1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.8
6 * GDB now supports hardware watchpoints on x86 GNU Hurd.
10 ** You can now access frame registers from Python scripts.
11 ** New attribute 'producer' for gdb.Symtab objects.
12 ** gdb.Objfile objects have a new attribute "progspace",
13 which is the gdb.Progspace object of the containing program space.
14 ** gdb.Objfile objects have a new attribute "owner".
15 ** gdb.Objfile objects have a new attribute "build_id",
16 which is the build ID generated when the file was built.
17 ** gdb.Objfile objects have a new method "add_separate_debug_file".
18 ** A new event "gdb.clear_objfiles" has been added, triggered when
19 selecting a new file to debug.
20 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
21 ** New function gdb.lookup_objfile.
23 New events which are triggered when GDB modifies the state of the
26 ** gdb.events.inferior_call_pre: Function call is about to be made.
27 ** gdb.events.inferior_call_post: Function call has just been made.
28 ** gdb.events.memory_changed: A memory location has been altered.
29 ** gdb.events.register_changed: A register has been altered.
31 * New Python-based convenience functions:
33 ** $_caller_is(name [, number_of_frames])
34 ** $_caller_matches(regexp [, number_of_frames])
35 ** $_any_caller_is(name [, number_of_frames])
36 ** $_any_caller_matches(regexp [, number_of_frames])
38 * GDB now supports the compilation and injection of source code into
39 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
40 to compile the source code to object code, and if successful, inject
41 and execute that code within the current context of the inferior.
42 Currently the C language is supported. The commands used to
43 interface with this new feature are:
45 compile code [-raw|-r] [--] [source code]
46 compile file [-raw|-r] filename
50 queue-signal signal-name-or-number
51 Queue a signal to be delivered to the thread when it is resumed.
53 add-auto-load-scripts-directory directory
54 Add entries to the list of directories from which to load auto-loaded
57 maint print user-registers
58 List all currently available "user" registers.
60 compile code [-r|-raw] [--] [source code]
61 Compile, inject, and execute in the inferior the executable object
62 code produced by compiling the provided source code.
64 compile file [-r|-raw] filename
65 Compile and inject into the inferior the executable object code
66 produced by compiling the source code stored in the filename
69 * On resume, GDB now always passes the signal the program had stopped
70 for to the thread the signal was sent to, even if the user changed
71 threads before resuming. Previously GDB would often (but not
72 always) deliver the signal to the thread that happens to be current
75 * Conversely, the "signal" command now consistently delivers the
76 requested signal to the current thread. GDB now asks for
77 confirmation if the program had stopped for a signal and the user
78 switched threads meanwhile.
80 * "breakpoint always-inserted" modes "off" and "auto" merged.
82 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
83 won't remove breakpoints from the target until all threads stop,
84 even in non-stop mode. The "auto" mode has been removed, and "off"
85 is now the default mode.
89 ** The -list-thread-groups command outputs an exit-code field for
90 inferiors that have exited.
94 Support for these obsolete configurations has been removed.
96 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
97 SGI Irix-5.x mips-*-irix5*
98 SGI Irix-6.x mips-*-irix6*
99 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
100 VAX running Ultrix vax-*-ultrix*
102 *** Changes in GDB 7.8
104 * New command line options
107 This is an alias for the --data-directory option.
109 * GDB supports printing and modifying of variable length automatic arrays
110 as specified in ISO C99.
112 * The ARM simulator now supports instruction level tracing
113 with or without disassembly.
117 GDB now has support for scripting using Guile. Whether this is
118 available is determined at configure time.
119 Guile version 2.0 or greater is required.
120 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
122 * New commands (for set/show, see "New options" below)
126 Invoke CODE by passing it to the Guile interpreter.
130 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
132 info auto-load guile-scripts [regexp]
133 Print the list of automatically loaded Guile scripts.
135 * The source command is now capable of sourcing Guile scripts.
136 This feature is dependent on the debugger being built with Guile support.
140 set print symbol-loading (off|brief|full)
141 show print symbol-loading
142 Control whether to print informational messages when loading symbol
143 information for a file. The default is "full", but when debugging
144 programs with large numbers of shared libraries the amount of output
147 set guile print-stack (none|message|full)
148 show guile print-stack
149 Show a stack trace when an error is encountered in a Guile script.
151 set auto-load guile-scripts (on|off)
152 show auto-load guile-scripts
153 Control auto-loading of Guile script files.
155 maint ada set ignore-descriptive-types (on|off)
156 maint ada show ignore-descriptive-types
157 Control whether the debugger should ignore descriptive types in Ada
158 programs. The default is not to ignore the descriptive types. See
159 the user manual for more details on descriptive types and the intended
160 usage of this option.
162 set auto-connect-native-target
164 Control whether GDB is allowed to automatically connect to the
165 native target for the run, attach, etc. commands when not connected
166 to any target yet. See also "target native" below.
168 set record btrace replay-memory-access (read-only|read-write)
169 show record btrace replay-memory-access
170 Control what memory accesses are allowed during replay.
172 maint set target-async (on|off)
173 maint show target-async
174 This controls whether GDB targets operate in synchronous or
175 asynchronous mode. Normally the default is asynchronous, if it is
176 available; but this can be changed to more easily debug problems
177 occurring only in synchronous mode.
179 set mi-async (on|off)
181 Control whether MI asynchronous mode is preferred. This supersedes
182 "set target-async" of previous GDB versions.
184 * "set target-async" is deprecated as a CLI option and is now an alias
185 for "set mi-async" (only puts MI into async mode).
187 * Background execution commands (e.g., "c&", "s&", etc.) are now
188 possible ``out of the box'' if the target supports them. Previously
189 the user would need to explicitly enable the possibility with the
190 "set target-async on" command.
192 * New features in the GDB remote stub, GDBserver
194 ** New option --debug-format=option1[,option2,...] allows one to add
195 additional text to each output. At present only timestamps
196 are supported: --debug-format=timestamps.
197 Timestamps can also be turned on with the
198 "monitor set debug-format timestamps" command from GDB.
200 * The 'record instruction-history' command now starts counting instructions
201 at one. This also affects the instruction ranges reported by the
202 'record function-call-history' command when given the /i modifier.
204 * The command 'record function-call-history' supports a new modifier '/c' to
205 indent the function names based on their call stack depth.
206 The fields for the '/i' and '/l' modifier have been reordered.
207 The source line range is now prefixed with 'at'.
208 The instruction range is now prefixed with 'inst'.
209 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
210 "record instruction-history" and "list" commands.
212 * The ranges given as arguments to the 'record function-call-history' and
213 'record instruction-history' commands are now inclusive.
215 * The btrace record target now supports the 'record goto' command.
216 For locations inside the execution trace, the back trace is computed
217 based on the information stored in the execution trace.
219 * The btrace record target supports limited reverse execution and replay.
220 The target does not record data and therefore does not allow reading
223 * The "catch syscall" command now works on s390*-linux* targets.
225 * The "compare-sections" command is no longer specific to target
226 remote. It now works with all targets.
228 * All native targets are now consistently called "native".
229 Consequently, the "target child", "target GNU", "target djgpp",
230 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
231 commands have been replaced with "target native". The QNX/NTO port
232 leaves the "procfs" target in place and adds a "native" target for
233 consistency with other ports. The impact on users should be minimal
234 as these commands previously either throwed an error, or were
235 no-ops. The target's name is visible in the output of the following
236 commands: "help target", "info target", "info files", "maint print
239 * The "target native" command now connects to the native target. This
240 can be used to launch native programs even when "set
241 auto-connect-native-target" is set to off.
243 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.
245 * Support for Intel(R) AVX-512 registers on GNU/Linux.
246 Support displaying and modifying Intel(R) AVX-512 registers
247 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
251 qXfer:btrace:read's annex
252 The qXfer:btrace:read packet supports a new annex 'delta' to read
253 branch trace incrementally.
257 ** Valid Python operations on gdb.Value objects representing
258 structs/classes invoke the corresponding overloaded operators if
260 ** New `Xmethods' feature in the Python API. Xmethods are
261 additional methods or replacements for existing methods of a C++
262 class. This feature is useful for those cases where a method
263 defined in C++ source code could be inlined or optimized out by
264 the compiler, making it unavailable to GDB.
267 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
269 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
270 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
271 its alias "share", instead.
273 * The commands "set remotebaud" and "show remotebaud" are no longer
274 supported. Use "set serial baud" and "show serial baud" (respectively)
279 ** A new option "-gdb-set mi-async" replaces "-gdb-set
280 target-async". The latter is left as a deprecated alias of the
281 former for backward compatibility. If the target supports it,
282 CLI background execution commands are now always possible by
283 default, independently of whether the frontend stated a
284 preference for asynchronous execution with "-gdb-set mi-async".
285 Previously "-gdb-set target-async off" affected both MI execution
286 commands and CLI execution commands.
288 *** Changes in GDB 7.7
290 * Improved support for process record-replay and reverse debugging on
291 arm*-linux* targets. Support for thumb32 and syscall instruction
292 recording has been added.
294 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
296 * GDB now supports Fission DWP file format version 2.
297 http://gcc.gnu.org/wiki/DebugFission
299 * New convenience function "$_isvoid", to check whether an expression
300 is void. A void expression is an expression where the type of the
301 result is "void". For example, some convenience variables may be
302 "void" when evaluated (e.g., "$_exitcode" before the execution of
303 the program being debugged; or an undefined convenience variable).
304 Another example, when calling a function whose return type is
307 * The "maintenance print objfiles" command now takes an optional regexp.
309 * The "catch syscall" command now works on arm*-linux* targets.
311 * GDB now consistently shows "<not saved>" when printing values of
312 registers the debug info indicates have not been saved in the frame
313 and there's nowhere to retrieve them from
314 (callee-saved/call-clobbered registers):
319 (gdb) info registers rax
322 Before, the former would print "<optimized out>", and the latter
323 "*value not available*".
325 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
330 ** Frame filters and frame decorators have been added.
331 ** Temporary breakpoints are now supported.
332 ** Line tables representation has been added.
333 ** New attribute 'parent_type' for gdb.Field objects.
334 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
335 ** New attribute 'name' for gdb.Type objects.
339 Nios II ELF nios2*-*-elf
340 Nios II GNU/Linux nios2*-*-linux
341 Texas Instruments MSP430 msp430*-*-elf
343 * Removed native configurations
345 Support for these a.out NetBSD and OpenBSD obsolete configurations has
346 been removed. ELF variants of these configurations are kept supported.
348 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
349 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
350 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
351 i[34567]86-*-openbsd3.[0-3]
352 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
353 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
354 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
358 Like "catch throw", but catches a re-thrown exception.
360 Renamed from old "maint check-symtabs".
362 Perform consistency checks on symtabs.
364 Expand symtabs matching an optional regexp.
367 Display the details of GDB configure-time options.
369 maint set|show per-command
370 maint set|show per-command space
371 maint set|show per-command time
372 maint set|show per-command symtab
373 Enable display of per-command gdb resource usage.
375 remove-symbol-file FILENAME
376 remove-symbol-file -a ADDRESS
377 Remove a symbol file added via add-symbol-file. The file to remove
378 can be identified by its filename or by an address that lies within
379 the boundaries of this symbol file in memory.
382 info exceptions REGEXP
383 Display the list of Ada exceptions defined in the program being
384 debugged. If provided, only the exceptions whose names match REGEXP
389 set debug symfile off|on
391 Control display of debugging info regarding reading symbol files and
392 symbol tables within those files
394 set print raw frame-arguments
395 show print raw frame-arguments
396 Set/show whether to print frame arguments in raw mode,
397 disregarding any defined pretty-printers.
399 set remote trace-status-packet
400 show remote trace-status-packet
401 Set/show the use of remote protocol qTStatus packet.
405 Control display of debugging messages related to Nios II targets.
409 Control whether target-assisted range stepping is enabled.
411 set startup-with-shell
412 show startup-with-shell
413 Specifies whether Unix child processes are started via a shell or
418 Use the target memory cache for accesses to the code segment. This
419 improves performance of remote debugging (particularly disassembly).
421 * You can now use a literal value 'unlimited' for options that
422 interpret 0 or -1 as meaning "unlimited". E.g., "set
423 trace-buffer-size unlimited" is now an alias for "set
424 trace-buffer-size -1" and "set height unlimited" is now an alias for
427 * The "set debug symtab-create" debugging option of GDB has been changed to
428 accept a verbosity level. 0 means "off", 1 provides basic debugging
429 output, and values of 2 or greater provides more verbose output.
431 * New command-line options
433 Display the details of GDB configure-time options.
435 * The command 'tsave' can now support new option '-ctf' to save trace
436 buffer in Common Trace Format.
438 * Newly installed $prefix/bin/gcore acts as a shell interface for the
441 * GDB now implements the the C++ 'typeid' operator.
443 * The new convenience variable $_exception holds the exception being
444 thrown or caught at an exception-related catchpoint.
446 * The exception-related catchpoints, like "catch throw", now accept a
447 regular expression which can be used to filter exceptions by type.
449 * The new convenience variable $_exitsignal is automatically set to
450 the terminating signal number when the program being debugged dies
451 due to an uncaught signal.
455 ** All MI commands now accept an optional "--language" option.
456 Support for this feature can be verified by using the "-list-features"
457 command, which should contain "language-option".
459 ** The new command -info-gdb-mi-command allows the user to determine
460 whether a GDB/MI command is supported or not.
462 ** The "^error" result record returned when trying to execute an undefined
463 GDB/MI command now provides a variable named "code" whose content is the
464 "undefined-command" error code. Support for this feature can be verified
465 by using the "-list-features" command, which should contain
466 "undefined-command-error-code".
468 ** The -trace-save MI command can optionally save trace buffer in Common
471 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
473 ** The command -data-list-register-values now accepts an optional
474 "--skip-unavailable" option. When used, only the available registers
477 ** The new command -trace-frame-collected dumps collected variables,
478 computed expressions, tvars, memory and registers in a traceframe.
480 ** The commands -stack-list-locals, -stack-list-arguments and
481 -stack-list-variables now accept an option "--skip-unavailable".
482 When used, only the available locals or arguments are displayed.
484 ** The -exec-run command now accepts an optional "--start" option.
485 When used, the command follows the same semantics as the "start"
486 command, stopping the program's execution at the start of its
487 main subprogram. Support for this feature can be verified using
488 the "-list-features" command, which should contain
489 "exec-run-start-option".
491 ** The new commands -catch-assert and -catch-exceptions insert
492 catchpoints stopping the program when Ada exceptions are raised.
494 ** The new command -info-ada-exceptions provides the equivalent of
495 the new "info exceptions" command.
497 * New system-wide configuration scripts
498 A GDB installation now provides scripts suitable for use as system-wide
499 configuration scripts for the following systems:
503 * GDB now supports target-assigned range stepping with remote targets.
504 This improves the performance of stepping source lines by reducing
505 the number of control packets from/to GDB. See "New remote packets"
508 * GDB now understands the element 'tvar' in the XML traceframe info.
509 It has the id of the collected trace state variables.
511 * On S/390 targets that provide the transactional-execution feature,
512 the program interruption transaction diagnostic block (TDB) is now
513 represented as a number of additional "registers" in GDB.
519 The vCont packet supports a new 'r' action, that tells the remote
520 stub to step through an address range itself, without GDB
521 involvemement at each single-step.
523 qXfer:libraries-svr4:read's annex
524 The previously unused annex of the qXfer:libraries-svr4:read packet
525 is now used to support passing an argument list. The remote stub
526 reports support for this argument list to GDB's qSupported query.
527 The defined arguments are "start" and "prev", used to reduce work
528 necessary for library list updating, resulting in significant
531 * New features in the GDB remote stub, GDBserver
533 ** GDBserver now supports target-assisted range stepping. Currently
534 enabled on x86/x86_64 GNU/Linux targets.
536 ** GDBserver now adds element 'tvar' in the XML in the reply to
537 'qXfer:traceframe-info:read'. It has the id of the collected
538 trace state variables.
540 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
543 * New 'z' formatter for printing and examining memory, this displays the
544 value as hexadecimal zero padded on the left to the size of the type.
546 * GDB can now use Windows x64 unwinding data.
548 * The "set remotebaud" command has been replaced by "set serial baud".
549 Similarly, "show remotebaud" has been replaced by "show serial baud".
550 The "set remotebaud" and "show remotebaud" commands are still available
551 to provide backward compatibility with older versions of GDB.
553 *** Changes in GDB 7.6
555 * Target record has been renamed to record-full.
556 Record/replay is now enabled with the "record full" command.
557 This also affects settings that are associated with full record/replay
558 that have been moved from "set/show record" to "set/show record full":
560 set|show record full insn-number-max
561 set|show record full stop-at-limit
562 set|show record full memory-query
564 * A new record target "record-btrace" has been added. The new target
565 uses hardware support to record the control-flow of a process. It
566 does not support replaying the execution, but it implements the
567 below new commands for investigating the recorded execution log.
568 This new recording method can be enabled using:
572 The "record-btrace" target is only available on Intel Atom processors
573 and requires a Linux kernel 2.6.32 or later.
575 * Two new commands have been added for record/replay to give information
576 about the recorded execution without having to replay the execution.
577 The commands are only supported by "record btrace".
579 record instruction-history prints the execution history at
580 instruction granularity
582 record function-call-history prints the execution history at
585 * New native configurations
587 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
588 FreeBSD/powerpc powerpc*-*-freebsd
589 x86_64/Cygwin x86_64-*-cygwin*
590 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
594 ARM AArch64 aarch64*-*-elf
595 ARM AArch64 GNU/Linux aarch64*-*-linux
596 Lynx 178 PowerPC powerpc-*-lynx*178
597 x86_64/Cygwin x86_64-*-cygwin*
598 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
600 * If the configured location of system.gdbinit file (as given by the
601 --with-system-gdbinit option at configure time) is in the
602 data-directory (as specified by --with-gdb-datadir at configure
603 time) or in one of its subdirectories, then GDB will look for the
604 system-wide init file in the directory specified by the
605 --data-directory command-line option.
607 * New command line options:
609 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
610 other initialization files, unlike -nx which disables all of them.
612 * Removed command line options
614 -epoch This was used by the gdb mode in Epoch, an ancient fork of
617 * The 'ptype' and 'whatis' commands now accept an argument to control
620 * 'info proc' now works on some core files.
624 ** Vectors can be created with gdb.Type.vector.
626 ** Python's atexit.register now works in GDB.
628 ** Types can be pretty-printed via a Python API.
630 ** Python 3 is now supported (in addition to Python 2.4 or later)
632 ** New class gdb.Architecture exposes GDB's internal representation
633 of architecture in the Python API.
635 ** New method Frame.architecture returns the gdb.Architecture object
636 corresponding to the frame's architecture.
638 * New Python-based convenience functions:
640 ** $_memeq(buf1, buf2, length)
641 ** $_streq(str1, str2)
643 ** $_regex(str, regex)
645 * The 'cd' command now defaults to using '~' (the home directory) if not
648 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
649 default for GCC since November 2000.
651 * The command 'forward-search' can now be abbreviated as 'fo'.
653 * The command 'info tracepoints' can now display 'installed on target'
654 or 'not installed on target' for each non-pending location of tracepoint.
656 * New configure options
658 --enable-libmcheck/--disable-libmcheck
659 By default, development versions are built with -lmcheck on hosts
660 that support it, in order to help track memory corruption issues.
661 Release versions, on the other hand, are built without -lmcheck
662 by default. The --enable-libmcheck/--disable-libmcheck configure
663 options allow the user to override that default.
664 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
665 This configure option allows the user to build GDB with
666 libbabeltrace using which GDB can read Common Trace Format data.
668 * New commands (for set/show, see "New options" below)
671 Catch signals. This is similar to "handle", but allows commands and
672 conditions to be attached.
675 List the BFDs known to GDB.
677 python-interactive [command]
679 Start a Python interactive prompt, or evaluate the optional command
680 and print the result of expressions.
683 "py" is a new alias for "python".
685 enable type-printer [name]...
686 disable type-printer [name]...
687 Enable or disable type printers.
691 ** For the Renesas Super-H architecture, the "regs" command has been removed
692 (has been deprecated in GDB 7.5), and "info all-registers" should be used
697 set print type methods (on|off)
698 show print type methods
699 Control whether method declarations are displayed by "ptype".
700 The default is to show them.
702 set print type typedefs (on|off)
703 show print type typedefs
704 Control whether typedef definitions are displayed by "ptype".
705 The default is to show them.
707 set filename-display basename|relative|absolute
708 show filename-display
709 Control the way in which filenames is displayed.
710 The default is "relative", which preserves previous behavior.
712 set trace-buffer-size
713 show trace-buffer-size
714 Request target to change the size of trace buffer.
716 set remote trace-buffer-size-packet auto|on|off
717 show remote trace-buffer-size-packet
718 Control the use of the remote protocol `QTBuffer:size' packet.
722 Control display of debugging messages related to ARM AArch64.
725 set debug coff-pe-read
726 show debug coff-pe-read
727 Control display of debugging messages related to reading of COFF/PE
732 Control display of debugging messages related to Mach-O symbols
735 set debug notification
736 show debug notification
737 Control display of debugging info for async remote notification.
741 ** Command parameter changes are now notified using new async record
742 "=cmd-param-changed".
743 ** Trace frame changes caused by command "tfind" are now notified using
744 new async record "=traceframe-changed".
745 ** The creation, deletion and modification of trace state variables
746 are now notified using new async records "=tsv-created",
747 "=tsv-deleted" and "=tsv-modified".
748 ** The start and stop of process record are now notified using new
749 async record "=record-started" and "=record-stopped".
750 ** Memory changes are now notified using new async record
752 ** The data-disassemble command response will include a "fullname" field
753 containing the absolute file name when source has been requested.
754 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
755 command, to allow pattern filling of memory areas.
756 ** New commands "-catch-load"/"-catch-unload" added for intercepting
757 library load/unload events.
758 ** The response to breakpoint commands and breakpoint async records
759 includes an "installed" field containing a boolean state about each
760 non-pending tracepoint location is whether installed on target or not.
761 ** Output of the "-trace-status" command includes a "trace-file" field
762 containing the name of the trace file being examined. This field is
763 optional, and only present when examining a trace file.
764 ** The "fullname" field is now always present along with the "file" field,
765 even if the file cannot be found by GDB.
767 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
768 You must have the LZMA library available when configuring GDB for this
769 feature to be enabled. For more information, see:
770 http://fedoraproject.org/wiki/Features/MiniDebugInfo
775 Set the size of trace buffer. The remote stub reports support for this
776 packet to gdb's qSupported query.
779 Enable Branch Trace Store (BTS)-based branch tracing for the current
780 thread. The remote stub reports support for this packet to gdb's
784 Disable branch tracing for the current thread. The remote stub reports
785 support for this packet to gdb's qSupported query.
788 Read the traced branches for the current thread. The remote stub
789 reports support for this packet to gdb's qSupported query.
791 *** Changes in GDB 7.5
793 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
794 for more x32 ABI info.
796 * GDB now supports access to MIPS DSP registers on Linux targets.
798 * GDB now supports debugging microMIPS binaries.
800 * The "info os" command on GNU/Linux can now display information on
801 several new classes of objects managed by the operating system:
802 "info os procgroups" lists process groups
803 "info os files" lists file descriptors
804 "info os sockets" lists internet-domain sockets
805 "info os shm" lists shared-memory regions
806 "info os semaphores" lists semaphores
807 "info os msg" lists message queues
808 "info os modules" lists loaded kernel modules
810 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
811 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
812 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
813 options and inspect the probe arguments using the new $_probe_arg family
814 of convenience variables. You can obtain more information about SystemTap
815 in <http://sourceware.org/systemtap/>.
817 * GDB now supports reversible debugging on ARM, it allows you to
818 debug basic ARM and THUMB instructions, and provides
819 record/replay support.
821 * The option "symbol-reloading" has been deleted as it is no longer used.
825 ** GDB commands implemented in Python can now be put in command class
828 ** The "maint set python print-stack on|off" is now deleted.
830 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
831 apply "flag enum"-style pretty-printing to any enum.
833 ** gdb.lookup_symbol can now work when there is no current frame.
835 ** gdb.Symbol now has a 'line' attribute, holding the line number in
836 the source at which the symbol was defined.
838 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
839 method 'value'. The former indicates whether the symbol needs a
840 frame in order to compute its value, and the latter computes the
843 ** A new method 'referenced_value' on gdb.Value objects which can
844 dereference pointer as well as C++ reference values.
846 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
847 which return the global and static blocks (as gdb.Block objects),
848 of the underlying symbol table, respectively.
850 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
851 object associated with a PC value.
853 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
854 of the address range occupied by code for the current source line.
856 * Go language support.
857 GDB now supports debugging programs written in the Go programming
860 * GDBserver now supports stdio connections.
861 E.g. (gdb) target remote | ssh myhost gdbserver - hello
863 * The binary "gdbtui" can no longer be built or installed.
864 Use "gdb -tui" instead.
866 * GDB will now print "flag" enums specially. A flag enum is one where
867 all the enumerator values have no bits in common when pairwise
868 "and"ed. When printing a value whose type is a flag enum, GDB will
869 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
870 (gdb) print (enum E) 3
873 * The filename part of a linespec will now match trailing components
874 of a source file name. For example, "break gcc/expr.c:1000" will
875 now set a breakpoint in build/gcc/expr.c, but not
878 * The "info proc" and "generate-core-file" commands will now also
879 work on remote targets connected to GDBserver on Linux.
881 * The command "info catch" has been removed. It has been disabled
884 * The "catch exception" and "catch assert" commands now accept
885 a condition at the end of the command, much like the "break"
886 command does. For instance:
888 (gdb) catch exception Constraint_Error if Barrier = True
890 Previously, it was possible to add a condition to such catchpoints,
891 but it had to be done as a second step, after the catchpoint had been
892 created, using the "condition" command.
894 * The "info static-tracepoint-marker" command will now also work on
895 native Linux targets with in-process agent.
897 * GDB can now set breakpoints on inlined functions.
899 * The .gdb_index section has been updated to include symbols for
900 inlined functions. GDB will ignore older .gdb_index sections by
901 default, which could cause symbol files to be loaded more slowly
902 until their .gdb_index sections can be recreated. The new command
903 "set use-deprecated-index-sections on" will cause GDB to use any older
904 .gdb_index sections it finds. This will restore performance, but the
905 ability to set breakpoints on inlined functions will be lost in symbol
906 files with older .gdb_index sections.
908 The .gdb_index section has also been updated to record more information
909 about each symbol. This speeds up the "info variables", "info functions"
910 and "info types" commands when used with programs having the .gdb_index
911 section, as well as speeding up debugging with shared libraries using
912 the .gdb_index section.
914 * Ada support for GDB/MI Variable Objects has been added.
916 * GDB can now support 'breakpoint always-inserted mode' in 'record'
921 ** New command -info-os is the MI equivalent of "info os".
923 ** Output logs ("set logging" and related) now include MI output.
927 ** "set use-deprecated-index-sections on|off"
928 "show use-deprecated-index-sections on|off"
929 Controls the use of deprecated .gdb_index sections.
931 ** "catch load" and "catch unload" can be used to stop when a shared
932 library is loaded or unloaded, respectively.
934 ** "enable count" can be used to auto-disable a breakpoint after
937 ** "info vtbl" can be used to show the virtual method tables for
938 C++ and Java objects.
940 ** "explore" and its sub commands "explore value" and "explore type"
941 can be used to recursively explore values and types of
942 expressions. These commands are available only if GDB is
943 configured with '--with-python'.
945 ** "info auto-load" shows status of all kinds of auto-loaded files,
946 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
947 sequences of commands files, "info auto-load python-scripts"
948 shows status of auto-loading Python script files,
949 "info auto-load local-gdbinit" shows status of loading init file
950 (.gdbinit) from current directory and "info auto-load libthread-db" shows
951 status of inferior specific thread debugging shared library loading.
953 ** "info auto-load-scripts", "set auto-load-scripts on|off"
954 and "show auto-load-scripts" commands have been deprecated, use their
955 "info auto-load python-scripts", "set auto-load python-scripts on|off"
956 and "show auto-load python-scripts" counterparts instead.
958 ** "dprintf location,format,args..." creates a dynamic printf, which
959 is basically a breakpoint that does a printf and immediately
960 resumes your program's execution, so it is like a printf that you
961 can insert dynamically at runtime instead of at compiletime.
963 ** "set print symbol"
965 Controls whether GDB attempts to display the symbol, if any,
966 corresponding to addresses it prints. This defaults to "on", but
967 you can set it to "off" to restore GDB's previous behavior.
969 * Deprecated commands
971 ** For the Renesas Super-H architecture, the "regs" command has been
972 deprecated, and "info all-registers" should be used instead.
976 Renesas RL78 rl78-*-elf
977 HP OpenVMS ia64 ia64-hp-openvms*
979 * GDBserver supports evaluation of breakpoint conditions. When
980 support is advertised by GDBserver, GDB may be told to send the
981 breakpoint conditions in bytecode form to GDBserver. GDBserver
982 will only report the breakpoint trigger to GDB when its condition
988 show mips compression
989 Select the compressed ISA encoding used in functions that have no symbol
990 information available. The encoding can be set to either of:
993 and is updated automatically from ELF file flags if available.
995 set breakpoint condition-evaluation
996 show breakpoint condition-evaluation
997 Control whether breakpoint conditions are evaluated by GDB ("host") or by
998 GDBserver ("target"). Default option "auto" chooses the most efficient
1000 This option can improve debugger efficiency depending on the speed of the
1004 Disable auto-loading globally.
1007 Show auto-loading setting of all kinds of auto-loaded files.
1009 set auto-load gdb-scripts on|off
1010 show auto-load gdb-scripts
1011 Control auto-loading of GDB canned sequences of commands files.
1013 set auto-load python-scripts on|off
1014 show auto-load python-scripts
1015 Control auto-loading of Python script files.
1017 set auto-load local-gdbinit on|off
1018 show auto-load local-gdbinit
1019 Control loading of init file (.gdbinit) from current directory.
1021 set auto-load libthread-db on|off
1022 show auto-load libthread-db
1023 Control auto-loading of inferior specific thread debugging shared library.
1025 set auto-load scripts-directory <dir1>[:<dir2>...]
1026 show auto-load scripts-directory
1027 Set a list of directories from which to load auto-loaded scripts.
1028 Automatically loaded Python scripts and GDB scripts are located in one
1029 of the directories listed by this option.
1030 The delimiter (':' above) may differ according to the host platform.
1032 set auto-load safe-path <dir1>[:<dir2>...]
1033 show auto-load safe-path
1034 Set a list of directories from which it is safe to auto-load files.
1035 The delimiter (':' above) may differ according to the host platform.
1037 set debug auto-load on|off
1038 show debug auto-load
1039 Control display of debugging info for auto-loading the files above.
1041 set dprintf-style gdb|call|agent
1043 Control the way in which a dynamic printf is performed; "gdb"
1044 requests a GDB printf command, while "call" causes dprintf to call a
1045 function in the inferior. "agent" requests that the target agent
1046 (such as GDBserver) do the printing.
1048 set dprintf-function <expr>
1049 show dprintf-function
1050 set dprintf-channel <expr>
1051 show dprintf-channel
1052 Set the function and optional first argument to the call when using
1053 the "call" style of dynamic printf.
1055 set disconnected-dprintf on|off
1056 show disconnected-dprintf
1057 Control whether agent-style dynamic printfs continue to be in effect
1058 after GDB disconnects.
1060 * New configure options
1062 --with-auto-load-dir
1063 Configure default value for the 'set auto-load scripts-directory'
1064 setting above. It defaults to '$debugdir:$datadir/auto-load',
1065 $debugdir representing global debugging info directories (available
1066 via 'show debug-file-directory') and $datadir representing GDB's data
1067 directory (available via 'show data-directory').
1069 --with-auto-load-safe-path
1070 Configure default value for the 'set auto-load safe-path' setting
1071 above. It defaults to the --with-auto-load-dir setting.
1073 --without-auto-load-safe-path
1074 Set 'set auto-load safe-path' to '/', effectively disabling this
1077 * New remote packets
1079 z0/z1 conditional breakpoints extension
1081 The z0/z1 breakpoint insertion packets have been extended to carry
1082 a list of conditional expressions over to the remote stub depending on the
1083 condition evaluation mode. The use of this extension can be controlled
1084 via the "set remote conditional-breakpoints-packet" command.
1088 Specify the signals which the remote stub may pass to the debugged
1089 program without GDB involvement.
1091 * New command line options
1093 --init-command=FILE, -ix Like --command, -x but execute it
1094 before loading inferior.
1095 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1096 execute it before loading inferior.
1098 *** Changes in GDB 7.4
1100 * GDB now handles ambiguous linespecs more consistently; the existing
1101 FILE:LINE support has been expanded to other types of linespecs. A
1102 breakpoint will now be set on all matching locations in all
1103 inferiors, and locations will be added or removed according to
1106 * GDB now allows you to skip uninteresting functions and files when
1107 stepping with the "skip function" and "skip file" commands.
1109 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1110 and "show remote hardware-watchpoint-length-limit". These allows to
1111 set or show the maximum length limit (in bytes) of a remote
1112 target hardware watchpoint.
1114 This allows e.g. to use "unlimited" hardware watchpoints with the
1115 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1116 watchpoints are slower than real hardware watchpoints but are
1117 significantly faster than gdb software watchpoints.
1121 ** The register_pretty_printer function in module gdb.printing now takes
1122 an optional `replace' argument. If True, the new printer replaces any
1125 ** The "maint set python print-stack on|off" command has been
1126 deprecated and will be deleted in GDB 7.5.
1127 A new command: "set python print-stack none|full|message" has
1128 replaced it. Additionally, the default for "print-stack" is
1129 now "message", which just prints the error message without
1132 ** A prompt substitution hook (prompt_hook) is now available to the
1135 ** A new Python module, gdb.prompt has been added to the GDB Python
1136 modules library. This module provides functionality for
1137 escape sequences in prompts (used by set/show
1138 extended-prompt). These escape sequences are replaced by their
1139 corresponding value.
1141 ** Python commands and convenience-functions located in
1142 'data-directory'/python/gdb/command and
1143 'data-directory'/python/gdb/function are now automatically loaded
1146 ** Blocks now provide four new attributes. global_block and
1147 static_block will return the global and static blocks
1148 respectively. is_static and is_global are boolean attributes
1149 that indicate if the block is one of those two types.
1151 ** Symbols now provide the "type" attribute, the type of the symbol.
1153 ** The "gdb.breakpoint" function has been deprecated in favor of
1156 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1157 of a function. This class is based on the "finish" command
1158 available in the CLI.
1160 ** Type objects for struct and union types now allow access to
1161 the fields using standard Python dictionary (mapping) methods.
1162 For example, "some_type['myfield']" now works, as does
1163 "some_type.items()".
1165 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1168 ** A new function, "deep_items" has been added to the gdb.types
1169 module in the GDB Python modules library. This function returns
1170 an iterator over the fields of a struct or union type. Unlike
1171 the standard Python "iteritems" method, it will recursively traverse
1172 any anonymous fields.
1176 ** "*stopped" events can report several new "reason"s, such as
1179 ** Breakpoint changes are now notified using new async records, like
1180 "=breakpoint-modified".
1182 ** New command -ada-task-info.
1184 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1185 $sdir specifies the default system locations of shared libraries.
1186 $pdir specifies the directory where the libpthread used by the application
1189 GDB no longer looks in $sdir and $pdir after it has searched the directories
1190 mentioned in libthread-db-search-path. If you want to search those
1191 directories, they must be specified in libthread-db-search-path.
1192 The default value of libthread-db-search-path on GNU/Linux and Solaris
1193 systems is now "$sdir:$pdir".
1195 $pdir is not supported by gdbserver, it is currently ignored.
1196 $sdir is supported by gdbserver.
1198 * New configure option --with-iconv-bin.
1199 When using the internationalization support like the one in the GNU C
1200 library, GDB will invoke the "iconv" program to get a list of supported
1201 character sets. If this program lives in a non-standard location, one can
1202 use this option to specify where to find it.
1204 * When natively debugging programs on PowerPC BookE processors running
1205 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1206 watchpoints, which specify a mask in addition to an address to watch.
1207 The mask specifies that some bits of an address (the bits which are
1208 reset in the mask) should be ignored when matching the address accessed
1209 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1210 section in the user manual for more details.
1212 * The new option --once causes GDBserver to stop listening for connections once
1213 the first connection is made. The listening port used by GDBserver will
1214 become available after that.
1216 * New commands "info macros" and "alias" have been added.
1218 * New function parameters suffix @entry specifies value of function parameter
1219 at the time the function got called. Entry values are available only since
1225 "!" is now an alias of the "shell" command.
1226 Note that no space is needed between "!" and SHELL COMMAND.
1230 watch EXPRESSION mask MASK_VALUE
1231 The watch command now supports the mask argument which allows creation
1232 of masked watchpoints, if the current architecture supports this feature.
1234 info auto-load-scripts [REGEXP]
1235 This command was formerly named "maintenance print section-scripts".
1236 It is now generally useful and is no longer a maintenance-only command.
1238 info macro [-all] [--] MACRO
1239 The info macro command has new options `-all' and `--'. The first for
1240 printing all definitions of a macro. The second for explicitly specifying
1241 the end of arguments and the beginning of the macro name in case the macro
1242 name starts with a hyphen.
1244 collect[/s] EXPRESSIONS
1245 The tracepoint collect command now takes an optional modifier "/s"
1246 that directs it to dereference pointer-to-character types and
1247 collect the bytes of memory up to a zero byte. The behavior is
1248 similar to what you see when you use the regular print command on a
1249 string. An optional integer following the "/s" sets a bound on the
1250 number of bytes that will be collected.
1253 The trace start command now interprets any supplied arguments as a
1254 note to be recorded with the trace run, with an effect similar to
1255 setting the variable trace-notes.
1258 The trace stop command now interprets any arguments as a note to be
1259 mentioned along with the tstatus report that the trace was stopped
1260 with a command. The effect is similar to setting the variable
1263 * Tracepoints can now be enabled and disabled at any time after a trace
1264 experiment has been started using the standard "enable" and "disable"
1265 commands. It is now possible to start a trace experiment with no enabled
1266 tracepoints; GDB will display a warning, but will allow the experiment to
1267 begin, assuming that tracepoints will be enabled as needed while the trace
1270 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1271 locations with 4-byte instructions, when they were previously
1272 limited to locations with instructions of 5 bytes or longer.
1276 set debug dwarf2-read
1277 show debug dwarf2-read
1278 Turns on or off display of debugging messages related to reading
1279 DWARF debug info. The default is off.
1281 set debug symtab-create
1282 show debug symtab-create
1283 Turns on or off display of debugging messages related to symbol table
1284 creation. The default is off.
1287 show extended-prompt
1288 Set the GDB prompt, and allow escape sequences to be inserted to
1289 display miscellaneous information (see 'help set extended-prompt'
1290 for the list of sequences). This prompt (and any information
1291 accessed through the escape sequences) is updated every time the
1292 prompt is displayed.
1294 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1295 show print entry-values
1296 Set printing of frame argument values at function entry. In some cases
1297 GDB can determine the value of function argument which was passed by the
1298 function caller, even if the value was modified inside the called function.
1300 set debug entry-values
1301 show debug entry-values
1302 Control display of debugging info for determining frame argument values at
1303 function entry and virtual tail call frames.
1305 set basenames-may-differ
1306 show basenames-may-differ
1307 Set whether a source file may have multiple base names.
1308 (A "base name" is the name of a file with the directory part removed.
1309 Example: The base name of "/home/user/hello.c" is "hello.c".)
1310 If set, GDB will canonicalize file names (e.g., expand symlinks)
1311 before comparing them. Canonicalization is an expensive operation,
1312 but it allows the same file be known by more than one base name.
1313 If not set (the default), all source files are assumed to have just
1314 one base name, and gdb will do file name comparisons more efficiently.
1320 Set a user name and notes for the current and any future trace runs.
1321 This is useful for long-running and/or disconnected traces, to
1322 inform others (or yourself) as to who is running the trace, supply
1323 contact information, or otherwise explain what is going on.
1325 set trace-stop-notes
1326 show trace-stop-notes
1327 Set a note attached to the trace run, that is displayed when the
1328 trace has been stopped by a tstop command. This is useful for
1329 instance as an explanation, if you are stopping a trace run that was
1330 started by someone else.
1332 * New remote packets
1336 Dynamically enable a tracepoint in a started trace experiment.
1340 Dynamically disable a tracepoint in a started trace experiment.
1344 Set the user and notes of the trace run.
1348 Query the current status of a tracepoint.
1352 Query the minimum length of instruction at which a fast tracepoint may
1355 * Dcache size (number of lines) and line-size are now runtime-configurable
1356 via "set dcache line" and "set dcache line-size" commands.
1360 Texas Instruments TMS320C6x tic6x-*-*
1364 Renesas RL78 rl78-*-elf
1366 *** Changes in GDB 7.3.1
1368 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1370 *** Changes in GDB 7.3
1372 * GDB has a new command: "thread find [REGEXP]".
1373 It finds the thread id whose name, target id, or thread extra info
1374 matches the given regular expression.
1376 * The "catch syscall" command now works on mips*-linux* targets.
1378 * The -data-disassemble MI command now supports modes 2 and 3 for
1379 dumping the instruction opcodes.
1381 * New command line options
1383 -data-directory DIR Specify DIR as the "data-directory".
1384 This is mostly for testing purposes.
1386 * The "maint set python auto-load on|off" command has been renamed to
1387 "set auto-load-scripts on|off".
1389 * GDB has a new command: "set directories".
1390 It is like the "dir" command except that it replaces the
1391 source path list instead of augmenting it.
1393 * GDB now understands thread names.
1395 On GNU/Linux, "info threads" will display the thread name as set by
1396 prctl or pthread_setname_np.
1398 There is also a new command, "thread name", which can be used to
1399 assign a name internally for GDB to display.
1402 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1403 has been integrated into GDB.
1407 ** The function gdb.Write now accepts an optional keyword 'stream'.
1408 This keyword, when provided, will direct the output to either
1409 stdout, stderr, or GDB's logging output.
1411 ** Parameters can now be be sub-classed in Python, and in particular
1412 you may implement the get_set_doc and get_show_doc functions.
1413 This improves how Parameter set/show documentation is processed
1414 and allows for more dynamic content.
1416 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1417 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1418 have an is_valid method.
1420 ** Breakpoints can now be sub-classed in Python, and in particular
1421 you may implement a 'stop' function that is executed each time
1422 the inferior reaches that breakpoint.
1424 ** New function gdb.lookup_global_symbol looks up a global symbol.
1426 ** GDB values in Python are now callable if the value represents a
1427 function. For example, if 'some_value' represents a function that
1428 takes two integer parameters and returns a value, you can call
1429 that function like so:
1431 result = some_value (10,20)
1433 ** Module gdb.types has been added.
1434 It contains a collection of utilities for working with gdb.Types objects:
1435 get_basic_type, has_field, make_enum_dict.
1437 ** Module gdb.printing has been added.
1438 It contains utilities for writing and registering pretty-printers.
1439 New classes: PrettyPrinter, SubPrettyPrinter,
1440 RegexpCollectionPrettyPrinter.
1441 New function: register_pretty_printer.
1443 ** New commands "info pretty-printers", "enable pretty-printer" and
1444 "disable pretty-printer" have been added.
1446 ** gdb.parameter("directories") is now available.
1448 ** New function gdb.newest_frame returns the newest frame in the
1451 ** The gdb.InferiorThread class has a new "name" attribute. This
1452 holds the thread's name.
1454 ** Python Support for Inferior events.
1455 Python scripts can add observers to be notified of events
1456 occurring in the process being debugged.
1457 The following events are currently supported:
1458 - gdb.events.cont Continue event.
1459 - gdb.events.exited Inferior exited event.
1460 - gdb.events.stop Signal received, and Breakpoint hit events.
1464 ** GDB now puts template parameters in scope when debugging in an
1465 instantiation. For example, if you have:
1467 template<int X> int func (void) { return X; }
1469 then if you step into func<5>, "print X" will show "5". This
1470 feature requires proper debuginfo support from the compiler; it
1471 was added to GCC 4.5.
1473 ** The motion commands "next", "finish", "until", and "advance" now
1474 work better when exceptions are thrown. In particular, GDB will
1475 no longer lose control of the inferior; instead, the GDB will
1476 stop the inferior at the point at which the exception is caught.
1477 This functionality requires a change in the exception handling
1478 code that was introduced in GCC 4.5.
1480 * GDB now follows GCC's rules on accessing volatile objects when
1481 reading or writing target state during expression evaluation.
1482 One notable difference to prior behavior is that "print x = 0"
1483 no longer generates a read of x; the value of the assignment is
1484 now always taken directly from the value being assigned.
1486 * GDB now has some support for using labels in the program's source in
1487 linespecs. For instance, you can use "advance label" to continue
1488 execution to a label.
1490 * GDB now has support for reading and writing a new .gdb_index
1491 section. This section holds a fast index of DWARF debugging
1492 information and can be used to greatly speed up GDB startup and
1493 operation. See the documentation for `save gdb-index' for details.
1495 * The "watch" command now accepts an optional "-location" argument.
1496 When used, this causes GDB to watch the memory referred to by the
1497 expression. Such a watchpoint is never deleted due to it going out
1500 * GDB now supports thread debugging of core dumps on GNU/Linux.
1502 GDB now activates thread debugging using the libthread_db library
1503 when debugging GNU/Linux core dumps, similarly to when debugging
1504 live processes. As a result, when debugging a core dump file, GDB
1505 is now able to display pthread_t ids of threads. For example, "info
1506 threads" shows the same output as when debugging the process when it
1507 was live. In earlier releases, you'd see something like this:
1510 * 1 LWP 6780 main () at main.c:10
1512 While now you see this:
1515 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1517 It is also now possible to inspect TLS variables when debugging core
1520 When debugging a core dump generated on a machine other than the one
1521 used to run GDB, you may need to point GDB at the correct
1522 libthread_db library with the "set libthread-db-search-path"
1523 command. See the user manual for more details on this command.
1525 * When natively debugging programs on PowerPC BookE processors running
1526 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1527 which stop execution of the inferior whenever it executes an instruction
1528 at any address within the specified range. See the "PowerPC Embedded"
1529 section in the user manual for more details.
1531 * New features in the GDB remote stub, GDBserver
1533 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1534 and i686 LynxOS (version 5.x).
1536 ** GDBserver is now supported on Blackfin Linux.
1538 * New native configurations
1540 ia64 HP-UX ia64-*-hpux*
1544 Analog Devices, Inc. Blackfin Processor bfin-*
1546 * Ada task switching is now supported on sparc-elf targets when
1547 debugging a program using the Ravenscar Profile. For more information,
1548 see the "Tasking Support when using the Ravenscar Profile" section
1549 in the GDB user manual.
1551 * Guile support was removed.
1553 * New features in the GNU simulator
1555 ** The --map-info flag lists all known core mappings.
1557 ** CFI flashes may be simulated via the "cfi" device.
1559 *** Changes in GDB 7.2
1561 * Shared library support for remote targets by default
1563 When GDB is configured for a generic, non-OS specific target, like
1564 for example, --target=arm-eabi or one of the many *-*-elf targets,
1565 GDB now queries remote stubs for loaded shared libraries using the
1566 `qXfer:libraries:read' packet. Previously, shared library support
1567 was always disabled for such configurations.
1571 ** Argument Dependent Lookup (ADL)
1573 In C++ ADL lookup directs function search to the namespaces of its
1574 arguments even if the namespace has not been imported.
1584 Here the compiler will search for `foo' in the namespace of 'b'
1585 and find A::foo. GDB now supports this. This construct is commonly
1586 used in the Standard Template Library for operators.
1588 ** Improved User Defined Operator Support
1590 In addition to member operators, GDB now supports lookup of operators
1591 defined in a namespace and imported with a `using' directive, operators
1592 defined in the global scope, operators imported implicitly from an
1593 anonymous namespace, and the ADL operators mentioned in the previous
1595 GDB now also supports proper overload resolution for all the previously
1596 mentioned flavors of operators.
1598 ** static const class members
1600 Printing of static const class members that are initialized in the
1601 class definition has been fixed.
1603 * Windows Thread Information Block access.
1605 On Windows targets, GDB now supports displaying the Windows Thread
1606 Information Block (TIB) structure. This structure is visible either
1607 by using the new command `info w32 thread-information-block' or, by
1608 dereferencing the new convenience variable named `$_tlb', a
1609 thread-specific pointer to the TIB. This feature is also supported
1610 when remote debugging using GDBserver.
1612 * Static tracepoints
1614 Static tracepoints are calls in the user program into a tracing
1615 library. One such library is a port of the LTTng kernel tracer to
1616 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1617 When debugging with GDBserver, GDB now supports combining the GDB
1618 tracepoint machinery with such libraries. For example: the user can
1619 use GDB to probe a static tracepoint marker (a call from the user
1620 program into the tracing library) with the new "strace" command (see
1621 "New commands" below). This creates a "static tracepoint" in the
1622 breakpoint list, that can be manipulated with the same feature set
1623 as fast and regular tracepoints. E.g., collect registers, local and
1624 global variables, collect trace state variables, and define
1625 tracepoint conditions. In addition, the user can collect extra
1626 static tracepoint marker specific data, by collecting the new
1627 $_sdata internal variable. When analyzing the trace buffer, you can
1628 inspect $_sdata like any other variable available to GDB. For more
1629 information, see the "Tracepoints" chapter in GDB user manual. New
1630 remote packets have been defined to support static tracepoints, see
1631 the "New remote packets" section below.
1633 * Better reconstruction of tracepoints after disconnected tracing
1635 GDB will attempt to download the original source form of tracepoint
1636 definitions when starting a trace run, and then will upload these
1637 upon reconnection to the target, resulting in a more accurate
1638 reconstruction of the tracepoints that are in use on the target.
1642 You can now exercise direct control over the ways that GDB can
1643 affect your program. For instance, you can disallow the setting of
1644 breakpoints, so that the program can run continuously (assuming
1645 non-stop mode). In addition, the "observer" variable is available
1646 to switch all of the different controls; in observer mode, GDB
1647 cannot affect the target's behavior at all, which is useful for
1648 tasks like diagnosing live systems in the field.
1650 * The new convenience variable $_thread holds the number of the
1653 * New remote packets
1657 Return the address of the Windows Thread Information Block of a given thread.
1661 In response to several of the tracepoint packets, the target may now
1662 also respond with a number of intermediate `qRelocInsn' request
1663 packets before the final result packet, to have GDB handle
1664 relocating an instruction to execute at a different address. This
1665 is particularly useful for stubs that support fast tracepoints. GDB
1666 reports support for this feature in the qSupported packet.
1670 List static tracepoint markers in the target program.
1674 List static tracepoint markers at a given address in the target
1677 qXfer:statictrace:read
1679 Read the static trace data collected (by a `collect $_sdata'
1680 tracepoint action). The remote stub reports support for this packet
1681 to gdb's qSupported query.
1685 Send the current settings of GDB's permission flags.
1689 Send part of the source (textual) form of a tracepoint definition,
1690 which includes location, conditional, and action list.
1692 * The source command now accepts a -s option to force searching for the
1693 script in the source search path even if the script name specifies
1696 * New features in the GDB remote stub, GDBserver
1698 - GDBserver now support tracepoints (including fast tracepoints, and
1699 static tracepoints). The feature is currently supported by the
1700 i386-linux and amd64-linux builds. See the "Tracepoints support
1701 in gdbserver" section in the manual for more information.
1703 GDBserver JIT compiles the tracepoint's conditional agent
1704 expression bytecode into native code whenever possible for low
1705 overhead dynamic tracepoints conditionals. For such tracepoints,
1706 an expression that examines program state is evaluated when the
1707 tracepoint is reached, in order to determine whether to capture
1708 trace data. If the condition is simple and false, processing the
1709 tracepoint finishes very quickly and no data is gathered.
1711 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1712 for static tracepoints support.
1714 - GDBserver now supports x86_64 Windows 64-bit debugging.
1716 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1717 it understands register description.
1719 * The --batch flag now disables pagination and queries.
1721 * X86 general purpose registers
1723 GDB now supports reading/writing byte, word and double-word x86
1724 general purpose registers directly. This means you can use, say,
1725 $ah or $ax to refer, respectively, to the byte register AH and
1726 16-bit word register AX that are actually portions of the 32-bit
1727 register EAX or 64-bit register RAX.
1729 * The `commands' command now accepts a range of breakpoints to modify.
1730 A plain `commands' following a command that creates multiple
1731 breakpoints affects all the breakpoints set by that command. This
1732 applies to breakpoints set by `rbreak', and also applies when a
1733 single `break' command creates multiple breakpoints (e.g.,
1734 breakpoints on overloaded c++ functions).
1736 * The `rbreak' command now accepts a filename specification as part of
1737 its argument, limiting the functions selected by the regex to those
1738 in the specified file.
1740 * Support for remote debugging Windows and SymbianOS shared libraries
1741 from Unix hosts has been improved. Non Windows GDB builds now can
1742 understand target reported file names that follow MS-DOS based file
1743 system semantics, such as file names that include drive letters and
1744 use the backslash character as directory separator. This makes it
1745 possible to transparently use the "set sysroot" and "set
1746 solib-search-path" on Unix hosts to point as host copies of the
1747 target's shared libraries. See the new command "set
1748 target-file-system-kind" described below, and the "Commands to
1749 specify files" section in the user manual for more information.
1753 eval template, expressions...
1754 Convert the values of one or more expressions under the control
1755 of the string template to a command line, and call it.
1757 set target-file-system-kind unix|dos-based|auto
1758 show target-file-system-kind
1759 Set or show the assumed file system kind for target reported file
1762 save breakpoints <filename>
1763 Save all current breakpoint definitions to a file suitable for use
1764 in a later debugging session. To read the saved breakpoint
1765 definitions, use the `source' command.
1767 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1770 info static-tracepoint-markers
1771 Display information about static tracepoint markers in the target.
1773 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1774 Define a static tracepoint by probing a marker at the given
1775 function, line, address, or marker ID.
1779 Enable and disable observer mode.
1781 set may-write-registers on|off
1782 set may-write-memory on|off
1783 set may-insert-breakpoints on|off
1784 set may-insert-tracepoints on|off
1785 set may-insert-fast-tracepoints on|off
1786 set may-interrupt on|off
1787 Set individual permissions for GDB effects on the target. Note that
1788 some of these settings can have undesirable or surprising
1789 consequences, particularly when changed in the middle of a session.
1790 For instance, disabling the writing of memory can prevent
1791 breakpoints from being inserted, cause single-stepping to fail, or
1792 even crash your program, if you disable after breakpoints have been
1793 inserted. However, GDB should not crash.
1795 set record memory-query on|off
1796 show record memory-query
1797 Control whether to stop the inferior if memory changes caused
1798 by an instruction cannot be recorded.
1803 The disassemble command now supports "start,+length" form of two arguments.
1807 ** GDB now provides a new directory location, called the python directory,
1808 where Python scripts written for GDB can be installed. The location
1809 of that directory is <data-directory>/python, where <data-directory>
1810 is the GDB data directory. For more details, see section `Scripting
1811 GDB using Python' in the manual.
1813 ** The GDB Python API now has access to breakpoints, symbols, symbol
1814 tables, program spaces, inferiors, threads and frame's code blocks.
1815 Additionally, GDB Parameters can now be created from the API, and
1816 manipulated via set/show in the CLI.
1818 ** New functions gdb.target_charset, gdb.target_wide_charset,
1819 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1821 ** New exception gdb.GdbError.
1823 ** Pretty-printers are now also looked up in the current program space.
1825 ** Pretty-printers can now be individually enabled and disabled.
1827 ** GDB now looks for names of Python scripts to auto-load in a
1828 special section named `.debug_gdb_scripts', in addition to looking
1829 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1831 * Tracepoint actions were unified with breakpoint commands. In particular,
1832 there are no longer differences in "info break" output for breakpoints and
1833 tracepoints and the "commands" command can be used for both tracepoints and
1834 regular breakpoints.
1838 ARM Symbian arm*-*-symbianelf*
1840 * D language support.
1841 GDB now supports debugging programs written in the D programming
1844 * GDB now supports the extended ptrace interface for PowerPC which is
1845 available since Linux kernel version 2.6.34. This automatically enables
1846 any hardware breakpoints and additional hardware watchpoints available in
1847 the processor. The old ptrace interface exposes just one hardware
1848 watchpoint and no hardware breakpoints.
1850 * GDB is now able to use the Data Value Compare (DVC) register available on
1851 embedded PowerPC processors to implement in hardware simple watchpoint
1852 conditions of the form:
1854 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1856 This works in native GDB running on Linux kernels with the extended ptrace
1857 interface mentioned above.
1859 *** Changes in GDB 7.1
1863 ** Namespace Support
1865 GDB now supports importing of namespaces in C++. This enables the
1866 user to inspect variables from imported namespaces. Support for
1867 namepace aliasing has also been added. So, if a namespace is
1868 aliased in the current scope (e.g. namepace C=A; ) the user can
1869 print variables using the alias (e.g. (gdb) print C::x).
1873 All known bugs relating to the printing of virtual base class were
1874 fixed. It is now possible to call overloaded static methods using a
1879 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1880 and reinterpret_cast<> are now handled by the C++ expression parser.
1884 Xilinx MicroBlaze microblaze-*-*
1889 Xilinx MicroBlaze microblaze
1892 * Multi-program debugging.
1894 GDB now has support for multi-program (a.k.a. multi-executable or
1895 multi-exec) debugging. This allows for debugging multiple inferiors
1896 simultaneously each running a different program under the same GDB
1897 session. See "Debugging Multiple Inferiors and Programs" in the
1898 manual for more information. This implied some user visible changes
1899 in the multi-inferior support. For example, "info inferiors" now
1900 lists inferiors that are not running yet or that have exited
1901 already. See also "New commands" and "New options" below.
1903 * New tracing features
1905 GDB's tracepoint facility now includes several new features:
1907 ** Trace state variables
1909 GDB tracepoints now include support for trace state variables, which
1910 are variables managed by the target agent during a tracing
1911 experiment. They are useful for tracepoints that trigger each
1912 other, so for instance one tracepoint can count hits in a variable,
1913 and then a second tracepoint has a condition that is true when the
1914 count reaches a particular value. Trace state variables share the
1915 $-syntax of GDB convenience variables, and can appear in both
1916 tracepoint actions and condition expressions. Use the "tvariable"
1917 command to create, and "info tvariables" to view; see "Trace State
1918 Variables" in the manual for more detail.
1922 GDB now includes an option for defining fast tracepoints, which
1923 targets may implement more efficiently, such as by installing a jump
1924 into the target agent rather than a trap instruction. The resulting
1925 speedup can be by two orders of magnitude or more, although the
1926 tradeoff is that some program locations on some target architectures
1927 might not allow fast tracepoint installation, for instance if the
1928 instruction to be replaced is shorter than the jump. To request a
1929 fast tracepoint, use the "ftrace" command, with syntax identical to
1930 the regular trace command.
1932 ** Disconnected tracing
1934 It is now possible to detach GDB from the target while it is running
1935 a trace experiment, then reconnect later to see how the experiment
1936 is going. In addition, a new variable disconnected-tracing lets you
1937 tell the target agent whether to continue running a trace if the
1938 connection is lost unexpectedly.
1942 GDB now has the ability to save the trace buffer into a file, and
1943 then use that file as a target, similarly to you can do with
1944 corefiles. You can select trace frames, print data that was
1945 collected in them, and use tstatus to display the state of the
1946 tracing run at the moment that it was saved. To create a trace
1947 file, use "tsave <filename>", and to use it, do "target tfile
1950 ** Circular trace buffer
1952 You can ask the target agent to handle the trace buffer as a
1953 circular buffer, discarding the oldest trace frames to make room for
1954 newer ones, by setting circular-trace-buffer to on. This feature may
1955 not be available for all target agents.
1960 The disassemble command, when invoked with two arguments, now requires
1961 the arguments to be comma-separated.
1964 The info variables command now displays variable definitions. Files
1965 which only declare a variable are not shown.
1968 The source command is now capable of sourcing Python scripts.
1969 This feature is dependent on the debugger being build with Python
1972 Related to this enhancement is also the introduction of a new command
1973 "set script-extension" (see below).
1975 * New commands (for set/show, see "New options" below)
1977 record save [<FILENAME>]
1978 Save a file (in core file format) containing the process record
1979 execution log for replay debugging at a later time.
1981 record restore <FILENAME>
1982 Restore the process record execution log that was saved at an
1983 earlier time, for replay debugging.
1985 add-inferior [-copies <N>] [-exec <FILENAME>]
1988 clone-inferior [-copies <N>] [ID]
1989 Make a new inferior ready to execute the same program another
1990 inferior has loaded.
1995 maint info program-spaces
1996 List the program spaces loaded into GDB.
1998 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1999 show remote interrupt-sequence
2000 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2001 as the sequence to the remote target in order to interrupt the execution.
2002 Ctrl-C is a default. Some system prefers BREAK which is high level of
2003 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2004 Magic SysRq g. It is BREAK signal and character 'g'.
2006 set remote interrupt-on-connect [on | off]
2007 show remote interrupt-on-connect
2008 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2009 remote target when gdb connects to it. This is needed when you debug
2012 set remotebreak [on | off]
2014 Deprecated. Use "set/show remote interrupt-sequence" instead.
2016 tvariable $NAME [ = EXP ]
2017 Create or modify a trace state variable.
2020 List trace state variables and their values.
2022 delete tvariable $NAME ...
2023 Delete one or more trace state variables.
2026 Evaluate the given expressions without collecting anything into the
2027 trace buffer. (Valid in tracepoint actions only.)
2029 ftrace FN / FILE:LINE / *ADDR
2030 Define a fast tracepoint at the given function, line, or address.
2032 * New expression syntax
2034 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2035 GDB now parses 0b101010 identically with 42.
2039 set follow-exec-mode new|same
2040 show follow-exec-mode
2041 Control whether GDB reuses the same inferior across an exec call or
2042 creates a new one. This is useful to be able to restart the old
2043 executable after the inferior having done an exec call.
2045 set default-collect EXPR, ...
2046 show default-collect
2047 Define a list of expressions to be collected at each tracepoint.
2048 This is a useful way to ensure essential items are not overlooked,
2049 such as registers or a critical global variable.
2051 set disconnected-tracing
2052 show disconnected-tracing
2053 If set to 1, the target is instructed to continue tracing if it
2054 loses its connection to GDB. If 0, the target is to stop tracing
2057 set circular-trace-buffer
2058 show circular-trace-buffer
2059 If set to on, the target is instructed to use a circular trace buffer
2060 and discard the oldest trace frames instead of stopping the trace due
2061 to a full trace buffer. If set to off, the trace stops when the buffer
2062 fills up. Some targets may not support this.
2064 set script-extension off|soft|strict
2065 show script-extension
2066 If set to "off", the debugger does not perform any script language
2067 recognition, and all sourced files are assumed to be GDB scripts.
2068 If set to "soft" (the default), files are sourced according to
2069 filename extension, falling back to GDB scripts if the first
2071 If set to "strict", files are sourced according to filename extension.
2073 set ada trust-PAD-over-XVS on|off
2074 show ada trust-PAD-over-XVS
2075 If off, activate a workaround against a bug in the debugging information
2076 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2077 the GCC sources for more information about the GNAT encoding and
2078 PAD types in particular). It is always safe to set this option to
2079 off, but this introduces a slight performance penalty. The default
2082 * Python API Improvements
2084 ** GDB provides the new class gdb.LazyString. This is useful in
2085 some pretty-printing cases. The new method gdb.Value.lazy_string
2086 provides a simple way to create objects of this type.
2088 ** The fields returned by gdb.Type.fields now have an
2089 `is_base_class' attribute.
2091 ** The new method gdb.Type.range returns the range of an array type.
2093 ** The new method gdb.parse_and_eval can be used to parse and
2094 evaluate an expression.
2096 * New remote packets
2099 Define a trace state variable.
2102 Get the current value of a trace state variable.
2105 Set desired tracing behavior upon disconnection.
2108 Set the trace buffer to be linear or circular.
2111 Get data about the tracepoints currently in use.
2115 Process record now works correctly with hardware watchpoints.
2117 Multiple bug fixes have been made to the mips-irix port, making it
2118 much more reliable. In particular:
2119 - Debugging threaded applications is now possible again. Previously,
2120 GDB would hang while starting the program, or while waiting for
2121 the program to stop at a breakpoint.
2122 - Attaching to a running process no longer hangs.
2123 - An error occurring while loading a core file has been fixed.
2124 - Changing the value of the PC register now works again. This fixes
2125 problems observed when using the "jump" command, or when calling
2126 a function from GDB, or even when assigning a new value to $pc.
2127 - With the "finish" and "return" commands, the return value for functions
2128 returning a small array is now correctly printed.
2129 - It is now possible to break on shared library code which gets executed
2130 during a shared library init phase (code executed while executing
2131 their .init section). Previously, the breakpoint would have no effect.
2132 - GDB is now able to backtrace through the signal handler for
2133 non-threaded programs.
2135 PIE (Position Independent Executable) programs debugging is now supported.
2136 This includes debugging execution of PIC (Position Independent Code) shared
2137 libraries although for that, it should be possible to run such libraries as an
2140 *** Changes in GDB 7.0
2142 * GDB now has an interface for JIT compilation. Applications that
2143 dynamically generate code can create symbol files in memory and register
2144 them with GDB. For users, the feature should work transparently, and
2145 for JIT developers, the interface is documented in the GDB manual in the
2146 "JIT Compilation Interface" chapter.
2148 * Tracepoints may now be conditional. The syntax is as for
2149 breakpoints; either an "if" clause appended to the "trace" command,
2150 or the "condition" command is available. GDB sends the condition to
2151 the target for evaluation using the same bytecode format as is used
2152 for tracepoint actions.
2154 * The disassemble command now supports: an optional /r modifier, print the
2155 raw instructions in hex as well as in symbolic form, and an optional /m
2156 modifier to print mixed source+assembly.
2158 * Process record and replay
2160 In a architecture environment that supports ``process record and
2161 replay'', ``process record and replay'' target can record a log of
2162 the process execution, and replay it with both forward and reverse
2165 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2166 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2167 set execution-direction {forward|reverse}, for targets that support
2170 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2171 feature is available with a native GDB running on kernel version
2174 * GDB now has support for multi-byte and wide character sets on the
2175 target. Strings whose character type is wchar_t, char16_t, or
2176 char32_t are now correctly printed. GDB supports wide- and unicode-
2177 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2178 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2179 `printf'. This feature requires iconv to work properly; if your
2180 system does not have a working iconv, GDB can use GNU libiconv. See
2181 the installation instructions for more information.
2183 * GDB now supports automatic retrieval of shared library files from
2184 remote targets. To use this feature, specify a system root that begins
2185 with the `remote:' prefix, either via the `set sysroot' command or via
2186 the `--with-sysroot' configure-time option.
2188 * "info sharedlibrary" now takes an optional regex of libraries to show,
2189 and it now reports if a shared library has no debugging information.
2191 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2192 now complete on file names.
2194 * When completing in expressions, gdb will attempt to limit
2195 completions to allowable structure or union fields, where appropriate.
2196 For instance, consider:
2198 # struct example { int f1; double f2; };
2199 # struct example variable;
2202 If the user types TAB at the end of this command line, the available
2203 completions will be "f1" and "f2".
2205 * Inlined functions are now supported. They show up in backtraces, and
2206 the "step", "next", and "finish" commands handle them automatically.
2208 * GDB now supports the token-splicing (##) and stringification (#)
2209 operators when expanding macros. It also supports variable-arity
2212 * GDB now supports inspecting extra signal information, exported by
2213 the new $_siginfo convenience variable. The feature is currently
2214 implemented on linux ARM, i386 and amd64.
2216 * GDB can now display the VFP floating point registers and NEON vector
2217 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2218 can provide these registers (requires Linux 2.6.30 or later). Remote
2219 and simulator targets may also provide them.
2221 * New remote packets
2224 Search memory for a sequence of bytes.
2227 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2228 operation over reliable transport links. Use of this packet is
2229 controlled by the `set remote noack-packet' command.
2232 Kill the process with the specified process ID. Use this in preference
2233 to `k' when multiprocess protocol extensions are supported.
2236 Obtains additional operating system information
2240 Read or write additional signal information.
2242 * Removed remote protocol undocumented extension
2244 An undocumented extension to the remote protocol's `S' stop reply
2245 packet that permited the stub to pass a process id was removed.
2246 Remote servers should use the `T' stop reply packet instead.
2248 * GDB now supports multiple function calling conventions according to the
2249 DWARF-2 DW_AT_calling_convention function attribute.
2251 * The SH target utilizes the aforementioned change to distinguish between gcc
2252 and Renesas calling convention. It also adds the new CLI commands
2253 `set/show sh calling-convention'.
2255 * GDB can now read compressed debug sections, as produced by GNU gold
2256 with the --compress-debug-sections=zlib flag.
2258 * 64-bit core files are now supported on AIX.
2260 * Thread switching is now supported on Tru64.
2262 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2263 which will be allocated using malloc later in program execution.
2265 * The qXfer:libraries:read remote procotol packet now allows passing a
2266 list of section offsets.
2268 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2269 conditions handling signals delivered during attach or thread creation
2270 have also been fixed.
2272 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2273 From the user's standpoint, all unqualified instances of True and False
2274 are treated as the standard definitions, regardless of context.
2276 * GDB now parses C++ symbol and type names more flexibly. For
2279 template<typename T> class C { };
2282 GDB will now correctly handle all of:
2284 ptype C<char const *>
2285 ptype C<char const*>
2286 ptype C<const char *>
2287 ptype C<const char*>
2289 * New features in the GDB remote stub, gdbserver
2291 - The "--wrapper" command-line argument tells gdbserver to use a
2292 wrapper program to launch programs for debugging.
2294 - On PowerPC and S/390 targets, it is now possible to use a single
2295 gdbserver executable to debug both 32-bit and 64-bit programs.
2296 (This requires gdbserver itself to be built as a 64-bit executable.)
2298 - gdbserver uses the new noack protocol mode for TCP connections to
2299 reduce communications latency, if also supported and enabled in GDB.
2301 - Support for the sparc64-linux-gnu target is now included in
2304 - The amd64-linux build of gdbserver now supports debugging both
2305 32-bit and 64-bit programs.
2307 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2308 now support hardware watchpoints, and will use them automatically
2313 GDB now has support for scripting using Python. Whether this is
2314 available is determined at configure time.
2316 New GDB commands can now be written in Python.
2318 * Ada tasking support
2320 Ada tasks can now be inspected in GDB. The following commands have
2324 Print the list of Ada tasks.
2326 Print detailed information about task number N.
2328 Print the task number of the current task.
2330 Switch the context of debugging to task number N.
2332 * Support for user-defined prefixed commands. The "define" command can
2333 add new commands to existing prefixes, e.g. "target".
2335 * Multi-inferior, multi-process debugging.
2337 GDB now has generalized support for multi-inferior debugging. See
2338 "Debugging Multiple Inferiors" in the manual for more information.
2339 Although availability still depends on target support, the command
2340 set is more uniform now. The GNU/Linux specific multi-forks support
2341 has been migrated to this new framework. This implied some user
2342 visible changes; see "New commands" and also "Removed commands"
2345 * Target descriptions can now describe the target OS ABI. See the
2346 "Target Description Format" section in the user manual for more
2349 * Target descriptions can now describe "compatible" architectures
2350 to indicate that the target can execute applications for a different
2351 architecture in addition to those for the main target architecture.
2352 See the "Target Description Format" section in the user manual for
2355 * Multi-architecture debugging.
2357 GDB now includes general supports for debugging applications on
2358 hybrid systems that use more than one single processor architecture
2359 at the same time. Each such hybrid architecture still requires
2360 specific support to be added. The only hybrid architecture supported
2361 in this version of GDB is the Cell Broadband Engine.
2363 * GDB now supports integrated debugging of Cell/B.E. applications that
2364 use both the PPU and SPU architectures. To enable support for hybrid
2365 Cell/B.E. debugging, you need to configure GDB to support both the
2366 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2367 --enable-targets configure option.
2369 * Non-stop mode debugging.
2371 For some targets, GDB now supports an optional mode of operation in
2372 which you can examine stopped threads while other threads continue
2373 to execute freely. This is referred to as non-stop mode, with the
2374 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2375 section in the user manual for more information.
2377 To be able to support remote non-stop debugging, a remote stub needs
2378 to implement the non-stop mode remote protocol extensions, as
2379 described in the "Remote Non-Stop" section of the user manual. The
2380 GDB remote stub, gdbserver, has been adjusted to support these
2381 extensions on linux targets.
2383 * New commands (for set/show, see "New options" below)
2385 catch syscall [NAME(S) | NUMBER(S)]
2386 Catch system calls. Arguments, which should be names of system
2387 calls or their numbers, mean catch only those syscalls. Without
2388 arguments, every syscall will be caught. When the inferior issues
2389 any of the specified syscalls, GDB will stop and announce the system
2390 call, both when it is called and when its call returns. This
2391 feature is currently available with a native GDB running on the
2392 Linux Kernel, under the following architectures: x86, x86_64,
2393 PowerPC and PowerPC64.
2395 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2397 Search memory for a sequence of bytes.
2399 maint set python print-stack
2400 maint show python print-stack
2401 Show a stack trace when an error is encountered in a Python script.
2404 Invoke CODE by passing it to the Python interpreter.
2409 These allow macros to be defined, undefined, and listed
2413 Show operating system information about processes.
2416 List the inferiors currently under GDB's control.
2419 Switch focus to inferior number NUM.
2422 Detach from inferior number NUM.
2425 Kill inferior number NUM.
2429 set spu stop-on-load
2430 show spu stop-on-load
2431 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2433 set spu auto-flush-cache
2434 show spu auto-flush-cache
2435 Control whether to automatically flush the software-managed cache
2436 during Cell/B.E. debugging.
2438 set sh calling-convention
2439 show sh calling-convention
2440 Control the calling convention used when calling SH target functions.
2443 show debug timestamp
2444 Control display of timestamps with GDB debugging output.
2446 set disassemble-next-line
2447 show disassemble-next-line
2448 Control display of disassembled source lines or instructions when
2451 set remote noack-packet
2452 show remote noack-packet
2453 Set/show the use of remote protocol QStartNoAckMode packet. See above
2454 under "New remote packets."
2456 set remote query-attached-packet
2457 show remote query-attached-packet
2458 Control use of remote protocol `qAttached' (query-attached) packet.
2460 set remote read-siginfo-object
2461 show remote read-siginfo-object
2462 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2465 set remote write-siginfo-object
2466 show remote write-siginfo-object
2467 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2470 set remote reverse-continue
2471 show remote reverse-continue
2472 Control use of remote protocol 'bc' (reverse-continue) packet.
2474 set remote reverse-step
2475 show remote reverse-step
2476 Control use of remote protocol 'bs' (reverse-step) packet.
2478 set displaced-stepping
2479 show displaced-stepping
2480 Control displaced stepping mode. Displaced stepping is a way to
2481 single-step over breakpoints without removing them from the debuggee.
2482 Also known as "out-of-line single-stepping".
2485 show debug displaced
2486 Control display of debugging info for displaced stepping.
2488 maint set internal-error
2489 maint show internal-error
2490 Control what GDB does when an internal error is detected.
2492 maint set internal-warning
2493 maint show internal-warning
2494 Control what GDB does when an internal warning is detected.
2499 Use a wrapper program to launch programs for debugging.
2501 set multiple-symbols (all|ask|cancel)
2502 show multiple-symbols
2503 The value of this variable can be changed to adjust the debugger behavior
2504 when an expression or a breakpoint location contains an ambiguous symbol
2505 name (an overloaded function name, for instance).
2507 set breakpoint always-inserted
2508 show breakpoint always-inserted
2509 Keep breakpoints always inserted in the target, as opposed to inserting
2510 them when resuming the target, and removing them when the target stops.
2511 This option can improve debugger performance on slow remote targets.
2513 set arm fallback-mode (arm|thumb|auto)
2514 show arm fallback-mode
2515 set arm force-mode (arm|thumb|auto)
2517 These commands control how ARM GDB determines whether instructions
2518 are ARM or Thumb. The default for both settings is auto, which uses
2519 the current CPSR value for instructions without symbols; previous
2520 versions of GDB behaved as if "set arm fallback-mode arm".
2522 set disable-randomization
2523 show disable-randomization
2524 Standalone programs run with the virtual address space randomization enabled
2525 by default on some platforms. This option keeps the addresses stable across
2526 multiple debugging sessions.
2530 Control whether other threads are stopped or not when some thread hits
2535 Requests that asynchronous execution is enabled in the target, if available.
2536 In this case, it's possible to resume target in the background, and interact
2537 with GDB while the target is running. "show target-async" displays the
2538 current state of asynchronous execution of the target.
2540 set target-wide-charset
2541 show target-wide-charset
2542 The target-wide-charset is the name of the character set that GDB
2543 uses when printing characters whose type is wchar_t.
2545 set tcp auto-retry (on|off)
2547 set tcp connect-timeout
2548 show tcp connect-timeout
2549 These commands allow GDB to retry failed TCP connections to a remote stub
2550 with a specified timeout period; this is useful if the stub is launched
2551 in parallel with GDB but may not be ready to accept connections immediately.
2553 set libthread-db-search-path
2554 show libthread-db-search-path
2555 Control list of directories which GDB will search for appropriate
2558 set schedule-multiple (on|off)
2559 show schedule-multiple
2560 Allow GDB to resume all threads of all processes or only threads of
2561 the current process.
2565 Use more aggressive caching for accesses to the stack. This improves
2566 performance of remote debugging (particularly backtraces) without
2567 affecting correctness.
2569 set interactive-mode (on|off|auto)
2570 show interactive-mode
2571 Control whether GDB runs in interactive mode (on) or not (off).
2572 When in interactive mode, GDB waits for the user to answer all
2573 queries. Otherwise, GDB does not wait and assumes the default
2574 answer. When set to auto (the default), GDB determines which
2575 mode to use based on the stdin settings.
2580 For program forks, this is replaced by the new more generic `info
2581 inferiors' command. To list checkpoints, you can still use the
2582 `info checkpoints' command, which was an alias for the `info forks'
2586 Replaced by the new `inferior' command. To switch between
2587 checkpoints, you can still use the `restart' command, which was an
2588 alias for the `fork' command.
2591 This is removed, since some targets don't have a notion of
2592 processes. To switch between processes, you can still use the
2593 `inferior' command using GDB's own inferior number.
2596 For program forks, this is replaced by the new more generic `kill
2597 inferior' command. To delete a checkpoint, you can still use the
2598 `delete checkpoint' command, which was an alias for the `delete
2602 For program forks, this is replaced by the new more generic `detach
2603 inferior' command. To detach a checkpoint, you can still use the
2604 `detach checkpoint' command, which was an alias for the `detach
2607 * New native configurations
2609 x86/x86_64 Darwin i[34567]86-*-darwin*
2611 x86_64 MinGW x86_64-*-mingw*
2615 Lattice Mico32 lm32-*
2616 x86 DICOS i[34567]86-*-dicos*
2617 x86_64 DICOS x86_64-*-dicos*
2620 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2621 (mingw32ce) debugging.
2627 These commands were actually not implemented on any target.
2629 *** Changes in GDB 6.8
2631 * New native configurations
2633 NetBSD/hppa hppa*-*netbsd*
2634 Xtensa GNU/Linux xtensa*-*-linux*
2638 NetBSD/hppa hppa*-*-netbsd*
2639 Xtensa GNU/Lunux xtensa*-*-linux*
2641 * Change in command line behavior -- corefiles vs. process ids.
2643 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2644 attaching to process NUMBER fails, GDB no longer attempts to open a
2645 core file named NUMBER. Attaching to a program using the -c option
2646 is no longer supported. Instead, use the '-p' or '--pid' options.
2648 * GDB can now be built as a native debugger for debugging Windows x86
2649 (mingw32) Portable Executable (PE) programs.
2651 * Pending breakpoints no longer change their number when their address
2654 * GDB now supports breakpoints with multiple locations,
2655 including breakpoints on C++ constructors, inside C++ templates,
2656 and in inlined functions.
2658 * GDB's ability to debug optimized code has been improved. GDB more
2659 accurately identifies function bodies and lexical blocks that occupy
2660 more than one contiguous range of addresses.
2662 * Target descriptions can now describe registers for PowerPC.
2664 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2665 registers on PowerPC targets.
2667 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2668 targets even when the libthread_db library is not available.
2670 * The GDB remote stub, gdbserver, now supports the new file transfer
2671 commands (remote put, remote get, and remote delete).
2673 * The GDB remote stub, gdbserver, now supports run and attach in
2674 extended-remote mode.
2676 * hppa*64*-*-hpux11* target broken
2677 The debugger is unable to start a program and fails with the following
2678 error: "Error trying to get information about dynamic linker".
2679 The gdb-6.7 release is also affected.
2681 * GDB now supports the --enable-targets= configure option to allow
2682 building a single GDB executable that supports multiple remote
2683 target architectures.
2685 * GDB now supports debugging C and C++ programs which use the
2686 Decimal Floating Point extension. In addition, the PowerPC target
2687 now has a set of pseudo-registers to inspect decimal float values
2688 stored in two consecutive float registers.
2690 * The -break-insert MI command can optionally create pending
2693 * Improved support for debugging Ada
2694 Many improvements to the Ada language support have been made. These
2696 - Better support for Ada2005 interface types
2697 - Improved handling of arrays and slices in general
2698 - Better support for Taft-amendment types
2699 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2701 - Improved command completion in Ada
2704 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2709 set print frame-arguments (all|scalars|none)
2710 show print frame-arguments
2711 The value of this variable can be changed to control which argument
2712 values should be printed by the debugger when displaying a frame.
2717 Transfer files to and from a remote target, and delete remote files.
2724 Transfer files to and from a remote target, and delete remote files.
2726 * New remote packets
2733 Open, close, read, write, and delete files on the remote system.
2736 Attach to an existing process on the remote system, in extended-remote
2740 Run a new process on the remote system, in extended-remote mode.
2742 *** Changes in GDB 6.7
2744 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2745 bfd, libiberty and opcodes, as revealed by static analysis donated by
2746 Coverity, Inc. (http://scan.coverity.com).
2748 * When looking up multiply-defined global symbols, GDB will now prefer the
2749 symbol definition in the current shared library if it was built using the
2750 -Bsymbolic linker option.
2752 * When the Text User Interface (TUI) is not configured, GDB will now
2753 recognize the -tui command-line option and print a message that the TUI
2756 * The GDB remote stub, gdbserver, now has lower overhead for high
2757 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2759 * GDB for MIPS targets now autodetects whether a remote target provides
2760 32-bit or 64-bit register values.
2762 * Support for C++ member pointers has been improved.
2764 * GDB now understands XML target descriptions, which specify the
2765 target's overall architecture. GDB can read a description from
2766 a local file or over the remote serial protocol.
2768 * Vectors of single-byte data use a new integer type which is not
2769 automatically displayed as character or string data.
2771 * The /s format now works with the print command. It displays
2772 arrays of single-byte integers and pointers to single-byte integers
2775 * Target descriptions can now describe target-specific registers,
2776 for architectures which have implemented the support (currently
2777 only ARM, M68K, and MIPS).
2779 * GDB and the GDB remote stub, gdbserver, now support the XScale
2782 * The GDB remote stub, gdbserver, has been updated to support
2783 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2784 has been rewritten to use the standard GDB remote protocol.
2786 * GDB can now step into C++ functions which are called through thunks.
2788 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2790 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2791 layout. It also supports a TextSeg= and DataSeg= response when only
2792 segment base addresses (rather than offsets) are available.
2794 * The /i format now outputs any trailing branch delay slot instructions
2795 immediately following the last instruction within the count specified.
2797 * The GDB remote protocol "T" stop reply packet now supports a
2798 "library" response. Combined with the new "qXfer:libraries:read"
2799 packet, this response allows GDB to debug shared libraries on targets
2800 where the operating system manages the list of loaded libraries (e.g.
2801 Windows and SymbianOS).
2803 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2804 (DLLs) on Windows and Windows CE targets.
2806 * GDB now supports a faster verification that a .debug file matches its binary
2807 according to its build-id signature, if the signature is present.
2813 Enable or disable hardware flow control (RTS/CTS) on the serial port
2814 when debugging using remote targets.
2816 set mem inaccessible-by-default
2817 show mem inaccessible-by-default
2818 If the target supplies a memory map, for instance via the remote
2819 protocol's "qXfer:memory-map:read" packet, setting this variable
2820 prevents GDB from accessing memory outside the memory map. This
2821 is useful for targets with memory mapped registers or which react
2822 badly to accesses of unmapped address space.
2824 set breakpoint auto-hw
2825 show breakpoint auto-hw
2826 If the target supplies a memory map, for instance via the remote
2827 protocol's "qXfer:memory-map:read" packet, setting this variable
2828 lets GDB use hardware breakpoints automatically for memory regions
2829 where it can not use software breakpoints. This covers both the
2830 "break" command and internal breakpoints used for other commands
2831 including "next" and "finish".
2834 catch exception unhandled
2835 Stop the program execution when Ada exceptions are raised.
2838 Stop the program execution when an Ada assertion failed.
2842 Set an alternate system root for target files. This is a more
2843 general version of "set solib-absolute-prefix", which is now
2844 an alias to "set sysroot".
2847 Provide extended SPU facility status information. This set of
2848 commands is available only when debugging the Cell/B.E. SPU
2851 * New native configurations
2853 OpenBSD/sh sh*-*openbsd*
2856 unset tdesc filename
2858 Use the specified local file as an XML target description, and do
2859 not query the target for its built-in description.
2863 OpenBSD/sh sh*-*-openbsd*
2864 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2865 Toshiba Media Processor mep-elf
2867 * New remote packets
2870 Ignore the specified signals; pass them directly to the debugged program
2871 without stopping other threads or reporting them to GDB.
2873 qXfer:features:read:
2874 Read an XML target description from the target, which describes its
2879 Read or write contents of an spufs file on the target system. These
2880 packets are available only on the Cell/B.E. SPU architecture.
2882 qXfer:libraries:read:
2883 Report the loaded shared libraries. Combined with new "T" packet
2884 response, this packet allows GDB to debug shared libraries on
2885 targets where the operating system manages the list of loaded
2886 libraries (e.g. Windows and SymbianOS).
2890 Support for these obsolete configurations has been removed.
2898 i[34567]86-*-lynxos*
2899 i[34567]86-*-netware*
2900 i[34567]86-*-sco3.2v5*
2901 i[34567]86-*-sco3.2v4*
2903 i[34567]86-*-sysv4.2*
2906 i[34567]86-*-unixware2*
2907 i[34567]86-*-unixware*
2916 * Other removed features
2923 Various m68k-only ROM monitors.
2930 Various Renesas ROM monitors and debugging interfaces for SH and
2935 Support for a Macraigor serial interface to on-chip debugging.
2936 GDB does not directly support the newer parallel or USB
2941 A debug information format. The predecessor to DWARF 2 and
2942 DWARF 3, which are still supported.
2944 Support for the HP aCC compiler on HP-UX/PA-RISC
2946 SOM-encapsulated symbolic debugging information, automatic
2947 invocation of pxdb, and the aCC custom C++ ABI. This does not
2948 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2949 with aCC can still be debugged on an assembly level.
2951 MIPS ".pdr" sections
2953 A MIPS-specific format used to describe stack frame layout
2954 in debugging information.
2958 GDB could work with an older version of Guile to debug
2959 the interpreter and Scheme programs running in it.
2961 set mips stack-arg-size
2962 set mips saved-gpreg-size
2964 Use "set mips abi" to control parameter passing for MIPS.
2966 *** Changes in GDB 6.6
2971 Cell Broadband Engine SPU spu-elf
2973 * GDB can now be configured as a cross-debugger targeting native Windows
2974 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2975 running on a Windows system over TCP/IP to debug Windows programs.
2977 * The GDB remote stub, gdbserver, has been updated to support Windows and
2978 Cygwin debugging. Both single-threaded and multi-threaded programs are
2981 * The "set trust-readonly-sections" command works again. This command was
2982 broken in GDB 6.3, 6.4, and 6.5.
2984 * The "load" command now supports writing to flash memory, if the remote
2985 stub provides the required support.
2987 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2988 longer requires symbolic debug information (e.g. DWARF-2).
2993 unset substitute-path
2994 show substitute-path
2995 Manage a list of substitution rules that GDB uses to rewrite the name
2996 of the directories where the sources are located. This can be useful
2997 for instance when the sources were moved to a different location
2998 between compilation and debugging.
3002 Print each CLI command as it is executed. Each command is prefixed with
3003 a number of `+' symbols representing the nesting depth.
3004 The source command now has a `-v' option to enable the same feature.
3008 The ARM Demon monitor support (RDP protocol, "target rdp").
3010 Kernel Object Display, an embedded debugging feature which only worked with
3011 an obsolete version of Cisco IOS.
3013 The 'set download-write-size' and 'show download-write-size' commands.
3015 * New remote packets
3018 Tell a stub about GDB client features, and request remote target features.
3019 The first feature implemented is PacketSize, which allows the target to
3020 specify the size of packets it can handle - to minimize the number of
3021 packets required and improve performance when connected to a remote
3025 Fetch an OS auxilliary vector from the remote stub. This packet is a
3026 more efficient replacement for qPart:auxv:read.
3028 qXfer:memory-map:read:
3029 Fetch a memory map from the remote stub, including information about
3030 RAM, ROM, and flash memory devices.
3035 Erase and program a flash memory device.
3037 * Removed remote packets
3040 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3041 used it, and only gdbserver implemented it.
3043 *** Changes in GDB 6.5
3047 Renesas M32C/M16C m32c-elf
3049 Morpho Technologies ms1 ms1-elf
3053 init-if-undefined Initialize a convenience variable, but
3054 only if it doesn't already have a value.
3056 The following commands are presently only implemented for native GNU/Linux:
3058 checkpoint Save a snapshot of the program state.
3060 restart <n> Return the program state to a
3061 previously saved state.
3063 info checkpoints List currently saved checkpoints.
3065 delete-checkpoint <n> Delete a previously saved checkpoint.
3067 set|show detach-on-fork Tell gdb whether to detach from a newly
3068 forked process, or to keep debugging it.
3070 info forks List forks of the user program that
3071 are available to be debugged.
3073 fork <n> Switch to debugging one of several
3074 forks of the user program that are
3075 available to be debugged.
3077 delete-fork <n> Delete a fork from the list of forks
3078 that are available to be debugged (and
3079 kill the forked process).
3081 detach-fork <n> Delete a fork from the list of forks
3082 that are available to be debugged (and
3083 allow the process to continue).
3087 Morpho Technologies ms2 ms1-elf
3089 * Improved Windows host support
3091 GDB now builds as a cross debugger hosted on i686-mingw32, including
3092 native console support, and remote communications using either
3093 network sockets or serial ports.
3095 * Improved Modula-2 language support
3097 GDB can now print most types in the Modula-2 syntax. This includes:
3098 basic types, set types, record types, enumerated types, range types,
3099 pointer types and ARRAY types. Procedure var parameters are correctly
3100 printed and hexadecimal addresses and character constants are also
3101 written in the Modula-2 syntax. Best results can be obtained by using
3102 GNU Modula-2 together with the -gdwarf-2 command line option.
3106 The ARM rdi-share module.
3108 The Netware NLM debug server.
3110 *** Changes in GDB 6.4
3112 * New native configurations
3114 OpenBSD/arm arm*-*-openbsd*
3115 OpenBSD/mips64 mips64-*-openbsd*
3119 Morpho Technologies ms1 ms1-elf
3121 * New command line options
3123 --batch-silent As for --batch, but totally silent.
3124 --return-child-result The debugger will exist with the same value
3125 the child (debugged) program exited with.
3126 --eval-command COMMAND, -ex COMMAND
3127 Execute a single GDB CLI command. This may be
3128 specified multiple times and in conjunction
3129 with the --command (-x) option.
3131 * Deprecated commands removed
3133 The following commands, that were deprecated in 2000, have been
3137 set|show arm disassembly-flavor set|show arm disassembler
3138 othernames set arm disassembler
3139 set|show remotedebug set|show debug remote
3140 set|show archdebug set|show debug arch
3141 set|show eventdebug set|show debug event
3144 * New BSD user-level threads support
3146 It is now possible to debug programs using the user-level threads
3147 library on OpenBSD and FreeBSD. Currently supported (target)
3150 FreeBSD/amd64 x86_64-*-freebsd*
3151 FreeBSD/i386 i386-*-freebsd*
3152 OpenBSD/i386 i386-*-openbsd*
3154 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3155 are not yet supported.
3157 * New support for Matsushita MN10300 w/sim added
3158 (Work in progress). mn10300-elf.
3160 * REMOVED configurations and files
3162 VxWorks and the XDR protocol *-*-vxworks
3163 Motorola MCORE mcore-*-*
3164 National Semiconductor NS32000 ns32k-*-*
3166 * New "set print array-indexes" command
3168 After turning this setting "on", GDB prints the index of each element
3169 when displaying arrays. The default is "off" to preserve the previous
3172 * VAX floating point support
3174 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3176 * User-defined command support
3178 In addition to using $arg0..$arg9 for argument passing, it is now possible
3179 to use $argc to determine now many arguments have been passed. See the
3180 section on user-defined commands in the user manual for more information.
3182 *** Changes in GDB 6.3:
3184 * New command line option
3186 GDB now accepts -l followed by a number to set the timeout for remote
3189 * GDB works with GCC -feliminate-dwarf2-dups
3191 GDB now supports a more compact representation of DWARF-2 debug
3192 information using DW_FORM_ref_addr references. These are produced
3193 by GCC with the option -feliminate-dwarf2-dups and also by some
3194 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3195 to use -feliminate-dwarf2-dups.
3197 * Internationalization
3199 When supported by the host system, GDB will be built with
3200 internationalization (libintl). The task of marking up the sources is
3201 continued, we're looking forward to our first translation.
3205 Initial support for debugging programs compiled with the GNAT
3206 implementation of the Ada programming language has been integrated
3207 into GDB. In this release, support is limited to expression evaluation.
3209 * New native configurations
3211 GNU/Linux/m32r m32r-*-linux-gnu
3215 GDB's remote protocol now includes support for the 'p' packet. This
3216 packet is used to fetch individual registers from a remote inferior.
3218 * END-OF-LIFE registers[] compatibility module
3220 GDB's internal register infrastructure has been completely rewritten.
3221 The new infrastructure making possible the implementation of key new
3222 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3225 GDB 6.3 will be the last release to include the the registers[]
3226 compatibility module that allowed out-of-date configurations to
3227 continue to work. This change directly impacts the following
3237 powerpc bdm protocol
3239 Unless there is activity to revive these configurations, they will be
3240 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3242 * OBSOLETE configurations and files
3244 Configurations that have been declared obsolete in this release have
3245 been commented out. Unless there is activity to revive these
3246 configurations, the next release of GDB will have their sources
3247 permanently REMOVED.
3256 *** Changes in GDB 6.2.1:
3258 * MIPS `break main; run' gave an heuristic-fence-post warning
3260 When attempting to run even a simple program, a warning about
3261 heuristic-fence-post being hit would be reported. This problem has
3264 * MIPS IRIX 'long double' crashed GDB
3266 When examining a long double variable, GDB would get a segmentation
3267 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3268 IRIX long double values).
3272 A bug in the VAX stack code was causing problems with the "next"
3273 command. This problem has been fixed.
3275 *** Changes in GDB 6.2:
3277 * Fix for ``many threads''
3279 On GNU/Linux systems that use the NPTL threads library, a program
3280 rapidly creating and deleting threads would confuse GDB leading to the
3283 ptrace: No such process.
3284 thread_db_get_info: cannot get thread info: generic error
3286 This problem has been fixed.
3288 * "-async" and "-noasync" options removed.
3290 Support for the broken "-noasync" option has been removed (it caused
3293 * New ``start'' command.
3295 This command runs the program until the begining of the main procedure.
3297 * New BSD Kernel Data Access Library (libkvm) interface
3299 Using ``target kvm'' it is now possible to debug kernel core dumps and
3300 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3301 platforms. Currently supported (native-only) configurations are:
3303 FreeBSD/amd64 x86_64-*-freebsd*
3304 FreeBSD/i386 i?86-*-freebsd*
3305 NetBSD/i386 i?86-*-netbsd*
3306 NetBSD/m68k m68*-*-netbsd*
3307 NetBSD/sparc sparc-*-netbsd*
3308 OpenBSD/amd64 x86_64-*-openbsd*
3309 OpenBSD/i386 i?86-*-openbsd*
3310 OpenBSD/m68k m68*-openbsd*
3311 OpenBSD/sparc sparc-*-openbsd*
3313 * Signal trampoline code overhauled
3315 Many generic problems with GDB's signal handling code have been fixed.
3316 These include: backtraces through non-contiguous stacks; recognition
3317 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3318 call; backtrace through a signal trampoline; step into and out of
3319 signal handlers; and single-stepping in the signal trampoline.
3321 Please note that kernel bugs are a limiting factor here. These
3322 features have been shown to work on an s390 GNU/Linux system that
3323 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3325 * Cygwin support for DWARF 2 added.
3327 * New native configurations
3329 GNU/Linux/hppa hppa*-*-linux*
3330 OpenBSD/hppa hppa*-*-openbsd*
3331 OpenBSD/m68k m68*-*-openbsd*
3332 OpenBSD/m88k m88*-*-openbsd*
3333 OpenBSD/powerpc powerpc-*-openbsd*
3334 NetBSD/vax vax-*-netbsd*
3335 OpenBSD/vax vax-*-openbsd*
3337 * END-OF-LIFE frame compatibility module
3339 GDB's internal frame infrastructure has been completely rewritten.
3340 The new infrastructure making it possible to support key new features
3341 including DWARF 2 Call Frame Information. To aid in the task of
3342 migrating old configurations to this new infrastructure, a
3343 compatibility module, that allowed old configurations to continue to
3344 work, was also included.
3346 GDB 6.2 will be the last release to include this frame compatibility
3347 module. This change directly impacts the following configurations:
3357 Unless there is activity to revive these configurations, they will be
3358 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3360 * REMOVED configurations and files
3362 Sun 3, running SunOS 3 m68*-*-sunos3*
3363 Sun 3, running SunOS 4 m68*-*-sunos4*
3364 Sun 2, running SunOS 3 m68000-*-sunos3*
3365 Sun 2, running SunOS 4 m68000-*-sunos4*
3366 Motorola 680x0 running LynxOS m68*-*-lynxos*
3367 AT&T 3b1/Unix pc m68*-att-*
3368 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3369 decstation mips-dec-* mips-little-*
3370 riscos mips-*-riscos* mips-*-sysv*
3371 sonymips mips-sony-*
3372 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3374 *** Changes in GDB 6.1.1:
3376 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3378 The TUI (Text-mode User Interface) is now built as part of a default
3379 GDB configuration. It is enabled by either selecting the TUI with the
3380 command line option "-i=tui" or by running the separate "gdbtui"
3381 program. For more information on the TUI, see the manual "Debugging
3384 * Pending breakpoint support (also included in GDB 6.1)
3386 Support has been added to allow you to specify breakpoints in shared
3387 libraries that have not yet been loaded. If a breakpoint location
3388 cannot be found, and the "breakpoint pending" option is set to auto,
3389 GDB queries you if you wish to make the breakpoint pending on a future
3390 shared-library load. If and when GDB resolves the breakpoint symbol,
3391 the pending breakpoint is removed as one or more regular breakpoints
3394 Pending breakpoints are very useful for GCJ Java debugging.
3396 * Fixed ISO-C build problems
3398 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3399 non ISO-C code that stopped them being built using a more strict ISO-C
3400 compiler (e.g., IBM's C compiler).
3402 * Fixed build problem on IRIX 5
3404 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3405 wasn't able to compile compile on an IRIX 5 system.
3407 * Added execute permission to gdb/gdbserver/configure
3409 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3410 permission. This bug would cause configure to fail on a number of
3411 systems (Solaris, IRIX). Ref: server/519.
3413 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3415 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3416 has been updated to use constant array sizes.
3418 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3420 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3421 its generated DWARF Call Frame Info. This encoding was causing GDB to
3422 panic, that panic has been fixed. Ref: gdb/1628.
3424 * Fixed a problem when examining parameters in shared library code.
3426 When examining parameters in optimized shared library code generated
3427 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3428 not available''. GDB now correctly displays the variable's value.
3430 *** Changes in GDB 6.1:
3432 * Removed --with-mmalloc
3434 Support for the mmalloc memory manager has been removed, as it
3435 conflicted with the internal gdb byte cache.
3437 * Changes in AMD64 configurations
3439 The AMD64 target now includes the %cs and %ss registers. As a result
3440 the AMD64 remote protocol has changed; this affects the floating-point
3441 and SSE registers. If you rely on those registers for your debugging,
3442 you should upgrade gdbserver on the remote side.
3444 * Revised SPARC target
3446 The SPARC target has been completely revised, incorporating the
3447 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3448 support for LynxOS and SunOS 4 has been dropped. Calling functions
3449 from within GDB on operating systems with a non-executable stack
3450 (Solaris, OpenBSD) now works.
3454 GDB has a new C++ demangler which does a better job on the mangled
3455 names generated by current versions of g++. It also runs faster, so
3456 with this and other changes gdb should now start faster on large C++
3459 * DWARF 2 Location Expressions
3461 GDB support for location expressions has been extended to support function
3462 arguments and frame bases. Older versions of GDB could crash when they
3465 * C++ nested types and namespaces
3467 GDB's support for nested types and namespaces in C++ has been
3468 improved, especially if you use the DWARF 2 debugging format. (This
3469 is the default for recent versions of GCC on most platforms.)
3470 Specifically, if you have a class "Inner" defined within a class or
3471 namespace "Outer", then GDB realizes that the class's name is
3472 "Outer::Inner", not simply "Inner". This should greatly reduce the
3473 frequency of complaints about not finding RTTI symbols. In addition,
3474 if you are stopped at inside of a function defined within a namespace,
3475 GDB modifies its name lookup accordingly.
3477 * New native configurations
3479 NetBSD/amd64 x86_64-*-netbsd*
3480 OpenBSD/amd64 x86_64-*-openbsd*
3481 OpenBSD/alpha alpha*-*-openbsd*
3482 OpenBSD/sparc sparc-*-openbsd*
3483 OpenBSD/sparc64 sparc64-*-openbsd*
3485 * New debugging protocols
3487 M32R with SDI protocol m32r-*-elf*
3489 * "set prompt-escape-char" command deleted.
3491 The command "set prompt-escape-char" has been deleted. This command,
3492 and its very obscure effet on GDB's prompt, was never documented,
3493 tested, nor mentioned in the NEWS file.
3495 * OBSOLETE configurations and files
3497 Configurations that have been declared obsolete in this release have
3498 been commented out. Unless there is activity to revive these
3499 configurations, the next release of GDB will have their sources
3500 permanently REMOVED.
3502 Sun 3, running SunOS 3 m68*-*-sunos3*
3503 Sun 3, running SunOS 4 m68*-*-sunos4*
3504 Sun 2, running SunOS 3 m68000-*-sunos3*
3505 Sun 2, running SunOS 4 m68000-*-sunos4*
3506 Motorola 680x0 running LynxOS m68*-*-lynxos*
3507 AT&T 3b1/Unix pc m68*-att-*
3508 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3509 decstation mips-dec-* mips-little-*
3510 riscos mips-*-riscos* mips-*-sysv*
3511 sonymips mips-sony-*
3512 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3514 * REMOVED configurations and files
3516 SGI Irix-4.x mips-sgi-irix4 or iris4
3517 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3518 Z8000 simulator z8k-zilog-none or z8ksim
3519 Matsushita MN10200 w/simulator mn10200-*-*
3520 H8/500 simulator h8500-hitachi-hms or h8500hms
3521 HP/PA running BSD hppa*-*-bsd*
3522 HP/PA running OSF/1 hppa*-*-osf*
3523 HP/PA Pro target hppa*-*-pro*
3524 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3525 386BSD i[3456]86-*-bsd*
3526 Sequent family i[3456]86-sequent-sysv4*
3527 i[3456]86-sequent-sysv*
3528 i[3456]86-sequent-bsd*
3529 SPARC running LynxOS sparc-*-lynxos*
3530 SPARC running SunOS 4 sparc-*-sunos4*
3531 Tsqware Sparclet sparclet-*-*
3532 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3534 *** Changes in GDB 6.0:
3538 Support for debugging the Objective-C programming language has been
3539 integrated into GDB.
3541 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3543 DWARF 2's Call Frame Information makes available compiler generated
3544 information that more exactly describes the program's run-time stack.
3545 By using this information, GDB is able to provide more robust stack
3548 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3549 have been updated to use a new backtrace mechanism which includes
3550 DWARF 2 CFI support.
3554 GDB's remote protocol has been extended to include support for hosted
3555 file I/O (where the remote target uses GDB's file system). See GDB's
3556 remote protocol documentation for details.
3558 * All targets using the new architecture framework.
3560 All of GDB's targets have been updated to use the new internal
3561 architecture framework. The way is now open for future GDB releases
3562 to include cross-architecture native debugging support (i386 on amd64,
3565 * GNU/Linux's Thread Local Storage (TLS)
3567 GDB now includes support for for the GNU/Linux implementation of
3568 per-thread variables.
3570 * GNU/Linux's Native POSIX Thread Library (NPTL)
3572 GDB's thread code has been updated to work with either the new
3573 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3575 * Separate debug info.
3577 GDB, in conjunction with BINUTILS, now supports a mechanism for
3578 automatically loading debug information from a separate file. Instead
3579 of shipping full debug and non-debug versions of system libraries,
3580 system integrators can now instead ship just the stripped libraries
3581 and optional debug files.
3583 * DWARF 2 Location Expressions
3585 DWARF 2 Location Expressions allow the compiler to more completely
3586 describe the location of variables (even in optimized code) to the
3589 GDB now includes preliminary support for location expressions (support
3590 for DW_OP_piece is still missing).
3594 A number of long standing bugs that caused GDB to die while starting a
3595 Java application have been fixed. GDB's Java support is now
3596 considered "useable".
3598 * GNU/Linux support for fork, vfork, and exec.
3600 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3601 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3604 * GDB supports logging output to a file
3606 There are two new commands, "set logging" and "show logging", which can be
3607 used to capture GDB's output to a file.
3609 * The meaning of "detach" has changed for gdbserver
3611 The "detach" command will now resume the application, as documented. To
3612 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3615 * d10v, m68hc11 `regs' command deprecated
3617 The `info registers' command has been updated so that it displays the
3618 registers using a format identical to the old `regs' command.
3622 A new command, "maint set profile on/off", has been added. This command can
3623 be used to enable or disable profiling while running GDB, to profile a
3624 session or a set of commands. In addition there is a new configure switch,
3625 "--enable-profiling", which will cause GDB to be compiled with profiling
3626 data, for more informative profiling results.
3628 * Default MI syntax changed to "mi2".
3630 The default MI (machine interface) syntax, enabled by the command line
3631 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3632 "mi1", can be enabled by specifying the option "-i=mi1".
3634 Support for the original "mi0" syntax (included in GDB 5.0) has been
3637 Fix for gdb/192: removed extraneous space when displaying frame level.
3638 Fix for gdb/672: update changelist is now output in mi list format.
3639 Fix for gdb/702: a -var-assign that updates the value now shows up
3640 in a subsequent -var-update.
3642 * New native configurations.
3644 FreeBSD/amd64 x86_64-*-freebsd*
3646 * Multi-arched targets.
3648 HP/PA HPUX11 hppa*-*-hpux*
3649 Renesas M32R/D w/simulator m32r-*-elf*
3651 * OBSOLETE configurations and files
3653 Configurations that have been declared obsolete in this release have
3654 been commented out. Unless there is activity to revive these
3655 configurations, the next release of GDB will have their sources
3656 permanently REMOVED.
3658 Z8000 simulator z8k-zilog-none or z8ksim
3659 Matsushita MN10200 w/simulator mn10200-*-*
3660 H8/500 simulator h8500-hitachi-hms or h8500hms
3661 HP/PA running BSD hppa*-*-bsd*
3662 HP/PA running OSF/1 hppa*-*-osf*
3663 HP/PA Pro target hppa*-*-pro*
3664 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3665 Sequent family i[3456]86-sequent-sysv4*
3666 i[3456]86-sequent-sysv*
3667 i[3456]86-sequent-bsd*
3668 Tsqware Sparclet sparclet-*-*
3669 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3671 * REMOVED configurations and files
3674 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3675 IBM AIX PS/2 i[3456]86-*-aix
3676 i386 running Mach 3.0 i[3456]86-*-mach3*
3677 i386 running Mach i[3456]86-*-mach*
3678 i386 running OSF/1 i[3456]86-*osf1mk*
3679 HP/Apollo 68k Family m68*-apollo*-sysv*,
3681 m68*-hp-bsd*, m68*-hp-hpux*
3682 Argonaut Risc Chip (ARC) arc-*-*
3683 Mitsubishi D30V d30v-*-*
3684 Fujitsu FR30 fr30-*-elf*
3685 OS/9000 i[34]86-*-os9k
3686 I960 with MON960 i960-*-coff
3688 * MIPS $fp behavior changed
3690 The convenience variable $fp, for the MIPS, now consistently returns
3691 the address of the current frame's base. Previously, depending on the
3692 context, $fp could refer to either $sp or the current frame's base
3693 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3694 The GNU Source-Level Debugger''.
3696 *** Changes in GDB 5.3:
3698 * GNU/Linux shared library multi-threaded performance improved.
3700 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3701 `/proc', in preference to `ptrace' for memory reads. This may result
3702 in an improvement in the start-up time of multi-threaded, shared
3703 library applications when run under GDB. One GDB user writes: ``loads
3704 shared libs like mad''.
3706 * ``gdbserver'' now supports multi-threaded applications on some targets
3708 Support for debugging multi-threaded applications which use
3709 the GNU/Linux LinuxThreads package has been added for
3710 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3711 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3713 * GDB now supports C/C++ preprocessor macros.
3715 GDB now expands preprocessor macro invocations in C/C++ expressions,
3716 and provides various commands for showing macro definitions and how
3719 The new command `macro expand EXPRESSION' expands any macro
3720 invocations in expression, and shows the result.
3722 The new command `show macro MACRO-NAME' shows the definition of the
3723 macro named MACRO-NAME, and where it was defined.
3725 Most compilers don't include information about macros in the debugging
3726 information by default. In GCC 3.1, for example, you need to compile
3727 your program with the options `-gdwarf-2 -g3'. If the macro
3728 information is present in the executable, GDB will read it.
3730 * Multi-arched targets.
3732 DEC Alpha (partial) alpha*-*-*
3733 DEC VAX (partial) vax-*-*
3735 National Semiconductor NS32000 (partial) ns32k-*-*
3736 Motorola 68000 (partial) m68k-*-*
3737 Motorola MCORE mcore-*-*
3741 Fujitsu FRV architecture added by Red Hat frv*-*-*
3744 * New native configurations
3746 Alpha NetBSD alpha*-*-netbsd*
3747 SH NetBSD sh*-*-netbsdelf*
3748 MIPS NetBSD mips*-*-netbsd*
3749 UltraSPARC NetBSD sparc64-*-netbsd*
3751 * OBSOLETE configurations and files
3753 Configurations that have been declared obsolete in this release have
3754 been commented out. Unless there is activity to revive these
3755 configurations, the next release of GDB will have their sources
3756 permanently REMOVED.
3758 Mitsubishi D30V d30v-*-*
3759 OS/9000 i[34]86-*-os9k
3760 IBM AIX PS/2 i[3456]86-*-aix
3761 Fujitsu FR30 fr30-*-elf*
3762 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3763 Argonaut Risc Chip (ARC) arc-*-*
3764 i386 running Mach 3.0 i[3456]86-*-mach3*
3765 i386 running Mach i[3456]86-*-mach*
3766 i386 running OSF/1 i[3456]86-*osf1mk*
3767 HP/Apollo 68k Family m68*-apollo*-sysv*,
3769 m68*-hp-bsd*, m68*-hp-hpux*
3770 I960 with MON960 i960-*-coff
3772 * OBSOLETE languages
3774 CHILL, a Pascal like language used by telecommunications companies.
3776 * REMOVED configurations and files
3778 AMD 29k family via UDI a29k-amd-udi, udi29k
3779 A29K VxWorks a29k-*-vxworks
3780 AMD 29000 embedded, using EBMON a29k-none-none
3781 AMD 29000 embedded with COFF a29k-none-coff
3782 AMD 29000 embedded with a.out a29k-none-aout
3784 testsuite/gdb.hp/gdb.threads-hp/ directory
3786 * New command "set max-user-call-depth <nnn>"
3788 This command allows the user to limit the call depth of user-defined
3789 commands. The default is 1024.
3791 * Changes in FreeBSD/i386 native debugging.
3793 Support for the "generate-core-file" has been added.
3795 * New commands "dump", "append", and "restore".
3797 These commands allow data to be copied from target memory
3798 to a bfd-format or binary file (dump and append), and back
3799 from a file into memory (restore).
3801 * Improved "next/step" support on multi-processor Alpha Tru64.
3803 The previous single-step mechanism could cause unpredictable problems,
3804 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3805 of a software single-step mechanism prevents this.
3807 *** Changes in GDB 5.2.1:
3815 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3816 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3817 Fix, by Joel Brobecker imported from mainline.
3819 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3820 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3821 Fix, by Fred Fish, imported from mainline.
3823 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3824 Surprisingly enough, it works now.
3825 By Michal Ludvig, imported from mainline.
3827 i386 hardware watchpoint support:
3828 avoid misses on second run for some targets.
3829 By Pierre Muller, imported from mainline.
3831 *** Changes in GDB 5.2:
3833 * New command "set trust-readonly-sections on[off]".
3835 This command is a hint that tells gdb that read-only sections
3836 really are read-only (ie. that their contents will not change).
3837 In this mode, gdb will go to the object file rather than the
3838 target to read memory from read-only sections (such as ".text").
3839 This can be a significant performance improvement on some
3840 (notably embedded) targets.
3842 * New command "generate-core-file" (or "gcore").
3844 This new gdb command allows the user to drop a core file of the child
3845 process state at any time. So far it's been implemented only for
3846 GNU/Linux and Solaris, but should be relatively easily ported to other
3847 hosts. Argument is core file name (defaults to core.<pid>).
3849 * New command line option
3851 GDB now accepts --pid or -p followed by a process id.
3853 * Change in command line behavior -- corefiles vs. process ids.
3855 There is a subtle behavior in the way in which GDB handles
3856 command line arguments. The first non-flag argument is always
3857 a program to debug, but the second non-flag argument may either
3858 be a corefile or a process id. Previously, GDB would attempt to
3859 open the second argument as a corefile, and if that failed, would
3860 issue a superfluous error message and then attempt to attach it as
3861 a process. Now, if the second argument begins with a non-digit,
3862 it will be treated as a corefile. If it begins with a digit,
3863 GDB will attempt to attach it as a process, and if no such process
3864 is found, will then attempt to open it as a corefile.
3866 * Changes in ARM configurations.
3868 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3869 configuration is fully multi-arch.
3871 * New native configurations
3873 ARM NetBSD arm*-*-netbsd*
3874 x86 OpenBSD i[3456]86-*-openbsd*
3875 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3876 Sparc64 running FreeBSD sparc64-*-freebsd*
3880 Sanyo XStormy16 xstormy16-elf
3882 * OBSOLETE configurations and files
3884 Configurations that have been declared obsolete in this release have
3885 been commented out. Unless there is activity to revive these
3886 configurations, the next release of GDB will have their sources
3887 permanently REMOVED.
3889 AMD 29k family via UDI a29k-amd-udi, udi29k
3890 A29K VxWorks a29k-*-vxworks
3891 AMD 29000 embedded, using EBMON a29k-none-none
3892 AMD 29000 embedded with COFF a29k-none-coff
3893 AMD 29000 embedded with a.out a29k-none-aout
3895 testsuite/gdb.hp/gdb.threads-hp/ directory
3897 * REMOVED configurations and files
3899 TI TMS320C80 tic80-*-*
3901 PowerPC Solaris powerpcle-*-solaris*
3902 PowerPC Windows NT powerpcle-*-cygwin32
3903 PowerPC Netware powerpc-*-netware*
3904 Harris/CXUX m88k m88*-harris-cxux*
3905 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3906 ns32k-utek-sysv* ns32k-utek-*
3907 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3908 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3909 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3910 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3911 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3913 * Changes to command line processing
3915 The new `--args' feature can be used to specify command-line arguments
3916 for the inferior from gdb's command line.
3918 * Changes to key bindings
3920 There is a new `operate-and-get-next' function bound to `C-o'.
3922 *** Changes in GDB 5.1.1
3924 Fix compile problem on DJGPP.
3926 Fix a problem with floating-point registers on the i386 being
3929 Fix to stop GDB crashing on .debug_str debug info.
3931 Numerous documentation fixes.
3933 Numerous testsuite fixes.
3935 *** Changes in GDB 5.1:
3937 * New native configurations
3939 Alpha FreeBSD alpha*-*-freebsd*
3940 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3941 MIPS GNU/Linux mips*-*-linux*
3942 MIPS SGI Irix 6.x mips*-sgi-irix6*
3943 ia64 AIX ia64-*-aix*
3944 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3948 Motorola 68HC11 and 68HC12 m68hc11-elf
3950 UltraSparc running GNU/Linux sparc64-*-linux*
3952 * OBSOLETE configurations and files
3954 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3955 Harris/CXUX m88k m88*-harris-cxux*
3956 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3957 ns32k-utek-sysv* ns32k-utek-*
3958 TI TMS320C80 tic80-*-*
3960 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3961 PowerPC Solaris powerpcle-*-solaris*
3962 PowerPC Windows NT powerpcle-*-cygwin32
3963 PowerPC Netware powerpc-*-netware*
3964 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3965 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3966 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3967 Apple Macintosh (MPW) host N/A
3969 stuff.c (Program to stuff files into a specially prepared space in kdb)
3970 kdb-start.c (Main loop for the standalone kernel debugger)
3972 Configurations that have been declared obsolete in this release have
3973 been commented out. Unless there is activity to revive these
3974 configurations, the next release of GDB will have their sources
3975 permanently REMOVED.
3977 * REMOVED configurations and files
3979 Altos 3068 m68*-altos-*
3980 Convex c1-*-*, c2-*-*
3982 ARM RISCix arm-*-* (as host)
3986 * GDB has been converted to ISO C.
3988 GDB's source code has been converted to ISO C. In particular, the
3989 sources are fully protoized, and rely on standard headers being
3994 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3996 * The MI enabled by default.
3998 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3999 revised and enabled by default. Packages which use GDB as a debugging
4000 engine behind a UI or another front end are encouraged to switch to
4001 using the GDB/MI interface, instead of the old annotations interface
4002 which is now deprecated.
4004 * Support for debugging Pascal programs.
4006 GDB now includes support for debugging Pascal programs. The following
4007 main features are supported:
4009 - Pascal-specific data types such as sets;
4011 - automatic recognition of Pascal sources based on file-name
4014 - Pascal-style display of data types, variables, and functions;
4016 - a Pascal expression parser.
4018 However, some important features are not yet supported.
4020 - Pascal string operations are not supported at all;
4022 - there are some problems with boolean types;
4024 - Pascal type hexadecimal constants are not supported
4025 because they conflict with the internal variables format;
4027 - support for Pascal objects and classes is not full yet;
4029 - unlike Pascal, GDB is case-sensitive for symbol names.
4031 * Changes in completion.
4033 Commands such as `shell', `run' and `set args', which pass arguments
4034 to inferior programs, now complete on file names, similar to what
4035 users expect at the shell prompt.
4037 Commands which accept locations, such as `disassemble', `print',
4038 `breakpoint', `until', etc. now complete on filenames as well as
4039 program symbols. Thus, if you type "break foob TAB", and the source
4040 files linked into the programs include `foobar.c', that file name will
4041 be one of the candidates for completion. However, file names are not
4042 considered for completion after you typed a colon that delimits a file
4043 name from a name of a function in that file, as in "break foo.c:bar".
4045 `set demangle-style' completes on available demangling styles.
4047 * New platform-independent commands:
4049 It is now possible to define a post-hook for a command as well as a
4050 hook that runs before the command. For more details, see the
4051 documentation of `hookpost' in the GDB manual.
4053 * Changes in GNU/Linux native debugging.
4055 Support for debugging multi-threaded programs has been completely
4056 revised for all platforms except m68k and sparc. You can now debug as
4057 many threads as your system allows you to have.
4059 Attach/detach is supported for multi-threaded programs.
4061 Support for SSE registers was added for x86. This doesn't work for
4062 multi-threaded programs though.
4064 * Changes in MIPS configurations.
4066 Multi-arch support is enabled for all MIPS configurations.
4068 GDB can now be built as native debugger on SGI Irix 6.x systems for
4069 debugging n32 executables. (Debugging 64-bit executables is not yet
4072 * Unified support for hardware watchpoints in all x86 configurations.
4074 Most (if not all) native x86 configurations support hardware-assisted
4075 breakpoints and watchpoints in a unified manner. This support
4076 implements debug register sharing between watchpoints, which allows to
4077 put a virtually infinite number of watchpoints on the same address,
4078 and also supports watching regions up to 16 bytes with several debug
4081 The new maintenance command `maintenance show-debug-regs' toggles
4082 debugging print-outs in functions that insert, remove, and test
4083 watchpoints and hardware breakpoints.
4085 * Changes in the DJGPP native configuration.
4087 New command ``info dos sysinfo'' displays assorted information about
4088 the CPU, OS, memory, and DPMI server.
4090 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4091 display information about segment descriptors stored in GDT, LDT, and
4094 New commands ``info dos pde'' and ``info dos pte'' display entries
4095 from Page Directory and Page Tables (for now works with CWSDPMI only).
4096 New command ``info dos address-pte'' displays the Page Table entry for
4097 a given linear address.
4099 GDB can now pass command lines longer than 126 characters to the
4100 program being debugged (requires an update to the libdbg.a library
4101 which is part of the DJGPP development kit).
4103 DWARF2 debug info is now supported.
4105 It is now possible to `step' and `next' through calls to `longjmp'.
4107 * Changes in documentation.
4109 All GDB documentation was converted to GFDL, the GNU Free
4110 Documentation License.
4112 Tracepoints-related commands are now fully documented in the GDB
4115 TUI, the Text-mode User Interface, is now documented in the manual.
4117 Tracepoints-related commands are now fully documented in the GDB
4120 The "GDB Internals" manual now has an index. It also includes
4121 documentation of `ui_out' functions, GDB coding standards, x86
4122 hardware watchpoints, and memory region attributes.
4124 * GDB's version number moved to ``version.in''
4126 The Makefile variable VERSION has been replaced by the file
4127 ``version.in''. People creating GDB distributions should update the
4128 contents of this file.
4132 GUD support is now a standard part of the EMACS distribution.
4134 *** Changes in GDB 5.0:
4136 * Improved support for debugging FP programs on x86 targets
4138 Unified and much-improved support for debugging floating-point
4139 programs on all x86 targets. In particular, ``info float'' now
4140 displays the FP registers in the same format on all x86 targets, with
4141 greater level of detail.
4143 * Improvements and bugfixes in hardware-assisted watchpoints
4145 It is now possible to watch array elements, struct members, and
4146 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4147 on x86 targets no longer erroneously trigger when the address is
4150 * Improvements in the native DJGPP version of GDB
4152 The distribution now includes all the scripts and auxiliary files
4153 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4154 machines ``out of the box''.
4156 The DJGPP version can now debug programs that use signals. It is
4157 possible to catch signals that happened in the debuggee, deliver
4158 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4159 would kill the program being debugged.) Programs that hook hardware
4160 interrupts (keyboard, timer, etc.) can also be debugged.
4162 It is now possible to debug DJGPP programs that redirect their
4163 standard handles or switch them to raw (as opposed to cooked) mode, or
4164 even close them. The command ``run < foo > bar'' works as expected,
4165 and ``info terminal'' reports useful information about the debuggee's
4166 terminal, including raw/cooked mode, redirection, etc.
4168 The DJGPP version now uses termios functions for console I/O, which
4169 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4172 DOS-style file names with drive letters are now fully supported by
4175 It is now possible to debug DJGPP programs that switch their working
4176 directory. It is also possible to rerun the debuggee any number of
4177 times without restarting GDB; thus, you can use the same setup,
4178 breakpoints, etc. for many debugging sessions.
4180 * New native configurations
4182 ARM GNU/Linux arm*-*-linux*
4183 PowerPC GNU/Linux powerpc-*-linux*
4187 Motorola MCore mcore-*-*
4188 x86 VxWorks i[3456]86-*-vxworks*
4189 PowerPC VxWorks powerpc-*-vxworks*
4190 TI TMS320C80 tic80-*-*
4192 * OBSOLETE configurations
4194 Altos 3068 m68*-altos-*
4195 Convex c1-*-*, c2-*-*
4197 ARM RISCix arm-*-* (as host)
4200 Configurations that have been declared obsolete will be commented out,
4201 but the code will be left in place. If there is no activity to revive
4202 these configurations before the next release of GDB, the sources will
4203 be permanently REMOVED.
4205 * Gould support removed
4207 Support for the Gould PowerNode and NP1 has been removed.
4209 * New features for SVR4
4211 On SVR4 native platforms (such as Solaris), if you attach to a process
4212 without first loading a symbol file, GDB will now attempt to locate and
4213 load symbols from the running process's executable file.
4215 * Many C++ enhancements
4217 C++ support has been greatly improved. Overload resolution now works properly
4218 in almost all cases. RTTI support is on the way.
4220 * Remote targets can connect to a sub-program
4222 A popen(3) style serial-device has been added. This device starts a
4223 sub-process (such as a stand-alone simulator) and then communicates
4224 with that. The sub-program to run is specified using the syntax
4225 ``|<program> <args>'' vis:
4227 (gdb) set remotedebug 1
4228 (gdb) target extended-remote |mn10300-elf-sim program-args
4230 * MIPS 64 remote protocol
4232 A long standing bug in the mips64 remote protocol where by GDB
4233 expected certain 32 bit registers (ex SR) to be transfered as 32
4234 instead of 64 bits has been fixed.
4236 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4237 added to provide backward compatibility with older versions of GDB.
4239 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4241 The command ``set remotebinarydownload'' command has been replaced by
4242 ``set remote X-packet''. Other commands in ``set remote'' family
4243 include ``set remote P-packet''.
4245 * Breakpoint commands accept ranges.
4247 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4248 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4249 ``tracepoint passcount'' also accepts a range of tracepoints.
4251 * ``apropos'' command added.
4253 The ``apropos'' command searches through command names and
4254 documentation strings, printing out matches, making it much easier to
4255 try to find a command that does what you are looking for.
4259 A new machine oriented interface (MI) has been added to GDB. This
4260 interface is designed for debug environments running GDB as a separate
4261 process. This is part of the long term libGDB project. See the
4262 "GDB/MI" chapter of the GDB manual for further information. It can be
4263 enabled by configuring with:
4265 .../configure --enable-gdbmi
4267 *** Changes in GDB-4.18:
4269 * New native configurations
4271 HP-UX 10.20 hppa*-*-hpux10.20
4272 HP-UX 11.x hppa*-*-hpux11.0*
4273 M68K GNU/Linux m68*-*-linux*
4277 Fujitsu FR30 fr30-*-elf*
4278 Intel StrongARM strongarm-*-*
4279 Mitsubishi D30V d30v-*-*
4281 * OBSOLETE configurations
4283 Gould PowerNode, NP1 np1-*-*, pn-*-*
4285 Configurations that have been declared obsolete will be commented out,
4286 but the code will be left in place. If there is no activity to revive
4287 these configurations before the next release of GDB, the sources will
4288 be permanently REMOVED.
4292 As a compatibility experiment, GDB's source files buildsym.h and
4293 buildsym.c have been converted to pure standard C, no longer
4294 containing any K&R compatibility code. We believe that all systems in
4295 use today either come with a standard C compiler, or have a GCC port
4296 available. If this is not true, please report the affected
4297 configuration to bug-gdb@gnu.org immediately. See the README file for
4298 information about getting a standard C compiler if you don't have one
4303 GDB now uses readline 2.2.
4305 * set extension-language
4307 You can now control the mapping between filename extensions and source
4308 languages by using the `set extension-language' command. For instance,
4309 you can ask GDB to treat .c files as C++ by saying
4310 set extension-language .c c++
4311 The command `info extensions' lists all of the recognized extensions
4312 and their associated languages.
4314 * Setting processor type for PowerPC and RS/6000
4316 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4317 you can use the `set processor' command to specify what variant of the
4318 PowerPC family you are debugging. The command
4322 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4323 following PowerPC and RS6000 variants:
4325 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4326 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4328 403GC IBM PowerPC 403GC
4329 505 Motorola PowerPC 505
4330 860 Motorola PowerPC 860 or 850
4331 601 Motorola PowerPC 601
4332 602 Motorola PowerPC 602
4333 603 Motorola/IBM PowerPC 603 or 603e
4334 604 Motorola PowerPC 604 or 604e
4335 750 Motorola/IBM PowerPC 750 or 750
4337 At the moment, this command just tells GDB what to name the
4338 special-purpose processor registers. Since almost all the affected
4339 registers are inaccessible to user-level programs, this command is
4340 only useful for remote debugging in its present form.
4344 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4345 more extensive support for HP-UX. Added features include shared
4346 library support, kernel threads and hardware watchpoints for 11.00,
4347 support for HP's ANSI C and C++ compilers, and a compatibility mode
4348 for xdb and dbx commands.
4352 HP's donation includes the new concept of catchpoints, which is a
4353 generalization of the old catch command. On HP-UX, it is now possible
4354 to catch exec, fork, and vfork, as well as library loading.
4356 This means that the existing catch command has changed; its first
4357 argument now specifies the type of catch to be set up. See the
4358 output of "help catch" for a list of catchpoint types.
4360 * Debugging across forks
4362 On HP-UX, you can choose which process to debug when a fork() happens
4367 HP has donated a curses-based terminal user interface (TUI). To get
4368 it, build with --enable-tui. Although this can be enabled for any
4369 configuration, at present it only works for native HP debugging.
4371 * GDB remote protocol additions
4373 A new protocol packet 'X' that writes binary data is now available.
4374 Default behavior is to try 'X', then drop back to 'M' if the stub
4375 fails to respond. The settable variable `remotebinarydownload'
4376 allows explicit control over the use of 'X'.
4378 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4379 full 64-bit address. The command
4381 set remoteaddresssize 32
4383 can be used to revert to the old behaviour. For existing remote stubs
4384 the change should not be noticed, as the additional address information
4387 In order to assist in debugging stubs, you may use the maintenance
4388 command `packet' to send any text string to the stub. For instance,
4390 maint packet heythere
4392 sends the packet "$heythere#<checksum>". Note that it is very easy to
4393 disrupt a debugging session by sending the wrong packet at the wrong
4396 The compare-sections command allows you to compare section data on the
4397 target to what is in the executable file without uploading or
4398 downloading, by comparing CRC checksums.
4400 * Tracing can collect general expressions
4402 You may now collect general expressions at tracepoints. This requires
4403 further additions to the target-side stub; see tracepoint.c and
4404 doc/agentexpr.texi for further details.
4406 * mask-address variable for Mips
4408 For Mips targets, you may control the zeroing of the upper 32 bits of
4409 a 64-bit address by entering `set mask-address on'. This is mainly
4410 of interest to users of embedded R4xxx and R5xxx processors.
4412 * Higher serial baud rates
4414 GDB's serial code now allows you to specify baud rates 57600, 115200,
4415 230400, and 460800 baud. (Note that your host system may not be able
4416 to achieve all of these rates.)
4420 The i960 configuration now includes an initial implementation of a
4421 builtin simulator, contributed by Jim Wilson.
4424 *** Changes in GDB-4.17:
4426 * New native configurations
4428 Alpha GNU/Linux alpha*-*-linux*
4429 Unixware 2.x i[3456]86-unixware2*
4430 Irix 6.x mips*-sgi-irix6*
4431 PowerPC GNU/Linux powerpc-*-linux*
4432 PowerPC Solaris powerpcle-*-solaris*
4433 Sparc GNU/Linux sparc-*-linux*
4434 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4438 Argonaut Risc Chip (ARC) arc-*-*
4439 Hitachi H8/300S h8300*-*-*
4440 Matsushita MN10200 w/simulator mn10200-*-*
4441 Matsushita MN10300 w/simulator mn10300-*-*
4442 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4443 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4444 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4445 Mitsubishi D10V w/simulator d10v-*-*
4446 Mitsubishi M32R/D w/simulator m32r-*-elf*
4447 Tsqware Sparclet sparclet-*-*
4448 NEC V850 w/simulator v850-*-*
4450 * New debugging protocols
4452 ARM with RDI protocol arm*-*-*
4453 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4454 DDB and LSI variants of PMON protocol mips*-*-*
4455 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4456 PowerPC with SDS protocol powerpc{,le}-*-eabi
4457 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4461 All configurations can now understand and use the DWARF 2 debugging
4462 format. The choice is automatic, if the symbol file contains DWARF 2
4467 GDB now includes basic Java language support. This support is
4468 only useful with Java compilers that produce native machine code.
4470 * solib-absolute-prefix and solib-search-path
4472 For SunOS and SVR4 shared libraries, you may now set the prefix for
4473 loading absolute shared library symbol files, and the search path for
4474 locating non-absolute shared library symbol files.
4476 * Live range splitting
4478 GDB can now effectively debug code for which GCC has performed live
4479 range splitting as part of its optimization. See gdb/doc/LRS for
4480 more details on the expected format of the stabs information.
4484 GDB's support for the GNU Hurd, including thread debugging, has been
4485 updated to work with current versions of the Hurd.
4489 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4490 instruction set. ARM GDB automatically detects when Thumb
4491 instructions are in use, and adjusts disassembly and backtracing
4496 GDB's MIPS target configurations now handle the MIP16 16-bit
4501 GDB now includes support for overlays; if an executable has been
4502 linked such that multiple sections are based at the same address, GDB
4503 will decide which section to use for symbolic info. You can choose to
4504 control the decision manually, using overlay commands, or implement
4505 additional target-side support and use "overlay load-target" to bring
4506 in the overlay mapping. Do "help overlay" for more detail.
4510 The command "info symbol <address>" displays information about
4511 the symbol at the specified address.
4515 The standard remote protocol now includes an extension that allows
4516 asynchronous collection and display of trace data. This requires
4517 extensive support in the target-side debugging stub. Tracing mode
4518 includes a new interaction mode in GDB and new commands: see the
4519 file tracepoint.c for more details.
4523 Configurations for embedded MIPS now include a simulator contributed
4524 by Cygnus Solutions. The simulator supports the instruction sets
4525 of most MIPS variants.
4529 Sparc configurations may now include the ERC32 simulator contributed
4530 by the European Space Agency. The simulator is not built into
4531 Sparc targets by default; configure with --enable-sim to include it.
4535 For target configurations that may include multiple variants of a
4536 basic architecture (such as MIPS and SH), you may now set the
4537 architecture explicitly. "set arch" sets, "info arch" lists
4538 the possible architectures.
4540 *** Changes in GDB-4.16:
4542 * New native configurations
4544 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4545 M68K NetBSD m68k-*-netbsd*
4546 PowerPC AIX 4.x powerpc-*-aix*
4547 PowerPC MacOS powerpc-*-macos*
4548 PowerPC Windows NT powerpcle-*-cygwin32
4549 RS/6000 AIX 4.x rs6000-*-aix4*
4553 ARM with RDP protocol arm-*-*
4554 I960 with MON960 i960-*-coff
4555 MIPS VxWorks mips*-*-vxworks*
4556 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4557 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4559 Matra Sparclet sparclet-*-*
4563 The powerpc-eabi configuration now includes the PSIM simulator,
4564 contributed by Andrew Cagney, with assistance from Mike Meissner.
4565 PSIM is a very elaborate model of the PowerPC, including not only
4566 basic instruction set execution, but also details of execution unit
4567 performance and I/O hardware. See sim/ppc/README for more details.
4571 GDB now works with Solaris 2.5.
4573 * Windows 95/NT native
4575 GDB will now work as a native debugger on Windows 95 and Windows NT.
4576 To build it from source, you must use the "gnu-win32" environment,
4577 which uses a DLL to emulate enough of Unix to run the GNU tools.
4578 Further information, binaries, and sources are available at
4579 ftp.cygnus.com, under pub/gnu-win32.
4581 * dont-repeat command
4583 If a user-defined command includes the command `dont-repeat', then the
4584 command will not be repeated if the user just types return. This is
4585 useful if the command is time-consuming to run, so that accidental
4586 extra keystrokes don't run the same command many times.
4588 * Send break instead of ^C
4590 The standard remote protocol now includes an option to send a break
4591 rather than a ^C to the target in order to interrupt it. By default,
4592 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4594 * Remote protocol timeout
4596 The standard remote protocol includes a new variable `remotetimeout'
4597 that allows you to set the number of seconds before GDB gives up trying
4598 to read from the target. The default value is 2.
4600 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4602 By default GDB will automatically keep track of objects as they are
4603 loaded and unloaded by the dynamic linker. By using the command `set
4604 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4605 when shared library events occur, thus allowing you to set breakpoints
4606 in shared libraries which are explicitly loaded by the inferior.
4608 Note this feature does not work on hpux8. On hpux9 you must link
4609 /usr/lib/end.o into your program. This feature should work
4610 automatically on hpux10.
4612 * Irix 5.x hardware watchpoint support
4614 Irix 5 configurations now support the use of hardware watchpoints.
4616 * Mips protocol "SYN garbage limit"
4618 When debugging a Mips target using the `target mips' protocol, you
4619 may set the number of characters that GDB will ignore by setting
4620 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4621 every character. The default value is 1050.
4623 * Recording and replaying remote debug sessions
4625 If you set `remotelogfile' to the name of a file, gdb will write to it
4626 a recording of a remote debug session. This recording may then be
4627 replayed back to gdb using "gdbreplay". See gdbserver/README for
4628 details. This is useful when you have a problem with GDB while doing
4629 remote debugging; you can make a recording of the session and send it
4630 to someone else, who can then recreate the problem.
4632 * Speedups for remote debugging
4634 GDB includes speedups for downloading and stepping MIPS systems using
4635 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4636 and more efficient S-record downloading.
4638 * Memory use reductions and statistics collection
4640 GDB now uses less memory and reports statistics about memory usage.
4641 Try the `maint print statistics' command, for example.
4643 *** Changes in GDB-4.15:
4645 * Psymtabs for XCOFF
4647 The symbol reader for AIX GDB now uses partial symbol tables. This
4648 can greatly improve startup time, especially for large executables.
4650 * Remote targets use caching
4652 Remote targets now use a data cache to speed up communication with the
4653 remote side. The data cache could lead to incorrect results because
4654 it doesn't know about volatile variables, thus making it impossible to
4655 debug targets which use memory mapped I/O devices. `set remotecache
4656 off' turns the the data cache off.
4658 * Remote targets may have threads
4660 The standard remote protocol now includes support for multiple threads
4661 in the target system, using new protocol commands 'H' and 'T'. See
4662 gdb/remote.c for details.
4666 If GDB is configured with `--enable-netrom', then it will include
4667 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4668 acts as though it is a bank of ROM on the target board, but you can
4669 write into it over the network. GDB's support consists only of
4670 support for fast loading into the emulated ROM; to debug, you must use
4671 another protocol, such as standard remote protocol. The usual
4672 sequence is something like
4674 target nrom <netrom-hostname>
4676 target remote <netrom-hostname>:1235
4680 GDB now includes support for the Apple Macintosh, as a host only. It
4681 may be run as either an MPW tool or as a standalone application, and
4682 it can debug through the serial port. All the usual GDB commands are
4683 available, but to the target command, you must supply "serial" as the
4684 device type instead of "/dev/ttyXX". See mpw-README in the main
4685 directory for more information on how to build. The MPW configuration
4686 scripts */mpw-config.in support only a few targets, and only the
4687 mips-idt-ecoff target has been tested.
4691 GDB configuration now uses autoconf. This is not user-visible,
4692 but does simplify configuration and building.
4696 GDB now supports hpux10.
4698 *** Changes in GDB-4.14:
4700 * New native configurations
4702 x86 FreeBSD i[345]86-*-freebsd
4703 x86 NetBSD i[345]86-*-netbsd
4704 NS32k NetBSD ns32k-*-netbsd
4705 Sparc NetBSD sparc-*-netbsd
4709 A29K VxWorks a29k-*-vxworks
4710 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4711 CPU32 EST-300 emulator m68*-*-est*
4712 PowerPC ELF powerpc-*-elf
4715 * Alpha OSF/1 support for procfs
4717 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4718 possible to attach to running processes. As the mounting of the /proc
4719 filesystem is optional on the Alpha, GDB automatically determines
4720 the availability of /proc during startup. This can lead to problems
4721 if /proc is unmounted after GDB has been started.
4723 * Arguments to user-defined commands
4725 User commands may accept up to 10 arguments separated by whitespace.
4726 Arguments are accessed within the user command via $arg0..$arg9. A
4729 print $arg0 + $arg1 + $arg2
4731 To execute the command use:
4734 Defines the command "adder" which prints the sum of its three arguments.
4735 Note the arguments are text substitutions, so they may reference variables,
4736 use complex expressions, or even perform inferior function calls.
4738 * New `if' and `while' commands
4740 This makes it possible to write more sophisticated user-defined
4741 commands. Both commands take a single argument, which is the
4742 expression to evaluate, and must be followed by the commands to
4743 execute, one per line, if the expression is nonzero, the list being
4744 terminated by the word `end'. The `if' command list may include an
4745 `else' word, which causes the following commands to be executed only
4746 if the expression is zero.
4748 * Fortran source language mode
4750 GDB now includes partial support for Fortran 77. It will recognize
4751 Fortran programs and can evaluate a subset of Fortran expressions, but
4752 variables and functions may not be handled correctly. GDB will work
4753 with G77, but does not yet know much about symbols emitted by other
4756 * Better HPUX support
4758 Most debugging facilities now work on dynamic executables for HPPAs
4759 running hpux9 or later. You can attach to running dynamically linked
4760 processes, but by default the dynamic libraries will be read-only, so
4761 for instance you won't be able to put breakpoints in them. To change
4762 that behavior do the following before running the program:
4768 This will cause the libraries to be mapped private and read-write.
4769 To revert to the normal behavior, do this:
4775 You cannot set breakpoints or examine data in the library until after
4776 the library is loaded if the function/data symbols do not have
4779 GDB can now also read debug symbols produced by the HP C compiler on
4780 HPPAs (sorry, no C++, Fortran or 68k support).
4782 * Target byte order now dynamically selectable
4784 You can choose which byte order to use with a target system, via the
4785 commands "set endian big" and "set endian little", and you can see the
4786 current setting by using "show endian". You can also give the command
4787 "set endian auto", in which case GDB will use the byte order
4788 associated with the executable. Currently, only embedded MIPS
4789 configurations support dynamic selection of target byte order.
4791 * New DOS host serial code
4793 This version uses DPMI interrupts to handle buffered I/O, so you
4794 no longer need to run asynctsr when debugging boards connected to
4797 *** Changes in GDB-4.13:
4799 * New "complete" command
4801 This lists all the possible completions for the rest of the line, if it
4802 were to be given as a command itself. This is intended for use by emacs.
4804 * Trailing space optional in prompt
4806 "set prompt" no longer adds a space for you after the prompt you set. This
4807 allows you to set a prompt which ends in a space or one that does not.
4809 * Breakpoint hit counts
4811 "info break" now displays a count of the number of times the breakpoint
4812 has been hit. This is especially useful in conjunction with "ignore"; you
4813 can ignore a large number of breakpoint hits, look at the breakpoint info
4814 to see how many times the breakpoint was hit, then run again, ignoring one
4815 less than that number, and this will get you quickly to the last hit of
4818 * Ability to stop printing at NULL character
4820 "set print null-stop" will cause GDB to stop printing the characters of
4821 an array when the first NULL is encountered. This is useful when large
4822 arrays actually contain only short strings.
4824 * Shared library breakpoints
4826 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4827 breakpoints in shared libraries before the executable is run.
4829 * Hardware watchpoints
4831 There is a new hardware breakpoint for the watch command for sparclite
4832 targets. See gdb/sparclite/hw_breakpoint.note.
4834 Hardware watchpoints are also now supported under GNU/Linux.
4838 Annotations have been added. These are for use with graphical interfaces,
4839 and are still experimental. Currently only gdba.el uses these.
4841 * Improved Irix 5 support
4843 GDB now works properly with Irix 5.2.
4845 * Improved HPPA support
4847 GDB now works properly with the latest GCC and GAS.
4849 * New native configurations
4851 Sequent PTX4 i[34]86-sequent-ptx4
4852 HPPA running OSF/1 hppa*-*-osf*
4853 Atari TT running SVR4 m68*-*-sysv4*
4854 RS/6000 LynxOS rs6000-*-lynxos*
4858 OS/9000 i[34]86-*-os9k
4859 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4862 * Hitachi SH7000 and E7000-PC ICE support
4864 There is now support for communicating with the Hitachi E7000-PC ICE.
4865 This is available automatically when GDB is configured for the SH.
4869 As usual, a variety of small fixes and improvements, both generic
4870 and configuration-specific. See the ChangeLog for more detail.
4872 *** Changes in GDB-4.12:
4874 * Irix 5 is now supported
4878 GDB-4.12 on the HPPA has a number of changes which make it unable
4879 to debug the output from the currently released versions of GCC and
4880 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4881 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4882 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4885 *** Changes in GDB-4.11:
4887 * User visible changes:
4891 The "set remotedebug" option is now consistent between the mips remote
4892 target, remote targets using the gdb-specific protocol, UDI (AMD's
4893 debug protocol for the 29k) and the 88k bug monitor. It is now an
4894 integer specifying a debug level (normally 0 or 1, but 2 means more
4895 debugging info for the mips target).
4897 * DEC Alpha native support
4899 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4900 debug info, but GDB works fairly well with the DEC compiler and should
4901 work with a future GCC release. See the README file for a few
4902 Alpha-specific notes.
4904 * Preliminary thread implementation
4906 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4908 * LynxOS native and target support for 386
4910 This release has been hosted on LynxOS 2.2, and also can be configured
4911 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4914 * Improvements in C++ mangling/demangling.
4916 This release has much better g++ debugging, specifically in name
4917 mangling/demangling, virtual function calls, print virtual table,
4918 call methods, ...etc.
4920 *** Changes in GDB-4.10:
4922 * User visible changes:
4924 Remote debugging using the GDB-specific (`target remote') protocol now
4925 supports the `load' command. This is only useful if you have some
4926 other way of getting the stub to the target system, and you can put it
4927 somewhere in memory where it won't get clobbered by the download.
4929 Filename completion now works.
4931 When run under emacs mode, the "info line" command now causes the
4932 arrow to point to the line specified. Also, "info line" prints
4933 addresses in symbolic form (as well as hex).
4935 All vxworks based targets now support a user settable option, called
4936 vxworks-timeout. This option represents the number of seconds gdb
4937 should wait for responses to rpc's. You might want to use this if
4938 your vxworks target is, perhaps, a slow software simulator or happens
4939 to be on the far side of a thin network line.
4943 This release contains support for using a DEC alpha as a GDB host for
4944 cross debugging. Native alpha debugging is not supported yet.
4947 *** Changes in GDB-4.9:
4951 This is the first GDB release which is accompanied by a matching testsuite.
4952 The testsuite requires installation of dejagnu, which should be available
4953 via ftp from most sites that carry GNU software.
4957 'Cfront' style demangling has had its name changed to 'ARM' style, to
4958 emphasize that it was written from the specifications in the C++ Annotated
4959 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4960 disclaimers, it still generated too much confusion with users attempting to
4961 use gdb with AT&T cfront.
4965 GDB now uses a standard remote interface to a simulator library.
4966 So far, the library contains simulators for the Zilog Z8001/2, the
4967 Hitachi H8/300, H8/500 and Super-H.
4969 * New targets supported
4971 H8/300 simulator h8300-hitachi-hms or h8300hms
4972 H8/500 simulator h8500-hitachi-hms or h8500hms
4973 SH simulator sh-hitachi-hms or sh
4974 Z8000 simulator z8k-zilog-none or z8ksim
4975 IDT MIPS board over serial line mips-idt-ecoff
4977 Cross-debugging to GO32 targets is supported. It requires a custom
4978 version of the i386-stub.c module which is integrated with the
4979 GO32 memory extender.
4981 * New remote protocols
4983 MIPS remote debugging protocol.
4985 * New source languages supported
4987 This version includes preliminary support for Chill, a Pascal like language
4988 used by telecommunications companies. Chill support is also being integrated
4989 into the GNU compiler, but we don't know when it will be publically available.
4992 *** Changes in GDB-4.8:
4994 * HP Precision Architecture supported
4996 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4997 version of this support was available as a set of patches from the
4998 University of Utah. GDB does not support debugging of programs
4999 compiled with the HP compiler, because HP will not document their file
5000 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5001 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5003 Many problems in the preliminary version have been fixed.
5005 * Faster and better demangling
5007 We have improved template demangling and fixed numerous bugs in the GNU style
5008 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5009 character types (wchar_t) are now supported. Demangling of each symbol is now
5010 only done once, and is cached when the symbol table for a file is read in.
5011 This results in a small increase in memory usage for C programs, a moderate
5012 increase in memory usage for C++ programs, and a fantastic speedup in
5015 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5016 from the specifications in the Annotated Reference Manual, which AT&T's
5017 compiler does not actually implement.
5019 * G++ multiple inheritance compiler problem
5021 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5022 inheritance lattices was reworked to properly discover ambiguities. We
5023 recently found an example which causes this new algorithm to fail in a
5024 very subtle way, producing bad debug information for those classes.
5025 The file 'gcc.patch' (in this directory) can be applied to gcc to
5026 circumvent the problem. A future GCC release will contain a complete
5029 The previous G++ debug info problem (mentioned below for the gdb-4.7
5030 release) is fixed in gcc version 2.3.2.
5032 * Improved configure script
5034 The `configure' script will now attempt to guess your system type if
5035 you don't supply a host system type. The old scheme of supplying a
5036 host system triplet is preferable over using this. All the magic is
5037 done in the new `config.guess' script. Examine it for details.
5039 We have also brought our configure script much more in line with the FSF's
5040 version. It now supports the --with-xxx options. In particular,
5041 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5042 The resulting GDB will not be able to read arbitrary object file formats --
5043 only the format ``expected'' to be used on the configured target system.
5044 We hope to make this the default in a future release.
5046 * Documentation improvements
5048 There's new internal documentation on how to modify GDB, and how to
5049 produce clean changes to the code. We implore people to read it
5050 before submitting changes.
5052 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5053 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5054 `info' files are also provided. To build `info' files from scratch,
5055 you will need the latest `makeinfo' release, which will be available in
5056 a future texinfo-X.Y release.
5058 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5059 We're not sure exactly which versions have this problem, but it has
5060 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5061 or better. If that isn't possible, there is a patch in
5062 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5063 around this problem.
5067 GDB now supports array constants that can be used in expressions typed in by
5068 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5069 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5072 The new directory `gdb/sparclite' contains a program that demonstrates
5073 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5075 * New native hosts supported
5077 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5078 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5080 * New targets supported
5082 AMD 29k family via UDI a29k-amd-udi or udi29k
5084 * New file formats supported
5086 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5087 HPUX core files, and SCO 3.2v2 core files.
5091 Attaching to processes now works again; thanks for the many bug reports.
5093 We have also stomped on a bunch of core dumps caused by
5094 printf_filtered("%s") problems.
5096 We eliminated a copyright problem on the rpc and ptrace header files
5097 for VxWorks, which was discovered at the last minute during the 4.7
5098 release. You should now be able to build a VxWorks GDB.
5100 You can now interrupt gdb while an attached process is running. This
5101 will cause the attached process to stop, and give control back to GDB.
5103 We fixed problems caused by using too many file descriptors
5104 for reading symbols from object files and libraries. This was
5105 especially a problem for programs that used many (~100) shared
5108 The `step' command now only enters a subroutine if there is line number
5109 information for the subroutine. Otherwise it acts like the `next'
5110 command. Previously, `step' would enter subroutines if there was
5111 any debugging information about the routine. This avoids problems
5112 when using `cc -g1' on MIPS machines.
5114 * Internal improvements
5116 GDB's internal interfaces have been improved to make it easier to support
5117 debugging of multiple languages in the future.
5119 GDB now uses a common structure for symbol information internally.
5120 Minimal symbols (derived from linkage symbols in object files), partial
5121 symbols (from a quick scan of debug information), and full symbols
5122 contain a common subset of information, making it easier to write
5123 shared code that handles any of them.
5125 * New command line options
5127 We now accept --silent as an alias for --quiet.
5131 The memory-mapped-malloc library is now licensed under the GNU Library
5132 General Public License.
5134 *** Changes in GDB-4.7:
5136 * Host/native/target split
5138 GDB has had some major internal surgery to untangle the support for
5139 hosts and remote targets. Now, when you configure GDB for a remote
5140 target, it will no longer load in all of the support for debugging
5141 local programs on the host. When fully completed and tested, this will
5142 ensure that arbitrary host/target combinations are possible.
5144 The primary conceptual shift is to separate the non-portable code in
5145 GDB into three categories. Host specific code is required any time GDB
5146 is compiled on that host, regardless of the target. Target specific
5147 code relates to the peculiarities of the target, but can be compiled on
5148 any host. Native specific code is everything else: it can only be
5149 built when the host and target are the same system. Child process
5150 handling and core file support are two common `native' examples.
5152 GDB's use of /proc for controlling Unix child processes is now cleaner.
5153 It has been split out into a single module under the `target_ops' vector,
5154 plus two native-dependent functions for each system that uses /proc.
5156 * New hosts supported
5158 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5159 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5160 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5162 * New targets supported
5164 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5165 68030 and CPU32 m68030-*-*, m68332-*-*
5167 * New native hosts supported
5169 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5170 (386bsd is not well tested yet)
5171 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5173 * New file formats supported
5175 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5176 supports reading of `a.out.adobe' object files, which are an a.out
5177 format extended with minimal information about multiple sections.
5181 `show copying' is the same as the old `info copying'.
5182 `show warranty' is the same as `info warrantee'.
5183 These were renamed for consistency. The old commands continue to work.
5185 `info handle' is a new alias for `info signals'.
5187 You can now define pre-command hooks, which attach arbitrary command
5188 scripts to any command. The commands in the hook will be executed
5189 prior to the user's command. You can also create a hook which will be
5190 executed whenever the program stops. See gdb.texinfo.
5194 We now deal with Cfront style name mangling, and can even extract type
5195 info from mangled symbols. GDB can automatically figure out which
5196 symbol mangling style your C++ compiler uses.
5198 Calling of methods and virtual functions has been improved as well.
5202 The crash that occured when debugging Sun Ansi-C compiled binaries is
5203 fixed. This was due to mishandling of the extra N_SO stabs output
5206 We also finally got Ultrix 4.2 running in house, and fixed core file
5207 support, with help from a dozen people on the net.
5209 John M. Farrell discovered that the reason that single-stepping was so
5210 slow on all of the Mips based platforms (primarily SGI and DEC) was
5211 that we were trying to demangle and lookup a symbol used for internal
5212 purposes on every instruction that was being stepped through. Changing
5213 the name of that symbol so that it couldn't be mistaken for a C++
5214 mangled symbol sped things up a great deal.
5216 Rich Pixley sped up symbol lookups in general by getting much smarter
5217 about when C++ symbol mangling is necessary. This should make symbol
5218 completion (TAB on the command line) much faster. It's not as fast as
5219 we'd like, but it's significantly faster than gdb-4.6.
5223 A new user controllable variable 'call_scratch_address' can
5224 specify the location of a scratch area to be used when GDB
5225 calls a function in the target. This is necessary because the
5226 usual method of putting the scratch area on the stack does not work
5227 in systems that have separate instruction and data spaces.
5229 We integrated changes to support the 29k UDI (Universal Debugger
5230 Interface), but discovered at the last minute that we didn't have all
5231 of the appropriate copyright paperwork. We are working with AMD to
5232 resolve this, and hope to have it available soon.
5236 We have sped up the remote serial line protocol, especially for targets
5237 with lots of registers. It now supports a new `expedited status' ('T')
5238 message which can be used in place of the existing 'S' status message.
5239 This allows the remote stub to send only the registers that GDB
5240 needs to make a quick decision about single-stepping or conditional
5241 breakpoints, eliminating the need to fetch the entire register set for
5242 each instruction being stepped through.
5244 The GDB remote serial protocol now implements a write-through cache for
5245 registers, only re-reading the registers if the target has run.
5247 There is also a new remote serial stub for SPARC processors. You can
5248 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5249 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5250 processor with a serial port.
5254 Configure.in files have become much easier to read and modify. A new
5255 `table driven' format makes it more obvious what configurations are
5256 supported, and what files each one uses.
5260 There is a new opcodes library which will eventually contain all of the
5261 disassembly routines and opcode tables. At present, it only contains
5262 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5263 disassembler (binutils/objdump) to share these routines.
5265 The libiberty library is now copylefted under the GNU Library General
5266 Public License. This allows more liberal use, and was done so libg++
5267 can use it. This makes no difference to GDB, since the Library License
5268 grants all the rights from the General Public License.
5272 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5273 reference to the stabs symbol info used by the debugger. It is (as far
5274 as we know) the only published document on this fascinating topic. We
5275 encourage you to read it, compare it to the stabs information on your
5276 system, and send improvements on the document in general (to
5277 bug-gdb@prep.ai.mit.edu).
5279 And, of course, many bugs have been fixed.
5282 *** Changes in GDB-4.6:
5284 * Better support for C++ function names
5286 GDB now accepts as input the "demangled form" of C++ overloaded function
5287 names and member function names, and can do command completion on such names
5288 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5289 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5290 Make use of command completion, it is your friend.
5292 GDB also now accepts a variety of C++ mangled symbol formats. They are
5293 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5294 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5295 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5296 for the list of formats.
5298 * G++ symbol mangling problem
5300 Recent versions of gcc have a bug in how they emit debugging information for
5301 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5302 directory) can be applied to gcc to fix the problem. Alternatively, if you
5303 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5304 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5305 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5308 * New 'maintenance' command
5310 All of the commands related to hacking GDB internals have been moved out of
5311 the main command set, and now live behind the 'maintenance' command. This
5312 can also be abbreviated as 'mt'. The following changes were made:
5314 dump-me -> maintenance dump-me
5315 info all-breakpoints -> maintenance info breakpoints
5316 printmsyms -> maintenance print msyms
5317 printobjfiles -> maintenance print objfiles
5318 printpsyms -> maintenance print psymbols
5319 printsyms -> maintenance print symbols
5321 The following commands are new:
5323 maintenance demangle Call internal GDB demangler routine to
5324 demangle a C++ link name and prints the result.
5325 maintenance print type Print a type chain for a given symbol
5327 * Change to .gdbinit file processing
5329 We now read the $HOME/.gdbinit file before processing the argv arguments
5330 (e.g. reading symbol files or core files). This allows global parameters to
5331 be set, which will apply during the symbol reading. The ./.gdbinit is still
5332 read after argv processing.
5334 * New hosts supported
5336 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5338 GNU/Linux support i386-unknown-linux or linux
5340 We are also including code to support the HP/PA running BSD and HPUX. This
5341 is almost guaranteed not to work, as we didn't have time to test or build it
5342 for this release. We are including it so that the more adventurous (or
5343 masochistic) of you can play with it. We also had major problems with the
5344 fact that the compiler that we got from HP doesn't support the -g option.
5347 * New targets supported
5349 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5351 * More smarts about finding #include files
5353 GDB now remembers the compilation directory for all include files, and for
5354 all files from which C is generated (like yacc and lex sources). This
5355 greatly improves GDB's ability to find yacc/lex sources, and include files,
5356 especially if you are debugging your program from a directory different from
5357 the one that contains your sources.
5359 We also fixed a bug which caused difficulty with listing and setting
5360 breakpoints in include files which contain C code. (In the past, you had to
5361 try twice in order to list an include file that you hadn't looked at before.)
5363 * Interesting infernals change
5365 GDB now deals with arbitrary numbers of sections, where the symbols for each
5366 section must be relocated relative to that section's landing place in the
5367 target's address space. This work was needed to support ELF with embedded
5368 stabs used by Solaris-2.0.
5370 * Bug fixes (of course!)
5372 There have been loads of fixes for the following things:
5373 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5374 i960, stabs, DOS(GO32), procfs, etc...
5376 See the ChangeLog for details.
5378 *** Changes in GDB-4.5:
5380 * New machines supported (host and target)
5382 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5384 SGI Irix-4.x mips-sgi-irix4 or iris4
5386 * New malloc package
5388 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5389 Mmalloc is capable of handling mutiple heaps of memory. It is also
5390 capable of saving a heap to a file, and then mapping it back in later.
5391 This can be used to greatly speedup the startup of GDB by using a
5392 pre-parsed symbol table which lives in a mmalloc managed heap. For
5393 more details, please read mmalloc/mmalloc.texi.
5397 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5398 'help info proc' for details.
5400 * MIPS ecoff symbol table format
5402 The code that reads MIPS symbol table format is now supported on all hosts.
5403 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5406 * File name changes for MS-DOS
5408 Many files in the config directories have been renamed to make it easier to
5409 support GDB on MS-DOSe systems (which have very restrictive file name
5410 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5411 environment) is close to working but has some remaining problems. Note
5412 that debugging of DOS programs is not supported, due to limitations
5413 in the ``operating system'', but it can be used to host cross-debugging.
5415 * Cross byte order fixes
5417 Many fixes have been made to support cross debugging of Sparc and MIPS
5418 targets from hosts whose byte order differs.
5420 * New -mapped and -readnow options
5422 If memory-mapped files are available on your system through the 'mmap'
5423 system call, you can use the -mapped option on the `file' or
5424 `symbol-file' commands to cause GDB to write the symbols from your
5425 program into a reusable file. If the program you are debugging is
5426 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5427 Future GDB debugging sessions will notice the presence of this file,
5428 and will quickly map in symbol information from it, rather than reading
5429 the symbol table from the executable program. Using the '-mapped'
5430 option in a GDB `file' or `symbol-file' command has the same effect as
5431 starting GDB with the '-mapped' command-line option.
5433 You can cause GDB to read the entire symbol table immediately by using
5434 the '-readnow' option with any of the commands that load symbol table
5435 information (or on the GDB command line). This makes the command
5436 slower, but makes future operations faster.
5438 The -mapped and -readnow options are typically combined in order to
5439 build a `fred.syms' file that contains complete symbol information.
5440 A simple GDB invocation to do nothing but build a `.syms' file for future
5443 gdb -batch -nx -mapped -readnow programname
5445 The `.syms' file is specific to the host machine on which GDB is run.
5446 It holds an exact image of GDB's internal symbol table. It cannot be
5447 shared across multiple host platforms.
5449 * longjmp() handling
5451 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5452 siglongjmp() without losing control. This feature has not yet been ported to
5453 all systems. It currently works on many 386 platforms, all MIPS-based
5454 platforms (SGI, DECstation, etc), and Sun3/4.
5458 Preliminary work has been put in to support the new Solaris OS from Sun. At
5459 this time, it can control and debug processes, but it is not capable of
5464 As always, many many bug fixes. The major areas were with g++, and mipsread.
5465 People using the MIPS-based platforms should experience fewer mysterious
5466 crashes and trashed symbol tables.
5468 *** Changes in GDB-4.4:
5470 * New machines supported (host and target)
5472 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5474 BSD Reno on Vax vax-dec-bsd
5475 Ultrix on Vax vax-dec-ultrix
5477 * New machines supported (target)
5479 AMD 29000 embedded, using EBMON a29k-none-none
5483 GDB continues to improve its handling of C++. `References' work better.
5484 The demangler has also been improved, and now deals with symbols mangled as
5485 per the Annotated C++ Reference Guide.
5487 GDB also now handles `stabs' symbol information embedded in MIPS
5488 `ecoff' symbol tables. Since the ecoff format was not easily
5489 extensible to handle new languages such as C++, this appeared to be a
5490 good way to put C++ debugging info into MIPS binaries. This option
5491 will be supported in the GNU C compiler, version 2, when it is
5494 * New features for SVR4
5496 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5497 shared libraries. Debugging dynamically linked programs should present
5498 only minor differences from debugging statically linked programs.
5500 The `info proc' command will print out information about any process
5501 on an SVR4 system (including the one you are debugging). At the moment,
5502 it prints the address mappings of the process.
5504 If you bring up GDB on another SVR4 system, please send mail to
5505 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5507 * Better dynamic linking support in SunOS
5509 Reading symbols from shared libraries which contain debugging symbols
5510 now works properly. However, there remain issues such as automatic
5511 skipping of `transfer vector' code during function calls, which
5512 make it harder to debug code in a shared library, than to debug the
5513 same code linked statically.
5517 GDB is now using the latest `getopt' routines from the FSF. This
5518 version accepts the -- prefix for options with long names. GDB will
5519 continue to accept the old forms (-option and +option) as well.
5520 Various single letter abbreviations for options have been explicity
5521 added to the option table so that they won't get overshadowed in the
5522 future by other options that begin with the same letter.
5526 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5527 Many assorted bugs have been handled. Many more remain to be handled.
5528 See the various ChangeLog files (primarily in gdb and bfd) for details.
5531 *** Changes in GDB-4.3:
5533 * New machines supported (host and target)
5535 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5536 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5537 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5539 * Almost SCO Unix support
5541 We had hoped to support:
5542 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5543 (except for core file support), but we discovered very late in the release
5544 that it has problems with process groups that render gdb unusable. Sorry
5545 about that. I encourage people to fix it and post the fixes.
5547 * Preliminary ELF and DWARF support
5549 GDB can read ELF object files on System V Release 4, and can handle
5550 debugging records for C, in DWARF format, in ELF files. This support
5551 is preliminary. If you bring up GDB on another SVR4 system, please
5552 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5557 GDB now uses the latest `readline' library. One user-visible change
5558 is that two tabs will list possible command completions, which previously
5559 required typing M-? (meta-question mark, or ESC ?).
5563 The `stepi' bug that many of you noticed has been squashed.
5564 Many bugs in C++ have been handled. Many more remain to be handled.
5565 See the various ChangeLog files (primarily in gdb and bfd) for details.
5567 * State of the MIPS world (in case you wondered):
5569 GDB can understand the symbol tables emitted by the compilers
5570 supplied by most vendors of MIPS-based machines, including DEC. These
5571 symbol tables are in a format that essentially nobody else uses.
5573 Some versions of gcc come with an assembler post-processor called
5574 mips-tfile. This program is required if you want to do source-level
5575 debugging of gcc-compiled programs. I believe FSF does not ship
5576 mips-tfile with gcc version 1, but it will eventually come with gcc
5579 Debugging of g++ output remains a problem. g++ version 1.xx does not
5580 really support it at all. (If you're lucky, you should be able to get
5581 line numbers and stack traces to work, but no parameters or local
5582 variables.) With some work it should be possible to improve the
5585 When gcc version 2 is released, you will have somewhat better luck.
5586 However, even then you will get confusing results for inheritance and
5589 We will eventually provide full debugging of g++ output on
5590 DECstations. This will probably involve some kind of stabs-in-ecoff
5591 encapulation, but the details have not been worked out yet.
5594 *** Changes in GDB-4.2:
5596 * Improved configuration
5598 Only one copy of `configure' exists now, and it is not self-modifying.
5599 Porting BFD is simpler.
5603 The `step' and `next' commands now only stop at the first instruction
5604 of a source line. This prevents the multiple stops that used to occur
5605 in switch statements, for-loops, etc. `Step' continues to stop if a
5606 function that has debugging information is called within the line.
5610 Lots of small bugs fixed. More remain.
5612 * New host supported (not target)
5614 Intel 386 PC clone running Mach i386-none-mach
5617 *** Changes in GDB-4.1:
5619 * Multiple source language support
5621 GDB now has internal scaffolding to handle several source languages.
5622 It determines the type of each source file from its filename extension,
5623 and will switch expression parsing and number formatting to match the
5624 language of the function in the currently selected stack frame.
5625 You can also specifically set the language to be used, with
5626 `set language c' or `set language modula-2'.
5630 GDB now has preliminary support for the GNU Modula-2 compiler,
5631 currently under development at the State University of New York at
5632 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5633 continue through the fall of 1991 and into 1992.
5635 Other Modula-2 compilers are currently not supported, and attempting to
5636 debug programs compiled with them will likely result in an error as the
5637 symbol table is read. Feel free to work on it, though!
5639 There are hooks in GDB for strict type checking and range checking,
5640 in the `Modula-2 philosophy', but they do not currently work.
5644 GDB can now write to executable and core files (e.g. patch
5645 a variable's value). You must turn this switch on, specify
5646 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5647 by assigning a new value to a variable. Modifications take
5650 * Automatic SunOS shared library reading
5652 When you run your program, GDB automatically determines where its
5653 shared libraries (if any) have been loaded, and reads their symbols.
5654 The `share' command is no longer needed. This also works when
5655 examining core files.
5659 You can specify the number of lines that the `list' command shows.
5662 * New machines supported (host and target)
5664 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5665 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5666 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5668 * New hosts supported (not targets)
5670 IBM RT/PC: romp-ibm-aix or rtpc
5672 * New targets supported (not hosts)
5674 AMD 29000 embedded with COFF a29k-none-coff
5675 AMD 29000 embedded with a.out a29k-none-aout
5676 Ultracomputer remote kernel debug a29k-nyu-kern
5678 * New remote interfaces
5684 *** Changes in GDB-4.0:
5688 Wide output is wrapped at good places to make the output more readable.
5690 Gdb now supports cross-debugging from a host machine of one type to a
5691 target machine of another type. Communication with the target system
5692 is over serial lines. The ``target'' command handles connecting to the
5693 remote system; the ``load'' command will download a program into the
5694 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5695 also supports debugging of realtime processes running under VxWorks,
5696 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5697 stub on the target system.
5699 New CPUs supported include the AMD 29000 and Intel 960.
5701 GDB now reads object files and symbol tables via a ``binary file''
5702 library, which allows a single copy of GDB to debug programs of multiple
5703 object file types such as a.out and coff.
5705 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5706 refcard.dvi and refcard.ps are available to format it).
5709 * Control-Variable user interface simplified
5711 All variables that control the operation of the debugger can be set
5712 by the ``set'' command, and displayed by the ``show'' command.
5714 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5715 ``Show prompt'' produces the response:
5716 Gdb's prompt is new-gdb=>.
5718 What follows are the NEW set commands. The command ``help set'' will
5719 print a complete list of old and new set commands. ``help set FOO''
5720 will give a longer description of the variable FOO. ``show'' will show
5721 all of the variable descriptions and their current settings.
5723 confirm on/off: Enables warning questions for operations that are
5724 hard to recover from, e.g. rerunning the program while
5725 it is already running. Default is ON.
5727 editing on/off: Enables EMACS style command line editing
5728 of input. Previous lines can be recalled with
5729 control-P, the current line can be edited with control-B,
5730 you can search for commands with control-R, etc.
5733 history filename NAME: NAME is where the gdb command history
5734 will be stored. The default is .gdb_history,
5735 or the value of the environment variable
5738 history size N: The size, in commands, of the command history. The
5739 default is 256, or the value of the environment variable
5742 history save on/off: If this value is set to ON, the history file will
5743 be saved after exiting gdb. If set to OFF, the
5744 file will not be saved. The default is OFF.
5746 history expansion on/off: If this value is set to ON, then csh-like
5747 history expansion will be performed on
5748 command line input. The default is OFF.
5750 radix N: Sets the default radix for input and output. It can be set
5751 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5752 in the current radix, so "set radix 10" is always a no-op.
5754 height N: This integer value is the number of lines on a page. Default
5755 is 24, the current `stty rows'' setting, or the ``li#''
5756 setting from the termcap entry matching the environment
5759 width N: This integer value is the number of characters on a line.
5760 Default is 80, the current `stty cols'' setting, or the ``co#''
5761 setting from the termcap entry matching the environment
5764 Note: ``set screensize'' is obsolete. Use ``set height'' and
5765 ``set width'' instead.
5767 print address on/off: Print memory addresses in various command displays,
5768 such as stack traces and structure values. Gdb looks
5769 more ``symbolic'' if you turn this off; it looks more
5770 ``machine level'' with it on. Default is ON.
5772 print array on/off: Prettyprint arrays. New convenient format! Default
5775 print demangle on/off: Print C++ symbols in "source" form if on,
5778 print asm-demangle on/off: Same, for assembler level printouts
5781 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5784 * Support for Epoch Environment.
5786 The epoch environment is a version of Emacs v18 with windowing. One
5787 new command, ``inspect'', is identical to ``print'', except that if you
5788 are running in the epoch environment, the value is printed in its own
5792 * Support for Shared Libraries
5794 GDB can now debug programs and core files that use SunOS shared libraries.
5795 Symbols from a shared library cannot be referenced
5796 before the shared library has been linked with the program (this
5797 happens after you type ``run'' and before the function main() is entered).
5798 At any time after this linking (including when examining core files
5799 from dynamically linked programs), gdb reads the symbols from each
5800 shared library when you type the ``sharedlibrary'' command.
5801 It can be abbreviated ``share''.
5803 sharedlibrary REGEXP: Load shared object library symbols for files
5804 matching a unix regular expression. No argument
5805 indicates to load symbols for all shared libraries.
5807 info sharedlibrary: Status of loaded shared libraries.
5812 A watchpoint stops execution of a program whenever the value of an
5813 expression changes. Checking for this slows down execution
5814 tremendously whenever you are in the scope of the expression, but is
5815 quite useful for catching tough ``bit-spreader'' or pointer misuse
5816 problems. Some machines such as the 386 have hardware for doing this
5817 more quickly, and future versions of gdb will use this hardware.
5819 watch EXP: Set a watchpoint (breakpoint) for an expression.
5821 info watchpoints: Information about your watchpoints.
5823 delete N: Deletes watchpoint number N (same as breakpoints).
5824 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5825 enable N: Re-enables watchpoint number N (same as breakpoints).
5828 * C++ multiple inheritance
5830 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5833 * C++ exception handling
5835 Gdb now supports limited C++ exception handling. Besides the existing
5836 ability to breakpoint on an exception handler, gdb can breakpoint on
5837 the raising of an exception (before the stack is peeled back to the
5840 catch FOO: If there is a FOO exception handler in the dynamic scope,
5841 set a breakpoint to catch exceptions which may be raised there.
5842 Multiple exceptions (``catch foo bar baz'') may be caught.
5844 info catch: Lists all exceptions which may be caught in the
5845 current stack frame.
5848 * Minor command changes
5850 The command ``call func (arg, arg, ...)'' now acts like the print
5851 command, except it does not print or save a value if the function's result
5852 is void. This is similar to dbx usage.
5854 The ``up'' and ``down'' commands now always print the frame they end up
5855 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5856 frames without printing.
5858 * New directory command
5860 'dir' now adds directories to the FRONT of the source search path.
5861 The path starts off empty. Source files that contain debug information
5862 about the directory in which they were compiled can be found even
5863 with an empty path; Sun CC and GCC include this information. If GDB can't
5864 find your source file in the current directory, type "dir .".
5866 * Configuring GDB for compilation
5868 For normal use, type ``./configure host''. See README or gdb.texinfo
5871 GDB now handles cross debugging. If you are remotely debugging between
5872 two different machines, type ``./configure host -target=targ''.
5873 Host is the machine where GDB will run; targ is the machine
5874 where the program that you are debugging will run.