1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.9
6 * GDB now honors the content of the file /proc/PID/coredump_filter
7 (PID is the process ID) on GNU/Linux systems. This file can be used
8 to specify the types of memory mappings that will be included in a
9 corefile. For more information, please refer to the manual page of
10 "core(5)". GDB also has a new command: "set use-coredump-filter
11 on|off". It allows to set whether GDB will read the content of the
12 /proc/PID/coredump_filter file when generating a corefile.
14 * The "info os" command on GNU/Linux can now display information on
16 "info os cpus" Listing of all cpus/cores on the system
18 * GDB has two new commands: "set serial parity odd|even|none" and
19 "show serial parity". These allows to set or show parity for the
22 * The "info source" command now displays the producer string if it was
23 present in the debug info. This typically includes the compiler version
24 and may include things like its command line arguments.
26 * The "info dll", an alias of the "info sharedlibrary" command,
27 is now available on all platforms.
29 * Directory names supplied to the "set sysroot" commands may be
30 prefixed with "target:" to tell GDB to access shared libraries from
31 the target system, be it local or remote. This replaces the prefix
32 "remote:". The default sysroot has been changed from "" to
33 "target:". "remote:" is automatically converted to "target:" for
34 backward compatibility.
36 * The system root specified by "set sysroot" will be prepended to the
37 filename of the main executable (if reported to GDB as absolute by
38 the operating system) when starting processes remotely, and when
39 attaching to already-running local or remote processes.
41 * GDB now supports automatic location and retrieval of executable
42 files from remote targets. Remote debugging can now be initiated
43 using only a "target remote" or "target extended-remote" command
44 (no "set sysroot" or "file" commands are required). See "New remote
47 * The "dump" command now supports verilog hex format.
49 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
53 ** gdb.Objfile objects have a new attribute "username",
54 which is the name of the objfile as specified by the user,
55 without, for example, resolving symlinks.
56 ** You can now write frame unwinders in Python.
57 ** gdb.Type objects have a new method "optimized_out",
58 returning optimized out gdb.Value instance of this type.
59 ** gdb.Value objects have new methods "reference_value" and
60 "const_value" which return a reference to the value and a
61 "const" version of the value respectively.
65 maint print symbol-cache
66 Print the contents of the symbol cache.
68 maint print symbol-cache-statistics
69 Print statistics of symbol cache usage.
71 maint flush-symbol-cache
72 Flush the contents of the symbol cache.
76 Start branch trace recording using Branch Trace Store (BTS) format.
82 Set the maximum number of candidates to be considered during
83 completion. The default value is 200. This limit allows GDB
84 to avoid generating large completion lists, the computation of
85 which can cause the debugger to become temporarily unresponsive.
87 maint set symbol-cache-size
88 maint show symbol-cache-size
89 Control the size of the symbol cache.
91 set|show record btrace bts buffer-size
92 Set and show the size of the ring buffer used for branch tracing in
94 The obtained size may differ from the requested size. Use "info
95 record" to see the obtained buffer size.
97 * The command 'thread apply all' can now support new option '-ascending'
98 to call its specified command for all threads in ascending order.
100 * Python/Guile scripting
102 ** GDB now supports auto-loading of Python/Guile scripts contained in the
103 special section named `.debug_gdb_scripts'.
107 qXfer:btrace-conf:read
108 Return the branch trace configuration for the current thread.
110 Qbtrace-conf:bts:size
111 Set the requested ring buffer size for branch tracing in BTS format.
114 Indicates a memory breakpoint instruction was executed, irrespective
115 of whether it was GDB that planted the breakpoint or the breakpoint
116 is hardcoded in the program. This is required for correct non-stop
120 Indicates the target stopped for a hardware breakpoint. This is
121 required for correct non-stop mode operation.
124 Return information about files on the remote system.
127 Return the full absolute name of the file that was executed to
128 create a process running on the remote system.
131 Indicates that a fork system call was executed.
134 Indicates that a vfork system call was executed.
136 vforkdone stop reason
137 Indicates that a vfork child of the specified process has executed
138 an exec or exit, allowing the vfork parent to resume execution.
140 fork-events and vfork-events features in qSupported
141 The qSupported packet allows GDB to request support for fork and
142 vfork events using new 'gdbfeatures' fork-events and vfork-events,
143 and the qSupported response can contain the corresponding
144 'stubfeatures'. Set and show commands can be used to display
145 whether these features are enabled.
147 * Extended-remote fork events
149 ** GDB now has support for fork events on extended-remote Linux
150 targets. For targets with Linux kernels 2.5.60 and later, this
151 enables follow-fork-mode and detach-on-fork for both fork and
152 vfork, as well as fork and vfork catchpoints.
154 * The info record command now shows the recording format and the
155 branch tracing configuration for the current thread when using
156 the btrace record target.
157 For the BTS format, it shows the ring buffer size.
159 * GDB now has support for DTrace USDT (Userland Static Defined
160 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
162 * GDB now supports access to vector registers on S/390 GNU/Linux
165 * Removed command line options
167 -xdb HP-UX XDB compatibility mode.
169 * Removed targets and native configurations
171 HP/PA running HP-UX hppa*-*-hpux*
172 Itanium running HP-UX ia64-*-hpux*
174 *** Changes in GDB 7.9.1
178 ** Xmethods can now specify a result type.
180 *** Changes in GDB 7.9
182 * GDB now supports hardware watchpoints on x86 GNU Hurd.
186 ** You can now access frame registers from Python scripts.
187 ** New attribute 'producer' for gdb.Symtab objects.
188 ** gdb.Objfile objects have a new attribute "progspace",
189 which is the gdb.Progspace object of the containing program space.
190 ** gdb.Objfile objects have a new attribute "owner".
191 ** gdb.Objfile objects have a new attribute "build_id",
192 which is the build ID generated when the file was built.
193 ** gdb.Objfile objects have a new method "add_separate_debug_file".
194 ** A new event "gdb.clear_objfiles" has been added, triggered when
195 selecting a new file to debug.
196 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
197 ** New function gdb.lookup_objfile.
199 New events which are triggered when GDB modifies the state of the
202 ** gdb.events.inferior_call_pre: Function call is about to be made.
203 ** gdb.events.inferior_call_post: Function call has just been made.
204 ** gdb.events.memory_changed: A memory location has been altered.
205 ** gdb.events.register_changed: A register has been altered.
207 * New Python-based convenience functions:
209 ** $_caller_is(name [, number_of_frames])
210 ** $_caller_matches(regexp [, number_of_frames])
211 ** $_any_caller_is(name [, number_of_frames])
212 ** $_any_caller_matches(regexp [, number_of_frames])
214 * GDB now supports the compilation and injection of source code into
215 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
216 to compile the source code to object code, and if successful, inject
217 and execute that code within the current context of the inferior.
218 Currently the C language is supported. The commands used to
219 interface with this new feature are:
221 compile code [-raw|-r] [--] [source code]
222 compile file [-raw|-r] filename
226 demangle [-l language] [--] name
227 Demangle "name" in the specified language, or the current language
228 if elided. This command is renamed from the "maint demangle" command.
229 The latter is kept as a no-op to avoid "maint demangle" being interpreted
230 as "maint demangler-warning".
232 queue-signal signal-name-or-number
233 Queue a signal to be delivered to the thread when it is resumed.
235 add-auto-load-scripts-directory directory
236 Add entries to the list of directories from which to load auto-loaded
239 maint print user-registers
240 List all currently available "user" registers.
242 compile code [-r|-raw] [--] [source code]
243 Compile, inject, and execute in the inferior the executable object
244 code produced by compiling the provided source code.
246 compile file [-r|-raw] filename
247 Compile and inject into the inferior the executable object code
248 produced by compiling the source code stored in the filename
251 * On resume, GDB now always passes the signal the program had stopped
252 for to the thread the signal was sent to, even if the user changed
253 threads before resuming. Previously GDB would often (but not
254 always) deliver the signal to the thread that happens to be current
257 * Conversely, the "signal" command now consistently delivers the
258 requested signal to the current thread. GDB now asks for
259 confirmation if the program had stopped for a signal and the user
260 switched threads meanwhile.
262 * "breakpoint always-inserted" modes "off" and "auto" merged.
264 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
265 won't remove breakpoints from the target until all threads stop,
266 even in non-stop mode. The "auto" mode has been removed, and "off"
267 is now the default mode.
271 set debug symbol-lookup
272 show debug symbol-lookup
273 Control display of debugging info regarding symbol lookup.
277 ** The -list-thread-groups command outputs an exit-code field for
278 inferiors that have exited.
282 MIPS SDE mips*-sde*-elf*
286 Support for these obsolete configurations has been removed.
288 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
289 SGI Irix-5.x mips-*-irix5*
290 SGI Irix-6.x mips-*-irix6*
291 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
292 VAX running Ultrix vax-*-ultrix*
294 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
295 and "assf"), have been removed. Use the "sharedlibrary" command, or
296 its alias "share", instead.
298 *** Changes in GDB 7.8
300 * New command line options
303 This is an alias for the --data-directory option.
305 * GDB supports printing and modifying of variable length automatic arrays
306 as specified in ISO C99.
308 * The ARM simulator now supports instruction level tracing
309 with or without disassembly.
313 GDB now has support for scripting using Guile. Whether this is
314 available is determined at configure time.
315 Guile version 2.0 or greater is required.
316 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
318 * New commands (for set/show, see "New options" below)
322 Invoke CODE by passing it to the Guile interpreter.
326 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
328 info auto-load guile-scripts [regexp]
329 Print the list of automatically loaded Guile scripts.
331 * The source command is now capable of sourcing Guile scripts.
332 This feature is dependent on the debugger being built with Guile support.
336 set print symbol-loading (off|brief|full)
337 show print symbol-loading
338 Control whether to print informational messages when loading symbol
339 information for a file. The default is "full", but when debugging
340 programs with large numbers of shared libraries the amount of output
343 set guile print-stack (none|message|full)
344 show guile print-stack
345 Show a stack trace when an error is encountered in a Guile script.
347 set auto-load guile-scripts (on|off)
348 show auto-load guile-scripts
349 Control auto-loading of Guile script files.
351 maint ada set ignore-descriptive-types (on|off)
352 maint ada show ignore-descriptive-types
353 Control whether the debugger should ignore descriptive types in Ada
354 programs. The default is not to ignore the descriptive types. See
355 the user manual for more details on descriptive types and the intended
356 usage of this option.
358 set auto-connect-native-target
360 Control whether GDB is allowed to automatically connect to the
361 native target for the run, attach, etc. commands when not connected
362 to any target yet. See also "target native" below.
364 set record btrace replay-memory-access (read-only|read-write)
365 show record btrace replay-memory-access
366 Control what memory accesses are allowed during replay.
368 maint set target-async (on|off)
369 maint show target-async
370 This controls whether GDB targets operate in synchronous or
371 asynchronous mode. Normally the default is asynchronous, if it is
372 available; but this can be changed to more easily debug problems
373 occurring only in synchronous mode.
375 set mi-async (on|off)
377 Control whether MI asynchronous mode is preferred. This supersedes
378 "set target-async" of previous GDB versions.
380 * "set target-async" is deprecated as a CLI option and is now an alias
381 for "set mi-async" (only puts MI into async mode).
383 * Background execution commands (e.g., "c&", "s&", etc.) are now
384 possible ``out of the box'' if the target supports them. Previously
385 the user would need to explicitly enable the possibility with the
386 "set target-async on" command.
388 * New features in the GDB remote stub, GDBserver
390 ** New option --debug-format=option1[,option2,...] allows one to add
391 additional text to each output. At present only timestamps
392 are supported: --debug-format=timestamps.
393 Timestamps can also be turned on with the
394 "monitor set debug-format timestamps" command from GDB.
396 * The 'record instruction-history' command now starts counting instructions
397 at one. This also affects the instruction ranges reported by the
398 'record function-call-history' command when given the /i modifier.
400 * The command 'record function-call-history' supports a new modifier '/c' to
401 indent the function names based on their call stack depth.
402 The fields for the '/i' and '/l' modifier have been reordered.
403 The source line range is now prefixed with 'at'.
404 The instruction range is now prefixed with 'inst'.
405 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
406 "record instruction-history" and "list" commands.
408 * The ranges given as arguments to the 'record function-call-history' and
409 'record instruction-history' commands are now inclusive.
411 * The btrace record target now supports the 'record goto' command.
412 For locations inside the execution trace, the back trace is computed
413 based on the information stored in the execution trace.
415 * The btrace record target supports limited reverse execution and replay.
416 The target does not record data and therefore does not allow reading
419 * The "catch syscall" command now works on s390*-linux* targets.
421 * The "compare-sections" command is no longer specific to target
422 remote. It now works with all targets.
424 * All native targets are now consistently called "native".
425 Consequently, the "target child", "target GNU", "target djgpp",
426 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
427 commands have been replaced with "target native". The QNX/NTO port
428 leaves the "procfs" target in place and adds a "native" target for
429 consistency with other ports. The impact on users should be minimal
430 as these commands previously either throwed an error, or were
431 no-ops. The target's name is visible in the output of the following
432 commands: "help target", "info target", "info files", "maint print
435 * The "target native" command now connects to the native target. This
436 can be used to launch native programs even when "set
437 auto-connect-native-target" is set to off.
439 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.
441 * Support for Intel(R) AVX-512 registers on GNU/Linux.
442 Support displaying and modifying Intel(R) AVX-512 registers
443 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
447 qXfer:btrace:read's annex
448 The qXfer:btrace:read packet supports a new annex 'delta' to read
449 branch trace incrementally.
453 ** Valid Python operations on gdb.Value objects representing
454 structs/classes invoke the corresponding overloaded operators if
456 ** New `Xmethods' feature in the Python API. Xmethods are
457 additional methods or replacements for existing methods of a C++
458 class. This feature is useful for those cases where a method
459 defined in C++ source code could be inlined or optimized out by
460 the compiler, making it unavailable to GDB.
463 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
465 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
466 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
467 its alias "share", instead.
469 * The commands "set remotebaud" and "show remotebaud" are no longer
470 supported. Use "set serial baud" and "show serial baud" (respectively)
475 ** A new option "-gdb-set mi-async" replaces "-gdb-set
476 target-async". The latter is left as a deprecated alias of the
477 former for backward compatibility. If the target supports it,
478 CLI background execution commands are now always possible by
479 default, independently of whether the frontend stated a
480 preference for asynchronous execution with "-gdb-set mi-async".
481 Previously "-gdb-set target-async off" affected both MI execution
482 commands and CLI execution commands.
484 *** Changes in GDB 7.7
486 * Improved support for process record-replay and reverse debugging on
487 arm*-linux* targets. Support for thumb32 and syscall instruction
488 recording has been added.
490 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
492 * GDB now supports Fission DWP file format version 2.
493 http://gcc.gnu.org/wiki/DebugFission
495 * New convenience function "$_isvoid", to check whether an expression
496 is void. A void expression is an expression where the type of the
497 result is "void". For example, some convenience variables may be
498 "void" when evaluated (e.g., "$_exitcode" before the execution of
499 the program being debugged; or an undefined convenience variable).
500 Another example, when calling a function whose return type is
503 * The "maintenance print objfiles" command now takes an optional regexp.
505 * The "catch syscall" command now works on arm*-linux* targets.
507 * GDB now consistently shows "<not saved>" when printing values of
508 registers the debug info indicates have not been saved in the frame
509 and there's nowhere to retrieve them from
510 (callee-saved/call-clobbered registers):
515 (gdb) info registers rax
518 Before, the former would print "<optimized out>", and the latter
519 "*value not available*".
521 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
526 ** Frame filters and frame decorators have been added.
527 ** Temporary breakpoints are now supported.
528 ** Line tables representation has been added.
529 ** New attribute 'parent_type' for gdb.Field objects.
530 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
531 ** New attribute 'name' for gdb.Type objects.
535 Nios II ELF nios2*-*-elf
536 Nios II GNU/Linux nios2*-*-linux
537 Texas Instruments MSP430 msp430*-*-elf
539 * Removed native configurations
541 Support for these a.out NetBSD and OpenBSD obsolete configurations has
542 been removed. ELF variants of these configurations are kept supported.
544 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
545 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
546 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
547 i[34567]86-*-openbsd3.[0-3]
548 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
549 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
550 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
554 Like "catch throw", but catches a re-thrown exception.
556 Renamed from old "maint check-symtabs".
558 Perform consistency checks on symtabs.
560 Expand symtabs matching an optional regexp.
563 Display the details of GDB configure-time options.
565 maint set|show per-command
566 maint set|show per-command space
567 maint set|show per-command time
568 maint set|show per-command symtab
569 Enable display of per-command gdb resource usage.
571 remove-symbol-file FILENAME
572 remove-symbol-file -a ADDRESS
573 Remove a symbol file added via add-symbol-file. The file to remove
574 can be identified by its filename or by an address that lies within
575 the boundaries of this symbol file in memory.
578 info exceptions REGEXP
579 Display the list of Ada exceptions defined in the program being
580 debugged. If provided, only the exceptions whose names match REGEXP
585 set debug symfile off|on
587 Control display of debugging info regarding reading symbol files and
588 symbol tables within those files
590 set print raw frame-arguments
591 show print raw frame-arguments
592 Set/show whether to print frame arguments in raw mode,
593 disregarding any defined pretty-printers.
595 set remote trace-status-packet
596 show remote trace-status-packet
597 Set/show the use of remote protocol qTStatus packet.
601 Control display of debugging messages related to Nios II targets.
605 Control whether target-assisted range stepping is enabled.
607 set startup-with-shell
608 show startup-with-shell
609 Specifies whether Unix child processes are started via a shell or
614 Use the target memory cache for accesses to the code segment. This
615 improves performance of remote debugging (particularly disassembly).
617 * You can now use a literal value 'unlimited' for options that
618 interpret 0 or -1 as meaning "unlimited". E.g., "set
619 trace-buffer-size unlimited" is now an alias for "set
620 trace-buffer-size -1" and "set height unlimited" is now an alias for
623 * The "set debug symtab-create" debugging option of GDB has been changed to
624 accept a verbosity level. 0 means "off", 1 provides basic debugging
625 output, and values of 2 or greater provides more verbose output.
627 * New command-line options
629 Display the details of GDB configure-time options.
631 * The command 'tsave' can now support new option '-ctf' to save trace
632 buffer in Common Trace Format.
634 * Newly installed $prefix/bin/gcore acts as a shell interface for the
637 * GDB now implements the the C++ 'typeid' operator.
639 * The new convenience variable $_exception holds the exception being
640 thrown or caught at an exception-related catchpoint.
642 * The exception-related catchpoints, like "catch throw", now accept a
643 regular expression which can be used to filter exceptions by type.
645 * The new convenience variable $_exitsignal is automatically set to
646 the terminating signal number when the program being debugged dies
647 due to an uncaught signal.
651 ** All MI commands now accept an optional "--language" option.
652 Support for this feature can be verified by using the "-list-features"
653 command, which should contain "language-option".
655 ** The new command -info-gdb-mi-command allows the user to determine
656 whether a GDB/MI command is supported or not.
658 ** The "^error" result record returned when trying to execute an undefined
659 GDB/MI command now provides a variable named "code" whose content is the
660 "undefined-command" error code. Support for this feature can be verified
661 by using the "-list-features" command, which should contain
662 "undefined-command-error-code".
664 ** The -trace-save MI command can optionally save trace buffer in Common
667 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
669 ** The command -data-list-register-values now accepts an optional
670 "--skip-unavailable" option. When used, only the available registers
673 ** The new command -trace-frame-collected dumps collected variables,
674 computed expressions, tvars, memory and registers in a traceframe.
676 ** The commands -stack-list-locals, -stack-list-arguments and
677 -stack-list-variables now accept an option "--skip-unavailable".
678 When used, only the available locals or arguments are displayed.
680 ** The -exec-run command now accepts an optional "--start" option.
681 When used, the command follows the same semantics as the "start"
682 command, stopping the program's execution at the start of its
683 main subprogram. Support for this feature can be verified using
684 the "-list-features" command, which should contain
685 "exec-run-start-option".
687 ** The new commands -catch-assert and -catch-exceptions insert
688 catchpoints stopping the program when Ada exceptions are raised.
690 ** The new command -info-ada-exceptions provides the equivalent of
691 the new "info exceptions" command.
693 * New system-wide configuration scripts
694 A GDB installation now provides scripts suitable for use as system-wide
695 configuration scripts for the following systems:
699 * GDB now supports target-assigned range stepping with remote targets.
700 This improves the performance of stepping source lines by reducing
701 the number of control packets from/to GDB. See "New remote packets"
704 * GDB now understands the element 'tvar' in the XML traceframe info.
705 It has the id of the collected trace state variables.
707 * On S/390 targets that provide the transactional-execution feature,
708 the program interruption transaction diagnostic block (TDB) is now
709 represented as a number of additional "registers" in GDB.
715 The vCont packet supports a new 'r' action, that tells the remote
716 stub to step through an address range itself, without GDB
717 involvemement at each single-step.
719 qXfer:libraries-svr4:read's annex
720 The previously unused annex of the qXfer:libraries-svr4:read packet
721 is now used to support passing an argument list. The remote stub
722 reports support for this argument list to GDB's qSupported query.
723 The defined arguments are "start" and "prev", used to reduce work
724 necessary for library list updating, resulting in significant
727 * New features in the GDB remote stub, GDBserver
729 ** GDBserver now supports target-assisted range stepping. Currently
730 enabled on x86/x86_64 GNU/Linux targets.
732 ** GDBserver now adds element 'tvar' in the XML in the reply to
733 'qXfer:traceframe-info:read'. It has the id of the collected
734 trace state variables.
736 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
739 * New 'z' formatter for printing and examining memory, this displays the
740 value as hexadecimal zero padded on the left to the size of the type.
742 * GDB can now use Windows x64 unwinding data.
744 * The "set remotebaud" command has been replaced by "set serial baud".
745 Similarly, "show remotebaud" has been replaced by "show serial baud".
746 The "set remotebaud" and "show remotebaud" commands are still available
747 to provide backward compatibility with older versions of GDB.
749 *** Changes in GDB 7.6
751 * Target record has been renamed to record-full.
752 Record/replay is now enabled with the "record full" command.
753 This also affects settings that are associated with full record/replay
754 that have been moved from "set/show record" to "set/show record full":
756 set|show record full insn-number-max
757 set|show record full stop-at-limit
758 set|show record full memory-query
760 * A new record target "record-btrace" has been added. The new target
761 uses hardware support to record the control-flow of a process. It
762 does not support replaying the execution, but it implements the
763 below new commands for investigating the recorded execution log.
764 This new recording method can be enabled using:
768 The "record-btrace" target is only available on Intel Atom processors
769 and requires a Linux kernel 2.6.32 or later.
771 * Two new commands have been added for record/replay to give information
772 about the recorded execution without having to replay the execution.
773 The commands are only supported by "record btrace".
775 record instruction-history prints the execution history at
776 instruction granularity
778 record function-call-history prints the execution history at
781 * New native configurations
783 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
784 FreeBSD/powerpc powerpc*-*-freebsd
785 x86_64/Cygwin x86_64-*-cygwin*
786 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
790 ARM AArch64 aarch64*-*-elf
791 ARM AArch64 GNU/Linux aarch64*-*-linux
792 Lynx 178 PowerPC powerpc-*-lynx*178
793 x86_64/Cygwin x86_64-*-cygwin*
794 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
796 * If the configured location of system.gdbinit file (as given by the
797 --with-system-gdbinit option at configure time) is in the
798 data-directory (as specified by --with-gdb-datadir at configure
799 time) or in one of its subdirectories, then GDB will look for the
800 system-wide init file in the directory specified by the
801 --data-directory command-line option.
803 * New command line options:
805 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
806 other initialization files, unlike -nx which disables all of them.
808 * Removed command line options
810 -epoch This was used by the gdb mode in Epoch, an ancient fork of
813 * The 'ptype' and 'whatis' commands now accept an argument to control
816 * 'info proc' now works on some core files.
820 ** Vectors can be created with gdb.Type.vector.
822 ** Python's atexit.register now works in GDB.
824 ** Types can be pretty-printed via a Python API.
826 ** Python 3 is now supported (in addition to Python 2.4 or later)
828 ** New class gdb.Architecture exposes GDB's internal representation
829 of architecture in the Python API.
831 ** New method Frame.architecture returns the gdb.Architecture object
832 corresponding to the frame's architecture.
834 * New Python-based convenience functions:
836 ** $_memeq(buf1, buf2, length)
837 ** $_streq(str1, str2)
839 ** $_regex(str, regex)
841 * The 'cd' command now defaults to using '~' (the home directory) if not
844 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
845 default for GCC since November 2000.
847 * The command 'forward-search' can now be abbreviated as 'fo'.
849 * The command 'info tracepoints' can now display 'installed on target'
850 or 'not installed on target' for each non-pending location of tracepoint.
852 * New configure options
854 --enable-libmcheck/--disable-libmcheck
855 By default, development versions are built with -lmcheck on hosts
856 that support it, in order to help track memory corruption issues.
857 Release versions, on the other hand, are built without -lmcheck
858 by default. The --enable-libmcheck/--disable-libmcheck configure
859 options allow the user to override that default.
860 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
861 This configure option allows the user to build GDB with
862 libbabeltrace using which GDB can read Common Trace Format data.
864 * New commands (for set/show, see "New options" below)
867 Catch signals. This is similar to "handle", but allows commands and
868 conditions to be attached.
871 List the BFDs known to GDB.
873 python-interactive [command]
875 Start a Python interactive prompt, or evaluate the optional command
876 and print the result of expressions.
879 "py" is a new alias for "python".
881 enable type-printer [name]...
882 disable type-printer [name]...
883 Enable or disable type printers.
887 ** For the Renesas Super-H architecture, the "regs" command has been removed
888 (has been deprecated in GDB 7.5), and "info all-registers" should be used
893 set print type methods (on|off)
894 show print type methods
895 Control whether method declarations are displayed by "ptype".
896 The default is to show them.
898 set print type typedefs (on|off)
899 show print type typedefs
900 Control whether typedef definitions are displayed by "ptype".
901 The default is to show them.
903 set filename-display basename|relative|absolute
904 show filename-display
905 Control the way in which filenames is displayed.
906 The default is "relative", which preserves previous behavior.
908 set trace-buffer-size
909 show trace-buffer-size
910 Request target to change the size of trace buffer.
912 set remote trace-buffer-size-packet auto|on|off
913 show remote trace-buffer-size-packet
914 Control the use of the remote protocol `QTBuffer:size' packet.
918 Control display of debugging messages related to ARM AArch64.
921 set debug coff-pe-read
922 show debug coff-pe-read
923 Control display of debugging messages related to reading of COFF/PE
928 Control display of debugging messages related to Mach-O symbols
931 set debug notification
932 show debug notification
933 Control display of debugging info for async remote notification.
937 ** Command parameter changes are now notified using new async record
938 "=cmd-param-changed".
939 ** Trace frame changes caused by command "tfind" are now notified using
940 new async record "=traceframe-changed".
941 ** The creation, deletion and modification of trace state variables
942 are now notified using new async records "=tsv-created",
943 "=tsv-deleted" and "=tsv-modified".
944 ** The start and stop of process record are now notified using new
945 async record "=record-started" and "=record-stopped".
946 ** Memory changes are now notified using new async record
948 ** The data-disassemble command response will include a "fullname" field
949 containing the absolute file name when source has been requested.
950 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
951 command, to allow pattern filling of memory areas.
952 ** New commands "-catch-load"/"-catch-unload" added for intercepting
953 library load/unload events.
954 ** The response to breakpoint commands and breakpoint async records
955 includes an "installed" field containing a boolean state about each
956 non-pending tracepoint location is whether installed on target or not.
957 ** Output of the "-trace-status" command includes a "trace-file" field
958 containing the name of the trace file being examined. This field is
959 optional, and only present when examining a trace file.
960 ** The "fullname" field is now always present along with the "file" field,
961 even if the file cannot be found by GDB.
963 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
964 You must have the LZMA library available when configuring GDB for this
965 feature to be enabled. For more information, see:
966 http://fedoraproject.org/wiki/Features/MiniDebugInfo
971 Set the size of trace buffer. The remote stub reports support for this
972 packet to gdb's qSupported query.
975 Enable Branch Trace Store (BTS)-based branch tracing for the current
976 thread. The remote stub reports support for this packet to gdb's
980 Disable branch tracing for the current thread. The remote stub reports
981 support for this packet to gdb's qSupported query.
984 Read the traced branches for the current thread. The remote stub
985 reports support for this packet to gdb's qSupported query.
987 *** Changes in GDB 7.5
989 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
990 for more x32 ABI info.
992 * GDB now supports access to MIPS DSP registers on Linux targets.
994 * GDB now supports debugging microMIPS binaries.
996 * The "info os" command on GNU/Linux can now display information on
997 several new classes of objects managed by the operating system:
998 "info os procgroups" lists process groups
999 "info os files" lists file descriptors
1000 "info os sockets" lists internet-domain sockets
1001 "info os shm" lists shared-memory regions
1002 "info os semaphores" lists semaphores
1003 "info os msg" lists message queues
1004 "info os modules" lists loaded kernel modules
1006 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1007 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1008 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1009 options and inspect the probe arguments using the new $_probe_arg family
1010 of convenience variables. You can obtain more information about SystemTap
1011 in <http://sourceware.org/systemtap/>.
1013 * GDB now supports reversible debugging on ARM, it allows you to
1014 debug basic ARM and THUMB instructions, and provides
1015 record/replay support.
1017 * The option "symbol-reloading" has been deleted as it is no longer used.
1021 ** GDB commands implemented in Python can now be put in command class
1024 ** The "maint set python print-stack on|off" is now deleted.
1026 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1027 apply "flag enum"-style pretty-printing to any enum.
1029 ** gdb.lookup_symbol can now work when there is no current frame.
1031 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1032 the source at which the symbol was defined.
1034 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1035 method 'value'. The former indicates whether the symbol needs a
1036 frame in order to compute its value, and the latter computes the
1039 ** A new method 'referenced_value' on gdb.Value objects which can
1040 dereference pointer as well as C++ reference values.
1042 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1043 which return the global and static blocks (as gdb.Block objects),
1044 of the underlying symbol table, respectively.
1046 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1047 object associated with a PC value.
1049 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1050 of the address range occupied by code for the current source line.
1052 * Go language support.
1053 GDB now supports debugging programs written in the Go programming
1056 * GDBserver now supports stdio connections.
1057 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1059 * The binary "gdbtui" can no longer be built or installed.
1060 Use "gdb -tui" instead.
1062 * GDB will now print "flag" enums specially. A flag enum is one where
1063 all the enumerator values have no bits in common when pairwise
1064 "and"ed. When printing a value whose type is a flag enum, GDB will
1065 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1066 (gdb) print (enum E) 3
1069 * The filename part of a linespec will now match trailing components
1070 of a source file name. For example, "break gcc/expr.c:1000" will
1071 now set a breakpoint in build/gcc/expr.c, but not
1072 build/libcpp/expr.c.
1074 * The "info proc" and "generate-core-file" commands will now also
1075 work on remote targets connected to GDBserver on Linux.
1077 * The command "info catch" has been removed. It has been disabled
1078 since December 2007.
1080 * The "catch exception" and "catch assert" commands now accept
1081 a condition at the end of the command, much like the "break"
1082 command does. For instance:
1084 (gdb) catch exception Constraint_Error if Barrier = True
1086 Previously, it was possible to add a condition to such catchpoints,
1087 but it had to be done as a second step, after the catchpoint had been
1088 created, using the "condition" command.
1090 * The "info static-tracepoint-marker" command will now also work on
1091 native Linux targets with in-process agent.
1093 * GDB can now set breakpoints on inlined functions.
1095 * The .gdb_index section has been updated to include symbols for
1096 inlined functions. GDB will ignore older .gdb_index sections by
1097 default, which could cause symbol files to be loaded more slowly
1098 until their .gdb_index sections can be recreated. The new command
1099 "set use-deprecated-index-sections on" will cause GDB to use any older
1100 .gdb_index sections it finds. This will restore performance, but the
1101 ability to set breakpoints on inlined functions will be lost in symbol
1102 files with older .gdb_index sections.
1104 The .gdb_index section has also been updated to record more information
1105 about each symbol. This speeds up the "info variables", "info functions"
1106 and "info types" commands when used with programs having the .gdb_index
1107 section, as well as speeding up debugging with shared libraries using
1108 the .gdb_index section.
1110 * Ada support for GDB/MI Variable Objects has been added.
1112 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1117 ** New command -info-os is the MI equivalent of "info os".
1119 ** Output logs ("set logging" and related) now include MI output.
1123 ** "set use-deprecated-index-sections on|off"
1124 "show use-deprecated-index-sections on|off"
1125 Controls the use of deprecated .gdb_index sections.
1127 ** "catch load" and "catch unload" can be used to stop when a shared
1128 library is loaded or unloaded, respectively.
1130 ** "enable count" can be used to auto-disable a breakpoint after
1133 ** "info vtbl" can be used to show the virtual method tables for
1134 C++ and Java objects.
1136 ** "explore" and its sub commands "explore value" and "explore type"
1137 can be used to recursively explore values and types of
1138 expressions. These commands are available only if GDB is
1139 configured with '--with-python'.
1141 ** "info auto-load" shows status of all kinds of auto-loaded files,
1142 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1143 sequences of commands files, "info auto-load python-scripts"
1144 shows status of auto-loading Python script files,
1145 "info auto-load local-gdbinit" shows status of loading init file
1146 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1147 status of inferior specific thread debugging shared library loading.
1149 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1150 and "show auto-load-scripts" commands have been deprecated, use their
1151 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1152 and "show auto-load python-scripts" counterparts instead.
1154 ** "dprintf location,format,args..." creates a dynamic printf, which
1155 is basically a breakpoint that does a printf and immediately
1156 resumes your program's execution, so it is like a printf that you
1157 can insert dynamically at runtime instead of at compiletime.
1159 ** "set print symbol"
1161 Controls whether GDB attempts to display the symbol, if any,
1162 corresponding to addresses it prints. This defaults to "on", but
1163 you can set it to "off" to restore GDB's previous behavior.
1165 * Deprecated commands
1167 ** For the Renesas Super-H architecture, the "regs" command has been
1168 deprecated, and "info all-registers" should be used instead.
1172 Renesas RL78 rl78-*-elf
1173 HP OpenVMS ia64 ia64-hp-openvms*
1175 * GDBserver supports evaluation of breakpoint conditions. When
1176 support is advertised by GDBserver, GDB may be told to send the
1177 breakpoint conditions in bytecode form to GDBserver. GDBserver
1178 will only report the breakpoint trigger to GDB when its condition
1183 set mips compression
1184 show mips compression
1185 Select the compressed ISA encoding used in functions that have no symbol
1186 information available. The encoding can be set to either of:
1189 and is updated automatically from ELF file flags if available.
1191 set breakpoint condition-evaluation
1192 show breakpoint condition-evaluation
1193 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1194 GDBserver ("target"). Default option "auto" chooses the most efficient
1196 This option can improve debugger efficiency depending on the speed of the
1200 Disable auto-loading globally.
1203 Show auto-loading setting of all kinds of auto-loaded files.
1205 set auto-load gdb-scripts on|off
1206 show auto-load gdb-scripts
1207 Control auto-loading of GDB canned sequences of commands files.
1209 set auto-load python-scripts on|off
1210 show auto-load python-scripts
1211 Control auto-loading of Python script files.
1213 set auto-load local-gdbinit on|off
1214 show auto-load local-gdbinit
1215 Control loading of init file (.gdbinit) from current directory.
1217 set auto-load libthread-db on|off
1218 show auto-load libthread-db
1219 Control auto-loading of inferior specific thread debugging shared library.
1221 set auto-load scripts-directory <dir1>[:<dir2>...]
1222 show auto-load scripts-directory
1223 Set a list of directories from which to load auto-loaded scripts.
1224 Automatically loaded Python scripts and GDB scripts are located in one
1225 of the directories listed by this option.
1226 The delimiter (':' above) may differ according to the host platform.
1228 set auto-load safe-path <dir1>[:<dir2>...]
1229 show auto-load safe-path
1230 Set a list of directories from which it is safe to auto-load files.
1231 The delimiter (':' above) may differ according to the host platform.
1233 set debug auto-load on|off
1234 show debug auto-load
1235 Control display of debugging info for auto-loading the files above.
1237 set dprintf-style gdb|call|agent
1239 Control the way in which a dynamic printf is performed; "gdb"
1240 requests a GDB printf command, while "call" causes dprintf to call a
1241 function in the inferior. "agent" requests that the target agent
1242 (such as GDBserver) do the printing.
1244 set dprintf-function <expr>
1245 show dprintf-function
1246 set dprintf-channel <expr>
1247 show dprintf-channel
1248 Set the function and optional first argument to the call when using
1249 the "call" style of dynamic printf.
1251 set disconnected-dprintf on|off
1252 show disconnected-dprintf
1253 Control whether agent-style dynamic printfs continue to be in effect
1254 after GDB disconnects.
1256 * New configure options
1258 --with-auto-load-dir
1259 Configure default value for the 'set auto-load scripts-directory'
1260 setting above. It defaults to '$debugdir:$datadir/auto-load',
1261 $debugdir representing global debugging info directories (available
1262 via 'show debug-file-directory') and $datadir representing GDB's data
1263 directory (available via 'show data-directory').
1265 --with-auto-load-safe-path
1266 Configure default value for the 'set auto-load safe-path' setting
1267 above. It defaults to the --with-auto-load-dir setting.
1269 --without-auto-load-safe-path
1270 Set 'set auto-load safe-path' to '/', effectively disabling this
1273 * New remote packets
1275 z0/z1 conditional breakpoints extension
1277 The z0/z1 breakpoint insertion packets have been extended to carry
1278 a list of conditional expressions over to the remote stub depending on the
1279 condition evaluation mode. The use of this extension can be controlled
1280 via the "set remote conditional-breakpoints-packet" command.
1284 Specify the signals which the remote stub may pass to the debugged
1285 program without GDB involvement.
1287 * New command line options
1289 --init-command=FILE, -ix Like --command, -x but execute it
1290 before loading inferior.
1291 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1292 execute it before loading inferior.
1294 *** Changes in GDB 7.4
1296 * GDB now handles ambiguous linespecs more consistently; the existing
1297 FILE:LINE support has been expanded to other types of linespecs. A
1298 breakpoint will now be set on all matching locations in all
1299 inferiors, and locations will be added or removed according to
1302 * GDB now allows you to skip uninteresting functions and files when
1303 stepping with the "skip function" and "skip file" commands.
1305 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1306 and "show remote hardware-watchpoint-length-limit". These allows to
1307 set or show the maximum length limit (in bytes) of a remote
1308 target hardware watchpoint.
1310 This allows e.g. to use "unlimited" hardware watchpoints with the
1311 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1312 watchpoints are slower than real hardware watchpoints but are
1313 significantly faster than gdb software watchpoints.
1317 ** The register_pretty_printer function in module gdb.printing now takes
1318 an optional `replace' argument. If True, the new printer replaces any
1321 ** The "maint set python print-stack on|off" command has been
1322 deprecated and will be deleted in GDB 7.5.
1323 A new command: "set python print-stack none|full|message" has
1324 replaced it. Additionally, the default for "print-stack" is
1325 now "message", which just prints the error message without
1328 ** A prompt substitution hook (prompt_hook) is now available to the
1331 ** A new Python module, gdb.prompt has been added to the GDB Python
1332 modules library. This module provides functionality for
1333 escape sequences in prompts (used by set/show
1334 extended-prompt). These escape sequences are replaced by their
1335 corresponding value.
1337 ** Python commands and convenience-functions located in
1338 'data-directory'/python/gdb/command and
1339 'data-directory'/python/gdb/function are now automatically loaded
1342 ** Blocks now provide four new attributes. global_block and
1343 static_block will return the global and static blocks
1344 respectively. is_static and is_global are boolean attributes
1345 that indicate if the block is one of those two types.
1347 ** Symbols now provide the "type" attribute, the type of the symbol.
1349 ** The "gdb.breakpoint" function has been deprecated in favor of
1352 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1353 of a function. This class is based on the "finish" command
1354 available in the CLI.
1356 ** Type objects for struct and union types now allow access to
1357 the fields using standard Python dictionary (mapping) methods.
1358 For example, "some_type['myfield']" now works, as does
1359 "some_type.items()".
1361 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1364 ** A new function, "deep_items" has been added to the gdb.types
1365 module in the GDB Python modules library. This function returns
1366 an iterator over the fields of a struct or union type. Unlike
1367 the standard Python "iteritems" method, it will recursively traverse
1368 any anonymous fields.
1372 ** "*stopped" events can report several new "reason"s, such as
1375 ** Breakpoint changes are now notified using new async records, like
1376 "=breakpoint-modified".
1378 ** New command -ada-task-info.
1380 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1381 $sdir specifies the default system locations of shared libraries.
1382 $pdir specifies the directory where the libpthread used by the application
1385 GDB no longer looks in $sdir and $pdir after it has searched the directories
1386 mentioned in libthread-db-search-path. If you want to search those
1387 directories, they must be specified in libthread-db-search-path.
1388 The default value of libthread-db-search-path on GNU/Linux and Solaris
1389 systems is now "$sdir:$pdir".
1391 $pdir is not supported by gdbserver, it is currently ignored.
1392 $sdir is supported by gdbserver.
1394 * New configure option --with-iconv-bin.
1395 When using the internationalization support like the one in the GNU C
1396 library, GDB will invoke the "iconv" program to get a list of supported
1397 character sets. If this program lives in a non-standard location, one can
1398 use this option to specify where to find it.
1400 * When natively debugging programs on PowerPC BookE processors running
1401 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1402 watchpoints, which specify a mask in addition to an address to watch.
1403 The mask specifies that some bits of an address (the bits which are
1404 reset in the mask) should be ignored when matching the address accessed
1405 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1406 section in the user manual for more details.
1408 * The new option --once causes GDBserver to stop listening for connections once
1409 the first connection is made. The listening port used by GDBserver will
1410 become available after that.
1412 * New commands "info macros" and "alias" have been added.
1414 * New function parameters suffix @entry specifies value of function parameter
1415 at the time the function got called. Entry values are available only since
1421 "!" is now an alias of the "shell" command.
1422 Note that no space is needed between "!" and SHELL COMMAND.
1426 watch EXPRESSION mask MASK_VALUE
1427 The watch command now supports the mask argument which allows creation
1428 of masked watchpoints, if the current architecture supports this feature.
1430 info auto-load-scripts [REGEXP]
1431 This command was formerly named "maintenance print section-scripts".
1432 It is now generally useful and is no longer a maintenance-only command.
1434 info macro [-all] [--] MACRO
1435 The info macro command has new options `-all' and `--'. The first for
1436 printing all definitions of a macro. The second for explicitly specifying
1437 the end of arguments and the beginning of the macro name in case the macro
1438 name starts with a hyphen.
1440 collect[/s] EXPRESSIONS
1441 The tracepoint collect command now takes an optional modifier "/s"
1442 that directs it to dereference pointer-to-character types and
1443 collect the bytes of memory up to a zero byte. The behavior is
1444 similar to what you see when you use the regular print command on a
1445 string. An optional integer following the "/s" sets a bound on the
1446 number of bytes that will be collected.
1449 The trace start command now interprets any supplied arguments as a
1450 note to be recorded with the trace run, with an effect similar to
1451 setting the variable trace-notes.
1454 The trace stop command now interprets any arguments as a note to be
1455 mentioned along with the tstatus report that the trace was stopped
1456 with a command. The effect is similar to setting the variable
1459 * Tracepoints can now be enabled and disabled at any time after a trace
1460 experiment has been started using the standard "enable" and "disable"
1461 commands. It is now possible to start a trace experiment with no enabled
1462 tracepoints; GDB will display a warning, but will allow the experiment to
1463 begin, assuming that tracepoints will be enabled as needed while the trace
1466 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1467 locations with 4-byte instructions, when they were previously
1468 limited to locations with instructions of 5 bytes or longer.
1472 set debug dwarf2-read
1473 show debug dwarf2-read
1474 Turns on or off display of debugging messages related to reading
1475 DWARF debug info. The default is off.
1477 set debug symtab-create
1478 show debug symtab-create
1479 Turns on or off display of debugging messages related to symbol table
1480 creation. The default is off.
1483 show extended-prompt
1484 Set the GDB prompt, and allow escape sequences to be inserted to
1485 display miscellaneous information (see 'help set extended-prompt'
1486 for the list of sequences). This prompt (and any information
1487 accessed through the escape sequences) is updated every time the
1488 prompt is displayed.
1490 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1491 show print entry-values
1492 Set printing of frame argument values at function entry. In some cases
1493 GDB can determine the value of function argument which was passed by the
1494 function caller, even if the value was modified inside the called function.
1496 set debug entry-values
1497 show debug entry-values
1498 Control display of debugging info for determining frame argument values at
1499 function entry and virtual tail call frames.
1501 set basenames-may-differ
1502 show basenames-may-differ
1503 Set whether a source file may have multiple base names.
1504 (A "base name" is the name of a file with the directory part removed.
1505 Example: The base name of "/home/user/hello.c" is "hello.c".)
1506 If set, GDB will canonicalize file names (e.g., expand symlinks)
1507 before comparing them. Canonicalization is an expensive operation,
1508 but it allows the same file be known by more than one base name.
1509 If not set (the default), all source files are assumed to have just
1510 one base name, and gdb will do file name comparisons more efficiently.
1516 Set a user name and notes for the current and any future trace runs.
1517 This is useful for long-running and/or disconnected traces, to
1518 inform others (or yourself) as to who is running the trace, supply
1519 contact information, or otherwise explain what is going on.
1521 set trace-stop-notes
1522 show trace-stop-notes
1523 Set a note attached to the trace run, that is displayed when the
1524 trace has been stopped by a tstop command. This is useful for
1525 instance as an explanation, if you are stopping a trace run that was
1526 started by someone else.
1528 * New remote packets
1532 Dynamically enable a tracepoint in a started trace experiment.
1536 Dynamically disable a tracepoint in a started trace experiment.
1540 Set the user and notes of the trace run.
1544 Query the current status of a tracepoint.
1548 Query the minimum length of instruction at which a fast tracepoint may
1551 * Dcache size (number of lines) and line-size are now runtime-configurable
1552 via "set dcache line" and "set dcache line-size" commands.
1556 Texas Instruments TMS320C6x tic6x-*-*
1560 Renesas RL78 rl78-*-elf
1562 *** Changes in GDB 7.3.1
1564 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1566 *** Changes in GDB 7.3
1568 * GDB has a new command: "thread find [REGEXP]".
1569 It finds the thread id whose name, target id, or thread extra info
1570 matches the given regular expression.
1572 * The "catch syscall" command now works on mips*-linux* targets.
1574 * The -data-disassemble MI command now supports modes 2 and 3 for
1575 dumping the instruction opcodes.
1577 * New command line options
1579 -data-directory DIR Specify DIR as the "data-directory".
1580 This is mostly for testing purposes.
1582 * The "maint set python auto-load on|off" command has been renamed to
1583 "set auto-load-scripts on|off".
1585 * GDB has a new command: "set directories".
1586 It is like the "dir" command except that it replaces the
1587 source path list instead of augmenting it.
1589 * GDB now understands thread names.
1591 On GNU/Linux, "info threads" will display the thread name as set by
1592 prctl or pthread_setname_np.
1594 There is also a new command, "thread name", which can be used to
1595 assign a name internally for GDB to display.
1598 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1599 has been integrated into GDB.
1603 ** The function gdb.Write now accepts an optional keyword 'stream'.
1604 This keyword, when provided, will direct the output to either
1605 stdout, stderr, or GDB's logging output.
1607 ** Parameters can now be be sub-classed in Python, and in particular
1608 you may implement the get_set_doc and get_show_doc functions.
1609 This improves how Parameter set/show documentation is processed
1610 and allows for more dynamic content.
1612 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1613 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1614 have an is_valid method.
1616 ** Breakpoints can now be sub-classed in Python, and in particular
1617 you may implement a 'stop' function that is executed each time
1618 the inferior reaches that breakpoint.
1620 ** New function gdb.lookup_global_symbol looks up a global symbol.
1622 ** GDB values in Python are now callable if the value represents a
1623 function. For example, if 'some_value' represents a function that
1624 takes two integer parameters and returns a value, you can call
1625 that function like so:
1627 result = some_value (10,20)
1629 ** Module gdb.types has been added.
1630 It contains a collection of utilities for working with gdb.Types objects:
1631 get_basic_type, has_field, make_enum_dict.
1633 ** Module gdb.printing has been added.
1634 It contains utilities for writing and registering pretty-printers.
1635 New classes: PrettyPrinter, SubPrettyPrinter,
1636 RegexpCollectionPrettyPrinter.
1637 New function: register_pretty_printer.
1639 ** New commands "info pretty-printers", "enable pretty-printer" and
1640 "disable pretty-printer" have been added.
1642 ** gdb.parameter("directories") is now available.
1644 ** New function gdb.newest_frame returns the newest frame in the
1647 ** The gdb.InferiorThread class has a new "name" attribute. This
1648 holds the thread's name.
1650 ** Python Support for Inferior events.
1651 Python scripts can add observers to be notified of events
1652 occurring in the process being debugged.
1653 The following events are currently supported:
1654 - gdb.events.cont Continue event.
1655 - gdb.events.exited Inferior exited event.
1656 - gdb.events.stop Signal received, and Breakpoint hit events.
1660 ** GDB now puts template parameters in scope when debugging in an
1661 instantiation. For example, if you have:
1663 template<int X> int func (void) { return X; }
1665 then if you step into func<5>, "print X" will show "5". This
1666 feature requires proper debuginfo support from the compiler; it
1667 was added to GCC 4.5.
1669 ** The motion commands "next", "finish", "until", and "advance" now
1670 work better when exceptions are thrown. In particular, GDB will
1671 no longer lose control of the inferior; instead, the GDB will
1672 stop the inferior at the point at which the exception is caught.
1673 This functionality requires a change in the exception handling
1674 code that was introduced in GCC 4.5.
1676 * GDB now follows GCC's rules on accessing volatile objects when
1677 reading or writing target state during expression evaluation.
1678 One notable difference to prior behavior is that "print x = 0"
1679 no longer generates a read of x; the value of the assignment is
1680 now always taken directly from the value being assigned.
1682 * GDB now has some support for using labels in the program's source in
1683 linespecs. For instance, you can use "advance label" to continue
1684 execution to a label.
1686 * GDB now has support for reading and writing a new .gdb_index
1687 section. This section holds a fast index of DWARF debugging
1688 information and can be used to greatly speed up GDB startup and
1689 operation. See the documentation for `save gdb-index' for details.
1691 * The "watch" command now accepts an optional "-location" argument.
1692 When used, this causes GDB to watch the memory referred to by the
1693 expression. Such a watchpoint is never deleted due to it going out
1696 * GDB now supports thread debugging of core dumps on GNU/Linux.
1698 GDB now activates thread debugging using the libthread_db library
1699 when debugging GNU/Linux core dumps, similarly to when debugging
1700 live processes. As a result, when debugging a core dump file, GDB
1701 is now able to display pthread_t ids of threads. For example, "info
1702 threads" shows the same output as when debugging the process when it
1703 was live. In earlier releases, you'd see something like this:
1706 * 1 LWP 6780 main () at main.c:10
1708 While now you see this:
1711 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1713 It is also now possible to inspect TLS variables when debugging core
1716 When debugging a core dump generated on a machine other than the one
1717 used to run GDB, you may need to point GDB at the correct
1718 libthread_db library with the "set libthread-db-search-path"
1719 command. See the user manual for more details on this command.
1721 * When natively debugging programs on PowerPC BookE processors running
1722 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1723 which stop execution of the inferior whenever it executes an instruction
1724 at any address within the specified range. See the "PowerPC Embedded"
1725 section in the user manual for more details.
1727 * New features in the GDB remote stub, GDBserver
1729 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1730 and i686 LynxOS (version 5.x).
1732 ** GDBserver is now supported on Blackfin Linux.
1734 * New native configurations
1736 ia64 HP-UX ia64-*-hpux*
1740 Analog Devices, Inc. Blackfin Processor bfin-*
1742 * Ada task switching is now supported on sparc-elf targets when
1743 debugging a program using the Ravenscar Profile. For more information,
1744 see the "Tasking Support when using the Ravenscar Profile" section
1745 in the GDB user manual.
1747 * Guile support was removed.
1749 * New features in the GNU simulator
1751 ** The --map-info flag lists all known core mappings.
1753 ** CFI flashes may be simulated via the "cfi" device.
1755 *** Changes in GDB 7.2
1757 * Shared library support for remote targets by default
1759 When GDB is configured for a generic, non-OS specific target, like
1760 for example, --target=arm-eabi or one of the many *-*-elf targets,
1761 GDB now queries remote stubs for loaded shared libraries using the
1762 `qXfer:libraries:read' packet. Previously, shared library support
1763 was always disabled for such configurations.
1767 ** Argument Dependent Lookup (ADL)
1769 In C++ ADL lookup directs function search to the namespaces of its
1770 arguments even if the namespace has not been imported.
1780 Here the compiler will search for `foo' in the namespace of 'b'
1781 and find A::foo. GDB now supports this. This construct is commonly
1782 used in the Standard Template Library for operators.
1784 ** Improved User Defined Operator Support
1786 In addition to member operators, GDB now supports lookup of operators
1787 defined in a namespace and imported with a `using' directive, operators
1788 defined in the global scope, operators imported implicitly from an
1789 anonymous namespace, and the ADL operators mentioned in the previous
1791 GDB now also supports proper overload resolution for all the previously
1792 mentioned flavors of operators.
1794 ** static const class members
1796 Printing of static const class members that are initialized in the
1797 class definition has been fixed.
1799 * Windows Thread Information Block access.
1801 On Windows targets, GDB now supports displaying the Windows Thread
1802 Information Block (TIB) structure. This structure is visible either
1803 by using the new command `info w32 thread-information-block' or, by
1804 dereferencing the new convenience variable named `$_tlb', a
1805 thread-specific pointer to the TIB. This feature is also supported
1806 when remote debugging using GDBserver.
1808 * Static tracepoints
1810 Static tracepoints are calls in the user program into a tracing
1811 library. One such library is a port of the LTTng kernel tracer to
1812 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1813 When debugging with GDBserver, GDB now supports combining the GDB
1814 tracepoint machinery with such libraries. For example: the user can
1815 use GDB to probe a static tracepoint marker (a call from the user
1816 program into the tracing library) with the new "strace" command (see
1817 "New commands" below). This creates a "static tracepoint" in the
1818 breakpoint list, that can be manipulated with the same feature set
1819 as fast and regular tracepoints. E.g., collect registers, local and
1820 global variables, collect trace state variables, and define
1821 tracepoint conditions. In addition, the user can collect extra
1822 static tracepoint marker specific data, by collecting the new
1823 $_sdata internal variable. When analyzing the trace buffer, you can
1824 inspect $_sdata like any other variable available to GDB. For more
1825 information, see the "Tracepoints" chapter in GDB user manual. New
1826 remote packets have been defined to support static tracepoints, see
1827 the "New remote packets" section below.
1829 * Better reconstruction of tracepoints after disconnected tracing
1831 GDB will attempt to download the original source form of tracepoint
1832 definitions when starting a trace run, and then will upload these
1833 upon reconnection to the target, resulting in a more accurate
1834 reconstruction of the tracepoints that are in use on the target.
1838 You can now exercise direct control over the ways that GDB can
1839 affect your program. For instance, you can disallow the setting of
1840 breakpoints, so that the program can run continuously (assuming
1841 non-stop mode). In addition, the "observer" variable is available
1842 to switch all of the different controls; in observer mode, GDB
1843 cannot affect the target's behavior at all, which is useful for
1844 tasks like diagnosing live systems in the field.
1846 * The new convenience variable $_thread holds the number of the
1849 * New remote packets
1853 Return the address of the Windows Thread Information Block of a given thread.
1857 In response to several of the tracepoint packets, the target may now
1858 also respond with a number of intermediate `qRelocInsn' request
1859 packets before the final result packet, to have GDB handle
1860 relocating an instruction to execute at a different address. This
1861 is particularly useful for stubs that support fast tracepoints. GDB
1862 reports support for this feature in the qSupported packet.
1866 List static tracepoint markers in the target program.
1870 List static tracepoint markers at a given address in the target
1873 qXfer:statictrace:read
1875 Read the static trace data collected (by a `collect $_sdata'
1876 tracepoint action). The remote stub reports support for this packet
1877 to gdb's qSupported query.
1881 Send the current settings of GDB's permission flags.
1885 Send part of the source (textual) form of a tracepoint definition,
1886 which includes location, conditional, and action list.
1888 * The source command now accepts a -s option to force searching for the
1889 script in the source search path even if the script name specifies
1892 * New features in the GDB remote stub, GDBserver
1894 - GDBserver now support tracepoints (including fast tracepoints, and
1895 static tracepoints). The feature is currently supported by the
1896 i386-linux and amd64-linux builds. See the "Tracepoints support
1897 in gdbserver" section in the manual for more information.
1899 GDBserver JIT compiles the tracepoint's conditional agent
1900 expression bytecode into native code whenever possible for low
1901 overhead dynamic tracepoints conditionals. For such tracepoints,
1902 an expression that examines program state is evaluated when the
1903 tracepoint is reached, in order to determine whether to capture
1904 trace data. If the condition is simple and false, processing the
1905 tracepoint finishes very quickly and no data is gathered.
1907 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1908 for static tracepoints support.
1910 - GDBserver now supports x86_64 Windows 64-bit debugging.
1912 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1913 it understands register description.
1915 * The --batch flag now disables pagination and queries.
1917 * X86 general purpose registers
1919 GDB now supports reading/writing byte, word and double-word x86
1920 general purpose registers directly. This means you can use, say,
1921 $ah or $ax to refer, respectively, to the byte register AH and
1922 16-bit word register AX that are actually portions of the 32-bit
1923 register EAX or 64-bit register RAX.
1925 * The `commands' command now accepts a range of breakpoints to modify.
1926 A plain `commands' following a command that creates multiple
1927 breakpoints affects all the breakpoints set by that command. This
1928 applies to breakpoints set by `rbreak', and also applies when a
1929 single `break' command creates multiple breakpoints (e.g.,
1930 breakpoints on overloaded c++ functions).
1932 * The `rbreak' command now accepts a filename specification as part of
1933 its argument, limiting the functions selected by the regex to those
1934 in the specified file.
1936 * Support for remote debugging Windows and SymbianOS shared libraries
1937 from Unix hosts has been improved. Non Windows GDB builds now can
1938 understand target reported file names that follow MS-DOS based file
1939 system semantics, such as file names that include drive letters and
1940 use the backslash character as directory separator. This makes it
1941 possible to transparently use the "set sysroot" and "set
1942 solib-search-path" on Unix hosts to point as host copies of the
1943 target's shared libraries. See the new command "set
1944 target-file-system-kind" described below, and the "Commands to
1945 specify files" section in the user manual for more information.
1949 eval template, expressions...
1950 Convert the values of one or more expressions under the control
1951 of the string template to a command line, and call it.
1953 set target-file-system-kind unix|dos-based|auto
1954 show target-file-system-kind
1955 Set or show the assumed file system kind for target reported file
1958 save breakpoints <filename>
1959 Save all current breakpoint definitions to a file suitable for use
1960 in a later debugging session. To read the saved breakpoint
1961 definitions, use the `source' command.
1963 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1966 info static-tracepoint-markers
1967 Display information about static tracepoint markers in the target.
1969 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1970 Define a static tracepoint by probing a marker at the given
1971 function, line, address, or marker ID.
1975 Enable and disable observer mode.
1977 set may-write-registers on|off
1978 set may-write-memory on|off
1979 set may-insert-breakpoints on|off
1980 set may-insert-tracepoints on|off
1981 set may-insert-fast-tracepoints on|off
1982 set may-interrupt on|off
1983 Set individual permissions for GDB effects on the target. Note that
1984 some of these settings can have undesirable or surprising
1985 consequences, particularly when changed in the middle of a session.
1986 For instance, disabling the writing of memory can prevent
1987 breakpoints from being inserted, cause single-stepping to fail, or
1988 even crash your program, if you disable after breakpoints have been
1989 inserted. However, GDB should not crash.
1991 set record memory-query on|off
1992 show record memory-query
1993 Control whether to stop the inferior if memory changes caused
1994 by an instruction cannot be recorded.
1999 The disassemble command now supports "start,+length" form of two arguments.
2003 ** GDB now provides a new directory location, called the python directory,
2004 where Python scripts written for GDB can be installed. The location
2005 of that directory is <data-directory>/python, where <data-directory>
2006 is the GDB data directory. For more details, see section `Scripting
2007 GDB using Python' in the manual.
2009 ** The GDB Python API now has access to breakpoints, symbols, symbol
2010 tables, program spaces, inferiors, threads and frame's code blocks.
2011 Additionally, GDB Parameters can now be created from the API, and
2012 manipulated via set/show in the CLI.
2014 ** New functions gdb.target_charset, gdb.target_wide_charset,
2015 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2017 ** New exception gdb.GdbError.
2019 ** Pretty-printers are now also looked up in the current program space.
2021 ** Pretty-printers can now be individually enabled and disabled.
2023 ** GDB now looks for names of Python scripts to auto-load in a
2024 special section named `.debug_gdb_scripts', in addition to looking
2025 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2027 * Tracepoint actions were unified with breakpoint commands. In particular,
2028 there are no longer differences in "info break" output for breakpoints and
2029 tracepoints and the "commands" command can be used for both tracepoints and
2030 regular breakpoints.
2034 ARM Symbian arm*-*-symbianelf*
2036 * D language support.
2037 GDB now supports debugging programs written in the D programming
2040 * GDB now supports the extended ptrace interface for PowerPC which is
2041 available since Linux kernel version 2.6.34. This automatically enables
2042 any hardware breakpoints and additional hardware watchpoints available in
2043 the processor. The old ptrace interface exposes just one hardware
2044 watchpoint and no hardware breakpoints.
2046 * GDB is now able to use the Data Value Compare (DVC) register available on
2047 embedded PowerPC processors to implement in hardware simple watchpoint
2048 conditions of the form:
2050 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2052 This works in native GDB running on Linux kernels with the extended ptrace
2053 interface mentioned above.
2055 *** Changes in GDB 7.1
2059 ** Namespace Support
2061 GDB now supports importing of namespaces in C++. This enables the
2062 user to inspect variables from imported namespaces. Support for
2063 namepace aliasing has also been added. So, if a namespace is
2064 aliased in the current scope (e.g. namepace C=A; ) the user can
2065 print variables using the alias (e.g. (gdb) print C::x).
2069 All known bugs relating to the printing of virtual base class were
2070 fixed. It is now possible to call overloaded static methods using a
2075 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2076 and reinterpret_cast<> are now handled by the C++ expression parser.
2080 Xilinx MicroBlaze microblaze-*-*
2085 Xilinx MicroBlaze microblaze
2088 * Multi-program debugging.
2090 GDB now has support for multi-program (a.k.a. multi-executable or
2091 multi-exec) debugging. This allows for debugging multiple inferiors
2092 simultaneously each running a different program under the same GDB
2093 session. See "Debugging Multiple Inferiors and Programs" in the
2094 manual for more information. This implied some user visible changes
2095 in the multi-inferior support. For example, "info inferiors" now
2096 lists inferiors that are not running yet or that have exited
2097 already. See also "New commands" and "New options" below.
2099 * New tracing features
2101 GDB's tracepoint facility now includes several new features:
2103 ** Trace state variables
2105 GDB tracepoints now include support for trace state variables, which
2106 are variables managed by the target agent during a tracing
2107 experiment. They are useful for tracepoints that trigger each
2108 other, so for instance one tracepoint can count hits in a variable,
2109 and then a second tracepoint has a condition that is true when the
2110 count reaches a particular value. Trace state variables share the
2111 $-syntax of GDB convenience variables, and can appear in both
2112 tracepoint actions and condition expressions. Use the "tvariable"
2113 command to create, and "info tvariables" to view; see "Trace State
2114 Variables" in the manual for more detail.
2118 GDB now includes an option for defining fast tracepoints, which
2119 targets may implement more efficiently, such as by installing a jump
2120 into the target agent rather than a trap instruction. The resulting
2121 speedup can be by two orders of magnitude or more, although the
2122 tradeoff is that some program locations on some target architectures
2123 might not allow fast tracepoint installation, for instance if the
2124 instruction to be replaced is shorter than the jump. To request a
2125 fast tracepoint, use the "ftrace" command, with syntax identical to
2126 the regular trace command.
2128 ** Disconnected tracing
2130 It is now possible to detach GDB from the target while it is running
2131 a trace experiment, then reconnect later to see how the experiment
2132 is going. In addition, a new variable disconnected-tracing lets you
2133 tell the target agent whether to continue running a trace if the
2134 connection is lost unexpectedly.
2138 GDB now has the ability to save the trace buffer into a file, and
2139 then use that file as a target, similarly to you can do with
2140 corefiles. You can select trace frames, print data that was
2141 collected in them, and use tstatus to display the state of the
2142 tracing run at the moment that it was saved. To create a trace
2143 file, use "tsave <filename>", and to use it, do "target tfile
2146 ** Circular trace buffer
2148 You can ask the target agent to handle the trace buffer as a
2149 circular buffer, discarding the oldest trace frames to make room for
2150 newer ones, by setting circular-trace-buffer to on. This feature may
2151 not be available for all target agents.
2156 The disassemble command, when invoked with two arguments, now requires
2157 the arguments to be comma-separated.
2160 The info variables command now displays variable definitions. Files
2161 which only declare a variable are not shown.
2164 The source command is now capable of sourcing Python scripts.
2165 This feature is dependent on the debugger being build with Python
2168 Related to this enhancement is also the introduction of a new command
2169 "set script-extension" (see below).
2171 * New commands (for set/show, see "New options" below)
2173 record save [<FILENAME>]
2174 Save a file (in core file format) containing the process record
2175 execution log for replay debugging at a later time.
2177 record restore <FILENAME>
2178 Restore the process record execution log that was saved at an
2179 earlier time, for replay debugging.
2181 add-inferior [-copies <N>] [-exec <FILENAME>]
2184 clone-inferior [-copies <N>] [ID]
2185 Make a new inferior ready to execute the same program another
2186 inferior has loaded.
2191 maint info program-spaces
2192 List the program spaces loaded into GDB.
2194 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2195 show remote interrupt-sequence
2196 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2197 as the sequence to the remote target in order to interrupt the execution.
2198 Ctrl-C is a default. Some system prefers BREAK which is high level of
2199 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2200 Magic SysRq g. It is BREAK signal and character 'g'.
2202 set remote interrupt-on-connect [on | off]
2203 show remote interrupt-on-connect
2204 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2205 remote target when gdb connects to it. This is needed when you debug
2208 set remotebreak [on | off]
2210 Deprecated. Use "set/show remote interrupt-sequence" instead.
2212 tvariable $NAME [ = EXP ]
2213 Create or modify a trace state variable.
2216 List trace state variables and their values.
2218 delete tvariable $NAME ...
2219 Delete one or more trace state variables.
2222 Evaluate the given expressions without collecting anything into the
2223 trace buffer. (Valid in tracepoint actions only.)
2225 ftrace FN / FILE:LINE / *ADDR
2226 Define a fast tracepoint at the given function, line, or address.
2228 * New expression syntax
2230 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2231 GDB now parses 0b101010 identically with 42.
2235 set follow-exec-mode new|same
2236 show follow-exec-mode
2237 Control whether GDB reuses the same inferior across an exec call or
2238 creates a new one. This is useful to be able to restart the old
2239 executable after the inferior having done an exec call.
2241 set default-collect EXPR, ...
2242 show default-collect
2243 Define a list of expressions to be collected at each tracepoint.
2244 This is a useful way to ensure essential items are not overlooked,
2245 such as registers or a critical global variable.
2247 set disconnected-tracing
2248 show disconnected-tracing
2249 If set to 1, the target is instructed to continue tracing if it
2250 loses its connection to GDB. If 0, the target is to stop tracing
2253 set circular-trace-buffer
2254 show circular-trace-buffer
2255 If set to on, the target is instructed to use a circular trace buffer
2256 and discard the oldest trace frames instead of stopping the trace due
2257 to a full trace buffer. If set to off, the trace stops when the buffer
2258 fills up. Some targets may not support this.
2260 set script-extension off|soft|strict
2261 show script-extension
2262 If set to "off", the debugger does not perform any script language
2263 recognition, and all sourced files are assumed to be GDB scripts.
2264 If set to "soft" (the default), files are sourced according to
2265 filename extension, falling back to GDB scripts if the first
2267 If set to "strict", files are sourced according to filename extension.
2269 set ada trust-PAD-over-XVS on|off
2270 show ada trust-PAD-over-XVS
2271 If off, activate a workaround against a bug in the debugging information
2272 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2273 the GCC sources for more information about the GNAT encoding and
2274 PAD types in particular). It is always safe to set this option to
2275 off, but this introduces a slight performance penalty. The default
2278 * Python API Improvements
2280 ** GDB provides the new class gdb.LazyString. This is useful in
2281 some pretty-printing cases. The new method gdb.Value.lazy_string
2282 provides a simple way to create objects of this type.
2284 ** The fields returned by gdb.Type.fields now have an
2285 `is_base_class' attribute.
2287 ** The new method gdb.Type.range returns the range of an array type.
2289 ** The new method gdb.parse_and_eval can be used to parse and
2290 evaluate an expression.
2292 * New remote packets
2295 Define a trace state variable.
2298 Get the current value of a trace state variable.
2301 Set desired tracing behavior upon disconnection.
2304 Set the trace buffer to be linear or circular.
2307 Get data about the tracepoints currently in use.
2311 Process record now works correctly with hardware watchpoints.
2313 Multiple bug fixes have been made to the mips-irix port, making it
2314 much more reliable. In particular:
2315 - Debugging threaded applications is now possible again. Previously,
2316 GDB would hang while starting the program, or while waiting for
2317 the program to stop at a breakpoint.
2318 - Attaching to a running process no longer hangs.
2319 - An error occurring while loading a core file has been fixed.
2320 - Changing the value of the PC register now works again. This fixes
2321 problems observed when using the "jump" command, or when calling
2322 a function from GDB, or even when assigning a new value to $pc.
2323 - With the "finish" and "return" commands, the return value for functions
2324 returning a small array is now correctly printed.
2325 - It is now possible to break on shared library code which gets executed
2326 during a shared library init phase (code executed while executing
2327 their .init section). Previously, the breakpoint would have no effect.
2328 - GDB is now able to backtrace through the signal handler for
2329 non-threaded programs.
2331 PIE (Position Independent Executable) programs debugging is now supported.
2332 This includes debugging execution of PIC (Position Independent Code) shared
2333 libraries although for that, it should be possible to run such libraries as an
2336 *** Changes in GDB 7.0
2338 * GDB now has an interface for JIT compilation. Applications that
2339 dynamically generate code can create symbol files in memory and register
2340 them with GDB. For users, the feature should work transparently, and
2341 for JIT developers, the interface is documented in the GDB manual in the
2342 "JIT Compilation Interface" chapter.
2344 * Tracepoints may now be conditional. The syntax is as for
2345 breakpoints; either an "if" clause appended to the "trace" command,
2346 or the "condition" command is available. GDB sends the condition to
2347 the target for evaluation using the same bytecode format as is used
2348 for tracepoint actions.
2350 * The disassemble command now supports: an optional /r modifier, print the
2351 raw instructions in hex as well as in symbolic form, and an optional /m
2352 modifier to print mixed source+assembly.
2354 * Process record and replay
2356 In a architecture environment that supports ``process record and
2357 replay'', ``process record and replay'' target can record a log of
2358 the process execution, and replay it with both forward and reverse
2361 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2362 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2363 set execution-direction {forward|reverse}, for targets that support
2366 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2367 feature is available with a native GDB running on kernel version
2370 * GDB now has support for multi-byte and wide character sets on the
2371 target. Strings whose character type is wchar_t, char16_t, or
2372 char32_t are now correctly printed. GDB supports wide- and unicode-
2373 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2374 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2375 `printf'. This feature requires iconv to work properly; if your
2376 system does not have a working iconv, GDB can use GNU libiconv. See
2377 the installation instructions for more information.
2379 * GDB now supports automatic retrieval of shared library files from
2380 remote targets. To use this feature, specify a system root that begins
2381 with the `remote:' prefix, either via the `set sysroot' command or via
2382 the `--with-sysroot' configure-time option.
2384 * "info sharedlibrary" now takes an optional regex of libraries to show,
2385 and it now reports if a shared library has no debugging information.
2387 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2388 now complete on file names.
2390 * When completing in expressions, gdb will attempt to limit
2391 completions to allowable structure or union fields, where appropriate.
2392 For instance, consider:
2394 # struct example { int f1; double f2; };
2395 # struct example variable;
2398 If the user types TAB at the end of this command line, the available
2399 completions will be "f1" and "f2".
2401 * Inlined functions are now supported. They show up in backtraces, and
2402 the "step", "next", and "finish" commands handle them automatically.
2404 * GDB now supports the token-splicing (##) and stringification (#)
2405 operators when expanding macros. It also supports variable-arity
2408 * GDB now supports inspecting extra signal information, exported by
2409 the new $_siginfo convenience variable. The feature is currently
2410 implemented on linux ARM, i386 and amd64.
2412 * GDB can now display the VFP floating point registers and NEON vector
2413 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2414 can provide these registers (requires Linux 2.6.30 or later). Remote
2415 and simulator targets may also provide them.
2417 * New remote packets
2420 Search memory for a sequence of bytes.
2423 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2424 operation over reliable transport links. Use of this packet is
2425 controlled by the `set remote noack-packet' command.
2428 Kill the process with the specified process ID. Use this in preference
2429 to `k' when multiprocess protocol extensions are supported.
2432 Obtains additional operating system information
2436 Read or write additional signal information.
2438 * Removed remote protocol undocumented extension
2440 An undocumented extension to the remote protocol's `S' stop reply
2441 packet that permited the stub to pass a process id was removed.
2442 Remote servers should use the `T' stop reply packet instead.
2444 * GDB now supports multiple function calling conventions according to the
2445 DWARF-2 DW_AT_calling_convention function attribute.
2447 * The SH target utilizes the aforementioned change to distinguish between gcc
2448 and Renesas calling convention. It also adds the new CLI commands
2449 `set/show sh calling-convention'.
2451 * GDB can now read compressed debug sections, as produced by GNU gold
2452 with the --compress-debug-sections=zlib flag.
2454 * 64-bit core files are now supported on AIX.
2456 * Thread switching is now supported on Tru64.
2458 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2459 which will be allocated using malloc later in program execution.
2461 * The qXfer:libraries:read remote procotol packet now allows passing a
2462 list of section offsets.
2464 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2465 conditions handling signals delivered during attach or thread creation
2466 have also been fixed.
2468 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2469 From the user's standpoint, all unqualified instances of True and False
2470 are treated as the standard definitions, regardless of context.
2472 * GDB now parses C++ symbol and type names more flexibly. For
2475 template<typename T> class C { };
2478 GDB will now correctly handle all of:
2480 ptype C<char const *>
2481 ptype C<char const*>
2482 ptype C<const char *>
2483 ptype C<const char*>
2485 * New features in the GDB remote stub, gdbserver
2487 - The "--wrapper" command-line argument tells gdbserver to use a
2488 wrapper program to launch programs for debugging.
2490 - On PowerPC and S/390 targets, it is now possible to use a single
2491 gdbserver executable to debug both 32-bit and 64-bit programs.
2492 (This requires gdbserver itself to be built as a 64-bit executable.)
2494 - gdbserver uses the new noack protocol mode for TCP connections to
2495 reduce communications latency, if also supported and enabled in GDB.
2497 - Support for the sparc64-linux-gnu target is now included in
2500 - The amd64-linux build of gdbserver now supports debugging both
2501 32-bit and 64-bit programs.
2503 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2504 now support hardware watchpoints, and will use them automatically
2509 GDB now has support for scripting using Python. Whether this is
2510 available is determined at configure time.
2512 New GDB commands can now be written in Python.
2514 * Ada tasking support
2516 Ada tasks can now be inspected in GDB. The following commands have
2520 Print the list of Ada tasks.
2522 Print detailed information about task number N.
2524 Print the task number of the current task.
2526 Switch the context of debugging to task number N.
2528 * Support for user-defined prefixed commands. The "define" command can
2529 add new commands to existing prefixes, e.g. "target".
2531 * Multi-inferior, multi-process debugging.
2533 GDB now has generalized support for multi-inferior debugging. See
2534 "Debugging Multiple Inferiors" in the manual for more information.
2535 Although availability still depends on target support, the command
2536 set is more uniform now. The GNU/Linux specific multi-forks support
2537 has been migrated to this new framework. This implied some user
2538 visible changes; see "New commands" and also "Removed commands"
2541 * Target descriptions can now describe the target OS ABI. See the
2542 "Target Description Format" section in the user manual for more
2545 * Target descriptions can now describe "compatible" architectures
2546 to indicate that the target can execute applications for a different
2547 architecture in addition to those for the main target architecture.
2548 See the "Target Description Format" section in the user manual for
2551 * Multi-architecture debugging.
2553 GDB now includes general supports for debugging applications on
2554 hybrid systems that use more than one single processor architecture
2555 at the same time. Each such hybrid architecture still requires
2556 specific support to be added. The only hybrid architecture supported
2557 in this version of GDB is the Cell Broadband Engine.
2559 * GDB now supports integrated debugging of Cell/B.E. applications that
2560 use both the PPU and SPU architectures. To enable support for hybrid
2561 Cell/B.E. debugging, you need to configure GDB to support both the
2562 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2563 --enable-targets configure option.
2565 * Non-stop mode debugging.
2567 For some targets, GDB now supports an optional mode of operation in
2568 which you can examine stopped threads while other threads continue
2569 to execute freely. This is referred to as non-stop mode, with the
2570 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2571 section in the user manual for more information.
2573 To be able to support remote non-stop debugging, a remote stub needs
2574 to implement the non-stop mode remote protocol extensions, as
2575 described in the "Remote Non-Stop" section of the user manual. The
2576 GDB remote stub, gdbserver, has been adjusted to support these
2577 extensions on linux targets.
2579 * New commands (for set/show, see "New options" below)
2581 catch syscall [NAME(S) | NUMBER(S)]
2582 Catch system calls. Arguments, which should be names of system
2583 calls or their numbers, mean catch only those syscalls. Without
2584 arguments, every syscall will be caught. When the inferior issues
2585 any of the specified syscalls, GDB will stop and announce the system
2586 call, both when it is called and when its call returns. This
2587 feature is currently available with a native GDB running on the
2588 Linux Kernel, under the following architectures: x86, x86_64,
2589 PowerPC and PowerPC64.
2591 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2593 Search memory for a sequence of bytes.
2595 maint set python print-stack
2596 maint show python print-stack
2597 Show a stack trace when an error is encountered in a Python script.
2600 Invoke CODE by passing it to the Python interpreter.
2605 These allow macros to be defined, undefined, and listed
2609 Show operating system information about processes.
2612 List the inferiors currently under GDB's control.
2615 Switch focus to inferior number NUM.
2618 Detach from inferior number NUM.
2621 Kill inferior number NUM.
2625 set spu stop-on-load
2626 show spu stop-on-load
2627 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2629 set spu auto-flush-cache
2630 show spu auto-flush-cache
2631 Control whether to automatically flush the software-managed cache
2632 during Cell/B.E. debugging.
2634 set sh calling-convention
2635 show sh calling-convention
2636 Control the calling convention used when calling SH target functions.
2639 show debug timestamp
2640 Control display of timestamps with GDB debugging output.
2642 set disassemble-next-line
2643 show disassemble-next-line
2644 Control display of disassembled source lines or instructions when
2647 set remote noack-packet
2648 show remote noack-packet
2649 Set/show the use of remote protocol QStartNoAckMode packet. See above
2650 under "New remote packets."
2652 set remote query-attached-packet
2653 show remote query-attached-packet
2654 Control use of remote protocol `qAttached' (query-attached) packet.
2656 set remote read-siginfo-object
2657 show remote read-siginfo-object
2658 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2661 set remote write-siginfo-object
2662 show remote write-siginfo-object
2663 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2666 set remote reverse-continue
2667 show remote reverse-continue
2668 Control use of remote protocol 'bc' (reverse-continue) packet.
2670 set remote reverse-step
2671 show remote reverse-step
2672 Control use of remote protocol 'bs' (reverse-step) packet.
2674 set displaced-stepping
2675 show displaced-stepping
2676 Control displaced stepping mode. Displaced stepping is a way to
2677 single-step over breakpoints without removing them from the debuggee.
2678 Also known as "out-of-line single-stepping".
2681 show debug displaced
2682 Control display of debugging info for displaced stepping.
2684 maint set internal-error
2685 maint show internal-error
2686 Control what GDB does when an internal error is detected.
2688 maint set internal-warning
2689 maint show internal-warning
2690 Control what GDB does when an internal warning is detected.
2695 Use a wrapper program to launch programs for debugging.
2697 set multiple-symbols (all|ask|cancel)
2698 show multiple-symbols
2699 The value of this variable can be changed to adjust the debugger behavior
2700 when an expression or a breakpoint location contains an ambiguous symbol
2701 name (an overloaded function name, for instance).
2703 set breakpoint always-inserted
2704 show breakpoint always-inserted
2705 Keep breakpoints always inserted in the target, as opposed to inserting
2706 them when resuming the target, and removing them when the target stops.
2707 This option can improve debugger performance on slow remote targets.
2709 set arm fallback-mode (arm|thumb|auto)
2710 show arm fallback-mode
2711 set arm force-mode (arm|thumb|auto)
2713 These commands control how ARM GDB determines whether instructions
2714 are ARM or Thumb. The default for both settings is auto, which uses
2715 the current CPSR value for instructions without symbols; previous
2716 versions of GDB behaved as if "set arm fallback-mode arm".
2718 set disable-randomization
2719 show disable-randomization
2720 Standalone programs run with the virtual address space randomization enabled
2721 by default on some platforms. This option keeps the addresses stable across
2722 multiple debugging sessions.
2726 Control whether other threads are stopped or not when some thread hits
2731 Requests that asynchronous execution is enabled in the target, if available.
2732 In this case, it's possible to resume target in the background, and interact
2733 with GDB while the target is running. "show target-async" displays the
2734 current state of asynchronous execution of the target.
2736 set target-wide-charset
2737 show target-wide-charset
2738 The target-wide-charset is the name of the character set that GDB
2739 uses when printing characters whose type is wchar_t.
2741 set tcp auto-retry (on|off)
2743 set tcp connect-timeout
2744 show tcp connect-timeout
2745 These commands allow GDB to retry failed TCP connections to a remote stub
2746 with a specified timeout period; this is useful if the stub is launched
2747 in parallel with GDB but may not be ready to accept connections immediately.
2749 set libthread-db-search-path
2750 show libthread-db-search-path
2751 Control list of directories which GDB will search for appropriate
2754 set schedule-multiple (on|off)
2755 show schedule-multiple
2756 Allow GDB to resume all threads of all processes or only threads of
2757 the current process.
2761 Use more aggressive caching for accesses to the stack. This improves
2762 performance of remote debugging (particularly backtraces) without
2763 affecting correctness.
2765 set interactive-mode (on|off|auto)
2766 show interactive-mode
2767 Control whether GDB runs in interactive mode (on) or not (off).
2768 When in interactive mode, GDB waits for the user to answer all
2769 queries. Otherwise, GDB does not wait and assumes the default
2770 answer. When set to auto (the default), GDB determines which
2771 mode to use based on the stdin settings.
2776 For program forks, this is replaced by the new more generic `info
2777 inferiors' command. To list checkpoints, you can still use the
2778 `info checkpoints' command, which was an alias for the `info forks'
2782 Replaced by the new `inferior' command. To switch between
2783 checkpoints, you can still use the `restart' command, which was an
2784 alias for the `fork' command.
2787 This is removed, since some targets don't have a notion of
2788 processes. To switch between processes, you can still use the
2789 `inferior' command using GDB's own inferior number.
2792 For program forks, this is replaced by the new more generic `kill
2793 inferior' command. To delete a checkpoint, you can still use the
2794 `delete checkpoint' command, which was an alias for the `delete
2798 For program forks, this is replaced by the new more generic `detach
2799 inferior' command. To detach a checkpoint, you can still use the
2800 `detach checkpoint' command, which was an alias for the `detach
2803 * New native configurations
2805 x86/x86_64 Darwin i[34567]86-*-darwin*
2807 x86_64 MinGW x86_64-*-mingw*
2811 Lattice Mico32 lm32-*
2812 x86 DICOS i[34567]86-*-dicos*
2813 x86_64 DICOS x86_64-*-dicos*
2816 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2817 (mingw32ce) debugging.
2823 These commands were actually not implemented on any target.
2825 *** Changes in GDB 6.8
2827 * New native configurations
2829 NetBSD/hppa hppa*-*netbsd*
2830 Xtensa GNU/Linux xtensa*-*-linux*
2834 NetBSD/hppa hppa*-*-netbsd*
2835 Xtensa GNU/Lunux xtensa*-*-linux*
2837 * Change in command line behavior -- corefiles vs. process ids.
2839 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2840 attaching to process NUMBER fails, GDB no longer attempts to open a
2841 core file named NUMBER. Attaching to a program using the -c option
2842 is no longer supported. Instead, use the '-p' or '--pid' options.
2844 * GDB can now be built as a native debugger for debugging Windows x86
2845 (mingw32) Portable Executable (PE) programs.
2847 * Pending breakpoints no longer change their number when their address
2850 * GDB now supports breakpoints with multiple locations,
2851 including breakpoints on C++ constructors, inside C++ templates,
2852 and in inlined functions.
2854 * GDB's ability to debug optimized code has been improved. GDB more
2855 accurately identifies function bodies and lexical blocks that occupy
2856 more than one contiguous range of addresses.
2858 * Target descriptions can now describe registers for PowerPC.
2860 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2861 registers on PowerPC targets.
2863 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2864 targets even when the libthread_db library is not available.
2866 * The GDB remote stub, gdbserver, now supports the new file transfer
2867 commands (remote put, remote get, and remote delete).
2869 * The GDB remote stub, gdbserver, now supports run and attach in
2870 extended-remote mode.
2872 * hppa*64*-*-hpux11* target broken
2873 The debugger is unable to start a program and fails with the following
2874 error: "Error trying to get information about dynamic linker".
2875 The gdb-6.7 release is also affected.
2877 * GDB now supports the --enable-targets= configure option to allow
2878 building a single GDB executable that supports multiple remote
2879 target architectures.
2881 * GDB now supports debugging C and C++ programs which use the
2882 Decimal Floating Point extension. In addition, the PowerPC target
2883 now has a set of pseudo-registers to inspect decimal float values
2884 stored in two consecutive float registers.
2886 * The -break-insert MI command can optionally create pending
2889 * Improved support for debugging Ada
2890 Many improvements to the Ada language support have been made. These
2892 - Better support for Ada2005 interface types
2893 - Improved handling of arrays and slices in general
2894 - Better support for Taft-amendment types
2895 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2897 - Improved command completion in Ada
2900 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2905 set print frame-arguments (all|scalars|none)
2906 show print frame-arguments
2907 The value of this variable can be changed to control which argument
2908 values should be printed by the debugger when displaying a frame.
2913 Transfer files to and from a remote target, and delete remote files.
2920 Transfer files to and from a remote target, and delete remote files.
2922 * New remote packets
2929 Open, close, read, write, and delete files on the remote system.
2932 Attach to an existing process on the remote system, in extended-remote
2936 Run a new process on the remote system, in extended-remote mode.
2938 *** Changes in GDB 6.7
2940 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2941 bfd, libiberty and opcodes, as revealed by static analysis donated by
2942 Coverity, Inc. (http://scan.coverity.com).
2944 * When looking up multiply-defined global symbols, GDB will now prefer the
2945 symbol definition in the current shared library if it was built using the
2946 -Bsymbolic linker option.
2948 * When the Text User Interface (TUI) is not configured, GDB will now
2949 recognize the -tui command-line option and print a message that the TUI
2952 * The GDB remote stub, gdbserver, now has lower overhead for high
2953 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2955 * GDB for MIPS targets now autodetects whether a remote target provides
2956 32-bit or 64-bit register values.
2958 * Support for C++ member pointers has been improved.
2960 * GDB now understands XML target descriptions, which specify the
2961 target's overall architecture. GDB can read a description from
2962 a local file or over the remote serial protocol.
2964 * Vectors of single-byte data use a new integer type which is not
2965 automatically displayed as character or string data.
2967 * The /s format now works with the print command. It displays
2968 arrays of single-byte integers and pointers to single-byte integers
2971 * Target descriptions can now describe target-specific registers,
2972 for architectures which have implemented the support (currently
2973 only ARM, M68K, and MIPS).
2975 * GDB and the GDB remote stub, gdbserver, now support the XScale
2978 * The GDB remote stub, gdbserver, has been updated to support
2979 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2980 has been rewritten to use the standard GDB remote protocol.
2982 * GDB can now step into C++ functions which are called through thunks.
2984 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2986 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2987 layout. It also supports a TextSeg= and DataSeg= response when only
2988 segment base addresses (rather than offsets) are available.
2990 * The /i format now outputs any trailing branch delay slot instructions
2991 immediately following the last instruction within the count specified.
2993 * The GDB remote protocol "T" stop reply packet now supports a
2994 "library" response. Combined with the new "qXfer:libraries:read"
2995 packet, this response allows GDB to debug shared libraries on targets
2996 where the operating system manages the list of loaded libraries (e.g.
2997 Windows and SymbianOS).
2999 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3000 (DLLs) on Windows and Windows CE targets.
3002 * GDB now supports a faster verification that a .debug file matches its binary
3003 according to its build-id signature, if the signature is present.
3009 Enable or disable hardware flow control (RTS/CTS) on the serial port
3010 when debugging using remote targets.
3012 set mem inaccessible-by-default
3013 show mem inaccessible-by-default
3014 If the target supplies a memory map, for instance via the remote
3015 protocol's "qXfer:memory-map:read" packet, setting this variable
3016 prevents GDB from accessing memory outside the memory map. This
3017 is useful for targets with memory mapped registers or which react
3018 badly to accesses of unmapped address space.
3020 set breakpoint auto-hw
3021 show breakpoint auto-hw
3022 If the target supplies a memory map, for instance via the remote
3023 protocol's "qXfer:memory-map:read" packet, setting this variable
3024 lets GDB use hardware breakpoints automatically for memory regions
3025 where it can not use software breakpoints. This covers both the
3026 "break" command and internal breakpoints used for other commands
3027 including "next" and "finish".
3030 catch exception unhandled
3031 Stop the program execution when Ada exceptions are raised.
3034 Stop the program execution when an Ada assertion failed.
3038 Set an alternate system root for target files. This is a more
3039 general version of "set solib-absolute-prefix", which is now
3040 an alias to "set sysroot".
3043 Provide extended SPU facility status information. This set of
3044 commands is available only when debugging the Cell/B.E. SPU
3047 * New native configurations
3049 OpenBSD/sh sh*-*openbsd*
3052 unset tdesc filename
3054 Use the specified local file as an XML target description, and do
3055 not query the target for its built-in description.
3059 OpenBSD/sh sh*-*-openbsd*
3060 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3061 Toshiba Media Processor mep-elf
3063 * New remote packets
3066 Ignore the specified signals; pass them directly to the debugged program
3067 without stopping other threads or reporting them to GDB.
3069 qXfer:features:read:
3070 Read an XML target description from the target, which describes its
3075 Read or write contents of an spufs file on the target system. These
3076 packets are available only on the Cell/B.E. SPU architecture.
3078 qXfer:libraries:read:
3079 Report the loaded shared libraries. Combined with new "T" packet
3080 response, this packet allows GDB to debug shared libraries on
3081 targets where the operating system manages the list of loaded
3082 libraries (e.g. Windows and SymbianOS).
3086 Support for these obsolete configurations has been removed.
3094 i[34567]86-*-lynxos*
3095 i[34567]86-*-netware*
3096 i[34567]86-*-sco3.2v5*
3097 i[34567]86-*-sco3.2v4*
3099 i[34567]86-*-sysv4.2*
3102 i[34567]86-*-unixware2*
3103 i[34567]86-*-unixware*
3112 * Other removed features
3119 Various m68k-only ROM monitors.
3126 Various Renesas ROM monitors and debugging interfaces for SH and
3131 Support for a Macraigor serial interface to on-chip debugging.
3132 GDB does not directly support the newer parallel or USB
3137 A debug information format. The predecessor to DWARF 2 and
3138 DWARF 3, which are still supported.
3140 Support for the HP aCC compiler on HP-UX/PA-RISC
3142 SOM-encapsulated symbolic debugging information, automatic
3143 invocation of pxdb, and the aCC custom C++ ABI. This does not
3144 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3145 with aCC can still be debugged on an assembly level.
3147 MIPS ".pdr" sections
3149 A MIPS-specific format used to describe stack frame layout
3150 in debugging information.
3154 GDB could work with an older version of Guile to debug
3155 the interpreter and Scheme programs running in it.
3157 set mips stack-arg-size
3158 set mips saved-gpreg-size
3160 Use "set mips abi" to control parameter passing for MIPS.
3162 *** Changes in GDB 6.6
3167 Cell Broadband Engine SPU spu-elf
3169 * GDB can now be configured as a cross-debugger targeting native Windows
3170 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3171 running on a Windows system over TCP/IP to debug Windows programs.
3173 * The GDB remote stub, gdbserver, has been updated to support Windows and
3174 Cygwin debugging. Both single-threaded and multi-threaded programs are
3177 * The "set trust-readonly-sections" command works again. This command was
3178 broken in GDB 6.3, 6.4, and 6.5.
3180 * The "load" command now supports writing to flash memory, if the remote
3181 stub provides the required support.
3183 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3184 longer requires symbolic debug information (e.g. DWARF-2).
3189 unset substitute-path
3190 show substitute-path
3191 Manage a list of substitution rules that GDB uses to rewrite the name
3192 of the directories where the sources are located. This can be useful
3193 for instance when the sources were moved to a different location
3194 between compilation and debugging.
3198 Print each CLI command as it is executed. Each command is prefixed with
3199 a number of `+' symbols representing the nesting depth.
3200 The source command now has a `-v' option to enable the same feature.
3204 The ARM Demon monitor support (RDP protocol, "target rdp").
3206 Kernel Object Display, an embedded debugging feature which only worked with
3207 an obsolete version of Cisco IOS.
3209 The 'set download-write-size' and 'show download-write-size' commands.
3211 * New remote packets
3214 Tell a stub about GDB client features, and request remote target features.
3215 The first feature implemented is PacketSize, which allows the target to
3216 specify the size of packets it can handle - to minimize the number of
3217 packets required and improve performance when connected to a remote
3221 Fetch an OS auxilliary vector from the remote stub. This packet is a
3222 more efficient replacement for qPart:auxv:read.
3224 qXfer:memory-map:read:
3225 Fetch a memory map from the remote stub, including information about
3226 RAM, ROM, and flash memory devices.
3231 Erase and program a flash memory device.
3233 * Removed remote packets
3236 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3237 used it, and only gdbserver implemented it.
3239 *** Changes in GDB 6.5
3243 Renesas M32C/M16C m32c-elf
3245 Morpho Technologies ms1 ms1-elf
3249 init-if-undefined Initialize a convenience variable, but
3250 only if it doesn't already have a value.
3252 The following commands are presently only implemented for native GNU/Linux:
3254 checkpoint Save a snapshot of the program state.
3256 restart <n> Return the program state to a
3257 previously saved state.
3259 info checkpoints List currently saved checkpoints.
3261 delete-checkpoint <n> Delete a previously saved checkpoint.
3263 set|show detach-on-fork Tell gdb whether to detach from a newly
3264 forked process, or to keep debugging it.
3266 info forks List forks of the user program that
3267 are available to be debugged.
3269 fork <n> Switch to debugging one of several
3270 forks of the user program that are
3271 available to be debugged.
3273 delete-fork <n> Delete a fork from the list of forks
3274 that are available to be debugged (and
3275 kill the forked process).
3277 detach-fork <n> Delete a fork from the list of forks
3278 that are available to be debugged (and
3279 allow the process to continue).
3283 Morpho Technologies ms2 ms1-elf
3285 * Improved Windows host support
3287 GDB now builds as a cross debugger hosted on i686-mingw32, including
3288 native console support, and remote communications using either
3289 network sockets or serial ports.
3291 * Improved Modula-2 language support
3293 GDB can now print most types in the Modula-2 syntax. This includes:
3294 basic types, set types, record types, enumerated types, range types,
3295 pointer types and ARRAY types. Procedure var parameters are correctly
3296 printed and hexadecimal addresses and character constants are also
3297 written in the Modula-2 syntax. Best results can be obtained by using
3298 GNU Modula-2 together with the -gdwarf-2 command line option.
3302 The ARM rdi-share module.
3304 The Netware NLM debug server.
3306 *** Changes in GDB 6.4
3308 * New native configurations
3310 OpenBSD/arm arm*-*-openbsd*
3311 OpenBSD/mips64 mips64-*-openbsd*
3315 Morpho Technologies ms1 ms1-elf
3317 * New command line options
3319 --batch-silent As for --batch, but totally silent.
3320 --return-child-result The debugger will exist with the same value
3321 the child (debugged) program exited with.
3322 --eval-command COMMAND, -ex COMMAND
3323 Execute a single GDB CLI command. This may be
3324 specified multiple times and in conjunction
3325 with the --command (-x) option.
3327 * Deprecated commands removed
3329 The following commands, that were deprecated in 2000, have been
3333 set|show arm disassembly-flavor set|show arm disassembler
3334 othernames set arm disassembler
3335 set|show remotedebug set|show debug remote
3336 set|show archdebug set|show debug arch
3337 set|show eventdebug set|show debug event
3340 * New BSD user-level threads support
3342 It is now possible to debug programs using the user-level threads
3343 library on OpenBSD and FreeBSD. Currently supported (target)
3346 FreeBSD/amd64 x86_64-*-freebsd*
3347 FreeBSD/i386 i386-*-freebsd*
3348 OpenBSD/i386 i386-*-openbsd*
3350 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3351 are not yet supported.
3353 * New support for Matsushita MN10300 w/sim added
3354 (Work in progress). mn10300-elf.
3356 * REMOVED configurations and files
3358 VxWorks and the XDR protocol *-*-vxworks
3359 Motorola MCORE mcore-*-*
3360 National Semiconductor NS32000 ns32k-*-*
3362 * New "set print array-indexes" command
3364 After turning this setting "on", GDB prints the index of each element
3365 when displaying arrays. The default is "off" to preserve the previous
3368 * VAX floating point support
3370 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3372 * User-defined command support
3374 In addition to using $arg0..$arg9 for argument passing, it is now possible
3375 to use $argc to determine now many arguments have been passed. See the
3376 section on user-defined commands in the user manual for more information.
3378 *** Changes in GDB 6.3:
3380 * New command line option
3382 GDB now accepts -l followed by a number to set the timeout for remote
3385 * GDB works with GCC -feliminate-dwarf2-dups
3387 GDB now supports a more compact representation of DWARF-2 debug
3388 information using DW_FORM_ref_addr references. These are produced
3389 by GCC with the option -feliminate-dwarf2-dups and also by some
3390 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3391 to use -feliminate-dwarf2-dups.
3393 * Internationalization
3395 When supported by the host system, GDB will be built with
3396 internationalization (libintl). The task of marking up the sources is
3397 continued, we're looking forward to our first translation.
3401 Initial support for debugging programs compiled with the GNAT
3402 implementation of the Ada programming language has been integrated
3403 into GDB. In this release, support is limited to expression evaluation.
3405 * New native configurations
3407 GNU/Linux/m32r m32r-*-linux-gnu
3411 GDB's remote protocol now includes support for the 'p' packet. This
3412 packet is used to fetch individual registers from a remote inferior.
3414 * END-OF-LIFE registers[] compatibility module
3416 GDB's internal register infrastructure has been completely rewritten.
3417 The new infrastructure making possible the implementation of key new
3418 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3421 GDB 6.3 will be the last release to include the the registers[]
3422 compatibility module that allowed out-of-date configurations to
3423 continue to work. This change directly impacts the following
3433 powerpc bdm protocol
3435 Unless there is activity to revive these configurations, they will be
3436 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3438 * OBSOLETE configurations and files
3440 Configurations that have been declared obsolete in this release have
3441 been commented out. Unless there is activity to revive these
3442 configurations, the next release of GDB will have their sources
3443 permanently REMOVED.
3452 *** Changes in GDB 6.2.1:
3454 * MIPS `break main; run' gave an heuristic-fence-post warning
3456 When attempting to run even a simple program, a warning about
3457 heuristic-fence-post being hit would be reported. This problem has
3460 * MIPS IRIX 'long double' crashed GDB
3462 When examining a long double variable, GDB would get a segmentation
3463 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3464 IRIX long double values).
3468 A bug in the VAX stack code was causing problems with the "next"
3469 command. This problem has been fixed.
3471 *** Changes in GDB 6.2:
3473 * Fix for ``many threads''
3475 On GNU/Linux systems that use the NPTL threads library, a program
3476 rapidly creating and deleting threads would confuse GDB leading to the
3479 ptrace: No such process.
3480 thread_db_get_info: cannot get thread info: generic error
3482 This problem has been fixed.
3484 * "-async" and "-noasync" options removed.
3486 Support for the broken "-noasync" option has been removed (it caused
3489 * New ``start'' command.
3491 This command runs the program until the begining of the main procedure.
3493 * New BSD Kernel Data Access Library (libkvm) interface
3495 Using ``target kvm'' it is now possible to debug kernel core dumps and
3496 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3497 platforms. Currently supported (native-only) configurations are:
3499 FreeBSD/amd64 x86_64-*-freebsd*
3500 FreeBSD/i386 i?86-*-freebsd*
3501 NetBSD/i386 i?86-*-netbsd*
3502 NetBSD/m68k m68*-*-netbsd*
3503 NetBSD/sparc sparc-*-netbsd*
3504 OpenBSD/amd64 x86_64-*-openbsd*
3505 OpenBSD/i386 i?86-*-openbsd*
3506 OpenBSD/m68k m68*-openbsd*
3507 OpenBSD/sparc sparc-*-openbsd*
3509 * Signal trampoline code overhauled
3511 Many generic problems with GDB's signal handling code have been fixed.
3512 These include: backtraces through non-contiguous stacks; recognition
3513 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3514 call; backtrace through a signal trampoline; step into and out of
3515 signal handlers; and single-stepping in the signal trampoline.
3517 Please note that kernel bugs are a limiting factor here. These
3518 features have been shown to work on an s390 GNU/Linux system that
3519 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3521 * Cygwin support for DWARF 2 added.
3523 * New native configurations
3525 GNU/Linux/hppa hppa*-*-linux*
3526 OpenBSD/hppa hppa*-*-openbsd*
3527 OpenBSD/m68k m68*-*-openbsd*
3528 OpenBSD/m88k m88*-*-openbsd*
3529 OpenBSD/powerpc powerpc-*-openbsd*
3530 NetBSD/vax vax-*-netbsd*
3531 OpenBSD/vax vax-*-openbsd*
3533 * END-OF-LIFE frame compatibility module
3535 GDB's internal frame infrastructure has been completely rewritten.
3536 The new infrastructure making it possible to support key new features
3537 including DWARF 2 Call Frame Information. To aid in the task of
3538 migrating old configurations to this new infrastructure, a
3539 compatibility module, that allowed old configurations to continue to
3540 work, was also included.
3542 GDB 6.2 will be the last release to include this frame compatibility
3543 module. This change directly impacts the following configurations:
3553 Unless there is activity to revive these configurations, they will be
3554 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3556 * REMOVED configurations and files
3558 Sun 3, running SunOS 3 m68*-*-sunos3*
3559 Sun 3, running SunOS 4 m68*-*-sunos4*
3560 Sun 2, running SunOS 3 m68000-*-sunos3*
3561 Sun 2, running SunOS 4 m68000-*-sunos4*
3562 Motorola 680x0 running LynxOS m68*-*-lynxos*
3563 AT&T 3b1/Unix pc m68*-att-*
3564 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3565 decstation mips-dec-* mips-little-*
3566 riscos mips-*-riscos* mips-*-sysv*
3567 sonymips mips-sony-*
3568 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3570 *** Changes in GDB 6.1.1:
3572 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3574 The TUI (Text-mode User Interface) is now built as part of a default
3575 GDB configuration. It is enabled by either selecting the TUI with the
3576 command line option "-i=tui" or by running the separate "gdbtui"
3577 program. For more information on the TUI, see the manual "Debugging
3580 * Pending breakpoint support (also included in GDB 6.1)
3582 Support has been added to allow you to specify breakpoints in shared
3583 libraries that have not yet been loaded. If a breakpoint location
3584 cannot be found, and the "breakpoint pending" option is set to auto,
3585 GDB queries you if you wish to make the breakpoint pending on a future
3586 shared-library load. If and when GDB resolves the breakpoint symbol,
3587 the pending breakpoint is removed as one or more regular breakpoints
3590 Pending breakpoints are very useful for GCJ Java debugging.
3592 * Fixed ISO-C build problems
3594 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3595 non ISO-C code that stopped them being built using a more strict ISO-C
3596 compiler (e.g., IBM's C compiler).
3598 * Fixed build problem on IRIX 5
3600 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3601 wasn't able to compile compile on an IRIX 5 system.
3603 * Added execute permission to gdb/gdbserver/configure
3605 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3606 permission. This bug would cause configure to fail on a number of
3607 systems (Solaris, IRIX). Ref: server/519.
3609 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3611 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3612 has been updated to use constant array sizes.
3614 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3616 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3617 its generated DWARF Call Frame Info. This encoding was causing GDB to
3618 panic, that panic has been fixed. Ref: gdb/1628.
3620 * Fixed a problem when examining parameters in shared library code.
3622 When examining parameters in optimized shared library code generated
3623 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3624 not available''. GDB now correctly displays the variable's value.
3626 *** Changes in GDB 6.1:
3628 * Removed --with-mmalloc
3630 Support for the mmalloc memory manager has been removed, as it
3631 conflicted with the internal gdb byte cache.
3633 * Changes in AMD64 configurations
3635 The AMD64 target now includes the %cs and %ss registers. As a result
3636 the AMD64 remote protocol has changed; this affects the floating-point
3637 and SSE registers. If you rely on those registers for your debugging,
3638 you should upgrade gdbserver on the remote side.
3640 * Revised SPARC target
3642 The SPARC target has been completely revised, incorporating the
3643 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3644 support for LynxOS and SunOS 4 has been dropped. Calling functions
3645 from within GDB on operating systems with a non-executable stack
3646 (Solaris, OpenBSD) now works.
3650 GDB has a new C++ demangler which does a better job on the mangled
3651 names generated by current versions of g++. It also runs faster, so
3652 with this and other changes gdb should now start faster on large C++
3655 * DWARF 2 Location Expressions
3657 GDB support for location expressions has been extended to support function
3658 arguments and frame bases. Older versions of GDB could crash when they
3661 * C++ nested types and namespaces
3663 GDB's support for nested types and namespaces in C++ has been
3664 improved, especially if you use the DWARF 2 debugging format. (This
3665 is the default for recent versions of GCC on most platforms.)
3666 Specifically, if you have a class "Inner" defined within a class or
3667 namespace "Outer", then GDB realizes that the class's name is
3668 "Outer::Inner", not simply "Inner". This should greatly reduce the
3669 frequency of complaints about not finding RTTI symbols. In addition,
3670 if you are stopped at inside of a function defined within a namespace,
3671 GDB modifies its name lookup accordingly.
3673 * New native configurations
3675 NetBSD/amd64 x86_64-*-netbsd*
3676 OpenBSD/amd64 x86_64-*-openbsd*
3677 OpenBSD/alpha alpha*-*-openbsd*
3678 OpenBSD/sparc sparc-*-openbsd*
3679 OpenBSD/sparc64 sparc64-*-openbsd*
3681 * New debugging protocols
3683 M32R with SDI protocol m32r-*-elf*
3685 * "set prompt-escape-char" command deleted.
3687 The command "set prompt-escape-char" has been deleted. This command,
3688 and its very obscure effet on GDB's prompt, was never documented,
3689 tested, nor mentioned in the NEWS file.
3691 * OBSOLETE configurations and files
3693 Configurations that have been declared obsolete in this release have
3694 been commented out. Unless there is activity to revive these
3695 configurations, the next release of GDB will have their sources
3696 permanently REMOVED.
3698 Sun 3, running SunOS 3 m68*-*-sunos3*
3699 Sun 3, running SunOS 4 m68*-*-sunos4*
3700 Sun 2, running SunOS 3 m68000-*-sunos3*
3701 Sun 2, running SunOS 4 m68000-*-sunos4*
3702 Motorola 680x0 running LynxOS m68*-*-lynxos*
3703 AT&T 3b1/Unix pc m68*-att-*
3704 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3705 decstation mips-dec-* mips-little-*
3706 riscos mips-*-riscos* mips-*-sysv*
3707 sonymips mips-sony-*
3708 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3710 * REMOVED configurations and files
3712 SGI Irix-4.x mips-sgi-irix4 or iris4
3713 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3714 Z8000 simulator z8k-zilog-none or z8ksim
3715 Matsushita MN10200 w/simulator mn10200-*-*
3716 H8/500 simulator h8500-hitachi-hms or h8500hms
3717 HP/PA running BSD hppa*-*-bsd*
3718 HP/PA running OSF/1 hppa*-*-osf*
3719 HP/PA Pro target hppa*-*-pro*
3720 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3721 386BSD i[3456]86-*-bsd*
3722 Sequent family i[3456]86-sequent-sysv4*
3723 i[3456]86-sequent-sysv*
3724 i[3456]86-sequent-bsd*
3725 SPARC running LynxOS sparc-*-lynxos*
3726 SPARC running SunOS 4 sparc-*-sunos4*
3727 Tsqware Sparclet sparclet-*-*
3728 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3730 *** Changes in GDB 6.0:
3734 Support for debugging the Objective-C programming language has been
3735 integrated into GDB.
3737 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3739 DWARF 2's Call Frame Information makes available compiler generated
3740 information that more exactly describes the program's run-time stack.
3741 By using this information, GDB is able to provide more robust stack
3744 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3745 have been updated to use a new backtrace mechanism which includes
3746 DWARF 2 CFI support.
3750 GDB's remote protocol has been extended to include support for hosted
3751 file I/O (where the remote target uses GDB's file system). See GDB's
3752 remote protocol documentation for details.
3754 * All targets using the new architecture framework.
3756 All of GDB's targets have been updated to use the new internal
3757 architecture framework. The way is now open for future GDB releases
3758 to include cross-architecture native debugging support (i386 on amd64,
3761 * GNU/Linux's Thread Local Storage (TLS)
3763 GDB now includes support for for the GNU/Linux implementation of
3764 per-thread variables.
3766 * GNU/Linux's Native POSIX Thread Library (NPTL)
3768 GDB's thread code has been updated to work with either the new
3769 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3771 * Separate debug info.
3773 GDB, in conjunction with BINUTILS, now supports a mechanism for
3774 automatically loading debug information from a separate file. Instead
3775 of shipping full debug and non-debug versions of system libraries,
3776 system integrators can now instead ship just the stripped libraries
3777 and optional debug files.
3779 * DWARF 2 Location Expressions
3781 DWARF 2 Location Expressions allow the compiler to more completely
3782 describe the location of variables (even in optimized code) to the
3785 GDB now includes preliminary support for location expressions (support
3786 for DW_OP_piece is still missing).
3790 A number of long standing bugs that caused GDB to die while starting a
3791 Java application have been fixed. GDB's Java support is now
3792 considered "useable".
3794 * GNU/Linux support for fork, vfork, and exec.
3796 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3797 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3800 * GDB supports logging output to a file
3802 There are two new commands, "set logging" and "show logging", which can be
3803 used to capture GDB's output to a file.
3805 * The meaning of "detach" has changed for gdbserver
3807 The "detach" command will now resume the application, as documented. To
3808 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3811 * d10v, m68hc11 `regs' command deprecated
3813 The `info registers' command has been updated so that it displays the
3814 registers using a format identical to the old `regs' command.
3818 A new command, "maint set profile on/off", has been added. This command can
3819 be used to enable or disable profiling while running GDB, to profile a
3820 session or a set of commands. In addition there is a new configure switch,
3821 "--enable-profiling", which will cause GDB to be compiled with profiling
3822 data, for more informative profiling results.
3824 * Default MI syntax changed to "mi2".
3826 The default MI (machine interface) syntax, enabled by the command line
3827 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3828 "mi1", can be enabled by specifying the option "-i=mi1".
3830 Support for the original "mi0" syntax (included in GDB 5.0) has been
3833 Fix for gdb/192: removed extraneous space when displaying frame level.
3834 Fix for gdb/672: update changelist is now output in mi list format.
3835 Fix for gdb/702: a -var-assign that updates the value now shows up
3836 in a subsequent -var-update.
3838 * New native configurations.
3840 FreeBSD/amd64 x86_64-*-freebsd*
3842 * Multi-arched targets.
3844 HP/PA HPUX11 hppa*-*-hpux*
3845 Renesas M32R/D w/simulator m32r-*-elf*
3847 * OBSOLETE configurations and files
3849 Configurations that have been declared obsolete in this release have
3850 been commented out. Unless there is activity to revive these
3851 configurations, the next release of GDB will have their sources
3852 permanently REMOVED.
3854 Z8000 simulator z8k-zilog-none or z8ksim
3855 Matsushita MN10200 w/simulator mn10200-*-*
3856 H8/500 simulator h8500-hitachi-hms or h8500hms
3857 HP/PA running BSD hppa*-*-bsd*
3858 HP/PA running OSF/1 hppa*-*-osf*
3859 HP/PA Pro target hppa*-*-pro*
3860 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3861 Sequent family i[3456]86-sequent-sysv4*
3862 i[3456]86-sequent-sysv*
3863 i[3456]86-sequent-bsd*
3864 Tsqware Sparclet sparclet-*-*
3865 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3867 * REMOVED configurations and files
3870 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3871 IBM AIX PS/2 i[3456]86-*-aix
3872 i386 running Mach 3.0 i[3456]86-*-mach3*
3873 i386 running Mach i[3456]86-*-mach*
3874 i386 running OSF/1 i[3456]86-*osf1mk*
3875 HP/Apollo 68k Family m68*-apollo*-sysv*,
3877 m68*-hp-bsd*, m68*-hp-hpux*
3878 Argonaut Risc Chip (ARC) arc-*-*
3879 Mitsubishi D30V d30v-*-*
3880 Fujitsu FR30 fr30-*-elf*
3881 OS/9000 i[34]86-*-os9k
3882 I960 with MON960 i960-*-coff
3884 * MIPS $fp behavior changed
3886 The convenience variable $fp, for the MIPS, now consistently returns
3887 the address of the current frame's base. Previously, depending on the
3888 context, $fp could refer to either $sp or the current frame's base
3889 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3890 The GNU Source-Level Debugger''.
3892 *** Changes in GDB 5.3:
3894 * GNU/Linux shared library multi-threaded performance improved.
3896 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3897 `/proc', in preference to `ptrace' for memory reads. This may result
3898 in an improvement in the start-up time of multi-threaded, shared
3899 library applications when run under GDB. One GDB user writes: ``loads
3900 shared libs like mad''.
3902 * ``gdbserver'' now supports multi-threaded applications on some targets
3904 Support for debugging multi-threaded applications which use
3905 the GNU/Linux LinuxThreads package has been added for
3906 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3907 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3909 * GDB now supports C/C++ preprocessor macros.
3911 GDB now expands preprocessor macro invocations in C/C++ expressions,
3912 and provides various commands for showing macro definitions and how
3915 The new command `macro expand EXPRESSION' expands any macro
3916 invocations in expression, and shows the result.
3918 The new command `show macro MACRO-NAME' shows the definition of the
3919 macro named MACRO-NAME, and where it was defined.
3921 Most compilers don't include information about macros in the debugging
3922 information by default. In GCC 3.1, for example, you need to compile
3923 your program with the options `-gdwarf-2 -g3'. If the macro
3924 information is present in the executable, GDB will read it.
3926 * Multi-arched targets.
3928 DEC Alpha (partial) alpha*-*-*
3929 DEC VAX (partial) vax-*-*
3931 National Semiconductor NS32000 (partial) ns32k-*-*
3932 Motorola 68000 (partial) m68k-*-*
3933 Motorola MCORE mcore-*-*
3937 Fujitsu FRV architecture added by Red Hat frv*-*-*
3940 * New native configurations
3942 Alpha NetBSD alpha*-*-netbsd*
3943 SH NetBSD sh*-*-netbsdelf*
3944 MIPS NetBSD mips*-*-netbsd*
3945 UltraSPARC NetBSD sparc64-*-netbsd*
3947 * OBSOLETE configurations and files
3949 Configurations that have been declared obsolete in this release have
3950 been commented out. Unless there is activity to revive these
3951 configurations, the next release of GDB will have their sources
3952 permanently REMOVED.
3954 Mitsubishi D30V d30v-*-*
3955 OS/9000 i[34]86-*-os9k
3956 IBM AIX PS/2 i[3456]86-*-aix
3957 Fujitsu FR30 fr30-*-elf*
3958 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3959 Argonaut Risc Chip (ARC) arc-*-*
3960 i386 running Mach 3.0 i[3456]86-*-mach3*
3961 i386 running Mach i[3456]86-*-mach*
3962 i386 running OSF/1 i[3456]86-*osf1mk*
3963 HP/Apollo 68k Family m68*-apollo*-sysv*,
3965 m68*-hp-bsd*, m68*-hp-hpux*
3966 I960 with MON960 i960-*-coff
3968 * OBSOLETE languages
3970 CHILL, a Pascal like language used by telecommunications companies.
3972 * REMOVED configurations and files
3974 AMD 29k family via UDI a29k-amd-udi, udi29k
3975 A29K VxWorks a29k-*-vxworks
3976 AMD 29000 embedded, using EBMON a29k-none-none
3977 AMD 29000 embedded with COFF a29k-none-coff
3978 AMD 29000 embedded with a.out a29k-none-aout
3980 testsuite/gdb.hp/gdb.threads-hp/ directory
3982 * New command "set max-user-call-depth <nnn>"
3984 This command allows the user to limit the call depth of user-defined
3985 commands. The default is 1024.
3987 * Changes in FreeBSD/i386 native debugging.
3989 Support for the "generate-core-file" has been added.
3991 * New commands "dump", "append", and "restore".
3993 These commands allow data to be copied from target memory
3994 to a bfd-format or binary file (dump and append), and back
3995 from a file into memory (restore).
3997 * Improved "next/step" support on multi-processor Alpha Tru64.
3999 The previous single-step mechanism could cause unpredictable problems,
4000 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4001 of a software single-step mechanism prevents this.
4003 *** Changes in GDB 5.2.1:
4011 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4012 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4013 Fix, by Joel Brobecker imported from mainline.
4015 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4016 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4017 Fix, by Fred Fish, imported from mainline.
4019 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4020 Surprisingly enough, it works now.
4021 By Michal Ludvig, imported from mainline.
4023 i386 hardware watchpoint support:
4024 avoid misses on second run for some targets.
4025 By Pierre Muller, imported from mainline.
4027 *** Changes in GDB 5.2:
4029 * New command "set trust-readonly-sections on[off]".
4031 This command is a hint that tells gdb that read-only sections
4032 really are read-only (ie. that their contents will not change).
4033 In this mode, gdb will go to the object file rather than the
4034 target to read memory from read-only sections (such as ".text").
4035 This can be a significant performance improvement on some
4036 (notably embedded) targets.
4038 * New command "generate-core-file" (or "gcore").
4040 This new gdb command allows the user to drop a core file of the child
4041 process state at any time. So far it's been implemented only for
4042 GNU/Linux and Solaris, but should be relatively easily ported to other
4043 hosts. Argument is core file name (defaults to core.<pid>).
4045 * New command line option
4047 GDB now accepts --pid or -p followed by a process id.
4049 * Change in command line behavior -- corefiles vs. process ids.
4051 There is a subtle behavior in the way in which GDB handles
4052 command line arguments. The first non-flag argument is always
4053 a program to debug, but the second non-flag argument may either
4054 be a corefile or a process id. Previously, GDB would attempt to
4055 open the second argument as a corefile, and if that failed, would
4056 issue a superfluous error message and then attempt to attach it as
4057 a process. Now, if the second argument begins with a non-digit,
4058 it will be treated as a corefile. If it begins with a digit,
4059 GDB will attempt to attach it as a process, and if no such process
4060 is found, will then attempt to open it as a corefile.
4062 * Changes in ARM configurations.
4064 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4065 configuration is fully multi-arch.
4067 * New native configurations
4069 ARM NetBSD arm*-*-netbsd*
4070 x86 OpenBSD i[3456]86-*-openbsd*
4071 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4072 Sparc64 running FreeBSD sparc64-*-freebsd*
4076 Sanyo XStormy16 xstormy16-elf
4078 * OBSOLETE configurations and files
4080 Configurations that have been declared obsolete in this release have
4081 been commented out. Unless there is activity to revive these
4082 configurations, the next release of GDB will have their sources
4083 permanently REMOVED.
4085 AMD 29k family via UDI a29k-amd-udi, udi29k
4086 A29K VxWorks a29k-*-vxworks
4087 AMD 29000 embedded, using EBMON a29k-none-none
4088 AMD 29000 embedded with COFF a29k-none-coff
4089 AMD 29000 embedded with a.out a29k-none-aout
4091 testsuite/gdb.hp/gdb.threads-hp/ directory
4093 * REMOVED configurations and files
4095 TI TMS320C80 tic80-*-*
4097 PowerPC Solaris powerpcle-*-solaris*
4098 PowerPC Windows NT powerpcle-*-cygwin32
4099 PowerPC Netware powerpc-*-netware*
4100 Harris/CXUX m88k m88*-harris-cxux*
4101 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4102 ns32k-utek-sysv* ns32k-utek-*
4103 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4104 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4105 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4106 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4107 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4109 * Changes to command line processing
4111 The new `--args' feature can be used to specify command-line arguments
4112 for the inferior from gdb's command line.
4114 * Changes to key bindings
4116 There is a new `operate-and-get-next' function bound to `C-o'.
4118 *** Changes in GDB 5.1.1
4120 Fix compile problem on DJGPP.
4122 Fix a problem with floating-point registers on the i386 being
4125 Fix to stop GDB crashing on .debug_str debug info.
4127 Numerous documentation fixes.
4129 Numerous testsuite fixes.
4131 *** Changes in GDB 5.1:
4133 * New native configurations
4135 Alpha FreeBSD alpha*-*-freebsd*
4136 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4137 MIPS GNU/Linux mips*-*-linux*
4138 MIPS SGI Irix 6.x mips*-sgi-irix6*
4139 ia64 AIX ia64-*-aix*
4140 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4144 Motorola 68HC11 and 68HC12 m68hc11-elf
4146 UltraSparc running GNU/Linux sparc64-*-linux*
4148 * OBSOLETE configurations and files
4150 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4151 Harris/CXUX m88k m88*-harris-cxux*
4152 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4153 ns32k-utek-sysv* ns32k-utek-*
4154 TI TMS320C80 tic80-*-*
4156 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4157 PowerPC Solaris powerpcle-*-solaris*
4158 PowerPC Windows NT powerpcle-*-cygwin32
4159 PowerPC Netware powerpc-*-netware*
4160 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4161 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4162 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4163 Apple Macintosh (MPW) host N/A
4165 stuff.c (Program to stuff files into a specially prepared space in kdb)
4166 kdb-start.c (Main loop for the standalone kernel debugger)
4168 Configurations that have been declared obsolete in this release have
4169 been commented out. Unless there is activity to revive these
4170 configurations, the next release of GDB will have their sources
4171 permanently REMOVED.
4173 * REMOVED configurations and files
4175 Altos 3068 m68*-altos-*
4176 Convex c1-*-*, c2-*-*
4178 ARM RISCix arm-*-* (as host)
4182 * GDB has been converted to ISO C.
4184 GDB's source code has been converted to ISO C. In particular, the
4185 sources are fully protoized, and rely on standard headers being
4190 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4192 * The MI enabled by default.
4194 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4195 revised and enabled by default. Packages which use GDB as a debugging
4196 engine behind a UI or another front end are encouraged to switch to
4197 using the GDB/MI interface, instead of the old annotations interface
4198 which is now deprecated.
4200 * Support for debugging Pascal programs.
4202 GDB now includes support for debugging Pascal programs. The following
4203 main features are supported:
4205 - Pascal-specific data types such as sets;
4207 - automatic recognition of Pascal sources based on file-name
4210 - Pascal-style display of data types, variables, and functions;
4212 - a Pascal expression parser.
4214 However, some important features are not yet supported.
4216 - Pascal string operations are not supported at all;
4218 - there are some problems with boolean types;
4220 - Pascal type hexadecimal constants are not supported
4221 because they conflict with the internal variables format;
4223 - support for Pascal objects and classes is not full yet;
4225 - unlike Pascal, GDB is case-sensitive for symbol names.
4227 * Changes in completion.
4229 Commands such as `shell', `run' and `set args', which pass arguments
4230 to inferior programs, now complete on file names, similar to what
4231 users expect at the shell prompt.
4233 Commands which accept locations, such as `disassemble', `print',
4234 `breakpoint', `until', etc. now complete on filenames as well as
4235 program symbols. Thus, if you type "break foob TAB", and the source
4236 files linked into the programs include `foobar.c', that file name will
4237 be one of the candidates for completion. However, file names are not
4238 considered for completion after you typed a colon that delimits a file
4239 name from a name of a function in that file, as in "break foo.c:bar".
4241 `set demangle-style' completes on available demangling styles.
4243 * New platform-independent commands:
4245 It is now possible to define a post-hook for a command as well as a
4246 hook that runs before the command. For more details, see the
4247 documentation of `hookpost' in the GDB manual.
4249 * Changes in GNU/Linux native debugging.
4251 Support for debugging multi-threaded programs has been completely
4252 revised for all platforms except m68k and sparc. You can now debug as
4253 many threads as your system allows you to have.
4255 Attach/detach is supported for multi-threaded programs.
4257 Support for SSE registers was added for x86. This doesn't work for
4258 multi-threaded programs though.
4260 * Changes in MIPS configurations.
4262 Multi-arch support is enabled for all MIPS configurations.
4264 GDB can now be built as native debugger on SGI Irix 6.x systems for
4265 debugging n32 executables. (Debugging 64-bit executables is not yet
4268 * Unified support for hardware watchpoints in all x86 configurations.
4270 Most (if not all) native x86 configurations support hardware-assisted
4271 breakpoints and watchpoints in a unified manner. This support
4272 implements debug register sharing between watchpoints, which allows to
4273 put a virtually infinite number of watchpoints on the same address,
4274 and also supports watching regions up to 16 bytes with several debug
4277 The new maintenance command `maintenance show-debug-regs' toggles
4278 debugging print-outs in functions that insert, remove, and test
4279 watchpoints and hardware breakpoints.
4281 * Changes in the DJGPP native configuration.
4283 New command ``info dos sysinfo'' displays assorted information about
4284 the CPU, OS, memory, and DPMI server.
4286 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4287 display information about segment descriptors stored in GDT, LDT, and
4290 New commands ``info dos pde'' and ``info dos pte'' display entries
4291 from Page Directory and Page Tables (for now works with CWSDPMI only).
4292 New command ``info dos address-pte'' displays the Page Table entry for
4293 a given linear address.
4295 GDB can now pass command lines longer than 126 characters to the
4296 program being debugged (requires an update to the libdbg.a library
4297 which is part of the DJGPP development kit).
4299 DWARF2 debug info is now supported.
4301 It is now possible to `step' and `next' through calls to `longjmp'.
4303 * Changes in documentation.
4305 All GDB documentation was converted to GFDL, the GNU Free
4306 Documentation License.
4308 Tracepoints-related commands are now fully documented in the GDB
4311 TUI, the Text-mode User Interface, is now documented in the manual.
4313 Tracepoints-related commands are now fully documented in the GDB
4316 The "GDB Internals" manual now has an index. It also includes
4317 documentation of `ui_out' functions, GDB coding standards, x86
4318 hardware watchpoints, and memory region attributes.
4320 * GDB's version number moved to ``version.in''
4322 The Makefile variable VERSION has been replaced by the file
4323 ``version.in''. People creating GDB distributions should update the
4324 contents of this file.
4328 GUD support is now a standard part of the EMACS distribution.
4330 *** Changes in GDB 5.0:
4332 * Improved support for debugging FP programs on x86 targets
4334 Unified and much-improved support for debugging floating-point
4335 programs on all x86 targets. In particular, ``info float'' now
4336 displays the FP registers in the same format on all x86 targets, with
4337 greater level of detail.
4339 * Improvements and bugfixes in hardware-assisted watchpoints
4341 It is now possible to watch array elements, struct members, and
4342 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4343 on x86 targets no longer erroneously trigger when the address is
4346 * Improvements in the native DJGPP version of GDB
4348 The distribution now includes all the scripts and auxiliary files
4349 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4350 machines ``out of the box''.
4352 The DJGPP version can now debug programs that use signals. It is
4353 possible to catch signals that happened in the debuggee, deliver
4354 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4355 would kill the program being debugged.) Programs that hook hardware
4356 interrupts (keyboard, timer, etc.) can also be debugged.
4358 It is now possible to debug DJGPP programs that redirect their
4359 standard handles or switch them to raw (as opposed to cooked) mode, or
4360 even close them. The command ``run < foo > bar'' works as expected,
4361 and ``info terminal'' reports useful information about the debuggee's
4362 terminal, including raw/cooked mode, redirection, etc.
4364 The DJGPP version now uses termios functions for console I/O, which
4365 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4368 DOS-style file names with drive letters are now fully supported by
4371 It is now possible to debug DJGPP programs that switch their working
4372 directory. It is also possible to rerun the debuggee any number of
4373 times without restarting GDB; thus, you can use the same setup,
4374 breakpoints, etc. for many debugging sessions.
4376 * New native configurations
4378 ARM GNU/Linux arm*-*-linux*
4379 PowerPC GNU/Linux powerpc-*-linux*
4383 Motorola MCore mcore-*-*
4384 x86 VxWorks i[3456]86-*-vxworks*
4385 PowerPC VxWorks powerpc-*-vxworks*
4386 TI TMS320C80 tic80-*-*
4388 * OBSOLETE configurations
4390 Altos 3068 m68*-altos-*
4391 Convex c1-*-*, c2-*-*
4393 ARM RISCix arm-*-* (as host)
4396 Configurations that have been declared obsolete will be commented out,
4397 but the code will be left in place. If there is no activity to revive
4398 these configurations before the next release of GDB, the sources will
4399 be permanently REMOVED.
4401 * Gould support removed
4403 Support for the Gould PowerNode and NP1 has been removed.
4405 * New features for SVR4
4407 On SVR4 native platforms (such as Solaris), if you attach to a process
4408 without first loading a symbol file, GDB will now attempt to locate and
4409 load symbols from the running process's executable file.
4411 * Many C++ enhancements
4413 C++ support has been greatly improved. Overload resolution now works properly
4414 in almost all cases. RTTI support is on the way.
4416 * Remote targets can connect to a sub-program
4418 A popen(3) style serial-device has been added. This device starts a
4419 sub-process (such as a stand-alone simulator) and then communicates
4420 with that. The sub-program to run is specified using the syntax
4421 ``|<program> <args>'' vis:
4423 (gdb) set remotedebug 1
4424 (gdb) target extended-remote |mn10300-elf-sim program-args
4426 * MIPS 64 remote protocol
4428 A long standing bug in the mips64 remote protocol where by GDB
4429 expected certain 32 bit registers (ex SR) to be transfered as 32
4430 instead of 64 bits has been fixed.
4432 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4433 added to provide backward compatibility with older versions of GDB.
4435 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4437 The command ``set remotebinarydownload'' command has been replaced by
4438 ``set remote X-packet''. Other commands in ``set remote'' family
4439 include ``set remote P-packet''.
4441 * Breakpoint commands accept ranges.
4443 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4444 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4445 ``tracepoint passcount'' also accepts a range of tracepoints.
4447 * ``apropos'' command added.
4449 The ``apropos'' command searches through command names and
4450 documentation strings, printing out matches, making it much easier to
4451 try to find a command that does what you are looking for.
4455 A new machine oriented interface (MI) has been added to GDB. This
4456 interface is designed for debug environments running GDB as a separate
4457 process. This is part of the long term libGDB project. See the
4458 "GDB/MI" chapter of the GDB manual for further information. It can be
4459 enabled by configuring with:
4461 .../configure --enable-gdbmi
4463 *** Changes in GDB-4.18:
4465 * New native configurations
4467 HP-UX 10.20 hppa*-*-hpux10.20
4468 HP-UX 11.x hppa*-*-hpux11.0*
4469 M68K GNU/Linux m68*-*-linux*
4473 Fujitsu FR30 fr30-*-elf*
4474 Intel StrongARM strongarm-*-*
4475 Mitsubishi D30V d30v-*-*
4477 * OBSOLETE configurations
4479 Gould PowerNode, NP1 np1-*-*, pn-*-*
4481 Configurations that have been declared obsolete will be commented out,
4482 but the code will be left in place. If there is no activity to revive
4483 these configurations before the next release of GDB, the sources will
4484 be permanently REMOVED.
4488 As a compatibility experiment, GDB's source files buildsym.h and
4489 buildsym.c have been converted to pure standard C, no longer
4490 containing any K&R compatibility code. We believe that all systems in
4491 use today either come with a standard C compiler, or have a GCC port
4492 available. If this is not true, please report the affected
4493 configuration to bug-gdb@gnu.org immediately. See the README file for
4494 information about getting a standard C compiler if you don't have one
4499 GDB now uses readline 2.2.
4501 * set extension-language
4503 You can now control the mapping between filename extensions and source
4504 languages by using the `set extension-language' command. For instance,
4505 you can ask GDB to treat .c files as C++ by saying
4506 set extension-language .c c++
4507 The command `info extensions' lists all of the recognized extensions
4508 and their associated languages.
4510 * Setting processor type for PowerPC and RS/6000
4512 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4513 you can use the `set processor' command to specify what variant of the
4514 PowerPC family you are debugging. The command
4518 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4519 following PowerPC and RS6000 variants:
4521 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4522 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4524 403GC IBM PowerPC 403GC
4525 505 Motorola PowerPC 505
4526 860 Motorola PowerPC 860 or 850
4527 601 Motorola PowerPC 601
4528 602 Motorola PowerPC 602
4529 603 Motorola/IBM PowerPC 603 or 603e
4530 604 Motorola PowerPC 604 or 604e
4531 750 Motorola/IBM PowerPC 750 or 750
4533 At the moment, this command just tells GDB what to name the
4534 special-purpose processor registers. Since almost all the affected
4535 registers are inaccessible to user-level programs, this command is
4536 only useful for remote debugging in its present form.
4540 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4541 more extensive support for HP-UX. Added features include shared
4542 library support, kernel threads and hardware watchpoints for 11.00,
4543 support for HP's ANSI C and C++ compilers, and a compatibility mode
4544 for xdb and dbx commands.
4548 HP's donation includes the new concept of catchpoints, which is a
4549 generalization of the old catch command. On HP-UX, it is now possible
4550 to catch exec, fork, and vfork, as well as library loading.
4552 This means that the existing catch command has changed; its first
4553 argument now specifies the type of catch to be set up. See the
4554 output of "help catch" for a list of catchpoint types.
4556 * Debugging across forks
4558 On HP-UX, you can choose which process to debug when a fork() happens
4563 HP has donated a curses-based terminal user interface (TUI). To get
4564 it, build with --enable-tui. Although this can be enabled for any
4565 configuration, at present it only works for native HP debugging.
4567 * GDB remote protocol additions
4569 A new protocol packet 'X' that writes binary data is now available.
4570 Default behavior is to try 'X', then drop back to 'M' if the stub
4571 fails to respond. The settable variable `remotebinarydownload'
4572 allows explicit control over the use of 'X'.
4574 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4575 full 64-bit address. The command
4577 set remoteaddresssize 32
4579 can be used to revert to the old behaviour. For existing remote stubs
4580 the change should not be noticed, as the additional address information
4583 In order to assist in debugging stubs, you may use the maintenance
4584 command `packet' to send any text string to the stub. For instance,
4586 maint packet heythere
4588 sends the packet "$heythere#<checksum>". Note that it is very easy to
4589 disrupt a debugging session by sending the wrong packet at the wrong
4592 The compare-sections command allows you to compare section data on the
4593 target to what is in the executable file without uploading or
4594 downloading, by comparing CRC checksums.
4596 * Tracing can collect general expressions
4598 You may now collect general expressions at tracepoints. This requires
4599 further additions to the target-side stub; see tracepoint.c and
4600 doc/agentexpr.texi for further details.
4602 * mask-address variable for Mips
4604 For Mips targets, you may control the zeroing of the upper 32 bits of
4605 a 64-bit address by entering `set mask-address on'. This is mainly
4606 of interest to users of embedded R4xxx and R5xxx processors.
4608 * Higher serial baud rates
4610 GDB's serial code now allows you to specify baud rates 57600, 115200,
4611 230400, and 460800 baud. (Note that your host system may not be able
4612 to achieve all of these rates.)
4616 The i960 configuration now includes an initial implementation of a
4617 builtin simulator, contributed by Jim Wilson.
4620 *** Changes in GDB-4.17:
4622 * New native configurations
4624 Alpha GNU/Linux alpha*-*-linux*
4625 Unixware 2.x i[3456]86-unixware2*
4626 Irix 6.x mips*-sgi-irix6*
4627 PowerPC GNU/Linux powerpc-*-linux*
4628 PowerPC Solaris powerpcle-*-solaris*
4629 Sparc GNU/Linux sparc-*-linux*
4630 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4634 Argonaut Risc Chip (ARC) arc-*-*
4635 Hitachi H8/300S h8300*-*-*
4636 Matsushita MN10200 w/simulator mn10200-*-*
4637 Matsushita MN10300 w/simulator mn10300-*-*
4638 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4639 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4640 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4641 Mitsubishi D10V w/simulator d10v-*-*
4642 Mitsubishi M32R/D w/simulator m32r-*-elf*
4643 Tsqware Sparclet sparclet-*-*
4644 NEC V850 w/simulator v850-*-*
4646 * New debugging protocols
4648 ARM with RDI protocol arm*-*-*
4649 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4650 DDB and LSI variants of PMON protocol mips*-*-*
4651 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4652 PowerPC with SDS protocol powerpc{,le}-*-eabi
4653 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4657 All configurations can now understand and use the DWARF 2 debugging
4658 format. The choice is automatic, if the symbol file contains DWARF 2
4663 GDB now includes basic Java language support. This support is
4664 only useful with Java compilers that produce native machine code.
4666 * solib-absolute-prefix and solib-search-path
4668 For SunOS and SVR4 shared libraries, you may now set the prefix for
4669 loading absolute shared library symbol files, and the search path for
4670 locating non-absolute shared library symbol files.
4672 * Live range splitting
4674 GDB can now effectively debug code for which GCC has performed live
4675 range splitting as part of its optimization. See gdb/doc/LRS for
4676 more details on the expected format of the stabs information.
4680 GDB's support for the GNU Hurd, including thread debugging, has been
4681 updated to work with current versions of the Hurd.
4685 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4686 instruction set. ARM GDB automatically detects when Thumb
4687 instructions are in use, and adjusts disassembly and backtracing
4692 GDB's MIPS target configurations now handle the MIP16 16-bit
4697 GDB now includes support for overlays; if an executable has been
4698 linked such that multiple sections are based at the same address, GDB
4699 will decide which section to use for symbolic info. You can choose to
4700 control the decision manually, using overlay commands, or implement
4701 additional target-side support and use "overlay load-target" to bring
4702 in the overlay mapping. Do "help overlay" for more detail.
4706 The command "info symbol <address>" displays information about
4707 the symbol at the specified address.
4711 The standard remote protocol now includes an extension that allows
4712 asynchronous collection and display of trace data. This requires
4713 extensive support in the target-side debugging stub. Tracing mode
4714 includes a new interaction mode in GDB and new commands: see the
4715 file tracepoint.c for more details.
4719 Configurations for embedded MIPS now include a simulator contributed
4720 by Cygnus Solutions. The simulator supports the instruction sets
4721 of most MIPS variants.
4725 Sparc configurations may now include the ERC32 simulator contributed
4726 by the European Space Agency. The simulator is not built into
4727 Sparc targets by default; configure with --enable-sim to include it.
4731 For target configurations that may include multiple variants of a
4732 basic architecture (such as MIPS and SH), you may now set the
4733 architecture explicitly. "set arch" sets, "info arch" lists
4734 the possible architectures.
4736 *** Changes in GDB-4.16:
4738 * New native configurations
4740 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4741 M68K NetBSD m68k-*-netbsd*
4742 PowerPC AIX 4.x powerpc-*-aix*
4743 PowerPC MacOS powerpc-*-macos*
4744 PowerPC Windows NT powerpcle-*-cygwin32
4745 RS/6000 AIX 4.x rs6000-*-aix4*
4749 ARM with RDP protocol arm-*-*
4750 I960 with MON960 i960-*-coff
4751 MIPS VxWorks mips*-*-vxworks*
4752 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4753 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4755 Matra Sparclet sparclet-*-*
4759 The powerpc-eabi configuration now includes the PSIM simulator,
4760 contributed by Andrew Cagney, with assistance from Mike Meissner.
4761 PSIM is a very elaborate model of the PowerPC, including not only
4762 basic instruction set execution, but also details of execution unit
4763 performance and I/O hardware. See sim/ppc/README for more details.
4767 GDB now works with Solaris 2.5.
4769 * Windows 95/NT native
4771 GDB will now work as a native debugger on Windows 95 and Windows NT.
4772 To build it from source, you must use the "gnu-win32" environment,
4773 which uses a DLL to emulate enough of Unix to run the GNU tools.
4774 Further information, binaries, and sources are available at
4775 ftp.cygnus.com, under pub/gnu-win32.
4777 * dont-repeat command
4779 If a user-defined command includes the command `dont-repeat', then the
4780 command will not be repeated if the user just types return. This is
4781 useful if the command is time-consuming to run, so that accidental
4782 extra keystrokes don't run the same command many times.
4784 * Send break instead of ^C
4786 The standard remote protocol now includes an option to send a break
4787 rather than a ^C to the target in order to interrupt it. By default,
4788 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4790 * Remote protocol timeout
4792 The standard remote protocol includes a new variable `remotetimeout'
4793 that allows you to set the number of seconds before GDB gives up trying
4794 to read from the target. The default value is 2.
4796 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4798 By default GDB will automatically keep track of objects as they are
4799 loaded and unloaded by the dynamic linker. By using the command `set
4800 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4801 when shared library events occur, thus allowing you to set breakpoints
4802 in shared libraries which are explicitly loaded by the inferior.
4804 Note this feature does not work on hpux8. On hpux9 you must link
4805 /usr/lib/end.o into your program. This feature should work
4806 automatically on hpux10.
4808 * Irix 5.x hardware watchpoint support
4810 Irix 5 configurations now support the use of hardware watchpoints.
4812 * Mips protocol "SYN garbage limit"
4814 When debugging a Mips target using the `target mips' protocol, you
4815 may set the number of characters that GDB will ignore by setting
4816 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4817 every character. The default value is 1050.
4819 * Recording and replaying remote debug sessions
4821 If you set `remotelogfile' to the name of a file, gdb will write to it
4822 a recording of a remote debug session. This recording may then be
4823 replayed back to gdb using "gdbreplay". See gdbserver/README for
4824 details. This is useful when you have a problem with GDB while doing
4825 remote debugging; you can make a recording of the session and send it
4826 to someone else, who can then recreate the problem.
4828 * Speedups for remote debugging
4830 GDB includes speedups for downloading and stepping MIPS systems using
4831 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4832 and more efficient S-record downloading.
4834 * Memory use reductions and statistics collection
4836 GDB now uses less memory and reports statistics about memory usage.
4837 Try the `maint print statistics' command, for example.
4839 *** Changes in GDB-4.15:
4841 * Psymtabs for XCOFF
4843 The symbol reader for AIX GDB now uses partial symbol tables. This
4844 can greatly improve startup time, especially for large executables.
4846 * Remote targets use caching
4848 Remote targets now use a data cache to speed up communication with the
4849 remote side. The data cache could lead to incorrect results because
4850 it doesn't know about volatile variables, thus making it impossible to
4851 debug targets which use memory mapped I/O devices. `set remotecache
4852 off' turns the the data cache off.
4854 * Remote targets may have threads
4856 The standard remote protocol now includes support for multiple threads
4857 in the target system, using new protocol commands 'H' and 'T'. See
4858 gdb/remote.c for details.
4862 If GDB is configured with `--enable-netrom', then it will include
4863 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4864 acts as though it is a bank of ROM on the target board, but you can
4865 write into it over the network. GDB's support consists only of
4866 support for fast loading into the emulated ROM; to debug, you must use
4867 another protocol, such as standard remote protocol. The usual
4868 sequence is something like
4870 target nrom <netrom-hostname>
4872 target remote <netrom-hostname>:1235
4876 GDB now includes support for the Apple Macintosh, as a host only. It
4877 may be run as either an MPW tool or as a standalone application, and
4878 it can debug through the serial port. All the usual GDB commands are
4879 available, but to the target command, you must supply "serial" as the
4880 device type instead of "/dev/ttyXX". See mpw-README in the main
4881 directory for more information on how to build. The MPW configuration
4882 scripts */mpw-config.in support only a few targets, and only the
4883 mips-idt-ecoff target has been tested.
4887 GDB configuration now uses autoconf. This is not user-visible,
4888 but does simplify configuration and building.
4892 GDB now supports hpux10.
4894 *** Changes in GDB-4.14:
4896 * New native configurations
4898 x86 FreeBSD i[345]86-*-freebsd
4899 x86 NetBSD i[345]86-*-netbsd
4900 NS32k NetBSD ns32k-*-netbsd
4901 Sparc NetBSD sparc-*-netbsd
4905 A29K VxWorks a29k-*-vxworks
4906 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4907 CPU32 EST-300 emulator m68*-*-est*
4908 PowerPC ELF powerpc-*-elf
4911 * Alpha OSF/1 support for procfs
4913 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4914 possible to attach to running processes. As the mounting of the /proc
4915 filesystem is optional on the Alpha, GDB automatically determines
4916 the availability of /proc during startup. This can lead to problems
4917 if /proc is unmounted after GDB has been started.
4919 * Arguments to user-defined commands
4921 User commands may accept up to 10 arguments separated by whitespace.
4922 Arguments are accessed within the user command via $arg0..$arg9. A
4925 print $arg0 + $arg1 + $arg2
4927 To execute the command use:
4930 Defines the command "adder" which prints the sum of its three arguments.
4931 Note the arguments are text substitutions, so they may reference variables,
4932 use complex expressions, or even perform inferior function calls.
4934 * New `if' and `while' commands
4936 This makes it possible to write more sophisticated user-defined
4937 commands. Both commands take a single argument, which is the
4938 expression to evaluate, and must be followed by the commands to
4939 execute, one per line, if the expression is nonzero, the list being
4940 terminated by the word `end'. The `if' command list may include an
4941 `else' word, which causes the following commands to be executed only
4942 if the expression is zero.
4944 * Fortran source language mode
4946 GDB now includes partial support for Fortran 77. It will recognize
4947 Fortran programs and can evaluate a subset of Fortran expressions, but
4948 variables and functions may not be handled correctly. GDB will work
4949 with G77, but does not yet know much about symbols emitted by other
4952 * Better HPUX support
4954 Most debugging facilities now work on dynamic executables for HPPAs
4955 running hpux9 or later. You can attach to running dynamically linked
4956 processes, but by default the dynamic libraries will be read-only, so
4957 for instance you won't be able to put breakpoints in them. To change
4958 that behavior do the following before running the program:
4964 This will cause the libraries to be mapped private and read-write.
4965 To revert to the normal behavior, do this:
4971 You cannot set breakpoints or examine data in the library until after
4972 the library is loaded if the function/data symbols do not have
4975 GDB can now also read debug symbols produced by the HP C compiler on
4976 HPPAs (sorry, no C++, Fortran or 68k support).
4978 * Target byte order now dynamically selectable
4980 You can choose which byte order to use with a target system, via the
4981 commands "set endian big" and "set endian little", and you can see the
4982 current setting by using "show endian". You can also give the command
4983 "set endian auto", in which case GDB will use the byte order
4984 associated with the executable. Currently, only embedded MIPS
4985 configurations support dynamic selection of target byte order.
4987 * New DOS host serial code
4989 This version uses DPMI interrupts to handle buffered I/O, so you
4990 no longer need to run asynctsr when debugging boards connected to
4993 *** Changes in GDB-4.13:
4995 * New "complete" command
4997 This lists all the possible completions for the rest of the line, if it
4998 were to be given as a command itself. This is intended for use by emacs.
5000 * Trailing space optional in prompt
5002 "set prompt" no longer adds a space for you after the prompt you set. This
5003 allows you to set a prompt which ends in a space or one that does not.
5005 * Breakpoint hit counts
5007 "info break" now displays a count of the number of times the breakpoint
5008 has been hit. This is especially useful in conjunction with "ignore"; you
5009 can ignore a large number of breakpoint hits, look at the breakpoint info
5010 to see how many times the breakpoint was hit, then run again, ignoring one
5011 less than that number, and this will get you quickly to the last hit of
5014 * Ability to stop printing at NULL character
5016 "set print null-stop" will cause GDB to stop printing the characters of
5017 an array when the first NULL is encountered. This is useful when large
5018 arrays actually contain only short strings.
5020 * Shared library breakpoints
5022 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5023 breakpoints in shared libraries before the executable is run.
5025 * Hardware watchpoints
5027 There is a new hardware breakpoint for the watch command for sparclite
5028 targets. See gdb/sparclite/hw_breakpoint.note.
5030 Hardware watchpoints are also now supported under GNU/Linux.
5034 Annotations have been added. These are for use with graphical interfaces,
5035 and are still experimental. Currently only gdba.el uses these.
5037 * Improved Irix 5 support
5039 GDB now works properly with Irix 5.2.
5041 * Improved HPPA support
5043 GDB now works properly with the latest GCC and GAS.
5045 * New native configurations
5047 Sequent PTX4 i[34]86-sequent-ptx4
5048 HPPA running OSF/1 hppa*-*-osf*
5049 Atari TT running SVR4 m68*-*-sysv4*
5050 RS/6000 LynxOS rs6000-*-lynxos*
5054 OS/9000 i[34]86-*-os9k
5055 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5058 * Hitachi SH7000 and E7000-PC ICE support
5060 There is now support for communicating with the Hitachi E7000-PC ICE.
5061 This is available automatically when GDB is configured for the SH.
5065 As usual, a variety of small fixes and improvements, both generic
5066 and configuration-specific. See the ChangeLog for more detail.
5068 *** Changes in GDB-4.12:
5070 * Irix 5 is now supported
5074 GDB-4.12 on the HPPA has a number of changes which make it unable
5075 to debug the output from the currently released versions of GCC and
5076 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5077 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5078 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5081 *** Changes in GDB-4.11:
5083 * User visible changes:
5087 The "set remotedebug" option is now consistent between the mips remote
5088 target, remote targets using the gdb-specific protocol, UDI (AMD's
5089 debug protocol for the 29k) and the 88k bug monitor. It is now an
5090 integer specifying a debug level (normally 0 or 1, but 2 means more
5091 debugging info for the mips target).
5093 * DEC Alpha native support
5095 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5096 debug info, but GDB works fairly well with the DEC compiler and should
5097 work with a future GCC release. See the README file for a few
5098 Alpha-specific notes.
5100 * Preliminary thread implementation
5102 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5104 * LynxOS native and target support for 386
5106 This release has been hosted on LynxOS 2.2, and also can be configured
5107 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5110 * Improvements in C++ mangling/demangling.
5112 This release has much better g++ debugging, specifically in name
5113 mangling/demangling, virtual function calls, print virtual table,
5114 call methods, ...etc.
5116 *** Changes in GDB-4.10:
5118 * User visible changes:
5120 Remote debugging using the GDB-specific (`target remote') protocol now
5121 supports the `load' command. This is only useful if you have some
5122 other way of getting the stub to the target system, and you can put it
5123 somewhere in memory where it won't get clobbered by the download.
5125 Filename completion now works.
5127 When run under emacs mode, the "info line" command now causes the
5128 arrow to point to the line specified. Also, "info line" prints
5129 addresses in symbolic form (as well as hex).
5131 All vxworks based targets now support a user settable option, called
5132 vxworks-timeout. This option represents the number of seconds gdb
5133 should wait for responses to rpc's. You might want to use this if
5134 your vxworks target is, perhaps, a slow software simulator or happens
5135 to be on the far side of a thin network line.
5139 This release contains support for using a DEC alpha as a GDB host for
5140 cross debugging. Native alpha debugging is not supported yet.
5143 *** Changes in GDB-4.9:
5147 This is the first GDB release which is accompanied by a matching testsuite.
5148 The testsuite requires installation of dejagnu, which should be available
5149 via ftp from most sites that carry GNU software.
5153 'Cfront' style demangling has had its name changed to 'ARM' style, to
5154 emphasize that it was written from the specifications in the C++ Annotated
5155 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5156 disclaimers, it still generated too much confusion with users attempting to
5157 use gdb with AT&T cfront.
5161 GDB now uses a standard remote interface to a simulator library.
5162 So far, the library contains simulators for the Zilog Z8001/2, the
5163 Hitachi H8/300, H8/500 and Super-H.
5165 * New targets supported
5167 H8/300 simulator h8300-hitachi-hms or h8300hms
5168 H8/500 simulator h8500-hitachi-hms or h8500hms
5169 SH simulator sh-hitachi-hms or sh
5170 Z8000 simulator z8k-zilog-none or z8ksim
5171 IDT MIPS board over serial line mips-idt-ecoff
5173 Cross-debugging to GO32 targets is supported. It requires a custom
5174 version of the i386-stub.c module which is integrated with the
5175 GO32 memory extender.
5177 * New remote protocols
5179 MIPS remote debugging protocol.
5181 * New source languages supported
5183 This version includes preliminary support for Chill, a Pascal like language
5184 used by telecommunications companies. Chill support is also being integrated
5185 into the GNU compiler, but we don't know when it will be publically available.
5188 *** Changes in GDB-4.8:
5190 * HP Precision Architecture supported
5192 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5193 version of this support was available as a set of patches from the
5194 University of Utah. GDB does not support debugging of programs
5195 compiled with the HP compiler, because HP will not document their file
5196 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5197 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5199 Many problems in the preliminary version have been fixed.
5201 * Faster and better demangling
5203 We have improved template demangling and fixed numerous bugs in the GNU style
5204 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5205 character types (wchar_t) are now supported. Demangling of each symbol is now
5206 only done once, and is cached when the symbol table for a file is read in.
5207 This results in a small increase in memory usage for C programs, a moderate
5208 increase in memory usage for C++ programs, and a fantastic speedup in
5211 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5212 from the specifications in the Annotated Reference Manual, which AT&T's
5213 compiler does not actually implement.
5215 * G++ multiple inheritance compiler problem
5217 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5218 inheritance lattices was reworked to properly discover ambiguities. We
5219 recently found an example which causes this new algorithm to fail in a
5220 very subtle way, producing bad debug information for those classes.
5221 The file 'gcc.patch' (in this directory) can be applied to gcc to
5222 circumvent the problem. A future GCC release will contain a complete
5225 The previous G++ debug info problem (mentioned below for the gdb-4.7
5226 release) is fixed in gcc version 2.3.2.
5228 * Improved configure script
5230 The `configure' script will now attempt to guess your system type if
5231 you don't supply a host system type. The old scheme of supplying a
5232 host system triplet is preferable over using this. All the magic is
5233 done in the new `config.guess' script. Examine it for details.
5235 We have also brought our configure script much more in line with the FSF's
5236 version. It now supports the --with-xxx options. In particular,
5237 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5238 The resulting GDB will not be able to read arbitrary object file formats --
5239 only the format ``expected'' to be used on the configured target system.
5240 We hope to make this the default in a future release.
5242 * Documentation improvements
5244 There's new internal documentation on how to modify GDB, and how to
5245 produce clean changes to the code. We implore people to read it
5246 before submitting changes.
5248 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5249 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5250 `info' files are also provided. To build `info' files from scratch,
5251 you will need the latest `makeinfo' release, which will be available in
5252 a future texinfo-X.Y release.
5254 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5255 We're not sure exactly which versions have this problem, but it has
5256 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5257 or better. If that isn't possible, there is a patch in
5258 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5259 around this problem.
5263 GDB now supports array constants that can be used in expressions typed in by
5264 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5265 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5268 The new directory `gdb/sparclite' contains a program that demonstrates
5269 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5271 * New native hosts supported
5273 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5274 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5276 * New targets supported
5278 AMD 29k family via UDI a29k-amd-udi or udi29k
5280 * New file formats supported
5282 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5283 HPUX core files, and SCO 3.2v2 core files.
5287 Attaching to processes now works again; thanks for the many bug reports.
5289 We have also stomped on a bunch of core dumps caused by
5290 printf_filtered("%s") problems.
5292 We eliminated a copyright problem on the rpc and ptrace header files
5293 for VxWorks, which was discovered at the last minute during the 4.7
5294 release. You should now be able to build a VxWorks GDB.
5296 You can now interrupt gdb while an attached process is running. This
5297 will cause the attached process to stop, and give control back to GDB.
5299 We fixed problems caused by using too many file descriptors
5300 for reading symbols from object files and libraries. This was
5301 especially a problem for programs that used many (~100) shared
5304 The `step' command now only enters a subroutine if there is line number
5305 information for the subroutine. Otherwise it acts like the `next'
5306 command. Previously, `step' would enter subroutines if there was
5307 any debugging information about the routine. This avoids problems
5308 when using `cc -g1' on MIPS machines.
5310 * Internal improvements
5312 GDB's internal interfaces have been improved to make it easier to support
5313 debugging of multiple languages in the future.
5315 GDB now uses a common structure for symbol information internally.
5316 Minimal symbols (derived from linkage symbols in object files), partial
5317 symbols (from a quick scan of debug information), and full symbols
5318 contain a common subset of information, making it easier to write
5319 shared code that handles any of them.
5321 * New command line options
5323 We now accept --silent as an alias for --quiet.
5327 The memory-mapped-malloc library is now licensed under the GNU Library
5328 General Public License.
5330 *** Changes in GDB-4.7:
5332 * Host/native/target split
5334 GDB has had some major internal surgery to untangle the support for
5335 hosts and remote targets. Now, when you configure GDB for a remote
5336 target, it will no longer load in all of the support for debugging
5337 local programs on the host. When fully completed and tested, this will
5338 ensure that arbitrary host/target combinations are possible.
5340 The primary conceptual shift is to separate the non-portable code in
5341 GDB into three categories. Host specific code is required any time GDB
5342 is compiled on that host, regardless of the target. Target specific
5343 code relates to the peculiarities of the target, but can be compiled on
5344 any host. Native specific code is everything else: it can only be
5345 built when the host and target are the same system. Child process
5346 handling and core file support are two common `native' examples.
5348 GDB's use of /proc for controlling Unix child processes is now cleaner.
5349 It has been split out into a single module under the `target_ops' vector,
5350 plus two native-dependent functions for each system that uses /proc.
5352 * New hosts supported
5354 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5355 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5356 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5358 * New targets supported
5360 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5361 68030 and CPU32 m68030-*-*, m68332-*-*
5363 * New native hosts supported
5365 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5366 (386bsd is not well tested yet)
5367 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5369 * New file formats supported
5371 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5372 supports reading of `a.out.adobe' object files, which are an a.out
5373 format extended with minimal information about multiple sections.
5377 `show copying' is the same as the old `info copying'.
5378 `show warranty' is the same as `info warrantee'.
5379 These were renamed for consistency. The old commands continue to work.
5381 `info handle' is a new alias for `info signals'.
5383 You can now define pre-command hooks, which attach arbitrary command
5384 scripts to any command. The commands in the hook will be executed
5385 prior to the user's command. You can also create a hook which will be
5386 executed whenever the program stops. See gdb.texinfo.
5390 We now deal with Cfront style name mangling, and can even extract type
5391 info from mangled symbols. GDB can automatically figure out which
5392 symbol mangling style your C++ compiler uses.
5394 Calling of methods and virtual functions has been improved as well.
5398 The crash that occured when debugging Sun Ansi-C compiled binaries is
5399 fixed. This was due to mishandling of the extra N_SO stabs output
5402 We also finally got Ultrix 4.2 running in house, and fixed core file
5403 support, with help from a dozen people on the net.
5405 John M. Farrell discovered that the reason that single-stepping was so
5406 slow on all of the Mips based platforms (primarily SGI and DEC) was
5407 that we were trying to demangle and lookup a symbol used for internal
5408 purposes on every instruction that was being stepped through. Changing
5409 the name of that symbol so that it couldn't be mistaken for a C++
5410 mangled symbol sped things up a great deal.
5412 Rich Pixley sped up symbol lookups in general by getting much smarter
5413 about when C++ symbol mangling is necessary. This should make symbol
5414 completion (TAB on the command line) much faster. It's not as fast as
5415 we'd like, but it's significantly faster than gdb-4.6.
5419 A new user controllable variable 'call_scratch_address' can
5420 specify the location of a scratch area to be used when GDB
5421 calls a function in the target. This is necessary because the
5422 usual method of putting the scratch area on the stack does not work
5423 in systems that have separate instruction and data spaces.
5425 We integrated changes to support the 29k UDI (Universal Debugger
5426 Interface), but discovered at the last minute that we didn't have all
5427 of the appropriate copyright paperwork. We are working with AMD to
5428 resolve this, and hope to have it available soon.
5432 We have sped up the remote serial line protocol, especially for targets
5433 with lots of registers. It now supports a new `expedited status' ('T')
5434 message which can be used in place of the existing 'S' status message.
5435 This allows the remote stub to send only the registers that GDB
5436 needs to make a quick decision about single-stepping or conditional
5437 breakpoints, eliminating the need to fetch the entire register set for
5438 each instruction being stepped through.
5440 The GDB remote serial protocol now implements a write-through cache for
5441 registers, only re-reading the registers if the target has run.
5443 There is also a new remote serial stub for SPARC processors. You can
5444 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5445 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5446 processor with a serial port.
5450 Configure.in files have become much easier to read and modify. A new
5451 `table driven' format makes it more obvious what configurations are
5452 supported, and what files each one uses.
5456 There is a new opcodes library which will eventually contain all of the
5457 disassembly routines and opcode tables. At present, it only contains
5458 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5459 disassembler (binutils/objdump) to share these routines.
5461 The libiberty library is now copylefted under the GNU Library General
5462 Public License. This allows more liberal use, and was done so libg++
5463 can use it. This makes no difference to GDB, since the Library License
5464 grants all the rights from the General Public License.
5468 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5469 reference to the stabs symbol info used by the debugger. It is (as far
5470 as we know) the only published document on this fascinating topic. We
5471 encourage you to read it, compare it to the stabs information on your
5472 system, and send improvements on the document in general (to
5473 bug-gdb@prep.ai.mit.edu).
5475 And, of course, many bugs have been fixed.
5478 *** Changes in GDB-4.6:
5480 * Better support for C++ function names
5482 GDB now accepts as input the "demangled form" of C++ overloaded function
5483 names and member function names, and can do command completion on such names
5484 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5485 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5486 Make use of command completion, it is your friend.
5488 GDB also now accepts a variety of C++ mangled symbol formats. They are
5489 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5490 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5491 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5492 for the list of formats.
5494 * G++ symbol mangling problem
5496 Recent versions of gcc have a bug in how they emit debugging information for
5497 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5498 directory) can be applied to gcc to fix the problem. Alternatively, if you
5499 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5500 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5501 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5504 * New 'maintenance' command
5506 All of the commands related to hacking GDB internals have been moved out of
5507 the main command set, and now live behind the 'maintenance' command. This
5508 can also be abbreviated as 'mt'. The following changes were made:
5510 dump-me -> maintenance dump-me
5511 info all-breakpoints -> maintenance info breakpoints
5512 printmsyms -> maintenance print msyms
5513 printobjfiles -> maintenance print objfiles
5514 printpsyms -> maintenance print psymbols
5515 printsyms -> maintenance print symbols
5517 The following commands are new:
5519 maintenance demangle Call internal GDB demangler routine to
5520 demangle a C++ link name and prints the result.
5521 maintenance print type Print a type chain for a given symbol
5523 * Change to .gdbinit file processing
5525 We now read the $HOME/.gdbinit file before processing the argv arguments
5526 (e.g. reading symbol files or core files). This allows global parameters to
5527 be set, which will apply during the symbol reading. The ./.gdbinit is still
5528 read after argv processing.
5530 * New hosts supported
5532 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5534 GNU/Linux support i386-unknown-linux or linux
5536 We are also including code to support the HP/PA running BSD and HPUX. This
5537 is almost guaranteed not to work, as we didn't have time to test or build it
5538 for this release. We are including it so that the more adventurous (or
5539 masochistic) of you can play with it. We also had major problems with the
5540 fact that the compiler that we got from HP doesn't support the -g option.
5543 * New targets supported
5545 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5547 * More smarts about finding #include files
5549 GDB now remembers the compilation directory for all include files, and for
5550 all files from which C is generated (like yacc and lex sources). This
5551 greatly improves GDB's ability to find yacc/lex sources, and include files,
5552 especially if you are debugging your program from a directory different from
5553 the one that contains your sources.
5555 We also fixed a bug which caused difficulty with listing and setting
5556 breakpoints in include files which contain C code. (In the past, you had to
5557 try twice in order to list an include file that you hadn't looked at before.)
5559 * Interesting infernals change
5561 GDB now deals with arbitrary numbers of sections, where the symbols for each
5562 section must be relocated relative to that section's landing place in the
5563 target's address space. This work was needed to support ELF with embedded
5564 stabs used by Solaris-2.0.
5566 * Bug fixes (of course!)
5568 There have been loads of fixes for the following things:
5569 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5570 i960, stabs, DOS(GO32), procfs, etc...
5572 See the ChangeLog for details.
5574 *** Changes in GDB-4.5:
5576 * New machines supported (host and target)
5578 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5580 SGI Irix-4.x mips-sgi-irix4 or iris4
5582 * New malloc package
5584 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5585 Mmalloc is capable of handling mutiple heaps of memory. It is also
5586 capable of saving a heap to a file, and then mapping it back in later.
5587 This can be used to greatly speedup the startup of GDB by using a
5588 pre-parsed symbol table which lives in a mmalloc managed heap. For
5589 more details, please read mmalloc/mmalloc.texi.
5593 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5594 'help info proc' for details.
5596 * MIPS ecoff symbol table format
5598 The code that reads MIPS symbol table format is now supported on all hosts.
5599 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5602 * File name changes for MS-DOS
5604 Many files in the config directories have been renamed to make it easier to
5605 support GDB on MS-DOSe systems (which have very restrictive file name
5606 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5607 environment) is close to working but has some remaining problems. Note
5608 that debugging of DOS programs is not supported, due to limitations
5609 in the ``operating system'', but it can be used to host cross-debugging.
5611 * Cross byte order fixes
5613 Many fixes have been made to support cross debugging of Sparc and MIPS
5614 targets from hosts whose byte order differs.
5616 * New -mapped and -readnow options
5618 If memory-mapped files are available on your system through the 'mmap'
5619 system call, you can use the -mapped option on the `file' or
5620 `symbol-file' commands to cause GDB to write the symbols from your
5621 program into a reusable file. If the program you are debugging is
5622 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5623 Future GDB debugging sessions will notice the presence of this file,
5624 and will quickly map in symbol information from it, rather than reading
5625 the symbol table from the executable program. Using the '-mapped'
5626 option in a GDB `file' or `symbol-file' command has the same effect as
5627 starting GDB with the '-mapped' command-line option.
5629 You can cause GDB to read the entire symbol table immediately by using
5630 the '-readnow' option with any of the commands that load symbol table
5631 information (or on the GDB command line). This makes the command
5632 slower, but makes future operations faster.
5634 The -mapped and -readnow options are typically combined in order to
5635 build a `fred.syms' file that contains complete symbol information.
5636 A simple GDB invocation to do nothing but build a `.syms' file for future
5639 gdb -batch -nx -mapped -readnow programname
5641 The `.syms' file is specific to the host machine on which GDB is run.
5642 It holds an exact image of GDB's internal symbol table. It cannot be
5643 shared across multiple host platforms.
5645 * longjmp() handling
5647 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5648 siglongjmp() without losing control. This feature has not yet been ported to
5649 all systems. It currently works on many 386 platforms, all MIPS-based
5650 platforms (SGI, DECstation, etc), and Sun3/4.
5654 Preliminary work has been put in to support the new Solaris OS from Sun. At
5655 this time, it can control and debug processes, but it is not capable of
5660 As always, many many bug fixes. The major areas were with g++, and mipsread.
5661 People using the MIPS-based platforms should experience fewer mysterious
5662 crashes and trashed symbol tables.
5664 *** Changes in GDB-4.4:
5666 * New machines supported (host and target)
5668 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5670 BSD Reno on Vax vax-dec-bsd
5671 Ultrix on Vax vax-dec-ultrix
5673 * New machines supported (target)
5675 AMD 29000 embedded, using EBMON a29k-none-none
5679 GDB continues to improve its handling of C++. `References' work better.
5680 The demangler has also been improved, and now deals with symbols mangled as
5681 per the Annotated C++ Reference Guide.
5683 GDB also now handles `stabs' symbol information embedded in MIPS
5684 `ecoff' symbol tables. Since the ecoff format was not easily
5685 extensible to handle new languages such as C++, this appeared to be a
5686 good way to put C++ debugging info into MIPS binaries. This option
5687 will be supported in the GNU C compiler, version 2, when it is
5690 * New features for SVR4
5692 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5693 shared libraries. Debugging dynamically linked programs should present
5694 only minor differences from debugging statically linked programs.
5696 The `info proc' command will print out information about any process
5697 on an SVR4 system (including the one you are debugging). At the moment,
5698 it prints the address mappings of the process.
5700 If you bring up GDB on another SVR4 system, please send mail to
5701 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5703 * Better dynamic linking support in SunOS
5705 Reading symbols from shared libraries which contain debugging symbols
5706 now works properly. However, there remain issues such as automatic
5707 skipping of `transfer vector' code during function calls, which
5708 make it harder to debug code in a shared library, than to debug the
5709 same code linked statically.
5713 GDB is now using the latest `getopt' routines from the FSF. This
5714 version accepts the -- prefix for options with long names. GDB will
5715 continue to accept the old forms (-option and +option) as well.
5716 Various single letter abbreviations for options have been explicity
5717 added to the option table so that they won't get overshadowed in the
5718 future by other options that begin with the same letter.
5722 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5723 Many assorted bugs have been handled. Many more remain to be handled.
5724 See the various ChangeLog files (primarily in gdb and bfd) for details.
5727 *** Changes in GDB-4.3:
5729 * New machines supported (host and target)
5731 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5732 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5733 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5735 * Almost SCO Unix support
5737 We had hoped to support:
5738 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5739 (except for core file support), but we discovered very late in the release
5740 that it has problems with process groups that render gdb unusable. Sorry
5741 about that. I encourage people to fix it and post the fixes.
5743 * Preliminary ELF and DWARF support
5745 GDB can read ELF object files on System V Release 4, and can handle
5746 debugging records for C, in DWARF format, in ELF files. This support
5747 is preliminary. If you bring up GDB on another SVR4 system, please
5748 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5753 GDB now uses the latest `readline' library. One user-visible change
5754 is that two tabs will list possible command completions, which previously
5755 required typing M-? (meta-question mark, or ESC ?).
5759 The `stepi' bug that many of you noticed has been squashed.
5760 Many bugs in C++ have been handled. Many more remain to be handled.
5761 See the various ChangeLog files (primarily in gdb and bfd) for details.
5763 * State of the MIPS world (in case you wondered):
5765 GDB can understand the symbol tables emitted by the compilers
5766 supplied by most vendors of MIPS-based machines, including DEC. These
5767 symbol tables are in a format that essentially nobody else uses.
5769 Some versions of gcc come with an assembler post-processor called
5770 mips-tfile. This program is required if you want to do source-level
5771 debugging of gcc-compiled programs. I believe FSF does not ship
5772 mips-tfile with gcc version 1, but it will eventually come with gcc
5775 Debugging of g++ output remains a problem. g++ version 1.xx does not
5776 really support it at all. (If you're lucky, you should be able to get
5777 line numbers and stack traces to work, but no parameters or local
5778 variables.) With some work it should be possible to improve the
5781 When gcc version 2 is released, you will have somewhat better luck.
5782 However, even then you will get confusing results for inheritance and
5785 We will eventually provide full debugging of g++ output on
5786 DECstations. This will probably involve some kind of stabs-in-ecoff
5787 encapulation, but the details have not been worked out yet.
5790 *** Changes in GDB-4.2:
5792 * Improved configuration
5794 Only one copy of `configure' exists now, and it is not self-modifying.
5795 Porting BFD is simpler.
5799 The `step' and `next' commands now only stop at the first instruction
5800 of a source line. This prevents the multiple stops that used to occur
5801 in switch statements, for-loops, etc. `Step' continues to stop if a
5802 function that has debugging information is called within the line.
5806 Lots of small bugs fixed. More remain.
5808 * New host supported (not target)
5810 Intel 386 PC clone running Mach i386-none-mach
5813 *** Changes in GDB-4.1:
5815 * Multiple source language support
5817 GDB now has internal scaffolding to handle several source languages.
5818 It determines the type of each source file from its filename extension,
5819 and will switch expression parsing and number formatting to match the
5820 language of the function in the currently selected stack frame.
5821 You can also specifically set the language to be used, with
5822 `set language c' or `set language modula-2'.
5826 GDB now has preliminary support for the GNU Modula-2 compiler,
5827 currently under development at the State University of New York at
5828 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5829 continue through the fall of 1991 and into 1992.
5831 Other Modula-2 compilers are currently not supported, and attempting to
5832 debug programs compiled with them will likely result in an error as the
5833 symbol table is read. Feel free to work on it, though!
5835 There are hooks in GDB for strict type checking and range checking,
5836 in the `Modula-2 philosophy', but they do not currently work.
5840 GDB can now write to executable and core files (e.g. patch
5841 a variable's value). You must turn this switch on, specify
5842 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5843 by assigning a new value to a variable. Modifications take
5846 * Automatic SunOS shared library reading
5848 When you run your program, GDB automatically determines where its
5849 shared libraries (if any) have been loaded, and reads their symbols.
5850 The `share' command is no longer needed. This also works when
5851 examining core files.
5855 You can specify the number of lines that the `list' command shows.
5858 * New machines supported (host and target)
5860 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5861 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5862 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5864 * New hosts supported (not targets)
5866 IBM RT/PC: romp-ibm-aix or rtpc
5868 * New targets supported (not hosts)
5870 AMD 29000 embedded with COFF a29k-none-coff
5871 AMD 29000 embedded with a.out a29k-none-aout
5872 Ultracomputer remote kernel debug a29k-nyu-kern
5874 * New remote interfaces
5880 *** Changes in GDB-4.0:
5884 Wide output is wrapped at good places to make the output more readable.
5886 Gdb now supports cross-debugging from a host machine of one type to a
5887 target machine of another type. Communication with the target system
5888 is over serial lines. The ``target'' command handles connecting to the
5889 remote system; the ``load'' command will download a program into the
5890 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5891 also supports debugging of realtime processes running under VxWorks,
5892 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5893 stub on the target system.
5895 New CPUs supported include the AMD 29000 and Intel 960.
5897 GDB now reads object files and symbol tables via a ``binary file''
5898 library, which allows a single copy of GDB to debug programs of multiple
5899 object file types such as a.out and coff.
5901 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5902 refcard.dvi and refcard.ps are available to format it).
5905 * Control-Variable user interface simplified
5907 All variables that control the operation of the debugger can be set
5908 by the ``set'' command, and displayed by the ``show'' command.
5910 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5911 ``Show prompt'' produces the response:
5912 Gdb's prompt is new-gdb=>.
5914 What follows are the NEW set commands. The command ``help set'' will
5915 print a complete list of old and new set commands. ``help set FOO''
5916 will give a longer description of the variable FOO. ``show'' will show
5917 all of the variable descriptions and their current settings.
5919 confirm on/off: Enables warning questions for operations that are
5920 hard to recover from, e.g. rerunning the program while
5921 it is already running. Default is ON.
5923 editing on/off: Enables EMACS style command line editing
5924 of input. Previous lines can be recalled with
5925 control-P, the current line can be edited with control-B,
5926 you can search for commands with control-R, etc.
5929 history filename NAME: NAME is where the gdb command history
5930 will be stored. The default is .gdb_history,
5931 or the value of the environment variable
5934 history size N: The size, in commands, of the command history. The
5935 default is 256, or the value of the environment variable
5938 history save on/off: If this value is set to ON, the history file will
5939 be saved after exiting gdb. If set to OFF, the
5940 file will not be saved. The default is OFF.
5942 history expansion on/off: If this value is set to ON, then csh-like
5943 history expansion will be performed on
5944 command line input. The default is OFF.
5946 radix N: Sets the default radix for input and output. It can be set
5947 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5948 in the current radix, so "set radix 10" is always a no-op.
5950 height N: This integer value is the number of lines on a page. Default
5951 is 24, the current `stty rows'' setting, or the ``li#''
5952 setting from the termcap entry matching the environment
5955 width N: This integer value is the number of characters on a line.
5956 Default is 80, the current `stty cols'' setting, or the ``co#''
5957 setting from the termcap entry matching the environment
5960 Note: ``set screensize'' is obsolete. Use ``set height'' and
5961 ``set width'' instead.
5963 print address on/off: Print memory addresses in various command displays,
5964 such as stack traces and structure values. Gdb looks
5965 more ``symbolic'' if you turn this off; it looks more
5966 ``machine level'' with it on. Default is ON.
5968 print array on/off: Prettyprint arrays. New convenient format! Default
5971 print demangle on/off: Print C++ symbols in "source" form if on,
5974 print asm-demangle on/off: Same, for assembler level printouts
5977 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5980 * Support for Epoch Environment.
5982 The epoch environment is a version of Emacs v18 with windowing. One
5983 new command, ``inspect'', is identical to ``print'', except that if you
5984 are running in the epoch environment, the value is printed in its own
5988 * Support for Shared Libraries
5990 GDB can now debug programs and core files that use SunOS shared libraries.
5991 Symbols from a shared library cannot be referenced
5992 before the shared library has been linked with the program (this
5993 happens after you type ``run'' and before the function main() is entered).
5994 At any time after this linking (including when examining core files
5995 from dynamically linked programs), gdb reads the symbols from each
5996 shared library when you type the ``sharedlibrary'' command.
5997 It can be abbreviated ``share''.
5999 sharedlibrary REGEXP: Load shared object library symbols for files
6000 matching a unix regular expression. No argument
6001 indicates to load symbols for all shared libraries.
6003 info sharedlibrary: Status of loaded shared libraries.
6008 A watchpoint stops execution of a program whenever the value of an
6009 expression changes. Checking for this slows down execution
6010 tremendously whenever you are in the scope of the expression, but is
6011 quite useful for catching tough ``bit-spreader'' or pointer misuse
6012 problems. Some machines such as the 386 have hardware for doing this
6013 more quickly, and future versions of gdb will use this hardware.
6015 watch EXP: Set a watchpoint (breakpoint) for an expression.
6017 info watchpoints: Information about your watchpoints.
6019 delete N: Deletes watchpoint number N (same as breakpoints).
6020 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6021 enable N: Re-enables watchpoint number N (same as breakpoints).
6024 * C++ multiple inheritance
6026 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6029 * C++ exception handling
6031 Gdb now supports limited C++ exception handling. Besides the existing
6032 ability to breakpoint on an exception handler, gdb can breakpoint on
6033 the raising of an exception (before the stack is peeled back to the
6036 catch FOO: If there is a FOO exception handler in the dynamic scope,
6037 set a breakpoint to catch exceptions which may be raised there.
6038 Multiple exceptions (``catch foo bar baz'') may be caught.
6040 info catch: Lists all exceptions which may be caught in the
6041 current stack frame.
6044 * Minor command changes
6046 The command ``call func (arg, arg, ...)'' now acts like the print
6047 command, except it does not print or save a value if the function's result
6048 is void. This is similar to dbx usage.
6050 The ``up'' and ``down'' commands now always print the frame they end up
6051 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6052 frames without printing.
6054 * New directory command
6056 'dir' now adds directories to the FRONT of the source search path.
6057 The path starts off empty. Source files that contain debug information
6058 about the directory in which they were compiled can be found even
6059 with an empty path; Sun CC and GCC include this information. If GDB can't
6060 find your source file in the current directory, type "dir .".
6062 * Configuring GDB for compilation
6064 For normal use, type ``./configure host''. See README or gdb.texinfo
6067 GDB now handles cross debugging. If you are remotely debugging between
6068 two different machines, type ``./configure host -target=targ''.
6069 Host is the machine where GDB will run; targ is the machine
6070 where the program that you are debugging will run.