1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.9
6 * GDB now honors the content of the file /proc/PID/coredump_filter
7 (PID is the process ID) on GNU/Linux systems. This file can be used
8 to specify the types of memory mappings that will be included in a
9 corefile. For more information, please refer to the manual page of
10 "core(5)". GDB also has a new command: "set use-coredump-filter
11 on|off". It allows to set whether GDB will read the content of the
12 /proc/PID/coredump_filter file when generating a corefile.
14 * The "info os" command on GNU/Linux can now display information on
16 "info os cpus" Listing of all cpus/cores on the system
18 * GDB has two new commands: "set serial parity odd|even|none" and
19 "show serial parity". These allows to set or show parity for the
22 * The "info source" command now displays the producer string if it was
23 present in the debug info. This typically includes the compiler version
24 and may include things like its command line arguments.
26 * The "info dll", an alias of the "info sharedlibrary" command,
27 is now available on all platforms.
29 * Directory names supplied to the "set sysroot" commands may be
30 prefixed with "target:" to tell GDB to access shared libraries from
31 the target system, be it local or remote. This replaces the prefix
32 "remote:". The default sysroot has been changed from "" to
33 "target:". "remote:" is automatically converted to "target:" for
34 backward compatibility.
36 * The system root specified by "set sysroot" will be prepended to the
37 filename of the main executable (if reported to GDB as absolute by
38 the operating system) when starting processes remotely, and when
39 attaching to already-running local or remote processes.
41 * GDB now supports automatic location and retrieval of executable
42 files from remote targets. Remote debugging can now be initiated
43 using only a "target remote" or "target extended-remote" command
44 (no "set sysroot" or "file" commands are required). See "New remote
47 * The "dump" command now supports verilog hex format.
49 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
53 ** gdb.Objfile objects have a new attribute "username",
54 which is the name of the objfile as specified by the user,
55 without, for example, resolving symlinks.
56 ** You can now write frame unwinders in Python.
57 ** gdb.Type objects have a new method "optimized_out",
58 returning optimized out gdb.Value instance of this type.
59 ** gdb.Value objects have new methods "reference_value" and
60 "const_value" which return a reference to the value and a
61 "const" version of the value respectively.
65 maint print symbol-cache
66 Print the contents of the symbol cache.
68 maint print symbol-cache-statistics
69 Print statistics of symbol cache usage.
71 maint flush-symbol-cache
72 Flush the contents of the symbol cache.
76 Start branch trace recording using Branch Trace Store (BTS) format.
79 Evaluate expression by using the compiler and print result.
85 Set the maximum number of candidates to be considered during
86 completion. The default value is 200. This limit allows GDB
87 to avoid generating large completion lists, the computation of
88 which can cause the debugger to become temporarily unresponsive.
90 maint set symbol-cache-size
91 maint show symbol-cache-size
92 Control the size of the symbol cache.
94 set|show record btrace bts buffer-size
95 Set and show the size of the ring buffer used for branch tracing in
97 The obtained size may differ from the requested size. Use "info
98 record" to see the obtained buffer size.
100 * The command 'thread apply all' can now support new option '-ascending'
101 to call its specified command for all threads in ascending order.
103 * Python/Guile scripting
105 ** GDB now supports auto-loading of Python/Guile scripts contained in the
106 special section named `.debug_gdb_scripts'.
110 qXfer:btrace-conf:read
111 Return the branch trace configuration for the current thread.
113 Qbtrace-conf:bts:size
114 Set the requested ring buffer size for branch tracing in BTS format.
117 Indicates a memory breakpoint instruction was executed, irrespective
118 of whether it was GDB that planted the breakpoint or the breakpoint
119 is hardcoded in the program. This is required for correct non-stop
123 Indicates the target stopped for a hardware breakpoint. This is
124 required for correct non-stop mode operation.
127 Return information about files on the remote system.
130 Return the full absolute name of the file that was executed to
131 create a process running on the remote system.
134 Indicates that a fork system call was executed.
137 Indicates that a vfork system call was executed.
139 vforkdone stop reason
140 Indicates that a vfork child of the specified process has executed
141 an exec or exit, allowing the vfork parent to resume execution.
143 fork-events and vfork-events features in qSupported
144 The qSupported packet allows GDB to request support for fork and
145 vfork events using new 'gdbfeatures' fork-events and vfork-events,
146 and the qSupported response can contain the corresponding
147 'stubfeatures'. Set and show commands can be used to display
148 whether these features are enabled.
150 * Extended-remote fork events
152 ** GDB now has support for fork events on extended-remote Linux
153 targets. For targets with Linux kernels 2.5.60 and later, this
154 enables follow-fork-mode and detach-on-fork for both fork and
155 vfork, as well as fork and vfork catchpoints.
157 * The info record command now shows the recording format and the
158 branch tracing configuration for the current thread when using
159 the btrace record target.
160 For the BTS format, it shows the ring buffer size.
162 * GDB now has support for DTrace USDT (Userland Static Defined
163 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
165 * GDB now supports access to vector registers on S/390 GNU/Linux
168 * Removed command line options
170 -xdb HP-UX XDB compatibility mode.
172 * Removed targets and native configurations
174 HP/PA running HP-UX hppa*-*-hpux*
175 Itanium running HP-UX ia64-*-hpux*
177 *** Changes in GDB 7.9.1
181 ** Xmethods can now specify a result type.
183 *** Changes in GDB 7.9
185 * GDB now supports hardware watchpoints on x86 GNU Hurd.
189 ** You can now access frame registers from Python scripts.
190 ** New attribute 'producer' for gdb.Symtab objects.
191 ** gdb.Objfile objects have a new attribute "progspace",
192 which is the gdb.Progspace object of the containing program space.
193 ** gdb.Objfile objects have a new attribute "owner".
194 ** gdb.Objfile objects have a new attribute "build_id",
195 which is the build ID generated when the file was built.
196 ** gdb.Objfile objects have a new method "add_separate_debug_file".
197 ** A new event "gdb.clear_objfiles" has been added, triggered when
198 selecting a new file to debug.
199 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
200 ** New function gdb.lookup_objfile.
202 New events which are triggered when GDB modifies the state of the
205 ** gdb.events.inferior_call_pre: Function call is about to be made.
206 ** gdb.events.inferior_call_post: Function call has just been made.
207 ** gdb.events.memory_changed: A memory location has been altered.
208 ** gdb.events.register_changed: A register has been altered.
210 * New Python-based convenience functions:
212 ** $_caller_is(name [, number_of_frames])
213 ** $_caller_matches(regexp [, number_of_frames])
214 ** $_any_caller_is(name [, number_of_frames])
215 ** $_any_caller_matches(regexp [, number_of_frames])
217 * GDB now supports the compilation and injection of source code into
218 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
219 to compile the source code to object code, and if successful, inject
220 and execute that code within the current context of the inferior.
221 Currently the C language is supported. The commands used to
222 interface with this new feature are:
224 compile code [-raw|-r] [--] [source code]
225 compile file [-raw|-r] filename
229 demangle [-l language] [--] name
230 Demangle "name" in the specified language, or the current language
231 if elided. This command is renamed from the "maint demangle" command.
232 The latter is kept as a no-op to avoid "maint demangle" being interpreted
233 as "maint demangler-warning".
235 queue-signal signal-name-or-number
236 Queue a signal to be delivered to the thread when it is resumed.
238 add-auto-load-scripts-directory directory
239 Add entries to the list of directories from which to load auto-loaded
242 maint print user-registers
243 List all currently available "user" registers.
245 compile code [-r|-raw] [--] [source code]
246 Compile, inject, and execute in the inferior the executable object
247 code produced by compiling the provided source code.
249 compile file [-r|-raw] filename
250 Compile and inject into the inferior the executable object code
251 produced by compiling the source code stored in the filename
254 * On resume, GDB now always passes the signal the program had stopped
255 for to the thread the signal was sent to, even if the user changed
256 threads before resuming. Previously GDB would often (but not
257 always) deliver the signal to the thread that happens to be current
260 * Conversely, the "signal" command now consistently delivers the
261 requested signal to the current thread. GDB now asks for
262 confirmation if the program had stopped for a signal and the user
263 switched threads meanwhile.
265 * "breakpoint always-inserted" modes "off" and "auto" merged.
267 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
268 won't remove breakpoints from the target until all threads stop,
269 even in non-stop mode. The "auto" mode has been removed, and "off"
270 is now the default mode.
274 set debug symbol-lookup
275 show debug symbol-lookup
276 Control display of debugging info regarding symbol lookup.
280 ** The -list-thread-groups command outputs an exit-code field for
281 inferiors that have exited.
285 MIPS SDE mips*-sde*-elf*
289 Support for these obsolete configurations has been removed.
291 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
292 SGI Irix-5.x mips-*-irix5*
293 SGI Irix-6.x mips-*-irix6*
294 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
295 VAX running Ultrix vax-*-ultrix*
297 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
298 and "assf"), have been removed. Use the "sharedlibrary" command, or
299 its alias "share", instead.
301 *** Changes in GDB 7.8
303 * New command line options
306 This is an alias for the --data-directory option.
308 * GDB supports printing and modifying of variable length automatic arrays
309 as specified in ISO C99.
311 * The ARM simulator now supports instruction level tracing
312 with or without disassembly.
316 GDB now has support for scripting using Guile. Whether this is
317 available is determined at configure time.
318 Guile version 2.0 or greater is required.
319 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
321 * New commands (for set/show, see "New options" below)
325 Invoke CODE by passing it to the Guile interpreter.
329 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
331 info auto-load guile-scripts [regexp]
332 Print the list of automatically loaded Guile scripts.
334 * The source command is now capable of sourcing Guile scripts.
335 This feature is dependent on the debugger being built with Guile support.
339 set print symbol-loading (off|brief|full)
340 show print symbol-loading
341 Control whether to print informational messages when loading symbol
342 information for a file. The default is "full", but when debugging
343 programs with large numbers of shared libraries the amount of output
346 set guile print-stack (none|message|full)
347 show guile print-stack
348 Show a stack trace when an error is encountered in a Guile script.
350 set auto-load guile-scripts (on|off)
351 show auto-load guile-scripts
352 Control auto-loading of Guile script files.
354 maint ada set ignore-descriptive-types (on|off)
355 maint ada show ignore-descriptive-types
356 Control whether the debugger should ignore descriptive types in Ada
357 programs. The default is not to ignore the descriptive types. See
358 the user manual for more details on descriptive types and the intended
359 usage of this option.
361 set auto-connect-native-target
363 Control whether GDB is allowed to automatically connect to the
364 native target for the run, attach, etc. commands when not connected
365 to any target yet. See also "target native" below.
367 set record btrace replay-memory-access (read-only|read-write)
368 show record btrace replay-memory-access
369 Control what memory accesses are allowed during replay.
371 maint set target-async (on|off)
372 maint show target-async
373 This controls whether GDB targets operate in synchronous or
374 asynchronous mode. Normally the default is asynchronous, if it is
375 available; but this can be changed to more easily debug problems
376 occurring only in synchronous mode.
378 set mi-async (on|off)
380 Control whether MI asynchronous mode is preferred. This supersedes
381 "set target-async" of previous GDB versions.
383 * "set target-async" is deprecated as a CLI option and is now an alias
384 for "set mi-async" (only puts MI into async mode).
386 * Background execution commands (e.g., "c&", "s&", etc.) are now
387 possible ``out of the box'' if the target supports them. Previously
388 the user would need to explicitly enable the possibility with the
389 "set target-async on" command.
391 * New features in the GDB remote stub, GDBserver
393 ** New option --debug-format=option1[,option2,...] allows one to add
394 additional text to each output. At present only timestamps
395 are supported: --debug-format=timestamps.
396 Timestamps can also be turned on with the
397 "monitor set debug-format timestamps" command from GDB.
399 * The 'record instruction-history' command now starts counting instructions
400 at one. This also affects the instruction ranges reported by the
401 'record function-call-history' command when given the /i modifier.
403 * The command 'record function-call-history' supports a new modifier '/c' to
404 indent the function names based on their call stack depth.
405 The fields for the '/i' and '/l' modifier have been reordered.
406 The source line range is now prefixed with 'at'.
407 The instruction range is now prefixed with 'inst'.
408 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
409 "record instruction-history" and "list" commands.
411 * The ranges given as arguments to the 'record function-call-history' and
412 'record instruction-history' commands are now inclusive.
414 * The btrace record target now supports the 'record goto' command.
415 For locations inside the execution trace, the back trace is computed
416 based on the information stored in the execution trace.
418 * The btrace record target supports limited reverse execution and replay.
419 The target does not record data and therefore does not allow reading
422 * The "catch syscall" command now works on s390*-linux* targets.
424 * The "compare-sections" command is no longer specific to target
425 remote. It now works with all targets.
427 * All native targets are now consistently called "native".
428 Consequently, the "target child", "target GNU", "target djgpp",
429 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
430 commands have been replaced with "target native". The QNX/NTO port
431 leaves the "procfs" target in place and adds a "native" target for
432 consistency with other ports. The impact on users should be minimal
433 as these commands previously either throwed an error, or were
434 no-ops. The target's name is visible in the output of the following
435 commands: "help target", "info target", "info files", "maint print
438 * The "target native" command now connects to the native target. This
439 can be used to launch native programs even when "set
440 auto-connect-native-target" is set to off.
442 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.
444 * Support for Intel(R) AVX-512 registers on GNU/Linux.
445 Support displaying and modifying Intel(R) AVX-512 registers
446 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
450 qXfer:btrace:read's annex
451 The qXfer:btrace:read packet supports a new annex 'delta' to read
452 branch trace incrementally.
456 ** Valid Python operations on gdb.Value objects representing
457 structs/classes invoke the corresponding overloaded operators if
459 ** New `Xmethods' feature in the Python API. Xmethods are
460 additional methods or replacements for existing methods of a C++
461 class. This feature is useful for those cases where a method
462 defined in C++ source code could be inlined or optimized out by
463 the compiler, making it unavailable to GDB.
466 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
468 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
469 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
470 its alias "share", instead.
472 * The commands "set remotebaud" and "show remotebaud" are no longer
473 supported. Use "set serial baud" and "show serial baud" (respectively)
478 ** A new option "-gdb-set mi-async" replaces "-gdb-set
479 target-async". The latter is left as a deprecated alias of the
480 former for backward compatibility. If the target supports it,
481 CLI background execution commands are now always possible by
482 default, independently of whether the frontend stated a
483 preference for asynchronous execution with "-gdb-set mi-async".
484 Previously "-gdb-set target-async off" affected both MI execution
485 commands and CLI execution commands.
487 *** Changes in GDB 7.7
489 * Improved support for process record-replay and reverse debugging on
490 arm*-linux* targets. Support for thumb32 and syscall instruction
491 recording has been added.
493 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
495 * GDB now supports Fission DWP file format version 2.
496 http://gcc.gnu.org/wiki/DebugFission
498 * New convenience function "$_isvoid", to check whether an expression
499 is void. A void expression is an expression where the type of the
500 result is "void". For example, some convenience variables may be
501 "void" when evaluated (e.g., "$_exitcode" before the execution of
502 the program being debugged; or an undefined convenience variable).
503 Another example, when calling a function whose return type is
506 * The "maintenance print objfiles" command now takes an optional regexp.
508 * The "catch syscall" command now works on arm*-linux* targets.
510 * GDB now consistently shows "<not saved>" when printing values of
511 registers the debug info indicates have not been saved in the frame
512 and there's nowhere to retrieve them from
513 (callee-saved/call-clobbered registers):
518 (gdb) info registers rax
521 Before, the former would print "<optimized out>", and the latter
522 "*value not available*".
524 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
529 ** Frame filters and frame decorators have been added.
530 ** Temporary breakpoints are now supported.
531 ** Line tables representation has been added.
532 ** New attribute 'parent_type' for gdb.Field objects.
533 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
534 ** New attribute 'name' for gdb.Type objects.
538 Nios II ELF nios2*-*-elf
539 Nios II GNU/Linux nios2*-*-linux
540 Texas Instruments MSP430 msp430*-*-elf
542 * Removed native configurations
544 Support for these a.out NetBSD and OpenBSD obsolete configurations has
545 been removed. ELF variants of these configurations are kept supported.
547 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
548 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
549 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
550 i[34567]86-*-openbsd3.[0-3]
551 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
552 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
553 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
557 Like "catch throw", but catches a re-thrown exception.
559 Renamed from old "maint check-symtabs".
561 Perform consistency checks on symtabs.
563 Expand symtabs matching an optional regexp.
566 Display the details of GDB configure-time options.
568 maint set|show per-command
569 maint set|show per-command space
570 maint set|show per-command time
571 maint set|show per-command symtab
572 Enable display of per-command gdb resource usage.
574 remove-symbol-file FILENAME
575 remove-symbol-file -a ADDRESS
576 Remove a symbol file added via add-symbol-file. The file to remove
577 can be identified by its filename or by an address that lies within
578 the boundaries of this symbol file in memory.
581 info exceptions REGEXP
582 Display the list of Ada exceptions defined in the program being
583 debugged. If provided, only the exceptions whose names match REGEXP
588 set debug symfile off|on
590 Control display of debugging info regarding reading symbol files and
591 symbol tables within those files
593 set print raw frame-arguments
594 show print raw frame-arguments
595 Set/show whether to print frame arguments in raw mode,
596 disregarding any defined pretty-printers.
598 set remote trace-status-packet
599 show remote trace-status-packet
600 Set/show the use of remote protocol qTStatus packet.
604 Control display of debugging messages related to Nios II targets.
608 Control whether target-assisted range stepping is enabled.
610 set startup-with-shell
611 show startup-with-shell
612 Specifies whether Unix child processes are started via a shell or
617 Use the target memory cache for accesses to the code segment. This
618 improves performance of remote debugging (particularly disassembly).
620 * You can now use a literal value 'unlimited' for options that
621 interpret 0 or -1 as meaning "unlimited". E.g., "set
622 trace-buffer-size unlimited" is now an alias for "set
623 trace-buffer-size -1" and "set height unlimited" is now an alias for
626 * The "set debug symtab-create" debugging option of GDB has been changed to
627 accept a verbosity level. 0 means "off", 1 provides basic debugging
628 output, and values of 2 or greater provides more verbose output.
630 * New command-line options
632 Display the details of GDB configure-time options.
634 * The command 'tsave' can now support new option '-ctf' to save trace
635 buffer in Common Trace Format.
637 * Newly installed $prefix/bin/gcore acts as a shell interface for the
640 * GDB now implements the the C++ 'typeid' operator.
642 * The new convenience variable $_exception holds the exception being
643 thrown or caught at an exception-related catchpoint.
645 * The exception-related catchpoints, like "catch throw", now accept a
646 regular expression which can be used to filter exceptions by type.
648 * The new convenience variable $_exitsignal is automatically set to
649 the terminating signal number when the program being debugged dies
650 due to an uncaught signal.
654 ** All MI commands now accept an optional "--language" option.
655 Support for this feature can be verified by using the "-list-features"
656 command, which should contain "language-option".
658 ** The new command -info-gdb-mi-command allows the user to determine
659 whether a GDB/MI command is supported or not.
661 ** The "^error" result record returned when trying to execute an undefined
662 GDB/MI command now provides a variable named "code" whose content is the
663 "undefined-command" error code. Support for this feature can be verified
664 by using the "-list-features" command, which should contain
665 "undefined-command-error-code".
667 ** The -trace-save MI command can optionally save trace buffer in Common
670 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
672 ** The command -data-list-register-values now accepts an optional
673 "--skip-unavailable" option. When used, only the available registers
676 ** The new command -trace-frame-collected dumps collected variables,
677 computed expressions, tvars, memory and registers in a traceframe.
679 ** The commands -stack-list-locals, -stack-list-arguments and
680 -stack-list-variables now accept an option "--skip-unavailable".
681 When used, only the available locals or arguments are displayed.
683 ** The -exec-run command now accepts an optional "--start" option.
684 When used, the command follows the same semantics as the "start"
685 command, stopping the program's execution at the start of its
686 main subprogram. Support for this feature can be verified using
687 the "-list-features" command, which should contain
688 "exec-run-start-option".
690 ** The new commands -catch-assert and -catch-exceptions insert
691 catchpoints stopping the program when Ada exceptions are raised.
693 ** The new command -info-ada-exceptions provides the equivalent of
694 the new "info exceptions" command.
696 * New system-wide configuration scripts
697 A GDB installation now provides scripts suitable for use as system-wide
698 configuration scripts for the following systems:
702 * GDB now supports target-assigned range stepping with remote targets.
703 This improves the performance of stepping source lines by reducing
704 the number of control packets from/to GDB. See "New remote packets"
707 * GDB now understands the element 'tvar' in the XML traceframe info.
708 It has the id of the collected trace state variables.
710 * On S/390 targets that provide the transactional-execution feature,
711 the program interruption transaction diagnostic block (TDB) is now
712 represented as a number of additional "registers" in GDB.
718 The vCont packet supports a new 'r' action, that tells the remote
719 stub to step through an address range itself, without GDB
720 involvemement at each single-step.
722 qXfer:libraries-svr4:read's annex
723 The previously unused annex of the qXfer:libraries-svr4:read packet
724 is now used to support passing an argument list. The remote stub
725 reports support for this argument list to GDB's qSupported query.
726 The defined arguments are "start" and "prev", used to reduce work
727 necessary for library list updating, resulting in significant
730 * New features in the GDB remote stub, GDBserver
732 ** GDBserver now supports target-assisted range stepping. Currently
733 enabled on x86/x86_64 GNU/Linux targets.
735 ** GDBserver now adds element 'tvar' in the XML in the reply to
736 'qXfer:traceframe-info:read'. It has the id of the collected
737 trace state variables.
739 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
742 * New 'z' formatter for printing and examining memory, this displays the
743 value as hexadecimal zero padded on the left to the size of the type.
745 * GDB can now use Windows x64 unwinding data.
747 * The "set remotebaud" command has been replaced by "set serial baud".
748 Similarly, "show remotebaud" has been replaced by "show serial baud".
749 The "set remotebaud" and "show remotebaud" commands are still available
750 to provide backward compatibility with older versions of GDB.
752 *** Changes in GDB 7.6
754 * Target record has been renamed to record-full.
755 Record/replay is now enabled with the "record full" command.
756 This also affects settings that are associated with full record/replay
757 that have been moved from "set/show record" to "set/show record full":
759 set|show record full insn-number-max
760 set|show record full stop-at-limit
761 set|show record full memory-query
763 * A new record target "record-btrace" has been added. The new target
764 uses hardware support to record the control-flow of a process. It
765 does not support replaying the execution, but it implements the
766 below new commands for investigating the recorded execution log.
767 This new recording method can be enabled using:
771 The "record-btrace" target is only available on Intel Atom processors
772 and requires a Linux kernel 2.6.32 or later.
774 * Two new commands have been added for record/replay to give information
775 about the recorded execution without having to replay the execution.
776 The commands are only supported by "record btrace".
778 record instruction-history prints the execution history at
779 instruction granularity
781 record function-call-history prints the execution history at
784 * New native configurations
786 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
787 FreeBSD/powerpc powerpc*-*-freebsd
788 x86_64/Cygwin x86_64-*-cygwin*
789 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
793 ARM AArch64 aarch64*-*-elf
794 ARM AArch64 GNU/Linux aarch64*-*-linux
795 Lynx 178 PowerPC powerpc-*-lynx*178
796 x86_64/Cygwin x86_64-*-cygwin*
797 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
799 * If the configured location of system.gdbinit file (as given by the
800 --with-system-gdbinit option at configure time) is in the
801 data-directory (as specified by --with-gdb-datadir at configure
802 time) or in one of its subdirectories, then GDB will look for the
803 system-wide init file in the directory specified by the
804 --data-directory command-line option.
806 * New command line options:
808 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
809 other initialization files, unlike -nx which disables all of them.
811 * Removed command line options
813 -epoch This was used by the gdb mode in Epoch, an ancient fork of
816 * The 'ptype' and 'whatis' commands now accept an argument to control
819 * 'info proc' now works on some core files.
823 ** Vectors can be created with gdb.Type.vector.
825 ** Python's atexit.register now works in GDB.
827 ** Types can be pretty-printed via a Python API.
829 ** Python 3 is now supported (in addition to Python 2.4 or later)
831 ** New class gdb.Architecture exposes GDB's internal representation
832 of architecture in the Python API.
834 ** New method Frame.architecture returns the gdb.Architecture object
835 corresponding to the frame's architecture.
837 * New Python-based convenience functions:
839 ** $_memeq(buf1, buf2, length)
840 ** $_streq(str1, str2)
842 ** $_regex(str, regex)
844 * The 'cd' command now defaults to using '~' (the home directory) if not
847 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
848 default for GCC since November 2000.
850 * The command 'forward-search' can now be abbreviated as 'fo'.
852 * The command 'info tracepoints' can now display 'installed on target'
853 or 'not installed on target' for each non-pending location of tracepoint.
855 * New configure options
857 --enable-libmcheck/--disable-libmcheck
858 By default, development versions are built with -lmcheck on hosts
859 that support it, in order to help track memory corruption issues.
860 Release versions, on the other hand, are built without -lmcheck
861 by default. The --enable-libmcheck/--disable-libmcheck configure
862 options allow the user to override that default.
863 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
864 This configure option allows the user to build GDB with
865 libbabeltrace using which GDB can read Common Trace Format data.
867 * New commands (for set/show, see "New options" below)
870 Catch signals. This is similar to "handle", but allows commands and
871 conditions to be attached.
874 List the BFDs known to GDB.
876 python-interactive [command]
878 Start a Python interactive prompt, or evaluate the optional command
879 and print the result of expressions.
882 "py" is a new alias for "python".
884 enable type-printer [name]...
885 disable type-printer [name]...
886 Enable or disable type printers.
890 ** For the Renesas Super-H architecture, the "regs" command has been removed
891 (has been deprecated in GDB 7.5), and "info all-registers" should be used
896 set print type methods (on|off)
897 show print type methods
898 Control whether method declarations are displayed by "ptype".
899 The default is to show them.
901 set print type typedefs (on|off)
902 show print type typedefs
903 Control whether typedef definitions are displayed by "ptype".
904 The default is to show them.
906 set filename-display basename|relative|absolute
907 show filename-display
908 Control the way in which filenames is displayed.
909 The default is "relative", which preserves previous behavior.
911 set trace-buffer-size
912 show trace-buffer-size
913 Request target to change the size of trace buffer.
915 set remote trace-buffer-size-packet auto|on|off
916 show remote trace-buffer-size-packet
917 Control the use of the remote protocol `QTBuffer:size' packet.
921 Control display of debugging messages related to ARM AArch64.
924 set debug coff-pe-read
925 show debug coff-pe-read
926 Control display of debugging messages related to reading of COFF/PE
931 Control display of debugging messages related to Mach-O symbols
934 set debug notification
935 show debug notification
936 Control display of debugging info for async remote notification.
940 ** Command parameter changes are now notified using new async record
941 "=cmd-param-changed".
942 ** Trace frame changes caused by command "tfind" are now notified using
943 new async record "=traceframe-changed".
944 ** The creation, deletion and modification of trace state variables
945 are now notified using new async records "=tsv-created",
946 "=tsv-deleted" and "=tsv-modified".
947 ** The start and stop of process record are now notified using new
948 async record "=record-started" and "=record-stopped".
949 ** Memory changes are now notified using new async record
951 ** The data-disassemble command response will include a "fullname" field
952 containing the absolute file name when source has been requested.
953 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
954 command, to allow pattern filling of memory areas.
955 ** New commands "-catch-load"/"-catch-unload" added for intercepting
956 library load/unload events.
957 ** The response to breakpoint commands and breakpoint async records
958 includes an "installed" field containing a boolean state about each
959 non-pending tracepoint location is whether installed on target or not.
960 ** Output of the "-trace-status" command includes a "trace-file" field
961 containing the name of the trace file being examined. This field is
962 optional, and only present when examining a trace file.
963 ** The "fullname" field is now always present along with the "file" field,
964 even if the file cannot be found by GDB.
966 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
967 You must have the LZMA library available when configuring GDB for this
968 feature to be enabled. For more information, see:
969 http://fedoraproject.org/wiki/Features/MiniDebugInfo
974 Set the size of trace buffer. The remote stub reports support for this
975 packet to gdb's qSupported query.
978 Enable Branch Trace Store (BTS)-based branch tracing for the current
979 thread. The remote stub reports support for this packet to gdb's
983 Disable branch tracing for the current thread. The remote stub reports
984 support for this packet to gdb's qSupported query.
987 Read the traced branches for the current thread. The remote stub
988 reports support for this packet to gdb's qSupported query.
990 *** Changes in GDB 7.5
992 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
993 for more x32 ABI info.
995 * GDB now supports access to MIPS DSP registers on Linux targets.
997 * GDB now supports debugging microMIPS binaries.
999 * The "info os" command on GNU/Linux can now display information on
1000 several new classes of objects managed by the operating system:
1001 "info os procgroups" lists process groups
1002 "info os files" lists file descriptors
1003 "info os sockets" lists internet-domain sockets
1004 "info os shm" lists shared-memory regions
1005 "info os semaphores" lists semaphores
1006 "info os msg" lists message queues
1007 "info os modules" lists loaded kernel modules
1009 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1010 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1011 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1012 options and inspect the probe arguments using the new $_probe_arg family
1013 of convenience variables. You can obtain more information about SystemTap
1014 in <http://sourceware.org/systemtap/>.
1016 * GDB now supports reversible debugging on ARM, it allows you to
1017 debug basic ARM and THUMB instructions, and provides
1018 record/replay support.
1020 * The option "symbol-reloading" has been deleted as it is no longer used.
1024 ** GDB commands implemented in Python can now be put in command class
1027 ** The "maint set python print-stack on|off" is now deleted.
1029 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1030 apply "flag enum"-style pretty-printing to any enum.
1032 ** gdb.lookup_symbol can now work when there is no current frame.
1034 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1035 the source at which the symbol was defined.
1037 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1038 method 'value'. The former indicates whether the symbol needs a
1039 frame in order to compute its value, and the latter computes the
1042 ** A new method 'referenced_value' on gdb.Value objects which can
1043 dereference pointer as well as C++ reference values.
1045 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1046 which return the global and static blocks (as gdb.Block objects),
1047 of the underlying symbol table, respectively.
1049 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1050 object associated with a PC value.
1052 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1053 of the address range occupied by code for the current source line.
1055 * Go language support.
1056 GDB now supports debugging programs written in the Go programming
1059 * GDBserver now supports stdio connections.
1060 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1062 * The binary "gdbtui" can no longer be built or installed.
1063 Use "gdb -tui" instead.
1065 * GDB will now print "flag" enums specially. A flag enum is one where
1066 all the enumerator values have no bits in common when pairwise
1067 "and"ed. When printing a value whose type is a flag enum, GDB will
1068 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1069 (gdb) print (enum E) 3
1072 * The filename part of a linespec will now match trailing components
1073 of a source file name. For example, "break gcc/expr.c:1000" will
1074 now set a breakpoint in build/gcc/expr.c, but not
1075 build/libcpp/expr.c.
1077 * The "info proc" and "generate-core-file" commands will now also
1078 work on remote targets connected to GDBserver on Linux.
1080 * The command "info catch" has been removed. It has been disabled
1081 since December 2007.
1083 * The "catch exception" and "catch assert" commands now accept
1084 a condition at the end of the command, much like the "break"
1085 command does. For instance:
1087 (gdb) catch exception Constraint_Error if Barrier = True
1089 Previously, it was possible to add a condition to such catchpoints,
1090 but it had to be done as a second step, after the catchpoint had been
1091 created, using the "condition" command.
1093 * The "info static-tracepoint-marker" command will now also work on
1094 native Linux targets with in-process agent.
1096 * GDB can now set breakpoints on inlined functions.
1098 * The .gdb_index section has been updated to include symbols for
1099 inlined functions. GDB will ignore older .gdb_index sections by
1100 default, which could cause symbol files to be loaded more slowly
1101 until their .gdb_index sections can be recreated. The new command
1102 "set use-deprecated-index-sections on" will cause GDB to use any older
1103 .gdb_index sections it finds. This will restore performance, but the
1104 ability to set breakpoints on inlined functions will be lost in symbol
1105 files with older .gdb_index sections.
1107 The .gdb_index section has also been updated to record more information
1108 about each symbol. This speeds up the "info variables", "info functions"
1109 and "info types" commands when used with programs having the .gdb_index
1110 section, as well as speeding up debugging with shared libraries using
1111 the .gdb_index section.
1113 * Ada support for GDB/MI Variable Objects has been added.
1115 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1120 ** New command -info-os is the MI equivalent of "info os".
1122 ** Output logs ("set logging" and related) now include MI output.
1126 ** "set use-deprecated-index-sections on|off"
1127 "show use-deprecated-index-sections on|off"
1128 Controls the use of deprecated .gdb_index sections.
1130 ** "catch load" and "catch unload" can be used to stop when a shared
1131 library is loaded or unloaded, respectively.
1133 ** "enable count" can be used to auto-disable a breakpoint after
1136 ** "info vtbl" can be used to show the virtual method tables for
1137 C++ and Java objects.
1139 ** "explore" and its sub commands "explore value" and "explore type"
1140 can be used to recursively explore values and types of
1141 expressions. These commands are available only if GDB is
1142 configured with '--with-python'.
1144 ** "info auto-load" shows status of all kinds of auto-loaded files,
1145 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1146 sequences of commands files, "info auto-load python-scripts"
1147 shows status of auto-loading Python script files,
1148 "info auto-load local-gdbinit" shows status of loading init file
1149 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1150 status of inferior specific thread debugging shared library loading.
1152 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1153 and "show auto-load-scripts" commands have been deprecated, use their
1154 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1155 and "show auto-load python-scripts" counterparts instead.
1157 ** "dprintf location,format,args..." creates a dynamic printf, which
1158 is basically a breakpoint that does a printf and immediately
1159 resumes your program's execution, so it is like a printf that you
1160 can insert dynamically at runtime instead of at compiletime.
1162 ** "set print symbol"
1164 Controls whether GDB attempts to display the symbol, if any,
1165 corresponding to addresses it prints. This defaults to "on", but
1166 you can set it to "off" to restore GDB's previous behavior.
1168 * Deprecated commands
1170 ** For the Renesas Super-H architecture, the "regs" command has been
1171 deprecated, and "info all-registers" should be used instead.
1175 Renesas RL78 rl78-*-elf
1176 HP OpenVMS ia64 ia64-hp-openvms*
1178 * GDBserver supports evaluation of breakpoint conditions. When
1179 support is advertised by GDBserver, GDB may be told to send the
1180 breakpoint conditions in bytecode form to GDBserver. GDBserver
1181 will only report the breakpoint trigger to GDB when its condition
1186 set mips compression
1187 show mips compression
1188 Select the compressed ISA encoding used in functions that have no symbol
1189 information available. The encoding can be set to either of:
1192 and is updated automatically from ELF file flags if available.
1194 set breakpoint condition-evaluation
1195 show breakpoint condition-evaluation
1196 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1197 GDBserver ("target"). Default option "auto" chooses the most efficient
1199 This option can improve debugger efficiency depending on the speed of the
1203 Disable auto-loading globally.
1206 Show auto-loading setting of all kinds of auto-loaded files.
1208 set auto-load gdb-scripts on|off
1209 show auto-load gdb-scripts
1210 Control auto-loading of GDB canned sequences of commands files.
1212 set auto-load python-scripts on|off
1213 show auto-load python-scripts
1214 Control auto-loading of Python script files.
1216 set auto-load local-gdbinit on|off
1217 show auto-load local-gdbinit
1218 Control loading of init file (.gdbinit) from current directory.
1220 set auto-load libthread-db on|off
1221 show auto-load libthread-db
1222 Control auto-loading of inferior specific thread debugging shared library.
1224 set auto-load scripts-directory <dir1>[:<dir2>...]
1225 show auto-load scripts-directory
1226 Set a list of directories from which to load auto-loaded scripts.
1227 Automatically loaded Python scripts and GDB scripts are located in one
1228 of the directories listed by this option.
1229 The delimiter (':' above) may differ according to the host platform.
1231 set auto-load safe-path <dir1>[:<dir2>...]
1232 show auto-load safe-path
1233 Set a list of directories from which it is safe to auto-load files.
1234 The delimiter (':' above) may differ according to the host platform.
1236 set debug auto-load on|off
1237 show debug auto-load
1238 Control display of debugging info for auto-loading the files above.
1240 set dprintf-style gdb|call|agent
1242 Control the way in which a dynamic printf is performed; "gdb"
1243 requests a GDB printf command, while "call" causes dprintf to call a
1244 function in the inferior. "agent" requests that the target agent
1245 (such as GDBserver) do the printing.
1247 set dprintf-function <expr>
1248 show dprintf-function
1249 set dprintf-channel <expr>
1250 show dprintf-channel
1251 Set the function and optional first argument to the call when using
1252 the "call" style of dynamic printf.
1254 set disconnected-dprintf on|off
1255 show disconnected-dprintf
1256 Control whether agent-style dynamic printfs continue to be in effect
1257 after GDB disconnects.
1259 * New configure options
1261 --with-auto-load-dir
1262 Configure default value for the 'set auto-load scripts-directory'
1263 setting above. It defaults to '$debugdir:$datadir/auto-load',
1264 $debugdir representing global debugging info directories (available
1265 via 'show debug-file-directory') and $datadir representing GDB's data
1266 directory (available via 'show data-directory').
1268 --with-auto-load-safe-path
1269 Configure default value for the 'set auto-load safe-path' setting
1270 above. It defaults to the --with-auto-load-dir setting.
1272 --without-auto-load-safe-path
1273 Set 'set auto-load safe-path' to '/', effectively disabling this
1276 * New remote packets
1278 z0/z1 conditional breakpoints extension
1280 The z0/z1 breakpoint insertion packets have been extended to carry
1281 a list of conditional expressions over to the remote stub depending on the
1282 condition evaluation mode. The use of this extension can be controlled
1283 via the "set remote conditional-breakpoints-packet" command.
1287 Specify the signals which the remote stub may pass to the debugged
1288 program without GDB involvement.
1290 * New command line options
1292 --init-command=FILE, -ix Like --command, -x but execute it
1293 before loading inferior.
1294 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1295 execute it before loading inferior.
1297 *** Changes in GDB 7.4
1299 * GDB now handles ambiguous linespecs more consistently; the existing
1300 FILE:LINE support has been expanded to other types of linespecs. A
1301 breakpoint will now be set on all matching locations in all
1302 inferiors, and locations will be added or removed according to
1305 * GDB now allows you to skip uninteresting functions and files when
1306 stepping with the "skip function" and "skip file" commands.
1308 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1309 and "show remote hardware-watchpoint-length-limit". These allows to
1310 set or show the maximum length limit (in bytes) of a remote
1311 target hardware watchpoint.
1313 This allows e.g. to use "unlimited" hardware watchpoints with the
1314 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1315 watchpoints are slower than real hardware watchpoints but are
1316 significantly faster than gdb software watchpoints.
1320 ** The register_pretty_printer function in module gdb.printing now takes
1321 an optional `replace' argument. If True, the new printer replaces any
1324 ** The "maint set python print-stack on|off" command has been
1325 deprecated and will be deleted in GDB 7.5.
1326 A new command: "set python print-stack none|full|message" has
1327 replaced it. Additionally, the default for "print-stack" is
1328 now "message", which just prints the error message without
1331 ** A prompt substitution hook (prompt_hook) is now available to the
1334 ** A new Python module, gdb.prompt has been added to the GDB Python
1335 modules library. This module provides functionality for
1336 escape sequences in prompts (used by set/show
1337 extended-prompt). These escape sequences are replaced by their
1338 corresponding value.
1340 ** Python commands and convenience-functions located in
1341 'data-directory'/python/gdb/command and
1342 'data-directory'/python/gdb/function are now automatically loaded
1345 ** Blocks now provide four new attributes. global_block and
1346 static_block will return the global and static blocks
1347 respectively. is_static and is_global are boolean attributes
1348 that indicate if the block is one of those two types.
1350 ** Symbols now provide the "type" attribute, the type of the symbol.
1352 ** The "gdb.breakpoint" function has been deprecated in favor of
1355 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1356 of a function. This class is based on the "finish" command
1357 available in the CLI.
1359 ** Type objects for struct and union types now allow access to
1360 the fields using standard Python dictionary (mapping) methods.
1361 For example, "some_type['myfield']" now works, as does
1362 "some_type.items()".
1364 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1367 ** A new function, "deep_items" has been added to the gdb.types
1368 module in the GDB Python modules library. This function returns
1369 an iterator over the fields of a struct or union type. Unlike
1370 the standard Python "iteritems" method, it will recursively traverse
1371 any anonymous fields.
1375 ** "*stopped" events can report several new "reason"s, such as
1378 ** Breakpoint changes are now notified using new async records, like
1379 "=breakpoint-modified".
1381 ** New command -ada-task-info.
1383 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1384 $sdir specifies the default system locations of shared libraries.
1385 $pdir specifies the directory where the libpthread used by the application
1388 GDB no longer looks in $sdir and $pdir after it has searched the directories
1389 mentioned in libthread-db-search-path. If you want to search those
1390 directories, they must be specified in libthread-db-search-path.
1391 The default value of libthread-db-search-path on GNU/Linux and Solaris
1392 systems is now "$sdir:$pdir".
1394 $pdir is not supported by gdbserver, it is currently ignored.
1395 $sdir is supported by gdbserver.
1397 * New configure option --with-iconv-bin.
1398 When using the internationalization support like the one in the GNU C
1399 library, GDB will invoke the "iconv" program to get a list of supported
1400 character sets. If this program lives in a non-standard location, one can
1401 use this option to specify where to find it.
1403 * When natively debugging programs on PowerPC BookE processors running
1404 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1405 watchpoints, which specify a mask in addition to an address to watch.
1406 The mask specifies that some bits of an address (the bits which are
1407 reset in the mask) should be ignored when matching the address accessed
1408 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1409 section in the user manual for more details.
1411 * The new option --once causes GDBserver to stop listening for connections once
1412 the first connection is made. The listening port used by GDBserver will
1413 become available after that.
1415 * New commands "info macros" and "alias" have been added.
1417 * New function parameters suffix @entry specifies value of function parameter
1418 at the time the function got called. Entry values are available only since
1424 "!" is now an alias of the "shell" command.
1425 Note that no space is needed between "!" and SHELL COMMAND.
1429 watch EXPRESSION mask MASK_VALUE
1430 The watch command now supports the mask argument which allows creation
1431 of masked watchpoints, if the current architecture supports this feature.
1433 info auto-load-scripts [REGEXP]
1434 This command was formerly named "maintenance print section-scripts".
1435 It is now generally useful and is no longer a maintenance-only command.
1437 info macro [-all] [--] MACRO
1438 The info macro command has new options `-all' and `--'. The first for
1439 printing all definitions of a macro. The second for explicitly specifying
1440 the end of arguments and the beginning of the macro name in case the macro
1441 name starts with a hyphen.
1443 collect[/s] EXPRESSIONS
1444 The tracepoint collect command now takes an optional modifier "/s"
1445 that directs it to dereference pointer-to-character types and
1446 collect the bytes of memory up to a zero byte. The behavior is
1447 similar to what you see when you use the regular print command on a
1448 string. An optional integer following the "/s" sets a bound on the
1449 number of bytes that will be collected.
1452 The trace start command now interprets any supplied arguments as a
1453 note to be recorded with the trace run, with an effect similar to
1454 setting the variable trace-notes.
1457 The trace stop command now interprets any arguments as a note to be
1458 mentioned along with the tstatus report that the trace was stopped
1459 with a command. The effect is similar to setting the variable
1462 * Tracepoints can now be enabled and disabled at any time after a trace
1463 experiment has been started using the standard "enable" and "disable"
1464 commands. It is now possible to start a trace experiment with no enabled
1465 tracepoints; GDB will display a warning, but will allow the experiment to
1466 begin, assuming that tracepoints will be enabled as needed while the trace
1469 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1470 locations with 4-byte instructions, when they were previously
1471 limited to locations with instructions of 5 bytes or longer.
1475 set debug dwarf2-read
1476 show debug dwarf2-read
1477 Turns on or off display of debugging messages related to reading
1478 DWARF debug info. The default is off.
1480 set debug symtab-create
1481 show debug symtab-create
1482 Turns on or off display of debugging messages related to symbol table
1483 creation. The default is off.
1486 show extended-prompt
1487 Set the GDB prompt, and allow escape sequences to be inserted to
1488 display miscellaneous information (see 'help set extended-prompt'
1489 for the list of sequences). This prompt (and any information
1490 accessed through the escape sequences) is updated every time the
1491 prompt is displayed.
1493 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1494 show print entry-values
1495 Set printing of frame argument values at function entry. In some cases
1496 GDB can determine the value of function argument which was passed by the
1497 function caller, even if the value was modified inside the called function.
1499 set debug entry-values
1500 show debug entry-values
1501 Control display of debugging info for determining frame argument values at
1502 function entry and virtual tail call frames.
1504 set basenames-may-differ
1505 show basenames-may-differ
1506 Set whether a source file may have multiple base names.
1507 (A "base name" is the name of a file with the directory part removed.
1508 Example: The base name of "/home/user/hello.c" is "hello.c".)
1509 If set, GDB will canonicalize file names (e.g., expand symlinks)
1510 before comparing them. Canonicalization is an expensive operation,
1511 but it allows the same file be known by more than one base name.
1512 If not set (the default), all source files are assumed to have just
1513 one base name, and gdb will do file name comparisons more efficiently.
1519 Set a user name and notes for the current and any future trace runs.
1520 This is useful for long-running and/or disconnected traces, to
1521 inform others (or yourself) as to who is running the trace, supply
1522 contact information, or otherwise explain what is going on.
1524 set trace-stop-notes
1525 show trace-stop-notes
1526 Set a note attached to the trace run, that is displayed when the
1527 trace has been stopped by a tstop command. This is useful for
1528 instance as an explanation, if you are stopping a trace run that was
1529 started by someone else.
1531 * New remote packets
1535 Dynamically enable a tracepoint in a started trace experiment.
1539 Dynamically disable a tracepoint in a started trace experiment.
1543 Set the user and notes of the trace run.
1547 Query the current status of a tracepoint.
1551 Query the minimum length of instruction at which a fast tracepoint may
1554 * Dcache size (number of lines) and line-size are now runtime-configurable
1555 via "set dcache line" and "set dcache line-size" commands.
1559 Texas Instruments TMS320C6x tic6x-*-*
1563 Renesas RL78 rl78-*-elf
1565 *** Changes in GDB 7.3.1
1567 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1569 *** Changes in GDB 7.3
1571 * GDB has a new command: "thread find [REGEXP]".
1572 It finds the thread id whose name, target id, or thread extra info
1573 matches the given regular expression.
1575 * The "catch syscall" command now works on mips*-linux* targets.
1577 * The -data-disassemble MI command now supports modes 2 and 3 for
1578 dumping the instruction opcodes.
1580 * New command line options
1582 -data-directory DIR Specify DIR as the "data-directory".
1583 This is mostly for testing purposes.
1585 * The "maint set python auto-load on|off" command has been renamed to
1586 "set auto-load-scripts on|off".
1588 * GDB has a new command: "set directories".
1589 It is like the "dir" command except that it replaces the
1590 source path list instead of augmenting it.
1592 * GDB now understands thread names.
1594 On GNU/Linux, "info threads" will display the thread name as set by
1595 prctl or pthread_setname_np.
1597 There is also a new command, "thread name", which can be used to
1598 assign a name internally for GDB to display.
1601 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1602 has been integrated into GDB.
1606 ** The function gdb.Write now accepts an optional keyword 'stream'.
1607 This keyword, when provided, will direct the output to either
1608 stdout, stderr, or GDB's logging output.
1610 ** Parameters can now be be sub-classed in Python, and in particular
1611 you may implement the get_set_doc and get_show_doc functions.
1612 This improves how Parameter set/show documentation is processed
1613 and allows for more dynamic content.
1615 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1616 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1617 have an is_valid method.
1619 ** Breakpoints can now be sub-classed in Python, and in particular
1620 you may implement a 'stop' function that is executed each time
1621 the inferior reaches that breakpoint.
1623 ** New function gdb.lookup_global_symbol looks up a global symbol.
1625 ** GDB values in Python are now callable if the value represents a
1626 function. For example, if 'some_value' represents a function that
1627 takes two integer parameters and returns a value, you can call
1628 that function like so:
1630 result = some_value (10,20)
1632 ** Module gdb.types has been added.
1633 It contains a collection of utilities for working with gdb.Types objects:
1634 get_basic_type, has_field, make_enum_dict.
1636 ** Module gdb.printing has been added.
1637 It contains utilities for writing and registering pretty-printers.
1638 New classes: PrettyPrinter, SubPrettyPrinter,
1639 RegexpCollectionPrettyPrinter.
1640 New function: register_pretty_printer.
1642 ** New commands "info pretty-printers", "enable pretty-printer" and
1643 "disable pretty-printer" have been added.
1645 ** gdb.parameter("directories") is now available.
1647 ** New function gdb.newest_frame returns the newest frame in the
1650 ** The gdb.InferiorThread class has a new "name" attribute. This
1651 holds the thread's name.
1653 ** Python Support for Inferior events.
1654 Python scripts can add observers to be notified of events
1655 occurring in the process being debugged.
1656 The following events are currently supported:
1657 - gdb.events.cont Continue event.
1658 - gdb.events.exited Inferior exited event.
1659 - gdb.events.stop Signal received, and Breakpoint hit events.
1663 ** GDB now puts template parameters in scope when debugging in an
1664 instantiation. For example, if you have:
1666 template<int X> int func (void) { return X; }
1668 then if you step into func<5>, "print X" will show "5". This
1669 feature requires proper debuginfo support from the compiler; it
1670 was added to GCC 4.5.
1672 ** The motion commands "next", "finish", "until", and "advance" now
1673 work better when exceptions are thrown. In particular, GDB will
1674 no longer lose control of the inferior; instead, the GDB will
1675 stop the inferior at the point at which the exception is caught.
1676 This functionality requires a change in the exception handling
1677 code that was introduced in GCC 4.5.
1679 * GDB now follows GCC's rules on accessing volatile objects when
1680 reading or writing target state during expression evaluation.
1681 One notable difference to prior behavior is that "print x = 0"
1682 no longer generates a read of x; the value of the assignment is
1683 now always taken directly from the value being assigned.
1685 * GDB now has some support for using labels in the program's source in
1686 linespecs. For instance, you can use "advance label" to continue
1687 execution to a label.
1689 * GDB now has support for reading and writing a new .gdb_index
1690 section. This section holds a fast index of DWARF debugging
1691 information and can be used to greatly speed up GDB startup and
1692 operation. See the documentation for `save gdb-index' for details.
1694 * The "watch" command now accepts an optional "-location" argument.
1695 When used, this causes GDB to watch the memory referred to by the
1696 expression. Such a watchpoint is never deleted due to it going out
1699 * GDB now supports thread debugging of core dumps on GNU/Linux.
1701 GDB now activates thread debugging using the libthread_db library
1702 when debugging GNU/Linux core dumps, similarly to when debugging
1703 live processes. As a result, when debugging a core dump file, GDB
1704 is now able to display pthread_t ids of threads. For example, "info
1705 threads" shows the same output as when debugging the process when it
1706 was live. In earlier releases, you'd see something like this:
1709 * 1 LWP 6780 main () at main.c:10
1711 While now you see this:
1714 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1716 It is also now possible to inspect TLS variables when debugging core
1719 When debugging a core dump generated on a machine other than the one
1720 used to run GDB, you may need to point GDB at the correct
1721 libthread_db library with the "set libthread-db-search-path"
1722 command. See the user manual for more details on this command.
1724 * When natively debugging programs on PowerPC BookE processors running
1725 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1726 which stop execution of the inferior whenever it executes an instruction
1727 at any address within the specified range. See the "PowerPC Embedded"
1728 section in the user manual for more details.
1730 * New features in the GDB remote stub, GDBserver
1732 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1733 and i686 LynxOS (version 5.x).
1735 ** GDBserver is now supported on Blackfin Linux.
1737 * New native configurations
1739 ia64 HP-UX ia64-*-hpux*
1743 Analog Devices, Inc. Blackfin Processor bfin-*
1745 * Ada task switching is now supported on sparc-elf targets when
1746 debugging a program using the Ravenscar Profile. For more information,
1747 see the "Tasking Support when using the Ravenscar Profile" section
1748 in the GDB user manual.
1750 * Guile support was removed.
1752 * New features in the GNU simulator
1754 ** The --map-info flag lists all known core mappings.
1756 ** CFI flashes may be simulated via the "cfi" device.
1758 *** Changes in GDB 7.2
1760 * Shared library support for remote targets by default
1762 When GDB is configured for a generic, non-OS specific target, like
1763 for example, --target=arm-eabi or one of the many *-*-elf targets,
1764 GDB now queries remote stubs for loaded shared libraries using the
1765 `qXfer:libraries:read' packet. Previously, shared library support
1766 was always disabled for such configurations.
1770 ** Argument Dependent Lookup (ADL)
1772 In C++ ADL lookup directs function search to the namespaces of its
1773 arguments even if the namespace has not been imported.
1783 Here the compiler will search for `foo' in the namespace of 'b'
1784 and find A::foo. GDB now supports this. This construct is commonly
1785 used in the Standard Template Library for operators.
1787 ** Improved User Defined Operator Support
1789 In addition to member operators, GDB now supports lookup of operators
1790 defined in a namespace and imported with a `using' directive, operators
1791 defined in the global scope, operators imported implicitly from an
1792 anonymous namespace, and the ADL operators mentioned in the previous
1794 GDB now also supports proper overload resolution for all the previously
1795 mentioned flavors of operators.
1797 ** static const class members
1799 Printing of static const class members that are initialized in the
1800 class definition has been fixed.
1802 * Windows Thread Information Block access.
1804 On Windows targets, GDB now supports displaying the Windows Thread
1805 Information Block (TIB) structure. This structure is visible either
1806 by using the new command `info w32 thread-information-block' or, by
1807 dereferencing the new convenience variable named `$_tlb', a
1808 thread-specific pointer to the TIB. This feature is also supported
1809 when remote debugging using GDBserver.
1811 * Static tracepoints
1813 Static tracepoints are calls in the user program into a tracing
1814 library. One such library is a port of the LTTng kernel tracer to
1815 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1816 When debugging with GDBserver, GDB now supports combining the GDB
1817 tracepoint machinery with such libraries. For example: the user can
1818 use GDB to probe a static tracepoint marker (a call from the user
1819 program into the tracing library) with the new "strace" command (see
1820 "New commands" below). This creates a "static tracepoint" in the
1821 breakpoint list, that can be manipulated with the same feature set
1822 as fast and regular tracepoints. E.g., collect registers, local and
1823 global variables, collect trace state variables, and define
1824 tracepoint conditions. In addition, the user can collect extra
1825 static tracepoint marker specific data, by collecting the new
1826 $_sdata internal variable. When analyzing the trace buffer, you can
1827 inspect $_sdata like any other variable available to GDB. For more
1828 information, see the "Tracepoints" chapter in GDB user manual. New
1829 remote packets have been defined to support static tracepoints, see
1830 the "New remote packets" section below.
1832 * Better reconstruction of tracepoints after disconnected tracing
1834 GDB will attempt to download the original source form of tracepoint
1835 definitions when starting a trace run, and then will upload these
1836 upon reconnection to the target, resulting in a more accurate
1837 reconstruction of the tracepoints that are in use on the target.
1841 You can now exercise direct control over the ways that GDB can
1842 affect your program. For instance, you can disallow the setting of
1843 breakpoints, so that the program can run continuously (assuming
1844 non-stop mode). In addition, the "observer" variable is available
1845 to switch all of the different controls; in observer mode, GDB
1846 cannot affect the target's behavior at all, which is useful for
1847 tasks like diagnosing live systems in the field.
1849 * The new convenience variable $_thread holds the number of the
1852 * New remote packets
1856 Return the address of the Windows Thread Information Block of a given thread.
1860 In response to several of the tracepoint packets, the target may now
1861 also respond with a number of intermediate `qRelocInsn' request
1862 packets before the final result packet, to have GDB handle
1863 relocating an instruction to execute at a different address. This
1864 is particularly useful for stubs that support fast tracepoints. GDB
1865 reports support for this feature in the qSupported packet.
1869 List static tracepoint markers in the target program.
1873 List static tracepoint markers at a given address in the target
1876 qXfer:statictrace:read
1878 Read the static trace data collected (by a `collect $_sdata'
1879 tracepoint action). The remote stub reports support for this packet
1880 to gdb's qSupported query.
1884 Send the current settings of GDB's permission flags.
1888 Send part of the source (textual) form of a tracepoint definition,
1889 which includes location, conditional, and action list.
1891 * The source command now accepts a -s option to force searching for the
1892 script in the source search path even if the script name specifies
1895 * New features in the GDB remote stub, GDBserver
1897 - GDBserver now support tracepoints (including fast tracepoints, and
1898 static tracepoints). The feature is currently supported by the
1899 i386-linux and amd64-linux builds. See the "Tracepoints support
1900 in gdbserver" section in the manual for more information.
1902 GDBserver JIT compiles the tracepoint's conditional agent
1903 expression bytecode into native code whenever possible for low
1904 overhead dynamic tracepoints conditionals. For such tracepoints,
1905 an expression that examines program state is evaluated when the
1906 tracepoint is reached, in order to determine whether to capture
1907 trace data. If the condition is simple and false, processing the
1908 tracepoint finishes very quickly and no data is gathered.
1910 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1911 for static tracepoints support.
1913 - GDBserver now supports x86_64 Windows 64-bit debugging.
1915 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1916 it understands register description.
1918 * The --batch flag now disables pagination and queries.
1920 * X86 general purpose registers
1922 GDB now supports reading/writing byte, word and double-word x86
1923 general purpose registers directly. This means you can use, say,
1924 $ah or $ax to refer, respectively, to the byte register AH and
1925 16-bit word register AX that are actually portions of the 32-bit
1926 register EAX or 64-bit register RAX.
1928 * The `commands' command now accepts a range of breakpoints to modify.
1929 A plain `commands' following a command that creates multiple
1930 breakpoints affects all the breakpoints set by that command. This
1931 applies to breakpoints set by `rbreak', and also applies when a
1932 single `break' command creates multiple breakpoints (e.g.,
1933 breakpoints on overloaded c++ functions).
1935 * The `rbreak' command now accepts a filename specification as part of
1936 its argument, limiting the functions selected by the regex to those
1937 in the specified file.
1939 * Support for remote debugging Windows and SymbianOS shared libraries
1940 from Unix hosts has been improved. Non Windows GDB builds now can
1941 understand target reported file names that follow MS-DOS based file
1942 system semantics, such as file names that include drive letters and
1943 use the backslash character as directory separator. This makes it
1944 possible to transparently use the "set sysroot" and "set
1945 solib-search-path" on Unix hosts to point as host copies of the
1946 target's shared libraries. See the new command "set
1947 target-file-system-kind" described below, and the "Commands to
1948 specify files" section in the user manual for more information.
1952 eval template, expressions...
1953 Convert the values of one or more expressions under the control
1954 of the string template to a command line, and call it.
1956 set target-file-system-kind unix|dos-based|auto
1957 show target-file-system-kind
1958 Set or show the assumed file system kind for target reported file
1961 save breakpoints <filename>
1962 Save all current breakpoint definitions to a file suitable for use
1963 in a later debugging session. To read the saved breakpoint
1964 definitions, use the `source' command.
1966 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1969 info static-tracepoint-markers
1970 Display information about static tracepoint markers in the target.
1972 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1973 Define a static tracepoint by probing a marker at the given
1974 function, line, address, or marker ID.
1978 Enable and disable observer mode.
1980 set may-write-registers on|off
1981 set may-write-memory on|off
1982 set may-insert-breakpoints on|off
1983 set may-insert-tracepoints on|off
1984 set may-insert-fast-tracepoints on|off
1985 set may-interrupt on|off
1986 Set individual permissions for GDB effects on the target. Note that
1987 some of these settings can have undesirable or surprising
1988 consequences, particularly when changed in the middle of a session.
1989 For instance, disabling the writing of memory can prevent
1990 breakpoints from being inserted, cause single-stepping to fail, or
1991 even crash your program, if you disable after breakpoints have been
1992 inserted. However, GDB should not crash.
1994 set record memory-query on|off
1995 show record memory-query
1996 Control whether to stop the inferior if memory changes caused
1997 by an instruction cannot be recorded.
2002 The disassemble command now supports "start,+length" form of two arguments.
2006 ** GDB now provides a new directory location, called the python directory,
2007 where Python scripts written for GDB can be installed. The location
2008 of that directory is <data-directory>/python, where <data-directory>
2009 is the GDB data directory. For more details, see section `Scripting
2010 GDB using Python' in the manual.
2012 ** The GDB Python API now has access to breakpoints, symbols, symbol
2013 tables, program spaces, inferiors, threads and frame's code blocks.
2014 Additionally, GDB Parameters can now be created from the API, and
2015 manipulated via set/show in the CLI.
2017 ** New functions gdb.target_charset, gdb.target_wide_charset,
2018 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2020 ** New exception gdb.GdbError.
2022 ** Pretty-printers are now also looked up in the current program space.
2024 ** Pretty-printers can now be individually enabled and disabled.
2026 ** GDB now looks for names of Python scripts to auto-load in a
2027 special section named `.debug_gdb_scripts', in addition to looking
2028 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2030 * Tracepoint actions were unified with breakpoint commands. In particular,
2031 there are no longer differences in "info break" output for breakpoints and
2032 tracepoints and the "commands" command can be used for both tracepoints and
2033 regular breakpoints.
2037 ARM Symbian arm*-*-symbianelf*
2039 * D language support.
2040 GDB now supports debugging programs written in the D programming
2043 * GDB now supports the extended ptrace interface for PowerPC which is
2044 available since Linux kernel version 2.6.34. This automatically enables
2045 any hardware breakpoints and additional hardware watchpoints available in
2046 the processor. The old ptrace interface exposes just one hardware
2047 watchpoint and no hardware breakpoints.
2049 * GDB is now able to use the Data Value Compare (DVC) register available on
2050 embedded PowerPC processors to implement in hardware simple watchpoint
2051 conditions of the form:
2053 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2055 This works in native GDB running on Linux kernels with the extended ptrace
2056 interface mentioned above.
2058 *** Changes in GDB 7.1
2062 ** Namespace Support
2064 GDB now supports importing of namespaces in C++. This enables the
2065 user to inspect variables from imported namespaces. Support for
2066 namepace aliasing has also been added. So, if a namespace is
2067 aliased in the current scope (e.g. namepace C=A; ) the user can
2068 print variables using the alias (e.g. (gdb) print C::x).
2072 All known bugs relating to the printing of virtual base class were
2073 fixed. It is now possible to call overloaded static methods using a
2078 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2079 and reinterpret_cast<> are now handled by the C++ expression parser.
2083 Xilinx MicroBlaze microblaze-*-*
2088 Xilinx MicroBlaze microblaze
2091 * Multi-program debugging.
2093 GDB now has support for multi-program (a.k.a. multi-executable or
2094 multi-exec) debugging. This allows for debugging multiple inferiors
2095 simultaneously each running a different program under the same GDB
2096 session. See "Debugging Multiple Inferiors and Programs" in the
2097 manual for more information. This implied some user visible changes
2098 in the multi-inferior support. For example, "info inferiors" now
2099 lists inferiors that are not running yet or that have exited
2100 already. See also "New commands" and "New options" below.
2102 * New tracing features
2104 GDB's tracepoint facility now includes several new features:
2106 ** Trace state variables
2108 GDB tracepoints now include support for trace state variables, which
2109 are variables managed by the target agent during a tracing
2110 experiment. They are useful for tracepoints that trigger each
2111 other, so for instance one tracepoint can count hits in a variable,
2112 and then a second tracepoint has a condition that is true when the
2113 count reaches a particular value. Trace state variables share the
2114 $-syntax of GDB convenience variables, and can appear in both
2115 tracepoint actions and condition expressions. Use the "tvariable"
2116 command to create, and "info tvariables" to view; see "Trace State
2117 Variables" in the manual for more detail.
2121 GDB now includes an option for defining fast tracepoints, which
2122 targets may implement more efficiently, such as by installing a jump
2123 into the target agent rather than a trap instruction. The resulting
2124 speedup can be by two orders of magnitude or more, although the
2125 tradeoff is that some program locations on some target architectures
2126 might not allow fast tracepoint installation, for instance if the
2127 instruction to be replaced is shorter than the jump. To request a
2128 fast tracepoint, use the "ftrace" command, with syntax identical to
2129 the regular trace command.
2131 ** Disconnected tracing
2133 It is now possible to detach GDB from the target while it is running
2134 a trace experiment, then reconnect later to see how the experiment
2135 is going. In addition, a new variable disconnected-tracing lets you
2136 tell the target agent whether to continue running a trace if the
2137 connection is lost unexpectedly.
2141 GDB now has the ability to save the trace buffer into a file, and
2142 then use that file as a target, similarly to you can do with
2143 corefiles. You can select trace frames, print data that was
2144 collected in them, and use tstatus to display the state of the
2145 tracing run at the moment that it was saved. To create a trace
2146 file, use "tsave <filename>", and to use it, do "target tfile
2149 ** Circular trace buffer
2151 You can ask the target agent to handle the trace buffer as a
2152 circular buffer, discarding the oldest trace frames to make room for
2153 newer ones, by setting circular-trace-buffer to on. This feature may
2154 not be available for all target agents.
2159 The disassemble command, when invoked with two arguments, now requires
2160 the arguments to be comma-separated.
2163 The info variables command now displays variable definitions. Files
2164 which only declare a variable are not shown.
2167 The source command is now capable of sourcing Python scripts.
2168 This feature is dependent on the debugger being build with Python
2171 Related to this enhancement is also the introduction of a new command
2172 "set script-extension" (see below).
2174 * New commands (for set/show, see "New options" below)
2176 record save [<FILENAME>]
2177 Save a file (in core file format) containing the process record
2178 execution log for replay debugging at a later time.
2180 record restore <FILENAME>
2181 Restore the process record execution log that was saved at an
2182 earlier time, for replay debugging.
2184 add-inferior [-copies <N>] [-exec <FILENAME>]
2187 clone-inferior [-copies <N>] [ID]
2188 Make a new inferior ready to execute the same program another
2189 inferior has loaded.
2194 maint info program-spaces
2195 List the program spaces loaded into GDB.
2197 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2198 show remote interrupt-sequence
2199 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2200 as the sequence to the remote target in order to interrupt the execution.
2201 Ctrl-C is a default. Some system prefers BREAK which is high level of
2202 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2203 Magic SysRq g. It is BREAK signal and character 'g'.
2205 set remote interrupt-on-connect [on | off]
2206 show remote interrupt-on-connect
2207 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2208 remote target when gdb connects to it. This is needed when you debug
2211 set remotebreak [on | off]
2213 Deprecated. Use "set/show remote interrupt-sequence" instead.
2215 tvariable $NAME [ = EXP ]
2216 Create or modify a trace state variable.
2219 List trace state variables and their values.
2221 delete tvariable $NAME ...
2222 Delete one or more trace state variables.
2225 Evaluate the given expressions without collecting anything into the
2226 trace buffer. (Valid in tracepoint actions only.)
2228 ftrace FN / FILE:LINE / *ADDR
2229 Define a fast tracepoint at the given function, line, or address.
2231 * New expression syntax
2233 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2234 GDB now parses 0b101010 identically with 42.
2238 set follow-exec-mode new|same
2239 show follow-exec-mode
2240 Control whether GDB reuses the same inferior across an exec call or
2241 creates a new one. This is useful to be able to restart the old
2242 executable after the inferior having done an exec call.
2244 set default-collect EXPR, ...
2245 show default-collect
2246 Define a list of expressions to be collected at each tracepoint.
2247 This is a useful way to ensure essential items are not overlooked,
2248 such as registers or a critical global variable.
2250 set disconnected-tracing
2251 show disconnected-tracing
2252 If set to 1, the target is instructed to continue tracing if it
2253 loses its connection to GDB. If 0, the target is to stop tracing
2256 set circular-trace-buffer
2257 show circular-trace-buffer
2258 If set to on, the target is instructed to use a circular trace buffer
2259 and discard the oldest trace frames instead of stopping the trace due
2260 to a full trace buffer. If set to off, the trace stops when the buffer
2261 fills up. Some targets may not support this.
2263 set script-extension off|soft|strict
2264 show script-extension
2265 If set to "off", the debugger does not perform any script language
2266 recognition, and all sourced files are assumed to be GDB scripts.
2267 If set to "soft" (the default), files are sourced according to
2268 filename extension, falling back to GDB scripts if the first
2270 If set to "strict", files are sourced according to filename extension.
2272 set ada trust-PAD-over-XVS on|off
2273 show ada trust-PAD-over-XVS
2274 If off, activate a workaround against a bug in the debugging information
2275 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2276 the GCC sources for more information about the GNAT encoding and
2277 PAD types in particular). It is always safe to set this option to
2278 off, but this introduces a slight performance penalty. The default
2281 * Python API Improvements
2283 ** GDB provides the new class gdb.LazyString. This is useful in
2284 some pretty-printing cases. The new method gdb.Value.lazy_string
2285 provides a simple way to create objects of this type.
2287 ** The fields returned by gdb.Type.fields now have an
2288 `is_base_class' attribute.
2290 ** The new method gdb.Type.range returns the range of an array type.
2292 ** The new method gdb.parse_and_eval can be used to parse and
2293 evaluate an expression.
2295 * New remote packets
2298 Define a trace state variable.
2301 Get the current value of a trace state variable.
2304 Set desired tracing behavior upon disconnection.
2307 Set the trace buffer to be linear or circular.
2310 Get data about the tracepoints currently in use.
2314 Process record now works correctly with hardware watchpoints.
2316 Multiple bug fixes have been made to the mips-irix port, making it
2317 much more reliable. In particular:
2318 - Debugging threaded applications is now possible again. Previously,
2319 GDB would hang while starting the program, or while waiting for
2320 the program to stop at a breakpoint.
2321 - Attaching to a running process no longer hangs.
2322 - An error occurring while loading a core file has been fixed.
2323 - Changing the value of the PC register now works again. This fixes
2324 problems observed when using the "jump" command, or when calling
2325 a function from GDB, or even when assigning a new value to $pc.
2326 - With the "finish" and "return" commands, the return value for functions
2327 returning a small array is now correctly printed.
2328 - It is now possible to break on shared library code which gets executed
2329 during a shared library init phase (code executed while executing
2330 their .init section). Previously, the breakpoint would have no effect.
2331 - GDB is now able to backtrace through the signal handler for
2332 non-threaded programs.
2334 PIE (Position Independent Executable) programs debugging is now supported.
2335 This includes debugging execution of PIC (Position Independent Code) shared
2336 libraries although for that, it should be possible to run such libraries as an
2339 *** Changes in GDB 7.0
2341 * GDB now has an interface for JIT compilation. Applications that
2342 dynamically generate code can create symbol files in memory and register
2343 them with GDB. For users, the feature should work transparently, and
2344 for JIT developers, the interface is documented in the GDB manual in the
2345 "JIT Compilation Interface" chapter.
2347 * Tracepoints may now be conditional. The syntax is as for
2348 breakpoints; either an "if" clause appended to the "trace" command,
2349 or the "condition" command is available. GDB sends the condition to
2350 the target for evaluation using the same bytecode format as is used
2351 for tracepoint actions.
2353 * The disassemble command now supports: an optional /r modifier, print the
2354 raw instructions in hex as well as in symbolic form, and an optional /m
2355 modifier to print mixed source+assembly.
2357 * Process record and replay
2359 In a architecture environment that supports ``process record and
2360 replay'', ``process record and replay'' target can record a log of
2361 the process execution, and replay it with both forward and reverse
2364 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2365 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2366 set execution-direction {forward|reverse}, for targets that support
2369 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2370 feature is available with a native GDB running on kernel version
2373 * GDB now has support for multi-byte and wide character sets on the
2374 target. Strings whose character type is wchar_t, char16_t, or
2375 char32_t are now correctly printed. GDB supports wide- and unicode-
2376 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2377 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2378 `printf'. This feature requires iconv to work properly; if your
2379 system does not have a working iconv, GDB can use GNU libiconv. See
2380 the installation instructions for more information.
2382 * GDB now supports automatic retrieval of shared library files from
2383 remote targets. To use this feature, specify a system root that begins
2384 with the `remote:' prefix, either via the `set sysroot' command or via
2385 the `--with-sysroot' configure-time option.
2387 * "info sharedlibrary" now takes an optional regex of libraries to show,
2388 and it now reports if a shared library has no debugging information.
2390 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2391 now complete on file names.
2393 * When completing in expressions, gdb will attempt to limit
2394 completions to allowable structure or union fields, where appropriate.
2395 For instance, consider:
2397 # struct example { int f1; double f2; };
2398 # struct example variable;
2401 If the user types TAB at the end of this command line, the available
2402 completions will be "f1" and "f2".
2404 * Inlined functions are now supported. They show up in backtraces, and
2405 the "step", "next", and "finish" commands handle them automatically.
2407 * GDB now supports the token-splicing (##) and stringification (#)
2408 operators when expanding macros. It also supports variable-arity
2411 * GDB now supports inspecting extra signal information, exported by
2412 the new $_siginfo convenience variable. The feature is currently
2413 implemented on linux ARM, i386 and amd64.
2415 * GDB can now display the VFP floating point registers and NEON vector
2416 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2417 can provide these registers (requires Linux 2.6.30 or later). Remote
2418 and simulator targets may also provide them.
2420 * New remote packets
2423 Search memory for a sequence of bytes.
2426 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2427 operation over reliable transport links. Use of this packet is
2428 controlled by the `set remote noack-packet' command.
2431 Kill the process with the specified process ID. Use this in preference
2432 to `k' when multiprocess protocol extensions are supported.
2435 Obtains additional operating system information
2439 Read or write additional signal information.
2441 * Removed remote protocol undocumented extension
2443 An undocumented extension to the remote protocol's `S' stop reply
2444 packet that permited the stub to pass a process id was removed.
2445 Remote servers should use the `T' stop reply packet instead.
2447 * GDB now supports multiple function calling conventions according to the
2448 DWARF-2 DW_AT_calling_convention function attribute.
2450 * The SH target utilizes the aforementioned change to distinguish between gcc
2451 and Renesas calling convention. It also adds the new CLI commands
2452 `set/show sh calling-convention'.
2454 * GDB can now read compressed debug sections, as produced by GNU gold
2455 with the --compress-debug-sections=zlib flag.
2457 * 64-bit core files are now supported on AIX.
2459 * Thread switching is now supported on Tru64.
2461 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2462 which will be allocated using malloc later in program execution.
2464 * The qXfer:libraries:read remote procotol packet now allows passing a
2465 list of section offsets.
2467 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2468 conditions handling signals delivered during attach or thread creation
2469 have also been fixed.
2471 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2472 From the user's standpoint, all unqualified instances of True and False
2473 are treated as the standard definitions, regardless of context.
2475 * GDB now parses C++ symbol and type names more flexibly. For
2478 template<typename T> class C { };
2481 GDB will now correctly handle all of:
2483 ptype C<char const *>
2484 ptype C<char const*>
2485 ptype C<const char *>
2486 ptype C<const char*>
2488 * New features in the GDB remote stub, gdbserver
2490 - The "--wrapper" command-line argument tells gdbserver to use a
2491 wrapper program to launch programs for debugging.
2493 - On PowerPC and S/390 targets, it is now possible to use a single
2494 gdbserver executable to debug both 32-bit and 64-bit programs.
2495 (This requires gdbserver itself to be built as a 64-bit executable.)
2497 - gdbserver uses the new noack protocol mode for TCP connections to
2498 reduce communications latency, if also supported and enabled in GDB.
2500 - Support for the sparc64-linux-gnu target is now included in
2503 - The amd64-linux build of gdbserver now supports debugging both
2504 32-bit and 64-bit programs.
2506 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2507 now support hardware watchpoints, and will use them automatically
2512 GDB now has support for scripting using Python. Whether this is
2513 available is determined at configure time.
2515 New GDB commands can now be written in Python.
2517 * Ada tasking support
2519 Ada tasks can now be inspected in GDB. The following commands have
2523 Print the list of Ada tasks.
2525 Print detailed information about task number N.
2527 Print the task number of the current task.
2529 Switch the context of debugging to task number N.
2531 * Support for user-defined prefixed commands. The "define" command can
2532 add new commands to existing prefixes, e.g. "target".
2534 * Multi-inferior, multi-process debugging.
2536 GDB now has generalized support for multi-inferior debugging. See
2537 "Debugging Multiple Inferiors" in the manual for more information.
2538 Although availability still depends on target support, the command
2539 set is more uniform now. The GNU/Linux specific multi-forks support
2540 has been migrated to this new framework. This implied some user
2541 visible changes; see "New commands" and also "Removed commands"
2544 * Target descriptions can now describe the target OS ABI. See the
2545 "Target Description Format" section in the user manual for more
2548 * Target descriptions can now describe "compatible" architectures
2549 to indicate that the target can execute applications for a different
2550 architecture in addition to those for the main target architecture.
2551 See the "Target Description Format" section in the user manual for
2554 * Multi-architecture debugging.
2556 GDB now includes general supports for debugging applications on
2557 hybrid systems that use more than one single processor architecture
2558 at the same time. Each such hybrid architecture still requires
2559 specific support to be added. The only hybrid architecture supported
2560 in this version of GDB is the Cell Broadband Engine.
2562 * GDB now supports integrated debugging of Cell/B.E. applications that
2563 use both the PPU and SPU architectures. To enable support for hybrid
2564 Cell/B.E. debugging, you need to configure GDB to support both the
2565 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2566 --enable-targets configure option.
2568 * Non-stop mode debugging.
2570 For some targets, GDB now supports an optional mode of operation in
2571 which you can examine stopped threads while other threads continue
2572 to execute freely. This is referred to as non-stop mode, with the
2573 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2574 section in the user manual for more information.
2576 To be able to support remote non-stop debugging, a remote stub needs
2577 to implement the non-stop mode remote protocol extensions, as
2578 described in the "Remote Non-Stop" section of the user manual. The
2579 GDB remote stub, gdbserver, has been adjusted to support these
2580 extensions on linux targets.
2582 * New commands (for set/show, see "New options" below)
2584 catch syscall [NAME(S) | NUMBER(S)]
2585 Catch system calls. Arguments, which should be names of system
2586 calls or their numbers, mean catch only those syscalls. Without
2587 arguments, every syscall will be caught. When the inferior issues
2588 any of the specified syscalls, GDB will stop and announce the system
2589 call, both when it is called and when its call returns. This
2590 feature is currently available with a native GDB running on the
2591 Linux Kernel, under the following architectures: x86, x86_64,
2592 PowerPC and PowerPC64.
2594 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2596 Search memory for a sequence of bytes.
2598 maint set python print-stack
2599 maint show python print-stack
2600 Show a stack trace when an error is encountered in a Python script.
2603 Invoke CODE by passing it to the Python interpreter.
2608 These allow macros to be defined, undefined, and listed
2612 Show operating system information about processes.
2615 List the inferiors currently under GDB's control.
2618 Switch focus to inferior number NUM.
2621 Detach from inferior number NUM.
2624 Kill inferior number NUM.
2628 set spu stop-on-load
2629 show spu stop-on-load
2630 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2632 set spu auto-flush-cache
2633 show spu auto-flush-cache
2634 Control whether to automatically flush the software-managed cache
2635 during Cell/B.E. debugging.
2637 set sh calling-convention
2638 show sh calling-convention
2639 Control the calling convention used when calling SH target functions.
2642 show debug timestamp
2643 Control display of timestamps with GDB debugging output.
2645 set disassemble-next-line
2646 show disassemble-next-line
2647 Control display of disassembled source lines or instructions when
2650 set remote noack-packet
2651 show remote noack-packet
2652 Set/show the use of remote protocol QStartNoAckMode packet. See above
2653 under "New remote packets."
2655 set remote query-attached-packet
2656 show remote query-attached-packet
2657 Control use of remote protocol `qAttached' (query-attached) packet.
2659 set remote read-siginfo-object
2660 show remote read-siginfo-object
2661 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2664 set remote write-siginfo-object
2665 show remote write-siginfo-object
2666 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2669 set remote reverse-continue
2670 show remote reverse-continue
2671 Control use of remote protocol 'bc' (reverse-continue) packet.
2673 set remote reverse-step
2674 show remote reverse-step
2675 Control use of remote protocol 'bs' (reverse-step) packet.
2677 set displaced-stepping
2678 show displaced-stepping
2679 Control displaced stepping mode. Displaced stepping is a way to
2680 single-step over breakpoints without removing them from the debuggee.
2681 Also known as "out-of-line single-stepping".
2684 show debug displaced
2685 Control display of debugging info for displaced stepping.
2687 maint set internal-error
2688 maint show internal-error
2689 Control what GDB does when an internal error is detected.
2691 maint set internal-warning
2692 maint show internal-warning
2693 Control what GDB does when an internal warning is detected.
2698 Use a wrapper program to launch programs for debugging.
2700 set multiple-symbols (all|ask|cancel)
2701 show multiple-symbols
2702 The value of this variable can be changed to adjust the debugger behavior
2703 when an expression or a breakpoint location contains an ambiguous symbol
2704 name (an overloaded function name, for instance).
2706 set breakpoint always-inserted
2707 show breakpoint always-inserted
2708 Keep breakpoints always inserted in the target, as opposed to inserting
2709 them when resuming the target, and removing them when the target stops.
2710 This option can improve debugger performance on slow remote targets.
2712 set arm fallback-mode (arm|thumb|auto)
2713 show arm fallback-mode
2714 set arm force-mode (arm|thumb|auto)
2716 These commands control how ARM GDB determines whether instructions
2717 are ARM or Thumb. The default for both settings is auto, which uses
2718 the current CPSR value for instructions without symbols; previous
2719 versions of GDB behaved as if "set arm fallback-mode arm".
2721 set disable-randomization
2722 show disable-randomization
2723 Standalone programs run with the virtual address space randomization enabled
2724 by default on some platforms. This option keeps the addresses stable across
2725 multiple debugging sessions.
2729 Control whether other threads are stopped or not when some thread hits
2734 Requests that asynchronous execution is enabled in the target, if available.
2735 In this case, it's possible to resume target in the background, and interact
2736 with GDB while the target is running. "show target-async" displays the
2737 current state of asynchronous execution of the target.
2739 set target-wide-charset
2740 show target-wide-charset
2741 The target-wide-charset is the name of the character set that GDB
2742 uses when printing characters whose type is wchar_t.
2744 set tcp auto-retry (on|off)
2746 set tcp connect-timeout
2747 show tcp connect-timeout
2748 These commands allow GDB to retry failed TCP connections to a remote stub
2749 with a specified timeout period; this is useful if the stub is launched
2750 in parallel with GDB but may not be ready to accept connections immediately.
2752 set libthread-db-search-path
2753 show libthread-db-search-path
2754 Control list of directories which GDB will search for appropriate
2757 set schedule-multiple (on|off)
2758 show schedule-multiple
2759 Allow GDB to resume all threads of all processes or only threads of
2760 the current process.
2764 Use more aggressive caching for accesses to the stack. This improves
2765 performance of remote debugging (particularly backtraces) without
2766 affecting correctness.
2768 set interactive-mode (on|off|auto)
2769 show interactive-mode
2770 Control whether GDB runs in interactive mode (on) or not (off).
2771 When in interactive mode, GDB waits for the user to answer all
2772 queries. Otherwise, GDB does not wait and assumes the default
2773 answer. When set to auto (the default), GDB determines which
2774 mode to use based on the stdin settings.
2779 For program forks, this is replaced by the new more generic `info
2780 inferiors' command. To list checkpoints, you can still use the
2781 `info checkpoints' command, which was an alias for the `info forks'
2785 Replaced by the new `inferior' command. To switch between
2786 checkpoints, you can still use the `restart' command, which was an
2787 alias for the `fork' command.
2790 This is removed, since some targets don't have a notion of
2791 processes. To switch between processes, you can still use the
2792 `inferior' command using GDB's own inferior number.
2795 For program forks, this is replaced by the new more generic `kill
2796 inferior' command. To delete a checkpoint, you can still use the
2797 `delete checkpoint' command, which was an alias for the `delete
2801 For program forks, this is replaced by the new more generic `detach
2802 inferior' command. To detach a checkpoint, you can still use the
2803 `detach checkpoint' command, which was an alias for the `detach
2806 * New native configurations
2808 x86/x86_64 Darwin i[34567]86-*-darwin*
2810 x86_64 MinGW x86_64-*-mingw*
2814 Lattice Mico32 lm32-*
2815 x86 DICOS i[34567]86-*-dicos*
2816 x86_64 DICOS x86_64-*-dicos*
2819 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2820 (mingw32ce) debugging.
2826 These commands were actually not implemented on any target.
2828 *** Changes in GDB 6.8
2830 * New native configurations
2832 NetBSD/hppa hppa*-*netbsd*
2833 Xtensa GNU/Linux xtensa*-*-linux*
2837 NetBSD/hppa hppa*-*-netbsd*
2838 Xtensa GNU/Lunux xtensa*-*-linux*
2840 * Change in command line behavior -- corefiles vs. process ids.
2842 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2843 attaching to process NUMBER fails, GDB no longer attempts to open a
2844 core file named NUMBER. Attaching to a program using the -c option
2845 is no longer supported. Instead, use the '-p' or '--pid' options.
2847 * GDB can now be built as a native debugger for debugging Windows x86
2848 (mingw32) Portable Executable (PE) programs.
2850 * Pending breakpoints no longer change their number when their address
2853 * GDB now supports breakpoints with multiple locations,
2854 including breakpoints on C++ constructors, inside C++ templates,
2855 and in inlined functions.
2857 * GDB's ability to debug optimized code has been improved. GDB more
2858 accurately identifies function bodies and lexical blocks that occupy
2859 more than one contiguous range of addresses.
2861 * Target descriptions can now describe registers for PowerPC.
2863 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2864 registers on PowerPC targets.
2866 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2867 targets even when the libthread_db library is not available.
2869 * The GDB remote stub, gdbserver, now supports the new file transfer
2870 commands (remote put, remote get, and remote delete).
2872 * The GDB remote stub, gdbserver, now supports run and attach in
2873 extended-remote mode.
2875 * hppa*64*-*-hpux11* target broken
2876 The debugger is unable to start a program and fails with the following
2877 error: "Error trying to get information about dynamic linker".
2878 The gdb-6.7 release is also affected.
2880 * GDB now supports the --enable-targets= configure option to allow
2881 building a single GDB executable that supports multiple remote
2882 target architectures.
2884 * GDB now supports debugging C and C++ programs which use the
2885 Decimal Floating Point extension. In addition, the PowerPC target
2886 now has a set of pseudo-registers to inspect decimal float values
2887 stored in two consecutive float registers.
2889 * The -break-insert MI command can optionally create pending
2892 * Improved support for debugging Ada
2893 Many improvements to the Ada language support have been made. These
2895 - Better support for Ada2005 interface types
2896 - Improved handling of arrays and slices in general
2897 - Better support for Taft-amendment types
2898 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2900 - Improved command completion in Ada
2903 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2908 set print frame-arguments (all|scalars|none)
2909 show print frame-arguments
2910 The value of this variable can be changed to control which argument
2911 values should be printed by the debugger when displaying a frame.
2916 Transfer files to and from a remote target, and delete remote files.
2923 Transfer files to and from a remote target, and delete remote files.
2925 * New remote packets
2932 Open, close, read, write, and delete files on the remote system.
2935 Attach to an existing process on the remote system, in extended-remote
2939 Run a new process on the remote system, in extended-remote mode.
2941 *** Changes in GDB 6.7
2943 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2944 bfd, libiberty and opcodes, as revealed by static analysis donated by
2945 Coverity, Inc. (http://scan.coverity.com).
2947 * When looking up multiply-defined global symbols, GDB will now prefer the
2948 symbol definition in the current shared library if it was built using the
2949 -Bsymbolic linker option.
2951 * When the Text User Interface (TUI) is not configured, GDB will now
2952 recognize the -tui command-line option and print a message that the TUI
2955 * The GDB remote stub, gdbserver, now has lower overhead for high
2956 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2958 * GDB for MIPS targets now autodetects whether a remote target provides
2959 32-bit or 64-bit register values.
2961 * Support for C++ member pointers has been improved.
2963 * GDB now understands XML target descriptions, which specify the
2964 target's overall architecture. GDB can read a description from
2965 a local file or over the remote serial protocol.
2967 * Vectors of single-byte data use a new integer type which is not
2968 automatically displayed as character or string data.
2970 * The /s format now works with the print command. It displays
2971 arrays of single-byte integers and pointers to single-byte integers
2974 * Target descriptions can now describe target-specific registers,
2975 for architectures which have implemented the support (currently
2976 only ARM, M68K, and MIPS).
2978 * GDB and the GDB remote stub, gdbserver, now support the XScale
2981 * The GDB remote stub, gdbserver, has been updated to support
2982 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2983 has been rewritten to use the standard GDB remote protocol.
2985 * GDB can now step into C++ functions which are called through thunks.
2987 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2989 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2990 layout. It also supports a TextSeg= and DataSeg= response when only
2991 segment base addresses (rather than offsets) are available.
2993 * The /i format now outputs any trailing branch delay slot instructions
2994 immediately following the last instruction within the count specified.
2996 * The GDB remote protocol "T" stop reply packet now supports a
2997 "library" response. Combined with the new "qXfer:libraries:read"
2998 packet, this response allows GDB to debug shared libraries on targets
2999 where the operating system manages the list of loaded libraries (e.g.
3000 Windows and SymbianOS).
3002 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3003 (DLLs) on Windows and Windows CE targets.
3005 * GDB now supports a faster verification that a .debug file matches its binary
3006 according to its build-id signature, if the signature is present.
3012 Enable or disable hardware flow control (RTS/CTS) on the serial port
3013 when debugging using remote targets.
3015 set mem inaccessible-by-default
3016 show mem inaccessible-by-default
3017 If the target supplies a memory map, for instance via the remote
3018 protocol's "qXfer:memory-map:read" packet, setting this variable
3019 prevents GDB from accessing memory outside the memory map. This
3020 is useful for targets with memory mapped registers or which react
3021 badly to accesses of unmapped address space.
3023 set breakpoint auto-hw
3024 show breakpoint auto-hw
3025 If the target supplies a memory map, for instance via the remote
3026 protocol's "qXfer:memory-map:read" packet, setting this variable
3027 lets GDB use hardware breakpoints automatically for memory regions
3028 where it can not use software breakpoints. This covers both the
3029 "break" command and internal breakpoints used for other commands
3030 including "next" and "finish".
3033 catch exception unhandled
3034 Stop the program execution when Ada exceptions are raised.
3037 Stop the program execution when an Ada assertion failed.
3041 Set an alternate system root for target files. This is a more
3042 general version of "set solib-absolute-prefix", which is now
3043 an alias to "set sysroot".
3046 Provide extended SPU facility status information. This set of
3047 commands is available only when debugging the Cell/B.E. SPU
3050 * New native configurations
3052 OpenBSD/sh sh*-*openbsd*
3055 unset tdesc filename
3057 Use the specified local file as an XML target description, and do
3058 not query the target for its built-in description.
3062 OpenBSD/sh sh*-*-openbsd*
3063 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3064 Toshiba Media Processor mep-elf
3066 * New remote packets
3069 Ignore the specified signals; pass them directly to the debugged program
3070 without stopping other threads or reporting them to GDB.
3072 qXfer:features:read:
3073 Read an XML target description from the target, which describes its
3078 Read or write contents of an spufs file on the target system. These
3079 packets are available only on the Cell/B.E. SPU architecture.
3081 qXfer:libraries:read:
3082 Report the loaded shared libraries. Combined with new "T" packet
3083 response, this packet allows GDB to debug shared libraries on
3084 targets where the operating system manages the list of loaded
3085 libraries (e.g. Windows and SymbianOS).
3089 Support for these obsolete configurations has been removed.
3097 i[34567]86-*-lynxos*
3098 i[34567]86-*-netware*
3099 i[34567]86-*-sco3.2v5*
3100 i[34567]86-*-sco3.2v4*
3102 i[34567]86-*-sysv4.2*
3105 i[34567]86-*-unixware2*
3106 i[34567]86-*-unixware*
3115 * Other removed features
3122 Various m68k-only ROM monitors.
3129 Various Renesas ROM monitors and debugging interfaces for SH and
3134 Support for a Macraigor serial interface to on-chip debugging.
3135 GDB does not directly support the newer parallel or USB
3140 A debug information format. The predecessor to DWARF 2 and
3141 DWARF 3, which are still supported.
3143 Support for the HP aCC compiler on HP-UX/PA-RISC
3145 SOM-encapsulated symbolic debugging information, automatic
3146 invocation of pxdb, and the aCC custom C++ ABI. This does not
3147 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3148 with aCC can still be debugged on an assembly level.
3150 MIPS ".pdr" sections
3152 A MIPS-specific format used to describe stack frame layout
3153 in debugging information.
3157 GDB could work with an older version of Guile to debug
3158 the interpreter and Scheme programs running in it.
3160 set mips stack-arg-size
3161 set mips saved-gpreg-size
3163 Use "set mips abi" to control parameter passing for MIPS.
3165 *** Changes in GDB 6.6
3170 Cell Broadband Engine SPU spu-elf
3172 * GDB can now be configured as a cross-debugger targeting native Windows
3173 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3174 running on a Windows system over TCP/IP to debug Windows programs.
3176 * The GDB remote stub, gdbserver, has been updated to support Windows and
3177 Cygwin debugging. Both single-threaded and multi-threaded programs are
3180 * The "set trust-readonly-sections" command works again. This command was
3181 broken in GDB 6.3, 6.4, and 6.5.
3183 * The "load" command now supports writing to flash memory, if the remote
3184 stub provides the required support.
3186 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3187 longer requires symbolic debug information (e.g. DWARF-2).
3192 unset substitute-path
3193 show substitute-path
3194 Manage a list of substitution rules that GDB uses to rewrite the name
3195 of the directories where the sources are located. This can be useful
3196 for instance when the sources were moved to a different location
3197 between compilation and debugging.
3201 Print each CLI command as it is executed. Each command is prefixed with
3202 a number of `+' symbols representing the nesting depth.
3203 The source command now has a `-v' option to enable the same feature.
3207 The ARM Demon monitor support (RDP protocol, "target rdp").
3209 Kernel Object Display, an embedded debugging feature which only worked with
3210 an obsolete version of Cisco IOS.
3212 The 'set download-write-size' and 'show download-write-size' commands.
3214 * New remote packets
3217 Tell a stub about GDB client features, and request remote target features.
3218 The first feature implemented is PacketSize, which allows the target to
3219 specify the size of packets it can handle - to minimize the number of
3220 packets required and improve performance when connected to a remote
3224 Fetch an OS auxilliary vector from the remote stub. This packet is a
3225 more efficient replacement for qPart:auxv:read.
3227 qXfer:memory-map:read:
3228 Fetch a memory map from the remote stub, including information about
3229 RAM, ROM, and flash memory devices.
3234 Erase and program a flash memory device.
3236 * Removed remote packets
3239 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3240 used it, and only gdbserver implemented it.
3242 *** Changes in GDB 6.5
3246 Renesas M32C/M16C m32c-elf
3248 Morpho Technologies ms1 ms1-elf
3252 init-if-undefined Initialize a convenience variable, but
3253 only if it doesn't already have a value.
3255 The following commands are presently only implemented for native GNU/Linux:
3257 checkpoint Save a snapshot of the program state.
3259 restart <n> Return the program state to a
3260 previously saved state.
3262 info checkpoints List currently saved checkpoints.
3264 delete-checkpoint <n> Delete a previously saved checkpoint.
3266 set|show detach-on-fork Tell gdb whether to detach from a newly
3267 forked process, or to keep debugging it.
3269 info forks List forks of the user program that
3270 are available to be debugged.
3272 fork <n> Switch to debugging one of several
3273 forks of the user program that are
3274 available to be debugged.
3276 delete-fork <n> Delete a fork from the list of forks
3277 that are available to be debugged (and
3278 kill the forked process).
3280 detach-fork <n> Delete a fork from the list of forks
3281 that are available to be debugged (and
3282 allow the process to continue).
3286 Morpho Technologies ms2 ms1-elf
3288 * Improved Windows host support
3290 GDB now builds as a cross debugger hosted on i686-mingw32, including
3291 native console support, and remote communications using either
3292 network sockets or serial ports.
3294 * Improved Modula-2 language support
3296 GDB can now print most types in the Modula-2 syntax. This includes:
3297 basic types, set types, record types, enumerated types, range types,
3298 pointer types and ARRAY types. Procedure var parameters are correctly
3299 printed and hexadecimal addresses and character constants are also
3300 written in the Modula-2 syntax. Best results can be obtained by using
3301 GNU Modula-2 together with the -gdwarf-2 command line option.
3305 The ARM rdi-share module.
3307 The Netware NLM debug server.
3309 *** Changes in GDB 6.4
3311 * New native configurations
3313 OpenBSD/arm arm*-*-openbsd*
3314 OpenBSD/mips64 mips64-*-openbsd*
3318 Morpho Technologies ms1 ms1-elf
3320 * New command line options
3322 --batch-silent As for --batch, but totally silent.
3323 --return-child-result The debugger will exist with the same value
3324 the child (debugged) program exited with.
3325 --eval-command COMMAND, -ex COMMAND
3326 Execute a single GDB CLI command. This may be
3327 specified multiple times and in conjunction
3328 with the --command (-x) option.
3330 * Deprecated commands removed
3332 The following commands, that were deprecated in 2000, have been
3336 set|show arm disassembly-flavor set|show arm disassembler
3337 othernames set arm disassembler
3338 set|show remotedebug set|show debug remote
3339 set|show archdebug set|show debug arch
3340 set|show eventdebug set|show debug event
3343 * New BSD user-level threads support
3345 It is now possible to debug programs using the user-level threads
3346 library on OpenBSD and FreeBSD. Currently supported (target)
3349 FreeBSD/amd64 x86_64-*-freebsd*
3350 FreeBSD/i386 i386-*-freebsd*
3351 OpenBSD/i386 i386-*-openbsd*
3353 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3354 are not yet supported.
3356 * New support for Matsushita MN10300 w/sim added
3357 (Work in progress). mn10300-elf.
3359 * REMOVED configurations and files
3361 VxWorks and the XDR protocol *-*-vxworks
3362 Motorola MCORE mcore-*-*
3363 National Semiconductor NS32000 ns32k-*-*
3365 * New "set print array-indexes" command
3367 After turning this setting "on", GDB prints the index of each element
3368 when displaying arrays. The default is "off" to preserve the previous
3371 * VAX floating point support
3373 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3375 * User-defined command support
3377 In addition to using $arg0..$arg9 for argument passing, it is now possible
3378 to use $argc to determine now many arguments have been passed. See the
3379 section on user-defined commands in the user manual for more information.
3381 *** Changes in GDB 6.3:
3383 * New command line option
3385 GDB now accepts -l followed by a number to set the timeout for remote
3388 * GDB works with GCC -feliminate-dwarf2-dups
3390 GDB now supports a more compact representation of DWARF-2 debug
3391 information using DW_FORM_ref_addr references. These are produced
3392 by GCC with the option -feliminate-dwarf2-dups and also by some
3393 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3394 to use -feliminate-dwarf2-dups.
3396 * Internationalization
3398 When supported by the host system, GDB will be built with
3399 internationalization (libintl). The task of marking up the sources is
3400 continued, we're looking forward to our first translation.
3404 Initial support for debugging programs compiled with the GNAT
3405 implementation of the Ada programming language has been integrated
3406 into GDB. In this release, support is limited to expression evaluation.
3408 * New native configurations
3410 GNU/Linux/m32r m32r-*-linux-gnu
3414 GDB's remote protocol now includes support for the 'p' packet. This
3415 packet is used to fetch individual registers from a remote inferior.
3417 * END-OF-LIFE registers[] compatibility module
3419 GDB's internal register infrastructure has been completely rewritten.
3420 The new infrastructure making possible the implementation of key new
3421 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3424 GDB 6.3 will be the last release to include the the registers[]
3425 compatibility module that allowed out-of-date configurations to
3426 continue to work. This change directly impacts the following
3436 powerpc bdm protocol
3438 Unless there is activity to revive these configurations, they will be
3439 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3441 * OBSOLETE configurations and files
3443 Configurations that have been declared obsolete in this release have
3444 been commented out. Unless there is activity to revive these
3445 configurations, the next release of GDB will have their sources
3446 permanently REMOVED.
3455 *** Changes in GDB 6.2.1:
3457 * MIPS `break main; run' gave an heuristic-fence-post warning
3459 When attempting to run even a simple program, a warning about
3460 heuristic-fence-post being hit would be reported. This problem has
3463 * MIPS IRIX 'long double' crashed GDB
3465 When examining a long double variable, GDB would get a segmentation
3466 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3467 IRIX long double values).
3471 A bug in the VAX stack code was causing problems with the "next"
3472 command. This problem has been fixed.
3474 *** Changes in GDB 6.2:
3476 * Fix for ``many threads''
3478 On GNU/Linux systems that use the NPTL threads library, a program
3479 rapidly creating and deleting threads would confuse GDB leading to the
3482 ptrace: No such process.
3483 thread_db_get_info: cannot get thread info: generic error
3485 This problem has been fixed.
3487 * "-async" and "-noasync" options removed.
3489 Support for the broken "-noasync" option has been removed (it caused
3492 * New ``start'' command.
3494 This command runs the program until the begining of the main procedure.
3496 * New BSD Kernel Data Access Library (libkvm) interface
3498 Using ``target kvm'' it is now possible to debug kernel core dumps and
3499 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3500 platforms. Currently supported (native-only) configurations are:
3502 FreeBSD/amd64 x86_64-*-freebsd*
3503 FreeBSD/i386 i?86-*-freebsd*
3504 NetBSD/i386 i?86-*-netbsd*
3505 NetBSD/m68k m68*-*-netbsd*
3506 NetBSD/sparc sparc-*-netbsd*
3507 OpenBSD/amd64 x86_64-*-openbsd*
3508 OpenBSD/i386 i?86-*-openbsd*
3509 OpenBSD/m68k m68*-openbsd*
3510 OpenBSD/sparc sparc-*-openbsd*
3512 * Signal trampoline code overhauled
3514 Many generic problems with GDB's signal handling code have been fixed.
3515 These include: backtraces through non-contiguous stacks; recognition
3516 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3517 call; backtrace through a signal trampoline; step into and out of
3518 signal handlers; and single-stepping in the signal trampoline.
3520 Please note that kernel bugs are a limiting factor here. These
3521 features have been shown to work on an s390 GNU/Linux system that
3522 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3524 * Cygwin support for DWARF 2 added.
3526 * New native configurations
3528 GNU/Linux/hppa hppa*-*-linux*
3529 OpenBSD/hppa hppa*-*-openbsd*
3530 OpenBSD/m68k m68*-*-openbsd*
3531 OpenBSD/m88k m88*-*-openbsd*
3532 OpenBSD/powerpc powerpc-*-openbsd*
3533 NetBSD/vax vax-*-netbsd*
3534 OpenBSD/vax vax-*-openbsd*
3536 * END-OF-LIFE frame compatibility module
3538 GDB's internal frame infrastructure has been completely rewritten.
3539 The new infrastructure making it possible to support key new features
3540 including DWARF 2 Call Frame Information. To aid in the task of
3541 migrating old configurations to this new infrastructure, a
3542 compatibility module, that allowed old configurations to continue to
3543 work, was also included.
3545 GDB 6.2 will be the last release to include this frame compatibility
3546 module. This change directly impacts the following configurations:
3556 Unless there is activity to revive these configurations, they will be
3557 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3559 * REMOVED configurations and files
3561 Sun 3, running SunOS 3 m68*-*-sunos3*
3562 Sun 3, running SunOS 4 m68*-*-sunos4*
3563 Sun 2, running SunOS 3 m68000-*-sunos3*
3564 Sun 2, running SunOS 4 m68000-*-sunos4*
3565 Motorola 680x0 running LynxOS m68*-*-lynxos*
3566 AT&T 3b1/Unix pc m68*-att-*
3567 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3568 decstation mips-dec-* mips-little-*
3569 riscos mips-*-riscos* mips-*-sysv*
3570 sonymips mips-sony-*
3571 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3573 *** Changes in GDB 6.1.1:
3575 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3577 The TUI (Text-mode User Interface) is now built as part of a default
3578 GDB configuration. It is enabled by either selecting the TUI with the
3579 command line option "-i=tui" or by running the separate "gdbtui"
3580 program. For more information on the TUI, see the manual "Debugging
3583 * Pending breakpoint support (also included in GDB 6.1)
3585 Support has been added to allow you to specify breakpoints in shared
3586 libraries that have not yet been loaded. If a breakpoint location
3587 cannot be found, and the "breakpoint pending" option is set to auto,
3588 GDB queries you if you wish to make the breakpoint pending on a future
3589 shared-library load. If and when GDB resolves the breakpoint symbol,
3590 the pending breakpoint is removed as one or more regular breakpoints
3593 Pending breakpoints are very useful for GCJ Java debugging.
3595 * Fixed ISO-C build problems
3597 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3598 non ISO-C code that stopped them being built using a more strict ISO-C
3599 compiler (e.g., IBM's C compiler).
3601 * Fixed build problem on IRIX 5
3603 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3604 wasn't able to compile compile on an IRIX 5 system.
3606 * Added execute permission to gdb/gdbserver/configure
3608 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3609 permission. This bug would cause configure to fail on a number of
3610 systems (Solaris, IRIX). Ref: server/519.
3612 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3614 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3615 has been updated to use constant array sizes.
3617 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3619 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3620 its generated DWARF Call Frame Info. This encoding was causing GDB to
3621 panic, that panic has been fixed. Ref: gdb/1628.
3623 * Fixed a problem when examining parameters in shared library code.
3625 When examining parameters in optimized shared library code generated
3626 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3627 not available''. GDB now correctly displays the variable's value.
3629 *** Changes in GDB 6.1:
3631 * Removed --with-mmalloc
3633 Support for the mmalloc memory manager has been removed, as it
3634 conflicted with the internal gdb byte cache.
3636 * Changes in AMD64 configurations
3638 The AMD64 target now includes the %cs and %ss registers. As a result
3639 the AMD64 remote protocol has changed; this affects the floating-point
3640 and SSE registers. If you rely on those registers for your debugging,
3641 you should upgrade gdbserver on the remote side.
3643 * Revised SPARC target
3645 The SPARC target has been completely revised, incorporating the
3646 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3647 support for LynxOS and SunOS 4 has been dropped. Calling functions
3648 from within GDB on operating systems with a non-executable stack
3649 (Solaris, OpenBSD) now works.
3653 GDB has a new C++ demangler which does a better job on the mangled
3654 names generated by current versions of g++. It also runs faster, so
3655 with this and other changes gdb should now start faster on large C++
3658 * DWARF 2 Location Expressions
3660 GDB support for location expressions has been extended to support function
3661 arguments and frame bases. Older versions of GDB could crash when they
3664 * C++ nested types and namespaces
3666 GDB's support for nested types and namespaces in C++ has been
3667 improved, especially if you use the DWARF 2 debugging format. (This
3668 is the default for recent versions of GCC on most platforms.)
3669 Specifically, if you have a class "Inner" defined within a class or
3670 namespace "Outer", then GDB realizes that the class's name is
3671 "Outer::Inner", not simply "Inner". This should greatly reduce the
3672 frequency of complaints about not finding RTTI symbols. In addition,
3673 if you are stopped at inside of a function defined within a namespace,
3674 GDB modifies its name lookup accordingly.
3676 * New native configurations
3678 NetBSD/amd64 x86_64-*-netbsd*
3679 OpenBSD/amd64 x86_64-*-openbsd*
3680 OpenBSD/alpha alpha*-*-openbsd*
3681 OpenBSD/sparc sparc-*-openbsd*
3682 OpenBSD/sparc64 sparc64-*-openbsd*
3684 * New debugging protocols
3686 M32R with SDI protocol m32r-*-elf*
3688 * "set prompt-escape-char" command deleted.
3690 The command "set prompt-escape-char" has been deleted. This command,
3691 and its very obscure effet on GDB's prompt, was never documented,
3692 tested, nor mentioned in the NEWS file.
3694 * OBSOLETE configurations and files
3696 Configurations that have been declared obsolete in this release have
3697 been commented out. Unless there is activity to revive these
3698 configurations, the next release of GDB will have their sources
3699 permanently REMOVED.
3701 Sun 3, running SunOS 3 m68*-*-sunos3*
3702 Sun 3, running SunOS 4 m68*-*-sunos4*
3703 Sun 2, running SunOS 3 m68000-*-sunos3*
3704 Sun 2, running SunOS 4 m68000-*-sunos4*
3705 Motorola 680x0 running LynxOS m68*-*-lynxos*
3706 AT&T 3b1/Unix pc m68*-att-*
3707 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3708 decstation mips-dec-* mips-little-*
3709 riscos mips-*-riscos* mips-*-sysv*
3710 sonymips mips-sony-*
3711 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3713 * REMOVED configurations and files
3715 SGI Irix-4.x mips-sgi-irix4 or iris4
3716 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3717 Z8000 simulator z8k-zilog-none or z8ksim
3718 Matsushita MN10200 w/simulator mn10200-*-*
3719 H8/500 simulator h8500-hitachi-hms or h8500hms
3720 HP/PA running BSD hppa*-*-bsd*
3721 HP/PA running OSF/1 hppa*-*-osf*
3722 HP/PA Pro target hppa*-*-pro*
3723 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3724 386BSD i[3456]86-*-bsd*
3725 Sequent family i[3456]86-sequent-sysv4*
3726 i[3456]86-sequent-sysv*
3727 i[3456]86-sequent-bsd*
3728 SPARC running LynxOS sparc-*-lynxos*
3729 SPARC running SunOS 4 sparc-*-sunos4*
3730 Tsqware Sparclet sparclet-*-*
3731 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3733 *** Changes in GDB 6.0:
3737 Support for debugging the Objective-C programming language has been
3738 integrated into GDB.
3740 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3742 DWARF 2's Call Frame Information makes available compiler generated
3743 information that more exactly describes the program's run-time stack.
3744 By using this information, GDB is able to provide more robust stack
3747 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3748 have been updated to use a new backtrace mechanism which includes
3749 DWARF 2 CFI support.
3753 GDB's remote protocol has been extended to include support for hosted
3754 file I/O (where the remote target uses GDB's file system). See GDB's
3755 remote protocol documentation for details.
3757 * All targets using the new architecture framework.
3759 All of GDB's targets have been updated to use the new internal
3760 architecture framework. The way is now open for future GDB releases
3761 to include cross-architecture native debugging support (i386 on amd64,
3764 * GNU/Linux's Thread Local Storage (TLS)
3766 GDB now includes support for for the GNU/Linux implementation of
3767 per-thread variables.
3769 * GNU/Linux's Native POSIX Thread Library (NPTL)
3771 GDB's thread code has been updated to work with either the new
3772 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3774 * Separate debug info.
3776 GDB, in conjunction with BINUTILS, now supports a mechanism for
3777 automatically loading debug information from a separate file. Instead
3778 of shipping full debug and non-debug versions of system libraries,
3779 system integrators can now instead ship just the stripped libraries
3780 and optional debug files.
3782 * DWARF 2 Location Expressions
3784 DWARF 2 Location Expressions allow the compiler to more completely
3785 describe the location of variables (even in optimized code) to the
3788 GDB now includes preliminary support for location expressions (support
3789 for DW_OP_piece is still missing).
3793 A number of long standing bugs that caused GDB to die while starting a
3794 Java application have been fixed. GDB's Java support is now
3795 considered "useable".
3797 * GNU/Linux support for fork, vfork, and exec.
3799 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3800 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3803 * GDB supports logging output to a file
3805 There are two new commands, "set logging" and "show logging", which can be
3806 used to capture GDB's output to a file.
3808 * The meaning of "detach" has changed for gdbserver
3810 The "detach" command will now resume the application, as documented. To
3811 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3814 * d10v, m68hc11 `regs' command deprecated
3816 The `info registers' command has been updated so that it displays the
3817 registers using a format identical to the old `regs' command.
3821 A new command, "maint set profile on/off", has been added. This command can
3822 be used to enable or disable profiling while running GDB, to profile a
3823 session or a set of commands. In addition there is a new configure switch,
3824 "--enable-profiling", which will cause GDB to be compiled with profiling
3825 data, for more informative profiling results.
3827 * Default MI syntax changed to "mi2".
3829 The default MI (machine interface) syntax, enabled by the command line
3830 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3831 "mi1", can be enabled by specifying the option "-i=mi1".
3833 Support for the original "mi0" syntax (included in GDB 5.0) has been
3836 Fix for gdb/192: removed extraneous space when displaying frame level.
3837 Fix for gdb/672: update changelist is now output in mi list format.
3838 Fix for gdb/702: a -var-assign that updates the value now shows up
3839 in a subsequent -var-update.
3841 * New native configurations.
3843 FreeBSD/amd64 x86_64-*-freebsd*
3845 * Multi-arched targets.
3847 HP/PA HPUX11 hppa*-*-hpux*
3848 Renesas M32R/D w/simulator m32r-*-elf*
3850 * OBSOLETE configurations and files
3852 Configurations that have been declared obsolete in this release have
3853 been commented out. Unless there is activity to revive these
3854 configurations, the next release of GDB will have their sources
3855 permanently REMOVED.
3857 Z8000 simulator z8k-zilog-none or z8ksim
3858 Matsushita MN10200 w/simulator mn10200-*-*
3859 H8/500 simulator h8500-hitachi-hms or h8500hms
3860 HP/PA running BSD hppa*-*-bsd*
3861 HP/PA running OSF/1 hppa*-*-osf*
3862 HP/PA Pro target hppa*-*-pro*
3863 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3864 Sequent family i[3456]86-sequent-sysv4*
3865 i[3456]86-sequent-sysv*
3866 i[3456]86-sequent-bsd*
3867 Tsqware Sparclet sparclet-*-*
3868 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3870 * REMOVED configurations and files
3873 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3874 IBM AIX PS/2 i[3456]86-*-aix
3875 i386 running Mach 3.0 i[3456]86-*-mach3*
3876 i386 running Mach i[3456]86-*-mach*
3877 i386 running OSF/1 i[3456]86-*osf1mk*
3878 HP/Apollo 68k Family m68*-apollo*-sysv*,
3880 m68*-hp-bsd*, m68*-hp-hpux*
3881 Argonaut Risc Chip (ARC) arc-*-*
3882 Mitsubishi D30V d30v-*-*
3883 Fujitsu FR30 fr30-*-elf*
3884 OS/9000 i[34]86-*-os9k
3885 I960 with MON960 i960-*-coff
3887 * MIPS $fp behavior changed
3889 The convenience variable $fp, for the MIPS, now consistently returns
3890 the address of the current frame's base. Previously, depending on the
3891 context, $fp could refer to either $sp or the current frame's base
3892 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3893 The GNU Source-Level Debugger''.
3895 *** Changes in GDB 5.3:
3897 * GNU/Linux shared library multi-threaded performance improved.
3899 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3900 `/proc', in preference to `ptrace' for memory reads. This may result
3901 in an improvement in the start-up time of multi-threaded, shared
3902 library applications when run under GDB. One GDB user writes: ``loads
3903 shared libs like mad''.
3905 * ``gdbserver'' now supports multi-threaded applications on some targets
3907 Support for debugging multi-threaded applications which use
3908 the GNU/Linux LinuxThreads package has been added for
3909 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3910 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3912 * GDB now supports C/C++ preprocessor macros.
3914 GDB now expands preprocessor macro invocations in C/C++ expressions,
3915 and provides various commands for showing macro definitions and how
3918 The new command `macro expand EXPRESSION' expands any macro
3919 invocations in expression, and shows the result.
3921 The new command `show macro MACRO-NAME' shows the definition of the
3922 macro named MACRO-NAME, and where it was defined.
3924 Most compilers don't include information about macros in the debugging
3925 information by default. In GCC 3.1, for example, you need to compile
3926 your program with the options `-gdwarf-2 -g3'. If the macro
3927 information is present in the executable, GDB will read it.
3929 * Multi-arched targets.
3931 DEC Alpha (partial) alpha*-*-*
3932 DEC VAX (partial) vax-*-*
3934 National Semiconductor NS32000 (partial) ns32k-*-*
3935 Motorola 68000 (partial) m68k-*-*
3936 Motorola MCORE mcore-*-*
3940 Fujitsu FRV architecture added by Red Hat frv*-*-*
3943 * New native configurations
3945 Alpha NetBSD alpha*-*-netbsd*
3946 SH NetBSD sh*-*-netbsdelf*
3947 MIPS NetBSD mips*-*-netbsd*
3948 UltraSPARC NetBSD sparc64-*-netbsd*
3950 * OBSOLETE configurations and files
3952 Configurations that have been declared obsolete in this release have
3953 been commented out. Unless there is activity to revive these
3954 configurations, the next release of GDB will have their sources
3955 permanently REMOVED.
3957 Mitsubishi D30V d30v-*-*
3958 OS/9000 i[34]86-*-os9k
3959 IBM AIX PS/2 i[3456]86-*-aix
3960 Fujitsu FR30 fr30-*-elf*
3961 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3962 Argonaut Risc Chip (ARC) arc-*-*
3963 i386 running Mach 3.0 i[3456]86-*-mach3*
3964 i386 running Mach i[3456]86-*-mach*
3965 i386 running OSF/1 i[3456]86-*osf1mk*
3966 HP/Apollo 68k Family m68*-apollo*-sysv*,
3968 m68*-hp-bsd*, m68*-hp-hpux*
3969 I960 with MON960 i960-*-coff
3971 * OBSOLETE languages
3973 CHILL, a Pascal like language used by telecommunications companies.
3975 * REMOVED configurations and files
3977 AMD 29k family via UDI a29k-amd-udi, udi29k
3978 A29K VxWorks a29k-*-vxworks
3979 AMD 29000 embedded, using EBMON a29k-none-none
3980 AMD 29000 embedded with COFF a29k-none-coff
3981 AMD 29000 embedded with a.out a29k-none-aout
3983 testsuite/gdb.hp/gdb.threads-hp/ directory
3985 * New command "set max-user-call-depth <nnn>"
3987 This command allows the user to limit the call depth of user-defined
3988 commands. The default is 1024.
3990 * Changes in FreeBSD/i386 native debugging.
3992 Support for the "generate-core-file" has been added.
3994 * New commands "dump", "append", and "restore".
3996 These commands allow data to be copied from target memory
3997 to a bfd-format or binary file (dump and append), and back
3998 from a file into memory (restore).
4000 * Improved "next/step" support on multi-processor Alpha Tru64.
4002 The previous single-step mechanism could cause unpredictable problems,
4003 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4004 of a software single-step mechanism prevents this.
4006 *** Changes in GDB 5.2.1:
4014 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4015 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4016 Fix, by Joel Brobecker imported from mainline.
4018 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4019 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4020 Fix, by Fred Fish, imported from mainline.
4022 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4023 Surprisingly enough, it works now.
4024 By Michal Ludvig, imported from mainline.
4026 i386 hardware watchpoint support:
4027 avoid misses on second run for some targets.
4028 By Pierre Muller, imported from mainline.
4030 *** Changes in GDB 5.2:
4032 * New command "set trust-readonly-sections on[off]".
4034 This command is a hint that tells gdb that read-only sections
4035 really are read-only (ie. that their contents will not change).
4036 In this mode, gdb will go to the object file rather than the
4037 target to read memory from read-only sections (such as ".text").
4038 This can be a significant performance improvement on some
4039 (notably embedded) targets.
4041 * New command "generate-core-file" (or "gcore").
4043 This new gdb command allows the user to drop a core file of the child
4044 process state at any time. So far it's been implemented only for
4045 GNU/Linux and Solaris, but should be relatively easily ported to other
4046 hosts. Argument is core file name (defaults to core.<pid>).
4048 * New command line option
4050 GDB now accepts --pid or -p followed by a process id.
4052 * Change in command line behavior -- corefiles vs. process ids.
4054 There is a subtle behavior in the way in which GDB handles
4055 command line arguments. The first non-flag argument is always
4056 a program to debug, but the second non-flag argument may either
4057 be a corefile or a process id. Previously, GDB would attempt to
4058 open the second argument as a corefile, and if that failed, would
4059 issue a superfluous error message and then attempt to attach it as
4060 a process. Now, if the second argument begins with a non-digit,
4061 it will be treated as a corefile. If it begins with a digit,
4062 GDB will attempt to attach it as a process, and if no such process
4063 is found, will then attempt to open it as a corefile.
4065 * Changes in ARM configurations.
4067 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4068 configuration is fully multi-arch.
4070 * New native configurations
4072 ARM NetBSD arm*-*-netbsd*
4073 x86 OpenBSD i[3456]86-*-openbsd*
4074 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4075 Sparc64 running FreeBSD sparc64-*-freebsd*
4079 Sanyo XStormy16 xstormy16-elf
4081 * OBSOLETE configurations and files
4083 Configurations that have been declared obsolete in this release have
4084 been commented out. Unless there is activity to revive these
4085 configurations, the next release of GDB will have their sources
4086 permanently REMOVED.
4088 AMD 29k family via UDI a29k-amd-udi, udi29k
4089 A29K VxWorks a29k-*-vxworks
4090 AMD 29000 embedded, using EBMON a29k-none-none
4091 AMD 29000 embedded with COFF a29k-none-coff
4092 AMD 29000 embedded with a.out a29k-none-aout
4094 testsuite/gdb.hp/gdb.threads-hp/ directory
4096 * REMOVED configurations and files
4098 TI TMS320C80 tic80-*-*
4100 PowerPC Solaris powerpcle-*-solaris*
4101 PowerPC Windows NT powerpcle-*-cygwin32
4102 PowerPC Netware powerpc-*-netware*
4103 Harris/CXUX m88k m88*-harris-cxux*
4104 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4105 ns32k-utek-sysv* ns32k-utek-*
4106 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4107 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4108 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4109 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4110 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4112 * Changes to command line processing
4114 The new `--args' feature can be used to specify command-line arguments
4115 for the inferior from gdb's command line.
4117 * Changes to key bindings
4119 There is a new `operate-and-get-next' function bound to `C-o'.
4121 *** Changes in GDB 5.1.1
4123 Fix compile problem on DJGPP.
4125 Fix a problem with floating-point registers on the i386 being
4128 Fix to stop GDB crashing on .debug_str debug info.
4130 Numerous documentation fixes.
4132 Numerous testsuite fixes.
4134 *** Changes in GDB 5.1:
4136 * New native configurations
4138 Alpha FreeBSD alpha*-*-freebsd*
4139 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4140 MIPS GNU/Linux mips*-*-linux*
4141 MIPS SGI Irix 6.x mips*-sgi-irix6*
4142 ia64 AIX ia64-*-aix*
4143 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4147 Motorola 68HC11 and 68HC12 m68hc11-elf
4149 UltraSparc running GNU/Linux sparc64-*-linux*
4151 * OBSOLETE configurations and files
4153 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4154 Harris/CXUX m88k m88*-harris-cxux*
4155 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4156 ns32k-utek-sysv* ns32k-utek-*
4157 TI TMS320C80 tic80-*-*
4159 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4160 PowerPC Solaris powerpcle-*-solaris*
4161 PowerPC Windows NT powerpcle-*-cygwin32
4162 PowerPC Netware powerpc-*-netware*
4163 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4164 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4165 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4166 Apple Macintosh (MPW) host N/A
4168 stuff.c (Program to stuff files into a specially prepared space in kdb)
4169 kdb-start.c (Main loop for the standalone kernel debugger)
4171 Configurations that have been declared obsolete in this release have
4172 been commented out. Unless there is activity to revive these
4173 configurations, the next release of GDB will have their sources
4174 permanently REMOVED.
4176 * REMOVED configurations and files
4178 Altos 3068 m68*-altos-*
4179 Convex c1-*-*, c2-*-*
4181 ARM RISCix arm-*-* (as host)
4185 * GDB has been converted to ISO C.
4187 GDB's source code has been converted to ISO C. In particular, the
4188 sources are fully protoized, and rely on standard headers being
4193 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4195 * The MI enabled by default.
4197 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4198 revised and enabled by default. Packages which use GDB as a debugging
4199 engine behind a UI or another front end are encouraged to switch to
4200 using the GDB/MI interface, instead of the old annotations interface
4201 which is now deprecated.
4203 * Support for debugging Pascal programs.
4205 GDB now includes support for debugging Pascal programs. The following
4206 main features are supported:
4208 - Pascal-specific data types such as sets;
4210 - automatic recognition of Pascal sources based on file-name
4213 - Pascal-style display of data types, variables, and functions;
4215 - a Pascal expression parser.
4217 However, some important features are not yet supported.
4219 - Pascal string operations are not supported at all;
4221 - there are some problems with boolean types;
4223 - Pascal type hexadecimal constants are not supported
4224 because they conflict with the internal variables format;
4226 - support for Pascal objects and classes is not full yet;
4228 - unlike Pascal, GDB is case-sensitive for symbol names.
4230 * Changes in completion.
4232 Commands such as `shell', `run' and `set args', which pass arguments
4233 to inferior programs, now complete on file names, similar to what
4234 users expect at the shell prompt.
4236 Commands which accept locations, such as `disassemble', `print',
4237 `breakpoint', `until', etc. now complete on filenames as well as
4238 program symbols. Thus, if you type "break foob TAB", and the source
4239 files linked into the programs include `foobar.c', that file name will
4240 be one of the candidates for completion. However, file names are not
4241 considered for completion after you typed a colon that delimits a file
4242 name from a name of a function in that file, as in "break foo.c:bar".
4244 `set demangle-style' completes on available demangling styles.
4246 * New platform-independent commands:
4248 It is now possible to define a post-hook for a command as well as a
4249 hook that runs before the command. For more details, see the
4250 documentation of `hookpost' in the GDB manual.
4252 * Changes in GNU/Linux native debugging.
4254 Support for debugging multi-threaded programs has been completely
4255 revised for all platforms except m68k and sparc. You can now debug as
4256 many threads as your system allows you to have.
4258 Attach/detach is supported for multi-threaded programs.
4260 Support for SSE registers was added for x86. This doesn't work for
4261 multi-threaded programs though.
4263 * Changes in MIPS configurations.
4265 Multi-arch support is enabled for all MIPS configurations.
4267 GDB can now be built as native debugger on SGI Irix 6.x systems for
4268 debugging n32 executables. (Debugging 64-bit executables is not yet
4271 * Unified support for hardware watchpoints in all x86 configurations.
4273 Most (if not all) native x86 configurations support hardware-assisted
4274 breakpoints and watchpoints in a unified manner. This support
4275 implements debug register sharing between watchpoints, which allows to
4276 put a virtually infinite number of watchpoints on the same address,
4277 and also supports watching regions up to 16 bytes with several debug
4280 The new maintenance command `maintenance show-debug-regs' toggles
4281 debugging print-outs in functions that insert, remove, and test
4282 watchpoints and hardware breakpoints.
4284 * Changes in the DJGPP native configuration.
4286 New command ``info dos sysinfo'' displays assorted information about
4287 the CPU, OS, memory, and DPMI server.
4289 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4290 display information about segment descriptors stored in GDT, LDT, and
4293 New commands ``info dos pde'' and ``info dos pte'' display entries
4294 from Page Directory and Page Tables (for now works with CWSDPMI only).
4295 New command ``info dos address-pte'' displays the Page Table entry for
4296 a given linear address.
4298 GDB can now pass command lines longer than 126 characters to the
4299 program being debugged (requires an update to the libdbg.a library
4300 which is part of the DJGPP development kit).
4302 DWARF2 debug info is now supported.
4304 It is now possible to `step' and `next' through calls to `longjmp'.
4306 * Changes in documentation.
4308 All GDB documentation was converted to GFDL, the GNU Free
4309 Documentation License.
4311 Tracepoints-related commands are now fully documented in the GDB
4314 TUI, the Text-mode User Interface, is now documented in the manual.
4316 Tracepoints-related commands are now fully documented in the GDB
4319 The "GDB Internals" manual now has an index. It also includes
4320 documentation of `ui_out' functions, GDB coding standards, x86
4321 hardware watchpoints, and memory region attributes.
4323 * GDB's version number moved to ``version.in''
4325 The Makefile variable VERSION has been replaced by the file
4326 ``version.in''. People creating GDB distributions should update the
4327 contents of this file.
4331 GUD support is now a standard part of the EMACS distribution.
4333 *** Changes in GDB 5.0:
4335 * Improved support for debugging FP programs on x86 targets
4337 Unified and much-improved support for debugging floating-point
4338 programs on all x86 targets. In particular, ``info float'' now
4339 displays the FP registers in the same format on all x86 targets, with
4340 greater level of detail.
4342 * Improvements and bugfixes in hardware-assisted watchpoints
4344 It is now possible to watch array elements, struct members, and
4345 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4346 on x86 targets no longer erroneously trigger when the address is
4349 * Improvements in the native DJGPP version of GDB
4351 The distribution now includes all the scripts and auxiliary files
4352 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4353 machines ``out of the box''.
4355 The DJGPP version can now debug programs that use signals. It is
4356 possible to catch signals that happened in the debuggee, deliver
4357 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4358 would kill the program being debugged.) Programs that hook hardware
4359 interrupts (keyboard, timer, etc.) can also be debugged.
4361 It is now possible to debug DJGPP programs that redirect their
4362 standard handles or switch them to raw (as opposed to cooked) mode, or
4363 even close them. The command ``run < foo > bar'' works as expected,
4364 and ``info terminal'' reports useful information about the debuggee's
4365 terminal, including raw/cooked mode, redirection, etc.
4367 The DJGPP version now uses termios functions for console I/O, which
4368 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4371 DOS-style file names with drive letters are now fully supported by
4374 It is now possible to debug DJGPP programs that switch their working
4375 directory. It is also possible to rerun the debuggee any number of
4376 times without restarting GDB; thus, you can use the same setup,
4377 breakpoints, etc. for many debugging sessions.
4379 * New native configurations
4381 ARM GNU/Linux arm*-*-linux*
4382 PowerPC GNU/Linux powerpc-*-linux*
4386 Motorola MCore mcore-*-*
4387 x86 VxWorks i[3456]86-*-vxworks*
4388 PowerPC VxWorks powerpc-*-vxworks*
4389 TI TMS320C80 tic80-*-*
4391 * OBSOLETE configurations
4393 Altos 3068 m68*-altos-*
4394 Convex c1-*-*, c2-*-*
4396 ARM RISCix arm-*-* (as host)
4399 Configurations that have been declared obsolete will be commented out,
4400 but the code will be left in place. If there is no activity to revive
4401 these configurations before the next release of GDB, the sources will
4402 be permanently REMOVED.
4404 * Gould support removed
4406 Support for the Gould PowerNode and NP1 has been removed.
4408 * New features for SVR4
4410 On SVR4 native platforms (such as Solaris), if you attach to a process
4411 without first loading a symbol file, GDB will now attempt to locate and
4412 load symbols from the running process's executable file.
4414 * Many C++ enhancements
4416 C++ support has been greatly improved. Overload resolution now works properly
4417 in almost all cases. RTTI support is on the way.
4419 * Remote targets can connect to a sub-program
4421 A popen(3) style serial-device has been added. This device starts a
4422 sub-process (such as a stand-alone simulator) and then communicates
4423 with that. The sub-program to run is specified using the syntax
4424 ``|<program> <args>'' vis:
4426 (gdb) set remotedebug 1
4427 (gdb) target extended-remote |mn10300-elf-sim program-args
4429 * MIPS 64 remote protocol
4431 A long standing bug in the mips64 remote protocol where by GDB
4432 expected certain 32 bit registers (ex SR) to be transfered as 32
4433 instead of 64 bits has been fixed.
4435 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4436 added to provide backward compatibility with older versions of GDB.
4438 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4440 The command ``set remotebinarydownload'' command has been replaced by
4441 ``set remote X-packet''. Other commands in ``set remote'' family
4442 include ``set remote P-packet''.
4444 * Breakpoint commands accept ranges.
4446 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4447 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4448 ``tracepoint passcount'' also accepts a range of tracepoints.
4450 * ``apropos'' command added.
4452 The ``apropos'' command searches through command names and
4453 documentation strings, printing out matches, making it much easier to
4454 try to find a command that does what you are looking for.
4458 A new machine oriented interface (MI) has been added to GDB. This
4459 interface is designed for debug environments running GDB as a separate
4460 process. This is part of the long term libGDB project. See the
4461 "GDB/MI" chapter of the GDB manual for further information. It can be
4462 enabled by configuring with:
4464 .../configure --enable-gdbmi
4466 *** Changes in GDB-4.18:
4468 * New native configurations
4470 HP-UX 10.20 hppa*-*-hpux10.20
4471 HP-UX 11.x hppa*-*-hpux11.0*
4472 M68K GNU/Linux m68*-*-linux*
4476 Fujitsu FR30 fr30-*-elf*
4477 Intel StrongARM strongarm-*-*
4478 Mitsubishi D30V d30v-*-*
4480 * OBSOLETE configurations
4482 Gould PowerNode, NP1 np1-*-*, pn-*-*
4484 Configurations that have been declared obsolete will be commented out,
4485 but the code will be left in place. If there is no activity to revive
4486 these configurations before the next release of GDB, the sources will
4487 be permanently REMOVED.
4491 As a compatibility experiment, GDB's source files buildsym.h and
4492 buildsym.c have been converted to pure standard C, no longer
4493 containing any K&R compatibility code. We believe that all systems in
4494 use today either come with a standard C compiler, or have a GCC port
4495 available. If this is not true, please report the affected
4496 configuration to bug-gdb@gnu.org immediately. See the README file for
4497 information about getting a standard C compiler if you don't have one
4502 GDB now uses readline 2.2.
4504 * set extension-language
4506 You can now control the mapping between filename extensions and source
4507 languages by using the `set extension-language' command. For instance,
4508 you can ask GDB to treat .c files as C++ by saying
4509 set extension-language .c c++
4510 The command `info extensions' lists all of the recognized extensions
4511 and their associated languages.
4513 * Setting processor type for PowerPC and RS/6000
4515 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4516 you can use the `set processor' command to specify what variant of the
4517 PowerPC family you are debugging. The command
4521 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4522 following PowerPC and RS6000 variants:
4524 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4525 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4527 403GC IBM PowerPC 403GC
4528 505 Motorola PowerPC 505
4529 860 Motorola PowerPC 860 or 850
4530 601 Motorola PowerPC 601
4531 602 Motorola PowerPC 602
4532 603 Motorola/IBM PowerPC 603 or 603e
4533 604 Motorola PowerPC 604 or 604e
4534 750 Motorola/IBM PowerPC 750 or 750
4536 At the moment, this command just tells GDB what to name the
4537 special-purpose processor registers. Since almost all the affected
4538 registers are inaccessible to user-level programs, this command is
4539 only useful for remote debugging in its present form.
4543 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4544 more extensive support for HP-UX. Added features include shared
4545 library support, kernel threads and hardware watchpoints for 11.00,
4546 support for HP's ANSI C and C++ compilers, and a compatibility mode
4547 for xdb and dbx commands.
4551 HP's donation includes the new concept of catchpoints, which is a
4552 generalization of the old catch command. On HP-UX, it is now possible
4553 to catch exec, fork, and vfork, as well as library loading.
4555 This means that the existing catch command has changed; its first
4556 argument now specifies the type of catch to be set up. See the
4557 output of "help catch" for a list of catchpoint types.
4559 * Debugging across forks
4561 On HP-UX, you can choose which process to debug when a fork() happens
4566 HP has donated a curses-based terminal user interface (TUI). To get
4567 it, build with --enable-tui. Although this can be enabled for any
4568 configuration, at present it only works for native HP debugging.
4570 * GDB remote protocol additions
4572 A new protocol packet 'X' that writes binary data is now available.
4573 Default behavior is to try 'X', then drop back to 'M' if the stub
4574 fails to respond. The settable variable `remotebinarydownload'
4575 allows explicit control over the use of 'X'.
4577 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4578 full 64-bit address. The command
4580 set remoteaddresssize 32
4582 can be used to revert to the old behaviour. For existing remote stubs
4583 the change should not be noticed, as the additional address information
4586 In order to assist in debugging stubs, you may use the maintenance
4587 command `packet' to send any text string to the stub. For instance,
4589 maint packet heythere
4591 sends the packet "$heythere#<checksum>". Note that it is very easy to
4592 disrupt a debugging session by sending the wrong packet at the wrong
4595 The compare-sections command allows you to compare section data on the
4596 target to what is in the executable file without uploading or
4597 downloading, by comparing CRC checksums.
4599 * Tracing can collect general expressions
4601 You may now collect general expressions at tracepoints. This requires
4602 further additions to the target-side stub; see tracepoint.c and
4603 doc/agentexpr.texi for further details.
4605 * mask-address variable for Mips
4607 For Mips targets, you may control the zeroing of the upper 32 bits of
4608 a 64-bit address by entering `set mask-address on'. This is mainly
4609 of interest to users of embedded R4xxx and R5xxx processors.
4611 * Higher serial baud rates
4613 GDB's serial code now allows you to specify baud rates 57600, 115200,
4614 230400, and 460800 baud. (Note that your host system may not be able
4615 to achieve all of these rates.)
4619 The i960 configuration now includes an initial implementation of a
4620 builtin simulator, contributed by Jim Wilson.
4623 *** Changes in GDB-4.17:
4625 * New native configurations
4627 Alpha GNU/Linux alpha*-*-linux*
4628 Unixware 2.x i[3456]86-unixware2*
4629 Irix 6.x mips*-sgi-irix6*
4630 PowerPC GNU/Linux powerpc-*-linux*
4631 PowerPC Solaris powerpcle-*-solaris*
4632 Sparc GNU/Linux sparc-*-linux*
4633 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4637 Argonaut Risc Chip (ARC) arc-*-*
4638 Hitachi H8/300S h8300*-*-*
4639 Matsushita MN10200 w/simulator mn10200-*-*
4640 Matsushita MN10300 w/simulator mn10300-*-*
4641 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4642 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4643 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4644 Mitsubishi D10V w/simulator d10v-*-*
4645 Mitsubishi M32R/D w/simulator m32r-*-elf*
4646 Tsqware Sparclet sparclet-*-*
4647 NEC V850 w/simulator v850-*-*
4649 * New debugging protocols
4651 ARM with RDI protocol arm*-*-*
4652 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4653 DDB and LSI variants of PMON protocol mips*-*-*
4654 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4655 PowerPC with SDS protocol powerpc{,le}-*-eabi
4656 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4660 All configurations can now understand and use the DWARF 2 debugging
4661 format. The choice is automatic, if the symbol file contains DWARF 2
4666 GDB now includes basic Java language support. This support is
4667 only useful with Java compilers that produce native machine code.
4669 * solib-absolute-prefix and solib-search-path
4671 For SunOS and SVR4 shared libraries, you may now set the prefix for
4672 loading absolute shared library symbol files, and the search path for
4673 locating non-absolute shared library symbol files.
4675 * Live range splitting
4677 GDB can now effectively debug code for which GCC has performed live
4678 range splitting as part of its optimization. See gdb/doc/LRS for
4679 more details on the expected format of the stabs information.
4683 GDB's support for the GNU Hurd, including thread debugging, has been
4684 updated to work with current versions of the Hurd.
4688 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4689 instruction set. ARM GDB automatically detects when Thumb
4690 instructions are in use, and adjusts disassembly and backtracing
4695 GDB's MIPS target configurations now handle the MIP16 16-bit
4700 GDB now includes support for overlays; if an executable has been
4701 linked such that multiple sections are based at the same address, GDB
4702 will decide which section to use for symbolic info. You can choose to
4703 control the decision manually, using overlay commands, or implement
4704 additional target-side support and use "overlay load-target" to bring
4705 in the overlay mapping. Do "help overlay" for more detail.
4709 The command "info symbol <address>" displays information about
4710 the symbol at the specified address.
4714 The standard remote protocol now includes an extension that allows
4715 asynchronous collection and display of trace data. This requires
4716 extensive support in the target-side debugging stub. Tracing mode
4717 includes a new interaction mode in GDB and new commands: see the
4718 file tracepoint.c for more details.
4722 Configurations for embedded MIPS now include a simulator contributed
4723 by Cygnus Solutions. The simulator supports the instruction sets
4724 of most MIPS variants.
4728 Sparc configurations may now include the ERC32 simulator contributed
4729 by the European Space Agency. The simulator is not built into
4730 Sparc targets by default; configure with --enable-sim to include it.
4734 For target configurations that may include multiple variants of a
4735 basic architecture (such as MIPS and SH), you may now set the
4736 architecture explicitly. "set arch" sets, "info arch" lists
4737 the possible architectures.
4739 *** Changes in GDB-4.16:
4741 * New native configurations
4743 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4744 M68K NetBSD m68k-*-netbsd*
4745 PowerPC AIX 4.x powerpc-*-aix*
4746 PowerPC MacOS powerpc-*-macos*
4747 PowerPC Windows NT powerpcle-*-cygwin32
4748 RS/6000 AIX 4.x rs6000-*-aix4*
4752 ARM with RDP protocol arm-*-*
4753 I960 with MON960 i960-*-coff
4754 MIPS VxWorks mips*-*-vxworks*
4755 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4756 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4758 Matra Sparclet sparclet-*-*
4762 The powerpc-eabi configuration now includes the PSIM simulator,
4763 contributed by Andrew Cagney, with assistance from Mike Meissner.
4764 PSIM is a very elaborate model of the PowerPC, including not only
4765 basic instruction set execution, but also details of execution unit
4766 performance and I/O hardware. See sim/ppc/README for more details.
4770 GDB now works with Solaris 2.5.
4772 * Windows 95/NT native
4774 GDB will now work as a native debugger on Windows 95 and Windows NT.
4775 To build it from source, you must use the "gnu-win32" environment,
4776 which uses a DLL to emulate enough of Unix to run the GNU tools.
4777 Further information, binaries, and sources are available at
4778 ftp.cygnus.com, under pub/gnu-win32.
4780 * dont-repeat command
4782 If a user-defined command includes the command `dont-repeat', then the
4783 command will not be repeated if the user just types return. This is
4784 useful if the command is time-consuming to run, so that accidental
4785 extra keystrokes don't run the same command many times.
4787 * Send break instead of ^C
4789 The standard remote protocol now includes an option to send a break
4790 rather than a ^C to the target in order to interrupt it. By default,
4791 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4793 * Remote protocol timeout
4795 The standard remote protocol includes a new variable `remotetimeout'
4796 that allows you to set the number of seconds before GDB gives up trying
4797 to read from the target. The default value is 2.
4799 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4801 By default GDB will automatically keep track of objects as they are
4802 loaded and unloaded by the dynamic linker. By using the command `set
4803 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4804 when shared library events occur, thus allowing you to set breakpoints
4805 in shared libraries which are explicitly loaded by the inferior.
4807 Note this feature does not work on hpux8. On hpux9 you must link
4808 /usr/lib/end.o into your program. This feature should work
4809 automatically on hpux10.
4811 * Irix 5.x hardware watchpoint support
4813 Irix 5 configurations now support the use of hardware watchpoints.
4815 * Mips protocol "SYN garbage limit"
4817 When debugging a Mips target using the `target mips' protocol, you
4818 may set the number of characters that GDB will ignore by setting
4819 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4820 every character. The default value is 1050.
4822 * Recording and replaying remote debug sessions
4824 If you set `remotelogfile' to the name of a file, gdb will write to it
4825 a recording of a remote debug session. This recording may then be
4826 replayed back to gdb using "gdbreplay". See gdbserver/README for
4827 details. This is useful when you have a problem with GDB while doing
4828 remote debugging; you can make a recording of the session and send it
4829 to someone else, who can then recreate the problem.
4831 * Speedups for remote debugging
4833 GDB includes speedups for downloading and stepping MIPS systems using
4834 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4835 and more efficient S-record downloading.
4837 * Memory use reductions and statistics collection
4839 GDB now uses less memory and reports statistics about memory usage.
4840 Try the `maint print statistics' command, for example.
4842 *** Changes in GDB-4.15:
4844 * Psymtabs for XCOFF
4846 The symbol reader for AIX GDB now uses partial symbol tables. This
4847 can greatly improve startup time, especially for large executables.
4849 * Remote targets use caching
4851 Remote targets now use a data cache to speed up communication with the
4852 remote side. The data cache could lead to incorrect results because
4853 it doesn't know about volatile variables, thus making it impossible to
4854 debug targets which use memory mapped I/O devices. `set remotecache
4855 off' turns the the data cache off.
4857 * Remote targets may have threads
4859 The standard remote protocol now includes support for multiple threads
4860 in the target system, using new protocol commands 'H' and 'T'. See
4861 gdb/remote.c for details.
4865 If GDB is configured with `--enable-netrom', then it will include
4866 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4867 acts as though it is a bank of ROM on the target board, but you can
4868 write into it over the network. GDB's support consists only of
4869 support for fast loading into the emulated ROM; to debug, you must use
4870 another protocol, such as standard remote protocol. The usual
4871 sequence is something like
4873 target nrom <netrom-hostname>
4875 target remote <netrom-hostname>:1235
4879 GDB now includes support for the Apple Macintosh, as a host only. It
4880 may be run as either an MPW tool or as a standalone application, and
4881 it can debug through the serial port. All the usual GDB commands are
4882 available, but to the target command, you must supply "serial" as the
4883 device type instead of "/dev/ttyXX". See mpw-README in the main
4884 directory for more information on how to build. The MPW configuration
4885 scripts */mpw-config.in support only a few targets, and only the
4886 mips-idt-ecoff target has been tested.
4890 GDB configuration now uses autoconf. This is not user-visible,
4891 but does simplify configuration and building.
4895 GDB now supports hpux10.
4897 *** Changes in GDB-4.14:
4899 * New native configurations
4901 x86 FreeBSD i[345]86-*-freebsd
4902 x86 NetBSD i[345]86-*-netbsd
4903 NS32k NetBSD ns32k-*-netbsd
4904 Sparc NetBSD sparc-*-netbsd
4908 A29K VxWorks a29k-*-vxworks
4909 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4910 CPU32 EST-300 emulator m68*-*-est*
4911 PowerPC ELF powerpc-*-elf
4914 * Alpha OSF/1 support for procfs
4916 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4917 possible to attach to running processes. As the mounting of the /proc
4918 filesystem is optional on the Alpha, GDB automatically determines
4919 the availability of /proc during startup. This can lead to problems
4920 if /proc is unmounted after GDB has been started.
4922 * Arguments to user-defined commands
4924 User commands may accept up to 10 arguments separated by whitespace.
4925 Arguments are accessed within the user command via $arg0..$arg9. A
4928 print $arg0 + $arg1 + $arg2
4930 To execute the command use:
4933 Defines the command "adder" which prints the sum of its three arguments.
4934 Note the arguments are text substitutions, so they may reference variables,
4935 use complex expressions, or even perform inferior function calls.
4937 * New `if' and `while' commands
4939 This makes it possible to write more sophisticated user-defined
4940 commands. Both commands take a single argument, which is the
4941 expression to evaluate, and must be followed by the commands to
4942 execute, one per line, if the expression is nonzero, the list being
4943 terminated by the word `end'. The `if' command list may include an
4944 `else' word, which causes the following commands to be executed only
4945 if the expression is zero.
4947 * Fortran source language mode
4949 GDB now includes partial support for Fortran 77. It will recognize
4950 Fortran programs and can evaluate a subset of Fortran expressions, but
4951 variables and functions may not be handled correctly. GDB will work
4952 with G77, but does not yet know much about symbols emitted by other
4955 * Better HPUX support
4957 Most debugging facilities now work on dynamic executables for HPPAs
4958 running hpux9 or later. You can attach to running dynamically linked
4959 processes, but by default the dynamic libraries will be read-only, so
4960 for instance you won't be able to put breakpoints in them. To change
4961 that behavior do the following before running the program:
4967 This will cause the libraries to be mapped private and read-write.
4968 To revert to the normal behavior, do this:
4974 You cannot set breakpoints or examine data in the library until after
4975 the library is loaded if the function/data symbols do not have
4978 GDB can now also read debug symbols produced by the HP C compiler on
4979 HPPAs (sorry, no C++, Fortran or 68k support).
4981 * Target byte order now dynamically selectable
4983 You can choose which byte order to use with a target system, via the
4984 commands "set endian big" and "set endian little", and you can see the
4985 current setting by using "show endian". You can also give the command
4986 "set endian auto", in which case GDB will use the byte order
4987 associated with the executable. Currently, only embedded MIPS
4988 configurations support dynamic selection of target byte order.
4990 * New DOS host serial code
4992 This version uses DPMI interrupts to handle buffered I/O, so you
4993 no longer need to run asynctsr when debugging boards connected to
4996 *** Changes in GDB-4.13:
4998 * New "complete" command
5000 This lists all the possible completions for the rest of the line, if it
5001 were to be given as a command itself. This is intended for use by emacs.
5003 * Trailing space optional in prompt
5005 "set prompt" no longer adds a space for you after the prompt you set. This
5006 allows you to set a prompt which ends in a space or one that does not.
5008 * Breakpoint hit counts
5010 "info break" now displays a count of the number of times the breakpoint
5011 has been hit. This is especially useful in conjunction with "ignore"; you
5012 can ignore a large number of breakpoint hits, look at the breakpoint info
5013 to see how many times the breakpoint was hit, then run again, ignoring one
5014 less than that number, and this will get you quickly to the last hit of
5017 * Ability to stop printing at NULL character
5019 "set print null-stop" will cause GDB to stop printing the characters of
5020 an array when the first NULL is encountered. This is useful when large
5021 arrays actually contain only short strings.
5023 * Shared library breakpoints
5025 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5026 breakpoints in shared libraries before the executable is run.
5028 * Hardware watchpoints
5030 There is a new hardware breakpoint for the watch command for sparclite
5031 targets. See gdb/sparclite/hw_breakpoint.note.
5033 Hardware watchpoints are also now supported under GNU/Linux.
5037 Annotations have been added. These are for use with graphical interfaces,
5038 and are still experimental. Currently only gdba.el uses these.
5040 * Improved Irix 5 support
5042 GDB now works properly with Irix 5.2.
5044 * Improved HPPA support
5046 GDB now works properly with the latest GCC and GAS.
5048 * New native configurations
5050 Sequent PTX4 i[34]86-sequent-ptx4
5051 HPPA running OSF/1 hppa*-*-osf*
5052 Atari TT running SVR4 m68*-*-sysv4*
5053 RS/6000 LynxOS rs6000-*-lynxos*
5057 OS/9000 i[34]86-*-os9k
5058 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5061 * Hitachi SH7000 and E7000-PC ICE support
5063 There is now support for communicating with the Hitachi E7000-PC ICE.
5064 This is available automatically when GDB is configured for the SH.
5068 As usual, a variety of small fixes and improvements, both generic
5069 and configuration-specific. See the ChangeLog for more detail.
5071 *** Changes in GDB-4.12:
5073 * Irix 5 is now supported
5077 GDB-4.12 on the HPPA has a number of changes which make it unable
5078 to debug the output from the currently released versions of GCC and
5079 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5080 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5081 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5084 *** Changes in GDB-4.11:
5086 * User visible changes:
5090 The "set remotedebug" option is now consistent between the mips remote
5091 target, remote targets using the gdb-specific protocol, UDI (AMD's
5092 debug protocol for the 29k) and the 88k bug monitor. It is now an
5093 integer specifying a debug level (normally 0 or 1, but 2 means more
5094 debugging info for the mips target).
5096 * DEC Alpha native support
5098 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5099 debug info, but GDB works fairly well with the DEC compiler and should
5100 work with a future GCC release. See the README file for a few
5101 Alpha-specific notes.
5103 * Preliminary thread implementation
5105 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5107 * LynxOS native and target support for 386
5109 This release has been hosted on LynxOS 2.2, and also can be configured
5110 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5113 * Improvements in C++ mangling/demangling.
5115 This release has much better g++ debugging, specifically in name
5116 mangling/demangling, virtual function calls, print virtual table,
5117 call methods, ...etc.
5119 *** Changes in GDB-4.10:
5121 * User visible changes:
5123 Remote debugging using the GDB-specific (`target remote') protocol now
5124 supports the `load' command. This is only useful if you have some
5125 other way of getting the stub to the target system, and you can put it
5126 somewhere in memory where it won't get clobbered by the download.
5128 Filename completion now works.
5130 When run under emacs mode, the "info line" command now causes the
5131 arrow to point to the line specified. Also, "info line" prints
5132 addresses in symbolic form (as well as hex).
5134 All vxworks based targets now support a user settable option, called
5135 vxworks-timeout. This option represents the number of seconds gdb
5136 should wait for responses to rpc's. You might want to use this if
5137 your vxworks target is, perhaps, a slow software simulator or happens
5138 to be on the far side of a thin network line.
5142 This release contains support for using a DEC alpha as a GDB host for
5143 cross debugging. Native alpha debugging is not supported yet.
5146 *** Changes in GDB-4.9:
5150 This is the first GDB release which is accompanied by a matching testsuite.
5151 The testsuite requires installation of dejagnu, which should be available
5152 via ftp from most sites that carry GNU software.
5156 'Cfront' style demangling has had its name changed to 'ARM' style, to
5157 emphasize that it was written from the specifications in the C++ Annotated
5158 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5159 disclaimers, it still generated too much confusion with users attempting to
5160 use gdb with AT&T cfront.
5164 GDB now uses a standard remote interface to a simulator library.
5165 So far, the library contains simulators for the Zilog Z8001/2, the
5166 Hitachi H8/300, H8/500 and Super-H.
5168 * New targets supported
5170 H8/300 simulator h8300-hitachi-hms or h8300hms
5171 H8/500 simulator h8500-hitachi-hms or h8500hms
5172 SH simulator sh-hitachi-hms or sh
5173 Z8000 simulator z8k-zilog-none or z8ksim
5174 IDT MIPS board over serial line mips-idt-ecoff
5176 Cross-debugging to GO32 targets is supported. It requires a custom
5177 version of the i386-stub.c module which is integrated with the
5178 GO32 memory extender.
5180 * New remote protocols
5182 MIPS remote debugging protocol.
5184 * New source languages supported
5186 This version includes preliminary support for Chill, a Pascal like language
5187 used by telecommunications companies. Chill support is also being integrated
5188 into the GNU compiler, but we don't know when it will be publically available.
5191 *** Changes in GDB-4.8:
5193 * HP Precision Architecture supported
5195 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5196 version of this support was available as a set of patches from the
5197 University of Utah. GDB does not support debugging of programs
5198 compiled with the HP compiler, because HP will not document their file
5199 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5200 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5202 Many problems in the preliminary version have been fixed.
5204 * Faster and better demangling
5206 We have improved template demangling and fixed numerous bugs in the GNU style
5207 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5208 character types (wchar_t) are now supported. Demangling of each symbol is now
5209 only done once, and is cached when the symbol table for a file is read in.
5210 This results in a small increase in memory usage for C programs, a moderate
5211 increase in memory usage for C++ programs, and a fantastic speedup in
5214 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5215 from the specifications in the Annotated Reference Manual, which AT&T's
5216 compiler does not actually implement.
5218 * G++ multiple inheritance compiler problem
5220 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5221 inheritance lattices was reworked to properly discover ambiguities. We
5222 recently found an example which causes this new algorithm to fail in a
5223 very subtle way, producing bad debug information for those classes.
5224 The file 'gcc.patch' (in this directory) can be applied to gcc to
5225 circumvent the problem. A future GCC release will contain a complete
5228 The previous G++ debug info problem (mentioned below for the gdb-4.7
5229 release) is fixed in gcc version 2.3.2.
5231 * Improved configure script
5233 The `configure' script will now attempt to guess your system type if
5234 you don't supply a host system type. The old scheme of supplying a
5235 host system triplet is preferable over using this. All the magic is
5236 done in the new `config.guess' script. Examine it for details.
5238 We have also brought our configure script much more in line with the FSF's
5239 version. It now supports the --with-xxx options. In particular,
5240 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5241 The resulting GDB will not be able to read arbitrary object file formats --
5242 only the format ``expected'' to be used on the configured target system.
5243 We hope to make this the default in a future release.
5245 * Documentation improvements
5247 There's new internal documentation on how to modify GDB, and how to
5248 produce clean changes to the code. We implore people to read it
5249 before submitting changes.
5251 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5252 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5253 `info' files are also provided. To build `info' files from scratch,
5254 you will need the latest `makeinfo' release, which will be available in
5255 a future texinfo-X.Y release.
5257 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5258 We're not sure exactly which versions have this problem, but it has
5259 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5260 or better. If that isn't possible, there is a patch in
5261 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5262 around this problem.
5266 GDB now supports array constants that can be used in expressions typed in by
5267 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5268 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5271 The new directory `gdb/sparclite' contains a program that demonstrates
5272 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5274 * New native hosts supported
5276 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5277 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5279 * New targets supported
5281 AMD 29k family via UDI a29k-amd-udi or udi29k
5283 * New file formats supported
5285 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5286 HPUX core files, and SCO 3.2v2 core files.
5290 Attaching to processes now works again; thanks for the many bug reports.
5292 We have also stomped on a bunch of core dumps caused by
5293 printf_filtered("%s") problems.
5295 We eliminated a copyright problem on the rpc and ptrace header files
5296 for VxWorks, which was discovered at the last minute during the 4.7
5297 release. You should now be able to build a VxWorks GDB.
5299 You can now interrupt gdb while an attached process is running. This
5300 will cause the attached process to stop, and give control back to GDB.
5302 We fixed problems caused by using too many file descriptors
5303 for reading symbols from object files and libraries. This was
5304 especially a problem for programs that used many (~100) shared
5307 The `step' command now only enters a subroutine if there is line number
5308 information for the subroutine. Otherwise it acts like the `next'
5309 command. Previously, `step' would enter subroutines if there was
5310 any debugging information about the routine. This avoids problems
5311 when using `cc -g1' on MIPS machines.
5313 * Internal improvements
5315 GDB's internal interfaces have been improved to make it easier to support
5316 debugging of multiple languages in the future.
5318 GDB now uses a common structure for symbol information internally.
5319 Minimal symbols (derived from linkage symbols in object files), partial
5320 symbols (from a quick scan of debug information), and full symbols
5321 contain a common subset of information, making it easier to write
5322 shared code that handles any of them.
5324 * New command line options
5326 We now accept --silent as an alias for --quiet.
5330 The memory-mapped-malloc library is now licensed under the GNU Library
5331 General Public License.
5333 *** Changes in GDB-4.7:
5335 * Host/native/target split
5337 GDB has had some major internal surgery to untangle the support for
5338 hosts and remote targets. Now, when you configure GDB for a remote
5339 target, it will no longer load in all of the support for debugging
5340 local programs on the host. When fully completed and tested, this will
5341 ensure that arbitrary host/target combinations are possible.
5343 The primary conceptual shift is to separate the non-portable code in
5344 GDB into three categories. Host specific code is required any time GDB
5345 is compiled on that host, regardless of the target. Target specific
5346 code relates to the peculiarities of the target, but can be compiled on
5347 any host. Native specific code is everything else: it can only be
5348 built when the host and target are the same system. Child process
5349 handling and core file support are two common `native' examples.
5351 GDB's use of /proc for controlling Unix child processes is now cleaner.
5352 It has been split out into a single module under the `target_ops' vector,
5353 plus two native-dependent functions for each system that uses /proc.
5355 * New hosts supported
5357 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5358 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5359 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5361 * New targets supported
5363 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5364 68030 and CPU32 m68030-*-*, m68332-*-*
5366 * New native hosts supported
5368 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5369 (386bsd is not well tested yet)
5370 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5372 * New file formats supported
5374 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5375 supports reading of `a.out.adobe' object files, which are an a.out
5376 format extended with minimal information about multiple sections.
5380 `show copying' is the same as the old `info copying'.
5381 `show warranty' is the same as `info warrantee'.
5382 These were renamed for consistency. The old commands continue to work.
5384 `info handle' is a new alias for `info signals'.
5386 You can now define pre-command hooks, which attach arbitrary command
5387 scripts to any command. The commands in the hook will be executed
5388 prior to the user's command. You can also create a hook which will be
5389 executed whenever the program stops. See gdb.texinfo.
5393 We now deal with Cfront style name mangling, and can even extract type
5394 info from mangled symbols. GDB can automatically figure out which
5395 symbol mangling style your C++ compiler uses.
5397 Calling of methods and virtual functions has been improved as well.
5401 The crash that occured when debugging Sun Ansi-C compiled binaries is
5402 fixed. This was due to mishandling of the extra N_SO stabs output
5405 We also finally got Ultrix 4.2 running in house, and fixed core file
5406 support, with help from a dozen people on the net.
5408 John M. Farrell discovered that the reason that single-stepping was so
5409 slow on all of the Mips based platforms (primarily SGI and DEC) was
5410 that we were trying to demangle and lookup a symbol used for internal
5411 purposes on every instruction that was being stepped through. Changing
5412 the name of that symbol so that it couldn't be mistaken for a C++
5413 mangled symbol sped things up a great deal.
5415 Rich Pixley sped up symbol lookups in general by getting much smarter
5416 about when C++ symbol mangling is necessary. This should make symbol
5417 completion (TAB on the command line) much faster. It's not as fast as
5418 we'd like, but it's significantly faster than gdb-4.6.
5422 A new user controllable variable 'call_scratch_address' can
5423 specify the location of a scratch area to be used when GDB
5424 calls a function in the target. This is necessary because the
5425 usual method of putting the scratch area on the stack does not work
5426 in systems that have separate instruction and data spaces.
5428 We integrated changes to support the 29k UDI (Universal Debugger
5429 Interface), but discovered at the last minute that we didn't have all
5430 of the appropriate copyright paperwork. We are working with AMD to
5431 resolve this, and hope to have it available soon.
5435 We have sped up the remote serial line protocol, especially for targets
5436 with lots of registers. It now supports a new `expedited status' ('T')
5437 message which can be used in place of the existing 'S' status message.
5438 This allows the remote stub to send only the registers that GDB
5439 needs to make a quick decision about single-stepping or conditional
5440 breakpoints, eliminating the need to fetch the entire register set for
5441 each instruction being stepped through.
5443 The GDB remote serial protocol now implements a write-through cache for
5444 registers, only re-reading the registers if the target has run.
5446 There is also a new remote serial stub for SPARC processors. You can
5447 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5448 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5449 processor with a serial port.
5453 Configure.in files have become much easier to read and modify. A new
5454 `table driven' format makes it more obvious what configurations are
5455 supported, and what files each one uses.
5459 There is a new opcodes library which will eventually contain all of the
5460 disassembly routines and opcode tables. At present, it only contains
5461 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5462 disassembler (binutils/objdump) to share these routines.
5464 The libiberty library is now copylefted under the GNU Library General
5465 Public License. This allows more liberal use, and was done so libg++
5466 can use it. This makes no difference to GDB, since the Library License
5467 grants all the rights from the General Public License.
5471 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5472 reference to the stabs symbol info used by the debugger. It is (as far
5473 as we know) the only published document on this fascinating topic. We
5474 encourage you to read it, compare it to the stabs information on your
5475 system, and send improvements on the document in general (to
5476 bug-gdb@prep.ai.mit.edu).
5478 And, of course, many bugs have been fixed.
5481 *** Changes in GDB-4.6:
5483 * Better support for C++ function names
5485 GDB now accepts as input the "demangled form" of C++ overloaded function
5486 names and member function names, and can do command completion on such names
5487 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5488 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5489 Make use of command completion, it is your friend.
5491 GDB also now accepts a variety of C++ mangled symbol formats. They are
5492 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5493 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5494 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5495 for the list of formats.
5497 * G++ symbol mangling problem
5499 Recent versions of gcc have a bug in how they emit debugging information for
5500 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5501 directory) can be applied to gcc to fix the problem. Alternatively, if you
5502 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5503 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5504 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5507 * New 'maintenance' command
5509 All of the commands related to hacking GDB internals have been moved out of
5510 the main command set, and now live behind the 'maintenance' command. This
5511 can also be abbreviated as 'mt'. The following changes were made:
5513 dump-me -> maintenance dump-me
5514 info all-breakpoints -> maintenance info breakpoints
5515 printmsyms -> maintenance print msyms
5516 printobjfiles -> maintenance print objfiles
5517 printpsyms -> maintenance print psymbols
5518 printsyms -> maintenance print symbols
5520 The following commands are new:
5522 maintenance demangle Call internal GDB demangler routine to
5523 demangle a C++ link name and prints the result.
5524 maintenance print type Print a type chain for a given symbol
5526 * Change to .gdbinit file processing
5528 We now read the $HOME/.gdbinit file before processing the argv arguments
5529 (e.g. reading symbol files or core files). This allows global parameters to
5530 be set, which will apply during the symbol reading. The ./.gdbinit is still
5531 read after argv processing.
5533 * New hosts supported
5535 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5537 GNU/Linux support i386-unknown-linux or linux
5539 We are also including code to support the HP/PA running BSD and HPUX. This
5540 is almost guaranteed not to work, as we didn't have time to test or build it
5541 for this release. We are including it so that the more adventurous (or
5542 masochistic) of you can play with it. We also had major problems with the
5543 fact that the compiler that we got from HP doesn't support the -g option.
5546 * New targets supported
5548 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5550 * More smarts about finding #include files
5552 GDB now remembers the compilation directory for all include files, and for
5553 all files from which C is generated (like yacc and lex sources). This
5554 greatly improves GDB's ability to find yacc/lex sources, and include files,
5555 especially if you are debugging your program from a directory different from
5556 the one that contains your sources.
5558 We also fixed a bug which caused difficulty with listing and setting
5559 breakpoints in include files which contain C code. (In the past, you had to
5560 try twice in order to list an include file that you hadn't looked at before.)
5562 * Interesting infernals change
5564 GDB now deals with arbitrary numbers of sections, where the symbols for each
5565 section must be relocated relative to that section's landing place in the
5566 target's address space. This work was needed to support ELF with embedded
5567 stabs used by Solaris-2.0.
5569 * Bug fixes (of course!)
5571 There have been loads of fixes for the following things:
5572 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5573 i960, stabs, DOS(GO32), procfs, etc...
5575 See the ChangeLog for details.
5577 *** Changes in GDB-4.5:
5579 * New machines supported (host and target)
5581 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5583 SGI Irix-4.x mips-sgi-irix4 or iris4
5585 * New malloc package
5587 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5588 Mmalloc is capable of handling mutiple heaps of memory. It is also
5589 capable of saving a heap to a file, and then mapping it back in later.
5590 This can be used to greatly speedup the startup of GDB by using a
5591 pre-parsed symbol table which lives in a mmalloc managed heap. For
5592 more details, please read mmalloc/mmalloc.texi.
5596 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5597 'help info proc' for details.
5599 * MIPS ecoff symbol table format
5601 The code that reads MIPS symbol table format is now supported on all hosts.
5602 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5605 * File name changes for MS-DOS
5607 Many files in the config directories have been renamed to make it easier to
5608 support GDB on MS-DOSe systems (which have very restrictive file name
5609 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5610 environment) is close to working but has some remaining problems. Note
5611 that debugging of DOS programs is not supported, due to limitations
5612 in the ``operating system'', but it can be used to host cross-debugging.
5614 * Cross byte order fixes
5616 Many fixes have been made to support cross debugging of Sparc and MIPS
5617 targets from hosts whose byte order differs.
5619 * New -mapped and -readnow options
5621 If memory-mapped files are available on your system through the 'mmap'
5622 system call, you can use the -mapped option on the `file' or
5623 `symbol-file' commands to cause GDB to write the symbols from your
5624 program into a reusable file. If the program you are debugging is
5625 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5626 Future GDB debugging sessions will notice the presence of this file,
5627 and will quickly map in symbol information from it, rather than reading
5628 the symbol table from the executable program. Using the '-mapped'
5629 option in a GDB `file' or `symbol-file' command has the same effect as
5630 starting GDB with the '-mapped' command-line option.
5632 You can cause GDB to read the entire symbol table immediately by using
5633 the '-readnow' option with any of the commands that load symbol table
5634 information (or on the GDB command line). This makes the command
5635 slower, but makes future operations faster.
5637 The -mapped and -readnow options are typically combined in order to
5638 build a `fred.syms' file that contains complete symbol information.
5639 A simple GDB invocation to do nothing but build a `.syms' file for future
5642 gdb -batch -nx -mapped -readnow programname
5644 The `.syms' file is specific to the host machine on which GDB is run.
5645 It holds an exact image of GDB's internal symbol table. It cannot be
5646 shared across multiple host platforms.
5648 * longjmp() handling
5650 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5651 siglongjmp() without losing control. This feature has not yet been ported to
5652 all systems. It currently works on many 386 platforms, all MIPS-based
5653 platforms (SGI, DECstation, etc), and Sun3/4.
5657 Preliminary work has been put in to support the new Solaris OS from Sun. At
5658 this time, it can control and debug processes, but it is not capable of
5663 As always, many many bug fixes. The major areas were with g++, and mipsread.
5664 People using the MIPS-based platforms should experience fewer mysterious
5665 crashes and trashed symbol tables.
5667 *** Changes in GDB-4.4:
5669 * New machines supported (host and target)
5671 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5673 BSD Reno on Vax vax-dec-bsd
5674 Ultrix on Vax vax-dec-ultrix
5676 * New machines supported (target)
5678 AMD 29000 embedded, using EBMON a29k-none-none
5682 GDB continues to improve its handling of C++. `References' work better.
5683 The demangler has also been improved, and now deals with symbols mangled as
5684 per the Annotated C++ Reference Guide.
5686 GDB also now handles `stabs' symbol information embedded in MIPS
5687 `ecoff' symbol tables. Since the ecoff format was not easily
5688 extensible to handle new languages such as C++, this appeared to be a
5689 good way to put C++ debugging info into MIPS binaries. This option
5690 will be supported in the GNU C compiler, version 2, when it is
5693 * New features for SVR4
5695 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5696 shared libraries. Debugging dynamically linked programs should present
5697 only minor differences from debugging statically linked programs.
5699 The `info proc' command will print out information about any process
5700 on an SVR4 system (including the one you are debugging). At the moment,
5701 it prints the address mappings of the process.
5703 If you bring up GDB on another SVR4 system, please send mail to
5704 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5706 * Better dynamic linking support in SunOS
5708 Reading symbols from shared libraries which contain debugging symbols
5709 now works properly. However, there remain issues such as automatic
5710 skipping of `transfer vector' code during function calls, which
5711 make it harder to debug code in a shared library, than to debug the
5712 same code linked statically.
5716 GDB is now using the latest `getopt' routines from the FSF. This
5717 version accepts the -- prefix for options with long names. GDB will
5718 continue to accept the old forms (-option and +option) as well.
5719 Various single letter abbreviations for options have been explicity
5720 added to the option table so that they won't get overshadowed in the
5721 future by other options that begin with the same letter.
5725 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5726 Many assorted bugs have been handled. Many more remain to be handled.
5727 See the various ChangeLog files (primarily in gdb and bfd) for details.
5730 *** Changes in GDB-4.3:
5732 * New machines supported (host and target)
5734 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5735 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5736 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5738 * Almost SCO Unix support
5740 We had hoped to support:
5741 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5742 (except for core file support), but we discovered very late in the release
5743 that it has problems with process groups that render gdb unusable. Sorry
5744 about that. I encourage people to fix it and post the fixes.
5746 * Preliminary ELF and DWARF support
5748 GDB can read ELF object files on System V Release 4, and can handle
5749 debugging records for C, in DWARF format, in ELF files. This support
5750 is preliminary. If you bring up GDB on another SVR4 system, please
5751 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5756 GDB now uses the latest `readline' library. One user-visible change
5757 is that two tabs will list possible command completions, which previously
5758 required typing M-? (meta-question mark, or ESC ?).
5762 The `stepi' bug that many of you noticed has been squashed.
5763 Many bugs in C++ have been handled. Many more remain to be handled.
5764 See the various ChangeLog files (primarily in gdb and bfd) for details.
5766 * State of the MIPS world (in case you wondered):
5768 GDB can understand the symbol tables emitted by the compilers
5769 supplied by most vendors of MIPS-based machines, including DEC. These
5770 symbol tables are in a format that essentially nobody else uses.
5772 Some versions of gcc come with an assembler post-processor called
5773 mips-tfile. This program is required if you want to do source-level
5774 debugging of gcc-compiled programs. I believe FSF does not ship
5775 mips-tfile with gcc version 1, but it will eventually come with gcc
5778 Debugging of g++ output remains a problem. g++ version 1.xx does not
5779 really support it at all. (If you're lucky, you should be able to get
5780 line numbers and stack traces to work, but no parameters or local
5781 variables.) With some work it should be possible to improve the
5784 When gcc version 2 is released, you will have somewhat better luck.
5785 However, even then you will get confusing results for inheritance and
5788 We will eventually provide full debugging of g++ output on
5789 DECstations. This will probably involve some kind of stabs-in-ecoff
5790 encapulation, but the details have not been worked out yet.
5793 *** Changes in GDB-4.2:
5795 * Improved configuration
5797 Only one copy of `configure' exists now, and it is not self-modifying.
5798 Porting BFD is simpler.
5802 The `step' and `next' commands now only stop at the first instruction
5803 of a source line. This prevents the multiple stops that used to occur
5804 in switch statements, for-loops, etc. `Step' continues to stop if a
5805 function that has debugging information is called within the line.
5809 Lots of small bugs fixed. More remain.
5811 * New host supported (not target)
5813 Intel 386 PC clone running Mach i386-none-mach
5816 *** Changes in GDB-4.1:
5818 * Multiple source language support
5820 GDB now has internal scaffolding to handle several source languages.
5821 It determines the type of each source file from its filename extension,
5822 and will switch expression parsing and number formatting to match the
5823 language of the function in the currently selected stack frame.
5824 You can also specifically set the language to be used, with
5825 `set language c' or `set language modula-2'.
5829 GDB now has preliminary support for the GNU Modula-2 compiler,
5830 currently under development at the State University of New York at
5831 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5832 continue through the fall of 1991 and into 1992.
5834 Other Modula-2 compilers are currently not supported, and attempting to
5835 debug programs compiled with them will likely result in an error as the
5836 symbol table is read. Feel free to work on it, though!
5838 There are hooks in GDB for strict type checking and range checking,
5839 in the `Modula-2 philosophy', but they do not currently work.
5843 GDB can now write to executable and core files (e.g. patch
5844 a variable's value). You must turn this switch on, specify
5845 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5846 by assigning a new value to a variable. Modifications take
5849 * Automatic SunOS shared library reading
5851 When you run your program, GDB automatically determines where its
5852 shared libraries (if any) have been loaded, and reads their symbols.
5853 The `share' command is no longer needed. This also works when
5854 examining core files.
5858 You can specify the number of lines that the `list' command shows.
5861 * New machines supported (host and target)
5863 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5864 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5865 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5867 * New hosts supported (not targets)
5869 IBM RT/PC: romp-ibm-aix or rtpc
5871 * New targets supported (not hosts)
5873 AMD 29000 embedded with COFF a29k-none-coff
5874 AMD 29000 embedded with a.out a29k-none-aout
5875 Ultracomputer remote kernel debug a29k-nyu-kern
5877 * New remote interfaces
5883 *** Changes in GDB-4.0:
5887 Wide output is wrapped at good places to make the output more readable.
5889 Gdb now supports cross-debugging from a host machine of one type to a
5890 target machine of another type. Communication with the target system
5891 is over serial lines. The ``target'' command handles connecting to the
5892 remote system; the ``load'' command will download a program into the
5893 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5894 also supports debugging of realtime processes running under VxWorks,
5895 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5896 stub on the target system.
5898 New CPUs supported include the AMD 29000 and Intel 960.
5900 GDB now reads object files and symbol tables via a ``binary file''
5901 library, which allows a single copy of GDB to debug programs of multiple
5902 object file types such as a.out and coff.
5904 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5905 refcard.dvi and refcard.ps are available to format it).
5908 * Control-Variable user interface simplified
5910 All variables that control the operation of the debugger can be set
5911 by the ``set'' command, and displayed by the ``show'' command.
5913 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5914 ``Show prompt'' produces the response:
5915 Gdb's prompt is new-gdb=>.
5917 What follows are the NEW set commands. The command ``help set'' will
5918 print a complete list of old and new set commands. ``help set FOO''
5919 will give a longer description of the variable FOO. ``show'' will show
5920 all of the variable descriptions and their current settings.
5922 confirm on/off: Enables warning questions for operations that are
5923 hard to recover from, e.g. rerunning the program while
5924 it is already running. Default is ON.
5926 editing on/off: Enables EMACS style command line editing
5927 of input. Previous lines can be recalled with
5928 control-P, the current line can be edited with control-B,
5929 you can search for commands with control-R, etc.
5932 history filename NAME: NAME is where the gdb command history
5933 will be stored. The default is .gdb_history,
5934 or the value of the environment variable
5937 history size N: The size, in commands, of the command history. The
5938 default is 256, or the value of the environment variable
5941 history save on/off: If this value is set to ON, the history file will
5942 be saved after exiting gdb. If set to OFF, the
5943 file will not be saved. The default is OFF.
5945 history expansion on/off: If this value is set to ON, then csh-like
5946 history expansion will be performed on
5947 command line input. The default is OFF.
5949 radix N: Sets the default radix for input and output. It can be set
5950 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5951 in the current radix, so "set radix 10" is always a no-op.
5953 height N: This integer value is the number of lines on a page. Default
5954 is 24, the current `stty rows'' setting, or the ``li#''
5955 setting from the termcap entry matching the environment
5958 width N: This integer value is the number of characters on a line.
5959 Default is 80, the current `stty cols'' setting, or the ``co#''
5960 setting from the termcap entry matching the environment
5963 Note: ``set screensize'' is obsolete. Use ``set height'' and
5964 ``set width'' instead.
5966 print address on/off: Print memory addresses in various command displays,
5967 such as stack traces and structure values. Gdb looks
5968 more ``symbolic'' if you turn this off; it looks more
5969 ``machine level'' with it on. Default is ON.
5971 print array on/off: Prettyprint arrays. New convenient format! Default
5974 print demangle on/off: Print C++ symbols in "source" form if on,
5977 print asm-demangle on/off: Same, for assembler level printouts
5980 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5983 * Support for Epoch Environment.
5985 The epoch environment is a version of Emacs v18 with windowing. One
5986 new command, ``inspect'', is identical to ``print'', except that if you
5987 are running in the epoch environment, the value is printed in its own
5991 * Support for Shared Libraries
5993 GDB can now debug programs and core files that use SunOS shared libraries.
5994 Symbols from a shared library cannot be referenced
5995 before the shared library has been linked with the program (this
5996 happens after you type ``run'' and before the function main() is entered).
5997 At any time after this linking (including when examining core files
5998 from dynamically linked programs), gdb reads the symbols from each
5999 shared library when you type the ``sharedlibrary'' command.
6000 It can be abbreviated ``share''.
6002 sharedlibrary REGEXP: Load shared object library symbols for files
6003 matching a unix regular expression. No argument
6004 indicates to load symbols for all shared libraries.
6006 info sharedlibrary: Status of loaded shared libraries.
6011 A watchpoint stops execution of a program whenever the value of an
6012 expression changes. Checking for this slows down execution
6013 tremendously whenever you are in the scope of the expression, but is
6014 quite useful for catching tough ``bit-spreader'' or pointer misuse
6015 problems. Some machines such as the 386 have hardware for doing this
6016 more quickly, and future versions of gdb will use this hardware.
6018 watch EXP: Set a watchpoint (breakpoint) for an expression.
6020 info watchpoints: Information about your watchpoints.
6022 delete N: Deletes watchpoint number N (same as breakpoints).
6023 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6024 enable N: Re-enables watchpoint number N (same as breakpoints).
6027 * C++ multiple inheritance
6029 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6032 * C++ exception handling
6034 Gdb now supports limited C++ exception handling. Besides the existing
6035 ability to breakpoint on an exception handler, gdb can breakpoint on
6036 the raising of an exception (before the stack is peeled back to the
6039 catch FOO: If there is a FOO exception handler in the dynamic scope,
6040 set a breakpoint to catch exceptions which may be raised there.
6041 Multiple exceptions (``catch foo bar baz'') may be caught.
6043 info catch: Lists all exceptions which may be caught in the
6044 current stack frame.
6047 * Minor command changes
6049 The command ``call func (arg, arg, ...)'' now acts like the print
6050 command, except it does not print or save a value if the function's result
6051 is void. This is similar to dbx usage.
6053 The ``up'' and ``down'' commands now always print the frame they end up
6054 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6055 frames without printing.
6057 * New directory command
6059 'dir' now adds directories to the FRONT of the source search path.
6060 The path starts off empty. Source files that contain debug information
6061 about the directory in which they were compiled can be found even
6062 with an empty path; Sun CC and GCC include this information. If GDB can't
6063 find your source file in the current directory, type "dir .".
6065 * Configuring GDB for compilation
6067 For normal use, type ``./configure host''. See README or gdb.texinfo
6070 GDB now handles cross debugging. If you are remotely debugging between
6071 two different machines, type ``./configure host -target=targ''.
6072 Host is the machine where GDB will run; targ is the machine
6073 where the program that you are debugging will run.