1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.10
6 * Record btrace now supports non-stop mode.
8 * Support for tracepoints on aarch64-linux was added in GDBserver.
10 * The 'record instruction-history' command now indicates speculative execution
11 when using the Intel Processor Trace recording format.
13 * GDB now allows users to specify explicit locations, bypassing
14 the linespec parser. This feature is also available to GDB/MI
17 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
18 GDB now is able to debug both AArch64 applications and ARM applications
21 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
22 including JIT compiling fast tracepoint's conditional expression bytecode
25 * GDB now supports displaced stepping on AArch64 GNU/Linux.
27 * "info threads", "info inferiors", "info display", "info checkpoints"
28 and "maint info program-spaces" now list the corresponding items in
29 ascending ID order, for consistency with all other "info" commands.
31 * In Ada, the overloads selection menu has been enhanced to display the
32 parameter types and the return types for the matching overloaded subprograms.
36 maint set target-non-stop (on|off|auto)
37 maint show target-non-stop
38 Control whether GDB targets always operate in non-stop mode even if
39 "set non-stop" is "off". The default is "auto", meaning non-stop
40 mode is enabled if supported by the target.
43 maint show bfd-sharing
44 Control the reuse of bfd objects.
48 Control display of debugging info regarding bfd caching.
50 set remote multiprocess-extensions-packet
51 show remote multiprocess-extensions-packet
52 Set/show the use of the remote protocol multiprocess extensions.
54 set remote thread-events
55 show remote thread-events
56 Set/show the use of thread create/exit events.
58 set ada print-signatures on|off
59 show ada print-signatures"
60 Control whether parameter types and return types are displayed in overloads
61 selection menus. It is activaled (@code{on}) by default.
63 * The "disassemble" command accepts a new modifier: /s.
64 It prints mixed source+disassembly like /m with two differences:
65 - disassembled instructions are now printed in program order, and
66 - and source for all relevant files is now printed.
67 The "/m" option is now considered deprecated: its "source-centric"
68 output hasn't proved useful in practice.
70 * The "record instruction-history" command accepts a new modifier: /s.
71 It behaves exactly like /m and prints mixed source+disassembly.
73 * The "set scheduler-locking" command supports a new mode "replay".
74 It behaves like "off" in record mode and like "on" in replay mode.
76 * Support for various ROM monitors has been removed:
78 target dbug dBUG ROM monitor for Motorola ColdFire
79 target picobug Motorola picobug monitor
80 target dink32 DINK32 ROM monitor for PowerPC
81 target m32r Renesas M32R/D ROM monitor
82 target mon2000 mon2000 ROM monitor
83 target ppcbug PPCBUG ROM monitor for PowerPC
85 * Support for reading/writing memory and extracting values on architectures
86 whose memory is addressable in units of any integral multiple of 8 bits.
91 Indicates that an exec system call was executed.
93 exec-events feature in qSupported
94 The qSupported packet allows GDB to request support for exec
95 events using the new 'gdbfeature' exec-event, and the qSupported
96 response can contain the corresponding 'stubfeature'. Set and
97 show commands can be used to display whether these features are enabled.
100 Equivalent to interrupting with the ^C character, but works in
103 thread created stop reason (T05 create:...)
104 Indicates that the thread was just created and is stopped at entry.
106 thread exit stop reply (w exitcode;tid)
107 Indicates that the thread has terminated.
110 Enables/disables thread create and exit event reporting. For
111 example, this is used in non-stop mode when GDB stops a set of
112 threads and synchronously waits for the their corresponding stop
113 replies. Without exit events, if one of the threads exits, GDB
114 would hang forever not knowing that it should no longer expect a
115 stop for that same thread.
119 Indicates that there are no resumed threads left in the target (all
120 threads are stopped). The remote stub reports support for this stop
121 reply to GDB's qSupported query.
123 QCatchSyscalls:1 [;SYSNO]...
125 Enable ("QCatchSyscalls:1") or disable ("QCatchSyscalls:0")
126 catching syscalls from the inferior process.
128 syscall_entry stop reason
129 Indicates that a syscall was just called.
131 syscall_return stop reason
132 Indicates that a syscall just returned.
134 QCatchSyscalls:1 in qSupported
135 The qSupported packet may now include QCatchSyscalls:1 in the reply
136 to indicate support for catching syscalls.
138 * Extended-remote exec events
140 ** GDB now has support for exec events on extended-remote Linux targets.
141 For such targets with Linux kernels 2.5.46 and later, this enables
142 follow-exec-mode and exec catchpoints.
144 set remote exec-event-feature-packet
145 show remote exec-event-feature-packet
146 Set/show the use of the remote exec event feature.
148 * Thread names in remote protocol
150 The reply to qXfer:threads:read may now include a name attribute for each
153 * Target remote mode fork and exec events
155 ** GDB now has support for fork and exec events on target remote mode
156 Linux targets. For such targets with Linux kernels 2.5.46 and later,
157 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
158 fork and exec catchpoints.
160 * Remote syscall events
162 ** GDB now has support for catch syscall on remote Linux targets,
163 currently enabled on x86/x86_64 architectures.
165 set remote catch-syscall-packet
166 show remote catch-syscall-packet
167 Set/show the use of the remote catch syscall feature.
171 ** The -var-set-format command now accepts the zero-hexadecimal
172 format. It outputs data in hexadecimal format with zero-padding on the
175 *** Changes in GDB 7.10
177 * Support for process record-replay and reverse debugging on aarch64*-linux*
178 targets has been added. GDB now supports recording of A64 instruction set
179 including advance SIMD instructions.
181 * Support for Sun's version of the "stabs" debug file format has been removed.
183 * GDB now honors the content of the file /proc/PID/coredump_filter
184 (PID is the process ID) on GNU/Linux systems. This file can be used
185 to specify the types of memory mappings that will be included in a
186 corefile. For more information, please refer to the manual page of
187 "core(5)". GDB also has a new command: "set use-coredump-filter
188 on|off". It allows to set whether GDB will read the content of the
189 /proc/PID/coredump_filter file when generating a corefile.
191 * The "info os" command on GNU/Linux can now display information on
193 "info os cpus" Listing of all cpus/cores on the system
195 * GDB has two new commands: "set serial parity odd|even|none" and
196 "show serial parity". These allows to set or show parity for the
199 * The "info source" command now displays the producer string if it was
200 present in the debug info. This typically includes the compiler version
201 and may include things like its command line arguments.
203 * The "info dll", an alias of the "info sharedlibrary" command,
204 is now available on all platforms.
206 * Directory names supplied to the "set sysroot" commands may be
207 prefixed with "target:" to tell GDB to access shared libraries from
208 the target system, be it local or remote. This replaces the prefix
209 "remote:". The default sysroot has been changed from "" to
210 "target:". "remote:" is automatically converted to "target:" for
211 backward compatibility.
213 * The system root specified by "set sysroot" will be prepended to the
214 filename of the main executable (if reported to GDB as absolute by
215 the operating system) when starting processes remotely, and when
216 attaching to already-running local or remote processes.
218 * GDB now supports automatic location and retrieval of executable
219 files from remote targets. Remote debugging can now be initiated
220 using only a "target remote" or "target extended-remote" command
221 (no "set sysroot" or "file" commands are required). See "New remote
224 * The "dump" command now supports verilog hex format.
226 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
228 * On GNU/Linux, GDB and gdbserver are now able to access executable
229 and shared library files without a "set sysroot" command when
230 attaching to processes running in different mount namespaces from
231 the debugger. This makes it possible to attach to processes in
232 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
233 See "New remote packets" below.
235 * The "tui reg" command now provides completion for all of the
236 available register groups, including target specific groups.
238 * The HISTSIZE environment variable is no longer read when determining
239 the size of GDB's command history. GDB now instead reads the dedicated
240 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
241 disables truncation of command history. Non-numeric values of GDBHISTSIZE
246 ** Memory ports can now be unbuffered.
250 ** gdb.Objfile objects have a new attribute "username",
251 which is the name of the objfile as specified by the user,
252 without, for example, resolving symlinks.
253 ** You can now write frame unwinders in Python.
254 ** gdb.Type objects have a new method "optimized_out",
255 returning optimized out gdb.Value instance of this type.
256 ** gdb.Value objects have new methods "reference_value" and
257 "const_value" which return a reference to the value and a
258 "const" version of the value respectively.
262 maint print symbol-cache
263 Print the contents of the symbol cache.
265 maint print symbol-cache-statistics
266 Print statistics of symbol cache usage.
268 maint flush-symbol-cache
269 Flush the contents of the symbol cache.
273 Start branch trace recording using Branch Trace Store (BTS) format.
276 Evaluate expression by using the compiler and print result.
280 Explicit commands for enabling and disabling tui mode.
283 set mpx bound on i386 and amd64
284 Support for bound table investigation on Intel MPX enabled applications.
288 Start branch trace recording using Intel Processor Trace format.
291 Print information about branch tracing internals.
293 maint btrace packet-history
294 Print the raw branch tracing data.
296 maint btrace clear-packet-history
297 Discard the stored raw branch tracing data.
300 Discard all branch tracing data. It will be fetched and processed
301 anew by the next "record" command.
306 Renamed from "set debug dwarf2-die".
308 Renamed from "show debug dwarf2-die".
311 Renamed from "set debug dwarf2-read".
312 show debug dwarf-read
313 Renamed from "show debug dwarf2-read".
315 maint set dwarf always-disassemble
316 Renamed from "maint set dwarf2 always-disassemble".
317 maint show dwarf always-disassemble
318 Renamed from "maint show dwarf2 always-disassemble".
320 maint set dwarf max-cache-age
321 Renamed from "maint set dwarf2 max-cache-age".
322 maint show dwarf max-cache-age
323 Renamed from "maint show dwarf2 max-cache-age".
326 show debug dwarf-line
327 Control display of debugging info regarding DWARF line processing.
331 Set the maximum number of candidates to be considered during
332 completion. The default value is 200. This limit allows GDB
333 to avoid generating large completion lists, the computation of
334 which can cause the debugger to become temporarily unresponsive.
336 set history remove-duplicates
337 show history remove-duplicates
338 Control the removal of duplicate history entries.
340 maint set symbol-cache-size
341 maint show symbol-cache-size
342 Control the size of the symbol cache.
344 set|show record btrace bts buffer-size
345 Set and show the size of the ring buffer used for branch tracing in
347 The obtained size may differ from the requested size. Use "info
348 record" to see the obtained buffer size.
350 set debug linux-namespaces
351 show debug linux-namespaces
352 Control display of debugging info regarding Linux namespaces.
354 set|show record btrace pt buffer-size
355 Set and show the size of the ring buffer used for branch tracing in
356 Intel Processor Trace format.
357 The obtained size may differ from the requested size. Use "info
358 record" to see the obtained buffer size.
360 maint set|show btrace pt skip-pad
361 Set and show whether PAD packets are skipped when computing the
364 * The command 'thread apply all' can now support new option '-ascending'
365 to call its specified command for all threads in ascending order.
367 * Python/Guile scripting
369 ** GDB now supports auto-loading of Python/Guile scripts contained in the
370 special section named `.debug_gdb_scripts'.
374 qXfer:btrace-conf:read
375 Return the branch trace configuration for the current thread.
377 Qbtrace-conf:bts:size
378 Set the requested ring buffer size for branch tracing in BTS format.
381 Enable Intel Procesor Trace-based branch tracing for the current
382 process. The remote stub reports support for this packet to GDB's
386 Set the requested ring buffer size for branch tracing in Intel Processor
390 Indicates a memory breakpoint instruction was executed, irrespective
391 of whether it was GDB that planted the breakpoint or the breakpoint
392 is hardcoded in the program. This is required for correct non-stop
396 Indicates the target stopped for a hardware breakpoint. This is
397 required for correct non-stop mode operation.
400 Return information about files on the remote system.
403 Return the full absolute name of the file that was executed to
404 create a process running on the remote system.
407 Select the filesystem on which vFile: operations with filename
408 arguments will operate. This is required for GDB to be able to
409 access files on remote targets where the remote stub does not
410 share a common filesystem with the inferior(s).
413 Indicates that a fork system call was executed.
416 Indicates that a vfork system call was executed.
418 vforkdone stop reason
419 Indicates that a vfork child of the specified process has executed
420 an exec or exit, allowing the vfork parent to resume execution.
422 fork-events and vfork-events features in qSupported
423 The qSupported packet allows GDB to request support for fork and
424 vfork events using new 'gdbfeatures' fork-events and vfork-events,
425 and the qSupported response can contain the corresponding
426 'stubfeatures'. Set and show commands can be used to display
427 whether these features are enabled.
429 * Extended-remote fork events
431 ** GDB now has support for fork events on extended-remote Linux
432 targets. For targets with Linux kernels 2.5.60 and later, this
433 enables follow-fork-mode and detach-on-fork for both fork and
434 vfork, as well as fork and vfork catchpoints.
436 * The info record command now shows the recording format and the
437 branch tracing configuration for the current thread when using
438 the btrace record target.
439 For the BTS format, it shows the ring buffer size.
441 * GDB now has support for DTrace USDT (Userland Static Defined
442 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
444 * GDB now supports access to vector registers on S/390 GNU/Linux
447 * Removed command line options
449 -xdb HP-UX XDB compatibility mode.
451 * Removed targets and native configurations
453 HP/PA running HP-UX hppa*-*-hpux*
454 Itanium running HP-UX ia64-*-hpux*
456 * New configure options
459 This configure option allows the user to build GDB with support for
460 Intel Processor Trace (default: auto). This requires libipt.
462 --with-libipt-prefix=PATH
463 Specify the path to the version of libipt that GDB should use.
464 $PATH/include should contain the intel-pt.h header and
465 $PATH/lib should contain the libipt.so library.
467 *** Changes in GDB 7.9.1
471 ** Xmethods can now specify a result type.
473 *** Changes in GDB 7.9
475 * GDB now supports hardware watchpoints on x86 GNU Hurd.
479 ** You can now access frame registers from Python scripts.
480 ** New attribute 'producer' for gdb.Symtab objects.
481 ** gdb.Objfile objects have a new attribute "progspace",
482 which is the gdb.Progspace object of the containing program space.
483 ** gdb.Objfile objects have a new attribute "owner".
484 ** gdb.Objfile objects have a new attribute "build_id",
485 which is the build ID generated when the file was built.
486 ** gdb.Objfile objects have a new method "add_separate_debug_file".
487 ** A new event "gdb.clear_objfiles" has been added, triggered when
488 selecting a new file to debug.
489 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
490 ** New function gdb.lookup_objfile.
492 New events which are triggered when GDB modifies the state of the
495 ** gdb.events.inferior_call_pre: Function call is about to be made.
496 ** gdb.events.inferior_call_post: Function call has just been made.
497 ** gdb.events.memory_changed: A memory location has been altered.
498 ** gdb.events.register_changed: A register has been altered.
500 * New Python-based convenience functions:
502 ** $_caller_is(name [, number_of_frames])
503 ** $_caller_matches(regexp [, number_of_frames])
504 ** $_any_caller_is(name [, number_of_frames])
505 ** $_any_caller_matches(regexp [, number_of_frames])
507 * GDB now supports the compilation and injection of source code into
508 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
509 to compile the source code to object code, and if successful, inject
510 and execute that code within the current context of the inferior.
511 Currently the C language is supported. The commands used to
512 interface with this new feature are:
514 compile code [-raw|-r] [--] [source code]
515 compile file [-raw|-r] filename
519 demangle [-l language] [--] name
520 Demangle "name" in the specified language, or the current language
521 if elided. This command is renamed from the "maint demangle" command.
522 The latter is kept as a no-op to avoid "maint demangle" being interpreted
523 as "maint demangler-warning".
525 queue-signal signal-name-or-number
526 Queue a signal to be delivered to the thread when it is resumed.
528 add-auto-load-scripts-directory directory
529 Add entries to the list of directories from which to load auto-loaded
532 maint print user-registers
533 List all currently available "user" registers.
535 compile code [-r|-raw] [--] [source code]
536 Compile, inject, and execute in the inferior the executable object
537 code produced by compiling the provided source code.
539 compile file [-r|-raw] filename
540 Compile and inject into the inferior the executable object code
541 produced by compiling the source code stored in the filename
544 * On resume, GDB now always passes the signal the program had stopped
545 for to the thread the signal was sent to, even if the user changed
546 threads before resuming. Previously GDB would often (but not
547 always) deliver the signal to the thread that happens to be current
550 * Conversely, the "signal" command now consistently delivers the
551 requested signal to the current thread. GDB now asks for
552 confirmation if the program had stopped for a signal and the user
553 switched threads meanwhile.
555 * "breakpoint always-inserted" modes "off" and "auto" merged.
557 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
558 won't remove breakpoints from the target until all threads stop,
559 even in non-stop mode. The "auto" mode has been removed, and "off"
560 is now the default mode.
564 set debug symbol-lookup
565 show debug symbol-lookup
566 Control display of debugging info regarding symbol lookup.
570 ** The -list-thread-groups command outputs an exit-code field for
571 inferiors that have exited.
575 MIPS SDE mips*-sde*-elf*
579 Support for these obsolete configurations has been removed.
581 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
582 SGI Irix-5.x mips-*-irix5*
583 SGI Irix-6.x mips-*-irix6*
584 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
585 VAX running Ultrix vax-*-ultrix*
587 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
588 and "assf"), have been removed. Use the "sharedlibrary" command, or
589 its alias "share", instead.
591 *** Changes in GDB 7.8
593 * New command line options
596 This is an alias for the --data-directory option.
598 * GDB supports printing and modifying of variable length automatic arrays
599 as specified in ISO C99.
601 * The ARM simulator now supports instruction level tracing
602 with or without disassembly.
606 GDB now has support for scripting using Guile. Whether this is
607 available is determined at configure time.
608 Guile version 2.0 or greater is required.
609 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
611 * New commands (for set/show, see "New options" below)
615 Invoke CODE by passing it to the Guile interpreter.
619 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
621 info auto-load guile-scripts [regexp]
622 Print the list of automatically loaded Guile scripts.
624 * The source command is now capable of sourcing Guile scripts.
625 This feature is dependent on the debugger being built with Guile support.
629 set print symbol-loading (off|brief|full)
630 show print symbol-loading
631 Control whether to print informational messages when loading symbol
632 information for a file. The default is "full", but when debugging
633 programs with large numbers of shared libraries the amount of output
636 set guile print-stack (none|message|full)
637 show guile print-stack
638 Show a stack trace when an error is encountered in a Guile script.
640 set auto-load guile-scripts (on|off)
641 show auto-load guile-scripts
642 Control auto-loading of Guile script files.
644 maint ada set ignore-descriptive-types (on|off)
645 maint ada show ignore-descriptive-types
646 Control whether the debugger should ignore descriptive types in Ada
647 programs. The default is not to ignore the descriptive types. See
648 the user manual for more details on descriptive types and the intended
649 usage of this option.
651 set auto-connect-native-target
653 Control whether GDB is allowed to automatically connect to the
654 native target for the run, attach, etc. commands when not connected
655 to any target yet. See also "target native" below.
657 set record btrace replay-memory-access (read-only|read-write)
658 show record btrace replay-memory-access
659 Control what memory accesses are allowed during replay.
661 maint set target-async (on|off)
662 maint show target-async
663 This controls whether GDB targets operate in synchronous or
664 asynchronous mode. Normally the default is asynchronous, if it is
665 available; but this can be changed to more easily debug problems
666 occurring only in synchronous mode.
668 set mi-async (on|off)
670 Control whether MI asynchronous mode is preferred. This supersedes
671 "set target-async" of previous GDB versions.
673 * "set target-async" is deprecated as a CLI option and is now an alias
674 for "set mi-async" (only puts MI into async mode).
676 * Background execution commands (e.g., "c&", "s&", etc.) are now
677 possible ``out of the box'' if the target supports them. Previously
678 the user would need to explicitly enable the possibility with the
679 "set target-async on" command.
681 * New features in the GDB remote stub, GDBserver
683 ** New option --debug-format=option1[,option2,...] allows one to add
684 additional text to each output. At present only timestamps
685 are supported: --debug-format=timestamps.
686 Timestamps can also be turned on with the
687 "monitor set debug-format timestamps" command from GDB.
689 * The 'record instruction-history' command now starts counting instructions
690 at one. This also affects the instruction ranges reported by the
691 'record function-call-history' command when given the /i modifier.
693 * The command 'record function-call-history' supports a new modifier '/c' to
694 indent the function names based on their call stack depth.
695 The fields for the '/i' and '/l' modifier have been reordered.
696 The source line range is now prefixed with 'at'.
697 The instruction range is now prefixed with 'inst'.
698 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
699 "record instruction-history" and "list" commands.
701 * The ranges given as arguments to the 'record function-call-history' and
702 'record instruction-history' commands are now inclusive.
704 * The btrace record target now supports the 'record goto' command.
705 For locations inside the execution trace, the back trace is computed
706 based on the information stored in the execution trace.
708 * The btrace record target supports limited reverse execution and replay.
709 The target does not record data and therefore does not allow reading
712 * The "catch syscall" command now works on s390*-linux* targets.
714 * The "compare-sections" command is no longer specific to target
715 remote. It now works with all targets.
717 * All native targets are now consistently called "native".
718 Consequently, the "target child", "target GNU", "target djgpp",
719 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
720 commands have been replaced with "target native". The QNX/NTO port
721 leaves the "procfs" target in place and adds a "native" target for
722 consistency with other ports. The impact on users should be minimal
723 as these commands previously either throwed an error, or were
724 no-ops. The target's name is visible in the output of the following
725 commands: "help target", "info target", "info files", "maint print
728 * The "target native" command now connects to the native target. This
729 can be used to launch native programs even when "set
730 auto-connect-native-target" is set to off.
732 * GDB now supports access to Intel MPX registers on GNU/Linux.
734 * Support for Intel AVX-512 registers on GNU/Linux.
735 Support displaying and modifying Intel AVX-512 registers
736 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
740 qXfer:btrace:read's annex
741 The qXfer:btrace:read packet supports a new annex 'delta' to read
742 branch trace incrementally.
746 ** Valid Python operations on gdb.Value objects representing
747 structs/classes invoke the corresponding overloaded operators if
749 ** New `Xmethods' feature in the Python API. Xmethods are
750 additional methods or replacements for existing methods of a C++
751 class. This feature is useful for those cases where a method
752 defined in C++ source code could be inlined or optimized out by
753 the compiler, making it unavailable to GDB.
756 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
758 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
759 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
760 its alias "share", instead.
762 * The commands "set remotebaud" and "show remotebaud" are no longer
763 supported. Use "set serial baud" and "show serial baud" (respectively)
768 ** A new option "-gdb-set mi-async" replaces "-gdb-set
769 target-async". The latter is left as a deprecated alias of the
770 former for backward compatibility. If the target supports it,
771 CLI background execution commands are now always possible by
772 default, independently of whether the frontend stated a
773 preference for asynchronous execution with "-gdb-set mi-async".
774 Previously "-gdb-set target-async off" affected both MI execution
775 commands and CLI execution commands.
777 *** Changes in GDB 7.7
779 * Improved support for process record-replay and reverse debugging on
780 arm*-linux* targets. Support for thumb32 and syscall instruction
781 recording has been added.
783 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
785 * GDB now supports Fission DWP file format version 2.
786 http://gcc.gnu.org/wiki/DebugFission
788 * New convenience function "$_isvoid", to check whether an expression
789 is void. A void expression is an expression where the type of the
790 result is "void". For example, some convenience variables may be
791 "void" when evaluated (e.g., "$_exitcode" before the execution of
792 the program being debugged; or an undefined convenience variable).
793 Another example, when calling a function whose return type is
796 * The "maintenance print objfiles" command now takes an optional regexp.
798 * The "catch syscall" command now works on arm*-linux* targets.
800 * GDB now consistently shows "<not saved>" when printing values of
801 registers the debug info indicates have not been saved in the frame
802 and there's nowhere to retrieve them from
803 (callee-saved/call-clobbered registers):
808 (gdb) info registers rax
811 Before, the former would print "<optimized out>", and the latter
812 "*value not available*".
814 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
819 ** Frame filters and frame decorators have been added.
820 ** Temporary breakpoints are now supported.
821 ** Line tables representation has been added.
822 ** New attribute 'parent_type' for gdb.Field objects.
823 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
824 ** New attribute 'name' for gdb.Type objects.
828 Nios II ELF nios2*-*-elf
829 Nios II GNU/Linux nios2*-*-linux
830 Texas Instruments MSP430 msp430*-*-elf
832 * Removed native configurations
834 Support for these a.out NetBSD and OpenBSD obsolete configurations has
835 been removed. ELF variants of these configurations are kept supported.
837 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
838 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
839 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
840 i[34567]86-*-openbsd3.[0-3]
841 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
842 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
843 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
847 Like "catch throw", but catches a re-thrown exception.
849 Renamed from old "maint check-symtabs".
851 Perform consistency checks on symtabs.
853 Expand symtabs matching an optional regexp.
856 Display the details of GDB configure-time options.
858 maint set|show per-command
859 maint set|show per-command space
860 maint set|show per-command time
861 maint set|show per-command symtab
862 Enable display of per-command gdb resource usage.
864 remove-symbol-file FILENAME
865 remove-symbol-file -a ADDRESS
866 Remove a symbol file added via add-symbol-file. The file to remove
867 can be identified by its filename or by an address that lies within
868 the boundaries of this symbol file in memory.
871 info exceptions REGEXP
872 Display the list of Ada exceptions defined in the program being
873 debugged. If provided, only the exceptions whose names match REGEXP
878 set debug symfile off|on
880 Control display of debugging info regarding reading symbol files and
881 symbol tables within those files
883 set print raw frame-arguments
884 show print raw frame-arguments
885 Set/show whether to print frame arguments in raw mode,
886 disregarding any defined pretty-printers.
888 set remote trace-status-packet
889 show remote trace-status-packet
890 Set/show the use of remote protocol qTStatus packet.
894 Control display of debugging messages related to Nios II targets.
898 Control whether target-assisted range stepping is enabled.
900 set startup-with-shell
901 show startup-with-shell
902 Specifies whether Unix child processes are started via a shell or
907 Use the target memory cache for accesses to the code segment. This
908 improves performance of remote debugging (particularly disassembly).
910 * You can now use a literal value 'unlimited' for options that
911 interpret 0 or -1 as meaning "unlimited". E.g., "set
912 trace-buffer-size unlimited" is now an alias for "set
913 trace-buffer-size -1" and "set height unlimited" is now an alias for
916 * The "set debug symtab-create" debugging option of GDB has been changed to
917 accept a verbosity level. 0 means "off", 1 provides basic debugging
918 output, and values of 2 or greater provides more verbose output.
920 * New command-line options
922 Display the details of GDB configure-time options.
924 * The command 'tsave' can now support new option '-ctf' to save trace
925 buffer in Common Trace Format.
927 * Newly installed $prefix/bin/gcore acts as a shell interface for the
930 * GDB now implements the the C++ 'typeid' operator.
932 * The new convenience variable $_exception holds the exception being
933 thrown or caught at an exception-related catchpoint.
935 * The exception-related catchpoints, like "catch throw", now accept a
936 regular expression which can be used to filter exceptions by type.
938 * The new convenience variable $_exitsignal is automatically set to
939 the terminating signal number when the program being debugged dies
940 due to an uncaught signal.
944 ** All MI commands now accept an optional "--language" option.
945 Support for this feature can be verified by using the "-list-features"
946 command, which should contain "language-option".
948 ** The new command -info-gdb-mi-command allows the user to determine
949 whether a GDB/MI command is supported or not.
951 ** The "^error" result record returned when trying to execute an undefined
952 GDB/MI command now provides a variable named "code" whose content is the
953 "undefined-command" error code. Support for this feature can be verified
954 by using the "-list-features" command, which should contain
955 "undefined-command-error-code".
957 ** The -trace-save MI command can optionally save trace buffer in Common
960 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
962 ** The command -data-list-register-values now accepts an optional
963 "--skip-unavailable" option. When used, only the available registers
966 ** The new command -trace-frame-collected dumps collected variables,
967 computed expressions, tvars, memory and registers in a traceframe.
969 ** The commands -stack-list-locals, -stack-list-arguments and
970 -stack-list-variables now accept an option "--skip-unavailable".
971 When used, only the available locals or arguments are displayed.
973 ** The -exec-run command now accepts an optional "--start" option.
974 When used, the command follows the same semantics as the "start"
975 command, stopping the program's execution at the start of its
976 main subprogram. Support for this feature can be verified using
977 the "-list-features" command, which should contain
978 "exec-run-start-option".
980 ** The new commands -catch-assert and -catch-exceptions insert
981 catchpoints stopping the program when Ada exceptions are raised.
983 ** The new command -info-ada-exceptions provides the equivalent of
984 the new "info exceptions" command.
986 * New system-wide configuration scripts
987 A GDB installation now provides scripts suitable for use as system-wide
988 configuration scripts for the following systems:
992 * GDB now supports target-assigned range stepping with remote targets.
993 This improves the performance of stepping source lines by reducing
994 the number of control packets from/to GDB. See "New remote packets"
997 * GDB now understands the element 'tvar' in the XML traceframe info.
998 It has the id of the collected trace state variables.
1000 * On S/390 targets that provide the transactional-execution feature,
1001 the program interruption transaction diagnostic block (TDB) is now
1002 represented as a number of additional "registers" in GDB.
1004 * New remote packets
1008 The vCont packet supports a new 'r' action, that tells the remote
1009 stub to step through an address range itself, without GDB
1010 involvemement at each single-step.
1012 qXfer:libraries-svr4:read's annex
1013 The previously unused annex of the qXfer:libraries-svr4:read packet
1014 is now used to support passing an argument list. The remote stub
1015 reports support for this argument list to GDB's qSupported query.
1016 The defined arguments are "start" and "prev", used to reduce work
1017 necessary for library list updating, resulting in significant
1020 * New features in the GDB remote stub, GDBserver
1022 ** GDBserver now supports target-assisted range stepping. Currently
1023 enabled on x86/x86_64 GNU/Linux targets.
1025 ** GDBserver now adds element 'tvar' in the XML in the reply to
1026 'qXfer:traceframe-info:read'. It has the id of the collected
1027 trace state variables.
1029 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1032 * New 'z' formatter for printing and examining memory, this displays the
1033 value as hexadecimal zero padded on the left to the size of the type.
1035 * GDB can now use Windows x64 unwinding data.
1037 * The "set remotebaud" command has been replaced by "set serial baud".
1038 Similarly, "show remotebaud" has been replaced by "show serial baud".
1039 The "set remotebaud" and "show remotebaud" commands are still available
1040 to provide backward compatibility with older versions of GDB.
1042 *** Changes in GDB 7.6
1044 * Target record has been renamed to record-full.
1045 Record/replay is now enabled with the "record full" command.
1046 This also affects settings that are associated with full record/replay
1047 that have been moved from "set/show record" to "set/show record full":
1049 set|show record full insn-number-max
1050 set|show record full stop-at-limit
1051 set|show record full memory-query
1053 * A new record target "record-btrace" has been added. The new target
1054 uses hardware support to record the control-flow of a process. It
1055 does not support replaying the execution, but it implements the
1056 below new commands for investigating the recorded execution log.
1057 This new recording method can be enabled using:
1061 The "record-btrace" target is only available on Intel Atom processors
1062 and requires a Linux kernel 2.6.32 or later.
1064 * Two new commands have been added for record/replay to give information
1065 about the recorded execution without having to replay the execution.
1066 The commands are only supported by "record btrace".
1068 record instruction-history prints the execution history at
1069 instruction granularity
1071 record function-call-history prints the execution history at
1072 function granularity
1074 * New native configurations
1076 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1077 FreeBSD/powerpc powerpc*-*-freebsd
1078 x86_64/Cygwin x86_64-*-cygwin*
1079 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1083 ARM AArch64 aarch64*-*-elf
1084 ARM AArch64 GNU/Linux aarch64*-*-linux
1085 Lynx 178 PowerPC powerpc-*-lynx*178
1086 x86_64/Cygwin x86_64-*-cygwin*
1087 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1089 * If the configured location of system.gdbinit file (as given by the
1090 --with-system-gdbinit option at configure time) is in the
1091 data-directory (as specified by --with-gdb-datadir at configure
1092 time) or in one of its subdirectories, then GDB will look for the
1093 system-wide init file in the directory specified by the
1094 --data-directory command-line option.
1096 * New command line options:
1098 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1099 other initialization files, unlike -nx which disables all of them.
1101 * Removed command line options
1103 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1106 * The 'ptype' and 'whatis' commands now accept an argument to control
1109 * 'info proc' now works on some core files.
1113 ** Vectors can be created with gdb.Type.vector.
1115 ** Python's atexit.register now works in GDB.
1117 ** Types can be pretty-printed via a Python API.
1119 ** Python 3 is now supported (in addition to Python 2.4 or later)
1121 ** New class gdb.Architecture exposes GDB's internal representation
1122 of architecture in the Python API.
1124 ** New method Frame.architecture returns the gdb.Architecture object
1125 corresponding to the frame's architecture.
1127 * New Python-based convenience functions:
1129 ** $_memeq(buf1, buf2, length)
1130 ** $_streq(str1, str2)
1132 ** $_regex(str, regex)
1134 * The 'cd' command now defaults to using '~' (the home directory) if not
1137 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1138 default for GCC since November 2000.
1140 * The command 'forward-search' can now be abbreviated as 'fo'.
1142 * The command 'info tracepoints' can now display 'installed on target'
1143 or 'not installed on target' for each non-pending location of tracepoint.
1145 * New configure options
1147 --enable-libmcheck/--disable-libmcheck
1148 By default, development versions are built with -lmcheck on hosts
1149 that support it, in order to help track memory corruption issues.
1150 Release versions, on the other hand, are built without -lmcheck
1151 by default. The --enable-libmcheck/--disable-libmcheck configure
1152 options allow the user to override that default.
1153 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1154 This configure option allows the user to build GDB with
1155 libbabeltrace using which GDB can read Common Trace Format data.
1157 * New commands (for set/show, see "New options" below)
1160 Catch signals. This is similar to "handle", but allows commands and
1161 conditions to be attached.
1164 List the BFDs known to GDB.
1166 python-interactive [command]
1168 Start a Python interactive prompt, or evaluate the optional command
1169 and print the result of expressions.
1172 "py" is a new alias for "python".
1174 enable type-printer [name]...
1175 disable type-printer [name]...
1176 Enable or disable type printers.
1180 ** For the Renesas Super-H architecture, the "regs" command has been removed
1181 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1186 set print type methods (on|off)
1187 show print type methods
1188 Control whether method declarations are displayed by "ptype".
1189 The default is to show them.
1191 set print type typedefs (on|off)
1192 show print type typedefs
1193 Control whether typedef definitions are displayed by "ptype".
1194 The default is to show them.
1196 set filename-display basename|relative|absolute
1197 show filename-display
1198 Control the way in which filenames is displayed.
1199 The default is "relative", which preserves previous behavior.
1201 set trace-buffer-size
1202 show trace-buffer-size
1203 Request target to change the size of trace buffer.
1205 set remote trace-buffer-size-packet auto|on|off
1206 show remote trace-buffer-size-packet
1207 Control the use of the remote protocol `QTBuffer:size' packet.
1211 Control display of debugging messages related to ARM AArch64.
1214 set debug coff-pe-read
1215 show debug coff-pe-read
1216 Control display of debugging messages related to reading of COFF/PE
1221 Control display of debugging messages related to Mach-O symbols
1224 set debug notification
1225 show debug notification
1226 Control display of debugging info for async remote notification.
1230 ** Command parameter changes are now notified using new async record
1231 "=cmd-param-changed".
1232 ** Trace frame changes caused by command "tfind" are now notified using
1233 new async record "=traceframe-changed".
1234 ** The creation, deletion and modification of trace state variables
1235 are now notified using new async records "=tsv-created",
1236 "=tsv-deleted" and "=tsv-modified".
1237 ** The start and stop of process record are now notified using new
1238 async record "=record-started" and "=record-stopped".
1239 ** Memory changes are now notified using new async record
1241 ** The data-disassemble command response will include a "fullname" field
1242 containing the absolute file name when source has been requested.
1243 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1244 command, to allow pattern filling of memory areas.
1245 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1246 library load/unload events.
1247 ** The response to breakpoint commands and breakpoint async records
1248 includes an "installed" field containing a boolean state about each
1249 non-pending tracepoint location is whether installed on target or not.
1250 ** Output of the "-trace-status" command includes a "trace-file" field
1251 containing the name of the trace file being examined. This field is
1252 optional, and only present when examining a trace file.
1253 ** The "fullname" field is now always present along with the "file" field,
1254 even if the file cannot be found by GDB.
1256 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1257 You must have the LZMA library available when configuring GDB for this
1258 feature to be enabled. For more information, see:
1259 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1261 * New remote packets
1264 Set the size of trace buffer. The remote stub reports support for this
1265 packet to gdb's qSupported query.
1268 Enable Branch Trace Store (BTS)-based branch tracing for the current
1269 thread. The remote stub reports support for this packet to gdb's
1273 Disable branch tracing for the current thread. The remote stub reports
1274 support for this packet to gdb's qSupported query.
1277 Read the traced branches for the current thread. The remote stub
1278 reports support for this packet to gdb's qSupported query.
1280 *** Changes in GDB 7.5
1282 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1283 for more x32 ABI info.
1285 * GDB now supports access to MIPS DSP registers on Linux targets.
1287 * GDB now supports debugging microMIPS binaries.
1289 * The "info os" command on GNU/Linux can now display information on
1290 several new classes of objects managed by the operating system:
1291 "info os procgroups" lists process groups
1292 "info os files" lists file descriptors
1293 "info os sockets" lists internet-domain sockets
1294 "info os shm" lists shared-memory regions
1295 "info os semaphores" lists semaphores
1296 "info os msg" lists message queues
1297 "info os modules" lists loaded kernel modules
1299 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1300 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1301 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1302 options and inspect the probe arguments using the new $_probe_arg family
1303 of convenience variables. You can obtain more information about SystemTap
1304 in <http://sourceware.org/systemtap/>.
1306 * GDB now supports reversible debugging on ARM, it allows you to
1307 debug basic ARM and THUMB instructions, and provides
1308 record/replay support.
1310 * The option "symbol-reloading" has been deleted as it is no longer used.
1314 ** GDB commands implemented in Python can now be put in command class
1317 ** The "maint set python print-stack on|off" is now deleted.
1319 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1320 apply "flag enum"-style pretty-printing to any enum.
1322 ** gdb.lookup_symbol can now work when there is no current frame.
1324 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1325 the source at which the symbol was defined.
1327 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1328 method 'value'. The former indicates whether the symbol needs a
1329 frame in order to compute its value, and the latter computes the
1332 ** A new method 'referenced_value' on gdb.Value objects which can
1333 dereference pointer as well as C++ reference values.
1335 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1336 which return the global and static blocks (as gdb.Block objects),
1337 of the underlying symbol table, respectively.
1339 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1340 object associated with a PC value.
1342 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1343 of the address range occupied by code for the current source line.
1345 * Go language support.
1346 GDB now supports debugging programs written in the Go programming
1349 * GDBserver now supports stdio connections.
1350 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1352 * The binary "gdbtui" can no longer be built or installed.
1353 Use "gdb -tui" instead.
1355 * GDB will now print "flag" enums specially. A flag enum is one where
1356 all the enumerator values have no bits in common when pairwise
1357 "and"ed. When printing a value whose type is a flag enum, GDB will
1358 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1359 (gdb) print (enum E) 3
1362 * The filename part of a linespec will now match trailing components
1363 of a source file name. For example, "break gcc/expr.c:1000" will
1364 now set a breakpoint in build/gcc/expr.c, but not
1365 build/libcpp/expr.c.
1367 * The "info proc" and "generate-core-file" commands will now also
1368 work on remote targets connected to GDBserver on Linux.
1370 * The command "info catch" has been removed. It has been disabled
1371 since December 2007.
1373 * The "catch exception" and "catch assert" commands now accept
1374 a condition at the end of the command, much like the "break"
1375 command does. For instance:
1377 (gdb) catch exception Constraint_Error if Barrier = True
1379 Previously, it was possible to add a condition to such catchpoints,
1380 but it had to be done as a second step, after the catchpoint had been
1381 created, using the "condition" command.
1383 * The "info static-tracepoint-marker" command will now also work on
1384 native Linux targets with in-process agent.
1386 * GDB can now set breakpoints on inlined functions.
1388 * The .gdb_index section has been updated to include symbols for
1389 inlined functions. GDB will ignore older .gdb_index sections by
1390 default, which could cause symbol files to be loaded more slowly
1391 until their .gdb_index sections can be recreated. The new command
1392 "set use-deprecated-index-sections on" will cause GDB to use any older
1393 .gdb_index sections it finds. This will restore performance, but the
1394 ability to set breakpoints on inlined functions will be lost in symbol
1395 files with older .gdb_index sections.
1397 The .gdb_index section has also been updated to record more information
1398 about each symbol. This speeds up the "info variables", "info functions"
1399 and "info types" commands when used with programs having the .gdb_index
1400 section, as well as speeding up debugging with shared libraries using
1401 the .gdb_index section.
1403 * Ada support for GDB/MI Variable Objects has been added.
1405 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1410 ** New command -info-os is the MI equivalent of "info os".
1412 ** Output logs ("set logging" and related) now include MI output.
1416 ** "set use-deprecated-index-sections on|off"
1417 "show use-deprecated-index-sections on|off"
1418 Controls the use of deprecated .gdb_index sections.
1420 ** "catch load" and "catch unload" can be used to stop when a shared
1421 library is loaded or unloaded, respectively.
1423 ** "enable count" can be used to auto-disable a breakpoint after
1426 ** "info vtbl" can be used to show the virtual method tables for
1427 C++ and Java objects.
1429 ** "explore" and its sub commands "explore value" and "explore type"
1430 can be used to recursively explore values and types of
1431 expressions. These commands are available only if GDB is
1432 configured with '--with-python'.
1434 ** "info auto-load" shows status of all kinds of auto-loaded files,
1435 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1436 sequences of commands files, "info auto-load python-scripts"
1437 shows status of auto-loading Python script files,
1438 "info auto-load local-gdbinit" shows status of loading init file
1439 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1440 status of inferior specific thread debugging shared library loading.
1442 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1443 and "show auto-load-scripts" commands have been deprecated, use their
1444 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1445 and "show auto-load python-scripts" counterparts instead.
1447 ** "dprintf location,format,args..." creates a dynamic printf, which
1448 is basically a breakpoint that does a printf and immediately
1449 resumes your program's execution, so it is like a printf that you
1450 can insert dynamically at runtime instead of at compiletime.
1452 ** "set print symbol"
1454 Controls whether GDB attempts to display the symbol, if any,
1455 corresponding to addresses it prints. This defaults to "on", but
1456 you can set it to "off" to restore GDB's previous behavior.
1458 * Deprecated commands
1460 ** For the Renesas Super-H architecture, the "regs" command has been
1461 deprecated, and "info all-registers" should be used instead.
1465 Renesas RL78 rl78-*-elf
1466 HP OpenVMS ia64 ia64-hp-openvms*
1468 * GDBserver supports evaluation of breakpoint conditions. When
1469 support is advertised by GDBserver, GDB may be told to send the
1470 breakpoint conditions in bytecode form to GDBserver. GDBserver
1471 will only report the breakpoint trigger to GDB when its condition
1476 set mips compression
1477 show mips compression
1478 Select the compressed ISA encoding used in functions that have no symbol
1479 information available. The encoding can be set to either of:
1482 and is updated automatically from ELF file flags if available.
1484 set breakpoint condition-evaluation
1485 show breakpoint condition-evaluation
1486 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1487 GDBserver ("target"). Default option "auto" chooses the most efficient
1489 This option can improve debugger efficiency depending on the speed of the
1493 Disable auto-loading globally.
1496 Show auto-loading setting of all kinds of auto-loaded files.
1498 set auto-load gdb-scripts on|off
1499 show auto-load gdb-scripts
1500 Control auto-loading of GDB canned sequences of commands files.
1502 set auto-load python-scripts on|off
1503 show auto-load python-scripts
1504 Control auto-loading of Python script files.
1506 set auto-load local-gdbinit on|off
1507 show auto-load local-gdbinit
1508 Control loading of init file (.gdbinit) from current directory.
1510 set auto-load libthread-db on|off
1511 show auto-load libthread-db
1512 Control auto-loading of inferior specific thread debugging shared library.
1514 set auto-load scripts-directory <dir1>[:<dir2>...]
1515 show auto-load scripts-directory
1516 Set a list of directories from which to load auto-loaded scripts.
1517 Automatically loaded Python scripts and GDB scripts are located in one
1518 of the directories listed by this option.
1519 The delimiter (':' above) may differ according to the host platform.
1521 set auto-load safe-path <dir1>[:<dir2>...]
1522 show auto-load safe-path
1523 Set a list of directories from which it is safe to auto-load files.
1524 The delimiter (':' above) may differ according to the host platform.
1526 set debug auto-load on|off
1527 show debug auto-load
1528 Control display of debugging info for auto-loading the files above.
1530 set dprintf-style gdb|call|agent
1532 Control the way in which a dynamic printf is performed; "gdb"
1533 requests a GDB printf command, while "call" causes dprintf to call a
1534 function in the inferior. "agent" requests that the target agent
1535 (such as GDBserver) do the printing.
1537 set dprintf-function <expr>
1538 show dprintf-function
1539 set dprintf-channel <expr>
1540 show dprintf-channel
1541 Set the function and optional first argument to the call when using
1542 the "call" style of dynamic printf.
1544 set disconnected-dprintf on|off
1545 show disconnected-dprintf
1546 Control whether agent-style dynamic printfs continue to be in effect
1547 after GDB disconnects.
1549 * New configure options
1551 --with-auto-load-dir
1552 Configure default value for the 'set auto-load scripts-directory'
1553 setting above. It defaults to '$debugdir:$datadir/auto-load',
1554 $debugdir representing global debugging info directories (available
1555 via 'show debug-file-directory') and $datadir representing GDB's data
1556 directory (available via 'show data-directory').
1558 --with-auto-load-safe-path
1559 Configure default value for the 'set auto-load safe-path' setting
1560 above. It defaults to the --with-auto-load-dir setting.
1562 --without-auto-load-safe-path
1563 Set 'set auto-load safe-path' to '/', effectively disabling this
1566 * New remote packets
1568 z0/z1 conditional breakpoints extension
1570 The z0/z1 breakpoint insertion packets have been extended to carry
1571 a list of conditional expressions over to the remote stub depending on the
1572 condition evaluation mode. The use of this extension can be controlled
1573 via the "set remote conditional-breakpoints-packet" command.
1577 Specify the signals which the remote stub may pass to the debugged
1578 program without GDB involvement.
1580 * New command line options
1582 --init-command=FILE, -ix Like --command, -x but execute it
1583 before loading inferior.
1584 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1585 execute it before loading inferior.
1587 *** Changes in GDB 7.4
1589 * GDB now handles ambiguous linespecs more consistently; the existing
1590 FILE:LINE support has been expanded to other types of linespecs. A
1591 breakpoint will now be set on all matching locations in all
1592 inferiors, and locations will be added or removed according to
1595 * GDB now allows you to skip uninteresting functions and files when
1596 stepping with the "skip function" and "skip file" commands.
1598 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1599 and "show remote hardware-watchpoint-length-limit". These allows to
1600 set or show the maximum length limit (in bytes) of a remote
1601 target hardware watchpoint.
1603 This allows e.g. to use "unlimited" hardware watchpoints with the
1604 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1605 watchpoints are slower than real hardware watchpoints but are
1606 significantly faster than gdb software watchpoints.
1610 ** The register_pretty_printer function in module gdb.printing now takes
1611 an optional `replace' argument. If True, the new printer replaces any
1614 ** The "maint set python print-stack on|off" command has been
1615 deprecated and will be deleted in GDB 7.5.
1616 A new command: "set python print-stack none|full|message" has
1617 replaced it. Additionally, the default for "print-stack" is
1618 now "message", which just prints the error message without
1621 ** A prompt substitution hook (prompt_hook) is now available to the
1624 ** A new Python module, gdb.prompt has been added to the GDB Python
1625 modules library. This module provides functionality for
1626 escape sequences in prompts (used by set/show
1627 extended-prompt). These escape sequences are replaced by their
1628 corresponding value.
1630 ** Python commands and convenience-functions located in
1631 'data-directory'/python/gdb/command and
1632 'data-directory'/python/gdb/function are now automatically loaded
1635 ** Blocks now provide four new attributes. global_block and
1636 static_block will return the global and static blocks
1637 respectively. is_static and is_global are boolean attributes
1638 that indicate if the block is one of those two types.
1640 ** Symbols now provide the "type" attribute, the type of the symbol.
1642 ** The "gdb.breakpoint" function has been deprecated in favor of
1645 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1646 of a function. This class is based on the "finish" command
1647 available in the CLI.
1649 ** Type objects for struct and union types now allow access to
1650 the fields using standard Python dictionary (mapping) methods.
1651 For example, "some_type['myfield']" now works, as does
1652 "some_type.items()".
1654 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1657 ** A new function, "deep_items" has been added to the gdb.types
1658 module in the GDB Python modules library. This function returns
1659 an iterator over the fields of a struct or union type. Unlike
1660 the standard Python "iteritems" method, it will recursively traverse
1661 any anonymous fields.
1665 ** "*stopped" events can report several new "reason"s, such as
1668 ** Breakpoint changes are now notified using new async records, like
1669 "=breakpoint-modified".
1671 ** New command -ada-task-info.
1673 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1674 $sdir specifies the default system locations of shared libraries.
1675 $pdir specifies the directory where the libpthread used by the application
1678 GDB no longer looks in $sdir and $pdir after it has searched the directories
1679 mentioned in libthread-db-search-path. If you want to search those
1680 directories, they must be specified in libthread-db-search-path.
1681 The default value of libthread-db-search-path on GNU/Linux and Solaris
1682 systems is now "$sdir:$pdir".
1684 $pdir is not supported by gdbserver, it is currently ignored.
1685 $sdir is supported by gdbserver.
1687 * New configure option --with-iconv-bin.
1688 When using the internationalization support like the one in the GNU C
1689 library, GDB will invoke the "iconv" program to get a list of supported
1690 character sets. If this program lives in a non-standard location, one can
1691 use this option to specify where to find it.
1693 * When natively debugging programs on PowerPC BookE processors running
1694 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1695 watchpoints, which specify a mask in addition to an address to watch.
1696 The mask specifies that some bits of an address (the bits which are
1697 reset in the mask) should be ignored when matching the address accessed
1698 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1699 section in the user manual for more details.
1701 * The new option --once causes GDBserver to stop listening for connections once
1702 the first connection is made. The listening port used by GDBserver will
1703 become available after that.
1705 * New commands "info macros" and "alias" have been added.
1707 * New function parameters suffix @entry specifies value of function parameter
1708 at the time the function got called. Entry values are available only since
1714 "!" is now an alias of the "shell" command.
1715 Note that no space is needed between "!" and SHELL COMMAND.
1719 watch EXPRESSION mask MASK_VALUE
1720 The watch command now supports the mask argument which allows creation
1721 of masked watchpoints, if the current architecture supports this feature.
1723 info auto-load-scripts [REGEXP]
1724 This command was formerly named "maintenance print section-scripts".
1725 It is now generally useful and is no longer a maintenance-only command.
1727 info macro [-all] [--] MACRO
1728 The info macro command has new options `-all' and `--'. The first for
1729 printing all definitions of a macro. The second for explicitly specifying
1730 the end of arguments and the beginning of the macro name in case the macro
1731 name starts with a hyphen.
1733 collect[/s] EXPRESSIONS
1734 The tracepoint collect command now takes an optional modifier "/s"
1735 that directs it to dereference pointer-to-character types and
1736 collect the bytes of memory up to a zero byte. The behavior is
1737 similar to what you see when you use the regular print command on a
1738 string. An optional integer following the "/s" sets a bound on the
1739 number of bytes that will be collected.
1742 The trace start command now interprets any supplied arguments as a
1743 note to be recorded with the trace run, with an effect similar to
1744 setting the variable trace-notes.
1747 The trace stop command now interprets any arguments as a note to be
1748 mentioned along with the tstatus report that the trace was stopped
1749 with a command. The effect is similar to setting the variable
1752 * Tracepoints can now be enabled and disabled at any time after a trace
1753 experiment has been started using the standard "enable" and "disable"
1754 commands. It is now possible to start a trace experiment with no enabled
1755 tracepoints; GDB will display a warning, but will allow the experiment to
1756 begin, assuming that tracepoints will be enabled as needed while the trace
1759 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1760 locations with 4-byte instructions, when they were previously
1761 limited to locations with instructions of 5 bytes or longer.
1765 set debug dwarf2-read
1766 show debug dwarf2-read
1767 Turns on or off display of debugging messages related to reading
1768 DWARF debug info. The default is off.
1770 set debug symtab-create
1771 show debug symtab-create
1772 Turns on or off display of debugging messages related to symbol table
1773 creation. The default is off.
1776 show extended-prompt
1777 Set the GDB prompt, and allow escape sequences to be inserted to
1778 display miscellaneous information (see 'help set extended-prompt'
1779 for the list of sequences). This prompt (and any information
1780 accessed through the escape sequences) is updated every time the
1781 prompt is displayed.
1783 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1784 show print entry-values
1785 Set printing of frame argument values at function entry. In some cases
1786 GDB can determine the value of function argument which was passed by the
1787 function caller, even if the value was modified inside the called function.
1789 set debug entry-values
1790 show debug entry-values
1791 Control display of debugging info for determining frame argument values at
1792 function entry and virtual tail call frames.
1794 set basenames-may-differ
1795 show basenames-may-differ
1796 Set whether a source file may have multiple base names.
1797 (A "base name" is the name of a file with the directory part removed.
1798 Example: The base name of "/home/user/hello.c" is "hello.c".)
1799 If set, GDB will canonicalize file names (e.g., expand symlinks)
1800 before comparing them. Canonicalization is an expensive operation,
1801 but it allows the same file be known by more than one base name.
1802 If not set (the default), all source files are assumed to have just
1803 one base name, and gdb will do file name comparisons more efficiently.
1809 Set a user name and notes for the current and any future trace runs.
1810 This is useful for long-running and/or disconnected traces, to
1811 inform others (or yourself) as to who is running the trace, supply
1812 contact information, or otherwise explain what is going on.
1814 set trace-stop-notes
1815 show trace-stop-notes
1816 Set a note attached to the trace run, that is displayed when the
1817 trace has been stopped by a tstop command. This is useful for
1818 instance as an explanation, if you are stopping a trace run that was
1819 started by someone else.
1821 * New remote packets
1825 Dynamically enable a tracepoint in a started trace experiment.
1829 Dynamically disable a tracepoint in a started trace experiment.
1833 Set the user and notes of the trace run.
1837 Query the current status of a tracepoint.
1841 Query the minimum length of instruction at which a fast tracepoint may
1844 * Dcache size (number of lines) and line-size are now runtime-configurable
1845 via "set dcache line" and "set dcache line-size" commands.
1849 Texas Instruments TMS320C6x tic6x-*-*
1853 Renesas RL78 rl78-*-elf
1855 *** Changes in GDB 7.3.1
1857 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1859 *** Changes in GDB 7.3
1861 * GDB has a new command: "thread find [REGEXP]".
1862 It finds the thread id whose name, target id, or thread extra info
1863 matches the given regular expression.
1865 * The "catch syscall" command now works on mips*-linux* targets.
1867 * The -data-disassemble MI command now supports modes 2 and 3 for
1868 dumping the instruction opcodes.
1870 * New command line options
1872 -data-directory DIR Specify DIR as the "data-directory".
1873 This is mostly for testing purposes.
1875 * The "maint set python auto-load on|off" command has been renamed to
1876 "set auto-load-scripts on|off".
1878 * GDB has a new command: "set directories".
1879 It is like the "dir" command except that it replaces the
1880 source path list instead of augmenting it.
1882 * GDB now understands thread names.
1884 On GNU/Linux, "info threads" will display the thread name as set by
1885 prctl or pthread_setname_np.
1887 There is also a new command, "thread name", which can be used to
1888 assign a name internally for GDB to display.
1891 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1892 has been integrated into GDB.
1896 ** The function gdb.Write now accepts an optional keyword 'stream'.
1897 This keyword, when provided, will direct the output to either
1898 stdout, stderr, or GDB's logging output.
1900 ** Parameters can now be be sub-classed in Python, and in particular
1901 you may implement the get_set_doc and get_show_doc functions.
1902 This improves how Parameter set/show documentation is processed
1903 and allows for more dynamic content.
1905 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1906 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1907 have an is_valid method.
1909 ** Breakpoints can now be sub-classed in Python, and in particular
1910 you may implement a 'stop' function that is executed each time
1911 the inferior reaches that breakpoint.
1913 ** New function gdb.lookup_global_symbol looks up a global symbol.
1915 ** GDB values in Python are now callable if the value represents a
1916 function. For example, if 'some_value' represents a function that
1917 takes two integer parameters and returns a value, you can call
1918 that function like so:
1920 result = some_value (10,20)
1922 ** Module gdb.types has been added.
1923 It contains a collection of utilities for working with gdb.Types objects:
1924 get_basic_type, has_field, make_enum_dict.
1926 ** Module gdb.printing has been added.
1927 It contains utilities for writing and registering pretty-printers.
1928 New classes: PrettyPrinter, SubPrettyPrinter,
1929 RegexpCollectionPrettyPrinter.
1930 New function: register_pretty_printer.
1932 ** New commands "info pretty-printers", "enable pretty-printer" and
1933 "disable pretty-printer" have been added.
1935 ** gdb.parameter("directories") is now available.
1937 ** New function gdb.newest_frame returns the newest frame in the
1940 ** The gdb.InferiorThread class has a new "name" attribute. This
1941 holds the thread's name.
1943 ** Python Support for Inferior events.
1944 Python scripts can add observers to be notified of events
1945 occurring in the process being debugged.
1946 The following events are currently supported:
1947 - gdb.events.cont Continue event.
1948 - gdb.events.exited Inferior exited event.
1949 - gdb.events.stop Signal received, and Breakpoint hit events.
1953 ** GDB now puts template parameters in scope when debugging in an
1954 instantiation. For example, if you have:
1956 template<int X> int func (void) { return X; }
1958 then if you step into func<5>, "print X" will show "5". This
1959 feature requires proper debuginfo support from the compiler; it
1960 was added to GCC 4.5.
1962 ** The motion commands "next", "finish", "until", and "advance" now
1963 work better when exceptions are thrown. In particular, GDB will
1964 no longer lose control of the inferior; instead, the GDB will
1965 stop the inferior at the point at which the exception is caught.
1966 This functionality requires a change in the exception handling
1967 code that was introduced in GCC 4.5.
1969 * GDB now follows GCC's rules on accessing volatile objects when
1970 reading or writing target state during expression evaluation.
1971 One notable difference to prior behavior is that "print x = 0"
1972 no longer generates a read of x; the value of the assignment is
1973 now always taken directly from the value being assigned.
1975 * GDB now has some support for using labels in the program's source in
1976 linespecs. For instance, you can use "advance label" to continue
1977 execution to a label.
1979 * GDB now has support for reading and writing a new .gdb_index
1980 section. This section holds a fast index of DWARF debugging
1981 information and can be used to greatly speed up GDB startup and
1982 operation. See the documentation for `save gdb-index' for details.
1984 * The "watch" command now accepts an optional "-location" argument.
1985 When used, this causes GDB to watch the memory referred to by the
1986 expression. Such a watchpoint is never deleted due to it going out
1989 * GDB now supports thread debugging of core dumps on GNU/Linux.
1991 GDB now activates thread debugging using the libthread_db library
1992 when debugging GNU/Linux core dumps, similarly to when debugging
1993 live processes. As a result, when debugging a core dump file, GDB
1994 is now able to display pthread_t ids of threads. For example, "info
1995 threads" shows the same output as when debugging the process when it
1996 was live. In earlier releases, you'd see something like this:
1999 * 1 LWP 6780 main () at main.c:10
2001 While now you see this:
2004 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2006 It is also now possible to inspect TLS variables when debugging core
2009 When debugging a core dump generated on a machine other than the one
2010 used to run GDB, you may need to point GDB at the correct
2011 libthread_db library with the "set libthread-db-search-path"
2012 command. See the user manual for more details on this command.
2014 * When natively debugging programs on PowerPC BookE processors running
2015 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2016 which stop execution of the inferior whenever it executes an instruction
2017 at any address within the specified range. See the "PowerPC Embedded"
2018 section in the user manual for more details.
2020 * New features in the GDB remote stub, GDBserver
2022 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2023 and i686 LynxOS (version 5.x).
2025 ** GDBserver is now supported on Blackfin Linux.
2027 * New native configurations
2029 ia64 HP-UX ia64-*-hpux*
2033 Analog Devices, Inc. Blackfin Processor bfin-*
2035 * Ada task switching is now supported on sparc-elf targets when
2036 debugging a program using the Ravenscar Profile. For more information,
2037 see the "Tasking Support when using the Ravenscar Profile" section
2038 in the GDB user manual.
2040 * Guile support was removed.
2042 * New features in the GNU simulator
2044 ** The --map-info flag lists all known core mappings.
2046 ** CFI flashes may be simulated via the "cfi" device.
2048 *** Changes in GDB 7.2
2050 * Shared library support for remote targets by default
2052 When GDB is configured for a generic, non-OS specific target, like
2053 for example, --target=arm-eabi or one of the many *-*-elf targets,
2054 GDB now queries remote stubs for loaded shared libraries using the
2055 `qXfer:libraries:read' packet. Previously, shared library support
2056 was always disabled for such configurations.
2060 ** Argument Dependent Lookup (ADL)
2062 In C++ ADL lookup directs function search to the namespaces of its
2063 arguments even if the namespace has not been imported.
2073 Here the compiler will search for `foo' in the namespace of 'b'
2074 and find A::foo. GDB now supports this. This construct is commonly
2075 used in the Standard Template Library for operators.
2077 ** Improved User Defined Operator Support
2079 In addition to member operators, GDB now supports lookup of operators
2080 defined in a namespace and imported with a `using' directive, operators
2081 defined in the global scope, operators imported implicitly from an
2082 anonymous namespace, and the ADL operators mentioned in the previous
2084 GDB now also supports proper overload resolution for all the previously
2085 mentioned flavors of operators.
2087 ** static const class members
2089 Printing of static const class members that are initialized in the
2090 class definition has been fixed.
2092 * Windows Thread Information Block access.
2094 On Windows targets, GDB now supports displaying the Windows Thread
2095 Information Block (TIB) structure. This structure is visible either
2096 by using the new command `info w32 thread-information-block' or, by
2097 dereferencing the new convenience variable named `$_tlb', a
2098 thread-specific pointer to the TIB. This feature is also supported
2099 when remote debugging using GDBserver.
2101 * Static tracepoints
2103 Static tracepoints are calls in the user program into a tracing
2104 library. One such library is a port of the LTTng kernel tracer to
2105 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2106 When debugging with GDBserver, GDB now supports combining the GDB
2107 tracepoint machinery with such libraries. For example: the user can
2108 use GDB to probe a static tracepoint marker (a call from the user
2109 program into the tracing library) with the new "strace" command (see
2110 "New commands" below). This creates a "static tracepoint" in the
2111 breakpoint list, that can be manipulated with the same feature set
2112 as fast and regular tracepoints. E.g., collect registers, local and
2113 global variables, collect trace state variables, and define
2114 tracepoint conditions. In addition, the user can collect extra
2115 static tracepoint marker specific data, by collecting the new
2116 $_sdata internal variable. When analyzing the trace buffer, you can
2117 inspect $_sdata like any other variable available to GDB. For more
2118 information, see the "Tracepoints" chapter in GDB user manual. New
2119 remote packets have been defined to support static tracepoints, see
2120 the "New remote packets" section below.
2122 * Better reconstruction of tracepoints after disconnected tracing
2124 GDB will attempt to download the original source form of tracepoint
2125 definitions when starting a trace run, and then will upload these
2126 upon reconnection to the target, resulting in a more accurate
2127 reconstruction of the tracepoints that are in use on the target.
2131 You can now exercise direct control over the ways that GDB can
2132 affect your program. For instance, you can disallow the setting of
2133 breakpoints, so that the program can run continuously (assuming
2134 non-stop mode). In addition, the "observer" variable is available
2135 to switch all of the different controls; in observer mode, GDB
2136 cannot affect the target's behavior at all, which is useful for
2137 tasks like diagnosing live systems in the field.
2139 * The new convenience variable $_thread holds the number of the
2142 * New remote packets
2146 Return the address of the Windows Thread Information Block of a given thread.
2150 In response to several of the tracepoint packets, the target may now
2151 also respond with a number of intermediate `qRelocInsn' request
2152 packets before the final result packet, to have GDB handle
2153 relocating an instruction to execute at a different address. This
2154 is particularly useful for stubs that support fast tracepoints. GDB
2155 reports support for this feature in the qSupported packet.
2159 List static tracepoint markers in the target program.
2163 List static tracepoint markers at a given address in the target
2166 qXfer:statictrace:read
2168 Read the static trace data collected (by a `collect $_sdata'
2169 tracepoint action). The remote stub reports support for this packet
2170 to gdb's qSupported query.
2174 Send the current settings of GDB's permission flags.
2178 Send part of the source (textual) form of a tracepoint definition,
2179 which includes location, conditional, and action list.
2181 * The source command now accepts a -s option to force searching for the
2182 script in the source search path even if the script name specifies
2185 * New features in the GDB remote stub, GDBserver
2187 - GDBserver now support tracepoints (including fast tracepoints, and
2188 static tracepoints). The feature is currently supported by the
2189 i386-linux and amd64-linux builds. See the "Tracepoints support
2190 in gdbserver" section in the manual for more information.
2192 GDBserver JIT compiles the tracepoint's conditional agent
2193 expression bytecode into native code whenever possible for low
2194 overhead dynamic tracepoints conditionals. For such tracepoints,
2195 an expression that examines program state is evaluated when the
2196 tracepoint is reached, in order to determine whether to capture
2197 trace data. If the condition is simple and false, processing the
2198 tracepoint finishes very quickly and no data is gathered.
2200 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2201 for static tracepoints support.
2203 - GDBserver now supports x86_64 Windows 64-bit debugging.
2205 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2206 it understands register description.
2208 * The --batch flag now disables pagination and queries.
2210 * X86 general purpose registers
2212 GDB now supports reading/writing byte, word and double-word x86
2213 general purpose registers directly. This means you can use, say,
2214 $ah or $ax to refer, respectively, to the byte register AH and
2215 16-bit word register AX that are actually portions of the 32-bit
2216 register EAX or 64-bit register RAX.
2218 * The `commands' command now accepts a range of breakpoints to modify.
2219 A plain `commands' following a command that creates multiple
2220 breakpoints affects all the breakpoints set by that command. This
2221 applies to breakpoints set by `rbreak', and also applies when a
2222 single `break' command creates multiple breakpoints (e.g.,
2223 breakpoints on overloaded c++ functions).
2225 * The `rbreak' command now accepts a filename specification as part of
2226 its argument, limiting the functions selected by the regex to those
2227 in the specified file.
2229 * Support for remote debugging Windows and SymbianOS shared libraries
2230 from Unix hosts has been improved. Non Windows GDB builds now can
2231 understand target reported file names that follow MS-DOS based file
2232 system semantics, such as file names that include drive letters and
2233 use the backslash character as directory separator. This makes it
2234 possible to transparently use the "set sysroot" and "set
2235 solib-search-path" on Unix hosts to point as host copies of the
2236 target's shared libraries. See the new command "set
2237 target-file-system-kind" described below, and the "Commands to
2238 specify files" section in the user manual for more information.
2242 eval template, expressions...
2243 Convert the values of one or more expressions under the control
2244 of the string template to a command line, and call it.
2246 set target-file-system-kind unix|dos-based|auto
2247 show target-file-system-kind
2248 Set or show the assumed file system kind for target reported file
2251 save breakpoints <filename>
2252 Save all current breakpoint definitions to a file suitable for use
2253 in a later debugging session. To read the saved breakpoint
2254 definitions, use the `source' command.
2256 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2259 info static-tracepoint-markers
2260 Display information about static tracepoint markers in the target.
2262 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2263 Define a static tracepoint by probing a marker at the given
2264 function, line, address, or marker ID.
2268 Enable and disable observer mode.
2270 set may-write-registers on|off
2271 set may-write-memory on|off
2272 set may-insert-breakpoints on|off
2273 set may-insert-tracepoints on|off
2274 set may-insert-fast-tracepoints on|off
2275 set may-interrupt on|off
2276 Set individual permissions for GDB effects on the target. Note that
2277 some of these settings can have undesirable or surprising
2278 consequences, particularly when changed in the middle of a session.
2279 For instance, disabling the writing of memory can prevent
2280 breakpoints from being inserted, cause single-stepping to fail, or
2281 even crash your program, if you disable after breakpoints have been
2282 inserted. However, GDB should not crash.
2284 set record memory-query on|off
2285 show record memory-query
2286 Control whether to stop the inferior if memory changes caused
2287 by an instruction cannot be recorded.
2292 The disassemble command now supports "start,+length" form of two arguments.
2296 ** GDB now provides a new directory location, called the python directory,
2297 where Python scripts written for GDB can be installed. The location
2298 of that directory is <data-directory>/python, where <data-directory>
2299 is the GDB data directory. For more details, see section `Scripting
2300 GDB using Python' in the manual.
2302 ** The GDB Python API now has access to breakpoints, symbols, symbol
2303 tables, program spaces, inferiors, threads and frame's code blocks.
2304 Additionally, GDB Parameters can now be created from the API, and
2305 manipulated via set/show in the CLI.
2307 ** New functions gdb.target_charset, gdb.target_wide_charset,
2308 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2310 ** New exception gdb.GdbError.
2312 ** Pretty-printers are now also looked up in the current program space.
2314 ** Pretty-printers can now be individually enabled and disabled.
2316 ** GDB now looks for names of Python scripts to auto-load in a
2317 special section named `.debug_gdb_scripts', in addition to looking
2318 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2320 * Tracepoint actions were unified with breakpoint commands. In particular,
2321 there are no longer differences in "info break" output for breakpoints and
2322 tracepoints and the "commands" command can be used for both tracepoints and
2323 regular breakpoints.
2327 ARM Symbian arm*-*-symbianelf*
2329 * D language support.
2330 GDB now supports debugging programs written in the D programming
2333 * GDB now supports the extended ptrace interface for PowerPC which is
2334 available since Linux kernel version 2.6.34. This automatically enables
2335 any hardware breakpoints and additional hardware watchpoints available in
2336 the processor. The old ptrace interface exposes just one hardware
2337 watchpoint and no hardware breakpoints.
2339 * GDB is now able to use the Data Value Compare (DVC) register available on
2340 embedded PowerPC processors to implement in hardware simple watchpoint
2341 conditions of the form:
2343 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2345 This works in native GDB running on Linux kernels with the extended ptrace
2346 interface mentioned above.
2348 *** Changes in GDB 7.1
2352 ** Namespace Support
2354 GDB now supports importing of namespaces in C++. This enables the
2355 user to inspect variables from imported namespaces. Support for
2356 namepace aliasing has also been added. So, if a namespace is
2357 aliased in the current scope (e.g. namepace C=A; ) the user can
2358 print variables using the alias (e.g. (gdb) print C::x).
2362 All known bugs relating to the printing of virtual base class were
2363 fixed. It is now possible to call overloaded static methods using a
2368 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2369 and reinterpret_cast<> are now handled by the C++ expression parser.
2373 Xilinx MicroBlaze microblaze-*-*
2378 Xilinx MicroBlaze microblaze
2381 * Multi-program debugging.
2383 GDB now has support for multi-program (a.k.a. multi-executable or
2384 multi-exec) debugging. This allows for debugging multiple inferiors
2385 simultaneously each running a different program under the same GDB
2386 session. See "Debugging Multiple Inferiors and Programs" in the
2387 manual for more information. This implied some user visible changes
2388 in the multi-inferior support. For example, "info inferiors" now
2389 lists inferiors that are not running yet or that have exited
2390 already. See also "New commands" and "New options" below.
2392 * New tracing features
2394 GDB's tracepoint facility now includes several new features:
2396 ** Trace state variables
2398 GDB tracepoints now include support for trace state variables, which
2399 are variables managed by the target agent during a tracing
2400 experiment. They are useful for tracepoints that trigger each
2401 other, so for instance one tracepoint can count hits in a variable,
2402 and then a second tracepoint has a condition that is true when the
2403 count reaches a particular value. Trace state variables share the
2404 $-syntax of GDB convenience variables, and can appear in both
2405 tracepoint actions and condition expressions. Use the "tvariable"
2406 command to create, and "info tvariables" to view; see "Trace State
2407 Variables" in the manual for more detail.
2411 GDB now includes an option for defining fast tracepoints, which
2412 targets may implement more efficiently, such as by installing a jump
2413 into the target agent rather than a trap instruction. The resulting
2414 speedup can be by two orders of magnitude or more, although the
2415 tradeoff is that some program locations on some target architectures
2416 might not allow fast tracepoint installation, for instance if the
2417 instruction to be replaced is shorter than the jump. To request a
2418 fast tracepoint, use the "ftrace" command, with syntax identical to
2419 the regular trace command.
2421 ** Disconnected tracing
2423 It is now possible to detach GDB from the target while it is running
2424 a trace experiment, then reconnect later to see how the experiment
2425 is going. In addition, a new variable disconnected-tracing lets you
2426 tell the target agent whether to continue running a trace if the
2427 connection is lost unexpectedly.
2431 GDB now has the ability to save the trace buffer into a file, and
2432 then use that file as a target, similarly to you can do with
2433 corefiles. You can select trace frames, print data that was
2434 collected in them, and use tstatus to display the state of the
2435 tracing run at the moment that it was saved. To create a trace
2436 file, use "tsave <filename>", and to use it, do "target tfile
2439 ** Circular trace buffer
2441 You can ask the target agent to handle the trace buffer as a
2442 circular buffer, discarding the oldest trace frames to make room for
2443 newer ones, by setting circular-trace-buffer to on. This feature may
2444 not be available for all target agents.
2449 The disassemble command, when invoked with two arguments, now requires
2450 the arguments to be comma-separated.
2453 The info variables command now displays variable definitions. Files
2454 which only declare a variable are not shown.
2457 The source command is now capable of sourcing Python scripts.
2458 This feature is dependent on the debugger being build with Python
2461 Related to this enhancement is also the introduction of a new command
2462 "set script-extension" (see below).
2464 * New commands (for set/show, see "New options" below)
2466 record save [<FILENAME>]
2467 Save a file (in core file format) containing the process record
2468 execution log for replay debugging at a later time.
2470 record restore <FILENAME>
2471 Restore the process record execution log that was saved at an
2472 earlier time, for replay debugging.
2474 add-inferior [-copies <N>] [-exec <FILENAME>]
2477 clone-inferior [-copies <N>] [ID]
2478 Make a new inferior ready to execute the same program another
2479 inferior has loaded.
2484 maint info program-spaces
2485 List the program spaces loaded into GDB.
2487 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2488 show remote interrupt-sequence
2489 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2490 as the sequence to the remote target in order to interrupt the execution.
2491 Ctrl-C is a default. Some system prefers BREAK which is high level of
2492 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2493 Magic SysRq g. It is BREAK signal and character 'g'.
2495 set remote interrupt-on-connect [on | off]
2496 show remote interrupt-on-connect
2497 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2498 remote target when gdb connects to it. This is needed when you debug
2501 set remotebreak [on | off]
2503 Deprecated. Use "set/show remote interrupt-sequence" instead.
2505 tvariable $NAME [ = EXP ]
2506 Create or modify a trace state variable.
2509 List trace state variables and their values.
2511 delete tvariable $NAME ...
2512 Delete one or more trace state variables.
2515 Evaluate the given expressions without collecting anything into the
2516 trace buffer. (Valid in tracepoint actions only.)
2518 ftrace FN / FILE:LINE / *ADDR
2519 Define a fast tracepoint at the given function, line, or address.
2521 * New expression syntax
2523 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2524 GDB now parses 0b101010 identically with 42.
2528 set follow-exec-mode new|same
2529 show follow-exec-mode
2530 Control whether GDB reuses the same inferior across an exec call or
2531 creates a new one. This is useful to be able to restart the old
2532 executable after the inferior having done an exec call.
2534 set default-collect EXPR, ...
2535 show default-collect
2536 Define a list of expressions to be collected at each tracepoint.
2537 This is a useful way to ensure essential items are not overlooked,
2538 such as registers or a critical global variable.
2540 set disconnected-tracing
2541 show disconnected-tracing
2542 If set to 1, the target is instructed to continue tracing if it
2543 loses its connection to GDB. If 0, the target is to stop tracing
2546 set circular-trace-buffer
2547 show circular-trace-buffer
2548 If set to on, the target is instructed to use a circular trace buffer
2549 and discard the oldest trace frames instead of stopping the trace due
2550 to a full trace buffer. If set to off, the trace stops when the buffer
2551 fills up. Some targets may not support this.
2553 set script-extension off|soft|strict
2554 show script-extension
2555 If set to "off", the debugger does not perform any script language
2556 recognition, and all sourced files are assumed to be GDB scripts.
2557 If set to "soft" (the default), files are sourced according to
2558 filename extension, falling back to GDB scripts if the first
2560 If set to "strict", files are sourced according to filename extension.
2562 set ada trust-PAD-over-XVS on|off
2563 show ada trust-PAD-over-XVS
2564 If off, activate a workaround against a bug in the debugging information
2565 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2566 the GCC sources for more information about the GNAT encoding and
2567 PAD types in particular). It is always safe to set this option to
2568 off, but this introduces a slight performance penalty. The default
2571 * Python API Improvements
2573 ** GDB provides the new class gdb.LazyString. This is useful in
2574 some pretty-printing cases. The new method gdb.Value.lazy_string
2575 provides a simple way to create objects of this type.
2577 ** The fields returned by gdb.Type.fields now have an
2578 `is_base_class' attribute.
2580 ** The new method gdb.Type.range returns the range of an array type.
2582 ** The new method gdb.parse_and_eval can be used to parse and
2583 evaluate an expression.
2585 * New remote packets
2588 Define a trace state variable.
2591 Get the current value of a trace state variable.
2594 Set desired tracing behavior upon disconnection.
2597 Set the trace buffer to be linear or circular.
2600 Get data about the tracepoints currently in use.
2604 Process record now works correctly with hardware watchpoints.
2606 Multiple bug fixes have been made to the mips-irix port, making it
2607 much more reliable. In particular:
2608 - Debugging threaded applications is now possible again. Previously,
2609 GDB would hang while starting the program, or while waiting for
2610 the program to stop at a breakpoint.
2611 - Attaching to a running process no longer hangs.
2612 - An error occurring while loading a core file has been fixed.
2613 - Changing the value of the PC register now works again. This fixes
2614 problems observed when using the "jump" command, or when calling
2615 a function from GDB, or even when assigning a new value to $pc.
2616 - With the "finish" and "return" commands, the return value for functions
2617 returning a small array is now correctly printed.
2618 - It is now possible to break on shared library code which gets executed
2619 during a shared library init phase (code executed while executing
2620 their .init section). Previously, the breakpoint would have no effect.
2621 - GDB is now able to backtrace through the signal handler for
2622 non-threaded programs.
2624 PIE (Position Independent Executable) programs debugging is now supported.
2625 This includes debugging execution of PIC (Position Independent Code) shared
2626 libraries although for that, it should be possible to run such libraries as an
2629 *** Changes in GDB 7.0
2631 * GDB now has an interface for JIT compilation. Applications that
2632 dynamically generate code can create symbol files in memory and register
2633 them with GDB. For users, the feature should work transparently, and
2634 for JIT developers, the interface is documented in the GDB manual in the
2635 "JIT Compilation Interface" chapter.
2637 * Tracepoints may now be conditional. The syntax is as for
2638 breakpoints; either an "if" clause appended to the "trace" command,
2639 or the "condition" command is available. GDB sends the condition to
2640 the target for evaluation using the same bytecode format as is used
2641 for tracepoint actions.
2643 * The disassemble command now supports: an optional /r modifier, print the
2644 raw instructions in hex as well as in symbolic form, and an optional /m
2645 modifier to print mixed source+assembly.
2647 * Process record and replay
2649 In a architecture environment that supports ``process record and
2650 replay'', ``process record and replay'' target can record a log of
2651 the process execution, and replay it with both forward and reverse
2654 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2655 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2656 set execution-direction {forward|reverse}, for targets that support
2659 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2660 feature is available with a native GDB running on kernel version
2663 * GDB now has support for multi-byte and wide character sets on the
2664 target. Strings whose character type is wchar_t, char16_t, or
2665 char32_t are now correctly printed. GDB supports wide- and unicode-
2666 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2667 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2668 `printf'. This feature requires iconv to work properly; if your
2669 system does not have a working iconv, GDB can use GNU libiconv. See
2670 the installation instructions for more information.
2672 * GDB now supports automatic retrieval of shared library files from
2673 remote targets. To use this feature, specify a system root that begins
2674 with the `remote:' prefix, either via the `set sysroot' command or via
2675 the `--with-sysroot' configure-time option.
2677 * "info sharedlibrary" now takes an optional regex of libraries to show,
2678 and it now reports if a shared library has no debugging information.
2680 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2681 now complete on file names.
2683 * When completing in expressions, gdb will attempt to limit
2684 completions to allowable structure or union fields, where appropriate.
2685 For instance, consider:
2687 # struct example { int f1; double f2; };
2688 # struct example variable;
2691 If the user types TAB at the end of this command line, the available
2692 completions will be "f1" and "f2".
2694 * Inlined functions are now supported. They show up in backtraces, and
2695 the "step", "next", and "finish" commands handle them automatically.
2697 * GDB now supports the token-splicing (##) and stringification (#)
2698 operators when expanding macros. It also supports variable-arity
2701 * GDB now supports inspecting extra signal information, exported by
2702 the new $_siginfo convenience variable. The feature is currently
2703 implemented on linux ARM, i386 and amd64.
2705 * GDB can now display the VFP floating point registers and NEON vector
2706 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2707 can provide these registers (requires Linux 2.6.30 or later). Remote
2708 and simulator targets may also provide them.
2710 * New remote packets
2713 Search memory for a sequence of bytes.
2716 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2717 operation over reliable transport links. Use of this packet is
2718 controlled by the `set remote noack-packet' command.
2721 Kill the process with the specified process ID. Use this in preference
2722 to `k' when multiprocess protocol extensions are supported.
2725 Obtains additional operating system information
2729 Read or write additional signal information.
2731 * Removed remote protocol undocumented extension
2733 An undocumented extension to the remote protocol's `S' stop reply
2734 packet that permited the stub to pass a process id was removed.
2735 Remote servers should use the `T' stop reply packet instead.
2737 * GDB now supports multiple function calling conventions according to the
2738 DWARF-2 DW_AT_calling_convention function attribute.
2740 * The SH target utilizes the aforementioned change to distinguish between gcc
2741 and Renesas calling convention. It also adds the new CLI commands
2742 `set/show sh calling-convention'.
2744 * GDB can now read compressed debug sections, as produced by GNU gold
2745 with the --compress-debug-sections=zlib flag.
2747 * 64-bit core files are now supported on AIX.
2749 * Thread switching is now supported on Tru64.
2751 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2752 which will be allocated using malloc later in program execution.
2754 * The qXfer:libraries:read remote procotol packet now allows passing a
2755 list of section offsets.
2757 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2758 conditions handling signals delivered during attach or thread creation
2759 have also been fixed.
2761 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2762 From the user's standpoint, all unqualified instances of True and False
2763 are treated as the standard definitions, regardless of context.
2765 * GDB now parses C++ symbol and type names more flexibly. For
2768 template<typename T> class C { };
2771 GDB will now correctly handle all of:
2773 ptype C<char const *>
2774 ptype C<char const*>
2775 ptype C<const char *>
2776 ptype C<const char*>
2778 * New features in the GDB remote stub, gdbserver
2780 - The "--wrapper" command-line argument tells gdbserver to use a
2781 wrapper program to launch programs for debugging.
2783 - On PowerPC and S/390 targets, it is now possible to use a single
2784 gdbserver executable to debug both 32-bit and 64-bit programs.
2785 (This requires gdbserver itself to be built as a 64-bit executable.)
2787 - gdbserver uses the new noack protocol mode for TCP connections to
2788 reduce communications latency, if also supported and enabled in GDB.
2790 - Support for the sparc64-linux-gnu target is now included in
2793 - The amd64-linux build of gdbserver now supports debugging both
2794 32-bit and 64-bit programs.
2796 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2797 now support hardware watchpoints, and will use them automatically
2802 GDB now has support for scripting using Python. Whether this is
2803 available is determined at configure time.
2805 New GDB commands can now be written in Python.
2807 * Ada tasking support
2809 Ada tasks can now be inspected in GDB. The following commands have
2813 Print the list of Ada tasks.
2815 Print detailed information about task number N.
2817 Print the task number of the current task.
2819 Switch the context of debugging to task number N.
2821 * Support for user-defined prefixed commands. The "define" command can
2822 add new commands to existing prefixes, e.g. "target".
2824 * Multi-inferior, multi-process debugging.
2826 GDB now has generalized support for multi-inferior debugging. See
2827 "Debugging Multiple Inferiors" in the manual for more information.
2828 Although availability still depends on target support, the command
2829 set is more uniform now. The GNU/Linux specific multi-forks support
2830 has been migrated to this new framework. This implied some user
2831 visible changes; see "New commands" and also "Removed commands"
2834 * Target descriptions can now describe the target OS ABI. See the
2835 "Target Description Format" section in the user manual for more
2838 * Target descriptions can now describe "compatible" architectures
2839 to indicate that the target can execute applications for a different
2840 architecture in addition to those for the main target architecture.
2841 See the "Target Description Format" section in the user manual for
2844 * Multi-architecture debugging.
2846 GDB now includes general supports for debugging applications on
2847 hybrid systems that use more than one single processor architecture
2848 at the same time. Each such hybrid architecture still requires
2849 specific support to be added. The only hybrid architecture supported
2850 in this version of GDB is the Cell Broadband Engine.
2852 * GDB now supports integrated debugging of Cell/B.E. applications that
2853 use both the PPU and SPU architectures. To enable support for hybrid
2854 Cell/B.E. debugging, you need to configure GDB to support both the
2855 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2856 --enable-targets configure option.
2858 * Non-stop mode debugging.
2860 For some targets, GDB now supports an optional mode of operation in
2861 which you can examine stopped threads while other threads continue
2862 to execute freely. This is referred to as non-stop mode, with the
2863 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2864 section in the user manual for more information.
2866 To be able to support remote non-stop debugging, a remote stub needs
2867 to implement the non-stop mode remote protocol extensions, as
2868 described in the "Remote Non-Stop" section of the user manual. The
2869 GDB remote stub, gdbserver, has been adjusted to support these
2870 extensions on linux targets.
2872 * New commands (for set/show, see "New options" below)
2874 catch syscall [NAME(S) | NUMBER(S)]
2875 Catch system calls. Arguments, which should be names of system
2876 calls or their numbers, mean catch only those syscalls. Without
2877 arguments, every syscall will be caught. When the inferior issues
2878 any of the specified syscalls, GDB will stop and announce the system
2879 call, both when it is called and when its call returns. This
2880 feature is currently available with a native GDB running on the
2881 Linux Kernel, under the following architectures: x86, x86_64,
2882 PowerPC and PowerPC64.
2884 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2886 Search memory for a sequence of bytes.
2888 maint set python print-stack
2889 maint show python print-stack
2890 Show a stack trace when an error is encountered in a Python script.
2893 Invoke CODE by passing it to the Python interpreter.
2898 These allow macros to be defined, undefined, and listed
2902 Show operating system information about processes.
2905 List the inferiors currently under GDB's control.
2908 Switch focus to inferior number NUM.
2911 Detach from inferior number NUM.
2914 Kill inferior number NUM.
2918 set spu stop-on-load
2919 show spu stop-on-load
2920 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2922 set spu auto-flush-cache
2923 show spu auto-flush-cache
2924 Control whether to automatically flush the software-managed cache
2925 during Cell/B.E. debugging.
2927 set sh calling-convention
2928 show sh calling-convention
2929 Control the calling convention used when calling SH target functions.
2932 show debug timestamp
2933 Control display of timestamps with GDB debugging output.
2935 set disassemble-next-line
2936 show disassemble-next-line
2937 Control display of disassembled source lines or instructions when
2940 set remote noack-packet
2941 show remote noack-packet
2942 Set/show the use of remote protocol QStartNoAckMode packet. See above
2943 under "New remote packets."
2945 set remote query-attached-packet
2946 show remote query-attached-packet
2947 Control use of remote protocol `qAttached' (query-attached) packet.
2949 set remote read-siginfo-object
2950 show remote read-siginfo-object
2951 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2954 set remote write-siginfo-object
2955 show remote write-siginfo-object
2956 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2959 set remote reverse-continue
2960 show remote reverse-continue
2961 Control use of remote protocol 'bc' (reverse-continue) packet.
2963 set remote reverse-step
2964 show remote reverse-step
2965 Control use of remote protocol 'bs' (reverse-step) packet.
2967 set displaced-stepping
2968 show displaced-stepping
2969 Control displaced stepping mode. Displaced stepping is a way to
2970 single-step over breakpoints without removing them from the debuggee.
2971 Also known as "out-of-line single-stepping".
2974 show debug displaced
2975 Control display of debugging info for displaced stepping.
2977 maint set internal-error
2978 maint show internal-error
2979 Control what GDB does when an internal error is detected.
2981 maint set internal-warning
2982 maint show internal-warning
2983 Control what GDB does when an internal warning is detected.
2988 Use a wrapper program to launch programs for debugging.
2990 set multiple-symbols (all|ask|cancel)
2991 show multiple-symbols
2992 The value of this variable can be changed to adjust the debugger behavior
2993 when an expression or a breakpoint location contains an ambiguous symbol
2994 name (an overloaded function name, for instance).
2996 set breakpoint always-inserted
2997 show breakpoint always-inserted
2998 Keep breakpoints always inserted in the target, as opposed to inserting
2999 them when resuming the target, and removing them when the target stops.
3000 This option can improve debugger performance on slow remote targets.
3002 set arm fallback-mode (arm|thumb|auto)
3003 show arm fallback-mode
3004 set arm force-mode (arm|thumb|auto)
3006 These commands control how ARM GDB determines whether instructions
3007 are ARM or Thumb. The default for both settings is auto, which uses
3008 the current CPSR value for instructions without symbols; previous
3009 versions of GDB behaved as if "set arm fallback-mode arm".
3011 set disable-randomization
3012 show disable-randomization
3013 Standalone programs run with the virtual address space randomization enabled
3014 by default on some platforms. This option keeps the addresses stable across
3015 multiple debugging sessions.
3019 Control whether other threads are stopped or not when some thread hits
3024 Requests that asynchronous execution is enabled in the target, if available.
3025 In this case, it's possible to resume target in the background, and interact
3026 with GDB while the target is running. "show target-async" displays the
3027 current state of asynchronous execution of the target.
3029 set target-wide-charset
3030 show target-wide-charset
3031 The target-wide-charset is the name of the character set that GDB
3032 uses when printing characters whose type is wchar_t.
3034 set tcp auto-retry (on|off)
3036 set tcp connect-timeout
3037 show tcp connect-timeout
3038 These commands allow GDB to retry failed TCP connections to a remote stub
3039 with a specified timeout period; this is useful if the stub is launched
3040 in parallel with GDB but may not be ready to accept connections immediately.
3042 set libthread-db-search-path
3043 show libthread-db-search-path
3044 Control list of directories which GDB will search for appropriate
3047 set schedule-multiple (on|off)
3048 show schedule-multiple
3049 Allow GDB to resume all threads of all processes or only threads of
3050 the current process.
3054 Use more aggressive caching for accesses to the stack. This improves
3055 performance of remote debugging (particularly backtraces) without
3056 affecting correctness.
3058 set interactive-mode (on|off|auto)
3059 show interactive-mode
3060 Control whether GDB runs in interactive mode (on) or not (off).
3061 When in interactive mode, GDB waits for the user to answer all
3062 queries. Otherwise, GDB does not wait and assumes the default
3063 answer. When set to auto (the default), GDB determines which
3064 mode to use based on the stdin settings.
3069 For program forks, this is replaced by the new more generic `info
3070 inferiors' command. To list checkpoints, you can still use the
3071 `info checkpoints' command, which was an alias for the `info forks'
3075 Replaced by the new `inferior' command. To switch between
3076 checkpoints, you can still use the `restart' command, which was an
3077 alias for the `fork' command.
3080 This is removed, since some targets don't have a notion of
3081 processes. To switch between processes, you can still use the
3082 `inferior' command using GDB's own inferior number.
3085 For program forks, this is replaced by the new more generic `kill
3086 inferior' command. To delete a checkpoint, you can still use the
3087 `delete checkpoint' command, which was an alias for the `delete
3091 For program forks, this is replaced by the new more generic `detach
3092 inferior' command. To detach a checkpoint, you can still use the
3093 `detach checkpoint' command, which was an alias for the `detach
3096 * New native configurations
3098 x86/x86_64 Darwin i[34567]86-*-darwin*
3100 x86_64 MinGW x86_64-*-mingw*
3104 Lattice Mico32 lm32-*
3105 x86 DICOS i[34567]86-*-dicos*
3106 x86_64 DICOS x86_64-*-dicos*
3109 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3110 (mingw32ce) debugging.
3116 These commands were actually not implemented on any target.
3118 *** Changes in GDB 6.8
3120 * New native configurations
3122 NetBSD/hppa hppa*-*netbsd*
3123 Xtensa GNU/Linux xtensa*-*-linux*
3127 NetBSD/hppa hppa*-*-netbsd*
3128 Xtensa GNU/Lunux xtensa*-*-linux*
3130 * Change in command line behavior -- corefiles vs. process ids.
3132 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3133 attaching to process NUMBER fails, GDB no longer attempts to open a
3134 core file named NUMBER. Attaching to a program using the -c option
3135 is no longer supported. Instead, use the '-p' or '--pid' options.
3137 * GDB can now be built as a native debugger for debugging Windows x86
3138 (mingw32) Portable Executable (PE) programs.
3140 * Pending breakpoints no longer change their number when their address
3143 * GDB now supports breakpoints with multiple locations,
3144 including breakpoints on C++ constructors, inside C++ templates,
3145 and in inlined functions.
3147 * GDB's ability to debug optimized code has been improved. GDB more
3148 accurately identifies function bodies and lexical blocks that occupy
3149 more than one contiguous range of addresses.
3151 * Target descriptions can now describe registers for PowerPC.
3153 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3154 registers on PowerPC targets.
3156 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3157 targets even when the libthread_db library is not available.
3159 * The GDB remote stub, gdbserver, now supports the new file transfer
3160 commands (remote put, remote get, and remote delete).
3162 * The GDB remote stub, gdbserver, now supports run and attach in
3163 extended-remote mode.
3165 * hppa*64*-*-hpux11* target broken
3166 The debugger is unable to start a program and fails with the following
3167 error: "Error trying to get information about dynamic linker".
3168 The gdb-6.7 release is also affected.
3170 * GDB now supports the --enable-targets= configure option to allow
3171 building a single GDB executable that supports multiple remote
3172 target architectures.
3174 * GDB now supports debugging C and C++ programs which use the
3175 Decimal Floating Point extension. In addition, the PowerPC target
3176 now has a set of pseudo-registers to inspect decimal float values
3177 stored in two consecutive float registers.
3179 * The -break-insert MI command can optionally create pending
3182 * Improved support for debugging Ada
3183 Many improvements to the Ada language support have been made. These
3185 - Better support for Ada2005 interface types
3186 - Improved handling of arrays and slices in general
3187 - Better support for Taft-amendment types
3188 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3190 - Improved command completion in Ada
3193 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3198 set print frame-arguments (all|scalars|none)
3199 show print frame-arguments
3200 The value of this variable can be changed to control which argument
3201 values should be printed by the debugger when displaying a frame.
3206 Transfer files to and from a remote target, and delete remote files.
3213 Transfer files to and from a remote target, and delete remote files.
3215 * New remote packets
3222 Open, close, read, write, and delete files on the remote system.
3225 Attach to an existing process on the remote system, in extended-remote
3229 Run a new process on the remote system, in extended-remote mode.
3231 *** Changes in GDB 6.7
3233 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3234 bfd, libiberty and opcodes, as revealed by static analysis donated by
3235 Coverity, Inc. (http://scan.coverity.com).
3237 * When looking up multiply-defined global symbols, GDB will now prefer the
3238 symbol definition in the current shared library if it was built using the
3239 -Bsymbolic linker option.
3241 * When the Text User Interface (TUI) is not configured, GDB will now
3242 recognize the -tui command-line option and print a message that the TUI
3245 * The GDB remote stub, gdbserver, now has lower overhead for high
3246 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3248 * GDB for MIPS targets now autodetects whether a remote target provides
3249 32-bit or 64-bit register values.
3251 * Support for C++ member pointers has been improved.
3253 * GDB now understands XML target descriptions, which specify the
3254 target's overall architecture. GDB can read a description from
3255 a local file or over the remote serial protocol.
3257 * Vectors of single-byte data use a new integer type which is not
3258 automatically displayed as character or string data.
3260 * The /s format now works with the print command. It displays
3261 arrays of single-byte integers and pointers to single-byte integers
3264 * Target descriptions can now describe target-specific registers,
3265 for architectures which have implemented the support (currently
3266 only ARM, M68K, and MIPS).
3268 * GDB and the GDB remote stub, gdbserver, now support the XScale
3271 * The GDB remote stub, gdbserver, has been updated to support
3272 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3273 has been rewritten to use the standard GDB remote protocol.
3275 * GDB can now step into C++ functions which are called through thunks.
3277 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3279 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3280 layout. It also supports a TextSeg= and DataSeg= response when only
3281 segment base addresses (rather than offsets) are available.
3283 * The /i format now outputs any trailing branch delay slot instructions
3284 immediately following the last instruction within the count specified.
3286 * The GDB remote protocol "T" stop reply packet now supports a
3287 "library" response. Combined with the new "qXfer:libraries:read"
3288 packet, this response allows GDB to debug shared libraries on targets
3289 where the operating system manages the list of loaded libraries (e.g.
3290 Windows and SymbianOS).
3292 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3293 (DLLs) on Windows and Windows CE targets.
3295 * GDB now supports a faster verification that a .debug file matches its binary
3296 according to its build-id signature, if the signature is present.
3302 Enable or disable hardware flow control (RTS/CTS) on the serial port
3303 when debugging using remote targets.
3305 set mem inaccessible-by-default
3306 show mem inaccessible-by-default
3307 If the target supplies a memory map, for instance via the remote
3308 protocol's "qXfer:memory-map:read" packet, setting this variable
3309 prevents GDB from accessing memory outside the memory map. This
3310 is useful for targets with memory mapped registers or which react
3311 badly to accesses of unmapped address space.
3313 set breakpoint auto-hw
3314 show breakpoint auto-hw
3315 If the target supplies a memory map, for instance via the remote
3316 protocol's "qXfer:memory-map:read" packet, setting this variable
3317 lets GDB use hardware breakpoints automatically for memory regions
3318 where it can not use software breakpoints. This covers both the
3319 "break" command and internal breakpoints used for other commands
3320 including "next" and "finish".
3323 catch exception unhandled
3324 Stop the program execution when Ada exceptions are raised.
3327 Stop the program execution when an Ada assertion failed.
3331 Set an alternate system root for target files. This is a more
3332 general version of "set solib-absolute-prefix", which is now
3333 an alias to "set sysroot".
3336 Provide extended SPU facility status information. This set of
3337 commands is available only when debugging the Cell/B.E. SPU
3340 * New native configurations
3342 OpenBSD/sh sh*-*openbsd*
3345 unset tdesc filename
3347 Use the specified local file as an XML target description, and do
3348 not query the target for its built-in description.
3352 OpenBSD/sh sh*-*-openbsd*
3353 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3354 Toshiba Media Processor mep-elf
3356 * New remote packets
3359 Ignore the specified signals; pass them directly to the debugged program
3360 without stopping other threads or reporting them to GDB.
3362 qXfer:features:read:
3363 Read an XML target description from the target, which describes its
3368 Read or write contents of an spufs file on the target system. These
3369 packets are available only on the Cell/B.E. SPU architecture.
3371 qXfer:libraries:read:
3372 Report the loaded shared libraries. Combined with new "T" packet
3373 response, this packet allows GDB to debug shared libraries on
3374 targets where the operating system manages the list of loaded
3375 libraries (e.g. Windows and SymbianOS).
3379 Support for these obsolete configurations has been removed.
3387 i[34567]86-*-lynxos*
3388 i[34567]86-*-netware*
3389 i[34567]86-*-sco3.2v5*
3390 i[34567]86-*-sco3.2v4*
3392 i[34567]86-*-sysv4.2*
3395 i[34567]86-*-unixware2*
3396 i[34567]86-*-unixware*
3405 * Other removed features
3412 Various m68k-only ROM monitors.
3419 Various Renesas ROM monitors and debugging interfaces for SH and
3424 Support for a Macraigor serial interface to on-chip debugging.
3425 GDB does not directly support the newer parallel or USB
3430 A debug information format. The predecessor to DWARF 2 and
3431 DWARF 3, which are still supported.
3433 Support for the HP aCC compiler on HP-UX/PA-RISC
3435 SOM-encapsulated symbolic debugging information, automatic
3436 invocation of pxdb, and the aCC custom C++ ABI. This does not
3437 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3438 with aCC can still be debugged on an assembly level.
3440 MIPS ".pdr" sections
3442 A MIPS-specific format used to describe stack frame layout
3443 in debugging information.
3447 GDB could work with an older version of Guile to debug
3448 the interpreter and Scheme programs running in it.
3450 set mips stack-arg-size
3451 set mips saved-gpreg-size
3453 Use "set mips abi" to control parameter passing for MIPS.
3455 *** Changes in GDB 6.6
3460 Cell Broadband Engine SPU spu-elf
3462 * GDB can now be configured as a cross-debugger targeting native Windows
3463 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3464 running on a Windows system over TCP/IP to debug Windows programs.
3466 * The GDB remote stub, gdbserver, has been updated to support Windows and
3467 Cygwin debugging. Both single-threaded and multi-threaded programs are
3470 * The "set trust-readonly-sections" command works again. This command was
3471 broken in GDB 6.3, 6.4, and 6.5.
3473 * The "load" command now supports writing to flash memory, if the remote
3474 stub provides the required support.
3476 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3477 longer requires symbolic debug information (e.g. DWARF-2).
3482 unset substitute-path
3483 show substitute-path
3484 Manage a list of substitution rules that GDB uses to rewrite the name
3485 of the directories where the sources are located. This can be useful
3486 for instance when the sources were moved to a different location
3487 between compilation and debugging.
3491 Print each CLI command as it is executed. Each command is prefixed with
3492 a number of `+' symbols representing the nesting depth.
3493 The source command now has a `-v' option to enable the same feature.
3497 The ARM Demon monitor support (RDP protocol, "target rdp").
3499 Kernel Object Display, an embedded debugging feature which only worked with
3500 an obsolete version of Cisco IOS.
3502 The 'set download-write-size' and 'show download-write-size' commands.
3504 * New remote packets
3507 Tell a stub about GDB client features, and request remote target features.
3508 The first feature implemented is PacketSize, which allows the target to
3509 specify the size of packets it can handle - to minimize the number of
3510 packets required and improve performance when connected to a remote
3514 Fetch an OS auxilliary vector from the remote stub. This packet is a
3515 more efficient replacement for qPart:auxv:read.
3517 qXfer:memory-map:read:
3518 Fetch a memory map from the remote stub, including information about
3519 RAM, ROM, and flash memory devices.
3524 Erase and program a flash memory device.
3526 * Removed remote packets
3529 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3530 used it, and only gdbserver implemented it.
3532 *** Changes in GDB 6.5
3536 Renesas M32C/M16C m32c-elf
3538 Morpho Technologies ms1 ms1-elf
3542 init-if-undefined Initialize a convenience variable, but
3543 only if it doesn't already have a value.
3545 The following commands are presently only implemented for native GNU/Linux:
3547 checkpoint Save a snapshot of the program state.
3549 restart <n> Return the program state to a
3550 previously saved state.
3552 info checkpoints List currently saved checkpoints.
3554 delete-checkpoint <n> Delete a previously saved checkpoint.
3556 set|show detach-on-fork Tell gdb whether to detach from a newly
3557 forked process, or to keep debugging it.
3559 info forks List forks of the user program that
3560 are available to be debugged.
3562 fork <n> Switch to debugging one of several
3563 forks of the user program that are
3564 available to be debugged.
3566 delete-fork <n> Delete a fork from the list of forks
3567 that are available to be debugged (and
3568 kill the forked process).
3570 detach-fork <n> Delete a fork from the list of forks
3571 that are available to be debugged (and
3572 allow the process to continue).
3576 Morpho Technologies ms2 ms1-elf
3578 * Improved Windows host support
3580 GDB now builds as a cross debugger hosted on i686-mingw32, including
3581 native console support, and remote communications using either
3582 network sockets or serial ports.
3584 * Improved Modula-2 language support
3586 GDB can now print most types in the Modula-2 syntax. This includes:
3587 basic types, set types, record types, enumerated types, range types,
3588 pointer types and ARRAY types. Procedure var parameters are correctly
3589 printed and hexadecimal addresses and character constants are also
3590 written in the Modula-2 syntax. Best results can be obtained by using
3591 GNU Modula-2 together with the -gdwarf-2 command line option.
3595 The ARM rdi-share module.
3597 The Netware NLM debug server.
3599 *** Changes in GDB 6.4
3601 * New native configurations
3603 OpenBSD/arm arm*-*-openbsd*
3604 OpenBSD/mips64 mips64-*-openbsd*
3608 Morpho Technologies ms1 ms1-elf
3610 * New command line options
3612 --batch-silent As for --batch, but totally silent.
3613 --return-child-result The debugger will exist with the same value
3614 the child (debugged) program exited with.
3615 --eval-command COMMAND, -ex COMMAND
3616 Execute a single GDB CLI command. This may be
3617 specified multiple times and in conjunction
3618 with the --command (-x) option.
3620 * Deprecated commands removed
3622 The following commands, that were deprecated in 2000, have been
3626 set|show arm disassembly-flavor set|show arm disassembler
3627 othernames set arm disassembler
3628 set|show remotedebug set|show debug remote
3629 set|show archdebug set|show debug arch
3630 set|show eventdebug set|show debug event
3633 * New BSD user-level threads support
3635 It is now possible to debug programs using the user-level threads
3636 library on OpenBSD and FreeBSD. Currently supported (target)
3639 FreeBSD/amd64 x86_64-*-freebsd*
3640 FreeBSD/i386 i386-*-freebsd*
3641 OpenBSD/i386 i386-*-openbsd*
3643 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3644 are not yet supported.
3646 * New support for Matsushita MN10300 w/sim added
3647 (Work in progress). mn10300-elf.
3649 * REMOVED configurations and files
3651 VxWorks and the XDR protocol *-*-vxworks
3652 Motorola MCORE mcore-*-*
3653 National Semiconductor NS32000 ns32k-*-*
3655 * New "set print array-indexes" command
3657 After turning this setting "on", GDB prints the index of each element
3658 when displaying arrays. The default is "off" to preserve the previous
3661 * VAX floating point support
3663 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3665 * User-defined command support
3667 In addition to using $arg0..$arg9 for argument passing, it is now possible
3668 to use $argc to determine now many arguments have been passed. See the
3669 section on user-defined commands in the user manual for more information.
3671 *** Changes in GDB 6.3:
3673 * New command line option
3675 GDB now accepts -l followed by a number to set the timeout for remote
3678 * GDB works with GCC -feliminate-dwarf2-dups
3680 GDB now supports a more compact representation of DWARF-2 debug
3681 information using DW_FORM_ref_addr references. These are produced
3682 by GCC with the option -feliminate-dwarf2-dups and also by some
3683 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3684 to use -feliminate-dwarf2-dups.
3686 * Internationalization
3688 When supported by the host system, GDB will be built with
3689 internationalization (libintl). The task of marking up the sources is
3690 continued, we're looking forward to our first translation.
3694 Initial support for debugging programs compiled with the GNAT
3695 implementation of the Ada programming language has been integrated
3696 into GDB. In this release, support is limited to expression evaluation.
3698 * New native configurations
3700 GNU/Linux/m32r m32r-*-linux-gnu
3704 GDB's remote protocol now includes support for the 'p' packet. This
3705 packet is used to fetch individual registers from a remote inferior.
3707 * END-OF-LIFE registers[] compatibility module
3709 GDB's internal register infrastructure has been completely rewritten.
3710 The new infrastructure making possible the implementation of key new
3711 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3714 GDB 6.3 will be the last release to include the the registers[]
3715 compatibility module that allowed out-of-date configurations to
3716 continue to work. This change directly impacts the following
3726 powerpc bdm protocol
3728 Unless there is activity to revive these configurations, they will be
3729 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3731 * OBSOLETE configurations and files
3733 Configurations that have been declared obsolete in this release have
3734 been commented out. Unless there is activity to revive these
3735 configurations, the next release of GDB will have their sources
3736 permanently REMOVED.
3745 *** Changes in GDB 6.2.1:
3747 * MIPS `break main; run' gave an heuristic-fence-post warning
3749 When attempting to run even a simple program, a warning about
3750 heuristic-fence-post being hit would be reported. This problem has
3753 * MIPS IRIX 'long double' crashed GDB
3755 When examining a long double variable, GDB would get a segmentation
3756 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3757 IRIX long double values).
3761 A bug in the VAX stack code was causing problems with the "next"
3762 command. This problem has been fixed.
3764 *** Changes in GDB 6.2:
3766 * Fix for ``many threads''
3768 On GNU/Linux systems that use the NPTL threads library, a program
3769 rapidly creating and deleting threads would confuse GDB leading to the
3772 ptrace: No such process.
3773 thread_db_get_info: cannot get thread info: generic error
3775 This problem has been fixed.
3777 * "-async" and "-noasync" options removed.
3779 Support for the broken "-noasync" option has been removed (it caused
3782 * New ``start'' command.
3784 This command runs the program until the begining of the main procedure.
3786 * New BSD Kernel Data Access Library (libkvm) interface
3788 Using ``target kvm'' it is now possible to debug kernel core dumps and
3789 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3790 platforms. Currently supported (native-only) configurations are:
3792 FreeBSD/amd64 x86_64-*-freebsd*
3793 FreeBSD/i386 i?86-*-freebsd*
3794 NetBSD/i386 i?86-*-netbsd*
3795 NetBSD/m68k m68*-*-netbsd*
3796 NetBSD/sparc sparc-*-netbsd*
3797 OpenBSD/amd64 x86_64-*-openbsd*
3798 OpenBSD/i386 i?86-*-openbsd*
3799 OpenBSD/m68k m68*-openbsd*
3800 OpenBSD/sparc sparc-*-openbsd*
3802 * Signal trampoline code overhauled
3804 Many generic problems with GDB's signal handling code have been fixed.
3805 These include: backtraces through non-contiguous stacks; recognition
3806 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3807 call; backtrace through a signal trampoline; step into and out of
3808 signal handlers; and single-stepping in the signal trampoline.
3810 Please note that kernel bugs are a limiting factor here. These
3811 features have been shown to work on an s390 GNU/Linux system that
3812 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3814 * Cygwin support for DWARF 2 added.
3816 * New native configurations
3818 GNU/Linux/hppa hppa*-*-linux*
3819 OpenBSD/hppa hppa*-*-openbsd*
3820 OpenBSD/m68k m68*-*-openbsd*
3821 OpenBSD/m88k m88*-*-openbsd*
3822 OpenBSD/powerpc powerpc-*-openbsd*
3823 NetBSD/vax vax-*-netbsd*
3824 OpenBSD/vax vax-*-openbsd*
3826 * END-OF-LIFE frame compatibility module
3828 GDB's internal frame infrastructure has been completely rewritten.
3829 The new infrastructure making it possible to support key new features
3830 including DWARF 2 Call Frame Information. To aid in the task of
3831 migrating old configurations to this new infrastructure, a
3832 compatibility module, that allowed old configurations to continue to
3833 work, was also included.
3835 GDB 6.2 will be the last release to include this frame compatibility
3836 module. This change directly impacts the following configurations:
3846 Unless there is activity to revive these configurations, they will be
3847 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3849 * REMOVED configurations and files
3851 Sun 3, running SunOS 3 m68*-*-sunos3*
3852 Sun 3, running SunOS 4 m68*-*-sunos4*
3853 Sun 2, running SunOS 3 m68000-*-sunos3*
3854 Sun 2, running SunOS 4 m68000-*-sunos4*
3855 Motorola 680x0 running LynxOS m68*-*-lynxos*
3856 AT&T 3b1/Unix pc m68*-att-*
3857 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3858 decstation mips-dec-* mips-little-*
3859 riscos mips-*-riscos* mips-*-sysv*
3860 sonymips mips-sony-*
3861 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3863 *** Changes in GDB 6.1.1:
3865 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3867 The TUI (Text-mode User Interface) is now built as part of a default
3868 GDB configuration. It is enabled by either selecting the TUI with the
3869 command line option "-i=tui" or by running the separate "gdbtui"
3870 program. For more information on the TUI, see the manual "Debugging
3873 * Pending breakpoint support (also included in GDB 6.1)
3875 Support has been added to allow you to specify breakpoints in shared
3876 libraries that have not yet been loaded. If a breakpoint location
3877 cannot be found, and the "breakpoint pending" option is set to auto,
3878 GDB queries you if you wish to make the breakpoint pending on a future
3879 shared-library load. If and when GDB resolves the breakpoint symbol,
3880 the pending breakpoint is removed as one or more regular breakpoints
3883 Pending breakpoints are very useful for GCJ Java debugging.
3885 * Fixed ISO-C build problems
3887 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3888 non ISO-C code that stopped them being built using a more strict ISO-C
3889 compiler (e.g., IBM's C compiler).
3891 * Fixed build problem on IRIX 5
3893 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3894 wasn't able to compile compile on an IRIX 5 system.
3896 * Added execute permission to gdb/gdbserver/configure
3898 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3899 permission. This bug would cause configure to fail on a number of
3900 systems (Solaris, IRIX). Ref: server/519.
3902 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3904 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3905 has been updated to use constant array sizes.
3907 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3909 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3910 its generated DWARF Call Frame Info. This encoding was causing GDB to
3911 panic, that panic has been fixed. Ref: gdb/1628.
3913 * Fixed a problem when examining parameters in shared library code.
3915 When examining parameters in optimized shared library code generated
3916 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3917 not available''. GDB now correctly displays the variable's value.
3919 *** Changes in GDB 6.1:
3921 * Removed --with-mmalloc
3923 Support for the mmalloc memory manager has been removed, as it
3924 conflicted with the internal gdb byte cache.
3926 * Changes in AMD64 configurations
3928 The AMD64 target now includes the %cs and %ss registers. As a result
3929 the AMD64 remote protocol has changed; this affects the floating-point
3930 and SSE registers. If you rely on those registers for your debugging,
3931 you should upgrade gdbserver on the remote side.
3933 * Revised SPARC target
3935 The SPARC target has been completely revised, incorporating the
3936 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3937 support for LynxOS and SunOS 4 has been dropped. Calling functions
3938 from within GDB on operating systems with a non-executable stack
3939 (Solaris, OpenBSD) now works.
3943 GDB has a new C++ demangler which does a better job on the mangled
3944 names generated by current versions of g++. It also runs faster, so
3945 with this and other changes gdb should now start faster on large C++
3948 * DWARF 2 Location Expressions
3950 GDB support for location expressions has been extended to support function
3951 arguments and frame bases. Older versions of GDB could crash when they
3954 * C++ nested types and namespaces
3956 GDB's support for nested types and namespaces in C++ has been
3957 improved, especially if you use the DWARF 2 debugging format. (This
3958 is the default for recent versions of GCC on most platforms.)
3959 Specifically, if you have a class "Inner" defined within a class or
3960 namespace "Outer", then GDB realizes that the class's name is
3961 "Outer::Inner", not simply "Inner". This should greatly reduce the
3962 frequency of complaints about not finding RTTI symbols. In addition,
3963 if you are stopped at inside of a function defined within a namespace,
3964 GDB modifies its name lookup accordingly.
3966 * New native configurations
3968 NetBSD/amd64 x86_64-*-netbsd*
3969 OpenBSD/amd64 x86_64-*-openbsd*
3970 OpenBSD/alpha alpha*-*-openbsd*
3971 OpenBSD/sparc sparc-*-openbsd*
3972 OpenBSD/sparc64 sparc64-*-openbsd*
3974 * New debugging protocols
3976 M32R with SDI protocol m32r-*-elf*
3978 * "set prompt-escape-char" command deleted.
3980 The command "set prompt-escape-char" has been deleted. This command,
3981 and its very obscure effet on GDB's prompt, was never documented,
3982 tested, nor mentioned in the NEWS file.
3984 * OBSOLETE configurations and files
3986 Configurations that have been declared obsolete in this release have
3987 been commented out. Unless there is activity to revive these
3988 configurations, the next release of GDB will have their sources
3989 permanently REMOVED.
3991 Sun 3, running SunOS 3 m68*-*-sunos3*
3992 Sun 3, running SunOS 4 m68*-*-sunos4*
3993 Sun 2, running SunOS 3 m68000-*-sunos3*
3994 Sun 2, running SunOS 4 m68000-*-sunos4*
3995 Motorola 680x0 running LynxOS m68*-*-lynxos*
3996 AT&T 3b1/Unix pc m68*-att-*
3997 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3998 decstation mips-dec-* mips-little-*
3999 riscos mips-*-riscos* mips-*-sysv*
4000 sonymips mips-sony-*
4001 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4003 * REMOVED configurations and files
4005 SGI Irix-4.x mips-sgi-irix4 or iris4
4006 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4007 Z8000 simulator z8k-zilog-none or z8ksim
4008 Matsushita MN10200 w/simulator mn10200-*-*
4009 H8/500 simulator h8500-hitachi-hms or h8500hms
4010 HP/PA running BSD hppa*-*-bsd*
4011 HP/PA running OSF/1 hppa*-*-osf*
4012 HP/PA Pro target hppa*-*-pro*
4013 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4014 386BSD i[3456]86-*-bsd*
4015 Sequent family i[3456]86-sequent-sysv4*
4016 i[3456]86-sequent-sysv*
4017 i[3456]86-sequent-bsd*
4018 SPARC running LynxOS sparc-*-lynxos*
4019 SPARC running SunOS 4 sparc-*-sunos4*
4020 Tsqware Sparclet sparclet-*-*
4021 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4023 *** Changes in GDB 6.0:
4027 Support for debugging the Objective-C programming language has been
4028 integrated into GDB.
4030 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4032 DWARF 2's Call Frame Information makes available compiler generated
4033 information that more exactly describes the program's run-time stack.
4034 By using this information, GDB is able to provide more robust stack
4037 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4038 have been updated to use a new backtrace mechanism which includes
4039 DWARF 2 CFI support.
4043 GDB's remote protocol has been extended to include support for hosted
4044 file I/O (where the remote target uses GDB's file system). See GDB's
4045 remote protocol documentation for details.
4047 * All targets using the new architecture framework.
4049 All of GDB's targets have been updated to use the new internal
4050 architecture framework. The way is now open for future GDB releases
4051 to include cross-architecture native debugging support (i386 on amd64,
4054 * GNU/Linux's Thread Local Storage (TLS)
4056 GDB now includes support for for the GNU/Linux implementation of
4057 per-thread variables.
4059 * GNU/Linux's Native POSIX Thread Library (NPTL)
4061 GDB's thread code has been updated to work with either the new
4062 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4064 * Separate debug info.
4066 GDB, in conjunction with BINUTILS, now supports a mechanism for
4067 automatically loading debug information from a separate file. Instead
4068 of shipping full debug and non-debug versions of system libraries,
4069 system integrators can now instead ship just the stripped libraries
4070 and optional debug files.
4072 * DWARF 2 Location Expressions
4074 DWARF 2 Location Expressions allow the compiler to more completely
4075 describe the location of variables (even in optimized code) to the
4078 GDB now includes preliminary support for location expressions (support
4079 for DW_OP_piece is still missing).
4083 A number of long standing bugs that caused GDB to die while starting a
4084 Java application have been fixed. GDB's Java support is now
4085 considered "useable".
4087 * GNU/Linux support for fork, vfork, and exec.
4089 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4090 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4093 * GDB supports logging output to a file
4095 There are two new commands, "set logging" and "show logging", which can be
4096 used to capture GDB's output to a file.
4098 * The meaning of "detach" has changed for gdbserver
4100 The "detach" command will now resume the application, as documented. To
4101 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4104 * d10v, m68hc11 `regs' command deprecated
4106 The `info registers' command has been updated so that it displays the
4107 registers using a format identical to the old `regs' command.
4111 A new command, "maint set profile on/off", has been added. This command can
4112 be used to enable or disable profiling while running GDB, to profile a
4113 session or a set of commands. In addition there is a new configure switch,
4114 "--enable-profiling", which will cause GDB to be compiled with profiling
4115 data, for more informative profiling results.
4117 * Default MI syntax changed to "mi2".
4119 The default MI (machine interface) syntax, enabled by the command line
4120 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4121 "mi1", can be enabled by specifying the option "-i=mi1".
4123 Support for the original "mi0" syntax (included in GDB 5.0) has been
4126 Fix for gdb/192: removed extraneous space when displaying frame level.
4127 Fix for gdb/672: update changelist is now output in mi list format.
4128 Fix for gdb/702: a -var-assign that updates the value now shows up
4129 in a subsequent -var-update.
4131 * New native configurations.
4133 FreeBSD/amd64 x86_64-*-freebsd*
4135 * Multi-arched targets.
4137 HP/PA HPUX11 hppa*-*-hpux*
4138 Renesas M32R/D w/simulator m32r-*-elf*
4140 * OBSOLETE configurations and files
4142 Configurations that have been declared obsolete in this release have
4143 been commented out. Unless there is activity to revive these
4144 configurations, the next release of GDB will have their sources
4145 permanently REMOVED.
4147 Z8000 simulator z8k-zilog-none or z8ksim
4148 Matsushita MN10200 w/simulator mn10200-*-*
4149 H8/500 simulator h8500-hitachi-hms or h8500hms
4150 HP/PA running BSD hppa*-*-bsd*
4151 HP/PA running OSF/1 hppa*-*-osf*
4152 HP/PA Pro target hppa*-*-pro*
4153 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4154 Sequent family i[3456]86-sequent-sysv4*
4155 i[3456]86-sequent-sysv*
4156 i[3456]86-sequent-bsd*
4157 Tsqware Sparclet sparclet-*-*
4158 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4160 * REMOVED configurations and files
4163 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4164 IBM AIX PS/2 i[3456]86-*-aix
4165 i386 running Mach 3.0 i[3456]86-*-mach3*
4166 i386 running Mach i[3456]86-*-mach*
4167 i386 running OSF/1 i[3456]86-*osf1mk*
4168 HP/Apollo 68k Family m68*-apollo*-sysv*,
4170 m68*-hp-bsd*, m68*-hp-hpux*
4171 Argonaut Risc Chip (ARC) arc-*-*
4172 Mitsubishi D30V d30v-*-*
4173 Fujitsu FR30 fr30-*-elf*
4174 OS/9000 i[34]86-*-os9k
4175 I960 with MON960 i960-*-coff
4177 * MIPS $fp behavior changed
4179 The convenience variable $fp, for the MIPS, now consistently returns
4180 the address of the current frame's base. Previously, depending on the
4181 context, $fp could refer to either $sp or the current frame's base
4182 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4183 The GNU Source-Level Debugger''.
4185 *** Changes in GDB 5.3:
4187 * GNU/Linux shared library multi-threaded performance improved.
4189 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4190 `/proc', in preference to `ptrace' for memory reads. This may result
4191 in an improvement in the start-up time of multi-threaded, shared
4192 library applications when run under GDB. One GDB user writes: ``loads
4193 shared libs like mad''.
4195 * ``gdbserver'' now supports multi-threaded applications on some targets
4197 Support for debugging multi-threaded applications which use
4198 the GNU/Linux LinuxThreads package has been added for
4199 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4200 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4202 * GDB now supports C/C++ preprocessor macros.
4204 GDB now expands preprocessor macro invocations in C/C++ expressions,
4205 and provides various commands for showing macro definitions and how
4208 The new command `macro expand EXPRESSION' expands any macro
4209 invocations in expression, and shows the result.
4211 The new command `show macro MACRO-NAME' shows the definition of the
4212 macro named MACRO-NAME, and where it was defined.
4214 Most compilers don't include information about macros in the debugging
4215 information by default. In GCC 3.1, for example, you need to compile
4216 your program with the options `-gdwarf-2 -g3'. If the macro
4217 information is present in the executable, GDB will read it.
4219 * Multi-arched targets.
4221 DEC Alpha (partial) alpha*-*-*
4222 DEC VAX (partial) vax-*-*
4224 National Semiconductor NS32000 (partial) ns32k-*-*
4225 Motorola 68000 (partial) m68k-*-*
4226 Motorola MCORE mcore-*-*
4230 Fujitsu FRV architecture added by Red Hat frv*-*-*
4233 * New native configurations
4235 Alpha NetBSD alpha*-*-netbsd*
4236 SH NetBSD sh*-*-netbsdelf*
4237 MIPS NetBSD mips*-*-netbsd*
4238 UltraSPARC NetBSD sparc64-*-netbsd*
4240 * OBSOLETE configurations and files
4242 Configurations that have been declared obsolete in this release have
4243 been commented out. Unless there is activity to revive these
4244 configurations, the next release of GDB will have their sources
4245 permanently REMOVED.
4247 Mitsubishi D30V d30v-*-*
4248 OS/9000 i[34]86-*-os9k
4249 IBM AIX PS/2 i[3456]86-*-aix
4250 Fujitsu FR30 fr30-*-elf*
4251 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4252 Argonaut Risc Chip (ARC) arc-*-*
4253 i386 running Mach 3.0 i[3456]86-*-mach3*
4254 i386 running Mach i[3456]86-*-mach*
4255 i386 running OSF/1 i[3456]86-*osf1mk*
4256 HP/Apollo 68k Family m68*-apollo*-sysv*,
4258 m68*-hp-bsd*, m68*-hp-hpux*
4259 I960 with MON960 i960-*-coff
4261 * OBSOLETE languages
4263 CHILL, a Pascal like language used by telecommunications companies.
4265 * REMOVED configurations and files
4267 AMD 29k family via UDI a29k-amd-udi, udi29k
4268 A29K VxWorks a29k-*-vxworks
4269 AMD 29000 embedded, using EBMON a29k-none-none
4270 AMD 29000 embedded with COFF a29k-none-coff
4271 AMD 29000 embedded with a.out a29k-none-aout
4273 testsuite/gdb.hp/gdb.threads-hp/ directory
4275 * New command "set max-user-call-depth <nnn>"
4277 This command allows the user to limit the call depth of user-defined
4278 commands. The default is 1024.
4280 * Changes in FreeBSD/i386 native debugging.
4282 Support for the "generate-core-file" has been added.
4284 * New commands "dump", "append", and "restore".
4286 These commands allow data to be copied from target memory
4287 to a bfd-format or binary file (dump and append), and back
4288 from a file into memory (restore).
4290 * Improved "next/step" support on multi-processor Alpha Tru64.
4292 The previous single-step mechanism could cause unpredictable problems,
4293 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4294 of a software single-step mechanism prevents this.
4296 *** Changes in GDB 5.2.1:
4304 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4305 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4306 Fix, by Joel Brobecker imported from mainline.
4308 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4309 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4310 Fix, by Fred Fish, imported from mainline.
4312 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4313 Surprisingly enough, it works now.
4314 By Michal Ludvig, imported from mainline.
4316 i386 hardware watchpoint support:
4317 avoid misses on second run for some targets.
4318 By Pierre Muller, imported from mainline.
4320 *** Changes in GDB 5.2:
4322 * New command "set trust-readonly-sections on[off]".
4324 This command is a hint that tells gdb that read-only sections
4325 really are read-only (ie. that their contents will not change).
4326 In this mode, gdb will go to the object file rather than the
4327 target to read memory from read-only sections (such as ".text").
4328 This can be a significant performance improvement on some
4329 (notably embedded) targets.
4331 * New command "generate-core-file" (or "gcore").
4333 This new gdb command allows the user to drop a core file of the child
4334 process state at any time. So far it's been implemented only for
4335 GNU/Linux and Solaris, but should be relatively easily ported to other
4336 hosts. Argument is core file name (defaults to core.<pid>).
4338 * New command line option
4340 GDB now accepts --pid or -p followed by a process id.
4342 * Change in command line behavior -- corefiles vs. process ids.
4344 There is a subtle behavior in the way in which GDB handles
4345 command line arguments. The first non-flag argument is always
4346 a program to debug, but the second non-flag argument may either
4347 be a corefile or a process id. Previously, GDB would attempt to
4348 open the second argument as a corefile, and if that failed, would
4349 issue a superfluous error message and then attempt to attach it as
4350 a process. Now, if the second argument begins with a non-digit,
4351 it will be treated as a corefile. If it begins with a digit,
4352 GDB will attempt to attach it as a process, and if no such process
4353 is found, will then attempt to open it as a corefile.
4355 * Changes in ARM configurations.
4357 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4358 configuration is fully multi-arch.
4360 * New native configurations
4362 ARM NetBSD arm*-*-netbsd*
4363 x86 OpenBSD i[3456]86-*-openbsd*
4364 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4365 Sparc64 running FreeBSD sparc64-*-freebsd*
4369 Sanyo XStormy16 xstormy16-elf
4371 * OBSOLETE configurations and files
4373 Configurations that have been declared obsolete in this release have
4374 been commented out. Unless there is activity to revive these
4375 configurations, the next release of GDB will have their sources
4376 permanently REMOVED.
4378 AMD 29k family via UDI a29k-amd-udi, udi29k
4379 A29K VxWorks a29k-*-vxworks
4380 AMD 29000 embedded, using EBMON a29k-none-none
4381 AMD 29000 embedded with COFF a29k-none-coff
4382 AMD 29000 embedded with a.out a29k-none-aout
4384 testsuite/gdb.hp/gdb.threads-hp/ directory
4386 * REMOVED configurations and files
4388 TI TMS320C80 tic80-*-*
4390 PowerPC Solaris powerpcle-*-solaris*
4391 PowerPC Windows NT powerpcle-*-cygwin32
4392 PowerPC Netware powerpc-*-netware*
4393 Harris/CXUX m88k m88*-harris-cxux*
4394 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4395 ns32k-utek-sysv* ns32k-utek-*
4396 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4397 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4398 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4399 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4400 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4402 * Changes to command line processing
4404 The new `--args' feature can be used to specify command-line arguments
4405 for the inferior from gdb's command line.
4407 * Changes to key bindings
4409 There is a new `operate-and-get-next' function bound to `C-o'.
4411 *** Changes in GDB 5.1.1
4413 Fix compile problem on DJGPP.
4415 Fix a problem with floating-point registers on the i386 being
4418 Fix to stop GDB crashing on .debug_str debug info.
4420 Numerous documentation fixes.
4422 Numerous testsuite fixes.
4424 *** Changes in GDB 5.1:
4426 * New native configurations
4428 Alpha FreeBSD alpha*-*-freebsd*
4429 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4430 MIPS GNU/Linux mips*-*-linux*
4431 MIPS SGI Irix 6.x mips*-sgi-irix6*
4432 ia64 AIX ia64-*-aix*
4433 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4437 Motorola 68HC11 and 68HC12 m68hc11-elf
4439 UltraSparc running GNU/Linux sparc64-*-linux*
4441 * OBSOLETE configurations and files
4443 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4444 Harris/CXUX m88k m88*-harris-cxux*
4445 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4446 ns32k-utek-sysv* ns32k-utek-*
4447 TI TMS320C80 tic80-*-*
4449 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4450 PowerPC Solaris powerpcle-*-solaris*
4451 PowerPC Windows NT powerpcle-*-cygwin32
4452 PowerPC Netware powerpc-*-netware*
4453 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4454 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4455 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4456 Apple Macintosh (MPW) host N/A
4458 stuff.c (Program to stuff files into a specially prepared space in kdb)
4459 kdb-start.c (Main loop for the standalone kernel debugger)
4461 Configurations that have been declared obsolete in this release have
4462 been commented out. Unless there is activity to revive these
4463 configurations, the next release of GDB will have their sources
4464 permanently REMOVED.
4466 * REMOVED configurations and files
4468 Altos 3068 m68*-altos-*
4469 Convex c1-*-*, c2-*-*
4471 ARM RISCix arm-*-* (as host)
4475 * GDB has been converted to ISO C.
4477 GDB's source code has been converted to ISO C. In particular, the
4478 sources are fully protoized, and rely on standard headers being
4483 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4485 * The MI enabled by default.
4487 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4488 revised and enabled by default. Packages which use GDB as a debugging
4489 engine behind a UI or another front end are encouraged to switch to
4490 using the GDB/MI interface, instead of the old annotations interface
4491 which is now deprecated.
4493 * Support for debugging Pascal programs.
4495 GDB now includes support for debugging Pascal programs. The following
4496 main features are supported:
4498 - Pascal-specific data types such as sets;
4500 - automatic recognition of Pascal sources based on file-name
4503 - Pascal-style display of data types, variables, and functions;
4505 - a Pascal expression parser.
4507 However, some important features are not yet supported.
4509 - Pascal string operations are not supported at all;
4511 - there are some problems with boolean types;
4513 - Pascal type hexadecimal constants are not supported
4514 because they conflict with the internal variables format;
4516 - support for Pascal objects and classes is not full yet;
4518 - unlike Pascal, GDB is case-sensitive for symbol names.
4520 * Changes in completion.
4522 Commands such as `shell', `run' and `set args', which pass arguments
4523 to inferior programs, now complete on file names, similar to what
4524 users expect at the shell prompt.
4526 Commands which accept locations, such as `disassemble', `print',
4527 `breakpoint', `until', etc. now complete on filenames as well as
4528 program symbols. Thus, if you type "break foob TAB", and the source
4529 files linked into the programs include `foobar.c', that file name will
4530 be one of the candidates for completion. However, file names are not
4531 considered for completion after you typed a colon that delimits a file
4532 name from a name of a function in that file, as in "break foo.c:bar".
4534 `set demangle-style' completes on available demangling styles.
4536 * New platform-independent commands:
4538 It is now possible to define a post-hook for a command as well as a
4539 hook that runs before the command. For more details, see the
4540 documentation of `hookpost' in the GDB manual.
4542 * Changes in GNU/Linux native debugging.
4544 Support for debugging multi-threaded programs has been completely
4545 revised for all platforms except m68k and sparc. You can now debug as
4546 many threads as your system allows you to have.
4548 Attach/detach is supported for multi-threaded programs.
4550 Support for SSE registers was added for x86. This doesn't work for
4551 multi-threaded programs though.
4553 * Changes in MIPS configurations.
4555 Multi-arch support is enabled for all MIPS configurations.
4557 GDB can now be built as native debugger on SGI Irix 6.x systems for
4558 debugging n32 executables. (Debugging 64-bit executables is not yet
4561 * Unified support for hardware watchpoints in all x86 configurations.
4563 Most (if not all) native x86 configurations support hardware-assisted
4564 breakpoints and watchpoints in a unified manner. This support
4565 implements debug register sharing between watchpoints, which allows to
4566 put a virtually infinite number of watchpoints on the same address,
4567 and also supports watching regions up to 16 bytes with several debug
4570 The new maintenance command `maintenance show-debug-regs' toggles
4571 debugging print-outs in functions that insert, remove, and test
4572 watchpoints and hardware breakpoints.
4574 * Changes in the DJGPP native configuration.
4576 New command ``info dos sysinfo'' displays assorted information about
4577 the CPU, OS, memory, and DPMI server.
4579 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4580 display information about segment descriptors stored in GDT, LDT, and
4583 New commands ``info dos pde'' and ``info dos pte'' display entries
4584 from Page Directory and Page Tables (for now works with CWSDPMI only).
4585 New command ``info dos address-pte'' displays the Page Table entry for
4586 a given linear address.
4588 GDB can now pass command lines longer than 126 characters to the
4589 program being debugged (requires an update to the libdbg.a library
4590 which is part of the DJGPP development kit).
4592 DWARF2 debug info is now supported.
4594 It is now possible to `step' and `next' through calls to `longjmp'.
4596 * Changes in documentation.
4598 All GDB documentation was converted to GFDL, the GNU Free
4599 Documentation License.
4601 Tracepoints-related commands are now fully documented in the GDB
4604 TUI, the Text-mode User Interface, is now documented in the manual.
4606 Tracepoints-related commands are now fully documented in the GDB
4609 The "GDB Internals" manual now has an index. It also includes
4610 documentation of `ui_out' functions, GDB coding standards, x86
4611 hardware watchpoints, and memory region attributes.
4613 * GDB's version number moved to ``version.in''
4615 The Makefile variable VERSION has been replaced by the file
4616 ``version.in''. People creating GDB distributions should update the
4617 contents of this file.
4621 GUD support is now a standard part of the EMACS distribution.
4623 *** Changes in GDB 5.0:
4625 * Improved support for debugging FP programs on x86 targets
4627 Unified and much-improved support for debugging floating-point
4628 programs on all x86 targets. In particular, ``info float'' now
4629 displays the FP registers in the same format on all x86 targets, with
4630 greater level of detail.
4632 * Improvements and bugfixes in hardware-assisted watchpoints
4634 It is now possible to watch array elements, struct members, and
4635 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4636 on x86 targets no longer erroneously trigger when the address is
4639 * Improvements in the native DJGPP version of GDB
4641 The distribution now includes all the scripts and auxiliary files
4642 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4643 machines ``out of the box''.
4645 The DJGPP version can now debug programs that use signals. It is
4646 possible to catch signals that happened in the debuggee, deliver
4647 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4648 would kill the program being debugged.) Programs that hook hardware
4649 interrupts (keyboard, timer, etc.) can also be debugged.
4651 It is now possible to debug DJGPP programs that redirect their
4652 standard handles or switch them to raw (as opposed to cooked) mode, or
4653 even close them. The command ``run < foo > bar'' works as expected,
4654 and ``info terminal'' reports useful information about the debuggee's
4655 terminal, including raw/cooked mode, redirection, etc.
4657 The DJGPP version now uses termios functions for console I/O, which
4658 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4661 DOS-style file names with drive letters are now fully supported by
4664 It is now possible to debug DJGPP programs that switch their working
4665 directory. It is also possible to rerun the debuggee any number of
4666 times without restarting GDB; thus, you can use the same setup,
4667 breakpoints, etc. for many debugging sessions.
4669 * New native configurations
4671 ARM GNU/Linux arm*-*-linux*
4672 PowerPC GNU/Linux powerpc-*-linux*
4676 Motorola MCore mcore-*-*
4677 x86 VxWorks i[3456]86-*-vxworks*
4678 PowerPC VxWorks powerpc-*-vxworks*
4679 TI TMS320C80 tic80-*-*
4681 * OBSOLETE configurations
4683 Altos 3068 m68*-altos-*
4684 Convex c1-*-*, c2-*-*
4686 ARM RISCix arm-*-* (as host)
4689 Configurations that have been declared obsolete will be commented out,
4690 but the code will be left in place. If there is no activity to revive
4691 these configurations before the next release of GDB, the sources will
4692 be permanently REMOVED.
4694 * Gould support removed
4696 Support for the Gould PowerNode and NP1 has been removed.
4698 * New features for SVR4
4700 On SVR4 native platforms (such as Solaris), if you attach to a process
4701 without first loading a symbol file, GDB will now attempt to locate and
4702 load symbols from the running process's executable file.
4704 * Many C++ enhancements
4706 C++ support has been greatly improved. Overload resolution now works properly
4707 in almost all cases. RTTI support is on the way.
4709 * Remote targets can connect to a sub-program
4711 A popen(3) style serial-device has been added. This device starts a
4712 sub-process (such as a stand-alone simulator) and then communicates
4713 with that. The sub-program to run is specified using the syntax
4714 ``|<program> <args>'' vis:
4716 (gdb) set remotedebug 1
4717 (gdb) target extended-remote |mn10300-elf-sim program-args
4719 * MIPS 64 remote protocol
4721 A long standing bug in the mips64 remote protocol where by GDB
4722 expected certain 32 bit registers (ex SR) to be transfered as 32
4723 instead of 64 bits has been fixed.
4725 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4726 added to provide backward compatibility with older versions of GDB.
4728 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4730 The command ``set remotebinarydownload'' command has been replaced by
4731 ``set remote X-packet''. Other commands in ``set remote'' family
4732 include ``set remote P-packet''.
4734 * Breakpoint commands accept ranges.
4736 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4737 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4738 ``tracepoint passcount'' also accepts a range of tracepoints.
4740 * ``apropos'' command added.
4742 The ``apropos'' command searches through command names and
4743 documentation strings, printing out matches, making it much easier to
4744 try to find a command that does what you are looking for.
4748 A new machine oriented interface (MI) has been added to GDB. This
4749 interface is designed for debug environments running GDB as a separate
4750 process. This is part of the long term libGDB project. See the
4751 "GDB/MI" chapter of the GDB manual for further information. It can be
4752 enabled by configuring with:
4754 .../configure --enable-gdbmi
4756 *** Changes in GDB-4.18:
4758 * New native configurations
4760 HP-UX 10.20 hppa*-*-hpux10.20
4761 HP-UX 11.x hppa*-*-hpux11.0*
4762 M68K GNU/Linux m68*-*-linux*
4766 Fujitsu FR30 fr30-*-elf*
4767 Intel StrongARM strongarm-*-*
4768 Mitsubishi D30V d30v-*-*
4770 * OBSOLETE configurations
4772 Gould PowerNode, NP1 np1-*-*, pn-*-*
4774 Configurations that have been declared obsolete will be commented out,
4775 but the code will be left in place. If there is no activity to revive
4776 these configurations before the next release of GDB, the sources will
4777 be permanently REMOVED.
4781 As a compatibility experiment, GDB's source files buildsym.h and
4782 buildsym.c have been converted to pure standard C, no longer
4783 containing any K&R compatibility code. We believe that all systems in
4784 use today either come with a standard C compiler, or have a GCC port
4785 available. If this is not true, please report the affected
4786 configuration to bug-gdb@gnu.org immediately. See the README file for
4787 information about getting a standard C compiler if you don't have one
4792 GDB now uses readline 2.2.
4794 * set extension-language
4796 You can now control the mapping between filename extensions and source
4797 languages by using the `set extension-language' command. For instance,
4798 you can ask GDB to treat .c files as C++ by saying
4799 set extension-language .c c++
4800 The command `info extensions' lists all of the recognized extensions
4801 and their associated languages.
4803 * Setting processor type for PowerPC and RS/6000
4805 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4806 you can use the `set processor' command to specify what variant of the
4807 PowerPC family you are debugging. The command
4811 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4812 following PowerPC and RS6000 variants:
4814 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4815 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4817 403GC IBM PowerPC 403GC
4818 505 Motorola PowerPC 505
4819 860 Motorola PowerPC 860 or 850
4820 601 Motorola PowerPC 601
4821 602 Motorola PowerPC 602
4822 603 Motorola/IBM PowerPC 603 or 603e
4823 604 Motorola PowerPC 604 or 604e
4824 750 Motorola/IBM PowerPC 750 or 750
4826 At the moment, this command just tells GDB what to name the
4827 special-purpose processor registers. Since almost all the affected
4828 registers are inaccessible to user-level programs, this command is
4829 only useful for remote debugging in its present form.
4833 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4834 more extensive support for HP-UX. Added features include shared
4835 library support, kernel threads and hardware watchpoints for 11.00,
4836 support for HP's ANSI C and C++ compilers, and a compatibility mode
4837 for xdb and dbx commands.
4841 HP's donation includes the new concept of catchpoints, which is a
4842 generalization of the old catch command. On HP-UX, it is now possible
4843 to catch exec, fork, and vfork, as well as library loading.
4845 This means that the existing catch command has changed; its first
4846 argument now specifies the type of catch to be set up. See the
4847 output of "help catch" for a list of catchpoint types.
4849 * Debugging across forks
4851 On HP-UX, you can choose which process to debug when a fork() happens
4856 HP has donated a curses-based terminal user interface (TUI). To get
4857 it, build with --enable-tui. Although this can be enabled for any
4858 configuration, at present it only works for native HP debugging.
4860 * GDB remote protocol additions
4862 A new protocol packet 'X' that writes binary data is now available.
4863 Default behavior is to try 'X', then drop back to 'M' if the stub
4864 fails to respond. The settable variable `remotebinarydownload'
4865 allows explicit control over the use of 'X'.
4867 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4868 full 64-bit address. The command
4870 set remoteaddresssize 32
4872 can be used to revert to the old behaviour. For existing remote stubs
4873 the change should not be noticed, as the additional address information
4876 In order to assist in debugging stubs, you may use the maintenance
4877 command `packet' to send any text string to the stub. For instance,
4879 maint packet heythere
4881 sends the packet "$heythere#<checksum>". Note that it is very easy to
4882 disrupt a debugging session by sending the wrong packet at the wrong
4885 The compare-sections command allows you to compare section data on the
4886 target to what is in the executable file without uploading or
4887 downloading, by comparing CRC checksums.
4889 * Tracing can collect general expressions
4891 You may now collect general expressions at tracepoints. This requires
4892 further additions to the target-side stub; see tracepoint.c and
4893 doc/agentexpr.texi for further details.
4895 * mask-address variable for Mips
4897 For Mips targets, you may control the zeroing of the upper 32 bits of
4898 a 64-bit address by entering `set mask-address on'. This is mainly
4899 of interest to users of embedded R4xxx and R5xxx processors.
4901 * Higher serial baud rates
4903 GDB's serial code now allows you to specify baud rates 57600, 115200,
4904 230400, and 460800 baud. (Note that your host system may not be able
4905 to achieve all of these rates.)
4909 The i960 configuration now includes an initial implementation of a
4910 builtin simulator, contributed by Jim Wilson.
4913 *** Changes in GDB-4.17:
4915 * New native configurations
4917 Alpha GNU/Linux alpha*-*-linux*
4918 Unixware 2.x i[3456]86-unixware2*
4919 Irix 6.x mips*-sgi-irix6*
4920 PowerPC GNU/Linux powerpc-*-linux*
4921 PowerPC Solaris powerpcle-*-solaris*
4922 Sparc GNU/Linux sparc-*-linux*
4923 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4927 Argonaut Risc Chip (ARC) arc-*-*
4928 Hitachi H8/300S h8300*-*-*
4929 Matsushita MN10200 w/simulator mn10200-*-*
4930 Matsushita MN10300 w/simulator mn10300-*-*
4931 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4932 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4933 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4934 Mitsubishi D10V w/simulator d10v-*-*
4935 Mitsubishi M32R/D w/simulator m32r-*-elf*
4936 Tsqware Sparclet sparclet-*-*
4937 NEC V850 w/simulator v850-*-*
4939 * New debugging protocols
4941 ARM with RDI protocol arm*-*-*
4942 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4943 DDB and LSI variants of PMON protocol mips*-*-*
4944 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4945 PowerPC with SDS protocol powerpc{,le}-*-eabi
4946 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4950 All configurations can now understand and use the DWARF 2 debugging
4951 format. The choice is automatic, if the symbol file contains DWARF 2
4956 GDB now includes basic Java language support. This support is
4957 only useful with Java compilers that produce native machine code.
4959 * solib-absolute-prefix and solib-search-path
4961 For SunOS and SVR4 shared libraries, you may now set the prefix for
4962 loading absolute shared library symbol files, and the search path for
4963 locating non-absolute shared library symbol files.
4965 * Live range splitting
4967 GDB can now effectively debug code for which GCC has performed live
4968 range splitting as part of its optimization. See gdb/doc/LRS for
4969 more details on the expected format of the stabs information.
4973 GDB's support for the GNU Hurd, including thread debugging, has been
4974 updated to work with current versions of the Hurd.
4978 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4979 instruction set. ARM GDB automatically detects when Thumb
4980 instructions are in use, and adjusts disassembly and backtracing
4985 GDB's MIPS target configurations now handle the MIP16 16-bit
4990 GDB now includes support for overlays; if an executable has been
4991 linked such that multiple sections are based at the same address, GDB
4992 will decide which section to use for symbolic info. You can choose to
4993 control the decision manually, using overlay commands, or implement
4994 additional target-side support and use "overlay load-target" to bring
4995 in the overlay mapping. Do "help overlay" for more detail.
4999 The command "info symbol <address>" displays information about
5000 the symbol at the specified address.
5004 The standard remote protocol now includes an extension that allows
5005 asynchronous collection and display of trace data. This requires
5006 extensive support in the target-side debugging stub. Tracing mode
5007 includes a new interaction mode in GDB and new commands: see the
5008 file tracepoint.c for more details.
5012 Configurations for embedded MIPS now include a simulator contributed
5013 by Cygnus Solutions. The simulator supports the instruction sets
5014 of most MIPS variants.
5018 Sparc configurations may now include the ERC32 simulator contributed
5019 by the European Space Agency. The simulator is not built into
5020 Sparc targets by default; configure with --enable-sim to include it.
5024 For target configurations that may include multiple variants of a
5025 basic architecture (such as MIPS and SH), you may now set the
5026 architecture explicitly. "set arch" sets, "info arch" lists
5027 the possible architectures.
5029 *** Changes in GDB-4.16:
5031 * New native configurations
5033 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5034 M68K NetBSD m68k-*-netbsd*
5035 PowerPC AIX 4.x powerpc-*-aix*
5036 PowerPC MacOS powerpc-*-macos*
5037 PowerPC Windows NT powerpcle-*-cygwin32
5038 RS/6000 AIX 4.x rs6000-*-aix4*
5042 ARM with RDP protocol arm-*-*
5043 I960 with MON960 i960-*-coff
5044 MIPS VxWorks mips*-*-vxworks*
5045 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5046 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5048 Matra Sparclet sparclet-*-*
5052 The powerpc-eabi configuration now includes the PSIM simulator,
5053 contributed by Andrew Cagney, with assistance from Mike Meissner.
5054 PSIM is a very elaborate model of the PowerPC, including not only
5055 basic instruction set execution, but also details of execution unit
5056 performance and I/O hardware. See sim/ppc/README for more details.
5060 GDB now works with Solaris 2.5.
5062 * Windows 95/NT native
5064 GDB will now work as a native debugger on Windows 95 and Windows NT.
5065 To build it from source, you must use the "gnu-win32" environment,
5066 which uses a DLL to emulate enough of Unix to run the GNU tools.
5067 Further information, binaries, and sources are available at
5068 ftp.cygnus.com, under pub/gnu-win32.
5070 * dont-repeat command
5072 If a user-defined command includes the command `dont-repeat', then the
5073 command will not be repeated if the user just types return. This is
5074 useful if the command is time-consuming to run, so that accidental
5075 extra keystrokes don't run the same command many times.
5077 * Send break instead of ^C
5079 The standard remote protocol now includes an option to send a break
5080 rather than a ^C to the target in order to interrupt it. By default,
5081 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5083 * Remote protocol timeout
5085 The standard remote protocol includes a new variable `remotetimeout'
5086 that allows you to set the number of seconds before GDB gives up trying
5087 to read from the target. The default value is 2.
5089 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5091 By default GDB will automatically keep track of objects as they are
5092 loaded and unloaded by the dynamic linker. By using the command `set
5093 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5094 when shared library events occur, thus allowing you to set breakpoints
5095 in shared libraries which are explicitly loaded by the inferior.
5097 Note this feature does not work on hpux8. On hpux9 you must link
5098 /usr/lib/end.o into your program. This feature should work
5099 automatically on hpux10.
5101 * Irix 5.x hardware watchpoint support
5103 Irix 5 configurations now support the use of hardware watchpoints.
5105 * Mips protocol "SYN garbage limit"
5107 When debugging a Mips target using the `target mips' protocol, you
5108 may set the number of characters that GDB will ignore by setting
5109 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5110 every character. The default value is 1050.
5112 * Recording and replaying remote debug sessions
5114 If you set `remotelogfile' to the name of a file, gdb will write to it
5115 a recording of a remote debug session. This recording may then be
5116 replayed back to gdb using "gdbreplay". See gdbserver/README for
5117 details. This is useful when you have a problem with GDB while doing
5118 remote debugging; you can make a recording of the session and send it
5119 to someone else, who can then recreate the problem.
5121 * Speedups for remote debugging
5123 GDB includes speedups for downloading and stepping MIPS systems using
5124 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5125 and more efficient S-record downloading.
5127 * Memory use reductions and statistics collection
5129 GDB now uses less memory and reports statistics about memory usage.
5130 Try the `maint print statistics' command, for example.
5132 *** Changes in GDB-4.15:
5134 * Psymtabs for XCOFF
5136 The symbol reader for AIX GDB now uses partial symbol tables. This
5137 can greatly improve startup time, especially for large executables.
5139 * Remote targets use caching
5141 Remote targets now use a data cache to speed up communication with the
5142 remote side. The data cache could lead to incorrect results because
5143 it doesn't know about volatile variables, thus making it impossible to
5144 debug targets which use memory mapped I/O devices. `set remotecache
5145 off' turns the the data cache off.
5147 * Remote targets may have threads
5149 The standard remote protocol now includes support for multiple threads
5150 in the target system, using new protocol commands 'H' and 'T'. See
5151 gdb/remote.c for details.
5155 If GDB is configured with `--enable-netrom', then it will include
5156 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5157 acts as though it is a bank of ROM on the target board, but you can
5158 write into it over the network. GDB's support consists only of
5159 support for fast loading into the emulated ROM; to debug, you must use
5160 another protocol, such as standard remote protocol. The usual
5161 sequence is something like
5163 target nrom <netrom-hostname>
5165 target remote <netrom-hostname>:1235
5169 GDB now includes support for the Apple Macintosh, as a host only. It
5170 may be run as either an MPW tool or as a standalone application, and
5171 it can debug through the serial port. All the usual GDB commands are
5172 available, but to the target command, you must supply "serial" as the
5173 device type instead of "/dev/ttyXX". See mpw-README in the main
5174 directory for more information on how to build. The MPW configuration
5175 scripts */mpw-config.in support only a few targets, and only the
5176 mips-idt-ecoff target has been tested.
5180 GDB configuration now uses autoconf. This is not user-visible,
5181 but does simplify configuration and building.
5185 GDB now supports hpux10.
5187 *** Changes in GDB-4.14:
5189 * New native configurations
5191 x86 FreeBSD i[345]86-*-freebsd
5192 x86 NetBSD i[345]86-*-netbsd
5193 NS32k NetBSD ns32k-*-netbsd
5194 Sparc NetBSD sparc-*-netbsd
5198 A29K VxWorks a29k-*-vxworks
5199 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5200 CPU32 EST-300 emulator m68*-*-est*
5201 PowerPC ELF powerpc-*-elf
5204 * Alpha OSF/1 support for procfs
5206 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5207 possible to attach to running processes. As the mounting of the /proc
5208 filesystem is optional on the Alpha, GDB automatically determines
5209 the availability of /proc during startup. This can lead to problems
5210 if /proc is unmounted after GDB has been started.
5212 * Arguments to user-defined commands
5214 User commands may accept up to 10 arguments separated by whitespace.
5215 Arguments are accessed within the user command via $arg0..$arg9. A
5218 print $arg0 + $arg1 + $arg2
5220 To execute the command use:
5223 Defines the command "adder" which prints the sum of its three arguments.
5224 Note the arguments are text substitutions, so they may reference variables,
5225 use complex expressions, or even perform inferior function calls.
5227 * New `if' and `while' commands
5229 This makes it possible to write more sophisticated user-defined
5230 commands. Both commands take a single argument, which is the
5231 expression to evaluate, and must be followed by the commands to
5232 execute, one per line, if the expression is nonzero, the list being
5233 terminated by the word `end'. The `if' command list may include an
5234 `else' word, which causes the following commands to be executed only
5235 if the expression is zero.
5237 * Fortran source language mode
5239 GDB now includes partial support for Fortran 77. It will recognize
5240 Fortran programs and can evaluate a subset of Fortran expressions, but
5241 variables and functions may not be handled correctly. GDB will work
5242 with G77, but does not yet know much about symbols emitted by other
5245 * Better HPUX support
5247 Most debugging facilities now work on dynamic executables for HPPAs
5248 running hpux9 or later. You can attach to running dynamically linked
5249 processes, but by default the dynamic libraries will be read-only, so
5250 for instance you won't be able to put breakpoints in them. To change
5251 that behavior do the following before running the program:
5257 This will cause the libraries to be mapped private and read-write.
5258 To revert to the normal behavior, do this:
5264 You cannot set breakpoints or examine data in the library until after
5265 the library is loaded if the function/data symbols do not have
5268 GDB can now also read debug symbols produced by the HP C compiler on
5269 HPPAs (sorry, no C++, Fortran or 68k support).
5271 * Target byte order now dynamically selectable
5273 You can choose which byte order to use with a target system, via the
5274 commands "set endian big" and "set endian little", and you can see the
5275 current setting by using "show endian". You can also give the command
5276 "set endian auto", in which case GDB will use the byte order
5277 associated with the executable. Currently, only embedded MIPS
5278 configurations support dynamic selection of target byte order.
5280 * New DOS host serial code
5282 This version uses DPMI interrupts to handle buffered I/O, so you
5283 no longer need to run asynctsr when debugging boards connected to
5286 *** Changes in GDB-4.13:
5288 * New "complete" command
5290 This lists all the possible completions for the rest of the line, if it
5291 were to be given as a command itself. This is intended for use by emacs.
5293 * Trailing space optional in prompt
5295 "set prompt" no longer adds a space for you after the prompt you set. This
5296 allows you to set a prompt which ends in a space or one that does not.
5298 * Breakpoint hit counts
5300 "info break" now displays a count of the number of times the breakpoint
5301 has been hit. This is especially useful in conjunction with "ignore"; you
5302 can ignore a large number of breakpoint hits, look at the breakpoint info
5303 to see how many times the breakpoint was hit, then run again, ignoring one
5304 less than that number, and this will get you quickly to the last hit of
5307 * Ability to stop printing at NULL character
5309 "set print null-stop" will cause GDB to stop printing the characters of
5310 an array when the first NULL is encountered. This is useful when large
5311 arrays actually contain only short strings.
5313 * Shared library breakpoints
5315 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5316 breakpoints in shared libraries before the executable is run.
5318 * Hardware watchpoints
5320 There is a new hardware breakpoint for the watch command for sparclite
5321 targets. See gdb/sparclite/hw_breakpoint.note.
5323 Hardware watchpoints are also now supported under GNU/Linux.
5327 Annotations have been added. These are for use with graphical interfaces,
5328 and are still experimental. Currently only gdba.el uses these.
5330 * Improved Irix 5 support
5332 GDB now works properly with Irix 5.2.
5334 * Improved HPPA support
5336 GDB now works properly with the latest GCC and GAS.
5338 * New native configurations
5340 Sequent PTX4 i[34]86-sequent-ptx4
5341 HPPA running OSF/1 hppa*-*-osf*
5342 Atari TT running SVR4 m68*-*-sysv4*
5343 RS/6000 LynxOS rs6000-*-lynxos*
5347 OS/9000 i[34]86-*-os9k
5348 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5351 * Hitachi SH7000 and E7000-PC ICE support
5353 There is now support for communicating with the Hitachi E7000-PC ICE.
5354 This is available automatically when GDB is configured for the SH.
5358 As usual, a variety of small fixes and improvements, both generic
5359 and configuration-specific. See the ChangeLog for more detail.
5361 *** Changes in GDB-4.12:
5363 * Irix 5 is now supported
5367 GDB-4.12 on the HPPA has a number of changes which make it unable
5368 to debug the output from the currently released versions of GCC and
5369 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5370 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5371 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5374 *** Changes in GDB-4.11:
5376 * User visible changes:
5380 The "set remotedebug" option is now consistent between the mips remote
5381 target, remote targets using the gdb-specific protocol, UDI (AMD's
5382 debug protocol for the 29k) and the 88k bug monitor. It is now an
5383 integer specifying a debug level (normally 0 or 1, but 2 means more
5384 debugging info for the mips target).
5386 * DEC Alpha native support
5388 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5389 debug info, but GDB works fairly well with the DEC compiler and should
5390 work with a future GCC release. See the README file for a few
5391 Alpha-specific notes.
5393 * Preliminary thread implementation
5395 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5397 * LynxOS native and target support for 386
5399 This release has been hosted on LynxOS 2.2, and also can be configured
5400 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5403 * Improvements in C++ mangling/demangling.
5405 This release has much better g++ debugging, specifically in name
5406 mangling/demangling, virtual function calls, print virtual table,
5407 call methods, ...etc.
5409 *** Changes in GDB-4.10:
5411 * User visible changes:
5413 Remote debugging using the GDB-specific (`target remote') protocol now
5414 supports the `load' command. This is only useful if you have some
5415 other way of getting the stub to the target system, and you can put it
5416 somewhere in memory where it won't get clobbered by the download.
5418 Filename completion now works.
5420 When run under emacs mode, the "info line" command now causes the
5421 arrow to point to the line specified. Also, "info line" prints
5422 addresses in symbolic form (as well as hex).
5424 All vxworks based targets now support a user settable option, called
5425 vxworks-timeout. This option represents the number of seconds gdb
5426 should wait for responses to rpc's. You might want to use this if
5427 your vxworks target is, perhaps, a slow software simulator or happens
5428 to be on the far side of a thin network line.
5432 This release contains support for using a DEC alpha as a GDB host for
5433 cross debugging. Native alpha debugging is not supported yet.
5436 *** Changes in GDB-4.9:
5440 This is the first GDB release which is accompanied by a matching testsuite.
5441 The testsuite requires installation of dejagnu, which should be available
5442 via ftp from most sites that carry GNU software.
5446 'Cfront' style demangling has had its name changed to 'ARM' style, to
5447 emphasize that it was written from the specifications in the C++ Annotated
5448 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5449 disclaimers, it still generated too much confusion with users attempting to
5450 use gdb with AT&T cfront.
5454 GDB now uses a standard remote interface to a simulator library.
5455 So far, the library contains simulators for the Zilog Z8001/2, the
5456 Hitachi H8/300, H8/500 and Super-H.
5458 * New targets supported
5460 H8/300 simulator h8300-hitachi-hms or h8300hms
5461 H8/500 simulator h8500-hitachi-hms or h8500hms
5462 SH simulator sh-hitachi-hms or sh
5463 Z8000 simulator z8k-zilog-none or z8ksim
5464 IDT MIPS board over serial line mips-idt-ecoff
5466 Cross-debugging to GO32 targets is supported. It requires a custom
5467 version of the i386-stub.c module which is integrated with the
5468 GO32 memory extender.
5470 * New remote protocols
5472 MIPS remote debugging protocol.
5474 * New source languages supported
5476 This version includes preliminary support for Chill, a Pascal like language
5477 used by telecommunications companies. Chill support is also being integrated
5478 into the GNU compiler, but we don't know when it will be publically available.
5481 *** Changes in GDB-4.8:
5483 * HP Precision Architecture supported
5485 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5486 version of this support was available as a set of patches from the
5487 University of Utah. GDB does not support debugging of programs
5488 compiled with the HP compiler, because HP will not document their file
5489 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5490 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5492 Many problems in the preliminary version have been fixed.
5494 * Faster and better demangling
5496 We have improved template demangling and fixed numerous bugs in the GNU style
5497 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5498 character types (wchar_t) are now supported. Demangling of each symbol is now
5499 only done once, and is cached when the symbol table for a file is read in.
5500 This results in a small increase in memory usage for C programs, a moderate
5501 increase in memory usage for C++ programs, and a fantastic speedup in
5504 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5505 from the specifications in the Annotated Reference Manual, which AT&T's
5506 compiler does not actually implement.
5508 * G++ multiple inheritance compiler problem
5510 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5511 inheritance lattices was reworked to properly discover ambiguities. We
5512 recently found an example which causes this new algorithm to fail in a
5513 very subtle way, producing bad debug information for those classes.
5514 The file 'gcc.patch' (in this directory) can be applied to gcc to
5515 circumvent the problem. A future GCC release will contain a complete
5518 The previous G++ debug info problem (mentioned below for the gdb-4.7
5519 release) is fixed in gcc version 2.3.2.
5521 * Improved configure script
5523 The `configure' script will now attempt to guess your system type if
5524 you don't supply a host system type. The old scheme of supplying a
5525 host system triplet is preferable over using this. All the magic is
5526 done in the new `config.guess' script. Examine it for details.
5528 We have also brought our configure script much more in line with the FSF's
5529 version. It now supports the --with-xxx options. In particular,
5530 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5531 The resulting GDB will not be able to read arbitrary object file formats --
5532 only the format ``expected'' to be used on the configured target system.
5533 We hope to make this the default in a future release.
5535 * Documentation improvements
5537 There's new internal documentation on how to modify GDB, and how to
5538 produce clean changes to the code. We implore people to read it
5539 before submitting changes.
5541 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5542 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5543 `info' files are also provided. To build `info' files from scratch,
5544 you will need the latest `makeinfo' release, which will be available in
5545 a future texinfo-X.Y release.
5547 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5548 We're not sure exactly which versions have this problem, but it has
5549 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5550 or better. If that isn't possible, there is a patch in
5551 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5552 around this problem.
5556 GDB now supports array constants that can be used in expressions typed in by
5557 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5558 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5561 The new directory `gdb/sparclite' contains a program that demonstrates
5562 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5564 * New native hosts supported
5566 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5567 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5569 * New targets supported
5571 AMD 29k family via UDI a29k-amd-udi or udi29k
5573 * New file formats supported
5575 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5576 HPUX core files, and SCO 3.2v2 core files.
5580 Attaching to processes now works again; thanks for the many bug reports.
5582 We have also stomped on a bunch of core dumps caused by
5583 printf_filtered("%s") problems.
5585 We eliminated a copyright problem on the rpc and ptrace header files
5586 for VxWorks, which was discovered at the last minute during the 4.7
5587 release. You should now be able to build a VxWorks GDB.
5589 You can now interrupt gdb while an attached process is running. This
5590 will cause the attached process to stop, and give control back to GDB.
5592 We fixed problems caused by using too many file descriptors
5593 for reading symbols from object files and libraries. This was
5594 especially a problem for programs that used many (~100) shared
5597 The `step' command now only enters a subroutine if there is line number
5598 information for the subroutine. Otherwise it acts like the `next'
5599 command. Previously, `step' would enter subroutines if there was
5600 any debugging information about the routine. This avoids problems
5601 when using `cc -g1' on MIPS machines.
5603 * Internal improvements
5605 GDB's internal interfaces have been improved to make it easier to support
5606 debugging of multiple languages in the future.
5608 GDB now uses a common structure for symbol information internally.
5609 Minimal symbols (derived from linkage symbols in object files), partial
5610 symbols (from a quick scan of debug information), and full symbols
5611 contain a common subset of information, making it easier to write
5612 shared code that handles any of them.
5614 * New command line options
5616 We now accept --silent as an alias for --quiet.
5620 The memory-mapped-malloc library is now licensed under the GNU Library
5621 General Public License.
5623 *** Changes in GDB-4.7:
5625 * Host/native/target split
5627 GDB has had some major internal surgery to untangle the support for
5628 hosts and remote targets. Now, when you configure GDB for a remote
5629 target, it will no longer load in all of the support for debugging
5630 local programs on the host. When fully completed and tested, this will
5631 ensure that arbitrary host/target combinations are possible.
5633 The primary conceptual shift is to separate the non-portable code in
5634 GDB into three categories. Host specific code is required any time GDB
5635 is compiled on that host, regardless of the target. Target specific
5636 code relates to the peculiarities of the target, but can be compiled on
5637 any host. Native specific code is everything else: it can only be
5638 built when the host and target are the same system. Child process
5639 handling and core file support are two common `native' examples.
5641 GDB's use of /proc for controlling Unix child processes is now cleaner.
5642 It has been split out into a single module under the `target_ops' vector,
5643 plus two native-dependent functions for each system that uses /proc.
5645 * New hosts supported
5647 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5648 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5649 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5651 * New targets supported
5653 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5654 68030 and CPU32 m68030-*-*, m68332-*-*
5656 * New native hosts supported
5658 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5659 (386bsd is not well tested yet)
5660 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5662 * New file formats supported
5664 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5665 supports reading of `a.out.adobe' object files, which are an a.out
5666 format extended with minimal information about multiple sections.
5670 `show copying' is the same as the old `info copying'.
5671 `show warranty' is the same as `info warrantee'.
5672 These were renamed for consistency. The old commands continue to work.
5674 `info handle' is a new alias for `info signals'.
5676 You can now define pre-command hooks, which attach arbitrary command
5677 scripts to any command. The commands in the hook will be executed
5678 prior to the user's command. You can also create a hook which will be
5679 executed whenever the program stops. See gdb.texinfo.
5683 We now deal with Cfront style name mangling, and can even extract type
5684 info from mangled symbols. GDB can automatically figure out which
5685 symbol mangling style your C++ compiler uses.
5687 Calling of methods and virtual functions has been improved as well.
5691 The crash that occured when debugging Sun Ansi-C compiled binaries is
5692 fixed. This was due to mishandling of the extra N_SO stabs output
5695 We also finally got Ultrix 4.2 running in house, and fixed core file
5696 support, with help from a dozen people on the net.
5698 John M. Farrell discovered that the reason that single-stepping was so
5699 slow on all of the Mips based platforms (primarily SGI and DEC) was
5700 that we were trying to demangle and lookup a symbol used for internal
5701 purposes on every instruction that was being stepped through. Changing
5702 the name of that symbol so that it couldn't be mistaken for a C++
5703 mangled symbol sped things up a great deal.
5705 Rich Pixley sped up symbol lookups in general by getting much smarter
5706 about when C++ symbol mangling is necessary. This should make symbol
5707 completion (TAB on the command line) much faster. It's not as fast as
5708 we'd like, but it's significantly faster than gdb-4.6.
5712 A new user controllable variable 'call_scratch_address' can
5713 specify the location of a scratch area to be used when GDB
5714 calls a function in the target. This is necessary because the
5715 usual method of putting the scratch area on the stack does not work
5716 in systems that have separate instruction and data spaces.
5718 We integrated changes to support the 29k UDI (Universal Debugger
5719 Interface), but discovered at the last minute that we didn't have all
5720 of the appropriate copyright paperwork. We are working with AMD to
5721 resolve this, and hope to have it available soon.
5725 We have sped up the remote serial line protocol, especially for targets
5726 with lots of registers. It now supports a new `expedited status' ('T')
5727 message which can be used in place of the existing 'S' status message.
5728 This allows the remote stub to send only the registers that GDB
5729 needs to make a quick decision about single-stepping or conditional
5730 breakpoints, eliminating the need to fetch the entire register set for
5731 each instruction being stepped through.
5733 The GDB remote serial protocol now implements a write-through cache for
5734 registers, only re-reading the registers if the target has run.
5736 There is also a new remote serial stub for SPARC processors. You can
5737 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5738 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5739 processor with a serial port.
5743 Configure.in files have become much easier to read and modify. A new
5744 `table driven' format makes it more obvious what configurations are
5745 supported, and what files each one uses.
5749 There is a new opcodes library which will eventually contain all of the
5750 disassembly routines and opcode tables. At present, it only contains
5751 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5752 disassembler (binutils/objdump) to share these routines.
5754 The libiberty library is now copylefted under the GNU Library General
5755 Public License. This allows more liberal use, and was done so libg++
5756 can use it. This makes no difference to GDB, since the Library License
5757 grants all the rights from the General Public License.
5761 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5762 reference to the stabs symbol info used by the debugger. It is (as far
5763 as we know) the only published document on this fascinating topic. We
5764 encourage you to read it, compare it to the stabs information on your
5765 system, and send improvements on the document in general (to
5766 bug-gdb@prep.ai.mit.edu).
5768 And, of course, many bugs have been fixed.
5771 *** Changes in GDB-4.6:
5773 * Better support for C++ function names
5775 GDB now accepts as input the "demangled form" of C++ overloaded function
5776 names and member function names, and can do command completion on such names
5777 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5778 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5779 Make use of command completion, it is your friend.
5781 GDB also now accepts a variety of C++ mangled symbol formats. They are
5782 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5783 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5784 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5785 for the list of formats.
5787 * G++ symbol mangling problem
5789 Recent versions of gcc have a bug in how they emit debugging information for
5790 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5791 directory) can be applied to gcc to fix the problem. Alternatively, if you
5792 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5793 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5794 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5797 * New 'maintenance' command
5799 All of the commands related to hacking GDB internals have been moved out of
5800 the main command set, and now live behind the 'maintenance' command. This
5801 can also be abbreviated as 'mt'. The following changes were made:
5803 dump-me -> maintenance dump-me
5804 info all-breakpoints -> maintenance info breakpoints
5805 printmsyms -> maintenance print msyms
5806 printobjfiles -> maintenance print objfiles
5807 printpsyms -> maintenance print psymbols
5808 printsyms -> maintenance print symbols
5810 The following commands are new:
5812 maintenance demangle Call internal GDB demangler routine to
5813 demangle a C++ link name and prints the result.
5814 maintenance print type Print a type chain for a given symbol
5816 * Change to .gdbinit file processing
5818 We now read the $HOME/.gdbinit file before processing the argv arguments
5819 (e.g. reading symbol files or core files). This allows global parameters to
5820 be set, which will apply during the symbol reading. The ./.gdbinit is still
5821 read after argv processing.
5823 * New hosts supported
5825 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5827 GNU/Linux support i386-unknown-linux or linux
5829 We are also including code to support the HP/PA running BSD and HPUX. This
5830 is almost guaranteed not to work, as we didn't have time to test or build it
5831 for this release. We are including it so that the more adventurous (or
5832 masochistic) of you can play with it. We also had major problems with the
5833 fact that the compiler that we got from HP doesn't support the -g option.
5836 * New targets supported
5838 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5840 * More smarts about finding #include files
5842 GDB now remembers the compilation directory for all include files, and for
5843 all files from which C is generated (like yacc and lex sources). This
5844 greatly improves GDB's ability to find yacc/lex sources, and include files,
5845 especially if you are debugging your program from a directory different from
5846 the one that contains your sources.
5848 We also fixed a bug which caused difficulty with listing and setting
5849 breakpoints in include files which contain C code. (In the past, you had to
5850 try twice in order to list an include file that you hadn't looked at before.)
5852 * Interesting infernals change
5854 GDB now deals with arbitrary numbers of sections, where the symbols for each
5855 section must be relocated relative to that section's landing place in the
5856 target's address space. This work was needed to support ELF with embedded
5857 stabs used by Solaris-2.0.
5859 * Bug fixes (of course!)
5861 There have been loads of fixes for the following things:
5862 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5863 i960, stabs, DOS(GO32), procfs, etc...
5865 See the ChangeLog for details.
5867 *** Changes in GDB-4.5:
5869 * New machines supported (host and target)
5871 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5873 SGI Irix-4.x mips-sgi-irix4 or iris4
5875 * New malloc package
5877 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5878 Mmalloc is capable of handling mutiple heaps of memory. It is also
5879 capable of saving a heap to a file, and then mapping it back in later.
5880 This can be used to greatly speedup the startup of GDB by using a
5881 pre-parsed symbol table which lives in a mmalloc managed heap. For
5882 more details, please read mmalloc/mmalloc.texi.
5886 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5887 'help info proc' for details.
5889 * MIPS ecoff symbol table format
5891 The code that reads MIPS symbol table format is now supported on all hosts.
5892 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5895 * File name changes for MS-DOS
5897 Many files in the config directories have been renamed to make it easier to
5898 support GDB on MS-DOSe systems (which have very restrictive file name
5899 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5900 environment) is close to working but has some remaining problems. Note
5901 that debugging of DOS programs is not supported, due to limitations
5902 in the ``operating system'', but it can be used to host cross-debugging.
5904 * Cross byte order fixes
5906 Many fixes have been made to support cross debugging of Sparc and MIPS
5907 targets from hosts whose byte order differs.
5909 * New -mapped and -readnow options
5911 If memory-mapped files are available on your system through the 'mmap'
5912 system call, you can use the -mapped option on the `file' or
5913 `symbol-file' commands to cause GDB to write the symbols from your
5914 program into a reusable file. If the program you are debugging is
5915 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5916 Future GDB debugging sessions will notice the presence of this file,
5917 and will quickly map in symbol information from it, rather than reading
5918 the symbol table from the executable program. Using the '-mapped'
5919 option in a GDB `file' or `symbol-file' command has the same effect as
5920 starting GDB with the '-mapped' command-line option.
5922 You can cause GDB to read the entire symbol table immediately by using
5923 the '-readnow' option with any of the commands that load symbol table
5924 information (or on the GDB command line). This makes the command
5925 slower, but makes future operations faster.
5927 The -mapped and -readnow options are typically combined in order to
5928 build a `fred.syms' file that contains complete symbol information.
5929 A simple GDB invocation to do nothing but build a `.syms' file for future
5932 gdb -batch -nx -mapped -readnow programname
5934 The `.syms' file is specific to the host machine on which GDB is run.
5935 It holds an exact image of GDB's internal symbol table. It cannot be
5936 shared across multiple host platforms.
5938 * longjmp() handling
5940 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5941 siglongjmp() without losing control. This feature has not yet been ported to
5942 all systems. It currently works on many 386 platforms, all MIPS-based
5943 platforms (SGI, DECstation, etc), and Sun3/4.
5947 Preliminary work has been put in to support the new Solaris OS from Sun. At
5948 this time, it can control and debug processes, but it is not capable of
5953 As always, many many bug fixes. The major areas were with g++, and mipsread.
5954 People using the MIPS-based platforms should experience fewer mysterious
5955 crashes and trashed symbol tables.
5957 *** Changes in GDB-4.4:
5959 * New machines supported (host and target)
5961 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5963 BSD Reno on Vax vax-dec-bsd
5964 Ultrix on Vax vax-dec-ultrix
5966 * New machines supported (target)
5968 AMD 29000 embedded, using EBMON a29k-none-none
5972 GDB continues to improve its handling of C++. `References' work better.
5973 The demangler has also been improved, and now deals with symbols mangled as
5974 per the Annotated C++ Reference Guide.
5976 GDB also now handles `stabs' symbol information embedded in MIPS
5977 `ecoff' symbol tables. Since the ecoff format was not easily
5978 extensible to handle new languages such as C++, this appeared to be a
5979 good way to put C++ debugging info into MIPS binaries. This option
5980 will be supported in the GNU C compiler, version 2, when it is
5983 * New features for SVR4
5985 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5986 shared libraries. Debugging dynamically linked programs should present
5987 only minor differences from debugging statically linked programs.
5989 The `info proc' command will print out information about any process
5990 on an SVR4 system (including the one you are debugging). At the moment,
5991 it prints the address mappings of the process.
5993 If you bring up GDB on another SVR4 system, please send mail to
5994 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5996 * Better dynamic linking support in SunOS
5998 Reading symbols from shared libraries which contain debugging symbols
5999 now works properly. However, there remain issues such as automatic
6000 skipping of `transfer vector' code during function calls, which
6001 make it harder to debug code in a shared library, than to debug the
6002 same code linked statically.
6006 GDB is now using the latest `getopt' routines from the FSF. This
6007 version accepts the -- prefix for options with long names. GDB will
6008 continue to accept the old forms (-option and +option) as well.
6009 Various single letter abbreviations for options have been explicity
6010 added to the option table so that they won't get overshadowed in the
6011 future by other options that begin with the same letter.
6015 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6016 Many assorted bugs have been handled. Many more remain to be handled.
6017 See the various ChangeLog files (primarily in gdb and bfd) for details.
6020 *** Changes in GDB-4.3:
6022 * New machines supported (host and target)
6024 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6025 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6026 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6028 * Almost SCO Unix support
6030 We had hoped to support:
6031 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6032 (except for core file support), but we discovered very late in the release
6033 that it has problems with process groups that render gdb unusable. Sorry
6034 about that. I encourage people to fix it and post the fixes.
6036 * Preliminary ELF and DWARF support
6038 GDB can read ELF object files on System V Release 4, and can handle
6039 debugging records for C, in DWARF format, in ELF files. This support
6040 is preliminary. If you bring up GDB on another SVR4 system, please
6041 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6046 GDB now uses the latest `readline' library. One user-visible change
6047 is that two tabs will list possible command completions, which previously
6048 required typing M-? (meta-question mark, or ESC ?).
6052 The `stepi' bug that many of you noticed has been squashed.
6053 Many bugs in C++ have been handled. Many more remain to be handled.
6054 See the various ChangeLog files (primarily in gdb and bfd) for details.
6056 * State of the MIPS world (in case you wondered):
6058 GDB can understand the symbol tables emitted by the compilers
6059 supplied by most vendors of MIPS-based machines, including DEC. These
6060 symbol tables are in a format that essentially nobody else uses.
6062 Some versions of gcc come with an assembler post-processor called
6063 mips-tfile. This program is required if you want to do source-level
6064 debugging of gcc-compiled programs. I believe FSF does not ship
6065 mips-tfile with gcc version 1, but it will eventually come with gcc
6068 Debugging of g++ output remains a problem. g++ version 1.xx does not
6069 really support it at all. (If you're lucky, you should be able to get
6070 line numbers and stack traces to work, but no parameters or local
6071 variables.) With some work it should be possible to improve the
6074 When gcc version 2 is released, you will have somewhat better luck.
6075 However, even then you will get confusing results for inheritance and
6078 We will eventually provide full debugging of g++ output on
6079 DECstations. This will probably involve some kind of stabs-in-ecoff
6080 encapulation, but the details have not been worked out yet.
6083 *** Changes in GDB-4.2:
6085 * Improved configuration
6087 Only one copy of `configure' exists now, and it is not self-modifying.
6088 Porting BFD is simpler.
6092 The `step' and `next' commands now only stop at the first instruction
6093 of a source line. This prevents the multiple stops that used to occur
6094 in switch statements, for-loops, etc. `Step' continues to stop if a
6095 function that has debugging information is called within the line.
6099 Lots of small bugs fixed. More remain.
6101 * New host supported (not target)
6103 Intel 386 PC clone running Mach i386-none-mach
6106 *** Changes in GDB-4.1:
6108 * Multiple source language support
6110 GDB now has internal scaffolding to handle several source languages.
6111 It determines the type of each source file from its filename extension,
6112 and will switch expression parsing and number formatting to match the
6113 language of the function in the currently selected stack frame.
6114 You can also specifically set the language to be used, with
6115 `set language c' or `set language modula-2'.
6119 GDB now has preliminary support for the GNU Modula-2 compiler,
6120 currently under development at the State University of New York at
6121 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6122 continue through the fall of 1991 and into 1992.
6124 Other Modula-2 compilers are currently not supported, and attempting to
6125 debug programs compiled with them will likely result in an error as the
6126 symbol table is read. Feel free to work on it, though!
6128 There are hooks in GDB for strict type checking and range checking,
6129 in the `Modula-2 philosophy', but they do not currently work.
6133 GDB can now write to executable and core files (e.g. patch
6134 a variable's value). You must turn this switch on, specify
6135 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6136 by assigning a new value to a variable. Modifications take
6139 * Automatic SunOS shared library reading
6141 When you run your program, GDB automatically determines where its
6142 shared libraries (if any) have been loaded, and reads their symbols.
6143 The `share' command is no longer needed. This also works when
6144 examining core files.
6148 You can specify the number of lines that the `list' command shows.
6151 * New machines supported (host and target)
6153 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6154 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6155 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6157 * New hosts supported (not targets)
6159 IBM RT/PC: romp-ibm-aix or rtpc
6161 * New targets supported (not hosts)
6163 AMD 29000 embedded with COFF a29k-none-coff
6164 AMD 29000 embedded with a.out a29k-none-aout
6165 Ultracomputer remote kernel debug a29k-nyu-kern
6167 * New remote interfaces
6173 *** Changes in GDB-4.0:
6177 Wide output is wrapped at good places to make the output more readable.
6179 Gdb now supports cross-debugging from a host machine of one type to a
6180 target machine of another type. Communication with the target system
6181 is over serial lines. The ``target'' command handles connecting to the
6182 remote system; the ``load'' command will download a program into the
6183 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6184 also supports debugging of realtime processes running under VxWorks,
6185 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6186 stub on the target system.
6188 New CPUs supported include the AMD 29000 and Intel 960.
6190 GDB now reads object files and symbol tables via a ``binary file''
6191 library, which allows a single copy of GDB to debug programs of multiple
6192 object file types such as a.out and coff.
6194 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6195 refcard.dvi and refcard.ps are available to format it).
6198 * Control-Variable user interface simplified
6200 All variables that control the operation of the debugger can be set
6201 by the ``set'' command, and displayed by the ``show'' command.
6203 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6204 ``Show prompt'' produces the response:
6205 Gdb's prompt is new-gdb=>.
6207 What follows are the NEW set commands. The command ``help set'' will
6208 print a complete list of old and new set commands. ``help set FOO''
6209 will give a longer description of the variable FOO. ``show'' will show
6210 all of the variable descriptions and their current settings.
6212 confirm on/off: Enables warning questions for operations that are
6213 hard to recover from, e.g. rerunning the program while
6214 it is already running. Default is ON.
6216 editing on/off: Enables EMACS style command line editing
6217 of input. Previous lines can be recalled with
6218 control-P, the current line can be edited with control-B,
6219 you can search for commands with control-R, etc.
6222 history filename NAME: NAME is where the gdb command history
6223 will be stored. The default is .gdb_history,
6224 or the value of the environment variable
6227 history size N: The size, in commands, of the command history. The
6228 default is 256, or the value of the environment variable
6231 history save on/off: If this value is set to ON, the history file will
6232 be saved after exiting gdb. If set to OFF, the
6233 file will not be saved. The default is OFF.
6235 history expansion on/off: If this value is set to ON, then csh-like
6236 history expansion will be performed on
6237 command line input. The default is OFF.
6239 radix N: Sets the default radix for input and output. It can be set
6240 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6241 in the current radix, so "set radix 10" is always a no-op.
6243 height N: This integer value is the number of lines on a page. Default
6244 is 24, the current `stty rows'' setting, or the ``li#''
6245 setting from the termcap entry matching the environment
6248 width N: This integer value is the number of characters on a line.
6249 Default is 80, the current `stty cols'' setting, or the ``co#''
6250 setting from the termcap entry matching the environment
6253 Note: ``set screensize'' is obsolete. Use ``set height'' and
6254 ``set width'' instead.
6256 print address on/off: Print memory addresses in various command displays,
6257 such as stack traces and structure values. Gdb looks
6258 more ``symbolic'' if you turn this off; it looks more
6259 ``machine level'' with it on. Default is ON.
6261 print array on/off: Prettyprint arrays. New convenient format! Default
6264 print demangle on/off: Print C++ symbols in "source" form if on,
6267 print asm-demangle on/off: Same, for assembler level printouts
6270 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6273 * Support for Epoch Environment.
6275 The epoch environment is a version of Emacs v18 with windowing. One
6276 new command, ``inspect'', is identical to ``print'', except that if you
6277 are running in the epoch environment, the value is printed in its own
6281 * Support for Shared Libraries
6283 GDB can now debug programs and core files that use SunOS shared libraries.
6284 Symbols from a shared library cannot be referenced
6285 before the shared library has been linked with the program (this
6286 happens after you type ``run'' and before the function main() is entered).
6287 At any time after this linking (including when examining core files
6288 from dynamically linked programs), gdb reads the symbols from each
6289 shared library when you type the ``sharedlibrary'' command.
6290 It can be abbreviated ``share''.
6292 sharedlibrary REGEXP: Load shared object library symbols for files
6293 matching a unix regular expression. No argument
6294 indicates to load symbols for all shared libraries.
6296 info sharedlibrary: Status of loaded shared libraries.
6301 A watchpoint stops execution of a program whenever the value of an
6302 expression changes. Checking for this slows down execution
6303 tremendously whenever you are in the scope of the expression, but is
6304 quite useful for catching tough ``bit-spreader'' or pointer misuse
6305 problems. Some machines such as the 386 have hardware for doing this
6306 more quickly, and future versions of gdb will use this hardware.
6308 watch EXP: Set a watchpoint (breakpoint) for an expression.
6310 info watchpoints: Information about your watchpoints.
6312 delete N: Deletes watchpoint number N (same as breakpoints).
6313 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6314 enable N: Re-enables watchpoint number N (same as breakpoints).
6317 * C++ multiple inheritance
6319 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6322 * C++ exception handling
6324 Gdb now supports limited C++ exception handling. Besides the existing
6325 ability to breakpoint on an exception handler, gdb can breakpoint on
6326 the raising of an exception (before the stack is peeled back to the
6329 catch FOO: If there is a FOO exception handler in the dynamic scope,
6330 set a breakpoint to catch exceptions which may be raised there.
6331 Multiple exceptions (``catch foo bar baz'') may be caught.
6333 info catch: Lists all exceptions which may be caught in the
6334 current stack frame.
6337 * Minor command changes
6339 The command ``call func (arg, arg, ...)'' now acts like the print
6340 command, except it does not print or save a value if the function's result
6341 is void. This is similar to dbx usage.
6343 The ``up'' and ``down'' commands now always print the frame they end up
6344 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6345 frames without printing.
6347 * New directory command
6349 'dir' now adds directories to the FRONT of the source search path.
6350 The path starts off empty. Source files that contain debug information
6351 about the directory in which they were compiled can be found even
6352 with an empty path; Sun CC and GCC include this information. If GDB can't
6353 find your source file in the current directory, type "dir .".
6355 * Configuring GDB for compilation
6357 For normal use, type ``./configure host''. See README or gdb.texinfo
6360 GDB now handles cross debugging. If you are remotely debugging between
6361 two different machines, type ``./configure host -target=targ''.
6362 Host is the machine where GDB will run; targ is the machine
6363 where the program that you are debugging will run.