1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.9
8 * GDB now supports hardware watchpoints on x86 GNU Hurd.
12 ** You can now access frame registers from Python scripts.
13 ** New attribute 'producer' for gdb.Symtab objects.
14 ** gdb.Objfile objects have a new attribute "progspace",
15 which is the gdb.Progspace object of the containing program space.
16 ** gdb.Objfile objects have a new attribute "owner".
17 ** gdb.Objfile objects have a new attribute "build_id",
18 which is the build ID generated when the file was built.
19 ** gdb.Objfile objects have a new method "add_separate_debug_file".
20 ** A new event "gdb.clear_objfiles" has been added, triggered when
21 selecting a new file to debug.
22 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
23 ** New function gdb.lookup_objfile.
25 New events which are triggered when GDB modifies the state of the
28 ** gdb.events.inferior_call_pre: Function call is about to be made.
29 ** gdb.events.inferior_call_post: Function call has just been made.
30 ** gdb.events.memory_changed: A memory location has been altered.
31 ** gdb.events.register_changed: A register has been altered.
33 * New Python-based convenience functions:
35 ** $_caller_is(name [, number_of_frames])
36 ** $_caller_matches(regexp [, number_of_frames])
37 ** $_any_caller_is(name [, number_of_frames])
38 ** $_any_caller_matches(regexp [, number_of_frames])
40 * GDB now supports the compilation and injection of source code into
41 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
42 to compile the source code to object code, and if successful, inject
43 and execute that code within the current context of the inferior.
44 Currently the C language is supported. The commands used to
45 interface with this new feature are:
47 compile code [-raw|-r] [--] [source code]
48 compile file [-raw|-r] filename
52 demangle [-l language] [--] name
53 Demangle "name" in the specified language, or the current language
54 if elided. This command is renamed from the "maint demangle" command.
55 The latter is kept as a no-op to avoid "maint demangle" being interpreted
56 as "maint demangler-warning".
58 queue-signal signal-name-or-number
59 Queue a signal to be delivered to the thread when it is resumed.
61 add-auto-load-scripts-directory directory
62 Add entries to the list of directories from which to load auto-loaded
65 maint print user-registers
66 List all currently available "user" registers.
68 compile code [-r|-raw] [--] [source code]
69 Compile, inject, and execute in the inferior the executable object
70 code produced by compiling the provided source code.
72 compile file [-r|-raw] filename
73 Compile and inject into the inferior the executable object code
74 produced by compiling the source code stored in the filename
77 * On resume, GDB now always passes the signal the program had stopped
78 for to the thread the signal was sent to, even if the user changed
79 threads before resuming. Previously GDB would often (but not
80 always) deliver the signal to the thread that happens to be current
83 * Conversely, the "signal" command now consistently delivers the
84 requested signal to the current thread. GDB now asks for
85 confirmation if the program had stopped for a signal and the user
86 switched threads meanwhile.
88 * "breakpoint always-inserted" modes "off" and "auto" merged.
90 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
91 won't remove breakpoints from the target until all threads stop,
92 even in non-stop mode. The "auto" mode has been removed, and "off"
93 is now the default mode.
97 set debug symbol-lookup
98 show debug symbol-lookup
99 Control display of debugging info regarding symbol lookup.
103 ** The -list-thread-groups command outputs an exit-code field for
104 inferiors that have exited.
108 MIPS SDE mips*-sde*-elf*
112 Support for these obsolete configurations has been removed.
114 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
115 SGI Irix-5.x mips-*-irix5*
116 SGI Irix-6.x mips-*-irix6*
117 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
118 VAX running Ultrix vax-*-ultrix*
120 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
121 and "assf"), have been removed. Use the "sharedlibrary" command, or
122 its alias "share", instead.
124 *** Changes in GDB 7.8
126 * New command line options
129 This is an alias for the --data-directory option.
131 * GDB supports printing and modifying of variable length automatic arrays
132 as specified in ISO C99.
134 * The ARM simulator now supports instruction level tracing
135 with or without disassembly.
139 GDB now has support for scripting using Guile. Whether this is
140 available is determined at configure time.
141 Guile version 2.0 or greater is required.
142 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
144 * New commands (for set/show, see "New options" below)
148 Invoke CODE by passing it to the Guile interpreter.
152 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
154 info auto-load guile-scripts [regexp]
155 Print the list of automatically loaded Guile scripts.
157 * The source command is now capable of sourcing Guile scripts.
158 This feature is dependent on the debugger being built with Guile support.
162 set print symbol-loading (off|brief|full)
163 show print symbol-loading
164 Control whether to print informational messages when loading symbol
165 information for a file. The default is "full", but when debugging
166 programs with large numbers of shared libraries the amount of output
169 set guile print-stack (none|message|full)
170 show guile print-stack
171 Show a stack trace when an error is encountered in a Guile script.
173 set auto-load guile-scripts (on|off)
174 show auto-load guile-scripts
175 Control auto-loading of Guile script files.
177 maint ada set ignore-descriptive-types (on|off)
178 maint ada show ignore-descriptive-types
179 Control whether the debugger should ignore descriptive types in Ada
180 programs. The default is not to ignore the descriptive types. See
181 the user manual for more details on descriptive types and the intended
182 usage of this option.
184 set auto-connect-native-target
186 Control whether GDB is allowed to automatically connect to the
187 native target for the run, attach, etc. commands when not connected
188 to any target yet. See also "target native" below.
190 set record btrace replay-memory-access (read-only|read-write)
191 show record btrace replay-memory-access
192 Control what memory accesses are allowed during replay.
194 maint set target-async (on|off)
195 maint show target-async
196 This controls whether GDB targets operate in synchronous or
197 asynchronous mode. Normally the default is asynchronous, if it is
198 available; but this can be changed to more easily debug problems
199 occurring only in synchronous mode.
201 set mi-async (on|off)
203 Control whether MI asynchronous mode is preferred. This supersedes
204 "set target-async" of previous GDB versions.
206 * "set target-async" is deprecated as a CLI option and is now an alias
207 for "set mi-async" (only puts MI into async mode).
209 * Background execution commands (e.g., "c&", "s&", etc.) are now
210 possible ``out of the box'' if the target supports them. Previously
211 the user would need to explicitly enable the possibility with the
212 "set target-async on" command.
214 * New features in the GDB remote stub, GDBserver
216 ** New option --debug-format=option1[,option2,...] allows one to add
217 additional text to each output. At present only timestamps
218 are supported: --debug-format=timestamps.
219 Timestamps can also be turned on with the
220 "monitor set debug-format timestamps" command from GDB.
222 * The 'record instruction-history' command now starts counting instructions
223 at one. This also affects the instruction ranges reported by the
224 'record function-call-history' command when given the /i modifier.
226 * The command 'record function-call-history' supports a new modifier '/c' to
227 indent the function names based on their call stack depth.
228 The fields for the '/i' and '/l' modifier have been reordered.
229 The source line range is now prefixed with 'at'.
230 The instruction range is now prefixed with 'inst'.
231 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
232 "record instruction-history" and "list" commands.
234 * The ranges given as arguments to the 'record function-call-history' and
235 'record instruction-history' commands are now inclusive.
237 * The btrace record target now supports the 'record goto' command.
238 For locations inside the execution trace, the back trace is computed
239 based on the information stored in the execution trace.
241 * The btrace record target supports limited reverse execution and replay.
242 The target does not record data and therefore does not allow reading
245 * The "catch syscall" command now works on s390*-linux* targets.
247 * The "compare-sections" command is no longer specific to target
248 remote. It now works with all targets.
250 * All native targets are now consistently called "native".
251 Consequently, the "target child", "target GNU", "target djgpp",
252 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
253 commands have been replaced with "target native". The QNX/NTO port
254 leaves the "procfs" target in place and adds a "native" target for
255 consistency with other ports. The impact on users should be minimal
256 as these commands previously either throwed an error, or were
257 no-ops. The target's name is visible in the output of the following
258 commands: "help target", "info target", "info files", "maint print
261 * The "target native" command now connects to the native target. This
262 can be used to launch native programs even when "set
263 auto-connect-native-target" is set to off.
265 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.
267 * Support for Intel(R) AVX-512 registers on GNU/Linux.
268 Support displaying and modifying Intel(R) AVX-512 registers
269 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
273 qXfer:btrace:read's annex
274 The qXfer:btrace:read packet supports a new annex 'delta' to read
275 branch trace incrementally.
279 ** Valid Python operations on gdb.Value objects representing
280 structs/classes invoke the corresponding overloaded operators if
282 ** New `Xmethods' feature in the Python API. Xmethods are
283 additional methods or replacements for existing methods of a C++
284 class. This feature is useful for those cases where a method
285 defined in C++ source code could be inlined or optimized out by
286 the compiler, making it unavailable to GDB.
289 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
291 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
292 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
293 its alias "share", instead.
295 * The commands "set remotebaud" and "show remotebaud" are no longer
296 supported. Use "set serial baud" and "show serial baud" (respectively)
301 ** A new option "-gdb-set mi-async" replaces "-gdb-set
302 target-async". The latter is left as a deprecated alias of the
303 former for backward compatibility. If the target supports it,
304 CLI background execution commands are now always possible by
305 default, independently of whether the frontend stated a
306 preference for asynchronous execution with "-gdb-set mi-async".
307 Previously "-gdb-set target-async off" affected both MI execution
308 commands and CLI execution commands.
310 *** Changes in GDB 7.7
312 * Improved support for process record-replay and reverse debugging on
313 arm*-linux* targets. Support for thumb32 and syscall instruction
314 recording has been added.
316 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
318 * GDB now supports Fission DWP file format version 2.
319 http://gcc.gnu.org/wiki/DebugFission
321 * New convenience function "$_isvoid", to check whether an expression
322 is void. A void expression is an expression where the type of the
323 result is "void". For example, some convenience variables may be
324 "void" when evaluated (e.g., "$_exitcode" before the execution of
325 the program being debugged; or an undefined convenience variable).
326 Another example, when calling a function whose return type is
329 * The "maintenance print objfiles" command now takes an optional regexp.
331 * The "catch syscall" command now works on arm*-linux* targets.
333 * GDB now consistently shows "<not saved>" when printing values of
334 registers the debug info indicates have not been saved in the frame
335 and there's nowhere to retrieve them from
336 (callee-saved/call-clobbered registers):
341 (gdb) info registers rax
344 Before, the former would print "<optimized out>", and the latter
345 "*value not available*".
347 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
352 ** Frame filters and frame decorators have been added.
353 ** Temporary breakpoints are now supported.
354 ** Line tables representation has been added.
355 ** New attribute 'parent_type' for gdb.Field objects.
356 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
357 ** New attribute 'name' for gdb.Type objects.
361 Nios II ELF nios2*-*-elf
362 Nios II GNU/Linux nios2*-*-linux
363 Texas Instruments MSP430 msp430*-*-elf
365 * Removed native configurations
367 Support for these a.out NetBSD and OpenBSD obsolete configurations has
368 been removed. ELF variants of these configurations are kept supported.
370 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
371 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
372 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
373 i[34567]86-*-openbsd3.[0-3]
374 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
375 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
376 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
380 Like "catch throw", but catches a re-thrown exception.
382 Renamed from old "maint check-symtabs".
384 Perform consistency checks on symtabs.
386 Expand symtabs matching an optional regexp.
389 Display the details of GDB configure-time options.
391 maint set|show per-command
392 maint set|show per-command space
393 maint set|show per-command time
394 maint set|show per-command symtab
395 Enable display of per-command gdb resource usage.
397 remove-symbol-file FILENAME
398 remove-symbol-file -a ADDRESS
399 Remove a symbol file added via add-symbol-file. The file to remove
400 can be identified by its filename or by an address that lies within
401 the boundaries of this symbol file in memory.
404 info exceptions REGEXP
405 Display the list of Ada exceptions defined in the program being
406 debugged. If provided, only the exceptions whose names match REGEXP
411 set debug symfile off|on
413 Control display of debugging info regarding reading symbol files and
414 symbol tables within those files
416 set print raw frame-arguments
417 show print raw frame-arguments
418 Set/show whether to print frame arguments in raw mode,
419 disregarding any defined pretty-printers.
421 set remote trace-status-packet
422 show remote trace-status-packet
423 Set/show the use of remote protocol qTStatus packet.
427 Control display of debugging messages related to Nios II targets.
431 Control whether target-assisted range stepping is enabled.
433 set startup-with-shell
434 show startup-with-shell
435 Specifies whether Unix child processes are started via a shell or
440 Use the target memory cache for accesses to the code segment. This
441 improves performance of remote debugging (particularly disassembly).
443 * You can now use a literal value 'unlimited' for options that
444 interpret 0 or -1 as meaning "unlimited". E.g., "set
445 trace-buffer-size unlimited" is now an alias for "set
446 trace-buffer-size -1" and "set height unlimited" is now an alias for
449 * The "set debug symtab-create" debugging option of GDB has been changed to
450 accept a verbosity level. 0 means "off", 1 provides basic debugging
451 output, and values of 2 or greater provides more verbose output.
453 * New command-line options
455 Display the details of GDB configure-time options.
457 * The command 'tsave' can now support new option '-ctf' to save trace
458 buffer in Common Trace Format.
460 * Newly installed $prefix/bin/gcore acts as a shell interface for the
463 * GDB now implements the the C++ 'typeid' operator.
465 * The new convenience variable $_exception holds the exception being
466 thrown or caught at an exception-related catchpoint.
468 * The exception-related catchpoints, like "catch throw", now accept a
469 regular expression which can be used to filter exceptions by type.
471 * The new convenience variable $_exitsignal is automatically set to
472 the terminating signal number when the program being debugged dies
473 due to an uncaught signal.
477 ** All MI commands now accept an optional "--language" option.
478 Support for this feature can be verified by using the "-list-features"
479 command, which should contain "language-option".
481 ** The new command -info-gdb-mi-command allows the user to determine
482 whether a GDB/MI command is supported or not.
484 ** The "^error" result record returned when trying to execute an undefined
485 GDB/MI command now provides a variable named "code" whose content is the
486 "undefined-command" error code. Support for this feature can be verified
487 by using the "-list-features" command, which should contain
488 "undefined-command-error-code".
490 ** The -trace-save MI command can optionally save trace buffer in Common
493 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
495 ** The command -data-list-register-values now accepts an optional
496 "--skip-unavailable" option. When used, only the available registers
499 ** The new command -trace-frame-collected dumps collected variables,
500 computed expressions, tvars, memory and registers in a traceframe.
502 ** The commands -stack-list-locals, -stack-list-arguments and
503 -stack-list-variables now accept an option "--skip-unavailable".
504 When used, only the available locals or arguments are displayed.
506 ** The -exec-run command now accepts an optional "--start" option.
507 When used, the command follows the same semantics as the "start"
508 command, stopping the program's execution at the start of its
509 main subprogram. Support for this feature can be verified using
510 the "-list-features" command, which should contain
511 "exec-run-start-option".
513 ** The new commands -catch-assert and -catch-exceptions insert
514 catchpoints stopping the program when Ada exceptions are raised.
516 ** The new command -info-ada-exceptions provides the equivalent of
517 the new "info exceptions" command.
519 * New system-wide configuration scripts
520 A GDB installation now provides scripts suitable for use as system-wide
521 configuration scripts for the following systems:
525 * GDB now supports target-assigned range stepping with remote targets.
526 This improves the performance of stepping source lines by reducing
527 the number of control packets from/to GDB. See "New remote packets"
530 * GDB now understands the element 'tvar' in the XML traceframe info.
531 It has the id of the collected trace state variables.
533 * On S/390 targets that provide the transactional-execution feature,
534 the program interruption transaction diagnostic block (TDB) is now
535 represented as a number of additional "registers" in GDB.
541 The vCont packet supports a new 'r' action, that tells the remote
542 stub to step through an address range itself, without GDB
543 involvemement at each single-step.
545 qXfer:libraries-svr4:read's annex
546 The previously unused annex of the qXfer:libraries-svr4:read packet
547 is now used to support passing an argument list. The remote stub
548 reports support for this argument list to GDB's qSupported query.
549 The defined arguments are "start" and "prev", used to reduce work
550 necessary for library list updating, resulting in significant
553 * New features in the GDB remote stub, GDBserver
555 ** GDBserver now supports target-assisted range stepping. Currently
556 enabled on x86/x86_64 GNU/Linux targets.
558 ** GDBserver now adds element 'tvar' in the XML in the reply to
559 'qXfer:traceframe-info:read'. It has the id of the collected
560 trace state variables.
562 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
565 * New 'z' formatter for printing and examining memory, this displays the
566 value as hexadecimal zero padded on the left to the size of the type.
568 * GDB can now use Windows x64 unwinding data.
570 * The "set remotebaud" command has been replaced by "set serial baud".
571 Similarly, "show remotebaud" has been replaced by "show serial baud".
572 The "set remotebaud" and "show remotebaud" commands are still available
573 to provide backward compatibility with older versions of GDB.
575 *** Changes in GDB 7.6
577 * Target record has been renamed to record-full.
578 Record/replay is now enabled with the "record full" command.
579 This also affects settings that are associated with full record/replay
580 that have been moved from "set/show record" to "set/show record full":
582 set|show record full insn-number-max
583 set|show record full stop-at-limit
584 set|show record full memory-query
586 * A new record target "record-btrace" has been added. The new target
587 uses hardware support to record the control-flow of a process. It
588 does not support replaying the execution, but it implements the
589 below new commands for investigating the recorded execution log.
590 This new recording method can be enabled using:
594 The "record-btrace" target is only available on Intel Atom processors
595 and requires a Linux kernel 2.6.32 or later.
597 * Two new commands have been added for record/replay to give information
598 about the recorded execution without having to replay the execution.
599 The commands are only supported by "record btrace".
601 record instruction-history prints the execution history at
602 instruction granularity
604 record function-call-history prints the execution history at
607 * New native configurations
609 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
610 FreeBSD/powerpc powerpc*-*-freebsd
611 x86_64/Cygwin x86_64-*-cygwin*
612 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
616 ARM AArch64 aarch64*-*-elf
617 ARM AArch64 GNU/Linux aarch64*-*-linux
618 Lynx 178 PowerPC powerpc-*-lynx*178
619 x86_64/Cygwin x86_64-*-cygwin*
620 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
622 * If the configured location of system.gdbinit file (as given by the
623 --with-system-gdbinit option at configure time) is in the
624 data-directory (as specified by --with-gdb-datadir at configure
625 time) or in one of its subdirectories, then GDB will look for the
626 system-wide init file in the directory specified by the
627 --data-directory command-line option.
629 * New command line options:
631 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
632 other initialization files, unlike -nx which disables all of them.
634 * Removed command line options
636 -epoch This was used by the gdb mode in Epoch, an ancient fork of
639 * The 'ptype' and 'whatis' commands now accept an argument to control
642 * 'info proc' now works on some core files.
646 ** Vectors can be created with gdb.Type.vector.
648 ** Python's atexit.register now works in GDB.
650 ** Types can be pretty-printed via a Python API.
652 ** Python 3 is now supported (in addition to Python 2.4 or later)
654 ** New class gdb.Architecture exposes GDB's internal representation
655 of architecture in the Python API.
657 ** New method Frame.architecture returns the gdb.Architecture object
658 corresponding to the frame's architecture.
660 * New Python-based convenience functions:
662 ** $_memeq(buf1, buf2, length)
663 ** $_streq(str1, str2)
665 ** $_regex(str, regex)
667 * The 'cd' command now defaults to using '~' (the home directory) if not
670 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
671 default for GCC since November 2000.
673 * The command 'forward-search' can now be abbreviated as 'fo'.
675 * The command 'info tracepoints' can now display 'installed on target'
676 or 'not installed on target' for each non-pending location of tracepoint.
678 * New configure options
680 --enable-libmcheck/--disable-libmcheck
681 By default, development versions are built with -lmcheck on hosts
682 that support it, in order to help track memory corruption issues.
683 Release versions, on the other hand, are built without -lmcheck
684 by default. The --enable-libmcheck/--disable-libmcheck configure
685 options allow the user to override that default.
686 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
687 This configure option allows the user to build GDB with
688 libbabeltrace using which GDB can read Common Trace Format data.
690 * New commands (for set/show, see "New options" below)
693 Catch signals. This is similar to "handle", but allows commands and
694 conditions to be attached.
697 List the BFDs known to GDB.
699 python-interactive [command]
701 Start a Python interactive prompt, or evaluate the optional command
702 and print the result of expressions.
705 "py" is a new alias for "python".
707 enable type-printer [name]...
708 disable type-printer [name]...
709 Enable or disable type printers.
713 ** For the Renesas Super-H architecture, the "regs" command has been removed
714 (has been deprecated in GDB 7.5), and "info all-registers" should be used
719 set print type methods (on|off)
720 show print type methods
721 Control whether method declarations are displayed by "ptype".
722 The default is to show them.
724 set print type typedefs (on|off)
725 show print type typedefs
726 Control whether typedef definitions are displayed by "ptype".
727 The default is to show them.
729 set filename-display basename|relative|absolute
730 show filename-display
731 Control the way in which filenames is displayed.
732 The default is "relative", which preserves previous behavior.
734 set trace-buffer-size
735 show trace-buffer-size
736 Request target to change the size of trace buffer.
738 set remote trace-buffer-size-packet auto|on|off
739 show remote trace-buffer-size-packet
740 Control the use of the remote protocol `QTBuffer:size' packet.
744 Control display of debugging messages related to ARM AArch64.
747 set debug coff-pe-read
748 show debug coff-pe-read
749 Control display of debugging messages related to reading of COFF/PE
754 Control display of debugging messages related to Mach-O symbols
757 set debug notification
758 show debug notification
759 Control display of debugging info for async remote notification.
763 ** Command parameter changes are now notified using new async record
764 "=cmd-param-changed".
765 ** Trace frame changes caused by command "tfind" are now notified using
766 new async record "=traceframe-changed".
767 ** The creation, deletion and modification of trace state variables
768 are now notified using new async records "=tsv-created",
769 "=tsv-deleted" and "=tsv-modified".
770 ** The start and stop of process record are now notified using new
771 async record "=record-started" and "=record-stopped".
772 ** Memory changes are now notified using new async record
774 ** The data-disassemble command response will include a "fullname" field
775 containing the absolute file name when source has been requested.
776 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
777 command, to allow pattern filling of memory areas.
778 ** New commands "-catch-load"/"-catch-unload" added for intercepting
779 library load/unload events.
780 ** The response to breakpoint commands and breakpoint async records
781 includes an "installed" field containing a boolean state about each
782 non-pending tracepoint location is whether installed on target or not.
783 ** Output of the "-trace-status" command includes a "trace-file" field
784 containing the name of the trace file being examined. This field is
785 optional, and only present when examining a trace file.
786 ** The "fullname" field is now always present along with the "file" field,
787 even if the file cannot be found by GDB.
789 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
790 You must have the LZMA library available when configuring GDB for this
791 feature to be enabled. For more information, see:
792 http://fedoraproject.org/wiki/Features/MiniDebugInfo
797 Set the size of trace buffer. The remote stub reports support for this
798 packet to gdb's qSupported query.
801 Enable Branch Trace Store (BTS)-based branch tracing for the current
802 thread. The remote stub reports support for this packet to gdb's
806 Disable branch tracing for the current thread. The remote stub reports
807 support for this packet to gdb's qSupported query.
810 Read the traced branches for the current thread. The remote stub
811 reports support for this packet to gdb's qSupported query.
813 *** Changes in GDB 7.5
815 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
816 for more x32 ABI info.
818 * GDB now supports access to MIPS DSP registers on Linux targets.
820 * GDB now supports debugging microMIPS binaries.
822 * The "info os" command on GNU/Linux can now display information on
823 several new classes of objects managed by the operating system:
824 "info os procgroups" lists process groups
825 "info os files" lists file descriptors
826 "info os sockets" lists internet-domain sockets
827 "info os shm" lists shared-memory regions
828 "info os semaphores" lists semaphores
829 "info os msg" lists message queues
830 "info os modules" lists loaded kernel modules
832 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
833 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
834 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
835 options and inspect the probe arguments using the new $_probe_arg family
836 of convenience variables. You can obtain more information about SystemTap
837 in <http://sourceware.org/systemtap/>.
839 * GDB now supports reversible debugging on ARM, it allows you to
840 debug basic ARM and THUMB instructions, and provides
841 record/replay support.
843 * The option "symbol-reloading" has been deleted as it is no longer used.
847 ** GDB commands implemented in Python can now be put in command class
850 ** The "maint set python print-stack on|off" is now deleted.
852 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
853 apply "flag enum"-style pretty-printing to any enum.
855 ** gdb.lookup_symbol can now work when there is no current frame.
857 ** gdb.Symbol now has a 'line' attribute, holding the line number in
858 the source at which the symbol was defined.
860 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
861 method 'value'. The former indicates whether the symbol needs a
862 frame in order to compute its value, and the latter computes the
865 ** A new method 'referenced_value' on gdb.Value objects which can
866 dereference pointer as well as C++ reference values.
868 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
869 which return the global and static blocks (as gdb.Block objects),
870 of the underlying symbol table, respectively.
872 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
873 object associated with a PC value.
875 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
876 of the address range occupied by code for the current source line.
878 * Go language support.
879 GDB now supports debugging programs written in the Go programming
882 * GDBserver now supports stdio connections.
883 E.g. (gdb) target remote | ssh myhost gdbserver - hello
885 * The binary "gdbtui" can no longer be built or installed.
886 Use "gdb -tui" instead.
888 * GDB will now print "flag" enums specially. A flag enum is one where
889 all the enumerator values have no bits in common when pairwise
890 "and"ed. When printing a value whose type is a flag enum, GDB will
891 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
892 (gdb) print (enum E) 3
895 * The filename part of a linespec will now match trailing components
896 of a source file name. For example, "break gcc/expr.c:1000" will
897 now set a breakpoint in build/gcc/expr.c, but not
900 * The "info proc" and "generate-core-file" commands will now also
901 work on remote targets connected to GDBserver on Linux.
903 * The command "info catch" has been removed. It has been disabled
906 * The "catch exception" and "catch assert" commands now accept
907 a condition at the end of the command, much like the "break"
908 command does. For instance:
910 (gdb) catch exception Constraint_Error if Barrier = True
912 Previously, it was possible to add a condition to such catchpoints,
913 but it had to be done as a second step, after the catchpoint had been
914 created, using the "condition" command.
916 * The "info static-tracepoint-marker" command will now also work on
917 native Linux targets with in-process agent.
919 * GDB can now set breakpoints on inlined functions.
921 * The .gdb_index section has been updated to include symbols for
922 inlined functions. GDB will ignore older .gdb_index sections by
923 default, which could cause symbol files to be loaded more slowly
924 until their .gdb_index sections can be recreated. The new command
925 "set use-deprecated-index-sections on" will cause GDB to use any older
926 .gdb_index sections it finds. This will restore performance, but the
927 ability to set breakpoints on inlined functions will be lost in symbol
928 files with older .gdb_index sections.
930 The .gdb_index section has also been updated to record more information
931 about each symbol. This speeds up the "info variables", "info functions"
932 and "info types" commands when used with programs having the .gdb_index
933 section, as well as speeding up debugging with shared libraries using
934 the .gdb_index section.
936 * Ada support for GDB/MI Variable Objects has been added.
938 * GDB can now support 'breakpoint always-inserted mode' in 'record'
943 ** New command -info-os is the MI equivalent of "info os".
945 ** Output logs ("set logging" and related) now include MI output.
949 ** "set use-deprecated-index-sections on|off"
950 "show use-deprecated-index-sections on|off"
951 Controls the use of deprecated .gdb_index sections.
953 ** "catch load" and "catch unload" can be used to stop when a shared
954 library is loaded or unloaded, respectively.
956 ** "enable count" can be used to auto-disable a breakpoint after
959 ** "info vtbl" can be used to show the virtual method tables for
960 C++ and Java objects.
962 ** "explore" and its sub commands "explore value" and "explore type"
963 can be used to recursively explore values and types of
964 expressions. These commands are available only if GDB is
965 configured with '--with-python'.
967 ** "info auto-load" shows status of all kinds of auto-loaded files,
968 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
969 sequences of commands files, "info auto-load python-scripts"
970 shows status of auto-loading Python script files,
971 "info auto-load local-gdbinit" shows status of loading init file
972 (.gdbinit) from current directory and "info auto-load libthread-db" shows
973 status of inferior specific thread debugging shared library loading.
975 ** "info auto-load-scripts", "set auto-load-scripts on|off"
976 and "show auto-load-scripts" commands have been deprecated, use their
977 "info auto-load python-scripts", "set auto-load python-scripts on|off"
978 and "show auto-load python-scripts" counterparts instead.
980 ** "dprintf location,format,args..." creates a dynamic printf, which
981 is basically a breakpoint that does a printf and immediately
982 resumes your program's execution, so it is like a printf that you
983 can insert dynamically at runtime instead of at compiletime.
985 ** "set print symbol"
987 Controls whether GDB attempts to display the symbol, if any,
988 corresponding to addresses it prints. This defaults to "on", but
989 you can set it to "off" to restore GDB's previous behavior.
991 * Deprecated commands
993 ** For the Renesas Super-H architecture, the "regs" command has been
994 deprecated, and "info all-registers" should be used instead.
998 Renesas RL78 rl78-*-elf
999 HP OpenVMS ia64 ia64-hp-openvms*
1001 * GDBserver supports evaluation of breakpoint conditions. When
1002 support is advertised by GDBserver, GDB may be told to send the
1003 breakpoint conditions in bytecode form to GDBserver. GDBserver
1004 will only report the breakpoint trigger to GDB when its condition
1009 set mips compression
1010 show mips compression
1011 Select the compressed ISA encoding used in functions that have no symbol
1012 information available. The encoding can be set to either of:
1015 and is updated automatically from ELF file flags if available.
1017 set breakpoint condition-evaluation
1018 show breakpoint condition-evaluation
1019 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1020 GDBserver ("target"). Default option "auto" chooses the most efficient
1022 This option can improve debugger efficiency depending on the speed of the
1026 Disable auto-loading globally.
1029 Show auto-loading setting of all kinds of auto-loaded files.
1031 set auto-load gdb-scripts on|off
1032 show auto-load gdb-scripts
1033 Control auto-loading of GDB canned sequences of commands files.
1035 set auto-load python-scripts on|off
1036 show auto-load python-scripts
1037 Control auto-loading of Python script files.
1039 set auto-load local-gdbinit on|off
1040 show auto-load local-gdbinit
1041 Control loading of init file (.gdbinit) from current directory.
1043 set auto-load libthread-db on|off
1044 show auto-load libthread-db
1045 Control auto-loading of inferior specific thread debugging shared library.
1047 set auto-load scripts-directory <dir1>[:<dir2>...]
1048 show auto-load scripts-directory
1049 Set a list of directories from which to load auto-loaded scripts.
1050 Automatically loaded Python scripts and GDB scripts are located in one
1051 of the directories listed by this option.
1052 The delimiter (':' above) may differ according to the host platform.
1054 set auto-load safe-path <dir1>[:<dir2>...]
1055 show auto-load safe-path
1056 Set a list of directories from which it is safe to auto-load files.
1057 The delimiter (':' above) may differ according to the host platform.
1059 set debug auto-load on|off
1060 show debug auto-load
1061 Control display of debugging info for auto-loading the files above.
1063 set dprintf-style gdb|call|agent
1065 Control the way in which a dynamic printf is performed; "gdb"
1066 requests a GDB printf command, while "call" causes dprintf to call a
1067 function in the inferior. "agent" requests that the target agent
1068 (such as GDBserver) do the printing.
1070 set dprintf-function <expr>
1071 show dprintf-function
1072 set dprintf-channel <expr>
1073 show dprintf-channel
1074 Set the function and optional first argument to the call when using
1075 the "call" style of dynamic printf.
1077 set disconnected-dprintf on|off
1078 show disconnected-dprintf
1079 Control whether agent-style dynamic printfs continue to be in effect
1080 after GDB disconnects.
1082 * New configure options
1084 --with-auto-load-dir
1085 Configure default value for the 'set auto-load scripts-directory'
1086 setting above. It defaults to '$debugdir:$datadir/auto-load',
1087 $debugdir representing global debugging info directories (available
1088 via 'show debug-file-directory') and $datadir representing GDB's data
1089 directory (available via 'show data-directory').
1091 --with-auto-load-safe-path
1092 Configure default value for the 'set auto-load safe-path' setting
1093 above. It defaults to the --with-auto-load-dir setting.
1095 --without-auto-load-safe-path
1096 Set 'set auto-load safe-path' to '/', effectively disabling this
1099 * New remote packets
1101 z0/z1 conditional breakpoints extension
1103 The z0/z1 breakpoint insertion packets have been extended to carry
1104 a list of conditional expressions over to the remote stub depending on the
1105 condition evaluation mode. The use of this extension can be controlled
1106 via the "set remote conditional-breakpoints-packet" command.
1110 Specify the signals which the remote stub may pass to the debugged
1111 program without GDB involvement.
1113 * New command line options
1115 --init-command=FILE, -ix Like --command, -x but execute it
1116 before loading inferior.
1117 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1118 execute it before loading inferior.
1120 *** Changes in GDB 7.4
1122 * GDB now handles ambiguous linespecs more consistently; the existing
1123 FILE:LINE support has been expanded to other types of linespecs. A
1124 breakpoint will now be set on all matching locations in all
1125 inferiors, and locations will be added or removed according to
1128 * GDB now allows you to skip uninteresting functions and files when
1129 stepping with the "skip function" and "skip file" commands.
1131 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1132 and "show remote hardware-watchpoint-length-limit". These allows to
1133 set or show the maximum length limit (in bytes) of a remote
1134 target hardware watchpoint.
1136 This allows e.g. to use "unlimited" hardware watchpoints with the
1137 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1138 watchpoints are slower than real hardware watchpoints but are
1139 significantly faster than gdb software watchpoints.
1143 ** The register_pretty_printer function in module gdb.printing now takes
1144 an optional `replace' argument. If True, the new printer replaces any
1147 ** The "maint set python print-stack on|off" command has been
1148 deprecated and will be deleted in GDB 7.5.
1149 A new command: "set python print-stack none|full|message" has
1150 replaced it. Additionally, the default for "print-stack" is
1151 now "message", which just prints the error message without
1154 ** A prompt substitution hook (prompt_hook) is now available to the
1157 ** A new Python module, gdb.prompt has been added to the GDB Python
1158 modules library. This module provides functionality for
1159 escape sequences in prompts (used by set/show
1160 extended-prompt). These escape sequences are replaced by their
1161 corresponding value.
1163 ** Python commands and convenience-functions located in
1164 'data-directory'/python/gdb/command and
1165 'data-directory'/python/gdb/function are now automatically loaded
1168 ** Blocks now provide four new attributes. global_block and
1169 static_block will return the global and static blocks
1170 respectively. is_static and is_global are boolean attributes
1171 that indicate if the block is one of those two types.
1173 ** Symbols now provide the "type" attribute, the type of the symbol.
1175 ** The "gdb.breakpoint" function has been deprecated in favor of
1178 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1179 of a function. This class is based on the "finish" command
1180 available in the CLI.
1182 ** Type objects for struct and union types now allow access to
1183 the fields using standard Python dictionary (mapping) methods.
1184 For example, "some_type['myfield']" now works, as does
1185 "some_type.items()".
1187 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1190 ** A new function, "deep_items" has been added to the gdb.types
1191 module in the GDB Python modules library. This function returns
1192 an iterator over the fields of a struct or union type. Unlike
1193 the standard Python "iteritems" method, it will recursively traverse
1194 any anonymous fields.
1198 ** "*stopped" events can report several new "reason"s, such as
1201 ** Breakpoint changes are now notified using new async records, like
1202 "=breakpoint-modified".
1204 ** New command -ada-task-info.
1206 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1207 $sdir specifies the default system locations of shared libraries.
1208 $pdir specifies the directory where the libpthread used by the application
1211 GDB no longer looks in $sdir and $pdir after it has searched the directories
1212 mentioned in libthread-db-search-path. If you want to search those
1213 directories, they must be specified in libthread-db-search-path.
1214 The default value of libthread-db-search-path on GNU/Linux and Solaris
1215 systems is now "$sdir:$pdir".
1217 $pdir is not supported by gdbserver, it is currently ignored.
1218 $sdir is supported by gdbserver.
1220 * New configure option --with-iconv-bin.
1221 When using the internationalization support like the one in the GNU C
1222 library, GDB will invoke the "iconv" program to get a list of supported
1223 character sets. If this program lives in a non-standard location, one can
1224 use this option to specify where to find it.
1226 * When natively debugging programs on PowerPC BookE processors running
1227 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1228 watchpoints, which specify a mask in addition to an address to watch.
1229 The mask specifies that some bits of an address (the bits which are
1230 reset in the mask) should be ignored when matching the address accessed
1231 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1232 section in the user manual for more details.
1234 * The new option --once causes GDBserver to stop listening for connections once
1235 the first connection is made. The listening port used by GDBserver will
1236 become available after that.
1238 * New commands "info macros" and "alias" have been added.
1240 * New function parameters suffix @entry specifies value of function parameter
1241 at the time the function got called. Entry values are available only since
1247 "!" is now an alias of the "shell" command.
1248 Note that no space is needed between "!" and SHELL COMMAND.
1252 watch EXPRESSION mask MASK_VALUE
1253 The watch command now supports the mask argument which allows creation
1254 of masked watchpoints, if the current architecture supports this feature.
1256 info auto-load-scripts [REGEXP]
1257 This command was formerly named "maintenance print section-scripts".
1258 It is now generally useful and is no longer a maintenance-only command.
1260 info macro [-all] [--] MACRO
1261 The info macro command has new options `-all' and `--'. The first for
1262 printing all definitions of a macro. The second for explicitly specifying
1263 the end of arguments and the beginning of the macro name in case the macro
1264 name starts with a hyphen.
1266 collect[/s] EXPRESSIONS
1267 The tracepoint collect command now takes an optional modifier "/s"
1268 that directs it to dereference pointer-to-character types and
1269 collect the bytes of memory up to a zero byte. The behavior is
1270 similar to what you see when you use the regular print command on a
1271 string. An optional integer following the "/s" sets a bound on the
1272 number of bytes that will be collected.
1275 The trace start command now interprets any supplied arguments as a
1276 note to be recorded with the trace run, with an effect similar to
1277 setting the variable trace-notes.
1280 The trace stop command now interprets any arguments as a note to be
1281 mentioned along with the tstatus report that the trace was stopped
1282 with a command. The effect is similar to setting the variable
1285 * Tracepoints can now be enabled and disabled at any time after a trace
1286 experiment has been started using the standard "enable" and "disable"
1287 commands. It is now possible to start a trace experiment with no enabled
1288 tracepoints; GDB will display a warning, but will allow the experiment to
1289 begin, assuming that tracepoints will be enabled as needed while the trace
1292 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1293 locations with 4-byte instructions, when they were previously
1294 limited to locations with instructions of 5 bytes or longer.
1298 set debug dwarf2-read
1299 show debug dwarf2-read
1300 Turns on or off display of debugging messages related to reading
1301 DWARF debug info. The default is off.
1303 set debug symtab-create
1304 show debug symtab-create
1305 Turns on or off display of debugging messages related to symbol table
1306 creation. The default is off.
1309 show extended-prompt
1310 Set the GDB prompt, and allow escape sequences to be inserted to
1311 display miscellaneous information (see 'help set extended-prompt'
1312 for the list of sequences). This prompt (and any information
1313 accessed through the escape sequences) is updated every time the
1314 prompt is displayed.
1316 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1317 show print entry-values
1318 Set printing of frame argument values at function entry. In some cases
1319 GDB can determine the value of function argument which was passed by the
1320 function caller, even if the value was modified inside the called function.
1322 set debug entry-values
1323 show debug entry-values
1324 Control display of debugging info for determining frame argument values at
1325 function entry and virtual tail call frames.
1327 set basenames-may-differ
1328 show basenames-may-differ
1329 Set whether a source file may have multiple base names.
1330 (A "base name" is the name of a file with the directory part removed.
1331 Example: The base name of "/home/user/hello.c" is "hello.c".)
1332 If set, GDB will canonicalize file names (e.g., expand symlinks)
1333 before comparing them. Canonicalization is an expensive operation,
1334 but it allows the same file be known by more than one base name.
1335 If not set (the default), all source files are assumed to have just
1336 one base name, and gdb will do file name comparisons more efficiently.
1342 Set a user name and notes for the current and any future trace runs.
1343 This is useful for long-running and/or disconnected traces, to
1344 inform others (or yourself) as to who is running the trace, supply
1345 contact information, or otherwise explain what is going on.
1347 set trace-stop-notes
1348 show trace-stop-notes
1349 Set a note attached to the trace run, that is displayed when the
1350 trace has been stopped by a tstop command. This is useful for
1351 instance as an explanation, if you are stopping a trace run that was
1352 started by someone else.
1354 * New remote packets
1358 Dynamically enable a tracepoint in a started trace experiment.
1362 Dynamically disable a tracepoint in a started trace experiment.
1366 Set the user and notes of the trace run.
1370 Query the current status of a tracepoint.
1374 Query the minimum length of instruction at which a fast tracepoint may
1377 * Dcache size (number of lines) and line-size are now runtime-configurable
1378 via "set dcache line" and "set dcache line-size" commands.
1382 Texas Instruments TMS320C6x tic6x-*-*
1386 Renesas RL78 rl78-*-elf
1388 *** Changes in GDB 7.3.1
1390 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1392 *** Changes in GDB 7.3
1394 * GDB has a new command: "thread find [REGEXP]".
1395 It finds the thread id whose name, target id, or thread extra info
1396 matches the given regular expression.
1398 * The "catch syscall" command now works on mips*-linux* targets.
1400 * The -data-disassemble MI command now supports modes 2 and 3 for
1401 dumping the instruction opcodes.
1403 * New command line options
1405 -data-directory DIR Specify DIR as the "data-directory".
1406 This is mostly for testing purposes.
1408 * The "maint set python auto-load on|off" command has been renamed to
1409 "set auto-load-scripts on|off".
1411 * GDB has a new command: "set directories".
1412 It is like the "dir" command except that it replaces the
1413 source path list instead of augmenting it.
1415 * GDB now understands thread names.
1417 On GNU/Linux, "info threads" will display the thread name as set by
1418 prctl or pthread_setname_np.
1420 There is also a new command, "thread name", which can be used to
1421 assign a name internally for GDB to display.
1424 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1425 has been integrated into GDB.
1429 ** The function gdb.Write now accepts an optional keyword 'stream'.
1430 This keyword, when provided, will direct the output to either
1431 stdout, stderr, or GDB's logging output.
1433 ** Parameters can now be be sub-classed in Python, and in particular
1434 you may implement the get_set_doc and get_show_doc functions.
1435 This improves how Parameter set/show documentation is processed
1436 and allows for more dynamic content.
1438 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1439 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1440 have an is_valid method.
1442 ** Breakpoints can now be sub-classed in Python, and in particular
1443 you may implement a 'stop' function that is executed each time
1444 the inferior reaches that breakpoint.
1446 ** New function gdb.lookup_global_symbol looks up a global symbol.
1448 ** GDB values in Python are now callable if the value represents a
1449 function. For example, if 'some_value' represents a function that
1450 takes two integer parameters and returns a value, you can call
1451 that function like so:
1453 result = some_value (10,20)
1455 ** Module gdb.types has been added.
1456 It contains a collection of utilities for working with gdb.Types objects:
1457 get_basic_type, has_field, make_enum_dict.
1459 ** Module gdb.printing has been added.
1460 It contains utilities for writing and registering pretty-printers.
1461 New classes: PrettyPrinter, SubPrettyPrinter,
1462 RegexpCollectionPrettyPrinter.
1463 New function: register_pretty_printer.
1465 ** New commands "info pretty-printers", "enable pretty-printer" and
1466 "disable pretty-printer" have been added.
1468 ** gdb.parameter("directories") is now available.
1470 ** New function gdb.newest_frame returns the newest frame in the
1473 ** The gdb.InferiorThread class has a new "name" attribute. This
1474 holds the thread's name.
1476 ** Python Support for Inferior events.
1477 Python scripts can add observers to be notified of events
1478 occurring in the process being debugged.
1479 The following events are currently supported:
1480 - gdb.events.cont Continue event.
1481 - gdb.events.exited Inferior exited event.
1482 - gdb.events.stop Signal received, and Breakpoint hit events.
1486 ** GDB now puts template parameters in scope when debugging in an
1487 instantiation. For example, if you have:
1489 template<int X> int func (void) { return X; }
1491 then if you step into func<5>, "print X" will show "5". This
1492 feature requires proper debuginfo support from the compiler; it
1493 was added to GCC 4.5.
1495 ** The motion commands "next", "finish", "until", and "advance" now
1496 work better when exceptions are thrown. In particular, GDB will
1497 no longer lose control of the inferior; instead, the GDB will
1498 stop the inferior at the point at which the exception is caught.
1499 This functionality requires a change in the exception handling
1500 code that was introduced in GCC 4.5.
1502 * GDB now follows GCC's rules on accessing volatile objects when
1503 reading or writing target state during expression evaluation.
1504 One notable difference to prior behavior is that "print x = 0"
1505 no longer generates a read of x; the value of the assignment is
1506 now always taken directly from the value being assigned.
1508 * GDB now has some support for using labels in the program's source in
1509 linespecs. For instance, you can use "advance label" to continue
1510 execution to a label.
1512 * GDB now has support for reading and writing a new .gdb_index
1513 section. This section holds a fast index of DWARF debugging
1514 information and can be used to greatly speed up GDB startup and
1515 operation. See the documentation for `save gdb-index' for details.
1517 * The "watch" command now accepts an optional "-location" argument.
1518 When used, this causes GDB to watch the memory referred to by the
1519 expression. Such a watchpoint is never deleted due to it going out
1522 * GDB now supports thread debugging of core dumps on GNU/Linux.
1524 GDB now activates thread debugging using the libthread_db library
1525 when debugging GNU/Linux core dumps, similarly to when debugging
1526 live processes. As a result, when debugging a core dump file, GDB
1527 is now able to display pthread_t ids of threads. For example, "info
1528 threads" shows the same output as when debugging the process when it
1529 was live. In earlier releases, you'd see something like this:
1532 * 1 LWP 6780 main () at main.c:10
1534 While now you see this:
1537 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1539 It is also now possible to inspect TLS variables when debugging core
1542 When debugging a core dump generated on a machine other than the one
1543 used to run GDB, you may need to point GDB at the correct
1544 libthread_db library with the "set libthread-db-search-path"
1545 command. See the user manual for more details on this command.
1547 * When natively debugging programs on PowerPC BookE processors running
1548 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1549 which stop execution of the inferior whenever it executes an instruction
1550 at any address within the specified range. See the "PowerPC Embedded"
1551 section in the user manual for more details.
1553 * New features in the GDB remote stub, GDBserver
1555 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1556 and i686 LynxOS (version 5.x).
1558 ** GDBserver is now supported on Blackfin Linux.
1560 * New native configurations
1562 ia64 HP-UX ia64-*-hpux*
1566 Analog Devices, Inc. Blackfin Processor bfin-*
1568 * Ada task switching is now supported on sparc-elf targets when
1569 debugging a program using the Ravenscar Profile. For more information,
1570 see the "Tasking Support when using the Ravenscar Profile" section
1571 in the GDB user manual.
1573 * Guile support was removed.
1575 * New features in the GNU simulator
1577 ** The --map-info flag lists all known core mappings.
1579 ** CFI flashes may be simulated via the "cfi" device.
1581 *** Changes in GDB 7.2
1583 * Shared library support for remote targets by default
1585 When GDB is configured for a generic, non-OS specific target, like
1586 for example, --target=arm-eabi or one of the many *-*-elf targets,
1587 GDB now queries remote stubs for loaded shared libraries using the
1588 `qXfer:libraries:read' packet. Previously, shared library support
1589 was always disabled for such configurations.
1593 ** Argument Dependent Lookup (ADL)
1595 In C++ ADL lookup directs function search to the namespaces of its
1596 arguments even if the namespace has not been imported.
1606 Here the compiler will search for `foo' in the namespace of 'b'
1607 and find A::foo. GDB now supports this. This construct is commonly
1608 used in the Standard Template Library for operators.
1610 ** Improved User Defined Operator Support
1612 In addition to member operators, GDB now supports lookup of operators
1613 defined in a namespace and imported with a `using' directive, operators
1614 defined in the global scope, operators imported implicitly from an
1615 anonymous namespace, and the ADL operators mentioned in the previous
1617 GDB now also supports proper overload resolution for all the previously
1618 mentioned flavors of operators.
1620 ** static const class members
1622 Printing of static const class members that are initialized in the
1623 class definition has been fixed.
1625 * Windows Thread Information Block access.
1627 On Windows targets, GDB now supports displaying the Windows Thread
1628 Information Block (TIB) structure. This structure is visible either
1629 by using the new command `info w32 thread-information-block' or, by
1630 dereferencing the new convenience variable named `$_tlb', a
1631 thread-specific pointer to the TIB. This feature is also supported
1632 when remote debugging using GDBserver.
1634 * Static tracepoints
1636 Static tracepoints are calls in the user program into a tracing
1637 library. One such library is a port of the LTTng kernel tracer to
1638 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1639 When debugging with GDBserver, GDB now supports combining the GDB
1640 tracepoint machinery with such libraries. For example: the user can
1641 use GDB to probe a static tracepoint marker (a call from the user
1642 program into the tracing library) with the new "strace" command (see
1643 "New commands" below). This creates a "static tracepoint" in the
1644 breakpoint list, that can be manipulated with the same feature set
1645 as fast and regular tracepoints. E.g., collect registers, local and
1646 global variables, collect trace state variables, and define
1647 tracepoint conditions. In addition, the user can collect extra
1648 static tracepoint marker specific data, by collecting the new
1649 $_sdata internal variable. When analyzing the trace buffer, you can
1650 inspect $_sdata like any other variable available to GDB. For more
1651 information, see the "Tracepoints" chapter in GDB user manual. New
1652 remote packets have been defined to support static tracepoints, see
1653 the "New remote packets" section below.
1655 * Better reconstruction of tracepoints after disconnected tracing
1657 GDB will attempt to download the original source form of tracepoint
1658 definitions when starting a trace run, and then will upload these
1659 upon reconnection to the target, resulting in a more accurate
1660 reconstruction of the tracepoints that are in use on the target.
1664 You can now exercise direct control over the ways that GDB can
1665 affect your program. For instance, you can disallow the setting of
1666 breakpoints, so that the program can run continuously (assuming
1667 non-stop mode). In addition, the "observer" variable is available
1668 to switch all of the different controls; in observer mode, GDB
1669 cannot affect the target's behavior at all, which is useful for
1670 tasks like diagnosing live systems in the field.
1672 * The new convenience variable $_thread holds the number of the
1675 * New remote packets
1679 Return the address of the Windows Thread Information Block of a given thread.
1683 In response to several of the tracepoint packets, the target may now
1684 also respond with a number of intermediate `qRelocInsn' request
1685 packets before the final result packet, to have GDB handle
1686 relocating an instruction to execute at a different address. This
1687 is particularly useful for stubs that support fast tracepoints. GDB
1688 reports support for this feature in the qSupported packet.
1692 List static tracepoint markers in the target program.
1696 List static tracepoint markers at a given address in the target
1699 qXfer:statictrace:read
1701 Read the static trace data collected (by a `collect $_sdata'
1702 tracepoint action). The remote stub reports support for this packet
1703 to gdb's qSupported query.
1707 Send the current settings of GDB's permission flags.
1711 Send part of the source (textual) form of a tracepoint definition,
1712 which includes location, conditional, and action list.
1714 * The source command now accepts a -s option to force searching for the
1715 script in the source search path even if the script name specifies
1718 * New features in the GDB remote stub, GDBserver
1720 - GDBserver now support tracepoints (including fast tracepoints, and
1721 static tracepoints). The feature is currently supported by the
1722 i386-linux and amd64-linux builds. See the "Tracepoints support
1723 in gdbserver" section in the manual for more information.
1725 GDBserver JIT compiles the tracepoint's conditional agent
1726 expression bytecode into native code whenever possible for low
1727 overhead dynamic tracepoints conditionals. For such tracepoints,
1728 an expression that examines program state is evaluated when the
1729 tracepoint is reached, in order to determine whether to capture
1730 trace data. If the condition is simple and false, processing the
1731 tracepoint finishes very quickly and no data is gathered.
1733 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1734 for static tracepoints support.
1736 - GDBserver now supports x86_64 Windows 64-bit debugging.
1738 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1739 it understands register description.
1741 * The --batch flag now disables pagination and queries.
1743 * X86 general purpose registers
1745 GDB now supports reading/writing byte, word and double-word x86
1746 general purpose registers directly. This means you can use, say,
1747 $ah or $ax to refer, respectively, to the byte register AH and
1748 16-bit word register AX that are actually portions of the 32-bit
1749 register EAX or 64-bit register RAX.
1751 * The `commands' command now accepts a range of breakpoints to modify.
1752 A plain `commands' following a command that creates multiple
1753 breakpoints affects all the breakpoints set by that command. This
1754 applies to breakpoints set by `rbreak', and also applies when a
1755 single `break' command creates multiple breakpoints (e.g.,
1756 breakpoints on overloaded c++ functions).
1758 * The `rbreak' command now accepts a filename specification as part of
1759 its argument, limiting the functions selected by the regex to those
1760 in the specified file.
1762 * Support for remote debugging Windows and SymbianOS shared libraries
1763 from Unix hosts has been improved. Non Windows GDB builds now can
1764 understand target reported file names that follow MS-DOS based file
1765 system semantics, such as file names that include drive letters and
1766 use the backslash character as directory separator. This makes it
1767 possible to transparently use the "set sysroot" and "set
1768 solib-search-path" on Unix hosts to point as host copies of the
1769 target's shared libraries. See the new command "set
1770 target-file-system-kind" described below, and the "Commands to
1771 specify files" section in the user manual for more information.
1775 eval template, expressions...
1776 Convert the values of one or more expressions under the control
1777 of the string template to a command line, and call it.
1779 set target-file-system-kind unix|dos-based|auto
1780 show target-file-system-kind
1781 Set or show the assumed file system kind for target reported file
1784 save breakpoints <filename>
1785 Save all current breakpoint definitions to a file suitable for use
1786 in a later debugging session. To read the saved breakpoint
1787 definitions, use the `source' command.
1789 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1792 info static-tracepoint-markers
1793 Display information about static tracepoint markers in the target.
1795 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1796 Define a static tracepoint by probing a marker at the given
1797 function, line, address, or marker ID.
1801 Enable and disable observer mode.
1803 set may-write-registers on|off
1804 set may-write-memory on|off
1805 set may-insert-breakpoints on|off
1806 set may-insert-tracepoints on|off
1807 set may-insert-fast-tracepoints on|off
1808 set may-interrupt on|off
1809 Set individual permissions for GDB effects on the target. Note that
1810 some of these settings can have undesirable or surprising
1811 consequences, particularly when changed in the middle of a session.
1812 For instance, disabling the writing of memory can prevent
1813 breakpoints from being inserted, cause single-stepping to fail, or
1814 even crash your program, if you disable after breakpoints have been
1815 inserted. However, GDB should not crash.
1817 set record memory-query on|off
1818 show record memory-query
1819 Control whether to stop the inferior if memory changes caused
1820 by an instruction cannot be recorded.
1825 The disassemble command now supports "start,+length" form of two arguments.
1829 ** GDB now provides a new directory location, called the python directory,
1830 where Python scripts written for GDB can be installed. The location
1831 of that directory is <data-directory>/python, where <data-directory>
1832 is the GDB data directory. For more details, see section `Scripting
1833 GDB using Python' in the manual.
1835 ** The GDB Python API now has access to breakpoints, symbols, symbol
1836 tables, program spaces, inferiors, threads and frame's code blocks.
1837 Additionally, GDB Parameters can now be created from the API, and
1838 manipulated via set/show in the CLI.
1840 ** New functions gdb.target_charset, gdb.target_wide_charset,
1841 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1843 ** New exception gdb.GdbError.
1845 ** Pretty-printers are now also looked up in the current program space.
1847 ** Pretty-printers can now be individually enabled and disabled.
1849 ** GDB now looks for names of Python scripts to auto-load in a
1850 special section named `.debug_gdb_scripts', in addition to looking
1851 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1853 * Tracepoint actions were unified with breakpoint commands. In particular,
1854 there are no longer differences in "info break" output for breakpoints and
1855 tracepoints and the "commands" command can be used for both tracepoints and
1856 regular breakpoints.
1860 ARM Symbian arm*-*-symbianelf*
1862 * D language support.
1863 GDB now supports debugging programs written in the D programming
1866 * GDB now supports the extended ptrace interface for PowerPC which is
1867 available since Linux kernel version 2.6.34. This automatically enables
1868 any hardware breakpoints and additional hardware watchpoints available in
1869 the processor. The old ptrace interface exposes just one hardware
1870 watchpoint and no hardware breakpoints.
1872 * GDB is now able to use the Data Value Compare (DVC) register available on
1873 embedded PowerPC processors to implement in hardware simple watchpoint
1874 conditions of the form:
1876 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1878 This works in native GDB running on Linux kernels with the extended ptrace
1879 interface mentioned above.
1881 *** Changes in GDB 7.1
1885 ** Namespace Support
1887 GDB now supports importing of namespaces in C++. This enables the
1888 user to inspect variables from imported namespaces. Support for
1889 namepace aliasing has also been added. So, if a namespace is
1890 aliased in the current scope (e.g. namepace C=A; ) the user can
1891 print variables using the alias (e.g. (gdb) print C::x).
1895 All known bugs relating to the printing of virtual base class were
1896 fixed. It is now possible to call overloaded static methods using a
1901 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1902 and reinterpret_cast<> are now handled by the C++ expression parser.
1906 Xilinx MicroBlaze microblaze-*-*
1911 Xilinx MicroBlaze microblaze
1914 * Multi-program debugging.
1916 GDB now has support for multi-program (a.k.a. multi-executable or
1917 multi-exec) debugging. This allows for debugging multiple inferiors
1918 simultaneously each running a different program under the same GDB
1919 session. See "Debugging Multiple Inferiors and Programs" in the
1920 manual for more information. This implied some user visible changes
1921 in the multi-inferior support. For example, "info inferiors" now
1922 lists inferiors that are not running yet or that have exited
1923 already. See also "New commands" and "New options" below.
1925 * New tracing features
1927 GDB's tracepoint facility now includes several new features:
1929 ** Trace state variables
1931 GDB tracepoints now include support for trace state variables, which
1932 are variables managed by the target agent during a tracing
1933 experiment. They are useful for tracepoints that trigger each
1934 other, so for instance one tracepoint can count hits in a variable,
1935 and then a second tracepoint has a condition that is true when the
1936 count reaches a particular value. Trace state variables share the
1937 $-syntax of GDB convenience variables, and can appear in both
1938 tracepoint actions and condition expressions. Use the "tvariable"
1939 command to create, and "info tvariables" to view; see "Trace State
1940 Variables" in the manual for more detail.
1944 GDB now includes an option for defining fast tracepoints, which
1945 targets may implement more efficiently, such as by installing a jump
1946 into the target agent rather than a trap instruction. The resulting
1947 speedup can be by two orders of magnitude or more, although the
1948 tradeoff is that some program locations on some target architectures
1949 might not allow fast tracepoint installation, for instance if the
1950 instruction to be replaced is shorter than the jump. To request a
1951 fast tracepoint, use the "ftrace" command, with syntax identical to
1952 the regular trace command.
1954 ** Disconnected tracing
1956 It is now possible to detach GDB from the target while it is running
1957 a trace experiment, then reconnect later to see how the experiment
1958 is going. In addition, a new variable disconnected-tracing lets you
1959 tell the target agent whether to continue running a trace if the
1960 connection is lost unexpectedly.
1964 GDB now has the ability to save the trace buffer into a file, and
1965 then use that file as a target, similarly to you can do with
1966 corefiles. You can select trace frames, print data that was
1967 collected in them, and use tstatus to display the state of the
1968 tracing run at the moment that it was saved. To create a trace
1969 file, use "tsave <filename>", and to use it, do "target tfile
1972 ** Circular trace buffer
1974 You can ask the target agent to handle the trace buffer as a
1975 circular buffer, discarding the oldest trace frames to make room for
1976 newer ones, by setting circular-trace-buffer to on. This feature may
1977 not be available for all target agents.
1982 The disassemble command, when invoked with two arguments, now requires
1983 the arguments to be comma-separated.
1986 The info variables command now displays variable definitions. Files
1987 which only declare a variable are not shown.
1990 The source command is now capable of sourcing Python scripts.
1991 This feature is dependent on the debugger being build with Python
1994 Related to this enhancement is also the introduction of a new command
1995 "set script-extension" (see below).
1997 * New commands (for set/show, see "New options" below)
1999 record save [<FILENAME>]
2000 Save a file (in core file format) containing the process record
2001 execution log for replay debugging at a later time.
2003 record restore <FILENAME>
2004 Restore the process record execution log that was saved at an
2005 earlier time, for replay debugging.
2007 add-inferior [-copies <N>] [-exec <FILENAME>]
2010 clone-inferior [-copies <N>] [ID]
2011 Make a new inferior ready to execute the same program another
2012 inferior has loaded.
2017 maint info program-spaces
2018 List the program spaces loaded into GDB.
2020 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2021 show remote interrupt-sequence
2022 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2023 as the sequence to the remote target in order to interrupt the execution.
2024 Ctrl-C is a default. Some system prefers BREAK which is high level of
2025 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2026 Magic SysRq g. It is BREAK signal and character 'g'.
2028 set remote interrupt-on-connect [on | off]
2029 show remote interrupt-on-connect
2030 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2031 remote target when gdb connects to it. This is needed when you debug
2034 set remotebreak [on | off]
2036 Deprecated. Use "set/show remote interrupt-sequence" instead.
2038 tvariable $NAME [ = EXP ]
2039 Create or modify a trace state variable.
2042 List trace state variables and their values.
2044 delete tvariable $NAME ...
2045 Delete one or more trace state variables.
2048 Evaluate the given expressions without collecting anything into the
2049 trace buffer. (Valid in tracepoint actions only.)
2051 ftrace FN / FILE:LINE / *ADDR
2052 Define a fast tracepoint at the given function, line, or address.
2054 * New expression syntax
2056 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2057 GDB now parses 0b101010 identically with 42.
2061 set follow-exec-mode new|same
2062 show follow-exec-mode
2063 Control whether GDB reuses the same inferior across an exec call or
2064 creates a new one. This is useful to be able to restart the old
2065 executable after the inferior having done an exec call.
2067 set default-collect EXPR, ...
2068 show default-collect
2069 Define a list of expressions to be collected at each tracepoint.
2070 This is a useful way to ensure essential items are not overlooked,
2071 such as registers or a critical global variable.
2073 set disconnected-tracing
2074 show disconnected-tracing
2075 If set to 1, the target is instructed to continue tracing if it
2076 loses its connection to GDB. If 0, the target is to stop tracing
2079 set circular-trace-buffer
2080 show circular-trace-buffer
2081 If set to on, the target is instructed to use a circular trace buffer
2082 and discard the oldest trace frames instead of stopping the trace due
2083 to a full trace buffer. If set to off, the trace stops when the buffer
2084 fills up. Some targets may not support this.
2086 set script-extension off|soft|strict
2087 show script-extension
2088 If set to "off", the debugger does not perform any script language
2089 recognition, and all sourced files are assumed to be GDB scripts.
2090 If set to "soft" (the default), files are sourced according to
2091 filename extension, falling back to GDB scripts if the first
2093 If set to "strict", files are sourced according to filename extension.
2095 set ada trust-PAD-over-XVS on|off
2096 show ada trust-PAD-over-XVS
2097 If off, activate a workaround against a bug in the debugging information
2098 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2099 the GCC sources for more information about the GNAT encoding and
2100 PAD types in particular). It is always safe to set this option to
2101 off, but this introduces a slight performance penalty. The default
2104 * Python API Improvements
2106 ** GDB provides the new class gdb.LazyString. This is useful in
2107 some pretty-printing cases. The new method gdb.Value.lazy_string
2108 provides a simple way to create objects of this type.
2110 ** The fields returned by gdb.Type.fields now have an
2111 `is_base_class' attribute.
2113 ** The new method gdb.Type.range returns the range of an array type.
2115 ** The new method gdb.parse_and_eval can be used to parse and
2116 evaluate an expression.
2118 * New remote packets
2121 Define a trace state variable.
2124 Get the current value of a trace state variable.
2127 Set desired tracing behavior upon disconnection.
2130 Set the trace buffer to be linear or circular.
2133 Get data about the tracepoints currently in use.
2137 Process record now works correctly with hardware watchpoints.
2139 Multiple bug fixes have been made to the mips-irix port, making it
2140 much more reliable. In particular:
2141 - Debugging threaded applications is now possible again. Previously,
2142 GDB would hang while starting the program, or while waiting for
2143 the program to stop at a breakpoint.
2144 - Attaching to a running process no longer hangs.
2145 - An error occurring while loading a core file has been fixed.
2146 - Changing the value of the PC register now works again. This fixes
2147 problems observed when using the "jump" command, or when calling
2148 a function from GDB, or even when assigning a new value to $pc.
2149 - With the "finish" and "return" commands, the return value for functions
2150 returning a small array is now correctly printed.
2151 - It is now possible to break on shared library code which gets executed
2152 during a shared library init phase (code executed while executing
2153 their .init section). Previously, the breakpoint would have no effect.
2154 - GDB is now able to backtrace through the signal handler for
2155 non-threaded programs.
2157 PIE (Position Independent Executable) programs debugging is now supported.
2158 This includes debugging execution of PIC (Position Independent Code) shared
2159 libraries although for that, it should be possible to run such libraries as an
2162 *** Changes in GDB 7.0
2164 * GDB now has an interface for JIT compilation. Applications that
2165 dynamically generate code can create symbol files in memory and register
2166 them with GDB. For users, the feature should work transparently, and
2167 for JIT developers, the interface is documented in the GDB manual in the
2168 "JIT Compilation Interface" chapter.
2170 * Tracepoints may now be conditional. The syntax is as for
2171 breakpoints; either an "if" clause appended to the "trace" command,
2172 or the "condition" command is available. GDB sends the condition to
2173 the target for evaluation using the same bytecode format as is used
2174 for tracepoint actions.
2176 * The disassemble command now supports: an optional /r modifier, print the
2177 raw instructions in hex as well as in symbolic form, and an optional /m
2178 modifier to print mixed source+assembly.
2180 * Process record and replay
2182 In a architecture environment that supports ``process record and
2183 replay'', ``process record and replay'' target can record a log of
2184 the process execution, and replay it with both forward and reverse
2187 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2188 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2189 set execution-direction {forward|reverse}, for targets that support
2192 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2193 feature is available with a native GDB running on kernel version
2196 * GDB now has support for multi-byte and wide character sets on the
2197 target. Strings whose character type is wchar_t, char16_t, or
2198 char32_t are now correctly printed. GDB supports wide- and unicode-
2199 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2200 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2201 `printf'. This feature requires iconv to work properly; if your
2202 system does not have a working iconv, GDB can use GNU libiconv. See
2203 the installation instructions for more information.
2205 * GDB now supports automatic retrieval of shared library files from
2206 remote targets. To use this feature, specify a system root that begins
2207 with the `remote:' prefix, either via the `set sysroot' command or via
2208 the `--with-sysroot' configure-time option.
2210 * "info sharedlibrary" now takes an optional regex of libraries to show,
2211 and it now reports if a shared library has no debugging information.
2213 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2214 now complete on file names.
2216 * When completing in expressions, gdb will attempt to limit
2217 completions to allowable structure or union fields, where appropriate.
2218 For instance, consider:
2220 # struct example { int f1; double f2; };
2221 # struct example variable;
2224 If the user types TAB at the end of this command line, the available
2225 completions will be "f1" and "f2".
2227 * Inlined functions are now supported. They show up in backtraces, and
2228 the "step", "next", and "finish" commands handle them automatically.
2230 * GDB now supports the token-splicing (##) and stringification (#)
2231 operators when expanding macros. It also supports variable-arity
2234 * GDB now supports inspecting extra signal information, exported by
2235 the new $_siginfo convenience variable. The feature is currently
2236 implemented on linux ARM, i386 and amd64.
2238 * GDB can now display the VFP floating point registers and NEON vector
2239 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2240 can provide these registers (requires Linux 2.6.30 or later). Remote
2241 and simulator targets may also provide them.
2243 * New remote packets
2246 Search memory for a sequence of bytes.
2249 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2250 operation over reliable transport links. Use of this packet is
2251 controlled by the `set remote noack-packet' command.
2254 Kill the process with the specified process ID. Use this in preference
2255 to `k' when multiprocess protocol extensions are supported.
2258 Obtains additional operating system information
2262 Read or write additional signal information.
2264 * Removed remote protocol undocumented extension
2266 An undocumented extension to the remote protocol's `S' stop reply
2267 packet that permited the stub to pass a process id was removed.
2268 Remote servers should use the `T' stop reply packet instead.
2270 * GDB now supports multiple function calling conventions according to the
2271 DWARF-2 DW_AT_calling_convention function attribute.
2273 * The SH target utilizes the aforementioned change to distinguish between gcc
2274 and Renesas calling convention. It also adds the new CLI commands
2275 `set/show sh calling-convention'.
2277 * GDB can now read compressed debug sections, as produced by GNU gold
2278 with the --compress-debug-sections=zlib flag.
2280 * 64-bit core files are now supported on AIX.
2282 * Thread switching is now supported on Tru64.
2284 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2285 which will be allocated using malloc later in program execution.
2287 * The qXfer:libraries:read remote procotol packet now allows passing a
2288 list of section offsets.
2290 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2291 conditions handling signals delivered during attach or thread creation
2292 have also been fixed.
2294 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2295 From the user's standpoint, all unqualified instances of True and False
2296 are treated as the standard definitions, regardless of context.
2298 * GDB now parses C++ symbol and type names more flexibly. For
2301 template<typename T> class C { };
2304 GDB will now correctly handle all of:
2306 ptype C<char const *>
2307 ptype C<char const*>
2308 ptype C<const char *>
2309 ptype C<const char*>
2311 * New features in the GDB remote stub, gdbserver
2313 - The "--wrapper" command-line argument tells gdbserver to use a
2314 wrapper program to launch programs for debugging.
2316 - On PowerPC and S/390 targets, it is now possible to use a single
2317 gdbserver executable to debug both 32-bit and 64-bit programs.
2318 (This requires gdbserver itself to be built as a 64-bit executable.)
2320 - gdbserver uses the new noack protocol mode for TCP connections to
2321 reduce communications latency, if also supported and enabled in GDB.
2323 - Support for the sparc64-linux-gnu target is now included in
2326 - The amd64-linux build of gdbserver now supports debugging both
2327 32-bit and 64-bit programs.
2329 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2330 now support hardware watchpoints, and will use them automatically
2335 GDB now has support for scripting using Python. Whether this is
2336 available is determined at configure time.
2338 New GDB commands can now be written in Python.
2340 * Ada tasking support
2342 Ada tasks can now be inspected in GDB. The following commands have
2346 Print the list of Ada tasks.
2348 Print detailed information about task number N.
2350 Print the task number of the current task.
2352 Switch the context of debugging to task number N.
2354 * Support for user-defined prefixed commands. The "define" command can
2355 add new commands to existing prefixes, e.g. "target".
2357 * Multi-inferior, multi-process debugging.
2359 GDB now has generalized support for multi-inferior debugging. See
2360 "Debugging Multiple Inferiors" in the manual for more information.
2361 Although availability still depends on target support, the command
2362 set is more uniform now. The GNU/Linux specific multi-forks support
2363 has been migrated to this new framework. This implied some user
2364 visible changes; see "New commands" and also "Removed commands"
2367 * Target descriptions can now describe the target OS ABI. See the
2368 "Target Description Format" section in the user manual for more
2371 * Target descriptions can now describe "compatible" architectures
2372 to indicate that the target can execute applications for a different
2373 architecture in addition to those for the main target architecture.
2374 See the "Target Description Format" section in the user manual for
2377 * Multi-architecture debugging.
2379 GDB now includes general supports for debugging applications on
2380 hybrid systems that use more than one single processor architecture
2381 at the same time. Each such hybrid architecture still requires
2382 specific support to be added. The only hybrid architecture supported
2383 in this version of GDB is the Cell Broadband Engine.
2385 * GDB now supports integrated debugging of Cell/B.E. applications that
2386 use both the PPU and SPU architectures. To enable support for hybrid
2387 Cell/B.E. debugging, you need to configure GDB to support both the
2388 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2389 --enable-targets configure option.
2391 * Non-stop mode debugging.
2393 For some targets, GDB now supports an optional mode of operation in
2394 which you can examine stopped threads while other threads continue
2395 to execute freely. This is referred to as non-stop mode, with the
2396 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2397 section in the user manual for more information.
2399 To be able to support remote non-stop debugging, a remote stub needs
2400 to implement the non-stop mode remote protocol extensions, as
2401 described in the "Remote Non-Stop" section of the user manual. The
2402 GDB remote stub, gdbserver, has been adjusted to support these
2403 extensions on linux targets.
2405 * New commands (for set/show, see "New options" below)
2407 catch syscall [NAME(S) | NUMBER(S)]
2408 Catch system calls. Arguments, which should be names of system
2409 calls or their numbers, mean catch only those syscalls. Without
2410 arguments, every syscall will be caught. When the inferior issues
2411 any of the specified syscalls, GDB will stop and announce the system
2412 call, both when it is called and when its call returns. This
2413 feature is currently available with a native GDB running on the
2414 Linux Kernel, under the following architectures: x86, x86_64,
2415 PowerPC and PowerPC64.
2417 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2419 Search memory for a sequence of bytes.
2421 maint set python print-stack
2422 maint show python print-stack
2423 Show a stack trace when an error is encountered in a Python script.
2426 Invoke CODE by passing it to the Python interpreter.
2431 These allow macros to be defined, undefined, and listed
2435 Show operating system information about processes.
2438 List the inferiors currently under GDB's control.
2441 Switch focus to inferior number NUM.
2444 Detach from inferior number NUM.
2447 Kill inferior number NUM.
2451 set spu stop-on-load
2452 show spu stop-on-load
2453 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2455 set spu auto-flush-cache
2456 show spu auto-flush-cache
2457 Control whether to automatically flush the software-managed cache
2458 during Cell/B.E. debugging.
2460 set sh calling-convention
2461 show sh calling-convention
2462 Control the calling convention used when calling SH target functions.
2465 show debug timestamp
2466 Control display of timestamps with GDB debugging output.
2468 set disassemble-next-line
2469 show disassemble-next-line
2470 Control display of disassembled source lines or instructions when
2473 set remote noack-packet
2474 show remote noack-packet
2475 Set/show the use of remote protocol QStartNoAckMode packet. See above
2476 under "New remote packets."
2478 set remote query-attached-packet
2479 show remote query-attached-packet
2480 Control use of remote protocol `qAttached' (query-attached) packet.
2482 set remote read-siginfo-object
2483 show remote read-siginfo-object
2484 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2487 set remote write-siginfo-object
2488 show remote write-siginfo-object
2489 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2492 set remote reverse-continue
2493 show remote reverse-continue
2494 Control use of remote protocol 'bc' (reverse-continue) packet.
2496 set remote reverse-step
2497 show remote reverse-step
2498 Control use of remote protocol 'bs' (reverse-step) packet.
2500 set displaced-stepping
2501 show displaced-stepping
2502 Control displaced stepping mode. Displaced stepping is a way to
2503 single-step over breakpoints without removing them from the debuggee.
2504 Also known as "out-of-line single-stepping".
2507 show debug displaced
2508 Control display of debugging info for displaced stepping.
2510 maint set internal-error
2511 maint show internal-error
2512 Control what GDB does when an internal error is detected.
2514 maint set internal-warning
2515 maint show internal-warning
2516 Control what GDB does when an internal warning is detected.
2521 Use a wrapper program to launch programs for debugging.
2523 set multiple-symbols (all|ask|cancel)
2524 show multiple-symbols
2525 The value of this variable can be changed to adjust the debugger behavior
2526 when an expression or a breakpoint location contains an ambiguous symbol
2527 name (an overloaded function name, for instance).
2529 set breakpoint always-inserted
2530 show breakpoint always-inserted
2531 Keep breakpoints always inserted in the target, as opposed to inserting
2532 them when resuming the target, and removing them when the target stops.
2533 This option can improve debugger performance on slow remote targets.
2535 set arm fallback-mode (arm|thumb|auto)
2536 show arm fallback-mode
2537 set arm force-mode (arm|thumb|auto)
2539 These commands control how ARM GDB determines whether instructions
2540 are ARM or Thumb. The default for both settings is auto, which uses
2541 the current CPSR value for instructions without symbols; previous
2542 versions of GDB behaved as if "set arm fallback-mode arm".
2544 set disable-randomization
2545 show disable-randomization
2546 Standalone programs run with the virtual address space randomization enabled
2547 by default on some platforms. This option keeps the addresses stable across
2548 multiple debugging sessions.
2552 Control whether other threads are stopped or not when some thread hits
2557 Requests that asynchronous execution is enabled in the target, if available.
2558 In this case, it's possible to resume target in the background, and interact
2559 with GDB while the target is running. "show target-async" displays the
2560 current state of asynchronous execution of the target.
2562 set target-wide-charset
2563 show target-wide-charset
2564 The target-wide-charset is the name of the character set that GDB
2565 uses when printing characters whose type is wchar_t.
2567 set tcp auto-retry (on|off)
2569 set tcp connect-timeout
2570 show tcp connect-timeout
2571 These commands allow GDB to retry failed TCP connections to a remote stub
2572 with a specified timeout period; this is useful if the stub is launched
2573 in parallel with GDB but may not be ready to accept connections immediately.
2575 set libthread-db-search-path
2576 show libthread-db-search-path
2577 Control list of directories which GDB will search for appropriate
2580 set schedule-multiple (on|off)
2581 show schedule-multiple
2582 Allow GDB to resume all threads of all processes or only threads of
2583 the current process.
2587 Use more aggressive caching for accesses to the stack. This improves
2588 performance of remote debugging (particularly backtraces) without
2589 affecting correctness.
2591 set interactive-mode (on|off|auto)
2592 show interactive-mode
2593 Control whether GDB runs in interactive mode (on) or not (off).
2594 When in interactive mode, GDB waits for the user to answer all
2595 queries. Otherwise, GDB does not wait and assumes the default
2596 answer. When set to auto (the default), GDB determines which
2597 mode to use based on the stdin settings.
2602 For program forks, this is replaced by the new more generic `info
2603 inferiors' command. To list checkpoints, you can still use the
2604 `info checkpoints' command, which was an alias for the `info forks'
2608 Replaced by the new `inferior' command. To switch between
2609 checkpoints, you can still use the `restart' command, which was an
2610 alias for the `fork' command.
2613 This is removed, since some targets don't have a notion of
2614 processes. To switch between processes, you can still use the
2615 `inferior' command using GDB's own inferior number.
2618 For program forks, this is replaced by the new more generic `kill
2619 inferior' command. To delete a checkpoint, you can still use the
2620 `delete checkpoint' command, which was an alias for the `delete
2624 For program forks, this is replaced by the new more generic `detach
2625 inferior' command. To detach a checkpoint, you can still use the
2626 `detach checkpoint' command, which was an alias for the `detach
2629 * New native configurations
2631 x86/x86_64 Darwin i[34567]86-*-darwin*
2633 x86_64 MinGW x86_64-*-mingw*
2637 Lattice Mico32 lm32-*
2638 x86 DICOS i[34567]86-*-dicos*
2639 x86_64 DICOS x86_64-*-dicos*
2642 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2643 (mingw32ce) debugging.
2649 These commands were actually not implemented on any target.
2651 *** Changes in GDB 6.8
2653 * New native configurations
2655 NetBSD/hppa hppa*-*netbsd*
2656 Xtensa GNU/Linux xtensa*-*-linux*
2660 NetBSD/hppa hppa*-*-netbsd*
2661 Xtensa GNU/Lunux xtensa*-*-linux*
2663 * Change in command line behavior -- corefiles vs. process ids.
2665 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2666 attaching to process NUMBER fails, GDB no longer attempts to open a
2667 core file named NUMBER. Attaching to a program using the -c option
2668 is no longer supported. Instead, use the '-p' or '--pid' options.
2670 * GDB can now be built as a native debugger for debugging Windows x86
2671 (mingw32) Portable Executable (PE) programs.
2673 * Pending breakpoints no longer change their number when their address
2676 * GDB now supports breakpoints with multiple locations,
2677 including breakpoints on C++ constructors, inside C++ templates,
2678 and in inlined functions.
2680 * GDB's ability to debug optimized code has been improved. GDB more
2681 accurately identifies function bodies and lexical blocks that occupy
2682 more than one contiguous range of addresses.
2684 * Target descriptions can now describe registers for PowerPC.
2686 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2687 registers on PowerPC targets.
2689 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2690 targets even when the libthread_db library is not available.
2692 * The GDB remote stub, gdbserver, now supports the new file transfer
2693 commands (remote put, remote get, and remote delete).
2695 * The GDB remote stub, gdbserver, now supports run and attach in
2696 extended-remote mode.
2698 * hppa*64*-*-hpux11* target broken
2699 The debugger is unable to start a program and fails with the following
2700 error: "Error trying to get information about dynamic linker".
2701 The gdb-6.7 release is also affected.
2703 * GDB now supports the --enable-targets= configure option to allow
2704 building a single GDB executable that supports multiple remote
2705 target architectures.
2707 * GDB now supports debugging C and C++ programs which use the
2708 Decimal Floating Point extension. In addition, the PowerPC target
2709 now has a set of pseudo-registers to inspect decimal float values
2710 stored in two consecutive float registers.
2712 * The -break-insert MI command can optionally create pending
2715 * Improved support for debugging Ada
2716 Many improvements to the Ada language support have been made. These
2718 - Better support for Ada2005 interface types
2719 - Improved handling of arrays and slices in general
2720 - Better support for Taft-amendment types
2721 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2723 - Improved command completion in Ada
2726 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2731 set print frame-arguments (all|scalars|none)
2732 show print frame-arguments
2733 The value of this variable can be changed to control which argument
2734 values should be printed by the debugger when displaying a frame.
2739 Transfer files to and from a remote target, and delete remote files.
2746 Transfer files to and from a remote target, and delete remote files.
2748 * New remote packets
2755 Open, close, read, write, and delete files on the remote system.
2758 Attach to an existing process on the remote system, in extended-remote
2762 Run a new process on the remote system, in extended-remote mode.
2764 *** Changes in GDB 6.7
2766 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2767 bfd, libiberty and opcodes, as revealed by static analysis donated by
2768 Coverity, Inc. (http://scan.coverity.com).
2770 * When looking up multiply-defined global symbols, GDB will now prefer the
2771 symbol definition in the current shared library if it was built using the
2772 -Bsymbolic linker option.
2774 * When the Text User Interface (TUI) is not configured, GDB will now
2775 recognize the -tui command-line option and print a message that the TUI
2778 * The GDB remote stub, gdbserver, now has lower overhead for high
2779 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2781 * GDB for MIPS targets now autodetects whether a remote target provides
2782 32-bit or 64-bit register values.
2784 * Support for C++ member pointers has been improved.
2786 * GDB now understands XML target descriptions, which specify the
2787 target's overall architecture. GDB can read a description from
2788 a local file or over the remote serial protocol.
2790 * Vectors of single-byte data use a new integer type which is not
2791 automatically displayed as character or string data.
2793 * The /s format now works with the print command. It displays
2794 arrays of single-byte integers and pointers to single-byte integers
2797 * Target descriptions can now describe target-specific registers,
2798 for architectures which have implemented the support (currently
2799 only ARM, M68K, and MIPS).
2801 * GDB and the GDB remote stub, gdbserver, now support the XScale
2804 * The GDB remote stub, gdbserver, has been updated to support
2805 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2806 has been rewritten to use the standard GDB remote protocol.
2808 * GDB can now step into C++ functions which are called through thunks.
2810 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2812 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2813 layout. It also supports a TextSeg= and DataSeg= response when only
2814 segment base addresses (rather than offsets) are available.
2816 * The /i format now outputs any trailing branch delay slot instructions
2817 immediately following the last instruction within the count specified.
2819 * The GDB remote protocol "T" stop reply packet now supports a
2820 "library" response. Combined with the new "qXfer:libraries:read"
2821 packet, this response allows GDB to debug shared libraries on targets
2822 where the operating system manages the list of loaded libraries (e.g.
2823 Windows and SymbianOS).
2825 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2826 (DLLs) on Windows and Windows CE targets.
2828 * GDB now supports a faster verification that a .debug file matches its binary
2829 according to its build-id signature, if the signature is present.
2835 Enable or disable hardware flow control (RTS/CTS) on the serial port
2836 when debugging using remote targets.
2838 set mem inaccessible-by-default
2839 show mem inaccessible-by-default
2840 If the target supplies a memory map, for instance via the remote
2841 protocol's "qXfer:memory-map:read" packet, setting this variable
2842 prevents GDB from accessing memory outside the memory map. This
2843 is useful for targets with memory mapped registers or which react
2844 badly to accesses of unmapped address space.
2846 set breakpoint auto-hw
2847 show breakpoint auto-hw
2848 If the target supplies a memory map, for instance via the remote
2849 protocol's "qXfer:memory-map:read" packet, setting this variable
2850 lets GDB use hardware breakpoints automatically for memory regions
2851 where it can not use software breakpoints. This covers both the
2852 "break" command and internal breakpoints used for other commands
2853 including "next" and "finish".
2856 catch exception unhandled
2857 Stop the program execution when Ada exceptions are raised.
2860 Stop the program execution when an Ada assertion failed.
2864 Set an alternate system root for target files. This is a more
2865 general version of "set solib-absolute-prefix", which is now
2866 an alias to "set sysroot".
2869 Provide extended SPU facility status information. This set of
2870 commands is available only when debugging the Cell/B.E. SPU
2873 * New native configurations
2875 OpenBSD/sh sh*-*openbsd*
2878 unset tdesc filename
2880 Use the specified local file as an XML target description, and do
2881 not query the target for its built-in description.
2885 OpenBSD/sh sh*-*-openbsd*
2886 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2887 Toshiba Media Processor mep-elf
2889 * New remote packets
2892 Ignore the specified signals; pass them directly to the debugged program
2893 without stopping other threads or reporting them to GDB.
2895 qXfer:features:read:
2896 Read an XML target description from the target, which describes its
2901 Read or write contents of an spufs file on the target system. These
2902 packets are available only on the Cell/B.E. SPU architecture.
2904 qXfer:libraries:read:
2905 Report the loaded shared libraries. Combined with new "T" packet
2906 response, this packet allows GDB to debug shared libraries on
2907 targets where the operating system manages the list of loaded
2908 libraries (e.g. Windows and SymbianOS).
2912 Support for these obsolete configurations has been removed.
2920 i[34567]86-*-lynxos*
2921 i[34567]86-*-netware*
2922 i[34567]86-*-sco3.2v5*
2923 i[34567]86-*-sco3.2v4*
2925 i[34567]86-*-sysv4.2*
2928 i[34567]86-*-unixware2*
2929 i[34567]86-*-unixware*
2938 * Other removed features
2945 Various m68k-only ROM monitors.
2952 Various Renesas ROM monitors and debugging interfaces for SH and
2957 Support for a Macraigor serial interface to on-chip debugging.
2958 GDB does not directly support the newer parallel or USB
2963 A debug information format. The predecessor to DWARF 2 and
2964 DWARF 3, which are still supported.
2966 Support for the HP aCC compiler on HP-UX/PA-RISC
2968 SOM-encapsulated symbolic debugging information, automatic
2969 invocation of pxdb, and the aCC custom C++ ABI. This does not
2970 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2971 with aCC can still be debugged on an assembly level.
2973 MIPS ".pdr" sections
2975 A MIPS-specific format used to describe stack frame layout
2976 in debugging information.
2980 GDB could work with an older version of Guile to debug
2981 the interpreter and Scheme programs running in it.
2983 set mips stack-arg-size
2984 set mips saved-gpreg-size
2986 Use "set mips abi" to control parameter passing for MIPS.
2988 *** Changes in GDB 6.6
2993 Cell Broadband Engine SPU spu-elf
2995 * GDB can now be configured as a cross-debugger targeting native Windows
2996 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2997 running on a Windows system over TCP/IP to debug Windows programs.
2999 * The GDB remote stub, gdbserver, has been updated to support Windows and
3000 Cygwin debugging. Both single-threaded and multi-threaded programs are
3003 * The "set trust-readonly-sections" command works again. This command was
3004 broken in GDB 6.3, 6.4, and 6.5.
3006 * The "load" command now supports writing to flash memory, if the remote
3007 stub provides the required support.
3009 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3010 longer requires symbolic debug information (e.g. DWARF-2).
3015 unset substitute-path
3016 show substitute-path
3017 Manage a list of substitution rules that GDB uses to rewrite the name
3018 of the directories where the sources are located. This can be useful
3019 for instance when the sources were moved to a different location
3020 between compilation and debugging.
3024 Print each CLI command as it is executed. Each command is prefixed with
3025 a number of `+' symbols representing the nesting depth.
3026 The source command now has a `-v' option to enable the same feature.
3030 The ARM Demon monitor support (RDP protocol, "target rdp").
3032 Kernel Object Display, an embedded debugging feature which only worked with
3033 an obsolete version of Cisco IOS.
3035 The 'set download-write-size' and 'show download-write-size' commands.
3037 * New remote packets
3040 Tell a stub about GDB client features, and request remote target features.
3041 The first feature implemented is PacketSize, which allows the target to
3042 specify the size of packets it can handle - to minimize the number of
3043 packets required and improve performance when connected to a remote
3047 Fetch an OS auxilliary vector from the remote stub. This packet is a
3048 more efficient replacement for qPart:auxv:read.
3050 qXfer:memory-map:read:
3051 Fetch a memory map from the remote stub, including information about
3052 RAM, ROM, and flash memory devices.
3057 Erase and program a flash memory device.
3059 * Removed remote packets
3062 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3063 used it, and only gdbserver implemented it.
3065 *** Changes in GDB 6.5
3069 Renesas M32C/M16C m32c-elf
3071 Morpho Technologies ms1 ms1-elf
3075 init-if-undefined Initialize a convenience variable, but
3076 only if it doesn't already have a value.
3078 The following commands are presently only implemented for native GNU/Linux:
3080 checkpoint Save a snapshot of the program state.
3082 restart <n> Return the program state to a
3083 previously saved state.
3085 info checkpoints List currently saved checkpoints.
3087 delete-checkpoint <n> Delete a previously saved checkpoint.
3089 set|show detach-on-fork Tell gdb whether to detach from a newly
3090 forked process, or to keep debugging it.
3092 info forks List forks of the user program that
3093 are available to be debugged.
3095 fork <n> Switch to debugging one of several
3096 forks of the user program that are
3097 available to be debugged.
3099 delete-fork <n> Delete a fork from the list of forks
3100 that are available to be debugged (and
3101 kill the forked process).
3103 detach-fork <n> Delete a fork from the list of forks
3104 that are available to be debugged (and
3105 allow the process to continue).
3109 Morpho Technologies ms2 ms1-elf
3111 * Improved Windows host support
3113 GDB now builds as a cross debugger hosted on i686-mingw32, including
3114 native console support, and remote communications using either
3115 network sockets or serial ports.
3117 * Improved Modula-2 language support
3119 GDB can now print most types in the Modula-2 syntax. This includes:
3120 basic types, set types, record types, enumerated types, range types,
3121 pointer types and ARRAY types. Procedure var parameters are correctly
3122 printed and hexadecimal addresses and character constants are also
3123 written in the Modula-2 syntax. Best results can be obtained by using
3124 GNU Modula-2 together with the -gdwarf-2 command line option.
3128 The ARM rdi-share module.
3130 The Netware NLM debug server.
3132 *** Changes in GDB 6.4
3134 * New native configurations
3136 OpenBSD/arm arm*-*-openbsd*
3137 OpenBSD/mips64 mips64-*-openbsd*
3141 Morpho Technologies ms1 ms1-elf
3143 * New command line options
3145 --batch-silent As for --batch, but totally silent.
3146 --return-child-result The debugger will exist with the same value
3147 the child (debugged) program exited with.
3148 --eval-command COMMAND, -ex COMMAND
3149 Execute a single GDB CLI command. This may be
3150 specified multiple times and in conjunction
3151 with the --command (-x) option.
3153 * Deprecated commands removed
3155 The following commands, that were deprecated in 2000, have been
3159 set|show arm disassembly-flavor set|show arm disassembler
3160 othernames set arm disassembler
3161 set|show remotedebug set|show debug remote
3162 set|show archdebug set|show debug arch
3163 set|show eventdebug set|show debug event
3166 * New BSD user-level threads support
3168 It is now possible to debug programs using the user-level threads
3169 library on OpenBSD and FreeBSD. Currently supported (target)
3172 FreeBSD/amd64 x86_64-*-freebsd*
3173 FreeBSD/i386 i386-*-freebsd*
3174 OpenBSD/i386 i386-*-openbsd*
3176 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3177 are not yet supported.
3179 * New support for Matsushita MN10300 w/sim added
3180 (Work in progress). mn10300-elf.
3182 * REMOVED configurations and files
3184 VxWorks and the XDR protocol *-*-vxworks
3185 Motorola MCORE mcore-*-*
3186 National Semiconductor NS32000 ns32k-*-*
3188 * New "set print array-indexes" command
3190 After turning this setting "on", GDB prints the index of each element
3191 when displaying arrays. The default is "off" to preserve the previous
3194 * VAX floating point support
3196 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3198 * User-defined command support
3200 In addition to using $arg0..$arg9 for argument passing, it is now possible
3201 to use $argc to determine now many arguments have been passed. See the
3202 section on user-defined commands in the user manual for more information.
3204 *** Changes in GDB 6.3:
3206 * New command line option
3208 GDB now accepts -l followed by a number to set the timeout for remote
3211 * GDB works with GCC -feliminate-dwarf2-dups
3213 GDB now supports a more compact representation of DWARF-2 debug
3214 information using DW_FORM_ref_addr references. These are produced
3215 by GCC with the option -feliminate-dwarf2-dups and also by some
3216 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3217 to use -feliminate-dwarf2-dups.
3219 * Internationalization
3221 When supported by the host system, GDB will be built with
3222 internationalization (libintl). The task of marking up the sources is
3223 continued, we're looking forward to our first translation.
3227 Initial support for debugging programs compiled with the GNAT
3228 implementation of the Ada programming language has been integrated
3229 into GDB. In this release, support is limited to expression evaluation.
3231 * New native configurations
3233 GNU/Linux/m32r m32r-*-linux-gnu
3237 GDB's remote protocol now includes support for the 'p' packet. This
3238 packet is used to fetch individual registers from a remote inferior.
3240 * END-OF-LIFE registers[] compatibility module
3242 GDB's internal register infrastructure has been completely rewritten.
3243 The new infrastructure making possible the implementation of key new
3244 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3247 GDB 6.3 will be the last release to include the the registers[]
3248 compatibility module that allowed out-of-date configurations to
3249 continue to work. This change directly impacts the following
3259 powerpc bdm protocol
3261 Unless there is activity to revive these configurations, they will be
3262 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3264 * OBSOLETE configurations and files
3266 Configurations that have been declared obsolete in this release have
3267 been commented out. Unless there is activity to revive these
3268 configurations, the next release of GDB will have their sources
3269 permanently REMOVED.
3278 *** Changes in GDB 6.2.1:
3280 * MIPS `break main; run' gave an heuristic-fence-post warning
3282 When attempting to run even a simple program, a warning about
3283 heuristic-fence-post being hit would be reported. This problem has
3286 * MIPS IRIX 'long double' crashed GDB
3288 When examining a long double variable, GDB would get a segmentation
3289 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3290 IRIX long double values).
3294 A bug in the VAX stack code was causing problems with the "next"
3295 command. This problem has been fixed.
3297 *** Changes in GDB 6.2:
3299 * Fix for ``many threads''
3301 On GNU/Linux systems that use the NPTL threads library, a program
3302 rapidly creating and deleting threads would confuse GDB leading to the
3305 ptrace: No such process.
3306 thread_db_get_info: cannot get thread info: generic error
3308 This problem has been fixed.
3310 * "-async" and "-noasync" options removed.
3312 Support for the broken "-noasync" option has been removed (it caused
3315 * New ``start'' command.
3317 This command runs the program until the begining of the main procedure.
3319 * New BSD Kernel Data Access Library (libkvm) interface
3321 Using ``target kvm'' it is now possible to debug kernel core dumps and
3322 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3323 platforms. Currently supported (native-only) configurations are:
3325 FreeBSD/amd64 x86_64-*-freebsd*
3326 FreeBSD/i386 i?86-*-freebsd*
3327 NetBSD/i386 i?86-*-netbsd*
3328 NetBSD/m68k m68*-*-netbsd*
3329 NetBSD/sparc sparc-*-netbsd*
3330 OpenBSD/amd64 x86_64-*-openbsd*
3331 OpenBSD/i386 i?86-*-openbsd*
3332 OpenBSD/m68k m68*-openbsd*
3333 OpenBSD/sparc sparc-*-openbsd*
3335 * Signal trampoline code overhauled
3337 Many generic problems with GDB's signal handling code have been fixed.
3338 These include: backtraces through non-contiguous stacks; recognition
3339 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3340 call; backtrace through a signal trampoline; step into and out of
3341 signal handlers; and single-stepping in the signal trampoline.
3343 Please note that kernel bugs are a limiting factor here. These
3344 features have been shown to work on an s390 GNU/Linux system that
3345 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3347 * Cygwin support for DWARF 2 added.
3349 * New native configurations
3351 GNU/Linux/hppa hppa*-*-linux*
3352 OpenBSD/hppa hppa*-*-openbsd*
3353 OpenBSD/m68k m68*-*-openbsd*
3354 OpenBSD/m88k m88*-*-openbsd*
3355 OpenBSD/powerpc powerpc-*-openbsd*
3356 NetBSD/vax vax-*-netbsd*
3357 OpenBSD/vax vax-*-openbsd*
3359 * END-OF-LIFE frame compatibility module
3361 GDB's internal frame infrastructure has been completely rewritten.
3362 The new infrastructure making it possible to support key new features
3363 including DWARF 2 Call Frame Information. To aid in the task of
3364 migrating old configurations to this new infrastructure, a
3365 compatibility module, that allowed old configurations to continue to
3366 work, was also included.
3368 GDB 6.2 will be the last release to include this frame compatibility
3369 module. This change directly impacts the following configurations:
3379 Unless there is activity to revive these configurations, they will be
3380 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3382 * REMOVED configurations and files
3384 Sun 3, running SunOS 3 m68*-*-sunos3*
3385 Sun 3, running SunOS 4 m68*-*-sunos4*
3386 Sun 2, running SunOS 3 m68000-*-sunos3*
3387 Sun 2, running SunOS 4 m68000-*-sunos4*
3388 Motorola 680x0 running LynxOS m68*-*-lynxos*
3389 AT&T 3b1/Unix pc m68*-att-*
3390 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3391 decstation mips-dec-* mips-little-*
3392 riscos mips-*-riscos* mips-*-sysv*
3393 sonymips mips-sony-*
3394 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3396 *** Changes in GDB 6.1.1:
3398 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3400 The TUI (Text-mode User Interface) is now built as part of a default
3401 GDB configuration. It is enabled by either selecting the TUI with the
3402 command line option "-i=tui" or by running the separate "gdbtui"
3403 program. For more information on the TUI, see the manual "Debugging
3406 * Pending breakpoint support (also included in GDB 6.1)
3408 Support has been added to allow you to specify breakpoints in shared
3409 libraries that have not yet been loaded. If a breakpoint location
3410 cannot be found, and the "breakpoint pending" option is set to auto,
3411 GDB queries you if you wish to make the breakpoint pending on a future
3412 shared-library load. If and when GDB resolves the breakpoint symbol,
3413 the pending breakpoint is removed as one or more regular breakpoints
3416 Pending breakpoints are very useful for GCJ Java debugging.
3418 * Fixed ISO-C build problems
3420 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3421 non ISO-C code that stopped them being built using a more strict ISO-C
3422 compiler (e.g., IBM's C compiler).
3424 * Fixed build problem on IRIX 5
3426 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3427 wasn't able to compile compile on an IRIX 5 system.
3429 * Added execute permission to gdb/gdbserver/configure
3431 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3432 permission. This bug would cause configure to fail on a number of
3433 systems (Solaris, IRIX). Ref: server/519.
3435 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3437 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3438 has been updated to use constant array sizes.
3440 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3442 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3443 its generated DWARF Call Frame Info. This encoding was causing GDB to
3444 panic, that panic has been fixed. Ref: gdb/1628.
3446 * Fixed a problem when examining parameters in shared library code.
3448 When examining parameters in optimized shared library code generated
3449 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3450 not available''. GDB now correctly displays the variable's value.
3452 *** Changes in GDB 6.1:
3454 * Removed --with-mmalloc
3456 Support for the mmalloc memory manager has been removed, as it
3457 conflicted with the internal gdb byte cache.
3459 * Changes in AMD64 configurations
3461 The AMD64 target now includes the %cs and %ss registers. As a result
3462 the AMD64 remote protocol has changed; this affects the floating-point
3463 and SSE registers. If you rely on those registers for your debugging,
3464 you should upgrade gdbserver on the remote side.
3466 * Revised SPARC target
3468 The SPARC target has been completely revised, incorporating the
3469 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3470 support for LynxOS and SunOS 4 has been dropped. Calling functions
3471 from within GDB on operating systems with a non-executable stack
3472 (Solaris, OpenBSD) now works.
3476 GDB has a new C++ demangler which does a better job on the mangled
3477 names generated by current versions of g++. It also runs faster, so
3478 with this and other changes gdb should now start faster on large C++
3481 * DWARF 2 Location Expressions
3483 GDB support for location expressions has been extended to support function
3484 arguments and frame bases. Older versions of GDB could crash when they
3487 * C++ nested types and namespaces
3489 GDB's support for nested types and namespaces in C++ has been
3490 improved, especially if you use the DWARF 2 debugging format. (This
3491 is the default for recent versions of GCC on most platforms.)
3492 Specifically, if you have a class "Inner" defined within a class or
3493 namespace "Outer", then GDB realizes that the class's name is
3494 "Outer::Inner", not simply "Inner". This should greatly reduce the
3495 frequency of complaints about not finding RTTI symbols. In addition,
3496 if you are stopped at inside of a function defined within a namespace,
3497 GDB modifies its name lookup accordingly.
3499 * New native configurations
3501 NetBSD/amd64 x86_64-*-netbsd*
3502 OpenBSD/amd64 x86_64-*-openbsd*
3503 OpenBSD/alpha alpha*-*-openbsd*
3504 OpenBSD/sparc sparc-*-openbsd*
3505 OpenBSD/sparc64 sparc64-*-openbsd*
3507 * New debugging protocols
3509 M32R with SDI protocol m32r-*-elf*
3511 * "set prompt-escape-char" command deleted.
3513 The command "set prompt-escape-char" has been deleted. This command,
3514 and its very obscure effet on GDB's prompt, was never documented,
3515 tested, nor mentioned in the NEWS file.
3517 * OBSOLETE configurations and files
3519 Configurations that have been declared obsolete in this release have
3520 been commented out. Unless there is activity to revive these
3521 configurations, the next release of GDB will have their sources
3522 permanently REMOVED.
3524 Sun 3, running SunOS 3 m68*-*-sunos3*
3525 Sun 3, running SunOS 4 m68*-*-sunos4*
3526 Sun 2, running SunOS 3 m68000-*-sunos3*
3527 Sun 2, running SunOS 4 m68000-*-sunos4*
3528 Motorola 680x0 running LynxOS m68*-*-lynxos*
3529 AT&T 3b1/Unix pc m68*-att-*
3530 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3531 decstation mips-dec-* mips-little-*
3532 riscos mips-*-riscos* mips-*-sysv*
3533 sonymips mips-sony-*
3534 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3536 * REMOVED configurations and files
3538 SGI Irix-4.x mips-sgi-irix4 or iris4
3539 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3540 Z8000 simulator z8k-zilog-none or z8ksim
3541 Matsushita MN10200 w/simulator mn10200-*-*
3542 H8/500 simulator h8500-hitachi-hms or h8500hms
3543 HP/PA running BSD hppa*-*-bsd*
3544 HP/PA running OSF/1 hppa*-*-osf*
3545 HP/PA Pro target hppa*-*-pro*
3546 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3547 386BSD i[3456]86-*-bsd*
3548 Sequent family i[3456]86-sequent-sysv4*
3549 i[3456]86-sequent-sysv*
3550 i[3456]86-sequent-bsd*
3551 SPARC running LynxOS sparc-*-lynxos*
3552 SPARC running SunOS 4 sparc-*-sunos4*
3553 Tsqware Sparclet sparclet-*-*
3554 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3556 *** Changes in GDB 6.0:
3560 Support for debugging the Objective-C programming language has been
3561 integrated into GDB.
3563 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3565 DWARF 2's Call Frame Information makes available compiler generated
3566 information that more exactly describes the program's run-time stack.
3567 By using this information, GDB is able to provide more robust stack
3570 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3571 have been updated to use a new backtrace mechanism which includes
3572 DWARF 2 CFI support.
3576 GDB's remote protocol has been extended to include support for hosted
3577 file I/O (where the remote target uses GDB's file system). See GDB's
3578 remote protocol documentation for details.
3580 * All targets using the new architecture framework.
3582 All of GDB's targets have been updated to use the new internal
3583 architecture framework. The way is now open for future GDB releases
3584 to include cross-architecture native debugging support (i386 on amd64,
3587 * GNU/Linux's Thread Local Storage (TLS)
3589 GDB now includes support for for the GNU/Linux implementation of
3590 per-thread variables.
3592 * GNU/Linux's Native POSIX Thread Library (NPTL)
3594 GDB's thread code has been updated to work with either the new
3595 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3597 * Separate debug info.
3599 GDB, in conjunction with BINUTILS, now supports a mechanism for
3600 automatically loading debug information from a separate file. Instead
3601 of shipping full debug and non-debug versions of system libraries,
3602 system integrators can now instead ship just the stripped libraries
3603 and optional debug files.
3605 * DWARF 2 Location Expressions
3607 DWARF 2 Location Expressions allow the compiler to more completely
3608 describe the location of variables (even in optimized code) to the
3611 GDB now includes preliminary support for location expressions (support
3612 for DW_OP_piece is still missing).
3616 A number of long standing bugs that caused GDB to die while starting a
3617 Java application have been fixed. GDB's Java support is now
3618 considered "useable".
3620 * GNU/Linux support for fork, vfork, and exec.
3622 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3623 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3626 * GDB supports logging output to a file
3628 There are two new commands, "set logging" and "show logging", which can be
3629 used to capture GDB's output to a file.
3631 * The meaning of "detach" has changed for gdbserver
3633 The "detach" command will now resume the application, as documented. To
3634 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3637 * d10v, m68hc11 `regs' command deprecated
3639 The `info registers' command has been updated so that it displays the
3640 registers using a format identical to the old `regs' command.
3644 A new command, "maint set profile on/off", has been added. This command can
3645 be used to enable or disable profiling while running GDB, to profile a
3646 session or a set of commands. In addition there is a new configure switch,
3647 "--enable-profiling", which will cause GDB to be compiled with profiling
3648 data, for more informative profiling results.
3650 * Default MI syntax changed to "mi2".
3652 The default MI (machine interface) syntax, enabled by the command line
3653 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3654 "mi1", can be enabled by specifying the option "-i=mi1".
3656 Support for the original "mi0" syntax (included in GDB 5.0) has been
3659 Fix for gdb/192: removed extraneous space when displaying frame level.
3660 Fix for gdb/672: update changelist is now output in mi list format.
3661 Fix for gdb/702: a -var-assign that updates the value now shows up
3662 in a subsequent -var-update.
3664 * New native configurations.
3666 FreeBSD/amd64 x86_64-*-freebsd*
3668 * Multi-arched targets.
3670 HP/PA HPUX11 hppa*-*-hpux*
3671 Renesas M32R/D w/simulator m32r-*-elf*
3673 * OBSOLETE configurations and files
3675 Configurations that have been declared obsolete in this release have
3676 been commented out. Unless there is activity to revive these
3677 configurations, the next release of GDB will have their sources
3678 permanently REMOVED.
3680 Z8000 simulator z8k-zilog-none or z8ksim
3681 Matsushita MN10200 w/simulator mn10200-*-*
3682 H8/500 simulator h8500-hitachi-hms or h8500hms
3683 HP/PA running BSD hppa*-*-bsd*
3684 HP/PA running OSF/1 hppa*-*-osf*
3685 HP/PA Pro target hppa*-*-pro*
3686 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3687 Sequent family i[3456]86-sequent-sysv4*
3688 i[3456]86-sequent-sysv*
3689 i[3456]86-sequent-bsd*
3690 Tsqware Sparclet sparclet-*-*
3691 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3693 * REMOVED configurations and files
3696 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3697 IBM AIX PS/2 i[3456]86-*-aix
3698 i386 running Mach 3.0 i[3456]86-*-mach3*
3699 i386 running Mach i[3456]86-*-mach*
3700 i386 running OSF/1 i[3456]86-*osf1mk*
3701 HP/Apollo 68k Family m68*-apollo*-sysv*,
3703 m68*-hp-bsd*, m68*-hp-hpux*
3704 Argonaut Risc Chip (ARC) arc-*-*
3705 Mitsubishi D30V d30v-*-*
3706 Fujitsu FR30 fr30-*-elf*
3707 OS/9000 i[34]86-*-os9k
3708 I960 with MON960 i960-*-coff
3710 * MIPS $fp behavior changed
3712 The convenience variable $fp, for the MIPS, now consistently returns
3713 the address of the current frame's base. Previously, depending on the
3714 context, $fp could refer to either $sp or the current frame's base
3715 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3716 The GNU Source-Level Debugger''.
3718 *** Changes in GDB 5.3:
3720 * GNU/Linux shared library multi-threaded performance improved.
3722 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3723 `/proc', in preference to `ptrace' for memory reads. This may result
3724 in an improvement in the start-up time of multi-threaded, shared
3725 library applications when run under GDB. One GDB user writes: ``loads
3726 shared libs like mad''.
3728 * ``gdbserver'' now supports multi-threaded applications on some targets
3730 Support for debugging multi-threaded applications which use
3731 the GNU/Linux LinuxThreads package has been added for
3732 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3733 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3735 * GDB now supports C/C++ preprocessor macros.
3737 GDB now expands preprocessor macro invocations in C/C++ expressions,
3738 and provides various commands for showing macro definitions and how
3741 The new command `macro expand EXPRESSION' expands any macro
3742 invocations in expression, and shows the result.
3744 The new command `show macro MACRO-NAME' shows the definition of the
3745 macro named MACRO-NAME, and where it was defined.
3747 Most compilers don't include information about macros in the debugging
3748 information by default. In GCC 3.1, for example, you need to compile
3749 your program with the options `-gdwarf-2 -g3'. If the macro
3750 information is present in the executable, GDB will read it.
3752 * Multi-arched targets.
3754 DEC Alpha (partial) alpha*-*-*
3755 DEC VAX (partial) vax-*-*
3757 National Semiconductor NS32000 (partial) ns32k-*-*
3758 Motorola 68000 (partial) m68k-*-*
3759 Motorola MCORE mcore-*-*
3763 Fujitsu FRV architecture added by Red Hat frv*-*-*
3766 * New native configurations
3768 Alpha NetBSD alpha*-*-netbsd*
3769 SH NetBSD sh*-*-netbsdelf*
3770 MIPS NetBSD mips*-*-netbsd*
3771 UltraSPARC NetBSD sparc64-*-netbsd*
3773 * OBSOLETE configurations and files
3775 Configurations that have been declared obsolete in this release have
3776 been commented out. Unless there is activity to revive these
3777 configurations, the next release of GDB will have their sources
3778 permanently REMOVED.
3780 Mitsubishi D30V d30v-*-*
3781 OS/9000 i[34]86-*-os9k
3782 IBM AIX PS/2 i[3456]86-*-aix
3783 Fujitsu FR30 fr30-*-elf*
3784 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3785 Argonaut Risc Chip (ARC) arc-*-*
3786 i386 running Mach 3.0 i[3456]86-*-mach3*
3787 i386 running Mach i[3456]86-*-mach*
3788 i386 running OSF/1 i[3456]86-*osf1mk*
3789 HP/Apollo 68k Family m68*-apollo*-sysv*,
3791 m68*-hp-bsd*, m68*-hp-hpux*
3792 I960 with MON960 i960-*-coff
3794 * OBSOLETE languages
3796 CHILL, a Pascal like language used by telecommunications companies.
3798 * REMOVED configurations and files
3800 AMD 29k family via UDI a29k-amd-udi, udi29k
3801 A29K VxWorks a29k-*-vxworks
3802 AMD 29000 embedded, using EBMON a29k-none-none
3803 AMD 29000 embedded with COFF a29k-none-coff
3804 AMD 29000 embedded with a.out a29k-none-aout
3806 testsuite/gdb.hp/gdb.threads-hp/ directory
3808 * New command "set max-user-call-depth <nnn>"
3810 This command allows the user to limit the call depth of user-defined
3811 commands. The default is 1024.
3813 * Changes in FreeBSD/i386 native debugging.
3815 Support for the "generate-core-file" has been added.
3817 * New commands "dump", "append", and "restore".
3819 These commands allow data to be copied from target memory
3820 to a bfd-format or binary file (dump and append), and back
3821 from a file into memory (restore).
3823 * Improved "next/step" support on multi-processor Alpha Tru64.
3825 The previous single-step mechanism could cause unpredictable problems,
3826 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3827 of a software single-step mechanism prevents this.
3829 *** Changes in GDB 5.2.1:
3837 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3838 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3839 Fix, by Joel Brobecker imported from mainline.
3841 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3842 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3843 Fix, by Fred Fish, imported from mainline.
3845 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3846 Surprisingly enough, it works now.
3847 By Michal Ludvig, imported from mainline.
3849 i386 hardware watchpoint support:
3850 avoid misses on second run for some targets.
3851 By Pierre Muller, imported from mainline.
3853 *** Changes in GDB 5.2:
3855 * New command "set trust-readonly-sections on[off]".
3857 This command is a hint that tells gdb that read-only sections
3858 really are read-only (ie. that their contents will not change).
3859 In this mode, gdb will go to the object file rather than the
3860 target to read memory from read-only sections (such as ".text").
3861 This can be a significant performance improvement on some
3862 (notably embedded) targets.
3864 * New command "generate-core-file" (or "gcore").
3866 This new gdb command allows the user to drop a core file of the child
3867 process state at any time. So far it's been implemented only for
3868 GNU/Linux and Solaris, but should be relatively easily ported to other
3869 hosts. Argument is core file name (defaults to core.<pid>).
3871 * New command line option
3873 GDB now accepts --pid or -p followed by a process id.
3875 * Change in command line behavior -- corefiles vs. process ids.
3877 There is a subtle behavior in the way in which GDB handles
3878 command line arguments. The first non-flag argument is always
3879 a program to debug, but the second non-flag argument may either
3880 be a corefile or a process id. Previously, GDB would attempt to
3881 open the second argument as a corefile, and if that failed, would
3882 issue a superfluous error message and then attempt to attach it as
3883 a process. Now, if the second argument begins with a non-digit,
3884 it will be treated as a corefile. If it begins with a digit,
3885 GDB will attempt to attach it as a process, and if no such process
3886 is found, will then attempt to open it as a corefile.
3888 * Changes in ARM configurations.
3890 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3891 configuration is fully multi-arch.
3893 * New native configurations
3895 ARM NetBSD arm*-*-netbsd*
3896 x86 OpenBSD i[3456]86-*-openbsd*
3897 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3898 Sparc64 running FreeBSD sparc64-*-freebsd*
3902 Sanyo XStormy16 xstormy16-elf
3904 * OBSOLETE configurations and files
3906 Configurations that have been declared obsolete in this release have
3907 been commented out. Unless there is activity to revive these
3908 configurations, the next release of GDB will have their sources
3909 permanently REMOVED.
3911 AMD 29k family via UDI a29k-amd-udi, udi29k
3912 A29K VxWorks a29k-*-vxworks
3913 AMD 29000 embedded, using EBMON a29k-none-none
3914 AMD 29000 embedded with COFF a29k-none-coff
3915 AMD 29000 embedded with a.out a29k-none-aout
3917 testsuite/gdb.hp/gdb.threads-hp/ directory
3919 * REMOVED configurations and files
3921 TI TMS320C80 tic80-*-*
3923 PowerPC Solaris powerpcle-*-solaris*
3924 PowerPC Windows NT powerpcle-*-cygwin32
3925 PowerPC Netware powerpc-*-netware*
3926 Harris/CXUX m88k m88*-harris-cxux*
3927 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3928 ns32k-utek-sysv* ns32k-utek-*
3929 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3930 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3931 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3932 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3933 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3935 * Changes to command line processing
3937 The new `--args' feature can be used to specify command-line arguments
3938 for the inferior from gdb's command line.
3940 * Changes to key bindings
3942 There is a new `operate-and-get-next' function bound to `C-o'.
3944 *** Changes in GDB 5.1.1
3946 Fix compile problem on DJGPP.
3948 Fix a problem with floating-point registers on the i386 being
3951 Fix to stop GDB crashing on .debug_str debug info.
3953 Numerous documentation fixes.
3955 Numerous testsuite fixes.
3957 *** Changes in GDB 5.1:
3959 * New native configurations
3961 Alpha FreeBSD alpha*-*-freebsd*
3962 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3963 MIPS GNU/Linux mips*-*-linux*
3964 MIPS SGI Irix 6.x mips*-sgi-irix6*
3965 ia64 AIX ia64-*-aix*
3966 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3970 Motorola 68HC11 and 68HC12 m68hc11-elf
3972 UltraSparc running GNU/Linux sparc64-*-linux*
3974 * OBSOLETE configurations and files
3976 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3977 Harris/CXUX m88k m88*-harris-cxux*
3978 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3979 ns32k-utek-sysv* ns32k-utek-*
3980 TI TMS320C80 tic80-*-*
3982 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3983 PowerPC Solaris powerpcle-*-solaris*
3984 PowerPC Windows NT powerpcle-*-cygwin32
3985 PowerPC Netware powerpc-*-netware*
3986 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3987 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3988 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3989 Apple Macintosh (MPW) host N/A
3991 stuff.c (Program to stuff files into a specially prepared space in kdb)
3992 kdb-start.c (Main loop for the standalone kernel debugger)
3994 Configurations that have been declared obsolete in this release have
3995 been commented out. Unless there is activity to revive these
3996 configurations, the next release of GDB will have their sources
3997 permanently REMOVED.
3999 * REMOVED configurations and files
4001 Altos 3068 m68*-altos-*
4002 Convex c1-*-*, c2-*-*
4004 ARM RISCix arm-*-* (as host)
4008 * GDB has been converted to ISO C.
4010 GDB's source code has been converted to ISO C. In particular, the
4011 sources are fully protoized, and rely on standard headers being
4016 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4018 * The MI enabled by default.
4020 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4021 revised and enabled by default. Packages which use GDB as a debugging
4022 engine behind a UI or another front end are encouraged to switch to
4023 using the GDB/MI interface, instead of the old annotations interface
4024 which is now deprecated.
4026 * Support for debugging Pascal programs.
4028 GDB now includes support for debugging Pascal programs. The following
4029 main features are supported:
4031 - Pascal-specific data types such as sets;
4033 - automatic recognition of Pascal sources based on file-name
4036 - Pascal-style display of data types, variables, and functions;
4038 - a Pascal expression parser.
4040 However, some important features are not yet supported.
4042 - Pascal string operations are not supported at all;
4044 - there are some problems with boolean types;
4046 - Pascal type hexadecimal constants are not supported
4047 because they conflict with the internal variables format;
4049 - support for Pascal objects and classes is not full yet;
4051 - unlike Pascal, GDB is case-sensitive for symbol names.
4053 * Changes in completion.
4055 Commands such as `shell', `run' and `set args', which pass arguments
4056 to inferior programs, now complete on file names, similar to what
4057 users expect at the shell prompt.
4059 Commands which accept locations, such as `disassemble', `print',
4060 `breakpoint', `until', etc. now complete on filenames as well as
4061 program symbols. Thus, if you type "break foob TAB", and the source
4062 files linked into the programs include `foobar.c', that file name will
4063 be one of the candidates for completion. However, file names are not
4064 considered for completion after you typed a colon that delimits a file
4065 name from a name of a function in that file, as in "break foo.c:bar".
4067 `set demangle-style' completes on available demangling styles.
4069 * New platform-independent commands:
4071 It is now possible to define a post-hook for a command as well as a
4072 hook that runs before the command. For more details, see the
4073 documentation of `hookpost' in the GDB manual.
4075 * Changes in GNU/Linux native debugging.
4077 Support for debugging multi-threaded programs has been completely
4078 revised for all platforms except m68k and sparc. You can now debug as
4079 many threads as your system allows you to have.
4081 Attach/detach is supported for multi-threaded programs.
4083 Support for SSE registers was added for x86. This doesn't work for
4084 multi-threaded programs though.
4086 * Changes in MIPS configurations.
4088 Multi-arch support is enabled for all MIPS configurations.
4090 GDB can now be built as native debugger on SGI Irix 6.x systems for
4091 debugging n32 executables. (Debugging 64-bit executables is not yet
4094 * Unified support for hardware watchpoints in all x86 configurations.
4096 Most (if not all) native x86 configurations support hardware-assisted
4097 breakpoints and watchpoints in a unified manner. This support
4098 implements debug register sharing between watchpoints, which allows to
4099 put a virtually infinite number of watchpoints on the same address,
4100 and also supports watching regions up to 16 bytes with several debug
4103 The new maintenance command `maintenance show-debug-regs' toggles
4104 debugging print-outs in functions that insert, remove, and test
4105 watchpoints and hardware breakpoints.
4107 * Changes in the DJGPP native configuration.
4109 New command ``info dos sysinfo'' displays assorted information about
4110 the CPU, OS, memory, and DPMI server.
4112 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4113 display information about segment descriptors stored in GDT, LDT, and
4116 New commands ``info dos pde'' and ``info dos pte'' display entries
4117 from Page Directory and Page Tables (for now works with CWSDPMI only).
4118 New command ``info dos address-pte'' displays the Page Table entry for
4119 a given linear address.
4121 GDB can now pass command lines longer than 126 characters to the
4122 program being debugged (requires an update to the libdbg.a library
4123 which is part of the DJGPP development kit).
4125 DWARF2 debug info is now supported.
4127 It is now possible to `step' and `next' through calls to `longjmp'.
4129 * Changes in documentation.
4131 All GDB documentation was converted to GFDL, the GNU Free
4132 Documentation License.
4134 Tracepoints-related commands are now fully documented in the GDB
4137 TUI, the Text-mode User Interface, is now documented in the manual.
4139 Tracepoints-related commands are now fully documented in the GDB
4142 The "GDB Internals" manual now has an index. It also includes
4143 documentation of `ui_out' functions, GDB coding standards, x86
4144 hardware watchpoints, and memory region attributes.
4146 * GDB's version number moved to ``version.in''
4148 The Makefile variable VERSION has been replaced by the file
4149 ``version.in''. People creating GDB distributions should update the
4150 contents of this file.
4154 GUD support is now a standard part of the EMACS distribution.
4156 *** Changes in GDB 5.0:
4158 * Improved support for debugging FP programs on x86 targets
4160 Unified and much-improved support for debugging floating-point
4161 programs on all x86 targets. In particular, ``info float'' now
4162 displays the FP registers in the same format on all x86 targets, with
4163 greater level of detail.
4165 * Improvements and bugfixes in hardware-assisted watchpoints
4167 It is now possible to watch array elements, struct members, and
4168 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4169 on x86 targets no longer erroneously trigger when the address is
4172 * Improvements in the native DJGPP version of GDB
4174 The distribution now includes all the scripts and auxiliary files
4175 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4176 machines ``out of the box''.
4178 The DJGPP version can now debug programs that use signals. It is
4179 possible to catch signals that happened in the debuggee, deliver
4180 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4181 would kill the program being debugged.) Programs that hook hardware
4182 interrupts (keyboard, timer, etc.) can also be debugged.
4184 It is now possible to debug DJGPP programs that redirect their
4185 standard handles or switch them to raw (as opposed to cooked) mode, or
4186 even close them. The command ``run < foo > bar'' works as expected,
4187 and ``info terminal'' reports useful information about the debuggee's
4188 terminal, including raw/cooked mode, redirection, etc.
4190 The DJGPP version now uses termios functions for console I/O, which
4191 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4194 DOS-style file names with drive letters are now fully supported by
4197 It is now possible to debug DJGPP programs that switch their working
4198 directory. It is also possible to rerun the debuggee any number of
4199 times without restarting GDB; thus, you can use the same setup,
4200 breakpoints, etc. for many debugging sessions.
4202 * New native configurations
4204 ARM GNU/Linux arm*-*-linux*
4205 PowerPC GNU/Linux powerpc-*-linux*
4209 Motorola MCore mcore-*-*
4210 x86 VxWorks i[3456]86-*-vxworks*
4211 PowerPC VxWorks powerpc-*-vxworks*
4212 TI TMS320C80 tic80-*-*
4214 * OBSOLETE configurations
4216 Altos 3068 m68*-altos-*
4217 Convex c1-*-*, c2-*-*
4219 ARM RISCix arm-*-* (as host)
4222 Configurations that have been declared obsolete will be commented out,
4223 but the code will be left in place. If there is no activity to revive
4224 these configurations before the next release of GDB, the sources will
4225 be permanently REMOVED.
4227 * Gould support removed
4229 Support for the Gould PowerNode and NP1 has been removed.
4231 * New features for SVR4
4233 On SVR4 native platforms (such as Solaris), if you attach to a process
4234 without first loading a symbol file, GDB will now attempt to locate and
4235 load symbols from the running process's executable file.
4237 * Many C++ enhancements
4239 C++ support has been greatly improved. Overload resolution now works properly
4240 in almost all cases. RTTI support is on the way.
4242 * Remote targets can connect to a sub-program
4244 A popen(3) style serial-device has been added. This device starts a
4245 sub-process (such as a stand-alone simulator) and then communicates
4246 with that. The sub-program to run is specified using the syntax
4247 ``|<program> <args>'' vis:
4249 (gdb) set remotedebug 1
4250 (gdb) target extended-remote |mn10300-elf-sim program-args
4252 * MIPS 64 remote protocol
4254 A long standing bug in the mips64 remote protocol where by GDB
4255 expected certain 32 bit registers (ex SR) to be transfered as 32
4256 instead of 64 bits has been fixed.
4258 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4259 added to provide backward compatibility with older versions of GDB.
4261 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4263 The command ``set remotebinarydownload'' command has been replaced by
4264 ``set remote X-packet''. Other commands in ``set remote'' family
4265 include ``set remote P-packet''.
4267 * Breakpoint commands accept ranges.
4269 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4270 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4271 ``tracepoint passcount'' also accepts a range of tracepoints.
4273 * ``apropos'' command added.
4275 The ``apropos'' command searches through command names and
4276 documentation strings, printing out matches, making it much easier to
4277 try to find a command that does what you are looking for.
4281 A new machine oriented interface (MI) has been added to GDB. This
4282 interface is designed for debug environments running GDB as a separate
4283 process. This is part of the long term libGDB project. See the
4284 "GDB/MI" chapter of the GDB manual for further information. It can be
4285 enabled by configuring with:
4287 .../configure --enable-gdbmi
4289 *** Changes in GDB-4.18:
4291 * New native configurations
4293 HP-UX 10.20 hppa*-*-hpux10.20
4294 HP-UX 11.x hppa*-*-hpux11.0*
4295 M68K GNU/Linux m68*-*-linux*
4299 Fujitsu FR30 fr30-*-elf*
4300 Intel StrongARM strongarm-*-*
4301 Mitsubishi D30V d30v-*-*
4303 * OBSOLETE configurations
4305 Gould PowerNode, NP1 np1-*-*, pn-*-*
4307 Configurations that have been declared obsolete will be commented out,
4308 but the code will be left in place. If there is no activity to revive
4309 these configurations before the next release of GDB, the sources will
4310 be permanently REMOVED.
4314 As a compatibility experiment, GDB's source files buildsym.h and
4315 buildsym.c have been converted to pure standard C, no longer
4316 containing any K&R compatibility code. We believe that all systems in
4317 use today either come with a standard C compiler, or have a GCC port
4318 available. If this is not true, please report the affected
4319 configuration to bug-gdb@gnu.org immediately. See the README file for
4320 information about getting a standard C compiler if you don't have one
4325 GDB now uses readline 2.2.
4327 * set extension-language
4329 You can now control the mapping between filename extensions and source
4330 languages by using the `set extension-language' command. For instance,
4331 you can ask GDB to treat .c files as C++ by saying
4332 set extension-language .c c++
4333 The command `info extensions' lists all of the recognized extensions
4334 and their associated languages.
4336 * Setting processor type for PowerPC and RS/6000
4338 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4339 you can use the `set processor' command to specify what variant of the
4340 PowerPC family you are debugging. The command
4344 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4345 following PowerPC and RS6000 variants:
4347 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4348 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4350 403GC IBM PowerPC 403GC
4351 505 Motorola PowerPC 505
4352 860 Motorola PowerPC 860 or 850
4353 601 Motorola PowerPC 601
4354 602 Motorola PowerPC 602
4355 603 Motorola/IBM PowerPC 603 or 603e
4356 604 Motorola PowerPC 604 or 604e
4357 750 Motorola/IBM PowerPC 750 or 750
4359 At the moment, this command just tells GDB what to name the
4360 special-purpose processor registers. Since almost all the affected
4361 registers are inaccessible to user-level programs, this command is
4362 only useful for remote debugging in its present form.
4366 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4367 more extensive support for HP-UX. Added features include shared
4368 library support, kernel threads and hardware watchpoints for 11.00,
4369 support for HP's ANSI C and C++ compilers, and a compatibility mode
4370 for xdb and dbx commands.
4374 HP's donation includes the new concept of catchpoints, which is a
4375 generalization of the old catch command. On HP-UX, it is now possible
4376 to catch exec, fork, and vfork, as well as library loading.
4378 This means that the existing catch command has changed; its first
4379 argument now specifies the type of catch to be set up. See the
4380 output of "help catch" for a list of catchpoint types.
4382 * Debugging across forks
4384 On HP-UX, you can choose which process to debug when a fork() happens
4389 HP has donated a curses-based terminal user interface (TUI). To get
4390 it, build with --enable-tui. Although this can be enabled for any
4391 configuration, at present it only works for native HP debugging.
4393 * GDB remote protocol additions
4395 A new protocol packet 'X' that writes binary data is now available.
4396 Default behavior is to try 'X', then drop back to 'M' if the stub
4397 fails to respond. The settable variable `remotebinarydownload'
4398 allows explicit control over the use of 'X'.
4400 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4401 full 64-bit address. The command
4403 set remoteaddresssize 32
4405 can be used to revert to the old behaviour. For existing remote stubs
4406 the change should not be noticed, as the additional address information
4409 In order to assist in debugging stubs, you may use the maintenance
4410 command `packet' to send any text string to the stub. For instance,
4412 maint packet heythere
4414 sends the packet "$heythere#<checksum>". Note that it is very easy to
4415 disrupt a debugging session by sending the wrong packet at the wrong
4418 The compare-sections command allows you to compare section data on the
4419 target to what is in the executable file without uploading or
4420 downloading, by comparing CRC checksums.
4422 * Tracing can collect general expressions
4424 You may now collect general expressions at tracepoints. This requires
4425 further additions to the target-side stub; see tracepoint.c and
4426 doc/agentexpr.texi for further details.
4428 * mask-address variable for Mips
4430 For Mips targets, you may control the zeroing of the upper 32 bits of
4431 a 64-bit address by entering `set mask-address on'. This is mainly
4432 of interest to users of embedded R4xxx and R5xxx processors.
4434 * Higher serial baud rates
4436 GDB's serial code now allows you to specify baud rates 57600, 115200,
4437 230400, and 460800 baud. (Note that your host system may not be able
4438 to achieve all of these rates.)
4442 The i960 configuration now includes an initial implementation of a
4443 builtin simulator, contributed by Jim Wilson.
4446 *** Changes in GDB-4.17:
4448 * New native configurations
4450 Alpha GNU/Linux alpha*-*-linux*
4451 Unixware 2.x i[3456]86-unixware2*
4452 Irix 6.x mips*-sgi-irix6*
4453 PowerPC GNU/Linux powerpc-*-linux*
4454 PowerPC Solaris powerpcle-*-solaris*
4455 Sparc GNU/Linux sparc-*-linux*
4456 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4460 Argonaut Risc Chip (ARC) arc-*-*
4461 Hitachi H8/300S h8300*-*-*
4462 Matsushita MN10200 w/simulator mn10200-*-*
4463 Matsushita MN10300 w/simulator mn10300-*-*
4464 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4465 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4466 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4467 Mitsubishi D10V w/simulator d10v-*-*
4468 Mitsubishi M32R/D w/simulator m32r-*-elf*
4469 Tsqware Sparclet sparclet-*-*
4470 NEC V850 w/simulator v850-*-*
4472 * New debugging protocols
4474 ARM with RDI protocol arm*-*-*
4475 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4476 DDB and LSI variants of PMON protocol mips*-*-*
4477 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4478 PowerPC with SDS protocol powerpc{,le}-*-eabi
4479 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4483 All configurations can now understand and use the DWARF 2 debugging
4484 format. The choice is automatic, if the symbol file contains DWARF 2
4489 GDB now includes basic Java language support. This support is
4490 only useful with Java compilers that produce native machine code.
4492 * solib-absolute-prefix and solib-search-path
4494 For SunOS and SVR4 shared libraries, you may now set the prefix for
4495 loading absolute shared library symbol files, and the search path for
4496 locating non-absolute shared library symbol files.
4498 * Live range splitting
4500 GDB can now effectively debug code for which GCC has performed live
4501 range splitting as part of its optimization. See gdb/doc/LRS for
4502 more details on the expected format of the stabs information.
4506 GDB's support for the GNU Hurd, including thread debugging, has been
4507 updated to work with current versions of the Hurd.
4511 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4512 instruction set. ARM GDB automatically detects when Thumb
4513 instructions are in use, and adjusts disassembly and backtracing
4518 GDB's MIPS target configurations now handle the MIP16 16-bit
4523 GDB now includes support for overlays; if an executable has been
4524 linked such that multiple sections are based at the same address, GDB
4525 will decide which section to use for symbolic info. You can choose to
4526 control the decision manually, using overlay commands, or implement
4527 additional target-side support and use "overlay load-target" to bring
4528 in the overlay mapping. Do "help overlay" for more detail.
4532 The command "info symbol <address>" displays information about
4533 the symbol at the specified address.
4537 The standard remote protocol now includes an extension that allows
4538 asynchronous collection and display of trace data. This requires
4539 extensive support in the target-side debugging stub. Tracing mode
4540 includes a new interaction mode in GDB and new commands: see the
4541 file tracepoint.c for more details.
4545 Configurations for embedded MIPS now include a simulator contributed
4546 by Cygnus Solutions. The simulator supports the instruction sets
4547 of most MIPS variants.
4551 Sparc configurations may now include the ERC32 simulator contributed
4552 by the European Space Agency. The simulator is not built into
4553 Sparc targets by default; configure with --enable-sim to include it.
4557 For target configurations that may include multiple variants of a
4558 basic architecture (such as MIPS and SH), you may now set the
4559 architecture explicitly. "set arch" sets, "info arch" lists
4560 the possible architectures.
4562 *** Changes in GDB-4.16:
4564 * New native configurations
4566 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4567 M68K NetBSD m68k-*-netbsd*
4568 PowerPC AIX 4.x powerpc-*-aix*
4569 PowerPC MacOS powerpc-*-macos*
4570 PowerPC Windows NT powerpcle-*-cygwin32
4571 RS/6000 AIX 4.x rs6000-*-aix4*
4575 ARM with RDP protocol arm-*-*
4576 I960 with MON960 i960-*-coff
4577 MIPS VxWorks mips*-*-vxworks*
4578 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4579 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4581 Matra Sparclet sparclet-*-*
4585 The powerpc-eabi configuration now includes the PSIM simulator,
4586 contributed by Andrew Cagney, with assistance from Mike Meissner.
4587 PSIM is a very elaborate model of the PowerPC, including not only
4588 basic instruction set execution, but also details of execution unit
4589 performance and I/O hardware. See sim/ppc/README for more details.
4593 GDB now works with Solaris 2.5.
4595 * Windows 95/NT native
4597 GDB will now work as a native debugger on Windows 95 and Windows NT.
4598 To build it from source, you must use the "gnu-win32" environment,
4599 which uses a DLL to emulate enough of Unix to run the GNU tools.
4600 Further information, binaries, and sources are available at
4601 ftp.cygnus.com, under pub/gnu-win32.
4603 * dont-repeat command
4605 If a user-defined command includes the command `dont-repeat', then the
4606 command will not be repeated if the user just types return. This is
4607 useful if the command is time-consuming to run, so that accidental
4608 extra keystrokes don't run the same command many times.
4610 * Send break instead of ^C
4612 The standard remote protocol now includes an option to send a break
4613 rather than a ^C to the target in order to interrupt it. By default,
4614 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4616 * Remote protocol timeout
4618 The standard remote protocol includes a new variable `remotetimeout'
4619 that allows you to set the number of seconds before GDB gives up trying
4620 to read from the target. The default value is 2.
4622 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4624 By default GDB will automatically keep track of objects as they are
4625 loaded and unloaded by the dynamic linker. By using the command `set
4626 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4627 when shared library events occur, thus allowing you to set breakpoints
4628 in shared libraries which are explicitly loaded by the inferior.
4630 Note this feature does not work on hpux8. On hpux9 you must link
4631 /usr/lib/end.o into your program. This feature should work
4632 automatically on hpux10.
4634 * Irix 5.x hardware watchpoint support
4636 Irix 5 configurations now support the use of hardware watchpoints.
4638 * Mips protocol "SYN garbage limit"
4640 When debugging a Mips target using the `target mips' protocol, you
4641 may set the number of characters that GDB will ignore by setting
4642 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4643 every character. The default value is 1050.
4645 * Recording and replaying remote debug sessions
4647 If you set `remotelogfile' to the name of a file, gdb will write to it
4648 a recording of a remote debug session. This recording may then be
4649 replayed back to gdb using "gdbreplay". See gdbserver/README for
4650 details. This is useful when you have a problem with GDB while doing
4651 remote debugging; you can make a recording of the session and send it
4652 to someone else, who can then recreate the problem.
4654 * Speedups for remote debugging
4656 GDB includes speedups for downloading and stepping MIPS systems using
4657 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4658 and more efficient S-record downloading.
4660 * Memory use reductions and statistics collection
4662 GDB now uses less memory and reports statistics about memory usage.
4663 Try the `maint print statistics' command, for example.
4665 *** Changes in GDB-4.15:
4667 * Psymtabs for XCOFF
4669 The symbol reader for AIX GDB now uses partial symbol tables. This
4670 can greatly improve startup time, especially for large executables.
4672 * Remote targets use caching
4674 Remote targets now use a data cache to speed up communication with the
4675 remote side. The data cache could lead to incorrect results because
4676 it doesn't know about volatile variables, thus making it impossible to
4677 debug targets which use memory mapped I/O devices. `set remotecache
4678 off' turns the the data cache off.
4680 * Remote targets may have threads
4682 The standard remote protocol now includes support for multiple threads
4683 in the target system, using new protocol commands 'H' and 'T'. See
4684 gdb/remote.c for details.
4688 If GDB is configured with `--enable-netrom', then it will include
4689 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4690 acts as though it is a bank of ROM on the target board, but you can
4691 write into it over the network. GDB's support consists only of
4692 support for fast loading into the emulated ROM; to debug, you must use
4693 another protocol, such as standard remote protocol. The usual
4694 sequence is something like
4696 target nrom <netrom-hostname>
4698 target remote <netrom-hostname>:1235
4702 GDB now includes support for the Apple Macintosh, as a host only. It
4703 may be run as either an MPW tool or as a standalone application, and
4704 it can debug through the serial port. All the usual GDB commands are
4705 available, but to the target command, you must supply "serial" as the
4706 device type instead of "/dev/ttyXX". See mpw-README in the main
4707 directory for more information on how to build. The MPW configuration
4708 scripts */mpw-config.in support only a few targets, and only the
4709 mips-idt-ecoff target has been tested.
4713 GDB configuration now uses autoconf. This is not user-visible,
4714 but does simplify configuration and building.
4718 GDB now supports hpux10.
4720 *** Changes in GDB-4.14:
4722 * New native configurations
4724 x86 FreeBSD i[345]86-*-freebsd
4725 x86 NetBSD i[345]86-*-netbsd
4726 NS32k NetBSD ns32k-*-netbsd
4727 Sparc NetBSD sparc-*-netbsd
4731 A29K VxWorks a29k-*-vxworks
4732 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4733 CPU32 EST-300 emulator m68*-*-est*
4734 PowerPC ELF powerpc-*-elf
4737 * Alpha OSF/1 support for procfs
4739 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4740 possible to attach to running processes. As the mounting of the /proc
4741 filesystem is optional on the Alpha, GDB automatically determines
4742 the availability of /proc during startup. This can lead to problems
4743 if /proc is unmounted after GDB has been started.
4745 * Arguments to user-defined commands
4747 User commands may accept up to 10 arguments separated by whitespace.
4748 Arguments are accessed within the user command via $arg0..$arg9. A
4751 print $arg0 + $arg1 + $arg2
4753 To execute the command use:
4756 Defines the command "adder" which prints the sum of its three arguments.
4757 Note the arguments are text substitutions, so they may reference variables,
4758 use complex expressions, or even perform inferior function calls.
4760 * New `if' and `while' commands
4762 This makes it possible to write more sophisticated user-defined
4763 commands. Both commands take a single argument, which is the
4764 expression to evaluate, and must be followed by the commands to
4765 execute, one per line, if the expression is nonzero, the list being
4766 terminated by the word `end'. The `if' command list may include an
4767 `else' word, which causes the following commands to be executed only
4768 if the expression is zero.
4770 * Fortran source language mode
4772 GDB now includes partial support for Fortran 77. It will recognize
4773 Fortran programs and can evaluate a subset of Fortran expressions, but
4774 variables and functions may not be handled correctly. GDB will work
4775 with G77, but does not yet know much about symbols emitted by other
4778 * Better HPUX support
4780 Most debugging facilities now work on dynamic executables for HPPAs
4781 running hpux9 or later. You can attach to running dynamically linked
4782 processes, but by default the dynamic libraries will be read-only, so
4783 for instance you won't be able to put breakpoints in them. To change
4784 that behavior do the following before running the program:
4790 This will cause the libraries to be mapped private and read-write.
4791 To revert to the normal behavior, do this:
4797 You cannot set breakpoints or examine data in the library until after
4798 the library is loaded if the function/data symbols do not have
4801 GDB can now also read debug symbols produced by the HP C compiler on
4802 HPPAs (sorry, no C++, Fortran or 68k support).
4804 * Target byte order now dynamically selectable
4806 You can choose which byte order to use with a target system, via the
4807 commands "set endian big" and "set endian little", and you can see the
4808 current setting by using "show endian". You can also give the command
4809 "set endian auto", in which case GDB will use the byte order
4810 associated with the executable. Currently, only embedded MIPS
4811 configurations support dynamic selection of target byte order.
4813 * New DOS host serial code
4815 This version uses DPMI interrupts to handle buffered I/O, so you
4816 no longer need to run asynctsr when debugging boards connected to
4819 *** Changes in GDB-4.13:
4821 * New "complete" command
4823 This lists all the possible completions for the rest of the line, if it
4824 were to be given as a command itself. This is intended for use by emacs.
4826 * Trailing space optional in prompt
4828 "set prompt" no longer adds a space for you after the prompt you set. This
4829 allows you to set a prompt which ends in a space or one that does not.
4831 * Breakpoint hit counts
4833 "info break" now displays a count of the number of times the breakpoint
4834 has been hit. This is especially useful in conjunction with "ignore"; you
4835 can ignore a large number of breakpoint hits, look at the breakpoint info
4836 to see how many times the breakpoint was hit, then run again, ignoring one
4837 less than that number, and this will get you quickly to the last hit of
4840 * Ability to stop printing at NULL character
4842 "set print null-stop" will cause GDB to stop printing the characters of
4843 an array when the first NULL is encountered. This is useful when large
4844 arrays actually contain only short strings.
4846 * Shared library breakpoints
4848 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4849 breakpoints in shared libraries before the executable is run.
4851 * Hardware watchpoints
4853 There is a new hardware breakpoint for the watch command for sparclite
4854 targets. See gdb/sparclite/hw_breakpoint.note.
4856 Hardware watchpoints are also now supported under GNU/Linux.
4860 Annotations have been added. These are for use with graphical interfaces,
4861 and are still experimental. Currently only gdba.el uses these.
4863 * Improved Irix 5 support
4865 GDB now works properly with Irix 5.2.
4867 * Improved HPPA support
4869 GDB now works properly with the latest GCC and GAS.
4871 * New native configurations
4873 Sequent PTX4 i[34]86-sequent-ptx4
4874 HPPA running OSF/1 hppa*-*-osf*
4875 Atari TT running SVR4 m68*-*-sysv4*
4876 RS/6000 LynxOS rs6000-*-lynxos*
4880 OS/9000 i[34]86-*-os9k
4881 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4884 * Hitachi SH7000 and E7000-PC ICE support
4886 There is now support for communicating with the Hitachi E7000-PC ICE.
4887 This is available automatically when GDB is configured for the SH.
4891 As usual, a variety of small fixes and improvements, both generic
4892 and configuration-specific. See the ChangeLog for more detail.
4894 *** Changes in GDB-4.12:
4896 * Irix 5 is now supported
4900 GDB-4.12 on the HPPA has a number of changes which make it unable
4901 to debug the output from the currently released versions of GCC and
4902 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4903 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4904 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4907 *** Changes in GDB-4.11:
4909 * User visible changes:
4913 The "set remotedebug" option is now consistent between the mips remote
4914 target, remote targets using the gdb-specific protocol, UDI (AMD's
4915 debug protocol for the 29k) and the 88k bug monitor. It is now an
4916 integer specifying a debug level (normally 0 or 1, but 2 means more
4917 debugging info for the mips target).
4919 * DEC Alpha native support
4921 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4922 debug info, but GDB works fairly well with the DEC compiler and should
4923 work with a future GCC release. See the README file for a few
4924 Alpha-specific notes.
4926 * Preliminary thread implementation
4928 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4930 * LynxOS native and target support for 386
4932 This release has been hosted on LynxOS 2.2, and also can be configured
4933 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4936 * Improvements in C++ mangling/demangling.
4938 This release has much better g++ debugging, specifically in name
4939 mangling/demangling, virtual function calls, print virtual table,
4940 call methods, ...etc.
4942 *** Changes in GDB-4.10:
4944 * User visible changes:
4946 Remote debugging using the GDB-specific (`target remote') protocol now
4947 supports the `load' command. This is only useful if you have some
4948 other way of getting the stub to the target system, and you can put it
4949 somewhere in memory where it won't get clobbered by the download.
4951 Filename completion now works.
4953 When run under emacs mode, the "info line" command now causes the
4954 arrow to point to the line specified. Also, "info line" prints
4955 addresses in symbolic form (as well as hex).
4957 All vxworks based targets now support a user settable option, called
4958 vxworks-timeout. This option represents the number of seconds gdb
4959 should wait for responses to rpc's. You might want to use this if
4960 your vxworks target is, perhaps, a slow software simulator or happens
4961 to be on the far side of a thin network line.
4965 This release contains support for using a DEC alpha as a GDB host for
4966 cross debugging. Native alpha debugging is not supported yet.
4969 *** Changes in GDB-4.9:
4973 This is the first GDB release which is accompanied by a matching testsuite.
4974 The testsuite requires installation of dejagnu, which should be available
4975 via ftp from most sites that carry GNU software.
4979 'Cfront' style demangling has had its name changed to 'ARM' style, to
4980 emphasize that it was written from the specifications in the C++ Annotated
4981 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4982 disclaimers, it still generated too much confusion with users attempting to
4983 use gdb with AT&T cfront.
4987 GDB now uses a standard remote interface to a simulator library.
4988 So far, the library contains simulators for the Zilog Z8001/2, the
4989 Hitachi H8/300, H8/500 and Super-H.
4991 * New targets supported
4993 H8/300 simulator h8300-hitachi-hms or h8300hms
4994 H8/500 simulator h8500-hitachi-hms or h8500hms
4995 SH simulator sh-hitachi-hms or sh
4996 Z8000 simulator z8k-zilog-none or z8ksim
4997 IDT MIPS board over serial line mips-idt-ecoff
4999 Cross-debugging to GO32 targets is supported. It requires a custom
5000 version of the i386-stub.c module which is integrated with the
5001 GO32 memory extender.
5003 * New remote protocols
5005 MIPS remote debugging protocol.
5007 * New source languages supported
5009 This version includes preliminary support for Chill, a Pascal like language
5010 used by telecommunications companies. Chill support is also being integrated
5011 into the GNU compiler, but we don't know when it will be publically available.
5014 *** Changes in GDB-4.8:
5016 * HP Precision Architecture supported
5018 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5019 version of this support was available as a set of patches from the
5020 University of Utah. GDB does not support debugging of programs
5021 compiled with the HP compiler, because HP will not document their file
5022 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5023 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5025 Many problems in the preliminary version have been fixed.
5027 * Faster and better demangling
5029 We have improved template demangling and fixed numerous bugs in the GNU style
5030 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5031 character types (wchar_t) are now supported. Demangling of each symbol is now
5032 only done once, and is cached when the symbol table for a file is read in.
5033 This results in a small increase in memory usage for C programs, a moderate
5034 increase in memory usage for C++ programs, and a fantastic speedup in
5037 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5038 from the specifications in the Annotated Reference Manual, which AT&T's
5039 compiler does not actually implement.
5041 * G++ multiple inheritance compiler problem
5043 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5044 inheritance lattices was reworked to properly discover ambiguities. We
5045 recently found an example which causes this new algorithm to fail in a
5046 very subtle way, producing bad debug information for those classes.
5047 The file 'gcc.patch' (in this directory) can be applied to gcc to
5048 circumvent the problem. A future GCC release will contain a complete
5051 The previous G++ debug info problem (mentioned below for the gdb-4.7
5052 release) is fixed in gcc version 2.3.2.
5054 * Improved configure script
5056 The `configure' script will now attempt to guess your system type if
5057 you don't supply a host system type. The old scheme of supplying a
5058 host system triplet is preferable over using this. All the magic is
5059 done in the new `config.guess' script. Examine it for details.
5061 We have also brought our configure script much more in line with the FSF's
5062 version. It now supports the --with-xxx options. In particular,
5063 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5064 The resulting GDB will not be able to read arbitrary object file formats --
5065 only the format ``expected'' to be used on the configured target system.
5066 We hope to make this the default in a future release.
5068 * Documentation improvements
5070 There's new internal documentation on how to modify GDB, and how to
5071 produce clean changes to the code. We implore people to read it
5072 before submitting changes.
5074 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5075 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5076 `info' files are also provided. To build `info' files from scratch,
5077 you will need the latest `makeinfo' release, which will be available in
5078 a future texinfo-X.Y release.
5080 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5081 We're not sure exactly which versions have this problem, but it has
5082 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5083 or better. If that isn't possible, there is a patch in
5084 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5085 around this problem.
5089 GDB now supports array constants that can be used in expressions typed in by
5090 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5091 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5094 The new directory `gdb/sparclite' contains a program that demonstrates
5095 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5097 * New native hosts supported
5099 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5100 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5102 * New targets supported
5104 AMD 29k family via UDI a29k-amd-udi or udi29k
5106 * New file formats supported
5108 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5109 HPUX core files, and SCO 3.2v2 core files.
5113 Attaching to processes now works again; thanks for the many bug reports.
5115 We have also stomped on a bunch of core dumps caused by
5116 printf_filtered("%s") problems.
5118 We eliminated a copyright problem on the rpc and ptrace header files
5119 for VxWorks, which was discovered at the last minute during the 4.7
5120 release. You should now be able to build a VxWorks GDB.
5122 You can now interrupt gdb while an attached process is running. This
5123 will cause the attached process to stop, and give control back to GDB.
5125 We fixed problems caused by using too many file descriptors
5126 for reading symbols from object files and libraries. This was
5127 especially a problem for programs that used many (~100) shared
5130 The `step' command now only enters a subroutine if there is line number
5131 information for the subroutine. Otherwise it acts like the `next'
5132 command. Previously, `step' would enter subroutines if there was
5133 any debugging information about the routine. This avoids problems
5134 when using `cc -g1' on MIPS machines.
5136 * Internal improvements
5138 GDB's internal interfaces have been improved to make it easier to support
5139 debugging of multiple languages in the future.
5141 GDB now uses a common structure for symbol information internally.
5142 Minimal symbols (derived from linkage symbols in object files), partial
5143 symbols (from a quick scan of debug information), and full symbols
5144 contain a common subset of information, making it easier to write
5145 shared code that handles any of them.
5147 * New command line options
5149 We now accept --silent as an alias for --quiet.
5153 The memory-mapped-malloc library is now licensed under the GNU Library
5154 General Public License.
5156 *** Changes in GDB-4.7:
5158 * Host/native/target split
5160 GDB has had some major internal surgery to untangle the support for
5161 hosts and remote targets. Now, when you configure GDB for a remote
5162 target, it will no longer load in all of the support for debugging
5163 local programs on the host. When fully completed and tested, this will
5164 ensure that arbitrary host/target combinations are possible.
5166 The primary conceptual shift is to separate the non-portable code in
5167 GDB into three categories. Host specific code is required any time GDB
5168 is compiled on that host, regardless of the target. Target specific
5169 code relates to the peculiarities of the target, but can be compiled on
5170 any host. Native specific code is everything else: it can only be
5171 built when the host and target are the same system. Child process
5172 handling and core file support are two common `native' examples.
5174 GDB's use of /proc for controlling Unix child processes is now cleaner.
5175 It has been split out into a single module under the `target_ops' vector,
5176 plus two native-dependent functions for each system that uses /proc.
5178 * New hosts supported
5180 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5181 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5182 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5184 * New targets supported
5186 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5187 68030 and CPU32 m68030-*-*, m68332-*-*
5189 * New native hosts supported
5191 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5192 (386bsd is not well tested yet)
5193 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5195 * New file formats supported
5197 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5198 supports reading of `a.out.adobe' object files, which are an a.out
5199 format extended with minimal information about multiple sections.
5203 `show copying' is the same as the old `info copying'.
5204 `show warranty' is the same as `info warrantee'.
5205 These were renamed for consistency. The old commands continue to work.
5207 `info handle' is a new alias for `info signals'.
5209 You can now define pre-command hooks, which attach arbitrary command
5210 scripts to any command. The commands in the hook will be executed
5211 prior to the user's command. You can also create a hook which will be
5212 executed whenever the program stops. See gdb.texinfo.
5216 We now deal with Cfront style name mangling, and can even extract type
5217 info from mangled symbols. GDB can automatically figure out which
5218 symbol mangling style your C++ compiler uses.
5220 Calling of methods and virtual functions has been improved as well.
5224 The crash that occured when debugging Sun Ansi-C compiled binaries is
5225 fixed. This was due to mishandling of the extra N_SO stabs output
5228 We also finally got Ultrix 4.2 running in house, and fixed core file
5229 support, with help from a dozen people on the net.
5231 John M. Farrell discovered that the reason that single-stepping was so
5232 slow on all of the Mips based platforms (primarily SGI and DEC) was
5233 that we were trying to demangle and lookup a symbol used for internal
5234 purposes on every instruction that was being stepped through. Changing
5235 the name of that symbol so that it couldn't be mistaken for a C++
5236 mangled symbol sped things up a great deal.
5238 Rich Pixley sped up symbol lookups in general by getting much smarter
5239 about when C++ symbol mangling is necessary. This should make symbol
5240 completion (TAB on the command line) much faster. It's not as fast as
5241 we'd like, but it's significantly faster than gdb-4.6.
5245 A new user controllable variable 'call_scratch_address' can
5246 specify the location of a scratch area to be used when GDB
5247 calls a function in the target. This is necessary because the
5248 usual method of putting the scratch area on the stack does not work
5249 in systems that have separate instruction and data spaces.
5251 We integrated changes to support the 29k UDI (Universal Debugger
5252 Interface), but discovered at the last minute that we didn't have all
5253 of the appropriate copyright paperwork. We are working with AMD to
5254 resolve this, and hope to have it available soon.
5258 We have sped up the remote serial line protocol, especially for targets
5259 with lots of registers. It now supports a new `expedited status' ('T')
5260 message which can be used in place of the existing 'S' status message.
5261 This allows the remote stub to send only the registers that GDB
5262 needs to make a quick decision about single-stepping or conditional
5263 breakpoints, eliminating the need to fetch the entire register set for
5264 each instruction being stepped through.
5266 The GDB remote serial protocol now implements a write-through cache for
5267 registers, only re-reading the registers if the target has run.
5269 There is also a new remote serial stub for SPARC processors. You can
5270 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5271 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5272 processor with a serial port.
5276 Configure.in files have become much easier to read and modify. A new
5277 `table driven' format makes it more obvious what configurations are
5278 supported, and what files each one uses.
5282 There is a new opcodes library which will eventually contain all of the
5283 disassembly routines and opcode tables. At present, it only contains
5284 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5285 disassembler (binutils/objdump) to share these routines.
5287 The libiberty library is now copylefted under the GNU Library General
5288 Public License. This allows more liberal use, and was done so libg++
5289 can use it. This makes no difference to GDB, since the Library License
5290 grants all the rights from the General Public License.
5294 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5295 reference to the stabs symbol info used by the debugger. It is (as far
5296 as we know) the only published document on this fascinating topic. We
5297 encourage you to read it, compare it to the stabs information on your
5298 system, and send improvements on the document in general (to
5299 bug-gdb@prep.ai.mit.edu).
5301 And, of course, many bugs have been fixed.
5304 *** Changes in GDB-4.6:
5306 * Better support for C++ function names
5308 GDB now accepts as input the "demangled form" of C++ overloaded function
5309 names and member function names, and can do command completion on such names
5310 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5311 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5312 Make use of command completion, it is your friend.
5314 GDB also now accepts a variety of C++ mangled symbol formats. They are
5315 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5316 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5317 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5318 for the list of formats.
5320 * G++ symbol mangling problem
5322 Recent versions of gcc have a bug in how they emit debugging information for
5323 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5324 directory) can be applied to gcc to fix the problem. Alternatively, if you
5325 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5326 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5327 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5330 * New 'maintenance' command
5332 All of the commands related to hacking GDB internals have been moved out of
5333 the main command set, and now live behind the 'maintenance' command. This
5334 can also be abbreviated as 'mt'. The following changes were made:
5336 dump-me -> maintenance dump-me
5337 info all-breakpoints -> maintenance info breakpoints
5338 printmsyms -> maintenance print msyms
5339 printobjfiles -> maintenance print objfiles
5340 printpsyms -> maintenance print psymbols
5341 printsyms -> maintenance print symbols
5343 The following commands are new:
5345 maintenance demangle Call internal GDB demangler routine to
5346 demangle a C++ link name and prints the result.
5347 maintenance print type Print a type chain for a given symbol
5349 * Change to .gdbinit file processing
5351 We now read the $HOME/.gdbinit file before processing the argv arguments
5352 (e.g. reading symbol files or core files). This allows global parameters to
5353 be set, which will apply during the symbol reading. The ./.gdbinit is still
5354 read after argv processing.
5356 * New hosts supported
5358 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5360 GNU/Linux support i386-unknown-linux or linux
5362 We are also including code to support the HP/PA running BSD and HPUX. This
5363 is almost guaranteed not to work, as we didn't have time to test or build it
5364 for this release. We are including it so that the more adventurous (or
5365 masochistic) of you can play with it. We also had major problems with the
5366 fact that the compiler that we got from HP doesn't support the -g option.
5369 * New targets supported
5371 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5373 * More smarts about finding #include files
5375 GDB now remembers the compilation directory for all include files, and for
5376 all files from which C is generated (like yacc and lex sources). This
5377 greatly improves GDB's ability to find yacc/lex sources, and include files,
5378 especially if you are debugging your program from a directory different from
5379 the one that contains your sources.
5381 We also fixed a bug which caused difficulty with listing and setting
5382 breakpoints in include files which contain C code. (In the past, you had to
5383 try twice in order to list an include file that you hadn't looked at before.)
5385 * Interesting infernals change
5387 GDB now deals with arbitrary numbers of sections, where the symbols for each
5388 section must be relocated relative to that section's landing place in the
5389 target's address space. This work was needed to support ELF with embedded
5390 stabs used by Solaris-2.0.
5392 * Bug fixes (of course!)
5394 There have been loads of fixes for the following things:
5395 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5396 i960, stabs, DOS(GO32), procfs, etc...
5398 See the ChangeLog for details.
5400 *** Changes in GDB-4.5:
5402 * New machines supported (host and target)
5404 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5406 SGI Irix-4.x mips-sgi-irix4 or iris4
5408 * New malloc package
5410 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5411 Mmalloc is capable of handling mutiple heaps of memory. It is also
5412 capable of saving a heap to a file, and then mapping it back in later.
5413 This can be used to greatly speedup the startup of GDB by using a
5414 pre-parsed symbol table which lives in a mmalloc managed heap. For
5415 more details, please read mmalloc/mmalloc.texi.
5419 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5420 'help info proc' for details.
5422 * MIPS ecoff symbol table format
5424 The code that reads MIPS symbol table format is now supported on all hosts.
5425 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5428 * File name changes for MS-DOS
5430 Many files in the config directories have been renamed to make it easier to
5431 support GDB on MS-DOSe systems (which have very restrictive file name
5432 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5433 environment) is close to working but has some remaining problems. Note
5434 that debugging of DOS programs is not supported, due to limitations
5435 in the ``operating system'', but it can be used to host cross-debugging.
5437 * Cross byte order fixes
5439 Many fixes have been made to support cross debugging of Sparc and MIPS
5440 targets from hosts whose byte order differs.
5442 * New -mapped and -readnow options
5444 If memory-mapped files are available on your system through the 'mmap'
5445 system call, you can use the -mapped option on the `file' or
5446 `symbol-file' commands to cause GDB to write the symbols from your
5447 program into a reusable file. If the program you are debugging is
5448 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5449 Future GDB debugging sessions will notice the presence of this file,
5450 and will quickly map in symbol information from it, rather than reading
5451 the symbol table from the executable program. Using the '-mapped'
5452 option in a GDB `file' or `symbol-file' command has the same effect as
5453 starting GDB with the '-mapped' command-line option.
5455 You can cause GDB to read the entire symbol table immediately by using
5456 the '-readnow' option with any of the commands that load symbol table
5457 information (or on the GDB command line). This makes the command
5458 slower, but makes future operations faster.
5460 The -mapped and -readnow options are typically combined in order to
5461 build a `fred.syms' file that contains complete symbol information.
5462 A simple GDB invocation to do nothing but build a `.syms' file for future
5465 gdb -batch -nx -mapped -readnow programname
5467 The `.syms' file is specific to the host machine on which GDB is run.
5468 It holds an exact image of GDB's internal symbol table. It cannot be
5469 shared across multiple host platforms.
5471 * longjmp() handling
5473 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5474 siglongjmp() without losing control. This feature has not yet been ported to
5475 all systems. It currently works on many 386 platforms, all MIPS-based
5476 platforms (SGI, DECstation, etc), and Sun3/4.
5480 Preliminary work has been put in to support the new Solaris OS from Sun. At
5481 this time, it can control and debug processes, but it is not capable of
5486 As always, many many bug fixes. The major areas were with g++, and mipsread.
5487 People using the MIPS-based platforms should experience fewer mysterious
5488 crashes and trashed symbol tables.
5490 *** Changes in GDB-4.4:
5492 * New machines supported (host and target)
5494 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5496 BSD Reno on Vax vax-dec-bsd
5497 Ultrix on Vax vax-dec-ultrix
5499 * New machines supported (target)
5501 AMD 29000 embedded, using EBMON a29k-none-none
5505 GDB continues to improve its handling of C++. `References' work better.
5506 The demangler has also been improved, and now deals with symbols mangled as
5507 per the Annotated C++ Reference Guide.
5509 GDB also now handles `stabs' symbol information embedded in MIPS
5510 `ecoff' symbol tables. Since the ecoff format was not easily
5511 extensible to handle new languages such as C++, this appeared to be a
5512 good way to put C++ debugging info into MIPS binaries. This option
5513 will be supported in the GNU C compiler, version 2, when it is
5516 * New features for SVR4
5518 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5519 shared libraries. Debugging dynamically linked programs should present
5520 only minor differences from debugging statically linked programs.
5522 The `info proc' command will print out information about any process
5523 on an SVR4 system (including the one you are debugging). At the moment,
5524 it prints the address mappings of the process.
5526 If you bring up GDB on another SVR4 system, please send mail to
5527 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5529 * Better dynamic linking support in SunOS
5531 Reading symbols from shared libraries which contain debugging symbols
5532 now works properly. However, there remain issues such as automatic
5533 skipping of `transfer vector' code during function calls, which
5534 make it harder to debug code in a shared library, than to debug the
5535 same code linked statically.
5539 GDB is now using the latest `getopt' routines from the FSF. This
5540 version accepts the -- prefix for options with long names. GDB will
5541 continue to accept the old forms (-option and +option) as well.
5542 Various single letter abbreviations for options have been explicity
5543 added to the option table so that they won't get overshadowed in the
5544 future by other options that begin with the same letter.
5548 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5549 Many assorted bugs have been handled. Many more remain to be handled.
5550 See the various ChangeLog files (primarily in gdb and bfd) for details.
5553 *** Changes in GDB-4.3:
5555 * New machines supported (host and target)
5557 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5558 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5559 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5561 * Almost SCO Unix support
5563 We had hoped to support:
5564 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5565 (except for core file support), but we discovered very late in the release
5566 that it has problems with process groups that render gdb unusable. Sorry
5567 about that. I encourage people to fix it and post the fixes.
5569 * Preliminary ELF and DWARF support
5571 GDB can read ELF object files on System V Release 4, and can handle
5572 debugging records for C, in DWARF format, in ELF files. This support
5573 is preliminary. If you bring up GDB on another SVR4 system, please
5574 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5579 GDB now uses the latest `readline' library. One user-visible change
5580 is that two tabs will list possible command completions, which previously
5581 required typing M-? (meta-question mark, or ESC ?).
5585 The `stepi' bug that many of you noticed has been squashed.
5586 Many bugs in C++ have been handled. Many more remain to be handled.
5587 See the various ChangeLog files (primarily in gdb and bfd) for details.
5589 * State of the MIPS world (in case you wondered):
5591 GDB can understand the symbol tables emitted by the compilers
5592 supplied by most vendors of MIPS-based machines, including DEC. These
5593 symbol tables are in a format that essentially nobody else uses.
5595 Some versions of gcc come with an assembler post-processor called
5596 mips-tfile. This program is required if you want to do source-level
5597 debugging of gcc-compiled programs. I believe FSF does not ship
5598 mips-tfile with gcc version 1, but it will eventually come with gcc
5601 Debugging of g++ output remains a problem. g++ version 1.xx does not
5602 really support it at all. (If you're lucky, you should be able to get
5603 line numbers and stack traces to work, but no parameters or local
5604 variables.) With some work it should be possible to improve the
5607 When gcc version 2 is released, you will have somewhat better luck.
5608 However, even then you will get confusing results for inheritance and
5611 We will eventually provide full debugging of g++ output on
5612 DECstations. This will probably involve some kind of stabs-in-ecoff
5613 encapulation, but the details have not been worked out yet.
5616 *** Changes in GDB-4.2:
5618 * Improved configuration
5620 Only one copy of `configure' exists now, and it is not self-modifying.
5621 Porting BFD is simpler.
5625 The `step' and `next' commands now only stop at the first instruction
5626 of a source line. This prevents the multiple stops that used to occur
5627 in switch statements, for-loops, etc. `Step' continues to stop if a
5628 function that has debugging information is called within the line.
5632 Lots of small bugs fixed. More remain.
5634 * New host supported (not target)
5636 Intel 386 PC clone running Mach i386-none-mach
5639 *** Changes in GDB-4.1:
5641 * Multiple source language support
5643 GDB now has internal scaffolding to handle several source languages.
5644 It determines the type of each source file from its filename extension,
5645 and will switch expression parsing and number formatting to match the
5646 language of the function in the currently selected stack frame.
5647 You can also specifically set the language to be used, with
5648 `set language c' or `set language modula-2'.
5652 GDB now has preliminary support for the GNU Modula-2 compiler,
5653 currently under development at the State University of New York at
5654 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5655 continue through the fall of 1991 and into 1992.
5657 Other Modula-2 compilers are currently not supported, and attempting to
5658 debug programs compiled with them will likely result in an error as the
5659 symbol table is read. Feel free to work on it, though!
5661 There are hooks in GDB for strict type checking and range checking,
5662 in the `Modula-2 philosophy', but they do not currently work.
5666 GDB can now write to executable and core files (e.g. patch
5667 a variable's value). You must turn this switch on, specify
5668 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5669 by assigning a new value to a variable. Modifications take
5672 * Automatic SunOS shared library reading
5674 When you run your program, GDB automatically determines where its
5675 shared libraries (if any) have been loaded, and reads their symbols.
5676 The `share' command is no longer needed. This also works when
5677 examining core files.
5681 You can specify the number of lines that the `list' command shows.
5684 * New machines supported (host and target)
5686 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5687 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5688 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5690 * New hosts supported (not targets)
5692 IBM RT/PC: romp-ibm-aix or rtpc
5694 * New targets supported (not hosts)
5696 AMD 29000 embedded with COFF a29k-none-coff
5697 AMD 29000 embedded with a.out a29k-none-aout
5698 Ultracomputer remote kernel debug a29k-nyu-kern
5700 * New remote interfaces
5706 *** Changes in GDB-4.0:
5710 Wide output is wrapped at good places to make the output more readable.
5712 Gdb now supports cross-debugging from a host machine of one type to a
5713 target machine of another type. Communication with the target system
5714 is over serial lines. The ``target'' command handles connecting to the
5715 remote system; the ``load'' command will download a program into the
5716 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5717 also supports debugging of realtime processes running under VxWorks,
5718 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5719 stub on the target system.
5721 New CPUs supported include the AMD 29000 and Intel 960.
5723 GDB now reads object files and symbol tables via a ``binary file''
5724 library, which allows a single copy of GDB to debug programs of multiple
5725 object file types such as a.out and coff.
5727 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5728 refcard.dvi and refcard.ps are available to format it).
5731 * Control-Variable user interface simplified
5733 All variables that control the operation of the debugger can be set
5734 by the ``set'' command, and displayed by the ``show'' command.
5736 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5737 ``Show prompt'' produces the response:
5738 Gdb's prompt is new-gdb=>.
5740 What follows are the NEW set commands. The command ``help set'' will
5741 print a complete list of old and new set commands. ``help set FOO''
5742 will give a longer description of the variable FOO. ``show'' will show
5743 all of the variable descriptions and their current settings.
5745 confirm on/off: Enables warning questions for operations that are
5746 hard to recover from, e.g. rerunning the program while
5747 it is already running. Default is ON.
5749 editing on/off: Enables EMACS style command line editing
5750 of input. Previous lines can be recalled with
5751 control-P, the current line can be edited with control-B,
5752 you can search for commands with control-R, etc.
5755 history filename NAME: NAME is where the gdb command history
5756 will be stored. The default is .gdb_history,
5757 or the value of the environment variable
5760 history size N: The size, in commands, of the command history. The
5761 default is 256, or the value of the environment variable
5764 history save on/off: If this value is set to ON, the history file will
5765 be saved after exiting gdb. If set to OFF, the
5766 file will not be saved. The default is OFF.
5768 history expansion on/off: If this value is set to ON, then csh-like
5769 history expansion will be performed on
5770 command line input. The default is OFF.
5772 radix N: Sets the default radix for input and output. It can be set
5773 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5774 in the current radix, so "set radix 10" is always a no-op.
5776 height N: This integer value is the number of lines on a page. Default
5777 is 24, the current `stty rows'' setting, or the ``li#''
5778 setting from the termcap entry matching the environment
5781 width N: This integer value is the number of characters on a line.
5782 Default is 80, the current `stty cols'' setting, or the ``co#''
5783 setting from the termcap entry matching the environment
5786 Note: ``set screensize'' is obsolete. Use ``set height'' and
5787 ``set width'' instead.
5789 print address on/off: Print memory addresses in various command displays,
5790 such as stack traces and structure values. Gdb looks
5791 more ``symbolic'' if you turn this off; it looks more
5792 ``machine level'' with it on. Default is ON.
5794 print array on/off: Prettyprint arrays. New convenient format! Default
5797 print demangle on/off: Print C++ symbols in "source" form if on,
5800 print asm-demangle on/off: Same, for assembler level printouts
5803 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5806 * Support for Epoch Environment.
5808 The epoch environment is a version of Emacs v18 with windowing. One
5809 new command, ``inspect'', is identical to ``print'', except that if you
5810 are running in the epoch environment, the value is printed in its own
5814 * Support for Shared Libraries
5816 GDB can now debug programs and core files that use SunOS shared libraries.
5817 Symbols from a shared library cannot be referenced
5818 before the shared library has been linked with the program (this
5819 happens after you type ``run'' and before the function main() is entered).
5820 At any time after this linking (including when examining core files
5821 from dynamically linked programs), gdb reads the symbols from each
5822 shared library when you type the ``sharedlibrary'' command.
5823 It can be abbreviated ``share''.
5825 sharedlibrary REGEXP: Load shared object library symbols for files
5826 matching a unix regular expression. No argument
5827 indicates to load symbols for all shared libraries.
5829 info sharedlibrary: Status of loaded shared libraries.
5834 A watchpoint stops execution of a program whenever the value of an
5835 expression changes. Checking for this slows down execution
5836 tremendously whenever you are in the scope of the expression, but is
5837 quite useful for catching tough ``bit-spreader'' or pointer misuse
5838 problems. Some machines such as the 386 have hardware for doing this
5839 more quickly, and future versions of gdb will use this hardware.
5841 watch EXP: Set a watchpoint (breakpoint) for an expression.
5843 info watchpoints: Information about your watchpoints.
5845 delete N: Deletes watchpoint number N (same as breakpoints).
5846 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5847 enable N: Re-enables watchpoint number N (same as breakpoints).
5850 * C++ multiple inheritance
5852 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5855 * C++ exception handling
5857 Gdb now supports limited C++ exception handling. Besides the existing
5858 ability to breakpoint on an exception handler, gdb can breakpoint on
5859 the raising of an exception (before the stack is peeled back to the
5862 catch FOO: If there is a FOO exception handler in the dynamic scope,
5863 set a breakpoint to catch exceptions which may be raised there.
5864 Multiple exceptions (``catch foo bar baz'') may be caught.
5866 info catch: Lists all exceptions which may be caught in the
5867 current stack frame.
5870 * Minor command changes
5872 The command ``call func (arg, arg, ...)'' now acts like the print
5873 command, except it does not print or save a value if the function's result
5874 is void. This is similar to dbx usage.
5876 The ``up'' and ``down'' commands now always print the frame they end up
5877 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5878 frames without printing.
5880 * New directory command
5882 'dir' now adds directories to the FRONT of the source search path.
5883 The path starts off empty. Source files that contain debug information
5884 about the directory in which they were compiled can be found even
5885 with an empty path; Sun CC and GCC include this information. If GDB can't
5886 find your source file in the current directory, type "dir .".
5888 * Configuring GDB for compilation
5890 For normal use, type ``./configure host''. See README or gdb.texinfo
5893 GDB now handles cross debugging. If you are remotely debugging between
5894 two different machines, type ``./configure host -target=targ''.
5895 Host is the machine where GDB will run; targ is the machine
5896 where the program that you are debugging will run.