1 What has changed in GDB?
2 (Organized release by release)
6 New events which are triggered when GDB modifies the state of the
9 ** gdb.events.inferior_call_pre: Function call is about to be made.
10 ** gdb.events.inferior_call_post: Function call has just been made.
11 ** gdb.events.memory_changed: A memory location has been altered.
12 ** gdb.events.register_changed: A register has been altered.
14 *** Changes since GDB 7.8
16 * GDB now supports hardware watchpoints on x86 GNU Hurd.
20 ** You can now access frame registers from Python scripts.
21 ** New attribute 'producer' for gdb.Symtab objects.
22 ** gdb.Objfile objects have a new attribute "progspace",
23 which is the gdb.Progspace object of the containing program space.
24 ** gdb.Objfile objects have a new attribute "owner".
25 ** gdb.Objfile objects have a new attribute "build_id",
26 which is the build ID generated when the file was built.
27 ** gdb.Objfile objects have a new method "add_separate_debug_file".
28 ** A new event "gdb.clear_objfiles" has been added, triggered when
29 selecting a new file to debug.
30 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
32 * New Python-based convenience functions:
34 ** $_caller_is(name [, number_of_frames])
35 ** $_caller_matches(regexp [, number_of_frames])
36 ** $_any_caller_is(name [, number_of_frames])
37 ** $_any_caller_matches(regexp [, number_of_frames])
41 queue-signal signal-name-or-number
42 Queue a signal to be delivered to the thread when it is resumed.
44 add-auto-load-scripts-directory directory
45 Add entries to the list of directories from which to load auto-loaded
48 * On resume, GDB now always passes the signal the program had stopped
49 for to the thread the signal was sent to, even if the user changed
50 threads before resuming. Previously GDB would often (but not
51 always) deliver the signal to the thread that happens to be current
54 * Conversely, the "signal" command now consistently delivers the
55 requested signal to the current thread. GDB now asks for
56 confirmation if the program had stopped for a signal and the user
57 switched threads meanwhile.
59 * "breakpoint always-inserted" modes "off" and "auto" merged.
61 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
62 won't remove breakpoints from the target until all threads stop,
63 even in non-stop mode. The "auto" mode has been removed, and "off"
64 is now the default mode.
68 ** The -list-thread-groups command outputs an exit-code field for
69 inferiors that have exited.
73 Support for these obsolete configurations has been removed.
75 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
76 SGI Irix-5.x mips-*-irix5*
77 SGI Irix-6.x mips-*-irix6*
78 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
79 VAX running Ultrix vax-*-ultrix*
81 *** Changes in GDB 7.8
83 * New command line options
86 This is an alias for the --data-directory option.
88 * GDB supports printing and modifying of variable length automatic arrays
89 as specified in ISO C99.
91 * The ARM simulator now supports instruction level tracing
92 with or without disassembly.
96 GDB now has support for scripting using Guile. Whether this is
97 available is determined at configure time.
98 Guile version 2.0 or greater is required.
99 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
101 * New commands (for set/show, see "New options" below)
105 Invoke CODE by passing it to the Guile interpreter.
109 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
111 info auto-load guile-scripts [regexp]
112 Print the list of automatically loaded Guile scripts.
114 * The source command is now capable of sourcing Guile scripts.
115 This feature is dependent on the debugger being built with Guile support.
119 set print symbol-loading (off|brief|full)
120 show print symbol-loading
121 Control whether to print informational messages when loading symbol
122 information for a file. The default is "full", but when debugging
123 programs with large numbers of shared libraries the amount of output
126 set guile print-stack (none|message|full)
127 show guile print-stack
128 Show a stack trace when an error is encountered in a Guile script.
130 set auto-load guile-scripts (on|off)
131 show auto-load guile-scripts
132 Control auto-loading of Guile script files.
134 maint ada set ignore-descriptive-types (on|off)
135 maint ada show ignore-descriptive-types
136 Control whether the debugger should ignore descriptive types in Ada
137 programs. The default is not to ignore the descriptive types. See
138 the user manual for more details on descriptive types and the intended
139 usage of this option.
141 set auto-connect-native-target
143 Control whether GDB is allowed to automatically connect to the
144 native target for the run, attach, etc. commands when not connected
145 to any target yet. See also "target native" below.
147 set record btrace replay-memory-access (read-only|read-write)
148 show record btrace replay-memory-access
149 Control what memory accesses are allowed during replay.
151 maint set target-async (on|off)
152 maint show target-async
153 This controls whether GDB targets operate in synchronous or
154 asynchronous mode. Normally the default is asynchronous, if it is
155 available; but this can be changed to more easily debug problems
156 occurring only in synchronous mode.
158 set mi-async (on|off)
160 Control whether MI asynchronous mode is preferred. This supersedes
161 "set target-async" of previous GDB versions.
163 * "set target-async" is deprecated as a CLI option and is now an alias
164 for "set mi-async" (only puts MI into async mode).
166 * Background execution commands (e.g., "c&", "s&", etc.) are now
167 possible ``out of the box'' if the target supports them. Previously
168 the user would need to explicitly enable the possibility with the
169 "set target-async on" command.
171 * New features in the GDB remote stub, GDBserver
173 ** New option --debug-format=option1[,option2,...] allows one to add
174 additional text to each output. At present only timestamps
175 are supported: --debug-format=timestamps.
176 Timestamps can also be turned on with the
177 "monitor set debug-format timestamps" command from GDB.
179 * The 'record instruction-history' command now starts counting instructions
180 at one. This also affects the instruction ranges reported by the
181 'record function-call-history' command when given the /i modifier.
183 * The command 'record function-call-history' supports a new modifier '/c' to
184 indent the function names based on their call stack depth.
185 The fields for the '/i' and '/l' modifier have been reordered.
186 The source line range is now prefixed with 'at'.
187 The instruction range is now prefixed with 'inst'.
188 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
189 "record instruction-history" and "list" commands.
191 * The ranges given as arguments to the 'record function-call-history' and
192 'record instruction-history' commands are now inclusive.
194 * The btrace record target now supports the 'record goto' command.
195 For locations inside the execution trace, the back trace is computed
196 based on the information stored in the execution trace.
198 * The btrace record target supports limited reverse execution and replay.
199 The target does not record data and therefore does not allow reading
202 * The "catch syscall" command now works on s390*-linux* targets.
204 * The "compare-sections" command is no longer specific to target
205 remote. It now works with all targets.
207 * All native targets are now consistently called "native".
208 Consequently, the "target child", "target GNU", "target djgpp",
209 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
210 commands have been replaced with "target native". The QNX/NTO port
211 leaves the "procfs" target in place and adds a "native" target for
212 consistency with other ports. The impact on users should be minimal
213 as these commands previously either throwed an error, or were
214 no-ops. The target's name is visible in the output of the following
215 commands: "help target", "info target", "info files", "maint print
218 * The "target native" command now connects to the native target. This
219 can be used to launch native programs even when "set
220 auto-connect-native-target" is set to off.
222 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.
224 * Support for Intel(R) AVX-512 registers on GNU/Linux.
225 Support displaying and modifying Intel(R) AVX-512 registers
226 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
230 qXfer:btrace:read's annex
231 The qXfer:btrace:read packet supports a new annex 'delta' to read
232 branch trace incrementally.
236 ** Valid Python operations on gdb.Value objects representing
237 structs/classes invoke the corresponding overloaded operators if
239 ** New `Xmethods' feature in the Python API. Xmethods are
240 additional methods or replacements for existing methods of a C++
241 class. This feature is useful for those cases where a method
242 defined in C++ source code could be inlined or optimized out by
243 the compiler, making it unavailable to GDB.
246 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
248 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
249 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
250 its alias "share", instead.
252 * The commands "set remotebaud" and "show remotebaud" are no longer
253 supported. Use "set serial baud" and "show serial baud" (respectively)
258 ** A new option "-gdb-set mi-async" replaces "-gdb-set
259 target-async". The latter is left as a deprecated alias of the
260 former for backward compatibility. If the target supports it,
261 CLI background execution commands are now always possible by
262 default, independently of whether the frontend stated a
263 preference for asynchronous execution with "-gdb-set mi-async".
264 Previously "-gdb-set target-async off" affected both MI execution
265 commands and CLI execution commands.
267 *** Changes in GDB 7.7
269 * Improved support for process record-replay and reverse debugging on
270 arm*-linux* targets. Support for thumb32 and syscall instruction
271 recording has been added.
273 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
275 * GDB now supports Fission DWP file format version 2.
276 http://gcc.gnu.org/wiki/DebugFission
278 * New convenience function "$_isvoid", to check whether an expression
279 is void. A void expression is an expression where the type of the
280 result is "void". For example, some convenience variables may be
281 "void" when evaluated (e.g., "$_exitcode" before the execution of
282 the program being debugged; or an undefined convenience variable).
283 Another example, when calling a function whose return type is
286 * The "maintenance print objfiles" command now takes an optional regexp.
288 * The "catch syscall" command now works on arm*-linux* targets.
290 * GDB now consistently shows "<not saved>" when printing values of
291 registers the debug info indicates have not been saved in the frame
292 and there's nowhere to retrieve them from
293 (callee-saved/call-clobbered registers):
298 (gdb) info registers rax
301 Before, the former would print "<optimized out>", and the latter
302 "*value not available*".
304 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
309 ** Frame filters and frame decorators have been added.
310 ** Temporary breakpoints are now supported.
311 ** Line tables representation has been added.
312 ** New attribute 'parent_type' for gdb.Field objects.
313 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
314 ** New attribute 'name' for gdb.Type objects.
318 Nios II ELF nios2*-*-elf
319 Nios II GNU/Linux nios2*-*-linux
320 Texas Instruments MSP430 msp430*-*-elf
322 * Removed native configurations
324 Support for these a.out NetBSD and OpenBSD obsolete configurations has
325 been removed. ELF variants of these configurations are kept supported.
327 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
328 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
329 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
330 i[34567]86-*-openbsd3.[0-3]
331 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
332 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
333 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
337 Like "catch throw", but catches a re-thrown exception.
339 Renamed from old "maint check-symtabs".
341 Perform consistency checks on symtabs.
343 Expand symtabs matching an optional regexp.
346 Display the details of GDB configure-time options.
348 maint set|show per-command
349 maint set|show per-command space
350 maint set|show per-command time
351 maint set|show per-command symtab
352 Enable display of per-command gdb resource usage.
354 remove-symbol-file FILENAME
355 remove-symbol-file -a ADDRESS
356 Remove a symbol file added via add-symbol-file. The file to remove
357 can be identified by its filename or by an address that lies within
358 the boundaries of this symbol file in memory.
361 info exceptions REGEXP
362 Display the list of Ada exceptions defined in the program being
363 debugged. If provided, only the exceptions whose names match REGEXP
368 set debug symfile off|on
370 Control display of debugging info regarding reading symbol files and
371 symbol tables within those files
373 set print raw frame-arguments
374 show print raw frame-arguments
375 Set/show whether to print frame arguments in raw mode,
376 disregarding any defined pretty-printers.
378 set remote trace-status-packet
379 show remote trace-status-packet
380 Set/show the use of remote protocol qTStatus packet.
384 Control display of debugging messages related to Nios II targets.
388 Control whether target-assisted range stepping is enabled.
390 set startup-with-shell
391 show startup-with-shell
392 Specifies whether Unix child processes are started via a shell or
397 Use the target memory cache for accesses to the code segment. This
398 improves performance of remote debugging (particularly disassembly).
400 * You can now use a literal value 'unlimited' for options that
401 interpret 0 or -1 as meaning "unlimited". E.g., "set
402 trace-buffer-size unlimited" is now an alias for "set
403 trace-buffer-size -1" and "set height unlimited" is now an alias for
406 * The "set debug symtab-create" debugging option of GDB has been changed to
407 accept a verbosity level. 0 means "off", 1 provides basic debugging
408 output, and values of 2 or greater provides more verbose output.
410 * New command-line options
412 Display the details of GDB configure-time options.
414 * The command 'tsave' can now support new option '-ctf' to save trace
415 buffer in Common Trace Format.
417 * Newly installed $prefix/bin/gcore acts as a shell interface for the
420 * GDB now implements the the C++ 'typeid' operator.
422 * The new convenience variable $_exception holds the exception being
423 thrown or caught at an exception-related catchpoint.
425 * The exception-related catchpoints, like "catch throw", now accept a
426 regular expression which can be used to filter exceptions by type.
428 * The new convenience variable $_exitsignal is automatically set to
429 the terminating signal number when the program being debugged dies
430 due to an uncaught signal.
434 ** All MI commands now accept an optional "--language" option.
435 Support for this feature can be verified by using the "-list-features"
436 command, which should contain "language-option".
438 ** The new command -info-gdb-mi-command allows the user to determine
439 whether a GDB/MI command is supported or not.
441 ** The "^error" result record returned when trying to execute an undefined
442 GDB/MI command now provides a variable named "code" whose content is the
443 "undefined-command" error code. Support for this feature can be verified
444 by using the "-list-features" command, which should contain
445 "undefined-command-error-code".
447 ** The -trace-save MI command can optionally save trace buffer in Common
450 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
452 ** The command -data-list-register-values now accepts an optional
453 "--skip-unavailable" option. When used, only the available registers
456 ** The new command -trace-frame-collected dumps collected variables,
457 computed expressions, tvars, memory and registers in a traceframe.
459 ** The commands -stack-list-locals, -stack-list-arguments and
460 -stack-list-variables now accept an option "--skip-unavailable".
461 When used, only the available locals or arguments are displayed.
463 ** The -exec-run command now accepts an optional "--start" option.
464 When used, the command follows the same semantics as the "start"
465 command, stopping the program's execution at the start of its
466 main subprogram. Support for this feature can be verified using
467 the "-list-features" command, which should contain
468 "exec-run-start-option".
470 ** The new commands -catch-assert and -catch-exceptions insert
471 catchpoints stopping the program when Ada exceptions are raised.
473 ** The new command -info-ada-exceptions provides the equivalent of
474 the new "info exceptions" command.
476 * New system-wide configuration scripts
477 A GDB installation now provides scripts suitable for use as system-wide
478 configuration scripts for the following systems:
482 * GDB now supports target-assigned range stepping with remote targets.
483 This improves the performance of stepping source lines by reducing
484 the number of control packets from/to GDB. See "New remote packets"
487 * GDB now understands the element 'tvar' in the XML traceframe info.
488 It has the id of the collected trace state variables.
490 * On S/390 targets that provide the transactional-execution feature,
491 the program interruption transaction diagnostic block (TDB) is now
492 represented as a number of additional "registers" in GDB.
498 The vCont packet supports a new 'r' action, that tells the remote
499 stub to step through an address range itself, without GDB
500 involvemement at each single-step.
502 qXfer:libraries-svr4:read's annex
503 The previously unused annex of the qXfer:libraries-svr4:read packet
504 is now used to support passing an argument list. The remote stub
505 reports support for this argument list to GDB's qSupported query.
506 The defined arguments are "start" and "prev", used to reduce work
507 necessary for library list updating, resulting in significant
510 * New features in the GDB remote stub, GDBserver
512 ** GDBserver now supports target-assisted range stepping. Currently
513 enabled on x86/x86_64 GNU/Linux targets.
515 ** GDBserver now adds element 'tvar' in the XML in the reply to
516 'qXfer:traceframe-info:read'. It has the id of the collected
517 trace state variables.
519 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
522 * New 'z' formatter for printing and examining memory, this displays the
523 value as hexadecimal zero padded on the left to the size of the type.
525 * GDB can now use Windows x64 unwinding data.
527 * The "set remotebaud" command has been replaced by "set serial baud".
528 Similarly, "show remotebaud" has been replaced by "show serial baud".
529 The "set remotebaud" and "show remotebaud" commands are still available
530 to provide backward compatibility with older versions of GDB.
532 *** Changes in GDB 7.6
534 * Target record has been renamed to record-full.
535 Record/replay is now enabled with the "record full" command.
536 This also affects settings that are associated with full record/replay
537 that have been moved from "set/show record" to "set/show record full":
539 set|show record full insn-number-max
540 set|show record full stop-at-limit
541 set|show record full memory-query
543 * A new record target "record-btrace" has been added. The new target
544 uses hardware support to record the control-flow of a process. It
545 does not support replaying the execution, but it implements the
546 below new commands for investigating the recorded execution log.
547 This new recording method can be enabled using:
551 The "record-btrace" target is only available on Intel Atom processors
552 and requires a Linux kernel 2.6.32 or later.
554 * Two new commands have been added for record/replay to give information
555 about the recorded execution without having to replay the execution.
556 The commands are only supported by "record btrace".
558 record instruction-history prints the execution history at
559 instruction granularity
561 record function-call-history prints the execution history at
564 * New native configurations
566 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
567 FreeBSD/powerpc powerpc*-*-freebsd
568 x86_64/Cygwin x86_64-*-cygwin*
569 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
573 ARM AArch64 aarch64*-*-elf
574 ARM AArch64 GNU/Linux aarch64*-*-linux
575 Lynx 178 PowerPC powerpc-*-lynx*178
576 x86_64/Cygwin x86_64-*-cygwin*
577 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
579 * If the configured location of system.gdbinit file (as given by the
580 --with-system-gdbinit option at configure time) is in the
581 data-directory (as specified by --with-gdb-datadir at configure
582 time) or in one of its subdirectories, then GDB will look for the
583 system-wide init file in the directory specified by the
584 --data-directory command-line option.
586 * New command line options:
588 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
589 other initialization files, unlike -nx which disables all of them.
591 * Removed command line options
593 -epoch This was used by the gdb mode in Epoch, an ancient fork of
596 * The 'ptype' and 'whatis' commands now accept an argument to control
599 * 'info proc' now works on some core files.
603 ** Vectors can be created with gdb.Type.vector.
605 ** Python's atexit.register now works in GDB.
607 ** Types can be pretty-printed via a Python API.
609 ** Python 3 is now supported (in addition to Python 2.4 or later)
611 ** New class gdb.Architecture exposes GDB's internal representation
612 of architecture in the Python API.
614 ** New method Frame.architecture returns the gdb.Architecture object
615 corresponding to the frame's architecture.
617 * New Python-based convenience functions:
619 ** $_memeq(buf1, buf2, length)
620 ** $_streq(str1, str2)
622 ** $_regex(str, regex)
624 * The 'cd' command now defaults to using '~' (the home directory) if not
627 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
628 default for GCC since November 2000.
630 * The command 'forward-search' can now be abbreviated as 'fo'.
632 * The command 'info tracepoints' can now display 'installed on target'
633 or 'not installed on target' for each non-pending location of tracepoint.
635 * New configure options
637 --enable-libmcheck/--disable-libmcheck
638 By default, development versions are built with -lmcheck on hosts
639 that support it, in order to help track memory corruption issues.
640 Release versions, on the other hand, are built without -lmcheck
641 by default. The --enable-libmcheck/--disable-libmcheck configure
642 options allow the user to override that default.
643 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
644 This configure option allows the user to build GDB with
645 libbabeltrace using which GDB can read Common Trace Format data.
647 * New commands (for set/show, see "New options" below)
650 Catch signals. This is similar to "handle", but allows commands and
651 conditions to be attached.
654 List the BFDs known to GDB.
656 python-interactive [command]
658 Start a Python interactive prompt, or evaluate the optional command
659 and print the result of expressions.
662 "py" is a new alias for "python".
664 enable type-printer [name]...
665 disable type-printer [name]...
666 Enable or disable type printers.
670 ** For the Renesas Super-H architecture, the "regs" command has been removed
671 (has been deprecated in GDB 7.5), and "info all-registers" should be used
676 set print type methods (on|off)
677 show print type methods
678 Control whether method declarations are displayed by "ptype".
679 The default is to show them.
681 set print type typedefs (on|off)
682 show print type typedefs
683 Control whether typedef definitions are displayed by "ptype".
684 The default is to show them.
686 set filename-display basename|relative|absolute
687 show filename-display
688 Control the way in which filenames is displayed.
689 The default is "relative", which preserves previous behavior.
691 set trace-buffer-size
692 show trace-buffer-size
693 Request target to change the size of trace buffer.
695 set remote trace-buffer-size-packet auto|on|off
696 show remote trace-buffer-size-packet
697 Control the use of the remote protocol `QTBuffer:size' packet.
701 Control display of debugging messages related to ARM AArch64.
704 set debug coff-pe-read
705 show debug coff-pe-read
706 Control display of debugging messages related to reading of COFF/PE
711 Control display of debugging messages related to Mach-O symbols
714 set debug notification
715 show debug notification
716 Control display of debugging info for async remote notification.
720 ** Command parameter changes are now notified using new async record
721 "=cmd-param-changed".
722 ** Trace frame changes caused by command "tfind" are now notified using
723 new async record "=traceframe-changed".
724 ** The creation, deletion and modification of trace state variables
725 are now notified using new async records "=tsv-created",
726 "=tsv-deleted" and "=tsv-modified".
727 ** The start and stop of process record are now notified using new
728 async record "=record-started" and "=record-stopped".
729 ** Memory changes are now notified using new async record
731 ** The data-disassemble command response will include a "fullname" field
732 containing the absolute file name when source has been requested.
733 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
734 command, to allow pattern filling of memory areas.
735 ** New commands "-catch-load"/"-catch-unload" added for intercepting
736 library load/unload events.
737 ** The response to breakpoint commands and breakpoint async records
738 includes an "installed" field containing a boolean state about each
739 non-pending tracepoint location is whether installed on target or not.
740 ** Output of the "-trace-status" command includes a "trace-file" field
741 containing the name of the trace file being examined. This field is
742 optional, and only present when examining a trace file.
743 ** The "fullname" field is now always present along with the "file" field,
744 even if the file cannot be found by GDB.
746 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
747 You must have the LZMA library available when configuring GDB for this
748 feature to be enabled. For more information, see:
749 http://fedoraproject.org/wiki/Features/MiniDebugInfo
754 Set the size of trace buffer. The remote stub reports support for this
755 packet to gdb's qSupported query.
758 Enable Branch Trace Store (BTS)-based branch tracing for the current
759 thread. The remote stub reports support for this packet to gdb's
763 Disable branch tracing for the current thread. The remote stub reports
764 support for this packet to gdb's qSupported query.
767 Read the traced branches for the current thread. The remote stub
768 reports support for this packet to gdb's qSupported query.
770 *** Changes in GDB 7.5
772 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
773 for more x32 ABI info.
775 * GDB now supports access to MIPS DSP registers on Linux targets.
777 * GDB now supports debugging microMIPS binaries.
779 * The "info os" command on GNU/Linux can now display information on
780 several new classes of objects managed by the operating system:
781 "info os procgroups" lists process groups
782 "info os files" lists file descriptors
783 "info os sockets" lists internet-domain sockets
784 "info os shm" lists shared-memory regions
785 "info os semaphores" lists semaphores
786 "info os msg" lists message queues
787 "info os modules" lists loaded kernel modules
789 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
790 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
791 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
792 options and inspect the probe arguments using the new $_probe_arg family
793 of convenience variables. You can obtain more information about SystemTap
794 in <http://sourceware.org/systemtap/>.
796 * GDB now supports reversible debugging on ARM, it allows you to
797 debug basic ARM and THUMB instructions, and provides
798 record/replay support.
800 * The option "symbol-reloading" has been deleted as it is no longer used.
804 ** GDB commands implemented in Python can now be put in command class
807 ** The "maint set python print-stack on|off" is now deleted.
809 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
810 apply "flag enum"-style pretty-printing to any enum.
812 ** gdb.lookup_symbol can now work when there is no current frame.
814 ** gdb.Symbol now has a 'line' attribute, holding the line number in
815 the source at which the symbol was defined.
817 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
818 method 'value'. The former indicates whether the symbol needs a
819 frame in order to compute its value, and the latter computes the
822 ** A new method 'referenced_value' on gdb.Value objects which can
823 dereference pointer as well as C++ reference values.
825 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
826 which return the global and static blocks (as gdb.Block objects),
827 of the underlying symbol table, respectively.
829 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
830 object associated with a PC value.
832 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
833 of the address range occupied by code for the current source line.
835 * Go language support.
836 GDB now supports debugging programs written in the Go programming
839 * GDBserver now supports stdio connections.
840 E.g. (gdb) target remote | ssh myhost gdbserver - hello
842 * The binary "gdbtui" can no longer be built or installed.
843 Use "gdb -tui" instead.
845 * GDB will now print "flag" enums specially. A flag enum is one where
846 all the enumerator values have no bits in common when pairwise
847 "and"ed. When printing a value whose type is a flag enum, GDB will
848 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
849 (gdb) print (enum E) 3
852 * The filename part of a linespec will now match trailing components
853 of a source file name. For example, "break gcc/expr.c:1000" will
854 now set a breakpoint in build/gcc/expr.c, but not
857 * The "info proc" and "generate-core-file" commands will now also
858 work on remote targets connected to GDBserver on Linux.
860 * The command "info catch" has been removed. It has been disabled
863 * The "catch exception" and "catch assert" commands now accept
864 a condition at the end of the command, much like the "break"
865 command does. For instance:
867 (gdb) catch exception Constraint_Error if Barrier = True
869 Previously, it was possible to add a condition to such catchpoints,
870 but it had to be done as a second step, after the catchpoint had been
871 created, using the "condition" command.
873 * The "info static-tracepoint-marker" command will now also work on
874 native Linux targets with in-process agent.
876 * GDB can now set breakpoints on inlined functions.
878 * The .gdb_index section has been updated to include symbols for
879 inlined functions. GDB will ignore older .gdb_index sections by
880 default, which could cause symbol files to be loaded more slowly
881 until their .gdb_index sections can be recreated. The new command
882 "set use-deprecated-index-sections on" will cause GDB to use any older
883 .gdb_index sections it finds. This will restore performance, but the
884 ability to set breakpoints on inlined functions will be lost in symbol
885 files with older .gdb_index sections.
887 The .gdb_index section has also been updated to record more information
888 about each symbol. This speeds up the "info variables", "info functions"
889 and "info types" commands when used with programs having the .gdb_index
890 section, as well as speeding up debugging with shared libraries using
891 the .gdb_index section.
893 * Ada support for GDB/MI Variable Objects has been added.
895 * GDB can now support 'breakpoint always-inserted mode' in 'record'
900 ** New command -info-os is the MI equivalent of "info os".
902 ** Output logs ("set logging" and related) now include MI output.
906 ** "set use-deprecated-index-sections on|off"
907 "show use-deprecated-index-sections on|off"
908 Controls the use of deprecated .gdb_index sections.
910 ** "catch load" and "catch unload" can be used to stop when a shared
911 library is loaded or unloaded, respectively.
913 ** "enable count" can be used to auto-disable a breakpoint after
916 ** "info vtbl" can be used to show the virtual method tables for
917 C++ and Java objects.
919 ** "explore" and its sub commands "explore value" and "explore type"
920 can be used to recursively explore values and types of
921 expressions. These commands are available only if GDB is
922 configured with '--with-python'.
924 ** "info auto-load" shows status of all kinds of auto-loaded files,
925 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
926 sequences of commands files, "info auto-load python-scripts"
927 shows status of auto-loading Python script files,
928 "info auto-load local-gdbinit" shows status of loading init file
929 (.gdbinit) from current directory and "info auto-load libthread-db" shows
930 status of inferior specific thread debugging shared library loading.
932 ** "info auto-load-scripts", "set auto-load-scripts on|off"
933 and "show auto-load-scripts" commands have been deprecated, use their
934 "info auto-load python-scripts", "set auto-load python-scripts on|off"
935 and "show auto-load python-scripts" counterparts instead.
937 ** "dprintf location,format,args..." creates a dynamic printf, which
938 is basically a breakpoint that does a printf and immediately
939 resumes your program's execution, so it is like a printf that you
940 can insert dynamically at runtime instead of at compiletime.
942 ** "set print symbol"
944 Controls whether GDB attempts to display the symbol, if any,
945 corresponding to addresses it prints. This defaults to "on", but
946 you can set it to "off" to restore GDB's previous behavior.
948 * Deprecated commands
950 ** For the Renesas Super-H architecture, the "regs" command has been
951 deprecated, and "info all-registers" should be used instead.
955 Renesas RL78 rl78-*-elf
956 HP OpenVMS ia64 ia64-hp-openvms*
958 * GDBserver supports evaluation of breakpoint conditions. When
959 support is advertised by GDBserver, GDB may be told to send the
960 breakpoint conditions in bytecode form to GDBserver. GDBserver
961 will only report the breakpoint trigger to GDB when its condition
967 show mips compression
968 Select the compressed ISA encoding used in functions that have no symbol
969 information available. The encoding can be set to either of:
972 and is updated automatically from ELF file flags if available.
974 set breakpoint condition-evaluation
975 show breakpoint condition-evaluation
976 Control whether breakpoint conditions are evaluated by GDB ("host") or by
977 GDBserver ("target"). Default option "auto" chooses the most efficient
979 This option can improve debugger efficiency depending on the speed of the
983 Disable auto-loading globally.
986 Show auto-loading setting of all kinds of auto-loaded files.
988 set auto-load gdb-scripts on|off
989 show auto-load gdb-scripts
990 Control auto-loading of GDB canned sequences of commands files.
992 set auto-load python-scripts on|off
993 show auto-load python-scripts
994 Control auto-loading of Python script files.
996 set auto-load local-gdbinit on|off
997 show auto-load local-gdbinit
998 Control loading of init file (.gdbinit) from current directory.
1000 set auto-load libthread-db on|off
1001 show auto-load libthread-db
1002 Control auto-loading of inferior specific thread debugging shared library.
1004 set auto-load scripts-directory <dir1>[:<dir2>...]
1005 show auto-load scripts-directory
1006 Set a list of directories from which to load auto-loaded scripts.
1007 Automatically loaded Python scripts and GDB scripts are located in one
1008 of the directories listed by this option.
1009 The delimiter (':' above) may differ according to the host platform.
1011 set auto-load safe-path <dir1>[:<dir2>...]
1012 show auto-load safe-path
1013 Set a list of directories from which it is safe to auto-load files.
1014 The delimiter (':' above) may differ according to the host platform.
1016 set debug auto-load on|off
1017 show debug auto-load
1018 Control display of debugging info for auto-loading the files above.
1020 set dprintf-style gdb|call|agent
1022 Control the way in which a dynamic printf is performed; "gdb"
1023 requests a GDB printf command, while "call" causes dprintf to call a
1024 function in the inferior. "agent" requests that the target agent
1025 (such as GDBserver) do the printing.
1027 set dprintf-function <expr>
1028 show dprintf-function
1029 set dprintf-channel <expr>
1030 show dprintf-channel
1031 Set the function and optional first argument to the call when using
1032 the "call" style of dynamic printf.
1034 set disconnected-dprintf on|off
1035 show disconnected-dprintf
1036 Control whether agent-style dynamic printfs continue to be in effect
1037 after GDB disconnects.
1039 * New configure options
1041 --with-auto-load-dir
1042 Configure default value for the 'set auto-load scripts-directory'
1043 setting above. It defaults to '$debugdir:$datadir/auto-load',
1044 $debugdir representing global debugging info directories (available
1045 via 'show debug-file-directory') and $datadir representing GDB's data
1046 directory (available via 'show data-directory').
1048 --with-auto-load-safe-path
1049 Configure default value for the 'set auto-load safe-path' setting
1050 above. It defaults to the --with-auto-load-dir setting.
1052 --without-auto-load-safe-path
1053 Set 'set auto-load safe-path' to '/', effectively disabling this
1056 * New remote packets
1058 z0/z1 conditional breakpoints extension
1060 The z0/z1 breakpoint insertion packets have been extended to carry
1061 a list of conditional expressions over to the remote stub depending on the
1062 condition evaluation mode. The use of this extension can be controlled
1063 via the "set remote conditional-breakpoints-packet" command.
1067 Specify the signals which the remote stub may pass to the debugged
1068 program without GDB involvement.
1070 * New command line options
1072 --init-command=FILE, -ix Like --command, -x but execute it
1073 before loading inferior.
1074 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1075 execute it before loading inferior.
1077 *** Changes in GDB 7.4
1079 * GDB now handles ambiguous linespecs more consistently; the existing
1080 FILE:LINE support has been expanded to other types of linespecs. A
1081 breakpoint will now be set on all matching locations in all
1082 inferiors, and locations will be added or removed according to
1085 * GDB now allows you to skip uninteresting functions and files when
1086 stepping with the "skip function" and "skip file" commands.
1088 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1089 and "show remote hardware-watchpoint-length-limit". These allows to
1090 set or show the maximum length limit (in bytes) of a remote
1091 target hardware watchpoint.
1093 This allows e.g. to use "unlimited" hardware watchpoints with the
1094 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1095 watchpoints are slower than real hardware watchpoints but are
1096 significantly faster than gdb software watchpoints.
1100 ** The register_pretty_printer function in module gdb.printing now takes
1101 an optional `replace' argument. If True, the new printer replaces any
1104 ** The "maint set python print-stack on|off" command has been
1105 deprecated and will be deleted in GDB 7.5.
1106 A new command: "set python print-stack none|full|message" has
1107 replaced it. Additionally, the default for "print-stack" is
1108 now "message", which just prints the error message without
1111 ** A prompt substitution hook (prompt_hook) is now available to the
1114 ** A new Python module, gdb.prompt has been added to the GDB Python
1115 modules library. This module provides functionality for
1116 escape sequences in prompts (used by set/show
1117 extended-prompt). These escape sequences are replaced by their
1118 corresponding value.
1120 ** Python commands and convenience-functions located in
1121 'data-directory'/python/gdb/command and
1122 'data-directory'/python/gdb/function are now automatically loaded
1125 ** Blocks now provide four new attributes. global_block and
1126 static_block will return the global and static blocks
1127 respectively. is_static and is_global are boolean attributes
1128 that indicate if the block is one of those two types.
1130 ** Symbols now provide the "type" attribute, the type of the symbol.
1132 ** The "gdb.breakpoint" function has been deprecated in favor of
1135 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1136 of a function. This class is based on the "finish" command
1137 available in the CLI.
1139 ** Type objects for struct and union types now allow access to
1140 the fields using standard Python dictionary (mapping) methods.
1141 For example, "some_type['myfield']" now works, as does
1142 "some_type.items()".
1144 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1147 ** A new function, "deep_items" has been added to the gdb.types
1148 module in the GDB Python modules library. This function returns
1149 an iterator over the fields of a struct or union type. Unlike
1150 the standard Python "iteritems" method, it will recursively traverse
1151 any anonymous fields.
1155 ** "*stopped" events can report several new "reason"s, such as
1158 ** Breakpoint changes are now notified using new async records, like
1159 "=breakpoint-modified".
1161 ** New command -ada-task-info.
1163 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1164 $sdir specifies the default system locations of shared libraries.
1165 $pdir specifies the directory where the libpthread used by the application
1168 GDB no longer looks in $sdir and $pdir after it has searched the directories
1169 mentioned in libthread-db-search-path. If you want to search those
1170 directories, they must be specified in libthread-db-search-path.
1171 The default value of libthread-db-search-path on GNU/Linux and Solaris
1172 systems is now "$sdir:$pdir".
1174 $pdir is not supported by gdbserver, it is currently ignored.
1175 $sdir is supported by gdbserver.
1177 * New configure option --with-iconv-bin.
1178 When using the internationalization support like the one in the GNU C
1179 library, GDB will invoke the "iconv" program to get a list of supported
1180 character sets. If this program lives in a non-standard location, one can
1181 use this option to specify where to find it.
1183 * When natively debugging programs on PowerPC BookE processors running
1184 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1185 watchpoints, which specify a mask in addition to an address to watch.
1186 The mask specifies that some bits of an address (the bits which are
1187 reset in the mask) should be ignored when matching the address accessed
1188 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1189 section in the user manual for more details.
1191 * The new option --once causes GDBserver to stop listening for connections once
1192 the first connection is made. The listening port used by GDBserver will
1193 become available after that.
1195 * New commands "info macros" and "alias" have been added.
1197 * New function parameters suffix @entry specifies value of function parameter
1198 at the time the function got called. Entry values are available only since
1204 "!" is now an alias of the "shell" command.
1205 Note that no space is needed between "!" and SHELL COMMAND.
1209 watch EXPRESSION mask MASK_VALUE
1210 The watch command now supports the mask argument which allows creation
1211 of masked watchpoints, if the current architecture supports this feature.
1213 info auto-load-scripts [REGEXP]
1214 This command was formerly named "maintenance print section-scripts".
1215 It is now generally useful and is no longer a maintenance-only command.
1217 info macro [-all] [--] MACRO
1218 The info macro command has new options `-all' and `--'. The first for
1219 printing all definitions of a macro. The second for explicitly specifying
1220 the end of arguments and the beginning of the macro name in case the macro
1221 name starts with a hyphen.
1223 collect[/s] EXPRESSIONS
1224 The tracepoint collect command now takes an optional modifier "/s"
1225 that directs it to dereference pointer-to-character types and
1226 collect the bytes of memory up to a zero byte. The behavior is
1227 similar to what you see when you use the regular print command on a
1228 string. An optional integer following the "/s" sets a bound on the
1229 number of bytes that will be collected.
1232 The trace start command now interprets any supplied arguments as a
1233 note to be recorded with the trace run, with an effect similar to
1234 setting the variable trace-notes.
1237 The trace stop command now interprets any arguments as a note to be
1238 mentioned along with the tstatus report that the trace was stopped
1239 with a command. The effect is similar to setting the variable
1242 * Tracepoints can now be enabled and disabled at any time after a trace
1243 experiment has been started using the standard "enable" and "disable"
1244 commands. It is now possible to start a trace experiment with no enabled
1245 tracepoints; GDB will display a warning, but will allow the experiment to
1246 begin, assuming that tracepoints will be enabled as needed while the trace
1249 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1250 locations with 4-byte instructions, when they were previously
1251 limited to locations with instructions of 5 bytes or longer.
1255 set debug dwarf2-read
1256 show debug dwarf2-read
1257 Turns on or off display of debugging messages related to reading
1258 DWARF debug info. The default is off.
1260 set debug symtab-create
1261 show debug symtab-create
1262 Turns on or off display of debugging messages related to symbol table
1263 creation. The default is off.
1266 show extended-prompt
1267 Set the GDB prompt, and allow escape sequences to be inserted to
1268 display miscellaneous information (see 'help set extended-prompt'
1269 for the list of sequences). This prompt (and any information
1270 accessed through the escape sequences) is updated every time the
1271 prompt is displayed.
1273 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1274 show print entry-values
1275 Set printing of frame argument values at function entry. In some cases
1276 GDB can determine the value of function argument which was passed by the
1277 function caller, even if the value was modified inside the called function.
1279 set debug entry-values
1280 show debug entry-values
1281 Control display of debugging info for determining frame argument values at
1282 function entry and virtual tail call frames.
1284 set basenames-may-differ
1285 show basenames-may-differ
1286 Set whether a source file may have multiple base names.
1287 (A "base name" is the name of a file with the directory part removed.
1288 Example: The base name of "/home/user/hello.c" is "hello.c".)
1289 If set, GDB will canonicalize file names (e.g., expand symlinks)
1290 before comparing them. Canonicalization is an expensive operation,
1291 but it allows the same file be known by more than one base name.
1292 If not set (the default), all source files are assumed to have just
1293 one base name, and gdb will do file name comparisons more efficiently.
1299 Set a user name and notes for the current and any future trace runs.
1300 This is useful for long-running and/or disconnected traces, to
1301 inform others (or yourself) as to who is running the trace, supply
1302 contact information, or otherwise explain what is going on.
1304 set trace-stop-notes
1305 show trace-stop-notes
1306 Set a note attached to the trace run, that is displayed when the
1307 trace has been stopped by a tstop command. This is useful for
1308 instance as an explanation, if you are stopping a trace run that was
1309 started by someone else.
1311 * New remote packets
1315 Dynamically enable a tracepoint in a started trace experiment.
1319 Dynamically disable a tracepoint in a started trace experiment.
1323 Set the user and notes of the trace run.
1327 Query the current status of a tracepoint.
1331 Query the minimum length of instruction at which a fast tracepoint may
1334 * Dcache size (number of lines) and line-size are now runtime-configurable
1335 via "set dcache line" and "set dcache line-size" commands.
1339 Texas Instruments TMS320C6x tic6x-*-*
1343 Renesas RL78 rl78-*-elf
1345 *** Changes in GDB 7.3.1
1347 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1349 *** Changes in GDB 7.3
1351 * GDB has a new command: "thread find [REGEXP]".
1352 It finds the thread id whose name, target id, or thread extra info
1353 matches the given regular expression.
1355 * The "catch syscall" command now works on mips*-linux* targets.
1357 * The -data-disassemble MI command now supports modes 2 and 3 for
1358 dumping the instruction opcodes.
1360 * New command line options
1362 -data-directory DIR Specify DIR as the "data-directory".
1363 This is mostly for testing purposes.
1365 * The "maint set python auto-load on|off" command has been renamed to
1366 "set auto-load-scripts on|off".
1368 * GDB has a new command: "set directories".
1369 It is like the "dir" command except that it replaces the
1370 source path list instead of augmenting it.
1372 * GDB now understands thread names.
1374 On GNU/Linux, "info threads" will display the thread name as set by
1375 prctl or pthread_setname_np.
1377 There is also a new command, "thread name", which can be used to
1378 assign a name internally for GDB to display.
1381 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1382 has been integrated into GDB.
1386 ** The function gdb.Write now accepts an optional keyword 'stream'.
1387 This keyword, when provided, will direct the output to either
1388 stdout, stderr, or GDB's logging output.
1390 ** Parameters can now be be sub-classed in Python, and in particular
1391 you may implement the get_set_doc and get_show_doc functions.
1392 This improves how Parameter set/show documentation is processed
1393 and allows for more dynamic content.
1395 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1396 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1397 have an is_valid method.
1399 ** Breakpoints can now be sub-classed in Python, and in particular
1400 you may implement a 'stop' function that is executed each time
1401 the inferior reaches that breakpoint.
1403 ** New function gdb.lookup_global_symbol looks up a global symbol.
1405 ** GDB values in Python are now callable if the value represents a
1406 function. For example, if 'some_value' represents a function that
1407 takes two integer parameters and returns a value, you can call
1408 that function like so:
1410 result = some_value (10,20)
1412 ** Module gdb.types has been added.
1413 It contains a collection of utilities for working with gdb.Types objects:
1414 get_basic_type, has_field, make_enum_dict.
1416 ** Module gdb.printing has been added.
1417 It contains utilities for writing and registering pretty-printers.
1418 New classes: PrettyPrinter, SubPrettyPrinter,
1419 RegexpCollectionPrettyPrinter.
1420 New function: register_pretty_printer.
1422 ** New commands "info pretty-printers", "enable pretty-printer" and
1423 "disable pretty-printer" have been added.
1425 ** gdb.parameter("directories") is now available.
1427 ** New function gdb.newest_frame returns the newest frame in the
1430 ** The gdb.InferiorThread class has a new "name" attribute. This
1431 holds the thread's name.
1433 ** Python Support for Inferior events.
1434 Python scripts can add observers to be notified of events
1435 occurring in the process being debugged.
1436 The following events are currently supported:
1437 - gdb.events.cont Continue event.
1438 - gdb.events.exited Inferior exited event.
1439 - gdb.events.stop Signal received, and Breakpoint hit events.
1443 ** GDB now puts template parameters in scope when debugging in an
1444 instantiation. For example, if you have:
1446 template<int X> int func (void) { return X; }
1448 then if you step into func<5>, "print X" will show "5". This
1449 feature requires proper debuginfo support from the compiler; it
1450 was added to GCC 4.5.
1452 ** The motion commands "next", "finish", "until", and "advance" now
1453 work better when exceptions are thrown. In particular, GDB will
1454 no longer lose control of the inferior; instead, the GDB will
1455 stop the inferior at the point at which the exception is caught.
1456 This functionality requires a change in the exception handling
1457 code that was introduced in GCC 4.5.
1459 * GDB now follows GCC's rules on accessing volatile objects when
1460 reading or writing target state during expression evaluation.
1461 One notable difference to prior behavior is that "print x = 0"
1462 no longer generates a read of x; the value of the assignment is
1463 now always taken directly from the value being assigned.
1465 * GDB now has some support for using labels in the program's source in
1466 linespecs. For instance, you can use "advance label" to continue
1467 execution to a label.
1469 * GDB now has support for reading and writing a new .gdb_index
1470 section. This section holds a fast index of DWARF debugging
1471 information and can be used to greatly speed up GDB startup and
1472 operation. See the documentation for `save gdb-index' for details.
1474 * The "watch" command now accepts an optional "-location" argument.
1475 When used, this causes GDB to watch the memory referred to by the
1476 expression. Such a watchpoint is never deleted due to it going out
1479 * GDB now supports thread debugging of core dumps on GNU/Linux.
1481 GDB now activates thread debugging using the libthread_db library
1482 when debugging GNU/Linux core dumps, similarly to when debugging
1483 live processes. As a result, when debugging a core dump file, GDB
1484 is now able to display pthread_t ids of threads. For example, "info
1485 threads" shows the same output as when debugging the process when it
1486 was live. In earlier releases, you'd see something like this:
1489 * 1 LWP 6780 main () at main.c:10
1491 While now you see this:
1494 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1496 It is also now possible to inspect TLS variables when debugging core
1499 When debugging a core dump generated on a machine other than the one
1500 used to run GDB, you may need to point GDB at the correct
1501 libthread_db library with the "set libthread-db-search-path"
1502 command. See the user manual for more details on this command.
1504 * When natively debugging programs on PowerPC BookE processors running
1505 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1506 which stop execution of the inferior whenever it executes an instruction
1507 at any address within the specified range. See the "PowerPC Embedded"
1508 section in the user manual for more details.
1510 * New features in the GDB remote stub, GDBserver
1512 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1513 and i686 LynxOS (version 5.x).
1515 ** GDBserver is now supported on Blackfin Linux.
1517 * New native configurations
1519 ia64 HP-UX ia64-*-hpux*
1523 Analog Devices, Inc. Blackfin Processor bfin-*
1525 * Ada task switching is now supported on sparc-elf targets when
1526 debugging a program using the Ravenscar Profile. For more information,
1527 see the "Tasking Support when using the Ravenscar Profile" section
1528 in the GDB user manual.
1530 * Guile support was removed.
1532 * New features in the GNU simulator
1534 ** The --map-info flag lists all known core mappings.
1536 ** CFI flashes may be simulated via the "cfi" device.
1538 *** Changes in GDB 7.2
1540 * Shared library support for remote targets by default
1542 When GDB is configured for a generic, non-OS specific target, like
1543 for example, --target=arm-eabi or one of the many *-*-elf targets,
1544 GDB now queries remote stubs for loaded shared libraries using the
1545 `qXfer:libraries:read' packet. Previously, shared library support
1546 was always disabled for such configurations.
1550 ** Argument Dependent Lookup (ADL)
1552 In C++ ADL lookup directs function search to the namespaces of its
1553 arguments even if the namespace has not been imported.
1563 Here the compiler will search for `foo' in the namespace of 'b'
1564 and find A::foo. GDB now supports this. This construct is commonly
1565 used in the Standard Template Library for operators.
1567 ** Improved User Defined Operator Support
1569 In addition to member operators, GDB now supports lookup of operators
1570 defined in a namespace and imported with a `using' directive, operators
1571 defined in the global scope, operators imported implicitly from an
1572 anonymous namespace, and the ADL operators mentioned in the previous
1574 GDB now also supports proper overload resolution for all the previously
1575 mentioned flavors of operators.
1577 ** static const class members
1579 Printing of static const class members that are initialized in the
1580 class definition has been fixed.
1582 * Windows Thread Information Block access.
1584 On Windows targets, GDB now supports displaying the Windows Thread
1585 Information Block (TIB) structure. This structure is visible either
1586 by using the new command `info w32 thread-information-block' or, by
1587 dereferencing the new convenience variable named `$_tlb', a
1588 thread-specific pointer to the TIB. This feature is also supported
1589 when remote debugging using GDBserver.
1591 * Static tracepoints
1593 Static tracepoints are calls in the user program into a tracing
1594 library. One such library is a port of the LTTng kernel tracer to
1595 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1596 When debugging with GDBserver, GDB now supports combining the GDB
1597 tracepoint machinery with such libraries. For example: the user can
1598 use GDB to probe a static tracepoint marker (a call from the user
1599 program into the tracing library) with the new "strace" command (see
1600 "New commands" below). This creates a "static tracepoint" in the
1601 breakpoint list, that can be manipulated with the same feature set
1602 as fast and regular tracepoints. E.g., collect registers, local and
1603 global variables, collect trace state variables, and define
1604 tracepoint conditions. In addition, the user can collect extra
1605 static tracepoint marker specific data, by collecting the new
1606 $_sdata internal variable. When analyzing the trace buffer, you can
1607 inspect $_sdata like any other variable available to GDB. For more
1608 information, see the "Tracepoints" chapter in GDB user manual. New
1609 remote packets have been defined to support static tracepoints, see
1610 the "New remote packets" section below.
1612 * Better reconstruction of tracepoints after disconnected tracing
1614 GDB will attempt to download the original source form of tracepoint
1615 definitions when starting a trace run, and then will upload these
1616 upon reconnection to the target, resulting in a more accurate
1617 reconstruction of the tracepoints that are in use on the target.
1621 You can now exercise direct control over the ways that GDB can
1622 affect your program. For instance, you can disallow the setting of
1623 breakpoints, so that the program can run continuously (assuming
1624 non-stop mode). In addition, the "observer" variable is available
1625 to switch all of the different controls; in observer mode, GDB
1626 cannot affect the target's behavior at all, which is useful for
1627 tasks like diagnosing live systems in the field.
1629 * The new convenience variable $_thread holds the number of the
1632 * New remote packets
1636 Return the address of the Windows Thread Information Block of a given thread.
1640 In response to several of the tracepoint packets, the target may now
1641 also respond with a number of intermediate `qRelocInsn' request
1642 packets before the final result packet, to have GDB handle
1643 relocating an instruction to execute at a different address. This
1644 is particularly useful for stubs that support fast tracepoints. GDB
1645 reports support for this feature in the qSupported packet.
1649 List static tracepoint markers in the target program.
1653 List static tracepoint markers at a given address in the target
1656 qXfer:statictrace:read
1658 Read the static trace data collected (by a `collect $_sdata'
1659 tracepoint action). The remote stub reports support for this packet
1660 to gdb's qSupported query.
1664 Send the current settings of GDB's permission flags.
1668 Send part of the source (textual) form of a tracepoint definition,
1669 which includes location, conditional, and action list.
1671 * The source command now accepts a -s option to force searching for the
1672 script in the source search path even if the script name specifies
1675 * New features in the GDB remote stub, GDBserver
1677 - GDBserver now support tracepoints (including fast tracepoints, and
1678 static tracepoints). The feature is currently supported by the
1679 i386-linux and amd64-linux builds. See the "Tracepoints support
1680 in gdbserver" section in the manual for more information.
1682 GDBserver JIT compiles the tracepoint's conditional agent
1683 expression bytecode into native code whenever possible for low
1684 overhead dynamic tracepoints conditionals. For such tracepoints,
1685 an expression that examines program state is evaluated when the
1686 tracepoint is reached, in order to determine whether to capture
1687 trace data. If the condition is simple and false, processing the
1688 tracepoint finishes very quickly and no data is gathered.
1690 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1691 for static tracepoints support.
1693 - GDBserver now supports x86_64 Windows 64-bit debugging.
1695 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1696 it understands register description.
1698 * The --batch flag now disables pagination and queries.
1700 * X86 general purpose registers
1702 GDB now supports reading/writing byte, word and double-word x86
1703 general purpose registers directly. This means you can use, say,
1704 $ah or $ax to refer, respectively, to the byte register AH and
1705 16-bit word register AX that are actually portions of the 32-bit
1706 register EAX or 64-bit register RAX.
1708 * The `commands' command now accepts a range of breakpoints to modify.
1709 A plain `commands' following a command that creates multiple
1710 breakpoints affects all the breakpoints set by that command. This
1711 applies to breakpoints set by `rbreak', and also applies when a
1712 single `break' command creates multiple breakpoints (e.g.,
1713 breakpoints on overloaded c++ functions).
1715 * The `rbreak' command now accepts a filename specification as part of
1716 its argument, limiting the functions selected by the regex to those
1717 in the specified file.
1719 * Support for remote debugging Windows and SymbianOS shared libraries
1720 from Unix hosts has been improved. Non Windows GDB builds now can
1721 understand target reported file names that follow MS-DOS based file
1722 system semantics, such as file names that include drive letters and
1723 use the backslash character as directory separator. This makes it
1724 possible to transparently use the "set sysroot" and "set
1725 solib-search-path" on Unix hosts to point as host copies of the
1726 target's shared libraries. See the new command "set
1727 target-file-system-kind" described below, and the "Commands to
1728 specify files" section in the user manual for more information.
1732 eval template, expressions...
1733 Convert the values of one or more expressions under the control
1734 of the string template to a command line, and call it.
1736 set target-file-system-kind unix|dos-based|auto
1737 show target-file-system-kind
1738 Set or show the assumed file system kind for target reported file
1741 save breakpoints <filename>
1742 Save all current breakpoint definitions to a file suitable for use
1743 in a later debugging session. To read the saved breakpoint
1744 definitions, use the `source' command.
1746 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1749 info static-tracepoint-markers
1750 Display information about static tracepoint markers in the target.
1752 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1753 Define a static tracepoint by probing a marker at the given
1754 function, line, address, or marker ID.
1758 Enable and disable observer mode.
1760 set may-write-registers on|off
1761 set may-write-memory on|off
1762 set may-insert-breakpoints on|off
1763 set may-insert-tracepoints on|off
1764 set may-insert-fast-tracepoints on|off
1765 set may-interrupt on|off
1766 Set individual permissions for GDB effects on the target. Note that
1767 some of these settings can have undesirable or surprising
1768 consequences, particularly when changed in the middle of a session.
1769 For instance, disabling the writing of memory can prevent
1770 breakpoints from being inserted, cause single-stepping to fail, or
1771 even crash your program, if you disable after breakpoints have been
1772 inserted. However, GDB should not crash.
1774 set record memory-query on|off
1775 show record memory-query
1776 Control whether to stop the inferior if memory changes caused
1777 by an instruction cannot be recorded.
1782 The disassemble command now supports "start,+length" form of two arguments.
1786 ** GDB now provides a new directory location, called the python directory,
1787 where Python scripts written for GDB can be installed. The location
1788 of that directory is <data-directory>/python, where <data-directory>
1789 is the GDB data directory. For more details, see section `Scripting
1790 GDB using Python' in the manual.
1792 ** The GDB Python API now has access to breakpoints, symbols, symbol
1793 tables, program spaces, inferiors, threads and frame's code blocks.
1794 Additionally, GDB Parameters can now be created from the API, and
1795 manipulated via set/show in the CLI.
1797 ** New functions gdb.target_charset, gdb.target_wide_charset,
1798 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1800 ** New exception gdb.GdbError.
1802 ** Pretty-printers are now also looked up in the current program space.
1804 ** Pretty-printers can now be individually enabled and disabled.
1806 ** GDB now looks for names of Python scripts to auto-load in a
1807 special section named `.debug_gdb_scripts', in addition to looking
1808 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1810 * Tracepoint actions were unified with breakpoint commands. In particular,
1811 there are no longer differences in "info break" output for breakpoints and
1812 tracepoints and the "commands" command can be used for both tracepoints and
1813 regular breakpoints.
1817 ARM Symbian arm*-*-symbianelf*
1819 * D language support.
1820 GDB now supports debugging programs written in the D programming
1823 * GDB now supports the extended ptrace interface for PowerPC which is
1824 available since Linux kernel version 2.6.34. This automatically enables
1825 any hardware breakpoints and additional hardware watchpoints available in
1826 the processor. The old ptrace interface exposes just one hardware
1827 watchpoint and no hardware breakpoints.
1829 * GDB is now able to use the Data Value Compare (DVC) register available on
1830 embedded PowerPC processors to implement in hardware simple watchpoint
1831 conditions of the form:
1833 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1835 This works in native GDB running on Linux kernels with the extended ptrace
1836 interface mentioned above.
1838 *** Changes in GDB 7.1
1842 ** Namespace Support
1844 GDB now supports importing of namespaces in C++. This enables the
1845 user to inspect variables from imported namespaces. Support for
1846 namepace aliasing has also been added. So, if a namespace is
1847 aliased in the current scope (e.g. namepace C=A; ) the user can
1848 print variables using the alias (e.g. (gdb) print C::x).
1852 All known bugs relating to the printing of virtual base class were
1853 fixed. It is now possible to call overloaded static methods using a
1858 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1859 and reinterpret_cast<> are now handled by the C++ expression parser.
1863 Xilinx MicroBlaze microblaze-*-*
1868 Xilinx MicroBlaze microblaze
1871 * Multi-program debugging.
1873 GDB now has support for multi-program (a.k.a. multi-executable or
1874 multi-exec) debugging. This allows for debugging multiple inferiors
1875 simultaneously each running a different program under the same GDB
1876 session. See "Debugging Multiple Inferiors and Programs" in the
1877 manual for more information. This implied some user visible changes
1878 in the multi-inferior support. For example, "info inferiors" now
1879 lists inferiors that are not running yet or that have exited
1880 already. See also "New commands" and "New options" below.
1882 * New tracing features
1884 GDB's tracepoint facility now includes several new features:
1886 ** Trace state variables
1888 GDB tracepoints now include support for trace state variables, which
1889 are variables managed by the target agent during a tracing
1890 experiment. They are useful for tracepoints that trigger each
1891 other, so for instance one tracepoint can count hits in a variable,
1892 and then a second tracepoint has a condition that is true when the
1893 count reaches a particular value. Trace state variables share the
1894 $-syntax of GDB convenience variables, and can appear in both
1895 tracepoint actions and condition expressions. Use the "tvariable"
1896 command to create, and "info tvariables" to view; see "Trace State
1897 Variables" in the manual for more detail.
1901 GDB now includes an option for defining fast tracepoints, which
1902 targets may implement more efficiently, such as by installing a jump
1903 into the target agent rather than a trap instruction. The resulting
1904 speedup can be by two orders of magnitude or more, although the
1905 tradeoff is that some program locations on some target architectures
1906 might not allow fast tracepoint installation, for instance if the
1907 instruction to be replaced is shorter than the jump. To request a
1908 fast tracepoint, use the "ftrace" command, with syntax identical to
1909 the regular trace command.
1911 ** Disconnected tracing
1913 It is now possible to detach GDB from the target while it is running
1914 a trace experiment, then reconnect later to see how the experiment
1915 is going. In addition, a new variable disconnected-tracing lets you
1916 tell the target agent whether to continue running a trace if the
1917 connection is lost unexpectedly.
1921 GDB now has the ability to save the trace buffer into a file, and
1922 then use that file as a target, similarly to you can do with
1923 corefiles. You can select trace frames, print data that was
1924 collected in them, and use tstatus to display the state of the
1925 tracing run at the moment that it was saved. To create a trace
1926 file, use "tsave <filename>", and to use it, do "target tfile
1929 ** Circular trace buffer
1931 You can ask the target agent to handle the trace buffer as a
1932 circular buffer, discarding the oldest trace frames to make room for
1933 newer ones, by setting circular-trace-buffer to on. This feature may
1934 not be available for all target agents.
1939 The disassemble command, when invoked with two arguments, now requires
1940 the arguments to be comma-separated.
1943 The info variables command now displays variable definitions. Files
1944 which only declare a variable are not shown.
1947 The source command is now capable of sourcing Python scripts.
1948 This feature is dependent on the debugger being build with Python
1951 Related to this enhancement is also the introduction of a new command
1952 "set script-extension" (see below).
1954 * New commands (for set/show, see "New options" below)
1956 record save [<FILENAME>]
1957 Save a file (in core file format) containing the process record
1958 execution log for replay debugging at a later time.
1960 record restore <FILENAME>
1961 Restore the process record execution log that was saved at an
1962 earlier time, for replay debugging.
1964 add-inferior [-copies <N>] [-exec <FILENAME>]
1967 clone-inferior [-copies <N>] [ID]
1968 Make a new inferior ready to execute the same program another
1969 inferior has loaded.
1974 maint info program-spaces
1975 List the program spaces loaded into GDB.
1977 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1978 show remote interrupt-sequence
1979 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1980 as the sequence to the remote target in order to interrupt the execution.
1981 Ctrl-C is a default. Some system prefers BREAK which is high level of
1982 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1983 Magic SysRq g. It is BREAK signal and character 'g'.
1985 set remote interrupt-on-connect [on | off]
1986 show remote interrupt-on-connect
1987 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1988 remote target when gdb connects to it. This is needed when you debug
1991 set remotebreak [on | off]
1993 Deprecated. Use "set/show remote interrupt-sequence" instead.
1995 tvariable $NAME [ = EXP ]
1996 Create or modify a trace state variable.
1999 List trace state variables and their values.
2001 delete tvariable $NAME ...
2002 Delete one or more trace state variables.
2005 Evaluate the given expressions without collecting anything into the
2006 trace buffer. (Valid in tracepoint actions only.)
2008 ftrace FN / FILE:LINE / *ADDR
2009 Define a fast tracepoint at the given function, line, or address.
2011 * New expression syntax
2013 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2014 GDB now parses 0b101010 identically with 42.
2018 set follow-exec-mode new|same
2019 show follow-exec-mode
2020 Control whether GDB reuses the same inferior across an exec call or
2021 creates a new one. This is useful to be able to restart the old
2022 executable after the inferior having done an exec call.
2024 set default-collect EXPR, ...
2025 show default-collect
2026 Define a list of expressions to be collected at each tracepoint.
2027 This is a useful way to ensure essential items are not overlooked,
2028 such as registers or a critical global variable.
2030 set disconnected-tracing
2031 show disconnected-tracing
2032 If set to 1, the target is instructed to continue tracing if it
2033 loses its connection to GDB. If 0, the target is to stop tracing
2036 set circular-trace-buffer
2037 show circular-trace-buffer
2038 If set to on, the target is instructed to use a circular trace buffer
2039 and discard the oldest trace frames instead of stopping the trace due
2040 to a full trace buffer. If set to off, the trace stops when the buffer
2041 fills up. Some targets may not support this.
2043 set script-extension off|soft|strict
2044 show script-extension
2045 If set to "off", the debugger does not perform any script language
2046 recognition, and all sourced files are assumed to be GDB scripts.
2047 If set to "soft" (the default), files are sourced according to
2048 filename extension, falling back to GDB scripts if the first
2050 If set to "strict", files are sourced according to filename extension.
2052 set ada trust-PAD-over-XVS on|off
2053 show ada trust-PAD-over-XVS
2054 If off, activate a workaround against a bug in the debugging information
2055 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2056 the GCC sources for more information about the GNAT encoding and
2057 PAD types in particular). It is always safe to set this option to
2058 off, but this introduces a slight performance penalty. The default
2061 * Python API Improvements
2063 ** GDB provides the new class gdb.LazyString. This is useful in
2064 some pretty-printing cases. The new method gdb.Value.lazy_string
2065 provides a simple way to create objects of this type.
2067 ** The fields returned by gdb.Type.fields now have an
2068 `is_base_class' attribute.
2070 ** The new method gdb.Type.range returns the range of an array type.
2072 ** The new method gdb.parse_and_eval can be used to parse and
2073 evaluate an expression.
2075 * New remote packets
2078 Define a trace state variable.
2081 Get the current value of a trace state variable.
2084 Set desired tracing behavior upon disconnection.
2087 Set the trace buffer to be linear or circular.
2090 Get data about the tracepoints currently in use.
2094 Process record now works correctly with hardware watchpoints.
2096 Multiple bug fixes have been made to the mips-irix port, making it
2097 much more reliable. In particular:
2098 - Debugging threaded applications is now possible again. Previously,
2099 GDB would hang while starting the program, or while waiting for
2100 the program to stop at a breakpoint.
2101 - Attaching to a running process no longer hangs.
2102 - An error occurring while loading a core file has been fixed.
2103 - Changing the value of the PC register now works again. This fixes
2104 problems observed when using the "jump" command, or when calling
2105 a function from GDB, or even when assigning a new value to $pc.
2106 - With the "finish" and "return" commands, the return value for functions
2107 returning a small array is now correctly printed.
2108 - It is now possible to break on shared library code which gets executed
2109 during a shared library init phase (code executed while executing
2110 their .init section). Previously, the breakpoint would have no effect.
2111 - GDB is now able to backtrace through the signal handler for
2112 non-threaded programs.
2114 PIE (Position Independent Executable) programs debugging is now supported.
2115 This includes debugging execution of PIC (Position Independent Code) shared
2116 libraries although for that, it should be possible to run such libraries as an
2119 *** Changes in GDB 7.0
2121 * GDB now has an interface for JIT compilation. Applications that
2122 dynamically generate code can create symbol files in memory and register
2123 them with GDB. For users, the feature should work transparently, and
2124 for JIT developers, the interface is documented in the GDB manual in the
2125 "JIT Compilation Interface" chapter.
2127 * Tracepoints may now be conditional. The syntax is as for
2128 breakpoints; either an "if" clause appended to the "trace" command,
2129 or the "condition" command is available. GDB sends the condition to
2130 the target for evaluation using the same bytecode format as is used
2131 for tracepoint actions.
2133 * The disassemble command now supports: an optional /r modifier, print the
2134 raw instructions in hex as well as in symbolic form, and an optional /m
2135 modifier to print mixed source+assembly.
2137 * Process record and replay
2139 In a architecture environment that supports ``process record and
2140 replay'', ``process record and replay'' target can record a log of
2141 the process execution, and replay it with both forward and reverse
2144 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2145 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2146 set execution-direction {forward|reverse}, for targets that support
2149 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2150 feature is available with a native GDB running on kernel version
2153 * GDB now has support for multi-byte and wide character sets on the
2154 target. Strings whose character type is wchar_t, char16_t, or
2155 char32_t are now correctly printed. GDB supports wide- and unicode-
2156 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2157 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2158 `printf'. This feature requires iconv to work properly; if your
2159 system does not have a working iconv, GDB can use GNU libiconv. See
2160 the installation instructions for more information.
2162 * GDB now supports automatic retrieval of shared library files from
2163 remote targets. To use this feature, specify a system root that begins
2164 with the `remote:' prefix, either via the `set sysroot' command or via
2165 the `--with-sysroot' configure-time option.
2167 * "info sharedlibrary" now takes an optional regex of libraries to show,
2168 and it now reports if a shared library has no debugging information.
2170 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2171 now complete on file names.
2173 * When completing in expressions, gdb will attempt to limit
2174 completions to allowable structure or union fields, where appropriate.
2175 For instance, consider:
2177 # struct example { int f1; double f2; };
2178 # struct example variable;
2181 If the user types TAB at the end of this command line, the available
2182 completions will be "f1" and "f2".
2184 * Inlined functions are now supported. They show up in backtraces, and
2185 the "step", "next", and "finish" commands handle them automatically.
2187 * GDB now supports the token-splicing (##) and stringification (#)
2188 operators when expanding macros. It also supports variable-arity
2191 * GDB now supports inspecting extra signal information, exported by
2192 the new $_siginfo convenience variable. The feature is currently
2193 implemented on linux ARM, i386 and amd64.
2195 * GDB can now display the VFP floating point registers and NEON vector
2196 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2197 can provide these registers (requires Linux 2.6.30 or later). Remote
2198 and simulator targets may also provide them.
2200 * New remote packets
2203 Search memory for a sequence of bytes.
2206 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2207 operation over reliable transport links. Use of this packet is
2208 controlled by the `set remote noack-packet' command.
2211 Kill the process with the specified process ID. Use this in preference
2212 to `k' when multiprocess protocol extensions are supported.
2215 Obtains additional operating system information
2219 Read or write additional signal information.
2221 * Removed remote protocol undocumented extension
2223 An undocumented extension to the remote protocol's `S' stop reply
2224 packet that permited the stub to pass a process id was removed.
2225 Remote servers should use the `T' stop reply packet instead.
2227 * GDB now supports multiple function calling conventions according to the
2228 DWARF-2 DW_AT_calling_convention function attribute.
2230 * The SH target utilizes the aforementioned change to distinguish between gcc
2231 and Renesas calling convention. It also adds the new CLI commands
2232 `set/show sh calling-convention'.
2234 * GDB can now read compressed debug sections, as produced by GNU gold
2235 with the --compress-debug-sections=zlib flag.
2237 * 64-bit core files are now supported on AIX.
2239 * Thread switching is now supported on Tru64.
2241 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2242 which will be allocated using malloc later in program execution.
2244 * The qXfer:libraries:read remote procotol packet now allows passing a
2245 list of section offsets.
2247 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2248 conditions handling signals delivered during attach or thread creation
2249 have also been fixed.
2251 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2252 From the user's standpoint, all unqualified instances of True and False
2253 are treated as the standard definitions, regardless of context.
2255 * GDB now parses C++ symbol and type names more flexibly. For
2258 template<typename T> class C { };
2261 GDB will now correctly handle all of:
2263 ptype C<char const *>
2264 ptype C<char const*>
2265 ptype C<const char *>
2266 ptype C<const char*>
2268 * New features in the GDB remote stub, gdbserver
2270 - The "--wrapper" command-line argument tells gdbserver to use a
2271 wrapper program to launch programs for debugging.
2273 - On PowerPC and S/390 targets, it is now possible to use a single
2274 gdbserver executable to debug both 32-bit and 64-bit programs.
2275 (This requires gdbserver itself to be built as a 64-bit executable.)
2277 - gdbserver uses the new noack protocol mode for TCP connections to
2278 reduce communications latency, if also supported and enabled in GDB.
2280 - Support for the sparc64-linux-gnu target is now included in
2283 - The amd64-linux build of gdbserver now supports debugging both
2284 32-bit and 64-bit programs.
2286 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2287 now support hardware watchpoints, and will use them automatically
2292 GDB now has support for scripting using Python. Whether this is
2293 available is determined at configure time.
2295 New GDB commands can now be written in Python.
2297 * Ada tasking support
2299 Ada tasks can now be inspected in GDB. The following commands have
2303 Print the list of Ada tasks.
2305 Print detailed information about task number N.
2307 Print the task number of the current task.
2309 Switch the context of debugging to task number N.
2311 * Support for user-defined prefixed commands. The "define" command can
2312 add new commands to existing prefixes, e.g. "target".
2314 * Multi-inferior, multi-process debugging.
2316 GDB now has generalized support for multi-inferior debugging. See
2317 "Debugging Multiple Inferiors" in the manual for more information.
2318 Although availability still depends on target support, the command
2319 set is more uniform now. The GNU/Linux specific multi-forks support
2320 has been migrated to this new framework. This implied some user
2321 visible changes; see "New commands" and also "Removed commands"
2324 * Target descriptions can now describe the target OS ABI. See the
2325 "Target Description Format" section in the user manual for more
2328 * Target descriptions can now describe "compatible" architectures
2329 to indicate that the target can execute applications for a different
2330 architecture in addition to those for the main target architecture.
2331 See the "Target Description Format" section in the user manual for
2334 * Multi-architecture debugging.
2336 GDB now includes general supports for debugging applications on
2337 hybrid systems that use more than one single processor architecture
2338 at the same time. Each such hybrid architecture still requires
2339 specific support to be added. The only hybrid architecture supported
2340 in this version of GDB is the Cell Broadband Engine.
2342 * GDB now supports integrated debugging of Cell/B.E. applications that
2343 use both the PPU and SPU architectures. To enable support for hybrid
2344 Cell/B.E. debugging, you need to configure GDB to support both the
2345 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2346 --enable-targets configure option.
2348 * Non-stop mode debugging.
2350 For some targets, GDB now supports an optional mode of operation in
2351 which you can examine stopped threads while other threads continue
2352 to execute freely. This is referred to as non-stop mode, with the
2353 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2354 section in the user manual for more information.
2356 To be able to support remote non-stop debugging, a remote stub needs
2357 to implement the non-stop mode remote protocol extensions, as
2358 described in the "Remote Non-Stop" section of the user manual. The
2359 GDB remote stub, gdbserver, has been adjusted to support these
2360 extensions on linux targets.
2362 * New commands (for set/show, see "New options" below)
2364 catch syscall [NAME(S) | NUMBER(S)]
2365 Catch system calls. Arguments, which should be names of system
2366 calls or their numbers, mean catch only those syscalls. Without
2367 arguments, every syscall will be caught. When the inferior issues
2368 any of the specified syscalls, GDB will stop and announce the system
2369 call, both when it is called and when its call returns. This
2370 feature is currently available with a native GDB running on the
2371 Linux Kernel, under the following architectures: x86, x86_64,
2372 PowerPC and PowerPC64.
2374 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2376 Search memory for a sequence of bytes.
2378 maint set python print-stack
2379 maint show python print-stack
2380 Show a stack trace when an error is encountered in a Python script.
2383 Invoke CODE by passing it to the Python interpreter.
2388 These allow macros to be defined, undefined, and listed
2392 Show operating system information about processes.
2395 List the inferiors currently under GDB's control.
2398 Switch focus to inferior number NUM.
2401 Detach from inferior number NUM.
2404 Kill inferior number NUM.
2408 set spu stop-on-load
2409 show spu stop-on-load
2410 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2412 set spu auto-flush-cache
2413 show spu auto-flush-cache
2414 Control whether to automatically flush the software-managed cache
2415 during Cell/B.E. debugging.
2417 set sh calling-convention
2418 show sh calling-convention
2419 Control the calling convention used when calling SH target functions.
2422 show debug timestamp
2423 Control display of timestamps with GDB debugging output.
2425 set disassemble-next-line
2426 show disassemble-next-line
2427 Control display of disassembled source lines or instructions when
2430 set remote noack-packet
2431 show remote noack-packet
2432 Set/show the use of remote protocol QStartNoAckMode packet. See above
2433 under "New remote packets."
2435 set remote query-attached-packet
2436 show remote query-attached-packet
2437 Control use of remote protocol `qAttached' (query-attached) packet.
2439 set remote read-siginfo-object
2440 show remote read-siginfo-object
2441 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2444 set remote write-siginfo-object
2445 show remote write-siginfo-object
2446 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2449 set remote reverse-continue
2450 show remote reverse-continue
2451 Control use of remote protocol 'bc' (reverse-continue) packet.
2453 set remote reverse-step
2454 show remote reverse-step
2455 Control use of remote protocol 'bs' (reverse-step) packet.
2457 set displaced-stepping
2458 show displaced-stepping
2459 Control displaced stepping mode. Displaced stepping is a way to
2460 single-step over breakpoints without removing them from the debuggee.
2461 Also known as "out-of-line single-stepping".
2464 show debug displaced
2465 Control display of debugging info for displaced stepping.
2467 maint set internal-error
2468 maint show internal-error
2469 Control what GDB does when an internal error is detected.
2471 maint set internal-warning
2472 maint show internal-warning
2473 Control what GDB does when an internal warning is detected.
2478 Use a wrapper program to launch programs for debugging.
2480 set multiple-symbols (all|ask|cancel)
2481 show multiple-symbols
2482 The value of this variable can be changed to adjust the debugger behavior
2483 when an expression or a breakpoint location contains an ambiguous symbol
2484 name (an overloaded function name, for instance).
2486 set breakpoint always-inserted
2487 show breakpoint always-inserted
2488 Keep breakpoints always inserted in the target, as opposed to inserting
2489 them when resuming the target, and removing them when the target stops.
2490 This option can improve debugger performance on slow remote targets.
2492 set arm fallback-mode (arm|thumb|auto)
2493 show arm fallback-mode
2494 set arm force-mode (arm|thumb|auto)
2496 These commands control how ARM GDB determines whether instructions
2497 are ARM or Thumb. The default for both settings is auto, which uses
2498 the current CPSR value for instructions without symbols; previous
2499 versions of GDB behaved as if "set arm fallback-mode arm".
2501 set disable-randomization
2502 show disable-randomization
2503 Standalone programs run with the virtual address space randomization enabled
2504 by default on some platforms. This option keeps the addresses stable across
2505 multiple debugging sessions.
2509 Control whether other threads are stopped or not when some thread hits
2514 Requests that asynchronous execution is enabled in the target, if available.
2515 In this case, it's possible to resume target in the background, and interact
2516 with GDB while the target is running. "show target-async" displays the
2517 current state of asynchronous execution of the target.
2519 set target-wide-charset
2520 show target-wide-charset
2521 The target-wide-charset is the name of the character set that GDB
2522 uses when printing characters whose type is wchar_t.
2524 set tcp auto-retry (on|off)
2526 set tcp connect-timeout
2527 show tcp connect-timeout
2528 These commands allow GDB to retry failed TCP connections to a remote stub
2529 with a specified timeout period; this is useful if the stub is launched
2530 in parallel with GDB but may not be ready to accept connections immediately.
2532 set libthread-db-search-path
2533 show libthread-db-search-path
2534 Control list of directories which GDB will search for appropriate
2537 set schedule-multiple (on|off)
2538 show schedule-multiple
2539 Allow GDB to resume all threads of all processes or only threads of
2540 the current process.
2544 Use more aggressive caching for accesses to the stack. This improves
2545 performance of remote debugging (particularly backtraces) without
2546 affecting correctness.
2548 set interactive-mode (on|off|auto)
2549 show interactive-mode
2550 Control whether GDB runs in interactive mode (on) or not (off).
2551 When in interactive mode, GDB waits for the user to answer all
2552 queries. Otherwise, GDB does not wait and assumes the default
2553 answer. When set to auto (the default), GDB determines which
2554 mode to use based on the stdin settings.
2559 For program forks, this is replaced by the new more generic `info
2560 inferiors' command. To list checkpoints, you can still use the
2561 `info checkpoints' command, which was an alias for the `info forks'
2565 Replaced by the new `inferior' command. To switch between
2566 checkpoints, you can still use the `restart' command, which was an
2567 alias for the `fork' command.
2570 This is removed, since some targets don't have a notion of
2571 processes. To switch between processes, you can still use the
2572 `inferior' command using GDB's own inferior number.
2575 For program forks, this is replaced by the new more generic `kill
2576 inferior' command. To delete a checkpoint, you can still use the
2577 `delete checkpoint' command, which was an alias for the `delete
2581 For program forks, this is replaced by the new more generic `detach
2582 inferior' command. To detach a checkpoint, you can still use the
2583 `detach checkpoint' command, which was an alias for the `detach
2586 * New native configurations
2588 x86/x86_64 Darwin i[34567]86-*-darwin*
2590 x86_64 MinGW x86_64-*-mingw*
2594 Lattice Mico32 lm32-*
2595 x86 DICOS i[34567]86-*-dicos*
2596 x86_64 DICOS x86_64-*-dicos*
2599 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2600 (mingw32ce) debugging.
2606 These commands were actually not implemented on any target.
2608 *** Changes in GDB 6.8
2610 * New native configurations
2612 NetBSD/hppa hppa*-*netbsd*
2613 Xtensa GNU/Linux xtensa*-*-linux*
2617 NetBSD/hppa hppa*-*-netbsd*
2618 Xtensa GNU/Lunux xtensa*-*-linux*
2620 * Change in command line behavior -- corefiles vs. process ids.
2622 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2623 attaching to process NUMBER fails, GDB no longer attempts to open a
2624 core file named NUMBER. Attaching to a program using the -c option
2625 is no longer supported. Instead, use the '-p' or '--pid' options.
2627 * GDB can now be built as a native debugger for debugging Windows x86
2628 (mingw32) Portable Executable (PE) programs.
2630 * Pending breakpoints no longer change their number when their address
2633 * GDB now supports breakpoints with multiple locations,
2634 including breakpoints on C++ constructors, inside C++ templates,
2635 and in inlined functions.
2637 * GDB's ability to debug optimized code has been improved. GDB more
2638 accurately identifies function bodies and lexical blocks that occupy
2639 more than one contiguous range of addresses.
2641 * Target descriptions can now describe registers for PowerPC.
2643 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2644 registers on PowerPC targets.
2646 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2647 targets even when the libthread_db library is not available.
2649 * The GDB remote stub, gdbserver, now supports the new file transfer
2650 commands (remote put, remote get, and remote delete).
2652 * The GDB remote stub, gdbserver, now supports run and attach in
2653 extended-remote mode.
2655 * hppa*64*-*-hpux11* target broken
2656 The debugger is unable to start a program and fails with the following
2657 error: "Error trying to get information about dynamic linker".
2658 The gdb-6.7 release is also affected.
2660 * GDB now supports the --enable-targets= configure option to allow
2661 building a single GDB executable that supports multiple remote
2662 target architectures.
2664 * GDB now supports debugging C and C++ programs which use the
2665 Decimal Floating Point extension. In addition, the PowerPC target
2666 now has a set of pseudo-registers to inspect decimal float values
2667 stored in two consecutive float registers.
2669 * The -break-insert MI command can optionally create pending
2672 * Improved support for debugging Ada
2673 Many improvements to the Ada language support have been made. These
2675 - Better support for Ada2005 interface types
2676 - Improved handling of arrays and slices in general
2677 - Better support for Taft-amendment types
2678 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2680 - Improved command completion in Ada
2683 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2688 set print frame-arguments (all|scalars|none)
2689 show print frame-arguments
2690 The value of this variable can be changed to control which argument
2691 values should be printed by the debugger when displaying a frame.
2696 Transfer files to and from a remote target, and delete remote files.
2703 Transfer files to and from a remote target, and delete remote files.
2705 * New remote packets
2712 Open, close, read, write, and delete files on the remote system.
2715 Attach to an existing process on the remote system, in extended-remote
2719 Run a new process on the remote system, in extended-remote mode.
2721 *** Changes in GDB 6.7
2723 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2724 bfd, libiberty and opcodes, as revealed by static analysis donated by
2725 Coverity, Inc. (http://scan.coverity.com).
2727 * When looking up multiply-defined global symbols, GDB will now prefer the
2728 symbol definition in the current shared library if it was built using the
2729 -Bsymbolic linker option.
2731 * When the Text User Interface (TUI) is not configured, GDB will now
2732 recognize the -tui command-line option and print a message that the TUI
2735 * The GDB remote stub, gdbserver, now has lower overhead for high
2736 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2738 * GDB for MIPS targets now autodetects whether a remote target provides
2739 32-bit or 64-bit register values.
2741 * Support for C++ member pointers has been improved.
2743 * GDB now understands XML target descriptions, which specify the
2744 target's overall architecture. GDB can read a description from
2745 a local file or over the remote serial protocol.
2747 * Vectors of single-byte data use a new integer type which is not
2748 automatically displayed as character or string data.
2750 * The /s format now works with the print command. It displays
2751 arrays of single-byte integers and pointers to single-byte integers
2754 * Target descriptions can now describe target-specific registers,
2755 for architectures which have implemented the support (currently
2756 only ARM, M68K, and MIPS).
2758 * GDB and the GDB remote stub, gdbserver, now support the XScale
2761 * The GDB remote stub, gdbserver, has been updated to support
2762 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2763 has been rewritten to use the standard GDB remote protocol.
2765 * GDB can now step into C++ functions which are called through thunks.
2767 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2769 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2770 layout. It also supports a TextSeg= and DataSeg= response when only
2771 segment base addresses (rather than offsets) are available.
2773 * The /i format now outputs any trailing branch delay slot instructions
2774 immediately following the last instruction within the count specified.
2776 * The GDB remote protocol "T" stop reply packet now supports a
2777 "library" response. Combined with the new "qXfer:libraries:read"
2778 packet, this response allows GDB to debug shared libraries on targets
2779 where the operating system manages the list of loaded libraries (e.g.
2780 Windows and SymbianOS).
2782 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2783 (DLLs) on Windows and Windows CE targets.
2785 * GDB now supports a faster verification that a .debug file matches its binary
2786 according to its build-id signature, if the signature is present.
2792 Enable or disable hardware flow control (RTS/CTS) on the serial port
2793 when debugging using remote targets.
2795 set mem inaccessible-by-default
2796 show mem inaccessible-by-default
2797 If the target supplies a memory map, for instance via the remote
2798 protocol's "qXfer:memory-map:read" packet, setting this variable
2799 prevents GDB from accessing memory outside the memory map. This
2800 is useful for targets with memory mapped registers or which react
2801 badly to accesses of unmapped address space.
2803 set breakpoint auto-hw
2804 show breakpoint auto-hw
2805 If the target supplies a memory map, for instance via the remote
2806 protocol's "qXfer:memory-map:read" packet, setting this variable
2807 lets GDB use hardware breakpoints automatically for memory regions
2808 where it can not use software breakpoints. This covers both the
2809 "break" command and internal breakpoints used for other commands
2810 including "next" and "finish".
2813 catch exception unhandled
2814 Stop the program execution when Ada exceptions are raised.
2817 Stop the program execution when an Ada assertion failed.
2821 Set an alternate system root for target files. This is a more
2822 general version of "set solib-absolute-prefix", which is now
2823 an alias to "set sysroot".
2826 Provide extended SPU facility status information. This set of
2827 commands is available only when debugging the Cell/B.E. SPU
2830 * New native configurations
2832 OpenBSD/sh sh*-*openbsd*
2835 unset tdesc filename
2837 Use the specified local file as an XML target description, and do
2838 not query the target for its built-in description.
2842 OpenBSD/sh sh*-*-openbsd*
2843 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2844 Toshiba Media Processor mep-elf
2846 * New remote packets
2849 Ignore the specified signals; pass them directly to the debugged program
2850 without stopping other threads or reporting them to GDB.
2852 qXfer:features:read:
2853 Read an XML target description from the target, which describes its
2858 Read or write contents of an spufs file on the target system. These
2859 packets are available only on the Cell/B.E. SPU architecture.
2861 qXfer:libraries:read:
2862 Report the loaded shared libraries. Combined with new "T" packet
2863 response, this packet allows GDB to debug shared libraries on
2864 targets where the operating system manages the list of loaded
2865 libraries (e.g. Windows and SymbianOS).
2869 Support for these obsolete configurations has been removed.
2877 i[34567]86-*-lynxos*
2878 i[34567]86-*-netware*
2879 i[34567]86-*-sco3.2v5*
2880 i[34567]86-*-sco3.2v4*
2882 i[34567]86-*-sysv4.2*
2885 i[34567]86-*-unixware2*
2886 i[34567]86-*-unixware*
2895 * Other removed features
2902 Various m68k-only ROM monitors.
2909 Various Renesas ROM monitors and debugging interfaces for SH and
2914 Support for a Macraigor serial interface to on-chip debugging.
2915 GDB does not directly support the newer parallel or USB
2920 A debug information format. The predecessor to DWARF 2 and
2921 DWARF 3, which are still supported.
2923 Support for the HP aCC compiler on HP-UX/PA-RISC
2925 SOM-encapsulated symbolic debugging information, automatic
2926 invocation of pxdb, and the aCC custom C++ ABI. This does not
2927 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2928 with aCC can still be debugged on an assembly level.
2930 MIPS ".pdr" sections
2932 A MIPS-specific format used to describe stack frame layout
2933 in debugging information.
2937 GDB could work with an older version of Guile to debug
2938 the interpreter and Scheme programs running in it.
2940 set mips stack-arg-size
2941 set mips saved-gpreg-size
2943 Use "set mips abi" to control parameter passing for MIPS.
2945 *** Changes in GDB 6.6
2950 Cell Broadband Engine SPU spu-elf
2952 * GDB can now be configured as a cross-debugger targeting native Windows
2953 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2954 running on a Windows system over TCP/IP to debug Windows programs.
2956 * The GDB remote stub, gdbserver, has been updated to support Windows and
2957 Cygwin debugging. Both single-threaded and multi-threaded programs are
2960 * The "set trust-readonly-sections" command works again. This command was
2961 broken in GDB 6.3, 6.4, and 6.5.
2963 * The "load" command now supports writing to flash memory, if the remote
2964 stub provides the required support.
2966 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2967 longer requires symbolic debug information (e.g. DWARF-2).
2972 unset substitute-path
2973 show substitute-path
2974 Manage a list of substitution rules that GDB uses to rewrite the name
2975 of the directories where the sources are located. This can be useful
2976 for instance when the sources were moved to a different location
2977 between compilation and debugging.
2981 Print each CLI command as it is executed. Each command is prefixed with
2982 a number of `+' symbols representing the nesting depth.
2983 The source command now has a `-v' option to enable the same feature.
2987 The ARM Demon monitor support (RDP protocol, "target rdp").
2989 Kernel Object Display, an embedded debugging feature which only worked with
2990 an obsolete version of Cisco IOS.
2992 The 'set download-write-size' and 'show download-write-size' commands.
2994 * New remote packets
2997 Tell a stub about GDB client features, and request remote target features.
2998 The first feature implemented is PacketSize, which allows the target to
2999 specify the size of packets it can handle - to minimize the number of
3000 packets required and improve performance when connected to a remote
3004 Fetch an OS auxilliary vector from the remote stub. This packet is a
3005 more efficient replacement for qPart:auxv:read.
3007 qXfer:memory-map:read:
3008 Fetch a memory map from the remote stub, including information about
3009 RAM, ROM, and flash memory devices.
3014 Erase and program a flash memory device.
3016 * Removed remote packets
3019 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3020 used it, and only gdbserver implemented it.
3022 *** Changes in GDB 6.5
3026 Renesas M32C/M16C m32c-elf
3028 Morpho Technologies ms1 ms1-elf
3032 init-if-undefined Initialize a convenience variable, but
3033 only if it doesn't already have a value.
3035 The following commands are presently only implemented for native GNU/Linux:
3037 checkpoint Save a snapshot of the program state.
3039 restart <n> Return the program state to a
3040 previously saved state.
3042 info checkpoints List currently saved checkpoints.
3044 delete-checkpoint <n> Delete a previously saved checkpoint.
3046 set|show detach-on-fork Tell gdb whether to detach from a newly
3047 forked process, or to keep debugging it.
3049 info forks List forks of the user program that
3050 are available to be debugged.
3052 fork <n> Switch to debugging one of several
3053 forks of the user program that are
3054 available to be debugged.
3056 delete-fork <n> Delete a fork from the list of forks
3057 that are available to be debugged (and
3058 kill the forked process).
3060 detach-fork <n> Delete a fork from the list of forks
3061 that are available to be debugged (and
3062 allow the process to continue).
3066 Morpho Technologies ms2 ms1-elf
3068 * Improved Windows host support
3070 GDB now builds as a cross debugger hosted on i686-mingw32, including
3071 native console support, and remote communications using either
3072 network sockets or serial ports.
3074 * Improved Modula-2 language support
3076 GDB can now print most types in the Modula-2 syntax. This includes:
3077 basic types, set types, record types, enumerated types, range types,
3078 pointer types and ARRAY types. Procedure var parameters are correctly
3079 printed and hexadecimal addresses and character constants are also
3080 written in the Modula-2 syntax. Best results can be obtained by using
3081 GNU Modula-2 together with the -gdwarf-2 command line option.
3085 The ARM rdi-share module.
3087 The Netware NLM debug server.
3089 *** Changes in GDB 6.4
3091 * New native configurations
3093 OpenBSD/arm arm*-*-openbsd*
3094 OpenBSD/mips64 mips64-*-openbsd*
3098 Morpho Technologies ms1 ms1-elf
3100 * New command line options
3102 --batch-silent As for --batch, but totally silent.
3103 --return-child-result The debugger will exist with the same value
3104 the child (debugged) program exited with.
3105 --eval-command COMMAND, -ex COMMAND
3106 Execute a single GDB CLI command. This may be
3107 specified multiple times and in conjunction
3108 with the --command (-x) option.
3110 * Deprecated commands removed
3112 The following commands, that were deprecated in 2000, have been
3116 set|show arm disassembly-flavor set|show arm disassembler
3117 othernames set arm disassembler
3118 set|show remotedebug set|show debug remote
3119 set|show archdebug set|show debug arch
3120 set|show eventdebug set|show debug event
3123 * New BSD user-level threads support
3125 It is now possible to debug programs using the user-level threads
3126 library on OpenBSD and FreeBSD. Currently supported (target)
3129 FreeBSD/amd64 x86_64-*-freebsd*
3130 FreeBSD/i386 i386-*-freebsd*
3131 OpenBSD/i386 i386-*-openbsd*
3133 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3134 are not yet supported.
3136 * New support for Matsushita MN10300 w/sim added
3137 (Work in progress). mn10300-elf.
3139 * REMOVED configurations and files
3141 VxWorks and the XDR protocol *-*-vxworks
3142 Motorola MCORE mcore-*-*
3143 National Semiconductor NS32000 ns32k-*-*
3145 * New "set print array-indexes" command
3147 After turning this setting "on", GDB prints the index of each element
3148 when displaying arrays. The default is "off" to preserve the previous
3151 * VAX floating point support
3153 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3155 * User-defined command support
3157 In addition to using $arg0..$arg9 for argument passing, it is now possible
3158 to use $argc to determine now many arguments have been passed. See the
3159 section on user-defined commands in the user manual for more information.
3161 *** Changes in GDB 6.3:
3163 * New command line option
3165 GDB now accepts -l followed by a number to set the timeout for remote
3168 * GDB works with GCC -feliminate-dwarf2-dups
3170 GDB now supports a more compact representation of DWARF-2 debug
3171 information using DW_FORM_ref_addr references. These are produced
3172 by GCC with the option -feliminate-dwarf2-dups and also by some
3173 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3174 to use -feliminate-dwarf2-dups.
3176 * Internationalization
3178 When supported by the host system, GDB will be built with
3179 internationalization (libintl). The task of marking up the sources is
3180 continued, we're looking forward to our first translation.
3184 Initial support for debugging programs compiled with the GNAT
3185 implementation of the Ada programming language has been integrated
3186 into GDB. In this release, support is limited to expression evaluation.
3188 * New native configurations
3190 GNU/Linux/m32r m32r-*-linux-gnu
3194 GDB's remote protocol now includes support for the 'p' packet. This
3195 packet is used to fetch individual registers from a remote inferior.
3197 * END-OF-LIFE registers[] compatibility module
3199 GDB's internal register infrastructure has been completely rewritten.
3200 The new infrastructure making possible the implementation of key new
3201 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3204 GDB 6.3 will be the last release to include the the registers[]
3205 compatibility module that allowed out-of-date configurations to
3206 continue to work. This change directly impacts the following
3216 powerpc bdm protocol
3218 Unless there is activity to revive these configurations, they will be
3219 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3221 * OBSOLETE configurations and files
3223 Configurations that have been declared obsolete in this release have
3224 been commented out. Unless there is activity to revive these
3225 configurations, the next release of GDB will have their sources
3226 permanently REMOVED.
3235 *** Changes in GDB 6.2.1:
3237 * MIPS `break main; run' gave an heuristic-fence-post warning
3239 When attempting to run even a simple program, a warning about
3240 heuristic-fence-post being hit would be reported. This problem has
3243 * MIPS IRIX 'long double' crashed GDB
3245 When examining a long double variable, GDB would get a segmentation
3246 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3247 IRIX long double values).
3251 A bug in the VAX stack code was causing problems with the "next"
3252 command. This problem has been fixed.
3254 *** Changes in GDB 6.2:
3256 * Fix for ``many threads''
3258 On GNU/Linux systems that use the NPTL threads library, a program
3259 rapidly creating and deleting threads would confuse GDB leading to the
3262 ptrace: No such process.
3263 thread_db_get_info: cannot get thread info: generic error
3265 This problem has been fixed.
3267 * "-async" and "-noasync" options removed.
3269 Support for the broken "-noasync" option has been removed (it caused
3272 * New ``start'' command.
3274 This command runs the program until the begining of the main procedure.
3276 * New BSD Kernel Data Access Library (libkvm) interface
3278 Using ``target kvm'' it is now possible to debug kernel core dumps and
3279 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3280 platforms. Currently supported (native-only) configurations are:
3282 FreeBSD/amd64 x86_64-*-freebsd*
3283 FreeBSD/i386 i?86-*-freebsd*
3284 NetBSD/i386 i?86-*-netbsd*
3285 NetBSD/m68k m68*-*-netbsd*
3286 NetBSD/sparc sparc-*-netbsd*
3287 OpenBSD/amd64 x86_64-*-openbsd*
3288 OpenBSD/i386 i?86-*-openbsd*
3289 OpenBSD/m68k m68*-openbsd*
3290 OpenBSD/sparc sparc-*-openbsd*
3292 * Signal trampoline code overhauled
3294 Many generic problems with GDB's signal handling code have been fixed.
3295 These include: backtraces through non-contiguous stacks; recognition
3296 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3297 call; backtrace through a signal trampoline; step into and out of
3298 signal handlers; and single-stepping in the signal trampoline.
3300 Please note that kernel bugs are a limiting factor here. These
3301 features have been shown to work on an s390 GNU/Linux system that
3302 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3304 * Cygwin support for DWARF 2 added.
3306 * New native configurations
3308 GNU/Linux/hppa hppa*-*-linux*
3309 OpenBSD/hppa hppa*-*-openbsd*
3310 OpenBSD/m68k m68*-*-openbsd*
3311 OpenBSD/m88k m88*-*-openbsd*
3312 OpenBSD/powerpc powerpc-*-openbsd*
3313 NetBSD/vax vax-*-netbsd*
3314 OpenBSD/vax vax-*-openbsd*
3316 * END-OF-LIFE frame compatibility module
3318 GDB's internal frame infrastructure has been completely rewritten.
3319 The new infrastructure making it possible to support key new features
3320 including DWARF 2 Call Frame Information. To aid in the task of
3321 migrating old configurations to this new infrastructure, a
3322 compatibility module, that allowed old configurations to continue to
3323 work, was also included.
3325 GDB 6.2 will be the last release to include this frame compatibility
3326 module. This change directly impacts the following configurations:
3336 Unless there is activity to revive these configurations, they will be
3337 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3339 * REMOVED configurations and files
3341 Sun 3, running SunOS 3 m68*-*-sunos3*
3342 Sun 3, running SunOS 4 m68*-*-sunos4*
3343 Sun 2, running SunOS 3 m68000-*-sunos3*
3344 Sun 2, running SunOS 4 m68000-*-sunos4*
3345 Motorola 680x0 running LynxOS m68*-*-lynxos*
3346 AT&T 3b1/Unix pc m68*-att-*
3347 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3348 decstation mips-dec-* mips-little-*
3349 riscos mips-*-riscos* mips-*-sysv*
3350 sonymips mips-sony-*
3351 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3353 *** Changes in GDB 6.1.1:
3355 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3357 The TUI (Text-mode User Interface) is now built as part of a default
3358 GDB configuration. It is enabled by either selecting the TUI with the
3359 command line option "-i=tui" or by running the separate "gdbtui"
3360 program. For more information on the TUI, see the manual "Debugging
3363 * Pending breakpoint support (also included in GDB 6.1)
3365 Support has been added to allow you to specify breakpoints in shared
3366 libraries that have not yet been loaded. If a breakpoint location
3367 cannot be found, and the "breakpoint pending" option is set to auto,
3368 GDB queries you if you wish to make the breakpoint pending on a future
3369 shared-library load. If and when GDB resolves the breakpoint symbol,
3370 the pending breakpoint is removed as one or more regular breakpoints
3373 Pending breakpoints are very useful for GCJ Java debugging.
3375 * Fixed ISO-C build problems
3377 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3378 non ISO-C code that stopped them being built using a more strict ISO-C
3379 compiler (e.g., IBM's C compiler).
3381 * Fixed build problem on IRIX 5
3383 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3384 wasn't able to compile compile on an IRIX 5 system.
3386 * Added execute permission to gdb/gdbserver/configure
3388 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3389 permission. This bug would cause configure to fail on a number of
3390 systems (Solaris, IRIX). Ref: server/519.
3392 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3394 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3395 has been updated to use constant array sizes.
3397 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3399 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3400 its generated DWARF Call Frame Info. This encoding was causing GDB to
3401 panic, that panic has been fixed. Ref: gdb/1628.
3403 * Fixed a problem when examining parameters in shared library code.
3405 When examining parameters in optimized shared library code generated
3406 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3407 not available''. GDB now correctly displays the variable's value.
3409 *** Changes in GDB 6.1:
3411 * Removed --with-mmalloc
3413 Support for the mmalloc memory manager has been removed, as it
3414 conflicted with the internal gdb byte cache.
3416 * Changes in AMD64 configurations
3418 The AMD64 target now includes the %cs and %ss registers. As a result
3419 the AMD64 remote protocol has changed; this affects the floating-point
3420 and SSE registers. If you rely on those registers for your debugging,
3421 you should upgrade gdbserver on the remote side.
3423 * Revised SPARC target
3425 The SPARC target has been completely revised, incorporating the
3426 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3427 support for LynxOS and SunOS 4 has been dropped. Calling functions
3428 from within GDB on operating systems with a non-executable stack
3429 (Solaris, OpenBSD) now works.
3433 GDB has a new C++ demangler which does a better job on the mangled
3434 names generated by current versions of g++. It also runs faster, so
3435 with this and other changes gdb should now start faster on large C++
3438 * DWARF 2 Location Expressions
3440 GDB support for location expressions has been extended to support function
3441 arguments and frame bases. Older versions of GDB could crash when they
3444 * C++ nested types and namespaces
3446 GDB's support for nested types and namespaces in C++ has been
3447 improved, especially if you use the DWARF 2 debugging format. (This
3448 is the default for recent versions of GCC on most platforms.)
3449 Specifically, if you have a class "Inner" defined within a class or
3450 namespace "Outer", then GDB realizes that the class's name is
3451 "Outer::Inner", not simply "Inner". This should greatly reduce the
3452 frequency of complaints about not finding RTTI symbols. In addition,
3453 if you are stopped at inside of a function defined within a namespace,
3454 GDB modifies its name lookup accordingly.
3456 * New native configurations
3458 NetBSD/amd64 x86_64-*-netbsd*
3459 OpenBSD/amd64 x86_64-*-openbsd*
3460 OpenBSD/alpha alpha*-*-openbsd*
3461 OpenBSD/sparc sparc-*-openbsd*
3462 OpenBSD/sparc64 sparc64-*-openbsd*
3464 * New debugging protocols
3466 M32R with SDI protocol m32r-*-elf*
3468 * "set prompt-escape-char" command deleted.
3470 The command "set prompt-escape-char" has been deleted. This command,
3471 and its very obscure effet on GDB's prompt, was never documented,
3472 tested, nor mentioned in the NEWS file.
3474 * OBSOLETE configurations and files
3476 Configurations that have been declared obsolete in this release have
3477 been commented out. Unless there is activity to revive these
3478 configurations, the next release of GDB will have their sources
3479 permanently REMOVED.
3481 Sun 3, running SunOS 3 m68*-*-sunos3*
3482 Sun 3, running SunOS 4 m68*-*-sunos4*
3483 Sun 2, running SunOS 3 m68000-*-sunos3*
3484 Sun 2, running SunOS 4 m68000-*-sunos4*
3485 Motorola 680x0 running LynxOS m68*-*-lynxos*
3486 AT&T 3b1/Unix pc m68*-att-*
3487 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3488 decstation mips-dec-* mips-little-*
3489 riscos mips-*-riscos* mips-*-sysv*
3490 sonymips mips-sony-*
3491 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3493 * REMOVED configurations and files
3495 SGI Irix-4.x mips-sgi-irix4 or iris4
3496 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3497 Z8000 simulator z8k-zilog-none or z8ksim
3498 Matsushita MN10200 w/simulator mn10200-*-*
3499 H8/500 simulator h8500-hitachi-hms or h8500hms
3500 HP/PA running BSD hppa*-*-bsd*
3501 HP/PA running OSF/1 hppa*-*-osf*
3502 HP/PA Pro target hppa*-*-pro*
3503 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3504 386BSD i[3456]86-*-bsd*
3505 Sequent family i[3456]86-sequent-sysv4*
3506 i[3456]86-sequent-sysv*
3507 i[3456]86-sequent-bsd*
3508 SPARC running LynxOS sparc-*-lynxos*
3509 SPARC running SunOS 4 sparc-*-sunos4*
3510 Tsqware Sparclet sparclet-*-*
3511 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3513 *** Changes in GDB 6.0:
3517 Support for debugging the Objective-C programming language has been
3518 integrated into GDB.
3520 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3522 DWARF 2's Call Frame Information makes available compiler generated
3523 information that more exactly describes the program's run-time stack.
3524 By using this information, GDB is able to provide more robust stack
3527 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3528 have been updated to use a new backtrace mechanism which includes
3529 DWARF 2 CFI support.
3533 GDB's remote protocol has been extended to include support for hosted
3534 file I/O (where the remote target uses GDB's file system). See GDB's
3535 remote protocol documentation for details.
3537 * All targets using the new architecture framework.
3539 All of GDB's targets have been updated to use the new internal
3540 architecture framework. The way is now open for future GDB releases
3541 to include cross-architecture native debugging support (i386 on amd64,
3544 * GNU/Linux's Thread Local Storage (TLS)
3546 GDB now includes support for for the GNU/Linux implementation of
3547 per-thread variables.
3549 * GNU/Linux's Native POSIX Thread Library (NPTL)
3551 GDB's thread code has been updated to work with either the new
3552 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3554 * Separate debug info.
3556 GDB, in conjunction with BINUTILS, now supports a mechanism for
3557 automatically loading debug information from a separate file. Instead
3558 of shipping full debug and non-debug versions of system libraries,
3559 system integrators can now instead ship just the stripped libraries
3560 and optional debug files.
3562 * DWARF 2 Location Expressions
3564 DWARF 2 Location Expressions allow the compiler to more completely
3565 describe the location of variables (even in optimized code) to the
3568 GDB now includes preliminary support for location expressions (support
3569 for DW_OP_piece is still missing).
3573 A number of long standing bugs that caused GDB to die while starting a
3574 Java application have been fixed. GDB's Java support is now
3575 considered "useable".
3577 * GNU/Linux support for fork, vfork, and exec.
3579 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3580 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3583 * GDB supports logging output to a file
3585 There are two new commands, "set logging" and "show logging", which can be
3586 used to capture GDB's output to a file.
3588 * The meaning of "detach" has changed for gdbserver
3590 The "detach" command will now resume the application, as documented. To
3591 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3594 * d10v, m68hc11 `regs' command deprecated
3596 The `info registers' command has been updated so that it displays the
3597 registers using a format identical to the old `regs' command.
3601 A new command, "maint set profile on/off", has been added. This command can
3602 be used to enable or disable profiling while running GDB, to profile a
3603 session or a set of commands. In addition there is a new configure switch,
3604 "--enable-profiling", which will cause GDB to be compiled with profiling
3605 data, for more informative profiling results.
3607 * Default MI syntax changed to "mi2".
3609 The default MI (machine interface) syntax, enabled by the command line
3610 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3611 "mi1", can be enabled by specifying the option "-i=mi1".
3613 Support for the original "mi0" syntax (included in GDB 5.0) has been
3616 Fix for gdb/192: removed extraneous space when displaying frame level.
3617 Fix for gdb/672: update changelist is now output in mi list format.
3618 Fix for gdb/702: a -var-assign that updates the value now shows up
3619 in a subsequent -var-update.
3621 * New native configurations.
3623 FreeBSD/amd64 x86_64-*-freebsd*
3625 * Multi-arched targets.
3627 HP/PA HPUX11 hppa*-*-hpux*
3628 Renesas M32R/D w/simulator m32r-*-elf*
3630 * OBSOLETE configurations and files
3632 Configurations that have been declared obsolete in this release have
3633 been commented out. Unless there is activity to revive these
3634 configurations, the next release of GDB will have their sources
3635 permanently REMOVED.
3637 Z8000 simulator z8k-zilog-none or z8ksim
3638 Matsushita MN10200 w/simulator mn10200-*-*
3639 H8/500 simulator h8500-hitachi-hms or h8500hms
3640 HP/PA running BSD hppa*-*-bsd*
3641 HP/PA running OSF/1 hppa*-*-osf*
3642 HP/PA Pro target hppa*-*-pro*
3643 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3644 Sequent family i[3456]86-sequent-sysv4*
3645 i[3456]86-sequent-sysv*
3646 i[3456]86-sequent-bsd*
3647 Tsqware Sparclet sparclet-*-*
3648 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3650 * REMOVED configurations and files
3653 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3654 IBM AIX PS/2 i[3456]86-*-aix
3655 i386 running Mach 3.0 i[3456]86-*-mach3*
3656 i386 running Mach i[3456]86-*-mach*
3657 i386 running OSF/1 i[3456]86-*osf1mk*
3658 HP/Apollo 68k Family m68*-apollo*-sysv*,
3660 m68*-hp-bsd*, m68*-hp-hpux*
3661 Argonaut Risc Chip (ARC) arc-*-*
3662 Mitsubishi D30V d30v-*-*
3663 Fujitsu FR30 fr30-*-elf*
3664 OS/9000 i[34]86-*-os9k
3665 I960 with MON960 i960-*-coff
3667 * MIPS $fp behavior changed
3669 The convenience variable $fp, for the MIPS, now consistently returns
3670 the address of the current frame's base. Previously, depending on the
3671 context, $fp could refer to either $sp or the current frame's base
3672 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3673 The GNU Source-Level Debugger''.
3675 *** Changes in GDB 5.3:
3677 * GNU/Linux shared library multi-threaded performance improved.
3679 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3680 `/proc', in preference to `ptrace' for memory reads. This may result
3681 in an improvement in the start-up time of multi-threaded, shared
3682 library applications when run under GDB. One GDB user writes: ``loads
3683 shared libs like mad''.
3685 * ``gdbserver'' now supports multi-threaded applications on some targets
3687 Support for debugging multi-threaded applications which use
3688 the GNU/Linux LinuxThreads package has been added for
3689 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3690 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3692 * GDB now supports C/C++ preprocessor macros.
3694 GDB now expands preprocessor macro invocations in C/C++ expressions,
3695 and provides various commands for showing macro definitions and how
3698 The new command `macro expand EXPRESSION' expands any macro
3699 invocations in expression, and shows the result.
3701 The new command `show macro MACRO-NAME' shows the definition of the
3702 macro named MACRO-NAME, and where it was defined.
3704 Most compilers don't include information about macros in the debugging
3705 information by default. In GCC 3.1, for example, you need to compile
3706 your program with the options `-gdwarf-2 -g3'. If the macro
3707 information is present in the executable, GDB will read it.
3709 * Multi-arched targets.
3711 DEC Alpha (partial) alpha*-*-*
3712 DEC VAX (partial) vax-*-*
3714 National Semiconductor NS32000 (partial) ns32k-*-*
3715 Motorola 68000 (partial) m68k-*-*
3716 Motorola MCORE mcore-*-*
3720 Fujitsu FRV architecture added by Red Hat frv*-*-*
3723 * New native configurations
3725 Alpha NetBSD alpha*-*-netbsd*
3726 SH NetBSD sh*-*-netbsdelf*
3727 MIPS NetBSD mips*-*-netbsd*
3728 UltraSPARC NetBSD sparc64-*-netbsd*
3730 * OBSOLETE configurations and files
3732 Configurations that have been declared obsolete in this release have
3733 been commented out. Unless there is activity to revive these
3734 configurations, the next release of GDB will have their sources
3735 permanently REMOVED.
3737 Mitsubishi D30V d30v-*-*
3738 OS/9000 i[34]86-*-os9k
3739 IBM AIX PS/2 i[3456]86-*-aix
3740 Fujitsu FR30 fr30-*-elf*
3741 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3742 Argonaut Risc Chip (ARC) arc-*-*
3743 i386 running Mach 3.0 i[3456]86-*-mach3*
3744 i386 running Mach i[3456]86-*-mach*
3745 i386 running OSF/1 i[3456]86-*osf1mk*
3746 HP/Apollo 68k Family m68*-apollo*-sysv*,
3748 m68*-hp-bsd*, m68*-hp-hpux*
3749 I960 with MON960 i960-*-coff
3751 * OBSOLETE languages
3753 CHILL, a Pascal like language used by telecommunications companies.
3755 * REMOVED configurations and files
3757 AMD 29k family via UDI a29k-amd-udi, udi29k
3758 A29K VxWorks a29k-*-vxworks
3759 AMD 29000 embedded, using EBMON a29k-none-none
3760 AMD 29000 embedded with COFF a29k-none-coff
3761 AMD 29000 embedded with a.out a29k-none-aout
3763 testsuite/gdb.hp/gdb.threads-hp/ directory
3765 * New command "set max-user-call-depth <nnn>"
3767 This command allows the user to limit the call depth of user-defined
3768 commands. The default is 1024.
3770 * Changes in FreeBSD/i386 native debugging.
3772 Support for the "generate-core-file" has been added.
3774 * New commands "dump", "append", and "restore".
3776 These commands allow data to be copied from target memory
3777 to a bfd-format or binary file (dump and append), and back
3778 from a file into memory (restore).
3780 * Improved "next/step" support on multi-processor Alpha Tru64.
3782 The previous single-step mechanism could cause unpredictable problems,
3783 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3784 of a software single-step mechanism prevents this.
3786 *** Changes in GDB 5.2.1:
3794 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3795 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3796 Fix, by Joel Brobecker imported from mainline.
3798 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3799 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3800 Fix, by Fred Fish, imported from mainline.
3802 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3803 Surprisingly enough, it works now.
3804 By Michal Ludvig, imported from mainline.
3806 i386 hardware watchpoint support:
3807 avoid misses on second run for some targets.
3808 By Pierre Muller, imported from mainline.
3810 *** Changes in GDB 5.2:
3812 * New command "set trust-readonly-sections on[off]".
3814 This command is a hint that tells gdb that read-only sections
3815 really are read-only (ie. that their contents will not change).
3816 In this mode, gdb will go to the object file rather than the
3817 target to read memory from read-only sections (such as ".text").
3818 This can be a significant performance improvement on some
3819 (notably embedded) targets.
3821 * New command "generate-core-file" (or "gcore").
3823 This new gdb command allows the user to drop a core file of the child
3824 process state at any time. So far it's been implemented only for
3825 GNU/Linux and Solaris, but should be relatively easily ported to other
3826 hosts. Argument is core file name (defaults to core.<pid>).
3828 * New command line option
3830 GDB now accepts --pid or -p followed by a process id.
3832 * Change in command line behavior -- corefiles vs. process ids.
3834 There is a subtle behavior in the way in which GDB handles
3835 command line arguments. The first non-flag argument is always
3836 a program to debug, but the second non-flag argument may either
3837 be a corefile or a process id. Previously, GDB would attempt to
3838 open the second argument as a corefile, and if that failed, would
3839 issue a superfluous error message and then attempt to attach it as
3840 a process. Now, if the second argument begins with a non-digit,
3841 it will be treated as a corefile. If it begins with a digit,
3842 GDB will attempt to attach it as a process, and if no such process
3843 is found, will then attempt to open it as a corefile.
3845 * Changes in ARM configurations.
3847 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3848 configuration is fully multi-arch.
3850 * New native configurations
3852 ARM NetBSD arm*-*-netbsd*
3853 x86 OpenBSD i[3456]86-*-openbsd*
3854 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3855 Sparc64 running FreeBSD sparc64-*-freebsd*
3859 Sanyo XStormy16 xstormy16-elf
3861 * OBSOLETE configurations and files
3863 Configurations that have been declared obsolete in this release have
3864 been commented out. Unless there is activity to revive these
3865 configurations, the next release of GDB will have their sources
3866 permanently REMOVED.
3868 AMD 29k family via UDI a29k-amd-udi, udi29k
3869 A29K VxWorks a29k-*-vxworks
3870 AMD 29000 embedded, using EBMON a29k-none-none
3871 AMD 29000 embedded with COFF a29k-none-coff
3872 AMD 29000 embedded with a.out a29k-none-aout
3874 testsuite/gdb.hp/gdb.threads-hp/ directory
3876 * REMOVED configurations and files
3878 TI TMS320C80 tic80-*-*
3880 PowerPC Solaris powerpcle-*-solaris*
3881 PowerPC Windows NT powerpcle-*-cygwin32
3882 PowerPC Netware powerpc-*-netware*
3883 Harris/CXUX m88k m88*-harris-cxux*
3884 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3885 ns32k-utek-sysv* ns32k-utek-*
3886 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3887 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3888 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3889 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3890 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3892 * Changes to command line processing
3894 The new `--args' feature can be used to specify command-line arguments
3895 for the inferior from gdb's command line.
3897 * Changes to key bindings
3899 There is a new `operate-and-get-next' function bound to `C-o'.
3901 *** Changes in GDB 5.1.1
3903 Fix compile problem on DJGPP.
3905 Fix a problem with floating-point registers on the i386 being
3908 Fix to stop GDB crashing on .debug_str debug info.
3910 Numerous documentation fixes.
3912 Numerous testsuite fixes.
3914 *** Changes in GDB 5.1:
3916 * New native configurations
3918 Alpha FreeBSD alpha*-*-freebsd*
3919 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3920 MIPS GNU/Linux mips*-*-linux*
3921 MIPS SGI Irix 6.x mips*-sgi-irix6*
3922 ia64 AIX ia64-*-aix*
3923 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3927 Motorola 68HC11 and 68HC12 m68hc11-elf
3929 UltraSparc running GNU/Linux sparc64-*-linux*
3931 * OBSOLETE configurations and files
3933 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3934 Harris/CXUX m88k m88*-harris-cxux*
3935 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3936 ns32k-utek-sysv* ns32k-utek-*
3937 TI TMS320C80 tic80-*-*
3939 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3940 PowerPC Solaris powerpcle-*-solaris*
3941 PowerPC Windows NT powerpcle-*-cygwin32
3942 PowerPC Netware powerpc-*-netware*
3943 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3944 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3945 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3946 Apple Macintosh (MPW) host N/A
3948 stuff.c (Program to stuff files into a specially prepared space in kdb)
3949 kdb-start.c (Main loop for the standalone kernel debugger)
3951 Configurations that have been declared obsolete in this release have
3952 been commented out. Unless there is activity to revive these
3953 configurations, the next release of GDB will have their sources
3954 permanently REMOVED.
3956 * REMOVED configurations and files
3958 Altos 3068 m68*-altos-*
3959 Convex c1-*-*, c2-*-*
3961 ARM RISCix arm-*-* (as host)
3965 * GDB has been converted to ISO C.
3967 GDB's source code has been converted to ISO C. In particular, the
3968 sources are fully protoized, and rely on standard headers being
3973 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3975 * The MI enabled by default.
3977 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3978 revised and enabled by default. Packages which use GDB as a debugging
3979 engine behind a UI or another front end are encouraged to switch to
3980 using the GDB/MI interface, instead of the old annotations interface
3981 which is now deprecated.
3983 * Support for debugging Pascal programs.
3985 GDB now includes support for debugging Pascal programs. The following
3986 main features are supported:
3988 - Pascal-specific data types such as sets;
3990 - automatic recognition of Pascal sources based on file-name
3993 - Pascal-style display of data types, variables, and functions;
3995 - a Pascal expression parser.
3997 However, some important features are not yet supported.
3999 - Pascal string operations are not supported at all;
4001 - there are some problems with boolean types;
4003 - Pascal type hexadecimal constants are not supported
4004 because they conflict with the internal variables format;
4006 - support for Pascal objects and classes is not full yet;
4008 - unlike Pascal, GDB is case-sensitive for symbol names.
4010 * Changes in completion.
4012 Commands such as `shell', `run' and `set args', which pass arguments
4013 to inferior programs, now complete on file names, similar to what
4014 users expect at the shell prompt.
4016 Commands which accept locations, such as `disassemble', `print',
4017 `breakpoint', `until', etc. now complete on filenames as well as
4018 program symbols. Thus, if you type "break foob TAB", and the source
4019 files linked into the programs include `foobar.c', that file name will
4020 be one of the candidates for completion. However, file names are not
4021 considered for completion after you typed a colon that delimits a file
4022 name from a name of a function in that file, as in "break foo.c:bar".
4024 `set demangle-style' completes on available demangling styles.
4026 * New platform-independent commands:
4028 It is now possible to define a post-hook for a command as well as a
4029 hook that runs before the command. For more details, see the
4030 documentation of `hookpost' in the GDB manual.
4032 * Changes in GNU/Linux native debugging.
4034 Support for debugging multi-threaded programs has been completely
4035 revised for all platforms except m68k and sparc. You can now debug as
4036 many threads as your system allows you to have.
4038 Attach/detach is supported for multi-threaded programs.
4040 Support for SSE registers was added for x86. This doesn't work for
4041 multi-threaded programs though.
4043 * Changes in MIPS configurations.
4045 Multi-arch support is enabled for all MIPS configurations.
4047 GDB can now be built as native debugger on SGI Irix 6.x systems for
4048 debugging n32 executables. (Debugging 64-bit executables is not yet
4051 * Unified support for hardware watchpoints in all x86 configurations.
4053 Most (if not all) native x86 configurations support hardware-assisted
4054 breakpoints and watchpoints in a unified manner. This support
4055 implements debug register sharing between watchpoints, which allows to
4056 put a virtually infinite number of watchpoints on the same address,
4057 and also supports watching regions up to 16 bytes with several debug
4060 The new maintenance command `maintenance show-debug-regs' toggles
4061 debugging print-outs in functions that insert, remove, and test
4062 watchpoints and hardware breakpoints.
4064 * Changes in the DJGPP native configuration.
4066 New command ``info dos sysinfo'' displays assorted information about
4067 the CPU, OS, memory, and DPMI server.
4069 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4070 display information about segment descriptors stored in GDT, LDT, and
4073 New commands ``info dos pde'' and ``info dos pte'' display entries
4074 from Page Directory and Page Tables (for now works with CWSDPMI only).
4075 New command ``info dos address-pte'' displays the Page Table entry for
4076 a given linear address.
4078 GDB can now pass command lines longer than 126 characters to the
4079 program being debugged (requires an update to the libdbg.a library
4080 which is part of the DJGPP development kit).
4082 DWARF2 debug info is now supported.
4084 It is now possible to `step' and `next' through calls to `longjmp'.
4086 * Changes in documentation.
4088 All GDB documentation was converted to GFDL, the GNU Free
4089 Documentation License.
4091 Tracepoints-related commands are now fully documented in the GDB
4094 TUI, the Text-mode User Interface, is now documented in the manual.
4096 Tracepoints-related commands are now fully documented in the GDB
4099 The "GDB Internals" manual now has an index. It also includes
4100 documentation of `ui_out' functions, GDB coding standards, x86
4101 hardware watchpoints, and memory region attributes.
4103 * GDB's version number moved to ``version.in''
4105 The Makefile variable VERSION has been replaced by the file
4106 ``version.in''. People creating GDB distributions should update the
4107 contents of this file.
4111 GUD support is now a standard part of the EMACS distribution.
4113 *** Changes in GDB 5.0:
4115 * Improved support for debugging FP programs on x86 targets
4117 Unified and much-improved support for debugging floating-point
4118 programs on all x86 targets. In particular, ``info float'' now
4119 displays the FP registers in the same format on all x86 targets, with
4120 greater level of detail.
4122 * Improvements and bugfixes in hardware-assisted watchpoints
4124 It is now possible to watch array elements, struct members, and
4125 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4126 on x86 targets no longer erroneously trigger when the address is
4129 * Improvements in the native DJGPP version of GDB
4131 The distribution now includes all the scripts and auxiliary files
4132 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4133 machines ``out of the box''.
4135 The DJGPP version can now debug programs that use signals. It is
4136 possible to catch signals that happened in the debuggee, deliver
4137 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4138 would kill the program being debugged.) Programs that hook hardware
4139 interrupts (keyboard, timer, etc.) can also be debugged.
4141 It is now possible to debug DJGPP programs that redirect their
4142 standard handles or switch them to raw (as opposed to cooked) mode, or
4143 even close them. The command ``run < foo > bar'' works as expected,
4144 and ``info terminal'' reports useful information about the debuggee's
4145 terminal, including raw/cooked mode, redirection, etc.
4147 The DJGPP version now uses termios functions for console I/O, which
4148 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4151 DOS-style file names with drive letters are now fully supported by
4154 It is now possible to debug DJGPP programs that switch their working
4155 directory. It is also possible to rerun the debuggee any number of
4156 times without restarting GDB; thus, you can use the same setup,
4157 breakpoints, etc. for many debugging sessions.
4159 * New native configurations
4161 ARM GNU/Linux arm*-*-linux*
4162 PowerPC GNU/Linux powerpc-*-linux*
4166 Motorola MCore mcore-*-*
4167 x86 VxWorks i[3456]86-*-vxworks*
4168 PowerPC VxWorks powerpc-*-vxworks*
4169 TI TMS320C80 tic80-*-*
4171 * OBSOLETE configurations
4173 Altos 3068 m68*-altos-*
4174 Convex c1-*-*, c2-*-*
4176 ARM RISCix arm-*-* (as host)
4179 Configurations that have been declared obsolete will be commented out,
4180 but the code will be left in place. If there is no activity to revive
4181 these configurations before the next release of GDB, the sources will
4182 be permanently REMOVED.
4184 * Gould support removed
4186 Support for the Gould PowerNode and NP1 has been removed.
4188 * New features for SVR4
4190 On SVR4 native platforms (such as Solaris), if you attach to a process
4191 without first loading a symbol file, GDB will now attempt to locate and
4192 load symbols from the running process's executable file.
4194 * Many C++ enhancements
4196 C++ support has been greatly improved. Overload resolution now works properly
4197 in almost all cases. RTTI support is on the way.
4199 * Remote targets can connect to a sub-program
4201 A popen(3) style serial-device has been added. This device starts a
4202 sub-process (such as a stand-alone simulator) and then communicates
4203 with that. The sub-program to run is specified using the syntax
4204 ``|<program> <args>'' vis:
4206 (gdb) set remotedebug 1
4207 (gdb) target extended-remote |mn10300-elf-sim program-args
4209 * MIPS 64 remote protocol
4211 A long standing bug in the mips64 remote protocol where by GDB
4212 expected certain 32 bit registers (ex SR) to be transfered as 32
4213 instead of 64 bits has been fixed.
4215 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4216 added to provide backward compatibility with older versions of GDB.
4218 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4220 The command ``set remotebinarydownload'' command has been replaced by
4221 ``set remote X-packet''. Other commands in ``set remote'' family
4222 include ``set remote P-packet''.
4224 * Breakpoint commands accept ranges.
4226 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4227 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4228 ``tracepoint passcount'' also accepts a range of tracepoints.
4230 * ``apropos'' command added.
4232 The ``apropos'' command searches through command names and
4233 documentation strings, printing out matches, making it much easier to
4234 try to find a command that does what you are looking for.
4238 A new machine oriented interface (MI) has been added to GDB. This
4239 interface is designed for debug environments running GDB as a separate
4240 process. This is part of the long term libGDB project. See the
4241 "GDB/MI" chapter of the GDB manual for further information. It can be
4242 enabled by configuring with:
4244 .../configure --enable-gdbmi
4246 *** Changes in GDB-4.18:
4248 * New native configurations
4250 HP-UX 10.20 hppa*-*-hpux10.20
4251 HP-UX 11.x hppa*-*-hpux11.0*
4252 M68K GNU/Linux m68*-*-linux*
4256 Fujitsu FR30 fr30-*-elf*
4257 Intel StrongARM strongarm-*-*
4258 Mitsubishi D30V d30v-*-*
4260 * OBSOLETE configurations
4262 Gould PowerNode, NP1 np1-*-*, pn-*-*
4264 Configurations that have been declared obsolete will be commented out,
4265 but the code will be left in place. If there is no activity to revive
4266 these configurations before the next release of GDB, the sources will
4267 be permanently REMOVED.
4271 As a compatibility experiment, GDB's source files buildsym.h and
4272 buildsym.c have been converted to pure standard C, no longer
4273 containing any K&R compatibility code. We believe that all systems in
4274 use today either come with a standard C compiler, or have a GCC port
4275 available. If this is not true, please report the affected
4276 configuration to bug-gdb@gnu.org immediately. See the README file for
4277 information about getting a standard C compiler if you don't have one
4282 GDB now uses readline 2.2.
4284 * set extension-language
4286 You can now control the mapping between filename extensions and source
4287 languages by using the `set extension-language' command. For instance,
4288 you can ask GDB to treat .c files as C++ by saying
4289 set extension-language .c c++
4290 The command `info extensions' lists all of the recognized extensions
4291 and their associated languages.
4293 * Setting processor type for PowerPC and RS/6000
4295 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4296 you can use the `set processor' command to specify what variant of the
4297 PowerPC family you are debugging. The command
4301 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4302 following PowerPC and RS6000 variants:
4304 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4305 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4307 403GC IBM PowerPC 403GC
4308 505 Motorola PowerPC 505
4309 860 Motorola PowerPC 860 or 850
4310 601 Motorola PowerPC 601
4311 602 Motorola PowerPC 602
4312 603 Motorola/IBM PowerPC 603 or 603e
4313 604 Motorola PowerPC 604 or 604e
4314 750 Motorola/IBM PowerPC 750 or 750
4316 At the moment, this command just tells GDB what to name the
4317 special-purpose processor registers. Since almost all the affected
4318 registers are inaccessible to user-level programs, this command is
4319 only useful for remote debugging in its present form.
4323 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4324 more extensive support for HP-UX. Added features include shared
4325 library support, kernel threads and hardware watchpoints for 11.00,
4326 support for HP's ANSI C and C++ compilers, and a compatibility mode
4327 for xdb and dbx commands.
4331 HP's donation includes the new concept of catchpoints, which is a
4332 generalization of the old catch command. On HP-UX, it is now possible
4333 to catch exec, fork, and vfork, as well as library loading.
4335 This means that the existing catch command has changed; its first
4336 argument now specifies the type of catch to be set up. See the
4337 output of "help catch" for a list of catchpoint types.
4339 * Debugging across forks
4341 On HP-UX, you can choose which process to debug when a fork() happens
4346 HP has donated a curses-based terminal user interface (TUI). To get
4347 it, build with --enable-tui. Although this can be enabled for any
4348 configuration, at present it only works for native HP debugging.
4350 * GDB remote protocol additions
4352 A new protocol packet 'X' that writes binary data is now available.
4353 Default behavior is to try 'X', then drop back to 'M' if the stub
4354 fails to respond. The settable variable `remotebinarydownload'
4355 allows explicit control over the use of 'X'.
4357 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4358 full 64-bit address. The command
4360 set remoteaddresssize 32
4362 can be used to revert to the old behaviour. For existing remote stubs
4363 the change should not be noticed, as the additional address information
4366 In order to assist in debugging stubs, you may use the maintenance
4367 command `packet' to send any text string to the stub. For instance,
4369 maint packet heythere
4371 sends the packet "$heythere#<checksum>". Note that it is very easy to
4372 disrupt a debugging session by sending the wrong packet at the wrong
4375 The compare-sections command allows you to compare section data on the
4376 target to what is in the executable file without uploading or
4377 downloading, by comparing CRC checksums.
4379 * Tracing can collect general expressions
4381 You may now collect general expressions at tracepoints. This requires
4382 further additions to the target-side stub; see tracepoint.c and
4383 doc/agentexpr.texi for further details.
4385 * mask-address variable for Mips
4387 For Mips targets, you may control the zeroing of the upper 32 bits of
4388 a 64-bit address by entering `set mask-address on'. This is mainly
4389 of interest to users of embedded R4xxx and R5xxx processors.
4391 * Higher serial baud rates
4393 GDB's serial code now allows you to specify baud rates 57600, 115200,
4394 230400, and 460800 baud. (Note that your host system may not be able
4395 to achieve all of these rates.)
4399 The i960 configuration now includes an initial implementation of a
4400 builtin simulator, contributed by Jim Wilson.
4403 *** Changes in GDB-4.17:
4405 * New native configurations
4407 Alpha GNU/Linux alpha*-*-linux*
4408 Unixware 2.x i[3456]86-unixware2*
4409 Irix 6.x mips*-sgi-irix6*
4410 PowerPC GNU/Linux powerpc-*-linux*
4411 PowerPC Solaris powerpcle-*-solaris*
4412 Sparc GNU/Linux sparc-*-linux*
4413 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4417 Argonaut Risc Chip (ARC) arc-*-*
4418 Hitachi H8/300S h8300*-*-*
4419 Matsushita MN10200 w/simulator mn10200-*-*
4420 Matsushita MN10300 w/simulator mn10300-*-*
4421 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4422 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4423 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4424 Mitsubishi D10V w/simulator d10v-*-*
4425 Mitsubishi M32R/D w/simulator m32r-*-elf*
4426 Tsqware Sparclet sparclet-*-*
4427 NEC V850 w/simulator v850-*-*
4429 * New debugging protocols
4431 ARM with RDI protocol arm*-*-*
4432 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4433 DDB and LSI variants of PMON protocol mips*-*-*
4434 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4435 PowerPC with SDS protocol powerpc{,le}-*-eabi
4436 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4440 All configurations can now understand and use the DWARF 2 debugging
4441 format. The choice is automatic, if the symbol file contains DWARF 2
4446 GDB now includes basic Java language support. This support is
4447 only useful with Java compilers that produce native machine code.
4449 * solib-absolute-prefix and solib-search-path
4451 For SunOS and SVR4 shared libraries, you may now set the prefix for
4452 loading absolute shared library symbol files, and the search path for
4453 locating non-absolute shared library symbol files.
4455 * Live range splitting
4457 GDB can now effectively debug code for which GCC has performed live
4458 range splitting as part of its optimization. See gdb/doc/LRS for
4459 more details on the expected format of the stabs information.
4463 GDB's support for the GNU Hurd, including thread debugging, has been
4464 updated to work with current versions of the Hurd.
4468 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4469 instruction set. ARM GDB automatically detects when Thumb
4470 instructions are in use, and adjusts disassembly and backtracing
4475 GDB's MIPS target configurations now handle the MIP16 16-bit
4480 GDB now includes support for overlays; if an executable has been
4481 linked such that multiple sections are based at the same address, GDB
4482 will decide which section to use for symbolic info. You can choose to
4483 control the decision manually, using overlay commands, or implement
4484 additional target-side support and use "overlay load-target" to bring
4485 in the overlay mapping. Do "help overlay" for more detail.
4489 The command "info symbol <address>" displays information about
4490 the symbol at the specified address.
4494 The standard remote protocol now includes an extension that allows
4495 asynchronous collection and display of trace data. This requires
4496 extensive support in the target-side debugging stub. Tracing mode
4497 includes a new interaction mode in GDB and new commands: see the
4498 file tracepoint.c for more details.
4502 Configurations for embedded MIPS now include a simulator contributed
4503 by Cygnus Solutions. The simulator supports the instruction sets
4504 of most MIPS variants.
4508 Sparc configurations may now include the ERC32 simulator contributed
4509 by the European Space Agency. The simulator is not built into
4510 Sparc targets by default; configure with --enable-sim to include it.
4514 For target configurations that may include multiple variants of a
4515 basic architecture (such as MIPS and SH), you may now set the
4516 architecture explicitly. "set arch" sets, "info arch" lists
4517 the possible architectures.
4519 *** Changes in GDB-4.16:
4521 * New native configurations
4523 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4524 M68K NetBSD m68k-*-netbsd*
4525 PowerPC AIX 4.x powerpc-*-aix*
4526 PowerPC MacOS powerpc-*-macos*
4527 PowerPC Windows NT powerpcle-*-cygwin32
4528 RS/6000 AIX 4.x rs6000-*-aix4*
4532 ARM with RDP protocol arm-*-*
4533 I960 with MON960 i960-*-coff
4534 MIPS VxWorks mips*-*-vxworks*
4535 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4536 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4538 Matra Sparclet sparclet-*-*
4542 The powerpc-eabi configuration now includes the PSIM simulator,
4543 contributed by Andrew Cagney, with assistance from Mike Meissner.
4544 PSIM is a very elaborate model of the PowerPC, including not only
4545 basic instruction set execution, but also details of execution unit
4546 performance and I/O hardware. See sim/ppc/README for more details.
4550 GDB now works with Solaris 2.5.
4552 * Windows 95/NT native
4554 GDB will now work as a native debugger on Windows 95 and Windows NT.
4555 To build it from source, you must use the "gnu-win32" environment,
4556 which uses a DLL to emulate enough of Unix to run the GNU tools.
4557 Further information, binaries, and sources are available at
4558 ftp.cygnus.com, under pub/gnu-win32.
4560 * dont-repeat command
4562 If a user-defined command includes the command `dont-repeat', then the
4563 command will not be repeated if the user just types return. This is
4564 useful if the command is time-consuming to run, so that accidental
4565 extra keystrokes don't run the same command many times.
4567 * Send break instead of ^C
4569 The standard remote protocol now includes an option to send a break
4570 rather than a ^C to the target in order to interrupt it. By default,
4571 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4573 * Remote protocol timeout
4575 The standard remote protocol includes a new variable `remotetimeout'
4576 that allows you to set the number of seconds before GDB gives up trying
4577 to read from the target. The default value is 2.
4579 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4581 By default GDB will automatically keep track of objects as they are
4582 loaded and unloaded by the dynamic linker. By using the command `set
4583 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4584 when shared library events occur, thus allowing you to set breakpoints
4585 in shared libraries which are explicitly loaded by the inferior.
4587 Note this feature does not work on hpux8. On hpux9 you must link
4588 /usr/lib/end.o into your program. This feature should work
4589 automatically on hpux10.
4591 * Irix 5.x hardware watchpoint support
4593 Irix 5 configurations now support the use of hardware watchpoints.
4595 * Mips protocol "SYN garbage limit"
4597 When debugging a Mips target using the `target mips' protocol, you
4598 may set the number of characters that GDB will ignore by setting
4599 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4600 every character. The default value is 1050.
4602 * Recording and replaying remote debug sessions
4604 If you set `remotelogfile' to the name of a file, gdb will write to it
4605 a recording of a remote debug session. This recording may then be
4606 replayed back to gdb using "gdbreplay". See gdbserver/README for
4607 details. This is useful when you have a problem with GDB while doing
4608 remote debugging; you can make a recording of the session and send it
4609 to someone else, who can then recreate the problem.
4611 * Speedups for remote debugging
4613 GDB includes speedups for downloading and stepping MIPS systems using
4614 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4615 and more efficient S-record downloading.
4617 * Memory use reductions and statistics collection
4619 GDB now uses less memory and reports statistics about memory usage.
4620 Try the `maint print statistics' command, for example.
4622 *** Changes in GDB-4.15:
4624 * Psymtabs for XCOFF
4626 The symbol reader for AIX GDB now uses partial symbol tables. This
4627 can greatly improve startup time, especially for large executables.
4629 * Remote targets use caching
4631 Remote targets now use a data cache to speed up communication with the
4632 remote side. The data cache could lead to incorrect results because
4633 it doesn't know about volatile variables, thus making it impossible to
4634 debug targets which use memory mapped I/O devices. `set remotecache
4635 off' turns the the data cache off.
4637 * Remote targets may have threads
4639 The standard remote protocol now includes support for multiple threads
4640 in the target system, using new protocol commands 'H' and 'T'. See
4641 gdb/remote.c for details.
4645 If GDB is configured with `--enable-netrom', then it will include
4646 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4647 acts as though it is a bank of ROM on the target board, but you can
4648 write into it over the network. GDB's support consists only of
4649 support for fast loading into the emulated ROM; to debug, you must use
4650 another protocol, such as standard remote protocol. The usual
4651 sequence is something like
4653 target nrom <netrom-hostname>
4655 target remote <netrom-hostname>:1235
4659 GDB now includes support for the Apple Macintosh, as a host only. It
4660 may be run as either an MPW tool or as a standalone application, and
4661 it can debug through the serial port. All the usual GDB commands are
4662 available, but to the target command, you must supply "serial" as the
4663 device type instead of "/dev/ttyXX". See mpw-README in the main
4664 directory for more information on how to build. The MPW configuration
4665 scripts */mpw-config.in support only a few targets, and only the
4666 mips-idt-ecoff target has been tested.
4670 GDB configuration now uses autoconf. This is not user-visible,
4671 but does simplify configuration and building.
4675 GDB now supports hpux10.
4677 *** Changes in GDB-4.14:
4679 * New native configurations
4681 x86 FreeBSD i[345]86-*-freebsd
4682 x86 NetBSD i[345]86-*-netbsd
4683 NS32k NetBSD ns32k-*-netbsd
4684 Sparc NetBSD sparc-*-netbsd
4688 A29K VxWorks a29k-*-vxworks
4689 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4690 CPU32 EST-300 emulator m68*-*-est*
4691 PowerPC ELF powerpc-*-elf
4694 * Alpha OSF/1 support for procfs
4696 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4697 possible to attach to running processes. As the mounting of the /proc
4698 filesystem is optional on the Alpha, GDB automatically determines
4699 the availability of /proc during startup. This can lead to problems
4700 if /proc is unmounted after GDB has been started.
4702 * Arguments to user-defined commands
4704 User commands may accept up to 10 arguments separated by whitespace.
4705 Arguments are accessed within the user command via $arg0..$arg9. A
4708 print $arg0 + $arg1 + $arg2
4710 To execute the command use:
4713 Defines the command "adder" which prints the sum of its three arguments.
4714 Note the arguments are text substitutions, so they may reference variables,
4715 use complex expressions, or even perform inferior function calls.
4717 * New `if' and `while' commands
4719 This makes it possible to write more sophisticated user-defined
4720 commands. Both commands take a single argument, which is the
4721 expression to evaluate, and must be followed by the commands to
4722 execute, one per line, if the expression is nonzero, the list being
4723 terminated by the word `end'. The `if' command list may include an
4724 `else' word, which causes the following commands to be executed only
4725 if the expression is zero.
4727 * Fortran source language mode
4729 GDB now includes partial support for Fortran 77. It will recognize
4730 Fortran programs and can evaluate a subset of Fortran expressions, but
4731 variables and functions may not be handled correctly. GDB will work
4732 with G77, but does not yet know much about symbols emitted by other
4735 * Better HPUX support
4737 Most debugging facilities now work on dynamic executables for HPPAs
4738 running hpux9 or later. You can attach to running dynamically linked
4739 processes, but by default the dynamic libraries will be read-only, so
4740 for instance you won't be able to put breakpoints in them. To change
4741 that behavior do the following before running the program:
4747 This will cause the libraries to be mapped private and read-write.
4748 To revert to the normal behavior, do this:
4754 You cannot set breakpoints or examine data in the library until after
4755 the library is loaded if the function/data symbols do not have
4758 GDB can now also read debug symbols produced by the HP C compiler on
4759 HPPAs (sorry, no C++, Fortran or 68k support).
4761 * Target byte order now dynamically selectable
4763 You can choose which byte order to use with a target system, via the
4764 commands "set endian big" and "set endian little", and you can see the
4765 current setting by using "show endian". You can also give the command
4766 "set endian auto", in which case GDB will use the byte order
4767 associated with the executable. Currently, only embedded MIPS
4768 configurations support dynamic selection of target byte order.
4770 * New DOS host serial code
4772 This version uses DPMI interrupts to handle buffered I/O, so you
4773 no longer need to run asynctsr when debugging boards connected to
4776 *** Changes in GDB-4.13:
4778 * New "complete" command
4780 This lists all the possible completions for the rest of the line, if it
4781 were to be given as a command itself. This is intended for use by emacs.
4783 * Trailing space optional in prompt
4785 "set prompt" no longer adds a space for you after the prompt you set. This
4786 allows you to set a prompt which ends in a space or one that does not.
4788 * Breakpoint hit counts
4790 "info break" now displays a count of the number of times the breakpoint
4791 has been hit. This is especially useful in conjunction with "ignore"; you
4792 can ignore a large number of breakpoint hits, look at the breakpoint info
4793 to see how many times the breakpoint was hit, then run again, ignoring one
4794 less than that number, and this will get you quickly to the last hit of
4797 * Ability to stop printing at NULL character
4799 "set print null-stop" will cause GDB to stop printing the characters of
4800 an array when the first NULL is encountered. This is useful when large
4801 arrays actually contain only short strings.
4803 * Shared library breakpoints
4805 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4806 breakpoints in shared libraries before the executable is run.
4808 * Hardware watchpoints
4810 There is a new hardware breakpoint for the watch command for sparclite
4811 targets. See gdb/sparclite/hw_breakpoint.note.
4813 Hardware watchpoints are also now supported under GNU/Linux.
4817 Annotations have been added. These are for use with graphical interfaces,
4818 and are still experimental. Currently only gdba.el uses these.
4820 * Improved Irix 5 support
4822 GDB now works properly with Irix 5.2.
4824 * Improved HPPA support
4826 GDB now works properly with the latest GCC and GAS.
4828 * New native configurations
4830 Sequent PTX4 i[34]86-sequent-ptx4
4831 HPPA running OSF/1 hppa*-*-osf*
4832 Atari TT running SVR4 m68*-*-sysv4*
4833 RS/6000 LynxOS rs6000-*-lynxos*
4837 OS/9000 i[34]86-*-os9k
4838 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4841 * Hitachi SH7000 and E7000-PC ICE support
4843 There is now support for communicating with the Hitachi E7000-PC ICE.
4844 This is available automatically when GDB is configured for the SH.
4848 As usual, a variety of small fixes and improvements, both generic
4849 and configuration-specific. See the ChangeLog for more detail.
4851 *** Changes in GDB-4.12:
4853 * Irix 5 is now supported
4857 GDB-4.12 on the HPPA has a number of changes which make it unable
4858 to debug the output from the currently released versions of GCC and
4859 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4860 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4861 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4864 *** Changes in GDB-4.11:
4866 * User visible changes:
4870 The "set remotedebug" option is now consistent between the mips remote
4871 target, remote targets using the gdb-specific protocol, UDI (AMD's
4872 debug protocol for the 29k) and the 88k bug monitor. It is now an
4873 integer specifying a debug level (normally 0 or 1, but 2 means more
4874 debugging info for the mips target).
4876 * DEC Alpha native support
4878 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4879 debug info, but GDB works fairly well with the DEC compiler and should
4880 work with a future GCC release. See the README file for a few
4881 Alpha-specific notes.
4883 * Preliminary thread implementation
4885 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4887 * LynxOS native and target support for 386
4889 This release has been hosted on LynxOS 2.2, and also can be configured
4890 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4893 * Improvements in C++ mangling/demangling.
4895 This release has much better g++ debugging, specifically in name
4896 mangling/demangling, virtual function calls, print virtual table,
4897 call methods, ...etc.
4899 *** Changes in GDB-4.10:
4901 * User visible changes:
4903 Remote debugging using the GDB-specific (`target remote') protocol now
4904 supports the `load' command. This is only useful if you have some
4905 other way of getting the stub to the target system, and you can put it
4906 somewhere in memory where it won't get clobbered by the download.
4908 Filename completion now works.
4910 When run under emacs mode, the "info line" command now causes the
4911 arrow to point to the line specified. Also, "info line" prints
4912 addresses in symbolic form (as well as hex).
4914 All vxworks based targets now support a user settable option, called
4915 vxworks-timeout. This option represents the number of seconds gdb
4916 should wait for responses to rpc's. You might want to use this if
4917 your vxworks target is, perhaps, a slow software simulator or happens
4918 to be on the far side of a thin network line.
4922 This release contains support for using a DEC alpha as a GDB host for
4923 cross debugging. Native alpha debugging is not supported yet.
4926 *** Changes in GDB-4.9:
4930 This is the first GDB release which is accompanied by a matching testsuite.
4931 The testsuite requires installation of dejagnu, which should be available
4932 via ftp from most sites that carry GNU software.
4936 'Cfront' style demangling has had its name changed to 'ARM' style, to
4937 emphasize that it was written from the specifications in the C++ Annotated
4938 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4939 disclaimers, it still generated too much confusion with users attempting to
4940 use gdb with AT&T cfront.
4944 GDB now uses a standard remote interface to a simulator library.
4945 So far, the library contains simulators for the Zilog Z8001/2, the
4946 Hitachi H8/300, H8/500 and Super-H.
4948 * New targets supported
4950 H8/300 simulator h8300-hitachi-hms or h8300hms
4951 H8/500 simulator h8500-hitachi-hms or h8500hms
4952 SH simulator sh-hitachi-hms or sh
4953 Z8000 simulator z8k-zilog-none or z8ksim
4954 IDT MIPS board over serial line mips-idt-ecoff
4956 Cross-debugging to GO32 targets is supported. It requires a custom
4957 version of the i386-stub.c module which is integrated with the
4958 GO32 memory extender.
4960 * New remote protocols
4962 MIPS remote debugging protocol.
4964 * New source languages supported
4966 This version includes preliminary support for Chill, a Pascal like language
4967 used by telecommunications companies. Chill support is also being integrated
4968 into the GNU compiler, but we don't know when it will be publically available.
4971 *** Changes in GDB-4.8:
4973 * HP Precision Architecture supported
4975 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4976 version of this support was available as a set of patches from the
4977 University of Utah. GDB does not support debugging of programs
4978 compiled with the HP compiler, because HP will not document their file
4979 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4980 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4982 Many problems in the preliminary version have been fixed.
4984 * Faster and better demangling
4986 We have improved template demangling and fixed numerous bugs in the GNU style
4987 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4988 character types (wchar_t) are now supported. Demangling of each symbol is now
4989 only done once, and is cached when the symbol table for a file is read in.
4990 This results in a small increase in memory usage for C programs, a moderate
4991 increase in memory usage for C++ programs, and a fantastic speedup in
4994 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4995 from the specifications in the Annotated Reference Manual, which AT&T's
4996 compiler does not actually implement.
4998 * G++ multiple inheritance compiler problem
5000 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5001 inheritance lattices was reworked to properly discover ambiguities. We
5002 recently found an example which causes this new algorithm to fail in a
5003 very subtle way, producing bad debug information for those classes.
5004 The file 'gcc.patch' (in this directory) can be applied to gcc to
5005 circumvent the problem. A future GCC release will contain a complete
5008 The previous G++ debug info problem (mentioned below for the gdb-4.7
5009 release) is fixed in gcc version 2.3.2.
5011 * Improved configure script
5013 The `configure' script will now attempt to guess your system type if
5014 you don't supply a host system type. The old scheme of supplying a
5015 host system triplet is preferable over using this. All the magic is
5016 done in the new `config.guess' script. Examine it for details.
5018 We have also brought our configure script much more in line with the FSF's
5019 version. It now supports the --with-xxx options. In particular,
5020 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5021 The resulting GDB will not be able to read arbitrary object file formats --
5022 only the format ``expected'' to be used on the configured target system.
5023 We hope to make this the default in a future release.
5025 * Documentation improvements
5027 There's new internal documentation on how to modify GDB, and how to
5028 produce clean changes to the code. We implore people to read it
5029 before submitting changes.
5031 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5032 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5033 `info' files are also provided. To build `info' files from scratch,
5034 you will need the latest `makeinfo' release, which will be available in
5035 a future texinfo-X.Y release.
5037 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5038 We're not sure exactly which versions have this problem, but it has
5039 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5040 or better. If that isn't possible, there is a patch in
5041 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5042 around this problem.
5046 GDB now supports array constants that can be used in expressions typed in by
5047 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5048 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5051 The new directory `gdb/sparclite' contains a program that demonstrates
5052 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5054 * New native hosts supported
5056 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5057 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5059 * New targets supported
5061 AMD 29k family via UDI a29k-amd-udi or udi29k
5063 * New file formats supported
5065 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5066 HPUX core files, and SCO 3.2v2 core files.
5070 Attaching to processes now works again; thanks for the many bug reports.
5072 We have also stomped on a bunch of core dumps caused by
5073 printf_filtered("%s") problems.
5075 We eliminated a copyright problem on the rpc and ptrace header files
5076 for VxWorks, which was discovered at the last minute during the 4.7
5077 release. You should now be able to build a VxWorks GDB.
5079 You can now interrupt gdb while an attached process is running. This
5080 will cause the attached process to stop, and give control back to GDB.
5082 We fixed problems caused by using too many file descriptors
5083 for reading symbols from object files and libraries. This was
5084 especially a problem for programs that used many (~100) shared
5087 The `step' command now only enters a subroutine if there is line number
5088 information for the subroutine. Otherwise it acts like the `next'
5089 command. Previously, `step' would enter subroutines if there was
5090 any debugging information about the routine. This avoids problems
5091 when using `cc -g1' on MIPS machines.
5093 * Internal improvements
5095 GDB's internal interfaces have been improved to make it easier to support
5096 debugging of multiple languages in the future.
5098 GDB now uses a common structure for symbol information internally.
5099 Minimal symbols (derived from linkage symbols in object files), partial
5100 symbols (from a quick scan of debug information), and full symbols
5101 contain a common subset of information, making it easier to write
5102 shared code that handles any of them.
5104 * New command line options
5106 We now accept --silent as an alias for --quiet.
5110 The memory-mapped-malloc library is now licensed under the GNU Library
5111 General Public License.
5113 *** Changes in GDB-4.7:
5115 * Host/native/target split
5117 GDB has had some major internal surgery to untangle the support for
5118 hosts and remote targets. Now, when you configure GDB for a remote
5119 target, it will no longer load in all of the support for debugging
5120 local programs on the host. When fully completed and tested, this will
5121 ensure that arbitrary host/target combinations are possible.
5123 The primary conceptual shift is to separate the non-portable code in
5124 GDB into three categories. Host specific code is required any time GDB
5125 is compiled on that host, regardless of the target. Target specific
5126 code relates to the peculiarities of the target, but can be compiled on
5127 any host. Native specific code is everything else: it can only be
5128 built when the host and target are the same system. Child process
5129 handling and core file support are two common `native' examples.
5131 GDB's use of /proc for controlling Unix child processes is now cleaner.
5132 It has been split out into a single module under the `target_ops' vector,
5133 plus two native-dependent functions for each system that uses /proc.
5135 * New hosts supported
5137 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5138 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5139 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5141 * New targets supported
5143 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5144 68030 and CPU32 m68030-*-*, m68332-*-*
5146 * New native hosts supported
5148 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5149 (386bsd is not well tested yet)
5150 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5152 * New file formats supported
5154 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5155 supports reading of `a.out.adobe' object files, which are an a.out
5156 format extended with minimal information about multiple sections.
5160 `show copying' is the same as the old `info copying'.
5161 `show warranty' is the same as `info warrantee'.
5162 These were renamed for consistency. The old commands continue to work.
5164 `info handle' is a new alias for `info signals'.
5166 You can now define pre-command hooks, which attach arbitrary command
5167 scripts to any command. The commands in the hook will be executed
5168 prior to the user's command. You can also create a hook which will be
5169 executed whenever the program stops. See gdb.texinfo.
5173 We now deal with Cfront style name mangling, and can even extract type
5174 info from mangled symbols. GDB can automatically figure out which
5175 symbol mangling style your C++ compiler uses.
5177 Calling of methods and virtual functions has been improved as well.
5181 The crash that occured when debugging Sun Ansi-C compiled binaries is
5182 fixed. This was due to mishandling of the extra N_SO stabs output
5185 We also finally got Ultrix 4.2 running in house, and fixed core file
5186 support, with help from a dozen people on the net.
5188 John M. Farrell discovered that the reason that single-stepping was so
5189 slow on all of the Mips based platforms (primarily SGI and DEC) was
5190 that we were trying to demangle and lookup a symbol used for internal
5191 purposes on every instruction that was being stepped through. Changing
5192 the name of that symbol so that it couldn't be mistaken for a C++
5193 mangled symbol sped things up a great deal.
5195 Rich Pixley sped up symbol lookups in general by getting much smarter
5196 about when C++ symbol mangling is necessary. This should make symbol
5197 completion (TAB on the command line) much faster. It's not as fast as
5198 we'd like, but it's significantly faster than gdb-4.6.
5202 A new user controllable variable 'call_scratch_address' can
5203 specify the location of a scratch area to be used when GDB
5204 calls a function in the target. This is necessary because the
5205 usual method of putting the scratch area on the stack does not work
5206 in systems that have separate instruction and data spaces.
5208 We integrated changes to support the 29k UDI (Universal Debugger
5209 Interface), but discovered at the last minute that we didn't have all
5210 of the appropriate copyright paperwork. We are working with AMD to
5211 resolve this, and hope to have it available soon.
5215 We have sped up the remote serial line protocol, especially for targets
5216 with lots of registers. It now supports a new `expedited status' ('T')
5217 message which can be used in place of the existing 'S' status message.
5218 This allows the remote stub to send only the registers that GDB
5219 needs to make a quick decision about single-stepping or conditional
5220 breakpoints, eliminating the need to fetch the entire register set for
5221 each instruction being stepped through.
5223 The GDB remote serial protocol now implements a write-through cache for
5224 registers, only re-reading the registers if the target has run.
5226 There is also a new remote serial stub for SPARC processors. You can
5227 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5228 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5229 processor with a serial port.
5233 Configure.in files have become much easier to read and modify. A new
5234 `table driven' format makes it more obvious what configurations are
5235 supported, and what files each one uses.
5239 There is a new opcodes library which will eventually contain all of the
5240 disassembly routines and opcode tables. At present, it only contains
5241 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5242 disassembler (binutils/objdump) to share these routines.
5244 The libiberty library is now copylefted under the GNU Library General
5245 Public License. This allows more liberal use, and was done so libg++
5246 can use it. This makes no difference to GDB, since the Library License
5247 grants all the rights from the General Public License.
5251 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5252 reference to the stabs symbol info used by the debugger. It is (as far
5253 as we know) the only published document on this fascinating topic. We
5254 encourage you to read it, compare it to the stabs information on your
5255 system, and send improvements on the document in general (to
5256 bug-gdb@prep.ai.mit.edu).
5258 And, of course, many bugs have been fixed.
5261 *** Changes in GDB-4.6:
5263 * Better support for C++ function names
5265 GDB now accepts as input the "demangled form" of C++ overloaded function
5266 names and member function names, and can do command completion on such names
5267 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5268 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5269 Make use of command completion, it is your friend.
5271 GDB also now accepts a variety of C++ mangled symbol formats. They are
5272 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5273 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5274 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5275 for the list of formats.
5277 * G++ symbol mangling problem
5279 Recent versions of gcc have a bug in how they emit debugging information for
5280 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5281 directory) can be applied to gcc to fix the problem. Alternatively, if you
5282 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5283 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5284 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5287 * New 'maintenance' command
5289 All of the commands related to hacking GDB internals have been moved out of
5290 the main command set, and now live behind the 'maintenance' command. This
5291 can also be abbreviated as 'mt'. The following changes were made:
5293 dump-me -> maintenance dump-me
5294 info all-breakpoints -> maintenance info breakpoints
5295 printmsyms -> maintenance print msyms
5296 printobjfiles -> maintenance print objfiles
5297 printpsyms -> maintenance print psymbols
5298 printsyms -> maintenance print symbols
5300 The following commands are new:
5302 maintenance demangle Call internal GDB demangler routine to
5303 demangle a C++ link name and prints the result.
5304 maintenance print type Print a type chain for a given symbol
5306 * Change to .gdbinit file processing
5308 We now read the $HOME/.gdbinit file before processing the argv arguments
5309 (e.g. reading symbol files or core files). This allows global parameters to
5310 be set, which will apply during the symbol reading. The ./.gdbinit is still
5311 read after argv processing.
5313 * New hosts supported
5315 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5317 GNU/Linux support i386-unknown-linux or linux
5319 We are also including code to support the HP/PA running BSD and HPUX. This
5320 is almost guaranteed not to work, as we didn't have time to test or build it
5321 for this release. We are including it so that the more adventurous (or
5322 masochistic) of you can play with it. We also had major problems with the
5323 fact that the compiler that we got from HP doesn't support the -g option.
5326 * New targets supported
5328 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5330 * More smarts about finding #include files
5332 GDB now remembers the compilation directory for all include files, and for
5333 all files from which C is generated (like yacc and lex sources). This
5334 greatly improves GDB's ability to find yacc/lex sources, and include files,
5335 especially if you are debugging your program from a directory different from
5336 the one that contains your sources.
5338 We also fixed a bug which caused difficulty with listing and setting
5339 breakpoints in include files which contain C code. (In the past, you had to
5340 try twice in order to list an include file that you hadn't looked at before.)
5342 * Interesting infernals change
5344 GDB now deals with arbitrary numbers of sections, where the symbols for each
5345 section must be relocated relative to that section's landing place in the
5346 target's address space. This work was needed to support ELF with embedded
5347 stabs used by Solaris-2.0.
5349 * Bug fixes (of course!)
5351 There have been loads of fixes for the following things:
5352 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5353 i960, stabs, DOS(GO32), procfs, etc...
5355 See the ChangeLog for details.
5357 *** Changes in GDB-4.5:
5359 * New machines supported (host and target)
5361 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5363 SGI Irix-4.x mips-sgi-irix4 or iris4
5365 * New malloc package
5367 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5368 Mmalloc is capable of handling mutiple heaps of memory. It is also
5369 capable of saving a heap to a file, and then mapping it back in later.
5370 This can be used to greatly speedup the startup of GDB by using a
5371 pre-parsed symbol table which lives in a mmalloc managed heap. For
5372 more details, please read mmalloc/mmalloc.texi.
5376 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5377 'help info proc' for details.
5379 * MIPS ecoff symbol table format
5381 The code that reads MIPS symbol table format is now supported on all hosts.
5382 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5385 * File name changes for MS-DOS
5387 Many files in the config directories have been renamed to make it easier to
5388 support GDB on MS-DOSe systems (which have very restrictive file name
5389 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5390 environment) is close to working but has some remaining problems. Note
5391 that debugging of DOS programs is not supported, due to limitations
5392 in the ``operating system'', but it can be used to host cross-debugging.
5394 * Cross byte order fixes
5396 Many fixes have been made to support cross debugging of Sparc and MIPS
5397 targets from hosts whose byte order differs.
5399 * New -mapped and -readnow options
5401 If memory-mapped files are available on your system through the 'mmap'
5402 system call, you can use the -mapped option on the `file' or
5403 `symbol-file' commands to cause GDB to write the symbols from your
5404 program into a reusable file. If the program you are debugging is
5405 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5406 Future GDB debugging sessions will notice the presence of this file,
5407 and will quickly map in symbol information from it, rather than reading
5408 the symbol table from the executable program. Using the '-mapped'
5409 option in a GDB `file' or `symbol-file' command has the same effect as
5410 starting GDB with the '-mapped' command-line option.
5412 You can cause GDB to read the entire symbol table immediately by using
5413 the '-readnow' option with any of the commands that load symbol table
5414 information (or on the GDB command line). This makes the command
5415 slower, but makes future operations faster.
5417 The -mapped and -readnow options are typically combined in order to
5418 build a `fred.syms' file that contains complete symbol information.
5419 A simple GDB invocation to do nothing but build a `.syms' file for future
5422 gdb -batch -nx -mapped -readnow programname
5424 The `.syms' file is specific to the host machine on which GDB is run.
5425 It holds an exact image of GDB's internal symbol table. It cannot be
5426 shared across multiple host platforms.
5428 * longjmp() handling
5430 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5431 siglongjmp() without losing control. This feature has not yet been ported to
5432 all systems. It currently works on many 386 platforms, all MIPS-based
5433 platforms (SGI, DECstation, etc), and Sun3/4.
5437 Preliminary work has been put in to support the new Solaris OS from Sun. At
5438 this time, it can control and debug processes, but it is not capable of
5443 As always, many many bug fixes. The major areas were with g++, and mipsread.
5444 People using the MIPS-based platforms should experience fewer mysterious
5445 crashes and trashed symbol tables.
5447 *** Changes in GDB-4.4:
5449 * New machines supported (host and target)
5451 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5453 BSD Reno on Vax vax-dec-bsd
5454 Ultrix on Vax vax-dec-ultrix
5456 * New machines supported (target)
5458 AMD 29000 embedded, using EBMON a29k-none-none
5462 GDB continues to improve its handling of C++. `References' work better.
5463 The demangler has also been improved, and now deals with symbols mangled as
5464 per the Annotated C++ Reference Guide.
5466 GDB also now handles `stabs' symbol information embedded in MIPS
5467 `ecoff' symbol tables. Since the ecoff format was not easily
5468 extensible to handle new languages such as C++, this appeared to be a
5469 good way to put C++ debugging info into MIPS binaries. This option
5470 will be supported in the GNU C compiler, version 2, when it is
5473 * New features for SVR4
5475 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5476 shared libraries. Debugging dynamically linked programs should present
5477 only minor differences from debugging statically linked programs.
5479 The `info proc' command will print out information about any process
5480 on an SVR4 system (including the one you are debugging). At the moment,
5481 it prints the address mappings of the process.
5483 If you bring up GDB on another SVR4 system, please send mail to
5484 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5486 * Better dynamic linking support in SunOS
5488 Reading symbols from shared libraries which contain debugging symbols
5489 now works properly. However, there remain issues such as automatic
5490 skipping of `transfer vector' code during function calls, which
5491 make it harder to debug code in a shared library, than to debug the
5492 same code linked statically.
5496 GDB is now using the latest `getopt' routines from the FSF. This
5497 version accepts the -- prefix for options with long names. GDB will
5498 continue to accept the old forms (-option and +option) as well.
5499 Various single letter abbreviations for options have been explicity
5500 added to the option table so that they won't get overshadowed in the
5501 future by other options that begin with the same letter.
5505 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5506 Many assorted bugs have been handled. Many more remain to be handled.
5507 See the various ChangeLog files (primarily in gdb and bfd) for details.
5510 *** Changes in GDB-4.3:
5512 * New machines supported (host and target)
5514 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5515 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5516 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5518 * Almost SCO Unix support
5520 We had hoped to support:
5521 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5522 (except for core file support), but we discovered very late in the release
5523 that it has problems with process groups that render gdb unusable. Sorry
5524 about that. I encourage people to fix it and post the fixes.
5526 * Preliminary ELF and DWARF support
5528 GDB can read ELF object files on System V Release 4, and can handle
5529 debugging records for C, in DWARF format, in ELF files. This support
5530 is preliminary. If you bring up GDB on another SVR4 system, please
5531 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5536 GDB now uses the latest `readline' library. One user-visible change
5537 is that two tabs will list possible command completions, which previously
5538 required typing M-? (meta-question mark, or ESC ?).
5542 The `stepi' bug that many of you noticed has been squashed.
5543 Many bugs in C++ have been handled. Many more remain to be handled.
5544 See the various ChangeLog files (primarily in gdb and bfd) for details.
5546 * State of the MIPS world (in case you wondered):
5548 GDB can understand the symbol tables emitted by the compilers
5549 supplied by most vendors of MIPS-based machines, including DEC. These
5550 symbol tables are in a format that essentially nobody else uses.
5552 Some versions of gcc come with an assembler post-processor called
5553 mips-tfile. This program is required if you want to do source-level
5554 debugging of gcc-compiled programs. I believe FSF does not ship
5555 mips-tfile with gcc version 1, but it will eventually come with gcc
5558 Debugging of g++ output remains a problem. g++ version 1.xx does not
5559 really support it at all. (If you're lucky, you should be able to get
5560 line numbers and stack traces to work, but no parameters or local
5561 variables.) With some work it should be possible to improve the
5564 When gcc version 2 is released, you will have somewhat better luck.
5565 However, even then you will get confusing results for inheritance and
5568 We will eventually provide full debugging of g++ output on
5569 DECstations. This will probably involve some kind of stabs-in-ecoff
5570 encapulation, but the details have not been worked out yet.
5573 *** Changes in GDB-4.2:
5575 * Improved configuration
5577 Only one copy of `configure' exists now, and it is not self-modifying.
5578 Porting BFD is simpler.
5582 The `step' and `next' commands now only stop at the first instruction
5583 of a source line. This prevents the multiple stops that used to occur
5584 in switch statements, for-loops, etc. `Step' continues to stop if a
5585 function that has debugging information is called within the line.
5589 Lots of small bugs fixed. More remain.
5591 * New host supported (not target)
5593 Intel 386 PC clone running Mach i386-none-mach
5596 *** Changes in GDB-4.1:
5598 * Multiple source language support
5600 GDB now has internal scaffolding to handle several source languages.
5601 It determines the type of each source file from its filename extension,
5602 and will switch expression parsing and number formatting to match the
5603 language of the function in the currently selected stack frame.
5604 You can also specifically set the language to be used, with
5605 `set language c' or `set language modula-2'.
5609 GDB now has preliminary support for the GNU Modula-2 compiler,
5610 currently under development at the State University of New York at
5611 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5612 continue through the fall of 1991 and into 1992.
5614 Other Modula-2 compilers are currently not supported, and attempting to
5615 debug programs compiled with them will likely result in an error as the
5616 symbol table is read. Feel free to work on it, though!
5618 There are hooks in GDB for strict type checking and range checking,
5619 in the `Modula-2 philosophy', but they do not currently work.
5623 GDB can now write to executable and core files (e.g. patch
5624 a variable's value). You must turn this switch on, specify
5625 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5626 by assigning a new value to a variable. Modifications take
5629 * Automatic SunOS shared library reading
5631 When you run your program, GDB automatically determines where its
5632 shared libraries (if any) have been loaded, and reads their symbols.
5633 The `share' command is no longer needed. This also works when
5634 examining core files.
5638 You can specify the number of lines that the `list' command shows.
5641 * New machines supported (host and target)
5643 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5644 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5645 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5647 * New hosts supported (not targets)
5649 IBM RT/PC: romp-ibm-aix or rtpc
5651 * New targets supported (not hosts)
5653 AMD 29000 embedded with COFF a29k-none-coff
5654 AMD 29000 embedded with a.out a29k-none-aout
5655 Ultracomputer remote kernel debug a29k-nyu-kern
5657 * New remote interfaces
5663 *** Changes in GDB-4.0:
5667 Wide output is wrapped at good places to make the output more readable.
5669 Gdb now supports cross-debugging from a host machine of one type to a
5670 target machine of another type. Communication with the target system
5671 is over serial lines. The ``target'' command handles connecting to the
5672 remote system; the ``load'' command will download a program into the
5673 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5674 also supports debugging of realtime processes running under VxWorks,
5675 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5676 stub on the target system.
5678 New CPUs supported include the AMD 29000 and Intel 960.
5680 GDB now reads object files and symbol tables via a ``binary file''
5681 library, which allows a single copy of GDB to debug programs of multiple
5682 object file types such as a.out and coff.
5684 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5685 refcard.dvi and refcard.ps are available to format it).
5688 * Control-Variable user interface simplified
5690 All variables that control the operation of the debugger can be set
5691 by the ``set'' command, and displayed by the ``show'' command.
5693 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5694 ``Show prompt'' produces the response:
5695 Gdb's prompt is new-gdb=>.
5697 What follows are the NEW set commands. The command ``help set'' will
5698 print a complete list of old and new set commands. ``help set FOO''
5699 will give a longer description of the variable FOO. ``show'' will show
5700 all of the variable descriptions and their current settings.
5702 confirm on/off: Enables warning questions for operations that are
5703 hard to recover from, e.g. rerunning the program while
5704 it is already running. Default is ON.
5706 editing on/off: Enables EMACS style command line editing
5707 of input. Previous lines can be recalled with
5708 control-P, the current line can be edited with control-B,
5709 you can search for commands with control-R, etc.
5712 history filename NAME: NAME is where the gdb command history
5713 will be stored. The default is .gdb_history,
5714 or the value of the environment variable
5717 history size N: The size, in commands, of the command history. The
5718 default is 256, or the value of the environment variable
5721 history save on/off: If this value is set to ON, the history file will
5722 be saved after exiting gdb. If set to OFF, the
5723 file will not be saved. The default is OFF.
5725 history expansion on/off: If this value is set to ON, then csh-like
5726 history expansion will be performed on
5727 command line input. The default is OFF.
5729 radix N: Sets the default radix for input and output. It can be set
5730 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5731 in the current radix, so "set radix 10" is always a no-op.
5733 height N: This integer value is the number of lines on a page. Default
5734 is 24, the current `stty rows'' setting, or the ``li#''
5735 setting from the termcap entry matching the environment
5738 width N: This integer value is the number of characters on a line.
5739 Default is 80, the current `stty cols'' setting, or the ``co#''
5740 setting from the termcap entry matching the environment
5743 Note: ``set screensize'' is obsolete. Use ``set height'' and
5744 ``set width'' instead.
5746 print address on/off: Print memory addresses in various command displays,
5747 such as stack traces and structure values. Gdb looks
5748 more ``symbolic'' if you turn this off; it looks more
5749 ``machine level'' with it on. Default is ON.
5751 print array on/off: Prettyprint arrays. New convenient format! Default
5754 print demangle on/off: Print C++ symbols in "source" form if on,
5757 print asm-demangle on/off: Same, for assembler level printouts
5760 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5763 * Support for Epoch Environment.
5765 The epoch environment is a version of Emacs v18 with windowing. One
5766 new command, ``inspect'', is identical to ``print'', except that if you
5767 are running in the epoch environment, the value is printed in its own
5771 * Support for Shared Libraries
5773 GDB can now debug programs and core files that use SunOS shared libraries.
5774 Symbols from a shared library cannot be referenced
5775 before the shared library has been linked with the program (this
5776 happens after you type ``run'' and before the function main() is entered).
5777 At any time after this linking (including when examining core files
5778 from dynamically linked programs), gdb reads the symbols from each
5779 shared library when you type the ``sharedlibrary'' command.
5780 It can be abbreviated ``share''.
5782 sharedlibrary REGEXP: Load shared object library symbols for files
5783 matching a unix regular expression. No argument
5784 indicates to load symbols for all shared libraries.
5786 info sharedlibrary: Status of loaded shared libraries.
5791 A watchpoint stops execution of a program whenever the value of an
5792 expression changes. Checking for this slows down execution
5793 tremendously whenever you are in the scope of the expression, but is
5794 quite useful for catching tough ``bit-spreader'' or pointer misuse
5795 problems. Some machines such as the 386 have hardware for doing this
5796 more quickly, and future versions of gdb will use this hardware.
5798 watch EXP: Set a watchpoint (breakpoint) for an expression.
5800 info watchpoints: Information about your watchpoints.
5802 delete N: Deletes watchpoint number N (same as breakpoints).
5803 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5804 enable N: Re-enables watchpoint number N (same as breakpoints).
5807 * C++ multiple inheritance
5809 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5812 * C++ exception handling
5814 Gdb now supports limited C++ exception handling. Besides the existing
5815 ability to breakpoint on an exception handler, gdb can breakpoint on
5816 the raising of an exception (before the stack is peeled back to the
5819 catch FOO: If there is a FOO exception handler in the dynamic scope,
5820 set a breakpoint to catch exceptions which may be raised there.
5821 Multiple exceptions (``catch foo bar baz'') may be caught.
5823 info catch: Lists all exceptions which may be caught in the
5824 current stack frame.
5827 * Minor command changes
5829 The command ``call func (arg, arg, ...)'' now acts like the print
5830 command, except it does not print or save a value if the function's result
5831 is void. This is similar to dbx usage.
5833 The ``up'' and ``down'' commands now always print the frame they end up
5834 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5835 frames without printing.
5837 * New directory command
5839 'dir' now adds directories to the FRONT of the source search path.
5840 The path starts off empty. Source files that contain debug information
5841 about the directory in which they were compiled can be found even
5842 with an empty path; Sun CC and GCC include this information. If GDB can't
5843 find your source file in the current directory, type "dir .".
5845 * Configuring GDB for compilation
5847 For normal use, type ``./configure host''. See README or gdb.texinfo
5850 GDB now handles cross debugging. If you are remotely debugging between
5851 two different machines, type ``./configure host -target=targ''.
5852 Host is the machine where GDB will run; targ is the machine
5853 where the program that you are debugging will run.