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.
77 Return information about files on the remote system.
79 * The info record command now shows the recording format and the
80 branch tracing configuration for the current thread when using
81 the btrace record target.
82 For the BTS format, it shows the ring buffer size.
84 * GDB now has support for DTrace USDT (Userland Static Defined
85 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
87 * GDB now supports access to vector registers on S/390 GNU/Linux
90 *** Changes in GDB 7.9
92 * GDB now supports hardware watchpoints on x86 GNU Hurd.
96 ** You can now access frame registers from Python scripts.
97 ** New attribute 'producer' for gdb.Symtab objects.
98 ** gdb.Objfile objects have a new attribute "progspace",
99 which is the gdb.Progspace object of the containing program space.
100 ** gdb.Objfile objects have a new attribute "owner".
101 ** gdb.Objfile objects have a new attribute "build_id",
102 which is the build ID generated when the file was built.
103 ** gdb.Objfile objects have a new method "add_separate_debug_file".
104 ** A new event "gdb.clear_objfiles" has been added, triggered when
105 selecting a new file to debug.
106 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
107 ** New function gdb.lookup_objfile.
109 New events which are triggered when GDB modifies the state of the
112 ** gdb.events.inferior_call_pre: Function call is about to be made.
113 ** gdb.events.inferior_call_post: Function call has just been made.
114 ** gdb.events.memory_changed: A memory location has been altered.
115 ** gdb.events.register_changed: A register has been altered.
117 * New Python-based convenience functions:
119 ** $_caller_is(name [, number_of_frames])
120 ** $_caller_matches(regexp [, number_of_frames])
121 ** $_any_caller_is(name [, number_of_frames])
122 ** $_any_caller_matches(regexp [, number_of_frames])
124 * GDB now supports the compilation and injection of source code into
125 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
126 to compile the source code to object code, and if successful, inject
127 and execute that code within the current context of the inferior.
128 Currently the C language is supported. The commands used to
129 interface with this new feature are:
131 compile code [-raw|-r] [--] [source code]
132 compile file [-raw|-r] filename
136 demangle [-l language] [--] name
137 Demangle "name" in the specified language, or the current language
138 if elided. This command is renamed from the "maint demangle" command.
139 The latter is kept as a no-op to avoid "maint demangle" being interpreted
140 as "maint demangler-warning".
142 queue-signal signal-name-or-number
143 Queue a signal to be delivered to the thread when it is resumed.
145 add-auto-load-scripts-directory directory
146 Add entries to the list of directories from which to load auto-loaded
149 maint print user-registers
150 List all currently available "user" registers.
152 compile code [-r|-raw] [--] [source code]
153 Compile, inject, and execute in the inferior the executable object
154 code produced by compiling the provided source code.
156 compile file [-r|-raw] filename
157 Compile and inject into the inferior the executable object code
158 produced by compiling the source code stored in the filename
161 * On resume, GDB now always passes the signal the program had stopped
162 for to the thread the signal was sent to, even if the user changed
163 threads before resuming. Previously GDB would often (but not
164 always) deliver the signal to the thread that happens to be current
167 * Conversely, the "signal" command now consistently delivers the
168 requested signal to the current thread. GDB now asks for
169 confirmation if the program had stopped for a signal and the user
170 switched threads meanwhile.
172 * "breakpoint always-inserted" modes "off" and "auto" merged.
174 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
175 won't remove breakpoints from the target until all threads stop,
176 even in non-stop mode. The "auto" mode has been removed, and "off"
177 is now the default mode.
181 set debug symbol-lookup
182 show debug symbol-lookup
183 Control display of debugging info regarding symbol lookup.
187 ** The -list-thread-groups command outputs an exit-code field for
188 inferiors that have exited.
192 MIPS SDE mips*-sde*-elf*
196 Support for these obsolete configurations has been removed.
198 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
199 SGI Irix-5.x mips-*-irix5*
200 SGI Irix-6.x mips-*-irix6*
201 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
202 VAX running Ultrix vax-*-ultrix*
204 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
205 and "assf"), have been removed. Use the "sharedlibrary" command, or
206 its alias "share", instead.
208 *** Changes in GDB 7.8
210 * New command line options
213 This is an alias for the --data-directory option.
215 * GDB supports printing and modifying of variable length automatic arrays
216 as specified in ISO C99.
218 * The ARM simulator now supports instruction level tracing
219 with or without disassembly.
223 GDB now has support for scripting using Guile. Whether this is
224 available is determined at configure time.
225 Guile version 2.0 or greater is required.
226 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
228 * New commands (for set/show, see "New options" below)
232 Invoke CODE by passing it to the Guile interpreter.
236 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
238 info auto-load guile-scripts [regexp]
239 Print the list of automatically loaded Guile scripts.
241 * The source command is now capable of sourcing Guile scripts.
242 This feature is dependent on the debugger being built with Guile support.
246 set print symbol-loading (off|brief|full)
247 show print symbol-loading
248 Control whether to print informational messages when loading symbol
249 information for a file. The default is "full", but when debugging
250 programs with large numbers of shared libraries the amount of output
253 set guile print-stack (none|message|full)
254 show guile print-stack
255 Show a stack trace when an error is encountered in a Guile script.
257 set auto-load guile-scripts (on|off)
258 show auto-load guile-scripts
259 Control auto-loading of Guile script files.
261 maint ada set ignore-descriptive-types (on|off)
262 maint ada show ignore-descriptive-types
263 Control whether the debugger should ignore descriptive types in Ada
264 programs. The default is not to ignore the descriptive types. See
265 the user manual for more details on descriptive types and the intended
266 usage of this option.
268 set auto-connect-native-target
270 Control whether GDB is allowed to automatically connect to the
271 native target for the run, attach, etc. commands when not connected
272 to any target yet. See also "target native" below.
274 set record btrace replay-memory-access (read-only|read-write)
275 show record btrace replay-memory-access
276 Control what memory accesses are allowed during replay.
278 maint set target-async (on|off)
279 maint show target-async
280 This controls whether GDB targets operate in synchronous or
281 asynchronous mode. Normally the default is asynchronous, if it is
282 available; but this can be changed to more easily debug problems
283 occurring only in synchronous mode.
285 set mi-async (on|off)
287 Control whether MI asynchronous mode is preferred. This supersedes
288 "set target-async" of previous GDB versions.
290 * "set target-async" is deprecated as a CLI option and is now an alias
291 for "set mi-async" (only puts MI into async mode).
293 * Background execution commands (e.g., "c&", "s&", etc.) are now
294 possible ``out of the box'' if the target supports them. Previously
295 the user would need to explicitly enable the possibility with the
296 "set target-async on" command.
298 * New features in the GDB remote stub, GDBserver
300 ** New option --debug-format=option1[,option2,...] allows one to add
301 additional text to each output. At present only timestamps
302 are supported: --debug-format=timestamps.
303 Timestamps can also be turned on with the
304 "monitor set debug-format timestamps" command from GDB.
306 * The 'record instruction-history' command now starts counting instructions
307 at one. This also affects the instruction ranges reported by the
308 'record function-call-history' command when given the /i modifier.
310 * The command 'record function-call-history' supports a new modifier '/c' to
311 indent the function names based on their call stack depth.
312 The fields for the '/i' and '/l' modifier have been reordered.
313 The source line range is now prefixed with 'at'.
314 The instruction range is now prefixed with 'inst'.
315 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
316 "record instruction-history" and "list" commands.
318 * The ranges given as arguments to the 'record function-call-history' and
319 'record instruction-history' commands are now inclusive.
321 * The btrace record target now supports the 'record goto' command.
322 For locations inside the execution trace, the back trace is computed
323 based on the information stored in the execution trace.
325 * The btrace record target supports limited reverse execution and replay.
326 The target does not record data and therefore does not allow reading
329 * The "catch syscall" command now works on s390*-linux* targets.
331 * The "compare-sections" command is no longer specific to target
332 remote. It now works with all targets.
334 * All native targets are now consistently called "native".
335 Consequently, the "target child", "target GNU", "target djgpp",
336 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
337 commands have been replaced with "target native". The QNX/NTO port
338 leaves the "procfs" target in place and adds a "native" target for
339 consistency with other ports. The impact on users should be minimal
340 as these commands previously either throwed an error, or were
341 no-ops. The target's name is visible in the output of the following
342 commands: "help target", "info target", "info files", "maint print
345 * The "target native" command now connects to the native target. This
346 can be used to launch native programs even when "set
347 auto-connect-native-target" is set to off.
349 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.
351 * Support for Intel(R) AVX-512 registers on GNU/Linux.
352 Support displaying and modifying Intel(R) AVX-512 registers
353 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
357 qXfer:btrace:read's annex
358 The qXfer:btrace:read packet supports a new annex 'delta' to read
359 branch trace incrementally.
363 ** Valid Python operations on gdb.Value objects representing
364 structs/classes invoke the corresponding overloaded operators if
366 ** New `Xmethods' feature in the Python API. Xmethods are
367 additional methods or replacements for existing methods of a C++
368 class. This feature is useful for those cases where a method
369 defined in C++ source code could be inlined or optimized out by
370 the compiler, making it unavailable to GDB.
373 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
375 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
376 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
377 its alias "share", instead.
379 * The commands "set remotebaud" and "show remotebaud" are no longer
380 supported. Use "set serial baud" and "show serial baud" (respectively)
385 ** A new option "-gdb-set mi-async" replaces "-gdb-set
386 target-async". The latter is left as a deprecated alias of the
387 former for backward compatibility. If the target supports it,
388 CLI background execution commands are now always possible by
389 default, independently of whether the frontend stated a
390 preference for asynchronous execution with "-gdb-set mi-async".
391 Previously "-gdb-set target-async off" affected both MI execution
392 commands and CLI execution commands.
394 *** Changes in GDB 7.7
396 * Improved support for process record-replay and reverse debugging on
397 arm*-linux* targets. Support for thumb32 and syscall instruction
398 recording has been added.
400 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
402 * GDB now supports Fission DWP file format version 2.
403 http://gcc.gnu.org/wiki/DebugFission
405 * New convenience function "$_isvoid", to check whether an expression
406 is void. A void expression is an expression where the type of the
407 result is "void". For example, some convenience variables may be
408 "void" when evaluated (e.g., "$_exitcode" before the execution of
409 the program being debugged; or an undefined convenience variable).
410 Another example, when calling a function whose return type is
413 * The "maintenance print objfiles" command now takes an optional regexp.
415 * The "catch syscall" command now works on arm*-linux* targets.
417 * GDB now consistently shows "<not saved>" when printing values of
418 registers the debug info indicates have not been saved in the frame
419 and there's nowhere to retrieve them from
420 (callee-saved/call-clobbered registers):
425 (gdb) info registers rax
428 Before, the former would print "<optimized out>", and the latter
429 "*value not available*".
431 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
436 ** Frame filters and frame decorators have been added.
437 ** Temporary breakpoints are now supported.
438 ** Line tables representation has been added.
439 ** New attribute 'parent_type' for gdb.Field objects.
440 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
441 ** New attribute 'name' for gdb.Type objects.
445 Nios II ELF nios2*-*-elf
446 Nios II GNU/Linux nios2*-*-linux
447 Texas Instruments MSP430 msp430*-*-elf
449 * Removed native configurations
451 Support for these a.out NetBSD and OpenBSD obsolete configurations has
452 been removed. ELF variants of these configurations are kept supported.
454 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
455 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
456 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
457 i[34567]86-*-openbsd3.[0-3]
458 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
459 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
460 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
464 Like "catch throw", but catches a re-thrown exception.
466 Renamed from old "maint check-symtabs".
468 Perform consistency checks on symtabs.
470 Expand symtabs matching an optional regexp.
473 Display the details of GDB configure-time options.
475 maint set|show per-command
476 maint set|show per-command space
477 maint set|show per-command time
478 maint set|show per-command symtab
479 Enable display of per-command gdb resource usage.
481 remove-symbol-file FILENAME
482 remove-symbol-file -a ADDRESS
483 Remove a symbol file added via add-symbol-file. The file to remove
484 can be identified by its filename or by an address that lies within
485 the boundaries of this symbol file in memory.
488 info exceptions REGEXP
489 Display the list of Ada exceptions defined in the program being
490 debugged. If provided, only the exceptions whose names match REGEXP
495 set debug symfile off|on
497 Control display of debugging info regarding reading symbol files and
498 symbol tables within those files
500 set print raw frame-arguments
501 show print raw frame-arguments
502 Set/show whether to print frame arguments in raw mode,
503 disregarding any defined pretty-printers.
505 set remote trace-status-packet
506 show remote trace-status-packet
507 Set/show the use of remote protocol qTStatus packet.
511 Control display of debugging messages related to Nios II targets.
515 Control whether target-assisted range stepping is enabled.
517 set startup-with-shell
518 show startup-with-shell
519 Specifies whether Unix child processes are started via a shell or
524 Use the target memory cache for accesses to the code segment. This
525 improves performance of remote debugging (particularly disassembly).
527 * You can now use a literal value 'unlimited' for options that
528 interpret 0 or -1 as meaning "unlimited". E.g., "set
529 trace-buffer-size unlimited" is now an alias for "set
530 trace-buffer-size -1" and "set height unlimited" is now an alias for
533 * The "set debug symtab-create" debugging option of GDB has been changed to
534 accept a verbosity level. 0 means "off", 1 provides basic debugging
535 output, and values of 2 or greater provides more verbose output.
537 * New command-line options
539 Display the details of GDB configure-time options.
541 * The command 'tsave' can now support new option '-ctf' to save trace
542 buffer in Common Trace Format.
544 * Newly installed $prefix/bin/gcore acts as a shell interface for the
547 * GDB now implements the the C++ 'typeid' operator.
549 * The new convenience variable $_exception holds the exception being
550 thrown or caught at an exception-related catchpoint.
552 * The exception-related catchpoints, like "catch throw", now accept a
553 regular expression which can be used to filter exceptions by type.
555 * The new convenience variable $_exitsignal is automatically set to
556 the terminating signal number when the program being debugged dies
557 due to an uncaught signal.
561 ** All MI commands now accept an optional "--language" option.
562 Support for this feature can be verified by using the "-list-features"
563 command, which should contain "language-option".
565 ** The new command -info-gdb-mi-command allows the user to determine
566 whether a GDB/MI command is supported or not.
568 ** The "^error" result record returned when trying to execute an undefined
569 GDB/MI command now provides a variable named "code" whose content is the
570 "undefined-command" error code. Support for this feature can be verified
571 by using the "-list-features" command, which should contain
572 "undefined-command-error-code".
574 ** The -trace-save MI command can optionally save trace buffer in Common
577 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
579 ** The command -data-list-register-values now accepts an optional
580 "--skip-unavailable" option. When used, only the available registers
583 ** The new command -trace-frame-collected dumps collected variables,
584 computed expressions, tvars, memory and registers in a traceframe.
586 ** The commands -stack-list-locals, -stack-list-arguments and
587 -stack-list-variables now accept an option "--skip-unavailable".
588 When used, only the available locals or arguments are displayed.
590 ** The -exec-run command now accepts an optional "--start" option.
591 When used, the command follows the same semantics as the "start"
592 command, stopping the program's execution at the start of its
593 main subprogram. Support for this feature can be verified using
594 the "-list-features" command, which should contain
595 "exec-run-start-option".
597 ** The new commands -catch-assert and -catch-exceptions insert
598 catchpoints stopping the program when Ada exceptions are raised.
600 ** The new command -info-ada-exceptions provides the equivalent of
601 the new "info exceptions" command.
603 * New system-wide configuration scripts
604 A GDB installation now provides scripts suitable for use as system-wide
605 configuration scripts for the following systems:
609 * GDB now supports target-assigned range stepping with remote targets.
610 This improves the performance of stepping source lines by reducing
611 the number of control packets from/to GDB. See "New remote packets"
614 * GDB now understands the element 'tvar' in the XML traceframe info.
615 It has the id of the collected trace state variables.
617 * On S/390 targets that provide the transactional-execution feature,
618 the program interruption transaction diagnostic block (TDB) is now
619 represented as a number of additional "registers" in GDB.
625 The vCont packet supports a new 'r' action, that tells the remote
626 stub to step through an address range itself, without GDB
627 involvemement at each single-step.
629 qXfer:libraries-svr4:read's annex
630 The previously unused annex of the qXfer:libraries-svr4:read packet
631 is now used to support passing an argument list. The remote stub
632 reports support for this argument list to GDB's qSupported query.
633 The defined arguments are "start" and "prev", used to reduce work
634 necessary for library list updating, resulting in significant
637 * New features in the GDB remote stub, GDBserver
639 ** GDBserver now supports target-assisted range stepping. Currently
640 enabled on x86/x86_64 GNU/Linux targets.
642 ** GDBserver now adds element 'tvar' in the XML in the reply to
643 'qXfer:traceframe-info:read'. It has the id of the collected
644 trace state variables.
646 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
649 * New 'z' formatter for printing and examining memory, this displays the
650 value as hexadecimal zero padded on the left to the size of the type.
652 * GDB can now use Windows x64 unwinding data.
654 * The "set remotebaud" command has been replaced by "set serial baud".
655 Similarly, "show remotebaud" has been replaced by "show serial baud".
656 The "set remotebaud" and "show remotebaud" commands are still available
657 to provide backward compatibility with older versions of GDB.
659 *** Changes in GDB 7.6
661 * Target record has been renamed to record-full.
662 Record/replay is now enabled with the "record full" command.
663 This also affects settings that are associated with full record/replay
664 that have been moved from "set/show record" to "set/show record full":
666 set|show record full insn-number-max
667 set|show record full stop-at-limit
668 set|show record full memory-query
670 * A new record target "record-btrace" has been added. The new target
671 uses hardware support to record the control-flow of a process. It
672 does not support replaying the execution, but it implements the
673 below new commands for investigating the recorded execution log.
674 This new recording method can be enabled using:
678 The "record-btrace" target is only available on Intel Atom processors
679 and requires a Linux kernel 2.6.32 or later.
681 * Two new commands have been added for record/replay to give information
682 about the recorded execution without having to replay the execution.
683 The commands are only supported by "record btrace".
685 record instruction-history prints the execution history at
686 instruction granularity
688 record function-call-history prints the execution history at
691 * New native configurations
693 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
694 FreeBSD/powerpc powerpc*-*-freebsd
695 x86_64/Cygwin x86_64-*-cygwin*
696 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
700 ARM AArch64 aarch64*-*-elf
701 ARM AArch64 GNU/Linux aarch64*-*-linux
702 Lynx 178 PowerPC powerpc-*-lynx*178
703 x86_64/Cygwin x86_64-*-cygwin*
704 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
706 * If the configured location of system.gdbinit file (as given by the
707 --with-system-gdbinit option at configure time) is in the
708 data-directory (as specified by --with-gdb-datadir at configure
709 time) or in one of its subdirectories, then GDB will look for the
710 system-wide init file in the directory specified by the
711 --data-directory command-line option.
713 * New command line options:
715 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
716 other initialization files, unlike -nx which disables all of them.
718 * Removed command line options
720 -epoch This was used by the gdb mode in Epoch, an ancient fork of
723 * The 'ptype' and 'whatis' commands now accept an argument to control
726 * 'info proc' now works on some core files.
730 ** Vectors can be created with gdb.Type.vector.
732 ** Python's atexit.register now works in GDB.
734 ** Types can be pretty-printed via a Python API.
736 ** Python 3 is now supported (in addition to Python 2.4 or later)
738 ** New class gdb.Architecture exposes GDB's internal representation
739 of architecture in the Python API.
741 ** New method Frame.architecture returns the gdb.Architecture object
742 corresponding to the frame's architecture.
744 * New Python-based convenience functions:
746 ** $_memeq(buf1, buf2, length)
747 ** $_streq(str1, str2)
749 ** $_regex(str, regex)
751 * The 'cd' command now defaults to using '~' (the home directory) if not
754 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
755 default for GCC since November 2000.
757 * The command 'forward-search' can now be abbreviated as 'fo'.
759 * The command 'info tracepoints' can now display 'installed on target'
760 or 'not installed on target' for each non-pending location of tracepoint.
762 * New configure options
764 --enable-libmcheck/--disable-libmcheck
765 By default, development versions are built with -lmcheck on hosts
766 that support it, in order to help track memory corruption issues.
767 Release versions, on the other hand, are built without -lmcheck
768 by default. The --enable-libmcheck/--disable-libmcheck configure
769 options allow the user to override that default.
770 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
771 This configure option allows the user to build GDB with
772 libbabeltrace using which GDB can read Common Trace Format data.
774 * New commands (for set/show, see "New options" below)
777 Catch signals. This is similar to "handle", but allows commands and
778 conditions to be attached.
781 List the BFDs known to GDB.
783 python-interactive [command]
785 Start a Python interactive prompt, or evaluate the optional command
786 and print the result of expressions.
789 "py" is a new alias for "python".
791 enable type-printer [name]...
792 disable type-printer [name]...
793 Enable or disable type printers.
797 ** For the Renesas Super-H architecture, the "regs" command has been removed
798 (has been deprecated in GDB 7.5), and "info all-registers" should be used
803 set print type methods (on|off)
804 show print type methods
805 Control whether method declarations are displayed by "ptype".
806 The default is to show them.
808 set print type typedefs (on|off)
809 show print type typedefs
810 Control whether typedef definitions are displayed by "ptype".
811 The default is to show them.
813 set filename-display basename|relative|absolute
814 show filename-display
815 Control the way in which filenames is displayed.
816 The default is "relative", which preserves previous behavior.
818 set trace-buffer-size
819 show trace-buffer-size
820 Request target to change the size of trace buffer.
822 set remote trace-buffer-size-packet auto|on|off
823 show remote trace-buffer-size-packet
824 Control the use of the remote protocol `QTBuffer:size' packet.
828 Control display of debugging messages related to ARM AArch64.
831 set debug coff-pe-read
832 show debug coff-pe-read
833 Control display of debugging messages related to reading of COFF/PE
838 Control display of debugging messages related to Mach-O symbols
841 set debug notification
842 show debug notification
843 Control display of debugging info for async remote notification.
847 ** Command parameter changes are now notified using new async record
848 "=cmd-param-changed".
849 ** Trace frame changes caused by command "tfind" are now notified using
850 new async record "=traceframe-changed".
851 ** The creation, deletion and modification of trace state variables
852 are now notified using new async records "=tsv-created",
853 "=tsv-deleted" and "=tsv-modified".
854 ** The start and stop of process record are now notified using new
855 async record "=record-started" and "=record-stopped".
856 ** Memory changes are now notified using new async record
858 ** The data-disassemble command response will include a "fullname" field
859 containing the absolute file name when source has been requested.
860 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
861 command, to allow pattern filling of memory areas.
862 ** New commands "-catch-load"/"-catch-unload" added for intercepting
863 library load/unload events.
864 ** The response to breakpoint commands and breakpoint async records
865 includes an "installed" field containing a boolean state about each
866 non-pending tracepoint location is whether installed on target or not.
867 ** Output of the "-trace-status" command includes a "trace-file" field
868 containing the name of the trace file being examined. This field is
869 optional, and only present when examining a trace file.
870 ** The "fullname" field is now always present along with the "file" field,
871 even if the file cannot be found by GDB.
873 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
874 You must have the LZMA library available when configuring GDB for this
875 feature to be enabled. For more information, see:
876 http://fedoraproject.org/wiki/Features/MiniDebugInfo
881 Set the size of trace buffer. The remote stub reports support for this
882 packet to gdb's qSupported query.
885 Enable Branch Trace Store (BTS)-based branch tracing for the current
886 thread. The remote stub reports support for this packet to gdb's
890 Disable branch tracing for the current thread. The remote stub reports
891 support for this packet to gdb's qSupported query.
894 Read the traced branches for the current thread. The remote stub
895 reports support for this packet to gdb's qSupported query.
897 *** Changes in GDB 7.5
899 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
900 for more x32 ABI info.
902 * GDB now supports access to MIPS DSP registers on Linux targets.
904 * GDB now supports debugging microMIPS binaries.
906 * The "info os" command on GNU/Linux can now display information on
907 several new classes of objects managed by the operating system:
908 "info os procgroups" lists process groups
909 "info os files" lists file descriptors
910 "info os sockets" lists internet-domain sockets
911 "info os shm" lists shared-memory regions
912 "info os semaphores" lists semaphores
913 "info os msg" lists message queues
914 "info os modules" lists loaded kernel modules
916 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
917 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
918 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
919 options and inspect the probe arguments using the new $_probe_arg family
920 of convenience variables. You can obtain more information about SystemTap
921 in <http://sourceware.org/systemtap/>.
923 * GDB now supports reversible debugging on ARM, it allows you to
924 debug basic ARM and THUMB instructions, and provides
925 record/replay support.
927 * The option "symbol-reloading" has been deleted as it is no longer used.
931 ** GDB commands implemented in Python can now be put in command class
934 ** The "maint set python print-stack on|off" is now deleted.
936 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
937 apply "flag enum"-style pretty-printing to any enum.
939 ** gdb.lookup_symbol can now work when there is no current frame.
941 ** gdb.Symbol now has a 'line' attribute, holding the line number in
942 the source at which the symbol was defined.
944 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
945 method 'value'. The former indicates whether the symbol needs a
946 frame in order to compute its value, and the latter computes the
949 ** A new method 'referenced_value' on gdb.Value objects which can
950 dereference pointer as well as C++ reference values.
952 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
953 which return the global and static blocks (as gdb.Block objects),
954 of the underlying symbol table, respectively.
956 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
957 object associated with a PC value.
959 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
960 of the address range occupied by code for the current source line.
962 * Go language support.
963 GDB now supports debugging programs written in the Go programming
966 * GDBserver now supports stdio connections.
967 E.g. (gdb) target remote | ssh myhost gdbserver - hello
969 * The binary "gdbtui" can no longer be built or installed.
970 Use "gdb -tui" instead.
972 * GDB will now print "flag" enums specially. A flag enum is one where
973 all the enumerator values have no bits in common when pairwise
974 "and"ed. When printing a value whose type is a flag enum, GDB will
975 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
976 (gdb) print (enum E) 3
979 * The filename part of a linespec will now match trailing components
980 of a source file name. For example, "break gcc/expr.c:1000" will
981 now set a breakpoint in build/gcc/expr.c, but not
984 * The "info proc" and "generate-core-file" commands will now also
985 work on remote targets connected to GDBserver on Linux.
987 * The command "info catch" has been removed. It has been disabled
990 * The "catch exception" and "catch assert" commands now accept
991 a condition at the end of the command, much like the "break"
992 command does. For instance:
994 (gdb) catch exception Constraint_Error if Barrier = True
996 Previously, it was possible to add a condition to such catchpoints,
997 but it had to be done as a second step, after the catchpoint had been
998 created, using the "condition" command.
1000 * The "info static-tracepoint-marker" command will now also work on
1001 native Linux targets with in-process agent.
1003 * GDB can now set breakpoints on inlined functions.
1005 * The .gdb_index section has been updated to include symbols for
1006 inlined functions. GDB will ignore older .gdb_index sections by
1007 default, which could cause symbol files to be loaded more slowly
1008 until their .gdb_index sections can be recreated. The new command
1009 "set use-deprecated-index-sections on" will cause GDB to use any older
1010 .gdb_index sections it finds. This will restore performance, but the
1011 ability to set breakpoints on inlined functions will be lost in symbol
1012 files with older .gdb_index sections.
1014 The .gdb_index section has also been updated to record more information
1015 about each symbol. This speeds up the "info variables", "info functions"
1016 and "info types" commands when used with programs having the .gdb_index
1017 section, as well as speeding up debugging with shared libraries using
1018 the .gdb_index section.
1020 * Ada support for GDB/MI Variable Objects has been added.
1022 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1027 ** New command -info-os is the MI equivalent of "info os".
1029 ** Output logs ("set logging" and related) now include MI output.
1033 ** "set use-deprecated-index-sections on|off"
1034 "show use-deprecated-index-sections on|off"
1035 Controls the use of deprecated .gdb_index sections.
1037 ** "catch load" and "catch unload" can be used to stop when a shared
1038 library is loaded or unloaded, respectively.
1040 ** "enable count" can be used to auto-disable a breakpoint after
1043 ** "info vtbl" can be used to show the virtual method tables for
1044 C++ and Java objects.
1046 ** "explore" and its sub commands "explore value" and "explore type"
1047 can be used to recursively explore values and types of
1048 expressions. These commands are available only if GDB is
1049 configured with '--with-python'.
1051 ** "info auto-load" shows status of all kinds of auto-loaded files,
1052 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1053 sequences of commands files, "info auto-load python-scripts"
1054 shows status of auto-loading Python script files,
1055 "info auto-load local-gdbinit" shows status of loading init file
1056 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1057 status of inferior specific thread debugging shared library loading.
1059 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1060 and "show auto-load-scripts" commands have been deprecated, use their
1061 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1062 and "show auto-load python-scripts" counterparts instead.
1064 ** "dprintf location,format,args..." creates a dynamic printf, which
1065 is basically a breakpoint that does a printf and immediately
1066 resumes your program's execution, so it is like a printf that you
1067 can insert dynamically at runtime instead of at compiletime.
1069 ** "set print symbol"
1071 Controls whether GDB attempts to display the symbol, if any,
1072 corresponding to addresses it prints. This defaults to "on", but
1073 you can set it to "off" to restore GDB's previous behavior.
1075 * Deprecated commands
1077 ** For the Renesas Super-H architecture, the "regs" command has been
1078 deprecated, and "info all-registers" should be used instead.
1082 Renesas RL78 rl78-*-elf
1083 HP OpenVMS ia64 ia64-hp-openvms*
1085 * GDBserver supports evaluation of breakpoint conditions. When
1086 support is advertised by GDBserver, GDB may be told to send the
1087 breakpoint conditions in bytecode form to GDBserver. GDBserver
1088 will only report the breakpoint trigger to GDB when its condition
1093 set mips compression
1094 show mips compression
1095 Select the compressed ISA encoding used in functions that have no symbol
1096 information available. The encoding can be set to either of:
1099 and is updated automatically from ELF file flags if available.
1101 set breakpoint condition-evaluation
1102 show breakpoint condition-evaluation
1103 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1104 GDBserver ("target"). Default option "auto" chooses the most efficient
1106 This option can improve debugger efficiency depending on the speed of the
1110 Disable auto-loading globally.
1113 Show auto-loading setting of all kinds of auto-loaded files.
1115 set auto-load gdb-scripts on|off
1116 show auto-load gdb-scripts
1117 Control auto-loading of GDB canned sequences of commands files.
1119 set auto-load python-scripts on|off
1120 show auto-load python-scripts
1121 Control auto-loading of Python script files.
1123 set auto-load local-gdbinit on|off
1124 show auto-load local-gdbinit
1125 Control loading of init file (.gdbinit) from current directory.
1127 set auto-load libthread-db on|off
1128 show auto-load libthread-db
1129 Control auto-loading of inferior specific thread debugging shared library.
1131 set auto-load scripts-directory <dir1>[:<dir2>...]
1132 show auto-load scripts-directory
1133 Set a list of directories from which to load auto-loaded scripts.
1134 Automatically loaded Python scripts and GDB scripts are located in one
1135 of the directories listed by this option.
1136 The delimiter (':' above) may differ according to the host platform.
1138 set auto-load safe-path <dir1>[:<dir2>...]
1139 show auto-load safe-path
1140 Set a list of directories from which it is safe to auto-load files.
1141 The delimiter (':' above) may differ according to the host platform.
1143 set debug auto-load on|off
1144 show debug auto-load
1145 Control display of debugging info for auto-loading the files above.
1147 set dprintf-style gdb|call|agent
1149 Control the way in which a dynamic printf is performed; "gdb"
1150 requests a GDB printf command, while "call" causes dprintf to call a
1151 function in the inferior. "agent" requests that the target agent
1152 (such as GDBserver) do the printing.
1154 set dprintf-function <expr>
1155 show dprintf-function
1156 set dprintf-channel <expr>
1157 show dprintf-channel
1158 Set the function and optional first argument to the call when using
1159 the "call" style of dynamic printf.
1161 set disconnected-dprintf on|off
1162 show disconnected-dprintf
1163 Control whether agent-style dynamic printfs continue to be in effect
1164 after GDB disconnects.
1166 * New configure options
1168 --with-auto-load-dir
1169 Configure default value for the 'set auto-load scripts-directory'
1170 setting above. It defaults to '$debugdir:$datadir/auto-load',
1171 $debugdir representing global debugging info directories (available
1172 via 'show debug-file-directory') and $datadir representing GDB's data
1173 directory (available via 'show data-directory').
1175 --with-auto-load-safe-path
1176 Configure default value for the 'set auto-load safe-path' setting
1177 above. It defaults to the --with-auto-load-dir setting.
1179 --without-auto-load-safe-path
1180 Set 'set auto-load safe-path' to '/', effectively disabling this
1183 * New remote packets
1185 z0/z1 conditional breakpoints extension
1187 The z0/z1 breakpoint insertion packets have been extended to carry
1188 a list of conditional expressions over to the remote stub depending on the
1189 condition evaluation mode. The use of this extension can be controlled
1190 via the "set remote conditional-breakpoints-packet" command.
1194 Specify the signals which the remote stub may pass to the debugged
1195 program without GDB involvement.
1197 * New command line options
1199 --init-command=FILE, -ix Like --command, -x but execute it
1200 before loading inferior.
1201 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1202 execute it before loading inferior.
1204 *** Changes in GDB 7.4
1206 * GDB now handles ambiguous linespecs more consistently; the existing
1207 FILE:LINE support has been expanded to other types of linespecs. A
1208 breakpoint will now be set on all matching locations in all
1209 inferiors, and locations will be added or removed according to
1212 * GDB now allows you to skip uninteresting functions and files when
1213 stepping with the "skip function" and "skip file" commands.
1215 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1216 and "show remote hardware-watchpoint-length-limit". These allows to
1217 set or show the maximum length limit (in bytes) of a remote
1218 target hardware watchpoint.
1220 This allows e.g. to use "unlimited" hardware watchpoints with the
1221 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1222 watchpoints are slower than real hardware watchpoints but are
1223 significantly faster than gdb software watchpoints.
1227 ** The register_pretty_printer function in module gdb.printing now takes
1228 an optional `replace' argument. If True, the new printer replaces any
1231 ** The "maint set python print-stack on|off" command has been
1232 deprecated and will be deleted in GDB 7.5.
1233 A new command: "set python print-stack none|full|message" has
1234 replaced it. Additionally, the default for "print-stack" is
1235 now "message", which just prints the error message without
1238 ** A prompt substitution hook (prompt_hook) is now available to the
1241 ** A new Python module, gdb.prompt has been added to the GDB Python
1242 modules library. This module provides functionality for
1243 escape sequences in prompts (used by set/show
1244 extended-prompt). These escape sequences are replaced by their
1245 corresponding value.
1247 ** Python commands and convenience-functions located in
1248 'data-directory'/python/gdb/command and
1249 'data-directory'/python/gdb/function are now automatically loaded
1252 ** Blocks now provide four new attributes. global_block and
1253 static_block will return the global and static blocks
1254 respectively. is_static and is_global are boolean attributes
1255 that indicate if the block is one of those two types.
1257 ** Symbols now provide the "type" attribute, the type of the symbol.
1259 ** The "gdb.breakpoint" function has been deprecated in favor of
1262 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1263 of a function. This class is based on the "finish" command
1264 available in the CLI.
1266 ** Type objects for struct and union types now allow access to
1267 the fields using standard Python dictionary (mapping) methods.
1268 For example, "some_type['myfield']" now works, as does
1269 "some_type.items()".
1271 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1274 ** A new function, "deep_items" has been added to the gdb.types
1275 module in the GDB Python modules library. This function returns
1276 an iterator over the fields of a struct or union type. Unlike
1277 the standard Python "iteritems" method, it will recursively traverse
1278 any anonymous fields.
1282 ** "*stopped" events can report several new "reason"s, such as
1285 ** Breakpoint changes are now notified using new async records, like
1286 "=breakpoint-modified".
1288 ** New command -ada-task-info.
1290 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1291 $sdir specifies the default system locations of shared libraries.
1292 $pdir specifies the directory where the libpthread used by the application
1295 GDB no longer looks in $sdir and $pdir after it has searched the directories
1296 mentioned in libthread-db-search-path. If you want to search those
1297 directories, they must be specified in libthread-db-search-path.
1298 The default value of libthread-db-search-path on GNU/Linux and Solaris
1299 systems is now "$sdir:$pdir".
1301 $pdir is not supported by gdbserver, it is currently ignored.
1302 $sdir is supported by gdbserver.
1304 * New configure option --with-iconv-bin.
1305 When using the internationalization support like the one in the GNU C
1306 library, GDB will invoke the "iconv" program to get a list of supported
1307 character sets. If this program lives in a non-standard location, one can
1308 use this option to specify where to find it.
1310 * When natively debugging programs on PowerPC BookE processors running
1311 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1312 watchpoints, which specify a mask in addition to an address to watch.
1313 The mask specifies that some bits of an address (the bits which are
1314 reset in the mask) should be ignored when matching the address accessed
1315 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1316 section in the user manual for more details.
1318 * The new option --once causes GDBserver to stop listening for connections once
1319 the first connection is made. The listening port used by GDBserver will
1320 become available after that.
1322 * New commands "info macros" and "alias" have been added.
1324 * New function parameters suffix @entry specifies value of function parameter
1325 at the time the function got called. Entry values are available only since
1331 "!" is now an alias of the "shell" command.
1332 Note that no space is needed between "!" and SHELL COMMAND.
1336 watch EXPRESSION mask MASK_VALUE
1337 The watch command now supports the mask argument which allows creation
1338 of masked watchpoints, if the current architecture supports this feature.
1340 info auto-load-scripts [REGEXP]
1341 This command was formerly named "maintenance print section-scripts".
1342 It is now generally useful and is no longer a maintenance-only command.
1344 info macro [-all] [--] MACRO
1345 The info macro command has new options `-all' and `--'. The first for
1346 printing all definitions of a macro. The second for explicitly specifying
1347 the end of arguments and the beginning of the macro name in case the macro
1348 name starts with a hyphen.
1350 collect[/s] EXPRESSIONS
1351 The tracepoint collect command now takes an optional modifier "/s"
1352 that directs it to dereference pointer-to-character types and
1353 collect the bytes of memory up to a zero byte. The behavior is
1354 similar to what you see when you use the regular print command on a
1355 string. An optional integer following the "/s" sets a bound on the
1356 number of bytes that will be collected.
1359 The trace start command now interprets any supplied arguments as a
1360 note to be recorded with the trace run, with an effect similar to
1361 setting the variable trace-notes.
1364 The trace stop command now interprets any arguments as a note to be
1365 mentioned along with the tstatus report that the trace was stopped
1366 with a command. The effect is similar to setting the variable
1369 * Tracepoints can now be enabled and disabled at any time after a trace
1370 experiment has been started using the standard "enable" and "disable"
1371 commands. It is now possible to start a trace experiment with no enabled
1372 tracepoints; GDB will display a warning, but will allow the experiment to
1373 begin, assuming that tracepoints will be enabled as needed while the trace
1376 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1377 locations with 4-byte instructions, when they were previously
1378 limited to locations with instructions of 5 bytes or longer.
1382 set debug dwarf2-read
1383 show debug dwarf2-read
1384 Turns on or off display of debugging messages related to reading
1385 DWARF debug info. The default is off.
1387 set debug symtab-create
1388 show debug symtab-create
1389 Turns on or off display of debugging messages related to symbol table
1390 creation. The default is off.
1393 show extended-prompt
1394 Set the GDB prompt, and allow escape sequences to be inserted to
1395 display miscellaneous information (see 'help set extended-prompt'
1396 for the list of sequences). This prompt (and any information
1397 accessed through the escape sequences) is updated every time the
1398 prompt is displayed.
1400 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1401 show print entry-values
1402 Set printing of frame argument values at function entry. In some cases
1403 GDB can determine the value of function argument which was passed by the
1404 function caller, even if the value was modified inside the called function.
1406 set debug entry-values
1407 show debug entry-values
1408 Control display of debugging info for determining frame argument values at
1409 function entry and virtual tail call frames.
1411 set basenames-may-differ
1412 show basenames-may-differ
1413 Set whether a source file may have multiple base names.
1414 (A "base name" is the name of a file with the directory part removed.
1415 Example: The base name of "/home/user/hello.c" is "hello.c".)
1416 If set, GDB will canonicalize file names (e.g., expand symlinks)
1417 before comparing them. Canonicalization is an expensive operation,
1418 but it allows the same file be known by more than one base name.
1419 If not set (the default), all source files are assumed to have just
1420 one base name, and gdb will do file name comparisons more efficiently.
1426 Set a user name and notes for the current and any future trace runs.
1427 This is useful for long-running and/or disconnected traces, to
1428 inform others (or yourself) as to who is running the trace, supply
1429 contact information, or otherwise explain what is going on.
1431 set trace-stop-notes
1432 show trace-stop-notes
1433 Set a note attached to the trace run, that is displayed when the
1434 trace has been stopped by a tstop command. This is useful for
1435 instance as an explanation, if you are stopping a trace run that was
1436 started by someone else.
1438 * New remote packets
1442 Dynamically enable a tracepoint in a started trace experiment.
1446 Dynamically disable a tracepoint in a started trace experiment.
1450 Set the user and notes of the trace run.
1454 Query the current status of a tracepoint.
1458 Query the minimum length of instruction at which a fast tracepoint may
1461 * Dcache size (number of lines) and line-size are now runtime-configurable
1462 via "set dcache line" and "set dcache line-size" commands.
1466 Texas Instruments TMS320C6x tic6x-*-*
1470 Renesas RL78 rl78-*-elf
1472 *** Changes in GDB 7.3.1
1474 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1476 *** Changes in GDB 7.3
1478 * GDB has a new command: "thread find [REGEXP]".
1479 It finds the thread id whose name, target id, or thread extra info
1480 matches the given regular expression.
1482 * The "catch syscall" command now works on mips*-linux* targets.
1484 * The -data-disassemble MI command now supports modes 2 and 3 for
1485 dumping the instruction opcodes.
1487 * New command line options
1489 -data-directory DIR Specify DIR as the "data-directory".
1490 This is mostly for testing purposes.
1492 * The "maint set python auto-load on|off" command has been renamed to
1493 "set auto-load-scripts on|off".
1495 * GDB has a new command: "set directories".
1496 It is like the "dir" command except that it replaces the
1497 source path list instead of augmenting it.
1499 * GDB now understands thread names.
1501 On GNU/Linux, "info threads" will display the thread name as set by
1502 prctl or pthread_setname_np.
1504 There is also a new command, "thread name", which can be used to
1505 assign a name internally for GDB to display.
1508 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1509 has been integrated into GDB.
1513 ** The function gdb.Write now accepts an optional keyword 'stream'.
1514 This keyword, when provided, will direct the output to either
1515 stdout, stderr, or GDB's logging output.
1517 ** Parameters can now be be sub-classed in Python, and in particular
1518 you may implement the get_set_doc and get_show_doc functions.
1519 This improves how Parameter set/show documentation is processed
1520 and allows for more dynamic content.
1522 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1523 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1524 have an is_valid method.
1526 ** Breakpoints can now be sub-classed in Python, and in particular
1527 you may implement a 'stop' function that is executed each time
1528 the inferior reaches that breakpoint.
1530 ** New function gdb.lookup_global_symbol looks up a global symbol.
1532 ** GDB values in Python are now callable if the value represents a
1533 function. For example, if 'some_value' represents a function that
1534 takes two integer parameters and returns a value, you can call
1535 that function like so:
1537 result = some_value (10,20)
1539 ** Module gdb.types has been added.
1540 It contains a collection of utilities for working with gdb.Types objects:
1541 get_basic_type, has_field, make_enum_dict.
1543 ** Module gdb.printing has been added.
1544 It contains utilities for writing and registering pretty-printers.
1545 New classes: PrettyPrinter, SubPrettyPrinter,
1546 RegexpCollectionPrettyPrinter.
1547 New function: register_pretty_printer.
1549 ** New commands "info pretty-printers", "enable pretty-printer" and
1550 "disable pretty-printer" have been added.
1552 ** gdb.parameter("directories") is now available.
1554 ** New function gdb.newest_frame returns the newest frame in the
1557 ** The gdb.InferiorThread class has a new "name" attribute. This
1558 holds the thread's name.
1560 ** Python Support for Inferior events.
1561 Python scripts can add observers to be notified of events
1562 occurring in the process being debugged.
1563 The following events are currently supported:
1564 - gdb.events.cont Continue event.
1565 - gdb.events.exited Inferior exited event.
1566 - gdb.events.stop Signal received, and Breakpoint hit events.
1570 ** GDB now puts template parameters in scope when debugging in an
1571 instantiation. For example, if you have:
1573 template<int X> int func (void) { return X; }
1575 then if you step into func<5>, "print X" will show "5". This
1576 feature requires proper debuginfo support from the compiler; it
1577 was added to GCC 4.5.
1579 ** The motion commands "next", "finish", "until", and "advance" now
1580 work better when exceptions are thrown. In particular, GDB will
1581 no longer lose control of the inferior; instead, the GDB will
1582 stop the inferior at the point at which the exception is caught.
1583 This functionality requires a change in the exception handling
1584 code that was introduced in GCC 4.5.
1586 * GDB now follows GCC's rules on accessing volatile objects when
1587 reading or writing target state during expression evaluation.
1588 One notable difference to prior behavior is that "print x = 0"
1589 no longer generates a read of x; the value of the assignment is
1590 now always taken directly from the value being assigned.
1592 * GDB now has some support for using labels in the program's source in
1593 linespecs. For instance, you can use "advance label" to continue
1594 execution to a label.
1596 * GDB now has support for reading and writing a new .gdb_index
1597 section. This section holds a fast index of DWARF debugging
1598 information and can be used to greatly speed up GDB startup and
1599 operation. See the documentation for `save gdb-index' for details.
1601 * The "watch" command now accepts an optional "-location" argument.
1602 When used, this causes GDB to watch the memory referred to by the
1603 expression. Such a watchpoint is never deleted due to it going out
1606 * GDB now supports thread debugging of core dumps on GNU/Linux.
1608 GDB now activates thread debugging using the libthread_db library
1609 when debugging GNU/Linux core dumps, similarly to when debugging
1610 live processes. As a result, when debugging a core dump file, GDB
1611 is now able to display pthread_t ids of threads. For example, "info
1612 threads" shows the same output as when debugging the process when it
1613 was live. In earlier releases, you'd see something like this:
1616 * 1 LWP 6780 main () at main.c:10
1618 While now you see this:
1621 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1623 It is also now possible to inspect TLS variables when debugging core
1626 When debugging a core dump generated on a machine other than the one
1627 used to run GDB, you may need to point GDB at the correct
1628 libthread_db library with the "set libthread-db-search-path"
1629 command. See the user manual for more details on this command.
1631 * When natively debugging programs on PowerPC BookE processors running
1632 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1633 which stop execution of the inferior whenever it executes an instruction
1634 at any address within the specified range. See the "PowerPC Embedded"
1635 section in the user manual for more details.
1637 * New features in the GDB remote stub, GDBserver
1639 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1640 and i686 LynxOS (version 5.x).
1642 ** GDBserver is now supported on Blackfin Linux.
1644 * New native configurations
1646 ia64 HP-UX ia64-*-hpux*
1650 Analog Devices, Inc. Blackfin Processor bfin-*
1652 * Ada task switching is now supported on sparc-elf targets when
1653 debugging a program using the Ravenscar Profile. For more information,
1654 see the "Tasking Support when using the Ravenscar Profile" section
1655 in the GDB user manual.
1657 * Guile support was removed.
1659 * New features in the GNU simulator
1661 ** The --map-info flag lists all known core mappings.
1663 ** CFI flashes may be simulated via the "cfi" device.
1665 *** Changes in GDB 7.2
1667 * Shared library support for remote targets by default
1669 When GDB is configured for a generic, non-OS specific target, like
1670 for example, --target=arm-eabi or one of the many *-*-elf targets,
1671 GDB now queries remote stubs for loaded shared libraries using the
1672 `qXfer:libraries:read' packet. Previously, shared library support
1673 was always disabled for such configurations.
1677 ** Argument Dependent Lookup (ADL)
1679 In C++ ADL lookup directs function search to the namespaces of its
1680 arguments even if the namespace has not been imported.
1690 Here the compiler will search for `foo' in the namespace of 'b'
1691 and find A::foo. GDB now supports this. This construct is commonly
1692 used in the Standard Template Library for operators.
1694 ** Improved User Defined Operator Support
1696 In addition to member operators, GDB now supports lookup of operators
1697 defined in a namespace and imported with a `using' directive, operators
1698 defined in the global scope, operators imported implicitly from an
1699 anonymous namespace, and the ADL operators mentioned in the previous
1701 GDB now also supports proper overload resolution for all the previously
1702 mentioned flavors of operators.
1704 ** static const class members
1706 Printing of static const class members that are initialized in the
1707 class definition has been fixed.
1709 * Windows Thread Information Block access.
1711 On Windows targets, GDB now supports displaying the Windows Thread
1712 Information Block (TIB) structure. This structure is visible either
1713 by using the new command `info w32 thread-information-block' or, by
1714 dereferencing the new convenience variable named `$_tlb', a
1715 thread-specific pointer to the TIB. This feature is also supported
1716 when remote debugging using GDBserver.
1718 * Static tracepoints
1720 Static tracepoints are calls in the user program into a tracing
1721 library. One such library is a port of the LTTng kernel tracer to
1722 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1723 When debugging with GDBserver, GDB now supports combining the GDB
1724 tracepoint machinery with such libraries. For example: the user can
1725 use GDB to probe a static tracepoint marker (a call from the user
1726 program into the tracing library) with the new "strace" command (see
1727 "New commands" below). This creates a "static tracepoint" in the
1728 breakpoint list, that can be manipulated with the same feature set
1729 as fast and regular tracepoints. E.g., collect registers, local and
1730 global variables, collect trace state variables, and define
1731 tracepoint conditions. In addition, the user can collect extra
1732 static tracepoint marker specific data, by collecting the new
1733 $_sdata internal variable. When analyzing the trace buffer, you can
1734 inspect $_sdata like any other variable available to GDB. For more
1735 information, see the "Tracepoints" chapter in GDB user manual. New
1736 remote packets have been defined to support static tracepoints, see
1737 the "New remote packets" section below.
1739 * Better reconstruction of tracepoints after disconnected tracing
1741 GDB will attempt to download the original source form of tracepoint
1742 definitions when starting a trace run, and then will upload these
1743 upon reconnection to the target, resulting in a more accurate
1744 reconstruction of the tracepoints that are in use on the target.
1748 You can now exercise direct control over the ways that GDB can
1749 affect your program. For instance, you can disallow the setting of
1750 breakpoints, so that the program can run continuously (assuming
1751 non-stop mode). In addition, the "observer" variable is available
1752 to switch all of the different controls; in observer mode, GDB
1753 cannot affect the target's behavior at all, which is useful for
1754 tasks like diagnosing live systems in the field.
1756 * The new convenience variable $_thread holds the number of the
1759 * New remote packets
1763 Return the address of the Windows Thread Information Block of a given thread.
1767 In response to several of the tracepoint packets, the target may now
1768 also respond with a number of intermediate `qRelocInsn' request
1769 packets before the final result packet, to have GDB handle
1770 relocating an instruction to execute at a different address. This
1771 is particularly useful for stubs that support fast tracepoints. GDB
1772 reports support for this feature in the qSupported packet.
1776 List static tracepoint markers in the target program.
1780 List static tracepoint markers at a given address in the target
1783 qXfer:statictrace:read
1785 Read the static trace data collected (by a `collect $_sdata'
1786 tracepoint action). The remote stub reports support for this packet
1787 to gdb's qSupported query.
1791 Send the current settings of GDB's permission flags.
1795 Send part of the source (textual) form of a tracepoint definition,
1796 which includes location, conditional, and action list.
1798 * The source command now accepts a -s option to force searching for the
1799 script in the source search path even if the script name specifies
1802 * New features in the GDB remote stub, GDBserver
1804 - GDBserver now support tracepoints (including fast tracepoints, and
1805 static tracepoints). The feature is currently supported by the
1806 i386-linux and amd64-linux builds. See the "Tracepoints support
1807 in gdbserver" section in the manual for more information.
1809 GDBserver JIT compiles the tracepoint's conditional agent
1810 expression bytecode into native code whenever possible for low
1811 overhead dynamic tracepoints conditionals. For such tracepoints,
1812 an expression that examines program state is evaluated when the
1813 tracepoint is reached, in order to determine whether to capture
1814 trace data. If the condition is simple and false, processing the
1815 tracepoint finishes very quickly and no data is gathered.
1817 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1818 for static tracepoints support.
1820 - GDBserver now supports x86_64 Windows 64-bit debugging.
1822 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1823 it understands register description.
1825 * The --batch flag now disables pagination and queries.
1827 * X86 general purpose registers
1829 GDB now supports reading/writing byte, word and double-word x86
1830 general purpose registers directly. This means you can use, say,
1831 $ah or $ax to refer, respectively, to the byte register AH and
1832 16-bit word register AX that are actually portions of the 32-bit
1833 register EAX or 64-bit register RAX.
1835 * The `commands' command now accepts a range of breakpoints to modify.
1836 A plain `commands' following a command that creates multiple
1837 breakpoints affects all the breakpoints set by that command. This
1838 applies to breakpoints set by `rbreak', and also applies when a
1839 single `break' command creates multiple breakpoints (e.g.,
1840 breakpoints on overloaded c++ functions).
1842 * The `rbreak' command now accepts a filename specification as part of
1843 its argument, limiting the functions selected by the regex to those
1844 in the specified file.
1846 * Support for remote debugging Windows and SymbianOS shared libraries
1847 from Unix hosts has been improved. Non Windows GDB builds now can
1848 understand target reported file names that follow MS-DOS based file
1849 system semantics, such as file names that include drive letters and
1850 use the backslash character as directory separator. This makes it
1851 possible to transparently use the "set sysroot" and "set
1852 solib-search-path" on Unix hosts to point as host copies of the
1853 target's shared libraries. See the new command "set
1854 target-file-system-kind" described below, and the "Commands to
1855 specify files" section in the user manual for more information.
1859 eval template, expressions...
1860 Convert the values of one or more expressions under the control
1861 of the string template to a command line, and call it.
1863 set target-file-system-kind unix|dos-based|auto
1864 show target-file-system-kind
1865 Set or show the assumed file system kind for target reported file
1868 save breakpoints <filename>
1869 Save all current breakpoint definitions to a file suitable for use
1870 in a later debugging session. To read the saved breakpoint
1871 definitions, use the `source' command.
1873 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1876 info static-tracepoint-markers
1877 Display information about static tracepoint markers in the target.
1879 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1880 Define a static tracepoint by probing a marker at the given
1881 function, line, address, or marker ID.
1885 Enable and disable observer mode.
1887 set may-write-registers on|off
1888 set may-write-memory on|off
1889 set may-insert-breakpoints on|off
1890 set may-insert-tracepoints on|off
1891 set may-insert-fast-tracepoints on|off
1892 set may-interrupt on|off
1893 Set individual permissions for GDB effects on the target. Note that
1894 some of these settings can have undesirable or surprising
1895 consequences, particularly when changed in the middle of a session.
1896 For instance, disabling the writing of memory can prevent
1897 breakpoints from being inserted, cause single-stepping to fail, or
1898 even crash your program, if you disable after breakpoints have been
1899 inserted. However, GDB should not crash.
1901 set record memory-query on|off
1902 show record memory-query
1903 Control whether to stop the inferior if memory changes caused
1904 by an instruction cannot be recorded.
1909 The disassemble command now supports "start,+length" form of two arguments.
1913 ** GDB now provides a new directory location, called the python directory,
1914 where Python scripts written for GDB can be installed. The location
1915 of that directory is <data-directory>/python, where <data-directory>
1916 is the GDB data directory. For more details, see section `Scripting
1917 GDB using Python' in the manual.
1919 ** The GDB Python API now has access to breakpoints, symbols, symbol
1920 tables, program spaces, inferiors, threads and frame's code blocks.
1921 Additionally, GDB Parameters can now be created from the API, and
1922 manipulated via set/show in the CLI.
1924 ** New functions gdb.target_charset, gdb.target_wide_charset,
1925 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1927 ** New exception gdb.GdbError.
1929 ** Pretty-printers are now also looked up in the current program space.
1931 ** Pretty-printers can now be individually enabled and disabled.
1933 ** GDB now looks for names of Python scripts to auto-load in a
1934 special section named `.debug_gdb_scripts', in addition to looking
1935 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1937 * Tracepoint actions were unified with breakpoint commands. In particular,
1938 there are no longer differences in "info break" output for breakpoints and
1939 tracepoints and the "commands" command can be used for both tracepoints and
1940 regular breakpoints.
1944 ARM Symbian arm*-*-symbianelf*
1946 * D language support.
1947 GDB now supports debugging programs written in the D programming
1950 * GDB now supports the extended ptrace interface for PowerPC which is
1951 available since Linux kernel version 2.6.34. This automatically enables
1952 any hardware breakpoints and additional hardware watchpoints available in
1953 the processor. The old ptrace interface exposes just one hardware
1954 watchpoint and no hardware breakpoints.
1956 * GDB is now able to use the Data Value Compare (DVC) register available on
1957 embedded PowerPC processors to implement in hardware simple watchpoint
1958 conditions of the form:
1960 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1962 This works in native GDB running on Linux kernels with the extended ptrace
1963 interface mentioned above.
1965 *** Changes in GDB 7.1
1969 ** Namespace Support
1971 GDB now supports importing of namespaces in C++. This enables the
1972 user to inspect variables from imported namespaces. Support for
1973 namepace aliasing has also been added. So, if a namespace is
1974 aliased in the current scope (e.g. namepace C=A; ) the user can
1975 print variables using the alias (e.g. (gdb) print C::x).
1979 All known bugs relating to the printing of virtual base class were
1980 fixed. It is now possible to call overloaded static methods using a
1985 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1986 and reinterpret_cast<> are now handled by the C++ expression parser.
1990 Xilinx MicroBlaze microblaze-*-*
1995 Xilinx MicroBlaze microblaze
1998 * Multi-program debugging.
2000 GDB now has support for multi-program (a.k.a. multi-executable or
2001 multi-exec) debugging. This allows for debugging multiple inferiors
2002 simultaneously each running a different program under the same GDB
2003 session. See "Debugging Multiple Inferiors and Programs" in the
2004 manual for more information. This implied some user visible changes
2005 in the multi-inferior support. For example, "info inferiors" now
2006 lists inferiors that are not running yet or that have exited
2007 already. See also "New commands" and "New options" below.
2009 * New tracing features
2011 GDB's tracepoint facility now includes several new features:
2013 ** Trace state variables
2015 GDB tracepoints now include support for trace state variables, which
2016 are variables managed by the target agent during a tracing
2017 experiment. They are useful for tracepoints that trigger each
2018 other, so for instance one tracepoint can count hits in a variable,
2019 and then a second tracepoint has a condition that is true when the
2020 count reaches a particular value. Trace state variables share the
2021 $-syntax of GDB convenience variables, and can appear in both
2022 tracepoint actions and condition expressions. Use the "tvariable"
2023 command to create, and "info tvariables" to view; see "Trace State
2024 Variables" in the manual for more detail.
2028 GDB now includes an option for defining fast tracepoints, which
2029 targets may implement more efficiently, such as by installing a jump
2030 into the target agent rather than a trap instruction. The resulting
2031 speedup can be by two orders of magnitude or more, although the
2032 tradeoff is that some program locations on some target architectures
2033 might not allow fast tracepoint installation, for instance if the
2034 instruction to be replaced is shorter than the jump. To request a
2035 fast tracepoint, use the "ftrace" command, with syntax identical to
2036 the regular trace command.
2038 ** Disconnected tracing
2040 It is now possible to detach GDB from the target while it is running
2041 a trace experiment, then reconnect later to see how the experiment
2042 is going. In addition, a new variable disconnected-tracing lets you
2043 tell the target agent whether to continue running a trace if the
2044 connection is lost unexpectedly.
2048 GDB now has the ability to save the trace buffer into a file, and
2049 then use that file as a target, similarly to you can do with
2050 corefiles. You can select trace frames, print data that was
2051 collected in them, and use tstatus to display the state of the
2052 tracing run at the moment that it was saved. To create a trace
2053 file, use "tsave <filename>", and to use it, do "target tfile
2056 ** Circular trace buffer
2058 You can ask the target agent to handle the trace buffer as a
2059 circular buffer, discarding the oldest trace frames to make room for
2060 newer ones, by setting circular-trace-buffer to on. This feature may
2061 not be available for all target agents.
2066 The disassemble command, when invoked with two arguments, now requires
2067 the arguments to be comma-separated.
2070 The info variables command now displays variable definitions. Files
2071 which only declare a variable are not shown.
2074 The source command is now capable of sourcing Python scripts.
2075 This feature is dependent on the debugger being build with Python
2078 Related to this enhancement is also the introduction of a new command
2079 "set script-extension" (see below).
2081 * New commands (for set/show, see "New options" below)
2083 record save [<FILENAME>]
2084 Save a file (in core file format) containing the process record
2085 execution log for replay debugging at a later time.
2087 record restore <FILENAME>
2088 Restore the process record execution log that was saved at an
2089 earlier time, for replay debugging.
2091 add-inferior [-copies <N>] [-exec <FILENAME>]
2094 clone-inferior [-copies <N>] [ID]
2095 Make a new inferior ready to execute the same program another
2096 inferior has loaded.
2101 maint info program-spaces
2102 List the program spaces loaded into GDB.
2104 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2105 show remote interrupt-sequence
2106 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2107 as the sequence to the remote target in order to interrupt the execution.
2108 Ctrl-C is a default. Some system prefers BREAK which is high level of
2109 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2110 Magic SysRq g. It is BREAK signal and character 'g'.
2112 set remote interrupt-on-connect [on | off]
2113 show remote interrupt-on-connect
2114 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2115 remote target when gdb connects to it. This is needed when you debug
2118 set remotebreak [on | off]
2120 Deprecated. Use "set/show remote interrupt-sequence" instead.
2122 tvariable $NAME [ = EXP ]
2123 Create or modify a trace state variable.
2126 List trace state variables and their values.
2128 delete tvariable $NAME ...
2129 Delete one or more trace state variables.
2132 Evaluate the given expressions without collecting anything into the
2133 trace buffer. (Valid in tracepoint actions only.)
2135 ftrace FN / FILE:LINE / *ADDR
2136 Define a fast tracepoint at the given function, line, or address.
2138 * New expression syntax
2140 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2141 GDB now parses 0b101010 identically with 42.
2145 set follow-exec-mode new|same
2146 show follow-exec-mode
2147 Control whether GDB reuses the same inferior across an exec call or
2148 creates a new one. This is useful to be able to restart the old
2149 executable after the inferior having done an exec call.
2151 set default-collect EXPR, ...
2152 show default-collect
2153 Define a list of expressions to be collected at each tracepoint.
2154 This is a useful way to ensure essential items are not overlooked,
2155 such as registers or a critical global variable.
2157 set disconnected-tracing
2158 show disconnected-tracing
2159 If set to 1, the target is instructed to continue tracing if it
2160 loses its connection to GDB. If 0, the target is to stop tracing
2163 set circular-trace-buffer
2164 show circular-trace-buffer
2165 If set to on, the target is instructed to use a circular trace buffer
2166 and discard the oldest trace frames instead of stopping the trace due
2167 to a full trace buffer. If set to off, the trace stops when the buffer
2168 fills up. Some targets may not support this.
2170 set script-extension off|soft|strict
2171 show script-extension
2172 If set to "off", the debugger does not perform any script language
2173 recognition, and all sourced files are assumed to be GDB scripts.
2174 If set to "soft" (the default), files are sourced according to
2175 filename extension, falling back to GDB scripts if the first
2177 If set to "strict", files are sourced according to filename extension.
2179 set ada trust-PAD-over-XVS on|off
2180 show ada trust-PAD-over-XVS
2181 If off, activate a workaround against a bug in the debugging information
2182 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2183 the GCC sources for more information about the GNAT encoding and
2184 PAD types in particular). It is always safe to set this option to
2185 off, but this introduces a slight performance penalty. The default
2188 * Python API Improvements
2190 ** GDB provides the new class gdb.LazyString. This is useful in
2191 some pretty-printing cases. The new method gdb.Value.lazy_string
2192 provides a simple way to create objects of this type.
2194 ** The fields returned by gdb.Type.fields now have an
2195 `is_base_class' attribute.
2197 ** The new method gdb.Type.range returns the range of an array type.
2199 ** The new method gdb.parse_and_eval can be used to parse and
2200 evaluate an expression.
2202 * New remote packets
2205 Define a trace state variable.
2208 Get the current value of a trace state variable.
2211 Set desired tracing behavior upon disconnection.
2214 Set the trace buffer to be linear or circular.
2217 Get data about the tracepoints currently in use.
2221 Process record now works correctly with hardware watchpoints.
2223 Multiple bug fixes have been made to the mips-irix port, making it
2224 much more reliable. In particular:
2225 - Debugging threaded applications is now possible again. Previously,
2226 GDB would hang while starting the program, or while waiting for
2227 the program to stop at a breakpoint.
2228 - Attaching to a running process no longer hangs.
2229 - An error occurring while loading a core file has been fixed.
2230 - Changing the value of the PC register now works again. This fixes
2231 problems observed when using the "jump" command, or when calling
2232 a function from GDB, or even when assigning a new value to $pc.
2233 - With the "finish" and "return" commands, the return value for functions
2234 returning a small array is now correctly printed.
2235 - It is now possible to break on shared library code which gets executed
2236 during a shared library init phase (code executed while executing
2237 their .init section). Previously, the breakpoint would have no effect.
2238 - GDB is now able to backtrace through the signal handler for
2239 non-threaded programs.
2241 PIE (Position Independent Executable) programs debugging is now supported.
2242 This includes debugging execution of PIC (Position Independent Code) shared
2243 libraries although for that, it should be possible to run such libraries as an
2246 *** Changes in GDB 7.0
2248 * GDB now has an interface for JIT compilation. Applications that
2249 dynamically generate code can create symbol files in memory and register
2250 them with GDB. For users, the feature should work transparently, and
2251 for JIT developers, the interface is documented in the GDB manual in the
2252 "JIT Compilation Interface" chapter.
2254 * Tracepoints may now be conditional. The syntax is as for
2255 breakpoints; either an "if" clause appended to the "trace" command,
2256 or the "condition" command is available. GDB sends the condition to
2257 the target for evaluation using the same bytecode format as is used
2258 for tracepoint actions.
2260 * The disassemble command now supports: an optional /r modifier, print the
2261 raw instructions in hex as well as in symbolic form, and an optional /m
2262 modifier to print mixed source+assembly.
2264 * Process record and replay
2266 In a architecture environment that supports ``process record and
2267 replay'', ``process record and replay'' target can record a log of
2268 the process execution, and replay it with both forward and reverse
2271 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2272 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2273 set execution-direction {forward|reverse}, for targets that support
2276 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2277 feature is available with a native GDB running on kernel version
2280 * GDB now has support for multi-byte and wide character sets on the
2281 target. Strings whose character type is wchar_t, char16_t, or
2282 char32_t are now correctly printed. GDB supports wide- and unicode-
2283 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2284 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2285 `printf'. This feature requires iconv to work properly; if your
2286 system does not have a working iconv, GDB can use GNU libiconv. See
2287 the installation instructions for more information.
2289 * GDB now supports automatic retrieval of shared library files from
2290 remote targets. To use this feature, specify a system root that begins
2291 with the `remote:' prefix, either via the `set sysroot' command or via
2292 the `--with-sysroot' configure-time option.
2294 * "info sharedlibrary" now takes an optional regex of libraries to show,
2295 and it now reports if a shared library has no debugging information.
2297 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2298 now complete on file names.
2300 * When completing in expressions, gdb will attempt to limit
2301 completions to allowable structure or union fields, where appropriate.
2302 For instance, consider:
2304 # struct example { int f1; double f2; };
2305 # struct example variable;
2308 If the user types TAB at the end of this command line, the available
2309 completions will be "f1" and "f2".
2311 * Inlined functions are now supported. They show up in backtraces, and
2312 the "step", "next", and "finish" commands handle them automatically.
2314 * GDB now supports the token-splicing (##) and stringification (#)
2315 operators when expanding macros. It also supports variable-arity
2318 * GDB now supports inspecting extra signal information, exported by
2319 the new $_siginfo convenience variable. The feature is currently
2320 implemented on linux ARM, i386 and amd64.
2322 * GDB can now display the VFP floating point registers and NEON vector
2323 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2324 can provide these registers (requires Linux 2.6.30 or later). Remote
2325 and simulator targets may also provide them.
2327 * New remote packets
2330 Search memory for a sequence of bytes.
2333 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2334 operation over reliable transport links. Use of this packet is
2335 controlled by the `set remote noack-packet' command.
2338 Kill the process with the specified process ID. Use this in preference
2339 to `k' when multiprocess protocol extensions are supported.
2342 Obtains additional operating system information
2346 Read or write additional signal information.
2348 * Removed remote protocol undocumented extension
2350 An undocumented extension to the remote protocol's `S' stop reply
2351 packet that permited the stub to pass a process id was removed.
2352 Remote servers should use the `T' stop reply packet instead.
2354 * GDB now supports multiple function calling conventions according to the
2355 DWARF-2 DW_AT_calling_convention function attribute.
2357 * The SH target utilizes the aforementioned change to distinguish between gcc
2358 and Renesas calling convention. It also adds the new CLI commands
2359 `set/show sh calling-convention'.
2361 * GDB can now read compressed debug sections, as produced by GNU gold
2362 with the --compress-debug-sections=zlib flag.
2364 * 64-bit core files are now supported on AIX.
2366 * Thread switching is now supported on Tru64.
2368 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2369 which will be allocated using malloc later in program execution.
2371 * The qXfer:libraries:read remote procotol packet now allows passing a
2372 list of section offsets.
2374 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2375 conditions handling signals delivered during attach or thread creation
2376 have also been fixed.
2378 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2379 From the user's standpoint, all unqualified instances of True and False
2380 are treated as the standard definitions, regardless of context.
2382 * GDB now parses C++ symbol and type names more flexibly. For
2385 template<typename T> class C { };
2388 GDB will now correctly handle all of:
2390 ptype C<char const *>
2391 ptype C<char const*>
2392 ptype C<const char *>
2393 ptype C<const char*>
2395 * New features in the GDB remote stub, gdbserver
2397 - The "--wrapper" command-line argument tells gdbserver to use a
2398 wrapper program to launch programs for debugging.
2400 - On PowerPC and S/390 targets, it is now possible to use a single
2401 gdbserver executable to debug both 32-bit and 64-bit programs.
2402 (This requires gdbserver itself to be built as a 64-bit executable.)
2404 - gdbserver uses the new noack protocol mode for TCP connections to
2405 reduce communications latency, if also supported and enabled in GDB.
2407 - Support for the sparc64-linux-gnu target is now included in
2410 - The amd64-linux build of gdbserver now supports debugging both
2411 32-bit and 64-bit programs.
2413 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2414 now support hardware watchpoints, and will use them automatically
2419 GDB now has support for scripting using Python. Whether this is
2420 available is determined at configure time.
2422 New GDB commands can now be written in Python.
2424 * Ada tasking support
2426 Ada tasks can now be inspected in GDB. The following commands have
2430 Print the list of Ada tasks.
2432 Print detailed information about task number N.
2434 Print the task number of the current task.
2436 Switch the context of debugging to task number N.
2438 * Support for user-defined prefixed commands. The "define" command can
2439 add new commands to existing prefixes, e.g. "target".
2441 * Multi-inferior, multi-process debugging.
2443 GDB now has generalized support for multi-inferior debugging. See
2444 "Debugging Multiple Inferiors" in the manual for more information.
2445 Although availability still depends on target support, the command
2446 set is more uniform now. The GNU/Linux specific multi-forks support
2447 has been migrated to this new framework. This implied some user
2448 visible changes; see "New commands" and also "Removed commands"
2451 * Target descriptions can now describe the target OS ABI. See the
2452 "Target Description Format" section in the user manual for more
2455 * Target descriptions can now describe "compatible" architectures
2456 to indicate that the target can execute applications for a different
2457 architecture in addition to those for the main target architecture.
2458 See the "Target Description Format" section in the user manual for
2461 * Multi-architecture debugging.
2463 GDB now includes general supports for debugging applications on
2464 hybrid systems that use more than one single processor architecture
2465 at the same time. Each such hybrid architecture still requires
2466 specific support to be added. The only hybrid architecture supported
2467 in this version of GDB is the Cell Broadband Engine.
2469 * GDB now supports integrated debugging of Cell/B.E. applications that
2470 use both the PPU and SPU architectures. To enable support for hybrid
2471 Cell/B.E. debugging, you need to configure GDB to support both the
2472 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2473 --enable-targets configure option.
2475 * Non-stop mode debugging.
2477 For some targets, GDB now supports an optional mode of operation in
2478 which you can examine stopped threads while other threads continue
2479 to execute freely. This is referred to as non-stop mode, with the
2480 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2481 section in the user manual for more information.
2483 To be able to support remote non-stop debugging, a remote stub needs
2484 to implement the non-stop mode remote protocol extensions, as
2485 described in the "Remote Non-Stop" section of the user manual. The
2486 GDB remote stub, gdbserver, has been adjusted to support these
2487 extensions on linux targets.
2489 * New commands (for set/show, see "New options" below)
2491 catch syscall [NAME(S) | NUMBER(S)]
2492 Catch system calls. Arguments, which should be names of system
2493 calls or their numbers, mean catch only those syscalls. Without
2494 arguments, every syscall will be caught. When the inferior issues
2495 any of the specified syscalls, GDB will stop and announce the system
2496 call, both when it is called and when its call returns. This
2497 feature is currently available with a native GDB running on the
2498 Linux Kernel, under the following architectures: x86, x86_64,
2499 PowerPC and PowerPC64.
2501 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2503 Search memory for a sequence of bytes.
2505 maint set python print-stack
2506 maint show python print-stack
2507 Show a stack trace when an error is encountered in a Python script.
2510 Invoke CODE by passing it to the Python interpreter.
2515 These allow macros to be defined, undefined, and listed
2519 Show operating system information about processes.
2522 List the inferiors currently under GDB's control.
2525 Switch focus to inferior number NUM.
2528 Detach from inferior number NUM.
2531 Kill inferior number NUM.
2535 set spu stop-on-load
2536 show spu stop-on-load
2537 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2539 set spu auto-flush-cache
2540 show spu auto-flush-cache
2541 Control whether to automatically flush the software-managed cache
2542 during Cell/B.E. debugging.
2544 set sh calling-convention
2545 show sh calling-convention
2546 Control the calling convention used when calling SH target functions.
2549 show debug timestamp
2550 Control display of timestamps with GDB debugging output.
2552 set disassemble-next-line
2553 show disassemble-next-line
2554 Control display of disassembled source lines or instructions when
2557 set remote noack-packet
2558 show remote noack-packet
2559 Set/show the use of remote protocol QStartNoAckMode packet. See above
2560 under "New remote packets."
2562 set remote query-attached-packet
2563 show remote query-attached-packet
2564 Control use of remote protocol `qAttached' (query-attached) packet.
2566 set remote read-siginfo-object
2567 show remote read-siginfo-object
2568 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2571 set remote write-siginfo-object
2572 show remote write-siginfo-object
2573 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2576 set remote reverse-continue
2577 show remote reverse-continue
2578 Control use of remote protocol 'bc' (reverse-continue) packet.
2580 set remote reverse-step
2581 show remote reverse-step
2582 Control use of remote protocol 'bs' (reverse-step) packet.
2584 set displaced-stepping
2585 show displaced-stepping
2586 Control displaced stepping mode. Displaced stepping is a way to
2587 single-step over breakpoints without removing them from the debuggee.
2588 Also known as "out-of-line single-stepping".
2591 show debug displaced
2592 Control display of debugging info for displaced stepping.
2594 maint set internal-error
2595 maint show internal-error
2596 Control what GDB does when an internal error is detected.
2598 maint set internal-warning
2599 maint show internal-warning
2600 Control what GDB does when an internal warning is detected.
2605 Use a wrapper program to launch programs for debugging.
2607 set multiple-symbols (all|ask|cancel)
2608 show multiple-symbols
2609 The value of this variable can be changed to adjust the debugger behavior
2610 when an expression or a breakpoint location contains an ambiguous symbol
2611 name (an overloaded function name, for instance).
2613 set breakpoint always-inserted
2614 show breakpoint always-inserted
2615 Keep breakpoints always inserted in the target, as opposed to inserting
2616 them when resuming the target, and removing them when the target stops.
2617 This option can improve debugger performance on slow remote targets.
2619 set arm fallback-mode (arm|thumb|auto)
2620 show arm fallback-mode
2621 set arm force-mode (arm|thumb|auto)
2623 These commands control how ARM GDB determines whether instructions
2624 are ARM or Thumb. The default for both settings is auto, which uses
2625 the current CPSR value for instructions without symbols; previous
2626 versions of GDB behaved as if "set arm fallback-mode arm".
2628 set disable-randomization
2629 show disable-randomization
2630 Standalone programs run with the virtual address space randomization enabled
2631 by default on some platforms. This option keeps the addresses stable across
2632 multiple debugging sessions.
2636 Control whether other threads are stopped or not when some thread hits
2641 Requests that asynchronous execution is enabled in the target, if available.
2642 In this case, it's possible to resume target in the background, and interact
2643 with GDB while the target is running. "show target-async" displays the
2644 current state of asynchronous execution of the target.
2646 set target-wide-charset
2647 show target-wide-charset
2648 The target-wide-charset is the name of the character set that GDB
2649 uses when printing characters whose type is wchar_t.
2651 set tcp auto-retry (on|off)
2653 set tcp connect-timeout
2654 show tcp connect-timeout
2655 These commands allow GDB to retry failed TCP connections to a remote stub
2656 with a specified timeout period; this is useful if the stub is launched
2657 in parallel with GDB but may not be ready to accept connections immediately.
2659 set libthread-db-search-path
2660 show libthread-db-search-path
2661 Control list of directories which GDB will search for appropriate
2664 set schedule-multiple (on|off)
2665 show schedule-multiple
2666 Allow GDB to resume all threads of all processes or only threads of
2667 the current process.
2671 Use more aggressive caching for accesses to the stack. This improves
2672 performance of remote debugging (particularly backtraces) without
2673 affecting correctness.
2675 set interactive-mode (on|off|auto)
2676 show interactive-mode
2677 Control whether GDB runs in interactive mode (on) or not (off).
2678 When in interactive mode, GDB waits for the user to answer all
2679 queries. Otherwise, GDB does not wait and assumes the default
2680 answer. When set to auto (the default), GDB determines which
2681 mode to use based on the stdin settings.
2686 For program forks, this is replaced by the new more generic `info
2687 inferiors' command. To list checkpoints, you can still use the
2688 `info checkpoints' command, which was an alias for the `info forks'
2692 Replaced by the new `inferior' command. To switch between
2693 checkpoints, you can still use the `restart' command, which was an
2694 alias for the `fork' command.
2697 This is removed, since some targets don't have a notion of
2698 processes. To switch between processes, you can still use the
2699 `inferior' command using GDB's own inferior number.
2702 For program forks, this is replaced by the new more generic `kill
2703 inferior' command. To delete a checkpoint, you can still use the
2704 `delete checkpoint' command, which was an alias for the `delete
2708 For program forks, this is replaced by the new more generic `detach
2709 inferior' command. To detach a checkpoint, you can still use the
2710 `detach checkpoint' command, which was an alias for the `detach
2713 * New native configurations
2715 x86/x86_64 Darwin i[34567]86-*-darwin*
2717 x86_64 MinGW x86_64-*-mingw*
2721 Lattice Mico32 lm32-*
2722 x86 DICOS i[34567]86-*-dicos*
2723 x86_64 DICOS x86_64-*-dicos*
2726 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2727 (mingw32ce) debugging.
2733 These commands were actually not implemented on any target.
2735 *** Changes in GDB 6.8
2737 * New native configurations
2739 NetBSD/hppa hppa*-*netbsd*
2740 Xtensa GNU/Linux xtensa*-*-linux*
2744 NetBSD/hppa hppa*-*-netbsd*
2745 Xtensa GNU/Lunux xtensa*-*-linux*
2747 * Change in command line behavior -- corefiles vs. process ids.
2749 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2750 attaching to process NUMBER fails, GDB no longer attempts to open a
2751 core file named NUMBER. Attaching to a program using the -c option
2752 is no longer supported. Instead, use the '-p' or '--pid' options.
2754 * GDB can now be built as a native debugger for debugging Windows x86
2755 (mingw32) Portable Executable (PE) programs.
2757 * Pending breakpoints no longer change their number when their address
2760 * GDB now supports breakpoints with multiple locations,
2761 including breakpoints on C++ constructors, inside C++ templates,
2762 and in inlined functions.
2764 * GDB's ability to debug optimized code has been improved. GDB more
2765 accurately identifies function bodies and lexical blocks that occupy
2766 more than one contiguous range of addresses.
2768 * Target descriptions can now describe registers for PowerPC.
2770 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2771 registers on PowerPC targets.
2773 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2774 targets even when the libthread_db library is not available.
2776 * The GDB remote stub, gdbserver, now supports the new file transfer
2777 commands (remote put, remote get, and remote delete).
2779 * The GDB remote stub, gdbserver, now supports run and attach in
2780 extended-remote mode.
2782 * hppa*64*-*-hpux11* target broken
2783 The debugger is unable to start a program and fails with the following
2784 error: "Error trying to get information about dynamic linker".
2785 The gdb-6.7 release is also affected.
2787 * GDB now supports the --enable-targets= configure option to allow
2788 building a single GDB executable that supports multiple remote
2789 target architectures.
2791 * GDB now supports debugging C and C++ programs which use the
2792 Decimal Floating Point extension. In addition, the PowerPC target
2793 now has a set of pseudo-registers to inspect decimal float values
2794 stored in two consecutive float registers.
2796 * The -break-insert MI command can optionally create pending
2799 * Improved support for debugging Ada
2800 Many improvements to the Ada language support have been made. These
2802 - Better support for Ada2005 interface types
2803 - Improved handling of arrays and slices in general
2804 - Better support for Taft-amendment types
2805 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2807 - Improved command completion in Ada
2810 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2815 set print frame-arguments (all|scalars|none)
2816 show print frame-arguments
2817 The value of this variable can be changed to control which argument
2818 values should be printed by the debugger when displaying a frame.
2823 Transfer files to and from a remote target, and delete remote files.
2830 Transfer files to and from a remote target, and delete remote files.
2832 * New remote packets
2839 Open, close, read, write, and delete files on the remote system.
2842 Attach to an existing process on the remote system, in extended-remote
2846 Run a new process on the remote system, in extended-remote mode.
2848 *** Changes in GDB 6.7
2850 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2851 bfd, libiberty and opcodes, as revealed by static analysis donated by
2852 Coverity, Inc. (http://scan.coverity.com).
2854 * When looking up multiply-defined global symbols, GDB will now prefer the
2855 symbol definition in the current shared library if it was built using the
2856 -Bsymbolic linker option.
2858 * When the Text User Interface (TUI) is not configured, GDB will now
2859 recognize the -tui command-line option and print a message that the TUI
2862 * The GDB remote stub, gdbserver, now has lower overhead for high
2863 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2865 * GDB for MIPS targets now autodetects whether a remote target provides
2866 32-bit or 64-bit register values.
2868 * Support for C++ member pointers has been improved.
2870 * GDB now understands XML target descriptions, which specify the
2871 target's overall architecture. GDB can read a description from
2872 a local file or over the remote serial protocol.
2874 * Vectors of single-byte data use a new integer type which is not
2875 automatically displayed as character or string data.
2877 * The /s format now works with the print command. It displays
2878 arrays of single-byte integers and pointers to single-byte integers
2881 * Target descriptions can now describe target-specific registers,
2882 for architectures which have implemented the support (currently
2883 only ARM, M68K, and MIPS).
2885 * GDB and the GDB remote stub, gdbserver, now support the XScale
2888 * The GDB remote stub, gdbserver, has been updated to support
2889 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2890 has been rewritten to use the standard GDB remote protocol.
2892 * GDB can now step into C++ functions which are called through thunks.
2894 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2896 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2897 layout. It also supports a TextSeg= and DataSeg= response when only
2898 segment base addresses (rather than offsets) are available.
2900 * The /i format now outputs any trailing branch delay slot instructions
2901 immediately following the last instruction within the count specified.
2903 * The GDB remote protocol "T" stop reply packet now supports a
2904 "library" response. Combined with the new "qXfer:libraries:read"
2905 packet, this response allows GDB to debug shared libraries on targets
2906 where the operating system manages the list of loaded libraries (e.g.
2907 Windows and SymbianOS).
2909 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2910 (DLLs) on Windows and Windows CE targets.
2912 * GDB now supports a faster verification that a .debug file matches its binary
2913 according to its build-id signature, if the signature is present.
2919 Enable or disable hardware flow control (RTS/CTS) on the serial port
2920 when debugging using remote targets.
2922 set mem inaccessible-by-default
2923 show mem inaccessible-by-default
2924 If the target supplies a memory map, for instance via the remote
2925 protocol's "qXfer:memory-map:read" packet, setting this variable
2926 prevents GDB from accessing memory outside the memory map. This
2927 is useful for targets with memory mapped registers or which react
2928 badly to accesses of unmapped address space.
2930 set breakpoint auto-hw
2931 show breakpoint auto-hw
2932 If the target supplies a memory map, for instance via the remote
2933 protocol's "qXfer:memory-map:read" packet, setting this variable
2934 lets GDB use hardware breakpoints automatically for memory regions
2935 where it can not use software breakpoints. This covers both the
2936 "break" command and internal breakpoints used for other commands
2937 including "next" and "finish".
2940 catch exception unhandled
2941 Stop the program execution when Ada exceptions are raised.
2944 Stop the program execution when an Ada assertion failed.
2948 Set an alternate system root for target files. This is a more
2949 general version of "set solib-absolute-prefix", which is now
2950 an alias to "set sysroot".
2953 Provide extended SPU facility status information. This set of
2954 commands is available only when debugging the Cell/B.E. SPU
2957 * New native configurations
2959 OpenBSD/sh sh*-*openbsd*
2962 unset tdesc filename
2964 Use the specified local file as an XML target description, and do
2965 not query the target for its built-in description.
2969 OpenBSD/sh sh*-*-openbsd*
2970 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2971 Toshiba Media Processor mep-elf
2973 * New remote packets
2976 Ignore the specified signals; pass them directly to the debugged program
2977 without stopping other threads or reporting them to GDB.
2979 qXfer:features:read:
2980 Read an XML target description from the target, which describes its
2985 Read or write contents of an spufs file on the target system. These
2986 packets are available only on the Cell/B.E. SPU architecture.
2988 qXfer:libraries:read:
2989 Report the loaded shared libraries. Combined with new "T" packet
2990 response, this packet allows GDB to debug shared libraries on
2991 targets where the operating system manages the list of loaded
2992 libraries (e.g. Windows and SymbianOS).
2996 Support for these obsolete configurations has been removed.
3004 i[34567]86-*-lynxos*
3005 i[34567]86-*-netware*
3006 i[34567]86-*-sco3.2v5*
3007 i[34567]86-*-sco3.2v4*
3009 i[34567]86-*-sysv4.2*
3012 i[34567]86-*-unixware2*
3013 i[34567]86-*-unixware*
3022 * Other removed features
3029 Various m68k-only ROM monitors.
3036 Various Renesas ROM monitors and debugging interfaces for SH and
3041 Support for a Macraigor serial interface to on-chip debugging.
3042 GDB does not directly support the newer parallel or USB
3047 A debug information format. The predecessor to DWARF 2 and
3048 DWARF 3, which are still supported.
3050 Support for the HP aCC compiler on HP-UX/PA-RISC
3052 SOM-encapsulated symbolic debugging information, automatic
3053 invocation of pxdb, and the aCC custom C++ ABI. This does not
3054 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3055 with aCC can still be debugged on an assembly level.
3057 MIPS ".pdr" sections
3059 A MIPS-specific format used to describe stack frame layout
3060 in debugging information.
3064 GDB could work with an older version of Guile to debug
3065 the interpreter and Scheme programs running in it.
3067 set mips stack-arg-size
3068 set mips saved-gpreg-size
3070 Use "set mips abi" to control parameter passing for MIPS.
3072 *** Changes in GDB 6.6
3077 Cell Broadband Engine SPU spu-elf
3079 * GDB can now be configured as a cross-debugger targeting native Windows
3080 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3081 running on a Windows system over TCP/IP to debug Windows programs.
3083 * The GDB remote stub, gdbserver, has been updated to support Windows and
3084 Cygwin debugging. Both single-threaded and multi-threaded programs are
3087 * The "set trust-readonly-sections" command works again. This command was
3088 broken in GDB 6.3, 6.4, and 6.5.
3090 * The "load" command now supports writing to flash memory, if the remote
3091 stub provides the required support.
3093 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3094 longer requires symbolic debug information (e.g. DWARF-2).
3099 unset substitute-path
3100 show substitute-path
3101 Manage a list of substitution rules that GDB uses to rewrite the name
3102 of the directories where the sources are located. This can be useful
3103 for instance when the sources were moved to a different location
3104 between compilation and debugging.
3108 Print each CLI command as it is executed. Each command is prefixed with
3109 a number of `+' symbols representing the nesting depth.
3110 The source command now has a `-v' option to enable the same feature.
3114 The ARM Demon monitor support (RDP protocol, "target rdp").
3116 Kernel Object Display, an embedded debugging feature which only worked with
3117 an obsolete version of Cisco IOS.
3119 The 'set download-write-size' and 'show download-write-size' commands.
3121 * New remote packets
3124 Tell a stub about GDB client features, and request remote target features.
3125 The first feature implemented is PacketSize, which allows the target to
3126 specify the size of packets it can handle - to minimize the number of
3127 packets required and improve performance when connected to a remote
3131 Fetch an OS auxilliary vector from the remote stub. This packet is a
3132 more efficient replacement for qPart:auxv:read.
3134 qXfer:memory-map:read:
3135 Fetch a memory map from the remote stub, including information about
3136 RAM, ROM, and flash memory devices.
3141 Erase and program a flash memory device.
3143 * Removed remote packets
3146 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3147 used it, and only gdbserver implemented it.
3149 *** Changes in GDB 6.5
3153 Renesas M32C/M16C m32c-elf
3155 Morpho Technologies ms1 ms1-elf
3159 init-if-undefined Initialize a convenience variable, but
3160 only if it doesn't already have a value.
3162 The following commands are presently only implemented for native GNU/Linux:
3164 checkpoint Save a snapshot of the program state.
3166 restart <n> Return the program state to a
3167 previously saved state.
3169 info checkpoints List currently saved checkpoints.
3171 delete-checkpoint <n> Delete a previously saved checkpoint.
3173 set|show detach-on-fork Tell gdb whether to detach from a newly
3174 forked process, or to keep debugging it.
3176 info forks List forks of the user program that
3177 are available to be debugged.
3179 fork <n> Switch to debugging one of several
3180 forks of the user program that are
3181 available to be debugged.
3183 delete-fork <n> Delete a fork from the list of forks
3184 that are available to be debugged (and
3185 kill the forked process).
3187 detach-fork <n> Delete a fork from the list of forks
3188 that are available to be debugged (and
3189 allow the process to continue).
3193 Morpho Technologies ms2 ms1-elf
3195 * Improved Windows host support
3197 GDB now builds as a cross debugger hosted on i686-mingw32, including
3198 native console support, and remote communications using either
3199 network sockets or serial ports.
3201 * Improved Modula-2 language support
3203 GDB can now print most types in the Modula-2 syntax. This includes:
3204 basic types, set types, record types, enumerated types, range types,
3205 pointer types and ARRAY types. Procedure var parameters are correctly
3206 printed and hexadecimal addresses and character constants are also
3207 written in the Modula-2 syntax. Best results can be obtained by using
3208 GNU Modula-2 together with the -gdwarf-2 command line option.
3212 The ARM rdi-share module.
3214 The Netware NLM debug server.
3216 *** Changes in GDB 6.4
3218 * New native configurations
3220 OpenBSD/arm arm*-*-openbsd*
3221 OpenBSD/mips64 mips64-*-openbsd*
3225 Morpho Technologies ms1 ms1-elf
3227 * New command line options
3229 --batch-silent As for --batch, but totally silent.
3230 --return-child-result The debugger will exist with the same value
3231 the child (debugged) program exited with.
3232 --eval-command COMMAND, -ex COMMAND
3233 Execute a single GDB CLI command. This may be
3234 specified multiple times and in conjunction
3235 with the --command (-x) option.
3237 * Deprecated commands removed
3239 The following commands, that were deprecated in 2000, have been
3243 set|show arm disassembly-flavor set|show arm disassembler
3244 othernames set arm disassembler
3245 set|show remotedebug set|show debug remote
3246 set|show archdebug set|show debug arch
3247 set|show eventdebug set|show debug event
3250 * New BSD user-level threads support
3252 It is now possible to debug programs using the user-level threads
3253 library on OpenBSD and FreeBSD. Currently supported (target)
3256 FreeBSD/amd64 x86_64-*-freebsd*
3257 FreeBSD/i386 i386-*-freebsd*
3258 OpenBSD/i386 i386-*-openbsd*
3260 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3261 are not yet supported.
3263 * New support for Matsushita MN10300 w/sim added
3264 (Work in progress). mn10300-elf.
3266 * REMOVED configurations and files
3268 VxWorks and the XDR protocol *-*-vxworks
3269 Motorola MCORE mcore-*-*
3270 National Semiconductor NS32000 ns32k-*-*
3272 * New "set print array-indexes" command
3274 After turning this setting "on", GDB prints the index of each element
3275 when displaying arrays. The default is "off" to preserve the previous
3278 * VAX floating point support
3280 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3282 * User-defined command support
3284 In addition to using $arg0..$arg9 for argument passing, it is now possible
3285 to use $argc to determine now many arguments have been passed. See the
3286 section on user-defined commands in the user manual for more information.
3288 *** Changes in GDB 6.3:
3290 * New command line option
3292 GDB now accepts -l followed by a number to set the timeout for remote
3295 * GDB works with GCC -feliminate-dwarf2-dups
3297 GDB now supports a more compact representation of DWARF-2 debug
3298 information using DW_FORM_ref_addr references. These are produced
3299 by GCC with the option -feliminate-dwarf2-dups and also by some
3300 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3301 to use -feliminate-dwarf2-dups.
3303 * Internationalization
3305 When supported by the host system, GDB will be built with
3306 internationalization (libintl). The task of marking up the sources is
3307 continued, we're looking forward to our first translation.
3311 Initial support for debugging programs compiled with the GNAT
3312 implementation of the Ada programming language has been integrated
3313 into GDB. In this release, support is limited to expression evaluation.
3315 * New native configurations
3317 GNU/Linux/m32r m32r-*-linux-gnu
3321 GDB's remote protocol now includes support for the 'p' packet. This
3322 packet is used to fetch individual registers from a remote inferior.
3324 * END-OF-LIFE registers[] compatibility module
3326 GDB's internal register infrastructure has been completely rewritten.
3327 The new infrastructure making possible the implementation of key new
3328 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3331 GDB 6.3 will be the last release to include the the registers[]
3332 compatibility module that allowed out-of-date configurations to
3333 continue to work. This change directly impacts the following
3343 powerpc bdm protocol
3345 Unless there is activity to revive these configurations, they will be
3346 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3348 * OBSOLETE configurations and files
3350 Configurations that have been declared obsolete in this release have
3351 been commented out. Unless there is activity to revive these
3352 configurations, the next release of GDB will have their sources
3353 permanently REMOVED.
3362 *** Changes in GDB 6.2.1:
3364 * MIPS `break main; run' gave an heuristic-fence-post warning
3366 When attempting to run even a simple program, a warning about
3367 heuristic-fence-post being hit would be reported. This problem has
3370 * MIPS IRIX 'long double' crashed GDB
3372 When examining a long double variable, GDB would get a segmentation
3373 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3374 IRIX long double values).
3378 A bug in the VAX stack code was causing problems with the "next"
3379 command. This problem has been fixed.
3381 *** Changes in GDB 6.2:
3383 * Fix for ``many threads''
3385 On GNU/Linux systems that use the NPTL threads library, a program
3386 rapidly creating and deleting threads would confuse GDB leading to the
3389 ptrace: No such process.
3390 thread_db_get_info: cannot get thread info: generic error
3392 This problem has been fixed.
3394 * "-async" and "-noasync" options removed.
3396 Support for the broken "-noasync" option has been removed (it caused
3399 * New ``start'' command.
3401 This command runs the program until the begining of the main procedure.
3403 * New BSD Kernel Data Access Library (libkvm) interface
3405 Using ``target kvm'' it is now possible to debug kernel core dumps and
3406 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3407 platforms. Currently supported (native-only) configurations are:
3409 FreeBSD/amd64 x86_64-*-freebsd*
3410 FreeBSD/i386 i?86-*-freebsd*
3411 NetBSD/i386 i?86-*-netbsd*
3412 NetBSD/m68k m68*-*-netbsd*
3413 NetBSD/sparc sparc-*-netbsd*
3414 OpenBSD/amd64 x86_64-*-openbsd*
3415 OpenBSD/i386 i?86-*-openbsd*
3416 OpenBSD/m68k m68*-openbsd*
3417 OpenBSD/sparc sparc-*-openbsd*
3419 * Signal trampoline code overhauled
3421 Many generic problems with GDB's signal handling code have been fixed.
3422 These include: backtraces through non-contiguous stacks; recognition
3423 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3424 call; backtrace through a signal trampoline; step into and out of
3425 signal handlers; and single-stepping in the signal trampoline.
3427 Please note that kernel bugs are a limiting factor here. These
3428 features have been shown to work on an s390 GNU/Linux system that
3429 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3431 * Cygwin support for DWARF 2 added.
3433 * New native configurations
3435 GNU/Linux/hppa hppa*-*-linux*
3436 OpenBSD/hppa hppa*-*-openbsd*
3437 OpenBSD/m68k m68*-*-openbsd*
3438 OpenBSD/m88k m88*-*-openbsd*
3439 OpenBSD/powerpc powerpc-*-openbsd*
3440 NetBSD/vax vax-*-netbsd*
3441 OpenBSD/vax vax-*-openbsd*
3443 * END-OF-LIFE frame compatibility module
3445 GDB's internal frame infrastructure has been completely rewritten.
3446 The new infrastructure making it possible to support key new features
3447 including DWARF 2 Call Frame Information. To aid in the task of
3448 migrating old configurations to this new infrastructure, a
3449 compatibility module, that allowed old configurations to continue to
3450 work, was also included.
3452 GDB 6.2 will be the last release to include this frame compatibility
3453 module. This change directly impacts the following configurations:
3463 Unless there is activity to revive these configurations, they will be
3464 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3466 * REMOVED configurations and files
3468 Sun 3, running SunOS 3 m68*-*-sunos3*
3469 Sun 3, running SunOS 4 m68*-*-sunos4*
3470 Sun 2, running SunOS 3 m68000-*-sunos3*
3471 Sun 2, running SunOS 4 m68000-*-sunos4*
3472 Motorola 680x0 running LynxOS m68*-*-lynxos*
3473 AT&T 3b1/Unix pc m68*-att-*
3474 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3475 decstation mips-dec-* mips-little-*
3476 riscos mips-*-riscos* mips-*-sysv*
3477 sonymips mips-sony-*
3478 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3480 *** Changes in GDB 6.1.1:
3482 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3484 The TUI (Text-mode User Interface) is now built as part of a default
3485 GDB configuration. It is enabled by either selecting the TUI with the
3486 command line option "-i=tui" or by running the separate "gdbtui"
3487 program. For more information on the TUI, see the manual "Debugging
3490 * Pending breakpoint support (also included in GDB 6.1)
3492 Support has been added to allow you to specify breakpoints in shared
3493 libraries that have not yet been loaded. If a breakpoint location
3494 cannot be found, and the "breakpoint pending" option is set to auto,
3495 GDB queries you if you wish to make the breakpoint pending on a future
3496 shared-library load. If and when GDB resolves the breakpoint symbol,
3497 the pending breakpoint is removed as one or more regular breakpoints
3500 Pending breakpoints are very useful for GCJ Java debugging.
3502 * Fixed ISO-C build problems
3504 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3505 non ISO-C code that stopped them being built using a more strict ISO-C
3506 compiler (e.g., IBM's C compiler).
3508 * Fixed build problem on IRIX 5
3510 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3511 wasn't able to compile compile on an IRIX 5 system.
3513 * Added execute permission to gdb/gdbserver/configure
3515 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3516 permission. This bug would cause configure to fail on a number of
3517 systems (Solaris, IRIX). Ref: server/519.
3519 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3521 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3522 has been updated to use constant array sizes.
3524 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3526 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3527 its generated DWARF Call Frame Info. This encoding was causing GDB to
3528 panic, that panic has been fixed. Ref: gdb/1628.
3530 * Fixed a problem when examining parameters in shared library code.
3532 When examining parameters in optimized shared library code generated
3533 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3534 not available''. GDB now correctly displays the variable's value.
3536 *** Changes in GDB 6.1:
3538 * Removed --with-mmalloc
3540 Support for the mmalloc memory manager has been removed, as it
3541 conflicted with the internal gdb byte cache.
3543 * Changes in AMD64 configurations
3545 The AMD64 target now includes the %cs and %ss registers. As a result
3546 the AMD64 remote protocol has changed; this affects the floating-point
3547 and SSE registers. If you rely on those registers for your debugging,
3548 you should upgrade gdbserver on the remote side.
3550 * Revised SPARC target
3552 The SPARC target has been completely revised, incorporating the
3553 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3554 support for LynxOS and SunOS 4 has been dropped. Calling functions
3555 from within GDB on operating systems with a non-executable stack
3556 (Solaris, OpenBSD) now works.
3560 GDB has a new C++ demangler which does a better job on the mangled
3561 names generated by current versions of g++. It also runs faster, so
3562 with this and other changes gdb should now start faster on large C++
3565 * DWARF 2 Location Expressions
3567 GDB support for location expressions has been extended to support function
3568 arguments and frame bases. Older versions of GDB could crash when they
3571 * C++ nested types and namespaces
3573 GDB's support for nested types and namespaces in C++ has been
3574 improved, especially if you use the DWARF 2 debugging format. (This
3575 is the default for recent versions of GCC on most platforms.)
3576 Specifically, if you have a class "Inner" defined within a class or
3577 namespace "Outer", then GDB realizes that the class's name is
3578 "Outer::Inner", not simply "Inner". This should greatly reduce the
3579 frequency of complaints about not finding RTTI symbols. In addition,
3580 if you are stopped at inside of a function defined within a namespace,
3581 GDB modifies its name lookup accordingly.
3583 * New native configurations
3585 NetBSD/amd64 x86_64-*-netbsd*
3586 OpenBSD/amd64 x86_64-*-openbsd*
3587 OpenBSD/alpha alpha*-*-openbsd*
3588 OpenBSD/sparc sparc-*-openbsd*
3589 OpenBSD/sparc64 sparc64-*-openbsd*
3591 * New debugging protocols
3593 M32R with SDI protocol m32r-*-elf*
3595 * "set prompt-escape-char" command deleted.
3597 The command "set prompt-escape-char" has been deleted. This command,
3598 and its very obscure effet on GDB's prompt, was never documented,
3599 tested, nor mentioned in the NEWS file.
3601 * OBSOLETE configurations and files
3603 Configurations that have been declared obsolete in this release have
3604 been commented out. Unless there is activity to revive these
3605 configurations, the next release of GDB will have their sources
3606 permanently REMOVED.
3608 Sun 3, running SunOS 3 m68*-*-sunos3*
3609 Sun 3, running SunOS 4 m68*-*-sunos4*
3610 Sun 2, running SunOS 3 m68000-*-sunos3*
3611 Sun 2, running SunOS 4 m68000-*-sunos4*
3612 Motorola 680x0 running LynxOS m68*-*-lynxos*
3613 AT&T 3b1/Unix pc m68*-att-*
3614 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3615 decstation mips-dec-* mips-little-*
3616 riscos mips-*-riscos* mips-*-sysv*
3617 sonymips mips-sony-*
3618 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3620 * REMOVED configurations and files
3622 SGI Irix-4.x mips-sgi-irix4 or iris4
3623 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3624 Z8000 simulator z8k-zilog-none or z8ksim
3625 Matsushita MN10200 w/simulator mn10200-*-*
3626 H8/500 simulator h8500-hitachi-hms or h8500hms
3627 HP/PA running BSD hppa*-*-bsd*
3628 HP/PA running OSF/1 hppa*-*-osf*
3629 HP/PA Pro target hppa*-*-pro*
3630 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3631 386BSD i[3456]86-*-bsd*
3632 Sequent family i[3456]86-sequent-sysv4*
3633 i[3456]86-sequent-sysv*
3634 i[3456]86-sequent-bsd*
3635 SPARC running LynxOS sparc-*-lynxos*
3636 SPARC running SunOS 4 sparc-*-sunos4*
3637 Tsqware Sparclet sparclet-*-*
3638 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3640 *** Changes in GDB 6.0:
3644 Support for debugging the Objective-C programming language has been
3645 integrated into GDB.
3647 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3649 DWARF 2's Call Frame Information makes available compiler generated
3650 information that more exactly describes the program's run-time stack.
3651 By using this information, GDB is able to provide more robust stack
3654 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3655 have been updated to use a new backtrace mechanism which includes
3656 DWARF 2 CFI support.
3660 GDB's remote protocol has been extended to include support for hosted
3661 file I/O (where the remote target uses GDB's file system). See GDB's
3662 remote protocol documentation for details.
3664 * All targets using the new architecture framework.
3666 All of GDB's targets have been updated to use the new internal
3667 architecture framework. The way is now open for future GDB releases
3668 to include cross-architecture native debugging support (i386 on amd64,
3671 * GNU/Linux's Thread Local Storage (TLS)
3673 GDB now includes support for for the GNU/Linux implementation of
3674 per-thread variables.
3676 * GNU/Linux's Native POSIX Thread Library (NPTL)
3678 GDB's thread code has been updated to work with either the new
3679 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3681 * Separate debug info.
3683 GDB, in conjunction with BINUTILS, now supports a mechanism for
3684 automatically loading debug information from a separate file. Instead
3685 of shipping full debug and non-debug versions of system libraries,
3686 system integrators can now instead ship just the stripped libraries
3687 and optional debug files.
3689 * DWARF 2 Location Expressions
3691 DWARF 2 Location Expressions allow the compiler to more completely
3692 describe the location of variables (even in optimized code) to the
3695 GDB now includes preliminary support for location expressions (support
3696 for DW_OP_piece is still missing).
3700 A number of long standing bugs that caused GDB to die while starting a
3701 Java application have been fixed. GDB's Java support is now
3702 considered "useable".
3704 * GNU/Linux support for fork, vfork, and exec.
3706 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3707 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3710 * GDB supports logging output to a file
3712 There are two new commands, "set logging" and "show logging", which can be
3713 used to capture GDB's output to a file.
3715 * The meaning of "detach" has changed for gdbserver
3717 The "detach" command will now resume the application, as documented. To
3718 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3721 * d10v, m68hc11 `regs' command deprecated
3723 The `info registers' command has been updated so that it displays the
3724 registers using a format identical to the old `regs' command.
3728 A new command, "maint set profile on/off", has been added. This command can
3729 be used to enable or disable profiling while running GDB, to profile a
3730 session or a set of commands. In addition there is a new configure switch,
3731 "--enable-profiling", which will cause GDB to be compiled with profiling
3732 data, for more informative profiling results.
3734 * Default MI syntax changed to "mi2".
3736 The default MI (machine interface) syntax, enabled by the command line
3737 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3738 "mi1", can be enabled by specifying the option "-i=mi1".
3740 Support for the original "mi0" syntax (included in GDB 5.0) has been
3743 Fix for gdb/192: removed extraneous space when displaying frame level.
3744 Fix for gdb/672: update changelist is now output in mi list format.
3745 Fix for gdb/702: a -var-assign that updates the value now shows up
3746 in a subsequent -var-update.
3748 * New native configurations.
3750 FreeBSD/amd64 x86_64-*-freebsd*
3752 * Multi-arched targets.
3754 HP/PA HPUX11 hppa*-*-hpux*
3755 Renesas M32R/D w/simulator m32r-*-elf*
3757 * OBSOLETE configurations and files
3759 Configurations that have been declared obsolete in this release have
3760 been commented out. Unless there is activity to revive these
3761 configurations, the next release of GDB will have their sources
3762 permanently REMOVED.
3764 Z8000 simulator z8k-zilog-none or z8ksim
3765 Matsushita MN10200 w/simulator mn10200-*-*
3766 H8/500 simulator h8500-hitachi-hms or h8500hms
3767 HP/PA running BSD hppa*-*-bsd*
3768 HP/PA running OSF/1 hppa*-*-osf*
3769 HP/PA Pro target hppa*-*-pro*
3770 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3771 Sequent family i[3456]86-sequent-sysv4*
3772 i[3456]86-sequent-sysv*
3773 i[3456]86-sequent-bsd*
3774 Tsqware Sparclet sparclet-*-*
3775 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3777 * REMOVED configurations and files
3780 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3781 IBM AIX PS/2 i[3456]86-*-aix
3782 i386 running Mach 3.0 i[3456]86-*-mach3*
3783 i386 running Mach i[3456]86-*-mach*
3784 i386 running OSF/1 i[3456]86-*osf1mk*
3785 HP/Apollo 68k Family m68*-apollo*-sysv*,
3787 m68*-hp-bsd*, m68*-hp-hpux*
3788 Argonaut Risc Chip (ARC) arc-*-*
3789 Mitsubishi D30V d30v-*-*
3790 Fujitsu FR30 fr30-*-elf*
3791 OS/9000 i[34]86-*-os9k
3792 I960 with MON960 i960-*-coff
3794 * MIPS $fp behavior changed
3796 The convenience variable $fp, for the MIPS, now consistently returns
3797 the address of the current frame's base. Previously, depending on the
3798 context, $fp could refer to either $sp or the current frame's base
3799 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3800 The GNU Source-Level Debugger''.
3802 *** Changes in GDB 5.3:
3804 * GNU/Linux shared library multi-threaded performance improved.
3806 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3807 `/proc', in preference to `ptrace' for memory reads. This may result
3808 in an improvement in the start-up time of multi-threaded, shared
3809 library applications when run under GDB. One GDB user writes: ``loads
3810 shared libs like mad''.
3812 * ``gdbserver'' now supports multi-threaded applications on some targets
3814 Support for debugging multi-threaded applications which use
3815 the GNU/Linux LinuxThreads package has been added for
3816 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3817 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3819 * GDB now supports C/C++ preprocessor macros.
3821 GDB now expands preprocessor macro invocations in C/C++ expressions,
3822 and provides various commands for showing macro definitions and how
3825 The new command `macro expand EXPRESSION' expands any macro
3826 invocations in expression, and shows the result.
3828 The new command `show macro MACRO-NAME' shows the definition of the
3829 macro named MACRO-NAME, and where it was defined.
3831 Most compilers don't include information about macros in the debugging
3832 information by default. In GCC 3.1, for example, you need to compile
3833 your program with the options `-gdwarf-2 -g3'. If the macro
3834 information is present in the executable, GDB will read it.
3836 * Multi-arched targets.
3838 DEC Alpha (partial) alpha*-*-*
3839 DEC VAX (partial) vax-*-*
3841 National Semiconductor NS32000 (partial) ns32k-*-*
3842 Motorola 68000 (partial) m68k-*-*
3843 Motorola MCORE mcore-*-*
3847 Fujitsu FRV architecture added by Red Hat frv*-*-*
3850 * New native configurations
3852 Alpha NetBSD alpha*-*-netbsd*
3853 SH NetBSD sh*-*-netbsdelf*
3854 MIPS NetBSD mips*-*-netbsd*
3855 UltraSPARC NetBSD sparc64-*-netbsd*
3857 * OBSOLETE configurations and files
3859 Configurations that have been declared obsolete in this release have
3860 been commented out. Unless there is activity to revive these
3861 configurations, the next release of GDB will have their sources
3862 permanently REMOVED.
3864 Mitsubishi D30V d30v-*-*
3865 OS/9000 i[34]86-*-os9k
3866 IBM AIX PS/2 i[3456]86-*-aix
3867 Fujitsu FR30 fr30-*-elf*
3868 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3869 Argonaut Risc Chip (ARC) arc-*-*
3870 i386 running Mach 3.0 i[3456]86-*-mach3*
3871 i386 running Mach i[3456]86-*-mach*
3872 i386 running OSF/1 i[3456]86-*osf1mk*
3873 HP/Apollo 68k Family m68*-apollo*-sysv*,
3875 m68*-hp-bsd*, m68*-hp-hpux*
3876 I960 with MON960 i960-*-coff
3878 * OBSOLETE languages
3880 CHILL, a Pascal like language used by telecommunications companies.
3882 * REMOVED configurations and files
3884 AMD 29k family via UDI a29k-amd-udi, udi29k
3885 A29K VxWorks a29k-*-vxworks
3886 AMD 29000 embedded, using EBMON a29k-none-none
3887 AMD 29000 embedded with COFF a29k-none-coff
3888 AMD 29000 embedded with a.out a29k-none-aout
3890 testsuite/gdb.hp/gdb.threads-hp/ directory
3892 * New command "set max-user-call-depth <nnn>"
3894 This command allows the user to limit the call depth of user-defined
3895 commands. The default is 1024.
3897 * Changes in FreeBSD/i386 native debugging.
3899 Support for the "generate-core-file" has been added.
3901 * New commands "dump", "append", and "restore".
3903 These commands allow data to be copied from target memory
3904 to a bfd-format or binary file (dump and append), and back
3905 from a file into memory (restore).
3907 * Improved "next/step" support on multi-processor Alpha Tru64.
3909 The previous single-step mechanism could cause unpredictable problems,
3910 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3911 of a software single-step mechanism prevents this.
3913 *** Changes in GDB 5.2.1:
3921 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3922 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3923 Fix, by Joel Brobecker imported from mainline.
3925 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3926 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3927 Fix, by Fred Fish, imported from mainline.
3929 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3930 Surprisingly enough, it works now.
3931 By Michal Ludvig, imported from mainline.
3933 i386 hardware watchpoint support:
3934 avoid misses on second run for some targets.
3935 By Pierre Muller, imported from mainline.
3937 *** Changes in GDB 5.2:
3939 * New command "set trust-readonly-sections on[off]".
3941 This command is a hint that tells gdb that read-only sections
3942 really are read-only (ie. that their contents will not change).
3943 In this mode, gdb will go to the object file rather than the
3944 target to read memory from read-only sections (such as ".text").
3945 This can be a significant performance improvement on some
3946 (notably embedded) targets.
3948 * New command "generate-core-file" (or "gcore").
3950 This new gdb command allows the user to drop a core file of the child
3951 process state at any time. So far it's been implemented only for
3952 GNU/Linux and Solaris, but should be relatively easily ported to other
3953 hosts. Argument is core file name (defaults to core.<pid>).
3955 * New command line option
3957 GDB now accepts --pid or -p followed by a process id.
3959 * Change in command line behavior -- corefiles vs. process ids.
3961 There is a subtle behavior in the way in which GDB handles
3962 command line arguments. The first non-flag argument is always
3963 a program to debug, but the second non-flag argument may either
3964 be a corefile or a process id. Previously, GDB would attempt to
3965 open the second argument as a corefile, and if that failed, would
3966 issue a superfluous error message and then attempt to attach it as
3967 a process. Now, if the second argument begins with a non-digit,
3968 it will be treated as a corefile. If it begins with a digit,
3969 GDB will attempt to attach it as a process, and if no such process
3970 is found, will then attempt to open it as a corefile.
3972 * Changes in ARM configurations.
3974 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3975 configuration is fully multi-arch.
3977 * New native configurations
3979 ARM NetBSD arm*-*-netbsd*
3980 x86 OpenBSD i[3456]86-*-openbsd*
3981 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3982 Sparc64 running FreeBSD sparc64-*-freebsd*
3986 Sanyo XStormy16 xstormy16-elf
3988 * OBSOLETE configurations and files
3990 Configurations that have been declared obsolete in this release have
3991 been commented out. Unless there is activity to revive these
3992 configurations, the next release of GDB will have their sources
3993 permanently REMOVED.
3995 AMD 29k family via UDI a29k-amd-udi, udi29k
3996 A29K VxWorks a29k-*-vxworks
3997 AMD 29000 embedded, using EBMON a29k-none-none
3998 AMD 29000 embedded with COFF a29k-none-coff
3999 AMD 29000 embedded with a.out a29k-none-aout
4001 testsuite/gdb.hp/gdb.threads-hp/ directory
4003 * REMOVED configurations and files
4005 TI TMS320C80 tic80-*-*
4007 PowerPC Solaris powerpcle-*-solaris*
4008 PowerPC Windows NT powerpcle-*-cygwin32
4009 PowerPC Netware powerpc-*-netware*
4010 Harris/CXUX m88k m88*-harris-cxux*
4011 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4012 ns32k-utek-sysv* ns32k-utek-*
4013 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4014 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4015 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4016 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4017 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4019 * Changes to command line processing
4021 The new `--args' feature can be used to specify command-line arguments
4022 for the inferior from gdb's command line.
4024 * Changes to key bindings
4026 There is a new `operate-and-get-next' function bound to `C-o'.
4028 *** Changes in GDB 5.1.1
4030 Fix compile problem on DJGPP.
4032 Fix a problem with floating-point registers on the i386 being
4035 Fix to stop GDB crashing on .debug_str debug info.
4037 Numerous documentation fixes.
4039 Numerous testsuite fixes.
4041 *** Changes in GDB 5.1:
4043 * New native configurations
4045 Alpha FreeBSD alpha*-*-freebsd*
4046 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4047 MIPS GNU/Linux mips*-*-linux*
4048 MIPS SGI Irix 6.x mips*-sgi-irix6*
4049 ia64 AIX ia64-*-aix*
4050 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4054 Motorola 68HC11 and 68HC12 m68hc11-elf
4056 UltraSparc running GNU/Linux sparc64-*-linux*
4058 * OBSOLETE configurations and files
4060 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4061 Harris/CXUX m88k m88*-harris-cxux*
4062 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4063 ns32k-utek-sysv* ns32k-utek-*
4064 TI TMS320C80 tic80-*-*
4066 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4067 PowerPC Solaris powerpcle-*-solaris*
4068 PowerPC Windows NT powerpcle-*-cygwin32
4069 PowerPC Netware powerpc-*-netware*
4070 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4071 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4072 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4073 Apple Macintosh (MPW) host N/A
4075 stuff.c (Program to stuff files into a specially prepared space in kdb)
4076 kdb-start.c (Main loop for the standalone kernel debugger)
4078 Configurations that have been declared obsolete in this release have
4079 been commented out. Unless there is activity to revive these
4080 configurations, the next release of GDB will have their sources
4081 permanently REMOVED.
4083 * REMOVED configurations and files
4085 Altos 3068 m68*-altos-*
4086 Convex c1-*-*, c2-*-*
4088 ARM RISCix arm-*-* (as host)
4092 * GDB has been converted to ISO C.
4094 GDB's source code has been converted to ISO C. In particular, the
4095 sources are fully protoized, and rely on standard headers being
4100 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4102 * The MI enabled by default.
4104 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4105 revised and enabled by default. Packages which use GDB as a debugging
4106 engine behind a UI or another front end are encouraged to switch to
4107 using the GDB/MI interface, instead of the old annotations interface
4108 which is now deprecated.
4110 * Support for debugging Pascal programs.
4112 GDB now includes support for debugging Pascal programs. The following
4113 main features are supported:
4115 - Pascal-specific data types such as sets;
4117 - automatic recognition of Pascal sources based on file-name
4120 - Pascal-style display of data types, variables, and functions;
4122 - a Pascal expression parser.
4124 However, some important features are not yet supported.
4126 - Pascal string operations are not supported at all;
4128 - there are some problems with boolean types;
4130 - Pascal type hexadecimal constants are not supported
4131 because they conflict with the internal variables format;
4133 - support for Pascal objects and classes is not full yet;
4135 - unlike Pascal, GDB is case-sensitive for symbol names.
4137 * Changes in completion.
4139 Commands such as `shell', `run' and `set args', which pass arguments
4140 to inferior programs, now complete on file names, similar to what
4141 users expect at the shell prompt.
4143 Commands which accept locations, such as `disassemble', `print',
4144 `breakpoint', `until', etc. now complete on filenames as well as
4145 program symbols. Thus, if you type "break foob TAB", and the source
4146 files linked into the programs include `foobar.c', that file name will
4147 be one of the candidates for completion. However, file names are not
4148 considered for completion after you typed a colon that delimits a file
4149 name from a name of a function in that file, as in "break foo.c:bar".
4151 `set demangle-style' completes on available demangling styles.
4153 * New platform-independent commands:
4155 It is now possible to define a post-hook for a command as well as a
4156 hook that runs before the command. For more details, see the
4157 documentation of `hookpost' in the GDB manual.
4159 * Changes in GNU/Linux native debugging.
4161 Support for debugging multi-threaded programs has been completely
4162 revised for all platforms except m68k and sparc. You can now debug as
4163 many threads as your system allows you to have.
4165 Attach/detach is supported for multi-threaded programs.
4167 Support for SSE registers was added for x86. This doesn't work for
4168 multi-threaded programs though.
4170 * Changes in MIPS configurations.
4172 Multi-arch support is enabled for all MIPS configurations.
4174 GDB can now be built as native debugger on SGI Irix 6.x systems for
4175 debugging n32 executables. (Debugging 64-bit executables is not yet
4178 * Unified support for hardware watchpoints in all x86 configurations.
4180 Most (if not all) native x86 configurations support hardware-assisted
4181 breakpoints and watchpoints in a unified manner. This support
4182 implements debug register sharing between watchpoints, which allows to
4183 put a virtually infinite number of watchpoints on the same address,
4184 and also supports watching regions up to 16 bytes with several debug
4187 The new maintenance command `maintenance show-debug-regs' toggles
4188 debugging print-outs in functions that insert, remove, and test
4189 watchpoints and hardware breakpoints.
4191 * Changes in the DJGPP native configuration.
4193 New command ``info dos sysinfo'' displays assorted information about
4194 the CPU, OS, memory, and DPMI server.
4196 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4197 display information about segment descriptors stored in GDT, LDT, and
4200 New commands ``info dos pde'' and ``info dos pte'' display entries
4201 from Page Directory and Page Tables (for now works with CWSDPMI only).
4202 New command ``info dos address-pte'' displays the Page Table entry for
4203 a given linear address.
4205 GDB can now pass command lines longer than 126 characters to the
4206 program being debugged (requires an update to the libdbg.a library
4207 which is part of the DJGPP development kit).
4209 DWARF2 debug info is now supported.
4211 It is now possible to `step' and `next' through calls to `longjmp'.
4213 * Changes in documentation.
4215 All GDB documentation was converted to GFDL, the GNU Free
4216 Documentation License.
4218 Tracepoints-related commands are now fully documented in the GDB
4221 TUI, the Text-mode User Interface, is now documented in the manual.
4223 Tracepoints-related commands are now fully documented in the GDB
4226 The "GDB Internals" manual now has an index. It also includes
4227 documentation of `ui_out' functions, GDB coding standards, x86
4228 hardware watchpoints, and memory region attributes.
4230 * GDB's version number moved to ``version.in''
4232 The Makefile variable VERSION has been replaced by the file
4233 ``version.in''. People creating GDB distributions should update the
4234 contents of this file.
4238 GUD support is now a standard part of the EMACS distribution.
4240 *** Changes in GDB 5.0:
4242 * Improved support for debugging FP programs on x86 targets
4244 Unified and much-improved support for debugging floating-point
4245 programs on all x86 targets. In particular, ``info float'' now
4246 displays the FP registers in the same format on all x86 targets, with
4247 greater level of detail.
4249 * Improvements and bugfixes in hardware-assisted watchpoints
4251 It is now possible to watch array elements, struct members, and
4252 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4253 on x86 targets no longer erroneously trigger when the address is
4256 * Improvements in the native DJGPP version of GDB
4258 The distribution now includes all the scripts and auxiliary files
4259 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4260 machines ``out of the box''.
4262 The DJGPP version can now debug programs that use signals. It is
4263 possible to catch signals that happened in the debuggee, deliver
4264 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4265 would kill the program being debugged.) Programs that hook hardware
4266 interrupts (keyboard, timer, etc.) can also be debugged.
4268 It is now possible to debug DJGPP programs that redirect their
4269 standard handles or switch them to raw (as opposed to cooked) mode, or
4270 even close them. The command ``run < foo > bar'' works as expected,
4271 and ``info terminal'' reports useful information about the debuggee's
4272 terminal, including raw/cooked mode, redirection, etc.
4274 The DJGPP version now uses termios functions for console I/O, which
4275 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4278 DOS-style file names with drive letters are now fully supported by
4281 It is now possible to debug DJGPP programs that switch their working
4282 directory. It is also possible to rerun the debuggee any number of
4283 times without restarting GDB; thus, you can use the same setup,
4284 breakpoints, etc. for many debugging sessions.
4286 * New native configurations
4288 ARM GNU/Linux arm*-*-linux*
4289 PowerPC GNU/Linux powerpc-*-linux*
4293 Motorola MCore mcore-*-*
4294 x86 VxWorks i[3456]86-*-vxworks*
4295 PowerPC VxWorks powerpc-*-vxworks*
4296 TI TMS320C80 tic80-*-*
4298 * OBSOLETE configurations
4300 Altos 3068 m68*-altos-*
4301 Convex c1-*-*, c2-*-*
4303 ARM RISCix arm-*-* (as host)
4306 Configurations that have been declared obsolete will be commented out,
4307 but the code will be left in place. If there is no activity to revive
4308 these configurations before the next release of GDB, the sources will
4309 be permanently REMOVED.
4311 * Gould support removed
4313 Support for the Gould PowerNode and NP1 has been removed.
4315 * New features for SVR4
4317 On SVR4 native platforms (such as Solaris), if you attach to a process
4318 without first loading a symbol file, GDB will now attempt to locate and
4319 load symbols from the running process's executable file.
4321 * Many C++ enhancements
4323 C++ support has been greatly improved. Overload resolution now works properly
4324 in almost all cases. RTTI support is on the way.
4326 * Remote targets can connect to a sub-program
4328 A popen(3) style serial-device has been added. This device starts a
4329 sub-process (such as a stand-alone simulator) and then communicates
4330 with that. The sub-program to run is specified using the syntax
4331 ``|<program> <args>'' vis:
4333 (gdb) set remotedebug 1
4334 (gdb) target extended-remote |mn10300-elf-sim program-args
4336 * MIPS 64 remote protocol
4338 A long standing bug in the mips64 remote protocol where by GDB
4339 expected certain 32 bit registers (ex SR) to be transfered as 32
4340 instead of 64 bits has been fixed.
4342 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4343 added to provide backward compatibility with older versions of GDB.
4345 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4347 The command ``set remotebinarydownload'' command has been replaced by
4348 ``set remote X-packet''. Other commands in ``set remote'' family
4349 include ``set remote P-packet''.
4351 * Breakpoint commands accept ranges.
4353 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4354 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4355 ``tracepoint passcount'' also accepts a range of tracepoints.
4357 * ``apropos'' command added.
4359 The ``apropos'' command searches through command names and
4360 documentation strings, printing out matches, making it much easier to
4361 try to find a command that does what you are looking for.
4365 A new machine oriented interface (MI) has been added to GDB. This
4366 interface is designed for debug environments running GDB as a separate
4367 process. This is part of the long term libGDB project. See the
4368 "GDB/MI" chapter of the GDB manual for further information. It can be
4369 enabled by configuring with:
4371 .../configure --enable-gdbmi
4373 *** Changes in GDB-4.18:
4375 * New native configurations
4377 HP-UX 10.20 hppa*-*-hpux10.20
4378 HP-UX 11.x hppa*-*-hpux11.0*
4379 M68K GNU/Linux m68*-*-linux*
4383 Fujitsu FR30 fr30-*-elf*
4384 Intel StrongARM strongarm-*-*
4385 Mitsubishi D30V d30v-*-*
4387 * OBSOLETE configurations
4389 Gould PowerNode, NP1 np1-*-*, pn-*-*
4391 Configurations that have been declared obsolete will be commented out,
4392 but the code will be left in place. If there is no activity to revive
4393 these configurations before the next release of GDB, the sources will
4394 be permanently REMOVED.
4398 As a compatibility experiment, GDB's source files buildsym.h and
4399 buildsym.c have been converted to pure standard C, no longer
4400 containing any K&R compatibility code. We believe that all systems in
4401 use today either come with a standard C compiler, or have a GCC port
4402 available. If this is not true, please report the affected
4403 configuration to bug-gdb@gnu.org immediately. See the README file for
4404 information about getting a standard C compiler if you don't have one
4409 GDB now uses readline 2.2.
4411 * set extension-language
4413 You can now control the mapping between filename extensions and source
4414 languages by using the `set extension-language' command. For instance,
4415 you can ask GDB to treat .c files as C++ by saying
4416 set extension-language .c c++
4417 The command `info extensions' lists all of the recognized extensions
4418 and their associated languages.
4420 * Setting processor type for PowerPC and RS/6000
4422 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4423 you can use the `set processor' command to specify what variant of the
4424 PowerPC family you are debugging. The command
4428 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4429 following PowerPC and RS6000 variants:
4431 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4432 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4434 403GC IBM PowerPC 403GC
4435 505 Motorola PowerPC 505
4436 860 Motorola PowerPC 860 or 850
4437 601 Motorola PowerPC 601
4438 602 Motorola PowerPC 602
4439 603 Motorola/IBM PowerPC 603 or 603e
4440 604 Motorola PowerPC 604 or 604e
4441 750 Motorola/IBM PowerPC 750 or 750
4443 At the moment, this command just tells GDB what to name the
4444 special-purpose processor registers. Since almost all the affected
4445 registers are inaccessible to user-level programs, this command is
4446 only useful for remote debugging in its present form.
4450 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4451 more extensive support for HP-UX. Added features include shared
4452 library support, kernel threads and hardware watchpoints for 11.00,
4453 support for HP's ANSI C and C++ compilers, and a compatibility mode
4454 for xdb and dbx commands.
4458 HP's donation includes the new concept of catchpoints, which is a
4459 generalization of the old catch command. On HP-UX, it is now possible
4460 to catch exec, fork, and vfork, as well as library loading.
4462 This means that the existing catch command has changed; its first
4463 argument now specifies the type of catch to be set up. See the
4464 output of "help catch" for a list of catchpoint types.
4466 * Debugging across forks
4468 On HP-UX, you can choose which process to debug when a fork() happens
4473 HP has donated a curses-based terminal user interface (TUI). To get
4474 it, build with --enable-tui. Although this can be enabled for any
4475 configuration, at present it only works for native HP debugging.
4477 * GDB remote protocol additions
4479 A new protocol packet 'X' that writes binary data is now available.
4480 Default behavior is to try 'X', then drop back to 'M' if the stub
4481 fails to respond. The settable variable `remotebinarydownload'
4482 allows explicit control over the use of 'X'.
4484 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4485 full 64-bit address. The command
4487 set remoteaddresssize 32
4489 can be used to revert to the old behaviour. For existing remote stubs
4490 the change should not be noticed, as the additional address information
4493 In order to assist in debugging stubs, you may use the maintenance
4494 command `packet' to send any text string to the stub. For instance,
4496 maint packet heythere
4498 sends the packet "$heythere#<checksum>". Note that it is very easy to
4499 disrupt a debugging session by sending the wrong packet at the wrong
4502 The compare-sections command allows you to compare section data on the
4503 target to what is in the executable file without uploading or
4504 downloading, by comparing CRC checksums.
4506 * Tracing can collect general expressions
4508 You may now collect general expressions at tracepoints. This requires
4509 further additions to the target-side stub; see tracepoint.c and
4510 doc/agentexpr.texi for further details.
4512 * mask-address variable for Mips
4514 For Mips targets, you may control the zeroing of the upper 32 bits of
4515 a 64-bit address by entering `set mask-address on'. This is mainly
4516 of interest to users of embedded R4xxx and R5xxx processors.
4518 * Higher serial baud rates
4520 GDB's serial code now allows you to specify baud rates 57600, 115200,
4521 230400, and 460800 baud. (Note that your host system may not be able
4522 to achieve all of these rates.)
4526 The i960 configuration now includes an initial implementation of a
4527 builtin simulator, contributed by Jim Wilson.
4530 *** Changes in GDB-4.17:
4532 * New native configurations
4534 Alpha GNU/Linux alpha*-*-linux*
4535 Unixware 2.x i[3456]86-unixware2*
4536 Irix 6.x mips*-sgi-irix6*
4537 PowerPC GNU/Linux powerpc-*-linux*
4538 PowerPC Solaris powerpcle-*-solaris*
4539 Sparc GNU/Linux sparc-*-linux*
4540 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4544 Argonaut Risc Chip (ARC) arc-*-*
4545 Hitachi H8/300S h8300*-*-*
4546 Matsushita MN10200 w/simulator mn10200-*-*
4547 Matsushita MN10300 w/simulator mn10300-*-*
4548 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4549 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4550 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4551 Mitsubishi D10V w/simulator d10v-*-*
4552 Mitsubishi M32R/D w/simulator m32r-*-elf*
4553 Tsqware Sparclet sparclet-*-*
4554 NEC V850 w/simulator v850-*-*
4556 * New debugging protocols
4558 ARM with RDI protocol arm*-*-*
4559 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4560 DDB and LSI variants of PMON protocol mips*-*-*
4561 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4562 PowerPC with SDS protocol powerpc{,le}-*-eabi
4563 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4567 All configurations can now understand and use the DWARF 2 debugging
4568 format. The choice is automatic, if the symbol file contains DWARF 2
4573 GDB now includes basic Java language support. This support is
4574 only useful with Java compilers that produce native machine code.
4576 * solib-absolute-prefix and solib-search-path
4578 For SunOS and SVR4 shared libraries, you may now set the prefix for
4579 loading absolute shared library symbol files, and the search path for
4580 locating non-absolute shared library symbol files.
4582 * Live range splitting
4584 GDB can now effectively debug code for which GCC has performed live
4585 range splitting as part of its optimization. See gdb/doc/LRS for
4586 more details on the expected format of the stabs information.
4590 GDB's support for the GNU Hurd, including thread debugging, has been
4591 updated to work with current versions of the Hurd.
4595 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4596 instruction set. ARM GDB automatically detects when Thumb
4597 instructions are in use, and adjusts disassembly and backtracing
4602 GDB's MIPS target configurations now handle the MIP16 16-bit
4607 GDB now includes support for overlays; if an executable has been
4608 linked such that multiple sections are based at the same address, GDB
4609 will decide which section to use for symbolic info. You can choose to
4610 control the decision manually, using overlay commands, or implement
4611 additional target-side support and use "overlay load-target" to bring
4612 in the overlay mapping. Do "help overlay" for more detail.
4616 The command "info symbol <address>" displays information about
4617 the symbol at the specified address.
4621 The standard remote protocol now includes an extension that allows
4622 asynchronous collection and display of trace data. This requires
4623 extensive support in the target-side debugging stub. Tracing mode
4624 includes a new interaction mode in GDB and new commands: see the
4625 file tracepoint.c for more details.
4629 Configurations for embedded MIPS now include a simulator contributed
4630 by Cygnus Solutions. The simulator supports the instruction sets
4631 of most MIPS variants.
4635 Sparc configurations may now include the ERC32 simulator contributed
4636 by the European Space Agency. The simulator is not built into
4637 Sparc targets by default; configure with --enable-sim to include it.
4641 For target configurations that may include multiple variants of a
4642 basic architecture (such as MIPS and SH), you may now set the
4643 architecture explicitly. "set arch" sets, "info arch" lists
4644 the possible architectures.
4646 *** Changes in GDB-4.16:
4648 * New native configurations
4650 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4651 M68K NetBSD m68k-*-netbsd*
4652 PowerPC AIX 4.x powerpc-*-aix*
4653 PowerPC MacOS powerpc-*-macos*
4654 PowerPC Windows NT powerpcle-*-cygwin32
4655 RS/6000 AIX 4.x rs6000-*-aix4*
4659 ARM with RDP protocol arm-*-*
4660 I960 with MON960 i960-*-coff
4661 MIPS VxWorks mips*-*-vxworks*
4662 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4663 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4665 Matra Sparclet sparclet-*-*
4669 The powerpc-eabi configuration now includes the PSIM simulator,
4670 contributed by Andrew Cagney, with assistance from Mike Meissner.
4671 PSIM is a very elaborate model of the PowerPC, including not only
4672 basic instruction set execution, but also details of execution unit
4673 performance and I/O hardware. See sim/ppc/README for more details.
4677 GDB now works with Solaris 2.5.
4679 * Windows 95/NT native
4681 GDB will now work as a native debugger on Windows 95 and Windows NT.
4682 To build it from source, you must use the "gnu-win32" environment,
4683 which uses a DLL to emulate enough of Unix to run the GNU tools.
4684 Further information, binaries, and sources are available at
4685 ftp.cygnus.com, under pub/gnu-win32.
4687 * dont-repeat command
4689 If a user-defined command includes the command `dont-repeat', then the
4690 command will not be repeated if the user just types return. This is
4691 useful if the command is time-consuming to run, so that accidental
4692 extra keystrokes don't run the same command many times.
4694 * Send break instead of ^C
4696 The standard remote protocol now includes an option to send a break
4697 rather than a ^C to the target in order to interrupt it. By default,
4698 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4700 * Remote protocol timeout
4702 The standard remote protocol includes a new variable `remotetimeout'
4703 that allows you to set the number of seconds before GDB gives up trying
4704 to read from the target. The default value is 2.
4706 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4708 By default GDB will automatically keep track of objects as they are
4709 loaded and unloaded by the dynamic linker. By using the command `set
4710 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4711 when shared library events occur, thus allowing you to set breakpoints
4712 in shared libraries which are explicitly loaded by the inferior.
4714 Note this feature does not work on hpux8. On hpux9 you must link
4715 /usr/lib/end.o into your program. This feature should work
4716 automatically on hpux10.
4718 * Irix 5.x hardware watchpoint support
4720 Irix 5 configurations now support the use of hardware watchpoints.
4722 * Mips protocol "SYN garbage limit"
4724 When debugging a Mips target using the `target mips' protocol, you
4725 may set the number of characters that GDB will ignore by setting
4726 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4727 every character. The default value is 1050.
4729 * Recording and replaying remote debug sessions
4731 If you set `remotelogfile' to the name of a file, gdb will write to it
4732 a recording of a remote debug session. This recording may then be
4733 replayed back to gdb using "gdbreplay". See gdbserver/README for
4734 details. This is useful when you have a problem with GDB while doing
4735 remote debugging; you can make a recording of the session and send it
4736 to someone else, who can then recreate the problem.
4738 * Speedups for remote debugging
4740 GDB includes speedups for downloading and stepping MIPS systems using
4741 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4742 and more efficient S-record downloading.
4744 * Memory use reductions and statistics collection
4746 GDB now uses less memory and reports statistics about memory usage.
4747 Try the `maint print statistics' command, for example.
4749 *** Changes in GDB-4.15:
4751 * Psymtabs for XCOFF
4753 The symbol reader for AIX GDB now uses partial symbol tables. This
4754 can greatly improve startup time, especially for large executables.
4756 * Remote targets use caching
4758 Remote targets now use a data cache to speed up communication with the
4759 remote side. The data cache could lead to incorrect results because
4760 it doesn't know about volatile variables, thus making it impossible to
4761 debug targets which use memory mapped I/O devices. `set remotecache
4762 off' turns the the data cache off.
4764 * Remote targets may have threads
4766 The standard remote protocol now includes support for multiple threads
4767 in the target system, using new protocol commands 'H' and 'T'. See
4768 gdb/remote.c for details.
4772 If GDB is configured with `--enable-netrom', then it will include
4773 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4774 acts as though it is a bank of ROM on the target board, but you can
4775 write into it over the network. GDB's support consists only of
4776 support for fast loading into the emulated ROM; to debug, you must use
4777 another protocol, such as standard remote protocol. The usual
4778 sequence is something like
4780 target nrom <netrom-hostname>
4782 target remote <netrom-hostname>:1235
4786 GDB now includes support for the Apple Macintosh, as a host only. It
4787 may be run as either an MPW tool or as a standalone application, and
4788 it can debug through the serial port. All the usual GDB commands are
4789 available, but to the target command, you must supply "serial" as the
4790 device type instead of "/dev/ttyXX". See mpw-README in the main
4791 directory for more information on how to build. The MPW configuration
4792 scripts */mpw-config.in support only a few targets, and only the
4793 mips-idt-ecoff target has been tested.
4797 GDB configuration now uses autoconf. This is not user-visible,
4798 but does simplify configuration and building.
4802 GDB now supports hpux10.
4804 *** Changes in GDB-4.14:
4806 * New native configurations
4808 x86 FreeBSD i[345]86-*-freebsd
4809 x86 NetBSD i[345]86-*-netbsd
4810 NS32k NetBSD ns32k-*-netbsd
4811 Sparc NetBSD sparc-*-netbsd
4815 A29K VxWorks a29k-*-vxworks
4816 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4817 CPU32 EST-300 emulator m68*-*-est*
4818 PowerPC ELF powerpc-*-elf
4821 * Alpha OSF/1 support for procfs
4823 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4824 possible to attach to running processes. As the mounting of the /proc
4825 filesystem is optional on the Alpha, GDB automatically determines
4826 the availability of /proc during startup. This can lead to problems
4827 if /proc is unmounted after GDB has been started.
4829 * Arguments to user-defined commands
4831 User commands may accept up to 10 arguments separated by whitespace.
4832 Arguments are accessed within the user command via $arg0..$arg9. A
4835 print $arg0 + $arg1 + $arg2
4837 To execute the command use:
4840 Defines the command "adder" which prints the sum of its three arguments.
4841 Note the arguments are text substitutions, so they may reference variables,
4842 use complex expressions, or even perform inferior function calls.
4844 * New `if' and `while' commands
4846 This makes it possible to write more sophisticated user-defined
4847 commands. Both commands take a single argument, which is the
4848 expression to evaluate, and must be followed by the commands to
4849 execute, one per line, if the expression is nonzero, the list being
4850 terminated by the word `end'. The `if' command list may include an
4851 `else' word, which causes the following commands to be executed only
4852 if the expression is zero.
4854 * Fortran source language mode
4856 GDB now includes partial support for Fortran 77. It will recognize
4857 Fortran programs and can evaluate a subset of Fortran expressions, but
4858 variables and functions may not be handled correctly. GDB will work
4859 with G77, but does not yet know much about symbols emitted by other
4862 * Better HPUX support
4864 Most debugging facilities now work on dynamic executables for HPPAs
4865 running hpux9 or later. You can attach to running dynamically linked
4866 processes, but by default the dynamic libraries will be read-only, so
4867 for instance you won't be able to put breakpoints in them. To change
4868 that behavior do the following before running the program:
4874 This will cause the libraries to be mapped private and read-write.
4875 To revert to the normal behavior, do this:
4881 You cannot set breakpoints or examine data in the library until after
4882 the library is loaded if the function/data symbols do not have
4885 GDB can now also read debug symbols produced by the HP C compiler on
4886 HPPAs (sorry, no C++, Fortran or 68k support).
4888 * Target byte order now dynamically selectable
4890 You can choose which byte order to use with a target system, via the
4891 commands "set endian big" and "set endian little", and you can see the
4892 current setting by using "show endian". You can also give the command
4893 "set endian auto", in which case GDB will use the byte order
4894 associated with the executable. Currently, only embedded MIPS
4895 configurations support dynamic selection of target byte order.
4897 * New DOS host serial code
4899 This version uses DPMI interrupts to handle buffered I/O, so you
4900 no longer need to run asynctsr when debugging boards connected to
4903 *** Changes in GDB-4.13:
4905 * New "complete" command
4907 This lists all the possible completions for the rest of the line, if it
4908 were to be given as a command itself. This is intended for use by emacs.
4910 * Trailing space optional in prompt
4912 "set prompt" no longer adds a space for you after the prompt you set. This
4913 allows you to set a prompt which ends in a space or one that does not.
4915 * Breakpoint hit counts
4917 "info break" now displays a count of the number of times the breakpoint
4918 has been hit. This is especially useful in conjunction with "ignore"; you
4919 can ignore a large number of breakpoint hits, look at the breakpoint info
4920 to see how many times the breakpoint was hit, then run again, ignoring one
4921 less than that number, and this will get you quickly to the last hit of
4924 * Ability to stop printing at NULL character
4926 "set print null-stop" will cause GDB to stop printing the characters of
4927 an array when the first NULL is encountered. This is useful when large
4928 arrays actually contain only short strings.
4930 * Shared library breakpoints
4932 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4933 breakpoints in shared libraries before the executable is run.
4935 * Hardware watchpoints
4937 There is a new hardware breakpoint for the watch command for sparclite
4938 targets. See gdb/sparclite/hw_breakpoint.note.
4940 Hardware watchpoints are also now supported under GNU/Linux.
4944 Annotations have been added. These are for use with graphical interfaces,
4945 and are still experimental. Currently only gdba.el uses these.
4947 * Improved Irix 5 support
4949 GDB now works properly with Irix 5.2.
4951 * Improved HPPA support
4953 GDB now works properly with the latest GCC and GAS.
4955 * New native configurations
4957 Sequent PTX4 i[34]86-sequent-ptx4
4958 HPPA running OSF/1 hppa*-*-osf*
4959 Atari TT running SVR4 m68*-*-sysv4*
4960 RS/6000 LynxOS rs6000-*-lynxos*
4964 OS/9000 i[34]86-*-os9k
4965 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4968 * Hitachi SH7000 and E7000-PC ICE support
4970 There is now support for communicating with the Hitachi E7000-PC ICE.
4971 This is available automatically when GDB is configured for the SH.
4975 As usual, a variety of small fixes and improvements, both generic
4976 and configuration-specific. See the ChangeLog for more detail.
4978 *** Changes in GDB-4.12:
4980 * Irix 5 is now supported
4984 GDB-4.12 on the HPPA has a number of changes which make it unable
4985 to debug the output from the currently released versions of GCC and
4986 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4987 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4988 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4991 *** Changes in GDB-4.11:
4993 * User visible changes:
4997 The "set remotedebug" option is now consistent between the mips remote
4998 target, remote targets using the gdb-specific protocol, UDI (AMD's
4999 debug protocol for the 29k) and the 88k bug monitor. It is now an
5000 integer specifying a debug level (normally 0 or 1, but 2 means more
5001 debugging info for the mips target).
5003 * DEC Alpha native support
5005 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5006 debug info, but GDB works fairly well with the DEC compiler and should
5007 work with a future GCC release. See the README file for a few
5008 Alpha-specific notes.
5010 * Preliminary thread implementation
5012 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5014 * LynxOS native and target support for 386
5016 This release has been hosted on LynxOS 2.2, and also can be configured
5017 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5020 * Improvements in C++ mangling/demangling.
5022 This release has much better g++ debugging, specifically in name
5023 mangling/demangling, virtual function calls, print virtual table,
5024 call methods, ...etc.
5026 *** Changes in GDB-4.10:
5028 * User visible changes:
5030 Remote debugging using the GDB-specific (`target remote') protocol now
5031 supports the `load' command. This is only useful if you have some
5032 other way of getting the stub to the target system, and you can put it
5033 somewhere in memory where it won't get clobbered by the download.
5035 Filename completion now works.
5037 When run under emacs mode, the "info line" command now causes the
5038 arrow to point to the line specified. Also, "info line" prints
5039 addresses in symbolic form (as well as hex).
5041 All vxworks based targets now support a user settable option, called
5042 vxworks-timeout. This option represents the number of seconds gdb
5043 should wait for responses to rpc's. You might want to use this if
5044 your vxworks target is, perhaps, a slow software simulator or happens
5045 to be on the far side of a thin network line.
5049 This release contains support for using a DEC alpha as a GDB host for
5050 cross debugging. Native alpha debugging is not supported yet.
5053 *** Changes in GDB-4.9:
5057 This is the first GDB release which is accompanied by a matching testsuite.
5058 The testsuite requires installation of dejagnu, which should be available
5059 via ftp from most sites that carry GNU software.
5063 'Cfront' style demangling has had its name changed to 'ARM' style, to
5064 emphasize that it was written from the specifications in the C++ Annotated
5065 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5066 disclaimers, it still generated too much confusion with users attempting to
5067 use gdb with AT&T cfront.
5071 GDB now uses a standard remote interface to a simulator library.
5072 So far, the library contains simulators for the Zilog Z8001/2, the
5073 Hitachi H8/300, H8/500 and Super-H.
5075 * New targets supported
5077 H8/300 simulator h8300-hitachi-hms or h8300hms
5078 H8/500 simulator h8500-hitachi-hms or h8500hms
5079 SH simulator sh-hitachi-hms or sh
5080 Z8000 simulator z8k-zilog-none or z8ksim
5081 IDT MIPS board over serial line mips-idt-ecoff
5083 Cross-debugging to GO32 targets is supported. It requires a custom
5084 version of the i386-stub.c module which is integrated with the
5085 GO32 memory extender.
5087 * New remote protocols
5089 MIPS remote debugging protocol.
5091 * New source languages supported
5093 This version includes preliminary support for Chill, a Pascal like language
5094 used by telecommunications companies. Chill support is also being integrated
5095 into the GNU compiler, but we don't know when it will be publically available.
5098 *** Changes in GDB-4.8:
5100 * HP Precision Architecture supported
5102 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5103 version of this support was available as a set of patches from the
5104 University of Utah. GDB does not support debugging of programs
5105 compiled with the HP compiler, because HP will not document their file
5106 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5107 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5109 Many problems in the preliminary version have been fixed.
5111 * Faster and better demangling
5113 We have improved template demangling and fixed numerous bugs in the GNU style
5114 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5115 character types (wchar_t) are now supported. Demangling of each symbol is now
5116 only done once, and is cached when the symbol table for a file is read in.
5117 This results in a small increase in memory usage for C programs, a moderate
5118 increase in memory usage for C++ programs, and a fantastic speedup in
5121 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5122 from the specifications in the Annotated Reference Manual, which AT&T's
5123 compiler does not actually implement.
5125 * G++ multiple inheritance compiler problem
5127 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5128 inheritance lattices was reworked to properly discover ambiguities. We
5129 recently found an example which causes this new algorithm to fail in a
5130 very subtle way, producing bad debug information for those classes.
5131 The file 'gcc.patch' (in this directory) can be applied to gcc to
5132 circumvent the problem. A future GCC release will contain a complete
5135 The previous G++ debug info problem (mentioned below for the gdb-4.7
5136 release) is fixed in gcc version 2.3.2.
5138 * Improved configure script
5140 The `configure' script will now attempt to guess your system type if
5141 you don't supply a host system type. The old scheme of supplying a
5142 host system triplet is preferable over using this. All the magic is
5143 done in the new `config.guess' script. Examine it for details.
5145 We have also brought our configure script much more in line with the FSF's
5146 version. It now supports the --with-xxx options. In particular,
5147 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5148 The resulting GDB will not be able to read arbitrary object file formats --
5149 only the format ``expected'' to be used on the configured target system.
5150 We hope to make this the default in a future release.
5152 * Documentation improvements
5154 There's new internal documentation on how to modify GDB, and how to
5155 produce clean changes to the code. We implore people to read it
5156 before submitting changes.
5158 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5159 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5160 `info' files are also provided. To build `info' files from scratch,
5161 you will need the latest `makeinfo' release, which will be available in
5162 a future texinfo-X.Y release.
5164 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5165 We're not sure exactly which versions have this problem, but it has
5166 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5167 or better. If that isn't possible, there is a patch in
5168 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5169 around this problem.
5173 GDB now supports array constants that can be used in expressions typed in by
5174 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5175 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5178 The new directory `gdb/sparclite' contains a program that demonstrates
5179 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5181 * New native hosts supported
5183 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5184 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5186 * New targets supported
5188 AMD 29k family via UDI a29k-amd-udi or udi29k
5190 * New file formats supported
5192 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5193 HPUX core files, and SCO 3.2v2 core files.
5197 Attaching to processes now works again; thanks for the many bug reports.
5199 We have also stomped on a bunch of core dumps caused by
5200 printf_filtered("%s") problems.
5202 We eliminated a copyright problem on the rpc and ptrace header files
5203 for VxWorks, which was discovered at the last minute during the 4.7
5204 release. You should now be able to build a VxWorks GDB.
5206 You can now interrupt gdb while an attached process is running. This
5207 will cause the attached process to stop, and give control back to GDB.
5209 We fixed problems caused by using too many file descriptors
5210 for reading symbols from object files and libraries. This was
5211 especially a problem for programs that used many (~100) shared
5214 The `step' command now only enters a subroutine if there is line number
5215 information for the subroutine. Otherwise it acts like the `next'
5216 command. Previously, `step' would enter subroutines if there was
5217 any debugging information about the routine. This avoids problems
5218 when using `cc -g1' on MIPS machines.
5220 * Internal improvements
5222 GDB's internal interfaces have been improved to make it easier to support
5223 debugging of multiple languages in the future.
5225 GDB now uses a common structure for symbol information internally.
5226 Minimal symbols (derived from linkage symbols in object files), partial
5227 symbols (from a quick scan of debug information), and full symbols
5228 contain a common subset of information, making it easier to write
5229 shared code that handles any of them.
5231 * New command line options
5233 We now accept --silent as an alias for --quiet.
5237 The memory-mapped-malloc library is now licensed under the GNU Library
5238 General Public License.
5240 *** Changes in GDB-4.7:
5242 * Host/native/target split
5244 GDB has had some major internal surgery to untangle the support for
5245 hosts and remote targets. Now, when you configure GDB for a remote
5246 target, it will no longer load in all of the support for debugging
5247 local programs on the host. When fully completed and tested, this will
5248 ensure that arbitrary host/target combinations are possible.
5250 The primary conceptual shift is to separate the non-portable code in
5251 GDB into three categories. Host specific code is required any time GDB
5252 is compiled on that host, regardless of the target. Target specific
5253 code relates to the peculiarities of the target, but can be compiled on
5254 any host. Native specific code is everything else: it can only be
5255 built when the host and target are the same system. Child process
5256 handling and core file support are two common `native' examples.
5258 GDB's use of /proc for controlling Unix child processes is now cleaner.
5259 It has been split out into a single module under the `target_ops' vector,
5260 plus two native-dependent functions for each system that uses /proc.
5262 * New hosts supported
5264 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5265 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5266 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5268 * New targets supported
5270 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5271 68030 and CPU32 m68030-*-*, m68332-*-*
5273 * New native hosts supported
5275 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5276 (386bsd is not well tested yet)
5277 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5279 * New file formats supported
5281 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5282 supports reading of `a.out.adobe' object files, which are an a.out
5283 format extended with minimal information about multiple sections.
5287 `show copying' is the same as the old `info copying'.
5288 `show warranty' is the same as `info warrantee'.
5289 These were renamed for consistency. The old commands continue to work.
5291 `info handle' is a new alias for `info signals'.
5293 You can now define pre-command hooks, which attach arbitrary command
5294 scripts to any command. The commands in the hook will be executed
5295 prior to the user's command. You can also create a hook which will be
5296 executed whenever the program stops. See gdb.texinfo.
5300 We now deal with Cfront style name mangling, and can even extract type
5301 info from mangled symbols. GDB can automatically figure out which
5302 symbol mangling style your C++ compiler uses.
5304 Calling of methods and virtual functions has been improved as well.
5308 The crash that occured when debugging Sun Ansi-C compiled binaries is
5309 fixed. This was due to mishandling of the extra N_SO stabs output
5312 We also finally got Ultrix 4.2 running in house, and fixed core file
5313 support, with help from a dozen people on the net.
5315 John M. Farrell discovered that the reason that single-stepping was so
5316 slow on all of the Mips based platforms (primarily SGI and DEC) was
5317 that we were trying to demangle and lookup a symbol used for internal
5318 purposes on every instruction that was being stepped through. Changing
5319 the name of that symbol so that it couldn't be mistaken for a C++
5320 mangled symbol sped things up a great deal.
5322 Rich Pixley sped up symbol lookups in general by getting much smarter
5323 about when C++ symbol mangling is necessary. This should make symbol
5324 completion (TAB on the command line) much faster. It's not as fast as
5325 we'd like, but it's significantly faster than gdb-4.6.
5329 A new user controllable variable 'call_scratch_address' can
5330 specify the location of a scratch area to be used when GDB
5331 calls a function in the target. This is necessary because the
5332 usual method of putting the scratch area on the stack does not work
5333 in systems that have separate instruction and data spaces.
5335 We integrated changes to support the 29k UDI (Universal Debugger
5336 Interface), but discovered at the last minute that we didn't have all
5337 of the appropriate copyright paperwork. We are working with AMD to
5338 resolve this, and hope to have it available soon.
5342 We have sped up the remote serial line protocol, especially for targets
5343 with lots of registers. It now supports a new `expedited status' ('T')
5344 message which can be used in place of the existing 'S' status message.
5345 This allows the remote stub to send only the registers that GDB
5346 needs to make a quick decision about single-stepping or conditional
5347 breakpoints, eliminating the need to fetch the entire register set for
5348 each instruction being stepped through.
5350 The GDB remote serial protocol now implements a write-through cache for
5351 registers, only re-reading the registers if the target has run.
5353 There is also a new remote serial stub for SPARC processors. You can
5354 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5355 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5356 processor with a serial port.
5360 Configure.in files have become much easier to read and modify. A new
5361 `table driven' format makes it more obvious what configurations are
5362 supported, and what files each one uses.
5366 There is a new opcodes library which will eventually contain all of the
5367 disassembly routines and opcode tables. At present, it only contains
5368 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5369 disassembler (binutils/objdump) to share these routines.
5371 The libiberty library is now copylefted under the GNU Library General
5372 Public License. This allows more liberal use, and was done so libg++
5373 can use it. This makes no difference to GDB, since the Library License
5374 grants all the rights from the General Public License.
5378 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5379 reference to the stabs symbol info used by the debugger. It is (as far
5380 as we know) the only published document on this fascinating topic. We
5381 encourage you to read it, compare it to the stabs information on your
5382 system, and send improvements on the document in general (to
5383 bug-gdb@prep.ai.mit.edu).
5385 And, of course, many bugs have been fixed.
5388 *** Changes in GDB-4.6:
5390 * Better support for C++ function names
5392 GDB now accepts as input the "demangled form" of C++ overloaded function
5393 names and member function names, and can do command completion on such names
5394 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5395 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5396 Make use of command completion, it is your friend.
5398 GDB also now accepts a variety of C++ mangled symbol formats. They are
5399 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5400 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5401 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5402 for the list of formats.
5404 * G++ symbol mangling problem
5406 Recent versions of gcc have a bug in how they emit debugging information for
5407 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5408 directory) can be applied to gcc to fix the problem. Alternatively, if you
5409 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5410 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5411 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5414 * New 'maintenance' command
5416 All of the commands related to hacking GDB internals have been moved out of
5417 the main command set, and now live behind the 'maintenance' command. This
5418 can also be abbreviated as 'mt'. The following changes were made:
5420 dump-me -> maintenance dump-me
5421 info all-breakpoints -> maintenance info breakpoints
5422 printmsyms -> maintenance print msyms
5423 printobjfiles -> maintenance print objfiles
5424 printpsyms -> maintenance print psymbols
5425 printsyms -> maintenance print symbols
5427 The following commands are new:
5429 maintenance demangle Call internal GDB demangler routine to
5430 demangle a C++ link name and prints the result.
5431 maintenance print type Print a type chain for a given symbol
5433 * Change to .gdbinit file processing
5435 We now read the $HOME/.gdbinit file before processing the argv arguments
5436 (e.g. reading symbol files or core files). This allows global parameters to
5437 be set, which will apply during the symbol reading. The ./.gdbinit is still
5438 read after argv processing.
5440 * New hosts supported
5442 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5444 GNU/Linux support i386-unknown-linux or linux
5446 We are also including code to support the HP/PA running BSD and HPUX. This
5447 is almost guaranteed not to work, as we didn't have time to test or build it
5448 for this release. We are including it so that the more adventurous (or
5449 masochistic) of you can play with it. We also had major problems with the
5450 fact that the compiler that we got from HP doesn't support the -g option.
5453 * New targets supported
5455 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5457 * More smarts about finding #include files
5459 GDB now remembers the compilation directory for all include files, and for
5460 all files from which C is generated (like yacc and lex sources). This
5461 greatly improves GDB's ability to find yacc/lex sources, and include files,
5462 especially if you are debugging your program from a directory different from
5463 the one that contains your sources.
5465 We also fixed a bug which caused difficulty with listing and setting
5466 breakpoints in include files which contain C code. (In the past, you had to
5467 try twice in order to list an include file that you hadn't looked at before.)
5469 * Interesting infernals change
5471 GDB now deals with arbitrary numbers of sections, where the symbols for each
5472 section must be relocated relative to that section's landing place in the
5473 target's address space. This work was needed to support ELF with embedded
5474 stabs used by Solaris-2.0.
5476 * Bug fixes (of course!)
5478 There have been loads of fixes for the following things:
5479 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5480 i960, stabs, DOS(GO32), procfs, etc...
5482 See the ChangeLog for details.
5484 *** Changes in GDB-4.5:
5486 * New machines supported (host and target)
5488 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5490 SGI Irix-4.x mips-sgi-irix4 or iris4
5492 * New malloc package
5494 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5495 Mmalloc is capable of handling mutiple heaps of memory. It is also
5496 capable of saving a heap to a file, and then mapping it back in later.
5497 This can be used to greatly speedup the startup of GDB by using a
5498 pre-parsed symbol table which lives in a mmalloc managed heap. For
5499 more details, please read mmalloc/mmalloc.texi.
5503 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5504 'help info proc' for details.
5506 * MIPS ecoff symbol table format
5508 The code that reads MIPS symbol table format is now supported on all hosts.
5509 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5512 * File name changes for MS-DOS
5514 Many files in the config directories have been renamed to make it easier to
5515 support GDB on MS-DOSe systems (which have very restrictive file name
5516 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5517 environment) is close to working but has some remaining problems. Note
5518 that debugging of DOS programs is not supported, due to limitations
5519 in the ``operating system'', but it can be used to host cross-debugging.
5521 * Cross byte order fixes
5523 Many fixes have been made to support cross debugging of Sparc and MIPS
5524 targets from hosts whose byte order differs.
5526 * New -mapped and -readnow options
5528 If memory-mapped files are available on your system through the 'mmap'
5529 system call, you can use the -mapped option on the `file' or
5530 `symbol-file' commands to cause GDB to write the symbols from your
5531 program into a reusable file. If the program you are debugging is
5532 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5533 Future GDB debugging sessions will notice the presence of this file,
5534 and will quickly map in symbol information from it, rather than reading
5535 the symbol table from the executable program. Using the '-mapped'
5536 option in a GDB `file' or `symbol-file' command has the same effect as
5537 starting GDB with the '-mapped' command-line option.
5539 You can cause GDB to read the entire symbol table immediately by using
5540 the '-readnow' option with any of the commands that load symbol table
5541 information (or on the GDB command line). This makes the command
5542 slower, but makes future operations faster.
5544 The -mapped and -readnow options are typically combined in order to
5545 build a `fred.syms' file that contains complete symbol information.
5546 A simple GDB invocation to do nothing but build a `.syms' file for future
5549 gdb -batch -nx -mapped -readnow programname
5551 The `.syms' file is specific to the host machine on which GDB is run.
5552 It holds an exact image of GDB's internal symbol table. It cannot be
5553 shared across multiple host platforms.
5555 * longjmp() handling
5557 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5558 siglongjmp() without losing control. This feature has not yet been ported to
5559 all systems. It currently works on many 386 platforms, all MIPS-based
5560 platforms (SGI, DECstation, etc), and Sun3/4.
5564 Preliminary work has been put in to support the new Solaris OS from Sun. At
5565 this time, it can control and debug processes, but it is not capable of
5570 As always, many many bug fixes. The major areas were with g++, and mipsread.
5571 People using the MIPS-based platforms should experience fewer mysterious
5572 crashes and trashed symbol tables.
5574 *** Changes in GDB-4.4:
5576 * New machines supported (host and target)
5578 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5580 BSD Reno on Vax vax-dec-bsd
5581 Ultrix on Vax vax-dec-ultrix
5583 * New machines supported (target)
5585 AMD 29000 embedded, using EBMON a29k-none-none
5589 GDB continues to improve its handling of C++. `References' work better.
5590 The demangler has also been improved, and now deals with symbols mangled as
5591 per the Annotated C++ Reference Guide.
5593 GDB also now handles `stabs' symbol information embedded in MIPS
5594 `ecoff' symbol tables. Since the ecoff format was not easily
5595 extensible to handle new languages such as C++, this appeared to be a
5596 good way to put C++ debugging info into MIPS binaries. This option
5597 will be supported in the GNU C compiler, version 2, when it is
5600 * New features for SVR4
5602 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5603 shared libraries. Debugging dynamically linked programs should present
5604 only minor differences from debugging statically linked programs.
5606 The `info proc' command will print out information about any process
5607 on an SVR4 system (including the one you are debugging). At the moment,
5608 it prints the address mappings of the process.
5610 If you bring up GDB on another SVR4 system, please send mail to
5611 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5613 * Better dynamic linking support in SunOS
5615 Reading symbols from shared libraries which contain debugging symbols
5616 now works properly. However, there remain issues such as automatic
5617 skipping of `transfer vector' code during function calls, which
5618 make it harder to debug code in a shared library, than to debug the
5619 same code linked statically.
5623 GDB is now using the latest `getopt' routines from the FSF. This
5624 version accepts the -- prefix for options with long names. GDB will
5625 continue to accept the old forms (-option and +option) as well.
5626 Various single letter abbreviations for options have been explicity
5627 added to the option table so that they won't get overshadowed in the
5628 future by other options that begin with the same letter.
5632 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5633 Many assorted bugs have been handled. Many more remain to be handled.
5634 See the various ChangeLog files (primarily in gdb and bfd) for details.
5637 *** Changes in GDB-4.3:
5639 * New machines supported (host and target)
5641 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5642 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5643 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5645 * Almost SCO Unix support
5647 We had hoped to support:
5648 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5649 (except for core file support), but we discovered very late in the release
5650 that it has problems with process groups that render gdb unusable. Sorry
5651 about that. I encourage people to fix it and post the fixes.
5653 * Preliminary ELF and DWARF support
5655 GDB can read ELF object files on System V Release 4, and can handle
5656 debugging records for C, in DWARF format, in ELF files. This support
5657 is preliminary. If you bring up GDB on another SVR4 system, please
5658 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5663 GDB now uses the latest `readline' library. One user-visible change
5664 is that two tabs will list possible command completions, which previously
5665 required typing M-? (meta-question mark, or ESC ?).
5669 The `stepi' bug that many of you noticed has been squashed.
5670 Many bugs in C++ have been handled. Many more remain to be handled.
5671 See the various ChangeLog files (primarily in gdb and bfd) for details.
5673 * State of the MIPS world (in case you wondered):
5675 GDB can understand the symbol tables emitted by the compilers
5676 supplied by most vendors of MIPS-based machines, including DEC. These
5677 symbol tables are in a format that essentially nobody else uses.
5679 Some versions of gcc come with an assembler post-processor called
5680 mips-tfile. This program is required if you want to do source-level
5681 debugging of gcc-compiled programs. I believe FSF does not ship
5682 mips-tfile with gcc version 1, but it will eventually come with gcc
5685 Debugging of g++ output remains a problem. g++ version 1.xx does not
5686 really support it at all. (If you're lucky, you should be able to get
5687 line numbers and stack traces to work, but no parameters or local
5688 variables.) With some work it should be possible to improve the
5691 When gcc version 2 is released, you will have somewhat better luck.
5692 However, even then you will get confusing results for inheritance and
5695 We will eventually provide full debugging of g++ output on
5696 DECstations. This will probably involve some kind of stabs-in-ecoff
5697 encapulation, but the details have not been worked out yet.
5700 *** Changes in GDB-4.2:
5702 * Improved configuration
5704 Only one copy of `configure' exists now, and it is not self-modifying.
5705 Porting BFD is simpler.
5709 The `step' and `next' commands now only stop at the first instruction
5710 of a source line. This prevents the multiple stops that used to occur
5711 in switch statements, for-loops, etc. `Step' continues to stop if a
5712 function that has debugging information is called within the line.
5716 Lots of small bugs fixed. More remain.
5718 * New host supported (not target)
5720 Intel 386 PC clone running Mach i386-none-mach
5723 *** Changes in GDB-4.1:
5725 * Multiple source language support
5727 GDB now has internal scaffolding to handle several source languages.
5728 It determines the type of each source file from its filename extension,
5729 and will switch expression parsing and number formatting to match the
5730 language of the function in the currently selected stack frame.
5731 You can also specifically set the language to be used, with
5732 `set language c' or `set language modula-2'.
5736 GDB now has preliminary support for the GNU Modula-2 compiler,
5737 currently under development at the State University of New York at
5738 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5739 continue through the fall of 1991 and into 1992.
5741 Other Modula-2 compilers are currently not supported, and attempting to
5742 debug programs compiled with them will likely result in an error as the
5743 symbol table is read. Feel free to work on it, though!
5745 There are hooks in GDB for strict type checking and range checking,
5746 in the `Modula-2 philosophy', but they do not currently work.
5750 GDB can now write to executable and core files (e.g. patch
5751 a variable's value). You must turn this switch on, specify
5752 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5753 by assigning a new value to a variable. Modifications take
5756 * Automatic SunOS shared library reading
5758 When you run your program, GDB automatically determines where its
5759 shared libraries (if any) have been loaded, and reads their symbols.
5760 The `share' command is no longer needed. This also works when
5761 examining core files.
5765 You can specify the number of lines that the `list' command shows.
5768 * New machines supported (host and target)
5770 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5771 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5772 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5774 * New hosts supported (not targets)
5776 IBM RT/PC: romp-ibm-aix or rtpc
5778 * New targets supported (not hosts)
5780 AMD 29000 embedded with COFF a29k-none-coff
5781 AMD 29000 embedded with a.out a29k-none-aout
5782 Ultracomputer remote kernel debug a29k-nyu-kern
5784 * New remote interfaces
5790 *** Changes in GDB-4.0:
5794 Wide output is wrapped at good places to make the output more readable.
5796 Gdb now supports cross-debugging from a host machine of one type to a
5797 target machine of another type. Communication with the target system
5798 is over serial lines. The ``target'' command handles connecting to the
5799 remote system; the ``load'' command will download a program into the
5800 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5801 also supports debugging of realtime processes running under VxWorks,
5802 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5803 stub on the target system.
5805 New CPUs supported include the AMD 29000 and Intel 960.
5807 GDB now reads object files and symbol tables via a ``binary file''
5808 library, which allows a single copy of GDB to debug programs of multiple
5809 object file types such as a.out and coff.
5811 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5812 refcard.dvi and refcard.ps are available to format it).
5815 * Control-Variable user interface simplified
5817 All variables that control the operation of the debugger can be set
5818 by the ``set'' command, and displayed by the ``show'' command.
5820 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5821 ``Show prompt'' produces the response:
5822 Gdb's prompt is new-gdb=>.
5824 What follows are the NEW set commands. The command ``help set'' will
5825 print a complete list of old and new set commands. ``help set FOO''
5826 will give a longer description of the variable FOO. ``show'' will show
5827 all of the variable descriptions and their current settings.
5829 confirm on/off: Enables warning questions for operations that are
5830 hard to recover from, e.g. rerunning the program while
5831 it is already running. Default is ON.
5833 editing on/off: Enables EMACS style command line editing
5834 of input. Previous lines can be recalled with
5835 control-P, the current line can be edited with control-B,
5836 you can search for commands with control-R, etc.
5839 history filename NAME: NAME is where the gdb command history
5840 will be stored. The default is .gdb_history,
5841 or the value of the environment variable
5844 history size N: The size, in commands, of the command history. The
5845 default is 256, or the value of the environment variable
5848 history save on/off: If this value is set to ON, the history file will
5849 be saved after exiting gdb. If set to OFF, the
5850 file will not be saved. The default is OFF.
5852 history expansion on/off: If this value is set to ON, then csh-like
5853 history expansion will be performed on
5854 command line input. The default is OFF.
5856 radix N: Sets the default radix for input and output. It can be set
5857 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5858 in the current radix, so "set radix 10" is always a no-op.
5860 height N: This integer value is the number of lines on a page. Default
5861 is 24, the current `stty rows'' setting, or the ``li#''
5862 setting from the termcap entry matching the environment
5865 width N: This integer value is the number of characters on a line.
5866 Default is 80, the current `stty cols'' setting, or the ``co#''
5867 setting from the termcap entry matching the environment
5870 Note: ``set screensize'' is obsolete. Use ``set height'' and
5871 ``set width'' instead.
5873 print address on/off: Print memory addresses in various command displays,
5874 such as stack traces and structure values. Gdb looks
5875 more ``symbolic'' if you turn this off; it looks more
5876 ``machine level'' with it on. Default is ON.
5878 print array on/off: Prettyprint arrays. New convenient format! Default
5881 print demangle on/off: Print C++ symbols in "source" form if on,
5884 print asm-demangle on/off: Same, for assembler level printouts
5887 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5890 * Support for Epoch Environment.
5892 The epoch environment is a version of Emacs v18 with windowing. One
5893 new command, ``inspect'', is identical to ``print'', except that if you
5894 are running in the epoch environment, the value is printed in its own
5898 * Support for Shared Libraries
5900 GDB can now debug programs and core files that use SunOS shared libraries.
5901 Symbols from a shared library cannot be referenced
5902 before the shared library has been linked with the program (this
5903 happens after you type ``run'' and before the function main() is entered).
5904 At any time after this linking (including when examining core files
5905 from dynamically linked programs), gdb reads the symbols from each
5906 shared library when you type the ``sharedlibrary'' command.
5907 It can be abbreviated ``share''.
5909 sharedlibrary REGEXP: Load shared object library symbols for files
5910 matching a unix regular expression. No argument
5911 indicates to load symbols for all shared libraries.
5913 info sharedlibrary: Status of loaded shared libraries.
5918 A watchpoint stops execution of a program whenever the value of an
5919 expression changes. Checking for this slows down execution
5920 tremendously whenever you are in the scope of the expression, but is
5921 quite useful for catching tough ``bit-spreader'' or pointer misuse
5922 problems. Some machines such as the 386 have hardware for doing this
5923 more quickly, and future versions of gdb will use this hardware.
5925 watch EXP: Set a watchpoint (breakpoint) for an expression.
5927 info watchpoints: Information about your watchpoints.
5929 delete N: Deletes watchpoint number N (same as breakpoints).
5930 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5931 enable N: Re-enables watchpoint number N (same as breakpoints).
5934 * C++ multiple inheritance
5936 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5939 * C++ exception handling
5941 Gdb now supports limited C++ exception handling. Besides the existing
5942 ability to breakpoint on an exception handler, gdb can breakpoint on
5943 the raising of an exception (before the stack is peeled back to the
5946 catch FOO: If there is a FOO exception handler in the dynamic scope,
5947 set a breakpoint to catch exceptions which may be raised there.
5948 Multiple exceptions (``catch foo bar baz'') may be caught.
5950 info catch: Lists all exceptions which may be caught in the
5951 current stack frame.
5954 * Minor command changes
5956 The command ``call func (arg, arg, ...)'' now acts like the print
5957 command, except it does not print or save a value if the function's result
5958 is void. This is similar to dbx usage.
5960 The ``up'' and ``down'' commands now always print the frame they end up
5961 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5962 frames without printing.
5964 * New directory command
5966 'dir' now adds directories to the FRONT of the source search path.
5967 The path starts off empty. Source files that contain debug information
5968 about the directory in which they were compiled can be found even
5969 with an empty path; Sun CC and GCC include this information. If GDB can't
5970 find your source file in the current directory, type "dir .".
5972 * Configuring GDB for compilation
5974 For normal use, type ``./configure host''. See README or gdb.texinfo
5977 GDB now handles cross debugging. If you are remotely debugging between
5978 two different machines, type ``./configure host -target=targ''.
5979 Host is the machine where GDB will run; targ is the machine
5980 where the program that you are debugging will run.