1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.9
6 * The "info source" command now displays the producer string if it was
7 present in the debug info. This typically includes the compiler version
8 and may include things like its command line arguments.
12 ** gdb.Objfile objects have a new attribute "username",
13 which is the name of the objfile as specified by the user,
14 without, for example, resolving symlinks.
18 maint print symbol-cache
19 Print the contents of the symbol cache.
21 maint print symbol-cache-statistics
22 Print statistics of symbol cache usage.
24 maint flush-symbol-cache
25 Flush the contents of the symbol cache.
29 Start branch trace recording using Branch Trace Store (BTS) format.
35 Set the maximum number of candidates to be considered during
36 completion. The default value is 200. This limit allows GDB
37 to avoid generating large completion lists, the computation of
38 which can cause the debugger to become temporarily unresponsive.
40 maint set symbol-cache-size
41 maint show symbol-cache-size
42 Control the size of the symbol cache.
44 set|show record btrace bts buffer-size
45 Set and show the size of the ring buffer used for branch tracing in
47 The obtained size may differ from the requested size. Use "info
48 record" to see the obtained buffer size.
50 * The command 'thread apply all' can now support new option '-ascending'
51 to call its specified command for all threads in ascending order.
53 * Python/Guile scripting
55 ** GDB now supports auto-loading of Python/Guile scripts contained in the
56 special section named `.debug_gdb_scripts'.
60 qXfer:btrace-conf:read
61 Return the branch trace configuration for the current thread.
64 Set the requested ring buffer size for branch tracing in BTS format.
67 Indicates a memory breakpoint instruction was executed, irrespective
68 of whether it was GDB that planted the breakpoint or the breakpoint
69 is hardcoded in the program. This is required for correct non-stop
73 Indicates the target stopped for a hardware breakpoint. This is
74 required for correct non-stop mode operation.
76 * The info record command now shows the recording format and the
77 branch tracing configuration for the current thread when using
78 the btrace record target.
79 For the BTS format, it shows the ring buffer size.
81 * GDB now has support for DTrace USDT (Userland Static Defined
82 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
84 * GDB now supports access to vector registers on S/390 GNU/Linux
87 *** Changes in GDB 7.9
89 * GDB now supports hardware watchpoints on x86 GNU Hurd.
93 ** You can now access frame registers from Python scripts.
94 ** New attribute 'producer' for gdb.Symtab objects.
95 ** gdb.Objfile objects have a new attribute "progspace",
96 which is the gdb.Progspace object of the containing program space.
97 ** gdb.Objfile objects have a new attribute "owner".
98 ** gdb.Objfile objects have a new attribute "build_id",
99 which is the build ID generated when the file was built.
100 ** gdb.Objfile objects have a new method "add_separate_debug_file".
101 ** A new event "gdb.clear_objfiles" has been added, triggered when
102 selecting a new file to debug.
103 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
104 ** New function gdb.lookup_objfile.
106 New events which are triggered when GDB modifies the state of the
109 ** gdb.events.inferior_call_pre: Function call is about to be made.
110 ** gdb.events.inferior_call_post: Function call has just been made.
111 ** gdb.events.memory_changed: A memory location has been altered.
112 ** gdb.events.register_changed: A register has been altered.
114 * New Python-based convenience functions:
116 ** $_caller_is(name [, number_of_frames])
117 ** $_caller_matches(regexp [, number_of_frames])
118 ** $_any_caller_is(name [, number_of_frames])
119 ** $_any_caller_matches(regexp [, number_of_frames])
121 * GDB now supports the compilation and injection of source code into
122 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
123 to compile the source code to object code, and if successful, inject
124 and execute that code within the current context of the inferior.
125 Currently the C language is supported. The commands used to
126 interface with this new feature are:
128 compile code [-raw|-r] [--] [source code]
129 compile file [-raw|-r] filename
133 demangle [-l language] [--] name
134 Demangle "name" in the specified language, or the current language
135 if elided. This command is renamed from the "maint demangle" command.
136 The latter is kept as a no-op to avoid "maint demangle" being interpreted
137 as "maint demangler-warning".
139 queue-signal signal-name-or-number
140 Queue a signal to be delivered to the thread when it is resumed.
142 add-auto-load-scripts-directory directory
143 Add entries to the list of directories from which to load auto-loaded
146 maint print user-registers
147 List all currently available "user" registers.
149 compile code [-r|-raw] [--] [source code]
150 Compile, inject, and execute in the inferior the executable object
151 code produced by compiling the provided source code.
153 compile file [-r|-raw] filename
154 Compile and inject into the inferior the executable object code
155 produced by compiling the source code stored in the filename
158 * On resume, GDB now always passes the signal the program had stopped
159 for to the thread the signal was sent to, even if the user changed
160 threads before resuming. Previously GDB would often (but not
161 always) deliver the signal to the thread that happens to be current
164 * Conversely, the "signal" command now consistently delivers the
165 requested signal to the current thread. GDB now asks for
166 confirmation if the program had stopped for a signal and the user
167 switched threads meanwhile.
169 * "breakpoint always-inserted" modes "off" and "auto" merged.
171 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
172 won't remove breakpoints from the target until all threads stop,
173 even in non-stop mode. The "auto" mode has been removed, and "off"
174 is now the default mode.
178 set debug symbol-lookup
179 show debug symbol-lookup
180 Control display of debugging info regarding symbol lookup.
184 ** The -list-thread-groups command outputs an exit-code field for
185 inferiors that have exited.
189 MIPS SDE mips*-sde*-elf*
193 Support for these obsolete configurations has been removed.
195 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
196 SGI Irix-5.x mips-*-irix5*
197 SGI Irix-6.x mips-*-irix6*
198 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
199 VAX running Ultrix vax-*-ultrix*
201 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
202 and "assf"), have been removed. Use the "sharedlibrary" command, or
203 its alias "share", instead.
205 *** Changes in GDB 7.8
207 * New command line options
210 This is an alias for the --data-directory option.
212 * GDB supports printing and modifying of variable length automatic arrays
213 as specified in ISO C99.
215 * The ARM simulator now supports instruction level tracing
216 with or without disassembly.
220 GDB now has support for scripting using Guile. Whether this is
221 available is determined at configure time.
222 Guile version 2.0 or greater is required.
223 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
225 * New commands (for set/show, see "New options" below)
229 Invoke CODE by passing it to the Guile interpreter.
233 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
235 info auto-load guile-scripts [regexp]
236 Print the list of automatically loaded Guile scripts.
238 * The source command is now capable of sourcing Guile scripts.
239 This feature is dependent on the debugger being built with Guile support.
243 set print symbol-loading (off|brief|full)
244 show print symbol-loading
245 Control whether to print informational messages when loading symbol
246 information for a file. The default is "full", but when debugging
247 programs with large numbers of shared libraries the amount of output
250 set guile print-stack (none|message|full)
251 show guile print-stack
252 Show a stack trace when an error is encountered in a Guile script.
254 set auto-load guile-scripts (on|off)
255 show auto-load guile-scripts
256 Control auto-loading of Guile script files.
258 maint ada set ignore-descriptive-types (on|off)
259 maint ada show ignore-descriptive-types
260 Control whether the debugger should ignore descriptive types in Ada
261 programs. The default is not to ignore the descriptive types. See
262 the user manual for more details on descriptive types and the intended
263 usage of this option.
265 set auto-connect-native-target
267 Control whether GDB is allowed to automatically connect to the
268 native target for the run, attach, etc. commands when not connected
269 to any target yet. See also "target native" below.
271 set record btrace replay-memory-access (read-only|read-write)
272 show record btrace replay-memory-access
273 Control what memory accesses are allowed during replay.
275 maint set target-async (on|off)
276 maint show target-async
277 This controls whether GDB targets operate in synchronous or
278 asynchronous mode. Normally the default is asynchronous, if it is
279 available; but this can be changed to more easily debug problems
280 occurring only in synchronous mode.
282 set mi-async (on|off)
284 Control whether MI asynchronous mode is preferred. This supersedes
285 "set target-async" of previous GDB versions.
287 * "set target-async" is deprecated as a CLI option and is now an alias
288 for "set mi-async" (only puts MI into async mode).
290 * Background execution commands (e.g., "c&", "s&", etc.) are now
291 possible ``out of the box'' if the target supports them. Previously
292 the user would need to explicitly enable the possibility with the
293 "set target-async on" command.
295 * New features in the GDB remote stub, GDBserver
297 ** New option --debug-format=option1[,option2,...] allows one to add
298 additional text to each output. At present only timestamps
299 are supported: --debug-format=timestamps.
300 Timestamps can also be turned on with the
301 "monitor set debug-format timestamps" command from GDB.
303 * The 'record instruction-history' command now starts counting instructions
304 at one. This also affects the instruction ranges reported by the
305 'record function-call-history' command when given the /i modifier.
307 * The command 'record function-call-history' supports a new modifier '/c' to
308 indent the function names based on their call stack depth.
309 The fields for the '/i' and '/l' modifier have been reordered.
310 The source line range is now prefixed with 'at'.
311 The instruction range is now prefixed with 'inst'.
312 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
313 "record instruction-history" and "list" commands.
315 * The ranges given as arguments to the 'record function-call-history' and
316 'record instruction-history' commands are now inclusive.
318 * The btrace record target now supports the 'record goto' command.
319 For locations inside the execution trace, the back trace is computed
320 based on the information stored in the execution trace.
322 * The btrace record target supports limited reverse execution and replay.
323 The target does not record data and therefore does not allow reading
326 * The "catch syscall" command now works on s390*-linux* targets.
328 * The "compare-sections" command is no longer specific to target
329 remote. It now works with all targets.
331 * All native targets are now consistently called "native".
332 Consequently, the "target child", "target GNU", "target djgpp",
333 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
334 commands have been replaced with "target native". The QNX/NTO port
335 leaves the "procfs" target in place and adds a "native" target for
336 consistency with other ports. The impact on users should be minimal
337 as these commands previously either throwed an error, or were
338 no-ops. The target's name is visible in the output of the following
339 commands: "help target", "info target", "info files", "maint print
342 * The "target native" command now connects to the native target. This
343 can be used to launch native programs even when "set
344 auto-connect-native-target" is set to off.
346 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.
348 * Support for Intel(R) AVX-512 registers on GNU/Linux.
349 Support displaying and modifying Intel(R) AVX-512 registers
350 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
354 qXfer:btrace:read's annex
355 The qXfer:btrace:read packet supports a new annex 'delta' to read
356 branch trace incrementally.
360 ** Valid Python operations on gdb.Value objects representing
361 structs/classes invoke the corresponding overloaded operators if
363 ** New `Xmethods' feature in the Python API. Xmethods are
364 additional methods or replacements for existing methods of a C++
365 class. This feature is useful for those cases where a method
366 defined in C++ source code could be inlined or optimized out by
367 the compiler, making it unavailable to GDB.
370 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
372 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
373 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
374 its alias "share", instead.
376 * The commands "set remotebaud" and "show remotebaud" are no longer
377 supported. Use "set serial baud" and "show serial baud" (respectively)
382 ** A new option "-gdb-set mi-async" replaces "-gdb-set
383 target-async". The latter is left as a deprecated alias of the
384 former for backward compatibility. If the target supports it,
385 CLI background execution commands are now always possible by
386 default, independently of whether the frontend stated a
387 preference for asynchronous execution with "-gdb-set mi-async".
388 Previously "-gdb-set target-async off" affected both MI execution
389 commands and CLI execution commands.
391 *** Changes in GDB 7.7
393 * Improved support for process record-replay and reverse debugging on
394 arm*-linux* targets. Support for thumb32 and syscall instruction
395 recording has been added.
397 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
399 * GDB now supports Fission DWP file format version 2.
400 http://gcc.gnu.org/wiki/DebugFission
402 * New convenience function "$_isvoid", to check whether an expression
403 is void. A void expression is an expression where the type of the
404 result is "void". For example, some convenience variables may be
405 "void" when evaluated (e.g., "$_exitcode" before the execution of
406 the program being debugged; or an undefined convenience variable).
407 Another example, when calling a function whose return type is
410 * The "maintenance print objfiles" command now takes an optional regexp.
412 * The "catch syscall" command now works on arm*-linux* targets.
414 * GDB now consistently shows "<not saved>" when printing values of
415 registers the debug info indicates have not been saved in the frame
416 and there's nowhere to retrieve them from
417 (callee-saved/call-clobbered registers):
422 (gdb) info registers rax
425 Before, the former would print "<optimized out>", and the latter
426 "*value not available*".
428 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
433 ** Frame filters and frame decorators have been added.
434 ** Temporary breakpoints are now supported.
435 ** Line tables representation has been added.
436 ** New attribute 'parent_type' for gdb.Field objects.
437 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
438 ** New attribute 'name' for gdb.Type objects.
442 Nios II ELF nios2*-*-elf
443 Nios II GNU/Linux nios2*-*-linux
444 Texas Instruments MSP430 msp430*-*-elf
446 * Removed native configurations
448 Support for these a.out NetBSD and OpenBSD obsolete configurations has
449 been removed. ELF variants of these configurations are kept supported.
451 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
452 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
453 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
454 i[34567]86-*-openbsd3.[0-3]
455 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
456 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
457 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
461 Like "catch throw", but catches a re-thrown exception.
463 Renamed from old "maint check-symtabs".
465 Perform consistency checks on symtabs.
467 Expand symtabs matching an optional regexp.
470 Display the details of GDB configure-time options.
472 maint set|show per-command
473 maint set|show per-command space
474 maint set|show per-command time
475 maint set|show per-command symtab
476 Enable display of per-command gdb resource usage.
478 remove-symbol-file FILENAME
479 remove-symbol-file -a ADDRESS
480 Remove a symbol file added via add-symbol-file. The file to remove
481 can be identified by its filename or by an address that lies within
482 the boundaries of this symbol file in memory.
485 info exceptions REGEXP
486 Display the list of Ada exceptions defined in the program being
487 debugged. If provided, only the exceptions whose names match REGEXP
492 set debug symfile off|on
494 Control display of debugging info regarding reading symbol files and
495 symbol tables within those files
497 set print raw frame-arguments
498 show print raw frame-arguments
499 Set/show whether to print frame arguments in raw mode,
500 disregarding any defined pretty-printers.
502 set remote trace-status-packet
503 show remote trace-status-packet
504 Set/show the use of remote protocol qTStatus packet.
508 Control display of debugging messages related to Nios II targets.
512 Control whether target-assisted range stepping is enabled.
514 set startup-with-shell
515 show startup-with-shell
516 Specifies whether Unix child processes are started via a shell or
521 Use the target memory cache for accesses to the code segment. This
522 improves performance of remote debugging (particularly disassembly).
524 * You can now use a literal value 'unlimited' for options that
525 interpret 0 or -1 as meaning "unlimited". E.g., "set
526 trace-buffer-size unlimited" is now an alias for "set
527 trace-buffer-size -1" and "set height unlimited" is now an alias for
530 * The "set debug symtab-create" debugging option of GDB has been changed to
531 accept a verbosity level. 0 means "off", 1 provides basic debugging
532 output, and values of 2 or greater provides more verbose output.
534 * New command-line options
536 Display the details of GDB configure-time options.
538 * The command 'tsave' can now support new option '-ctf' to save trace
539 buffer in Common Trace Format.
541 * Newly installed $prefix/bin/gcore acts as a shell interface for the
544 * GDB now implements the the C++ 'typeid' operator.
546 * The new convenience variable $_exception holds the exception being
547 thrown or caught at an exception-related catchpoint.
549 * The exception-related catchpoints, like "catch throw", now accept a
550 regular expression which can be used to filter exceptions by type.
552 * The new convenience variable $_exitsignal is automatically set to
553 the terminating signal number when the program being debugged dies
554 due to an uncaught signal.
558 ** All MI commands now accept an optional "--language" option.
559 Support for this feature can be verified by using the "-list-features"
560 command, which should contain "language-option".
562 ** The new command -info-gdb-mi-command allows the user to determine
563 whether a GDB/MI command is supported or not.
565 ** The "^error" result record returned when trying to execute an undefined
566 GDB/MI command now provides a variable named "code" whose content is the
567 "undefined-command" error code. Support for this feature can be verified
568 by using the "-list-features" command, which should contain
569 "undefined-command-error-code".
571 ** The -trace-save MI command can optionally save trace buffer in Common
574 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
576 ** The command -data-list-register-values now accepts an optional
577 "--skip-unavailable" option. When used, only the available registers
580 ** The new command -trace-frame-collected dumps collected variables,
581 computed expressions, tvars, memory and registers in a traceframe.
583 ** The commands -stack-list-locals, -stack-list-arguments and
584 -stack-list-variables now accept an option "--skip-unavailable".
585 When used, only the available locals or arguments are displayed.
587 ** The -exec-run command now accepts an optional "--start" option.
588 When used, the command follows the same semantics as the "start"
589 command, stopping the program's execution at the start of its
590 main subprogram. Support for this feature can be verified using
591 the "-list-features" command, which should contain
592 "exec-run-start-option".
594 ** The new commands -catch-assert and -catch-exceptions insert
595 catchpoints stopping the program when Ada exceptions are raised.
597 ** The new command -info-ada-exceptions provides the equivalent of
598 the new "info exceptions" command.
600 * New system-wide configuration scripts
601 A GDB installation now provides scripts suitable for use as system-wide
602 configuration scripts for the following systems:
606 * GDB now supports target-assigned range stepping with remote targets.
607 This improves the performance of stepping source lines by reducing
608 the number of control packets from/to GDB. See "New remote packets"
611 * GDB now understands the element 'tvar' in the XML traceframe info.
612 It has the id of the collected trace state variables.
614 * On S/390 targets that provide the transactional-execution feature,
615 the program interruption transaction diagnostic block (TDB) is now
616 represented as a number of additional "registers" in GDB.
622 The vCont packet supports a new 'r' action, that tells the remote
623 stub to step through an address range itself, without GDB
624 involvemement at each single-step.
626 qXfer:libraries-svr4:read's annex
627 The previously unused annex of the qXfer:libraries-svr4:read packet
628 is now used to support passing an argument list. The remote stub
629 reports support for this argument list to GDB's qSupported query.
630 The defined arguments are "start" and "prev", used to reduce work
631 necessary for library list updating, resulting in significant
634 * New features in the GDB remote stub, GDBserver
636 ** GDBserver now supports target-assisted range stepping. Currently
637 enabled on x86/x86_64 GNU/Linux targets.
639 ** GDBserver now adds element 'tvar' in the XML in the reply to
640 'qXfer:traceframe-info:read'. It has the id of the collected
641 trace state variables.
643 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
646 * New 'z' formatter for printing and examining memory, this displays the
647 value as hexadecimal zero padded on the left to the size of the type.
649 * GDB can now use Windows x64 unwinding data.
651 * The "set remotebaud" command has been replaced by "set serial baud".
652 Similarly, "show remotebaud" has been replaced by "show serial baud".
653 The "set remotebaud" and "show remotebaud" commands are still available
654 to provide backward compatibility with older versions of GDB.
656 *** Changes in GDB 7.6
658 * Target record has been renamed to record-full.
659 Record/replay is now enabled with the "record full" command.
660 This also affects settings that are associated with full record/replay
661 that have been moved from "set/show record" to "set/show record full":
663 set|show record full insn-number-max
664 set|show record full stop-at-limit
665 set|show record full memory-query
667 * A new record target "record-btrace" has been added. The new target
668 uses hardware support to record the control-flow of a process. It
669 does not support replaying the execution, but it implements the
670 below new commands for investigating the recorded execution log.
671 This new recording method can be enabled using:
675 The "record-btrace" target is only available on Intel Atom processors
676 and requires a Linux kernel 2.6.32 or later.
678 * Two new commands have been added for record/replay to give information
679 about the recorded execution without having to replay the execution.
680 The commands are only supported by "record btrace".
682 record instruction-history prints the execution history at
683 instruction granularity
685 record function-call-history prints the execution history at
688 * New native configurations
690 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
691 FreeBSD/powerpc powerpc*-*-freebsd
692 x86_64/Cygwin x86_64-*-cygwin*
693 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
697 ARM AArch64 aarch64*-*-elf
698 ARM AArch64 GNU/Linux aarch64*-*-linux
699 Lynx 178 PowerPC powerpc-*-lynx*178
700 x86_64/Cygwin x86_64-*-cygwin*
701 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
703 * If the configured location of system.gdbinit file (as given by the
704 --with-system-gdbinit option at configure time) is in the
705 data-directory (as specified by --with-gdb-datadir at configure
706 time) or in one of its subdirectories, then GDB will look for the
707 system-wide init file in the directory specified by the
708 --data-directory command-line option.
710 * New command line options:
712 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
713 other initialization files, unlike -nx which disables all of them.
715 * Removed command line options
717 -epoch This was used by the gdb mode in Epoch, an ancient fork of
720 * The 'ptype' and 'whatis' commands now accept an argument to control
723 * 'info proc' now works on some core files.
727 ** Vectors can be created with gdb.Type.vector.
729 ** Python's atexit.register now works in GDB.
731 ** Types can be pretty-printed via a Python API.
733 ** Python 3 is now supported (in addition to Python 2.4 or later)
735 ** New class gdb.Architecture exposes GDB's internal representation
736 of architecture in the Python API.
738 ** New method Frame.architecture returns the gdb.Architecture object
739 corresponding to the frame's architecture.
741 * New Python-based convenience functions:
743 ** $_memeq(buf1, buf2, length)
744 ** $_streq(str1, str2)
746 ** $_regex(str, regex)
748 * The 'cd' command now defaults to using '~' (the home directory) if not
751 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
752 default for GCC since November 2000.
754 * The command 'forward-search' can now be abbreviated as 'fo'.
756 * The command 'info tracepoints' can now display 'installed on target'
757 or 'not installed on target' for each non-pending location of tracepoint.
759 * New configure options
761 --enable-libmcheck/--disable-libmcheck
762 By default, development versions are built with -lmcheck on hosts
763 that support it, in order to help track memory corruption issues.
764 Release versions, on the other hand, are built without -lmcheck
765 by default. The --enable-libmcheck/--disable-libmcheck configure
766 options allow the user to override that default.
767 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
768 This configure option allows the user to build GDB with
769 libbabeltrace using which GDB can read Common Trace Format data.
771 * New commands (for set/show, see "New options" below)
774 Catch signals. This is similar to "handle", but allows commands and
775 conditions to be attached.
778 List the BFDs known to GDB.
780 python-interactive [command]
782 Start a Python interactive prompt, or evaluate the optional command
783 and print the result of expressions.
786 "py" is a new alias for "python".
788 enable type-printer [name]...
789 disable type-printer [name]...
790 Enable or disable type printers.
794 ** For the Renesas Super-H architecture, the "regs" command has been removed
795 (has been deprecated in GDB 7.5), and "info all-registers" should be used
800 set print type methods (on|off)
801 show print type methods
802 Control whether method declarations are displayed by "ptype".
803 The default is to show them.
805 set print type typedefs (on|off)
806 show print type typedefs
807 Control whether typedef definitions are displayed by "ptype".
808 The default is to show them.
810 set filename-display basename|relative|absolute
811 show filename-display
812 Control the way in which filenames is displayed.
813 The default is "relative", which preserves previous behavior.
815 set trace-buffer-size
816 show trace-buffer-size
817 Request target to change the size of trace buffer.
819 set remote trace-buffer-size-packet auto|on|off
820 show remote trace-buffer-size-packet
821 Control the use of the remote protocol `QTBuffer:size' packet.
825 Control display of debugging messages related to ARM AArch64.
828 set debug coff-pe-read
829 show debug coff-pe-read
830 Control display of debugging messages related to reading of COFF/PE
835 Control display of debugging messages related to Mach-O symbols
838 set debug notification
839 show debug notification
840 Control display of debugging info for async remote notification.
844 ** Command parameter changes are now notified using new async record
845 "=cmd-param-changed".
846 ** Trace frame changes caused by command "tfind" are now notified using
847 new async record "=traceframe-changed".
848 ** The creation, deletion and modification of trace state variables
849 are now notified using new async records "=tsv-created",
850 "=tsv-deleted" and "=tsv-modified".
851 ** The start and stop of process record are now notified using new
852 async record "=record-started" and "=record-stopped".
853 ** Memory changes are now notified using new async record
855 ** The data-disassemble command response will include a "fullname" field
856 containing the absolute file name when source has been requested.
857 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
858 command, to allow pattern filling of memory areas.
859 ** New commands "-catch-load"/"-catch-unload" added for intercepting
860 library load/unload events.
861 ** The response to breakpoint commands and breakpoint async records
862 includes an "installed" field containing a boolean state about each
863 non-pending tracepoint location is whether installed on target or not.
864 ** Output of the "-trace-status" command includes a "trace-file" field
865 containing the name of the trace file being examined. This field is
866 optional, and only present when examining a trace file.
867 ** The "fullname" field is now always present along with the "file" field,
868 even if the file cannot be found by GDB.
870 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
871 You must have the LZMA library available when configuring GDB for this
872 feature to be enabled. For more information, see:
873 http://fedoraproject.org/wiki/Features/MiniDebugInfo
878 Set the size of trace buffer. The remote stub reports support for this
879 packet to gdb's qSupported query.
882 Enable Branch Trace Store (BTS)-based branch tracing for the current
883 thread. The remote stub reports support for this packet to gdb's
887 Disable branch tracing for the current thread. The remote stub reports
888 support for this packet to gdb's qSupported query.
891 Read the traced branches for the current thread. The remote stub
892 reports support for this packet to gdb's qSupported query.
894 *** Changes in GDB 7.5
896 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
897 for more x32 ABI info.
899 * GDB now supports access to MIPS DSP registers on Linux targets.
901 * GDB now supports debugging microMIPS binaries.
903 * The "info os" command on GNU/Linux can now display information on
904 several new classes of objects managed by the operating system:
905 "info os procgroups" lists process groups
906 "info os files" lists file descriptors
907 "info os sockets" lists internet-domain sockets
908 "info os shm" lists shared-memory regions
909 "info os semaphores" lists semaphores
910 "info os msg" lists message queues
911 "info os modules" lists loaded kernel modules
913 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
914 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
915 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
916 options and inspect the probe arguments using the new $_probe_arg family
917 of convenience variables. You can obtain more information about SystemTap
918 in <http://sourceware.org/systemtap/>.
920 * GDB now supports reversible debugging on ARM, it allows you to
921 debug basic ARM and THUMB instructions, and provides
922 record/replay support.
924 * The option "symbol-reloading" has been deleted as it is no longer used.
928 ** GDB commands implemented in Python can now be put in command class
931 ** The "maint set python print-stack on|off" is now deleted.
933 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
934 apply "flag enum"-style pretty-printing to any enum.
936 ** gdb.lookup_symbol can now work when there is no current frame.
938 ** gdb.Symbol now has a 'line' attribute, holding the line number in
939 the source at which the symbol was defined.
941 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
942 method 'value'. The former indicates whether the symbol needs a
943 frame in order to compute its value, and the latter computes the
946 ** A new method 'referenced_value' on gdb.Value objects which can
947 dereference pointer as well as C++ reference values.
949 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
950 which return the global and static blocks (as gdb.Block objects),
951 of the underlying symbol table, respectively.
953 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
954 object associated with a PC value.
956 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
957 of the address range occupied by code for the current source line.
959 * Go language support.
960 GDB now supports debugging programs written in the Go programming
963 * GDBserver now supports stdio connections.
964 E.g. (gdb) target remote | ssh myhost gdbserver - hello
966 * The binary "gdbtui" can no longer be built or installed.
967 Use "gdb -tui" instead.
969 * GDB will now print "flag" enums specially. A flag enum is one where
970 all the enumerator values have no bits in common when pairwise
971 "and"ed. When printing a value whose type is a flag enum, GDB will
972 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
973 (gdb) print (enum E) 3
976 * The filename part of a linespec will now match trailing components
977 of a source file name. For example, "break gcc/expr.c:1000" will
978 now set a breakpoint in build/gcc/expr.c, but not
981 * The "info proc" and "generate-core-file" commands will now also
982 work on remote targets connected to GDBserver on Linux.
984 * The command "info catch" has been removed. It has been disabled
987 * The "catch exception" and "catch assert" commands now accept
988 a condition at the end of the command, much like the "break"
989 command does. For instance:
991 (gdb) catch exception Constraint_Error if Barrier = True
993 Previously, it was possible to add a condition to such catchpoints,
994 but it had to be done as a second step, after the catchpoint had been
995 created, using the "condition" command.
997 * The "info static-tracepoint-marker" command will now also work on
998 native Linux targets with in-process agent.
1000 * GDB can now set breakpoints on inlined functions.
1002 * The .gdb_index section has been updated to include symbols for
1003 inlined functions. GDB will ignore older .gdb_index sections by
1004 default, which could cause symbol files to be loaded more slowly
1005 until their .gdb_index sections can be recreated. The new command
1006 "set use-deprecated-index-sections on" will cause GDB to use any older
1007 .gdb_index sections it finds. This will restore performance, but the
1008 ability to set breakpoints on inlined functions will be lost in symbol
1009 files with older .gdb_index sections.
1011 The .gdb_index section has also been updated to record more information
1012 about each symbol. This speeds up the "info variables", "info functions"
1013 and "info types" commands when used with programs having the .gdb_index
1014 section, as well as speeding up debugging with shared libraries using
1015 the .gdb_index section.
1017 * Ada support for GDB/MI Variable Objects has been added.
1019 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1024 ** New command -info-os is the MI equivalent of "info os".
1026 ** Output logs ("set logging" and related) now include MI output.
1030 ** "set use-deprecated-index-sections on|off"
1031 "show use-deprecated-index-sections on|off"
1032 Controls the use of deprecated .gdb_index sections.
1034 ** "catch load" and "catch unload" can be used to stop when a shared
1035 library is loaded or unloaded, respectively.
1037 ** "enable count" can be used to auto-disable a breakpoint after
1040 ** "info vtbl" can be used to show the virtual method tables for
1041 C++ and Java objects.
1043 ** "explore" and its sub commands "explore value" and "explore type"
1044 can be used to recursively explore values and types of
1045 expressions. These commands are available only if GDB is
1046 configured with '--with-python'.
1048 ** "info auto-load" shows status of all kinds of auto-loaded files,
1049 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1050 sequences of commands files, "info auto-load python-scripts"
1051 shows status of auto-loading Python script files,
1052 "info auto-load local-gdbinit" shows status of loading init file
1053 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1054 status of inferior specific thread debugging shared library loading.
1056 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1057 and "show auto-load-scripts" commands have been deprecated, use their
1058 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1059 and "show auto-load python-scripts" counterparts instead.
1061 ** "dprintf location,format,args..." creates a dynamic printf, which
1062 is basically a breakpoint that does a printf and immediately
1063 resumes your program's execution, so it is like a printf that you
1064 can insert dynamically at runtime instead of at compiletime.
1066 ** "set print symbol"
1068 Controls whether GDB attempts to display the symbol, if any,
1069 corresponding to addresses it prints. This defaults to "on", but
1070 you can set it to "off" to restore GDB's previous behavior.
1072 * Deprecated commands
1074 ** For the Renesas Super-H architecture, the "regs" command has been
1075 deprecated, and "info all-registers" should be used instead.
1079 Renesas RL78 rl78-*-elf
1080 HP OpenVMS ia64 ia64-hp-openvms*
1082 * GDBserver supports evaluation of breakpoint conditions. When
1083 support is advertised by GDBserver, GDB may be told to send the
1084 breakpoint conditions in bytecode form to GDBserver. GDBserver
1085 will only report the breakpoint trigger to GDB when its condition
1090 set mips compression
1091 show mips compression
1092 Select the compressed ISA encoding used in functions that have no symbol
1093 information available. The encoding can be set to either of:
1096 and is updated automatically from ELF file flags if available.
1098 set breakpoint condition-evaluation
1099 show breakpoint condition-evaluation
1100 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1101 GDBserver ("target"). Default option "auto" chooses the most efficient
1103 This option can improve debugger efficiency depending on the speed of the
1107 Disable auto-loading globally.
1110 Show auto-loading setting of all kinds of auto-loaded files.
1112 set auto-load gdb-scripts on|off
1113 show auto-load gdb-scripts
1114 Control auto-loading of GDB canned sequences of commands files.
1116 set auto-load python-scripts on|off
1117 show auto-load python-scripts
1118 Control auto-loading of Python script files.
1120 set auto-load local-gdbinit on|off
1121 show auto-load local-gdbinit
1122 Control loading of init file (.gdbinit) from current directory.
1124 set auto-load libthread-db on|off
1125 show auto-load libthread-db
1126 Control auto-loading of inferior specific thread debugging shared library.
1128 set auto-load scripts-directory <dir1>[:<dir2>...]
1129 show auto-load scripts-directory
1130 Set a list of directories from which to load auto-loaded scripts.
1131 Automatically loaded Python scripts and GDB scripts are located in one
1132 of the directories listed by this option.
1133 The delimiter (':' above) may differ according to the host platform.
1135 set auto-load safe-path <dir1>[:<dir2>...]
1136 show auto-load safe-path
1137 Set a list of directories from which it is safe to auto-load files.
1138 The delimiter (':' above) may differ according to the host platform.
1140 set debug auto-load on|off
1141 show debug auto-load
1142 Control display of debugging info for auto-loading the files above.
1144 set dprintf-style gdb|call|agent
1146 Control the way in which a dynamic printf is performed; "gdb"
1147 requests a GDB printf command, while "call" causes dprintf to call a
1148 function in the inferior. "agent" requests that the target agent
1149 (such as GDBserver) do the printing.
1151 set dprintf-function <expr>
1152 show dprintf-function
1153 set dprintf-channel <expr>
1154 show dprintf-channel
1155 Set the function and optional first argument to the call when using
1156 the "call" style of dynamic printf.
1158 set disconnected-dprintf on|off
1159 show disconnected-dprintf
1160 Control whether agent-style dynamic printfs continue to be in effect
1161 after GDB disconnects.
1163 * New configure options
1165 --with-auto-load-dir
1166 Configure default value for the 'set auto-load scripts-directory'
1167 setting above. It defaults to '$debugdir:$datadir/auto-load',
1168 $debugdir representing global debugging info directories (available
1169 via 'show debug-file-directory') and $datadir representing GDB's data
1170 directory (available via 'show data-directory').
1172 --with-auto-load-safe-path
1173 Configure default value for the 'set auto-load safe-path' setting
1174 above. It defaults to the --with-auto-load-dir setting.
1176 --without-auto-load-safe-path
1177 Set 'set auto-load safe-path' to '/', effectively disabling this
1180 * New remote packets
1182 z0/z1 conditional breakpoints extension
1184 The z0/z1 breakpoint insertion packets have been extended to carry
1185 a list of conditional expressions over to the remote stub depending on the
1186 condition evaluation mode. The use of this extension can be controlled
1187 via the "set remote conditional-breakpoints-packet" command.
1191 Specify the signals which the remote stub may pass to the debugged
1192 program without GDB involvement.
1194 * New command line options
1196 --init-command=FILE, -ix Like --command, -x but execute it
1197 before loading inferior.
1198 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1199 execute it before loading inferior.
1201 *** Changes in GDB 7.4
1203 * GDB now handles ambiguous linespecs more consistently; the existing
1204 FILE:LINE support has been expanded to other types of linespecs. A
1205 breakpoint will now be set on all matching locations in all
1206 inferiors, and locations will be added or removed according to
1209 * GDB now allows you to skip uninteresting functions and files when
1210 stepping with the "skip function" and "skip file" commands.
1212 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1213 and "show remote hardware-watchpoint-length-limit". These allows to
1214 set or show the maximum length limit (in bytes) of a remote
1215 target hardware watchpoint.
1217 This allows e.g. to use "unlimited" hardware watchpoints with the
1218 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1219 watchpoints are slower than real hardware watchpoints but are
1220 significantly faster than gdb software watchpoints.
1224 ** The register_pretty_printer function in module gdb.printing now takes
1225 an optional `replace' argument. If True, the new printer replaces any
1228 ** The "maint set python print-stack on|off" command has been
1229 deprecated and will be deleted in GDB 7.5.
1230 A new command: "set python print-stack none|full|message" has
1231 replaced it. Additionally, the default for "print-stack" is
1232 now "message", which just prints the error message without
1235 ** A prompt substitution hook (prompt_hook) is now available to the
1238 ** A new Python module, gdb.prompt has been added to the GDB Python
1239 modules library. This module provides functionality for
1240 escape sequences in prompts (used by set/show
1241 extended-prompt). These escape sequences are replaced by their
1242 corresponding value.
1244 ** Python commands and convenience-functions located in
1245 'data-directory'/python/gdb/command and
1246 'data-directory'/python/gdb/function are now automatically loaded
1249 ** Blocks now provide four new attributes. global_block and
1250 static_block will return the global and static blocks
1251 respectively. is_static and is_global are boolean attributes
1252 that indicate if the block is one of those two types.
1254 ** Symbols now provide the "type" attribute, the type of the symbol.
1256 ** The "gdb.breakpoint" function has been deprecated in favor of
1259 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1260 of a function. This class is based on the "finish" command
1261 available in the CLI.
1263 ** Type objects for struct and union types now allow access to
1264 the fields using standard Python dictionary (mapping) methods.
1265 For example, "some_type['myfield']" now works, as does
1266 "some_type.items()".
1268 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1271 ** A new function, "deep_items" has been added to the gdb.types
1272 module in the GDB Python modules library. This function returns
1273 an iterator over the fields of a struct or union type. Unlike
1274 the standard Python "iteritems" method, it will recursively traverse
1275 any anonymous fields.
1279 ** "*stopped" events can report several new "reason"s, such as
1282 ** Breakpoint changes are now notified using new async records, like
1283 "=breakpoint-modified".
1285 ** New command -ada-task-info.
1287 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1288 $sdir specifies the default system locations of shared libraries.
1289 $pdir specifies the directory where the libpthread used by the application
1292 GDB no longer looks in $sdir and $pdir after it has searched the directories
1293 mentioned in libthread-db-search-path. If you want to search those
1294 directories, they must be specified in libthread-db-search-path.
1295 The default value of libthread-db-search-path on GNU/Linux and Solaris
1296 systems is now "$sdir:$pdir".
1298 $pdir is not supported by gdbserver, it is currently ignored.
1299 $sdir is supported by gdbserver.
1301 * New configure option --with-iconv-bin.
1302 When using the internationalization support like the one in the GNU C
1303 library, GDB will invoke the "iconv" program to get a list of supported
1304 character sets. If this program lives in a non-standard location, one can
1305 use this option to specify where to find it.
1307 * When natively debugging programs on PowerPC BookE processors running
1308 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1309 watchpoints, which specify a mask in addition to an address to watch.
1310 The mask specifies that some bits of an address (the bits which are
1311 reset in the mask) should be ignored when matching the address accessed
1312 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1313 section in the user manual for more details.
1315 * The new option --once causes GDBserver to stop listening for connections once
1316 the first connection is made. The listening port used by GDBserver will
1317 become available after that.
1319 * New commands "info macros" and "alias" have been added.
1321 * New function parameters suffix @entry specifies value of function parameter
1322 at the time the function got called. Entry values are available only since
1328 "!" is now an alias of the "shell" command.
1329 Note that no space is needed between "!" and SHELL COMMAND.
1333 watch EXPRESSION mask MASK_VALUE
1334 The watch command now supports the mask argument which allows creation
1335 of masked watchpoints, if the current architecture supports this feature.
1337 info auto-load-scripts [REGEXP]
1338 This command was formerly named "maintenance print section-scripts".
1339 It is now generally useful and is no longer a maintenance-only command.
1341 info macro [-all] [--] MACRO
1342 The info macro command has new options `-all' and `--'. The first for
1343 printing all definitions of a macro. The second for explicitly specifying
1344 the end of arguments and the beginning of the macro name in case the macro
1345 name starts with a hyphen.
1347 collect[/s] EXPRESSIONS
1348 The tracepoint collect command now takes an optional modifier "/s"
1349 that directs it to dereference pointer-to-character types and
1350 collect the bytes of memory up to a zero byte. The behavior is
1351 similar to what you see when you use the regular print command on a
1352 string. An optional integer following the "/s" sets a bound on the
1353 number of bytes that will be collected.
1356 The trace start command now interprets any supplied arguments as a
1357 note to be recorded with the trace run, with an effect similar to
1358 setting the variable trace-notes.
1361 The trace stop command now interprets any arguments as a note to be
1362 mentioned along with the tstatus report that the trace was stopped
1363 with a command. The effect is similar to setting the variable
1366 * Tracepoints can now be enabled and disabled at any time after a trace
1367 experiment has been started using the standard "enable" and "disable"
1368 commands. It is now possible to start a trace experiment with no enabled
1369 tracepoints; GDB will display a warning, but will allow the experiment to
1370 begin, assuming that tracepoints will be enabled as needed while the trace
1373 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1374 locations with 4-byte instructions, when they were previously
1375 limited to locations with instructions of 5 bytes or longer.
1379 set debug dwarf2-read
1380 show debug dwarf2-read
1381 Turns on or off display of debugging messages related to reading
1382 DWARF debug info. The default is off.
1384 set debug symtab-create
1385 show debug symtab-create
1386 Turns on or off display of debugging messages related to symbol table
1387 creation. The default is off.
1390 show extended-prompt
1391 Set the GDB prompt, and allow escape sequences to be inserted to
1392 display miscellaneous information (see 'help set extended-prompt'
1393 for the list of sequences). This prompt (and any information
1394 accessed through the escape sequences) is updated every time the
1395 prompt is displayed.
1397 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1398 show print entry-values
1399 Set printing of frame argument values at function entry. In some cases
1400 GDB can determine the value of function argument which was passed by the
1401 function caller, even if the value was modified inside the called function.
1403 set debug entry-values
1404 show debug entry-values
1405 Control display of debugging info for determining frame argument values at
1406 function entry and virtual tail call frames.
1408 set basenames-may-differ
1409 show basenames-may-differ
1410 Set whether a source file may have multiple base names.
1411 (A "base name" is the name of a file with the directory part removed.
1412 Example: The base name of "/home/user/hello.c" is "hello.c".)
1413 If set, GDB will canonicalize file names (e.g., expand symlinks)
1414 before comparing them. Canonicalization is an expensive operation,
1415 but it allows the same file be known by more than one base name.
1416 If not set (the default), all source files are assumed to have just
1417 one base name, and gdb will do file name comparisons more efficiently.
1423 Set a user name and notes for the current and any future trace runs.
1424 This is useful for long-running and/or disconnected traces, to
1425 inform others (or yourself) as to who is running the trace, supply
1426 contact information, or otherwise explain what is going on.
1428 set trace-stop-notes
1429 show trace-stop-notes
1430 Set a note attached to the trace run, that is displayed when the
1431 trace has been stopped by a tstop command. This is useful for
1432 instance as an explanation, if you are stopping a trace run that was
1433 started by someone else.
1435 * New remote packets
1439 Dynamically enable a tracepoint in a started trace experiment.
1443 Dynamically disable a tracepoint in a started trace experiment.
1447 Set the user and notes of the trace run.
1451 Query the current status of a tracepoint.
1455 Query the minimum length of instruction at which a fast tracepoint may
1458 * Dcache size (number of lines) and line-size are now runtime-configurable
1459 via "set dcache line" and "set dcache line-size" commands.
1463 Texas Instruments TMS320C6x tic6x-*-*
1467 Renesas RL78 rl78-*-elf
1469 *** Changes in GDB 7.3.1
1471 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1473 *** Changes in GDB 7.3
1475 * GDB has a new command: "thread find [REGEXP]".
1476 It finds the thread id whose name, target id, or thread extra info
1477 matches the given regular expression.
1479 * The "catch syscall" command now works on mips*-linux* targets.
1481 * The -data-disassemble MI command now supports modes 2 and 3 for
1482 dumping the instruction opcodes.
1484 * New command line options
1486 -data-directory DIR Specify DIR as the "data-directory".
1487 This is mostly for testing purposes.
1489 * The "maint set python auto-load on|off" command has been renamed to
1490 "set auto-load-scripts on|off".
1492 * GDB has a new command: "set directories".
1493 It is like the "dir" command except that it replaces the
1494 source path list instead of augmenting it.
1496 * GDB now understands thread names.
1498 On GNU/Linux, "info threads" will display the thread name as set by
1499 prctl or pthread_setname_np.
1501 There is also a new command, "thread name", which can be used to
1502 assign a name internally for GDB to display.
1505 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1506 has been integrated into GDB.
1510 ** The function gdb.Write now accepts an optional keyword 'stream'.
1511 This keyword, when provided, will direct the output to either
1512 stdout, stderr, or GDB's logging output.
1514 ** Parameters can now be be sub-classed in Python, and in particular
1515 you may implement the get_set_doc and get_show_doc functions.
1516 This improves how Parameter set/show documentation is processed
1517 and allows for more dynamic content.
1519 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1520 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1521 have an is_valid method.
1523 ** Breakpoints can now be sub-classed in Python, and in particular
1524 you may implement a 'stop' function that is executed each time
1525 the inferior reaches that breakpoint.
1527 ** New function gdb.lookup_global_symbol looks up a global symbol.
1529 ** GDB values in Python are now callable if the value represents a
1530 function. For example, if 'some_value' represents a function that
1531 takes two integer parameters and returns a value, you can call
1532 that function like so:
1534 result = some_value (10,20)
1536 ** Module gdb.types has been added.
1537 It contains a collection of utilities for working with gdb.Types objects:
1538 get_basic_type, has_field, make_enum_dict.
1540 ** Module gdb.printing has been added.
1541 It contains utilities for writing and registering pretty-printers.
1542 New classes: PrettyPrinter, SubPrettyPrinter,
1543 RegexpCollectionPrettyPrinter.
1544 New function: register_pretty_printer.
1546 ** New commands "info pretty-printers", "enable pretty-printer" and
1547 "disable pretty-printer" have been added.
1549 ** gdb.parameter("directories") is now available.
1551 ** New function gdb.newest_frame returns the newest frame in the
1554 ** The gdb.InferiorThread class has a new "name" attribute. This
1555 holds the thread's name.
1557 ** Python Support for Inferior events.
1558 Python scripts can add observers to be notified of events
1559 occurring in the process being debugged.
1560 The following events are currently supported:
1561 - gdb.events.cont Continue event.
1562 - gdb.events.exited Inferior exited event.
1563 - gdb.events.stop Signal received, and Breakpoint hit events.
1567 ** GDB now puts template parameters in scope when debugging in an
1568 instantiation. For example, if you have:
1570 template<int X> int func (void) { return X; }
1572 then if you step into func<5>, "print X" will show "5". This
1573 feature requires proper debuginfo support from the compiler; it
1574 was added to GCC 4.5.
1576 ** The motion commands "next", "finish", "until", and "advance" now
1577 work better when exceptions are thrown. In particular, GDB will
1578 no longer lose control of the inferior; instead, the GDB will
1579 stop the inferior at the point at which the exception is caught.
1580 This functionality requires a change in the exception handling
1581 code that was introduced in GCC 4.5.
1583 * GDB now follows GCC's rules on accessing volatile objects when
1584 reading or writing target state during expression evaluation.
1585 One notable difference to prior behavior is that "print x = 0"
1586 no longer generates a read of x; the value of the assignment is
1587 now always taken directly from the value being assigned.
1589 * GDB now has some support for using labels in the program's source in
1590 linespecs. For instance, you can use "advance label" to continue
1591 execution to a label.
1593 * GDB now has support for reading and writing a new .gdb_index
1594 section. This section holds a fast index of DWARF debugging
1595 information and can be used to greatly speed up GDB startup and
1596 operation. See the documentation for `save gdb-index' for details.
1598 * The "watch" command now accepts an optional "-location" argument.
1599 When used, this causes GDB to watch the memory referred to by the
1600 expression. Such a watchpoint is never deleted due to it going out
1603 * GDB now supports thread debugging of core dumps on GNU/Linux.
1605 GDB now activates thread debugging using the libthread_db library
1606 when debugging GNU/Linux core dumps, similarly to when debugging
1607 live processes. As a result, when debugging a core dump file, GDB
1608 is now able to display pthread_t ids of threads. For example, "info
1609 threads" shows the same output as when debugging the process when it
1610 was live. In earlier releases, you'd see something like this:
1613 * 1 LWP 6780 main () at main.c:10
1615 While now you see this:
1618 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1620 It is also now possible to inspect TLS variables when debugging core
1623 When debugging a core dump generated on a machine other than the one
1624 used to run GDB, you may need to point GDB at the correct
1625 libthread_db library with the "set libthread-db-search-path"
1626 command. See the user manual for more details on this command.
1628 * When natively debugging programs on PowerPC BookE processors running
1629 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1630 which stop execution of the inferior whenever it executes an instruction
1631 at any address within the specified range. See the "PowerPC Embedded"
1632 section in the user manual for more details.
1634 * New features in the GDB remote stub, GDBserver
1636 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1637 and i686 LynxOS (version 5.x).
1639 ** GDBserver is now supported on Blackfin Linux.
1641 * New native configurations
1643 ia64 HP-UX ia64-*-hpux*
1647 Analog Devices, Inc. Blackfin Processor bfin-*
1649 * Ada task switching is now supported on sparc-elf targets when
1650 debugging a program using the Ravenscar Profile. For more information,
1651 see the "Tasking Support when using the Ravenscar Profile" section
1652 in the GDB user manual.
1654 * Guile support was removed.
1656 * New features in the GNU simulator
1658 ** The --map-info flag lists all known core mappings.
1660 ** CFI flashes may be simulated via the "cfi" device.
1662 *** Changes in GDB 7.2
1664 * Shared library support for remote targets by default
1666 When GDB is configured for a generic, non-OS specific target, like
1667 for example, --target=arm-eabi or one of the many *-*-elf targets,
1668 GDB now queries remote stubs for loaded shared libraries using the
1669 `qXfer:libraries:read' packet. Previously, shared library support
1670 was always disabled for such configurations.
1674 ** Argument Dependent Lookup (ADL)
1676 In C++ ADL lookup directs function search to the namespaces of its
1677 arguments even if the namespace has not been imported.
1687 Here the compiler will search for `foo' in the namespace of 'b'
1688 and find A::foo. GDB now supports this. This construct is commonly
1689 used in the Standard Template Library for operators.
1691 ** Improved User Defined Operator Support
1693 In addition to member operators, GDB now supports lookup of operators
1694 defined in a namespace and imported with a `using' directive, operators
1695 defined in the global scope, operators imported implicitly from an
1696 anonymous namespace, and the ADL operators mentioned in the previous
1698 GDB now also supports proper overload resolution for all the previously
1699 mentioned flavors of operators.
1701 ** static const class members
1703 Printing of static const class members that are initialized in the
1704 class definition has been fixed.
1706 * Windows Thread Information Block access.
1708 On Windows targets, GDB now supports displaying the Windows Thread
1709 Information Block (TIB) structure. This structure is visible either
1710 by using the new command `info w32 thread-information-block' or, by
1711 dereferencing the new convenience variable named `$_tlb', a
1712 thread-specific pointer to the TIB. This feature is also supported
1713 when remote debugging using GDBserver.
1715 * Static tracepoints
1717 Static tracepoints are calls in the user program into a tracing
1718 library. One such library is a port of the LTTng kernel tracer to
1719 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1720 When debugging with GDBserver, GDB now supports combining the GDB
1721 tracepoint machinery with such libraries. For example: the user can
1722 use GDB to probe a static tracepoint marker (a call from the user
1723 program into the tracing library) with the new "strace" command (see
1724 "New commands" below). This creates a "static tracepoint" in the
1725 breakpoint list, that can be manipulated with the same feature set
1726 as fast and regular tracepoints. E.g., collect registers, local and
1727 global variables, collect trace state variables, and define
1728 tracepoint conditions. In addition, the user can collect extra
1729 static tracepoint marker specific data, by collecting the new
1730 $_sdata internal variable. When analyzing the trace buffer, you can
1731 inspect $_sdata like any other variable available to GDB. For more
1732 information, see the "Tracepoints" chapter in GDB user manual. New
1733 remote packets have been defined to support static tracepoints, see
1734 the "New remote packets" section below.
1736 * Better reconstruction of tracepoints after disconnected tracing
1738 GDB will attempt to download the original source form of tracepoint
1739 definitions when starting a trace run, and then will upload these
1740 upon reconnection to the target, resulting in a more accurate
1741 reconstruction of the tracepoints that are in use on the target.
1745 You can now exercise direct control over the ways that GDB can
1746 affect your program. For instance, you can disallow the setting of
1747 breakpoints, so that the program can run continuously (assuming
1748 non-stop mode). In addition, the "observer" variable is available
1749 to switch all of the different controls; in observer mode, GDB
1750 cannot affect the target's behavior at all, which is useful for
1751 tasks like diagnosing live systems in the field.
1753 * The new convenience variable $_thread holds the number of the
1756 * New remote packets
1760 Return the address of the Windows Thread Information Block of a given thread.
1764 In response to several of the tracepoint packets, the target may now
1765 also respond with a number of intermediate `qRelocInsn' request
1766 packets before the final result packet, to have GDB handle
1767 relocating an instruction to execute at a different address. This
1768 is particularly useful for stubs that support fast tracepoints. GDB
1769 reports support for this feature in the qSupported packet.
1773 List static tracepoint markers in the target program.
1777 List static tracepoint markers at a given address in the target
1780 qXfer:statictrace:read
1782 Read the static trace data collected (by a `collect $_sdata'
1783 tracepoint action). The remote stub reports support for this packet
1784 to gdb's qSupported query.
1788 Send the current settings of GDB's permission flags.
1792 Send part of the source (textual) form of a tracepoint definition,
1793 which includes location, conditional, and action list.
1795 * The source command now accepts a -s option to force searching for the
1796 script in the source search path even if the script name specifies
1799 * New features in the GDB remote stub, GDBserver
1801 - GDBserver now support tracepoints (including fast tracepoints, and
1802 static tracepoints). The feature is currently supported by the
1803 i386-linux and amd64-linux builds. See the "Tracepoints support
1804 in gdbserver" section in the manual for more information.
1806 GDBserver JIT compiles the tracepoint's conditional agent
1807 expression bytecode into native code whenever possible for low
1808 overhead dynamic tracepoints conditionals. For such tracepoints,
1809 an expression that examines program state is evaluated when the
1810 tracepoint is reached, in order to determine whether to capture
1811 trace data. If the condition is simple and false, processing the
1812 tracepoint finishes very quickly and no data is gathered.
1814 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1815 for static tracepoints support.
1817 - GDBserver now supports x86_64 Windows 64-bit debugging.
1819 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1820 it understands register description.
1822 * The --batch flag now disables pagination and queries.
1824 * X86 general purpose registers
1826 GDB now supports reading/writing byte, word and double-word x86
1827 general purpose registers directly. This means you can use, say,
1828 $ah or $ax to refer, respectively, to the byte register AH and
1829 16-bit word register AX that are actually portions of the 32-bit
1830 register EAX or 64-bit register RAX.
1832 * The `commands' command now accepts a range of breakpoints to modify.
1833 A plain `commands' following a command that creates multiple
1834 breakpoints affects all the breakpoints set by that command. This
1835 applies to breakpoints set by `rbreak', and also applies when a
1836 single `break' command creates multiple breakpoints (e.g.,
1837 breakpoints on overloaded c++ functions).
1839 * The `rbreak' command now accepts a filename specification as part of
1840 its argument, limiting the functions selected by the regex to those
1841 in the specified file.
1843 * Support for remote debugging Windows and SymbianOS shared libraries
1844 from Unix hosts has been improved. Non Windows GDB builds now can
1845 understand target reported file names that follow MS-DOS based file
1846 system semantics, such as file names that include drive letters and
1847 use the backslash character as directory separator. This makes it
1848 possible to transparently use the "set sysroot" and "set
1849 solib-search-path" on Unix hosts to point as host copies of the
1850 target's shared libraries. See the new command "set
1851 target-file-system-kind" described below, and the "Commands to
1852 specify files" section in the user manual for more information.
1856 eval template, expressions...
1857 Convert the values of one or more expressions under the control
1858 of the string template to a command line, and call it.
1860 set target-file-system-kind unix|dos-based|auto
1861 show target-file-system-kind
1862 Set or show the assumed file system kind for target reported file
1865 save breakpoints <filename>
1866 Save all current breakpoint definitions to a file suitable for use
1867 in a later debugging session. To read the saved breakpoint
1868 definitions, use the `source' command.
1870 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1873 info static-tracepoint-markers
1874 Display information about static tracepoint markers in the target.
1876 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1877 Define a static tracepoint by probing a marker at the given
1878 function, line, address, or marker ID.
1882 Enable and disable observer mode.
1884 set may-write-registers on|off
1885 set may-write-memory on|off
1886 set may-insert-breakpoints on|off
1887 set may-insert-tracepoints on|off
1888 set may-insert-fast-tracepoints on|off
1889 set may-interrupt on|off
1890 Set individual permissions for GDB effects on the target. Note that
1891 some of these settings can have undesirable or surprising
1892 consequences, particularly when changed in the middle of a session.
1893 For instance, disabling the writing of memory can prevent
1894 breakpoints from being inserted, cause single-stepping to fail, or
1895 even crash your program, if you disable after breakpoints have been
1896 inserted. However, GDB should not crash.
1898 set record memory-query on|off
1899 show record memory-query
1900 Control whether to stop the inferior if memory changes caused
1901 by an instruction cannot be recorded.
1906 The disassemble command now supports "start,+length" form of two arguments.
1910 ** GDB now provides a new directory location, called the python directory,
1911 where Python scripts written for GDB can be installed. The location
1912 of that directory is <data-directory>/python, where <data-directory>
1913 is the GDB data directory. For more details, see section `Scripting
1914 GDB using Python' in the manual.
1916 ** The GDB Python API now has access to breakpoints, symbols, symbol
1917 tables, program spaces, inferiors, threads and frame's code blocks.
1918 Additionally, GDB Parameters can now be created from the API, and
1919 manipulated via set/show in the CLI.
1921 ** New functions gdb.target_charset, gdb.target_wide_charset,
1922 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1924 ** New exception gdb.GdbError.
1926 ** Pretty-printers are now also looked up in the current program space.
1928 ** Pretty-printers can now be individually enabled and disabled.
1930 ** GDB now looks for names of Python scripts to auto-load in a
1931 special section named `.debug_gdb_scripts', in addition to looking
1932 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1934 * Tracepoint actions were unified with breakpoint commands. In particular,
1935 there are no longer differences in "info break" output for breakpoints and
1936 tracepoints and the "commands" command can be used for both tracepoints and
1937 regular breakpoints.
1941 ARM Symbian arm*-*-symbianelf*
1943 * D language support.
1944 GDB now supports debugging programs written in the D programming
1947 * GDB now supports the extended ptrace interface for PowerPC which is
1948 available since Linux kernel version 2.6.34. This automatically enables
1949 any hardware breakpoints and additional hardware watchpoints available in
1950 the processor. The old ptrace interface exposes just one hardware
1951 watchpoint and no hardware breakpoints.
1953 * GDB is now able to use the Data Value Compare (DVC) register available on
1954 embedded PowerPC processors to implement in hardware simple watchpoint
1955 conditions of the form:
1957 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1959 This works in native GDB running on Linux kernels with the extended ptrace
1960 interface mentioned above.
1962 *** Changes in GDB 7.1
1966 ** Namespace Support
1968 GDB now supports importing of namespaces in C++. This enables the
1969 user to inspect variables from imported namespaces. Support for
1970 namepace aliasing has also been added. So, if a namespace is
1971 aliased in the current scope (e.g. namepace C=A; ) the user can
1972 print variables using the alias (e.g. (gdb) print C::x).
1976 All known bugs relating to the printing of virtual base class were
1977 fixed. It is now possible to call overloaded static methods using a
1982 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1983 and reinterpret_cast<> are now handled by the C++ expression parser.
1987 Xilinx MicroBlaze microblaze-*-*
1992 Xilinx MicroBlaze microblaze
1995 * Multi-program debugging.
1997 GDB now has support for multi-program (a.k.a. multi-executable or
1998 multi-exec) debugging. This allows for debugging multiple inferiors
1999 simultaneously each running a different program under the same GDB
2000 session. See "Debugging Multiple Inferiors and Programs" in the
2001 manual for more information. This implied some user visible changes
2002 in the multi-inferior support. For example, "info inferiors" now
2003 lists inferiors that are not running yet or that have exited
2004 already. See also "New commands" and "New options" below.
2006 * New tracing features
2008 GDB's tracepoint facility now includes several new features:
2010 ** Trace state variables
2012 GDB tracepoints now include support for trace state variables, which
2013 are variables managed by the target agent during a tracing
2014 experiment. They are useful for tracepoints that trigger each
2015 other, so for instance one tracepoint can count hits in a variable,
2016 and then a second tracepoint has a condition that is true when the
2017 count reaches a particular value. Trace state variables share the
2018 $-syntax of GDB convenience variables, and can appear in both
2019 tracepoint actions and condition expressions. Use the "tvariable"
2020 command to create, and "info tvariables" to view; see "Trace State
2021 Variables" in the manual for more detail.
2025 GDB now includes an option for defining fast tracepoints, which
2026 targets may implement more efficiently, such as by installing a jump
2027 into the target agent rather than a trap instruction. The resulting
2028 speedup can be by two orders of magnitude or more, although the
2029 tradeoff is that some program locations on some target architectures
2030 might not allow fast tracepoint installation, for instance if the
2031 instruction to be replaced is shorter than the jump. To request a
2032 fast tracepoint, use the "ftrace" command, with syntax identical to
2033 the regular trace command.
2035 ** Disconnected tracing
2037 It is now possible to detach GDB from the target while it is running
2038 a trace experiment, then reconnect later to see how the experiment
2039 is going. In addition, a new variable disconnected-tracing lets you
2040 tell the target agent whether to continue running a trace if the
2041 connection is lost unexpectedly.
2045 GDB now has the ability to save the trace buffer into a file, and
2046 then use that file as a target, similarly to you can do with
2047 corefiles. You can select trace frames, print data that was
2048 collected in them, and use tstatus to display the state of the
2049 tracing run at the moment that it was saved. To create a trace
2050 file, use "tsave <filename>", and to use it, do "target tfile
2053 ** Circular trace buffer
2055 You can ask the target agent to handle the trace buffer as a
2056 circular buffer, discarding the oldest trace frames to make room for
2057 newer ones, by setting circular-trace-buffer to on. This feature may
2058 not be available for all target agents.
2063 The disassemble command, when invoked with two arguments, now requires
2064 the arguments to be comma-separated.
2067 The info variables command now displays variable definitions. Files
2068 which only declare a variable are not shown.
2071 The source command is now capable of sourcing Python scripts.
2072 This feature is dependent on the debugger being build with Python
2075 Related to this enhancement is also the introduction of a new command
2076 "set script-extension" (see below).
2078 * New commands (for set/show, see "New options" below)
2080 record save [<FILENAME>]
2081 Save a file (in core file format) containing the process record
2082 execution log for replay debugging at a later time.
2084 record restore <FILENAME>
2085 Restore the process record execution log that was saved at an
2086 earlier time, for replay debugging.
2088 add-inferior [-copies <N>] [-exec <FILENAME>]
2091 clone-inferior [-copies <N>] [ID]
2092 Make a new inferior ready to execute the same program another
2093 inferior has loaded.
2098 maint info program-spaces
2099 List the program spaces loaded into GDB.
2101 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2102 show remote interrupt-sequence
2103 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2104 as the sequence to the remote target in order to interrupt the execution.
2105 Ctrl-C is a default. Some system prefers BREAK which is high level of
2106 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2107 Magic SysRq g. It is BREAK signal and character 'g'.
2109 set remote interrupt-on-connect [on | off]
2110 show remote interrupt-on-connect
2111 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2112 remote target when gdb connects to it. This is needed when you debug
2115 set remotebreak [on | off]
2117 Deprecated. Use "set/show remote interrupt-sequence" instead.
2119 tvariable $NAME [ = EXP ]
2120 Create or modify a trace state variable.
2123 List trace state variables and their values.
2125 delete tvariable $NAME ...
2126 Delete one or more trace state variables.
2129 Evaluate the given expressions without collecting anything into the
2130 trace buffer. (Valid in tracepoint actions only.)
2132 ftrace FN / FILE:LINE / *ADDR
2133 Define a fast tracepoint at the given function, line, or address.
2135 * New expression syntax
2137 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2138 GDB now parses 0b101010 identically with 42.
2142 set follow-exec-mode new|same
2143 show follow-exec-mode
2144 Control whether GDB reuses the same inferior across an exec call or
2145 creates a new one. This is useful to be able to restart the old
2146 executable after the inferior having done an exec call.
2148 set default-collect EXPR, ...
2149 show default-collect
2150 Define a list of expressions to be collected at each tracepoint.
2151 This is a useful way to ensure essential items are not overlooked,
2152 such as registers or a critical global variable.
2154 set disconnected-tracing
2155 show disconnected-tracing
2156 If set to 1, the target is instructed to continue tracing if it
2157 loses its connection to GDB. If 0, the target is to stop tracing
2160 set circular-trace-buffer
2161 show circular-trace-buffer
2162 If set to on, the target is instructed to use a circular trace buffer
2163 and discard the oldest trace frames instead of stopping the trace due
2164 to a full trace buffer. If set to off, the trace stops when the buffer
2165 fills up. Some targets may not support this.
2167 set script-extension off|soft|strict
2168 show script-extension
2169 If set to "off", the debugger does not perform any script language
2170 recognition, and all sourced files are assumed to be GDB scripts.
2171 If set to "soft" (the default), files are sourced according to
2172 filename extension, falling back to GDB scripts if the first
2174 If set to "strict", files are sourced according to filename extension.
2176 set ada trust-PAD-over-XVS on|off
2177 show ada trust-PAD-over-XVS
2178 If off, activate a workaround against a bug in the debugging information
2179 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2180 the GCC sources for more information about the GNAT encoding and
2181 PAD types in particular). It is always safe to set this option to
2182 off, but this introduces a slight performance penalty. The default
2185 * Python API Improvements
2187 ** GDB provides the new class gdb.LazyString. This is useful in
2188 some pretty-printing cases. The new method gdb.Value.lazy_string
2189 provides a simple way to create objects of this type.
2191 ** The fields returned by gdb.Type.fields now have an
2192 `is_base_class' attribute.
2194 ** The new method gdb.Type.range returns the range of an array type.
2196 ** The new method gdb.parse_and_eval can be used to parse and
2197 evaluate an expression.
2199 * New remote packets
2202 Define a trace state variable.
2205 Get the current value of a trace state variable.
2208 Set desired tracing behavior upon disconnection.
2211 Set the trace buffer to be linear or circular.
2214 Get data about the tracepoints currently in use.
2218 Process record now works correctly with hardware watchpoints.
2220 Multiple bug fixes have been made to the mips-irix port, making it
2221 much more reliable. In particular:
2222 - Debugging threaded applications is now possible again. Previously,
2223 GDB would hang while starting the program, or while waiting for
2224 the program to stop at a breakpoint.
2225 - Attaching to a running process no longer hangs.
2226 - An error occurring while loading a core file has been fixed.
2227 - Changing the value of the PC register now works again. This fixes
2228 problems observed when using the "jump" command, or when calling
2229 a function from GDB, or even when assigning a new value to $pc.
2230 - With the "finish" and "return" commands, the return value for functions
2231 returning a small array is now correctly printed.
2232 - It is now possible to break on shared library code which gets executed
2233 during a shared library init phase (code executed while executing
2234 their .init section). Previously, the breakpoint would have no effect.
2235 - GDB is now able to backtrace through the signal handler for
2236 non-threaded programs.
2238 PIE (Position Independent Executable) programs debugging is now supported.
2239 This includes debugging execution of PIC (Position Independent Code) shared
2240 libraries although for that, it should be possible to run such libraries as an
2243 *** Changes in GDB 7.0
2245 * GDB now has an interface for JIT compilation. Applications that
2246 dynamically generate code can create symbol files in memory and register
2247 them with GDB. For users, the feature should work transparently, and
2248 for JIT developers, the interface is documented in the GDB manual in the
2249 "JIT Compilation Interface" chapter.
2251 * Tracepoints may now be conditional. The syntax is as for
2252 breakpoints; either an "if" clause appended to the "trace" command,
2253 or the "condition" command is available. GDB sends the condition to
2254 the target for evaluation using the same bytecode format as is used
2255 for tracepoint actions.
2257 * The disassemble command now supports: an optional /r modifier, print the
2258 raw instructions in hex as well as in symbolic form, and an optional /m
2259 modifier to print mixed source+assembly.
2261 * Process record and replay
2263 In a architecture environment that supports ``process record and
2264 replay'', ``process record and replay'' target can record a log of
2265 the process execution, and replay it with both forward and reverse
2268 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2269 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2270 set execution-direction {forward|reverse}, for targets that support
2273 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2274 feature is available with a native GDB running on kernel version
2277 * GDB now has support for multi-byte and wide character sets on the
2278 target. Strings whose character type is wchar_t, char16_t, or
2279 char32_t are now correctly printed. GDB supports wide- and unicode-
2280 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2281 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2282 `printf'. This feature requires iconv to work properly; if your
2283 system does not have a working iconv, GDB can use GNU libiconv. See
2284 the installation instructions for more information.
2286 * GDB now supports automatic retrieval of shared library files from
2287 remote targets. To use this feature, specify a system root that begins
2288 with the `remote:' prefix, either via the `set sysroot' command or via
2289 the `--with-sysroot' configure-time option.
2291 * "info sharedlibrary" now takes an optional regex of libraries to show,
2292 and it now reports if a shared library has no debugging information.
2294 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2295 now complete on file names.
2297 * When completing in expressions, gdb will attempt to limit
2298 completions to allowable structure or union fields, where appropriate.
2299 For instance, consider:
2301 # struct example { int f1; double f2; };
2302 # struct example variable;
2305 If the user types TAB at the end of this command line, the available
2306 completions will be "f1" and "f2".
2308 * Inlined functions are now supported. They show up in backtraces, and
2309 the "step", "next", and "finish" commands handle them automatically.
2311 * GDB now supports the token-splicing (##) and stringification (#)
2312 operators when expanding macros. It also supports variable-arity
2315 * GDB now supports inspecting extra signal information, exported by
2316 the new $_siginfo convenience variable. The feature is currently
2317 implemented on linux ARM, i386 and amd64.
2319 * GDB can now display the VFP floating point registers and NEON vector
2320 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2321 can provide these registers (requires Linux 2.6.30 or later). Remote
2322 and simulator targets may also provide them.
2324 * New remote packets
2327 Search memory for a sequence of bytes.
2330 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2331 operation over reliable transport links. Use of this packet is
2332 controlled by the `set remote noack-packet' command.
2335 Kill the process with the specified process ID. Use this in preference
2336 to `k' when multiprocess protocol extensions are supported.
2339 Obtains additional operating system information
2343 Read or write additional signal information.
2345 * Removed remote protocol undocumented extension
2347 An undocumented extension to the remote protocol's `S' stop reply
2348 packet that permited the stub to pass a process id was removed.
2349 Remote servers should use the `T' stop reply packet instead.
2351 * GDB now supports multiple function calling conventions according to the
2352 DWARF-2 DW_AT_calling_convention function attribute.
2354 * The SH target utilizes the aforementioned change to distinguish between gcc
2355 and Renesas calling convention. It also adds the new CLI commands
2356 `set/show sh calling-convention'.
2358 * GDB can now read compressed debug sections, as produced by GNU gold
2359 with the --compress-debug-sections=zlib flag.
2361 * 64-bit core files are now supported on AIX.
2363 * Thread switching is now supported on Tru64.
2365 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2366 which will be allocated using malloc later in program execution.
2368 * The qXfer:libraries:read remote procotol packet now allows passing a
2369 list of section offsets.
2371 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2372 conditions handling signals delivered during attach or thread creation
2373 have also been fixed.
2375 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2376 From the user's standpoint, all unqualified instances of True and False
2377 are treated as the standard definitions, regardless of context.
2379 * GDB now parses C++ symbol and type names more flexibly. For
2382 template<typename T> class C { };
2385 GDB will now correctly handle all of:
2387 ptype C<char const *>
2388 ptype C<char const*>
2389 ptype C<const char *>
2390 ptype C<const char*>
2392 * New features in the GDB remote stub, gdbserver
2394 - The "--wrapper" command-line argument tells gdbserver to use a
2395 wrapper program to launch programs for debugging.
2397 - On PowerPC and S/390 targets, it is now possible to use a single
2398 gdbserver executable to debug both 32-bit and 64-bit programs.
2399 (This requires gdbserver itself to be built as a 64-bit executable.)
2401 - gdbserver uses the new noack protocol mode for TCP connections to
2402 reduce communications latency, if also supported and enabled in GDB.
2404 - Support for the sparc64-linux-gnu target is now included in
2407 - The amd64-linux build of gdbserver now supports debugging both
2408 32-bit and 64-bit programs.
2410 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2411 now support hardware watchpoints, and will use them automatically
2416 GDB now has support for scripting using Python. Whether this is
2417 available is determined at configure time.
2419 New GDB commands can now be written in Python.
2421 * Ada tasking support
2423 Ada tasks can now be inspected in GDB. The following commands have
2427 Print the list of Ada tasks.
2429 Print detailed information about task number N.
2431 Print the task number of the current task.
2433 Switch the context of debugging to task number N.
2435 * Support for user-defined prefixed commands. The "define" command can
2436 add new commands to existing prefixes, e.g. "target".
2438 * Multi-inferior, multi-process debugging.
2440 GDB now has generalized support for multi-inferior debugging. See
2441 "Debugging Multiple Inferiors" in the manual for more information.
2442 Although availability still depends on target support, the command
2443 set is more uniform now. The GNU/Linux specific multi-forks support
2444 has been migrated to this new framework. This implied some user
2445 visible changes; see "New commands" and also "Removed commands"
2448 * Target descriptions can now describe the target OS ABI. See the
2449 "Target Description Format" section in the user manual for more
2452 * Target descriptions can now describe "compatible" architectures
2453 to indicate that the target can execute applications for a different
2454 architecture in addition to those for the main target architecture.
2455 See the "Target Description Format" section in the user manual for
2458 * Multi-architecture debugging.
2460 GDB now includes general supports for debugging applications on
2461 hybrid systems that use more than one single processor architecture
2462 at the same time. Each such hybrid architecture still requires
2463 specific support to be added. The only hybrid architecture supported
2464 in this version of GDB is the Cell Broadband Engine.
2466 * GDB now supports integrated debugging of Cell/B.E. applications that
2467 use both the PPU and SPU architectures. To enable support for hybrid
2468 Cell/B.E. debugging, you need to configure GDB to support both the
2469 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2470 --enable-targets configure option.
2472 * Non-stop mode debugging.
2474 For some targets, GDB now supports an optional mode of operation in
2475 which you can examine stopped threads while other threads continue
2476 to execute freely. This is referred to as non-stop mode, with the
2477 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2478 section in the user manual for more information.
2480 To be able to support remote non-stop debugging, a remote stub needs
2481 to implement the non-stop mode remote protocol extensions, as
2482 described in the "Remote Non-Stop" section of the user manual. The
2483 GDB remote stub, gdbserver, has been adjusted to support these
2484 extensions on linux targets.
2486 * New commands (for set/show, see "New options" below)
2488 catch syscall [NAME(S) | NUMBER(S)]
2489 Catch system calls. Arguments, which should be names of system
2490 calls or their numbers, mean catch only those syscalls. Without
2491 arguments, every syscall will be caught. When the inferior issues
2492 any of the specified syscalls, GDB will stop and announce the system
2493 call, both when it is called and when its call returns. This
2494 feature is currently available with a native GDB running on the
2495 Linux Kernel, under the following architectures: x86, x86_64,
2496 PowerPC and PowerPC64.
2498 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2500 Search memory for a sequence of bytes.
2502 maint set python print-stack
2503 maint show python print-stack
2504 Show a stack trace when an error is encountered in a Python script.
2507 Invoke CODE by passing it to the Python interpreter.
2512 These allow macros to be defined, undefined, and listed
2516 Show operating system information about processes.
2519 List the inferiors currently under GDB's control.
2522 Switch focus to inferior number NUM.
2525 Detach from inferior number NUM.
2528 Kill inferior number NUM.
2532 set spu stop-on-load
2533 show spu stop-on-load
2534 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2536 set spu auto-flush-cache
2537 show spu auto-flush-cache
2538 Control whether to automatically flush the software-managed cache
2539 during Cell/B.E. debugging.
2541 set sh calling-convention
2542 show sh calling-convention
2543 Control the calling convention used when calling SH target functions.
2546 show debug timestamp
2547 Control display of timestamps with GDB debugging output.
2549 set disassemble-next-line
2550 show disassemble-next-line
2551 Control display of disassembled source lines or instructions when
2554 set remote noack-packet
2555 show remote noack-packet
2556 Set/show the use of remote protocol QStartNoAckMode packet. See above
2557 under "New remote packets."
2559 set remote query-attached-packet
2560 show remote query-attached-packet
2561 Control use of remote protocol `qAttached' (query-attached) packet.
2563 set remote read-siginfo-object
2564 show remote read-siginfo-object
2565 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2568 set remote write-siginfo-object
2569 show remote write-siginfo-object
2570 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2573 set remote reverse-continue
2574 show remote reverse-continue
2575 Control use of remote protocol 'bc' (reverse-continue) packet.
2577 set remote reverse-step
2578 show remote reverse-step
2579 Control use of remote protocol 'bs' (reverse-step) packet.
2581 set displaced-stepping
2582 show displaced-stepping
2583 Control displaced stepping mode. Displaced stepping is a way to
2584 single-step over breakpoints without removing them from the debuggee.
2585 Also known as "out-of-line single-stepping".
2588 show debug displaced
2589 Control display of debugging info for displaced stepping.
2591 maint set internal-error
2592 maint show internal-error
2593 Control what GDB does when an internal error is detected.
2595 maint set internal-warning
2596 maint show internal-warning
2597 Control what GDB does when an internal warning is detected.
2602 Use a wrapper program to launch programs for debugging.
2604 set multiple-symbols (all|ask|cancel)
2605 show multiple-symbols
2606 The value of this variable can be changed to adjust the debugger behavior
2607 when an expression or a breakpoint location contains an ambiguous symbol
2608 name (an overloaded function name, for instance).
2610 set breakpoint always-inserted
2611 show breakpoint always-inserted
2612 Keep breakpoints always inserted in the target, as opposed to inserting
2613 them when resuming the target, and removing them when the target stops.
2614 This option can improve debugger performance on slow remote targets.
2616 set arm fallback-mode (arm|thumb|auto)
2617 show arm fallback-mode
2618 set arm force-mode (arm|thumb|auto)
2620 These commands control how ARM GDB determines whether instructions
2621 are ARM or Thumb. The default for both settings is auto, which uses
2622 the current CPSR value for instructions without symbols; previous
2623 versions of GDB behaved as if "set arm fallback-mode arm".
2625 set disable-randomization
2626 show disable-randomization
2627 Standalone programs run with the virtual address space randomization enabled
2628 by default on some platforms. This option keeps the addresses stable across
2629 multiple debugging sessions.
2633 Control whether other threads are stopped or not when some thread hits
2638 Requests that asynchronous execution is enabled in the target, if available.
2639 In this case, it's possible to resume target in the background, and interact
2640 with GDB while the target is running. "show target-async" displays the
2641 current state of asynchronous execution of the target.
2643 set target-wide-charset
2644 show target-wide-charset
2645 The target-wide-charset is the name of the character set that GDB
2646 uses when printing characters whose type is wchar_t.
2648 set tcp auto-retry (on|off)
2650 set tcp connect-timeout
2651 show tcp connect-timeout
2652 These commands allow GDB to retry failed TCP connections to a remote stub
2653 with a specified timeout period; this is useful if the stub is launched
2654 in parallel with GDB but may not be ready to accept connections immediately.
2656 set libthread-db-search-path
2657 show libthread-db-search-path
2658 Control list of directories which GDB will search for appropriate
2661 set schedule-multiple (on|off)
2662 show schedule-multiple
2663 Allow GDB to resume all threads of all processes or only threads of
2664 the current process.
2668 Use more aggressive caching for accesses to the stack. This improves
2669 performance of remote debugging (particularly backtraces) without
2670 affecting correctness.
2672 set interactive-mode (on|off|auto)
2673 show interactive-mode
2674 Control whether GDB runs in interactive mode (on) or not (off).
2675 When in interactive mode, GDB waits for the user to answer all
2676 queries. Otherwise, GDB does not wait and assumes the default
2677 answer. When set to auto (the default), GDB determines which
2678 mode to use based on the stdin settings.
2683 For program forks, this is replaced by the new more generic `info
2684 inferiors' command. To list checkpoints, you can still use the
2685 `info checkpoints' command, which was an alias for the `info forks'
2689 Replaced by the new `inferior' command. To switch between
2690 checkpoints, you can still use the `restart' command, which was an
2691 alias for the `fork' command.
2694 This is removed, since some targets don't have a notion of
2695 processes. To switch between processes, you can still use the
2696 `inferior' command using GDB's own inferior number.
2699 For program forks, this is replaced by the new more generic `kill
2700 inferior' command. To delete a checkpoint, you can still use the
2701 `delete checkpoint' command, which was an alias for the `delete
2705 For program forks, this is replaced by the new more generic `detach
2706 inferior' command. To detach a checkpoint, you can still use the
2707 `detach checkpoint' command, which was an alias for the `detach
2710 * New native configurations
2712 x86/x86_64 Darwin i[34567]86-*-darwin*
2714 x86_64 MinGW x86_64-*-mingw*
2718 Lattice Mico32 lm32-*
2719 x86 DICOS i[34567]86-*-dicos*
2720 x86_64 DICOS x86_64-*-dicos*
2723 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2724 (mingw32ce) debugging.
2730 These commands were actually not implemented on any target.
2732 *** Changes in GDB 6.8
2734 * New native configurations
2736 NetBSD/hppa hppa*-*netbsd*
2737 Xtensa GNU/Linux xtensa*-*-linux*
2741 NetBSD/hppa hppa*-*-netbsd*
2742 Xtensa GNU/Lunux xtensa*-*-linux*
2744 * Change in command line behavior -- corefiles vs. process ids.
2746 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2747 attaching to process NUMBER fails, GDB no longer attempts to open a
2748 core file named NUMBER. Attaching to a program using the -c option
2749 is no longer supported. Instead, use the '-p' or '--pid' options.
2751 * GDB can now be built as a native debugger for debugging Windows x86
2752 (mingw32) Portable Executable (PE) programs.
2754 * Pending breakpoints no longer change their number when their address
2757 * GDB now supports breakpoints with multiple locations,
2758 including breakpoints on C++ constructors, inside C++ templates,
2759 and in inlined functions.
2761 * GDB's ability to debug optimized code has been improved. GDB more
2762 accurately identifies function bodies and lexical blocks that occupy
2763 more than one contiguous range of addresses.
2765 * Target descriptions can now describe registers for PowerPC.
2767 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2768 registers on PowerPC targets.
2770 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2771 targets even when the libthread_db library is not available.
2773 * The GDB remote stub, gdbserver, now supports the new file transfer
2774 commands (remote put, remote get, and remote delete).
2776 * The GDB remote stub, gdbserver, now supports run and attach in
2777 extended-remote mode.
2779 * hppa*64*-*-hpux11* target broken
2780 The debugger is unable to start a program and fails with the following
2781 error: "Error trying to get information about dynamic linker".
2782 The gdb-6.7 release is also affected.
2784 * GDB now supports the --enable-targets= configure option to allow
2785 building a single GDB executable that supports multiple remote
2786 target architectures.
2788 * GDB now supports debugging C and C++ programs which use the
2789 Decimal Floating Point extension. In addition, the PowerPC target
2790 now has a set of pseudo-registers to inspect decimal float values
2791 stored in two consecutive float registers.
2793 * The -break-insert MI command can optionally create pending
2796 * Improved support for debugging Ada
2797 Many improvements to the Ada language support have been made. These
2799 - Better support for Ada2005 interface types
2800 - Improved handling of arrays and slices in general
2801 - Better support for Taft-amendment types
2802 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2804 - Improved command completion in Ada
2807 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2812 set print frame-arguments (all|scalars|none)
2813 show print frame-arguments
2814 The value of this variable can be changed to control which argument
2815 values should be printed by the debugger when displaying a frame.
2820 Transfer files to and from a remote target, and delete remote files.
2827 Transfer files to and from a remote target, and delete remote files.
2829 * New remote packets
2836 Open, close, read, write, and delete files on the remote system.
2839 Attach to an existing process on the remote system, in extended-remote
2843 Run a new process on the remote system, in extended-remote mode.
2845 *** Changes in GDB 6.7
2847 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2848 bfd, libiberty and opcodes, as revealed by static analysis donated by
2849 Coverity, Inc. (http://scan.coverity.com).
2851 * When looking up multiply-defined global symbols, GDB will now prefer the
2852 symbol definition in the current shared library if it was built using the
2853 -Bsymbolic linker option.
2855 * When the Text User Interface (TUI) is not configured, GDB will now
2856 recognize the -tui command-line option and print a message that the TUI
2859 * The GDB remote stub, gdbserver, now has lower overhead for high
2860 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2862 * GDB for MIPS targets now autodetects whether a remote target provides
2863 32-bit or 64-bit register values.
2865 * Support for C++ member pointers has been improved.
2867 * GDB now understands XML target descriptions, which specify the
2868 target's overall architecture. GDB can read a description from
2869 a local file or over the remote serial protocol.
2871 * Vectors of single-byte data use a new integer type which is not
2872 automatically displayed as character or string data.
2874 * The /s format now works with the print command. It displays
2875 arrays of single-byte integers and pointers to single-byte integers
2878 * Target descriptions can now describe target-specific registers,
2879 for architectures which have implemented the support (currently
2880 only ARM, M68K, and MIPS).
2882 * GDB and the GDB remote stub, gdbserver, now support the XScale
2885 * The GDB remote stub, gdbserver, has been updated to support
2886 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2887 has been rewritten to use the standard GDB remote protocol.
2889 * GDB can now step into C++ functions which are called through thunks.
2891 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2893 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2894 layout. It also supports a TextSeg= and DataSeg= response when only
2895 segment base addresses (rather than offsets) are available.
2897 * The /i format now outputs any trailing branch delay slot instructions
2898 immediately following the last instruction within the count specified.
2900 * The GDB remote protocol "T" stop reply packet now supports a
2901 "library" response. Combined with the new "qXfer:libraries:read"
2902 packet, this response allows GDB to debug shared libraries on targets
2903 where the operating system manages the list of loaded libraries (e.g.
2904 Windows and SymbianOS).
2906 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2907 (DLLs) on Windows and Windows CE targets.
2909 * GDB now supports a faster verification that a .debug file matches its binary
2910 according to its build-id signature, if the signature is present.
2916 Enable or disable hardware flow control (RTS/CTS) on the serial port
2917 when debugging using remote targets.
2919 set mem inaccessible-by-default
2920 show mem inaccessible-by-default
2921 If the target supplies a memory map, for instance via the remote
2922 protocol's "qXfer:memory-map:read" packet, setting this variable
2923 prevents GDB from accessing memory outside the memory map. This
2924 is useful for targets with memory mapped registers or which react
2925 badly to accesses of unmapped address space.
2927 set breakpoint auto-hw
2928 show breakpoint auto-hw
2929 If the target supplies a memory map, for instance via the remote
2930 protocol's "qXfer:memory-map:read" packet, setting this variable
2931 lets GDB use hardware breakpoints automatically for memory regions
2932 where it can not use software breakpoints. This covers both the
2933 "break" command and internal breakpoints used for other commands
2934 including "next" and "finish".
2937 catch exception unhandled
2938 Stop the program execution when Ada exceptions are raised.
2941 Stop the program execution when an Ada assertion failed.
2945 Set an alternate system root for target files. This is a more
2946 general version of "set solib-absolute-prefix", which is now
2947 an alias to "set sysroot".
2950 Provide extended SPU facility status information. This set of
2951 commands is available only when debugging the Cell/B.E. SPU
2954 * New native configurations
2956 OpenBSD/sh sh*-*openbsd*
2959 unset tdesc filename
2961 Use the specified local file as an XML target description, and do
2962 not query the target for its built-in description.
2966 OpenBSD/sh sh*-*-openbsd*
2967 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2968 Toshiba Media Processor mep-elf
2970 * New remote packets
2973 Ignore the specified signals; pass them directly to the debugged program
2974 without stopping other threads or reporting them to GDB.
2976 qXfer:features:read:
2977 Read an XML target description from the target, which describes its
2982 Read or write contents of an spufs file on the target system. These
2983 packets are available only on the Cell/B.E. SPU architecture.
2985 qXfer:libraries:read:
2986 Report the loaded shared libraries. Combined with new "T" packet
2987 response, this packet allows GDB to debug shared libraries on
2988 targets where the operating system manages the list of loaded
2989 libraries (e.g. Windows and SymbianOS).
2993 Support for these obsolete configurations has been removed.
3001 i[34567]86-*-lynxos*
3002 i[34567]86-*-netware*
3003 i[34567]86-*-sco3.2v5*
3004 i[34567]86-*-sco3.2v4*
3006 i[34567]86-*-sysv4.2*
3009 i[34567]86-*-unixware2*
3010 i[34567]86-*-unixware*
3019 * Other removed features
3026 Various m68k-only ROM monitors.
3033 Various Renesas ROM monitors and debugging interfaces for SH and
3038 Support for a Macraigor serial interface to on-chip debugging.
3039 GDB does not directly support the newer parallel or USB
3044 A debug information format. The predecessor to DWARF 2 and
3045 DWARF 3, which are still supported.
3047 Support for the HP aCC compiler on HP-UX/PA-RISC
3049 SOM-encapsulated symbolic debugging information, automatic
3050 invocation of pxdb, and the aCC custom C++ ABI. This does not
3051 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3052 with aCC can still be debugged on an assembly level.
3054 MIPS ".pdr" sections
3056 A MIPS-specific format used to describe stack frame layout
3057 in debugging information.
3061 GDB could work with an older version of Guile to debug
3062 the interpreter and Scheme programs running in it.
3064 set mips stack-arg-size
3065 set mips saved-gpreg-size
3067 Use "set mips abi" to control parameter passing for MIPS.
3069 *** Changes in GDB 6.6
3074 Cell Broadband Engine SPU spu-elf
3076 * GDB can now be configured as a cross-debugger targeting native Windows
3077 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3078 running on a Windows system over TCP/IP to debug Windows programs.
3080 * The GDB remote stub, gdbserver, has been updated to support Windows and
3081 Cygwin debugging. Both single-threaded and multi-threaded programs are
3084 * The "set trust-readonly-sections" command works again. This command was
3085 broken in GDB 6.3, 6.4, and 6.5.
3087 * The "load" command now supports writing to flash memory, if the remote
3088 stub provides the required support.
3090 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3091 longer requires symbolic debug information (e.g. DWARF-2).
3096 unset substitute-path
3097 show substitute-path
3098 Manage a list of substitution rules that GDB uses to rewrite the name
3099 of the directories where the sources are located. This can be useful
3100 for instance when the sources were moved to a different location
3101 between compilation and debugging.
3105 Print each CLI command as it is executed. Each command is prefixed with
3106 a number of `+' symbols representing the nesting depth.
3107 The source command now has a `-v' option to enable the same feature.
3111 The ARM Demon monitor support (RDP protocol, "target rdp").
3113 Kernel Object Display, an embedded debugging feature which only worked with
3114 an obsolete version of Cisco IOS.
3116 The 'set download-write-size' and 'show download-write-size' commands.
3118 * New remote packets
3121 Tell a stub about GDB client features, and request remote target features.
3122 The first feature implemented is PacketSize, which allows the target to
3123 specify the size of packets it can handle - to minimize the number of
3124 packets required and improve performance when connected to a remote
3128 Fetch an OS auxilliary vector from the remote stub. This packet is a
3129 more efficient replacement for qPart:auxv:read.
3131 qXfer:memory-map:read:
3132 Fetch a memory map from the remote stub, including information about
3133 RAM, ROM, and flash memory devices.
3138 Erase and program a flash memory device.
3140 * Removed remote packets
3143 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3144 used it, and only gdbserver implemented it.
3146 *** Changes in GDB 6.5
3150 Renesas M32C/M16C m32c-elf
3152 Morpho Technologies ms1 ms1-elf
3156 init-if-undefined Initialize a convenience variable, but
3157 only if it doesn't already have a value.
3159 The following commands are presently only implemented for native GNU/Linux:
3161 checkpoint Save a snapshot of the program state.
3163 restart <n> Return the program state to a
3164 previously saved state.
3166 info checkpoints List currently saved checkpoints.
3168 delete-checkpoint <n> Delete a previously saved checkpoint.
3170 set|show detach-on-fork Tell gdb whether to detach from a newly
3171 forked process, or to keep debugging it.
3173 info forks List forks of the user program that
3174 are available to be debugged.
3176 fork <n> Switch to debugging one of several
3177 forks of the user program that are
3178 available to be debugged.
3180 delete-fork <n> Delete a fork from the list of forks
3181 that are available to be debugged (and
3182 kill the forked process).
3184 detach-fork <n> Delete a fork from the list of forks
3185 that are available to be debugged (and
3186 allow the process to continue).
3190 Morpho Technologies ms2 ms1-elf
3192 * Improved Windows host support
3194 GDB now builds as a cross debugger hosted on i686-mingw32, including
3195 native console support, and remote communications using either
3196 network sockets or serial ports.
3198 * Improved Modula-2 language support
3200 GDB can now print most types in the Modula-2 syntax. This includes:
3201 basic types, set types, record types, enumerated types, range types,
3202 pointer types and ARRAY types. Procedure var parameters are correctly
3203 printed and hexadecimal addresses and character constants are also
3204 written in the Modula-2 syntax. Best results can be obtained by using
3205 GNU Modula-2 together with the -gdwarf-2 command line option.
3209 The ARM rdi-share module.
3211 The Netware NLM debug server.
3213 *** Changes in GDB 6.4
3215 * New native configurations
3217 OpenBSD/arm arm*-*-openbsd*
3218 OpenBSD/mips64 mips64-*-openbsd*
3222 Morpho Technologies ms1 ms1-elf
3224 * New command line options
3226 --batch-silent As for --batch, but totally silent.
3227 --return-child-result The debugger will exist with the same value
3228 the child (debugged) program exited with.
3229 --eval-command COMMAND, -ex COMMAND
3230 Execute a single GDB CLI command. This may be
3231 specified multiple times and in conjunction
3232 with the --command (-x) option.
3234 * Deprecated commands removed
3236 The following commands, that were deprecated in 2000, have been
3240 set|show arm disassembly-flavor set|show arm disassembler
3241 othernames set arm disassembler
3242 set|show remotedebug set|show debug remote
3243 set|show archdebug set|show debug arch
3244 set|show eventdebug set|show debug event
3247 * New BSD user-level threads support
3249 It is now possible to debug programs using the user-level threads
3250 library on OpenBSD and FreeBSD. Currently supported (target)
3253 FreeBSD/amd64 x86_64-*-freebsd*
3254 FreeBSD/i386 i386-*-freebsd*
3255 OpenBSD/i386 i386-*-openbsd*
3257 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3258 are not yet supported.
3260 * New support for Matsushita MN10300 w/sim added
3261 (Work in progress). mn10300-elf.
3263 * REMOVED configurations and files
3265 VxWorks and the XDR protocol *-*-vxworks
3266 Motorola MCORE mcore-*-*
3267 National Semiconductor NS32000 ns32k-*-*
3269 * New "set print array-indexes" command
3271 After turning this setting "on", GDB prints the index of each element
3272 when displaying arrays. The default is "off" to preserve the previous
3275 * VAX floating point support
3277 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3279 * User-defined command support
3281 In addition to using $arg0..$arg9 for argument passing, it is now possible
3282 to use $argc to determine now many arguments have been passed. See the
3283 section on user-defined commands in the user manual for more information.
3285 *** Changes in GDB 6.3:
3287 * New command line option
3289 GDB now accepts -l followed by a number to set the timeout for remote
3292 * GDB works with GCC -feliminate-dwarf2-dups
3294 GDB now supports a more compact representation of DWARF-2 debug
3295 information using DW_FORM_ref_addr references. These are produced
3296 by GCC with the option -feliminate-dwarf2-dups and also by some
3297 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3298 to use -feliminate-dwarf2-dups.
3300 * Internationalization
3302 When supported by the host system, GDB will be built with
3303 internationalization (libintl). The task of marking up the sources is
3304 continued, we're looking forward to our first translation.
3308 Initial support for debugging programs compiled with the GNAT
3309 implementation of the Ada programming language has been integrated
3310 into GDB. In this release, support is limited to expression evaluation.
3312 * New native configurations
3314 GNU/Linux/m32r m32r-*-linux-gnu
3318 GDB's remote protocol now includes support for the 'p' packet. This
3319 packet is used to fetch individual registers from a remote inferior.
3321 * END-OF-LIFE registers[] compatibility module
3323 GDB's internal register infrastructure has been completely rewritten.
3324 The new infrastructure making possible the implementation of key new
3325 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3328 GDB 6.3 will be the last release to include the the registers[]
3329 compatibility module that allowed out-of-date configurations to
3330 continue to work. This change directly impacts the following
3340 powerpc bdm protocol
3342 Unless there is activity to revive these configurations, they will be
3343 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3345 * OBSOLETE configurations and files
3347 Configurations that have been declared obsolete in this release have
3348 been commented out. Unless there is activity to revive these
3349 configurations, the next release of GDB will have their sources
3350 permanently REMOVED.
3359 *** Changes in GDB 6.2.1:
3361 * MIPS `break main; run' gave an heuristic-fence-post warning
3363 When attempting to run even a simple program, a warning about
3364 heuristic-fence-post being hit would be reported. This problem has
3367 * MIPS IRIX 'long double' crashed GDB
3369 When examining a long double variable, GDB would get a segmentation
3370 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3371 IRIX long double values).
3375 A bug in the VAX stack code was causing problems with the "next"
3376 command. This problem has been fixed.
3378 *** Changes in GDB 6.2:
3380 * Fix for ``many threads''
3382 On GNU/Linux systems that use the NPTL threads library, a program
3383 rapidly creating and deleting threads would confuse GDB leading to the
3386 ptrace: No such process.
3387 thread_db_get_info: cannot get thread info: generic error
3389 This problem has been fixed.
3391 * "-async" and "-noasync" options removed.
3393 Support for the broken "-noasync" option has been removed (it caused
3396 * New ``start'' command.
3398 This command runs the program until the begining of the main procedure.
3400 * New BSD Kernel Data Access Library (libkvm) interface
3402 Using ``target kvm'' it is now possible to debug kernel core dumps and
3403 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3404 platforms. Currently supported (native-only) configurations are:
3406 FreeBSD/amd64 x86_64-*-freebsd*
3407 FreeBSD/i386 i?86-*-freebsd*
3408 NetBSD/i386 i?86-*-netbsd*
3409 NetBSD/m68k m68*-*-netbsd*
3410 NetBSD/sparc sparc-*-netbsd*
3411 OpenBSD/amd64 x86_64-*-openbsd*
3412 OpenBSD/i386 i?86-*-openbsd*
3413 OpenBSD/m68k m68*-openbsd*
3414 OpenBSD/sparc sparc-*-openbsd*
3416 * Signal trampoline code overhauled
3418 Many generic problems with GDB's signal handling code have been fixed.
3419 These include: backtraces through non-contiguous stacks; recognition
3420 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3421 call; backtrace through a signal trampoline; step into and out of
3422 signal handlers; and single-stepping in the signal trampoline.
3424 Please note that kernel bugs are a limiting factor here. These
3425 features have been shown to work on an s390 GNU/Linux system that
3426 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3428 * Cygwin support for DWARF 2 added.
3430 * New native configurations
3432 GNU/Linux/hppa hppa*-*-linux*
3433 OpenBSD/hppa hppa*-*-openbsd*
3434 OpenBSD/m68k m68*-*-openbsd*
3435 OpenBSD/m88k m88*-*-openbsd*
3436 OpenBSD/powerpc powerpc-*-openbsd*
3437 NetBSD/vax vax-*-netbsd*
3438 OpenBSD/vax vax-*-openbsd*
3440 * END-OF-LIFE frame compatibility module
3442 GDB's internal frame infrastructure has been completely rewritten.
3443 The new infrastructure making it possible to support key new features
3444 including DWARF 2 Call Frame Information. To aid in the task of
3445 migrating old configurations to this new infrastructure, a
3446 compatibility module, that allowed old configurations to continue to
3447 work, was also included.
3449 GDB 6.2 will be the last release to include this frame compatibility
3450 module. This change directly impacts the following configurations:
3460 Unless there is activity to revive these configurations, they will be
3461 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3463 * REMOVED configurations and files
3465 Sun 3, running SunOS 3 m68*-*-sunos3*
3466 Sun 3, running SunOS 4 m68*-*-sunos4*
3467 Sun 2, running SunOS 3 m68000-*-sunos3*
3468 Sun 2, running SunOS 4 m68000-*-sunos4*
3469 Motorola 680x0 running LynxOS m68*-*-lynxos*
3470 AT&T 3b1/Unix pc m68*-att-*
3471 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3472 decstation mips-dec-* mips-little-*
3473 riscos mips-*-riscos* mips-*-sysv*
3474 sonymips mips-sony-*
3475 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3477 *** Changes in GDB 6.1.1:
3479 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3481 The TUI (Text-mode User Interface) is now built as part of a default
3482 GDB configuration. It is enabled by either selecting the TUI with the
3483 command line option "-i=tui" or by running the separate "gdbtui"
3484 program. For more information on the TUI, see the manual "Debugging
3487 * Pending breakpoint support (also included in GDB 6.1)
3489 Support has been added to allow you to specify breakpoints in shared
3490 libraries that have not yet been loaded. If a breakpoint location
3491 cannot be found, and the "breakpoint pending" option is set to auto,
3492 GDB queries you if you wish to make the breakpoint pending on a future
3493 shared-library load. If and when GDB resolves the breakpoint symbol,
3494 the pending breakpoint is removed as one or more regular breakpoints
3497 Pending breakpoints are very useful for GCJ Java debugging.
3499 * Fixed ISO-C build problems
3501 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3502 non ISO-C code that stopped them being built using a more strict ISO-C
3503 compiler (e.g., IBM's C compiler).
3505 * Fixed build problem on IRIX 5
3507 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3508 wasn't able to compile compile on an IRIX 5 system.
3510 * Added execute permission to gdb/gdbserver/configure
3512 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3513 permission. This bug would cause configure to fail on a number of
3514 systems (Solaris, IRIX). Ref: server/519.
3516 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3518 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3519 has been updated to use constant array sizes.
3521 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3523 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3524 its generated DWARF Call Frame Info. This encoding was causing GDB to
3525 panic, that panic has been fixed. Ref: gdb/1628.
3527 * Fixed a problem when examining parameters in shared library code.
3529 When examining parameters in optimized shared library code generated
3530 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3531 not available''. GDB now correctly displays the variable's value.
3533 *** Changes in GDB 6.1:
3535 * Removed --with-mmalloc
3537 Support for the mmalloc memory manager has been removed, as it
3538 conflicted with the internal gdb byte cache.
3540 * Changes in AMD64 configurations
3542 The AMD64 target now includes the %cs and %ss registers. As a result
3543 the AMD64 remote protocol has changed; this affects the floating-point
3544 and SSE registers. If you rely on those registers for your debugging,
3545 you should upgrade gdbserver on the remote side.
3547 * Revised SPARC target
3549 The SPARC target has been completely revised, incorporating the
3550 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3551 support for LynxOS and SunOS 4 has been dropped. Calling functions
3552 from within GDB on operating systems with a non-executable stack
3553 (Solaris, OpenBSD) now works.
3557 GDB has a new C++ demangler which does a better job on the mangled
3558 names generated by current versions of g++. It also runs faster, so
3559 with this and other changes gdb should now start faster on large C++
3562 * DWARF 2 Location Expressions
3564 GDB support for location expressions has been extended to support function
3565 arguments and frame bases. Older versions of GDB could crash when they
3568 * C++ nested types and namespaces
3570 GDB's support for nested types and namespaces in C++ has been
3571 improved, especially if you use the DWARF 2 debugging format. (This
3572 is the default for recent versions of GCC on most platforms.)
3573 Specifically, if you have a class "Inner" defined within a class or
3574 namespace "Outer", then GDB realizes that the class's name is
3575 "Outer::Inner", not simply "Inner". This should greatly reduce the
3576 frequency of complaints about not finding RTTI symbols. In addition,
3577 if you are stopped at inside of a function defined within a namespace,
3578 GDB modifies its name lookup accordingly.
3580 * New native configurations
3582 NetBSD/amd64 x86_64-*-netbsd*
3583 OpenBSD/amd64 x86_64-*-openbsd*
3584 OpenBSD/alpha alpha*-*-openbsd*
3585 OpenBSD/sparc sparc-*-openbsd*
3586 OpenBSD/sparc64 sparc64-*-openbsd*
3588 * New debugging protocols
3590 M32R with SDI protocol m32r-*-elf*
3592 * "set prompt-escape-char" command deleted.
3594 The command "set prompt-escape-char" has been deleted. This command,
3595 and its very obscure effet on GDB's prompt, was never documented,
3596 tested, nor mentioned in the NEWS file.
3598 * OBSOLETE configurations and files
3600 Configurations that have been declared obsolete in this release have
3601 been commented out. Unless there is activity to revive these
3602 configurations, the next release of GDB will have their sources
3603 permanently REMOVED.
3605 Sun 3, running SunOS 3 m68*-*-sunos3*
3606 Sun 3, running SunOS 4 m68*-*-sunos4*
3607 Sun 2, running SunOS 3 m68000-*-sunos3*
3608 Sun 2, running SunOS 4 m68000-*-sunos4*
3609 Motorola 680x0 running LynxOS m68*-*-lynxos*
3610 AT&T 3b1/Unix pc m68*-att-*
3611 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3612 decstation mips-dec-* mips-little-*
3613 riscos mips-*-riscos* mips-*-sysv*
3614 sonymips mips-sony-*
3615 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3617 * REMOVED configurations and files
3619 SGI Irix-4.x mips-sgi-irix4 or iris4
3620 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3621 Z8000 simulator z8k-zilog-none or z8ksim
3622 Matsushita MN10200 w/simulator mn10200-*-*
3623 H8/500 simulator h8500-hitachi-hms or h8500hms
3624 HP/PA running BSD hppa*-*-bsd*
3625 HP/PA running OSF/1 hppa*-*-osf*
3626 HP/PA Pro target hppa*-*-pro*
3627 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3628 386BSD i[3456]86-*-bsd*
3629 Sequent family i[3456]86-sequent-sysv4*
3630 i[3456]86-sequent-sysv*
3631 i[3456]86-sequent-bsd*
3632 SPARC running LynxOS sparc-*-lynxos*
3633 SPARC running SunOS 4 sparc-*-sunos4*
3634 Tsqware Sparclet sparclet-*-*
3635 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3637 *** Changes in GDB 6.0:
3641 Support for debugging the Objective-C programming language has been
3642 integrated into GDB.
3644 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3646 DWARF 2's Call Frame Information makes available compiler generated
3647 information that more exactly describes the program's run-time stack.
3648 By using this information, GDB is able to provide more robust stack
3651 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3652 have been updated to use a new backtrace mechanism which includes
3653 DWARF 2 CFI support.
3657 GDB's remote protocol has been extended to include support for hosted
3658 file I/O (where the remote target uses GDB's file system). See GDB's
3659 remote protocol documentation for details.
3661 * All targets using the new architecture framework.
3663 All of GDB's targets have been updated to use the new internal
3664 architecture framework. The way is now open for future GDB releases
3665 to include cross-architecture native debugging support (i386 on amd64,
3668 * GNU/Linux's Thread Local Storage (TLS)
3670 GDB now includes support for for the GNU/Linux implementation of
3671 per-thread variables.
3673 * GNU/Linux's Native POSIX Thread Library (NPTL)
3675 GDB's thread code has been updated to work with either the new
3676 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3678 * Separate debug info.
3680 GDB, in conjunction with BINUTILS, now supports a mechanism for
3681 automatically loading debug information from a separate file. Instead
3682 of shipping full debug and non-debug versions of system libraries,
3683 system integrators can now instead ship just the stripped libraries
3684 and optional debug files.
3686 * DWARF 2 Location Expressions
3688 DWARF 2 Location Expressions allow the compiler to more completely
3689 describe the location of variables (even in optimized code) to the
3692 GDB now includes preliminary support for location expressions (support
3693 for DW_OP_piece is still missing).
3697 A number of long standing bugs that caused GDB to die while starting a
3698 Java application have been fixed. GDB's Java support is now
3699 considered "useable".
3701 * GNU/Linux support for fork, vfork, and exec.
3703 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3704 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3707 * GDB supports logging output to a file
3709 There are two new commands, "set logging" and "show logging", which can be
3710 used to capture GDB's output to a file.
3712 * The meaning of "detach" has changed for gdbserver
3714 The "detach" command will now resume the application, as documented. To
3715 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3718 * d10v, m68hc11 `regs' command deprecated
3720 The `info registers' command has been updated so that it displays the
3721 registers using a format identical to the old `regs' command.
3725 A new command, "maint set profile on/off", has been added. This command can
3726 be used to enable or disable profiling while running GDB, to profile a
3727 session or a set of commands. In addition there is a new configure switch,
3728 "--enable-profiling", which will cause GDB to be compiled with profiling
3729 data, for more informative profiling results.
3731 * Default MI syntax changed to "mi2".
3733 The default MI (machine interface) syntax, enabled by the command line
3734 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3735 "mi1", can be enabled by specifying the option "-i=mi1".
3737 Support for the original "mi0" syntax (included in GDB 5.0) has been
3740 Fix for gdb/192: removed extraneous space when displaying frame level.
3741 Fix for gdb/672: update changelist is now output in mi list format.
3742 Fix for gdb/702: a -var-assign that updates the value now shows up
3743 in a subsequent -var-update.
3745 * New native configurations.
3747 FreeBSD/amd64 x86_64-*-freebsd*
3749 * Multi-arched targets.
3751 HP/PA HPUX11 hppa*-*-hpux*
3752 Renesas M32R/D w/simulator m32r-*-elf*
3754 * OBSOLETE configurations and files
3756 Configurations that have been declared obsolete in this release have
3757 been commented out. Unless there is activity to revive these
3758 configurations, the next release of GDB will have their sources
3759 permanently REMOVED.
3761 Z8000 simulator z8k-zilog-none or z8ksim
3762 Matsushita MN10200 w/simulator mn10200-*-*
3763 H8/500 simulator h8500-hitachi-hms or h8500hms
3764 HP/PA running BSD hppa*-*-bsd*
3765 HP/PA running OSF/1 hppa*-*-osf*
3766 HP/PA Pro target hppa*-*-pro*
3767 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3768 Sequent family i[3456]86-sequent-sysv4*
3769 i[3456]86-sequent-sysv*
3770 i[3456]86-sequent-bsd*
3771 Tsqware Sparclet sparclet-*-*
3772 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3774 * REMOVED configurations and files
3777 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3778 IBM AIX PS/2 i[3456]86-*-aix
3779 i386 running Mach 3.0 i[3456]86-*-mach3*
3780 i386 running Mach i[3456]86-*-mach*
3781 i386 running OSF/1 i[3456]86-*osf1mk*
3782 HP/Apollo 68k Family m68*-apollo*-sysv*,
3784 m68*-hp-bsd*, m68*-hp-hpux*
3785 Argonaut Risc Chip (ARC) arc-*-*
3786 Mitsubishi D30V d30v-*-*
3787 Fujitsu FR30 fr30-*-elf*
3788 OS/9000 i[34]86-*-os9k
3789 I960 with MON960 i960-*-coff
3791 * MIPS $fp behavior changed
3793 The convenience variable $fp, for the MIPS, now consistently returns
3794 the address of the current frame's base. Previously, depending on the
3795 context, $fp could refer to either $sp or the current frame's base
3796 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3797 The GNU Source-Level Debugger''.
3799 *** Changes in GDB 5.3:
3801 * GNU/Linux shared library multi-threaded performance improved.
3803 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3804 `/proc', in preference to `ptrace' for memory reads. This may result
3805 in an improvement in the start-up time of multi-threaded, shared
3806 library applications when run under GDB. One GDB user writes: ``loads
3807 shared libs like mad''.
3809 * ``gdbserver'' now supports multi-threaded applications on some targets
3811 Support for debugging multi-threaded applications which use
3812 the GNU/Linux LinuxThreads package has been added for
3813 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3814 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3816 * GDB now supports C/C++ preprocessor macros.
3818 GDB now expands preprocessor macro invocations in C/C++ expressions,
3819 and provides various commands for showing macro definitions and how
3822 The new command `macro expand EXPRESSION' expands any macro
3823 invocations in expression, and shows the result.
3825 The new command `show macro MACRO-NAME' shows the definition of the
3826 macro named MACRO-NAME, and where it was defined.
3828 Most compilers don't include information about macros in the debugging
3829 information by default. In GCC 3.1, for example, you need to compile
3830 your program with the options `-gdwarf-2 -g3'. If the macro
3831 information is present in the executable, GDB will read it.
3833 * Multi-arched targets.
3835 DEC Alpha (partial) alpha*-*-*
3836 DEC VAX (partial) vax-*-*
3838 National Semiconductor NS32000 (partial) ns32k-*-*
3839 Motorola 68000 (partial) m68k-*-*
3840 Motorola MCORE mcore-*-*
3844 Fujitsu FRV architecture added by Red Hat frv*-*-*
3847 * New native configurations
3849 Alpha NetBSD alpha*-*-netbsd*
3850 SH NetBSD sh*-*-netbsdelf*
3851 MIPS NetBSD mips*-*-netbsd*
3852 UltraSPARC NetBSD sparc64-*-netbsd*
3854 * OBSOLETE configurations and files
3856 Configurations that have been declared obsolete in this release have
3857 been commented out. Unless there is activity to revive these
3858 configurations, the next release of GDB will have their sources
3859 permanently REMOVED.
3861 Mitsubishi D30V d30v-*-*
3862 OS/9000 i[34]86-*-os9k
3863 IBM AIX PS/2 i[3456]86-*-aix
3864 Fujitsu FR30 fr30-*-elf*
3865 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3866 Argonaut Risc Chip (ARC) arc-*-*
3867 i386 running Mach 3.0 i[3456]86-*-mach3*
3868 i386 running Mach i[3456]86-*-mach*
3869 i386 running OSF/1 i[3456]86-*osf1mk*
3870 HP/Apollo 68k Family m68*-apollo*-sysv*,
3872 m68*-hp-bsd*, m68*-hp-hpux*
3873 I960 with MON960 i960-*-coff
3875 * OBSOLETE languages
3877 CHILL, a Pascal like language used by telecommunications companies.
3879 * REMOVED configurations and files
3881 AMD 29k family via UDI a29k-amd-udi, udi29k
3882 A29K VxWorks a29k-*-vxworks
3883 AMD 29000 embedded, using EBMON a29k-none-none
3884 AMD 29000 embedded with COFF a29k-none-coff
3885 AMD 29000 embedded with a.out a29k-none-aout
3887 testsuite/gdb.hp/gdb.threads-hp/ directory
3889 * New command "set max-user-call-depth <nnn>"
3891 This command allows the user to limit the call depth of user-defined
3892 commands. The default is 1024.
3894 * Changes in FreeBSD/i386 native debugging.
3896 Support for the "generate-core-file" has been added.
3898 * New commands "dump", "append", and "restore".
3900 These commands allow data to be copied from target memory
3901 to a bfd-format or binary file (dump and append), and back
3902 from a file into memory (restore).
3904 * Improved "next/step" support on multi-processor Alpha Tru64.
3906 The previous single-step mechanism could cause unpredictable problems,
3907 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3908 of a software single-step mechanism prevents this.
3910 *** Changes in GDB 5.2.1:
3918 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3919 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3920 Fix, by Joel Brobecker imported from mainline.
3922 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3923 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3924 Fix, by Fred Fish, imported from mainline.
3926 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3927 Surprisingly enough, it works now.
3928 By Michal Ludvig, imported from mainline.
3930 i386 hardware watchpoint support:
3931 avoid misses on second run for some targets.
3932 By Pierre Muller, imported from mainline.
3934 *** Changes in GDB 5.2:
3936 * New command "set trust-readonly-sections on[off]".
3938 This command is a hint that tells gdb that read-only sections
3939 really are read-only (ie. that their contents will not change).
3940 In this mode, gdb will go to the object file rather than the
3941 target to read memory from read-only sections (such as ".text").
3942 This can be a significant performance improvement on some
3943 (notably embedded) targets.
3945 * New command "generate-core-file" (or "gcore").
3947 This new gdb command allows the user to drop a core file of the child
3948 process state at any time. So far it's been implemented only for
3949 GNU/Linux and Solaris, but should be relatively easily ported to other
3950 hosts. Argument is core file name (defaults to core.<pid>).
3952 * New command line option
3954 GDB now accepts --pid or -p followed by a process id.
3956 * Change in command line behavior -- corefiles vs. process ids.
3958 There is a subtle behavior in the way in which GDB handles
3959 command line arguments. The first non-flag argument is always
3960 a program to debug, but the second non-flag argument may either
3961 be a corefile or a process id. Previously, GDB would attempt to
3962 open the second argument as a corefile, and if that failed, would
3963 issue a superfluous error message and then attempt to attach it as
3964 a process. Now, if the second argument begins with a non-digit,
3965 it will be treated as a corefile. If it begins with a digit,
3966 GDB will attempt to attach it as a process, and if no such process
3967 is found, will then attempt to open it as a corefile.
3969 * Changes in ARM configurations.
3971 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3972 configuration is fully multi-arch.
3974 * New native configurations
3976 ARM NetBSD arm*-*-netbsd*
3977 x86 OpenBSD i[3456]86-*-openbsd*
3978 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3979 Sparc64 running FreeBSD sparc64-*-freebsd*
3983 Sanyo XStormy16 xstormy16-elf
3985 * OBSOLETE configurations and files
3987 Configurations that have been declared obsolete in this release have
3988 been commented out. Unless there is activity to revive these
3989 configurations, the next release of GDB will have their sources
3990 permanently REMOVED.
3992 AMD 29k family via UDI a29k-amd-udi, udi29k
3993 A29K VxWorks a29k-*-vxworks
3994 AMD 29000 embedded, using EBMON a29k-none-none
3995 AMD 29000 embedded with COFF a29k-none-coff
3996 AMD 29000 embedded with a.out a29k-none-aout
3998 testsuite/gdb.hp/gdb.threads-hp/ directory
4000 * REMOVED configurations and files
4002 TI TMS320C80 tic80-*-*
4004 PowerPC Solaris powerpcle-*-solaris*
4005 PowerPC Windows NT powerpcle-*-cygwin32
4006 PowerPC Netware powerpc-*-netware*
4007 Harris/CXUX m88k m88*-harris-cxux*
4008 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4009 ns32k-utek-sysv* ns32k-utek-*
4010 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4011 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4012 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4013 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4014 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4016 * Changes to command line processing
4018 The new `--args' feature can be used to specify command-line arguments
4019 for the inferior from gdb's command line.
4021 * Changes to key bindings
4023 There is a new `operate-and-get-next' function bound to `C-o'.
4025 *** Changes in GDB 5.1.1
4027 Fix compile problem on DJGPP.
4029 Fix a problem with floating-point registers on the i386 being
4032 Fix to stop GDB crashing on .debug_str debug info.
4034 Numerous documentation fixes.
4036 Numerous testsuite fixes.
4038 *** Changes in GDB 5.1:
4040 * New native configurations
4042 Alpha FreeBSD alpha*-*-freebsd*
4043 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4044 MIPS GNU/Linux mips*-*-linux*
4045 MIPS SGI Irix 6.x mips*-sgi-irix6*
4046 ia64 AIX ia64-*-aix*
4047 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4051 Motorola 68HC11 and 68HC12 m68hc11-elf
4053 UltraSparc running GNU/Linux sparc64-*-linux*
4055 * OBSOLETE configurations and files
4057 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4058 Harris/CXUX m88k m88*-harris-cxux*
4059 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4060 ns32k-utek-sysv* ns32k-utek-*
4061 TI TMS320C80 tic80-*-*
4063 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4064 PowerPC Solaris powerpcle-*-solaris*
4065 PowerPC Windows NT powerpcle-*-cygwin32
4066 PowerPC Netware powerpc-*-netware*
4067 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4068 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4069 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4070 Apple Macintosh (MPW) host N/A
4072 stuff.c (Program to stuff files into a specially prepared space in kdb)
4073 kdb-start.c (Main loop for the standalone kernel debugger)
4075 Configurations that have been declared obsolete in this release have
4076 been commented out. Unless there is activity to revive these
4077 configurations, the next release of GDB will have their sources
4078 permanently REMOVED.
4080 * REMOVED configurations and files
4082 Altos 3068 m68*-altos-*
4083 Convex c1-*-*, c2-*-*
4085 ARM RISCix arm-*-* (as host)
4089 * GDB has been converted to ISO C.
4091 GDB's source code has been converted to ISO C. In particular, the
4092 sources are fully protoized, and rely on standard headers being
4097 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4099 * The MI enabled by default.
4101 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4102 revised and enabled by default. Packages which use GDB as a debugging
4103 engine behind a UI or another front end are encouraged to switch to
4104 using the GDB/MI interface, instead of the old annotations interface
4105 which is now deprecated.
4107 * Support for debugging Pascal programs.
4109 GDB now includes support for debugging Pascal programs. The following
4110 main features are supported:
4112 - Pascal-specific data types such as sets;
4114 - automatic recognition of Pascal sources based on file-name
4117 - Pascal-style display of data types, variables, and functions;
4119 - a Pascal expression parser.
4121 However, some important features are not yet supported.
4123 - Pascal string operations are not supported at all;
4125 - there are some problems with boolean types;
4127 - Pascal type hexadecimal constants are not supported
4128 because they conflict with the internal variables format;
4130 - support for Pascal objects and classes is not full yet;
4132 - unlike Pascal, GDB is case-sensitive for symbol names.
4134 * Changes in completion.
4136 Commands such as `shell', `run' and `set args', which pass arguments
4137 to inferior programs, now complete on file names, similar to what
4138 users expect at the shell prompt.
4140 Commands which accept locations, such as `disassemble', `print',
4141 `breakpoint', `until', etc. now complete on filenames as well as
4142 program symbols. Thus, if you type "break foob TAB", and the source
4143 files linked into the programs include `foobar.c', that file name will
4144 be one of the candidates for completion. However, file names are not
4145 considered for completion after you typed a colon that delimits a file
4146 name from a name of a function in that file, as in "break foo.c:bar".
4148 `set demangle-style' completes on available demangling styles.
4150 * New platform-independent commands:
4152 It is now possible to define a post-hook for a command as well as a
4153 hook that runs before the command. For more details, see the
4154 documentation of `hookpost' in the GDB manual.
4156 * Changes in GNU/Linux native debugging.
4158 Support for debugging multi-threaded programs has been completely
4159 revised for all platforms except m68k and sparc. You can now debug as
4160 many threads as your system allows you to have.
4162 Attach/detach is supported for multi-threaded programs.
4164 Support for SSE registers was added for x86. This doesn't work for
4165 multi-threaded programs though.
4167 * Changes in MIPS configurations.
4169 Multi-arch support is enabled for all MIPS configurations.
4171 GDB can now be built as native debugger on SGI Irix 6.x systems for
4172 debugging n32 executables. (Debugging 64-bit executables is not yet
4175 * Unified support for hardware watchpoints in all x86 configurations.
4177 Most (if not all) native x86 configurations support hardware-assisted
4178 breakpoints and watchpoints in a unified manner. This support
4179 implements debug register sharing between watchpoints, which allows to
4180 put a virtually infinite number of watchpoints on the same address,
4181 and also supports watching regions up to 16 bytes with several debug
4184 The new maintenance command `maintenance show-debug-regs' toggles
4185 debugging print-outs in functions that insert, remove, and test
4186 watchpoints and hardware breakpoints.
4188 * Changes in the DJGPP native configuration.
4190 New command ``info dos sysinfo'' displays assorted information about
4191 the CPU, OS, memory, and DPMI server.
4193 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4194 display information about segment descriptors stored in GDT, LDT, and
4197 New commands ``info dos pde'' and ``info dos pte'' display entries
4198 from Page Directory and Page Tables (for now works with CWSDPMI only).
4199 New command ``info dos address-pte'' displays the Page Table entry for
4200 a given linear address.
4202 GDB can now pass command lines longer than 126 characters to the
4203 program being debugged (requires an update to the libdbg.a library
4204 which is part of the DJGPP development kit).
4206 DWARF2 debug info is now supported.
4208 It is now possible to `step' and `next' through calls to `longjmp'.
4210 * Changes in documentation.
4212 All GDB documentation was converted to GFDL, the GNU Free
4213 Documentation License.
4215 Tracepoints-related commands are now fully documented in the GDB
4218 TUI, the Text-mode User Interface, is now documented in the manual.
4220 Tracepoints-related commands are now fully documented in the GDB
4223 The "GDB Internals" manual now has an index. It also includes
4224 documentation of `ui_out' functions, GDB coding standards, x86
4225 hardware watchpoints, and memory region attributes.
4227 * GDB's version number moved to ``version.in''
4229 The Makefile variable VERSION has been replaced by the file
4230 ``version.in''. People creating GDB distributions should update the
4231 contents of this file.
4235 GUD support is now a standard part of the EMACS distribution.
4237 *** Changes in GDB 5.0:
4239 * Improved support for debugging FP programs on x86 targets
4241 Unified and much-improved support for debugging floating-point
4242 programs on all x86 targets. In particular, ``info float'' now
4243 displays the FP registers in the same format on all x86 targets, with
4244 greater level of detail.
4246 * Improvements and bugfixes in hardware-assisted watchpoints
4248 It is now possible to watch array elements, struct members, and
4249 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4250 on x86 targets no longer erroneously trigger when the address is
4253 * Improvements in the native DJGPP version of GDB
4255 The distribution now includes all the scripts and auxiliary files
4256 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4257 machines ``out of the box''.
4259 The DJGPP version can now debug programs that use signals. It is
4260 possible to catch signals that happened in the debuggee, deliver
4261 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4262 would kill the program being debugged.) Programs that hook hardware
4263 interrupts (keyboard, timer, etc.) can also be debugged.
4265 It is now possible to debug DJGPP programs that redirect their
4266 standard handles or switch them to raw (as opposed to cooked) mode, or
4267 even close them. The command ``run < foo > bar'' works as expected,
4268 and ``info terminal'' reports useful information about the debuggee's
4269 terminal, including raw/cooked mode, redirection, etc.
4271 The DJGPP version now uses termios functions for console I/O, which
4272 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4275 DOS-style file names with drive letters are now fully supported by
4278 It is now possible to debug DJGPP programs that switch their working
4279 directory. It is also possible to rerun the debuggee any number of
4280 times without restarting GDB; thus, you can use the same setup,
4281 breakpoints, etc. for many debugging sessions.
4283 * New native configurations
4285 ARM GNU/Linux arm*-*-linux*
4286 PowerPC GNU/Linux powerpc-*-linux*
4290 Motorola MCore mcore-*-*
4291 x86 VxWorks i[3456]86-*-vxworks*
4292 PowerPC VxWorks powerpc-*-vxworks*
4293 TI TMS320C80 tic80-*-*
4295 * OBSOLETE configurations
4297 Altos 3068 m68*-altos-*
4298 Convex c1-*-*, c2-*-*
4300 ARM RISCix arm-*-* (as host)
4303 Configurations that have been declared obsolete will be commented out,
4304 but the code will be left in place. If there is no activity to revive
4305 these configurations before the next release of GDB, the sources will
4306 be permanently REMOVED.
4308 * Gould support removed
4310 Support for the Gould PowerNode and NP1 has been removed.
4312 * New features for SVR4
4314 On SVR4 native platforms (such as Solaris), if you attach to a process
4315 without first loading a symbol file, GDB will now attempt to locate and
4316 load symbols from the running process's executable file.
4318 * Many C++ enhancements
4320 C++ support has been greatly improved. Overload resolution now works properly
4321 in almost all cases. RTTI support is on the way.
4323 * Remote targets can connect to a sub-program
4325 A popen(3) style serial-device has been added. This device starts a
4326 sub-process (such as a stand-alone simulator) and then communicates
4327 with that. The sub-program to run is specified using the syntax
4328 ``|<program> <args>'' vis:
4330 (gdb) set remotedebug 1
4331 (gdb) target extended-remote |mn10300-elf-sim program-args
4333 * MIPS 64 remote protocol
4335 A long standing bug in the mips64 remote protocol where by GDB
4336 expected certain 32 bit registers (ex SR) to be transfered as 32
4337 instead of 64 bits has been fixed.
4339 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4340 added to provide backward compatibility with older versions of GDB.
4342 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4344 The command ``set remotebinarydownload'' command has been replaced by
4345 ``set remote X-packet''. Other commands in ``set remote'' family
4346 include ``set remote P-packet''.
4348 * Breakpoint commands accept ranges.
4350 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4351 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4352 ``tracepoint passcount'' also accepts a range of tracepoints.
4354 * ``apropos'' command added.
4356 The ``apropos'' command searches through command names and
4357 documentation strings, printing out matches, making it much easier to
4358 try to find a command that does what you are looking for.
4362 A new machine oriented interface (MI) has been added to GDB. This
4363 interface is designed for debug environments running GDB as a separate
4364 process. This is part of the long term libGDB project. See the
4365 "GDB/MI" chapter of the GDB manual for further information. It can be
4366 enabled by configuring with:
4368 .../configure --enable-gdbmi
4370 *** Changes in GDB-4.18:
4372 * New native configurations
4374 HP-UX 10.20 hppa*-*-hpux10.20
4375 HP-UX 11.x hppa*-*-hpux11.0*
4376 M68K GNU/Linux m68*-*-linux*
4380 Fujitsu FR30 fr30-*-elf*
4381 Intel StrongARM strongarm-*-*
4382 Mitsubishi D30V d30v-*-*
4384 * OBSOLETE configurations
4386 Gould PowerNode, NP1 np1-*-*, pn-*-*
4388 Configurations that have been declared obsolete will be commented out,
4389 but the code will be left in place. If there is no activity to revive
4390 these configurations before the next release of GDB, the sources will
4391 be permanently REMOVED.
4395 As a compatibility experiment, GDB's source files buildsym.h and
4396 buildsym.c have been converted to pure standard C, no longer
4397 containing any K&R compatibility code. We believe that all systems in
4398 use today either come with a standard C compiler, or have a GCC port
4399 available. If this is not true, please report the affected
4400 configuration to bug-gdb@gnu.org immediately. See the README file for
4401 information about getting a standard C compiler if you don't have one
4406 GDB now uses readline 2.2.
4408 * set extension-language
4410 You can now control the mapping between filename extensions and source
4411 languages by using the `set extension-language' command. For instance,
4412 you can ask GDB to treat .c files as C++ by saying
4413 set extension-language .c c++
4414 The command `info extensions' lists all of the recognized extensions
4415 and their associated languages.
4417 * Setting processor type for PowerPC and RS/6000
4419 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4420 you can use the `set processor' command to specify what variant of the
4421 PowerPC family you are debugging. The command
4425 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4426 following PowerPC and RS6000 variants:
4428 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4429 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4431 403GC IBM PowerPC 403GC
4432 505 Motorola PowerPC 505
4433 860 Motorola PowerPC 860 or 850
4434 601 Motorola PowerPC 601
4435 602 Motorola PowerPC 602
4436 603 Motorola/IBM PowerPC 603 or 603e
4437 604 Motorola PowerPC 604 or 604e
4438 750 Motorola/IBM PowerPC 750 or 750
4440 At the moment, this command just tells GDB what to name the
4441 special-purpose processor registers. Since almost all the affected
4442 registers are inaccessible to user-level programs, this command is
4443 only useful for remote debugging in its present form.
4447 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4448 more extensive support for HP-UX. Added features include shared
4449 library support, kernel threads and hardware watchpoints for 11.00,
4450 support for HP's ANSI C and C++ compilers, and a compatibility mode
4451 for xdb and dbx commands.
4455 HP's donation includes the new concept of catchpoints, which is a
4456 generalization of the old catch command. On HP-UX, it is now possible
4457 to catch exec, fork, and vfork, as well as library loading.
4459 This means that the existing catch command has changed; its first
4460 argument now specifies the type of catch to be set up. See the
4461 output of "help catch" for a list of catchpoint types.
4463 * Debugging across forks
4465 On HP-UX, you can choose which process to debug when a fork() happens
4470 HP has donated a curses-based terminal user interface (TUI). To get
4471 it, build with --enable-tui. Although this can be enabled for any
4472 configuration, at present it only works for native HP debugging.
4474 * GDB remote protocol additions
4476 A new protocol packet 'X' that writes binary data is now available.
4477 Default behavior is to try 'X', then drop back to 'M' if the stub
4478 fails to respond. The settable variable `remotebinarydownload'
4479 allows explicit control over the use of 'X'.
4481 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4482 full 64-bit address. The command
4484 set remoteaddresssize 32
4486 can be used to revert to the old behaviour. For existing remote stubs
4487 the change should not be noticed, as the additional address information
4490 In order to assist in debugging stubs, you may use the maintenance
4491 command `packet' to send any text string to the stub. For instance,
4493 maint packet heythere
4495 sends the packet "$heythere#<checksum>". Note that it is very easy to
4496 disrupt a debugging session by sending the wrong packet at the wrong
4499 The compare-sections command allows you to compare section data on the
4500 target to what is in the executable file without uploading or
4501 downloading, by comparing CRC checksums.
4503 * Tracing can collect general expressions
4505 You may now collect general expressions at tracepoints. This requires
4506 further additions to the target-side stub; see tracepoint.c and
4507 doc/agentexpr.texi for further details.
4509 * mask-address variable for Mips
4511 For Mips targets, you may control the zeroing of the upper 32 bits of
4512 a 64-bit address by entering `set mask-address on'. This is mainly
4513 of interest to users of embedded R4xxx and R5xxx processors.
4515 * Higher serial baud rates
4517 GDB's serial code now allows you to specify baud rates 57600, 115200,
4518 230400, and 460800 baud. (Note that your host system may not be able
4519 to achieve all of these rates.)
4523 The i960 configuration now includes an initial implementation of a
4524 builtin simulator, contributed by Jim Wilson.
4527 *** Changes in GDB-4.17:
4529 * New native configurations
4531 Alpha GNU/Linux alpha*-*-linux*
4532 Unixware 2.x i[3456]86-unixware2*
4533 Irix 6.x mips*-sgi-irix6*
4534 PowerPC GNU/Linux powerpc-*-linux*
4535 PowerPC Solaris powerpcle-*-solaris*
4536 Sparc GNU/Linux sparc-*-linux*
4537 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4541 Argonaut Risc Chip (ARC) arc-*-*
4542 Hitachi H8/300S h8300*-*-*
4543 Matsushita MN10200 w/simulator mn10200-*-*
4544 Matsushita MN10300 w/simulator mn10300-*-*
4545 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4546 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4547 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4548 Mitsubishi D10V w/simulator d10v-*-*
4549 Mitsubishi M32R/D w/simulator m32r-*-elf*
4550 Tsqware Sparclet sparclet-*-*
4551 NEC V850 w/simulator v850-*-*
4553 * New debugging protocols
4555 ARM with RDI protocol arm*-*-*
4556 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4557 DDB and LSI variants of PMON protocol mips*-*-*
4558 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4559 PowerPC with SDS protocol powerpc{,le}-*-eabi
4560 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4564 All configurations can now understand and use the DWARF 2 debugging
4565 format. The choice is automatic, if the symbol file contains DWARF 2
4570 GDB now includes basic Java language support. This support is
4571 only useful with Java compilers that produce native machine code.
4573 * solib-absolute-prefix and solib-search-path
4575 For SunOS and SVR4 shared libraries, you may now set the prefix for
4576 loading absolute shared library symbol files, and the search path for
4577 locating non-absolute shared library symbol files.
4579 * Live range splitting
4581 GDB can now effectively debug code for which GCC has performed live
4582 range splitting as part of its optimization. See gdb/doc/LRS for
4583 more details on the expected format of the stabs information.
4587 GDB's support for the GNU Hurd, including thread debugging, has been
4588 updated to work with current versions of the Hurd.
4592 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4593 instruction set. ARM GDB automatically detects when Thumb
4594 instructions are in use, and adjusts disassembly and backtracing
4599 GDB's MIPS target configurations now handle the MIP16 16-bit
4604 GDB now includes support for overlays; if an executable has been
4605 linked such that multiple sections are based at the same address, GDB
4606 will decide which section to use for symbolic info. You can choose to
4607 control the decision manually, using overlay commands, or implement
4608 additional target-side support and use "overlay load-target" to bring
4609 in the overlay mapping. Do "help overlay" for more detail.
4613 The command "info symbol <address>" displays information about
4614 the symbol at the specified address.
4618 The standard remote protocol now includes an extension that allows
4619 asynchronous collection and display of trace data. This requires
4620 extensive support in the target-side debugging stub. Tracing mode
4621 includes a new interaction mode in GDB and new commands: see the
4622 file tracepoint.c for more details.
4626 Configurations for embedded MIPS now include a simulator contributed
4627 by Cygnus Solutions. The simulator supports the instruction sets
4628 of most MIPS variants.
4632 Sparc configurations may now include the ERC32 simulator contributed
4633 by the European Space Agency. The simulator is not built into
4634 Sparc targets by default; configure with --enable-sim to include it.
4638 For target configurations that may include multiple variants of a
4639 basic architecture (such as MIPS and SH), you may now set the
4640 architecture explicitly. "set arch" sets, "info arch" lists
4641 the possible architectures.
4643 *** Changes in GDB-4.16:
4645 * New native configurations
4647 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4648 M68K NetBSD m68k-*-netbsd*
4649 PowerPC AIX 4.x powerpc-*-aix*
4650 PowerPC MacOS powerpc-*-macos*
4651 PowerPC Windows NT powerpcle-*-cygwin32
4652 RS/6000 AIX 4.x rs6000-*-aix4*
4656 ARM with RDP protocol arm-*-*
4657 I960 with MON960 i960-*-coff
4658 MIPS VxWorks mips*-*-vxworks*
4659 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4660 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4662 Matra Sparclet sparclet-*-*
4666 The powerpc-eabi configuration now includes the PSIM simulator,
4667 contributed by Andrew Cagney, with assistance from Mike Meissner.
4668 PSIM is a very elaborate model of the PowerPC, including not only
4669 basic instruction set execution, but also details of execution unit
4670 performance and I/O hardware. See sim/ppc/README for more details.
4674 GDB now works with Solaris 2.5.
4676 * Windows 95/NT native
4678 GDB will now work as a native debugger on Windows 95 and Windows NT.
4679 To build it from source, you must use the "gnu-win32" environment,
4680 which uses a DLL to emulate enough of Unix to run the GNU tools.
4681 Further information, binaries, and sources are available at
4682 ftp.cygnus.com, under pub/gnu-win32.
4684 * dont-repeat command
4686 If a user-defined command includes the command `dont-repeat', then the
4687 command will not be repeated if the user just types return. This is
4688 useful if the command is time-consuming to run, so that accidental
4689 extra keystrokes don't run the same command many times.
4691 * Send break instead of ^C
4693 The standard remote protocol now includes an option to send a break
4694 rather than a ^C to the target in order to interrupt it. By default,
4695 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4697 * Remote protocol timeout
4699 The standard remote protocol includes a new variable `remotetimeout'
4700 that allows you to set the number of seconds before GDB gives up trying
4701 to read from the target. The default value is 2.
4703 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4705 By default GDB will automatically keep track of objects as they are
4706 loaded and unloaded by the dynamic linker. By using the command `set
4707 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4708 when shared library events occur, thus allowing you to set breakpoints
4709 in shared libraries which are explicitly loaded by the inferior.
4711 Note this feature does not work on hpux8. On hpux9 you must link
4712 /usr/lib/end.o into your program. This feature should work
4713 automatically on hpux10.
4715 * Irix 5.x hardware watchpoint support
4717 Irix 5 configurations now support the use of hardware watchpoints.
4719 * Mips protocol "SYN garbage limit"
4721 When debugging a Mips target using the `target mips' protocol, you
4722 may set the number of characters that GDB will ignore by setting
4723 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4724 every character. The default value is 1050.
4726 * Recording and replaying remote debug sessions
4728 If you set `remotelogfile' to the name of a file, gdb will write to it
4729 a recording of a remote debug session. This recording may then be
4730 replayed back to gdb using "gdbreplay". See gdbserver/README for
4731 details. This is useful when you have a problem with GDB while doing
4732 remote debugging; you can make a recording of the session and send it
4733 to someone else, who can then recreate the problem.
4735 * Speedups for remote debugging
4737 GDB includes speedups for downloading and stepping MIPS systems using
4738 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4739 and more efficient S-record downloading.
4741 * Memory use reductions and statistics collection
4743 GDB now uses less memory and reports statistics about memory usage.
4744 Try the `maint print statistics' command, for example.
4746 *** Changes in GDB-4.15:
4748 * Psymtabs for XCOFF
4750 The symbol reader for AIX GDB now uses partial symbol tables. This
4751 can greatly improve startup time, especially for large executables.
4753 * Remote targets use caching
4755 Remote targets now use a data cache to speed up communication with the
4756 remote side. The data cache could lead to incorrect results because
4757 it doesn't know about volatile variables, thus making it impossible to
4758 debug targets which use memory mapped I/O devices. `set remotecache
4759 off' turns the the data cache off.
4761 * Remote targets may have threads
4763 The standard remote protocol now includes support for multiple threads
4764 in the target system, using new protocol commands 'H' and 'T'. See
4765 gdb/remote.c for details.
4769 If GDB is configured with `--enable-netrom', then it will include
4770 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4771 acts as though it is a bank of ROM on the target board, but you can
4772 write into it over the network. GDB's support consists only of
4773 support for fast loading into the emulated ROM; to debug, you must use
4774 another protocol, such as standard remote protocol. The usual
4775 sequence is something like
4777 target nrom <netrom-hostname>
4779 target remote <netrom-hostname>:1235
4783 GDB now includes support for the Apple Macintosh, as a host only. It
4784 may be run as either an MPW tool or as a standalone application, and
4785 it can debug through the serial port. All the usual GDB commands are
4786 available, but to the target command, you must supply "serial" as the
4787 device type instead of "/dev/ttyXX". See mpw-README in the main
4788 directory for more information on how to build. The MPW configuration
4789 scripts */mpw-config.in support only a few targets, and only the
4790 mips-idt-ecoff target has been tested.
4794 GDB configuration now uses autoconf. This is not user-visible,
4795 but does simplify configuration and building.
4799 GDB now supports hpux10.
4801 *** Changes in GDB-4.14:
4803 * New native configurations
4805 x86 FreeBSD i[345]86-*-freebsd
4806 x86 NetBSD i[345]86-*-netbsd
4807 NS32k NetBSD ns32k-*-netbsd
4808 Sparc NetBSD sparc-*-netbsd
4812 A29K VxWorks a29k-*-vxworks
4813 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4814 CPU32 EST-300 emulator m68*-*-est*
4815 PowerPC ELF powerpc-*-elf
4818 * Alpha OSF/1 support for procfs
4820 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4821 possible to attach to running processes. As the mounting of the /proc
4822 filesystem is optional on the Alpha, GDB automatically determines
4823 the availability of /proc during startup. This can lead to problems
4824 if /proc is unmounted after GDB has been started.
4826 * Arguments to user-defined commands
4828 User commands may accept up to 10 arguments separated by whitespace.
4829 Arguments are accessed within the user command via $arg0..$arg9. A
4832 print $arg0 + $arg1 + $arg2
4834 To execute the command use:
4837 Defines the command "adder" which prints the sum of its three arguments.
4838 Note the arguments are text substitutions, so they may reference variables,
4839 use complex expressions, or even perform inferior function calls.
4841 * New `if' and `while' commands
4843 This makes it possible to write more sophisticated user-defined
4844 commands. Both commands take a single argument, which is the
4845 expression to evaluate, and must be followed by the commands to
4846 execute, one per line, if the expression is nonzero, the list being
4847 terminated by the word `end'. The `if' command list may include an
4848 `else' word, which causes the following commands to be executed only
4849 if the expression is zero.
4851 * Fortran source language mode
4853 GDB now includes partial support for Fortran 77. It will recognize
4854 Fortran programs and can evaluate a subset of Fortran expressions, but
4855 variables and functions may not be handled correctly. GDB will work
4856 with G77, but does not yet know much about symbols emitted by other
4859 * Better HPUX support
4861 Most debugging facilities now work on dynamic executables for HPPAs
4862 running hpux9 or later. You can attach to running dynamically linked
4863 processes, but by default the dynamic libraries will be read-only, so
4864 for instance you won't be able to put breakpoints in them. To change
4865 that behavior do the following before running the program:
4871 This will cause the libraries to be mapped private and read-write.
4872 To revert to the normal behavior, do this:
4878 You cannot set breakpoints or examine data in the library until after
4879 the library is loaded if the function/data symbols do not have
4882 GDB can now also read debug symbols produced by the HP C compiler on
4883 HPPAs (sorry, no C++, Fortran or 68k support).
4885 * Target byte order now dynamically selectable
4887 You can choose which byte order to use with a target system, via the
4888 commands "set endian big" and "set endian little", and you can see the
4889 current setting by using "show endian". You can also give the command
4890 "set endian auto", in which case GDB will use the byte order
4891 associated with the executable. Currently, only embedded MIPS
4892 configurations support dynamic selection of target byte order.
4894 * New DOS host serial code
4896 This version uses DPMI interrupts to handle buffered I/O, so you
4897 no longer need to run asynctsr when debugging boards connected to
4900 *** Changes in GDB-4.13:
4902 * New "complete" command
4904 This lists all the possible completions for the rest of the line, if it
4905 were to be given as a command itself. This is intended for use by emacs.
4907 * Trailing space optional in prompt
4909 "set prompt" no longer adds a space for you after the prompt you set. This
4910 allows you to set a prompt which ends in a space or one that does not.
4912 * Breakpoint hit counts
4914 "info break" now displays a count of the number of times the breakpoint
4915 has been hit. This is especially useful in conjunction with "ignore"; you
4916 can ignore a large number of breakpoint hits, look at the breakpoint info
4917 to see how many times the breakpoint was hit, then run again, ignoring one
4918 less than that number, and this will get you quickly to the last hit of
4921 * Ability to stop printing at NULL character
4923 "set print null-stop" will cause GDB to stop printing the characters of
4924 an array when the first NULL is encountered. This is useful when large
4925 arrays actually contain only short strings.
4927 * Shared library breakpoints
4929 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4930 breakpoints in shared libraries before the executable is run.
4932 * Hardware watchpoints
4934 There is a new hardware breakpoint for the watch command for sparclite
4935 targets. See gdb/sparclite/hw_breakpoint.note.
4937 Hardware watchpoints are also now supported under GNU/Linux.
4941 Annotations have been added. These are for use with graphical interfaces,
4942 and are still experimental. Currently only gdba.el uses these.
4944 * Improved Irix 5 support
4946 GDB now works properly with Irix 5.2.
4948 * Improved HPPA support
4950 GDB now works properly with the latest GCC and GAS.
4952 * New native configurations
4954 Sequent PTX4 i[34]86-sequent-ptx4
4955 HPPA running OSF/1 hppa*-*-osf*
4956 Atari TT running SVR4 m68*-*-sysv4*
4957 RS/6000 LynxOS rs6000-*-lynxos*
4961 OS/9000 i[34]86-*-os9k
4962 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4965 * Hitachi SH7000 and E7000-PC ICE support
4967 There is now support for communicating with the Hitachi E7000-PC ICE.
4968 This is available automatically when GDB is configured for the SH.
4972 As usual, a variety of small fixes and improvements, both generic
4973 and configuration-specific. See the ChangeLog for more detail.
4975 *** Changes in GDB-4.12:
4977 * Irix 5 is now supported
4981 GDB-4.12 on the HPPA has a number of changes which make it unable
4982 to debug the output from the currently released versions of GCC and
4983 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4984 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4985 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4988 *** Changes in GDB-4.11:
4990 * User visible changes:
4994 The "set remotedebug" option is now consistent between the mips remote
4995 target, remote targets using the gdb-specific protocol, UDI (AMD's
4996 debug protocol for the 29k) and the 88k bug monitor. It is now an
4997 integer specifying a debug level (normally 0 or 1, but 2 means more
4998 debugging info for the mips target).
5000 * DEC Alpha native support
5002 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5003 debug info, but GDB works fairly well with the DEC compiler and should
5004 work with a future GCC release. See the README file for a few
5005 Alpha-specific notes.
5007 * Preliminary thread implementation
5009 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5011 * LynxOS native and target support for 386
5013 This release has been hosted on LynxOS 2.2, and also can be configured
5014 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5017 * Improvements in C++ mangling/demangling.
5019 This release has much better g++ debugging, specifically in name
5020 mangling/demangling, virtual function calls, print virtual table,
5021 call methods, ...etc.
5023 *** Changes in GDB-4.10:
5025 * User visible changes:
5027 Remote debugging using the GDB-specific (`target remote') protocol now
5028 supports the `load' command. This is only useful if you have some
5029 other way of getting the stub to the target system, and you can put it
5030 somewhere in memory where it won't get clobbered by the download.
5032 Filename completion now works.
5034 When run under emacs mode, the "info line" command now causes the
5035 arrow to point to the line specified. Also, "info line" prints
5036 addresses in symbolic form (as well as hex).
5038 All vxworks based targets now support a user settable option, called
5039 vxworks-timeout. This option represents the number of seconds gdb
5040 should wait for responses to rpc's. You might want to use this if
5041 your vxworks target is, perhaps, a slow software simulator or happens
5042 to be on the far side of a thin network line.
5046 This release contains support for using a DEC alpha as a GDB host for
5047 cross debugging. Native alpha debugging is not supported yet.
5050 *** Changes in GDB-4.9:
5054 This is the first GDB release which is accompanied by a matching testsuite.
5055 The testsuite requires installation of dejagnu, which should be available
5056 via ftp from most sites that carry GNU software.
5060 'Cfront' style demangling has had its name changed to 'ARM' style, to
5061 emphasize that it was written from the specifications in the C++ Annotated
5062 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5063 disclaimers, it still generated too much confusion with users attempting to
5064 use gdb with AT&T cfront.
5068 GDB now uses a standard remote interface to a simulator library.
5069 So far, the library contains simulators for the Zilog Z8001/2, the
5070 Hitachi H8/300, H8/500 and Super-H.
5072 * New targets supported
5074 H8/300 simulator h8300-hitachi-hms or h8300hms
5075 H8/500 simulator h8500-hitachi-hms or h8500hms
5076 SH simulator sh-hitachi-hms or sh
5077 Z8000 simulator z8k-zilog-none or z8ksim
5078 IDT MIPS board over serial line mips-idt-ecoff
5080 Cross-debugging to GO32 targets is supported. It requires a custom
5081 version of the i386-stub.c module which is integrated with the
5082 GO32 memory extender.
5084 * New remote protocols
5086 MIPS remote debugging protocol.
5088 * New source languages supported
5090 This version includes preliminary support for Chill, a Pascal like language
5091 used by telecommunications companies. Chill support is also being integrated
5092 into the GNU compiler, but we don't know when it will be publically available.
5095 *** Changes in GDB-4.8:
5097 * HP Precision Architecture supported
5099 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5100 version of this support was available as a set of patches from the
5101 University of Utah. GDB does not support debugging of programs
5102 compiled with the HP compiler, because HP will not document their file
5103 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5104 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5106 Many problems in the preliminary version have been fixed.
5108 * Faster and better demangling
5110 We have improved template demangling and fixed numerous bugs in the GNU style
5111 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5112 character types (wchar_t) are now supported. Demangling of each symbol is now
5113 only done once, and is cached when the symbol table for a file is read in.
5114 This results in a small increase in memory usage for C programs, a moderate
5115 increase in memory usage for C++ programs, and a fantastic speedup in
5118 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5119 from the specifications in the Annotated Reference Manual, which AT&T's
5120 compiler does not actually implement.
5122 * G++ multiple inheritance compiler problem
5124 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5125 inheritance lattices was reworked to properly discover ambiguities. We
5126 recently found an example which causes this new algorithm to fail in a
5127 very subtle way, producing bad debug information for those classes.
5128 The file 'gcc.patch' (in this directory) can be applied to gcc to
5129 circumvent the problem. A future GCC release will contain a complete
5132 The previous G++ debug info problem (mentioned below for the gdb-4.7
5133 release) is fixed in gcc version 2.3.2.
5135 * Improved configure script
5137 The `configure' script will now attempt to guess your system type if
5138 you don't supply a host system type. The old scheme of supplying a
5139 host system triplet is preferable over using this. All the magic is
5140 done in the new `config.guess' script. Examine it for details.
5142 We have also brought our configure script much more in line with the FSF's
5143 version. It now supports the --with-xxx options. In particular,
5144 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5145 The resulting GDB will not be able to read arbitrary object file formats --
5146 only the format ``expected'' to be used on the configured target system.
5147 We hope to make this the default in a future release.
5149 * Documentation improvements
5151 There's new internal documentation on how to modify GDB, and how to
5152 produce clean changes to the code. We implore people to read it
5153 before submitting changes.
5155 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5156 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5157 `info' files are also provided. To build `info' files from scratch,
5158 you will need the latest `makeinfo' release, which will be available in
5159 a future texinfo-X.Y release.
5161 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5162 We're not sure exactly which versions have this problem, but it has
5163 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5164 or better. If that isn't possible, there is a patch in
5165 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5166 around this problem.
5170 GDB now supports array constants that can be used in expressions typed in by
5171 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5172 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5175 The new directory `gdb/sparclite' contains a program that demonstrates
5176 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5178 * New native hosts supported
5180 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5181 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5183 * New targets supported
5185 AMD 29k family via UDI a29k-amd-udi or udi29k
5187 * New file formats supported
5189 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5190 HPUX core files, and SCO 3.2v2 core files.
5194 Attaching to processes now works again; thanks for the many bug reports.
5196 We have also stomped on a bunch of core dumps caused by
5197 printf_filtered("%s") problems.
5199 We eliminated a copyright problem on the rpc and ptrace header files
5200 for VxWorks, which was discovered at the last minute during the 4.7
5201 release. You should now be able to build a VxWorks GDB.
5203 You can now interrupt gdb while an attached process is running. This
5204 will cause the attached process to stop, and give control back to GDB.
5206 We fixed problems caused by using too many file descriptors
5207 for reading symbols from object files and libraries. This was
5208 especially a problem for programs that used many (~100) shared
5211 The `step' command now only enters a subroutine if there is line number
5212 information for the subroutine. Otherwise it acts like the `next'
5213 command. Previously, `step' would enter subroutines if there was
5214 any debugging information about the routine. This avoids problems
5215 when using `cc -g1' on MIPS machines.
5217 * Internal improvements
5219 GDB's internal interfaces have been improved to make it easier to support
5220 debugging of multiple languages in the future.
5222 GDB now uses a common structure for symbol information internally.
5223 Minimal symbols (derived from linkage symbols in object files), partial
5224 symbols (from a quick scan of debug information), and full symbols
5225 contain a common subset of information, making it easier to write
5226 shared code that handles any of them.
5228 * New command line options
5230 We now accept --silent as an alias for --quiet.
5234 The memory-mapped-malloc library is now licensed under the GNU Library
5235 General Public License.
5237 *** Changes in GDB-4.7:
5239 * Host/native/target split
5241 GDB has had some major internal surgery to untangle the support for
5242 hosts and remote targets. Now, when you configure GDB for a remote
5243 target, it will no longer load in all of the support for debugging
5244 local programs on the host. When fully completed and tested, this will
5245 ensure that arbitrary host/target combinations are possible.
5247 The primary conceptual shift is to separate the non-portable code in
5248 GDB into three categories. Host specific code is required any time GDB
5249 is compiled on that host, regardless of the target. Target specific
5250 code relates to the peculiarities of the target, but can be compiled on
5251 any host. Native specific code is everything else: it can only be
5252 built when the host and target are the same system. Child process
5253 handling and core file support are two common `native' examples.
5255 GDB's use of /proc for controlling Unix child processes is now cleaner.
5256 It has been split out into a single module under the `target_ops' vector,
5257 plus two native-dependent functions for each system that uses /proc.
5259 * New hosts supported
5261 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5262 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5263 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5265 * New targets supported
5267 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5268 68030 and CPU32 m68030-*-*, m68332-*-*
5270 * New native hosts supported
5272 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5273 (386bsd is not well tested yet)
5274 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5276 * New file formats supported
5278 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5279 supports reading of `a.out.adobe' object files, which are an a.out
5280 format extended with minimal information about multiple sections.
5284 `show copying' is the same as the old `info copying'.
5285 `show warranty' is the same as `info warrantee'.
5286 These were renamed for consistency. The old commands continue to work.
5288 `info handle' is a new alias for `info signals'.
5290 You can now define pre-command hooks, which attach arbitrary command
5291 scripts to any command. The commands in the hook will be executed
5292 prior to the user's command. You can also create a hook which will be
5293 executed whenever the program stops. See gdb.texinfo.
5297 We now deal with Cfront style name mangling, and can even extract type
5298 info from mangled symbols. GDB can automatically figure out which
5299 symbol mangling style your C++ compiler uses.
5301 Calling of methods and virtual functions has been improved as well.
5305 The crash that occured when debugging Sun Ansi-C compiled binaries is
5306 fixed. This was due to mishandling of the extra N_SO stabs output
5309 We also finally got Ultrix 4.2 running in house, and fixed core file
5310 support, with help from a dozen people on the net.
5312 John M. Farrell discovered that the reason that single-stepping was so
5313 slow on all of the Mips based platforms (primarily SGI and DEC) was
5314 that we were trying to demangle and lookup a symbol used for internal
5315 purposes on every instruction that was being stepped through. Changing
5316 the name of that symbol so that it couldn't be mistaken for a C++
5317 mangled symbol sped things up a great deal.
5319 Rich Pixley sped up symbol lookups in general by getting much smarter
5320 about when C++ symbol mangling is necessary. This should make symbol
5321 completion (TAB on the command line) much faster. It's not as fast as
5322 we'd like, but it's significantly faster than gdb-4.6.
5326 A new user controllable variable 'call_scratch_address' can
5327 specify the location of a scratch area to be used when GDB
5328 calls a function in the target. This is necessary because the
5329 usual method of putting the scratch area on the stack does not work
5330 in systems that have separate instruction and data spaces.
5332 We integrated changes to support the 29k UDI (Universal Debugger
5333 Interface), but discovered at the last minute that we didn't have all
5334 of the appropriate copyright paperwork. We are working with AMD to
5335 resolve this, and hope to have it available soon.
5339 We have sped up the remote serial line protocol, especially for targets
5340 with lots of registers. It now supports a new `expedited status' ('T')
5341 message which can be used in place of the existing 'S' status message.
5342 This allows the remote stub to send only the registers that GDB
5343 needs to make a quick decision about single-stepping or conditional
5344 breakpoints, eliminating the need to fetch the entire register set for
5345 each instruction being stepped through.
5347 The GDB remote serial protocol now implements a write-through cache for
5348 registers, only re-reading the registers if the target has run.
5350 There is also a new remote serial stub for SPARC processors. You can
5351 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5352 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5353 processor with a serial port.
5357 Configure.in files have become much easier to read and modify. A new
5358 `table driven' format makes it more obvious what configurations are
5359 supported, and what files each one uses.
5363 There is a new opcodes library which will eventually contain all of the
5364 disassembly routines and opcode tables. At present, it only contains
5365 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5366 disassembler (binutils/objdump) to share these routines.
5368 The libiberty library is now copylefted under the GNU Library General
5369 Public License. This allows more liberal use, and was done so libg++
5370 can use it. This makes no difference to GDB, since the Library License
5371 grants all the rights from the General Public License.
5375 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5376 reference to the stabs symbol info used by the debugger. It is (as far
5377 as we know) the only published document on this fascinating topic. We
5378 encourage you to read it, compare it to the stabs information on your
5379 system, and send improvements on the document in general (to
5380 bug-gdb@prep.ai.mit.edu).
5382 And, of course, many bugs have been fixed.
5385 *** Changes in GDB-4.6:
5387 * Better support for C++ function names
5389 GDB now accepts as input the "demangled form" of C++ overloaded function
5390 names and member function names, and can do command completion on such names
5391 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5392 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5393 Make use of command completion, it is your friend.
5395 GDB also now accepts a variety of C++ mangled symbol formats. They are
5396 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5397 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5398 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5399 for the list of formats.
5401 * G++ symbol mangling problem
5403 Recent versions of gcc have a bug in how they emit debugging information for
5404 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5405 directory) can be applied to gcc to fix the problem. Alternatively, if you
5406 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5407 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5408 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5411 * New 'maintenance' command
5413 All of the commands related to hacking GDB internals have been moved out of
5414 the main command set, and now live behind the 'maintenance' command. This
5415 can also be abbreviated as 'mt'. The following changes were made:
5417 dump-me -> maintenance dump-me
5418 info all-breakpoints -> maintenance info breakpoints
5419 printmsyms -> maintenance print msyms
5420 printobjfiles -> maintenance print objfiles
5421 printpsyms -> maintenance print psymbols
5422 printsyms -> maintenance print symbols
5424 The following commands are new:
5426 maintenance demangle Call internal GDB demangler routine to
5427 demangle a C++ link name and prints the result.
5428 maintenance print type Print a type chain for a given symbol
5430 * Change to .gdbinit file processing
5432 We now read the $HOME/.gdbinit file before processing the argv arguments
5433 (e.g. reading symbol files or core files). This allows global parameters to
5434 be set, which will apply during the symbol reading. The ./.gdbinit is still
5435 read after argv processing.
5437 * New hosts supported
5439 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5441 GNU/Linux support i386-unknown-linux or linux
5443 We are also including code to support the HP/PA running BSD and HPUX. This
5444 is almost guaranteed not to work, as we didn't have time to test or build it
5445 for this release. We are including it so that the more adventurous (or
5446 masochistic) of you can play with it. We also had major problems with the
5447 fact that the compiler that we got from HP doesn't support the -g option.
5450 * New targets supported
5452 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5454 * More smarts about finding #include files
5456 GDB now remembers the compilation directory for all include files, and for
5457 all files from which C is generated (like yacc and lex sources). This
5458 greatly improves GDB's ability to find yacc/lex sources, and include files,
5459 especially if you are debugging your program from a directory different from
5460 the one that contains your sources.
5462 We also fixed a bug which caused difficulty with listing and setting
5463 breakpoints in include files which contain C code. (In the past, you had to
5464 try twice in order to list an include file that you hadn't looked at before.)
5466 * Interesting infernals change
5468 GDB now deals with arbitrary numbers of sections, where the symbols for each
5469 section must be relocated relative to that section's landing place in the
5470 target's address space. This work was needed to support ELF with embedded
5471 stabs used by Solaris-2.0.
5473 * Bug fixes (of course!)
5475 There have been loads of fixes for the following things:
5476 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5477 i960, stabs, DOS(GO32), procfs, etc...
5479 See the ChangeLog for details.
5481 *** Changes in GDB-4.5:
5483 * New machines supported (host and target)
5485 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5487 SGI Irix-4.x mips-sgi-irix4 or iris4
5489 * New malloc package
5491 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5492 Mmalloc is capable of handling mutiple heaps of memory. It is also
5493 capable of saving a heap to a file, and then mapping it back in later.
5494 This can be used to greatly speedup the startup of GDB by using a
5495 pre-parsed symbol table which lives in a mmalloc managed heap. For
5496 more details, please read mmalloc/mmalloc.texi.
5500 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5501 'help info proc' for details.
5503 * MIPS ecoff symbol table format
5505 The code that reads MIPS symbol table format is now supported on all hosts.
5506 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5509 * File name changes for MS-DOS
5511 Many files in the config directories have been renamed to make it easier to
5512 support GDB on MS-DOSe systems (which have very restrictive file name
5513 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5514 environment) is close to working but has some remaining problems. Note
5515 that debugging of DOS programs is not supported, due to limitations
5516 in the ``operating system'', but it can be used to host cross-debugging.
5518 * Cross byte order fixes
5520 Many fixes have been made to support cross debugging of Sparc and MIPS
5521 targets from hosts whose byte order differs.
5523 * New -mapped and -readnow options
5525 If memory-mapped files are available on your system through the 'mmap'
5526 system call, you can use the -mapped option on the `file' or
5527 `symbol-file' commands to cause GDB to write the symbols from your
5528 program into a reusable file. If the program you are debugging is
5529 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5530 Future GDB debugging sessions will notice the presence of this file,
5531 and will quickly map in symbol information from it, rather than reading
5532 the symbol table from the executable program. Using the '-mapped'
5533 option in a GDB `file' or `symbol-file' command has the same effect as
5534 starting GDB with the '-mapped' command-line option.
5536 You can cause GDB to read the entire symbol table immediately by using
5537 the '-readnow' option with any of the commands that load symbol table
5538 information (or on the GDB command line). This makes the command
5539 slower, but makes future operations faster.
5541 The -mapped and -readnow options are typically combined in order to
5542 build a `fred.syms' file that contains complete symbol information.
5543 A simple GDB invocation to do nothing but build a `.syms' file for future
5546 gdb -batch -nx -mapped -readnow programname
5548 The `.syms' file is specific to the host machine on which GDB is run.
5549 It holds an exact image of GDB's internal symbol table. It cannot be
5550 shared across multiple host platforms.
5552 * longjmp() handling
5554 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5555 siglongjmp() without losing control. This feature has not yet been ported to
5556 all systems. It currently works on many 386 platforms, all MIPS-based
5557 platforms (SGI, DECstation, etc), and Sun3/4.
5561 Preliminary work has been put in to support the new Solaris OS from Sun. At
5562 this time, it can control and debug processes, but it is not capable of
5567 As always, many many bug fixes. The major areas were with g++, and mipsread.
5568 People using the MIPS-based platforms should experience fewer mysterious
5569 crashes and trashed symbol tables.
5571 *** Changes in GDB-4.4:
5573 * New machines supported (host and target)
5575 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5577 BSD Reno on Vax vax-dec-bsd
5578 Ultrix on Vax vax-dec-ultrix
5580 * New machines supported (target)
5582 AMD 29000 embedded, using EBMON a29k-none-none
5586 GDB continues to improve its handling of C++. `References' work better.
5587 The demangler has also been improved, and now deals with symbols mangled as
5588 per the Annotated C++ Reference Guide.
5590 GDB also now handles `stabs' symbol information embedded in MIPS
5591 `ecoff' symbol tables. Since the ecoff format was not easily
5592 extensible to handle new languages such as C++, this appeared to be a
5593 good way to put C++ debugging info into MIPS binaries. This option
5594 will be supported in the GNU C compiler, version 2, when it is
5597 * New features for SVR4
5599 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5600 shared libraries. Debugging dynamically linked programs should present
5601 only minor differences from debugging statically linked programs.
5603 The `info proc' command will print out information about any process
5604 on an SVR4 system (including the one you are debugging). At the moment,
5605 it prints the address mappings of the process.
5607 If you bring up GDB on another SVR4 system, please send mail to
5608 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5610 * Better dynamic linking support in SunOS
5612 Reading symbols from shared libraries which contain debugging symbols
5613 now works properly. However, there remain issues such as automatic
5614 skipping of `transfer vector' code during function calls, which
5615 make it harder to debug code in a shared library, than to debug the
5616 same code linked statically.
5620 GDB is now using the latest `getopt' routines from the FSF. This
5621 version accepts the -- prefix for options with long names. GDB will
5622 continue to accept the old forms (-option and +option) as well.
5623 Various single letter abbreviations for options have been explicity
5624 added to the option table so that they won't get overshadowed in the
5625 future by other options that begin with the same letter.
5629 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5630 Many assorted bugs have been handled. Many more remain to be handled.
5631 See the various ChangeLog files (primarily in gdb and bfd) for details.
5634 *** Changes in GDB-4.3:
5636 * New machines supported (host and target)
5638 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5639 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5640 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5642 * Almost SCO Unix support
5644 We had hoped to support:
5645 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5646 (except for core file support), but we discovered very late in the release
5647 that it has problems with process groups that render gdb unusable. Sorry
5648 about that. I encourage people to fix it and post the fixes.
5650 * Preliminary ELF and DWARF support
5652 GDB can read ELF object files on System V Release 4, and can handle
5653 debugging records for C, in DWARF format, in ELF files. This support
5654 is preliminary. If you bring up GDB on another SVR4 system, please
5655 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5660 GDB now uses the latest `readline' library. One user-visible change
5661 is that two tabs will list possible command completions, which previously
5662 required typing M-? (meta-question mark, or ESC ?).
5666 The `stepi' bug that many of you noticed has been squashed.
5667 Many bugs in C++ have been handled. Many more remain to be handled.
5668 See the various ChangeLog files (primarily in gdb and bfd) for details.
5670 * State of the MIPS world (in case you wondered):
5672 GDB can understand the symbol tables emitted by the compilers
5673 supplied by most vendors of MIPS-based machines, including DEC. These
5674 symbol tables are in a format that essentially nobody else uses.
5676 Some versions of gcc come with an assembler post-processor called
5677 mips-tfile. This program is required if you want to do source-level
5678 debugging of gcc-compiled programs. I believe FSF does not ship
5679 mips-tfile with gcc version 1, but it will eventually come with gcc
5682 Debugging of g++ output remains a problem. g++ version 1.xx does not
5683 really support it at all. (If you're lucky, you should be able to get
5684 line numbers and stack traces to work, but no parameters or local
5685 variables.) With some work it should be possible to improve the
5688 When gcc version 2 is released, you will have somewhat better luck.
5689 However, even then you will get confusing results for inheritance and
5692 We will eventually provide full debugging of g++ output on
5693 DECstations. This will probably involve some kind of stabs-in-ecoff
5694 encapulation, but the details have not been worked out yet.
5697 *** Changes in GDB-4.2:
5699 * Improved configuration
5701 Only one copy of `configure' exists now, and it is not self-modifying.
5702 Porting BFD is simpler.
5706 The `step' and `next' commands now only stop at the first instruction
5707 of a source line. This prevents the multiple stops that used to occur
5708 in switch statements, for-loops, etc. `Step' continues to stop if a
5709 function that has debugging information is called within the line.
5713 Lots of small bugs fixed. More remain.
5715 * New host supported (not target)
5717 Intel 386 PC clone running Mach i386-none-mach
5720 *** Changes in GDB-4.1:
5722 * Multiple source language support
5724 GDB now has internal scaffolding to handle several source languages.
5725 It determines the type of each source file from its filename extension,
5726 and will switch expression parsing and number formatting to match the
5727 language of the function in the currently selected stack frame.
5728 You can also specifically set the language to be used, with
5729 `set language c' or `set language modula-2'.
5733 GDB now has preliminary support for the GNU Modula-2 compiler,
5734 currently under development at the State University of New York at
5735 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5736 continue through the fall of 1991 and into 1992.
5738 Other Modula-2 compilers are currently not supported, and attempting to
5739 debug programs compiled with them will likely result in an error as the
5740 symbol table is read. Feel free to work on it, though!
5742 There are hooks in GDB for strict type checking and range checking,
5743 in the `Modula-2 philosophy', but they do not currently work.
5747 GDB can now write to executable and core files (e.g. patch
5748 a variable's value). You must turn this switch on, specify
5749 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5750 by assigning a new value to a variable. Modifications take
5753 * Automatic SunOS shared library reading
5755 When you run your program, GDB automatically determines where its
5756 shared libraries (if any) have been loaded, and reads their symbols.
5757 The `share' command is no longer needed. This also works when
5758 examining core files.
5762 You can specify the number of lines that the `list' command shows.
5765 * New machines supported (host and target)
5767 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5768 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5769 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5771 * New hosts supported (not targets)
5773 IBM RT/PC: romp-ibm-aix or rtpc
5775 * New targets supported (not hosts)
5777 AMD 29000 embedded with COFF a29k-none-coff
5778 AMD 29000 embedded with a.out a29k-none-aout
5779 Ultracomputer remote kernel debug a29k-nyu-kern
5781 * New remote interfaces
5787 *** Changes in GDB-4.0:
5791 Wide output is wrapped at good places to make the output more readable.
5793 Gdb now supports cross-debugging from a host machine of one type to a
5794 target machine of another type. Communication with the target system
5795 is over serial lines. The ``target'' command handles connecting to the
5796 remote system; the ``load'' command will download a program into the
5797 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5798 also supports debugging of realtime processes running under VxWorks,
5799 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5800 stub on the target system.
5802 New CPUs supported include the AMD 29000 and Intel 960.
5804 GDB now reads object files and symbol tables via a ``binary file''
5805 library, which allows a single copy of GDB to debug programs of multiple
5806 object file types such as a.out and coff.
5808 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5809 refcard.dvi and refcard.ps are available to format it).
5812 * Control-Variable user interface simplified
5814 All variables that control the operation of the debugger can be set
5815 by the ``set'' command, and displayed by the ``show'' command.
5817 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5818 ``Show prompt'' produces the response:
5819 Gdb's prompt is new-gdb=>.
5821 What follows are the NEW set commands. The command ``help set'' will
5822 print a complete list of old and new set commands. ``help set FOO''
5823 will give a longer description of the variable FOO. ``show'' will show
5824 all of the variable descriptions and their current settings.
5826 confirm on/off: Enables warning questions for operations that are
5827 hard to recover from, e.g. rerunning the program while
5828 it is already running. Default is ON.
5830 editing on/off: Enables EMACS style command line editing
5831 of input. Previous lines can be recalled with
5832 control-P, the current line can be edited with control-B,
5833 you can search for commands with control-R, etc.
5836 history filename NAME: NAME is where the gdb command history
5837 will be stored. The default is .gdb_history,
5838 or the value of the environment variable
5841 history size N: The size, in commands, of the command history. The
5842 default is 256, or the value of the environment variable
5845 history save on/off: If this value is set to ON, the history file will
5846 be saved after exiting gdb. If set to OFF, the
5847 file will not be saved. The default is OFF.
5849 history expansion on/off: If this value is set to ON, then csh-like
5850 history expansion will be performed on
5851 command line input. The default is OFF.
5853 radix N: Sets the default radix for input and output. It can be set
5854 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5855 in the current radix, so "set radix 10" is always a no-op.
5857 height N: This integer value is the number of lines on a page. Default
5858 is 24, the current `stty rows'' setting, or the ``li#''
5859 setting from the termcap entry matching the environment
5862 width N: This integer value is the number of characters on a line.
5863 Default is 80, the current `stty cols'' setting, or the ``co#''
5864 setting from the termcap entry matching the environment
5867 Note: ``set screensize'' is obsolete. Use ``set height'' and
5868 ``set width'' instead.
5870 print address on/off: Print memory addresses in various command displays,
5871 such as stack traces and structure values. Gdb looks
5872 more ``symbolic'' if you turn this off; it looks more
5873 ``machine level'' with it on. Default is ON.
5875 print array on/off: Prettyprint arrays. New convenient format! Default
5878 print demangle on/off: Print C++ symbols in "source" form if on,
5881 print asm-demangle on/off: Same, for assembler level printouts
5884 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5887 * Support for Epoch Environment.
5889 The epoch environment is a version of Emacs v18 with windowing. One
5890 new command, ``inspect'', is identical to ``print'', except that if you
5891 are running in the epoch environment, the value is printed in its own
5895 * Support for Shared Libraries
5897 GDB can now debug programs and core files that use SunOS shared libraries.
5898 Symbols from a shared library cannot be referenced
5899 before the shared library has been linked with the program (this
5900 happens after you type ``run'' and before the function main() is entered).
5901 At any time after this linking (including when examining core files
5902 from dynamically linked programs), gdb reads the symbols from each
5903 shared library when you type the ``sharedlibrary'' command.
5904 It can be abbreviated ``share''.
5906 sharedlibrary REGEXP: Load shared object library symbols for files
5907 matching a unix regular expression. No argument
5908 indicates to load symbols for all shared libraries.
5910 info sharedlibrary: Status of loaded shared libraries.
5915 A watchpoint stops execution of a program whenever the value of an
5916 expression changes. Checking for this slows down execution
5917 tremendously whenever you are in the scope of the expression, but is
5918 quite useful for catching tough ``bit-spreader'' or pointer misuse
5919 problems. Some machines such as the 386 have hardware for doing this
5920 more quickly, and future versions of gdb will use this hardware.
5922 watch EXP: Set a watchpoint (breakpoint) for an expression.
5924 info watchpoints: Information about your watchpoints.
5926 delete N: Deletes watchpoint number N (same as breakpoints).
5927 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5928 enable N: Re-enables watchpoint number N (same as breakpoints).
5931 * C++ multiple inheritance
5933 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5936 * C++ exception handling
5938 Gdb now supports limited C++ exception handling. Besides the existing
5939 ability to breakpoint on an exception handler, gdb can breakpoint on
5940 the raising of an exception (before the stack is peeled back to the
5943 catch FOO: If there is a FOO exception handler in the dynamic scope,
5944 set a breakpoint to catch exceptions which may be raised there.
5945 Multiple exceptions (``catch foo bar baz'') may be caught.
5947 info catch: Lists all exceptions which may be caught in the
5948 current stack frame.
5951 * Minor command changes
5953 The command ``call func (arg, arg, ...)'' now acts like the print
5954 command, except it does not print or save a value if the function's result
5955 is void. This is similar to dbx usage.
5957 The ``up'' and ``down'' commands now always print the frame they end up
5958 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5959 frames without printing.
5961 * New directory command
5963 'dir' now adds directories to the FRONT of the source search path.
5964 The path starts off empty. Source files that contain debug information
5965 about the directory in which they were compiled can be found even
5966 with an empty path; Sun CC and GCC include this information. If GDB can't
5967 find your source file in the current directory, type "dir .".
5969 * Configuring GDB for compilation
5971 For normal use, type ``./configure host''. See README or gdb.texinfo
5974 GDB now handles cross debugging. If you are remotely debugging between
5975 two different machines, type ``./configure host -target=targ''.
5976 Host is the machine where GDB will run; targ is the machine
5977 where the program that you are debugging will run.