1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.10
6 * The new convenience variable $_inferior holds the number of the
9 * Record btrace now supports non-stop mode.
11 * Support for tracepoints on aarch64-linux was added in GDBserver.
13 * The 'record instruction-history' command now indicates speculative execution
14 when using the Intel Processor Trace recording format.
16 * GDB now allows users to specify explicit locations, bypassing
17 the linespec parser. This feature is also available to GDB/MI
20 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
21 GDB now is able to debug both AArch64 applications and ARM applications
24 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
25 including JIT compiling fast tracepoint's conditional expression bytecode
28 * GDB now supports displaced stepping on AArch64 GNU/Linux.
30 * "info threads", "info inferiors", "info display", "info checkpoints"
31 and "maint info program-spaces" now list the corresponding items in
32 ascending ID order, for consistency with all other "info" commands.
34 * In Ada, the overloads selection menu has been enhanced to display the
35 parameter types and the return types for the matching overloaded subprograms.
39 maint set target-non-stop (on|off|auto)
40 maint show target-non-stop
41 Control whether GDB targets always operate in non-stop mode even if
42 "set non-stop" is "off". The default is "auto", meaning non-stop
43 mode is enabled if supported by the target.
46 maint show bfd-sharing
47 Control the reuse of bfd objects.
51 Control display of debugging info regarding bfd caching.
53 set remote multiprocess-extensions-packet
54 show remote multiprocess-extensions-packet
55 Set/show the use of the remote protocol multiprocess extensions.
57 set remote thread-events
58 show remote thread-events
59 Set/show the use of thread create/exit events.
61 set ada print-signatures on|off
62 show ada print-signatures"
63 Control whether parameter types and return types are displayed in overloads
64 selection menus. It is activaled (@code{on}) by default.
66 * The "disassemble" command accepts a new modifier: /s.
67 It prints mixed source+disassembly like /m with two differences:
68 - disassembled instructions are now printed in program order, and
69 - and source for all relevant files is now printed.
70 The "/m" option is now considered deprecated: its "source-centric"
71 output hasn't proved useful in practice.
73 * The "record instruction-history" command accepts a new modifier: /s.
74 It behaves exactly like /m and prints mixed source+disassembly.
76 * The "set scheduler-locking" command supports a new mode "replay".
77 It behaves like "off" in record mode and like "on" in replay mode.
79 * Support for various ROM monitors has been removed:
81 target dbug dBUG ROM monitor for Motorola ColdFire
82 target picobug Motorola picobug monitor
83 target dink32 DINK32 ROM monitor for PowerPC
84 target m32r Renesas M32R/D ROM monitor
85 target mon2000 mon2000 ROM monitor
86 target ppcbug PPCBUG ROM monitor for PowerPC
88 * Support for reading/writing memory and extracting values on architectures
89 whose memory is addressable in units of any integral multiple of 8 bits.
94 Indicates that an exec system call was executed.
96 exec-events feature in qSupported
97 The qSupported packet allows GDB to request support for exec
98 events using the new 'gdbfeature' exec-event, and the qSupported
99 response can contain the corresponding 'stubfeature'. Set and
100 show commands can be used to display whether these features are enabled.
103 Equivalent to interrupting with the ^C character, but works in
106 thread created stop reason (T05 create:...)
107 Indicates that the thread was just created and is stopped at entry.
109 thread exit stop reply (w exitcode;tid)
110 Indicates that the thread has terminated.
113 Enables/disables thread create and exit event reporting. For
114 example, this is used in non-stop mode when GDB stops a set of
115 threads and synchronously waits for the their corresponding stop
116 replies. Without exit events, if one of the threads exits, GDB
117 would hang forever not knowing that it should no longer expect a
118 stop for that same thread.
122 Indicates that there are no resumed threads left in the target (all
123 threads are stopped). The remote stub reports support for this stop
124 reply to GDB's qSupported query.
126 QCatchSyscalls:1 [;SYSNO]...
128 Enable ("QCatchSyscalls:1") or disable ("QCatchSyscalls:0")
129 catching syscalls from the inferior process.
131 syscall_entry stop reason
132 Indicates that a syscall was just called.
134 syscall_return stop reason
135 Indicates that a syscall just returned.
137 QCatchSyscalls:1 in qSupported
138 The qSupported packet may now include QCatchSyscalls:1 in the reply
139 to indicate support for catching syscalls.
141 * Extended-remote exec events
143 ** GDB now has support for exec events on extended-remote Linux targets.
144 For such targets with Linux kernels 2.5.46 and later, this enables
145 follow-exec-mode and exec catchpoints.
147 set remote exec-event-feature-packet
148 show remote exec-event-feature-packet
149 Set/show the use of the remote exec event feature.
151 * Thread names in remote protocol
153 The reply to qXfer:threads:read may now include a name attribute for each
156 * Target remote mode fork and exec events
158 ** GDB now has support for fork and exec events on target remote mode
159 Linux targets. For such targets with Linux kernels 2.5.46 and later,
160 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
161 fork and exec catchpoints.
163 * Remote syscall events
165 ** GDB now has support for catch syscall on remote Linux targets,
166 currently enabled on x86/x86_64 architectures.
168 set remote catch-syscall-packet
169 show remote catch-syscall-packet
170 Set/show the use of the remote catch syscall feature.
174 ** The -var-set-format command now accepts the zero-hexadecimal
175 format. It outputs data in hexadecimal format with zero-padding on the
180 ** gdb.InferiorThread objects have a new attribute "inferior", which
181 is the Inferior object the thread belongs to.
183 *** Changes in GDB 7.10
185 * Support for process record-replay and reverse debugging on aarch64*-linux*
186 targets has been added. GDB now supports recording of A64 instruction set
187 including advance SIMD instructions.
189 * Support for Sun's version of the "stabs" debug file format has been removed.
191 * GDB now honors the content of the file /proc/PID/coredump_filter
192 (PID is the process ID) on GNU/Linux systems. This file can be used
193 to specify the types of memory mappings that will be included in a
194 corefile. For more information, please refer to the manual page of
195 "core(5)". GDB also has a new command: "set use-coredump-filter
196 on|off". It allows to set whether GDB will read the content of the
197 /proc/PID/coredump_filter file when generating a corefile.
199 * The "info os" command on GNU/Linux can now display information on
201 "info os cpus" Listing of all cpus/cores on the system
203 * GDB has two new commands: "set serial parity odd|even|none" and
204 "show serial parity". These allows to set or show parity for the
207 * The "info source" command now displays the producer string if it was
208 present in the debug info. This typically includes the compiler version
209 and may include things like its command line arguments.
211 * The "info dll", an alias of the "info sharedlibrary" command,
212 is now available on all platforms.
214 * Directory names supplied to the "set sysroot" commands may be
215 prefixed with "target:" to tell GDB to access shared libraries from
216 the target system, be it local or remote. This replaces the prefix
217 "remote:". The default sysroot has been changed from "" to
218 "target:". "remote:" is automatically converted to "target:" for
219 backward compatibility.
221 * The system root specified by "set sysroot" will be prepended to the
222 filename of the main executable (if reported to GDB as absolute by
223 the operating system) when starting processes remotely, and when
224 attaching to already-running local or remote processes.
226 * GDB now supports automatic location and retrieval of executable
227 files from remote targets. Remote debugging can now be initiated
228 using only a "target remote" or "target extended-remote" command
229 (no "set sysroot" or "file" commands are required). See "New remote
232 * The "dump" command now supports verilog hex format.
234 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
236 * On GNU/Linux, GDB and gdbserver are now able to access executable
237 and shared library files without a "set sysroot" command when
238 attaching to processes running in different mount namespaces from
239 the debugger. This makes it possible to attach to processes in
240 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
241 See "New remote packets" below.
243 * The "tui reg" command now provides completion for all of the
244 available register groups, including target specific groups.
246 * The HISTSIZE environment variable is no longer read when determining
247 the size of GDB's command history. GDB now instead reads the dedicated
248 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
249 disables truncation of command history. Non-numeric values of GDBHISTSIZE
254 ** Memory ports can now be unbuffered.
258 ** gdb.Objfile objects have a new attribute "username",
259 which is the name of the objfile as specified by the user,
260 without, for example, resolving symlinks.
261 ** You can now write frame unwinders in Python.
262 ** gdb.Type objects have a new method "optimized_out",
263 returning optimized out gdb.Value instance of this type.
264 ** gdb.Value objects have new methods "reference_value" and
265 "const_value" which return a reference to the value and a
266 "const" version of the value respectively.
270 maint print symbol-cache
271 Print the contents of the symbol cache.
273 maint print symbol-cache-statistics
274 Print statistics of symbol cache usage.
276 maint flush-symbol-cache
277 Flush the contents of the symbol cache.
281 Start branch trace recording using Branch Trace Store (BTS) format.
284 Evaluate expression by using the compiler and print result.
288 Explicit commands for enabling and disabling tui mode.
291 set mpx bound on i386 and amd64
292 Support for bound table investigation on Intel MPX enabled applications.
296 Start branch trace recording using Intel Processor Trace format.
299 Print information about branch tracing internals.
301 maint btrace packet-history
302 Print the raw branch tracing data.
304 maint btrace clear-packet-history
305 Discard the stored raw branch tracing data.
308 Discard all branch tracing data. It will be fetched and processed
309 anew by the next "record" command.
314 Renamed from "set debug dwarf2-die".
316 Renamed from "show debug dwarf2-die".
319 Renamed from "set debug dwarf2-read".
320 show debug dwarf-read
321 Renamed from "show debug dwarf2-read".
323 maint set dwarf always-disassemble
324 Renamed from "maint set dwarf2 always-disassemble".
325 maint show dwarf always-disassemble
326 Renamed from "maint show dwarf2 always-disassemble".
328 maint set dwarf max-cache-age
329 Renamed from "maint set dwarf2 max-cache-age".
330 maint show dwarf max-cache-age
331 Renamed from "maint show dwarf2 max-cache-age".
334 show debug dwarf-line
335 Control display of debugging info regarding DWARF line processing.
339 Set the maximum number of candidates to be considered during
340 completion. The default value is 200. This limit allows GDB
341 to avoid generating large completion lists, the computation of
342 which can cause the debugger to become temporarily unresponsive.
344 set history remove-duplicates
345 show history remove-duplicates
346 Control the removal of duplicate history entries.
348 maint set symbol-cache-size
349 maint show symbol-cache-size
350 Control the size of the symbol cache.
352 set|show record btrace bts buffer-size
353 Set and show the size of the ring buffer used for branch tracing in
355 The obtained size may differ from the requested size. Use "info
356 record" to see the obtained buffer size.
358 set debug linux-namespaces
359 show debug linux-namespaces
360 Control display of debugging info regarding Linux namespaces.
362 set|show record btrace pt buffer-size
363 Set and show the size of the ring buffer used for branch tracing in
364 Intel Processor Trace format.
365 The obtained size may differ from the requested size. Use "info
366 record" to see the obtained buffer size.
368 maint set|show btrace pt skip-pad
369 Set and show whether PAD packets are skipped when computing the
372 * The command 'thread apply all' can now support new option '-ascending'
373 to call its specified command for all threads in ascending order.
375 * Python/Guile scripting
377 ** GDB now supports auto-loading of Python/Guile scripts contained in the
378 special section named `.debug_gdb_scripts'.
382 qXfer:btrace-conf:read
383 Return the branch trace configuration for the current thread.
385 Qbtrace-conf:bts:size
386 Set the requested ring buffer size for branch tracing in BTS format.
389 Enable Intel Procesor Trace-based branch tracing for the current
390 process. The remote stub reports support for this packet to GDB's
394 Set the requested ring buffer size for branch tracing in Intel Processor
398 Indicates a memory breakpoint instruction was executed, irrespective
399 of whether it was GDB that planted the breakpoint or the breakpoint
400 is hardcoded in the program. This is required for correct non-stop
404 Indicates the target stopped for a hardware breakpoint. This is
405 required for correct non-stop mode operation.
408 Return information about files on the remote system.
411 Return the full absolute name of the file that was executed to
412 create a process running on the remote system.
415 Select the filesystem on which vFile: operations with filename
416 arguments will operate. This is required for GDB to be able to
417 access files on remote targets where the remote stub does not
418 share a common filesystem with the inferior(s).
421 Indicates that a fork system call was executed.
424 Indicates that a vfork system call was executed.
426 vforkdone stop reason
427 Indicates that a vfork child of the specified process has executed
428 an exec or exit, allowing the vfork parent to resume execution.
430 fork-events and vfork-events features in qSupported
431 The qSupported packet allows GDB to request support for fork and
432 vfork events using new 'gdbfeatures' fork-events and vfork-events,
433 and the qSupported response can contain the corresponding
434 'stubfeatures'. Set and show commands can be used to display
435 whether these features are enabled.
437 * Extended-remote fork events
439 ** GDB now has support for fork events on extended-remote Linux
440 targets. For targets with Linux kernels 2.5.60 and later, this
441 enables follow-fork-mode and detach-on-fork for both fork and
442 vfork, as well as fork and vfork catchpoints.
444 * The info record command now shows the recording format and the
445 branch tracing configuration for the current thread when using
446 the btrace record target.
447 For the BTS format, it shows the ring buffer size.
449 * GDB now has support for DTrace USDT (Userland Static Defined
450 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
452 * GDB now supports access to vector registers on S/390 GNU/Linux
455 * Removed command line options
457 -xdb HP-UX XDB compatibility mode.
459 * Removed targets and native configurations
461 HP/PA running HP-UX hppa*-*-hpux*
462 Itanium running HP-UX ia64-*-hpux*
464 * New configure options
467 This configure option allows the user to build GDB with support for
468 Intel Processor Trace (default: auto). This requires libipt.
470 --with-libipt-prefix=PATH
471 Specify the path to the version of libipt that GDB should use.
472 $PATH/include should contain the intel-pt.h header and
473 $PATH/lib should contain the libipt.so library.
475 *** Changes in GDB 7.9.1
479 ** Xmethods can now specify a result type.
481 *** Changes in GDB 7.9
483 * GDB now supports hardware watchpoints on x86 GNU Hurd.
487 ** You can now access frame registers from Python scripts.
488 ** New attribute 'producer' for gdb.Symtab objects.
489 ** gdb.Objfile objects have a new attribute "progspace",
490 which is the gdb.Progspace object of the containing program space.
491 ** gdb.Objfile objects have a new attribute "owner".
492 ** gdb.Objfile objects have a new attribute "build_id",
493 which is the build ID generated when the file was built.
494 ** gdb.Objfile objects have a new method "add_separate_debug_file".
495 ** A new event "gdb.clear_objfiles" has been added, triggered when
496 selecting a new file to debug.
497 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
498 ** New function gdb.lookup_objfile.
500 New events which are triggered when GDB modifies the state of the
503 ** gdb.events.inferior_call_pre: Function call is about to be made.
504 ** gdb.events.inferior_call_post: Function call has just been made.
505 ** gdb.events.memory_changed: A memory location has been altered.
506 ** gdb.events.register_changed: A register has been altered.
508 * New Python-based convenience functions:
510 ** $_caller_is(name [, number_of_frames])
511 ** $_caller_matches(regexp [, number_of_frames])
512 ** $_any_caller_is(name [, number_of_frames])
513 ** $_any_caller_matches(regexp [, number_of_frames])
515 * GDB now supports the compilation and injection of source code into
516 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
517 to compile the source code to object code, and if successful, inject
518 and execute that code within the current context of the inferior.
519 Currently the C language is supported. The commands used to
520 interface with this new feature are:
522 compile code [-raw|-r] [--] [source code]
523 compile file [-raw|-r] filename
527 demangle [-l language] [--] name
528 Demangle "name" in the specified language, or the current language
529 if elided. This command is renamed from the "maint demangle" command.
530 The latter is kept as a no-op to avoid "maint demangle" being interpreted
531 as "maint demangler-warning".
533 queue-signal signal-name-or-number
534 Queue a signal to be delivered to the thread when it is resumed.
536 add-auto-load-scripts-directory directory
537 Add entries to the list of directories from which to load auto-loaded
540 maint print user-registers
541 List all currently available "user" registers.
543 compile code [-r|-raw] [--] [source code]
544 Compile, inject, and execute in the inferior the executable object
545 code produced by compiling the provided source code.
547 compile file [-r|-raw] filename
548 Compile and inject into the inferior the executable object code
549 produced by compiling the source code stored in the filename
552 * On resume, GDB now always passes the signal the program had stopped
553 for to the thread the signal was sent to, even if the user changed
554 threads before resuming. Previously GDB would often (but not
555 always) deliver the signal to the thread that happens to be current
558 * Conversely, the "signal" command now consistently delivers the
559 requested signal to the current thread. GDB now asks for
560 confirmation if the program had stopped for a signal and the user
561 switched threads meanwhile.
563 * "breakpoint always-inserted" modes "off" and "auto" merged.
565 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
566 won't remove breakpoints from the target until all threads stop,
567 even in non-stop mode. The "auto" mode has been removed, and "off"
568 is now the default mode.
572 set debug symbol-lookup
573 show debug symbol-lookup
574 Control display of debugging info regarding symbol lookup.
578 ** The -list-thread-groups command outputs an exit-code field for
579 inferiors that have exited.
583 MIPS SDE mips*-sde*-elf*
587 Support for these obsolete configurations has been removed.
589 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
590 SGI Irix-5.x mips-*-irix5*
591 SGI Irix-6.x mips-*-irix6*
592 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
593 VAX running Ultrix vax-*-ultrix*
595 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
596 and "assf"), have been removed. Use the "sharedlibrary" command, or
597 its alias "share", instead.
599 *** Changes in GDB 7.8
601 * New command line options
604 This is an alias for the --data-directory option.
606 * GDB supports printing and modifying of variable length automatic arrays
607 as specified in ISO C99.
609 * The ARM simulator now supports instruction level tracing
610 with or without disassembly.
614 GDB now has support for scripting using Guile. Whether this is
615 available is determined at configure time.
616 Guile version 2.0 or greater is required.
617 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
619 * New commands (for set/show, see "New options" below)
623 Invoke CODE by passing it to the Guile interpreter.
627 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
629 info auto-load guile-scripts [regexp]
630 Print the list of automatically loaded Guile scripts.
632 * The source command is now capable of sourcing Guile scripts.
633 This feature is dependent on the debugger being built with Guile support.
637 set print symbol-loading (off|brief|full)
638 show print symbol-loading
639 Control whether to print informational messages when loading symbol
640 information for a file. The default is "full", but when debugging
641 programs with large numbers of shared libraries the amount of output
644 set guile print-stack (none|message|full)
645 show guile print-stack
646 Show a stack trace when an error is encountered in a Guile script.
648 set auto-load guile-scripts (on|off)
649 show auto-load guile-scripts
650 Control auto-loading of Guile script files.
652 maint ada set ignore-descriptive-types (on|off)
653 maint ada show ignore-descriptive-types
654 Control whether the debugger should ignore descriptive types in Ada
655 programs. The default is not to ignore the descriptive types. See
656 the user manual for more details on descriptive types and the intended
657 usage of this option.
659 set auto-connect-native-target
661 Control whether GDB is allowed to automatically connect to the
662 native target for the run, attach, etc. commands when not connected
663 to any target yet. See also "target native" below.
665 set record btrace replay-memory-access (read-only|read-write)
666 show record btrace replay-memory-access
667 Control what memory accesses are allowed during replay.
669 maint set target-async (on|off)
670 maint show target-async
671 This controls whether GDB targets operate in synchronous or
672 asynchronous mode. Normally the default is asynchronous, if it is
673 available; but this can be changed to more easily debug problems
674 occurring only in synchronous mode.
676 set mi-async (on|off)
678 Control whether MI asynchronous mode is preferred. This supersedes
679 "set target-async" of previous GDB versions.
681 * "set target-async" is deprecated as a CLI option and is now an alias
682 for "set mi-async" (only puts MI into async mode).
684 * Background execution commands (e.g., "c&", "s&", etc.) are now
685 possible ``out of the box'' if the target supports them. Previously
686 the user would need to explicitly enable the possibility with the
687 "set target-async on" command.
689 * New features in the GDB remote stub, GDBserver
691 ** New option --debug-format=option1[,option2,...] allows one to add
692 additional text to each output. At present only timestamps
693 are supported: --debug-format=timestamps.
694 Timestamps can also be turned on with the
695 "monitor set debug-format timestamps" command from GDB.
697 * The 'record instruction-history' command now starts counting instructions
698 at one. This also affects the instruction ranges reported by the
699 'record function-call-history' command when given the /i modifier.
701 * The command 'record function-call-history' supports a new modifier '/c' to
702 indent the function names based on their call stack depth.
703 The fields for the '/i' and '/l' modifier have been reordered.
704 The source line range is now prefixed with 'at'.
705 The instruction range is now prefixed with 'inst'.
706 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
707 "record instruction-history" and "list" commands.
709 * The ranges given as arguments to the 'record function-call-history' and
710 'record instruction-history' commands are now inclusive.
712 * The btrace record target now supports the 'record goto' command.
713 For locations inside the execution trace, the back trace is computed
714 based on the information stored in the execution trace.
716 * The btrace record target supports limited reverse execution and replay.
717 The target does not record data and therefore does not allow reading
720 * The "catch syscall" command now works on s390*-linux* targets.
722 * The "compare-sections" command is no longer specific to target
723 remote. It now works with all targets.
725 * All native targets are now consistently called "native".
726 Consequently, the "target child", "target GNU", "target djgpp",
727 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
728 commands have been replaced with "target native". The QNX/NTO port
729 leaves the "procfs" target in place and adds a "native" target for
730 consistency with other ports. The impact on users should be minimal
731 as these commands previously either throwed an error, or were
732 no-ops. The target's name is visible in the output of the following
733 commands: "help target", "info target", "info files", "maint print
736 * The "target native" command now connects to the native target. This
737 can be used to launch native programs even when "set
738 auto-connect-native-target" is set to off.
740 * GDB now supports access to Intel MPX registers on GNU/Linux.
742 * Support for Intel AVX-512 registers on GNU/Linux.
743 Support displaying and modifying Intel AVX-512 registers
744 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
748 qXfer:btrace:read's annex
749 The qXfer:btrace:read packet supports a new annex 'delta' to read
750 branch trace incrementally.
754 ** Valid Python operations on gdb.Value objects representing
755 structs/classes invoke the corresponding overloaded operators if
757 ** New `Xmethods' feature in the Python API. Xmethods are
758 additional methods or replacements for existing methods of a C++
759 class. This feature is useful for those cases where a method
760 defined in C++ source code could be inlined or optimized out by
761 the compiler, making it unavailable to GDB.
764 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
766 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
767 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
768 its alias "share", instead.
770 * The commands "set remotebaud" and "show remotebaud" are no longer
771 supported. Use "set serial baud" and "show serial baud" (respectively)
776 ** A new option "-gdb-set mi-async" replaces "-gdb-set
777 target-async". The latter is left as a deprecated alias of the
778 former for backward compatibility. If the target supports it,
779 CLI background execution commands are now always possible by
780 default, independently of whether the frontend stated a
781 preference for asynchronous execution with "-gdb-set mi-async".
782 Previously "-gdb-set target-async off" affected both MI execution
783 commands and CLI execution commands.
785 *** Changes in GDB 7.7
787 * Improved support for process record-replay and reverse debugging on
788 arm*-linux* targets. Support for thumb32 and syscall instruction
789 recording has been added.
791 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
793 * GDB now supports Fission DWP file format version 2.
794 http://gcc.gnu.org/wiki/DebugFission
796 * New convenience function "$_isvoid", to check whether an expression
797 is void. A void expression is an expression where the type of the
798 result is "void". For example, some convenience variables may be
799 "void" when evaluated (e.g., "$_exitcode" before the execution of
800 the program being debugged; or an undefined convenience variable).
801 Another example, when calling a function whose return type is
804 * The "maintenance print objfiles" command now takes an optional regexp.
806 * The "catch syscall" command now works on arm*-linux* targets.
808 * GDB now consistently shows "<not saved>" when printing values of
809 registers the debug info indicates have not been saved in the frame
810 and there's nowhere to retrieve them from
811 (callee-saved/call-clobbered registers):
816 (gdb) info registers rax
819 Before, the former would print "<optimized out>", and the latter
820 "*value not available*".
822 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
827 ** Frame filters and frame decorators have been added.
828 ** Temporary breakpoints are now supported.
829 ** Line tables representation has been added.
830 ** New attribute 'parent_type' for gdb.Field objects.
831 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
832 ** New attribute 'name' for gdb.Type objects.
836 Nios II ELF nios2*-*-elf
837 Nios II GNU/Linux nios2*-*-linux
838 Texas Instruments MSP430 msp430*-*-elf
840 * Removed native configurations
842 Support for these a.out NetBSD and OpenBSD obsolete configurations has
843 been removed. ELF variants of these configurations are kept supported.
845 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
846 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
847 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
848 i[34567]86-*-openbsd3.[0-3]
849 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
850 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
851 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
855 Like "catch throw", but catches a re-thrown exception.
857 Renamed from old "maint check-symtabs".
859 Perform consistency checks on symtabs.
861 Expand symtabs matching an optional regexp.
864 Display the details of GDB configure-time options.
866 maint set|show per-command
867 maint set|show per-command space
868 maint set|show per-command time
869 maint set|show per-command symtab
870 Enable display of per-command gdb resource usage.
872 remove-symbol-file FILENAME
873 remove-symbol-file -a ADDRESS
874 Remove a symbol file added via add-symbol-file. The file to remove
875 can be identified by its filename or by an address that lies within
876 the boundaries of this symbol file in memory.
879 info exceptions REGEXP
880 Display the list of Ada exceptions defined in the program being
881 debugged. If provided, only the exceptions whose names match REGEXP
886 set debug symfile off|on
888 Control display of debugging info regarding reading symbol files and
889 symbol tables within those files
891 set print raw frame-arguments
892 show print raw frame-arguments
893 Set/show whether to print frame arguments in raw mode,
894 disregarding any defined pretty-printers.
896 set remote trace-status-packet
897 show remote trace-status-packet
898 Set/show the use of remote protocol qTStatus packet.
902 Control display of debugging messages related to Nios II targets.
906 Control whether target-assisted range stepping is enabled.
908 set startup-with-shell
909 show startup-with-shell
910 Specifies whether Unix child processes are started via a shell or
915 Use the target memory cache for accesses to the code segment. This
916 improves performance of remote debugging (particularly disassembly).
918 * You can now use a literal value 'unlimited' for options that
919 interpret 0 or -1 as meaning "unlimited". E.g., "set
920 trace-buffer-size unlimited" is now an alias for "set
921 trace-buffer-size -1" and "set height unlimited" is now an alias for
924 * The "set debug symtab-create" debugging option of GDB has been changed to
925 accept a verbosity level. 0 means "off", 1 provides basic debugging
926 output, and values of 2 or greater provides more verbose output.
928 * New command-line options
930 Display the details of GDB configure-time options.
932 * The command 'tsave' can now support new option '-ctf' to save trace
933 buffer in Common Trace Format.
935 * Newly installed $prefix/bin/gcore acts as a shell interface for the
938 * GDB now implements the the C++ 'typeid' operator.
940 * The new convenience variable $_exception holds the exception being
941 thrown or caught at an exception-related catchpoint.
943 * The exception-related catchpoints, like "catch throw", now accept a
944 regular expression which can be used to filter exceptions by type.
946 * The new convenience variable $_exitsignal is automatically set to
947 the terminating signal number when the program being debugged dies
948 due to an uncaught signal.
952 ** All MI commands now accept an optional "--language" option.
953 Support for this feature can be verified by using the "-list-features"
954 command, which should contain "language-option".
956 ** The new command -info-gdb-mi-command allows the user to determine
957 whether a GDB/MI command is supported or not.
959 ** The "^error" result record returned when trying to execute an undefined
960 GDB/MI command now provides a variable named "code" whose content is the
961 "undefined-command" error code. Support for this feature can be verified
962 by using the "-list-features" command, which should contain
963 "undefined-command-error-code".
965 ** The -trace-save MI command can optionally save trace buffer in Common
968 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
970 ** The command -data-list-register-values now accepts an optional
971 "--skip-unavailable" option. When used, only the available registers
974 ** The new command -trace-frame-collected dumps collected variables,
975 computed expressions, tvars, memory and registers in a traceframe.
977 ** The commands -stack-list-locals, -stack-list-arguments and
978 -stack-list-variables now accept an option "--skip-unavailable".
979 When used, only the available locals or arguments are displayed.
981 ** The -exec-run command now accepts an optional "--start" option.
982 When used, the command follows the same semantics as the "start"
983 command, stopping the program's execution at the start of its
984 main subprogram. Support for this feature can be verified using
985 the "-list-features" command, which should contain
986 "exec-run-start-option".
988 ** The new commands -catch-assert and -catch-exceptions insert
989 catchpoints stopping the program when Ada exceptions are raised.
991 ** The new command -info-ada-exceptions provides the equivalent of
992 the new "info exceptions" command.
994 * New system-wide configuration scripts
995 A GDB installation now provides scripts suitable for use as system-wide
996 configuration scripts for the following systems:
1000 * GDB now supports target-assigned range stepping with remote targets.
1001 This improves the performance of stepping source lines by reducing
1002 the number of control packets from/to GDB. See "New remote packets"
1005 * GDB now understands the element 'tvar' in the XML traceframe info.
1006 It has the id of the collected trace state variables.
1008 * On S/390 targets that provide the transactional-execution feature,
1009 the program interruption transaction diagnostic block (TDB) is now
1010 represented as a number of additional "registers" in GDB.
1012 * New remote packets
1016 The vCont packet supports a new 'r' action, that tells the remote
1017 stub to step through an address range itself, without GDB
1018 involvemement at each single-step.
1020 qXfer:libraries-svr4:read's annex
1021 The previously unused annex of the qXfer:libraries-svr4:read packet
1022 is now used to support passing an argument list. The remote stub
1023 reports support for this argument list to GDB's qSupported query.
1024 The defined arguments are "start" and "prev", used to reduce work
1025 necessary for library list updating, resulting in significant
1028 * New features in the GDB remote stub, GDBserver
1030 ** GDBserver now supports target-assisted range stepping. Currently
1031 enabled on x86/x86_64 GNU/Linux targets.
1033 ** GDBserver now adds element 'tvar' in the XML in the reply to
1034 'qXfer:traceframe-info:read'. It has the id of the collected
1035 trace state variables.
1037 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1040 * New 'z' formatter for printing and examining memory, this displays the
1041 value as hexadecimal zero padded on the left to the size of the type.
1043 * GDB can now use Windows x64 unwinding data.
1045 * The "set remotebaud" command has been replaced by "set serial baud".
1046 Similarly, "show remotebaud" has been replaced by "show serial baud".
1047 The "set remotebaud" and "show remotebaud" commands are still available
1048 to provide backward compatibility with older versions of GDB.
1050 *** Changes in GDB 7.6
1052 * Target record has been renamed to record-full.
1053 Record/replay is now enabled with the "record full" command.
1054 This also affects settings that are associated with full record/replay
1055 that have been moved from "set/show record" to "set/show record full":
1057 set|show record full insn-number-max
1058 set|show record full stop-at-limit
1059 set|show record full memory-query
1061 * A new record target "record-btrace" has been added. The new target
1062 uses hardware support to record the control-flow of a process. It
1063 does not support replaying the execution, but it implements the
1064 below new commands for investigating the recorded execution log.
1065 This new recording method can be enabled using:
1069 The "record-btrace" target is only available on Intel Atom processors
1070 and requires a Linux kernel 2.6.32 or later.
1072 * Two new commands have been added for record/replay to give information
1073 about the recorded execution without having to replay the execution.
1074 The commands are only supported by "record btrace".
1076 record instruction-history prints the execution history at
1077 instruction granularity
1079 record function-call-history prints the execution history at
1080 function granularity
1082 * New native configurations
1084 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1085 FreeBSD/powerpc powerpc*-*-freebsd
1086 x86_64/Cygwin x86_64-*-cygwin*
1087 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1091 ARM AArch64 aarch64*-*-elf
1092 ARM AArch64 GNU/Linux aarch64*-*-linux
1093 Lynx 178 PowerPC powerpc-*-lynx*178
1094 x86_64/Cygwin x86_64-*-cygwin*
1095 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1097 * If the configured location of system.gdbinit file (as given by the
1098 --with-system-gdbinit option at configure time) is in the
1099 data-directory (as specified by --with-gdb-datadir at configure
1100 time) or in one of its subdirectories, then GDB will look for the
1101 system-wide init file in the directory specified by the
1102 --data-directory command-line option.
1104 * New command line options:
1106 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1107 other initialization files, unlike -nx which disables all of them.
1109 * Removed command line options
1111 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1114 * The 'ptype' and 'whatis' commands now accept an argument to control
1117 * 'info proc' now works on some core files.
1121 ** Vectors can be created with gdb.Type.vector.
1123 ** Python's atexit.register now works in GDB.
1125 ** Types can be pretty-printed via a Python API.
1127 ** Python 3 is now supported (in addition to Python 2.4 or later)
1129 ** New class gdb.Architecture exposes GDB's internal representation
1130 of architecture in the Python API.
1132 ** New method Frame.architecture returns the gdb.Architecture object
1133 corresponding to the frame's architecture.
1135 * New Python-based convenience functions:
1137 ** $_memeq(buf1, buf2, length)
1138 ** $_streq(str1, str2)
1140 ** $_regex(str, regex)
1142 * The 'cd' command now defaults to using '~' (the home directory) if not
1145 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1146 default for GCC since November 2000.
1148 * The command 'forward-search' can now be abbreviated as 'fo'.
1150 * The command 'info tracepoints' can now display 'installed on target'
1151 or 'not installed on target' for each non-pending location of tracepoint.
1153 * New configure options
1155 --enable-libmcheck/--disable-libmcheck
1156 By default, development versions are built with -lmcheck on hosts
1157 that support it, in order to help track memory corruption issues.
1158 Release versions, on the other hand, are built without -lmcheck
1159 by default. The --enable-libmcheck/--disable-libmcheck configure
1160 options allow the user to override that default.
1161 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1162 This configure option allows the user to build GDB with
1163 libbabeltrace using which GDB can read Common Trace Format data.
1165 * New commands (for set/show, see "New options" below)
1168 Catch signals. This is similar to "handle", but allows commands and
1169 conditions to be attached.
1172 List the BFDs known to GDB.
1174 python-interactive [command]
1176 Start a Python interactive prompt, or evaluate the optional command
1177 and print the result of expressions.
1180 "py" is a new alias for "python".
1182 enable type-printer [name]...
1183 disable type-printer [name]...
1184 Enable or disable type printers.
1188 ** For the Renesas Super-H architecture, the "regs" command has been removed
1189 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1194 set print type methods (on|off)
1195 show print type methods
1196 Control whether method declarations are displayed by "ptype".
1197 The default is to show them.
1199 set print type typedefs (on|off)
1200 show print type typedefs
1201 Control whether typedef definitions are displayed by "ptype".
1202 The default is to show them.
1204 set filename-display basename|relative|absolute
1205 show filename-display
1206 Control the way in which filenames is displayed.
1207 The default is "relative", which preserves previous behavior.
1209 set trace-buffer-size
1210 show trace-buffer-size
1211 Request target to change the size of trace buffer.
1213 set remote trace-buffer-size-packet auto|on|off
1214 show remote trace-buffer-size-packet
1215 Control the use of the remote protocol `QTBuffer:size' packet.
1219 Control display of debugging messages related to ARM AArch64.
1222 set debug coff-pe-read
1223 show debug coff-pe-read
1224 Control display of debugging messages related to reading of COFF/PE
1229 Control display of debugging messages related to Mach-O symbols
1232 set debug notification
1233 show debug notification
1234 Control display of debugging info for async remote notification.
1238 ** Command parameter changes are now notified using new async record
1239 "=cmd-param-changed".
1240 ** Trace frame changes caused by command "tfind" are now notified using
1241 new async record "=traceframe-changed".
1242 ** The creation, deletion and modification of trace state variables
1243 are now notified using new async records "=tsv-created",
1244 "=tsv-deleted" and "=tsv-modified".
1245 ** The start and stop of process record are now notified using new
1246 async record "=record-started" and "=record-stopped".
1247 ** Memory changes are now notified using new async record
1249 ** The data-disassemble command response will include a "fullname" field
1250 containing the absolute file name when source has been requested.
1251 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1252 command, to allow pattern filling of memory areas.
1253 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1254 library load/unload events.
1255 ** The response to breakpoint commands and breakpoint async records
1256 includes an "installed" field containing a boolean state about each
1257 non-pending tracepoint location is whether installed on target or not.
1258 ** Output of the "-trace-status" command includes a "trace-file" field
1259 containing the name of the trace file being examined. This field is
1260 optional, and only present when examining a trace file.
1261 ** The "fullname" field is now always present along with the "file" field,
1262 even if the file cannot be found by GDB.
1264 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1265 You must have the LZMA library available when configuring GDB for this
1266 feature to be enabled. For more information, see:
1267 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1269 * New remote packets
1272 Set the size of trace buffer. The remote stub reports support for this
1273 packet to gdb's qSupported query.
1276 Enable Branch Trace Store (BTS)-based branch tracing for the current
1277 thread. The remote stub reports support for this packet to gdb's
1281 Disable branch tracing for the current thread. The remote stub reports
1282 support for this packet to gdb's qSupported query.
1285 Read the traced branches for the current thread. The remote stub
1286 reports support for this packet to gdb's qSupported query.
1288 *** Changes in GDB 7.5
1290 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1291 for more x32 ABI info.
1293 * GDB now supports access to MIPS DSP registers on Linux targets.
1295 * GDB now supports debugging microMIPS binaries.
1297 * The "info os" command on GNU/Linux can now display information on
1298 several new classes of objects managed by the operating system:
1299 "info os procgroups" lists process groups
1300 "info os files" lists file descriptors
1301 "info os sockets" lists internet-domain sockets
1302 "info os shm" lists shared-memory regions
1303 "info os semaphores" lists semaphores
1304 "info os msg" lists message queues
1305 "info os modules" lists loaded kernel modules
1307 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1308 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1309 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1310 options and inspect the probe arguments using the new $_probe_arg family
1311 of convenience variables. You can obtain more information about SystemTap
1312 in <http://sourceware.org/systemtap/>.
1314 * GDB now supports reversible debugging on ARM, it allows you to
1315 debug basic ARM and THUMB instructions, and provides
1316 record/replay support.
1318 * The option "symbol-reloading" has been deleted as it is no longer used.
1322 ** GDB commands implemented in Python can now be put in command class
1325 ** The "maint set python print-stack on|off" is now deleted.
1327 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1328 apply "flag enum"-style pretty-printing to any enum.
1330 ** gdb.lookup_symbol can now work when there is no current frame.
1332 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1333 the source at which the symbol was defined.
1335 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1336 method 'value'. The former indicates whether the symbol needs a
1337 frame in order to compute its value, and the latter computes the
1340 ** A new method 'referenced_value' on gdb.Value objects which can
1341 dereference pointer as well as C++ reference values.
1343 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1344 which return the global and static blocks (as gdb.Block objects),
1345 of the underlying symbol table, respectively.
1347 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1348 object associated with a PC value.
1350 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1351 of the address range occupied by code for the current source line.
1353 * Go language support.
1354 GDB now supports debugging programs written in the Go programming
1357 * GDBserver now supports stdio connections.
1358 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1360 * The binary "gdbtui" can no longer be built or installed.
1361 Use "gdb -tui" instead.
1363 * GDB will now print "flag" enums specially. A flag enum is one where
1364 all the enumerator values have no bits in common when pairwise
1365 "and"ed. When printing a value whose type is a flag enum, GDB will
1366 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1367 (gdb) print (enum E) 3
1370 * The filename part of a linespec will now match trailing components
1371 of a source file name. For example, "break gcc/expr.c:1000" will
1372 now set a breakpoint in build/gcc/expr.c, but not
1373 build/libcpp/expr.c.
1375 * The "info proc" and "generate-core-file" commands will now also
1376 work on remote targets connected to GDBserver on Linux.
1378 * The command "info catch" has been removed. It has been disabled
1379 since December 2007.
1381 * The "catch exception" and "catch assert" commands now accept
1382 a condition at the end of the command, much like the "break"
1383 command does. For instance:
1385 (gdb) catch exception Constraint_Error if Barrier = True
1387 Previously, it was possible to add a condition to such catchpoints,
1388 but it had to be done as a second step, after the catchpoint had been
1389 created, using the "condition" command.
1391 * The "info static-tracepoint-marker" command will now also work on
1392 native Linux targets with in-process agent.
1394 * GDB can now set breakpoints on inlined functions.
1396 * The .gdb_index section has been updated to include symbols for
1397 inlined functions. GDB will ignore older .gdb_index sections by
1398 default, which could cause symbol files to be loaded more slowly
1399 until their .gdb_index sections can be recreated. The new command
1400 "set use-deprecated-index-sections on" will cause GDB to use any older
1401 .gdb_index sections it finds. This will restore performance, but the
1402 ability to set breakpoints on inlined functions will be lost in symbol
1403 files with older .gdb_index sections.
1405 The .gdb_index section has also been updated to record more information
1406 about each symbol. This speeds up the "info variables", "info functions"
1407 and "info types" commands when used with programs having the .gdb_index
1408 section, as well as speeding up debugging with shared libraries using
1409 the .gdb_index section.
1411 * Ada support for GDB/MI Variable Objects has been added.
1413 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1418 ** New command -info-os is the MI equivalent of "info os".
1420 ** Output logs ("set logging" and related) now include MI output.
1424 ** "set use-deprecated-index-sections on|off"
1425 "show use-deprecated-index-sections on|off"
1426 Controls the use of deprecated .gdb_index sections.
1428 ** "catch load" and "catch unload" can be used to stop when a shared
1429 library is loaded or unloaded, respectively.
1431 ** "enable count" can be used to auto-disable a breakpoint after
1434 ** "info vtbl" can be used to show the virtual method tables for
1435 C++ and Java objects.
1437 ** "explore" and its sub commands "explore value" and "explore type"
1438 can be used to recursively explore values and types of
1439 expressions. These commands are available only if GDB is
1440 configured with '--with-python'.
1442 ** "info auto-load" shows status of all kinds of auto-loaded files,
1443 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1444 sequences of commands files, "info auto-load python-scripts"
1445 shows status of auto-loading Python script files,
1446 "info auto-load local-gdbinit" shows status of loading init file
1447 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1448 status of inferior specific thread debugging shared library loading.
1450 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1451 and "show auto-load-scripts" commands have been deprecated, use their
1452 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1453 and "show auto-load python-scripts" counterparts instead.
1455 ** "dprintf location,format,args..." creates a dynamic printf, which
1456 is basically a breakpoint that does a printf and immediately
1457 resumes your program's execution, so it is like a printf that you
1458 can insert dynamically at runtime instead of at compiletime.
1460 ** "set print symbol"
1462 Controls whether GDB attempts to display the symbol, if any,
1463 corresponding to addresses it prints. This defaults to "on", but
1464 you can set it to "off" to restore GDB's previous behavior.
1466 * Deprecated commands
1468 ** For the Renesas Super-H architecture, the "regs" command has been
1469 deprecated, and "info all-registers" should be used instead.
1473 Renesas RL78 rl78-*-elf
1474 HP OpenVMS ia64 ia64-hp-openvms*
1476 * GDBserver supports evaluation of breakpoint conditions. When
1477 support is advertised by GDBserver, GDB may be told to send the
1478 breakpoint conditions in bytecode form to GDBserver. GDBserver
1479 will only report the breakpoint trigger to GDB when its condition
1484 set mips compression
1485 show mips compression
1486 Select the compressed ISA encoding used in functions that have no symbol
1487 information available. The encoding can be set to either of:
1490 and is updated automatically from ELF file flags if available.
1492 set breakpoint condition-evaluation
1493 show breakpoint condition-evaluation
1494 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1495 GDBserver ("target"). Default option "auto" chooses the most efficient
1497 This option can improve debugger efficiency depending on the speed of the
1501 Disable auto-loading globally.
1504 Show auto-loading setting of all kinds of auto-loaded files.
1506 set auto-load gdb-scripts on|off
1507 show auto-load gdb-scripts
1508 Control auto-loading of GDB canned sequences of commands files.
1510 set auto-load python-scripts on|off
1511 show auto-load python-scripts
1512 Control auto-loading of Python script files.
1514 set auto-load local-gdbinit on|off
1515 show auto-load local-gdbinit
1516 Control loading of init file (.gdbinit) from current directory.
1518 set auto-load libthread-db on|off
1519 show auto-load libthread-db
1520 Control auto-loading of inferior specific thread debugging shared library.
1522 set auto-load scripts-directory <dir1>[:<dir2>...]
1523 show auto-load scripts-directory
1524 Set a list of directories from which to load auto-loaded scripts.
1525 Automatically loaded Python scripts and GDB scripts are located in one
1526 of the directories listed by this option.
1527 The delimiter (':' above) may differ according to the host platform.
1529 set auto-load safe-path <dir1>[:<dir2>...]
1530 show auto-load safe-path
1531 Set a list of directories from which it is safe to auto-load files.
1532 The delimiter (':' above) may differ according to the host platform.
1534 set debug auto-load on|off
1535 show debug auto-load
1536 Control display of debugging info for auto-loading the files above.
1538 set dprintf-style gdb|call|agent
1540 Control the way in which a dynamic printf is performed; "gdb"
1541 requests a GDB printf command, while "call" causes dprintf to call a
1542 function in the inferior. "agent" requests that the target agent
1543 (such as GDBserver) do the printing.
1545 set dprintf-function <expr>
1546 show dprintf-function
1547 set dprintf-channel <expr>
1548 show dprintf-channel
1549 Set the function and optional first argument to the call when using
1550 the "call" style of dynamic printf.
1552 set disconnected-dprintf on|off
1553 show disconnected-dprintf
1554 Control whether agent-style dynamic printfs continue to be in effect
1555 after GDB disconnects.
1557 * New configure options
1559 --with-auto-load-dir
1560 Configure default value for the 'set auto-load scripts-directory'
1561 setting above. It defaults to '$debugdir:$datadir/auto-load',
1562 $debugdir representing global debugging info directories (available
1563 via 'show debug-file-directory') and $datadir representing GDB's data
1564 directory (available via 'show data-directory').
1566 --with-auto-load-safe-path
1567 Configure default value for the 'set auto-load safe-path' setting
1568 above. It defaults to the --with-auto-load-dir setting.
1570 --without-auto-load-safe-path
1571 Set 'set auto-load safe-path' to '/', effectively disabling this
1574 * New remote packets
1576 z0/z1 conditional breakpoints extension
1578 The z0/z1 breakpoint insertion packets have been extended to carry
1579 a list of conditional expressions over to the remote stub depending on the
1580 condition evaluation mode. The use of this extension can be controlled
1581 via the "set remote conditional-breakpoints-packet" command.
1585 Specify the signals which the remote stub may pass to the debugged
1586 program without GDB involvement.
1588 * New command line options
1590 --init-command=FILE, -ix Like --command, -x but execute it
1591 before loading inferior.
1592 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1593 execute it before loading inferior.
1595 *** Changes in GDB 7.4
1597 * GDB now handles ambiguous linespecs more consistently; the existing
1598 FILE:LINE support has been expanded to other types of linespecs. A
1599 breakpoint will now be set on all matching locations in all
1600 inferiors, and locations will be added or removed according to
1603 * GDB now allows you to skip uninteresting functions and files when
1604 stepping with the "skip function" and "skip file" commands.
1606 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1607 and "show remote hardware-watchpoint-length-limit". These allows to
1608 set or show the maximum length limit (in bytes) of a remote
1609 target hardware watchpoint.
1611 This allows e.g. to use "unlimited" hardware watchpoints with the
1612 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1613 watchpoints are slower than real hardware watchpoints but are
1614 significantly faster than gdb software watchpoints.
1618 ** The register_pretty_printer function in module gdb.printing now takes
1619 an optional `replace' argument. If True, the new printer replaces any
1622 ** The "maint set python print-stack on|off" command has been
1623 deprecated and will be deleted in GDB 7.5.
1624 A new command: "set python print-stack none|full|message" has
1625 replaced it. Additionally, the default for "print-stack" is
1626 now "message", which just prints the error message without
1629 ** A prompt substitution hook (prompt_hook) is now available to the
1632 ** A new Python module, gdb.prompt has been added to the GDB Python
1633 modules library. This module provides functionality for
1634 escape sequences in prompts (used by set/show
1635 extended-prompt). These escape sequences are replaced by their
1636 corresponding value.
1638 ** Python commands and convenience-functions located in
1639 'data-directory'/python/gdb/command and
1640 'data-directory'/python/gdb/function are now automatically loaded
1643 ** Blocks now provide four new attributes. global_block and
1644 static_block will return the global and static blocks
1645 respectively. is_static and is_global are boolean attributes
1646 that indicate if the block is one of those two types.
1648 ** Symbols now provide the "type" attribute, the type of the symbol.
1650 ** The "gdb.breakpoint" function has been deprecated in favor of
1653 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1654 of a function. This class is based on the "finish" command
1655 available in the CLI.
1657 ** Type objects for struct and union types now allow access to
1658 the fields using standard Python dictionary (mapping) methods.
1659 For example, "some_type['myfield']" now works, as does
1660 "some_type.items()".
1662 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1665 ** A new function, "deep_items" has been added to the gdb.types
1666 module in the GDB Python modules library. This function returns
1667 an iterator over the fields of a struct or union type. Unlike
1668 the standard Python "iteritems" method, it will recursively traverse
1669 any anonymous fields.
1673 ** "*stopped" events can report several new "reason"s, such as
1676 ** Breakpoint changes are now notified using new async records, like
1677 "=breakpoint-modified".
1679 ** New command -ada-task-info.
1681 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1682 $sdir specifies the default system locations of shared libraries.
1683 $pdir specifies the directory where the libpthread used by the application
1686 GDB no longer looks in $sdir and $pdir after it has searched the directories
1687 mentioned in libthread-db-search-path. If you want to search those
1688 directories, they must be specified in libthread-db-search-path.
1689 The default value of libthread-db-search-path on GNU/Linux and Solaris
1690 systems is now "$sdir:$pdir".
1692 $pdir is not supported by gdbserver, it is currently ignored.
1693 $sdir is supported by gdbserver.
1695 * New configure option --with-iconv-bin.
1696 When using the internationalization support like the one in the GNU C
1697 library, GDB will invoke the "iconv" program to get a list of supported
1698 character sets. If this program lives in a non-standard location, one can
1699 use this option to specify where to find it.
1701 * When natively debugging programs on PowerPC BookE processors running
1702 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1703 watchpoints, which specify a mask in addition to an address to watch.
1704 The mask specifies that some bits of an address (the bits which are
1705 reset in the mask) should be ignored when matching the address accessed
1706 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1707 section in the user manual for more details.
1709 * The new option --once causes GDBserver to stop listening for connections once
1710 the first connection is made. The listening port used by GDBserver will
1711 become available after that.
1713 * New commands "info macros" and "alias" have been added.
1715 * New function parameters suffix @entry specifies value of function parameter
1716 at the time the function got called. Entry values are available only since
1722 "!" is now an alias of the "shell" command.
1723 Note that no space is needed between "!" and SHELL COMMAND.
1727 watch EXPRESSION mask MASK_VALUE
1728 The watch command now supports the mask argument which allows creation
1729 of masked watchpoints, if the current architecture supports this feature.
1731 info auto-load-scripts [REGEXP]
1732 This command was formerly named "maintenance print section-scripts".
1733 It is now generally useful and is no longer a maintenance-only command.
1735 info macro [-all] [--] MACRO
1736 The info macro command has new options `-all' and `--'. The first for
1737 printing all definitions of a macro. The second for explicitly specifying
1738 the end of arguments and the beginning of the macro name in case the macro
1739 name starts with a hyphen.
1741 collect[/s] EXPRESSIONS
1742 The tracepoint collect command now takes an optional modifier "/s"
1743 that directs it to dereference pointer-to-character types and
1744 collect the bytes of memory up to a zero byte. The behavior is
1745 similar to what you see when you use the regular print command on a
1746 string. An optional integer following the "/s" sets a bound on the
1747 number of bytes that will be collected.
1750 The trace start command now interprets any supplied arguments as a
1751 note to be recorded with the trace run, with an effect similar to
1752 setting the variable trace-notes.
1755 The trace stop command now interprets any arguments as a note to be
1756 mentioned along with the tstatus report that the trace was stopped
1757 with a command. The effect is similar to setting the variable
1760 * Tracepoints can now be enabled and disabled at any time after a trace
1761 experiment has been started using the standard "enable" and "disable"
1762 commands. It is now possible to start a trace experiment with no enabled
1763 tracepoints; GDB will display a warning, but will allow the experiment to
1764 begin, assuming that tracepoints will be enabled as needed while the trace
1767 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1768 locations with 4-byte instructions, when they were previously
1769 limited to locations with instructions of 5 bytes or longer.
1773 set debug dwarf2-read
1774 show debug dwarf2-read
1775 Turns on or off display of debugging messages related to reading
1776 DWARF debug info. The default is off.
1778 set debug symtab-create
1779 show debug symtab-create
1780 Turns on or off display of debugging messages related to symbol table
1781 creation. The default is off.
1784 show extended-prompt
1785 Set the GDB prompt, and allow escape sequences to be inserted to
1786 display miscellaneous information (see 'help set extended-prompt'
1787 for the list of sequences). This prompt (and any information
1788 accessed through the escape sequences) is updated every time the
1789 prompt is displayed.
1791 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1792 show print entry-values
1793 Set printing of frame argument values at function entry. In some cases
1794 GDB can determine the value of function argument which was passed by the
1795 function caller, even if the value was modified inside the called function.
1797 set debug entry-values
1798 show debug entry-values
1799 Control display of debugging info for determining frame argument values at
1800 function entry and virtual tail call frames.
1802 set basenames-may-differ
1803 show basenames-may-differ
1804 Set whether a source file may have multiple base names.
1805 (A "base name" is the name of a file with the directory part removed.
1806 Example: The base name of "/home/user/hello.c" is "hello.c".)
1807 If set, GDB will canonicalize file names (e.g., expand symlinks)
1808 before comparing them. Canonicalization is an expensive operation,
1809 but it allows the same file be known by more than one base name.
1810 If not set (the default), all source files are assumed to have just
1811 one base name, and gdb will do file name comparisons more efficiently.
1817 Set a user name and notes for the current and any future trace runs.
1818 This is useful for long-running and/or disconnected traces, to
1819 inform others (or yourself) as to who is running the trace, supply
1820 contact information, or otherwise explain what is going on.
1822 set trace-stop-notes
1823 show trace-stop-notes
1824 Set a note attached to the trace run, that is displayed when the
1825 trace has been stopped by a tstop command. This is useful for
1826 instance as an explanation, if you are stopping a trace run that was
1827 started by someone else.
1829 * New remote packets
1833 Dynamically enable a tracepoint in a started trace experiment.
1837 Dynamically disable a tracepoint in a started trace experiment.
1841 Set the user and notes of the trace run.
1845 Query the current status of a tracepoint.
1849 Query the minimum length of instruction at which a fast tracepoint may
1852 * Dcache size (number of lines) and line-size are now runtime-configurable
1853 via "set dcache line" and "set dcache line-size" commands.
1857 Texas Instruments TMS320C6x tic6x-*-*
1861 Renesas RL78 rl78-*-elf
1863 *** Changes in GDB 7.3.1
1865 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1867 *** Changes in GDB 7.3
1869 * GDB has a new command: "thread find [REGEXP]".
1870 It finds the thread id whose name, target id, or thread extra info
1871 matches the given regular expression.
1873 * The "catch syscall" command now works on mips*-linux* targets.
1875 * The -data-disassemble MI command now supports modes 2 and 3 for
1876 dumping the instruction opcodes.
1878 * New command line options
1880 -data-directory DIR Specify DIR as the "data-directory".
1881 This is mostly for testing purposes.
1883 * The "maint set python auto-load on|off" command has been renamed to
1884 "set auto-load-scripts on|off".
1886 * GDB has a new command: "set directories".
1887 It is like the "dir" command except that it replaces the
1888 source path list instead of augmenting it.
1890 * GDB now understands thread names.
1892 On GNU/Linux, "info threads" will display the thread name as set by
1893 prctl or pthread_setname_np.
1895 There is also a new command, "thread name", which can be used to
1896 assign a name internally for GDB to display.
1899 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1900 has been integrated into GDB.
1904 ** The function gdb.Write now accepts an optional keyword 'stream'.
1905 This keyword, when provided, will direct the output to either
1906 stdout, stderr, or GDB's logging output.
1908 ** Parameters can now be be sub-classed in Python, and in particular
1909 you may implement the get_set_doc and get_show_doc functions.
1910 This improves how Parameter set/show documentation is processed
1911 and allows for more dynamic content.
1913 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1914 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1915 have an is_valid method.
1917 ** Breakpoints can now be sub-classed in Python, and in particular
1918 you may implement a 'stop' function that is executed each time
1919 the inferior reaches that breakpoint.
1921 ** New function gdb.lookup_global_symbol looks up a global symbol.
1923 ** GDB values in Python are now callable if the value represents a
1924 function. For example, if 'some_value' represents a function that
1925 takes two integer parameters and returns a value, you can call
1926 that function like so:
1928 result = some_value (10,20)
1930 ** Module gdb.types has been added.
1931 It contains a collection of utilities for working with gdb.Types objects:
1932 get_basic_type, has_field, make_enum_dict.
1934 ** Module gdb.printing has been added.
1935 It contains utilities for writing and registering pretty-printers.
1936 New classes: PrettyPrinter, SubPrettyPrinter,
1937 RegexpCollectionPrettyPrinter.
1938 New function: register_pretty_printer.
1940 ** New commands "info pretty-printers", "enable pretty-printer" and
1941 "disable pretty-printer" have been added.
1943 ** gdb.parameter("directories") is now available.
1945 ** New function gdb.newest_frame returns the newest frame in the
1948 ** The gdb.InferiorThread class has a new "name" attribute. This
1949 holds the thread's name.
1951 ** Python Support for Inferior events.
1952 Python scripts can add observers to be notified of events
1953 occurring in the process being debugged.
1954 The following events are currently supported:
1955 - gdb.events.cont Continue event.
1956 - gdb.events.exited Inferior exited event.
1957 - gdb.events.stop Signal received, and Breakpoint hit events.
1961 ** GDB now puts template parameters in scope when debugging in an
1962 instantiation. For example, if you have:
1964 template<int X> int func (void) { return X; }
1966 then if you step into func<5>, "print X" will show "5". This
1967 feature requires proper debuginfo support from the compiler; it
1968 was added to GCC 4.5.
1970 ** The motion commands "next", "finish", "until", and "advance" now
1971 work better when exceptions are thrown. In particular, GDB will
1972 no longer lose control of the inferior; instead, the GDB will
1973 stop the inferior at the point at which the exception is caught.
1974 This functionality requires a change in the exception handling
1975 code that was introduced in GCC 4.5.
1977 * GDB now follows GCC's rules on accessing volatile objects when
1978 reading or writing target state during expression evaluation.
1979 One notable difference to prior behavior is that "print x = 0"
1980 no longer generates a read of x; the value of the assignment is
1981 now always taken directly from the value being assigned.
1983 * GDB now has some support for using labels in the program's source in
1984 linespecs. For instance, you can use "advance label" to continue
1985 execution to a label.
1987 * GDB now has support for reading and writing a new .gdb_index
1988 section. This section holds a fast index of DWARF debugging
1989 information and can be used to greatly speed up GDB startup and
1990 operation. See the documentation for `save gdb-index' for details.
1992 * The "watch" command now accepts an optional "-location" argument.
1993 When used, this causes GDB to watch the memory referred to by the
1994 expression. Such a watchpoint is never deleted due to it going out
1997 * GDB now supports thread debugging of core dumps on GNU/Linux.
1999 GDB now activates thread debugging using the libthread_db library
2000 when debugging GNU/Linux core dumps, similarly to when debugging
2001 live processes. As a result, when debugging a core dump file, GDB
2002 is now able to display pthread_t ids of threads. For example, "info
2003 threads" shows the same output as when debugging the process when it
2004 was live. In earlier releases, you'd see something like this:
2007 * 1 LWP 6780 main () at main.c:10
2009 While now you see this:
2012 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2014 It is also now possible to inspect TLS variables when debugging core
2017 When debugging a core dump generated on a machine other than the one
2018 used to run GDB, you may need to point GDB at the correct
2019 libthread_db library with the "set libthread-db-search-path"
2020 command. See the user manual for more details on this command.
2022 * When natively debugging programs on PowerPC BookE processors running
2023 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2024 which stop execution of the inferior whenever it executes an instruction
2025 at any address within the specified range. See the "PowerPC Embedded"
2026 section in the user manual for more details.
2028 * New features in the GDB remote stub, GDBserver
2030 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2031 and i686 LynxOS (version 5.x).
2033 ** GDBserver is now supported on Blackfin Linux.
2035 * New native configurations
2037 ia64 HP-UX ia64-*-hpux*
2041 Analog Devices, Inc. Blackfin Processor bfin-*
2043 * Ada task switching is now supported on sparc-elf targets when
2044 debugging a program using the Ravenscar Profile. For more information,
2045 see the "Tasking Support when using the Ravenscar Profile" section
2046 in the GDB user manual.
2048 * Guile support was removed.
2050 * New features in the GNU simulator
2052 ** The --map-info flag lists all known core mappings.
2054 ** CFI flashes may be simulated via the "cfi" device.
2056 *** Changes in GDB 7.2
2058 * Shared library support for remote targets by default
2060 When GDB is configured for a generic, non-OS specific target, like
2061 for example, --target=arm-eabi or one of the many *-*-elf targets,
2062 GDB now queries remote stubs for loaded shared libraries using the
2063 `qXfer:libraries:read' packet. Previously, shared library support
2064 was always disabled for such configurations.
2068 ** Argument Dependent Lookup (ADL)
2070 In C++ ADL lookup directs function search to the namespaces of its
2071 arguments even if the namespace has not been imported.
2081 Here the compiler will search for `foo' in the namespace of 'b'
2082 and find A::foo. GDB now supports this. This construct is commonly
2083 used in the Standard Template Library for operators.
2085 ** Improved User Defined Operator Support
2087 In addition to member operators, GDB now supports lookup of operators
2088 defined in a namespace and imported with a `using' directive, operators
2089 defined in the global scope, operators imported implicitly from an
2090 anonymous namespace, and the ADL operators mentioned in the previous
2092 GDB now also supports proper overload resolution for all the previously
2093 mentioned flavors of operators.
2095 ** static const class members
2097 Printing of static const class members that are initialized in the
2098 class definition has been fixed.
2100 * Windows Thread Information Block access.
2102 On Windows targets, GDB now supports displaying the Windows Thread
2103 Information Block (TIB) structure. This structure is visible either
2104 by using the new command `info w32 thread-information-block' or, by
2105 dereferencing the new convenience variable named `$_tlb', a
2106 thread-specific pointer to the TIB. This feature is also supported
2107 when remote debugging using GDBserver.
2109 * Static tracepoints
2111 Static tracepoints are calls in the user program into a tracing
2112 library. One such library is a port of the LTTng kernel tracer to
2113 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2114 When debugging with GDBserver, GDB now supports combining the GDB
2115 tracepoint machinery with such libraries. For example: the user can
2116 use GDB to probe a static tracepoint marker (a call from the user
2117 program into the tracing library) with the new "strace" command (see
2118 "New commands" below). This creates a "static tracepoint" in the
2119 breakpoint list, that can be manipulated with the same feature set
2120 as fast and regular tracepoints. E.g., collect registers, local and
2121 global variables, collect trace state variables, and define
2122 tracepoint conditions. In addition, the user can collect extra
2123 static tracepoint marker specific data, by collecting the new
2124 $_sdata internal variable. When analyzing the trace buffer, you can
2125 inspect $_sdata like any other variable available to GDB. For more
2126 information, see the "Tracepoints" chapter in GDB user manual. New
2127 remote packets have been defined to support static tracepoints, see
2128 the "New remote packets" section below.
2130 * Better reconstruction of tracepoints after disconnected tracing
2132 GDB will attempt to download the original source form of tracepoint
2133 definitions when starting a trace run, and then will upload these
2134 upon reconnection to the target, resulting in a more accurate
2135 reconstruction of the tracepoints that are in use on the target.
2139 You can now exercise direct control over the ways that GDB can
2140 affect your program. For instance, you can disallow the setting of
2141 breakpoints, so that the program can run continuously (assuming
2142 non-stop mode). In addition, the "observer" variable is available
2143 to switch all of the different controls; in observer mode, GDB
2144 cannot affect the target's behavior at all, which is useful for
2145 tasks like diagnosing live systems in the field.
2147 * The new convenience variable $_thread holds the number of the
2150 * New remote packets
2154 Return the address of the Windows Thread Information Block of a given thread.
2158 In response to several of the tracepoint packets, the target may now
2159 also respond with a number of intermediate `qRelocInsn' request
2160 packets before the final result packet, to have GDB handle
2161 relocating an instruction to execute at a different address. This
2162 is particularly useful for stubs that support fast tracepoints. GDB
2163 reports support for this feature in the qSupported packet.
2167 List static tracepoint markers in the target program.
2171 List static tracepoint markers at a given address in the target
2174 qXfer:statictrace:read
2176 Read the static trace data collected (by a `collect $_sdata'
2177 tracepoint action). The remote stub reports support for this packet
2178 to gdb's qSupported query.
2182 Send the current settings of GDB's permission flags.
2186 Send part of the source (textual) form of a tracepoint definition,
2187 which includes location, conditional, and action list.
2189 * The source command now accepts a -s option to force searching for the
2190 script in the source search path even if the script name specifies
2193 * New features in the GDB remote stub, GDBserver
2195 - GDBserver now support tracepoints (including fast tracepoints, and
2196 static tracepoints). The feature is currently supported by the
2197 i386-linux and amd64-linux builds. See the "Tracepoints support
2198 in gdbserver" section in the manual for more information.
2200 GDBserver JIT compiles the tracepoint's conditional agent
2201 expression bytecode into native code whenever possible for low
2202 overhead dynamic tracepoints conditionals. For such tracepoints,
2203 an expression that examines program state is evaluated when the
2204 tracepoint is reached, in order to determine whether to capture
2205 trace data. If the condition is simple and false, processing the
2206 tracepoint finishes very quickly and no data is gathered.
2208 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2209 for static tracepoints support.
2211 - GDBserver now supports x86_64 Windows 64-bit debugging.
2213 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2214 it understands register description.
2216 * The --batch flag now disables pagination and queries.
2218 * X86 general purpose registers
2220 GDB now supports reading/writing byte, word and double-word x86
2221 general purpose registers directly. This means you can use, say,
2222 $ah or $ax to refer, respectively, to the byte register AH and
2223 16-bit word register AX that are actually portions of the 32-bit
2224 register EAX or 64-bit register RAX.
2226 * The `commands' command now accepts a range of breakpoints to modify.
2227 A plain `commands' following a command that creates multiple
2228 breakpoints affects all the breakpoints set by that command. This
2229 applies to breakpoints set by `rbreak', and also applies when a
2230 single `break' command creates multiple breakpoints (e.g.,
2231 breakpoints on overloaded c++ functions).
2233 * The `rbreak' command now accepts a filename specification as part of
2234 its argument, limiting the functions selected by the regex to those
2235 in the specified file.
2237 * Support for remote debugging Windows and SymbianOS shared libraries
2238 from Unix hosts has been improved. Non Windows GDB builds now can
2239 understand target reported file names that follow MS-DOS based file
2240 system semantics, such as file names that include drive letters and
2241 use the backslash character as directory separator. This makes it
2242 possible to transparently use the "set sysroot" and "set
2243 solib-search-path" on Unix hosts to point as host copies of the
2244 target's shared libraries. See the new command "set
2245 target-file-system-kind" described below, and the "Commands to
2246 specify files" section in the user manual for more information.
2250 eval template, expressions...
2251 Convert the values of one or more expressions under the control
2252 of the string template to a command line, and call it.
2254 set target-file-system-kind unix|dos-based|auto
2255 show target-file-system-kind
2256 Set or show the assumed file system kind for target reported file
2259 save breakpoints <filename>
2260 Save all current breakpoint definitions to a file suitable for use
2261 in a later debugging session. To read the saved breakpoint
2262 definitions, use the `source' command.
2264 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2267 info static-tracepoint-markers
2268 Display information about static tracepoint markers in the target.
2270 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2271 Define a static tracepoint by probing a marker at the given
2272 function, line, address, or marker ID.
2276 Enable and disable observer mode.
2278 set may-write-registers on|off
2279 set may-write-memory on|off
2280 set may-insert-breakpoints on|off
2281 set may-insert-tracepoints on|off
2282 set may-insert-fast-tracepoints on|off
2283 set may-interrupt on|off
2284 Set individual permissions for GDB effects on the target. Note that
2285 some of these settings can have undesirable or surprising
2286 consequences, particularly when changed in the middle of a session.
2287 For instance, disabling the writing of memory can prevent
2288 breakpoints from being inserted, cause single-stepping to fail, or
2289 even crash your program, if you disable after breakpoints have been
2290 inserted. However, GDB should not crash.
2292 set record memory-query on|off
2293 show record memory-query
2294 Control whether to stop the inferior if memory changes caused
2295 by an instruction cannot be recorded.
2300 The disassemble command now supports "start,+length" form of two arguments.
2304 ** GDB now provides a new directory location, called the python directory,
2305 where Python scripts written for GDB can be installed. The location
2306 of that directory is <data-directory>/python, where <data-directory>
2307 is the GDB data directory. For more details, see section `Scripting
2308 GDB using Python' in the manual.
2310 ** The GDB Python API now has access to breakpoints, symbols, symbol
2311 tables, program spaces, inferiors, threads and frame's code blocks.
2312 Additionally, GDB Parameters can now be created from the API, and
2313 manipulated via set/show in the CLI.
2315 ** New functions gdb.target_charset, gdb.target_wide_charset,
2316 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2318 ** New exception gdb.GdbError.
2320 ** Pretty-printers are now also looked up in the current program space.
2322 ** Pretty-printers can now be individually enabled and disabled.
2324 ** GDB now looks for names of Python scripts to auto-load in a
2325 special section named `.debug_gdb_scripts', in addition to looking
2326 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2328 * Tracepoint actions were unified with breakpoint commands. In particular,
2329 there are no longer differences in "info break" output for breakpoints and
2330 tracepoints and the "commands" command can be used for both tracepoints and
2331 regular breakpoints.
2335 ARM Symbian arm*-*-symbianelf*
2337 * D language support.
2338 GDB now supports debugging programs written in the D programming
2341 * GDB now supports the extended ptrace interface for PowerPC which is
2342 available since Linux kernel version 2.6.34. This automatically enables
2343 any hardware breakpoints and additional hardware watchpoints available in
2344 the processor. The old ptrace interface exposes just one hardware
2345 watchpoint and no hardware breakpoints.
2347 * GDB is now able to use the Data Value Compare (DVC) register available on
2348 embedded PowerPC processors to implement in hardware simple watchpoint
2349 conditions of the form:
2351 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2353 This works in native GDB running on Linux kernels with the extended ptrace
2354 interface mentioned above.
2356 *** Changes in GDB 7.1
2360 ** Namespace Support
2362 GDB now supports importing of namespaces in C++. This enables the
2363 user to inspect variables from imported namespaces. Support for
2364 namepace aliasing has also been added. So, if a namespace is
2365 aliased in the current scope (e.g. namepace C=A; ) the user can
2366 print variables using the alias (e.g. (gdb) print C::x).
2370 All known bugs relating to the printing of virtual base class were
2371 fixed. It is now possible to call overloaded static methods using a
2376 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2377 and reinterpret_cast<> are now handled by the C++ expression parser.
2381 Xilinx MicroBlaze microblaze-*-*
2386 Xilinx MicroBlaze microblaze
2389 * Multi-program debugging.
2391 GDB now has support for multi-program (a.k.a. multi-executable or
2392 multi-exec) debugging. This allows for debugging multiple inferiors
2393 simultaneously each running a different program under the same GDB
2394 session. See "Debugging Multiple Inferiors and Programs" in the
2395 manual for more information. This implied some user visible changes
2396 in the multi-inferior support. For example, "info inferiors" now
2397 lists inferiors that are not running yet or that have exited
2398 already. See also "New commands" and "New options" below.
2400 * New tracing features
2402 GDB's tracepoint facility now includes several new features:
2404 ** Trace state variables
2406 GDB tracepoints now include support for trace state variables, which
2407 are variables managed by the target agent during a tracing
2408 experiment. They are useful for tracepoints that trigger each
2409 other, so for instance one tracepoint can count hits in a variable,
2410 and then a second tracepoint has a condition that is true when the
2411 count reaches a particular value. Trace state variables share the
2412 $-syntax of GDB convenience variables, and can appear in both
2413 tracepoint actions and condition expressions. Use the "tvariable"
2414 command to create, and "info tvariables" to view; see "Trace State
2415 Variables" in the manual for more detail.
2419 GDB now includes an option for defining fast tracepoints, which
2420 targets may implement more efficiently, such as by installing a jump
2421 into the target agent rather than a trap instruction. The resulting
2422 speedup can be by two orders of magnitude or more, although the
2423 tradeoff is that some program locations on some target architectures
2424 might not allow fast tracepoint installation, for instance if the
2425 instruction to be replaced is shorter than the jump. To request a
2426 fast tracepoint, use the "ftrace" command, with syntax identical to
2427 the regular trace command.
2429 ** Disconnected tracing
2431 It is now possible to detach GDB from the target while it is running
2432 a trace experiment, then reconnect later to see how the experiment
2433 is going. In addition, a new variable disconnected-tracing lets you
2434 tell the target agent whether to continue running a trace if the
2435 connection is lost unexpectedly.
2439 GDB now has the ability to save the trace buffer into a file, and
2440 then use that file as a target, similarly to you can do with
2441 corefiles. You can select trace frames, print data that was
2442 collected in them, and use tstatus to display the state of the
2443 tracing run at the moment that it was saved. To create a trace
2444 file, use "tsave <filename>", and to use it, do "target tfile
2447 ** Circular trace buffer
2449 You can ask the target agent to handle the trace buffer as a
2450 circular buffer, discarding the oldest trace frames to make room for
2451 newer ones, by setting circular-trace-buffer to on. This feature may
2452 not be available for all target agents.
2457 The disassemble command, when invoked with two arguments, now requires
2458 the arguments to be comma-separated.
2461 The info variables command now displays variable definitions. Files
2462 which only declare a variable are not shown.
2465 The source command is now capable of sourcing Python scripts.
2466 This feature is dependent on the debugger being build with Python
2469 Related to this enhancement is also the introduction of a new command
2470 "set script-extension" (see below).
2472 * New commands (for set/show, see "New options" below)
2474 record save [<FILENAME>]
2475 Save a file (in core file format) containing the process record
2476 execution log for replay debugging at a later time.
2478 record restore <FILENAME>
2479 Restore the process record execution log that was saved at an
2480 earlier time, for replay debugging.
2482 add-inferior [-copies <N>] [-exec <FILENAME>]
2485 clone-inferior [-copies <N>] [ID]
2486 Make a new inferior ready to execute the same program another
2487 inferior has loaded.
2492 maint info program-spaces
2493 List the program spaces loaded into GDB.
2495 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2496 show remote interrupt-sequence
2497 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2498 as the sequence to the remote target in order to interrupt the execution.
2499 Ctrl-C is a default. Some system prefers BREAK which is high level of
2500 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2501 Magic SysRq g. It is BREAK signal and character 'g'.
2503 set remote interrupt-on-connect [on | off]
2504 show remote interrupt-on-connect
2505 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2506 remote target when gdb connects to it. This is needed when you debug
2509 set remotebreak [on | off]
2511 Deprecated. Use "set/show remote interrupt-sequence" instead.
2513 tvariable $NAME [ = EXP ]
2514 Create or modify a trace state variable.
2517 List trace state variables and their values.
2519 delete tvariable $NAME ...
2520 Delete one or more trace state variables.
2523 Evaluate the given expressions without collecting anything into the
2524 trace buffer. (Valid in tracepoint actions only.)
2526 ftrace FN / FILE:LINE / *ADDR
2527 Define a fast tracepoint at the given function, line, or address.
2529 * New expression syntax
2531 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2532 GDB now parses 0b101010 identically with 42.
2536 set follow-exec-mode new|same
2537 show follow-exec-mode
2538 Control whether GDB reuses the same inferior across an exec call or
2539 creates a new one. This is useful to be able to restart the old
2540 executable after the inferior having done an exec call.
2542 set default-collect EXPR, ...
2543 show default-collect
2544 Define a list of expressions to be collected at each tracepoint.
2545 This is a useful way to ensure essential items are not overlooked,
2546 such as registers or a critical global variable.
2548 set disconnected-tracing
2549 show disconnected-tracing
2550 If set to 1, the target is instructed to continue tracing if it
2551 loses its connection to GDB. If 0, the target is to stop tracing
2554 set circular-trace-buffer
2555 show circular-trace-buffer
2556 If set to on, the target is instructed to use a circular trace buffer
2557 and discard the oldest trace frames instead of stopping the trace due
2558 to a full trace buffer. If set to off, the trace stops when the buffer
2559 fills up. Some targets may not support this.
2561 set script-extension off|soft|strict
2562 show script-extension
2563 If set to "off", the debugger does not perform any script language
2564 recognition, and all sourced files are assumed to be GDB scripts.
2565 If set to "soft" (the default), files are sourced according to
2566 filename extension, falling back to GDB scripts if the first
2568 If set to "strict", files are sourced according to filename extension.
2570 set ada trust-PAD-over-XVS on|off
2571 show ada trust-PAD-over-XVS
2572 If off, activate a workaround against a bug in the debugging information
2573 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2574 the GCC sources for more information about the GNAT encoding and
2575 PAD types in particular). It is always safe to set this option to
2576 off, but this introduces a slight performance penalty. The default
2579 * Python API Improvements
2581 ** GDB provides the new class gdb.LazyString. This is useful in
2582 some pretty-printing cases. The new method gdb.Value.lazy_string
2583 provides a simple way to create objects of this type.
2585 ** The fields returned by gdb.Type.fields now have an
2586 `is_base_class' attribute.
2588 ** The new method gdb.Type.range returns the range of an array type.
2590 ** The new method gdb.parse_and_eval can be used to parse and
2591 evaluate an expression.
2593 * New remote packets
2596 Define a trace state variable.
2599 Get the current value of a trace state variable.
2602 Set desired tracing behavior upon disconnection.
2605 Set the trace buffer to be linear or circular.
2608 Get data about the tracepoints currently in use.
2612 Process record now works correctly with hardware watchpoints.
2614 Multiple bug fixes have been made to the mips-irix port, making it
2615 much more reliable. In particular:
2616 - Debugging threaded applications is now possible again. Previously,
2617 GDB would hang while starting the program, or while waiting for
2618 the program to stop at a breakpoint.
2619 - Attaching to a running process no longer hangs.
2620 - An error occurring while loading a core file has been fixed.
2621 - Changing the value of the PC register now works again. This fixes
2622 problems observed when using the "jump" command, or when calling
2623 a function from GDB, or even when assigning a new value to $pc.
2624 - With the "finish" and "return" commands, the return value for functions
2625 returning a small array is now correctly printed.
2626 - It is now possible to break on shared library code which gets executed
2627 during a shared library init phase (code executed while executing
2628 their .init section). Previously, the breakpoint would have no effect.
2629 - GDB is now able to backtrace through the signal handler for
2630 non-threaded programs.
2632 PIE (Position Independent Executable) programs debugging is now supported.
2633 This includes debugging execution of PIC (Position Independent Code) shared
2634 libraries although for that, it should be possible to run such libraries as an
2637 *** Changes in GDB 7.0
2639 * GDB now has an interface for JIT compilation. Applications that
2640 dynamically generate code can create symbol files in memory and register
2641 them with GDB. For users, the feature should work transparently, and
2642 for JIT developers, the interface is documented in the GDB manual in the
2643 "JIT Compilation Interface" chapter.
2645 * Tracepoints may now be conditional. The syntax is as for
2646 breakpoints; either an "if" clause appended to the "trace" command,
2647 or the "condition" command is available. GDB sends the condition to
2648 the target for evaluation using the same bytecode format as is used
2649 for tracepoint actions.
2651 * The disassemble command now supports: an optional /r modifier, print the
2652 raw instructions in hex as well as in symbolic form, and an optional /m
2653 modifier to print mixed source+assembly.
2655 * Process record and replay
2657 In a architecture environment that supports ``process record and
2658 replay'', ``process record and replay'' target can record a log of
2659 the process execution, and replay it with both forward and reverse
2662 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2663 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2664 set execution-direction {forward|reverse}, for targets that support
2667 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2668 feature is available with a native GDB running on kernel version
2671 * GDB now has support for multi-byte and wide character sets on the
2672 target. Strings whose character type is wchar_t, char16_t, or
2673 char32_t are now correctly printed. GDB supports wide- and unicode-
2674 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2675 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2676 `printf'. This feature requires iconv to work properly; if your
2677 system does not have a working iconv, GDB can use GNU libiconv. See
2678 the installation instructions for more information.
2680 * GDB now supports automatic retrieval of shared library files from
2681 remote targets. To use this feature, specify a system root that begins
2682 with the `remote:' prefix, either via the `set sysroot' command or via
2683 the `--with-sysroot' configure-time option.
2685 * "info sharedlibrary" now takes an optional regex of libraries to show,
2686 and it now reports if a shared library has no debugging information.
2688 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2689 now complete on file names.
2691 * When completing in expressions, gdb will attempt to limit
2692 completions to allowable structure or union fields, where appropriate.
2693 For instance, consider:
2695 # struct example { int f1; double f2; };
2696 # struct example variable;
2699 If the user types TAB at the end of this command line, the available
2700 completions will be "f1" and "f2".
2702 * Inlined functions are now supported. They show up in backtraces, and
2703 the "step", "next", and "finish" commands handle them automatically.
2705 * GDB now supports the token-splicing (##) and stringification (#)
2706 operators when expanding macros. It also supports variable-arity
2709 * GDB now supports inspecting extra signal information, exported by
2710 the new $_siginfo convenience variable. The feature is currently
2711 implemented on linux ARM, i386 and amd64.
2713 * GDB can now display the VFP floating point registers and NEON vector
2714 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2715 can provide these registers (requires Linux 2.6.30 or later). Remote
2716 and simulator targets may also provide them.
2718 * New remote packets
2721 Search memory for a sequence of bytes.
2724 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2725 operation over reliable transport links. Use of this packet is
2726 controlled by the `set remote noack-packet' command.
2729 Kill the process with the specified process ID. Use this in preference
2730 to `k' when multiprocess protocol extensions are supported.
2733 Obtains additional operating system information
2737 Read or write additional signal information.
2739 * Removed remote protocol undocumented extension
2741 An undocumented extension to the remote protocol's `S' stop reply
2742 packet that permited the stub to pass a process id was removed.
2743 Remote servers should use the `T' stop reply packet instead.
2745 * GDB now supports multiple function calling conventions according to the
2746 DWARF-2 DW_AT_calling_convention function attribute.
2748 * The SH target utilizes the aforementioned change to distinguish between gcc
2749 and Renesas calling convention. It also adds the new CLI commands
2750 `set/show sh calling-convention'.
2752 * GDB can now read compressed debug sections, as produced by GNU gold
2753 with the --compress-debug-sections=zlib flag.
2755 * 64-bit core files are now supported on AIX.
2757 * Thread switching is now supported on Tru64.
2759 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2760 which will be allocated using malloc later in program execution.
2762 * The qXfer:libraries:read remote procotol packet now allows passing a
2763 list of section offsets.
2765 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2766 conditions handling signals delivered during attach or thread creation
2767 have also been fixed.
2769 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2770 From the user's standpoint, all unqualified instances of True and False
2771 are treated as the standard definitions, regardless of context.
2773 * GDB now parses C++ symbol and type names more flexibly. For
2776 template<typename T> class C { };
2779 GDB will now correctly handle all of:
2781 ptype C<char const *>
2782 ptype C<char const*>
2783 ptype C<const char *>
2784 ptype C<const char*>
2786 * New features in the GDB remote stub, gdbserver
2788 - The "--wrapper" command-line argument tells gdbserver to use a
2789 wrapper program to launch programs for debugging.
2791 - On PowerPC and S/390 targets, it is now possible to use a single
2792 gdbserver executable to debug both 32-bit and 64-bit programs.
2793 (This requires gdbserver itself to be built as a 64-bit executable.)
2795 - gdbserver uses the new noack protocol mode for TCP connections to
2796 reduce communications latency, if also supported and enabled in GDB.
2798 - Support for the sparc64-linux-gnu target is now included in
2801 - The amd64-linux build of gdbserver now supports debugging both
2802 32-bit and 64-bit programs.
2804 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2805 now support hardware watchpoints, and will use them automatically
2810 GDB now has support for scripting using Python. Whether this is
2811 available is determined at configure time.
2813 New GDB commands can now be written in Python.
2815 * Ada tasking support
2817 Ada tasks can now be inspected in GDB. The following commands have
2821 Print the list of Ada tasks.
2823 Print detailed information about task number N.
2825 Print the task number of the current task.
2827 Switch the context of debugging to task number N.
2829 * Support for user-defined prefixed commands. The "define" command can
2830 add new commands to existing prefixes, e.g. "target".
2832 * Multi-inferior, multi-process debugging.
2834 GDB now has generalized support for multi-inferior debugging. See
2835 "Debugging Multiple Inferiors" in the manual for more information.
2836 Although availability still depends on target support, the command
2837 set is more uniform now. The GNU/Linux specific multi-forks support
2838 has been migrated to this new framework. This implied some user
2839 visible changes; see "New commands" and also "Removed commands"
2842 * Target descriptions can now describe the target OS ABI. See the
2843 "Target Description Format" section in the user manual for more
2846 * Target descriptions can now describe "compatible" architectures
2847 to indicate that the target can execute applications for a different
2848 architecture in addition to those for the main target architecture.
2849 See the "Target Description Format" section in the user manual for
2852 * Multi-architecture debugging.
2854 GDB now includes general supports for debugging applications on
2855 hybrid systems that use more than one single processor architecture
2856 at the same time. Each such hybrid architecture still requires
2857 specific support to be added. The only hybrid architecture supported
2858 in this version of GDB is the Cell Broadband Engine.
2860 * GDB now supports integrated debugging of Cell/B.E. applications that
2861 use both the PPU and SPU architectures. To enable support for hybrid
2862 Cell/B.E. debugging, you need to configure GDB to support both the
2863 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2864 --enable-targets configure option.
2866 * Non-stop mode debugging.
2868 For some targets, GDB now supports an optional mode of operation in
2869 which you can examine stopped threads while other threads continue
2870 to execute freely. This is referred to as non-stop mode, with the
2871 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2872 section in the user manual for more information.
2874 To be able to support remote non-stop debugging, a remote stub needs
2875 to implement the non-stop mode remote protocol extensions, as
2876 described in the "Remote Non-Stop" section of the user manual. The
2877 GDB remote stub, gdbserver, has been adjusted to support these
2878 extensions on linux targets.
2880 * New commands (for set/show, see "New options" below)
2882 catch syscall [NAME(S) | NUMBER(S)]
2883 Catch system calls. Arguments, which should be names of system
2884 calls or their numbers, mean catch only those syscalls. Without
2885 arguments, every syscall will be caught. When the inferior issues
2886 any of the specified syscalls, GDB will stop and announce the system
2887 call, both when it is called and when its call returns. This
2888 feature is currently available with a native GDB running on the
2889 Linux Kernel, under the following architectures: x86, x86_64,
2890 PowerPC and PowerPC64.
2892 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2894 Search memory for a sequence of bytes.
2896 maint set python print-stack
2897 maint show python print-stack
2898 Show a stack trace when an error is encountered in a Python script.
2901 Invoke CODE by passing it to the Python interpreter.
2906 These allow macros to be defined, undefined, and listed
2910 Show operating system information about processes.
2913 List the inferiors currently under GDB's control.
2916 Switch focus to inferior number NUM.
2919 Detach from inferior number NUM.
2922 Kill inferior number NUM.
2926 set spu stop-on-load
2927 show spu stop-on-load
2928 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2930 set spu auto-flush-cache
2931 show spu auto-flush-cache
2932 Control whether to automatically flush the software-managed cache
2933 during Cell/B.E. debugging.
2935 set sh calling-convention
2936 show sh calling-convention
2937 Control the calling convention used when calling SH target functions.
2940 show debug timestamp
2941 Control display of timestamps with GDB debugging output.
2943 set disassemble-next-line
2944 show disassemble-next-line
2945 Control display of disassembled source lines or instructions when
2948 set remote noack-packet
2949 show remote noack-packet
2950 Set/show the use of remote protocol QStartNoAckMode packet. See above
2951 under "New remote packets."
2953 set remote query-attached-packet
2954 show remote query-attached-packet
2955 Control use of remote protocol `qAttached' (query-attached) packet.
2957 set remote read-siginfo-object
2958 show remote read-siginfo-object
2959 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2962 set remote write-siginfo-object
2963 show remote write-siginfo-object
2964 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2967 set remote reverse-continue
2968 show remote reverse-continue
2969 Control use of remote protocol 'bc' (reverse-continue) packet.
2971 set remote reverse-step
2972 show remote reverse-step
2973 Control use of remote protocol 'bs' (reverse-step) packet.
2975 set displaced-stepping
2976 show displaced-stepping
2977 Control displaced stepping mode. Displaced stepping is a way to
2978 single-step over breakpoints without removing them from the debuggee.
2979 Also known as "out-of-line single-stepping".
2982 show debug displaced
2983 Control display of debugging info for displaced stepping.
2985 maint set internal-error
2986 maint show internal-error
2987 Control what GDB does when an internal error is detected.
2989 maint set internal-warning
2990 maint show internal-warning
2991 Control what GDB does when an internal warning is detected.
2996 Use a wrapper program to launch programs for debugging.
2998 set multiple-symbols (all|ask|cancel)
2999 show multiple-symbols
3000 The value of this variable can be changed to adjust the debugger behavior
3001 when an expression or a breakpoint location contains an ambiguous symbol
3002 name (an overloaded function name, for instance).
3004 set breakpoint always-inserted
3005 show breakpoint always-inserted
3006 Keep breakpoints always inserted in the target, as opposed to inserting
3007 them when resuming the target, and removing them when the target stops.
3008 This option can improve debugger performance on slow remote targets.
3010 set arm fallback-mode (arm|thumb|auto)
3011 show arm fallback-mode
3012 set arm force-mode (arm|thumb|auto)
3014 These commands control how ARM GDB determines whether instructions
3015 are ARM or Thumb. The default for both settings is auto, which uses
3016 the current CPSR value for instructions without symbols; previous
3017 versions of GDB behaved as if "set arm fallback-mode arm".
3019 set disable-randomization
3020 show disable-randomization
3021 Standalone programs run with the virtual address space randomization enabled
3022 by default on some platforms. This option keeps the addresses stable across
3023 multiple debugging sessions.
3027 Control whether other threads are stopped or not when some thread hits
3032 Requests that asynchronous execution is enabled in the target, if available.
3033 In this case, it's possible to resume target in the background, and interact
3034 with GDB while the target is running. "show target-async" displays the
3035 current state of asynchronous execution of the target.
3037 set target-wide-charset
3038 show target-wide-charset
3039 The target-wide-charset is the name of the character set that GDB
3040 uses when printing characters whose type is wchar_t.
3042 set tcp auto-retry (on|off)
3044 set tcp connect-timeout
3045 show tcp connect-timeout
3046 These commands allow GDB to retry failed TCP connections to a remote stub
3047 with a specified timeout period; this is useful if the stub is launched
3048 in parallel with GDB but may not be ready to accept connections immediately.
3050 set libthread-db-search-path
3051 show libthread-db-search-path
3052 Control list of directories which GDB will search for appropriate
3055 set schedule-multiple (on|off)
3056 show schedule-multiple
3057 Allow GDB to resume all threads of all processes or only threads of
3058 the current process.
3062 Use more aggressive caching for accesses to the stack. This improves
3063 performance of remote debugging (particularly backtraces) without
3064 affecting correctness.
3066 set interactive-mode (on|off|auto)
3067 show interactive-mode
3068 Control whether GDB runs in interactive mode (on) or not (off).
3069 When in interactive mode, GDB waits for the user to answer all
3070 queries. Otherwise, GDB does not wait and assumes the default
3071 answer. When set to auto (the default), GDB determines which
3072 mode to use based on the stdin settings.
3077 For program forks, this is replaced by the new more generic `info
3078 inferiors' command. To list checkpoints, you can still use the
3079 `info checkpoints' command, which was an alias for the `info forks'
3083 Replaced by the new `inferior' command. To switch between
3084 checkpoints, you can still use the `restart' command, which was an
3085 alias for the `fork' command.
3088 This is removed, since some targets don't have a notion of
3089 processes. To switch between processes, you can still use the
3090 `inferior' command using GDB's own inferior number.
3093 For program forks, this is replaced by the new more generic `kill
3094 inferior' command. To delete a checkpoint, you can still use the
3095 `delete checkpoint' command, which was an alias for the `delete
3099 For program forks, this is replaced by the new more generic `detach
3100 inferior' command. To detach a checkpoint, you can still use the
3101 `detach checkpoint' command, which was an alias for the `detach
3104 * New native configurations
3106 x86/x86_64 Darwin i[34567]86-*-darwin*
3108 x86_64 MinGW x86_64-*-mingw*
3112 Lattice Mico32 lm32-*
3113 x86 DICOS i[34567]86-*-dicos*
3114 x86_64 DICOS x86_64-*-dicos*
3117 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3118 (mingw32ce) debugging.
3124 These commands were actually not implemented on any target.
3126 *** Changes in GDB 6.8
3128 * New native configurations
3130 NetBSD/hppa hppa*-*netbsd*
3131 Xtensa GNU/Linux xtensa*-*-linux*
3135 NetBSD/hppa hppa*-*-netbsd*
3136 Xtensa GNU/Lunux xtensa*-*-linux*
3138 * Change in command line behavior -- corefiles vs. process ids.
3140 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3141 attaching to process NUMBER fails, GDB no longer attempts to open a
3142 core file named NUMBER. Attaching to a program using the -c option
3143 is no longer supported. Instead, use the '-p' or '--pid' options.
3145 * GDB can now be built as a native debugger for debugging Windows x86
3146 (mingw32) Portable Executable (PE) programs.
3148 * Pending breakpoints no longer change their number when their address
3151 * GDB now supports breakpoints with multiple locations,
3152 including breakpoints on C++ constructors, inside C++ templates,
3153 and in inlined functions.
3155 * GDB's ability to debug optimized code has been improved. GDB more
3156 accurately identifies function bodies and lexical blocks that occupy
3157 more than one contiguous range of addresses.
3159 * Target descriptions can now describe registers for PowerPC.
3161 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3162 registers on PowerPC targets.
3164 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3165 targets even when the libthread_db library is not available.
3167 * The GDB remote stub, gdbserver, now supports the new file transfer
3168 commands (remote put, remote get, and remote delete).
3170 * The GDB remote stub, gdbserver, now supports run and attach in
3171 extended-remote mode.
3173 * hppa*64*-*-hpux11* target broken
3174 The debugger is unable to start a program and fails with the following
3175 error: "Error trying to get information about dynamic linker".
3176 The gdb-6.7 release is also affected.
3178 * GDB now supports the --enable-targets= configure option to allow
3179 building a single GDB executable that supports multiple remote
3180 target architectures.
3182 * GDB now supports debugging C and C++ programs which use the
3183 Decimal Floating Point extension. In addition, the PowerPC target
3184 now has a set of pseudo-registers to inspect decimal float values
3185 stored in two consecutive float registers.
3187 * The -break-insert MI command can optionally create pending
3190 * Improved support for debugging Ada
3191 Many improvements to the Ada language support have been made. These
3193 - Better support for Ada2005 interface types
3194 - Improved handling of arrays and slices in general
3195 - Better support for Taft-amendment types
3196 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3198 - Improved command completion in Ada
3201 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3206 set print frame-arguments (all|scalars|none)
3207 show print frame-arguments
3208 The value of this variable can be changed to control which argument
3209 values should be printed by the debugger when displaying a frame.
3214 Transfer files to and from a remote target, and delete remote files.
3221 Transfer files to and from a remote target, and delete remote files.
3223 * New remote packets
3230 Open, close, read, write, and delete files on the remote system.
3233 Attach to an existing process on the remote system, in extended-remote
3237 Run a new process on the remote system, in extended-remote mode.
3239 *** Changes in GDB 6.7
3241 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3242 bfd, libiberty and opcodes, as revealed by static analysis donated by
3243 Coverity, Inc. (http://scan.coverity.com).
3245 * When looking up multiply-defined global symbols, GDB will now prefer the
3246 symbol definition in the current shared library if it was built using the
3247 -Bsymbolic linker option.
3249 * When the Text User Interface (TUI) is not configured, GDB will now
3250 recognize the -tui command-line option and print a message that the TUI
3253 * The GDB remote stub, gdbserver, now has lower overhead for high
3254 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3256 * GDB for MIPS targets now autodetects whether a remote target provides
3257 32-bit or 64-bit register values.
3259 * Support for C++ member pointers has been improved.
3261 * GDB now understands XML target descriptions, which specify the
3262 target's overall architecture. GDB can read a description from
3263 a local file or over the remote serial protocol.
3265 * Vectors of single-byte data use a new integer type which is not
3266 automatically displayed as character or string data.
3268 * The /s format now works with the print command. It displays
3269 arrays of single-byte integers and pointers to single-byte integers
3272 * Target descriptions can now describe target-specific registers,
3273 for architectures which have implemented the support (currently
3274 only ARM, M68K, and MIPS).
3276 * GDB and the GDB remote stub, gdbserver, now support the XScale
3279 * The GDB remote stub, gdbserver, has been updated to support
3280 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3281 has been rewritten to use the standard GDB remote protocol.
3283 * GDB can now step into C++ functions which are called through thunks.
3285 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3287 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3288 layout. It also supports a TextSeg= and DataSeg= response when only
3289 segment base addresses (rather than offsets) are available.
3291 * The /i format now outputs any trailing branch delay slot instructions
3292 immediately following the last instruction within the count specified.
3294 * The GDB remote protocol "T" stop reply packet now supports a
3295 "library" response. Combined with the new "qXfer:libraries:read"
3296 packet, this response allows GDB to debug shared libraries on targets
3297 where the operating system manages the list of loaded libraries (e.g.
3298 Windows and SymbianOS).
3300 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3301 (DLLs) on Windows and Windows CE targets.
3303 * GDB now supports a faster verification that a .debug file matches its binary
3304 according to its build-id signature, if the signature is present.
3310 Enable or disable hardware flow control (RTS/CTS) on the serial port
3311 when debugging using remote targets.
3313 set mem inaccessible-by-default
3314 show mem inaccessible-by-default
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 prevents GDB from accessing memory outside the memory map. This
3318 is useful for targets with memory mapped registers or which react
3319 badly to accesses of unmapped address space.
3321 set breakpoint auto-hw
3322 show breakpoint auto-hw
3323 If the target supplies a memory map, for instance via the remote
3324 protocol's "qXfer:memory-map:read" packet, setting this variable
3325 lets GDB use hardware breakpoints automatically for memory regions
3326 where it can not use software breakpoints. This covers both the
3327 "break" command and internal breakpoints used for other commands
3328 including "next" and "finish".
3331 catch exception unhandled
3332 Stop the program execution when Ada exceptions are raised.
3335 Stop the program execution when an Ada assertion failed.
3339 Set an alternate system root for target files. This is a more
3340 general version of "set solib-absolute-prefix", which is now
3341 an alias to "set sysroot".
3344 Provide extended SPU facility status information. This set of
3345 commands is available only when debugging the Cell/B.E. SPU
3348 * New native configurations
3350 OpenBSD/sh sh*-*openbsd*
3353 unset tdesc filename
3355 Use the specified local file as an XML target description, and do
3356 not query the target for its built-in description.
3360 OpenBSD/sh sh*-*-openbsd*
3361 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3362 Toshiba Media Processor mep-elf
3364 * New remote packets
3367 Ignore the specified signals; pass them directly to the debugged program
3368 without stopping other threads or reporting them to GDB.
3370 qXfer:features:read:
3371 Read an XML target description from the target, which describes its
3376 Read or write contents of an spufs file on the target system. These
3377 packets are available only on the Cell/B.E. SPU architecture.
3379 qXfer:libraries:read:
3380 Report the loaded shared libraries. Combined with new "T" packet
3381 response, this packet allows GDB to debug shared libraries on
3382 targets where the operating system manages the list of loaded
3383 libraries (e.g. Windows and SymbianOS).
3387 Support for these obsolete configurations has been removed.
3395 i[34567]86-*-lynxos*
3396 i[34567]86-*-netware*
3397 i[34567]86-*-sco3.2v5*
3398 i[34567]86-*-sco3.2v4*
3400 i[34567]86-*-sysv4.2*
3403 i[34567]86-*-unixware2*
3404 i[34567]86-*-unixware*
3413 * Other removed features
3420 Various m68k-only ROM monitors.
3427 Various Renesas ROM monitors and debugging interfaces for SH and
3432 Support for a Macraigor serial interface to on-chip debugging.
3433 GDB does not directly support the newer parallel or USB
3438 A debug information format. The predecessor to DWARF 2 and
3439 DWARF 3, which are still supported.
3441 Support for the HP aCC compiler on HP-UX/PA-RISC
3443 SOM-encapsulated symbolic debugging information, automatic
3444 invocation of pxdb, and the aCC custom C++ ABI. This does not
3445 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3446 with aCC can still be debugged on an assembly level.
3448 MIPS ".pdr" sections
3450 A MIPS-specific format used to describe stack frame layout
3451 in debugging information.
3455 GDB could work with an older version of Guile to debug
3456 the interpreter and Scheme programs running in it.
3458 set mips stack-arg-size
3459 set mips saved-gpreg-size
3461 Use "set mips abi" to control parameter passing for MIPS.
3463 *** Changes in GDB 6.6
3468 Cell Broadband Engine SPU spu-elf
3470 * GDB can now be configured as a cross-debugger targeting native Windows
3471 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3472 running on a Windows system over TCP/IP to debug Windows programs.
3474 * The GDB remote stub, gdbserver, has been updated to support Windows and
3475 Cygwin debugging. Both single-threaded and multi-threaded programs are
3478 * The "set trust-readonly-sections" command works again. This command was
3479 broken in GDB 6.3, 6.4, and 6.5.
3481 * The "load" command now supports writing to flash memory, if the remote
3482 stub provides the required support.
3484 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3485 longer requires symbolic debug information (e.g. DWARF-2).
3490 unset substitute-path
3491 show substitute-path
3492 Manage a list of substitution rules that GDB uses to rewrite the name
3493 of the directories where the sources are located. This can be useful
3494 for instance when the sources were moved to a different location
3495 between compilation and debugging.
3499 Print each CLI command as it is executed. Each command is prefixed with
3500 a number of `+' symbols representing the nesting depth.
3501 The source command now has a `-v' option to enable the same feature.
3505 The ARM Demon monitor support (RDP protocol, "target rdp").
3507 Kernel Object Display, an embedded debugging feature which only worked with
3508 an obsolete version of Cisco IOS.
3510 The 'set download-write-size' and 'show download-write-size' commands.
3512 * New remote packets
3515 Tell a stub about GDB client features, and request remote target features.
3516 The first feature implemented is PacketSize, which allows the target to
3517 specify the size of packets it can handle - to minimize the number of
3518 packets required and improve performance when connected to a remote
3522 Fetch an OS auxilliary vector from the remote stub. This packet is a
3523 more efficient replacement for qPart:auxv:read.
3525 qXfer:memory-map:read:
3526 Fetch a memory map from the remote stub, including information about
3527 RAM, ROM, and flash memory devices.
3532 Erase and program a flash memory device.
3534 * Removed remote packets
3537 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3538 used it, and only gdbserver implemented it.
3540 *** Changes in GDB 6.5
3544 Renesas M32C/M16C m32c-elf
3546 Morpho Technologies ms1 ms1-elf
3550 init-if-undefined Initialize a convenience variable, but
3551 only if it doesn't already have a value.
3553 The following commands are presently only implemented for native GNU/Linux:
3555 checkpoint Save a snapshot of the program state.
3557 restart <n> Return the program state to a
3558 previously saved state.
3560 info checkpoints List currently saved checkpoints.
3562 delete-checkpoint <n> Delete a previously saved checkpoint.
3564 set|show detach-on-fork Tell gdb whether to detach from a newly
3565 forked process, or to keep debugging it.
3567 info forks List forks of the user program that
3568 are available to be debugged.
3570 fork <n> Switch to debugging one of several
3571 forks of the user program that are
3572 available to be debugged.
3574 delete-fork <n> Delete a fork from the list of forks
3575 that are available to be debugged (and
3576 kill the forked process).
3578 detach-fork <n> Delete a fork from the list of forks
3579 that are available to be debugged (and
3580 allow the process to continue).
3584 Morpho Technologies ms2 ms1-elf
3586 * Improved Windows host support
3588 GDB now builds as a cross debugger hosted on i686-mingw32, including
3589 native console support, and remote communications using either
3590 network sockets or serial ports.
3592 * Improved Modula-2 language support
3594 GDB can now print most types in the Modula-2 syntax. This includes:
3595 basic types, set types, record types, enumerated types, range types,
3596 pointer types and ARRAY types. Procedure var parameters are correctly
3597 printed and hexadecimal addresses and character constants are also
3598 written in the Modula-2 syntax. Best results can be obtained by using
3599 GNU Modula-2 together with the -gdwarf-2 command line option.
3603 The ARM rdi-share module.
3605 The Netware NLM debug server.
3607 *** Changes in GDB 6.4
3609 * New native configurations
3611 OpenBSD/arm arm*-*-openbsd*
3612 OpenBSD/mips64 mips64-*-openbsd*
3616 Morpho Technologies ms1 ms1-elf
3618 * New command line options
3620 --batch-silent As for --batch, but totally silent.
3621 --return-child-result The debugger will exist with the same value
3622 the child (debugged) program exited with.
3623 --eval-command COMMAND, -ex COMMAND
3624 Execute a single GDB CLI command. This may be
3625 specified multiple times and in conjunction
3626 with the --command (-x) option.
3628 * Deprecated commands removed
3630 The following commands, that were deprecated in 2000, have been
3634 set|show arm disassembly-flavor set|show arm disassembler
3635 othernames set arm disassembler
3636 set|show remotedebug set|show debug remote
3637 set|show archdebug set|show debug arch
3638 set|show eventdebug set|show debug event
3641 * New BSD user-level threads support
3643 It is now possible to debug programs using the user-level threads
3644 library on OpenBSD and FreeBSD. Currently supported (target)
3647 FreeBSD/amd64 x86_64-*-freebsd*
3648 FreeBSD/i386 i386-*-freebsd*
3649 OpenBSD/i386 i386-*-openbsd*
3651 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3652 are not yet supported.
3654 * New support for Matsushita MN10300 w/sim added
3655 (Work in progress). mn10300-elf.
3657 * REMOVED configurations and files
3659 VxWorks and the XDR protocol *-*-vxworks
3660 Motorola MCORE mcore-*-*
3661 National Semiconductor NS32000 ns32k-*-*
3663 * New "set print array-indexes" command
3665 After turning this setting "on", GDB prints the index of each element
3666 when displaying arrays. The default is "off" to preserve the previous
3669 * VAX floating point support
3671 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3673 * User-defined command support
3675 In addition to using $arg0..$arg9 for argument passing, it is now possible
3676 to use $argc to determine now many arguments have been passed. See the
3677 section on user-defined commands in the user manual for more information.
3679 *** Changes in GDB 6.3:
3681 * New command line option
3683 GDB now accepts -l followed by a number to set the timeout for remote
3686 * GDB works with GCC -feliminate-dwarf2-dups
3688 GDB now supports a more compact representation of DWARF-2 debug
3689 information using DW_FORM_ref_addr references. These are produced
3690 by GCC with the option -feliminate-dwarf2-dups and also by some
3691 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3692 to use -feliminate-dwarf2-dups.
3694 * Internationalization
3696 When supported by the host system, GDB will be built with
3697 internationalization (libintl). The task of marking up the sources is
3698 continued, we're looking forward to our first translation.
3702 Initial support for debugging programs compiled with the GNAT
3703 implementation of the Ada programming language has been integrated
3704 into GDB. In this release, support is limited to expression evaluation.
3706 * New native configurations
3708 GNU/Linux/m32r m32r-*-linux-gnu
3712 GDB's remote protocol now includes support for the 'p' packet. This
3713 packet is used to fetch individual registers from a remote inferior.
3715 * END-OF-LIFE registers[] compatibility module
3717 GDB's internal register infrastructure has been completely rewritten.
3718 The new infrastructure making possible the implementation of key new
3719 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3722 GDB 6.3 will be the last release to include the the registers[]
3723 compatibility module that allowed out-of-date configurations to
3724 continue to work. This change directly impacts the following
3734 powerpc bdm protocol
3736 Unless there is activity to revive these configurations, they will be
3737 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3739 * OBSOLETE configurations and files
3741 Configurations that have been declared obsolete in this release have
3742 been commented out. Unless there is activity to revive these
3743 configurations, the next release of GDB will have their sources
3744 permanently REMOVED.
3753 *** Changes in GDB 6.2.1:
3755 * MIPS `break main; run' gave an heuristic-fence-post warning
3757 When attempting to run even a simple program, a warning about
3758 heuristic-fence-post being hit would be reported. This problem has
3761 * MIPS IRIX 'long double' crashed GDB
3763 When examining a long double variable, GDB would get a segmentation
3764 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3765 IRIX long double values).
3769 A bug in the VAX stack code was causing problems with the "next"
3770 command. This problem has been fixed.
3772 *** Changes in GDB 6.2:
3774 * Fix for ``many threads''
3776 On GNU/Linux systems that use the NPTL threads library, a program
3777 rapidly creating and deleting threads would confuse GDB leading to the
3780 ptrace: No such process.
3781 thread_db_get_info: cannot get thread info: generic error
3783 This problem has been fixed.
3785 * "-async" and "-noasync" options removed.
3787 Support for the broken "-noasync" option has been removed (it caused
3790 * New ``start'' command.
3792 This command runs the program until the begining of the main procedure.
3794 * New BSD Kernel Data Access Library (libkvm) interface
3796 Using ``target kvm'' it is now possible to debug kernel core dumps and
3797 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3798 platforms. Currently supported (native-only) configurations are:
3800 FreeBSD/amd64 x86_64-*-freebsd*
3801 FreeBSD/i386 i?86-*-freebsd*
3802 NetBSD/i386 i?86-*-netbsd*
3803 NetBSD/m68k m68*-*-netbsd*
3804 NetBSD/sparc sparc-*-netbsd*
3805 OpenBSD/amd64 x86_64-*-openbsd*
3806 OpenBSD/i386 i?86-*-openbsd*
3807 OpenBSD/m68k m68*-openbsd*
3808 OpenBSD/sparc sparc-*-openbsd*
3810 * Signal trampoline code overhauled
3812 Many generic problems with GDB's signal handling code have been fixed.
3813 These include: backtraces through non-contiguous stacks; recognition
3814 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3815 call; backtrace through a signal trampoline; step into and out of
3816 signal handlers; and single-stepping in the signal trampoline.
3818 Please note that kernel bugs are a limiting factor here. These
3819 features have been shown to work on an s390 GNU/Linux system that
3820 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3822 * Cygwin support for DWARF 2 added.
3824 * New native configurations
3826 GNU/Linux/hppa hppa*-*-linux*
3827 OpenBSD/hppa hppa*-*-openbsd*
3828 OpenBSD/m68k m68*-*-openbsd*
3829 OpenBSD/m88k m88*-*-openbsd*
3830 OpenBSD/powerpc powerpc-*-openbsd*
3831 NetBSD/vax vax-*-netbsd*
3832 OpenBSD/vax vax-*-openbsd*
3834 * END-OF-LIFE frame compatibility module
3836 GDB's internal frame infrastructure has been completely rewritten.
3837 The new infrastructure making it possible to support key new features
3838 including DWARF 2 Call Frame Information. To aid in the task of
3839 migrating old configurations to this new infrastructure, a
3840 compatibility module, that allowed old configurations to continue to
3841 work, was also included.
3843 GDB 6.2 will be the last release to include this frame compatibility
3844 module. This change directly impacts the following configurations:
3854 Unless there is activity to revive these configurations, they will be
3855 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3857 * REMOVED configurations and files
3859 Sun 3, running SunOS 3 m68*-*-sunos3*
3860 Sun 3, running SunOS 4 m68*-*-sunos4*
3861 Sun 2, running SunOS 3 m68000-*-sunos3*
3862 Sun 2, running SunOS 4 m68000-*-sunos4*
3863 Motorola 680x0 running LynxOS m68*-*-lynxos*
3864 AT&T 3b1/Unix pc m68*-att-*
3865 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3866 decstation mips-dec-* mips-little-*
3867 riscos mips-*-riscos* mips-*-sysv*
3868 sonymips mips-sony-*
3869 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3871 *** Changes in GDB 6.1.1:
3873 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3875 The TUI (Text-mode User Interface) is now built as part of a default
3876 GDB configuration. It is enabled by either selecting the TUI with the
3877 command line option "-i=tui" or by running the separate "gdbtui"
3878 program. For more information on the TUI, see the manual "Debugging
3881 * Pending breakpoint support (also included in GDB 6.1)
3883 Support has been added to allow you to specify breakpoints in shared
3884 libraries that have not yet been loaded. If a breakpoint location
3885 cannot be found, and the "breakpoint pending" option is set to auto,
3886 GDB queries you if you wish to make the breakpoint pending on a future
3887 shared-library load. If and when GDB resolves the breakpoint symbol,
3888 the pending breakpoint is removed as one or more regular breakpoints
3891 Pending breakpoints are very useful for GCJ Java debugging.
3893 * Fixed ISO-C build problems
3895 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3896 non ISO-C code that stopped them being built using a more strict ISO-C
3897 compiler (e.g., IBM's C compiler).
3899 * Fixed build problem on IRIX 5
3901 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3902 wasn't able to compile compile on an IRIX 5 system.
3904 * Added execute permission to gdb/gdbserver/configure
3906 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3907 permission. This bug would cause configure to fail on a number of
3908 systems (Solaris, IRIX). Ref: server/519.
3910 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3912 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3913 has been updated to use constant array sizes.
3915 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3917 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3918 its generated DWARF Call Frame Info. This encoding was causing GDB to
3919 panic, that panic has been fixed. Ref: gdb/1628.
3921 * Fixed a problem when examining parameters in shared library code.
3923 When examining parameters in optimized shared library code generated
3924 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3925 not available''. GDB now correctly displays the variable's value.
3927 *** Changes in GDB 6.1:
3929 * Removed --with-mmalloc
3931 Support for the mmalloc memory manager has been removed, as it
3932 conflicted with the internal gdb byte cache.
3934 * Changes in AMD64 configurations
3936 The AMD64 target now includes the %cs and %ss registers. As a result
3937 the AMD64 remote protocol has changed; this affects the floating-point
3938 and SSE registers. If you rely on those registers for your debugging,
3939 you should upgrade gdbserver on the remote side.
3941 * Revised SPARC target
3943 The SPARC target has been completely revised, incorporating the
3944 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3945 support for LynxOS and SunOS 4 has been dropped. Calling functions
3946 from within GDB on operating systems with a non-executable stack
3947 (Solaris, OpenBSD) now works.
3951 GDB has a new C++ demangler which does a better job on the mangled
3952 names generated by current versions of g++. It also runs faster, so
3953 with this and other changes gdb should now start faster on large C++
3956 * DWARF 2 Location Expressions
3958 GDB support for location expressions has been extended to support function
3959 arguments and frame bases. Older versions of GDB could crash when they
3962 * C++ nested types and namespaces
3964 GDB's support for nested types and namespaces in C++ has been
3965 improved, especially if you use the DWARF 2 debugging format. (This
3966 is the default for recent versions of GCC on most platforms.)
3967 Specifically, if you have a class "Inner" defined within a class or
3968 namespace "Outer", then GDB realizes that the class's name is
3969 "Outer::Inner", not simply "Inner". This should greatly reduce the
3970 frequency of complaints about not finding RTTI symbols. In addition,
3971 if you are stopped at inside of a function defined within a namespace,
3972 GDB modifies its name lookup accordingly.
3974 * New native configurations
3976 NetBSD/amd64 x86_64-*-netbsd*
3977 OpenBSD/amd64 x86_64-*-openbsd*
3978 OpenBSD/alpha alpha*-*-openbsd*
3979 OpenBSD/sparc sparc-*-openbsd*
3980 OpenBSD/sparc64 sparc64-*-openbsd*
3982 * New debugging protocols
3984 M32R with SDI protocol m32r-*-elf*
3986 * "set prompt-escape-char" command deleted.
3988 The command "set prompt-escape-char" has been deleted. This command,
3989 and its very obscure effet on GDB's prompt, was never documented,
3990 tested, nor mentioned in the NEWS file.
3992 * OBSOLETE configurations and files
3994 Configurations that have been declared obsolete in this release have
3995 been commented out. Unless there is activity to revive these
3996 configurations, the next release of GDB will have their sources
3997 permanently REMOVED.
3999 Sun 3, running SunOS 3 m68*-*-sunos3*
4000 Sun 3, running SunOS 4 m68*-*-sunos4*
4001 Sun 2, running SunOS 3 m68000-*-sunos3*
4002 Sun 2, running SunOS 4 m68000-*-sunos4*
4003 Motorola 680x0 running LynxOS m68*-*-lynxos*
4004 AT&T 3b1/Unix pc m68*-att-*
4005 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4006 decstation mips-dec-* mips-little-*
4007 riscos mips-*-riscos* mips-*-sysv*
4008 sonymips mips-sony-*
4009 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4011 * REMOVED configurations and files
4013 SGI Irix-4.x mips-sgi-irix4 or iris4
4014 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4015 Z8000 simulator z8k-zilog-none or z8ksim
4016 Matsushita MN10200 w/simulator mn10200-*-*
4017 H8/500 simulator h8500-hitachi-hms or h8500hms
4018 HP/PA running BSD hppa*-*-bsd*
4019 HP/PA running OSF/1 hppa*-*-osf*
4020 HP/PA Pro target hppa*-*-pro*
4021 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4022 386BSD i[3456]86-*-bsd*
4023 Sequent family i[3456]86-sequent-sysv4*
4024 i[3456]86-sequent-sysv*
4025 i[3456]86-sequent-bsd*
4026 SPARC running LynxOS sparc-*-lynxos*
4027 SPARC running SunOS 4 sparc-*-sunos4*
4028 Tsqware Sparclet sparclet-*-*
4029 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4031 *** Changes in GDB 6.0:
4035 Support for debugging the Objective-C programming language has been
4036 integrated into GDB.
4038 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4040 DWARF 2's Call Frame Information makes available compiler generated
4041 information that more exactly describes the program's run-time stack.
4042 By using this information, GDB is able to provide more robust stack
4045 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4046 have been updated to use a new backtrace mechanism which includes
4047 DWARF 2 CFI support.
4051 GDB's remote protocol has been extended to include support for hosted
4052 file I/O (where the remote target uses GDB's file system). See GDB's
4053 remote protocol documentation for details.
4055 * All targets using the new architecture framework.
4057 All of GDB's targets have been updated to use the new internal
4058 architecture framework. The way is now open for future GDB releases
4059 to include cross-architecture native debugging support (i386 on amd64,
4062 * GNU/Linux's Thread Local Storage (TLS)
4064 GDB now includes support for for the GNU/Linux implementation of
4065 per-thread variables.
4067 * GNU/Linux's Native POSIX Thread Library (NPTL)
4069 GDB's thread code has been updated to work with either the new
4070 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4072 * Separate debug info.
4074 GDB, in conjunction with BINUTILS, now supports a mechanism for
4075 automatically loading debug information from a separate file. Instead
4076 of shipping full debug and non-debug versions of system libraries,
4077 system integrators can now instead ship just the stripped libraries
4078 and optional debug files.
4080 * DWARF 2 Location Expressions
4082 DWARF 2 Location Expressions allow the compiler to more completely
4083 describe the location of variables (even in optimized code) to the
4086 GDB now includes preliminary support for location expressions (support
4087 for DW_OP_piece is still missing).
4091 A number of long standing bugs that caused GDB to die while starting a
4092 Java application have been fixed. GDB's Java support is now
4093 considered "useable".
4095 * GNU/Linux support for fork, vfork, and exec.
4097 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4098 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4101 * GDB supports logging output to a file
4103 There are two new commands, "set logging" and "show logging", which can be
4104 used to capture GDB's output to a file.
4106 * The meaning of "detach" has changed for gdbserver
4108 The "detach" command will now resume the application, as documented. To
4109 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4112 * d10v, m68hc11 `regs' command deprecated
4114 The `info registers' command has been updated so that it displays the
4115 registers using a format identical to the old `regs' command.
4119 A new command, "maint set profile on/off", has been added. This command can
4120 be used to enable or disable profiling while running GDB, to profile a
4121 session or a set of commands. In addition there is a new configure switch,
4122 "--enable-profiling", which will cause GDB to be compiled with profiling
4123 data, for more informative profiling results.
4125 * Default MI syntax changed to "mi2".
4127 The default MI (machine interface) syntax, enabled by the command line
4128 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4129 "mi1", can be enabled by specifying the option "-i=mi1".
4131 Support for the original "mi0" syntax (included in GDB 5.0) has been
4134 Fix for gdb/192: removed extraneous space when displaying frame level.
4135 Fix for gdb/672: update changelist is now output in mi list format.
4136 Fix for gdb/702: a -var-assign that updates the value now shows up
4137 in a subsequent -var-update.
4139 * New native configurations.
4141 FreeBSD/amd64 x86_64-*-freebsd*
4143 * Multi-arched targets.
4145 HP/PA HPUX11 hppa*-*-hpux*
4146 Renesas M32R/D w/simulator m32r-*-elf*
4148 * OBSOLETE configurations and files
4150 Configurations that have been declared obsolete in this release have
4151 been commented out. Unless there is activity to revive these
4152 configurations, the next release of GDB will have their sources
4153 permanently REMOVED.
4155 Z8000 simulator z8k-zilog-none or z8ksim
4156 Matsushita MN10200 w/simulator mn10200-*-*
4157 H8/500 simulator h8500-hitachi-hms or h8500hms
4158 HP/PA running BSD hppa*-*-bsd*
4159 HP/PA running OSF/1 hppa*-*-osf*
4160 HP/PA Pro target hppa*-*-pro*
4161 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4162 Sequent family i[3456]86-sequent-sysv4*
4163 i[3456]86-sequent-sysv*
4164 i[3456]86-sequent-bsd*
4165 Tsqware Sparclet sparclet-*-*
4166 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4168 * REMOVED configurations and files
4171 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4172 IBM AIX PS/2 i[3456]86-*-aix
4173 i386 running Mach 3.0 i[3456]86-*-mach3*
4174 i386 running Mach i[3456]86-*-mach*
4175 i386 running OSF/1 i[3456]86-*osf1mk*
4176 HP/Apollo 68k Family m68*-apollo*-sysv*,
4178 m68*-hp-bsd*, m68*-hp-hpux*
4179 Argonaut Risc Chip (ARC) arc-*-*
4180 Mitsubishi D30V d30v-*-*
4181 Fujitsu FR30 fr30-*-elf*
4182 OS/9000 i[34]86-*-os9k
4183 I960 with MON960 i960-*-coff
4185 * MIPS $fp behavior changed
4187 The convenience variable $fp, for the MIPS, now consistently returns
4188 the address of the current frame's base. Previously, depending on the
4189 context, $fp could refer to either $sp or the current frame's base
4190 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4191 The GNU Source-Level Debugger''.
4193 *** Changes in GDB 5.3:
4195 * GNU/Linux shared library multi-threaded performance improved.
4197 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4198 `/proc', in preference to `ptrace' for memory reads. This may result
4199 in an improvement in the start-up time of multi-threaded, shared
4200 library applications when run under GDB. One GDB user writes: ``loads
4201 shared libs like mad''.
4203 * ``gdbserver'' now supports multi-threaded applications on some targets
4205 Support for debugging multi-threaded applications which use
4206 the GNU/Linux LinuxThreads package has been added for
4207 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4208 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4210 * GDB now supports C/C++ preprocessor macros.
4212 GDB now expands preprocessor macro invocations in C/C++ expressions,
4213 and provides various commands for showing macro definitions and how
4216 The new command `macro expand EXPRESSION' expands any macro
4217 invocations in expression, and shows the result.
4219 The new command `show macro MACRO-NAME' shows the definition of the
4220 macro named MACRO-NAME, and where it was defined.
4222 Most compilers don't include information about macros in the debugging
4223 information by default. In GCC 3.1, for example, you need to compile
4224 your program with the options `-gdwarf-2 -g3'. If the macro
4225 information is present in the executable, GDB will read it.
4227 * Multi-arched targets.
4229 DEC Alpha (partial) alpha*-*-*
4230 DEC VAX (partial) vax-*-*
4232 National Semiconductor NS32000 (partial) ns32k-*-*
4233 Motorola 68000 (partial) m68k-*-*
4234 Motorola MCORE mcore-*-*
4238 Fujitsu FRV architecture added by Red Hat frv*-*-*
4241 * New native configurations
4243 Alpha NetBSD alpha*-*-netbsd*
4244 SH NetBSD sh*-*-netbsdelf*
4245 MIPS NetBSD mips*-*-netbsd*
4246 UltraSPARC NetBSD sparc64-*-netbsd*
4248 * OBSOLETE configurations and files
4250 Configurations that have been declared obsolete in this release have
4251 been commented out. Unless there is activity to revive these
4252 configurations, the next release of GDB will have their sources
4253 permanently REMOVED.
4255 Mitsubishi D30V d30v-*-*
4256 OS/9000 i[34]86-*-os9k
4257 IBM AIX PS/2 i[3456]86-*-aix
4258 Fujitsu FR30 fr30-*-elf*
4259 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4260 Argonaut Risc Chip (ARC) arc-*-*
4261 i386 running Mach 3.0 i[3456]86-*-mach3*
4262 i386 running Mach i[3456]86-*-mach*
4263 i386 running OSF/1 i[3456]86-*osf1mk*
4264 HP/Apollo 68k Family m68*-apollo*-sysv*,
4266 m68*-hp-bsd*, m68*-hp-hpux*
4267 I960 with MON960 i960-*-coff
4269 * OBSOLETE languages
4271 CHILL, a Pascal like language used by telecommunications companies.
4273 * REMOVED configurations and files
4275 AMD 29k family via UDI a29k-amd-udi, udi29k
4276 A29K VxWorks a29k-*-vxworks
4277 AMD 29000 embedded, using EBMON a29k-none-none
4278 AMD 29000 embedded with COFF a29k-none-coff
4279 AMD 29000 embedded with a.out a29k-none-aout
4281 testsuite/gdb.hp/gdb.threads-hp/ directory
4283 * New command "set max-user-call-depth <nnn>"
4285 This command allows the user to limit the call depth of user-defined
4286 commands. The default is 1024.
4288 * Changes in FreeBSD/i386 native debugging.
4290 Support for the "generate-core-file" has been added.
4292 * New commands "dump", "append", and "restore".
4294 These commands allow data to be copied from target memory
4295 to a bfd-format or binary file (dump and append), and back
4296 from a file into memory (restore).
4298 * Improved "next/step" support on multi-processor Alpha Tru64.
4300 The previous single-step mechanism could cause unpredictable problems,
4301 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4302 of a software single-step mechanism prevents this.
4304 *** Changes in GDB 5.2.1:
4312 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4313 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4314 Fix, by Joel Brobecker imported from mainline.
4316 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4317 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4318 Fix, by Fred Fish, imported from mainline.
4320 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4321 Surprisingly enough, it works now.
4322 By Michal Ludvig, imported from mainline.
4324 i386 hardware watchpoint support:
4325 avoid misses on second run for some targets.
4326 By Pierre Muller, imported from mainline.
4328 *** Changes in GDB 5.2:
4330 * New command "set trust-readonly-sections on[off]".
4332 This command is a hint that tells gdb that read-only sections
4333 really are read-only (ie. that their contents will not change).
4334 In this mode, gdb will go to the object file rather than the
4335 target to read memory from read-only sections (such as ".text").
4336 This can be a significant performance improvement on some
4337 (notably embedded) targets.
4339 * New command "generate-core-file" (or "gcore").
4341 This new gdb command allows the user to drop a core file of the child
4342 process state at any time. So far it's been implemented only for
4343 GNU/Linux and Solaris, but should be relatively easily ported to other
4344 hosts. Argument is core file name (defaults to core.<pid>).
4346 * New command line option
4348 GDB now accepts --pid or -p followed by a process id.
4350 * Change in command line behavior -- corefiles vs. process ids.
4352 There is a subtle behavior in the way in which GDB handles
4353 command line arguments. The first non-flag argument is always
4354 a program to debug, but the second non-flag argument may either
4355 be a corefile or a process id. Previously, GDB would attempt to
4356 open the second argument as a corefile, and if that failed, would
4357 issue a superfluous error message and then attempt to attach it as
4358 a process. Now, if the second argument begins with a non-digit,
4359 it will be treated as a corefile. If it begins with a digit,
4360 GDB will attempt to attach it as a process, and if no such process
4361 is found, will then attempt to open it as a corefile.
4363 * Changes in ARM configurations.
4365 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4366 configuration is fully multi-arch.
4368 * New native configurations
4370 ARM NetBSD arm*-*-netbsd*
4371 x86 OpenBSD i[3456]86-*-openbsd*
4372 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4373 Sparc64 running FreeBSD sparc64-*-freebsd*
4377 Sanyo XStormy16 xstormy16-elf
4379 * OBSOLETE configurations and files
4381 Configurations that have been declared obsolete in this release have
4382 been commented out. Unless there is activity to revive these
4383 configurations, the next release of GDB will have their sources
4384 permanently REMOVED.
4386 AMD 29k family via UDI a29k-amd-udi, udi29k
4387 A29K VxWorks a29k-*-vxworks
4388 AMD 29000 embedded, using EBMON a29k-none-none
4389 AMD 29000 embedded with COFF a29k-none-coff
4390 AMD 29000 embedded with a.out a29k-none-aout
4392 testsuite/gdb.hp/gdb.threads-hp/ directory
4394 * REMOVED configurations and files
4396 TI TMS320C80 tic80-*-*
4398 PowerPC Solaris powerpcle-*-solaris*
4399 PowerPC Windows NT powerpcle-*-cygwin32
4400 PowerPC Netware powerpc-*-netware*
4401 Harris/CXUX m88k m88*-harris-cxux*
4402 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4403 ns32k-utek-sysv* ns32k-utek-*
4404 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4405 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4406 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4407 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4408 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4410 * Changes to command line processing
4412 The new `--args' feature can be used to specify command-line arguments
4413 for the inferior from gdb's command line.
4415 * Changes to key bindings
4417 There is a new `operate-and-get-next' function bound to `C-o'.
4419 *** Changes in GDB 5.1.1
4421 Fix compile problem on DJGPP.
4423 Fix a problem with floating-point registers on the i386 being
4426 Fix to stop GDB crashing on .debug_str debug info.
4428 Numerous documentation fixes.
4430 Numerous testsuite fixes.
4432 *** Changes in GDB 5.1:
4434 * New native configurations
4436 Alpha FreeBSD alpha*-*-freebsd*
4437 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4438 MIPS GNU/Linux mips*-*-linux*
4439 MIPS SGI Irix 6.x mips*-sgi-irix6*
4440 ia64 AIX ia64-*-aix*
4441 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4445 Motorola 68HC11 and 68HC12 m68hc11-elf
4447 UltraSparc running GNU/Linux sparc64-*-linux*
4449 * OBSOLETE configurations and files
4451 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4452 Harris/CXUX m88k m88*-harris-cxux*
4453 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4454 ns32k-utek-sysv* ns32k-utek-*
4455 TI TMS320C80 tic80-*-*
4457 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4458 PowerPC Solaris powerpcle-*-solaris*
4459 PowerPC Windows NT powerpcle-*-cygwin32
4460 PowerPC Netware powerpc-*-netware*
4461 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4462 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4463 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4464 Apple Macintosh (MPW) host N/A
4466 stuff.c (Program to stuff files into a specially prepared space in kdb)
4467 kdb-start.c (Main loop for the standalone kernel debugger)
4469 Configurations that have been declared obsolete in this release have
4470 been commented out. Unless there is activity to revive these
4471 configurations, the next release of GDB will have their sources
4472 permanently REMOVED.
4474 * REMOVED configurations and files
4476 Altos 3068 m68*-altos-*
4477 Convex c1-*-*, c2-*-*
4479 ARM RISCix arm-*-* (as host)
4483 * GDB has been converted to ISO C.
4485 GDB's source code has been converted to ISO C. In particular, the
4486 sources are fully protoized, and rely on standard headers being
4491 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4493 * The MI enabled by default.
4495 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4496 revised and enabled by default. Packages which use GDB as a debugging
4497 engine behind a UI or another front end are encouraged to switch to
4498 using the GDB/MI interface, instead of the old annotations interface
4499 which is now deprecated.
4501 * Support for debugging Pascal programs.
4503 GDB now includes support for debugging Pascal programs. The following
4504 main features are supported:
4506 - Pascal-specific data types such as sets;
4508 - automatic recognition of Pascal sources based on file-name
4511 - Pascal-style display of data types, variables, and functions;
4513 - a Pascal expression parser.
4515 However, some important features are not yet supported.
4517 - Pascal string operations are not supported at all;
4519 - there are some problems with boolean types;
4521 - Pascal type hexadecimal constants are not supported
4522 because they conflict with the internal variables format;
4524 - support for Pascal objects and classes is not full yet;
4526 - unlike Pascal, GDB is case-sensitive for symbol names.
4528 * Changes in completion.
4530 Commands such as `shell', `run' and `set args', which pass arguments
4531 to inferior programs, now complete on file names, similar to what
4532 users expect at the shell prompt.
4534 Commands which accept locations, such as `disassemble', `print',
4535 `breakpoint', `until', etc. now complete on filenames as well as
4536 program symbols. Thus, if you type "break foob TAB", and the source
4537 files linked into the programs include `foobar.c', that file name will
4538 be one of the candidates for completion. However, file names are not
4539 considered for completion after you typed a colon that delimits a file
4540 name from a name of a function in that file, as in "break foo.c:bar".
4542 `set demangle-style' completes on available demangling styles.
4544 * New platform-independent commands:
4546 It is now possible to define a post-hook for a command as well as a
4547 hook that runs before the command. For more details, see the
4548 documentation of `hookpost' in the GDB manual.
4550 * Changes in GNU/Linux native debugging.
4552 Support for debugging multi-threaded programs has been completely
4553 revised for all platforms except m68k and sparc. You can now debug as
4554 many threads as your system allows you to have.
4556 Attach/detach is supported for multi-threaded programs.
4558 Support for SSE registers was added for x86. This doesn't work for
4559 multi-threaded programs though.
4561 * Changes in MIPS configurations.
4563 Multi-arch support is enabled for all MIPS configurations.
4565 GDB can now be built as native debugger on SGI Irix 6.x systems for
4566 debugging n32 executables. (Debugging 64-bit executables is not yet
4569 * Unified support for hardware watchpoints in all x86 configurations.
4571 Most (if not all) native x86 configurations support hardware-assisted
4572 breakpoints and watchpoints in a unified manner. This support
4573 implements debug register sharing between watchpoints, which allows to
4574 put a virtually infinite number of watchpoints on the same address,
4575 and also supports watching regions up to 16 bytes with several debug
4578 The new maintenance command `maintenance show-debug-regs' toggles
4579 debugging print-outs in functions that insert, remove, and test
4580 watchpoints and hardware breakpoints.
4582 * Changes in the DJGPP native configuration.
4584 New command ``info dos sysinfo'' displays assorted information about
4585 the CPU, OS, memory, and DPMI server.
4587 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4588 display information about segment descriptors stored in GDT, LDT, and
4591 New commands ``info dos pde'' and ``info dos pte'' display entries
4592 from Page Directory and Page Tables (for now works with CWSDPMI only).
4593 New command ``info dos address-pte'' displays the Page Table entry for
4594 a given linear address.
4596 GDB can now pass command lines longer than 126 characters to the
4597 program being debugged (requires an update to the libdbg.a library
4598 which is part of the DJGPP development kit).
4600 DWARF2 debug info is now supported.
4602 It is now possible to `step' and `next' through calls to `longjmp'.
4604 * Changes in documentation.
4606 All GDB documentation was converted to GFDL, the GNU Free
4607 Documentation License.
4609 Tracepoints-related commands are now fully documented in the GDB
4612 TUI, the Text-mode User Interface, is now documented in the manual.
4614 Tracepoints-related commands are now fully documented in the GDB
4617 The "GDB Internals" manual now has an index. It also includes
4618 documentation of `ui_out' functions, GDB coding standards, x86
4619 hardware watchpoints, and memory region attributes.
4621 * GDB's version number moved to ``version.in''
4623 The Makefile variable VERSION has been replaced by the file
4624 ``version.in''. People creating GDB distributions should update the
4625 contents of this file.
4629 GUD support is now a standard part of the EMACS distribution.
4631 *** Changes in GDB 5.0:
4633 * Improved support for debugging FP programs on x86 targets
4635 Unified and much-improved support for debugging floating-point
4636 programs on all x86 targets. In particular, ``info float'' now
4637 displays the FP registers in the same format on all x86 targets, with
4638 greater level of detail.
4640 * Improvements and bugfixes in hardware-assisted watchpoints
4642 It is now possible to watch array elements, struct members, and
4643 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4644 on x86 targets no longer erroneously trigger when the address is
4647 * Improvements in the native DJGPP version of GDB
4649 The distribution now includes all the scripts and auxiliary files
4650 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4651 machines ``out of the box''.
4653 The DJGPP version can now debug programs that use signals. It is
4654 possible to catch signals that happened in the debuggee, deliver
4655 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4656 would kill the program being debugged.) Programs that hook hardware
4657 interrupts (keyboard, timer, etc.) can also be debugged.
4659 It is now possible to debug DJGPP programs that redirect their
4660 standard handles or switch them to raw (as opposed to cooked) mode, or
4661 even close them. The command ``run < foo > bar'' works as expected,
4662 and ``info terminal'' reports useful information about the debuggee's
4663 terminal, including raw/cooked mode, redirection, etc.
4665 The DJGPP version now uses termios functions for console I/O, which
4666 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4669 DOS-style file names with drive letters are now fully supported by
4672 It is now possible to debug DJGPP programs that switch their working
4673 directory. It is also possible to rerun the debuggee any number of
4674 times without restarting GDB; thus, you can use the same setup,
4675 breakpoints, etc. for many debugging sessions.
4677 * New native configurations
4679 ARM GNU/Linux arm*-*-linux*
4680 PowerPC GNU/Linux powerpc-*-linux*
4684 Motorola MCore mcore-*-*
4685 x86 VxWorks i[3456]86-*-vxworks*
4686 PowerPC VxWorks powerpc-*-vxworks*
4687 TI TMS320C80 tic80-*-*
4689 * OBSOLETE configurations
4691 Altos 3068 m68*-altos-*
4692 Convex c1-*-*, c2-*-*
4694 ARM RISCix arm-*-* (as host)
4697 Configurations that have been declared obsolete will be commented out,
4698 but the code will be left in place. If there is no activity to revive
4699 these configurations before the next release of GDB, the sources will
4700 be permanently REMOVED.
4702 * Gould support removed
4704 Support for the Gould PowerNode and NP1 has been removed.
4706 * New features for SVR4
4708 On SVR4 native platforms (such as Solaris), if you attach to a process
4709 without first loading a symbol file, GDB will now attempt to locate and
4710 load symbols from the running process's executable file.
4712 * Many C++ enhancements
4714 C++ support has been greatly improved. Overload resolution now works properly
4715 in almost all cases. RTTI support is on the way.
4717 * Remote targets can connect to a sub-program
4719 A popen(3) style serial-device has been added. This device starts a
4720 sub-process (such as a stand-alone simulator) and then communicates
4721 with that. The sub-program to run is specified using the syntax
4722 ``|<program> <args>'' vis:
4724 (gdb) set remotedebug 1
4725 (gdb) target extended-remote |mn10300-elf-sim program-args
4727 * MIPS 64 remote protocol
4729 A long standing bug in the mips64 remote protocol where by GDB
4730 expected certain 32 bit registers (ex SR) to be transfered as 32
4731 instead of 64 bits has been fixed.
4733 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4734 added to provide backward compatibility with older versions of GDB.
4736 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4738 The command ``set remotebinarydownload'' command has been replaced by
4739 ``set remote X-packet''. Other commands in ``set remote'' family
4740 include ``set remote P-packet''.
4742 * Breakpoint commands accept ranges.
4744 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4745 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4746 ``tracepoint passcount'' also accepts a range of tracepoints.
4748 * ``apropos'' command added.
4750 The ``apropos'' command searches through command names and
4751 documentation strings, printing out matches, making it much easier to
4752 try to find a command that does what you are looking for.
4756 A new machine oriented interface (MI) has been added to GDB. This
4757 interface is designed for debug environments running GDB as a separate
4758 process. This is part of the long term libGDB project. See the
4759 "GDB/MI" chapter of the GDB manual for further information. It can be
4760 enabled by configuring with:
4762 .../configure --enable-gdbmi
4764 *** Changes in GDB-4.18:
4766 * New native configurations
4768 HP-UX 10.20 hppa*-*-hpux10.20
4769 HP-UX 11.x hppa*-*-hpux11.0*
4770 M68K GNU/Linux m68*-*-linux*
4774 Fujitsu FR30 fr30-*-elf*
4775 Intel StrongARM strongarm-*-*
4776 Mitsubishi D30V d30v-*-*
4778 * OBSOLETE configurations
4780 Gould PowerNode, NP1 np1-*-*, pn-*-*
4782 Configurations that have been declared obsolete will be commented out,
4783 but the code will be left in place. If there is no activity to revive
4784 these configurations before the next release of GDB, the sources will
4785 be permanently REMOVED.
4789 As a compatibility experiment, GDB's source files buildsym.h and
4790 buildsym.c have been converted to pure standard C, no longer
4791 containing any K&R compatibility code. We believe that all systems in
4792 use today either come with a standard C compiler, or have a GCC port
4793 available. If this is not true, please report the affected
4794 configuration to bug-gdb@gnu.org immediately. See the README file for
4795 information about getting a standard C compiler if you don't have one
4800 GDB now uses readline 2.2.
4802 * set extension-language
4804 You can now control the mapping between filename extensions and source
4805 languages by using the `set extension-language' command. For instance,
4806 you can ask GDB to treat .c files as C++ by saying
4807 set extension-language .c c++
4808 The command `info extensions' lists all of the recognized extensions
4809 and their associated languages.
4811 * Setting processor type for PowerPC and RS/6000
4813 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4814 you can use the `set processor' command to specify what variant of the
4815 PowerPC family you are debugging. The command
4819 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4820 following PowerPC and RS6000 variants:
4822 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4823 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4825 403GC IBM PowerPC 403GC
4826 505 Motorola PowerPC 505
4827 860 Motorola PowerPC 860 or 850
4828 601 Motorola PowerPC 601
4829 602 Motorola PowerPC 602
4830 603 Motorola/IBM PowerPC 603 or 603e
4831 604 Motorola PowerPC 604 or 604e
4832 750 Motorola/IBM PowerPC 750 or 750
4834 At the moment, this command just tells GDB what to name the
4835 special-purpose processor registers. Since almost all the affected
4836 registers are inaccessible to user-level programs, this command is
4837 only useful for remote debugging in its present form.
4841 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4842 more extensive support for HP-UX. Added features include shared
4843 library support, kernel threads and hardware watchpoints for 11.00,
4844 support for HP's ANSI C and C++ compilers, and a compatibility mode
4845 for xdb and dbx commands.
4849 HP's donation includes the new concept of catchpoints, which is a
4850 generalization of the old catch command. On HP-UX, it is now possible
4851 to catch exec, fork, and vfork, as well as library loading.
4853 This means that the existing catch command has changed; its first
4854 argument now specifies the type of catch to be set up. See the
4855 output of "help catch" for a list of catchpoint types.
4857 * Debugging across forks
4859 On HP-UX, you can choose which process to debug when a fork() happens
4864 HP has donated a curses-based terminal user interface (TUI). To get
4865 it, build with --enable-tui. Although this can be enabled for any
4866 configuration, at present it only works for native HP debugging.
4868 * GDB remote protocol additions
4870 A new protocol packet 'X' that writes binary data is now available.
4871 Default behavior is to try 'X', then drop back to 'M' if the stub
4872 fails to respond. The settable variable `remotebinarydownload'
4873 allows explicit control over the use of 'X'.
4875 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4876 full 64-bit address. The command
4878 set remoteaddresssize 32
4880 can be used to revert to the old behaviour. For existing remote stubs
4881 the change should not be noticed, as the additional address information
4884 In order to assist in debugging stubs, you may use the maintenance
4885 command `packet' to send any text string to the stub. For instance,
4887 maint packet heythere
4889 sends the packet "$heythere#<checksum>". Note that it is very easy to
4890 disrupt a debugging session by sending the wrong packet at the wrong
4893 The compare-sections command allows you to compare section data on the
4894 target to what is in the executable file without uploading or
4895 downloading, by comparing CRC checksums.
4897 * Tracing can collect general expressions
4899 You may now collect general expressions at tracepoints. This requires
4900 further additions to the target-side stub; see tracepoint.c and
4901 doc/agentexpr.texi for further details.
4903 * mask-address variable for Mips
4905 For Mips targets, you may control the zeroing of the upper 32 bits of
4906 a 64-bit address by entering `set mask-address on'. This is mainly
4907 of interest to users of embedded R4xxx and R5xxx processors.
4909 * Higher serial baud rates
4911 GDB's serial code now allows you to specify baud rates 57600, 115200,
4912 230400, and 460800 baud. (Note that your host system may not be able
4913 to achieve all of these rates.)
4917 The i960 configuration now includes an initial implementation of a
4918 builtin simulator, contributed by Jim Wilson.
4921 *** Changes in GDB-4.17:
4923 * New native configurations
4925 Alpha GNU/Linux alpha*-*-linux*
4926 Unixware 2.x i[3456]86-unixware2*
4927 Irix 6.x mips*-sgi-irix6*
4928 PowerPC GNU/Linux powerpc-*-linux*
4929 PowerPC Solaris powerpcle-*-solaris*
4930 Sparc GNU/Linux sparc-*-linux*
4931 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4935 Argonaut Risc Chip (ARC) arc-*-*
4936 Hitachi H8/300S h8300*-*-*
4937 Matsushita MN10200 w/simulator mn10200-*-*
4938 Matsushita MN10300 w/simulator mn10300-*-*
4939 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4940 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4941 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4942 Mitsubishi D10V w/simulator d10v-*-*
4943 Mitsubishi M32R/D w/simulator m32r-*-elf*
4944 Tsqware Sparclet sparclet-*-*
4945 NEC V850 w/simulator v850-*-*
4947 * New debugging protocols
4949 ARM with RDI protocol arm*-*-*
4950 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4951 DDB and LSI variants of PMON protocol mips*-*-*
4952 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4953 PowerPC with SDS protocol powerpc{,le}-*-eabi
4954 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4958 All configurations can now understand and use the DWARF 2 debugging
4959 format. The choice is automatic, if the symbol file contains DWARF 2
4964 GDB now includes basic Java language support. This support is
4965 only useful with Java compilers that produce native machine code.
4967 * solib-absolute-prefix and solib-search-path
4969 For SunOS and SVR4 shared libraries, you may now set the prefix for
4970 loading absolute shared library symbol files, and the search path for
4971 locating non-absolute shared library symbol files.
4973 * Live range splitting
4975 GDB can now effectively debug code for which GCC has performed live
4976 range splitting as part of its optimization. See gdb/doc/LRS for
4977 more details on the expected format of the stabs information.
4981 GDB's support for the GNU Hurd, including thread debugging, has been
4982 updated to work with current versions of the Hurd.
4986 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4987 instruction set. ARM GDB automatically detects when Thumb
4988 instructions are in use, and adjusts disassembly and backtracing
4993 GDB's MIPS target configurations now handle the MIP16 16-bit
4998 GDB now includes support for overlays; if an executable has been
4999 linked such that multiple sections are based at the same address, GDB
5000 will decide which section to use for symbolic info. You can choose to
5001 control the decision manually, using overlay commands, or implement
5002 additional target-side support and use "overlay load-target" to bring
5003 in the overlay mapping. Do "help overlay" for more detail.
5007 The command "info symbol <address>" displays information about
5008 the symbol at the specified address.
5012 The standard remote protocol now includes an extension that allows
5013 asynchronous collection and display of trace data. This requires
5014 extensive support in the target-side debugging stub. Tracing mode
5015 includes a new interaction mode in GDB and new commands: see the
5016 file tracepoint.c for more details.
5020 Configurations for embedded MIPS now include a simulator contributed
5021 by Cygnus Solutions. The simulator supports the instruction sets
5022 of most MIPS variants.
5026 Sparc configurations may now include the ERC32 simulator contributed
5027 by the European Space Agency. The simulator is not built into
5028 Sparc targets by default; configure with --enable-sim to include it.
5032 For target configurations that may include multiple variants of a
5033 basic architecture (such as MIPS and SH), you may now set the
5034 architecture explicitly. "set arch" sets, "info arch" lists
5035 the possible architectures.
5037 *** Changes in GDB-4.16:
5039 * New native configurations
5041 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5042 M68K NetBSD m68k-*-netbsd*
5043 PowerPC AIX 4.x powerpc-*-aix*
5044 PowerPC MacOS powerpc-*-macos*
5045 PowerPC Windows NT powerpcle-*-cygwin32
5046 RS/6000 AIX 4.x rs6000-*-aix4*
5050 ARM with RDP protocol arm-*-*
5051 I960 with MON960 i960-*-coff
5052 MIPS VxWorks mips*-*-vxworks*
5053 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5054 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5056 Matra Sparclet sparclet-*-*
5060 The powerpc-eabi configuration now includes the PSIM simulator,
5061 contributed by Andrew Cagney, with assistance from Mike Meissner.
5062 PSIM is a very elaborate model of the PowerPC, including not only
5063 basic instruction set execution, but also details of execution unit
5064 performance and I/O hardware. See sim/ppc/README for more details.
5068 GDB now works with Solaris 2.5.
5070 * Windows 95/NT native
5072 GDB will now work as a native debugger on Windows 95 and Windows NT.
5073 To build it from source, you must use the "gnu-win32" environment,
5074 which uses a DLL to emulate enough of Unix to run the GNU tools.
5075 Further information, binaries, and sources are available at
5076 ftp.cygnus.com, under pub/gnu-win32.
5078 * dont-repeat command
5080 If a user-defined command includes the command `dont-repeat', then the
5081 command will not be repeated if the user just types return. This is
5082 useful if the command is time-consuming to run, so that accidental
5083 extra keystrokes don't run the same command many times.
5085 * Send break instead of ^C
5087 The standard remote protocol now includes an option to send a break
5088 rather than a ^C to the target in order to interrupt it. By default,
5089 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5091 * Remote protocol timeout
5093 The standard remote protocol includes a new variable `remotetimeout'
5094 that allows you to set the number of seconds before GDB gives up trying
5095 to read from the target. The default value is 2.
5097 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5099 By default GDB will automatically keep track of objects as they are
5100 loaded and unloaded by the dynamic linker. By using the command `set
5101 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5102 when shared library events occur, thus allowing you to set breakpoints
5103 in shared libraries which are explicitly loaded by the inferior.
5105 Note this feature does not work on hpux8. On hpux9 you must link
5106 /usr/lib/end.o into your program. This feature should work
5107 automatically on hpux10.
5109 * Irix 5.x hardware watchpoint support
5111 Irix 5 configurations now support the use of hardware watchpoints.
5113 * Mips protocol "SYN garbage limit"
5115 When debugging a Mips target using the `target mips' protocol, you
5116 may set the number of characters that GDB will ignore by setting
5117 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5118 every character. The default value is 1050.
5120 * Recording and replaying remote debug sessions
5122 If you set `remotelogfile' to the name of a file, gdb will write to it
5123 a recording of a remote debug session. This recording may then be
5124 replayed back to gdb using "gdbreplay". See gdbserver/README for
5125 details. This is useful when you have a problem with GDB while doing
5126 remote debugging; you can make a recording of the session and send it
5127 to someone else, who can then recreate the problem.
5129 * Speedups for remote debugging
5131 GDB includes speedups for downloading and stepping MIPS systems using
5132 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5133 and more efficient S-record downloading.
5135 * Memory use reductions and statistics collection
5137 GDB now uses less memory and reports statistics about memory usage.
5138 Try the `maint print statistics' command, for example.
5140 *** Changes in GDB-4.15:
5142 * Psymtabs for XCOFF
5144 The symbol reader for AIX GDB now uses partial symbol tables. This
5145 can greatly improve startup time, especially for large executables.
5147 * Remote targets use caching
5149 Remote targets now use a data cache to speed up communication with the
5150 remote side. The data cache could lead to incorrect results because
5151 it doesn't know about volatile variables, thus making it impossible to
5152 debug targets which use memory mapped I/O devices. `set remotecache
5153 off' turns the the data cache off.
5155 * Remote targets may have threads
5157 The standard remote protocol now includes support for multiple threads
5158 in the target system, using new protocol commands 'H' and 'T'. See
5159 gdb/remote.c for details.
5163 If GDB is configured with `--enable-netrom', then it will include
5164 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5165 acts as though it is a bank of ROM on the target board, but you can
5166 write into it over the network. GDB's support consists only of
5167 support for fast loading into the emulated ROM; to debug, you must use
5168 another protocol, such as standard remote protocol. The usual
5169 sequence is something like
5171 target nrom <netrom-hostname>
5173 target remote <netrom-hostname>:1235
5177 GDB now includes support for the Apple Macintosh, as a host only. It
5178 may be run as either an MPW tool or as a standalone application, and
5179 it can debug through the serial port. All the usual GDB commands are
5180 available, but to the target command, you must supply "serial" as the
5181 device type instead of "/dev/ttyXX". See mpw-README in the main
5182 directory for more information on how to build. The MPW configuration
5183 scripts */mpw-config.in support only a few targets, and only the
5184 mips-idt-ecoff target has been tested.
5188 GDB configuration now uses autoconf. This is not user-visible,
5189 but does simplify configuration and building.
5193 GDB now supports hpux10.
5195 *** Changes in GDB-4.14:
5197 * New native configurations
5199 x86 FreeBSD i[345]86-*-freebsd
5200 x86 NetBSD i[345]86-*-netbsd
5201 NS32k NetBSD ns32k-*-netbsd
5202 Sparc NetBSD sparc-*-netbsd
5206 A29K VxWorks a29k-*-vxworks
5207 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5208 CPU32 EST-300 emulator m68*-*-est*
5209 PowerPC ELF powerpc-*-elf
5212 * Alpha OSF/1 support for procfs
5214 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5215 possible to attach to running processes. As the mounting of the /proc
5216 filesystem is optional on the Alpha, GDB automatically determines
5217 the availability of /proc during startup. This can lead to problems
5218 if /proc is unmounted after GDB has been started.
5220 * Arguments to user-defined commands
5222 User commands may accept up to 10 arguments separated by whitespace.
5223 Arguments are accessed within the user command via $arg0..$arg9. A
5226 print $arg0 + $arg1 + $arg2
5228 To execute the command use:
5231 Defines the command "adder" which prints the sum of its three arguments.
5232 Note the arguments are text substitutions, so they may reference variables,
5233 use complex expressions, or even perform inferior function calls.
5235 * New `if' and `while' commands
5237 This makes it possible to write more sophisticated user-defined
5238 commands. Both commands take a single argument, which is the
5239 expression to evaluate, and must be followed by the commands to
5240 execute, one per line, if the expression is nonzero, the list being
5241 terminated by the word `end'. The `if' command list may include an
5242 `else' word, which causes the following commands to be executed only
5243 if the expression is zero.
5245 * Fortran source language mode
5247 GDB now includes partial support for Fortran 77. It will recognize
5248 Fortran programs and can evaluate a subset of Fortran expressions, but
5249 variables and functions may not be handled correctly. GDB will work
5250 with G77, but does not yet know much about symbols emitted by other
5253 * Better HPUX support
5255 Most debugging facilities now work on dynamic executables for HPPAs
5256 running hpux9 or later. You can attach to running dynamically linked
5257 processes, but by default the dynamic libraries will be read-only, so
5258 for instance you won't be able to put breakpoints in them. To change
5259 that behavior do the following before running the program:
5265 This will cause the libraries to be mapped private and read-write.
5266 To revert to the normal behavior, do this:
5272 You cannot set breakpoints or examine data in the library until after
5273 the library is loaded if the function/data symbols do not have
5276 GDB can now also read debug symbols produced by the HP C compiler on
5277 HPPAs (sorry, no C++, Fortran or 68k support).
5279 * Target byte order now dynamically selectable
5281 You can choose which byte order to use with a target system, via the
5282 commands "set endian big" and "set endian little", and you can see the
5283 current setting by using "show endian". You can also give the command
5284 "set endian auto", in which case GDB will use the byte order
5285 associated with the executable. Currently, only embedded MIPS
5286 configurations support dynamic selection of target byte order.
5288 * New DOS host serial code
5290 This version uses DPMI interrupts to handle buffered I/O, so you
5291 no longer need to run asynctsr when debugging boards connected to
5294 *** Changes in GDB-4.13:
5296 * New "complete" command
5298 This lists all the possible completions for the rest of the line, if it
5299 were to be given as a command itself. This is intended for use by emacs.
5301 * Trailing space optional in prompt
5303 "set prompt" no longer adds a space for you after the prompt you set. This
5304 allows you to set a prompt which ends in a space or one that does not.
5306 * Breakpoint hit counts
5308 "info break" now displays a count of the number of times the breakpoint
5309 has been hit. This is especially useful in conjunction with "ignore"; you
5310 can ignore a large number of breakpoint hits, look at the breakpoint info
5311 to see how many times the breakpoint was hit, then run again, ignoring one
5312 less than that number, and this will get you quickly to the last hit of
5315 * Ability to stop printing at NULL character
5317 "set print null-stop" will cause GDB to stop printing the characters of
5318 an array when the first NULL is encountered. This is useful when large
5319 arrays actually contain only short strings.
5321 * Shared library breakpoints
5323 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5324 breakpoints in shared libraries before the executable is run.
5326 * Hardware watchpoints
5328 There is a new hardware breakpoint for the watch command for sparclite
5329 targets. See gdb/sparclite/hw_breakpoint.note.
5331 Hardware watchpoints are also now supported under GNU/Linux.
5335 Annotations have been added. These are for use with graphical interfaces,
5336 and are still experimental. Currently only gdba.el uses these.
5338 * Improved Irix 5 support
5340 GDB now works properly with Irix 5.2.
5342 * Improved HPPA support
5344 GDB now works properly with the latest GCC and GAS.
5346 * New native configurations
5348 Sequent PTX4 i[34]86-sequent-ptx4
5349 HPPA running OSF/1 hppa*-*-osf*
5350 Atari TT running SVR4 m68*-*-sysv4*
5351 RS/6000 LynxOS rs6000-*-lynxos*
5355 OS/9000 i[34]86-*-os9k
5356 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5359 * Hitachi SH7000 and E7000-PC ICE support
5361 There is now support for communicating with the Hitachi E7000-PC ICE.
5362 This is available automatically when GDB is configured for the SH.
5366 As usual, a variety of small fixes and improvements, both generic
5367 and configuration-specific. See the ChangeLog for more detail.
5369 *** Changes in GDB-4.12:
5371 * Irix 5 is now supported
5375 GDB-4.12 on the HPPA has a number of changes which make it unable
5376 to debug the output from the currently released versions of GCC and
5377 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5378 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5379 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5382 *** Changes in GDB-4.11:
5384 * User visible changes:
5388 The "set remotedebug" option is now consistent between the mips remote
5389 target, remote targets using the gdb-specific protocol, UDI (AMD's
5390 debug protocol for the 29k) and the 88k bug monitor. It is now an
5391 integer specifying a debug level (normally 0 or 1, but 2 means more
5392 debugging info for the mips target).
5394 * DEC Alpha native support
5396 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5397 debug info, but GDB works fairly well with the DEC compiler and should
5398 work with a future GCC release. See the README file for a few
5399 Alpha-specific notes.
5401 * Preliminary thread implementation
5403 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5405 * LynxOS native and target support for 386
5407 This release has been hosted on LynxOS 2.2, and also can be configured
5408 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5411 * Improvements in C++ mangling/demangling.
5413 This release has much better g++ debugging, specifically in name
5414 mangling/demangling, virtual function calls, print virtual table,
5415 call methods, ...etc.
5417 *** Changes in GDB-4.10:
5419 * User visible changes:
5421 Remote debugging using the GDB-specific (`target remote') protocol now
5422 supports the `load' command. This is only useful if you have some
5423 other way of getting the stub to the target system, and you can put it
5424 somewhere in memory where it won't get clobbered by the download.
5426 Filename completion now works.
5428 When run under emacs mode, the "info line" command now causes the
5429 arrow to point to the line specified. Also, "info line" prints
5430 addresses in symbolic form (as well as hex).
5432 All vxworks based targets now support a user settable option, called
5433 vxworks-timeout. This option represents the number of seconds gdb
5434 should wait for responses to rpc's. You might want to use this if
5435 your vxworks target is, perhaps, a slow software simulator or happens
5436 to be on the far side of a thin network line.
5440 This release contains support for using a DEC alpha as a GDB host for
5441 cross debugging. Native alpha debugging is not supported yet.
5444 *** Changes in GDB-4.9:
5448 This is the first GDB release which is accompanied by a matching testsuite.
5449 The testsuite requires installation of dejagnu, which should be available
5450 via ftp from most sites that carry GNU software.
5454 'Cfront' style demangling has had its name changed to 'ARM' style, to
5455 emphasize that it was written from the specifications in the C++ Annotated
5456 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5457 disclaimers, it still generated too much confusion with users attempting to
5458 use gdb with AT&T cfront.
5462 GDB now uses a standard remote interface to a simulator library.
5463 So far, the library contains simulators for the Zilog Z8001/2, the
5464 Hitachi H8/300, H8/500 and Super-H.
5466 * New targets supported
5468 H8/300 simulator h8300-hitachi-hms or h8300hms
5469 H8/500 simulator h8500-hitachi-hms or h8500hms
5470 SH simulator sh-hitachi-hms or sh
5471 Z8000 simulator z8k-zilog-none or z8ksim
5472 IDT MIPS board over serial line mips-idt-ecoff
5474 Cross-debugging to GO32 targets is supported. It requires a custom
5475 version of the i386-stub.c module which is integrated with the
5476 GO32 memory extender.
5478 * New remote protocols
5480 MIPS remote debugging protocol.
5482 * New source languages supported
5484 This version includes preliminary support for Chill, a Pascal like language
5485 used by telecommunications companies. Chill support is also being integrated
5486 into the GNU compiler, but we don't know when it will be publically available.
5489 *** Changes in GDB-4.8:
5491 * HP Precision Architecture supported
5493 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5494 version of this support was available as a set of patches from the
5495 University of Utah. GDB does not support debugging of programs
5496 compiled with the HP compiler, because HP will not document their file
5497 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5498 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5500 Many problems in the preliminary version have been fixed.
5502 * Faster and better demangling
5504 We have improved template demangling and fixed numerous bugs in the GNU style
5505 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5506 character types (wchar_t) are now supported. Demangling of each symbol is now
5507 only done once, and is cached when the symbol table for a file is read in.
5508 This results in a small increase in memory usage for C programs, a moderate
5509 increase in memory usage for C++ programs, and a fantastic speedup in
5512 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5513 from the specifications in the Annotated Reference Manual, which AT&T's
5514 compiler does not actually implement.
5516 * G++ multiple inheritance compiler problem
5518 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5519 inheritance lattices was reworked to properly discover ambiguities. We
5520 recently found an example which causes this new algorithm to fail in a
5521 very subtle way, producing bad debug information for those classes.
5522 The file 'gcc.patch' (in this directory) can be applied to gcc to
5523 circumvent the problem. A future GCC release will contain a complete
5526 The previous G++ debug info problem (mentioned below for the gdb-4.7
5527 release) is fixed in gcc version 2.3.2.
5529 * Improved configure script
5531 The `configure' script will now attempt to guess your system type if
5532 you don't supply a host system type. The old scheme of supplying a
5533 host system triplet is preferable over using this. All the magic is
5534 done in the new `config.guess' script. Examine it for details.
5536 We have also brought our configure script much more in line with the FSF's
5537 version. It now supports the --with-xxx options. In particular,
5538 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5539 The resulting GDB will not be able to read arbitrary object file formats --
5540 only the format ``expected'' to be used on the configured target system.
5541 We hope to make this the default in a future release.
5543 * Documentation improvements
5545 There's new internal documentation on how to modify GDB, and how to
5546 produce clean changes to the code. We implore people to read it
5547 before submitting changes.
5549 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5550 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5551 `info' files are also provided. To build `info' files from scratch,
5552 you will need the latest `makeinfo' release, which will be available in
5553 a future texinfo-X.Y release.
5555 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5556 We're not sure exactly which versions have this problem, but it has
5557 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5558 or better. If that isn't possible, there is a patch in
5559 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5560 around this problem.
5564 GDB now supports array constants that can be used in expressions typed in by
5565 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5566 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5569 The new directory `gdb/sparclite' contains a program that demonstrates
5570 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5572 * New native hosts supported
5574 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5575 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5577 * New targets supported
5579 AMD 29k family via UDI a29k-amd-udi or udi29k
5581 * New file formats supported
5583 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5584 HPUX core files, and SCO 3.2v2 core files.
5588 Attaching to processes now works again; thanks for the many bug reports.
5590 We have also stomped on a bunch of core dumps caused by
5591 printf_filtered("%s") problems.
5593 We eliminated a copyright problem on the rpc and ptrace header files
5594 for VxWorks, which was discovered at the last minute during the 4.7
5595 release. You should now be able to build a VxWorks GDB.
5597 You can now interrupt gdb while an attached process is running. This
5598 will cause the attached process to stop, and give control back to GDB.
5600 We fixed problems caused by using too many file descriptors
5601 for reading symbols from object files and libraries. This was
5602 especially a problem for programs that used many (~100) shared
5605 The `step' command now only enters a subroutine if there is line number
5606 information for the subroutine. Otherwise it acts like the `next'
5607 command. Previously, `step' would enter subroutines if there was
5608 any debugging information about the routine. This avoids problems
5609 when using `cc -g1' on MIPS machines.
5611 * Internal improvements
5613 GDB's internal interfaces have been improved to make it easier to support
5614 debugging of multiple languages in the future.
5616 GDB now uses a common structure for symbol information internally.
5617 Minimal symbols (derived from linkage symbols in object files), partial
5618 symbols (from a quick scan of debug information), and full symbols
5619 contain a common subset of information, making it easier to write
5620 shared code that handles any of them.
5622 * New command line options
5624 We now accept --silent as an alias for --quiet.
5628 The memory-mapped-malloc library is now licensed under the GNU Library
5629 General Public License.
5631 *** Changes in GDB-4.7:
5633 * Host/native/target split
5635 GDB has had some major internal surgery to untangle the support for
5636 hosts and remote targets. Now, when you configure GDB for a remote
5637 target, it will no longer load in all of the support for debugging
5638 local programs on the host. When fully completed and tested, this will
5639 ensure that arbitrary host/target combinations are possible.
5641 The primary conceptual shift is to separate the non-portable code in
5642 GDB into three categories. Host specific code is required any time GDB
5643 is compiled on that host, regardless of the target. Target specific
5644 code relates to the peculiarities of the target, but can be compiled on
5645 any host. Native specific code is everything else: it can only be
5646 built when the host and target are the same system. Child process
5647 handling and core file support are two common `native' examples.
5649 GDB's use of /proc for controlling Unix child processes is now cleaner.
5650 It has been split out into a single module under the `target_ops' vector,
5651 plus two native-dependent functions for each system that uses /proc.
5653 * New hosts supported
5655 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5656 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5657 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5659 * New targets supported
5661 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5662 68030 and CPU32 m68030-*-*, m68332-*-*
5664 * New native hosts supported
5666 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5667 (386bsd is not well tested yet)
5668 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5670 * New file formats supported
5672 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5673 supports reading of `a.out.adobe' object files, which are an a.out
5674 format extended with minimal information about multiple sections.
5678 `show copying' is the same as the old `info copying'.
5679 `show warranty' is the same as `info warrantee'.
5680 These were renamed for consistency. The old commands continue to work.
5682 `info handle' is a new alias for `info signals'.
5684 You can now define pre-command hooks, which attach arbitrary command
5685 scripts to any command. The commands in the hook will be executed
5686 prior to the user's command. You can also create a hook which will be
5687 executed whenever the program stops. See gdb.texinfo.
5691 We now deal with Cfront style name mangling, and can even extract type
5692 info from mangled symbols. GDB can automatically figure out which
5693 symbol mangling style your C++ compiler uses.
5695 Calling of methods and virtual functions has been improved as well.
5699 The crash that occured when debugging Sun Ansi-C compiled binaries is
5700 fixed. This was due to mishandling of the extra N_SO stabs output
5703 We also finally got Ultrix 4.2 running in house, and fixed core file
5704 support, with help from a dozen people on the net.
5706 John M. Farrell discovered that the reason that single-stepping was so
5707 slow on all of the Mips based platforms (primarily SGI and DEC) was
5708 that we were trying to demangle and lookup a symbol used for internal
5709 purposes on every instruction that was being stepped through. Changing
5710 the name of that symbol so that it couldn't be mistaken for a C++
5711 mangled symbol sped things up a great deal.
5713 Rich Pixley sped up symbol lookups in general by getting much smarter
5714 about when C++ symbol mangling is necessary. This should make symbol
5715 completion (TAB on the command line) much faster. It's not as fast as
5716 we'd like, but it's significantly faster than gdb-4.6.
5720 A new user controllable variable 'call_scratch_address' can
5721 specify the location of a scratch area to be used when GDB
5722 calls a function in the target. This is necessary because the
5723 usual method of putting the scratch area on the stack does not work
5724 in systems that have separate instruction and data spaces.
5726 We integrated changes to support the 29k UDI (Universal Debugger
5727 Interface), but discovered at the last minute that we didn't have all
5728 of the appropriate copyright paperwork. We are working with AMD to
5729 resolve this, and hope to have it available soon.
5733 We have sped up the remote serial line protocol, especially for targets
5734 with lots of registers. It now supports a new `expedited status' ('T')
5735 message which can be used in place of the existing 'S' status message.
5736 This allows the remote stub to send only the registers that GDB
5737 needs to make a quick decision about single-stepping or conditional
5738 breakpoints, eliminating the need to fetch the entire register set for
5739 each instruction being stepped through.
5741 The GDB remote serial protocol now implements a write-through cache for
5742 registers, only re-reading the registers if the target has run.
5744 There is also a new remote serial stub for SPARC processors. You can
5745 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5746 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5747 processor with a serial port.
5751 Configure.in files have become much easier to read and modify. A new
5752 `table driven' format makes it more obvious what configurations are
5753 supported, and what files each one uses.
5757 There is a new opcodes library which will eventually contain all of the
5758 disassembly routines and opcode tables. At present, it only contains
5759 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5760 disassembler (binutils/objdump) to share these routines.
5762 The libiberty library is now copylefted under the GNU Library General
5763 Public License. This allows more liberal use, and was done so libg++
5764 can use it. This makes no difference to GDB, since the Library License
5765 grants all the rights from the General Public License.
5769 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5770 reference to the stabs symbol info used by the debugger. It is (as far
5771 as we know) the only published document on this fascinating topic. We
5772 encourage you to read it, compare it to the stabs information on your
5773 system, and send improvements on the document in general (to
5774 bug-gdb@prep.ai.mit.edu).
5776 And, of course, many bugs have been fixed.
5779 *** Changes in GDB-4.6:
5781 * Better support for C++ function names
5783 GDB now accepts as input the "demangled form" of C++ overloaded function
5784 names and member function names, and can do command completion on such names
5785 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5786 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5787 Make use of command completion, it is your friend.
5789 GDB also now accepts a variety of C++ mangled symbol formats. They are
5790 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5791 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5792 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5793 for the list of formats.
5795 * G++ symbol mangling problem
5797 Recent versions of gcc have a bug in how they emit debugging information for
5798 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5799 directory) can be applied to gcc to fix the problem. Alternatively, if you
5800 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5801 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5802 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5805 * New 'maintenance' command
5807 All of the commands related to hacking GDB internals have been moved out of
5808 the main command set, and now live behind the 'maintenance' command. This
5809 can also be abbreviated as 'mt'. The following changes were made:
5811 dump-me -> maintenance dump-me
5812 info all-breakpoints -> maintenance info breakpoints
5813 printmsyms -> maintenance print msyms
5814 printobjfiles -> maintenance print objfiles
5815 printpsyms -> maintenance print psymbols
5816 printsyms -> maintenance print symbols
5818 The following commands are new:
5820 maintenance demangle Call internal GDB demangler routine to
5821 demangle a C++ link name and prints the result.
5822 maintenance print type Print a type chain for a given symbol
5824 * Change to .gdbinit file processing
5826 We now read the $HOME/.gdbinit file before processing the argv arguments
5827 (e.g. reading symbol files or core files). This allows global parameters to
5828 be set, which will apply during the symbol reading. The ./.gdbinit is still
5829 read after argv processing.
5831 * New hosts supported
5833 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5835 GNU/Linux support i386-unknown-linux or linux
5837 We are also including code to support the HP/PA running BSD and HPUX. This
5838 is almost guaranteed not to work, as we didn't have time to test or build it
5839 for this release. We are including it so that the more adventurous (or
5840 masochistic) of you can play with it. We also had major problems with the
5841 fact that the compiler that we got from HP doesn't support the -g option.
5844 * New targets supported
5846 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5848 * More smarts about finding #include files
5850 GDB now remembers the compilation directory for all include files, and for
5851 all files from which C is generated (like yacc and lex sources). This
5852 greatly improves GDB's ability to find yacc/lex sources, and include files,
5853 especially if you are debugging your program from a directory different from
5854 the one that contains your sources.
5856 We also fixed a bug which caused difficulty with listing and setting
5857 breakpoints in include files which contain C code. (In the past, you had to
5858 try twice in order to list an include file that you hadn't looked at before.)
5860 * Interesting infernals change
5862 GDB now deals with arbitrary numbers of sections, where the symbols for each
5863 section must be relocated relative to that section's landing place in the
5864 target's address space. This work was needed to support ELF with embedded
5865 stabs used by Solaris-2.0.
5867 * Bug fixes (of course!)
5869 There have been loads of fixes for the following things:
5870 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5871 i960, stabs, DOS(GO32), procfs, etc...
5873 See the ChangeLog for details.
5875 *** Changes in GDB-4.5:
5877 * New machines supported (host and target)
5879 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5881 SGI Irix-4.x mips-sgi-irix4 or iris4
5883 * New malloc package
5885 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5886 Mmalloc is capable of handling mutiple heaps of memory. It is also
5887 capable of saving a heap to a file, and then mapping it back in later.
5888 This can be used to greatly speedup the startup of GDB by using a
5889 pre-parsed symbol table which lives in a mmalloc managed heap. For
5890 more details, please read mmalloc/mmalloc.texi.
5894 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5895 'help info proc' for details.
5897 * MIPS ecoff symbol table format
5899 The code that reads MIPS symbol table format is now supported on all hosts.
5900 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5903 * File name changes for MS-DOS
5905 Many files in the config directories have been renamed to make it easier to
5906 support GDB on MS-DOSe systems (which have very restrictive file name
5907 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5908 environment) is close to working but has some remaining problems. Note
5909 that debugging of DOS programs is not supported, due to limitations
5910 in the ``operating system'', but it can be used to host cross-debugging.
5912 * Cross byte order fixes
5914 Many fixes have been made to support cross debugging of Sparc and MIPS
5915 targets from hosts whose byte order differs.
5917 * New -mapped and -readnow options
5919 If memory-mapped files are available on your system through the 'mmap'
5920 system call, you can use the -mapped option on the `file' or
5921 `symbol-file' commands to cause GDB to write the symbols from your
5922 program into a reusable file. If the program you are debugging is
5923 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5924 Future GDB debugging sessions will notice the presence of this file,
5925 and will quickly map in symbol information from it, rather than reading
5926 the symbol table from the executable program. Using the '-mapped'
5927 option in a GDB `file' or `symbol-file' command has the same effect as
5928 starting GDB with the '-mapped' command-line option.
5930 You can cause GDB to read the entire symbol table immediately by using
5931 the '-readnow' option with any of the commands that load symbol table
5932 information (or on the GDB command line). This makes the command
5933 slower, but makes future operations faster.
5935 The -mapped and -readnow options are typically combined in order to
5936 build a `fred.syms' file that contains complete symbol information.
5937 A simple GDB invocation to do nothing but build a `.syms' file for future
5940 gdb -batch -nx -mapped -readnow programname
5942 The `.syms' file is specific to the host machine on which GDB is run.
5943 It holds an exact image of GDB's internal symbol table. It cannot be
5944 shared across multiple host platforms.
5946 * longjmp() handling
5948 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5949 siglongjmp() without losing control. This feature has not yet been ported to
5950 all systems. It currently works on many 386 platforms, all MIPS-based
5951 platforms (SGI, DECstation, etc), and Sun3/4.
5955 Preliminary work has been put in to support the new Solaris OS from Sun. At
5956 this time, it can control and debug processes, but it is not capable of
5961 As always, many many bug fixes. The major areas were with g++, and mipsread.
5962 People using the MIPS-based platforms should experience fewer mysterious
5963 crashes and trashed symbol tables.
5965 *** Changes in GDB-4.4:
5967 * New machines supported (host and target)
5969 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5971 BSD Reno on Vax vax-dec-bsd
5972 Ultrix on Vax vax-dec-ultrix
5974 * New machines supported (target)
5976 AMD 29000 embedded, using EBMON a29k-none-none
5980 GDB continues to improve its handling of C++. `References' work better.
5981 The demangler has also been improved, and now deals with symbols mangled as
5982 per the Annotated C++ Reference Guide.
5984 GDB also now handles `stabs' symbol information embedded in MIPS
5985 `ecoff' symbol tables. Since the ecoff format was not easily
5986 extensible to handle new languages such as C++, this appeared to be a
5987 good way to put C++ debugging info into MIPS binaries. This option
5988 will be supported in the GNU C compiler, version 2, when it is
5991 * New features for SVR4
5993 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5994 shared libraries. Debugging dynamically linked programs should present
5995 only minor differences from debugging statically linked programs.
5997 The `info proc' command will print out information about any process
5998 on an SVR4 system (including the one you are debugging). At the moment,
5999 it prints the address mappings of the process.
6001 If you bring up GDB on another SVR4 system, please send mail to
6002 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6004 * Better dynamic linking support in SunOS
6006 Reading symbols from shared libraries which contain debugging symbols
6007 now works properly. However, there remain issues such as automatic
6008 skipping of `transfer vector' code during function calls, which
6009 make it harder to debug code in a shared library, than to debug the
6010 same code linked statically.
6014 GDB is now using the latest `getopt' routines from the FSF. This
6015 version accepts the -- prefix for options with long names. GDB will
6016 continue to accept the old forms (-option and +option) as well.
6017 Various single letter abbreviations for options have been explicity
6018 added to the option table so that they won't get overshadowed in the
6019 future by other options that begin with the same letter.
6023 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6024 Many assorted bugs have been handled. Many more remain to be handled.
6025 See the various ChangeLog files (primarily in gdb and bfd) for details.
6028 *** Changes in GDB-4.3:
6030 * New machines supported (host and target)
6032 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6033 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6034 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6036 * Almost SCO Unix support
6038 We had hoped to support:
6039 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6040 (except for core file support), but we discovered very late in the release
6041 that it has problems with process groups that render gdb unusable. Sorry
6042 about that. I encourage people to fix it and post the fixes.
6044 * Preliminary ELF and DWARF support
6046 GDB can read ELF object files on System V Release 4, and can handle
6047 debugging records for C, in DWARF format, in ELF files. This support
6048 is preliminary. If you bring up GDB on another SVR4 system, please
6049 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6054 GDB now uses the latest `readline' library. One user-visible change
6055 is that two tabs will list possible command completions, which previously
6056 required typing M-? (meta-question mark, or ESC ?).
6060 The `stepi' bug that many of you noticed has been squashed.
6061 Many bugs in C++ have been handled. Many more remain to be handled.
6062 See the various ChangeLog files (primarily in gdb and bfd) for details.
6064 * State of the MIPS world (in case you wondered):
6066 GDB can understand the symbol tables emitted by the compilers
6067 supplied by most vendors of MIPS-based machines, including DEC. These
6068 symbol tables are in a format that essentially nobody else uses.
6070 Some versions of gcc come with an assembler post-processor called
6071 mips-tfile. This program is required if you want to do source-level
6072 debugging of gcc-compiled programs. I believe FSF does not ship
6073 mips-tfile with gcc version 1, but it will eventually come with gcc
6076 Debugging of g++ output remains a problem. g++ version 1.xx does not
6077 really support it at all. (If you're lucky, you should be able to get
6078 line numbers and stack traces to work, but no parameters or local
6079 variables.) With some work it should be possible to improve the
6082 When gcc version 2 is released, you will have somewhat better luck.
6083 However, even then you will get confusing results for inheritance and
6086 We will eventually provide full debugging of g++ output on
6087 DECstations. This will probably involve some kind of stabs-in-ecoff
6088 encapulation, but the details have not been worked out yet.
6091 *** Changes in GDB-4.2:
6093 * Improved configuration
6095 Only one copy of `configure' exists now, and it is not self-modifying.
6096 Porting BFD is simpler.
6100 The `step' and `next' commands now only stop at the first instruction
6101 of a source line. This prevents the multiple stops that used to occur
6102 in switch statements, for-loops, etc. `Step' continues to stop if a
6103 function that has debugging information is called within the line.
6107 Lots of small bugs fixed. More remain.
6109 * New host supported (not target)
6111 Intel 386 PC clone running Mach i386-none-mach
6114 *** Changes in GDB-4.1:
6116 * Multiple source language support
6118 GDB now has internal scaffolding to handle several source languages.
6119 It determines the type of each source file from its filename extension,
6120 and will switch expression parsing and number formatting to match the
6121 language of the function in the currently selected stack frame.
6122 You can also specifically set the language to be used, with
6123 `set language c' or `set language modula-2'.
6127 GDB now has preliminary support for the GNU Modula-2 compiler,
6128 currently under development at the State University of New York at
6129 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6130 continue through the fall of 1991 and into 1992.
6132 Other Modula-2 compilers are currently not supported, and attempting to
6133 debug programs compiled with them will likely result in an error as the
6134 symbol table is read. Feel free to work on it, though!
6136 There are hooks in GDB for strict type checking and range checking,
6137 in the `Modula-2 philosophy', but they do not currently work.
6141 GDB can now write to executable and core files (e.g. patch
6142 a variable's value). You must turn this switch on, specify
6143 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6144 by assigning a new value to a variable. Modifications take
6147 * Automatic SunOS shared library reading
6149 When you run your program, GDB automatically determines where its
6150 shared libraries (if any) have been loaded, and reads their symbols.
6151 The `share' command is no longer needed. This also works when
6152 examining core files.
6156 You can specify the number of lines that the `list' command shows.
6159 * New machines supported (host and target)
6161 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6162 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6163 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6165 * New hosts supported (not targets)
6167 IBM RT/PC: romp-ibm-aix or rtpc
6169 * New targets supported (not hosts)
6171 AMD 29000 embedded with COFF a29k-none-coff
6172 AMD 29000 embedded with a.out a29k-none-aout
6173 Ultracomputer remote kernel debug a29k-nyu-kern
6175 * New remote interfaces
6181 *** Changes in GDB-4.0:
6185 Wide output is wrapped at good places to make the output more readable.
6187 Gdb now supports cross-debugging from a host machine of one type to a
6188 target machine of another type. Communication with the target system
6189 is over serial lines. The ``target'' command handles connecting to the
6190 remote system; the ``load'' command will download a program into the
6191 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6192 also supports debugging of realtime processes running under VxWorks,
6193 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6194 stub on the target system.
6196 New CPUs supported include the AMD 29000 and Intel 960.
6198 GDB now reads object files and symbol tables via a ``binary file''
6199 library, which allows a single copy of GDB to debug programs of multiple
6200 object file types such as a.out and coff.
6202 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6203 refcard.dvi and refcard.ps are available to format it).
6206 * Control-Variable user interface simplified
6208 All variables that control the operation of the debugger can be set
6209 by the ``set'' command, and displayed by the ``show'' command.
6211 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6212 ``Show prompt'' produces the response:
6213 Gdb's prompt is new-gdb=>.
6215 What follows are the NEW set commands. The command ``help set'' will
6216 print a complete list of old and new set commands. ``help set FOO''
6217 will give a longer description of the variable FOO. ``show'' will show
6218 all of the variable descriptions and their current settings.
6220 confirm on/off: Enables warning questions for operations that are
6221 hard to recover from, e.g. rerunning the program while
6222 it is already running. Default is ON.
6224 editing on/off: Enables EMACS style command line editing
6225 of input. Previous lines can be recalled with
6226 control-P, the current line can be edited with control-B,
6227 you can search for commands with control-R, etc.
6230 history filename NAME: NAME is where the gdb command history
6231 will be stored. The default is .gdb_history,
6232 or the value of the environment variable
6235 history size N: The size, in commands, of the command history. The
6236 default is 256, or the value of the environment variable
6239 history save on/off: If this value is set to ON, the history file will
6240 be saved after exiting gdb. If set to OFF, the
6241 file will not be saved. The default is OFF.
6243 history expansion on/off: If this value is set to ON, then csh-like
6244 history expansion will be performed on
6245 command line input. The default is OFF.
6247 radix N: Sets the default radix for input and output. It can be set
6248 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6249 in the current radix, so "set radix 10" is always a no-op.
6251 height N: This integer value is the number of lines on a page. Default
6252 is 24, the current `stty rows'' setting, or the ``li#''
6253 setting from the termcap entry matching the environment
6256 width N: This integer value is the number of characters on a line.
6257 Default is 80, the current `stty cols'' setting, or the ``co#''
6258 setting from the termcap entry matching the environment
6261 Note: ``set screensize'' is obsolete. Use ``set height'' and
6262 ``set width'' instead.
6264 print address on/off: Print memory addresses in various command displays,
6265 such as stack traces and structure values. Gdb looks
6266 more ``symbolic'' if you turn this off; it looks more
6267 ``machine level'' with it on. Default is ON.
6269 print array on/off: Prettyprint arrays. New convenient format! Default
6272 print demangle on/off: Print C++ symbols in "source" form if on,
6275 print asm-demangle on/off: Same, for assembler level printouts
6278 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6281 * Support for Epoch Environment.
6283 The epoch environment is a version of Emacs v18 with windowing. One
6284 new command, ``inspect'', is identical to ``print'', except that if you
6285 are running in the epoch environment, the value is printed in its own
6289 * Support for Shared Libraries
6291 GDB can now debug programs and core files that use SunOS shared libraries.
6292 Symbols from a shared library cannot be referenced
6293 before the shared library has been linked with the program (this
6294 happens after you type ``run'' and before the function main() is entered).
6295 At any time after this linking (including when examining core files
6296 from dynamically linked programs), gdb reads the symbols from each
6297 shared library when you type the ``sharedlibrary'' command.
6298 It can be abbreviated ``share''.
6300 sharedlibrary REGEXP: Load shared object library symbols for files
6301 matching a unix regular expression. No argument
6302 indicates to load symbols for all shared libraries.
6304 info sharedlibrary: Status of loaded shared libraries.
6309 A watchpoint stops execution of a program whenever the value of an
6310 expression changes. Checking for this slows down execution
6311 tremendously whenever you are in the scope of the expression, but is
6312 quite useful for catching tough ``bit-spreader'' or pointer misuse
6313 problems. Some machines such as the 386 have hardware for doing this
6314 more quickly, and future versions of gdb will use this hardware.
6316 watch EXP: Set a watchpoint (breakpoint) for an expression.
6318 info watchpoints: Information about your watchpoints.
6320 delete N: Deletes watchpoint number N (same as breakpoints).
6321 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6322 enable N: Re-enables watchpoint number N (same as breakpoints).
6325 * C++ multiple inheritance
6327 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6330 * C++ exception handling
6332 Gdb now supports limited C++ exception handling. Besides the existing
6333 ability to breakpoint on an exception handler, gdb can breakpoint on
6334 the raising of an exception (before the stack is peeled back to the
6337 catch FOO: If there is a FOO exception handler in the dynamic scope,
6338 set a breakpoint to catch exceptions which may be raised there.
6339 Multiple exceptions (``catch foo bar baz'') may be caught.
6341 info catch: Lists all exceptions which may be caught in the
6342 current stack frame.
6345 * Minor command changes
6347 The command ``call func (arg, arg, ...)'' now acts like the print
6348 command, except it does not print or save a value if the function's result
6349 is void. This is similar to dbx usage.
6351 The ``up'' and ``down'' commands now always print the frame they end up
6352 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6353 frames without printing.
6355 * New directory command
6357 'dir' now adds directories to the FRONT of the source search path.
6358 The path starts off empty. Source files that contain debug information
6359 about the directory in which they were compiled can be found even
6360 with an empty path; Sun CC and GCC include this information. If GDB can't
6361 find your source file in the current directory, type "dir .".
6363 * Configuring GDB for compilation
6365 For normal use, type ``./configure host''. See README or gdb.texinfo
6368 GDB now handles cross debugging. If you are remotely debugging between
6369 two different machines, type ``./configure host -target=targ''.
6370 Host is the machine where GDB will run; targ is the machine
6371 where the program that you are debugging will run.