1 What has changed in GDB?
2 (Organized release by release)
6 New events which are triggered when GDB modifies the state of the
9 ** gdb.events.inferior_call_pre: Function call is about to be made.
10 ** gdb.events.inferior_call_post: Function call has just been made.
11 ** gdb.events.memory_changed: A memory location has been altered.
12 ** gdb.events.register_changed: A register has been altered.
14 *** Changes since GDB 7.8
16 * GDB now supports hardware watchpoints on x86 GNU Hurd.
20 ** You can now access frame registers from Python scripts.
21 ** New attribute 'producer' for gdb.Symtab objects.
22 ** gdb.Objfile objects have a new attribute "progspace",
23 which is the gdb.Progspace object of the containing program space.
24 ** gdb.Objfile objects have a new attribute "owner".
25 ** gdb.Objfile objects have a new attribute "build_id",
26 which is the build ID generated when the file was built.
27 ** gdb.Objfile objects have a new method "add_separate_debug_file".
28 ** A new event "gdb.clear_objfiles" has been added, triggered when
29 selecting a new file to debug.
30 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
31 ** New function gdb.lookup_objfile.
33 * New Python-based convenience functions:
35 ** $_caller_is(name [, number_of_frames])
36 ** $_caller_matches(regexp [, number_of_frames])
37 ** $_any_caller_is(name [, number_of_frames])
38 ** $_any_caller_matches(regexp [, number_of_frames])
40 * GDB now supports the compilation and injection of source code into
41 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
42 to compile the source code to object code, and if successful, inject
43 and execute that code within the current context of the inferior.
44 Currently the C language is supported. The commands used to
45 interface with this new feature are:
47 compile code [-raw|-r] [--] [source code]
48 compile file [-raw|-r] filename
52 queue-signal signal-name-or-number
53 Queue a signal to be delivered to the thread when it is resumed.
55 add-auto-load-scripts-directory directory
56 Add entries to the list of directories from which to load auto-loaded
59 maint print user-registers
60 List all currently available "user" registers.
62 compile code [-r|-raw] [--] [source code]
63 Compile, inject, and execute in the inferior the executable object
64 code produced by compiling the provided source code.
66 compile file [-r|-raw] filename
67 Compile and inject into the inferior the executable object code
68 produced by compiling the source code stored in the filename
71 * On resume, GDB now always passes the signal the program had stopped
72 for to the thread the signal was sent to, even if the user changed
73 threads before resuming. Previously GDB would often (but not
74 always) deliver the signal to the thread that happens to be current
77 * Conversely, the "signal" command now consistently delivers the
78 requested signal to the current thread. GDB now asks for
79 confirmation if the program had stopped for a signal and the user
80 switched threads meanwhile.
82 * "breakpoint always-inserted" modes "off" and "auto" merged.
84 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
85 won't remove breakpoints from the target until all threads stop,
86 even in non-stop mode. The "auto" mode has been removed, and "off"
87 is now the default mode.
91 ** The -list-thread-groups command outputs an exit-code field for
92 inferiors that have exited.
96 Support for these obsolete configurations has been removed.
98 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
99 SGI Irix-5.x mips-*-irix5*
100 SGI Irix-6.x mips-*-irix6*
101 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
102 VAX running Ultrix vax-*-ultrix*
104 *** Changes in GDB 7.8
106 * New command line options
109 This is an alias for the --data-directory option.
111 * GDB supports printing and modifying of variable length automatic arrays
112 as specified in ISO C99.
114 * The ARM simulator now supports instruction level tracing
115 with or without disassembly.
119 GDB now has support for scripting using Guile. Whether this is
120 available is determined at configure time.
121 Guile version 2.0 or greater is required.
122 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
124 * New commands (for set/show, see "New options" below)
128 Invoke CODE by passing it to the Guile interpreter.
132 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
134 info auto-load guile-scripts [regexp]
135 Print the list of automatically loaded Guile scripts.
137 * The source command is now capable of sourcing Guile scripts.
138 This feature is dependent on the debugger being built with Guile support.
142 set print symbol-loading (off|brief|full)
143 show print symbol-loading
144 Control whether to print informational messages when loading symbol
145 information for a file. The default is "full", but when debugging
146 programs with large numbers of shared libraries the amount of output
149 set guile print-stack (none|message|full)
150 show guile print-stack
151 Show a stack trace when an error is encountered in a Guile script.
153 set auto-load guile-scripts (on|off)
154 show auto-load guile-scripts
155 Control auto-loading of Guile script files.
157 maint ada set ignore-descriptive-types (on|off)
158 maint ada show ignore-descriptive-types
159 Control whether the debugger should ignore descriptive types in Ada
160 programs. The default is not to ignore the descriptive types. See
161 the user manual for more details on descriptive types and the intended
162 usage of this option.
164 set auto-connect-native-target
166 Control whether GDB is allowed to automatically connect to the
167 native target for the run, attach, etc. commands when not connected
168 to any target yet. See also "target native" below.
170 set record btrace replay-memory-access (read-only|read-write)
171 show record btrace replay-memory-access
172 Control what memory accesses are allowed during replay.
174 maint set target-async (on|off)
175 maint show target-async
176 This controls whether GDB targets operate in synchronous or
177 asynchronous mode. Normally the default is asynchronous, if it is
178 available; but this can be changed to more easily debug problems
179 occurring only in synchronous mode.
181 set mi-async (on|off)
183 Control whether MI asynchronous mode is preferred. This supersedes
184 "set target-async" of previous GDB versions.
186 * "set target-async" is deprecated as a CLI option and is now an alias
187 for "set mi-async" (only puts MI into async mode).
189 * Background execution commands (e.g., "c&", "s&", etc.) are now
190 possible ``out of the box'' if the target supports them. Previously
191 the user would need to explicitly enable the possibility with the
192 "set target-async on" command.
194 * New features in the GDB remote stub, GDBserver
196 ** New option --debug-format=option1[,option2,...] allows one to add
197 additional text to each output. At present only timestamps
198 are supported: --debug-format=timestamps.
199 Timestamps can also be turned on with the
200 "monitor set debug-format timestamps" command from GDB.
202 * The 'record instruction-history' command now starts counting instructions
203 at one. This also affects the instruction ranges reported by the
204 'record function-call-history' command when given the /i modifier.
206 * The command 'record function-call-history' supports a new modifier '/c' to
207 indent the function names based on their call stack depth.
208 The fields for the '/i' and '/l' modifier have been reordered.
209 The source line range is now prefixed with 'at'.
210 The instruction range is now prefixed with 'inst'.
211 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
212 "record instruction-history" and "list" commands.
214 * The ranges given as arguments to the 'record function-call-history' and
215 'record instruction-history' commands are now inclusive.
217 * The btrace record target now supports the 'record goto' command.
218 For locations inside the execution trace, the back trace is computed
219 based on the information stored in the execution trace.
221 * The btrace record target supports limited reverse execution and replay.
222 The target does not record data and therefore does not allow reading
225 * The "catch syscall" command now works on s390*-linux* targets.
227 * The "compare-sections" command is no longer specific to target
228 remote. It now works with all targets.
230 * All native targets are now consistently called "native".
231 Consequently, the "target child", "target GNU", "target djgpp",
232 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
233 commands have been replaced with "target native". The QNX/NTO port
234 leaves the "procfs" target in place and adds a "native" target for
235 consistency with other ports. The impact on users should be minimal
236 as these commands previously either throwed an error, or were
237 no-ops. The target's name is visible in the output of the following
238 commands: "help target", "info target", "info files", "maint print
241 * The "target native" command now connects to the native target. This
242 can be used to launch native programs even when "set
243 auto-connect-native-target" is set to off.
245 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.
247 * Support for Intel(R) AVX-512 registers on GNU/Linux.
248 Support displaying and modifying Intel(R) AVX-512 registers
249 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
253 qXfer:btrace:read's annex
254 The qXfer:btrace:read packet supports a new annex 'delta' to read
255 branch trace incrementally.
259 ** Valid Python operations on gdb.Value objects representing
260 structs/classes invoke the corresponding overloaded operators if
262 ** New `Xmethods' feature in the Python API. Xmethods are
263 additional methods or replacements for existing methods of a C++
264 class. This feature is useful for those cases where a method
265 defined in C++ source code could be inlined or optimized out by
266 the compiler, making it unavailable to GDB.
269 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
271 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
272 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
273 its alias "share", instead.
275 * The commands "set remotebaud" and "show remotebaud" are no longer
276 supported. Use "set serial baud" and "show serial baud" (respectively)
281 ** A new option "-gdb-set mi-async" replaces "-gdb-set
282 target-async". The latter is left as a deprecated alias of the
283 former for backward compatibility. If the target supports it,
284 CLI background execution commands are now always possible by
285 default, independently of whether the frontend stated a
286 preference for asynchronous execution with "-gdb-set mi-async".
287 Previously "-gdb-set target-async off" affected both MI execution
288 commands and CLI execution commands.
290 *** Changes in GDB 7.7
292 * Improved support for process record-replay and reverse debugging on
293 arm*-linux* targets. Support for thumb32 and syscall instruction
294 recording has been added.
296 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
298 * GDB now supports Fission DWP file format version 2.
299 http://gcc.gnu.org/wiki/DebugFission
301 * New convenience function "$_isvoid", to check whether an expression
302 is void. A void expression is an expression where the type of the
303 result is "void". For example, some convenience variables may be
304 "void" when evaluated (e.g., "$_exitcode" before the execution of
305 the program being debugged; or an undefined convenience variable).
306 Another example, when calling a function whose return type is
309 * The "maintenance print objfiles" command now takes an optional regexp.
311 * The "catch syscall" command now works on arm*-linux* targets.
313 * GDB now consistently shows "<not saved>" when printing values of
314 registers the debug info indicates have not been saved in the frame
315 and there's nowhere to retrieve them from
316 (callee-saved/call-clobbered registers):
321 (gdb) info registers rax
324 Before, the former would print "<optimized out>", and the latter
325 "*value not available*".
327 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
332 ** Frame filters and frame decorators have been added.
333 ** Temporary breakpoints are now supported.
334 ** Line tables representation has been added.
335 ** New attribute 'parent_type' for gdb.Field objects.
336 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
337 ** New attribute 'name' for gdb.Type objects.
341 Nios II ELF nios2*-*-elf
342 Nios II GNU/Linux nios2*-*-linux
343 Texas Instruments MSP430 msp430*-*-elf
345 * Removed native configurations
347 Support for these a.out NetBSD and OpenBSD obsolete configurations has
348 been removed. ELF variants of these configurations are kept supported.
350 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
351 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
352 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
353 i[34567]86-*-openbsd3.[0-3]
354 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
355 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
356 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
360 Like "catch throw", but catches a re-thrown exception.
362 Renamed from old "maint check-symtabs".
364 Perform consistency checks on symtabs.
366 Expand symtabs matching an optional regexp.
369 Display the details of GDB configure-time options.
371 maint set|show per-command
372 maint set|show per-command space
373 maint set|show per-command time
374 maint set|show per-command symtab
375 Enable display of per-command gdb resource usage.
377 remove-symbol-file FILENAME
378 remove-symbol-file -a ADDRESS
379 Remove a symbol file added via add-symbol-file. The file to remove
380 can be identified by its filename or by an address that lies within
381 the boundaries of this symbol file in memory.
384 info exceptions REGEXP
385 Display the list of Ada exceptions defined in the program being
386 debugged. If provided, only the exceptions whose names match REGEXP
391 set debug symfile off|on
393 Control display of debugging info regarding reading symbol files and
394 symbol tables within those files
396 set print raw frame-arguments
397 show print raw frame-arguments
398 Set/show whether to print frame arguments in raw mode,
399 disregarding any defined pretty-printers.
401 set remote trace-status-packet
402 show remote trace-status-packet
403 Set/show the use of remote protocol qTStatus packet.
407 Control display of debugging messages related to Nios II targets.
411 Control whether target-assisted range stepping is enabled.
413 set startup-with-shell
414 show startup-with-shell
415 Specifies whether Unix child processes are started via a shell or
420 Use the target memory cache for accesses to the code segment. This
421 improves performance of remote debugging (particularly disassembly).
423 * You can now use a literal value 'unlimited' for options that
424 interpret 0 or -1 as meaning "unlimited". E.g., "set
425 trace-buffer-size unlimited" is now an alias for "set
426 trace-buffer-size -1" and "set height unlimited" is now an alias for
429 * The "set debug symtab-create" debugging option of GDB has been changed to
430 accept a verbosity level. 0 means "off", 1 provides basic debugging
431 output, and values of 2 or greater provides more verbose output.
433 * New command-line options
435 Display the details of GDB configure-time options.
437 * The command 'tsave' can now support new option '-ctf' to save trace
438 buffer in Common Trace Format.
440 * Newly installed $prefix/bin/gcore acts as a shell interface for the
443 * GDB now implements the the C++ 'typeid' operator.
445 * The new convenience variable $_exception holds the exception being
446 thrown or caught at an exception-related catchpoint.
448 * The exception-related catchpoints, like "catch throw", now accept a
449 regular expression which can be used to filter exceptions by type.
451 * The new convenience variable $_exitsignal is automatically set to
452 the terminating signal number when the program being debugged dies
453 due to an uncaught signal.
457 ** All MI commands now accept an optional "--language" option.
458 Support for this feature can be verified by using the "-list-features"
459 command, which should contain "language-option".
461 ** The new command -info-gdb-mi-command allows the user to determine
462 whether a GDB/MI command is supported or not.
464 ** The "^error" result record returned when trying to execute an undefined
465 GDB/MI command now provides a variable named "code" whose content is the
466 "undefined-command" error code. Support for this feature can be verified
467 by using the "-list-features" command, which should contain
468 "undefined-command-error-code".
470 ** The -trace-save MI command can optionally save trace buffer in Common
473 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
475 ** The command -data-list-register-values now accepts an optional
476 "--skip-unavailable" option. When used, only the available registers
479 ** The new command -trace-frame-collected dumps collected variables,
480 computed expressions, tvars, memory and registers in a traceframe.
482 ** The commands -stack-list-locals, -stack-list-arguments and
483 -stack-list-variables now accept an option "--skip-unavailable".
484 When used, only the available locals or arguments are displayed.
486 ** The -exec-run command now accepts an optional "--start" option.
487 When used, the command follows the same semantics as the "start"
488 command, stopping the program's execution at the start of its
489 main subprogram. Support for this feature can be verified using
490 the "-list-features" command, which should contain
491 "exec-run-start-option".
493 ** The new commands -catch-assert and -catch-exceptions insert
494 catchpoints stopping the program when Ada exceptions are raised.
496 ** The new command -info-ada-exceptions provides the equivalent of
497 the new "info exceptions" command.
499 * New system-wide configuration scripts
500 A GDB installation now provides scripts suitable for use as system-wide
501 configuration scripts for the following systems:
505 * GDB now supports target-assigned range stepping with remote targets.
506 This improves the performance of stepping source lines by reducing
507 the number of control packets from/to GDB. See "New remote packets"
510 * GDB now understands the element 'tvar' in the XML traceframe info.
511 It has the id of the collected trace state variables.
513 * On S/390 targets that provide the transactional-execution feature,
514 the program interruption transaction diagnostic block (TDB) is now
515 represented as a number of additional "registers" in GDB.
521 The vCont packet supports a new 'r' action, that tells the remote
522 stub to step through an address range itself, without GDB
523 involvemement at each single-step.
525 qXfer:libraries-svr4:read's annex
526 The previously unused annex of the qXfer:libraries-svr4:read packet
527 is now used to support passing an argument list. The remote stub
528 reports support for this argument list to GDB's qSupported query.
529 The defined arguments are "start" and "prev", used to reduce work
530 necessary for library list updating, resulting in significant
533 * New features in the GDB remote stub, GDBserver
535 ** GDBserver now supports target-assisted range stepping. Currently
536 enabled on x86/x86_64 GNU/Linux targets.
538 ** GDBserver now adds element 'tvar' in the XML in the reply to
539 'qXfer:traceframe-info:read'. It has the id of the collected
540 trace state variables.
542 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
545 * New 'z' formatter for printing and examining memory, this displays the
546 value as hexadecimal zero padded on the left to the size of the type.
548 * GDB can now use Windows x64 unwinding data.
550 * The "set remotebaud" command has been replaced by "set serial baud".
551 Similarly, "show remotebaud" has been replaced by "show serial baud".
552 The "set remotebaud" and "show remotebaud" commands are still available
553 to provide backward compatibility with older versions of GDB.
555 *** Changes in GDB 7.6
557 * Target record has been renamed to record-full.
558 Record/replay is now enabled with the "record full" command.
559 This also affects settings that are associated with full record/replay
560 that have been moved from "set/show record" to "set/show record full":
562 set|show record full insn-number-max
563 set|show record full stop-at-limit
564 set|show record full memory-query
566 * A new record target "record-btrace" has been added. The new target
567 uses hardware support to record the control-flow of a process. It
568 does not support replaying the execution, but it implements the
569 below new commands for investigating the recorded execution log.
570 This new recording method can be enabled using:
574 The "record-btrace" target is only available on Intel Atom processors
575 and requires a Linux kernel 2.6.32 or later.
577 * Two new commands have been added for record/replay to give information
578 about the recorded execution without having to replay the execution.
579 The commands are only supported by "record btrace".
581 record instruction-history prints the execution history at
582 instruction granularity
584 record function-call-history prints the execution history at
587 * New native configurations
589 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
590 FreeBSD/powerpc powerpc*-*-freebsd
591 x86_64/Cygwin x86_64-*-cygwin*
592 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
596 ARM AArch64 aarch64*-*-elf
597 ARM AArch64 GNU/Linux aarch64*-*-linux
598 Lynx 178 PowerPC powerpc-*-lynx*178
599 x86_64/Cygwin x86_64-*-cygwin*
600 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
602 * If the configured location of system.gdbinit file (as given by the
603 --with-system-gdbinit option at configure time) is in the
604 data-directory (as specified by --with-gdb-datadir at configure
605 time) or in one of its subdirectories, then GDB will look for the
606 system-wide init file in the directory specified by the
607 --data-directory command-line option.
609 * New command line options:
611 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
612 other initialization files, unlike -nx which disables all of them.
614 * Removed command line options
616 -epoch This was used by the gdb mode in Epoch, an ancient fork of
619 * The 'ptype' and 'whatis' commands now accept an argument to control
622 * 'info proc' now works on some core files.
626 ** Vectors can be created with gdb.Type.vector.
628 ** Python's atexit.register now works in GDB.
630 ** Types can be pretty-printed via a Python API.
632 ** Python 3 is now supported (in addition to Python 2.4 or later)
634 ** New class gdb.Architecture exposes GDB's internal representation
635 of architecture in the Python API.
637 ** New method Frame.architecture returns the gdb.Architecture object
638 corresponding to the frame's architecture.
640 * New Python-based convenience functions:
642 ** $_memeq(buf1, buf2, length)
643 ** $_streq(str1, str2)
645 ** $_regex(str, regex)
647 * The 'cd' command now defaults to using '~' (the home directory) if not
650 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
651 default for GCC since November 2000.
653 * The command 'forward-search' can now be abbreviated as 'fo'.
655 * The command 'info tracepoints' can now display 'installed on target'
656 or 'not installed on target' for each non-pending location of tracepoint.
658 * New configure options
660 --enable-libmcheck/--disable-libmcheck
661 By default, development versions are built with -lmcheck on hosts
662 that support it, in order to help track memory corruption issues.
663 Release versions, on the other hand, are built without -lmcheck
664 by default. The --enable-libmcheck/--disable-libmcheck configure
665 options allow the user to override that default.
666 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
667 This configure option allows the user to build GDB with
668 libbabeltrace using which GDB can read Common Trace Format data.
670 * New commands (for set/show, see "New options" below)
673 Catch signals. This is similar to "handle", but allows commands and
674 conditions to be attached.
677 List the BFDs known to GDB.
679 python-interactive [command]
681 Start a Python interactive prompt, or evaluate the optional command
682 and print the result of expressions.
685 "py" is a new alias for "python".
687 enable type-printer [name]...
688 disable type-printer [name]...
689 Enable or disable type printers.
693 ** For the Renesas Super-H architecture, the "regs" command has been removed
694 (has been deprecated in GDB 7.5), and "info all-registers" should be used
699 set print type methods (on|off)
700 show print type methods
701 Control whether method declarations are displayed by "ptype".
702 The default is to show them.
704 set print type typedefs (on|off)
705 show print type typedefs
706 Control whether typedef definitions are displayed by "ptype".
707 The default is to show them.
709 set filename-display basename|relative|absolute
710 show filename-display
711 Control the way in which filenames is displayed.
712 The default is "relative", which preserves previous behavior.
714 set trace-buffer-size
715 show trace-buffer-size
716 Request target to change the size of trace buffer.
718 set remote trace-buffer-size-packet auto|on|off
719 show remote trace-buffer-size-packet
720 Control the use of the remote protocol `QTBuffer:size' packet.
724 Control display of debugging messages related to ARM AArch64.
727 set debug coff-pe-read
728 show debug coff-pe-read
729 Control display of debugging messages related to reading of COFF/PE
734 Control display of debugging messages related to Mach-O symbols
737 set debug notification
738 show debug notification
739 Control display of debugging info for async remote notification.
743 ** Command parameter changes are now notified using new async record
744 "=cmd-param-changed".
745 ** Trace frame changes caused by command "tfind" are now notified using
746 new async record "=traceframe-changed".
747 ** The creation, deletion and modification of trace state variables
748 are now notified using new async records "=tsv-created",
749 "=tsv-deleted" and "=tsv-modified".
750 ** The start and stop of process record are now notified using new
751 async record "=record-started" and "=record-stopped".
752 ** Memory changes are now notified using new async record
754 ** The data-disassemble command response will include a "fullname" field
755 containing the absolute file name when source has been requested.
756 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
757 command, to allow pattern filling of memory areas.
758 ** New commands "-catch-load"/"-catch-unload" added for intercepting
759 library load/unload events.
760 ** The response to breakpoint commands and breakpoint async records
761 includes an "installed" field containing a boolean state about each
762 non-pending tracepoint location is whether installed on target or not.
763 ** Output of the "-trace-status" command includes a "trace-file" field
764 containing the name of the trace file being examined. This field is
765 optional, and only present when examining a trace file.
766 ** The "fullname" field is now always present along with the "file" field,
767 even if the file cannot be found by GDB.
769 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
770 You must have the LZMA library available when configuring GDB for this
771 feature to be enabled. For more information, see:
772 http://fedoraproject.org/wiki/Features/MiniDebugInfo
777 Set the size of trace buffer. The remote stub reports support for this
778 packet to gdb's qSupported query.
781 Enable Branch Trace Store (BTS)-based branch tracing for the current
782 thread. The remote stub reports support for this packet to gdb's
786 Disable branch tracing for the current thread. The remote stub reports
787 support for this packet to gdb's qSupported query.
790 Read the traced branches for the current thread. The remote stub
791 reports support for this packet to gdb's qSupported query.
793 *** Changes in GDB 7.5
795 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
796 for more x32 ABI info.
798 * GDB now supports access to MIPS DSP registers on Linux targets.
800 * GDB now supports debugging microMIPS binaries.
802 * The "info os" command on GNU/Linux can now display information on
803 several new classes of objects managed by the operating system:
804 "info os procgroups" lists process groups
805 "info os files" lists file descriptors
806 "info os sockets" lists internet-domain sockets
807 "info os shm" lists shared-memory regions
808 "info os semaphores" lists semaphores
809 "info os msg" lists message queues
810 "info os modules" lists loaded kernel modules
812 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
813 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
814 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
815 options and inspect the probe arguments using the new $_probe_arg family
816 of convenience variables. You can obtain more information about SystemTap
817 in <http://sourceware.org/systemtap/>.
819 * GDB now supports reversible debugging on ARM, it allows you to
820 debug basic ARM and THUMB instructions, and provides
821 record/replay support.
823 * The option "symbol-reloading" has been deleted as it is no longer used.
827 ** GDB commands implemented in Python can now be put in command class
830 ** The "maint set python print-stack on|off" is now deleted.
832 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
833 apply "flag enum"-style pretty-printing to any enum.
835 ** gdb.lookup_symbol can now work when there is no current frame.
837 ** gdb.Symbol now has a 'line' attribute, holding the line number in
838 the source at which the symbol was defined.
840 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
841 method 'value'. The former indicates whether the symbol needs a
842 frame in order to compute its value, and the latter computes the
845 ** A new method 'referenced_value' on gdb.Value objects which can
846 dereference pointer as well as C++ reference values.
848 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
849 which return the global and static blocks (as gdb.Block objects),
850 of the underlying symbol table, respectively.
852 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
853 object associated with a PC value.
855 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
856 of the address range occupied by code for the current source line.
858 * Go language support.
859 GDB now supports debugging programs written in the Go programming
862 * GDBserver now supports stdio connections.
863 E.g. (gdb) target remote | ssh myhost gdbserver - hello
865 * The binary "gdbtui" can no longer be built or installed.
866 Use "gdb -tui" instead.
868 * GDB will now print "flag" enums specially. A flag enum is one where
869 all the enumerator values have no bits in common when pairwise
870 "and"ed. When printing a value whose type is a flag enum, GDB will
871 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
872 (gdb) print (enum E) 3
875 * The filename part of a linespec will now match trailing components
876 of a source file name. For example, "break gcc/expr.c:1000" will
877 now set a breakpoint in build/gcc/expr.c, but not
880 * The "info proc" and "generate-core-file" commands will now also
881 work on remote targets connected to GDBserver on Linux.
883 * The command "info catch" has been removed. It has been disabled
886 * The "catch exception" and "catch assert" commands now accept
887 a condition at the end of the command, much like the "break"
888 command does. For instance:
890 (gdb) catch exception Constraint_Error if Barrier = True
892 Previously, it was possible to add a condition to such catchpoints,
893 but it had to be done as a second step, after the catchpoint had been
894 created, using the "condition" command.
896 * The "info static-tracepoint-marker" command will now also work on
897 native Linux targets with in-process agent.
899 * GDB can now set breakpoints on inlined functions.
901 * The .gdb_index section has been updated to include symbols for
902 inlined functions. GDB will ignore older .gdb_index sections by
903 default, which could cause symbol files to be loaded more slowly
904 until their .gdb_index sections can be recreated. The new command
905 "set use-deprecated-index-sections on" will cause GDB to use any older
906 .gdb_index sections it finds. This will restore performance, but the
907 ability to set breakpoints on inlined functions will be lost in symbol
908 files with older .gdb_index sections.
910 The .gdb_index section has also been updated to record more information
911 about each symbol. This speeds up the "info variables", "info functions"
912 and "info types" commands when used with programs having the .gdb_index
913 section, as well as speeding up debugging with shared libraries using
914 the .gdb_index section.
916 * Ada support for GDB/MI Variable Objects has been added.
918 * GDB can now support 'breakpoint always-inserted mode' in 'record'
923 ** New command -info-os is the MI equivalent of "info os".
925 ** Output logs ("set logging" and related) now include MI output.
929 ** "set use-deprecated-index-sections on|off"
930 "show use-deprecated-index-sections on|off"
931 Controls the use of deprecated .gdb_index sections.
933 ** "catch load" and "catch unload" can be used to stop when a shared
934 library is loaded or unloaded, respectively.
936 ** "enable count" can be used to auto-disable a breakpoint after
939 ** "info vtbl" can be used to show the virtual method tables for
940 C++ and Java objects.
942 ** "explore" and its sub commands "explore value" and "explore type"
943 can be used to recursively explore values and types of
944 expressions. These commands are available only if GDB is
945 configured with '--with-python'.
947 ** "info auto-load" shows status of all kinds of auto-loaded files,
948 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
949 sequences of commands files, "info auto-load python-scripts"
950 shows status of auto-loading Python script files,
951 "info auto-load local-gdbinit" shows status of loading init file
952 (.gdbinit) from current directory and "info auto-load libthread-db" shows
953 status of inferior specific thread debugging shared library loading.
955 ** "info auto-load-scripts", "set auto-load-scripts on|off"
956 and "show auto-load-scripts" commands have been deprecated, use their
957 "info auto-load python-scripts", "set auto-load python-scripts on|off"
958 and "show auto-load python-scripts" counterparts instead.
960 ** "dprintf location,format,args..." creates a dynamic printf, which
961 is basically a breakpoint that does a printf and immediately
962 resumes your program's execution, so it is like a printf that you
963 can insert dynamically at runtime instead of at compiletime.
965 ** "set print symbol"
967 Controls whether GDB attempts to display the symbol, if any,
968 corresponding to addresses it prints. This defaults to "on", but
969 you can set it to "off" to restore GDB's previous behavior.
971 * Deprecated commands
973 ** For the Renesas Super-H architecture, the "regs" command has been
974 deprecated, and "info all-registers" should be used instead.
978 Renesas RL78 rl78-*-elf
979 HP OpenVMS ia64 ia64-hp-openvms*
981 * GDBserver supports evaluation of breakpoint conditions. When
982 support is advertised by GDBserver, GDB may be told to send the
983 breakpoint conditions in bytecode form to GDBserver. GDBserver
984 will only report the breakpoint trigger to GDB when its condition
990 show mips compression
991 Select the compressed ISA encoding used in functions that have no symbol
992 information available. The encoding can be set to either of:
995 and is updated automatically from ELF file flags if available.
997 set breakpoint condition-evaluation
998 show breakpoint condition-evaluation
999 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1000 GDBserver ("target"). Default option "auto" chooses the most efficient
1002 This option can improve debugger efficiency depending on the speed of the
1006 Disable auto-loading globally.
1009 Show auto-loading setting of all kinds of auto-loaded files.
1011 set auto-load gdb-scripts on|off
1012 show auto-load gdb-scripts
1013 Control auto-loading of GDB canned sequences of commands files.
1015 set auto-load python-scripts on|off
1016 show auto-load python-scripts
1017 Control auto-loading of Python script files.
1019 set auto-load local-gdbinit on|off
1020 show auto-load local-gdbinit
1021 Control loading of init file (.gdbinit) from current directory.
1023 set auto-load libthread-db on|off
1024 show auto-load libthread-db
1025 Control auto-loading of inferior specific thread debugging shared library.
1027 set auto-load scripts-directory <dir1>[:<dir2>...]
1028 show auto-load scripts-directory
1029 Set a list of directories from which to load auto-loaded scripts.
1030 Automatically loaded Python scripts and GDB scripts are located in one
1031 of the directories listed by this option.
1032 The delimiter (':' above) may differ according to the host platform.
1034 set auto-load safe-path <dir1>[:<dir2>...]
1035 show auto-load safe-path
1036 Set a list of directories from which it is safe to auto-load files.
1037 The delimiter (':' above) may differ according to the host platform.
1039 set debug auto-load on|off
1040 show debug auto-load
1041 Control display of debugging info for auto-loading the files above.
1043 set dprintf-style gdb|call|agent
1045 Control the way in which a dynamic printf is performed; "gdb"
1046 requests a GDB printf command, while "call" causes dprintf to call a
1047 function in the inferior. "agent" requests that the target agent
1048 (such as GDBserver) do the printing.
1050 set dprintf-function <expr>
1051 show dprintf-function
1052 set dprintf-channel <expr>
1053 show dprintf-channel
1054 Set the function and optional first argument to the call when using
1055 the "call" style of dynamic printf.
1057 set disconnected-dprintf on|off
1058 show disconnected-dprintf
1059 Control whether agent-style dynamic printfs continue to be in effect
1060 after GDB disconnects.
1062 * New configure options
1064 --with-auto-load-dir
1065 Configure default value for the 'set auto-load scripts-directory'
1066 setting above. It defaults to '$debugdir:$datadir/auto-load',
1067 $debugdir representing global debugging info directories (available
1068 via 'show debug-file-directory') and $datadir representing GDB's data
1069 directory (available via 'show data-directory').
1071 --with-auto-load-safe-path
1072 Configure default value for the 'set auto-load safe-path' setting
1073 above. It defaults to the --with-auto-load-dir setting.
1075 --without-auto-load-safe-path
1076 Set 'set auto-load safe-path' to '/', effectively disabling this
1079 * New remote packets
1081 z0/z1 conditional breakpoints extension
1083 The z0/z1 breakpoint insertion packets have been extended to carry
1084 a list of conditional expressions over to the remote stub depending on the
1085 condition evaluation mode. The use of this extension can be controlled
1086 via the "set remote conditional-breakpoints-packet" command.
1090 Specify the signals which the remote stub may pass to the debugged
1091 program without GDB involvement.
1093 * New command line options
1095 --init-command=FILE, -ix Like --command, -x but execute it
1096 before loading inferior.
1097 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1098 execute it before loading inferior.
1100 *** Changes in GDB 7.4
1102 * GDB now handles ambiguous linespecs more consistently; the existing
1103 FILE:LINE support has been expanded to other types of linespecs. A
1104 breakpoint will now be set on all matching locations in all
1105 inferiors, and locations will be added or removed according to
1108 * GDB now allows you to skip uninteresting functions and files when
1109 stepping with the "skip function" and "skip file" commands.
1111 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1112 and "show remote hardware-watchpoint-length-limit". These allows to
1113 set or show the maximum length limit (in bytes) of a remote
1114 target hardware watchpoint.
1116 This allows e.g. to use "unlimited" hardware watchpoints with the
1117 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1118 watchpoints are slower than real hardware watchpoints but are
1119 significantly faster than gdb software watchpoints.
1123 ** The register_pretty_printer function in module gdb.printing now takes
1124 an optional `replace' argument. If True, the new printer replaces any
1127 ** The "maint set python print-stack on|off" command has been
1128 deprecated and will be deleted in GDB 7.5.
1129 A new command: "set python print-stack none|full|message" has
1130 replaced it. Additionally, the default for "print-stack" is
1131 now "message", which just prints the error message without
1134 ** A prompt substitution hook (prompt_hook) is now available to the
1137 ** A new Python module, gdb.prompt has been added to the GDB Python
1138 modules library. This module provides functionality for
1139 escape sequences in prompts (used by set/show
1140 extended-prompt). These escape sequences are replaced by their
1141 corresponding value.
1143 ** Python commands and convenience-functions located in
1144 'data-directory'/python/gdb/command and
1145 'data-directory'/python/gdb/function are now automatically loaded
1148 ** Blocks now provide four new attributes. global_block and
1149 static_block will return the global and static blocks
1150 respectively. is_static and is_global are boolean attributes
1151 that indicate if the block is one of those two types.
1153 ** Symbols now provide the "type" attribute, the type of the symbol.
1155 ** The "gdb.breakpoint" function has been deprecated in favor of
1158 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1159 of a function. This class is based on the "finish" command
1160 available in the CLI.
1162 ** Type objects for struct and union types now allow access to
1163 the fields using standard Python dictionary (mapping) methods.
1164 For example, "some_type['myfield']" now works, as does
1165 "some_type.items()".
1167 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1170 ** A new function, "deep_items" has been added to the gdb.types
1171 module in the GDB Python modules library. This function returns
1172 an iterator over the fields of a struct or union type. Unlike
1173 the standard Python "iteritems" method, it will recursively traverse
1174 any anonymous fields.
1178 ** "*stopped" events can report several new "reason"s, such as
1181 ** Breakpoint changes are now notified using new async records, like
1182 "=breakpoint-modified".
1184 ** New command -ada-task-info.
1186 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1187 $sdir specifies the default system locations of shared libraries.
1188 $pdir specifies the directory where the libpthread used by the application
1191 GDB no longer looks in $sdir and $pdir after it has searched the directories
1192 mentioned in libthread-db-search-path. If you want to search those
1193 directories, they must be specified in libthread-db-search-path.
1194 The default value of libthread-db-search-path on GNU/Linux and Solaris
1195 systems is now "$sdir:$pdir".
1197 $pdir is not supported by gdbserver, it is currently ignored.
1198 $sdir is supported by gdbserver.
1200 * New configure option --with-iconv-bin.
1201 When using the internationalization support like the one in the GNU C
1202 library, GDB will invoke the "iconv" program to get a list of supported
1203 character sets. If this program lives in a non-standard location, one can
1204 use this option to specify where to find it.
1206 * When natively debugging programs on PowerPC BookE processors running
1207 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1208 watchpoints, which specify a mask in addition to an address to watch.
1209 The mask specifies that some bits of an address (the bits which are
1210 reset in the mask) should be ignored when matching the address accessed
1211 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1212 section in the user manual for more details.
1214 * The new option --once causes GDBserver to stop listening for connections once
1215 the first connection is made. The listening port used by GDBserver will
1216 become available after that.
1218 * New commands "info macros" and "alias" have been added.
1220 * New function parameters suffix @entry specifies value of function parameter
1221 at the time the function got called. Entry values are available only since
1227 "!" is now an alias of the "shell" command.
1228 Note that no space is needed between "!" and SHELL COMMAND.
1232 watch EXPRESSION mask MASK_VALUE
1233 The watch command now supports the mask argument which allows creation
1234 of masked watchpoints, if the current architecture supports this feature.
1236 info auto-load-scripts [REGEXP]
1237 This command was formerly named "maintenance print section-scripts".
1238 It is now generally useful and is no longer a maintenance-only command.
1240 info macro [-all] [--] MACRO
1241 The info macro command has new options `-all' and `--'. The first for
1242 printing all definitions of a macro. The second for explicitly specifying
1243 the end of arguments and the beginning of the macro name in case the macro
1244 name starts with a hyphen.
1246 collect[/s] EXPRESSIONS
1247 The tracepoint collect command now takes an optional modifier "/s"
1248 that directs it to dereference pointer-to-character types and
1249 collect the bytes of memory up to a zero byte. The behavior is
1250 similar to what you see when you use the regular print command on a
1251 string. An optional integer following the "/s" sets a bound on the
1252 number of bytes that will be collected.
1255 The trace start command now interprets any supplied arguments as a
1256 note to be recorded with the trace run, with an effect similar to
1257 setting the variable trace-notes.
1260 The trace stop command now interprets any arguments as a note to be
1261 mentioned along with the tstatus report that the trace was stopped
1262 with a command. The effect is similar to setting the variable
1265 * Tracepoints can now be enabled and disabled at any time after a trace
1266 experiment has been started using the standard "enable" and "disable"
1267 commands. It is now possible to start a trace experiment with no enabled
1268 tracepoints; GDB will display a warning, but will allow the experiment to
1269 begin, assuming that tracepoints will be enabled as needed while the trace
1272 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1273 locations with 4-byte instructions, when they were previously
1274 limited to locations with instructions of 5 bytes or longer.
1278 set debug dwarf2-read
1279 show debug dwarf2-read
1280 Turns on or off display of debugging messages related to reading
1281 DWARF debug info. The default is off.
1283 set debug symtab-create
1284 show debug symtab-create
1285 Turns on or off display of debugging messages related to symbol table
1286 creation. The default is off.
1289 show extended-prompt
1290 Set the GDB prompt, and allow escape sequences to be inserted to
1291 display miscellaneous information (see 'help set extended-prompt'
1292 for the list of sequences). This prompt (and any information
1293 accessed through the escape sequences) is updated every time the
1294 prompt is displayed.
1296 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1297 show print entry-values
1298 Set printing of frame argument values at function entry. In some cases
1299 GDB can determine the value of function argument which was passed by the
1300 function caller, even if the value was modified inside the called function.
1302 set debug entry-values
1303 show debug entry-values
1304 Control display of debugging info for determining frame argument values at
1305 function entry and virtual tail call frames.
1307 set basenames-may-differ
1308 show basenames-may-differ
1309 Set whether a source file may have multiple base names.
1310 (A "base name" is the name of a file with the directory part removed.
1311 Example: The base name of "/home/user/hello.c" is "hello.c".)
1312 If set, GDB will canonicalize file names (e.g., expand symlinks)
1313 before comparing them. Canonicalization is an expensive operation,
1314 but it allows the same file be known by more than one base name.
1315 If not set (the default), all source files are assumed to have just
1316 one base name, and gdb will do file name comparisons more efficiently.
1322 Set a user name and notes for the current and any future trace runs.
1323 This is useful for long-running and/or disconnected traces, to
1324 inform others (or yourself) as to who is running the trace, supply
1325 contact information, or otherwise explain what is going on.
1327 set trace-stop-notes
1328 show trace-stop-notes
1329 Set a note attached to the trace run, that is displayed when the
1330 trace has been stopped by a tstop command. This is useful for
1331 instance as an explanation, if you are stopping a trace run that was
1332 started by someone else.
1334 * New remote packets
1338 Dynamically enable a tracepoint in a started trace experiment.
1342 Dynamically disable a tracepoint in a started trace experiment.
1346 Set the user and notes of the trace run.
1350 Query the current status of a tracepoint.
1354 Query the minimum length of instruction at which a fast tracepoint may
1357 * Dcache size (number of lines) and line-size are now runtime-configurable
1358 via "set dcache line" and "set dcache line-size" commands.
1362 Texas Instruments TMS320C6x tic6x-*-*
1366 Renesas RL78 rl78-*-elf
1368 *** Changes in GDB 7.3.1
1370 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1372 *** Changes in GDB 7.3
1374 * GDB has a new command: "thread find [REGEXP]".
1375 It finds the thread id whose name, target id, or thread extra info
1376 matches the given regular expression.
1378 * The "catch syscall" command now works on mips*-linux* targets.
1380 * The -data-disassemble MI command now supports modes 2 and 3 for
1381 dumping the instruction opcodes.
1383 * New command line options
1385 -data-directory DIR Specify DIR as the "data-directory".
1386 This is mostly for testing purposes.
1388 * The "maint set python auto-load on|off" command has been renamed to
1389 "set auto-load-scripts on|off".
1391 * GDB has a new command: "set directories".
1392 It is like the "dir" command except that it replaces the
1393 source path list instead of augmenting it.
1395 * GDB now understands thread names.
1397 On GNU/Linux, "info threads" will display the thread name as set by
1398 prctl or pthread_setname_np.
1400 There is also a new command, "thread name", which can be used to
1401 assign a name internally for GDB to display.
1404 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1405 has been integrated into GDB.
1409 ** The function gdb.Write now accepts an optional keyword 'stream'.
1410 This keyword, when provided, will direct the output to either
1411 stdout, stderr, or GDB's logging output.
1413 ** Parameters can now be be sub-classed in Python, and in particular
1414 you may implement the get_set_doc and get_show_doc functions.
1415 This improves how Parameter set/show documentation is processed
1416 and allows for more dynamic content.
1418 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1419 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1420 have an is_valid method.
1422 ** Breakpoints can now be sub-classed in Python, and in particular
1423 you may implement a 'stop' function that is executed each time
1424 the inferior reaches that breakpoint.
1426 ** New function gdb.lookup_global_symbol looks up a global symbol.
1428 ** GDB values in Python are now callable if the value represents a
1429 function. For example, if 'some_value' represents a function that
1430 takes two integer parameters and returns a value, you can call
1431 that function like so:
1433 result = some_value (10,20)
1435 ** Module gdb.types has been added.
1436 It contains a collection of utilities for working with gdb.Types objects:
1437 get_basic_type, has_field, make_enum_dict.
1439 ** Module gdb.printing has been added.
1440 It contains utilities for writing and registering pretty-printers.
1441 New classes: PrettyPrinter, SubPrettyPrinter,
1442 RegexpCollectionPrettyPrinter.
1443 New function: register_pretty_printer.
1445 ** New commands "info pretty-printers", "enable pretty-printer" and
1446 "disable pretty-printer" have been added.
1448 ** gdb.parameter("directories") is now available.
1450 ** New function gdb.newest_frame returns the newest frame in the
1453 ** The gdb.InferiorThread class has a new "name" attribute. This
1454 holds the thread's name.
1456 ** Python Support for Inferior events.
1457 Python scripts can add observers to be notified of events
1458 occurring in the process being debugged.
1459 The following events are currently supported:
1460 - gdb.events.cont Continue event.
1461 - gdb.events.exited Inferior exited event.
1462 - gdb.events.stop Signal received, and Breakpoint hit events.
1466 ** GDB now puts template parameters in scope when debugging in an
1467 instantiation. For example, if you have:
1469 template<int X> int func (void) { return X; }
1471 then if you step into func<5>, "print X" will show "5". This
1472 feature requires proper debuginfo support from the compiler; it
1473 was added to GCC 4.5.
1475 ** The motion commands "next", "finish", "until", and "advance" now
1476 work better when exceptions are thrown. In particular, GDB will
1477 no longer lose control of the inferior; instead, the GDB will
1478 stop the inferior at the point at which the exception is caught.
1479 This functionality requires a change in the exception handling
1480 code that was introduced in GCC 4.5.
1482 * GDB now follows GCC's rules on accessing volatile objects when
1483 reading or writing target state during expression evaluation.
1484 One notable difference to prior behavior is that "print x = 0"
1485 no longer generates a read of x; the value of the assignment is
1486 now always taken directly from the value being assigned.
1488 * GDB now has some support for using labels in the program's source in
1489 linespecs. For instance, you can use "advance label" to continue
1490 execution to a label.
1492 * GDB now has support for reading and writing a new .gdb_index
1493 section. This section holds a fast index of DWARF debugging
1494 information and can be used to greatly speed up GDB startup and
1495 operation. See the documentation for `save gdb-index' for details.
1497 * The "watch" command now accepts an optional "-location" argument.
1498 When used, this causes GDB to watch the memory referred to by the
1499 expression. Such a watchpoint is never deleted due to it going out
1502 * GDB now supports thread debugging of core dumps on GNU/Linux.
1504 GDB now activates thread debugging using the libthread_db library
1505 when debugging GNU/Linux core dumps, similarly to when debugging
1506 live processes. As a result, when debugging a core dump file, GDB
1507 is now able to display pthread_t ids of threads. For example, "info
1508 threads" shows the same output as when debugging the process when it
1509 was live. In earlier releases, you'd see something like this:
1512 * 1 LWP 6780 main () at main.c:10
1514 While now you see this:
1517 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1519 It is also now possible to inspect TLS variables when debugging core
1522 When debugging a core dump generated on a machine other than the one
1523 used to run GDB, you may need to point GDB at the correct
1524 libthread_db library with the "set libthread-db-search-path"
1525 command. See the user manual for more details on this command.
1527 * When natively debugging programs on PowerPC BookE processors running
1528 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1529 which stop execution of the inferior whenever it executes an instruction
1530 at any address within the specified range. See the "PowerPC Embedded"
1531 section in the user manual for more details.
1533 * New features in the GDB remote stub, GDBserver
1535 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1536 and i686 LynxOS (version 5.x).
1538 ** GDBserver is now supported on Blackfin Linux.
1540 * New native configurations
1542 ia64 HP-UX ia64-*-hpux*
1546 Analog Devices, Inc. Blackfin Processor bfin-*
1548 * Ada task switching is now supported on sparc-elf targets when
1549 debugging a program using the Ravenscar Profile. For more information,
1550 see the "Tasking Support when using the Ravenscar Profile" section
1551 in the GDB user manual.
1553 * Guile support was removed.
1555 * New features in the GNU simulator
1557 ** The --map-info flag lists all known core mappings.
1559 ** CFI flashes may be simulated via the "cfi" device.
1561 *** Changes in GDB 7.2
1563 * Shared library support for remote targets by default
1565 When GDB is configured for a generic, non-OS specific target, like
1566 for example, --target=arm-eabi or one of the many *-*-elf targets,
1567 GDB now queries remote stubs for loaded shared libraries using the
1568 `qXfer:libraries:read' packet. Previously, shared library support
1569 was always disabled for such configurations.
1573 ** Argument Dependent Lookup (ADL)
1575 In C++ ADL lookup directs function search to the namespaces of its
1576 arguments even if the namespace has not been imported.
1586 Here the compiler will search for `foo' in the namespace of 'b'
1587 and find A::foo. GDB now supports this. This construct is commonly
1588 used in the Standard Template Library for operators.
1590 ** Improved User Defined Operator Support
1592 In addition to member operators, GDB now supports lookup of operators
1593 defined in a namespace and imported with a `using' directive, operators
1594 defined in the global scope, operators imported implicitly from an
1595 anonymous namespace, and the ADL operators mentioned in the previous
1597 GDB now also supports proper overload resolution for all the previously
1598 mentioned flavors of operators.
1600 ** static const class members
1602 Printing of static const class members that are initialized in the
1603 class definition has been fixed.
1605 * Windows Thread Information Block access.
1607 On Windows targets, GDB now supports displaying the Windows Thread
1608 Information Block (TIB) structure. This structure is visible either
1609 by using the new command `info w32 thread-information-block' or, by
1610 dereferencing the new convenience variable named `$_tlb', a
1611 thread-specific pointer to the TIB. This feature is also supported
1612 when remote debugging using GDBserver.
1614 * Static tracepoints
1616 Static tracepoints are calls in the user program into a tracing
1617 library. One such library is a port of the LTTng kernel tracer to
1618 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1619 When debugging with GDBserver, GDB now supports combining the GDB
1620 tracepoint machinery with such libraries. For example: the user can
1621 use GDB to probe a static tracepoint marker (a call from the user
1622 program into the tracing library) with the new "strace" command (see
1623 "New commands" below). This creates a "static tracepoint" in the
1624 breakpoint list, that can be manipulated with the same feature set
1625 as fast and regular tracepoints. E.g., collect registers, local and
1626 global variables, collect trace state variables, and define
1627 tracepoint conditions. In addition, the user can collect extra
1628 static tracepoint marker specific data, by collecting the new
1629 $_sdata internal variable. When analyzing the trace buffer, you can
1630 inspect $_sdata like any other variable available to GDB. For more
1631 information, see the "Tracepoints" chapter in GDB user manual. New
1632 remote packets have been defined to support static tracepoints, see
1633 the "New remote packets" section below.
1635 * Better reconstruction of tracepoints after disconnected tracing
1637 GDB will attempt to download the original source form of tracepoint
1638 definitions when starting a trace run, and then will upload these
1639 upon reconnection to the target, resulting in a more accurate
1640 reconstruction of the tracepoints that are in use on the target.
1644 You can now exercise direct control over the ways that GDB can
1645 affect your program. For instance, you can disallow the setting of
1646 breakpoints, so that the program can run continuously (assuming
1647 non-stop mode). In addition, the "observer" variable is available
1648 to switch all of the different controls; in observer mode, GDB
1649 cannot affect the target's behavior at all, which is useful for
1650 tasks like diagnosing live systems in the field.
1652 * The new convenience variable $_thread holds the number of the
1655 * New remote packets
1659 Return the address of the Windows Thread Information Block of a given thread.
1663 In response to several of the tracepoint packets, the target may now
1664 also respond with a number of intermediate `qRelocInsn' request
1665 packets before the final result packet, to have GDB handle
1666 relocating an instruction to execute at a different address. This
1667 is particularly useful for stubs that support fast tracepoints. GDB
1668 reports support for this feature in the qSupported packet.
1672 List static tracepoint markers in the target program.
1676 List static tracepoint markers at a given address in the target
1679 qXfer:statictrace:read
1681 Read the static trace data collected (by a `collect $_sdata'
1682 tracepoint action). The remote stub reports support for this packet
1683 to gdb's qSupported query.
1687 Send the current settings of GDB's permission flags.
1691 Send part of the source (textual) form of a tracepoint definition,
1692 which includes location, conditional, and action list.
1694 * The source command now accepts a -s option to force searching for the
1695 script in the source search path even if the script name specifies
1698 * New features in the GDB remote stub, GDBserver
1700 - GDBserver now support tracepoints (including fast tracepoints, and
1701 static tracepoints). The feature is currently supported by the
1702 i386-linux and amd64-linux builds. See the "Tracepoints support
1703 in gdbserver" section in the manual for more information.
1705 GDBserver JIT compiles the tracepoint's conditional agent
1706 expression bytecode into native code whenever possible for low
1707 overhead dynamic tracepoints conditionals. For such tracepoints,
1708 an expression that examines program state is evaluated when the
1709 tracepoint is reached, in order to determine whether to capture
1710 trace data. If the condition is simple and false, processing the
1711 tracepoint finishes very quickly and no data is gathered.
1713 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1714 for static tracepoints support.
1716 - GDBserver now supports x86_64 Windows 64-bit debugging.
1718 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1719 it understands register description.
1721 * The --batch flag now disables pagination and queries.
1723 * X86 general purpose registers
1725 GDB now supports reading/writing byte, word and double-word x86
1726 general purpose registers directly. This means you can use, say,
1727 $ah or $ax to refer, respectively, to the byte register AH and
1728 16-bit word register AX that are actually portions of the 32-bit
1729 register EAX or 64-bit register RAX.
1731 * The `commands' command now accepts a range of breakpoints to modify.
1732 A plain `commands' following a command that creates multiple
1733 breakpoints affects all the breakpoints set by that command. This
1734 applies to breakpoints set by `rbreak', and also applies when a
1735 single `break' command creates multiple breakpoints (e.g.,
1736 breakpoints on overloaded c++ functions).
1738 * The `rbreak' command now accepts a filename specification as part of
1739 its argument, limiting the functions selected by the regex to those
1740 in the specified file.
1742 * Support for remote debugging Windows and SymbianOS shared libraries
1743 from Unix hosts has been improved. Non Windows GDB builds now can
1744 understand target reported file names that follow MS-DOS based file
1745 system semantics, such as file names that include drive letters and
1746 use the backslash character as directory separator. This makes it
1747 possible to transparently use the "set sysroot" and "set
1748 solib-search-path" on Unix hosts to point as host copies of the
1749 target's shared libraries. See the new command "set
1750 target-file-system-kind" described below, and the "Commands to
1751 specify files" section in the user manual for more information.
1755 eval template, expressions...
1756 Convert the values of one or more expressions under the control
1757 of the string template to a command line, and call it.
1759 set target-file-system-kind unix|dos-based|auto
1760 show target-file-system-kind
1761 Set or show the assumed file system kind for target reported file
1764 save breakpoints <filename>
1765 Save all current breakpoint definitions to a file suitable for use
1766 in a later debugging session. To read the saved breakpoint
1767 definitions, use the `source' command.
1769 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1772 info static-tracepoint-markers
1773 Display information about static tracepoint markers in the target.
1775 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1776 Define a static tracepoint by probing a marker at the given
1777 function, line, address, or marker ID.
1781 Enable and disable observer mode.
1783 set may-write-registers on|off
1784 set may-write-memory on|off
1785 set may-insert-breakpoints on|off
1786 set may-insert-tracepoints on|off
1787 set may-insert-fast-tracepoints on|off
1788 set may-interrupt on|off
1789 Set individual permissions for GDB effects on the target. Note that
1790 some of these settings can have undesirable or surprising
1791 consequences, particularly when changed in the middle of a session.
1792 For instance, disabling the writing of memory can prevent
1793 breakpoints from being inserted, cause single-stepping to fail, or
1794 even crash your program, if you disable after breakpoints have been
1795 inserted. However, GDB should not crash.
1797 set record memory-query on|off
1798 show record memory-query
1799 Control whether to stop the inferior if memory changes caused
1800 by an instruction cannot be recorded.
1805 The disassemble command now supports "start,+length" form of two arguments.
1809 ** GDB now provides a new directory location, called the python directory,
1810 where Python scripts written for GDB can be installed. The location
1811 of that directory is <data-directory>/python, where <data-directory>
1812 is the GDB data directory. For more details, see section `Scripting
1813 GDB using Python' in the manual.
1815 ** The GDB Python API now has access to breakpoints, symbols, symbol
1816 tables, program spaces, inferiors, threads and frame's code blocks.
1817 Additionally, GDB Parameters can now be created from the API, and
1818 manipulated via set/show in the CLI.
1820 ** New functions gdb.target_charset, gdb.target_wide_charset,
1821 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1823 ** New exception gdb.GdbError.
1825 ** Pretty-printers are now also looked up in the current program space.
1827 ** Pretty-printers can now be individually enabled and disabled.
1829 ** GDB now looks for names of Python scripts to auto-load in a
1830 special section named `.debug_gdb_scripts', in addition to looking
1831 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1833 * Tracepoint actions were unified with breakpoint commands. In particular,
1834 there are no longer differences in "info break" output for breakpoints and
1835 tracepoints and the "commands" command can be used for both tracepoints and
1836 regular breakpoints.
1840 ARM Symbian arm*-*-symbianelf*
1842 * D language support.
1843 GDB now supports debugging programs written in the D programming
1846 * GDB now supports the extended ptrace interface for PowerPC which is
1847 available since Linux kernel version 2.6.34. This automatically enables
1848 any hardware breakpoints and additional hardware watchpoints available in
1849 the processor. The old ptrace interface exposes just one hardware
1850 watchpoint and no hardware breakpoints.
1852 * GDB is now able to use the Data Value Compare (DVC) register available on
1853 embedded PowerPC processors to implement in hardware simple watchpoint
1854 conditions of the form:
1856 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1858 This works in native GDB running on Linux kernels with the extended ptrace
1859 interface mentioned above.
1861 *** Changes in GDB 7.1
1865 ** Namespace Support
1867 GDB now supports importing of namespaces in C++. This enables the
1868 user to inspect variables from imported namespaces. Support for
1869 namepace aliasing has also been added. So, if a namespace is
1870 aliased in the current scope (e.g. namepace C=A; ) the user can
1871 print variables using the alias (e.g. (gdb) print C::x).
1875 All known bugs relating to the printing of virtual base class were
1876 fixed. It is now possible to call overloaded static methods using a
1881 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1882 and reinterpret_cast<> are now handled by the C++ expression parser.
1886 Xilinx MicroBlaze microblaze-*-*
1891 Xilinx MicroBlaze microblaze
1894 * Multi-program debugging.
1896 GDB now has support for multi-program (a.k.a. multi-executable or
1897 multi-exec) debugging. This allows for debugging multiple inferiors
1898 simultaneously each running a different program under the same GDB
1899 session. See "Debugging Multiple Inferiors and Programs" in the
1900 manual for more information. This implied some user visible changes
1901 in the multi-inferior support. For example, "info inferiors" now
1902 lists inferiors that are not running yet or that have exited
1903 already. See also "New commands" and "New options" below.
1905 * New tracing features
1907 GDB's tracepoint facility now includes several new features:
1909 ** Trace state variables
1911 GDB tracepoints now include support for trace state variables, which
1912 are variables managed by the target agent during a tracing
1913 experiment. They are useful for tracepoints that trigger each
1914 other, so for instance one tracepoint can count hits in a variable,
1915 and then a second tracepoint has a condition that is true when the
1916 count reaches a particular value. Trace state variables share the
1917 $-syntax of GDB convenience variables, and can appear in both
1918 tracepoint actions and condition expressions. Use the "tvariable"
1919 command to create, and "info tvariables" to view; see "Trace State
1920 Variables" in the manual for more detail.
1924 GDB now includes an option for defining fast tracepoints, which
1925 targets may implement more efficiently, such as by installing a jump
1926 into the target agent rather than a trap instruction. The resulting
1927 speedup can be by two orders of magnitude or more, although the
1928 tradeoff is that some program locations on some target architectures
1929 might not allow fast tracepoint installation, for instance if the
1930 instruction to be replaced is shorter than the jump. To request a
1931 fast tracepoint, use the "ftrace" command, with syntax identical to
1932 the regular trace command.
1934 ** Disconnected tracing
1936 It is now possible to detach GDB from the target while it is running
1937 a trace experiment, then reconnect later to see how the experiment
1938 is going. In addition, a new variable disconnected-tracing lets you
1939 tell the target agent whether to continue running a trace if the
1940 connection is lost unexpectedly.
1944 GDB now has the ability to save the trace buffer into a file, and
1945 then use that file as a target, similarly to you can do with
1946 corefiles. You can select trace frames, print data that was
1947 collected in them, and use tstatus to display the state of the
1948 tracing run at the moment that it was saved. To create a trace
1949 file, use "tsave <filename>", and to use it, do "target tfile
1952 ** Circular trace buffer
1954 You can ask the target agent to handle the trace buffer as a
1955 circular buffer, discarding the oldest trace frames to make room for
1956 newer ones, by setting circular-trace-buffer to on. This feature may
1957 not be available for all target agents.
1962 The disassemble command, when invoked with two arguments, now requires
1963 the arguments to be comma-separated.
1966 The info variables command now displays variable definitions. Files
1967 which only declare a variable are not shown.
1970 The source command is now capable of sourcing Python scripts.
1971 This feature is dependent on the debugger being build with Python
1974 Related to this enhancement is also the introduction of a new command
1975 "set script-extension" (see below).
1977 * New commands (for set/show, see "New options" below)
1979 record save [<FILENAME>]
1980 Save a file (in core file format) containing the process record
1981 execution log for replay debugging at a later time.
1983 record restore <FILENAME>
1984 Restore the process record execution log that was saved at an
1985 earlier time, for replay debugging.
1987 add-inferior [-copies <N>] [-exec <FILENAME>]
1990 clone-inferior [-copies <N>] [ID]
1991 Make a new inferior ready to execute the same program another
1992 inferior has loaded.
1997 maint info program-spaces
1998 List the program spaces loaded into GDB.
2000 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2001 show remote interrupt-sequence
2002 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2003 as the sequence to the remote target in order to interrupt the execution.
2004 Ctrl-C is a default. Some system prefers BREAK which is high level of
2005 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2006 Magic SysRq g. It is BREAK signal and character 'g'.
2008 set remote interrupt-on-connect [on | off]
2009 show remote interrupt-on-connect
2010 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2011 remote target when gdb connects to it. This is needed when you debug
2014 set remotebreak [on | off]
2016 Deprecated. Use "set/show remote interrupt-sequence" instead.
2018 tvariable $NAME [ = EXP ]
2019 Create or modify a trace state variable.
2022 List trace state variables and their values.
2024 delete tvariable $NAME ...
2025 Delete one or more trace state variables.
2028 Evaluate the given expressions without collecting anything into the
2029 trace buffer. (Valid in tracepoint actions only.)
2031 ftrace FN / FILE:LINE / *ADDR
2032 Define a fast tracepoint at the given function, line, or address.
2034 * New expression syntax
2036 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2037 GDB now parses 0b101010 identically with 42.
2041 set follow-exec-mode new|same
2042 show follow-exec-mode
2043 Control whether GDB reuses the same inferior across an exec call or
2044 creates a new one. This is useful to be able to restart the old
2045 executable after the inferior having done an exec call.
2047 set default-collect EXPR, ...
2048 show default-collect
2049 Define a list of expressions to be collected at each tracepoint.
2050 This is a useful way to ensure essential items are not overlooked,
2051 such as registers or a critical global variable.
2053 set disconnected-tracing
2054 show disconnected-tracing
2055 If set to 1, the target is instructed to continue tracing if it
2056 loses its connection to GDB. If 0, the target is to stop tracing
2059 set circular-trace-buffer
2060 show circular-trace-buffer
2061 If set to on, the target is instructed to use a circular trace buffer
2062 and discard the oldest trace frames instead of stopping the trace due
2063 to a full trace buffer. If set to off, the trace stops when the buffer
2064 fills up. Some targets may not support this.
2066 set script-extension off|soft|strict
2067 show script-extension
2068 If set to "off", the debugger does not perform any script language
2069 recognition, and all sourced files are assumed to be GDB scripts.
2070 If set to "soft" (the default), files are sourced according to
2071 filename extension, falling back to GDB scripts if the first
2073 If set to "strict", files are sourced according to filename extension.
2075 set ada trust-PAD-over-XVS on|off
2076 show ada trust-PAD-over-XVS
2077 If off, activate a workaround against a bug in the debugging information
2078 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2079 the GCC sources for more information about the GNAT encoding and
2080 PAD types in particular). It is always safe to set this option to
2081 off, but this introduces a slight performance penalty. The default
2084 * Python API Improvements
2086 ** GDB provides the new class gdb.LazyString. This is useful in
2087 some pretty-printing cases. The new method gdb.Value.lazy_string
2088 provides a simple way to create objects of this type.
2090 ** The fields returned by gdb.Type.fields now have an
2091 `is_base_class' attribute.
2093 ** The new method gdb.Type.range returns the range of an array type.
2095 ** The new method gdb.parse_and_eval can be used to parse and
2096 evaluate an expression.
2098 * New remote packets
2101 Define a trace state variable.
2104 Get the current value of a trace state variable.
2107 Set desired tracing behavior upon disconnection.
2110 Set the trace buffer to be linear or circular.
2113 Get data about the tracepoints currently in use.
2117 Process record now works correctly with hardware watchpoints.
2119 Multiple bug fixes have been made to the mips-irix port, making it
2120 much more reliable. In particular:
2121 - Debugging threaded applications is now possible again. Previously,
2122 GDB would hang while starting the program, or while waiting for
2123 the program to stop at a breakpoint.
2124 - Attaching to a running process no longer hangs.
2125 - An error occurring while loading a core file has been fixed.
2126 - Changing the value of the PC register now works again. This fixes
2127 problems observed when using the "jump" command, or when calling
2128 a function from GDB, or even when assigning a new value to $pc.
2129 - With the "finish" and "return" commands, the return value for functions
2130 returning a small array is now correctly printed.
2131 - It is now possible to break on shared library code which gets executed
2132 during a shared library init phase (code executed while executing
2133 their .init section). Previously, the breakpoint would have no effect.
2134 - GDB is now able to backtrace through the signal handler for
2135 non-threaded programs.
2137 PIE (Position Independent Executable) programs debugging is now supported.
2138 This includes debugging execution of PIC (Position Independent Code) shared
2139 libraries although for that, it should be possible to run such libraries as an
2142 *** Changes in GDB 7.0
2144 * GDB now has an interface for JIT compilation. Applications that
2145 dynamically generate code can create symbol files in memory and register
2146 them with GDB. For users, the feature should work transparently, and
2147 for JIT developers, the interface is documented in the GDB manual in the
2148 "JIT Compilation Interface" chapter.
2150 * Tracepoints may now be conditional. The syntax is as for
2151 breakpoints; either an "if" clause appended to the "trace" command,
2152 or the "condition" command is available. GDB sends the condition to
2153 the target for evaluation using the same bytecode format as is used
2154 for tracepoint actions.
2156 * The disassemble command now supports: an optional /r modifier, print the
2157 raw instructions in hex as well as in symbolic form, and an optional /m
2158 modifier to print mixed source+assembly.
2160 * Process record and replay
2162 In a architecture environment that supports ``process record and
2163 replay'', ``process record and replay'' target can record a log of
2164 the process execution, and replay it with both forward and reverse
2167 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2168 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2169 set execution-direction {forward|reverse}, for targets that support
2172 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2173 feature is available with a native GDB running on kernel version
2176 * GDB now has support for multi-byte and wide character sets on the
2177 target. Strings whose character type is wchar_t, char16_t, or
2178 char32_t are now correctly printed. GDB supports wide- and unicode-
2179 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2180 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2181 `printf'. This feature requires iconv to work properly; if your
2182 system does not have a working iconv, GDB can use GNU libiconv. See
2183 the installation instructions for more information.
2185 * GDB now supports automatic retrieval of shared library files from
2186 remote targets. To use this feature, specify a system root that begins
2187 with the `remote:' prefix, either via the `set sysroot' command or via
2188 the `--with-sysroot' configure-time option.
2190 * "info sharedlibrary" now takes an optional regex of libraries to show,
2191 and it now reports if a shared library has no debugging information.
2193 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2194 now complete on file names.
2196 * When completing in expressions, gdb will attempt to limit
2197 completions to allowable structure or union fields, where appropriate.
2198 For instance, consider:
2200 # struct example { int f1; double f2; };
2201 # struct example variable;
2204 If the user types TAB at the end of this command line, the available
2205 completions will be "f1" and "f2".
2207 * Inlined functions are now supported. They show up in backtraces, and
2208 the "step", "next", and "finish" commands handle them automatically.
2210 * GDB now supports the token-splicing (##) and stringification (#)
2211 operators when expanding macros. It also supports variable-arity
2214 * GDB now supports inspecting extra signal information, exported by
2215 the new $_siginfo convenience variable. The feature is currently
2216 implemented on linux ARM, i386 and amd64.
2218 * GDB can now display the VFP floating point registers and NEON vector
2219 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2220 can provide these registers (requires Linux 2.6.30 or later). Remote
2221 and simulator targets may also provide them.
2223 * New remote packets
2226 Search memory for a sequence of bytes.
2229 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2230 operation over reliable transport links. Use of this packet is
2231 controlled by the `set remote noack-packet' command.
2234 Kill the process with the specified process ID. Use this in preference
2235 to `k' when multiprocess protocol extensions are supported.
2238 Obtains additional operating system information
2242 Read or write additional signal information.
2244 * Removed remote protocol undocumented extension
2246 An undocumented extension to the remote protocol's `S' stop reply
2247 packet that permited the stub to pass a process id was removed.
2248 Remote servers should use the `T' stop reply packet instead.
2250 * GDB now supports multiple function calling conventions according to the
2251 DWARF-2 DW_AT_calling_convention function attribute.
2253 * The SH target utilizes the aforementioned change to distinguish between gcc
2254 and Renesas calling convention. It also adds the new CLI commands
2255 `set/show sh calling-convention'.
2257 * GDB can now read compressed debug sections, as produced by GNU gold
2258 with the --compress-debug-sections=zlib flag.
2260 * 64-bit core files are now supported on AIX.
2262 * Thread switching is now supported on Tru64.
2264 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2265 which will be allocated using malloc later in program execution.
2267 * The qXfer:libraries:read remote procotol packet now allows passing a
2268 list of section offsets.
2270 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2271 conditions handling signals delivered during attach or thread creation
2272 have also been fixed.
2274 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2275 From the user's standpoint, all unqualified instances of True and False
2276 are treated as the standard definitions, regardless of context.
2278 * GDB now parses C++ symbol and type names more flexibly. For
2281 template<typename T> class C { };
2284 GDB will now correctly handle all of:
2286 ptype C<char const *>
2287 ptype C<char const*>
2288 ptype C<const char *>
2289 ptype C<const char*>
2291 * New features in the GDB remote stub, gdbserver
2293 - The "--wrapper" command-line argument tells gdbserver to use a
2294 wrapper program to launch programs for debugging.
2296 - On PowerPC and S/390 targets, it is now possible to use a single
2297 gdbserver executable to debug both 32-bit and 64-bit programs.
2298 (This requires gdbserver itself to be built as a 64-bit executable.)
2300 - gdbserver uses the new noack protocol mode for TCP connections to
2301 reduce communications latency, if also supported and enabled in GDB.
2303 - Support for the sparc64-linux-gnu target is now included in
2306 - The amd64-linux build of gdbserver now supports debugging both
2307 32-bit and 64-bit programs.
2309 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2310 now support hardware watchpoints, and will use them automatically
2315 GDB now has support for scripting using Python. Whether this is
2316 available is determined at configure time.
2318 New GDB commands can now be written in Python.
2320 * Ada tasking support
2322 Ada tasks can now be inspected in GDB. The following commands have
2326 Print the list of Ada tasks.
2328 Print detailed information about task number N.
2330 Print the task number of the current task.
2332 Switch the context of debugging to task number N.
2334 * Support for user-defined prefixed commands. The "define" command can
2335 add new commands to existing prefixes, e.g. "target".
2337 * Multi-inferior, multi-process debugging.
2339 GDB now has generalized support for multi-inferior debugging. See
2340 "Debugging Multiple Inferiors" in the manual for more information.
2341 Although availability still depends on target support, the command
2342 set is more uniform now. The GNU/Linux specific multi-forks support
2343 has been migrated to this new framework. This implied some user
2344 visible changes; see "New commands" and also "Removed commands"
2347 * Target descriptions can now describe the target OS ABI. See the
2348 "Target Description Format" section in the user manual for more
2351 * Target descriptions can now describe "compatible" architectures
2352 to indicate that the target can execute applications for a different
2353 architecture in addition to those for the main target architecture.
2354 See the "Target Description Format" section in the user manual for
2357 * Multi-architecture debugging.
2359 GDB now includes general supports for debugging applications on
2360 hybrid systems that use more than one single processor architecture
2361 at the same time. Each such hybrid architecture still requires
2362 specific support to be added. The only hybrid architecture supported
2363 in this version of GDB is the Cell Broadband Engine.
2365 * GDB now supports integrated debugging of Cell/B.E. applications that
2366 use both the PPU and SPU architectures. To enable support for hybrid
2367 Cell/B.E. debugging, you need to configure GDB to support both the
2368 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2369 --enable-targets configure option.
2371 * Non-stop mode debugging.
2373 For some targets, GDB now supports an optional mode of operation in
2374 which you can examine stopped threads while other threads continue
2375 to execute freely. This is referred to as non-stop mode, with the
2376 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2377 section in the user manual for more information.
2379 To be able to support remote non-stop debugging, a remote stub needs
2380 to implement the non-stop mode remote protocol extensions, as
2381 described in the "Remote Non-Stop" section of the user manual. The
2382 GDB remote stub, gdbserver, has been adjusted to support these
2383 extensions on linux targets.
2385 * New commands (for set/show, see "New options" below)
2387 catch syscall [NAME(S) | NUMBER(S)]
2388 Catch system calls. Arguments, which should be names of system
2389 calls or their numbers, mean catch only those syscalls. Without
2390 arguments, every syscall will be caught. When the inferior issues
2391 any of the specified syscalls, GDB will stop and announce the system
2392 call, both when it is called and when its call returns. This
2393 feature is currently available with a native GDB running on the
2394 Linux Kernel, under the following architectures: x86, x86_64,
2395 PowerPC and PowerPC64.
2397 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2399 Search memory for a sequence of bytes.
2401 maint set python print-stack
2402 maint show python print-stack
2403 Show a stack trace when an error is encountered in a Python script.
2406 Invoke CODE by passing it to the Python interpreter.
2411 These allow macros to be defined, undefined, and listed
2415 Show operating system information about processes.
2418 List the inferiors currently under GDB's control.
2421 Switch focus to inferior number NUM.
2424 Detach from inferior number NUM.
2427 Kill inferior number NUM.
2431 set spu stop-on-load
2432 show spu stop-on-load
2433 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2435 set spu auto-flush-cache
2436 show spu auto-flush-cache
2437 Control whether to automatically flush the software-managed cache
2438 during Cell/B.E. debugging.
2440 set sh calling-convention
2441 show sh calling-convention
2442 Control the calling convention used when calling SH target functions.
2445 show debug timestamp
2446 Control display of timestamps with GDB debugging output.
2448 set disassemble-next-line
2449 show disassemble-next-line
2450 Control display of disassembled source lines or instructions when
2453 set remote noack-packet
2454 show remote noack-packet
2455 Set/show the use of remote protocol QStartNoAckMode packet. See above
2456 under "New remote packets."
2458 set remote query-attached-packet
2459 show remote query-attached-packet
2460 Control use of remote protocol `qAttached' (query-attached) packet.
2462 set remote read-siginfo-object
2463 show remote read-siginfo-object
2464 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2467 set remote write-siginfo-object
2468 show remote write-siginfo-object
2469 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2472 set remote reverse-continue
2473 show remote reverse-continue
2474 Control use of remote protocol 'bc' (reverse-continue) packet.
2476 set remote reverse-step
2477 show remote reverse-step
2478 Control use of remote protocol 'bs' (reverse-step) packet.
2480 set displaced-stepping
2481 show displaced-stepping
2482 Control displaced stepping mode. Displaced stepping is a way to
2483 single-step over breakpoints without removing them from the debuggee.
2484 Also known as "out-of-line single-stepping".
2487 show debug displaced
2488 Control display of debugging info for displaced stepping.
2490 maint set internal-error
2491 maint show internal-error
2492 Control what GDB does when an internal error is detected.
2494 maint set internal-warning
2495 maint show internal-warning
2496 Control what GDB does when an internal warning is detected.
2501 Use a wrapper program to launch programs for debugging.
2503 set multiple-symbols (all|ask|cancel)
2504 show multiple-symbols
2505 The value of this variable can be changed to adjust the debugger behavior
2506 when an expression or a breakpoint location contains an ambiguous symbol
2507 name (an overloaded function name, for instance).
2509 set breakpoint always-inserted
2510 show breakpoint always-inserted
2511 Keep breakpoints always inserted in the target, as opposed to inserting
2512 them when resuming the target, and removing them when the target stops.
2513 This option can improve debugger performance on slow remote targets.
2515 set arm fallback-mode (arm|thumb|auto)
2516 show arm fallback-mode
2517 set arm force-mode (arm|thumb|auto)
2519 These commands control how ARM GDB determines whether instructions
2520 are ARM or Thumb. The default for both settings is auto, which uses
2521 the current CPSR value for instructions without symbols; previous
2522 versions of GDB behaved as if "set arm fallback-mode arm".
2524 set disable-randomization
2525 show disable-randomization
2526 Standalone programs run with the virtual address space randomization enabled
2527 by default on some platforms. This option keeps the addresses stable across
2528 multiple debugging sessions.
2532 Control whether other threads are stopped or not when some thread hits
2537 Requests that asynchronous execution is enabled in the target, if available.
2538 In this case, it's possible to resume target in the background, and interact
2539 with GDB while the target is running. "show target-async" displays the
2540 current state of asynchronous execution of the target.
2542 set target-wide-charset
2543 show target-wide-charset
2544 The target-wide-charset is the name of the character set that GDB
2545 uses when printing characters whose type is wchar_t.
2547 set tcp auto-retry (on|off)
2549 set tcp connect-timeout
2550 show tcp connect-timeout
2551 These commands allow GDB to retry failed TCP connections to a remote stub
2552 with a specified timeout period; this is useful if the stub is launched
2553 in parallel with GDB but may not be ready to accept connections immediately.
2555 set libthread-db-search-path
2556 show libthread-db-search-path
2557 Control list of directories which GDB will search for appropriate
2560 set schedule-multiple (on|off)
2561 show schedule-multiple
2562 Allow GDB to resume all threads of all processes or only threads of
2563 the current process.
2567 Use more aggressive caching for accesses to the stack. This improves
2568 performance of remote debugging (particularly backtraces) without
2569 affecting correctness.
2571 set interactive-mode (on|off|auto)
2572 show interactive-mode
2573 Control whether GDB runs in interactive mode (on) or not (off).
2574 When in interactive mode, GDB waits for the user to answer all
2575 queries. Otherwise, GDB does not wait and assumes the default
2576 answer. When set to auto (the default), GDB determines which
2577 mode to use based on the stdin settings.
2582 For program forks, this is replaced by the new more generic `info
2583 inferiors' command. To list checkpoints, you can still use the
2584 `info checkpoints' command, which was an alias for the `info forks'
2588 Replaced by the new `inferior' command. To switch between
2589 checkpoints, you can still use the `restart' command, which was an
2590 alias for the `fork' command.
2593 This is removed, since some targets don't have a notion of
2594 processes. To switch between processes, you can still use the
2595 `inferior' command using GDB's own inferior number.
2598 For program forks, this is replaced by the new more generic `kill
2599 inferior' command. To delete a checkpoint, you can still use the
2600 `delete checkpoint' command, which was an alias for the `delete
2604 For program forks, this is replaced by the new more generic `detach
2605 inferior' command. To detach a checkpoint, you can still use the
2606 `detach checkpoint' command, which was an alias for the `detach
2609 * New native configurations
2611 x86/x86_64 Darwin i[34567]86-*-darwin*
2613 x86_64 MinGW x86_64-*-mingw*
2617 Lattice Mico32 lm32-*
2618 x86 DICOS i[34567]86-*-dicos*
2619 x86_64 DICOS x86_64-*-dicos*
2622 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2623 (mingw32ce) debugging.
2629 These commands were actually not implemented on any target.
2631 *** Changes in GDB 6.8
2633 * New native configurations
2635 NetBSD/hppa hppa*-*netbsd*
2636 Xtensa GNU/Linux xtensa*-*-linux*
2640 NetBSD/hppa hppa*-*-netbsd*
2641 Xtensa GNU/Lunux xtensa*-*-linux*
2643 * Change in command line behavior -- corefiles vs. process ids.
2645 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2646 attaching to process NUMBER fails, GDB no longer attempts to open a
2647 core file named NUMBER. Attaching to a program using the -c option
2648 is no longer supported. Instead, use the '-p' or '--pid' options.
2650 * GDB can now be built as a native debugger for debugging Windows x86
2651 (mingw32) Portable Executable (PE) programs.
2653 * Pending breakpoints no longer change their number when their address
2656 * GDB now supports breakpoints with multiple locations,
2657 including breakpoints on C++ constructors, inside C++ templates,
2658 and in inlined functions.
2660 * GDB's ability to debug optimized code has been improved. GDB more
2661 accurately identifies function bodies and lexical blocks that occupy
2662 more than one contiguous range of addresses.
2664 * Target descriptions can now describe registers for PowerPC.
2666 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2667 registers on PowerPC targets.
2669 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2670 targets even when the libthread_db library is not available.
2672 * The GDB remote stub, gdbserver, now supports the new file transfer
2673 commands (remote put, remote get, and remote delete).
2675 * The GDB remote stub, gdbserver, now supports run and attach in
2676 extended-remote mode.
2678 * hppa*64*-*-hpux11* target broken
2679 The debugger is unable to start a program and fails with the following
2680 error: "Error trying to get information about dynamic linker".
2681 The gdb-6.7 release is also affected.
2683 * GDB now supports the --enable-targets= configure option to allow
2684 building a single GDB executable that supports multiple remote
2685 target architectures.
2687 * GDB now supports debugging C and C++ programs which use the
2688 Decimal Floating Point extension. In addition, the PowerPC target
2689 now has a set of pseudo-registers to inspect decimal float values
2690 stored in two consecutive float registers.
2692 * The -break-insert MI command can optionally create pending
2695 * Improved support for debugging Ada
2696 Many improvements to the Ada language support have been made. These
2698 - Better support for Ada2005 interface types
2699 - Improved handling of arrays and slices in general
2700 - Better support for Taft-amendment types
2701 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2703 - Improved command completion in Ada
2706 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2711 set print frame-arguments (all|scalars|none)
2712 show print frame-arguments
2713 The value of this variable can be changed to control which argument
2714 values should be printed by the debugger when displaying a frame.
2719 Transfer files to and from a remote target, and delete remote files.
2726 Transfer files to and from a remote target, and delete remote files.
2728 * New remote packets
2735 Open, close, read, write, and delete files on the remote system.
2738 Attach to an existing process on the remote system, in extended-remote
2742 Run a new process on the remote system, in extended-remote mode.
2744 *** Changes in GDB 6.7
2746 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2747 bfd, libiberty and opcodes, as revealed by static analysis donated by
2748 Coverity, Inc. (http://scan.coverity.com).
2750 * When looking up multiply-defined global symbols, GDB will now prefer the
2751 symbol definition in the current shared library if it was built using the
2752 -Bsymbolic linker option.
2754 * When the Text User Interface (TUI) is not configured, GDB will now
2755 recognize the -tui command-line option and print a message that the TUI
2758 * The GDB remote stub, gdbserver, now has lower overhead for high
2759 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2761 * GDB for MIPS targets now autodetects whether a remote target provides
2762 32-bit or 64-bit register values.
2764 * Support for C++ member pointers has been improved.
2766 * GDB now understands XML target descriptions, which specify the
2767 target's overall architecture. GDB can read a description from
2768 a local file or over the remote serial protocol.
2770 * Vectors of single-byte data use a new integer type which is not
2771 automatically displayed as character or string data.
2773 * The /s format now works with the print command. It displays
2774 arrays of single-byte integers and pointers to single-byte integers
2777 * Target descriptions can now describe target-specific registers,
2778 for architectures which have implemented the support (currently
2779 only ARM, M68K, and MIPS).
2781 * GDB and the GDB remote stub, gdbserver, now support the XScale
2784 * The GDB remote stub, gdbserver, has been updated to support
2785 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2786 has been rewritten to use the standard GDB remote protocol.
2788 * GDB can now step into C++ functions which are called through thunks.
2790 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2792 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2793 layout. It also supports a TextSeg= and DataSeg= response when only
2794 segment base addresses (rather than offsets) are available.
2796 * The /i format now outputs any trailing branch delay slot instructions
2797 immediately following the last instruction within the count specified.
2799 * The GDB remote protocol "T" stop reply packet now supports a
2800 "library" response. Combined with the new "qXfer:libraries:read"
2801 packet, this response allows GDB to debug shared libraries on targets
2802 where the operating system manages the list of loaded libraries (e.g.
2803 Windows and SymbianOS).
2805 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2806 (DLLs) on Windows and Windows CE targets.
2808 * GDB now supports a faster verification that a .debug file matches its binary
2809 according to its build-id signature, if the signature is present.
2815 Enable or disable hardware flow control (RTS/CTS) on the serial port
2816 when debugging using remote targets.
2818 set mem inaccessible-by-default
2819 show mem inaccessible-by-default
2820 If the target supplies a memory map, for instance via the remote
2821 protocol's "qXfer:memory-map:read" packet, setting this variable
2822 prevents GDB from accessing memory outside the memory map. This
2823 is useful for targets with memory mapped registers or which react
2824 badly to accesses of unmapped address space.
2826 set breakpoint auto-hw
2827 show breakpoint auto-hw
2828 If the target supplies a memory map, for instance via the remote
2829 protocol's "qXfer:memory-map:read" packet, setting this variable
2830 lets GDB use hardware breakpoints automatically for memory regions
2831 where it can not use software breakpoints. This covers both the
2832 "break" command and internal breakpoints used for other commands
2833 including "next" and "finish".
2836 catch exception unhandled
2837 Stop the program execution when Ada exceptions are raised.
2840 Stop the program execution when an Ada assertion failed.
2844 Set an alternate system root for target files. This is a more
2845 general version of "set solib-absolute-prefix", which is now
2846 an alias to "set sysroot".
2849 Provide extended SPU facility status information. This set of
2850 commands is available only when debugging the Cell/B.E. SPU
2853 * New native configurations
2855 OpenBSD/sh sh*-*openbsd*
2858 unset tdesc filename
2860 Use the specified local file as an XML target description, and do
2861 not query the target for its built-in description.
2865 OpenBSD/sh sh*-*-openbsd*
2866 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2867 Toshiba Media Processor mep-elf
2869 * New remote packets
2872 Ignore the specified signals; pass them directly to the debugged program
2873 without stopping other threads or reporting them to GDB.
2875 qXfer:features:read:
2876 Read an XML target description from the target, which describes its
2881 Read or write contents of an spufs file on the target system. These
2882 packets are available only on the Cell/B.E. SPU architecture.
2884 qXfer:libraries:read:
2885 Report the loaded shared libraries. Combined with new "T" packet
2886 response, this packet allows GDB to debug shared libraries on
2887 targets where the operating system manages the list of loaded
2888 libraries (e.g. Windows and SymbianOS).
2892 Support for these obsolete configurations has been removed.
2900 i[34567]86-*-lynxos*
2901 i[34567]86-*-netware*
2902 i[34567]86-*-sco3.2v5*
2903 i[34567]86-*-sco3.2v4*
2905 i[34567]86-*-sysv4.2*
2908 i[34567]86-*-unixware2*
2909 i[34567]86-*-unixware*
2918 * Other removed features
2925 Various m68k-only ROM monitors.
2932 Various Renesas ROM monitors and debugging interfaces for SH and
2937 Support for a Macraigor serial interface to on-chip debugging.
2938 GDB does not directly support the newer parallel or USB
2943 A debug information format. The predecessor to DWARF 2 and
2944 DWARF 3, which are still supported.
2946 Support for the HP aCC compiler on HP-UX/PA-RISC
2948 SOM-encapsulated symbolic debugging information, automatic
2949 invocation of pxdb, and the aCC custom C++ ABI. This does not
2950 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2951 with aCC can still be debugged on an assembly level.
2953 MIPS ".pdr" sections
2955 A MIPS-specific format used to describe stack frame layout
2956 in debugging information.
2960 GDB could work with an older version of Guile to debug
2961 the interpreter and Scheme programs running in it.
2963 set mips stack-arg-size
2964 set mips saved-gpreg-size
2966 Use "set mips abi" to control parameter passing for MIPS.
2968 *** Changes in GDB 6.6
2973 Cell Broadband Engine SPU spu-elf
2975 * GDB can now be configured as a cross-debugger targeting native Windows
2976 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2977 running on a Windows system over TCP/IP to debug Windows programs.
2979 * The GDB remote stub, gdbserver, has been updated to support Windows and
2980 Cygwin debugging. Both single-threaded and multi-threaded programs are
2983 * The "set trust-readonly-sections" command works again. This command was
2984 broken in GDB 6.3, 6.4, and 6.5.
2986 * The "load" command now supports writing to flash memory, if the remote
2987 stub provides the required support.
2989 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2990 longer requires symbolic debug information (e.g. DWARF-2).
2995 unset substitute-path
2996 show substitute-path
2997 Manage a list of substitution rules that GDB uses to rewrite the name
2998 of the directories where the sources are located. This can be useful
2999 for instance when the sources were moved to a different location
3000 between compilation and debugging.
3004 Print each CLI command as it is executed. Each command is prefixed with
3005 a number of `+' symbols representing the nesting depth.
3006 The source command now has a `-v' option to enable the same feature.
3010 The ARM Demon monitor support (RDP protocol, "target rdp").
3012 Kernel Object Display, an embedded debugging feature which only worked with
3013 an obsolete version of Cisco IOS.
3015 The 'set download-write-size' and 'show download-write-size' commands.
3017 * New remote packets
3020 Tell a stub about GDB client features, and request remote target features.
3021 The first feature implemented is PacketSize, which allows the target to
3022 specify the size of packets it can handle - to minimize the number of
3023 packets required and improve performance when connected to a remote
3027 Fetch an OS auxilliary vector from the remote stub. This packet is a
3028 more efficient replacement for qPart:auxv:read.
3030 qXfer:memory-map:read:
3031 Fetch a memory map from the remote stub, including information about
3032 RAM, ROM, and flash memory devices.
3037 Erase and program a flash memory device.
3039 * Removed remote packets
3042 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3043 used it, and only gdbserver implemented it.
3045 *** Changes in GDB 6.5
3049 Renesas M32C/M16C m32c-elf
3051 Morpho Technologies ms1 ms1-elf
3055 init-if-undefined Initialize a convenience variable, but
3056 only if it doesn't already have a value.
3058 The following commands are presently only implemented for native GNU/Linux:
3060 checkpoint Save a snapshot of the program state.
3062 restart <n> Return the program state to a
3063 previously saved state.
3065 info checkpoints List currently saved checkpoints.
3067 delete-checkpoint <n> Delete a previously saved checkpoint.
3069 set|show detach-on-fork Tell gdb whether to detach from a newly
3070 forked process, or to keep debugging it.
3072 info forks List forks of the user program that
3073 are available to be debugged.
3075 fork <n> Switch to debugging one of several
3076 forks of the user program that are
3077 available to be debugged.
3079 delete-fork <n> Delete a fork from the list of forks
3080 that are available to be debugged (and
3081 kill the forked process).
3083 detach-fork <n> Delete a fork from the list of forks
3084 that are available to be debugged (and
3085 allow the process to continue).
3089 Morpho Technologies ms2 ms1-elf
3091 * Improved Windows host support
3093 GDB now builds as a cross debugger hosted on i686-mingw32, including
3094 native console support, and remote communications using either
3095 network sockets or serial ports.
3097 * Improved Modula-2 language support
3099 GDB can now print most types in the Modula-2 syntax. This includes:
3100 basic types, set types, record types, enumerated types, range types,
3101 pointer types and ARRAY types. Procedure var parameters are correctly
3102 printed and hexadecimal addresses and character constants are also
3103 written in the Modula-2 syntax. Best results can be obtained by using
3104 GNU Modula-2 together with the -gdwarf-2 command line option.
3108 The ARM rdi-share module.
3110 The Netware NLM debug server.
3112 *** Changes in GDB 6.4
3114 * New native configurations
3116 OpenBSD/arm arm*-*-openbsd*
3117 OpenBSD/mips64 mips64-*-openbsd*
3121 Morpho Technologies ms1 ms1-elf
3123 * New command line options
3125 --batch-silent As for --batch, but totally silent.
3126 --return-child-result The debugger will exist with the same value
3127 the child (debugged) program exited with.
3128 --eval-command COMMAND, -ex COMMAND
3129 Execute a single GDB CLI command. This may be
3130 specified multiple times and in conjunction
3131 with the --command (-x) option.
3133 * Deprecated commands removed
3135 The following commands, that were deprecated in 2000, have been
3139 set|show arm disassembly-flavor set|show arm disassembler
3140 othernames set arm disassembler
3141 set|show remotedebug set|show debug remote
3142 set|show archdebug set|show debug arch
3143 set|show eventdebug set|show debug event
3146 * New BSD user-level threads support
3148 It is now possible to debug programs using the user-level threads
3149 library on OpenBSD and FreeBSD. Currently supported (target)
3152 FreeBSD/amd64 x86_64-*-freebsd*
3153 FreeBSD/i386 i386-*-freebsd*
3154 OpenBSD/i386 i386-*-openbsd*
3156 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3157 are not yet supported.
3159 * New support for Matsushita MN10300 w/sim added
3160 (Work in progress). mn10300-elf.
3162 * REMOVED configurations and files
3164 VxWorks and the XDR protocol *-*-vxworks
3165 Motorola MCORE mcore-*-*
3166 National Semiconductor NS32000 ns32k-*-*
3168 * New "set print array-indexes" command
3170 After turning this setting "on", GDB prints the index of each element
3171 when displaying arrays. The default is "off" to preserve the previous
3174 * VAX floating point support
3176 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3178 * User-defined command support
3180 In addition to using $arg0..$arg9 for argument passing, it is now possible
3181 to use $argc to determine now many arguments have been passed. See the
3182 section on user-defined commands in the user manual for more information.
3184 *** Changes in GDB 6.3:
3186 * New command line option
3188 GDB now accepts -l followed by a number to set the timeout for remote
3191 * GDB works with GCC -feliminate-dwarf2-dups
3193 GDB now supports a more compact representation of DWARF-2 debug
3194 information using DW_FORM_ref_addr references. These are produced
3195 by GCC with the option -feliminate-dwarf2-dups and also by some
3196 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3197 to use -feliminate-dwarf2-dups.
3199 * Internationalization
3201 When supported by the host system, GDB will be built with
3202 internationalization (libintl). The task of marking up the sources is
3203 continued, we're looking forward to our first translation.
3207 Initial support for debugging programs compiled with the GNAT
3208 implementation of the Ada programming language has been integrated
3209 into GDB. In this release, support is limited to expression evaluation.
3211 * New native configurations
3213 GNU/Linux/m32r m32r-*-linux-gnu
3217 GDB's remote protocol now includes support for the 'p' packet. This
3218 packet is used to fetch individual registers from a remote inferior.
3220 * END-OF-LIFE registers[] compatibility module
3222 GDB's internal register infrastructure has been completely rewritten.
3223 The new infrastructure making possible the implementation of key new
3224 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3227 GDB 6.3 will be the last release to include the the registers[]
3228 compatibility module that allowed out-of-date configurations to
3229 continue to work. This change directly impacts the following
3239 powerpc bdm protocol
3241 Unless there is activity to revive these configurations, they will be
3242 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3244 * OBSOLETE configurations and files
3246 Configurations that have been declared obsolete in this release have
3247 been commented out. Unless there is activity to revive these
3248 configurations, the next release of GDB will have their sources
3249 permanently REMOVED.
3258 *** Changes in GDB 6.2.1:
3260 * MIPS `break main; run' gave an heuristic-fence-post warning
3262 When attempting to run even a simple program, a warning about
3263 heuristic-fence-post being hit would be reported. This problem has
3266 * MIPS IRIX 'long double' crashed GDB
3268 When examining a long double variable, GDB would get a segmentation
3269 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3270 IRIX long double values).
3274 A bug in the VAX stack code was causing problems with the "next"
3275 command. This problem has been fixed.
3277 *** Changes in GDB 6.2:
3279 * Fix for ``many threads''
3281 On GNU/Linux systems that use the NPTL threads library, a program
3282 rapidly creating and deleting threads would confuse GDB leading to the
3285 ptrace: No such process.
3286 thread_db_get_info: cannot get thread info: generic error
3288 This problem has been fixed.
3290 * "-async" and "-noasync" options removed.
3292 Support for the broken "-noasync" option has been removed (it caused
3295 * New ``start'' command.
3297 This command runs the program until the begining of the main procedure.
3299 * New BSD Kernel Data Access Library (libkvm) interface
3301 Using ``target kvm'' it is now possible to debug kernel core dumps and
3302 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3303 platforms. Currently supported (native-only) configurations are:
3305 FreeBSD/amd64 x86_64-*-freebsd*
3306 FreeBSD/i386 i?86-*-freebsd*
3307 NetBSD/i386 i?86-*-netbsd*
3308 NetBSD/m68k m68*-*-netbsd*
3309 NetBSD/sparc sparc-*-netbsd*
3310 OpenBSD/amd64 x86_64-*-openbsd*
3311 OpenBSD/i386 i?86-*-openbsd*
3312 OpenBSD/m68k m68*-openbsd*
3313 OpenBSD/sparc sparc-*-openbsd*
3315 * Signal trampoline code overhauled
3317 Many generic problems with GDB's signal handling code have been fixed.
3318 These include: backtraces through non-contiguous stacks; recognition
3319 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3320 call; backtrace through a signal trampoline; step into and out of
3321 signal handlers; and single-stepping in the signal trampoline.
3323 Please note that kernel bugs are a limiting factor here. These
3324 features have been shown to work on an s390 GNU/Linux system that
3325 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3327 * Cygwin support for DWARF 2 added.
3329 * New native configurations
3331 GNU/Linux/hppa hppa*-*-linux*
3332 OpenBSD/hppa hppa*-*-openbsd*
3333 OpenBSD/m68k m68*-*-openbsd*
3334 OpenBSD/m88k m88*-*-openbsd*
3335 OpenBSD/powerpc powerpc-*-openbsd*
3336 NetBSD/vax vax-*-netbsd*
3337 OpenBSD/vax vax-*-openbsd*
3339 * END-OF-LIFE frame compatibility module
3341 GDB's internal frame infrastructure has been completely rewritten.
3342 The new infrastructure making it possible to support key new features
3343 including DWARF 2 Call Frame Information. To aid in the task of
3344 migrating old configurations to this new infrastructure, a
3345 compatibility module, that allowed old configurations to continue to
3346 work, was also included.
3348 GDB 6.2 will be the last release to include this frame compatibility
3349 module. This change directly impacts the following configurations:
3359 Unless there is activity to revive these configurations, they will be
3360 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3362 * REMOVED configurations and files
3364 Sun 3, running SunOS 3 m68*-*-sunos3*
3365 Sun 3, running SunOS 4 m68*-*-sunos4*
3366 Sun 2, running SunOS 3 m68000-*-sunos3*
3367 Sun 2, running SunOS 4 m68000-*-sunos4*
3368 Motorola 680x0 running LynxOS m68*-*-lynxos*
3369 AT&T 3b1/Unix pc m68*-att-*
3370 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3371 decstation mips-dec-* mips-little-*
3372 riscos mips-*-riscos* mips-*-sysv*
3373 sonymips mips-sony-*
3374 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3376 *** Changes in GDB 6.1.1:
3378 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3380 The TUI (Text-mode User Interface) is now built as part of a default
3381 GDB configuration. It is enabled by either selecting the TUI with the
3382 command line option "-i=tui" or by running the separate "gdbtui"
3383 program. For more information on the TUI, see the manual "Debugging
3386 * Pending breakpoint support (also included in GDB 6.1)
3388 Support has been added to allow you to specify breakpoints in shared
3389 libraries that have not yet been loaded. If a breakpoint location
3390 cannot be found, and the "breakpoint pending" option is set to auto,
3391 GDB queries you if you wish to make the breakpoint pending on a future
3392 shared-library load. If and when GDB resolves the breakpoint symbol,
3393 the pending breakpoint is removed as one or more regular breakpoints
3396 Pending breakpoints are very useful for GCJ Java debugging.
3398 * Fixed ISO-C build problems
3400 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3401 non ISO-C code that stopped them being built using a more strict ISO-C
3402 compiler (e.g., IBM's C compiler).
3404 * Fixed build problem on IRIX 5
3406 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3407 wasn't able to compile compile on an IRIX 5 system.
3409 * Added execute permission to gdb/gdbserver/configure
3411 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3412 permission. This bug would cause configure to fail on a number of
3413 systems (Solaris, IRIX). Ref: server/519.
3415 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3417 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3418 has been updated to use constant array sizes.
3420 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3422 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3423 its generated DWARF Call Frame Info. This encoding was causing GDB to
3424 panic, that panic has been fixed. Ref: gdb/1628.
3426 * Fixed a problem when examining parameters in shared library code.
3428 When examining parameters in optimized shared library code generated
3429 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3430 not available''. GDB now correctly displays the variable's value.
3432 *** Changes in GDB 6.1:
3434 * Removed --with-mmalloc
3436 Support for the mmalloc memory manager has been removed, as it
3437 conflicted with the internal gdb byte cache.
3439 * Changes in AMD64 configurations
3441 The AMD64 target now includes the %cs and %ss registers. As a result
3442 the AMD64 remote protocol has changed; this affects the floating-point
3443 and SSE registers. If you rely on those registers for your debugging,
3444 you should upgrade gdbserver on the remote side.
3446 * Revised SPARC target
3448 The SPARC target has been completely revised, incorporating the
3449 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3450 support for LynxOS and SunOS 4 has been dropped. Calling functions
3451 from within GDB on operating systems with a non-executable stack
3452 (Solaris, OpenBSD) now works.
3456 GDB has a new C++ demangler which does a better job on the mangled
3457 names generated by current versions of g++. It also runs faster, so
3458 with this and other changes gdb should now start faster on large C++
3461 * DWARF 2 Location Expressions
3463 GDB support for location expressions has been extended to support function
3464 arguments and frame bases. Older versions of GDB could crash when they
3467 * C++ nested types and namespaces
3469 GDB's support for nested types and namespaces in C++ has been
3470 improved, especially if you use the DWARF 2 debugging format. (This
3471 is the default for recent versions of GCC on most platforms.)
3472 Specifically, if you have a class "Inner" defined within a class or
3473 namespace "Outer", then GDB realizes that the class's name is
3474 "Outer::Inner", not simply "Inner". This should greatly reduce the
3475 frequency of complaints about not finding RTTI symbols. In addition,
3476 if you are stopped at inside of a function defined within a namespace,
3477 GDB modifies its name lookup accordingly.
3479 * New native configurations
3481 NetBSD/amd64 x86_64-*-netbsd*
3482 OpenBSD/amd64 x86_64-*-openbsd*
3483 OpenBSD/alpha alpha*-*-openbsd*
3484 OpenBSD/sparc sparc-*-openbsd*
3485 OpenBSD/sparc64 sparc64-*-openbsd*
3487 * New debugging protocols
3489 M32R with SDI protocol m32r-*-elf*
3491 * "set prompt-escape-char" command deleted.
3493 The command "set prompt-escape-char" has been deleted. This command,
3494 and its very obscure effet on GDB's prompt, was never documented,
3495 tested, nor mentioned in the NEWS file.
3497 * OBSOLETE configurations and files
3499 Configurations that have been declared obsolete in this release have
3500 been commented out. Unless there is activity to revive these
3501 configurations, the next release of GDB will have their sources
3502 permanently REMOVED.
3504 Sun 3, running SunOS 3 m68*-*-sunos3*
3505 Sun 3, running SunOS 4 m68*-*-sunos4*
3506 Sun 2, running SunOS 3 m68000-*-sunos3*
3507 Sun 2, running SunOS 4 m68000-*-sunos4*
3508 Motorola 680x0 running LynxOS m68*-*-lynxos*
3509 AT&T 3b1/Unix pc m68*-att-*
3510 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3511 decstation mips-dec-* mips-little-*
3512 riscos mips-*-riscos* mips-*-sysv*
3513 sonymips mips-sony-*
3514 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3516 * REMOVED configurations and files
3518 SGI Irix-4.x mips-sgi-irix4 or iris4
3519 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3520 Z8000 simulator z8k-zilog-none or z8ksim
3521 Matsushita MN10200 w/simulator mn10200-*-*
3522 H8/500 simulator h8500-hitachi-hms or h8500hms
3523 HP/PA running BSD hppa*-*-bsd*
3524 HP/PA running OSF/1 hppa*-*-osf*
3525 HP/PA Pro target hppa*-*-pro*
3526 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3527 386BSD i[3456]86-*-bsd*
3528 Sequent family i[3456]86-sequent-sysv4*
3529 i[3456]86-sequent-sysv*
3530 i[3456]86-sequent-bsd*
3531 SPARC running LynxOS sparc-*-lynxos*
3532 SPARC running SunOS 4 sparc-*-sunos4*
3533 Tsqware Sparclet sparclet-*-*
3534 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3536 *** Changes in GDB 6.0:
3540 Support for debugging the Objective-C programming language has been
3541 integrated into GDB.
3543 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3545 DWARF 2's Call Frame Information makes available compiler generated
3546 information that more exactly describes the program's run-time stack.
3547 By using this information, GDB is able to provide more robust stack
3550 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3551 have been updated to use a new backtrace mechanism which includes
3552 DWARF 2 CFI support.
3556 GDB's remote protocol has been extended to include support for hosted
3557 file I/O (where the remote target uses GDB's file system). See GDB's
3558 remote protocol documentation for details.
3560 * All targets using the new architecture framework.
3562 All of GDB's targets have been updated to use the new internal
3563 architecture framework. The way is now open for future GDB releases
3564 to include cross-architecture native debugging support (i386 on amd64,
3567 * GNU/Linux's Thread Local Storage (TLS)
3569 GDB now includes support for for the GNU/Linux implementation of
3570 per-thread variables.
3572 * GNU/Linux's Native POSIX Thread Library (NPTL)
3574 GDB's thread code has been updated to work with either the new
3575 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3577 * Separate debug info.
3579 GDB, in conjunction with BINUTILS, now supports a mechanism for
3580 automatically loading debug information from a separate file. Instead
3581 of shipping full debug and non-debug versions of system libraries,
3582 system integrators can now instead ship just the stripped libraries
3583 and optional debug files.
3585 * DWARF 2 Location Expressions
3587 DWARF 2 Location Expressions allow the compiler to more completely
3588 describe the location of variables (even in optimized code) to the
3591 GDB now includes preliminary support for location expressions (support
3592 for DW_OP_piece is still missing).
3596 A number of long standing bugs that caused GDB to die while starting a
3597 Java application have been fixed. GDB's Java support is now
3598 considered "useable".
3600 * GNU/Linux support for fork, vfork, and exec.
3602 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3603 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3606 * GDB supports logging output to a file
3608 There are two new commands, "set logging" and "show logging", which can be
3609 used to capture GDB's output to a file.
3611 * The meaning of "detach" has changed for gdbserver
3613 The "detach" command will now resume the application, as documented. To
3614 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3617 * d10v, m68hc11 `regs' command deprecated
3619 The `info registers' command has been updated so that it displays the
3620 registers using a format identical to the old `regs' command.
3624 A new command, "maint set profile on/off", has been added. This command can
3625 be used to enable or disable profiling while running GDB, to profile a
3626 session or a set of commands. In addition there is a new configure switch,
3627 "--enable-profiling", which will cause GDB to be compiled with profiling
3628 data, for more informative profiling results.
3630 * Default MI syntax changed to "mi2".
3632 The default MI (machine interface) syntax, enabled by the command line
3633 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3634 "mi1", can be enabled by specifying the option "-i=mi1".
3636 Support for the original "mi0" syntax (included in GDB 5.0) has been
3639 Fix for gdb/192: removed extraneous space when displaying frame level.
3640 Fix for gdb/672: update changelist is now output in mi list format.
3641 Fix for gdb/702: a -var-assign that updates the value now shows up
3642 in a subsequent -var-update.
3644 * New native configurations.
3646 FreeBSD/amd64 x86_64-*-freebsd*
3648 * Multi-arched targets.
3650 HP/PA HPUX11 hppa*-*-hpux*
3651 Renesas M32R/D w/simulator m32r-*-elf*
3653 * OBSOLETE configurations and files
3655 Configurations that have been declared obsolete in this release have
3656 been commented out. Unless there is activity to revive these
3657 configurations, the next release of GDB will have their sources
3658 permanently REMOVED.
3660 Z8000 simulator z8k-zilog-none or z8ksim
3661 Matsushita MN10200 w/simulator mn10200-*-*
3662 H8/500 simulator h8500-hitachi-hms or h8500hms
3663 HP/PA running BSD hppa*-*-bsd*
3664 HP/PA running OSF/1 hppa*-*-osf*
3665 HP/PA Pro target hppa*-*-pro*
3666 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3667 Sequent family i[3456]86-sequent-sysv4*
3668 i[3456]86-sequent-sysv*
3669 i[3456]86-sequent-bsd*
3670 Tsqware Sparclet sparclet-*-*
3671 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3673 * REMOVED configurations and files
3676 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3677 IBM AIX PS/2 i[3456]86-*-aix
3678 i386 running Mach 3.0 i[3456]86-*-mach3*
3679 i386 running Mach i[3456]86-*-mach*
3680 i386 running OSF/1 i[3456]86-*osf1mk*
3681 HP/Apollo 68k Family m68*-apollo*-sysv*,
3683 m68*-hp-bsd*, m68*-hp-hpux*
3684 Argonaut Risc Chip (ARC) arc-*-*
3685 Mitsubishi D30V d30v-*-*
3686 Fujitsu FR30 fr30-*-elf*
3687 OS/9000 i[34]86-*-os9k
3688 I960 with MON960 i960-*-coff
3690 * MIPS $fp behavior changed
3692 The convenience variable $fp, for the MIPS, now consistently returns
3693 the address of the current frame's base. Previously, depending on the
3694 context, $fp could refer to either $sp or the current frame's base
3695 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3696 The GNU Source-Level Debugger''.
3698 *** Changes in GDB 5.3:
3700 * GNU/Linux shared library multi-threaded performance improved.
3702 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3703 `/proc', in preference to `ptrace' for memory reads. This may result
3704 in an improvement in the start-up time of multi-threaded, shared
3705 library applications when run under GDB. One GDB user writes: ``loads
3706 shared libs like mad''.
3708 * ``gdbserver'' now supports multi-threaded applications on some targets
3710 Support for debugging multi-threaded applications which use
3711 the GNU/Linux LinuxThreads package has been added for
3712 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3713 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3715 * GDB now supports C/C++ preprocessor macros.
3717 GDB now expands preprocessor macro invocations in C/C++ expressions,
3718 and provides various commands for showing macro definitions and how
3721 The new command `macro expand EXPRESSION' expands any macro
3722 invocations in expression, and shows the result.
3724 The new command `show macro MACRO-NAME' shows the definition of the
3725 macro named MACRO-NAME, and where it was defined.
3727 Most compilers don't include information about macros in the debugging
3728 information by default. In GCC 3.1, for example, you need to compile
3729 your program with the options `-gdwarf-2 -g3'. If the macro
3730 information is present in the executable, GDB will read it.
3732 * Multi-arched targets.
3734 DEC Alpha (partial) alpha*-*-*
3735 DEC VAX (partial) vax-*-*
3737 National Semiconductor NS32000 (partial) ns32k-*-*
3738 Motorola 68000 (partial) m68k-*-*
3739 Motorola MCORE mcore-*-*
3743 Fujitsu FRV architecture added by Red Hat frv*-*-*
3746 * New native configurations
3748 Alpha NetBSD alpha*-*-netbsd*
3749 SH NetBSD sh*-*-netbsdelf*
3750 MIPS NetBSD mips*-*-netbsd*
3751 UltraSPARC NetBSD sparc64-*-netbsd*
3753 * OBSOLETE configurations and files
3755 Configurations that have been declared obsolete in this release have
3756 been commented out. Unless there is activity to revive these
3757 configurations, the next release of GDB will have their sources
3758 permanently REMOVED.
3760 Mitsubishi D30V d30v-*-*
3761 OS/9000 i[34]86-*-os9k
3762 IBM AIX PS/2 i[3456]86-*-aix
3763 Fujitsu FR30 fr30-*-elf*
3764 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3765 Argonaut Risc Chip (ARC) arc-*-*
3766 i386 running Mach 3.0 i[3456]86-*-mach3*
3767 i386 running Mach i[3456]86-*-mach*
3768 i386 running OSF/1 i[3456]86-*osf1mk*
3769 HP/Apollo 68k Family m68*-apollo*-sysv*,
3771 m68*-hp-bsd*, m68*-hp-hpux*
3772 I960 with MON960 i960-*-coff
3774 * OBSOLETE languages
3776 CHILL, a Pascal like language used by telecommunications companies.
3778 * REMOVED configurations and files
3780 AMD 29k family via UDI a29k-amd-udi, udi29k
3781 A29K VxWorks a29k-*-vxworks
3782 AMD 29000 embedded, using EBMON a29k-none-none
3783 AMD 29000 embedded with COFF a29k-none-coff
3784 AMD 29000 embedded with a.out a29k-none-aout
3786 testsuite/gdb.hp/gdb.threads-hp/ directory
3788 * New command "set max-user-call-depth <nnn>"
3790 This command allows the user to limit the call depth of user-defined
3791 commands. The default is 1024.
3793 * Changes in FreeBSD/i386 native debugging.
3795 Support for the "generate-core-file" has been added.
3797 * New commands "dump", "append", and "restore".
3799 These commands allow data to be copied from target memory
3800 to a bfd-format or binary file (dump and append), and back
3801 from a file into memory (restore).
3803 * Improved "next/step" support on multi-processor Alpha Tru64.
3805 The previous single-step mechanism could cause unpredictable problems,
3806 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3807 of a software single-step mechanism prevents this.
3809 *** Changes in GDB 5.2.1:
3817 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3818 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3819 Fix, by Joel Brobecker imported from mainline.
3821 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3822 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3823 Fix, by Fred Fish, imported from mainline.
3825 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3826 Surprisingly enough, it works now.
3827 By Michal Ludvig, imported from mainline.
3829 i386 hardware watchpoint support:
3830 avoid misses on second run for some targets.
3831 By Pierre Muller, imported from mainline.
3833 *** Changes in GDB 5.2:
3835 * New command "set trust-readonly-sections on[off]".
3837 This command is a hint that tells gdb that read-only sections
3838 really are read-only (ie. that their contents will not change).
3839 In this mode, gdb will go to the object file rather than the
3840 target to read memory from read-only sections (such as ".text").
3841 This can be a significant performance improvement on some
3842 (notably embedded) targets.
3844 * New command "generate-core-file" (or "gcore").
3846 This new gdb command allows the user to drop a core file of the child
3847 process state at any time. So far it's been implemented only for
3848 GNU/Linux and Solaris, but should be relatively easily ported to other
3849 hosts. Argument is core file name (defaults to core.<pid>).
3851 * New command line option
3853 GDB now accepts --pid or -p followed by a process id.
3855 * Change in command line behavior -- corefiles vs. process ids.
3857 There is a subtle behavior in the way in which GDB handles
3858 command line arguments. The first non-flag argument is always
3859 a program to debug, but the second non-flag argument may either
3860 be a corefile or a process id. Previously, GDB would attempt to
3861 open the second argument as a corefile, and if that failed, would
3862 issue a superfluous error message and then attempt to attach it as
3863 a process. Now, if the second argument begins with a non-digit,
3864 it will be treated as a corefile. If it begins with a digit,
3865 GDB will attempt to attach it as a process, and if no such process
3866 is found, will then attempt to open it as a corefile.
3868 * Changes in ARM configurations.
3870 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3871 configuration is fully multi-arch.
3873 * New native configurations
3875 ARM NetBSD arm*-*-netbsd*
3876 x86 OpenBSD i[3456]86-*-openbsd*
3877 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3878 Sparc64 running FreeBSD sparc64-*-freebsd*
3882 Sanyo XStormy16 xstormy16-elf
3884 * OBSOLETE configurations and files
3886 Configurations that have been declared obsolete in this release have
3887 been commented out. Unless there is activity to revive these
3888 configurations, the next release of GDB will have their sources
3889 permanently REMOVED.
3891 AMD 29k family via UDI a29k-amd-udi, udi29k
3892 A29K VxWorks a29k-*-vxworks
3893 AMD 29000 embedded, using EBMON a29k-none-none
3894 AMD 29000 embedded with COFF a29k-none-coff
3895 AMD 29000 embedded with a.out a29k-none-aout
3897 testsuite/gdb.hp/gdb.threads-hp/ directory
3899 * REMOVED configurations and files
3901 TI TMS320C80 tic80-*-*
3903 PowerPC Solaris powerpcle-*-solaris*
3904 PowerPC Windows NT powerpcle-*-cygwin32
3905 PowerPC Netware powerpc-*-netware*
3906 Harris/CXUX m88k m88*-harris-cxux*
3907 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3908 ns32k-utek-sysv* ns32k-utek-*
3909 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3910 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3911 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3912 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3913 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3915 * Changes to command line processing
3917 The new `--args' feature can be used to specify command-line arguments
3918 for the inferior from gdb's command line.
3920 * Changes to key bindings
3922 There is a new `operate-and-get-next' function bound to `C-o'.
3924 *** Changes in GDB 5.1.1
3926 Fix compile problem on DJGPP.
3928 Fix a problem with floating-point registers on the i386 being
3931 Fix to stop GDB crashing on .debug_str debug info.
3933 Numerous documentation fixes.
3935 Numerous testsuite fixes.
3937 *** Changes in GDB 5.1:
3939 * New native configurations
3941 Alpha FreeBSD alpha*-*-freebsd*
3942 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3943 MIPS GNU/Linux mips*-*-linux*
3944 MIPS SGI Irix 6.x mips*-sgi-irix6*
3945 ia64 AIX ia64-*-aix*
3946 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3950 Motorola 68HC11 and 68HC12 m68hc11-elf
3952 UltraSparc running GNU/Linux sparc64-*-linux*
3954 * OBSOLETE configurations and files
3956 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3957 Harris/CXUX m88k m88*-harris-cxux*
3958 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3959 ns32k-utek-sysv* ns32k-utek-*
3960 TI TMS320C80 tic80-*-*
3962 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3963 PowerPC Solaris powerpcle-*-solaris*
3964 PowerPC Windows NT powerpcle-*-cygwin32
3965 PowerPC Netware powerpc-*-netware*
3966 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3967 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3968 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3969 Apple Macintosh (MPW) host N/A
3971 stuff.c (Program to stuff files into a specially prepared space in kdb)
3972 kdb-start.c (Main loop for the standalone kernel debugger)
3974 Configurations that have been declared obsolete in this release have
3975 been commented out. Unless there is activity to revive these
3976 configurations, the next release of GDB will have their sources
3977 permanently REMOVED.
3979 * REMOVED configurations and files
3981 Altos 3068 m68*-altos-*
3982 Convex c1-*-*, c2-*-*
3984 ARM RISCix arm-*-* (as host)
3988 * GDB has been converted to ISO C.
3990 GDB's source code has been converted to ISO C. In particular, the
3991 sources are fully protoized, and rely on standard headers being
3996 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3998 * The MI enabled by default.
4000 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4001 revised and enabled by default. Packages which use GDB as a debugging
4002 engine behind a UI or another front end are encouraged to switch to
4003 using the GDB/MI interface, instead of the old annotations interface
4004 which is now deprecated.
4006 * Support for debugging Pascal programs.
4008 GDB now includes support for debugging Pascal programs. The following
4009 main features are supported:
4011 - Pascal-specific data types such as sets;
4013 - automatic recognition of Pascal sources based on file-name
4016 - Pascal-style display of data types, variables, and functions;
4018 - a Pascal expression parser.
4020 However, some important features are not yet supported.
4022 - Pascal string operations are not supported at all;
4024 - there are some problems with boolean types;
4026 - Pascal type hexadecimal constants are not supported
4027 because they conflict with the internal variables format;
4029 - support for Pascal objects and classes is not full yet;
4031 - unlike Pascal, GDB is case-sensitive for symbol names.
4033 * Changes in completion.
4035 Commands such as `shell', `run' and `set args', which pass arguments
4036 to inferior programs, now complete on file names, similar to what
4037 users expect at the shell prompt.
4039 Commands which accept locations, such as `disassemble', `print',
4040 `breakpoint', `until', etc. now complete on filenames as well as
4041 program symbols. Thus, if you type "break foob TAB", and the source
4042 files linked into the programs include `foobar.c', that file name will
4043 be one of the candidates for completion. However, file names are not
4044 considered for completion after you typed a colon that delimits a file
4045 name from a name of a function in that file, as in "break foo.c:bar".
4047 `set demangle-style' completes on available demangling styles.
4049 * New platform-independent commands:
4051 It is now possible to define a post-hook for a command as well as a
4052 hook that runs before the command. For more details, see the
4053 documentation of `hookpost' in the GDB manual.
4055 * Changes in GNU/Linux native debugging.
4057 Support for debugging multi-threaded programs has been completely
4058 revised for all platforms except m68k and sparc. You can now debug as
4059 many threads as your system allows you to have.
4061 Attach/detach is supported for multi-threaded programs.
4063 Support for SSE registers was added for x86. This doesn't work for
4064 multi-threaded programs though.
4066 * Changes in MIPS configurations.
4068 Multi-arch support is enabled for all MIPS configurations.
4070 GDB can now be built as native debugger on SGI Irix 6.x systems for
4071 debugging n32 executables. (Debugging 64-bit executables is not yet
4074 * Unified support for hardware watchpoints in all x86 configurations.
4076 Most (if not all) native x86 configurations support hardware-assisted
4077 breakpoints and watchpoints in a unified manner. This support
4078 implements debug register sharing between watchpoints, which allows to
4079 put a virtually infinite number of watchpoints on the same address,
4080 and also supports watching regions up to 16 bytes with several debug
4083 The new maintenance command `maintenance show-debug-regs' toggles
4084 debugging print-outs in functions that insert, remove, and test
4085 watchpoints and hardware breakpoints.
4087 * Changes in the DJGPP native configuration.
4089 New command ``info dos sysinfo'' displays assorted information about
4090 the CPU, OS, memory, and DPMI server.
4092 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4093 display information about segment descriptors stored in GDT, LDT, and
4096 New commands ``info dos pde'' and ``info dos pte'' display entries
4097 from Page Directory and Page Tables (for now works with CWSDPMI only).
4098 New command ``info dos address-pte'' displays the Page Table entry for
4099 a given linear address.
4101 GDB can now pass command lines longer than 126 characters to the
4102 program being debugged (requires an update to the libdbg.a library
4103 which is part of the DJGPP development kit).
4105 DWARF2 debug info is now supported.
4107 It is now possible to `step' and `next' through calls to `longjmp'.
4109 * Changes in documentation.
4111 All GDB documentation was converted to GFDL, the GNU Free
4112 Documentation License.
4114 Tracepoints-related commands are now fully documented in the GDB
4117 TUI, the Text-mode User Interface, is now documented in the manual.
4119 Tracepoints-related commands are now fully documented in the GDB
4122 The "GDB Internals" manual now has an index. It also includes
4123 documentation of `ui_out' functions, GDB coding standards, x86
4124 hardware watchpoints, and memory region attributes.
4126 * GDB's version number moved to ``version.in''
4128 The Makefile variable VERSION has been replaced by the file
4129 ``version.in''. People creating GDB distributions should update the
4130 contents of this file.
4134 GUD support is now a standard part of the EMACS distribution.
4136 *** Changes in GDB 5.0:
4138 * Improved support for debugging FP programs on x86 targets
4140 Unified and much-improved support for debugging floating-point
4141 programs on all x86 targets. In particular, ``info float'' now
4142 displays the FP registers in the same format on all x86 targets, with
4143 greater level of detail.
4145 * Improvements and bugfixes in hardware-assisted watchpoints
4147 It is now possible to watch array elements, struct members, and
4148 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4149 on x86 targets no longer erroneously trigger when the address is
4152 * Improvements in the native DJGPP version of GDB
4154 The distribution now includes all the scripts and auxiliary files
4155 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4156 machines ``out of the box''.
4158 The DJGPP version can now debug programs that use signals. It is
4159 possible to catch signals that happened in the debuggee, deliver
4160 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4161 would kill the program being debugged.) Programs that hook hardware
4162 interrupts (keyboard, timer, etc.) can also be debugged.
4164 It is now possible to debug DJGPP programs that redirect their
4165 standard handles or switch them to raw (as opposed to cooked) mode, or
4166 even close them. The command ``run < foo > bar'' works as expected,
4167 and ``info terminal'' reports useful information about the debuggee's
4168 terminal, including raw/cooked mode, redirection, etc.
4170 The DJGPP version now uses termios functions for console I/O, which
4171 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4174 DOS-style file names with drive letters are now fully supported by
4177 It is now possible to debug DJGPP programs that switch their working
4178 directory. It is also possible to rerun the debuggee any number of
4179 times without restarting GDB; thus, you can use the same setup,
4180 breakpoints, etc. for many debugging sessions.
4182 * New native configurations
4184 ARM GNU/Linux arm*-*-linux*
4185 PowerPC GNU/Linux powerpc-*-linux*
4189 Motorola MCore mcore-*-*
4190 x86 VxWorks i[3456]86-*-vxworks*
4191 PowerPC VxWorks powerpc-*-vxworks*
4192 TI TMS320C80 tic80-*-*
4194 * OBSOLETE configurations
4196 Altos 3068 m68*-altos-*
4197 Convex c1-*-*, c2-*-*
4199 ARM RISCix arm-*-* (as host)
4202 Configurations that have been declared obsolete will be commented out,
4203 but the code will be left in place. If there is no activity to revive
4204 these configurations before the next release of GDB, the sources will
4205 be permanently REMOVED.
4207 * Gould support removed
4209 Support for the Gould PowerNode and NP1 has been removed.
4211 * New features for SVR4
4213 On SVR4 native platforms (such as Solaris), if you attach to a process
4214 without first loading a symbol file, GDB will now attempt to locate and
4215 load symbols from the running process's executable file.
4217 * Many C++ enhancements
4219 C++ support has been greatly improved. Overload resolution now works properly
4220 in almost all cases. RTTI support is on the way.
4222 * Remote targets can connect to a sub-program
4224 A popen(3) style serial-device has been added. This device starts a
4225 sub-process (such as a stand-alone simulator) and then communicates
4226 with that. The sub-program to run is specified using the syntax
4227 ``|<program> <args>'' vis:
4229 (gdb) set remotedebug 1
4230 (gdb) target extended-remote |mn10300-elf-sim program-args
4232 * MIPS 64 remote protocol
4234 A long standing bug in the mips64 remote protocol where by GDB
4235 expected certain 32 bit registers (ex SR) to be transfered as 32
4236 instead of 64 bits has been fixed.
4238 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4239 added to provide backward compatibility with older versions of GDB.
4241 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4243 The command ``set remotebinarydownload'' command has been replaced by
4244 ``set remote X-packet''. Other commands in ``set remote'' family
4245 include ``set remote P-packet''.
4247 * Breakpoint commands accept ranges.
4249 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4250 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4251 ``tracepoint passcount'' also accepts a range of tracepoints.
4253 * ``apropos'' command added.
4255 The ``apropos'' command searches through command names and
4256 documentation strings, printing out matches, making it much easier to
4257 try to find a command that does what you are looking for.
4261 A new machine oriented interface (MI) has been added to GDB. This
4262 interface is designed for debug environments running GDB as a separate
4263 process. This is part of the long term libGDB project. See the
4264 "GDB/MI" chapter of the GDB manual for further information. It can be
4265 enabled by configuring with:
4267 .../configure --enable-gdbmi
4269 *** Changes in GDB-4.18:
4271 * New native configurations
4273 HP-UX 10.20 hppa*-*-hpux10.20
4274 HP-UX 11.x hppa*-*-hpux11.0*
4275 M68K GNU/Linux m68*-*-linux*
4279 Fujitsu FR30 fr30-*-elf*
4280 Intel StrongARM strongarm-*-*
4281 Mitsubishi D30V d30v-*-*
4283 * OBSOLETE configurations
4285 Gould PowerNode, NP1 np1-*-*, pn-*-*
4287 Configurations that have been declared obsolete will be commented out,
4288 but the code will be left in place. If there is no activity to revive
4289 these configurations before the next release of GDB, the sources will
4290 be permanently REMOVED.
4294 As a compatibility experiment, GDB's source files buildsym.h and
4295 buildsym.c have been converted to pure standard C, no longer
4296 containing any K&R compatibility code. We believe that all systems in
4297 use today either come with a standard C compiler, or have a GCC port
4298 available. If this is not true, please report the affected
4299 configuration to bug-gdb@gnu.org immediately. See the README file for
4300 information about getting a standard C compiler if you don't have one
4305 GDB now uses readline 2.2.
4307 * set extension-language
4309 You can now control the mapping between filename extensions and source
4310 languages by using the `set extension-language' command. For instance,
4311 you can ask GDB to treat .c files as C++ by saying
4312 set extension-language .c c++
4313 The command `info extensions' lists all of the recognized extensions
4314 and their associated languages.
4316 * Setting processor type for PowerPC and RS/6000
4318 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4319 you can use the `set processor' command to specify what variant of the
4320 PowerPC family you are debugging. The command
4324 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4325 following PowerPC and RS6000 variants:
4327 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4328 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4330 403GC IBM PowerPC 403GC
4331 505 Motorola PowerPC 505
4332 860 Motorola PowerPC 860 or 850
4333 601 Motorola PowerPC 601
4334 602 Motorola PowerPC 602
4335 603 Motorola/IBM PowerPC 603 or 603e
4336 604 Motorola PowerPC 604 or 604e
4337 750 Motorola/IBM PowerPC 750 or 750
4339 At the moment, this command just tells GDB what to name the
4340 special-purpose processor registers. Since almost all the affected
4341 registers are inaccessible to user-level programs, this command is
4342 only useful for remote debugging in its present form.
4346 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4347 more extensive support for HP-UX. Added features include shared
4348 library support, kernel threads and hardware watchpoints for 11.00,
4349 support for HP's ANSI C and C++ compilers, and a compatibility mode
4350 for xdb and dbx commands.
4354 HP's donation includes the new concept of catchpoints, which is a
4355 generalization of the old catch command. On HP-UX, it is now possible
4356 to catch exec, fork, and vfork, as well as library loading.
4358 This means that the existing catch command has changed; its first
4359 argument now specifies the type of catch to be set up. See the
4360 output of "help catch" for a list of catchpoint types.
4362 * Debugging across forks
4364 On HP-UX, you can choose which process to debug when a fork() happens
4369 HP has donated a curses-based terminal user interface (TUI). To get
4370 it, build with --enable-tui. Although this can be enabled for any
4371 configuration, at present it only works for native HP debugging.
4373 * GDB remote protocol additions
4375 A new protocol packet 'X' that writes binary data is now available.
4376 Default behavior is to try 'X', then drop back to 'M' if the stub
4377 fails to respond. The settable variable `remotebinarydownload'
4378 allows explicit control over the use of 'X'.
4380 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4381 full 64-bit address. The command
4383 set remoteaddresssize 32
4385 can be used to revert to the old behaviour. For existing remote stubs
4386 the change should not be noticed, as the additional address information
4389 In order to assist in debugging stubs, you may use the maintenance
4390 command `packet' to send any text string to the stub. For instance,
4392 maint packet heythere
4394 sends the packet "$heythere#<checksum>". Note that it is very easy to
4395 disrupt a debugging session by sending the wrong packet at the wrong
4398 The compare-sections command allows you to compare section data on the
4399 target to what is in the executable file without uploading or
4400 downloading, by comparing CRC checksums.
4402 * Tracing can collect general expressions
4404 You may now collect general expressions at tracepoints. This requires
4405 further additions to the target-side stub; see tracepoint.c and
4406 doc/agentexpr.texi for further details.
4408 * mask-address variable for Mips
4410 For Mips targets, you may control the zeroing of the upper 32 bits of
4411 a 64-bit address by entering `set mask-address on'. This is mainly
4412 of interest to users of embedded R4xxx and R5xxx processors.
4414 * Higher serial baud rates
4416 GDB's serial code now allows you to specify baud rates 57600, 115200,
4417 230400, and 460800 baud. (Note that your host system may not be able
4418 to achieve all of these rates.)
4422 The i960 configuration now includes an initial implementation of a
4423 builtin simulator, contributed by Jim Wilson.
4426 *** Changes in GDB-4.17:
4428 * New native configurations
4430 Alpha GNU/Linux alpha*-*-linux*
4431 Unixware 2.x i[3456]86-unixware2*
4432 Irix 6.x mips*-sgi-irix6*
4433 PowerPC GNU/Linux powerpc-*-linux*
4434 PowerPC Solaris powerpcle-*-solaris*
4435 Sparc GNU/Linux sparc-*-linux*
4436 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4440 Argonaut Risc Chip (ARC) arc-*-*
4441 Hitachi H8/300S h8300*-*-*
4442 Matsushita MN10200 w/simulator mn10200-*-*
4443 Matsushita MN10300 w/simulator mn10300-*-*
4444 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4445 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4446 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4447 Mitsubishi D10V w/simulator d10v-*-*
4448 Mitsubishi M32R/D w/simulator m32r-*-elf*
4449 Tsqware Sparclet sparclet-*-*
4450 NEC V850 w/simulator v850-*-*
4452 * New debugging protocols
4454 ARM with RDI protocol arm*-*-*
4455 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4456 DDB and LSI variants of PMON protocol mips*-*-*
4457 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4458 PowerPC with SDS protocol powerpc{,le}-*-eabi
4459 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4463 All configurations can now understand and use the DWARF 2 debugging
4464 format. The choice is automatic, if the symbol file contains DWARF 2
4469 GDB now includes basic Java language support. This support is
4470 only useful with Java compilers that produce native machine code.
4472 * solib-absolute-prefix and solib-search-path
4474 For SunOS and SVR4 shared libraries, you may now set the prefix for
4475 loading absolute shared library symbol files, and the search path for
4476 locating non-absolute shared library symbol files.
4478 * Live range splitting
4480 GDB can now effectively debug code for which GCC has performed live
4481 range splitting as part of its optimization. See gdb/doc/LRS for
4482 more details on the expected format of the stabs information.
4486 GDB's support for the GNU Hurd, including thread debugging, has been
4487 updated to work with current versions of the Hurd.
4491 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4492 instruction set. ARM GDB automatically detects when Thumb
4493 instructions are in use, and adjusts disassembly and backtracing
4498 GDB's MIPS target configurations now handle the MIP16 16-bit
4503 GDB now includes support for overlays; if an executable has been
4504 linked such that multiple sections are based at the same address, GDB
4505 will decide which section to use for symbolic info. You can choose to
4506 control the decision manually, using overlay commands, or implement
4507 additional target-side support and use "overlay load-target" to bring
4508 in the overlay mapping. Do "help overlay" for more detail.
4512 The command "info symbol <address>" displays information about
4513 the symbol at the specified address.
4517 The standard remote protocol now includes an extension that allows
4518 asynchronous collection and display of trace data. This requires
4519 extensive support in the target-side debugging stub. Tracing mode
4520 includes a new interaction mode in GDB and new commands: see the
4521 file tracepoint.c for more details.
4525 Configurations for embedded MIPS now include a simulator contributed
4526 by Cygnus Solutions. The simulator supports the instruction sets
4527 of most MIPS variants.
4531 Sparc configurations may now include the ERC32 simulator contributed
4532 by the European Space Agency. The simulator is not built into
4533 Sparc targets by default; configure with --enable-sim to include it.
4537 For target configurations that may include multiple variants of a
4538 basic architecture (such as MIPS and SH), you may now set the
4539 architecture explicitly. "set arch" sets, "info arch" lists
4540 the possible architectures.
4542 *** Changes in GDB-4.16:
4544 * New native configurations
4546 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4547 M68K NetBSD m68k-*-netbsd*
4548 PowerPC AIX 4.x powerpc-*-aix*
4549 PowerPC MacOS powerpc-*-macos*
4550 PowerPC Windows NT powerpcle-*-cygwin32
4551 RS/6000 AIX 4.x rs6000-*-aix4*
4555 ARM with RDP protocol arm-*-*
4556 I960 with MON960 i960-*-coff
4557 MIPS VxWorks mips*-*-vxworks*
4558 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4559 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4561 Matra Sparclet sparclet-*-*
4565 The powerpc-eabi configuration now includes the PSIM simulator,
4566 contributed by Andrew Cagney, with assistance from Mike Meissner.
4567 PSIM is a very elaborate model of the PowerPC, including not only
4568 basic instruction set execution, but also details of execution unit
4569 performance and I/O hardware. See sim/ppc/README for more details.
4573 GDB now works with Solaris 2.5.
4575 * Windows 95/NT native
4577 GDB will now work as a native debugger on Windows 95 and Windows NT.
4578 To build it from source, you must use the "gnu-win32" environment,
4579 which uses a DLL to emulate enough of Unix to run the GNU tools.
4580 Further information, binaries, and sources are available at
4581 ftp.cygnus.com, under pub/gnu-win32.
4583 * dont-repeat command
4585 If a user-defined command includes the command `dont-repeat', then the
4586 command will not be repeated if the user just types return. This is
4587 useful if the command is time-consuming to run, so that accidental
4588 extra keystrokes don't run the same command many times.
4590 * Send break instead of ^C
4592 The standard remote protocol now includes an option to send a break
4593 rather than a ^C to the target in order to interrupt it. By default,
4594 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4596 * Remote protocol timeout
4598 The standard remote protocol includes a new variable `remotetimeout'
4599 that allows you to set the number of seconds before GDB gives up trying
4600 to read from the target. The default value is 2.
4602 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4604 By default GDB will automatically keep track of objects as they are
4605 loaded and unloaded by the dynamic linker. By using the command `set
4606 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4607 when shared library events occur, thus allowing you to set breakpoints
4608 in shared libraries which are explicitly loaded by the inferior.
4610 Note this feature does not work on hpux8. On hpux9 you must link
4611 /usr/lib/end.o into your program. This feature should work
4612 automatically on hpux10.
4614 * Irix 5.x hardware watchpoint support
4616 Irix 5 configurations now support the use of hardware watchpoints.
4618 * Mips protocol "SYN garbage limit"
4620 When debugging a Mips target using the `target mips' protocol, you
4621 may set the number of characters that GDB will ignore by setting
4622 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4623 every character. The default value is 1050.
4625 * Recording and replaying remote debug sessions
4627 If you set `remotelogfile' to the name of a file, gdb will write to it
4628 a recording of a remote debug session. This recording may then be
4629 replayed back to gdb using "gdbreplay". See gdbserver/README for
4630 details. This is useful when you have a problem with GDB while doing
4631 remote debugging; you can make a recording of the session and send it
4632 to someone else, who can then recreate the problem.
4634 * Speedups for remote debugging
4636 GDB includes speedups for downloading and stepping MIPS systems using
4637 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4638 and more efficient S-record downloading.
4640 * Memory use reductions and statistics collection
4642 GDB now uses less memory and reports statistics about memory usage.
4643 Try the `maint print statistics' command, for example.
4645 *** Changes in GDB-4.15:
4647 * Psymtabs for XCOFF
4649 The symbol reader for AIX GDB now uses partial symbol tables. This
4650 can greatly improve startup time, especially for large executables.
4652 * Remote targets use caching
4654 Remote targets now use a data cache to speed up communication with the
4655 remote side. The data cache could lead to incorrect results because
4656 it doesn't know about volatile variables, thus making it impossible to
4657 debug targets which use memory mapped I/O devices. `set remotecache
4658 off' turns the the data cache off.
4660 * Remote targets may have threads
4662 The standard remote protocol now includes support for multiple threads
4663 in the target system, using new protocol commands 'H' and 'T'. See
4664 gdb/remote.c for details.
4668 If GDB is configured with `--enable-netrom', then it will include
4669 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4670 acts as though it is a bank of ROM on the target board, but you can
4671 write into it over the network. GDB's support consists only of
4672 support for fast loading into the emulated ROM; to debug, you must use
4673 another protocol, such as standard remote protocol. The usual
4674 sequence is something like
4676 target nrom <netrom-hostname>
4678 target remote <netrom-hostname>:1235
4682 GDB now includes support for the Apple Macintosh, as a host only. It
4683 may be run as either an MPW tool or as a standalone application, and
4684 it can debug through the serial port. All the usual GDB commands are
4685 available, but to the target command, you must supply "serial" as the
4686 device type instead of "/dev/ttyXX". See mpw-README in the main
4687 directory for more information on how to build. The MPW configuration
4688 scripts */mpw-config.in support only a few targets, and only the
4689 mips-idt-ecoff target has been tested.
4693 GDB configuration now uses autoconf. This is not user-visible,
4694 but does simplify configuration and building.
4698 GDB now supports hpux10.
4700 *** Changes in GDB-4.14:
4702 * New native configurations
4704 x86 FreeBSD i[345]86-*-freebsd
4705 x86 NetBSD i[345]86-*-netbsd
4706 NS32k NetBSD ns32k-*-netbsd
4707 Sparc NetBSD sparc-*-netbsd
4711 A29K VxWorks a29k-*-vxworks
4712 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4713 CPU32 EST-300 emulator m68*-*-est*
4714 PowerPC ELF powerpc-*-elf
4717 * Alpha OSF/1 support for procfs
4719 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4720 possible to attach to running processes. As the mounting of the /proc
4721 filesystem is optional on the Alpha, GDB automatically determines
4722 the availability of /proc during startup. This can lead to problems
4723 if /proc is unmounted after GDB has been started.
4725 * Arguments to user-defined commands
4727 User commands may accept up to 10 arguments separated by whitespace.
4728 Arguments are accessed within the user command via $arg0..$arg9. A
4731 print $arg0 + $arg1 + $arg2
4733 To execute the command use:
4736 Defines the command "adder" which prints the sum of its three arguments.
4737 Note the arguments are text substitutions, so they may reference variables,
4738 use complex expressions, or even perform inferior function calls.
4740 * New `if' and `while' commands
4742 This makes it possible to write more sophisticated user-defined
4743 commands. Both commands take a single argument, which is the
4744 expression to evaluate, and must be followed by the commands to
4745 execute, one per line, if the expression is nonzero, the list being
4746 terminated by the word `end'. The `if' command list may include an
4747 `else' word, which causes the following commands to be executed only
4748 if the expression is zero.
4750 * Fortran source language mode
4752 GDB now includes partial support for Fortran 77. It will recognize
4753 Fortran programs and can evaluate a subset of Fortran expressions, but
4754 variables and functions may not be handled correctly. GDB will work
4755 with G77, but does not yet know much about symbols emitted by other
4758 * Better HPUX support
4760 Most debugging facilities now work on dynamic executables for HPPAs
4761 running hpux9 or later. You can attach to running dynamically linked
4762 processes, but by default the dynamic libraries will be read-only, so
4763 for instance you won't be able to put breakpoints in them. To change
4764 that behavior do the following before running the program:
4770 This will cause the libraries to be mapped private and read-write.
4771 To revert to the normal behavior, do this:
4777 You cannot set breakpoints or examine data in the library until after
4778 the library is loaded if the function/data symbols do not have
4781 GDB can now also read debug symbols produced by the HP C compiler on
4782 HPPAs (sorry, no C++, Fortran or 68k support).
4784 * Target byte order now dynamically selectable
4786 You can choose which byte order to use with a target system, via the
4787 commands "set endian big" and "set endian little", and you can see the
4788 current setting by using "show endian". You can also give the command
4789 "set endian auto", in which case GDB will use the byte order
4790 associated with the executable. Currently, only embedded MIPS
4791 configurations support dynamic selection of target byte order.
4793 * New DOS host serial code
4795 This version uses DPMI interrupts to handle buffered I/O, so you
4796 no longer need to run asynctsr when debugging boards connected to
4799 *** Changes in GDB-4.13:
4801 * New "complete" command
4803 This lists all the possible completions for the rest of the line, if it
4804 were to be given as a command itself. This is intended for use by emacs.
4806 * Trailing space optional in prompt
4808 "set prompt" no longer adds a space for you after the prompt you set. This
4809 allows you to set a prompt which ends in a space or one that does not.
4811 * Breakpoint hit counts
4813 "info break" now displays a count of the number of times the breakpoint
4814 has been hit. This is especially useful in conjunction with "ignore"; you
4815 can ignore a large number of breakpoint hits, look at the breakpoint info
4816 to see how many times the breakpoint was hit, then run again, ignoring one
4817 less than that number, and this will get you quickly to the last hit of
4820 * Ability to stop printing at NULL character
4822 "set print null-stop" will cause GDB to stop printing the characters of
4823 an array when the first NULL is encountered. This is useful when large
4824 arrays actually contain only short strings.
4826 * Shared library breakpoints
4828 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4829 breakpoints in shared libraries before the executable is run.
4831 * Hardware watchpoints
4833 There is a new hardware breakpoint for the watch command for sparclite
4834 targets. See gdb/sparclite/hw_breakpoint.note.
4836 Hardware watchpoints are also now supported under GNU/Linux.
4840 Annotations have been added. These are for use with graphical interfaces,
4841 and are still experimental. Currently only gdba.el uses these.
4843 * Improved Irix 5 support
4845 GDB now works properly with Irix 5.2.
4847 * Improved HPPA support
4849 GDB now works properly with the latest GCC and GAS.
4851 * New native configurations
4853 Sequent PTX4 i[34]86-sequent-ptx4
4854 HPPA running OSF/1 hppa*-*-osf*
4855 Atari TT running SVR4 m68*-*-sysv4*
4856 RS/6000 LynxOS rs6000-*-lynxos*
4860 OS/9000 i[34]86-*-os9k
4861 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4864 * Hitachi SH7000 and E7000-PC ICE support
4866 There is now support for communicating with the Hitachi E7000-PC ICE.
4867 This is available automatically when GDB is configured for the SH.
4871 As usual, a variety of small fixes and improvements, both generic
4872 and configuration-specific. See the ChangeLog for more detail.
4874 *** Changes in GDB-4.12:
4876 * Irix 5 is now supported
4880 GDB-4.12 on the HPPA has a number of changes which make it unable
4881 to debug the output from the currently released versions of GCC and
4882 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4883 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4884 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4887 *** Changes in GDB-4.11:
4889 * User visible changes:
4893 The "set remotedebug" option is now consistent between the mips remote
4894 target, remote targets using the gdb-specific protocol, UDI (AMD's
4895 debug protocol for the 29k) and the 88k bug monitor. It is now an
4896 integer specifying a debug level (normally 0 or 1, but 2 means more
4897 debugging info for the mips target).
4899 * DEC Alpha native support
4901 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4902 debug info, but GDB works fairly well with the DEC compiler and should
4903 work with a future GCC release. See the README file for a few
4904 Alpha-specific notes.
4906 * Preliminary thread implementation
4908 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4910 * LynxOS native and target support for 386
4912 This release has been hosted on LynxOS 2.2, and also can be configured
4913 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4916 * Improvements in C++ mangling/demangling.
4918 This release has much better g++ debugging, specifically in name
4919 mangling/demangling, virtual function calls, print virtual table,
4920 call methods, ...etc.
4922 *** Changes in GDB-4.10:
4924 * User visible changes:
4926 Remote debugging using the GDB-specific (`target remote') protocol now
4927 supports the `load' command. This is only useful if you have some
4928 other way of getting the stub to the target system, and you can put it
4929 somewhere in memory where it won't get clobbered by the download.
4931 Filename completion now works.
4933 When run under emacs mode, the "info line" command now causes the
4934 arrow to point to the line specified. Also, "info line" prints
4935 addresses in symbolic form (as well as hex).
4937 All vxworks based targets now support a user settable option, called
4938 vxworks-timeout. This option represents the number of seconds gdb
4939 should wait for responses to rpc's. You might want to use this if
4940 your vxworks target is, perhaps, a slow software simulator or happens
4941 to be on the far side of a thin network line.
4945 This release contains support for using a DEC alpha as a GDB host for
4946 cross debugging. Native alpha debugging is not supported yet.
4949 *** Changes in GDB-4.9:
4953 This is the first GDB release which is accompanied by a matching testsuite.
4954 The testsuite requires installation of dejagnu, which should be available
4955 via ftp from most sites that carry GNU software.
4959 'Cfront' style demangling has had its name changed to 'ARM' style, to
4960 emphasize that it was written from the specifications in the C++ Annotated
4961 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4962 disclaimers, it still generated too much confusion with users attempting to
4963 use gdb with AT&T cfront.
4967 GDB now uses a standard remote interface to a simulator library.
4968 So far, the library contains simulators for the Zilog Z8001/2, the
4969 Hitachi H8/300, H8/500 and Super-H.
4971 * New targets supported
4973 H8/300 simulator h8300-hitachi-hms or h8300hms
4974 H8/500 simulator h8500-hitachi-hms or h8500hms
4975 SH simulator sh-hitachi-hms or sh
4976 Z8000 simulator z8k-zilog-none or z8ksim
4977 IDT MIPS board over serial line mips-idt-ecoff
4979 Cross-debugging to GO32 targets is supported. It requires a custom
4980 version of the i386-stub.c module which is integrated with the
4981 GO32 memory extender.
4983 * New remote protocols
4985 MIPS remote debugging protocol.
4987 * New source languages supported
4989 This version includes preliminary support for Chill, a Pascal like language
4990 used by telecommunications companies. Chill support is also being integrated
4991 into the GNU compiler, but we don't know when it will be publically available.
4994 *** Changes in GDB-4.8:
4996 * HP Precision Architecture supported
4998 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4999 version of this support was available as a set of patches from the
5000 University of Utah. GDB does not support debugging of programs
5001 compiled with the HP compiler, because HP will not document their file
5002 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5003 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5005 Many problems in the preliminary version have been fixed.
5007 * Faster and better demangling
5009 We have improved template demangling and fixed numerous bugs in the GNU style
5010 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5011 character types (wchar_t) are now supported. Demangling of each symbol is now
5012 only done once, and is cached when the symbol table for a file is read in.
5013 This results in a small increase in memory usage for C programs, a moderate
5014 increase in memory usage for C++ programs, and a fantastic speedup in
5017 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5018 from the specifications in the Annotated Reference Manual, which AT&T's
5019 compiler does not actually implement.
5021 * G++ multiple inheritance compiler problem
5023 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5024 inheritance lattices was reworked to properly discover ambiguities. We
5025 recently found an example which causes this new algorithm to fail in a
5026 very subtle way, producing bad debug information for those classes.
5027 The file 'gcc.patch' (in this directory) can be applied to gcc to
5028 circumvent the problem. A future GCC release will contain a complete
5031 The previous G++ debug info problem (mentioned below for the gdb-4.7
5032 release) is fixed in gcc version 2.3.2.
5034 * Improved configure script
5036 The `configure' script will now attempt to guess your system type if
5037 you don't supply a host system type. The old scheme of supplying a
5038 host system triplet is preferable over using this. All the magic is
5039 done in the new `config.guess' script. Examine it for details.
5041 We have also brought our configure script much more in line with the FSF's
5042 version. It now supports the --with-xxx options. In particular,
5043 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5044 The resulting GDB will not be able to read arbitrary object file formats --
5045 only the format ``expected'' to be used on the configured target system.
5046 We hope to make this the default in a future release.
5048 * Documentation improvements
5050 There's new internal documentation on how to modify GDB, and how to
5051 produce clean changes to the code. We implore people to read it
5052 before submitting changes.
5054 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5055 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5056 `info' files are also provided. To build `info' files from scratch,
5057 you will need the latest `makeinfo' release, which will be available in
5058 a future texinfo-X.Y release.
5060 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5061 We're not sure exactly which versions have this problem, but it has
5062 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5063 or better. If that isn't possible, there is a patch in
5064 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5065 around this problem.
5069 GDB now supports array constants that can be used in expressions typed in by
5070 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5071 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5074 The new directory `gdb/sparclite' contains a program that demonstrates
5075 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5077 * New native hosts supported
5079 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5080 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5082 * New targets supported
5084 AMD 29k family via UDI a29k-amd-udi or udi29k
5086 * New file formats supported
5088 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5089 HPUX core files, and SCO 3.2v2 core files.
5093 Attaching to processes now works again; thanks for the many bug reports.
5095 We have also stomped on a bunch of core dumps caused by
5096 printf_filtered("%s") problems.
5098 We eliminated a copyright problem on the rpc and ptrace header files
5099 for VxWorks, which was discovered at the last minute during the 4.7
5100 release. You should now be able to build a VxWorks GDB.
5102 You can now interrupt gdb while an attached process is running. This
5103 will cause the attached process to stop, and give control back to GDB.
5105 We fixed problems caused by using too many file descriptors
5106 for reading symbols from object files and libraries. This was
5107 especially a problem for programs that used many (~100) shared
5110 The `step' command now only enters a subroutine if there is line number
5111 information for the subroutine. Otherwise it acts like the `next'
5112 command. Previously, `step' would enter subroutines if there was
5113 any debugging information about the routine. This avoids problems
5114 when using `cc -g1' on MIPS machines.
5116 * Internal improvements
5118 GDB's internal interfaces have been improved to make it easier to support
5119 debugging of multiple languages in the future.
5121 GDB now uses a common structure for symbol information internally.
5122 Minimal symbols (derived from linkage symbols in object files), partial
5123 symbols (from a quick scan of debug information), and full symbols
5124 contain a common subset of information, making it easier to write
5125 shared code that handles any of them.
5127 * New command line options
5129 We now accept --silent as an alias for --quiet.
5133 The memory-mapped-malloc library is now licensed under the GNU Library
5134 General Public License.
5136 *** Changes in GDB-4.7:
5138 * Host/native/target split
5140 GDB has had some major internal surgery to untangle the support for
5141 hosts and remote targets. Now, when you configure GDB for a remote
5142 target, it will no longer load in all of the support for debugging
5143 local programs on the host. When fully completed and tested, this will
5144 ensure that arbitrary host/target combinations are possible.
5146 The primary conceptual shift is to separate the non-portable code in
5147 GDB into three categories. Host specific code is required any time GDB
5148 is compiled on that host, regardless of the target. Target specific
5149 code relates to the peculiarities of the target, but can be compiled on
5150 any host. Native specific code is everything else: it can only be
5151 built when the host and target are the same system. Child process
5152 handling and core file support are two common `native' examples.
5154 GDB's use of /proc for controlling Unix child processes is now cleaner.
5155 It has been split out into a single module under the `target_ops' vector,
5156 plus two native-dependent functions for each system that uses /proc.
5158 * New hosts supported
5160 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5161 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5162 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5164 * New targets supported
5166 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5167 68030 and CPU32 m68030-*-*, m68332-*-*
5169 * New native hosts supported
5171 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5172 (386bsd is not well tested yet)
5173 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5175 * New file formats supported
5177 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5178 supports reading of `a.out.adobe' object files, which are an a.out
5179 format extended with minimal information about multiple sections.
5183 `show copying' is the same as the old `info copying'.
5184 `show warranty' is the same as `info warrantee'.
5185 These were renamed for consistency. The old commands continue to work.
5187 `info handle' is a new alias for `info signals'.
5189 You can now define pre-command hooks, which attach arbitrary command
5190 scripts to any command. The commands in the hook will be executed
5191 prior to the user's command. You can also create a hook which will be
5192 executed whenever the program stops. See gdb.texinfo.
5196 We now deal with Cfront style name mangling, and can even extract type
5197 info from mangled symbols. GDB can automatically figure out which
5198 symbol mangling style your C++ compiler uses.
5200 Calling of methods and virtual functions has been improved as well.
5204 The crash that occured when debugging Sun Ansi-C compiled binaries is
5205 fixed. This was due to mishandling of the extra N_SO stabs output
5208 We also finally got Ultrix 4.2 running in house, and fixed core file
5209 support, with help from a dozen people on the net.
5211 John M. Farrell discovered that the reason that single-stepping was so
5212 slow on all of the Mips based platforms (primarily SGI and DEC) was
5213 that we were trying to demangle and lookup a symbol used for internal
5214 purposes on every instruction that was being stepped through. Changing
5215 the name of that symbol so that it couldn't be mistaken for a C++
5216 mangled symbol sped things up a great deal.
5218 Rich Pixley sped up symbol lookups in general by getting much smarter
5219 about when C++ symbol mangling is necessary. This should make symbol
5220 completion (TAB on the command line) much faster. It's not as fast as
5221 we'd like, but it's significantly faster than gdb-4.6.
5225 A new user controllable variable 'call_scratch_address' can
5226 specify the location of a scratch area to be used when GDB
5227 calls a function in the target. This is necessary because the
5228 usual method of putting the scratch area on the stack does not work
5229 in systems that have separate instruction and data spaces.
5231 We integrated changes to support the 29k UDI (Universal Debugger
5232 Interface), but discovered at the last minute that we didn't have all
5233 of the appropriate copyright paperwork. We are working with AMD to
5234 resolve this, and hope to have it available soon.
5238 We have sped up the remote serial line protocol, especially for targets
5239 with lots of registers. It now supports a new `expedited status' ('T')
5240 message which can be used in place of the existing 'S' status message.
5241 This allows the remote stub to send only the registers that GDB
5242 needs to make a quick decision about single-stepping or conditional
5243 breakpoints, eliminating the need to fetch the entire register set for
5244 each instruction being stepped through.
5246 The GDB remote serial protocol now implements a write-through cache for
5247 registers, only re-reading the registers if the target has run.
5249 There is also a new remote serial stub for SPARC processors. You can
5250 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5251 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5252 processor with a serial port.
5256 Configure.in files have become much easier to read and modify. A new
5257 `table driven' format makes it more obvious what configurations are
5258 supported, and what files each one uses.
5262 There is a new opcodes library which will eventually contain all of the
5263 disassembly routines and opcode tables. At present, it only contains
5264 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5265 disassembler (binutils/objdump) to share these routines.
5267 The libiberty library is now copylefted under the GNU Library General
5268 Public License. This allows more liberal use, and was done so libg++
5269 can use it. This makes no difference to GDB, since the Library License
5270 grants all the rights from the General Public License.
5274 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5275 reference to the stabs symbol info used by the debugger. It is (as far
5276 as we know) the only published document on this fascinating topic. We
5277 encourage you to read it, compare it to the stabs information on your
5278 system, and send improvements on the document in general (to
5279 bug-gdb@prep.ai.mit.edu).
5281 And, of course, many bugs have been fixed.
5284 *** Changes in GDB-4.6:
5286 * Better support for C++ function names
5288 GDB now accepts as input the "demangled form" of C++ overloaded function
5289 names and member function names, and can do command completion on such names
5290 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5291 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5292 Make use of command completion, it is your friend.
5294 GDB also now accepts a variety of C++ mangled symbol formats. They are
5295 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5296 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5297 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5298 for the list of formats.
5300 * G++ symbol mangling problem
5302 Recent versions of gcc have a bug in how they emit debugging information for
5303 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5304 directory) can be applied to gcc to fix the problem. Alternatively, if you
5305 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5306 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5307 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5310 * New 'maintenance' command
5312 All of the commands related to hacking GDB internals have been moved out of
5313 the main command set, and now live behind the 'maintenance' command. This
5314 can also be abbreviated as 'mt'. The following changes were made:
5316 dump-me -> maintenance dump-me
5317 info all-breakpoints -> maintenance info breakpoints
5318 printmsyms -> maintenance print msyms
5319 printobjfiles -> maintenance print objfiles
5320 printpsyms -> maintenance print psymbols
5321 printsyms -> maintenance print symbols
5323 The following commands are new:
5325 maintenance demangle Call internal GDB demangler routine to
5326 demangle a C++ link name and prints the result.
5327 maintenance print type Print a type chain for a given symbol
5329 * Change to .gdbinit file processing
5331 We now read the $HOME/.gdbinit file before processing the argv arguments
5332 (e.g. reading symbol files or core files). This allows global parameters to
5333 be set, which will apply during the symbol reading. The ./.gdbinit is still
5334 read after argv processing.
5336 * New hosts supported
5338 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5340 GNU/Linux support i386-unknown-linux or linux
5342 We are also including code to support the HP/PA running BSD and HPUX. This
5343 is almost guaranteed not to work, as we didn't have time to test or build it
5344 for this release. We are including it so that the more adventurous (or
5345 masochistic) of you can play with it. We also had major problems with the
5346 fact that the compiler that we got from HP doesn't support the -g option.
5349 * New targets supported
5351 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5353 * More smarts about finding #include files
5355 GDB now remembers the compilation directory for all include files, and for
5356 all files from which C is generated (like yacc and lex sources). This
5357 greatly improves GDB's ability to find yacc/lex sources, and include files,
5358 especially if you are debugging your program from a directory different from
5359 the one that contains your sources.
5361 We also fixed a bug which caused difficulty with listing and setting
5362 breakpoints in include files which contain C code. (In the past, you had to
5363 try twice in order to list an include file that you hadn't looked at before.)
5365 * Interesting infernals change
5367 GDB now deals with arbitrary numbers of sections, where the symbols for each
5368 section must be relocated relative to that section's landing place in the
5369 target's address space. This work was needed to support ELF with embedded
5370 stabs used by Solaris-2.0.
5372 * Bug fixes (of course!)
5374 There have been loads of fixes for the following things:
5375 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5376 i960, stabs, DOS(GO32), procfs, etc...
5378 See the ChangeLog for details.
5380 *** Changes in GDB-4.5:
5382 * New machines supported (host and target)
5384 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5386 SGI Irix-4.x mips-sgi-irix4 or iris4
5388 * New malloc package
5390 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5391 Mmalloc is capable of handling mutiple heaps of memory. It is also
5392 capable of saving a heap to a file, and then mapping it back in later.
5393 This can be used to greatly speedup the startup of GDB by using a
5394 pre-parsed symbol table which lives in a mmalloc managed heap. For
5395 more details, please read mmalloc/mmalloc.texi.
5399 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5400 'help info proc' for details.
5402 * MIPS ecoff symbol table format
5404 The code that reads MIPS symbol table format is now supported on all hosts.
5405 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5408 * File name changes for MS-DOS
5410 Many files in the config directories have been renamed to make it easier to
5411 support GDB on MS-DOSe systems (which have very restrictive file name
5412 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5413 environment) is close to working but has some remaining problems. Note
5414 that debugging of DOS programs is not supported, due to limitations
5415 in the ``operating system'', but it can be used to host cross-debugging.
5417 * Cross byte order fixes
5419 Many fixes have been made to support cross debugging of Sparc and MIPS
5420 targets from hosts whose byte order differs.
5422 * New -mapped and -readnow options
5424 If memory-mapped files are available on your system through the 'mmap'
5425 system call, you can use the -mapped option on the `file' or
5426 `symbol-file' commands to cause GDB to write the symbols from your
5427 program into a reusable file. If the program you are debugging is
5428 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5429 Future GDB debugging sessions will notice the presence of this file,
5430 and will quickly map in symbol information from it, rather than reading
5431 the symbol table from the executable program. Using the '-mapped'
5432 option in a GDB `file' or `symbol-file' command has the same effect as
5433 starting GDB with the '-mapped' command-line option.
5435 You can cause GDB to read the entire symbol table immediately by using
5436 the '-readnow' option with any of the commands that load symbol table
5437 information (or on the GDB command line). This makes the command
5438 slower, but makes future operations faster.
5440 The -mapped and -readnow options are typically combined in order to
5441 build a `fred.syms' file that contains complete symbol information.
5442 A simple GDB invocation to do nothing but build a `.syms' file for future
5445 gdb -batch -nx -mapped -readnow programname
5447 The `.syms' file is specific to the host machine on which GDB is run.
5448 It holds an exact image of GDB's internal symbol table. It cannot be
5449 shared across multiple host platforms.
5451 * longjmp() handling
5453 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5454 siglongjmp() without losing control. This feature has not yet been ported to
5455 all systems. It currently works on many 386 platforms, all MIPS-based
5456 platforms (SGI, DECstation, etc), and Sun3/4.
5460 Preliminary work has been put in to support the new Solaris OS from Sun. At
5461 this time, it can control and debug processes, but it is not capable of
5466 As always, many many bug fixes. The major areas were with g++, and mipsread.
5467 People using the MIPS-based platforms should experience fewer mysterious
5468 crashes and trashed symbol tables.
5470 *** Changes in GDB-4.4:
5472 * New machines supported (host and target)
5474 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5476 BSD Reno on Vax vax-dec-bsd
5477 Ultrix on Vax vax-dec-ultrix
5479 * New machines supported (target)
5481 AMD 29000 embedded, using EBMON a29k-none-none
5485 GDB continues to improve its handling of C++. `References' work better.
5486 The demangler has also been improved, and now deals with symbols mangled as
5487 per the Annotated C++ Reference Guide.
5489 GDB also now handles `stabs' symbol information embedded in MIPS
5490 `ecoff' symbol tables. Since the ecoff format was not easily
5491 extensible to handle new languages such as C++, this appeared to be a
5492 good way to put C++ debugging info into MIPS binaries. This option
5493 will be supported in the GNU C compiler, version 2, when it is
5496 * New features for SVR4
5498 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5499 shared libraries. Debugging dynamically linked programs should present
5500 only minor differences from debugging statically linked programs.
5502 The `info proc' command will print out information about any process
5503 on an SVR4 system (including the one you are debugging). At the moment,
5504 it prints the address mappings of the process.
5506 If you bring up GDB on another SVR4 system, please send mail to
5507 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5509 * Better dynamic linking support in SunOS
5511 Reading symbols from shared libraries which contain debugging symbols
5512 now works properly. However, there remain issues such as automatic
5513 skipping of `transfer vector' code during function calls, which
5514 make it harder to debug code in a shared library, than to debug the
5515 same code linked statically.
5519 GDB is now using the latest `getopt' routines from the FSF. This
5520 version accepts the -- prefix for options with long names. GDB will
5521 continue to accept the old forms (-option and +option) as well.
5522 Various single letter abbreviations for options have been explicity
5523 added to the option table so that they won't get overshadowed in the
5524 future by other options that begin with the same letter.
5528 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5529 Many assorted bugs have been handled. Many more remain to be handled.
5530 See the various ChangeLog files (primarily in gdb and bfd) for details.
5533 *** Changes in GDB-4.3:
5535 * New machines supported (host and target)
5537 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5538 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5539 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5541 * Almost SCO Unix support
5543 We had hoped to support:
5544 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5545 (except for core file support), but we discovered very late in the release
5546 that it has problems with process groups that render gdb unusable. Sorry
5547 about that. I encourage people to fix it and post the fixes.
5549 * Preliminary ELF and DWARF support
5551 GDB can read ELF object files on System V Release 4, and can handle
5552 debugging records for C, in DWARF format, in ELF files. This support
5553 is preliminary. If you bring up GDB on another SVR4 system, please
5554 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5559 GDB now uses the latest `readline' library. One user-visible change
5560 is that two tabs will list possible command completions, which previously
5561 required typing M-? (meta-question mark, or ESC ?).
5565 The `stepi' bug that many of you noticed has been squashed.
5566 Many bugs in C++ have been handled. Many more remain to be handled.
5567 See the various ChangeLog files (primarily in gdb and bfd) for details.
5569 * State of the MIPS world (in case you wondered):
5571 GDB can understand the symbol tables emitted by the compilers
5572 supplied by most vendors of MIPS-based machines, including DEC. These
5573 symbol tables are in a format that essentially nobody else uses.
5575 Some versions of gcc come with an assembler post-processor called
5576 mips-tfile. This program is required if you want to do source-level
5577 debugging of gcc-compiled programs. I believe FSF does not ship
5578 mips-tfile with gcc version 1, but it will eventually come with gcc
5581 Debugging of g++ output remains a problem. g++ version 1.xx does not
5582 really support it at all. (If you're lucky, you should be able to get
5583 line numbers and stack traces to work, but no parameters or local
5584 variables.) With some work it should be possible to improve the
5587 When gcc version 2 is released, you will have somewhat better luck.
5588 However, even then you will get confusing results for inheritance and
5591 We will eventually provide full debugging of g++ output on
5592 DECstations. This will probably involve some kind of stabs-in-ecoff
5593 encapulation, but the details have not been worked out yet.
5596 *** Changes in GDB-4.2:
5598 * Improved configuration
5600 Only one copy of `configure' exists now, and it is not self-modifying.
5601 Porting BFD is simpler.
5605 The `step' and `next' commands now only stop at the first instruction
5606 of a source line. This prevents the multiple stops that used to occur
5607 in switch statements, for-loops, etc. `Step' continues to stop if a
5608 function that has debugging information is called within the line.
5612 Lots of small bugs fixed. More remain.
5614 * New host supported (not target)
5616 Intel 386 PC clone running Mach i386-none-mach
5619 *** Changes in GDB-4.1:
5621 * Multiple source language support
5623 GDB now has internal scaffolding to handle several source languages.
5624 It determines the type of each source file from its filename extension,
5625 and will switch expression parsing and number formatting to match the
5626 language of the function in the currently selected stack frame.
5627 You can also specifically set the language to be used, with
5628 `set language c' or `set language modula-2'.
5632 GDB now has preliminary support for the GNU Modula-2 compiler,
5633 currently under development at the State University of New York at
5634 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5635 continue through the fall of 1991 and into 1992.
5637 Other Modula-2 compilers are currently not supported, and attempting to
5638 debug programs compiled with them will likely result in an error as the
5639 symbol table is read. Feel free to work on it, though!
5641 There are hooks in GDB for strict type checking and range checking,
5642 in the `Modula-2 philosophy', but they do not currently work.
5646 GDB can now write to executable and core files (e.g. patch
5647 a variable's value). You must turn this switch on, specify
5648 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5649 by assigning a new value to a variable. Modifications take
5652 * Automatic SunOS shared library reading
5654 When you run your program, GDB automatically determines where its
5655 shared libraries (if any) have been loaded, and reads their symbols.
5656 The `share' command is no longer needed. This also works when
5657 examining core files.
5661 You can specify the number of lines that the `list' command shows.
5664 * New machines supported (host and target)
5666 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5667 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5668 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5670 * New hosts supported (not targets)
5672 IBM RT/PC: romp-ibm-aix or rtpc
5674 * New targets supported (not hosts)
5676 AMD 29000 embedded with COFF a29k-none-coff
5677 AMD 29000 embedded with a.out a29k-none-aout
5678 Ultracomputer remote kernel debug a29k-nyu-kern
5680 * New remote interfaces
5686 *** Changes in GDB-4.0:
5690 Wide output is wrapped at good places to make the output more readable.
5692 Gdb now supports cross-debugging from a host machine of one type to a
5693 target machine of another type. Communication with the target system
5694 is over serial lines. The ``target'' command handles connecting to the
5695 remote system; the ``load'' command will download a program into the
5696 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5697 also supports debugging of realtime processes running under VxWorks,
5698 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5699 stub on the target system.
5701 New CPUs supported include the AMD 29000 and Intel 960.
5703 GDB now reads object files and symbol tables via a ``binary file''
5704 library, which allows a single copy of GDB to debug programs of multiple
5705 object file types such as a.out and coff.
5707 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5708 refcard.dvi and refcard.ps are available to format it).
5711 * Control-Variable user interface simplified
5713 All variables that control the operation of the debugger can be set
5714 by the ``set'' command, and displayed by the ``show'' command.
5716 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5717 ``Show prompt'' produces the response:
5718 Gdb's prompt is new-gdb=>.
5720 What follows are the NEW set commands. The command ``help set'' will
5721 print a complete list of old and new set commands. ``help set FOO''
5722 will give a longer description of the variable FOO. ``show'' will show
5723 all of the variable descriptions and their current settings.
5725 confirm on/off: Enables warning questions for operations that are
5726 hard to recover from, e.g. rerunning the program while
5727 it is already running. Default is ON.
5729 editing on/off: Enables EMACS style command line editing
5730 of input. Previous lines can be recalled with
5731 control-P, the current line can be edited with control-B,
5732 you can search for commands with control-R, etc.
5735 history filename NAME: NAME is where the gdb command history
5736 will be stored. The default is .gdb_history,
5737 or the value of the environment variable
5740 history size N: The size, in commands, of the command history. The
5741 default is 256, or the value of the environment variable
5744 history save on/off: If this value is set to ON, the history file will
5745 be saved after exiting gdb. If set to OFF, the
5746 file will not be saved. The default is OFF.
5748 history expansion on/off: If this value is set to ON, then csh-like
5749 history expansion will be performed on
5750 command line input. The default is OFF.
5752 radix N: Sets the default radix for input and output. It can be set
5753 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5754 in the current radix, so "set radix 10" is always a no-op.
5756 height N: This integer value is the number of lines on a page. Default
5757 is 24, the current `stty rows'' setting, or the ``li#''
5758 setting from the termcap entry matching the environment
5761 width N: This integer value is the number of characters on a line.
5762 Default is 80, the current `stty cols'' setting, or the ``co#''
5763 setting from the termcap entry matching the environment
5766 Note: ``set screensize'' is obsolete. Use ``set height'' and
5767 ``set width'' instead.
5769 print address on/off: Print memory addresses in various command displays,
5770 such as stack traces and structure values. Gdb looks
5771 more ``symbolic'' if you turn this off; it looks more
5772 ``machine level'' with it on. Default is ON.
5774 print array on/off: Prettyprint arrays. New convenient format! Default
5777 print demangle on/off: Print C++ symbols in "source" form if on,
5780 print asm-demangle on/off: Same, for assembler level printouts
5783 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5786 * Support for Epoch Environment.
5788 The epoch environment is a version of Emacs v18 with windowing. One
5789 new command, ``inspect'', is identical to ``print'', except that if you
5790 are running in the epoch environment, the value is printed in its own
5794 * Support for Shared Libraries
5796 GDB can now debug programs and core files that use SunOS shared libraries.
5797 Symbols from a shared library cannot be referenced
5798 before the shared library has been linked with the program (this
5799 happens after you type ``run'' and before the function main() is entered).
5800 At any time after this linking (including when examining core files
5801 from dynamically linked programs), gdb reads the symbols from each
5802 shared library when you type the ``sharedlibrary'' command.
5803 It can be abbreviated ``share''.
5805 sharedlibrary REGEXP: Load shared object library symbols for files
5806 matching a unix regular expression. No argument
5807 indicates to load symbols for all shared libraries.
5809 info sharedlibrary: Status of loaded shared libraries.
5814 A watchpoint stops execution of a program whenever the value of an
5815 expression changes. Checking for this slows down execution
5816 tremendously whenever you are in the scope of the expression, but is
5817 quite useful for catching tough ``bit-spreader'' or pointer misuse
5818 problems. Some machines such as the 386 have hardware for doing this
5819 more quickly, and future versions of gdb will use this hardware.
5821 watch EXP: Set a watchpoint (breakpoint) for an expression.
5823 info watchpoints: Information about your watchpoints.
5825 delete N: Deletes watchpoint number N (same as breakpoints).
5826 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5827 enable N: Re-enables watchpoint number N (same as breakpoints).
5830 * C++ multiple inheritance
5832 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5835 * C++ exception handling
5837 Gdb now supports limited C++ exception handling. Besides the existing
5838 ability to breakpoint on an exception handler, gdb can breakpoint on
5839 the raising of an exception (before the stack is peeled back to the
5842 catch FOO: If there is a FOO exception handler in the dynamic scope,
5843 set a breakpoint to catch exceptions which may be raised there.
5844 Multiple exceptions (``catch foo bar baz'') may be caught.
5846 info catch: Lists all exceptions which may be caught in the
5847 current stack frame.
5850 * Minor command changes
5852 The command ``call func (arg, arg, ...)'' now acts like the print
5853 command, except it does not print or save a value if the function's result
5854 is void. This is similar to dbx usage.
5856 The ``up'' and ``down'' commands now always print the frame they end up
5857 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5858 frames without printing.
5860 * New directory command
5862 'dir' now adds directories to the FRONT of the source search path.
5863 The path starts off empty. Source files that contain debug information
5864 about the directory in which they were compiled can be found even
5865 with an empty path; Sun CC and GCC include this information. If GDB can't
5866 find your source file in the current directory, type "dir .".
5868 * Configuring GDB for compilation
5870 For normal use, type ``./configure host''. See README or gdb.texinfo
5873 GDB now handles cross debugging. If you are remotely debugging between
5874 two different machines, type ``./configure host -target=targ''.
5875 Host is the machine where GDB will run; targ is the machine
5876 where the program that you are debugging will run.