1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.9
7 * GDB now honors the content of the file /proc/PID/coredump_filter
8 (PID is the process ID) on GNU/Linux systems. This file can be used
9 to specify the types of memory mappings that will be included in a
10 corefile. For more information, please refer to the manual page of
11 "core(5)". GDB also has a new command: "set use-coredump-filter
12 on|off". It allows to set whether GDB will read the content of the
13 /proc/PID/coredump_filter file when generating a corefile.
15 * The "info os" command on GNU/Linux can now display information on
17 "info os cpus" Listing of all cpus/cores on the system
19 * GDB has two new commands: "set serial parity odd|even|none" and
20 "show serial parity". These allows to set or show parity for the
23 * The "info source" command now displays the producer string if it was
24 present in the debug info. This typically includes the compiler version
25 and may include things like its command line arguments.
27 * Directory names supplied to the "set sysroot" commands may be
28 prefixed with "target:" to tell GDB to access shared libraries from
29 the target system, be it local or remote. This replaces the prefix
30 "remote:". The default sysroot has been changed from "" to
31 "target:". "remote:" is automatically converted to "target:" for
32 backward compatibility.
36 ** gdb.Objfile objects have a new attribute "username",
37 which is the name of the objfile as specified by the user,
38 without, for example, resolving symlinks.
39 ** You can now write frame unwinders in Python.
43 maint print symbol-cache
44 Print the contents of the symbol cache.
46 maint print symbol-cache-statistics
47 Print statistics of symbol cache usage.
49 maint flush-symbol-cache
50 Flush the contents of the symbol cache.
54 Start branch trace recording using Branch Trace Store (BTS) format.
60 Set the maximum number of candidates to be considered during
61 completion. The default value is 200. This limit allows GDB
62 to avoid generating large completion lists, the computation of
63 which can cause the debugger to become temporarily unresponsive.
65 maint set symbol-cache-size
66 maint show symbol-cache-size
67 Control the size of the symbol cache.
69 set|show record btrace bts buffer-size
70 Set and show the size of the ring buffer used for branch tracing in
72 The obtained size may differ from the requested size. Use "info
73 record" to see the obtained buffer size.
75 * The command 'thread apply all' can now support new option '-ascending'
76 to call its specified command for all threads in ascending order.
78 * Python/Guile scripting
80 ** GDB now supports auto-loading of Python/Guile scripts contained in the
81 special section named `.debug_gdb_scripts'.
85 qXfer:btrace-conf:read
86 Return the branch trace configuration for the current thread.
89 Set the requested ring buffer size for branch tracing in BTS format.
92 Indicates a memory breakpoint instruction was executed, irrespective
93 of whether it was GDB that planted the breakpoint or the breakpoint
94 is hardcoded in the program. This is required for correct non-stop
98 Indicates the target stopped for a hardware breakpoint. This is
99 required for correct non-stop mode operation.
102 Return information about files on the remote system.
104 * The info record command now shows the recording format and the
105 branch tracing configuration for the current thread when using
106 the btrace record target.
107 For the BTS format, it shows the ring buffer size.
109 * GDB now has support for DTrace USDT (Userland Static Defined
110 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
112 * GDB now supports access to vector registers on S/390 GNU/Linux
115 * Removed command line options
117 -xdb HP-UX XDB compatibility mode.
119 * Removed targets and native configurations
121 HP/PA running HP-UX hppa*-*-hpux*
122 Itanium running HP-UX ia64-*-hpux*
124 *** Changes in GDB 7.9
126 * GDB now supports hardware watchpoints on x86 GNU Hurd.
130 ** You can now access frame registers from Python scripts.
131 ** New attribute 'producer' for gdb.Symtab objects.
132 ** gdb.Objfile objects have a new attribute "progspace",
133 which is the gdb.Progspace object of the containing program space.
134 ** gdb.Objfile objects have a new attribute "owner".
135 ** gdb.Objfile objects have a new attribute "build_id",
136 which is the build ID generated when the file was built.
137 ** gdb.Objfile objects have a new method "add_separate_debug_file".
138 ** A new event "gdb.clear_objfiles" has been added, triggered when
139 selecting a new file to debug.
140 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
141 ** New function gdb.lookup_objfile.
143 New events which are triggered when GDB modifies the state of the
146 ** gdb.events.inferior_call_pre: Function call is about to be made.
147 ** gdb.events.inferior_call_post: Function call has just been made.
148 ** gdb.events.memory_changed: A memory location has been altered.
149 ** gdb.events.register_changed: A register has been altered.
151 * New Python-based convenience functions:
153 ** $_caller_is(name [, number_of_frames])
154 ** $_caller_matches(regexp [, number_of_frames])
155 ** $_any_caller_is(name [, number_of_frames])
156 ** $_any_caller_matches(regexp [, number_of_frames])
158 * GDB now supports the compilation and injection of source code into
159 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
160 to compile the source code to object code, and if successful, inject
161 and execute that code within the current context of the inferior.
162 Currently the C language is supported. The commands used to
163 interface with this new feature are:
165 compile code [-raw|-r] [--] [source code]
166 compile file [-raw|-r] filename
170 demangle [-l language] [--] name
171 Demangle "name" in the specified language, or the current language
172 if elided. This command is renamed from the "maint demangle" command.
173 The latter is kept as a no-op to avoid "maint demangle" being interpreted
174 as "maint demangler-warning".
176 queue-signal signal-name-or-number
177 Queue a signal to be delivered to the thread when it is resumed.
179 add-auto-load-scripts-directory directory
180 Add entries to the list of directories from which to load auto-loaded
183 maint print user-registers
184 List all currently available "user" registers.
186 compile code [-r|-raw] [--] [source code]
187 Compile, inject, and execute in the inferior the executable object
188 code produced by compiling the provided source code.
190 compile file [-r|-raw] filename
191 Compile and inject into the inferior the executable object code
192 produced by compiling the source code stored in the filename
195 * On resume, GDB now always passes the signal the program had stopped
196 for to the thread the signal was sent to, even if the user changed
197 threads before resuming. Previously GDB would often (but not
198 always) deliver the signal to the thread that happens to be current
201 * Conversely, the "signal" command now consistently delivers the
202 requested signal to the current thread. GDB now asks for
203 confirmation if the program had stopped for a signal and the user
204 switched threads meanwhile.
206 * "breakpoint always-inserted" modes "off" and "auto" merged.
208 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
209 won't remove breakpoints from the target until all threads stop,
210 even in non-stop mode. The "auto" mode has been removed, and "off"
211 is now the default mode.
215 set debug symbol-lookup
216 show debug symbol-lookup
217 Control display of debugging info regarding symbol lookup.
221 ** The -list-thread-groups command outputs an exit-code field for
222 inferiors that have exited.
226 MIPS SDE mips*-sde*-elf*
230 Support for these obsolete configurations has been removed.
232 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
233 SGI Irix-5.x mips-*-irix5*
234 SGI Irix-6.x mips-*-irix6*
235 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
236 VAX running Ultrix vax-*-ultrix*
238 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
239 and "assf"), have been removed. Use the "sharedlibrary" command, or
240 its alias "share", instead.
242 *** Changes in GDB 7.8
244 * New command line options
247 This is an alias for the --data-directory option.
249 * GDB supports printing and modifying of variable length automatic arrays
250 as specified in ISO C99.
252 * The ARM simulator now supports instruction level tracing
253 with or without disassembly.
257 GDB now has support for scripting using Guile. Whether this is
258 available is determined at configure time.
259 Guile version 2.0 or greater is required.
260 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
262 * New commands (for set/show, see "New options" below)
266 Invoke CODE by passing it to the Guile interpreter.
270 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
272 info auto-load guile-scripts [regexp]
273 Print the list of automatically loaded Guile scripts.
275 * The source command is now capable of sourcing Guile scripts.
276 This feature is dependent on the debugger being built with Guile support.
280 set print symbol-loading (off|brief|full)
281 show print symbol-loading
282 Control whether to print informational messages when loading symbol
283 information for a file. The default is "full", but when debugging
284 programs with large numbers of shared libraries the amount of output
287 set guile print-stack (none|message|full)
288 show guile print-stack
289 Show a stack trace when an error is encountered in a Guile script.
291 set auto-load guile-scripts (on|off)
292 show auto-load guile-scripts
293 Control auto-loading of Guile script files.
295 maint ada set ignore-descriptive-types (on|off)
296 maint ada show ignore-descriptive-types
297 Control whether the debugger should ignore descriptive types in Ada
298 programs. The default is not to ignore the descriptive types. See
299 the user manual for more details on descriptive types and the intended
300 usage of this option.
302 set auto-connect-native-target
304 Control whether GDB is allowed to automatically connect to the
305 native target for the run, attach, etc. commands when not connected
306 to any target yet. See also "target native" below.
308 set record btrace replay-memory-access (read-only|read-write)
309 show record btrace replay-memory-access
310 Control what memory accesses are allowed during replay.
312 maint set target-async (on|off)
313 maint show target-async
314 This controls whether GDB targets operate in synchronous or
315 asynchronous mode. Normally the default is asynchronous, if it is
316 available; but this can be changed to more easily debug problems
317 occurring only in synchronous mode.
319 set mi-async (on|off)
321 Control whether MI asynchronous mode is preferred. This supersedes
322 "set target-async" of previous GDB versions.
324 * "set target-async" is deprecated as a CLI option and is now an alias
325 for "set mi-async" (only puts MI into async mode).
327 * Background execution commands (e.g., "c&", "s&", etc.) are now
328 possible ``out of the box'' if the target supports them. Previously
329 the user would need to explicitly enable the possibility with the
330 "set target-async on" command.
332 * New features in the GDB remote stub, GDBserver
334 ** New option --debug-format=option1[,option2,...] allows one to add
335 additional text to each output. At present only timestamps
336 are supported: --debug-format=timestamps.
337 Timestamps can also be turned on with the
338 "monitor set debug-format timestamps" command from GDB.
340 * The 'record instruction-history' command now starts counting instructions
341 at one. This also affects the instruction ranges reported by the
342 'record function-call-history' command when given the /i modifier.
344 * The command 'record function-call-history' supports a new modifier '/c' to
345 indent the function names based on their call stack depth.
346 The fields for the '/i' and '/l' modifier have been reordered.
347 The source line range is now prefixed with 'at'.
348 The instruction range is now prefixed with 'inst'.
349 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
350 "record instruction-history" and "list" commands.
352 * The ranges given as arguments to the 'record function-call-history' and
353 'record instruction-history' commands are now inclusive.
355 * The btrace record target now supports the 'record goto' command.
356 For locations inside the execution trace, the back trace is computed
357 based on the information stored in the execution trace.
359 * The btrace record target supports limited reverse execution and replay.
360 The target does not record data and therefore does not allow reading
363 * The "catch syscall" command now works on s390*-linux* targets.
365 * The "compare-sections" command is no longer specific to target
366 remote. It now works with all targets.
368 * All native targets are now consistently called "native".
369 Consequently, the "target child", "target GNU", "target djgpp",
370 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
371 commands have been replaced with "target native". The QNX/NTO port
372 leaves the "procfs" target in place and adds a "native" target for
373 consistency with other ports. The impact on users should be minimal
374 as these commands previously either throwed an error, or were
375 no-ops. The target's name is visible in the output of the following
376 commands: "help target", "info target", "info files", "maint print
379 * The "target native" command now connects to the native target. This
380 can be used to launch native programs even when "set
381 auto-connect-native-target" is set to off.
383 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.
385 * Support for Intel(R) AVX-512 registers on GNU/Linux.
386 Support displaying and modifying Intel(R) AVX-512 registers
387 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
391 qXfer:btrace:read's annex
392 The qXfer:btrace:read packet supports a new annex 'delta' to read
393 branch trace incrementally.
397 ** Valid Python operations on gdb.Value objects representing
398 structs/classes invoke the corresponding overloaded operators if
400 ** New `Xmethods' feature in the Python API. Xmethods are
401 additional methods or replacements for existing methods of a C++
402 class. This feature is useful for those cases where a method
403 defined in C++ source code could be inlined or optimized out by
404 the compiler, making it unavailable to GDB.
407 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
409 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
410 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
411 its alias "share", instead.
413 * The commands "set remotebaud" and "show remotebaud" are no longer
414 supported. Use "set serial baud" and "show serial baud" (respectively)
419 ** A new option "-gdb-set mi-async" replaces "-gdb-set
420 target-async". The latter is left as a deprecated alias of the
421 former for backward compatibility. If the target supports it,
422 CLI background execution commands are now always possible by
423 default, independently of whether the frontend stated a
424 preference for asynchronous execution with "-gdb-set mi-async".
425 Previously "-gdb-set target-async off" affected both MI execution
426 commands and CLI execution commands.
428 *** Changes in GDB 7.7
430 * Improved support for process record-replay and reverse debugging on
431 arm*-linux* targets. Support for thumb32 and syscall instruction
432 recording has been added.
434 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
436 * GDB now supports Fission DWP file format version 2.
437 http://gcc.gnu.org/wiki/DebugFission
439 * New convenience function "$_isvoid", to check whether an expression
440 is void. A void expression is an expression where the type of the
441 result is "void". For example, some convenience variables may be
442 "void" when evaluated (e.g., "$_exitcode" before the execution of
443 the program being debugged; or an undefined convenience variable).
444 Another example, when calling a function whose return type is
447 * The "maintenance print objfiles" command now takes an optional regexp.
449 * The "catch syscall" command now works on arm*-linux* targets.
451 * GDB now consistently shows "<not saved>" when printing values of
452 registers the debug info indicates have not been saved in the frame
453 and there's nowhere to retrieve them from
454 (callee-saved/call-clobbered registers):
459 (gdb) info registers rax
462 Before, the former would print "<optimized out>", and the latter
463 "*value not available*".
465 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
470 ** Frame filters and frame decorators have been added.
471 ** Temporary breakpoints are now supported.
472 ** Line tables representation has been added.
473 ** New attribute 'parent_type' for gdb.Field objects.
474 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
475 ** New attribute 'name' for gdb.Type objects.
479 Nios II ELF nios2*-*-elf
480 Nios II GNU/Linux nios2*-*-linux
481 Texas Instruments MSP430 msp430*-*-elf
483 * Removed native configurations
485 Support for these a.out NetBSD and OpenBSD obsolete configurations has
486 been removed. ELF variants of these configurations are kept supported.
488 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
489 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
490 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
491 i[34567]86-*-openbsd3.[0-3]
492 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
493 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
494 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
498 Like "catch throw", but catches a re-thrown exception.
500 Renamed from old "maint check-symtabs".
502 Perform consistency checks on symtabs.
504 Expand symtabs matching an optional regexp.
507 Display the details of GDB configure-time options.
509 maint set|show per-command
510 maint set|show per-command space
511 maint set|show per-command time
512 maint set|show per-command symtab
513 Enable display of per-command gdb resource usage.
515 remove-symbol-file FILENAME
516 remove-symbol-file -a ADDRESS
517 Remove a symbol file added via add-symbol-file. The file to remove
518 can be identified by its filename or by an address that lies within
519 the boundaries of this symbol file in memory.
522 info exceptions REGEXP
523 Display the list of Ada exceptions defined in the program being
524 debugged. If provided, only the exceptions whose names match REGEXP
529 set debug symfile off|on
531 Control display of debugging info regarding reading symbol files and
532 symbol tables within those files
534 set print raw frame-arguments
535 show print raw frame-arguments
536 Set/show whether to print frame arguments in raw mode,
537 disregarding any defined pretty-printers.
539 set remote trace-status-packet
540 show remote trace-status-packet
541 Set/show the use of remote protocol qTStatus packet.
545 Control display of debugging messages related to Nios II targets.
549 Control whether target-assisted range stepping is enabled.
551 set startup-with-shell
552 show startup-with-shell
553 Specifies whether Unix child processes are started via a shell or
558 Use the target memory cache for accesses to the code segment. This
559 improves performance of remote debugging (particularly disassembly).
561 * You can now use a literal value 'unlimited' for options that
562 interpret 0 or -1 as meaning "unlimited". E.g., "set
563 trace-buffer-size unlimited" is now an alias for "set
564 trace-buffer-size -1" and "set height unlimited" is now an alias for
567 * The "set debug symtab-create" debugging option of GDB has been changed to
568 accept a verbosity level. 0 means "off", 1 provides basic debugging
569 output, and values of 2 or greater provides more verbose output.
571 * New command-line options
573 Display the details of GDB configure-time options.
575 * The command 'tsave' can now support new option '-ctf' to save trace
576 buffer in Common Trace Format.
578 * Newly installed $prefix/bin/gcore acts as a shell interface for the
581 * GDB now implements the the C++ 'typeid' operator.
583 * The new convenience variable $_exception holds the exception being
584 thrown or caught at an exception-related catchpoint.
586 * The exception-related catchpoints, like "catch throw", now accept a
587 regular expression which can be used to filter exceptions by type.
589 * The new convenience variable $_exitsignal is automatically set to
590 the terminating signal number when the program being debugged dies
591 due to an uncaught signal.
595 ** All MI commands now accept an optional "--language" option.
596 Support for this feature can be verified by using the "-list-features"
597 command, which should contain "language-option".
599 ** The new command -info-gdb-mi-command allows the user to determine
600 whether a GDB/MI command is supported or not.
602 ** The "^error" result record returned when trying to execute an undefined
603 GDB/MI command now provides a variable named "code" whose content is the
604 "undefined-command" error code. Support for this feature can be verified
605 by using the "-list-features" command, which should contain
606 "undefined-command-error-code".
608 ** The -trace-save MI command can optionally save trace buffer in Common
611 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
613 ** The command -data-list-register-values now accepts an optional
614 "--skip-unavailable" option. When used, only the available registers
617 ** The new command -trace-frame-collected dumps collected variables,
618 computed expressions, tvars, memory and registers in a traceframe.
620 ** The commands -stack-list-locals, -stack-list-arguments and
621 -stack-list-variables now accept an option "--skip-unavailable".
622 When used, only the available locals or arguments are displayed.
624 ** The -exec-run command now accepts an optional "--start" option.
625 When used, the command follows the same semantics as the "start"
626 command, stopping the program's execution at the start of its
627 main subprogram. Support for this feature can be verified using
628 the "-list-features" command, which should contain
629 "exec-run-start-option".
631 ** The new commands -catch-assert and -catch-exceptions insert
632 catchpoints stopping the program when Ada exceptions are raised.
634 ** The new command -info-ada-exceptions provides the equivalent of
635 the new "info exceptions" command.
637 * New system-wide configuration scripts
638 A GDB installation now provides scripts suitable for use as system-wide
639 configuration scripts for the following systems:
643 * GDB now supports target-assigned range stepping with remote targets.
644 This improves the performance of stepping source lines by reducing
645 the number of control packets from/to GDB. See "New remote packets"
648 * GDB now understands the element 'tvar' in the XML traceframe info.
649 It has the id of the collected trace state variables.
651 * On S/390 targets that provide the transactional-execution feature,
652 the program interruption transaction diagnostic block (TDB) is now
653 represented as a number of additional "registers" in GDB.
659 The vCont packet supports a new 'r' action, that tells the remote
660 stub to step through an address range itself, without GDB
661 involvemement at each single-step.
663 qXfer:libraries-svr4:read's annex
664 The previously unused annex of the qXfer:libraries-svr4:read packet
665 is now used to support passing an argument list. The remote stub
666 reports support for this argument list to GDB's qSupported query.
667 The defined arguments are "start" and "prev", used to reduce work
668 necessary for library list updating, resulting in significant
671 * New features in the GDB remote stub, GDBserver
673 ** GDBserver now supports target-assisted range stepping. Currently
674 enabled on x86/x86_64 GNU/Linux targets.
676 ** GDBserver now adds element 'tvar' in the XML in the reply to
677 'qXfer:traceframe-info:read'. It has the id of the collected
678 trace state variables.
680 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
683 * New 'z' formatter for printing and examining memory, this displays the
684 value as hexadecimal zero padded on the left to the size of the type.
686 * GDB can now use Windows x64 unwinding data.
688 * The "set remotebaud" command has been replaced by "set serial baud".
689 Similarly, "show remotebaud" has been replaced by "show serial baud".
690 The "set remotebaud" and "show remotebaud" commands are still available
691 to provide backward compatibility with older versions of GDB.
693 *** Changes in GDB 7.6
695 * Target record has been renamed to record-full.
696 Record/replay is now enabled with the "record full" command.
697 This also affects settings that are associated with full record/replay
698 that have been moved from "set/show record" to "set/show record full":
700 set|show record full insn-number-max
701 set|show record full stop-at-limit
702 set|show record full memory-query
704 * A new record target "record-btrace" has been added. The new target
705 uses hardware support to record the control-flow of a process. It
706 does not support replaying the execution, but it implements the
707 below new commands for investigating the recorded execution log.
708 This new recording method can be enabled using:
712 The "record-btrace" target is only available on Intel Atom processors
713 and requires a Linux kernel 2.6.32 or later.
715 * Two new commands have been added for record/replay to give information
716 about the recorded execution without having to replay the execution.
717 The commands are only supported by "record btrace".
719 record instruction-history prints the execution history at
720 instruction granularity
722 record function-call-history prints the execution history at
725 * New native configurations
727 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
728 FreeBSD/powerpc powerpc*-*-freebsd
729 x86_64/Cygwin x86_64-*-cygwin*
730 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
734 ARM AArch64 aarch64*-*-elf
735 ARM AArch64 GNU/Linux aarch64*-*-linux
736 Lynx 178 PowerPC powerpc-*-lynx*178
737 x86_64/Cygwin x86_64-*-cygwin*
738 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
740 * If the configured location of system.gdbinit file (as given by the
741 --with-system-gdbinit option at configure time) is in the
742 data-directory (as specified by --with-gdb-datadir at configure
743 time) or in one of its subdirectories, then GDB will look for the
744 system-wide init file in the directory specified by the
745 --data-directory command-line option.
747 * New command line options:
749 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
750 other initialization files, unlike -nx which disables all of them.
752 * Removed command line options
754 -epoch This was used by the gdb mode in Epoch, an ancient fork of
757 * The 'ptype' and 'whatis' commands now accept an argument to control
760 * 'info proc' now works on some core files.
764 ** Vectors can be created with gdb.Type.vector.
766 ** Python's atexit.register now works in GDB.
768 ** Types can be pretty-printed via a Python API.
770 ** Python 3 is now supported (in addition to Python 2.4 or later)
772 ** New class gdb.Architecture exposes GDB's internal representation
773 of architecture in the Python API.
775 ** New method Frame.architecture returns the gdb.Architecture object
776 corresponding to the frame's architecture.
778 * New Python-based convenience functions:
780 ** $_memeq(buf1, buf2, length)
781 ** $_streq(str1, str2)
783 ** $_regex(str, regex)
785 * The 'cd' command now defaults to using '~' (the home directory) if not
788 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
789 default for GCC since November 2000.
791 * The command 'forward-search' can now be abbreviated as 'fo'.
793 * The command 'info tracepoints' can now display 'installed on target'
794 or 'not installed on target' for each non-pending location of tracepoint.
796 * New configure options
798 --enable-libmcheck/--disable-libmcheck
799 By default, development versions are built with -lmcheck on hosts
800 that support it, in order to help track memory corruption issues.
801 Release versions, on the other hand, are built without -lmcheck
802 by default. The --enable-libmcheck/--disable-libmcheck configure
803 options allow the user to override that default.
804 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
805 This configure option allows the user to build GDB with
806 libbabeltrace using which GDB can read Common Trace Format data.
808 * New commands (for set/show, see "New options" below)
811 Catch signals. This is similar to "handle", but allows commands and
812 conditions to be attached.
815 List the BFDs known to GDB.
817 python-interactive [command]
819 Start a Python interactive prompt, or evaluate the optional command
820 and print the result of expressions.
823 "py" is a new alias for "python".
825 enable type-printer [name]...
826 disable type-printer [name]...
827 Enable or disable type printers.
831 ** For the Renesas Super-H architecture, the "regs" command has been removed
832 (has been deprecated in GDB 7.5), and "info all-registers" should be used
837 set print type methods (on|off)
838 show print type methods
839 Control whether method declarations are displayed by "ptype".
840 The default is to show them.
842 set print type typedefs (on|off)
843 show print type typedefs
844 Control whether typedef definitions are displayed by "ptype".
845 The default is to show them.
847 set filename-display basename|relative|absolute
848 show filename-display
849 Control the way in which filenames is displayed.
850 The default is "relative", which preserves previous behavior.
852 set trace-buffer-size
853 show trace-buffer-size
854 Request target to change the size of trace buffer.
856 set remote trace-buffer-size-packet auto|on|off
857 show remote trace-buffer-size-packet
858 Control the use of the remote protocol `QTBuffer:size' packet.
862 Control display of debugging messages related to ARM AArch64.
865 set debug coff-pe-read
866 show debug coff-pe-read
867 Control display of debugging messages related to reading of COFF/PE
872 Control display of debugging messages related to Mach-O symbols
875 set debug notification
876 show debug notification
877 Control display of debugging info for async remote notification.
881 ** Command parameter changes are now notified using new async record
882 "=cmd-param-changed".
883 ** Trace frame changes caused by command "tfind" are now notified using
884 new async record "=traceframe-changed".
885 ** The creation, deletion and modification of trace state variables
886 are now notified using new async records "=tsv-created",
887 "=tsv-deleted" and "=tsv-modified".
888 ** The start and stop of process record are now notified using new
889 async record "=record-started" and "=record-stopped".
890 ** Memory changes are now notified using new async record
892 ** The data-disassemble command response will include a "fullname" field
893 containing the absolute file name when source has been requested.
894 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
895 command, to allow pattern filling of memory areas.
896 ** New commands "-catch-load"/"-catch-unload" added for intercepting
897 library load/unload events.
898 ** The response to breakpoint commands and breakpoint async records
899 includes an "installed" field containing a boolean state about each
900 non-pending tracepoint location is whether installed on target or not.
901 ** Output of the "-trace-status" command includes a "trace-file" field
902 containing the name of the trace file being examined. This field is
903 optional, and only present when examining a trace file.
904 ** The "fullname" field is now always present along with the "file" field,
905 even if the file cannot be found by GDB.
907 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
908 You must have the LZMA library available when configuring GDB for this
909 feature to be enabled. For more information, see:
910 http://fedoraproject.org/wiki/Features/MiniDebugInfo
915 Set the size of trace buffer. The remote stub reports support for this
916 packet to gdb's qSupported query.
919 Enable Branch Trace Store (BTS)-based branch tracing for the current
920 thread. The remote stub reports support for this packet to gdb's
924 Disable branch tracing for the current thread. The remote stub reports
925 support for this packet to gdb's qSupported query.
928 Read the traced branches for the current thread. The remote stub
929 reports support for this packet to gdb's qSupported query.
931 *** Changes in GDB 7.5
933 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
934 for more x32 ABI info.
936 * GDB now supports access to MIPS DSP registers on Linux targets.
938 * GDB now supports debugging microMIPS binaries.
940 * The "info os" command on GNU/Linux can now display information on
941 several new classes of objects managed by the operating system:
942 "info os procgroups" lists process groups
943 "info os files" lists file descriptors
944 "info os sockets" lists internet-domain sockets
945 "info os shm" lists shared-memory regions
946 "info os semaphores" lists semaphores
947 "info os msg" lists message queues
948 "info os modules" lists loaded kernel modules
950 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
951 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
952 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
953 options and inspect the probe arguments using the new $_probe_arg family
954 of convenience variables. You can obtain more information about SystemTap
955 in <http://sourceware.org/systemtap/>.
957 * GDB now supports reversible debugging on ARM, it allows you to
958 debug basic ARM and THUMB instructions, and provides
959 record/replay support.
961 * The option "symbol-reloading" has been deleted as it is no longer used.
965 ** GDB commands implemented in Python can now be put in command class
968 ** The "maint set python print-stack on|off" is now deleted.
970 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
971 apply "flag enum"-style pretty-printing to any enum.
973 ** gdb.lookup_symbol can now work when there is no current frame.
975 ** gdb.Symbol now has a 'line' attribute, holding the line number in
976 the source at which the symbol was defined.
978 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
979 method 'value'. The former indicates whether the symbol needs a
980 frame in order to compute its value, and the latter computes the
983 ** A new method 'referenced_value' on gdb.Value objects which can
984 dereference pointer as well as C++ reference values.
986 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
987 which return the global and static blocks (as gdb.Block objects),
988 of the underlying symbol table, respectively.
990 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
991 object associated with a PC value.
993 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
994 of the address range occupied by code for the current source line.
996 * Go language support.
997 GDB now supports debugging programs written in the Go programming
1000 * GDBserver now supports stdio connections.
1001 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1003 * The binary "gdbtui" can no longer be built or installed.
1004 Use "gdb -tui" instead.
1006 * GDB will now print "flag" enums specially. A flag enum is one where
1007 all the enumerator values have no bits in common when pairwise
1008 "and"ed. When printing a value whose type is a flag enum, GDB will
1009 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1010 (gdb) print (enum E) 3
1013 * The filename part of a linespec will now match trailing components
1014 of a source file name. For example, "break gcc/expr.c:1000" will
1015 now set a breakpoint in build/gcc/expr.c, but not
1016 build/libcpp/expr.c.
1018 * The "info proc" and "generate-core-file" commands will now also
1019 work on remote targets connected to GDBserver on Linux.
1021 * The command "info catch" has been removed. It has been disabled
1022 since December 2007.
1024 * The "catch exception" and "catch assert" commands now accept
1025 a condition at the end of the command, much like the "break"
1026 command does. For instance:
1028 (gdb) catch exception Constraint_Error if Barrier = True
1030 Previously, it was possible to add a condition to such catchpoints,
1031 but it had to be done as a second step, after the catchpoint had been
1032 created, using the "condition" command.
1034 * The "info static-tracepoint-marker" command will now also work on
1035 native Linux targets with in-process agent.
1037 * GDB can now set breakpoints on inlined functions.
1039 * The .gdb_index section has been updated to include symbols for
1040 inlined functions. GDB will ignore older .gdb_index sections by
1041 default, which could cause symbol files to be loaded more slowly
1042 until their .gdb_index sections can be recreated. The new command
1043 "set use-deprecated-index-sections on" will cause GDB to use any older
1044 .gdb_index sections it finds. This will restore performance, but the
1045 ability to set breakpoints on inlined functions will be lost in symbol
1046 files with older .gdb_index sections.
1048 The .gdb_index section has also been updated to record more information
1049 about each symbol. This speeds up the "info variables", "info functions"
1050 and "info types" commands when used with programs having the .gdb_index
1051 section, as well as speeding up debugging with shared libraries using
1052 the .gdb_index section.
1054 * Ada support for GDB/MI Variable Objects has been added.
1056 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1061 ** New command -info-os is the MI equivalent of "info os".
1063 ** Output logs ("set logging" and related) now include MI output.
1067 ** "set use-deprecated-index-sections on|off"
1068 "show use-deprecated-index-sections on|off"
1069 Controls the use of deprecated .gdb_index sections.
1071 ** "catch load" and "catch unload" can be used to stop when a shared
1072 library is loaded or unloaded, respectively.
1074 ** "enable count" can be used to auto-disable a breakpoint after
1077 ** "info vtbl" can be used to show the virtual method tables for
1078 C++ and Java objects.
1080 ** "explore" and its sub commands "explore value" and "explore type"
1081 can be used to recursively explore values and types of
1082 expressions. These commands are available only if GDB is
1083 configured with '--with-python'.
1085 ** "info auto-load" shows status of all kinds of auto-loaded files,
1086 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1087 sequences of commands files, "info auto-load python-scripts"
1088 shows status of auto-loading Python script files,
1089 "info auto-load local-gdbinit" shows status of loading init file
1090 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1091 status of inferior specific thread debugging shared library loading.
1093 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1094 and "show auto-load-scripts" commands have been deprecated, use their
1095 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1096 and "show auto-load python-scripts" counterparts instead.
1098 ** "dprintf location,format,args..." creates a dynamic printf, which
1099 is basically a breakpoint that does a printf and immediately
1100 resumes your program's execution, so it is like a printf that you
1101 can insert dynamically at runtime instead of at compiletime.
1103 ** "set print symbol"
1105 Controls whether GDB attempts to display the symbol, if any,
1106 corresponding to addresses it prints. This defaults to "on", but
1107 you can set it to "off" to restore GDB's previous behavior.
1109 * Deprecated commands
1111 ** For the Renesas Super-H architecture, the "regs" command has been
1112 deprecated, and "info all-registers" should be used instead.
1116 Renesas RL78 rl78-*-elf
1117 HP OpenVMS ia64 ia64-hp-openvms*
1119 * GDBserver supports evaluation of breakpoint conditions. When
1120 support is advertised by GDBserver, GDB may be told to send the
1121 breakpoint conditions in bytecode form to GDBserver. GDBserver
1122 will only report the breakpoint trigger to GDB when its condition
1127 set mips compression
1128 show mips compression
1129 Select the compressed ISA encoding used in functions that have no symbol
1130 information available. The encoding can be set to either of:
1133 and is updated automatically from ELF file flags if available.
1135 set breakpoint condition-evaluation
1136 show breakpoint condition-evaluation
1137 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1138 GDBserver ("target"). Default option "auto" chooses the most efficient
1140 This option can improve debugger efficiency depending on the speed of the
1144 Disable auto-loading globally.
1147 Show auto-loading setting of all kinds of auto-loaded files.
1149 set auto-load gdb-scripts on|off
1150 show auto-load gdb-scripts
1151 Control auto-loading of GDB canned sequences of commands files.
1153 set auto-load python-scripts on|off
1154 show auto-load python-scripts
1155 Control auto-loading of Python script files.
1157 set auto-load local-gdbinit on|off
1158 show auto-load local-gdbinit
1159 Control loading of init file (.gdbinit) from current directory.
1161 set auto-load libthread-db on|off
1162 show auto-load libthread-db
1163 Control auto-loading of inferior specific thread debugging shared library.
1165 set auto-load scripts-directory <dir1>[:<dir2>...]
1166 show auto-load scripts-directory
1167 Set a list of directories from which to load auto-loaded scripts.
1168 Automatically loaded Python scripts and GDB scripts are located in one
1169 of the directories listed by this option.
1170 The delimiter (':' above) may differ according to the host platform.
1172 set auto-load safe-path <dir1>[:<dir2>...]
1173 show auto-load safe-path
1174 Set a list of directories from which it is safe to auto-load files.
1175 The delimiter (':' above) may differ according to the host platform.
1177 set debug auto-load on|off
1178 show debug auto-load
1179 Control display of debugging info for auto-loading the files above.
1181 set dprintf-style gdb|call|agent
1183 Control the way in which a dynamic printf is performed; "gdb"
1184 requests a GDB printf command, while "call" causes dprintf to call a
1185 function in the inferior. "agent" requests that the target agent
1186 (such as GDBserver) do the printing.
1188 set dprintf-function <expr>
1189 show dprintf-function
1190 set dprintf-channel <expr>
1191 show dprintf-channel
1192 Set the function and optional first argument to the call when using
1193 the "call" style of dynamic printf.
1195 set disconnected-dprintf on|off
1196 show disconnected-dprintf
1197 Control whether agent-style dynamic printfs continue to be in effect
1198 after GDB disconnects.
1200 * New configure options
1202 --with-auto-load-dir
1203 Configure default value for the 'set auto-load scripts-directory'
1204 setting above. It defaults to '$debugdir:$datadir/auto-load',
1205 $debugdir representing global debugging info directories (available
1206 via 'show debug-file-directory') and $datadir representing GDB's data
1207 directory (available via 'show data-directory').
1209 --with-auto-load-safe-path
1210 Configure default value for the 'set auto-load safe-path' setting
1211 above. It defaults to the --with-auto-load-dir setting.
1213 --without-auto-load-safe-path
1214 Set 'set auto-load safe-path' to '/', effectively disabling this
1217 * New remote packets
1219 z0/z1 conditional breakpoints extension
1221 The z0/z1 breakpoint insertion packets have been extended to carry
1222 a list of conditional expressions over to the remote stub depending on the
1223 condition evaluation mode. The use of this extension can be controlled
1224 via the "set remote conditional-breakpoints-packet" command.
1228 Specify the signals which the remote stub may pass to the debugged
1229 program without GDB involvement.
1231 * New command line options
1233 --init-command=FILE, -ix Like --command, -x but execute it
1234 before loading inferior.
1235 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1236 execute it before loading inferior.
1238 *** Changes in GDB 7.4
1240 * GDB now handles ambiguous linespecs more consistently; the existing
1241 FILE:LINE support has been expanded to other types of linespecs. A
1242 breakpoint will now be set on all matching locations in all
1243 inferiors, and locations will be added or removed according to
1246 * GDB now allows you to skip uninteresting functions and files when
1247 stepping with the "skip function" and "skip file" commands.
1249 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1250 and "show remote hardware-watchpoint-length-limit". These allows to
1251 set or show the maximum length limit (in bytes) of a remote
1252 target hardware watchpoint.
1254 This allows e.g. to use "unlimited" hardware watchpoints with the
1255 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1256 watchpoints are slower than real hardware watchpoints but are
1257 significantly faster than gdb software watchpoints.
1261 ** The register_pretty_printer function in module gdb.printing now takes
1262 an optional `replace' argument. If True, the new printer replaces any
1265 ** The "maint set python print-stack on|off" command has been
1266 deprecated and will be deleted in GDB 7.5.
1267 A new command: "set python print-stack none|full|message" has
1268 replaced it. Additionally, the default for "print-stack" is
1269 now "message", which just prints the error message without
1272 ** A prompt substitution hook (prompt_hook) is now available to the
1275 ** A new Python module, gdb.prompt has been added to the GDB Python
1276 modules library. This module provides functionality for
1277 escape sequences in prompts (used by set/show
1278 extended-prompt). These escape sequences are replaced by their
1279 corresponding value.
1281 ** Python commands and convenience-functions located in
1282 'data-directory'/python/gdb/command and
1283 'data-directory'/python/gdb/function are now automatically loaded
1286 ** Blocks now provide four new attributes. global_block and
1287 static_block will return the global and static blocks
1288 respectively. is_static and is_global are boolean attributes
1289 that indicate if the block is one of those two types.
1291 ** Symbols now provide the "type" attribute, the type of the symbol.
1293 ** The "gdb.breakpoint" function has been deprecated in favor of
1296 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1297 of a function. This class is based on the "finish" command
1298 available in the CLI.
1300 ** Type objects for struct and union types now allow access to
1301 the fields using standard Python dictionary (mapping) methods.
1302 For example, "some_type['myfield']" now works, as does
1303 "some_type.items()".
1305 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1308 ** A new function, "deep_items" has been added to the gdb.types
1309 module in the GDB Python modules library. This function returns
1310 an iterator over the fields of a struct or union type. Unlike
1311 the standard Python "iteritems" method, it will recursively traverse
1312 any anonymous fields.
1316 ** "*stopped" events can report several new "reason"s, such as
1319 ** Breakpoint changes are now notified using new async records, like
1320 "=breakpoint-modified".
1322 ** New command -ada-task-info.
1324 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1325 $sdir specifies the default system locations of shared libraries.
1326 $pdir specifies the directory where the libpthread used by the application
1329 GDB no longer looks in $sdir and $pdir after it has searched the directories
1330 mentioned in libthread-db-search-path. If you want to search those
1331 directories, they must be specified in libthread-db-search-path.
1332 The default value of libthread-db-search-path on GNU/Linux and Solaris
1333 systems is now "$sdir:$pdir".
1335 $pdir is not supported by gdbserver, it is currently ignored.
1336 $sdir is supported by gdbserver.
1338 * New configure option --with-iconv-bin.
1339 When using the internationalization support like the one in the GNU C
1340 library, GDB will invoke the "iconv" program to get a list of supported
1341 character sets. If this program lives in a non-standard location, one can
1342 use this option to specify where to find it.
1344 * When natively debugging programs on PowerPC BookE processors running
1345 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1346 watchpoints, which specify a mask in addition to an address to watch.
1347 The mask specifies that some bits of an address (the bits which are
1348 reset in the mask) should be ignored when matching the address accessed
1349 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1350 section in the user manual for more details.
1352 * The new option --once causes GDBserver to stop listening for connections once
1353 the first connection is made. The listening port used by GDBserver will
1354 become available after that.
1356 * New commands "info macros" and "alias" have been added.
1358 * New function parameters suffix @entry specifies value of function parameter
1359 at the time the function got called. Entry values are available only since
1365 "!" is now an alias of the "shell" command.
1366 Note that no space is needed between "!" and SHELL COMMAND.
1370 watch EXPRESSION mask MASK_VALUE
1371 The watch command now supports the mask argument which allows creation
1372 of masked watchpoints, if the current architecture supports this feature.
1374 info auto-load-scripts [REGEXP]
1375 This command was formerly named "maintenance print section-scripts".
1376 It is now generally useful and is no longer a maintenance-only command.
1378 info macro [-all] [--] MACRO
1379 The info macro command has new options `-all' and `--'. The first for
1380 printing all definitions of a macro. The second for explicitly specifying
1381 the end of arguments and the beginning of the macro name in case the macro
1382 name starts with a hyphen.
1384 collect[/s] EXPRESSIONS
1385 The tracepoint collect command now takes an optional modifier "/s"
1386 that directs it to dereference pointer-to-character types and
1387 collect the bytes of memory up to a zero byte. The behavior is
1388 similar to what you see when you use the regular print command on a
1389 string. An optional integer following the "/s" sets a bound on the
1390 number of bytes that will be collected.
1393 The trace start command now interprets any supplied arguments as a
1394 note to be recorded with the trace run, with an effect similar to
1395 setting the variable trace-notes.
1398 The trace stop command now interprets any arguments as a note to be
1399 mentioned along with the tstatus report that the trace was stopped
1400 with a command. The effect is similar to setting the variable
1403 * Tracepoints can now be enabled and disabled at any time after a trace
1404 experiment has been started using the standard "enable" and "disable"
1405 commands. It is now possible to start a trace experiment with no enabled
1406 tracepoints; GDB will display a warning, but will allow the experiment to
1407 begin, assuming that tracepoints will be enabled as needed while the trace
1410 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1411 locations with 4-byte instructions, when they were previously
1412 limited to locations with instructions of 5 bytes or longer.
1416 set debug dwarf2-read
1417 show debug dwarf2-read
1418 Turns on or off display of debugging messages related to reading
1419 DWARF debug info. The default is off.
1421 set debug symtab-create
1422 show debug symtab-create
1423 Turns on or off display of debugging messages related to symbol table
1424 creation. The default is off.
1427 show extended-prompt
1428 Set the GDB prompt, and allow escape sequences to be inserted to
1429 display miscellaneous information (see 'help set extended-prompt'
1430 for the list of sequences). This prompt (and any information
1431 accessed through the escape sequences) is updated every time the
1432 prompt is displayed.
1434 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1435 show print entry-values
1436 Set printing of frame argument values at function entry. In some cases
1437 GDB can determine the value of function argument which was passed by the
1438 function caller, even if the value was modified inside the called function.
1440 set debug entry-values
1441 show debug entry-values
1442 Control display of debugging info for determining frame argument values at
1443 function entry and virtual tail call frames.
1445 set basenames-may-differ
1446 show basenames-may-differ
1447 Set whether a source file may have multiple base names.
1448 (A "base name" is the name of a file with the directory part removed.
1449 Example: The base name of "/home/user/hello.c" is "hello.c".)
1450 If set, GDB will canonicalize file names (e.g., expand symlinks)
1451 before comparing them. Canonicalization is an expensive operation,
1452 but it allows the same file be known by more than one base name.
1453 If not set (the default), all source files are assumed to have just
1454 one base name, and gdb will do file name comparisons more efficiently.
1460 Set a user name and notes for the current and any future trace runs.
1461 This is useful for long-running and/or disconnected traces, to
1462 inform others (or yourself) as to who is running the trace, supply
1463 contact information, or otherwise explain what is going on.
1465 set trace-stop-notes
1466 show trace-stop-notes
1467 Set a note attached to the trace run, that is displayed when the
1468 trace has been stopped by a tstop command. This is useful for
1469 instance as an explanation, if you are stopping a trace run that was
1470 started by someone else.
1472 * New remote packets
1476 Dynamically enable a tracepoint in a started trace experiment.
1480 Dynamically disable a tracepoint in a started trace experiment.
1484 Set the user and notes of the trace run.
1488 Query the current status of a tracepoint.
1492 Query the minimum length of instruction at which a fast tracepoint may
1495 * Dcache size (number of lines) and line-size are now runtime-configurable
1496 via "set dcache line" and "set dcache line-size" commands.
1500 Texas Instruments TMS320C6x tic6x-*-*
1504 Renesas RL78 rl78-*-elf
1506 *** Changes in GDB 7.3.1
1508 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1510 *** Changes in GDB 7.3
1512 * GDB has a new command: "thread find [REGEXP]".
1513 It finds the thread id whose name, target id, or thread extra info
1514 matches the given regular expression.
1516 * The "catch syscall" command now works on mips*-linux* targets.
1518 * The -data-disassemble MI command now supports modes 2 and 3 for
1519 dumping the instruction opcodes.
1521 * New command line options
1523 -data-directory DIR Specify DIR as the "data-directory".
1524 This is mostly for testing purposes.
1526 * The "maint set python auto-load on|off" command has been renamed to
1527 "set auto-load-scripts on|off".
1529 * GDB has a new command: "set directories".
1530 It is like the "dir" command except that it replaces the
1531 source path list instead of augmenting it.
1533 * GDB now understands thread names.
1535 On GNU/Linux, "info threads" will display the thread name as set by
1536 prctl or pthread_setname_np.
1538 There is also a new command, "thread name", which can be used to
1539 assign a name internally for GDB to display.
1542 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1543 has been integrated into GDB.
1547 ** The function gdb.Write now accepts an optional keyword 'stream'.
1548 This keyword, when provided, will direct the output to either
1549 stdout, stderr, or GDB's logging output.
1551 ** Parameters can now be be sub-classed in Python, and in particular
1552 you may implement the get_set_doc and get_show_doc functions.
1553 This improves how Parameter set/show documentation is processed
1554 and allows for more dynamic content.
1556 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1557 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1558 have an is_valid method.
1560 ** Breakpoints can now be sub-classed in Python, and in particular
1561 you may implement a 'stop' function that is executed each time
1562 the inferior reaches that breakpoint.
1564 ** New function gdb.lookup_global_symbol looks up a global symbol.
1566 ** GDB values in Python are now callable if the value represents a
1567 function. For example, if 'some_value' represents a function that
1568 takes two integer parameters and returns a value, you can call
1569 that function like so:
1571 result = some_value (10,20)
1573 ** Module gdb.types has been added.
1574 It contains a collection of utilities for working with gdb.Types objects:
1575 get_basic_type, has_field, make_enum_dict.
1577 ** Module gdb.printing has been added.
1578 It contains utilities for writing and registering pretty-printers.
1579 New classes: PrettyPrinter, SubPrettyPrinter,
1580 RegexpCollectionPrettyPrinter.
1581 New function: register_pretty_printer.
1583 ** New commands "info pretty-printers", "enable pretty-printer" and
1584 "disable pretty-printer" have been added.
1586 ** gdb.parameter("directories") is now available.
1588 ** New function gdb.newest_frame returns the newest frame in the
1591 ** The gdb.InferiorThread class has a new "name" attribute. This
1592 holds the thread's name.
1594 ** Python Support for Inferior events.
1595 Python scripts can add observers to be notified of events
1596 occurring in the process being debugged.
1597 The following events are currently supported:
1598 - gdb.events.cont Continue event.
1599 - gdb.events.exited Inferior exited event.
1600 - gdb.events.stop Signal received, and Breakpoint hit events.
1604 ** GDB now puts template parameters in scope when debugging in an
1605 instantiation. For example, if you have:
1607 template<int X> int func (void) { return X; }
1609 then if you step into func<5>, "print X" will show "5". This
1610 feature requires proper debuginfo support from the compiler; it
1611 was added to GCC 4.5.
1613 ** The motion commands "next", "finish", "until", and "advance" now
1614 work better when exceptions are thrown. In particular, GDB will
1615 no longer lose control of the inferior; instead, the GDB will
1616 stop the inferior at the point at which the exception is caught.
1617 This functionality requires a change in the exception handling
1618 code that was introduced in GCC 4.5.
1620 * GDB now follows GCC's rules on accessing volatile objects when
1621 reading or writing target state during expression evaluation.
1622 One notable difference to prior behavior is that "print x = 0"
1623 no longer generates a read of x; the value of the assignment is
1624 now always taken directly from the value being assigned.
1626 * GDB now has some support for using labels in the program's source in
1627 linespecs. For instance, you can use "advance label" to continue
1628 execution to a label.
1630 * GDB now has support for reading and writing a new .gdb_index
1631 section. This section holds a fast index of DWARF debugging
1632 information and can be used to greatly speed up GDB startup and
1633 operation. See the documentation for `save gdb-index' for details.
1635 * The "watch" command now accepts an optional "-location" argument.
1636 When used, this causes GDB to watch the memory referred to by the
1637 expression. Such a watchpoint is never deleted due to it going out
1640 * GDB now supports thread debugging of core dumps on GNU/Linux.
1642 GDB now activates thread debugging using the libthread_db library
1643 when debugging GNU/Linux core dumps, similarly to when debugging
1644 live processes. As a result, when debugging a core dump file, GDB
1645 is now able to display pthread_t ids of threads. For example, "info
1646 threads" shows the same output as when debugging the process when it
1647 was live. In earlier releases, you'd see something like this:
1650 * 1 LWP 6780 main () at main.c:10
1652 While now you see this:
1655 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1657 It is also now possible to inspect TLS variables when debugging core
1660 When debugging a core dump generated on a machine other than the one
1661 used to run GDB, you may need to point GDB at the correct
1662 libthread_db library with the "set libthread-db-search-path"
1663 command. See the user manual for more details on this command.
1665 * When natively debugging programs on PowerPC BookE processors running
1666 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1667 which stop execution of the inferior whenever it executes an instruction
1668 at any address within the specified range. See the "PowerPC Embedded"
1669 section in the user manual for more details.
1671 * New features in the GDB remote stub, GDBserver
1673 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1674 and i686 LynxOS (version 5.x).
1676 ** GDBserver is now supported on Blackfin Linux.
1678 * New native configurations
1680 ia64 HP-UX ia64-*-hpux*
1684 Analog Devices, Inc. Blackfin Processor bfin-*
1686 * Ada task switching is now supported on sparc-elf targets when
1687 debugging a program using the Ravenscar Profile. For more information,
1688 see the "Tasking Support when using the Ravenscar Profile" section
1689 in the GDB user manual.
1691 * Guile support was removed.
1693 * New features in the GNU simulator
1695 ** The --map-info flag lists all known core mappings.
1697 ** CFI flashes may be simulated via the "cfi" device.
1699 *** Changes in GDB 7.2
1701 * Shared library support for remote targets by default
1703 When GDB is configured for a generic, non-OS specific target, like
1704 for example, --target=arm-eabi or one of the many *-*-elf targets,
1705 GDB now queries remote stubs for loaded shared libraries using the
1706 `qXfer:libraries:read' packet. Previously, shared library support
1707 was always disabled for such configurations.
1711 ** Argument Dependent Lookup (ADL)
1713 In C++ ADL lookup directs function search to the namespaces of its
1714 arguments even if the namespace has not been imported.
1724 Here the compiler will search for `foo' in the namespace of 'b'
1725 and find A::foo. GDB now supports this. This construct is commonly
1726 used in the Standard Template Library for operators.
1728 ** Improved User Defined Operator Support
1730 In addition to member operators, GDB now supports lookup of operators
1731 defined in a namespace and imported with a `using' directive, operators
1732 defined in the global scope, operators imported implicitly from an
1733 anonymous namespace, and the ADL operators mentioned in the previous
1735 GDB now also supports proper overload resolution for all the previously
1736 mentioned flavors of operators.
1738 ** static const class members
1740 Printing of static const class members that are initialized in the
1741 class definition has been fixed.
1743 * Windows Thread Information Block access.
1745 On Windows targets, GDB now supports displaying the Windows Thread
1746 Information Block (TIB) structure. This structure is visible either
1747 by using the new command `info w32 thread-information-block' or, by
1748 dereferencing the new convenience variable named `$_tlb', a
1749 thread-specific pointer to the TIB. This feature is also supported
1750 when remote debugging using GDBserver.
1752 * Static tracepoints
1754 Static tracepoints are calls in the user program into a tracing
1755 library. One such library is a port of the LTTng kernel tracer to
1756 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1757 When debugging with GDBserver, GDB now supports combining the GDB
1758 tracepoint machinery with such libraries. For example: the user can
1759 use GDB to probe a static tracepoint marker (a call from the user
1760 program into the tracing library) with the new "strace" command (see
1761 "New commands" below). This creates a "static tracepoint" in the
1762 breakpoint list, that can be manipulated with the same feature set
1763 as fast and regular tracepoints. E.g., collect registers, local and
1764 global variables, collect trace state variables, and define
1765 tracepoint conditions. In addition, the user can collect extra
1766 static tracepoint marker specific data, by collecting the new
1767 $_sdata internal variable. When analyzing the trace buffer, you can
1768 inspect $_sdata like any other variable available to GDB. For more
1769 information, see the "Tracepoints" chapter in GDB user manual. New
1770 remote packets have been defined to support static tracepoints, see
1771 the "New remote packets" section below.
1773 * Better reconstruction of tracepoints after disconnected tracing
1775 GDB will attempt to download the original source form of tracepoint
1776 definitions when starting a trace run, and then will upload these
1777 upon reconnection to the target, resulting in a more accurate
1778 reconstruction of the tracepoints that are in use on the target.
1782 You can now exercise direct control over the ways that GDB can
1783 affect your program. For instance, you can disallow the setting of
1784 breakpoints, so that the program can run continuously (assuming
1785 non-stop mode). In addition, the "observer" variable is available
1786 to switch all of the different controls; in observer mode, GDB
1787 cannot affect the target's behavior at all, which is useful for
1788 tasks like diagnosing live systems in the field.
1790 * The new convenience variable $_thread holds the number of the
1793 * New remote packets
1797 Return the address of the Windows Thread Information Block of a given thread.
1801 In response to several of the tracepoint packets, the target may now
1802 also respond with a number of intermediate `qRelocInsn' request
1803 packets before the final result packet, to have GDB handle
1804 relocating an instruction to execute at a different address. This
1805 is particularly useful for stubs that support fast tracepoints. GDB
1806 reports support for this feature in the qSupported packet.
1810 List static tracepoint markers in the target program.
1814 List static tracepoint markers at a given address in the target
1817 qXfer:statictrace:read
1819 Read the static trace data collected (by a `collect $_sdata'
1820 tracepoint action). The remote stub reports support for this packet
1821 to gdb's qSupported query.
1825 Send the current settings of GDB's permission flags.
1829 Send part of the source (textual) form of a tracepoint definition,
1830 which includes location, conditional, and action list.
1832 * The source command now accepts a -s option to force searching for the
1833 script in the source search path even if the script name specifies
1836 * New features in the GDB remote stub, GDBserver
1838 - GDBserver now support tracepoints (including fast tracepoints, and
1839 static tracepoints). The feature is currently supported by the
1840 i386-linux and amd64-linux builds. See the "Tracepoints support
1841 in gdbserver" section in the manual for more information.
1843 GDBserver JIT compiles the tracepoint's conditional agent
1844 expression bytecode into native code whenever possible for low
1845 overhead dynamic tracepoints conditionals. For such tracepoints,
1846 an expression that examines program state is evaluated when the
1847 tracepoint is reached, in order to determine whether to capture
1848 trace data. If the condition is simple and false, processing the
1849 tracepoint finishes very quickly and no data is gathered.
1851 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1852 for static tracepoints support.
1854 - GDBserver now supports x86_64 Windows 64-bit debugging.
1856 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1857 it understands register description.
1859 * The --batch flag now disables pagination and queries.
1861 * X86 general purpose registers
1863 GDB now supports reading/writing byte, word and double-word x86
1864 general purpose registers directly. This means you can use, say,
1865 $ah or $ax to refer, respectively, to the byte register AH and
1866 16-bit word register AX that are actually portions of the 32-bit
1867 register EAX or 64-bit register RAX.
1869 * The `commands' command now accepts a range of breakpoints to modify.
1870 A plain `commands' following a command that creates multiple
1871 breakpoints affects all the breakpoints set by that command. This
1872 applies to breakpoints set by `rbreak', and also applies when a
1873 single `break' command creates multiple breakpoints (e.g.,
1874 breakpoints on overloaded c++ functions).
1876 * The `rbreak' command now accepts a filename specification as part of
1877 its argument, limiting the functions selected by the regex to those
1878 in the specified file.
1880 * Support for remote debugging Windows and SymbianOS shared libraries
1881 from Unix hosts has been improved. Non Windows GDB builds now can
1882 understand target reported file names that follow MS-DOS based file
1883 system semantics, such as file names that include drive letters and
1884 use the backslash character as directory separator. This makes it
1885 possible to transparently use the "set sysroot" and "set
1886 solib-search-path" on Unix hosts to point as host copies of the
1887 target's shared libraries. See the new command "set
1888 target-file-system-kind" described below, and the "Commands to
1889 specify files" section in the user manual for more information.
1893 eval template, expressions...
1894 Convert the values of one or more expressions under the control
1895 of the string template to a command line, and call it.
1897 set target-file-system-kind unix|dos-based|auto
1898 show target-file-system-kind
1899 Set or show the assumed file system kind for target reported file
1902 save breakpoints <filename>
1903 Save all current breakpoint definitions to a file suitable for use
1904 in a later debugging session. To read the saved breakpoint
1905 definitions, use the `source' command.
1907 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1910 info static-tracepoint-markers
1911 Display information about static tracepoint markers in the target.
1913 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1914 Define a static tracepoint by probing a marker at the given
1915 function, line, address, or marker ID.
1919 Enable and disable observer mode.
1921 set may-write-registers on|off
1922 set may-write-memory on|off
1923 set may-insert-breakpoints on|off
1924 set may-insert-tracepoints on|off
1925 set may-insert-fast-tracepoints on|off
1926 set may-interrupt on|off
1927 Set individual permissions for GDB effects on the target. Note that
1928 some of these settings can have undesirable or surprising
1929 consequences, particularly when changed in the middle of a session.
1930 For instance, disabling the writing of memory can prevent
1931 breakpoints from being inserted, cause single-stepping to fail, or
1932 even crash your program, if you disable after breakpoints have been
1933 inserted. However, GDB should not crash.
1935 set record memory-query on|off
1936 show record memory-query
1937 Control whether to stop the inferior if memory changes caused
1938 by an instruction cannot be recorded.
1943 The disassemble command now supports "start,+length" form of two arguments.
1947 ** GDB now provides a new directory location, called the python directory,
1948 where Python scripts written for GDB can be installed. The location
1949 of that directory is <data-directory>/python, where <data-directory>
1950 is the GDB data directory. For more details, see section `Scripting
1951 GDB using Python' in the manual.
1953 ** The GDB Python API now has access to breakpoints, symbols, symbol
1954 tables, program spaces, inferiors, threads and frame's code blocks.
1955 Additionally, GDB Parameters can now be created from the API, and
1956 manipulated via set/show in the CLI.
1958 ** New functions gdb.target_charset, gdb.target_wide_charset,
1959 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1961 ** New exception gdb.GdbError.
1963 ** Pretty-printers are now also looked up in the current program space.
1965 ** Pretty-printers can now be individually enabled and disabled.
1967 ** GDB now looks for names of Python scripts to auto-load in a
1968 special section named `.debug_gdb_scripts', in addition to looking
1969 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1971 * Tracepoint actions were unified with breakpoint commands. In particular,
1972 there are no longer differences in "info break" output for breakpoints and
1973 tracepoints and the "commands" command can be used for both tracepoints and
1974 regular breakpoints.
1978 ARM Symbian arm*-*-symbianelf*
1980 * D language support.
1981 GDB now supports debugging programs written in the D programming
1984 * GDB now supports the extended ptrace interface for PowerPC which is
1985 available since Linux kernel version 2.6.34. This automatically enables
1986 any hardware breakpoints and additional hardware watchpoints available in
1987 the processor. The old ptrace interface exposes just one hardware
1988 watchpoint and no hardware breakpoints.
1990 * GDB is now able to use the Data Value Compare (DVC) register available on
1991 embedded PowerPC processors to implement in hardware simple watchpoint
1992 conditions of the form:
1994 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1996 This works in native GDB running on Linux kernels with the extended ptrace
1997 interface mentioned above.
1999 *** Changes in GDB 7.1
2003 ** Namespace Support
2005 GDB now supports importing of namespaces in C++. This enables the
2006 user to inspect variables from imported namespaces. Support for
2007 namepace aliasing has also been added. So, if a namespace is
2008 aliased in the current scope (e.g. namepace C=A; ) the user can
2009 print variables using the alias (e.g. (gdb) print C::x).
2013 All known bugs relating to the printing of virtual base class were
2014 fixed. It is now possible to call overloaded static methods using a
2019 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2020 and reinterpret_cast<> are now handled by the C++ expression parser.
2024 Xilinx MicroBlaze microblaze-*-*
2029 Xilinx MicroBlaze microblaze
2032 * Multi-program debugging.
2034 GDB now has support for multi-program (a.k.a. multi-executable or
2035 multi-exec) debugging. This allows for debugging multiple inferiors
2036 simultaneously each running a different program under the same GDB
2037 session. See "Debugging Multiple Inferiors and Programs" in the
2038 manual for more information. This implied some user visible changes
2039 in the multi-inferior support. For example, "info inferiors" now
2040 lists inferiors that are not running yet or that have exited
2041 already. See also "New commands" and "New options" below.
2043 * New tracing features
2045 GDB's tracepoint facility now includes several new features:
2047 ** Trace state variables
2049 GDB tracepoints now include support for trace state variables, which
2050 are variables managed by the target agent during a tracing
2051 experiment. They are useful for tracepoints that trigger each
2052 other, so for instance one tracepoint can count hits in a variable,
2053 and then a second tracepoint has a condition that is true when the
2054 count reaches a particular value. Trace state variables share the
2055 $-syntax of GDB convenience variables, and can appear in both
2056 tracepoint actions and condition expressions. Use the "tvariable"
2057 command to create, and "info tvariables" to view; see "Trace State
2058 Variables" in the manual for more detail.
2062 GDB now includes an option for defining fast tracepoints, which
2063 targets may implement more efficiently, such as by installing a jump
2064 into the target agent rather than a trap instruction. The resulting
2065 speedup can be by two orders of magnitude or more, although the
2066 tradeoff is that some program locations on some target architectures
2067 might not allow fast tracepoint installation, for instance if the
2068 instruction to be replaced is shorter than the jump. To request a
2069 fast tracepoint, use the "ftrace" command, with syntax identical to
2070 the regular trace command.
2072 ** Disconnected tracing
2074 It is now possible to detach GDB from the target while it is running
2075 a trace experiment, then reconnect later to see how the experiment
2076 is going. In addition, a new variable disconnected-tracing lets you
2077 tell the target agent whether to continue running a trace if the
2078 connection is lost unexpectedly.
2082 GDB now has the ability to save the trace buffer into a file, and
2083 then use that file as a target, similarly to you can do with
2084 corefiles. You can select trace frames, print data that was
2085 collected in them, and use tstatus to display the state of the
2086 tracing run at the moment that it was saved. To create a trace
2087 file, use "tsave <filename>", and to use it, do "target tfile
2090 ** Circular trace buffer
2092 You can ask the target agent to handle the trace buffer as a
2093 circular buffer, discarding the oldest trace frames to make room for
2094 newer ones, by setting circular-trace-buffer to on. This feature may
2095 not be available for all target agents.
2100 The disassemble command, when invoked with two arguments, now requires
2101 the arguments to be comma-separated.
2104 The info variables command now displays variable definitions. Files
2105 which only declare a variable are not shown.
2108 The source command is now capable of sourcing Python scripts.
2109 This feature is dependent on the debugger being build with Python
2112 Related to this enhancement is also the introduction of a new command
2113 "set script-extension" (see below).
2115 * New commands (for set/show, see "New options" below)
2117 record save [<FILENAME>]
2118 Save a file (in core file format) containing the process record
2119 execution log for replay debugging at a later time.
2121 record restore <FILENAME>
2122 Restore the process record execution log that was saved at an
2123 earlier time, for replay debugging.
2125 add-inferior [-copies <N>] [-exec <FILENAME>]
2128 clone-inferior [-copies <N>] [ID]
2129 Make a new inferior ready to execute the same program another
2130 inferior has loaded.
2135 maint info program-spaces
2136 List the program spaces loaded into GDB.
2138 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2139 show remote interrupt-sequence
2140 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2141 as the sequence to the remote target in order to interrupt the execution.
2142 Ctrl-C is a default. Some system prefers BREAK which is high level of
2143 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2144 Magic SysRq g. It is BREAK signal and character 'g'.
2146 set remote interrupt-on-connect [on | off]
2147 show remote interrupt-on-connect
2148 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2149 remote target when gdb connects to it. This is needed when you debug
2152 set remotebreak [on | off]
2154 Deprecated. Use "set/show remote interrupt-sequence" instead.
2156 tvariable $NAME [ = EXP ]
2157 Create or modify a trace state variable.
2160 List trace state variables and their values.
2162 delete tvariable $NAME ...
2163 Delete one or more trace state variables.
2166 Evaluate the given expressions without collecting anything into the
2167 trace buffer. (Valid in tracepoint actions only.)
2169 ftrace FN / FILE:LINE / *ADDR
2170 Define a fast tracepoint at the given function, line, or address.
2172 * New expression syntax
2174 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2175 GDB now parses 0b101010 identically with 42.
2179 set follow-exec-mode new|same
2180 show follow-exec-mode
2181 Control whether GDB reuses the same inferior across an exec call or
2182 creates a new one. This is useful to be able to restart the old
2183 executable after the inferior having done an exec call.
2185 set default-collect EXPR, ...
2186 show default-collect
2187 Define a list of expressions to be collected at each tracepoint.
2188 This is a useful way to ensure essential items are not overlooked,
2189 such as registers or a critical global variable.
2191 set disconnected-tracing
2192 show disconnected-tracing
2193 If set to 1, the target is instructed to continue tracing if it
2194 loses its connection to GDB. If 0, the target is to stop tracing
2197 set circular-trace-buffer
2198 show circular-trace-buffer
2199 If set to on, the target is instructed to use a circular trace buffer
2200 and discard the oldest trace frames instead of stopping the trace due
2201 to a full trace buffer. If set to off, the trace stops when the buffer
2202 fills up. Some targets may not support this.
2204 set script-extension off|soft|strict
2205 show script-extension
2206 If set to "off", the debugger does not perform any script language
2207 recognition, and all sourced files are assumed to be GDB scripts.
2208 If set to "soft" (the default), files are sourced according to
2209 filename extension, falling back to GDB scripts if the first
2211 If set to "strict", files are sourced according to filename extension.
2213 set ada trust-PAD-over-XVS on|off
2214 show ada trust-PAD-over-XVS
2215 If off, activate a workaround against a bug in the debugging information
2216 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2217 the GCC sources for more information about the GNAT encoding and
2218 PAD types in particular). It is always safe to set this option to
2219 off, but this introduces a slight performance penalty. The default
2222 * Python API Improvements
2224 ** GDB provides the new class gdb.LazyString. This is useful in
2225 some pretty-printing cases. The new method gdb.Value.lazy_string
2226 provides a simple way to create objects of this type.
2228 ** The fields returned by gdb.Type.fields now have an
2229 `is_base_class' attribute.
2231 ** The new method gdb.Type.range returns the range of an array type.
2233 ** The new method gdb.parse_and_eval can be used to parse and
2234 evaluate an expression.
2236 * New remote packets
2239 Define a trace state variable.
2242 Get the current value of a trace state variable.
2245 Set desired tracing behavior upon disconnection.
2248 Set the trace buffer to be linear or circular.
2251 Get data about the tracepoints currently in use.
2255 Process record now works correctly with hardware watchpoints.
2257 Multiple bug fixes have been made to the mips-irix port, making it
2258 much more reliable. In particular:
2259 - Debugging threaded applications is now possible again. Previously,
2260 GDB would hang while starting the program, or while waiting for
2261 the program to stop at a breakpoint.
2262 - Attaching to a running process no longer hangs.
2263 - An error occurring while loading a core file has been fixed.
2264 - Changing the value of the PC register now works again. This fixes
2265 problems observed when using the "jump" command, or when calling
2266 a function from GDB, or even when assigning a new value to $pc.
2267 - With the "finish" and "return" commands, the return value for functions
2268 returning a small array is now correctly printed.
2269 - It is now possible to break on shared library code which gets executed
2270 during a shared library init phase (code executed while executing
2271 their .init section). Previously, the breakpoint would have no effect.
2272 - GDB is now able to backtrace through the signal handler for
2273 non-threaded programs.
2275 PIE (Position Independent Executable) programs debugging is now supported.
2276 This includes debugging execution of PIC (Position Independent Code) shared
2277 libraries although for that, it should be possible to run such libraries as an
2280 *** Changes in GDB 7.0
2282 * GDB now has an interface for JIT compilation. Applications that
2283 dynamically generate code can create symbol files in memory and register
2284 them with GDB. For users, the feature should work transparently, and
2285 for JIT developers, the interface is documented in the GDB manual in the
2286 "JIT Compilation Interface" chapter.
2288 * Tracepoints may now be conditional. The syntax is as for
2289 breakpoints; either an "if" clause appended to the "trace" command,
2290 or the "condition" command is available. GDB sends the condition to
2291 the target for evaluation using the same bytecode format as is used
2292 for tracepoint actions.
2294 * The disassemble command now supports: an optional /r modifier, print the
2295 raw instructions in hex as well as in symbolic form, and an optional /m
2296 modifier to print mixed source+assembly.
2298 * Process record and replay
2300 In a architecture environment that supports ``process record and
2301 replay'', ``process record and replay'' target can record a log of
2302 the process execution, and replay it with both forward and reverse
2305 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2306 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2307 set execution-direction {forward|reverse}, for targets that support
2310 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2311 feature is available with a native GDB running on kernel version
2314 * GDB now has support for multi-byte and wide character sets on the
2315 target. Strings whose character type is wchar_t, char16_t, or
2316 char32_t are now correctly printed. GDB supports wide- and unicode-
2317 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2318 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2319 `printf'. This feature requires iconv to work properly; if your
2320 system does not have a working iconv, GDB can use GNU libiconv. See
2321 the installation instructions for more information.
2323 * GDB now supports automatic retrieval of shared library files from
2324 remote targets. To use this feature, specify a system root that begins
2325 with the `remote:' prefix, either via the `set sysroot' command or via
2326 the `--with-sysroot' configure-time option.
2328 * "info sharedlibrary" now takes an optional regex of libraries to show,
2329 and it now reports if a shared library has no debugging information.
2331 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2332 now complete on file names.
2334 * When completing in expressions, gdb will attempt to limit
2335 completions to allowable structure or union fields, where appropriate.
2336 For instance, consider:
2338 # struct example { int f1; double f2; };
2339 # struct example variable;
2342 If the user types TAB at the end of this command line, the available
2343 completions will be "f1" and "f2".
2345 * Inlined functions are now supported. They show up in backtraces, and
2346 the "step", "next", and "finish" commands handle them automatically.
2348 * GDB now supports the token-splicing (##) and stringification (#)
2349 operators when expanding macros. It also supports variable-arity
2352 * GDB now supports inspecting extra signal information, exported by
2353 the new $_siginfo convenience variable. The feature is currently
2354 implemented on linux ARM, i386 and amd64.
2356 * GDB can now display the VFP floating point registers and NEON vector
2357 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2358 can provide these registers (requires Linux 2.6.30 or later). Remote
2359 and simulator targets may also provide them.
2361 * New remote packets
2364 Search memory for a sequence of bytes.
2367 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2368 operation over reliable transport links. Use of this packet is
2369 controlled by the `set remote noack-packet' command.
2372 Kill the process with the specified process ID. Use this in preference
2373 to `k' when multiprocess protocol extensions are supported.
2376 Obtains additional operating system information
2380 Read or write additional signal information.
2382 * Removed remote protocol undocumented extension
2384 An undocumented extension to the remote protocol's `S' stop reply
2385 packet that permited the stub to pass a process id was removed.
2386 Remote servers should use the `T' stop reply packet instead.
2388 * GDB now supports multiple function calling conventions according to the
2389 DWARF-2 DW_AT_calling_convention function attribute.
2391 * The SH target utilizes the aforementioned change to distinguish between gcc
2392 and Renesas calling convention. It also adds the new CLI commands
2393 `set/show sh calling-convention'.
2395 * GDB can now read compressed debug sections, as produced by GNU gold
2396 with the --compress-debug-sections=zlib flag.
2398 * 64-bit core files are now supported on AIX.
2400 * Thread switching is now supported on Tru64.
2402 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2403 which will be allocated using malloc later in program execution.
2405 * The qXfer:libraries:read remote procotol packet now allows passing a
2406 list of section offsets.
2408 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2409 conditions handling signals delivered during attach or thread creation
2410 have also been fixed.
2412 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2413 From the user's standpoint, all unqualified instances of True and False
2414 are treated as the standard definitions, regardless of context.
2416 * GDB now parses C++ symbol and type names more flexibly. For
2419 template<typename T> class C { };
2422 GDB will now correctly handle all of:
2424 ptype C<char const *>
2425 ptype C<char const*>
2426 ptype C<const char *>
2427 ptype C<const char*>
2429 * New features in the GDB remote stub, gdbserver
2431 - The "--wrapper" command-line argument tells gdbserver to use a
2432 wrapper program to launch programs for debugging.
2434 - On PowerPC and S/390 targets, it is now possible to use a single
2435 gdbserver executable to debug both 32-bit and 64-bit programs.
2436 (This requires gdbserver itself to be built as a 64-bit executable.)
2438 - gdbserver uses the new noack protocol mode for TCP connections to
2439 reduce communications latency, if also supported and enabled in GDB.
2441 - Support for the sparc64-linux-gnu target is now included in
2444 - The amd64-linux build of gdbserver now supports debugging both
2445 32-bit and 64-bit programs.
2447 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2448 now support hardware watchpoints, and will use them automatically
2453 GDB now has support for scripting using Python. Whether this is
2454 available is determined at configure time.
2456 New GDB commands can now be written in Python.
2458 * Ada tasking support
2460 Ada tasks can now be inspected in GDB. The following commands have
2464 Print the list of Ada tasks.
2466 Print detailed information about task number N.
2468 Print the task number of the current task.
2470 Switch the context of debugging to task number N.
2472 * Support for user-defined prefixed commands. The "define" command can
2473 add new commands to existing prefixes, e.g. "target".
2475 * Multi-inferior, multi-process debugging.
2477 GDB now has generalized support for multi-inferior debugging. See
2478 "Debugging Multiple Inferiors" in the manual for more information.
2479 Although availability still depends on target support, the command
2480 set is more uniform now. The GNU/Linux specific multi-forks support
2481 has been migrated to this new framework. This implied some user
2482 visible changes; see "New commands" and also "Removed commands"
2485 * Target descriptions can now describe the target OS ABI. See the
2486 "Target Description Format" section in the user manual for more
2489 * Target descriptions can now describe "compatible" architectures
2490 to indicate that the target can execute applications for a different
2491 architecture in addition to those for the main target architecture.
2492 See the "Target Description Format" section in the user manual for
2495 * Multi-architecture debugging.
2497 GDB now includes general supports for debugging applications on
2498 hybrid systems that use more than one single processor architecture
2499 at the same time. Each such hybrid architecture still requires
2500 specific support to be added. The only hybrid architecture supported
2501 in this version of GDB is the Cell Broadband Engine.
2503 * GDB now supports integrated debugging of Cell/B.E. applications that
2504 use both the PPU and SPU architectures. To enable support for hybrid
2505 Cell/B.E. debugging, you need to configure GDB to support both the
2506 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2507 --enable-targets configure option.
2509 * Non-stop mode debugging.
2511 For some targets, GDB now supports an optional mode of operation in
2512 which you can examine stopped threads while other threads continue
2513 to execute freely. This is referred to as non-stop mode, with the
2514 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2515 section in the user manual for more information.
2517 To be able to support remote non-stop debugging, a remote stub needs
2518 to implement the non-stop mode remote protocol extensions, as
2519 described in the "Remote Non-Stop" section of the user manual. The
2520 GDB remote stub, gdbserver, has been adjusted to support these
2521 extensions on linux targets.
2523 * New commands (for set/show, see "New options" below)
2525 catch syscall [NAME(S) | NUMBER(S)]
2526 Catch system calls. Arguments, which should be names of system
2527 calls or their numbers, mean catch only those syscalls. Without
2528 arguments, every syscall will be caught. When the inferior issues
2529 any of the specified syscalls, GDB will stop and announce the system
2530 call, both when it is called and when its call returns. This
2531 feature is currently available with a native GDB running on the
2532 Linux Kernel, under the following architectures: x86, x86_64,
2533 PowerPC and PowerPC64.
2535 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2537 Search memory for a sequence of bytes.
2539 maint set python print-stack
2540 maint show python print-stack
2541 Show a stack trace when an error is encountered in a Python script.
2544 Invoke CODE by passing it to the Python interpreter.
2549 These allow macros to be defined, undefined, and listed
2553 Show operating system information about processes.
2556 List the inferiors currently under GDB's control.
2559 Switch focus to inferior number NUM.
2562 Detach from inferior number NUM.
2565 Kill inferior number NUM.
2569 set spu stop-on-load
2570 show spu stop-on-load
2571 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2573 set spu auto-flush-cache
2574 show spu auto-flush-cache
2575 Control whether to automatically flush the software-managed cache
2576 during Cell/B.E. debugging.
2578 set sh calling-convention
2579 show sh calling-convention
2580 Control the calling convention used when calling SH target functions.
2583 show debug timestamp
2584 Control display of timestamps with GDB debugging output.
2586 set disassemble-next-line
2587 show disassemble-next-line
2588 Control display of disassembled source lines or instructions when
2591 set remote noack-packet
2592 show remote noack-packet
2593 Set/show the use of remote protocol QStartNoAckMode packet. See above
2594 under "New remote packets."
2596 set remote query-attached-packet
2597 show remote query-attached-packet
2598 Control use of remote protocol `qAttached' (query-attached) packet.
2600 set remote read-siginfo-object
2601 show remote read-siginfo-object
2602 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2605 set remote write-siginfo-object
2606 show remote write-siginfo-object
2607 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2610 set remote reverse-continue
2611 show remote reverse-continue
2612 Control use of remote protocol 'bc' (reverse-continue) packet.
2614 set remote reverse-step
2615 show remote reverse-step
2616 Control use of remote protocol 'bs' (reverse-step) packet.
2618 set displaced-stepping
2619 show displaced-stepping
2620 Control displaced stepping mode. Displaced stepping is a way to
2621 single-step over breakpoints without removing them from the debuggee.
2622 Also known as "out-of-line single-stepping".
2625 show debug displaced
2626 Control display of debugging info for displaced stepping.
2628 maint set internal-error
2629 maint show internal-error
2630 Control what GDB does when an internal error is detected.
2632 maint set internal-warning
2633 maint show internal-warning
2634 Control what GDB does when an internal warning is detected.
2639 Use a wrapper program to launch programs for debugging.
2641 set multiple-symbols (all|ask|cancel)
2642 show multiple-symbols
2643 The value of this variable can be changed to adjust the debugger behavior
2644 when an expression or a breakpoint location contains an ambiguous symbol
2645 name (an overloaded function name, for instance).
2647 set breakpoint always-inserted
2648 show breakpoint always-inserted
2649 Keep breakpoints always inserted in the target, as opposed to inserting
2650 them when resuming the target, and removing them when the target stops.
2651 This option can improve debugger performance on slow remote targets.
2653 set arm fallback-mode (arm|thumb|auto)
2654 show arm fallback-mode
2655 set arm force-mode (arm|thumb|auto)
2657 These commands control how ARM GDB determines whether instructions
2658 are ARM or Thumb. The default for both settings is auto, which uses
2659 the current CPSR value for instructions without symbols; previous
2660 versions of GDB behaved as if "set arm fallback-mode arm".
2662 set disable-randomization
2663 show disable-randomization
2664 Standalone programs run with the virtual address space randomization enabled
2665 by default on some platforms. This option keeps the addresses stable across
2666 multiple debugging sessions.
2670 Control whether other threads are stopped or not when some thread hits
2675 Requests that asynchronous execution is enabled in the target, if available.
2676 In this case, it's possible to resume target in the background, and interact
2677 with GDB while the target is running. "show target-async" displays the
2678 current state of asynchronous execution of the target.
2680 set target-wide-charset
2681 show target-wide-charset
2682 The target-wide-charset is the name of the character set that GDB
2683 uses when printing characters whose type is wchar_t.
2685 set tcp auto-retry (on|off)
2687 set tcp connect-timeout
2688 show tcp connect-timeout
2689 These commands allow GDB to retry failed TCP connections to a remote stub
2690 with a specified timeout period; this is useful if the stub is launched
2691 in parallel with GDB but may not be ready to accept connections immediately.
2693 set libthread-db-search-path
2694 show libthread-db-search-path
2695 Control list of directories which GDB will search for appropriate
2698 set schedule-multiple (on|off)
2699 show schedule-multiple
2700 Allow GDB to resume all threads of all processes or only threads of
2701 the current process.
2705 Use more aggressive caching for accesses to the stack. This improves
2706 performance of remote debugging (particularly backtraces) without
2707 affecting correctness.
2709 set interactive-mode (on|off|auto)
2710 show interactive-mode
2711 Control whether GDB runs in interactive mode (on) or not (off).
2712 When in interactive mode, GDB waits for the user to answer all
2713 queries. Otherwise, GDB does not wait and assumes the default
2714 answer. When set to auto (the default), GDB determines which
2715 mode to use based on the stdin settings.
2720 For program forks, this is replaced by the new more generic `info
2721 inferiors' command. To list checkpoints, you can still use the
2722 `info checkpoints' command, which was an alias for the `info forks'
2726 Replaced by the new `inferior' command. To switch between
2727 checkpoints, you can still use the `restart' command, which was an
2728 alias for the `fork' command.
2731 This is removed, since some targets don't have a notion of
2732 processes. To switch between processes, you can still use the
2733 `inferior' command using GDB's own inferior number.
2736 For program forks, this is replaced by the new more generic `kill
2737 inferior' command. To delete a checkpoint, you can still use the
2738 `delete checkpoint' command, which was an alias for the `delete
2742 For program forks, this is replaced by the new more generic `detach
2743 inferior' command. To detach a checkpoint, you can still use the
2744 `detach checkpoint' command, which was an alias for the `detach
2747 * New native configurations
2749 x86/x86_64 Darwin i[34567]86-*-darwin*
2751 x86_64 MinGW x86_64-*-mingw*
2755 Lattice Mico32 lm32-*
2756 x86 DICOS i[34567]86-*-dicos*
2757 x86_64 DICOS x86_64-*-dicos*
2760 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2761 (mingw32ce) debugging.
2767 These commands were actually not implemented on any target.
2769 *** Changes in GDB 6.8
2771 * New native configurations
2773 NetBSD/hppa hppa*-*netbsd*
2774 Xtensa GNU/Linux xtensa*-*-linux*
2778 NetBSD/hppa hppa*-*-netbsd*
2779 Xtensa GNU/Lunux xtensa*-*-linux*
2781 * Change in command line behavior -- corefiles vs. process ids.
2783 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2784 attaching to process NUMBER fails, GDB no longer attempts to open a
2785 core file named NUMBER. Attaching to a program using the -c option
2786 is no longer supported. Instead, use the '-p' or '--pid' options.
2788 * GDB can now be built as a native debugger for debugging Windows x86
2789 (mingw32) Portable Executable (PE) programs.
2791 * Pending breakpoints no longer change their number when their address
2794 * GDB now supports breakpoints with multiple locations,
2795 including breakpoints on C++ constructors, inside C++ templates,
2796 and in inlined functions.
2798 * GDB's ability to debug optimized code has been improved. GDB more
2799 accurately identifies function bodies and lexical blocks that occupy
2800 more than one contiguous range of addresses.
2802 * Target descriptions can now describe registers for PowerPC.
2804 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2805 registers on PowerPC targets.
2807 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2808 targets even when the libthread_db library is not available.
2810 * The GDB remote stub, gdbserver, now supports the new file transfer
2811 commands (remote put, remote get, and remote delete).
2813 * The GDB remote stub, gdbserver, now supports run and attach in
2814 extended-remote mode.
2816 * hppa*64*-*-hpux11* target broken
2817 The debugger is unable to start a program and fails with the following
2818 error: "Error trying to get information about dynamic linker".
2819 The gdb-6.7 release is also affected.
2821 * GDB now supports the --enable-targets= configure option to allow
2822 building a single GDB executable that supports multiple remote
2823 target architectures.
2825 * GDB now supports debugging C and C++ programs which use the
2826 Decimal Floating Point extension. In addition, the PowerPC target
2827 now has a set of pseudo-registers to inspect decimal float values
2828 stored in two consecutive float registers.
2830 * The -break-insert MI command can optionally create pending
2833 * Improved support for debugging Ada
2834 Many improvements to the Ada language support have been made. These
2836 - Better support for Ada2005 interface types
2837 - Improved handling of arrays and slices in general
2838 - Better support for Taft-amendment types
2839 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2841 - Improved command completion in Ada
2844 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2849 set print frame-arguments (all|scalars|none)
2850 show print frame-arguments
2851 The value of this variable can be changed to control which argument
2852 values should be printed by the debugger when displaying a frame.
2857 Transfer files to and from a remote target, and delete remote files.
2864 Transfer files to and from a remote target, and delete remote files.
2866 * New remote packets
2873 Open, close, read, write, and delete files on the remote system.
2876 Attach to an existing process on the remote system, in extended-remote
2880 Run a new process on the remote system, in extended-remote mode.
2882 *** Changes in GDB 6.7
2884 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2885 bfd, libiberty and opcodes, as revealed by static analysis donated by
2886 Coverity, Inc. (http://scan.coverity.com).
2888 * When looking up multiply-defined global symbols, GDB will now prefer the
2889 symbol definition in the current shared library if it was built using the
2890 -Bsymbolic linker option.
2892 * When the Text User Interface (TUI) is not configured, GDB will now
2893 recognize the -tui command-line option and print a message that the TUI
2896 * The GDB remote stub, gdbserver, now has lower overhead for high
2897 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2899 * GDB for MIPS targets now autodetects whether a remote target provides
2900 32-bit or 64-bit register values.
2902 * Support for C++ member pointers has been improved.
2904 * GDB now understands XML target descriptions, which specify the
2905 target's overall architecture. GDB can read a description from
2906 a local file or over the remote serial protocol.
2908 * Vectors of single-byte data use a new integer type which is not
2909 automatically displayed as character or string data.
2911 * The /s format now works with the print command. It displays
2912 arrays of single-byte integers and pointers to single-byte integers
2915 * Target descriptions can now describe target-specific registers,
2916 for architectures which have implemented the support (currently
2917 only ARM, M68K, and MIPS).
2919 * GDB and the GDB remote stub, gdbserver, now support the XScale
2922 * The GDB remote stub, gdbserver, has been updated to support
2923 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2924 has been rewritten to use the standard GDB remote protocol.
2926 * GDB can now step into C++ functions which are called through thunks.
2928 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2930 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2931 layout. It also supports a TextSeg= and DataSeg= response when only
2932 segment base addresses (rather than offsets) are available.
2934 * The /i format now outputs any trailing branch delay slot instructions
2935 immediately following the last instruction within the count specified.
2937 * The GDB remote protocol "T" stop reply packet now supports a
2938 "library" response. Combined with the new "qXfer:libraries:read"
2939 packet, this response allows GDB to debug shared libraries on targets
2940 where the operating system manages the list of loaded libraries (e.g.
2941 Windows and SymbianOS).
2943 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2944 (DLLs) on Windows and Windows CE targets.
2946 * GDB now supports a faster verification that a .debug file matches its binary
2947 according to its build-id signature, if the signature is present.
2953 Enable or disable hardware flow control (RTS/CTS) on the serial port
2954 when debugging using remote targets.
2956 set mem inaccessible-by-default
2957 show mem inaccessible-by-default
2958 If the target supplies a memory map, for instance via the remote
2959 protocol's "qXfer:memory-map:read" packet, setting this variable
2960 prevents GDB from accessing memory outside the memory map. This
2961 is useful for targets with memory mapped registers or which react
2962 badly to accesses of unmapped address space.
2964 set breakpoint auto-hw
2965 show breakpoint auto-hw
2966 If the target supplies a memory map, for instance via the remote
2967 protocol's "qXfer:memory-map:read" packet, setting this variable
2968 lets GDB use hardware breakpoints automatically for memory regions
2969 where it can not use software breakpoints. This covers both the
2970 "break" command and internal breakpoints used for other commands
2971 including "next" and "finish".
2974 catch exception unhandled
2975 Stop the program execution when Ada exceptions are raised.
2978 Stop the program execution when an Ada assertion failed.
2982 Set an alternate system root for target files. This is a more
2983 general version of "set solib-absolute-prefix", which is now
2984 an alias to "set sysroot".
2987 Provide extended SPU facility status information. This set of
2988 commands is available only when debugging the Cell/B.E. SPU
2991 * New native configurations
2993 OpenBSD/sh sh*-*openbsd*
2996 unset tdesc filename
2998 Use the specified local file as an XML target description, and do
2999 not query the target for its built-in description.
3003 OpenBSD/sh sh*-*-openbsd*
3004 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3005 Toshiba Media Processor mep-elf
3007 * New remote packets
3010 Ignore the specified signals; pass them directly to the debugged program
3011 without stopping other threads or reporting them to GDB.
3013 qXfer:features:read:
3014 Read an XML target description from the target, which describes its
3019 Read or write contents of an spufs file on the target system. These
3020 packets are available only on the Cell/B.E. SPU architecture.
3022 qXfer:libraries:read:
3023 Report the loaded shared libraries. Combined with new "T" packet
3024 response, this packet allows GDB to debug shared libraries on
3025 targets where the operating system manages the list of loaded
3026 libraries (e.g. Windows and SymbianOS).
3030 Support for these obsolete configurations has been removed.
3038 i[34567]86-*-lynxos*
3039 i[34567]86-*-netware*
3040 i[34567]86-*-sco3.2v5*
3041 i[34567]86-*-sco3.2v4*
3043 i[34567]86-*-sysv4.2*
3046 i[34567]86-*-unixware2*
3047 i[34567]86-*-unixware*
3056 * Other removed features
3063 Various m68k-only ROM monitors.
3070 Various Renesas ROM monitors and debugging interfaces for SH and
3075 Support for a Macraigor serial interface to on-chip debugging.
3076 GDB does not directly support the newer parallel or USB
3081 A debug information format. The predecessor to DWARF 2 and
3082 DWARF 3, which are still supported.
3084 Support for the HP aCC compiler on HP-UX/PA-RISC
3086 SOM-encapsulated symbolic debugging information, automatic
3087 invocation of pxdb, and the aCC custom C++ ABI. This does not
3088 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3089 with aCC can still be debugged on an assembly level.
3091 MIPS ".pdr" sections
3093 A MIPS-specific format used to describe stack frame layout
3094 in debugging information.
3098 GDB could work with an older version of Guile to debug
3099 the interpreter and Scheme programs running in it.
3101 set mips stack-arg-size
3102 set mips saved-gpreg-size
3104 Use "set mips abi" to control parameter passing for MIPS.
3106 *** Changes in GDB 6.6
3111 Cell Broadband Engine SPU spu-elf
3113 * GDB can now be configured as a cross-debugger targeting native Windows
3114 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3115 running on a Windows system over TCP/IP to debug Windows programs.
3117 * The GDB remote stub, gdbserver, has been updated to support Windows and
3118 Cygwin debugging. Both single-threaded and multi-threaded programs are
3121 * The "set trust-readonly-sections" command works again. This command was
3122 broken in GDB 6.3, 6.4, and 6.5.
3124 * The "load" command now supports writing to flash memory, if the remote
3125 stub provides the required support.
3127 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3128 longer requires symbolic debug information (e.g. DWARF-2).
3133 unset substitute-path
3134 show substitute-path
3135 Manage a list of substitution rules that GDB uses to rewrite the name
3136 of the directories where the sources are located. This can be useful
3137 for instance when the sources were moved to a different location
3138 between compilation and debugging.
3142 Print each CLI command as it is executed. Each command is prefixed with
3143 a number of `+' symbols representing the nesting depth.
3144 The source command now has a `-v' option to enable the same feature.
3148 The ARM Demon monitor support (RDP protocol, "target rdp").
3150 Kernel Object Display, an embedded debugging feature which only worked with
3151 an obsolete version of Cisco IOS.
3153 The 'set download-write-size' and 'show download-write-size' commands.
3155 * New remote packets
3158 Tell a stub about GDB client features, and request remote target features.
3159 The first feature implemented is PacketSize, which allows the target to
3160 specify the size of packets it can handle - to minimize the number of
3161 packets required and improve performance when connected to a remote
3165 Fetch an OS auxilliary vector from the remote stub. This packet is a
3166 more efficient replacement for qPart:auxv:read.
3168 qXfer:memory-map:read:
3169 Fetch a memory map from the remote stub, including information about
3170 RAM, ROM, and flash memory devices.
3175 Erase and program a flash memory device.
3177 * Removed remote packets
3180 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3181 used it, and only gdbserver implemented it.
3183 *** Changes in GDB 6.5
3187 Renesas M32C/M16C m32c-elf
3189 Morpho Technologies ms1 ms1-elf
3193 init-if-undefined Initialize a convenience variable, but
3194 only if it doesn't already have a value.
3196 The following commands are presently only implemented for native GNU/Linux:
3198 checkpoint Save a snapshot of the program state.
3200 restart <n> Return the program state to a
3201 previously saved state.
3203 info checkpoints List currently saved checkpoints.
3205 delete-checkpoint <n> Delete a previously saved checkpoint.
3207 set|show detach-on-fork Tell gdb whether to detach from a newly
3208 forked process, or to keep debugging it.
3210 info forks List forks of the user program that
3211 are available to be debugged.
3213 fork <n> Switch to debugging one of several
3214 forks of the user program that are
3215 available to be debugged.
3217 delete-fork <n> Delete a fork from the list of forks
3218 that are available to be debugged (and
3219 kill the forked process).
3221 detach-fork <n> Delete a fork from the list of forks
3222 that are available to be debugged (and
3223 allow the process to continue).
3227 Morpho Technologies ms2 ms1-elf
3229 * Improved Windows host support
3231 GDB now builds as a cross debugger hosted on i686-mingw32, including
3232 native console support, and remote communications using either
3233 network sockets or serial ports.
3235 * Improved Modula-2 language support
3237 GDB can now print most types in the Modula-2 syntax. This includes:
3238 basic types, set types, record types, enumerated types, range types,
3239 pointer types and ARRAY types. Procedure var parameters are correctly
3240 printed and hexadecimal addresses and character constants are also
3241 written in the Modula-2 syntax. Best results can be obtained by using
3242 GNU Modula-2 together with the -gdwarf-2 command line option.
3246 The ARM rdi-share module.
3248 The Netware NLM debug server.
3250 *** Changes in GDB 6.4
3252 * New native configurations
3254 OpenBSD/arm arm*-*-openbsd*
3255 OpenBSD/mips64 mips64-*-openbsd*
3259 Morpho Technologies ms1 ms1-elf
3261 * New command line options
3263 --batch-silent As for --batch, but totally silent.
3264 --return-child-result The debugger will exist with the same value
3265 the child (debugged) program exited with.
3266 --eval-command COMMAND, -ex COMMAND
3267 Execute a single GDB CLI command. This may be
3268 specified multiple times and in conjunction
3269 with the --command (-x) option.
3271 * Deprecated commands removed
3273 The following commands, that were deprecated in 2000, have been
3277 set|show arm disassembly-flavor set|show arm disassembler
3278 othernames set arm disassembler
3279 set|show remotedebug set|show debug remote
3280 set|show archdebug set|show debug arch
3281 set|show eventdebug set|show debug event
3284 * New BSD user-level threads support
3286 It is now possible to debug programs using the user-level threads
3287 library on OpenBSD and FreeBSD. Currently supported (target)
3290 FreeBSD/amd64 x86_64-*-freebsd*
3291 FreeBSD/i386 i386-*-freebsd*
3292 OpenBSD/i386 i386-*-openbsd*
3294 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3295 are not yet supported.
3297 * New support for Matsushita MN10300 w/sim added
3298 (Work in progress). mn10300-elf.
3300 * REMOVED configurations and files
3302 VxWorks and the XDR protocol *-*-vxworks
3303 Motorola MCORE mcore-*-*
3304 National Semiconductor NS32000 ns32k-*-*
3306 * New "set print array-indexes" command
3308 After turning this setting "on", GDB prints the index of each element
3309 when displaying arrays. The default is "off" to preserve the previous
3312 * VAX floating point support
3314 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3316 * User-defined command support
3318 In addition to using $arg0..$arg9 for argument passing, it is now possible
3319 to use $argc to determine now many arguments have been passed. See the
3320 section on user-defined commands in the user manual for more information.
3322 *** Changes in GDB 6.3:
3324 * New command line option
3326 GDB now accepts -l followed by a number to set the timeout for remote
3329 * GDB works with GCC -feliminate-dwarf2-dups
3331 GDB now supports a more compact representation of DWARF-2 debug
3332 information using DW_FORM_ref_addr references. These are produced
3333 by GCC with the option -feliminate-dwarf2-dups and also by some
3334 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3335 to use -feliminate-dwarf2-dups.
3337 * Internationalization
3339 When supported by the host system, GDB will be built with
3340 internationalization (libintl). The task of marking up the sources is
3341 continued, we're looking forward to our first translation.
3345 Initial support for debugging programs compiled with the GNAT
3346 implementation of the Ada programming language has been integrated
3347 into GDB. In this release, support is limited to expression evaluation.
3349 * New native configurations
3351 GNU/Linux/m32r m32r-*-linux-gnu
3355 GDB's remote protocol now includes support for the 'p' packet. This
3356 packet is used to fetch individual registers from a remote inferior.
3358 * END-OF-LIFE registers[] compatibility module
3360 GDB's internal register infrastructure has been completely rewritten.
3361 The new infrastructure making possible the implementation of key new
3362 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3365 GDB 6.3 will be the last release to include the the registers[]
3366 compatibility module that allowed out-of-date configurations to
3367 continue to work. This change directly impacts the following
3377 powerpc bdm protocol
3379 Unless there is activity to revive these configurations, they will be
3380 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3382 * OBSOLETE configurations and files
3384 Configurations that have been declared obsolete in this release have
3385 been commented out. Unless there is activity to revive these
3386 configurations, the next release of GDB will have their sources
3387 permanently REMOVED.
3396 *** Changes in GDB 6.2.1:
3398 * MIPS `break main; run' gave an heuristic-fence-post warning
3400 When attempting to run even a simple program, a warning about
3401 heuristic-fence-post being hit would be reported. This problem has
3404 * MIPS IRIX 'long double' crashed GDB
3406 When examining a long double variable, GDB would get a segmentation
3407 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3408 IRIX long double values).
3412 A bug in the VAX stack code was causing problems with the "next"
3413 command. This problem has been fixed.
3415 *** Changes in GDB 6.2:
3417 * Fix for ``many threads''
3419 On GNU/Linux systems that use the NPTL threads library, a program
3420 rapidly creating and deleting threads would confuse GDB leading to the
3423 ptrace: No such process.
3424 thread_db_get_info: cannot get thread info: generic error
3426 This problem has been fixed.
3428 * "-async" and "-noasync" options removed.
3430 Support for the broken "-noasync" option has been removed (it caused
3433 * New ``start'' command.
3435 This command runs the program until the begining of the main procedure.
3437 * New BSD Kernel Data Access Library (libkvm) interface
3439 Using ``target kvm'' it is now possible to debug kernel core dumps and
3440 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3441 platforms. Currently supported (native-only) configurations are:
3443 FreeBSD/amd64 x86_64-*-freebsd*
3444 FreeBSD/i386 i?86-*-freebsd*
3445 NetBSD/i386 i?86-*-netbsd*
3446 NetBSD/m68k m68*-*-netbsd*
3447 NetBSD/sparc sparc-*-netbsd*
3448 OpenBSD/amd64 x86_64-*-openbsd*
3449 OpenBSD/i386 i?86-*-openbsd*
3450 OpenBSD/m68k m68*-openbsd*
3451 OpenBSD/sparc sparc-*-openbsd*
3453 * Signal trampoline code overhauled
3455 Many generic problems with GDB's signal handling code have been fixed.
3456 These include: backtraces through non-contiguous stacks; recognition
3457 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3458 call; backtrace through a signal trampoline; step into and out of
3459 signal handlers; and single-stepping in the signal trampoline.
3461 Please note that kernel bugs are a limiting factor here. These
3462 features have been shown to work on an s390 GNU/Linux system that
3463 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3465 * Cygwin support for DWARF 2 added.
3467 * New native configurations
3469 GNU/Linux/hppa hppa*-*-linux*
3470 OpenBSD/hppa hppa*-*-openbsd*
3471 OpenBSD/m68k m68*-*-openbsd*
3472 OpenBSD/m88k m88*-*-openbsd*
3473 OpenBSD/powerpc powerpc-*-openbsd*
3474 NetBSD/vax vax-*-netbsd*
3475 OpenBSD/vax vax-*-openbsd*
3477 * END-OF-LIFE frame compatibility module
3479 GDB's internal frame infrastructure has been completely rewritten.
3480 The new infrastructure making it possible to support key new features
3481 including DWARF 2 Call Frame Information. To aid in the task of
3482 migrating old configurations to this new infrastructure, a
3483 compatibility module, that allowed old configurations to continue to
3484 work, was also included.
3486 GDB 6.2 will be the last release to include this frame compatibility
3487 module. This change directly impacts the following configurations:
3497 Unless there is activity to revive these configurations, they will be
3498 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3500 * REMOVED configurations and files
3502 Sun 3, running SunOS 3 m68*-*-sunos3*
3503 Sun 3, running SunOS 4 m68*-*-sunos4*
3504 Sun 2, running SunOS 3 m68000-*-sunos3*
3505 Sun 2, running SunOS 4 m68000-*-sunos4*
3506 Motorola 680x0 running LynxOS m68*-*-lynxos*
3507 AT&T 3b1/Unix pc m68*-att-*
3508 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3509 decstation mips-dec-* mips-little-*
3510 riscos mips-*-riscos* mips-*-sysv*
3511 sonymips mips-sony-*
3512 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3514 *** Changes in GDB 6.1.1:
3516 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3518 The TUI (Text-mode User Interface) is now built as part of a default
3519 GDB configuration. It is enabled by either selecting the TUI with the
3520 command line option "-i=tui" or by running the separate "gdbtui"
3521 program. For more information on the TUI, see the manual "Debugging
3524 * Pending breakpoint support (also included in GDB 6.1)
3526 Support has been added to allow you to specify breakpoints in shared
3527 libraries that have not yet been loaded. If a breakpoint location
3528 cannot be found, and the "breakpoint pending" option is set to auto,
3529 GDB queries you if you wish to make the breakpoint pending on a future
3530 shared-library load. If and when GDB resolves the breakpoint symbol,
3531 the pending breakpoint is removed as one or more regular breakpoints
3534 Pending breakpoints are very useful for GCJ Java debugging.
3536 * Fixed ISO-C build problems
3538 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3539 non ISO-C code that stopped them being built using a more strict ISO-C
3540 compiler (e.g., IBM's C compiler).
3542 * Fixed build problem on IRIX 5
3544 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3545 wasn't able to compile compile on an IRIX 5 system.
3547 * Added execute permission to gdb/gdbserver/configure
3549 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3550 permission. This bug would cause configure to fail on a number of
3551 systems (Solaris, IRIX). Ref: server/519.
3553 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3555 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3556 has been updated to use constant array sizes.
3558 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3560 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3561 its generated DWARF Call Frame Info. This encoding was causing GDB to
3562 panic, that panic has been fixed. Ref: gdb/1628.
3564 * Fixed a problem when examining parameters in shared library code.
3566 When examining parameters in optimized shared library code generated
3567 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3568 not available''. GDB now correctly displays the variable's value.
3570 *** Changes in GDB 6.1:
3572 * Removed --with-mmalloc
3574 Support for the mmalloc memory manager has been removed, as it
3575 conflicted with the internal gdb byte cache.
3577 * Changes in AMD64 configurations
3579 The AMD64 target now includes the %cs and %ss registers. As a result
3580 the AMD64 remote protocol has changed; this affects the floating-point
3581 and SSE registers. If you rely on those registers for your debugging,
3582 you should upgrade gdbserver on the remote side.
3584 * Revised SPARC target
3586 The SPARC target has been completely revised, incorporating the
3587 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3588 support for LynxOS and SunOS 4 has been dropped. Calling functions
3589 from within GDB on operating systems with a non-executable stack
3590 (Solaris, OpenBSD) now works.
3594 GDB has a new C++ demangler which does a better job on the mangled
3595 names generated by current versions of g++. It also runs faster, so
3596 with this and other changes gdb should now start faster on large C++
3599 * DWARF 2 Location Expressions
3601 GDB support for location expressions has been extended to support function
3602 arguments and frame bases. Older versions of GDB could crash when they
3605 * C++ nested types and namespaces
3607 GDB's support for nested types and namespaces in C++ has been
3608 improved, especially if you use the DWARF 2 debugging format. (This
3609 is the default for recent versions of GCC on most platforms.)
3610 Specifically, if you have a class "Inner" defined within a class or
3611 namespace "Outer", then GDB realizes that the class's name is
3612 "Outer::Inner", not simply "Inner". This should greatly reduce the
3613 frequency of complaints about not finding RTTI symbols. In addition,
3614 if you are stopped at inside of a function defined within a namespace,
3615 GDB modifies its name lookup accordingly.
3617 * New native configurations
3619 NetBSD/amd64 x86_64-*-netbsd*
3620 OpenBSD/amd64 x86_64-*-openbsd*
3621 OpenBSD/alpha alpha*-*-openbsd*
3622 OpenBSD/sparc sparc-*-openbsd*
3623 OpenBSD/sparc64 sparc64-*-openbsd*
3625 * New debugging protocols
3627 M32R with SDI protocol m32r-*-elf*
3629 * "set prompt-escape-char" command deleted.
3631 The command "set prompt-escape-char" has been deleted. This command,
3632 and its very obscure effet on GDB's prompt, was never documented,
3633 tested, nor mentioned in the NEWS file.
3635 * OBSOLETE configurations and files
3637 Configurations that have been declared obsolete in this release have
3638 been commented out. Unless there is activity to revive these
3639 configurations, the next release of GDB will have their sources
3640 permanently REMOVED.
3642 Sun 3, running SunOS 3 m68*-*-sunos3*
3643 Sun 3, running SunOS 4 m68*-*-sunos4*
3644 Sun 2, running SunOS 3 m68000-*-sunos3*
3645 Sun 2, running SunOS 4 m68000-*-sunos4*
3646 Motorola 680x0 running LynxOS m68*-*-lynxos*
3647 AT&T 3b1/Unix pc m68*-att-*
3648 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3649 decstation mips-dec-* mips-little-*
3650 riscos mips-*-riscos* mips-*-sysv*
3651 sonymips mips-sony-*
3652 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3654 * REMOVED configurations and files
3656 SGI Irix-4.x mips-sgi-irix4 or iris4
3657 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3658 Z8000 simulator z8k-zilog-none or z8ksim
3659 Matsushita MN10200 w/simulator mn10200-*-*
3660 H8/500 simulator h8500-hitachi-hms or h8500hms
3661 HP/PA running BSD hppa*-*-bsd*
3662 HP/PA running OSF/1 hppa*-*-osf*
3663 HP/PA Pro target hppa*-*-pro*
3664 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3665 386BSD i[3456]86-*-bsd*
3666 Sequent family i[3456]86-sequent-sysv4*
3667 i[3456]86-sequent-sysv*
3668 i[3456]86-sequent-bsd*
3669 SPARC running LynxOS sparc-*-lynxos*
3670 SPARC running SunOS 4 sparc-*-sunos4*
3671 Tsqware Sparclet sparclet-*-*
3672 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3674 *** Changes in GDB 6.0:
3678 Support for debugging the Objective-C programming language has been
3679 integrated into GDB.
3681 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3683 DWARF 2's Call Frame Information makes available compiler generated
3684 information that more exactly describes the program's run-time stack.
3685 By using this information, GDB is able to provide more robust stack
3688 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3689 have been updated to use a new backtrace mechanism which includes
3690 DWARF 2 CFI support.
3694 GDB's remote protocol has been extended to include support for hosted
3695 file I/O (where the remote target uses GDB's file system). See GDB's
3696 remote protocol documentation for details.
3698 * All targets using the new architecture framework.
3700 All of GDB's targets have been updated to use the new internal
3701 architecture framework. The way is now open for future GDB releases
3702 to include cross-architecture native debugging support (i386 on amd64,
3705 * GNU/Linux's Thread Local Storage (TLS)
3707 GDB now includes support for for the GNU/Linux implementation of
3708 per-thread variables.
3710 * GNU/Linux's Native POSIX Thread Library (NPTL)
3712 GDB's thread code has been updated to work with either the new
3713 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3715 * Separate debug info.
3717 GDB, in conjunction with BINUTILS, now supports a mechanism for
3718 automatically loading debug information from a separate file. Instead
3719 of shipping full debug and non-debug versions of system libraries,
3720 system integrators can now instead ship just the stripped libraries
3721 and optional debug files.
3723 * DWARF 2 Location Expressions
3725 DWARF 2 Location Expressions allow the compiler to more completely
3726 describe the location of variables (even in optimized code) to the
3729 GDB now includes preliminary support for location expressions (support
3730 for DW_OP_piece is still missing).
3734 A number of long standing bugs that caused GDB to die while starting a
3735 Java application have been fixed. GDB's Java support is now
3736 considered "useable".
3738 * GNU/Linux support for fork, vfork, and exec.
3740 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3741 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3744 * GDB supports logging output to a file
3746 There are two new commands, "set logging" and "show logging", which can be
3747 used to capture GDB's output to a file.
3749 * The meaning of "detach" has changed for gdbserver
3751 The "detach" command will now resume the application, as documented. To
3752 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3755 * d10v, m68hc11 `regs' command deprecated
3757 The `info registers' command has been updated so that it displays the
3758 registers using a format identical to the old `regs' command.
3762 A new command, "maint set profile on/off", has been added. This command can
3763 be used to enable or disable profiling while running GDB, to profile a
3764 session or a set of commands. In addition there is a new configure switch,
3765 "--enable-profiling", which will cause GDB to be compiled with profiling
3766 data, for more informative profiling results.
3768 * Default MI syntax changed to "mi2".
3770 The default MI (machine interface) syntax, enabled by the command line
3771 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3772 "mi1", can be enabled by specifying the option "-i=mi1".
3774 Support for the original "mi0" syntax (included in GDB 5.0) has been
3777 Fix for gdb/192: removed extraneous space when displaying frame level.
3778 Fix for gdb/672: update changelist is now output in mi list format.
3779 Fix for gdb/702: a -var-assign that updates the value now shows up
3780 in a subsequent -var-update.
3782 * New native configurations.
3784 FreeBSD/amd64 x86_64-*-freebsd*
3786 * Multi-arched targets.
3788 HP/PA HPUX11 hppa*-*-hpux*
3789 Renesas M32R/D w/simulator m32r-*-elf*
3791 * OBSOLETE configurations and files
3793 Configurations that have been declared obsolete in this release have
3794 been commented out. Unless there is activity to revive these
3795 configurations, the next release of GDB will have their sources
3796 permanently REMOVED.
3798 Z8000 simulator z8k-zilog-none or z8ksim
3799 Matsushita MN10200 w/simulator mn10200-*-*
3800 H8/500 simulator h8500-hitachi-hms or h8500hms
3801 HP/PA running BSD hppa*-*-bsd*
3802 HP/PA running OSF/1 hppa*-*-osf*
3803 HP/PA Pro target hppa*-*-pro*
3804 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3805 Sequent family i[3456]86-sequent-sysv4*
3806 i[3456]86-sequent-sysv*
3807 i[3456]86-sequent-bsd*
3808 Tsqware Sparclet sparclet-*-*
3809 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3811 * REMOVED configurations and files
3814 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3815 IBM AIX PS/2 i[3456]86-*-aix
3816 i386 running Mach 3.0 i[3456]86-*-mach3*
3817 i386 running Mach i[3456]86-*-mach*
3818 i386 running OSF/1 i[3456]86-*osf1mk*
3819 HP/Apollo 68k Family m68*-apollo*-sysv*,
3821 m68*-hp-bsd*, m68*-hp-hpux*
3822 Argonaut Risc Chip (ARC) arc-*-*
3823 Mitsubishi D30V d30v-*-*
3824 Fujitsu FR30 fr30-*-elf*
3825 OS/9000 i[34]86-*-os9k
3826 I960 with MON960 i960-*-coff
3828 * MIPS $fp behavior changed
3830 The convenience variable $fp, for the MIPS, now consistently returns
3831 the address of the current frame's base. Previously, depending on the
3832 context, $fp could refer to either $sp or the current frame's base
3833 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3834 The GNU Source-Level Debugger''.
3836 *** Changes in GDB 5.3:
3838 * GNU/Linux shared library multi-threaded performance improved.
3840 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3841 `/proc', in preference to `ptrace' for memory reads. This may result
3842 in an improvement in the start-up time of multi-threaded, shared
3843 library applications when run under GDB. One GDB user writes: ``loads
3844 shared libs like mad''.
3846 * ``gdbserver'' now supports multi-threaded applications on some targets
3848 Support for debugging multi-threaded applications which use
3849 the GNU/Linux LinuxThreads package has been added for
3850 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3851 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3853 * GDB now supports C/C++ preprocessor macros.
3855 GDB now expands preprocessor macro invocations in C/C++ expressions,
3856 and provides various commands for showing macro definitions and how
3859 The new command `macro expand EXPRESSION' expands any macro
3860 invocations in expression, and shows the result.
3862 The new command `show macro MACRO-NAME' shows the definition of the
3863 macro named MACRO-NAME, and where it was defined.
3865 Most compilers don't include information about macros in the debugging
3866 information by default. In GCC 3.1, for example, you need to compile
3867 your program with the options `-gdwarf-2 -g3'. If the macro
3868 information is present in the executable, GDB will read it.
3870 * Multi-arched targets.
3872 DEC Alpha (partial) alpha*-*-*
3873 DEC VAX (partial) vax-*-*
3875 National Semiconductor NS32000 (partial) ns32k-*-*
3876 Motorola 68000 (partial) m68k-*-*
3877 Motorola MCORE mcore-*-*
3881 Fujitsu FRV architecture added by Red Hat frv*-*-*
3884 * New native configurations
3886 Alpha NetBSD alpha*-*-netbsd*
3887 SH NetBSD sh*-*-netbsdelf*
3888 MIPS NetBSD mips*-*-netbsd*
3889 UltraSPARC NetBSD sparc64-*-netbsd*
3891 * OBSOLETE configurations and files
3893 Configurations that have been declared obsolete in this release have
3894 been commented out. Unless there is activity to revive these
3895 configurations, the next release of GDB will have their sources
3896 permanently REMOVED.
3898 Mitsubishi D30V d30v-*-*
3899 OS/9000 i[34]86-*-os9k
3900 IBM AIX PS/2 i[3456]86-*-aix
3901 Fujitsu FR30 fr30-*-elf*
3902 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3903 Argonaut Risc Chip (ARC) arc-*-*
3904 i386 running Mach 3.0 i[3456]86-*-mach3*
3905 i386 running Mach i[3456]86-*-mach*
3906 i386 running OSF/1 i[3456]86-*osf1mk*
3907 HP/Apollo 68k Family m68*-apollo*-sysv*,
3909 m68*-hp-bsd*, m68*-hp-hpux*
3910 I960 with MON960 i960-*-coff
3912 * OBSOLETE languages
3914 CHILL, a Pascal like language used by telecommunications companies.
3916 * REMOVED configurations and files
3918 AMD 29k family via UDI a29k-amd-udi, udi29k
3919 A29K VxWorks a29k-*-vxworks
3920 AMD 29000 embedded, using EBMON a29k-none-none
3921 AMD 29000 embedded with COFF a29k-none-coff
3922 AMD 29000 embedded with a.out a29k-none-aout
3924 testsuite/gdb.hp/gdb.threads-hp/ directory
3926 * New command "set max-user-call-depth <nnn>"
3928 This command allows the user to limit the call depth of user-defined
3929 commands. The default is 1024.
3931 * Changes in FreeBSD/i386 native debugging.
3933 Support for the "generate-core-file" has been added.
3935 * New commands "dump", "append", and "restore".
3937 These commands allow data to be copied from target memory
3938 to a bfd-format or binary file (dump and append), and back
3939 from a file into memory (restore).
3941 * Improved "next/step" support on multi-processor Alpha Tru64.
3943 The previous single-step mechanism could cause unpredictable problems,
3944 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3945 of a software single-step mechanism prevents this.
3947 *** Changes in GDB 5.2.1:
3955 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3956 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3957 Fix, by Joel Brobecker imported from mainline.
3959 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3960 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3961 Fix, by Fred Fish, imported from mainline.
3963 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3964 Surprisingly enough, it works now.
3965 By Michal Ludvig, imported from mainline.
3967 i386 hardware watchpoint support:
3968 avoid misses on second run for some targets.
3969 By Pierre Muller, imported from mainline.
3971 *** Changes in GDB 5.2:
3973 * New command "set trust-readonly-sections on[off]".
3975 This command is a hint that tells gdb that read-only sections
3976 really are read-only (ie. that their contents will not change).
3977 In this mode, gdb will go to the object file rather than the
3978 target to read memory from read-only sections (such as ".text").
3979 This can be a significant performance improvement on some
3980 (notably embedded) targets.
3982 * New command "generate-core-file" (or "gcore").
3984 This new gdb command allows the user to drop a core file of the child
3985 process state at any time. So far it's been implemented only for
3986 GNU/Linux and Solaris, but should be relatively easily ported to other
3987 hosts. Argument is core file name (defaults to core.<pid>).
3989 * New command line option
3991 GDB now accepts --pid or -p followed by a process id.
3993 * Change in command line behavior -- corefiles vs. process ids.
3995 There is a subtle behavior in the way in which GDB handles
3996 command line arguments. The first non-flag argument is always
3997 a program to debug, but the second non-flag argument may either
3998 be a corefile or a process id. Previously, GDB would attempt to
3999 open the second argument as a corefile, and if that failed, would
4000 issue a superfluous error message and then attempt to attach it as
4001 a process. Now, if the second argument begins with a non-digit,
4002 it will be treated as a corefile. If it begins with a digit,
4003 GDB will attempt to attach it as a process, and if no such process
4004 is found, will then attempt to open it as a corefile.
4006 * Changes in ARM configurations.
4008 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4009 configuration is fully multi-arch.
4011 * New native configurations
4013 ARM NetBSD arm*-*-netbsd*
4014 x86 OpenBSD i[3456]86-*-openbsd*
4015 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4016 Sparc64 running FreeBSD sparc64-*-freebsd*
4020 Sanyo XStormy16 xstormy16-elf
4022 * OBSOLETE configurations and files
4024 Configurations that have been declared obsolete in this release have
4025 been commented out. Unless there is activity to revive these
4026 configurations, the next release of GDB will have their sources
4027 permanently REMOVED.
4029 AMD 29k family via UDI a29k-amd-udi, udi29k
4030 A29K VxWorks a29k-*-vxworks
4031 AMD 29000 embedded, using EBMON a29k-none-none
4032 AMD 29000 embedded with COFF a29k-none-coff
4033 AMD 29000 embedded with a.out a29k-none-aout
4035 testsuite/gdb.hp/gdb.threads-hp/ directory
4037 * REMOVED configurations and files
4039 TI TMS320C80 tic80-*-*
4041 PowerPC Solaris powerpcle-*-solaris*
4042 PowerPC Windows NT powerpcle-*-cygwin32
4043 PowerPC Netware powerpc-*-netware*
4044 Harris/CXUX m88k m88*-harris-cxux*
4045 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4046 ns32k-utek-sysv* ns32k-utek-*
4047 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4048 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4049 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4050 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4051 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4053 * Changes to command line processing
4055 The new `--args' feature can be used to specify command-line arguments
4056 for the inferior from gdb's command line.
4058 * Changes to key bindings
4060 There is a new `operate-and-get-next' function bound to `C-o'.
4062 *** Changes in GDB 5.1.1
4064 Fix compile problem on DJGPP.
4066 Fix a problem with floating-point registers on the i386 being
4069 Fix to stop GDB crashing on .debug_str debug info.
4071 Numerous documentation fixes.
4073 Numerous testsuite fixes.
4075 *** Changes in GDB 5.1:
4077 * New native configurations
4079 Alpha FreeBSD alpha*-*-freebsd*
4080 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4081 MIPS GNU/Linux mips*-*-linux*
4082 MIPS SGI Irix 6.x mips*-sgi-irix6*
4083 ia64 AIX ia64-*-aix*
4084 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4088 Motorola 68HC11 and 68HC12 m68hc11-elf
4090 UltraSparc running GNU/Linux sparc64-*-linux*
4092 * OBSOLETE configurations and files
4094 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4095 Harris/CXUX m88k m88*-harris-cxux*
4096 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4097 ns32k-utek-sysv* ns32k-utek-*
4098 TI TMS320C80 tic80-*-*
4100 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4101 PowerPC Solaris powerpcle-*-solaris*
4102 PowerPC Windows NT powerpcle-*-cygwin32
4103 PowerPC Netware powerpc-*-netware*
4104 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
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 N/A
4109 stuff.c (Program to stuff files into a specially prepared space in kdb)
4110 kdb-start.c (Main loop for the standalone kernel debugger)
4112 Configurations that have been declared obsolete in this release have
4113 been commented out. Unless there is activity to revive these
4114 configurations, the next release of GDB will have their sources
4115 permanently REMOVED.
4117 * REMOVED configurations and files
4119 Altos 3068 m68*-altos-*
4120 Convex c1-*-*, c2-*-*
4122 ARM RISCix arm-*-* (as host)
4126 * GDB has been converted to ISO C.
4128 GDB's source code has been converted to ISO C. In particular, the
4129 sources are fully protoized, and rely on standard headers being
4134 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4136 * The MI enabled by default.
4138 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4139 revised and enabled by default. Packages which use GDB as a debugging
4140 engine behind a UI or another front end are encouraged to switch to
4141 using the GDB/MI interface, instead of the old annotations interface
4142 which is now deprecated.
4144 * Support for debugging Pascal programs.
4146 GDB now includes support for debugging Pascal programs. The following
4147 main features are supported:
4149 - Pascal-specific data types such as sets;
4151 - automatic recognition of Pascal sources based on file-name
4154 - Pascal-style display of data types, variables, and functions;
4156 - a Pascal expression parser.
4158 However, some important features are not yet supported.
4160 - Pascal string operations are not supported at all;
4162 - there are some problems with boolean types;
4164 - Pascal type hexadecimal constants are not supported
4165 because they conflict with the internal variables format;
4167 - support for Pascal objects and classes is not full yet;
4169 - unlike Pascal, GDB is case-sensitive for symbol names.
4171 * Changes in completion.
4173 Commands such as `shell', `run' and `set args', which pass arguments
4174 to inferior programs, now complete on file names, similar to what
4175 users expect at the shell prompt.
4177 Commands which accept locations, such as `disassemble', `print',
4178 `breakpoint', `until', etc. now complete on filenames as well as
4179 program symbols. Thus, if you type "break foob TAB", and the source
4180 files linked into the programs include `foobar.c', that file name will
4181 be one of the candidates for completion. However, file names are not
4182 considered for completion after you typed a colon that delimits a file
4183 name from a name of a function in that file, as in "break foo.c:bar".
4185 `set demangle-style' completes on available demangling styles.
4187 * New platform-independent commands:
4189 It is now possible to define a post-hook for a command as well as a
4190 hook that runs before the command. For more details, see the
4191 documentation of `hookpost' in the GDB manual.
4193 * Changes in GNU/Linux native debugging.
4195 Support for debugging multi-threaded programs has been completely
4196 revised for all platforms except m68k and sparc. You can now debug as
4197 many threads as your system allows you to have.
4199 Attach/detach is supported for multi-threaded programs.
4201 Support for SSE registers was added for x86. This doesn't work for
4202 multi-threaded programs though.
4204 * Changes in MIPS configurations.
4206 Multi-arch support is enabled for all MIPS configurations.
4208 GDB can now be built as native debugger on SGI Irix 6.x systems for
4209 debugging n32 executables. (Debugging 64-bit executables is not yet
4212 * Unified support for hardware watchpoints in all x86 configurations.
4214 Most (if not all) native x86 configurations support hardware-assisted
4215 breakpoints and watchpoints in a unified manner. This support
4216 implements debug register sharing between watchpoints, which allows to
4217 put a virtually infinite number of watchpoints on the same address,
4218 and also supports watching regions up to 16 bytes with several debug
4221 The new maintenance command `maintenance show-debug-regs' toggles
4222 debugging print-outs in functions that insert, remove, and test
4223 watchpoints and hardware breakpoints.
4225 * Changes in the DJGPP native configuration.
4227 New command ``info dos sysinfo'' displays assorted information about
4228 the CPU, OS, memory, and DPMI server.
4230 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4231 display information about segment descriptors stored in GDT, LDT, and
4234 New commands ``info dos pde'' and ``info dos pte'' display entries
4235 from Page Directory and Page Tables (for now works with CWSDPMI only).
4236 New command ``info dos address-pte'' displays the Page Table entry for
4237 a given linear address.
4239 GDB can now pass command lines longer than 126 characters to the
4240 program being debugged (requires an update to the libdbg.a library
4241 which is part of the DJGPP development kit).
4243 DWARF2 debug info is now supported.
4245 It is now possible to `step' and `next' through calls to `longjmp'.
4247 * Changes in documentation.
4249 All GDB documentation was converted to GFDL, the GNU Free
4250 Documentation License.
4252 Tracepoints-related commands are now fully documented in the GDB
4255 TUI, the Text-mode User Interface, is now documented in the manual.
4257 Tracepoints-related commands are now fully documented in the GDB
4260 The "GDB Internals" manual now has an index. It also includes
4261 documentation of `ui_out' functions, GDB coding standards, x86
4262 hardware watchpoints, and memory region attributes.
4264 * GDB's version number moved to ``version.in''
4266 The Makefile variable VERSION has been replaced by the file
4267 ``version.in''. People creating GDB distributions should update the
4268 contents of this file.
4272 GUD support is now a standard part of the EMACS distribution.
4274 *** Changes in GDB 5.0:
4276 * Improved support for debugging FP programs on x86 targets
4278 Unified and much-improved support for debugging floating-point
4279 programs on all x86 targets. In particular, ``info float'' now
4280 displays the FP registers in the same format on all x86 targets, with
4281 greater level of detail.
4283 * Improvements and bugfixes in hardware-assisted watchpoints
4285 It is now possible to watch array elements, struct members, and
4286 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4287 on x86 targets no longer erroneously trigger when the address is
4290 * Improvements in the native DJGPP version of GDB
4292 The distribution now includes all the scripts and auxiliary files
4293 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4294 machines ``out of the box''.
4296 The DJGPP version can now debug programs that use signals. It is
4297 possible to catch signals that happened in the debuggee, deliver
4298 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4299 would kill the program being debugged.) Programs that hook hardware
4300 interrupts (keyboard, timer, etc.) can also be debugged.
4302 It is now possible to debug DJGPP programs that redirect their
4303 standard handles or switch them to raw (as opposed to cooked) mode, or
4304 even close them. The command ``run < foo > bar'' works as expected,
4305 and ``info terminal'' reports useful information about the debuggee's
4306 terminal, including raw/cooked mode, redirection, etc.
4308 The DJGPP version now uses termios functions for console I/O, which
4309 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4312 DOS-style file names with drive letters are now fully supported by
4315 It is now possible to debug DJGPP programs that switch their working
4316 directory. It is also possible to rerun the debuggee any number of
4317 times without restarting GDB; thus, you can use the same setup,
4318 breakpoints, etc. for many debugging sessions.
4320 * New native configurations
4322 ARM GNU/Linux arm*-*-linux*
4323 PowerPC GNU/Linux powerpc-*-linux*
4327 Motorola MCore mcore-*-*
4328 x86 VxWorks i[3456]86-*-vxworks*
4329 PowerPC VxWorks powerpc-*-vxworks*
4330 TI TMS320C80 tic80-*-*
4332 * OBSOLETE configurations
4334 Altos 3068 m68*-altos-*
4335 Convex c1-*-*, c2-*-*
4337 ARM RISCix arm-*-* (as host)
4340 Configurations that have been declared obsolete will be commented out,
4341 but the code will be left in place. If there is no activity to revive
4342 these configurations before the next release of GDB, the sources will
4343 be permanently REMOVED.
4345 * Gould support removed
4347 Support for the Gould PowerNode and NP1 has been removed.
4349 * New features for SVR4
4351 On SVR4 native platforms (such as Solaris), if you attach to a process
4352 without first loading a symbol file, GDB will now attempt to locate and
4353 load symbols from the running process's executable file.
4355 * Many C++ enhancements
4357 C++ support has been greatly improved. Overload resolution now works properly
4358 in almost all cases. RTTI support is on the way.
4360 * Remote targets can connect to a sub-program
4362 A popen(3) style serial-device has been added. This device starts a
4363 sub-process (such as a stand-alone simulator) and then communicates
4364 with that. The sub-program to run is specified using the syntax
4365 ``|<program> <args>'' vis:
4367 (gdb) set remotedebug 1
4368 (gdb) target extended-remote |mn10300-elf-sim program-args
4370 * MIPS 64 remote protocol
4372 A long standing bug in the mips64 remote protocol where by GDB
4373 expected certain 32 bit registers (ex SR) to be transfered as 32
4374 instead of 64 bits has been fixed.
4376 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4377 added to provide backward compatibility with older versions of GDB.
4379 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4381 The command ``set remotebinarydownload'' command has been replaced by
4382 ``set remote X-packet''. Other commands in ``set remote'' family
4383 include ``set remote P-packet''.
4385 * Breakpoint commands accept ranges.
4387 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4388 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4389 ``tracepoint passcount'' also accepts a range of tracepoints.
4391 * ``apropos'' command added.
4393 The ``apropos'' command searches through command names and
4394 documentation strings, printing out matches, making it much easier to
4395 try to find a command that does what you are looking for.
4399 A new machine oriented interface (MI) has been added to GDB. This
4400 interface is designed for debug environments running GDB as a separate
4401 process. This is part of the long term libGDB project. See the
4402 "GDB/MI" chapter of the GDB manual for further information. It can be
4403 enabled by configuring with:
4405 .../configure --enable-gdbmi
4407 *** Changes in GDB-4.18:
4409 * New native configurations
4411 HP-UX 10.20 hppa*-*-hpux10.20
4412 HP-UX 11.x hppa*-*-hpux11.0*
4413 M68K GNU/Linux m68*-*-linux*
4417 Fujitsu FR30 fr30-*-elf*
4418 Intel StrongARM strongarm-*-*
4419 Mitsubishi D30V d30v-*-*
4421 * OBSOLETE configurations
4423 Gould PowerNode, NP1 np1-*-*, pn-*-*
4425 Configurations that have been declared obsolete will be commented out,
4426 but the code will be left in place. If there is no activity to revive
4427 these configurations before the next release of GDB, the sources will
4428 be permanently REMOVED.
4432 As a compatibility experiment, GDB's source files buildsym.h and
4433 buildsym.c have been converted to pure standard C, no longer
4434 containing any K&R compatibility code. We believe that all systems in
4435 use today either come with a standard C compiler, or have a GCC port
4436 available. If this is not true, please report the affected
4437 configuration to bug-gdb@gnu.org immediately. See the README file for
4438 information about getting a standard C compiler if you don't have one
4443 GDB now uses readline 2.2.
4445 * set extension-language
4447 You can now control the mapping between filename extensions and source
4448 languages by using the `set extension-language' command. For instance,
4449 you can ask GDB to treat .c files as C++ by saying
4450 set extension-language .c c++
4451 The command `info extensions' lists all of the recognized extensions
4452 and their associated languages.
4454 * Setting processor type for PowerPC and RS/6000
4456 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4457 you can use the `set processor' command to specify what variant of the
4458 PowerPC family you are debugging. The command
4462 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4463 following PowerPC and RS6000 variants:
4465 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4466 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4468 403GC IBM PowerPC 403GC
4469 505 Motorola PowerPC 505
4470 860 Motorola PowerPC 860 or 850
4471 601 Motorola PowerPC 601
4472 602 Motorola PowerPC 602
4473 603 Motorola/IBM PowerPC 603 or 603e
4474 604 Motorola PowerPC 604 or 604e
4475 750 Motorola/IBM PowerPC 750 or 750
4477 At the moment, this command just tells GDB what to name the
4478 special-purpose processor registers. Since almost all the affected
4479 registers are inaccessible to user-level programs, this command is
4480 only useful for remote debugging in its present form.
4484 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4485 more extensive support for HP-UX. Added features include shared
4486 library support, kernel threads and hardware watchpoints for 11.00,
4487 support for HP's ANSI C and C++ compilers, and a compatibility mode
4488 for xdb and dbx commands.
4492 HP's donation includes the new concept of catchpoints, which is a
4493 generalization of the old catch command. On HP-UX, it is now possible
4494 to catch exec, fork, and vfork, as well as library loading.
4496 This means that the existing catch command has changed; its first
4497 argument now specifies the type of catch to be set up. See the
4498 output of "help catch" for a list of catchpoint types.
4500 * Debugging across forks
4502 On HP-UX, you can choose which process to debug when a fork() happens
4507 HP has donated a curses-based terminal user interface (TUI). To get
4508 it, build with --enable-tui. Although this can be enabled for any
4509 configuration, at present it only works for native HP debugging.
4511 * GDB remote protocol additions
4513 A new protocol packet 'X' that writes binary data is now available.
4514 Default behavior is to try 'X', then drop back to 'M' if the stub
4515 fails to respond. The settable variable `remotebinarydownload'
4516 allows explicit control over the use of 'X'.
4518 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4519 full 64-bit address. The command
4521 set remoteaddresssize 32
4523 can be used to revert to the old behaviour. For existing remote stubs
4524 the change should not be noticed, as the additional address information
4527 In order to assist in debugging stubs, you may use the maintenance
4528 command `packet' to send any text string to the stub. For instance,
4530 maint packet heythere
4532 sends the packet "$heythere#<checksum>". Note that it is very easy to
4533 disrupt a debugging session by sending the wrong packet at the wrong
4536 The compare-sections command allows you to compare section data on the
4537 target to what is in the executable file without uploading or
4538 downloading, by comparing CRC checksums.
4540 * Tracing can collect general expressions
4542 You may now collect general expressions at tracepoints. This requires
4543 further additions to the target-side stub; see tracepoint.c and
4544 doc/agentexpr.texi for further details.
4546 * mask-address variable for Mips
4548 For Mips targets, you may control the zeroing of the upper 32 bits of
4549 a 64-bit address by entering `set mask-address on'. This is mainly
4550 of interest to users of embedded R4xxx and R5xxx processors.
4552 * Higher serial baud rates
4554 GDB's serial code now allows you to specify baud rates 57600, 115200,
4555 230400, and 460800 baud. (Note that your host system may not be able
4556 to achieve all of these rates.)
4560 The i960 configuration now includes an initial implementation of a
4561 builtin simulator, contributed by Jim Wilson.
4564 *** Changes in GDB-4.17:
4566 * New native configurations
4568 Alpha GNU/Linux alpha*-*-linux*
4569 Unixware 2.x i[3456]86-unixware2*
4570 Irix 6.x mips*-sgi-irix6*
4571 PowerPC GNU/Linux powerpc-*-linux*
4572 PowerPC Solaris powerpcle-*-solaris*
4573 Sparc GNU/Linux sparc-*-linux*
4574 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4578 Argonaut Risc Chip (ARC) arc-*-*
4579 Hitachi H8/300S h8300*-*-*
4580 Matsushita MN10200 w/simulator mn10200-*-*
4581 Matsushita MN10300 w/simulator mn10300-*-*
4582 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4583 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4584 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4585 Mitsubishi D10V w/simulator d10v-*-*
4586 Mitsubishi M32R/D w/simulator m32r-*-elf*
4587 Tsqware Sparclet sparclet-*-*
4588 NEC V850 w/simulator v850-*-*
4590 * New debugging protocols
4592 ARM with RDI protocol arm*-*-*
4593 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4594 DDB and LSI variants of PMON protocol mips*-*-*
4595 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4596 PowerPC with SDS protocol powerpc{,le}-*-eabi
4597 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4601 All configurations can now understand and use the DWARF 2 debugging
4602 format. The choice is automatic, if the symbol file contains DWARF 2
4607 GDB now includes basic Java language support. This support is
4608 only useful with Java compilers that produce native machine code.
4610 * solib-absolute-prefix and solib-search-path
4612 For SunOS and SVR4 shared libraries, you may now set the prefix for
4613 loading absolute shared library symbol files, and the search path for
4614 locating non-absolute shared library symbol files.
4616 * Live range splitting
4618 GDB can now effectively debug code for which GCC has performed live
4619 range splitting as part of its optimization. See gdb/doc/LRS for
4620 more details on the expected format of the stabs information.
4624 GDB's support for the GNU Hurd, including thread debugging, has been
4625 updated to work with current versions of the Hurd.
4629 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4630 instruction set. ARM GDB automatically detects when Thumb
4631 instructions are in use, and adjusts disassembly and backtracing
4636 GDB's MIPS target configurations now handle the MIP16 16-bit
4641 GDB now includes support for overlays; if an executable has been
4642 linked such that multiple sections are based at the same address, GDB
4643 will decide which section to use for symbolic info. You can choose to
4644 control the decision manually, using overlay commands, or implement
4645 additional target-side support and use "overlay load-target" to bring
4646 in the overlay mapping. Do "help overlay" for more detail.
4650 The command "info symbol <address>" displays information about
4651 the symbol at the specified address.
4655 The standard remote protocol now includes an extension that allows
4656 asynchronous collection and display of trace data. This requires
4657 extensive support in the target-side debugging stub. Tracing mode
4658 includes a new interaction mode in GDB and new commands: see the
4659 file tracepoint.c for more details.
4663 Configurations for embedded MIPS now include a simulator contributed
4664 by Cygnus Solutions. The simulator supports the instruction sets
4665 of most MIPS variants.
4669 Sparc configurations may now include the ERC32 simulator contributed
4670 by the European Space Agency. The simulator is not built into
4671 Sparc targets by default; configure with --enable-sim to include it.
4675 For target configurations that may include multiple variants of a
4676 basic architecture (such as MIPS and SH), you may now set the
4677 architecture explicitly. "set arch" sets, "info arch" lists
4678 the possible architectures.
4680 *** Changes in GDB-4.16:
4682 * New native configurations
4684 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4685 M68K NetBSD m68k-*-netbsd*
4686 PowerPC AIX 4.x powerpc-*-aix*
4687 PowerPC MacOS powerpc-*-macos*
4688 PowerPC Windows NT powerpcle-*-cygwin32
4689 RS/6000 AIX 4.x rs6000-*-aix4*
4693 ARM with RDP protocol arm-*-*
4694 I960 with MON960 i960-*-coff
4695 MIPS VxWorks mips*-*-vxworks*
4696 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4697 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4699 Matra Sparclet sparclet-*-*
4703 The powerpc-eabi configuration now includes the PSIM simulator,
4704 contributed by Andrew Cagney, with assistance from Mike Meissner.
4705 PSIM is a very elaborate model of the PowerPC, including not only
4706 basic instruction set execution, but also details of execution unit
4707 performance and I/O hardware. See sim/ppc/README for more details.
4711 GDB now works with Solaris 2.5.
4713 * Windows 95/NT native
4715 GDB will now work as a native debugger on Windows 95 and Windows NT.
4716 To build it from source, you must use the "gnu-win32" environment,
4717 which uses a DLL to emulate enough of Unix to run the GNU tools.
4718 Further information, binaries, and sources are available at
4719 ftp.cygnus.com, under pub/gnu-win32.
4721 * dont-repeat command
4723 If a user-defined command includes the command `dont-repeat', then the
4724 command will not be repeated if the user just types return. This is
4725 useful if the command is time-consuming to run, so that accidental
4726 extra keystrokes don't run the same command many times.
4728 * Send break instead of ^C
4730 The standard remote protocol now includes an option to send a break
4731 rather than a ^C to the target in order to interrupt it. By default,
4732 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4734 * Remote protocol timeout
4736 The standard remote protocol includes a new variable `remotetimeout'
4737 that allows you to set the number of seconds before GDB gives up trying
4738 to read from the target. The default value is 2.
4740 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4742 By default GDB will automatically keep track of objects as they are
4743 loaded and unloaded by the dynamic linker. By using the command `set
4744 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4745 when shared library events occur, thus allowing you to set breakpoints
4746 in shared libraries which are explicitly loaded by the inferior.
4748 Note this feature does not work on hpux8. On hpux9 you must link
4749 /usr/lib/end.o into your program. This feature should work
4750 automatically on hpux10.
4752 * Irix 5.x hardware watchpoint support
4754 Irix 5 configurations now support the use of hardware watchpoints.
4756 * Mips protocol "SYN garbage limit"
4758 When debugging a Mips target using the `target mips' protocol, you
4759 may set the number of characters that GDB will ignore by setting
4760 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4761 every character. The default value is 1050.
4763 * Recording and replaying remote debug sessions
4765 If you set `remotelogfile' to the name of a file, gdb will write to it
4766 a recording of a remote debug session. This recording may then be
4767 replayed back to gdb using "gdbreplay". See gdbserver/README for
4768 details. This is useful when you have a problem with GDB while doing
4769 remote debugging; you can make a recording of the session and send it
4770 to someone else, who can then recreate the problem.
4772 * Speedups for remote debugging
4774 GDB includes speedups for downloading and stepping MIPS systems using
4775 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4776 and more efficient S-record downloading.
4778 * Memory use reductions and statistics collection
4780 GDB now uses less memory and reports statistics about memory usage.
4781 Try the `maint print statistics' command, for example.
4783 *** Changes in GDB-4.15:
4785 * Psymtabs for XCOFF
4787 The symbol reader for AIX GDB now uses partial symbol tables. This
4788 can greatly improve startup time, especially for large executables.
4790 * Remote targets use caching
4792 Remote targets now use a data cache to speed up communication with the
4793 remote side. The data cache could lead to incorrect results because
4794 it doesn't know about volatile variables, thus making it impossible to
4795 debug targets which use memory mapped I/O devices. `set remotecache
4796 off' turns the the data cache off.
4798 * Remote targets may have threads
4800 The standard remote protocol now includes support for multiple threads
4801 in the target system, using new protocol commands 'H' and 'T'. See
4802 gdb/remote.c for details.
4806 If GDB is configured with `--enable-netrom', then it will include
4807 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4808 acts as though it is a bank of ROM on the target board, but you can
4809 write into it over the network. GDB's support consists only of
4810 support for fast loading into the emulated ROM; to debug, you must use
4811 another protocol, such as standard remote protocol. The usual
4812 sequence is something like
4814 target nrom <netrom-hostname>
4816 target remote <netrom-hostname>:1235
4820 GDB now includes support for the Apple Macintosh, as a host only. It
4821 may be run as either an MPW tool or as a standalone application, and
4822 it can debug through the serial port. All the usual GDB commands are
4823 available, but to the target command, you must supply "serial" as the
4824 device type instead of "/dev/ttyXX". See mpw-README in the main
4825 directory for more information on how to build. The MPW configuration
4826 scripts */mpw-config.in support only a few targets, and only the
4827 mips-idt-ecoff target has been tested.
4831 GDB configuration now uses autoconf. This is not user-visible,
4832 but does simplify configuration and building.
4836 GDB now supports hpux10.
4838 *** Changes in GDB-4.14:
4840 * New native configurations
4842 x86 FreeBSD i[345]86-*-freebsd
4843 x86 NetBSD i[345]86-*-netbsd
4844 NS32k NetBSD ns32k-*-netbsd
4845 Sparc NetBSD sparc-*-netbsd
4849 A29K VxWorks a29k-*-vxworks
4850 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4851 CPU32 EST-300 emulator m68*-*-est*
4852 PowerPC ELF powerpc-*-elf
4855 * Alpha OSF/1 support for procfs
4857 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4858 possible to attach to running processes. As the mounting of the /proc
4859 filesystem is optional on the Alpha, GDB automatically determines
4860 the availability of /proc during startup. This can lead to problems
4861 if /proc is unmounted after GDB has been started.
4863 * Arguments to user-defined commands
4865 User commands may accept up to 10 arguments separated by whitespace.
4866 Arguments are accessed within the user command via $arg0..$arg9. A
4869 print $arg0 + $arg1 + $arg2
4871 To execute the command use:
4874 Defines the command "adder" which prints the sum of its three arguments.
4875 Note the arguments are text substitutions, so they may reference variables,
4876 use complex expressions, or even perform inferior function calls.
4878 * New `if' and `while' commands
4880 This makes it possible to write more sophisticated user-defined
4881 commands. Both commands take a single argument, which is the
4882 expression to evaluate, and must be followed by the commands to
4883 execute, one per line, if the expression is nonzero, the list being
4884 terminated by the word `end'. The `if' command list may include an
4885 `else' word, which causes the following commands to be executed only
4886 if the expression is zero.
4888 * Fortran source language mode
4890 GDB now includes partial support for Fortran 77. It will recognize
4891 Fortran programs and can evaluate a subset of Fortran expressions, but
4892 variables and functions may not be handled correctly. GDB will work
4893 with G77, but does not yet know much about symbols emitted by other
4896 * Better HPUX support
4898 Most debugging facilities now work on dynamic executables for HPPAs
4899 running hpux9 or later. You can attach to running dynamically linked
4900 processes, but by default the dynamic libraries will be read-only, so
4901 for instance you won't be able to put breakpoints in them. To change
4902 that behavior do the following before running the program:
4908 This will cause the libraries to be mapped private and read-write.
4909 To revert to the normal behavior, do this:
4915 You cannot set breakpoints or examine data in the library until after
4916 the library is loaded if the function/data symbols do not have
4919 GDB can now also read debug symbols produced by the HP C compiler on
4920 HPPAs (sorry, no C++, Fortran or 68k support).
4922 * Target byte order now dynamically selectable
4924 You can choose which byte order to use with a target system, via the
4925 commands "set endian big" and "set endian little", and you can see the
4926 current setting by using "show endian". You can also give the command
4927 "set endian auto", in which case GDB will use the byte order
4928 associated with the executable. Currently, only embedded MIPS
4929 configurations support dynamic selection of target byte order.
4931 * New DOS host serial code
4933 This version uses DPMI interrupts to handle buffered I/O, so you
4934 no longer need to run asynctsr when debugging boards connected to
4937 *** Changes in GDB-4.13:
4939 * New "complete" command
4941 This lists all the possible completions for the rest of the line, if it
4942 were to be given as a command itself. This is intended for use by emacs.
4944 * Trailing space optional in prompt
4946 "set prompt" no longer adds a space for you after the prompt you set. This
4947 allows you to set a prompt which ends in a space or one that does not.
4949 * Breakpoint hit counts
4951 "info break" now displays a count of the number of times the breakpoint
4952 has been hit. This is especially useful in conjunction with "ignore"; you
4953 can ignore a large number of breakpoint hits, look at the breakpoint info
4954 to see how many times the breakpoint was hit, then run again, ignoring one
4955 less than that number, and this will get you quickly to the last hit of
4958 * Ability to stop printing at NULL character
4960 "set print null-stop" will cause GDB to stop printing the characters of
4961 an array when the first NULL is encountered. This is useful when large
4962 arrays actually contain only short strings.
4964 * Shared library breakpoints
4966 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4967 breakpoints in shared libraries before the executable is run.
4969 * Hardware watchpoints
4971 There is a new hardware breakpoint for the watch command for sparclite
4972 targets. See gdb/sparclite/hw_breakpoint.note.
4974 Hardware watchpoints are also now supported under GNU/Linux.
4978 Annotations have been added. These are for use with graphical interfaces,
4979 and are still experimental. Currently only gdba.el uses these.
4981 * Improved Irix 5 support
4983 GDB now works properly with Irix 5.2.
4985 * Improved HPPA support
4987 GDB now works properly with the latest GCC and GAS.
4989 * New native configurations
4991 Sequent PTX4 i[34]86-sequent-ptx4
4992 HPPA running OSF/1 hppa*-*-osf*
4993 Atari TT running SVR4 m68*-*-sysv4*
4994 RS/6000 LynxOS rs6000-*-lynxos*
4998 OS/9000 i[34]86-*-os9k
4999 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5002 * Hitachi SH7000 and E7000-PC ICE support
5004 There is now support for communicating with the Hitachi E7000-PC ICE.
5005 This is available automatically when GDB is configured for the SH.
5009 As usual, a variety of small fixes and improvements, both generic
5010 and configuration-specific. See the ChangeLog for more detail.
5012 *** Changes in GDB-4.12:
5014 * Irix 5 is now supported
5018 GDB-4.12 on the HPPA has a number of changes which make it unable
5019 to debug the output from the currently released versions of GCC and
5020 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5021 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5022 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5025 *** Changes in GDB-4.11:
5027 * User visible changes:
5031 The "set remotedebug" option is now consistent between the mips remote
5032 target, remote targets using the gdb-specific protocol, UDI (AMD's
5033 debug protocol for the 29k) and the 88k bug monitor. It is now an
5034 integer specifying a debug level (normally 0 or 1, but 2 means more
5035 debugging info for the mips target).
5037 * DEC Alpha native support
5039 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5040 debug info, but GDB works fairly well with the DEC compiler and should
5041 work with a future GCC release. See the README file for a few
5042 Alpha-specific notes.
5044 * Preliminary thread implementation
5046 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5048 * LynxOS native and target support for 386
5050 This release has been hosted on LynxOS 2.2, and also can be configured
5051 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5054 * Improvements in C++ mangling/demangling.
5056 This release has much better g++ debugging, specifically in name
5057 mangling/demangling, virtual function calls, print virtual table,
5058 call methods, ...etc.
5060 *** Changes in GDB-4.10:
5062 * User visible changes:
5064 Remote debugging using the GDB-specific (`target remote') protocol now
5065 supports the `load' command. This is only useful if you have some
5066 other way of getting the stub to the target system, and you can put it
5067 somewhere in memory where it won't get clobbered by the download.
5069 Filename completion now works.
5071 When run under emacs mode, the "info line" command now causes the
5072 arrow to point to the line specified. Also, "info line" prints
5073 addresses in symbolic form (as well as hex).
5075 All vxworks based targets now support a user settable option, called
5076 vxworks-timeout. This option represents the number of seconds gdb
5077 should wait for responses to rpc's. You might want to use this if
5078 your vxworks target is, perhaps, a slow software simulator or happens
5079 to be on the far side of a thin network line.
5083 This release contains support for using a DEC alpha as a GDB host for
5084 cross debugging. Native alpha debugging is not supported yet.
5087 *** Changes in GDB-4.9:
5091 This is the first GDB release which is accompanied by a matching testsuite.
5092 The testsuite requires installation of dejagnu, which should be available
5093 via ftp from most sites that carry GNU software.
5097 'Cfront' style demangling has had its name changed to 'ARM' style, to
5098 emphasize that it was written from the specifications in the C++ Annotated
5099 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5100 disclaimers, it still generated too much confusion with users attempting to
5101 use gdb with AT&T cfront.
5105 GDB now uses a standard remote interface to a simulator library.
5106 So far, the library contains simulators for the Zilog Z8001/2, the
5107 Hitachi H8/300, H8/500 and Super-H.
5109 * New targets supported
5111 H8/300 simulator h8300-hitachi-hms or h8300hms
5112 H8/500 simulator h8500-hitachi-hms or h8500hms
5113 SH simulator sh-hitachi-hms or sh
5114 Z8000 simulator z8k-zilog-none or z8ksim
5115 IDT MIPS board over serial line mips-idt-ecoff
5117 Cross-debugging to GO32 targets is supported. It requires a custom
5118 version of the i386-stub.c module which is integrated with the
5119 GO32 memory extender.
5121 * New remote protocols
5123 MIPS remote debugging protocol.
5125 * New source languages supported
5127 This version includes preliminary support for Chill, a Pascal like language
5128 used by telecommunications companies. Chill support is also being integrated
5129 into the GNU compiler, but we don't know when it will be publically available.
5132 *** Changes in GDB-4.8:
5134 * HP Precision Architecture supported
5136 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5137 version of this support was available as a set of patches from the
5138 University of Utah. GDB does not support debugging of programs
5139 compiled with the HP compiler, because HP will not document their file
5140 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5141 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5143 Many problems in the preliminary version have been fixed.
5145 * Faster and better demangling
5147 We have improved template demangling and fixed numerous bugs in the GNU style
5148 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5149 character types (wchar_t) are now supported. Demangling of each symbol is now
5150 only done once, and is cached when the symbol table for a file is read in.
5151 This results in a small increase in memory usage for C programs, a moderate
5152 increase in memory usage for C++ programs, and a fantastic speedup in
5155 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5156 from the specifications in the Annotated Reference Manual, which AT&T's
5157 compiler does not actually implement.
5159 * G++ multiple inheritance compiler problem
5161 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5162 inheritance lattices was reworked to properly discover ambiguities. We
5163 recently found an example which causes this new algorithm to fail in a
5164 very subtle way, producing bad debug information for those classes.
5165 The file 'gcc.patch' (in this directory) can be applied to gcc to
5166 circumvent the problem. A future GCC release will contain a complete
5169 The previous G++ debug info problem (mentioned below for the gdb-4.7
5170 release) is fixed in gcc version 2.3.2.
5172 * Improved configure script
5174 The `configure' script will now attempt to guess your system type if
5175 you don't supply a host system type. The old scheme of supplying a
5176 host system triplet is preferable over using this. All the magic is
5177 done in the new `config.guess' script. Examine it for details.
5179 We have also brought our configure script much more in line with the FSF's
5180 version. It now supports the --with-xxx options. In particular,
5181 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5182 The resulting GDB will not be able to read arbitrary object file formats --
5183 only the format ``expected'' to be used on the configured target system.
5184 We hope to make this the default in a future release.
5186 * Documentation improvements
5188 There's new internal documentation on how to modify GDB, and how to
5189 produce clean changes to the code. We implore people to read it
5190 before submitting changes.
5192 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5193 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5194 `info' files are also provided. To build `info' files from scratch,
5195 you will need the latest `makeinfo' release, which will be available in
5196 a future texinfo-X.Y release.
5198 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5199 We're not sure exactly which versions have this problem, but it has
5200 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5201 or better. If that isn't possible, there is a patch in
5202 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5203 around this problem.
5207 GDB now supports array constants that can be used in expressions typed in by
5208 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5209 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5212 The new directory `gdb/sparclite' contains a program that demonstrates
5213 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5215 * New native hosts supported
5217 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5218 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5220 * New targets supported
5222 AMD 29k family via UDI a29k-amd-udi or udi29k
5224 * New file formats supported
5226 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5227 HPUX core files, and SCO 3.2v2 core files.
5231 Attaching to processes now works again; thanks for the many bug reports.
5233 We have also stomped on a bunch of core dumps caused by
5234 printf_filtered("%s") problems.
5236 We eliminated a copyright problem on the rpc and ptrace header files
5237 for VxWorks, which was discovered at the last minute during the 4.7
5238 release. You should now be able to build a VxWorks GDB.
5240 You can now interrupt gdb while an attached process is running. This
5241 will cause the attached process to stop, and give control back to GDB.
5243 We fixed problems caused by using too many file descriptors
5244 for reading symbols from object files and libraries. This was
5245 especially a problem for programs that used many (~100) shared
5248 The `step' command now only enters a subroutine if there is line number
5249 information for the subroutine. Otherwise it acts like the `next'
5250 command. Previously, `step' would enter subroutines if there was
5251 any debugging information about the routine. This avoids problems
5252 when using `cc -g1' on MIPS machines.
5254 * Internal improvements
5256 GDB's internal interfaces have been improved to make it easier to support
5257 debugging of multiple languages in the future.
5259 GDB now uses a common structure for symbol information internally.
5260 Minimal symbols (derived from linkage symbols in object files), partial
5261 symbols (from a quick scan of debug information), and full symbols
5262 contain a common subset of information, making it easier to write
5263 shared code that handles any of them.
5265 * New command line options
5267 We now accept --silent as an alias for --quiet.
5271 The memory-mapped-malloc library is now licensed under the GNU Library
5272 General Public License.
5274 *** Changes in GDB-4.7:
5276 * Host/native/target split
5278 GDB has had some major internal surgery to untangle the support for
5279 hosts and remote targets. Now, when you configure GDB for a remote
5280 target, it will no longer load in all of the support for debugging
5281 local programs on the host. When fully completed and tested, this will
5282 ensure that arbitrary host/target combinations are possible.
5284 The primary conceptual shift is to separate the non-portable code in
5285 GDB into three categories. Host specific code is required any time GDB
5286 is compiled on that host, regardless of the target. Target specific
5287 code relates to the peculiarities of the target, but can be compiled on
5288 any host. Native specific code is everything else: it can only be
5289 built when the host and target are the same system. Child process
5290 handling and core file support are two common `native' examples.
5292 GDB's use of /proc for controlling Unix child processes is now cleaner.
5293 It has been split out into a single module under the `target_ops' vector,
5294 plus two native-dependent functions for each system that uses /proc.
5296 * New hosts supported
5298 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5299 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5300 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5302 * New targets supported
5304 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5305 68030 and CPU32 m68030-*-*, m68332-*-*
5307 * New native hosts supported
5309 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5310 (386bsd is not well tested yet)
5311 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5313 * New file formats supported
5315 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5316 supports reading of `a.out.adobe' object files, which are an a.out
5317 format extended with minimal information about multiple sections.
5321 `show copying' is the same as the old `info copying'.
5322 `show warranty' is the same as `info warrantee'.
5323 These were renamed for consistency. The old commands continue to work.
5325 `info handle' is a new alias for `info signals'.
5327 You can now define pre-command hooks, which attach arbitrary command
5328 scripts to any command. The commands in the hook will be executed
5329 prior to the user's command. You can also create a hook which will be
5330 executed whenever the program stops. See gdb.texinfo.
5334 We now deal with Cfront style name mangling, and can even extract type
5335 info from mangled symbols. GDB can automatically figure out which
5336 symbol mangling style your C++ compiler uses.
5338 Calling of methods and virtual functions has been improved as well.
5342 The crash that occured when debugging Sun Ansi-C compiled binaries is
5343 fixed. This was due to mishandling of the extra N_SO stabs output
5346 We also finally got Ultrix 4.2 running in house, and fixed core file
5347 support, with help from a dozen people on the net.
5349 John M. Farrell discovered that the reason that single-stepping was so
5350 slow on all of the Mips based platforms (primarily SGI and DEC) was
5351 that we were trying to demangle and lookup a symbol used for internal
5352 purposes on every instruction that was being stepped through. Changing
5353 the name of that symbol so that it couldn't be mistaken for a C++
5354 mangled symbol sped things up a great deal.
5356 Rich Pixley sped up symbol lookups in general by getting much smarter
5357 about when C++ symbol mangling is necessary. This should make symbol
5358 completion (TAB on the command line) much faster. It's not as fast as
5359 we'd like, but it's significantly faster than gdb-4.6.
5363 A new user controllable variable 'call_scratch_address' can
5364 specify the location of a scratch area to be used when GDB
5365 calls a function in the target. This is necessary because the
5366 usual method of putting the scratch area on the stack does not work
5367 in systems that have separate instruction and data spaces.
5369 We integrated changes to support the 29k UDI (Universal Debugger
5370 Interface), but discovered at the last minute that we didn't have all
5371 of the appropriate copyright paperwork. We are working with AMD to
5372 resolve this, and hope to have it available soon.
5376 We have sped up the remote serial line protocol, especially for targets
5377 with lots of registers. It now supports a new `expedited status' ('T')
5378 message which can be used in place of the existing 'S' status message.
5379 This allows the remote stub to send only the registers that GDB
5380 needs to make a quick decision about single-stepping or conditional
5381 breakpoints, eliminating the need to fetch the entire register set for
5382 each instruction being stepped through.
5384 The GDB remote serial protocol now implements a write-through cache for
5385 registers, only re-reading the registers if the target has run.
5387 There is also a new remote serial stub for SPARC processors. You can
5388 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5389 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5390 processor with a serial port.
5394 Configure.in files have become much easier to read and modify. A new
5395 `table driven' format makes it more obvious what configurations are
5396 supported, and what files each one uses.
5400 There is a new opcodes library which will eventually contain all of the
5401 disassembly routines and opcode tables. At present, it only contains
5402 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5403 disassembler (binutils/objdump) to share these routines.
5405 The libiberty library is now copylefted under the GNU Library General
5406 Public License. This allows more liberal use, and was done so libg++
5407 can use it. This makes no difference to GDB, since the Library License
5408 grants all the rights from the General Public License.
5412 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5413 reference to the stabs symbol info used by the debugger. It is (as far
5414 as we know) the only published document on this fascinating topic. We
5415 encourage you to read it, compare it to the stabs information on your
5416 system, and send improvements on the document in general (to
5417 bug-gdb@prep.ai.mit.edu).
5419 And, of course, many bugs have been fixed.
5422 *** Changes in GDB-4.6:
5424 * Better support for C++ function names
5426 GDB now accepts as input the "demangled form" of C++ overloaded function
5427 names and member function names, and can do command completion on such names
5428 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5429 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5430 Make use of command completion, it is your friend.
5432 GDB also now accepts a variety of C++ mangled symbol formats. They are
5433 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5434 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5435 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5436 for the list of formats.
5438 * G++ symbol mangling problem
5440 Recent versions of gcc have a bug in how they emit debugging information for
5441 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5442 directory) can be applied to gcc to fix the problem. Alternatively, if you
5443 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5444 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5445 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5448 * New 'maintenance' command
5450 All of the commands related to hacking GDB internals have been moved out of
5451 the main command set, and now live behind the 'maintenance' command. This
5452 can also be abbreviated as 'mt'. The following changes were made:
5454 dump-me -> maintenance dump-me
5455 info all-breakpoints -> maintenance info breakpoints
5456 printmsyms -> maintenance print msyms
5457 printobjfiles -> maintenance print objfiles
5458 printpsyms -> maintenance print psymbols
5459 printsyms -> maintenance print symbols
5461 The following commands are new:
5463 maintenance demangle Call internal GDB demangler routine to
5464 demangle a C++ link name and prints the result.
5465 maintenance print type Print a type chain for a given symbol
5467 * Change to .gdbinit file processing
5469 We now read the $HOME/.gdbinit file before processing the argv arguments
5470 (e.g. reading symbol files or core files). This allows global parameters to
5471 be set, which will apply during the symbol reading. The ./.gdbinit is still
5472 read after argv processing.
5474 * New hosts supported
5476 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5478 GNU/Linux support i386-unknown-linux or linux
5480 We are also including code to support the HP/PA running BSD and HPUX. This
5481 is almost guaranteed not to work, as we didn't have time to test or build it
5482 for this release. We are including it so that the more adventurous (or
5483 masochistic) of you can play with it. We also had major problems with the
5484 fact that the compiler that we got from HP doesn't support the -g option.
5487 * New targets supported
5489 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5491 * More smarts about finding #include files
5493 GDB now remembers the compilation directory for all include files, and for
5494 all files from which C is generated (like yacc and lex sources). This
5495 greatly improves GDB's ability to find yacc/lex sources, and include files,
5496 especially if you are debugging your program from a directory different from
5497 the one that contains your sources.
5499 We also fixed a bug which caused difficulty with listing and setting
5500 breakpoints in include files which contain C code. (In the past, you had to
5501 try twice in order to list an include file that you hadn't looked at before.)
5503 * Interesting infernals change
5505 GDB now deals with arbitrary numbers of sections, where the symbols for each
5506 section must be relocated relative to that section's landing place in the
5507 target's address space. This work was needed to support ELF with embedded
5508 stabs used by Solaris-2.0.
5510 * Bug fixes (of course!)
5512 There have been loads of fixes for the following things:
5513 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5514 i960, stabs, DOS(GO32), procfs, etc...
5516 See the ChangeLog for details.
5518 *** Changes in GDB-4.5:
5520 * New machines supported (host and target)
5522 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5524 SGI Irix-4.x mips-sgi-irix4 or iris4
5526 * New malloc package
5528 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5529 Mmalloc is capable of handling mutiple heaps of memory. It is also
5530 capable of saving a heap to a file, and then mapping it back in later.
5531 This can be used to greatly speedup the startup of GDB by using a
5532 pre-parsed symbol table which lives in a mmalloc managed heap. For
5533 more details, please read mmalloc/mmalloc.texi.
5537 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5538 'help info proc' for details.
5540 * MIPS ecoff symbol table format
5542 The code that reads MIPS symbol table format is now supported on all hosts.
5543 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5546 * File name changes for MS-DOS
5548 Many files in the config directories have been renamed to make it easier to
5549 support GDB on MS-DOSe systems (which have very restrictive file name
5550 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5551 environment) is close to working but has some remaining problems. Note
5552 that debugging of DOS programs is not supported, due to limitations
5553 in the ``operating system'', but it can be used to host cross-debugging.
5555 * Cross byte order fixes
5557 Many fixes have been made to support cross debugging of Sparc and MIPS
5558 targets from hosts whose byte order differs.
5560 * New -mapped and -readnow options
5562 If memory-mapped files are available on your system through the 'mmap'
5563 system call, you can use the -mapped option on the `file' or
5564 `symbol-file' commands to cause GDB to write the symbols from your
5565 program into a reusable file. If the program you are debugging is
5566 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5567 Future GDB debugging sessions will notice the presence of this file,
5568 and will quickly map in symbol information from it, rather than reading
5569 the symbol table from the executable program. Using the '-mapped'
5570 option in a GDB `file' or `symbol-file' command has the same effect as
5571 starting GDB with the '-mapped' command-line option.
5573 You can cause GDB to read the entire symbol table immediately by using
5574 the '-readnow' option with any of the commands that load symbol table
5575 information (or on the GDB command line). This makes the command
5576 slower, but makes future operations faster.
5578 The -mapped and -readnow options are typically combined in order to
5579 build a `fred.syms' file that contains complete symbol information.
5580 A simple GDB invocation to do nothing but build a `.syms' file for future
5583 gdb -batch -nx -mapped -readnow programname
5585 The `.syms' file is specific to the host machine on which GDB is run.
5586 It holds an exact image of GDB's internal symbol table. It cannot be
5587 shared across multiple host platforms.
5589 * longjmp() handling
5591 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5592 siglongjmp() without losing control. This feature has not yet been ported to
5593 all systems. It currently works on many 386 platforms, all MIPS-based
5594 platforms (SGI, DECstation, etc), and Sun3/4.
5598 Preliminary work has been put in to support the new Solaris OS from Sun. At
5599 this time, it can control and debug processes, but it is not capable of
5604 As always, many many bug fixes. The major areas were with g++, and mipsread.
5605 People using the MIPS-based platforms should experience fewer mysterious
5606 crashes and trashed symbol tables.
5608 *** Changes in GDB-4.4:
5610 * New machines supported (host and target)
5612 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5614 BSD Reno on Vax vax-dec-bsd
5615 Ultrix on Vax vax-dec-ultrix
5617 * New machines supported (target)
5619 AMD 29000 embedded, using EBMON a29k-none-none
5623 GDB continues to improve its handling of C++. `References' work better.
5624 The demangler has also been improved, and now deals with symbols mangled as
5625 per the Annotated C++ Reference Guide.
5627 GDB also now handles `stabs' symbol information embedded in MIPS
5628 `ecoff' symbol tables. Since the ecoff format was not easily
5629 extensible to handle new languages such as C++, this appeared to be a
5630 good way to put C++ debugging info into MIPS binaries. This option
5631 will be supported in the GNU C compiler, version 2, when it is
5634 * New features for SVR4
5636 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5637 shared libraries. Debugging dynamically linked programs should present
5638 only minor differences from debugging statically linked programs.
5640 The `info proc' command will print out information about any process
5641 on an SVR4 system (including the one you are debugging). At the moment,
5642 it prints the address mappings of the process.
5644 If you bring up GDB on another SVR4 system, please send mail to
5645 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5647 * Better dynamic linking support in SunOS
5649 Reading symbols from shared libraries which contain debugging symbols
5650 now works properly. However, there remain issues such as automatic
5651 skipping of `transfer vector' code during function calls, which
5652 make it harder to debug code in a shared library, than to debug the
5653 same code linked statically.
5657 GDB is now using the latest `getopt' routines from the FSF. This
5658 version accepts the -- prefix for options with long names. GDB will
5659 continue to accept the old forms (-option and +option) as well.
5660 Various single letter abbreviations for options have been explicity
5661 added to the option table so that they won't get overshadowed in the
5662 future by other options that begin with the same letter.
5666 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5667 Many assorted bugs have been handled. Many more remain to be handled.
5668 See the various ChangeLog files (primarily in gdb and bfd) for details.
5671 *** Changes in GDB-4.3:
5673 * New machines supported (host and target)
5675 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5676 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5677 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5679 * Almost SCO Unix support
5681 We had hoped to support:
5682 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5683 (except for core file support), but we discovered very late in the release
5684 that it has problems with process groups that render gdb unusable. Sorry
5685 about that. I encourage people to fix it and post the fixes.
5687 * Preliminary ELF and DWARF support
5689 GDB can read ELF object files on System V Release 4, and can handle
5690 debugging records for C, in DWARF format, in ELF files. This support
5691 is preliminary. If you bring up GDB on another SVR4 system, please
5692 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5697 GDB now uses the latest `readline' library. One user-visible change
5698 is that two tabs will list possible command completions, which previously
5699 required typing M-? (meta-question mark, or ESC ?).
5703 The `stepi' bug that many of you noticed has been squashed.
5704 Many bugs in C++ have been handled. Many more remain to be handled.
5705 See the various ChangeLog files (primarily in gdb and bfd) for details.
5707 * State of the MIPS world (in case you wondered):
5709 GDB can understand the symbol tables emitted by the compilers
5710 supplied by most vendors of MIPS-based machines, including DEC. These
5711 symbol tables are in a format that essentially nobody else uses.
5713 Some versions of gcc come with an assembler post-processor called
5714 mips-tfile. This program is required if you want to do source-level
5715 debugging of gcc-compiled programs. I believe FSF does not ship
5716 mips-tfile with gcc version 1, but it will eventually come with gcc
5719 Debugging of g++ output remains a problem. g++ version 1.xx does not
5720 really support it at all. (If you're lucky, you should be able to get
5721 line numbers and stack traces to work, but no parameters or local
5722 variables.) With some work it should be possible to improve the
5725 When gcc version 2 is released, you will have somewhat better luck.
5726 However, even then you will get confusing results for inheritance and
5729 We will eventually provide full debugging of g++ output on
5730 DECstations. This will probably involve some kind of stabs-in-ecoff
5731 encapulation, but the details have not been worked out yet.
5734 *** Changes in GDB-4.2:
5736 * Improved configuration
5738 Only one copy of `configure' exists now, and it is not self-modifying.
5739 Porting BFD is simpler.
5743 The `step' and `next' commands now only stop at the first instruction
5744 of a source line. This prevents the multiple stops that used to occur
5745 in switch statements, for-loops, etc. `Step' continues to stop if a
5746 function that has debugging information is called within the line.
5750 Lots of small bugs fixed. More remain.
5752 * New host supported (not target)
5754 Intel 386 PC clone running Mach i386-none-mach
5757 *** Changes in GDB-4.1:
5759 * Multiple source language support
5761 GDB now has internal scaffolding to handle several source languages.
5762 It determines the type of each source file from its filename extension,
5763 and will switch expression parsing and number formatting to match the
5764 language of the function in the currently selected stack frame.
5765 You can also specifically set the language to be used, with
5766 `set language c' or `set language modula-2'.
5770 GDB now has preliminary support for the GNU Modula-2 compiler,
5771 currently under development at the State University of New York at
5772 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5773 continue through the fall of 1991 and into 1992.
5775 Other Modula-2 compilers are currently not supported, and attempting to
5776 debug programs compiled with them will likely result in an error as the
5777 symbol table is read. Feel free to work on it, though!
5779 There are hooks in GDB for strict type checking and range checking,
5780 in the `Modula-2 philosophy', but they do not currently work.
5784 GDB can now write to executable and core files (e.g. patch
5785 a variable's value). You must turn this switch on, specify
5786 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5787 by assigning a new value to a variable. Modifications take
5790 * Automatic SunOS shared library reading
5792 When you run your program, GDB automatically determines where its
5793 shared libraries (if any) have been loaded, and reads their symbols.
5794 The `share' command is no longer needed. This also works when
5795 examining core files.
5799 You can specify the number of lines that the `list' command shows.
5802 * New machines supported (host and target)
5804 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5805 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5806 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5808 * New hosts supported (not targets)
5810 IBM RT/PC: romp-ibm-aix or rtpc
5812 * New targets supported (not hosts)
5814 AMD 29000 embedded with COFF a29k-none-coff
5815 AMD 29000 embedded with a.out a29k-none-aout
5816 Ultracomputer remote kernel debug a29k-nyu-kern
5818 * New remote interfaces
5824 *** Changes in GDB-4.0:
5828 Wide output is wrapped at good places to make the output more readable.
5830 Gdb now supports cross-debugging from a host machine of one type to a
5831 target machine of another type. Communication with the target system
5832 is over serial lines. The ``target'' command handles connecting to the
5833 remote system; the ``load'' command will download a program into the
5834 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5835 also supports debugging of realtime processes running under VxWorks,
5836 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5837 stub on the target system.
5839 New CPUs supported include the AMD 29000 and Intel 960.
5841 GDB now reads object files and symbol tables via a ``binary file''
5842 library, which allows a single copy of GDB to debug programs of multiple
5843 object file types such as a.out and coff.
5845 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5846 refcard.dvi and refcard.ps are available to format it).
5849 * Control-Variable user interface simplified
5851 All variables that control the operation of the debugger can be set
5852 by the ``set'' command, and displayed by the ``show'' command.
5854 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5855 ``Show prompt'' produces the response:
5856 Gdb's prompt is new-gdb=>.
5858 What follows are the NEW set commands. The command ``help set'' will
5859 print a complete list of old and new set commands. ``help set FOO''
5860 will give a longer description of the variable FOO. ``show'' will show
5861 all of the variable descriptions and their current settings.
5863 confirm on/off: Enables warning questions for operations that are
5864 hard to recover from, e.g. rerunning the program while
5865 it is already running. Default is ON.
5867 editing on/off: Enables EMACS style command line editing
5868 of input. Previous lines can be recalled with
5869 control-P, the current line can be edited with control-B,
5870 you can search for commands with control-R, etc.
5873 history filename NAME: NAME is where the gdb command history
5874 will be stored. The default is .gdb_history,
5875 or the value of the environment variable
5878 history size N: The size, in commands, of the command history. The
5879 default is 256, or the value of the environment variable
5882 history save on/off: If this value is set to ON, the history file will
5883 be saved after exiting gdb. If set to OFF, the
5884 file will not be saved. The default is OFF.
5886 history expansion on/off: If this value is set to ON, then csh-like
5887 history expansion will be performed on
5888 command line input. The default is OFF.
5890 radix N: Sets the default radix for input and output. It can be set
5891 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5892 in the current radix, so "set radix 10" is always a no-op.
5894 height N: This integer value is the number of lines on a page. Default
5895 is 24, the current `stty rows'' setting, or the ``li#''
5896 setting from the termcap entry matching the environment
5899 width N: This integer value is the number of characters on a line.
5900 Default is 80, the current `stty cols'' setting, or the ``co#''
5901 setting from the termcap entry matching the environment
5904 Note: ``set screensize'' is obsolete. Use ``set height'' and
5905 ``set width'' instead.
5907 print address on/off: Print memory addresses in various command displays,
5908 such as stack traces and structure values. Gdb looks
5909 more ``symbolic'' if you turn this off; it looks more
5910 ``machine level'' with it on. Default is ON.
5912 print array on/off: Prettyprint arrays. New convenient format! Default
5915 print demangle on/off: Print C++ symbols in "source" form if on,
5918 print asm-demangle on/off: Same, for assembler level printouts
5921 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5924 * Support for Epoch Environment.
5926 The epoch environment is a version of Emacs v18 with windowing. One
5927 new command, ``inspect'', is identical to ``print'', except that if you
5928 are running in the epoch environment, the value is printed in its own
5932 * Support for Shared Libraries
5934 GDB can now debug programs and core files that use SunOS shared libraries.
5935 Symbols from a shared library cannot be referenced
5936 before the shared library has been linked with the program (this
5937 happens after you type ``run'' and before the function main() is entered).
5938 At any time after this linking (including when examining core files
5939 from dynamically linked programs), gdb reads the symbols from each
5940 shared library when you type the ``sharedlibrary'' command.
5941 It can be abbreviated ``share''.
5943 sharedlibrary REGEXP: Load shared object library symbols for files
5944 matching a unix regular expression. No argument
5945 indicates to load symbols for all shared libraries.
5947 info sharedlibrary: Status of loaded shared libraries.
5952 A watchpoint stops execution of a program whenever the value of an
5953 expression changes. Checking for this slows down execution
5954 tremendously whenever you are in the scope of the expression, but is
5955 quite useful for catching tough ``bit-spreader'' or pointer misuse
5956 problems. Some machines such as the 386 have hardware for doing this
5957 more quickly, and future versions of gdb will use this hardware.
5959 watch EXP: Set a watchpoint (breakpoint) for an expression.
5961 info watchpoints: Information about your watchpoints.
5963 delete N: Deletes watchpoint number N (same as breakpoints).
5964 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5965 enable N: Re-enables watchpoint number N (same as breakpoints).
5968 * C++ multiple inheritance
5970 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5973 * C++ exception handling
5975 Gdb now supports limited C++ exception handling. Besides the existing
5976 ability to breakpoint on an exception handler, gdb can breakpoint on
5977 the raising of an exception (before the stack is peeled back to the
5980 catch FOO: If there is a FOO exception handler in the dynamic scope,
5981 set a breakpoint to catch exceptions which may be raised there.
5982 Multiple exceptions (``catch foo bar baz'') may be caught.
5984 info catch: Lists all exceptions which may be caught in the
5985 current stack frame.
5988 * Minor command changes
5990 The command ``call func (arg, arg, ...)'' now acts like the print
5991 command, except it does not print or save a value if the function's result
5992 is void. This is similar to dbx usage.
5994 The ``up'' and ``down'' commands now always print the frame they end up
5995 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5996 frames without printing.
5998 * New directory command
6000 'dir' now adds directories to the FRONT of the source search path.
6001 The path starts off empty. Source files that contain debug information
6002 about the directory in which they were compiled can be found even
6003 with an empty path; Sun CC and GCC include this information. If GDB can't
6004 find your source file in the current directory, type "dir .".
6006 * Configuring GDB for compilation
6008 For normal use, type ``./configure host''. See README or gdb.texinfo
6011 GDB now handles cross debugging. If you are remotely debugging between
6012 two different machines, type ``./configure host -target=targ''.
6013 Host is the machine where GDB will run; targ is the machine
6014 where the program that you are debugging will run.