1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.8
6 * GDB now supports hardware watchpoints on x86 GNU Hurd.
10 ** You can now access frame registers from Python scripts.
11 ** New attribute 'producer' for gdb.Symtab objects.
12 ** gdb.Objfile objects have a new attribute "progspace",
13 which is the gdb.Progspace object of the containing program space.
14 ** gdb.Objfile objects have a new attribute "owner".
15 ** gdb.Objfile objects have a new attribute "build_id",
16 which is the build ID generated when the file was built.
17 ** gdb.Objfile objects have a new method "add_separate_debug_file".
18 ** A new event "gdb.clear_objfiles" has been added, triggered when
19 selecting a new file to debug.
20 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
21 ** New function gdb.lookup_objfile.
23 New events which are triggered when GDB modifies the state of the
26 ** gdb.events.inferior_call_pre: Function call is about to be made.
27 ** gdb.events.inferior_call_post: Function call has just been made.
28 ** gdb.events.memory_changed: A memory location has been altered.
29 ** gdb.events.register_changed: A register has been altered.
31 * New Python-based convenience functions:
33 ** $_caller_is(name [, number_of_frames])
34 ** $_caller_matches(regexp [, number_of_frames])
35 ** $_any_caller_is(name [, number_of_frames])
36 ** $_any_caller_matches(regexp [, number_of_frames])
38 * GDB now supports the compilation and injection of source code into
39 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
40 to compile the source code to object code, and if successful, inject
41 and execute that code within the current context of the inferior.
42 Currently the C language is supported. The commands used to
43 interface with this new feature are:
45 compile code [-raw|-r] [--] [source code]
46 compile file [-raw|-r] filename
50 queue-signal signal-name-or-number
51 Queue a signal to be delivered to the thread when it is resumed.
53 add-auto-load-scripts-directory directory
54 Add entries to the list of directories from which to load auto-loaded
57 maint print user-registers
58 List all currently available "user" registers.
60 compile code [-r|-raw] [--] [source code]
61 Compile, inject, and execute in the inferior the executable object
62 code produced by compiling the provided source code.
64 compile file [-r|-raw] filename
65 Compile and inject into the inferior the executable object code
66 produced by compiling the source code stored in the filename
69 * On resume, GDB now always passes the signal the program had stopped
70 for to the thread the signal was sent to, even if the user changed
71 threads before resuming. Previously GDB would often (but not
72 always) deliver the signal to the thread that happens to be current
75 * Conversely, the "signal" command now consistently delivers the
76 requested signal to the current thread. GDB now asks for
77 confirmation if the program had stopped for a signal and the user
78 switched threads meanwhile.
80 * "breakpoint always-inserted" modes "off" and "auto" merged.
82 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
83 won't remove breakpoints from the target until all threads stop,
84 even in non-stop mode. The "auto" mode has been removed, and "off"
85 is now the default mode.
89 set debug symbol-lookup
90 show debug symbol-lookup
91 Control display of debugging info regarding symbol lookup.
95 ** The -list-thread-groups command outputs an exit-code field for
96 inferiors that have exited.
100 Support for these obsolete configurations has been removed.
102 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
103 SGI Irix-5.x mips-*-irix5*
104 SGI Irix-6.x mips-*-irix6*
105 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
106 VAX running Ultrix vax-*-ultrix*
108 *** Changes in GDB 7.8
110 * New command line options
113 This is an alias for the --data-directory option.
115 * GDB supports printing and modifying of variable length automatic arrays
116 as specified in ISO C99.
118 * The ARM simulator now supports instruction level tracing
119 with or without disassembly.
123 GDB now has support for scripting using Guile. Whether this is
124 available is determined at configure time.
125 Guile version 2.0 or greater is required.
126 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
128 * New commands (for set/show, see "New options" below)
132 Invoke CODE by passing it to the Guile interpreter.
136 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
138 info auto-load guile-scripts [regexp]
139 Print the list of automatically loaded Guile scripts.
141 * The source command is now capable of sourcing Guile scripts.
142 This feature is dependent on the debugger being built with Guile support.
146 set print symbol-loading (off|brief|full)
147 show print symbol-loading
148 Control whether to print informational messages when loading symbol
149 information for a file. The default is "full", but when debugging
150 programs with large numbers of shared libraries the amount of output
153 set guile print-stack (none|message|full)
154 show guile print-stack
155 Show a stack trace when an error is encountered in a Guile script.
157 set auto-load guile-scripts (on|off)
158 show auto-load guile-scripts
159 Control auto-loading of Guile script files.
161 maint ada set ignore-descriptive-types (on|off)
162 maint ada show ignore-descriptive-types
163 Control whether the debugger should ignore descriptive types in Ada
164 programs. The default is not to ignore the descriptive types. See
165 the user manual for more details on descriptive types and the intended
166 usage of this option.
168 set auto-connect-native-target
170 Control whether GDB is allowed to automatically connect to the
171 native target for the run, attach, etc. commands when not connected
172 to any target yet. See also "target native" below.
174 set record btrace replay-memory-access (read-only|read-write)
175 show record btrace replay-memory-access
176 Control what memory accesses are allowed during replay.
178 maint set target-async (on|off)
179 maint show target-async
180 This controls whether GDB targets operate in synchronous or
181 asynchronous mode. Normally the default is asynchronous, if it is
182 available; but this can be changed to more easily debug problems
183 occurring only in synchronous mode.
185 set mi-async (on|off)
187 Control whether MI asynchronous mode is preferred. This supersedes
188 "set target-async" of previous GDB versions.
190 * "set target-async" is deprecated as a CLI option and is now an alias
191 for "set mi-async" (only puts MI into async mode).
193 * Background execution commands (e.g., "c&", "s&", etc.) are now
194 possible ``out of the box'' if the target supports them. Previously
195 the user would need to explicitly enable the possibility with the
196 "set target-async on" command.
198 * New features in the GDB remote stub, GDBserver
200 ** New option --debug-format=option1[,option2,...] allows one to add
201 additional text to each output. At present only timestamps
202 are supported: --debug-format=timestamps.
203 Timestamps can also be turned on with the
204 "monitor set debug-format timestamps" command from GDB.
206 * The 'record instruction-history' command now starts counting instructions
207 at one. This also affects the instruction ranges reported by the
208 'record function-call-history' command when given the /i modifier.
210 * The command 'record function-call-history' supports a new modifier '/c' to
211 indent the function names based on their call stack depth.
212 The fields for the '/i' and '/l' modifier have been reordered.
213 The source line range is now prefixed with 'at'.
214 The instruction range is now prefixed with 'inst'.
215 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
216 "record instruction-history" and "list" commands.
218 * The ranges given as arguments to the 'record function-call-history' and
219 'record instruction-history' commands are now inclusive.
221 * The btrace record target now supports the 'record goto' command.
222 For locations inside the execution trace, the back trace is computed
223 based on the information stored in the execution trace.
225 * The btrace record target supports limited reverse execution and replay.
226 The target does not record data and therefore does not allow reading
229 * The "catch syscall" command now works on s390*-linux* targets.
231 * The "compare-sections" command is no longer specific to target
232 remote. It now works with all targets.
234 * All native targets are now consistently called "native".
235 Consequently, the "target child", "target GNU", "target djgpp",
236 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
237 commands have been replaced with "target native". The QNX/NTO port
238 leaves the "procfs" target in place and adds a "native" target for
239 consistency with other ports. The impact on users should be minimal
240 as these commands previously either throwed an error, or were
241 no-ops. The target's name is visible in the output of the following
242 commands: "help target", "info target", "info files", "maint print
245 * The "target native" command now connects to the native target. This
246 can be used to launch native programs even when "set
247 auto-connect-native-target" is set to off.
249 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.
251 * Support for Intel(R) AVX-512 registers on GNU/Linux.
252 Support displaying and modifying Intel(R) AVX-512 registers
253 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
257 qXfer:btrace:read's annex
258 The qXfer:btrace:read packet supports a new annex 'delta' to read
259 branch trace incrementally.
263 ** Valid Python operations on gdb.Value objects representing
264 structs/classes invoke the corresponding overloaded operators if
266 ** New `Xmethods' feature in the Python API. Xmethods are
267 additional methods or replacements for existing methods of a C++
268 class. This feature is useful for those cases where a method
269 defined in C++ source code could be inlined or optimized out by
270 the compiler, making it unavailable to GDB.
273 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
275 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
276 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
277 its alias "share", instead.
279 * The commands "set remotebaud" and "show remotebaud" are no longer
280 supported. Use "set serial baud" and "show serial baud" (respectively)
285 ** A new option "-gdb-set mi-async" replaces "-gdb-set
286 target-async". The latter is left as a deprecated alias of the
287 former for backward compatibility. If the target supports it,
288 CLI background execution commands are now always possible by
289 default, independently of whether the frontend stated a
290 preference for asynchronous execution with "-gdb-set mi-async".
291 Previously "-gdb-set target-async off" affected both MI execution
292 commands and CLI execution commands.
294 *** Changes in GDB 7.7
296 * Improved support for process record-replay and reverse debugging on
297 arm*-linux* targets. Support for thumb32 and syscall instruction
298 recording has been added.
300 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
302 * GDB now supports Fission DWP file format version 2.
303 http://gcc.gnu.org/wiki/DebugFission
305 * New convenience function "$_isvoid", to check whether an expression
306 is void. A void expression is an expression where the type of the
307 result is "void". For example, some convenience variables may be
308 "void" when evaluated (e.g., "$_exitcode" before the execution of
309 the program being debugged; or an undefined convenience variable).
310 Another example, when calling a function whose return type is
313 * The "maintenance print objfiles" command now takes an optional regexp.
315 * The "catch syscall" command now works on arm*-linux* targets.
317 * GDB now consistently shows "<not saved>" when printing values of
318 registers the debug info indicates have not been saved in the frame
319 and there's nowhere to retrieve them from
320 (callee-saved/call-clobbered registers):
325 (gdb) info registers rax
328 Before, the former would print "<optimized out>", and the latter
329 "*value not available*".
331 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
336 ** Frame filters and frame decorators have been added.
337 ** Temporary breakpoints are now supported.
338 ** Line tables representation has been added.
339 ** New attribute 'parent_type' for gdb.Field objects.
340 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
341 ** New attribute 'name' for gdb.Type objects.
345 Nios II ELF nios2*-*-elf
346 Nios II GNU/Linux nios2*-*-linux
347 Texas Instruments MSP430 msp430*-*-elf
349 * Removed native configurations
351 Support for these a.out NetBSD and OpenBSD obsolete configurations has
352 been removed. ELF variants of these configurations are kept supported.
354 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
355 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
356 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
357 i[34567]86-*-openbsd3.[0-3]
358 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
359 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
360 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
364 Like "catch throw", but catches a re-thrown exception.
366 Renamed from old "maint check-symtabs".
368 Perform consistency checks on symtabs.
370 Expand symtabs matching an optional regexp.
373 Display the details of GDB configure-time options.
375 maint set|show per-command
376 maint set|show per-command space
377 maint set|show per-command time
378 maint set|show per-command symtab
379 Enable display of per-command gdb resource usage.
381 remove-symbol-file FILENAME
382 remove-symbol-file -a ADDRESS
383 Remove a symbol file added via add-symbol-file. The file to remove
384 can be identified by its filename or by an address that lies within
385 the boundaries of this symbol file in memory.
388 info exceptions REGEXP
389 Display the list of Ada exceptions defined in the program being
390 debugged. If provided, only the exceptions whose names match REGEXP
395 set debug symfile off|on
397 Control display of debugging info regarding reading symbol files and
398 symbol tables within those files
400 set print raw frame-arguments
401 show print raw frame-arguments
402 Set/show whether to print frame arguments in raw mode,
403 disregarding any defined pretty-printers.
405 set remote trace-status-packet
406 show remote trace-status-packet
407 Set/show the use of remote protocol qTStatus packet.
411 Control display of debugging messages related to Nios II targets.
415 Control whether target-assisted range stepping is enabled.
417 set startup-with-shell
418 show startup-with-shell
419 Specifies whether Unix child processes are started via a shell or
424 Use the target memory cache for accesses to the code segment. This
425 improves performance of remote debugging (particularly disassembly).
427 * You can now use a literal value 'unlimited' for options that
428 interpret 0 or -1 as meaning "unlimited". E.g., "set
429 trace-buffer-size unlimited" is now an alias for "set
430 trace-buffer-size -1" and "set height unlimited" is now an alias for
433 * The "set debug symtab-create" debugging option of GDB has been changed to
434 accept a verbosity level. 0 means "off", 1 provides basic debugging
435 output, and values of 2 or greater provides more verbose output.
437 * New command-line options
439 Display the details of GDB configure-time options.
441 * The command 'tsave' can now support new option '-ctf' to save trace
442 buffer in Common Trace Format.
444 * Newly installed $prefix/bin/gcore acts as a shell interface for the
447 * GDB now implements the the C++ 'typeid' operator.
449 * The new convenience variable $_exception holds the exception being
450 thrown or caught at an exception-related catchpoint.
452 * The exception-related catchpoints, like "catch throw", now accept a
453 regular expression which can be used to filter exceptions by type.
455 * The new convenience variable $_exitsignal is automatically set to
456 the terminating signal number when the program being debugged dies
457 due to an uncaught signal.
461 ** All MI commands now accept an optional "--language" option.
462 Support for this feature can be verified by using the "-list-features"
463 command, which should contain "language-option".
465 ** The new command -info-gdb-mi-command allows the user to determine
466 whether a GDB/MI command is supported or not.
468 ** The "^error" result record returned when trying to execute an undefined
469 GDB/MI command now provides a variable named "code" whose content is the
470 "undefined-command" error code. Support for this feature can be verified
471 by using the "-list-features" command, which should contain
472 "undefined-command-error-code".
474 ** The -trace-save MI command can optionally save trace buffer in Common
477 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
479 ** The command -data-list-register-values now accepts an optional
480 "--skip-unavailable" option. When used, only the available registers
483 ** The new command -trace-frame-collected dumps collected variables,
484 computed expressions, tvars, memory and registers in a traceframe.
486 ** The commands -stack-list-locals, -stack-list-arguments and
487 -stack-list-variables now accept an option "--skip-unavailable".
488 When used, only the available locals or arguments are displayed.
490 ** The -exec-run command now accepts an optional "--start" option.
491 When used, the command follows the same semantics as the "start"
492 command, stopping the program's execution at the start of its
493 main subprogram. Support for this feature can be verified using
494 the "-list-features" command, which should contain
495 "exec-run-start-option".
497 ** The new commands -catch-assert and -catch-exceptions insert
498 catchpoints stopping the program when Ada exceptions are raised.
500 ** The new command -info-ada-exceptions provides the equivalent of
501 the new "info exceptions" command.
503 * New system-wide configuration scripts
504 A GDB installation now provides scripts suitable for use as system-wide
505 configuration scripts for the following systems:
509 * GDB now supports target-assigned range stepping with remote targets.
510 This improves the performance of stepping source lines by reducing
511 the number of control packets from/to GDB. See "New remote packets"
514 * GDB now understands the element 'tvar' in the XML traceframe info.
515 It has the id of the collected trace state variables.
517 * On S/390 targets that provide the transactional-execution feature,
518 the program interruption transaction diagnostic block (TDB) is now
519 represented as a number of additional "registers" in GDB.
525 The vCont packet supports a new 'r' action, that tells the remote
526 stub to step through an address range itself, without GDB
527 involvemement at each single-step.
529 qXfer:libraries-svr4:read's annex
530 The previously unused annex of the qXfer:libraries-svr4:read packet
531 is now used to support passing an argument list. The remote stub
532 reports support for this argument list to GDB's qSupported query.
533 The defined arguments are "start" and "prev", used to reduce work
534 necessary for library list updating, resulting in significant
537 * New features in the GDB remote stub, GDBserver
539 ** GDBserver now supports target-assisted range stepping. Currently
540 enabled on x86/x86_64 GNU/Linux targets.
542 ** GDBserver now adds element 'tvar' in the XML in the reply to
543 'qXfer:traceframe-info:read'. It has the id of the collected
544 trace state variables.
546 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
549 * New 'z' formatter for printing and examining memory, this displays the
550 value as hexadecimal zero padded on the left to the size of the type.
552 * GDB can now use Windows x64 unwinding data.
554 * The "set remotebaud" command has been replaced by "set serial baud".
555 Similarly, "show remotebaud" has been replaced by "show serial baud".
556 The "set remotebaud" and "show remotebaud" commands are still available
557 to provide backward compatibility with older versions of GDB.
559 *** Changes in GDB 7.6
561 * Target record has been renamed to record-full.
562 Record/replay is now enabled with the "record full" command.
563 This also affects settings that are associated with full record/replay
564 that have been moved from "set/show record" to "set/show record full":
566 set|show record full insn-number-max
567 set|show record full stop-at-limit
568 set|show record full memory-query
570 * A new record target "record-btrace" has been added. The new target
571 uses hardware support to record the control-flow of a process. It
572 does not support replaying the execution, but it implements the
573 below new commands for investigating the recorded execution log.
574 This new recording method can be enabled using:
578 The "record-btrace" target is only available on Intel Atom processors
579 and requires a Linux kernel 2.6.32 or later.
581 * Two new commands have been added for record/replay to give information
582 about the recorded execution without having to replay the execution.
583 The commands are only supported by "record btrace".
585 record instruction-history prints the execution history at
586 instruction granularity
588 record function-call-history prints the execution history at
591 * New native configurations
593 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
594 FreeBSD/powerpc powerpc*-*-freebsd
595 x86_64/Cygwin x86_64-*-cygwin*
596 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
600 ARM AArch64 aarch64*-*-elf
601 ARM AArch64 GNU/Linux aarch64*-*-linux
602 Lynx 178 PowerPC powerpc-*-lynx*178
603 x86_64/Cygwin x86_64-*-cygwin*
604 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
606 * If the configured location of system.gdbinit file (as given by the
607 --with-system-gdbinit option at configure time) is in the
608 data-directory (as specified by --with-gdb-datadir at configure
609 time) or in one of its subdirectories, then GDB will look for the
610 system-wide init file in the directory specified by the
611 --data-directory command-line option.
613 * New command line options:
615 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
616 other initialization files, unlike -nx which disables all of them.
618 * Removed command line options
620 -epoch This was used by the gdb mode in Epoch, an ancient fork of
623 * The 'ptype' and 'whatis' commands now accept an argument to control
626 * 'info proc' now works on some core files.
630 ** Vectors can be created with gdb.Type.vector.
632 ** Python's atexit.register now works in GDB.
634 ** Types can be pretty-printed via a Python API.
636 ** Python 3 is now supported (in addition to Python 2.4 or later)
638 ** New class gdb.Architecture exposes GDB's internal representation
639 of architecture in the Python API.
641 ** New method Frame.architecture returns the gdb.Architecture object
642 corresponding to the frame's architecture.
644 * New Python-based convenience functions:
646 ** $_memeq(buf1, buf2, length)
647 ** $_streq(str1, str2)
649 ** $_regex(str, regex)
651 * The 'cd' command now defaults to using '~' (the home directory) if not
654 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
655 default for GCC since November 2000.
657 * The command 'forward-search' can now be abbreviated as 'fo'.
659 * The command 'info tracepoints' can now display 'installed on target'
660 or 'not installed on target' for each non-pending location of tracepoint.
662 * New configure options
664 --enable-libmcheck/--disable-libmcheck
665 By default, development versions are built with -lmcheck on hosts
666 that support it, in order to help track memory corruption issues.
667 Release versions, on the other hand, are built without -lmcheck
668 by default. The --enable-libmcheck/--disable-libmcheck configure
669 options allow the user to override that default.
670 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
671 This configure option allows the user to build GDB with
672 libbabeltrace using which GDB can read Common Trace Format data.
674 * New commands (for set/show, see "New options" below)
677 Catch signals. This is similar to "handle", but allows commands and
678 conditions to be attached.
681 List the BFDs known to GDB.
683 python-interactive [command]
685 Start a Python interactive prompt, or evaluate the optional command
686 and print the result of expressions.
689 "py" is a new alias for "python".
691 enable type-printer [name]...
692 disable type-printer [name]...
693 Enable or disable type printers.
697 ** For the Renesas Super-H architecture, the "regs" command has been removed
698 (has been deprecated in GDB 7.5), and "info all-registers" should be used
703 set print type methods (on|off)
704 show print type methods
705 Control whether method declarations are displayed by "ptype".
706 The default is to show them.
708 set print type typedefs (on|off)
709 show print type typedefs
710 Control whether typedef definitions are displayed by "ptype".
711 The default is to show them.
713 set filename-display basename|relative|absolute
714 show filename-display
715 Control the way in which filenames is displayed.
716 The default is "relative", which preserves previous behavior.
718 set trace-buffer-size
719 show trace-buffer-size
720 Request target to change the size of trace buffer.
722 set remote trace-buffer-size-packet auto|on|off
723 show remote trace-buffer-size-packet
724 Control the use of the remote protocol `QTBuffer:size' packet.
728 Control display of debugging messages related to ARM AArch64.
731 set debug coff-pe-read
732 show debug coff-pe-read
733 Control display of debugging messages related to reading of COFF/PE
738 Control display of debugging messages related to Mach-O symbols
741 set debug notification
742 show debug notification
743 Control display of debugging info for async remote notification.
747 ** Command parameter changes are now notified using new async record
748 "=cmd-param-changed".
749 ** Trace frame changes caused by command "tfind" are now notified using
750 new async record "=traceframe-changed".
751 ** The creation, deletion and modification of trace state variables
752 are now notified using new async records "=tsv-created",
753 "=tsv-deleted" and "=tsv-modified".
754 ** The start and stop of process record are now notified using new
755 async record "=record-started" and "=record-stopped".
756 ** Memory changes are now notified using new async record
758 ** The data-disassemble command response will include a "fullname" field
759 containing the absolute file name when source has been requested.
760 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
761 command, to allow pattern filling of memory areas.
762 ** New commands "-catch-load"/"-catch-unload" added for intercepting
763 library load/unload events.
764 ** The response to breakpoint commands and breakpoint async records
765 includes an "installed" field containing a boolean state about each
766 non-pending tracepoint location is whether installed on target or not.
767 ** Output of the "-trace-status" command includes a "trace-file" field
768 containing the name of the trace file being examined. This field is
769 optional, and only present when examining a trace file.
770 ** The "fullname" field is now always present along with the "file" field,
771 even if the file cannot be found by GDB.
773 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
774 You must have the LZMA library available when configuring GDB for this
775 feature to be enabled. For more information, see:
776 http://fedoraproject.org/wiki/Features/MiniDebugInfo
781 Set the size of trace buffer. The remote stub reports support for this
782 packet to gdb's qSupported query.
785 Enable Branch Trace Store (BTS)-based branch tracing for the current
786 thread. The remote stub reports support for this packet to gdb's
790 Disable branch tracing for the current thread. The remote stub reports
791 support for this packet to gdb's qSupported query.
794 Read the traced branches for the current thread. The remote stub
795 reports support for this packet to gdb's qSupported query.
797 *** Changes in GDB 7.5
799 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
800 for more x32 ABI info.
802 * GDB now supports access to MIPS DSP registers on Linux targets.
804 * GDB now supports debugging microMIPS binaries.
806 * The "info os" command on GNU/Linux can now display information on
807 several new classes of objects managed by the operating system:
808 "info os procgroups" lists process groups
809 "info os files" lists file descriptors
810 "info os sockets" lists internet-domain sockets
811 "info os shm" lists shared-memory regions
812 "info os semaphores" lists semaphores
813 "info os msg" lists message queues
814 "info os modules" lists loaded kernel modules
816 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
817 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
818 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
819 options and inspect the probe arguments using the new $_probe_arg family
820 of convenience variables. You can obtain more information about SystemTap
821 in <http://sourceware.org/systemtap/>.
823 * GDB now supports reversible debugging on ARM, it allows you to
824 debug basic ARM and THUMB instructions, and provides
825 record/replay support.
827 * The option "symbol-reloading" has been deleted as it is no longer used.
831 ** GDB commands implemented in Python can now be put in command class
834 ** The "maint set python print-stack on|off" is now deleted.
836 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
837 apply "flag enum"-style pretty-printing to any enum.
839 ** gdb.lookup_symbol can now work when there is no current frame.
841 ** gdb.Symbol now has a 'line' attribute, holding the line number in
842 the source at which the symbol was defined.
844 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
845 method 'value'. The former indicates whether the symbol needs a
846 frame in order to compute its value, and the latter computes the
849 ** A new method 'referenced_value' on gdb.Value objects which can
850 dereference pointer as well as C++ reference values.
852 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
853 which return the global and static blocks (as gdb.Block objects),
854 of the underlying symbol table, respectively.
856 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
857 object associated with a PC value.
859 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
860 of the address range occupied by code for the current source line.
862 * Go language support.
863 GDB now supports debugging programs written in the Go programming
866 * GDBserver now supports stdio connections.
867 E.g. (gdb) target remote | ssh myhost gdbserver - hello
869 * The binary "gdbtui" can no longer be built or installed.
870 Use "gdb -tui" instead.
872 * GDB will now print "flag" enums specially. A flag enum is one where
873 all the enumerator values have no bits in common when pairwise
874 "and"ed. When printing a value whose type is a flag enum, GDB will
875 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
876 (gdb) print (enum E) 3
879 * The filename part of a linespec will now match trailing components
880 of a source file name. For example, "break gcc/expr.c:1000" will
881 now set a breakpoint in build/gcc/expr.c, but not
884 * The "info proc" and "generate-core-file" commands will now also
885 work on remote targets connected to GDBserver on Linux.
887 * The command "info catch" has been removed. It has been disabled
890 * The "catch exception" and "catch assert" commands now accept
891 a condition at the end of the command, much like the "break"
892 command does. For instance:
894 (gdb) catch exception Constraint_Error if Barrier = True
896 Previously, it was possible to add a condition to such catchpoints,
897 but it had to be done as a second step, after the catchpoint had been
898 created, using the "condition" command.
900 * The "info static-tracepoint-marker" command will now also work on
901 native Linux targets with in-process agent.
903 * GDB can now set breakpoints on inlined functions.
905 * The .gdb_index section has been updated to include symbols for
906 inlined functions. GDB will ignore older .gdb_index sections by
907 default, which could cause symbol files to be loaded more slowly
908 until their .gdb_index sections can be recreated. The new command
909 "set use-deprecated-index-sections on" will cause GDB to use any older
910 .gdb_index sections it finds. This will restore performance, but the
911 ability to set breakpoints on inlined functions will be lost in symbol
912 files with older .gdb_index sections.
914 The .gdb_index section has also been updated to record more information
915 about each symbol. This speeds up the "info variables", "info functions"
916 and "info types" commands when used with programs having the .gdb_index
917 section, as well as speeding up debugging with shared libraries using
918 the .gdb_index section.
920 * Ada support for GDB/MI Variable Objects has been added.
922 * GDB can now support 'breakpoint always-inserted mode' in 'record'
927 ** New command -info-os is the MI equivalent of "info os".
929 ** Output logs ("set logging" and related) now include MI output.
933 ** "set use-deprecated-index-sections on|off"
934 "show use-deprecated-index-sections on|off"
935 Controls the use of deprecated .gdb_index sections.
937 ** "catch load" and "catch unload" can be used to stop when a shared
938 library is loaded or unloaded, respectively.
940 ** "enable count" can be used to auto-disable a breakpoint after
943 ** "info vtbl" can be used to show the virtual method tables for
944 C++ and Java objects.
946 ** "explore" and its sub commands "explore value" and "explore type"
947 can be used to recursively explore values and types of
948 expressions. These commands are available only if GDB is
949 configured with '--with-python'.
951 ** "info auto-load" shows status of all kinds of auto-loaded files,
952 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
953 sequences of commands files, "info auto-load python-scripts"
954 shows status of auto-loading Python script files,
955 "info auto-load local-gdbinit" shows status of loading init file
956 (.gdbinit) from current directory and "info auto-load libthread-db" shows
957 status of inferior specific thread debugging shared library loading.
959 ** "info auto-load-scripts", "set auto-load-scripts on|off"
960 and "show auto-load-scripts" commands have been deprecated, use their
961 "info auto-load python-scripts", "set auto-load python-scripts on|off"
962 and "show auto-load python-scripts" counterparts instead.
964 ** "dprintf location,format,args..." creates a dynamic printf, which
965 is basically a breakpoint that does a printf and immediately
966 resumes your program's execution, so it is like a printf that you
967 can insert dynamically at runtime instead of at compiletime.
969 ** "set print symbol"
971 Controls whether GDB attempts to display the symbol, if any,
972 corresponding to addresses it prints. This defaults to "on", but
973 you can set it to "off" to restore GDB's previous behavior.
975 * Deprecated commands
977 ** For the Renesas Super-H architecture, the "regs" command has been
978 deprecated, and "info all-registers" should be used instead.
982 Renesas RL78 rl78-*-elf
983 HP OpenVMS ia64 ia64-hp-openvms*
985 * GDBserver supports evaluation of breakpoint conditions. When
986 support is advertised by GDBserver, GDB may be told to send the
987 breakpoint conditions in bytecode form to GDBserver. GDBserver
988 will only report the breakpoint trigger to GDB when its condition
994 show mips compression
995 Select the compressed ISA encoding used in functions that have no symbol
996 information available. The encoding can be set to either of:
999 and is updated automatically from ELF file flags if available.
1001 set breakpoint condition-evaluation
1002 show breakpoint condition-evaluation
1003 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1004 GDBserver ("target"). Default option "auto" chooses the most efficient
1006 This option can improve debugger efficiency depending on the speed of the
1010 Disable auto-loading globally.
1013 Show auto-loading setting of all kinds of auto-loaded files.
1015 set auto-load gdb-scripts on|off
1016 show auto-load gdb-scripts
1017 Control auto-loading of GDB canned sequences of commands files.
1019 set auto-load python-scripts on|off
1020 show auto-load python-scripts
1021 Control auto-loading of Python script files.
1023 set auto-load local-gdbinit on|off
1024 show auto-load local-gdbinit
1025 Control loading of init file (.gdbinit) from current directory.
1027 set auto-load libthread-db on|off
1028 show auto-load libthread-db
1029 Control auto-loading of inferior specific thread debugging shared library.
1031 set auto-load scripts-directory <dir1>[:<dir2>...]
1032 show auto-load scripts-directory
1033 Set a list of directories from which to load auto-loaded scripts.
1034 Automatically loaded Python scripts and GDB scripts are located in one
1035 of the directories listed by this option.
1036 The delimiter (':' above) may differ according to the host platform.
1038 set auto-load safe-path <dir1>[:<dir2>...]
1039 show auto-load safe-path
1040 Set a list of directories from which it is safe to auto-load files.
1041 The delimiter (':' above) may differ according to the host platform.
1043 set debug auto-load on|off
1044 show debug auto-load
1045 Control display of debugging info for auto-loading the files above.
1047 set dprintf-style gdb|call|agent
1049 Control the way in which a dynamic printf is performed; "gdb"
1050 requests a GDB printf command, while "call" causes dprintf to call a
1051 function in the inferior. "agent" requests that the target agent
1052 (such as GDBserver) do the printing.
1054 set dprintf-function <expr>
1055 show dprintf-function
1056 set dprintf-channel <expr>
1057 show dprintf-channel
1058 Set the function and optional first argument to the call when using
1059 the "call" style of dynamic printf.
1061 set disconnected-dprintf on|off
1062 show disconnected-dprintf
1063 Control whether agent-style dynamic printfs continue to be in effect
1064 after GDB disconnects.
1066 * New configure options
1068 --with-auto-load-dir
1069 Configure default value for the 'set auto-load scripts-directory'
1070 setting above. It defaults to '$debugdir:$datadir/auto-load',
1071 $debugdir representing global debugging info directories (available
1072 via 'show debug-file-directory') and $datadir representing GDB's data
1073 directory (available via 'show data-directory').
1075 --with-auto-load-safe-path
1076 Configure default value for the 'set auto-load safe-path' setting
1077 above. It defaults to the --with-auto-load-dir setting.
1079 --without-auto-load-safe-path
1080 Set 'set auto-load safe-path' to '/', effectively disabling this
1083 * New remote packets
1085 z0/z1 conditional breakpoints extension
1087 The z0/z1 breakpoint insertion packets have been extended to carry
1088 a list of conditional expressions over to the remote stub depending on the
1089 condition evaluation mode. The use of this extension can be controlled
1090 via the "set remote conditional-breakpoints-packet" command.
1094 Specify the signals which the remote stub may pass to the debugged
1095 program without GDB involvement.
1097 * New command line options
1099 --init-command=FILE, -ix Like --command, -x but execute it
1100 before loading inferior.
1101 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1102 execute it before loading inferior.
1104 *** Changes in GDB 7.4
1106 * GDB now handles ambiguous linespecs more consistently; the existing
1107 FILE:LINE support has been expanded to other types of linespecs. A
1108 breakpoint will now be set on all matching locations in all
1109 inferiors, and locations will be added or removed according to
1112 * GDB now allows you to skip uninteresting functions and files when
1113 stepping with the "skip function" and "skip file" commands.
1115 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1116 and "show remote hardware-watchpoint-length-limit". These allows to
1117 set or show the maximum length limit (in bytes) of a remote
1118 target hardware watchpoint.
1120 This allows e.g. to use "unlimited" hardware watchpoints with the
1121 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1122 watchpoints are slower than real hardware watchpoints but are
1123 significantly faster than gdb software watchpoints.
1127 ** The register_pretty_printer function in module gdb.printing now takes
1128 an optional `replace' argument. If True, the new printer replaces any
1131 ** The "maint set python print-stack on|off" command has been
1132 deprecated and will be deleted in GDB 7.5.
1133 A new command: "set python print-stack none|full|message" has
1134 replaced it. Additionally, the default for "print-stack" is
1135 now "message", which just prints the error message without
1138 ** A prompt substitution hook (prompt_hook) is now available to the
1141 ** A new Python module, gdb.prompt has been added to the GDB Python
1142 modules library. This module provides functionality for
1143 escape sequences in prompts (used by set/show
1144 extended-prompt). These escape sequences are replaced by their
1145 corresponding value.
1147 ** Python commands and convenience-functions located in
1148 'data-directory'/python/gdb/command and
1149 'data-directory'/python/gdb/function are now automatically loaded
1152 ** Blocks now provide four new attributes. global_block and
1153 static_block will return the global and static blocks
1154 respectively. is_static and is_global are boolean attributes
1155 that indicate if the block is one of those two types.
1157 ** Symbols now provide the "type" attribute, the type of the symbol.
1159 ** The "gdb.breakpoint" function has been deprecated in favor of
1162 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1163 of a function. This class is based on the "finish" command
1164 available in the CLI.
1166 ** Type objects for struct and union types now allow access to
1167 the fields using standard Python dictionary (mapping) methods.
1168 For example, "some_type['myfield']" now works, as does
1169 "some_type.items()".
1171 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1174 ** A new function, "deep_items" has been added to the gdb.types
1175 module in the GDB Python modules library. This function returns
1176 an iterator over the fields of a struct or union type. Unlike
1177 the standard Python "iteritems" method, it will recursively traverse
1178 any anonymous fields.
1182 ** "*stopped" events can report several new "reason"s, such as
1185 ** Breakpoint changes are now notified using new async records, like
1186 "=breakpoint-modified".
1188 ** New command -ada-task-info.
1190 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1191 $sdir specifies the default system locations of shared libraries.
1192 $pdir specifies the directory where the libpthread used by the application
1195 GDB no longer looks in $sdir and $pdir after it has searched the directories
1196 mentioned in libthread-db-search-path. If you want to search those
1197 directories, they must be specified in libthread-db-search-path.
1198 The default value of libthread-db-search-path on GNU/Linux and Solaris
1199 systems is now "$sdir:$pdir".
1201 $pdir is not supported by gdbserver, it is currently ignored.
1202 $sdir is supported by gdbserver.
1204 * New configure option --with-iconv-bin.
1205 When using the internationalization support like the one in the GNU C
1206 library, GDB will invoke the "iconv" program to get a list of supported
1207 character sets. If this program lives in a non-standard location, one can
1208 use this option to specify where to find it.
1210 * When natively debugging programs on PowerPC BookE processors running
1211 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1212 watchpoints, which specify a mask in addition to an address to watch.
1213 The mask specifies that some bits of an address (the bits which are
1214 reset in the mask) should be ignored when matching the address accessed
1215 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1216 section in the user manual for more details.
1218 * The new option --once causes GDBserver to stop listening for connections once
1219 the first connection is made. The listening port used by GDBserver will
1220 become available after that.
1222 * New commands "info macros" and "alias" have been added.
1224 * New function parameters suffix @entry specifies value of function parameter
1225 at the time the function got called. Entry values are available only since
1231 "!" is now an alias of the "shell" command.
1232 Note that no space is needed between "!" and SHELL COMMAND.
1236 watch EXPRESSION mask MASK_VALUE
1237 The watch command now supports the mask argument which allows creation
1238 of masked watchpoints, if the current architecture supports this feature.
1240 info auto-load-scripts [REGEXP]
1241 This command was formerly named "maintenance print section-scripts".
1242 It is now generally useful and is no longer a maintenance-only command.
1244 info macro [-all] [--] MACRO
1245 The info macro command has new options `-all' and `--'. The first for
1246 printing all definitions of a macro. The second for explicitly specifying
1247 the end of arguments and the beginning of the macro name in case the macro
1248 name starts with a hyphen.
1250 collect[/s] EXPRESSIONS
1251 The tracepoint collect command now takes an optional modifier "/s"
1252 that directs it to dereference pointer-to-character types and
1253 collect the bytes of memory up to a zero byte. The behavior is
1254 similar to what you see when you use the regular print command on a
1255 string. An optional integer following the "/s" sets a bound on the
1256 number of bytes that will be collected.
1259 The trace start command now interprets any supplied arguments as a
1260 note to be recorded with the trace run, with an effect similar to
1261 setting the variable trace-notes.
1264 The trace stop command now interprets any arguments as a note to be
1265 mentioned along with the tstatus report that the trace was stopped
1266 with a command. The effect is similar to setting the variable
1269 * Tracepoints can now be enabled and disabled at any time after a trace
1270 experiment has been started using the standard "enable" and "disable"
1271 commands. It is now possible to start a trace experiment with no enabled
1272 tracepoints; GDB will display a warning, but will allow the experiment to
1273 begin, assuming that tracepoints will be enabled as needed while the trace
1276 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1277 locations with 4-byte instructions, when they were previously
1278 limited to locations with instructions of 5 bytes or longer.
1282 set debug dwarf2-read
1283 show debug dwarf2-read
1284 Turns on or off display of debugging messages related to reading
1285 DWARF debug info. The default is off.
1287 set debug symtab-create
1288 show debug symtab-create
1289 Turns on or off display of debugging messages related to symbol table
1290 creation. The default is off.
1293 show extended-prompt
1294 Set the GDB prompt, and allow escape sequences to be inserted to
1295 display miscellaneous information (see 'help set extended-prompt'
1296 for the list of sequences). This prompt (and any information
1297 accessed through the escape sequences) is updated every time the
1298 prompt is displayed.
1300 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1301 show print entry-values
1302 Set printing of frame argument values at function entry. In some cases
1303 GDB can determine the value of function argument which was passed by the
1304 function caller, even if the value was modified inside the called function.
1306 set debug entry-values
1307 show debug entry-values
1308 Control display of debugging info for determining frame argument values at
1309 function entry and virtual tail call frames.
1311 set basenames-may-differ
1312 show basenames-may-differ
1313 Set whether a source file may have multiple base names.
1314 (A "base name" is the name of a file with the directory part removed.
1315 Example: The base name of "/home/user/hello.c" is "hello.c".)
1316 If set, GDB will canonicalize file names (e.g., expand symlinks)
1317 before comparing them. Canonicalization is an expensive operation,
1318 but it allows the same file be known by more than one base name.
1319 If not set (the default), all source files are assumed to have just
1320 one base name, and gdb will do file name comparisons more efficiently.
1326 Set a user name and notes for the current and any future trace runs.
1327 This is useful for long-running and/or disconnected traces, to
1328 inform others (or yourself) as to who is running the trace, supply
1329 contact information, or otherwise explain what is going on.
1331 set trace-stop-notes
1332 show trace-stop-notes
1333 Set a note attached to the trace run, that is displayed when the
1334 trace has been stopped by a tstop command. This is useful for
1335 instance as an explanation, if you are stopping a trace run that was
1336 started by someone else.
1338 * New remote packets
1342 Dynamically enable a tracepoint in a started trace experiment.
1346 Dynamically disable a tracepoint in a started trace experiment.
1350 Set the user and notes of the trace run.
1354 Query the current status of a tracepoint.
1358 Query the minimum length of instruction at which a fast tracepoint may
1361 * Dcache size (number of lines) and line-size are now runtime-configurable
1362 via "set dcache line" and "set dcache line-size" commands.
1366 Texas Instruments TMS320C6x tic6x-*-*
1370 Renesas RL78 rl78-*-elf
1372 *** Changes in GDB 7.3.1
1374 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1376 *** Changes in GDB 7.3
1378 * GDB has a new command: "thread find [REGEXP]".
1379 It finds the thread id whose name, target id, or thread extra info
1380 matches the given regular expression.
1382 * The "catch syscall" command now works on mips*-linux* targets.
1384 * The -data-disassemble MI command now supports modes 2 and 3 for
1385 dumping the instruction opcodes.
1387 * New command line options
1389 -data-directory DIR Specify DIR as the "data-directory".
1390 This is mostly for testing purposes.
1392 * The "maint set python auto-load on|off" command has been renamed to
1393 "set auto-load-scripts on|off".
1395 * GDB has a new command: "set directories".
1396 It is like the "dir" command except that it replaces the
1397 source path list instead of augmenting it.
1399 * GDB now understands thread names.
1401 On GNU/Linux, "info threads" will display the thread name as set by
1402 prctl or pthread_setname_np.
1404 There is also a new command, "thread name", which can be used to
1405 assign a name internally for GDB to display.
1408 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1409 has been integrated into GDB.
1413 ** The function gdb.Write now accepts an optional keyword 'stream'.
1414 This keyword, when provided, will direct the output to either
1415 stdout, stderr, or GDB's logging output.
1417 ** Parameters can now be be sub-classed in Python, and in particular
1418 you may implement the get_set_doc and get_show_doc functions.
1419 This improves how Parameter set/show documentation is processed
1420 and allows for more dynamic content.
1422 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1423 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1424 have an is_valid method.
1426 ** Breakpoints can now be sub-classed in Python, and in particular
1427 you may implement a 'stop' function that is executed each time
1428 the inferior reaches that breakpoint.
1430 ** New function gdb.lookup_global_symbol looks up a global symbol.
1432 ** GDB values in Python are now callable if the value represents a
1433 function. For example, if 'some_value' represents a function that
1434 takes two integer parameters and returns a value, you can call
1435 that function like so:
1437 result = some_value (10,20)
1439 ** Module gdb.types has been added.
1440 It contains a collection of utilities for working with gdb.Types objects:
1441 get_basic_type, has_field, make_enum_dict.
1443 ** Module gdb.printing has been added.
1444 It contains utilities for writing and registering pretty-printers.
1445 New classes: PrettyPrinter, SubPrettyPrinter,
1446 RegexpCollectionPrettyPrinter.
1447 New function: register_pretty_printer.
1449 ** New commands "info pretty-printers", "enable pretty-printer" and
1450 "disable pretty-printer" have been added.
1452 ** gdb.parameter("directories") is now available.
1454 ** New function gdb.newest_frame returns the newest frame in the
1457 ** The gdb.InferiorThread class has a new "name" attribute. This
1458 holds the thread's name.
1460 ** Python Support for Inferior events.
1461 Python scripts can add observers to be notified of events
1462 occurring in the process being debugged.
1463 The following events are currently supported:
1464 - gdb.events.cont Continue event.
1465 - gdb.events.exited Inferior exited event.
1466 - gdb.events.stop Signal received, and Breakpoint hit events.
1470 ** GDB now puts template parameters in scope when debugging in an
1471 instantiation. For example, if you have:
1473 template<int X> int func (void) { return X; }
1475 then if you step into func<5>, "print X" will show "5". This
1476 feature requires proper debuginfo support from the compiler; it
1477 was added to GCC 4.5.
1479 ** The motion commands "next", "finish", "until", and "advance" now
1480 work better when exceptions are thrown. In particular, GDB will
1481 no longer lose control of the inferior; instead, the GDB will
1482 stop the inferior at the point at which the exception is caught.
1483 This functionality requires a change in the exception handling
1484 code that was introduced in GCC 4.5.
1486 * GDB now follows GCC's rules on accessing volatile objects when
1487 reading or writing target state during expression evaluation.
1488 One notable difference to prior behavior is that "print x = 0"
1489 no longer generates a read of x; the value of the assignment is
1490 now always taken directly from the value being assigned.
1492 * GDB now has some support for using labels in the program's source in
1493 linespecs. For instance, you can use "advance label" to continue
1494 execution to a label.
1496 * GDB now has support for reading and writing a new .gdb_index
1497 section. This section holds a fast index of DWARF debugging
1498 information and can be used to greatly speed up GDB startup and
1499 operation. See the documentation for `save gdb-index' for details.
1501 * The "watch" command now accepts an optional "-location" argument.
1502 When used, this causes GDB to watch the memory referred to by the
1503 expression. Such a watchpoint is never deleted due to it going out
1506 * GDB now supports thread debugging of core dumps on GNU/Linux.
1508 GDB now activates thread debugging using the libthread_db library
1509 when debugging GNU/Linux core dumps, similarly to when debugging
1510 live processes. As a result, when debugging a core dump file, GDB
1511 is now able to display pthread_t ids of threads. For example, "info
1512 threads" shows the same output as when debugging the process when it
1513 was live. In earlier releases, you'd see something like this:
1516 * 1 LWP 6780 main () at main.c:10
1518 While now you see this:
1521 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1523 It is also now possible to inspect TLS variables when debugging core
1526 When debugging a core dump generated on a machine other than the one
1527 used to run GDB, you may need to point GDB at the correct
1528 libthread_db library with the "set libthread-db-search-path"
1529 command. See the user manual for more details on this command.
1531 * When natively debugging programs on PowerPC BookE processors running
1532 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1533 which stop execution of the inferior whenever it executes an instruction
1534 at any address within the specified range. See the "PowerPC Embedded"
1535 section in the user manual for more details.
1537 * New features in the GDB remote stub, GDBserver
1539 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1540 and i686 LynxOS (version 5.x).
1542 ** GDBserver is now supported on Blackfin Linux.
1544 * New native configurations
1546 ia64 HP-UX ia64-*-hpux*
1550 Analog Devices, Inc. Blackfin Processor bfin-*
1552 * Ada task switching is now supported on sparc-elf targets when
1553 debugging a program using the Ravenscar Profile. For more information,
1554 see the "Tasking Support when using the Ravenscar Profile" section
1555 in the GDB user manual.
1557 * Guile support was removed.
1559 * New features in the GNU simulator
1561 ** The --map-info flag lists all known core mappings.
1563 ** CFI flashes may be simulated via the "cfi" device.
1565 *** Changes in GDB 7.2
1567 * Shared library support for remote targets by default
1569 When GDB is configured for a generic, non-OS specific target, like
1570 for example, --target=arm-eabi or one of the many *-*-elf targets,
1571 GDB now queries remote stubs for loaded shared libraries using the
1572 `qXfer:libraries:read' packet. Previously, shared library support
1573 was always disabled for such configurations.
1577 ** Argument Dependent Lookup (ADL)
1579 In C++ ADL lookup directs function search to the namespaces of its
1580 arguments even if the namespace has not been imported.
1590 Here the compiler will search for `foo' in the namespace of 'b'
1591 and find A::foo. GDB now supports this. This construct is commonly
1592 used in the Standard Template Library for operators.
1594 ** Improved User Defined Operator Support
1596 In addition to member operators, GDB now supports lookup of operators
1597 defined in a namespace and imported with a `using' directive, operators
1598 defined in the global scope, operators imported implicitly from an
1599 anonymous namespace, and the ADL operators mentioned in the previous
1601 GDB now also supports proper overload resolution for all the previously
1602 mentioned flavors of operators.
1604 ** static const class members
1606 Printing of static const class members that are initialized in the
1607 class definition has been fixed.
1609 * Windows Thread Information Block access.
1611 On Windows targets, GDB now supports displaying the Windows Thread
1612 Information Block (TIB) structure. This structure is visible either
1613 by using the new command `info w32 thread-information-block' or, by
1614 dereferencing the new convenience variable named `$_tlb', a
1615 thread-specific pointer to the TIB. This feature is also supported
1616 when remote debugging using GDBserver.
1618 * Static tracepoints
1620 Static tracepoints are calls in the user program into a tracing
1621 library. One such library is a port of the LTTng kernel tracer to
1622 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1623 When debugging with GDBserver, GDB now supports combining the GDB
1624 tracepoint machinery with such libraries. For example: the user can
1625 use GDB to probe a static tracepoint marker (a call from the user
1626 program into the tracing library) with the new "strace" command (see
1627 "New commands" below). This creates a "static tracepoint" in the
1628 breakpoint list, that can be manipulated with the same feature set
1629 as fast and regular tracepoints. E.g., collect registers, local and
1630 global variables, collect trace state variables, and define
1631 tracepoint conditions. In addition, the user can collect extra
1632 static tracepoint marker specific data, by collecting the new
1633 $_sdata internal variable. When analyzing the trace buffer, you can
1634 inspect $_sdata like any other variable available to GDB. For more
1635 information, see the "Tracepoints" chapter in GDB user manual. New
1636 remote packets have been defined to support static tracepoints, see
1637 the "New remote packets" section below.
1639 * Better reconstruction of tracepoints after disconnected tracing
1641 GDB will attempt to download the original source form of tracepoint
1642 definitions when starting a trace run, and then will upload these
1643 upon reconnection to the target, resulting in a more accurate
1644 reconstruction of the tracepoints that are in use on the target.
1648 You can now exercise direct control over the ways that GDB can
1649 affect your program. For instance, you can disallow the setting of
1650 breakpoints, so that the program can run continuously (assuming
1651 non-stop mode). In addition, the "observer" variable is available
1652 to switch all of the different controls; in observer mode, GDB
1653 cannot affect the target's behavior at all, which is useful for
1654 tasks like diagnosing live systems in the field.
1656 * The new convenience variable $_thread holds the number of the
1659 * New remote packets
1663 Return the address of the Windows Thread Information Block of a given thread.
1667 In response to several of the tracepoint packets, the target may now
1668 also respond with a number of intermediate `qRelocInsn' request
1669 packets before the final result packet, to have GDB handle
1670 relocating an instruction to execute at a different address. This
1671 is particularly useful for stubs that support fast tracepoints. GDB
1672 reports support for this feature in the qSupported packet.
1676 List static tracepoint markers in the target program.
1680 List static tracepoint markers at a given address in the target
1683 qXfer:statictrace:read
1685 Read the static trace data collected (by a `collect $_sdata'
1686 tracepoint action). The remote stub reports support for this packet
1687 to gdb's qSupported query.
1691 Send the current settings of GDB's permission flags.
1695 Send part of the source (textual) form of a tracepoint definition,
1696 which includes location, conditional, and action list.
1698 * The source command now accepts a -s option to force searching for the
1699 script in the source search path even if the script name specifies
1702 * New features in the GDB remote stub, GDBserver
1704 - GDBserver now support tracepoints (including fast tracepoints, and
1705 static tracepoints). The feature is currently supported by the
1706 i386-linux and amd64-linux builds. See the "Tracepoints support
1707 in gdbserver" section in the manual for more information.
1709 GDBserver JIT compiles the tracepoint's conditional agent
1710 expression bytecode into native code whenever possible for low
1711 overhead dynamic tracepoints conditionals. For such tracepoints,
1712 an expression that examines program state is evaluated when the
1713 tracepoint is reached, in order to determine whether to capture
1714 trace data. If the condition is simple and false, processing the
1715 tracepoint finishes very quickly and no data is gathered.
1717 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1718 for static tracepoints support.
1720 - GDBserver now supports x86_64 Windows 64-bit debugging.
1722 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1723 it understands register description.
1725 * The --batch flag now disables pagination and queries.
1727 * X86 general purpose registers
1729 GDB now supports reading/writing byte, word and double-word x86
1730 general purpose registers directly. This means you can use, say,
1731 $ah or $ax to refer, respectively, to the byte register AH and
1732 16-bit word register AX that are actually portions of the 32-bit
1733 register EAX or 64-bit register RAX.
1735 * The `commands' command now accepts a range of breakpoints to modify.
1736 A plain `commands' following a command that creates multiple
1737 breakpoints affects all the breakpoints set by that command. This
1738 applies to breakpoints set by `rbreak', and also applies when a
1739 single `break' command creates multiple breakpoints (e.g.,
1740 breakpoints on overloaded c++ functions).
1742 * The `rbreak' command now accepts a filename specification as part of
1743 its argument, limiting the functions selected by the regex to those
1744 in the specified file.
1746 * Support for remote debugging Windows and SymbianOS shared libraries
1747 from Unix hosts has been improved. Non Windows GDB builds now can
1748 understand target reported file names that follow MS-DOS based file
1749 system semantics, such as file names that include drive letters and
1750 use the backslash character as directory separator. This makes it
1751 possible to transparently use the "set sysroot" and "set
1752 solib-search-path" on Unix hosts to point as host copies of the
1753 target's shared libraries. See the new command "set
1754 target-file-system-kind" described below, and the "Commands to
1755 specify files" section in the user manual for more information.
1759 eval template, expressions...
1760 Convert the values of one or more expressions under the control
1761 of the string template to a command line, and call it.
1763 set target-file-system-kind unix|dos-based|auto
1764 show target-file-system-kind
1765 Set or show the assumed file system kind for target reported file
1768 save breakpoints <filename>
1769 Save all current breakpoint definitions to a file suitable for use
1770 in a later debugging session. To read the saved breakpoint
1771 definitions, use the `source' command.
1773 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1776 info static-tracepoint-markers
1777 Display information about static tracepoint markers in the target.
1779 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1780 Define a static tracepoint by probing a marker at the given
1781 function, line, address, or marker ID.
1785 Enable and disable observer mode.
1787 set may-write-registers on|off
1788 set may-write-memory on|off
1789 set may-insert-breakpoints on|off
1790 set may-insert-tracepoints on|off
1791 set may-insert-fast-tracepoints on|off
1792 set may-interrupt on|off
1793 Set individual permissions for GDB effects on the target. Note that
1794 some of these settings can have undesirable or surprising
1795 consequences, particularly when changed in the middle of a session.
1796 For instance, disabling the writing of memory can prevent
1797 breakpoints from being inserted, cause single-stepping to fail, or
1798 even crash your program, if you disable after breakpoints have been
1799 inserted. However, GDB should not crash.
1801 set record memory-query on|off
1802 show record memory-query
1803 Control whether to stop the inferior if memory changes caused
1804 by an instruction cannot be recorded.
1809 The disassemble command now supports "start,+length" form of two arguments.
1813 ** GDB now provides a new directory location, called the python directory,
1814 where Python scripts written for GDB can be installed. The location
1815 of that directory is <data-directory>/python, where <data-directory>
1816 is the GDB data directory. For more details, see section `Scripting
1817 GDB using Python' in the manual.
1819 ** The GDB Python API now has access to breakpoints, symbols, symbol
1820 tables, program spaces, inferiors, threads and frame's code blocks.
1821 Additionally, GDB Parameters can now be created from the API, and
1822 manipulated via set/show in the CLI.
1824 ** New functions gdb.target_charset, gdb.target_wide_charset,
1825 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1827 ** New exception gdb.GdbError.
1829 ** Pretty-printers are now also looked up in the current program space.
1831 ** Pretty-printers can now be individually enabled and disabled.
1833 ** GDB now looks for names of Python scripts to auto-load in a
1834 special section named `.debug_gdb_scripts', in addition to looking
1835 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1837 * Tracepoint actions were unified with breakpoint commands. In particular,
1838 there are no longer differences in "info break" output for breakpoints and
1839 tracepoints and the "commands" command can be used for both tracepoints and
1840 regular breakpoints.
1844 ARM Symbian arm*-*-symbianelf*
1846 * D language support.
1847 GDB now supports debugging programs written in the D programming
1850 * GDB now supports the extended ptrace interface for PowerPC which is
1851 available since Linux kernel version 2.6.34. This automatically enables
1852 any hardware breakpoints and additional hardware watchpoints available in
1853 the processor. The old ptrace interface exposes just one hardware
1854 watchpoint and no hardware breakpoints.
1856 * GDB is now able to use the Data Value Compare (DVC) register available on
1857 embedded PowerPC processors to implement in hardware simple watchpoint
1858 conditions of the form:
1860 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1862 This works in native GDB running on Linux kernels with the extended ptrace
1863 interface mentioned above.
1865 *** Changes in GDB 7.1
1869 ** Namespace Support
1871 GDB now supports importing of namespaces in C++. This enables the
1872 user to inspect variables from imported namespaces. Support for
1873 namepace aliasing has also been added. So, if a namespace is
1874 aliased in the current scope (e.g. namepace C=A; ) the user can
1875 print variables using the alias (e.g. (gdb) print C::x).
1879 All known bugs relating to the printing of virtual base class were
1880 fixed. It is now possible to call overloaded static methods using a
1885 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1886 and reinterpret_cast<> are now handled by the C++ expression parser.
1890 Xilinx MicroBlaze microblaze-*-*
1895 Xilinx MicroBlaze microblaze
1898 * Multi-program debugging.
1900 GDB now has support for multi-program (a.k.a. multi-executable or
1901 multi-exec) debugging. This allows for debugging multiple inferiors
1902 simultaneously each running a different program under the same GDB
1903 session. See "Debugging Multiple Inferiors and Programs" in the
1904 manual for more information. This implied some user visible changes
1905 in the multi-inferior support. For example, "info inferiors" now
1906 lists inferiors that are not running yet or that have exited
1907 already. See also "New commands" and "New options" below.
1909 * New tracing features
1911 GDB's tracepoint facility now includes several new features:
1913 ** Trace state variables
1915 GDB tracepoints now include support for trace state variables, which
1916 are variables managed by the target agent during a tracing
1917 experiment. They are useful for tracepoints that trigger each
1918 other, so for instance one tracepoint can count hits in a variable,
1919 and then a second tracepoint has a condition that is true when the
1920 count reaches a particular value. Trace state variables share the
1921 $-syntax of GDB convenience variables, and can appear in both
1922 tracepoint actions and condition expressions. Use the "tvariable"
1923 command to create, and "info tvariables" to view; see "Trace State
1924 Variables" in the manual for more detail.
1928 GDB now includes an option for defining fast tracepoints, which
1929 targets may implement more efficiently, such as by installing a jump
1930 into the target agent rather than a trap instruction. The resulting
1931 speedup can be by two orders of magnitude or more, although the
1932 tradeoff is that some program locations on some target architectures
1933 might not allow fast tracepoint installation, for instance if the
1934 instruction to be replaced is shorter than the jump. To request a
1935 fast tracepoint, use the "ftrace" command, with syntax identical to
1936 the regular trace command.
1938 ** Disconnected tracing
1940 It is now possible to detach GDB from the target while it is running
1941 a trace experiment, then reconnect later to see how the experiment
1942 is going. In addition, a new variable disconnected-tracing lets you
1943 tell the target agent whether to continue running a trace if the
1944 connection is lost unexpectedly.
1948 GDB now has the ability to save the trace buffer into a file, and
1949 then use that file as a target, similarly to you can do with
1950 corefiles. You can select trace frames, print data that was
1951 collected in them, and use tstatus to display the state of the
1952 tracing run at the moment that it was saved. To create a trace
1953 file, use "tsave <filename>", and to use it, do "target tfile
1956 ** Circular trace buffer
1958 You can ask the target agent to handle the trace buffer as a
1959 circular buffer, discarding the oldest trace frames to make room for
1960 newer ones, by setting circular-trace-buffer to on. This feature may
1961 not be available for all target agents.
1966 The disassemble command, when invoked with two arguments, now requires
1967 the arguments to be comma-separated.
1970 The info variables command now displays variable definitions. Files
1971 which only declare a variable are not shown.
1974 The source command is now capable of sourcing Python scripts.
1975 This feature is dependent on the debugger being build with Python
1978 Related to this enhancement is also the introduction of a new command
1979 "set script-extension" (see below).
1981 * New commands (for set/show, see "New options" below)
1983 record save [<FILENAME>]
1984 Save a file (in core file format) containing the process record
1985 execution log for replay debugging at a later time.
1987 record restore <FILENAME>
1988 Restore the process record execution log that was saved at an
1989 earlier time, for replay debugging.
1991 add-inferior [-copies <N>] [-exec <FILENAME>]
1994 clone-inferior [-copies <N>] [ID]
1995 Make a new inferior ready to execute the same program another
1996 inferior has loaded.
2001 maint info program-spaces
2002 List the program spaces loaded into GDB.
2004 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2005 show remote interrupt-sequence
2006 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2007 as the sequence to the remote target in order to interrupt the execution.
2008 Ctrl-C is a default. Some system prefers BREAK which is high level of
2009 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2010 Magic SysRq g. It is BREAK signal and character 'g'.
2012 set remote interrupt-on-connect [on | off]
2013 show remote interrupt-on-connect
2014 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2015 remote target when gdb connects to it. This is needed when you debug
2018 set remotebreak [on | off]
2020 Deprecated. Use "set/show remote interrupt-sequence" instead.
2022 tvariable $NAME [ = EXP ]
2023 Create or modify a trace state variable.
2026 List trace state variables and their values.
2028 delete tvariable $NAME ...
2029 Delete one or more trace state variables.
2032 Evaluate the given expressions without collecting anything into the
2033 trace buffer. (Valid in tracepoint actions only.)
2035 ftrace FN / FILE:LINE / *ADDR
2036 Define a fast tracepoint at the given function, line, or address.
2038 * New expression syntax
2040 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2041 GDB now parses 0b101010 identically with 42.
2045 set follow-exec-mode new|same
2046 show follow-exec-mode
2047 Control whether GDB reuses the same inferior across an exec call or
2048 creates a new one. This is useful to be able to restart the old
2049 executable after the inferior having done an exec call.
2051 set default-collect EXPR, ...
2052 show default-collect
2053 Define a list of expressions to be collected at each tracepoint.
2054 This is a useful way to ensure essential items are not overlooked,
2055 such as registers or a critical global variable.
2057 set disconnected-tracing
2058 show disconnected-tracing
2059 If set to 1, the target is instructed to continue tracing if it
2060 loses its connection to GDB. If 0, the target is to stop tracing
2063 set circular-trace-buffer
2064 show circular-trace-buffer
2065 If set to on, the target is instructed to use a circular trace buffer
2066 and discard the oldest trace frames instead of stopping the trace due
2067 to a full trace buffer. If set to off, the trace stops when the buffer
2068 fills up. Some targets may not support this.
2070 set script-extension off|soft|strict
2071 show script-extension
2072 If set to "off", the debugger does not perform any script language
2073 recognition, and all sourced files are assumed to be GDB scripts.
2074 If set to "soft" (the default), files are sourced according to
2075 filename extension, falling back to GDB scripts if the first
2077 If set to "strict", files are sourced according to filename extension.
2079 set ada trust-PAD-over-XVS on|off
2080 show ada trust-PAD-over-XVS
2081 If off, activate a workaround against a bug in the debugging information
2082 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2083 the GCC sources for more information about the GNAT encoding and
2084 PAD types in particular). It is always safe to set this option to
2085 off, but this introduces a slight performance penalty. The default
2088 * Python API Improvements
2090 ** GDB provides the new class gdb.LazyString. This is useful in
2091 some pretty-printing cases. The new method gdb.Value.lazy_string
2092 provides a simple way to create objects of this type.
2094 ** The fields returned by gdb.Type.fields now have an
2095 `is_base_class' attribute.
2097 ** The new method gdb.Type.range returns the range of an array type.
2099 ** The new method gdb.parse_and_eval can be used to parse and
2100 evaluate an expression.
2102 * New remote packets
2105 Define a trace state variable.
2108 Get the current value of a trace state variable.
2111 Set desired tracing behavior upon disconnection.
2114 Set the trace buffer to be linear or circular.
2117 Get data about the tracepoints currently in use.
2121 Process record now works correctly with hardware watchpoints.
2123 Multiple bug fixes have been made to the mips-irix port, making it
2124 much more reliable. In particular:
2125 - Debugging threaded applications is now possible again. Previously,
2126 GDB would hang while starting the program, or while waiting for
2127 the program to stop at a breakpoint.
2128 - Attaching to a running process no longer hangs.
2129 - An error occurring while loading a core file has been fixed.
2130 - Changing the value of the PC register now works again. This fixes
2131 problems observed when using the "jump" command, or when calling
2132 a function from GDB, or even when assigning a new value to $pc.
2133 - With the "finish" and "return" commands, the return value for functions
2134 returning a small array is now correctly printed.
2135 - It is now possible to break on shared library code which gets executed
2136 during a shared library init phase (code executed while executing
2137 their .init section). Previously, the breakpoint would have no effect.
2138 - GDB is now able to backtrace through the signal handler for
2139 non-threaded programs.
2141 PIE (Position Independent Executable) programs debugging is now supported.
2142 This includes debugging execution of PIC (Position Independent Code) shared
2143 libraries although for that, it should be possible to run such libraries as an
2146 *** Changes in GDB 7.0
2148 * GDB now has an interface for JIT compilation. Applications that
2149 dynamically generate code can create symbol files in memory and register
2150 them with GDB. For users, the feature should work transparently, and
2151 for JIT developers, the interface is documented in the GDB manual in the
2152 "JIT Compilation Interface" chapter.
2154 * Tracepoints may now be conditional. The syntax is as for
2155 breakpoints; either an "if" clause appended to the "trace" command,
2156 or the "condition" command is available. GDB sends the condition to
2157 the target for evaluation using the same bytecode format as is used
2158 for tracepoint actions.
2160 * The disassemble command now supports: an optional /r modifier, print the
2161 raw instructions in hex as well as in symbolic form, and an optional /m
2162 modifier to print mixed source+assembly.
2164 * Process record and replay
2166 In a architecture environment that supports ``process record and
2167 replay'', ``process record and replay'' target can record a log of
2168 the process execution, and replay it with both forward and reverse
2171 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2172 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2173 set execution-direction {forward|reverse}, for targets that support
2176 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2177 feature is available with a native GDB running on kernel version
2180 * GDB now has support for multi-byte and wide character sets on the
2181 target. Strings whose character type is wchar_t, char16_t, or
2182 char32_t are now correctly printed. GDB supports wide- and unicode-
2183 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2184 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2185 `printf'. This feature requires iconv to work properly; if your
2186 system does not have a working iconv, GDB can use GNU libiconv. See
2187 the installation instructions for more information.
2189 * GDB now supports automatic retrieval of shared library files from
2190 remote targets. To use this feature, specify a system root that begins
2191 with the `remote:' prefix, either via the `set sysroot' command or via
2192 the `--with-sysroot' configure-time option.
2194 * "info sharedlibrary" now takes an optional regex of libraries to show,
2195 and it now reports if a shared library has no debugging information.
2197 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2198 now complete on file names.
2200 * When completing in expressions, gdb will attempt to limit
2201 completions to allowable structure or union fields, where appropriate.
2202 For instance, consider:
2204 # struct example { int f1; double f2; };
2205 # struct example variable;
2208 If the user types TAB at the end of this command line, the available
2209 completions will be "f1" and "f2".
2211 * Inlined functions are now supported. They show up in backtraces, and
2212 the "step", "next", and "finish" commands handle them automatically.
2214 * GDB now supports the token-splicing (##) and stringification (#)
2215 operators when expanding macros. It also supports variable-arity
2218 * GDB now supports inspecting extra signal information, exported by
2219 the new $_siginfo convenience variable. The feature is currently
2220 implemented on linux ARM, i386 and amd64.
2222 * GDB can now display the VFP floating point registers and NEON vector
2223 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2224 can provide these registers (requires Linux 2.6.30 or later). Remote
2225 and simulator targets may also provide them.
2227 * New remote packets
2230 Search memory for a sequence of bytes.
2233 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2234 operation over reliable transport links. Use of this packet is
2235 controlled by the `set remote noack-packet' command.
2238 Kill the process with the specified process ID. Use this in preference
2239 to `k' when multiprocess protocol extensions are supported.
2242 Obtains additional operating system information
2246 Read or write additional signal information.
2248 * Removed remote protocol undocumented extension
2250 An undocumented extension to the remote protocol's `S' stop reply
2251 packet that permited the stub to pass a process id was removed.
2252 Remote servers should use the `T' stop reply packet instead.
2254 * GDB now supports multiple function calling conventions according to the
2255 DWARF-2 DW_AT_calling_convention function attribute.
2257 * The SH target utilizes the aforementioned change to distinguish between gcc
2258 and Renesas calling convention. It also adds the new CLI commands
2259 `set/show sh calling-convention'.
2261 * GDB can now read compressed debug sections, as produced by GNU gold
2262 with the --compress-debug-sections=zlib flag.
2264 * 64-bit core files are now supported on AIX.
2266 * Thread switching is now supported on Tru64.
2268 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2269 which will be allocated using malloc later in program execution.
2271 * The qXfer:libraries:read remote procotol packet now allows passing a
2272 list of section offsets.
2274 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2275 conditions handling signals delivered during attach or thread creation
2276 have also been fixed.
2278 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2279 From the user's standpoint, all unqualified instances of True and False
2280 are treated as the standard definitions, regardless of context.
2282 * GDB now parses C++ symbol and type names more flexibly. For
2285 template<typename T> class C { };
2288 GDB will now correctly handle all of:
2290 ptype C<char const *>
2291 ptype C<char const*>
2292 ptype C<const char *>
2293 ptype C<const char*>
2295 * New features in the GDB remote stub, gdbserver
2297 - The "--wrapper" command-line argument tells gdbserver to use a
2298 wrapper program to launch programs for debugging.
2300 - On PowerPC and S/390 targets, it is now possible to use a single
2301 gdbserver executable to debug both 32-bit and 64-bit programs.
2302 (This requires gdbserver itself to be built as a 64-bit executable.)
2304 - gdbserver uses the new noack protocol mode for TCP connections to
2305 reduce communications latency, if also supported and enabled in GDB.
2307 - Support for the sparc64-linux-gnu target is now included in
2310 - The amd64-linux build of gdbserver now supports debugging both
2311 32-bit and 64-bit programs.
2313 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2314 now support hardware watchpoints, and will use them automatically
2319 GDB now has support for scripting using Python. Whether this is
2320 available is determined at configure time.
2322 New GDB commands can now be written in Python.
2324 * Ada tasking support
2326 Ada tasks can now be inspected in GDB. The following commands have
2330 Print the list of Ada tasks.
2332 Print detailed information about task number N.
2334 Print the task number of the current task.
2336 Switch the context of debugging to task number N.
2338 * Support for user-defined prefixed commands. The "define" command can
2339 add new commands to existing prefixes, e.g. "target".
2341 * Multi-inferior, multi-process debugging.
2343 GDB now has generalized support for multi-inferior debugging. See
2344 "Debugging Multiple Inferiors" in the manual for more information.
2345 Although availability still depends on target support, the command
2346 set is more uniform now. The GNU/Linux specific multi-forks support
2347 has been migrated to this new framework. This implied some user
2348 visible changes; see "New commands" and also "Removed commands"
2351 * Target descriptions can now describe the target OS ABI. See the
2352 "Target Description Format" section in the user manual for more
2355 * Target descriptions can now describe "compatible" architectures
2356 to indicate that the target can execute applications for a different
2357 architecture in addition to those for the main target architecture.
2358 See the "Target Description Format" section in the user manual for
2361 * Multi-architecture debugging.
2363 GDB now includes general supports for debugging applications on
2364 hybrid systems that use more than one single processor architecture
2365 at the same time. Each such hybrid architecture still requires
2366 specific support to be added. The only hybrid architecture supported
2367 in this version of GDB is the Cell Broadband Engine.
2369 * GDB now supports integrated debugging of Cell/B.E. applications that
2370 use both the PPU and SPU architectures. To enable support for hybrid
2371 Cell/B.E. debugging, you need to configure GDB to support both the
2372 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2373 --enable-targets configure option.
2375 * Non-stop mode debugging.
2377 For some targets, GDB now supports an optional mode of operation in
2378 which you can examine stopped threads while other threads continue
2379 to execute freely. This is referred to as non-stop mode, with the
2380 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2381 section in the user manual for more information.
2383 To be able to support remote non-stop debugging, a remote stub needs
2384 to implement the non-stop mode remote protocol extensions, as
2385 described in the "Remote Non-Stop" section of the user manual. The
2386 GDB remote stub, gdbserver, has been adjusted to support these
2387 extensions on linux targets.
2389 * New commands (for set/show, see "New options" below)
2391 catch syscall [NAME(S) | NUMBER(S)]
2392 Catch system calls. Arguments, which should be names of system
2393 calls or their numbers, mean catch only those syscalls. Without
2394 arguments, every syscall will be caught. When the inferior issues
2395 any of the specified syscalls, GDB will stop and announce the system
2396 call, both when it is called and when its call returns. This
2397 feature is currently available with a native GDB running on the
2398 Linux Kernel, under the following architectures: x86, x86_64,
2399 PowerPC and PowerPC64.
2401 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2403 Search memory for a sequence of bytes.
2405 maint set python print-stack
2406 maint show python print-stack
2407 Show a stack trace when an error is encountered in a Python script.
2410 Invoke CODE by passing it to the Python interpreter.
2415 These allow macros to be defined, undefined, and listed
2419 Show operating system information about processes.
2422 List the inferiors currently under GDB's control.
2425 Switch focus to inferior number NUM.
2428 Detach from inferior number NUM.
2431 Kill inferior number NUM.
2435 set spu stop-on-load
2436 show spu stop-on-load
2437 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2439 set spu auto-flush-cache
2440 show spu auto-flush-cache
2441 Control whether to automatically flush the software-managed cache
2442 during Cell/B.E. debugging.
2444 set sh calling-convention
2445 show sh calling-convention
2446 Control the calling convention used when calling SH target functions.
2449 show debug timestamp
2450 Control display of timestamps with GDB debugging output.
2452 set disassemble-next-line
2453 show disassemble-next-line
2454 Control display of disassembled source lines or instructions when
2457 set remote noack-packet
2458 show remote noack-packet
2459 Set/show the use of remote protocol QStartNoAckMode packet. See above
2460 under "New remote packets."
2462 set remote query-attached-packet
2463 show remote query-attached-packet
2464 Control use of remote protocol `qAttached' (query-attached) packet.
2466 set remote read-siginfo-object
2467 show remote read-siginfo-object
2468 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2471 set remote write-siginfo-object
2472 show remote write-siginfo-object
2473 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2476 set remote reverse-continue
2477 show remote reverse-continue
2478 Control use of remote protocol 'bc' (reverse-continue) packet.
2480 set remote reverse-step
2481 show remote reverse-step
2482 Control use of remote protocol 'bs' (reverse-step) packet.
2484 set displaced-stepping
2485 show displaced-stepping
2486 Control displaced stepping mode. Displaced stepping is a way to
2487 single-step over breakpoints without removing them from the debuggee.
2488 Also known as "out-of-line single-stepping".
2491 show debug displaced
2492 Control display of debugging info for displaced stepping.
2494 maint set internal-error
2495 maint show internal-error
2496 Control what GDB does when an internal error is detected.
2498 maint set internal-warning
2499 maint show internal-warning
2500 Control what GDB does when an internal warning is detected.
2505 Use a wrapper program to launch programs for debugging.
2507 set multiple-symbols (all|ask|cancel)
2508 show multiple-symbols
2509 The value of this variable can be changed to adjust the debugger behavior
2510 when an expression or a breakpoint location contains an ambiguous symbol
2511 name (an overloaded function name, for instance).
2513 set breakpoint always-inserted
2514 show breakpoint always-inserted
2515 Keep breakpoints always inserted in the target, as opposed to inserting
2516 them when resuming the target, and removing them when the target stops.
2517 This option can improve debugger performance on slow remote targets.
2519 set arm fallback-mode (arm|thumb|auto)
2520 show arm fallback-mode
2521 set arm force-mode (arm|thumb|auto)
2523 These commands control how ARM GDB determines whether instructions
2524 are ARM or Thumb. The default for both settings is auto, which uses
2525 the current CPSR value for instructions without symbols; previous
2526 versions of GDB behaved as if "set arm fallback-mode arm".
2528 set disable-randomization
2529 show disable-randomization
2530 Standalone programs run with the virtual address space randomization enabled
2531 by default on some platforms. This option keeps the addresses stable across
2532 multiple debugging sessions.
2536 Control whether other threads are stopped or not when some thread hits
2541 Requests that asynchronous execution is enabled in the target, if available.
2542 In this case, it's possible to resume target in the background, and interact
2543 with GDB while the target is running. "show target-async" displays the
2544 current state of asynchronous execution of the target.
2546 set target-wide-charset
2547 show target-wide-charset
2548 The target-wide-charset is the name of the character set that GDB
2549 uses when printing characters whose type is wchar_t.
2551 set tcp auto-retry (on|off)
2553 set tcp connect-timeout
2554 show tcp connect-timeout
2555 These commands allow GDB to retry failed TCP connections to a remote stub
2556 with a specified timeout period; this is useful if the stub is launched
2557 in parallel with GDB but may not be ready to accept connections immediately.
2559 set libthread-db-search-path
2560 show libthread-db-search-path
2561 Control list of directories which GDB will search for appropriate
2564 set schedule-multiple (on|off)
2565 show schedule-multiple
2566 Allow GDB to resume all threads of all processes or only threads of
2567 the current process.
2571 Use more aggressive caching for accesses to the stack. This improves
2572 performance of remote debugging (particularly backtraces) without
2573 affecting correctness.
2575 set interactive-mode (on|off|auto)
2576 show interactive-mode
2577 Control whether GDB runs in interactive mode (on) or not (off).
2578 When in interactive mode, GDB waits for the user to answer all
2579 queries. Otherwise, GDB does not wait and assumes the default
2580 answer. When set to auto (the default), GDB determines which
2581 mode to use based on the stdin settings.
2586 For program forks, this is replaced by the new more generic `info
2587 inferiors' command. To list checkpoints, you can still use the
2588 `info checkpoints' command, which was an alias for the `info forks'
2592 Replaced by the new `inferior' command. To switch between
2593 checkpoints, you can still use the `restart' command, which was an
2594 alias for the `fork' command.
2597 This is removed, since some targets don't have a notion of
2598 processes. To switch between processes, you can still use the
2599 `inferior' command using GDB's own inferior number.
2602 For program forks, this is replaced by the new more generic `kill
2603 inferior' command. To delete a checkpoint, you can still use the
2604 `delete checkpoint' command, which was an alias for the `delete
2608 For program forks, this is replaced by the new more generic `detach
2609 inferior' command. To detach a checkpoint, you can still use the
2610 `detach checkpoint' command, which was an alias for the `detach
2613 * New native configurations
2615 x86/x86_64 Darwin i[34567]86-*-darwin*
2617 x86_64 MinGW x86_64-*-mingw*
2621 Lattice Mico32 lm32-*
2622 x86 DICOS i[34567]86-*-dicos*
2623 x86_64 DICOS x86_64-*-dicos*
2626 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2627 (mingw32ce) debugging.
2633 These commands were actually not implemented on any target.
2635 *** Changes in GDB 6.8
2637 * New native configurations
2639 NetBSD/hppa hppa*-*netbsd*
2640 Xtensa GNU/Linux xtensa*-*-linux*
2644 NetBSD/hppa hppa*-*-netbsd*
2645 Xtensa GNU/Lunux xtensa*-*-linux*
2647 * Change in command line behavior -- corefiles vs. process ids.
2649 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2650 attaching to process NUMBER fails, GDB no longer attempts to open a
2651 core file named NUMBER. Attaching to a program using the -c option
2652 is no longer supported. Instead, use the '-p' or '--pid' options.
2654 * GDB can now be built as a native debugger for debugging Windows x86
2655 (mingw32) Portable Executable (PE) programs.
2657 * Pending breakpoints no longer change their number when their address
2660 * GDB now supports breakpoints with multiple locations,
2661 including breakpoints on C++ constructors, inside C++ templates,
2662 and in inlined functions.
2664 * GDB's ability to debug optimized code has been improved. GDB more
2665 accurately identifies function bodies and lexical blocks that occupy
2666 more than one contiguous range of addresses.
2668 * Target descriptions can now describe registers for PowerPC.
2670 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2671 registers on PowerPC targets.
2673 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2674 targets even when the libthread_db library is not available.
2676 * The GDB remote stub, gdbserver, now supports the new file transfer
2677 commands (remote put, remote get, and remote delete).
2679 * The GDB remote stub, gdbserver, now supports run and attach in
2680 extended-remote mode.
2682 * hppa*64*-*-hpux11* target broken
2683 The debugger is unable to start a program and fails with the following
2684 error: "Error trying to get information about dynamic linker".
2685 The gdb-6.7 release is also affected.
2687 * GDB now supports the --enable-targets= configure option to allow
2688 building a single GDB executable that supports multiple remote
2689 target architectures.
2691 * GDB now supports debugging C and C++ programs which use the
2692 Decimal Floating Point extension. In addition, the PowerPC target
2693 now has a set of pseudo-registers to inspect decimal float values
2694 stored in two consecutive float registers.
2696 * The -break-insert MI command can optionally create pending
2699 * Improved support for debugging Ada
2700 Many improvements to the Ada language support have been made. These
2702 - Better support for Ada2005 interface types
2703 - Improved handling of arrays and slices in general
2704 - Better support for Taft-amendment types
2705 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2707 - Improved command completion in Ada
2710 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2715 set print frame-arguments (all|scalars|none)
2716 show print frame-arguments
2717 The value of this variable can be changed to control which argument
2718 values should be printed by the debugger when displaying a frame.
2723 Transfer files to and from a remote target, and delete remote files.
2730 Transfer files to and from a remote target, and delete remote files.
2732 * New remote packets
2739 Open, close, read, write, and delete files on the remote system.
2742 Attach to an existing process on the remote system, in extended-remote
2746 Run a new process on the remote system, in extended-remote mode.
2748 *** Changes in GDB 6.7
2750 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2751 bfd, libiberty and opcodes, as revealed by static analysis donated by
2752 Coverity, Inc. (http://scan.coverity.com).
2754 * When looking up multiply-defined global symbols, GDB will now prefer the
2755 symbol definition in the current shared library if it was built using the
2756 -Bsymbolic linker option.
2758 * When the Text User Interface (TUI) is not configured, GDB will now
2759 recognize the -tui command-line option and print a message that the TUI
2762 * The GDB remote stub, gdbserver, now has lower overhead for high
2763 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2765 * GDB for MIPS targets now autodetects whether a remote target provides
2766 32-bit or 64-bit register values.
2768 * Support for C++ member pointers has been improved.
2770 * GDB now understands XML target descriptions, which specify the
2771 target's overall architecture. GDB can read a description from
2772 a local file or over the remote serial protocol.
2774 * Vectors of single-byte data use a new integer type which is not
2775 automatically displayed as character or string data.
2777 * The /s format now works with the print command. It displays
2778 arrays of single-byte integers and pointers to single-byte integers
2781 * Target descriptions can now describe target-specific registers,
2782 for architectures which have implemented the support (currently
2783 only ARM, M68K, and MIPS).
2785 * GDB and the GDB remote stub, gdbserver, now support the XScale
2788 * The GDB remote stub, gdbserver, has been updated to support
2789 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2790 has been rewritten to use the standard GDB remote protocol.
2792 * GDB can now step into C++ functions which are called through thunks.
2794 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2796 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2797 layout. It also supports a TextSeg= and DataSeg= response when only
2798 segment base addresses (rather than offsets) are available.
2800 * The /i format now outputs any trailing branch delay slot instructions
2801 immediately following the last instruction within the count specified.
2803 * The GDB remote protocol "T" stop reply packet now supports a
2804 "library" response. Combined with the new "qXfer:libraries:read"
2805 packet, this response allows GDB to debug shared libraries on targets
2806 where the operating system manages the list of loaded libraries (e.g.
2807 Windows and SymbianOS).
2809 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2810 (DLLs) on Windows and Windows CE targets.
2812 * GDB now supports a faster verification that a .debug file matches its binary
2813 according to its build-id signature, if the signature is present.
2819 Enable or disable hardware flow control (RTS/CTS) on the serial port
2820 when debugging using remote targets.
2822 set mem inaccessible-by-default
2823 show mem inaccessible-by-default
2824 If the target supplies a memory map, for instance via the remote
2825 protocol's "qXfer:memory-map:read" packet, setting this variable
2826 prevents GDB from accessing memory outside the memory map. This
2827 is useful for targets with memory mapped registers or which react
2828 badly to accesses of unmapped address space.
2830 set breakpoint auto-hw
2831 show breakpoint auto-hw
2832 If the target supplies a memory map, for instance via the remote
2833 protocol's "qXfer:memory-map:read" packet, setting this variable
2834 lets GDB use hardware breakpoints automatically for memory regions
2835 where it can not use software breakpoints. This covers both the
2836 "break" command and internal breakpoints used for other commands
2837 including "next" and "finish".
2840 catch exception unhandled
2841 Stop the program execution when Ada exceptions are raised.
2844 Stop the program execution when an Ada assertion failed.
2848 Set an alternate system root for target files. This is a more
2849 general version of "set solib-absolute-prefix", which is now
2850 an alias to "set sysroot".
2853 Provide extended SPU facility status information. This set of
2854 commands is available only when debugging the Cell/B.E. SPU
2857 * New native configurations
2859 OpenBSD/sh sh*-*openbsd*
2862 unset tdesc filename
2864 Use the specified local file as an XML target description, and do
2865 not query the target for its built-in description.
2869 OpenBSD/sh sh*-*-openbsd*
2870 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2871 Toshiba Media Processor mep-elf
2873 * New remote packets
2876 Ignore the specified signals; pass them directly to the debugged program
2877 without stopping other threads or reporting them to GDB.
2879 qXfer:features:read:
2880 Read an XML target description from the target, which describes its
2885 Read or write contents of an spufs file on the target system. These
2886 packets are available only on the Cell/B.E. SPU architecture.
2888 qXfer:libraries:read:
2889 Report the loaded shared libraries. Combined with new "T" packet
2890 response, this packet allows GDB to debug shared libraries on
2891 targets where the operating system manages the list of loaded
2892 libraries (e.g. Windows and SymbianOS).
2896 Support for these obsolete configurations has been removed.
2904 i[34567]86-*-lynxos*
2905 i[34567]86-*-netware*
2906 i[34567]86-*-sco3.2v5*
2907 i[34567]86-*-sco3.2v4*
2909 i[34567]86-*-sysv4.2*
2912 i[34567]86-*-unixware2*
2913 i[34567]86-*-unixware*
2922 * Other removed features
2929 Various m68k-only ROM monitors.
2936 Various Renesas ROM monitors and debugging interfaces for SH and
2941 Support for a Macraigor serial interface to on-chip debugging.
2942 GDB does not directly support the newer parallel or USB
2947 A debug information format. The predecessor to DWARF 2 and
2948 DWARF 3, which are still supported.
2950 Support for the HP aCC compiler on HP-UX/PA-RISC
2952 SOM-encapsulated symbolic debugging information, automatic
2953 invocation of pxdb, and the aCC custom C++ ABI. This does not
2954 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2955 with aCC can still be debugged on an assembly level.
2957 MIPS ".pdr" sections
2959 A MIPS-specific format used to describe stack frame layout
2960 in debugging information.
2964 GDB could work with an older version of Guile to debug
2965 the interpreter and Scheme programs running in it.
2967 set mips stack-arg-size
2968 set mips saved-gpreg-size
2970 Use "set mips abi" to control parameter passing for MIPS.
2972 *** Changes in GDB 6.6
2977 Cell Broadband Engine SPU spu-elf
2979 * GDB can now be configured as a cross-debugger targeting native Windows
2980 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2981 running on a Windows system over TCP/IP to debug Windows programs.
2983 * The GDB remote stub, gdbserver, has been updated to support Windows and
2984 Cygwin debugging. Both single-threaded and multi-threaded programs are
2987 * The "set trust-readonly-sections" command works again. This command was
2988 broken in GDB 6.3, 6.4, and 6.5.
2990 * The "load" command now supports writing to flash memory, if the remote
2991 stub provides the required support.
2993 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2994 longer requires symbolic debug information (e.g. DWARF-2).
2999 unset substitute-path
3000 show substitute-path
3001 Manage a list of substitution rules that GDB uses to rewrite the name
3002 of the directories where the sources are located. This can be useful
3003 for instance when the sources were moved to a different location
3004 between compilation and debugging.
3008 Print each CLI command as it is executed. Each command is prefixed with
3009 a number of `+' symbols representing the nesting depth.
3010 The source command now has a `-v' option to enable the same feature.
3014 The ARM Demon monitor support (RDP protocol, "target rdp").
3016 Kernel Object Display, an embedded debugging feature which only worked with
3017 an obsolete version of Cisco IOS.
3019 The 'set download-write-size' and 'show download-write-size' commands.
3021 * New remote packets
3024 Tell a stub about GDB client features, and request remote target features.
3025 The first feature implemented is PacketSize, which allows the target to
3026 specify the size of packets it can handle - to minimize the number of
3027 packets required and improve performance when connected to a remote
3031 Fetch an OS auxilliary vector from the remote stub. This packet is a
3032 more efficient replacement for qPart:auxv:read.
3034 qXfer:memory-map:read:
3035 Fetch a memory map from the remote stub, including information about
3036 RAM, ROM, and flash memory devices.
3041 Erase and program a flash memory device.
3043 * Removed remote packets
3046 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3047 used it, and only gdbserver implemented it.
3049 *** Changes in GDB 6.5
3053 Renesas M32C/M16C m32c-elf
3055 Morpho Technologies ms1 ms1-elf
3059 init-if-undefined Initialize a convenience variable, but
3060 only if it doesn't already have a value.
3062 The following commands are presently only implemented for native GNU/Linux:
3064 checkpoint Save a snapshot of the program state.
3066 restart <n> Return the program state to a
3067 previously saved state.
3069 info checkpoints List currently saved checkpoints.
3071 delete-checkpoint <n> Delete a previously saved checkpoint.
3073 set|show detach-on-fork Tell gdb whether to detach from a newly
3074 forked process, or to keep debugging it.
3076 info forks List forks of the user program that
3077 are available to be debugged.
3079 fork <n> Switch to debugging one of several
3080 forks of the user program that are
3081 available to be debugged.
3083 delete-fork <n> Delete a fork from the list of forks
3084 that are available to be debugged (and
3085 kill the forked process).
3087 detach-fork <n> Delete a fork from the list of forks
3088 that are available to be debugged (and
3089 allow the process to continue).
3093 Morpho Technologies ms2 ms1-elf
3095 * Improved Windows host support
3097 GDB now builds as a cross debugger hosted on i686-mingw32, including
3098 native console support, and remote communications using either
3099 network sockets or serial ports.
3101 * Improved Modula-2 language support
3103 GDB can now print most types in the Modula-2 syntax. This includes:
3104 basic types, set types, record types, enumerated types, range types,
3105 pointer types and ARRAY types. Procedure var parameters are correctly
3106 printed and hexadecimal addresses and character constants are also
3107 written in the Modula-2 syntax. Best results can be obtained by using
3108 GNU Modula-2 together with the -gdwarf-2 command line option.
3112 The ARM rdi-share module.
3114 The Netware NLM debug server.
3116 *** Changes in GDB 6.4
3118 * New native configurations
3120 OpenBSD/arm arm*-*-openbsd*
3121 OpenBSD/mips64 mips64-*-openbsd*
3125 Morpho Technologies ms1 ms1-elf
3127 * New command line options
3129 --batch-silent As for --batch, but totally silent.
3130 --return-child-result The debugger will exist with the same value
3131 the child (debugged) program exited with.
3132 --eval-command COMMAND, -ex COMMAND
3133 Execute a single GDB CLI command. This may be
3134 specified multiple times and in conjunction
3135 with the --command (-x) option.
3137 * Deprecated commands removed
3139 The following commands, that were deprecated in 2000, have been
3143 set|show arm disassembly-flavor set|show arm disassembler
3144 othernames set arm disassembler
3145 set|show remotedebug set|show debug remote
3146 set|show archdebug set|show debug arch
3147 set|show eventdebug set|show debug event
3150 * New BSD user-level threads support
3152 It is now possible to debug programs using the user-level threads
3153 library on OpenBSD and FreeBSD. Currently supported (target)
3156 FreeBSD/amd64 x86_64-*-freebsd*
3157 FreeBSD/i386 i386-*-freebsd*
3158 OpenBSD/i386 i386-*-openbsd*
3160 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3161 are not yet supported.
3163 * New support for Matsushita MN10300 w/sim added
3164 (Work in progress). mn10300-elf.
3166 * REMOVED configurations and files
3168 VxWorks and the XDR protocol *-*-vxworks
3169 Motorola MCORE mcore-*-*
3170 National Semiconductor NS32000 ns32k-*-*
3172 * New "set print array-indexes" command
3174 After turning this setting "on", GDB prints the index of each element
3175 when displaying arrays. The default is "off" to preserve the previous
3178 * VAX floating point support
3180 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3182 * User-defined command support
3184 In addition to using $arg0..$arg9 for argument passing, it is now possible
3185 to use $argc to determine now many arguments have been passed. See the
3186 section on user-defined commands in the user manual for more information.
3188 *** Changes in GDB 6.3:
3190 * New command line option
3192 GDB now accepts -l followed by a number to set the timeout for remote
3195 * GDB works with GCC -feliminate-dwarf2-dups
3197 GDB now supports a more compact representation of DWARF-2 debug
3198 information using DW_FORM_ref_addr references. These are produced
3199 by GCC with the option -feliminate-dwarf2-dups and also by some
3200 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3201 to use -feliminate-dwarf2-dups.
3203 * Internationalization
3205 When supported by the host system, GDB will be built with
3206 internationalization (libintl). The task of marking up the sources is
3207 continued, we're looking forward to our first translation.
3211 Initial support for debugging programs compiled with the GNAT
3212 implementation of the Ada programming language has been integrated
3213 into GDB. In this release, support is limited to expression evaluation.
3215 * New native configurations
3217 GNU/Linux/m32r m32r-*-linux-gnu
3221 GDB's remote protocol now includes support for the 'p' packet. This
3222 packet is used to fetch individual registers from a remote inferior.
3224 * END-OF-LIFE registers[] compatibility module
3226 GDB's internal register infrastructure has been completely rewritten.
3227 The new infrastructure making possible the implementation of key new
3228 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3231 GDB 6.3 will be the last release to include the the registers[]
3232 compatibility module that allowed out-of-date configurations to
3233 continue to work. This change directly impacts the following
3243 powerpc bdm protocol
3245 Unless there is activity to revive these configurations, they will be
3246 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3248 * OBSOLETE configurations and files
3250 Configurations that have been declared obsolete in this release have
3251 been commented out. Unless there is activity to revive these
3252 configurations, the next release of GDB will have their sources
3253 permanently REMOVED.
3262 *** Changes in GDB 6.2.1:
3264 * MIPS `break main; run' gave an heuristic-fence-post warning
3266 When attempting to run even a simple program, a warning about
3267 heuristic-fence-post being hit would be reported. This problem has
3270 * MIPS IRIX 'long double' crashed GDB
3272 When examining a long double variable, GDB would get a segmentation
3273 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3274 IRIX long double values).
3278 A bug in the VAX stack code was causing problems with the "next"
3279 command. This problem has been fixed.
3281 *** Changes in GDB 6.2:
3283 * Fix for ``many threads''
3285 On GNU/Linux systems that use the NPTL threads library, a program
3286 rapidly creating and deleting threads would confuse GDB leading to the
3289 ptrace: No such process.
3290 thread_db_get_info: cannot get thread info: generic error
3292 This problem has been fixed.
3294 * "-async" and "-noasync" options removed.
3296 Support for the broken "-noasync" option has been removed (it caused
3299 * New ``start'' command.
3301 This command runs the program until the begining of the main procedure.
3303 * New BSD Kernel Data Access Library (libkvm) interface
3305 Using ``target kvm'' it is now possible to debug kernel core dumps and
3306 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3307 platforms. Currently supported (native-only) configurations are:
3309 FreeBSD/amd64 x86_64-*-freebsd*
3310 FreeBSD/i386 i?86-*-freebsd*
3311 NetBSD/i386 i?86-*-netbsd*
3312 NetBSD/m68k m68*-*-netbsd*
3313 NetBSD/sparc sparc-*-netbsd*
3314 OpenBSD/amd64 x86_64-*-openbsd*
3315 OpenBSD/i386 i?86-*-openbsd*
3316 OpenBSD/m68k m68*-openbsd*
3317 OpenBSD/sparc sparc-*-openbsd*
3319 * Signal trampoline code overhauled
3321 Many generic problems with GDB's signal handling code have been fixed.
3322 These include: backtraces through non-contiguous stacks; recognition
3323 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3324 call; backtrace through a signal trampoline; step into and out of
3325 signal handlers; and single-stepping in the signal trampoline.
3327 Please note that kernel bugs are a limiting factor here. These
3328 features have been shown to work on an s390 GNU/Linux system that
3329 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3331 * Cygwin support for DWARF 2 added.
3333 * New native configurations
3335 GNU/Linux/hppa hppa*-*-linux*
3336 OpenBSD/hppa hppa*-*-openbsd*
3337 OpenBSD/m68k m68*-*-openbsd*
3338 OpenBSD/m88k m88*-*-openbsd*
3339 OpenBSD/powerpc powerpc-*-openbsd*
3340 NetBSD/vax vax-*-netbsd*
3341 OpenBSD/vax vax-*-openbsd*
3343 * END-OF-LIFE frame compatibility module
3345 GDB's internal frame infrastructure has been completely rewritten.
3346 The new infrastructure making it possible to support key new features
3347 including DWARF 2 Call Frame Information. To aid in the task of
3348 migrating old configurations to this new infrastructure, a
3349 compatibility module, that allowed old configurations to continue to
3350 work, was also included.
3352 GDB 6.2 will be the last release to include this frame compatibility
3353 module. This change directly impacts the following configurations:
3363 Unless there is activity to revive these configurations, they will be
3364 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3366 * REMOVED configurations and files
3368 Sun 3, running SunOS 3 m68*-*-sunos3*
3369 Sun 3, running SunOS 4 m68*-*-sunos4*
3370 Sun 2, running SunOS 3 m68000-*-sunos3*
3371 Sun 2, running SunOS 4 m68000-*-sunos4*
3372 Motorola 680x0 running LynxOS m68*-*-lynxos*
3373 AT&T 3b1/Unix pc m68*-att-*
3374 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3375 decstation mips-dec-* mips-little-*
3376 riscos mips-*-riscos* mips-*-sysv*
3377 sonymips mips-sony-*
3378 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3380 *** Changes in GDB 6.1.1:
3382 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3384 The TUI (Text-mode User Interface) is now built as part of a default
3385 GDB configuration. It is enabled by either selecting the TUI with the
3386 command line option "-i=tui" or by running the separate "gdbtui"
3387 program. For more information on the TUI, see the manual "Debugging
3390 * Pending breakpoint support (also included in GDB 6.1)
3392 Support has been added to allow you to specify breakpoints in shared
3393 libraries that have not yet been loaded. If a breakpoint location
3394 cannot be found, and the "breakpoint pending" option is set to auto,
3395 GDB queries you if you wish to make the breakpoint pending on a future
3396 shared-library load. If and when GDB resolves the breakpoint symbol,
3397 the pending breakpoint is removed as one or more regular breakpoints
3400 Pending breakpoints are very useful for GCJ Java debugging.
3402 * Fixed ISO-C build problems
3404 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3405 non ISO-C code that stopped them being built using a more strict ISO-C
3406 compiler (e.g., IBM's C compiler).
3408 * Fixed build problem on IRIX 5
3410 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3411 wasn't able to compile compile on an IRIX 5 system.
3413 * Added execute permission to gdb/gdbserver/configure
3415 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3416 permission. This bug would cause configure to fail on a number of
3417 systems (Solaris, IRIX). Ref: server/519.
3419 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3421 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3422 has been updated to use constant array sizes.
3424 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3426 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3427 its generated DWARF Call Frame Info. This encoding was causing GDB to
3428 panic, that panic has been fixed. Ref: gdb/1628.
3430 * Fixed a problem when examining parameters in shared library code.
3432 When examining parameters in optimized shared library code generated
3433 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3434 not available''. GDB now correctly displays the variable's value.
3436 *** Changes in GDB 6.1:
3438 * Removed --with-mmalloc
3440 Support for the mmalloc memory manager has been removed, as it
3441 conflicted with the internal gdb byte cache.
3443 * Changes in AMD64 configurations
3445 The AMD64 target now includes the %cs and %ss registers. As a result
3446 the AMD64 remote protocol has changed; this affects the floating-point
3447 and SSE registers. If you rely on those registers for your debugging,
3448 you should upgrade gdbserver on the remote side.
3450 * Revised SPARC target
3452 The SPARC target has been completely revised, incorporating the
3453 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3454 support for LynxOS and SunOS 4 has been dropped. Calling functions
3455 from within GDB on operating systems with a non-executable stack
3456 (Solaris, OpenBSD) now works.
3460 GDB has a new C++ demangler which does a better job on the mangled
3461 names generated by current versions of g++. It also runs faster, so
3462 with this and other changes gdb should now start faster on large C++
3465 * DWARF 2 Location Expressions
3467 GDB support for location expressions has been extended to support function
3468 arguments and frame bases. Older versions of GDB could crash when they
3471 * C++ nested types and namespaces
3473 GDB's support for nested types and namespaces in C++ has been
3474 improved, especially if you use the DWARF 2 debugging format. (This
3475 is the default for recent versions of GCC on most platforms.)
3476 Specifically, if you have a class "Inner" defined within a class or
3477 namespace "Outer", then GDB realizes that the class's name is
3478 "Outer::Inner", not simply "Inner". This should greatly reduce the
3479 frequency of complaints about not finding RTTI symbols. In addition,
3480 if you are stopped at inside of a function defined within a namespace,
3481 GDB modifies its name lookup accordingly.
3483 * New native configurations
3485 NetBSD/amd64 x86_64-*-netbsd*
3486 OpenBSD/amd64 x86_64-*-openbsd*
3487 OpenBSD/alpha alpha*-*-openbsd*
3488 OpenBSD/sparc sparc-*-openbsd*
3489 OpenBSD/sparc64 sparc64-*-openbsd*
3491 * New debugging protocols
3493 M32R with SDI protocol m32r-*-elf*
3495 * "set prompt-escape-char" command deleted.
3497 The command "set prompt-escape-char" has been deleted. This command,
3498 and its very obscure effet on GDB's prompt, was never documented,
3499 tested, nor mentioned in the NEWS file.
3501 * OBSOLETE configurations and files
3503 Configurations that have been declared obsolete in this release have
3504 been commented out. Unless there is activity to revive these
3505 configurations, the next release of GDB will have their sources
3506 permanently REMOVED.
3508 Sun 3, running SunOS 3 m68*-*-sunos3*
3509 Sun 3, running SunOS 4 m68*-*-sunos4*
3510 Sun 2, running SunOS 3 m68000-*-sunos3*
3511 Sun 2, running SunOS 4 m68000-*-sunos4*
3512 Motorola 680x0 running LynxOS m68*-*-lynxos*
3513 AT&T 3b1/Unix pc m68*-att-*
3514 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3515 decstation mips-dec-* mips-little-*
3516 riscos mips-*-riscos* mips-*-sysv*
3517 sonymips mips-sony-*
3518 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3520 * REMOVED configurations and files
3522 SGI Irix-4.x mips-sgi-irix4 or iris4
3523 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3524 Z8000 simulator z8k-zilog-none or z8ksim
3525 Matsushita MN10200 w/simulator mn10200-*-*
3526 H8/500 simulator h8500-hitachi-hms or h8500hms
3527 HP/PA running BSD hppa*-*-bsd*
3528 HP/PA running OSF/1 hppa*-*-osf*
3529 HP/PA Pro target hppa*-*-pro*
3530 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3531 386BSD i[3456]86-*-bsd*
3532 Sequent family i[3456]86-sequent-sysv4*
3533 i[3456]86-sequent-sysv*
3534 i[3456]86-sequent-bsd*
3535 SPARC running LynxOS sparc-*-lynxos*
3536 SPARC running SunOS 4 sparc-*-sunos4*
3537 Tsqware Sparclet sparclet-*-*
3538 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3540 *** Changes in GDB 6.0:
3544 Support for debugging the Objective-C programming language has been
3545 integrated into GDB.
3547 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3549 DWARF 2's Call Frame Information makes available compiler generated
3550 information that more exactly describes the program's run-time stack.
3551 By using this information, GDB is able to provide more robust stack
3554 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3555 have been updated to use a new backtrace mechanism which includes
3556 DWARF 2 CFI support.
3560 GDB's remote protocol has been extended to include support for hosted
3561 file I/O (where the remote target uses GDB's file system). See GDB's
3562 remote protocol documentation for details.
3564 * All targets using the new architecture framework.
3566 All of GDB's targets have been updated to use the new internal
3567 architecture framework. The way is now open for future GDB releases
3568 to include cross-architecture native debugging support (i386 on amd64,
3571 * GNU/Linux's Thread Local Storage (TLS)
3573 GDB now includes support for for the GNU/Linux implementation of
3574 per-thread variables.
3576 * GNU/Linux's Native POSIX Thread Library (NPTL)
3578 GDB's thread code has been updated to work with either the new
3579 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3581 * Separate debug info.
3583 GDB, in conjunction with BINUTILS, now supports a mechanism for
3584 automatically loading debug information from a separate file. Instead
3585 of shipping full debug and non-debug versions of system libraries,
3586 system integrators can now instead ship just the stripped libraries
3587 and optional debug files.
3589 * DWARF 2 Location Expressions
3591 DWARF 2 Location Expressions allow the compiler to more completely
3592 describe the location of variables (even in optimized code) to the
3595 GDB now includes preliminary support for location expressions (support
3596 for DW_OP_piece is still missing).
3600 A number of long standing bugs that caused GDB to die while starting a
3601 Java application have been fixed. GDB's Java support is now
3602 considered "useable".
3604 * GNU/Linux support for fork, vfork, and exec.
3606 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3607 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3610 * GDB supports logging output to a file
3612 There are two new commands, "set logging" and "show logging", which can be
3613 used to capture GDB's output to a file.
3615 * The meaning of "detach" has changed for gdbserver
3617 The "detach" command will now resume the application, as documented. To
3618 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3621 * d10v, m68hc11 `regs' command deprecated
3623 The `info registers' command has been updated so that it displays the
3624 registers using a format identical to the old `regs' command.
3628 A new command, "maint set profile on/off", has been added. This command can
3629 be used to enable or disable profiling while running GDB, to profile a
3630 session or a set of commands. In addition there is a new configure switch,
3631 "--enable-profiling", which will cause GDB to be compiled with profiling
3632 data, for more informative profiling results.
3634 * Default MI syntax changed to "mi2".
3636 The default MI (machine interface) syntax, enabled by the command line
3637 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3638 "mi1", can be enabled by specifying the option "-i=mi1".
3640 Support for the original "mi0" syntax (included in GDB 5.0) has been
3643 Fix for gdb/192: removed extraneous space when displaying frame level.
3644 Fix for gdb/672: update changelist is now output in mi list format.
3645 Fix for gdb/702: a -var-assign that updates the value now shows up
3646 in a subsequent -var-update.
3648 * New native configurations.
3650 FreeBSD/amd64 x86_64-*-freebsd*
3652 * Multi-arched targets.
3654 HP/PA HPUX11 hppa*-*-hpux*
3655 Renesas M32R/D w/simulator m32r-*-elf*
3657 * OBSOLETE configurations and files
3659 Configurations that have been declared obsolete in this release have
3660 been commented out. Unless there is activity to revive these
3661 configurations, the next release of GDB will have their sources
3662 permanently REMOVED.
3664 Z8000 simulator z8k-zilog-none or z8ksim
3665 Matsushita MN10200 w/simulator mn10200-*-*
3666 H8/500 simulator h8500-hitachi-hms or h8500hms
3667 HP/PA running BSD hppa*-*-bsd*
3668 HP/PA running OSF/1 hppa*-*-osf*
3669 HP/PA Pro target hppa*-*-pro*
3670 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3671 Sequent family i[3456]86-sequent-sysv4*
3672 i[3456]86-sequent-sysv*
3673 i[3456]86-sequent-bsd*
3674 Tsqware Sparclet sparclet-*-*
3675 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3677 * REMOVED configurations and files
3680 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3681 IBM AIX PS/2 i[3456]86-*-aix
3682 i386 running Mach 3.0 i[3456]86-*-mach3*
3683 i386 running Mach i[3456]86-*-mach*
3684 i386 running OSF/1 i[3456]86-*osf1mk*
3685 HP/Apollo 68k Family m68*-apollo*-sysv*,
3687 m68*-hp-bsd*, m68*-hp-hpux*
3688 Argonaut Risc Chip (ARC) arc-*-*
3689 Mitsubishi D30V d30v-*-*
3690 Fujitsu FR30 fr30-*-elf*
3691 OS/9000 i[34]86-*-os9k
3692 I960 with MON960 i960-*-coff
3694 * MIPS $fp behavior changed
3696 The convenience variable $fp, for the MIPS, now consistently returns
3697 the address of the current frame's base. Previously, depending on the
3698 context, $fp could refer to either $sp or the current frame's base
3699 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3700 The GNU Source-Level Debugger''.
3702 *** Changes in GDB 5.3:
3704 * GNU/Linux shared library multi-threaded performance improved.
3706 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3707 `/proc', in preference to `ptrace' for memory reads. This may result
3708 in an improvement in the start-up time of multi-threaded, shared
3709 library applications when run under GDB. One GDB user writes: ``loads
3710 shared libs like mad''.
3712 * ``gdbserver'' now supports multi-threaded applications on some targets
3714 Support for debugging multi-threaded applications which use
3715 the GNU/Linux LinuxThreads package has been added for
3716 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3717 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3719 * GDB now supports C/C++ preprocessor macros.
3721 GDB now expands preprocessor macro invocations in C/C++ expressions,
3722 and provides various commands for showing macro definitions and how
3725 The new command `macro expand EXPRESSION' expands any macro
3726 invocations in expression, and shows the result.
3728 The new command `show macro MACRO-NAME' shows the definition of the
3729 macro named MACRO-NAME, and where it was defined.
3731 Most compilers don't include information about macros in the debugging
3732 information by default. In GCC 3.1, for example, you need to compile
3733 your program with the options `-gdwarf-2 -g3'. If the macro
3734 information is present in the executable, GDB will read it.
3736 * Multi-arched targets.
3738 DEC Alpha (partial) alpha*-*-*
3739 DEC VAX (partial) vax-*-*
3741 National Semiconductor NS32000 (partial) ns32k-*-*
3742 Motorola 68000 (partial) m68k-*-*
3743 Motorola MCORE mcore-*-*
3747 Fujitsu FRV architecture added by Red Hat frv*-*-*
3750 * New native configurations
3752 Alpha NetBSD alpha*-*-netbsd*
3753 SH NetBSD sh*-*-netbsdelf*
3754 MIPS NetBSD mips*-*-netbsd*
3755 UltraSPARC NetBSD sparc64-*-netbsd*
3757 * OBSOLETE configurations and files
3759 Configurations that have been declared obsolete in this release have
3760 been commented out. Unless there is activity to revive these
3761 configurations, the next release of GDB will have their sources
3762 permanently REMOVED.
3764 Mitsubishi D30V d30v-*-*
3765 OS/9000 i[34]86-*-os9k
3766 IBM AIX PS/2 i[3456]86-*-aix
3767 Fujitsu FR30 fr30-*-elf*
3768 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3769 Argonaut Risc Chip (ARC) arc-*-*
3770 i386 running Mach 3.0 i[3456]86-*-mach3*
3771 i386 running Mach i[3456]86-*-mach*
3772 i386 running OSF/1 i[3456]86-*osf1mk*
3773 HP/Apollo 68k Family m68*-apollo*-sysv*,
3775 m68*-hp-bsd*, m68*-hp-hpux*
3776 I960 with MON960 i960-*-coff
3778 * OBSOLETE languages
3780 CHILL, a Pascal like language used by telecommunications companies.
3782 * REMOVED configurations and files
3784 AMD 29k family via UDI a29k-amd-udi, udi29k
3785 A29K VxWorks a29k-*-vxworks
3786 AMD 29000 embedded, using EBMON a29k-none-none
3787 AMD 29000 embedded with COFF a29k-none-coff
3788 AMD 29000 embedded with a.out a29k-none-aout
3790 testsuite/gdb.hp/gdb.threads-hp/ directory
3792 * New command "set max-user-call-depth <nnn>"
3794 This command allows the user to limit the call depth of user-defined
3795 commands. The default is 1024.
3797 * Changes in FreeBSD/i386 native debugging.
3799 Support for the "generate-core-file" has been added.
3801 * New commands "dump", "append", and "restore".
3803 These commands allow data to be copied from target memory
3804 to a bfd-format or binary file (dump and append), and back
3805 from a file into memory (restore).
3807 * Improved "next/step" support on multi-processor Alpha Tru64.
3809 The previous single-step mechanism could cause unpredictable problems,
3810 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3811 of a software single-step mechanism prevents this.
3813 *** Changes in GDB 5.2.1:
3821 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3822 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3823 Fix, by Joel Brobecker imported from mainline.
3825 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3826 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3827 Fix, by Fred Fish, imported from mainline.
3829 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3830 Surprisingly enough, it works now.
3831 By Michal Ludvig, imported from mainline.
3833 i386 hardware watchpoint support:
3834 avoid misses on second run for some targets.
3835 By Pierre Muller, imported from mainline.
3837 *** Changes in GDB 5.2:
3839 * New command "set trust-readonly-sections on[off]".
3841 This command is a hint that tells gdb that read-only sections
3842 really are read-only (ie. that their contents will not change).
3843 In this mode, gdb will go to the object file rather than the
3844 target to read memory from read-only sections (such as ".text").
3845 This can be a significant performance improvement on some
3846 (notably embedded) targets.
3848 * New command "generate-core-file" (or "gcore").
3850 This new gdb command allows the user to drop a core file of the child
3851 process state at any time. So far it's been implemented only for
3852 GNU/Linux and Solaris, but should be relatively easily ported to other
3853 hosts. Argument is core file name (defaults to core.<pid>).
3855 * New command line option
3857 GDB now accepts --pid or -p followed by a process id.
3859 * Change in command line behavior -- corefiles vs. process ids.
3861 There is a subtle behavior in the way in which GDB handles
3862 command line arguments. The first non-flag argument is always
3863 a program to debug, but the second non-flag argument may either
3864 be a corefile or a process id. Previously, GDB would attempt to
3865 open the second argument as a corefile, and if that failed, would
3866 issue a superfluous error message and then attempt to attach it as
3867 a process. Now, if the second argument begins with a non-digit,
3868 it will be treated as a corefile. If it begins with a digit,
3869 GDB will attempt to attach it as a process, and if no such process
3870 is found, will then attempt to open it as a corefile.
3872 * Changes in ARM configurations.
3874 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3875 configuration is fully multi-arch.
3877 * New native configurations
3879 ARM NetBSD arm*-*-netbsd*
3880 x86 OpenBSD i[3456]86-*-openbsd*
3881 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3882 Sparc64 running FreeBSD sparc64-*-freebsd*
3886 Sanyo XStormy16 xstormy16-elf
3888 * OBSOLETE configurations and files
3890 Configurations that have been declared obsolete in this release have
3891 been commented out. Unless there is activity to revive these
3892 configurations, the next release of GDB will have their sources
3893 permanently REMOVED.
3895 AMD 29k family via UDI a29k-amd-udi, udi29k
3896 A29K VxWorks a29k-*-vxworks
3897 AMD 29000 embedded, using EBMON a29k-none-none
3898 AMD 29000 embedded with COFF a29k-none-coff
3899 AMD 29000 embedded with a.out a29k-none-aout
3901 testsuite/gdb.hp/gdb.threads-hp/ directory
3903 * REMOVED configurations and files
3905 TI TMS320C80 tic80-*-*
3907 PowerPC Solaris powerpcle-*-solaris*
3908 PowerPC Windows NT powerpcle-*-cygwin32
3909 PowerPC Netware powerpc-*-netware*
3910 Harris/CXUX m88k m88*-harris-cxux*
3911 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3912 ns32k-utek-sysv* ns32k-utek-*
3913 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3914 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3915 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3916 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3917 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3919 * Changes to command line processing
3921 The new `--args' feature can be used to specify command-line arguments
3922 for the inferior from gdb's command line.
3924 * Changes to key bindings
3926 There is a new `operate-and-get-next' function bound to `C-o'.
3928 *** Changes in GDB 5.1.1
3930 Fix compile problem on DJGPP.
3932 Fix a problem with floating-point registers on the i386 being
3935 Fix to stop GDB crashing on .debug_str debug info.
3937 Numerous documentation fixes.
3939 Numerous testsuite fixes.
3941 *** Changes in GDB 5.1:
3943 * New native configurations
3945 Alpha FreeBSD alpha*-*-freebsd*
3946 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3947 MIPS GNU/Linux mips*-*-linux*
3948 MIPS SGI Irix 6.x mips*-sgi-irix6*
3949 ia64 AIX ia64-*-aix*
3950 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3954 Motorola 68HC11 and 68HC12 m68hc11-elf
3956 UltraSparc running GNU/Linux sparc64-*-linux*
3958 * OBSOLETE configurations and files
3960 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3961 Harris/CXUX m88k m88*-harris-cxux*
3962 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3963 ns32k-utek-sysv* ns32k-utek-*
3964 TI TMS320C80 tic80-*-*
3966 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3967 PowerPC Solaris powerpcle-*-solaris*
3968 PowerPC Windows NT powerpcle-*-cygwin32
3969 PowerPC Netware powerpc-*-netware*
3970 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3971 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3972 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3973 Apple Macintosh (MPW) host N/A
3975 stuff.c (Program to stuff files into a specially prepared space in kdb)
3976 kdb-start.c (Main loop for the standalone kernel debugger)
3978 Configurations that have been declared obsolete in this release have
3979 been commented out. Unless there is activity to revive these
3980 configurations, the next release of GDB will have their sources
3981 permanently REMOVED.
3983 * REMOVED configurations and files
3985 Altos 3068 m68*-altos-*
3986 Convex c1-*-*, c2-*-*
3988 ARM RISCix arm-*-* (as host)
3992 * GDB has been converted to ISO C.
3994 GDB's source code has been converted to ISO C. In particular, the
3995 sources are fully protoized, and rely on standard headers being
4000 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4002 * The MI enabled by default.
4004 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4005 revised and enabled by default. Packages which use GDB as a debugging
4006 engine behind a UI or another front end are encouraged to switch to
4007 using the GDB/MI interface, instead of the old annotations interface
4008 which is now deprecated.
4010 * Support for debugging Pascal programs.
4012 GDB now includes support for debugging Pascal programs. The following
4013 main features are supported:
4015 - Pascal-specific data types such as sets;
4017 - automatic recognition of Pascal sources based on file-name
4020 - Pascal-style display of data types, variables, and functions;
4022 - a Pascal expression parser.
4024 However, some important features are not yet supported.
4026 - Pascal string operations are not supported at all;
4028 - there are some problems with boolean types;
4030 - Pascal type hexadecimal constants are not supported
4031 because they conflict with the internal variables format;
4033 - support for Pascal objects and classes is not full yet;
4035 - unlike Pascal, GDB is case-sensitive for symbol names.
4037 * Changes in completion.
4039 Commands such as `shell', `run' and `set args', which pass arguments
4040 to inferior programs, now complete on file names, similar to what
4041 users expect at the shell prompt.
4043 Commands which accept locations, such as `disassemble', `print',
4044 `breakpoint', `until', etc. now complete on filenames as well as
4045 program symbols. Thus, if you type "break foob TAB", and the source
4046 files linked into the programs include `foobar.c', that file name will
4047 be one of the candidates for completion. However, file names are not
4048 considered for completion after you typed a colon that delimits a file
4049 name from a name of a function in that file, as in "break foo.c:bar".
4051 `set demangle-style' completes on available demangling styles.
4053 * New platform-independent commands:
4055 It is now possible to define a post-hook for a command as well as a
4056 hook that runs before the command. For more details, see the
4057 documentation of `hookpost' in the GDB manual.
4059 * Changes in GNU/Linux native debugging.
4061 Support for debugging multi-threaded programs has been completely
4062 revised for all platforms except m68k and sparc. You can now debug as
4063 many threads as your system allows you to have.
4065 Attach/detach is supported for multi-threaded programs.
4067 Support for SSE registers was added for x86. This doesn't work for
4068 multi-threaded programs though.
4070 * Changes in MIPS configurations.
4072 Multi-arch support is enabled for all MIPS configurations.
4074 GDB can now be built as native debugger on SGI Irix 6.x systems for
4075 debugging n32 executables. (Debugging 64-bit executables is not yet
4078 * Unified support for hardware watchpoints in all x86 configurations.
4080 Most (if not all) native x86 configurations support hardware-assisted
4081 breakpoints and watchpoints in a unified manner. This support
4082 implements debug register sharing between watchpoints, which allows to
4083 put a virtually infinite number of watchpoints on the same address,
4084 and also supports watching regions up to 16 bytes with several debug
4087 The new maintenance command `maintenance show-debug-regs' toggles
4088 debugging print-outs in functions that insert, remove, and test
4089 watchpoints and hardware breakpoints.
4091 * Changes in the DJGPP native configuration.
4093 New command ``info dos sysinfo'' displays assorted information about
4094 the CPU, OS, memory, and DPMI server.
4096 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4097 display information about segment descriptors stored in GDT, LDT, and
4100 New commands ``info dos pde'' and ``info dos pte'' display entries
4101 from Page Directory and Page Tables (for now works with CWSDPMI only).
4102 New command ``info dos address-pte'' displays the Page Table entry for
4103 a given linear address.
4105 GDB can now pass command lines longer than 126 characters to the
4106 program being debugged (requires an update to the libdbg.a library
4107 which is part of the DJGPP development kit).
4109 DWARF2 debug info is now supported.
4111 It is now possible to `step' and `next' through calls to `longjmp'.
4113 * Changes in documentation.
4115 All GDB documentation was converted to GFDL, the GNU Free
4116 Documentation License.
4118 Tracepoints-related commands are now fully documented in the GDB
4121 TUI, the Text-mode User Interface, is now documented in the manual.
4123 Tracepoints-related commands are now fully documented in the GDB
4126 The "GDB Internals" manual now has an index. It also includes
4127 documentation of `ui_out' functions, GDB coding standards, x86
4128 hardware watchpoints, and memory region attributes.
4130 * GDB's version number moved to ``version.in''
4132 The Makefile variable VERSION has been replaced by the file
4133 ``version.in''. People creating GDB distributions should update the
4134 contents of this file.
4138 GUD support is now a standard part of the EMACS distribution.
4140 *** Changes in GDB 5.0:
4142 * Improved support for debugging FP programs on x86 targets
4144 Unified and much-improved support for debugging floating-point
4145 programs on all x86 targets. In particular, ``info float'' now
4146 displays the FP registers in the same format on all x86 targets, with
4147 greater level of detail.
4149 * Improvements and bugfixes in hardware-assisted watchpoints
4151 It is now possible to watch array elements, struct members, and
4152 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4153 on x86 targets no longer erroneously trigger when the address is
4156 * Improvements in the native DJGPP version of GDB
4158 The distribution now includes all the scripts and auxiliary files
4159 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4160 machines ``out of the box''.
4162 The DJGPP version can now debug programs that use signals. It is
4163 possible to catch signals that happened in the debuggee, deliver
4164 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4165 would kill the program being debugged.) Programs that hook hardware
4166 interrupts (keyboard, timer, etc.) can also be debugged.
4168 It is now possible to debug DJGPP programs that redirect their
4169 standard handles or switch them to raw (as opposed to cooked) mode, or
4170 even close them. The command ``run < foo > bar'' works as expected,
4171 and ``info terminal'' reports useful information about the debuggee's
4172 terminal, including raw/cooked mode, redirection, etc.
4174 The DJGPP version now uses termios functions for console I/O, which
4175 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4178 DOS-style file names with drive letters are now fully supported by
4181 It is now possible to debug DJGPP programs that switch their working
4182 directory. It is also possible to rerun the debuggee any number of
4183 times without restarting GDB; thus, you can use the same setup,
4184 breakpoints, etc. for many debugging sessions.
4186 * New native configurations
4188 ARM GNU/Linux arm*-*-linux*
4189 PowerPC GNU/Linux powerpc-*-linux*
4193 Motorola MCore mcore-*-*
4194 x86 VxWorks i[3456]86-*-vxworks*
4195 PowerPC VxWorks powerpc-*-vxworks*
4196 TI TMS320C80 tic80-*-*
4198 * OBSOLETE configurations
4200 Altos 3068 m68*-altos-*
4201 Convex c1-*-*, c2-*-*
4203 ARM RISCix arm-*-* (as host)
4206 Configurations that have been declared obsolete will be commented out,
4207 but the code will be left in place. If there is no activity to revive
4208 these configurations before the next release of GDB, the sources will
4209 be permanently REMOVED.
4211 * Gould support removed
4213 Support for the Gould PowerNode and NP1 has been removed.
4215 * New features for SVR4
4217 On SVR4 native platforms (such as Solaris), if you attach to a process
4218 without first loading a symbol file, GDB will now attempt to locate and
4219 load symbols from the running process's executable file.
4221 * Many C++ enhancements
4223 C++ support has been greatly improved. Overload resolution now works properly
4224 in almost all cases. RTTI support is on the way.
4226 * Remote targets can connect to a sub-program
4228 A popen(3) style serial-device has been added. This device starts a
4229 sub-process (such as a stand-alone simulator) and then communicates
4230 with that. The sub-program to run is specified using the syntax
4231 ``|<program> <args>'' vis:
4233 (gdb) set remotedebug 1
4234 (gdb) target extended-remote |mn10300-elf-sim program-args
4236 * MIPS 64 remote protocol
4238 A long standing bug in the mips64 remote protocol where by GDB
4239 expected certain 32 bit registers (ex SR) to be transfered as 32
4240 instead of 64 bits has been fixed.
4242 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4243 added to provide backward compatibility with older versions of GDB.
4245 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4247 The command ``set remotebinarydownload'' command has been replaced by
4248 ``set remote X-packet''. Other commands in ``set remote'' family
4249 include ``set remote P-packet''.
4251 * Breakpoint commands accept ranges.
4253 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4254 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4255 ``tracepoint passcount'' also accepts a range of tracepoints.
4257 * ``apropos'' command added.
4259 The ``apropos'' command searches through command names and
4260 documentation strings, printing out matches, making it much easier to
4261 try to find a command that does what you are looking for.
4265 A new machine oriented interface (MI) has been added to GDB. This
4266 interface is designed for debug environments running GDB as a separate
4267 process. This is part of the long term libGDB project. See the
4268 "GDB/MI" chapter of the GDB manual for further information. It can be
4269 enabled by configuring with:
4271 .../configure --enable-gdbmi
4273 *** Changes in GDB-4.18:
4275 * New native configurations
4277 HP-UX 10.20 hppa*-*-hpux10.20
4278 HP-UX 11.x hppa*-*-hpux11.0*
4279 M68K GNU/Linux m68*-*-linux*
4283 Fujitsu FR30 fr30-*-elf*
4284 Intel StrongARM strongarm-*-*
4285 Mitsubishi D30V d30v-*-*
4287 * OBSOLETE configurations
4289 Gould PowerNode, NP1 np1-*-*, pn-*-*
4291 Configurations that have been declared obsolete will be commented out,
4292 but the code will be left in place. If there is no activity to revive
4293 these configurations before the next release of GDB, the sources will
4294 be permanently REMOVED.
4298 As a compatibility experiment, GDB's source files buildsym.h and
4299 buildsym.c have been converted to pure standard C, no longer
4300 containing any K&R compatibility code. We believe that all systems in
4301 use today either come with a standard C compiler, or have a GCC port
4302 available. If this is not true, please report the affected
4303 configuration to bug-gdb@gnu.org immediately. See the README file for
4304 information about getting a standard C compiler if you don't have one
4309 GDB now uses readline 2.2.
4311 * set extension-language
4313 You can now control the mapping between filename extensions and source
4314 languages by using the `set extension-language' command. For instance,
4315 you can ask GDB to treat .c files as C++ by saying
4316 set extension-language .c c++
4317 The command `info extensions' lists all of the recognized extensions
4318 and their associated languages.
4320 * Setting processor type for PowerPC and RS/6000
4322 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4323 you can use the `set processor' command to specify what variant of the
4324 PowerPC family you are debugging. The command
4328 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4329 following PowerPC and RS6000 variants:
4331 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4332 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4334 403GC IBM PowerPC 403GC
4335 505 Motorola PowerPC 505
4336 860 Motorola PowerPC 860 or 850
4337 601 Motorola PowerPC 601
4338 602 Motorola PowerPC 602
4339 603 Motorola/IBM PowerPC 603 or 603e
4340 604 Motorola PowerPC 604 or 604e
4341 750 Motorola/IBM PowerPC 750 or 750
4343 At the moment, this command just tells GDB what to name the
4344 special-purpose processor registers. Since almost all the affected
4345 registers are inaccessible to user-level programs, this command is
4346 only useful for remote debugging in its present form.
4350 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4351 more extensive support for HP-UX. Added features include shared
4352 library support, kernel threads and hardware watchpoints for 11.00,
4353 support for HP's ANSI C and C++ compilers, and a compatibility mode
4354 for xdb and dbx commands.
4358 HP's donation includes the new concept of catchpoints, which is a
4359 generalization of the old catch command. On HP-UX, it is now possible
4360 to catch exec, fork, and vfork, as well as library loading.
4362 This means that the existing catch command has changed; its first
4363 argument now specifies the type of catch to be set up. See the
4364 output of "help catch" for a list of catchpoint types.
4366 * Debugging across forks
4368 On HP-UX, you can choose which process to debug when a fork() happens
4373 HP has donated a curses-based terminal user interface (TUI). To get
4374 it, build with --enable-tui. Although this can be enabled for any
4375 configuration, at present it only works for native HP debugging.
4377 * GDB remote protocol additions
4379 A new protocol packet 'X' that writes binary data is now available.
4380 Default behavior is to try 'X', then drop back to 'M' if the stub
4381 fails to respond. The settable variable `remotebinarydownload'
4382 allows explicit control over the use of 'X'.
4384 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4385 full 64-bit address. The command
4387 set remoteaddresssize 32
4389 can be used to revert to the old behaviour. For existing remote stubs
4390 the change should not be noticed, as the additional address information
4393 In order to assist in debugging stubs, you may use the maintenance
4394 command `packet' to send any text string to the stub. For instance,
4396 maint packet heythere
4398 sends the packet "$heythere#<checksum>". Note that it is very easy to
4399 disrupt a debugging session by sending the wrong packet at the wrong
4402 The compare-sections command allows you to compare section data on the
4403 target to what is in the executable file without uploading or
4404 downloading, by comparing CRC checksums.
4406 * Tracing can collect general expressions
4408 You may now collect general expressions at tracepoints. This requires
4409 further additions to the target-side stub; see tracepoint.c and
4410 doc/agentexpr.texi for further details.
4412 * mask-address variable for Mips
4414 For Mips targets, you may control the zeroing of the upper 32 bits of
4415 a 64-bit address by entering `set mask-address on'. This is mainly
4416 of interest to users of embedded R4xxx and R5xxx processors.
4418 * Higher serial baud rates
4420 GDB's serial code now allows you to specify baud rates 57600, 115200,
4421 230400, and 460800 baud. (Note that your host system may not be able
4422 to achieve all of these rates.)
4426 The i960 configuration now includes an initial implementation of a
4427 builtin simulator, contributed by Jim Wilson.
4430 *** Changes in GDB-4.17:
4432 * New native configurations
4434 Alpha GNU/Linux alpha*-*-linux*
4435 Unixware 2.x i[3456]86-unixware2*
4436 Irix 6.x mips*-sgi-irix6*
4437 PowerPC GNU/Linux powerpc-*-linux*
4438 PowerPC Solaris powerpcle-*-solaris*
4439 Sparc GNU/Linux sparc-*-linux*
4440 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4444 Argonaut Risc Chip (ARC) arc-*-*
4445 Hitachi H8/300S h8300*-*-*
4446 Matsushita MN10200 w/simulator mn10200-*-*
4447 Matsushita MN10300 w/simulator mn10300-*-*
4448 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4449 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4450 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4451 Mitsubishi D10V w/simulator d10v-*-*
4452 Mitsubishi M32R/D w/simulator m32r-*-elf*
4453 Tsqware Sparclet sparclet-*-*
4454 NEC V850 w/simulator v850-*-*
4456 * New debugging protocols
4458 ARM with RDI protocol arm*-*-*
4459 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4460 DDB and LSI variants of PMON protocol mips*-*-*
4461 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4462 PowerPC with SDS protocol powerpc{,le}-*-eabi
4463 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4467 All configurations can now understand and use the DWARF 2 debugging
4468 format. The choice is automatic, if the symbol file contains DWARF 2
4473 GDB now includes basic Java language support. This support is
4474 only useful with Java compilers that produce native machine code.
4476 * solib-absolute-prefix and solib-search-path
4478 For SunOS and SVR4 shared libraries, you may now set the prefix for
4479 loading absolute shared library symbol files, and the search path for
4480 locating non-absolute shared library symbol files.
4482 * Live range splitting
4484 GDB can now effectively debug code for which GCC has performed live
4485 range splitting as part of its optimization. See gdb/doc/LRS for
4486 more details on the expected format of the stabs information.
4490 GDB's support for the GNU Hurd, including thread debugging, has been
4491 updated to work with current versions of the Hurd.
4495 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4496 instruction set. ARM GDB automatically detects when Thumb
4497 instructions are in use, and adjusts disassembly and backtracing
4502 GDB's MIPS target configurations now handle the MIP16 16-bit
4507 GDB now includes support for overlays; if an executable has been
4508 linked such that multiple sections are based at the same address, GDB
4509 will decide which section to use for symbolic info. You can choose to
4510 control the decision manually, using overlay commands, or implement
4511 additional target-side support and use "overlay load-target" to bring
4512 in the overlay mapping. Do "help overlay" for more detail.
4516 The command "info symbol <address>" displays information about
4517 the symbol at the specified address.
4521 The standard remote protocol now includes an extension that allows
4522 asynchronous collection and display of trace data. This requires
4523 extensive support in the target-side debugging stub. Tracing mode
4524 includes a new interaction mode in GDB and new commands: see the
4525 file tracepoint.c for more details.
4529 Configurations for embedded MIPS now include a simulator contributed
4530 by Cygnus Solutions. The simulator supports the instruction sets
4531 of most MIPS variants.
4535 Sparc configurations may now include the ERC32 simulator contributed
4536 by the European Space Agency. The simulator is not built into
4537 Sparc targets by default; configure with --enable-sim to include it.
4541 For target configurations that may include multiple variants of a
4542 basic architecture (such as MIPS and SH), you may now set the
4543 architecture explicitly. "set arch" sets, "info arch" lists
4544 the possible architectures.
4546 *** Changes in GDB-4.16:
4548 * New native configurations
4550 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4551 M68K NetBSD m68k-*-netbsd*
4552 PowerPC AIX 4.x powerpc-*-aix*
4553 PowerPC MacOS powerpc-*-macos*
4554 PowerPC Windows NT powerpcle-*-cygwin32
4555 RS/6000 AIX 4.x rs6000-*-aix4*
4559 ARM with RDP protocol arm-*-*
4560 I960 with MON960 i960-*-coff
4561 MIPS VxWorks mips*-*-vxworks*
4562 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4563 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4565 Matra Sparclet sparclet-*-*
4569 The powerpc-eabi configuration now includes the PSIM simulator,
4570 contributed by Andrew Cagney, with assistance from Mike Meissner.
4571 PSIM is a very elaborate model of the PowerPC, including not only
4572 basic instruction set execution, but also details of execution unit
4573 performance and I/O hardware. See sim/ppc/README for more details.
4577 GDB now works with Solaris 2.5.
4579 * Windows 95/NT native
4581 GDB will now work as a native debugger on Windows 95 and Windows NT.
4582 To build it from source, you must use the "gnu-win32" environment,
4583 which uses a DLL to emulate enough of Unix to run the GNU tools.
4584 Further information, binaries, and sources are available at
4585 ftp.cygnus.com, under pub/gnu-win32.
4587 * dont-repeat command
4589 If a user-defined command includes the command `dont-repeat', then the
4590 command will not be repeated if the user just types return. This is
4591 useful if the command is time-consuming to run, so that accidental
4592 extra keystrokes don't run the same command many times.
4594 * Send break instead of ^C
4596 The standard remote protocol now includes an option to send a break
4597 rather than a ^C to the target in order to interrupt it. By default,
4598 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4600 * Remote protocol timeout
4602 The standard remote protocol includes a new variable `remotetimeout'
4603 that allows you to set the number of seconds before GDB gives up trying
4604 to read from the target. The default value is 2.
4606 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4608 By default GDB will automatically keep track of objects as they are
4609 loaded and unloaded by the dynamic linker. By using the command `set
4610 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4611 when shared library events occur, thus allowing you to set breakpoints
4612 in shared libraries which are explicitly loaded by the inferior.
4614 Note this feature does not work on hpux8. On hpux9 you must link
4615 /usr/lib/end.o into your program. This feature should work
4616 automatically on hpux10.
4618 * Irix 5.x hardware watchpoint support
4620 Irix 5 configurations now support the use of hardware watchpoints.
4622 * Mips protocol "SYN garbage limit"
4624 When debugging a Mips target using the `target mips' protocol, you
4625 may set the number of characters that GDB will ignore by setting
4626 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4627 every character. The default value is 1050.
4629 * Recording and replaying remote debug sessions
4631 If you set `remotelogfile' to the name of a file, gdb will write to it
4632 a recording of a remote debug session. This recording may then be
4633 replayed back to gdb using "gdbreplay". See gdbserver/README for
4634 details. This is useful when you have a problem with GDB while doing
4635 remote debugging; you can make a recording of the session and send it
4636 to someone else, who can then recreate the problem.
4638 * Speedups for remote debugging
4640 GDB includes speedups for downloading and stepping MIPS systems using
4641 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4642 and more efficient S-record downloading.
4644 * Memory use reductions and statistics collection
4646 GDB now uses less memory and reports statistics about memory usage.
4647 Try the `maint print statistics' command, for example.
4649 *** Changes in GDB-4.15:
4651 * Psymtabs for XCOFF
4653 The symbol reader for AIX GDB now uses partial symbol tables. This
4654 can greatly improve startup time, especially for large executables.
4656 * Remote targets use caching
4658 Remote targets now use a data cache to speed up communication with the
4659 remote side. The data cache could lead to incorrect results because
4660 it doesn't know about volatile variables, thus making it impossible to
4661 debug targets which use memory mapped I/O devices. `set remotecache
4662 off' turns the the data cache off.
4664 * Remote targets may have threads
4666 The standard remote protocol now includes support for multiple threads
4667 in the target system, using new protocol commands 'H' and 'T'. See
4668 gdb/remote.c for details.
4672 If GDB is configured with `--enable-netrom', then it will include
4673 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4674 acts as though it is a bank of ROM on the target board, but you can
4675 write into it over the network. GDB's support consists only of
4676 support for fast loading into the emulated ROM; to debug, you must use
4677 another protocol, such as standard remote protocol. The usual
4678 sequence is something like
4680 target nrom <netrom-hostname>
4682 target remote <netrom-hostname>:1235
4686 GDB now includes support for the Apple Macintosh, as a host only. It
4687 may be run as either an MPW tool or as a standalone application, and
4688 it can debug through the serial port. All the usual GDB commands are
4689 available, but to the target command, you must supply "serial" as the
4690 device type instead of "/dev/ttyXX". See mpw-README in the main
4691 directory for more information on how to build. The MPW configuration
4692 scripts */mpw-config.in support only a few targets, and only the
4693 mips-idt-ecoff target has been tested.
4697 GDB configuration now uses autoconf. This is not user-visible,
4698 but does simplify configuration and building.
4702 GDB now supports hpux10.
4704 *** Changes in GDB-4.14:
4706 * New native configurations
4708 x86 FreeBSD i[345]86-*-freebsd
4709 x86 NetBSD i[345]86-*-netbsd
4710 NS32k NetBSD ns32k-*-netbsd
4711 Sparc NetBSD sparc-*-netbsd
4715 A29K VxWorks a29k-*-vxworks
4716 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4717 CPU32 EST-300 emulator m68*-*-est*
4718 PowerPC ELF powerpc-*-elf
4721 * Alpha OSF/1 support for procfs
4723 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4724 possible to attach to running processes. As the mounting of the /proc
4725 filesystem is optional on the Alpha, GDB automatically determines
4726 the availability of /proc during startup. This can lead to problems
4727 if /proc is unmounted after GDB has been started.
4729 * Arguments to user-defined commands
4731 User commands may accept up to 10 arguments separated by whitespace.
4732 Arguments are accessed within the user command via $arg0..$arg9. A
4735 print $arg0 + $arg1 + $arg2
4737 To execute the command use:
4740 Defines the command "adder" which prints the sum of its three arguments.
4741 Note the arguments are text substitutions, so they may reference variables,
4742 use complex expressions, or even perform inferior function calls.
4744 * New `if' and `while' commands
4746 This makes it possible to write more sophisticated user-defined
4747 commands. Both commands take a single argument, which is the
4748 expression to evaluate, and must be followed by the commands to
4749 execute, one per line, if the expression is nonzero, the list being
4750 terminated by the word `end'. The `if' command list may include an
4751 `else' word, which causes the following commands to be executed only
4752 if the expression is zero.
4754 * Fortran source language mode
4756 GDB now includes partial support for Fortran 77. It will recognize
4757 Fortran programs and can evaluate a subset of Fortran expressions, but
4758 variables and functions may not be handled correctly. GDB will work
4759 with G77, but does not yet know much about symbols emitted by other
4762 * Better HPUX support
4764 Most debugging facilities now work on dynamic executables for HPPAs
4765 running hpux9 or later. You can attach to running dynamically linked
4766 processes, but by default the dynamic libraries will be read-only, so
4767 for instance you won't be able to put breakpoints in them. To change
4768 that behavior do the following before running the program:
4774 This will cause the libraries to be mapped private and read-write.
4775 To revert to the normal behavior, do this:
4781 You cannot set breakpoints or examine data in the library until after
4782 the library is loaded if the function/data symbols do not have
4785 GDB can now also read debug symbols produced by the HP C compiler on
4786 HPPAs (sorry, no C++, Fortran or 68k support).
4788 * Target byte order now dynamically selectable
4790 You can choose which byte order to use with a target system, via the
4791 commands "set endian big" and "set endian little", and you can see the
4792 current setting by using "show endian". You can also give the command
4793 "set endian auto", in which case GDB will use the byte order
4794 associated with the executable. Currently, only embedded MIPS
4795 configurations support dynamic selection of target byte order.
4797 * New DOS host serial code
4799 This version uses DPMI interrupts to handle buffered I/O, so you
4800 no longer need to run asynctsr when debugging boards connected to
4803 *** Changes in GDB-4.13:
4805 * New "complete" command
4807 This lists all the possible completions for the rest of the line, if it
4808 were to be given as a command itself. This is intended for use by emacs.
4810 * Trailing space optional in prompt
4812 "set prompt" no longer adds a space for you after the prompt you set. This
4813 allows you to set a prompt which ends in a space or one that does not.
4815 * Breakpoint hit counts
4817 "info break" now displays a count of the number of times the breakpoint
4818 has been hit. This is especially useful in conjunction with "ignore"; you
4819 can ignore a large number of breakpoint hits, look at the breakpoint info
4820 to see how many times the breakpoint was hit, then run again, ignoring one
4821 less than that number, and this will get you quickly to the last hit of
4824 * Ability to stop printing at NULL character
4826 "set print null-stop" will cause GDB to stop printing the characters of
4827 an array when the first NULL is encountered. This is useful when large
4828 arrays actually contain only short strings.
4830 * Shared library breakpoints
4832 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4833 breakpoints in shared libraries before the executable is run.
4835 * Hardware watchpoints
4837 There is a new hardware breakpoint for the watch command for sparclite
4838 targets. See gdb/sparclite/hw_breakpoint.note.
4840 Hardware watchpoints are also now supported under GNU/Linux.
4844 Annotations have been added. These are for use with graphical interfaces,
4845 and are still experimental. Currently only gdba.el uses these.
4847 * Improved Irix 5 support
4849 GDB now works properly with Irix 5.2.
4851 * Improved HPPA support
4853 GDB now works properly with the latest GCC and GAS.
4855 * New native configurations
4857 Sequent PTX4 i[34]86-sequent-ptx4
4858 HPPA running OSF/1 hppa*-*-osf*
4859 Atari TT running SVR4 m68*-*-sysv4*
4860 RS/6000 LynxOS rs6000-*-lynxos*
4864 OS/9000 i[34]86-*-os9k
4865 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4868 * Hitachi SH7000 and E7000-PC ICE support
4870 There is now support for communicating with the Hitachi E7000-PC ICE.
4871 This is available automatically when GDB is configured for the SH.
4875 As usual, a variety of small fixes and improvements, both generic
4876 and configuration-specific. See the ChangeLog for more detail.
4878 *** Changes in GDB-4.12:
4880 * Irix 5 is now supported
4884 GDB-4.12 on the HPPA has a number of changes which make it unable
4885 to debug the output from the currently released versions of GCC and
4886 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4887 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4888 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4891 *** Changes in GDB-4.11:
4893 * User visible changes:
4897 The "set remotedebug" option is now consistent between the mips remote
4898 target, remote targets using the gdb-specific protocol, UDI (AMD's
4899 debug protocol for the 29k) and the 88k bug monitor. It is now an
4900 integer specifying a debug level (normally 0 or 1, but 2 means more
4901 debugging info for the mips target).
4903 * DEC Alpha native support
4905 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4906 debug info, but GDB works fairly well with the DEC compiler and should
4907 work with a future GCC release. See the README file for a few
4908 Alpha-specific notes.
4910 * Preliminary thread implementation
4912 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4914 * LynxOS native and target support for 386
4916 This release has been hosted on LynxOS 2.2, and also can be configured
4917 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4920 * Improvements in C++ mangling/demangling.
4922 This release has much better g++ debugging, specifically in name
4923 mangling/demangling, virtual function calls, print virtual table,
4924 call methods, ...etc.
4926 *** Changes in GDB-4.10:
4928 * User visible changes:
4930 Remote debugging using the GDB-specific (`target remote') protocol now
4931 supports the `load' command. This is only useful if you have some
4932 other way of getting the stub to the target system, and you can put it
4933 somewhere in memory where it won't get clobbered by the download.
4935 Filename completion now works.
4937 When run under emacs mode, the "info line" command now causes the
4938 arrow to point to the line specified. Also, "info line" prints
4939 addresses in symbolic form (as well as hex).
4941 All vxworks based targets now support a user settable option, called
4942 vxworks-timeout. This option represents the number of seconds gdb
4943 should wait for responses to rpc's. You might want to use this if
4944 your vxworks target is, perhaps, a slow software simulator or happens
4945 to be on the far side of a thin network line.
4949 This release contains support for using a DEC alpha as a GDB host for
4950 cross debugging. Native alpha debugging is not supported yet.
4953 *** Changes in GDB-4.9:
4957 This is the first GDB release which is accompanied by a matching testsuite.
4958 The testsuite requires installation of dejagnu, which should be available
4959 via ftp from most sites that carry GNU software.
4963 'Cfront' style demangling has had its name changed to 'ARM' style, to
4964 emphasize that it was written from the specifications in the C++ Annotated
4965 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4966 disclaimers, it still generated too much confusion with users attempting to
4967 use gdb with AT&T cfront.
4971 GDB now uses a standard remote interface to a simulator library.
4972 So far, the library contains simulators for the Zilog Z8001/2, the
4973 Hitachi H8/300, H8/500 and Super-H.
4975 * New targets supported
4977 H8/300 simulator h8300-hitachi-hms or h8300hms
4978 H8/500 simulator h8500-hitachi-hms or h8500hms
4979 SH simulator sh-hitachi-hms or sh
4980 Z8000 simulator z8k-zilog-none or z8ksim
4981 IDT MIPS board over serial line mips-idt-ecoff
4983 Cross-debugging to GO32 targets is supported. It requires a custom
4984 version of the i386-stub.c module which is integrated with the
4985 GO32 memory extender.
4987 * New remote protocols
4989 MIPS remote debugging protocol.
4991 * New source languages supported
4993 This version includes preliminary support for Chill, a Pascal like language
4994 used by telecommunications companies. Chill support is also being integrated
4995 into the GNU compiler, but we don't know when it will be publically available.
4998 *** Changes in GDB-4.8:
5000 * HP Precision Architecture supported
5002 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5003 version of this support was available as a set of patches from the
5004 University of Utah. GDB does not support debugging of programs
5005 compiled with the HP compiler, because HP will not document their file
5006 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5007 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5009 Many problems in the preliminary version have been fixed.
5011 * Faster and better demangling
5013 We have improved template demangling and fixed numerous bugs in the GNU style
5014 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5015 character types (wchar_t) are now supported. Demangling of each symbol is now
5016 only done once, and is cached when the symbol table for a file is read in.
5017 This results in a small increase in memory usage for C programs, a moderate
5018 increase in memory usage for C++ programs, and a fantastic speedup in
5021 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5022 from the specifications in the Annotated Reference Manual, which AT&T's
5023 compiler does not actually implement.
5025 * G++ multiple inheritance compiler problem
5027 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5028 inheritance lattices was reworked to properly discover ambiguities. We
5029 recently found an example which causes this new algorithm to fail in a
5030 very subtle way, producing bad debug information for those classes.
5031 The file 'gcc.patch' (in this directory) can be applied to gcc to
5032 circumvent the problem. A future GCC release will contain a complete
5035 The previous G++ debug info problem (mentioned below for the gdb-4.7
5036 release) is fixed in gcc version 2.3.2.
5038 * Improved configure script
5040 The `configure' script will now attempt to guess your system type if
5041 you don't supply a host system type. The old scheme of supplying a
5042 host system triplet is preferable over using this. All the magic is
5043 done in the new `config.guess' script. Examine it for details.
5045 We have also brought our configure script much more in line with the FSF's
5046 version. It now supports the --with-xxx options. In particular,
5047 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5048 The resulting GDB will not be able to read arbitrary object file formats --
5049 only the format ``expected'' to be used on the configured target system.
5050 We hope to make this the default in a future release.
5052 * Documentation improvements
5054 There's new internal documentation on how to modify GDB, and how to
5055 produce clean changes to the code. We implore people to read it
5056 before submitting changes.
5058 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5059 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5060 `info' files are also provided. To build `info' files from scratch,
5061 you will need the latest `makeinfo' release, which will be available in
5062 a future texinfo-X.Y release.
5064 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5065 We're not sure exactly which versions have this problem, but it has
5066 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5067 or better. If that isn't possible, there is a patch in
5068 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5069 around this problem.
5073 GDB now supports array constants that can be used in expressions typed in by
5074 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5075 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5078 The new directory `gdb/sparclite' contains a program that demonstrates
5079 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5081 * New native hosts supported
5083 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5084 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5086 * New targets supported
5088 AMD 29k family via UDI a29k-amd-udi or udi29k
5090 * New file formats supported
5092 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5093 HPUX core files, and SCO 3.2v2 core files.
5097 Attaching to processes now works again; thanks for the many bug reports.
5099 We have also stomped on a bunch of core dumps caused by
5100 printf_filtered("%s") problems.
5102 We eliminated a copyright problem on the rpc and ptrace header files
5103 for VxWorks, which was discovered at the last minute during the 4.7
5104 release. You should now be able to build a VxWorks GDB.
5106 You can now interrupt gdb while an attached process is running. This
5107 will cause the attached process to stop, and give control back to GDB.
5109 We fixed problems caused by using too many file descriptors
5110 for reading symbols from object files and libraries. This was
5111 especially a problem for programs that used many (~100) shared
5114 The `step' command now only enters a subroutine if there is line number
5115 information for the subroutine. Otherwise it acts like the `next'
5116 command. Previously, `step' would enter subroutines if there was
5117 any debugging information about the routine. This avoids problems
5118 when using `cc -g1' on MIPS machines.
5120 * Internal improvements
5122 GDB's internal interfaces have been improved to make it easier to support
5123 debugging of multiple languages in the future.
5125 GDB now uses a common structure for symbol information internally.
5126 Minimal symbols (derived from linkage symbols in object files), partial
5127 symbols (from a quick scan of debug information), and full symbols
5128 contain a common subset of information, making it easier to write
5129 shared code that handles any of them.
5131 * New command line options
5133 We now accept --silent as an alias for --quiet.
5137 The memory-mapped-malloc library is now licensed under the GNU Library
5138 General Public License.
5140 *** Changes in GDB-4.7:
5142 * Host/native/target split
5144 GDB has had some major internal surgery to untangle the support for
5145 hosts and remote targets. Now, when you configure GDB for a remote
5146 target, it will no longer load in all of the support for debugging
5147 local programs on the host. When fully completed and tested, this will
5148 ensure that arbitrary host/target combinations are possible.
5150 The primary conceptual shift is to separate the non-portable code in
5151 GDB into three categories. Host specific code is required any time GDB
5152 is compiled on that host, regardless of the target. Target specific
5153 code relates to the peculiarities of the target, but can be compiled on
5154 any host. Native specific code is everything else: it can only be
5155 built when the host and target are the same system. Child process
5156 handling and core file support are two common `native' examples.
5158 GDB's use of /proc for controlling Unix child processes is now cleaner.
5159 It has been split out into a single module under the `target_ops' vector,
5160 plus two native-dependent functions for each system that uses /proc.
5162 * New hosts supported
5164 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5165 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5166 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5168 * New targets supported
5170 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5171 68030 and CPU32 m68030-*-*, m68332-*-*
5173 * New native hosts supported
5175 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5176 (386bsd is not well tested yet)
5177 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5179 * New file formats supported
5181 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5182 supports reading of `a.out.adobe' object files, which are an a.out
5183 format extended with minimal information about multiple sections.
5187 `show copying' is the same as the old `info copying'.
5188 `show warranty' is the same as `info warrantee'.
5189 These were renamed for consistency. The old commands continue to work.
5191 `info handle' is a new alias for `info signals'.
5193 You can now define pre-command hooks, which attach arbitrary command
5194 scripts to any command. The commands in the hook will be executed
5195 prior to the user's command. You can also create a hook which will be
5196 executed whenever the program stops. See gdb.texinfo.
5200 We now deal with Cfront style name mangling, and can even extract type
5201 info from mangled symbols. GDB can automatically figure out which
5202 symbol mangling style your C++ compiler uses.
5204 Calling of methods and virtual functions has been improved as well.
5208 The crash that occured when debugging Sun Ansi-C compiled binaries is
5209 fixed. This was due to mishandling of the extra N_SO stabs output
5212 We also finally got Ultrix 4.2 running in house, and fixed core file
5213 support, with help from a dozen people on the net.
5215 John M. Farrell discovered that the reason that single-stepping was so
5216 slow on all of the Mips based platforms (primarily SGI and DEC) was
5217 that we were trying to demangle and lookup a symbol used for internal
5218 purposes on every instruction that was being stepped through. Changing
5219 the name of that symbol so that it couldn't be mistaken for a C++
5220 mangled symbol sped things up a great deal.
5222 Rich Pixley sped up symbol lookups in general by getting much smarter
5223 about when C++ symbol mangling is necessary. This should make symbol
5224 completion (TAB on the command line) much faster. It's not as fast as
5225 we'd like, but it's significantly faster than gdb-4.6.
5229 A new user controllable variable 'call_scratch_address' can
5230 specify the location of a scratch area to be used when GDB
5231 calls a function in the target. This is necessary because the
5232 usual method of putting the scratch area on the stack does not work
5233 in systems that have separate instruction and data spaces.
5235 We integrated changes to support the 29k UDI (Universal Debugger
5236 Interface), but discovered at the last minute that we didn't have all
5237 of the appropriate copyright paperwork. We are working with AMD to
5238 resolve this, and hope to have it available soon.
5242 We have sped up the remote serial line protocol, especially for targets
5243 with lots of registers. It now supports a new `expedited status' ('T')
5244 message which can be used in place of the existing 'S' status message.
5245 This allows the remote stub to send only the registers that GDB
5246 needs to make a quick decision about single-stepping or conditional
5247 breakpoints, eliminating the need to fetch the entire register set for
5248 each instruction being stepped through.
5250 The GDB remote serial protocol now implements a write-through cache for
5251 registers, only re-reading the registers if the target has run.
5253 There is also a new remote serial stub for SPARC processors. You can
5254 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5255 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5256 processor with a serial port.
5260 Configure.in files have become much easier to read and modify. A new
5261 `table driven' format makes it more obvious what configurations are
5262 supported, and what files each one uses.
5266 There is a new opcodes library which will eventually contain all of the
5267 disassembly routines and opcode tables. At present, it only contains
5268 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5269 disassembler (binutils/objdump) to share these routines.
5271 The libiberty library is now copylefted under the GNU Library General
5272 Public License. This allows more liberal use, and was done so libg++
5273 can use it. This makes no difference to GDB, since the Library License
5274 grants all the rights from the General Public License.
5278 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5279 reference to the stabs symbol info used by the debugger. It is (as far
5280 as we know) the only published document on this fascinating topic. We
5281 encourage you to read it, compare it to the stabs information on your
5282 system, and send improvements on the document in general (to
5283 bug-gdb@prep.ai.mit.edu).
5285 And, of course, many bugs have been fixed.
5288 *** Changes in GDB-4.6:
5290 * Better support for C++ function names
5292 GDB now accepts as input the "demangled form" of C++ overloaded function
5293 names and member function names, and can do command completion on such names
5294 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5295 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5296 Make use of command completion, it is your friend.
5298 GDB also now accepts a variety of C++ mangled symbol formats. They are
5299 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5300 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5301 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5302 for the list of formats.
5304 * G++ symbol mangling problem
5306 Recent versions of gcc have a bug in how they emit debugging information for
5307 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5308 directory) can be applied to gcc to fix the problem. Alternatively, if you
5309 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5310 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5311 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5314 * New 'maintenance' command
5316 All of the commands related to hacking GDB internals have been moved out of
5317 the main command set, and now live behind the 'maintenance' command. This
5318 can also be abbreviated as 'mt'. The following changes were made:
5320 dump-me -> maintenance dump-me
5321 info all-breakpoints -> maintenance info breakpoints
5322 printmsyms -> maintenance print msyms
5323 printobjfiles -> maintenance print objfiles
5324 printpsyms -> maintenance print psymbols
5325 printsyms -> maintenance print symbols
5327 The following commands are new:
5329 maintenance demangle Call internal GDB demangler routine to
5330 demangle a C++ link name and prints the result.
5331 maintenance print type Print a type chain for a given symbol
5333 * Change to .gdbinit file processing
5335 We now read the $HOME/.gdbinit file before processing the argv arguments
5336 (e.g. reading symbol files or core files). This allows global parameters to
5337 be set, which will apply during the symbol reading. The ./.gdbinit is still
5338 read after argv processing.
5340 * New hosts supported
5342 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5344 GNU/Linux support i386-unknown-linux or linux
5346 We are also including code to support the HP/PA running BSD and HPUX. This
5347 is almost guaranteed not to work, as we didn't have time to test or build it
5348 for this release. We are including it so that the more adventurous (or
5349 masochistic) of you can play with it. We also had major problems with the
5350 fact that the compiler that we got from HP doesn't support the -g option.
5353 * New targets supported
5355 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5357 * More smarts about finding #include files
5359 GDB now remembers the compilation directory for all include files, and for
5360 all files from which C is generated (like yacc and lex sources). This
5361 greatly improves GDB's ability to find yacc/lex sources, and include files,
5362 especially if you are debugging your program from a directory different from
5363 the one that contains your sources.
5365 We also fixed a bug which caused difficulty with listing and setting
5366 breakpoints in include files which contain C code. (In the past, you had to
5367 try twice in order to list an include file that you hadn't looked at before.)
5369 * Interesting infernals change
5371 GDB now deals with arbitrary numbers of sections, where the symbols for each
5372 section must be relocated relative to that section's landing place in the
5373 target's address space. This work was needed to support ELF with embedded
5374 stabs used by Solaris-2.0.
5376 * Bug fixes (of course!)
5378 There have been loads of fixes for the following things:
5379 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5380 i960, stabs, DOS(GO32), procfs, etc...
5382 See the ChangeLog for details.
5384 *** Changes in GDB-4.5:
5386 * New machines supported (host and target)
5388 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5390 SGI Irix-4.x mips-sgi-irix4 or iris4
5392 * New malloc package
5394 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5395 Mmalloc is capable of handling mutiple heaps of memory. It is also
5396 capable of saving a heap to a file, and then mapping it back in later.
5397 This can be used to greatly speedup the startup of GDB by using a
5398 pre-parsed symbol table which lives in a mmalloc managed heap. For
5399 more details, please read mmalloc/mmalloc.texi.
5403 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5404 'help info proc' for details.
5406 * MIPS ecoff symbol table format
5408 The code that reads MIPS symbol table format is now supported on all hosts.
5409 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5412 * File name changes for MS-DOS
5414 Many files in the config directories have been renamed to make it easier to
5415 support GDB on MS-DOSe systems (which have very restrictive file name
5416 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5417 environment) is close to working but has some remaining problems. Note
5418 that debugging of DOS programs is not supported, due to limitations
5419 in the ``operating system'', but it can be used to host cross-debugging.
5421 * Cross byte order fixes
5423 Many fixes have been made to support cross debugging of Sparc and MIPS
5424 targets from hosts whose byte order differs.
5426 * New -mapped and -readnow options
5428 If memory-mapped files are available on your system through the 'mmap'
5429 system call, you can use the -mapped option on the `file' or
5430 `symbol-file' commands to cause GDB to write the symbols from your
5431 program into a reusable file. If the program you are debugging is
5432 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5433 Future GDB debugging sessions will notice the presence of this file,
5434 and will quickly map in symbol information from it, rather than reading
5435 the symbol table from the executable program. Using the '-mapped'
5436 option in a GDB `file' or `symbol-file' command has the same effect as
5437 starting GDB with the '-mapped' command-line option.
5439 You can cause GDB to read the entire symbol table immediately by using
5440 the '-readnow' option with any of the commands that load symbol table
5441 information (or on the GDB command line). This makes the command
5442 slower, but makes future operations faster.
5444 The -mapped and -readnow options are typically combined in order to
5445 build a `fred.syms' file that contains complete symbol information.
5446 A simple GDB invocation to do nothing but build a `.syms' file for future
5449 gdb -batch -nx -mapped -readnow programname
5451 The `.syms' file is specific to the host machine on which GDB is run.
5452 It holds an exact image of GDB's internal symbol table. It cannot be
5453 shared across multiple host platforms.
5455 * longjmp() handling
5457 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5458 siglongjmp() without losing control. This feature has not yet been ported to
5459 all systems. It currently works on many 386 platforms, all MIPS-based
5460 platforms (SGI, DECstation, etc), and Sun3/4.
5464 Preliminary work has been put in to support the new Solaris OS from Sun. At
5465 this time, it can control and debug processes, but it is not capable of
5470 As always, many many bug fixes. The major areas were with g++, and mipsread.
5471 People using the MIPS-based platforms should experience fewer mysterious
5472 crashes and trashed symbol tables.
5474 *** Changes in GDB-4.4:
5476 * New machines supported (host and target)
5478 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5480 BSD Reno on Vax vax-dec-bsd
5481 Ultrix on Vax vax-dec-ultrix
5483 * New machines supported (target)
5485 AMD 29000 embedded, using EBMON a29k-none-none
5489 GDB continues to improve its handling of C++. `References' work better.
5490 The demangler has also been improved, and now deals with symbols mangled as
5491 per the Annotated C++ Reference Guide.
5493 GDB also now handles `stabs' symbol information embedded in MIPS
5494 `ecoff' symbol tables. Since the ecoff format was not easily
5495 extensible to handle new languages such as C++, this appeared to be a
5496 good way to put C++ debugging info into MIPS binaries. This option
5497 will be supported in the GNU C compiler, version 2, when it is
5500 * New features for SVR4
5502 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5503 shared libraries. Debugging dynamically linked programs should present
5504 only minor differences from debugging statically linked programs.
5506 The `info proc' command will print out information about any process
5507 on an SVR4 system (including the one you are debugging). At the moment,
5508 it prints the address mappings of the process.
5510 If you bring up GDB on another SVR4 system, please send mail to
5511 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5513 * Better dynamic linking support in SunOS
5515 Reading symbols from shared libraries which contain debugging symbols
5516 now works properly. However, there remain issues such as automatic
5517 skipping of `transfer vector' code during function calls, which
5518 make it harder to debug code in a shared library, than to debug the
5519 same code linked statically.
5523 GDB is now using the latest `getopt' routines from the FSF. This
5524 version accepts the -- prefix for options with long names. GDB will
5525 continue to accept the old forms (-option and +option) as well.
5526 Various single letter abbreviations for options have been explicity
5527 added to the option table so that they won't get overshadowed in the
5528 future by other options that begin with the same letter.
5532 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5533 Many assorted bugs have been handled. Many more remain to be handled.
5534 See the various ChangeLog files (primarily in gdb and bfd) for details.
5537 *** Changes in GDB-4.3:
5539 * New machines supported (host and target)
5541 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5542 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5543 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5545 * Almost SCO Unix support
5547 We had hoped to support:
5548 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5549 (except for core file support), but we discovered very late in the release
5550 that it has problems with process groups that render gdb unusable. Sorry
5551 about that. I encourage people to fix it and post the fixes.
5553 * Preliminary ELF and DWARF support
5555 GDB can read ELF object files on System V Release 4, and can handle
5556 debugging records for C, in DWARF format, in ELF files. This support
5557 is preliminary. If you bring up GDB on another SVR4 system, please
5558 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5563 GDB now uses the latest `readline' library. One user-visible change
5564 is that two tabs will list possible command completions, which previously
5565 required typing M-? (meta-question mark, or ESC ?).
5569 The `stepi' bug that many of you noticed has been squashed.
5570 Many bugs in C++ have been handled. Many more remain to be handled.
5571 See the various ChangeLog files (primarily in gdb and bfd) for details.
5573 * State of the MIPS world (in case you wondered):
5575 GDB can understand the symbol tables emitted by the compilers
5576 supplied by most vendors of MIPS-based machines, including DEC. These
5577 symbol tables are in a format that essentially nobody else uses.
5579 Some versions of gcc come with an assembler post-processor called
5580 mips-tfile. This program is required if you want to do source-level
5581 debugging of gcc-compiled programs. I believe FSF does not ship
5582 mips-tfile with gcc version 1, but it will eventually come with gcc
5585 Debugging of g++ output remains a problem. g++ version 1.xx does not
5586 really support it at all. (If you're lucky, you should be able to get
5587 line numbers and stack traces to work, but no parameters or local
5588 variables.) With some work it should be possible to improve the
5591 When gcc version 2 is released, you will have somewhat better luck.
5592 However, even then you will get confusing results for inheritance and
5595 We will eventually provide full debugging of g++ output on
5596 DECstations. This will probably involve some kind of stabs-in-ecoff
5597 encapulation, but the details have not been worked out yet.
5600 *** Changes in GDB-4.2:
5602 * Improved configuration
5604 Only one copy of `configure' exists now, and it is not self-modifying.
5605 Porting BFD is simpler.
5609 The `step' and `next' commands now only stop at the first instruction
5610 of a source line. This prevents the multiple stops that used to occur
5611 in switch statements, for-loops, etc. `Step' continues to stop if a
5612 function that has debugging information is called within the line.
5616 Lots of small bugs fixed. More remain.
5618 * New host supported (not target)
5620 Intel 386 PC clone running Mach i386-none-mach
5623 *** Changes in GDB-4.1:
5625 * Multiple source language support
5627 GDB now has internal scaffolding to handle several source languages.
5628 It determines the type of each source file from its filename extension,
5629 and will switch expression parsing and number formatting to match the
5630 language of the function in the currently selected stack frame.
5631 You can also specifically set the language to be used, with
5632 `set language c' or `set language modula-2'.
5636 GDB now has preliminary support for the GNU Modula-2 compiler,
5637 currently under development at the State University of New York at
5638 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5639 continue through the fall of 1991 and into 1992.
5641 Other Modula-2 compilers are currently not supported, and attempting to
5642 debug programs compiled with them will likely result in an error as the
5643 symbol table is read. Feel free to work on it, though!
5645 There are hooks in GDB for strict type checking and range checking,
5646 in the `Modula-2 philosophy', but they do not currently work.
5650 GDB can now write to executable and core files (e.g. patch
5651 a variable's value). You must turn this switch on, specify
5652 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5653 by assigning a new value to a variable. Modifications take
5656 * Automatic SunOS shared library reading
5658 When you run your program, GDB automatically determines where its
5659 shared libraries (if any) have been loaded, and reads their symbols.
5660 The `share' command is no longer needed. This also works when
5661 examining core files.
5665 You can specify the number of lines that the `list' command shows.
5668 * New machines supported (host and target)
5670 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5671 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5672 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5674 * New hosts supported (not targets)
5676 IBM RT/PC: romp-ibm-aix or rtpc
5678 * New targets supported (not hosts)
5680 AMD 29000 embedded with COFF a29k-none-coff
5681 AMD 29000 embedded with a.out a29k-none-aout
5682 Ultracomputer remote kernel debug a29k-nyu-kern
5684 * New remote interfaces
5690 *** Changes in GDB-4.0:
5694 Wide output is wrapped at good places to make the output more readable.
5696 Gdb now supports cross-debugging from a host machine of one type to a
5697 target machine of another type. Communication with the target system
5698 is over serial lines. The ``target'' command handles connecting to the
5699 remote system; the ``load'' command will download a program into the
5700 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5701 also supports debugging of realtime processes running under VxWorks,
5702 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5703 stub on the target system.
5705 New CPUs supported include the AMD 29000 and Intel 960.
5707 GDB now reads object files and symbol tables via a ``binary file''
5708 library, which allows a single copy of GDB to debug programs of multiple
5709 object file types such as a.out and coff.
5711 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5712 refcard.dvi and refcard.ps are available to format it).
5715 * Control-Variable user interface simplified
5717 All variables that control the operation of the debugger can be set
5718 by the ``set'' command, and displayed by the ``show'' command.
5720 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5721 ``Show prompt'' produces the response:
5722 Gdb's prompt is new-gdb=>.
5724 What follows are the NEW set commands. The command ``help set'' will
5725 print a complete list of old and new set commands. ``help set FOO''
5726 will give a longer description of the variable FOO. ``show'' will show
5727 all of the variable descriptions and their current settings.
5729 confirm on/off: Enables warning questions for operations that are
5730 hard to recover from, e.g. rerunning the program while
5731 it is already running. Default is ON.
5733 editing on/off: Enables EMACS style command line editing
5734 of input. Previous lines can be recalled with
5735 control-P, the current line can be edited with control-B,
5736 you can search for commands with control-R, etc.
5739 history filename NAME: NAME is where the gdb command history
5740 will be stored. The default is .gdb_history,
5741 or the value of the environment variable
5744 history size N: The size, in commands, of the command history. The
5745 default is 256, or the value of the environment variable
5748 history save on/off: If this value is set to ON, the history file will
5749 be saved after exiting gdb. If set to OFF, the
5750 file will not be saved. The default is OFF.
5752 history expansion on/off: If this value is set to ON, then csh-like
5753 history expansion will be performed on
5754 command line input. The default is OFF.
5756 radix N: Sets the default radix for input and output. It can be set
5757 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5758 in the current radix, so "set radix 10" is always a no-op.
5760 height N: This integer value is the number of lines on a page. Default
5761 is 24, the current `stty rows'' setting, or the ``li#''
5762 setting from the termcap entry matching the environment
5765 width N: This integer value is the number of characters on a line.
5766 Default is 80, the current `stty cols'' setting, or the ``co#''
5767 setting from the termcap entry matching the environment
5770 Note: ``set screensize'' is obsolete. Use ``set height'' and
5771 ``set width'' instead.
5773 print address on/off: Print memory addresses in various command displays,
5774 such as stack traces and structure values. Gdb looks
5775 more ``symbolic'' if you turn this off; it looks more
5776 ``machine level'' with it on. Default is ON.
5778 print array on/off: Prettyprint arrays. New convenient format! Default
5781 print demangle on/off: Print C++ symbols in "source" form if on,
5784 print asm-demangle on/off: Same, for assembler level printouts
5787 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5790 * Support for Epoch Environment.
5792 The epoch environment is a version of Emacs v18 with windowing. One
5793 new command, ``inspect'', is identical to ``print'', except that if you
5794 are running in the epoch environment, the value is printed in its own
5798 * Support for Shared Libraries
5800 GDB can now debug programs and core files that use SunOS shared libraries.
5801 Symbols from a shared library cannot be referenced
5802 before the shared library has been linked with the program (this
5803 happens after you type ``run'' and before the function main() is entered).
5804 At any time after this linking (including when examining core files
5805 from dynamically linked programs), gdb reads the symbols from each
5806 shared library when you type the ``sharedlibrary'' command.
5807 It can be abbreviated ``share''.
5809 sharedlibrary REGEXP: Load shared object library symbols for files
5810 matching a unix regular expression. No argument
5811 indicates to load symbols for all shared libraries.
5813 info sharedlibrary: Status of loaded shared libraries.
5818 A watchpoint stops execution of a program whenever the value of an
5819 expression changes. Checking for this slows down execution
5820 tremendously whenever you are in the scope of the expression, but is
5821 quite useful for catching tough ``bit-spreader'' or pointer misuse
5822 problems. Some machines such as the 386 have hardware for doing this
5823 more quickly, and future versions of gdb will use this hardware.
5825 watch EXP: Set a watchpoint (breakpoint) for an expression.
5827 info watchpoints: Information about your watchpoints.
5829 delete N: Deletes watchpoint number N (same as breakpoints).
5830 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5831 enable N: Re-enables watchpoint number N (same as breakpoints).
5834 * C++ multiple inheritance
5836 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5839 * C++ exception handling
5841 Gdb now supports limited C++ exception handling. Besides the existing
5842 ability to breakpoint on an exception handler, gdb can breakpoint on
5843 the raising of an exception (before the stack is peeled back to the
5846 catch FOO: If there is a FOO exception handler in the dynamic scope,
5847 set a breakpoint to catch exceptions which may be raised there.
5848 Multiple exceptions (``catch foo bar baz'') may be caught.
5850 info catch: Lists all exceptions which may be caught in the
5851 current stack frame.
5854 * Minor command changes
5856 The command ``call func (arg, arg, ...)'' now acts like the print
5857 command, except it does not print or save a value if the function's result
5858 is void. This is similar to dbx usage.
5860 The ``up'' and ``down'' commands now always print the frame they end up
5861 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5862 frames without printing.
5864 * New directory command
5866 'dir' now adds directories to the FRONT of the source search path.
5867 The path starts off empty. Source files that contain debug information
5868 about the directory in which they were compiled can be found even
5869 with an empty path; Sun CC and GCC include this information. If GDB can't
5870 find your source file in the current directory, type "dir .".
5872 * Configuring GDB for compilation
5874 For normal use, type ``./configure host''. See README or gdb.texinfo
5877 GDB now handles cross debugging. If you are remotely debugging between
5878 two different machines, type ``./configure host -target=targ''.
5879 Host is the machine where GDB will run; targ is the machine
5880 where the program that you are debugging will run.