1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.9
7 * GDB now honors the content of the file /proc/PID/coredump_filter
8 (PID is the process ID) on GNU/Linux systems. This file can be used
9 to specify the types of memory mappings that will be included in a
10 corefile. For more information, please refer to the manual page of
11 "core(5)". GDB also has a new command: "set use-coredump-filter
12 on|off". It allows to set whether GDB will read the content of the
13 /proc/PID/coredump_filter file when generating a corefile.
15 * The "info os" command on GNU/Linux can now display information on
17 "info os cpus" Listing of all cpus/cores on the system
19 * GDB has two new commands: "set serial parity odd|even|none" and
20 "show serial parity". These allows to set or show parity for the
23 * The "info source" command now displays the producer string if it was
24 present in the debug info. This typically includes the compiler version
25 and may include things like its command line arguments.
27 * Directory names supplied to the "set sysroot" commands may be
28 prefixed with "target:" to tell GDB to access shared libraries from
29 the target system, be it local or remote. This replaces the prefix
30 "remote:". The default sysroot has been changed from "" to
31 "target:". "remote:" is automatically converted to "target:" for
32 backward compatibility.
36 ** gdb.Objfile objects have a new attribute "username",
37 which is the name of the objfile as specified by the user,
38 without, for example, resolving symlinks.
39 ** You can now write frame unwinders in Python.
43 maint print symbol-cache
44 Print the contents of the symbol cache.
46 maint print symbol-cache-statistics
47 Print statistics of symbol cache usage.
49 maint flush-symbol-cache
50 Flush the contents of the symbol cache.
54 Start branch trace recording using Branch Trace Store (BTS) format.
60 Set the maximum number of candidates to be considered during
61 completion. The default value is 200. This limit allows GDB
62 to avoid generating large completion lists, the computation of
63 which can cause the debugger to become temporarily unresponsive.
65 maint set symbol-cache-size
66 maint show symbol-cache-size
67 Control the size of the symbol cache.
69 set|show record btrace bts buffer-size
70 Set and show the size of the ring buffer used for branch tracing in
72 The obtained size may differ from the requested size. Use "info
73 record" to see the obtained buffer size.
75 * The command 'thread apply all' can now support new option '-ascending'
76 to call its specified command for all threads in ascending order.
78 * Python/Guile scripting
80 ** GDB now supports auto-loading of Python/Guile scripts contained in the
81 special section named `.debug_gdb_scripts'.
85 qXfer:btrace-conf:read
86 Return the branch trace configuration for the current thread.
89 Set the requested ring buffer size for branch tracing in BTS format.
92 Indicates a memory breakpoint instruction was executed, irrespective
93 of whether it was GDB that planted the breakpoint or the breakpoint
94 is hardcoded in the program. This is required for correct non-stop
98 Indicates the target stopped for a hardware breakpoint. This is
99 required for correct non-stop mode operation.
102 Return information about files on the remote system.
104 * The info record command now shows the recording format and the
105 branch tracing configuration for the current thread when using
106 the btrace record target.
107 For the BTS format, it shows the ring buffer size.
109 * GDB now has support for DTrace USDT (Userland Static Defined
110 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
112 * GDB now supports access to vector registers on S/390 GNU/Linux
115 * Removed targets and native configurations
117 HP/PA running HP-UX hppa*-*-hpux*
118 Itanium running HP-UX ia64-*-hpux*
120 *** Changes in GDB 7.9
122 * GDB now supports hardware watchpoints on x86 GNU Hurd.
126 ** You can now access frame registers from Python scripts.
127 ** New attribute 'producer' for gdb.Symtab objects.
128 ** gdb.Objfile objects have a new attribute "progspace",
129 which is the gdb.Progspace object of the containing program space.
130 ** gdb.Objfile objects have a new attribute "owner".
131 ** gdb.Objfile objects have a new attribute "build_id",
132 which is the build ID generated when the file was built.
133 ** gdb.Objfile objects have a new method "add_separate_debug_file".
134 ** A new event "gdb.clear_objfiles" has been added, triggered when
135 selecting a new file to debug.
136 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
137 ** New function gdb.lookup_objfile.
139 New events which are triggered when GDB modifies the state of the
142 ** gdb.events.inferior_call_pre: Function call is about to be made.
143 ** gdb.events.inferior_call_post: Function call has just been made.
144 ** gdb.events.memory_changed: A memory location has been altered.
145 ** gdb.events.register_changed: A register has been altered.
147 * New Python-based convenience functions:
149 ** $_caller_is(name [, number_of_frames])
150 ** $_caller_matches(regexp [, number_of_frames])
151 ** $_any_caller_is(name [, number_of_frames])
152 ** $_any_caller_matches(regexp [, number_of_frames])
154 * GDB now supports the compilation and injection of source code into
155 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
156 to compile the source code to object code, and if successful, inject
157 and execute that code within the current context of the inferior.
158 Currently the C language is supported. The commands used to
159 interface with this new feature are:
161 compile code [-raw|-r] [--] [source code]
162 compile file [-raw|-r] filename
166 demangle [-l language] [--] name
167 Demangle "name" in the specified language, or the current language
168 if elided. This command is renamed from the "maint demangle" command.
169 The latter is kept as a no-op to avoid "maint demangle" being interpreted
170 as "maint demangler-warning".
172 queue-signal signal-name-or-number
173 Queue a signal to be delivered to the thread when it is resumed.
175 add-auto-load-scripts-directory directory
176 Add entries to the list of directories from which to load auto-loaded
179 maint print user-registers
180 List all currently available "user" registers.
182 compile code [-r|-raw] [--] [source code]
183 Compile, inject, and execute in the inferior the executable object
184 code produced by compiling the provided source code.
186 compile file [-r|-raw] filename
187 Compile and inject into the inferior the executable object code
188 produced by compiling the source code stored in the filename
191 * On resume, GDB now always passes the signal the program had stopped
192 for to the thread the signal was sent to, even if the user changed
193 threads before resuming. Previously GDB would often (but not
194 always) deliver the signal to the thread that happens to be current
197 * Conversely, the "signal" command now consistently delivers the
198 requested signal to the current thread. GDB now asks for
199 confirmation if the program had stopped for a signal and the user
200 switched threads meanwhile.
202 * "breakpoint always-inserted" modes "off" and "auto" merged.
204 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
205 won't remove breakpoints from the target until all threads stop,
206 even in non-stop mode. The "auto" mode has been removed, and "off"
207 is now the default mode.
211 set debug symbol-lookup
212 show debug symbol-lookup
213 Control display of debugging info regarding symbol lookup.
217 ** The -list-thread-groups command outputs an exit-code field for
218 inferiors that have exited.
222 MIPS SDE mips*-sde*-elf*
226 Support for these obsolete configurations has been removed.
228 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
229 SGI Irix-5.x mips-*-irix5*
230 SGI Irix-6.x mips-*-irix6*
231 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
232 VAX running Ultrix vax-*-ultrix*
234 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
235 and "assf"), have been removed. Use the "sharedlibrary" command, or
236 its alias "share", instead.
238 *** Changes in GDB 7.8
240 * New command line options
243 This is an alias for the --data-directory option.
245 * GDB supports printing and modifying of variable length automatic arrays
246 as specified in ISO C99.
248 * The ARM simulator now supports instruction level tracing
249 with or without disassembly.
253 GDB now has support for scripting using Guile. Whether this is
254 available is determined at configure time.
255 Guile version 2.0 or greater is required.
256 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
258 * New commands (for set/show, see "New options" below)
262 Invoke CODE by passing it to the Guile interpreter.
266 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
268 info auto-load guile-scripts [regexp]
269 Print the list of automatically loaded Guile scripts.
271 * The source command is now capable of sourcing Guile scripts.
272 This feature is dependent on the debugger being built with Guile support.
276 set print symbol-loading (off|brief|full)
277 show print symbol-loading
278 Control whether to print informational messages when loading symbol
279 information for a file. The default is "full", but when debugging
280 programs with large numbers of shared libraries the amount of output
283 set guile print-stack (none|message|full)
284 show guile print-stack
285 Show a stack trace when an error is encountered in a Guile script.
287 set auto-load guile-scripts (on|off)
288 show auto-load guile-scripts
289 Control auto-loading of Guile script files.
291 maint ada set ignore-descriptive-types (on|off)
292 maint ada show ignore-descriptive-types
293 Control whether the debugger should ignore descriptive types in Ada
294 programs. The default is not to ignore the descriptive types. See
295 the user manual for more details on descriptive types and the intended
296 usage of this option.
298 set auto-connect-native-target
300 Control whether GDB is allowed to automatically connect to the
301 native target for the run, attach, etc. commands when not connected
302 to any target yet. See also "target native" below.
304 set record btrace replay-memory-access (read-only|read-write)
305 show record btrace replay-memory-access
306 Control what memory accesses are allowed during replay.
308 maint set target-async (on|off)
309 maint show target-async
310 This controls whether GDB targets operate in synchronous or
311 asynchronous mode. Normally the default is asynchronous, if it is
312 available; but this can be changed to more easily debug problems
313 occurring only in synchronous mode.
315 set mi-async (on|off)
317 Control whether MI asynchronous mode is preferred. This supersedes
318 "set target-async" of previous GDB versions.
320 * "set target-async" is deprecated as a CLI option and is now an alias
321 for "set mi-async" (only puts MI into async mode).
323 * Background execution commands (e.g., "c&", "s&", etc.) are now
324 possible ``out of the box'' if the target supports them. Previously
325 the user would need to explicitly enable the possibility with the
326 "set target-async on" command.
328 * New features in the GDB remote stub, GDBserver
330 ** New option --debug-format=option1[,option2,...] allows one to add
331 additional text to each output. At present only timestamps
332 are supported: --debug-format=timestamps.
333 Timestamps can also be turned on with the
334 "monitor set debug-format timestamps" command from GDB.
336 * The 'record instruction-history' command now starts counting instructions
337 at one. This also affects the instruction ranges reported by the
338 'record function-call-history' command when given the /i modifier.
340 * The command 'record function-call-history' supports a new modifier '/c' to
341 indent the function names based on their call stack depth.
342 The fields for the '/i' and '/l' modifier have been reordered.
343 The source line range is now prefixed with 'at'.
344 The instruction range is now prefixed with 'inst'.
345 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
346 "record instruction-history" and "list" commands.
348 * The ranges given as arguments to the 'record function-call-history' and
349 'record instruction-history' commands are now inclusive.
351 * The btrace record target now supports the 'record goto' command.
352 For locations inside the execution trace, the back trace is computed
353 based on the information stored in the execution trace.
355 * The btrace record target supports limited reverse execution and replay.
356 The target does not record data and therefore does not allow reading
359 * The "catch syscall" command now works on s390*-linux* targets.
361 * The "compare-sections" command is no longer specific to target
362 remote. It now works with all targets.
364 * All native targets are now consistently called "native".
365 Consequently, the "target child", "target GNU", "target djgpp",
366 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
367 commands have been replaced with "target native". The QNX/NTO port
368 leaves the "procfs" target in place and adds a "native" target for
369 consistency with other ports. The impact on users should be minimal
370 as these commands previously either throwed an error, or were
371 no-ops. The target's name is visible in the output of the following
372 commands: "help target", "info target", "info files", "maint print
375 * The "target native" command now connects to the native target. This
376 can be used to launch native programs even when "set
377 auto-connect-native-target" is set to off.
379 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.
381 * Support for Intel(R) AVX-512 registers on GNU/Linux.
382 Support displaying and modifying Intel(R) AVX-512 registers
383 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
387 qXfer:btrace:read's annex
388 The qXfer:btrace:read packet supports a new annex 'delta' to read
389 branch trace incrementally.
393 ** Valid Python operations on gdb.Value objects representing
394 structs/classes invoke the corresponding overloaded operators if
396 ** New `Xmethods' feature in the Python API. Xmethods are
397 additional methods or replacements for existing methods of a C++
398 class. This feature is useful for those cases where a method
399 defined in C++ source code could be inlined or optimized out by
400 the compiler, making it unavailable to GDB.
403 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
405 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
406 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
407 its alias "share", instead.
409 * The commands "set remotebaud" and "show remotebaud" are no longer
410 supported. Use "set serial baud" and "show serial baud" (respectively)
415 ** A new option "-gdb-set mi-async" replaces "-gdb-set
416 target-async". The latter is left as a deprecated alias of the
417 former for backward compatibility. If the target supports it,
418 CLI background execution commands are now always possible by
419 default, independently of whether the frontend stated a
420 preference for asynchronous execution with "-gdb-set mi-async".
421 Previously "-gdb-set target-async off" affected both MI execution
422 commands and CLI execution commands.
424 *** Changes in GDB 7.7
426 * Improved support for process record-replay and reverse debugging on
427 arm*-linux* targets. Support for thumb32 and syscall instruction
428 recording has been added.
430 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
432 * GDB now supports Fission DWP file format version 2.
433 http://gcc.gnu.org/wiki/DebugFission
435 * New convenience function "$_isvoid", to check whether an expression
436 is void. A void expression is an expression where the type of the
437 result is "void". For example, some convenience variables may be
438 "void" when evaluated (e.g., "$_exitcode" before the execution of
439 the program being debugged; or an undefined convenience variable).
440 Another example, when calling a function whose return type is
443 * The "maintenance print objfiles" command now takes an optional regexp.
445 * The "catch syscall" command now works on arm*-linux* targets.
447 * GDB now consistently shows "<not saved>" when printing values of
448 registers the debug info indicates have not been saved in the frame
449 and there's nowhere to retrieve them from
450 (callee-saved/call-clobbered registers):
455 (gdb) info registers rax
458 Before, the former would print "<optimized out>", and the latter
459 "*value not available*".
461 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
466 ** Frame filters and frame decorators have been added.
467 ** Temporary breakpoints are now supported.
468 ** Line tables representation has been added.
469 ** New attribute 'parent_type' for gdb.Field objects.
470 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
471 ** New attribute 'name' for gdb.Type objects.
475 Nios II ELF nios2*-*-elf
476 Nios II GNU/Linux nios2*-*-linux
477 Texas Instruments MSP430 msp430*-*-elf
479 * Removed native configurations
481 Support for these a.out NetBSD and OpenBSD obsolete configurations has
482 been removed. ELF variants of these configurations are kept supported.
484 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
485 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
486 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
487 i[34567]86-*-openbsd3.[0-3]
488 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
489 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
490 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
494 Like "catch throw", but catches a re-thrown exception.
496 Renamed from old "maint check-symtabs".
498 Perform consistency checks on symtabs.
500 Expand symtabs matching an optional regexp.
503 Display the details of GDB configure-time options.
505 maint set|show per-command
506 maint set|show per-command space
507 maint set|show per-command time
508 maint set|show per-command symtab
509 Enable display of per-command gdb resource usage.
511 remove-symbol-file FILENAME
512 remove-symbol-file -a ADDRESS
513 Remove a symbol file added via add-symbol-file. The file to remove
514 can be identified by its filename or by an address that lies within
515 the boundaries of this symbol file in memory.
518 info exceptions REGEXP
519 Display the list of Ada exceptions defined in the program being
520 debugged. If provided, only the exceptions whose names match REGEXP
525 set debug symfile off|on
527 Control display of debugging info regarding reading symbol files and
528 symbol tables within those files
530 set print raw frame-arguments
531 show print raw frame-arguments
532 Set/show whether to print frame arguments in raw mode,
533 disregarding any defined pretty-printers.
535 set remote trace-status-packet
536 show remote trace-status-packet
537 Set/show the use of remote protocol qTStatus packet.
541 Control display of debugging messages related to Nios II targets.
545 Control whether target-assisted range stepping is enabled.
547 set startup-with-shell
548 show startup-with-shell
549 Specifies whether Unix child processes are started via a shell or
554 Use the target memory cache for accesses to the code segment. This
555 improves performance of remote debugging (particularly disassembly).
557 * You can now use a literal value 'unlimited' for options that
558 interpret 0 or -1 as meaning "unlimited". E.g., "set
559 trace-buffer-size unlimited" is now an alias for "set
560 trace-buffer-size -1" and "set height unlimited" is now an alias for
563 * The "set debug symtab-create" debugging option of GDB has been changed to
564 accept a verbosity level. 0 means "off", 1 provides basic debugging
565 output, and values of 2 or greater provides more verbose output.
567 * New command-line options
569 Display the details of GDB configure-time options.
571 * The command 'tsave' can now support new option '-ctf' to save trace
572 buffer in Common Trace Format.
574 * Newly installed $prefix/bin/gcore acts as a shell interface for the
577 * GDB now implements the the C++ 'typeid' operator.
579 * The new convenience variable $_exception holds the exception being
580 thrown or caught at an exception-related catchpoint.
582 * The exception-related catchpoints, like "catch throw", now accept a
583 regular expression which can be used to filter exceptions by type.
585 * The new convenience variable $_exitsignal is automatically set to
586 the terminating signal number when the program being debugged dies
587 due to an uncaught signal.
591 ** All MI commands now accept an optional "--language" option.
592 Support for this feature can be verified by using the "-list-features"
593 command, which should contain "language-option".
595 ** The new command -info-gdb-mi-command allows the user to determine
596 whether a GDB/MI command is supported or not.
598 ** The "^error" result record returned when trying to execute an undefined
599 GDB/MI command now provides a variable named "code" whose content is the
600 "undefined-command" error code. Support for this feature can be verified
601 by using the "-list-features" command, which should contain
602 "undefined-command-error-code".
604 ** The -trace-save MI command can optionally save trace buffer in Common
607 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
609 ** The command -data-list-register-values now accepts an optional
610 "--skip-unavailable" option. When used, only the available registers
613 ** The new command -trace-frame-collected dumps collected variables,
614 computed expressions, tvars, memory and registers in a traceframe.
616 ** The commands -stack-list-locals, -stack-list-arguments and
617 -stack-list-variables now accept an option "--skip-unavailable".
618 When used, only the available locals or arguments are displayed.
620 ** The -exec-run command now accepts an optional "--start" option.
621 When used, the command follows the same semantics as the "start"
622 command, stopping the program's execution at the start of its
623 main subprogram. Support for this feature can be verified using
624 the "-list-features" command, which should contain
625 "exec-run-start-option".
627 ** The new commands -catch-assert and -catch-exceptions insert
628 catchpoints stopping the program when Ada exceptions are raised.
630 ** The new command -info-ada-exceptions provides the equivalent of
631 the new "info exceptions" command.
633 * New system-wide configuration scripts
634 A GDB installation now provides scripts suitable for use as system-wide
635 configuration scripts for the following systems:
639 * GDB now supports target-assigned range stepping with remote targets.
640 This improves the performance of stepping source lines by reducing
641 the number of control packets from/to GDB. See "New remote packets"
644 * GDB now understands the element 'tvar' in the XML traceframe info.
645 It has the id of the collected trace state variables.
647 * On S/390 targets that provide the transactional-execution feature,
648 the program interruption transaction diagnostic block (TDB) is now
649 represented as a number of additional "registers" in GDB.
655 The vCont packet supports a new 'r' action, that tells the remote
656 stub to step through an address range itself, without GDB
657 involvemement at each single-step.
659 qXfer:libraries-svr4:read's annex
660 The previously unused annex of the qXfer:libraries-svr4:read packet
661 is now used to support passing an argument list. The remote stub
662 reports support for this argument list to GDB's qSupported query.
663 The defined arguments are "start" and "prev", used to reduce work
664 necessary for library list updating, resulting in significant
667 * New features in the GDB remote stub, GDBserver
669 ** GDBserver now supports target-assisted range stepping. Currently
670 enabled on x86/x86_64 GNU/Linux targets.
672 ** GDBserver now adds element 'tvar' in the XML in the reply to
673 'qXfer:traceframe-info:read'. It has the id of the collected
674 trace state variables.
676 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
679 * New 'z' formatter for printing and examining memory, this displays the
680 value as hexadecimal zero padded on the left to the size of the type.
682 * GDB can now use Windows x64 unwinding data.
684 * The "set remotebaud" command has been replaced by "set serial baud".
685 Similarly, "show remotebaud" has been replaced by "show serial baud".
686 The "set remotebaud" and "show remotebaud" commands are still available
687 to provide backward compatibility with older versions of GDB.
689 *** Changes in GDB 7.6
691 * Target record has been renamed to record-full.
692 Record/replay is now enabled with the "record full" command.
693 This also affects settings that are associated with full record/replay
694 that have been moved from "set/show record" to "set/show record full":
696 set|show record full insn-number-max
697 set|show record full stop-at-limit
698 set|show record full memory-query
700 * A new record target "record-btrace" has been added. The new target
701 uses hardware support to record the control-flow of a process. It
702 does not support replaying the execution, but it implements the
703 below new commands for investigating the recorded execution log.
704 This new recording method can be enabled using:
708 The "record-btrace" target is only available on Intel Atom processors
709 and requires a Linux kernel 2.6.32 or later.
711 * Two new commands have been added for record/replay to give information
712 about the recorded execution without having to replay the execution.
713 The commands are only supported by "record btrace".
715 record instruction-history prints the execution history at
716 instruction granularity
718 record function-call-history prints the execution history at
721 * New native configurations
723 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
724 FreeBSD/powerpc powerpc*-*-freebsd
725 x86_64/Cygwin x86_64-*-cygwin*
726 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
730 ARM AArch64 aarch64*-*-elf
731 ARM AArch64 GNU/Linux aarch64*-*-linux
732 Lynx 178 PowerPC powerpc-*-lynx*178
733 x86_64/Cygwin x86_64-*-cygwin*
734 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
736 * If the configured location of system.gdbinit file (as given by the
737 --with-system-gdbinit option at configure time) is in the
738 data-directory (as specified by --with-gdb-datadir at configure
739 time) or in one of its subdirectories, then GDB will look for the
740 system-wide init file in the directory specified by the
741 --data-directory command-line option.
743 * New command line options:
745 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
746 other initialization files, unlike -nx which disables all of them.
748 * Removed command line options
750 -epoch This was used by the gdb mode in Epoch, an ancient fork of
753 * The 'ptype' and 'whatis' commands now accept an argument to control
756 * 'info proc' now works on some core files.
760 ** Vectors can be created with gdb.Type.vector.
762 ** Python's atexit.register now works in GDB.
764 ** Types can be pretty-printed via a Python API.
766 ** Python 3 is now supported (in addition to Python 2.4 or later)
768 ** New class gdb.Architecture exposes GDB's internal representation
769 of architecture in the Python API.
771 ** New method Frame.architecture returns the gdb.Architecture object
772 corresponding to the frame's architecture.
774 * New Python-based convenience functions:
776 ** $_memeq(buf1, buf2, length)
777 ** $_streq(str1, str2)
779 ** $_regex(str, regex)
781 * The 'cd' command now defaults to using '~' (the home directory) if not
784 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
785 default for GCC since November 2000.
787 * The command 'forward-search' can now be abbreviated as 'fo'.
789 * The command 'info tracepoints' can now display 'installed on target'
790 or 'not installed on target' for each non-pending location of tracepoint.
792 * New configure options
794 --enable-libmcheck/--disable-libmcheck
795 By default, development versions are built with -lmcheck on hosts
796 that support it, in order to help track memory corruption issues.
797 Release versions, on the other hand, are built without -lmcheck
798 by default. The --enable-libmcheck/--disable-libmcheck configure
799 options allow the user to override that default.
800 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
801 This configure option allows the user to build GDB with
802 libbabeltrace using which GDB can read Common Trace Format data.
804 * New commands (for set/show, see "New options" below)
807 Catch signals. This is similar to "handle", but allows commands and
808 conditions to be attached.
811 List the BFDs known to GDB.
813 python-interactive [command]
815 Start a Python interactive prompt, or evaluate the optional command
816 and print the result of expressions.
819 "py" is a new alias for "python".
821 enable type-printer [name]...
822 disable type-printer [name]...
823 Enable or disable type printers.
827 ** For the Renesas Super-H architecture, the "regs" command has been removed
828 (has been deprecated in GDB 7.5), and "info all-registers" should be used
833 set print type methods (on|off)
834 show print type methods
835 Control whether method declarations are displayed by "ptype".
836 The default is to show them.
838 set print type typedefs (on|off)
839 show print type typedefs
840 Control whether typedef definitions are displayed by "ptype".
841 The default is to show them.
843 set filename-display basename|relative|absolute
844 show filename-display
845 Control the way in which filenames is displayed.
846 The default is "relative", which preserves previous behavior.
848 set trace-buffer-size
849 show trace-buffer-size
850 Request target to change the size of trace buffer.
852 set remote trace-buffer-size-packet auto|on|off
853 show remote trace-buffer-size-packet
854 Control the use of the remote protocol `QTBuffer:size' packet.
858 Control display of debugging messages related to ARM AArch64.
861 set debug coff-pe-read
862 show debug coff-pe-read
863 Control display of debugging messages related to reading of COFF/PE
868 Control display of debugging messages related to Mach-O symbols
871 set debug notification
872 show debug notification
873 Control display of debugging info for async remote notification.
877 ** Command parameter changes are now notified using new async record
878 "=cmd-param-changed".
879 ** Trace frame changes caused by command "tfind" are now notified using
880 new async record "=traceframe-changed".
881 ** The creation, deletion and modification of trace state variables
882 are now notified using new async records "=tsv-created",
883 "=tsv-deleted" and "=tsv-modified".
884 ** The start and stop of process record are now notified using new
885 async record "=record-started" and "=record-stopped".
886 ** Memory changes are now notified using new async record
888 ** The data-disassemble command response will include a "fullname" field
889 containing the absolute file name when source has been requested.
890 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
891 command, to allow pattern filling of memory areas.
892 ** New commands "-catch-load"/"-catch-unload" added for intercepting
893 library load/unload events.
894 ** The response to breakpoint commands and breakpoint async records
895 includes an "installed" field containing a boolean state about each
896 non-pending tracepoint location is whether installed on target or not.
897 ** Output of the "-trace-status" command includes a "trace-file" field
898 containing the name of the trace file being examined. This field is
899 optional, and only present when examining a trace file.
900 ** The "fullname" field is now always present along with the "file" field,
901 even if the file cannot be found by GDB.
903 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
904 You must have the LZMA library available when configuring GDB for this
905 feature to be enabled. For more information, see:
906 http://fedoraproject.org/wiki/Features/MiniDebugInfo
911 Set the size of trace buffer. The remote stub reports support for this
912 packet to gdb's qSupported query.
915 Enable Branch Trace Store (BTS)-based branch tracing for the current
916 thread. The remote stub reports support for this packet to gdb's
920 Disable branch tracing for the current thread. The remote stub reports
921 support for this packet to gdb's qSupported query.
924 Read the traced branches for the current thread. The remote stub
925 reports support for this packet to gdb's qSupported query.
927 *** Changes in GDB 7.5
929 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
930 for more x32 ABI info.
932 * GDB now supports access to MIPS DSP registers on Linux targets.
934 * GDB now supports debugging microMIPS binaries.
936 * The "info os" command on GNU/Linux can now display information on
937 several new classes of objects managed by the operating system:
938 "info os procgroups" lists process groups
939 "info os files" lists file descriptors
940 "info os sockets" lists internet-domain sockets
941 "info os shm" lists shared-memory regions
942 "info os semaphores" lists semaphores
943 "info os msg" lists message queues
944 "info os modules" lists loaded kernel modules
946 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
947 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
948 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
949 options and inspect the probe arguments using the new $_probe_arg family
950 of convenience variables. You can obtain more information about SystemTap
951 in <http://sourceware.org/systemtap/>.
953 * GDB now supports reversible debugging on ARM, it allows you to
954 debug basic ARM and THUMB instructions, and provides
955 record/replay support.
957 * The option "symbol-reloading" has been deleted as it is no longer used.
961 ** GDB commands implemented in Python can now be put in command class
964 ** The "maint set python print-stack on|off" is now deleted.
966 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
967 apply "flag enum"-style pretty-printing to any enum.
969 ** gdb.lookup_symbol can now work when there is no current frame.
971 ** gdb.Symbol now has a 'line' attribute, holding the line number in
972 the source at which the symbol was defined.
974 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
975 method 'value'. The former indicates whether the symbol needs a
976 frame in order to compute its value, and the latter computes the
979 ** A new method 'referenced_value' on gdb.Value objects which can
980 dereference pointer as well as C++ reference values.
982 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
983 which return the global and static blocks (as gdb.Block objects),
984 of the underlying symbol table, respectively.
986 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
987 object associated with a PC value.
989 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
990 of the address range occupied by code for the current source line.
992 * Go language support.
993 GDB now supports debugging programs written in the Go programming
996 * GDBserver now supports stdio connections.
997 E.g. (gdb) target remote | ssh myhost gdbserver - hello
999 * The binary "gdbtui" can no longer be built or installed.
1000 Use "gdb -tui" instead.
1002 * GDB will now print "flag" enums specially. A flag enum is one where
1003 all the enumerator values have no bits in common when pairwise
1004 "and"ed. When printing a value whose type is a flag enum, GDB will
1005 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1006 (gdb) print (enum E) 3
1009 * The filename part of a linespec will now match trailing components
1010 of a source file name. For example, "break gcc/expr.c:1000" will
1011 now set a breakpoint in build/gcc/expr.c, but not
1012 build/libcpp/expr.c.
1014 * The "info proc" and "generate-core-file" commands will now also
1015 work on remote targets connected to GDBserver on Linux.
1017 * The command "info catch" has been removed. It has been disabled
1018 since December 2007.
1020 * The "catch exception" and "catch assert" commands now accept
1021 a condition at the end of the command, much like the "break"
1022 command does. For instance:
1024 (gdb) catch exception Constraint_Error if Barrier = True
1026 Previously, it was possible to add a condition to such catchpoints,
1027 but it had to be done as a second step, after the catchpoint had been
1028 created, using the "condition" command.
1030 * The "info static-tracepoint-marker" command will now also work on
1031 native Linux targets with in-process agent.
1033 * GDB can now set breakpoints on inlined functions.
1035 * The .gdb_index section has been updated to include symbols for
1036 inlined functions. GDB will ignore older .gdb_index sections by
1037 default, which could cause symbol files to be loaded more slowly
1038 until their .gdb_index sections can be recreated. The new command
1039 "set use-deprecated-index-sections on" will cause GDB to use any older
1040 .gdb_index sections it finds. This will restore performance, but the
1041 ability to set breakpoints on inlined functions will be lost in symbol
1042 files with older .gdb_index sections.
1044 The .gdb_index section has also been updated to record more information
1045 about each symbol. This speeds up the "info variables", "info functions"
1046 and "info types" commands when used with programs having the .gdb_index
1047 section, as well as speeding up debugging with shared libraries using
1048 the .gdb_index section.
1050 * Ada support for GDB/MI Variable Objects has been added.
1052 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1057 ** New command -info-os is the MI equivalent of "info os".
1059 ** Output logs ("set logging" and related) now include MI output.
1063 ** "set use-deprecated-index-sections on|off"
1064 "show use-deprecated-index-sections on|off"
1065 Controls the use of deprecated .gdb_index sections.
1067 ** "catch load" and "catch unload" can be used to stop when a shared
1068 library is loaded or unloaded, respectively.
1070 ** "enable count" can be used to auto-disable a breakpoint after
1073 ** "info vtbl" can be used to show the virtual method tables for
1074 C++ and Java objects.
1076 ** "explore" and its sub commands "explore value" and "explore type"
1077 can be used to recursively explore values and types of
1078 expressions. These commands are available only if GDB is
1079 configured with '--with-python'.
1081 ** "info auto-load" shows status of all kinds of auto-loaded files,
1082 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1083 sequences of commands files, "info auto-load python-scripts"
1084 shows status of auto-loading Python script files,
1085 "info auto-load local-gdbinit" shows status of loading init file
1086 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1087 status of inferior specific thread debugging shared library loading.
1089 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1090 and "show auto-load-scripts" commands have been deprecated, use their
1091 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1092 and "show auto-load python-scripts" counterparts instead.
1094 ** "dprintf location,format,args..." creates a dynamic printf, which
1095 is basically a breakpoint that does a printf and immediately
1096 resumes your program's execution, so it is like a printf that you
1097 can insert dynamically at runtime instead of at compiletime.
1099 ** "set print symbol"
1101 Controls whether GDB attempts to display the symbol, if any,
1102 corresponding to addresses it prints. This defaults to "on", but
1103 you can set it to "off" to restore GDB's previous behavior.
1105 * Deprecated commands
1107 ** For the Renesas Super-H architecture, the "regs" command has been
1108 deprecated, and "info all-registers" should be used instead.
1112 Renesas RL78 rl78-*-elf
1113 HP OpenVMS ia64 ia64-hp-openvms*
1115 * GDBserver supports evaluation of breakpoint conditions. When
1116 support is advertised by GDBserver, GDB may be told to send the
1117 breakpoint conditions in bytecode form to GDBserver. GDBserver
1118 will only report the breakpoint trigger to GDB when its condition
1123 set mips compression
1124 show mips compression
1125 Select the compressed ISA encoding used in functions that have no symbol
1126 information available. The encoding can be set to either of:
1129 and is updated automatically from ELF file flags if available.
1131 set breakpoint condition-evaluation
1132 show breakpoint condition-evaluation
1133 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1134 GDBserver ("target"). Default option "auto" chooses the most efficient
1136 This option can improve debugger efficiency depending on the speed of the
1140 Disable auto-loading globally.
1143 Show auto-loading setting of all kinds of auto-loaded files.
1145 set auto-load gdb-scripts on|off
1146 show auto-load gdb-scripts
1147 Control auto-loading of GDB canned sequences of commands files.
1149 set auto-load python-scripts on|off
1150 show auto-load python-scripts
1151 Control auto-loading of Python script files.
1153 set auto-load local-gdbinit on|off
1154 show auto-load local-gdbinit
1155 Control loading of init file (.gdbinit) from current directory.
1157 set auto-load libthread-db on|off
1158 show auto-load libthread-db
1159 Control auto-loading of inferior specific thread debugging shared library.
1161 set auto-load scripts-directory <dir1>[:<dir2>...]
1162 show auto-load scripts-directory
1163 Set a list of directories from which to load auto-loaded scripts.
1164 Automatically loaded Python scripts and GDB scripts are located in one
1165 of the directories listed by this option.
1166 The delimiter (':' above) may differ according to the host platform.
1168 set auto-load safe-path <dir1>[:<dir2>...]
1169 show auto-load safe-path
1170 Set a list of directories from which it is safe to auto-load files.
1171 The delimiter (':' above) may differ according to the host platform.
1173 set debug auto-load on|off
1174 show debug auto-load
1175 Control display of debugging info for auto-loading the files above.
1177 set dprintf-style gdb|call|agent
1179 Control the way in which a dynamic printf is performed; "gdb"
1180 requests a GDB printf command, while "call" causes dprintf to call a
1181 function in the inferior. "agent" requests that the target agent
1182 (such as GDBserver) do the printing.
1184 set dprintf-function <expr>
1185 show dprintf-function
1186 set dprintf-channel <expr>
1187 show dprintf-channel
1188 Set the function and optional first argument to the call when using
1189 the "call" style of dynamic printf.
1191 set disconnected-dprintf on|off
1192 show disconnected-dprintf
1193 Control whether agent-style dynamic printfs continue to be in effect
1194 after GDB disconnects.
1196 * New configure options
1198 --with-auto-load-dir
1199 Configure default value for the 'set auto-load scripts-directory'
1200 setting above. It defaults to '$debugdir:$datadir/auto-load',
1201 $debugdir representing global debugging info directories (available
1202 via 'show debug-file-directory') and $datadir representing GDB's data
1203 directory (available via 'show data-directory').
1205 --with-auto-load-safe-path
1206 Configure default value for the 'set auto-load safe-path' setting
1207 above. It defaults to the --with-auto-load-dir setting.
1209 --without-auto-load-safe-path
1210 Set 'set auto-load safe-path' to '/', effectively disabling this
1213 * New remote packets
1215 z0/z1 conditional breakpoints extension
1217 The z0/z1 breakpoint insertion packets have been extended to carry
1218 a list of conditional expressions over to the remote stub depending on the
1219 condition evaluation mode. The use of this extension can be controlled
1220 via the "set remote conditional-breakpoints-packet" command.
1224 Specify the signals which the remote stub may pass to the debugged
1225 program without GDB involvement.
1227 * New command line options
1229 --init-command=FILE, -ix Like --command, -x but execute it
1230 before loading inferior.
1231 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1232 execute it before loading inferior.
1234 *** Changes in GDB 7.4
1236 * GDB now handles ambiguous linespecs more consistently; the existing
1237 FILE:LINE support has been expanded to other types of linespecs. A
1238 breakpoint will now be set on all matching locations in all
1239 inferiors, and locations will be added or removed according to
1242 * GDB now allows you to skip uninteresting functions and files when
1243 stepping with the "skip function" and "skip file" commands.
1245 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1246 and "show remote hardware-watchpoint-length-limit". These allows to
1247 set or show the maximum length limit (in bytes) of a remote
1248 target hardware watchpoint.
1250 This allows e.g. to use "unlimited" hardware watchpoints with the
1251 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1252 watchpoints are slower than real hardware watchpoints but are
1253 significantly faster than gdb software watchpoints.
1257 ** The register_pretty_printer function in module gdb.printing now takes
1258 an optional `replace' argument. If True, the new printer replaces any
1261 ** The "maint set python print-stack on|off" command has been
1262 deprecated and will be deleted in GDB 7.5.
1263 A new command: "set python print-stack none|full|message" has
1264 replaced it. Additionally, the default for "print-stack" is
1265 now "message", which just prints the error message without
1268 ** A prompt substitution hook (prompt_hook) is now available to the
1271 ** A new Python module, gdb.prompt has been added to the GDB Python
1272 modules library. This module provides functionality for
1273 escape sequences in prompts (used by set/show
1274 extended-prompt). These escape sequences are replaced by their
1275 corresponding value.
1277 ** Python commands and convenience-functions located in
1278 'data-directory'/python/gdb/command and
1279 'data-directory'/python/gdb/function are now automatically loaded
1282 ** Blocks now provide four new attributes. global_block and
1283 static_block will return the global and static blocks
1284 respectively. is_static and is_global are boolean attributes
1285 that indicate if the block is one of those two types.
1287 ** Symbols now provide the "type" attribute, the type of the symbol.
1289 ** The "gdb.breakpoint" function has been deprecated in favor of
1292 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1293 of a function. This class is based on the "finish" command
1294 available in the CLI.
1296 ** Type objects for struct and union types now allow access to
1297 the fields using standard Python dictionary (mapping) methods.
1298 For example, "some_type['myfield']" now works, as does
1299 "some_type.items()".
1301 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1304 ** A new function, "deep_items" has been added to the gdb.types
1305 module in the GDB Python modules library. This function returns
1306 an iterator over the fields of a struct or union type. Unlike
1307 the standard Python "iteritems" method, it will recursively traverse
1308 any anonymous fields.
1312 ** "*stopped" events can report several new "reason"s, such as
1315 ** Breakpoint changes are now notified using new async records, like
1316 "=breakpoint-modified".
1318 ** New command -ada-task-info.
1320 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1321 $sdir specifies the default system locations of shared libraries.
1322 $pdir specifies the directory where the libpthread used by the application
1325 GDB no longer looks in $sdir and $pdir after it has searched the directories
1326 mentioned in libthread-db-search-path. If you want to search those
1327 directories, they must be specified in libthread-db-search-path.
1328 The default value of libthread-db-search-path on GNU/Linux and Solaris
1329 systems is now "$sdir:$pdir".
1331 $pdir is not supported by gdbserver, it is currently ignored.
1332 $sdir is supported by gdbserver.
1334 * New configure option --with-iconv-bin.
1335 When using the internationalization support like the one in the GNU C
1336 library, GDB will invoke the "iconv" program to get a list of supported
1337 character sets. If this program lives in a non-standard location, one can
1338 use this option to specify where to find it.
1340 * When natively debugging programs on PowerPC BookE processors running
1341 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1342 watchpoints, which specify a mask in addition to an address to watch.
1343 The mask specifies that some bits of an address (the bits which are
1344 reset in the mask) should be ignored when matching the address accessed
1345 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1346 section in the user manual for more details.
1348 * The new option --once causes GDBserver to stop listening for connections once
1349 the first connection is made. The listening port used by GDBserver will
1350 become available after that.
1352 * New commands "info macros" and "alias" have been added.
1354 * New function parameters suffix @entry specifies value of function parameter
1355 at the time the function got called. Entry values are available only since
1361 "!" is now an alias of the "shell" command.
1362 Note that no space is needed between "!" and SHELL COMMAND.
1366 watch EXPRESSION mask MASK_VALUE
1367 The watch command now supports the mask argument which allows creation
1368 of masked watchpoints, if the current architecture supports this feature.
1370 info auto-load-scripts [REGEXP]
1371 This command was formerly named "maintenance print section-scripts".
1372 It is now generally useful and is no longer a maintenance-only command.
1374 info macro [-all] [--] MACRO
1375 The info macro command has new options `-all' and `--'. The first for
1376 printing all definitions of a macro. The second for explicitly specifying
1377 the end of arguments and the beginning of the macro name in case the macro
1378 name starts with a hyphen.
1380 collect[/s] EXPRESSIONS
1381 The tracepoint collect command now takes an optional modifier "/s"
1382 that directs it to dereference pointer-to-character types and
1383 collect the bytes of memory up to a zero byte. The behavior is
1384 similar to what you see when you use the regular print command on a
1385 string. An optional integer following the "/s" sets a bound on the
1386 number of bytes that will be collected.
1389 The trace start command now interprets any supplied arguments as a
1390 note to be recorded with the trace run, with an effect similar to
1391 setting the variable trace-notes.
1394 The trace stop command now interprets any arguments as a note to be
1395 mentioned along with the tstatus report that the trace was stopped
1396 with a command. The effect is similar to setting the variable
1399 * Tracepoints can now be enabled and disabled at any time after a trace
1400 experiment has been started using the standard "enable" and "disable"
1401 commands. It is now possible to start a trace experiment with no enabled
1402 tracepoints; GDB will display a warning, but will allow the experiment to
1403 begin, assuming that tracepoints will be enabled as needed while the trace
1406 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1407 locations with 4-byte instructions, when they were previously
1408 limited to locations with instructions of 5 bytes or longer.
1412 set debug dwarf2-read
1413 show debug dwarf2-read
1414 Turns on or off display of debugging messages related to reading
1415 DWARF debug info. The default is off.
1417 set debug symtab-create
1418 show debug symtab-create
1419 Turns on or off display of debugging messages related to symbol table
1420 creation. The default is off.
1423 show extended-prompt
1424 Set the GDB prompt, and allow escape sequences to be inserted to
1425 display miscellaneous information (see 'help set extended-prompt'
1426 for the list of sequences). This prompt (and any information
1427 accessed through the escape sequences) is updated every time the
1428 prompt is displayed.
1430 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1431 show print entry-values
1432 Set printing of frame argument values at function entry. In some cases
1433 GDB can determine the value of function argument which was passed by the
1434 function caller, even if the value was modified inside the called function.
1436 set debug entry-values
1437 show debug entry-values
1438 Control display of debugging info for determining frame argument values at
1439 function entry and virtual tail call frames.
1441 set basenames-may-differ
1442 show basenames-may-differ
1443 Set whether a source file may have multiple base names.
1444 (A "base name" is the name of a file with the directory part removed.
1445 Example: The base name of "/home/user/hello.c" is "hello.c".)
1446 If set, GDB will canonicalize file names (e.g., expand symlinks)
1447 before comparing them. Canonicalization is an expensive operation,
1448 but it allows the same file be known by more than one base name.
1449 If not set (the default), all source files are assumed to have just
1450 one base name, and gdb will do file name comparisons more efficiently.
1456 Set a user name and notes for the current and any future trace runs.
1457 This is useful for long-running and/or disconnected traces, to
1458 inform others (or yourself) as to who is running the trace, supply
1459 contact information, or otherwise explain what is going on.
1461 set trace-stop-notes
1462 show trace-stop-notes
1463 Set a note attached to the trace run, that is displayed when the
1464 trace has been stopped by a tstop command. This is useful for
1465 instance as an explanation, if you are stopping a trace run that was
1466 started by someone else.
1468 * New remote packets
1472 Dynamically enable a tracepoint in a started trace experiment.
1476 Dynamically disable a tracepoint in a started trace experiment.
1480 Set the user and notes of the trace run.
1484 Query the current status of a tracepoint.
1488 Query the minimum length of instruction at which a fast tracepoint may
1491 * Dcache size (number of lines) and line-size are now runtime-configurable
1492 via "set dcache line" and "set dcache line-size" commands.
1496 Texas Instruments TMS320C6x tic6x-*-*
1500 Renesas RL78 rl78-*-elf
1502 *** Changes in GDB 7.3.1
1504 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1506 *** Changes in GDB 7.3
1508 * GDB has a new command: "thread find [REGEXP]".
1509 It finds the thread id whose name, target id, or thread extra info
1510 matches the given regular expression.
1512 * The "catch syscall" command now works on mips*-linux* targets.
1514 * The -data-disassemble MI command now supports modes 2 and 3 for
1515 dumping the instruction opcodes.
1517 * New command line options
1519 -data-directory DIR Specify DIR as the "data-directory".
1520 This is mostly for testing purposes.
1522 * The "maint set python auto-load on|off" command has been renamed to
1523 "set auto-load-scripts on|off".
1525 * GDB has a new command: "set directories".
1526 It is like the "dir" command except that it replaces the
1527 source path list instead of augmenting it.
1529 * GDB now understands thread names.
1531 On GNU/Linux, "info threads" will display the thread name as set by
1532 prctl or pthread_setname_np.
1534 There is also a new command, "thread name", which can be used to
1535 assign a name internally for GDB to display.
1538 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1539 has been integrated into GDB.
1543 ** The function gdb.Write now accepts an optional keyword 'stream'.
1544 This keyword, when provided, will direct the output to either
1545 stdout, stderr, or GDB's logging output.
1547 ** Parameters can now be be sub-classed in Python, and in particular
1548 you may implement the get_set_doc and get_show_doc functions.
1549 This improves how Parameter set/show documentation is processed
1550 and allows for more dynamic content.
1552 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1553 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1554 have an is_valid method.
1556 ** Breakpoints can now be sub-classed in Python, and in particular
1557 you may implement a 'stop' function that is executed each time
1558 the inferior reaches that breakpoint.
1560 ** New function gdb.lookup_global_symbol looks up a global symbol.
1562 ** GDB values in Python are now callable if the value represents a
1563 function. For example, if 'some_value' represents a function that
1564 takes two integer parameters and returns a value, you can call
1565 that function like so:
1567 result = some_value (10,20)
1569 ** Module gdb.types has been added.
1570 It contains a collection of utilities for working with gdb.Types objects:
1571 get_basic_type, has_field, make_enum_dict.
1573 ** Module gdb.printing has been added.
1574 It contains utilities for writing and registering pretty-printers.
1575 New classes: PrettyPrinter, SubPrettyPrinter,
1576 RegexpCollectionPrettyPrinter.
1577 New function: register_pretty_printer.
1579 ** New commands "info pretty-printers", "enable pretty-printer" and
1580 "disable pretty-printer" have been added.
1582 ** gdb.parameter("directories") is now available.
1584 ** New function gdb.newest_frame returns the newest frame in the
1587 ** The gdb.InferiorThread class has a new "name" attribute. This
1588 holds the thread's name.
1590 ** Python Support for Inferior events.
1591 Python scripts can add observers to be notified of events
1592 occurring in the process being debugged.
1593 The following events are currently supported:
1594 - gdb.events.cont Continue event.
1595 - gdb.events.exited Inferior exited event.
1596 - gdb.events.stop Signal received, and Breakpoint hit events.
1600 ** GDB now puts template parameters in scope when debugging in an
1601 instantiation. For example, if you have:
1603 template<int X> int func (void) { return X; }
1605 then if you step into func<5>, "print X" will show "5". This
1606 feature requires proper debuginfo support from the compiler; it
1607 was added to GCC 4.5.
1609 ** The motion commands "next", "finish", "until", and "advance" now
1610 work better when exceptions are thrown. In particular, GDB will
1611 no longer lose control of the inferior; instead, the GDB will
1612 stop the inferior at the point at which the exception is caught.
1613 This functionality requires a change in the exception handling
1614 code that was introduced in GCC 4.5.
1616 * GDB now follows GCC's rules on accessing volatile objects when
1617 reading or writing target state during expression evaluation.
1618 One notable difference to prior behavior is that "print x = 0"
1619 no longer generates a read of x; the value of the assignment is
1620 now always taken directly from the value being assigned.
1622 * GDB now has some support for using labels in the program's source in
1623 linespecs. For instance, you can use "advance label" to continue
1624 execution to a label.
1626 * GDB now has support for reading and writing a new .gdb_index
1627 section. This section holds a fast index of DWARF debugging
1628 information and can be used to greatly speed up GDB startup and
1629 operation. See the documentation for `save gdb-index' for details.
1631 * The "watch" command now accepts an optional "-location" argument.
1632 When used, this causes GDB to watch the memory referred to by the
1633 expression. Such a watchpoint is never deleted due to it going out
1636 * GDB now supports thread debugging of core dumps on GNU/Linux.
1638 GDB now activates thread debugging using the libthread_db library
1639 when debugging GNU/Linux core dumps, similarly to when debugging
1640 live processes. As a result, when debugging a core dump file, GDB
1641 is now able to display pthread_t ids of threads. For example, "info
1642 threads" shows the same output as when debugging the process when it
1643 was live. In earlier releases, you'd see something like this:
1646 * 1 LWP 6780 main () at main.c:10
1648 While now you see this:
1651 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1653 It is also now possible to inspect TLS variables when debugging core
1656 When debugging a core dump generated on a machine other than the one
1657 used to run GDB, you may need to point GDB at the correct
1658 libthread_db library with the "set libthread-db-search-path"
1659 command. See the user manual for more details on this command.
1661 * When natively debugging programs on PowerPC BookE processors running
1662 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1663 which stop execution of the inferior whenever it executes an instruction
1664 at any address within the specified range. See the "PowerPC Embedded"
1665 section in the user manual for more details.
1667 * New features in the GDB remote stub, GDBserver
1669 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1670 and i686 LynxOS (version 5.x).
1672 ** GDBserver is now supported on Blackfin Linux.
1674 * New native configurations
1676 ia64 HP-UX ia64-*-hpux*
1680 Analog Devices, Inc. Blackfin Processor bfin-*
1682 * Ada task switching is now supported on sparc-elf targets when
1683 debugging a program using the Ravenscar Profile. For more information,
1684 see the "Tasking Support when using the Ravenscar Profile" section
1685 in the GDB user manual.
1687 * Guile support was removed.
1689 * New features in the GNU simulator
1691 ** The --map-info flag lists all known core mappings.
1693 ** CFI flashes may be simulated via the "cfi" device.
1695 *** Changes in GDB 7.2
1697 * Shared library support for remote targets by default
1699 When GDB is configured for a generic, non-OS specific target, like
1700 for example, --target=arm-eabi or one of the many *-*-elf targets,
1701 GDB now queries remote stubs for loaded shared libraries using the
1702 `qXfer:libraries:read' packet. Previously, shared library support
1703 was always disabled for such configurations.
1707 ** Argument Dependent Lookup (ADL)
1709 In C++ ADL lookup directs function search to the namespaces of its
1710 arguments even if the namespace has not been imported.
1720 Here the compiler will search for `foo' in the namespace of 'b'
1721 and find A::foo. GDB now supports this. This construct is commonly
1722 used in the Standard Template Library for operators.
1724 ** Improved User Defined Operator Support
1726 In addition to member operators, GDB now supports lookup of operators
1727 defined in a namespace and imported with a `using' directive, operators
1728 defined in the global scope, operators imported implicitly from an
1729 anonymous namespace, and the ADL operators mentioned in the previous
1731 GDB now also supports proper overload resolution for all the previously
1732 mentioned flavors of operators.
1734 ** static const class members
1736 Printing of static const class members that are initialized in the
1737 class definition has been fixed.
1739 * Windows Thread Information Block access.
1741 On Windows targets, GDB now supports displaying the Windows Thread
1742 Information Block (TIB) structure. This structure is visible either
1743 by using the new command `info w32 thread-information-block' or, by
1744 dereferencing the new convenience variable named `$_tlb', a
1745 thread-specific pointer to the TIB. This feature is also supported
1746 when remote debugging using GDBserver.
1748 * Static tracepoints
1750 Static tracepoints are calls in the user program into a tracing
1751 library. One such library is a port of the LTTng kernel tracer to
1752 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1753 When debugging with GDBserver, GDB now supports combining the GDB
1754 tracepoint machinery with such libraries. For example: the user can
1755 use GDB to probe a static tracepoint marker (a call from the user
1756 program into the tracing library) with the new "strace" command (see
1757 "New commands" below). This creates a "static tracepoint" in the
1758 breakpoint list, that can be manipulated with the same feature set
1759 as fast and regular tracepoints. E.g., collect registers, local and
1760 global variables, collect trace state variables, and define
1761 tracepoint conditions. In addition, the user can collect extra
1762 static tracepoint marker specific data, by collecting the new
1763 $_sdata internal variable. When analyzing the trace buffer, you can
1764 inspect $_sdata like any other variable available to GDB. For more
1765 information, see the "Tracepoints" chapter in GDB user manual. New
1766 remote packets have been defined to support static tracepoints, see
1767 the "New remote packets" section below.
1769 * Better reconstruction of tracepoints after disconnected tracing
1771 GDB will attempt to download the original source form of tracepoint
1772 definitions when starting a trace run, and then will upload these
1773 upon reconnection to the target, resulting in a more accurate
1774 reconstruction of the tracepoints that are in use on the target.
1778 You can now exercise direct control over the ways that GDB can
1779 affect your program. For instance, you can disallow the setting of
1780 breakpoints, so that the program can run continuously (assuming
1781 non-stop mode). In addition, the "observer" variable is available
1782 to switch all of the different controls; in observer mode, GDB
1783 cannot affect the target's behavior at all, which is useful for
1784 tasks like diagnosing live systems in the field.
1786 * The new convenience variable $_thread holds the number of the
1789 * New remote packets
1793 Return the address of the Windows Thread Information Block of a given thread.
1797 In response to several of the tracepoint packets, the target may now
1798 also respond with a number of intermediate `qRelocInsn' request
1799 packets before the final result packet, to have GDB handle
1800 relocating an instruction to execute at a different address. This
1801 is particularly useful for stubs that support fast tracepoints. GDB
1802 reports support for this feature in the qSupported packet.
1806 List static tracepoint markers in the target program.
1810 List static tracepoint markers at a given address in the target
1813 qXfer:statictrace:read
1815 Read the static trace data collected (by a `collect $_sdata'
1816 tracepoint action). The remote stub reports support for this packet
1817 to gdb's qSupported query.
1821 Send the current settings of GDB's permission flags.
1825 Send part of the source (textual) form of a tracepoint definition,
1826 which includes location, conditional, and action list.
1828 * The source command now accepts a -s option to force searching for the
1829 script in the source search path even if the script name specifies
1832 * New features in the GDB remote stub, GDBserver
1834 - GDBserver now support tracepoints (including fast tracepoints, and
1835 static tracepoints). The feature is currently supported by the
1836 i386-linux and amd64-linux builds. See the "Tracepoints support
1837 in gdbserver" section in the manual for more information.
1839 GDBserver JIT compiles the tracepoint's conditional agent
1840 expression bytecode into native code whenever possible for low
1841 overhead dynamic tracepoints conditionals. For such tracepoints,
1842 an expression that examines program state is evaluated when the
1843 tracepoint is reached, in order to determine whether to capture
1844 trace data. If the condition is simple and false, processing the
1845 tracepoint finishes very quickly and no data is gathered.
1847 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1848 for static tracepoints support.
1850 - GDBserver now supports x86_64 Windows 64-bit debugging.
1852 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1853 it understands register description.
1855 * The --batch flag now disables pagination and queries.
1857 * X86 general purpose registers
1859 GDB now supports reading/writing byte, word and double-word x86
1860 general purpose registers directly. This means you can use, say,
1861 $ah or $ax to refer, respectively, to the byte register AH and
1862 16-bit word register AX that are actually portions of the 32-bit
1863 register EAX or 64-bit register RAX.
1865 * The `commands' command now accepts a range of breakpoints to modify.
1866 A plain `commands' following a command that creates multiple
1867 breakpoints affects all the breakpoints set by that command. This
1868 applies to breakpoints set by `rbreak', and also applies when a
1869 single `break' command creates multiple breakpoints (e.g.,
1870 breakpoints on overloaded c++ functions).
1872 * The `rbreak' command now accepts a filename specification as part of
1873 its argument, limiting the functions selected by the regex to those
1874 in the specified file.
1876 * Support for remote debugging Windows and SymbianOS shared libraries
1877 from Unix hosts has been improved. Non Windows GDB builds now can
1878 understand target reported file names that follow MS-DOS based file
1879 system semantics, such as file names that include drive letters and
1880 use the backslash character as directory separator. This makes it
1881 possible to transparently use the "set sysroot" and "set
1882 solib-search-path" on Unix hosts to point as host copies of the
1883 target's shared libraries. See the new command "set
1884 target-file-system-kind" described below, and the "Commands to
1885 specify files" section in the user manual for more information.
1889 eval template, expressions...
1890 Convert the values of one or more expressions under the control
1891 of the string template to a command line, and call it.
1893 set target-file-system-kind unix|dos-based|auto
1894 show target-file-system-kind
1895 Set or show the assumed file system kind for target reported file
1898 save breakpoints <filename>
1899 Save all current breakpoint definitions to a file suitable for use
1900 in a later debugging session. To read the saved breakpoint
1901 definitions, use the `source' command.
1903 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1906 info static-tracepoint-markers
1907 Display information about static tracepoint markers in the target.
1909 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1910 Define a static tracepoint by probing a marker at the given
1911 function, line, address, or marker ID.
1915 Enable and disable observer mode.
1917 set may-write-registers on|off
1918 set may-write-memory on|off
1919 set may-insert-breakpoints on|off
1920 set may-insert-tracepoints on|off
1921 set may-insert-fast-tracepoints on|off
1922 set may-interrupt on|off
1923 Set individual permissions for GDB effects on the target. Note that
1924 some of these settings can have undesirable or surprising
1925 consequences, particularly when changed in the middle of a session.
1926 For instance, disabling the writing of memory can prevent
1927 breakpoints from being inserted, cause single-stepping to fail, or
1928 even crash your program, if you disable after breakpoints have been
1929 inserted. However, GDB should not crash.
1931 set record memory-query on|off
1932 show record memory-query
1933 Control whether to stop the inferior if memory changes caused
1934 by an instruction cannot be recorded.
1939 The disassemble command now supports "start,+length" form of two arguments.
1943 ** GDB now provides a new directory location, called the python directory,
1944 where Python scripts written for GDB can be installed. The location
1945 of that directory is <data-directory>/python, where <data-directory>
1946 is the GDB data directory. For more details, see section `Scripting
1947 GDB using Python' in the manual.
1949 ** The GDB Python API now has access to breakpoints, symbols, symbol
1950 tables, program spaces, inferiors, threads and frame's code blocks.
1951 Additionally, GDB Parameters can now be created from the API, and
1952 manipulated via set/show in the CLI.
1954 ** New functions gdb.target_charset, gdb.target_wide_charset,
1955 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1957 ** New exception gdb.GdbError.
1959 ** Pretty-printers are now also looked up in the current program space.
1961 ** Pretty-printers can now be individually enabled and disabled.
1963 ** GDB now looks for names of Python scripts to auto-load in a
1964 special section named `.debug_gdb_scripts', in addition to looking
1965 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1967 * Tracepoint actions were unified with breakpoint commands. In particular,
1968 there are no longer differences in "info break" output for breakpoints and
1969 tracepoints and the "commands" command can be used for both tracepoints and
1970 regular breakpoints.
1974 ARM Symbian arm*-*-symbianelf*
1976 * D language support.
1977 GDB now supports debugging programs written in the D programming
1980 * GDB now supports the extended ptrace interface for PowerPC which is
1981 available since Linux kernel version 2.6.34. This automatically enables
1982 any hardware breakpoints and additional hardware watchpoints available in
1983 the processor. The old ptrace interface exposes just one hardware
1984 watchpoint and no hardware breakpoints.
1986 * GDB is now able to use the Data Value Compare (DVC) register available on
1987 embedded PowerPC processors to implement in hardware simple watchpoint
1988 conditions of the form:
1990 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1992 This works in native GDB running on Linux kernels with the extended ptrace
1993 interface mentioned above.
1995 *** Changes in GDB 7.1
1999 ** Namespace Support
2001 GDB now supports importing of namespaces in C++. This enables the
2002 user to inspect variables from imported namespaces. Support for
2003 namepace aliasing has also been added. So, if a namespace is
2004 aliased in the current scope (e.g. namepace C=A; ) the user can
2005 print variables using the alias (e.g. (gdb) print C::x).
2009 All known bugs relating to the printing of virtual base class were
2010 fixed. It is now possible to call overloaded static methods using a
2015 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2016 and reinterpret_cast<> are now handled by the C++ expression parser.
2020 Xilinx MicroBlaze microblaze-*-*
2025 Xilinx MicroBlaze microblaze
2028 * Multi-program debugging.
2030 GDB now has support for multi-program (a.k.a. multi-executable or
2031 multi-exec) debugging. This allows for debugging multiple inferiors
2032 simultaneously each running a different program under the same GDB
2033 session. See "Debugging Multiple Inferiors and Programs" in the
2034 manual for more information. This implied some user visible changes
2035 in the multi-inferior support. For example, "info inferiors" now
2036 lists inferiors that are not running yet or that have exited
2037 already. See also "New commands" and "New options" below.
2039 * New tracing features
2041 GDB's tracepoint facility now includes several new features:
2043 ** Trace state variables
2045 GDB tracepoints now include support for trace state variables, which
2046 are variables managed by the target agent during a tracing
2047 experiment. They are useful for tracepoints that trigger each
2048 other, so for instance one tracepoint can count hits in a variable,
2049 and then a second tracepoint has a condition that is true when the
2050 count reaches a particular value. Trace state variables share the
2051 $-syntax of GDB convenience variables, and can appear in both
2052 tracepoint actions and condition expressions. Use the "tvariable"
2053 command to create, and "info tvariables" to view; see "Trace State
2054 Variables" in the manual for more detail.
2058 GDB now includes an option for defining fast tracepoints, which
2059 targets may implement more efficiently, such as by installing a jump
2060 into the target agent rather than a trap instruction. The resulting
2061 speedup can be by two orders of magnitude or more, although the
2062 tradeoff is that some program locations on some target architectures
2063 might not allow fast tracepoint installation, for instance if the
2064 instruction to be replaced is shorter than the jump. To request a
2065 fast tracepoint, use the "ftrace" command, with syntax identical to
2066 the regular trace command.
2068 ** Disconnected tracing
2070 It is now possible to detach GDB from the target while it is running
2071 a trace experiment, then reconnect later to see how the experiment
2072 is going. In addition, a new variable disconnected-tracing lets you
2073 tell the target agent whether to continue running a trace if the
2074 connection is lost unexpectedly.
2078 GDB now has the ability to save the trace buffer into a file, and
2079 then use that file as a target, similarly to you can do with
2080 corefiles. You can select trace frames, print data that was
2081 collected in them, and use tstatus to display the state of the
2082 tracing run at the moment that it was saved. To create a trace
2083 file, use "tsave <filename>", and to use it, do "target tfile
2086 ** Circular trace buffer
2088 You can ask the target agent to handle the trace buffer as a
2089 circular buffer, discarding the oldest trace frames to make room for
2090 newer ones, by setting circular-trace-buffer to on. This feature may
2091 not be available for all target agents.
2096 The disassemble command, when invoked with two arguments, now requires
2097 the arguments to be comma-separated.
2100 The info variables command now displays variable definitions. Files
2101 which only declare a variable are not shown.
2104 The source command is now capable of sourcing Python scripts.
2105 This feature is dependent on the debugger being build with Python
2108 Related to this enhancement is also the introduction of a new command
2109 "set script-extension" (see below).
2111 * New commands (for set/show, see "New options" below)
2113 record save [<FILENAME>]
2114 Save a file (in core file format) containing the process record
2115 execution log for replay debugging at a later time.
2117 record restore <FILENAME>
2118 Restore the process record execution log that was saved at an
2119 earlier time, for replay debugging.
2121 add-inferior [-copies <N>] [-exec <FILENAME>]
2124 clone-inferior [-copies <N>] [ID]
2125 Make a new inferior ready to execute the same program another
2126 inferior has loaded.
2131 maint info program-spaces
2132 List the program spaces loaded into GDB.
2134 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2135 show remote interrupt-sequence
2136 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2137 as the sequence to the remote target in order to interrupt the execution.
2138 Ctrl-C is a default. Some system prefers BREAK which is high level of
2139 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2140 Magic SysRq g. It is BREAK signal and character 'g'.
2142 set remote interrupt-on-connect [on | off]
2143 show remote interrupt-on-connect
2144 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2145 remote target when gdb connects to it. This is needed when you debug
2148 set remotebreak [on | off]
2150 Deprecated. Use "set/show remote interrupt-sequence" instead.
2152 tvariable $NAME [ = EXP ]
2153 Create or modify a trace state variable.
2156 List trace state variables and their values.
2158 delete tvariable $NAME ...
2159 Delete one or more trace state variables.
2162 Evaluate the given expressions without collecting anything into the
2163 trace buffer. (Valid in tracepoint actions only.)
2165 ftrace FN / FILE:LINE / *ADDR
2166 Define a fast tracepoint at the given function, line, or address.
2168 * New expression syntax
2170 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2171 GDB now parses 0b101010 identically with 42.
2175 set follow-exec-mode new|same
2176 show follow-exec-mode
2177 Control whether GDB reuses the same inferior across an exec call or
2178 creates a new one. This is useful to be able to restart the old
2179 executable after the inferior having done an exec call.
2181 set default-collect EXPR, ...
2182 show default-collect
2183 Define a list of expressions to be collected at each tracepoint.
2184 This is a useful way to ensure essential items are not overlooked,
2185 such as registers or a critical global variable.
2187 set disconnected-tracing
2188 show disconnected-tracing
2189 If set to 1, the target is instructed to continue tracing if it
2190 loses its connection to GDB. If 0, the target is to stop tracing
2193 set circular-trace-buffer
2194 show circular-trace-buffer
2195 If set to on, the target is instructed to use a circular trace buffer
2196 and discard the oldest trace frames instead of stopping the trace due
2197 to a full trace buffer. If set to off, the trace stops when the buffer
2198 fills up. Some targets may not support this.
2200 set script-extension off|soft|strict
2201 show script-extension
2202 If set to "off", the debugger does not perform any script language
2203 recognition, and all sourced files are assumed to be GDB scripts.
2204 If set to "soft" (the default), files are sourced according to
2205 filename extension, falling back to GDB scripts if the first
2207 If set to "strict", files are sourced according to filename extension.
2209 set ada trust-PAD-over-XVS on|off
2210 show ada trust-PAD-over-XVS
2211 If off, activate a workaround against a bug in the debugging information
2212 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2213 the GCC sources for more information about the GNAT encoding and
2214 PAD types in particular). It is always safe to set this option to
2215 off, but this introduces a slight performance penalty. The default
2218 * Python API Improvements
2220 ** GDB provides the new class gdb.LazyString. This is useful in
2221 some pretty-printing cases. The new method gdb.Value.lazy_string
2222 provides a simple way to create objects of this type.
2224 ** The fields returned by gdb.Type.fields now have an
2225 `is_base_class' attribute.
2227 ** The new method gdb.Type.range returns the range of an array type.
2229 ** The new method gdb.parse_and_eval can be used to parse and
2230 evaluate an expression.
2232 * New remote packets
2235 Define a trace state variable.
2238 Get the current value of a trace state variable.
2241 Set desired tracing behavior upon disconnection.
2244 Set the trace buffer to be linear or circular.
2247 Get data about the tracepoints currently in use.
2251 Process record now works correctly with hardware watchpoints.
2253 Multiple bug fixes have been made to the mips-irix port, making it
2254 much more reliable. In particular:
2255 - Debugging threaded applications is now possible again. Previously,
2256 GDB would hang while starting the program, or while waiting for
2257 the program to stop at a breakpoint.
2258 - Attaching to a running process no longer hangs.
2259 - An error occurring while loading a core file has been fixed.
2260 - Changing the value of the PC register now works again. This fixes
2261 problems observed when using the "jump" command, or when calling
2262 a function from GDB, or even when assigning a new value to $pc.
2263 - With the "finish" and "return" commands, the return value for functions
2264 returning a small array is now correctly printed.
2265 - It is now possible to break on shared library code which gets executed
2266 during a shared library init phase (code executed while executing
2267 their .init section). Previously, the breakpoint would have no effect.
2268 - GDB is now able to backtrace through the signal handler for
2269 non-threaded programs.
2271 PIE (Position Independent Executable) programs debugging is now supported.
2272 This includes debugging execution of PIC (Position Independent Code) shared
2273 libraries although for that, it should be possible to run such libraries as an
2276 *** Changes in GDB 7.0
2278 * GDB now has an interface for JIT compilation. Applications that
2279 dynamically generate code can create symbol files in memory and register
2280 them with GDB. For users, the feature should work transparently, and
2281 for JIT developers, the interface is documented in the GDB manual in the
2282 "JIT Compilation Interface" chapter.
2284 * Tracepoints may now be conditional. The syntax is as for
2285 breakpoints; either an "if" clause appended to the "trace" command,
2286 or the "condition" command is available. GDB sends the condition to
2287 the target for evaluation using the same bytecode format as is used
2288 for tracepoint actions.
2290 * The disassemble command now supports: an optional /r modifier, print the
2291 raw instructions in hex as well as in symbolic form, and an optional /m
2292 modifier to print mixed source+assembly.
2294 * Process record and replay
2296 In a architecture environment that supports ``process record and
2297 replay'', ``process record and replay'' target can record a log of
2298 the process execution, and replay it with both forward and reverse
2301 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2302 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2303 set execution-direction {forward|reverse}, for targets that support
2306 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2307 feature is available with a native GDB running on kernel version
2310 * GDB now has support for multi-byte and wide character sets on the
2311 target. Strings whose character type is wchar_t, char16_t, or
2312 char32_t are now correctly printed. GDB supports wide- and unicode-
2313 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2314 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2315 `printf'. This feature requires iconv to work properly; if your
2316 system does not have a working iconv, GDB can use GNU libiconv. See
2317 the installation instructions for more information.
2319 * GDB now supports automatic retrieval of shared library files from
2320 remote targets. To use this feature, specify a system root that begins
2321 with the `remote:' prefix, either via the `set sysroot' command or via
2322 the `--with-sysroot' configure-time option.
2324 * "info sharedlibrary" now takes an optional regex of libraries to show,
2325 and it now reports if a shared library has no debugging information.
2327 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2328 now complete on file names.
2330 * When completing in expressions, gdb will attempt to limit
2331 completions to allowable structure or union fields, where appropriate.
2332 For instance, consider:
2334 # struct example { int f1; double f2; };
2335 # struct example variable;
2338 If the user types TAB at the end of this command line, the available
2339 completions will be "f1" and "f2".
2341 * Inlined functions are now supported. They show up in backtraces, and
2342 the "step", "next", and "finish" commands handle them automatically.
2344 * GDB now supports the token-splicing (##) and stringification (#)
2345 operators when expanding macros. It also supports variable-arity
2348 * GDB now supports inspecting extra signal information, exported by
2349 the new $_siginfo convenience variable. The feature is currently
2350 implemented on linux ARM, i386 and amd64.
2352 * GDB can now display the VFP floating point registers and NEON vector
2353 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2354 can provide these registers (requires Linux 2.6.30 or later). Remote
2355 and simulator targets may also provide them.
2357 * New remote packets
2360 Search memory for a sequence of bytes.
2363 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2364 operation over reliable transport links. Use of this packet is
2365 controlled by the `set remote noack-packet' command.
2368 Kill the process with the specified process ID. Use this in preference
2369 to `k' when multiprocess protocol extensions are supported.
2372 Obtains additional operating system information
2376 Read or write additional signal information.
2378 * Removed remote protocol undocumented extension
2380 An undocumented extension to the remote protocol's `S' stop reply
2381 packet that permited the stub to pass a process id was removed.
2382 Remote servers should use the `T' stop reply packet instead.
2384 * GDB now supports multiple function calling conventions according to the
2385 DWARF-2 DW_AT_calling_convention function attribute.
2387 * The SH target utilizes the aforementioned change to distinguish between gcc
2388 and Renesas calling convention. It also adds the new CLI commands
2389 `set/show sh calling-convention'.
2391 * GDB can now read compressed debug sections, as produced by GNU gold
2392 with the --compress-debug-sections=zlib flag.
2394 * 64-bit core files are now supported on AIX.
2396 * Thread switching is now supported on Tru64.
2398 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2399 which will be allocated using malloc later in program execution.
2401 * The qXfer:libraries:read remote procotol packet now allows passing a
2402 list of section offsets.
2404 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2405 conditions handling signals delivered during attach or thread creation
2406 have also been fixed.
2408 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2409 From the user's standpoint, all unqualified instances of True and False
2410 are treated as the standard definitions, regardless of context.
2412 * GDB now parses C++ symbol and type names more flexibly. For
2415 template<typename T> class C { };
2418 GDB will now correctly handle all of:
2420 ptype C<char const *>
2421 ptype C<char const*>
2422 ptype C<const char *>
2423 ptype C<const char*>
2425 * New features in the GDB remote stub, gdbserver
2427 - The "--wrapper" command-line argument tells gdbserver to use a
2428 wrapper program to launch programs for debugging.
2430 - On PowerPC and S/390 targets, it is now possible to use a single
2431 gdbserver executable to debug both 32-bit and 64-bit programs.
2432 (This requires gdbserver itself to be built as a 64-bit executable.)
2434 - gdbserver uses the new noack protocol mode for TCP connections to
2435 reduce communications latency, if also supported and enabled in GDB.
2437 - Support for the sparc64-linux-gnu target is now included in
2440 - The amd64-linux build of gdbserver now supports debugging both
2441 32-bit and 64-bit programs.
2443 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2444 now support hardware watchpoints, and will use them automatically
2449 GDB now has support for scripting using Python. Whether this is
2450 available is determined at configure time.
2452 New GDB commands can now be written in Python.
2454 * Ada tasking support
2456 Ada tasks can now be inspected in GDB. The following commands have
2460 Print the list of Ada tasks.
2462 Print detailed information about task number N.
2464 Print the task number of the current task.
2466 Switch the context of debugging to task number N.
2468 * Support for user-defined prefixed commands. The "define" command can
2469 add new commands to existing prefixes, e.g. "target".
2471 * Multi-inferior, multi-process debugging.
2473 GDB now has generalized support for multi-inferior debugging. See
2474 "Debugging Multiple Inferiors" in the manual for more information.
2475 Although availability still depends on target support, the command
2476 set is more uniform now. The GNU/Linux specific multi-forks support
2477 has been migrated to this new framework. This implied some user
2478 visible changes; see "New commands" and also "Removed commands"
2481 * Target descriptions can now describe the target OS ABI. See the
2482 "Target Description Format" section in the user manual for more
2485 * Target descriptions can now describe "compatible" architectures
2486 to indicate that the target can execute applications for a different
2487 architecture in addition to those for the main target architecture.
2488 See the "Target Description Format" section in the user manual for
2491 * Multi-architecture debugging.
2493 GDB now includes general supports for debugging applications on
2494 hybrid systems that use more than one single processor architecture
2495 at the same time. Each such hybrid architecture still requires
2496 specific support to be added. The only hybrid architecture supported
2497 in this version of GDB is the Cell Broadband Engine.
2499 * GDB now supports integrated debugging of Cell/B.E. applications that
2500 use both the PPU and SPU architectures. To enable support for hybrid
2501 Cell/B.E. debugging, you need to configure GDB to support both the
2502 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2503 --enable-targets configure option.
2505 * Non-stop mode debugging.
2507 For some targets, GDB now supports an optional mode of operation in
2508 which you can examine stopped threads while other threads continue
2509 to execute freely. This is referred to as non-stop mode, with the
2510 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2511 section in the user manual for more information.
2513 To be able to support remote non-stop debugging, a remote stub needs
2514 to implement the non-stop mode remote protocol extensions, as
2515 described in the "Remote Non-Stop" section of the user manual. The
2516 GDB remote stub, gdbserver, has been adjusted to support these
2517 extensions on linux targets.
2519 * New commands (for set/show, see "New options" below)
2521 catch syscall [NAME(S) | NUMBER(S)]
2522 Catch system calls. Arguments, which should be names of system
2523 calls or their numbers, mean catch only those syscalls. Without
2524 arguments, every syscall will be caught. When the inferior issues
2525 any of the specified syscalls, GDB will stop and announce the system
2526 call, both when it is called and when its call returns. This
2527 feature is currently available with a native GDB running on the
2528 Linux Kernel, under the following architectures: x86, x86_64,
2529 PowerPC and PowerPC64.
2531 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2533 Search memory for a sequence of bytes.
2535 maint set python print-stack
2536 maint show python print-stack
2537 Show a stack trace when an error is encountered in a Python script.
2540 Invoke CODE by passing it to the Python interpreter.
2545 These allow macros to be defined, undefined, and listed
2549 Show operating system information about processes.
2552 List the inferiors currently under GDB's control.
2555 Switch focus to inferior number NUM.
2558 Detach from inferior number NUM.
2561 Kill inferior number NUM.
2565 set spu stop-on-load
2566 show spu stop-on-load
2567 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2569 set spu auto-flush-cache
2570 show spu auto-flush-cache
2571 Control whether to automatically flush the software-managed cache
2572 during Cell/B.E. debugging.
2574 set sh calling-convention
2575 show sh calling-convention
2576 Control the calling convention used when calling SH target functions.
2579 show debug timestamp
2580 Control display of timestamps with GDB debugging output.
2582 set disassemble-next-line
2583 show disassemble-next-line
2584 Control display of disassembled source lines or instructions when
2587 set remote noack-packet
2588 show remote noack-packet
2589 Set/show the use of remote protocol QStartNoAckMode packet. See above
2590 under "New remote packets."
2592 set remote query-attached-packet
2593 show remote query-attached-packet
2594 Control use of remote protocol `qAttached' (query-attached) packet.
2596 set remote read-siginfo-object
2597 show remote read-siginfo-object
2598 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2601 set remote write-siginfo-object
2602 show remote write-siginfo-object
2603 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2606 set remote reverse-continue
2607 show remote reverse-continue
2608 Control use of remote protocol 'bc' (reverse-continue) packet.
2610 set remote reverse-step
2611 show remote reverse-step
2612 Control use of remote protocol 'bs' (reverse-step) packet.
2614 set displaced-stepping
2615 show displaced-stepping
2616 Control displaced stepping mode. Displaced stepping is a way to
2617 single-step over breakpoints without removing them from the debuggee.
2618 Also known as "out-of-line single-stepping".
2621 show debug displaced
2622 Control display of debugging info for displaced stepping.
2624 maint set internal-error
2625 maint show internal-error
2626 Control what GDB does when an internal error is detected.
2628 maint set internal-warning
2629 maint show internal-warning
2630 Control what GDB does when an internal warning is detected.
2635 Use a wrapper program to launch programs for debugging.
2637 set multiple-symbols (all|ask|cancel)
2638 show multiple-symbols
2639 The value of this variable can be changed to adjust the debugger behavior
2640 when an expression or a breakpoint location contains an ambiguous symbol
2641 name (an overloaded function name, for instance).
2643 set breakpoint always-inserted
2644 show breakpoint always-inserted
2645 Keep breakpoints always inserted in the target, as opposed to inserting
2646 them when resuming the target, and removing them when the target stops.
2647 This option can improve debugger performance on slow remote targets.
2649 set arm fallback-mode (arm|thumb|auto)
2650 show arm fallback-mode
2651 set arm force-mode (arm|thumb|auto)
2653 These commands control how ARM GDB determines whether instructions
2654 are ARM or Thumb. The default for both settings is auto, which uses
2655 the current CPSR value for instructions without symbols; previous
2656 versions of GDB behaved as if "set arm fallback-mode arm".
2658 set disable-randomization
2659 show disable-randomization
2660 Standalone programs run with the virtual address space randomization enabled
2661 by default on some platforms. This option keeps the addresses stable across
2662 multiple debugging sessions.
2666 Control whether other threads are stopped or not when some thread hits
2671 Requests that asynchronous execution is enabled in the target, if available.
2672 In this case, it's possible to resume target in the background, and interact
2673 with GDB while the target is running. "show target-async" displays the
2674 current state of asynchronous execution of the target.
2676 set target-wide-charset
2677 show target-wide-charset
2678 The target-wide-charset is the name of the character set that GDB
2679 uses when printing characters whose type is wchar_t.
2681 set tcp auto-retry (on|off)
2683 set tcp connect-timeout
2684 show tcp connect-timeout
2685 These commands allow GDB to retry failed TCP connections to a remote stub
2686 with a specified timeout period; this is useful if the stub is launched
2687 in parallel with GDB but may not be ready to accept connections immediately.
2689 set libthread-db-search-path
2690 show libthread-db-search-path
2691 Control list of directories which GDB will search for appropriate
2694 set schedule-multiple (on|off)
2695 show schedule-multiple
2696 Allow GDB to resume all threads of all processes or only threads of
2697 the current process.
2701 Use more aggressive caching for accesses to the stack. This improves
2702 performance of remote debugging (particularly backtraces) without
2703 affecting correctness.
2705 set interactive-mode (on|off|auto)
2706 show interactive-mode
2707 Control whether GDB runs in interactive mode (on) or not (off).
2708 When in interactive mode, GDB waits for the user to answer all
2709 queries. Otherwise, GDB does not wait and assumes the default
2710 answer. When set to auto (the default), GDB determines which
2711 mode to use based on the stdin settings.
2716 For program forks, this is replaced by the new more generic `info
2717 inferiors' command. To list checkpoints, you can still use the
2718 `info checkpoints' command, which was an alias for the `info forks'
2722 Replaced by the new `inferior' command. To switch between
2723 checkpoints, you can still use the `restart' command, which was an
2724 alias for the `fork' command.
2727 This is removed, since some targets don't have a notion of
2728 processes. To switch between processes, you can still use the
2729 `inferior' command using GDB's own inferior number.
2732 For program forks, this is replaced by the new more generic `kill
2733 inferior' command. To delete a checkpoint, you can still use the
2734 `delete checkpoint' command, which was an alias for the `delete
2738 For program forks, this is replaced by the new more generic `detach
2739 inferior' command. To detach a checkpoint, you can still use the
2740 `detach checkpoint' command, which was an alias for the `detach
2743 * New native configurations
2745 x86/x86_64 Darwin i[34567]86-*-darwin*
2747 x86_64 MinGW x86_64-*-mingw*
2751 Lattice Mico32 lm32-*
2752 x86 DICOS i[34567]86-*-dicos*
2753 x86_64 DICOS x86_64-*-dicos*
2756 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2757 (mingw32ce) debugging.
2763 These commands were actually not implemented on any target.
2765 *** Changes in GDB 6.8
2767 * New native configurations
2769 NetBSD/hppa hppa*-*netbsd*
2770 Xtensa GNU/Linux xtensa*-*-linux*
2774 NetBSD/hppa hppa*-*-netbsd*
2775 Xtensa GNU/Lunux xtensa*-*-linux*
2777 * Change in command line behavior -- corefiles vs. process ids.
2779 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2780 attaching to process NUMBER fails, GDB no longer attempts to open a
2781 core file named NUMBER. Attaching to a program using the -c option
2782 is no longer supported. Instead, use the '-p' or '--pid' options.
2784 * GDB can now be built as a native debugger for debugging Windows x86
2785 (mingw32) Portable Executable (PE) programs.
2787 * Pending breakpoints no longer change their number when their address
2790 * GDB now supports breakpoints with multiple locations,
2791 including breakpoints on C++ constructors, inside C++ templates,
2792 and in inlined functions.
2794 * GDB's ability to debug optimized code has been improved. GDB more
2795 accurately identifies function bodies and lexical blocks that occupy
2796 more than one contiguous range of addresses.
2798 * Target descriptions can now describe registers for PowerPC.
2800 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2801 registers on PowerPC targets.
2803 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2804 targets even when the libthread_db library is not available.
2806 * The GDB remote stub, gdbserver, now supports the new file transfer
2807 commands (remote put, remote get, and remote delete).
2809 * The GDB remote stub, gdbserver, now supports run and attach in
2810 extended-remote mode.
2812 * hppa*64*-*-hpux11* target broken
2813 The debugger is unable to start a program and fails with the following
2814 error: "Error trying to get information about dynamic linker".
2815 The gdb-6.7 release is also affected.
2817 * GDB now supports the --enable-targets= configure option to allow
2818 building a single GDB executable that supports multiple remote
2819 target architectures.
2821 * GDB now supports debugging C and C++ programs which use the
2822 Decimal Floating Point extension. In addition, the PowerPC target
2823 now has a set of pseudo-registers to inspect decimal float values
2824 stored in two consecutive float registers.
2826 * The -break-insert MI command can optionally create pending
2829 * Improved support for debugging Ada
2830 Many improvements to the Ada language support have been made. These
2832 - Better support for Ada2005 interface types
2833 - Improved handling of arrays and slices in general
2834 - Better support for Taft-amendment types
2835 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2837 - Improved command completion in Ada
2840 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2845 set print frame-arguments (all|scalars|none)
2846 show print frame-arguments
2847 The value of this variable can be changed to control which argument
2848 values should be printed by the debugger when displaying a frame.
2853 Transfer files to and from a remote target, and delete remote files.
2860 Transfer files to and from a remote target, and delete remote files.
2862 * New remote packets
2869 Open, close, read, write, and delete files on the remote system.
2872 Attach to an existing process on the remote system, in extended-remote
2876 Run a new process on the remote system, in extended-remote mode.
2878 *** Changes in GDB 6.7
2880 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2881 bfd, libiberty and opcodes, as revealed by static analysis donated by
2882 Coverity, Inc. (http://scan.coverity.com).
2884 * When looking up multiply-defined global symbols, GDB will now prefer the
2885 symbol definition in the current shared library if it was built using the
2886 -Bsymbolic linker option.
2888 * When the Text User Interface (TUI) is not configured, GDB will now
2889 recognize the -tui command-line option and print a message that the TUI
2892 * The GDB remote stub, gdbserver, now has lower overhead for high
2893 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2895 * GDB for MIPS targets now autodetects whether a remote target provides
2896 32-bit or 64-bit register values.
2898 * Support for C++ member pointers has been improved.
2900 * GDB now understands XML target descriptions, which specify the
2901 target's overall architecture. GDB can read a description from
2902 a local file or over the remote serial protocol.
2904 * Vectors of single-byte data use a new integer type which is not
2905 automatically displayed as character or string data.
2907 * The /s format now works with the print command. It displays
2908 arrays of single-byte integers and pointers to single-byte integers
2911 * Target descriptions can now describe target-specific registers,
2912 for architectures which have implemented the support (currently
2913 only ARM, M68K, and MIPS).
2915 * GDB and the GDB remote stub, gdbserver, now support the XScale
2918 * The GDB remote stub, gdbserver, has been updated to support
2919 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2920 has been rewritten to use the standard GDB remote protocol.
2922 * GDB can now step into C++ functions which are called through thunks.
2924 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2926 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2927 layout. It also supports a TextSeg= and DataSeg= response when only
2928 segment base addresses (rather than offsets) are available.
2930 * The /i format now outputs any trailing branch delay slot instructions
2931 immediately following the last instruction within the count specified.
2933 * The GDB remote protocol "T" stop reply packet now supports a
2934 "library" response. Combined with the new "qXfer:libraries:read"
2935 packet, this response allows GDB to debug shared libraries on targets
2936 where the operating system manages the list of loaded libraries (e.g.
2937 Windows and SymbianOS).
2939 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2940 (DLLs) on Windows and Windows CE targets.
2942 * GDB now supports a faster verification that a .debug file matches its binary
2943 according to its build-id signature, if the signature is present.
2949 Enable or disable hardware flow control (RTS/CTS) on the serial port
2950 when debugging using remote targets.
2952 set mem inaccessible-by-default
2953 show mem inaccessible-by-default
2954 If the target supplies a memory map, for instance via the remote
2955 protocol's "qXfer:memory-map:read" packet, setting this variable
2956 prevents GDB from accessing memory outside the memory map. This
2957 is useful for targets with memory mapped registers or which react
2958 badly to accesses of unmapped address space.
2960 set breakpoint auto-hw
2961 show breakpoint auto-hw
2962 If the target supplies a memory map, for instance via the remote
2963 protocol's "qXfer:memory-map:read" packet, setting this variable
2964 lets GDB use hardware breakpoints automatically for memory regions
2965 where it can not use software breakpoints. This covers both the
2966 "break" command and internal breakpoints used for other commands
2967 including "next" and "finish".
2970 catch exception unhandled
2971 Stop the program execution when Ada exceptions are raised.
2974 Stop the program execution when an Ada assertion failed.
2978 Set an alternate system root for target files. This is a more
2979 general version of "set solib-absolute-prefix", which is now
2980 an alias to "set sysroot".
2983 Provide extended SPU facility status information. This set of
2984 commands is available only when debugging the Cell/B.E. SPU
2987 * New native configurations
2989 OpenBSD/sh sh*-*openbsd*
2992 unset tdesc filename
2994 Use the specified local file as an XML target description, and do
2995 not query the target for its built-in description.
2999 OpenBSD/sh sh*-*-openbsd*
3000 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3001 Toshiba Media Processor mep-elf
3003 * New remote packets
3006 Ignore the specified signals; pass them directly to the debugged program
3007 without stopping other threads or reporting them to GDB.
3009 qXfer:features:read:
3010 Read an XML target description from the target, which describes its
3015 Read or write contents of an spufs file on the target system. These
3016 packets are available only on the Cell/B.E. SPU architecture.
3018 qXfer:libraries:read:
3019 Report the loaded shared libraries. Combined with new "T" packet
3020 response, this packet allows GDB to debug shared libraries on
3021 targets where the operating system manages the list of loaded
3022 libraries (e.g. Windows and SymbianOS).
3026 Support for these obsolete configurations has been removed.
3034 i[34567]86-*-lynxos*
3035 i[34567]86-*-netware*
3036 i[34567]86-*-sco3.2v5*
3037 i[34567]86-*-sco3.2v4*
3039 i[34567]86-*-sysv4.2*
3042 i[34567]86-*-unixware2*
3043 i[34567]86-*-unixware*
3052 * Other removed features
3059 Various m68k-only ROM monitors.
3066 Various Renesas ROM monitors and debugging interfaces for SH and
3071 Support for a Macraigor serial interface to on-chip debugging.
3072 GDB does not directly support the newer parallel or USB
3077 A debug information format. The predecessor to DWARF 2 and
3078 DWARF 3, which are still supported.
3080 Support for the HP aCC compiler on HP-UX/PA-RISC
3082 SOM-encapsulated symbolic debugging information, automatic
3083 invocation of pxdb, and the aCC custom C++ ABI. This does not
3084 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3085 with aCC can still be debugged on an assembly level.
3087 MIPS ".pdr" sections
3089 A MIPS-specific format used to describe stack frame layout
3090 in debugging information.
3094 GDB could work with an older version of Guile to debug
3095 the interpreter and Scheme programs running in it.
3097 set mips stack-arg-size
3098 set mips saved-gpreg-size
3100 Use "set mips abi" to control parameter passing for MIPS.
3102 *** Changes in GDB 6.6
3107 Cell Broadband Engine SPU spu-elf
3109 * GDB can now be configured as a cross-debugger targeting native Windows
3110 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3111 running on a Windows system over TCP/IP to debug Windows programs.
3113 * The GDB remote stub, gdbserver, has been updated to support Windows and
3114 Cygwin debugging. Both single-threaded and multi-threaded programs are
3117 * The "set trust-readonly-sections" command works again. This command was
3118 broken in GDB 6.3, 6.4, and 6.5.
3120 * The "load" command now supports writing to flash memory, if the remote
3121 stub provides the required support.
3123 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3124 longer requires symbolic debug information (e.g. DWARF-2).
3129 unset substitute-path
3130 show substitute-path
3131 Manage a list of substitution rules that GDB uses to rewrite the name
3132 of the directories where the sources are located. This can be useful
3133 for instance when the sources were moved to a different location
3134 between compilation and debugging.
3138 Print each CLI command as it is executed. Each command is prefixed with
3139 a number of `+' symbols representing the nesting depth.
3140 The source command now has a `-v' option to enable the same feature.
3144 The ARM Demon monitor support (RDP protocol, "target rdp").
3146 Kernel Object Display, an embedded debugging feature which only worked with
3147 an obsolete version of Cisco IOS.
3149 The 'set download-write-size' and 'show download-write-size' commands.
3151 * New remote packets
3154 Tell a stub about GDB client features, and request remote target features.
3155 The first feature implemented is PacketSize, which allows the target to
3156 specify the size of packets it can handle - to minimize the number of
3157 packets required and improve performance when connected to a remote
3161 Fetch an OS auxilliary vector from the remote stub. This packet is a
3162 more efficient replacement for qPart:auxv:read.
3164 qXfer:memory-map:read:
3165 Fetch a memory map from the remote stub, including information about
3166 RAM, ROM, and flash memory devices.
3171 Erase and program a flash memory device.
3173 * Removed remote packets
3176 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3177 used it, and only gdbserver implemented it.
3179 *** Changes in GDB 6.5
3183 Renesas M32C/M16C m32c-elf
3185 Morpho Technologies ms1 ms1-elf
3189 init-if-undefined Initialize a convenience variable, but
3190 only if it doesn't already have a value.
3192 The following commands are presently only implemented for native GNU/Linux:
3194 checkpoint Save a snapshot of the program state.
3196 restart <n> Return the program state to a
3197 previously saved state.
3199 info checkpoints List currently saved checkpoints.
3201 delete-checkpoint <n> Delete a previously saved checkpoint.
3203 set|show detach-on-fork Tell gdb whether to detach from a newly
3204 forked process, or to keep debugging it.
3206 info forks List forks of the user program that
3207 are available to be debugged.
3209 fork <n> Switch to debugging one of several
3210 forks of the user program that are
3211 available to be debugged.
3213 delete-fork <n> Delete a fork from the list of forks
3214 that are available to be debugged (and
3215 kill the forked process).
3217 detach-fork <n> Delete a fork from the list of forks
3218 that are available to be debugged (and
3219 allow the process to continue).
3223 Morpho Technologies ms2 ms1-elf
3225 * Improved Windows host support
3227 GDB now builds as a cross debugger hosted on i686-mingw32, including
3228 native console support, and remote communications using either
3229 network sockets or serial ports.
3231 * Improved Modula-2 language support
3233 GDB can now print most types in the Modula-2 syntax. This includes:
3234 basic types, set types, record types, enumerated types, range types,
3235 pointer types and ARRAY types. Procedure var parameters are correctly
3236 printed and hexadecimal addresses and character constants are also
3237 written in the Modula-2 syntax. Best results can be obtained by using
3238 GNU Modula-2 together with the -gdwarf-2 command line option.
3242 The ARM rdi-share module.
3244 The Netware NLM debug server.
3246 *** Changes in GDB 6.4
3248 * New native configurations
3250 OpenBSD/arm arm*-*-openbsd*
3251 OpenBSD/mips64 mips64-*-openbsd*
3255 Morpho Technologies ms1 ms1-elf
3257 * New command line options
3259 --batch-silent As for --batch, but totally silent.
3260 --return-child-result The debugger will exist with the same value
3261 the child (debugged) program exited with.
3262 --eval-command COMMAND, -ex COMMAND
3263 Execute a single GDB CLI command. This may be
3264 specified multiple times and in conjunction
3265 with the --command (-x) option.
3267 * Deprecated commands removed
3269 The following commands, that were deprecated in 2000, have been
3273 set|show arm disassembly-flavor set|show arm disassembler
3274 othernames set arm disassembler
3275 set|show remotedebug set|show debug remote
3276 set|show archdebug set|show debug arch
3277 set|show eventdebug set|show debug event
3280 * New BSD user-level threads support
3282 It is now possible to debug programs using the user-level threads
3283 library on OpenBSD and FreeBSD. Currently supported (target)
3286 FreeBSD/amd64 x86_64-*-freebsd*
3287 FreeBSD/i386 i386-*-freebsd*
3288 OpenBSD/i386 i386-*-openbsd*
3290 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3291 are not yet supported.
3293 * New support for Matsushita MN10300 w/sim added
3294 (Work in progress). mn10300-elf.
3296 * REMOVED configurations and files
3298 VxWorks and the XDR protocol *-*-vxworks
3299 Motorola MCORE mcore-*-*
3300 National Semiconductor NS32000 ns32k-*-*
3302 * New "set print array-indexes" command
3304 After turning this setting "on", GDB prints the index of each element
3305 when displaying arrays. The default is "off" to preserve the previous
3308 * VAX floating point support
3310 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3312 * User-defined command support
3314 In addition to using $arg0..$arg9 for argument passing, it is now possible
3315 to use $argc to determine now many arguments have been passed. See the
3316 section on user-defined commands in the user manual for more information.
3318 *** Changes in GDB 6.3:
3320 * New command line option
3322 GDB now accepts -l followed by a number to set the timeout for remote
3325 * GDB works with GCC -feliminate-dwarf2-dups
3327 GDB now supports a more compact representation of DWARF-2 debug
3328 information using DW_FORM_ref_addr references. These are produced
3329 by GCC with the option -feliminate-dwarf2-dups and also by some
3330 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3331 to use -feliminate-dwarf2-dups.
3333 * Internationalization
3335 When supported by the host system, GDB will be built with
3336 internationalization (libintl). The task of marking up the sources is
3337 continued, we're looking forward to our first translation.
3341 Initial support for debugging programs compiled with the GNAT
3342 implementation of the Ada programming language has been integrated
3343 into GDB. In this release, support is limited to expression evaluation.
3345 * New native configurations
3347 GNU/Linux/m32r m32r-*-linux-gnu
3351 GDB's remote protocol now includes support for the 'p' packet. This
3352 packet is used to fetch individual registers from a remote inferior.
3354 * END-OF-LIFE registers[] compatibility module
3356 GDB's internal register infrastructure has been completely rewritten.
3357 The new infrastructure making possible the implementation of key new
3358 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3361 GDB 6.3 will be the last release to include the the registers[]
3362 compatibility module that allowed out-of-date configurations to
3363 continue to work. This change directly impacts the following
3373 powerpc bdm protocol
3375 Unless there is activity to revive these configurations, they will be
3376 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3378 * OBSOLETE configurations and files
3380 Configurations that have been declared obsolete in this release have
3381 been commented out. Unless there is activity to revive these
3382 configurations, the next release of GDB will have their sources
3383 permanently REMOVED.
3392 *** Changes in GDB 6.2.1:
3394 * MIPS `break main; run' gave an heuristic-fence-post warning
3396 When attempting to run even a simple program, a warning about
3397 heuristic-fence-post being hit would be reported. This problem has
3400 * MIPS IRIX 'long double' crashed GDB
3402 When examining a long double variable, GDB would get a segmentation
3403 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3404 IRIX long double values).
3408 A bug in the VAX stack code was causing problems with the "next"
3409 command. This problem has been fixed.
3411 *** Changes in GDB 6.2:
3413 * Fix for ``many threads''
3415 On GNU/Linux systems that use the NPTL threads library, a program
3416 rapidly creating and deleting threads would confuse GDB leading to the
3419 ptrace: No such process.
3420 thread_db_get_info: cannot get thread info: generic error
3422 This problem has been fixed.
3424 * "-async" and "-noasync" options removed.
3426 Support for the broken "-noasync" option has been removed (it caused
3429 * New ``start'' command.
3431 This command runs the program until the begining of the main procedure.
3433 * New BSD Kernel Data Access Library (libkvm) interface
3435 Using ``target kvm'' it is now possible to debug kernel core dumps and
3436 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3437 platforms. Currently supported (native-only) configurations are:
3439 FreeBSD/amd64 x86_64-*-freebsd*
3440 FreeBSD/i386 i?86-*-freebsd*
3441 NetBSD/i386 i?86-*-netbsd*
3442 NetBSD/m68k m68*-*-netbsd*
3443 NetBSD/sparc sparc-*-netbsd*
3444 OpenBSD/amd64 x86_64-*-openbsd*
3445 OpenBSD/i386 i?86-*-openbsd*
3446 OpenBSD/m68k m68*-openbsd*
3447 OpenBSD/sparc sparc-*-openbsd*
3449 * Signal trampoline code overhauled
3451 Many generic problems with GDB's signal handling code have been fixed.
3452 These include: backtraces through non-contiguous stacks; recognition
3453 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3454 call; backtrace through a signal trampoline; step into and out of
3455 signal handlers; and single-stepping in the signal trampoline.
3457 Please note that kernel bugs are a limiting factor here. These
3458 features have been shown to work on an s390 GNU/Linux system that
3459 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3461 * Cygwin support for DWARF 2 added.
3463 * New native configurations
3465 GNU/Linux/hppa hppa*-*-linux*
3466 OpenBSD/hppa hppa*-*-openbsd*
3467 OpenBSD/m68k m68*-*-openbsd*
3468 OpenBSD/m88k m88*-*-openbsd*
3469 OpenBSD/powerpc powerpc-*-openbsd*
3470 NetBSD/vax vax-*-netbsd*
3471 OpenBSD/vax vax-*-openbsd*
3473 * END-OF-LIFE frame compatibility module
3475 GDB's internal frame infrastructure has been completely rewritten.
3476 The new infrastructure making it possible to support key new features
3477 including DWARF 2 Call Frame Information. To aid in the task of
3478 migrating old configurations to this new infrastructure, a
3479 compatibility module, that allowed old configurations to continue to
3480 work, was also included.
3482 GDB 6.2 will be the last release to include this frame compatibility
3483 module. This change directly impacts the following configurations:
3493 Unless there is activity to revive these configurations, they will be
3494 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3496 * REMOVED configurations and files
3498 Sun 3, running SunOS 3 m68*-*-sunos3*
3499 Sun 3, running SunOS 4 m68*-*-sunos4*
3500 Sun 2, running SunOS 3 m68000-*-sunos3*
3501 Sun 2, running SunOS 4 m68000-*-sunos4*
3502 Motorola 680x0 running LynxOS m68*-*-lynxos*
3503 AT&T 3b1/Unix pc m68*-att-*
3504 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3505 decstation mips-dec-* mips-little-*
3506 riscos mips-*-riscos* mips-*-sysv*
3507 sonymips mips-sony-*
3508 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3510 *** Changes in GDB 6.1.1:
3512 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3514 The TUI (Text-mode User Interface) is now built as part of a default
3515 GDB configuration. It is enabled by either selecting the TUI with the
3516 command line option "-i=tui" or by running the separate "gdbtui"
3517 program. For more information on the TUI, see the manual "Debugging
3520 * Pending breakpoint support (also included in GDB 6.1)
3522 Support has been added to allow you to specify breakpoints in shared
3523 libraries that have not yet been loaded. If a breakpoint location
3524 cannot be found, and the "breakpoint pending" option is set to auto,
3525 GDB queries you if you wish to make the breakpoint pending on a future
3526 shared-library load. If and when GDB resolves the breakpoint symbol,
3527 the pending breakpoint is removed as one or more regular breakpoints
3530 Pending breakpoints are very useful for GCJ Java debugging.
3532 * Fixed ISO-C build problems
3534 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3535 non ISO-C code that stopped them being built using a more strict ISO-C
3536 compiler (e.g., IBM's C compiler).
3538 * Fixed build problem on IRIX 5
3540 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3541 wasn't able to compile compile on an IRIX 5 system.
3543 * Added execute permission to gdb/gdbserver/configure
3545 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3546 permission. This bug would cause configure to fail on a number of
3547 systems (Solaris, IRIX). Ref: server/519.
3549 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3551 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3552 has been updated to use constant array sizes.
3554 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3556 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3557 its generated DWARF Call Frame Info. This encoding was causing GDB to
3558 panic, that panic has been fixed. Ref: gdb/1628.
3560 * Fixed a problem when examining parameters in shared library code.
3562 When examining parameters in optimized shared library code generated
3563 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3564 not available''. GDB now correctly displays the variable's value.
3566 *** Changes in GDB 6.1:
3568 * Removed --with-mmalloc
3570 Support for the mmalloc memory manager has been removed, as it
3571 conflicted with the internal gdb byte cache.
3573 * Changes in AMD64 configurations
3575 The AMD64 target now includes the %cs and %ss registers. As a result
3576 the AMD64 remote protocol has changed; this affects the floating-point
3577 and SSE registers. If you rely on those registers for your debugging,
3578 you should upgrade gdbserver on the remote side.
3580 * Revised SPARC target
3582 The SPARC target has been completely revised, incorporating the
3583 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3584 support for LynxOS and SunOS 4 has been dropped. Calling functions
3585 from within GDB on operating systems with a non-executable stack
3586 (Solaris, OpenBSD) now works.
3590 GDB has a new C++ demangler which does a better job on the mangled
3591 names generated by current versions of g++. It also runs faster, so
3592 with this and other changes gdb should now start faster on large C++
3595 * DWARF 2 Location Expressions
3597 GDB support for location expressions has been extended to support function
3598 arguments and frame bases. Older versions of GDB could crash when they
3601 * C++ nested types and namespaces
3603 GDB's support for nested types and namespaces in C++ has been
3604 improved, especially if you use the DWARF 2 debugging format. (This
3605 is the default for recent versions of GCC on most platforms.)
3606 Specifically, if you have a class "Inner" defined within a class or
3607 namespace "Outer", then GDB realizes that the class's name is
3608 "Outer::Inner", not simply "Inner". This should greatly reduce the
3609 frequency of complaints about not finding RTTI symbols. In addition,
3610 if you are stopped at inside of a function defined within a namespace,
3611 GDB modifies its name lookup accordingly.
3613 * New native configurations
3615 NetBSD/amd64 x86_64-*-netbsd*
3616 OpenBSD/amd64 x86_64-*-openbsd*
3617 OpenBSD/alpha alpha*-*-openbsd*
3618 OpenBSD/sparc sparc-*-openbsd*
3619 OpenBSD/sparc64 sparc64-*-openbsd*
3621 * New debugging protocols
3623 M32R with SDI protocol m32r-*-elf*
3625 * "set prompt-escape-char" command deleted.
3627 The command "set prompt-escape-char" has been deleted. This command,
3628 and its very obscure effet on GDB's prompt, was never documented,
3629 tested, nor mentioned in the NEWS file.
3631 * OBSOLETE configurations and files
3633 Configurations that have been declared obsolete in this release have
3634 been commented out. Unless there is activity to revive these
3635 configurations, the next release of GDB will have their sources
3636 permanently REMOVED.
3638 Sun 3, running SunOS 3 m68*-*-sunos3*
3639 Sun 3, running SunOS 4 m68*-*-sunos4*
3640 Sun 2, running SunOS 3 m68000-*-sunos3*
3641 Sun 2, running SunOS 4 m68000-*-sunos4*
3642 Motorola 680x0 running LynxOS m68*-*-lynxos*
3643 AT&T 3b1/Unix pc m68*-att-*
3644 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3645 decstation mips-dec-* mips-little-*
3646 riscos mips-*-riscos* mips-*-sysv*
3647 sonymips mips-sony-*
3648 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3650 * REMOVED configurations and files
3652 SGI Irix-4.x mips-sgi-irix4 or iris4
3653 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3654 Z8000 simulator z8k-zilog-none or z8ksim
3655 Matsushita MN10200 w/simulator mn10200-*-*
3656 H8/500 simulator h8500-hitachi-hms or h8500hms
3657 HP/PA running BSD hppa*-*-bsd*
3658 HP/PA running OSF/1 hppa*-*-osf*
3659 HP/PA Pro target hppa*-*-pro*
3660 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3661 386BSD i[3456]86-*-bsd*
3662 Sequent family i[3456]86-sequent-sysv4*
3663 i[3456]86-sequent-sysv*
3664 i[3456]86-sequent-bsd*
3665 SPARC running LynxOS sparc-*-lynxos*
3666 SPARC running SunOS 4 sparc-*-sunos4*
3667 Tsqware Sparclet sparclet-*-*
3668 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3670 *** Changes in GDB 6.0:
3674 Support for debugging the Objective-C programming language has been
3675 integrated into GDB.
3677 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3679 DWARF 2's Call Frame Information makes available compiler generated
3680 information that more exactly describes the program's run-time stack.
3681 By using this information, GDB is able to provide more robust stack
3684 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3685 have been updated to use a new backtrace mechanism which includes
3686 DWARF 2 CFI support.
3690 GDB's remote protocol has been extended to include support for hosted
3691 file I/O (where the remote target uses GDB's file system). See GDB's
3692 remote protocol documentation for details.
3694 * All targets using the new architecture framework.
3696 All of GDB's targets have been updated to use the new internal
3697 architecture framework. The way is now open for future GDB releases
3698 to include cross-architecture native debugging support (i386 on amd64,
3701 * GNU/Linux's Thread Local Storage (TLS)
3703 GDB now includes support for for the GNU/Linux implementation of
3704 per-thread variables.
3706 * GNU/Linux's Native POSIX Thread Library (NPTL)
3708 GDB's thread code has been updated to work with either the new
3709 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3711 * Separate debug info.
3713 GDB, in conjunction with BINUTILS, now supports a mechanism for
3714 automatically loading debug information from a separate file. Instead
3715 of shipping full debug and non-debug versions of system libraries,
3716 system integrators can now instead ship just the stripped libraries
3717 and optional debug files.
3719 * DWARF 2 Location Expressions
3721 DWARF 2 Location Expressions allow the compiler to more completely
3722 describe the location of variables (even in optimized code) to the
3725 GDB now includes preliminary support for location expressions (support
3726 for DW_OP_piece is still missing).
3730 A number of long standing bugs that caused GDB to die while starting a
3731 Java application have been fixed. GDB's Java support is now
3732 considered "useable".
3734 * GNU/Linux support for fork, vfork, and exec.
3736 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3737 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3740 * GDB supports logging output to a file
3742 There are two new commands, "set logging" and "show logging", which can be
3743 used to capture GDB's output to a file.
3745 * The meaning of "detach" has changed for gdbserver
3747 The "detach" command will now resume the application, as documented. To
3748 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3751 * d10v, m68hc11 `regs' command deprecated
3753 The `info registers' command has been updated so that it displays the
3754 registers using a format identical to the old `regs' command.
3758 A new command, "maint set profile on/off", has been added. This command can
3759 be used to enable or disable profiling while running GDB, to profile a
3760 session or a set of commands. In addition there is a new configure switch,
3761 "--enable-profiling", which will cause GDB to be compiled with profiling
3762 data, for more informative profiling results.
3764 * Default MI syntax changed to "mi2".
3766 The default MI (machine interface) syntax, enabled by the command line
3767 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3768 "mi1", can be enabled by specifying the option "-i=mi1".
3770 Support for the original "mi0" syntax (included in GDB 5.0) has been
3773 Fix for gdb/192: removed extraneous space when displaying frame level.
3774 Fix for gdb/672: update changelist is now output in mi list format.
3775 Fix for gdb/702: a -var-assign that updates the value now shows up
3776 in a subsequent -var-update.
3778 * New native configurations.
3780 FreeBSD/amd64 x86_64-*-freebsd*
3782 * Multi-arched targets.
3784 HP/PA HPUX11 hppa*-*-hpux*
3785 Renesas M32R/D w/simulator m32r-*-elf*
3787 * OBSOLETE configurations and files
3789 Configurations that have been declared obsolete in this release have
3790 been commented out. Unless there is activity to revive these
3791 configurations, the next release of GDB will have their sources
3792 permanently REMOVED.
3794 Z8000 simulator z8k-zilog-none or z8ksim
3795 Matsushita MN10200 w/simulator mn10200-*-*
3796 H8/500 simulator h8500-hitachi-hms or h8500hms
3797 HP/PA running BSD hppa*-*-bsd*
3798 HP/PA running OSF/1 hppa*-*-osf*
3799 HP/PA Pro target hppa*-*-pro*
3800 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3801 Sequent family i[3456]86-sequent-sysv4*
3802 i[3456]86-sequent-sysv*
3803 i[3456]86-sequent-bsd*
3804 Tsqware Sparclet sparclet-*-*
3805 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3807 * REMOVED configurations and files
3810 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3811 IBM AIX PS/2 i[3456]86-*-aix
3812 i386 running Mach 3.0 i[3456]86-*-mach3*
3813 i386 running Mach i[3456]86-*-mach*
3814 i386 running OSF/1 i[3456]86-*osf1mk*
3815 HP/Apollo 68k Family m68*-apollo*-sysv*,
3817 m68*-hp-bsd*, m68*-hp-hpux*
3818 Argonaut Risc Chip (ARC) arc-*-*
3819 Mitsubishi D30V d30v-*-*
3820 Fujitsu FR30 fr30-*-elf*
3821 OS/9000 i[34]86-*-os9k
3822 I960 with MON960 i960-*-coff
3824 * MIPS $fp behavior changed
3826 The convenience variable $fp, for the MIPS, now consistently returns
3827 the address of the current frame's base. Previously, depending on the
3828 context, $fp could refer to either $sp or the current frame's base
3829 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3830 The GNU Source-Level Debugger''.
3832 *** Changes in GDB 5.3:
3834 * GNU/Linux shared library multi-threaded performance improved.
3836 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3837 `/proc', in preference to `ptrace' for memory reads. This may result
3838 in an improvement in the start-up time of multi-threaded, shared
3839 library applications when run under GDB. One GDB user writes: ``loads
3840 shared libs like mad''.
3842 * ``gdbserver'' now supports multi-threaded applications on some targets
3844 Support for debugging multi-threaded applications which use
3845 the GNU/Linux LinuxThreads package has been added for
3846 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3847 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3849 * GDB now supports C/C++ preprocessor macros.
3851 GDB now expands preprocessor macro invocations in C/C++ expressions,
3852 and provides various commands for showing macro definitions and how
3855 The new command `macro expand EXPRESSION' expands any macro
3856 invocations in expression, and shows the result.
3858 The new command `show macro MACRO-NAME' shows the definition of the
3859 macro named MACRO-NAME, and where it was defined.
3861 Most compilers don't include information about macros in the debugging
3862 information by default. In GCC 3.1, for example, you need to compile
3863 your program with the options `-gdwarf-2 -g3'. If the macro
3864 information is present in the executable, GDB will read it.
3866 * Multi-arched targets.
3868 DEC Alpha (partial) alpha*-*-*
3869 DEC VAX (partial) vax-*-*
3871 National Semiconductor NS32000 (partial) ns32k-*-*
3872 Motorola 68000 (partial) m68k-*-*
3873 Motorola MCORE mcore-*-*
3877 Fujitsu FRV architecture added by Red Hat frv*-*-*
3880 * New native configurations
3882 Alpha NetBSD alpha*-*-netbsd*
3883 SH NetBSD sh*-*-netbsdelf*
3884 MIPS NetBSD mips*-*-netbsd*
3885 UltraSPARC NetBSD sparc64-*-netbsd*
3887 * OBSOLETE configurations and files
3889 Configurations that have been declared obsolete in this release have
3890 been commented out. Unless there is activity to revive these
3891 configurations, the next release of GDB will have their sources
3892 permanently REMOVED.
3894 Mitsubishi D30V d30v-*-*
3895 OS/9000 i[34]86-*-os9k
3896 IBM AIX PS/2 i[3456]86-*-aix
3897 Fujitsu FR30 fr30-*-elf*
3898 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3899 Argonaut Risc Chip (ARC) arc-*-*
3900 i386 running Mach 3.0 i[3456]86-*-mach3*
3901 i386 running Mach i[3456]86-*-mach*
3902 i386 running OSF/1 i[3456]86-*osf1mk*
3903 HP/Apollo 68k Family m68*-apollo*-sysv*,
3905 m68*-hp-bsd*, m68*-hp-hpux*
3906 I960 with MON960 i960-*-coff
3908 * OBSOLETE languages
3910 CHILL, a Pascal like language used by telecommunications companies.
3912 * REMOVED configurations and files
3914 AMD 29k family via UDI a29k-amd-udi, udi29k
3915 A29K VxWorks a29k-*-vxworks
3916 AMD 29000 embedded, using EBMON a29k-none-none
3917 AMD 29000 embedded with COFF a29k-none-coff
3918 AMD 29000 embedded with a.out a29k-none-aout
3920 testsuite/gdb.hp/gdb.threads-hp/ directory
3922 * New command "set max-user-call-depth <nnn>"
3924 This command allows the user to limit the call depth of user-defined
3925 commands. The default is 1024.
3927 * Changes in FreeBSD/i386 native debugging.
3929 Support for the "generate-core-file" has been added.
3931 * New commands "dump", "append", and "restore".
3933 These commands allow data to be copied from target memory
3934 to a bfd-format or binary file (dump and append), and back
3935 from a file into memory (restore).
3937 * Improved "next/step" support on multi-processor Alpha Tru64.
3939 The previous single-step mechanism could cause unpredictable problems,
3940 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3941 of a software single-step mechanism prevents this.
3943 *** Changes in GDB 5.2.1:
3951 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3952 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3953 Fix, by Joel Brobecker imported from mainline.
3955 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3956 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3957 Fix, by Fred Fish, imported from mainline.
3959 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3960 Surprisingly enough, it works now.
3961 By Michal Ludvig, imported from mainline.
3963 i386 hardware watchpoint support:
3964 avoid misses on second run for some targets.
3965 By Pierre Muller, imported from mainline.
3967 *** Changes in GDB 5.2:
3969 * New command "set trust-readonly-sections on[off]".
3971 This command is a hint that tells gdb that read-only sections
3972 really are read-only (ie. that their contents will not change).
3973 In this mode, gdb will go to the object file rather than the
3974 target to read memory from read-only sections (such as ".text").
3975 This can be a significant performance improvement on some
3976 (notably embedded) targets.
3978 * New command "generate-core-file" (or "gcore").
3980 This new gdb command allows the user to drop a core file of the child
3981 process state at any time. So far it's been implemented only for
3982 GNU/Linux and Solaris, but should be relatively easily ported to other
3983 hosts. Argument is core file name (defaults to core.<pid>).
3985 * New command line option
3987 GDB now accepts --pid or -p followed by a process id.
3989 * Change in command line behavior -- corefiles vs. process ids.
3991 There is a subtle behavior in the way in which GDB handles
3992 command line arguments. The first non-flag argument is always
3993 a program to debug, but the second non-flag argument may either
3994 be a corefile or a process id. Previously, GDB would attempt to
3995 open the second argument as a corefile, and if that failed, would
3996 issue a superfluous error message and then attempt to attach it as
3997 a process. Now, if the second argument begins with a non-digit,
3998 it will be treated as a corefile. If it begins with a digit,
3999 GDB will attempt to attach it as a process, and if no such process
4000 is found, will then attempt to open it as a corefile.
4002 * Changes in ARM configurations.
4004 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4005 configuration is fully multi-arch.
4007 * New native configurations
4009 ARM NetBSD arm*-*-netbsd*
4010 x86 OpenBSD i[3456]86-*-openbsd*
4011 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4012 Sparc64 running FreeBSD sparc64-*-freebsd*
4016 Sanyo XStormy16 xstormy16-elf
4018 * OBSOLETE configurations and files
4020 Configurations that have been declared obsolete in this release have
4021 been commented out. Unless there is activity to revive these
4022 configurations, the next release of GDB will have their sources
4023 permanently REMOVED.
4025 AMD 29k family via UDI a29k-amd-udi, udi29k
4026 A29K VxWorks a29k-*-vxworks
4027 AMD 29000 embedded, using EBMON a29k-none-none
4028 AMD 29000 embedded with COFF a29k-none-coff
4029 AMD 29000 embedded with a.out a29k-none-aout
4031 testsuite/gdb.hp/gdb.threads-hp/ directory
4033 * REMOVED configurations and files
4035 TI TMS320C80 tic80-*-*
4037 PowerPC Solaris powerpcle-*-solaris*
4038 PowerPC Windows NT powerpcle-*-cygwin32
4039 PowerPC Netware powerpc-*-netware*
4040 Harris/CXUX m88k m88*-harris-cxux*
4041 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4042 ns32k-utek-sysv* ns32k-utek-*
4043 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4044 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4045 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4046 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4047 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4049 * Changes to command line processing
4051 The new `--args' feature can be used to specify command-line arguments
4052 for the inferior from gdb's command line.
4054 * Changes to key bindings
4056 There is a new `operate-and-get-next' function bound to `C-o'.
4058 *** Changes in GDB 5.1.1
4060 Fix compile problem on DJGPP.
4062 Fix a problem with floating-point registers on the i386 being
4065 Fix to stop GDB crashing on .debug_str debug info.
4067 Numerous documentation fixes.
4069 Numerous testsuite fixes.
4071 *** Changes in GDB 5.1:
4073 * New native configurations
4075 Alpha FreeBSD alpha*-*-freebsd*
4076 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4077 MIPS GNU/Linux mips*-*-linux*
4078 MIPS SGI Irix 6.x mips*-sgi-irix6*
4079 ia64 AIX ia64-*-aix*
4080 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4084 Motorola 68HC11 and 68HC12 m68hc11-elf
4086 UltraSparc running GNU/Linux sparc64-*-linux*
4088 * OBSOLETE configurations and files
4090 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4091 Harris/CXUX m88k m88*-harris-cxux*
4092 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4093 ns32k-utek-sysv* ns32k-utek-*
4094 TI TMS320C80 tic80-*-*
4096 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4097 PowerPC Solaris powerpcle-*-solaris*
4098 PowerPC Windows NT powerpcle-*-cygwin32
4099 PowerPC Netware powerpc-*-netware*
4100 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4101 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4102 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4103 Apple Macintosh (MPW) host N/A
4105 stuff.c (Program to stuff files into a specially prepared space in kdb)
4106 kdb-start.c (Main loop for the standalone kernel debugger)
4108 Configurations that have been declared obsolete in this release have
4109 been commented out. Unless there is activity to revive these
4110 configurations, the next release of GDB will have their sources
4111 permanently REMOVED.
4113 * REMOVED configurations and files
4115 Altos 3068 m68*-altos-*
4116 Convex c1-*-*, c2-*-*
4118 ARM RISCix arm-*-* (as host)
4122 * GDB has been converted to ISO C.
4124 GDB's source code has been converted to ISO C. In particular, the
4125 sources are fully protoized, and rely on standard headers being
4130 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4132 * The MI enabled by default.
4134 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4135 revised and enabled by default. Packages which use GDB as a debugging
4136 engine behind a UI or another front end are encouraged to switch to
4137 using the GDB/MI interface, instead of the old annotations interface
4138 which is now deprecated.
4140 * Support for debugging Pascal programs.
4142 GDB now includes support for debugging Pascal programs. The following
4143 main features are supported:
4145 - Pascal-specific data types such as sets;
4147 - automatic recognition of Pascal sources based on file-name
4150 - Pascal-style display of data types, variables, and functions;
4152 - a Pascal expression parser.
4154 However, some important features are not yet supported.
4156 - Pascal string operations are not supported at all;
4158 - there are some problems with boolean types;
4160 - Pascal type hexadecimal constants are not supported
4161 because they conflict with the internal variables format;
4163 - support for Pascal objects and classes is not full yet;
4165 - unlike Pascal, GDB is case-sensitive for symbol names.
4167 * Changes in completion.
4169 Commands such as `shell', `run' and `set args', which pass arguments
4170 to inferior programs, now complete on file names, similar to what
4171 users expect at the shell prompt.
4173 Commands which accept locations, such as `disassemble', `print',
4174 `breakpoint', `until', etc. now complete on filenames as well as
4175 program symbols. Thus, if you type "break foob TAB", and the source
4176 files linked into the programs include `foobar.c', that file name will
4177 be one of the candidates for completion. However, file names are not
4178 considered for completion after you typed a colon that delimits a file
4179 name from a name of a function in that file, as in "break foo.c:bar".
4181 `set demangle-style' completes on available demangling styles.
4183 * New platform-independent commands:
4185 It is now possible to define a post-hook for a command as well as a
4186 hook that runs before the command. For more details, see the
4187 documentation of `hookpost' in the GDB manual.
4189 * Changes in GNU/Linux native debugging.
4191 Support for debugging multi-threaded programs has been completely
4192 revised for all platforms except m68k and sparc. You can now debug as
4193 many threads as your system allows you to have.
4195 Attach/detach is supported for multi-threaded programs.
4197 Support for SSE registers was added for x86. This doesn't work for
4198 multi-threaded programs though.
4200 * Changes in MIPS configurations.
4202 Multi-arch support is enabled for all MIPS configurations.
4204 GDB can now be built as native debugger on SGI Irix 6.x systems for
4205 debugging n32 executables. (Debugging 64-bit executables is not yet
4208 * Unified support for hardware watchpoints in all x86 configurations.
4210 Most (if not all) native x86 configurations support hardware-assisted
4211 breakpoints and watchpoints in a unified manner. This support
4212 implements debug register sharing between watchpoints, which allows to
4213 put a virtually infinite number of watchpoints on the same address,
4214 and also supports watching regions up to 16 bytes with several debug
4217 The new maintenance command `maintenance show-debug-regs' toggles
4218 debugging print-outs in functions that insert, remove, and test
4219 watchpoints and hardware breakpoints.
4221 * Changes in the DJGPP native configuration.
4223 New command ``info dos sysinfo'' displays assorted information about
4224 the CPU, OS, memory, and DPMI server.
4226 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4227 display information about segment descriptors stored in GDT, LDT, and
4230 New commands ``info dos pde'' and ``info dos pte'' display entries
4231 from Page Directory and Page Tables (for now works with CWSDPMI only).
4232 New command ``info dos address-pte'' displays the Page Table entry for
4233 a given linear address.
4235 GDB can now pass command lines longer than 126 characters to the
4236 program being debugged (requires an update to the libdbg.a library
4237 which is part of the DJGPP development kit).
4239 DWARF2 debug info is now supported.
4241 It is now possible to `step' and `next' through calls to `longjmp'.
4243 * Changes in documentation.
4245 All GDB documentation was converted to GFDL, the GNU Free
4246 Documentation License.
4248 Tracepoints-related commands are now fully documented in the GDB
4251 TUI, the Text-mode User Interface, is now documented in the manual.
4253 Tracepoints-related commands are now fully documented in the GDB
4256 The "GDB Internals" manual now has an index. It also includes
4257 documentation of `ui_out' functions, GDB coding standards, x86
4258 hardware watchpoints, and memory region attributes.
4260 * GDB's version number moved to ``version.in''
4262 The Makefile variable VERSION has been replaced by the file
4263 ``version.in''. People creating GDB distributions should update the
4264 contents of this file.
4268 GUD support is now a standard part of the EMACS distribution.
4270 *** Changes in GDB 5.0:
4272 * Improved support for debugging FP programs on x86 targets
4274 Unified and much-improved support for debugging floating-point
4275 programs on all x86 targets. In particular, ``info float'' now
4276 displays the FP registers in the same format on all x86 targets, with
4277 greater level of detail.
4279 * Improvements and bugfixes in hardware-assisted watchpoints
4281 It is now possible to watch array elements, struct members, and
4282 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4283 on x86 targets no longer erroneously trigger when the address is
4286 * Improvements in the native DJGPP version of GDB
4288 The distribution now includes all the scripts and auxiliary files
4289 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4290 machines ``out of the box''.
4292 The DJGPP version can now debug programs that use signals. It is
4293 possible to catch signals that happened in the debuggee, deliver
4294 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4295 would kill the program being debugged.) Programs that hook hardware
4296 interrupts (keyboard, timer, etc.) can also be debugged.
4298 It is now possible to debug DJGPP programs that redirect their
4299 standard handles or switch them to raw (as opposed to cooked) mode, or
4300 even close them. The command ``run < foo > bar'' works as expected,
4301 and ``info terminal'' reports useful information about the debuggee's
4302 terminal, including raw/cooked mode, redirection, etc.
4304 The DJGPP version now uses termios functions for console I/O, which
4305 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4308 DOS-style file names with drive letters are now fully supported by
4311 It is now possible to debug DJGPP programs that switch their working
4312 directory. It is also possible to rerun the debuggee any number of
4313 times without restarting GDB; thus, you can use the same setup,
4314 breakpoints, etc. for many debugging sessions.
4316 * New native configurations
4318 ARM GNU/Linux arm*-*-linux*
4319 PowerPC GNU/Linux powerpc-*-linux*
4323 Motorola MCore mcore-*-*
4324 x86 VxWorks i[3456]86-*-vxworks*
4325 PowerPC VxWorks powerpc-*-vxworks*
4326 TI TMS320C80 tic80-*-*
4328 * OBSOLETE configurations
4330 Altos 3068 m68*-altos-*
4331 Convex c1-*-*, c2-*-*
4333 ARM RISCix arm-*-* (as host)
4336 Configurations that have been declared obsolete will be commented out,
4337 but the code will be left in place. If there is no activity to revive
4338 these configurations before the next release of GDB, the sources will
4339 be permanently REMOVED.
4341 * Gould support removed
4343 Support for the Gould PowerNode and NP1 has been removed.
4345 * New features for SVR4
4347 On SVR4 native platforms (such as Solaris), if you attach to a process
4348 without first loading a symbol file, GDB will now attempt to locate and
4349 load symbols from the running process's executable file.
4351 * Many C++ enhancements
4353 C++ support has been greatly improved. Overload resolution now works properly
4354 in almost all cases. RTTI support is on the way.
4356 * Remote targets can connect to a sub-program
4358 A popen(3) style serial-device has been added. This device starts a
4359 sub-process (such as a stand-alone simulator) and then communicates
4360 with that. The sub-program to run is specified using the syntax
4361 ``|<program> <args>'' vis:
4363 (gdb) set remotedebug 1
4364 (gdb) target extended-remote |mn10300-elf-sim program-args
4366 * MIPS 64 remote protocol
4368 A long standing bug in the mips64 remote protocol where by GDB
4369 expected certain 32 bit registers (ex SR) to be transfered as 32
4370 instead of 64 bits has been fixed.
4372 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4373 added to provide backward compatibility with older versions of GDB.
4375 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4377 The command ``set remotebinarydownload'' command has been replaced by
4378 ``set remote X-packet''. Other commands in ``set remote'' family
4379 include ``set remote P-packet''.
4381 * Breakpoint commands accept ranges.
4383 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4384 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4385 ``tracepoint passcount'' also accepts a range of tracepoints.
4387 * ``apropos'' command added.
4389 The ``apropos'' command searches through command names and
4390 documentation strings, printing out matches, making it much easier to
4391 try to find a command that does what you are looking for.
4395 A new machine oriented interface (MI) has been added to GDB. This
4396 interface is designed for debug environments running GDB as a separate
4397 process. This is part of the long term libGDB project. See the
4398 "GDB/MI" chapter of the GDB manual for further information. It can be
4399 enabled by configuring with:
4401 .../configure --enable-gdbmi
4403 *** Changes in GDB-4.18:
4405 * New native configurations
4407 HP-UX 10.20 hppa*-*-hpux10.20
4408 HP-UX 11.x hppa*-*-hpux11.0*
4409 M68K GNU/Linux m68*-*-linux*
4413 Fujitsu FR30 fr30-*-elf*
4414 Intel StrongARM strongarm-*-*
4415 Mitsubishi D30V d30v-*-*
4417 * OBSOLETE configurations
4419 Gould PowerNode, NP1 np1-*-*, pn-*-*
4421 Configurations that have been declared obsolete will be commented out,
4422 but the code will be left in place. If there is no activity to revive
4423 these configurations before the next release of GDB, the sources will
4424 be permanently REMOVED.
4428 As a compatibility experiment, GDB's source files buildsym.h and
4429 buildsym.c have been converted to pure standard C, no longer
4430 containing any K&R compatibility code. We believe that all systems in
4431 use today either come with a standard C compiler, or have a GCC port
4432 available. If this is not true, please report the affected
4433 configuration to bug-gdb@gnu.org immediately. See the README file for
4434 information about getting a standard C compiler if you don't have one
4439 GDB now uses readline 2.2.
4441 * set extension-language
4443 You can now control the mapping between filename extensions and source
4444 languages by using the `set extension-language' command. For instance,
4445 you can ask GDB to treat .c files as C++ by saying
4446 set extension-language .c c++
4447 The command `info extensions' lists all of the recognized extensions
4448 and their associated languages.
4450 * Setting processor type for PowerPC and RS/6000
4452 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4453 you can use the `set processor' command to specify what variant of the
4454 PowerPC family you are debugging. The command
4458 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4459 following PowerPC and RS6000 variants:
4461 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4462 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4464 403GC IBM PowerPC 403GC
4465 505 Motorola PowerPC 505
4466 860 Motorola PowerPC 860 or 850
4467 601 Motorola PowerPC 601
4468 602 Motorola PowerPC 602
4469 603 Motorola/IBM PowerPC 603 or 603e
4470 604 Motorola PowerPC 604 or 604e
4471 750 Motorola/IBM PowerPC 750 or 750
4473 At the moment, this command just tells GDB what to name the
4474 special-purpose processor registers. Since almost all the affected
4475 registers are inaccessible to user-level programs, this command is
4476 only useful for remote debugging in its present form.
4480 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4481 more extensive support for HP-UX. Added features include shared
4482 library support, kernel threads and hardware watchpoints for 11.00,
4483 support for HP's ANSI C and C++ compilers, and a compatibility mode
4484 for xdb and dbx commands.
4488 HP's donation includes the new concept of catchpoints, which is a
4489 generalization of the old catch command. On HP-UX, it is now possible
4490 to catch exec, fork, and vfork, as well as library loading.
4492 This means that the existing catch command has changed; its first
4493 argument now specifies the type of catch to be set up. See the
4494 output of "help catch" for a list of catchpoint types.
4496 * Debugging across forks
4498 On HP-UX, you can choose which process to debug when a fork() happens
4503 HP has donated a curses-based terminal user interface (TUI). To get
4504 it, build with --enable-tui. Although this can be enabled for any
4505 configuration, at present it only works for native HP debugging.
4507 * GDB remote protocol additions
4509 A new protocol packet 'X' that writes binary data is now available.
4510 Default behavior is to try 'X', then drop back to 'M' if the stub
4511 fails to respond. The settable variable `remotebinarydownload'
4512 allows explicit control over the use of 'X'.
4514 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4515 full 64-bit address. The command
4517 set remoteaddresssize 32
4519 can be used to revert to the old behaviour. For existing remote stubs
4520 the change should not be noticed, as the additional address information
4523 In order to assist in debugging stubs, you may use the maintenance
4524 command `packet' to send any text string to the stub. For instance,
4526 maint packet heythere
4528 sends the packet "$heythere#<checksum>". Note that it is very easy to
4529 disrupt a debugging session by sending the wrong packet at the wrong
4532 The compare-sections command allows you to compare section data on the
4533 target to what is in the executable file without uploading or
4534 downloading, by comparing CRC checksums.
4536 * Tracing can collect general expressions
4538 You may now collect general expressions at tracepoints. This requires
4539 further additions to the target-side stub; see tracepoint.c and
4540 doc/agentexpr.texi for further details.
4542 * mask-address variable for Mips
4544 For Mips targets, you may control the zeroing of the upper 32 bits of
4545 a 64-bit address by entering `set mask-address on'. This is mainly
4546 of interest to users of embedded R4xxx and R5xxx processors.
4548 * Higher serial baud rates
4550 GDB's serial code now allows you to specify baud rates 57600, 115200,
4551 230400, and 460800 baud. (Note that your host system may not be able
4552 to achieve all of these rates.)
4556 The i960 configuration now includes an initial implementation of a
4557 builtin simulator, contributed by Jim Wilson.
4560 *** Changes in GDB-4.17:
4562 * New native configurations
4564 Alpha GNU/Linux alpha*-*-linux*
4565 Unixware 2.x i[3456]86-unixware2*
4566 Irix 6.x mips*-sgi-irix6*
4567 PowerPC GNU/Linux powerpc-*-linux*
4568 PowerPC Solaris powerpcle-*-solaris*
4569 Sparc GNU/Linux sparc-*-linux*
4570 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4574 Argonaut Risc Chip (ARC) arc-*-*
4575 Hitachi H8/300S h8300*-*-*
4576 Matsushita MN10200 w/simulator mn10200-*-*
4577 Matsushita MN10300 w/simulator mn10300-*-*
4578 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4579 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4580 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4581 Mitsubishi D10V w/simulator d10v-*-*
4582 Mitsubishi M32R/D w/simulator m32r-*-elf*
4583 Tsqware Sparclet sparclet-*-*
4584 NEC V850 w/simulator v850-*-*
4586 * New debugging protocols
4588 ARM with RDI protocol arm*-*-*
4589 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4590 DDB and LSI variants of PMON protocol mips*-*-*
4591 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4592 PowerPC with SDS protocol powerpc{,le}-*-eabi
4593 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4597 All configurations can now understand and use the DWARF 2 debugging
4598 format. The choice is automatic, if the symbol file contains DWARF 2
4603 GDB now includes basic Java language support. This support is
4604 only useful with Java compilers that produce native machine code.
4606 * solib-absolute-prefix and solib-search-path
4608 For SunOS and SVR4 shared libraries, you may now set the prefix for
4609 loading absolute shared library symbol files, and the search path for
4610 locating non-absolute shared library symbol files.
4612 * Live range splitting
4614 GDB can now effectively debug code for which GCC has performed live
4615 range splitting as part of its optimization. See gdb/doc/LRS for
4616 more details on the expected format of the stabs information.
4620 GDB's support for the GNU Hurd, including thread debugging, has been
4621 updated to work with current versions of the Hurd.
4625 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4626 instruction set. ARM GDB automatically detects when Thumb
4627 instructions are in use, and adjusts disassembly and backtracing
4632 GDB's MIPS target configurations now handle the MIP16 16-bit
4637 GDB now includes support for overlays; if an executable has been
4638 linked such that multiple sections are based at the same address, GDB
4639 will decide which section to use for symbolic info. You can choose to
4640 control the decision manually, using overlay commands, or implement
4641 additional target-side support and use "overlay load-target" to bring
4642 in the overlay mapping. Do "help overlay" for more detail.
4646 The command "info symbol <address>" displays information about
4647 the symbol at the specified address.
4651 The standard remote protocol now includes an extension that allows
4652 asynchronous collection and display of trace data. This requires
4653 extensive support in the target-side debugging stub. Tracing mode
4654 includes a new interaction mode in GDB and new commands: see the
4655 file tracepoint.c for more details.
4659 Configurations for embedded MIPS now include a simulator contributed
4660 by Cygnus Solutions. The simulator supports the instruction sets
4661 of most MIPS variants.
4665 Sparc configurations may now include the ERC32 simulator contributed
4666 by the European Space Agency. The simulator is not built into
4667 Sparc targets by default; configure with --enable-sim to include it.
4671 For target configurations that may include multiple variants of a
4672 basic architecture (such as MIPS and SH), you may now set the
4673 architecture explicitly. "set arch" sets, "info arch" lists
4674 the possible architectures.
4676 *** Changes in GDB-4.16:
4678 * New native configurations
4680 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4681 M68K NetBSD m68k-*-netbsd*
4682 PowerPC AIX 4.x powerpc-*-aix*
4683 PowerPC MacOS powerpc-*-macos*
4684 PowerPC Windows NT powerpcle-*-cygwin32
4685 RS/6000 AIX 4.x rs6000-*-aix4*
4689 ARM with RDP protocol arm-*-*
4690 I960 with MON960 i960-*-coff
4691 MIPS VxWorks mips*-*-vxworks*
4692 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4693 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4695 Matra Sparclet sparclet-*-*
4699 The powerpc-eabi configuration now includes the PSIM simulator,
4700 contributed by Andrew Cagney, with assistance from Mike Meissner.
4701 PSIM is a very elaborate model of the PowerPC, including not only
4702 basic instruction set execution, but also details of execution unit
4703 performance and I/O hardware. See sim/ppc/README for more details.
4707 GDB now works with Solaris 2.5.
4709 * Windows 95/NT native
4711 GDB will now work as a native debugger on Windows 95 and Windows NT.
4712 To build it from source, you must use the "gnu-win32" environment,
4713 which uses a DLL to emulate enough of Unix to run the GNU tools.
4714 Further information, binaries, and sources are available at
4715 ftp.cygnus.com, under pub/gnu-win32.
4717 * dont-repeat command
4719 If a user-defined command includes the command `dont-repeat', then the
4720 command will not be repeated if the user just types return. This is
4721 useful if the command is time-consuming to run, so that accidental
4722 extra keystrokes don't run the same command many times.
4724 * Send break instead of ^C
4726 The standard remote protocol now includes an option to send a break
4727 rather than a ^C to the target in order to interrupt it. By default,
4728 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4730 * Remote protocol timeout
4732 The standard remote protocol includes a new variable `remotetimeout'
4733 that allows you to set the number of seconds before GDB gives up trying
4734 to read from the target. The default value is 2.
4736 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4738 By default GDB will automatically keep track of objects as they are
4739 loaded and unloaded by the dynamic linker. By using the command `set
4740 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4741 when shared library events occur, thus allowing you to set breakpoints
4742 in shared libraries which are explicitly loaded by the inferior.
4744 Note this feature does not work on hpux8. On hpux9 you must link
4745 /usr/lib/end.o into your program. This feature should work
4746 automatically on hpux10.
4748 * Irix 5.x hardware watchpoint support
4750 Irix 5 configurations now support the use of hardware watchpoints.
4752 * Mips protocol "SYN garbage limit"
4754 When debugging a Mips target using the `target mips' protocol, you
4755 may set the number of characters that GDB will ignore by setting
4756 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4757 every character. The default value is 1050.
4759 * Recording and replaying remote debug sessions
4761 If you set `remotelogfile' to the name of a file, gdb will write to it
4762 a recording of a remote debug session. This recording may then be
4763 replayed back to gdb using "gdbreplay". See gdbserver/README for
4764 details. This is useful when you have a problem with GDB while doing
4765 remote debugging; you can make a recording of the session and send it
4766 to someone else, who can then recreate the problem.
4768 * Speedups for remote debugging
4770 GDB includes speedups for downloading and stepping MIPS systems using
4771 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4772 and more efficient S-record downloading.
4774 * Memory use reductions and statistics collection
4776 GDB now uses less memory and reports statistics about memory usage.
4777 Try the `maint print statistics' command, for example.
4779 *** Changes in GDB-4.15:
4781 * Psymtabs for XCOFF
4783 The symbol reader for AIX GDB now uses partial symbol tables. This
4784 can greatly improve startup time, especially for large executables.
4786 * Remote targets use caching
4788 Remote targets now use a data cache to speed up communication with the
4789 remote side. The data cache could lead to incorrect results because
4790 it doesn't know about volatile variables, thus making it impossible to
4791 debug targets which use memory mapped I/O devices. `set remotecache
4792 off' turns the the data cache off.
4794 * Remote targets may have threads
4796 The standard remote protocol now includes support for multiple threads
4797 in the target system, using new protocol commands 'H' and 'T'. See
4798 gdb/remote.c for details.
4802 If GDB is configured with `--enable-netrom', then it will include
4803 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4804 acts as though it is a bank of ROM on the target board, but you can
4805 write into it over the network. GDB's support consists only of
4806 support for fast loading into the emulated ROM; to debug, you must use
4807 another protocol, such as standard remote protocol. The usual
4808 sequence is something like
4810 target nrom <netrom-hostname>
4812 target remote <netrom-hostname>:1235
4816 GDB now includes support for the Apple Macintosh, as a host only. It
4817 may be run as either an MPW tool or as a standalone application, and
4818 it can debug through the serial port. All the usual GDB commands are
4819 available, but to the target command, you must supply "serial" as the
4820 device type instead of "/dev/ttyXX". See mpw-README in the main
4821 directory for more information on how to build. The MPW configuration
4822 scripts */mpw-config.in support only a few targets, and only the
4823 mips-idt-ecoff target has been tested.
4827 GDB configuration now uses autoconf. This is not user-visible,
4828 but does simplify configuration and building.
4832 GDB now supports hpux10.
4834 *** Changes in GDB-4.14:
4836 * New native configurations
4838 x86 FreeBSD i[345]86-*-freebsd
4839 x86 NetBSD i[345]86-*-netbsd
4840 NS32k NetBSD ns32k-*-netbsd
4841 Sparc NetBSD sparc-*-netbsd
4845 A29K VxWorks a29k-*-vxworks
4846 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4847 CPU32 EST-300 emulator m68*-*-est*
4848 PowerPC ELF powerpc-*-elf
4851 * Alpha OSF/1 support for procfs
4853 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4854 possible to attach to running processes. As the mounting of the /proc
4855 filesystem is optional on the Alpha, GDB automatically determines
4856 the availability of /proc during startup. This can lead to problems
4857 if /proc is unmounted after GDB has been started.
4859 * Arguments to user-defined commands
4861 User commands may accept up to 10 arguments separated by whitespace.
4862 Arguments are accessed within the user command via $arg0..$arg9. A
4865 print $arg0 + $arg1 + $arg2
4867 To execute the command use:
4870 Defines the command "adder" which prints the sum of its three arguments.
4871 Note the arguments are text substitutions, so they may reference variables,
4872 use complex expressions, or even perform inferior function calls.
4874 * New `if' and `while' commands
4876 This makes it possible to write more sophisticated user-defined
4877 commands. Both commands take a single argument, which is the
4878 expression to evaluate, and must be followed by the commands to
4879 execute, one per line, if the expression is nonzero, the list being
4880 terminated by the word `end'. The `if' command list may include an
4881 `else' word, which causes the following commands to be executed only
4882 if the expression is zero.
4884 * Fortran source language mode
4886 GDB now includes partial support for Fortran 77. It will recognize
4887 Fortran programs and can evaluate a subset of Fortran expressions, but
4888 variables and functions may not be handled correctly. GDB will work
4889 with G77, but does not yet know much about symbols emitted by other
4892 * Better HPUX support
4894 Most debugging facilities now work on dynamic executables for HPPAs
4895 running hpux9 or later. You can attach to running dynamically linked
4896 processes, but by default the dynamic libraries will be read-only, so
4897 for instance you won't be able to put breakpoints in them. To change
4898 that behavior do the following before running the program:
4904 This will cause the libraries to be mapped private and read-write.
4905 To revert to the normal behavior, do this:
4911 You cannot set breakpoints or examine data in the library until after
4912 the library is loaded if the function/data symbols do not have
4915 GDB can now also read debug symbols produced by the HP C compiler on
4916 HPPAs (sorry, no C++, Fortran or 68k support).
4918 * Target byte order now dynamically selectable
4920 You can choose which byte order to use with a target system, via the
4921 commands "set endian big" and "set endian little", and you can see the
4922 current setting by using "show endian". You can also give the command
4923 "set endian auto", in which case GDB will use the byte order
4924 associated with the executable. Currently, only embedded MIPS
4925 configurations support dynamic selection of target byte order.
4927 * New DOS host serial code
4929 This version uses DPMI interrupts to handle buffered I/O, so you
4930 no longer need to run asynctsr when debugging boards connected to
4933 *** Changes in GDB-4.13:
4935 * New "complete" command
4937 This lists all the possible completions for the rest of the line, if it
4938 were to be given as a command itself. This is intended for use by emacs.
4940 * Trailing space optional in prompt
4942 "set prompt" no longer adds a space for you after the prompt you set. This
4943 allows you to set a prompt which ends in a space or one that does not.
4945 * Breakpoint hit counts
4947 "info break" now displays a count of the number of times the breakpoint
4948 has been hit. This is especially useful in conjunction with "ignore"; you
4949 can ignore a large number of breakpoint hits, look at the breakpoint info
4950 to see how many times the breakpoint was hit, then run again, ignoring one
4951 less than that number, and this will get you quickly to the last hit of
4954 * Ability to stop printing at NULL character
4956 "set print null-stop" will cause GDB to stop printing the characters of
4957 an array when the first NULL is encountered. This is useful when large
4958 arrays actually contain only short strings.
4960 * Shared library breakpoints
4962 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4963 breakpoints in shared libraries before the executable is run.
4965 * Hardware watchpoints
4967 There is a new hardware breakpoint for the watch command for sparclite
4968 targets. See gdb/sparclite/hw_breakpoint.note.
4970 Hardware watchpoints are also now supported under GNU/Linux.
4974 Annotations have been added. These are for use with graphical interfaces,
4975 and are still experimental. Currently only gdba.el uses these.
4977 * Improved Irix 5 support
4979 GDB now works properly with Irix 5.2.
4981 * Improved HPPA support
4983 GDB now works properly with the latest GCC and GAS.
4985 * New native configurations
4987 Sequent PTX4 i[34]86-sequent-ptx4
4988 HPPA running OSF/1 hppa*-*-osf*
4989 Atari TT running SVR4 m68*-*-sysv4*
4990 RS/6000 LynxOS rs6000-*-lynxos*
4994 OS/9000 i[34]86-*-os9k
4995 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4998 * Hitachi SH7000 and E7000-PC ICE support
5000 There is now support for communicating with the Hitachi E7000-PC ICE.
5001 This is available automatically when GDB is configured for the SH.
5005 As usual, a variety of small fixes and improvements, both generic
5006 and configuration-specific. See the ChangeLog for more detail.
5008 *** Changes in GDB-4.12:
5010 * Irix 5 is now supported
5014 GDB-4.12 on the HPPA has a number of changes which make it unable
5015 to debug the output from the currently released versions of GCC and
5016 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5017 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5018 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5021 *** Changes in GDB-4.11:
5023 * User visible changes:
5027 The "set remotedebug" option is now consistent between the mips remote
5028 target, remote targets using the gdb-specific protocol, UDI (AMD's
5029 debug protocol for the 29k) and the 88k bug monitor. It is now an
5030 integer specifying a debug level (normally 0 or 1, but 2 means more
5031 debugging info for the mips target).
5033 * DEC Alpha native support
5035 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5036 debug info, but GDB works fairly well with the DEC compiler and should
5037 work with a future GCC release. See the README file for a few
5038 Alpha-specific notes.
5040 * Preliminary thread implementation
5042 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5044 * LynxOS native and target support for 386
5046 This release has been hosted on LynxOS 2.2, and also can be configured
5047 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5050 * Improvements in C++ mangling/demangling.
5052 This release has much better g++ debugging, specifically in name
5053 mangling/demangling, virtual function calls, print virtual table,
5054 call methods, ...etc.
5056 *** Changes in GDB-4.10:
5058 * User visible changes:
5060 Remote debugging using the GDB-specific (`target remote') protocol now
5061 supports the `load' command. This is only useful if you have some
5062 other way of getting the stub to the target system, and you can put it
5063 somewhere in memory where it won't get clobbered by the download.
5065 Filename completion now works.
5067 When run under emacs mode, the "info line" command now causes the
5068 arrow to point to the line specified. Also, "info line" prints
5069 addresses in symbolic form (as well as hex).
5071 All vxworks based targets now support a user settable option, called
5072 vxworks-timeout. This option represents the number of seconds gdb
5073 should wait for responses to rpc's. You might want to use this if
5074 your vxworks target is, perhaps, a slow software simulator or happens
5075 to be on the far side of a thin network line.
5079 This release contains support for using a DEC alpha as a GDB host for
5080 cross debugging. Native alpha debugging is not supported yet.
5083 *** Changes in GDB-4.9:
5087 This is the first GDB release which is accompanied by a matching testsuite.
5088 The testsuite requires installation of dejagnu, which should be available
5089 via ftp from most sites that carry GNU software.
5093 'Cfront' style demangling has had its name changed to 'ARM' style, to
5094 emphasize that it was written from the specifications in the C++ Annotated
5095 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5096 disclaimers, it still generated too much confusion with users attempting to
5097 use gdb with AT&T cfront.
5101 GDB now uses a standard remote interface to a simulator library.
5102 So far, the library contains simulators for the Zilog Z8001/2, the
5103 Hitachi H8/300, H8/500 and Super-H.
5105 * New targets supported
5107 H8/300 simulator h8300-hitachi-hms or h8300hms
5108 H8/500 simulator h8500-hitachi-hms or h8500hms
5109 SH simulator sh-hitachi-hms or sh
5110 Z8000 simulator z8k-zilog-none or z8ksim
5111 IDT MIPS board over serial line mips-idt-ecoff
5113 Cross-debugging to GO32 targets is supported. It requires a custom
5114 version of the i386-stub.c module which is integrated with the
5115 GO32 memory extender.
5117 * New remote protocols
5119 MIPS remote debugging protocol.
5121 * New source languages supported
5123 This version includes preliminary support for Chill, a Pascal like language
5124 used by telecommunications companies. Chill support is also being integrated
5125 into the GNU compiler, but we don't know when it will be publically available.
5128 *** Changes in GDB-4.8:
5130 * HP Precision Architecture supported
5132 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5133 version of this support was available as a set of patches from the
5134 University of Utah. GDB does not support debugging of programs
5135 compiled with the HP compiler, because HP will not document their file
5136 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5137 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5139 Many problems in the preliminary version have been fixed.
5141 * Faster and better demangling
5143 We have improved template demangling and fixed numerous bugs in the GNU style
5144 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5145 character types (wchar_t) are now supported. Demangling of each symbol is now
5146 only done once, and is cached when the symbol table for a file is read in.
5147 This results in a small increase in memory usage for C programs, a moderate
5148 increase in memory usage for C++ programs, and a fantastic speedup in
5151 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5152 from the specifications in the Annotated Reference Manual, which AT&T's
5153 compiler does not actually implement.
5155 * G++ multiple inheritance compiler problem
5157 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5158 inheritance lattices was reworked to properly discover ambiguities. We
5159 recently found an example which causes this new algorithm to fail in a
5160 very subtle way, producing bad debug information for those classes.
5161 The file 'gcc.patch' (in this directory) can be applied to gcc to
5162 circumvent the problem. A future GCC release will contain a complete
5165 The previous G++ debug info problem (mentioned below for the gdb-4.7
5166 release) is fixed in gcc version 2.3.2.
5168 * Improved configure script
5170 The `configure' script will now attempt to guess your system type if
5171 you don't supply a host system type. The old scheme of supplying a
5172 host system triplet is preferable over using this. All the magic is
5173 done in the new `config.guess' script. Examine it for details.
5175 We have also brought our configure script much more in line with the FSF's
5176 version. It now supports the --with-xxx options. In particular,
5177 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5178 The resulting GDB will not be able to read arbitrary object file formats --
5179 only the format ``expected'' to be used on the configured target system.
5180 We hope to make this the default in a future release.
5182 * Documentation improvements
5184 There's new internal documentation on how to modify GDB, and how to
5185 produce clean changes to the code. We implore people to read it
5186 before submitting changes.
5188 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5189 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5190 `info' files are also provided. To build `info' files from scratch,
5191 you will need the latest `makeinfo' release, which will be available in
5192 a future texinfo-X.Y release.
5194 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5195 We're not sure exactly which versions have this problem, but it has
5196 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5197 or better. If that isn't possible, there is a patch in
5198 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5199 around this problem.
5203 GDB now supports array constants that can be used in expressions typed in by
5204 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5205 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5208 The new directory `gdb/sparclite' contains a program that demonstrates
5209 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5211 * New native hosts supported
5213 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5214 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5216 * New targets supported
5218 AMD 29k family via UDI a29k-amd-udi or udi29k
5220 * New file formats supported
5222 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5223 HPUX core files, and SCO 3.2v2 core files.
5227 Attaching to processes now works again; thanks for the many bug reports.
5229 We have also stomped on a bunch of core dumps caused by
5230 printf_filtered("%s") problems.
5232 We eliminated a copyright problem on the rpc and ptrace header files
5233 for VxWorks, which was discovered at the last minute during the 4.7
5234 release. You should now be able to build a VxWorks GDB.
5236 You can now interrupt gdb while an attached process is running. This
5237 will cause the attached process to stop, and give control back to GDB.
5239 We fixed problems caused by using too many file descriptors
5240 for reading symbols from object files and libraries. This was
5241 especially a problem for programs that used many (~100) shared
5244 The `step' command now only enters a subroutine if there is line number
5245 information for the subroutine. Otherwise it acts like the `next'
5246 command. Previously, `step' would enter subroutines if there was
5247 any debugging information about the routine. This avoids problems
5248 when using `cc -g1' on MIPS machines.
5250 * Internal improvements
5252 GDB's internal interfaces have been improved to make it easier to support
5253 debugging of multiple languages in the future.
5255 GDB now uses a common structure for symbol information internally.
5256 Minimal symbols (derived from linkage symbols in object files), partial
5257 symbols (from a quick scan of debug information), and full symbols
5258 contain a common subset of information, making it easier to write
5259 shared code that handles any of them.
5261 * New command line options
5263 We now accept --silent as an alias for --quiet.
5267 The memory-mapped-malloc library is now licensed under the GNU Library
5268 General Public License.
5270 *** Changes in GDB-4.7:
5272 * Host/native/target split
5274 GDB has had some major internal surgery to untangle the support for
5275 hosts and remote targets. Now, when you configure GDB for a remote
5276 target, it will no longer load in all of the support for debugging
5277 local programs on the host. When fully completed and tested, this will
5278 ensure that arbitrary host/target combinations are possible.
5280 The primary conceptual shift is to separate the non-portable code in
5281 GDB into three categories. Host specific code is required any time GDB
5282 is compiled on that host, regardless of the target. Target specific
5283 code relates to the peculiarities of the target, but can be compiled on
5284 any host. Native specific code is everything else: it can only be
5285 built when the host and target are the same system. Child process
5286 handling and core file support are two common `native' examples.
5288 GDB's use of /proc for controlling Unix child processes is now cleaner.
5289 It has been split out into a single module under the `target_ops' vector,
5290 plus two native-dependent functions for each system that uses /proc.
5292 * New hosts supported
5294 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5295 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5296 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5298 * New targets supported
5300 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5301 68030 and CPU32 m68030-*-*, m68332-*-*
5303 * New native hosts supported
5305 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5306 (386bsd is not well tested yet)
5307 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5309 * New file formats supported
5311 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5312 supports reading of `a.out.adobe' object files, which are an a.out
5313 format extended with minimal information about multiple sections.
5317 `show copying' is the same as the old `info copying'.
5318 `show warranty' is the same as `info warrantee'.
5319 These were renamed for consistency. The old commands continue to work.
5321 `info handle' is a new alias for `info signals'.
5323 You can now define pre-command hooks, which attach arbitrary command
5324 scripts to any command. The commands in the hook will be executed
5325 prior to the user's command. You can also create a hook which will be
5326 executed whenever the program stops. See gdb.texinfo.
5330 We now deal with Cfront style name mangling, and can even extract type
5331 info from mangled symbols. GDB can automatically figure out which
5332 symbol mangling style your C++ compiler uses.
5334 Calling of methods and virtual functions has been improved as well.
5338 The crash that occured when debugging Sun Ansi-C compiled binaries is
5339 fixed. This was due to mishandling of the extra N_SO stabs output
5342 We also finally got Ultrix 4.2 running in house, and fixed core file
5343 support, with help from a dozen people on the net.
5345 John M. Farrell discovered that the reason that single-stepping was so
5346 slow on all of the Mips based platforms (primarily SGI and DEC) was
5347 that we were trying to demangle and lookup a symbol used for internal
5348 purposes on every instruction that was being stepped through. Changing
5349 the name of that symbol so that it couldn't be mistaken for a C++
5350 mangled symbol sped things up a great deal.
5352 Rich Pixley sped up symbol lookups in general by getting much smarter
5353 about when C++ symbol mangling is necessary. This should make symbol
5354 completion (TAB on the command line) much faster. It's not as fast as
5355 we'd like, but it's significantly faster than gdb-4.6.
5359 A new user controllable variable 'call_scratch_address' can
5360 specify the location of a scratch area to be used when GDB
5361 calls a function in the target. This is necessary because the
5362 usual method of putting the scratch area on the stack does not work
5363 in systems that have separate instruction and data spaces.
5365 We integrated changes to support the 29k UDI (Universal Debugger
5366 Interface), but discovered at the last minute that we didn't have all
5367 of the appropriate copyright paperwork. We are working with AMD to
5368 resolve this, and hope to have it available soon.
5372 We have sped up the remote serial line protocol, especially for targets
5373 with lots of registers. It now supports a new `expedited status' ('T')
5374 message which can be used in place of the existing 'S' status message.
5375 This allows the remote stub to send only the registers that GDB
5376 needs to make a quick decision about single-stepping or conditional
5377 breakpoints, eliminating the need to fetch the entire register set for
5378 each instruction being stepped through.
5380 The GDB remote serial protocol now implements a write-through cache for
5381 registers, only re-reading the registers if the target has run.
5383 There is also a new remote serial stub for SPARC processors. You can
5384 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5385 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5386 processor with a serial port.
5390 Configure.in files have become much easier to read and modify. A new
5391 `table driven' format makes it more obvious what configurations are
5392 supported, and what files each one uses.
5396 There is a new opcodes library which will eventually contain all of the
5397 disassembly routines and opcode tables. At present, it only contains
5398 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5399 disassembler (binutils/objdump) to share these routines.
5401 The libiberty library is now copylefted under the GNU Library General
5402 Public License. This allows more liberal use, and was done so libg++
5403 can use it. This makes no difference to GDB, since the Library License
5404 grants all the rights from the General Public License.
5408 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5409 reference to the stabs symbol info used by the debugger. It is (as far
5410 as we know) the only published document on this fascinating topic. We
5411 encourage you to read it, compare it to the stabs information on your
5412 system, and send improvements on the document in general (to
5413 bug-gdb@prep.ai.mit.edu).
5415 And, of course, many bugs have been fixed.
5418 *** Changes in GDB-4.6:
5420 * Better support for C++ function names
5422 GDB now accepts as input the "demangled form" of C++ overloaded function
5423 names and member function names, and can do command completion on such names
5424 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5425 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5426 Make use of command completion, it is your friend.
5428 GDB also now accepts a variety of C++ mangled symbol formats. They are
5429 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5430 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5431 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5432 for the list of formats.
5434 * G++ symbol mangling problem
5436 Recent versions of gcc have a bug in how they emit debugging information for
5437 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5438 directory) can be applied to gcc to fix the problem. Alternatively, if you
5439 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5440 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5441 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5444 * New 'maintenance' command
5446 All of the commands related to hacking GDB internals have been moved out of
5447 the main command set, and now live behind the 'maintenance' command. This
5448 can also be abbreviated as 'mt'. The following changes were made:
5450 dump-me -> maintenance dump-me
5451 info all-breakpoints -> maintenance info breakpoints
5452 printmsyms -> maintenance print msyms
5453 printobjfiles -> maintenance print objfiles
5454 printpsyms -> maintenance print psymbols
5455 printsyms -> maintenance print symbols
5457 The following commands are new:
5459 maintenance demangle Call internal GDB demangler routine to
5460 demangle a C++ link name and prints the result.
5461 maintenance print type Print a type chain for a given symbol
5463 * Change to .gdbinit file processing
5465 We now read the $HOME/.gdbinit file before processing the argv arguments
5466 (e.g. reading symbol files or core files). This allows global parameters to
5467 be set, which will apply during the symbol reading. The ./.gdbinit is still
5468 read after argv processing.
5470 * New hosts supported
5472 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5474 GNU/Linux support i386-unknown-linux or linux
5476 We are also including code to support the HP/PA running BSD and HPUX. This
5477 is almost guaranteed not to work, as we didn't have time to test or build it
5478 for this release. We are including it so that the more adventurous (or
5479 masochistic) of you can play with it. We also had major problems with the
5480 fact that the compiler that we got from HP doesn't support the -g option.
5483 * New targets supported
5485 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5487 * More smarts about finding #include files
5489 GDB now remembers the compilation directory for all include files, and for
5490 all files from which C is generated (like yacc and lex sources). This
5491 greatly improves GDB's ability to find yacc/lex sources, and include files,
5492 especially if you are debugging your program from a directory different from
5493 the one that contains your sources.
5495 We also fixed a bug which caused difficulty with listing and setting
5496 breakpoints in include files which contain C code. (In the past, you had to
5497 try twice in order to list an include file that you hadn't looked at before.)
5499 * Interesting infernals change
5501 GDB now deals with arbitrary numbers of sections, where the symbols for each
5502 section must be relocated relative to that section's landing place in the
5503 target's address space. This work was needed to support ELF with embedded
5504 stabs used by Solaris-2.0.
5506 * Bug fixes (of course!)
5508 There have been loads of fixes for the following things:
5509 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5510 i960, stabs, DOS(GO32), procfs, etc...
5512 See the ChangeLog for details.
5514 *** Changes in GDB-4.5:
5516 * New machines supported (host and target)
5518 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5520 SGI Irix-4.x mips-sgi-irix4 or iris4
5522 * New malloc package
5524 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5525 Mmalloc is capable of handling mutiple heaps of memory. It is also
5526 capable of saving a heap to a file, and then mapping it back in later.
5527 This can be used to greatly speedup the startup of GDB by using a
5528 pre-parsed symbol table which lives in a mmalloc managed heap. For
5529 more details, please read mmalloc/mmalloc.texi.
5533 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5534 'help info proc' for details.
5536 * MIPS ecoff symbol table format
5538 The code that reads MIPS symbol table format is now supported on all hosts.
5539 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5542 * File name changes for MS-DOS
5544 Many files in the config directories have been renamed to make it easier to
5545 support GDB on MS-DOSe systems (which have very restrictive file name
5546 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5547 environment) is close to working but has some remaining problems. Note
5548 that debugging of DOS programs is not supported, due to limitations
5549 in the ``operating system'', but it can be used to host cross-debugging.
5551 * Cross byte order fixes
5553 Many fixes have been made to support cross debugging of Sparc and MIPS
5554 targets from hosts whose byte order differs.
5556 * New -mapped and -readnow options
5558 If memory-mapped files are available on your system through the 'mmap'
5559 system call, you can use the -mapped option on the `file' or
5560 `symbol-file' commands to cause GDB to write the symbols from your
5561 program into a reusable file. If the program you are debugging is
5562 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5563 Future GDB debugging sessions will notice the presence of this file,
5564 and will quickly map in symbol information from it, rather than reading
5565 the symbol table from the executable program. Using the '-mapped'
5566 option in a GDB `file' or `symbol-file' command has the same effect as
5567 starting GDB with the '-mapped' command-line option.
5569 You can cause GDB to read the entire symbol table immediately by using
5570 the '-readnow' option with any of the commands that load symbol table
5571 information (or on the GDB command line). This makes the command
5572 slower, but makes future operations faster.
5574 The -mapped and -readnow options are typically combined in order to
5575 build a `fred.syms' file that contains complete symbol information.
5576 A simple GDB invocation to do nothing but build a `.syms' file for future
5579 gdb -batch -nx -mapped -readnow programname
5581 The `.syms' file is specific to the host machine on which GDB is run.
5582 It holds an exact image of GDB's internal symbol table. It cannot be
5583 shared across multiple host platforms.
5585 * longjmp() handling
5587 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5588 siglongjmp() without losing control. This feature has not yet been ported to
5589 all systems. It currently works on many 386 platforms, all MIPS-based
5590 platforms (SGI, DECstation, etc), and Sun3/4.
5594 Preliminary work has been put in to support the new Solaris OS from Sun. At
5595 this time, it can control and debug processes, but it is not capable of
5600 As always, many many bug fixes. The major areas were with g++, and mipsread.
5601 People using the MIPS-based platforms should experience fewer mysterious
5602 crashes and trashed symbol tables.
5604 *** Changes in GDB-4.4:
5606 * New machines supported (host and target)
5608 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5610 BSD Reno on Vax vax-dec-bsd
5611 Ultrix on Vax vax-dec-ultrix
5613 * New machines supported (target)
5615 AMD 29000 embedded, using EBMON a29k-none-none
5619 GDB continues to improve its handling of C++. `References' work better.
5620 The demangler has also been improved, and now deals with symbols mangled as
5621 per the Annotated C++ Reference Guide.
5623 GDB also now handles `stabs' symbol information embedded in MIPS
5624 `ecoff' symbol tables. Since the ecoff format was not easily
5625 extensible to handle new languages such as C++, this appeared to be a
5626 good way to put C++ debugging info into MIPS binaries. This option
5627 will be supported in the GNU C compiler, version 2, when it is
5630 * New features for SVR4
5632 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5633 shared libraries. Debugging dynamically linked programs should present
5634 only minor differences from debugging statically linked programs.
5636 The `info proc' command will print out information about any process
5637 on an SVR4 system (including the one you are debugging). At the moment,
5638 it prints the address mappings of the process.
5640 If you bring up GDB on another SVR4 system, please send mail to
5641 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5643 * Better dynamic linking support in SunOS
5645 Reading symbols from shared libraries which contain debugging symbols
5646 now works properly. However, there remain issues such as automatic
5647 skipping of `transfer vector' code during function calls, which
5648 make it harder to debug code in a shared library, than to debug the
5649 same code linked statically.
5653 GDB is now using the latest `getopt' routines from the FSF. This
5654 version accepts the -- prefix for options with long names. GDB will
5655 continue to accept the old forms (-option and +option) as well.
5656 Various single letter abbreviations for options have been explicity
5657 added to the option table so that they won't get overshadowed in the
5658 future by other options that begin with the same letter.
5662 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5663 Many assorted bugs have been handled. Many more remain to be handled.
5664 See the various ChangeLog files (primarily in gdb and bfd) for details.
5667 *** Changes in GDB-4.3:
5669 * New machines supported (host and target)
5671 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5672 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5673 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5675 * Almost SCO Unix support
5677 We had hoped to support:
5678 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5679 (except for core file support), but we discovered very late in the release
5680 that it has problems with process groups that render gdb unusable. Sorry
5681 about that. I encourage people to fix it and post the fixes.
5683 * Preliminary ELF and DWARF support
5685 GDB can read ELF object files on System V Release 4, and can handle
5686 debugging records for C, in DWARF format, in ELF files. This support
5687 is preliminary. If you bring up GDB on another SVR4 system, please
5688 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5693 GDB now uses the latest `readline' library. One user-visible change
5694 is that two tabs will list possible command completions, which previously
5695 required typing M-? (meta-question mark, or ESC ?).
5699 The `stepi' bug that many of you noticed has been squashed.
5700 Many bugs in C++ have been handled. Many more remain to be handled.
5701 See the various ChangeLog files (primarily in gdb and bfd) for details.
5703 * State of the MIPS world (in case you wondered):
5705 GDB can understand the symbol tables emitted by the compilers
5706 supplied by most vendors of MIPS-based machines, including DEC. These
5707 symbol tables are in a format that essentially nobody else uses.
5709 Some versions of gcc come with an assembler post-processor called
5710 mips-tfile. This program is required if you want to do source-level
5711 debugging of gcc-compiled programs. I believe FSF does not ship
5712 mips-tfile with gcc version 1, but it will eventually come with gcc
5715 Debugging of g++ output remains a problem. g++ version 1.xx does not
5716 really support it at all. (If you're lucky, you should be able to get
5717 line numbers and stack traces to work, but no parameters or local
5718 variables.) With some work it should be possible to improve the
5721 When gcc version 2 is released, you will have somewhat better luck.
5722 However, even then you will get confusing results for inheritance and
5725 We will eventually provide full debugging of g++ output on
5726 DECstations. This will probably involve some kind of stabs-in-ecoff
5727 encapulation, but the details have not been worked out yet.
5730 *** Changes in GDB-4.2:
5732 * Improved configuration
5734 Only one copy of `configure' exists now, and it is not self-modifying.
5735 Porting BFD is simpler.
5739 The `step' and `next' commands now only stop at the first instruction
5740 of a source line. This prevents the multiple stops that used to occur
5741 in switch statements, for-loops, etc. `Step' continues to stop if a
5742 function that has debugging information is called within the line.
5746 Lots of small bugs fixed. More remain.
5748 * New host supported (not target)
5750 Intel 386 PC clone running Mach i386-none-mach
5753 *** Changes in GDB-4.1:
5755 * Multiple source language support
5757 GDB now has internal scaffolding to handle several source languages.
5758 It determines the type of each source file from its filename extension,
5759 and will switch expression parsing and number formatting to match the
5760 language of the function in the currently selected stack frame.
5761 You can also specifically set the language to be used, with
5762 `set language c' or `set language modula-2'.
5766 GDB now has preliminary support for the GNU Modula-2 compiler,
5767 currently under development at the State University of New York at
5768 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5769 continue through the fall of 1991 and into 1992.
5771 Other Modula-2 compilers are currently not supported, and attempting to
5772 debug programs compiled with them will likely result in an error as the
5773 symbol table is read. Feel free to work on it, though!
5775 There are hooks in GDB for strict type checking and range checking,
5776 in the `Modula-2 philosophy', but they do not currently work.
5780 GDB can now write to executable and core files (e.g. patch
5781 a variable's value). You must turn this switch on, specify
5782 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5783 by assigning a new value to a variable. Modifications take
5786 * Automatic SunOS shared library reading
5788 When you run your program, GDB automatically determines where its
5789 shared libraries (if any) have been loaded, and reads their symbols.
5790 The `share' command is no longer needed. This also works when
5791 examining core files.
5795 You can specify the number of lines that the `list' command shows.
5798 * New machines supported (host and target)
5800 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5801 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5802 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5804 * New hosts supported (not targets)
5806 IBM RT/PC: romp-ibm-aix or rtpc
5808 * New targets supported (not hosts)
5810 AMD 29000 embedded with COFF a29k-none-coff
5811 AMD 29000 embedded with a.out a29k-none-aout
5812 Ultracomputer remote kernel debug a29k-nyu-kern
5814 * New remote interfaces
5820 *** Changes in GDB-4.0:
5824 Wide output is wrapped at good places to make the output more readable.
5826 Gdb now supports cross-debugging from a host machine of one type to a
5827 target machine of another type. Communication with the target system
5828 is over serial lines. The ``target'' command handles connecting to the
5829 remote system; the ``load'' command will download a program into the
5830 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5831 also supports debugging of realtime processes running under VxWorks,
5832 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5833 stub on the target system.
5835 New CPUs supported include the AMD 29000 and Intel 960.
5837 GDB now reads object files and symbol tables via a ``binary file''
5838 library, which allows a single copy of GDB to debug programs of multiple
5839 object file types such as a.out and coff.
5841 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5842 refcard.dvi and refcard.ps are available to format it).
5845 * Control-Variable user interface simplified
5847 All variables that control the operation of the debugger can be set
5848 by the ``set'' command, and displayed by the ``show'' command.
5850 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5851 ``Show prompt'' produces the response:
5852 Gdb's prompt is new-gdb=>.
5854 What follows are the NEW set commands. The command ``help set'' will
5855 print a complete list of old and new set commands. ``help set FOO''
5856 will give a longer description of the variable FOO. ``show'' will show
5857 all of the variable descriptions and their current settings.
5859 confirm on/off: Enables warning questions for operations that are
5860 hard to recover from, e.g. rerunning the program while
5861 it is already running. Default is ON.
5863 editing on/off: Enables EMACS style command line editing
5864 of input. Previous lines can be recalled with
5865 control-P, the current line can be edited with control-B,
5866 you can search for commands with control-R, etc.
5869 history filename NAME: NAME is where the gdb command history
5870 will be stored. The default is .gdb_history,
5871 or the value of the environment variable
5874 history size N: The size, in commands, of the command history. The
5875 default is 256, or the value of the environment variable
5878 history save on/off: If this value is set to ON, the history file will
5879 be saved after exiting gdb. If set to OFF, the
5880 file will not be saved. The default is OFF.
5882 history expansion on/off: If this value is set to ON, then csh-like
5883 history expansion will be performed on
5884 command line input. The default is OFF.
5886 radix N: Sets the default radix for input and output. It can be set
5887 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5888 in the current radix, so "set radix 10" is always a no-op.
5890 height N: This integer value is the number of lines on a page. Default
5891 is 24, the current `stty rows'' setting, or the ``li#''
5892 setting from the termcap entry matching the environment
5895 width N: This integer value is the number of characters on a line.
5896 Default is 80, the current `stty cols'' setting, or the ``co#''
5897 setting from the termcap entry matching the environment
5900 Note: ``set screensize'' is obsolete. Use ``set height'' and
5901 ``set width'' instead.
5903 print address on/off: Print memory addresses in various command displays,
5904 such as stack traces and structure values. Gdb looks
5905 more ``symbolic'' if you turn this off; it looks more
5906 ``machine level'' with it on. Default is ON.
5908 print array on/off: Prettyprint arrays. New convenient format! Default
5911 print demangle on/off: Print C++ symbols in "source" form if on,
5914 print asm-demangle on/off: Same, for assembler level printouts
5917 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5920 * Support for Epoch Environment.
5922 The epoch environment is a version of Emacs v18 with windowing. One
5923 new command, ``inspect'', is identical to ``print'', except that if you
5924 are running in the epoch environment, the value is printed in its own
5928 * Support for Shared Libraries
5930 GDB can now debug programs and core files that use SunOS shared libraries.
5931 Symbols from a shared library cannot be referenced
5932 before the shared library has been linked with the program (this
5933 happens after you type ``run'' and before the function main() is entered).
5934 At any time after this linking (including when examining core files
5935 from dynamically linked programs), gdb reads the symbols from each
5936 shared library when you type the ``sharedlibrary'' command.
5937 It can be abbreviated ``share''.
5939 sharedlibrary REGEXP: Load shared object library symbols for files
5940 matching a unix regular expression. No argument
5941 indicates to load symbols for all shared libraries.
5943 info sharedlibrary: Status of loaded shared libraries.
5948 A watchpoint stops execution of a program whenever the value of an
5949 expression changes. Checking for this slows down execution
5950 tremendously whenever you are in the scope of the expression, but is
5951 quite useful for catching tough ``bit-spreader'' or pointer misuse
5952 problems. Some machines such as the 386 have hardware for doing this
5953 more quickly, and future versions of gdb will use this hardware.
5955 watch EXP: Set a watchpoint (breakpoint) for an expression.
5957 info watchpoints: Information about your watchpoints.
5959 delete N: Deletes watchpoint number N (same as breakpoints).
5960 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5961 enable N: Re-enables watchpoint number N (same as breakpoints).
5964 * C++ multiple inheritance
5966 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5969 * C++ exception handling
5971 Gdb now supports limited C++ exception handling. Besides the existing
5972 ability to breakpoint on an exception handler, gdb can breakpoint on
5973 the raising of an exception (before the stack is peeled back to the
5976 catch FOO: If there is a FOO exception handler in the dynamic scope,
5977 set a breakpoint to catch exceptions which may be raised there.
5978 Multiple exceptions (``catch foo bar baz'') may be caught.
5980 info catch: Lists all exceptions which may be caught in the
5981 current stack frame.
5984 * Minor command changes
5986 The command ``call func (arg, arg, ...)'' now acts like the print
5987 command, except it does not print or save a value if the function's result
5988 is void. This is similar to dbx usage.
5990 The ``up'' and ``down'' commands now always print the frame they end up
5991 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5992 frames without printing.
5994 * New directory command
5996 'dir' now adds directories to the FRONT of the source search path.
5997 The path starts off empty. Source files that contain debug information
5998 about the directory in which they were compiled can be found even
5999 with an empty path; Sun CC and GCC include this information. If GDB can't
6000 find your source file in the current directory, type "dir .".
6002 * Configuring GDB for compilation
6004 For normal use, type ``./configure host''. See README or gdb.texinfo
6007 GDB now handles cross debugging. If you are remotely debugging between
6008 two different machines, type ``./configure host -target=targ''.
6009 Host is the machine where GDB will run; targ is the machine
6010 where the program that you are debugging will run.