1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.10
6 * Record btrace now supports non-stop mode.
8 * Support for tracepoints on aarch64-linux was added in GDBserver.
10 * The 'record instruction-history' command now indicates speculative execution
11 when using the Intel(R) Processor Trace recording format.
13 * GDB now allows users to specify explicit locations, bypassing
14 the linespec parser. This feature is also available to GDB/MI
17 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
18 GDB now is able to debug both AArch64 applications and ARM applications
21 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
22 including JIT compiling fast tracepoint's conditional expression bytecode
25 * GDB now supports displaced stepping on AArch64 GNU/Linux.
27 * "info threads", "info inferiors", "info display", "info checkpoints"
28 and "maint info program-spaces" now list the corresponding items in
29 ascending ID order, for consistency with all other "info" commands.
33 maint set target-non-stop (on|off|auto)
34 maint show target-non-stop
35 Control whether GDB targets always operate in non-stop mode even if
36 "set non-stop" is "off". The default is "auto", meaning non-stop
37 mode is enabled if supported by the target.
40 maint show bfd-sharing
41 Control the reuse of bfd objects.
45 Control display of debugging info regarding bfd caching.
47 set remote multiprocess-extensions-packet
48 show remote multiprocess-extensions-packet
49 Set/show the use of the remote protocol multiprocess extensions.
51 set remote thread-events
52 show remote thread-events
53 Set/show the use of thread create/exit events.
55 * The "disassemble" command accepts a new modifier: /s.
56 It prints mixed source+disassembly like /m with two differences:
57 - disassembled instructions are now printed in program order, and
58 - and source for all relevant files is now printed.
59 The "/m" option is now considered deprecated: its "source-centric"
60 output hasn't proved useful in practice.
62 * The "record instruction-history" command accepts a new modifier: /s.
63 It behaves exactly like /m and prints mixed source+disassembly.
65 * The "set scheduler-locking" command supports a new mode "replay".
66 It behaves like "off" in record mode and like "on" in replay mode.
68 * Support for various ROM monitors has been removed:
70 target dbug dBUG ROM monitor for Motorola ColdFire
71 target picobug Motorola picobug monitor
72 target dink32 DINK32 ROM monitor for PowerPC
73 target m32r Renesas M32R/D ROM monitor
74 target mon2000 mon2000 ROM monitor
75 target ppcbug PPCBUG ROM monitor for PowerPC
77 * Support for reading/writing memory and extracting values on architectures
78 whose memory is addressable in units of any integral multiple of 8 bits.
83 Indicates that an exec system call was executed.
85 exec-events feature in qSupported
86 The qSupported packet allows GDB to request support for exec
87 events using the new 'gdbfeature' exec-event, and the qSupported
88 response can contain the corresponding 'stubfeature'. Set and
89 show commands can be used to display whether these features are enabled.
92 Equivalent to interrupting with the ^C character, but works in
95 thread created stop reason (T05 create:...)
96 Indicates that the thread was just created and is stopped at entry.
98 thread exit stop reply (w exitcode;tid)
99 Indicates that the thread has terminated.
102 Enables/disables thread create and exit event reporting. For
103 example, this is used in non-stop mode when GDB stops a set of
104 threads and synchronously waits for the their corresponding stop
105 replies. Without exit events, if one of the threads exits, GDB
106 would hang forever not knowing that it should no longer expect a
107 stop for that same thread.
111 Indicates that there are no resumed threads left in the target (all
112 threads are stopped). The remote stub reports support for this stop
113 reply to GDB's qSupported query.
115 * Extended-remote exec events
117 ** GDB now has support for exec events on extended-remote Linux targets.
118 For such targets with Linux kernels 2.5.46 and later, this enables
119 follow-exec-mode and exec catchpoints.
121 set remote exec-event-feature-packet
122 show remote exec-event-feature-packet
123 Set/show the use of the remote exec event feature.
125 * Thread names in remote protocol
127 The reply to qXfer:threads:read may now include a name attribute for each
130 *** Changes in GDB 7.10
132 * Support for process record-replay and reverse debugging on aarch64*-linux*
133 targets has been added. GDB now supports recording of A64 instruction set
134 including advance SIMD instructions.
136 * Support for Sun's version of the "stabs" debug file format has been removed.
138 * GDB now honors the content of the file /proc/PID/coredump_filter
139 (PID is the process ID) on GNU/Linux systems. This file can be used
140 to specify the types of memory mappings that will be included in a
141 corefile. For more information, please refer to the manual page of
142 "core(5)". GDB also has a new command: "set use-coredump-filter
143 on|off". It allows to set whether GDB will read the content of the
144 /proc/PID/coredump_filter file when generating a corefile.
146 * The "info os" command on GNU/Linux can now display information on
148 "info os cpus" Listing of all cpus/cores on the system
150 * GDB has two new commands: "set serial parity odd|even|none" and
151 "show serial parity". These allows to set or show parity for the
154 * The "info source" command now displays the producer string if it was
155 present in the debug info. This typically includes the compiler version
156 and may include things like its command line arguments.
158 * The "info dll", an alias of the "info sharedlibrary" command,
159 is now available on all platforms.
161 * Directory names supplied to the "set sysroot" commands may be
162 prefixed with "target:" to tell GDB to access shared libraries from
163 the target system, be it local or remote. This replaces the prefix
164 "remote:". The default sysroot has been changed from "" to
165 "target:". "remote:" is automatically converted to "target:" for
166 backward compatibility.
168 * The system root specified by "set sysroot" will be prepended to the
169 filename of the main executable (if reported to GDB as absolute by
170 the operating system) when starting processes remotely, and when
171 attaching to already-running local or remote processes.
173 * GDB now supports automatic location and retrieval of executable
174 files from remote targets. Remote debugging can now be initiated
175 using only a "target remote" or "target extended-remote" command
176 (no "set sysroot" or "file" commands are required). See "New remote
179 * The "dump" command now supports verilog hex format.
181 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
183 * On GNU/Linux, GDB and gdbserver are now able to access executable
184 and shared library files without a "set sysroot" command when
185 attaching to processes running in different mount namespaces from
186 the debugger. This makes it possible to attach to processes in
187 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
188 See "New remote packets" below.
190 * The "tui reg" command now provides completion for all of the
191 available register groups, including target specific groups.
193 * The HISTSIZE environment variable is no longer read when determining
194 the size of GDB's command history. GDB now instead reads the dedicated
195 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
196 disables truncation of command history. Non-numeric values of GDBHISTSIZE
201 ** Memory ports can now be unbuffered.
205 ** gdb.Objfile objects have a new attribute "username",
206 which is the name of the objfile as specified by the user,
207 without, for example, resolving symlinks.
208 ** You can now write frame unwinders in Python.
209 ** gdb.Type objects have a new method "optimized_out",
210 returning optimized out gdb.Value instance of this type.
211 ** gdb.Value objects have new methods "reference_value" and
212 "const_value" which return a reference to the value and a
213 "const" version of the value respectively.
217 maint print symbol-cache
218 Print the contents of the symbol cache.
220 maint print symbol-cache-statistics
221 Print statistics of symbol cache usage.
223 maint flush-symbol-cache
224 Flush the contents of the symbol cache.
228 Start branch trace recording using Branch Trace Store (BTS) format.
231 Evaluate expression by using the compiler and print result.
235 Explicit commands for enabling and disabling tui mode.
238 set mpx bound on i386 and amd64
239 Support for bound table investigation on Intel(R) MPX enabled applications.
243 Start branch trace recording using Intel(R) Processor Trace format.
246 Print information about branch tracing internals.
248 maint btrace packet-history
249 Print the raw branch tracing data.
251 maint btrace clear-packet-history
252 Discard the stored raw branch tracing data.
255 Discard all branch tracing data. It will be fetched and processed
256 anew by the next "record" command.
261 Renamed from "set debug dwarf2-die".
263 Renamed from "show debug dwarf2-die".
266 Renamed from "set debug dwarf2-read".
267 show debug dwarf-read
268 Renamed from "show debug dwarf2-read".
270 maint set dwarf always-disassemble
271 Renamed from "maint set dwarf2 always-disassemble".
272 maint show dwarf always-disassemble
273 Renamed from "maint show dwarf2 always-disassemble".
275 maint set dwarf max-cache-age
276 Renamed from "maint set dwarf2 max-cache-age".
277 maint show dwarf max-cache-age
278 Renamed from "maint show dwarf2 max-cache-age".
281 show debug dwarf-line
282 Control display of debugging info regarding DWARF line processing.
286 Set the maximum number of candidates to be considered during
287 completion. The default value is 200. This limit allows GDB
288 to avoid generating large completion lists, the computation of
289 which can cause the debugger to become temporarily unresponsive.
291 set history remove-duplicates
292 show history remove-duplicates
293 Control the removal of duplicate history entries.
295 maint set symbol-cache-size
296 maint show symbol-cache-size
297 Control the size of the symbol cache.
299 set|show record btrace bts buffer-size
300 Set and show the size of the ring buffer used for branch tracing in
302 The obtained size may differ from the requested size. Use "info
303 record" to see the obtained buffer size.
305 set debug linux-namespaces
306 show debug linux-namespaces
307 Control display of debugging info regarding Linux namespaces.
309 set|show record btrace pt buffer-size
310 Set and show the size of the ring buffer used for branch tracing in
311 Intel(R) Processor Trace format.
312 The obtained size may differ from the requested size. Use "info
313 record" to see the obtained buffer size.
315 maint set|show btrace pt skip-pad
316 Set and show whether PAD packets are skipped when computing the
319 * The command 'thread apply all' can now support new option '-ascending'
320 to call its specified command for all threads in ascending order.
322 * Python/Guile scripting
324 ** GDB now supports auto-loading of Python/Guile scripts contained in the
325 special section named `.debug_gdb_scripts'.
329 qXfer:btrace-conf:read
330 Return the branch trace configuration for the current thread.
332 Qbtrace-conf:bts:size
333 Set the requested ring buffer size for branch tracing in BTS format.
336 Enable Intel(R) Procesor Trace-based branch tracing for the current
337 process. The remote stub reports support for this packet to GDB's
341 Set the requested ring buffer size for branch tracing in Intel(R) Processor
345 Indicates a memory breakpoint instruction was executed, irrespective
346 of whether it was GDB that planted the breakpoint or the breakpoint
347 is hardcoded in the program. This is required for correct non-stop
351 Indicates the target stopped for a hardware breakpoint. This is
352 required for correct non-stop mode operation.
355 Return information about files on the remote system.
358 Return the full absolute name of the file that was executed to
359 create a process running on the remote system.
362 Select the filesystem on which vFile: operations with filename
363 arguments will operate. This is required for GDB to be able to
364 access files on remote targets where the remote stub does not
365 share a common filesystem with the inferior(s).
368 Indicates that a fork system call was executed.
371 Indicates that a vfork system call was executed.
373 vforkdone stop reason
374 Indicates that a vfork child of the specified process has executed
375 an exec or exit, allowing the vfork parent to resume execution.
377 fork-events and vfork-events features in qSupported
378 The qSupported packet allows GDB to request support for fork and
379 vfork events using new 'gdbfeatures' fork-events and vfork-events,
380 and the qSupported response can contain the corresponding
381 'stubfeatures'. Set and show commands can be used to display
382 whether these features are enabled.
384 * Extended-remote fork events
386 ** GDB now has support for fork events on extended-remote Linux
387 targets. For targets with Linux kernels 2.5.60 and later, this
388 enables follow-fork-mode and detach-on-fork for both fork and
389 vfork, as well as fork and vfork catchpoints.
391 * The info record command now shows the recording format and the
392 branch tracing configuration for the current thread when using
393 the btrace record target.
394 For the BTS format, it shows the ring buffer size.
396 * GDB now has support for DTrace USDT (Userland Static Defined
397 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
399 * GDB now supports access to vector registers on S/390 GNU/Linux
402 * Removed command line options
404 -xdb HP-UX XDB compatibility mode.
406 * Removed targets and native configurations
408 HP/PA running HP-UX hppa*-*-hpux*
409 Itanium running HP-UX ia64-*-hpux*
411 * New configure options
414 This configure option allows the user to build GDB with support for
415 Intel(R) Processor Trace (default: auto). This requires libipt.
417 --with-libipt-prefix=PATH
418 Specify the path to the version of libipt that GDB should use.
419 $PATH/include should contain the intel-pt.h header and
420 $PATH/lib should contain the libipt.so library.
422 *** Changes in GDB 7.9.1
426 ** Xmethods can now specify a result type.
428 *** Changes in GDB 7.9
430 * GDB now supports hardware watchpoints on x86 GNU Hurd.
434 ** You can now access frame registers from Python scripts.
435 ** New attribute 'producer' for gdb.Symtab objects.
436 ** gdb.Objfile objects have a new attribute "progspace",
437 which is the gdb.Progspace object of the containing program space.
438 ** gdb.Objfile objects have a new attribute "owner".
439 ** gdb.Objfile objects have a new attribute "build_id",
440 which is the build ID generated when the file was built.
441 ** gdb.Objfile objects have a new method "add_separate_debug_file".
442 ** A new event "gdb.clear_objfiles" has been added, triggered when
443 selecting a new file to debug.
444 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
445 ** New function gdb.lookup_objfile.
447 New events which are triggered when GDB modifies the state of the
450 ** gdb.events.inferior_call_pre: Function call is about to be made.
451 ** gdb.events.inferior_call_post: Function call has just been made.
452 ** gdb.events.memory_changed: A memory location has been altered.
453 ** gdb.events.register_changed: A register has been altered.
455 * New Python-based convenience functions:
457 ** $_caller_is(name [, number_of_frames])
458 ** $_caller_matches(regexp [, number_of_frames])
459 ** $_any_caller_is(name [, number_of_frames])
460 ** $_any_caller_matches(regexp [, number_of_frames])
462 * GDB now supports the compilation and injection of source code into
463 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
464 to compile the source code to object code, and if successful, inject
465 and execute that code within the current context of the inferior.
466 Currently the C language is supported. The commands used to
467 interface with this new feature are:
469 compile code [-raw|-r] [--] [source code]
470 compile file [-raw|-r] filename
474 demangle [-l language] [--] name
475 Demangle "name" in the specified language, or the current language
476 if elided. This command is renamed from the "maint demangle" command.
477 The latter is kept as a no-op to avoid "maint demangle" being interpreted
478 as "maint demangler-warning".
480 queue-signal signal-name-or-number
481 Queue a signal to be delivered to the thread when it is resumed.
483 add-auto-load-scripts-directory directory
484 Add entries to the list of directories from which to load auto-loaded
487 maint print user-registers
488 List all currently available "user" registers.
490 compile code [-r|-raw] [--] [source code]
491 Compile, inject, and execute in the inferior the executable object
492 code produced by compiling the provided source code.
494 compile file [-r|-raw] filename
495 Compile and inject into the inferior the executable object code
496 produced by compiling the source code stored in the filename
499 * On resume, GDB now always passes the signal the program had stopped
500 for to the thread the signal was sent to, even if the user changed
501 threads before resuming. Previously GDB would often (but not
502 always) deliver the signal to the thread that happens to be current
505 * Conversely, the "signal" command now consistently delivers the
506 requested signal to the current thread. GDB now asks for
507 confirmation if the program had stopped for a signal and the user
508 switched threads meanwhile.
510 * "breakpoint always-inserted" modes "off" and "auto" merged.
512 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
513 won't remove breakpoints from the target until all threads stop,
514 even in non-stop mode. The "auto" mode has been removed, and "off"
515 is now the default mode.
519 set debug symbol-lookup
520 show debug symbol-lookup
521 Control display of debugging info regarding symbol lookup.
525 ** The -list-thread-groups command outputs an exit-code field for
526 inferiors that have exited.
530 MIPS SDE mips*-sde*-elf*
534 Support for these obsolete configurations has been removed.
536 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
537 SGI Irix-5.x mips-*-irix5*
538 SGI Irix-6.x mips-*-irix6*
539 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
540 VAX running Ultrix vax-*-ultrix*
542 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
543 and "assf"), have been removed. Use the "sharedlibrary" command, or
544 its alias "share", instead.
546 *** Changes in GDB 7.8
548 * New command line options
551 This is an alias for the --data-directory option.
553 * GDB supports printing and modifying of variable length automatic arrays
554 as specified in ISO C99.
556 * The ARM simulator now supports instruction level tracing
557 with or without disassembly.
561 GDB now has support for scripting using Guile. Whether this is
562 available is determined at configure time.
563 Guile version 2.0 or greater is required.
564 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
566 * New commands (for set/show, see "New options" below)
570 Invoke CODE by passing it to the Guile interpreter.
574 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
576 info auto-load guile-scripts [regexp]
577 Print the list of automatically loaded Guile scripts.
579 * The source command is now capable of sourcing Guile scripts.
580 This feature is dependent on the debugger being built with Guile support.
584 set print symbol-loading (off|brief|full)
585 show print symbol-loading
586 Control whether to print informational messages when loading symbol
587 information for a file. The default is "full", but when debugging
588 programs with large numbers of shared libraries the amount of output
591 set guile print-stack (none|message|full)
592 show guile print-stack
593 Show a stack trace when an error is encountered in a Guile script.
595 set auto-load guile-scripts (on|off)
596 show auto-load guile-scripts
597 Control auto-loading of Guile script files.
599 maint ada set ignore-descriptive-types (on|off)
600 maint ada show ignore-descriptive-types
601 Control whether the debugger should ignore descriptive types in Ada
602 programs. The default is not to ignore the descriptive types. See
603 the user manual for more details on descriptive types and the intended
604 usage of this option.
606 set auto-connect-native-target
608 Control whether GDB is allowed to automatically connect to the
609 native target for the run, attach, etc. commands when not connected
610 to any target yet. See also "target native" below.
612 set record btrace replay-memory-access (read-only|read-write)
613 show record btrace replay-memory-access
614 Control what memory accesses are allowed during replay.
616 maint set target-async (on|off)
617 maint show target-async
618 This controls whether GDB targets operate in synchronous or
619 asynchronous mode. Normally the default is asynchronous, if it is
620 available; but this can be changed to more easily debug problems
621 occurring only in synchronous mode.
623 set mi-async (on|off)
625 Control whether MI asynchronous mode is preferred. This supersedes
626 "set target-async" of previous GDB versions.
628 * "set target-async" is deprecated as a CLI option and is now an alias
629 for "set mi-async" (only puts MI into async mode).
631 * Background execution commands (e.g., "c&", "s&", etc.) are now
632 possible ``out of the box'' if the target supports them. Previously
633 the user would need to explicitly enable the possibility with the
634 "set target-async on" command.
636 * New features in the GDB remote stub, GDBserver
638 ** New option --debug-format=option1[,option2,...] allows one to add
639 additional text to each output. At present only timestamps
640 are supported: --debug-format=timestamps.
641 Timestamps can also be turned on with the
642 "monitor set debug-format timestamps" command from GDB.
644 * The 'record instruction-history' command now starts counting instructions
645 at one. This also affects the instruction ranges reported by the
646 'record function-call-history' command when given the /i modifier.
648 * The command 'record function-call-history' supports a new modifier '/c' to
649 indent the function names based on their call stack depth.
650 The fields for the '/i' and '/l' modifier have been reordered.
651 The source line range is now prefixed with 'at'.
652 The instruction range is now prefixed with 'inst'.
653 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
654 "record instruction-history" and "list" commands.
656 * The ranges given as arguments to the 'record function-call-history' and
657 'record instruction-history' commands are now inclusive.
659 * The btrace record target now supports the 'record goto' command.
660 For locations inside the execution trace, the back trace is computed
661 based on the information stored in the execution trace.
663 * The btrace record target supports limited reverse execution and replay.
664 The target does not record data and therefore does not allow reading
667 * The "catch syscall" command now works on s390*-linux* targets.
669 * The "compare-sections" command is no longer specific to target
670 remote. It now works with all targets.
672 * All native targets are now consistently called "native".
673 Consequently, the "target child", "target GNU", "target djgpp",
674 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
675 commands have been replaced with "target native". The QNX/NTO port
676 leaves the "procfs" target in place and adds a "native" target for
677 consistency with other ports. The impact on users should be minimal
678 as these commands previously either throwed an error, or were
679 no-ops. The target's name is visible in the output of the following
680 commands: "help target", "info target", "info files", "maint print
683 * The "target native" command now connects to the native target. This
684 can be used to launch native programs even when "set
685 auto-connect-native-target" is set to off.
687 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.
689 * Support for Intel(R) AVX-512 registers on GNU/Linux.
690 Support displaying and modifying Intel(R) AVX-512 registers
691 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
695 qXfer:btrace:read's annex
696 The qXfer:btrace:read packet supports a new annex 'delta' to read
697 branch trace incrementally.
701 ** Valid Python operations on gdb.Value objects representing
702 structs/classes invoke the corresponding overloaded operators if
704 ** New `Xmethods' feature in the Python API. Xmethods are
705 additional methods or replacements for existing methods of a C++
706 class. This feature is useful for those cases where a method
707 defined in C++ source code could be inlined or optimized out by
708 the compiler, making it unavailable to GDB.
711 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
713 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
714 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
715 its alias "share", instead.
717 * The commands "set remotebaud" and "show remotebaud" are no longer
718 supported. Use "set serial baud" and "show serial baud" (respectively)
723 ** A new option "-gdb-set mi-async" replaces "-gdb-set
724 target-async". The latter is left as a deprecated alias of the
725 former for backward compatibility. If the target supports it,
726 CLI background execution commands are now always possible by
727 default, independently of whether the frontend stated a
728 preference for asynchronous execution with "-gdb-set mi-async".
729 Previously "-gdb-set target-async off" affected both MI execution
730 commands and CLI execution commands.
732 *** Changes in GDB 7.7
734 * Improved support for process record-replay and reverse debugging on
735 arm*-linux* targets. Support for thumb32 and syscall instruction
736 recording has been added.
738 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
740 * GDB now supports Fission DWP file format version 2.
741 http://gcc.gnu.org/wiki/DebugFission
743 * New convenience function "$_isvoid", to check whether an expression
744 is void. A void expression is an expression where the type of the
745 result is "void". For example, some convenience variables may be
746 "void" when evaluated (e.g., "$_exitcode" before the execution of
747 the program being debugged; or an undefined convenience variable).
748 Another example, when calling a function whose return type is
751 * The "maintenance print objfiles" command now takes an optional regexp.
753 * The "catch syscall" command now works on arm*-linux* targets.
755 * GDB now consistently shows "<not saved>" when printing values of
756 registers the debug info indicates have not been saved in the frame
757 and there's nowhere to retrieve them from
758 (callee-saved/call-clobbered registers):
763 (gdb) info registers rax
766 Before, the former would print "<optimized out>", and the latter
767 "*value not available*".
769 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
774 ** Frame filters and frame decorators have been added.
775 ** Temporary breakpoints are now supported.
776 ** Line tables representation has been added.
777 ** New attribute 'parent_type' for gdb.Field objects.
778 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
779 ** New attribute 'name' for gdb.Type objects.
783 Nios II ELF nios2*-*-elf
784 Nios II GNU/Linux nios2*-*-linux
785 Texas Instruments MSP430 msp430*-*-elf
787 * Removed native configurations
789 Support for these a.out NetBSD and OpenBSD obsolete configurations has
790 been removed. ELF variants of these configurations are kept supported.
792 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
793 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
794 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
795 i[34567]86-*-openbsd3.[0-3]
796 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
797 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
798 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
802 Like "catch throw", but catches a re-thrown exception.
804 Renamed from old "maint check-symtabs".
806 Perform consistency checks on symtabs.
808 Expand symtabs matching an optional regexp.
811 Display the details of GDB configure-time options.
813 maint set|show per-command
814 maint set|show per-command space
815 maint set|show per-command time
816 maint set|show per-command symtab
817 Enable display of per-command gdb resource usage.
819 remove-symbol-file FILENAME
820 remove-symbol-file -a ADDRESS
821 Remove a symbol file added via add-symbol-file. The file to remove
822 can be identified by its filename or by an address that lies within
823 the boundaries of this symbol file in memory.
826 info exceptions REGEXP
827 Display the list of Ada exceptions defined in the program being
828 debugged. If provided, only the exceptions whose names match REGEXP
833 set debug symfile off|on
835 Control display of debugging info regarding reading symbol files and
836 symbol tables within those files
838 set print raw frame-arguments
839 show print raw frame-arguments
840 Set/show whether to print frame arguments in raw mode,
841 disregarding any defined pretty-printers.
843 set remote trace-status-packet
844 show remote trace-status-packet
845 Set/show the use of remote protocol qTStatus packet.
849 Control display of debugging messages related to Nios II targets.
853 Control whether target-assisted range stepping is enabled.
855 set startup-with-shell
856 show startup-with-shell
857 Specifies whether Unix child processes are started via a shell or
862 Use the target memory cache for accesses to the code segment. This
863 improves performance of remote debugging (particularly disassembly).
865 * You can now use a literal value 'unlimited' for options that
866 interpret 0 or -1 as meaning "unlimited". E.g., "set
867 trace-buffer-size unlimited" is now an alias for "set
868 trace-buffer-size -1" and "set height unlimited" is now an alias for
871 * The "set debug symtab-create" debugging option of GDB has been changed to
872 accept a verbosity level. 0 means "off", 1 provides basic debugging
873 output, and values of 2 or greater provides more verbose output.
875 * New command-line options
877 Display the details of GDB configure-time options.
879 * The command 'tsave' can now support new option '-ctf' to save trace
880 buffer in Common Trace Format.
882 * Newly installed $prefix/bin/gcore acts as a shell interface for the
885 * GDB now implements the the C++ 'typeid' operator.
887 * The new convenience variable $_exception holds the exception being
888 thrown or caught at an exception-related catchpoint.
890 * The exception-related catchpoints, like "catch throw", now accept a
891 regular expression which can be used to filter exceptions by type.
893 * The new convenience variable $_exitsignal is automatically set to
894 the terminating signal number when the program being debugged dies
895 due to an uncaught signal.
899 ** All MI commands now accept an optional "--language" option.
900 Support for this feature can be verified by using the "-list-features"
901 command, which should contain "language-option".
903 ** The new command -info-gdb-mi-command allows the user to determine
904 whether a GDB/MI command is supported or not.
906 ** The "^error" result record returned when trying to execute an undefined
907 GDB/MI command now provides a variable named "code" whose content is the
908 "undefined-command" error code. Support for this feature can be verified
909 by using the "-list-features" command, which should contain
910 "undefined-command-error-code".
912 ** The -trace-save MI command can optionally save trace buffer in Common
915 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
917 ** The command -data-list-register-values now accepts an optional
918 "--skip-unavailable" option. When used, only the available registers
921 ** The new command -trace-frame-collected dumps collected variables,
922 computed expressions, tvars, memory and registers in a traceframe.
924 ** The commands -stack-list-locals, -stack-list-arguments and
925 -stack-list-variables now accept an option "--skip-unavailable".
926 When used, only the available locals or arguments are displayed.
928 ** The -exec-run command now accepts an optional "--start" option.
929 When used, the command follows the same semantics as the "start"
930 command, stopping the program's execution at the start of its
931 main subprogram. Support for this feature can be verified using
932 the "-list-features" command, which should contain
933 "exec-run-start-option".
935 ** The new commands -catch-assert and -catch-exceptions insert
936 catchpoints stopping the program when Ada exceptions are raised.
938 ** The new command -info-ada-exceptions provides the equivalent of
939 the new "info exceptions" command.
941 * New system-wide configuration scripts
942 A GDB installation now provides scripts suitable for use as system-wide
943 configuration scripts for the following systems:
947 * GDB now supports target-assigned range stepping with remote targets.
948 This improves the performance of stepping source lines by reducing
949 the number of control packets from/to GDB. See "New remote packets"
952 * GDB now understands the element 'tvar' in the XML traceframe info.
953 It has the id of the collected trace state variables.
955 * On S/390 targets that provide the transactional-execution feature,
956 the program interruption transaction diagnostic block (TDB) is now
957 represented as a number of additional "registers" in GDB.
963 The vCont packet supports a new 'r' action, that tells the remote
964 stub to step through an address range itself, without GDB
965 involvemement at each single-step.
967 qXfer:libraries-svr4:read's annex
968 The previously unused annex of the qXfer:libraries-svr4:read packet
969 is now used to support passing an argument list. The remote stub
970 reports support for this argument list to GDB's qSupported query.
971 The defined arguments are "start" and "prev", used to reduce work
972 necessary for library list updating, resulting in significant
975 * New features in the GDB remote stub, GDBserver
977 ** GDBserver now supports target-assisted range stepping. Currently
978 enabled on x86/x86_64 GNU/Linux targets.
980 ** GDBserver now adds element 'tvar' in the XML in the reply to
981 'qXfer:traceframe-info:read'. It has the id of the collected
982 trace state variables.
984 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
987 * New 'z' formatter for printing and examining memory, this displays the
988 value as hexadecimal zero padded on the left to the size of the type.
990 * GDB can now use Windows x64 unwinding data.
992 * The "set remotebaud" command has been replaced by "set serial baud".
993 Similarly, "show remotebaud" has been replaced by "show serial baud".
994 The "set remotebaud" and "show remotebaud" commands are still available
995 to provide backward compatibility with older versions of GDB.
997 *** Changes in GDB 7.6
999 * Target record has been renamed to record-full.
1000 Record/replay is now enabled with the "record full" command.
1001 This also affects settings that are associated with full record/replay
1002 that have been moved from "set/show record" to "set/show record full":
1004 set|show record full insn-number-max
1005 set|show record full stop-at-limit
1006 set|show record full memory-query
1008 * A new record target "record-btrace" has been added. The new target
1009 uses hardware support to record the control-flow of a process. It
1010 does not support replaying the execution, but it implements the
1011 below new commands for investigating the recorded execution log.
1012 This new recording method can be enabled using:
1016 The "record-btrace" target is only available on Intel Atom processors
1017 and requires a Linux kernel 2.6.32 or later.
1019 * Two new commands have been added for record/replay to give information
1020 about the recorded execution without having to replay the execution.
1021 The commands are only supported by "record btrace".
1023 record instruction-history prints the execution history at
1024 instruction granularity
1026 record function-call-history prints the execution history at
1027 function granularity
1029 * New native configurations
1031 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1032 FreeBSD/powerpc powerpc*-*-freebsd
1033 x86_64/Cygwin x86_64-*-cygwin*
1034 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1038 ARM AArch64 aarch64*-*-elf
1039 ARM AArch64 GNU/Linux aarch64*-*-linux
1040 Lynx 178 PowerPC powerpc-*-lynx*178
1041 x86_64/Cygwin x86_64-*-cygwin*
1042 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1044 * If the configured location of system.gdbinit file (as given by the
1045 --with-system-gdbinit option at configure time) is in the
1046 data-directory (as specified by --with-gdb-datadir at configure
1047 time) or in one of its subdirectories, then GDB will look for the
1048 system-wide init file in the directory specified by the
1049 --data-directory command-line option.
1051 * New command line options:
1053 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1054 other initialization files, unlike -nx which disables all of them.
1056 * Removed command line options
1058 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1061 * The 'ptype' and 'whatis' commands now accept an argument to control
1064 * 'info proc' now works on some core files.
1068 ** Vectors can be created with gdb.Type.vector.
1070 ** Python's atexit.register now works in GDB.
1072 ** Types can be pretty-printed via a Python API.
1074 ** Python 3 is now supported (in addition to Python 2.4 or later)
1076 ** New class gdb.Architecture exposes GDB's internal representation
1077 of architecture in the Python API.
1079 ** New method Frame.architecture returns the gdb.Architecture object
1080 corresponding to the frame's architecture.
1082 * New Python-based convenience functions:
1084 ** $_memeq(buf1, buf2, length)
1085 ** $_streq(str1, str2)
1087 ** $_regex(str, regex)
1089 * The 'cd' command now defaults to using '~' (the home directory) if not
1092 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1093 default for GCC since November 2000.
1095 * The command 'forward-search' can now be abbreviated as 'fo'.
1097 * The command 'info tracepoints' can now display 'installed on target'
1098 or 'not installed on target' for each non-pending location of tracepoint.
1100 * New configure options
1102 --enable-libmcheck/--disable-libmcheck
1103 By default, development versions are built with -lmcheck on hosts
1104 that support it, in order to help track memory corruption issues.
1105 Release versions, on the other hand, are built without -lmcheck
1106 by default. The --enable-libmcheck/--disable-libmcheck configure
1107 options allow the user to override that default.
1108 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1109 This configure option allows the user to build GDB with
1110 libbabeltrace using which GDB can read Common Trace Format data.
1112 * New commands (for set/show, see "New options" below)
1115 Catch signals. This is similar to "handle", but allows commands and
1116 conditions to be attached.
1119 List the BFDs known to GDB.
1121 python-interactive [command]
1123 Start a Python interactive prompt, or evaluate the optional command
1124 and print the result of expressions.
1127 "py" is a new alias for "python".
1129 enable type-printer [name]...
1130 disable type-printer [name]...
1131 Enable or disable type printers.
1135 ** For the Renesas Super-H architecture, the "regs" command has been removed
1136 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1141 set print type methods (on|off)
1142 show print type methods
1143 Control whether method declarations are displayed by "ptype".
1144 The default is to show them.
1146 set print type typedefs (on|off)
1147 show print type typedefs
1148 Control whether typedef definitions are displayed by "ptype".
1149 The default is to show them.
1151 set filename-display basename|relative|absolute
1152 show filename-display
1153 Control the way in which filenames is displayed.
1154 The default is "relative", which preserves previous behavior.
1156 set trace-buffer-size
1157 show trace-buffer-size
1158 Request target to change the size of trace buffer.
1160 set remote trace-buffer-size-packet auto|on|off
1161 show remote trace-buffer-size-packet
1162 Control the use of the remote protocol `QTBuffer:size' packet.
1166 Control display of debugging messages related to ARM AArch64.
1169 set debug coff-pe-read
1170 show debug coff-pe-read
1171 Control display of debugging messages related to reading of COFF/PE
1176 Control display of debugging messages related to Mach-O symbols
1179 set debug notification
1180 show debug notification
1181 Control display of debugging info for async remote notification.
1185 ** Command parameter changes are now notified using new async record
1186 "=cmd-param-changed".
1187 ** Trace frame changes caused by command "tfind" are now notified using
1188 new async record "=traceframe-changed".
1189 ** The creation, deletion and modification of trace state variables
1190 are now notified using new async records "=tsv-created",
1191 "=tsv-deleted" and "=tsv-modified".
1192 ** The start and stop of process record are now notified using new
1193 async record "=record-started" and "=record-stopped".
1194 ** Memory changes are now notified using new async record
1196 ** The data-disassemble command response will include a "fullname" field
1197 containing the absolute file name when source has been requested.
1198 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1199 command, to allow pattern filling of memory areas.
1200 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1201 library load/unload events.
1202 ** The response to breakpoint commands and breakpoint async records
1203 includes an "installed" field containing a boolean state about each
1204 non-pending tracepoint location is whether installed on target or not.
1205 ** Output of the "-trace-status" command includes a "trace-file" field
1206 containing the name of the trace file being examined. This field is
1207 optional, and only present when examining a trace file.
1208 ** The "fullname" field is now always present along with the "file" field,
1209 even if the file cannot be found by GDB.
1211 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1212 You must have the LZMA library available when configuring GDB for this
1213 feature to be enabled. For more information, see:
1214 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1216 * New remote packets
1219 Set the size of trace buffer. The remote stub reports support for this
1220 packet to gdb's qSupported query.
1223 Enable Branch Trace Store (BTS)-based branch tracing for the current
1224 thread. The remote stub reports support for this packet to gdb's
1228 Disable branch tracing for the current thread. The remote stub reports
1229 support for this packet to gdb's qSupported query.
1232 Read the traced branches for the current thread. The remote stub
1233 reports support for this packet to gdb's qSupported query.
1235 *** Changes in GDB 7.5
1237 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1238 for more x32 ABI info.
1240 * GDB now supports access to MIPS DSP registers on Linux targets.
1242 * GDB now supports debugging microMIPS binaries.
1244 * The "info os" command on GNU/Linux can now display information on
1245 several new classes of objects managed by the operating system:
1246 "info os procgroups" lists process groups
1247 "info os files" lists file descriptors
1248 "info os sockets" lists internet-domain sockets
1249 "info os shm" lists shared-memory regions
1250 "info os semaphores" lists semaphores
1251 "info os msg" lists message queues
1252 "info os modules" lists loaded kernel modules
1254 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1255 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1256 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1257 options and inspect the probe arguments using the new $_probe_arg family
1258 of convenience variables. You can obtain more information about SystemTap
1259 in <http://sourceware.org/systemtap/>.
1261 * GDB now supports reversible debugging on ARM, it allows you to
1262 debug basic ARM and THUMB instructions, and provides
1263 record/replay support.
1265 * The option "symbol-reloading" has been deleted as it is no longer used.
1269 ** GDB commands implemented in Python can now be put in command class
1272 ** The "maint set python print-stack on|off" is now deleted.
1274 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1275 apply "flag enum"-style pretty-printing to any enum.
1277 ** gdb.lookup_symbol can now work when there is no current frame.
1279 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1280 the source at which the symbol was defined.
1282 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1283 method 'value'. The former indicates whether the symbol needs a
1284 frame in order to compute its value, and the latter computes the
1287 ** A new method 'referenced_value' on gdb.Value objects which can
1288 dereference pointer as well as C++ reference values.
1290 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1291 which return the global and static blocks (as gdb.Block objects),
1292 of the underlying symbol table, respectively.
1294 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1295 object associated with a PC value.
1297 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1298 of the address range occupied by code for the current source line.
1300 * Go language support.
1301 GDB now supports debugging programs written in the Go programming
1304 * GDBserver now supports stdio connections.
1305 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1307 * The binary "gdbtui" can no longer be built or installed.
1308 Use "gdb -tui" instead.
1310 * GDB will now print "flag" enums specially. A flag enum is one where
1311 all the enumerator values have no bits in common when pairwise
1312 "and"ed. When printing a value whose type is a flag enum, GDB will
1313 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1314 (gdb) print (enum E) 3
1317 * The filename part of a linespec will now match trailing components
1318 of a source file name. For example, "break gcc/expr.c:1000" will
1319 now set a breakpoint in build/gcc/expr.c, but not
1320 build/libcpp/expr.c.
1322 * The "info proc" and "generate-core-file" commands will now also
1323 work on remote targets connected to GDBserver on Linux.
1325 * The command "info catch" has been removed. It has been disabled
1326 since December 2007.
1328 * The "catch exception" and "catch assert" commands now accept
1329 a condition at the end of the command, much like the "break"
1330 command does. For instance:
1332 (gdb) catch exception Constraint_Error if Barrier = True
1334 Previously, it was possible to add a condition to such catchpoints,
1335 but it had to be done as a second step, after the catchpoint had been
1336 created, using the "condition" command.
1338 * The "info static-tracepoint-marker" command will now also work on
1339 native Linux targets with in-process agent.
1341 * GDB can now set breakpoints on inlined functions.
1343 * The .gdb_index section has been updated to include symbols for
1344 inlined functions. GDB will ignore older .gdb_index sections by
1345 default, which could cause symbol files to be loaded more slowly
1346 until their .gdb_index sections can be recreated. The new command
1347 "set use-deprecated-index-sections on" will cause GDB to use any older
1348 .gdb_index sections it finds. This will restore performance, but the
1349 ability to set breakpoints on inlined functions will be lost in symbol
1350 files with older .gdb_index sections.
1352 The .gdb_index section has also been updated to record more information
1353 about each symbol. This speeds up the "info variables", "info functions"
1354 and "info types" commands when used with programs having the .gdb_index
1355 section, as well as speeding up debugging with shared libraries using
1356 the .gdb_index section.
1358 * Ada support for GDB/MI Variable Objects has been added.
1360 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1365 ** New command -info-os is the MI equivalent of "info os".
1367 ** Output logs ("set logging" and related) now include MI output.
1371 ** "set use-deprecated-index-sections on|off"
1372 "show use-deprecated-index-sections on|off"
1373 Controls the use of deprecated .gdb_index sections.
1375 ** "catch load" and "catch unload" can be used to stop when a shared
1376 library is loaded or unloaded, respectively.
1378 ** "enable count" can be used to auto-disable a breakpoint after
1381 ** "info vtbl" can be used to show the virtual method tables for
1382 C++ and Java objects.
1384 ** "explore" and its sub commands "explore value" and "explore type"
1385 can be used to recursively explore values and types of
1386 expressions. These commands are available only if GDB is
1387 configured with '--with-python'.
1389 ** "info auto-load" shows status of all kinds of auto-loaded files,
1390 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1391 sequences of commands files, "info auto-load python-scripts"
1392 shows status of auto-loading Python script files,
1393 "info auto-load local-gdbinit" shows status of loading init file
1394 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1395 status of inferior specific thread debugging shared library loading.
1397 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1398 and "show auto-load-scripts" commands have been deprecated, use their
1399 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1400 and "show auto-load python-scripts" counterparts instead.
1402 ** "dprintf location,format,args..." creates a dynamic printf, which
1403 is basically a breakpoint that does a printf and immediately
1404 resumes your program's execution, so it is like a printf that you
1405 can insert dynamically at runtime instead of at compiletime.
1407 ** "set print symbol"
1409 Controls whether GDB attempts to display the symbol, if any,
1410 corresponding to addresses it prints. This defaults to "on", but
1411 you can set it to "off" to restore GDB's previous behavior.
1413 * Deprecated commands
1415 ** For the Renesas Super-H architecture, the "regs" command has been
1416 deprecated, and "info all-registers" should be used instead.
1420 Renesas RL78 rl78-*-elf
1421 HP OpenVMS ia64 ia64-hp-openvms*
1423 * GDBserver supports evaluation of breakpoint conditions. When
1424 support is advertised by GDBserver, GDB may be told to send the
1425 breakpoint conditions in bytecode form to GDBserver. GDBserver
1426 will only report the breakpoint trigger to GDB when its condition
1431 set mips compression
1432 show mips compression
1433 Select the compressed ISA encoding used in functions that have no symbol
1434 information available. The encoding can be set to either of:
1437 and is updated automatically from ELF file flags if available.
1439 set breakpoint condition-evaluation
1440 show breakpoint condition-evaluation
1441 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1442 GDBserver ("target"). Default option "auto" chooses the most efficient
1444 This option can improve debugger efficiency depending on the speed of the
1448 Disable auto-loading globally.
1451 Show auto-loading setting of all kinds of auto-loaded files.
1453 set auto-load gdb-scripts on|off
1454 show auto-load gdb-scripts
1455 Control auto-loading of GDB canned sequences of commands files.
1457 set auto-load python-scripts on|off
1458 show auto-load python-scripts
1459 Control auto-loading of Python script files.
1461 set auto-load local-gdbinit on|off
1462 show auto-load local-gdbinit
1463 Control loading of init file (.gdbinit) from current directory.
1465 set auto-load libthread-db on|off
1466 show auto-load libthread-db
1467 Control auto-loading of inferior specific thread debugging shared library.
1469 set auto-load scripts-directory <dir1>[:<dir2>...]
1470 show auto-load scripts-directory
1471 Set a list of directories from which to load auto-loaded scripts.
1472 Automatically loaded Python scripts and GDB scripts are located in one
1473 of the directories listed by this option.
1474 The delimiter (':' above) may differ according to the host platform.
1476 set auto-load safe-path <dir1>[:<dir2>...]
1477 show auto-load safe-path
1478 Set a list of directories from which it is safe to auto-load files.
1479 The delimiter (':' above) may differ according to the host platform.
1481 set debug auto-load on|off
1482 show debug auto-load
1483 Control display of debugging info for auto-loading the files above.
1485 set dprintf-style gdb|call|agent
1487 Control the way in which a dynamic printf is performed; "gdb"
1488 requests a GDB printf command, while "call" causes dprintf to call a
1489 function in the inferior. "agent" requests that the target agent
1490 (such as GDBserver) do the printing.
1492 set dprintf-function <expr>
1493 show dprintf-function
1494 set dprintf-channel <expr>
1495 show dprintf-channel
1496 Set the function and optional first argument to the call when using
1497 the "call" style of dynamic printf.
1499 set disconnected-dprintf on|off
1500 show disconnected-dprintf
1501 Control whether agent-style dynamic printfs continue to be in effect
1502 after GDB disconnects.
1504 * New configure options
1506 --with-auto-load-dir
1507 Configure default value for the 'set auto-load scripts-directory'
1508 setting above. It defaults to '$debugdir:$datadir/auto-load',
1509 $debugdir representing global debugging info directories (available
1510 via 'show debug-file-directory') and $datadir representing GDB's data
1511 directory (available via 'show data-directory').
1513 --with-auto-load-safe-path
1514 Configure default value for the 'set auto-load safe-path' setting
1515 above. It defaults to the --with-auto-load-dir setting.
1517 --without-auto-load-safe-path
1518 Set 'set auto-load safe-path' to '/', effectively disabling this
1521 * New remote packets
1523 z0/z1 conditional breakpoints extension
1525 The z0/z1 breakpoint insertion packets have been extended to carry
1526 a list of conditional expressions over to the remote stub depending on the
1527 condition evaluation mode. The use of this extension can be controlled
1528 via the "set remote conditional-breakpoints-packet" command.
1532 Specify the signals which the remote stub may pass to the debugged
1533 program without GDB involvement.
1535 * New command line options
1537 --init-command=FILE, -ix Like --command, -x but execute it
1538 before loading inferior.
1539 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1540 execute it before loading inferior.
1542 *** Changes in GDB 7.4
1544 * GDB now handles ambiguous linespecs more consistently; the existing
1545 FILE:LINE support has been expanded to other types of linespecs. A
1546 breakpoint will now be set on all matching locations in all
1547 inferiors, and locations will be added or removed according to
1550 * GDB now allows you to skip uninteresting functions and files when
1551 stepping with the "skip function" and "skip file" commands.
1553 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1554 and "show remote hardware-watchpoint-length-limit". These allows to
1555 set or show the maximum length limit (in bytes) of a remote
1556 target hardware watchpoint.
1558 This allows e.g. to use "unlimited" hardware watchpoints with the
1559 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1560 watchpoints are slower than real hardware watchpoints but are
1561 significantly faster than gdb software watchpoints.
1565 ** The register_pretty_printer function in module gdb.printing now takes
1566 an optional `replace' argument. If True, the new printer replaces any
1569 ** The "maint set python print-stack on|off" command has been
1570 deprecated and will be deleted in GDB 7.5.
1571 A new command: "set python print-stack none|full|message" has
1572 replaced it. Additionally, the default for "print-stack" is
1573 now "message", which just prints the error message without
1576 ** A prompt substitution hook (prompt_hook) is now available to the
1579 ** A new Python module, gdb.prompt has been added to the GDB Python
1580 modules library. This module provides functionality for
1581 escape sequences in prompts (used by set/show
1582 extended-prompt). These escape sequences are replaced by their
1583 corresponding value.
1585 ** Python commands and convenience-functions located in
1586 'data-directory'/python/gdb/command and
1587 'data-directory'/python/gdb/function are now automatically loaded
1590 ** Blocks now provide four new attributes. global_block and
1591 static_block will return the global and static blocks
1592 respectively. is_static and is_global are boolean attributes
1593 that indicate if the block is one of those two types.
1595 ** Symbols now provide the "type" attribute, the type of the symbol.
1597 ** The "gdb.breakpoint" function has been deprecated in favor of
1600 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1601 of a function. This class is based on the "finish" command
1602 available in the CLI.
1604 ** Type objects for struct and union types now allow access to
1605 the fields using standard Python dictionary (mapping) methods.
1606 For example, "some_type['myfield']" now works, as does
1607 "some_type.items()".
1609 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1612 ** A new function, "deep_items" has been added to the gdb.types
1613 module in the GDB Python modules library. This function returns
1614 an iterator over the fields of a struct or union type. Unlike
1615 the standard Python "iteritems" method, it will recursively traverse
1616 any anonymous fields.
1620 ** "*stopped" events can report several new "reason"s, such as
1623 ** Breakpoint changes are now notified using new async records, like
1624 "=breakpoint-modified".
1626 ** New command -ada-task-info.
1628 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1629 $sdir specifies the default system locations of shared libraries.
1630 $pdir specifies the directory where the libpthread used by the application
1633 GDB no longer looks in $sdir and $pdir after it has searched the directories
1634 mentioned in libthread-db-search-path. If you want to search those
1635 directories, they must be specified in libthread-db-search-path.
1636 The default value of libthread-db-search-path on GNU/Linux and Solaris
1637 systems is now "$sdir:$pdir".
1639 $pdir is not supported by gdbserver, it is currently ignored.
1640 $sdir is supported by gdbserver.
1642 * New configure option --with-iconv-bin.
1643 When using the internationalization support like the one in the GNU C
1644 library, GDB will invoke the "iconv" program to get a list of supported
1645 character sets. If this program lives in a non-standard location, one can
1646 use this option to specify where to find it.
1648 * When natively debugging programs on PowerPC BookE processors running
1649 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1650 watchpoints, which specify a mask in addition to an address to watch.
1651 The mask specifies that some bits of an address (the bits which are
1652 reset in the mask) should be ignored when matching the address accessed
1653 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1654 section in the user manual for more details.
1656 * The new option --once causes GDBserver to stop listening for connections once
1657 the first connection is made. The listening port used by GDBserver will
1658 become available after that.
1660 * New commands "info macros" and "alias" have been added.
1662 * New function parameters suffix @entry specifies value of function parameter
1663 at the time the function got called. Entry values are available only since
1669 "!" is now an alias of the "shell" command.
1670 Note that no space is needed between "!" and SHELL COMMAND.
1674 watch EXPRESSION mask MASK_VALUE
1675 The watch command now supports the mask argument which allows creation
1676 of masked watchpoints, if the current architecture supports this feature.
1678 info auto-load-scripts [REGEXP]
1679 This command was formerly named "maintenance print section-scripts".
1680 It is now generally useful and is no longer a maintenance-only command.
1682 info macro [-all] [--] MACRO
1683 The info macro command has new options `-all' and `--'. The first for
1684 printing all definitions of a macro. The second for explicitly specifying
1685 the end of arguments and the beginning of the macro name in case the macro
1686 name starts with a hyphen.
1688 collect[/s] EXPRESSIONS
1689 The tracepoint collect command now takes an optional modifier "/s"
1690 that directs it to dereference pointer-to-character types and
1691 collect the bytes of memory up to a zero byte. The behavior is
1692 similar to what you see when you use the regular print command on a
1693 string. An optional integer following the "/s" sets a bound on the
1694 number of bytes that will be collected.
1697 The trace start command now interprets any supplied arguments as a
1698 note to be recorded with the trace run, with an effect similar to
1699 setting the variable trace-notes.
1702 The trace stop command now interprets any arguments as a note to be
1703 mentioned along with the tstatus report that the trace was stopped
1704 with a command. The effect is similar to setting the variable
1707 * Tracepoints can now be enabled and disabled at any time after a trace
1708 experiment has been started using the standard "enable" and "disable"
1709 commands. It is now possible to start a trace experiment with no enabled
1710 tracepoints; GDB will display a warning, but will allow the experiment to
1711 begin, assuming that tracepoints will be enabled as needed while the trace
1714 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1715 locations with 4-byte instructions, when they were previously
1716 limited to locations with instructions of 5 bytes or longer.
1720 set debug dwarf2-read
1721 show debug dwarf2-read
1722 Turns on or off display of debugging messages related to reading
1723 DWARF debug info. The default is off.
1725 set debug symtab-create
1726 show debug symtab-create
1727 Turns on or off display of debugging messages related to symbol table
1728 creation. The default is off.
1731 show extended-prompt
1732 Set the GDB prompt, and allow escape sequences to be inserted to
1733 display miscellaneous information (see 'help set extended-prompt'
1734 for the list of sequences). This prompt (and any information
1735 accessed through the escape sequences) is updated every time the
1736 prompt is displayed.
1738 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1739 show print entry-values
1740 Set printing of frame argument values at function entry. In some cases
1741 GDB can determine the value of function argument which was passed by the
1742 function caller, even if the value was modified inside the called function.
1744 set debug entry-values
1745 show debug entry-values
1746 Control display of debugging info for determining frame argument values at
1747 function entry and virtual tail call frames.
1749 set basenames-may-differ
1750 show basenames-may-differ
1751 Set whether a source file may have multiple base names.
1752 (A "base name" is the name of a file with the directory part removed.
1753 Example: The base name of "/home/user/hello.c" is "hello.c".)
1754 If set, GDB will canonicalize file names (e.g., expand symlinks)
1755 before comparing them. Canonicalization is an expensive operation,
1756 but it allows the same file be known by more than one base name.
1757 If not set (the default), all source files are assumed to have just
1758 one base name, and gdb will do file name comparisons more efficiently.
1764 Set a user name and notes for the current and any future trace runs.
1765 This is useful for long-running and/or disconnected traces, to
1766 inform others (or yourself) as to who is running the trace, supply
1767 contact information, or otherwise explain what is going on.
1769 set trace-stop-notes
1770 show trace-stop-notes
1771 Set a note attached to the trace run, that is displayed when the
1772 trace has been stopped by a tstop command. This is useful for
1773 instance as an explanation, if you are stopping a trace run that was
1774 started by someone else.
1776 * New remote packets
1780 Dynamically enable a tracepoint in a started trace experiment.
1784 Dynamically disable a tracepoint in a started trace experiment.
1788 Set the user and notes of the trace run.
1792 Query the current status of a tracepoint.
1796 Query the minimum length of instruction at which a fast tracepoint may
1799 * Dcache size (number of lines) and line-size are now runtime-configurable
1800 via "set dcache line" and "set dcache line-size" commands.
1804 Texas Instruments TMS320C6x tic6x-*-*
1808 Renesas RL78 rl78-*-elf
1810 *** Changes in GDB 7.3.1
1812 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1814 *** Changes in GDB 7.3
1816 * GDB has a new command: "thread find [REGEXP]".
1817 It finds the thread id whose name, target id, or thread extra info
1818 matches the given regular expression.
1820 * The "catch syscall" command now works on mips*-linux* targets.
1822 * The -data-disassemble MI command now supports modes 2 and 3 for
1823 dumping the instruction opcodes.
1825 * New command line options
1827 -data-directory DIR Specify DIR as the "data-directory".
1828 This is mostly for testing purposes.
1830 * The "maint set python auto-load on|off" command has been renamed to
1831 "set auto-load-scripts on|off".
1833 * GDB has a new command: "set directories".
1834 It is like the "dir" command except that it replaces the
1835 source path list instead of augmenting it.
1837 * GDB now understands thread names.
1839 On GNU/Linux, "info threads" will display the thread name as set by
1840 prctl or pthread_setname_np.
1842 There is also a new command, "thread name", which can be used to
1843 assign a name internally for GDB to display.
1846 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1847 has been integrated into GDB.
1851 ** The function gdb.Write now accepts an optional keyword 'stream'.
1852 This keyword, when provided, will direct the output to either
1853 stdout, stderr, or GDB's logging output.
1855 ** Parameters can now be be sub-classed in Python, and in particular
1856 you may implement the get_set_doc and get_show_doc functions.
1857 This improves how Parameter set/show documentation is processed
1858 and allows for more dynamic content.
1860 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1861 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1862 have an is_valid method.
1864 ** Breakpoints can now be sub-classed in Python, and in particular
1865 you may implement a 'stop' function that is executed each time
1866 the inferior reaches that breakpoint.
1868 ** New function gdb.lookup_global_symbol looks up a global symbol.
1870 ** GDB values in Python are now callable if the value represents a
1871 function. For example, if 'some_value' represents a function that
1872 takes two integer parameters and returns a value, you can call
1873 that function like so:
1875 result = some_value (10,20)
1877 ** Module gdb.types has been added.
1878 It contains a collection of utilities for working with gdb.Types objects:
1879 get_basic_type, has_field, make_enum_dict.
1881 ** Module gdb.printing has been added.
1882 It contains utilities for writing and registering pretty-printers.
1883 New classes: PrettyPrinter, SubPrettyPrinter,
1884 RegexpCollectionPrettyPrinter.
1885 New function: register_pretty_printer.
1887 ** New commands "info pretty-printers", "enable pretty-printer" and
1888 "disable pretty-printer" have been added.
1890 ** gdb.parameter("directories") is now available.
1892 ** New function gdb.newest_frame returns the newest frame in the
1895 ** The gdb.InferiorThread class has a new "name" attribute. This
1896 holds the thread's name.
1898 ** Python Support for Inferior events.
1899 Python scripts can add observers to be notified of events
1900 occurring in the process being debugged.
1901 The following events are currently supported:
1902 - gdb.events.cont Continue event.
1903 - gdb.events.exited Inferior exited event.
1904 - gdb.events.stop Signal received, and Breakpoint hit events.
1908 ** GDB now puts template parameters in scope when debugging in an
1909 instantiation. For example, if you have:
1911 template<int X> int func (void) { return X; }
1913 then if you step into func<5>, "print X" will show "5". This
1914 feature requires proper debuginfo support from the compiler; it
1915 was added to GCC 4.5.
1917 ** The motion commands "next", "finish", "until", and "advance" now
1918 work better when exceptions are thrown. In particular, GDB will
1919 no longer lose control of the inferior; instead, the GDB will
1920 stop the inferior at the point at which the exception is caught.
1921 This functionality requires a change in the exception handling
1922 code that was introduced in GCC 4.5.
1924 * GDB now follows GCC's rules on accessing volatile objects when
1925 reading or writing target state during expression evaluation.
1926 One notable difference to prior behavior is that "print x = 0"
1927 no longer generates a read of x; the value of the assignment is
1928 now always taken directly from the value being assigned.
1930 * GDB now has some support for using labels in the program's source in
1931 linespecs. For instance, you can use "advance label" to continue
1932 execution to a label.
1934 * GDB now has support for reading and writing a new .gdb_index
1935 section. This section holds a fast index of DWARF debugging
1936 information and can be used to greatly speed up GDB startup and
1937 operation. See the documentation for `save gdb-index' for details.
1939 * The "watch" command now accepts an optional "-location" argument.
1940 When used, this causes GDB to watch the memory referred to by the
1941 expression. Such a watchpoint is never deleted due to it going out
1944 * GDB now supports thread debugging of core dumps on GNU/Linux.
1946 GDB now activates thread debugging using the libthread_db library
1947 when debugging GNU/Linux core dumps, similarly to when debugging
1948 live processes. As a result, when debugging a core dump file, GDB
1949 is now able to display pthread_t ids of threads. For example, "info
1950 threads" shows the same output as when debugging the process when it
1951 was live. In earlier releases, you'd see something like this:
1954 * 1 LWP 6780 main () at main.c:10
1956 While now you see this:
1959 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1961 It is also now possible to inspect TLS variables when debugging core
1964 When debugging a core dump generated on a machine other than the one
1965 used to run GDB, you may need to point GDB at the correct
1966 libthread_db library with the "set libthread-db-search-path"
1967 command. See the user manual for more details on this command.
1969 * When natively debugging programs on PowerPC BookE processors running
1970 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1971 which stop execution of the inferior whenever it executes an instruction
1972 at any address within the specified range. See the "PowerPC Embedded"
1973 section in the user manual for more details.
1975 * New features in the GDB remote stub, GDBserver
1977 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1978 and i686 LynxOS (version 5.x).
1980 ** GDBserver is now supported on Blackfin Linux.
1982 * New native configurations
1984 ia64 HP-UX ia64-*-hpux*
1988 Analog Devices, Inc. Blackfin Processor bfin-*
1990 * Ada task switching is now supported on sparc-elf targets when
1991 debugging a program using the Ravenscar Profile. For more information,
1992 see the "Tasking Support when using the Ravenscar Profile" section
1993 in the GDB user manual.
1995 * Guile support was removed.
1997 * New features in the GNU simulator
1999 ** The --map-info flag lists all known core mappings.
2001 ** CFI flashes may be simulated via the "cfi" device.
2003 *** Changes in GDB 7.2
2005 * Shared library support for remote targets by default
2007 When GDB is configured for a generic, non-OS specific target, like
2008 for example, --target=arm-eabi or one of the many *-*-elf targets,
2009 GDB now queries remote stubs for loaded shared libraries using the
2010 `qXfer:libraries:read' packet. Previously, shared library support
2011 was always disabled for such configurations.
2015 ** Argument Dependent Lookup (ADL)
2017 In C++ ADL lookup directs function search to the namespaces of its
2018 arguments even if the namespace has not been imported.
2028 Here the compiler will search for `foo' in the namespace of 'b'
2029 and find A::foo. GDB now supports this. This construct is commonly
2030 used in the Standard Template Library for operators.
2032 ** Improved User Defined Operator Support
2034 In addition to member operators, GDB now supports lookup of operators
2035 defined in a namespace and imported with a `using' directive, operators
2036 defined in the global scope, operators imported implicitly from an
2037 anonymous namespace, and the ADL operators mentioned in the previous
2039 GDB now also supports proper overload resolution for all the previously
2040 mentioned flavors of operators.
2042 ** static const class members
2044 Printing of static const class members that are initialized in the
2045 class definition has been fixed.
2047 * Windows Thread Information Block access.
2049 On Windows targets, GDB now supports displaying the Windows Thread
2050 Information Block (TIB) structure. This structure is visible either
2051 by using the new command `info w32 thread-information-block' or, by
2052 dereferencing the new convenience variable named `$_tlb', a
2053 thread-specific pointer to the TIB. This feature is also supported
2054 when remote debugging using GDBserver.
2056 * Static tracepoints
2058 Static tracepoints are calls in the user program into a tracing
2059 library. One such library is a port of the LTTng kernel tracer to
2060 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2061 When debugging with GDBserver, GDB now supports combining the GDB
2062 tracepoint machinery with such libraries. For example: the user can
2063 use GDB to probe a static tracepoint marker (a call from the user
2064 program into the tracing library) with the new "strace" command (see
2065 "New commands" below). This creates a "static tracepoint" in the
2066 breakpoint list, that can be manipulated with the same feature set
2067 as fast and regular tracepoints. E.g., collect registers, local and
2068 global variables, collect trace state variables, and define
2069 tracepoint conditions. In addition, the user can collect extra
2070 static tracepoint marker specific data, by collecting the new
2071 $_sdata internal variable. When analyzing the trace buffer, you can
2072 inspect $_sdata like any other variable available to GDB. For more
2073 information, see the "Tracepoints" chapter in GDB user manual. New
2074 remote packets have been defined to support static tracepoints, see
2075 the "New remote packets" section below.
2077 * Better reconstruction of tracepoints after disconnected tracing
2079 GDB will attempt to download the original source form of tracepoint
2080 definitions when starting a trace run, and then will upload these
2081 upon reconnection to the target, resulting in a more accurate
2082 reconstruction of the tracepoints that are in use on the target.
2086 You can now exercise direct control over the ways that GDB can
2087 affect your program. For instance, you can disallow the setting of
2088 breakpoints, so that the program can run continuously (assuming
2089 non-stop mode). In addition, the "observer" variable is available
2090 to switch all of the different controls; in observer mode, GDB
2091 cannot affect the target's behavior at all, which is useful for
2092 tasks like diagnosing live systems in the field.
2094 * The new convenience variable $_thread holds the number of the
2097 * New remote packets
2101 Return the address of the Windows Thread Information Block of a given thread.
2105 In response to several of the tracepoint packets, the target may now
2106 also respond with a number of intermediate `qRelocInsn' request
2107 packets before the final result packet, to have GDB handle
2108 relocating an instruction to execute at a different address. This
2109 is particularly useful for stubs that support fast tracepoints. GDB
2110 reports support for this feature in the qSupported packet.
2114 List static tracepoint markers in the target program.
2118 List static tracepoint markers at a given address in the target
2121 qXfer:statictrace:read
2123 Read the static trace data collected (by a `collect $_sdata'
2124 tracepoint action). The remote stub reports support for this packet
2125 to gdb's qSupported query.
2129 Send the current settings of GDB's permission flags.
2133 Send part of the source (textual) form of a tracepoint definition,
2134 which includes location, conditional, and action list.
2136 * The source command now accepts a -s option to force searching for the
2137 script in the source search path even if the script name specifies
2140 * New features in the GDB remote stub, GDBserver
2142 - GDBserver now support tracepoints (including fast tracepoints, and
2143 static tracepoints). The feature is currently supported by the
2144 i386-linux and amd64-linux builds. See the "Tracepoints support
2145 in gdbserver" section in the manual for more information.
2147 GDBserver JIT compiles the tracepoint's conditional agent
2148 expression bytecode into native code whenever possible for low
2149 overhead dynamic tracepoints conditionals. For such tracepoints,
2150 an expression that examines program state is evaluated when the
2151 tracepoint is reached, in order to determine whether to capture
2152 trace data. If the condition is simple and false, processing the
2153 tracepoint finishes very quickly and no data is gathered.
2155 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2156 for static tracepoints support.
2158 - GDBserver now supports x86_64 Windows 64-bit debugging.
2160 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2161 it understands register description.
2163 * The --batch flag now disables pagination and queries.
2165 * X86 general purpose registers
2167 GDB now supports reading/writing byte, word and double-word x86
2168 general purpose registers directly. This means you can use, say,
2169 $ah or $ax to refer, respectively, to the byte register AH and
2170 16-bit word register AX that are actually portions of the 32-bit
2171 register EAX or 64-bit register RAX.
2173 * The `commands' command now accepts a range of breakpoints to modify.
2174 A plain `commands' following a command that creates multiple
2175 breakpoints affects all the breakpoints set by that command. This
2176 applies to breakpoints set by `rbreak', and also applies when a
2177 single `break' command creates multiple breakpoints (e.g.,
2178 breakpoints on overloaded c++ functions).
2180 * The `rbreak' command now accepts a filename specification as part of
2181 its argument, limiting the functions selected by the regex to those
2182 in the specified file.
2184 * Support for remote debugging Windows and SymbianOS shared libraries
2185 from Unix hosts has been improved. Non Windows GDB builds now can
2186 understand target reported file names that follow MS-DOS based file
2187 system semantics, such as file names that include drive letters and
2188 use the backslash character as directory separator. This makes it
2189 possible to transparently use the "set sysroot" and "set
2190 solib-search-path" on Unix hosts to point as host copies of the
2191 target's shared libraries. See the new command "set
2192 target-file-system-kind" described below, and the "Commands to
2193 specify files" section in the user manual for more information.
2197 eval template, expressions...
2198 Convert the values of one or more expressions under the control
2199 of the string template to a command line, and call it.
2201 set target-file-system-kind unix|dos-based|auto
2202 show target-file-system-kind
2203 Set or show the assumed file system kind for target reported file
2206 save breakpoints <filename>
2207 Save all current breakpoint definitions to a file suitable for use
2208 in a later debugging session. To read the saved breakpoint
2209 definitions, use the `source' command.
2211 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2214 info static-tracepoint-markers
2215 Display information about static tracepoint markers in the target.
2217 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2218 Define a static tracepoint by probing a marker at the given
2219 function, line, address, or marker ID.
2223 Enable and disable observer mode.
2225 set may-write-registers on|off
2226 set may-write-memory on|off
2227 set may-insert-breakpoints on|off
2228 set may-insert-tracepoints on|off
2229 set may-insert-fast-tracepoints on|off
2230 set may-interrupt on|off
2231 Set individual permissions for GDB effects on the target. Note that
2232 some of these settings can have undesirable or surprising
2233 consequences, particularly when changed in the middle of a session.
2234 For instance, disabling the writing of memory can prevent
2235 breakpoints from being inserted, cause single-stepping to fail, or
2236 even crash your program, if you disable after breakpoints have been
2237 inserted. However, GDB should not crash.
2239 set record memory-query on|off
2240 show record memory-query
2241 Control whether to stop the inferior if memory changes caused
2242 by an instruction cannot be recorded.
2247 The disassemble command now supports "start,+length" form of two arguments.
2251 ** GDB now provides a new directory location, called the python directory,
2252 where Python scripts written for GDB can be installed. The location
2253 of that directory is <data-directory>/python, where <data-directory>
2254 is the GDB data directory. For more details, see section `Scripting
2255 GDB using Python' in the manual.
2257 ** The GDB Python API now has access to breakpoints, symbols, symbol
2258 tables, program spaces, inferiors, threads and frame's code blocks.
2259 Additionally, GDB Parameters can now be created from the API, and
2260 manipulated via set/show in the CLI.
2262 ** New functions gdb.target_charset, gdb.target_wide_charset,
2263 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2265 ** New exception gdb.GdbError.
2267 ** Pretty-printers are now also looked up in the current program space.
2269 ** Pretty-printers can now be individually enabled and disabled.
2271 ** GDB now looks for names of Python scripts to auto-load in a
2272 special section named `.debug_gdb_scripts', in addition to looking
2273 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2275 * Tracepoint actions were unified with breakpoint commands. In particular,
2276 there are no longer differences in "info break" output for breakpoints and
2277 tracepoints and the "commands" command can be used for both tracepoints and
2278 regular breakpoints.
2282 ARM Symbian arm*-*-symbianelf*
2284 * D language support.
2285 GDB now supports debugging programs written in the D programming
2288 * GDB now supports the extended ptrace interface for PowerPC which is
2289 available since Linux kernel version 2.6.34. This automatically enables
2290 any hardware breakpoints and additional hardware watchpoints available in
2291 the processor. The old ptrace interface exposes just one hardware
2292 watchpoint and no hardware breakpoints.
2294 * GDB is now able to use the Data Value Compare (DVC) register available on
2295 embedded PowerPC processors to implement in hardware simple watchpoint
2296 conditions of the form:
2298 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2300 This works in native GDB running on Linux kernels with the extended ptrace
2301 interface mentioned above.
2303 *** Changes in GDB 7.1
2307 ** Namespace Support
2309 GDB now supports importing of namespaces in C++. This enables the
2310 user to inspect variables from imported namespaces. Support for
2311 namepace aliasing has also been added. So, if a namespace is
2312 aliased in the current scope (e.g. namepace C=A; ) the user can
2313 print variables using the alias (e.g. (gdb) print C::x).
2317 All known bugs relating to the printing of virtual base class were
2318 fixed. It is now possible to call overloaded static methods using a
2323 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2324 and reinterpret_cast<> are now handled by the C++ expression parser.
2328 Xilinx MicroBlaze microblaze-*-*
2333 Xilinx MicroBlaze microblaze
2336 * Multi-program debugging.
2338 GDB now has support for multi-program (a.k.a. multi-executable or
2339 multi-exec) debugging. This allows for debugging multiple inferiors
2340 simultaneously each running a different program under the same GDB
2341 session. See "Debugging Multiple Inferiors and Programs" in the
2342 manual for more information. This implied some user visible changes
2343 in the multi-inferior support. For example, "info inferiors" now
2344 lists inferiors that are not running yet or that have exited
2345 already. See also "New commands" and "New options" below.
2347 * New tracing features
2349 GDB's tracepoint facility now includes several new features:
2351 ** Trace state variables
2353 GDB tracepoints now include support for trace state variables, which
2354 are variables managed by the target agent during a tracing
2355 experiment. They are useful for tracepoints that trigger each
2356 other, so for instance one tracepoint can count hits in a variable,
2357 and then a second tracepoint has a condition that is true when the
2358 count reaches a particular value. Trace state variables share the
2359 $-syntax of GDB convenience variables, and can appear in both
2360 tracepoint actions and condition expressions. Use the "tvariable"
2361 command to create, and "info tvariables" to view; see "Trace State
2362 Variables" in the manual for more detail.
2366 GDB now includes an option for defining fast tracepoints, which
2367 targets may implement more efficiently, such as by installing a jump
2368 into the target agent rather than a trap instruction. The resulting
2369 speedup can be by two orders of magnitude or more, although the
2370 tradeoff is that some program locations on some target architectures
2371 might not allow fast tracepoint installation, for instance if the
2372 instruction to be replaced is shorter than the jump. To request a
2373 fast tracepoint, use the "ftrace" command, with syntax identical to
2374 the regular trace command.
2376 ** Disconnected tracing
2378 It is now possible to detach GDB from the target while it is running
2379 a trace experiment, then reconnect later to see how the experiment
2380 is going. In addition, a new variable disconnected-tracing lets you
2381 tell the target agent whether to continue running a trace if the
2382 connection is lost unexpectedly.
2386 GDB now has the ability to save the trace buffer into a file, and
2387 then use that file as a target, similarly to you can do with
2388 corefiles. You can select trace frames, print data that was
2389 collected in them, and use tstatus to display the state of the
2390 tracing run at the moment that it was saved. To create a trace
2391 file, use "tsave <filename>", and to use it, do "target tfile
2394 ** Circular trace buffer
2396 You can ask the target agent to handle the trace buffer as a
2397 circular buffer, discarding the oldest trace frames to make room for
2398 newer ones, by setting circular-trace-buffer to on. This feature may
2399 not be available for all target agents.
2404 The disassemble command, when invoked with two arguments, now requires
2405 the arguments to be comma-separated.
2408 The info variables command now displays variable definitions. Files
2409 which only declare a variable are not shown.
2412 The source command is now capable of sourcing Python scripts.
2413 This feature is dependent on the debugger being build with Python
2416 Related to this enhancement is also the introduction of a new command
2417 "set script-extension" (see below).
2419 * New commands (for set/show, see "New options" below)
2421 record save [<FILENAME>]
2422 Save a file (in core file format) containing the process record
2423 execution log for replay debugging at a later time.
2425 record restore <FILENAME>
2426 Restore the process record execution log that was saved at an
2427 earlier time, for replay debugging.
2429 add-inferior [-copies <N>] [-exec <FILENAME>]
2432 clone-inferior [-copies <N>] [ID]
2433 Make a new inferior ready to execute the same program another
2434 inferior has loaded.
2439 maint info program-spaces
2440 List the program spaces loaded into GDB.
2442 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2443 show remote interrupt-sequence
2444 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2445 as the sequence to the remote target in order to interrupt the execution.
2446 Ctrl-C is a default. Some system prefers BREAK which is high level of
2447 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2448 Magic SysRq g. It is BREAK signal and character 'g'.
2450 set remote interrupt-on-connect [on | off]
2451 show remote interrupt-on-connect
2452 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2453 remote target when gdb connects to it. This is needed when you debug
2456 set remotebreak [on | off]
2458 Deprecated. Use "set/show remote interrupt-sequence" instead.
2460 tvariable $NAME [ = EXP ]
2461 Create or modify a trace state variable.
2464 List trace state variables and their values.
2466 delete tvariable $NAME ...
2467 Delete one or more trace state variables.
2470 Evaluate the given expressions without collecting anything into the
2471 trace buffer. (Valid in tracepoint actions only.)
2473 ftrace FN / FILE:LINE / *ADDR
2474 Define a fast tracepoint at the given function, line, or address.
2476 * New expression syntax
2478 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2479 GDB now parses 0b101010 identically with 42.
2483 set follow-exec-mode new|same
2484 show follow-exec-mode
2485 Control whether GDB reuses the same inferior across an exec call or
2486 creates a new one. This is useful to be able to restart the old
2487 executable after the inferior having done an exec call.
2489 set default-collect EXPR, ...
2490 show default-collect
2491 Define a list of expressions to be collected at each tracepoint.
2492 This is a useful way to ensure essential items are not overlooked,
2493 such as registers or a critical global variable.
2495 set disconnected-tracing
2496 show disconnected-tracing
2497 If set to 1, the target is instructed to continue tracing if it
2498 loses its connection to GDB. If 0, the target is to stop tracing
2501 set circular-trace-buffer
2502 show circular-trace-buffer
2503 If set to on, the target is instructed to use a circular trace buffer
2504 and discard the oldest trace frames instead of stopping the trace due
2505 to a full trace buffer. If set to off, the trace stops when the buffer
2506 fills up. Some targets may not support this.
2508 set script-extension off|soft|strict
2509 show script-extension
2510 If set to "off", the debugger does not perform any script language
2511 recognition, and all sourced files are assumed to be GDB scripts.
2512 If set to "soft" (the default), files are sourced according to
2513 filename extension, falling back to GDB scripts if the first
2515 If set to "strict", files are sourced according to filename extension.
2517 set ada trust-PAD-over-XVS on|off
2518 show ada trust-PAD-over-XVS
2519 If off, activate a workaround against a bug in the debugging information
2520 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2521 the GCC sources for more information about the GNAT encoding and
2522 PAD types in particular). It is always safe to set this option to
2523 off, but this introduces a slight performance penalty. The default
2526 * Python API Improvements
2528 ** GDB provides the new class gdb.LazyString. This is useful in
2529 some pretty-printing cases. The new method gdb.Value.lazy_string
2530 provides a simple way to create objects of this type.
2532 ** The fields returned by gdb.Type.fields now have an
2533 `is_base_class' attribute.
2535 ** The new method gdb.Type.range returns the range of an array type.
2537 ** The new method gdb.parse_and_eval can be used to parse and
2538 evaluate an expression.
2540 * New remote packets
2543 Define a trace state variable.
2546 Get the current value of a trace state variable.
2549 Set desired tracing behavior upon disconnection.
2552 Set the trace buffer to be linear or circular.
2555 Get data about the tracepoints currently in use.
2559 Process record now works correctly with hardware watchpoints.
2561 Multiple bug fixes have been made to the mips-irix port, making it
2562 much more reliable. In particular:
2563 - Debugging threaded applications is now possible again. Previously,
2564 GDB would hang while starting the program, or while waiting for
2565 the program to stop at a breakpoint.
2566 - Attaching to a running process no longer hangs.
2567 - An error occurring while loading a core file has been fixed.
2568 - Changing the value of the PC register now works again. This fixes
2569 problems observed when using the "jump" command, or when calling
2570 a function from GDB, or even when assigning a new value to $pc.
2571 - With the "finish" and "return" commands, the return value for functions
2572 returning a small array is now correctly printed.
2573 - It is now possible to break on shared library code which gets executed
2574 during a shared library init phase (code executed while executing
2575 their .init section). Previously, the breakpoint would have no effect.
2576 - GDB is now able to backtrace through the signal handler for
2577 non-threaded programs.
2579 PIE (Position Independent Executable) programs debugging is now supported.
2580 This includes debugging execution of PIC (Position Independent Code) shared
2581 libraries although for that, it should be possible to run such libraries as an
2584 *** Changes in GDB 7.0
2586 * GDB now has an interface for JIT compilation. Applications that
2587 dynamically generate code can create symbol files in memory and register
2588 them with GDB. For users, the feature should work transparently, and
2589 for JIT developers, the interface is documented in the GDB manual in the
2590 "JIT Compilation Interface" chapter.
2592 * Tracepoints may now be conditional. The syntax is as for
2593 breakpoints; either an "if" clause appended to the "trace" command,
2594 or the "condition" command is available. GDB sends the condition to
2595 the target for evaluation using the same bytecode format as is used
2596 for tracepoint actions.
2598 * The disassemble command now supports: an optional /r modifier, print the
2599 raw instructions in hex as well as in symbolic form, and an optional /m
2600 modifier to print mixed source+assembly.
2602 * Process record and replay
2604 In a architecture environment that supports ``process record and
2605 replay'', ``process record and replay'' target can record a log of
2606 the process execution, and replay it with both forward and reverse
2609 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2610 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2611 set execution-direction {forward|reverse}, for targets that support
2614 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2615 feature is available with a native GDB running on kernel version
2618 * GDB now has support for multi-byte and wide character sets on the
2619 target. Strings whose character type is wchar_t, char16_t, or
2620 char32_t are now correctly printed. GDB supports wide- and unicode-
2621 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2622 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2623 `printf'. This feature requires iconv to work properly; if your
2624 system does not have a working iconv, GDB can use GNU libiconv. See
2625 the installation instructions for more information.
2627 * GDB now supports automatic retrieval of shared library files from
2628 remote targets. To use this feature, specify a system root that begins
2629 with the `remote:' prefix, either via the `set sysroot' command or via
2630 the `--with-sysroot' configure-time option.
2632 * "info sharedlibrary" now takes an optional regex of libraries to show,
2633 and it now reports if a shared library has no debugging information.
2635 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2636 now complete on file names.
2638 * When completing in expressions, gdb will attempt to limit
2639 completions to allowable structure or union fields, where appropriate.
2640 For instance, consider:
2642 # struct example { int f1; double f2; };
2643 # struct example variable;
2646 If the user types TAB at the end of this command line, the available
2647 completions will be "f1" and "f2".
2649 * Inlined functions are now supported. They show up in backtraces, and
2650 the "step", "next", and "finish" commands handle them automatically.
2652 * GDB now supports the token-splicing (##) and stringification (#)
2653 operators when expanding macros. It also supports variable-arity
2656 * GDB now supports inspecting extra signal information, exported by
2657 the new $_siginfo convenience variable. The feature is currently
2658 implemented on linux ARM, i386 and amd64.
2660 * GDB can now display the VFP floating point registers and NEON vector
2661 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2662 can provide these registers (requires Linux 2.6.30 or later). Remote
2663 and simulator targets may also provide them.
2665 * New remote packets
2668 Search memory for a sequence of bytes.
2671 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2672 operation over reliable transport links. Use of this packet is
2673 controlled by the `set remote noack-packet' command.
2676 Kill the process with the specified process ID. Use this in preference
2677 to `k' when multiprocess protocol extensions are supported.
2680 Obtains additional operating system information
2684 Read or write additional signal information.
2686 * Removed remote protocol undocumented extension
2688 An undocumented extension to the remote protocol's `S' stop reply
2689 packet that permited the stub to pass a process id was removed.
2690 Remote servers should use the `T' stop reply packet instead.
2692 * GDB now supports multiple function calling conventions according to the
2693 DWARF-2 DW_AT_calling_convention function attribute.
2695 * The SH target utilizes the aforementioned change to distinguish between gcc
2696 and Renesas calling convention. It also adds the new CLI commands
2697 `set/show sh calling-convention'.
2699 * GDB can now read compressed debug sections, as produced by GNU gold
2700 with the --compress-debug-sections=zlib flag.
2702 * 64-bit core files are now supported on AIX.
2704 * Thread switching is now supported on Tru64.
2706 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2707 which will be allocated using malloc later in program execution.
2709 * The qXfer:libraries:read remote procotol packet now allows passing a
2710 list of section offsets.
2712 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2713 conditions handling signals delivered during attach or thread creation
2714 have also been fixed.
2716 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2717 From the user's standpoint, all unqualified instances of True and False
2718 are treated as the standard definitions, regardless of context.
2720 * GDB now parses C++ symbol and type names more flexibly. For
2723 template<typename T> class C { };
2726 GDB will now correctly handle all of:
2728 ptype C<char const *>
2729 ptype C<char const*>
2730 ptype C<const char *>
2731 ptype C<const char*>
2733 * New features in the GDB remote stub, gdbserver
2735 - The "--wrapper" command-line argument tells gdbserver to use a
2736 wrapper program to launch programs for debugging.
2738 - On PowerPC and S/390 targets, it is now possible to use a single
2739 gdbserver executable to debug both 32-bit and 64-bit programs.
2740 (This requires gdbserver itself to be built as a 64-bit executable.)
2742 - gdbserver uses the new noack protocol mode for TCP connections to
2743 reduce communications latency, if also supported and enabled in GDB.
2745 - Support for the sparc64-linux-gnu target is now included in
2748 - The amd64-linux build of gdbserver now supports debugging both
2749 32-bit and 64-bit programs.
2751 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2752 now support hardware watchpoints, and will use them automatically
2757 GDB now has support for scripting using Python. Whether this is
2758 available is determined at configure time.
2760 New GDB commands can now be written in Python.
2762 * Ada tasking support
2764 Ada tasks can now be inspected in GDB. The following commands have
2768 Print the list of Ada tasks.
2770 Print detailed information about task number N.
2772 Print the task number of the current task.
2774 Switch the context of debugging to task number N.
2776 * Support for user-defined prefixed commands. The "define" command can
2777 add new commands to existing prefixes, e.g. "target".
2779 * Multi-inferior, multi-process debugging.
2781 GDB now has generalized support for multi-inferior debugging. See
2782 "Debugging Multiple Inferiors" in the manual for more information.
2783 Although availability still depends on target support, the command
2784 set is more uniform now. The GNU/Linux specific multi-forks support
2785 has been migrated to this new framework. This implied some user
2786 visible changes; see "New commands" and also "Removed commands"
2789 * Target descriptions can now describe the target OS ABI. See the
2790 "Target Description Format" section in the user manual for more
2793 * Target descriptions can now describe "compatible" architectures
2794 to indicate that the target can execute applications for a different
2795 architecture in addition to those for the main target architecture.
2796 See the "Target Description Format" section in the user manual for
2799 * Multi-architecture debugging.
2801 GDB now includes general supports for debugging applications on
2802 hybrid systems that use more than one single processor architecture
2803 at the same time. Each such hybrid architecture still requires
2804 specific support to be added. The only hybrid architecture supported
2805 in this version of GDB is the Cell Broadband Engine.
2807 * GDB now supports integrated debugging of Cell/B.E. applications that
2808 use both the PPU and SPU architectures. To enable support for hybrid
2809 Cell/B.E. debugging, you need to configure GDB to support both the
2810 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2811 --enable-targets configure option.
2813 * Non-stop mode debugging.
2815 For some targets, GDB now supports an optional mode of operation in
2816 which you can examine stopped threads while other threads continue
2817 to execute freely. This is referred to as non-stop mode, with the
2818 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2819 section in the user manual for more information.
2821 To be able to support remote non-stop debugging, a remote stub needs
2822 to implement the non-stop mode remote protocol extensions, as
2823 described in the "Remote Non-Stop" section of the user manual. The
2824 GDB remote stub, gdbserver, has been adjusted to support these
2825 extensions on linux targets.
2827 * New commands (for set/show, see "New options" below)
2829 catch syscall [NAME(S) | NUMBER(S)]
2830 Catch system calls. Arguments, which should be names of system
2831 calls or their numbers, mean catch only those syscalls. Without
2832 arguments, every syscall will be caught. When the inferior issues
2833 any of the specified syscalls, GDB will stop and announce the system
2834 call, both when it is called and when its call returns. This
2835 feature is currently available with a native GDB running on the
2836 Linux Kernel, under the following architectures: x86, x86_64,
2837 PowerPC and PowerPC64.
2839 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2841 Search memory for a sequence of bytes.
2843 maint set python print-stack
2844 maint show python print-stack
2845 Show a stack trace when an error is encountered in a Python script.
2848 Invoke CODE by passing it to the Python interpreter.
2853 These allow macros to be defined, undefined, and listed
2857 Show operating system information about processes.
2860 List the inferiors currently under GDB's control.
2863 Switch focus to inferior number NUM.
2866 Detach from inferior number NUM.
2869 Kill inferior number NUM.
2873 set spu stop-on-load
2874 show spu stop-on-load
2875 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2877 set spu auto-flush-cache
2878 show spu auto-flush-cache
2879 Control whether to automatically flush the software-managed cache
2880 during Cell/B.E. debugging.
2882 set sh calling-convention
2883 show sh calling-convention
2884 Control the calling convention used when calling SH target functions.
2887 show debug timestamp
2888 Control display of timestamps with GDB debugging output.
2890 set disassemble-next-line
2891 show disassemble-next-line
2892 Control display of disassembled source lines or instructions when
2895 set remote noack-packet
2896 show remote noack-packet
2897 Set/show the use of remote protocol QStartNoAckMode packet. See above
2898 under "New remote packets."
2900 set remote query-attached-packet
2901 show remote query-attached-packet
2902 Control use of remote protocol `qAttached' (query-attached) packet.
2904 set remote read-siginfo-object
2905 show remote read-siginfo-object
2906 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2909 set remote write-siginfo-object
2910 show remote write-siginfo-object
2911 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2914 set remote reverse-continue
2915 show remote reverse-continue
2916 Control use of remote protocol 'bc' (reverse-continue) packet.
2918 set remote reverse-step
2919 show remote reverse-step
2920 Control use of remote protocol 'bs' (reverse-step) packet.
2922 set displaced-stepping
2923 show displaced-stepping
2924 Control displaced stepping mode. Displaced stepping is a way to
2925 single-step over breakpoints without removing them from the debuggee.
2926 Also known as "out-of-line single-stepping".
2929 show debug displaced
2930 Control display of debugging info for displaced stepping.
2932 maint set internal-error
2933 maint show internal-error
2934 Control what GDB does when an internal error is detected.
2936 maint set internal-warning
2937 maint show internal-warning
2938 Control what GDB does when an internal warning is detected.
2943 Use a wrapper program to launch programs for debugging.
2945 set multiple-symbols (all|ask|cancel)
2946 show multiple-symbols
2947 The value of this variable can be changed to adjust the debugger behavior
2948 when an expression or a breakpoint location contains an ambiguous symbol
2949 name (an overloaded function name, for instance).
2951 set breakpoint always-inserted
2952 show breakpoint always-inserted
2953 Keep breakpoints always inserted in the target, as opposed to inserting
2954 them when resuming the target, and removing them when the target stops.
2955 This option can improve debugger performance on slow remote targets.
2957 set arm fallback-mode (arm|thumb|auto)
2958 show arm fallback-mode
2959 set arm force-mode (arm|thumb|auto)
2961 These commands control how ARM GDB determines whether instructions
2962 are ARM or Thumb. The default for both settings is auto, which uses
2963 the current CPSR value for instructions without symbols; previous
2964 versions of GDB behaved as if "set arm fallback-mode arm".
2966 set disable-randomization
2967 show disable-randomization
2968 Standalone programs run with the virtual address space randomization enabled
2969 by default on some platforms. This option keeps the addresses stable across
2970 multiple debugging sessions.
2974 Control whether other threads are stopped or not when some thread hits
2979 Requests that asynchronous execution is enabled in the target, if available.
2980 In this case, it's possible to resume target in the background, and interact
2981 with GDB while the target is running. "show target-async" displays the
2982 current state of asynchronous execution of the target.
2984 set target-wide-charset
2985 show target-wide-charset
2986 The target-wide-charset is the name of the character set that GDB
2987 uses when printing characters whose type is wchar_t.
2989 set tcp auto-retry (on|off)
2991 set tcp connect-timeout
2992 show tcp connect-timeout
2993 These commands allow GDB to retry failed TCP connections to a remote stub
2994 with a specified timeout period; this is useful if the stub is launched
2995 in parallel with GDB but may not be ready to accept connections immediately.
2997 set libthread-db-search-path
2998 show libthread-db-search-path
2999 Control list of directories which GDB will search for appropriate
3002 set schedule-multiple (on|off)
3003 show schedule-multiple
3004 Allow GDB to resume all threads of all processes or only threads of
3005 the current process.
3009 Use more aggressive caching for accesses to the stack. This improves
3010 performance of remote debugging (particularly backtraces) without
3011 affecting correctness.
3013 set interactive-mode (on|off|auto)
3014 show interactive-mode
3015 Control whether GDB runs in interactive mode (on) or not (off).
3016 When in interactive mode, GDB waits for the user to answer all
3017 queries. Otherwise, GDB does not wait and assumes the default
3018 answer. When set to auto (the default), GDB determines which
3019 mode to use based on the stdin settings.
3024 For program forks, this is replaced by the new more generic `info
3025 inferiors' command. To list checkpoints, you can still use the
3026 `info checkpoints' command, which was an alias for the `info forks'
3030 Replaced by the new `inferior' command. To switch between
3031 checkpoints, you can still use the `restart' command, which was an
3032 alias for the `fork' command.
3035 This is removed, since some targets don't have a notion of
3036 processes. To switch between processes, you can still use the
3037 `inferior' command using GDB's own inferior number.
3040 For program forks, this is replaced by the new more generic `kill
3041 inferior' command. To delete a checkpoint, you can still use the
3042 `delete checkpoint' command, which was an alias for the `delete
3046 For program forks, this is replaced by the new more generic `detach
3047 inferior' command. To detach a checkpoint, you can still use the
3048 `detach checkpoint' command, which was an alias for the `detach
3051 * New native configurations
3053 x86/x86_64 Darwin i[34567]86-*-darwin*
3055 x86_64 MinGW x86_64-*-mingw*
3059 Lattice Mico32 lm32-*
3060 x86 DICOS i[34567]86-*-dicos*
3061 x86_64 DICOS x86_64-*-dicos*
3064 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3065 (mingw32ce) debugging.
3071 These commands were actually not implemented on any target.
3073 *** Changes in GDB 6.8
3075 * New native configurations
3077 NetBSD/hppa hppa*-*netbsd*
3078 Xtensa GNU/Linux xtensa*-*-linux*
3082 NetBSD/hppa hppa*-*-netbsd*
3083 Xtensa GNU/Lunux xtensa*-*-linux*
3085 * Change in command line behavior -- corefiles vs. process ids.
3087 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3088 attaching to process NUMBER fails, GDB no longer attempts to open a
3089 core file named NUMBER. Attaching to a program using the -c option
3090 is no longer supported. Instead, use the '-p' or '--pid' options.
3092 * GDB can now be built as a native debugger for debugging Windows x86
3093 (mingw32) Portable Executable (PE) programs.
3095 * Pending breakpoints no longer change their number when their address
3098 * GDB now supports breakpoints with multiple locations,
3099 including breakpoints on C++ constructors, inside C++ templates,
3100 and in inlined functions.
3102 * GDB's ability to debug optimized code has been improved. GDB more
3103 accurately identifies function bodies and lexical blocks that occupy
3104 more than one contiguous range of addresses.
3106 * Target descriptions can now describe registers for PowerPC.
3108 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3109 registers on PowerPC targets.
3111 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3112 targets even when the libthread_db library is not available.
3114 * The GDB remote stub, gdbserver, now supports the new file transfer
3115 commands (remote put, remote get, and remote delete).
3117 * The GDB remote stub, gdbserver, now supports run and attach in
3118 extended-remote mode.
3120 * hppa*64*-*-hpux11* target broken
3121 The debugger is unable to start a program and fails with the following
3122 error: "Error trying to get information about dynamic linker".
3123 The gdb-6.7 release is also affected.
3125 * GDB now supports the --enable-targets= configure option to allow
3126 building a single GDB executable that supports multiple remote
3127 target architectures.
3129 * GDB now supports debugging C and C++ programs which use the
3130 Decimal Floating Point extension. In addition, the PowerPC target
3131 now has a set of pseudo-registers to inspect decimal float values
3132 stored in two consecutive float registers.
3134 * The -break-insert MI command can optionally create pending
3137 * Improved support for debugging Ada
3138 Many improvements to the Ada language support have been made. These
3140 - Better support for Ada2005 interface types
3141 - Improved handling of arrays and slices in general
3142 - Better support for Taft-amendment types
3143 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3145 - Improved command completion in Ada
3148 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3153 set print frame-arguments (all|scalars|none)
3154 show print frame-arguments
3155 The value of this variable can be changed to control which argument
3156 values should be printed by the debugger when displaying a frame.
3161 Transfer files to and from a remote target, and delete remote files.
3168 Transfer files to and from a remote target, and delete remote files.
3170 * New remote packets
3177 Open, close, read, write, and delete files on the remote system.
3180 Attach to an existing process on the remote system, in extended-remote
3184 Run a new process on the remote system, in extended-remote mode.
3186 *** Changes in GDB 6.7
3188 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3189 bfd, libiberty and opcodes, as revealed by static analysis donated by
3190 Coverity, Inc. (http://scan.coverity.com).
3192 * When looking up multiply-defined global symbols, GDB will now prefer the
3193 symbol definition in the current shared library if it was built using the
3194 -Bsymbolic linker option.
3196 * When the Text User Interface (TUI) is not configured, GDB will now
3197 recognize the -tui command-line option and print a message that the TUI
3200 * The GDB remote stub, gdbserver, now has lower overhead for high
3201 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3203 * GDB for MIPS targets now autodetects whether a remote target provides
3204 32-bit or 64-bit register values.
3206 * Support for C++ member pointers has been improved.
3208 * GDB now understands XML target descriptions, which specify the
3209 target's overall architecture. GDB can read a description from
3210 a local file or over the remote serial protocol.
3212 * Vectors of single-byte data use a new integer type which is not
3213 automatically displayed as character or string data.
3215 * The /s format now works with the print command. It displays
3216 arrays of single-byte integers and pointers to single-byte integers
3219 * Target descriptions can now describe target-specific registers,
3220 for architectures which have implemented the support (currently
3221 only ARM, M68K, and MIPS).
3223 * GDB and the GDB remote stub, gdbserver, now support the XScale
3226 * The GDB remote stub, gdbserver, has been updated to support
3227 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3228 has been rewritten to use the standard GDB remote protocol.
3230 * GDB can now step into C++ functions which are called through thunks.
3232 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3234 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3235 layout. It also supports a TextSeg= and DataSeg= response when only
3236 segment base addresses (rather than offsets) are available.
3238 * The /i format now outputs any trailing branch delay slot instructions
3239 immediately following the last instruction within the count specified.
3241 * The GDB remote protocol "T" stop reply packet now supports a
3242 "library" response. Combined with the new "qXfer:libraries:read"
3243 packet, this response allows GDB to debug shared libraries on targets
3244 where the operating system manages the list of loaded libraries (e.g.
3245 Windows and SymbianOS).
3247 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3248 (DLLs) on Windows and Windows CE targets.
3250 * GDB now supports a faster verification that a .debug file matches its binary
3251 according to its build-id signature, if the signature is present.
3257 Enable or disable hardware flow control (RTS/CTS) on the serial port
3258 when debugging using remote targets.
3260 set mem inaccessible-by-default
3261 show mem inaccessible-by-default
3262 If the target supplies a memory map, for instance via the remote
3263 protocol's "qXfer:memory-map:read" packet, setting this variable
3264 prevents GDB from accessing memory outside the memory map. This
3265 is useful for targets with memory mapped registers or which react
3266 badly to accesses of unmapped address space.
3268 set breakpoint auto-hw
3269 show breakpoint auto-hw
3270 If the target supplies a memory map, for instance via the remote
3271 protocol's "qXfer:memory-map:read" packet, setting this variable
3272 lets GDB use hardware breakpoints automatically for memory regions
3273 where it can not use software breakpoints. This covers both the
3274 "break" command and internal breakpoints used for other commands
3275 including "next" and "finish".
3278 catch exception unhandled
3279 Stop the program execution when Ada exceptions are raised.
3282 Stop the program execution when an Ada assertion failed.
3286 Set an alternate system root for target files. This is a more
3287 general version of "set solib-absolute-prefix", which is now
3288 an alias to "set sysroot".
3291 Provide extended SPU facility status information. This set of
3292 commands is available only when debugging the Cell/B.E. SPU
3295 * New native configurations
3297 OpenBSD/sh sh*-*openbsd*
3300 unset tdesc filename
3302 Use the specified local file as an XML target description, and do
3303 not query the target for its built-in description.
3307 OpenBSD/sh sh*-*-openbsd*
3308 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3309 Toshiba Media Processor mep-elf
3311 * New remote packets
3314 Ignore the specified signals; pass them directly to the debugged program
3315 without stopping other threads or reporting them to GDB.
3317 qXfer:features:read:
3318 Read an XML target description from the target, which describes its
3323 Read or write contents of an spufs file on the target system. These
3324 packets are available only on the Cell/B.E. SPU architecture.
3326 qXfer:libraries:read:
3327 Report the loaded shared libraries. Combined with new "T" packet
3328 response, this packet allows GDB to debug shared libraries on
3329 targets where the operating system manages the list of loaded
3330 libraries (e.g. Windows and SymbianOS).
3334 Support for these obsolete configurations has been removed.
3342 i[34567]86-*-lynxos*
3343 i[34567]86-*-netware*
3344 i[34567]86-*-sco3.2v5*
3345 i[34567]86-*-sco3.2v4*
3347 i[34567]86-*-sysv4.2*
3350 i[34567]86-*-unixware2*
3351 i[34567]86-*-unixware*
3360 * Other removed features
3367 Various m68k-only ROM monitors.
3374 Various Renesas ROM monitors and debugging interfaces for SH and
3379 Support for a Macraigor serial interface to on-chip debugging.
3380 GDB does not directly support the newer parallel or USB
3385 A debug information format. The predecessor to DWARF 2 and
3386 DWARF 3, which are still supported.
3388 Support for the HP aCC compiler on HP-UX/PA-RISC
3390 SOM-encapsulated symbolic debugging information, automatic
3391 invocation of pxdb, and the aCC custom C++ ABI. This does not
3392 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3393 with aCC can still be debugged on an assembly level.
3395 MIPS ".pdr" sections
3397 A MIPS-specific format used to describe stack frame layout
3398 in debugging information.
3402 GDB could work with an older version of Guile to debug
3403 the interpreter and Scheme programs running in it.
3405 set mips stack-arg-size
3406 set mips saved-gpreg-size
3408 Use "set mips abi" to control parameter passing for MIPS.
3410 *** Changes in GDB 6.6
3415 Cell Broadband Engine SPU spu-elf
3417 * GDB can now be configured as a cross-debugger targeting native Windows
3418 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3419 running on a Windows system over TCP/IP to debug Windows programs.
3421 * The GDB remote stub, gdbserver, has been updated to support Windows and
3422 Cygwin debugging. Both single-threaded and multi-threaded programs are
3425 * The "set trust-readonly-sections" command works again. This command was
3426 broken in GDB 6.3, 6.4, and 6.5.
3428 * The "load" command now supports writing to flash memory, if the remote
3429 stub provides the required support.
3431 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3432 longer requires symbolic debug information (e.g. DWARF-2).
3437 unset substitute-path
3438 show substitute-path
3439 Manage a list of substitution rules that GDB uses to rewrite the name
3440 of the directories where the sources are located. This can be useful
3441 for instance when the sources were moved to a different location
3442 between compilation and debugging.
3446 Print each CLI command as it is executed. Each command is prefixed with
3447 a number of `+' symbols representing the nesting depth.
3448 The source command now has a `-v' option to enable the same feature.
3452 The ARM Demon monitor support (RDP protocol, "target rdp").
3454 Kernel Object Display, an embedded debugging feature which only worked with
3455 an obsolete version of Cisco IOS.
3457 The 'set download-write-size' and 'show download-write-size' commands.
3459 * New remote packets
3462 Tell a stub about GDB client features, and request remote target features.
3463 The first feature implemented is PacketSize, which allows the target to
3464 specify the size of packets it can handle - to minimize the number of
3465 packets required and improve performance when connected to a remote
3469 Fetch an OS auxilliary vector from the remote stub. This packet is a
3470 more efficient replacement for qPart:auxv:read.
3472 qXfer:memory-map:read:
3473 Fetch a memory map from the remote stub, including information about
3474 RAM, ROM, and flash memory devices.
3479 Erase and program a flash memory device.
3481 * Removed remote packets
3484 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3485 used it, and only gdbserver implemented it.
3487 *** Changes in GDB 6.5
3491 Renesas M32C/M16C m32c-elf
3493 Morpho Technologies ms1 ms1-elf
3497 init-if-undefined Initialize a convenience variable, but
3498 only if it doesn't already have a value.
3500 The following commands are presently only implemented for native GNU/Linux:
3502 checkpoint Save a snapshot of the program state.
3504 restart <n> Return the program state to a
3505 previously saved state.
3507 info checkpoints List currently saved checkpoints.
3509 delete-checkpoint <n> Delete a previously saved checkpoint.
3511 set|show detach-on-fork Tell gdb whether to detach from a newly
3512 forked process, or to keep debugging it.
3514 info forks List forks of the user program that
3515 are available to be debugged.
3517 fork <n> Switch to debugging one of several
3518 forks of the user program that are
3519 available to be debugged.
3521 delete-fork <n> Delete a fork from the list of forks
3522 that are available to be debugged (and
3523 kill the forked process).
3525 detach-fork <n> Delete a fork from the list of forks
3526 that are available to be debugged (and
3527 allow the process to continue).
3531 Morpho Technologies ms2 ms1-elf
3533 * Improved Windows host support
3535 GDB now builds as a cross debugger hosted on i686-mingw32, including
3536 native console support, and remote communications using either
3537 network sockets or serial ports.
3539 * Improved Modula-2 language support
3541 GDB can now print most types in the Modula-2 syntax. This includes:
3542 basic types, set types, record types, enumerated types, range types,
3543 pointer types and ARRAY types. Procedure var parameters are correctly
3544 printed and hexadecimal addresses and character constants are also
3545 written in the Modula-2 syntax. Best results can be obtained by using
3546 GNU Modula-2 together with the -gdwarf-2 command line option.
3550 The ARM rdi-share module.
3552 The Netware NLM debug server.
3554 *** Changes in GDB 6.4
3556 * New native configurations
3558 OpenBSD/arm arm*-*-openbsd*
3559 OpenBSD/mips64 mips64-*-openbsd*
3563 Morpho Technologies ms1 ms1-elf
3565 * New command line options
3567 --batch-silent As for --batch, but totally silent.
3568 --return-child-result The debugger will exist with the same value
3569 the child (debugged) program exited with.
3570 --eval-command COMMAND, -ex COMMAND
3571 Execute a single GDB CLI command. This may be
3572 specified multiple times and in conjunction
3573 with the --command (-x) option.
3575 * Deprecated commands removed
3577 The following commands, that were deprecated in 2000, have been
3581 set|show arm disassembly-flavor set|show arm disassembler
3582 othernames set arm disassembler
3583 set|show remotedebug set|show debug remote
3584 set|show archdebug set|show debug arch
3585 set|show eventdebug set|show debug event
3588 * New BSD user-level threads support
3590 It is now possible to debug programs using the user-level threads
3591 library on OpenBSD and FreeBSD. Currently supported (target)
3594 FreeBSD/amd64 x86_64-*-freebsd*
3595 FreeBSD/i386 i386-*-freebsd*
3596 OpenBSD/i386 i386-*-openbsd*
3598 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3599 are not yet supported.
3601 * New support for Matsushita MN10300 w/sim added
3602 (Work in progress). mn10300-elf.
3604 * REMOVED configurations and files
3606 VxWorks and the XDR protocol *-*-vxworks
3607 Motorola MCORE mcore-*-*
3608 National Semiconductor NS32000 ns32k-*-*
3610 * New "set print array-indexes" command
3612 After turning this setting "on", GDB prints the index of each element
3613 when displaying arrays. The default is "off" to preserve the previous
3616 * VAX floating point support
3618 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3620 * User-defined command support
3622 In addition to using $arg0..$arg9 for argument passing, it is now possible
3623 to use $argc to determine now many arguments have been passed. See the
3624 section on user-defined commands in the user manual for more information.
3626 *** Changes in GDB 6.3:
3628 * New command line option
3630 GDB now accepts -l followed by a number to set the timeout for remote
3633 * GDB works with GCC -feliminate-dwarf2-dups
3635 GDB now supports a more compact representation of DWARF-2 debug
3636 information using DW_FORM_ref_addr references. These are produced
3637 by GCC with the option -feliminate-dwarf2-dups and also by some
3638 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3639 to use -feliminate-dwarf2-dups.
3641 * Internationalization
3643 When supported by the host system, GDB will be built with
3644 internationalization (libintl). The task of marking up the sources is
3645 continued, we're looking forward to our first translation.
3649 Initial support for debugging programs compiled with the GNAT
3650 implementation of the Ada programming language has been integrated
3651 into GDB. In this release, support is limited to expression evaluation.
3653 * New native configurations
3655 GNU/Linux/m32r m32r-*-linux-gnu
3659 GDB's remote protocol now includes support for the 'p' packet. This
3660 packet is used to fetch individual registers from a remote inferior.
3662 * END-OF-LIFE registers[] compatibility module
3664 GDB's internal register infrastructure has been completely rewritten.
3665 The new infrastructure making possible the implementation of key new
3666 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3669 GDB 6.3 will be the last release to include the the registers[]
3670 compatibility module that allowed out-of-date configurations to
3671 continue to work. This change directly impacts the following
3681 powerpc bdm protocol
3683 Unless there is activity to revive these configurations, they will be
3684 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3686 * OBSOLETE configurations and files
3688 Configurations that have been declared obsolete in this release have
3689 been commented out. Unless there is activity to revive these
3690 configurations, the next release of GDB will have their sources
3691 permanently REMOVED.
3700 *** Changes in GDB 6.2.1:
3702 * MIPS `break main; run' gave an heuristic-fence-post warning
3704 When attempting to run even a simple program, a warning about
3705 heuristic-fence-post being hit would be reported. This problem has
3708 * MIPS IRIX 'long double' crashed GDB
3710 When examining a long double variable, GDB would get a segmentation
3711 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3712 IRIX long double values).
3716 A bug in the VAX stack code was causing problems with the "next"
3717 command. This problem has been fixed.
3719 *** Changes in GDB 6.2:
3721 * Fix for ``many threads''
3723 On GNU/Linux systems that use the NPTL threads library, a program
3724 rapidly creating and deleting threads would confuse GDB leading to the
3727 ptrace: No such process.
3728 thread_db_get_info: cannot get thread info: generic error
3730 This problem has been fixed.
3732 * "-async" and "-noasync" options removed.
3734 Support for the broken "-noasync" option has been removed (it caused
3737 * New ``start'' command.
3739 This command runs the program until the begining of the main procedure.
3741 * New BSD Kernel Data Access Library (libkvm) interface
3743 Using ``target kvm'' it is now possible to debug kernel core dumps and
3744 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3745 platforms. Currently supported (native-only) configurations are:
3747 FreeBSD/amd64 x86_64-*-freebsd*
3748 FreeBSD/i386 i?86-*-freebsd*
3749 NetBSD/i386 i?86-*-netbsd*
3750 NetBSD/m68k m68*-*-netbsd*
3751 NetBSD/sparc sparc-*-netbsd*
3752 OpenBSD/amd64 x86_64-*-openbsd*
3753 OpenBSD/i386 i?86-*-openbsd*
3754 OpenBSD/m68k m68*-openbsd*
3755 OpenBSD/sparc sparc-*-openbsd*
3757 * Signal trampoline code overhauled
3759 Many generic problems with GDB's signal handling code have been fixed.
3760 These include: backtraces through non-contiguous stacks; recognition
3761 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3762 call; backtrace through a signal trampoline; step into and out of
3763 signal handlers; and single-stepping in the signal trampoline.
3765 Please note that kernel bugs are a limiting factor here. These
3766 features have been shown to work on an s390 GNU/Linux system that
3767 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3769 * Cygwin support for DWARF 2 added.
3771 * New native configurations
3773 GNU/Linux/hppa hppa*-*-linux*
3774 OpenBSD/hppa hppa*-*-openbsd*
3775 OpenBSD/m68k m68*-*-openbsd*
3776 OpenBSD/m88k m88*-*-openbsd*
3777 OpenBSD/powerpc powerpc-*-openbsd*
3778 NetBSD/vax vax-*-netbsd*
3779 OpenBSD/vax vax-*-openbsd*
3781 * END-OF-LIFE frame compatibility module
3783 GDB's internal frame infrastructure has been completely rewritten.
3784 The new infrastructure making it possible to support key new features
3785 including DWARF 2 Call Frame Information. To aid in the task of
3786 migrating old configurations to this new infrastructure, a
3787 compatibility module, that allowed old configurations to continue to
3788 work, was also included.
3790 GDB 6.2 will be the last release to include this frame compatibility
3791 module. This change directly impacts the following configurations:
3801 Unless there is activity to revive these configurations, they will be
3802 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3804 * REMOVED configurations and files
3806 Sun 3, running SunOS 3 m68*-*-sunos3*
3807 Sun 3, running SunOS 4 m68*-*-sunos4*
3808 Sun 2, running SunOS 3 m68000-*-sunos3*
3809 Sun 2, running SunOS 4 m68000-*-sunos4*
3810 Motorola 680x0 running LynxOS m68*-*-lynxos*
3811 AT&T 3b1/Unix pc m68*-att-*
3812 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3813 decstation mips-dec-* mips-little-*
3814 riscos mips-*-riscos* mips-*-sysv*
3815 sonymips mips-sony-*
3816 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3818 *** Changes in GDB 6.1.1:
3820 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3822 The TUI (Text-mode User Interface) is now built as part of a default
3823 GDB configuration. It is enabled by either selecting the TUI with the
3824 command line option "-i=tui" or by running the separate "gdbtui"
3825 program. For more information on the TUI, see the manual "Debugging
3828 * Pending breakpoint support (also included in GDB 6.1)
3830 Support has been added to allow you to specify breakpoints in shared
3831 libraries that have not yet been loaded. If a breakpoint location
3832 cannot be found, and the "breakpoint pending" option is set to auto,
3833 GDB queries you if you wish to make the breakpoint pending on a future
3834 shared-library load. If and when GDB resolves the breakpoint symbol,
3835 the pending breakpoint is removed as one or more regular breakpoints
3838 Pending breakpoints are very useful for GCJ Java debugging.
3840 * Fixed ISO-C build problems
3842 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3843 non ISO-C code that stopped them being built using a more strict ISO-C
3844 compiler (e.g., IBM's C compiler).
3846 * Fixed build problem on IRIX 5
3848 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3849 wasn't able to compile compile on an IRIX 5 system.
3851 * Added execute permission to gdb/gdbserver/configure
3853 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3854 permission. This bug would cause configure to fail on a number of
3855 systems (Solaris, IRIX). Ref: server/519.
3857 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3859 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3860 has been updated to use constant array sizes.
3862 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3864 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3865 its generated DWARF Call Frame Info. This encoding was causing GDB to
3866 panic, that panic has been fixed. Ref: gdb/1628.
3868 * Fixed a problem when examining parameters in shared library code.
3870 When examining parameters in optimized shared library code generated
3871 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3872 not available''. GDB now correctly displays the variable's value.
3874 *** Changes in GDB 6.1:
3876 * Removed --with-mmalloc
3878 Support for the mmalloc memory manager has been removed, as it
3879 conflicted with the internal gdb byte cache.
3881 * Changes in AMD64 configurations
3883 The AMD64 target now includes the %cs and %ss registers. As a result
3884 the AMD64 remote protocol has changed; this affects the floating-point
3885 and SSE registers. If you rely on those registers for your debugging,
3886 you should upgrade gdbserver on the remote side.
3888 * Revised SPARC target
3890 The SPARC target has been completely revised, incorporating the
3891 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3892 support for LynxOS and SunOS 4 has been dropped. Calling functions
3893 from within GDB on operating systems with a non-executable stack
3894 (Solaris, OpenBSD) now works.
3898 GDB has a new C++ demangler which does a better job on the mangled
3899 names generated by current versions of g++. It also runs faster, so
3900 with this and other changes gdb should now start faster on large C++
3903 * DWARF 2 Location Expressions
3905 GDB support for location expressions has been extended to support function
3906 arguments and frame bases. Older versions of GDB could crash when they
3909 * C++ nested types and namespaces
3911 GDB's support for nested types and namespaces in C++ has been
3912 improved, especially if you use the DWARF 2 debugging format. (This
3913 is the default for recent versions of GCC on most platforms.)
3914 Specifically, if you have a class "Inner" defined within a class or
3915 namespace "Outer", then GDB realizes that the class's name is
3916 "Outer::Inner", not simply "Inner". This should greatly reduce the
3917 frequency of complaints about not finding RTTI symbols. In addition,
3918 if you are stopped at inside of a function defined within a namespace,
3919 GDB modifies its name lookup accordingly.
3921 * New native configurations
3923 NetBSD/amd64 x86_64-*-netbsd*
3924 OpenBSD/amd64 x86_64-*-openbsd*
3925 OpenBSD/alpha alpha*-*-openbsd*
3926 OpenBSD/sparc sparc-*-openbsd*
3927 OpenBSD/sparc64 sparc64-*-openbsd*
3929 * New debugging protocols
3931 M32R with SDI protocol m32r-*-elf*
3933 * "set prompt-escape-char" command deleted.
3935 The command "set prompt-escape-char" has been deleted. This command,
3936 and its very obscure effet on GDB's prompt, was never documented,
3937 tested, nor mentioned in the NEWS file.
3939 * OBSOLETE configurations and files
3941 Configurations that have been declared obsolete in this release have
3942 been commented out. Unless there is activity to revive these
3943 configurations, the next release of GDB will have their sources
3944 permanently REMOVED.
3946 Sun 3, running SunOS 3 m68*-*-sunos3*
3947 Sun 3, running SunOS 4 m68*-*-sunos4*
3948 Sun 2, running SunOS 3 m68000-*-sunos3*
3949 Sun 2, running SunOS 4 m68000-*-sunos4*
3950 Motorola 680x0 running LynxOS m68*-*-lynxos*
3951 AT&T 3b1/Unix pc m68*-att-*
3952 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3953 decstation mips-dec-* mips-little-*
3954 riscos mips-*-riscos* mips-*-sysv*
3955 sonymips mips-sony-*
3956 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3958 * REMOVED configurations and files
3960 SGI Irix-4.x mips-sgi-irix4 or iris4
3961 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3962 Z8000 simulator z8k-zilog-none or z8ksim
3963 Matsushita MN10200 w/simulator mn10200-*-*
3964 H8/500 simulator h8500-hitachi-hms or h8500hms
3965 HP/PA running BSD hppa*-*-bsd*
3966 HP/PA running OSF/1 hppa*-*-osf*
3967 HP/PA Pro target hppa*-*-pro*
3968 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3969 386BSD i[3456]86-*-bsd*
3970 Sequent family i[3456]86-sequent-sysv4*
3971 i[3456]86-sequent-sysv*
3972 i[3456]86-sequent-bsd*
3973 SPARC running LynxOS sparc-*-lynxos*
3974 SPARC running SunOS 4 sparc-*-sunos4*
3975 Tsqware Sparclet sparclet-*-*
3976 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3978 *** Changes in GDB 6.0:
3982 Support for debugging the Objective-C programming language has been
3983 integrated into GDB.
3985 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3987 DWARF 2's Call Frame Information makes available compiler generated
3988 information that more exactly describes the program's run-time stack.
3989 By using this information, GDB is able to provide more robust stack
3992 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3993 have been updated to use a new backtrace mechanism which includes
3994 DWARF 2 CFI support.
3998 GDB's remote protocol has been extended to include support for hosted
3999 file I/O (where the remote target uses GDB's file system). See GDB's
4000 remote protocol documentation for details.
4002 * All targets using the new architecture framework.
4004 All of GDB's targets have been updated to use the new internal
4005 architecture framework. The way is now open for future GDB releases
4006 to include cross-architecture native debugging support (i386 on amd64,
4009 * GNU/Linux's Thread Local Storage (TLS)
4011 GDB now includes support for for the GNU/Linux implementation of
4012 per-thread variables.
4014 * GNU/Linux's Native POSIX Thread Library (NPTL)
4016 GDB's thread code has been updated to work with either the new
4017 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4019 * Separate debug info.
4021 GDB, in conjunction with BINUTILS, now supports a mechanism for
4022 automatically loading debug information from a separate file. Instead
4023 of shipping full debug and non-debug versions of system libraries,
4024 system integrators can now instead ship just the stripped libraries
4025 and optional debug files.
4027 * DWARF 2 Location Expressions
4029 DWARF 2 Location Expressions allow the compiler to more completely
4030 describe the location of variables (even in optimized code) to the
4033 GDB now includes preliminary support for location expressions (support
4034 for DW_OP_piece is still missing).
4038 A number of long standing bugs that caused GDB to die while starting a
4039 Java application have been fixed. GDB's Java support is now
4040 considered "useable".
4042 * GNU/Linux support for fork, vfork, and exec.
4044 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4045 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4048 * GDB supports logging output to a file
4050 There are two new commands, "set logging" and "show logging", which can be
4051 used to capture GDB's output to a file.
4053 * The meaning of "detach" has changed for gdbserver
4055 The "detach" command will now resume the application, as documented. To
4056 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4059 * d10v, m68hc11 `regs' command deprecated
4061 The `info registers' command has been updated so that it displays the
4062 registers using a format identical to the old `regs' command.
4066 A new command, "maint set profile on/off", has been added. This command can
4067 be used to enable or disable profiling while running GDB, to profile a
4068 session or a set of commands. In addition there is a new configure switch,
4069 "--enable-profiling", which will cause GDB to be compiled with profiling
4070 data, for more informative profiling results.
4072 * Default MI syntax changed to "mi2".
4074 The default MI (machine interface) syntax, enabled by the command line
4075 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4076 "mi1", can be enabled by specifying the option "-i=mi1".
4078 Support for the original "mi0" syntax (included in GDB 5.0) has been
4081 Fix for gdb/192: removed extraneous space when displaying frame level.
4082 Fix for gdb/672: update changelist is now output in mi list format.
4083 Fix for gdb/702: a -var-assign that updates the value now shows up
4084 in a subsequent -var-update.
4086 * New native configurations.
4088 FreeBSD/amd64 x86_64-*-freebsd*
4090 * Multi-arched targets.
4092 HP/PA HPUX11 hppa*-*-hpux*
4093 Renesas M32R/D w/simulator m32r-*-elf*
4095 * OBSOLETE configurations and files
4097 Configurations that have been declared obsolete in this release have
4098 been commented out. Unless there is activity to revive these
4099 configurations, the next release of GDB will have their sources
4100 permanently REMOVED.
4102 Z8000 simulator z8k-zilog-none or z8ksim
4103 Matsushita MN10200 w/simulator mn10200-*-*
4104 H8/500 simulator h8500-hitachi-hms or h8500hms
4105 HP/PA running BSD hppa*-*-bsd*
4106 HP/PA running OSF/1 hppa*-*-osf*
4107 HP/PA Pro target hppa*-*-pro*
4108 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4109 Sequent family i[3456]86-sequent-sysv4*
4110 i[3456]86-sequent-sysv*
4111 i[3456]86-sequent-bsd*
4112 Tsqware Sparclet sparclet-*-*
4113 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4115 * REMOVED configurations and files
4118 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4119 IBM AIX PS/2 i[3456]86-*-aix
4120 i386 running Mach 3.0 i[3456]86-*-mach3*
4121 i386 running Mach i[3456]86-*-mach*
4122 i386 running OSF/1 i[3456]86-*osf1mk*
4123 HP/Apollo 68k Family m68*-apollo*-sysv*,
4125 m68*-hp-bsd*, m68*-hp-hpux*
4126 Argonaut Risc Chip (ARC) arc-*-*
4127 Mitsubishi D30V d30v-*-*
4128 Fujitsu FR30 fr30-*-elf*
4129 OS/9000 i[34]86-*-os9k
4130 I960 with MON960 i960-*-coff
4132 * MIPS $fp behavior changed
4134 The convenience variable $fp, for the MIPS, now consistently returns
4135 the address of the current frame's base. Previously, depending on the
4136 context, $fp could refer to either $sp or the current frame's base
4137 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4138 The GNU Source-Level Debugger''.
4140 *** Changes in GDB 5.3:
4142 * GNU/Linux shared library multi-threaded performance improved.
4144 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4145 `/proc', in preference to `ptrace' for memory reads. This may result
4146 in an improvement in the start-up time of multi-threaded, shared
4147 library applications when run under GDB. One GDB user writes: ``loads
4148 shared libs like mad''.
4150 * ``gdbserver'' now supports multi-threaded applications on some targets
4152 Support for debugging multi-threaded applications which use
4153 the GNU/Linux LinuxThreads package has been added for
4154 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4155 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4157 * GDB now supports C/C++ preprocessor macros.
4159 GDB now expands preprocessor macro invocations in C/C++ expressions,
4160 and provides various commands for showing macro definitions and how
4163 The new command `macro expand EXPRESSION' expands any macro
4164 invocations in expression, and shows the result.
4166 The new command `show macro MACRO-NAME' shows the definition of the
4167 macro named MACRO-NAME, and where it was defined.
4169 Most compilers don't include information about macros in the debugging
4170 information by default. In GCC 3.1, for example, you need to compile
4171 your program with the options `-gdwarf-2 -g3'. If the macro
4172 information is present in the executable, GDB will read it.
4174 * Multi-arched targets.
4176 DEC Alpha (partial) alpha*-*-*
4177 DEC VAX (partial) vax-*-*
4179 National Semiconductor NS32000 (partial) ns32k-*-*
4180 Motorola 68000 (partial) m68k-*-*
4181 Motorola MCORE mcore-*-*
4185 Fujitsu FRV architecture added by Red Hat frv*-*-*
4188 * New native configurations
4190 Alpha NetBSD alpha*-*-netbsd*
4191 SH NetBSD sh*-*-netbsdelf*
4192 MIPS NetBSD mips*-*-netbsd*
4193 UltraSPARC NetBSD sparc64-*-netbsd*
4195 * OBSOLETE configurations and files
4197 Configurations that have been declared obsolete in this release have
4198 been commented out. Unless there is activity to revive these
4199 configurations, the next release of GDB will have their sources
4200 permanently REMOVED.
4202 Mitsubishi D30V d30v-*-*
4203 OS/9000 i[34]86-*-os9k
4204 IBM AIX PS/2 i[3456]86-*-aix
4205 Fujitsu FR30 fr30-*-elf*
4206 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4207 Argonaut Risc Chip (ARC) arc-*-*
4208 i386 running Mach 3.0 i[3456]86-*-mach3*
4209 i386 running Mach i[3456]86-*-mach*
4210 i386 running OSF/1 i[3456]86-*osf1mk*
4211 HP/Apollo 68k Family m68*-apollo*-sysv*,
4213 m68*-hp-bsd*, m68*-hp-hpux*
4214 I960 with MON960 i960-*-coff
4216 * OBSOLETE languages
4218 CHILL, a Pascal like language used by telecommunications companies.
4220 * REMOVED configurations and files
4222 AMD 29k family via UDI a29k-amd-udi, udi29k
4223 A29K VxWorks a29k-*-vxworks
4224 AMD 29000 embedded, using EBMON a29k-none-none
4225 AMD 29000 embedded with COFF a29k-none-coff
4226 AMD 29000 embedded with a.out a29k-none-aout
4228 testsuite/gdb.hp/gdb.threads-hp/ directory
4230 * New command "set max-user-call-depth <nnn>"
4232 This command allows the user to limit the call depth of user-defined
4233 commands. The default is 1024.
4235 * Changes in FreeBSD/i386 native debugging.
4237 Support for the "generate-core-file" has been added.
4239 * New commands "dump", "append", and "restore".
4241 These commands allow data to be copied from target memory
4242 to a bfd-format or binary file (dump and append), and back
4243 from a file into memory (restore).
4245 * Improved "next/step" support on multi-processor Alpha Tru64.
4247 The previous single-step mechanism could cause unpredictable problems,
4248 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4249 of a software single-step mechanism prevents this.
4251 *** Changes in GDB 5.2.1:
4259 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4260 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4261 Fix, by Joel Brobecker imported from mainline.
4263 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4264 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4265 Fix, by Fred Fish, imported from mainline.
4267 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4268 Surprisingly enough, it works now.
4269 By Michal Ludvig, imported from mainline.
4271 i386 hardware watchpoint support:
4272 avoid misses on second run for some targets.
4273 By Pierre Muller, imported from mainline.
4275 *** Changes in GDB 5.2:
4277 * New command "set trust-readonly-sections on[off]".
4279 This command is a hint that tells gdb that read-only sections
4280 really are read-only (ie. that their contents will not change).
4281 In this mode, gdb will go to the object file rather than the
4282 target to read memory from read-only sections (such as ".text").
4283 This can be a significant performance improvement on some
4284 (notably embedded) targets.
4286 * New command "generate-core-file" (or "gcore").
4288 This new gdb command allows the user to drop a core file of the child
4289 process state at any time. So far it's been implemented only for
4290 GNU/Linux and Solaris, but should be relatively easily ported to other
4291 hosts. Argument is core file name (defaults to core.<pid>).
4293 * New command line option
4295 GDB now accepts --pid or -p followed by a process id.
4297 * Change in command line behavior -- corefiles vs. process ids.
4299 There is a subtle behavior in the way in which GDB handles
4300 command line arguments. The first non-flag argument is always
4301 a program to debug, but the second non-flag argument may either
4302 be a corefile or a process id. Previously, GDB would attempt to
4303 open the second argument as a corefile, and if that failed, would
4304 issue a superfluous error message and then attempt to attach it as
4305 a process. Now, if the second argument begins with a non-digit,
4306 it will be treated as a corefile. If it begins with a digit,
4307 GDB will attempt to attach it as a process, and if no such process
4308 is found, will then attempt to open it as a corefile.
4310 * Changes in ARM configurations.
4312 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4313 configuration is fully multi-arch.
4315 * New native configurations
4317 ARM NetBSD arm*-*-netbsd*
4318 x86 OpenBSD i[3456]86-*-openbsd*
4319 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4320 Sparc64 running FreeBSD sparc64-*-freebsd*
4324 Sanyo XStormy16 xstormy16-elf
4326 * OBSOLETE configurations and files
4328 Configurations that have been declared obsolete in this release have
4329 been commented out. Unless there is activity to revive these
4330 configurations, the next release of GDB will have their sources
4331 permanently REMOVED.
4333 AMD 29k family via UDI a29k-amd-udi, udi29k
4334 A29K VxWorks a29k-*-vxworks
4335 AMD 29000 embedded, using EBMON a29k-none-none
4336 AMD 29000 embedded with COFF a29k-none-coff
4337 AMD 29000 embedded with a.out a29k-none-aout
4339 testsuite/gdb.hp/gdb.threads-hp/ directory
4341 * REMOVED configurations and files
4343 TI TMS320C80 tic80-*-*
4345 PowerPC Solaris powerpcle-*-solaris*
4346 PowerPC Windows NT powerpcle-*-cygwin32
4347 PowerPC Netware powerpc-*-netware*
4348 Harris/CXUX m88k m88*-harris-cxux*
4349 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4350 ns32k-utek-sysv* ns32k-utek-*
4351 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4352 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4353 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4354 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4355 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4357 * Changes to command line processing
4359 The new `--args' feature can be used to specify command-line arguments
4360 for the inferior from gdb's command line.
4362 * Changes to key bindings
4364 There is a new `operate-and-get-next' function bound to `C-o'.
4366 *** Changes in GDB 5.1.1
4368 Fix compile problem on DJGPP.
4370 Fix a problem with floating-point registers on the i386 being
4373 Fix to stop GDB crashing on .debug_str debug info.
4375 Numerous documentation fixes.
4377 Numerous testsuite fixes.
4379 *** Changes in GDB 5.1:
4381 * New native configurations
4383 Alpha FreeBSD alpha*-*-freebsd*
4384 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4385 MIPS GNU/Linux mips*-*-linux*
4386 MIPS SGI Irix 6.x mips*-sgi-irix6*
4387 ia64 AIX ia64-*-aix*
4388 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4392 Motorola 68HC11 and 68HC12 m68hc11-elf
4394 UltraSparc running GNU/Linux sparc64-*-linux*
4396 * OBSOLETE configurations and files
4398 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4399 Harris/CXUX m88k m88*-harris-cxux*
4400 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4401 ns32k-utek-sysv* ns32k-utek-*
4402 TI TMS320C80 tic80-*-*
4404 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4405 PowerPC Solaris powerpcle-*-solaris*
4406 PowerPC Windows NT powerpcle-*-cygwin32
4407 PowerPC Netware powerpc-*-netware*
4408 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4409 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4410 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4411 Apple Macintosh (MPW) host N/A
4413 stuff.c (Program to stuff files into a specially prepared space in kdb)
4414 kdb-start.c (Main loop for the standalone kernel debugger)
4416 Configurations that have been declared obsolete in this release have
4417 been commented out. Unless there is activity to revive these
4418 configurations, the next release of GDB will have their sources
4419 permanently REMOVED.
4421 * REMOVED configurations and files
4423 Altos 3068 m68*-altos-*
4424 Convex c1-*-*, c2-*-*
4426 ARM RISCix arm-*-* (as host)
4430 * GDB has been converted to ISO C.
4432 GDB's source code has been converted to ISO C. In particular, the
4433 sources are fully protoized, and rely on standard headers being
4438 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4440 * The MI enabled by default.
4442 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4443 revised and enabled by default. Packages which use GDB as a debugging
4444 engine behind a UI or another front end are encouraged to switch to
4445 using the GDB/MI interface, instead of the old annotations interface
4446 which is now deprecated.
4448 * Support for debugging Pascal programs.
4450 GDB now includes support for debugging Pascal programs. The following
4451 main features are supported:
4453 - Pascal-specific data types such as sets;
4455 - automatic recognition of Pascal sources based on file-name
4458 - Pascal-style display of data types, variables, and functions;
4460 - a Pascal expression parser.
4462 However, some important features are not yet supported.
4464 - Pascal string operations are not supported at all;
4466 - there are some problems with boolean types;
4468 - Pascal type hexadecimal constants are not supported
4469 because they conflict with the internal variables format;
4471 - support for Pascal objects and classes is not full yet;
4473 - unlike Pascal, GDB is case-sensitive for symbol names.
4475 * Changes in completion.
4477 Commands such as `shell', `run' and `set args', which pass arguments
4478 to inferior programs, now complete on file names, similar to what
4479 users expect at the shell prompt.
4481 Commands which accept locations, such as `disassemble', `print',
4482 `breakpoint', `until', etc. now complete on filenames as well as
4483 program symbols. Thus, if you type "break foob TAB", and the source
4484 files linked into the programs include `foobar.c', that file name will
4485 be one of the candidates for completion. However, file names are not
4486 considered for completion after you typed a colon that delimits a file
4487 name from a name of a function in that file, as in "break foo.c:bar".
4489 `set demangle-style' completes on available demangling styles.
4491 * New platform-independent commands:
4493 It is now possible to define a post-hook for a command as well as a
4494 hook that runs before the command. For more details, see the
4495 documentation of `hookpost' in the GDB manual.
4497 * Changes in GNU/Linux native debugging.
4499 Support for debugging multi-threaded programs has been completely
4500 revised for all platforms except m68k and sparc. You can now debug as
4501 many threads as your system allows you to have.
4503 Attach/detach is supported for multi-threaded programs.
4505 Support for SSE registers was added for x86. This doesn't work for
4506 multi-threaded programs though.
4508 * Changes in MIPS configurations.
4510 Multi-arch support is enabled for all MIPS configurations.
4512 GDB can now be built as native debugger on SGI Irix 6.x systems for
4513 debugging n32 executables. (Debugging 64-bit executables is not yet
4516 * Unified support for hardware watchpoints in all x86 configurations.
4518 Most (if not all) native x86 configurations support hardware-assisted
4519 breakpoints and watchpoints in a unified manner. This support
4520 implements debug register sharing between watchpoints, which allows to
4521 put a virtually infinite number of watchpoints on the same address,
4522 and also supports watching regions up to 16 bytes with several debug
4525 The new maintenance command `maintenance show-debug-regs' toggles
4526 debugging print-outs in functions that insert, remove, and test
4527 watchpoints and hardware breakpoints.
4529 * Changes in the DJGPP native configuration.
4531 New command ``info dos sysinfo'' displays assorted information about
4532 the CPU, OS, memory, and DPMI server.
4534 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4535 display information about segment descriptors stored in GDT, LDT, and
4538 New commands ``info dos pde'' and ``info dos pte'' display entries
4539 from Page Directory and Page Tables (for now works with CWSDPMI only).
4540 New command ``info dos address-pte'' displays the Page Table entry for
4541 a given linear address.
4543 GDB can now pass command lines longer than 126 characters to the
4544 program being debugged (requires an update to the libdbg.a library
4545 which is part of the DJGPP development kit).
4547 DWARF2 debug info is now supported.
4549 It is now possible to `step' and `next' through calls to `longjmp'.
4551 * Changes in documentation.
4553 All GDB documentation was converted to GFDL, the GNU Free
4554 Documentation License.
4556 Tracepoints-related commands are now fully documented in the GDB
4559 TUI, the Text-mode User Interface, is now documented in the manual.
4561 Tracepoints-related commands are now fully documented in the GDB
4564 The "GDB Internals" manual now has an index. It also includes
4565 documentation of `ui_out' functions, GDB coding standards, x86
4566 hardware watchpoints, and memory region attributes.
4568 * GDB's version number moved to ``version.in''
4570 The Makefile variable VERSION has been replaced by the file
4571 ``version.in''. People creating GDB distributions should update the
4572 contents of this file.
4576 GUD support is now a standard part of the EMACS distribution.
4578 *** Changes in GDB 5.0:
4580 * Improved support for debugging FP programs on x86 targets
4582 Unified and much-improved support for debugging floating-point
4583 programs on all x86 targets. In particular, ``info float'' now
4584 displays the FP registers in the same format on all x86 targets, with
4585 greater level of detail.
4587 * Improvements and bugfixes in hardware-assisted watchpoints
4589 It is now possible to watch array elements, struct members, and
4590 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4591 on x86 targets no longer erroneously trigger when the address is
4594 * Improvements in the native DJGPP version of GDB
4596 The distribution now includes all the scripts and auxiliary files
4597 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4598 machines ``out of the box''.
4600 The DJGPP version can now debug programs that use signals. It is
4601 possible to catch signals that happened in the debuggee, deliver
4602 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4603 would kill the program being debugged.) Programs that hook hardware
4604 interrupts (keyboard, timer, etc.) can also be debugged.
4606 It is now possible to debug DJGPP programs that redirect their
4607 standard handles or switch them to raw (as opposed to cooked) mode, or
4608 even close them. The command ``run < foo > bar'' works as expected,
4609 and ``info terminal'' reports useful information about the debuggee's
4610 terminal, including raw/cooked mode, redirection, etc.
4612 The DJGPP version now uses termios functions for console I/O, which
4613 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4616 DOS-style file names with drive letters are now fully supported by
4619 It is now possible to debug DJGPP programs that switch their working
4620 directory. It is also possible to rerun the debuggee any number of
4621 times without restarting GDB; thus, you can use the same setup,
4622 breakpoints, etc. for many debugging sessions.
4624 * New native configurations
4626 ARM GNU/Linux arm*-*-linux*
4627 PowerPC GNU/Linux powerpc-*-linux*
4631 Motorola MCore mcore-*-*
4632 x86 VxWorks i[3456]86-*-vxworks*
4633 PowerPC VxWorks powerpc-*-vxworks*
4634 TI TMS320C80 tic80-*-*
4636 * OBSOLETE configurations
4638 Altos 3068 m68*-altos-*
4639 Convex c1-*-*, c2-*-*
4641 ARM RISCix arm-*-* (as host)
4644 Configurations that have been declared obsolete will be commented out,
4645 but the code will be left in place. If there is no activity to revive
4646 these configurations before the next release of GDB, the sources will
4647 be permanently REMOVED.
4649 * Gould support removed
4651 Support for the Gould PowerNode and NP1 has been removed.
4653 * New features for SVR4
4655 On SVR4 native platforms (such as Solaris), if you attach to a process
4656 without first loading a symbol file, GDB will now attempt to locate and
4657 load symbols from the running process's executable file.
4659 * Many C++ enhancements
4661 C++ support has been greatly improved. Overload resolution now works properly
4662 in almost all cases. RTTI support is on the way.
4664 * Remote targets can connect to a sub-program
4666 A popen(3) style serial-device has been added. This device starts a
4667 sub-process (such as a stand-alone simulator) and then communicates
4668 with that. The sub-program to run is specified using the syntax
4669 ``|<program> <args>'' vis:
4671 (gdb) set remotedebug 1
4672 (gdb) target extended-remote |mn10300-elf-sim program-args
4674 * MIPS 64 remote protocol
4676 A long standing bug in the mips64 remote protocol where by GDB
4677 expected certain 32 bit registers (ex SR) to be transfered as 32
4678 instead of 64 bits has been fixed.
4680 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4681 added to provide backward compatibility with older versions of GDB.
4683 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4685 The command ``set remotebinarydownload'' command has been replaced by
4686 ``set remote X-packet''. Other commands in ``set remote'' family
4687 include ``set remote P-packet''.
4689 * Breakpoint commands accept ranges.
4691 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4692 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4693 ``tracepoint passcount'' also accepts a range of tracepoints.
4695 * ``apropos'' command added.
4697 The ``apropos'' command searches through command names and
4698 documentation strings, printing out matches, making it much easier to
4699 try to find a command that does what you are looking for.
4703 A new machine oriented interface (MI) has been added to GDB. This
4704 interface is designed for debug environments running GDB as a separate
4705 process. This is part of the long term libGDB project. See the
4706 "GDB/MI" chapter of the GDB manual for further information. It can be
4707 enabled by configuring with:
4709 .../configure --enable-gdbmi
4711 *** Changes in GDB-4.18:
4713 * New native configurations
4715 HP-UX 10.20 hppa*-*-hpux10.20
4716 HP-UX 11.x hppa*-*-hpux11.0*
4717 M68K GNU/Linux m68*-*-linux*
4721 Fujitsu FR30 fr30-*-elf*
4722 Intel StrongARM strongarm-*-*
4723 Mitsubishi D30V d30v-*-*
4725 * OBSOLETE configurations
4727 Gould PowerNode, NP1 np1-*-*, pn-*-*
4729 Configurations that have been declared obsolete will be commented out,
4730 but the code will be left in place. If there is no activity to revive
4731 these configurations before the next release of GDB, the sources will
4732 be permanently REMOVED.
4736 As a compatibility experiment, GDB's source files buildsym.h and
4737 buildsym.c have been converted to pure standard C, no longer
4738 containing any K&R compatibility code. We believe that all systems in
4739 use today either come with a standard C compiler, or have a GCC port
4740 available. If this is not true, please report the affected
4742 information about getting a standard C compiler if you don't have one
4747 GDB now uses readline 2.2.
4749 * set extension-language
4751 You can now control the mapping between filename extensions and source
4752 languages by using the `set extension-language' command. For instance,
4753 you can ask GDB to treat .c files as C++ by saying
4754 set extension-language .c c++
4755 The command `info extensions' lists all of the recognized extensions
4756 and their associated languages.
4758 * Setting processor type for PowerPC and RS/6000
4760 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4761 you can use the `set processor' command to specify what variant of the
4762 PowerPC family you are debugging. The command
4766 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4767 following PowerPC and RS6000 variants:
4769 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4770 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4772 403GC IBM PowerPC 403GC
4773 505 Motorola PowerPC 505
4774 860 Motorola PowerPC 860 or 850
4775 601 Motorola PowerPC 601
4776 602 Motorola PowerPC 602
4777 603 Motorola/IBM PowerPC 603 or 603e
4778 604 Motorola PowerPC 604 or 604e
4779 750 Motorola/IBM PowerPC 750 or 750
4781 At the moment, this command just tells GDB what to name the
4782 special-purpose processor registers. Since almost all the affected
4783 registers are inaccessible to user-level programs, this command is
4784 only useful for remote debugging in its present form.
4788 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4789 more extensive support for HP-UX. Added features include shared
4790 library support, kernel threads and hardware watchpoints for 11.00,
4791 support for HP's ANSI C and C++ compilers, and a compatibility mode
4792 for xdb and dbx commands.
4796 HP's donation includes the new concept of catchpoints, which is a
4797 generalization of the old catch command. On HP-UX, it is now possible
4798 to catch exec, fork, and vfork, as well as library loading.
4800 This means that the existing catch command has changed; its first
4801 argument now specifies the type of catch to be set up. See the
4802 output of "help catch" for a list of catchpoint types.
4804 * Debugging across forks
4806 On HP-UX, you can choose which process to debug when a fork() happens
4811 HP has donated a curses-based terminal user interface (TUI). To get
4812 it, build with --enable-tui. Although this can be enabled for any
4813 configuration, at present it only works for native HP debugging.
4815 * GDB remote protocol additions
4817 A new protocol packet 'X' that writes binary data is now available.
4818 Default behavior is to try 'X', then drop back to 'M' if the stub
4819 fails to respond. The settable variable `remotebinarydownload'
4820 allows explicit control over the use of 'X'.
4822 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4823 full 64-bit address. The command
4825 set remoteaddresssize 32
4827 can be used to revert to the old behaviour. For existing remote stubs
4828 the change should not be noticed, as the additional address information
4831 In order to assist in debugging stubs, you may use the maintenance
4832 command `packet' to send any text string to the stub. For instance,
4834 maint packet heythere
4836 sends the packet "$heythere#<checksum>". Note that it is very easy to
4837 disrupt a debugging session by sending the wrong packet at the wrong
4840 The compare-sections command allows you to compare section data on the
4841 target to what is in the executable file without uploading or
4842 downloading, by comparing CRC checksums.
4844 * Tracing can collect general expressions
4846 You may now collect general expressions at tracepoints. This requires
4847 further additions to the target-side stub; see tracepoint.c and
4848 doc/agentexpr.texi for further details.
4850 * mask-address variable for Mips
4852 For Mips targets, you may control the zeroing of the upper 32 bits of
4853 a 64-bit address by entering `set mask-address on'. This is mainly
4854 of interest to users of embedded R4xxx and R5xxx processors.
4856 * Higher serial baud rates
4858 GDB's serial code now allows you to specify baud rates 57600, 115200,
4859 230400, and 460800 baud. (Note that your host system may not be able
4860 to achieve all of these rates.)
4864 The i960 configuration now includes an initial implementation of a
4865 builtin simulator, contributed by Jim Wilson.
4868 *** Changes in GDB-4.17:
4870 * New native configurations
4872 Alpha GNU/Linux alpha*-*-linux*
4873 Unixware 2.x i[3456]86-unixware2*
4874 Irix 6.x mips*-sgi-irix6*
4875 PowerPC GNU/Linux powerpc-*-linux*
4876 PowerPC Solaris powerpcle-*-solaris*
4877 Sparc GNU/Linux sparc-*-linux*
4878 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4882 Argonaut Risc Chip (ARC) arc-*-*
4883 Hitachi H8/300S h8300*-*-*
4884 Matsushita MN10200 w/simulator mn10200-*-*
4885 Matsushita MN10300 w/simulator mn10300-*-*
4886 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4887 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4888 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4889 Mitsubishi D10V w/simulator d10v-*-*
4890 Mitsubishi M32R/D w/simulator m32r-*-elf*
4891 Tsqware Sparclet sparclet-*-*
4892 NEC V850 w/simulator v850-*-*
4894 * New debugging protocols
4896 ARM with RDI protocol arm*-*-*
4897 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4898 DDB and LSI variants of PMON protocol mips*-*-*
4899 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4900 PowerPC with SDS protocol powerpc{,le}-*-eabi
4901 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4905 All configurations can now understand and use the DWARF 2 debugging
4906 format. The choice is automatic, if the symbol file contains DWARF 2
4911 GDB now includes basic Java language support. This support is
4912 only useful with Java compilers that produce native machine code.
4914 * solib-absolute-prefix and solib-search-path
4916 For SunOS and SVR4 shared libraries, you may now set the prefix for
4917 loading absolute shared library symbol files, and the search path for
4918 locating non-absolute shared library symbol files.
4920 * Live range splitting
4922 GDB can now effectively debug code for which GCC has performed live
4923 range splitting as part of its optimization. See gdb/doc/LRS for
4924 more details on the expected format of the stabs information.
4928 GDB's support for the GNU Hurd, including thread debugging, has been
4929 updated to work with current versions of the Hurd.
4933 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4934 instruction set. ARM GDB automatically detects when Thumb
4935 instructions are in use, and adjusts disassembly and backtracing
4940 GDB's MIPS target configurations now handle the MIP16 16-bit
4945 GDB now includes support for overlays; if an executable has been
4946 linked such that multiple sections are based at the same address, GDB
4947 will decide which section to use for symbolic info. You can choose to
4948 control the decision manually, using overlay commands, or implement
4949 additional target-side support and use "overlay load-target" to bring
4950 in the overlay mapping. Do "help overlay" for more detail.
4954 The command "info symbol <address>" displays information about
4955 the symbol at the specified address.
4959 The standard remote protocol now includes an extension that allows
4960 asynchronous collection and display of trace data. This requires
4961 extensive support in the target-side debugging stub. Tracing mode
4962 includes a new interaction mode in GDB and new commands: see the
4963 file tracepoint.c for more details.
4967 Configurations for embedded MIPS now include a simulator contributed
4968 by Cygnus Solutions. The simulator supports the instruction sets
4969 of most MIPS variants.
4973 Sparc configurations may now include the ERC32 simulator contributed
4974 by the European Space Agency. The simulator is not built into
4975 Sparc targets by default; configure with --enable-sim to include it.
4979 For target configurations that may include multiple variants of a
4980 basic architecture (such as MIPS and SH), you may now set the
4981 architecture explicitly. "set arch" sets, "info arch" lists
4982 the possible architectures.
4984 *** Changes in GDB-4.16:
4986 * New native configurations
4988 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4989 M68K NetBSD m68k-*-netbsd*
4990 PowerPC AIX 4.x powerpc-*-aix*
4991 PowerPC MacOS powerpc-*-macos*
4992 PowerPC Windows NT powerpcle-*-cygwin32
4993 RS/6000 AIX 4.x rs6000-*-aix4*
4997 ARM with RDP protocol arm-*-*
4998 I960 with MON960 i960-*-coff
4999 MIPS VxWorks mips*-*-vxworks*
5000 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5001 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5003 Matra Sparclet sparclet-*-*
5007 The powerpc-eabi configuration now includes the PSIM simulator,
5008 contributed by Andrew Cagney, with assistance from Mike Meissner.
5009 PSIM is a very elaborate model of the PowerPC, including not only
5010 basic instruction set execution, but also details of execution unit
5011 performance and I/O hardware. See sim/ppc/README for more details.
5015 GDB now works with Solaris 2.5.
5017 * Windows 95/NT native
5019 GDB will now work as a native debugger on Windows 95 and Windows NT.
5020 To build it from source, you must use the "gnu-win32" environment,
5021 which uses a DLL to emulate enough of Unix to run the GNU tools.
5022 Further information, binaries, and sources are available at
5023 ftp.cygnus.com, under pub/gnu-win32.
5025 * dont-repeat command
5027 If a user-defined command includes the command `dont-repeat', then the
5028 command will not be repeated if the user just types return. This is
5029 useful if the command is time-consuming to run, so that accidental
5030 extra keystrokes don't run the same command many times.
5032 * Send break instead of ^C
5034 The standard remote protocol now includes an option to send a break
5035 rather than a ^C to the target in order to interrupt it. By default,
5036 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5038 * Remote protocol timeout
5040 The standard remote protocol includes a new variable `remotetimeout'
5041 that allows you to set the number of seconds before GDB gives up trying
5042 to read from the target. The default value is 2.
5044 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5046 By default GDB will automatically keep track of objects as they are
5047 loaded and unloaded by the dynamic linker. By using the command `set
5048 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5049 when shared library events occur, thus allowing you to set breakpoints
5050 in shared libraries which are explicitly loaded by the inferior.
5052 Note this feature does not work on hpux8. On hpux9 you must link
5053 /usr/lib/end.o into your program. This feature should work
5054 automatically on hpux10.
5056 * Irix 5.x hardware watchpoint support
5058 Irix 5 configurations now support the use of hardware watchpoints.
5060 * Mips protocol "SYN garbage limit"
5062 When debugging a Mips target using the `target mips' protocol, you
5063 may set the number of characters that GDB will ignore by setting
5064 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5065 every character. The default value is 1050.
5067 * Recording and replaying remote debug sessions
5069 If you set `remotelogfile' to the name of a file, gdb will write to it
5070 a recording of a remote debug session. This recording may then be
5071 replayed back to gdb using "gdbreplay". See gdbserver/README for
5072 details. This is useful when you have a problem with GDB while doing
5073 remote debugging; you can make a recording of the session and send it
5074 to someone else, who can then recreate the problem.
5076 * Speedups for remote debugging
5078 GDB includes speedups for downloading and stepping MIPS systems using
5079 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5080 and more efficient S-record downloading.
5082 * Memory use reductions and statistics collection
5084 GDB now uses less memory and reports statistics about memory usage.
5085 Try the `maint print statistics' command, for example.
5087 *** Changes in GDB-4.15:
5089 * Psymtabs for XCOFF
5091 The symbol reader for AIX GDB now uses partial symbol tables. This
5092 can greatly improve startup time, especially for large executables.
5094 * Remote targets use caching
5096 Remote targets now use a data cache to speed up communication with the
5097 remote side. The data cache could lead to incorrect results because
5098 it doesn't know about volatile variables, thus making it impossible to
5099 debug targets which use memory mapped I/O devices. `set remotecache
5100 off' turns the the data cache off.
5102 * Remote targets may have threads
5104 The standard remote protocol now includes support for multiple threads
5105 in the target system, using new protocol commands 'H' and 'T'. See
5106 gdb/remote.c for details.
5110 If GDB is configured with `--enable-netrom', then it will include
5111 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5112 acts as though it is a bank of ROM on the target board, but you can
5113 write into it over the network. GDB's support consists only of
5114 support for fast loading into the emulated ROM; to debug, you must use
5115 another protocol, such as standard remote protocol. The usual
5116 sequence is something like
5118 target nrom <netrom-hostname>
5120 target remote <netrom-hostname>:1235
5124 GDB now includes support for the Apple Macintosh, as a host only. It
5125 may be run as either an MPW tool or as a standalone application, and
5126 it can debug through the serial port. All the usual GDB commands are
5127 available, but to the target command, you must supply "serial" as the
5128 device type instead of "/dev/ttyXX". See mpw-README in the main
5129 directory for more information on how to build. The MPW configuration
5130 scripts */mpw-config.in support only a few targets, and only the
5131 mips-idt-ecoff target has been tested.
5135 GDB configuration now uses autoconf. This is not user-visible,
5136 but does simplify configuration and building.
5140 GDB now supports hpux10.
5142 *** Changes in GDB-4.14:
5144 * New native configurations
5146 x86 FreeBSD i[345]86-*-freebsd
5147 x86 NetBSD i[345]86-*-netbsd
5148 NS32k NetBSD ns32k-*-netbsd
5149 Sparc NetBSD sparc-*-netbsd
5153 A29K VxWorks a29k-*-vxworks
5154 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5155 CPU32 EST-300 emulator m68*-*-est*
5156 PowerPC ELF powerpc-*-elf
5159 * Alpha OSF/1 support for procfs
5161 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5162 possible to attach to running processes. As the mounting of the /proc
5163 filesystem is optional on the Alpha, GDB automatically determines
5164 the availability of /proc during startup. This can lead to problems
5165 if /proc is unmounted after GDB has been started.
5167 * Arguments to user-defined commands
5169 User commands may accept up to 10 arguments separated by whitespace.
5170 Arguments are accessed within the user command via $arg0..$arg9. A
5173 print $arg0 + $arg1 + $arg2
5175 To execute the command use:
5178 Defines the command "adder" which prints the sum of its three arguments.
5179 Note the arguments are text substitutions, so they may reference variables,
5180 use complex expressions, or even perform inferior function calls.
5182 * New `if' and `while' commands
5184 This makes it possible to write more sophisticated user-defined
5185 commands. Both commands take a single argument, which is the
5186 expression to evaluate, and must be followed by the commands to
5187 execute, one per line, if the expression is nonzero, the list being
5188 terminated by the word `end'. The `if' command list may include an
5189 `else' word, which causes the following commands to be executed only
5190 if the expression is zero.
5192 * Fortran source language mode
5194 GDB now includes partial support for Fortran 77. It will recognize
5195 Fortran programs and can evaluate a subset of Fortran expressions, but
5196 variables and functions may not be handled correctly. GDB will work
5197 with G77, but does not yet know much about symbols emitted by other
5200 * Better HPUX support
5202 Most debugging facilities now work on dynamic executables for HPPAs
5203 running hpux9 or later. You can attach to running dynamically linked
5204 processes, but by default the dynamic libraries will be read-only, so
5205 for instance you won't be able to put breakpoints in them. To change
5206 that behavior do the following before running the program:
5212 This will cause the libraries to be mapped private and read-write.
5213 To revert to the normal behavior, do this:
5219 You cannot set breakpoints or examine data in the library until after
5220 the library is loaded if the function/data symbols do not have
5223 GDB can now also read debug symbols produced by the HP C compiler on
5224 HPPAs (sorry, no C++, Fortran or 68k support).
5226 * Target byte order now dynamically selectable
5228 You can choose which byte order to use with a target system, via the
5229 commands "set endian big" and "set endian little", and you can see the
5230 current setting by using "show endian". You can also give the command
5231 "set endian auto", in which case GDB will use the byte order
5232 associated with the executable. Currently, only embedded MIPS
5233 configurations support dynamic selection of target byte order.
5235 * New DOS host serial code
5237 This version uses DPMI interrupts to handle buffered I/O, so you
5238 no longer need to run asynctsr when debugging boards connected to
5241 *** Changes in GDB-4.13:
5243 * New "complete" command
5245 This lists all the possible completions for the rest of the line, if it
5246 were to be given as a command itself. This is intended for use by emacs.
5248 * Trailing space optional in prompt
5250 "set prompt" no longer adds a space for you after the prompt you set. This
5251 allows you to set a prompt which ends in a space or one that does not.
5253 * Breakpoint hit counts
5255 "info break" now displays a count of the number of times the breakpoint
5256 has been hit. This is especially useful in conjunction with "ignore"; you
5257 can ignore a large number of breakpoint hits, look at the breakpoint info
5258 to see how many times the breakpoint was hit, then run again, ignoring one
5259 less than that number, and this will get you quickly to the last hit of
5262 * Ability to stop printing at NULL character
5264 "set print null-stop" will cause GDB to stop printing the characters of
5265 an array when the first NULL is encountered. This is useful when large
5266 arrays actually contain only short strings.
5268 * Shared library breakpoints
5270 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5271 breakpoints in shared libraries before the executable is run.
5273 * Hardware watchpoints
5275 There is a new hardware breakpoint for the watch command for sparclite
5276 targets. See gdb/sparclite/hw_breakpoint.note.
5278 Hardware watchpoints are also now supported under GNU/Linux.
5282 Annotations have been added. These are for use with graphical interfaces,
5283 and are still experimental. Currently only gdba.el uses these.
5285 * Improved Irix 5 support
5287 GDB now works properly with Irix 5.2.
5289 * Improved HPPA support
5291 GDB now works properly with the latest GCC and GAS.
5293 * New native configurations
5295 Sequent PTX4 i[34]86-sequent-ptx4
5296 HPPA running OSF/1 hppa*-*-osf*
5297 Atari TT running SVR4 m68*-*-sysv4*
5298 RS/6000 LynxOS rs6000-*-lynxos*
5302 OS/9000 i[34]86-*-os9k
5303 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5306 * Hitachi SH7000 and E7000-PC ICE support
5308 There is now support for communicating with the Hitachi E7000-PC ICE.
5309 This is available automatically when GDB is configured for the SH.
5313 As usual, a variety of small fixes and improvements, both generic
5314 and configuration-specific. See the ChangeLog for more detail.
5316 *** Changes in GDB-4.12:
5318 * Irix 5 is now supported
5322 GDB-4.12 on the HPPA has a number of changes which make it unable
5323 to debug the output from the currently released versions of GCC and
5324 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5325 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5326 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5329 *** Changes in GDB-4.11:
5331 * User visible changes:
5335 The "set remotedebug" option is now consistent between the mips remote
5336 target, remote targets using the gdb-specific protocol, UDI (AMD's
5337 debug protocol for the 29k) and the 88k bug monitor. It is now an
5338 integer specifying a debug level (normally 0 or 1, but 2 means more
5339 debugging info for the mips target).
5341 * DEC Alpha native support
5343 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5344 debug info, but GDB works fairly well with the DEC compiler and should
5345 work with a future GCC release. See the README file for a few
5346 Alpha-specific notes.
5348 * Preliminary thread implementation
5350 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5352 * LynxOS native and target support for 386
5354 This release has been hosted on LynxOS 2.2, and also can be configured
5355 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5358 * Improvements in C++ mangling/demangling.
5360 This release has much better g++ debugging, specifically in name
5361 mangling/demangling, virtual function calls, print virtual table,
5362 call methods, ...etc.
5364 *** Changes in GDB-4.10:
5366 * User visible changes:
5368 Remote debugging using the GDB-specific (`target remote') protocol now
5369 supports the `load' command. This is only useful if you have some
5370 other way of getting the stub to the target system, and you can put it
5371 somewhere in memory where it won't get clobbered by the download.
5373 Filename completion now works.
5375 When run under emacs mode, the "info line" command now causes the
5376 arrow to point to the line specified. Also, "info line" prints
5377 addresses in symbolic form (as well as hex).
5379 All vxworks based targets now support a user settable option, called
5380 vxworks-timeout. This option represents the number of seconds gdb
5381 should wait for responses to rpc's. You might want to use this if
5382 your vxworks target is, perhaps, a slow software simulator or happens
5383 to be on the far side of a thin network line.
5387 This release contains support for using a DEC alpha as a GDB host for
5388 cross debugging. Native alpha debugging is not supported yet.
5391 *** Changes in GDB-4.9:
5395 This is the first GDB release which is accompanied by a matching testsuite.
5396 The testsuite requires installation of dejagnu, which should be available
5397 via ftp from most sites that carry GNU software.
5401 'Cfront' style demangling has had its name changed to 'ARM' style, to
5402 emphasize that it was written from the specifications in the C++ Annotated
5403 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5404 disclaimers, it still generated too much confusion with users attempting to
5405 use gdb with AT&T cfront.
5409 GDB now uses a standard remote interface to a simulator library.
5410 So far, the library contains simulators for the Zilog Z8001/2, the
5411 Hitachi H8/300, H8/500 and Super-H.
5413 * New targets supported
5415 H8/300 simulator h8300-hitachi-hms or h8300hms
5416 H8/500 simulator h8500-hitachi-hms or h8500hms
5417 SH simulator sh-hitachi-hms or sh
5418 Z8000 simulator z8k-zilog-none or z8ksim
5419 IDT MIPS board over serial line mips-idt-ecoff
5421 Cross-debugging to GO32 targets is supported. It requires a custom
5422 version of the i386-stub.c module which is integrated with the
5423 GO32 memory extender.
5425 * New remote protocols
5427 MIPS remote debugging protocol.
5429 * New source languages supported
5431 This version includes preliminary support for Chill, a Pascal like language
5432 used by telecommunications companies. Chill support is also being integrated
5433 into the GNU compiler, but we don't know when it will be publically available.
5436 *** Changes in GDB-4.8:
5438 * HP Precision Architecture supported
5440 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5441 version of this support was available as a set of patches from the
5442 University of Utah. GDB does not support debugging of programs
5443 compiled with the HP compiler, because HP will not document their file
5444 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5445 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5447 Many problems in the preliminary version have been fixed.
5449 * Faster and better demangling
5451 We have improved template demangling and fixed numerous bugs in the GNU style
5452 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5453 character types (wchar_t) are now supported. Demangling of each symbol is now
5454 only done once, and is cached when the symbol table for a file is read in.
5455 This results in a small increase in memory usage for C programs, a moderate
5456 increase in memory usage for C++ programs, and a fantastic speedup in
5459 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5460 from the specifications in the Annotated Reference Manual, which AT&T's
5461 compiler does not actually implement.
5463 * G++ multiple inheritance compiler problem
5465 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5466 inheritance lattices was reworked to properly discover ambiguities. We
5467 recently found an example which causes this new algorithm to fail in a
5468 very subtle way, producing bad debug information for those classes.
5469 The file 'gcc.patch' (in this directory) can be applied to gcc to
5470 circumvent the problem. A future GCC release will contain a complete
5473 The previous G++ debug info problem (mentioned below for the gdb-4.7
5474 release) is fixed in gcc version 2.3.2.
5476 * Improved configure script
5478 The `configure' script will now attempt to guess your system type if
5479 you don't supply a host system type. The old scheme of supplying a
5480 host system triplet is preferable over using this. All the magic is
5481 done in the new `config.guess' script. Examine it for details.
5483 We have also brought our configure script much more in line with the FSF's
5484 version. It now supports the --with-xxx options. In particular,
5485 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5486 The resulting GDB will not be able to read arbitrary object file formats --
5487 only the format ``expected'' to be used on the configured target system.
5488 We hope to make this the default in a future release.
5490 * Documentation improvements
5492 There's new internal documentation on how to modify GDB, and how to
5493 produce clean changes to the code. We implore people to read it
5494 before submitting changes.
5496 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5497 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5498 `info' files are also provided. To build `info' files from scratch,
5499 you will need the latest `makeinfo' release, which will be available in
5500 a future texinfo-X.Y release.
5502 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5503 We're not sure exactly which versions have this problem, but it has
5504 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5505 or better. If that isn't possible, there is a patch in
5506 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5507 around this problem.
5511 GDB now supports array constants that can be used in expressions typed in by
5512 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5513 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5516 The new directory `gdb/sparclite' contains a program that demonstrates
5517 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5519 * New native hosts supported
5521 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5522 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5524 * New targets supported
5526 AMD 29k family via UDI a29k-amd-udi or udi29k
5528 * New file formats supported
5530 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5531 HPUX core files, and SCO 3.2v2 core files.
5535 Attaching to processes now works again; thanks for the many bug reports.
5537 We have also stomped on a bunch of core dumps caused by
5538 printf_filtered("%s") problems.
5540 We eliminated a copyright problem on the rpc and ptrace header files
5541 for VxWorks, which was discovered at the last minute during the 4.7
5542 release. You should now be able to build a VxWorks GDB.
5544 You can now interrupt gdb while an attached process is running. This
5545 will cause the attached process to stop, and give control back to GDB.
5547 We fixed problems caused by using too many file descriptors
5548 for reading symbols from object files and libraries. This was
5549 especially a problem for programs that used many (~100) shared
5552 The `step' command now only enters a subroutine if there is line number
5553 information for the subroutine. Otherwise it acts like the `next'
5554 command. Previously, `step' would enter subroutines if there was
5555 any debugging information about the routine. This avoids problems
5556 when using `cc -g1' on MIPS machines.
5558 * Internal improvements
5560 GDB's internal interfaces have been improved to make it easier to support
5561 debugging of multiple languages in the future.
5563 GDB now uses a common structure for symbol information internally.
5564 Minimal symbols (derived from linkage symbols in object files), partial
5565 symbols (from a quick scan of debug information), and full symbols
5566 contain a common subset of information, making it easier to write
5567 shared code that handles any of them.
5569 * New command line options
5571 We now accept --silent as an alias for --quiet.
5575 The memory-mapped-malloc library is now licensed under the GNU Library
5576 General Public License.
5578 *** Changes in GDB-4.7:
5580 * Host/native/target split
5582 GDB has had some major internal surgery to untangle the support for
5583 hosts and remote targets. Now, when you configure GDB for a remote
5584 target, it will no longer load in all of the support for debugging
5585 local programs on the host. When fully completed and tested, this will
5586 ensure that arbitrary host/target combinations are possible.
5588 The primary conceptual shift is to separate the non-portable code in
5589 GDB into three categories. Host specific code is required any time GDB
5590 is compiled on that host, regardless of the target. Target specific
5591 code relates to the peculiarities of the target, but can be compiled on
5592 any host. Native specific code is everything else: it can only be
5593 built when the host and target are the same system. Child process
5594 handling and core file support are two common `native' examples.
5596 GDB's use of /proc for controlling Unix child processes is now cleaner.
5597 It has been split out into a single module under the `target_ops' vector,
5598 plus two native-dependent functions for each system that uses /proc.
5600 * New hosts supported
5602 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5603 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5604 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5606 * New targets supported
5608 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5609 68030 and CPU32 m68030-*-*, m68332-*-*
5611 * New native hosts supported
5613 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5614 (386bsd is not well tested yet)
5615 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5617 * New file formats supported
5619 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5620 supports reading of `a.out.adobe' object files, which are an a.out
5621 format extended with minimal information about multiple sections.
5625 `show copying' is the same as the old `info copying'.
5626 `show warranty' is the same as `info warrantee'.
5627 These were renamed for consistency. The old commands continue to work.
5629 `info handle' is a new alias for `info signals'.
5631 You can now define pre-command hooks, which attach arbitrary command
5632 scripts to any command. The commands in the hook will be executed
5633 prior to the user's command. You can also create a hook which will be
5634 executed whenever the program stops. See gdb.texinfo.
5638 We now deal with Cfront style name mangling, and can even extract type
5639 info from mangled symbols. GDB can automatically figure out which
5640 symbol mangling style your C++ compiler uses.
5642 Calling of methods and virtual functions has been improved as well.
5646 The crash that occured when debugging Sun Ansi-C compiled binaries is
5647 fixed. This was due to mishandling of the extra N_SO stabs output
5650 We also finally got Ultrix 4.2 running in house, and fixed core file
5651 support, with help from a dozen people on the net.
5653 John M. Farrell discovered that the reason that single-stepping was so
5654 slow on all of the Mips based platforms (primarily SGI and DEC) was
5655 that we were trying to demangle and lookup a symbol used for internal
5656 purposes on every instruction that was being stepped through. Changing
5657 the name of that symbol so that it couldn't be mistaken for a C++
5658 mangled symbol sped things up a great deal.
5660 Rich Pixley sped up symbol lookups in general by getting much smarter
5661 about when C++ symbol mangling is necessary. This should make symbol
5662 completion (TAB on the command line) much faster. It's not as fast as
5663 we'd like, but it's significantly faster than gdb-4.6.
5667 A new user controllable variable 'call_scratch_address' can
5668 specify the location of a scratch area to be used when GDB
5669 calls a function in the target. This is necessary because the
5670 usual method of putting the scratch area on the stack does not work
5671 in systems that have separate instruction and data spaces.
5673 We integrated changes to support the 29k UDI (Universal Debugger
5674 Interface), but discovered at the last minute that we didn't have all
5675 of the appropriate copyright paperwork. We are working with AMD to
5676 resolve this, and hope to have it available soon.
5680 We have sped up the remote serial line protocol, especially for targets
5681 with lots of registers. It now supports a new `expedited status' ('T')
5682 message which can be used in place of the existing 'S' status message.
5683 This allows the remote stub to send only the registers that GDB
5684 needs to make a quick decision about single-stepping or conditional
5685 breakpoints, eliminating the need to fetch the entire register set for
5686 each instruction being stepped through.
5688 The GDB remote serial protocol now implements a write-through cache for
5689 registers, only re-reading the registers if the target has run.
5691 There is also a new remote serial stub for SPARC processors. You can
5692 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5693 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5694 processor with a serial port.
5698 Configure.in files have become much easier to read and modify. A new
5699 `table driven' format makes it more obvious what configurations are
5700 supported, and what files each one uses.
5704 There is a new opcodes library which will eventually contain all of the
5705 disassembly routines and opcode tables. At present, it only contains
5706 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5707 disassembler (binutils/objdump) to share these routines.
5709 The libiberty library is now copylefted under the GNU Library General
5710 Public License. This allows more liberal use, and was done so libg++
5711 can use it. This makes no difference to GDB, since the Library License
5712 grants all the rights from the General Public License.
5716 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5717 reference to the stabs symbol info used by the debugger. It is (as far
5718 as we know) the only published document on this fascinating topic. We
5719 encourage you to read it, compare it to the stabs information on your
5720 system, and send improvements on the document in general (to
5723 And, of course, many bugs have been fixed.
5726 *** Changes in GDB-4.6:
5728 * Better support for C++ function names
5730 GDB now accepts as input the "demangled form" of C++ overloaded function
5731 names and member function names, and can do command completion on such names
5732 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5733 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5734 Make use of command completion, it is your friend.
5736 GDB also now accepts a variety of C++ mangled symbol formats. They are
5737 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5738 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5739 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5740 for the list of formats.
5742 * G++ symbol mangling problem
5744 Recent versions of gcc have a bug in how they emit debugging information for
5745 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5746 directory) can be applied to gcc to fix the problem. Alternatively, if you
5747 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5748 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5749 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5752 * New 'maintenance' command
5754 All of the commands related to hacking GDB internals have been moved out of
5755 the main command set, and now live behind the 'maintenance' command. This
5756 can also be abbreviated as 'mt'. The following changes were made:
5758 dump-me -> maintenance dump-me
5759 info all-breakpoints -> maintenance info breakpoints
5760 printmsyms -> maintenance print msyms
5761 printobjfiles -> maintenance print objfiles
5762 printpsyms -> maintenance print psymbols
5763 printsyms -> maintenance print symbols
5765 The following commands are new:
5767 maintenance demangle Call internal GDB demangler routine to
5768 demangle a C++ link name and prints the result.
5769 maintenance print type Print a type chain for a given symbol
5771 * Change to .gdbinit file processing
5773 We now read the $HOME/.gdbinit file before processing the argv arguments
5774 (e.g. reading symbol files or core files). This allows global parameters to
5775 be set, which will apply during the symbol reading. The ./.gdbinit is still
5776 read after argv processing.
5778 * New hosts supported
5780 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5782 GNU/Linux support i386-unknown-linux or linux
5784 We are also including code to support the HP/PA running BSD and HPUX. This
5785 is almost guaranteed not to work, as we didn't have time to test or build it
5786 for this release. We are including it so that the more adventurous (or
5787 masochistic) of you can play with it. We also had major problems with the
5788 fact that the compiler that we got from HP doesn't support the -g option.
5791 * New targets supported
5793 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5795 * More smarts about finding #include files
5797 GDB now remembers the compilation directory for all include files, and for
5798 all files from which C is generated (like yacc and lex sources). This
5799 greatly improves GDB's ability to find yacc/lex sources, and include files,
5800 especially if you are debugging your program from a directory different from
5801 the one that contains your sources.
5803 We also fixed a bug which caused difficulty with listing and setting
5804 breakpoints in include files which contain C code. (In the past, you had to
5805 try twice in order to list an include file that you hadn't looked at before.)
5807 * Interesting infernals change
5809 GDB now deals with arbitrary numbers of sections, where the symbols for each
5810 section must be relocated relative to that section's landing place in the
5811 target's address space. This work was needed to support ELF with embedded
5812 stabs used by Solaris-2.0.
5814 * Bug fixes (of course!)
5816 There have been loads of fixes for the following things:
5817 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5818 i960, stabs, DOS(GO32), procfs, etc...
5820 See the ChangeLog for details.
5822 *** Changes in GDB-4.5:
5824 * New machines supported (host and target)
5826 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5828 SGI Irix-4.x mips-sgi-irix4 or iris4
5830 * New malloc package
5832 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5833 Mmalloc is capable of handling mutiple heaps of memory. It is also
5834 capable of saving a heap to a file, and then mapping it back in later.
5835 This can be used to greatly speedup the startup of GDB by using a
5836 pre-parsed symbol table which lives in a mmalloc managed heap. For
5837 more details, please read mmalloc/mmalloc.texi.
5841 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5842 'help info proc' for details.
5844 * MIPS ecoff symbol table format
5846 The code that reads MIPS symbol table format is now supported on all hosts.
5847 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5850 * File name changes for MS-DOS
5852 Many files in the config directories have been renamed to make it easier to
5853 support GDB on MS-DOSe systems (which have very restrictive file name
5854 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5855 environment) is close to working but has some remaining problems. Note
5856 that debugging of DOS programs is not supported, due to limitations
5857 in the ``operating system'', but it can be used to host cross-debugging.
5859 * Cross byte order fixes
5861 Many fixes have been made to support cross debugging of Sparc and MIPS
5862 targets from hosts whose byte order differs.
5864 * New -mapped and -readnow options
5866 If memory-mapped files are available on your system through the 'mmap'
5867 system call, you can use the -mapped option on the `file' or
5868 `symbol-file' commands to cause GDB to write the symbols from your
5869 program into a reusable file. If the program you are debugging is
5870 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5871 Future GDB debugging sessions will notice the presence of this file,
5872 and will quickly map in symbol information from it, rather than reading
5873 the symbol table from the executable program. Using the '-mapped'
5874 option in a GDB `file' or `symbol-file' command has the same effect as
5875 starting GDB with the '-mapped' command-line option.
5877 You can cause GDB to read the entire symbol table immediately by using
5878 the '-readnow' option with any of the commands that load symbol table
5879 information (or on the GDB command line). This makes the command
5880 slower, but makes future operations faster.
5882 The -mapped and -readnow options are typically combined in order to
5883 build a `fred.syms' file that contains complete symbol information.
5884 A simple GDB invocation to do nothing but build a `.syms' file for future
5887 gdb -batch -nx -mapped -readnow programname
5889 The `.syms' file is specific to the host machine on which GDB is run.
5890 It holds an exact image of GDB's internal symbol table. It cannot be
5891 shared across multiple host platforms.
5893 * longjmp() handling
5895 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5896 siglongjmp() without losing control. This feature has not yet been ported to
5897 all systems. It currently works on many 386 platforms, all MIPS-based
5898 platforms (SGI, DECstation, etc), and Sun3/4.
5902 Preliminary work has been put in to support the new Solaris OS from Sun. At
5903 this time, it can control and debug processes, but it is not capable of
5908 As always, many many bug fixes. The major areas were with g++, and mipsread.
5909 People using the MIPS-based platforms should experience fewer mysterious
5910 crashes and trashed symbol tables.
5912 *** Changes in GDB-4.4:
5914 * New machines supported (host and target)
5916 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5918 BSD Reno on Vax vax-dec-bsd
5919 Ultrix on Vax vax-dec-ultrix
5921 * New machines supported (target)
5923 AMD 29000 embedded, using EBMON a29k-none-none
5927 GDB continues to improve its handling of C++. `References' work better.
5928 The demangler has also been improved, and now deals with symbols mangled as
5929 per the Annotated C++ Reference Guide.
5931 GDB also now handles `stabs' symbol information embedded in MIPS
5932 `ecoff' symbol tables. Since the ecoff format was not easily
5933 extensible to handle new languages such as C++, this appeared to be a
5934 good way to put C++ debugging info into MIPS binaries. This option
5935 will be supported in the GNU C compiler, version 2, when it is
5938 * New features for SVR4
5940 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5941 shared libraries. Debugging dynamically linked programs should present
5942 only minor differences from debugging statically linked programs.
5944 The `info proc' command will print out information about any process
5945 on an SVR4 system (including the one you are debugging). At the moment,
5946 it prints the address mappings of the process.
5948 If you bring up GDB on another SVR4 system, please send mail to
5951 * Better dynamic linking support in SunOS
5953 Reading symbols from shared libraries which contain debugging symbols
5954 now works properly. However, there remain issues such as automatic
5955 skipping of `transfer vector' code during function calls, which
5956 make it harder to debug code in a shared library, than to debug the
5957 same code linked statically.
5961 GDB is now using the latest `getopt' routines from the FSF. This
5962 version accepts the -- prefix for options with long names. GDB will
5963 continue to accept the old forms (-option and +option) as well.
5964 Various single letter abbreviations for options have been explicity
5965 added to the option table so that they won't get overshadowed in the
5966 future by other options that begin with the same letter.
5970 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5971 Many assorted bugs have been handled. Many more remain to be handled.
5972 See the various ChangeLog files (primarily in gdb and bfd) for details.
5975 *** Changes in GDB-4.3:
5977 * New machines supported (host and target)
5979 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5980 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5981 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5983 * Almost SCO Unix support
5985 We had hoped to support:
5986 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5987 (except for core file support), but we discovered very late in the release
5988 that it has problems with process groups that render gdb unusable. Sorry
5989 about that. I encourage people to fix it and post the fixes.
5991 * Preliminary ELF and DWARF support
5993 GDB can read ELF object files on System V Release 4, and can handle
5994 debugging records for C, in DWARF format, in ELF files. This support
5995 is preliminary. If you bring up GDB on another SVR4 system, please
6001 GDB now uses the latest `readline' library. One user-visible change
6002 is that two tabs will list possible command completions, which previously
6003 required typing M-? (meta-question mark, or ESC ?).
6007 The `stepi' bug that many of you noticed has been squashed.
6008 Many bugs in C++ have been handled. Many more remain to be handled.
6009 See the various ChangeLog files (primarily in gdb and bfd) for details.
6011 * State of the MIPS world (in case you wondered):
6013 GDB can understand the symbol tables emitted by the compilers
6014 supplied by most vendors of MIPS-based machines, including DEC. These
6015 symbol tables are in a format that essentially nobody else uses.
6017 Some versions of gcc come with an assembler post-processor called
6018 mips-tfile. This program is required if you want to do source-level
6019 debugging of gcc-compiled programs. I believe FSF does not ship
6020 mips-tfile with gcc version 1, but it will eventually come with gcc
6023 Debugging of g++ output remains a problem. g++ version 1.xx does not
6024 really support it at all. (If you're lucky, you should be able to get
6025 line numbers and stack traces to work, but no parameters or local
6026 variables.) With some work it should be possible to improve the
6029 When gcc version 2 is released, you will have somewhat better luck.
6030 However, even then you will get confusing results for inheritance and
6033 We will eventually provide full debugging of g++ output on
6034 DECstations. This will probably involve some kind of stabs-in-ecoff
6035 encapulation, but the details have not been worked out yet.
6038 *** Changes in GDB-4.2:
6040 * Improved configuration
6042 Only one copy of `configure' exists now, and it is not self-modifying.
6043 Porting BFD is simpler.
6047 The `step' and `next' commands now only stop at the first instruction
6048 of a source line. This prevents the multiple stops that used to occur
6049 in switch statements, for-loops, etc. `Step' continues to stop if a
6050 function that has debugging information is called within the line.
6054 Lots of small bugs fixed. More remain.
6056 * New host supported (not target)
6058 Intel 386 PC clone running Mach i386-none-mach
6061 *** Changes in GDB-4.1:
6063 * Multiple source language support
6065 GDB now has internal scaffolding to handle several source languages.
6066 It determines the type of each source file from its filename extension,
6067 and will switch expression parsing and number formatting to match the
6068 language of the function in the currently selected stack frame.
6069 You can also specifically set the language to be used, with
6070 `set language c' or `set language modula-2'.
6074 GDB now has preliminary support for the GNU Modula-2 compiler,
6075 currently under development at the State University of New York at
6076 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6077 continue through the fall of 1991 and into 1992.
6079 Other Modula-2 compilers are currently not supported, and attempting to
6080 debug programs compiled with them will likely result in an error as the
6081 symbol table is read. Feel free to work on it, though!
6083 There are hooks in GDB for strict type checking and range checking,
6084 in the `Modula-2 philosophy', but they do not currently work.
6088 GDB can now write to executable and core files (e.g. patch
6089 a variable's value). You must turn this switch on, specify
6090 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6091 by assigning a new value to a variable. Modifications take
6094 * Automatic SunOS shared library reading
6096 When you run your program, GDB automatically determines where its
6097 shared libraries (if any) have been loaded, and reads their symbols.
6098 The `share' command is no longer needed. This also works when
6099 examining core files.
6103 You can specify the number of lines that the `list' command shows.
6106 * New machines supported (host and target)
6108 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6109 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6110 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6112 * New hosts supported (not targets)
6114 IBM RT/PC: romp-ibm-aix or rtpc
6116 * New targets supported (not hosts)
6118 AMD 29000 embedded with COFF a29k-none-coff
6119 AMD 29000 embedded with a.out a29k-none-aout
6120 Ultracomputer remote kernel debug a29k-nyu-kern
6122 * New remote interfaces
6128 *** Changes in GDB-4.0:
6132 Wide output is wrapped at good places to make the output more readable.
6134 Gdb now supports cross-debugging from a host machine of one type to a
6135 target machine of another type. Communication with the target system
6136 is over serial lines. The ``target'' command handles connecting to the
6137 remote system; the ``load'' command will download a program into the
6138 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6139 also supports debugging of realtime processes running under VxWorks,
6140 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6141 stub on the target system.
6143 New CPUs supported include the AMD 29000 and Intel 960.
6145 GDB now reads object files and symbol tables via a ``binary file''
6146 library, which allows a single copy of GDB to debug programs of multiple
6147 object file types such as a.out and coff.
6149 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6150 refcard.dvi and refcard.ps are available to format it).
6153 * Control-Variable user interface simplified
6155 All variables that control the operation of the debugger can be set
6156 by the ``set'' command, and displayed by the ``show'' command.
6158 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6159 ``Show prompt'' produces the response:
6160 Gdb's prompt is new-gdb=>.
6162 What follows are the NEW set commands. The command ``help set'' will
6163 print a complete list of old and new set commands. ``help set FOO''
6164 will give a longer description of the variable FOO. ``show'' will show
6165 all of the variable descriptions and their current settings.
6167 confirm on/off: Enables warning questions for operations that are
6168 hard to recover from, e.g. rerunning the program while
6169 it is already running. Default is ON.
6171 editing on/off: Enables EMACS style command line editing
6172 of input. Previous lines can be recalled with
6173 control-P, the current line can be edited with control-B,
6174 you can search for commands with control-R, etc.
6177 history filename NAME: NAME is where the gdb command history
6178 will be stored. The default is .gdb_history,
6179 or the value of the environment variable
6182 history size N: The size, in commands, of the command history. The
6183 default is 256, or the value of the environment variable
6186 history save on/off: If this value is set to ON, the history file will
6187 be saved after exiting gdb. If set to OFF, the
6188 file will not be saved. The default is OFF.
6190 history expansion on/off: If this value is set to ON, then csh-like
6191 history expansion will be performed on
6192 command line input. The default is OFF.
6194 radix N: Sets the default radix for input and output. It can be set
6195 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6196 in the current radix, so "set radix 10" is always a no-op.
6198 height N: This integer value is the number of lines on a page. Default
6199 is 24, the current `stty rows'' setting, or the ``li#''
6200 setting from the termcap entry matching the environment
6203 width N: This integer value is the number of characters on a line.
6204 Default is 80, the current `stty cols'' setting, or the ``co#''
6205 setting from the termcap entry matching the environment
6208 Note: ``set screensize'' is obsolete. Use ``set height'' and
6209 ``set width'' instead.
6211 print address on/off: Print memory addresses in various command displays,
6212 such as stack traces and structure values. Gdb looks
6213 more ``symbolic'' if you turn this off; it looks more
6214 ``machine level'' with it on. Default is ON.
6216 print array on/off: Prettyprint arrays. New convenient format! Default
6219 print demangle on/off: Print C++ symbols in "source" form if on,
6222 print asm-demangle on/off: Same, for assembler level printouts
6225 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6228 * Support for Epoch Environment.
6230 The epoch environment is a version of Emacs v18 with windowing. One
6231 new command, ``inspect'', is identical to ``print'', except that if you
6232 are running in the epoch environment, the value is printed in its own
6236 * Support for Shared Libraries
6238 GDB can now debug programs and core files that use SunOS shared libraries.
6239 Symbols from a shared library cannot be referenced
6240 before the shared library has been linked with the program (this
6241 happens after you type ``run'' and before the function main() is entered).
6242 At any time after this linking (including when examining core files
6243 from dynamically linked programs), gdb reads the symbols from each
6244 shared library when you type the ``sharedlibrary'' command.
6245 It can be abbreviated ``share''.
6247 sharedlibrary REGEXP: Load shared object library symbols for files
6248 matching a unix regular expression. No argument
6249 indicates to load symbols for all shared libraries.
6251 info sharedlibrary: Status of loaded shared libraries.
6256 A watchpoint stops execution of a program whenever the value of an
6257 expression changes. Checking for this slows down execution
6258 tremendously whenever you are in the scope of the expression, but is
6259 quite useful for catching tough ``bit-spreader'' or pointer misuse
6260 problems. Some machines such as the 386 have hardware for doing this
6261 more quickly, and future versions of gdb will use this hardware.
6263 watch EXP: Set a watchpoint (breakpoint) for an expression.
6265 info watchpoints: Information about your watchpoints.
6267 delete N: Deletes watchpoint number N (same as breakpoints).
6268 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6269 enable N: Re-enables watchpoint number N (same as breakpoints).
6272 * C++ multiple inheritance
6274 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6277 * C++ exception handling
6279 Gdb now supports limited C++ exception handling. Besides the existing
6280 ability to breakpoint on an exception handler, gdb can breakpoint on
6281 the raising of an exception (before the stack is peeled back to the
6284 catch FOO: If there is a FOO exception handler in the dynamic scope,
6285 set a breakpoint to catch exceptions which may be raised there.
6286 Multiple exceptions (``catch foo bar baz'') may be caught.
6288 info catch: Lists all exceptions which may be caught in the
6289 current stack frame.
6292 * Minor command changes
6294 The command ``call func (arg, arg, ...)'' now acts like the print
6295 command, except it does not print or save a value if the function's result
6296 is void. This is similar to dbx usage.
6298 The ``up'' and ``down'' commands now always print the frame they end up
6299 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6300 frames without printing.
6302 * New directory command
6304 'dir' now adds directories to the FRONT of the source search path.
6305 The path starts off empty. Source files that contain debug information
6306 about the directory in which they were compiled can be found even
6307 with an empty path; Sun CC and GCC include this information. If GDB can't
6308 find your source file in the current directory, type "dir .".
6310 * Configuring GDB for compilation
6312 For normal use, type ``./configure host''. See README or gdb.texinfo
6315 GDB now handles cross debugging. If you are remotely debugging between
6316 two different machines, type ``./configure host -target=targ''.
6317 Host is the machine where GDB will run; targ is the machine
6318 where the program that you are debugging will run.