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 ** Memory ports can now be unbuffered.
57 ** gdb.Objfile objects have a new attribute "username",
58 which is the name of the objfile as specified by the user,
59 without, for example, resolving symlinks.
60 ** You can now write frame unwinders in Python.
61 ** gdb.Type objects have a new method "optimized_out",
62 returning optimized out gdb.Value instance of this type.
63 ** gdb.Value objects have new methods "reference_value" and
64 "const_value" which return a reference to the value and a
65 "const" version of the value respectively.
69 maint print symbol-cache
70 Print the contents of the symbol cache.
72 maint print symbol-cache-statistics
73 Print statistics of symbol cache usage.
75 maint flush-symbol-cache
76 Flush the contents of the symbol cache.
80 Start branch trace recording using Branch Trace Store (BTS) format.
83 Evaluate expression by using the compiler and print result.
89 Set the maximum number of candidates to be considered during
90 completion. The default value is 200. This limit allows GDB
91 to avoid generating large completion lists, the computation of
92 which can cause the debugger to become temporarily unresponsive.
94 maint set symbol-cache-size
95 maint show symbol-cache-size
96 Control the size of the symbol cache.
98 set|show record btrace bts buffer-size
99 Set and show the size of the ring buffer used for branch tracing in
101 The obtained size may differ from the requested size. Use "info
102 record" to see the obtained buffer size.
104 * The command 'thread apply all' can now support new option '-ascending'
105 to call its specified command for all threads in ascending order.
107 * Python/Guile scripting
109 ** GDB now supports auto-loading of Python/Guile scripts contained in the
110 special section named `.debug_gdb_scripts'.
114 qXfer:btrace-conf:read
115 Return the branch trace configuration for the current thread.
117 Qbtrace-conf:bts:size
118 Set the requested ring buffer size for branch tracing in BTS format.
121 Indicates a memory breakpoint instruction was executed, irrespective
122 of whether it was GDB that planted the breakpoint or the breakpoint
123 is hardcoded in the program. This is required for correct non-stop
127 Indicates the target stopped for a hardware breakpoint. This is
128 required for correct non-stop mode operation.
131 Return information about files on the remote system.
134 Return the full absolute name of the file that was executed to
135 create a process running on the remote system.
138 Indicates that a fork system call was executed.
141 Indicates that a vfork system call was executed.
143 vforkdone stop reason
144 Indicates that a vfork child of the specified process has executed
145 an exec or exit, allowing the vfork parent to resume execution.
147 fork-events and vfork-events features in qSupported
148 The qSupported packet allows GDB to request support for fork and
149 vfork events using new 'gdbfeatures' fork-events and vfork-events,
150 and the qSupported response can contain the corresponding
151 'stubfeatures'. Set and show commands can be used to display
152 whether these features are enabled.
154 * Extended-remote fork events
156 ** GDB now has support for fork events on extended-remote Linux
157 targets. For targets with Linux kernels 2.5.60 and later, this
158 enables follow-fork-mode and detach-on-fork for both fork and
159 vfork, as well as fork and vfork catchpoints.
161 * The info record command now shows the recording format and the
162 branch tracing configuration for the current thread when using
163 the btrace record target.
164 For the BTS format, it shows the ring buffer size.
166 * GDB now has support for DTrace USDT (Userland Static Defined
167 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
169 * GDB now supports access to vector registers on S/390 GNU/Linux
172 * Removed command line options
174 -xdb HP-UX XDB compatibility mode.
176 * Removed targets and native configurations
178 HP/PA running HP-UX hppa*-*-hpux*
179 Itanium running HP-UX ia64-*-hpux*
181 *** Changes in GDB 7.9.1
185 ** Xmethods can now specify a result type.
187 *** Changes in GDB 7.9
189 * GDB now supports hardware watchpoints on x86 GNU Hurd.
193 ** You can now access frame registers from Python scripts.
194 ** New attribute 'producer' for gdb.Symtab objects.
195 ** gdb.Objfile objects have a new attribute "progspace",
196 which is the gdb.Progspace object of the containing program space.
197 ** gdb.Objfile objects have a new attribute "owner".
198 ** gdb.Objfile objects have a new attribute "build_id",
199 which is the build ID generated when the file was built.
200 ** gdb.Objfile objects have a new method "add_separate_debug_file".
201 ** A new event "gdb.clear_objfiles" has been added, triggered when
202 selecting a new file to debug.
203 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
204 ** New function gdb.lookup_objfile.
206 New events which are triggered when GDB modifies the state of the
209 ** gdb.events.inferior_call_pre: Function call is about to be made.
210 ** gdb.events.inferior_call_post: Function call has just been made.
211 ** gdb.events.memory_changed: A memory location has been altered.
212 ** gdb.events.register_changed: A register has been altered.
214 * New Python-based convenience functions:
216 ** $_caller_is(name [, number_of_frames])
217 ** $_caller_matches(regexp [, number_of_frames])
218 ** $_any_caller_is(name [, number_of_frames])
219 ** $_any_caller_matches(regexp [, number_of_frames])
221 * GDB now supports the compilation and injection of source code into
222 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
223 to compile the source code to object code, and if successful, inject
224 and execute that code within the current context of the inferior.
225 Currently the C language is supported. The commands used to
226 interface with this new feature are:
228 compile code [-raw|-r] [--] [source code]
229 compile file [-raw|-r] filename
233 demangle [-l language] [--] name
234 Demangle "name" in the specified language, or the current language
235 if elided. This command is renamed from the "maint demangle" command.
236 The latter is kept as a no-op to avoid "maint demangle" being interpreted
237 as "maint demangler-warning".
239 queue-signal signal-name-or-number
240 Queue a signal to be delivered to the thread when it is resumed.
242 add-auto-load-scripts-directory directory
243 Add entries to the list of directories from which to load auto-loaded
246 maint print user-registers
247 List all currently available "user" registers.
249 compile code [-r|-raw] [--] [source code]
250 Compile, inject, and execute in the inferior the executable object
251 code produced by compiling the provided source code.
253 compile file [-r|-raw] filename
254 Compile and inject into the inferior the executable object code
255 produced by compiling the source code stored in the filename
258 * On resume, GDB now always passes the signal the program had stopped
259 for to the thread the signal was sent to, even if the user changed
260 threads before resuming. Previously GDB would often (but not
261 always) deliver the signal to the thread that happens to be current
264 * Conversely, the "signal" command now consistently delivers the
265 requested signal to the current thread. GDB now asks for
266 confirmation if the program had stopped for a signal and the user
267 switched threads meanwhile.
269 * "breakpoint always-inserted" modes "off" and "auto" merged.
271 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
272 won't remove breakpoints from the target until all threads stop,
273 even in non-stop mode. The "auto" mode has been removed, and "off"
274 is now the default mode.
278 set debug symbol-lookup
279 show debug symbol-lookup
280 Control display of debugging info regarding symbol lookup.
284 ** The -list-thread-groups command outputs an exit-code field for
285 inferiors that have exited.
289 MIPS SDE mips*-sde*-elf*
293 Support for these obsolete configurations has been removed.
295 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
296 SGI Irix-5.x mips-*-irix5*
297 SGI Irix-6.x mips-*-irix6*
298 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
299 VAX running Ultrix vax-*-ultrix*
301 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
302 and "assf"), have been removed. Use the "sharedlibrary" command, or
303 its alias "share", instead.
305 *** Changes in GDB 7.8
307 * New command line options
310 This is an alias for the --data-directory option.
312 * GDB supports printing and modifying of variable length automatic arrays
313 as specified in ISO C99.
315 * The ARM simulator now supports instruction level tracing
316 with or without disassembly.
320 GDB now has support for scripting using Guile. Whether this is
321 available is determined at configure time.
322 Guile version 2.0 or greater is required.
323 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
325 * New commands (for set/show, see "New options" below)
329 Invoke CODE by passing it to the Guile interpreter.
333 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
335 info auto-load guile-scripts [regexp]
336 Print the list of automatically loaded Guile scripts.
338 * The source command is now capable of sourcing Guile scripts.
339 This feature is dependent on the debugger being built with Guile support.
343 set print symbol-loading (off|brief|full)
344 show print symbol-loading
345 Control whether to print informational messages when loading symbol
346 information for a file. The default is "full", but when debugging
347 programs with large numbers of shared libraries the amount of output
350 set guile print-stack (none|message|full)
351 show guile print-stack
352 Show a stack trace when an error is encountered in a Guile script.
354 set auto-load guile-scripts (on|off)
355 show auto-load guile-scripts
356 Control auto-loading of Guile script files.
358 maint ada set ignore-descriptive-types (on|off)
359 maint ada show ignore-descriptive-types
360 Control whether the debugger should ignore descriptive types in Ada
361 programs. The default is not to ignore the descriptive types. See
362 the user manual for more details on descriptive types and the intended
363 usage of this option.
365 set auto-connect-native-target
367 Control whether GDB is allowed to automatically connect to the
368 native target for the run, attach, etc. commands when not connected
369 to any target yet. See also "target native" below.
371 set record btrace replay-memory-access (read-only|read-write)
372 show record btrace replay-memory-access
373 Control what memory accesses are allowed during replay.
375 maint set target-async (on|off)
376 maint show target-async
377 This controls whether GDB targets operate in synchronous or
378 asynchronous mode. Normally the default is asynchronous, if it is
379 available; but this can be changed to more easily debug problems
380 occurring only in synchronous mode.
382 set mi-async (on|off)
384 Control whether MI asynchronous mode is preferred. This supersedes
385 "set target-async" of previous GDB versions.
387 * "set target-async" is deprecated as a CLI option and is now an alias
388 for "set mi-async" (only puts MI into async mode).
390 * Background execution commands (e.g., "c&", "s&", etc.) are now
391 possible ``out of the box'' if the target supports them. Previously
392 the user would need to explicitly enable the possibility with the
393 "set target-async on" command.
395 * New features in the GDB remote stub, GDBserver
397 ** New option --debug-format=option1[,option2,...] allows one to add
398 additional text to each output. At present only timestamps
399 are supported: --debug-format=timestamps.
400 Timestamps can also be turned on with the
401 "monitor set debug-format timestamps" command from GDB.
403 * The 'record instruction-history' command now starts counting instructions
404 at one. This also affects the instruction ranges reported by the
405 'record function-call-history' command when given the /i modifier.
407 * The command 'record function-call-history' supports a new modifier '/c' to
408 indent the function names based on their call stack depth.
409 The fields for the '/i' and '/l' modifier have been reordered.
410 The source line range is now prefixed with 'at'.
411 The instruction range is now prefixed with 'inst'.
412 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
413 "record instruction-history" and "list" commands.
415 * The ranges given as arguments to the 'record function-call-history' and
416 'record instruction-history' commands are now inclusive.
418 * The btrace record target now supports the 'record goto' command.
419 For locations inside the execution trace, the back trace is computed
420 based on the information stored in the execution trace.
422 * The btrace record target supports limited reverse execution and replay.
423 The target does not record data and therefore does not allow reading
426 * The "catch syscall" command now works on s390*-linux* targets.
428 * The "compare-sections" command is no longer specific to target
429 remote. It now works with all targets.
431 * All native targets are now consistently called "native".
432 Consequently, the "target child", "target GNU", "target djgpp",
433 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
434 commands have been replaced with "target native". The QNX/NTO port
435 leaves the "procfs" target in place and adds a "native" target for
436 consistency with other ports. The impact on users should be minimal
437 as these commands previously either throwed an error, or were
438 no-ops. The target's name is visible in the output of the following
439 commands: "help target", "info target", "info files", "maint print
442 * The "target native" command now connects to the native target. This
443 can be used to launch native programs even when "set
444 auto-connect-native-target" is set to off.
446 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.
448 * Support for Intel(R) AVX-512 registers on GNU/Linux.
449 Support displaying and modifying Intel(R) AVX-512 registers
450 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
454 qXfer:btrace:read's annex
455 The qXfer:btrace:read packet supports a new annex 'delta' to read
456 branch trace incrementally.
460 ** Valid Python operations on gdb.Value objects representing
461 structs/classes invoke the corresponding overloaded operators if
463 ** New `Xmethods' feature in the Python API. Xmethods are
464 additional methods or replacements for existing methods of a C++
465 class. This feature is useful for those cases where a method
466 defined in C++ source code could be inlined or optimized out by
467 the compiler, making it unavailable to GDB.
470 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
472 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
473 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
474 its alias "share", instead.
476 * The commands "set remotebaud" and "show remotebaud" are no longer
477 supported. Use "set serial baud" and "show serial baud" (respectively)
482 ** A new option "-gdb-set mi-async" replaces "-gdb-set
483 target-async". The latter is left as a deprecated alias of the
484 former for backward compatibility. If the target supports it,
485 CLI background execution commands are now always possible by
486 default, independently of whether the frontend stated a
487 preference for asynchronous execution with "-gdb-set mi-async".
488 Previously "-gdb-set target-async off" affected both MI execution
489 commands and CLI execution commands.
491 *** Changes in GDB 7.7
493 * Improved support for process record-replay and reverse debugging on
494 arm*-linux* targets. Support for thumb32 and syscall instruction
495 recording has been added.
497 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
499 * GDB now supports Fission DWP file format version 2.
500 http://gcc.gnu.org/wiki/DebugFission
502 * New convenience function "$_isvoid", to check whether an expression
503 is void. A void expression is an expression where the type of the
504 result is "void". For example, some convenience variables may be
505 "void" when evaluated (e.g., "$_exitcode" before the execution of
506 the program being debugged; or an undefined convenience variable).
507 Another example, when calling a function whose return type is
510 * The "maintenance print objfiles" command now takes an optional regexp.
512 * The "catch syscall" command now works on arm*-linux* targets.
514 * GDB now consistently shows "<not saved>" when printing values of
515 registers the debug info indicates have not been saved in the frame
516 and there's nowhere to retrieve them from
517 (callee-saved/call-clobbered registers):
522 (gdb) info registers rax
525 Before, the former would print "<optimized out>", and the latter
526 "*value not available*".
528 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
533 ** Frame filters and frame decorators have been added.
534 ** Temporary breakpoints are now supported.
535 ** Line tables representation has been added.
536 ** New attribute 'parent_type' for gdb.Field objects.
537 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
538 ** New attribute 'name' for gdb.Type objects.
542 Nios II ELF nios2*-*-elf
543 Nios II GNU/Linux nios2*-*-linux
544 Texas Instruments MSP430 msp430*-*-elf
546 * Removed native configurations
548 Support for these a.out NetBSD and OpenBSD obsolete configurations has
549 been removed. ELF variants of these configurations are kept supported.
551 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
552 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
553 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
554 i[34567]86-*-openbsd3.[0-3]
555 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
556 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
557 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
561 Like "catch throw", but catches a re-thrown exception.
563 Renamed from old "maint check-symtabs".
565 Perform consistency checks on symtabs.
567 Expand symtabs matching an optional regexp.
570 Display the details of GDB configure-time options.
572 maint set|show per-command
573 maint set|show per-command space
574 maint set|show per-command time
575 maint set|show per-command symtab
576 Enable display of per-command gdb resource usage.
578 remove-symbol-file FILENAME
579 remove-symbol-file -a ADDRESS
580 Remove a symbol file added via add-symbol-file. The file to remove
581 can be identified by its filename or by an address that lies within
582 the boundaries of this symbol file in memory.
585 info exceptions REGEXP
586 Display the list of Ada exceptions defined in the program being
587 debugged. If provided, only the exceptions whose names match REGEXP
592 set debug symfile off|on
594 Control display of debugging info regarding reading symbol files and
595 symbol tables within those files
597 set print raw frame-arguments
598 show print raw frame-arguments
599 Set/show whether to print frame arguments in raw mode,
600 disregarding any defined pretty-printers.
602 set remote trace-status-packet
603 show remote trace-status-packet
604 Set/show the use of remote protocol qTStatus packet.
608 Control display of debugging messages related to Nios II targets.
612 Control whether target-assisted range stepping is enabled.
614 set startup-with-shell
615 show startup-with-shell
616 Specifies whether Unix child processes are started via a shell or
621 Use the target memory cache for accesses to the code segment. This
622 improves performance of remote debugging (particularly disassembly).
624 * You can now use a literal value 'unlimited' for options that
625 interpret 0 or -1 as meaning "unlimited". E.g., "set
626 trace-buffer-size unlimited" is now an alias for "set
627 trace-buffer-size -1" and "set height unlimited" is now an alias for
630 * The "set debug symtab-create" debugging option of GDB has been changed to
631 accept a verbosity level. 0 means "off", 1 provides basic debugging
632 output, and values of 2 or greater provides more verbose output.
634 * New command-line options
636 Display the details of GDB configure-time options.
638 * The command 'tsave' can now support new option '-ctf' to save trace
639 buffer in Common Trace Format.
641 * Newly installed $prefix/bin/gcore acts as a shell interface for the
644 * GDB now implements the the C++ 'typeid' operator.
646 * The new convenience variable $_exception holds the exception being
647 thrown or caught at an exception-related catchpoint.
649 * The exception-related catchpoints, like "catch throw", now accept a
650 regular expression which can be used to filter exceptions by type.
652 * The new convenience variable $_exitsignal is automatically set to
653 the terminating signal number when the program being debugged dies
654 due to an uncaught signal.
658 ** All MI commands now accept an optional "--language" option.
659 Support for this feature can be verified by using the "-list-features"
660 command, which should contain "language-option".
662 ** The new command -info-gdb-mi-command allows the user to determine
663 whether a GDB/MI command is supported or not.
665 ** The "^error" result record returned when trying to execute an undefined
666 GDB/MI command now provides a variable named "code" whose content is the
667 "undefined-command" error code. Support for this feature can be verified
668 by using the "-list-features" command, which should contain
669 "undefined-command-error-code".
671 ** The -trace-save MI command can optionally save trace buffer in Common
674 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
676 ** The command -data-list-register-values now accepts an optional
677 "--skip-unavailable" option. When used, only the available registers
680 ** The new command -trace-frame-collected dumps collected variables,
681 computed expressions, tvars, memory and registers in a traceframe.
683 ** The commands -stack-list-locals, -stack-list-arguments and
684 -stack-list-variables now accept an option "--skip-unavailable".
685 When used, only the available locals or arguments are displayed.
687 ** The -exec-run command now accepts an optional "--start" option.
688 When used, the command follows the same semantics as the "start"
689 command, stopping the program's execution at the start of its
690 main subprogram. Support for this feature can be verified using
691 the "-list-features" command, which should contain
692 "exec-run-start-option".
694 ** The new commands -catch-assert and -catch-exceptions insert
695 catchpoints stopping the program when Ada exceptions are raised.
697 ** The new command -info-ada-exceptions provides the equivalent of
698 the new "info exceptions" command.
700 * New system-wide configuration scripts
701 A GDB installation now provides scripts suitable for use as system-wide
702 configuration scripts for the following systems:
706 * GDB now supports target-assigned range stepping with remote targets.
707 This improves the performance of stepping source lines by reducing
708 the number of control packets from/to GDB. See "New remote packets"
711 * GDB now understands the element 'tvar' in the XML traceframe info.
712 It has the id of the collected trace state variables.
714 * On S/390 targets that provide the transactional-execution feature,
715 the program interruption transaction diagnostic block (TDB) is now
716 represented as a number of additional "registers" in GDB.
722 The vCont packet supports a new 'r' action, that tells the remote
723 stub to step through an address range itself, without GDB
724 involvemement at each single-step.
726 qXfer:libraries-svr4:read's annex
727 The previously unused annex of the qXfer:libraries-svr4:read packet
728 is now used to support passing an argument list. The remote stub
729 reports support for this argument list to GDB's qSupported query.
730 The defined arguments are "start" and "prev", used to reduce work
731 necessary for library list updating, resulting in significant
734 * New features in the GDB remote stub, GDBserver
736 ** GDBserver now supports target-assisted range stepping. Currently
737 enabled on x86/x86_64 GNU/Linux targets.
739 ** GDBserver now adds element 'tvar' in the XML in the reply to
740 'qXfer:traceframe-info:read'. It has the id of the collected
741 trace state variables.
743 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
746 * New 'z' formatter for printing and examining memory, this displays the
747 value as hexadecimal zero padded on the left to the size of the type.
749 * GDB can now use Windows x64 unwinding data.
751 * The "set remotebaud" command has been replaced by "set serial baud".
752 Similarly, "show remotebaud" has been replaced by "show serial baud".
753 The "set remotebaud" and "show remotebaud" commands are still available
754 to provide backward compatibility with older versions of GDB.
756 *** Changes in GDB 7.6
758 * Target record has been renamed to record-full.
759 Record/replay is now enabled with the "record full" command.
760 This also affects settings that are associated with full record/replay
761 that have been moved from "set/show record" to "set/show record full":
763 set|show record full insn-number-max
764 set|show record full stop-at-limit
765 set|show record full memory-query
767 * A new record target "record-btrace" has been added. The new target
768 uses hardware support to record the control-flow of a process. It
769 does not support replaying the execution, but it implements the
770 below new commands for investigating the recorded execution log.
771 This new recording method can be enabled using:
775 The "record-btrace" target is only available on Intel Atom processors
776 and requires a Linux kernel 2.6.32 or later.
778 * Two new commands have been added for record/replay to give information
779 about the recorded execution without having to replay the execution.
780 The commands are only supported by "record btrace".
782 record instruction-history prints the execution history at
783 instruction granularity
785 record function-call-history prints the execution history at
788 * New native configurations
790 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
791 FreeBSD/powerpc powerpc*-*-freebsd
792 x86_64/Cygwin x86_64-*-cygwin*
793 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
797 ARM AArch64 aarch64*-*-elf
798 ARM AArch64 GNU/Linux aarch64*-*-linux
799 Lynx 178 PowerPC powerpc-*-lynx*178
800 x86_64/Cygwin x86_64-*-cygwin*
801 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
803 * If the configured location of system.gdbinit file (as given by the
804 --with-system-gdbinit option at configure time) is in the
805 data-directory (as specified by --with-gdb-datadir at configure
806 time) or in one of its subdirectories, then GDB will look for the
807 system-wide init file in the directory specified by the
808 --data-directory command-line option.
810 * New command line options:
812 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
813 other initialization files, unlike -nx which disables all of them.
815 * Removed command line options
817 -epoch This was used by the gdb mode in Epoch, an ancient fork of
820 * The 'ptype' and 'whatis' commands now accept an argument to control
823 * 'info proc' now works on some core files.
827 ** Vectors can be created with gdb.Type.vector.
829 ** Python's atexit.register now works in GDB.
831 ** Types can be pretty-printed via a Python API.
833 ** Python 3 is now supported (in addition to Python 2.4 or later)
835 ** New class gdb.Architecture exposes GDB's internal representation
836 of architecture in the Python API.
838 ** New method Frame.architecture returns the gdb.Architecture object
839 corresponding to the frame's architecture.
841 * New Python-based convenience functions:
843 ** $_memeq(buf1, buf2, length)
844 ** $_streq(str1, str2)
846 ** $_regex(str, regex)
848 * The 'cd' command now defaults to using '~' (the home directory) if not
851 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
852 default for GCC since November 2000.
854 * The command 'forward-search' can now be abbreviated as 'fo'.
856 * The command 'info tracepoints' can now display 'installed on target'
857 or 'not installed on target' for each non-pending location of tracepoint.
859 * New configure options
861 --enable-libmcheck/--disable-libmcheck
862 By default, development versions are built with -lmcheck on hosts
863 that support it, in order to help track memory corruption issues.
864 Release versions, on the other hand, are built without -lmcheck
865 by default. The --enable-libmcheck/--disable-libmcheck configure
866 options allow the user to override that default.
867 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
868 This configure option allows the user to build GDB with
869 libbabeltrace using which GDB can read Common Trace Format data.
871 * New commands (for set/show, see "New options" below)
874 Catch signals. This is similar to "handle", but allows commands and
875 conditions to be attached.
878 List the BFDs known to GDB.
880 python-interactive [command]
882 Start a Python interactive prompt, or evaluate the optional command
883 and print the result of expressions.
886 "py" is a new alias for "python".
888 enable type-printer [name]...
889 disable type-printer [name]...
890 Enable or disable type printers.
894 ** For the Renesas Super-H architecture, the "regs" command has been removed
895 (has been deprecated in GDB 7.5), and "info all-registers" should be used
900 set print type methods (on|off)
901 show print type methods
902 Control whether method declarations are displayed by "ptype".
903 The default is to show them.
905 set print type typedefs (on|off)
906 show print type typedefs
907 Control whether typedef definitions are displayed by "ptype".
908 The default is to show them.
910 set filename-display basename|relative|absolute
911 show filename-display
912 Control the way in which filenames is displayed.
913 The default is "relative", which preserves previous behavior.
915 set trace-buffer-size
916 show trace-buffer-size
917 Request target to change the size of trace buffer.
919 set remote trace-buffer-size-packet auto|on|off
920 show remote trace-buffer-size-packet
921 Control the use of the remote protocol `QTBuffer:size' packet.
925 Control display of debugging messages related to ARM AArch64.
928 set debug coff-pe-read
929 show debug coff-pe-read
930 Control display of debugging messages related to reading of COFF/PE
935 Control display of debugging messages related to Mach-O symbols
938 set debug notification
939 show debug notification
940 Control display of debugging info for async remote notification.
944 ** Command parameter changes are now notified using new async record
945 "=cmd-param-changed".
946 ** Trace frame changes caused by command "tfind" are now notified using
947 new async record "=traceframe-changed".
948 ** The creation, deletion and modification of trace state variables
949 are now notified using new async records "=tsv-created",
950 "=tsv-deleted" and "=tsv-modified".
951 ** The start and stop of process record are now notified using new
952 async record "=record-started" and "=record-stopped".
953 ** Memory changes are now notified using new async record
955 ** The data-disassemble command response will include a "fullname" field
956 containing the absolute file name when source has been requested.
957 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
958 command, to allow pattern filling of memory areas.
959 ** New commands "-catch-load"/"-catch-unload" added for intercepting
960 library load/unload events.
961 ** The response to breakpoint commands and breakpoint async records
962 includes an "installed" field containing a boolean state about each
963 non-pending tracepoint location is whether installed on target or not.
964 ** Output of the "-trace-status" command includes a "trace-file" field
965 containing the name of the trace file being examined. This field is
966 optional, and only present when examining a trace file.
967 ** The "fullname" field is now always present along with the "file" field,
968 even if the file cannot be found by GDB.
970 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
971 You must have the LZMA library available when configuring GDB for this
972 feature to be enabled. For more information, see:
973 http://fedoraproject.org/wiki/Features/MiniDebugInfo
978 Set the size of trace buffer. The remote stub reports support for this
979 packet to gdb's qSupported query.
982 Enable Branch Trace Store (BTS)-based branch tracing for the current
983 thread. The remote stub reports support for this packet to gdb's
987 Disable branch tracing for the current thread. The remote stub reports
988 support for this packet to gdb's qSupported query.
991 Read the traced branches for the current thread. The remote stub
992 reports support for this packet to gdb's qSupported query.
994 *** Changes in GDB 7.5
996 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
997 for more x32 ABI info.
999 * GDB now supports access to MIPS DSP registers on Linux targets.
1001 * GDB now supports debugging microMIPS binaries.
1003 * The "info os" command on GNU/Linux can now display information on
1004 several new classes of objects managed by the operating system:
1005 "info os procgroups" lists process groups
1006 "info os files" lists file descriptors
1007 "info os sockets" lists internet-domain sockets
1008 "info os shm" lists shared-memory regions
1009 "info os semaphores" lists semaphores
1010 "info os msg" lists message queues
1011 "info os modules" lists loaded kernel modules
1013 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1014 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1015 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1016 options and inspect the probe arguments using the new $_probe_arg family
1017 of convenience variables. You can obtain more information about SystemTap
1018 in <http://sourceware.org/systemtap/>.
1020 * GDB now supports reversible debugging on ARM, it allows you to
1021 debug basic ARM and THUMB instructions, and provides
1022 record/replay support.
1024 * The option "symbol-reloading" has been deleted as it is no longer used.
1028 ** GDB commands implemented in Python can now be put in command class
1031 ** The "maint set python print-stack on|off" is now deleted.
1033 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1034 apply "flag enum"-style pretty-printing to any enum.
1036 ** gdb.lookup_symbol can now work when there is no current frame.
1038 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1039 the source at which the symbol was defined.
1041 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1042 method 'value'. The former indicates whether the symbol needs a
1043 frame in order to compute its value, and the latter computes the
1046 ** A new method 'referenced_value' on gdb.Value objects which can
1047 dereference pointer as well as C++ reference values.
1049 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1050 which return the global and static blocks (as gdb.Block objects),
1051 of the underlying symbol table, respectively.
1053 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1054 object associated with a PC value.
1056 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1057 of the address range occupied by code for the current source line.
1059 * Go language support.
1060 GDB now supports debugging programs written in the Go programming
1063 * GDBserver now supports stdio connections.
1064 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1066 * The binary "gdbtui" can no longer be built or installed.
1067 Use "gdb -tui" instead.
1069 * GDB will now print "flag" enums specially. A flag enum is one where
1070 all the enumerator values have no bits in common when pairwise
1071 "and"ed. When printing a value whose type is a flag enum, GDB will
1072 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1073 (gdb) print (enum E) 3
1076 * The filename part of a linespec will now match trailing components
1077 of a source file name. For example, "break gcc/expr.c:1000" will
1078 now set a breakpoint in build/gcc/expr.c, but not
1079 build/libcpp/expr.c.
1081 * The "info proc" and "generate-core-file" commands will now also
1082 work on remote targets connected to GDBserver on Linux.
1084 * The command "info catch" has been removed. It has been disabled
1085 since December 2007.
1087 * The "catch exception" and "catch assert" commands now accept
1088 a condition at the end of the command, much like the "break"
1089 command does. For instance:
1091 (gdb) catch exception Constraint_Error if Barrier = True
1093 Previously, it was possible to add a condition to such catchpoints,
1094 but it had to be done as a second step, after the catchpoint had been
1095 created, using the "condition" command.
1097 * The "info static-tracepoint-marker" command will now also work on
1098 native Linux targets with in-process agent.
1100 * GDB can now set breakpoints on inlined functions.
1102 * The .gdb_index section has been updated to include symbols for
1103 inlined functions. GDB will ignore older .gdb_index sections by
1104 default, which could cause symbol files to be loaded more slowly
1105 until their .gdb_index sections can be recreated. The new command
1106 "set use-deprecated-index-sections on" will cause GDB to use any older
1107 .gdb_index sections it finds. This will restore performance, but the
1108 ability to set breakpoints on inlined functions will be lost in symbol
1109 files with older .gdb_index sections.
1111 The .gdb_index section has also been updated to record more information
1112 about each symbol. This speeds up the "info variables", "info functions"
1113 and "info types" commands when used with programs having the .gdb_index
1114 section, as well as speeding up debugging with shared libraries using
1115 the .gdb_index section.
1117 * Ada support for GDB/MI Variable Objects has been added.
1119 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1124 ** New command -info-os is the MI equivalent of "info os".
1126 ** Output logs ("set logging" and related) now include MI output.
1130 ** "set use-deprecated-index-sections on|off"
1131 "show use-deprecated-index-sections on|off"
1132 Controls the use of deprecated .gdb_index sections.
1134 ** "catch load" and "catch unload" can be used to stop when a shared
1135 library is loaded or unloaded, respectively.
1137 ** "enable count" can be used to auto-disable a breakpoint after
1140 ** "info vtbl" can be used to show the virtual method tables for
1141 C++ and Java objects.
1143 ** "explore" and its sub commands "explore value" and "explore type"
1144 can be used to recursively explore values and types of
1145 expressions. These commands are available only if GDB is
1146 configured with '--with-python'.
1148 ** "info auto-load" shows status of all kinds of auto-loaded files,
1149 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1150 sequences of commands files, "info auto-load python-scripts"
1151 shows status of auto-loading Python script files,
1152 "info auto-load local-gdbinit" shows status of loading init file
1153 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1154 status of inferior specific thread debugging shared library loading.
1156 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1157 and "show auto-load-scripts" commands have been deprecated, use their
1158 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1159 and "show auto-load python-scripts" counterparts instead.
1161 ** "dprintf location,format,args..." creates a dynamic printf, which
1162 is basically a breakpoint that does a printf and immediately
1163 resumes your program's execution, so it is like a printf that you
1164 can insert dynamically at runtime instead of at compiletime.
1166 ** "set print symbol"
1168 Controls whether GDB attempts to display the symbol, if any,
1169 corresponding to addresses it prints. This defaults to "on", but
1170 you can set it to "off" to restore GDB's previous behavior.
1172 * Deprecated commands
1174 ** For the Renesas Super-H architecture, the "regs" command has been
1175 deprecated, and "info all-registers" should be used instead.
1179 Renesas RL78 rl78-*-elf
1180 HP OpenVMS ia64 ia64-hp-openvms*
1182 * GDBserver supports evaluation of breakpoint conditions. When
1183 support is advertised by GDBserver, GDB may be told to send the
1184 breakpoint conditions in bytecode form to GDBserver. GDBserver
1185 will only report the breakpoint trigger to GDB when its condition
1190 set mips compression
1191 show mips compression
1192 Select the compressed ISA encoding used in functions that have no symbol
1193 information available. The encoding can be set to either of:
1196 and is updated automatically from ELF file flags if available.
1198 set breakpoint condition-evaluation
1199 show breakpoint condition-evaluation
1200 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1201 GDBserver ("target"). Default option "auto" chooses the most efficient
1203 This option can improve debugger efficiency depending on the speed of the
1207 Disable auto-loading globally.
1210 Show auto-loading setting of all kinds of auto-loaded files.
1212 set auto-load gdb-scripts on|off
1213 show auto-load gdb-scripts
1214 Control auto-loading of GDB canned sequences of commands files.
1216 set auto-load python-scripts on|off
1217 show auto-load python-scripts
1218 Control auto-loading of Python script files.
1220 set auto-load local-gdbinit on|off
1221 show auto-load local-gdbinit
1222 Control loading of init file (.gdbinit) from current directory.
1224 set auto-load libthread-db on|off
1225 show auto-load libthread-db
1226 Control auto-loading of inferior specific thread debugging shared library.
1228 set auto-load scripts-directory <dir1>[:<dir2>...]
1229 show auto-load scripts-directory
1230 Set a list of directories from which to load auto-loaded scripts.
1231 Automatically loaded Python scripts and GDB scripts are located in one
1232 of the directories listed by this option.
1233 The delimiter (':' above) may differ according to the host platform.
1235 set auto-load safe-path <dir1>[:<dir2>...]
1236 show auto-load safe-path
1237 Set a list of directories from which it is safe to auto-load files.
1238 The delimiter (':' above) may differ according to the host platform.
1240 set debug auto-load on|off
1241 show debug auto-load
1242 Control display of debugging info for auto-loading the files above.
1244 set dprintf-style gdb|call|agent
1246 Control the way in which a dynamic printf is performed; "gdb"
1247 requests a GDB printf command, while "call" causes dprintf to call a
1248 function in the inferior. "agent" requests that the target agent
1249 (such as GDBserver) do the printing.
1251 set dprintf-function <expr>
1252 show dprintf-function
1253 set dprintf-channel <expr>
1254 show dprintf-channel
1255 Set the function and optional first argument to the call when using
1256 the "call" style of dynamic printf.
1258 set disconnected-dprintf on|off
1259 show disconnected-dprintf
1260 Control whether agent-style dynamic printfs continue to be in effect
1261 after GDB disconnects.
1263 * New configure options
1265 --with-auto-load-dir
1266 Configure default value for the 'set auto-load scripts-directory'
1267 setting above. It defaults to '$debugdir:$datadir/auto-load',
1268 $debugdir representing global debugging info directories (available
1269 via 'show debug-file-directory') and $datadir representing GDB's data
1270 directory (available via 'show data-directory').
1272 --with-auto-load-safe-path
1273 Configure default value for the 'set auto-load safe-path' setting
1274 above. It defaults to the --with-auto-load-dir setting.
1276 --without-auto-load-safe-path
1277 Set 'set auto-load safe-path' to '/', effectively disabling this
1280 * New remote packets
1282 z0/z1 conditional breakpoints extension
1284 The z0/z1 breakpoint insertion packets have been extended to carry
1285 a list of conditional expressions over to the remote stub depending on the
1286 condition evaluation mode. The use of this extension can be controlled
1287 via the "set remote conditional-breakpoints-packet" command.
1291 Specify the signals which the remote stub may pass to the debugged
1292 program without GDB involvement.
1294 * New command line options
1296 --init-command=FILE, -ix Like --command, -x but execute it
1297 before loading inferior.
1298 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1299 execute it before loading inferior.
1301 *** Changes in GDB 7.4
1303 * GDB now handles ambiguous linespecs more consistently; the existing
1304 FILE:LINE support has been expanded to other types of linespecs. A
1305 breakpoint will now be set on all matching locations in all
1306 inferiors, and locations will be added or removed according to
1309 * GDB now allows you to skip uninteresting functions and files when
1310 stepping with the "skip function" and "skip file" commands.
1312 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1313 and "show remote hardware-watchpoint-length-limit". These allows to
1314 set or show the maximum length limit (in bytes) of a remote
1315 target hardware watchpoint.
1317 This allows e.g. to use "unlimited" hardware watchpoints with the
1318 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1319 watchpoints are slower than real hardware watchpoints but are
1320 significantly faster than gdb software watchpoints.
1324 ** The register_pretty_printer function in module gdb.printing now takes
1325 an optional `replace' argument. If True, the new printer replaces any
1328 ** The "maint set python print-stack on|off" command has been
1329 deprecated and will be deleted in GDB 7.5.
1330 A new command: "set python print-stack none|full|message" has
1331 replaced it. Additionally, the default for "print-stack" is
1332 now "message", which just prints the error message without
1335 ** A prompt substitution hook (prompt_hook) is now available to the
1338 ** A new Python module, gdb.prompt has been added to the GDB Python
1339 modules library. This module provides functionality for
1340 escape sequences in prompts (used by set/show
1341 extended-prompt). These escape sequences are replaced by their
1342 corresponding value.
1344 ** Python commands and convenience-functions located in
1345 'data-directory'/python/gdb/command and
1346 'data-directory'/python/gdb/function are now automatically loaded
1349 ** Blocks now provide four new attributes. global_block and
1350 static_block will return the global and static blocks
1351 respectively. is_static and is_global are boolean attributes
1352 that indicate if the block is one of those two types.
1354 ** Symbols now provide the "type" attribute, the type of the symbol.
1356 ** The "gdb.breakpoint" function has been deprecated in favor of
1359 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1360 of a function. This class is based on the "finish" command
1361 available in the CLI.
1363 ** Type objects for struct and union types now allow access to
1364 the fields using standard Python dictionary (mapping) methods.
1365 For example, "some_type['myfield']" now works, as does
1366 "some_type.items()".
1368 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1371 ** A new function, "deep_items" has been added to the gdb.types
1372 module in the GDB Python modules library. This function returns
1373 an iterator over the fields of a struct or union type. Unlike
1374 the standard Python "iteritems" method, it will recursively traverse
1375 any anonymous fields.
1379 ** "*stopped" events can report several new "reason"s, such as
1382 ** Breakpoint changes are now notified using new async records, like
1383 "=breakpoint-modified".
1385 ** New command -ada-task-info.
1387 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1388 $sdir specifies the default system locations of shared libraries.
1389 $pdir specifies the directory where the libpthread used by the application
1392 GDB no longer looks in $sdir and $pdir after it has searched the directories
1393 mentioned in libthread-db-search-path. If you want to search those
1394 directories, they must be specified in libthread-db-search-path.
1395 The default value of libthread-db-search-path on GNU/Linux and Solaris
1396 systems is now "$sdir:$pdir".
1398 $pdir is not supported by gdbserver, it is currently ignored.
1399 $sdir is supported by gdbserver.
1401 * New configure option --with-iconv-bin.
1402 When using the internationalization support like the one in the GNU C
1403 library, GDB will invoke the "iconv" program to get a list of supported
1404 character sets. If this program lives in a non-standard location, one can
1405 use this option to specify where to find it.
1407 * When natively debugging programs on PowerPC BookE processors running
1408 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1409 watchpoints, which specify a mask in addition to an address to watch.
1410 The mask specifies that some bits of an address (the bits which are
1411 reset in the mask) should be ignored when matching the address accessed
1412 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1413 section in the user manual for more details.
1415 * The new option --once causes GDBserver to stop listening for connections once
1416 the first connection is made. The listening port used by GDBserver will
1417 become available after that.
1419 * New commands "info macros" and "alias" have been added.
1421 * New function parameters suffix @entry specifies value of function parameter
1422 at the time the function got called. Entry values are available only since
1428 "!" is now an alias of the "shell" command.
1429 Note that no space is needed between "!" and SHELL COMMAND.
1433 watch EXPRESSION mask MASK_VALUE
1434 The watch command now supports the mask argument which allows creation
1435 of masked watchpoints, if the current architecture supports this feature.
1437 info auto-load-scripts [REGEXP]
1438 This command was formerly named "maintenance print section-scripts".
1439 It is now generally useful and is no longer a maintenance-only command.
1441 info macro [-all] [--] MACRO
1442 The info macro command has new options `-all' and `--'. The first for
1443 printing all definitions of a macro. The second for explicitly specifying
1444 the end of arguments and the beginning of the macro name in case the macro
1445 name starts with a hyphen.
1447 collect[/s] EXPRESSIONS
1448 The tracepoint collect command now takes an optional modifier "/s"
1449 that directs it to dereference pointer-to-character types and
1450 collect the bytes of memory up to a zero byte. The behavior is
1451 similar to what you see when you use the regular print command on a
1452 string. An optional integer following the "/s" sets a bound on the
1453 number of bytes that will be collected.
1456 The trace start command now interprets any supplied arguments as a
1457 note to be recorded with the trace run, with an effect similar to
1458 setting the variable trace-notes.
1461 The trace stop command now interprets any arguments as a note to be
1462 mentioned along with the tstatus report that the trace was stopped
1463 with a command. The effect is similar to setting the variable
1466 * Tracepoints can now be enabled and disabled at any time after a trace
1467 experiment has been started using the standard "enable" and "disable"
1468 commands. It is now possible to start a trace experiment with no enabled
1469 tracepoints; GDB will display a warning, but will allow the experiment to
1470 begin, assuming that tracepoints will be enabled as needed while the trace
1473 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1474 locations with 4-byte instructions, when they were previously
1475 limited to locations with instructions of 5 bytes or longer.
1479 set debug dwarf2-read
1480 show debug dwarf2-read
1481 Turns on or off display of debugging messages related to reading
1482 DWARF debug info. The default is off.
1484 set debug symtab-create
1485 show debug symtab-create
1486 Turns on or off display of debugging messages related to symbol table
1487 creation. The default is off.
1490 show extended-prompt
1491 Set the GDB prompt, and allow escape sequences to be inserted to
1492 display miscellaneous information (see 'help set extended-prompt'
1493 for the list of sequences). This prompt (and any information
1494 accessed through the escape sequences) is updated every time the
1495 prompt is displayed.
1497 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1498 show print entry-values
1499 Set printing of frame argument values at function entry. In some cases
1500 GDB can determine the value of function argument which was passed by the
1501 function caller, even if the value was modified inside the called function.
1503 set debug entry-values
1504 show debug entry-values
1505 Control display of debugging info for determining frame argument values at
1506 function entry and virtual tail call frames.
1508 set basenames-may-differ
1509 show basenames-may-differ
1510 Set whether a source file may have multiple base names.
1511 (A "base name" is the name of a file with the directory part removed.
1512 Example: The base name of "/home/user/hello.c" is "hello.c".)
1513 If set, GDB will canonicalize file names (e.g., expand symlinks)
1514 before comparing them. Canonicalization is an expensive operation,
1515 but it allows the same file be known by more than one base name.
1516 If not set (the default), all source files are assumed to have just
1517 one base name, and gdb will do file name comparisons more efficiently.
1523 Set a user name and notes for the current and any future trace runs.
1524 This is useful for long-running and/or disconnected traces, to
1525 inform others (or yourself) as to who is running the trace, supply
1526 contact information, or otherwise explain what is going on.
1528 set trace-stop-notes
1529 show trace-stop-notes
1530 Set a note attached to the trace run, that is displayed when the
1531 trace has been stopped by a tstop command. This is useful for
1532 instance as an explanation, if you are stopping a trace run that was
1533 started by someone else.
1535 * New remote packets
1539 Dynamically enable a tracepoint in a started trace experiment.
1543 Dynamically disable a tracepoint in a started trace experiment.
1547 Set the user and notes of the trace run.
1551 Query the current status of a tracepoint.
1555 Query the minimum length of instruction at which a fast tracepoint may
1558 * Dcache size (number of lines) and line-size are now runtime-configurable
1559 via "set dcache line" and "set dcache line-size" commands.
1563 Texas Instruments TMS320C6x tic6x-*-*
1567 Renesas RL78 rl78-*-elf
1569 *** Changes in GDB 7.3.1
1571 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1573 *** Changes in GDB 7.3
1575 * GDB has a new command: "thread find [REGEXP]".
1576 It finds the thread id whose name, target id, or thread extra info
1577 matches the given regular expression.
1579 * The "catch syscall" command now works on mips*-linux* targets.
1581 * The -data-disassemble MI command now supports modes 2 and 3 for
1582 dumping the instruction opcodes.
1584 * New command line options
1586 -data-directory DIR Specify DIR as the "data-directory".
1587 This is mostly for testing purposes.
1589 * The "maint set python auto-load on|off" command has been renamed to
1590 "set auto-load-scripts on|off".
1592 * GDB has a new command: "set directories".
1593 It is like the "dir" command except that it replaces the
1594 source path list instead of augmenting it.
1596 * GDB now understands thread names.
1598 On GNU/Linux, "info threads" will display the thread name as set by
1599 prctl or pthread_setname_np.
1601 There is also a new command, "thread name", which can be used to
1602 assign a name internally for GDB to display.
1605 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1606 has been integrated into GDB.
1610 ** The function gdb.Write now accepts an optional keyword 'stream'.
1611 This keyword, when provided, will direct the output to either
1612 stdout, stderr, or GDB's logging output.
1614 ** Parameters can now be be sub-classed in Python, and in particular
1615 you may implement the get_set_doc and get_show_doc functions.
1616 This improves how Parameter set/show documentation is processed
1617 and allows for more dynamic content.
1619 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1620 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1621 have an is_valid method.
1623 ** Breakpoints can now be sub-classed in Python, and in particular
1624 you may implement a 'stop' function that is executed each time
1625 the inferior reaches that breakpoint.
1627 ** New function gdb.lookup_global_symbol looks up a global symbol.
1629 ** GDB values in Python are now callable if the value represents a
1630 function. For example, if 'some_value' represents a function that
1631 takes two integer parameters and returns a value, you can call
1632 that function like so:
1634 result = some_value (10,20)
1636 ** Module gdb.types has been added.
1637 It contains a collection of utilities for working with gdb.Types objects:
1638 get_basic_type, has_field, make_enum_dict.
1640 ** Module gdb.printing has been added.
1641 It contains utilities for writing and registering pretty-printers.
1642 New classes: PrettyPrinter, SubPrettyPrinter,
1643 RegexpCollectionPrettyPrinter.
1644 New function: register_pretty_printer.
1646 ** New commands "info pretty-printers", "enable pretty-printer" and
1647 "disable pretty-printer" have been added.
1649 ** gdb.parameter("directories") is now available.
1651 ** New function gdb.newest_frame returns the newest frame in the
1654 ** The gdb.InferiorThread class has a new "name" attribute. This
1655 holds the thread's name.
1657 ** Python Support for Inferior events.
1658 Python scripts can add observers to be notified of events
1659 occurring in the process being debugged.
1660 The following events are currently supported:
1661 - gdb.events.cont Continue event.
1662 - gdb.events.exited Inferior exited event.
1663 - gdb.events.stop Signal received, and Breakpoint hit events.
1667 ** GDB now puts template parameters in scope when debugging in an
1668 instantiation. For example, if you have:
1670 template<int X> int func (void) { return X; }
1672 then if you step into func<5>, "print X" will show "5". This
1673 feature requires proper debuginfo support from the compiler; it
1674 was added to GCC 4.5.
1676 ** The motion commands "next", "finish", "until", and "advance" now
1677 work better when exceptions are thrown. In particular, GDB will
1678 no longer lose control of the inferior; instead, the GDB will
1679 stop the inferior at the point at which the exception is caught.
1680 This functionality requires a change in the exception handling
1681 code that was introduced in GCC 4.5.
1683 * GDB now follows GCC's rules on accessing volatile objects when
1684 reading or writing target state during expression evaluation.
1685 One notable difference to prior behavior is that "print x = 0"
1686 no longer generates a read of x; the value of the assignment is
1687 now always taken directly from the value being assigned.
1689 * GDB now has some support for using labels in the program's source in
1690 linespecs. For instance, you can use "advance label" to continue
1691 execution to a label.
1693 * GDB now has support for reading and writing a new .gdb_index
1694 section. This section holds a fast index of DWARF debugging
1695 information and can be used to greatly speed up GDB startup and
1696 operation. See the documentation for `save gdb-index' for details.
1698 * The "watch" command now accepts an optional "-location" argument.
1699 When used, this causes GDB to watch the memory referred to by the
1700 expression. Such a watchpoint is never deleted due to it going out
1703 * GDB now supports thread debugging of core dumps on GNU/Linux.
1705 GDB now activates thread debugging using the libthread_db library
1706 when debugging GNU/Linux core dumps, similarly to when debugging
1707 live processes. As a result, when debugging a core dump file, GDB
1708 is now able to display pthread_t ids of threads. For example, "info
1709 threads" shows the same output as when debugging the process when it
1710 was live. In earlier releases, you'd see something like this:
1713 * 1 LWP 6780 main () at main.c:10
1715 While now you see this:
1718 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1720 It is also now possible to inspect TLS variables when debugging core
1723 When debugging a core dump generated on a machine other than the one
1724 used to run GDB, you may need to point GDB at the correct
1725 libthread_db library with the "set libthread-db-search-path"
1726 command. See the user manual for more details on this command.
1728 * When natively debugging programs on PowerPC BookE processors running
1729 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1730 which stop execution of the inferior whenever it executes an instruction
1731 at any address within the specified range. See the "PowerPC Embedded"
1732 section in the user manual for more details.
1734 * New features in the GDB remote stub, GDBserver
1736 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1737 and i686 LynxOS (version 5.x).
1739 ** GDBserver is now supported on Blackfin Linux.
1741 * New native configurations
1743 ia64 HP-UX ia64-*-hpux*
1747 Analog Devices, Inc. Blackfin Processor bfin-*
1749 * Ada task switching is now supported on sparc-elf targets when
1750 debugging a program using the Ravenscar Profile. For more information,
1751 see the "Tasking Support when using the Ravenscar Profile" section
1752 in the GDB user manual.
1754 * Guile support was removed.
1756 * New features in the GNU simulator
1758 ** The --map-info flag lists all known core mappings.
1760 ** CFI flashes may be simulated via the "cfi" device.
1762 *** Changes in GDB 7.2
1764 * Shared library support for remote targets by default
1766 When GDB is configured for a generic, non-OS specific target, like
1767 for example, --target=arm-eabi or one of the many *-*-elf targets,
1768 GDB now queries remote stubs for loaded shared libraries using the
1769 `qXfer:libraries:read' packet. Previously, shared library support
1770 was always disabled for such configurations.
1774 ** Argument Dependent Lookup (ADL)
1776 In C++ ADL lookup directs function search to the namespaces of its
1777 arguments even if the namespace has not been imported.
1787 Here the compiler will search for `foo' in the namespace of 'b'
1788 and find A::foo. GDB now supports this. This construct is commonly
1789 used in the Standard Template Library for operators.
1791 ** Improved User Defined Operator Support
1793 In addition to member operators, GDB now supports lookup of operators
1794 defined in a namespace and imported with a `using' directive, operators
1795 defined in the global scope, operators imported implicitly from an
1796 anonymous namespace, and the ADL operators mentioned in the previous
1798 GDB now also supports proper overload resolution for all the previously
1799 mentioned flavors of operators.
1801 ** static const class members
1803 Printing of static const class members that are initialized in the
1804 class definition has been fixed.
1806 * Windows Thread Information Block access.
1808 On Windows targets, GDB now supports displaying the Windows Thread
1809 Information Block (TIB) structure. This structure is visible either
1810 by using the new command `info w32 thread-information-block' or, by
1811 dereferencing the new convenience variable named `$_tlb', a
1812 thread-specific pointer to the TIB. This feature is also supported
1813 when remote debugging using GDBserver.
1815 * Static tracepoints
1817 Static tracepoints are calls in the user program into a tracing
1818 library. One such library is a port of the LTTng kernel tracer to
1819 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1820 When debugging with GDBserver, GDB now supports combining the GDB
1821 tracepoint machinery with such libraries. For example: the user can
1822 use GDB to probe a static tracepoint marker (a call from the user
1823 program into the tracing library) with the new "strace" command (see
1824 "New commands" below). This creates a "static tracepoint" in the
1825 breakpoint list, that can be manipulated with the same feature set
1826 as fast and regular tracepoints. E.g., collect registers, local and
1827 global variables, collect trace state variables, and define
1828 tracepoint conditions. In addition, the user can collect extra
1829 static tracepoint marker specific data, by collecting the new
1830 $_sdata internal variable. When analyzing the trace buffer, you can
1831 inspect $_sdata like any other variable available to GDB. For more
1832 information, see the "Tracepoints" chapter in GDB user manual. New
1833 remote packets have been defined to support static tracepoints, see
1834 the "New remote packets" section below.
1836 * Better reconstruction of tracepoints after disconnected tracing
1838 GDB will attempt to download the original source form of tracepoint
1839 definitions when starting a trace run, and then will upload these
1840 upon reconnection to the target, resulting in a more accurate
1841 reconstruction of the tracepoints that are in use on the target.
1845 You can now exercise direct control over the ways that GDB can
1846 affect your program. For instance, you can disallow the setting of
1847 breakpoints, so that the program can run continuously (assuming
1848 non-stop mode). In addition, the "observer" variable is available
1849 to switch all of the different controls; in observer mode, GDB
1850 cannot affect the target's behavior at all, which is useful for
1851 tasks like diagnosing live systems in the field.
1853 * The new convenience variable $_thread holds the number of the
1856 * New remote packets
1860 Return the address of the Windows Thread Information Block of a given thread.
1864 In response to several of the tracepoint packets, the target may now
1865 also respond with a number of intermediate `qRelocInsn' request
1866 packets before the final result packet, to have GDB handle
1867 relocating an instruction to execute at a different address. This
1868 is particularly useful for stubs that support fast tracepoints. GDB
1869 reports support for this feature in the qSupported packet.
1873 List static tracepoint markers in the target program.
1877 List static tracepoint markers at a given address in the target
1880 qXfer:statictrace:read
1882 Read the static trace data collected (by a `collect $_sdata'
1883 tracepoint action). The remote stub reports support for this packet
1884 to gdb's qSupported query.
1888 Send the current settings of GDB's permission flags.
1892 Send part of the source (textual) form of a tracepoint definition,
1893 which includes location, conditional, and action list.
1895 * The source command now accepts a -s option to force searching for the
1896 script in the source search path even if the script name specifies
1899 * New features in the GDB remote stub, GDBserver
1901 - GDBserver now support tracepoints (including fast tracepoints, and
1902 static tracepoints). The feature is currently supported by the
1903 i386-linux and amd64-linux builds. See the "Tracepoints support
1904 in gdbserver" section in the manual for more information.
1906 GDBserver JIT compiles the tracepoint's conditional agent
1907 expression bytecode into native code whenever possible for low
1908 overhead dynamic tracepoints conditionals. For such tracepoints,
1909 an expression that examines program state is evaluated when the
1910 tracepoint is reached, in order to determine whether to capture
1911 trace data. If the condition is simple and false, processing the
1912 tracepoint finishes very quickly and no data is gathered.
1914 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1915 for static tracepoints support.
1917 - GDBserver now supports x86_64 Windows 64-bit debugging.
1919 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1920 it understands register description.
1922 * The --batch flag now disables pagination and queries.
1924 * X86 general purpose registers
1926 GDB now supports reading/writing byte, word and double-word x86
1927 general purpose registers directly. This means you can use, say,
1928 $ah or $ax to refer, respectively, to the byte register AH and
1929 16-bit word register AX that are actually portions of the 32-bit
1930 register EAX or 64-bit register RAX.
1932 * The `commands' command now accepts a range of breakpoints to modify.
1933 A plain `commands' following a command that creates multiple
1934 breakpoints affects all the breakpoints set by that command. This
1935 applies to breakpoints set by `rbreak', and also applies when a
1936 single `break' command creates multiple breakpoints (e.g.,
1937 breakpoints on overloaded c++ functions).
1939 * The `rbreak' command now accepts a filename specification as part of
1940 its argument, limiting the functions selected by the regex to those
1941 in the specified file.
1943 * Support for remote debugging Windows and SymbianOS shared libraries
1944 from Unix hosts has been improved. Non Windows GDB builds now can
1945 understand target reported file names that follow MS-DOS based file
1946 system semantics, such as file names that include drive letters and
1947 use the backslash character as directory separator. This makes it
1948 possible to transparently use the "set sysroot" and "set
1949 solib-search-path" on Unix hosts to point as host copies of the
1950 target's shared libraries. See the new command "set
1951 target-file-system-kind" described below, and the "Commands to
1952 specify files" section in the user manual for more information.
1956 eval template, expressions...
1957 Convert the values of one or more expressions under the control
1958 of the string template to a command line, and call it.
1960 set target-file-system-kind unix|dos-based|auto
1961 show target-file-system-kind
1962 Set or show the assumed file system kind for target reported file
1965 save breakpoints <filename>
1966 Save all current breakpoint definitions to a file suitable for use
1967 in a later debugging session. To read the saved breakpoint
1968 definitions, use the `source' command.
1970 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1973 info static-tracepoint-markers
1974 Display information about static tracepoint markers in the target.
1976 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1977 Define a static tracepoint by probing a marker at the given
1978 function, line, address, or marker ID.
1982 Enable and disable observer mode.
1984 set may-write-registers on|off
1985 set may-write-memory on|off
1986 set may-insert-breakpoints on|off
1987 set may-insert-tracepoints on|off
1988 set may-insert-fast-tracepoints on|off
1989 set may-interrupt on|off
1990 Set individual permissions for GDB effects on the target. Note that
1991 some of these settings can have undesirable or surprising
1992 consequences, particularly when changed in the middle of a session.
1993 For instance, disabling the writing of memory can prevent
1994 breakpoints from being inserted, cause single-stepping to fail, or
1995 even crash your program, if you disable after breakpoints have been
1996 inserted. However, GDB should not crash.
1998 set record memory-query on|off
1999 show record memory-query
2000 Control whether to stop the inferior if memory changes caused
2001 by an instruction cannot be recorded.
2006 The disassemble command now supports "start,+length" form of two arguments.
2010 ** GDB now provides a new directory location, called the python directory,
2011 where Python scripts written for GDB can be installed. The location
2012 of that directory is <data-directory>/python, where <data-directory>
2013 is the GDB data directory. For more details, see section `Scripting
2014 GDB using Python' in the manual.
2016 ** The GDB Python API now has access to breakpoints, symbols, symbol
2017 tables, program spaces, inferiors, threads and frame's code blocks.
2018 Additionally, GDB Parameters can now be created from the API, and
2019 manipulated via set/show in the CLI.
2021 ** New functions gdb.target_charset, gdb.target_wide_charset,
2022 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2024 ** New exception gdb.GdbError.
2026 ** Pretty-printers are now also looked up in the current program space.
2028 ** Pretty-printers can now be individually enabled and disabled.
2030 ** GDB now looks for names of Python scripts to auto-load in a
2031 special section named `.debug_gdb_scripts', in addition to looking
2032 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2034 * Tracepoint actions were unified with breakpoint commands. In particular,
2035 there are no longer differences in "info break" output for breakpoints and
2036 tracepoints and the "commands" command can be used for both tracepoints and
2037 regular breakpoints.
2041 ARM Symbian arm*-*-symbianelf*
2043 * D language support.
2044 GDB now supports debugging programs written in the D programming
2047 * GDB now supports the extended ptrace interface for PowerPC which is
2048 available since Linux kernel version 2.6.34. This automatically enables
2049 any hardware breakpoints and additional hardware watchpoints available in
2050 the processor. The old ptrace interface exposes just one hardware
2051 watchpoint and no hardware breakpoints.
2053 * GDB is now able to use the Data Value Compare (DVC) register available on
2054 embedded PowerPC processors to implement in hardware simple watchpoint
2055 conditions of the form:
2057 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2059 This works in native GDB running on Linux kernels with the extended ptrace
2060 interface mentioned above.
2062 *** Changes in GDB 7.1
2066 ** Namespace Support
2068 GDB now supports importing of namespaces in C++. This enables the
2069 user to inspect variables from imported namespaces. Support for
2070 namepace aliasing has also been added. So, if a namespace is
2071 aliased in the current scope (e.g. namepace C=A; ) the user can
2072 print variables using the alias (e.g. (gdb) print C::x).
2076 All known bugs relating to the printing of virtual base class were
2077 fixed. It is now possible to call overloaded static methods using a
2082 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2083 and reinterpret_cast<> are now handled by the C++ expression parser.
2087 Xilinx MicroBlaze microblaze-*-*
2092 Xilinx MicroBlaze microblaze
2095 * Multi-program debugging.
2097 GDB now has support for multi-program (a.k.a. multi-executable or
2098 multi-exec) debugging. This allows for debugging multiple inferiors
2099 simultaneously each running a different program under the same GDB
2100 session. See "Debugging Multiple Inferiors and Programs" in the
2101 manual for more information. This implied some user visible changes
2102 in the multi-inferior support. For example, "info inferiors" now
2103 lists inferiors that are not running yet or that have exited
2104 already. See also "New commands" and "New options" below.
2106 * New tracing features
2108 GDB's tracepoint facility now includes several new features:
2110 ** Trace state variables
2112 GDB tracepoints now include support for trace state variables, which
2113 are variables managed by the target agent during a tracing
2114 experiment. They are useful for tracepoints that trigger each
2115 other, so for instance one tracepoint can count hits in a variable,
2116 and then a second tracepoint has a condition that is true when the
2117 count reaches a particular value. Trace state variables share the
2118 $-syntax of GDB convenience variables, and can appear in both
2119 tracepoint actions and condition expressions. Use the "tvariable"
2120 command to create, and "info tvariables" to view; see "Trace State
2121 Variables" in the manual for more detail.
2125 GDB now includes an option for defining fast tracepoints, which
2126 targets may implement more efficiently, such as by installing a jump
2127 into the target agent rather than a trap instruction. The resulting
2128 speedup can be by two orders of magnitude or more, although the
2129 tradeoff is that some program locations on some target architectures
2130 might not allow fast tracepoint installation, for instance if the
2131 instruction to be replaced is shorter than the jump. To request a
2132 fast tracepoint, use the "ftrace" command, with syntax identical to
2133 the regular trace command.
2135 ** Disconnected tracing
2137 It is now possible to detach GDB from the target while it is running
2138 a trace experiment, then reconnect later to see how the experiment
2139 is going. In addition, a new variable disconnected-tracing lets you
2140 tell the target agent whether to continue running a trace if the
2141 connection is lost unexpectedly.
2145 GDB now has the ability to save the trace buffer into a file, and
2146 then use that file as a target, similarly to you can do with
2147 corefiles. You can select trace frames, print data that was
2148 collected in them, and use tstatus to display the state of the
2149 tracing run at the moment that it was saved. To create a trace
2150 file, use "tsave <filename>", and to use it, do "target tfile
2153 ** Circular trace buffer
2155 You can ask the target agent to handle the trace buffer as a
2156 circular buffer, discarding the oldest trace frames to make room for
2157 newer ones, by setting circular-trace-buffer to on. This feature may
2158 not be available for all target agents.
2163 The disassemble command, when invoked with two arguments, now requires
2164 the arguments to be comma-separated.
2167 The info variables command now displays variable definitions. Files
2168 which only declare a variable are not shown.
2171 The source command is now capable of sourcing Python scripts.
2172 This feature is dependent on the debugger being build with Python
2175 Related to this enhancement is also the introduction of a new command
2176 "set script-extension" (see below).
2178 * New commands (for set/show, see "New options" below)
2180 record save [<FILENAME>]
2181 Save a file (in core file format) containing the process record
2182 execution log for replay debugging at a later time.
2184 record restore <FILENAME>
2185 Restore the process record execution log that was saved at an
2186 earlier time, for replay debugging.
2188 add-inferior [-copies <N>] [-exec <FILENAME>]
2191 clone-inferior [-copies <N>] [ID]
2192 Make a new inferior ready to execute the same program another
2193 inferior has loaded.
2198 maint info program-spaces
2199 List the program spaces loaded into GDB.
2201 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2202 show remote interrupt-sequence
2203 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2204 as the sequence to the remote target in order to interrupt the execution.
2205 Ctrl-C is a default. Some system prefers BREAK which is high level of
2206 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2207 Magic SysRq g. It is BREAK signal and character 'g'.
2209 set remote interrupt-on-connect [on | off]
2210 show remote interrupt-on-connect
2211 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2212 remote target when gdb connects to it. This is needed when you debug
2215 set remotebreak [on | off]
2217 Deprecated. Use "set/show remote interrupt-sequence" instead.
2219 tvariable $NAME [ = EXP ]
2220 Create or modify a trace state variable.
2223 List trace state variables and their values.
2225 delete tvariable $NAME ...
2226 Delete one or more trace state variables.
2229 Evaluate the given expressions without collecting anything into the
2230 trace buffer. (Valid in tracepoint actions only.)
2232 ftrace FN / FILE:LINE / *ADDR
2233 Define a fast tracepoint at the given function, line, or address.
2235 * New expression syntax
2237 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2238 GDB now parses 0b101010 identically with 42.
2242 set follow-exec-mode new|same
2243 show follow-exec-mode
2244 Control whether GDB reuses the same inferior across an exec call or
2245 creates a new one. This is useful to be able to restart the old
2246 executable after the inferior having done an exec call.
2248 set default-collect EXPR, ...
2249 show default-collect
2250 Define a list of expressions to be collected at each tracepoint.
2251 This is a useful way to ensure essential items are not overlooked,
2252 such as registers or a critical global variable.
2254 set disconnected-tracing
2255 show disconnected-tracing
2256 If set to 1, the target is instructed to continue tracing if it
2257 loses its connection to GDB. If 0, the target is to stop tracing
2260 set circular-trace-buffer
2261 show circular-trace-buffer
2262 If set to on, the target is instructed to use a circular trace buffer
2263 and discard the oldest trace frames instead of stopping the trace due
2264 to a full trace buffer. If set to off, the trace stops when the buffer
2265 fills up. Some targets may not support this.
2267 set script-extension off|soft|strict
2268 show script-extension
2269 If set to "off", the debugger does not perform any script language
2270 recognition, and all sourced files are assumed to be GDB scripts.
2271 If set to "soft" (the default), files are sourced according to
2272 filename extension, falling back to GDB scripts if the first
2274 If set to "strict", files are sourced according to filename extension.
2276 set ada trust-PAD-over-XVS on|off
2277 show ada trust-PAD-over-XVS
2278 If off, activate a workaround against a bug in the debugging information
2279 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2280 the GCC sources for more information about the GNAT encoding and
2281 PAD types in particular). It is always safe to set this option to
2282 off, but this introduces a slight performance penalty. The default
2285 * Python API Improvements
2287 ** GDB provides the new class gdb.LazyString. This is useful in
2288 some pretty-printing cases. The new method gdb.Value.lazy_string
2289 provides a simple way to create objects of this type.
2291 ** The fields returned by gdb.Type.fields now have an
2292 `is_base_class' attribute.
2294 ** The new method gdb.Type.range returns the range of an array type.
2296 ** The new method gdb.parse_and_eval can be used to parse and
2297 evaluate an expression.
2299 * New remote packets
2302 Define a trace state variable.
2305 Get the current value of a trace state variable.
2308 Set desired tracing behavior upon disconnection.
2311 Set the trace buffer to be linear or circular.
2314 Get data about the tracepoints currently in use.
2318 Process record now works correctly with hardware watchpoints.
2320 Multiple bug fixes have been made to the mips-irix port, making it
2321 much more reliable. In particular:
2322 - Debugging threaded applications is now possible again. Previously,
2323 GDB would hang while starting the program, or while waiting for
2324 the program to stop at a breakpoint.
2325 - Attaching to a running process no longer hangs.
2326 - An error occurring while loading a core file has been fixed.
2327 - Changing the value of the PC register now works again. This fixes
2328 problems observed when using the "jump" command, or when calling
2329 a function from GDB, or even when assigning a new value to $pc.
2330 - With the "finish" and "return" commands, the return value for functions
2331 returning a small array is now correctly printed.
2332 - It is now possible to break on shared library code which gets executed
2333 during a shared library init phase (code executed while executing
2334 their .init section). Previously, the breakpoint would have no effect.
2335 - GDB is now able to backtrace through the signal handler for
2336 non-threaded programs.
2338 PIE (Position Independent Executable) programs debugging is now supported.
2339 This includes debugging execution of PIC (Position Independent Code) shared
2340 libraries although for that, it should be possible to run such libraries as an
2343 *** Changes in GDB 7.0
2345 * GDB now has an interface for JIT compilation. Applications that
2346 dynamically generate code can create symbol files in memory and register
2347 them with GDB. For users, the feature should work transparently, and
2348 for JIT developers, the interface is documented in the GDB manual in the
2349 "JIT Compilation Interface" chapter.
2351 * Tracepoints may now be conditional. The syntax is as for
2352 breakpoints; either an "if" clause appended to the "trace" command,
2353 or the "condition" command is available. GDB sends the condition to
2354 the target for evaluation using the same bytecode format as is used
2355 for tracepoint actions.
2357 * The disassemble command now supports: an optional /r modifier, print the
2358 raw instructions in hex as well as in symbolic form, and an optional /m
2359 modifier to print mixed source+assembly.
2361 * Process record and replay
2363 In a architecture environment that supports ``process record and
2364 replay'', ``process record and replay'' target can record a log of
2365 the process execution, and replay it with both forward and reverse
2368 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2369 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2370 set execution-direction {forward|reverse}, for targets that support
2373 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2374 feature is available with a native GDB running on kernel version
2377 * GDB now has support for multi-byte and wide character sets on the
2378 target. Strings whose character type is wchar_t, char16_t, or
2379 char32_t are now correctly printed. GDB supports wide- and unicode-
2380 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2381 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2382 `printf'. This feature requires iconv to work properly; if your
2383 system does not have a working iconv, GDB can use GNU libiconv. See
2384 the installation instructions for more information.
2386 * GDB now supports automatic retrieval of shared library files from
2387 remote targets. To use this feature, specify a system root that begins
2388 with the `remote:' prefix, either via the `set sysroot' command or via
2389 the `--with-sysroot' configure-time option.
2391 * "info sharedlibrary" now takes an optional regex of libraries to show,
2392 and it now reports if a shared library has no debugging information.
2394 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2395 now complete on file names.
2397 * When completing in expressions, gdb will attempt to limit
2398 completions to allowable structure or union fields, where appropriate.
2399 For instance, consider:
2401 # struct example { int f1; double f2; };
2402 # struct example variable;
2405 If the user types TAB at the end of this command line, the available
2406 completions will be "f1" and "f2".
2408 * Inlined functions are now supported. They show up in backtraces, and
2409 the "step", "next", and "finish" commands handle them automatically.
2411 * GDB now supports the token-splicing (##) and stringification (#)
2412 operators when expanding macros. It also supports variable-arity
2415 * GDB now supports inspecting extra signal information, exported by
2416 the new $_siginfo convenience variable. The feature is currently
2417 implemented on linux ARM, i386 and amd64.
2419 * GDB can now display the VFP floating point registers and NEON vector
2420 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2421 can provide these registers (requires Linux 2.6.30 or later). Remote
2422 and simulator targets may also provide them.
2424 * New remote packets
2427 Search memory for a sequence of bytes.
2430 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2431 operation over reliable transport links. Use of this packet is
2432 controlled by the `set remote noack-packet' command.
2435 Kill the process with the specified process ID. Use this in preference
2436 to `k' when multiprocess protocol extensions are supported.
2439 Obtains additional operating system information
2443 Read or write additional signal information.
2445 * Removed remote protocol undocumented extension
2447 An undocumented extension to the remote protocol's `S' stop reply
2448 packet that permited the stub to pass a process id was removed.
2449 Remote servers should use the `T' stop reply packet instead.
2451 * GDB now supports multiple function calling conventions according to the
2452 DWARF-2 DW_AT_calling_convention function attribute.
2454 * The SH target utilizes the aforementioned change to distinguish between gcc
2455 and Renesas calling convention. It also adds the new CLI commands
2456 `set/show sh calling-convention'.
2458 * GDB can now read compressed debug sections, as produced by GNU gold
2459 with the --compress-debug-sections=zlib flag.
2461 * 64-bit core files are now supported on AIX.
2463 * Thread switching is now supported on Tru64.
2465 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2466 which will be allocated using malloc later in program execution.
2468 * The qXfer:libraries:read remote procotol packet now allows passing a
2469 list of section offsets.
2471 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2472 conditions handling signals delivered during attach or thread creation
2473 have also been fixed.
2475 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2476 From the user's standpoint, all unqualified instances of True and False
2477 are treated as the standard definitions, regardless of context.
2479 * GDB now parses C++ symbol and type names more flexibly. For
2482 template<typename T> class C { };
2485 GDB will now correctly handle all of:
2487 ptype C<char const *>
2488 ptype C<char const*>
2489 ptype C<const char *>
2490 ptype C<const char*>
2492 * New features in the GDB remote stub, gdbserver
2494 - The "--wrapper" command-line argument tells gdbserver to use a
2495 wrapper program to launch programs for debugging.
2497 - On PowerPC and S/390 targets, it is now possible to use a single
2498 gdbserver executable to debug both 32-bit and 64-bit programs.
2499 (This requires gdbserver itself to be built as a 64-bit executable.)
2501 - gdbserver uses the new noack protocol mode for TCP connections to
2502 reduce communications latency, if also supported and enabled in GDB.
2504 - Support for the sparc64-linux-gnu target is now included in
2507 - The amd64-linux build of gdbserver now supports debugging both
2508 32-bit and 64-bit programs.
2510 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2511 now support hardware watchpoints, and will use them automatically
2516 GDB now has support for scripting using Python. Whether this is
2517 available is determined at configure time.
2519 New GDB commands can now be written in Python.
2521 * Ada tasking support
2523 Ada tasks can now be inspected in GDB. The following commands have
2527 Print the list of Ada tasks.
2529 Print detailed information about task number N.
2531 Print the task number of the current task.
2533 Switch the context of debugging to task number N.
2535 * Support for user-defined prefixed commands. The "define" command can
2536 add new commands to existing prefixes, e.g. "target".
2538 * Multi-inferior, multi-process debugging.
2540 GDB now has generalized support for multi-inferior debugging. See
2541 "Debugging Multiple Inferiors" in the manual for more information.
2542 Although availability still depends on target support, the command
2543 set is more uniform now. The GNU/Linux specific multi-forks support
2544 has been migrated to this new framework. This implied some user
2545 visible changes; see "New commands" and also "Removed commands"
2548 * Target descriptions can now describe the target OS ABI. See the
2549 "Target Description Format" section in the user manual for more
2552 * Target descriptions can now describe "compatible" architectures
2553 to indicate that the target can execute applications for a different
2554 architecture in addition to those for the main target architecture.
2555 See the "Target Description Format" section in the user manual for
2558 * Multi-architecture debugging.
2560 GDB now includes general supports for debugging applications on
2561 hybrid systems that use more than one single processor architecture
2562 at the same time. Each such hybrid architecture still requires
2563 specific support to be added. The only hybrid architecture supported
2564 in this version of GDB is the Cell Broadband Engine.
2566 * GDB now supports integrated debugging of Cell/B.E. applications that
2567 use both the PPU and SPU architectures. To enable support for hybrid
2568 Cell/B.E. debugging, you need to configure GDB to support both the
2569 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2570 --enable-targets configure option.
2572 * Non-stop mode debugging.
2574 For some targets, GDB now supports an optional mode of operation in
2575 which you can examine stopped threads while other threads continue
2576 to execute freely. This is referred to as non-stop mode, with the
2577 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2578 section in the user manual for more information.
2580 To be able to support remote non-stop debugging, a remote stub needs
2581 to implement the non-stop mode remote protocol extensions, as
2582 described in the "Remote Non-Stop" section of the user manual. The
2583 GDB remote stub, gdbserver, has been adjusted to support these
2584 extensions on linux targets.
2586 * New commands (for set/show, see "New options" below)
2588 catch syscall [NAME(S) | NUMBER(S)]
2589 Catch system calls. Arguments, which should be names of system
2590 calls or their numbers, mean catch only those syscalls. Without
2591 arguments, every syscall will be caught. When the inferior issues
2592 any of the specified syscalls, GDB will stop and announce the system
2593 call, both when it is called and when its call returns. This
2594 feature is currently available with a native GDB running on the
2595 Linux Kernel, under the following architectures: x86, x86_64,
2596 PowerPC and PowerPC64.
2598 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2600 Search memory for a sequence of bytes.
2602 maint set python print-stack
2603 maint show python print-stack
2604 Show a stack trace when an error is encountered in a Python script.
2607 Invoke CODE by passing it to the Python interpreter.
2612 These allow macros to be defined, undefined, and listed
2616 Show operating system information about processes.
2619 List the inferiors currently under GDB's control.
2622 Switch focus to inferior number NUM.
2625 Detach from inferior number NUM.
2628 Kill inferior number NUM.
2632 set spu stop-on-load
2633 show spu stop-on-load
2634 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2636 set spu auto-flush-cache
2637 show spu auto-flush-cache
2638 Control whether to automatically flush the software-managed cache
2639 during Cell/B.E. debugging.
2641 set sh calling-convention
2642 show sh calling-convention
2643 Control the calling convention used when calling SH target functions.
2646 show debug timestamp
2647 Control display of timestamps with GDB debugging output.
2649 set disassemble-next-line
2650 show disassemble-next-line
2651 Control display of disassembled source lines or instructions when
2654 set remote noack-packet
2655 show remote noack-packet
2656 Set/show the use of remote protocol QStartNoAckMode packet. See above
2657 under "New remote packets."
2659 set remote query-attached-packet
2660 show remote query-attached-packet
2661 Control use of remote protocol `qAttached' (query-attached) packet.
2663 set remote read-siginfo-object
2664 show remote read-siginfo-object
2665 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2668 set remote write-siginfo-object
2669 show remote write-siginfo-object
2670 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2673 set remote reverse-continue
2674 show remote reverse-continue
2675 Control use of remote protocol 'bc' (reverse-continue) packet.
2677 set remote reverse-step
2678 show remote reverse-step
2679 Control use of remote protocol 'bs' (reverse-step) packet.
2681 set displaced-stepping
2682 show displaced-stepping
2683 Control displaced stepping mode. Displaced stepping is a way to
2684 single-step over breakpoints without removing them from the debuggee.
2685 Also known as "out-of-line single-stepping".
2688 show debug displaced
2689 Control display of debugging info for displaced stepping.
2691 maint set internal-error
2692 maint show internal-error
2693 Control what GDB does when an internal error is detected.
2695 maint set internal-warning
2696 maint show internal-warning
2697 Control what GDB does when an internal warning is detected.
2702 Use a wrapper program to launch programs for debugging.
2704 set multiple-symbols (all|ask|cancel)
2705 show multiple-symbols
2706 The value of this variable can be changed to adjust the debugger behavior
2707 when an expression or a breakpoint location contains an ambiguous symbol
2708 name (an overloaded function name, for instance).
2710 set breakpoint always-inserted
2711 show breakpoint always-inserted
2712 Keep breakpoints always inserted in the target, as opposed to inserting
2713 them when resuming the target, and removing them when the target stops.
2714 This option can improve debugger performance on slow remote targets.
2716 set arm fallback-mode (arm|thumb|auto)
2717 show arm fallback-mode
2718 set arm force-mode (arm|thumb|auto)
2720 These commands control how ARM GDB determines whether instructions
2721 are ARM or Thumb. The default for both settings is auto, which uses
2722 the current CPSR value for instructions without symbols; previous
2723 versions of GDB behaved as if "set arm fallback-mode arm".
2725 set disable-randomization
2726 show disable-randomization
2727 Standalone programs run with the virtual address space randomization enabled
2728 by default on some platforms. This option keeps the addresses stable across
2729 multiple debugging sessions.
2733 Control whether other threads are stopped or not when some thread hits
2738 Requests that asynchronous execution is enabled in the target, if available.
2739 In this case, it's possible to resume target in the background, and interact
2740 with GDB while the target is running. "show target-async" displays the
2741 current state of asynchronous execution of the target.
2743 set target-wide-charset
2744 show target-wide-charset
2745 The target-wide-charset is the name of the character set that GDB
2746 uses when printing characters whose type is wchar_t.
2748 set tcp auto-retry (on|off)
2750 set tcp connect-timeout
2751 show tcp connect-timeout
2752 These commands allow GDB to retry failed TCP connections to a remote stub
2753 with a specified timeout period; this is useful if the stub is launched
2754 in parallel with GDB but may not be ready to accept connections immediately.
2756 set libthread-db-search-path
2757 show libthread-db-search-path
2758 Control list of directories which GDB will search for appropriate
2761 set schedule-multiple (on|off)
2762 show schedule-multiple
2763 Allow GDB to resume all threads of all processes or only threads of
2764 the current process.
2768 Use more aggressive caching for accesses to the stack. This improves
2769 performance of remote debugging (particularly backtraces) without
2770 affecting correctness.
2772 set interactive-mode (on|off|auto)
2773 show interactive-mode
2774 Control whether GDB runs in interactive mode (on) or not (off).
2775 When in interactive mode, GDB waits for the user to answer all
2776 queries. Otherwise, GDB does not wait and assumes the default
2777 answer. When set to auto (the default), GDB determines which
2778 mode to use based on the stdin settings.
2783 For program forks, this is replaced by the new more generic `info
2784 inferiors' command. To list checkpoints, you can still use the
2785 `info checkpoints' command, which was an alias for the `info forks'
2789 Replaced by the new `inferior' command. To switch between
2790 checkpoints, you can still use the `restart' command, which was an
2791 alias for the `fork' command.
2794 This is removed, since some targets don't have a notion of
2795 processes. To switch between processes, you can still use the
2796 `inferior' command using GDB's own inferior number.
2799 For program forks, this is replaced by the new more generic `kill
2800 inferior' command. To delete a checkpoint, you can still use the
2801 `delete checkpoint' command, which was an alias for the `delete
2805 For program forks, this is replaced by the new more generic `detach
2806 inferior' command. To detach a checkpoint, you can still use the
2807 `detach checkpoint' command, which was an alias for the `detach
2810 * New native configurations
2812 x86/x86_64 Darwin i[34567]86-*-darwin*
2814 x86_64 MinGW x86_64-*-mingw*
2818 Lattice Mico32 lm32-*
2819 x86 DICOS i[34567]86-*-dicos*
2820 x86_64 DICOS x86_64-*-dicos*
2823 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2824 (mingw32ce) debugging.
2830 These commands were actually not implemented on any target.
2832 *** Changes in GDB 6.8
2834 * New native configurations
2836 NetBSD/hppa hppa*-*netbsd*
2837 Xtensa GNU/Linux xtensa*-*-linux*
2841 NetBSD/hppa hppa*-*-netbsd*
2842 Xtensa GNU/Lunux xtensa*-*-linux*
2844 * Change in command line behavior -- corefiles vs. process ids.
2846 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2847 attaching to process NUMBER fails, GDB no longer attempts to open a
2848 core file named NUMBER. Attaching to a program using the -c option
2849 is no longer supported. Instead, use the '-p' or '--pid' options.
2851 * GDB can now be built as a native debugger for debugging Windows x86
2852 (mingw32) Portable Executable (PE) programs.
2854 * Pending breakpoints no longer change their number when their address
2857 * GDB now supports breakpoints with multiple locations,
2858 including breakpoints on C++ constructors, inside C++ templates,
2859 and in inlined functions.
2861 * GDB's ability to debug optimized code has been improved. GDB more
2862 accurately identifies function bodies and lexical blocks that occupy
2863 more than one contiguous range of addresses.
2865 * Target descriptions can now describe registers for PowerPC.
2867 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2868 registers on PowerPC targets.
2870 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2871 targets even when the libthread_db library is not available.
2873 * The GDB remote stub, gdbserver, now supports the new file transfer
2874 commands (remote put, remote get, and remote delete).
2876 * The GDB remote stub, gdbserver, now supports run and attach in
2877 extended-remote mode.
2879 * hppa*64*-*-hpux11* target broken
2880 The debugger is unable to start a program and fails with the following
2881 error: "Error trying to get information about dynamic linker".
2882 The gdb-6.7 release is also affected.
2884 * GDB now supports the --enable-targets= configure option to allow
2885 building a single GDB executable that supports multiple remote
2886 target architectures.
2888 * GDB now supports debugging C and C++ programs which use the
2889 Decimal Floating Point extension. In addition, the PowerPC target
2890 now has a set of pseudo-registers to inspect decimal float values
2891 stored in two consecutive float registers.
2893 * The -break-insert MI command can optionally create pending
2896 * Improved support for debugging Ada
2897 Many improvements to the Ada language support have been made. These
2899 - Better support for Ada2005 interface types
2900 - Improved handling of arrays and slices in general
2901 - Better support for Taft-amendment types
2902 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2904 - Improved command completion in Ada
2907 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2912 set print frame-arguments (all|scalars|none)
2913 show print frame-arguments
2914 The value of this variable can be changed to control which argument
2915 values should be printed by the debugger when displaying a frame.
2920 Transfer files to and from a remote target, and delete remote files.
2927 Transfer files to and from a remote target, and delete remote files.
2929 * New remote packets
2936 Open, close, read, write, and delete files on the remote system.
2939 Attach to an existing process on the remote system, in extended-remote
2943 Run a new process on the remote system, in extended-remote mode.
2945 *** Changes in GDB 6.7
2947 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2948 bfd, libiberty and opcodes, as revealed by static analysis donated by
2949 Coverity, Inc. (http://scan.coverity.com).
2951 * When looking up multiply-defined global symbols, GDB will now prefer the
2952 symbol definition in the current shared library if it was built using the
2953 -Bsymbolic linker option.
2955 * When the Text User Interface (TUI) is not configured, GDB will now
2956 recognize the -tui command-line option and print a message that the TUI
2959 * The GDB remote stub, gdbserver, now has lower overhead for high
2960 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2962 * GDB for MIPS targets now autodetects whether a remote target provides
2963 32-bit or 64-bit register values.
2965 * Support for C++ member pointers has been improved.
2967 * GDB now understands XML target descriptions, which specify the
2968 target's overall architecture. GDB can read a description from
2969 a local file or over the remote serial protocol.
2971 * Vectors of single-byte data use a new integer type which is not
2972 automatically displayed as character or string data.
2974 * The /s format now works with the print command. It displays
2975 arrays of single-byte integers and pointers to single-byte integers
2978 * Target descriptions can now describe target-specific registers,
2979 for architectures which have implemented the support (currently
2980 only ARM, M68K, and MIPS).
2982 * GDB and the GDB remote stub, gdbserver, now support the XScale
2985 * The GDB remote stub, gdbserver, has been updated to support
2986 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2987 has been rewritten to use the standard GDB remote protocol.
2989 * GDB can now step into C++ functions which are called through thunks.
2991 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2993 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2994 layout. It also supports a TextSeg= and DataSeg= response when only
2995 segment base addresses (rather than offsets) are available.
2997 * The /i format now outputs any trailing branch delay slot instructions
2998 immediately following the last instruction within the count specified.
3000 * The GDB remote protocol "T" stop reply packet now supports a
3001 "library" response. Combined with the new "qXfer:libraries:read"
3002 packet, this response allows GDB to debug shared libraries on targets
3003 where the operating system manages the list of loaded libraries (e.g.
3004 Windows and SymbianOS).
3006 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3007 (DLLs) on Windows and Windows CE targets.
3009 * GDB now supports a faster verification that a .debug file matches its binary
3010 according to its build-id signature, if the signature is present.
3016 Enable or disable hardware flow control (RTS/CTS) on the serial port
3017 when debugging using remote targets.
3019 set mem inaccessible-by-default
3020 show mem inaccessible-by-default
3021 If the target supplies a memory map, for instance via the remote
3022 protocol's "qXfer:memory-map:read" packet, setting this variable
3023 prevents GDB from accessing memory outside the memory map. This
3024 is useful for targets with memory mapped registers or which react
3025 badly to accesses of unmapped address space.
3027 set breakpoint auto-hw
3028 show breakpoint auto-hw
3029 If the target supplies a memory map, for instance via the remote
3030 protocol's "qXfer:memory-map:read" packet, setting this variable
3031 lets GDB use hardware breakpoints automatically for memory regions
3032 where it can not use software breakpoints. This covers both the
3033 "break" command and internal breakpoints used for other commands
3034 including "next" and "finish".
3037 catch exception unhandled
3038 Stop the program execution when Ada exceptions are raised.
3041 Stop the program execution when an Ada assertion failed.
3045 Set an alternate system root for target files. This is a more
3046 general version of "set solib-absolute-prefix", which is now
3047 an alias to "set sysroot".
3050 Provide extended SPU facility status information. This set of
3051 commands is available only when debugging the Cell/B.E. SPU
3054 * New native configurations
3056 OpenBSD/sh sh*-*openbsd*
3059 unset tdesc filename
3061 Use the specified local file as an XML target description, and do
3062 not query the target for its built-in description.
3066 OpenBSD/sh sh*-*-openbsd*
3067 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3068 Toshiba Media Processor mep-elf
3070 * New remote packets
3073 Ignore the specified signals; pass them directly to the debugged program
3074 without stopping other threads or reporting them to GDB.
3076 qXfer:features:read:
3077 Read an XML target description from the target, which describes its
3082 Read or write contents of an spufs file on the target system. These
3083 packets are available only on the Cell/B.E. SPU architecture.
3085 qXfer:libraries:read:
3086 Report the loaded shared libraries. Combined with new "T" packet
3087 response, this packet allows GDB to debug shared libraries on
3088 targets where the operating system manages the list of loaded
3089 libraries (e.g. Windows and SymbianOS).
3093 Support for these obsolete configurations has been removed.
3101 i[34567]86-*-lynxos*
3102 i[34567]86-*-netware*
3103 i[34567]86-*-sco3.2v5*
3104 i[34567]86-*-sco3.2v4*
3106 i[34567]86-*-sysv4.2*
3109 i[34567]86-*-unixware2*
3110 i[34567]86-*-unixware*
3119 * Other removed features
3126 Various m68k-only ROM monitors.
3133 Various Renesas ROM monitors and debugging interfaces for SH and
3138 Support for a Macraigor serial interface to on-chip debugging.
3139 GDB does not directly support the newer parallel or USB
3144 A debug information format. The predecessor to DWARF 2 and
3145 DWARF 3, which are still supported.
3147 Support for the HP aCC compiler on HP-UX/PA-RISC
3149 SOM-encapsulated symbolic debugging information, automatic
3150 invocation of pxdb, and the aCC custom C++ ABI. This does not
3151 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3152 with aCC can still be debugged on an assembly level.
3154 MIPS ".pdr" sections
3156 A MIPS-specific format used to describe stack frame layout
3157 in debugging information.
3161 GDB could work with an older version of Guile to debug
3162 the interpreter and Scheme programs running in it.
3164 set mips stack-arg-size
3165 set mips saved-gpreg-size
3167 Use "set mips abi" to control parameter passing for MIPS.
3169 *** Changes in GDB 6.6
3174 Cell Broadband Engine SPU spu-elf
3176 * GDB can now be configured as a cross-debugger targeting native Windows
3177 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3178 running on a Windows system over TCP/IP to debug Windows programs.
3180 * The GDB remote stub, gdbserver, has been updated to support Windows and
3181 Cygwin debugging. Both single-threaded and multi-threaded programs are
3184 * The "set trust-readonly-sections" command works again. This command was
3185 broken in GDB 6.3, 6.4, and 6.5.
3187 * The "load" command now supports writing to flash memory, if the remote
3188 stub provides the required support.
3190 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3191 longer requires symbolic debug information (e.g. DWARF-2).
3196 unset substitute-path
3197 show substitute-path
3198 Manage a list of substitution rules that GDB uses to rewrite the name
3199 of the directories where the sources are located. This can be useful
3200 for instance when the sources were moved to a different location
3201 between compilation and debugging.
3205 Print each CLI command as it is executed. Each command is prefixed with
3206 a number of `+' symbols representing the nesting depth.
3207 The source command now has a `-v' option to enable the same feature.
3211 The ARM Demon monitor support (RDP protocol, "target rdp").
3213 Kernel Object Display, an embedded debugging feature which only worked with
3214 an obsolete version of Cisco IOS.
3216 The 'set download-write-size' and 'show download-write-size' commands.
3218 * New remote packets
3221 Tell a stub about GDB client features, and request remote target features.
3222 The first feature implemented is PacketSize, which allows the target to
3223 specify the size of packets it can handle - to minimize the number of
3224 packets required and improve performance when connected to a remote
3228 Fetch an OS auxilliary vector from the remote stub. This packet is a
3229 more efficient replacement for qPart:auxv:read.
3231 qXfer:memory-map:read:
3232 Fetch a memory map from the remote stub, including information about
3233 RAM, ROM, and flash memory devices.
3238 Erase and program a flash memory device.
3240 * Removed remote packets
3243 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3244 used it, and only gdbserver implemented it.
3246 *** Changes in GDB 6.5
3250 Renesas M32C/M16C m32c-elf
3252 Morpho Technologies ms1 ms1-elf
3256 init-if-undefined Initialize a convenience variable, but
3257 only if it doesn't already have a value.
3259 The following commands are presently only implemented for native GNU/Linux:
3261 checkpoint Save a snapshot of the program state.
3263 restart <n> Return the program state to a
3264 previously saved state.
3266 info checkpoints List currently saved checkpoints.
3268 delete-checkpoint <n> Delete a previously saved checkpoint.
3270 set|show detach-on-fork Tell gdb whether to detach from a newly
3271 forked process, or to keep debugging it.
3273 info forks List forks of the user program that
3274 are available to be debugged.
3276 fork <n> Switch to debugging one of several
3277 forks of the user program that are
3278 available to be debugged.
3280 delete-fork <n> Delete a fork from the list of forks
3281 that are available to be debugged (and
3282 kill the forked process).
3284 detach-fork <n> Delete a fork from the list of forks
3285 that are available to be debugged (and
3286 allow the process to continue).
3290 Morpho Technologies ms2 ms1-elf
3292 * Improved Windows host support
3294 GDB now builds as a cross debugger hosted on i686-mingw32, including
3295 native console support, and remote communications using either
3296 network sockets or serial ports.
3298 * Improved Modula-2 language support
3300 GDB can now print most types in the Modula-2 syntax. This includes:
3301 basic types, set types, record types, enumerated types, range types,
3302 pointer types and ARRAY types. Procedure var parameters are correctly
3303 printed and hexadecimal addresses and character constants are also
3304 written in the Modula-2 syntax. Best results can be obtained by using
3305 GNU Modula-2 together with the -gdwarf-2 command line option.
3309 The ARM rdi-share module.
3311 The Netware NLM debug server.
3313 *** Changes in GDB 6.4
3315 * New native configurations
3317 OpenBSD/arm arm*-*-openbsd*
3318 OpenBSD/mips64 mips64-*-openbsd*
3322 Morpho Technologies ms1 ms1-elf
3324 * New command line options
3326 --batch-silent As for --batch, but totally silent.
3327 --return-child-result The debugger will exist with the same value
3328 the child (debugged) program exited with.
3329 --eval-command COMMAND, -ex COMMAND
3330 Execute a single GDB CLI command. This may be
3331 specified multiple times and in conjunction
3332 with the --command (-x) option.
3334 * Deprecated commands removed
3336 The following commands, that were deprecated in 2000, have been
3340 set|show arm disassembly-flavor set|show arm disassembler
3341 othernames set arm disassembler
3342 set|show remotedebug set|show debug remote
3343 set|show archdebug set|show debug arch
3344 set|show eventdebug set|show debug event
3347 * New BSD user-level threads support
3349 It is now possible to debug programs using the user-level threads
3350 library on OpenBSD and FreeBSD. Currently supported (target)
3353 FreeBSD/amd64 x86_64-*-freebsd*
3354 FreeBSD/i386 i386-*-freebsd*
3355 OpenBSD/i386 i386-*-openbsd*
3357 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3358 are not yet supported.
3360 * New support for Matsushita MN10300 w/sim added
3361 (Work in progress). mn10300-elf.
3363 * REMOVED configurations and files
3365 VxWorks and the XDR protocol *-*-vxworks
3366 Motorola MCORE mcore-*-*
3367 National Semiconductor NS32000 ns32k-*-*
3369 * New "set print array-indexes" command
3371 After turning this setting "on", GDB prints the index of each element
3372 when displaying arrays. The default is "off" to preserve the previous
3375 * VAX floating point support
3377 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3379 * User-defined command support
3381 In addition to using $arg0..$arg9 for argument passing, it is now possible
3382 to use $argc to determine now many arguments have been passed. See the
3383 section on user-defined commands in the user manual for more information.
3385 *** Changes in GDB 6.3:
3387 * New command line option
3389 GDB now accepts -l followed by a number to set the timeout for remote
3392 * GDB works with GCC -feliminate-dwarf2-dups
3394 GDB now supports a more compact representation of DWARF-2 debug
3395 information using DW_FORM_ref_addr references. These are produced
3396 by GCC with the option -feliminate-dwarf2-dups and also by some
3397 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3398 to use -feliminate-dwarf2-dups.
3400 * Internationalization
3402 When supported by the host system, GDB will be built with
3403 internationalization (libintl). The task of marking up the sources is
3404 continued, we're looking forward to our first translation.
3408 Initial support for debugging programs compiled with the GNAT
3409 implementation of the Ada programming language has been integrated
3410 into GDB. In this release, support is limited to expression evaluation.
3412 * New native configurations
3414 GNU/Linux/m32r m32r-*-linux-gnu
3418 GDB's remote protocol now includes support for the 'p' packet. This
3419 packet is used to fetch individual registers from a remote inferior.
3421 * END-OF-LIFE registers[] compatibility module
3423 GDB's internal register infrastructure has been completely rewritten.
3424 The new infrastructure making possible the implementation of key new
3425 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3428 GDB 6.3 will be the last release to include the the registers[]
3429 compatibility module that allowed out-of-date configurations to
3430 continue to work. This change directly impacts the following
3440 powerpc bdm protocol
3442 Unless there is activity to revive these configurations, they will be
3443 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3445 * OBSOLETE configurations and files
3447 Configurations that have been declared obsolete in this release have
3448 been commented out. Unless there is activity to revive these
3449 configurations, the next release of GDB will have their sources
3450 permanently REMOVED.
3459 *** Changes in GDB 6.2.1:
3461 * MIPS `break main; run' gave an heuristic-fence-post warning
3463 When attempting to run even a simple program, a warning about
3464 heuristic-fence-post being hit would be reported. This problem has
3467 * MIPS IRIX 'long double' crashed GDB
3469 When examining a long double variable, GDB would get a segmentation
3470 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3471 IRIX long double values).
3475 A bug in the VAX stack code was causing problems with the "next"
3476 command. This problem has been fixed.
3478 *** Changes in GDB 6.2:
3480 * Fix for ``many threads''
3482 On GNU/Linux systems that use the NPTL threads library, a program
3483 rapidly creating and deleting threads would confuse GDB leading to the
3486 ptrace: No such process.
3487 thread_db_get_info: cannot get thread info: generic error
3489 This problem has been fixed.
3491 * "-async" and "-noasync" options removed.
3493 Support for the broken "-noasync" option has been removed (it caused
3496 * New ``start'' command.
3498 This command runs the program until the begining of the main procedure.
3500 * New BSD Kernel Data Access Library (libkvm) interface
3502 Using ``target kvm'' it is now possible to debug kernel core dumps and
3503 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3504 platforms. Currently supported (native-only) configurations are:
3506 FreeBSD/amd64 x86_64-*-freebsd*
3507 FreeBSD/i386 i?86-*-freebsd*
3508 NetBSD/i386 i?86-*-netbsd*
3509 NetBSD/m68k m68*-*-netbsd*
3510 NetBSD/sparc sparc-*-netbsd*
3511 OpenBSD/amd64 x86_64-*-openbsd*
3512 OpenBSD/i386 i?86-*-openbsd*
3513 OpenBSD/m68k m68*-openbsd*
3514 OpenBSD/sparc sparc-*-openbsd*
3516 * Signal trampoline code overhauled
3518 Many generic problems with GDB's signal handling code have been fixed.
3519 These include: backtraces through non-contiguous stacks; recognition
3520 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3521 call; backtrace through a signal trampoline; step into and out of
3522 signal handlers; and single-stepping in the signal trampoline.
3524 Please note that kernel bugs are a limiting factor here. These
3525 features have been shown to work on an s390 GNU/Linux system that
3526 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3528 * Cygwin support for DWARF 2 added.
3530 * New native configurations
3532 GNU/Linux/hppa hppa*-*-linux*
3533 OpenBSD/hppa hppa*-*-openbsd*
3534 OpenBSD/m68k m68*-*-openbsd*
3535 OpenBSD/m88k m88*-*-openbsd*
3536 OpenBSD/powerpc powerpc-*-openbsd*
3537 NetBSD/vax vax-*-netbsd*
3538 OpenBSD/vax vax-*-openbsd*
3540 * END-OF-LIFE frame compatibility module
3542 GDB's internal frame infrastructure has been completely rewritten.
3543 The new infrastructure making it possible to support key new features
3544 including DWARF 2 Call Frame Information. To aid in the task of
3545 migrating old configurations to this new infrastructure, a
3546 compatibility module, that allowed old configurations to continue to
3547 work, was also included.
3549 GDB 6.2 will be the last release to include this frame compatibility
3550 module. This change directly impacts the following configurations:
3560 Unless there is activity to revive these configurations, they will be
3561 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3563 * REMOVED configurations and files
3565 Sun 3, running SunOS 3 m68*-*-sunos3*
3566 Sun 3, running SunOS 4 m68*-*-sunos4*
3567 Sun 2, running SunOS 3 m68000-*-sunos3*
3568 Sun 2, running SunOS 4 m68000-*-sunos4*
3569 Motorola 680x0 running LynxOS m68*-*-lynxos*
3570 AT&T 3b1/Unix pc m68*-att-*
3571 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3572 decstation mips-dec-* mips-little-*
3573 riscos mips-*-riscos* mips-*-sysv*
3574 sonymips mips-sony-*
3575 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3577 *** Changes in GDB 6.1.1:
3579 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3581 The TUI (Text-mode User Interface) is now built as part of a default
3582 GDB configuration. It is enabled by either selecting the TUI with the
3583 command line option "-i=tui" or by running the separate "gdbtui"
3584 program. For more information on the TUI, see the manual "Debugging
3587 * Pending breakpoint support (also included in GDB 6.1)
3589 Support has been added to allow you to specify breakpoints in shared
3590 libraries that have not yet been loaded. If a breakpoint location
3591 cannot be found, and the "breakpoint pending" option is set to auto,
3592 GDB queries you if you wish to make the breakpoint pending on a future
3593 shared-library load. If and when GDB resolves the breakpoint symbol,
3594 the pending breakpoint is removed as one or more regular breakpoints
3597 Pending breakpoints are very useful for GCJ Java debugging.
3599 * Fixed ISO-C build problems
3601 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3602 non ISO-C code that stopped them being built using a more strict ISO-C
3603 compiler (e.g., IBM's C compiler).
3605 * Fixed build problem on IRIX 5
3607 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3608 wasn't able to compile compile on an IRIX 5 system.
3610 * Added execute permission to gdb/gdbserver/configure
3612 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3613 permission. This bug would cause configure to fail on a number of
3614 systems (Solaris, IRIX). Ref: server/519.
3616 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3618 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3619 has been updated to use constant array sizes.
3621 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3623 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3624 its generated DWARF Call Frame Info. This encoding was causing GDB to
3625 panic, that panic has been fixed. Ref: gdb/1628.
3627 * Fixed a problem when examining parameters in shared library code.
3629 When examining parameters in optimized shared library code generated
3630 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3631 not available''. GDB now correctly displays the variable's value.
3633 *** Changes in GDB 6.1:
3635 * Removed --with-mmalloc
3637 Support for the mmalloc memory manager has been removed, as it
3638 conflicted with the internal gdb byte cache.
3640 * Changes in AMD64 configurations
3642 The AMD64 target now includes the %cs and %ss registers. As a result
3643 the AMD64 remote protocol has changed; this affects the floating-point
3644 and SSE registers. If you rely on those registers for your debugging,
3645 you should upgrade gdbserver on the remote side.
3647 * Revised SPARC target
3649 The SPARC target has been completely revised, incorporating the
3650 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3651 support for LynxOS and SunOS 4 has been dropped. Calling functions
3652 from within GDB on operating systems with a non-executable stack
3653 (Solaris, OpenBSD) now works.
3657 GDB has a new C++ demangler which does a better job on the mangled
3658 names generated by current versions of g++. It also runs faster, so
3659 with this and other changes gdb should now start faster on large C++
3662 * DWARF 2 Location Expressions
3664 GDB support for location expressions has been extended to support function
3665 arguments and frame bases. Older versions of GDB could crash when they
3668 * C++ nested types and namespaces
3670 GDB's support for nested types and namespaces in C++ has been
3671 improved, especially if you use the DWARF 2 debugging format. (This
3672 is the default for recent versions of GCC on most platforms.)
3673 Specifically, if you have a class "Inner" defined within a class or
3674 namespace "Outer", then GDB realizes that the class's name is
3675 "Outer::Inner", not simply "Inner". This should greatly reduce the
3676 frequency of complaints about not finding RTTI symbols. In addition,
3677 if you are stopped at inside of a function defined within a namespace,
3678 GDB modifies its name lookup accordingly.
3680 * New native configurations
3682 NetBSD/amd64 x86_64-*-netbsd*
3683 OpenBSD/amd64 x86_64-*-openbsd*
3684 OpenBSD/alpha alpha*-*-openbsd*
3685 OpenBSD/sparc sparc-*-openbsd*
3686 OpenBSD/sparc64 sparc64-*-openbsd*
3688 * New debugging protocols
3690 M32R with SDI protocol m32r-*-elf*
3692 * "set prompt-escape-char" command deleted.
3694 The command "set prompt-escape-char" has been deleted. This command,
3695 and its very obscure effet on GDB's prompt, was never documented,
3696 tested, nor mentioned in the NEWS file.
3698 * OBSOLETE configurations and files
3700 Configurations that have been declared obsolete in this release have
3701 been commented out. Unless there is activity to revive these
3702 configurations, the next release of GDB will have their sources
3703 permanently REMOVED.
3705 Sun 3, running SunOS 3 m68*-*-sunos3*
3706 Sun 3, running SunOS 4 m68*-*-sunos4*
3707 Sun 2, running SunOS 3 m68000-*-sunos3*
3708 Sun 2, running SunOS 4 m68000-*-sunos4*
3709 Motorola 680x0 running LynxOS m68*-*-lynxos*
3710 AT&T 3b1/Unix pc m68*-att-*
3711 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3712 decstation mips-dec-* mips-little-*
3713 riscos mips-*-riscos* mips-*-sysv*
3714 sonymips mips-sony-*
3715 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3717 * REMOVED configurations and files
3719 SGI Irix-4.x mips-sgi-irix4 or iris4
3720 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3721 Z8000 simulator z8k-zilog-none or z8ksim
3722 Matsushita MN10200 w/simulator mn10200-*-*
3723 H8/500 simulator h8500-hitachi-hms or h8500hms
3724 HP/PA running BSD hppa*-*-bsd*
3725 HP/PA running OSF/1 hppa*-*-osf*
3726 HP/PA Pro target hppa*-*-pro*
3727 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3728 386BSD i[3456]86-*-bsd*
3729 Sequent family i[3456]86-sequent-sysv4*
3730 i[3456]86-sequent-sysv*
3731 i[3456]86-sequent-bsd*
3732 SPARC running LynxOS sparc-*-lynxos*
3733 SPARC running SunOS 4 sparc-*-sunos4*
3734 Tsqware Sparclet sparclet-*-*
3735 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3737 *** Changes in GDB 6.0:
3741 Support for debugging the Objective-C programming language has been
3742 integrated into GDB.
3744 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3746 DWARF 2's Call Frame Information makes available compiler generated
3747 information that more exactly describes the program's run-time stack.
3748 By using this information, GDB is able to provide more robust stack
3751 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3752 have been updated to use a new backtrace mechanism which includes
3753 DWARF 2 CFI support.
3757 GDB's remote protocol has been extended to include support for hosted
3758 file I/O (where the remote target uses GDB's file system). See GDB's
3759 remote protocol documentation for details.
3761 * All targets using the new architecture framework.
3763 All of GDB's targets have been updated to use the new internal
3764 architecture framework. The way is now open for future GDB releases
3765 to include cross-architecture native debugging support (i386 on amd64,
3768 * GNU/Linux's Thread Local Storage (TLS)
3770 GDB now includes support for for the GNU/Linux implementation of
3771 per-thread variables.
3773 * GNU/Linux's Native POSIX Thread Library (NPTL)
3775 GDB's thread code has been updated to work with either the new
3776 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3778 * Separate debug info.
3780 GDB, in conjunction with BINUTILS, now supports a mechanism for
3781 automatically loading debug information from a separate file. Instead
3782 of shipping full debug and non-debug versions of system libraries,
3783 system integrators can now instead ship just the stripped libraries
3784 and optional debug files.
3786 * DWARF 2 Location Expressions
3788 DWARF 2 Location Expressions allow the compiler to more completely
3789 describe the location of variables (even in optimized code) to the
3792 GDB now includes preliminary support for location expressions (support
3793 for DW_OP_piece is still missing).
3797 A number of long standing bugs that caused GDB to die while starting a
3798 Java application have been fixed. GDB's Java support is now
3799 considered "useable".
3801 * GNU/Linux support for fork, vfork, and exec.
3803 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3804 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3807 * GDB supports logging output to a file
3809 There are two new commands, "set logging" and "show logging", which can be
3810 used to capture GDB's output to a file.
3812 * The meaning of "detach" has changed for gdbserver
3814 The "detach" command will now resume the application, as documented. To
3815 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3818 * d10v, m68hc11 `regs' command deprecated
3820 The `info registers' command has been updated so that it displays the
3821 registers using a format identical to the old `regs' command.
3825 A new command, "maint set profile on/off", has been added. This command can
3826 be used to enable or disable profiling while running GDB, to profile a
3827 session or a set of commands. In addition there is a new configure switch,
3828 "--enable-profiling", which will cause GDB to be compiled with profiling
3829 data, for more informative profiling results.
3831 * Default MI syntax changed to "mi2".
3833 The default MI (machine interface) syntax, enabled by the command line
3834 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3835 "mi1", can be enabled by specifying the option "-i=mi1".
3837 Support for the original "mi0" syntax (included in GDB 5.0) has been
3840 Fix for gdb/192: removed extraneous space when displaying frame level.
3841 Fix for gdb/672: update changelist is now output in mi list format.
3842 Fix for gdb/702: a -var-assign that updates the value now shows up
3843 in a subsequent -var-update.
3845 * New native configurations.
3847 FreeBSD/amd64 x86_64-*-freebsd*
3849 * Multi-arched targets.
3851 HP/PA HPUX11 hppa*-*-hpux*
3852 Renesas M32R/D w/simulator m32r-*-elf*
3854 * OBSOLETE configurations and files
3856 Configurations that have been declared obsolete in this release have
3857 been commented out. Unless there is activity to revive these
3858 configurations, the next release of GDB will have their sources
3859 permanently REMOVED.
3861 Z8000 simulator z8k-zilog-none or z8ksim
3862 Matsushita MN10200 w/simulator mn10200-*-*
3863 H8/500 simulator h8500-hitachi-hms or h8500hms
3864 HP/PA running BSD hppa*-*-bsd*
3865 HP/PA running OSF/1 hppa*-*-osf*
3866 HP/PA Pro target hppa*-*-pro*
3867 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3868 Sequent family i[3456]86-sequent-sysv4*
3869 i[3456]86-sequent-sysv*
3870 i[3456]86-sequent-bsd*
3871 Tsqware Sparclet sparclet-*-*
3872 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3874 * REMOVED configurations and files
3877 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3878 IBM AIX PS/2 i[3456]86-*-aix
3879 i386 running Mach 3.0 i[3456]86-*-mach3*
3880 i386 running Mach i[3456]86-*-mach*
3881 i386 running OSF/1 i[3456]86-*osf1mk*
3882 HP/Apollo 68k Family m68*-apollo*-sysv*,
3884 m68*-hp-bsd*, m68*-hp-hpux*
3885 Argonaut Risc Chip (ARC) arc-*-*
3886 Mitsubishi D30V d30v-*-*
3887 Fujitsu FR30 fr30-*-elf*
3888 OS/9000 i[34]86-*-os9k
3889 I960 with MON960 i960-*-coff
3891 * MIPS $fp behavior changed
3893 The convenience variable $fp, for the MIPS, now consistently returns
3894 the address of the current frame's base. Previously, depending on the
3895 context, $fp could refer to either $sp or the current frame's base
3896 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3897 The GNU Source-Level Debugger''.
3899 *** Changes in GDB 5.3:
3901 * GNU/Linux shared library multi-threaded performance improved.
3903 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3904 `/proc', in preference to `ptrace' for memory reads. This may result
3905 in an improvement in the start-up time of multi-threaded, shared
3906 library applications when run under GDB. One GDB user writes: ``loads
3907 shared libs like mad''.
3909 * ``gdbserver'' now supports multi-threaded applications on some targets
3911 Support for debugging multi-threaded applications which use
3912 the GNU/Linux LinuxThreads package has been added for
3913 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3914 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3916 * GDB now supports C/C++ preprocessor macros.
3918 GDB now expands preprocessor macro invocations in C/C++ expressions,
3919 and provides various commands for showing macro definitions and how
3922 The new command `macro expand EXPRESSION' expands any macro
3923 invocations in expression, and shows the result.
3925 The new command `show macro MACRO-NAME' shows the definition of the
3926 macro named MACRO-NAME, and where it was defined.
3928 Most compilers don't include information about macros in the debugging
3929 information by default. In GCC 3.1, for example, you need to compile
3930 your program with the options `-gdwarf-2 -g3'. If the macro
3931 information is present in the executable, GDB will read it.
3933 * Multi-arched targets.
3935 DEC Alpha (partial) alpha*-*-*
3936 DEC VAX (partial) vax-*-*
3938 National Semiconductor NS32000 (partial) ns32k-*-*
3939 Motorola 68000 (partial) m68k-*-*
3940 Motorola MCORE mcore-*-*
3944 Fujitsu FRV architecture added by Red Hat frv*-*-*
3947 * New native configurations
3949 Alpha NetBSD alpha*-*-netbsd*
3950 SH NetBSD sh*-*-netbsdelf*
3951 MIPS NetBSD mips*-*-netbsd*
3952 UltraSPARC NetBSD sparc64-*-netbsd*
3954 * OBSOLETE configurations and files
3956 Configurations that have been declared obsolete in this release have
3957 been commented out. Unless there is activity to revive these
3958 configurations, the next release of GDB will have their sources
3959 permanently REMOVED.
3961 Mitsubishi D30V d30v-*-*
3962 OS/9000 i[34]86-*-os9k
3963 IBM AIX PS/2 i[3456]86-*-aix
3964 Fujitsu FR30 fr30-*-elf*
3965 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3966 Argonaut Risc Chip (ARC) arc-*-*
3967 i386 running Mach 3.0 i[3456]86-*-mach3*
3968 i386 running Mach i[3456]86-*-mach*
3969 i386 running OSF/1 i[3456]86-*osf1mk*
3970 HP/Apollo 68k Family m68*-apollo*-sysv*,
3972 m68*-hp-bsd*, m68*-hp-hpux*
3973 I960 with MON960 i960-*-coff
3975 * OBSOLETE languages
3977 CHILL, a Pascal like language used by telecommunications companies.
3979 * REMOVED configurations and files
3981 AMD 29k family via UDI a29k-amd-udi, udi29k
3982 A29K VxWorks a29k-*-vxworks
3983 AMD 29000 embedded, using EBMON a29k-none-none
3984 AMD 29000 embedded with COFF a29k-none-coff
3985 AMD 29000 embedded with a.out a29k-none-aout
3987 testsuite/gdb.hp/gdb.threads-hp/ directory
3989 * New command "set max-user-call-depth <nnn>"
3991 This command allows the user to limit the call depth of user-defined
3992 commands. The default is 1024.
3994 * Changes in FreeBSD/i386 native debugging.
3996 Support for the "generate-core-file" has been added.
3998 * New commands "dump", "append", and "restore".
4000 These commands allow data to be copied from target memory
4001 to a bfd-format or binary file (dump and append), and back
4002 from a file into memory (restore).
4004 * Improved "next/step" support on multi-processor Alpha Tru64.
4006 The previous single-step mechanism could cause unpredictable problems,
4007 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4008 of a software single-step mechanism prevents this.
4010 *** Changes in GDB 5.2.1:
4018 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4019 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4020 Fix, by Joel Brobecker imported from mainline.
4022 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4023 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4024 Fix, by Fred Fish, imported from mainline.
4026 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4027 Surprisingly enough, it works now.
4028 By Michal Ludvig, imported from mainline.
4030 i386 hardware watchpoint support:
4031 avoid misses on second run for some targets.
4032 By Pierre Muller, imported from mainline.
4034 *** Changes in GDB 5.2:
4036 * New command "set trust-readonly-sections on[off]".
4038 This command is a hint that tells gdb that read-only sections
4039 really are read-only (ie. that their contents will not change).
4040 In this mode, gdb will go to the object file rather than the
4041 target to read memory from read-only sections (such as ".text").
4042 This can be a significant performance improvement on some
4043 (notably embedded) targets.
4045 * New command "generate-core-file" (or "gcore").
4047 This new gdb command allows the user to drop a core file of the child
4048 process state at any time. So far it's been implemented only for
4049 GNU/Linux and Solaris, but should be relatively easily ported to other
4050 hosts. Argument is core file name (defaults to core.<pid>).
4052 * New command line option
4054 GDB now accepts --pid or -p followed by a process id.
4056 * Change in command line behavior -- corefiles vs. process ids.
4058 There is a subtle behavior in the way in which GDB handles
4059 command line arguments. The first non-flag argument is always
4060 a program to debug, but the second non-flag argument may either
4061 be a corefile or a process id. Previously, GDB would attempt to
4062 open the second argument as a corefile, and if that failed, would
4063 issue a superfluous error message and then attempt to attach it as
4064 a process. Now, if the second argument begins with a non-digit,
4065 it will be treated as a corefile. If it begins with a digit,
4066 GDB will attempt to attach it as a process, and if no such process
4067 is found, will then attempt to open it as a corefile.
4069 * Changes in ARM configurations.
4071 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4072 configuration is fully multi-arch.
4074 * New native configurations
4076 ARM NetBSD arm*-*-netbsd*
4077 x86 OpenBSD i[3456]86-*-openbsd*
4078 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4079 Sparc64 running FreeBSD sparc64-*-freebsd*
4083 Sanyo XStormy16 xstormy16-elf
4085 * OBSOLETE configurations and files
4087 Configurations that have been declared obsolete in this release have
4088 been commented out. Unless there is activity to revive these
4089 configurations, the next release of GDB will have their sources
4090 permanently REMOVED.
4092 AMD 29k family via UDI a29k-amd-udi, udi29k
4093 A29K VxWorks a29k-*-vxworks
4094 AMD 29000 embedded, using EBMON a29k-none-none
4095 AMD 29000 embedded with COFF a29k-none-coff
4096 AMD 29000 embedded with a.out a29k-none-aout
4098 testsuite/gdb.hp/gdb.threads-hp/ directory
4100 * REMOVED configurations and files
4102 TI TMS320C80 tic80-*-*
4104 PowerPC Solaris powerpcle-*-solaris*
4105 PowerPC Windows NT powerpcle-*-cygwin32
4106 PowerPC Netware powerpc-*-netware*
4107 Harris/CXUX m88k m88*-harris-cxux*
4108 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4109 ns32k-utek-sysv* ns32k-utek-*
4110 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4111 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4112 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4113 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4114 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4116 * Changes to command line processing
4118 The new `--args' feature can be used to specify command-line arguments
4119 for the inferior from gdb's command line.
4121 * Changes to key bindings
4123 There is a new `operate-and-get-next' function bound to `C-o'.
4125 *** Changes in GDB 5.1.1
4127 Fix compile problem on DJGPP.
4129 Fix a problem with floating-point registers on the i386 being
4132 Fix to stop GDB crashing on .debug_str debug info.
4134 Numerous documentation fixes.
4136 Numerous testsuite fixes.
4138 *** Changes in GDB 5.1:
4140 * New native configurations
4142 Alpha FreeBSD alpha*-*-freebsd*
4143 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4144 MIPS GNU/Linux mips*-*-linux*
4145 MIPS SGI Irix 6.x mips*-sgi-irix6*
4146 ia64 AIX ia64-*-aix*
4147 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4151 Motorola 68HC11 and 68HC12 m68hc11-elf
4153 UltraSparc running GNU/Linux sparc64-*-linux*
4155 * OBSOLETE configurations and files
4157 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4158 Harris/CXUX m88k m88*-harris-cxux*
4159 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4160 ns32k-utek-sysv* ns32k-utek-*
4161 TI TMS320C80 tic80-*-*
4163 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4164 PowerPC Solaris powerpcle-*-solaris*
4165 PowerPC Windows NT powerpcle-*-cygwin32
4166 PowerPC Netware powerpc-*-netware*
4167 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4168 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4169 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4170 Apple Macintosh (MPW) host N/A
4172 stuff.c (Program to stuff files into a specially prepared space in kdb)
4173 kdb-start.c (Main loop for the standalone kernel debugger)
4175 Configurations that have been declared obsolete in this release have
4176 been commented out. Unless there is activity to revive these
4177 configurations, the next release of GDB will have their sources
4178 permanently REMOVED.
4180 * REMOVED configurations and files
4182 Altos 3068 m68*-altos-*
4183 Convex c1-*-*, c2-*-*
4185 ARM RISCix arm-*-* (as host)
4189 * GDB has been converted to ISO C.
4191 GDB's source code has been converted to ISO C. In particular, the
4192 sources are fully protoized, and rely on standard headers being
4197 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4199 * The MI enabled by default.
4201 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4202 revised and enabled by default. Packages which use GDB as a debugging
4203 engine behind a UI or another front end are encouraged to switch to
4204 using the GDB/MI interface, instead of the old annotations interface
4205 which is now deprecated.
4207 * Support for debugging Pascal programs.
4209 GDB now includes support for debugging Pascal programs. The following
4210 main features are supported:
4212 - Pascal-specific data types such as sets;
4214 - automatic recognition of Pascal sources based on file-name
4217 - Pascal-style display of data types, variables, and functions;
4219 - a Pascal expression parser.
4221 However, some important features are not yet supported.
4223 - Pascal string operations are not supported at all;
4225 - there are some problems with boolean types;
4227 - Pascal type hexadecimal constants are not supported
4228 because they conflict with the internal variables format;
4230 - support for Pascal objects and classes is not full yet;
4232 - unlike Pascal, GDB is case-sensitive for symbol names.
4234 * Changes in completion.
4236 Commands such as `shell', `run' and `set args', which pass arguments
4237 to inferior programs, now complete on file names, similar to what
4238 users expect at the shell prompt.
4240 Commands which accept locations, such as `disassemble', `print',
4241 `breakpoint', `until', etc. now complete on filenames as well as
4242 program symbols. Thus, if you type "break foob TAB", and the source
4243 files linked into the programs include `foobar.c', that file name will
4244 be one of the candidates for completion. However, file names are not
4245 considered for completion after you typed a colon that delimits a file
4246 name from a name of a function in that file, as in "break foo.c:bar".
4248 `set demangle-style' completes on available demangling styles.
4250 * New platform-independent commands:
4252 It is now possible to define a post-hook for a command as well as a
4253 hook that runs before the command. For more details, see the
4254 documentation of `hookpost' in the GDB manual.
4256 * Changes in GNU/Linux native debugging.
4258 Support for debugging multi-threaded programs has been completely
4259 revised for all platforms except m68k and sparc. You can now debug as
4260 many threads as your system allows you to have.
4262 Attach/detach is supported for multi-threaded programs.
4264 Support for SSE registers was added for x86. This doesn't work for
4265 multi-threaded programs though.
4267 * Changes in MIPS configurations.
4269 Multi-arch support is enabled for all MIPS configurations.
4271 GDB can now be built as native debugger on SGI Irix 6.x systems for
4272 debugging n32 executables. (Debugging 64-bit executables is not yet
4275 * Unified support for hardware watchpoints in all x86 configurations.
4277 Most (if not all) native x86 configurations support hardware-assisted
4278 breakpoints and watchpoints in a unified manner. This support
4279 implements debug register sharing between watchpoints, which allows to
4280 put a virtually infinite number of watchpoints on the same address,
4281 and also supports watching regions up to 16 bytes with several debug
4284 The new maintenance command `maintenance show-debug-regs' toggles
4285 debugging print-outs in functions that insert, remove, and test
4286 watchpoints and hardware breakpoints.
4288 * Changes in the DJGPP native configuration.
4290 New command ``info dos sysinfo'' displays assorted information about
4291 the CPU, OS, memory, and DPMI server.
4293 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4294 display information about segment descriptors stored in GDT, LDT, and
4297 New commands ``info dos pde'' and ``info dos pte'' display entries
4298 from Page Directory and Page Tables (for now works with CWSDPMI only).
4299 New command ``info dos address-pte'' displays the Page Table entry for
4300 a given linear address.
4302 GDB can now pass command lines longer than 126 characters to the
4303 program being debugged (requires an update to the libdbg.a library
4304 which is part of the DJGPP development kit).
4306 DWARF2 debug info is now supported.
4308 It is now possible to `step' and `next' through calls to `longjmp'.
4310 * Changes in documentation.
4312 All GDB documentation was converted to GFDL, the GNU Free
4313 Documentation License.
4315 Tracepoints-related commands are now fully documented in the GDB
4318 TUI, the Text-mode User Interface, is now documented in the manual.
4320 Tracepoints-related commands are now fully documented in the GDB
4323 The "GDB Internals" manual now has an index. It also includes
4324 documentation of `ui_out' functions, GDB coding standards, x86
4325 hardware watchpoints, and memory region attributes.
4327 * GDB's version number moved to ``version.in''
4329 The Makefile variable VERSION has been replaced by the file
4330 ``version.in''. People creating GDB distributions should update the
4331 contents of this file.
4335 GUD support is now a standard part of the EMACS distribution.
4337 *** Changes in GDB 5.0:
4339 * Improved support for debugging FP programs on x86 targets
4341 Unified and much-improved support for debugging floating-point
4342 programs on all x86 targets. In particular, ``info float'' now
4343 displays the FP registers in the same format on all x86 targets, with
4344 greater level of detail.
4346 * Improvements and bugfixes in hardware-assisted watchpoints
4348 It is now possible to watch array elements, struct members, and
4349 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4350 on x86 targets no longer erroneously trigger when the address is
4353 * Improvements in the native DJGPP version of GDB
4355 The distribution now includes all the scripts and auxiliary files
4356 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4357 machines ``out of the box''.
4359 The DJGPP version can now debug programs that use signals. It is
4360 possible to catch signals that happened in the debuggee, deliver
4361 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4362 would kill the program being debugged.) Programs that hook hardware
4363 interrupts (keyboard, timer, etc.) can also be debugged.
4365 It is now possible to debug DJGPP programs that redirect their
4366 standard handles or switch them to raw (as opposed to cooked) mode, or
4367 even close them. The command ``run < foo > bar'' works as expected,
4368 and ``info terminal'' reports useful information about the debuggee's
4369 terminal, including raw/cooked mode, redirection, etc.
4371 The DJGPP version now uses termios functions for console I/O, which
4372 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4375 DOS-style file names with drive letters are now fully supported by
4378 It is now possible to debug DJGPP programs that switch their working
4379 directory. It is also possible to rerun the debuggee any number of
4380 times without restarting GDB; thus, you can use the same setup,
4381 breakpoints, etc. for many debugging sessions.
4383 * New native configurations
4385 ARM GNU/Linux arm*-*-linux*
4386 PowerPC GNU/Linux powerpc-*-linux*
4390 Motorola MCore mcore-*-*
4391 x86 VxWorks i[3456]86-*-vxworks*
4392 PowerPC VxWorks powerpc-*-vxworks*
4393 TI TMS320C80 tic80-*-*
4395 * OBSOLETE configurations
4397 Altos 3068 m68*-altos-*
4398 Convex c1-*-*, c2-*-*
4400 ARM RISCix arm-*-* (as host)
4403 Configurations that have been declared obsolete will be commented out,
4404 but the code will be left in place. If there is no activity to revive
4405 these configurations before the next release of GDB, the sources will
4406 be permanently REMOVED.
4408 * Gould support removed
4410 Support for the Gould PowerNode and NP1 has been removed.
4412 * New features for SVR4
4414 On SVR4 native platforms (such as Solaris), if you attach to a process
4415 without first loading a symbol file, GDB will now attempt to locate and
4416 load symbols from the running process's executable file.
4418 * Many C++ enhancements
4420 C++ support has been greatly improved. Overload resolution now works properly
4421 in almost all cases. RTTI support is on the way.
4423 * Remote targets can connect to a sub-program
4425 A popen(3) style serial-device has been added. This device starts a
4426 sub-process (such as a stand-alone simulator) and then communicates
4427 with that. The sub-program to run is specified using the syntax
4428 ``|<program> <args>'' vis:
4430 (gdb) set remotedebug 1
4431 (gdb) target extended-remote |mn10300-elf-sim program-args
4433 * MIPS 64 remote protocol
4435 A long standing bug in the mips64 remote protocol where by GDB
4436 expected certain 32 bit registers (ex SR) to be transfered as 32
4437 instead of 64 bits has been fixed.
4439 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4440 added to provide backward compatibility with older versions of GDB.
4442 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4444 The command ``set remotebinarydownload'' command has been replaced by
4445 ``set remote X-packet''. Other commands in ``set remote'' family
4446 include ``set remote P-packet''.
4448 * Breakpoint commands accept ranges.
4450 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4451 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4452 ``tracepoint passcount'' also accepts a range of tracepoints.
4454 * ``apropos'' command added.
4456 The ``apropos'' command searches through command names and
4457 documentation strings, printing out matches, making it much easier to
4458 try to find a command that does what you are looking for.
4462 A new machine oriented interface (MI) has been added to GDB. This
4463 interface is designed for debug environments running GDB as a separate
4464 process. This is part of the long term libGDB project. See the
4465 "GDB/MI" chapter of the GDB manual for further information. It can be
4466 enabled by configuring with:
4468 .../configure --enable-gdbmi
4470 *** Changes in GDB-4.18:
4472 * New native configurations
4474 HP-UX 10.20 hppa*-*-hpux10.20
4475 HP-UX 11.x hppa*-*-hpux11.0*
4476 M68K GNU/Linux m68*-*-linux*
4480 Fujitsu FR30 fr30-*-elf*
4481 Intel StrongARM strongarm-*-*
4482 Mitsubishi D30V d30v-*-*
4484 * OBSOLETE configurations
4486 Gould PowerNode, NP1 np1-*-*, pn-*-*
4488 Configurations that have been declared obsolete will be commented out,
4489 but the code will be left in place. If there is no activity to revive
4490 these configurations before the next release of GDB, the sources will
4491 be permanently REMOVED.
4495 As a compatibility experiment, GDB's source files buildsym.h and
4496 buildsym.c have been converted to pure standard C, no longer
4497 containing any K&R compatibility code. We believe that all systems in
4498 use today either come with a standard C compiler, or have a GCC port
4499 available. If this is not true, please report the affected
4500 configuration to bug-gdb@gnu.org immediately. See the README file for
4501 information about getting a standard C compiler if you don't have one
4506 GDB now uses readline 2.2.
4508 * set extension-language
4510 You can now control the mapping between filename extensions and source
4511 languages by using the `set extension-language' command. For instance,
4512 you can ask GDB to treat .c files as C++ by saying
4513 set extension-language .c c++
4514 The command `info extensions' lists all of the recognized extensions
4515 and their associated languages.
4517 * Setting processor type for PowerPC and RS/6000
4519 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4520 you can use the `set processor' command to specify what variant of the
4521 PowerPC family you are debugging. The command
4525 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4526 following PowerPC and RS6000 variants:
4528 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4529 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4531 403GC IBM PowerPC 403GC
4532 505 Motorola PowerPC 505
4533 860 Motorola PowerPC 860 or 850
4534 601 Motorola PowerPC 601
4535 602 Motorola PowerPC 602
4536 603 Motorola/IBM PowerPC 603 or 603e
4537 604 Motorola PowerPC 604 or 604e
4538 750 Motorola/IBM PowerPC 750 or 750
4540 At the moment, this command just tells GDB what to name the
4541 special-purpose processor registers. Since almost all the affected
4542 registers are inaccessible to user-level programs, this command is
4543 only useful for remote debugging in its present form.
4547 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4548 more extensive support for HP-UX. Added features include shared
4549 library support, kernel threads and hardware watchpoints for 11.00,
4550 support for HP's ANSI C and C++ compilers, and a compatibility mode
4551 for xdb and dbx commands.
4555 HP's donation includes the new concept of catchpoints, which is a
4556 generalization of the old catch command. On HP-UX, it is now possible
4557 to catch exec, fork, and vfork, as well as library loading.
4559 This means that the existing catch command has changed; its first
4560 argument now specifies the type of catch to be set up. See the
4561 output of "help catch" for a list of catchpoint types.
4563 * Debugging across forks
4565 On HP-UX, you can choose which process to debug when a fork() happens
4570 HP has donated a curses-based terminal user interface (TUI). To get
4571 it, build with --enable-tui. Although this can be enabled for any
4572 configuration, at present it only works for native HP debugging.
4574 * GDB remote protocol additions
4576 A new protocol packet 'X' that writes binary data is now available.
4577 Default behavior is to try 'X', then drop back to 'M' if the stub
4578 fails to respond. The settable variable `remotebinarydownload'
4579 allows explicit control over the use of 'X'.
4581 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4582 full 64-bit address. The command
4584 set remoteaddresssize 32
4586 can be used to revert to the old behaviour. For existing remote stubs
4587 the change should not be noticed, as the additional address information
4590 In order to assist in debugging stubs, you may use the maintenance
4591 command `packet' to send any text string to the stub. For instance,
4593 maint packet heythere
4595 sends the packet "$heythere#<checksum>". Note that it is very easy to
4596 disrupt a debugging session by sending the wrong packet at the wrong
4599 The compare-sections command allows you to compare section data on the
4600 target to what is in the executable file without uploading or
4601 downloading, by comparing CRC checksums.
4603 * Tracing can collect general expressions
4605 You may now collect general expressions at tracepoints. This requires
4606 further additions to the target-side stub; see tracepoint.c and
4607 doc/agentexpr.texi for further details.
4609 * mask-address variable for Mips
4611 For Mips targets, you may control the zeroing of the upper 32 bits of
4612 a 64-bit address by entering `set mask-address on'. This is mainly
4613 of interest to users of embedded R4xxx and R5xxx processors.
4615 * Higher serial baud rates
4617 GDB's serial code now allows you to specify baud rates 57600, 115200,
4618 230400, and 460800 baud. (Note that your host system may not be able
4619 to achieve all of these rates.)
4623 The i960 configuration now includes an initial implementation of a
4624 builtin simulator, contributed by Jim Wilson.
4627 *** Changes in GDB-4.17:
4629 * New native configurations
4631 Alpha GNU/Linux alpha*-*-linux*
4632 Unixware 2.x i[3456]86-unixware2*
4633 Irix 6.x mips*-sgi-irix6*
4634 PowerPC GNU/Linux powerpc-*-linux*
4635 PowerPC Solaris powerpcle-*-solaris*
4636 Sparc GNU/Linux sparc-*-linux*
4637 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4641 Argonaut Risc Chip (ARC) arc-*-*
4642 Hitachi H8/300S h8300*-*-*
4643 Matsushita MN10200 w/simulator mn10200-*-*
4644 Matsushita MN10300 w/simulator mn10300-*-*
4645 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4646 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4647 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4648 Mitsubishi D10V w/simulator d10v-*-*
4649 Mitsubishi M32R/D w/simulator m32r-*-elf*
4650 Tsqware Sparclet sparclet-*-*
4651 NEC V850 w/simulator v850-*-*
4653 * New debugging protocols
4655 ARM with RDI protocol arm*-*-*
4656 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4657 DDB and LSI variants of PMON protocol mips*-*-*
4658 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4659 PowerPC with SDS protocol powerpc{,le}-*-eabi
4660 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4664 All configurations can now understand and use the DWARF 2 debugging
4665 format. The choice is automatic, if the symbol file contains DWARF 2
4670 GDB now includes basic Java language support. This support is
4671 only useful with Java compilers that produce native machine code.
4673 * solib-absolute-prefix and solib-search-path
4675 For SunOS and SVR4 shared libraries, you may now set the prefix for
4676 loading absolute shared library symbol files, and the search path for
4677 locating non-absolute shared library symbol files.
4679 * Live range splitting
4681 GDB can now effectively debug code for which GCC has performed live
4682 range splitting as part of its optimization. See gdb/doc/LRS for
4683 more details on the expected format of the stabs information.
4687 GDB's support for the GNU Hurd, including thread debugging, has been
4688 updated to work with current versions of the Hurd.
4692 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4693 instruction set. ARM GDB automatically detects when Thumb
4694 instructions are in use, and adjusts disassembly and backtracing
4699 GDB's MIPS target configurations now handle the MIP16 16-bit
4704 GDB now includes support for overlays; if an executable has been
4705 linked such that multiple sections are based at the same address, GDB
4706 will decide which section to use for symbolic info. You can choose to
4707 control the decision manually, using overlay commands, or implement
4708 additional target-side support and use "overlay load-target" to bring
4709 in the overlay mapping. Do "help overlay" for more detail.
4713 The command "info symbol <address>" displays information about
4714 the symbol at the specified address.
4718 The standard remote protocol now includes an extension that allows
4719 asynchronous collection and display of trace data. This requires
4720 extensive support in the target-side debugging stub. Tracing mode
4721 includes a new interaction mode in GDB and new commands: see the
4722 file tracepoint.c for more details.
4726 Configurations for embedded MIPS now include a simulator contributed
4727 by Cygnus Solutions. The simulator supports the instruction sets
4728 of most MIPS variants.
4732 Sparc configurations may now include the ERC32 simulator contributed
4733 by the European Space Agency. The simulator is not built into
4734 Sparc targets by default; configure with --enable-sim to include it.
4738 For target configurations that may include multiple variants of a
4739 basic architecture (such as MIPS and SH), you may now set the
4740 architecture explicitly. "set arch" sets, "info arch" lists
4741 the possible architectures.
4743 *** Changes in GDB-4.16:
4745 * New native configurations
4747 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4748 M68K NetBSD m68k-*-netbsd*
4749 PowerPC AIX 4.x powerpc-*-aix*
4750 PowerPC MacOS powerpc-*-macos*
4751 PowerPC Windows NT powerpcle-*-cygwin32
4752 RS/6000 AIX 4.x rs6000-*-aix4*
4756 ARM with RDP protocol arm-*-*
4757 I960 with MON960 i960-*-coff
4758 MIPS VxWorks mips*-*-vxworks*
4759 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4760 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4762 Matra Sparclet sparclet-*-*
4766 The powerpc-eabi configuration now includes the PSIM simulator,
4767 contributed by Andrew Cagney, with assistance from Mike Meissner.
4768 PSIM is a very elaborate model of the PowerPC, including not only
4769 basic instruction set execution, but also details of execution unit
4770 performance and I/O hardware. See sim/ppc/README for more details.
4774 GDB now works with Solaris 2.5.
4776 * Windows 95/NT native
4778 GDB will now work as a native debugger on Windows 95 and Windows NT.
4779 To build it from source, you must use the "gnu-win32" environment,
4780 which uses a DLL to emulate enough of Unix to run the GNU tools.
4781 Further information, binaries, and sources are available at
4782 ftp.cygnus.com, under pub/gnu-win32.
4784 * dont-repeat command
4786 If a user-defined command includes the command `dont-repeat', then the
4787 command will not be repeated if the user just types return. This is
4788 useful if the command is time-consuming to run, so that accidental
4789 extra keystrokes don't run the same command many times.
4791 * Send break instead of ^C
4793 The standard remote protocol now includes an option to send a break
4794 rather than a ^C to the target in order to interrupt it. By default,
4795 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4797 * Remote protocol timeout
4799 The standard remote protocol includes a new variable `remotetimeout'
4800 that allows you to set the number of seconds before GDB gives up trying
4801 to read from the target. The default value is 2.
4803 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4805 By default GDB will automatically keep track of objects as they are
4806 loaded and unloaded by the dynamic linker. By using the command `set
4807 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4808 when shared library events occur, thus allowing you to set breakpoints
4809 in shared libraries which are explicitly loaded by the inferior.
4811 Note this feature does not work on hpux8. On hpux9 you must link
4812 /usr/lib/end.o into your program. This feature should work
4813 automatically on hpux10.
4815 * Irix 5.x hardware watchpoint support
4817 Irix 5 configurations now support the use of hardware watchpoints.
4819 * Mips protocol "SYN garbage limit"
4821 When debugging a Mips target using the `target mips' protocol, you
4822 may set the number of characters that GDB will ignore by setting
4823 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4824 every character. The default value is 1050.
4826 * Recording and replaying remote debug sessions
4828 If you set `remotelogfile' to the name of a file, gdb will write to it
4829 a recording of a remote debug session. This recording may then be
4830 replayed back to gdb using "gdbreplay". See gdbserver/README for
4831 details. This is useful when you have a problem with GDB while doing
4832 remote debugging; you can make a recording of the session and send it
4833 to someone else, who can then recreate the problem.
4835 * Speedups for remote debugging
4837 GDB includes speedups for downloading and stepping MIPS systems using
4838 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4839 and more efficient S-record downloading.
4841 * Memory use reductions and statistics collection
4843 GDB now uses less memory and reports statistics about memory usage.
4844 Try the `maint print statistics' command, for example.
4846 *** Changes in GDB-4.15:
4848 * Psymtabs for XCOFF
4850 The symbol reader for AIX GDB now uses partial symbol tables. This
4851 can greatly improve startup time, especially for large executables.
4853 * Remote targets use caching
4855 Remote targets now use a data cache to speed up communication with the
4856 remote side. The data cache could lead to incorrect results because
4857 it doesn't know about volatile variables, thus making it impossible to
4858 debug targets which use memory mapped I/O devices. `set remotecache
4859 off' turns the the data cache off.
4861 * Remote targets may have threads
4863 The standard remote protocol now includes support for multiple threads
4864 in the target system, using new protocol commands 'H' and 'T'. See
4865 gdb/remote.c for details.
4869 If GDB is configured with `--enable-netrom', then it will include
4870 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4871 acts as though it is a bank of ROM on the target board, but you can
4872 write into it over the network. GDB's support consists only of
4873 support for fast loading into the emulated ROM; to debug, you must use
4874 another protocol, such as standard remote protocol. The usual
4875 sequence is something like
4877 target nrom <netrom-hostname>
4879 target remote <netrom-hostname>:1235
4883 GDB now includes support for the Apple Macintosh, as a host only. It
4884 may be run as either an MPW tool or as a standalone application, and
4885 it can debug through the serial port. All the usual GDB commands are
4886 available, but to the target command, you must supply "serial" as the
4887 device type instead of "/dev/ttyXX". See mpw-README in the main
4888 directory for more information on how to build. The MPW configuration
4889 scripts */mpw-config.in support only a few targets, and only the
4890 mips-idt-ecoff target has been tested.
4894 GDB configuration now uses autoconf. This is not user-visible,
4895 but does simplify configuration and building.
4899 GDB now supports hpux10.
4901 *** Changes in GDB-4.14:
4903 * New native configurations
4905 x86 FreeBSD i[345]86-*-freebsd
4906 x86 NetBSD i[345]86-*-netbsd
4907 NS32k NetBSD ns32k-*-netbsd
4908 Sparc NetBSD sparc-*-netbsd
4912 A29K VxWorks a29k-*-vxworks
4913 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4914 CPU32 EST-300 emulator m68*-*-est*
4915 PowerPC ELF powerpc-*-elf
4918 * Alpha OSF/1 support for procfs
4920 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4921 possible to attach to running processes. As the mounting of the /proc
4922 filesystem is optional on the Alpha, GDB automatically determines
4923 the availability of /proc during startup. This can lead to problems
4924 if /proc is unmounted after GDB has been started.
4926 * Arguments to user-defined commands
4928 User commands may accept up to 10 arguments separated by whitespace.
4929 Arguments are accessed within the user command via $arg0..$arg9. A
4932 print $arg0 + $arg1 + $arg2
4934 To execute the command use:
4937 Defines the command "adder" which prints the sum of its three arguments.
4938 Note the arguments are text substitutions, so they may reference variables,
4939 use complex expressions, or even perform inferior function calls.
4941 * New `if' and `while' commands
4943 This makes it possible to write more sophisticated user-defined
4944 commands. Both commands take a single argument, which is the
4945 expression to evaluate, and must be followed by the commands to
4946 execute, one per line, if the expression is nonzero, the list being
4947 terminated by the word `end'. The `if' command list may include an
4948 `else' word, which causes the following commands to be executed only
4949 if the expression is zero.
4951 * Fortran source language mode
4953 GDB now includes partial support for Fortran 77. It will recognize
4954 Fortran programs and can evaluate a subset of Fortran expressions, but
4955 variables and functions may not be handled correctly. GDB will work
4956 with G77, but does not yet know much about symbols emitted by other
4959 * Better HPUX support
4961 Most debugging facilities now work on dynamic executables for HPPAs
4962 running hpux9 or later. You can attach to running dynamically linked
4963 processes, but by default the dynamic libraries will be read-only, so
4964 for instance you won't be able to put breakpoints in them. To change
4965 that behavior do the following before running the program:
4971 This will cause the libraries to be mapped private and read-write.
4972 To revert to the normal behavior, do this:
4978 You cannot set breakpoints or examine data in the library until after
4979 the library is loaded if the function/data symbols do not have
4982 GDB can now also read debug symbols produced by the HP C compiler on
4983 HPPAs (sorry, no C++, Fortran or 68k support).
4985 * Target byte order now dynamically selectable
4987 You can choose which byte order to use with a target system, via the
4988 commands "set endian big" and "set endian little", and you can see the
4989 current setting by using "show endian". You can also give the command
4990 "set endian auto", in which case GDB will use the byte order
4991 associated with the executable. Currently, only embedded MIPS
4992 configurations support dynamic selection of target byte order.
4994 * New DOS host serial code
4996 This version uses DPMI interrupts to handle buffered I/O, so you
4997 no longer need to run asynctsr when debugging boards connected to
5000 *** Changes in GDB-4.13:
5002 * New "complete" command
5004 This lists all the possible completions for the rest of the line, if it
5005 were to be given as a command itself. This is intended for use by emacs.
5007 * Trailing space optional in prompt
5009 "set prompt" no longer adds a space for you after the prompt you set. This
5010 allows you to set a prompt which ends in a space or one that does not.
5012 * Breakpoint hit counts
5014 "info break" now displays a count of the number of times the breakpoint
5015 has been hit. This is especially useful in conjunction with "ignore"; you
5016 can ignore a large number of breakpoint hits, look at the breakpoint info
5017 to see how many times the breakpoint was hit, then run again, ignoring one
5018 less than that number, and this will get you quickly to the last hit of
5021 * Ability to stop printing at NULL character
5023 "set print null-stop" will cause GDB to stop printing the characters of
5024 an array when the first NULL is encountered. This is useful when large
5025 arrays actually contain only short strings.
5027 * Shared library breakpoints
5029 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5030 breakpoints in shared libraries before the executable is run.
5032 * Hardware watchpoints
5034 There is a new hardware breakpoint for the watch command for sparclite
5035 targets. See gdb/sparclite/hw_breakpoint.note.
5037 Hardware watchpoints are also now supported under GNU/Linux.
5041 Annotations have been added. These are for use with graphical interfaces,
5042 and are still experimental. Currently only gdba.el uses these.
5044 * Improved Irix 5 support
5046 GDB now works properly with Irix 5.2.
5048 * Improved HPPA support
5050 GDB now works properly with the latest GCC and GAS.
5052 * New native configurations
5054 Sequent PTX4 i[34]86-sequent-ptx4
5055 HPPA running OSF/1 hppa*-*-osf*
5056 Atari TT running SVR4 m68*-*-sysv4*
5057 RS/6000 LynxOS rs6000-*-lynxos*
5061 OS/9000 i[34]86-*-os9k
5062 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5065 * Hitachi SH7000 and E7000-PC ICE support
5067 There is now support for communicating with the Hitachi E7000-PC ICE.
5068 This is available automatically when GDB is configured for the SH.
5072 As usual, a variety of small fixes and improvements, both generic
5073 and configuration-specific. See the ChangeLog for more detail.
5075 *** Changes in GDB-4.12:
5077 * Irix 5 is now supported
5081 GDB-4.12 on the HPPA has a number of changes which make it unable
5082 to debug the output from the currently released versions of GCC and
5083 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5084 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5085 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5088 *** Changes in GDB-4.11:
5090 * User visible changes:
5094 The "set remotedebug" option is now consistent between the mips remote
5095 target, remote targets using the gdb-specific protocol, UDI (AMD's
5096 debug protocol for the 29k) and the 88k bug monitor. It is now an
5097 integer specifying a debug level (normally 0 or 1, but 2 means more
5098 debugging info for the mips target).
5100 * DEC Alpha native support
5102 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5103 debug info, but GDB works fairly well with the DEC compiler and should
5104 work with a future GCC release. See the README file for a few
5105 Alpha-specific notes.
5107 * Preliminary thread implementation
5109 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5111 * LynxOS native and target support for 386
5113 This release has been hosted on LynxOS 2.2, and also can be configured
5114 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5117 * Improvements in C++ mangling/demangling.
5119 This release has much better g++ debugging, specifically in name
5120 mangling/demangling, virtual function calls, print virtual table,
5121 call methods, ...etc.
5123 *** Changes in GDB-4.10:
5125 * User visible changes:
5127 Remote debugging using the GDB-specific (`target remote') protocol now
5128 supports the `load' command. This is only useful if you have some
5129 other way of getting the stub to the target system, and you can put it
5130 somewhere in memory where it won't get clobbered by the download.
5132 Filename completion now works.
5134 When run under emacs mode, the "info line" command now causes the
5135 arrow to point to the line specified. Also, "info line" prints
5136 addresses in symbolic form (as well as hex).
5138 All vxworks based targets now support a user settable option, called
5139 vxworks-timeout. This option represents the number of seconds gdb
5140 should wait for responses to rpc's. You might want to use this if
5141 your vxworks target is, perhaps, a slow software simulator or happens
5142 to be on the far side of a thin network line.
5146 This release contains support for using a DEC alpha as a GDB host for
5147 cross debugging. Native alpha debugging is not supported yet.
5150 *** Changes in GDB-4.9:
5154 This is the first GDB release which is accompanied by a matching testsuite.
5155 The testsuite requires installation of dejagnu, which should be available
5156 via ftp from most sites that carry GNU software.
5160 'Cfront' style demangling has had its name changed to 'ARM' style, to
5161 emphasize that it was written from the specifications in the C++ Annotated
5162 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5163 disclaimers, it still generated too much confusion with users attempting to
5164 use gdb with AT&T cfront.
5168 GDB now uses a standard remote interface to a simulator library.
5169 So far, the library contains simulators for the Zilog Z8001/2, the
5170 Hitachi H8/300, H8/500 and Super-H.
5172 * New targets supported
5174 H8/300 simulator h8300-hitachi-hms or h8300hms
5175 H8/500 simulator h8500-hitachi-hms or h8500hms
5176 SH simulator sh-hitachi-hms or sh
5177 Z8000 simulator z8k-zilog-none or z8ksim
5178 IDT MIPS board over serial line mips-idt-ecoff
5180 Cross-debugging to GO32 targets is supported. It requires a custom
5181 version of the i386-stub.c module which is integrated with the
5182 GO32 memory extender.
5184 * New remote protocols
5186 MIPS remote debugging protocol.
5188 * New source languages supported
5190 This version includes preliminary support for Chill, a Pascal like language
5191 used by telecommunications companies. Chill support is also being integrated
5192 into the GNU compiler, but we don't know when it will be publically available.
5195 *** Changes in GDB-4.8:
5197 * HP Precision Architecture supported
5199 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5200 version of this support was available as a set of patches from the
5201 University of Utah. GDB does not support debugging of programs
5202 compiled with the HP compiler, because HP will not document their file
5203 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5204 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5206 Many problems in the preliminary version have been fixed.
5208 * Faster and better demangling
5210 We have improved template demangling and fixed numerous bugs in the GNU style
5211 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5212 character types (wchar_t) are now supported. Demangling of each symbol is now
5213 only done once, and is cached when the symbol table for a file is read in.
5214 This results in a small increase in memory usage for C programs, a moderate
5215 increase in memory usage for C++ programs, and a fantastic speedup in
5218 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5219 from the specifications in the Annotated Reference Manual, which AT&T's
5220 compiler does not actually implement.
5222 * G++ multiple inheritance compiler problem
5224 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5225 inheritance lattices was reworked to properly discover ambiguities. We
5226 recently found an example which causes this new algorithm to fail in a
5227 very subtle way, producing bad debug information for those classes.
5228 The file 'gcc.patch' (in this directory) can be applied to gcc to
5229 circumvent the problem. A future GCC release will contain a complete
5232 The previous G++ debug info problem (mentioned below for the gdb-4.7
5233 release) is fixed in gcc version 2.3.2.
5235 * Improved configure script
5237 The `configure' script will now attempt to guess your system type if
5238 you don't supply a host system type. The old scheme of supplying a
5239 host system triplet is preferable over using this. All the magic is
5240 done in the new `config.guess' script. Examine it for details.
5242 We have also brought our configure script much more in line with the FSF's
5243 version. It now supports the --with-xxx options. In particular,
5244 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5245 The resulting GDB will not be able to read arbitrary object file formats --
5246 only the format ``expected'' to be used on the configured target system.
5247 We hope to make this the default in a future release.
5249 * Documentation improvements
5251 There's new internal documentation on how to modify GDB, and how to
5252 produce clean changes to the code. We implore people to read it
5253 before submitting changes.
5255 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5256 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5257 `info' files are also provided. To build `info' files from scratch,
5258 you will need the latest `makeinfo' release, which will be available in
5259 a future texinfo-X.Y release.
5261 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5262 We're not sure exactly which versions have this problem, but it has
5263 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5264 or better. If that isn't possible, there is a patch in
5265 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5266 around this problem.
5270 GDB now supports array constants that can be used in expressions typed in by
5271 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5272 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5275 The new directory `gdb/sparclite' contains a program that demonstrates
5276 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5278 * New native hosts supported
5280 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5281 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5283 * New targets supported
5285 AMD 29k family via UDI a29k-amd-udi or udi29k
5287 * New file formats supported
5289 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5290 HPUX core files, and SCO 3.2v2 core files.
5294 Attaching to processes now works again; thanks for the many bug reports.
5296 We have also stomped on a bunch of core dumps caused by
5297 printf_filtered("%s") problems.
5299 We eliminated a copyright problem on the rpc and ptrace header files
5300 for VxWorks, which was discovered at the last minute during the 4.7
5301 release. You should now be able to build a VxWorks GDB.
5303 You can now interrupt gdb while an attached process is running. This
5304 will cause the attached process to stop, and give control back to GDB.
5306 We fixed problems caused by using too many file descriptors
5307 for reading symbols from object files and libraries. This was
5308 especially a problem for programs that used many (~100) shared
5311 The `step' command now only enters a subroutine if there is line number
5312 information for the subroutine. Otherwise it acts like the `next'
5313 command. Previously, `step' would enter subroutines if there was
5314 any debugging information about the routine. This avoids problems
5315 when using `cc -g1' on MIPS machines.
5317 * Internal improvements
5319 GDB's internal interfaces have been improved to make it easier to support
5320 debugging of multiple languages in the future.
5322 GDB now uses a common structure for symbol information internally.
5323 Minimal symbols (derived from linkage symbols in object files), partial
5324 symbols (from a quick scan of debug information), and full symbols
5325 contain a common subset of information, making it easier to write
5326 shared code that handles any of them.
5328 * New command line options
5330 We now accept --silent as an alias for --quiet.
5334 The memory-mapped-malloc library is now licensed under the GNU Library
5335 General Public License.
5337 *** Changes in GDB-4.7:
5339 * Host/native/target split
5341 GDB has had some major internal surgery to untangle the support for
5342 hosts and remote targets. Now, when you configure GDB for a remote
5343 target, it will no longer load in all of the support for debugging
5344 local programs on the host. When fully completed and tested, this will
5345 ensure that arbitrary host/target combinations are possible.
5347 The primary conceptual shift is to separate the non-portable code in
5348 GDB into three categories. Host specific code is required any time GDB
5349 is compiled on that host, regardless of the target. Target specific
5350 code relates to the peculiarities of the target, but can be compiled on
5351 any host. Native specific code is everything else: it can only be
5352 built when the host and target are the same system. Child process
5353 handling and core file support are two common `native' examples.
5355 GDB's use of /proc for controlling Unix child processes is now cleaner.
5356 It has been split out into a single module under the `target_ops' vector,
5357 plus two native-dependent functions for each system that uses /proc.
5359 * New hosts supported
5361 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5362 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5363 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5365 * New targets supported
5367 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5368 68030 and CPU32 m68030-*-*, m68332-*-*
5370 * New native hosts supported
5372 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5373 (386bsd is not well tested yet)
5374 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5376 * New file formats supported
5378 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5379 supports reading of `a.out.adobe' object files, which are an a.out
5380 format extended with minimal information about multiple sections.
5384 `show copying' is the same as the old `info copying'.
5385 `show warranty' is the same as `info warrantee'.
5386 These were renamed for consistency. The old commands continue to work.
5388 `info handle' is a new alias for `info signals'.
5390 You can now define pre-command hooks, which attach arbitrary command
5391 scripts to any command. The commands in the hook will be executed
5392 prior to the user's command. You can also create a hook which will be
5393 executed whenever the program stops. See gdb.texinfo.
5397 We now deal with Cfront style name mangling, and can even extract type
5398 info from mangled symbols. GDB can automatically figure out which
5399 symbol mangling style your C++ compiler uses.
5401 Calling of methods and virtual functions has been improved as well.
5405 The crash that occured when debugging Sun Ansi-C compiled binaries is
5406 fixed. This was due to mishandling of the extra N_SO stabs output
5409 We also finally got Ultrix 4.2 running in house, and fixed core file
5410 support, with help from a dozen people on the net.
5412 John M. Farrell discovered that the reason that single-stepping was so
5413 slow on all of the Mips based platforms (primarily SGI and DEC) was
5414 that we were trying to demangle and lookup a symbol used for internal
5415 purposes on every instruction that was being stepped through. Changing
5416 the name of that symbol so that it couldn't be mistaken for a C++
5417 mangled symbol sped things up a great deal.
5419 Rich Pixley sped up symbol lookups in general by getting much smarter
5420 about when C++ symbol mangling is necessary. This should make symbol
5421 completion (TAB on the command line) much faster. It's not as fast as
5422 we'd like, but it's significantly faster than gdb-4.6.
5426 A new user controllable variable 'call_scratch_address' can
5427 specify the location of a scratch area to be used when GDB
5428 calls a function in the target. This is necessary because the
5429 usual method of putting the scratch area on the stack does not work
5430 in systems that have separate instruction and data spaces.
5432 We integrated changes to support the 29k UDI (Universal Debugger
5433 Interface), but discovered at the last minute that we didn't have all
5434 of the appropriate copyright paperwork. We are working with AMD to
5435 resolve this, and hope to have it available soon.
5439 We have sped up the remote serial line protocol, especially for targets
5440 with lots of registers. It now supports a new `expedited status' ('T')
5441 message which can be used in place of the existing 'S' status message.
5442 This allows the remote stub to send only the registers that GDB
5443 needs to make a quick decision about single-stepping or conditional
5444 breakpoints, eliminating the need to fetch the entire register set for
5445 each instruction being stepped through.
5447 The GDB remote serial protocol now implements a write-through cache for
5448 registers, only re-reading the registers if the target has run.
5450 There is also a new remote serial stub for SPARC processors. You can
5451 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5452 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5453 processor with a serial port.
5457 Configure.in files have become much easier to read and modify. A new
5458 `table driven' format makes it more obvious what configurations are
5459 supported, and what files each one uses.
5463 There is a new opcodes library which will eventually contain all of the
5464 disassembly routines and opcode tables. At present, it only contains
5465 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5466 disassembler (binutils/objdump) to share these routines.
5468 The libiberty library is now copylefted under the GNU Library General
5469 Public License. This allows more liberal use, and was done so libg++
5470 can use it. This makes no difference to GDB, since the Library License
5471 grants all the rights from the General Public License.
5475 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5476 reference to the stabs symbol info used by the debugger. It is (as far
5477 as we know) the only published document on this fascinating topic. We
5478 encourage you to read it, compare it to the stabs information on your
5479 system, and send improvements on the document in general (to
5480 bug-gdb@prep.ai.mit.edu).
5482 And, of course, many bugs have been fixed.
5485 *** Changes in GDB-4.6:
5487 * Better support for C++ function names
5489 GDB now accepts as input the "demangled form" of C++ overloaded function
5490 names and member function names, and can do command completion on such names
5491 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5492 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5493 Make use of command completion, it is your friend.
5495 GDB also now accepts a variety of C++ mangled symbol formats. They are
5496 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5497 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5498 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5499 for the list of formats.
5501 * G++ symbol mangling problem
5503 Recent versions of gcc have a bug in how they emit debugging information for
5504 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5505 directory) can be applied to gcc to fix the problem. Alternatively, if you
5506 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5507 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5508 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5511 * New 'maintenance' command
5513 All of the commands related to hacking GDB internals have been moved out of
5514 the main command set, and now live behind the 'maintenance' command. This
5515 can also be abbreviated as 'mt'. The following changes were made:
5517 dump-me -> maintenance dump-me
5518 info all-breakpoints -> maintenance info breakpoints
5519 printmsyms -> maintenance print msyms
5520 printobjfiles -> maintenance print objfiles
5521 printpsyms -> maintenance print psymbols
5522 printsyms -> maintenance print symbols
5524 The following commands are new:
5526 maintenance demangle Call internal GDB demangler routine to
5527 demangle a C++ link name and prints the result.
5528 maintenance print type Print a type chain for a given symbol
5530 * Change to .gdbinit file processing
5532 We now read the $HOME/.gdbinit file before processing the argv arguments
5533 (e.g. reading symbol files or core files). This allows global parameters to
5534 be set, which will apply during the symbol reading. The ./.gdbinit is still
5535 read after argv processing.
5537 * New hosts supported
5539 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5541 GNU/Linux support i386-unknown-linux or linux
5543 We are also including code to support the HP/PA running BSD and HPUX. This
5544 is almost guaranteed not to work, as we didn't have time to test or build it
5545 for this release. We are including it so that the more adventurous (or
5546 masochistic) of you can play with it. We also had major problems with the
5547 fact that the compiler that we got from HP doesn't support the -g option.
5550 * New targets supported
5552 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5554 * More smarts about finding #include files
5556 GDB now remembers the compilation directory for all include files, and for
5557 all files from which C is generated (like yacc and lex sources). This
5558 greatly improves GDB's ability to find yacc/lex sources, and include files,
5559 especially if you are debugging your program from a directory different from
5560 the one that contains your sources.
5562 We also fixed a bug which caused difficulty with listing and setting
5563 breakpoints in include files which contain C code. (In the past, you had to
5564 try twice in order to list an include file that you hadn't looked at before.)
5566 * Interesting infernals change
5568 GDB now deals with arbitrary numbers of sections, where the symbols for each
5569 section must be relocated relative to that section's landing place in the
5570 target's address space. This work was needed to support ELF with embedded
5571 stabs used by Solaris-2.0.
5573 * Bug fixes (of course!)
5575 There have been loads of fixes for the following things:
5576 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5577 i960, stabs, DOS(GO32), procfs, etc...
5579 See the ChangeLog for details.
5581 *** Changes in GDB-4.5:
5583 * New machines supported (host and target)
5585 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5587 SGI Irix-4.x mips-sgi-irix4 or iris4
5589 * New malloc package
5591 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5592 Mmalloc is capable of handling mutiple heaps of memory. It is also
5593 capable of saving a heap to a file, and then mapping it back in later.
5594 This can be used to greatly speedup the startup of GDB by using a
5595 pre-parsed symbol table which lives in a mmalloc managed heap. For
5596 more details, please read mmalloc/mmalloc.texi.
5600 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5601 'help info proc' for details.
5603 * MIPS ecoff symbol table format
5605 The code that reads MIPS symbol table format is now supported on all hosts.
5606 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5609 * File name changes for MS-DOS
5611 Many files in the config directories have been renamed to make it easier to
5612 support GDB on MS-DOSe systems (which have very restrictive file name
5613 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5614 environment) is close to working but has some remaining problems. Note
5615 that debugging of DOS programs is not supported, due to limitations
5616 in the ``operating system'', but it can be used to host cross-debugging.
5618 * Cross byte order fixes
5620 Many fixes have been made to support cross debugging of Sparc and MIPS
5621 targets from hosts whose byte order differs.
5623 * New -mapped and -readnow options
5625 If memory-mapped files are available on your system through the 'mmap'
5626 system call, you can use the -mapped option on the `file' or
5627 `symbol-file' commands to cause GDB to write the symbols from your
5628 program into a reusable file. If the program you are debugging is
5629 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5630 Future GDB debugging sessions will notice the presence of this file,
5631 and will quickly map in symbol information from it, rather than reading
5632 the symbol table from the executable program. Using the '-mapped'
5633 option in a GDB `file' or `symbol-file' command has the same effect as
5634 starting GDB with the '-mapped' command-line option.
5636 You can cause GDB to read the entire symbol table immediately by using
5637 the '-readnow' option with any of the commands that load symbol table
5638 information (or on the GDB command line). This makes the command
5639 slower, but makes future operations faster.
5641 The -mapped and -readnow options are typically combined in order to
5642 build a `fred.syms' file that contains complete symbol information.
5643 A simple GDB invocation to do nothing but build a `.syms' file for future
5646 gdb -batch -nx -mapped -readnow programname
5648 The `.syms' file is specific to the host machine on which GDB is run.
5649 It holds an exact image of GDB's internal symbol table. It cannot be
5650 shared across multiple host platforms.
5652 * longjmp() handling
5654 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5655 siglongjmp() without losing control. This feature has not yet been ported to
5656 all systems. It currently works on many 386 platforms, all MIPS-based
5657 platforms (SGI, DECstation, etc), and Sun3/4.
5661 Preliminary work has been put in to support the new Solaris OS from Sun. At
5662 this time, it can control and debug processes, but it is not capable of
5667 As always, many many bug fixes. The major areas were with g++, and mipsread.
5668 People using the MIPS-based platforms should experience fewer mysterious
5669 crashes and trashed symbol tables.
5671 *** Changes in GDB-4.4:
5673 * New machines supported (host and target)
5675 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5677 BSD Reno on Vax vax-dec-bsd
5678 Ultrix on Vax vax-dec-ultrix
5680 * New machines supported (target)
5682 AMD 29000 embedded, using EBMON a29k-none-none
5686 GDB continues to improve its handling of C++. `References' work better.
5687 The demangler has also been improved, and now deals with symbols mangled as
5688 per the Annotated C++ Reference Guide.
5690 GDB also now handles `stabs' symbol information embedded in MIPS
5691 `ecoff' symbol tables. Since the ecoff format was not easily
5692 extensible to handle new languages such as C++, this appeared to be a
5693 good way to put C++ debugging info into MIPS binaries. This option
5694 will be supported in the GNU C compiler, version 2, when it is
5697 * New features for SVR4
5699 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5700 shared libraries. Debugging dynamically linked programs should present
5701 only minor differences from debugging statically linked programs.
5703 The `info proc' command will print out information about any process
5704 on an SVR4 system (including the one you are debugging). At the moment,
5705 it prints the address mappings of the process.
5707 If you bring up GDB on another SVR4 system, please send mail to
5708 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5710 * Better dynamic linking support in SunOS
5712 Reading symbols from shared libraries which contain debugging symbols
5713 now works properly. However, there remain issues such as automatic
5714 skipping of `transfer vector' code during function calls, which
5715 make it harder to debug code in a shared library, than to debug the
5716 same code linked statically.
5720 GDB is now using the latest `getopt' routines from the FSF. This
5721 version accepts the -- prefix for options with long names. GDB will
5722 continue to accept the old forms (-option and +option) as well.
5723 Various single letter abbreviations for options have been explicity
5724 added to the option table so that they won't get overshadowed in the
5725 future by other options that begin with the same letter.
5729 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5730 Many assorted bugs have been handled. Many more remain to be handled.
5731 See the various ChangeLog files (primarily in gdb and bfd) for details.
5734 *** Changes in GDB-4.3:
5736 * New machines supported (host and target)
5738 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5739 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5740 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5742 * Almost SCO Unix support
5744 We had hoped to support:
5745 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5746 (except for core file support), but we discovered very late in the release
5747 that it has problems with process groups that render gdb unusable. Sorry
5748 about that. I encourage people to fix it and post the fixes.
5750 * Preliminary ELF and DWARF support
5752 GDB can read ELF object files on System V Release 4, and can handle
5753 debugging records for C, in DWARF format, in ELF files. This support
5754 is preliminary. If you bring up GDB on another SVR4 system, please
5755 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5760 GDB now uses the latest `readline' library. One user-visible change
5761 is that two tabs will list possible command completions, which previously
5762 required typing M-? (meta-question mark, or ESC ?).
5766 The `stepi' bug that many of you noticed has been squashed.
5767 Many bugs in C++ have been handled. Many more remain to be handled.
5768 See the various ChangeLog files (primarily in gdb and bfd) for details.
5770 * State of the MIPS world (in case you wondered):
5772 GDB can understand the symbol tables emitted by the compilers
5773 supplied by most vendors of MIPS-based machines, including DEC. These
5774 symbol tables are in a format that essentially nobody else uses.
5776 Some versions of gcc come with an assembler post-processor called
5777 mips-tfile. This program is required if you want to do source-level
5778 debugging of gcc-compiled programs. I believe FSF does not ship
5779 mips-tfile with gcc version 1, but it will eventually come with gcc
5782 Debugging of g++ output remains a problem. g++ version 1.xx does not
5783 really support it at all. (If you're lucky, you should be able to get
5784 line numbers and stack traces to work, but no parameters or local
5785 variables.) With some work it should be possible to improve the
5788 When gcc version 2 is released, you will have somewhat better luck.
5789 However, even then you will get confusing results for inheritance and
5792 We will eventually provide full debugging of g++ output on
5793 DECstations. This will probably involve some kind of stabs-in-ecoff
5794 encapulation, but the details have not been worked out yet.
5797 *** Changes in GDB-4.2:
5799 * Improved configuration
5801 Only one copy of `configure' exists now, and it is not self-modifying.
5802 Porting BFD is simpler.
5806 The `step' and `next' commands now only stop at the first instruction
5807 of a source line. This prevents the multiple stops that used to occur
5808 in switch statements, for-loops, etc. `Step' continues to stop if a
5809 function that has debugging information is called within the line.
5813 Lots of small bugs fixed. More remain.
5815 * New host supported (not target)
5817 Intel 386 PC clone running Mach i386-none-mach
5820 *** Changes in GDB-4.1:
5822 * Multiple source language support
5824 GDB now has internal scaffolding to handle several source languages.
5825 It determines the type of each source file from its filename extension,
5826 and will switch expression parsing and number formatting to match the
5827 language of the function in the currently selected stack frame.
5828 You can also specifically set the language to be used, with
5829 `set language c' or `set language modula-2'.
5833 GDB now has preliminary support for the GNU Modula-2 compiler,
5834 currently under development at the State University of New York at
5835 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5836 continue through the fall of 1991 and into 1992.
5838 Other Modula-2 compilers are currently not supported, and attempting to
5839 debug programs compiled with them will likely result in an error as the
5840 symbol table is read. Feel free to work on it, though!
5842 There are hooks in GDB for strict type checking and range checking,
5843 in the `Modula-2 philosophy', but they do not currently work.
5847 GDB can now write to executable and core files (e.g. patch
5848 a variable's value). You must turn this switch on, specify
5849 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5850 by assigning a new value to a variable. Modifications take
5853 * Automatic SunOS shared library reading
5855 When you run your program, GDB automatically determines where its
5856 shared libraries (if any) have been loaded, and reads their symbols.
5857 The `share' command is no longer needed. This also works when
5858 examining core files.
5862 You can specify the number of lines that the `list' command shows.
5865 * New machines supported (host and target)
5867 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5868 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5869 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5871 * New hosts supported (not targets)
5873 IBM RT/PC: romp-ibm-aix or rtpc
5875 * New targets supported (not hosts)
5877 AMD 29000 embedded with COFF a29k-none-coff
5878 AMD 29000 embedded with a.out a29k-none-aout
5879 Ultracomputer remote kernel debug a29k-nyu-kern
5881 * New remote interfaces
5887 *** Changes in GDB-4.0:
5891 Wide output is wrapped at good places to make the output more readable.
5893 Gdb now supports cross-debugging from a host machine of one type to a
5894 target machine of another type. Communication with the target system
5895 is over serial lines. The ``target'' command handles connecting to the
5896 remote system; the ``load'' command will download a program into the
5897 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5898 also supports debugging of realtime processes running under VxWorks,
5899 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5900 stub on the target system.
5902 New CPUs supported include the AMD 29000 and Intel 960.
5904 GDB now reads object files and symbol tables via a ``binary file''
5905 library, which allows a single copy of GDB to debug programs of multiple
5906 object file types such as a.out and coff.
5908 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5909 refcard.dvi and refcard.ps are available to format it).
5912 * Control-Variable user interface simplified
5914 All variables that control the operation of the debugger can be set
5915 by the ``set'' command, and displayed by the ``show'' command.
5917 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5918 ``Show prompt'' produces the response:
5919 Gdb's prompt is new-gdb=>.
5921 What follows are the NEW set commands. The command ``help set'' will
5922 print a complete list of old and new set commands. ``help set FOO''
5923 will give a longer description of the variable FOO. ``show'' will show
5924 all of the variable descriptions and their current settings.
5926 confirm on/off: Enables warning questions for operations that are
5927 hard to recover from, e.g. rerunning the program while
5928 it is already running. Default is ON.
5930 editing on/off: Enables EMACS style command line editing
5931 of input. Previous lines can be recalled with
5932 control-P, the current line can be edited with control-B,
5933 you can search for commands with control-R, etc.
5936 history filename NAME: NAME is where the gdb command history
5937 will be stored. The default is .gdb_history,
5938 or the value of the environment variable
5941 history size N: The size, in commands, of the command history. The
5942 default is 256, or the value of the environment variable
5945 history save on/off: If this value is set to ON, the history file will
5946 be saved after exiting gdb. If set to OFF, the
5947 file will not be saved. The default is OFF.
5949 history expansion on/off: If this value is set to ON, then csh-like
5950 history expansion will be performed on
5951 command line input. The default is OFF.
5953 radix N: Sets the default radix for input and output. It can be set
5954 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5955 in the current radix, so "set radix 10" is always a no-op.
5957 height N: This integer value is the number of lines on a page. Default
5958 is 24, the current `stty rows'' setting, or the ``li#''
5959 setting from the termcap entry matching the environment
5962 width N: This integer value is the number of characters on a line.
5963 Default is 80, the current `stty cols'' setting, or the ``co#''
5964 setting from the termcap entry matching the environment
5967 Note: ``set screensize'' is obsolete. Use ``set height'' and
5968 ``set width'' instead.
5970 print address on/off: Print memory addresses in various command displays,
5971 such as stack traces and structure values. Gdb looks
5972 more ``symbolic'' if you turn this off; it looks more
5973 ``machine level'' with it on. Default is ON.
5975 print array on/off: Prettyprint arrays. New convenient format! Default
5978 print demangle on/off: Print C++ symbols in "source" form if on,
5981 print asm-demangle on/off: Same, for assembler level printouts
5984 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5987 * Support for Epoch Environment.
5989 The epoch environment is a version of Emacs v18 with windowing. One
5990 new command, ``inspect'', is identical to ``print'', except that if you
5991 are running in the epoch environment, the value is printed in its own
5995 * Support for Shared Libraries
5997 GDB can now debug programs and core files that use SunOS shared libraries.
5998 Symbols from a shared library cannot be referenced
5999 before the shared library has been linked with the program (this
6000 happens after you type ``run'' and before the function main() is entered).
6001 At any time after this linking (including when examining core files
6002 from dynamically linked programs), gdb reads the symbols from each
6003 shared library when you type the ``sharedlibrary'' command.
6004 It can be abbreviated ``share''.
6006 sharedlibrary REGEXP: Load shared object library symbols for files
6007 matching a unix regular expression. No argument
6008 indicates to load symbols for all shared libraries.
6010 info sharedlibrary: Status of loaded shared libraries.
6015 A watchpoint stops execution of a program whenever the value of an
6016 expression changes. Checking for this slows down execution
6017 tremendously whenever you are in the scope of the expression, but is
6018 quite useful for catching tough ``bit-spreader'' or pointer misuse
6019 problems. Some machines such as the 386 have hardware for doing this
6020 more quickly, and future versions of gdb will use this hardware.
6022 watch EXP: Set a watchpoint (breakpoint) for an expression.
6024 info watchpoints: Information about your watchpoints.
6026 delete N: Deletes watchpoint number N (same as breakpoints).
6027 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6028 enable N: Re-enables watchpoint number N (same as breakpoints).
6031 * C++ multiple inheritance
6033 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6036 * C++ exception handling
6038 Gdb now supports limited C++ exception handling. Besides the existing
6039 ability to breakpoint on an exception handler, gdb can breakpoint on
6040 the raising of an exception (before the stack is peeled back to the
6043 catch FOO: If there is a FOO exception handler in the dynamic scope,
6044 set a breakpoint to catch exceptions which may be raised there.
6045 Multiple exceptions (``catch foo bar baz'') may be caught.
6047 info catch: Lists all exceptions which may be caught in the
6048 current stack frame.
6051 * Minor command changes
6053 The command ``call func (arg, arg, ...)'' now acts like the print
6054 command, except it does not print or save a value if the function's result
6055 is void. This is similar to dbx usage.
6057 The ``up'' and ``down'' commands now always print the frame they end up
6058 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6059 frames without printing.
6061 * New directory command
6063 'dir' now adds directories to the FRONT of the source search path.
6064 The path starts off empty. Source files that contain debug information
6065 about the directory in which they were compiled can be found even
6066 with an empty path; Sun CC and GCC include this information. If GDB can't
6067 find your source file in the current directory, type "dir .".
6069 * Configuring GDB for compilation
6071 For normal use, type ``./configure host''. See README or gdb.texinfo
6074 GDB now handles cross debugging. If you are remotely debugging between
6075 two different machines, type ``./configure host -target=targ''.
6076 Host is the machine where GDB will run; targ is the machine
6077 where the program that you are debugging will run.