1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.9
6 * GDB has two new commands: "set serial parity odd|even|none" and
7 "show serial parity". These allows to set or show parity for the
10 * The "info source" command now displays the producer string if it was
11 present in the debug info. This typically includes the compiler version
12 and may include things like its command line arguments.
16 ** gdb.Objfile objects have a new attribute "username",
17 which is the name of the objfile as specified by the user,
18 without, for example, resolving symlinks.
22 maint print symbol-cache
23 Print the contents of the symbol cache.
25 maint print symbol-cache-statistics
26 Print statistics of symbol cache usage.
28 maint flush-symbol-cache
29 Flush the contents of the symbol cache.
33 Start branch trace recording using Branch Trace Store (BTS) format.
39 Set the maximum number of candidates to be considered during
40 completion. The default value is 200. This limit allows GDB
41 to avoid generating large completion lists, the computation of
42 which can cause the debugger to become temporarily unresponsive.
44 maint set symbol-cache-size
45 maint show symbol-cache-size
46 Control the size of the symbol cache.
48 set|show record btrace bts buffer-size
49 Set and show the size of the ring buffer used for branch tracing in
51 The obtained size may differ from the requested size. Use "info
52 record" to see the obtained buffer size.
54 * The command 'thread apply all' can now support new option '-ascending'
55 to call its specified command for all threads in ascending order.
57 * Python/Guile scripting
59 ** GDB now supports auto-loading of Python/Guile scripts contained in the
60 special section named `.debug_gdb_scripts'.
64 qXfer:btrace-conf:read
65 Return the branch trace configuration for the current thread.
68 Set the requested ring buffer size for branch tracing in BTS format.
71 Indicates a memory breakpoint instruction was executed, irrespective
72 of whether it was GDB that planted the breakpoint or the breakpoint
73 is hardcoded in the program. This is required for correct non-stop
77 Indicates the target stopped for a hardware breakpoint. This is
78 required for correct non-stop mode operation.
81 Return information about files on the remote system.
83 * The info record command now shows the recording format and the
84 branch tracing configuration for the current thread when using
85 the btrace record target.
86 For the BTS format, it shows the ring buffer size.
88 * GDB now has support for DTrace USDT (Userland Static Defined
89 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
91 * GDB now supports access to vector registers on S/390 GNU/Linux
94 * Removed targets and native configurations
96 HP/PA running HP-UX hppa*-*-hpux*
97 Itanium running HP-UX ia64-*-hpux*
99 *** Changes in GDB 7.9
101 * GDB now supports hardware watchpoints on x86 GNU Hurd.
105 ** You can now access frame registers from Python scripts.
106 ** New attribute 'producer' for gdb.Symtab objects.
107 ** gdb.Objfile objects have a new attribute "progspace",
108 which is the gdb.Progspace object of the containing program space.
109 ** gdb.Objfile objects have a new attribute "owner".
110 ** gdb.Objfile objects have a new attribute "build_id",
111 which is the build ID generated when the file was built.
112 ** gdb.Objfile objects have a new method "add_separate_debug_file".
113 ** A new event "gdb.clear_objfiles" has been added, triggered when
114 selecting a new file to debug.
115 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
116 ** New function gdb.lookup_objfile.
118 New events which are triggered when GDB modifies the state of the
121 ** gdb.events.inferior_call_pre: Function call is about to be made.
122 ** gdb.events.inferior_call_post: Function call has just been made.
123 ** gdb.events.memory_changed: A memory location has been altered.
124 ** gdb.events.register_changed: A register has been altered.
126 * New Python-based convenience functions:
128 ** $_caller_is(name [, number_of_frames])
129 ** $_caller_matches(regexp [, number_of_frames])
130 ** $_any_caller_is(name [, number_of_frames])
131 ** $_any_caller_matches(regexp [, number_of_frames])
133 * GDB now supports the compilation and injection of source code into
134 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
135 to compile the source code to object code, and if successful, inject
136 and execute that code within the current context of the inferior.
137 Currently the C language is supported. The commands used to
138 interface with this new feature are:
140 compile code [-raw|-r] [--] [source code]
141 compile file [-raw|-r] filename
145 demangle [-l language] [--] name
146 Demangle "name" in the specified language, or the current language
147 if elided. This command is renamed from the "maint demangle" command.
148 The latter is kept as a no-op to avoid "maint demangle" being interpreted
149 as "maint demangler-warning".
151 queue-signal signal-name-or-number
152 Queue a signal to be delivered to the thread when it is resumed.
154 add-auto-load-scripts-directory directory
155 Add entries to the list of directories from which to load auto-loaded
158 maint print user-registers
159 List all currently available "user" registers.
161 compile code [-r|-raw] [--] [source code]
162 Compile, inject, and execute in the inferior the executable object
163 code produced by compiling the provided source code.
165 compile file [-r|-raw] filename
166 Compile and inject into the inferior the executable object code
167 produced by compiling the source code stored in the filename
170 * On resume, GDB now always passes the signal the program had stopped
171 for to the thread the signal was sent to, even if the user changed
172 threads before resuming. Previously GDB would often (but not
173 always) deliver the signal to the thread that happens to be current
176 * Conversely, the "signal" command now consistently delivers the
177 requested signal to the current thread. GDB now asks for
178 confirmation if the program had stopped for a signal and the user
179 switched threads meanwhile.
181 * "breakpoint always-inserted" modes "off" and "auto" merged.
183 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
184 won't remove breakpoints from the target until all threads stop,
185 even in non-stop mode. The "auto" mode has been removed, and "off"
186 is now the default mode.
190 set debug symbol-lookup
191 show debug symbol-lookup
192 Control display of debugging info regarding symbol lookup.
196 ** The -list-thread-groups command outputs an exit-code field for
197 inferiors that have exited.
201 MIPS SDE mips*-sde*-elf*
205 Support for these obsolete configurations has been removed.
207 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
208 SGI Irix-5.x mips-*-irix5*
209 SGI Irix-6.x mips-*-irix6*
210 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
211 VAX running Ultrix vax-*-ultrix*
213 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
214 and "assf"), have been removed. Use the "sharedlibrary" command, or
215 its alias "share", instead.
217 *** Changes in GDB 7.8
219 * New command line options
222 This is an alias for the --data-directory option.
224 * GDB supports printing and modifying of variable length automatic arrays
225 as specified in ISO C99.
227 * The ARM simulator now supports instruction level tracing
228 with or without disassembly.
232 GDB now has support for scripting using Guile. Whether this is
233 available is determined at configure time.
234 Guile version 2.0 or greater is required.
235 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
237 * New commands (for set/show, see "New options" below)
241 Invoke CODE by passing it to the Guile interpreter.
245 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
247 info auto-load guile-scripts [regexp]
248 Print the list of automatically loaded Guile scripts.
250 * The source command is now capable of sourcing Guile scripts.
251 This feature is dependent on the debugger being built with Guile support.
255 set print symbol-loading (off|brief|full)
256 show print symbol-loading
257 Control whether to print informational messages when loading symbol
258 information for a file. The default is "full", but when debugging
259 programs with large numbers of shared libraries the amount of output
262 set guile print-stack (none|message|full)
263 show guile print-stack
264 Show a stack trace when an error is encountered in a Guile script.
266 set auto-load guile-scripts (on|off)
267 show auto-load guile-scripts
268 Control auto-loading of Guile script files.
270 maint ada set ignore-descriptive-types (on|off)
271 maint ada show ignore-descriptive-types
272 Control whether the debugger should ignore descriptive types in Ada
273 programs. The default is not to ignore the descriptive types. See
274 the user manual for more details on descriptive types and the intended
275 usage of this option.
277 set auto-connect-native-target
279 Control whether GDB is allowed to automatically connect to the
280 native target for the run, attach, etc. commands when not connected
281 to any target yet. See also "target native" below.
283 set record btrace replay-memory-access (read-only|read-write)
284 show record btrace replay-memory-access
285 Control what memory accesses are allowed during replay.
287 maint set target-async (on|off)
288 maint show target-async
289 This controls whether GDB targets operate in synchronous or
290 asynchronous mode. Normally the default is asynchronous, if it is
291 available; but this can be changed to more easily debug problems
292 occurring only in synchronous mode.
294 set mi-async (on|off)
296 Control whether MI asynchronous mode is preferred. This supersedes
297 "set target-async" of previous GDB versions.
299 * "set target-async" is deprecated as a CLI option and is now an alias
300 for "set mi-async" (only puts MI into async mode).
302 * Background execution commands (e.g., "c&", "s&", etc.) are now
303 possible ``out of the box'' if the target supports them. Previously
304 the user would need to explicitly enable the possibility with the
305 "set target-async on" command.
307 * New features in the GDB remote stub, GDBserver
309 ** New option --debug-format=option1[,option2,...] allows one to add
310 additional text to each output. At present only timestamps
311 are supported: --debug-format=timestamps.
312 Timestamps can also be turned on with the
313 "monitor set debug-format timestamps" command from GDB.
315 * The 'record instruction-history' command now starts counting instructions
316 at one. This also affects the instruction ranges reported by the
317 'record function-call-history' command when given the /i modifier.
319 * The command 'record function-call-history' supports a new modifier '/c' to
320 indent the function names based on their call stack depth.
321 The fields for the '/i' and '/l' modifier have been reordered.
322 The source line range is now prefixed with 'at'.
323 The instruction range is now prefixed with 'inst'.
324 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
325 "record instruction-history" and "list" commands.
327 * The ranges given as arguments to the 'record function-call-history' and
328 'record instruction-history' commands are now inclusive.
330 * The btrace record target now supports the 'record goto' command.
331 For locations inside the execution trace, the back trace is computed
332 based on the information stored in the execution trace.
334 * The btrace record target supports limited reverse execution and replay.
335 The target does not record data and therefore does not allow reading
338 * The "catch syscall" command now works on s390*-linux* targets.
340 * The "compare-sections" command is no longer specific to target
341 remote. It now works with all targets.
343 * All native targets are now consistently called "native".
344 Consequently, the "target child", "target GNU", "target djgpp",
345 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
346 commands have been replaced with "target native". The QNX/NTO port
347 leaves the "procfs" target in place and adds a "native" target for
348 consistency with other ports. The impact on users should be minimal
349 as these commands previously either throwed an error, or were
350 no-ops. The target's name is visible in the output of the following
351 commands: "help target", "info target", "info files", "maint print
354 * The "target native" command now connects to the native target. This
355 can be used to launch native programs even when "set
356 auto-connect-native-target" is set to off.
358 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.
360 * Support for Intel(R) AVX-512 registers on GNU/Linux.
361 Support displaying and modifying Intel(R) AVX-512 registers
362 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
366 qXfer:btrace:read's annex
367 The qXfer:btrace:read packet supports a new annex 'delta' to read
368 branch trace incrementally.
372 ** Valid Python operations on gdb.Value objects representing
373 structs/classes invoke the corresponding overloaded operators if
375 ** New `Xmethods' feature in the Python API. Xmethods are
376 additional methods or replacements for existing methods of a C++
377 class. This feature is useful for those cases where a method
378 defined in C++ source code could be inlined or optimized out by
379 the compiler, making it unavailable to GDB.
382 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
384 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
385 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
386 its alias "share", instead.
388 * The commands "set remotebaud" and "show remotebaud" are no longer
389 supported. Use "set serial baud" and "show serial baud" (respectively)
394 ** A new option "-gdb-set mi-async" replaces "-gdb-set
395 target-async". The latter is left as a deprecated alias of the
396 former for backward compatibility. If the target supports it,
397 CLI background execution commands are now always possible by
398 default, independently of whether the frontend stated a
399 preference for asynchronous execution with "-gdb-set mi-async".
400 Previously "-gdb-set target-async off" affected both MI execution
401 commands and CLI execution commands.
403 *** Changes in GDB 7.7
405 * Improved support for process record-replay and reverse debugging on
406 arm*-linux* targets. Support for thumb32 and syscall instruction
407 recording has been added.
409 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
411 * GDB now supports Fission DWP file format version 2.
412 http://gcc.gnu.org/wiki/DebugFission
414 * New convenience function "$_isvoid", to check whether an expression
415 is void. A void expression is an expression where the type of the
416 result is "void". For example, some convenience variables may be
417 "void" when evaluated (e.g., "$_exitcode" before the execution of
418 the program being debugged; or an undefined convenience variable).
419 Another example, when calling a function whose return type is
422 * The "maintenance print objfiles" command now takes an optional regexp.
424 * The "catch syscall" command now works on arm*-linux* targets.
426 * GDB now consistently shows "<not saved>" when printing values of
427 registers the debug info indicates have not been saved in the frame
428 and there's nowhere to retrieve them from
429 (callee-saved/call-clobbered registers):
434 (gdb) info registers rax
437 Before, the former would print "<optimized out>", and the latter
438 "*value not available*".
440 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
445 ** Frame filters and frame decorators have been added.
446 ** Temporary breakpoints are now supported.
447 ** Line tables representation has been added.
448 ** New attribute 'parent_type' for gdb.Field objects.
449 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
450 ** New attribute 'name' for gdb.Type objects.
454 Nios II ELF nios2*-*-elf
455 Nios II GNU/Linux nios2*-*-linux
456 Texas Instruments MSP430 msp430*-*-elf
458 * Removed native configurations
460 Support for these a.out NetBSD and OpenBSD obsolete configurations has
461 been removed. ELF variants of these configurations are kept supported.
463 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
464 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
465 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
466 i[34567]86-*-openbsd3.[0-3]
467 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
468 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
469 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
473 Like "catch throw", but catches a re-thrown exception.
475 Renamed from old "maint check-symtabs".
477 Perform consistency checks on symtabs.
479 Expand symtabs matching an optional regexp.
482 Display the details of GDB configure-time options.
484 maint set|show per-command
485 maint set|show per-command space
486 maint set|show per-command time
487 maint set|show per-command symtab
488 Enable display of per-command gdb resource usage.
490 remove-symbol-file FILENAME
491 remove-symbol-file -a ADDRESS
492 Remove a symbol file added via add-symbol-file. The file to remove
493 can be identified by its filename or by an address that lies within
494 the boundaries of this symbol file in memory.
497 info exceptions REGEXP
498 Display the list of Ada exceptions defined in the program being
499 debugged. If provided, only the exceptions whose names match REGEXP
504 set debug symfile off|on
506 Control display of debugging info regarding reading symbol files and
507 symbol tables within those files
509 set print raw frame-arguments
510 show print raw frame-arguments
511 Set/show whether to print frame arguments in raw mode,
512 disregarding any defined pretty-printers.
514 set remote trace-status-packet
515 show remote trace-status-packet
516 Set/show the use of remote protocol qTStatus packet.
520 Control display of debugging messages related to Nios II targets.
524 Control whether target-assisted range stepping is enabled.
526 set startup-with-shell
527 show startup-with-shell
528 Specifies whether Unix child processes are started via a shell or
533 Use the target memory cache for accesses to the code segment. This
534 improves performance of remote debugging (particularly disassembly).
536 * You can now use a literal value 'unlimited' for options that
537 interpret 0 or -1 as meaning "unlimited". E.g., "set
538 trace-buffer-size unlimited" is now an alias for "set
539 trace-buffer-size -1" and "set height unlimited" is now an alias for
542 * The "set debug symtab-create" debugging option of GDB has been changed to
543 accept a verbosity level. 0 means "off", 1 provides basic debugging
544 output, and values of 2 or greater provides more verbose output.
546 * New command-line options
548 Display the details of GDB configure-time options.
550 * The command 'tsave' can now support new option '-ctf' to save trace
551 buffer in Common Trace Format.
553 * Newly installed $prefix/bin/gcore acts as a shell interface for the
556 * GDB now implements the the C++ 'typeid' operator.
558 * The new convenience variable $_exception holds the exception being
559 thrown or caught at an exception-related catchpoint.
561 * The exception-related catchpoints, like "catch throw", now accept a
562 regular expression which can be used to filter exceptions by type.
564 * The new convenience variable $_exitsignal is automatically set to
565 the terminating signal number when the program being debugged dies
566 due to an uncaught signal.
570 ** All MI commands now accept an optional "--language" option.
571 Support for this feature can be verified by using the "-list-features"
572 command, which should contain "language-option".
574 ** The new command -info-gdb-mi-command allows the user to determine
575 whether a GDB/MI command is supported or not.
577 ** The "^error" result record returned when trying to execute an undefined
578 GDB/MI command now provides a variable named "code" whose content is the
579 "undefined-command" error code. Support for this feature can be verified
580 by using the "-list-features" command, which should contain
581 "undefined-command-error-code".
583 ** The -trace-save MI command can optionally save trace buffer in Common
586 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
588 ** The command -data-list-register-values now accepts an optional
589 "--skip-unavailable" option. When used, only the available registers
592 ** The new command -trace-frame-collected dumps collected variables,
593 computed expressions, tvars, memory and registers in a traceframe.
595 ** The commands -stack-list-locals, -stack-list-arguments and
596 -stack-list-variables now accept an option "--skip-unavailable".
597 When used, only the available locals or arguments are displayed.
599 ** The -exec-run command now accepts an optional "--start" option.
600 When used, the command follows the same semantics as the "start"
601 command, stopping the program's execution at the start of its
602 main subprogram. Support for this feature can be verified using
603 the "-list-features" command, which should contain
604 "exec-run-start-option".
606 ** The new commands -catch-assert and -catch-exceptions insert
607 catchpoints stopping the program when Ada exceptions are raised.
609 ** The new command -info-ada-exceptions provides the equivalent of
610 the new "info exceptions" command.
612 * New system-wide configuration scripts
613 A GDB installation now provides scripts suitable for use as system-wide
614 configuration scripts for the following systems:
618 * GDB now supports target-assigned range stepping with remote targets.
619 This improves the performance of stepping source lines by reducing
620 the number of control packets from/to GDB. See "New remote packets"
623 * GDB now understands the element 'tvar' in the XML traceframe info.
624 It has the id of the collected trace state variables.
626 * On S/390 targets that provide the transactional-execution feature,
627 the program interruption transaction diagnostic block (TDB) is now
628 represented as a number of additional "registers" in GDB.
634 The vCont packet supports a new 'r' action, that tells the remote
635 stub to step through an address range itself, without GDB
636 involvemement at each single-step.
638 qXfer:libraries-svr4:read's annex
639 The previously unused annex of the qXfer:libraries-svr4:read packet
640 is now used to support passing an argument list. The remote stub
641 reports support for this argument list to GDB's qSupported query.
642 The defined arguments are "start" and "prev", used to reduce work
643 necessary for library list updating, resulting in significant
646 * New features in the GDB remote stub, GDBserver
648 ** GDBserver now supports target-assisted range stepping. Currently
649 enabled on x86/x86_64 GNU/Linux targets.
651 ** GDBserver now adds element 'tvar' in the XML in the reply to
652 'qXfer:traceframe-info:read'. It has the id of the collected
653 trace state variables.
655 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
658 * New 'z' formatter for printing and examining memory, this displays the
659 value as hexadecimal zero padded on the left to the size of the type.
661 * GDB can now use Windows x64 unwinding data.
663 * The "set remotebaud" command has been replaced by "set serial baud".
664 Similarly, "show remotebaud" has been replaced by "show serial baud".
665 The "set remotebaud" and "show remotebaud" commands are still available
666 to provide backward compatibility with older versions of GDB.
668 *** Changes in GDB 7.6
670 * Target record has been renamed to record-full.
671 Record/replay is now enabled with the "record full" command.
672 This also affects settings that are associated with full record/replay
673 that have been moved from "set/show record" to "set/show record full":
675 set|show record full insn-number-max
676 set|show record full stop-at-limit
677 set|show record full memory-query
679 * A new record target "record-btrace" has been added. The new target
680 uses hardware support to record the control-flow of a process. It
681 does not support replaying the execution, but it implements the
682 below new commands for investigating the recorded execution log.
683 This new recording method can be enabled using:
687 The "record-btrace" target is only available on Intel Atom processors
688 and requires a Linux kernel 2.6.32 or later.
690 * Two new commands have been added for record/replay to give information
691 about the recorded execution without having to replay the execution.
692 The commands are only supported by "record btrace".
694 record instruction-history prints the execution history at
695 instruction granularity
697 record function-call-history prints the execution history at
700 * New native configurations
702 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
703 FreeBSD/powerpc powerpc*-*-freebsd
704 x86_64/Cygwin x86_64-*-cygwin*
705 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
709 ARM AArch64 aarch64*-*-elf
710 ARM AArch64 GNU/Linux aarch64*-*-linux
711 Lynx 178 PowerPC powerpc-*-lynx*178
712 x86_64/Cygwin x86_64-*-cygwin*
713 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
715 * If the configured location of system.gdbinit file (as given by the
716 --with-system-gdbinit option at configure time) is in the
717 data-directory (as specified by --with-gdb-datadir at configure
718 time) or in one of its subdirectories, then GDB will look for the
719 system-wide init file in the directory specified by the
720 --data-directory command-line option.
722 * New command line options:
724 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
725 other initialization files, unlike -nx which disables all of them.
727 * Removed command line options
729 -epoch This was used by the gdb mode in Epoch, an ancient fork of
732 * The 'ptype' and 'whatis' commands now accept an argument to control
735 * 'info proc' now works on some core files.
739 ** Vectors can be created with gdb.Type.vector.
741 ** Python's atexit.register now works in GDB.
743 ** Types can be pretty-printed via a Python API.
745 ** Python 3 is now supported (in addition to Python 2.4 or later)
747 ** New class gdb.Architecture exposes GDB's internal representation
748 of architecture in the Python API.
750 ** New method Frame.architecture returns the gdb.Architecture object
751 corresponding to the frame's architecture.
753 * New Python-based convenience functions:
755 ** $_memeq(buf1, buf2, length)
756 ** $_streq(str1, str2)
758 ** $_regex(str, regex)
760 * The 'cd' command now defaults to using '~' (the home directory) if not
763 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
764 default for GCC since November 2000.
766 * The command 'forward-search' can now be abbreviated as 'fo'.
768 * The command 'info tracepoints' can now display 'installed on target'
769 or 'not installed on target' for each non-pending location of tracepoint.
771 * New configure options
773 --enable-libmcheck/--disable-libmcheck
774 By default, development versions are built with -lmcheck on hosts
775 that support it, in order to help track memory corruption issues.
776 Release versions, on the other hand, are built without -lmcheck
777 by default. The --enable-libmcheck/--disable-libmcheck configure
778 options allow the user to override that default.
779 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
780 This configure option allows the user to build GDB with
781 libbabeltrace using which GDB can read Common Trace Format data.
783 * New commands (for set/show, see "New options" below)
786 Catch signals. This is similar to "handle", but allows commands and
787 conditions to be attached.
790 List the BFDs known to GDB.
792 python-interactive [command]
794 Start a Python interactive prompt, or evaluate the optional command
795 and print the result of expressions.
798 "py" is a new alias for "python".
800 enable type-printer [name]...
801 disable type-printer [name]...
802 Enable or disable type printers.
806 ** For the Renesas Super-H architecture, the "regs" command has been removed
807 (has been deprecated in GDB 7.5), and "info all-registers" should be used
812 set print type methods (on|off)
813 show print type methods
814 Control whether method declarations are displayed by "ptype".
815 The default is to show them.
817 set print type typedefs (on|off)
818 show print type typedefs
819 Control whether typedef definitions are displayed by "ptype".
820 The default is to show them.
822 set filename-display basename|relative|absolute
823 show filename-display
824 Control the way in which filenames is displayed.
825 The default is "relative", which preserves previous behavior.
827 set trace-buffer-size
828 show trace-buffer-size
829 Request target to change the size of trace buffer.
831 set remote trace-buffer-size-packet auto|on|off
832 show remote trace-buffer-size-packet
833 Control the use of the remote protocol `QTBuffer:size' packet.
837 Control display of debugging messages related to ARM AArch64.
840 set debug coff-pe-read
841 show debug coff-pe-read
842 Control display of debugging messages related to reading of COFF/PE
847 Control display of debugging messages related to Mach-O symbols
850 set debug notification
851 show debug notification
852 Control display of debugging info for async remote notification.
856 ** Command parameter changes are now notified using new async record
857 "=cmd-param-changed".
858 ** Trace frame changes caused by command "tfind" are now notified using
859 new async record "=traceframe-changed".
860 ** The creation, deletion and modification of trace state variables
861 are now notified using new async records "=tsv-created",
862 "=tsv-deleted" and "=tsv-modified".
863 ** The start and stop of process record are now notified using new
864 async record "=record-started" and "=record-stopped".
865 ** Memory changes are now notified using new async record
867 ** The data-disassemble command response will include a "fullname" field
868 containing the absolute file name when source has been requested.
869 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
870 command, to allow pattern filling of memory areas.
871 ** New commands "-catch-load"/"-catch-unload" added for intercepting
872 library load/unload events.
873 ** The response to breakpoint commands and breakpoint async records
874 includes an "installed" field containing a boolean state about each
875 non-pending tracepoint location is whether installed on target or not.
876 ** Output of the "-trace-status" command includes a "trace-file" field
877 containing the name of the trace file being examined. This field is
878 optional, and only present when examining a trace file.
879 ** The "fullname" field is now always present along with the "file" field,
880 even if the file cannot be found by GDB.
882 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
883 You must have the LZMA library available when configuring GDB for this
884 feature to be enabled. For more information, see:
885 http://fedoraproject.org/wiki/Features/MiniDebugInfo
890 Set the size of trace buffer. The remote stub reports support for this
891 packet to gdb's qSupported query.
894 Enable Branch Trace Store (BTS)-based branch tracing for the current
895 thread. The remote stub reports support for this packet to gdb's
899 Disable branch tracing for the current thread. The remote stub reports
900 support for this packet to gdb's qSupported query.
903 Read the traced branches for the current thread. The remote stub
904 reports support for this packet to gdb's qSupported query.
906 *** Changes in GDB 7.5
908 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
909 for more x32 ABI info.
911 * GDB now supports access to MIPS DSP registers on Linux targets.
913 * GDB now supports debugging microMIPS binaries.
915 * The "info os" command on GNU/Linux can now display information on
916 several new classes of objects managed by the operating system:
917 "info os procgroups" lists process groups
918 "info os files" lists file descriptors
919 "info os sockets" lists internet-domain sockets
920 "info os shm" lists shared-memory regions
921 "info os semaphores" lists semaphores
922 "info os msg" lists message queues
923 "info os modules" lists loaded kernel modules
925 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
926 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
927 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
928 options and inspect the probe arguments using the new $_probe_arg family
929 of convenience variables. You can obtain more information about SystemTap
930 in <http://sourceware.org/systemtap/>.
932 * GDB now supports reversible debugging on ARM, it allows you to
933 debug basic ARM and THUMB instructions, and provides
934 record/replay support.
936 * The option "symbol-reloading" has been deleted as it is no longer used.
940 ** GDB commands implemented in Python can now be put in command class
943 ** The "maint set python print-stack on|off" is now deleted.
945 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
946 apply "flag enum"-style pretty-printing to any enum.
948 ** gdb.lookup_symbol can now work when there is no current frame.
950 ** gdb.Symbol now has a 'line' attribute, holding the line number in
951 the source at which the symbol was defined.
953 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
954 method 'value'. The former indicates whether the symbol needs a
955 frame in order to compute its value, and the latter computes the
958 ** A new method 'referenced_value' on gdb.Value objects which can
959 dereference pointer as well as C++ reference values.
961 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
962 which return the global and static blocks (as gdb.Block objects),
963 of the underlying symbol table, respectively.
965 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
966 object associated with a PC value.
968 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
969 of the address range occupied by code for the current source line.
971 * Go language support.
972 GDB now supports debugging programs written in the Go programming
975 * GDBserver now supports stdio connections.
976 E.g. (gdb) target remote | ssh myhost gdbserver - hello
978 * The binary "gdbtui" can no longer be built or installed.
979 Use "gdb -tui" instead.
981 * GDB will now print "flag" enums specially. A flag enum is one where
982 all the enumerator values have no bits in common when pairwise
983 "and"ed. When printing a value whose type is a flag enum, GDB will
984 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
985 (gdb) print (enum E) 3
988 * The filename part of a linespec will now match trailing components
989 of a source file name. For example, "break gcc/expr.c:1000" will
990 now set a breakpoint in build/gcc/expr.c, but not
993 * The "info proc" and "generate-core-file" commands will now also
994 work on remote targets connected to GDBserver on Linux.
996 * The command "info catch" has been removed. It has been disabled
999 * The "catch exception" and "catch assert" commands now accept
1000 a condition at the end of the command, much like the "break"
1001 command does. For instance:
1003 (gdb) catch exception Constraint_Error if Barrier = True
1005 Previously, it was possible to add a condition to such catchpoints,
1006 but it had to be done as a second step, after the catchpoint had been
1007 created, using the "condition" command.
1009 * The "info static-tracepoint-marker" command will now also work on
1010 native Linux targets with in-process agent.
1012 * GDB can now set breakpoints on inlined functions.
1014 * The .gdb_index section has been updated to include symbols for
1015 inlined functions. GDB will ignore older .gdb_index sections by
1016 default, which could cause symbol files to be loaded more slowly
1017 until their .gdb_index sections can be recreated. The new command
1018 "set use-deprecated-index-sections on" will cause GDB to use any older
1019 .gdb_index sections it finds. This will restore performance, but the
1020 ability to set breakpoints on inlined functions will be lost in symbol
1021 files with older .gdb_index sections.
1023 The .gdb_index section has also been updated to record more information
1024 about each symbol. This speeds up the "info variables", "info functions"
1025 and "info types" commands when used with programs having the .gdb_index
1026 section, as well as speeding up debugging with shared libraries using
1027 the .gdb_index section.
1029 * Ada support for GDB/MI Variable Objects has been added.
1031 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1036 ** New command -info-os is the MI equivalent of "info os".
1038 ** Output logs ("set logging" and related) now include MI output.
1042 ** "set use-deprecated-index-sections on|off"
1043 "show use-deprecated-index-sections on|off"
1044 Controls the use of deprecated .gdb_index sections.
1046 ** "catch load" and "catch unload" can be used to stop when a shared
1047 library is loaded or unloaded, respectively.
1049 ** "enable count" can be used to auto-disable a breakpoint after
1052 ** "info vtbl" can be used to show the virtual method tables for
1053 C++ and Java objects.
1055 ** "explore" and its sub commands "explore value" and "explore type"
1056 can be used to recursively explore values and types of
1057 expressions. These commands are available only if GDB is
1058 configured with '--with-python'.
1060 ** "info auto-load" shows status of all kinds of auto-loaded files,
1061 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1062 sequences of commands files, "info auto-load python-scripts"
1063 shows status of auto-loading Python script files,
1064 "info auto-load local-gdbinit" shows status of loading init file
1065 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1066 status of inferior specific thread debugging shared library loading.
1068 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1069 and "show auto-load-scripts" commands have been deprecated, use their
1070 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1071 and "show auto-load python-scripts" counterparts instead.
1073 ** "dprintf location,format,args..." creates a dynamic printf, which
1074 is basically a breakpoint that does a printf and immediately
1075 resumes your program's execution, so it is like a printf that you
1076 can insert dynamically at runtime instead of at compiletime.
1078 ** "set print symbol"
1080 Controls whether GDB attempts to display the symbol, if any,
1081 corresponding to addresses it prints. This defaults to "on", but
1082 you can set it to "off" to restore GDB's previous behavior.
1084 * Deprecated commands
1086 ** For the Renesas Super-H architecture, the "regs" command has been
1087 deprecated, and "info all-registers" should be used instead.
1091 Renesas RL78 rl78-*-elf
1092 HP OpenVMS ia64 ia64-hp-openvms*
1094 * GDBserver supports evaluation of breakpoint conditions. When
1095 support is advertised by GDBserver, GDB may be told to send the
1096 breakpoint conditions in bytecode form to GDBserver. GDBserver
1097 will only report the breakpoint trigger to GDB when its condition
1102 set mips compression
1103 show mips compression
1104 Select the compressed ISA encoding used in functions that have no symbol
1105 information available. The encoding can be set to either of:
1108 and is updated automatically from ELF file flags if available.
1110 set breakpoint condition-evaluation
1111 show breakpoint condition-evaluation
1112 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1113 GDBserver ("target"). Default option "auto" chooses the most efficient
1115 This option can improve debugger efficiency depending on the speed of the
1119 Disable auto-loading globally.
1122 Show auto-loading setting of all kinds of auto-loaded files.
1124 set auto-load gdb-scripts on|off
1125 show auto-load gdb-scripts
1126 Control auto-loading of GDB canned sequences of commands files.
1128 set auto-load python-scripts on|off
1129 show auto-load python-scripts
1130 Control auto-loading of Python script files.
1132 set auto-load local-gdbinit on|off
1133 show auto-load local-gdbinit
1134 Control loading of init file (.gdbinit) from current directory.
1136 set auto-load libthread-db on|off
1137 show auto-load libthread-db
1138 Control auto-loading of inferior specific thread debugging shared library.
1140 set auto-load scripts-directory <dir1>[:<dir2>...]
1141 show auto-load scripts-directory
1142 Set a list of directories from which to load auto-loaded scripts.
1143 Automatically loaded Python scripts and GDB scripts are located in one
1144 of the directories listed by this option.
1145 The delimiter (':' above) may differ according to the host platform.
1147 set auto-load safe-path <dir1>[:<dir2>...]
1148 show auto-load safe-path
1149 Set a list of directories from which it is safe to auto-load files.
1150 The delimiter (':' above) may differ according to the host platform.
1152 set debug auto-load on|off
1153 show debug auto-load
1154 Control display of debugging info for auto-loading the files above.
1156 set dprintf-style gdb|call|agent
1158 Control the way in which a dynamic printf is performed; "gdb"
1159 requests a GDB printf command, while "call" causes dprintf to call a
1160 function in the inferior. "agent" requests that the target agent
1161 (such as GDBserver) do the printing.
1163 set dprintf-function <expr>
1164 show dprintf-function
1165 set dprintf-channel <expr>
1166 show dprintf-channel
1167 Set the function and optional first argument to the call when using
1168 the "call" style of dynamic printf.
1170 set disconnected-dprintf on|off
1171 show disconnected-dprintf
1172 Control whether agent-style dynamic printfs continue to be in effect
1173 after GDB disconnects.
1175 * New configure options
1177 --with-auto-load-dir
1178 Configure default value for the 'set auto-load scripts-directory'
1179 setting above. It defaults to '$debugdir:$datadir/auto-load',
1180 $debugdir representing global debugging info directories (available
1181 via 'show debug-file-directory') and $datadir representing GDB's data
1182 directory (available via 'show data-directory').
1184 --with-auto-load-safe-path
1185 Configure default value for the 'set auto-load safe-path' setting
1186 above. It defaults to the --with-auto-load-dir setting.
1188 --without-auto-load-safe-path
1189 Set 'set auto-load safe-path' to '/', effectively disabling this
1192 * New remote packets
1194 z0/z1 conditional breakpoints extension
1196 The z0/z1 breakpoint insertion packets have been extended to carry
1197 a list of conditional expressions over to the remote stub depending on the
1198 condition evaluation mode. The use of this extension can be controlled
1199 via the "set remote conditional-breakpoints-packet" command.
1203 Specify the signals which the remote stub may pass to the debugged
1204 program without GDB involvement.
1206 * New command line options
1208 --init-command=FILE, -ix Like --command, -x but execute it
1209 before loading inferior.
1210 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1211 execute it before loading inferior.
1213 *** Changes in GDB 7.4
1215 * GDB now handles ambiguous linespecs more consistently; the existing
1216 FILE:LINE support has been expanded to other types of linespecs. A
1217 breakpoint will now be set on all matching locations in all
1218 inferiors, and locations will be added or removed according to
1221 * GDB now allows you to skip uninteresting functions and files when
1222 stepping with the "skip function" and "skip file" commands.
1224 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1225 and "show remote hardware-watchpoint-length-limit". These allows to
1226 set or show the maximum length limit (in bytes) of a remote
1227 target hardware watchpoint.
1229 This allows e.g. to use "unlimited" hardware watchpoints with the
1230 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1231 watchpoints are slower than real hardware watchpoints but are
1232 significantly faster than gdb software watchpoints.
1236 ** The register_pretty_printer function in module gdb.printing now takes
1237 an optional `replace' argument. If True, the new printer replaces any
1240 ** The "maint set python print-stack on|off" command has been
1241 deprecated and will be deleted in GDB 7.5.
1242 A new command: "set python print-stack none|full|message" has
1243 replaced it. Additionally, the default for "print-stack" is
1244 now "message", which just prints the error message without
1247 ** A prompt substitution hook (prompt_hook) is now available to the
1250 ** A new Python module, gdb.prompt has been added to the GDB Python
1251 modules library. This module provides functionality for
1252 escape sequences in prompts (used by set/show
1253 extended-prompt). These escape sequences are replaced by their
1254 corresponding value.
1256 ** Python commands and convenience-functions located in
1257 'data-directory'/python/gdb/command and
1258 'data-directory'/python/gdb/function are now automatically loaded
1261 ** Blocks now provide four new attributes. global_block and
1262 static_block will return the global and static blocks
1263 respectively. is_static and is_global are boolean attributes
1264 that indicate if the block is one of those two types.
1266 ** Symbols now provide the "type" attribute, the type of the symbol.
1268 ** The "gdb.breakpoint" function has been deprecated in favor of
1271 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1272 of a function. This class is based on the "finish" command
1273 available in the CLI.
1275 ** Type objects for struct and union types now allow access to
1276 the fields using standard Python dictionary (mapping) methods.
1277 For example, "some_type['myfield']" now works, as does
1278 "some_type.items()".
1280 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1283 ** A new function, "deep_items" has been added to the gdb.types
1284 module in the GDB Python modules library. This function returns
1285 an iterator over the fields of a struct or union type. Unlike
1286 the standard Python "iteritems" method, it will recursively traverse
1287 any anonymous fields.
1291 ** "*stopped" events can report several new "reason"s, such as
1294 ** Breakpoint changes are now notified using new async records, like
1295 "=breakpoint-modified".
1297 ** New command -ada-task-info.
1299 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1300 $sdir specifies the default system locations of shared libraries.
1301 $pdir specifies the directory where the libpthread used by the application
1304 GDB no longer looks in $sdir and $pdir after it has searched the directories
1305 mentioned in libthread-db-search-path. If you want to search those
1306 directories, they must be specified in libthread-db-search-path.
1307 The default value of libthread-db-search-path on GNU/Linux and Solaris
1308 systems is now "$sdir:$pdir".
1310 $pdir is not supported by gdbserver, it is currently ignored.
1311 $sdir is supported by gdbserver.
1313 * New configure option --with-iconv-bin.
1314 When using the internationalization support like the one in the GNU C
1315 library, GDB will invoke the "iconv" program to get a list of supported
1316 character sets. If this program lives in a non-standard location, one can
1317 use this option to specify where to find it.
1319 * When natively debugging programs on PowerPC BookE processors running
1320 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1321 watchpoints, which specify a mask in addition to an address to watch.
1322 The mask specifies that some bits of an address (the bits which are
1323 reset in the mask) should be ignored when matching the address accessed
1324 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1325 section in the user manual for more details.
1327 * The new option --once causes GDBserver to stop listening for connections once
1328 the first connection is made. The listening port used by GDBserver will
1329 become available after that.
1331 * New commands "info macros" and "alias" have been added.
1333 * New function parameters suffix @entry specifies value of function parameter
1334 at the time the function got called. Entry values are available only since
1340 "!" is now an alias of the "shell" command.
1341 Note that no space is needed between "!" and SHELL COMMAND.
1345 watch EXPRESSION mask MASK_VALUE
1346 The watch command now supports the mask argument which allows creation
1347 of masked watchpoints, if the current architecture supports this feature.
1349 info auto-load-scripts [REGEXP]
1350 This command was formerly named "maintenance print section-scripts".
1351 It is now generally useful and is no longer a maintenance-only command.
1353 info macro [-all] [--] MACRO
1354 The info macro command has new options `-all' and `--'. The first for
1355 printing all definitions of a macro. The second for explicitly specifying
1356 the end of arguments and the beginning of the macro name in case the macro
1357 name starts with a hyphen.
1359 collect[/s] EXPRESSIONS
1360 The tracepoint collect command now takes an optional modifier "/s"
1361 that directs it to dereference pointer-to-character types and
1362 collect the bytes of memory up to a zero byte. The behavior is
1363 similar to what you see when you use the regular print command on a
1364 string. An optional integer following the "/s" sets a bound on the
1365 number of bytes that will be collected.
1368 The trace start command now interprets any supplied arguments as a
1369 note to be recorded with the trace run, with an effect similar to
1370 setting the variable trace-notes.
1373 The trace stop command now interprets any arguments as a note to be
1374 mentioned along with the tstatus report that the trace was stopped
1375 with a command. The effect is similar to setting the variable
1378 * Tracepoints can now be enabled and disabled at any time after a trace
1379 experiment has been started using the standard "enable" and "disable"
1380 commands. It is now possible to start a trace experiment with no enabled
1381 tracepoints; GDB will display a warning, but will allow the experiment to
1382 begin, assuming that tracepoints will be enabled as needed while the trace
1385 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1386 locations with 4-byte instructions, when they were previously
1387 limited to locations with instructions of 5 bytes or longer.
1391 set debug dwarf2-read
1392 show debug dwarf2-read
1393 Turns on or off display of debugging messages related to reading
1394 DWARF debug info. The default is off.
1396 set debug symtab-create
1397 show debug symtab-create
1398 Turns on or off display of debugging messages related to symbol table
1399 creation. The default is off.
1402 show extended-prompt
1403 Set the GDB prompt, and allow escape sequences to be inserted to
1404 display miscellaneous information (see 'help set extended-prompt'
1405 for the list of sequences). This prompt (and any information
1406 accessed through the escape sequences) is updated every time the
1407 prompt is displayed.
1409 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1410 show print entry-values
1411 Set printing of frame argument values at function entry. In some cases
1412 GDB can determine the value of function argument which was passed by the
1413 function caller, even if the value was modified inside the called function.
1415 set debug entry-values
1416 show debug entry-values
1417 Control display of debugging info for determining frame argument values at
1418 function entry and virtual tail call frames.
1420 set basenames-may-differ
1421 show basenames-may-differ
1422 Set whether a source file may have multiple base names.
1423 (A "base name" is the name of a file with the directory part removed.
1424 Example: The base name of "/home/user/hello.c" is "hello.c".)
1425 If set, GDB will canonicalize file names (e.g., expand symlinks)
1426 before comparing them. Canonicalization is an expensive operation,
1427 but it allows the same file be known by more than one base name.
1428 If not set (the default), all source files are assumed to have just
1429 one base name, and gdb will do file name comparisons more efficiently.
1435 Set a user name and notes for the current and any future trace runs.
1436 This is useful for long-running and/or disconnected traces, to
1437 inform others (or yourself) as to who is running the trace, supply
1438 contact information, or otherwise explain what is going on.
1440 set trace-stop-notes
1441 show trace-stop-notes
1442 Set a note attached to the trace run, that is displayed when the
1443 trace has been stopped by a tstop command. This is useful for
1444 instance as an explanation, if you are stopping a trace run that was
1445 started by someone else.
1447 * New remote packets
1451 Dynamically enable a tracepoint in a started trace experiment.
1455 Dynamically disable a tracepoint in a started trace experiment.
1459 Set the user and notes of the trace run.
1463 Query the current status of a tracepoint.
1467 Query the minimum length of instruction at which a fast tracepoint may
1470 * Dcache size (number of lines) and line-size are now runtime-configurable
1471 via "set dcache line" and "set dcache line-size" commands.
1475 Texas Instruments TMS320C6x tic6x-*-*
1479 Renesas RL78 rl78-*-elf
1481 *** Changes in GDB 7.3.1
1483 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1485 *** Changes in GDB 7.3
1487 * GDB has a new command: "thread find [REGEXP]".
1488 It finds the thread id whose name, target id, or thread extra info
1489 matches the given regular expression.
1491 * The "catch syscall" command now works on mips*-linux* targets.
1493 * The -data-disassemble MI command now supports modes 2 and 3 for
1494 dumping the instruction opcodes.
1496 * New command line options
1498 -data-directory DIR Specify DIR as the "data-directory".
1499 This is mostly for testing purposes.
1501 * The "maint set python auto-load on|off" command has been renamed to
1502 "set auto-load-scripts on|off".
1504 * GDB has a new command: "set directories".
1505 It is like the "dir" command except that it replaces the
1506 source path list instead of augmenting it.
1508 * GDB now understands thread names.
1510 On GNU/Linux, "info threads" will display the thread name as set by
1511 prctl or pthread_setname_np.
1513 There is also a new command, "thread name", which can be used to
1514 assign a name internally for GDB to display.
1517 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1518 has been integrated into GDB.
1522 ** The function gdb.Write now accepts an optional keyword 'stream'.
1523 This keyword, when provided, will direct the output to either
1524 stdout, stderr, or GDB's logging output.
1526 ** Parameters can now be be sub-classed in Python, and in particular
1527 you may implement the get_set_doc and get_show_doc functions.
1528 This improves how Parameter set/show documentation is processed
1529 and allows for more dynamic content.
1531 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1532 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1533 have an is_valid method.
1535 ** Breakpoints can now be sub-classed in Python, and in particular
1536 you may implement a 'stop' function that is executed each time
1537 the inferior reaches that breakpoint.
1539 ** New function gdb.lookup_global_symbol looks up a global symbol.
1541 ** GDB values in Python are now callable if the value represents a
1542 function. For example, if 'some_value' represents a function that
1543 takes two integer parameters and returns a value, you can call
1544 that function like so:
1546 result = some_value (10,20)
1548 ** Module gdb.types has been added.
1549 It contains a collection of utilities for working with gdb.Types objects:
1550 get_basic_type, has_field, make_enum_dict.
1552 ** Module gdb.printing has been added.
1553 It contains utilities for writing and registering pretty-printers.
1554 New classes: PrettyPrinter, SubPrettyPrinter,
1555 RegexpCollectionPrettyPrinter.
1556 New function: register_pretty_printer.
1558 ** New commands "info pretty-printers", "enable pretty-printer" and
1559 "disable pretty-printer" have been added.
1561 ** gdb.parameter("directories") is now available.
1563 ** New function gdb.newest_frame returns the newest frame in the
1566 ** The gdb.InferiorThread class has a new "name" attribute. This
1567 holds the thread's name.
1569 ** Python Support for Inferior events.
1570 Python scripts can add observers to be notified of events
1571 occurring in the process being debugged.
1572 The following events are currently supported:
1573 - gdb.events.cont Continue event.
1574 - gdb.events.exited Inferior exited event.
1575 - gdb.events.stop Signal received, and Breakpoint hit events.
1579 ** GDB now puts template parameters in scope when debugging in an
1580 instantiation. For example, if you have:
1582 template<int X> int func (void) { return X; }
1584 then if you step into func<5>, "print X" will show "5". This
1585 feature requires proper debuginfo support from the compiler; it
1586 was added to GCC 4.5.
1588 ** The motion commands "next", "finish", "until", and "advance" now
1589 work better when exceptions are thrown. In particular, GDB will
1590 no longer lose control of the inferior; instead, the GDB will
1591 stop the inferior at the point at which the exception is caught.
1592 This functionality requires a change in the exception handling
1593 code that was introduced in GCC 4.5.
1595 * GDB now follows GCC's rules on accessing volatile objects when
1596 reading or writing target state during expression evaluation.
1597 One notable difference to prior behavior is that "print x = 0"
1598 no longer generates a read of x; the value of the assignment is
1599 now always taken directly from the value being assigned.
1601 * GDB now has some support for using labels in the program's source in
1602 linespecs. For instance, you can use "advance label" to continue
1603 execution to a label.
1605 * GDB now has support for reading and writing a new .gdb_index
1606 section. This section holds a fast index of DWARF debugging
1607 information and can be used to greatly speed up GDB startup and
1608 operation. See the documentation for `save gdb-index' for details.
1610 * The "watch" command now accepts an optional "-location" argument.
1611 When used, this causes GDB to watch the memory referred to by the
1612 expression. Such a watchpoint is never deleted due to it going out
1615 * GDB now supports thread debugging of core dumps on GNU/Linux.
1617 GDB now activates thread debugging using the libthread_db library
1618 when debugging GNU/Linux core dumps, similarly to when debugging
1619 live processes. As a result, when debugging a core dump file, GDB
1620 is now able to display pthread_t ids of threads. For example, "info
1621 threads" shows the same output as when debugging the process when it
1622 was live. In earlier releases, you'd see something like this:
1625 * 1 LWP 6780 main () at main.c:10
1627 While now you see this:
1630 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1632 It is also now possible to inspect TLS variables when debugging core
1635 When debugging a core dump generated on a machine other than the one
1636 used to run GDB, you may need to point GDB at the correct
1637 libthread_db library with the "set libthread-db-search-path"
1638 command. See the user manual for more details on this command.
1640 * When natively debugging programs on PowerPC BookE processors running
1641 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1642 which stop execution of the inferior whenever it executes an instruction
1643 at any address within the specified range. See the "PowerPC Embedded"
1644 section in the user manual for more details.
1646 * New features in the GDB remote stub, GDBserver
1648 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1649 and i686 LynxOS (version 5.x).
1651 ** GDBserver is now supported on Blackfin Linux.
1653 * New native configurations
1655 ia64 HP-UX ia64-*-hpux*
1659 Analog Devices, Inc. Blackfin Processor bfin-*
1661 * Ada task switching is now supported on sparc-elf targets when
1662 debugging a program using the Ravenscar Profile. For more information,
1663 see the "Tasking Support when using the Ravenscar Profile" section
1664 in the GDB user manual.
1666 * Guile support was removed.
1668 * New features in the GNU simulator
1670 ** The --map-info flag lists all known core mappings.
1672 ** CFI flashes may be simulated via the "cfi" device.
1674 *** Changes in GDB 7.2
1676 * Shared library support for remote targets by default
1678 When GDB is configured for a generic, non-OS specific target, like
1679 for example, --target=arm-eabi or one of the many *-*-elf targets,
1680 GDB now queries remote stubs for loaded shared libraries using the
1681 `qXfer:libraries:read' packet. Previously, shared library support
1682 was always disabled for such configurations.
1686 ** Argument Dependent Lookup (ADL)
1688 In C++ ADL lookup directs function search to the namespaces of its
1689 arguments even if the namespace has not been imported.
1699 Here the compiler will search for `foo' in the namespace of 'b'
1700 and find A::foo. GDB now supports this. This construct is commonly
1701 used in the Standard Template Library for operators.
1703 ** Improved User Defined Operator Support
1705 In addition to member operators, GDB now supports lookup of operators
1706 defined in a namespace and imported with a `using' directive, operators
1707 defined in the global scope, operators imported implicitly from an
1708 anonymous namespace, and the ADL operators mentioned in the previous
1710 GDB now also supports proper overload resolution for all the previously
1711 mentioned flavors of operators.
1713 ** static const class members
1715 Printing of static const class members that are initialized in the
1716 class definition has been fixed.
1718 * Windows Thread Information Block access.
1720 On Windows targets, GDB now supports displaying the Windows Thread
1721 Information Block (TIB) structure. This structure is visible either
1722 by using the new command `info w32 thread-information-block' or, by
1723 dereferencing the new convenience variable named `$_tlb', a
1724 thread-specific pointer to the TIB. This feature is also supported
1725 when remote debugging using GDBserver.
1727 * Static tracepoints
1729 Static tracepoints are calls in the user program into a tracing
1730 library. One such library is a port of the LTTng kernel tracer to
1731 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1732 When debugging with GDBserver, GDB now supports combining the GDB
1733 tracepoint machinery with such libraries. For example: the user can
1734 use GDB to probe a static tracepoint marker (a call from the user
1735 program into the tracing library) with the new "strace" command (see
1736 "New commands" below). This creates a "static tracepoint" in the
1737 breakpoint list, that can be manipulated with the same feature set
1738 as fast and regular tracepoints. E.g., collect registers, local and
1739 global variables, collect trace state variables, and define
1740 tracepoint conditions. In addition, the user can collect extra
1741 static tracepoint marker specific data, by collecting the new
1742 $_sdata internal variable. When analyzing the trace buffer, you can
1743 inspect $_sdata like any other variable available to GDB. For more
1744 information, see the "Tracepoints" chapter in GDB user manual. New
1745 remote packets have been defined to support static tracepoints, see
1746 the "New remote packets" section below.
1748 * Better reconstruction of tracepoints after disconnected tracing
1750 GDB will attempt to download the original source form of tracepoint
1751 definitions when starting a trace run, and then will upload these
1752 upon reconnection to the target, resulting in a more accurate
1753 reconstruction of the tracepoints that are in use on the target.
1757 You can now exercise direct control over the ways that GDB can
1758 affect your program. For instance, you can disallow the setting of
1759 breakpoints, so that the program can run continuously (assuming
1760 non-stop mode). In addition, the "observer" variable is available
1761 to switch all of the different controls; in observer mode, GDB
1762 cannot affect the target's behavior at all, which is useful for
1763 tasks like diagnosing live systems in the field.
1765 * The new convenience variable $_thread holds the number of the
1768 * New remote packets
1772 Return the address of the Windows Thread Information Block of a given thread.
1776 In response to several of the tracepoint packets, the target may now
1777 also respond with a number of intermediate `qRelocInsn' request
1778 packets before the final result packet, to have GDB handle
1779 relocating an instruction to execute at a different address. This
1780 is particularly useful for stubs that support fast tracepoints. GDB
1781 reports support for this feature in the qSupported packet.
1785 List static tracepoint markers in the target program.
1789 List static tracepoint markers at a given address in the target
1792 qXfer:statictrace:read
1794 Read the static trace data collected (by a `collect $_sdata'
1795 tracepoint action). The remote stub reports support for this packet
1796 to gdb's qSupported query.
1800 Send the current settings of GDB's permission flags.
1804 Send part of the source (textual) form of a tracepoint definition,
1805 which includes location, conditional, and action list.
1807 * The source command now accepts a -s option to force searching for the
1808 script in the source search path even if the script name specifies
1811 * New features in the GDB remote stub, GDBserver
1813 - GDBserver now support tracepoints (including fast tracepoints, and
1814 static tracepoints). The feature is currently supported by the
1815 i386-linux and amd64-linux builds. See the "Tracepoints support
1816 in gdbserver" section in the manual for more information.
1818 GDBserver JIT compiles the tracepoint's conditional agent
1819 expression bytecode into native code whenever possible for low
1820 overhead dynamic tracepoints conditionals. For such tracepoints,
1821 an expression that examines program state is evaluated when the
1822 tracepoint is reached, in order to determine whether to capture
1823 trace data. If the condition is simple and false, processing the
1824 tracepoint finishes very quickly and no data is gathered.
1826 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1827 for static tracepoints support.
1829 - GDBserver now supports x86_64 Windows 64-bit debugging.
1831 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1832 it understands register description.
1834 * The --batch flag now disables pagination and queries.
1836 * X86 general purpose registers
1838 GDB now supports reading/writing byte, word and double-word x86
1839 general purpose registers directly. This means you can use, say,
1840 $ah or $ax to refer, respectively, to the byte register AH and
1841 16-bit word register AX that are actually portions of the 32-bit
1842 register EAX or 64-bit register RAX.
1844 * The `commands' command now accepts a range of breakpoints to modify.
1845 A plain `commands' following a command that creates multiple
1846 breakpoints affects all the breakpoints set by that command. This
1847 applies to breakpoints set by `rbreak', and also applies when a
1848 single `break' command creates multiple breakpoints (e.g.,
1849 breakpoints on overloaded c++ functions).
1851 * The `rbreak' command now accepts a filename specification as part of
1852 its argument, limiting the functions selected by the regex to those
1853 in the specified file.
1855 * Support for remote debugging Windows and SymbianOS shared libraries
1856 from Unix hosts has been improved. Non Windows GDB builds now can
1857 understand target reported file names that follow MS-DOS based file
1858 system semantics, such as file names that include drive letters and
1859 use the backslash character as directory separator. This makes it
1860 possible to transparently use the "set sysroot" and "set
1861 solib-search-path" on Unix hosts to point as host copies of the
1862 target's shared libraries. See the new command "set
1863 target-file-system-kind" described below, and the "Commands to
1864 specify files" section in the user manual for more information.
1868 eval template, expressions...
1869 Convert the values of one or more expressions under the control
1870 of the string template to a command line, and call it.
1872 set target-file-system-kind unix|dos-based|auto
1873 show target-file-system-kind
1874 Set or show the assumed file system kind for target reported file
1877 save breakpoints <filename>
1878 Save all current breakpoint definitions to a file suitable for use
1879 in a later debugging session. To read the saved breakpoint
1880 definitions, use the `source' command.
1882 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1885 info static-tracepoint-markers
1886 Display information about static tracepoint markers in the target.
1888 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1889 Define a static tracepoint by probing a marker at the given
1890 function, line, address, or marker ID.
1894 Enable and disable observer mode.
1896 set may-write-registers on|off
1897 set may-write-memory on|off
1898 set may-insert-breakpoints on|off
1899 set may-insert-tracepoints on|off
1900 set may-insert-fast-tracepoints on|off
1901 set may-interrupt on|off
1902 Set individual permissions for GDB effects on the target. Note that
1903 some of these settings can have undesirable or surprising
1904 consequences, particularly when changed in the middle of a session.
1905 For instance, disabling the writing of memory can prevent
1906 breakpoints from being inserted, cause single-stepping to fail, or
1907 even crash your program, if you disable after breakpoints have been
1908 inserted. However, GDB should not crash.
1910 set record memory-query on|off
1911 show record memory-query
1912 Control whether to stop the inferior if memory changes caused
1913 by an instruction cannot be recorded.
1918 The disassemble command now supports "start,+length" form of two arguments.
1922 ** GDB now provides a new directory location, called the python directory,
1923 where Python scripts written for GDB can be installed. The location
1924 of that directory is <data-directory>/python, where <data-directory>
1925 is the GDB data directory. For more details, see section `Scripting
1926 GDB using Python' in the manual.
1928 ** The GDB Python API now has access to breakpoints, symbols, symbol
1929 tables, program spaces, inferiors, threads and frame's code blocks.
1930 Additionally, GDB Parameters can now be created from the API, and
1931 manipulated via set/show in the CLI.
1933 ** New functions gdb.target_charset, gdb.target_wide_charset,
1934 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1936 ** New exception gdb.GdbError.
1938 ** Pretty-printers are now also looked up in the current program space.
1940 ** Pretty-printers can now be individually enabled and disabled.
1942 ** GDB now looks for names of Python scripts to auto-load in a
1943 special section named `.debug_gdb_scripts', in addition to looking
1944 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1946 * Tracepoint actions were unified with breakpoint commands. In particular,
1947 there are no longer differences in "info break" output for breakpoints and
1948 tracepoints and the "commands" command can be used for both tracepoints and
1949 regular breakpoints.
1953 ARM Symbian arm*-*-symbianelf*
1955 * D language support.
1956 GDB now supports debugging programs written in the D programming
1959 * GDB now supports the extended ptrace interface for PowerPC which is
1960 available since Linux kernel version 2.6.34. This automatically enables
1961 any hardware breakpoints and additional hardware watchpoints available in
1962 the processor. The old ptrace interface exposes just one hardware
1963 watchpoint and no hardware breakpoints.
1965 * GDB is now able to use the Data Value Compare (DVC) register available on
1966 embedded PowerPC processors to implement in hardware simple watchpoint
1967 conditions of the form:
1969 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1971 This works in native GDB running on Linux kernels with the extended ptrace
1972 interface mentioned above.
1974 *** Changes in GDB 7.1
1978 ** Namespace Support
1980 GDB now supports importing of namespaces in C++. This enables the
1981 user to inspect variables from imported namespaces. Support for
1982 namepace aliasing has also been added. So, if a namespace is
1983 aliased in the current scope (e.g. namepace C=A; ) the user can
1984 print variables using the alias (e.g. (gdb) print C::x).
1988 All known bugs relating to the printing of virtual base class were
1989 fixed. It is now possible to call overloaded static methods using a
1994 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1995 and reinterpret_cast<> are now handled by the C++ expression parser.
1999 Xilinx MicroBlaze microblaze-*-*
2004 Xilinx MicroBlaze microblaze
2007 * Multi-program debugging.
2009 GDB now has support for multi-program (a.k.a. multi-executable or
2010 multi-exec) debugging. This allows for debugging multiple inferiors
2011 simultaneously each running a different program under the same GDB
2012 session. See "Debugging Multiple Inferiors and Programs" in the
2013 manual for more information. This implied some user visible changes
2014 in the multi-inferior support. For example, "info inferiors" now
2015 lists inferiors that are not running yet or that have exited
2016 already. See also "New commands" and "New options" below.
2018 * New tracing features
2020 GDB's tracepoint facility now includes several new features:
2022 ** Trace state variables
2024 GDB tracepoints now include support for trace state variables, which
2025 are variables managed by the target agent during a tracing
2026 experiment. They are useful for tracepoints that trigger each
2027 other, so for instance one tracepoint can count hits in a variable,
2028 and then a second tracepoint has a condition that is true when the
2029 count reaches a particular value. Trace state variables share the
2030 $-syntax of GDB convenience variables, and can appear in both
2031 tracepoint actions and condition expressions. Use the "tvariable"
2032 command to create, and "info tvariables" to view; see "Trace State
2033 Variables" in the manual for more detail.
2037 GDB now includes an option for defining fast tracepoints, which
2038 targets may implement more efficiently, such as by installing a jump
2039 into the target agent rather than a trap instruction. The resulting
2040 speedup can be by two orders of magnitude or more, although the
2041 tradeoff is that some program locations on some target architectures
2042 might not allow fast tracepoint installation, for instance if the
2043 instruction to be replaced is shorter than the jump. To request a
2044 fast tracepoint, use the "ftrace" command, with syntax identical to
2045 the regular trace command.
2047 ** Disconnected tracing
2049 It is now possible to detach GDB from the target while it is running
2050 a trace experiment, then reconnect later to see how the experiment
2051 is going. In addition, a new variable disconnected-tracing lets you
2052 tell the target agent whether to continue running a trace if the
2053 connection is lost unexpectedly.
2057 GDB now has the ability to save the trace buffer into a file, and
2058 then use that file as a target, similarly to you can do with
2059 corefiles. You can select trace frames, print data that was
2060 collected in them, and use tstatus to display the state of the
2061 tracing run at the moment that it was saved. To create a trace
2062 file, use "tsave <filename>", and to use it, do "target tfile
2065 ** Circular trace buffer
2067 You can ask the target agent to handle the trace buffer as a
2068 circular buffer, discarding the oldest trace frames to make room for
2069 newer ones, by setting circular-trace-buffer to on. This feature may
2070 not be available for all target agents.
2075 The disassemble command, when invoked with two arguments, now requires
2076 the arguments to be comma-separated.
2079 The info variables command now displays variable definitions. Files
2080 which only declare a variable are not shown.
2083 The source command is now capable of sourcing Python scripts.
2084 This feature is dependent on the debugger being build with Python
2087 Related to this enhancement is also the introduction of a new command
2088 "set script-extension" (see below).
2090 * New commands (for set/show, see "New options" below)
2092 record save [<FILENAME>]
2093 Save a file (in core file format) containing the process record
2094 execution log for replay debugging at a later time.
2096 record restore <FILENAME>
2097 Restore the process record execution log that was saved at an
2098 earlier time, for replay debugging.
2100 add-inferior [-copies <N>] [-exec <FILENAME>]
2103 clone-inferior [-copies <N>] [ID]
2104 Make a new inferior ready to execute the same program another
2105 inferior has loaded.
2110 maint info program-spaces
2111 List the program spaces loaded into GDB.
2113 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2114 show remote interrupt-sequence
2115 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2116 as the sequence to the remote target in order to interrupt the execution.
2117 Ctrl-C is a default. Some system prefers BREAK which is high level of
2118 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2119 Magic SysRq g. It is BREAK signal and character 'g'.
2121 set remote interrupt-on-connect [on | off]
2122 show remote interrupt-on-connect
2123 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2124 remote target when gdb connects to it. This is needed when you debug
2127 set remotebreak [on | off]
2129 Deprecated. Use "set/show remote interrupt-sequence" instead.
2131 tvariable $NAME [ = EXP ]
2132 Create or modify a trace state variable.
2135 List trace state variables and their values.
2137 delete tvariable $NAME ...
2138 Delete one or more trace state variables.
2141 Evaluate the given expressions without collecting anything into the
2142 trace buffer. (Valid in tracepoint actions only.)
2144 ftrace FN / FILE:LINE / *ADDR
2145 Define a fast tracepoint at the given function, line, or address.
2147 * New expression syntax
2149 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2150 GDB now parses 0b101010 identically with 42.
2154 set follow-exec-mode new|same
2155 show follow-exec-mode
2156 Control whether GDB reuses the same inferior across an exec call or
2157 creates a new one. This is useful to be able to restart the old
2158 executable after the inferior having done an exec call.
2160 set default-collect EXPR, ...
2161 show default-collect
2162 Define a list of expressions to be collected at each tracepoint.
2163 This is a useful way to ensure essential items are not overlooked,
2164 such as registers or a critical global variable.
2166 set disconnected-tracing
2167 show disconnected-tracing
2168 If set to 1, the target is instructed to continue tracing if it
2169 loses its connection to GDB. If 0, the target is to stop tracing
2172 set circular-trace-buffer
2173 show circular-trace-buffer
2174 If set to on, the target is instructed to use a circular trace buffer
2175 and discard the oldest trace frames instead of stopping the trace due
2176 to a full trace buffer. If set to off, the trace stops when the buffer
2177 fills up. Some targets may not support this.
2179 set script-extension off|soft|strict
2180 show script-extension
2181 If set to "off", the debugger does not perform any script language
2182 recognition, and all sourced files are assumed to be GDB scripts.
2183 If set to "soft" (the default), files are sourced according to
2184 filename extension, falling back to GDB scripts if the first
2186 If set to "strict", files are sourced according to filename extension.
2188 set ada trust-PAD-over-XVS on|off
2189 show ada trust-PAD-over-XVS
2190 If off, activate a workaround against a bug in the debugging information
2191 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2192 the GCC sources for more information about the GNAT encoding and
2193 PAD types in particular). It is always safe to set this option to
2194 off, but this introduces a slight performance penalty. The default
2197 * Python API Improvements
2199 ** GDB provides the new class gdb.LazyString. This is useful in
2200 some pretty-printing cases. The new method gdb.Value.lazy_string
2201 provides a simple way to create objects of this type.
2203 ** The fields returned by gdb.Type.fields now have an
2204 `is_base_class' attribute.
2206 ** The new method gdb.Type.range returns the range of an array type.
2208 ** The new method gdb.parse_and_eval can be used to parse and
2209 evaluate an expression.
2211 * New remote packets
2214 Define a trace state variable.
2217 Get the current value of a trace state variable.
2220 Set desired tracing behavior upon disconnection.
2223 Set the trace buffer to be linear or circular.
2226 Get data about the tracepoints currently in use.
2230 Process record now works correctly with hardware watchpoints.
2232 Multiple bug fixes have been made to the mips-irix port, making it
2233 much more reliable. In particular:
2234 - Debugging threaded applications is now possible again. Previously,
2235 GDB would hang while starting the program, or while waiting for
2236 the program to stop at a breakpoint.
2237 - Attaching to a running process no longer hangs.
2238 - An error occurring while loading a core file has been fixed.
2239 - Changing the value of the PC register now works again. This fixes
2240 problems observed when using the "jump" command, or when calling
2241 a function from GDB, or even when assigning a new value to $pc.
2242 - With the "finish" and "return" commands, the return value for functions
2243 returning a small array is now correctly printed.
2244 - It is now possible to break on shared library code which gets executed
2245 during a shared library init phase (code executed while executing
2246 their .init section). Previously, the breakpoint would have no effect.
2247 - GDB is now able to backtrace through the signal handler for
2248 non-threaded programs.
2250 PIE (Position Independent Executable) programs debugging is now supported.
2251 This includes debugging execution of PIC (Position Independent Code) shared
2252 libraries although for that, it should be possible to run such libraries as an
2255 *** Changes in GDB 7.0
2257 * GDB now has an interface for JIT compilation. Applications that
2258 dynamically generate code can create symbol files in memory and register
2259 them with GDB. For users, the feature should work transparently, and
2260 for JIT developers, the interface is documented in the GDB manual in the
2261 "JIT Compilation Interface" chapter.
2263 * Tracepoints may now be conditional. The syntax is as for
2264 breakpoints; either an "if" clause appended to the "trace" command,
2265 or the "condition" command is available. GDB sends the condition to
2266 the target for evaluation using the same bytecode format as is used
2267 for tracepoint actions.
2269 * The disassemble command now supports: an optional /r modifier, print the
2270 raw instructions in hex as well as in symbolic form, and an optional /m
2271 modifier to print mixed source+assembly.
2273 * Process record and replay
2275 In a architecture environment that supports ``process record and
2276 replay'', ``process record and replay'' target can record a log of
2277 the process execution, and replay it with both forward and reverse
2280 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2281 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2282 set execution-direction {forward|reverse}, for targets that support
2285 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2286 feature is available with a native GDB running on kernel version
2289 * GDB now has support for multi-byte and wide character sets on the
2290 target. Strings whose character type is wchar_t, char16_t, or
2291 char32_t are now correctly printed. GDB supports wide- and unicode-
2292 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2293 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2294 `printf'. This feature requires iconv to work properly; if your
2295 system does not have a working iconv, GDB can use GNU libiconv. See
2296 the installation instructions for more information.
2298 * GDB now supports automatic retrieval of shared library files from
2299 remote targets. To use this feature, specify a system root that begins
2300 with the `remote:' prefix, either via the `set sysroot' command or via
2301 the `--with-sysroot' configure-time option.
2303 * "info sharedlibrary" now takes an optional regex of libraries to show,
2304 and it now reports if a shared library has no debugging information.
2306 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2307 now complete on file names.
2309 * When completing in expressions, gdb will attempt to limit
2310 completions to allowable structure or union fields, where appropriate.
2311 For instance, consider:
2313 # struct example { int f1; double f2; };
2314 # struct example variable;
2317 If the user types TAB at the end of this command line, the available
2318 completions will be "f1" and "f2".
2320 * Inlined functions are now supported. They show up in backtraces, and
2321 the "step", "next", and "finish" commands handle them automatically.
2323 * GDB now supports the token-splicing (##) and stringification (#)
2324 operators when expanding macros. It also supports variable-arity
2327 * GDB now supports inspecting extra signal information, exported by
2328 the new $_siginfo convenience variable. The feature is currently
2329 implemented on linux ARM, i386 and amd64.
2331 * GDB can now display the VFP floating point registers and NEON vector
2332 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2333 can provide these registers (requires Linux 2.6.30 or later). Remote
2334 and simulator targets may also provide them.
2336 * New remote packets
2339 Search memory for a sequence of bytes.
2342 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2343 operation over reliable transport links. Use of this packet is
2344 controlled by the `set remote noack-packet' command.
2347 Kill the process with the specified process ID. Use this in preference
2348 to `k' when multiprocess protocol extensions are supported.
2351 Obtains additional operating system information
2355 Read or write additional signal information.
2357 * Removed remote protocol undocumented extension
2359 An undocumented extension to the remote protocol's `S' stop reply
2360 packet that permited the stub to pass a process id was removed.
2361 Remote servers should use the `T' stop reply packet instead.
2363 * GDB now supports multiple function calling conventions according to the
2364 DWARF-2 DW_AT_calling_convention function attribute.
2366 * The SH target utilizes the aforementioned change to distinguish between gcc
2367 and Renesas calling convention. It also adds the new CLI commands
2368 `set/show sh calling-convention'.
2370 * GDB can now read compressed debug sections, as produced by GNU gold
2371 with the --compress-debug-sections=zlib flag.
2373 * 64-bit core files are now supported on AIX.
2375 * Thread switching is now supported on Tru64.
2377 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2378 which will be allocated using malloc later in program execution.
2380 * The qXfer:libraries:read remote procotol packet now allows passing a
2381 list of section offsets.
2383 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2384 conditions handling signals delivered during attach or thread creation
2385 have also been fixed.
2387 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2388 From the user's standpoint, all unqualified instances of True and False
2389 are treated as the standard definitions, regardless of context.
2391 * GDB now parses C++ symbol and type names more flexibly. For
2394 template<typename T> class C { };
2397 GDB will now correctly handle all of:
2399 ptype C<char const *>
2400 ptype C<char const*>
2401 ptype C<const char *>
2402 ptype C<const char*>
2404 * New features in the GDB remote stub, gdbserver
2406 - The "--wrapper" command-line argument tells gdbserver to use a
2407 wrapper program to launch programs for debugging.
2409 - On PowerPC and S/390 targets, it is now possible to use a single
2410 gdbserver executable to debug both 32-bit and 64-bit programs.
2411 (This requires gdbserver itself to be built as a 64-bit executable.)
2413 - gdbserver uses the new noack protocol mode for TCP connections to
2414 reduce communications latency, if also supported and enabled in GDB.
2416 - Support for the sparc64-linux-gnu target is now included in
2419 - The amd64-linux build of gdbserver now supports debugging both
2420 32-bit and 64-bit programs.
2422 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2423 now support hardware watchpoints, and will use them automatically
2428 GDB now has support for scripting using Python. Whether this is
2429 available is determined at configure time.
2431 New GDB commands can now be written in Python.
2433 * Ada tasking support
2435 Ada tasks can now be inspected in GDB. The following commands have
2439 Print the list of Ada tasks.
2441 Print detailed information about task number N.
2443 Print the task number of the current task.
2445 Switch the context of debugging to task number N.
2447 * Support for user-defined prefixed commands. The "define" command can
2448 add new commands to existing prefixes, e.g. "target".
2450 * Multi-inferior, multi-process debugging.
2452 GDB now has generalized support for multi-inferior debugging. See
2453 "Debugging Multiple Inferiors" in the manual for more information.
2454 Although availability still depends on target support, the command
2455 set is more uniform now. The GNU/Linux specific multi-forks support
2456 has been migrated to this new framework. This implied some user
2457 visible changes; see "New commands" and also "Removed commands"
2460 * Target descriptions can now describe the target OS ABI. See the
2461 "Target Description Format" section in the user manual for more
2464 * Target descriptions can now describe "compatible" architectures
2465 to indicate that the target can execute applications for a different
2466 architecture in addition to those for the main target architecture.
2467 See the "Target Description Format" section in the user manual for
2470 * Multi-architecture debugging.
2472 GDB now includes general supports for debugging applications on
2473 hybrid systems that use more than one single processor architecture
2474 at the same time. Each such hybrid architecture still requires
2475 specific support to be added. The only hybrid architecture supported
2476 in this version of GDB is the Cell Broadband Engine.
2478 * GDB now supports integrated debugging of Cell/B.E. applications that
2479 use both the PPU and SPU architectures. To enable support for hybrid
2480 Cell/B.E. debugging, you need to configure GDB to support both the
2481 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2482 --enable-targets configure option.
2484 * Non-stop mode debugging.
2486 For some targets, GDB now supports an optional mode of operation in
2487 which you can examine stopped threads while other threads continue
2488 to execute freely. This is referred to as non-stop mode, with the
2489 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2490 section in the user manual for more information.
2492 To be able to support remote non-stop debugging, a remote stub needs
2493 to implement the non-stop mode remote protocol extensions, as
2494 described in the "Remote Non-Stop" section of the user manual. The
2495 GDB remote stub, gdbserver, has been adjusted to support these
2496 extensions on linux targets.
2498 * New commands (for set/show, see "New options" below)
2500 catch syscall [NAME(S) | NUMBER(S)]
2501 Catch system calls. Arguments, which should be names of system
2502 calls or their numbers, mean catch only those syscalls. Without
2503 arguments, every syscall will be caught. When the inferior issues
2504 any of the specified syscalls, GDB will stop and announce the system
2505 call, both when it is called and when its call returns. This
2506 feature is currently available with a native GDB running on the
2507 Linux Kernel, under the following architectures: x86, x86_64,
2508 PowerPC and PowerPC64.
2510 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2512 Search memory for a sequence of bytes.
2514 maint set python print-stack
2515 maint show python print-stack
2516 Show a stack trace when an error is encountered in a Python script.
2519 Invoke CODE by passing it to the Python interpreter.
2524 These allow macros to be defined, undefined, and listed
2528 Show operating system information about processes.
2531 List the inferiors currently under GDB's control.
2534 Switch focus to inferior number NUM.
2537 Detach from inferior number NUM.
2540 Kill inferior number NUM.
2544 set spu stop-on-load
2545 show spu stop-on-load
2546 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2548 set spu auto-flush-cache
2549 show spu auto-flush-cache
2550 Control whether to automatically flush the software-managed cache
2551 during Cell/B.E. debugging.
2553 set sh calling-convention
2554 show sh calling-convention
2555 Control the calling convention used when calling SH target functions.
2558 show debug timestamp
2559 Control display of timestamps with GDB debugging output.
2561 set disassemble-next-line
2562 show disassemble-next-line
2563 Control display of disassembled source lines or instructions when
2566 set remote noack-packet
2567 show remote noack-packet
2568 Set/show the use of remote protocol QStartNoAckMode packet. See above
2569 under "New remote packets."
2571 set remote query-attached-packet
2572 show remote query-attached-packet
2573 Control use of remote protocol `qAttached' (query-attached) packet.
2575 set remote read-siginfo-object
2576 show remote read-siginfo-object
2577 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2580 set remote write-siginfo-object
2581 show remote write-siginfo-object
2582 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2585 set remote reverse-continue
2586 show remote reverse-continue
2587 Control use of remote protocol 'bc' (reverse-continue) packet.
2589 set remote reverse-step
2590 show remote reverse-step
2591 Control use of remote protocol 'bs' (reverse-step) packet.
2593 set displaced-stepping
2594 show displaced-stepping
2595 Control displaced stepping mode. Displaced stepping is a way to
2596 single-step over breakpoints without removing them from the debuggee.
2597 Also known as "out-of-line single-stepping".
2600 show debug displaced
2601 Control display of debugging info for displaced stepping.
2603 maint set internal-error
2604 maint show internal-error
2605 Control what GDB does when an internal error is detected.
2607 maint set internal-warning
2608 maint show internal-warning
2609 Control what GDB does when an internal warning is detected.
2614 Use a wrapper program to launch programs for debugging.
2616 set multiple-symbols (all|ask|cancel)
2617 show multiple-symbols
2618 The value of this variable can be changed to adjust the debugger behavior
2619 when an expression or a breakpoint location contains an ambiguous symbol
2620 name (an overloaded function name, for instance).
2622 set breakpoint always-inserted
2623 show breakpoint always-inserted
2624 Keep breakpoints always inserted in the target, as opposed to inserting
2625 them when resuming the target, and removing them when the target stops.
2626 This option can improve debugger performance on slow remote targets.
2628 set arm fallback-mode (arm|thumb|auto)
2629 show arm fallback-mode
2630 set arm force-mode (arm|thumb|auto)
2632 These commands control how ARM GDB determines whether instructions
2633 are ARM or Thumb. The default for both settings is auto, which uses
2634 the current CPSR value for instructions without symbols; previous
2635 versions of GDB behaved as if "set arm fallback-mode arm".
2637 set disable-randomization
2638 show disable-randomization
2639 Standalone programs run with the virtual address space randomization enabled
2640 by default on some platforms. This option keeps the addresses stable across
2641 multiple debugging sessions.
2645 Control whether other threads are stopped or not when some thread hits
2650 Requests that asynchronous execution is enabled in the target, if available.
2651 In this case, it's possible to resume target in the background, and interact
2652 with GDB while the target is running. "show target-async" displays the
2653 current state of asynchronous execution of the target.
2655 set target-wide-charset
2656 show target-wide-charset
2657 The target-wide-charset is the name of the character set that GDB
2658 uses when printing characters whose type is wchar_t.
2660 set tcp auto-retry (on|off)
2662 set tcp connect-timeout
2663 show tcp connect-timeout
2664 These commands allow GDB to retry failed TCP connections to a remote stub
2665 with a specified timeout period; this is useful if the stub is launched
2666 in parallel with GDB but may not be ready to accept connections immediately.
2668 set libthread-db-search-path
2669 show libthread-db-search-path
2670 Control list of directories which GDB will search for appropriate
2673 set schedule-multiple (on|off)
2674 show schedule-multiple
2675 Allow GDB to resume all threads of all processes or only threads of
2676 the current process.
2680 Use more aggressive caching for accesses to the stack. This improves
2681 performance of remote debugging (particularly backtraces) without
2682 affecting correctness.
2684 set interactive-mode (on|off|auto)
2685 show interactive-mode
2686 Control whether GDB runs in interactive mode (on) or not (off).
2687 When in interactive mode, GDB waits for the user to answer all
2688 queries. Otherwise, GDB does not wait and assumes the default
2689 answer. When set to auto (the default), GDB determines which
2690 mode to use based on the stdin settings.
2695 For program forks, this is replaced by the new more generic `info
2696 inferiors' command. To list checkpoints, you can still use the
2697 `info checkpoints' command, which was an alias for the `info forks'
2701 Replaced by the new `inferior' command. To switch between
2702 checkpoints, you can still use the `restart' command, which was an
2703 alias for the `fork' command.
2706 This is removed, since some targets don't have a notion of
2707 processes. To switch between processes, you can still use the
2708 `inferior' command using GDB's own inferior number.
2711 For program forks, this is replaced by the new more generic `kill
2712 inferior' command. To delete a checkpoint, you can still use the
2713 `delete checkpoint' command, which was an alias for the `delete
2717 For program forks, this is replaced by the new more generic `detach
2718 inferior' command. To detach a checkpoint, you can still use the
2719 `detach checkpoint' command, which was an alias for the `detach
2722 * New native configurations
2724 x86/x86_64 Darwin i[34567]86-*-darwin*
2726 x86_64 MinGW x86_64-*-mingw*
2730 Lattice Mico32 lm32-*
2731 x86 DICOS i[34567]86-*-dicos*
2732 x86_64 DICOS x86_64-*-dicos*
2735 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2736 (mingw32ce) debugging.
2742 These commands were actually not implemented on any target.
2744 *** Changes in GDB 6.8
2746 * New native configurations
2748 NetBSD/hppa hppa*-*netbsd*
2749 Xtensa GNU/Linux xtensa*-*-linux*
2753 NetBSD/hppa hppa*-*-netbsd*
2754 Xtensa GNU/Lunux xtensa*-*-linux*
2756 * Change in command line behavior -- corefiles vs. process ids.
2758 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2759 attaching to process NUMBER fails, GDB no longer attempts to open a
2760 core file named NUMBER. Attaching to a program using the -c option
2761 is no longer supported. Instead, use the '-p' or '--pid' options.
2763 * GDB can now be built as a native debugger for debugging Windows x86
2764 (mingw32) Portable Executable (PE) programs.
2766 * Pending breakpoints no longer change their number when their address
2769 * GDB now supports breakpoints with multiple locations,
2770 including breakpoints on C++ constructors, inside C++ templates,
2771 and in inlined functions.
2773 * GDB's ability to debug optimized code has been improved. GDB more
2774 accurately identifies function bodies and lexical blocks that occupy
2775 more than one contiguous range of addresses.
2777 * Target descriptions can now describe registers for PowerPC.
2779 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2780 registers on PowerPC targets.
2782 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2783 targets even when the libthread_db library is not available.
2785 * The GDB remote stub, gdbserver, now supports the new file transfer
2786 commands (remote put, remote get, and remote delete).
2788 * The GDB remote stub, gdbserver, now supports run and attach in
2789 extended-remote mode.
2791 * hppa*64*-*-hpux11* target broken
2792 The debugger is unable to start a program and fails with the following
2793 error: "Error trying to get information about dynamic linker".
2794 The gdb-6.7 release is also affected.
2796 * GDB now supports the --enable-targets= configure option to allow
2797 building a single GDB executable that supports multiple remote
2798 target architectures.
2800 * GDB now supports debugging C and C++ programs which use the
2801 Decimal Floating Point extension. In addition, the PowerPC target
2802 now has a set of pseudo-registers to inspect decimal float values
2803 stored in two consecutive float registers.
2805 * The -break-insert MI command can optionally create pending
2808 * Improved support for debugging Ada
2809 Many improvements to the Ada language support have been made. These
2811 - Better support for Ada2005 interface types
2812 - Improved handling of arrays and slices in general
2813 - Better support for Taft-amendment types
2814 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2816 - Improved command completion in Ada
2819 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2824 set print frame-arguments (all|scalars|none)
2825 show print frame-arguments
2826 The value of this variable can be changed to control which argument
2827 values should be printed by the debugger when displaying a frame.
2832 Transfer files to and from a remote target, and delete remote files.
2839 Transfer files to and from a remote target, and delete remote files.
2841 * New remote packets
2848 Open, close, read, write, and delete files on the remote system.
2851 Attach to an existing process on the remote system, in extended-remote
2855 Run a new process on the remote system, in extended-remote mode.
2857 *** Changes in GDB 6.7
2859 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2860 bfd, libiberty and opcodes, as revealed by static analysis donated by
2861 Coverity, Inc. (http://scan.coverity.com).
2863 * When looking up multiply-defined global symbols, GDB will now prefer the
2864 symbol definition in the current shared library if it was built using the
2865 -Bsymbolic linker option.
2867 * When the Text User Interface (TUI) is not configured, GDB will now
2868 recognize the -tui command-line option and print a message that the TUI
2871 * The GDB remote stub, gdbserver, now has lower overhead for high
2872 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2874 * GDB for MIPS targets now autodetects whether a remote target provides
2875 32-bit or 64-bit register values.
2877 * Support for C++ member pointers has been improved.
2879 * GDB now understands XML target descriptions, which specify the
2880 target's overall architecture. GDB can read a description from
2881 a local file or over the remote serial protocol.
2883 * Vectors of single-byte data use a new integer type which is not
2884 automatically displayed as character or string data.
2886 * The /s format now works with the print command. It displays
2887 arrays of single-byte integers and pointers to single-byte integers
2890 * Target descriptions can now describe target-specific registers,
2891 for architectures which have implemented the support (currently
2892 only ARM, M68K, and MIPS).
2894 * GDB and the GDB remote stub, gdbserver, now support the XScale
2897 * The GDB remote stub, gdbserver, has been updated to support
2898 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2899 has been rewritten to use the standard GDB remote protocol.
2901 * GDB can now step into C++ functions which are called through thunks.
2903 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2905 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2906 layout. It also supports a TextSeg= and DataSeg= response when only
2907 segment base addresses (rather than offsets) are available.
2909 * The /i format now outputs any trailing branch delay slot instructions
2910 immediately following the last instruction within the count specified.
2912 * The GDB remote protocol "T" stop reply packet now supports a
2913 "library" response. Combined with the new "qXfer:libraries:read"
2914 packet, this response allows GDB to debug shared libraries on targets
2915 where the operating system manages the list of loaded libraries (e.g.
2916 Windows and SymbianOS).
2918 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2919 (DLLs) on Windows and Windows CE targets.
2921 * GDB now supports a faster verification that a .debug file matches its binary
2922 according to its build-id signature, if the signature is present.
2928 Enable or disable hardware flow control (RTS/CTS) on the serial port
2929 when debugging using remote targets.
2931 set mem inaccessible-by-default
2932 show mem inaccessible-by-default
2933 If the target supplies a memory map, for instance via the remote
2934 protocol's "qXfer:memory-map:read" packet, setting this variable
2935 prevents GDB from accessing memory outside the memory map. This
2936 is useful for targets with memory mapped registers or which react
2937 badly to accesses of unmapped address space.
2939 set breakpoint auto-hw
2940 show breakpoint auto-hw
2941 If the target supplies a memory map, for instance via the remote
2942 protocol's "qXfer:memory-map:read" packet, setting this variable
2943 lets GDB use hardware breakpoints automatically for memory regions
2944 where it can not use software breakpoints. This covers both the
2945 "break" command and internal breakpoints used for other commands
2946 including "next" and "finish".
2949 catch exception unhandled
2950 Stop the program execution when Ada exceptions are raised.
2953 Stop the program execution when an Ada assertion failed.
2957 Set an alternate system root for target files. This is a more
2958 general version of "set solib-absolute-prefix", which is now
2959 an alias to "set sysroot".
2962 Provide extended SPU facility status information. This set of
2963 commands is available only when debugging the Cell/B.E. SPU
2966 * New native configurations
2968 OpenBSD/sh sh*-*openbsd*
2971 unset tdesc filename
2973 Use the specified local file as an XML target description, and do
2974 not query the target for its built-in description.
2978 OpenBSD/sh sh*-*-openbsd*
2979 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2980 Toshiba Media Processor mep-elf
2982 * New remote packets
2985 Ignore the specified signals; pass them directly to the debugged program
2986 without stopping other threads or reporting them to GDB.
2988 qXfer:features:read:
2989 Read an XML target description from the target, which describes its
2994 Read or write contents of an spufs file on the target system. These
2995 packets are available only on the Cell/B.E. SPU architecture.
2997 qXfer:libraries:read:
2998 Report the loaded shared libraries. Combined with new "T" packet
2999 response, this packet allows GDB to debug shared libraries on
3000 targets where the operating system manages the list of loaded
3001 libraries (e.g. Windows and SymbianOS).
3005 Support for these obsolete configurations has been removed.
3013 i[34567]86-*-lynxos*
3014 i[34567]86-*-netware*
3015 i[34567]86-*-sco3.2v5*
3016 i[34567]86-*-sco3.2v4*
3018 i[34567]86-*-sysv4.2*
3021 i[34567]86-*-unixware2*
3022 i[34567]86-*-unixware*
3031 * Other removed features
3038 Various m68k-only ROM monitors.
3045 Various Renesas ROM monitors and debugging interfaces for SH and
3050 Support for a Macraigor serial interface to on-chip debugging.
3051 GDB does not directly support the newer parallel or USB
3056 A debug information format. The predecessor to DWARF 2 and
3057 DWARF 3, which are still supported.
3059 Support for the HP aCC compiler on HP-UX/PA-RISC
3061 SOM-encapsulated symbolic debugging information, automatic
3062 invocation of pxdb, and the aCC custom C++ ABI. This does not
3063 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3064 with aCC can still be debugged on an assembly level.
3066 MIPS ".pdr" sections
3068 A MIPS-specific format used to describe stack frame layout
3069 in debugging information.
3073 GDB could work with an older version of Guile to debug
3074 the interpreter and Scheme programs running in it.
3076 set mips stack-arg-size
3077 set mips saved-gpreg-size
3079 Use "set mips abi" to control parameter passing for MIPS.
3081 *** Changes in GDB 6.6
3086 Cell Broadband Engine SPU spu-elf
3088 * GDB can now be configured as a cross-debugger targeting native Windows
3089 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3090 running on a Windows system over TCP/IP to debug Windows programs.
3092 * The GDB remote stub, gdbserver, has been updated to support Windows and
3093 Cygwin debugging. Both single-threaded and multi-threaded programs are
3096 * The "set trust-readonly-sections" command works again. This command was
3097 broken in GDB 6.3, 6.4, and 6.5.
3099 * The "load" command now supports writing to flash memory, if the remote
3100 stub provides the required support.
3102 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3103 longer requires symbolic debug information (e.g. DWARF-2).
3108 unset substitute-path
3109 show substitute-path
3110 Manage a list of substitution rules that GDB uses to rewrite the name
3111 of the directories where the sources are located. This can be useful
3112 for instance when the sources were moved to a different location
3113 between compilation and debugging.
3117 Print each CLI command as it is executed. Each command is prefixed with
3118 a number of `+' symbols representing the nesting depth.
3119 The source command now has a `-v' option to enable the same feature.
3123 The ARM Demon monitor support (RDP protocol, "target rdp").
3125 Kernel Object Display, an embedded debugging feature which only worked with
3126 an obsolete version of Cisco IOS.
3128 The 'set download-write-size' and 'show download-write-size' commands.
3130 * New remote packets
3133 Tell a stub about GDB client features, and request remote target features.
3134 The first feature implemented is PacketSize, which allows the target to
3135 specify the size of packets it can handle - to minimize the number of
3136 packets required and improve performance when connected to a remote
3140 Fetch an OS auxilliary vector from the remote stub. This packet is a
3141 more efficient replacement for qPart:auxv:read.
3143 qXfer:memory-map:read:
3144 Fetch a memory map from the remote stub, including information about
3145 RAM, ROM, and flash memory devices.
3150 Erase and program a flash memory device.
3152 * Removed remote packets
3155 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3156 used it, and only gdbserver implemented it.
3158 *** Changes in GDB 6.5
3162 Renesas M32C/M16C m32c-elf
3164 Morpho Technologies ms1 ms1-elf
3168 init-if-undefined Initialize a convenience variable, but
3169 only if it doesn't already have a value.
3171 The following commands are presently only implemented for native GNU/Linux:
3173 checkpoint Save a snapshot of the program state.
3175 restart <n> Return the program state to a
3176 previously saved state.
3178 info checkpoints List currently saved checkpoints.
3180 delete-checkpoint <n> Delete a previously saved checkpoint.
3182 set|show detach-on-fork Tell gdb whether to detach from a newly
3183 forked process, or to keep debugging it.
3185 info forks List forks of the user program that
3186 are available to be debugged.
3188 fork <n> Switch to debugging one of several
3189 forks of the user program that are
3190 available to be debugged.
3192 delete-fork <n> Delete a fork from the list of forks
3193 that are available to be debugged (and
3194 kill the forked process).
3196 detach-fork <n> Delete a fork from the list of forks
3197 that are available to be debugged (and
3198 allow the process to continue).
3202 Morpho Technologies ms2 ms1-elf
3204 * Improved Windows host support
3206 GDB now builds as a cross debugger hosted on i686-mingw32, including
3207 native console support, and remote communications using either
3208 network sockets or serial ports.
3210 * Improved Modula-2 language support
3212 GDB can now print most types in the Modula-2 syntax. This includes:
3213 basic types, set types, record types, enumerated types, range types,
3214 pointer types and ARRAY types. Procedure var parameters are correctly
3215 printed and hexadecimal addresses and character constants are also
3216 written in the Modula-2 syntax. Best results can be obtained by using
3217 GNU Modula-2 together with the -gdwarf-2 command line option.
3221 The ARM rdi-share module.
3223 The Netware NLM debug server.
3225 *** Changes in GDB 6.4
3227 * New native configurations
3229 OpenBSD/arm arm*-*-openbsd*
3230 OpenBSD/mips64 mips64-*-openbsd*
3234 Morpho Technologies ms1 ms1-elf
3236 * New command line options
3238 --batch-silent As for --batch, but totally silent.
3239 --return-child-result The debugger will exist with the same value
3240 the child (debugged) program exited with.
3241 --eval-command COMMAND, -ex COMMAND
3242 Execute a single GDB CLI command. This may be
3243 specified multiple times and in conjunction
3244 with the --command (-x) option.
3246 * Deprecated commands removed
3248 The following commands, that were deprecated in 2000, have been
3252 set|show arm disassembly-flavor set|show arm disassembler
3253 othernames set arm disassembler
3254 set|show remotedebug set|show debug remote
3255 set|show archdebug set|show debug arch
3256 set|show eventdebug set|show debug event
3259 * New BSD user-level threads support
3261 It is now possible to debug programs using the user-level threads
3262 library on OpenBSD and FreeBSD. Currently supported (target)
3265 FreeBSD/amd64 x86_64-*-freebsd*
3266 FreeBSD/i386 i386-*-freebsd*
3267 OpenBSD/i386 i386-*-openbsd*
3269 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3270 are not yet supported.
3272 * New support for Matsushita MN10300 w/sim added
3273 (Work in progress). mn10300-elf.
3275 * REMOVED configurations and files
3277 VxWorks and the XDR protocol *-*-vxworks
3278 Motorola MCORE mcore-*-*
3279 National Semiconductor NS32000 ns32k-*-*
3281 * New "set print array-indexes" command
3283 After turning this setting "on", GDB prints the index of each element
3284 when displaying arrays. The default is "off" to preserve the previous
3287 * VAX floating point support
3289 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3291 * User-defined command support
3293 In addition to using $arg0..$arg9 for argument passing, it is now possible
3294 to use $argc to determine now many arguments have been passed. See the
3295 section on user-defined commands in the user manual for more information.
3297 *** Changes in GDB 6.3:
3299 * New command line option
3301 GDB now accepts -l followed by a number to set the timeout for remote
3304 * GDB works with GCC -feliminate-dwarf2-dups
3306 GDB now supports a more compact representation of DWARF-2 debug
3307 information using DW_FORM_ref_addr references. These are produced
3308 by GCC with the option -feliminate-dwarf2-dups and also by some
3309 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3310 to use -feliminate-dwarf2-dups.
3312 * Internationalization
3314 When supported by the host system, GDB will be built with
3315 internationalization (libintl). The task of marking up the sources is
3316 continued, we're looking forward to our first translation.
3320 Initial support for debugging programs compiled with the GNAT
3321 implementation of the Ada programming language has been integrated
3322 into GDB. In this release, support is limited to expression evaluation.
3324 * New native configurations
3326 GNU/Linux/m32r m32r-*-linux-gnu
3330 GDB's remote protocol now includes support for the 'p' packet. This
3331 packet is used to fetch individual registers from a remote inferior.
3333 * END-OF-LIFE registers[] compatibility module
3335 GDB's internal register infrastructure has been completely rewritten.
3336 The new infrastructure making possible the implementation of key new
3337 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3340 GDB 6.3 will be the last release to include the the registers[]
3341 compatibility module that allowed out-of-date configurations to
3342 continue to work. This change directly impacts the following
3352 powerpc bdm protocol
3354 Unless there is activity to revive these configurations, they will be
3355 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3357 * OBSOLETE configurations and files
3359 Configurations that have been declared obsolete in this release have
3360 been commented out. Unless there is activity to revive these
3361 configurations, the next release of GDB will have their sources
3362 permanently REMOVED.
3371 *** Changes in GDB 6.2.1:
3373 * MIPS `break main; run' gave an heuristic-fence-post warning
3375 When attempting to run even a simple program, a warning about
3376 heuristic-fence-post being hit would be reported. This problem has
3379 * MIPS IRIX 'long double' crashed GDB
3381 When examining a long double variable, GDB would get a segmentation
3382 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3383 IRIX long double values).
3387 A bug in the VAX stack code was causing problems with the "next"
3388 command. This problem has been fixed.
3390 *** Changes in GDB 6.2:
3392 * Fix for ``many threads''
3394 On GNU/Linux systems that use the NPTL threads library, a program
3395 rapidly creating and deleting threads would confuse GDB leading to the
3398 ptrace: No such process.
3399 thread_db_get_info: cannot get thread info: generic error
3401 This problem has been fixed.
3403 * "-async" and "-noasync" options removed.
3405 Support for the broken "-noasync" option has been removed (it caused
3408 * New ``start'' command.
3410 This command runs the program until the begining of the main procedure.
3412 * New BSD Kernel Data Access Library (libkvm) interface
3414 Using ``target kvm'' it is now possible to debug kernel core dumps and
3415 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3416 platforms. Currently supported (native-only) configurations are:
3418 FreeBSD/amd64 x86_64-*-freebsd*
3419 FreeBSD/i386 i?86-*-freebsd*
3420 NetBSD/i386 i?86-*-netbsd*
3421 NetBSD/m68k m68*-*-netbsd*
3422 NetBSD/sparc sparc-*-netbsd*
3423 OpenBSD/amd64 x86_64-*-openbsd*
3424 OpenBSD/i386 i?86-*-openbsd*
3425 OpenBSD/m68k m68*-openbsd*
3426 OpenBSD/sparc sparc-*-openbsd*
3428 * Signal trampoline code overhauled
3430 Many generic problems with GDB's signal handling code have been fixed.
3431 These include: backtraces through non-contiguous stacks; recognition
3432 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3433 call; backtrace through a signal trampoline; step into and out of
3434 signal handlers; and single-stepping in the signal trampoline.
3436 Please note that kernel bugs are a limiting factor here. These
3437 features have been shown to work on an s390 GNU/Linux system that
3438 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3440 * Cygwin support for DWARF 2 added.
3442 * New native configurations
3444 GNU/Linux/hppa hppa*-*-linux*
3445 OpenBSD/hppa hppa*-*-openbsd*
3446 OpenBSD/m68k m68*-*-openbsd*
3447 OpenBSD/m88k m88*-*-openbsd*
3448 OpenBSD/powerpc powerpc-*-openbsd*
3449 NetBSD/vax vax-*-netbsd*
3450 OpenBSD/vax vax-*-openbsd*
3452 * END-OF-LIFE frame compatibility module
3454 GDB's internal frame infrastructure has been completely rewritten.
3455 The new infrastructure making it possible to support key new features
3456 including DWARF 2 Call Frame Information. To aid in the task of
3457 migrating old configurations to this new infrastructure, a
3458 compatibility module, that allowed old configurations to continue to
3459 work, was also included.
3461 GDB 6.2 will be the last release to include this frame compatibility
3462 module. This change directly impacts the following configurations:
3472 Unless there is activity to revive these configurations, they will be
3473 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3475 * REMOVED configurations and files
3477 Sun 3, running SunOS 3 m68*-*-sunos3*
3478 Sun 3, running SunOS 4 m68*-*-sunos4*
3479 Sun 2, running SunOS 3 m68000-*-sunos3*
3480 Sun 2, running SunOS 4 m68000-*-sunos4*
3481 Motorola 680x0 running LynxOS m68*-*-lynxos*
3482 AT&T 3b1/Unix pc m68*-att-*
3483 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3484 decstation mips-dec-* mips-little-*
3485 riscos mips-*-riscos* mips-*-sysv*
3486 sonymips mips-sony-*
3487 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3489 *** Changes in GDB 6.1.1:
3491 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3493 The TUI (Text-mode User Interface) is now built as part of a default
3494 GDB configuration. It is enabled by either selecting the TUI with the
3495 command line option "-i=tui" or by running the separate "gdbtui"
3496 program. For more information on the TUI, see the manual "Debugging
3499 * Pending breakpoint support (also included in GDB 6.1)
3501 Support has been added to allow you to specify breakpoints in shared
3502 libraries that have not yet been loaded. If a breakpoint location
3503 cannot be found, and the "breakpoint pending" option is set to auto,
3504 GDB queries you if you wish to make the breakpoint pending on a future
3505 shared-library load. If and when GDB resolves the breakpoint symbol,
3506 the pending breakpoint is removed as one or more regular breakpoints
3509 Pending breakpoints are very useful for GCJ Java debugging.
3511 * Fixed ISO-C build problems
3513 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3514 non ISO-C code that stopped them being built using a more strict ISO-C
3515 compiler (e.g., IBM's C compiler).
3517 * Fixed build problem on IRIX 5
3519 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3520 wasn't able to compile compile on an IRIX 5 system.
3522 * Added execute permission to gdb/gdbserver/configure
3524 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3525 permission. This bug would cause configure to fail on a number of
3526 systems (Solaris, IRIX). Ref: server/519.
3528 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3530 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3531 has been updated to use constant array sizes.
3533 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3535 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3536 its generated DWARF Call Frame Info. This encoding was causing GDB to
3537 panic, that panic has been fixed. Ref: gdb/1628.
3539 * Fixed a problem when examining parameters in shared library code.
3541 When examining parameters in optimized shared library code generated
3542 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3543 not available''. GDB now correctly displays the variable's value.
3545 *** Changes in GDB 6.1:
3547 * Removed --with-mmalloc
3549 Support for the mmalloc memory manager has been removed, as it
3550 conflicted with the internal gdb byte cache.
3552 * Changes in AMD64 configurations
3554 The AMD64 target now includes the %cs and %ss registers. As a result
3555 the AMD64 remote protocol has changed; this affects the floating-point
3556 and SSE registers. If you rely on those registers for your debugging,
3557 you should upgrade gdbserver on the remote side.
3559 * Revised SPARC target
3561 The SPARC target has been completely revised, incorporating the
3562 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3563 support for LynxOS and SunOS 4 has been dropped. Calling functions
3564 from within GDB on operating systems with a non-executable stack
3565 (Solaris, OpenBSD) now works.
3569 GDB has a new C++ demangler which does a better job on the mangled
3570 names generated by current versions of g++. It also runs faster, so
3571 with this and other changes gdb should now start faster on large C++
3574 * DWARF 2 Location Expressions
3576 GDB support for location expressions has been extended to support function
3577 arguments and frame bases. Older versions of GDB could crash when they
3580 * C++ nested types and namespaces
3582 GDB's support for nested types and namespaces in C++ has been
3583 improved, especially if you use the DWARF 2 debugging format. (This
3584 is the default for recent versions of GCC on most platforms.)
3585 Specifically, if you have a class "Inner" defined within a class or
3586 namespace "Outer", then GDB realizes that the class's name is
3587 "Outer::Inner", not simply "Inner". This should greatly reduce the
3588 frequency of complaints about not finding RTTI symbols. In addition,
3589 if you are stopped at inside of a function defined within a namespace,
3590 GDB modifies its name lookup accordingly.
3592 * New native configurations
3594 NetBSD/amd64 x86_64-*-netbsd*
3595 OpenBSD/amd64 x86_64-*-openbsd*
3596 OpenBSD/alpha alpha*-*-openbsd*
3597 OpenBSD/sparc sparc-*-openbsd*
3598 OpenBSD/sparc64 sparc64-*-openbsd*
3600 * New debugging protocols
3602 M32R with SDI protocol m32r-*-elf*
3604 * "set prompt-escape-char" command deleted.
3606 The command "set prompt-escape-char" has been deleted. This command,
3607 and its very obscure effet on GDB's prompt, was never documented,
3608 tested, nor mentioned in the NEWS file.
3610 * OBSOLETE configurations and files
3612 Configurations that have been declared obsolete in this release have
3613 been commented out. Unless there is activity to revive these
3614 configurations, the next release of GDB will have their sources
3615 permanently REMOVED.
3617 Sun 3, running SunOS 3 m68*-*-sunos3*
3618 Sun 3, running SunOS 4 m68*-*-sunos4*
3619 Sun 2, running SunOS 3 m68000-*-sunos3*
3620 Sun 2, running SunOS 4 m68000-*-sunos4*
3621 Motorola 680x0 running LynxOS m68*-*-lynxos*
3622 AT&T 3b1/Unix pc m68*-att-*
3623 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3624 decstation mips-dec-* mips-little-*
3625 riscos mips-*-riscos* mips-*-sysv*
3626 sonymips mips-sony-*
3627 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3629 * REMOVED configurations and files
3631 SGI Irix-4.x mips-sgi-irix4 or iris4
3632 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3633 Z8000 simulator z8k-zilog-none or z8ksim
3634 Matsushita MN10200 w/simulator mn10200-*-*
3635 H8/500 simulator h8500-hitachi-hms or h8500hms
3636 HP/PA running BSD hppa*-*-bsd*
3637 HP/PA running OSF/1 hppa*-*-osf*
3638 HP/PA Pro target hppa*-*-pro*
3639 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3640 386BSD i[3456]86-*-bsd*
3641 Sequent family i[3456]86-sequent-sysv4*
3642 i[3456]86-sequent-sysv*
3643 i[3456]86-sequent-bsd*
3644 SPARC running LynxOS sparc-*-lynxos*
3645 SPARC running SunOS 4 sparc-*-sunos4*
3646 Tsqware Sparclet sparclet-*-*
3647 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3649 *** Changes in GDB 6.0:
3653 Support for debugging the Objective-C programming language has been
3654 integrated into GDB.
3656 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3658 DWARF 2's Call Frame Information makes available compiler generated
3659 information that more exactly describes the program's run-time stack.
3660 By using this information, GDB is able to provide more robust stack
3663 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3664 have been updated to use a new backtrace mechanism which includes
3665 DWARF 2 CFI support.
3669 GDB's remote protocol has been extended to include support for hosted
3670 file I/O (where the remote target uses GDB's file system). See GDB's
3671 remote protocol documentation for details.
3673 * All targets using the new architecture framework.
3675 All of GDB's targets have been updated to use the new internal
3676 architecture framework. The way is now open for future GDB releases
3677 to include cross-architecture native debugging support (i386 on amd64,
3680 * GNU/Linux's Thread Local Storage (TLS)
3682 GDB now includes support for for the GNU/Linux implementation of
3683 per-thread variables.
3685 * GNU/Linux's Native POSIX Thread Library (NPTL)
3687 GDB's thread code has been updated to work with either the new
3688 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3690 * Separate debug info.
3692 GDB, in conjunction with BINUTILS, now supports a mechanism for
3693 automatically loading debug information from a separate file. Instead
3694 of shipping full debug and non-debug versions of system libraries,
3695 system integrators can now instead ship just the stripped libraries
3696 and optional debug files.
3698 * DWARF 2 Location Expressions
3700 DWARF 2 Location Expressions allow the compiler to more completely
3701 describe the location of variables (even in optimized code) to the
3704 GDB now includes preliminary support for location expressions (support
3705 for DW_OP_piece is still missing).
3709 A number of long standing bugs that caused GDB to die while starting a
3710 Java application have been fixed. GDB's Java support is now
3711 considered "useable".
3713 * GNU/Linux support for fork, vfork, and exec.
3715 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3716 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3719 * GDB supports logging output to a file
3721 There are two new commands, "set logging" and "show logging", which can be
3722 used to capture GDB's output to a file.
3724 * The meaning of "detach" has changed for gdbserver
3726 The "detach" command will now resume the application, as documented. To
3727 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3730 * d10v, m68hc11 `regs' command deprecated
3732 The `info registers' command has been updated so that it displays the
3733 registers using a format identical to the old `regs' command.
3737 A new command, "maint set profile on/off", has been added. This command can
3738 be used to enable or disable profiling while running GDB, to profile a
3739 session or a set of commands. In addition there is a new configure switch,
3740 "--enable-profiling", which will cause GDB to be compiled with profiling
3741 data, for more informative profiling results.
3743 * Default MI syntax changed to "mi2".
3745 The default MI (machine interface) syntax, enabled by the command line
3746 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3747 "mi1", can be enabled by specifying the option "-i=mi1".
3749 Support for the original "mi0" syntax (included in GDB 5.0) has been
3752 Fix for gdb/192: removed extraneous space when displaying frame level.
3753 Fix for gdb/672: update changelist is now output in mi list format.
3754 Fix for gdb/702: a -var-assign that updates the value now shows up
3755 in a subsequent -var-update.
3757 * New native configurations.
3759 FreeBSD/amd64 x86_64-*-freebsd*
3761 * Multi-arched targets.
3763 HP/PA HPUX11 hppa*-*-hpux*
3764 Renesas M32R/D w/simulator m32r-*-elf*
3766 * OBSOLETE configurations and files
3768 Configurations that have been declared obsolete in this release have
3769 been commented out. Unless there is activity to revive these
3770 configurations, the next release of GDB will have their sources
3771 permanently REMOVED.
3773 Z8000 simulator z8k-zilog-none or z8ksim
3774 Matsushita MN10200 w/simulator mn10200-*-*
3775 H8/500 simulator h8500-hitachi-hms or h8500hms
3776 HP/PA running BSD hppa*-*-bsd*
3777 HP/PA running OSF/1 hppa*-*-osf*
3778 HP/PA Pro target hppa*-*-pro*
3779 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3780 Sequent family i[3456]86-sequent-sysv4*
3781 i[3456]86-sequent-sysv*
3782 i[3456]86-sequent-bsd*
3783 Tsqware Sparclet sparclet-*-*
3784 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3786 * REMOVED configurations and files
3789 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3790 IBM AIX PS/2 i[3456]86-*-aix
3791 i386 running Mach 3.0 i[3456]86-*-mach3*
3792 i386 running Mach i[3456]86-*-mach*
3793 i386 running OSF/1 i[3456]86-*osf1mk*
3794 HP/Apollo 68k Family m68*-apollo*-sysv*,
3796 m68*-hp-bsd*, m68*-hp-hpux*
3797 Argonaut Risc Chip (ARC) arc-*-*
3798 Mitsubishi D30V d30v-*-*
3799 Fujitsu FR30 fr30-*-elf*
3800 OS/9000 i[34]86-*-os9k
3801 I960 with MON960 i960-*-coff
3803 * MIPS $fp behavior changed
3805 The convenience variable $fp, for the MIPS, now consistently returns
3806 the address of the current frame's base. Previously, depending on the
3807 context, $fp could refer to either $sp or the current frame's base
3808 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3809 The GNU Source-Level Debugger''.
3811 *** Changes in GDB 5.3:
3813 * GNU/Linux shared library multi-threaded performance improved.
3815 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3816 `/proc', in preference to `ptrace' for memory reads. This may result
3817 in an improvement in the start-up time of multi-threaded, shared
3818 library applications when run under GDB. One GDB user writes: ``loads
3819 shared libs like mad''.
3821 * ``gdbserver'' now supports multi-threaded applications on some targets
3823 Support for debugging multi-threaded applications which use
3824 the GNU/Linux LinuxThreads package has been added for
3825 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3826 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3828 * GDB now supports C/C++ preprocessor macros.
3830 GDB now expands preprocessor macro invocations in C/C++ expressions,
3831 and provides various commands for showing macro definitions and how
3834 The new command `macro expand EXPRESSION' expands any macro
3835 invocations in expression, and shows the result.
3837 The new command `show macro MACRO-NAME' shows the definition of the
3838 macro named MACRO-NAME, and where it was defined.
3840 Most compilers don't include information about macros in the debugging
3841 information by default. In GCC 3.1, for example, you need to compile
3842 your program with the options `-gdwarf-2 -g3'. If the macro
3843 information is present in the executable, GDB will read it.
3845 * Multi-arched targets.
3847 DEC Alpha (partial) alpha*-*-*
3848 DEC VAX (partial) vax-*-*
3850 National Semiconductor NS32000 (partial) ns32k-*-*
3851 Motorola 68000 (partial) m68k-*-*
3852 Motorola MCORE mcore-*-*
3856 Fujitsu FRV architecture added by Red Hat frv*-*-*
3859 * New native configurations
3861 Alpha NetBSD alpha*-*-netbsd*
3862 SH NetBSD sh*-*-netbsdelf*
3863 MIPS NetBSD mips*-*-netbsd*
3864 UltraSPARC NetBSD sparc64-*-netbsd*
3866 * OBSOLETE configurations and files
3868 Configurations that have been declared obsolete in this release have
3869 been commented out. Unless there is activity to revive these
3870 configurations, the next release of GDB will have their sources
3871 permanently REMOVED.
3873 Mitsubishi D30V d30v-*-*
3874 OS/9000 i[34]86-*-os9k
3875 IBM AIX PS/2 i[3456]86-*-aix
3876 Fujitsu FR30 fr30-*-elf*
3877 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3878 Argonaut Risc Chip (ARC) arc-*-*
3879 i386 running Mach 3.0 i[3456]86-*-mach3*
3880 i386 running Mach i[3456]86-*-mach*
3881 i386 running OSF/1 i[3456]86-*osf1mk*
3882 HP/Apollo 68k Family m68*-apollo*-sysv*,
3884 m68*-hp-bsd*, m68*-hp-hpux*
3885 I960 with MON960 i960-*-coff
3887 * OBSOLETE languages
3889 CHILL, a Pascal like language used by telecommunications companies.
3891 * REMOVED configurations and files
3893 AMD 29k family via UDI a29k-amd-udi, udi29k
3894 A29K VxWorks a29k-*-vxworks
3895 AMD 29000 embedded, using EBMON a29k-none-none
3896 AMD 29000 embedded with COFF a29k-none-coff
3897 AMD 29000 embedded with a.out a29k-none-aout
3899 testsuite/gdb.hp/gdb.threads-hp/ directory
3901 * New command "set max-user-call-depth <nnn>"
3903 This command allows the user to limit the call depth of user-defined
3904 commands. The default is 1024.
3906 * Changes in FreeBSD/i386 native debugging.
3908 Support for the "generate-core-file" has been added.
3910 * New commands "dump", "append", and "restore".
3912 These commands allow data to be copied from target memory
3913 to a bfd-format or binary file (dump and append), and back
3914 from a file into memory (restore).
3916 * Improved "next/step" support on multi-processor Alpha Tru64.
3918 The previous single-step mechanism could cause unpredictable problems,
3919 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3920 of a software single-step mechanism prevents this.
3922 *** Changes in GDB 5.2.1:
3930 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3931 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3932 Fix, by Joel Brobecker imported from mainline.
3934 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3935 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3936 Fix, by Fred Fish, imported from mainline.
3938 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3939 Surprisingly enough, it works now.
3940 By Michal Ludvig, imported from mainline.
3942 i386 hardware watchpoint support:
3943 avoid misses on second run for some targets.
3944 By Pierre Muller, imported from mainline.
3946 *** Changes in GDB 5.2:
3948 * New command "set trust-readonly-sections on[off]".
3950 This command is a hint that tells gdb that read-only sections
3951 really are read-only (ie. that their contents will not change).
3952 In this mode, gdb will go to the object file rather than the
3953 target to read memory from read-only sections (such as ".text").
3954 This can be a significant performance improvement on some
3955 (notably embedded) targets.
3957 * New command "generate-core-file" (or "gcore").
3959 This new gdb command allows the user to drop a core file of the child
3960 process state at any time. So far it's been implemented only for
3961 GNU/Linux and Solaris, but should be relatively easily ported to other
3962 hosts. Argument is core file name (defaults to core.<pid>).
3964 * New command line option
3966 GDB now accepts --pid or -p followed by a process id.
3968 * Change in command line behavior -- corefiles vs. process ids.
3970 There is a subtle behavior in the way in which GDB handles
3971 command line arguments. The first non-flag argument is always
3972 a program to debug, but the second non-flag argument may either
3973 be a corefile or a process id. Previously, GDB would attempt to
3974 open the second argument as a corefile, and if that failed, would
3975 issue a superfluous error message and then attempt to attach it as
3976 a process. Now, if the second argument begins with a non-digit,
3977 it will be treated as a corefile. If it begins with a digit,
3978 GDB will attempt to attach it as a process, and if no such process
3979 is found, will then attempt to open it as a corefile.
3981 * Changes in ARM configurations.
3983 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3984 configuration is fully multi-arch.
3986 * New native configurations
3988 ARM NetBSD arm*-*-netbsd*
3989 x86 OpenBSD i[3456]86-*-openbsd*
3990 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3991 Sparc64 running FreeBSD sparc64-*-freebsd*
3995 Sanyo XStormy16 xstormy16-elf
3997 * OBSOLETE configurations and files
3999 Configurations that have been declared obsolete in this release have
4000 been commented out. Unless there is activity to revive these
4001 configurations, the next release of GDB will have their sources
4002 permanently REMOVED.
4004 AMD 29k family via UDI a29k-amd-udi, udi29k
4005 A29K VxWorks a29k-*-vxworks
4006 AMD 29000 embedded, using EBMON a29k-none-none
4007 AMD 29000 embedded with COFF a29k-none-coff
4008 AMD 29000 embedded with a.out a29k-none-aout
4010 testsuite/gdb.hp/gdb.threads-hp/ directory
4012 * REMOVED configurations and files
4014 TI TMS320C80 tic80-*-*
4016 PowerPC Solaris powerpcle-*-solaris*
4017 PowerPC Windows NT powerpcle-*-cygwin32
4018 PowerPC Netware powerpc-*-netware*
4019 Harris/CXUX m88k m88*-harris-cxux*
4020 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4021 ns32k-utek-sysv* ns32k-utek-*
4022 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4023 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4024 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4025 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4026 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4028 * Changes to command line processing
4030 The new `--args' feature can be used to specify command-line arguments
4031 for the inferior from gdb's command line.
4033 * Changes to key bindings
4035 There is a new `operate-and-get-next' function bound to `C-o'.
4037 *** Changes in GDB 5.1.1
4039 Fix compile problem on DJGPP.
4041 Fix a problem with floating-point registers on the i386 being
4044 Fix to stop GDB crashing on .debug_str debug info.
4046 Numerous documentation fixes.
4048 Numerous testsuite fixes.
4050 *** Changes in GDB 5.1:
4052 * New native configurations
4054 Alpha FreeBSD alpha*-*-freebsd*
4055 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4056 MIPS GNU/Linux mips*-*-linux*
4057 MIPS SGI Irix 6.x mips*-sgi-irix6*
4058 ia64 AIX ia64-*-aix*
4059 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4063 Motorola 68HC11 and 68HC12 m68hc11-elf
4065 UltraSparc running GNU/Linux sparc64-*-linux*
4067 * OBSOLETE configurations and files
4069 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4070 Harris/CXUX m88k m88*-harris-cxux*
4071 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4072 ns32k-utek-sysv* ns32k-utek-*
4073 TI TMS320C80 tic80-*-*
4075 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4076 PowerPC Solaris powerpcle-*-solaris*
4077 PowerPC Windows NT powerpcle-*-cygwin32
4078 PowerPC Netware powerpc-*-netware*
4079 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4080 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4081 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4082 Apple Macintosh (MPW) host N/A
4084 stuff.c (Program to stuff files into a specially prepared space in kdb)
4085 kdb-start.c (Main loop for the standalone kernel debugger)
4087 Configurations that have been declared obsolete in this release have
4088 been commented out. Unless there is activity to revive these
4089 configurations, the next release of GDB will have their sources
4090 permanently REMOVED.
4092 * REMOVED configurations and files
4094 Altos 3068 m68*-altos-*
4095 Convex c1-*-*, c2-*-*
4097 ARM RISCix arm-*-* (as host)
4101 * GDB has been converted to ISO C.
4103 GDB's source code has been converted to ISO C. In particular, the
4104 sources are fully protoized, and rely on standard headers being
4109 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4111 * The MI enabled by default.
4113 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4114 revised and enabled by default. Packages which use GDB as a debugging
4115 engine behind a UI or another front end are encouraged to switch to
4116 using the GDB/MI interface, instead of the old annotations interface
4117 which is now deprecated.
4119 * Support for debugging Pascal programs.
4121 GDB now includes support for debugging Pascal programs. The following
4122 main features are supported:
4124 - Pascal-specific data types such as sets;
4126 - automatic recognition of Pascal sources based on file-name
4129 - Pascal-style display of data types, variables, and functions;
4131 - a Pascal expression parser.
4133 However, some important features are not yet supported.
4135 - Pascal string operations are not supported at all;
4137 - there are some problems with boolean types;
4139 - Pascal type hexadecimal constants are not supported
4140 because they conflict with the internal variables format;
4142 - support for Pascal objects and classes is not full yet;
4144 - unlike Pascal, GDB is case-sensitive for symbol names.
4146 * Changes in completion.
4148 Commands such as `shell', `run' and `set args', which pass arguments
4149 to inferior programs, now complete on file names, similar to what
4150 users expect at the shell prompt.
4152 Commands which accept locations, such as `disassemble', `print',
4153 `breakpoint', `until', etc. now complete on filenames as well as
4154 program symbols. Thus, if you type "break foob TAB", and the source
4155 files linked into the programs include `foobar.c', that file name will
4156 be one of the candidates for completion. However, file names are not
4157 considered for completion after you typed a colon that delimits a file
4158 name from a name of a function in that file, as in "break foo.c:bar".
4160 `set demangle-style' completes on available demangling styles.
4162 * New platform-independent commands:
4164 It is now possible to define a post-hook for a command as well as a
4165 hook that runs before the command. For more details, see the
4166 documentation of `hookpost' in the GDB manual.
4168 * Changes in GNU/Linux native debugging.
4170 Support for debugging multi-threaded programs has been completely
4171 revised for all platforms except m68k and sparc. You can now debug as
4172 many threads as your system allows you to have.
4174 Attach/detach is supported for multi-threaded programs.
4176 Support for SSE registers was added for x86. This doesn't work for
4177 multi-threaded programs though.
4179 * Changes in MIPS configurations.
4181 Multi-arch support is enabled for all MIPS configurations.
4183 GDB can now be built as native debugger on SGI Irix 6.x systems for
4184 debugging n32 executables. (Debugging 64-bit executables is not yet
4187 * Unified support for hardware watchpoints in all x86 configurations.
4189 Most (if not all) native x86 configurations support hardware-assisted
4190 breakpoints and watchpoints in a unified manner. This support
4191 implements debug register sharing between watchpoints, which allows to
4192 put a virtually infinite number of watchpoints on the same address,
4193 and also supports watching regions up to 16 bytes with several debug
4196 The new maintenance command `maintenance show-debug-regs' toggles
4197 debugging print-outs in functions that insert, remove, and test
4198 watchpoints and hardware breakpoints.
4200 * Changes in the DJGPP native configuration.
4202 New command ``info dos sysinfo'' displays assorted information about
4203 the CPU, OS, memory, and DPMI server.
4205 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4206 display information about segment descriptors stored in GDT, LDT, and
4209 New commands ``info dos pde'' and ``info dos pte'' display entries
4210 from Page Directory and Page Tables (for now works with CWSDPMI only).
4211 New command ``info dos address-pte'' displays the Page Table entry for
4212 a given linear address.
4214 GDB can now pass command lines longer than 126 characters to the
4215 program being debugged (requires an update to the libdbg.a library
4216 which is part of the DJGPP development kit).
4218 DWARF2 debug info is now supported.
4220 It is now possible to `step' and `next' through calls to `longjmp'.
4222 * Changes in documentation.
4224 All GDB documentation was converted to GFDL, the GNU Free
4225 Documentation License.
4227 Tracepoints-related commands are now fully documented in the GDB
4230 TUI, the Text-mode User Interface, is now documented in the manual.
4232 Tracepoints-related commands are now fully documented in the GDB
4235 The "GDB Internals" manual now has an index. It also includes
4236 documentation of `ui_out' functions, GDB coding standards, x86
4237 hardware watchpoints, and memory region attributes.
4239 * GDB's version number moved to ``version.in''
4241 The Makefile variable VERSION has been replaced by the file
4242 ``version.in''. People creating GDB distributions should update the
4243 contents of this file.
4247 GUD support is now a standard part of the EMACS distribution.
4249 *** Changes in GDB 5.0:
4251 * Improved support for debugging FP programs on x86 targets
4253 Unified and much-improved support for debugging floating-point
4254 programs on all x86 targets. In particular, ``info float'' now
4255 displays the FP registers in the same format on all x86 targets, with
4256 greater level of detail.
4258 * Improvements and bugfixes in hardware-assisted watchpoints
4260 It is now possible to watch array elements, struct members, and
4261 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4262 on x86 targets no longer erroneously trigger when the address is
4265 * Improvements in the native DJGPP version of GDB
4267 The distribution now includes all the scripts and auxiliary files
4268 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4269 machines ``out of the box''.
4271 The DJGPP version can now debug programs that use signals. It is
4272 possible to catch signals that happened in the debuggee, deliver
4273 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4274 would kill the program being debugged.) Programs that hook hardware
4275 interrupts (keyboard, timer, etc.) can also be debugged.
4277 It is now possible to debug DJGPP programs that redirect their
4278 standard handles or switch them to raw (as opposed to cooked) mode, or
4279 even close them. The command ``run < foo > bar'' works as expected,
4280 and ``info terminal'' reports useful information about the debuggee's
4281 terminal, including raw/cooked mode, redirection, etc.
4283 The DJGPP version now uses termios functions for console I/O, which
4284 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4287 DOS-style file names with drive letters are now fully supported by
4290 It is now possible to debug DJGPP programs that switch their working
4291 directory. It is also possible to rerun the debuggee any number of
4292 times without restarting GDB; thus, you can use the same setup,
4293 breakpoints, etc. for many debugging sessions.
4295 * New native configurations
4297 ARM GNU/Linux arm*-*-linux*
4298 PowerPC GNU/Linux powerpc-*-linux*
4302 Motorola MCore mcore-*-*
4303 x86 VxWorks i[3456]86-*-vxworks*
4304 PowerPC VxWorks powerpc-*-vxworks*
4305 TI TMS320C80 tic80-*-*
4307 * OBSOLETE configurations
4309 Altos 3068 m68*-altos-*
4310 Convex c1-*-*, c2-*-*
4312 ARM RISCix arm-*-* (as host)
4315 Configurations that have been declared obsolete will be commented out,
4316 but the code will be left in place. If there is no activity to revive
4317 these configurations before the next release of GDB, the sources will
4318 be permanently REMOVED.
4320 * Gould support removed
4322 Support for the Gould PowerNode and NP1 has been removed.
4324 * New features for SVR4
4326 On SVR4 native platforms (such as Solaris), if you attach to a process
4327 without first loading a symbol file, GDB will now attempt to locate and
4328 load symbols from the running process's executable file.
4330 * Many C++ enhancements
4332 C++ support has been greatly improved. Overload resolution now works properly
4333 in almost all cases. RTTI support is on the way.
4335 * Remote targets can connect to a sub-program
4337 A popen(3) style serial-device has been added. This device starts a
4338 sub-process (such as a stand-alone simulator) and then communicates
4339 with that. The sub-program to run is specified using the syntax
4340 ``|<program> <args>'' vis:
4342 (gdb) set remotedebug 1
4343 (gdb) target extended-remote |mn10300-elf-sim program-args
4345 * MIPS 64 remote protocol
4347 A long standing bug in the mips64 remote protocol where by GDB
4348 expected certain 32 bit registers (ex SR) to be transfered as 32
4349 instead of 64 bits has been fixed.
4351 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4352 added to provide backward compatibility with older versions of GDB.
4354 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4356 The command ``set remotebinarydownload'' command has been replaced by
4357 ``set remote X-packet''. Other commands in ``set remote'' family
4358 include ``set remote P-packet''.
4360 * Breakpoint commands accept ranges.
4362 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4363 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4364 ``tracepoint passcount'' also accepts a range of tracepoints.
4366 * ``apropos'' command added.
4368 The ``apropos'' command searches through command names and
4369 documentation strings, printing out matches, making it much easier to
4370 try to find a command that does what you are looking for.
4374 A new machine oriented interface (MI) has been added to GDB. This
4375 interface is designed for debug environments running GDB as a separate
4376 process. This is part of the long term libGDB project. See the
4377 "GDB/MI" chapter of the GDB manual for further information. It can be
4378 enabled by configuring with:
4380 .../configure --enable-gdbmi
4382 *** Changes in GDB-4.18:
4384 * New native configurations
4386 HP-UX 10.20 hppa*-*-hpux10.20
4387 HP-UX 11.x hppa*-*-hpux11.0*
4388 M68K GNU/Linux m68*-*-linux*
4392 Fujitsu FR30 fr30-*-elf*
4393 Intel StrongARM strongarm-*-*
4394 Mitsubishi D30V d30v-*-*
4396 * OBSOLETE configurations
4398 Gould PowerNode, NP1 np1-*-*, pn-*-*
4400 Configurations that have been declared obsolete will be commented out,
4401 but the code will be left in place. If there is no activity to revive
4402 these configurations before the next release of GDB, the sources will
4403 be permanently REMOVED.
4407 As a compatibility experiment, GDB's source files buildsym.h and
4408 buildsym.c have been converted to pure standard C, no longer
4409 containing any K&R compatibility code. We believe that all systems in
4410 use today either come with a standard C compiler, or have a GCC port
4411 available. If this is not true, please report the affected
4412 configuration to bug-gdb@gnu.org immediately. See the README file for
4413 information about getting a standard C compiler if you don't have one
4418 GDB now uses readline 2.2.
4420 * set extension-language
4422 You can now control the mapping between filename extensions and source
4423 languages by using the `set extension-language' command. For instance,
4424 you can ask GDB to treat .c files as C++ by saying
4425 set extension-language .c c++
4426 The command `info extensions' lists all of the recognized extensions
4427 and their associated languages.
4429 * Setting processor type for PowerPC and RS/6000
4431 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4432 you can use the `set processor' command to specify what variant of the
4433 PowerPC family you are debugging. The command
4437 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4438 following PowerPC and RS6000 variants:
4440 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4441 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4443 403GC IBM PowerPC 403GC
4444 505 Motorola PowerPC 505
4445 860 Motorola PowerPC 860 or 850
4446 601 Motorola PowerPC 601
4447 602 Motorola PowerPC 602
4448 603 Motorola/IBM PowerPC 603 or 603e
4449 604 Motorola PowerPC 604 or 604e
4450 750 Motorola/IBM PowerPC 750 or 750
4452 At the moment, this command just tells GDB what to name the
4453 special-purpose processor registers. Since almost all the affected
4454 registers are inaccessible to user-level programs, this command is
4455 only useful for remote debugging in its present form.
4459 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4460 more extensive support for HP-UX. Added features include shared
4461 library support, kernel threads and hardware watchpoints for 11.00,
4462 support for HP's ANSI C and C++ compilers, and a compatibility mode
4463 for xdb and dbx commands.
4467 HP's donation includes the new concept of catchpoints, which is a
4468 generalization of the old catch command. On HP-UX, it is now possible
4469 to catch exec, fork, and vfork, as well as library loading.
4471 This means that the existing catch command has changed; its first
4472 argument now specifies the type of catch to be set up. See the
4473 output of "help catch" for a list of catchpoint types.
4475 * Debugging across forks
4477 On HP-UX, you can choose which process to debug when a fork() happens
4482 HP has donated a curses-based terminal user interface (TUI). To get
4483 it, build with --enable-tui. Although this can be enabled for any
4484 configuration, at present it only works for native HP debugging.
4486 * GDB remote protocol additions
4488 A new protocol packet 'X' that writes binary data is now available.
4489 Default behavior is to try 'X', then drop back to 'M' if the stub
4490 fails to respond. The settable variable `remotebinarydownload'
4491 allows explicit control over the use of 'X'.
4493 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4494 full 64-bit address. The command
4496 set remoteaddresssize 32
4498 can be used to revert to the old behaviour. For existing remote stubs
4499 the change should not be noticed, as the additional address information
4502 In order to assist in debugging stubs, you may use the maintenance
4503 command `packet' to send any text string to the stub. For instance,
4505 maint packet heythere
4507 sends the packet "$heythere#<checksum>". Note that it is very easy to
4508 disrupt a debugging session by sending the wrong packet at the wrong
4511 The compare-sections command allows you to compare section data on the
4512 target to what is in the executable file without uploading or
4513 downloading, by comparing CRC checksums.
4515 * Tracing can collect general expressions
4517 You may now collect general expressions at tracepoints. This requires
4518 further additions to the target-side stub; see tracepoint.c and
4519 doc/agentexpr.texi for further details.
4521 * mask-address variable for Mips
4523 For Mips targets, you may control the zeroing of the upper 32 bits of
4524 a 64-bit address by entering `set mask-address on'. This is mainly
4525 of interest to users of embedded R4xxx and R5xxx processors.
4527 * Higher serial baud rates
4529 GDB's serial code now allows you to specify baud rates 57600, 115200,
4530 230400, and 460800 baud. (Note that your host system may not be able
4531 to achieve all of these rates.)
4535 The i960 configuration now includes an initial implementation of a
4536 builtin simulator, contributed by Jim Wilson.
4539 *** Changes in GDB-4.17:
4541 * New native configurations
4543 Alpha GNU/Linux alpha*-*-linux*
4544 Unixware 2.x i[3456]86-unixware2*
4545 Irix 6.x mips*-sgi-irix6*
4546 PowerPC GNU/Linux powerpc-*-linux*
4547 PowerPC Solaris powerpcle-*-solaris*
4548 Sparc GNU/Linux sparc-*-linux*
4549 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4553 Argonaut Risc Chip (ARC) arc-*-*
4554 Hitachi H8/300S h8300*-*-*
4555 Matsushita MN10200 w/simulator mn10200-*-*
4556 Matsushita MN10300 w/simulator mn10300-*-*
4557 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4558 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4559 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4560 Mitsubishi D10V w/simulator d10v-*-*
4561 Mitsubishi M32R/D w/simulator m32r-*-elf*
4562 Tsqware Sparclet sparclet-*-*
4563 NEC V850 w/simulator v850-*-*
4565 * New debugging protocols
4567 ARM with RDI protocol arm*-*-*
4568 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4569 DDB and LSI variants of PMON protocol mips*-*-*
4570 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4571 PowerPC with SDS protocol powerpc{,le}-*-eabi
4572 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4576 All configurations can now understand and use the DWARF 2 debugging
4577 format. The choice is automatic, if the symbol file contains DWARF 2
4582 GDB now includes basic Java language support. This support is
4583 only useful with Java compilers that produce native machine code.
4585 * solib-absolute-prefix and solib-search-path
4587 For SunOS and SVR4 shared libraries, you may now set the prefix for
4588 loading absolute shared library symbol files, and the search path for
4589 locating non-absolute shared library symbol files.
4591 * Live range splitting
4593 GDB can now effectively debug code for which GCC has performed live
4594 range splitting as part of its optimization. See gdb/doc/LRS for
4595 more details on the expected format of the stabs information.
4599 GDB's support for the GNU Hurd, including thread debugging, has been
4600 updated to work with current versions of the Hurd.
4604 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4605 instruction set. ARM GDB automatically detects when Thumb
4606 instructions are in use, and adjusts disassembly and backtracing
4611 GDB's MIPS target configurations now handle the MIP16 16-bit
4616 GDB now includes support for overlays; if an executable has been
4617 linked such that multiple sections are based at the same address, GDB
4618 will decide which section to use for symbolic info. You can choose to
4619 control the decision manually, using overlay commands, or implement
4620 additional target-side support and use "overlay load-target" to bring
4621 in the overlay mapping. Do "help overlay" for more detail.
4625 The command "info symbol <address>" displays information about
4626 the symbol at the specified address.
4630 The standard remote protocol now includes an extension that allows
4631 asynchronous collection and display of trace data. This requires
4632 extensive support in the target-side debugging stub. Tracing mode
4633 includes a new interaction mode in GDB and new commands: see the
4634 file tracepoint.c for more details.
4638 Configurations for embedded MIPS now include a simulator contributed
4639 by Cygnus Solutions. The simulator supports the instruction sets
4640 of most MIPS variants.
4644 Sparc configurations may now include the ERC32 simulator contributed
4645 by the European Space Agency. The simulator is not built into
4646 Sparc targets by default; configure with --enable-sim to include it.
4650 For target configurations that may include multiple variants of a
4651 basic architecture (such as MIPS and SH), you may now set the
4652 architecture explicitly. "set arch" sets, "info arch" lists
4653 the possible architectures.
4655 *** Changes in GDB-4.16:
4657 * New native configurations
4659 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4660 M68K NetBSD m68k-*-netbsd*
4661 PowerPC AIX 4.x powerpc-*-aix*
4662 PowerPC MacOS powerpc-*-macos*
4663 PowerPC Windows NT powerpcle-*-cygwin32
4664 RS/6000 AIX 4.x rs6000-*-aix4*
4668 ARM with RDP protocol arm-*-*
4669 I960 with MON960 i960-*-coff
4670 MIPS VxWorks mips*-*-vxworks*
4671 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4672 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4674 Matra Sparclet sparclet-*-*
4678 The powerpc-eabi configuration now includes the PSIM simulator,
4679 contributed by Andrew Cagney, with assistance from Mike Meissner.
4680 PSIM is a very elaborate model of the PowerPC, including not only
4681 basic instruction set execution, but also details of execution unit
4682 performance and I/O hardware. See sim/ppc/README for more details.
4686 GDB now works with Solaris 2.5.
4688 * Windows 95/NT native
4690 GDB will now work as a native debugger on Windows 95 and Windows NT.
4691 To build it from source, you must use the "gnu-win32" environment,
4692 which uses a DLL to emulate enough of Unix to run the GNU tools.
4693 Further information, binaries, and sources are available at
4694 ftp.cygnus.com, under pub/gnu-win32.
4696 * dont-repeat command
4698 If a user-defined command includes the command `dont-repeat', then the
4699 command will not be repeated if the user just types return. This is
4700 useful if the command is time-consuming to run, so that accidental
4701 extra keystrokes don't run the same command many times.
4703 * Send break instead of ^C
4705 The standard remote protocol now includes an option to send a break
4706 rather than a ^C to the target in order to interrupt it. By default,
4707 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4709 * Remote protocol timeout
4711 The standard remote protocol includes a new variable `remotetimeout'
4712 that allows you to set the number of seconds before GDB gives up trying
4713 to read from the target. The default value is 2.
4715 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4717 By default GDB will automatically keep track of objects as they are
4718 loaded and unloaded by the dynamic linker. By using the command `set
4719 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4720 when shared library events occur, thus allowing you to set breakpoints
4721 in shared libraries which are explicitly loaded by the inferior.
4723 Note this feature does not work on hpux8. On hpux9 you must link
4724 /usr/lib/end.o into your program. This feature should work
4725 automatically on hpux10.
4727 * Irix 5.x hardware watchpoint support
4729 Irix 5 configurations now support the use of hardware watchpoints.
4731 * Mips protocol "SYN garbage limit"
4733 When debugging a Mips target using the `target mips' protocol, you
4734 may set the number of characters that GDB will ignore by setting
4735 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4736 every character. The default value is 1050.
4738 * Recording and replaying remote debug sessions
4740 If you set `remotelogfile' to the name of a file, gdb will write to it
4741 a recording of a remote debug session. This recording may then be
4742 replayed back to gdb using "gdbreplay". See gdbserver/README for
4743 details. This is useful when you have a problem with GDB while doing
4744 remote debugging; you can make a recording of the session and send it
4745 to someone else, who can then recreate the problem.
4747 * Speedups for remote debugging
4749 GDB includes speedups for downloading and stepping MIPS systems using
4750 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4751 and more efficient S-record downloading.
4753 * Memory use reductions and statistics collection
4755 GDB now uses less memory and reports statistics about memory usage.
4756 Try the `maint print statistics' command, for example.
4758 *** Changes in GDB-4.15:
4760 * Psymtabs for XCOFF
4762 The symbol reader for AIX GDB now uses partial symbol tables. This
4763 can greatly improve startup time, especially for large executables.
4765 * Remote targets use caching
4767 Remote targets now use a data cache to speed up communication with the
4768 remote side. The data cache could lead to incorrect results because
4769 it doesn't know about volatile variables, thus making it impossible to
4770 debug targets which use memory mapped I/O devices. `set remotecache
4771 off' turns the the data cache off.
4773 * Remote targets may have threads
4775 The standard remote protocol now includes support for multiple threads
4776 in the target system, using new protocol commands 'H' and 'T'. See
4777 gdb/remote.c for details.
4781 If GDB is configured with `--enable-netrom', then it will include
4782 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4783 acts as though it is a bank of ROM on the target board, but you can
4784 write into it over the network. GDB's support consists only of
4785 support for fast loading into the emulated ROM; to debug, you must use
4786 another protocol, such as standard remote protocol. The usual
4787 sequence is something like
4789 target nrom <netrom-hostname>
4791 target remote <netrom-hostname>:1235
4795 GDB now includes support for the Apple Macintosh, as a host only. It
4796 may be run as either an MPW tool or as a standalone application, and
4797 it can debug through the serial port. All the usual GDB commands are
4798 available, but to the target command, you must supply "serial" as the
4799 device type instead of "/dev/ttyXX". See mpw-README in the main
4800 directory for more information on how to build. The MPW configuration
4801 scripts */mpw-config.in support only a few targets, and only the
4802 mips-idt-ecoff target has been tested.
4806 GDB configuration now uses autoconf. This is not user-visible,
4807 but does simplify configuration and building.
4811 GDB now supports hpux10.
4813 *** Changes in GDB-4.14:
4815 * New native configurations
4817 x86 FreeBSD i[345]86-*-freebsd
4818 x86 NetBSD i[345]86-*-netbsd
4819 NS32k NetBSD ns32k-*-netbsd
4820 Sparc NetBSD sparc-*-netbsd
4824 A29K VxWorks a29k-*-vxworks
4825 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4826 CPU32 EST-300 emulator m68*-*-est*
4827 PowerPC ELF powerpc-*-elf
4830 * Alpha OSF/1 support for procfs
4832 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4833 possible to attach to running processes. As the mounting of the /proc
4834 filesystem is optional on the Alpha, GDB automatically determines
4835 the availability of /proc during startup. This can lead to problems
4836 if /proc is unmounted after GDB has been started.
4838 * Arguments to user-defined commands
4840 User commands may accept up to 10 arguments separated by whitespace.
4841 Arguments are accessed within the user command via $arg0..$arg9. A
4844 print $arg0 + $arg1 + $arg2
4846 To execute the command use:
4849 Defines the command "adder" which prints the sum of its three arguments.
4850 Note the arguments are text substitutions, so they may reference variables,
4851 use complex expressions, or even perform inferior function calls.
4853 * New `if' and `while' commands
4855 This makes it possible to write more sophisticated user-defined
4856 commands. Both commands take a single argument, which is the
4857 expression to evaluate, and must be followed by the commands to
4858 execute, one per line, if the expression is nonzero, the list being
4859 terminated by the word `end'. The `if' command list may include an
4860 `else' word, which causes the following commands to be executed only
4861 if the expression is zero.
4863 * Fortran source language mode
4865 GDB now includes partial support for Fortran 77. It will recognize
4866 Fortran programs and can evaluate a subset of Fortran expressions, but
4867 variables and functions may not be handled correctly. GDB will work
4868 with G77, but does not yet know much about symbols emitted by other
4871 * Better HPUX support
4873 Most debugging facilities now work on dynamic executables for HPPAs
4874 running hpux9 or later. You can attach to running dynamically linked
4875 processes, but by default the dynamic libraries will be read-only, so
4876 for instance you won't be able to put breakpoints in them. To change
4877 that behavior do the following before running the program:
4883 This will cause the libraries to be mapped private and read-write.
4884 To revert to the normal behavior, do this:
4890 You cannot set breakpoints or examine data in the library until after
4891 the library is loaded if the function/data symbols do not have
4894 GDB can now also read debug symbols produced by the HP C compiler on
4895 HPPAs (sorry, no C++, Fortran or 68k support).
4897 * Target byte order now dynamically selectable
4899 You can choose which byte order to use with a target system, via the
4900 commands "set endian big" and "set endian little", and you can see the
4901 current setting by using "show endian". You can also give the command
4902 "set endian auto", in which case GDB will use the byte order
4903 associated with the executable. Currently, only embedded MIPS
4904 configurations support dynamic selection of target byte order.
4906 * New DOS host serial code
4908 This version uses DPMI interrupts to handle buffered I/O, so you
4909 no longer need to run asynctsr when debugging boards connected to
4912 *** Changes in GDB-4.13:
4914 * New "complete" command
4916 This lists all the possible completions for the rest of the line, if it
4917 were to be given as a command itself. This is intended for use by emacs.
4919 * Trailing space optional in prompt
4921 "set prompt" no longer adds a space for you after the prompt you set. This
4922 allows you to set a prompt which ends in a space or one that does not.
4924 * Breakpoint hit counts
4926 "info break" now displays a count of the number of times the breakpoint
4927 has been hit. This is especially useful in conjunction with "ignore"; you
4928 can ignore a large number of breakpoint hits, look at the breakpoint info
4929 to see how many times the breakpoint was hit, then run again, ignoring one
4930 less than that number, and this will get you quickly to the last hit of
4933 * Ability to stop printing at NULL character
4935 "set print null-stop" will cause GDB to stop printing the characters of
4936 an array when the first NULL is encountered. This is useful when large
4937 arrays actually contain only short strings.
4939 * Shared library breakpoints
4941 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4942 breakpoints in shared libraries before the executable is run.
4944 * Hardware watchpoints
4946 There is a new hardware breakpoint for the watch command for sparclite
4947 targets. See gdb/sparclite/hw_breakpoint.note.
4949 Hardware watchpoints are also now supported under GNU/Linux.
4953 Annotations have been added. These are for use with graphical interfaces,
4954 and are still experimental. Currently only gdba.el uses these.
4956 * Improved Irix 5 support
4958 GDB now works properly with Irix 5.2.
4960 * Improved HPPA support
4962 GDB now works properly with the latest GCC and GAS.
4964 * New native configurations
4966 Sequent PTX4 i[34]86-sequent-ptx4
4967 HPPA running OSF/1 hppa*-*-osf*
4968 Atari TT running SVR4 m68*-*-sysv4*
4969 RS/6000 LynxOS rs6000-*-lynxos*
4973 OS/9000 i[34]86-*-os9k
4974 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4977 * Hitachi SH7000 and E7000-PC ICE support
4979 There is now support for communicating with the Hitachi E7000-PC ICE.
4980 This is available automatically when GDB is configured for the SH.
4984 As usual, a variety of small fixes and improvements, both generic
4985 and configuration-specific. See the ChangeLog for more detail.
4987 *** Changes in GDB-4.12:
4989 * Irix 5 is now supported
4993 GDB-4.12 on the HPPA has a number of changes which make it unable
4994 to debug the output from the currently released versions of GCC and
4995 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4996 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4997 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5000 *** Changes in GDB-4.11:
5002 * User visible changes:
5006 The "set remotedebug" option is now consistent between the mips remote
5007 target, remote targets using the gdb-specific protocol, UDI (AMD's
5008 debug protocol for the 29k) and the 88k bug monitor. It is now an
5009 integer specifying a debug level (normally 0 or 1, but 2 means more
5010 debugging info for the mips target).
5012 * DEC Alpha native support
5014 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5015 debug info, but GDB works fairly well with the DEC compiler and should
5016 work with a future GCC release. See the README file for a few
5017 Alpha-specific notes.
5019 * Preliminary thread implementation
5021 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5023 * LynxOS native and target support for 386
5025 This release has been hosted on LynxOS 2.2, and also can be configured
5026 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5029 * Improvements in C++ mangling/demangling.
5031 This release has much better g++ debugging, specifically in name
5032 mangling/demangling, virtual function calls, print virtual table,
5033 call methods, ...etc.
5035 *** Changes in GDB-4.10:
5037 * User visible changes:
5039 Remote debugging using the GDB-specific (`target remote') protocol now
5040 supports the `load' command. This is only useful if you have some
5041 other way of getting the stub to the target system, and you can put it
5042 somewhere in memory where it won't get clobbered by the download.
5044 Filename completion now works.
5046 When run under emacs mode, the "info line" command now causes the
5047 arrow to point to the line specified. Also, "info line" prints
5048 addresses in symbolic form (as well as hex).
5050 All vxworks based targets now support a user settable option, called
5051 vxworks-timeout. This option represents the number of seconds gdb
5052 should wait for responses to rpc's. You might want to use this if
5053 your vxworks target is, perhaps, a slow software simulator or happens
5054 to be on the far side of a thin network line.
5058 This release contains support for using a DEC alpha as a GDB host for
5059 cross debugging. Native alpha debugging is not supported yet.
5062 *** Changes in GDB-4.9:
5066 This is the first GDB release which is accompanied by a matching testsuite.
5067 The testsuite requires installation of dejagnu, which should be available
5068 via ftp from most sites that carry GNU software.
5072 'Cfront' style demangling has had its name changed to 'ARM' style, to
5073 emphasize that it was written from the specifications in the C++ Annotated
5074 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5075 disclaimers, it still generated too much confusion with users attempting to
5076 use gdb with AT&T cfront.
5080 GDB now uses a standard remote interface to a simulator library.
5081 So far, the library contains simulators for the Zilog Z8001/2, the
5082 Hitachi H8/300, H8/500 and Super-H.
5084 * New targets supported
5086 H8/300 simulator h8300-hitachi-hms or h8300hms
5087 H8/500 simulator h8500-hitachi-hms or h8500hms
5088 SH simulator sh-hitachi-hms or sh
5089 Z8000 simulator z8k-zilog-none or z8ksim
5090 IDT MIPS board over serial line mips-idt-ecoff
5092 Cross-debugging to GO32 targets is supported. It requires a custom
5093 version of the i386-stub.c module which is integrated with the
5094 GO32 memory extender.
5096 * New remote protocols
5098 MIPS remote debugging protocol.
5100 * New source languages supported
5102 This version includes preliminary support for Chill, a Pascal like language
5103 used by telecommunications companies. Chill support is also being integrated
5104 into the GNU compiler, but we don't know when it will be publically available.
5107 *** Changes in GDB-4.8:
5109 * HP Precision Architecture supported
5111 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5112 version of this support was available as a set of patches from the
5113 University of Utah. GDB does not support debugging of programs
5114 compiled with the HP compiler, because HP will not document their file
5115 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5116 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5118 Many problems in the preliminary version have been fixed.
5120 * Faster and better demangling
5122 We have improved template demangling and fixed numerous bugs in the GNU style
5123 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5124 character types (wchar_t) are now supported. Demangling of each symbol is now
5125 only done once, and is cached when the symbol table for a file is read in.
5126 This results in a small increase in memory usage for C programs, a moderate
5127 increase in memory usage for C++ programs, and a fantastic speedup in
5130 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5131 from the specifications in the Annotated Reference Manual, which AT&T's
5132 compiler does not actually implement.
5134 * G++ multiple inheritance compiler problem
5136 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5137 inheritance lattices was reworked to properly discover ambiguities. We
5138 recently found an example which causes this new algorithm to fail in a
5139 very subtle way, producing bad debug information for those classes.
5140 The file 'gcc.patch' (in this directory) can be applied to gcc to
5141 circumvent the problem. A future GCC release will contain a complete
5144 The previous G++ debug info problem (mentioned below for the gdb-4.7
5145 release) is fixed in gcc version 2.3.2.
5147 * Improved configure script
5149 The `configure' script will now attempt to guess your system type if
5150 you don't supply a host system type. The old scheme of supplying a
5151 host system triplet is preferable over using this. All the magic is
5152 done in the new `config.guess' script. Examine it for details.
5154 We have also brought our configure script much more in line with the FSF's
5155 version. It now supports the --with-xxx options. In particular,
5156 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5157 The resulting GDB will not be able to read arbitrary object file formats --
5158 only the format ``expected'' to be used on the configured target system.
5159 We hope to make this the default in a future release.
5161 * Documentation improvements
5163 There's new internal documentation on how to modify GDB, and how to
5164 produce clean changes to the code. We implore people to read it
5165 before submitting changes.
5167 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5168 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5169 `info' files are also provided. To build `info' files from scratch,
5170 you will need the latest `makeinfo' release, which will be available in
5171 a future texinfo-X.Y release.
5173 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5174 We're not sure exactly which versions have this problem, but it has
5175 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5176 or better. If that isn't possible, there is a patch in
5177 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5178 around this problem.
5182 GDB now supports array constants that can be used in expressions typed in by
5183 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5184 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5187 The new directory `gdb/sparclite' contains a program that demonstrates
5188 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5190 * New native hosts supported
5192 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5193 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5195 * New targets supported
5197 AMD 29k family via UDI a29k-amd-udi or udi29k
5199 * New file formats supported
5201 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5202 HPUX core files, and SCO 3.2v2 core files.
5206 Attaching to processes now works again; thanks for the many bug reports.
5208 We have also stomped on a bunch of core dumps caused by
5209 printf_filtered("%s") problems.
5211 We eliminated a copyright problem on the rpc and ptrace header files
5212 for VxWorks, which was discovered at the last minute during the 4.7
5213 release. You should now be able to build a VxWorks GDB.
5215 You can now interrupt gdb while an attached process is running. This
5216 will cause the attached process to stop, and give control back to GDB.
5218 We fixed problems caused by using too many file descriptors
5219 for reading symbols from object files and libraries. This was
5220 especially a problem for programs that used many (~100) shared
5223 The `step' command now only enters a subroutine if there is line number
5224 information for the subroutine. Otherwise it acts like the `next'
5225 command. Previously, `step' would enter subroutines if there was
5226 any debugging information about the routine. This avoids problems
5227 when using `cc -g1' on MIPS machines.
5229 * Internal improvements
5231 GDB's internal interfaces have been improved to make it easier to support
5232 debugging of multiple languages in the future.
5234 GDB now uses a common structure for symbol information internally.
5235 Minimal symbols (derived from linkage symbols in object files), partial
5236 symbols (from a quick scan of debug information), and full symbols
5237 contain a common subset of information, making it easier to write
5238 shared code that handles any of them.
5240 * New command line options
5242 We now accept --silent as an alias for --quiet.
5246 The memory-mapped-malloc library is now licensed under the GNU Library
5247 General Public License.
5249 *** Changes in GDB-4.7:
5251 * Host/native/target split
5253 GDB has had some major internal surgery to untangle the support for
5254 hosts and remote targets. Now, when you configure GDB for a remote
5255 target, it will no longer load in all of the support for debugging
5256 local programs on the host. When fully completed and tested, this will
5257 ensure that arbitrary host/target combinations are possible.
5259 The primary conceptual shift is to separate the non-portable code in
5260 GDB into three categories. Host specific code is required any time GDB
5261 is compiled on that host, regardless of the target. Target specific
5262 code relates to the peculiarities of the target, but can be compiled on
5263 any host. Native specific code is everything else: it can only be
5264 built when the host and target are the same system. Child process
5265 handling and core file support are two common `native' examples.
5267 GDB's use of /proc for controlling Unix child processes is now cleaner.
5268 It has been split out into a single module under the `target_ops' vector,
5269 plus two native-dependent functions for each system that uses /proc.
5271 * New hosts supported
5273 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5274 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5275 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5277 * New targets supported
5279 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5280 68030 and CPU32 m68030-*-*, m68332-*-*
5282 * New native hosts supported
5284 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5285 (386bsd is not well tested yet)
5286 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5288 * New file formats supported
5290 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5291 supports reading of `a.out.adobe' object files, which are an a.out
5292 format extended with minimal information about multiple sections.
5296 `show copying' is the same as the old `info copying'.
5297 `show warranty' is the same as `info warrantee'.
5298 These were renamed for consistency. The old commands continue to work.
5300 `info handle' is a new alias for `info signals'.
5302 You can now define pre-command hooks, which attach arbitrary command
5303 scripts to any command. The commands in the hook will be executed
5304 prior to the user's command. You can also create a hook which will be
5305 executed whenever the program stops. See gdb.texinfo.
5309 We now deal with Cfront style name mangling, and can even extract type
5310 info from mangled symbols. GDB can automatically figure out which
5311 symbol mangling style your C++ compiler uses.
5313 Calling of methods and virtual functions has been improved as well.
5317 The crash that occured when debugging Sun Ansi-C compiled binaries is
5318 fixed. This was due to mishandling of the extra N_SO stabs output
5321 We also finally got Ultrix 4.2 running in house, and fixed core file
5322 support, with help from a dozen people on the net.
5324 John M. Farrell discovered that the reason that single-stepping was so
5325 slow on all of the Mips based platforms (primarily SGI and DEC) was
5326 that we were trying to demangle and lookup a symbol used for internal
5327 purposes on every instruction that was being stepped through. Changing
5328 the name of that symbol so that it couldn't be mistaken for a C++
5329 mangled symbol sped things up a great deal.
5331 Rich Pixley sped up symbol lookups in general by getting much smarter
5332 about when C++ symbol mangling is necessary. This should make symbol
5333 completion (TAB on the command line) much faster. It's not as fast as
5334 we'd like, but it's significantly faster than gdb-4.6.
5338 A new user controllable variable 'call_scratch_address' can
5339 specify the location of a scratch area to be used when GDB
5340 calls a function in the target. This is necessary because the
5341 usual method of putting the scratch area on the stack does not work
5342 in systems that have separate instruction and data spaces.
5344 We integrated changes to support the 29k UDI (Universal Debugger
5345 Interface), but discovered at the last minute that we didn't have all
5346 of the appropriate copyright paperwork. We are working with AMD to
5347 resolve this, and hope to have it available soon.
5351 We have sped up the remote serial line protocol, especially for targets
5352 with lots of registers. It now supports a new `expedited status' ('T')
5353 message which can be used in place of the existing 'S' status message.
5354 This allows the remote stub to send only the registers that GDB
5355 needs to make a quick decision about single-stepping or conditional
5356 breakpoints, eliminating the need to fetch the entire register set for
5357 each instruction being stepped through.
5359 The GDB remote serial protocol now implements a write-through cache for
5360 registers, only re-reading the registers if the target has run.
5362 There is also a new remote serial stub for SPARC processors. You can
5363 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5364 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5365 processor with a serial port.
5369 Configure.in files have become much easier to read and modify. A new
5370 `table driven' format makes it more obvious what configurations are
5371 supported, and what files each one uses.
5375 There is a new opcodes library which will eventually contain all of the
5376 disassembly routines and opcode tables. At present, it only contains
5377 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5378 disassembler (binutils/objdump) to share these routines.
5380 The libiberty library is now copylefted under the GNU Library General
5381 Public License. This allows more liberal use, and was done so libg++
5382 can use it. This makes no difference to GDB, since the Library License
5383 grants all the rights from the General Public License.
5387 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5388 reference to the stabs symbol info used by the debugger. It is (as far
5389 as we know) the only published document on this fascinating topic. We
5390 encourage you to read it, compare it to the stabs information on your
5391 system, and send improvements on the document in general (to
5392 bug-gdb@prep.ai.mit.edu).
5394 And, of course, many bugs have been fixed.
5397 *** Changes in GDB-4.6:
5399 * Better support for C++ function names
5401 GDB now accepts as input the "demangled form" of C++ overloaded function
5402 names and member function names, and can do command completion on such names
5403 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5404 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5405 Make use of command completion, it is your friend.
5407 GDB also now accepts a variety of C++ mangled symbol formats. They are
5408 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5409 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5410 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5411 for the list of formats.
5413 * G++ symbol mangling problem
5415 Recent versions of gcc have a bug in how they emit debugging information for
5416 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5417 directory) can be applied to gcc to fix the problem. Alternatively, if you
5418 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5419 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5420 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5423 * New 'maintenance' command
5425 All of the commands related to hacking GDB internals have been moved out of
5426 the main command set, and now live behind the 'maintenance' command. This
5427 can also be abbreviated as 'mt'. The following changes were made:
5429 dump-me -> maintenance dump-me
5430 info all-breakpoints -> maintenance info breakpoints
5431 printmsyms -> maintenance print msyms
5432 printobjfiles -> maintenance print objfiles
5433 printpsyms -> maintenance print psymbols
5434 printsyms -> maintenance print symbols
5436 The following commands are new:
5438 maintenance demangle Call internal GDB demangler routine to
5439 demangle a C++ link name and prints the result.
5440 maintenance print type Print a type chain for a given symbol
5442 * Change to .gdbinit file processing
5444 We now read the $HOME/.gdbinit file before processing the argv arguments
5445 (e.g. reading symbol files or core files). This allows global parameters to
5446 be set, which will apply during the symbol reading. The ./.gdbinit is still
5447 read after argv processing.
5449 * New hosts supported
5451 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5453 GNU/Linux support i386-unknown-linux or linux
5455 We are also including code to support the HP/PA running BSD and HPUX. This
5456 is almost guaranteed not to work, as we didn't have time to test or build it
5457 for this release. We are including it so that the more adventurous (or
5458 masochistic) of you can play with it. We also had major problems with the
5459 fact that the compiler that we got from HP doesn't support the -g option.
5462 * New targets supported
5464 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5466 * More smarts about finding #include files
5468 GDB now remembers the compilation directory for all include files, and for
5469 all files from which C is generated (like yacc and lex sources). This
5470 greatly improves GDB's ability to find yacc/lex sources, and include files,
5471 especially if you are debugging your program from a directory different from
5472 the one that contains your sources.
5474 We also fixed a bug which caused difficulty with listing and setting
5475 breakpoints in include files which contain C code. (In the past, you had to
5476 try twice in order to list an include file that you hadn't looked at before.)
5478 * Interesting infernals change
5480 GDB now deals with arbitrary numbers of sections, where the symbols for each
5481 section must be relocated relative to that section's landing place in the
5482 target's address space. This work was needed to support ELF with embedded
5483 stabs used by Solaris-2.0.
5485 * Bug fixes (of course!)
5487 There have been loads of fixes for the following things:
5488 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5489 i960, stabs, DOS(GO32), procfs, etc...
5491 See the ChangeLog for details.
5493 *** Changes in GDB-4.5:
5495 * New machines supported (host and target)
5497 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5499 SGI Irix-4.x mips-sgi-irix4 or iris4
5501 * New malloc package
5503 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5504 Mmalloc is capable of handling mutiple heaps of memory. It is also
5505 capable of saving a heap to a file, and then mapping it back in later.
5506 This can be used to greatly speedup the startup of GDB by using a
5507 pre-parsed symbol table which lives in a mmalloc managed heap. For
5508 more details, please read mmalloc/mmalloc.texi.
5512 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5513 'help info proc' for details.
5515 * MIPS ecoff symbol table format
5517 The code that reads MIPS symbol table format is now supported on all hosts.
5518 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5521 * File name changes for MS-DOS
5523 Many files in the config directories have been renamed to make it easier to
5524 support GDB on MS-DOSe systems (which have very restrictive file name
5525 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5526 environment) is close to working but has some remaining problems. Note
5527 that debugging of DOS programs is not supported, due to limitations
5528 in the ``operating system'', but it can be used to host cross-debugging.
5530 * Cross byte order fixes
5532 Many fixes have been made to support cross debugging of Sparc and MIPS
5533 targets from hosts whose byte order differs.
5535 * New -mapped and -readnow options
5537 If memory-mapped files are available on your system through the 'mmap'
5538 system call, you can use the -mapped option on the `file' or
5539 `symbol-file' commands to cause GDB to write the symbols from your
5540 program into a reusable file. If the program you are debugging is
5541 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5542 Future GDB debugging sessions will notice the presence of this file,
5543 and will quickly map in symbol information from it, rather than reading
5544 the symbol table from the executable program. Using the '-mapped'
5545 option in a GDB `file' or `symbol-file' command has the same effect as
5546 starting GDB with the '-mapped' command-line option.
5548 You can cause GDB to read the entire symbol table immediately by using
5549 the '-readnow' option with any of the commands that load symbol table
5550 information (or on the GDB command line). This makes the command
5551 slower, but makes future operations faster.
5553 The -mapped and -readnow options are typically combined in order to
5554 build a `fred.syms' file that contains complete symbol information.
5555 A simple GDB invocation to do nothing but build a `.syms' file for future
5558 gdb -batch -nx -mapped -readnow programname
5560 The `.syms' file is specific to the host machine on which GDB is run.
5561 It holds an exact image of GDB's internal symbol table. It cannot be
5562 shared across multiple host platforms.
5564 * longjmp() handling
5566 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5567 siglongjmp() without losing control. This feature has not yet been ported to
5568 all systems. It currently works on many 386 platforms, all MIPS-based
5569 platforms (SGI, DECstation, etc), and Sun3/4.
5573 Preliminary work has been put in to support the new Solaris OS from Sun. At
5574 this time, it can control and debug processes, but it is not capable of
5579 As always, many many bug fixes. The major areas were with g++, and mipsread.
5580 People using the MIPS-based platforms should experience fewer mysterious
5581 crashes and trashed symbol tables.
5583 *** Changes in GDB-4.4:
5585 * New machines supported (host and target)
5587 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5589 BSD Reno on Vax vax-dec-bsd
5590 Ultrix on Vax vax-dec-ultrix
5592 * New machines supported (target)
5594 AMD 29000 embedded, using EBMON a29k-none-none
5598 GDB continues to improve its handling of C++. `References' work better.
5599 The demangler has also been improved, and now deals with symbols mangled as
5600 per the Annotated C++ Reference Guide.
5602 GDB also now handles `stabs' symbol information embedded in MIPS
5603 `ecoff' symbol tables. Since the ecoff format was not easily
5604 extensible to handle new languages such as C++, this appeared to be a
5605 good way to put C++ debugging info into MIPS binaries. This option
5606 will be supported in the GNU C compiler, version 2, when it is
5609 * New features for SVR4
5611 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5612 shared libraries. Debugging dynamically linked programs should present
5613 only minor differences from debugging statically linked programs.
5615 The `info proc' command will print out information about any process
5616 on an SVR4 system (including the one you are debugging). At the moment,
5617 it prints the address mappings of the process.
5619 If you bring up GDB on another SVR4 system, please send mail to
5620 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5622 * Better dynamic linking support in SunOS
5624 Reading symbols from shared libraries which contain debugging symbols
5625 now works properly. However, there remain issues such as automatic
5626 skipping of `transfer vector' code during function calls, which
5627 make it harder to debug code in a shared library, than to debug the
5628 same code linked statically.
5632 GDB is now using the latest `getopt' routines from the FSF. This
5633 version accepts the -- prefix for options with long names. GDB will
5634 continue to accept the old forms (-option and +option) as well.
5635 Various single letter abbreviations for options have been explicity
5636 added to the option table so that they won't get overshadowed in the
5637 future by other options that begin with the same letter.
5641 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5642 Many assorted bugs have been handled. Many more remain to be handled.
5643 See the various ChangeLog files (primarily in gdb and bfd) for details.
5646 *** Changes in GDB-4.3:
5648 * New machines supported (host and target)
5650 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5651 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5652 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5654 * Almost SCO Unix support
5656 We had hoped to support:
5657 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5658 (except for core file support), but we discovered very late in the release
5659 that it has problems with process groups that render gdb unusable. Sorry
5660 about that. I encourage people to fix it and post the fixes.
5662 * Preliminary ELF and DWARF support
5664 GDB can read ELF object files on System V Release 4, and can handle
5665 debugging records for C, in DWARF format, in ELF files. This support
5666 is preliminary. If you bring up GDB on another SVR4 system, please
5667 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5672 GDB now uses the latest `readline' library. One user-visible change
5673 is that two tabs will list possible command completions, which previously
5674 required typing M-? (meta-question mark, or ESC ?).
5678 The `stepi' bug that many of you noticed has been squashed.
5679 Many bugs in C++ have been handled. Many more remain to be handled.
5680 See the various ChangeLog files (primarily in gdb and bfd) for details.
5682 * State of the MIPS world (in case you wondered):
5684 GDB can understand the symbol tables emitted by the compilers
5685 supplied by most vendors of MIPS-based machines, including DEC. These
5686 symbol tables are in a format that essentially nobody else uses.
5688 Some versions of gcc come with an assembler post-processor called
5689 mips-tfile. This program is required if you want to do source-level
5690 debugging of gcc-compiled programs. I believe FSF does not ship
5691 mips-tfile with gcc version 1, but it will eventually come with gcc
5694 Debugging of g++ output remains a problem. g++ version 1.xx does not
5695 really support it at all. (If you're lucky, you should be able to get
5696 line numbers and stack traces to work, but no parameters or local
5697 variables.) With some work it should be possible to improve the
5700 When gcc version 2 is released, you will have somewhat better luck.
5701 However, even then you will get confusing results for inheritance and
5704 We will eventually provide full debugging of g++ output on
5705 DECstations. This will probably involve some kind of stabs-in-ecoff
5706 encapulation, but the details have not been worked out yet.
5709 *** Changes in GDB-4.2:
5711 * Improved configuration
5713 Only one copy of `configure' exists now, and it is not self-modifying.
5714 Porting BFD is simpler.
5718 The `step' and `next' commands now only stop at the first instruction
5719 of a source line. This prevents the multiple stops that used to occur
5720 in switch statements, for-loops, etc. `Step' continues to stop if a
5721 function that has debugging information is called within the line.
5725 Lots of small bugs fixed. More remain.
5727 * New host supported (not target)
5729 Intel 386 PC clone running Mach i386-none-mach
5732 *** Changes in GDB-4.1:
5734 * Multiple source language support
5736 GDB now has internal scaffolding to handle several source languages.
5737 It determines the type of each source file from its filename extension,
5738 and will switch expression parsing and number formatting to match the
5739 language of the function in the currently selected stack frame.
5740 You can also specifically set the language to be used, with
5741 `set language c' or `set language modula-2'.
5745 GDB now has preliminary support for the GNU Modula-2 compiler,
5746 currently under development at the State University of New York at
5747 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5748 continue through the fall of 1991 and into 1992.
5750 Other Modula-2 compilers are currently not supported, and attempting to
5751 debug programs compiled with them will likely result in an error as the
5752 symbol table is read. Feel free to work on it, though!
5754 There are hooks in GDB for strict type checking and range checking,
5755 in the `Modula-2 philosophy', but they do not currently work.
5759 GDB can now write to executable and core files (e.g. patch
5760 a variable's value). You must turn this switch on, specify
5761 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5762 by assigning a new value to a variable. Modifications take
5765 * Automatic SunOS shared library reading
5767 When you run your program, GDB automatically determines where its
5768 shared libraries (if any) have been loaded, and reads their symbols.
5769 The `share' command is no longer needed. This also works when
5770 examining core files.
5774 You can specify the number of lines that the `list' command shows.
5777 * New machines supported (host and target)
5779 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5780 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5781 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5783 * New hosts supported (not targets)
5785 IBM RT/PC: romp-ibm-aix or rtpc
5787 * New targets supported (not hosts)
5789 AMD 29000 embedded with COFF a29k-none-coff
5790 AMD 29000 embedded with a.out a29k-none-aout
5791 Ultracomputer remote kernel debug a29k-nyu-kern
5793 * New remote interfaces
5799 *** Changes in GDB-4.0:
5803 Wide output is wrapped at good places to make the output more readable.
5805 Gdb now supports cross-debugging from a host machine of one type to a
5806 target machine of another type. Communication with the target system
5807 is over serial lines. The ``target'' command handles connecting to the
5808 remote system; the ``load'' command will download a program into the
5809 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5810 also supports debugging of realtime processes running under VxWorks,
5811 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5812 stub on the target system.
5814 New CPUs supported include the AMD 29000 and Intel 960.
5816 GDB now reads object files and symbol tables via a ``binary file''
5817 library, which allows a single copy of GDB to debug programs of multiple
5818 object file types such as a.out and coff.
5820 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5821 refcard.dvi and refcard.ps are available to format it).
5824 * Control-Variable user interface simplified
5826 All variables that control the operation of the debugger can be set
5827 by the ``set'' command, and displayed by the ``show'' command.
5829 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5830 ``Show prompt'' produces the response:
5831 Gdb's prompt is new-gdb=>.
5833 What follows are the NEW set commands. The command ``help set'' will
5834 print a complete list of old and new set commands. ``help set FOO''
5835 will give a longer description of the variable FOO. ``show'' will show
5836 all of the variable descriptions and their current settings.
5838 confirm on/off: Enables warning questions for operations that are
5839 hard to recover from, e.g. rerunning the program while
5840 it is already running. Default is ON.
5842 editing on/off: Enables EMACS style command line editing
5843 of input. Previous lines can be recalled with
5844 control-P, the current line can be edited with control-B,
5845 you can search for commands with control-R, etc.
5848 history filename NAME: NAME is where the gdb command history
5849 will be stored. The default is .gdb_history,
5850 or the value of the environment variable
5853 history size N: The size, in commands, of the command history. The
5854 default is 256, or the value of the environment variable
5857 history save on/off: If this value is set to ON, the history file will
5858 be saved after exiting gdb. If set to OFF, the
5859 file will not be saved. The default is OFF.
5861 history expansion on/off: If this value is set to ON, then csh-like
5862 history expansion will be performed on
5863 command line input. The default is OFF.
5865 radix N: Sets the default radix for input and output. It can be set
5866 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5867 in the current radix, so "set radix 10" is always a no-op.
5869 height N: This integer value is the number of lines on a page. Default
5870 is 24, the current `stty rows'' setting, or the ``li#''
5871 setting from the termcap entry matching the environment
5874 width N: This integer value is the number of characters on a line.
5875 Default is 80, the current `stty cols'' setting, or the ``co#''
5876 setting from the termcap entry matching the environment
5879 Note: ``set screensize'' is obsolete. Use ``set height'' and
5880 ``set width'' instead.
5882 print address on/off: Print memory addresses in various command displays,
5883 such as stack traces and structure values. Gdb looks
5884 more ``symbolic'' if you turn this off; it looks more
5885 ``machine level'' with it on. Default is ON.
5887 print array on/off: Prettyprint arrays. New convenient format! Default
5890 print demangle on/off: Print C++ symbols in "source" form if on,
5893 print asm-demangle on/off: Same, for assembler level printouts
5896 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5899 * Support for Epoch Environment.
5901 The epoch environment is a version of Emacs v18 with windowing. One
5902 new command, ``inspect'', is identical to ``print'', except that if you
5903 are running in the epoch environment, the value is printed in its own
5907 * Support for Shared Libraries
5909 GDB can now debug programs and core files that use SunOS shared libraries.
5910 Symbols from a shared library cannot be referenced
5911 before the shared library has been linked with the program (this
5912 happens after you type ``run'' and before the function main() is entered).
5913 At any time after this linking (including when examining core files
5914 from dynamically linked programs), gdb reads the symbols from each
5915 shared library when you type the ``sharedlibrary'' command.
5916 It can be abbreviated ``share''.
5918 sharedlibrary REGEXP: Load shared object library symbols for files
5919 matching a unix regular expression. No argument
5920 indicates to load symbols for all shared libraries.
5922 info sharedlibrary: Status of loaded shared libraries.
5927 A watchpoint stops execution of a program whenever the value of an
5928 expression changes. Checking for this slows down execution
5929 tremendously whenever you are in the scope of the expression, but is
5930 quite useful for catching tough ``bit-spreader'' or pointer misuse
5931 problems. Some machines such as the 386 have hardware for doing this
5932 more quickly, and future versions of gdb will use this hardware.
5934 watch EXP: Set a watchpoint (breakpoint) for an expression.
5936 info watchpoints: Information about your watchpoints.
5938 delete N: Deletes watchpoint number N (same as breakpoints).
5939 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5940 enable N: Re-enables watchpoint number N (same as breakpoints).
5943 * C++ multiple inheritance
5945 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5948 * C++ exception handling
5950 Gdb now supports limited C++ exception handling. Besides the existing
5951 ability to breakpoint on an exception handler, gdb can breakpoint on
5952 the raising of an exception (before the stack is peeled back to the
5955 catch FOO: If there is a FOO exception handler in the dynamic scope,
5956 set a breakpoint to catch exceptions which may be raised there.
5957 Multiple exceptions (``catch foo bar baz'') may be caught.
5959 info catch: Lists all exceptions which may be caught in the
5960 current stack frame.
5963 * Minor command changes
5965 The command ``call func (arg, arg, ...)'' now acts like the print
5966 command, except it does not print or save a value if the function's result
5967 is void. This is similar to dbx usage.
5969 The ``up'' and ``down'' commands now always print the frame they end up
5970 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5971 frames without printing.
5973 * New directory command
5975 'dir' now adds directories to the FRONT of the source search path.
5976 The path starts off empty. Source files that contain debug information
5977 about the directory in which they were compiled can be found even
5978 with an empty path; Sun CC and GCC include this information. If GDB can't
5979 find your source file in the current directory, type "dir .".
5981 * Configuring GDB for compilation
5983 For normal use, type ``./configure host''. See README or gdb.texinfo
5986 GDB now handles cross debugging. If you are remotely debugging between
5987 two different machines, type ``./configure host -target=targ''.
5988 Host is the machine where GDB will run; targ is the machine
5989 where the program that you are debugging will run.