DOSe systems (which have very restrictive file name
5529 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5530 environment) is close to working but has some remaining problems. Note
5531 that debugging of DOS programs is not supported, due to limitations
5532 in the ``operating system'', but it can be used to host cross-debugging.
5534 * Cross byte order fixes
5536 Many fixes have been made to support cross debugging of Sparc and MIPS
5537 targets from hosts whose byte order differs.
5539 * New -mapped and -readnow options
5541 If memory-mapped files are available on your system through the 'mmap'
5542 system call, you can use the -mapped option on the `file' or
5543 `symbol-file' commands to cause GDB to write the symbols from your
5544 program into a reusable file. If the program you are debugging is
5545 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5546 Future GDB debugging sessions will notice the presence of this file,
5547 and will quickly map in symbol information from it, rather than reading
5548 the symbol table from the executable program. Using the '-mapped'
5549 option in a GDB `file' or `symbol-file' command has the same effect as
5550 starting GDB with the '-mapped' command-line option.
5552 You can cause GDB to read the entire symbol table immediately by using
5553 the '-readnow' option with any of the commands that load symbol table
5554 information (or on the GDB command line). This makes the command
5555 slower, but makes future operations faster.
5557 The -mapped and -readnow options are typically combined in order to
5558 build a `fred.syms' file that contains complete symbol information.
5559 A simple GDB invocation to do nothing but build a `.syms' file for future
5562 gdb -batch -nx -mapped -readnow programname
5564 The `.syms' file is specific to the host machine on which GDB is run.
5565 It holds an exact image of GDB's internal symbol table. It cannot be
5566 shared across multiple host platforms.
5568 * longjmp() handling
5570 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5571 siglongjmp() without losing control. This feature has not yet been ported to
5572 all systems. It currently works on many 386 platforms, all MIPS-based
5573 platforms (SGI, DECstation, etc), and Sun3/4.
5577 Preliminary work has been put in to support the new Solaris OS from Sun. At
5578 this time, it can control and debug processes, but it is not capable of
5583 As always, many many bug fixes. The major areas were with g++, and mipsread.
5584 People using the MIPS-based platforms should experience fewer mysterious
5585 crashes and trashed symbol tables.
5587 *** Changes in GDB-4.4:
5589 * New machines supported (host and target)
5591 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5593 BSD Reno on Vax vax-dec-bsd
5594 Ultrix on Vax vax-dec-ultrix
5596 * New machines supported (target)
5598 AMD 29000 embedded, using EBMON a29k-none-none
5602 GDB continues to improve its handling of C++. `References' work better.
5603 The demangler has also been improved, and now deals with symbols mangled as
5604 per the Annotated C++ Reference Guide.
5606 GDB also now handles `stabs' symbol information embedded in MIPS
5607 `ecoff' symbol tables. Since the ecoff format was not easily
5608 extensible to handle new languages such as C++, this appeared to be a
5609 good way to put C++ debugging info into MIPS binaries. This option
5610 will be supported in the GNU C compiler, version 2, when it is
5613 * New features for SVR4
5615 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5616 shared libraries. Debugging dynamically linked programs should present
5617 only minor differences from debugging statically linked programs.
5619 The `info proc' command will print out information about any process
5620 on an SVR4 system (including the one you are debugging). At the moment,
5621 it prints the address mappings of the process.
5623 If you bring up GDB on another SVR4 system, please send mail to
5624 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5626 * Better dynamic linking support in SunOS
5628 Reading symbols from shared libraries which contain debugging symbols
5629 now works properly. However, there remain issues such as automatic
5630 skipping of `transfer vector' code during function calls, which
5631 make it harder to debug code in a shared library, than to debug the
5632 same code linked statically.
5636 GDB is now using the latest `getopt' routines from the FSF. This
5637 version accepts the -- prefix for options with long names. GDB will
5638 continue to accept the old forms (-option and +option) as well.
5639 Various single letter abbreviations for options have been explicity
5640 added to the option table so that they won't get overshadowed in the
5641 future by other options that begin with the same letter.
5645 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5646 Many assorted bugs have been handled. Many more remain to be handled.
5647 See the various ChangeLog files (primarily in gdb and bfd) for details.
5650 *** Changes in GDB-4.3:
5652 * New machines supported (host and target)
5654 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5655 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5656 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5658 * Almost SCO Unix support
5660 We had hoped to support:
5661 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5662 (except for core file support), but we discovered very late in the release
5663 that it has problems with process groups that render gdb unusable. Sorry
5664 about that. I encourage people to fix it and post the fixes.
5666 * Preliminary ELF and DWARF support
5668 GDB can read ELF object files on System V Release 4, and can handle
5669 debugging records for C, in DWARF format, in ELF files. This support
5670 is preliminary. If you bring up GDB on another SVR4 system, please
5671 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5676 GDB now uses the latest `readline' library. One user-visible change
5677 is that two tabs will list possible command completions, which previously
5678 required typing M-? (meta-question mark, or ESC ?).
5682 The `stepi' bug that many of you noticed has been squashed.
5683 Many bugs in C++ have been handled. Many more remain to be handled.
5684 See the various ChangeLog files (primarily in gdb and bfd) for details.
5686 * State of the MIPS world (in case you wondered):
5688 GDB can understand the symbol tables emitted by the compilers
5689 supplied by most vendors of MIPS-based machines, including DEC. These
5690 symbol tables are in a format that essentially nobody else uses.
5692 Some versions of gcc come with an assembler post-processor called
5693 mips-tfile. This program is required if you want to do source-level
5694 debugging of gcc-compiled programs. I believe FSF does not ship
5695 mips-tfile with gcc version 1, but it will eventually come with gcc
5698 Debugging of g++ output remains a problem. g++ version 1.xx does not
5699 really support it at all. (If you're lucky, you should be able to get
5700 line numbers and stack traces to work, but no parameters or local
5701 variables.) With some work it should be possible to improve the
5704 When gcc version 2 is released, you will have somewhat better luck.
5705 However, even then you will get confusing results for inheritance and
5708 We will eventually provide full debugging of g++ output on
5709 DECstations. This will probably involve some kind of stabs-in-ecoff
5710 encapulation, but the details have not been worked out yet.
5713 *** Changes in GDB-4.2:
5715 * Improved configuration
5717 Only one copy of `configure' exists now, and it is not self-modifying.
5718 Porting BFD is simpler.
5722 The `step' and `next' commands now only stop at the first instruction
5723 of a source line. This prevents the multiple stops that used to occur
5724 in switch statements, for-loops, etc. `Step' continues to stop if a
5725 function that has debugging information is called within the line.
5729 Lots of small bugs fixed. More remain.
5731 * New host supported (not target)
5733 Intel 386 PC clone running Mach i386-none-mach
5736 *** Changes in GDB-4.1:
5738 * Multiple source language support
5740 GDB now has internal scaffolding to handle several source languages.
5741 It determines the type of each source file from its filename extension,
5742 and will switch expression parsing and number formatting to match the
5743 language of the function in the currently selected stack frame.
5744 You can also specifically set the language to be used, with
5745 `set language c' or `set language modula-2'.
5749 GDB now has preliminary support for the GNU Modula-2 compiler,
5750 currently under development at the State University of New York at
5751 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5752 continue through the fall of 1991 and into 1992.
5754 Other Modula-2 compilers are currently not supported, and attempting to
5755 debug programs compiled with them will likely result in an error as the
5756 symbol table is read. Feel free to work on it, though!
5758 There are hooks in GDB for strict type checking and range checking,
5759 in the `Modula-2 philosophy', but they do not currently work.
5763 GDB can now write to executable and core files (e.g. patch
5764 a variable's value). You must turn this switch on, specify
5765 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5766 by assigning a new value to a variable. Modifications take
5769 * Automatic SunOS shared library reading
5771 When you run your program, GDB automatically determines where its
5772 shared libraries (if any) have been loaded, and reads their symbols.
5773 The `share' command is no longer needed. This also works when
5774 examining core files.
5778 You can specify the number of lines that the `list' command shows.
5781 * New machines supported (host and target)
5783 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5784 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5785 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5787 * New hosts supported (not targets)
5789 IBM RT/PC: romp-ibm-aix or rtpc
5791 * New targets supported (not hosts)
5793 AMD 29000 embedded with COFF a29k-none-coff
5794 AMD 29000 embedded with a.out a29k-none-aout
5795 Ultracomputer remote kernel debug a29k-nyu-kern
5797 * New remote interfaces
5803 *** Changes in GDB-4.0:
5807 Wide output is wrapped at good places to make the output more readable.
5809 Gdb now supports cross-debugging from a host machine of one type to a
5810 target machine of another type. Communication with the target system
5811 is over serial lines. The ``target'' command handles connecting to the
5812 remote system; the ``load'' command will download a program into the
5813 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5814 also supports debugging of realtime processes running under VxWorks,
5815 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5816 stub on the target system.
5818 New CPUs supported include the AMD 29000 and Intel 960.
5820 GDB now reads object files and symbol tables via a ``binary file''
5821 library, which allows a single copy of GDB to debug programs of multiple
5822 object file types such as a.out and coff.
5824 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5825 refcard.dvi and refcard.ps are available to format it).
5828 * Control-Variable user interface simplified
5830 All variables that control the operation of the debugger can be set
5831 by the ``set'' command, and displayed by the ``show'' command.
5833 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5834 ``Show prompt'' produces the response:
5835 Gdb's prompt is new-gdb=>.
5837 What follows are the NEW set commands. The command ``help set'' will
5838 print a complete list of old and new set commands. ``help set FOO''
5839 will give a longer description of the variable FOO. ``show'' will show
5840 all of the variable descriptions and their current settings.
5842 confirm on/off: Enables warning questions for operations that are
5843 hard to recover from, e.g. rerunning the program while
5844 it is already running. Default is ON.
5846 editing on/off: Enables EMACS style command line editing
5847 of input. Previous lines can be recalled with
5848 control-P, the current line can be edited with control-B,
5849 you can search for commands with control-R, etc.
5852 history filename NAME: NAME is where the gdb command history
5853 will be stored. The default is .gdb_history,
5854 or the value of the environment variable
5857 history size N: The size, in commands, of the command history. The
5858 default is 256, or the value of the environment variable
5861 history save on/off: If this value is set to ON, the history file will
5862 be saved after exiting gdb. If set to OFF, the
5863 file will not be saved. The default is OFF.
5865 history expansion on/off: If this value is set to ON, then csh-like
5866 history expansion will be performed on
5867 command line input. The default is OFF.
5869 radix N: Sets the default radix for input and output. It can be set
5870 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5871 in the current radix, so "set radix 10" is always a no-op.
5873 height N: This integer value is the number of lines on a page. Default
5874 is 24, the current `stty rows'' setting, or the ``li#''
5875 setting from the termcap entry matching the environment
5878 width N: This integer value is the number of characters on a line.
5879 Default is 80, the current `stty cols'' setting, or the ``co#''
5880 setting from the termcap entry matching the environment
5883 Note: ``set screensize'' is obsolete. Use ``set height'' and
5884 ``set width'' instead.
5886 print address on/off: Print memory addresses in various command displays,
5887 such as stack traces and structure values. Gdb looks
5888 more ``symbolic'' if you turn this off; it looks more
5889 ``machine level'' with it on. Default is ON.
5891 print array on/off: Prettyprint arrays. New convenient format! Default
5894 print demangle on/off: Print C++ symbols in "source" form if on,
5897 print asm-demangle on/off: Same, for assembler level printouts
5900 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5903 * Support for Epoch Environment.
5905 The epoch environment is a version of Emacs v18 with windowing. One
5906 new command, ``inspect'', is identical to ``print'', except that if you
5907 are running in the epoch environment, the value is printed in its own
5911 * Support for Shared Libraries
5913 GDB can now debug programs and core files that use SunOS shared libraries.
5914 Symbols from a shared library cannot be referenced
5915 before the shared library has been linked with the program (this
5916 happens after you type ``run'' and before the function main() is entered).
5917 At any time after this linking (including when examining core files
5918 from dynamically linked programs), gdb reads the symbols from each
5919 shared library when you type the ``sharedlibrary'' command.
5920 It can be abbreviated ``share''.
5922 sharedlibrary REGEXP: Load shared object library symbols for files
5923 matching a unix regular expression. No argument
5924 indicates to load symbols for all shared libraries.
5926 info sharedlibrary: Status of loaded shared libraries.
5931 A watchpoint stops execution of a program whenever the value of an
5932 expression changes. Checking for this slows down execution
5933 tremendously whenever you are in the scope of the expression, but is
5934 quite useful for catching tough ``bit-spreader'' or pointer misuse
5935 problems. Some machines such as the 386 have hardware for doing this
5936 more quickly, and future versions of gdb will use this hardware.
5938 watch EXP: Set a watchpoint (breakpoint) for an expression.
5940 info watchpoints: Information about your watchpoints.
5942 delete N: Deletes watchpoint number N (same as breakpoints).
5943 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5944 enable N: Re-enables watchpoint number N (same as breakpoints).
5947 * C++ multiple inheritance
5949 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5952 * C++ exception handling
5954 Gdb now supports limited C++ exception handling. Besides the existing
5955 ability to breakpoint on an exception handler, gdb can breakpoint on
5956 the raising of an exception (before the stack is peeled back to the
5959 catch FOO: If there is a FOO exception handler in the dynamic scope,
5960 set a breakpoint to catch exceptions which may be raised there.
5961 Multiple exceptions (``catch foo bar baz'') may be caught.
5963 info catch: Lists all exceptions which may be caught in the
5964 current stack frame.
5967 * Minor command changes
5969 The command ``call func (arg, arg, ...)'' now acts like the print
5970 command, except it does not print or save a value if the function's result
5971 is void. This is similar to dbx usage.
5973 The ``up'' and ``down'' commands now always print the frame they end up
5974 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5975 frames without printing.
5977 * New directory command
5979 'dir' now adds directories to the FRONT of the source search path.
5980 The path starts off empty. Source files that contain debug information
5981 about the directory in which they were compiled can be found even
5982 with an empty path; Sun CC and GCC include this information. If GDB can't
5983 find your source file in the current directory, type "dir .".
5985 * Configuring GDB for compilation
5987 For normal use, type ``./configure host''. See README or gdb.texinfo
5990 GDB now handles cross debugging. If you are remotely debugging between
5991 two different machines, type ``./configure host -target=targ''.
5992 Host is the machine where GDB will run; targ is the machine
5993 where the program that you are debugging will run.