1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.9
6 * The "info source" command now displays the producer string if it was
7 present in the debug info. This typically includes the compiler version
8 and may include things like its command line arguments.
12 ** gdb.Objfile objects have a new attribute "username",
13 which is the name of the objfile as specified by the user,
14 without, for example, resolving symlinks.
18 maint print symbol-cache
19 Print the contents of the symbol cache.
21 maint print symbol-cache-statistics
22 Print statistics of symbol cache usage.
24 maint flush-symbol-cache
25 Flush the contents of the symbol cache.
29 Start branch trace recording using Branch Trace Store (BTS) format.
35 Set the maximum number of candidates to be considered during
36 completion. The default value is 200. This limit allows GDB
37 to avoid generating large completion lists, the computation of
38 which can cause the debugger to become temporarily unresponsive.
40 maint set symbol-cache-size
41 maint show symbol-cache-size
42 Control the size of the symbol cache.
44 set|show record btrace bts buffer-size
45 Set and show the size of the ring buffer used for branch tracing in
47 The obtained size may differ from the requested size. Use "info
48 record" to see the obtained buffer size.
50 * The command 'thread apply all' can now support new option '-ascending'
51 to call its specified command for all threads in ascending order.
53 * Python/Guile scripting
55 ** GDB now supports auto-loading of Python/Guile scripts contained in the
56 special section named `.debug_gdb_scripts'.
60 qXfer:btrace-conf:read
61 Return the branch trace configuration for the current thread.
64 Set the requested ring buffer size for branch tracing in BTS format.
66 * The info record command now shows the recording format and the
67 branch tracing configuration for the current thread when using
68 the btrace record target.
69 For the BTS format, it shows the ring buffer size.
71 * GDB now has support for DTrace USDT (Userland Static Defined
72 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
74 *** Changes in GDB 7.9
76 * GDB now supports hardware watchpoints on x86 GNU Hurd.
80 ** You can now access frame registers from Python scripts.
81 ** New attribute 'producer' for gdb.Symtab objects.
82 ** gdb.Objfile objects have a new attribute "progspace",
83 which is the gdb.Progspace object of the containing program space.
84 ** gdb.Objfile objects have a new attribute "owner".
85 ** gdb.Objfile objects have a new attribute "build_id",
86 which is the build ID generated when the file was built.
87 ** gdb.Objfile objects have a new method "add_separate_debug_file".
88 ** A new event "gdb.clear_objfiles" has been added, triggered when
89 selecting a new file to debug.
90 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
91 ** New function gdb.lookup_objfile.
93 New events which are triggered when GDB modifies the state of the
96 ** gdb.events.inferior_call_pre: Function call is about to be made.
97 ** gdb.events.inferior_call_post: Function call has just been made.
98 ** gdb.events.memory_changed: A memory location has been altered.
99 ** gdb.events.register_changed: A register has been altered.
101 * New Python-based convenience functions:
103 ** $_caller_is(name [, number_of_frames])
104 ** $_caller_matches(regexp [, number_of_frames])
105 ** $_any_caller_is(name [, number_of_frames])
106 ** $_any_caller_matches(regexp [, number_of_frames])
108 * GDB now supports the compilation and injection of source code into
109 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
110 to compile the source code to object code, and if successful, inject
111 and execute that code within the current context of the inferior.
112 Currently the C language is supported. The commands used to
113 interface with this new feature are:
115 compile code [-raw|-r] [--] [source code]
116 compile file [-raw|-r] filename
120 demangle [-l language] [--] name
121 Demangle "name" in the specified language, or the current language
122 if elided. This command is renamed from the "maint demangle" command.
123 The latter is kept as a no-op to avoid "maint demangle" being interpreted
124 as "maint demangler-warning".
126 queue-signal signal-name-or-number
127 Queue a signal to be delivered to the thread when it is resumed.
129 add-auto-load-scripts-directory directory
130 Add entries to the list of directories from which to load auto-loaded
133 maint print user-registers
134 List all currently available "user" registers.
136 compile code [-r|-raw] [--] [source code]
137 Compile, inject, and execute in the inferior the executable object
138 code produced by compiling the provided source code.
140 compile file [-r|-raw] filename
141 Compile and inject into the inferior the executable object code
142 produced by compiling the source code stored in the filename
145 * On resume, GDB now always passes the signal the program had stopped
146 for to the thread the signal was sent to, even if the user changed
147 threads before resuming. Previously GDB would often (but not
148 always) deliver the signal to the thread that happens to be current
151 * Conversely, the "signal" command now consistently delivers the
152 requested signal to the current thread. GDB now asks for
153 confirmation if the program had stopped for a signal and the user
154 switched threads meanwhile.
156 * "breakpoint always-inserted" modes "off" and "auto" merged.
158 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
159 won't remove breakpoints from the target until all threads stop,
160 even in non-stop mode. The "auto" mode has been removed, and "off"
161 is now the default mode.
165 set debug symbol-lookup
166 show debug symbol-lookup
167 Control display of debugging info regarding symbol lookup.
171 ** The -list-thread-groups command outputs an exit-code field for
172 inferiors that have exited.
176 MIPS SDE mips*-sde*-elf*
180 Support for these obsolete configurations has been removed.
182 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
183 SGI Irix-5.x mips-*-irix5*
184 SGI Irix-6.x mips-*-irix6*
185 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
186 VAX running Ultrix vax-*-ultrix*
188 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
189 and "assf"), have been removed. Use the "sharedlibrary" command, or
190 its alias "share", instead.
192 *** Changes in GDB 7.8
194 * New command line options
197 This is an alias for the --data-directory option.
199 * GDB supports printing and modifying of variable length automatic arrays
200 as specified in ISO C99.
202 * The ARM simulator now supports instruction level tracing
203 with or without disassembly.
207 GDB now has support for scripting using Guile. Whether this is
208 available is determined at configure time.
209 Guile version 2.0 or greater is required.
210 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
212 * New commands (for set/show, see "New options" below)
216 Invoke CODE by passing it to the Guile interpreter.
220 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
222 info auto-load guile-scripts [regexp]
223 Print the list of automatically loaded Guile scripts.
225 * The source command is now capable of sourcing Guile scripts.
226 This feature is dependent on the debugger being built with Guile support.
230 set print symbol-loading (off|brief|full)
231 show print symbol-loading
232 Control whether to print informational messages when loading symbol
233 information for a file. The default is "full", but when debugging
234 programs with large numbers of shared libraries the amount of output
237 set guile print-stack (none|message|full)
238 show guile print-stack
239 Show a stack trace when an error is encountered in a Guile script.
241 set auto-load guile-scripts (on|off)
242 show auto-load guile-scripts
243 Control auto-loading of Guile script files.
245 maint ada set ignore-descriptive-types (on|off)
246 maint ada show ignore-descriptive-types
247 Control whether the debugger should ignore descriptive types in Ada
248 programs. The default is not to ignore the descriptive types. See
249 the user manual for more details on descriptive types and the intended
250 usage of this option.
252 set auto-connect-native-target
254 Control whether GDB is allowed to automatically connect to the
255 native target for the run, attach, etc. commands when not connected
256 to any target yet. See also "target native" below.
258 set record btrace replay-memory-access (read-only|read-write)
259 show record btrace replay-memory-access
260 Control what memory accesses are allowed during replay.
262 maint set target-async (on|off)
263 maint show target-async
264 This controls whether GDB targets operate in synchronous or
265 asynchronous mode. Normally the default is asynchronous, if it is
266 available; but this can be changed to more easily debug problems
267 occurring only in synchronous mode.
269 set mi-async (on|off)
271 Control whether MI asynchronous mode is preferred. This supersedes
272 "set target-async" of previous GDB versions.
274 * "set target-async" is deprecated as a CLI option and is now an alias
275 for "set mi-async" (only puts MI into async mode).
277 * Background execution commands (e.g., "c&", "s&", etc.) are now
278 possible ``out of the box'' if the target supports them. Previously
279 the user would need to explicitly enable the possibility with the
280 "set target-async on" command.
282 * New features in the GDB remote stub, GDBserver
284 ** New option --debug-format=option1[,option2,...] allows one to add
285 additional text to each output. At present only timestamps
286 are supported: --debug-format=timestamps.
287 Timestamps can also be turned on with the
288 "monitor set debug-format timestamps" command from GDB.
290 * The 'record instruction-history' command now starts counting instructions
291 at one. This also affects the instruction ranges reported by the
292 'record function-call-history' command when given the /i modifier.
294 * The command 'record function-call-history' supports a new modifier '/c' to
295 indent the function names based on their call stack depth.
296 The fields for the '/i' and '/l' modifier have been reordered.
297 The source line range is now prefixed with 'at'.
298 The instruction range is now prefixed with 'inst'.
299 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
300 "record instruction-history" and "list" commands.
302 * The ranges given as arguments to the 'record function-call-history' and
303 'record instruction-history' commands are now inclusive.
305 * The btrace record target now supports the 'record goto' command.
306 For locations inside the execution trace, the back trace is computed
307 based on the information stored in the execution trace.
309 * The btrace record target supports limited reverse execution and replay.
310 The target does not record data and therefore does not allow reading
313 * The "catch syscall" command now works on s390*-linux* targets.
315 * The "compare-sections" command is no longer specific to target
316 remote. It now works with all targets.
318 * All native targets are now consistently called "native".
319 Consequently, the "target child", "target GNU", "target djgpp",
320 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
321 commands have been replaced with "target native". The QNX/NTO port
322 leaves the "procfs" target in place and adds a "native" target for
323 consistency with other ports. The impact on users should be minimal
324 as these commands previously either throwed an error, or were
325 no-ops. The target's name is visible in the output of the following
326 commands: "help target", "info target", "info files", "maint print
329 * The "target native" command now connects to the native target. This
330 can be used to launch native programs even when "set
331 auto-connect-native-target" is set to off.
333 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.
335 * Support for Intel(R) AVX-512 registers on GNU/Linux.
336 Support displaying and modifying Intel(R) AVX-512 registers
337 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
341 qXfer:btrace:read's annex
342 The qXfer:btrace:read packet supports a new annex 'delta' to read
343 branch trace incrementally.
347 ** Valid Python operations on gdb.Value objects representing
348 structs/classes invoke the corresponding overloaded operators if
350 ** New `Xmethods' feature in the Python API. Xmethods are
351 additional methods or replacements for existing methods of a C++
352 class. This feature is useful for those cases where a method
353 defined in C++ source code could be inlined or optimized out by
354 the compiler, making it unavailable to GDB.
357 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
359 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
360 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
361 its alias "share", instead.
363 * The commands "set remotebaud" and "show remotebaud" are no longer
364 supported. Use "set serial baud" and "show serial baud" (respectively)
369 ** A new option "-gdb-set mi-async" replaces "-gdb-set
370 target-async". The latter is left as a deprecated alias of the
371 former for backward compatibility. If the target supports it,
372 CLI background execution commands are now always possible by
373 default, independently of whether the frontend stated a
374 preference for asynchronous execution with "-gdb-set mi-async".
375 Previously "-gdb-set target-async off" affected both MI execution
376 commands and CLI execution commands.
378 *** Changes in GDB 7.7
380 * Improved support for process record-replay and reverse debugging on
381 arm*-linux* targets. Support for thumb32 and syscall instruction
382 recording has been added.
384 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
386 * GDB now supports Fission DWP file format version 2.
387 http://gcc.gnu.org/wiki/DebugFission
389 * New convenience function "$_isvoid", to check whether an expression
390 is void. A void expression is an expression where the type of the
391 result is "void". For example, some convenience variables may be
392 "void" when evaluated (e.g., "$_exitcode" before the execution of
393 the program being debugged; or an undefined convenience variable).
394 Another example, when calling a function whose return type is
397 * The "maintenance print objfiles" command now takes an optional regexp.
399 * The "catch syscall" command now works on arm*-linux* targets.
401 * GDB now consistently shows "<not saved>" when printing values of
402 registers the debug info indicates have not been saved in the frame
403 and there's nowhere to retrieve them from
404 (callee-saved/call-clobbered registers):
409 (gdb) info registers rax
412 Before, the former would print "<optimized out>", and the latter
413 "*value not available*".
415 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
420 ** Frame filters and frame decorators have been added.
421 ** Temporary breakpoints are now supported.
422 ** Line tables representation has been added.
423 ** New attribute 'parent_type' for gdb.Field objects.
424 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
425 ** New attribute 'name' for gdb.Type objects.
429 Nios II ELF nios2*-*-elf
430 Nios II GNU/Linux nios2*-*-linux
431 Texas Instruments MSP430 msp430*-*-elf
433 * Removed native configurations
435 Support for these a.out NetBSD and OpenBSD obsolete configurations has
436 been removed. ELF variants of these configurations are kept supported.
438 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
439 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
440 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
441 i[34567]86-*-openbsd3.[0-3]
442 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
443 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
444 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
448 Like "catch throw", but catches a re-thrown exception.
450 Renamed from old "maint check-symtabs".
452 Perform consistency checks on symtabs.
454 Expand symtabs matching an optional regexp.
457 Display the details of GDB configure-time options.
459 maint set|show per-command
460 maint set|show per-command space
461 maint set|show per-command time
462 maint set|show per-command symtab
463 Enable display of per-command gdb resource usage.
465 remove-symbol-file FILENAME
466 remove-symbol-file -a ADDRESS
467 Remove a symbol file added via add-symbol-file. The file to remove
468 can be identified by its filename or by an address that lies within
469 the boundaries of this symbol file in memory.
472 info exceptions REGEXP
473 Display the list of Ada exceptions defined in the program being
474 debugged. If provided, only the exceptions whose names match REGEXP
479 set debug symfile off|on
481 Control display of debugging info regarding reading symbol files and
482 symbol tables within those files
484 set print raw frame-arguments
485 show print raw frame-arguments
486 Set/show whether to print frame arguments in raw mode,
487 disregarding any defined pretty-printers.
489 set remote trace-status-packet
490 show remote trace-status-packet
491 Set/show the use of remote protocol qTStatus packet.
495 Control display of debugging messages related to Nios II targets.
499 Control whether target-assisted range stepping is enabled.
501 set startup-with-shell
502 show startup-with-shell
503 Specifies whether Unix child processes are started via a shell or
508 Use the target memory cache for accesses to the code segment. This
509 improves performance of remote debugging (particularly disassembly).
511 * You can now use a literal value 'unlimited' for options that
512 interpret 0 or -1 as meaning "unlimited". E.g., "set
513 trace-buffer-size unlimited" is now an alias for "set
514 trace-buffer-size -1" and "set height unlimited" is now an alias for
517 * The "set debug symtab-create" debugging option of GDB has been changed to
518 accept a verbosity level. 0 means "off", 1 provides basic debugging
519 output, and values of 2 or greater provides more verbose output.
521 * New command-line options
523 Display the details of GDB configure-time options.
525 * The command 'tsave' can now support new option '-ctf' to save trace
526 buffer in Common Trace Format.
528 * Newly installed $prefix/bin/gcore acts as a shell interface for the
531 * GDB now implements the the C++ 'typeid' operator.
533 * The new convenience variable $_exception holds the exception being
534 thrown or caught at an exception-related catchpoint.
536 * The exception-related catchpoints, like "catch throw", now accept a
537 regular expression which can be used to filter exceptions by type.
539 * The new convenience variable $_exitsignal is automatically set to
540 the terminating signal number when the program being debugged dies
541 due to an uncaught signal.
545 ** All MI commands now accept an optional "--language" option.
546 Support for this feature can be verified by using the "-list-features"
547 command, which should contain "language-option".
549 ** The new command -info-gdb-mi-command allows the user to determine
550 whether a GDB/MI command is supported or not.
552 ** The "^error" result record returned when trying to execute an undefined
553 GDB/MI command now provides a variable named "code" whose content is the
554 "undefined-command" error code. Support for this feature can be verified
555 by using the "-list-features" command, which should contain
556 "undefined-command-error-code".
558 ** The -trace-save MI command can optionally save trace buffer in Common
561 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
563 ** The command -data-list-register-values now accepts an optional
564 "--skip-unavailable" option. When used, only the available registers
567 ** The new command -trace-frame-collected dumps collected variables,
568 computed expressions, tvars, memory and registers in a traceframe.
570 ** The commands -stack-list-locals, -stack-list-arguments and
571 -stack-list-variables now accept an option "--skip-unavailable".
572 When used, only the available locals or arguments are displayed.
574 ** The -exec-run command now accepts an optional "--start" option.
575 When used, the command follows the same semantics as the "start"
576 command, stopping the program's execution at the start of its
577 main subprogram. Support for this feature can be verified using
578 the "-list-features" command, which should contain
579 "exec-run-start-option".
581 ** The new commands -catch-assert and -catch-exceptions insert
582 catchpoints stopping the program when Ada exceptions are raised.
584 ** The new command -info-ada-exceptions provides the equivalent of
585 the new "info exceptions" command.
587 * New system-wide configuration scripts
588 A GDB installation now provides scripts suitable for use as system-wide
589 configuration scripts for the following systems:
593 * GDB now supports target-assigned range stepping with remote targets.
594 This improves the performance of stepping source lines by reducing
595 the number of control packets from/to GDB. See "New remote packets"
598 * GDB now understands the element 'tvar' in the XML traceframe info.
599 It has the id of the collected trace state variables.
601 * On S/390 targets that provide the transactional-execution feature,
602 the program interruption transaction diagnostic block (TDB) is now
603 represented as a number of additional "registers" in GDB.
609 The vCont packet supports a new 'r' action, that tells the remote
610 stub to step through an address range itself, without GDB
611 involvemement at each single-step.
613 qXfer:libraries-svr4:read's annex
614 The previously unused annex of the qXfer:libraries-svr4:read packet
615 is now used to support passing an argument list. The remote stub
616 reports support for this argument list to GDB's qSupported query.
617 The defined arguments are "start" and "prev", used to reduce work
618 necessary for library list updating, resulting in significant
621 * New features in the GDB remote stub, GDBserver
623 ** GDBserver now supports target-assisted range stepping. Currently
624 enabled on x86/x86_64 GNU/Linux targets.
626 ** GDBserver now adds element 'tvar' in the XML in the reply to
627 'qXfer:traceframe-info:read'. It has the id of the collected
628 trace state variables.
630 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
633 * New 'z' formatter for printing and examining memory, this displays the
634 value as hexadecimal zero padded on the left to the size of the type.
636 * GDB can now use Windows x64 unwinding data.
638 * The "set remotebaud" command has been replaced by "set serial baud".
639 Similarly, "show remotebaud" has been replaced by "show serial baud".
640 The "set remotebaud" and "show remotebaud" commands are still available
641 to provide backward compatibility with older versions of GDB.
643 *** Changes in GDB 7.6
645 * Target record has been renamed to record-full.
646 Record/replay is now enabled with the "record full" command.
647 This also affects settings that are associated with full record/replay
648 that have been moved from "set/show record" to "set/show record full":
650 set|show record full insn-number-max
651 set|show record full stop-at-limit
652 set|show record full memory-query
654 * A new record target "record-btrace" has been added. The new target
655 uses hardware support to record the control-flow of a process. It
656 does not support replaying the execution, but it implements the
657 below new commands for investigating the recorded execution log.
658 This new recording method can be enabled using:
662 The "record-btrace" target is only available on Intel Atom processors
663 and requires a Linux kernel 2.6.32 or later.
665 * Two new commands have been added for record/replay to give information
666 about the recorded execution without having to replay the execution.
667 The commands are only supported by "record btrace".
669 record instruction-history prints the execution history at
670 instruction granularity
672 record function-call-history prints the execution history at
675 * New native configurations
677 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
678 FreeBSD/powerpc powerpc*-*-freebsd
679 x86_64/Cygwin x86_64-*-cygwin*
680 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
684 ARM AArch64 aarch64*-*-elf
685 ARM AArch64 GNU/Linux aarch64*-*-linux
686 Lynx 178 PowerPC powerpc-*-lynx*178
687 x86_64/Cygwin x86_64-*-cygwin*
688 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
690 * If the configured location of system.gdbinit file (as given by the
691 --with-system-gdbinit option at configure time) is in the
692 data-directory (as specified by --with-gdb-datadir at configure
693 time) or in one of its subdirectories, then GDB will look for the
694 system-wide init file in the directory specified by the
695 --data-directory command-line option.
697 * New command line options:
699 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
700 other initialization files, unlike -nx which disables all of them.
702 * Removed command line options
704 -epoch This was used by the gdb mode in Epoch, an ancient fork of
707 * The 'ptype' and 'whatis' commands now accept an argument to control
710 * 'info proc' now works on some core files.
714 ** Vectors can be created with gdb.Type.vector.
716 ** Python's atexit.register now works in GDB.
718 ** Types can be pretty-printed via a Python API.
720 ** Python 3 is now supported (in addition to Python 2.4 or later)
722 ** New class gdb.Architecture exposes GDB's internal representation
723 of architecture in the Python API.
725 ** New method Frame.architecture returns the gdb.Architecture object
726 corresponding to the frame's architecture.
728 * New Python-based convenience functions:
730 ** $_memeq(buf1, buf2, length)
731 ** $_streq(str1, str2)
733 ** $_regex(str, regex)
735 * The 'cd' command now defaults to using '~' (the home directory) if not
738 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
739 default for GCC since November 2000.
741 * The command 'forward-search' can now be abbreviated as 'fo'.
743 * The command 'info tracepoints' can now display 'installed on target'
744 or 'not installed on target' for each non-pending location of tracepoint.
746 * New configure options
748 --enable-libmcheck/--disable-libmcheck
749 By default, development versions are built with -lmcheck on hosts
750 that support it, in order to help track memory corruption issues.
751 Release versions, on the other hand, are built without -lmcheck
752 by default. The --enable-libmcheck/--disable-libmcheck configure
753 options allow the user to override that default.
754 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
755 This configure option allows the user to build GDB with
756 libbabeltrace using which GDB can read Common Trace Format data.
758 * New commands (for set/show, see "New options" below)
761 Catch signals. This is similar to "handle", but allows commands and
762 conditions to be attached.
765 List the BFDs known to GDB.
767 python-interactive [command]
769 Start a Python interactive prompt, or evaluate the optional command
770 and print the result of expressions.
773 "py" is a new alias for "python".
775 enable type-printer [name]...
776 disable type-printer [name]...
777 Enable or disable type printers.
781 ** For the Renesas Super-H architecture, the "regs" command has been removed
782 (has been deprecated in GDB 7.5), and "info all-registers" should be used
787 set print type methods (on|off)
788 show print type methods
789 Control whether method declarations are displayed by "ptype".
790 The default is to show them.
792 set print type typedefs (on|off)
793 show print type typedefs
794 Control whether typedef definitions are displayed by "ptype".
795 The default is to show them.
797 set filename-display basename|relative|absolute
798 show filename-display
799 Control the way in which filenames is displayed.
800 The default is "relative", which preserves previous behavior.
802 set trace-buffer-size
803 show trace-buffer-size
804 Request target to change the size of trace buffer.
806 set remote trace-buffer-size-packet auto|on|off
807 show remote trace-buffer-size-packet
808 Control the use of the remote protocol `QTBuffer:size' packet.
812 Control display of debugging messages related to ARM AArch64.
815 set debug coff-pe-read
816 show debug coff-pe-read
817 Control display of debugging messages related to reading of COFF/PE
822 Control display of debugging messages related to Mach-O symbols
825 set debug notification
826 show debug notification
827 Control display of debugging info for async remote notification.
831 ** Command parameter changes are now notified using new async record
832 "=cmd-param-changed".
833 ** Trace frame changes caused by command "tfind" are now notified using
834 new async record "=traceframe-changed".
835 ** The creation, deletion and modification of trace state variables
836 are now notified using new async records "=tsv-created",
837 "=tsv-deleted" and "=tsv-modified".
838 ** The start and stop of process record are now notified using new
839 async record "=record-started" and "=record-stopped".
840 ** Memory changes are now notified using new async record
842 ** The data-disassemble command response will include a "fullname" field
843 containing the absolute file name when source has been requested.
844 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
845 command, to allow pattern filling of memory areas.
846 ** New commands "-catch-load"/"-catch-unload" added for intercepting
847 library load/unload events.
848 ** The response to breakpoint commands and breakpoint async records
849 includes an "installed" field containing a boolean state about each
850 non-pending tracepoint location is whether installed on target or not.
851 ** Output of the "-trace-status" command includes a "trace-file" field
852 containing the name of the trace file being examined. This field is
853 optional, and only present when examining a trace file.
854 ** The "fullname" field is now always present along with the "file" field,
855 even if the file cannot be found by GDB.
857 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
858 You must have the LZMA library available when configuring GDB for this
859 feature to be enabled. For more information, see:
860 http://fedoraproject.org/wiki/Features/MiniDebugInfo
865 Set the size of trace buffer. The remote stub reports support for this
866 packet to gdb's qSupported query.
869 Enable Branch Trace Store (BTS)-based branch tracing for the current
870 thread. The remote stub reports support for this packet to gdb's
874 Disable branch tracing for the current thread. The remote stub reports
875 support for this packet to gdb's qSupported query.
878 Read the traced branches for the current thread. The remote stub
879 reports support for this packet to gdb's qSupported query.
881 *** Changes in GDB 7.5
883 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
884 for more x32 ABI info.
886 * GDB now supports access to MIPS DSP registers on Linux targets.
888 * GDB now supports debugging microMIPS binaries.
890 * The "info os" command on GNU/Linux can now display information on
891 several new classes of objects managed by the operating system:
892 "info os procgroups" lists process groups
893 "info os files" lists file descriptors
894 "info os sockets" lists internet-domain sockets
895 "info os shm" lists shared-memory regions
896 "info os semaphores" lists semaphores
897 "info os msg" lists message queues
898 "info os modules" lists loaded kernel modules
900 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
901 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
902 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
903 options and inspect the probe arguments using the new $_probe_arg family
904 of convenience variables. You can obtain more information about SystemTap
905 in <http://sourceware.org/systemtap/>.
907 * GDB now supports reversible debugging on ARM, it allows you to
908 debug basic ARM and THUMB instructions, and provides
909 record/replay support.
911 * The option "symbol-reloading" has been deleted as it is no longer used.
915 ** GDB commands implemented in Python can now be put in command class
918 ** The "maint set python print-stack on|off" is now deleted.
920 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
921 apply "flag enum"-style pretty-printing to any enum.
923 ** gdb.lookup_symbol can now work when there is no current frame.
925 ** gdb.Symbol now has a 'line' attribute, holding the line number in
926 the source at which the symbol was defined.
928 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
929 method 'value'. The former indicates whether the symbol needs a
930 frame in order to compute its value, and the latter computes the
933 ** A new method 'referenced_value' on gdb.Value objects which can
934 dereference pointer as well as C++ reference values.
936 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
937 which return the global and static blocks (as gdb.Block objects),
938 of the underlying symbol table, respectively.
940 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
941 object associated with a PC value.
943 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
944 of the address range occupied by code for the current source line.
946 * Go language support.
947 GDB now supports debugging programs written in the Go programming
950 * GDBserver now supports stdio connections.
951 E.g. (gdb) target remote | ssh myhost gdbserver - hello
953 * The binary "gdbtui" can no longer be built or installed.
954 Use "gdb -tui" instead.
956 * GDB will now print "flag" enums specially. A flag enum is one where
957 all the enumerator values have no bits in common when pairwise
958 "and"ed. When printing a value whose type is a flag enum, GDB will
959 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
960 (gdb) print (enum E) 3
963 * The filename part of a linespec will now match trailing components
964 of a source file name. For example, "break gcc/expr.c:1000" will
965 now set a breakpoint in build/gcc/expr.c, but not
968 * The "info proc" and "generate-core-file" commands will now also
969 work on remote targets connected to GDBserver on Linux.
971 * The command "info catch" has been removed. It has been disabled
974 * The "catch exception" and "catch assert" commands now accept
975 a condition at the end of the command, much like the "break"
976 command does. For instance:
978 (gdb) catch exception Constraint_Error if Barrier = True
980 Previously, it was possible to add a condition to such catchpoints,
981 but it had to be done as a second step, after the catchpoint had been
982 created, using the "condition" command.
984 * The "info static-tracepoint-marker" command will now also work on
985 native Linux targets with in-process agent.
987 * GDB can now set breakpoints on inlined functions.
989 * The .gdb_index section has been updated to include symbols for
990 inlined functions. GDB will ignore older .gdb_index sections by
991 default, which could cause symbol files to be loaded more slowly
992 until their .gdb_index sections can be recreated. The new command
993 "set use-deprecated-index-sections on" will cause GDB to use any older
994 .gdb_index sections it finds. This will restore performance, but the
995 ability to set breakpoints on inlined functions will be lost in symbol
996 files with older .gdb_index sections.
998 The .gdb_index section has also been updated to record more information
999 about each symbol. This speeds up the "info variables", "info functions"
1000 and "info types" commands when used with programs having the .gdb_index
1001 section, as well as speeding up debugging with shared libraries using
1002 the .gdb_index section.
1004 * Ada support for GDB/MI Variable Objects has been added.
1006 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1011 ** New command -info-os is the MI equivalent of "info os".
1013 ** Output logs ("set logging" and related) now include MI output.
1017 ** "set use-deprecated-index-sections on|off"
1018 "show use-deprecated-index-sections on|off"
1019 Controls the use of deprecated .gdb_index sections.
1021 ** "catch load" and "catch unload" can be used to stop when a shared
1022 library is loaded or unloaded, respectively.
1024 ** "enable count" can be used to auto-disable a breakpoint after
1027 ** "info vtbl" can be used to show the virtual method tables for
1028 C++ and Java objects.
1030 ** "explore" and its sub commands "explore value" and "explore type"
1031 can be used to recursively explore values and types of
1032 expressions. These commands are available only if GDB is
1033 configured with '--with-python'.
1035 ** "info auto-load" shows status of all kinds of auto-loaded files,
1036 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1037 sequences of commands files, "info auto-load python-scripts"
1038 shows status of auto-loading Python script files,
1039 "info auto-load local-gdbinit" shows status of loading init file
1040 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1041 status of inferior specific thread debugging shared library loading.
1043 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1044 and "show auto-load-scripts" commands have been deprecated, use their
1045 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1046 and "show auto-load python-scripts" counterparts instead.
1048 ** "dprintf location,format,args..." creates a dynamic printf, which
1049 is basically a breakpoint that does a printf and immediately
1050 resumes your program's execution, so it is like a printf that you
1051 can insert dynamically at runtime instead of at compiletime.
1053 ** "set print symbol"
1055 Controls whether GDB attempts to display the symbol, if any,
1056 corresponding to addresses it prints. This defaults to "on", but
1057 you can set it to "off" to restore GDB's previous behavior.
1059 * Deprecated commands
1061 ** For the Renesas Super-H architecture, the "regs" command has been
1062 deprecated, and "info all-registers" should be used instead.
1066 Renesas RL78 rl78-*-elf
1067 HP OpenVMS ia64 ia64-hp-openvms*
1069 * GDBserver supports evaluation of breakpoint conditions. When
1070 support is advertised by GDBserver, GDB may be told to send the
1071 breakpoint conditions in bytecode form to GDBserver. GDBserver
1072 will only report the breakpoint trigger to GDB when its condition
1077 set mips compression
1078 show mips compression
1079 Select the compressed ISA encoding used in functions that have no symbol
1080 information available. The encoding can be set to either of:
1083 and is updated automatically from ELF file flags if available.
1085 set breakpoint condition-evaluation
1086 show breakpoint condition-evaluation
1087 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1088 GDBserver ("target"). Default option "auto" chooses the most efficient
1090 This option can improve debugger efficiency depending on the speed of the
1094 Disable auto-loading globally.
1097 Show auto-loading setting of all kinds of auto-loaded files.
1099 set auto-load gdb-scripts on|off
1100 show auto-load gdb-scripts
1101 Control auto-loading of GDB canned sequences of commands files.
1103 set auto-load python-scripts on|off
1104 show auto-load python-scripts
1105 Control auto-loading of Python script files.
1107 set auto-load local-gdbinit on|off
1108 show auto-load local-gdbinit
1109 Control loading of init file (.gdbinit) from current directory.
1111 set auto-load libthread-db on|off
1112 show auto-load libthread-db
1113 Control auto-loading of inferior specific thread debugging shared library.
1115 set auto-load scripts-directory <dir1>[:<dir2>...]
1116 show auto-load scripts-directory
1117 Set a list of directories from which to load auto-loaded scripts.
1118 Automatically loaded Python scripts and GDB scripts are located in one
1119 of the directories listed by this option.
1120 The delimiter (':' above) may differ according to the host platform.
1122 set auto-load safe-path <dir1>[:<dir2>...]
1123 show auto-load safe-path
1124 Set a list of directories from which it is safe to auto-load files.
1125 The delimiter (':' above) may differ according to the host platform.
1127 set debug auto-load on|off
1128 show debug auto-load
1129 Control display of debugging info for auto-loading the files above.
1131 set dprintf-style gdb|call|agent
1133 Control the way in which a dynamic printf is performed; "gdb"
1134 requests a GDB printf command, while "call" causes dprintf to call a
1135 function in the inferior. "agent" requests that the target agent
1136 (such as GDBserver) do the printing.
1138 set dprintf-function <expr>
1139 show dprintf-function
1140 set dprintf-channel <expr>
1141 show dprintf-channel
1142 Set the function and optional first argument to the call when using
1143 the "call" style of dynamic printf.
1145 set disconnected-dprintf on|off
1146 show disconnected-dprintf
1147 Control whether agent-style dynamic printfs continue to be in effect
1148 after GDB disconnects.
1150 * New configure options
1152 --with-auto-load-dir
1153 Configure default value for the 'set auto-load scripts-directory'
1154 setting above. It defaults to '$debugdir:$datadir/auto-load',
1155 $debugdir representing global debugging info directories (available
1156 via 'show debug-file-directory') and $datadir representing GDB's data
1157 directory (available via 'show data-directory').
1159 --with-auto-load-safe-path
1160 Configure default value for the 'set auto-load safe-path' setting
1161 above. It defaults to the --with-auto-load-dir setting.
1163 --without-auto-load-safe-path
1164 Set 'set auto-load safe-path' to '/', effectively disabling this
1167 * New remote packets
1169 z0/z1 conditional breakpoints extension
1171 The z0/z1 breakpoint insertion packets have been extended to carry
1172 a list of conditional expressions over to the remote stub depending on the
1173 condition evaluation mode. The use of this extension can be controlled
1174 via the "set remote conditional-breakpoints-packet" command.
1178 Specify the signals which the remote stub may pass to the debugged
1179 program without GDB involvement.
1181 * New command line options
1183 --init-command=FILE, -ix Like --command, -x but execute it
1184 before loading inferior.
1185 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1186 execute it before loading inferior.
1188 *** Changes in GDB 7.4
1190 * GDB now handles ambiguous linespecs more consistently; the existing
1191 FILE:LINE support has been expanded to other types of linespecs. A
1192 breakpoint will now be set on all matching locations in all
1193 inferiors, and locations will be added or removed according to
1196 * GDB now allows you to skip uninteresting functions and files when
1197 stepping with the "skip function" and "skip file" commands.
1199 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1200 and "show remote hardware-watchpoint-length-limit". These allows to
1201 set or show the maximum length limit (in bytes) of a remote
1202 target hardware watchpoint.
1204 This allows e.g. to use "unlimited" hardware watchpoints with the
1205 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1206 watchpoints are slower than real hardware watchpoints but are
1207 significantly faster than gdb software watchpoints.
1211 ** The register_pretty_printer function in module gdb.printing now takes
1212 an optional `replace' argument. If True, the new printer replaces any
1215 ** The "maint set python print-stack on|off" command has been
1216 deprecated and will be deleted in GDB 7.5.
1217 A new command: "set python print-stack none|full|message" has
1218 replaced it. Additionally, the default for "print-stack" is
1219 now "message", which just prints the error message without
1222 ** A prompt substitution hook (prompt_hook) is now available to the
1225 ** A new Python module, gdb.prompt has been added to the GDB Python
1226 modules library. This module provides functionality for
1227 escape sequences in prompts (used by set/show
1228 extended-prompt). These escape sequences are replaced by their
1229 corresponding value.
1231 ** Python commands and convenience-functions located in
1232 'data-directory'/python/gdb/command and
1233 'data-directory'/python/gdb/function are now automatically loaded
1236 ** Blocks now provide four new attributes. global_block and
1237 static_block will return the global and static blocks
1238 respectively. is_static and is_global are boolean attributes
1239 that indicate if the block is one of those two types.
1241 ** Symbols now provide the "type" attribute, the type of the symbol.
1243 ** The "gdb.breakpoint" function has been deprecated in favor of
1246 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1247 of a function. This class is based on the "finish" command
1248 available in the CLI.
1250 ** Type objects for struct and union types now allow access to
1251 the fields using standard Python dictionary (mapping) methods.
1252 For example, "some_type['myfield']" now works, as does
1253 "some_type.items()".
1255 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1258 ** A new function, "deep_items" has been added to the gdb.types
1259 module in the GDB Python modules library. This function returns
1260 an iterator over the fields of a struct or union type. Unlike
1261 the standard Python "iteritems" method, it will recursively traverse
1262 any anonymous fields.
1266 ** "*stopped" events can report several new "reason"s, such as
1269 ** Breakpoint changes are now notified using new async records, like
1270 "=breakpoint-modified".
1272 ** New command -ada-task-info.
1274 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1275 $sdir specifies the default system locations of shared libraries.
1276 $pdir specifies the directory where the libpthread used by the application
1279 GDB no longer looks in $sdir and $pdir after it has searched the directories
1280 mentioned in libthread-db-search-path. If you want to search those
1281 directories, they must be specified in libthread-db-search-path.
1282 The default value of libthread-db-search-path on GNU/Linux and Solaris
1283 systems is now "$sdir:$pdir".
1285 $pdir is not supported by gdbserver, it is currently ignored.
1286 $sdir is supported by gdbserver.
1288 * New configure option --with-iconv-bin.
1289 When using the internationalization support like the one in the GNU C
1290 library, GDB will invoke the "iconv" program to get a list of supported
1291 character sets. If this program lives in a non-standard location, one can
1292 use this option to specify where to find it.
1294 * When natively debugging programs on PowerPC BookE processors running
1295 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1296 watchpoints, which specify a mask in addition to an address to watch.
1297 The mask specifies that some bits of an address (the bits which are
1298 reset in the mask) should be ignored when matching the address accessed
1299 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1300 section in the user manual for more details.
1302 * The new option --once causes GDBserver to stop listening for connections once
1303 the first connection is made. The listening port used by GDBserver will
1304 become available after that.
1306 * New commands "info macros" and "alias" have been added.
1308 * New function parameters suffix @entry specifies value of function parameter
1309 at the time the function got called. Entry values are available only since
1315 "!" is now an alias of the "shell" command.
1316 Note that no space is needed between "!" and SHELL COMMAND.
1320 watch EXPRESSION mask MASK_VALUE
1321 The watch command now supports the mask argument which allows creation
1322 of masked watchpoints, if the current architecture supports this feature.
1324 info auto-load-scripts [REGEXP]
1325 This command was formerly named "maintenance print section-scripts".
1326 It is now generally useful and is no longer a maintenance-only command.
1328 info macro [-all] [--] MACRO
1329 The info macro command has new options `-all' and `--'. The first for
1330 printing all definitions of a macro. The second for explicitly specifying
1331 the end of arguments and the beginning of the macro name in case the macro
1332 name starts with a hyphen.
1334 collect[/s] EXPRESSIONS
1335 The tracepoint collect command now takes an optional modifier "/s"
1336 that directs it to dereference pointer-to-character types and
1337 collect the bytes of memory up to a zero byte. The behavior is
1338 similar to what you see when you use the regular print command on a
1339 string. An optional integer following the "/s" sets a bound on the
1340 number of bytes that will be collected.
1343 The trace start command now interprets any supplied arguments as a
1344 note to be recorded with the trace run, with an effect similar to
1345 setting the variable trace-notes.
1348 The trace stop command now interprets any arguments as a note to be
1349 mentioned along with the tstatus report that the trace was stopped
1350 with a command. The effect is similar to setting the variable
1353 * Tracepoints can now be enabled and disabled at any time after a trace
1354 experiment has been started using the standard "enable" and "disable"
1355 commands. It is now possible to start a trace experiment with no enabled
1356 tracepoints; GDB will display a warning, but will allow the experiment to
1357 begin, assuming that tracepoints will be enabled as needed while the trace
1360 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1361 locations with 4-byte instructions, when they were previously
1362 limited to locations with instructions of 5 bytes or longer.
1366 set debug dwarf2-read
1367 show debug dwarf2-read
1368 Turns on or off display of debugging messages related to reading
1369 DWARF debug info. The default is off.
1371 set debug symtab-create
1372 show debug symtab-create
1373 Turns on or off display of debugging messages related to symbol table
1374 creation. The default is off.
1377 show extended-prompt
1378 Set the GDB prompt, and allow escape sequences to be inserted to
1379 display miscellaneous information (see 'help set extended-prompt'
1380 for the list of sequences). This prompt (and any information
1381 accessed through the escape sequences) is updated every time the
1382 prompt is displayed.
1384 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1385 show print entry-values
1386 Set printing of frame argument values at function entry. In some cases
1387 GDB can determine the value of function argument which was passed by the
1388 function caller, even if the value was modified inside the called function.
1390 set debug entry-values
1391 show debug entry-values
1392 Control display of debugging info for determining frame argument values at
1393 function entry and virtual tail call frames.
1395 set basenames-may-differ
1396 show basenames-may-differ
1397 Set whether a source file may have multiple base names.
1398 (A "base name" is the name of a file with the directory part removed.
1399 Example: The base name of "/home/user/hello.c" is "hello.c".)
1400 If set, GDB will canonicalize file names (e.g., expand symlinks)
1401 before comparing them. Canonicalization is an expensive operation,
1402 but it allows the same file be known by more than one base name.
1403 If not set (the default), all source files are assumed to have just
1404 one base name, and gdb will do file name comparisons more efficiently.
1410 Set a user name and notes for the current and any future trace runs.
1411 This is useful for long-running and/or disconnected traces, to
1412 inform others (or yourself) as to who is running the trace, supply
1413 contact information, or otherwise explain what is going on.
1415 set trace-stop-notes
1416 show trace-stop-notes
1417 Set a note attached to the trace run, that is displayed when the
1418 trace has been stopped by a tstop command. This is useful for
1419 instance as an explanation, if you are stopping a trace run that was
1420 started by someone else.
1422 * New remote packets
1426 Dynamically enable a tracepoint in a started trace experiment.
1430 Dynamically disable a tracepoint in a started trace experiment.
1434 Set the user and notes of the trace run.
1438 Query the current status of a tracepoint.
1442 Query the minimum length of instruction at which a fast tracepoint may
1445 * Dcache size (number of lines) and line-size are now runtime-configurable
1446 via "set dcache line" and "set dcache line-size" commands.
1450 Texas Instruments TMS320C6x tic6x-*-*
1454 Renesas RL78 rl78-*-elf
1456 *** Changes in GDB 7.3.1
1458 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1460 *** Changes in GDB 7.3
1462 * GDB has a new command: "thread find [REGEXP]".
1463 It finds the thread id whose name, target id, or thread extra info
1464 matches the given regular expression.
1466 * The "catch syscall" command now works on mips*-linux* targets.
1468 * The -data-disassemble MI command now supports modes 2 and 3 for
1469 dumping the instruction opcodes.
1471 * New command line options
1473 -data-directory DIR Specify DIR as the "data-directory".
1474 This is mostly for testing purposes.
1476 * The "maint set python auto-load on|off" command has been renamed to
1477 "set auto-load-scripts on|off".
1479 * GDB has a new command: "set directories".
1480 It is like the "dir" command except that it replaces the
1481 source path list instead of augmenting it.
1483 * GDB now understands thread names.
1485 On GNU/Linux, "info threads" will display the thread name as set by
1486 prctl or pthread_setname_np.
1488 There is also a new command, "thread name", which can be used to
1489 assign a name internally for GDB to display.
1492 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1493 has been integrated into GDB.
1497 ** The function gdb.Write now accepts an optional keyword 'stream'.
1498 This keyword, when provided, will direct the output to either
1499 stdout, stderr, or GDB's logging output.
1501 ** Parameters can now be be sub-classed in Python, and in particular
1502 you may implement the get_set_doc and get_show_doc functions.
1503 This improves how Parameter set/show documentation is processed
1504 and allows for more dynamic content.
1506 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1507 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1508 have an is_valid method.
1510 ** Breakpoints can now be sub-classed in Python, and in particular
1511 you may implement a 'stop' function that is executed each time
1512 the inferior reaches that breakpoint.
1514 ** New function gdb.lookup_global_symbol looks up a global symbol.
1516 ** GDB values in Python are now callable if the value represents a
1517 function. For example, if 'some_value' represents a function that
1518 takes two integer parameters and returns a value, you can call
1519 that function like so:
1521 result = some_value (10,20)
1523 ** Module gdb.types has been added.
1524 It contains a collection of utilities for working with gdb.Types objects:
1525 get_basic_type, has_field, make_enum_dict.
1527 ** Module gdb.printing has been added.
1528 It contains utilities for writing and registering pretty-printers.
1529 New classes: PrettyPrinter, SubPrettyPrinter,
1530 RegexpCollectionPrettyPrinter.
1531 New function: register_pretty_printer.
1533 ** New commands "info pretty-printers", "enable pretty-printer" and
1534 "disable pretty-printer" have been added.
1536 ** gdb.parameter("directories") is now available.
1538 ** New function gdb.newest_frame returns the newest frame in the
1541 ** The gdb.InferiorThread class has a new "name" attribute. This
1542 holds the thread's name.
1544 ** Python Support for Inferior events.
1545 Python scripts can add observers to be notified of events
1546 occurring in the process being debugged.
1547 The following events are currently supported:
1548 - gdb.events.cont Continue event.
1549 - gdb.events.exited Inferior exited event.
1550 - gdb.events.stop Signal received, and Breakpoint hit events.
1554 ** GDB now puts template parameters in scope when debugging in an
1555 instantiation. For example, if you have:
1557 template<int X> int func (void) { return X; }
1559 then if you step into func<5>, "print X" will show "5". This
1560 feature requires proper debuginfo support from the compiler; it
1561 was added to GCC 4.5.
1563 ** The motion commands "next", "finish", "until", and "advance" now
1564 work better when exceptions are thrown. In particular, GDB will
1565 no longer lose control of the inferior; instead, the GDB will
1566 stop the inferior at the point at which the exception is caught.
1567 This functionality requires a change in the exception handling
1568 code that was introduced in GCC 4.5.
1570 * GDB now follows GCC's rules on accessing volatile objects when
1571 reading or writing target state during expression evaluation.
1572 One notable difference to prior behavior is that "print x = 0"
1573 no longer generates a read of x; the value of the assignment is
1574 now always taken directly from the value being assigned.
1576 * GDB now has some support for using labels in the program's source in
1577 linespecs. For instance, you can use "advance label" to continue
1578 execution to a label.
1580 * GDB now has support for reading and writing a new .gdb_index
1581 section. This section holds a fast index of DWARF debugging
1582 information and can be used to greatly speed up GDB startup and
1583 operation. See the documentation for `save gdb-index' for details.
1585 * The "watch" command now accepts an optional "-location" argument.
1586 When used, this causes GDB to watch the memory referred to by the
1587 expression. Such a watchpoint is never deleted due to it going out
1590 * GDB now supports thread debugging of core dumps on GNU/Linux.
1592 GDB now activates thread debugging using the libthread_db library
1593 when debugging GNU/Linux core dumps, similarly to when debugging
1594 live processes. As a result, when debugging a core dump file, GDB
1595 is now able to display pthread_t ids of threads. For example, "info
1596 threads" shows the same output as when debugging the process when it
1597 was live. In earlier releases, you'd see something like this:
1600 * 1 LWP 6780 main () at main.c:10
1602 While now you see this:
1605 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1607 It is also now possible to inspect TLS variables when debugging core
1610 When debugging a core dump generated on a machine other than the one
1611 used to run GDB, you may need to point GDB at the correct
1612 libthread_db library with the "set libthread-db-search-path"
1613 command. See the user manual for more details on this command.
1615 * When natively debugging programs on PowerPC BookE processors running
1616 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1617 which stop execution of the inferior whenever it executes an instruction
1618 at any address within the specified range. See the "PowerPC Embedded"
1619 section in the user manual for more details.
1621 * New features in the GDB remote stub, GDBserver
1623 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1624 and i686 LynxOS (version 5.x).
1626 ** GDBserver is now supported on Blackfin Linux.
1628 * New native configurations
1630 ia64 HP-UX ia64-*-hpux*
1634 Analog Devices, Inc. Blackfin Processor bfin-*
1636 * Ada task switching is now supported on sparc-elf targets when
1637 debugging a program using the Ravenscar Profile. For more information,
1638 see the "Tasking Support when using the Ravenscar Profile" section
1639 in the GDB user manual.
1641 * Guile support was removed.
1643 * New features in the GNU simulator
1645 ** The --map-info flag lists all known core mappings.
1647 ** CFI flashes may be simulated via the "cfi" device.
1649 *** Changes in GDB 7.2
1651 * Shared library support for remote targets by default
1653 When GDB is configured for a generic, non-OS specific target, like
1654 for example, --target=arm-eabi or one of the many *-*-elf targets,
1655 GDB now queries remote stubs for loaded shared libraries using the
1656 `qXfer:libraries:read' packet. Previously, shared library support
1657 was always disabled for such configurations.
1661 ** Argument Dependent Lookup (ADL)
1663 In C++ ADL lookup directs function search to the namespaces of its
1664 arguments even if the namespace has not been imported.
1674 Here the compiler will search for `foo' in the namespace of 'b'
1675 and find A::foo. GDB now supports this. This construct is commonly
1676 used in the Standard Template Library for operators.
1678 ** Improved User Defined Operator Support
1680 In addition to member operators, GDB now supports lookup of operators
1681 defined in a namespace and imported with a `using' directive, operators
1682 defined in the global scope, operators imported implicitly from an
1683 anonymous namespace, and the ADL operators mentioned in the previous
1685 GDB now also supports proper overload resolution for all the previously
1686 mentioned flavors of operators.
1688 ** static const class members
1690 Printing of static const class members that are initialized in the
1691 class definition has been fixed.
1693 * Windows Thread Information Block access.
1695 On Windows targets, GDB now supports displaying the Windows Thread
1696 Information Block (TIB) structure. This structure is visible either
1697 by using the new command `info w32 thread-information-block' or, by
1698 dereferencing the new convenience variable named `$_tlb', a
1699 thread-specific pointer to the TIB. This feature is also supported
1700 when remote debugging using GDBserver.
1702 * Static tracepoints
1704 Static tracepoints are calls in the user program into a tracing
1705 library. One such library is a port of the LTTng kernel tracer to
1706 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1707 When debugging with GDBserver, GDB now supports combining the GDB
1708 tracepoint machinery with such libraries. For example: the user can
1709 use GDB to probe a static tracepoint marker (a call from the user
1710 program into the tracing library) with the new "strace" command (see
1711 "New commands" below). This creates a "static tracepoint" in the
1712 breakpoint list, that can be manipulated with the same feature set
1713 as fast and regular tracepoints. E.g., collect registers, local and
1714 global variables, collect trace state variables, and define
1715 tracepoint conditions. In addition, the user can collect extra
1716 static tracepoint marker specific data, by collecting the new
1717 $_sdata internal variable. When analyzing the trace buffer, you can
1718 inspect $_sdata like any other variable available to GDB. For more
1719 information, see the "Tracepoints" chapter in GDB user manual. New
1720 remote packets have been defined to support static tracepoints, see
1721 the "New remote packets" section below.
1723 * Better reconstruction of tracepoints after disconnected tracing
1725 GDB will attempt to download the original source form of tracepoint
1726 definitions when starting a trace run, and then will upload these
1727 upon reconnection to the target, resulting in a more accurate
1728 reconstruction of the tracepoints that are in use on the target.
1732 You can now exercise direct control over the ways that GDB can
1733 affect your program. For instance, you can disallow the setting of
1734 breakpoints, so that the program can run continuously (assuming
1735 non-stop mode). In addition, the "observer" variable is available
1736 to switch all of the different controls; in observer mode, GDB
1737 cannot affect the target's behavior at all, which is useful for
1738 tasks like diagnosing live systems in the field.
1740 * The new convenience variable $_thread holds the number of the
1743 * New remote packets
1747 Return the address of the Windows Thread Information Block of a given thread.
1751 In response to several of the tracepoint packets, the target may now
1752 also respond with a number of intermediate `qRelocInsn' request
1753 packets before the final result packet, to have GDB handle
1754 relocating an instruction to execute at a different address. This
1755 is particularly useful for stubs that support fast tracepoints. GDB
1756 reports support for this feature in the qSupported packet.
1760 List static tracepoint markers in the target program.
1764 List static tracepoint markers at a given address in the target
1767 qXfer:statictrace:read
1769 Read the static trace data collected (by a `collect $_sdata'
1770 tracepoint action). The remote stub reports support for this packet
1771 to gdb's qSupported query.
1775 Send the current settings of GDB's permission flags.
1779 Send part of the source (textual) form of a tracepoint definition,
1780 which includes location, conditional, and action list.
1782 * The source command now accepts a -s option to force searching for the
1783 script in the source search path even if the script name specifies
1786 * New features in the GDB remote stub, GDBserver
1788 - GDBserver now support tracepoints (including fast tracepoints, and
1789 static tracepoints). The feature is currently supported by the
1790 i386-linux and amd64-linux builds. See the "Tracepoints support
1791 in gdbserver" section in the manual for more information.
1793 GDBserver JIT compiles the tracepoint's conditional agent
1794 expression bytecode into native code whenever possible for low
1795 overhead dynamic tracepoints conditionals. For such tracepoints,
1796 an expression that examines program state is evaluated when the
1797 tracepoint is reached, in order to determine whether to capture
1798 trace data. If the condition is simple and false, processing the
1799 tracepoint finishes very quickly and no data is gathered.
1801 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1802 for static tracepoints support.
1804 - GDBserver now supports x86_64 Windows 64-bit debugging.
1806 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1807 it understands register description.
1809 * The --batch flag now disables pagination and queries.
1811 * X86 general purpose registers
1813 GDB now supports reading/writing byte, word and double-word x86
1814 general purpose registers directly. This means you can use, say,
1815 $ah or $ax to refer, respectively, to the byte register AH and
1816 16-bit word register AX that are actually portions of the 32-bit
1817 register EAX or 64-bit register RAX.
1819 * The `commands' command now accepts a range of breakpoints to modify.
1820 A plain `commands' following a command that creates multiple
1821 breakpoints affects all the breakpoints set by that command. This
1822 applies to breakpoints set by `rbreak', and also applies when a
1823 single `break' command creates multiple breakpoints (e.g.,
1824 breakpoints on overloaded c++ functions).
1826 * The `rbreak' command now accepts a filename specification as part of
1827 its argument, limiting the functions selected by the regex to those
1828 in the specified file.
1830 * Support for remote debugging Windows and SymbianOS shared libraries
1831 from Unix hosts has been improved. Non Windows GDB builds now can
1832 understand target reported file names that follow MS-DOS based file
1833 system semantics, such as file names that include drive letters and
1834 use the backslash character as directory separator. This makes it
1835 possible to transparently use the "set sysroot" and "set
1836 solib-search-path" on Unix hosts to point as host copies of the
1837 target's shared libraries. See the new command "set
1838 target-file-system-kind" described below, and the "Commands to
1839 specify files" section in the user manual for more information.
1843 eval template, expressions...
1844 Convert the values of one or more expressions under the control
1845 of the string template to a command line, and call it.
1847 set target-file-system-kind unix|dos-based|auto
1848 show target-file-system-kind
1849 Set or show the assumed file system kind for target reported file
1852 save breakpoints <filename>
1853 Save all current breakpoint definitions to a file suitable for use
1854 in a later debugging session. To read the saved breakpoint
1855 definitions, use the `source' command.
1857 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1860 info static-tracepoint-markers
1861 Display information about static tracepoint markers in the target.
1863 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1864 Define a static tracepoint by probing a marker at the given
1865 function, line, address, or marker ID.
1869 Enable and disable observer mode.
1871 set may-write-registers on|off
1872 set may-write-memory on|off
1873 set may-insert-breakpoints on|off
1874 set may-insert-tracepoints on|off
1875 set may-insert-fast-tracepoints on|off
1876 set may-interrupt on|off
1877 Set individual permissions for GDB effects on the target. Note that
1878 some of these settings can have undesirable or surprising
1879 consequences, particularly when changed in the middle of a session.
1880 For instance, disabling the writing of memory can prevent
1881 breakpoints from being inserted, cause single-stepping to fail, or
1882 even crash your program, if you disable after breakpoints have been
1883 inserted. However, GDB should not crash.
1885 set record memory-query on|off
1886 show record memory-query
1887 Control whether to stop the inferior if memory changes caused
1888 by an instruction cannot be recorded.
1893 The disassemble command now supports "start,+length" form of two arguments.
1897 ** GDB now provides a new directory location, called the python directory,
1898 where Python scripts written for GDB can be installed. The location
1899 of that directory is <data-directory>/python, where <data-directory>
1900 is the GDB data directory. For more details, see section `Scripting
1901 GDB using Python' in the manual.
1903 ** The GDB Python API now has access to breakpoints, symbols, symbol
1904 tables, program spaces, inferiors, threads and frame's code blocks.
1905 Additionally, GDB Parameters can now be created from the API, and
1906 manipulated via set/show in the CLI.
1908 ** New functions gdb.target_charset, gdb.target_wide_charset,
1909 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1911 ** New exception gdb.GdbError.
1913 ** Pretty-printers are now also looked up in the current program space.
1915 ** Pretty-printers can now be individually enabled and disabled.
1917 ** GDB now looks for names of Python scripts to auto-load in a
1918 special section named `.debug_gdb_scripts', in addition to looking
1919 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1921 * Tracepoint actions were unified with breakpoint commands. In particular,
1922 there are no longer differences in "info break" output for breakpoints and
1923 tracepoints and the "commands" command can be used for both tracepoints and
1924 regular breakpoints.
1928 ARM Symbian arm*-*-symbianelf*
1930 * D language support.
1931 GDB now supports debugging programs written in the D programming
1934 * GDB now supports the extended ptrace interface for PowerPC which is
1935 available since Linux kernel version 2.6.34. This automatically enables
1936 any hardware breakpoints and additional hardware watchpoints available in
1937 the processor. The old ptrace interface exposes just one hardware
1938 watchpoint and no hardware breakpoints.
1940 * GDB is now able to use the Data Value Compare (DVC) register available on
1941 embedded PowerPC processors to implement in hardware simple watchpoint
1942 conditions of the form:
1944 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1946 This works in native GDB running on Linux kernels with the extended ptrace
1947 interface mentioned above.
1949 *** Changes in GDB 7.1
1953 ** Namespace Support
1955 GDB now supports importing of namespaces in C++. This enables the
1956 user to inspect variables from imported namespaces. Support for
1957 namepace aliasing has also been added. So, if a namespace is
1958 aliased in the current scope (e.g. namepace C=A; ) the user can
1959 print variables using the alias (e.g. (gdb) print C::x).
1963 All known bugs relating to the printing of virtual base class were
1964 fixed. It is now possible to call overloaded static methods using a
1969 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1970 and reinterpret_cast<> are now handled by the C++ expression parser.
1974 Xilinx MicroBlaze microblaze-*-*
1979 Xilinx MicroBlaze microblaze
1982 * Multi-program debugging.
1984 GDB now has support for multi-program (a.k.a. multi-executable or
1985 multi-exec) debugging. This allows for debugging multiple inferiors
1986 simultaneously each running a different program under the same GDB
1987 session. See "Debugging Multiple Inferiors and Programs" in the
1988 manual for more information. This implied some user visible changes
1989 in the multi-inferior support. For example, "info inferiors" now
1990 lists inferiors that are not running yet or that have exited
1991 already. See also "New commands" and "New options" below.
1993 * New tracing features
1995 GDB's tracepoint facility now includes several new features:
1997 ** Trace state variables
1999 GDB tracepoints now include support for trace state variables, which
2000 are variables managed by the target agent during a tracing
2001 experiment. They are useful for tracepoints that trigger each
2002 other, so for instance one tracepoint can count hits in a variable,
2003 and then a second tracepoint has a condition that is true when the
2004 count reaches a particular value. Trace state variables share the
2005 $-syntax of GDB convenience variables, and can appear in both
2006 tracepoint actions and condition expressions. Use the "tvariable"
2007 command to create, and "info tvariables" to view; see "Trace State
2008 Variables" in the manual for more detail.
2012 GDB now includes an option for defining fast tracepoints, which
2013 targets may implement more efficiently, such as by installing a jump
2014 into the target agent rather than a trap instruction. The resulting
2015 speedup can be by two orders of magnitude or more, although the
2016 tradeoff is that some program locations on some target architectures
2017 might not allow fast tracepoint installation, for instance if the
2018 instruction to be replaced is shorter than the jump. To request a
2019 fast tracepoint, use the "ftrace" command, with syntax identical to
2020 the regular trace command.
2022 ** Disconnected tracing
2024 It is now possible to detach GDB from the target while it is running
2025 a trace experiment, then reconnect later to see how the experiment
2026 is going. In addition, a new variable disconnected-tracing lets you
2027 tell the target agent whether to continue running a trace if the
2028 connection is lost unexpectedly.
2032 GDB now has the ability to save the trace buffer into a file, and
2033 then use that file as a target, similarly to you can do with
2034 corefiles. You can select trace frames, print data that was
2035 collected in them, and use tstatus to display the state of the
2036 tracing run at the moment that it was saved. To create a trace
2037 file, use "tsave <filename>", and to use it, do "target tfile
2040 ** Circular trace buffer
2042 You can ask the target agent to handle the trace buffer as a
2043 circular buffer, discarding the oldest trace frames to make room for
2044 newer ones, by setting circular-trace-buffer to on. This feature may
2045 not be available for all target agents.
2050 The disassemble command, when invoked with two arguments, now requires
2051 the arguments to be comma-separated.
2054 The info variables command now displays variable definitions. Files
2055 which only declare a variable are not shown.
2058 The source command is now capable of sourcing Python scripts.
2059 This feature is dependent on the debugger being build with Python
2062 Related to this enhancement is also the introduction of a new command
2063 "set script-extension" (see below).
2065 * New commands (for set/show, see "New options" below)
2067 record save [<FILENAME>]
2068 Save a file (in core file format) containing the process record
2069 execution log for replay debugging at a later time.
2071 record restore <FILENAME>
2072 Restore the process record execution log that was saved at an
2073 earlier time, for replay debugging.
2075 add-inferior [-copies <N>] [-exec <FILENAME>]
2078 clone-inferior [-copies <N>] [ID]
2079 Make a new inferior ready to execute the same program another
2080 inferior has loaded.
2085 maint info program-spaces
2086 List the program spaces loaded into GDB.
2088 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2089 show remote interrupt-sequence
2090 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2091 as the sequence to the remote target in order to interrupt the execution.
2092 Ctrl-C is a default. Some system prefers BREAK which is high level of
2093 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2094 Magic SysRq g. It is BREAK signal and character 'g'.
2096 set remote interrupt-on-connect [on | off]
2097 show remote interrupt-on-connect
2098 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2099 remote target when gdb connects to it. This is needed when you debug
2102 set remotebreak [on | off]
2104 Deprecated. Use "set/show remote interrupt-sequence" instead.
2106 tvariable $NAME [ = EXP ]
2107 Create or modify a trace state variable.
2110 List trace state variables and their values.
2112 delete tvariable $NAME ...
2113 Delete one or more trace state variables.
2116 Evaluate the given expressions without collecting anything into the
2117 trace buffer. (Valid in tracepoint actions only.)
2119 ftrace FN / FILE:LINE / *ADDR
2120 Define a fast tracepoint at the given function, line, or address.
2122 * New expression syntax
2124 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2125 GDB now parses 0b101010 identically with 42.
2129 set follow-exec-mode new|same
2130 show follow-exec-mode
2131 Control whether GDB reuses the same inferior across an exec call or
2132 creates a new one. This is useful to be able to restart the old
2133 executable after the inferior having done an exec call.
2135 set default-collect EXPR, ...
2136 show default-collect
2137 Define a list of expressions to be collected at each tracepoint.
2138 This is a useful way to ensure essential items are not overlooked,
2139 such as registers or a critical global variable.
2141 set disconnected-tracing
2142 show disconnected-tracing
2143 If set to 1, the target is instructed to continue tracing if it
2144 loses its connection to GDB. If 0, the target is to stop tracing
2147 set circular-trace-buffer
2148 show circular-trace-buffer
2149 If set to on, the target is instructed to use a circular trace buffer
2150 and discard the oldest trace frames instead of stopping the trace due
2151 to a full trace buffer. If set to off, the trace stops when the buffer
2152 fills up. Some targets may not support this.
2154 set script-extension off|soft|strict
2155 show script-extension
2156 If set to "off", the debugger does not perform any script language
2157 recognition, and all sourced files are assumed to be GDB scripts.
2158 If set to "soft" (the default), files are sourced according to
2159 filename extension, falling back to GDB scripts if the first
2161 If set to "strict", files are sourced according to filename extension.
2163 set ada trust-PAD-over-XVS on|off
2164 show ada trust-PAD-over-XVS
2165 If off, activate a workaround against a bug in the debugging information
2166 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2167 the GCC sources for more information about the GNAT encoding and
2168 PAD types in particular). It is always safe to set this option to
2169 off, but this introduces a slight performance penalty. The default
2172 * Python API Improvements
2174 ** GDB provides the new class gdb.LazyString. This is useful in
2175 some pretty-printing cases. The new method gdb.Value.lazy_string
2176 provides a simple way to create objects of this type.
2178 ** The fields returned by gdb.Type.fields now have an
2179 `is_base_class' attribute.
2181 ** The new method gdb.Type.range returns the range of an array type.
2183 ** The new method gdb.parse_and_eval can be used to parse and
2184 evaluate an expression.
2186 * New remote packets
2189 Define a trace state variable.
2192 Get the current value of a trace state variable.
2195 Set desired tracing behavior upon disconnection.
2198 Set the trace buffer to be linear or circular.
2201 Get data about the tracepoints currently in use.
2205 Process record now works correctly with hardware watchpoints.
2207 Multiple bug fixes have been made to the mips-irix port, making it
2208 much more reliable. In particular:
2209 - Debugging threaded applications is now possible again. Previously,
2210 GDB would hang while starting the program, or while waiting for
2211 the program to stop at a breakpoint.
2212 - Attaching to a running process no longer hangs.
2213 - An error occurring while loading a core file has been fixed.
2214 - Changing the value of the PC register now works again. This fixes
2215 problems observed when using the "jump" command, or when calling
2216 a function from GDB, or even when assigning a new value to $pc.
2217 - With the "finish" and "return" commands, the return value for functions
2218 returning a small array is now correctly printed.
2219 - It is now possible to break on shared library code which gets executed
2220 during a shared library init phase (code executed while executing
2221 their .init section). Previously, the breakpoint would have no effect.
2222 - GDB is now able to backtrace through the signal handler for
2223 non-threaded programs.
2225 PIE (Position Independent Executable) programs debugging is now supported.
2226 This includes debugging execution of PIC (Position Independent Code) shared
2227 libraries although for that, it should be possible to run such libraries as an
2230 *** Changes in GDB 7.0
2232 * GDB now has an interface for JIT compilation. Applications that
2233 dynamically generate code can create symbol files in memory and register
2234 them with GDB. For users, the feature should work transparently, and
2235 for JIT developers, the interface is documented in the GDB manual in the
2236 "JIT Compilation Interface" chapter.
2238 * Tracepoints may now be conditional. The syntax is as for
2239 breakpoints; either an "if" clause appended to the "trace" command,
2240 or the "condition" command is available. GDB sends the condition to
2241 the target for evaluation using the same bytecode format as is used
2242 for tracepoint actions.
2244 * The disassemble command now supports: an optional /r modifier, print the
2245 raw instructions in hex as well as in symbolic form, and an optional /m
2246 modifier to print mixed source+assembly.
2248 * Process record and replay
2250 In a architecture environment that supports ``process record and
2251 replay'', ``process record and replay'' target can record a log of
2252 the process execution, and replay it with both forward and reverse
2255 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2256 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2257 set execution-direction {forward|reverse}, for targets that support
2260 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2261 feature is available with a native GDB running on kernel version
2264 * GDB now has support for multi-byte and wide character sets on the
2265 target. Strings whose character type is wchar_t, char16_t, or
2266 char32_t are now correctly printed. GDB supports wide- and unicode-
2267 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2268 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2269 `printf'. This feature requires iconv to work properly; if your
2270 system does not have a working iconv, GDB can use GNU libiconv. See
2271 the installation instructions for more information.
2273 * GDB now supports automatic retrieval of shared library files from
2274 remote targets. To use this feature, specify a system root that begins
2275 with the `remote:' prefix, either via the `set sysroot' command or via
2276 the `--with-sysroot' configure-time option.
2278 * "info sharedlibrary" now takes an optional regex of libraries to show,
2279 and it now reports if a shared library has no debugging information.
2281 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2282 now complete on file names.
2284 * When completing in expressions, gdb will attempt to limit
2285 completions to allowable structure or union fields, where appropriate.
2286 For instance, consider:
2288 # struct example { int f1; double f2; };
2289 # struct example variable;
2292 If the user types TAB at the end of this command line, the available
2293 completions will be "f1" and "f2".
2295 * Inlined functions are now supported. They show up in backtraces, and
2296 the "step", "next", and "finish" commands handle them automatically.
2298 * GDB now supports the token-splicing (##) and stringification (#)
2299 operators when expanding macros. It also supports variable-arity
2302 * GDB now supports inspecting extra signal information, exported by
2303 the new $_siginfo convenience variable. The feature is currently
2304 implemented on linux ARM, i386 and amd64.
2306 * GDB can now display the VFP floating point registers and NEON vector
2307 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2308 can provide these registers (requires Linux 2.6.30 or later). Remote
2309 and simulator targets may also provide them.
2311 * New remote packets
2314 Search memory for a sequence of bytes.
2317 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2318 operation over reliable transport links. Use of this packet is
2319 controlled by the `set remote noack-packet' command.
2322 Kill the process with the specified process ID. Use this in preference
2323 to `k' when multiprocess protocol extensions are supported.
2326 Obtains additional operating system information
2330 Read or write additional signal information.
2332 * Removed remote protocol undocumented extension
2334 An undocumented extension to the remote protocol's `S' stop reply
2335 packet that permited the stub to pass a process id was removed.
2336 Remote servers should use the `T' stop reply packet instead.
2338 * GDB now supports multiple function calling conventions according to the
2339 DWARF-2 DW_AT_calling_convention function attribute.
2341 * The SH target utilizes the aforementioned change to distinguish between gcc
2342 and Renesas calling convention. It also adds the new CLI commands
2343 `set/show sh calling-convention'.
2345 * GDB can now read compressed debug sections, as produced by GNU gold
2346 with the --compress-debug-sections=zlib flag.
2348 * 64-bit core files are now supported on AIX.
2350 * Thread switching is now supported on Tru64.
2352 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2353 which will be allocated using malloc later in program execution.
2355 * The qXfer:libraries:read remote procotol packet now allows passing a
2356 list of section offsets.
2358 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2359 conditions handling signals delivered during attach or thread creation
2360 have also been fixed.
2362 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2363 From the user's standpoint, all unqualified instances of True and False
2364 are treated as the standard definitions, regardless of context.
2366 * GDB now parses C++ symbol and type names more flexibly. For
2369 template<typename T> class C { };
2372 GDB will now correctly handle all of:
2374 ptype C<char const *>
2375 ptype C<char const*>
2376 ptype C<const char *>
2377 ptype C<const char*>
2379 * New features in the GDB remote stub, gdbserver
2381 - The "--wrapper" command-line argument tells gdbserver to use a
2382 wrapper program to launch programs for debugging.
2384 - On PowerPC and S/390 targets, it is now possible to use a single
2385 gdbserver executable to debug both 32-bit and 64-bit programs.
2386 (This requires gdbserver itself to be built as a 64-bit executable.)
2388 - gdbserver uses the new noack protocol mode for TCP connections to
2389 reduce communications latency, if also supported and enabled in GDB.
2391 - Support for the sparc64-linux-gnu target is now included in
2394 - The amd64-linux build of gdbserver now supports debugging both
2395 32-bit and 64-bit programs.
2397 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2398 now support hardware watchpoints, and will use them automatically
2403 GDB now has support for scripting using Python. Whether this is
2404 available is determined at configure time.
2406 New GDB commands can now be written in Python.
2408 * Ada tasking support
2410 Ada tasks can now be inspected in GDB. The following commands have
2414 Print the list of Ada tasks.
2416 Print detailed information about task number N.
2418 Print the task number of the current task.
2420 Switch the context of debugging to task number N.
2422 * Support for user-defined prefixed commands. The "define" command can
2423 add new commands to existing prefixes, e.g. "target".
2425 * Multi-inferior, multi-process debugging.
2427 GDB now has generalized support for multi-inferior debugging. See
2428 "Debugging Multiple Inferiors" in the manual for more information.
2429 Although availability still depends on target support, the command
2430 set is more uniform now. The GNU/Linux specific multi-forks support
2431 has been migrated to this new framework. This implied some user
2432 visible changes; see "New commands" and also "Removed commands"
2435 * Target descriptions can now describe the target OS ABI. See the
2436 "Target Description Format" section in the user manual for more
2439 * Target descriptions can now describe "compatible" architectures
2440 to indicate that the target can execute applications for a different
2441 architecture in addition to those for the main target architecture.
2442 See the "Target Description Format" section in the user manual for
2445 * Multi-architecture debugging.
2447 GDB now includes general supports for debugging applications on
2448 hybrid systems that use more than one single processor architecture
2449 at the same time. Each such hybrid architecture still requires
2450 specific support to be added. The only hybrid architecture supported
2451 in this version of GDB is the Cell Broadband Engine.
2453 * GDB now supports integrated debugging of Cell/B.E. applications that
2454 use both the PPU and SPU architectures. To enable support for hybrid
2455 Cell/B.E. debugging, you need to configure GDB to support both the
2456 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2457 --enable-targets configure option.
2459 * Non-stop mode debugging.
2461 For some targets, GDB now supports an optional mode of operation in
2462 which you can examine stopped threads while other threads continue
2463 to execute freely. This is referred to as non-stop mode, with the
2464 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2465 section in the user manual for more information.
2467 To be able to support remote non-stop debugging, a remote stub needs
2468 to implement the non-stop mode remote protocol extensions, as
2469 described in the "Remote Non-Stop" section of the user manual. The
2470 GDB remote stub, gdbserver, has been adjusted to support these
2471 extensions on linux targets.
2473 * New commands (for set/show, see "New options" below)
2475 catch syscall [NAME(S) | NUMBER(S)]
2476 Catch system calls. Arguments, which should be names of system
2477 calls or their numbers, mean catch only those syscalls. Without
2478 arguments, every syscall will be caught. When the inferior issues
2479 any of the specified syscalls, GDB will stop and announce the system
2480 call, both when it is called and when its call returns. This
2481 feature is currently available with a native GDB running on the
2482 Linux Kernel, under the following architectures: x86, x86_64,
2483 PowerPC and PowerPC64.
2485 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2487 Search memory for a sequence of bytes.
2489 maint set python print-stack
2490 maint show python print-stack
2491 Show a stack trace when an error is encountered in a Python script.
2494 Invoke CODE by passing it to the Python interpreter.
2499 These allow macros to be defined, undefined, and listed
2503 Show operating system information about processes.
2506 List the inferiors currently under GDB's control.
2509 Switch focus to inferior number NUM.
2512 Detach from inferior number NUM.
2515 Kill inferior number NUM.
2519 set spu stop-on-load
2520 show spu stop-on-load
2521 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2523 set spu auto-flush-cache
2524 show spu auto-flush-cache
2525 Control whether to automatically flush the software-managed cache
2526 during Cell/B.E. debugging.
2528 set sh calling-convention
2529 show sh calling-convention
2530 Control the calling convention used when calling SH target functions.
2533 show debug timestamp
2534 Control display of timestamps with GDB debugging output.
2536 set disassemble-next-line
2537 show disassemble-next-line
2538 Control display of disassembled source lines or instructions when
2541 set remote noack-packet
2542 show remote noack-packet
2543 Set/show the use of remote protocol QStartNoAckMode packet. See above
2544 under "New remote packets."
2546 set remote query-attached-packet
2547 show remote query-attached-packet
2548 Control use of remote protocol `qAttached' (query-attached) packet.
2550 set remote read-siginfo-object
2551 show remote read-siginfo-object
2552 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2555 set remote write-siginfo-object
2556 show remote write-siginfo-object
2557 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2560 set remote reverse-continue
2561 show remote reverse-continue
2562 Control use of remote protocol 'bc' (reverse-continue) packet.
2564 set remote reverse-step
2565 show remote reverse-step
2566 Control use of remote protocol 'bs' (reverse-step) packet.
2568 set displaced-stepping
2569 show displaced-stepping
2570 Control displaced stepping mode. Displaced stepping is a way to
2571 single-step over breakpoints without removing them from the debuggee.
2572 Also known as "out-of-line single-stepping".
2575 show debug displaced
2576 Control display of debugging info for displaced stepping.
2578 maint set internal-error
2579 maint show internal-error
2580 Control what GDB does when an internal error is detected.
2582 maint set internal-warning
2583 maint show internal-warning
2584 Control what GDB does when an internal warning is detected.
2589 Use a wrapper program to launch programs for debugging.
2591 set multiple-symbols (all|ask|cancel)
2592 show multiple-symbols
2593 The value of this variable can be changed to adjust the debugger behavior
2594 when an expression or a breakpoint location contains an ambiguous symbol
2595 name (an overloaded function name, for instance).
2597 set breakpoint always-inserted
2598 show breakpoint always-inserted
2599 Keep breakpoints always inserted in the target, as opposed to inserting
2600 them when resuming the target, and removing them when the target stops.
2601 This option can improve debugger performance on slow remote targets.
2603 set arm fallback-mode (arm|thumb|auto)
2604 show arm fallback-mode
2605 set arm force-mode (arm|thumb|auto)
2607 These commands control how ARM GDB determines whether instructions
2608 are ARM or Thumb. The default for both settings is auto, which uses
2609 the current CPSR value for instructions without symbols; previous
2610 versions of GDB behaved as if "set arm fallback-mode arm".
2612 set disable-randomization
2613 show disable-randomization
2614 Standalone programs run with the virtual address space randomization enabled
2615 by default on some platforms. This option keeps the addresses stable across
2616 multiple debugging sessions.
2620 Control whether other threads are stopped or not when some thread hits
2625 Requests that asynchronous execution is enabled in the target, if available.
2626 In this case, it's possible to resume target in the background, and interact
2627 with GDB while the target is running. "show target-async" displays the
2628 current state of asynchronous execution of the target.
2630 set target-wide-charset
2631 show target-wide-charset
2632 The target-wide-charset is the name of the character set that GDB
2633 uses when printing characters whose type is wchar_t.
2635 set tcp auto-retry (on|off)
2637 set tcp connect-timeout
2638 show tcp connect-timeout
2639 These commands allow GDB to retry failed TCP connections to a remote stub
2640 with a specified timeout period; this is useful if the stub is launched
2641 in parallel with GDB but may not be ready to accept connections immediately.
2643 set libthread-db-search-path
2644 show libthread-db-search-path
2645 Control list of directories which GDB will search for appropriate
2648 set schedule-multiple (on|off)
2649 show schedule-multiple
2650 Allow GDB to resume all threads of all processes or only threads of
2651 the current process.
2655 Use more aggressive caching for accesses to the stack. This improves
2656 performance of remote debugging (particularly backtraces) without
2657 affecting correctness.
2659 set interactive-mode (on|off|auto)
2660 show interactive-mode
2661 Control whether GDB runs in interactive mode (on) or not (off).
2662 When in interactive mode, GDB waits for the user to answer all
2663 queries. Otherwise, GDB does not wait and assumes the default
2664 answer. When set to auto (the default), GDB determines which
2665 mode to use based on the stdin settings.
2670 For program forks, this is replaced by the new more generic `info
2671 inferiors' command. To list checkpoints, you can still use the
2672 `info checkpoints' command, which was an alias for the `info forks'
2676 Replaced by the new `inferior' command. To switch between
2677 checkpoints, you can still use the `restart' command, which was an
2678 alias for the `fork' command.
2681 This is removed, since some targets don't have a notion of
2682 processes. To switch between processes, you can still use the
2683 `inferior' command using GDB's own inferior number.
2686 For program forks, this is replaced by the new more generic `kill
2687 inferior' command. To delete a checkpoint, you can still use the
2688 `delete checkpoint' command, which was an alias for the `delete
2692 For program forks, this is replaced by the new more generic `detach
2693 inferior' command. To detach a checkpoint, you can still use the
2694 `detach checkpoint' command, which was an alias for the `detach
2697 * New native configurations
2699 x86/x86_64 Darwin i[34567]86-*-darwin*
2701 x86_64 MinGW x86_64-*-mingw*
2705 Lattice Mico32 lm32-*
2706 x86 DICOS i[34567]86-*-dicos*
2707 x86_64 DICOS x86_64-*-dicos*
2710 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2711 (mingw32ce) debugging.
2717 These commands were actually not implemented on any target.
2719 *** Changes in GDB 6.8
2721 * New native configurations
2723 NetBSD/hppa hppa*-*netbsd*
2724 Xtensa GNU/Linux xtensa*-*-linux*
2728 NetBSD/hppa hppa*-*-netbsd*
2729 Xtensa GNU/Lunux xtensa*-*-linux*
2731 * Change in command line behavior -- corefiles vs. process ids.
2733 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2734 attaching to process NUMBER fails, GDB no longer attempts to open a
2735 core file named NUMBER. Attaching to a program using the -c option
2736 is no longer supported. Instead, use the '-p' or '--pid' options.
2738 * GDB can now be built as a native debugger for debugging Windows x86
2739 (mingw32) Portable Executable (PE) programs.
2741 * Pending breakpoints no longer change their number when their address
2744 * GDB now supports breakpoints with multiple locations,
2745 including breakpoints on C++ constructors, inside C++ templates,
2746 and in inlined functions.
2748 * GDB's ability to debug optimized code has been improved. GDB more
2749 accurately identifies function bodies and lexical blocks that occupy
2750 more than one contiguous range of addresses.
2752 * Target descriptions can now describe registers for PowerPC.
2754 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2755 registers on PowerPC targets.
2757 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2758 targets even when the libthread_db library is not available.
2760 * The GDB remote stub, gdbserver, now supports the new file transfer
2761 commands (remote put, remote get, and remote delete).
2763 * The GDB remote stub, gdbserver, now supports run and attach in
2764 extended-remote mode.
2766 * hppa*64*-*-hpux11* target broken
2767 The debugger is unable to start a program and fails with the following
2768 error: "Error trying to get information about dynamic linker".
2769 The gdb-6.7 release is also affected.
2771 * GDB now supports the --enable-targets= configure option to allow
2772 building a single GDB executable that supports multiple remote
2773 target architectures.
2775 * GDB now supports debugging C and C++ programs which use the
2776 Decimal Floating Point extension. In addition, the PowerPC target
2777 now has a set of pseudo-registers to inspect decimal float values
2778 stored in two consecutive float registers.
2780 * The -break-insert MI command can optionally create pending
2783 * Improved support for debugging Ada
2784 Many improvements to the Ada language support have been made. These
2786 - Better support for Ada2005 interface types
2787 - Improved handling of arrays and slices in general
2788 - Better support for Taft-amendment types
2789 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2791 - Improved command completion in Ada
2794 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2799 set print frame-arguments (all|scalars|none)
2800 show print frame-arguments
2801 The value of this variable can be changed to control which argument
2802 values should be printed by the debugger when displaying a frame.
2807 Transfer files to and from a remote target, and delete remote files.
2814 Transfer files to and from a remote target, and delete remote files.
2816 * New remote packets
2823 Open, close, read, write, and delete files on the remote system.
2826 Attach to an existing process on the remote system, in extended-remote
2830 Run a new process on the remote system, in extended-remote mode.
2832 *** Changes in GDB 6.7
2834 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2835 bfd, libiberty and opcodes, as revealed by static analysis donated by
2836 Coverity, Inc. (http://scan.coverity.com).
2838 * When looking up multiply-defined global symbols, GDB will now prefer the
2839 symbol definition in the current shared library if it was built using the
2840 -Bsymbolic linker option.
2842 * When the Text User Interface (TUI) is not configured, GDB will now
2843 recognize the -tui command-line option and print a message that the TUI
2846 * The GDB remote stub, gdbserver, now has lower overhead for high
2847 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2849 * GDB for MIPS targets now autodetects whether a remote target provides
2850 32-bit or 64-bit register values.
2852 * Support for C++ member pointers has been improved.
2854 * GDB now understands XML target descriptions, which specify the
2855 target's overall architecture. GDB can read a description from
2856 a local file or over the remote serial protocol.
2858 * Vectors of single-byte data use a new integer type which is not
2859 automatically displayed as character or string data.
2861 * The /s format now works with the print command. It displays
2862 arrays of single-byte integers and pointers to single-byte integers
2865 * Target descriptions can now describe target-specific registers,
2866 for architectures which have implemented the support (currently
2867 only ARM, M68K, and MIPS).
2869 * GDB and the GDB remote stub, gdbserver, now support the XScale
2872 * The GDB remote stub, gdbserver, has been updated to support
2873 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2874 has been rewritten to use the standard GDB remote protocol.
2876 * GDB can now step into C++ functions which are called through thunks.
2878 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2880 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2881 layout. It also supports a TextSeg= and DataSeg= response when only
2882 segment base addresses (rather than offsets) are available.
2884 * The /i format now outputs any trailing branch delay slot instructions
2885 immediately following the last instruction within the count specified.
2887 * The GDB remote protocol "T" stop reply packet now supports a
2888 "library" response. Combined with the new "qXfer:libraries:read"
2889 packet, this response allows GDB to debug shared libraries on targets
2890 where the operating system manages the list of loaded libraries (e.g.
2891 Windows and SymbianOS).
2893 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2894 (DLLs) on Windows and Windows CE targets.
2896 * GDB now supports a faster verification that a .debug file matches its binary
2897 according to its build-id signature, if the signature is present.
2903 Enable or disable hardware flow control (RTS/CTS) on the serial port
2904 when debugging using remote targets.
2906 set mem inaccessible-by-default
2907 show mem inaccessible-by-default
2908 If the target supplies a memory map, for instance via the remote
2909 protocol's "qXfer:memory-map:read" packet, setting this variable
2910 prevents GDB from accessing memory outside the memory map. This
2911 is useful for targets with memory mapped registers or which react
2912 badly to accesses of unmapped address space.
2914 set breakpoint auto-hw
2915 show breakpoint auto-hw
2916 If the target supplies a memory map, for instance via the remote
2917 protocol's "qXfer:memory-map:read" packet, setting this variable
2918 lets GDB use hardware breakpoints automatically for memory regions
2919 where it can not use software breakpoints. This covers both the
2920 "break" command and internal breakpoints used for other commands
2921 including "next" and "finish".
2924 catch exception unhandled
2925 Stop the program execution when Ada exceptions are raised.
2928 Stop the program execution when an Ada assertion failed.
2932 Set an alternate system root for target files. This is a more
2933 general version of "set solib-absolute-prefix", which is now
2934 an alias to "set sysroot".
2937 Provide extended SPU facility status information. This set of
2938 commands is available only when debugging the Cell/B.E. SPU
2941 * New native configurations
2943 OpenBSD/sh sh*-*openbsd*
2946 unset tdesc filename
2948 Use the specified local file as an XML target description, and do
2949 not query the target for its built-in description.
2953 OpenBSD/sh sh*-*-openbsd*
2954 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2955 Toshiba Media Processor mep-elf
2957 * New remote packets
2960 Ignore the specified signals; pass them directly to the debugged program
2961 without stopping other threads or reporting them to GDB.
2963 qXfer:features:read:
2964 Read an XML target description from the target, which describes its
2969 Read or write contents of an spufs file on the target system. These
2970 packets are available only on the Cell/B.E. SPU architecture.
2972 qXfer:libraries:read:
2973 Report the loaded shared libraries. Combined with new "T" packet
2974 response, this packet allows GDB to debug shared libraries on
2975 targets where the operating system manages the list of loaded
2976 libraries (e.g. Windows and SymbianOS).
2980 Support for these obsolete configurations has been removed.
2988 i[34567]86-*-lynxos*
2989 i[34567]86-*-netware*
2990 i[34567]86-*-sco3.2v5*
2991 i[34567]86-*-sco3.2v4*
2993 i[34567]86-*-sysv4.2*
2996 i[34567]86-*-unixware2*
2997 i[34567]86-*-unixware*
3006 * Other removed features
3013 Various m68k-only ROM monitors.
3020 Various Renesas ROM monitors and debugging interfaces for SH and
3025 Support for a Macraigor serial interface to on-chip debugging.
3026 GDB does not directly support the newer parallel or USB
3031 A debug information format. The predecessor to DWARF 2 and
3032 DWARF 3, which are still supported.
3034 Support for the HP aCC compiler on HP-UX/PA-RISC
3036 SOM-encapsulated symbolic debugging information, automatic
3037 invocation of pxdb, and the aCC custom C++ ABI. This does not
3038 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3039 with aCC can still be debugged on an assembly level.
3041 MIPS ".pdr" sections
3043 A MIPS-specific format used to describe stack frame layout
3044 in debugging information.
3048 GDB could work with an older version of Guile to debug
3049 the interpreter and Scheme programs running in it.
3051 set mips stack-arg-size
3052 set mips saved-gpreg-size
3054 Use "set mips abi" to control parameter passing for MIPS.
3056 *** Changes in GDB 6.6
3061 Cell Broadband Engine SPU spu-elf
3063 * GDB can now be configured as a cross-debugger targeting native Windows
3064 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3065 running on a Windows system over TCP/IP to debug Windows programs.
3067 * The GDB remote stub, gdbserver, has been updated to support Windows and
3068 Cygwin debugging. Both single-threaded and multi-threaded programs are
3071 * The "set trust-readonly-sections" command works again. This command was
3072 broken in GDB 6.3, 6.4, and 6.5.
3074 * The "load" command now supports writing to flash memory, if the remote
3075 stub provides the required support.
3077 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3078 longer requires symbolic debug information (e.g. DWARF-2).
3083 unset substitute-path
3084 show substitute-path
3085 Manage a list of substitution rules that GDB uses to rewrite the name
3086 of the directories where the sources are located. This can be useful
3087 for instance when the sources were moved to a different location
3088 between compilation and debugging.
3092 Print each CLI command as it is executed. Each command is prefixed with
3093 a number of `+' symbols representing the nesting depth.
3094 The source command now has a `-v' option to enable the same feature.
3098 The ARM Demon monitor support (RDP protocol, "target rdp").
3100 Kernel Object Display, an embedded debugging feature which only worked with
3101 an obsolete version of Cisco IOS.
3103 The 'set download-write-size' and 'show download-write-size' commands.
3105 * New remote packets
3108 Tell a stub about GDB client features, and request remote target features.
3109 The first feature implemented is PacketSize, which allows the target to
3110 specify the size of packets it can handle - to minimize the number of
3111 packets required and improve performance when connected to a remote
3115 Fetch an OS auxilliary vector from the remote stub. This packet is a
3116 more efficient replacement for qPart:auxv:read.
3118 qXfer:memory-map:read:
3119 Fetch a memory map from the remote stub, including information about
3120 RAM, ROM, and flash memory devices.
3125 Erase and program a flash memory device.
3127 * Removed remote packets
3130 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3131 used it, and only gdbserver implemented it.
3133 *** Changes in GDB 6.5
3137 Renesas M32C/M16C m32c-elf
3139 Morpho Technologies ms1 ms1-elf
3143 init-if-undefined Initialize a convenience variable, but
3144 only if it doesn't already have a value.
3146 The following commands are presently only implemented for native GNU/Linux:
3148 checkpoint Save a snapshot of the program state.
3150 restart <n> Return the program state to a
3151 previously saved state.
3153 info checkpoints List currently saved checkpoints.
3155 delete-checkpoint <n> Delete a previously saved checkpoint.
3157 set|show detach-on-fork Tell gdb whether to detach from a newly
3158 forked process, or to keep debugging it.
3160 info forks List forks of the user program that
3161 are available to be debugged.
3163 fork <n> Switch to debugging one of several
3164 forks of the user program that are
3165 available to be debugged.
3167 delete-fork <n> Delete a fork from the list of forks
3168 that are available to be debugged (and
3169 kill the forked process).
3171 detach-fork <n> Delete a fork from the list of forks
3172 that are available to be debugged (and
3173 allow the process to continue).
3177 Morpho Technologies ms2 ms1-elf
3179 * Improved Windows host support
3181 GDB now builds as a cross debugger hosted on i686-mingw32, including
3182 native console support, and remote communications using either
3183 network sockets or serial ports.
3185 * Improved Modula-2 language support
3187 GDB can now print most types in the Modula-2 syntax. This includes:
3188 basic types, set types, record types, enumerated types, range types,
3189 pointer types and ARRAY types. Procedure var parameters are correctly
3190 printed and hexadecimal addresses and character constants are also
3191 written in the Modula-2 syntax. Best results can be obtained by using
3192 GNU Modula-2 together with the -gdwarf-2 command line option.
3196 The ARM rdi-share module.
3198 The Netware NLM debug server.
3200 *** Changes in GDB 6.4
3202 * New native configurations
3204 OpenBSD/arm arm*-*-openbsd*
3205 OpenBSD/mips64 mips64-*-openbsd*
3209 Morpho Technologies ms1 ms1-elf
3211 * New command line options
3213 --batch-silent As for --batch, but totally silent.
3214 --return-child-result The debugger will exist with the same value
3215 the child (debugged) program exited with.
3216 --eval-command COMMAND, -ex COMMAND
3217 Execute a single GDB CLI command. This may be
3218 specified multiple times and in conjunction
3219 with the --command (-x) option.
3221 * Deprecated commands removed
3223 The following commands, that were deprecated in 2000, have been
3227 set|show arm disassembly-flavor set|show arm disassembler
3228 othernames set arm disassembler
3229 set|show remotedebug set|show debug remote
3230 set|show archdebug set|show debug arch
3231 set|show eventdebug set|show debug event
3234 * New BSD user-level threads support
3236 It is now possible to debug programs using the user-level threads
3237 library on OpenBSD and FreeBSD. Currently supported (target)
3240 FreeBSD/amd64 x86_64-*-freebsd*
3241 FreeBSD/i386 i386-*-freebsd*
3242 OpenBSD/i386 i386-*-openbsd*
3244 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3245 are not yet supported.
3247 * New support for Matsushita MN10300 w/sim added
3248 (Work in progress). mn10300-elf.
3250 * REMOVED configurations and files
3252 VxWorks and the XDR protocol *-*-vxworks
3253 Motorola MCORE mcore-*-*
3254 National Semiconductor NS32000 ns32k-*-*
3256 * New "set print array-indexes" command
3258 After turning this setting "on", GDB prints the index of each element
3259 when displaying arrays. The default is "off" to preserve the previous
3262 * VAX floating point support
3264 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3266 * User-defined command support
3268 In addition to using $arg0..$arg9 for argument passing, it is now possible
3269 to use $argc to determine now many arguments have been passed. See the
3270 section on user-defined commands in the user manual for more information.
3272 *** Changes in GDB 6.3:
3274 * New command line option
3276 GDB now accepts -l followed by a number to set the timeout for remote
3279 * GDB works with GCC -feliminate-dwarf2-dups
3281 GDB now supports a more compact representation of DWARF-2 debug
3282 information using DW_FORM_ref_addr references. These are produced
3283 by GCC with the option -feliminate-dwarf2-dups and also by some
3284 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3285 to use -feliminate-dwarf2-dups.
3287 * Internationalization
3289 When supported by the host system, GDB will be built with
3290 internationalization (libintl). The task of marking up the sources is
3291 continued, we're looking forward to our first translation.
3295 Initial support for debugging programs compiled with the GNAT
3296 implementation of the Ada programming language has been integrated
3297 into GDB. In this release, support is limited to expression evaluation.
3299 * New native configurations
3301 GNU/Linux/m32r m32r-*-linux-gnu
3305 GDB's remote protocol now includes support for the 'p' packet. This
3306 packet is used to fetch individual registers from a remote inferior.
3308 * END-OF-LIFE registers[] compatibility module
3310 GDB's internal register infrastructure has been completely rewritten.
3311 The new infrastructure making possible the implementation of key new
3312 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3315 GDB 6.3 will be the last release to include the the registers[]
3316 compatibility module that allowed out-of-date configurations to
3317 continue to work. This change directly impacts the following
3327 powerpc bdm protocol
3329 Unless there is activity to revive these configurations, they will be
3330 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3332 * OBSOLETE configurations and files
3334 Configurations that have been declared obsolete in this release have
3335 been commented out. Unless there is activity to revive these
3336 configurations, the next release of GDB will have their sources
3337 permanently REMOVED.
3346 *** Changes in GDB 6.2.1:
3348 * MIPS `break main; run' gave an heuristic-fence-post warning
3350 When attempting to run even a simple program, a warning about
3351 heuristic-fence-post being hit would be reported. This problem has
3354 * MIPS IRIX 'long double' crashed GDB
3356 When examining a long double variable, GDB would get a segmentation
3357 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3358 IRIX long double values).
3362 A bug in the VAX stack code was causing problems with the "next"
3363 command. This problem has been fixed.
3365 *** Changes in GDB 6.2:
3367 * Fix for ``many threads''
3369 On GNU/Linux systems that use the NPTL threads library, a program
3370 rapidly creating and deleting threads would confuse GDB leading to the
3373 ptrace: No such process.
3374 thread_db_get_info: cannot get thread info: generic error
3376 This problem has been fixed.
3378 * "-async" and "-noasync" options removed.
3380 Support for the broken "-noasync" option has been removed (it caused
3383 * New ``start'' command.
3385 This command runs the program until the begining of the main procedure.
3387 * New BSD Kernel Data Access Library (libkvm) interface
3389 Using ``target kvm'' it is now possible to debug kernel core dumps and
3390 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3391 platforms. Currently supported (native-only) configurations are:
3393 FreeBSD/amd64 x86_64-*-freebsd*
3394 FreeBSD/i386 i?86-*-freebsd*
3395 NetBSD/i386 i?86-*-netbsd*
3396 NetBSD/m68k m68*-*-netbsd*
3397 NetBSD/sparc sparc-*-netbsd*
3398 OpenBSD/amd64 x86_64-*-openbsd*
3399 OpenBSD/i386 i?86-*-openbsd*
3400 OpenBSD/m68k m68*-openbsd*
3401 OpenBSD/sparc sparc-*-openbsd*
3403 * Signal trampoline code overhauled
3405 Many generic problems with GDB's signal handling code have been fixed.
3406 These include: backtraces through non-contiguous stacks; recognition
3407 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3408 call; backtrace through a signal trampoline; step into and out of
3409 signal handlers; and single-stepping in the signal trampoline.
3411 Please note that kernel bugs are a limiting factor here. These
3412 features have been shown to work on an s390 GNU/Linux system that
3413 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3415 * Cygwin support for DWARF 2 added.
3417 * New native configurations
3419 GNU/Linux/hppa hppa*-*-linux*
3420 OpenBSD/hppa hppa*-*-openbsd*
3421 OpenBSD/m68k m68*-*-openbsd*
3422 OpenBSD/m88k m88*-*-openbsd*
3423 OpenBSD/powerpc powerpc-*-openbsd*
3424 NetBSD/vax vax-*-netbsd*
3425 OpenBSD/vax vax-*-openbsd*
3427 * END-OF-LIFE frame compatibility module
3429 GDB's internal frame infrastructure has been completely rewritten.
3430 The new infrastructure making it possible to support key new features
3431 including DWARF 2 Call Frame Information. To aid in the task of
3432 migrating old configurations to this new infrastructure, a
3433 compatibility module, that allowed old configurations to continue to
3434 work, was also included.
3436 GDB 6.2 will be the last release to include this frame compatibility
3437 module. This change directly impacts the following configurations:
3447 Unless there is activity to revive these configurations, they will be
3448 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3450 * REMOVED configurations and files
3452 Sun 3, running SunOS 3 m68*-*-sunos3*
3453 Sun 3, running SunOS 4 m68*-*-sunos4*
3454 Sun 2, running SunOS 3 m68000-*-sunos3*
3455 Sun 2, running SunOS 4 m68000-*-sunos4*
3456 Motorola 680x0 running LynxOS m68*-*-lynxos*
3457 AT&T 3b1/Unix pc m68*-att-*
3458 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3459 decstation mips-dec-* mips-little-*
3460 riscos mips-*-riscos* mips-*-sysv*
3461 sonymips mips-sony-*
3462 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3464 *** Changes in GDB 6.1.1:
3466 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3468 The TUI (Text-mode User Interface) is now built as part of a default
3469 GDB configuration. It is enabled by either selecting the TUI with the
3470 command line option "-i=tui" or by running the separate "gdbtui"
3471 program. For more information on the TUI, see the manual "Debugging
3474 * Pending breakpoint support (also included in GDB 6.1)
3476 Support has been added to allow you to specify breakpoints in shared
3477 libraries that have not yet been loaded. If a breakpoint location
3478 cannot be found, and the "breakpoint pending" option is set to auto,
3479 GDB queries you if you wish to make the breakpoint pending on a future
3480 shared-library load. If and when GDB resolves the breakpoint symbol,
3481 the pending breakpoint is removed as one or more regular breakpoints
3484 Pending breakpoints are very useful for GCJ Java debugging.
3486 * Fixed ISO-C build problems
3488 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3489 non ISO-C code that stopped them being built using a more strict ISO-C
3490 compiler (e.g., IBM's C compiler).
3492 * Fixed build problem on IRIX 5
3494 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3495 wasn't able to compile compile on an IRIX 5 system.
3497 * Added execute permission to gdb/gdbserver/configure
3499 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3500 permission. This bug would cause configure to fail on a number of
3501 systems (Solaris, IRIX). Ref: server/519.
3503 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3505 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3506 has been updated to use constant array sizes.
3508 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3510 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3511 its generated DWARF Call Frame Info. This encoding was causing GDB to
3512 panic, that panic has been fixed. Ref: gdb/1628.
3514 * Fixed a problem when examining parameters in shared library code.
3516 When examining parameters in optimized shared library code generated
3517 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3518 not available''. GDB now correctly displays the variable's value.
3520 *** Changes in GDB 6.1:
3522 * Removed --with-mmalloc
3524 Support for the mmalloc memory manager has been removed, as it
3525 conflicted with the internal gdb byte cache.
3527 * Changes in AMD64 configurations
3529 The AMD64 target now includes the %cs and %ss registers. As a result
3530 the AMD64 remote protocol has changed; this affects the floating-point
3531 and SSE registers. If you rely on those registers for your debugging,
3532 you should upgrade gdbserver on the remote side.
3534 * Revised SPARC target
3536 The SPARC target has been completely revised, incorporating the
3537 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3538 support for LynxOS and SunOS 4 has been dropped. Calling functions
3539 from within GDB on operating systems with a non-executable stack
3540 (Solaris, OpenBSD) now works.
3544 GDB has a new C++ demangler which does a better job on the mangled
3545 names generated by current versions of g++. It also runs faster, so
3546 with this and other changes gdb should now start faster on large C++
3549 * DWARF 2 Location Expressions
3551 GDB support for location expressions has been extended to support function
3552 arguments and frame bases. Older versions of GDB could crash when they
3555 * C++ nested types and namespaces
3557 GDB's support for nested types and namespaces in C++ has been
3558 improved, especially if you use the DWARF 2 debugging format. (This
3559 is the default for recent versions of GCC on most platforms.)
3560 Specifically, if you have a class "Inner" defined within a class or
3561 namespace "Outer", then GDB realizes that the class's name is
3562 "Outer::Inner", not simply "Inner". This should greatly reduce the
3563 frequency of complaints about not finding RTTI symbols. In addition,
3564 if you are stopped at inside of a function defined within a namespace,
3565 GDB modifies its name lookup accordingly.
3567 * New native configurations
3569 NetBSD/amd64 x86_64-*-netbsd*
3570 OpenBSD/amd64 x86_64-*-openbsd*
3571 OpenBSD/alpha alpha*-*-openbsd*
3572 OpenBSD/sparc sparc-*-openbsd*
3573 OpenBSD/sparc64 sparc64-*-openbsd*
3575 * New debugging protocols
3577 M32R with SDI protocol m32r-*-elf*
3579 * "set prompt-escape-char" command deleted.
3581 The command "set prompt-escape-char" has been deleted. This command,
3582 and its very obscure effet on GDB's prompt, was never documented,
3583 tested, nor mentioned in the NEWS file.
3585 * OBSOLETE configurations and files
3587 Configurations that have been declared obsolete in this release have
3588 been commented out. Unless there is activity to revive these
3589 configurations, the next release of GDB will have their sources
3590 permanently REMOVED.
3592 Sun 3, running SunOS 3 m68*-*-sunos3*
3593 Sun 3, running SunOS 4 m68*-*-sunos4*
3594 Sun 2, running SunOS 3 m68000-*-sunos3*
3595 Sun 2, running SunOS 4 m68000-*-sunos4*
3596 Motorola 680x0 running LynxOS m68*-*-lynxos*
3597 AT&T 3b1/Unix pc m68*-att-*
3598 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3599 decstation mips-dec-* mips-little-*
3600 riscos mips-*-riscos* mips-*-sysv*
3601 sonymips mips-sony-*
3602 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3604 * REMOVED configurations and files
3606 SGI Irix-4.x mips-sgi-irix4 or iris4
3607 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3608 Z8000 simulator z8k-zilog-none or z8ksim
3609 Matsushita MN10200 w/simulator mn10200-*-*
3610 H8/500 simulator h8500-hitachi-hms or h8500hms
3611 HP/PA running BSD hppa*-*-bsd*
3612 HP/PA running OSF/1 hppa*-*-osf*
3613 HP/PA Pro target hppa*-*-pro*
3614 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3615 386BSD i[3456]86-*-bsd*
3616 Sequent family i[3456]86-sequent-sysv4*
3617 i[3456]86-sequent-sysv*
3618 i[3456]86-sequent-bsd*
3619 SPARC running LynxOS sparc-*-lynxos*
3620 SPARC running SunOS 4 sparc-*-sunos4*
3621 Tsqware Sparclet sparclet-*-*
3622 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3624 *** Changes in GDB 6.0:
3628 Support for debugging the Objective-C programming language has been
3629 integrated into GDB.
3631 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3633 DWARF 2's Call Frame Information makes available compiler generated
3634 information that more exactly describes the program's run-time stack.
3635 By using this information, GDB is able to provide more robust stack
3638 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3639 have been updated to use a new backtrace mechanism which includes
3640 DWARF 2 CFI support.
3644 GDB's remote protocol has been extended to include support for hosted
3645 file I/O (where the remote target uses GDB's file system). See GDB's
3646 remote protocol documentation for details.
3648 * All targets using the new architecture framework.
3650 All of GDB's targets have been updated to use the new internal
3651 architecture framework. The way is now open for future GDB releases
3652 to include cross-architecture native debugging support (i386 on amd64,
3655 * GNU/Linux's Thread Local Storage (TLS)
3657 GDB now includes support for for the GNU/Linux implementation of
3658 per-thread variables.
3660 * GNU/Linux's Native POSIX Thread Library (NPTL)
3662 GDB's thread code has been updated to work with either the new
3663 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3665 * Separate debug info.
3667 GDB, in conjunction with BINUTILS, now supports a mechanism for
3668 automatically loading debug information from a separate file. Instead
3669 of shipping full debug and non-debug versions of system libraries,
3670 system integrators can now instead ship just the stripped libraries
3671 and optional debug files.
3673 * DWARF 2 Location Expressions
3675 DWARF 2 Location Expressions allow the compiler to more completely
3676 describe the location of variables (even in optimized code) to the
3679 GDB now includes preliminary support for location expressions (support
3680 for DW_OP_piece is still missing).
3684 A number of long standing bugs that caused GDB to die while starting a
3685 Java application have been fixed. GDB's Java support is now
3686 considered "useable".
3688 * GNU/Linux support for fork, vfork, and exec.
3690 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3691 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3694 * GDB supports logging output to a file
3696 There are two new commands, "set logging" and "show logging", which can be
3697 used to capture GDB's output to a file.
3699 * The meaning of "detach" has changed for gdbserver
3701 The "detach" command will now resume the application, as documented. To
3702 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3705 * d10v, m68hc11 `regs' command deprecated
3707 The `info registers' command has been updated so that it displays the
3708 registers using a format identical to the old `regs' command.
3712 A new command, "maint set profile on/off", has been added. This command can
3713 be used to enable or disable profiling while running GDB, to profile a
3714 session or a set of commands. In addition there is a new configure switch,
3715 "--enable-profiling", which will cause GDB to be compiled with profiling
3716 data, for more informative profiling results.
3718 * Default MI syntax changed to "mi2".
3720 The default MI (machine interface) syntax, enabled by the command line
3721 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3722 "mi1", can be enabled by specifying the option "-i=mi1".
3724 Support for the original "mi0" syntax (included in GDB 5.0) has been
3727 Fix for gdb/192: removed extraneous space when displaying frame level.
3728 Fix for gdb/672: update changelist is now output in mi list format.
3729 Fix for gdb/702: a -var-assign that updates the value now shows up
3730 in a subsequent -var-update.
3732 * New native configurations.
3734 FreeBSD/amd64 x86_64-*-freebsd*
3736 * Multi-arched targets.
3738 HP/PA HPUX11 hppa*-*-hpux*
3739 Renesas M32R/D w/simulator m32r-*-elf*
3741 * OBSOLETE configurations and files
3743 Configurations that have been declared obsolete in this release have
3744 been commented out. Unless there is activity to revive these
3745 configurations, the next release of GDB will have their sources
3746 permanently REMOVED.
3748 Z8000 simulator z8k-zilog-none or z8ksim
3749 Matsushita MN10200 w/simulator mn10200-*-*
3750 H8/500 simulator h8500-hitachi-hms or h8500hms
3751 HP/PA running BSD hppa*-*-bsd*
3752 HP/PA running OSF/1 hppa*-*-osf*
3753 HP/PA Pro target hppa*-*-pro*
3754 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3755 Sequent family i[3456]86-sequent-sysv4*
3756 i[3456]86-sequent-sysv*
3757 i[3456]86-sequent-bsd*
3758 Tsqware Sparclet sparclet-*-*
3759 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3761 * REMOVED configurations and files
3764 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3765 IBM AIX PS/2 i[3456]86-*-aix
3766 i386 running Mach 3.0 i[3456]86-*-mach3*
3767 i386 running Mach i[3456]86-*-mach*
3768 i386 running OSF/1 i[3456]86-*osf1mk*
3769 HP/Apollo 68k Family m68*-apollo*-sysv*,
3771 m68*-hp-bsd*, m68*-hp-hpux*
3772 Argonaut Risc Chip (ARC) arc-*-*
3773 Mitsubishi D30V d30v-*-*
3774 Fujitsu FR30 fr30-*-elf*
3775 OS/9000 i[34]86-*-os9k
3776 I960 with MON960 i960-*-coff
3778 * MIPS $fp behavior changed
3780 The convenience variable $fp, for the MIPS, now consistently returns
3781 the address of the current frame's base. Previously, depending on the
3782 context, $fp could refer to either $sp or the current frame's base
3783 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3784 The GNU Source-Level Debugger''.
3786 *** Changes in GDB 5.3:
3788 * GNU/Linux shared library multi-threaded performance improved.
3790 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3791 `/proc', in preference to `ptrace' for memory reads. This may result
3792 in an improvement in the start-up time of multi-threaded, shared
3793 library applications when run under GDB. One GDB user writes: ``loads
3794 shared libs like mad''.
3796 * ``gdbserver'' now supports multi-threaded applications on some targets
3798 Support for debugging multi-threaded applications which use
3799 the GNU/Linux LinuxThreads package has been added for
3800 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3801 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3803 * GDB now supports C/C++ preprocessor macros.
3805 GDB now expands preprocessor macro invocations in C/C++ expressions,
3806 and provides various commands for showing macro definitions and how
3809 The new command `macro expand EXPRESSION' expands any macro
3810 invocations in expression, and shows the result.
3812 The new command `show macro MACRO-NAME' shows the definition of the
3813 macro named MACRO-NAME, and where it was defined.
3815 Most compilers don't include information about macros in the debugging
3816 information by default. In GCC 3.1, for example, you need to compile
3817 your program with the options `-gdwarf-2 -g3'. If the macro
3818 information is present in the executable, GDB will read it.
3820 * Multi-arched targets.
3822 DEC Alpha (partial) alpha*-*-*
3823 DEC VAX (partial) vax-*-*
3825 National Semiconductor NS32000 (partial) ns32k-*-*
3826 Motorola 68000 (partial) m68k-*-*
3827 Motorola MCORE mcore-*-*
3831 Fujitsu FRV architecture added by Red Hat frv*-*-*
3834 * New native configurations
3836 Alpha NetBSD alpha*-*-netbsd*
3837 SH NetBSD sh*-*-netbsdelf*
3838 MIPS NetBSD mips*-*-netbsd*
3839 UltraSPARC NetBSD sparc64-*-netbsd*
3841 * OBSOLETE configurations and files
3843 Configurations that have been declared obsolete in this release have
3844 been commented out. Unless there is activity to revive these
3845 configurations, the next release of GDB will have their sources
3846 permanently REMOVED.
3848 Mitsubishi D30V d30v-*-*
3849 OS/9000 i[34]86-*-os9k
3850 IBM AIX PS/2 i[3456]86-*-aix
3851 Fujitsu FR30 fr30-*-elf*
3852 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3853 Argonaut Risc Chip (ARC) arc-*-*
3854 i386 running Mach 3.0 i[3456]86-*-mach3*
3855 i386 running Mach i[3456]86-*-mach*
3856 i386 running OSF/1 i[3456]86-*osf1mk*
3857 HP/Apollo 68k Family m68*-apollo*-sysv*,
3859 m68*-hp-bsd*, m68*-hp-hpux*
3860 I960 with MON960 i960-*-coff
3862 * OBSOLETE languages
3864 CHILL, a Pascal like language used by telecommunications companies.
3866 * REMOVED configurations and files
3868 AMD 29k family via UDI a29k-amd-udi, udi29k
3869 A29K VxWorks a29k-*-vxworks
3870 AMD 29000 embedded, using EBMON a29k-none-none
3871 AMD 29000 embedded with COFF a29k-none-coff
3872 AMD 29000 embedded with a.out a29k-none-aout
3874 testsuite/gdb.hp/gdb.threads-hp/ directory
3876 * New command "set max-user-call-depth <nnn>"
3878 This command allows the user to limit the call depth of user-defined
3879 commands. The default is 1024.
3881 * Changes in FreeBSD/i386 native debugging.
3883 Support for the "generate-core-file" has been added.
3885 * New commands "dump", "append", and "restore".
3887 These commands allow data to be copied from target memory
3888 to a bfd-format or binary file (dump and append), and back
3889 from a file into memory (restore).
3891 * Improved "next/step" support on multi-processor Alpha Tru64.
3893 The previous single-step mechanism could cause unpredictable problems,
3894 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3895 of a software single-step mechanism prevents this.
3897 *** Changes in GDB 5.2.1:
3905 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3906 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3907 Fix, by Joel Brobecker imported from mainline.
3909 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3910 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3911 Fix, by Fred Fish, imported from mainline.
3913 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3914 Surprisingly enough, it works now.
3915 By Michal Ludvig, imported from mainline.
3917 i386 hardware watchpoint support:
3918 avoid misses on second run for some targets.
3919 By Pierre Muller, imported from mainline.
3921 *** Changes in GDB 5.2:
3923 * New command "set trust-readonly-sections on[off]".
3925 This command is a hint that tells gdb that read-only sections
3926 really are read-only (ie. that their contents will not change).
3927 In this mode, gdb will go to the object file rather than the
3928 target to read memory from read-only sections (such as ".text").
3929 This can be a significant performance improvement on some
3930 (notably embedded) targets.
3932 * New command "generate-core-file" (or "gcore").
3934 This new gdb command allows the user to drop a core file of the child
3935 process state at any time. So far it's been implemented only for
3936 GNU/Linux and Solaris, but should be relatively easily ported to other
3937 hosts. Argument is core file name (defaults to core.<pid>).
3939 * New command line option
3941 GDB now accepts --pid or -p followed by a process id.
3943 * Change in command line behavior -- corefiles vs. process ids.
3945 There is a subtle behavior in the way in which GDB handles
3946 command line arguments. The first non-flag argument is always
3947 a program to debug, but the second non-flag argument may either
3948 be a corefile or a process id. Previously, GDB would attempt to
3949 open the second argument as a corefile, and if that failed, would
3950 issue a superfluous error message and then attempt to attach it as
3951 a process. Now, if the second argument begins with a non-digit,
3952 it will be treated as a corefile. If it begins with a digit,
3953 GDB will attempt to attach it as a process, and if no such process
3954 is found, will then attempt to open it as a corefile.
3956 * Changes in ARM configurations.
3958 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3959 configuration is fully multi-arch.
3961 * New native configurations
3963 ARM NetBSD arm*-*-netbsd*
3964 x86 OpenBSD i[3456]86-*-openbsd*
3965 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3966 Sparc64 running FreeBSD sparc64-*-freebsd*
3970 Sanyo XStormy16 xstormy16-elf
3972 * OBSOLETE configurations and files
3974 Configurations that have been declared obsolete in this release have
3975 been commented out. Unless there is activity to revive these
3976 configurations, the next release of GDB will have their sources
3977 permanently REMOVED.
3979 AMD 29k family via UDI a29k-amd-udi, udi29k
3980 A29K VxWorks a29k-*-vxworks
3981 AMD 29000 embedded, using EBMON a29k-none-none
3982 AMD 29000 embedded with COFF a29k-none-coff
3983 AMD 29000 embedded with a.out a29k-none-aout
3985 testsuite/gdb.hp/gdb.threads-hp/ directory
3987 * REMOVED configurations and files
3989 TI TMS320C80 tic80-*-*
3991 PowerPC Solaris powerpcle-*-solaris*
3992 PowerPC Windows NT powerpcle-*-cygwin32
3993 PowerPC Netware powerpc-*-netware*
3994 Harris/CXUX m88k m88*-harris-cxux*
3995 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3996 ns32k-utek-sysv* ns32k-utek-*
3997 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3998 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3999 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4000 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4001 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4003 * Changes to command line processing
4005 The new `--args' feature can be used to specify command-line arguments
4006 for the inferior from gdb's command line.
4008 * Changes to key bindings
4010 There is a new `operate-and-get-next' function bound to `C-o'.
4012 *** Changes in GDB 5.1.1
4014 Fix compile problem on DJGPP.
4016 Fix a problem with floating-point registers on the i386 being
4019 Fix to stop GDB crashing on .debug_str debug info.
4021 Numerous documentation fixes.
4023 Numerous testsuite fixes.
4025 *** Changes in GDB 5.1:
4027 * New native configurations
4029 Alpha FreeBSD alpha*-*-freebsd*
4030 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4031 MIPS GNU/Linux mips*-*-linux*
4032 MIPS SGI Irix 6.x mips*-sgi-irix6*
4033 ia64 AIX ia64-*-aix*
4034 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4038 Motorola 68HC11 and 68HC12 m68hc11-elf
4040 UltraSparc running GNU/Linux sparc64-*-linux*
4042 * OBSOLETE configurations and files
4044 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4045 Harris/CXUX m88k m88*-harris-cxux*
4046 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4047 ns32k-utek-sysv* ns32k-utek-*
4048 TI TMS320C80 tic80-*-*
4050 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4051 PowerPC Solaris powerpcle-*-solaris*
4052 PowerPC Windows NT powerpcle-*-cygwin32
4053 PowerPC Netware powerpc-*-netware*
4054 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4055 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4056 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4057 Apple Macintosh (MPW) host N/A
4059 stuff.c (Program to stuff files into a specially prepared space in kdb)
4060 kdb-start.c (Main loop for the standalone kernel debugger)
4062 Configurations that have been declared obsolete in this release have
4063 been commented out. Unless there is activity to revive these
4064 configurations, the next release of GDB will have their sources
4065 permanently REMOVED.
4067 * REMOVED configurations and files
4069 Altos 3068 m68*-altos-*
4070 Convex c1-*-*, c2-*-*
4072 ARM RISCix arm-*-* (as host)
4076 * GDB has been converted to ISO C.
4078 GDB's source code has been converted to ISO C. In particular, the
4079 sources are fully protoized, and rely on standard headers being
4084 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4086 * The MI enabled by default.
4088 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4089 revised and enabled by default. Packages which use GDB as a debugging
4090 engine behind a UI or another front end are encouraged to switch to
4091 using the GDB/MI interface, instead of the old annotations interface
4092 which is now deprecated.
4094 * Support for debugging Pascal programs.
4096 GDB now includes support for debugging Pascal programs. The following
4097 main features are supported:
4099 - Pascal-specific data types such as sets;
4101 - automatic recognition of Pascal sources based on file-name
4104 - Pascal-style display of data types, variables, and functions;
4106 - a Pascal expression parser.
4108 However, some important features are not yet supported.
4110 - Pascal string operations are not supported at all;
4112 - there are some problems with boolean types;
4114 - Pascal type hexadecimal constants are not supported
4115 because they conflict with the internal variables format;
4117 - support for Pascal objects and classes is not full yet;
4119 - unlike Pascal, GDB is case-sensitive for symbol names.
4121 * Changes in completion.
4123 Commands such as `shell', `run' and `set args', which pass arguments
4124 to inferior programs, now complete on file names, similar to what
4125 users expect at the shell prompt.
4127 Commands which accept locations, such as `disassemble', `print',
4128 `breakpoint', `until', etc. now complete on filenames as well as
4129 program symbols. Thus, if you type "break foob TAB", and the source
4130 files linked into the programs include `foobar.c', that file name will
4131 be one of the candidates for completion. However, file names are not
4132 considered for completion after you typed a colon that delimits a file
4133 name from a name of a function in that file, as in "break foo.c:bar".
4135 `set demangle-style' completes on available demangling styles.
4137 * New platform-independent commands:
4139 It is now possible to define a post-hook for a command as well as a
4140 hook that runs before the command. For more details, see the
4141 documentation of `hookpost' in the GDB manual.
4143 * Changes in GNU/Linux native debugging.
4145 Support for debugging multi-threaded programs has been completely
4146 revised for all platforms except m68k and sparc. You can now debug as
4147 many threads as your system allows you to have.
4149 Attach/detach is supported for multi-threaded programs.
4151 Support for SSE registers was added for x86. This doesn't work for
4152 multi-threaded programs though.
4154 * Changes in MIPS configurations.
4156 Multi-arch support is enabled for all MIPS configurations.
4158 GDB can now be built as native debugger on SGI Irix 6.x systems for
4159 debugging n32 executables. (Debugging 64-bit executables is not yet
4162 * Unified support for hardware watchpoints in all x86 configurations.
4164 Most (if not all) native x86 configurations support hardware-assisted
4165 breakpoints and watchpoints in a unified manner. This support
4166 implements debug register sharing between watchpoints, which allows to
4167 put a virtually infinite number of watchpoints on the same address,
4168 and also supports watching regions up to 16 bytes with several debug
4171 The new maintenance command `maintenance show-debug-regs' toggles
4172 debugging print-outs in functions that insert, remove, and test
4173 watchpoints and hardware breakpoints.
4175 * Changes in the DJGPP native configuration.
4177 New command ``info dos sysinfo'' displays assorted information about
4178 the CPU, OS, memory, and DPMI server.
4180 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4181 display information about segment descriptors stored in GDT, LDT, and
4184 New commands ``info dos pde'' and ``info dos pte'' display entries
4185 from Page Directory and Page Tables (for now works with CWSDPMI only).
4186 New command ``info dos address-pte'' displays the Page Table entry for
4187 a given linear address.
4189 GDB can now pass command lines longer than 126 characters to the
4190 program being debugged (requires an update to the libdbg.a library
4191 which is part of the DJGPP development kit).
4193 DWARF2 debug info is now supported.
4195 It is now possible to `step' and `next' through calls to `longjmp'.
4197 * Changes in documentation.
4199 All GDB documentation was converted to GFDL, the GNU Free
4200 Documentation License.
4202 Tracepoints-related commands are now fully documented in the GDB
4205 TUI, the Text-mode User Interface, is now documented in the manual.
4207 Tracepoints-related commands are now fully documented in the GDB
4210 The "GDB Internals" manual now has an index. It also includes
4211 documentation of `ui_out' functions, GDB coding standards, x86
4212 hardware watchpoints, and memory region attributes.
4214 * GDB's version number moved to ``version.in''
4216 The Makefile variable VERSION has been replaced by the file
4217 ``version.in''. People creating GDB distributions should update the
4218 contents of this file.
4222 GUD support is now a standard part of the EMACS distribution.
4224 *** Changes in GDB 5.0:
4226 * Improved support for debugging FP programs on x86 targets
4228 Unified and much-improved support for debugging floating-point
4229 programs on all x86 targets. In particular, ``info float'' now
4230 displays the FP registers in the same format on all x86 targets, with
4231 greater level of detail.
4233 * Improvements and bugfixes in hardware-assisted watchpoints
4235 It is now possible to watch array elements, struct members, and
4236 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4237 on x86 targets no longer erroneously trigger when the address is
4240 * Improvements in the native DJGPP version of GDB
4242 The distribution now includes all the scripts and auxiliary files
4243 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4244 machines ``out of the box''.
4246 The DJGPP version can now debug programs that use signals. It is
4247 possible to catch signals that happened in the debuggee, deliver
4248 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4249 would kill the program being debugged.) Programs that hook hardware
4250 interrupts (keyboard, timer, etc.) can also be debugged.
4252 It is now possible to debug DJGPP programs that redirect their
4253 standard handles or switch them to raw (as opposed to cooked) mode, or
4254 even close them. The command ``run < foo > bar'' works as expected,
4255 and ``info terminal'' reports useful information about the debuggee's
4256 terminal, including raw/cooked mode, redirection, etc.
4258 The DJGPP version now uses termios functions for console I/O, which
4259 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4262 DOS-style file names with drive letters are now fully supported by
4265 It is now possible to debug DJGPP programs that switch their working
4266 directory. It is also possible to rerun the debuggee any number of
4267 times without restarting GDB; thus, you can use the same setup,
4268 breakpoints, etc. for many debugging sessions.
4270 * New native configurations
4272 ARM GNU/Linux arm*-*-linux*
4273 PowerPC GNU/Linux powerpc-*-linux*
4277 Motorola MCore mcore-*-*
4278 x86 VxWorks i[3456]86-*-vxworks*
4279 PowerPC VxWorks powerpc-*-vxworks*
4280 TI TMS320C80 tic80-*-*
4282 * OBSOLETE configurations
4284 Altos 3068 m68*-altos-*
4285 Convex c1-*-*, c2-*-*
4287 ARM RISCix arm-*-* (as host)
4290 Configurations that have been declared obsolete will be commented out,
4291 but the code will be left in place. If there is no activity to revive
4292 these configurations before the next release of GDB, the sources will
4293 be permanently REMOVED.
4295 * Gould support removed
4297 Support for the Gould PowerNode and NP1 has been removed.
4299 * New features for SVR4
4301 On SVR4 native platforms (such as Solaris), if you attach to a process
4302 without first loading a symbol file, GDB will now attempt to locate and
4303 load symbols from the running process's executable file.
4305 * Many C++ enhancements
4307 C++ support has been greatly improved. Overload resolution now works properly
4308 in almost all cases. RTTI support is on the way.
4310 * Remote targets can connect to a sub-program
4312 A popen(3) style serial-device has been added. This device starts a
4313 sub-process (such as a stand-alone simulator) and then communicates
4314 with that. The sub-program to run is specified using the syntax
4315 ``|<program> <args>'' vis:
4317 (gdb) set remotedebug 1
4318 (gdb) target extended-remote |mn10300-elf-sim program-args
4320 * MIPS 64 remote protocol
4322 A long standing bug in the mips64 remote protocol where by GDB
4323 expected certain 32 bit registers (ex SR) to be transfered as 32
4324 instead of 64 bits has been fixed.
4326 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4327 added to provide backward compatibility with older versions of GDB.
4329 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4331 The command ``set remotebinarydownload'' command has been replaced by
4332 ``set remote X-packet''. Other commands in ``set remote'' family
4333 include ``set remote P-packet''.
4335 * Breakpoint commands accept ranges.
4337 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4338 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4339 ``tracepoint passcount'' also accepts a range of tracepoints.
4341 * ``apropos'' command added.
4343 The ``apropos'' command searches through command names and
4344 documentation strings, printing out matches, making it much easier to
4345 try to find a command that does what you are looking for.
4349 A new machine oriented interface (MI) has been added to GDB. This
4350 interface is designed for debug environments running GDB as a separate
4351 process. This is part of the long term libGDB project. See the
4352 "GDB/MI" chapter of the GDB manual for further information. It can be
4353 enabled by configuring with:
4355 .../configure --enable-gdbmi
4357 *** Changes in GDB-4.18:
4359 * New native configurations
4361 HP-UX 10.20 hppa*-*-hpux10.20
4362 HP-UX 11.x hppa*-*-hpux11.0*
4363 M68K GNU/Linux m68*-*-linux*
4367 Fujitsu FR30 fr30-*-elf*
4368 Intel StrongARM strongarm-*-*
4369 Mitsubishi D30V d30v-*-*
4371 * OBSOLETE configurations
4373 Gould PowerNode, NP1 np1-*-*, pn-*-*
4375 Configurations that have been declared obsolete will be commented out,
4376 but the code will be left in place. If there is no activity to revive
4377 these configurations before the next release of GDB, the sources will
4378 be permanently REMOVED.
4382 As a compatibility experiment, GDB's source files buildsym.h and
4383 buildsym.c have been converted to pure standard C, no longer
4384 containing any K&R compatibility code. We believe that all systems in
4385 use today either come with a standard C compiler, or have a GCC port
4386 available. If this is not true, please report the affected
4387 configuration to bug-gdb@gnu.org immediately. See the README file for
4388 information about getting a standard C compiler if you don't have one
4393 GDB now uses readline 2.2.
4395 * set extension-language
4397 You can now control the mapping between filename extensions and source
4398 languages by using the `set extension-language' command. For instance,
4399 you can ask GDB to treat .c files as C++ by saying
4400 set extension-language .c c++
4401 The command `info extensions' lists all of the recognized extensions
4402 and their associated languages.
4404 * Setting processor type for PowerPC and RS/6000
4406 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4407 you can use the `set processor' command to specify what variant of the
4408 PowerPC family you are debugging. The command
4412 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4413 following PowerPC and RS6000 variants:
4415 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4416 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4418 403GC IBM PowerPC 403GC
4419 505 Motorola PowerPC 505
4420 860 Motorola PowerPC 860 or 850
4421 601 Motorola PowerPC 601
4422 602 Motorola PowerPC 602
4423 603 Motorola/IBM PowerPC 603 or 603e
4424 604 Motorola PowerPC 604 or 604e
4425 750 Motorola/IBM PowerPC 750 or 750
4427 At the moment, this command just tells GDB what to name the
4428 special-purpose processor registers. Since almost all the affected
4429 registers are inaccessible to user-level programs, this command is
4430 only useful for remote debugging in its present form.
4434 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4435 more extensive support for HP-UX. Added features include shared
4436 library support, kernel threads and hardware watchpoints for 11.00,
4437 support for HP's ANSI C and C++ compilers, and a compatibility mode
4438 for xdb and dbx commands.
4442 HP's donation includes the new concept of catchpoints, which is a
4443 generalization of the old catch command. On HP-UX, it is now possible
4444 to catch exec, fork, and vfork, as well as library loading.
4446 This means that the existing catch command has changed; its first
4447 argument now specifies the type of catch to be set up. See the
4448 output of "help catch" for a list of catchpoint types.
4450 * Debugging across forks
4452 On HP-UX, you can choose which process to debug when a fork() happens
4457 HP has donated a curses-based terminal user interface (TUI). To get
4458 it, build with --enable-tui. Although this can be enabled for any
4459 configuration, at present it only works for native HP debugging.
4461 * GDB remote protocol additions
4463 A new protocol packet 'X' that writes binary data is now available.
4464 Default behavior is to try 'X', then drop back to 'M' if the stub
4465 fails to respond. The settable variable `remotebinarydownload'
4466 allows explicit control over the use of 'X'.
4468 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4469 full 64-bit address. The command
4471 set remoteaddresssize 32
4473 can be used to revert to the old behaviour. For existing remote stubs
4474 the change should not be noticed, as the additional address information
4477 In order to assist in debugging stubs, you may use the maintenance
4478 command `packet' to send any text string to the stub. For instance,
4480 maint packet heythere
4482 sends the packet "$heythere#<checksum>". Note that it is very easy to
4483 disrupt a debugging session by sending the wrong packet at the wrong
4486 The compare-sections command allows you to compare section data on the
4487 target to what is in the executable file without uploading or
4488 downloading, by comparing CRC checksums.
4490 * Tracing can collect general expressions
4492 You may now collect general expressions at tracepoints. This requires
4493 further additions to the target-side stub; see tracepoint.c and
4494 doc/agentexpr.texi for further details.
4496 * mask-address variable for Mips
4498 For Mips targets, you may control the zeroing of the upper 32 bits of
4499 a 64-bit address by entering `set mask-address on'. This is mainly
4500 of interest to users of embedded R4xxx and R5xxx processors.
4502 * Higher serial baud rates
4504 GDB's serial code now allows you to specify baud rates 57600, 115200,
4505 230400, and 460800 baud. (Note that your host system may not be able
4506 to achieve all of these rates.)
4510 The i960 configuration now includes an initial implementation of a
4511 builtin simulator, contributed by Jim Wilson.
4514 *** Changes in GDB-4.17:
4516 * New native configurations
4518 Alpha GNU/Linux alpha*-*-linux*
4519 Unixware 2.x i[3456]86-unixware2*
4520 Irix 6.x mips*-sgi-irix6*
4521 PowerPC GNU/Linux powerpc-*-linux*
4522 PowerPC Solaris powerpcle-*-solaris*
4523 Sparc GNU/Linux sparc-*-linux*
4524 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4528 Argonaut Risc Chip (ARC) arc-*-*
4529 Hitachi H8/300S h8300*-*-*
4530 Matsushita MN10200 w/simulator mn10200-*-*
4531 Matsushita MN10300 w/simulator mn10300-*-*
4532 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4533 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4534 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4535 Mitsubishi D10V w/simulator d10v-*-*
4536 Mitsubishi M32R/D w/simulator m32r-*-elf*
4537 Tsqware Sparclet sparclet-*-*
4538 NEC V850 w/simulator v850-*-*
4540 * New debugging protocols
4542 ARM with RDI protocol arm*-*-*
4543 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4544 DDB and LSI variants of PMON protocol mips*-*-*
4545 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4546 PowerPC with SDS protocol powerpc{,le}-*-eabi
4547 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4551 All configurations can now understand and use the DWARF 2 debugging
4552 format. The choice is automatic, if the symbol file contains DWARF 2
4557 GDB now includes basic Java language support. This support is
4558 only useful with Java compilers that produce native machine code.
4560 * solib-absolute-prefix and solib-search-path
4562 For SunOS and SVR4 shared libraries, you may now set the prefix for
4563 loading absolute shared library symbol files, and the search path for
4564 locating non-absolute shared library symbol files.
4566 * Live range splitting
4568 GDB can now effectively debug code for which GCC has performed live
4569 range splitting as part of its optimization. See gdb/doc/LRS for
4570 more details on the expected format of the stabs information.
4574 GDB's support for the GNU Hurd, including thread debugging, has been
4575 updated to work with current versions of the Hurd.
4579 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4580 instruction set. ARM GDB automatically detects when Thumb
4581 instructions are in use, and adjusts disassembly and backtracing
4586 GDB's MIPS target configurations now handle the MIP16 16-bit
4591 GDB now includes support for overlays; if an executable has been
4592 linked such that multiple sections are based at the same address, GDB
4593 will decide which section to use for symbolic info. You can choose to
4594 control the decision manually, using overlay commands, or implement
4595 additional target-side support and use "overlay load-target" to bring
4596 in the overlay mapping. Do "help overlay" for more detail.
4600 The command "info symbol <address>" displays information about
4601 the symbol at the specified address.
4605 The standard remote protocol now includes an extension that allows
4606 asynchronous collection and display of trace data. This requires
4607 extensive support in the target-side debugging stub. Tracing mode
4608 includes a new interaction mode in GDB and new commands: see the
4609 file tracepoint.c for more details.
4613 Configurations for embedded MIPS now include a simulator contributed
4614 by Cygnus Solutions. The simulator supports the instruction sets
4615 of most MIPS variants.
4619 Sparc configurations may now include the ERC32 simulator contributed
4620 by the European Space Agency. The simulator is not built into
4621 Sparc targets by default; configure with --enable-sim to include it.
4625 For target configurations that may include multiple variants of a
4626 basic architecture (such as MIPS and SH), you may now set the
4627 architecture explicitly. "set arch" sets, "info arch" lists
4628 the possible architectures.
4630 *** Changes in GDB-4.16:
4632 * New native configurations
4634 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4635 M68K NetBSD m68k-*-netbsd*
4636 PowerPC AIX 4.x powerpc-*-aix*
4637 PowerPC MacOS powerpc-*-macos*
4638 PowerPC Windows NT powerpcle-*-cygwin32
4639 RS/6000 AIX 4.x rs6000-*-aix4*
4643 ARM with RDP protocol arm-*-*
4644 I960 with MON960 i960-*-coff
4645 MIPS VxWorks mips*-*-vxworks*
4646 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4647 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4649 Matra Sparclet sparclet-*-*
4653 The powerpc-eabi configuration now includes the PSIM simulator,
4654 contributed by Andrew Cagney, with assistance from Mike Meissner.
4655 PSIM is a very elaborate model of the PowerPC, including not only
4656 basic instruction set execution, but also details of execution unit
4657 performance and I/O hardware. See sim/ppc/README for more details.
4661 GDB now works with Solaris 2.5.
4663 * Windows 95/NT native
4665 GDB will now work as a native debugger on Windows 95 and Windows NT.
4666 To build it from source, you must use the "gnu-win32" environment,
4667 which uses a DLL to emulate enough of Unix to run the GNU tools.
4668 Further information, binaries, and sources are available at
4669 ftp.cygnus.com, under pub/gnu-win32.
4671 * dont-repeat command
4673 If a user-defined command includes the command `dont-repeat', then the
4674 command will not be repeated if the user just types return. This is
4675 useful if the command is time-consuming to run, so that accidental
4676 extra keystrokes don't run the same command many times.
4678 * Send break instead of ^C
4680 The standard remote protocol now includes an option to send a break
4681 rather than a ^C to the target in order to interrupt it. By default,
4682 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4684 * Remote protocol timeout
4686 The standard remote protocol includes a new variable `remotetimeout'
4687 that allows you to set the number of seconds before GDB gives up trying
4688 to read from the target. The default value is 2.
4690 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4692 By default GDB will automatically keep track of objects as they are
4693 loaded and unloaded by the dynamic linker. By using the command `set
4694 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4695 when shared library events occur, thus allowing you to set breakpoints
4696 in shared libraries which are explicitly loaded by the inferior.
4698 Note this feature does not work on hpux8. On hpux9 you must link
4699 /usr/lib/end.o into your program. This feature should work
4700 automatically on hpux10.
4702 * Irix 5.x hardware watchpoint support
4704 Irix 5 configurations now support the use of hardware watchpoints.
4706 * Mips protocol "SYN garbage limit"
4708 When debugging a Mips target using the `target mips' protocol, you
4709 may set the number of characters that GDB will ignore by setting
4710 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4711 every character. The default value is 1050.
4713 * Recording and replaying remote debug sessions
4715 If you set `remotelogfile' to the name of a file, gdb will write to it
4716 a recording of a remote debug session. This recording may then be
4717 replayed back to gdb using "gdbreplay". See gdbserver/README for
4718 details. This is useful when you have a problem with GDB while doing
4719 remote debugging; you can make a recording of the session and send it
4720 to someone else, who can then recreate the problem.
4722 * Speedups for remote debugging
4724 GDB includes speedups for downloading and stepping MIPS systems using
4725 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4726 and more efficient S-record downloading.
4728 * Memory use reductions and statistics collection
4730 GDB now uses less memory and reports statistics about memory usage.
4731 Try the `maint print statistics' command, for example.
4733 *** Changes in GDB-4.15:
4735 * Psymtabs for XCOFF
4737 The symbol reader for AIX GDB now uses partial symbol tables. This
4738 can greatly improve startup time, especially for large executables.
4740 * Remote targets use caching
4742 Remote targets now use a data cache to speed up communication with the
4743 remote side. The data cache could lead to incorrect results because
4744 it doesn't know about volatile variables, thus making it impossible to
4745 debug targets which use memory mapped I/O devices. `set remotecache
4746 off' turns the the data cache off.
4748 * Remote targets may have threads
4750 The standard remote protocol now includes support for multiple threads
4751 in the target system, using new protocol commands 'H' and 'T'. See
4752 gdb/remote.c for details.
4756 If GDB is configured with `--enable-netrom', then it will include
4757 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4758 acts as though it is a bank of ROM on the target board, but you can
4759 write into it over the network. GDB's support consists only of
4760 support for fast loading into the emulated ROM; to debug, you must use
4761 another protocol, such as standard remote protocol. The usual
4762 sequence is something like
4764 target nrom <netrom-hostname>
4766 target remote <netrom-hostname>:1235
4770 GDB now includes support for the Apple Macintosh, as a host only. It
4771 may be run as either an MPW tool or as a standalone application, and
4772 it can debug through the serial port. All the usual GDB commands are
4773 available, but to the target command, you must supply "serial" as the
4774 device type instead of "/dev/ttyXX". See mpw-README in the main
4775 directory for more information on how to build. The MPW configuration
4776 scripts */mpw-config.in support only a few targets, and only the
4777 mips-idt-ecoff target has been tested.
4781 GDB configuration now uses autoconf. This is not user-visible,
4782 but does simplify configuration and building.
4786 GDB now supports hpux10.
4788 *** Changes in GDB-4.14:
4790 * New native configurations
4792 x86 FreeBSD i[345]86-*-freebsd
4793 x86 NetBSD i[345]86-*-netbsd
4794 NS32k NetBSD ns32k-*-netbsd
4795 Sparc NetBSD sparc-*-netbsd
4799 A29K VxWorks a29k-*-vxworks
4800 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4801 CPU32 EST-300 emulator m68*-*-est*
4802 PowerPC ELF powerpc-*-elf
4805 * Alpha OSF/1 support for procfs
4807 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4808 possible to attach to running processes. As the mounting of the /proc
4809 filesystem is optional on the Alpha, GDB automatically determines
4810 the availability of /proc during startup. This can lead to problems
4811 if /proc is unmounted after GDB has been started.
4813 * Arguments to user-defined commands
4815 User commands may accept up to 10 arguments separated by whitespace.
4816 Arguments are accessed within the user command via $arg0..$arg9. A
4819 print $arg0 + $arg1 + $arg2
4821 To execute the command use:
4824 Defines the command "adder" which prints the sum of its three arguments.
4825 Note the arguments are text substitutions, so they may reference variables,
4826 use complex expressions, or even perform inferior function calls.
4828 * New `if' and `while' commands
4830 This makes it possible to write more sophisticated user-defined
4831 commands. Both commands take a single argument, which is the
4832 expression to evaluate, and must be followed by the commands to
4833 execute, one per line, if the expression is nonzero, the list being
4834 terminated by the word `end'. The `if' command list may include an
4835 `else' word, which causes the following commands to be executed only
4836 if the expression is zero.
4838 * Fortran source language mode
4840 GDB now includes partial support for Fortran 77. It will recognize
4841 Fortran programs and can evaluate a subset of Fortran expressions, but
4842 variables and functions may not be handled correctly. GDB will work
4843 with G77, but does not yet know much about symbols emitted by other
4846 * Better HPUX support
4848 Most debugging facilities now work on dynamic executables for HPPAs
4849 running hpux9 or later. You can attach to running dynamically linked
4850 processes, but by default the dynamic libraries will be read-only, so
4851 for instance you won't be able to put breakpoints in them. To change
4852 that behavior do the following before running the program:
4858 This will cause the libraries to be mapped private and read-write.
4859 To revert to the normal behavior, do this:
4865 You cannot set breakpoints or examine data in the library until after
4866 the library is loaded if the function/data symbols do not have
4869 GDB can now also read debug symbols produced by the HP C compiler on
4870 HPPAs (sorry, no C++, Fortran or 68k support).
4872 * Target byte order now dynamically selectable
4874 You can choose which byte order to use with a target system, via the
4875 commands "set endian big" and "set endian little", and you can see the
4876 current setting by using "show endian". You can also give the command
4877 "set endian auto", in which case GDB will use the byte order
4878 associated with the executable. Currently, only embedded MIPS
4879 configurations support dynamic selection of target byte order.
4881 * New DOS host serial code
4883 This version uses DPMI interrupts to handle buffered I/O, so you
4884 no longer need to run asynctsr when debugging boards connected to
4887 *** Changes in GDB-4.13:
4889 * New "complete" command
4891 This lists all the possible completions for the rest of the line, if it
4892 were to be given as a command itself. This is intended for use by emacs.
4894 * Trailing space optional in prompt
4896 "set prompt" no longer adds a space for you after the prompt you set. This
4897 allows you to set a prompt which ends in a space or one that does not.
4899 * Breakpoint hit counts
4901 "info break" now displays a count of the number of times the breakpoint
4902 has been hit. This is especially useful in conjunction with "ignore"; you
4903 can ignore a large number of breakpoint hits, look at the breakpoint info
4904 to see how many times the breakpoint was hit, then run again, ignoring one
4905 less than that number, and this will get you quickly to the last hit of
4908 * Ability to stop printing at NULL character
4910 "set print null-stop" will cause GDB to stop printing the characters of
4911 an array when the first NULL is encountered. This is useful when large
4912 arrays actually contain only short strings.
4914 * Shared library breakpoints
4916 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4917 breakpoints in shared libraries before the executable is run.
4919 * Hardware watchpoints
4921 There is a new hardware breakpoint for the watch command for sparclite
4922 targets. See gdb/sparclite/hw_breakpoint.note.
4924 Hardware watchpoints are also now supported under GNU/Linux.
4928 Annotations have been added. These are for use with graphical interfaces,
4929 and are still experimental. Currently only gdba.el uses these.
4931 * Improved Irix 5 support
4933 GDB now works properly with Irix 5.2.
4935 * Improved HPPA support
4937 GDB now works properly with the latest GCC and GAS.
4939 * New native configurations
4941 Sequent PTX4 i[34]86-sequent-ptx4
4942 HPPA running OSF/1 hppa*-*-osf*
4943 Atari TT running SVR4 m68*-*-sysv4*
4944 RS/6000 LynxOS rs6000-*-lynxos*
4948 OS/9000 i[34]86-*-os9k
4949 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4952 * Hitachi SH7000 and E7000-PC ICE support
4954 There is now support for communicating with the Hitachi E7000-PC ICE.
4955 This is available automatically when GDB is configured for the SH.
4959 As usual, a variety of small fixes and improvements, both generic
4960 and configuration-specific. See the ChangeLog for more detail.
4962 *** Changes in GDB-4.12:
4964 * Irix 5 is now supported
4968 GDB-4.12 on the HPPA has a number of changes which make it unable
4969 to debug the output from the currently released versions of GCC and
4970 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4971 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4972 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4975 *** Changes in GDB-4.11:
4977 * User visible changes:
4981 The "set remotedebug" option is now consistent between the mips remote
4982 target, remote targets using the gdb-specific protocol, UDI (AMD's
4983 debug protocol for the 29k) and the 88k bug monitor. It is now an
4984 integer specifying a debug level (normally 0 or 1, but 2 means more
4985 debugging info for the mips target).
4987 * DEC Alpha native support
4989 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4990 debug info, but GDB works fairly well with the DEC compiler and should
4991 work with a future GCC release. See the README file for a few
4992 Alpha-specific notes.
4994 * Preliminary thread implementation
4996 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4998 * LynxOS native and target support for 386
5000 This release has been hosted on LynxOS 2.2, and also can be configured
5001 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5004 * Improvements in C++ mangling/demangling.
5006 This release has much better g++ debugging, specifically in name
5007 mangling/demangling, virtual function calls, print virtual table,
5008 call methods, ...etc.
5010 *** Changes in GDB-4.10:
5012 * User visible changes:
5014 Remote debugging using the GDB-specific (`target remote') protocol now
5015 supports the `load' command. This is only useful if you have some
5016 other way of getting the stub to the target system, and you can put it
5017 somewhere in memory where it won't get clobbered by the download.
5019 Filename completion now works.
5021 When run under emacs mode, the "info line" command now causes the
5022 arrow to point to the line specified. Also, "info line" prints
5023 addresses in symbolic form (as well as hex).
5025 All vxworks based targets now support a user settable option, called
5026 vxworks-timeout. This option represents the number of seconds gdb
5027 should wait for responses to rpc's. You might want to use this if
5028 your vxworks target is, perhaps, a slow software simulator or happens
5029 to be on the far side of a thin network line.
5033 This release contains support for using a DEC alpha as a GDB host for
5034 cross debugging. Native alpha debugging is not supported yet.
5037 *** Changes in GDB-4.9:
5041 This is the first GDB release which is accompanied by a matching testsuite.
5042 The testsuite requires installation of dejagnu, which should be available
5043 via ftp from most sites that carry GNU software.
5047 'Cfront' style demangling has had its name changed to 'ARM' style, to
5048 emphasize that it was written from the specifications in the C++ Annotated
5049 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5050 disclaimers, it still generated too much confusion with users attempting to
5051 use gdb with AT&T cfront.
5055 GDB now uses a standard remote interface to a simulator library.
5056 So far, the library contains simulators for the Zilog Z8001/2, the
5057 Hitachi H8/300, H8/500 and Super-H.
5059 * New targets supported
5061 H8/300 simulator h8300-hitachi-hms or h8300hms
5062 H8/500 simulator h8500-hitachi-hms or h8500hms
5063 SH simulator sh-hitachi-hms or sh
5064 Z8000 simulator z8k-zilog-none or z8ksim
5065 IDT MIPS board over serial line mips-idt-ecoff
5067 Cross-debugging to GO32 targets is supported. It requires a custom
5068 version of the i386-stub.c module which is integrated with the
5069 GO32 memory extender.
5071 * New remote protocols
5073 MIPS remote debugging protocol.
5075 * New source languages supported
5077 This version includes preliminary support for Chill, a Pascal like language
5078 used by telecommunications companies. Chill support is also being integrated
5079 into the GNU compiler, but we don't know when it will be publically available.
5082 *** Changes in GDB-4.8:
5084 * HP Precision Architecture supported
5086 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5087 version of this support was available as a set of patches from the
5088 University of Utah. GDB does not support debugging of programs
5089 compiled with the HP compiler, because HP will not document their file
5090 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5091 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5093 Many problems in the preliminary version have been fixed.
5095 * Faster and better demangling
5097 We have improved template demangling and fixed numerous bugs in the GNU style
5098 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5099 character types (wchar_t) are now supported. Demangling of each symbol is now
5100 only done once, and is cached when the symbol table for a file is read in.
5101 This results in a small increase in memory usage for C programs, a moderate
5102 increase in memory usage for C++ programs, and a fantastic speedup in
5105 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5106 from the specifications in the Annotated Reference Manual, which AT&T's
5107 compiler does not actually implement.
5109 * G++ multiple inheritance compiler problem
5111 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5112 inheritance lattices was reworked to properly discover ambiguities. We
5113 recently found an example which causes this new algorithm to fail in a
5114 very subtle way, producing bad debug information for those classes.
5115 The file 'gcc.patch' (in this directory) can be applied to gcc to
5116 circumvent the problem. A future GCC release will contain a complete
5119 The previous G++ debug info problem (mentioned below for the gdb-4.7
5120 release) is fixed in gcc version 2.3.2.
5122 * Improved configure script
5124 The `configure' script will now attempt to guess your system type if
5125 you don't supply a host system type. The old scheme of supplying a
5126 host system triplet is preferable over using this. All the magic is
5127 done in the new `config.guess' script. Examine it for details.
5129 We have also brought our configure script much more in line with the FSF's
5130 version. It now supports the --with-xxx options. In particular,
5131 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5132 The resulting GDB will not be able to read arbitrary object file formats --
5133 only the format ``expected'' to be used on the configured target system.
5134 We hope to make this the default in a future release.
5136 * Documentation improvements
5138 There's new internal documentation on how to modify GDB, and how to
5139 produce clean changes to the code. We implore people to read it
5140 before submitting changes.
5142 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5143 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5144 `info' files are also provided. To build `info' files from scratch,
5145 you will need the latest `makeinfo' release, which will be available in
5146 a future texinfo-X.Y release.
5148 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5149 We're not sure exactly which versions have this problem, but it has
5150 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5151 or better. If that isn't possible, there is a patch in
5152 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5153 around this problem.
5157 GDB now supports array constants that can be used in expressions typed in by
5158 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5159 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5162 The new directory `gdb/sparclite' contains a program that demonstrates
5163 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5165 * New native hosts supported
5167 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5168 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5170 * New targets supported
5172 AMD 29k family via UDI a29k-amd-udi or udi29k
5174 * New file formats supported
5176 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5177 HPUX core files, and SCO 3.2v2 core files.
5181 Attaching to processes now works again; thanks for the many bug reports.
5183 We have also stomped on a bunch of core dumps caused by
5184 printf_filtered("%s") problems.
5186 We eliminated a copyright problem on the rpc and ptrace header files
5187 for VxWorks, which was discovered at the last minute during the 4.7
5188 release. You should now be able to build a VxWorks GDB.
5190 You can now interrupt gdb while an attached process is running. This
5191 will cause the attached process to stop, and give control back to GDB.
5193 We fixed problems caused by using too many file descriptors
5194 for reading symbols from object files and libraries. This was
5195 especially a problem for programs that used many (~100) shared
5198 The `step' command now only enters a subroutine if there is line number
5199 information for the subroutine. Otherwise it acts like the `next'
5200 command. Previously, `step' would enter subroutines if there was
5201 any debugging information about the routine. This avoids problems
5202 when using `cc -g1' on MIPS machines.
5204 * Internal improvements
5206 GDB's internal interfaces have been improved to make it easier to support
5207 debugging of multiple languages in the future.
5209 GDB now uses a common structure for symbol information internally.
5210 Minimal symbols (derived from linkage symbols in object files), partial
5211 symbols (from a quick scan of debug information), and full symbols
5212 contain a common subset of information, making it easier to write
5213 shared code that handles any of them.
5215 * New command line options
5217 We now accept --silent as an alias for --quiet.
5221 The memory-mapped-malloc library is now licensed under the GNU Library
5222 General Public License.
5224 *** Changes in GDB-4.7:
5226 * Host/native/target split
5228 GDB has had some major internal surgery to untangle the support for
5229 hosts and remote targets. Now, when you configure GDB for a remote
5230 target, it will no longer load in all of the support for debugging
5231 local programs on the host. When fully completed and tested, this will
5232 ensure that arbitrary host/target combinations are possible.
5234 The primary conceptual shift is to separate the non-portable code in
5235 GDB into three categories. Host specific code is required any time GDB
5236 is compiled on that host, regardless of the target. Target specific
5237 code relates to the peculiarities of the target, but can be compiled on
5238 any host. Native specific code is everything else: it can only be
5239 built when the host and target are the same system. Child process
5240 handling and core file support are two common `native' examples.
5242 GDB's use of /proc for controlling Unix child processes is now cleaner.
5243 It has been split out into a single module under the `target_ops' vector,
5244 plus two native-dependent functions for each system that uses /proc.
5246 * New hosts supported
5248 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5249 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5250 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5252 * New targets supported
5254 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5255 68030 and CPU32 m68030-*-*, m68332-*-*
5257 * New native hosts supported
5259 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5260 (386bsd is not well tested yet)
5261 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5263 * New file formats supported
5265 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5266 supports reading of `a.out.adobe' object files, which are an a.out
5267 format extended with minimal information about multiple sections.
5271 `show copying' is the same as the old `info copying'.
5272 `show warranty' is the same as `info warrantee'.
5273 These were renamed for consistency. The old commands continue to work.
5275 `info handle' is a new alias for `info signals'.
5277 You can now define pre-command hooks, which attach arbitrary command
5278 scripts to any command. The commands in the hook will be executed
5279 prior to the user's command. You can also create a hook which will be
5280 executed whenever the program stops. See gdb.texinfo.
5284 We now deal with Cfront style name mangling, and can even extract type
5285 info from mangled symbols. GDB can automatically figure out which
5286 symbol mangling style your C++ compiler uses.
5288 Calling of methods and virtual functions has been improved as well.
5292 The crash that occured when debugging Sun Ansi-C compiled binaries is
5293 fixed. This was due to mishandling of the extra N_SO stabs output
5296 We also finally got Ultrix 4.2 running in house, and fixed core file
5297 support, with help from a dozen people on the net.
5299 John M. Farrell discovered that the reason that single-stepping was so
5300 slow on all of the Mips based platforms (primarily SGI and DEC) was
5301 that we were trying to demangle and lookup a symbol used for internal
5302 purposes on every instruction that was being stepped through. Changing
5303 the name of that symbol so that it couldn't be mistaken for a C++
5304 mangled symbol sped things up a great deal.
5306 Rich Pixley sped up symbol lookups in general by getting much smarter
5307 about when C++ symbol mangling is necessary. This should make symbol
5308 completion (TAB on the command line) much faster. It's not as fast as
5309 we'd like, but it's significantly faster than gdb-4.6.
5313 A new user controllable variable 'call_scratch_address' can
5314 specify the location of a scratch area to be used when GDB
5315 calls a function in the target. This is necessary because the
5316 usual method of putting the scratch area on the stack does not work
5317 in systems that have separate instruction and data spaces.
5319 We integrated changes to support the 29k UDI (Universal Debugger
5320 Interface), but discovered at the last minute that we didn't have all
5321 of the appropriate copyright paperwork. We are working with AMD to
5322 resolve this, and hope to have it available soon.
5326 We have sped up the remote serial line protocol, especially for targets
5327 with lots of registers. It now supports a new `expedited status' ('T')
5328 message which can be used in place of the existing 'S' status message.
5329 This allows the remote stub to send only the registers that GDB
5330 needs to make a quick decision about single-stepping or conditional
5331 breakpoints, eliminating the need to fetch the entire register set for
5332 each instruction being stepped through.
5334 The GDB remote serial protocol now implements a write-through cache for
5335 registers, only re-reading the registers if the target has run.
5337 There is also a new remote serial stub for SPARC processors. You can
5338 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5339 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5340 processor with a serial port.
5344 Configure.in files have become much easier to read and modify. A new
5345 `table driven' format makes it more obvious what configurations are
5346 supported, and what files each one uses.
5350 There is a new opcodes library which will eventually contain all of the
5351 disassembly routines and opcode tables. At present, it only contains
5352 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5353 disassembler (binutils/objdump) to share these routines.
5355 The libiberty library is now copylefted under the GNU Library General
5356 Public License. This allows more liberal use, and was done so libg++
5357 can use it. This makes no difference to GDB, since the Library License
5358 grants all the rights from the General Public License.
5362 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5363 reference to the stabs symbol info used by the debugger. It is (as far
5364 as we know) the only published document on this fascinating topic. We
5365 encourage you to read it, compare it to the stabs information on your
5366 system, and send improvements on the document in general (to
5367 bug-gdb@prep.ai.mit.edu).
5369 And, of course, many bugs have been fixed.
5372 *** Changes in GDB-4.6:
5374 * Better support for C++ function names
5376 GDB now accepts as input the "demangled form" of C++ overloaded function
5377 names and member function names, and can do command completion on such names
5378 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5379 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5380 Make use of command completion, it is your friend.
5382 GDB also now accepts a variety of C++ mangled symbol formats. They are
5383 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5384 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5385 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5386 for the list of formats.
5388 * G++ symbol mangling problem
5390 Recent versions of gcc have a bug in how they emit debugging information for
5391 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5392 directory) can be applied to gcc to fix the problem. Alternatively, if you
5393 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5394 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5395 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5398 * New 'maintenance' command
5400 All of the commands related to hacking GDB internals have been moved out of
5401 the main command set, and now live behind the 'maintenance' command. This
5402 can also be abbreviated as 'mt'. The following changes were made:
5404 dump-me -> maintenance dump-me
5405 info all-breakpoints -> maintenance info breakpoints
5406 printmsyms -> maintenance print msyms
5407 printobjfiles -> maintenance print objfiles
5408 printpsyms -> maintenance print psymbols
5409 printsyms -> maintenance print symbols
5411 The following commands are new:
5413 maintenance demangle Call internal GDB demangler routine to
5414 demangle a C++ link name and prints the result.
5415 maintenance print type Print a type chain for a given symbol
5417 * Change to .gdbinit file processing
5419 We now read the $HOME/.gdbinit file before processing the argv arguments
5420 (e.g. reading symbol files or core files). This allows global parameters to
5421 be set, which will apply during the symbol reading. The ./.gdbinit is still
5422 read after argv processing.
5424 * New hosts supported
5426 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5428 GNU/Linux support i386-unknown-linux or linux
5430 We are also including code to support the HP/PA running BSD and HPUX. This
5431 is almost guaranteed not to work, as we didn't have time to test or build it
5432 for this release. We are including it so that the more adventurous (or
5433 masochistic) of you can play with it. We also had major problems with the
5434 fact that the compiler that we got from HP doesn't support the -g option.
5437 * New targets supported
5439 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5441 * More smarts about finding #include files
5443 GDB now remembers the compilation directory for all include files, and for
5444 all files from which C is generated (like yacc and lex sources). This
5445 greatly improves GDB's ability to find yacc/lex sources, and include files,
5446 especially if you are debugging your program from a directory different from
5447 the one that contains your sources.
5449 We also fixed a bug which caused difficulty with listing and setting
5450 breakpoints in include files which contain C code. (In the past, you had to
5451 try twice in order to list an include file that you hadn't looked at before.)
5453 * Interesting infernals change
5455 GDB now deals with arbitrary numbers of sections, where the symbols for each
5456 section must be relocated relative to that section's landing place in the
5457 target's address space. This work was needed to support ELF with embedded
5458 stabs used by Solaris-2.0.
5460 * Bug fixes (of course!)
5462 There have been loads of fixes for the following things:
5463 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5464 i960, stabs, DOS(GO32), procfs, etc...
5466 See the ChangeLog for details.
5468 *** Changes in GDB-4.5:
5470 * New machines supported (host and target)
5472 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5474 SGI Irix-4.x mips-sgi-irix4 or iris4
5476 * New malloc package
5478 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5479 Mmalloc is capable of handling mutiple heaps of memory. It is also
5480 capable of saving a heap to a file, and then mapping it back in later.
5481 This can be used to greatly speedup the startup of GDB by using a
5482 pre-parsed symbol table which lives in a mmalloc managed heap. For
5483 more details, please read mmalloc/mmalloc.texi.
5487 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5488 'help info proc' for details.
5490 * MIPS ecoff symbol table format
5492 The code that reads MIPS symbol table format is now supported on all hosts.
5493 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5496 * File name changes for MS-DOS
5498 Many files in the config directories have been renamed to make it easier to
5499 support GDB on MS-DOSe systems (which have very restrictive file name
5500 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5501 environment) is close to working but has some remaining problems. Note
5502 that debugging of DOS programs is not supported, due to limitations
5503 in the ``operating system'', but it can be used to host cross-debugging.
5505 * Cross byte order fixes
5507 Many fixes have been made to support cross debugging of Sparc and MIPS
5508 targets from hosts whose byte order differs.
5510 * New -mapped and -readnow options
5512 If memory-mapped files are available on your system through the 'mmap'
5513 system call, you can use the -mapped option on the `file' or
5514 `symbol-file' commands to cause GDB to write the symbols from your
5515 program into a reusable file. If the program you are debugging is
5516 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5517 Future GDB debugging sessions will notice the presence of this file,
5518 and will quickly map in symbol information from it, rather than reading
5519 the symbol table from the executable program. Using the '-mapped'
5520 option in a GDB `file' or `symbol-file' command has the same effect as
5521 starting GDB with the '-mapped' command-line option.
5523 You can cause GDB to read the entire symbol table immediately by using
5524 the '-readnow' option with any of the commands that load symbol table
5525 information (or on the GDB command line). This makes the command
5526 slower, but makes future operations faster.
5528 The -mapped and -readnow options are typically combined in order to
5529 build a `fred.syms' file that contains complete symbol information.
5530 A simple GDB invocation to do nothing but build a `.syms' file for future
5533 gdb -batch -nx -mapped -readnow programname
5535 The `.syms' file is specific to the host machine on which GDB is run.
5536 It holds an exact image of GDB's internal symbol table. It cannot be
5537 shared across multiple host platforms.
5539 * longjmp() handling
5541 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5542 siglongjmp() without losing control. This feature has not yet been ported to
5543 all systems. It currently works on many 386 platforms, all MIPS-based
5544 platforms (SGI, DECstation, etc), and Sun3/4.
5548 Preliminary work has been put in to support the new Solaris OS from Sun. At
5549 this time, it can control and debug processes, but it is not capable of
5554 As always, many many bug fixes. The major areas were with g++, and mipsread.
5555 People using the MIPS-based platforms should experience fewer mysterious
5556 crashes and trashed symbol tables.
5558 *** Changes in GDB-4.4:
5560 * New machines supported (host and target)
5562 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5564 BSD Reno on Vax vax-dec-bsd
5565 Ultrix on Vax vax-dec-ultrix
5567 * New machines supported (target)
5569 AMD 29000 embedded, using EBMON a29k-none-none
5573 GDB continues to improve its handling of C++. `References' work better.
5574 The demangler has also been improved, and now deals with symbols mangled as
5575 per the Annotated C++ Reference Guide.
5577 GDB also now handles `stabs' symbol information embedded in MIPS
5578 `ecoff' symbol tables. Since the ecoff format was not easily
5579 extensible to handle new languages such as C++, this appeared to be a
5580 good way to put C++ debugging info into MIPS binaries. This option
5581 will be supported in the GNU C compiler, version 2, when it is
5584 * New features for SVR4
5586 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5587 shared libraries. Debugging dynamically linked programs should present
5588 only minor differences from debugging statically linked programs.
5590 The `info proc' command will print out information about any process
5591 on an SVR4 system (including the one you are debugging). At the moment,
5592 it prints the address mappings of the process.
5594 If you bring up GDB on another SVR4 system, please send mail to
5595 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5597 * Better dynamic linking support in SunOS
5599 Reading symbols from shared libraries which contain debugging symbols
5600 now works properly. However, there remain issues such as automatic
5601 skipping of `transfer vector' code during function calls, which
5602 make it harder to debug code in a shared library, than to debug the
5603 same code linked statically.
5607 GDB is now using the latest `getopt' routines from the FSF. This
5608 version accepts the -- prefix for options with long names. GDB will
5609 continue to accept the old forms (-option and +option) as well.
5610 Various single letter abbreviations for options have been explicity
5611 added to the option table so that they won't get overshadowed in the
5612 future by other options that begin with the same letter.
5616 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5617 Many assorted bugs have been handled. Many more remain to be handled.
5618 See the various ChangeLog files (primarily in gdb and bfd) for details.
5621 *** Changes in GDB-4.3:
5623 * New machines supported (host and target)
5625 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5626 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5627 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5629 * Almost SCO Unix support
5631 We had hoped to support:
5632 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5633 (except for core file support), but we discovered very late in the release
5634 that it has problems with process groups that render gdb unusable. Sorry
5635 about that. I encourage people to fix it and post the fixes.
5637 * Preliminary ELF and DWARF support
5639 GDB can read ELF object files on System V Release 4, and can handle
5640 debugging records for C, in DWARF format, in ELF files. This support
5641 is preliminary. If you bring up GDB on another SVR4 system, please
5642 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5647 GDB now uses the latest `readline' library. One user-visible change
5648 is that two tabs will list possible command completions, which previously
5649 required typing M-? (meta-question mark, or ESC ?).
5653 The `stepi' bug that many of you noticed has been squashed.
5654 Many bugs in C++ have been handled. Many more remain to be handled.
5655 See the various ChangeLog files (primarily in gdb and bfd) for details.
5657 * State of the MIPS world (in case you wondered):
5659 GDB can understand the symbol tables emitted by the compilers
5660 supplied by most vendors of MIPS-based machines, including DEC. These
5661 symbol tables are in a format that essentially nobody else uses.
5663 Some versions of gcc come with an assembler post-processor called
5664 mips-tfile. This program is required if you want to do source-level
5665 debugging of gcc-compiled programs. I believe FSF does not ship
5666 mips-tfile with gcc version 1, but it will eventually come with gcc
5669 Debugging of g++ output remains a problem. g++ version 1.xx does not
5670 really support it at all. (If you're lucky, you should be able to get
5671 line numbers and stack traces to work, but no parameters or local
5672 variables.) With some work it should be possible to improve the
5675 When gcc version 2 is released, you will have somewhat better luck.
5676 However, even then you will get confusing results for inheritance and
5679 We will eventually provide full debugging of g++ output on
5680 DECstations. This will probably involve some kind of stabs-in-ecoff
5681 encapulation, but the details have not been worked out yet.
5684 *** Changes in GDB-4.2:
5686 * Improved configuration
5688 Only one copy of `configure' exists now, and it is not self-modifying.
5689 Porting BFD is simpler.
5693 The `step' and `next' commands now only stop at the first instruction
5694 of a source line. This prevents the multiple stops that used to occur
5695 in switch statements, for-loops, etc. `Step' continues to stop if a
5696 function that has debugging information is called within the line.
5700 Lots of small bugs fixed. More remain.
5702 * New host supported (not target)
5704 Intel 386 PC clone running Mach i386-none-mach
5707 *** Changes in GDB-4.1:
5709 * Multiple source language support
5711 GDB now has internal scaffolding to handle several source languages.
5712 It determines the type of each source file from its filename extension,
5713 and will switch expression parsing and number formatting to match the
5714 language of the function in the currently selected stack frame.
5715 You can also specifically set the language to be used, with
5716 `set language c' or `set language modula-2'.
5720 GDB now has preliminary support for the GNU Modula-2 compiler,
5721 currently under development at the State University of New York at
5722 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5723 continue through the fall of 1991 and into 1992.
5725 Other Modula-2 compilers are currently not supported, and attempting to
5726 debug programs compiled with them will likely result in an error as the
5727 symbol table is read. Feel free to work on it, though!
5729 There are hooks in GDB for strict type checking and range checking,
5730 in the `Modula-2 philosophy', but they do not currently work.
5734 GDB can now write to executable and core files (e.g. patch
5735 a variable's value). You must turn this switch on, specify
5736 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5737 by assigning a new value to a variable. Modifications take
5740 * Automatic SunOS shared library reading
5742 When you run your program, GDB automatically determines where its
5743 shared libraries (if any) have been loaded, and reads their symbols.
5744 The `share' command is no longer needed. This also works when
5745 examining core files.
5749 You can specify the number of lines that the `list' command shows.
5752 * New machines supported (host and target)
5754 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5755 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5756 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5758 * New hosts supported (not targets)
5760 IBM RT/PC: romp-ibm-aix or rtpc
5762 * New targets supported (not hosts)
5764 AMD 29000 embedded with COFF a29k-none-coff
5765 AMD 29000 embedded with a.out a29k-none-aout
5766 Ultracomputer remote kernel debug a29k-nyu-kern
5768 * New remote interfaces
5774 *** Changes in GDB-4.0:
5778 Wide output is wrapped at good places to make the output more readable.
5780 Gdb now supports cross-debugging from a host machine of one type to a
5781 target machine of another type. Communication with the target system
5782 is over serial lines. The ``target'' command handles connecting to the
5783 remote system; the ``load'' command will download a program into the
5784 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5785 also supports debugging of realtime processes running under VxWorks,
5786 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5787 stub on the target system.
5789 New CPUs supported include the AMD 29000 and Intel 960.
5791 GDB now reads object files and symbol tables via a ``binary file''
5792 library, which allows a single copy of GDB to debug programs of multiple
5793 object file types such as a.out and coff.
5795 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5796 refcard.dvi and refcard.ps are available to format it).
5799 * Control-Variable user interface simplified
5801 All variables that control the operation of the debugger can be set
5802 by the ``set'' command, and displayed by the ``show'' command.
5804 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5805 ``Show prompt'' produces the response:
5806 Gdb's prompt is new-gdb=>.
5808 What follows are the NEW set commands. The command ``help set'' will
5809 print a complete list of old and new set commands. ``help set FOO''
5810 will give a longer description of the variable FOO. ``show'' will show
5811 all of the variable descriptions and their current settings.
5813 confirm on/off: Enables warning questions for operations that are
5814 hard to recover from, e.g. rerunning the program while
5815 it is already running. Default is ON.
5817 editing on/off: Enables EMACS style command line editing
5818 of input. Previous lines can be recalled with
5819 control-P, the current line can be edited with control-B,
5820 you can search for commands with control-R, etc.
5823 history filename NAME: NAME is where the gdb command history
5824 will be stored. The default is .gdb_history,
5825 or the value of the environment variable
5828 history size N: The size, in commands, of the command history. The
5829 default is 256, or the value of the environment variable
5832 history save on/off: If this value is set to ON, the history file will
5833 be saved after exiting gdb. If set to OFF, the
5834 file will not be saved. The default is OFF.
5836 history expansion on/off: If this value is set to ON, then csh-like
5837 history expansion will be performed on
5838 command line input. The default is OFF.
5840 radix N: Sets the default radix for input and output. It can be set
5841 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5842 in the current radix, so "set radix 10" is always a no-op.
5844 height N: This integer value is the number of lines on a page. Default
5845 is 24, the current `stty rows'' setting, or the ``li#''
5846 setting from the termcap entry matching the environment
5849 width N: This integer value is the number of characters on a line.
5850 Default is 80, the current `stty cols'' setting, or the ``co#''
5851 setting from the termcap entry matching the environment
5854 Note: ``set screensize'' is obsolete. Use ``set height'' and
5855 ``set width'' instead.
5857 print address on/off: Print memory addresses in various command displays,
5858 such as stack traces and structure values. Gdb looks
5859 more ``symbolic'' if you turn this off; it looks more
5860 ``machine level'' with it on. Default is ON.
5862 print array on/off: Prettyprint arrays. New convenient format! Default
5865 print demangle on/off: Print C++ symbols in "source" form if on,
5868 print asm-demangle on/off: Same, for assembler level printouts
5871 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5874 * Support for Epoch Environment.
5876 The epoch environment is a version of Emacs v18 with windowing. One
5877 new command, ``inspect'', is identical to ``print'', except that if you
5878 are running in the epoch environment, the value is printed in its own
5882 * Support for Shared Libraries
5884 GDB can now debug programs and core files that use SunOS shared libraries.
5885 Symbols from a shared library cannot be referenced
5886 before the shared library has been linked with the program (this
5887 happens after you type ``run'' and before the function main() is entered).
5888 At any time after this linking (including when examining core files
5889 from dynamically linked programs), gdb reads the symbols from each
5890 shared library when you type the ``sharedlibrary'' command.
5891 It can be abbreviated ``share''.
5893 sharedlibrary REGEXP: Load shared object library symbols for files
5894 matching a unix regular expression. No argument
5895 indicates to load symbols for all shared libraries.
5897 info sharedlibrary: Status of loaded shared libraries.
5902 A watchpoint stops execution of a program whenever the value of an
5903 expression changes. Checking for this slows down execution
5904 tremendously whenever you are in the scope of the expression, but is
5905 quite useful for catching tough ``bit-spreader'' or pointer misuse
5906 problems. Some machines such as the 386 have hardware for doing this
5907 more quickly, and future versions of gdb will use this hardware.
5909 watch EXP: Set a watchpoint (breakpoint) for an expression.
5911 info watchpoints: Information about your watchpoints.
5913 delete N: Deletes watchpoint number N (same as breakpoints).
5914 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5915 enable N: Re-enables watchpoint number N (same as breakpoints).
5918 * C++ multiple inheritance
5920 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5923 * C++ exception handling
5925 Gdb now supports limited C++ exception handling. Besides the existing
5926 ability to breakpoint on an exception handler, gdb can breakpoint on
5927 the raising of an exception (before the stack is peeled back to the
5930 catch FOO: If there is a FOO exception handler in the dynamic scope,
5931 set a breakpoint to catch exceptions which may be raised there.
5932 Multiple exceptions (``catch foo bar baz'') may be caught.
5934 info catch: Lists all exceptions which may be caught in the
5935 current stack frame.
5938 * Minor command changes
5940 The command ``call func (arg, arg, ...)'' now acts like the print
5941 command, except it does not print or save a value if the function's result
5942 is void. This is similar to dbx usage.
5944 The ``up'' and ``down'' commands now always print the frame they end up
5945 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5946 frames without printing.
5948 * New directory command
5950 'dir' now adds directories to the FRONT of the source search path.
5951 The path starts off empty. Source files that contain debug information
5952 about the directory in which they were compiled can be found even
5953 with an empty path; Sun CC and GCC include this information. If GDB can't
5954 find your source file in the current directory, type "dir .".
5956 * Configuring GDB for compilation
5958 For normal use, type ``./configure host''. See README or gdb.texinfo
5961 GDB now handles cross debugging. If you are remotely debugging between
5962 two different machines, type ``./configure host -target=targ''.
5963 Host is the machine where GDB will run; targ is the machine
5964 where the program that you are debugging will run.