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 * The "disassemble" command accepts a new modifier: /s.
52 It prints mixed source+disassembly like /m with two differences:
53 - disassembled instructions are now printed in program order, and
54 - and source for all relevant files is now printed.
55 The "/m" option is now considered deprecated: its "source-centric"
56 output hasn't proved useful in practice.
58 * The "record instruction-history" command accepts a new modifier: /s.
59 It behaves exactly like /m and prints mixed source+disassembly.
61 * The "set scheduler-locking" command supports a new mode "replay".
62 It behaves like "off" in record mode and like "on" in replay mode.
64 * Support for various ROM monitors has been removed:
66 target dbug dBUG ROM monitor for Motorola ColdFire
67 target picobug Motorola picobug monitor
68 target dink32 DINK32 ROM monitor for PowerPC
69 target m32r Renesas M32R/D ROM monitor
70 target mon2000 mon2000 ROM monitor
71 target ppcbug PPCBUG ROM monitor for PowerPC
73 * Support for reading/writing memory and extracting values on architectures
74 whose memory is addressable in units of any integral multiple of 8 bits.
79 Indicates that an exec system call was executed.
81 exec-events feature in qSupported
82 The qSupported packet allows GDB to request support for exec
83 events using the new 'gdbfeature' exec-event, and the qSupported
84 response can contain the corresponding 'stubfeature'. Set and
85 show commands can be used to display whether these features are enabled.
88 Equivalent to interrupting with the ^C character, but works in
91 * Extended-remote exec events
93 ** GDB now has support for exec events on extended-remote Linux targets.
94 For such targets with Linux kernels 2.5.46 and later, this enables
95 follow-exec-mode and exec catchpoints.
97 set remote exec-event-feature-packet
98 show remote exec-event-feature-packet
99 Set/show the use of the remote exec event feature.
101 * Thread names in remote protocol
103 The reply to qXfer:threads:read may now include a name attribute for each
106 *** Changes in GDB 7.10
108 * Support for process record-replay and reverse debugging on aarch64*-linux*
109 targets has been added. GDB now supports recording of A64 instruction set
110 including advance SIMD instructions.
112 * Support for Sun's version of the "stabs" debug file format has been removed.
114 * GDB now honors the content of the file /proc/PID/coredump_filter
115 (PID is the process ID) on GNU/Linux systems. This file can be used
116 to specify the types of memory mappings that will be included in a
117 corefile. For more information, please refer to the manual page of
118 "core(5)". GDB also has a new command: "set use-coredump-filter
119 on|off". It allows to set whether GDB will read the content of the
120 /proc/PID/coredump_filter file when generating a corefile.
122 * The "info os" command on GNU/Linux can now display information on
124 "info os cpus" Listing of all cpus/cores on the system
126 * GDB has two new commands: "set serial parity odd|even|none" and
127 "show serial parity". These allows to set or show parity for the
130 * The "info source" command now displays the producer string if it was
131 present in the debug info. This typically includes the compiler version
132 and may include things like its command line arguments.
134 * The "info dll", an alias of the "info sharedlibrary" command,
135 is now available on all platforms.
137 * Directory names supplied to the "set sysroot" commands may be
138 prefixed with "target:" to tell GDB to access shared libraries from
139 the target system, be it local or remote. This replaces the prefix
140 "remote:". The default sysroot has been changed from "" to
141 "target:". "remote:" is automatically converted to "target:" for
142 backward compatibility.
144 * The system root specified by "set sysroot" will be prepended to the
145 filename of the main executable (if reported to GDB as absolute by
146 the operating system) when starting processes remotely, and when
147 attaching to already-running local or remote processes.
149 * GDB now supports automatic location and retrieval of executable
150 files from remote targets. Remote debugging can now be initiated
151 using only a "target remote" or "target extended-remote" command
152 (no "set sysroot" or "file" commands are required). See "New remote
155 * The "dump" command now supports verilog hex format.
157 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
159 * On GNU/Linux, GDB and gdbserver are now able to access executable
160 and shared library files without a "set sysroot" command when
161 attaching to processes running in different mount namespaces from
162 the debugger. This makes it possible to attach to processes in
163 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
164 See "New remote packets" below.
166 * The "tui reg" command now provides completion for all of the
167 available register groups, including target specific groups.
169 * The HISTSIZE environment variable is no longer read when determining
170 the size of GDB's command history. GDB now instead reads the dedicated
171 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
172 disables truncation of command history. Non-numeric values of GDBHISTSIZE
177 ** Memory ports can now be unbuffered.
181 ** gdb.Objfile objects have a new attribute "username",
182 which is the name of the objfile as specified by the user,
183 without, for example, resolving symlinks.
184 ** You can now write frame unwinders in Python.
185 ** gdb.Type objects have a new method "optimized_out",
186 returning optimized out gdb.Value instance of this type.
187 ** gdb.Value objects have new methods "reference_value" and
188 "const_value" which return a reference to the value and a
189 "const" version of the value respectively.
193 maint print symbol-cache
194 Print the contents of the symbol cache.
196 maint print symbol-cache-statistics
197 Print statistics of symbol cache usage.
199 maint flush-symbol-cache
200 Flush the contents of the symbol cache.
204 Start branch trace recording using Branch Trace Store (BTS) format.
207 Evaluate expression by using the compiler and print result.
211 Explicit commands for enabling and disabling tui mode.
214 set mpx bound on i386 and amd64
215 Support for bound table investigation on Intel(R) MPX enabled applications.
219 Start branch trace recording using Intel(R) Processor Trace format.
222 Print information about branch tracing internals.
224 maint btrace packet-history
225 Print the raw branch tracing data.
227 maint btrace clear-packet-history
228 Discard the stored raw branch tracing data.
231 Discard all branch tracing data. It will be fetched and processed
232 anew by the next "record" command.
237 Renamed from "set debug dwarf2-die".
239 Renamed from "show debug dwarf2-die".
242 Renamed from "set debug dwarf2-read".
243 show debug dwarf-read
244 Renamed from "show debug dwarf2-read".
246 maint set dwarf always-disassemble
247 Renamed from "maint set dwarf2 always-disassemble".
248 maint show dwarf always-disassemble
249 Renamed from "maint show dwarf2 always-disassemble".
251 maint set dwarf max-cache-age
252 Renamed from "maint set dwarf2 max-cache-age".
253 maint show dwarf max-cache-age
254 Renamed from "maint show dwarf2 max-cache-age".
257 show debug dwarf-line
258 Control display of debugging info regarding DWARF line processing.
262 Set the maximum number of candidates to be considered during
263 completion. The default value is 200. This limit allows GDB
264 to avoid generating large completion lists, the computation of
265 which can cause the debugger to become temporarily unresponsive.
267 set history remove-duplicates
268 show history remove-duplicates
269 Control the removal of duplicate history entries.
271 maint set symbol-cache-size
272 maint show symbol-cache-size
273 Control the size of the symbol cache.
275 set|show record btrace bts buffer-size
276 Set and show the size of the ring buffer used for branch tracing in
278 The obtained size may differ from the requested size. Use "info
279 record" to see the obtained buffer size.
281 set debug linux-namespaces
282 show debug linux-namespaces
283 Control display of debugging info regarding Linux namespaces.
285 set|show record btrace pt buffer-size
286 Set and show the size of the ring buffer used for branch tracing in
287 Intel(R) Processor Trace format.
288 The obtained size may differ from the requested size. Use "info
289 record" to see the obtained buffer size.
291 maint set|show btrace pt skip-pad
292 Set and show whether PAD packets are skipped when computing the
295 * The command 'thread apply all' can now support new option '-ascending'
296 to call its specified command for all threads in ascending order.
298 * Python/Guile scripting
300 ** GDB now supports auto-loading of Python/Guile scripts contained in the
301 special section named `.debug_gdb_scripts'.
305 qXfer:btrace-conf:read
306 Return the branch trace configuration for the current thread.
308 Qbtrace-conf:bts:size
309 Set the requested ring buffer size for branch tracing in BTS format.
312 Enable Intel(R) Procesor Trace-based branch tracing for the current
313 process. The remote stub reports support for this packet to GDB's
317 Set the requested ring buffer size for branch tracing in Intel(R) Processor
321 Indicates a memory breakpoint instruction was executed, irrespective
322 of whether it was GDB that planted the breakpoint or the breakpoint
323 is hardcoded in the program. This is required for correct non-stop
327 Indicates the target stopped for a hardware breakpoint. This is
328 required for correct non-stop mode operation.
331 Return information about files on the remote system.
334 Return the full absolute name of the file that was executed to
335 create a process running on the remote system.
338 Select the filesystem on which vFile: operations with filename
339 arguments will operate. This is required for GDB to be able to
340 access files on remote targets where the remote stub does not
341 share a common filesystem with the inferior(s).
344 Indicates that a fork system call was executed.
347 Indicates that a vfork system call was executed.
349 vforkdone stop reason
350 Indicates that a vfork child of the specified process has executed
351 an exec or exit, allowing the vfork parent to resume execution.
353 fork-events and vfork-events features in qSupported
354 The qSupported packet allows GDB to request support for fork and
355 vfork events using new 'gdbfeatures' fork-events and vfork-events,
356 and the qSupported response can contain the corresponding
357 'stubfeatures'. Set and show commands can be used to display
358 whether these features are enabled.
360 * Extended-remote fork events
362 ** GDB now has support for fork events on extended-remote Linux
363 targets. For targets with Linux kernels 2.5.60 and later, this
364 enables follow-fork-mode and detach-on-fork for both fork and
365 vfork, as well as fork and vfork catchpoints.
367 * The info record command now shows the recording format and the
368 branch tracing configuration for the current thread when using
369 the btrace record target.
370 For the BTS format, it shows the ring buffer size.
372 * GDB now has support for DTrace USDT (Userland Static Defined
373 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
375 * GDB now supports access to vector registers on S/390 GNU/Linux
378 * Removed command line options
380 -xdb HP-UX XDB compatibility mode.
382 * Removed targets and native configurations
384 HP/PA running HP-UX hppa*-*-hpux*
385 Itanium running HP-UX ia64-*-hpux*
387 * New configure options
390 This configure option allows the user to build GDB with support for
391 Intel(R) Processor Trace (default: auto). This requires libipt.
393 --with-libipt-prefix=PATH
394 Specify the path to the version of libipt that GDB should use.
395 $PATH/include should contain the intel-pt.h header and
396 $PATH/lib should contain the libipt.so library.
398 *** Changes in GDB 7.9.1
402 ** Xmethods can now specify a result type.
404 *** Changes in GDB 7.9
406 * GDB now supports hardware watchpoints on x86 GNU Hurd.
410 ** You can now access frame registers from Python scripts.
411 ** New attribute 'producer' for gdb.Symtab objects.
412 ** gdb.Objfile objects have a new attribute "progspace",
413 which is the gdb.Progspace object of the containing program space.
414 ** gdb.Objfile objects have a new attribute "owner".
415 ** gdb.Objfile objects have a new attribute "build_id",
416 which is the build ID generated when the file was built.
417 ** gdb.Objfile objects have a new method "add_separate_debug_file".
418 ** A new event "gdb.clear_objfiles" has been added, triggered when
419 selecting a new file to debug.
420 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
421 ** New function gdb.lookup_objfile.
423 New events which are triggered when GDB modifies the state of the
426 ** gdb.events.inferior_call_pre: Function call is about to be made.
427 ** gdb.events.inferior_call_post: Function call has just been made.
428 ** gdb.events.memory_changed: A memory location has been altered.
429 ** gdb.events.register_changed: A register has been altered.
431 * New Python-based convenience functions:
433 ** $_caller_is(name [, number_of_frames])
434 ** $_caller_matches(regexp [, number_of_frames])
435 ** $_any_caller_is(name [, number_of_frames])
436 ** $_any_caller_matches(regexp [, number_of_frames])
438 * GDB now supports the compilation and injection of source code into
439 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
440 to compile the source code to object code, and if successful, inject
441 and execute that code within the current context of the inferior.
442 Currently the C language is supported. The commands used to
443 interface with this new feature are:
445 compile code [-raw|-r] [--] [source code]
446 compile file [-raw|-r] filename
450 demangle [-l language] [--] name
451 Demangle "name" in the specified language, or the current language
452 if elided. This command is renamed from the "maint demangle" command.
453 The latter is kept as a no-op to avoid "maint demangle" being interpreted
454 as "maint demangler-warning".
456 queue-signal signal-name-or-number
457 Queue a signal to be delivered to the thread when it is resumed.
459 add-auto-load-scripts-directory directory
460 Add entries to the list of directories from which to load auto-loaded
463 maint print user-registers
464 List all currently available "user" registers.
466 compile code [-r|-raw] [--] [source code]
467 Compile, inject, and execute in the inferior the executable object
468 code produced by compiling the provided source code.
470 compile file [-r|-raw] filename
471 Compile and inject into the inferior the executable object code
472 produced by compiling the source code stored in the filename
475 * On resume, GDB now always passes the signal the program had stopped
476 for to the thread the signal was sent to, even if the user changed
477 threads before resuming. Previously GDB would often (but not
478 always) deliver the signal to the thread that happens to be current
481 * Conversely, the "signal" command now consistently delivers the
482 requested signal to the current thread. GDB now asks for
483 confirmation if the program had stopped for a signal and the user
484 switched threads meanwhile.
486 * "breakpoint always-inserted" modes "off" and "auto" merged.
488 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
489 won't remove breakpoints from the target until all threads stop,
490 even in non-stop mode. The "auto" mode has been removed, and "off"
491 is now the default mode.
495 set debug symbol-lookup
496 show debug symbol-lookup
497 Control display of debugging info regarding symbol lookup.
501 ** The -list-thread-groups command outputs an exit-code field for
502 inferiors that have exited.
506 MIPS SDE mips*-sde*-elf*
510 Support for these obsolete configurations has been removed.
512 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
513 SGI Irix-5.x mips-*-irix5*
514 SGI Irix-6.x mips-*-irix6*
515 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
516 VAX running Ultrix vax-*-ultrix*
518 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
519 and "assf"), have been removed. Use the "sharedlibrary" command, or
520 its alias "share", instead.
522 *** Changes in GDB 7.8
524 * New command line options
527 This is an alias for the --data-directory option.
529 * GDB supports printing and modifying of variable length automatic arrays
530 as specified in ISO C99.
532 * The ARM simulator now supports instruction level tracing
533 with or without disassembly.
537 GDB now has support for scripting using Guile. Whether this is
538 available is determined at configure time.
539 Guile version 2.0 or greater is required.
540 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
542 * New commands (for set/show, see "New options" below)
546 Invoke CODE by passing it to the Guile interpreter.
550 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
552 info auto-load guile-scripts [regexp]
553 Print the list of automatically loaded Guile scripts.
555 * The source command is now capable of sourcing Guile scripts.
556 This feature is dependent on the debugger being built with Guile support.
560 set print symbol-loading (off|brief|full)
561 show print symbol-loading
562 Control whether to print informational messages when loading symbol
563 information for a file. The default is "full", but when debugging
564 programs with large numbers of shared libraries the amount of output
567 set guile print-stack (none|message|full)
568 show guile print-stack
569 Show a stack trace when an error is encountered in a Guile script.
571 set auto-load guile-scripts (on|off)
572 show auto-load guile-scripts
573 Control auto-loading of Guile script files.
575 maint ada set ignore-descriptive-types (on|off)
576 maint ada show ignore-descriptive-types
577 Control whether the debugger should ignore descriptive types in Ada
578 programs. The default is not to ignore the descriptive types. See
579 the user manual for more details on descriptive types and the intended
580 usage of this option.
582 set auto-connect-native-target
584 Control whether GDB is allowed to automatically connect to the
585 native target for the run, attach, etc. commands when not connected
586 to any target yet. See also "target native" below.
588 set record btrace replay-memory-access (read-only|read-write)
589 show record btrace replay-memory-access
590 Control what memory accesses are allowed during replay.
592 maint set target-async (on|off)
593 maint show target-async
594 This controls whether GDB targets operate in synchronous or
595 asynchronous mode. Normally the default is asynchronous, if it is
596 available; but this can be changed to more easily debug problems
597 occurring only in synchronous mode.
599 set mi-async (on|off)
601 Control whether MI asynchronous mode is preferred. This supersedes
602 "set target-async" of previous GDB versions.
604 * "set target-async" is deprecated as a CLI option and is now an alias
605 for "set mi-async" (only puts MI into async mode).
607 * Background execution commands (e.g., "c&", "s&", etc.) are now
608 possible ``out of the box'' if the target supports them. Previously
609 the user would need to explicitly enable the possibility with the
610 "set target-async on" command.
612 * New features in the GDB remote stub, GDBserver
614 ** New option --debug-format=option1[,option2,...] allows one to add
615 additional text to each output. At present only timestamps
616 are supported: --debug-format=timestamps.
617 Timestamps can also be turned on with the
618 "monitor set debug-format timestamps" command from GDB.
620 * The 'record instruction-history' command now starts counting instructions
621 at one. This also affects the instruction ranges reported by the
622 'record function-call-history' command when given the /i modifier.
624 * The command 'record function-call-history' supports a new modifier '/c' to
625 indent the function names based on their call stack depth.
626 The fields for the '/i' and '/l' modifier have been reordered.
627 The source line range is now prefixed with 'at'.
628 The instruction range is now prefixed with 'inst'.
629 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
630 "record instruction-history" and "list" commands.
632 * The ranges given as arguments to the 'record function-call-history' and
633 'record instruction-history' commands are now inclusive.
635 * The btrace record target now supports the 'record goto' command.
636 For locations inside the execution trace, the back trace is computed
637 based on the information stored in the execution trace.
639 * The btrace record target supports limited reverse execution and replay.
640 The target does not record data and therefore does not allow reading
643 * The "catch syscall" command now works on s390*-linux* targets.
645 * The "compare-sections" command is no longer specific to target
646 remote. It now works with all targets.
648 * All native targets are now consistently called "native".
649 Consequently, the "target child", "target GNU", "target djgpp",
650 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
651 commands have been replaced with "target native". The QNX/NTO port
652 leaves the "procfs" target in place and adds a "native" target for
653 consistency with other ports. The impact on users should be minimal
654 as these commands previously either throwed an error, or were
655 no-ops. The target's name is visible in the output of the following
656 commands: "help target", "info target", "info files", "maint print
659 * The "target native" command now connects to the native target. This
660 can be used to launch native programs even when "set
661 auto-connect-native-target" is set to off.
663 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.
665 * Support for Intel(R) AVX-512 registers on GNU/Linux.
666 Support displaying and modifying Intel(R) AVX-512 registers
667 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
671 qXfer:btrace:read's annex
672 The qXfer:btrace:read packet supports a new annex 'delta' to read
673 branch trace incrementally.
677 ** Valid Python operations on gdb.Value objects representing
678 structs/classes invoke the corresponding overloaded operators if
680 ** New `Xmethods' feature in the Python API. Xmethods are
681 additional methods or replacements for existing methods of a C++
682 class. This feature is useful for those cases where a method
683 defined in C++ source code could be inlined or optimized out by
684 the compiler, making it unavailable to GDB.
687 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
689 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
690 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
691 its alias "share", instead.
693 * The commands "set remotebaud" and "show remotebaud" are no longer
694 supported. Use "set serial baud" and "show serial baud" (respectively)
699 ** A new option "-gdb-set mi-async" replaces "-gdb-set
700 target-async". The latter is left as a deprecated alias of the
701 former for backward compatibility. If the target supports it,
702 CLI background execution commands are now always possible by
703 default, independently of whether the frontend stated a
704 preference for asynchronous execution with "-gdb-set mi-async".
705 Previously "-gdb-set target-async off" affected both MI execution
706 commands and CLI execution commands.
708 *** Changes in GDB 7.7
710 * Improved support for process record-replay and reverse debugging on
711 arm*-linux* targets. Support for thumb32 and syscall instruction
712 recording has been added.
714 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
716 * GDB now supports Fission DWP file format version 2.
717 http://gcc.gnu.org/wiki/DebugFission
719 * New convenience function "$_isvoid", to check whether an expression
720 is void. A void expression is an expression where the type of the
721 result is "void". For example, some convenience variables may be
722 "void" when evaluated (e.g., "$_exitcode" before the execution of
723 the program being debugged; or an undefined convenience variable).
724 Another example, when calling a function whose return type is
727 * The "maintenance print objfiles" command now takes an optional regexp.
729 * The "catch syscall" command now works on arm*-linux* targets.
731 * GDB now consistently shows "<not saved>" when printing values of
732 registers the debug info indicates have not been saved in the frame
733 and there's nowhere to retrieve them from
734 (callee-saved/call-clobbered registers):
739 (gdb) info registers rax
742 Before, the former would print "<optimized out>", and the latter
743 "*value not available*".
745 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
750 ** Frame filters and frame decorators have been added.
751 ** Temporary breakpoints are now supported.
752 ** Line tables representation has been added.
753 ** New attribute 'parent_type' for gdb.Field objects.
754 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
755 ** New attribute 'name' for gdb.Type objects.
759 Nios II ELF nios2*-*-elf
760 Nios II GNU/Linux nios2*-*-linux
761 Texas Instruments MSP430 msp430*-*-elf
763 * Removed native configurations
765 Support for these a.out NetBSD and OpenBSD obsolete configurations has
766 been removed. ELF variants of these configurations are kept supported.
768 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
769 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
770 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
771 i[34567]86-*-openbsd3.[0-3]
772 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
773 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
774 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
778 Like "catch throw", but catches a re-thrown exception.
780 Renamed from old "maint check-symtabs".
782 Perform consistency checks on symtabs.
784 Expand symtabs matching an optional regexp.
787 Display the details of GDB configure-time options.
789 maint set|show per-command
790 maint set|show per-command space
791 maint set|show per-command time
792 maint set|show per-command symtab
793 Enable display of per-command gdb resource usage.
795 remove-symbol-file FILENAME
796 remove-symbol-file -a ADDRESS
797 Remove a symbol file added via add-symbol-file. The file to remove
798 can be identified by its filename or by an address that lies within
799 the boundaries of this symbol file in memory.
802 info exceptions REGEXP
803 Display the list of Ada exceptions defined in the program being
804 debugged. If provided, only the exceptions whose names match REGEXP
809 set debug symfile off|on
811 Control display of debugging info regarding reading symbol files and
812 symbol tables within those files
814 set print raw frame-arguments
815 show print raw frame-arguments
816 Set/show whether to print frame arguments in raw mode,
817 disregarding any defined pretty-printers.
819 set remote trace-status-packet
820 show remote trace-status-packet
821 Set/show the use of remote protocol qTStatus packet.
825 Control display of debugging messages related to Nios II targets.
829 Control whether target-assisted range stepping is enabled.
831 set startup-with-shell
832 show startup-with-shell
833 Specifies whether Unix child processes are started via a shell or
838 Use the target memory cache for accesses to the code segment. This
839 improves performance of remote debugging (particularly disassembly).
841 * You can now use a literal value 'unlimited' for options that
842 interpret 0 or -1 as meaning "unlimited". E.g., "set
843 trace-buffer-size unlimited" is now an alias for "set
844 trace-buffer-size -1" and "set height unlimited" is now an alias for
847 * The "set debug symtab-create" debugging option of GDB has been changed to
848 accept a verbosity level. 0 means "off", 1 provides basic debugging
849 output, and values of 2 or greater provides more verbose output.
851 * New command-line options
853 Display the details of GDB configure-time options.
855 * The command 'tsave' can now support new option '-ctf' to save trace
856 buffer in Common Trace Format.
858 * Newly installed $prefix/bin/gcore acts as a shell interface for the
861 * GDB now implements the the C++ 'typeid' operator.
863 * The new convenience variable $_exception holds the exception being
864 thrown or caught at an exception-related catchpoint.
866 * The exception-related catchpoints, like "catch throw", now accept a
867 regular expression which can be used to filter exceptions by type.
869 * The new convenience variable $_exitsignal is automatically set to
870 the terminating signal number when the program being debugged dies
871 due to an uncaught signal.
875 ** All MI commands now accept an optional "--language" option.
876 Support for this feature can be verified by using the "-list-features"
877 command, which should contain "language-option".
879 ** The new command -info-gdb-mi-command allows the user to determine
880 whether a GDB/MI command is supported or not.
882 ** The "^error" result record returned when trying to execute an undefined
883 GDB/MI command now provides a variable named "code" whose content is the
884 "undefined-command" error code. Support for this feature can be verified
885 by using the "-list-features" command, which should contain
886 "undefined-command-error-code".
888 ** The -trace-save MI command can optionally save trace buffer in Common
891 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
893 ** The command -data-list-register-values now accepts an optional
894 "--skip-unavailable" option. When used, only the available registers
897 ** The new command -trace-frame-collected dumps collected variables,
898 computed expressions, tvars, memory and registers in a traceframe.
900 ** The commands -stack-list-locals, -stack-list-arguments and
901 -stack-list-variables now accept an option "--skip-unavailable".
902 When used, only the available locals or arguments are displayed.
904 ** The -exec-run command now accepts an optional "--start" option.
905 When used, the command follows the same semantics as the "start"
906 command, stopping the program's execution at the start of its
907 main subprogram. Support for this feature can be verified using
908 the "-list-features" command, which should contain
909 "exec-run-start-option".
911 ** The new commands -catch-assert and -catch-exceptions insert
912 catchpoints stopping the program when Ada exceptions are raised.
914 ** The new command -info-ada-exceptions provides the equivalent of
915 the new "info exceptions" command.
917 * New system-wide configuration scripts
918 A GDB installation now provides scripts suitable for use as system-wide
919 configuration scripts for the following systems:
923 * GDB now supports target-assigned range stepping with remote targets.
924 This improves the performance of stepping source lines by reducing
925 the number of control packets from/to GDB. See "New remote packets"
928 * GDB now understands the element 'tvar' in the XML traceframe info.
929 It has the id of the collected trace state variables.
931 * On S/390 targets that provide the transactional-execution feature,
932 the program interruption transaction diagnostic block (TDB) is now
933 represented as a number of additional "registers" in GDB.
939 The vCont packet supports a new 'r' action, that tells the remote
940 stub to step through an address range itself, without GDB
941 involvemement at each single-step.
943 qXfer:libraries-svr4:read's annex
944 The previously unused annex of the qXfer:libraries-svr4:read packet
945 is now used to support passing an argument list. The remote stub
946 reports support for this argument list to GDB's qSupported query.
947 The defined arguments are "start" and "prev", used to reduce work
948 necessary for library list updating, resulting in significant
951 * New features in the GDB remote stub, GDBserver
953 ** GDBserver now supports target-assisted range stepping. Currently
954 enabled on x86/x86_64 GNU/Linux targets.
956 ** GDBserver now adds element 'tvar' in the XML in the reply to
957 'qXfer:traceframe-info:read'. It has the id of the collected
958 trace state variables.
960 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
963 * New 'z' formatter for printing and examining memory, this displays the
964 value as hexadecimal zero padded on the left to the size of the type.
966 * GDB can now use Windows x64 unwinding data.
968 * The "set remotebaud" command has been replaced by "set serial baud".
969 Similarly, "show remotebaud" has been replaced by "show serial baud".
970 The "set remotebaud" and "show remotebaud" commands are still available
971 to provide backward compatibility with older versions of GDB.
973 *** Changes in GDB 7.6
975 * Target record has been renamed to record-full.
976 Record/replay is now enabled with the "record full" command.
977 This also affects settings that are associated with full record/replay
978 that have been moved from "set/show record" to "set/show record full":
980 set|show record full insn-number-max
981 set|show record full stop-at-limit
982 set|show record full memory-query
984 * A new record target "record-btrace" has been added. The new target
985 uses hardware support to record the control-flow of a process. It
986 does not support replaying the execution, but it implements the
987 below new commands for investigating the recorded execution log.
988 This new recording method can be enabled using:
992 The "record-btrace" target is only available on Intel Atom processors
993 and requires a Linux kernel 2.6.32 or later.
995 * Two new commands have been added for record/replay to give information
996 about the recorded execution without having to replay the execution.
997 The commands are only supported by "record btrace".
999 record instruction-history prints the execution history at
1000 instruction granularity
1002 record function-call-history prints the execution history at
1003 function granularity
1005 * New native configurations
1007 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1008 FreeBSD/powerpc powerpc*-*-freebsd
1009 x86_64/Cygwin x86_64-*-cygwin*
1010 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1014 ARM AArch64 aarch64*-*-elf
1015 ARM AArch64 GNU/Linux aarch64*-*-linux
1016 Lynx 178 PowerPC powerpc-*-lynx*178
1017 x86_64/Cygwin x86_64-*-cygwin*
1018 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1020 * If the configured location of system.gdbinit file (as given by the
1021 --with-system-gdbinit option at configure time) is in the
1022 data-directory (as specified by --with-gdb-datadir at configure
1023 time) or in one of its subdirectories, then GDB will look for the
1024 system-wide init file in the directory specified by the
1025 --data-directory command-line option.
1027 * New command line options:
1029 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1030 other initialization files, unlike -nx which disables all of them.
1032 * Removed command line options
1034 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1037 * The 'ptype' and 'whatis' commands now accept an argument to control
1040 * 'info proc' now works on some core files.
1044 ** Vectors can be created with gdb.Type.vector.
1046 ** Python's atexit.register now works in GDB.
1048 ** Types can be pretty-printed via a Python API.
1050 ** Python 3 is now supported (in addition to Python 2.4 or later)
1052 ** New class gdb.Architecture exposes GDB's internal representation
1053 of architecture in the Python API.
1055 ** New method Frame.architecture returns the gdb.Architecture object
1056 corresponding to the frame's architecture.
1058 * New Python-based convenience functions:
1060 ** $_memeq(buf1, buf2, length)
1061 ** $_streq(str1, str2)
1063 ** $_regex(str, regex)
1065 * The 'cd' command now defaults to using '~' (the home directory) if not
1068 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1069 default for GCC since November 2000.
1071 * The command 'forward-search' can now be abbreviated as 'fo'.
1073 * The command 'info tracepoints' can now display 'installed on target'
1074 or 'not installed on target' for each non-pending location of tracepoint.
1076 * New configure options
1078 --enable-libmcheck/--disable-libmcheck
1079 By default, development versions are built with -lmcheck on hosts
1080 that support it, in order to help track memory corruption issues.
1081 Release versions, on the other hand, are built without -lmcheck
1082 by default. The --enable-libmcheck/--disable-libmcheck configure
1083 options allow the user to override that default.
1084 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1085 This configure option allows the user to build GDB with
1086 libbabeltrace using which GDB can read Common Trace Format data.
1088 * New commands (for set/show, see "New options" below)
1091 Catch signals. This is similar to "handle", but allows commands and
1092 conditions to be attached.
1095 List the BFDs known to GDB.
1097 python-interactive [command]
1099 Start a Python interactive prompt, or evaluate the optional command
1100 and print the result of expressions.
1103 "py" is a new alias for "python".
1105 enable type-printer [name]...
1106 disable type-printer [name]...
1107 Enable or disable type printers.
1111 ** For the Renesas Super-H architecture, the "regs" command has been removed
1112 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1117 set print type methods (on|off)
1118 show print type methods
1119 Control whether method declarations are displayed by "ptype".
1120 The default is to show them.
1122 set print type typedefs (on|off)
1123 show print type typedefs
1124 Control whether typedef definitions are displayed by "ptype".
1125 The default is to show them.
1127 set filename-display basename|relative|absolute
1128 show filename-display
1129 Control the way in which filenames is displayed.
1130 The default is "relative", which preserves previous behavior.
1132 set trace-buffer-size
1133 show trace-buffer-size
1134 Request target to change the size of trace buffer.
1136 set remote trace-buffer-size-packet auto|on|off
1137 show remote trace-buffer-size-packet
1138 Control the use of the remote protocol `QTBuffer:size' packet.
1142 Control display of debugging messages related to ARM AArch64.
1145 set debug coff-pe-read
1146 show debug coff-pe-read
1147 Control display of debugging messages related to reading of COFF/PE
1152 Control display of debugging messages related to Mach-O symbols
1155 set debug notification
1156 show debug notification
1157 Control display of debugging info for async remote notification.
1161 ** Command parameter changes are now notified using new async record
1162 "=cmd-param-changed".
1163 ** Trace frame changes caused by command "tfind" are now notified using
1164 new async record "=traceframe-changed".
1165 ** The creation, deletion and modification of trace state variables
1166 are now notified using new async records "=tsv-created",
1167 "=tsv-deleted" and "=tsv-modified".
1168 ** The start and stop of process record are now notified using new
1169 async record "=record-started" and "=record-stopped".
1170 ** Memory changes are now notified using new async record
1172 ** The data-disassemble command response will include a "fullname" field
1173 containing the absolute file name when source has been requested.
1174 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1175 command, to allow pattern filling of memory areas.
1176 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1177 library load/unload events.
1178 ** The response to breakpoint commands and breakpoint async records
1179 includes an "installed" field containing a boolean state about each
1180 non-pending tracepoint location is whether installed on target or not.
1181 ** Output of the "-trace-status" command includes a "trace-file" field
1182 containing the name of the trace file being examined. This field is
1183 optional, and only present when examining a trace file.
1184 ** The "fullname" field is now always present along with the "file" field,
1185 even if the file cannot be found by GDB.
1187 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1188 You must have the LZMA library available when configuring GDB for this
1189 feature to be enabled. For more information, see:
1190 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1192 * New remote packets
1195 Set the size of trace buffer. The remote stub reports support for this
1196 packet to gdb's qSupported query.
1199 Enable Branch Trace Store (BTS)-based branch tracing for the current
1200 thread. The remote stub reports support for this packet to gdb's
1204 Disable branch tracing for the current thread. The remote stub reports
1205 support for this packet to gdb's qSupported query.
1208 Read the traced branches for the current thread. The remote stub
1209 reports support for this packet to gdb's qSupported query.
1211 *** Changes in GDB 7.5
1213 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1214 for more x32 ABI info.
1216 * GDB now supports access to MIPS DSP registers on Linux targets.
1218 * GDB now supports debugging microMIPS binaries.
1220 * The "info os" command on GNU/Linux can now display information on
1221 several new classes of objects managed by the operating system:
1222 "info os procgroups" lists process groups
1223 "info os files" lists file descriptors
1224 "info os sockets" lists internet-domain sockets
1225 "info os shm" lists shared-memory regions
1226 "info os semaphores" lists semaphores
1227 "info os msg" lists message queues
1228 "info os modules" lists loaded kernel modules
1230 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1231 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1232 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1233 options and inspect the probe arguments using the new $_probe_arg family
1234 of convenience variables. You can obtain more information about SystemTap
1235 in <http://sourceware.org/systemtap/>.
1237 * GDB now supports reversible debugging on ARM, it allows you to
1238 debug basic ARM and THUMB instructions, and provides
1239 record/replay support.
1241 * The option "symbol-reloading" has been deleted as it is no longer used.
1245 ** GDB commands implemented in Python can now be put in command class
1248 ** The "maint set python print-stack on|off" is now deleted.
1250 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1251 apply "flag enum"-style pretty-printing to any enum.
1253 ** gdb.lookup_symbol can now work when there is no current frame.
1255 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1256 the source at which the symbol was defined.
1258 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1259 method 'value'. The former indicates whether the symbol needs a
1260 frame in order to compute its value, and the latter computes the
1263 ** A new method 'referenced_value' on gdb.Value objects which can
1264 dereference pointer as well as C++ reference values.
1266 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1267 which return the global and static blocks (as gdb.Block objects),
1268 of the underlying symbol table, respectively.
1270 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1271 object associated with a PC value.
1273 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1274 of the address range occupied by code for the current source line.
1276 * Go language support.
1277 GDB now supports debugging programs written in the Go programming
1280 * GDBserver now supports stdio connections.
1281 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1283 * The binary "gdbtui" can no longer be built or installed.
1284 Use "gdb -tui" instead.
1286 * GDB will now print "flag" enums specially. A flag enum is one where
1287 all the enumerator values have no bits in common when pairwise
1288 "and"ed. When printing a value whose type is a flag enum, GDB will
1289 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1290 (gdb) print (enum E) 3
1293 * The filename part of a linespec will now match trailing components
1294 of a source file name. For example, "break gcc/expr.c:1000" will
1295 now set a breakpoint in build/gcc/expr.c, but not
1296 build/libcpp/expr.c.
1298 * The "info proc" and "generate-core-file" commands will now also
1299 work on remote targets connected to GDBserver on Linux.
1301 * The command "info catch" has been removed. It has been disabled
1302 since December 2007.
1304 * The "catch exception" and "catch assert" commands now accept
1305 a condition at the end of the command, much like the "break"
1306 command does. For instance:
1308 (gdb) catch exception Constraint_Error if Barrier = True
1310 Previously, it was possible to add a condition to such catchpoints,
1311 but it had to be done as a second step, after the catchpoint had been
1312 created, using the "condition" command.
1314 * The "info static-tracepoint-marker" command will now also work on
1315 native Linux targets with in-process agent.
1317 * GDB can now set breakpoints on inlined functions.
1319 * The .gdb_index section has been updated to include symbols for
1320 inlined functions. GDB will ignore older .gdb_index sections by
1321 default, which could cause symbol files to be loaded more slowly
1322 until their .gdb_index sections can be recreated. The new command
1323 "set use-deprecated-index-sections on" will cause GDB to use any older
1324 .gdb_index sections it finds. This will restore performance, but the
1325 ability to set breakpoints on inlined functions will be lost in symbol
1326 files with older .gdb_index sections.
1328 The .gdb_index section has also been updated to record more information
1329 about each symbol. This speeds up the "info variables", "info functions"
1330 and "info types" commands when used with programs having the .gdb_index
1331 section, as well as speeding up debugging with shared libraries using
1332 the .gdb_index section.
1334 * Ada support for GDB/MI Variable Objects has been added.
1336 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1341 ** New command -info-os is the MI equivalent of "info os".
1343 ** Output logs ("set logging" and related) now include MI output.
1347 ** "set use-deprecated-index-sections on|off"
1348 "show use-deprecated-index-sections on|off"
1349 Controls the use of deprecated .gdb_index sections.
1351 ** "catch load" and "catch unload" can be used to stop when a shared
1352 library is loaded or unloaded, respectively.
1354 ** "enable count" can be used to auto-disable a breakpoint after
1357 ** "info vtbl" can be used to show the virtual method tables for
1358 C++ and Java objects.
1360 ** "explore" and its sub commands "explore value" and "explore type"
1361 can be used to recursively explore values and types of
1362 expressions. These commands are available only if GDB is
1363 configured with '--with-python'.
1365 ** "info auto-load" shows status of all kinds of auto-loaded files,
1366 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1367 sequences of commands files, "info auto-load python-scripts"
1368 shows status of auto-loading Python script files,
1369 "info auto-load local-gdbinit" shows status of loading init file
1370 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1371 status of inferior specific thread debugging shared library loading.
1373 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1374 and "show auto-load-scripts" commands have been deprecated, use their
1375 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1376 and "show auto-load python-scripts" counterparts instead.
1378 ** "dprintf location,format,args..." creates a dynamic printf, which
1379 is basically a breakpoint that does a printf and immediately
1380 resumes your program's execution, so it is like a printf that you
1381 can insert dynamically at runtime instead of at compiletime.
1383 ** "set print symbol"
1385 Controls whether GDB attempts to display the symbol, if any,
1386 corresponding to addresses it prints. This defaults to "on", but
1387 you can set it to "off" to restore GDB's previous behavior.
1389 * Deprecated commands
1391 ** For the Renesas Super-H architecture, the "regs" command has been
1392 deprecated, and "info all-registers" should be used instead.
1396 Renesas RL78 rl78-*-elf
1397 HP OpenVMS ia64 ia64-hp-openvms*
1399 * GDBserver supports evaluation of breakpoint conditions. When
1400 support is advertised by GDBserver, GDB may be told to send the
1401 breakpoint conditions in bytecode form to GDBserver. GDBserver
1402 will only report the breakpoint trigger to GDB when its condition
1407 set mips compression
1408 show mips compression
1409 Select the compressed ISA encoding used in functions that have no symbol
1410 information available. The encoding can be set to either of:
1413 and is updated automatically from ELF file flags if available.
1415 set breakpoint condition-evaluation
1416 show breakpoint condition-evaluation
1417 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1418 GDBserver ("target"). Default option "auto" chooses the most efficient
1420 This option can improve debugger efficiency depending on the speed of the
1424 Disable auto-loading globally.
1427 Show auto-loading setting of all kinds of auto-loaded files.
1429 set auto-load gdb-scripts on|off
1430 show auto-load gdb-scripts
1431 Control auto-loading of GDB canned sequences of commands files.
1433 set auto-load python-scripts on|off
1434 show auto-load python-scripts
1435 Control auto-loading of Python script files.
1437 set auto-load local-gdbinit on|off
1438 show auto-load local-gdbinit
1439 Control loading of init file (.gdbinit) from current directory.
1441 set auto-load libthread-db on|off
1442 show auto-load libthread-db
1443 Control auto-loading of inferior specific thread debugging shared library.
1445 set auto-load scripts-directory <dir1>[:<dir2>...]
1446 show auto-load scripts-directory
1447 Set a list of directories from which to load auto-loaded scripts.
1448 Automatically loaded Python scripts and GDB scripts are located in one
1449 of the directories listed by this option.
1450 The delimiter (':' above) may differ according to the host platform.
1452 set auto-load safe-path <dir1>[:<dir2>...]
1453 show auto-load safe-path
1454 Set a list of directories from which it is safe to auto-load files.
1455 The delimiter (':' above) may differ according to the host platform.
1457 set debug auto-load on|off
1458 show debug auto-load
1459 Control display of debugging info for auto-loading the files above.
1461 set dprintf-style gdb|call|agent
1463 Control the way in which a dynamic printf is performed; "gdb"
1464 requests a GDB printf command, while "call" causes dprintf to call a
1465 function in the inferior. "agent" requests that the target agent
1466 (such as GDBserver) do the printing.
1468 set dprintf-function <expr>
1469 show dprintf-function
1470 set dprintf-channel <expr>
1471 show dprintf-channel
1472 Set the function and optional first argument to the call when using
1473 the "call" style of dynamic printf.
1475 set disconnected-dprintf on|off
1476 show disconnected-dprintf
1477 Control whether agent-style dynamic printfs continue to be in effect
1478 after GDB disconnects.
1480 * New configure options
1482 --with-auto-load-dir
1483 Configure default value for the 'set auto-load scripts-directory'
1484 setting above. It defaults to '$debugdir:$datadir/auto-load',
1485 $debugdir representing global debugging info directories (available
1486 via 'show debug-file-directory') and $datadir representing GDB's data
1487 directory (available via 'show data-directory').
1489 --with-auto-load-safe-path
1490 Configure default value for the 'set auto-load safe-path' setting
1491 above. It defaults to the --with-auto-load-dir setting.
1493 --without-auto-load-safe-path
1494 Set 'set auto-load safe-path' to '/', effectively disabling this
1497 * New remote packets
1499 z0/z1 conditional breakpoints extension
1501 The z0/z1 breakpoint insertion packets have been extended to carry
1502 a list of conditional expressions over to the remote stub depending on the
1503 condition evaluation mode. The use of this extension can be controlled
1504 via the "set remote conditional-breakpoints-packet" command.
1508 Specify the signals which the remote stub may pass to the debugged
1509 program without GDB involvement.
1511 * New command line options
1513 --init-command=FILE, -ix Like --command, -x but execute it
1514 before loading inferior.
1515 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1516 execute it before loading inferior.
1518 *** Changes in GDB 7.4
1520 * GDB now handles ambiguous linespecs more consistently; the existing
1521 FILE:LINE support has been expanded to other types of linespecs. A
1522 breakpoint will now be set on all matching locations in all
1523 inferiors, and locations will be added or removed according to
1526 * GDB now allows you to skip uninteresting functions and files when
1527 stepping with the "skip function" and "skip file" commands.
1529 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1530 and "show remote hardware-watchpoint-length-limit". These allows to
1531 set or show the maximum length limit (in bytes) of a remote
1532 target hardware watchpoint.
1534 This allows e.g. to use "unlimited" hardware watchpoints with the
1535 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1536 watchpoints are slower than real hardware watchpoints but are
1537 significantly faster than gdb software watchpoints.
1541 ** The register_pretty_printer function in module gdb.printing now takes
1542 an optional `replace' argument. If True, the new printer replaces any
1545 ** The "maint set python print-stack on|off" command has been
1546 deprecated and will be deleted in GDB 7.5.
1547 A new command: "set python print-stack none|full|message" has
1548 replaced it. Additionally, the default for "print-stack" is
1549 now "message", which just prints the error message without
1552 ** A prompt substitution hook (prompt_hook) is now available to the
1555 ** A new Python module, gdb.prompt has been added to the GDB Python
1556 modules library. This module provides functionality for
1557 escape sequences in prompts (used by set/show
1558 extended-prompt). These escape sequences are replaced by their
1559 corresponding value.
1561 ** Python commands and convenience-functions located in
1562 'data-directory'/python/gdb/command and
1563 'data-directory'/python/gdb/function are now automatically loaded
1566 ** Blocks now provide four new attributes. global_block and
1567 static_block will return the global and static blocks
1568 respectively. is_static and is_global are boolean attributes
1569 that indicate if the block is one of those two types.
1571 ** Symbols now provide the "type" attribute, the type of the symbol.
1573 ** The "gdb.breakpoint" function has been deprecated in favor of
1576 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1577 of a function. This class is based on the "finish" command
1578 available in the CLI.
1580 ** Type objects for struct and union types now allow access to
1581 the fields using standard Python dictionary (mapping) methods.
1582 For example, "some_type['myfield']" now works, as does
1583 "some_type.items()".
1585 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1588 ** A new function, "deep_items" has been added to the gdb.types
1589 module in the GDB Python modules library. This function returns
1590 an iterator over the fields of a struct or union type. Unlike
1591 the standard Python "iteritems" method, it will recursively traverse
1592 any anonymous fields.
1596 ** "*stopped" events can report several new "reason"s, such as
1599 ** Breakpoint changes are now notified using new async records, like
1600 "=breakpoint-modified".
1602 ** New command -ada-task-info.
1604 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1605 $sdir specifies the default system locations of shared libraries.
1606 $pdir specifies the directory where the libpthread used by the application
1609 GDB no longer looks in $sdir and $pdir after it has searched the directories
1610 mentioned in libthread-db-search-path. If you want to search those
1611 directories, they must be specified in libthread-db-search-path.
1612 The default value of libthread-db-search-path on GNU/Linux and Solaris
1613 systems is now "$sdir:$pdir".
1615 $pdir is not supported by gdbserver, it is currently ignored.
1616 $sdir is supported by gdbserver.
1618 * New configure option --with-iconv-bin.
1619 When using the internationalization support like the one in the GNU C
1620 library, GDB will invoke the "iconv" program to get a list of supported
1621 character sets. If this program lives in a non-standard location, one can
1622 use this option to specify where to find it.
1624 * When natively debugging programs on PowerPC BookE processors running
1625 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1626 watchpoints, which specify a mask in addition to an address to watch.
1627 The mask specifies that some bits of an address (the bits which are
1628 reset in the mask) should be ignored when matching the address accessed
1629 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1630 section in the user manual for more details.
1632 * The new option --once causes GDBserver to stop listening for connections once
1633 the first connection is made. The listening port used by GDBserver will
1634 become available after that.
1636 * New commands "info macros" and "alias" have been added.
1638 * New function parameters suffix @entry specifies value of function parameter
1639 at the time the function got called. Entry values are available only since
1645 "!" is now an alias of the "shell" command.
1646 Note that no space is needed between "!" and SHELL COMMAND.
1650 watch EXPRESSION mask MASK_VALUE
1651 The watch command now supports the mask argument which allows creation
1652 of masked watchpoints, if the current architecture supports this feature.
1654 info auto-load-scripts [REGEXP]
1655 This command was formerly named "maintenance print section-scripts".
1656 It is now generally useful and is no longer a maintenance-only command.
1658 info macro [-all] [--] MACRO
1659 The info macro command has new options `-all' and `--'. The first for
1660 printing all definitions of a macro. The second for explicitly specifying
1661 the end of arguments and the beginning of the macro name in case the macro
1662 name starts with a hyphen.
1664 collect[/s] EXPRESSIONS
1665 The tracepoint collect command now takes an optional modifier "/s"
1666 that directs it to dereference pointer-to-character types and
1667 collect the bytes of memory up to a zero byte. The behavior is
1668 similar to what you see when you use the regular print command on a
1669 string. An optional integer following the "/s" sets a bound on the
1670 number of bytes that will be collected.
1673 The trace start command now interprets any supplied arguments as a
1674 note to be recorded with the trace run, with an effect similar to
1675 setting the variable trace-notes.
1678 The trace stop command now interprets any arguments as a note to be
1679 mentioned along with the tstatus report that the trace was stopped
1680 with a command. The effect is similar to setting the variable
1683 * Tracepoints can now be enabled and disabled at any time after a trace
1684 experiment has been started using the standard "enable" and "disable"
1685 commands. It is now possible to start a trace experiment with no enabled
1686 tracepoints; GDB will display a warning, but will allow the experiment to
1687 begin, assuming that tracepoints will be enabled as needed while the trace
1690 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1691 locations with 4-byte instructions, when they were previously
1692 limited to locations with instructions of 5 bytes or longer.
1696 set debug dwarf2-read
1697 show debug dwarf2-read
1698 Turns on or off display of debugging messages related to reading
1699 DWARF debug info. The default is off.
1701 set debug symtab-create
1702 show debug symtab-create
1703 Turns on or off display of debugging messages related to symbol table
1704 creation. The default is off.
1707 show extended-prompt
1708 Set the GDB prompt, and allow escape sequences to be inserted to
1709 display miscellaneous information (see 'help set extended-prompt'
1710 for the list of sequences). This prompt (and any information
1711 accessed through the escape sequences) is updated every time the
1712 prompt is displayed.
1714 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1715 show print entry-values
1716 Set printing of frame argument values at function entry. In some cases
1717 GDB can determine the value of function argument which was passed by the
1718 function caller, even if the value was modified inside the called function.
1720 set debug entry-values
1721 show debug entry-values
1722 Control display of debugging info for determining frame argument values at
1723 function entry and virtual tail call frames.
1725 set basenames-may-differ
1726 show basenames-may-differ
1727 Set whether a source file may have multiple base names.
1728 (A "base name" is the name of a file with the directory part removed.
1729 Example: The base name of "/home/user/hello.c" is "hello.c".)
1730 If set, GDB will canonicalize file names (e.g., expand symlinks)
1731 before comparing them. Canonicalization is an expensive operation,
1732 but it allows the same file be known by more than one base name.
1733 If not set (the default), all source files are assumed to have just
1734 one base name, and gdb will do file name comparisons more efficiently.
1740 Set a user name and notes for the current and any future trace runs.
1741 This is useful for long-running and/or disconnected traces, to
1742 inform others (or yourself) as to who is running the trace, supply
1743 contact information, or otherwise explain what is going on.
1745 set trace-stop-notes
1746 show trace-stop-notes
1747 Set a note attached to the trace run, that is displayed when the
1748 trace has been stopped by a tstop command. This is useful for
1749 instance as an explanation, if you are stopping a trace run that was
1750 started by someone else.
1752 * New remote packets
1756 Dynamically enable a tracepoint in a started trace experiment.
1760 Dynamically disable a tracepoint in a started trace experiment.
1764 Set the user and notes of the trace run.
1768 Query the current status of a tracepoint.
1772 Query the minimum length of instruction at which a fast tracepoint may
1775 * Dcache size (number of lines) and line-size are now runtime-configurable
1776 via "set dcache line" and "set dcache line-size" commands.
1780 Texas Instruments TMS320C6x tic6x-*-*
1784 Renesas RL78 rl78-*-elf
1786 *** Changes in GDB 7.3.1
1788 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1790 *** Changes in GDB 7.3
1792 * GDB has a new command: "thread find [REGEXP]".
1793 It finds the thread id whose name, target id, or thread extra info
1794 matches the given regular expression.
1796 * The "catch syscall" command now works on mips*-linux* targets.
1798 * The -data-disassemble MI command now supports modes 2 and 3 for
1799 dumping the instruction opcodes.
1801 * New command line options
1803 -data-directory DIR Specify DIR as the "data-directory".
1804 This is mostly for testing purposes.
1806 * The "maint set python auto-load on|off" command has been renamed to
1807 "set auto-load-scripts on|off".
1809 * GDB has a new command: "set directories".
1810 It is like the "dir" command except that it replaces the
1811 source path list instead of augmenting it.
1813 * GDB now understands thread names.
1815 On GNU/Linux, "info threads" will display the thread name as set by
1816 prctl or pthread_setname_np.
1818 There is also a new command, "thread name", which can be used to
1819 assign a name internally for GDB to display.
1822 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1823 has been integrated into GDB.
1827 ** The function gdb.Write now accepts an optional keyword 'stream'.
1828 This keyword, when provided, will direct the output to either
1829 stdout, stderr, or GDB's logging output.
1831 ** Parameters can now be be sub-classed in Python, and in particular
1832 you may implement the get_set_doc and get_show_doc functions.
1833 This improves how Parameter set/show documentation is processed
1834 and allows for more dynamic content.
1836 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1837 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1838 have an is_valid method.
1840 ** Breakpoints can now be sub-classed in Python, and in particular
1841 you may implement a 'stop' function that is executed each time
1842 the inferior reaches that breakpoint.
1844 ** New function gdb.lookup_global_symbol looks up a global symbol.
1846 ** GDB values in Python are now callable if the value represents a
1847 function. For example, if 'some_value' represents a function that
1848 takes two integer parameters and returns a value, you can call
1849 that function like so:
1851 result = some_value (10,20)
1853 ** Module gdb.types has been added.
1854 It contains a collection of utilities for working with gdb.Types objects:
1855 get_basic_type, has_field, make_enum_dict.
1857 ** Module gdb.printing has been added.
1858 It contains utilities for writing and registering pretty-printers.
1859 New classes: PrettyPrinter, SubPrettyPrinter,
1860 RegexpCollectionPrettyPrinter.
1861 New function: register_pretty_printer.
1863 ** New commands "info pretty-printers", "enable pretty-printer" and
1864 "disable pretty-printer" have been added.
1866 ** gdb.parameter("directories") is now available.
1868 ** New function gdb.newest_frame returns the newest frame in the
1871 ** The gdb.InferiorThread class has a new "name" attribute. This
1872 holds the thread's name.
1874 ** Python Support for Inferior events.
1875 Python scripts can add observers to be notified of events
1876 occurring in the process being debugged.
1877 The following events are currently supported:
1878 - gdb.events.cont Continue event.
1879 - gdb.events.exited Inferior exited event.
1880 - gdb.events.stop Signal received, and Breakpoint hit events.
1884 ** GDB now puts template parameters in scope when debugging in an
1885 instantiation. For example, if you have:
1887 template<int X> int func (void) { return X; }
1889 then if you step into func<5>, "print X" will show "5". This
1890 feature requires proper debuginfo support from the compiler; it
1891 was added to GCC 4.5.
1893 ** The motion commands "next", "finish", "until", and "advance" now
1894 work better when exceptions are thrown. In particular, GDB will
1895 no longer lose control of the inferior; instead, the GDB will
1896 stop the inferior at the point at which the exception is caught.
1897 This functionality requires a change in the exception handling
1898 code that was introduced in GCC 4.5.
1900 * GDB now follows GCC's rules on accessing volatile objects when
1901 reading or writing target state during expression evaluation.
1902 One notable difference to prior behavior is that "print x = 0"
1903 no longer generates a read of x; the value of the assignment is
1904 now always taken directly from the value being assigned.
1906 * GDB now has some support for using labels in the program's source in
1907 linespecs. For instance, you can use "advance label" to continue
1908 execution to a label.
1910 * GDB now has support for reading and writing a new .gdb_index
1911 section. This section holds a fast index of DWARF debugging
1912 information and can be used to greatly speed up GDB startup and
1913 operation. See the documentation for `save gdb-index' for details.
1915 * The "watch" command now accepts an optional "-location" argument.
1916 When used, this causes GDB to watch the memory referred to by the
1917 expression. Such a watchpoint is never deleted due to it going out
1920 * GDB now supports thread debugging of core dumps on GNU/Linux.
1922 GDB now activates thread debugging using the libthread_db library
1923 when debugging GNU/Linux core dumps, similarly to when debugging
1924 live processes. As a result, when debugging a core dump file, GDB
1925 is now able to display pthread_t ids of threads. For example, "info
1926 threads" shows the same output as when debugging the process when it
1927 was live. In earlier releases, you'd see something like this:
1930 * 1 LWP 6780 main () at main.c:10
1932 While now you see this:
1935 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1937 It is also now possible to inspect TLS variables when debugging core
1940 When debugging a core dump generated on a machine other than the one
1941 used to run GDB, you may need to point GDB at the correct
1942 libthread_db library with the "set libthread-db-search-path"
1943 command. See the user manual for more details on this command.
1945 * When natively debugging programs on PowerPC BookE processors running
1946 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1947 which stop execution of the inferior whenever it executes an instruction
1948 at any address within the specified range. See the "PowerPC Embedded"
1949 section in the user manual for more details.
1951 * New features in the GDB remote stub, GDBserver
1953 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1954 and i686 LynxOS (version 5.x).
1956 ** GDBserver is now supported on Blackfin Linux.
1958 * New native configurations
1960 ia64 HP-UX ia64-*-hpux*
1964 Analog Devices, Inc. Blackfin Processor bfin-*
1966 * Ada task switching is now supported on sparc-elf targets when
1967 debugging a program using the Ravenscar Profile. For more information,
1968 see the "Tasking Support when using the Ravenscar Profile" section
1969 in the GDB user manual.
1971 * Guile support was removed.
1973 * New features in the GNU simulator
1975 ** The --map-info flag lists all known core mappings.
1977 ** CFI flashes may be simulated via the "cfi" device.
1979 *** Changes in GDB 7.2
1981 * Shared library support for remote targets by default
1983 When GDB is configured for a generic, non-OS specific target, like
1984 for example, --target=arm-eabi or one of the many *-*-elf targets,
1985 GDB now queries remote stubs for loaded shared libraries using the
1986 `qXfer:libraries:read' packet. Previously, shared library support
1987 was always disabled for such configurations.
1991 ** Argument Dependent Lookup (ADL)
1993 In C++ ADL lookup directs function search to the namespaces of its
1994 arguments even if the namespace has not been imported.
2004 Here the compiler will search for `foo' in the namespace of 'b'
2005 and find A::foo. GDB now supports this. This construct is commonly
2006 used in the Standard Template Library for operators.
2008 ** Improved User Defined Operator Support
2010 In addition to member operators, GDB now supports lookup of operators
2011 defined in a namespace and imported with a `using' directive, operators
2012 defined in the global scope, operators imported implicitly from an
2013 anonymous namespace, and the ADL operators mentioned in the previous
2015 GDB now also supports proper overload resolution for all the previously
2016 mentioned flavors of operators.
2018 ** static const class members
2020 Printing of static const class members that are initialized in the
2021 class definition has been fixed.
2023 * Windows Thread Information Block access.
2025 On Windows targets, GDB now supports displaying the Windows Thread
2026 Information Block (TIB) structure. This structure is visible either
2027 by using the new command `info w32 thread-information-block' or, by
2028 dereferencing the new convenience variable named `$_tlb', a
2029 thread-specific pointer to the TIB. This feature is also supported
2030 when remote debugging using GDBserver.
2032 * Static tracepoints
2034 Static tracepoints are calls in the user program into a tracing
2035 library. One such library is a port of the LTTng kernel tracer to
2036 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2037 When debugging with GDBserver, GDB now supports combining the GDB
2038 tracepoint machinery with such libraries. For example: the user can
2039 use GDB to probe a static tracepoint marker (a call from the user
2040 program into the tracing library) with the new "strace" command (see
2041 "New commands" below). This creates a "static tracepoint" in the
2042 breakpoint list, that can be manipulated with the same feature set
2043 as fast and regular tracepoints. E.g., collect registers, local and
2044 global variables, collect trace state variables, and define
2045 tracepoint conditions. In addition, the user can collect extra
2046 static tracepoint marker specific data, by collecting the new
2047 $_sdata internal variable. When analyzing the trace buffer, you can
2048 inspect $_sdata like any other variable available to GDB. For more
2049 information, see the "Tracepoints" chapter in GDB user manual. New
2050 remote packets have been defined to support static tracepoints, see
2051 the "New remote packets" section below.
2053 * Better reconstruction of tracepoints after disconnected tracing
2055 GDB will attempt to download the original source form of tracepoint
2056 definitions when starting a trace run, and then will upload these
2057 upon reconnection to the target, resulting in a more accurate
2058 reconstruction of the tracepoints that are in use on the target.
2062 You can now exercise direct control over the ways that GDB can
2063 affect your program. For instance, you can disallow the setting of
2064 breakpoints, so that the program can run continuously (assuming
2065 non-stop mode). In addition, the "observer" variable is available
2066 to switch all of the different controls; in observer mode, GDB
2067 cannot affect the target's behavior at all, which is useful for
2068 tasks like diagnosing live systems in the field.
2070 * The new convenience variable $_thread holds the number of the
2073 * New remote packets
2077 Return the address of the Windows Thread Information Block of a given thread.
2081 In response to several of the tracepoint packets, the target may now
2082 also respond with a number of intermediate `qRelocInsn' request
2083 packets before the final result packet, to have GDB handle
2084 relocating an instruction to execute at a different address. This
2085 is particularly useful for stubs that support fast tracepoints. GDB
2086 reports support for this feature in the qSupported packet.
2090 List static tracepoint markers in the target program.
2094 List static tracepoint markers at a given address in the target
2097 qXfer:statictrace:read
2099 Read the static trace data collected (by a `collect $_sdata'
2100 tracepoint action). The remote stub reports support for this packet
2101 to gdb's qSupported query.
2105 Send the current settings of GDB's permission flags.
2109 Send part of the source (textual) form of a tracepoint definition,
2110 which includes location, conditional, and action list.
2112 * The source command now accepts a -s option to force searching for the
2113 script in the source search path even if the script name specifies
2116 * New features in the GDB remote stub, GDBserver
2118 - GDBserver now support tracepoints (including fast tracepoints, and
2119 static tracepoints). The feature is currently supported by the
2120 i386-linux and amd64-linux builds. See the "Tracepoints support
2121 in gdbserver" section in the manual for more information.
2123 GDBserver JIT compiles the tracepoint's conditional agent
2124 expression bytecode into native code whenever possible for low
2125 overhead dynamic tracepoints conditionals. For such tracepoints,
2126 an expression that examines program state is evaluated when the
2127 tracepoint is reached, in order to determine whether to capture
2128 trace data. If the condition is simple and false, processing the
2129 tracepoint finishes very quickly and no data is gathered.
2131 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2132 for static tracepoints support.
2134 - GDBserver now supports x86_64 Windows 64-bit debugging.
2136 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2137 it understands register description.
2139 * The --batch flag now disables pagination and queries.
2141 * X86 general purpose registers
2143 GDB now supports reading/writing byte, word and double-word x86
2144 general purpose registers directly. This means you can use, say,
2145 $ah or $ax to refer, respectively, to the byte register AH and
2146 16-bit word register AX that are actually portions of the 32-bit
2147 register EAX or 64-bit register RAX.
2149 * The `commands' command now accepts a range of breakpoints to modify.
2150 A plain `commands' following a command that creates multiple
2151 breakpoints affects all the breakpoints set by that command. This
2152 applies to breakpoints set by `rbreak', and also applies when a
2153 single `break' command creates multiple breakpoints (e.g.,
2154 breakpoints on overloaded c++ functions).
2156 * The `rbreak' command now accepts a filename specification as part of
2157 its argument, limiting the functions selected by the regex to those
2158 in the specified file.
2160 * Support for remote debugging Windows and SymbianOS shared libraries
2161 from Unix hosts has been improved. Non Windows GDB builds now can
2162 understand target reported file names that follow MS-DOS based file
2163 system semantics, such as file names that include drive letters and
2164 use the backslash character as directory separator. This makes it
2165 possible to transparently use the "set sysroot" and "set
2166 solib-search-path" on Unix hosts to point as host copies of the
2167 target's shared libraries. See the new command "set
2168 target-file-system-kind" described below, and the "Commands to
2169 specify files" section in the user manual for more information.
2173 eval template, expressions...
2174 Convert the values of one or more expressions under the control
2175 of the string template to a command line, and call it.
2177 set target-file-system-kind unix|dos-based|auto
2178 show target-file-system-kind
2179 Set or show the assumed file system kind for target reported file
2182 save breakpoints <filename>
2183 Save all current breakpoint definitions to a file suitable for use
2184 in a later debugging session. To read the saved breakpoint
2185 definitions, use the `source' command.
2187 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2190 info static-tracepoint-markers
2191 Display information about static tracepoint markers in the target.
2193 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2194 Define a static tracepoint by probing a marker at the given
2195 function, line, address, or marker ID.
2199 Enable and disable observer mode.
2201 set may-write-registers on|off
2202 set may-write-memory on|off
2203 set may-insert-breakpoints on|off
2204 set may-insert-tracepoints on|off
2205 set may-insert-fast-tracepoints on|off
2206 set may-interrupt on|off
2207 Set individual permissions for GDB effects on the target. Note that
2208 some of these settings can have undesirable or surprising
2209 consequences, particularly when changed in the middle of a session.
2210 For instance, disabling the writing of memory can prevent
2211 breakpoints from being inserted, cause single-stepping to fail, or
2212 even crash your program, if you disable after breakpoints have been
2213 inserted. However, GDB should not crash.
2215 set record memory-query on|off
2216 show record memory-query
2217 Control whether to stop the inferior if memory changes caused
2218 by an instruction cannot be recorded.
2223 The disassemble command now supports "start,+length" form of two arguments.
2227 ** GDB now provides a new directory location, called the python directory,
2228 where Python scripts written for GDB can be installed. The location
2229 of that directory is <data-directory>/python, where <data-directory>
2230 is the GDB data directory. For more details, see section `Scripting
2231 GDB using Python' in the manual.
2233 ** The GDB Python API now has access to breakpoints, symbols, symbol
2234 tables, program spaces, inferiors, threads and frame's code blocks.
2235 Additionally, GDB Parameters can now be created from the API, and
2236 manipulated via set/show in the CLI.
2238 ** New functions gdb.target_charset, gdb.target_wide_charset,
2239 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2241 ** New exception gdb.GdbError.
2243 ** Pretty-printers are now also looked up in the current program space.
2245 ** Pretty-printers can now be individually enabled and disabled.
2247 ** GDB now looks for names of Python scripts to auto-load in a
2248 special section named `.debug_gdb_scripts', in addition to looking
2249 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2251 * Tracepoint actions were unified with breakpoint commands. In particular,
2252 there are no longer differences in "info break" output for breakpoints and
2253 tracepoints and the "commands" command can be used for both tracepoints and
2254 regular breakpoints.
2258 ARM Symbian arm*-*-symbianelf*
2260 * D language support.
2261 GDB now supports debugging programs written in the D programming
2264 * GDB now supports the extended ptrace interface for PowerPC which is
2265 available since Linux kernel version 2.6.34. This automatically enables
2266 any hardware breakpoints and additional hardware watchpoints available in
2267 the processor. The old ptrace interface exposes just one hardware
2268 watchpoint and no hardware breakpoints.
2270 * GDB is now able to use the Data Value Compare (DVC) register available on
2271 embedded PowerPC processors to implement in hardware simple watchpoint
2272 conditions of the form:
2274 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2276 This works in native GDB running on Linux kernels with the extended ptrace
2277 interface mentioned above.
2279 *** Changes in GDB 7.1
2283 ** Namespace Support
2285 GDB now supports importing of namespaces in C++. This enables the
2286 user to inspect variables from imported namespaces. Support for
2287 namepace aliasing has also been added. So, if a namespace is
2288 aliased in the current scope (e.g. namepace C=A; ) the user can
2289 print variables using the alias (e.g. (gdb) print C::x).
2293 All known bugs relating to the printing of virtual base class were
2294 fixed. It is now possible to call overloaded static methods using a
2299 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2300 and reinterpret_cast<> are now handled by the C++ expression parser.
2304 Xilinx MicroBlaze microblaze-*-*
2309 Xilinx MicroBlaze microblaze
2312 * Multi-program debugging.
2314 GDB now has support for multi-program (a.k.a. multi-executable or
2315 multi-exec) debugging. This allows for debugging multiple inferiors
2316 simultaneously each running a different program under the same GDB
2317 session. See "Debugging Multiple Inferiors and Programs" in the
2318 manual for more information. This implied some user visible changes
2319 in the multi-inferior support. For example, "info inferiors" now
2320 lists inferiors that are not running yet or that have exited
2321 already. See also "New commands" and "New options" below.
2323 * New tracing features
2325 GDB's tracepoint facility now includes several new features:
2327 ** Trace state variables
2329 GDB tracepoints now include support for trace state variables, which
2330 are variables managed by the target agent during a tracing
2331 experiment. They are useful for tracepoints that trigger each
2332 other, so for instance one tracepoint can count hits in a variable,
2333 and then a second tracepoint has a condition that is true when the
2334 count reaches a particular value. Trace state variables share the
2335 $-syntax of GDB convenience variables, and can appear in both
2336 tracepoint actions and condition expressions. Use the "tvariable"
2337 command to create, and "info tvariables" to view; see "Trace State
2338 Variables" in the manual for more detail.
2342 GDB now includes an option for defining fast tracepoints, which
2343 targets may implement more efficiently, such as by installing a jump
2344 into the target agent rather than a trap instruction. The resulting
2345 speedup can be by two orders of magnitude or more, although the
2346 tradeoff is that some program locations on some target architectures
2347 might not allow fast tracepoint installation, for instance if the
2348 instruction to be replaced is shorter than the jump. To request a
2349 fast tracepoint, use the "ftrace" command, with syntax identical to
2350 the regular trace command.
2352 ** Disconnected tracing
2354 It is now possible to detach GDB from the target while it is running
2355 a trace experiment, then reconnect later to see how the experiment
2356 is going. In addition, a new variable disconnected-tracing lets you
2357 tell the target agent whether to continue running a trace if the
2358 connection is lost unexpectedly.
2362 GDB now has the ability to save the trace buffer into a file, and
2363 then use that file as a target, similarly to you can do with
2364 corefiles. You can select trace frames, print data that was
2365 collected in them, and use tstatus to display the state of the
2366 tracing run at the moment that it was saved. To create a trace
2367 file, use "tsave <filename>", and to use it, do "target tfile
2370 ** Circular trace buffer
2372 You can ask the target agent to handle the trace buffer as a
2373 circular buffer, discarding the oldest trace frames to make room for
2374 newer ones, by setting circular-trace-buffer to on. This feature may
2375 not be available for all target agents.
2380 The disassemble command, when invoked with two arguments, now requires
2381 the arguments to be comma-separated.
2384 The info variables command now displays variable definitions. Files
2385 which only declare a variable are not shown.
2388 The source command is now capable of sourcing Python scripts.
2389 This feature is dependent on the debugger being build with Python
2392 Related to this enhancement is also the introduction of a new command
2393 "set script-extension" (see below).
2395 * New commands (for set/show, see "New options" below)
2397 record save [<FILENAME>]
2398 Save a file (in core file format) containing the process record
2399 execution log for replay debugging at a later time.
2401 record restore <FILENAME>
2402 Restore the process record execution log that was saved at an
2403 earlier time, for replay debugging.
2405 add-inferior [-copies <N>] [-exec <FILENAME>]
2408 clone-inferior [-copies <N>] [ID]
2409 Make a new inferior ready to execute the same program another
2410 inferior has loaded.
2415 maint info program-spaces
2416 List the program spaces loaded into GDB.
2418 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2419 show remote interrupt-sequence
2420 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2421 as the sequence to the remote target in order to interrupt the execution.
2422 Ctrl-C is a default. Some system prefers BREAK which is high level of
2423 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2424 Magic SysRq g. It is BREAK signal and character 'g'.
2426 set remote interrupt-on-connect [on | off]
2427 show remote interrupt-on-connect
2428 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2429 remote target when gdb connects to it. This is needed when you debug
2432 set remotebreak [on | off]
2434 Deprecated. Use "set/show remote interrupt-sequence" instead.
2436 tvariable $NAME [ = EXP ]
2437 Create or modify a trace state variable.
2440 List trace state variables and their values.
2442 delete tvariable $NAME ...
2443 Delete one or more trace state variables.
2446 Evaluate the given expressions without collecting anything into the
2447 trace buffer. (Valid in tracepoint actions only.)
2449 ftrace FN / FILE:LINE / *ADDR
2450 Define a fast tracepoint at the given function, line, or address.
2452 * New expression syntax
2454 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2455 GDB now parses 0b101010 identically with 42.
2459 set follow-exec-mode new|same
2460 show follow-exec-mode
2461 Control whether GDB reuses the same inferior across an exec call or
2462 creates a new one. This is useful to be able to restart the old
2463 executable after the inferior having done an exec call.
2465 set default-collect EXPR, ...
2466 show default-collect
2467 Define a list of expressions to be collected at each tracepoint.
2468 This is a useful way to ensure essential items are not overlooked,
2469 such as registers or a critical global variable.
2471 set disconnected-tracing
2472 show disconnected-tracing
2473 If set to 1, the target is instructed to continue tracing if it
2474 loses its connection to GDB. If 0, the target is to stop tracing
2477 set circular-trace-buffer
2478 show circular-trace-buffer
2479 If set to on, the target is instructed to use a circular trace buffer
2480 and discard the oldest trace frames instead of stopping the trace due
2481 to a full trace buffer. If set to off, the trace stops when the buffer
2482 fills up. Some targets may not support this.
2484 set script-extension off|soft|strict
2485 show script-extension
2486 If set to "off", the debugger does not perform any script language
2487 recognition, and all sourced files are assumed to be GDB scripts.
2488 If set to "soft" (the default), files are sourced according to
2489 filename extension, falling back to GDB scripts if the first
2491 If set to "strict", files are sourced according to filename extension.
2493 set ada trust-PAD-over-XVS on|off
2494 show ada trust-PAD-over-XVS
2495 If off, activate a workaround against a bug in the debugging information
2496 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2497 the GCC sources for more information about the GNAT encoding and
2498 PAD types in particular). It is always safe to set this option to
2499 off, but this introduces a slight performance penalty. The default
2502 * Python API Improvements
2504 ** GDB provides the new class gdb.LazyString. This is useful in
2505 some pretty-printing cases. The new method gdb.Value.lazy_string
2506 provides a simple way to create objects of this type.
2508 ** The fields returned by gdb.Type.fields now have an
2509 `is_base_class' attribute.
2511 ** The new method gdb.Type.range returns the range of an array type.
2513 ** The new method gdb.parse_and_eval can be used to parse and
2514 evaluate an expression.
2516 * New remote packets
2519 Define a trace state variable.
2522 Get the current value of a trace state variable.
2525 Set desired tracing behavior upon disconnection.
2528 Set the trace buffer to be linear or circular.
2531 Get data about the tracepoints currently in use.
2535 Process record now works correctly with hardware watchpoints.
2537 Multiple bug fixes have been made to the mips-irix port, making it
2538 much more reliable. In particular:
2539 - Debugging threaded applications is now possible again. Previously,
2540 GDB would hang while starting the program, or while waiting for
2541 the program to stop at a breakpoint.
2542 - Attaching to a running process no longer hangs.
2543 - An error occurring while loading a core file has been fixed.
2544 - Changing the value of the PC register now works again. This fixes
2545 problems observed when using the "jump" command, or when calling
2546 a function from GDB, or even when assigning a new value to $pc.
2547 - With the "finish" and "return" commands, the return value for functions
2548 returning a small array is now correctly printed.
2549 - It is now possible to break on shared library code which gets executed
2550 during a shared library init phase (code executed while executing
2551 their .init section). Previously, the breakpoint would have no effect.
2552 - GDB is now able to backtrace through the signal handler for
2553 non-threaded programs.
2555 PIE (Position Independent Executable) programs debugging is now supported.
2556 This includes debugging execution of PIC (Position Independent Code) shared
2557 libraries although for that, it should be possible to run such libraries as an
2560 *** Changes in GDB 7.0
2562 * GDB now has an interface for JIT compilation. Applications that
2563 dynamically generate code can create symbol files in memory and register
2564 them with GDB. For users, the feature should work transparently, and
2565 for JIT developers, the interface is documented in the GDB manual in the
2566 "JIT Compilation Interface" chapter.
2568 * Tracepoints may now be conditional. The syntax is as for
2569 breakpoints; either an "if" clause appended to the "trace" command,
2570 or the "condition" command is available. GDB sends the condition to
2571 the target for evaluation using the same bytecode format as is used
2572 for tracepoint actions.
2574 * The disassemble command now supports: an optional /r modifier, print the
2575 raw instructions in hex as well as in symbolic form, and an optional /m
2576 modifier to print mixed source+assembly.
2578 * Process record and replay
2580 In a architecture environment that supports ``process record and
2581 replay'', ``process record and replay'' target can record a log of
2582 the process execution, and replay it with both forward and reverse
2585 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2586 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2587 set execution-direction {forward|reverse}, for targets that support
2590 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2591 feature is available with a native GDB running on kernel version
2594 * GDB now has support for multi-byte and wide character sets on the
2595 target. Strings whose character type is wchar_t, char16_t, or
2596 char32_t are now correctly printed. GDB supports wide- and unicode-
2597 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2598 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2599 `printf'. This feature requires iconv to work properly; if your
2600 system does not have a working iconv, GDB can use GNU libiconv. See
2601 the installation instructions for more information.
2603 * GDB now supports automatic retrieval of shared library files from
2604 remote targets. To use this feature, specify a system root that begins
2605 with the `remote:' prefix, either via the `set sysroot' command or via
2606 the `--with-sysroot' configure-time option.
2608 * "info sharedlibrary" now takes an optional regex of libraries to show,
2609 and it now reports if a shared library has no debugging information.
2611 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2612 now complete on file names.
2614 * When completing in expressions, gdb will attempt to limit
2615 completions to allowable structure or union fields, where appropriate.
2616 For instance, consider:
2618 # struct example { int f1; double f2; };
2619 # struct example variable;
2622 If the user types TAB at the end of this command line, the available
2623 completions will be "f1" and "f2".
2625 * Inlined functions are now supported. They show up in backtraces, and
2626 the "step", "next", and "finish" commands handle them automatically.
2628 * GDB now supports the token-splicing (##) and stringification (#)
2629 operators when expanding macros. It also supports variable-arity
2632 * GDB now supports inspecting extra signal information, exported by
2633 the new $_siginfo convenience variable. The feature is currently
2634 implemented on linux ARM, i386 and amd64.
2636 * GDB can now display the VFP floating point registers and NEON vector
2637 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2638 can provide these registers (requires Linux 2.6.30 or later). Remote
2639 and simulator targets may also provide them.
2641 * New remote packets
2644 Search memory for a sequence of bytes.
2647 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2648 operation over reliable transport links. Use of this packet is
2649 controlled by the `set remote noack-packet' command.
2652 Kill the process with the specified process ID. Use this in preference
2653 to `k' when multiprocess protocol extensions are supported.
2656 Obtains additional operating system information
2660 Read or write additional signal information.
2662 * Removed remote protocol undocumented extension
2664 An undocumented extension to the remote protocol's `S' stop reply
2665 packet that permited the stub to pass a process id was removed.
2666 Remote servers should use the `T' stop reply packet instead.
2668 * GDB now supports multiple function calling conventions according to the
2669 DWARF-2 DW_AT_calling_convention function attribute.
2671 * The SH target utilizes the aforementioned change to distinguish between gcc
2672 and Renesas calling convention. It also adds the new CLI commands
2673 `set/show sh calling-convention'.
2675 * GDB can now read compressed debug sections, as produced by GNU gold
2676 with the --compress-debug-sections=zlib flag.
2678 * 64-bit core files are now supported on AIX.
2680 * Thread switching is now supported on Tru64.
2682 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2683 which will be allocated using malloc later in program execution.
2685 * The qXfer:libraries:read remote procotol packet now allows passing a
2686 list of section offsets.
2688 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2689 conditions handling signals delivered during attach or thread creation
2690 have also been fixed.
2692 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2693 From the user's standpoint, all unqualified instances of True and False
2694 are treated as the standard definitions, regardless of context.
2696 * GDB now parses C++ symbol and type names more flexibly. For
2699 template<typename T> class C { };
2702 GDB will now correctly handle all of:
2704 ptype C<char const *>
2705 ptype C<char const*>
2706 ptype C<const char *>
2707 ptype C<const char*>
2709 * New features in the GDB remote stub, gdbserver
2711 - The "--wrapper" command-line argument tells gdbserver to use a
2712 wrapper program to launch programs for debugging.
2714 - On PowerPC and S/390 targets, it is now possible to use a single
2715 gdbserver executable to debug both 32-bit and 64-bit programs.
2716 (This requires gdbserver itself to be built as a 64-bit executable.)
2718 - gdbserver uses the new noack protocol mode for TCP connections to
2719 reduce communications latency, if also supported and enabled in GDB.
2721 - Support for the sparc64-linux-gnu target is now included in
2724 - The amd64-linux build of gdbserver now supports debugging both
2725 32-bit and 64-bit programs.
2727 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2728 now support hardware watchpoints, and will use them automatically
2733 GDB now has support for scripting using Python. Whether this is
2734 available is determined at configure time.
2736 New GDB commands can now be written in Python.
2738 * Ada tasking support
2740 Ada tasks can now be inspected in GDB. The following commands have
2744 Print the list of Ada tasks.
2746 Print detailed information about task number N.
2748 Print the task number of the current task.
2750 Switch the context of debugging to task number N.
2752 * Support for user-defined prefixed commands. The "define" command can
2753 add new commands to existing prefixes, e.g. "target".
2755 * Multi-inferior, multi-process debugging.
2757 GDB now has generalized support for multi-inferior debugging. See
2758 "Debugging Multiple Inferiors" in the manual for more information.
2759 Although availability still depends on target support, the command
2760 set is more uniform now. The GNU/Linux specific multi-forks support
2761 has been migrated to this new framework. This implied some user
2762 visible changes; see "New commands" and also "Removed commands"
2765 * Target descriptions can now describe the target OS ABI. See the
2766 "Target Description Format" section in the user manual for more
2769 * Target descriptions can now describe "compatible" architectures
2770 to indicate that the target can execute applications for a different
2771 architecture in addition to those for the main target architecture.
2772 See the "Target Description Format" section in the user manual for
2775 * Multi-architecture debugging.
2777 GDB now includes general supports for debugging applications on
2778 hybrid systems that use more than one single processor architecture
2779 at the same time. Each such hybrid architecture still requires
2780 specific support to be added. The only hybrid architecture supported
2781 in this version of GDB is the Cell Broadband Engine.
2783 * GDB now supports integrated debugging of Cell/B.E. applications that
2784 use both the PPU and SPU architectures. To enable support for hybrid
2785 Cell/B.E. debugging, you need to configure GDB to support both the
2786 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2787 --enable-targets configure option.
2789 * Non-stop mode debugging.
2791 For some targets, GDB now supports an optional mode of operation in
2792 which you can examine stopped threads while other threads continue
2793 to execute freely. This is referred to as non-stop mode, with the
2794 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2795 section in the user manual for more information.
2797 To be able to support remote non-stop debugging, a remote stub needs
2798 to implement the non-stop mode remote protocol extensions, as
2799 described in the "Remote Non-Stop" section of the user manual. The
2800 GDB remote stub, gdbserver, has been adjusted to support these
2801 extensions on linux targets.
2803 * New commands (for set/show, see "New options" below)
2805 catch syscall [NAME(S) | NUMBER(S)]
2806 Catch system calls. Arguments, which should be names of system
2807 calls or their numbers, mean catch only those syscalls. Without
2808 arguments, every syscall will be caught. When the inferior issues
2809 any of the specified syscalls, GDB will stop and announce the system
2810 call, both when it is called and when its call returns. This
2811 feature is currently available with a native GDB running on the
2812 Linux Kernel, under the following architectures: x86, x86_64,
2813 PowerPC and PowerPC64.
2815 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2817 Search memory for a sequence of bytes.
2819 maint set python print-stack
2820 maint show python print-stack
2821 Show a stack trace when an error is encountered in a Python script.
2824 Invoke CODE by passing it to the Python interpreter.
2829 These allow macros to be defined, undefined, and listed
2833 Show operating system information about processes.
2836 List the inferiors currently under GDB's control.
2839 Switch focus to inferior number NUM.
2842 Detach from inferior number NUM.
2845 Kill inferior number NUM.
2849 set spu stop-on-load
2850 show spu stop-on-load
2851 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2853 set spu auto-flush-cache
2854 show spu auto-flush-cache
2855 Control whether to automatically flush the software-managed cache
2856 during Cell/B.E. debugging.
2858 set sh calling-convention
2859 show sh calling-convention
2860 Control the calling convention used when calling SH target functions.
2863 show debug timestamp
2864 Control display of timestamps with GDB debugging output.
2866 set disassemble-next-line
2867 show disassemble-next-line
2868 Control display of disassembled source lines or instructions when
2871 set remote noack-packet
2872 show remote noack-packet
2873 Set/show the use of remote protocol QStartNoAckMode packet. See above
2874 under "New remote packets."
2876 set remote query-attached-packet
2877 show remote query-attached-packet
2878 Control use of remote protocol `qAttached' (query-attached) packet.
2880 set remote read-siginfo-object
2881 show remote read-siginfo-object
2882 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2885 set remote write-siginfo-object
2886 show remote write-siginfo-object
2887 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2890 set remote reverse-continue
2891 show remote reverse-continue
2892 Control use of remote protocol 'bc' (reverse-continue) packet.
2894 set remote reverse-step
2895 show remote reverse-step
2896 Control use of remote protocol 'bs' (reverse-step) packet.
2898 set displaced-stepping
2899 show displaced-stepping
2900 Control displaced stepping mode. Displaced stepping is a way to
2901 single-step over breakpoints without removing them from the debuggee.
2902 Also known as "out-of-line single-stepping".
2905 show debug displaced
2906 Control display of debugging info for displaced stepping.
2908 maint set internal-error
2909 maint show internal-error
2910 Control what GDB does when an internal error is detected.
2912 maint set internal-warning
2913 maint show internal-warning
2914 Control what GDB does when an internal warning is detected.
2919 Use a wrapper program to launch programs for debugging.
2921 set multiple-symbols (all|ask|cancel)
2922 show multiple-symbols
2923 The value of this variable can be changed to adjust the debugger behavior
2924 when an expression or a breakpoint location contains an ambiguous symbol
2925 name (an overloaded function name, for instance).
2927 set breakpoint always-inserted
2928 show breakpoint always-inserted
2929 Keep breakpoints always inserted in the target, as opposed to inserting
2930 them when resuming the target, and removing them when the target stops.
2931 This option can improve debugger performance on slow remote targets.
2933 set arm fallback-mode (arm|thumb|auto)
2934 show arm fallback-mode
2935 set arm force-mode (arm|thumb|auto)
2937 These commands control how ARM GDB determines whether instructions
2938 are ARM or Thumb. The default for both settings is auto, which uses
2939 the current CPSR value for instructions without symbols; previous
2940 versions of GDB behaved as if "set arm fallback-mode arm".
2942 set disable-randomization
2943 show disable-randomization
2944 Standalone programs run with the virtual address space randomization enabled
2945 by default on some platforms. This option keeps the addresses stable across
2946 multiple debugging sessions.
2950 Control whether other threads are stopped or not when some thread hits
2955 Requests that asynchronous execution is enabled in the target, if available.
2956 In this case, it's possible to resume target in the background, and interact
2957 with GDB while the target is running. "show target-async" displays the
2958 current state of asynchronous execution of the target.
2960 set target-wide-charset
2961 show target-wide-charset
2962 The target-wide-charset is the name of the character set that GDB
2963 uses when printing characters whose type is wchar_t.
2965 set tcp auto-retry (on|off)
2967 set tcp connect-timeout
2968 show tcp connect-timeout
2969 These commands allow GDB to retry failed TCP connections to a remote stub
2970 with a specified timeout period; this is useful if the stub is launched
2971 in parallel with GDB but may not be ready to accept connections immediately.
2973 set libthread-db-search-path
2974 show libthread-db-search-path
2975 Control list of directories which GDB will search for appropriate
2978 set schedule-multiple (on|off)
2979 show schedule-multiple
2980 Allow GDB to resume all threads of all processes or only threads of
2981 the current process.
2985 Use more aggressive caching for accesses to the stack. This improves
2986 performance of remote debugging (particularly backtraces) without
2987 affecting correctness.
2989 set interactive-mode (on|off|auto)
2990 show interactive-mode
2991 Control whether GDB runs in interactive mode (on) or not (off).
2992 When in interactive mode, GDB waits for the user to answer all
2993 queries. Otherwise, GDB does not wait and assumes the default
2994 answer. When set to auto (the default), GDB determines which
2995 mode to use based on the stdin settings.
3000 For program forks, this is replaced by the new more generic `info
3001 inferiors' command. To list checkpoints, you can still use the
3002 `info checkpoints' command, which was an alias for the `info forks'
3006 Replaced by the new `inferior' command. To switch between
3007 checkpoints, you can still use the `restart' command, which was an
3008 alias for the `fork' command.
3011 This is removed, since some targets don't have a notion of
3012 processes. To switch between processes, you can still use the
3013 `inferior' command using GDB's own inferior number.
3016 For program forks, this is replaced by the new more generic `kill
3017 inferior' command. To delete a checkpoint, you can still use the
3018 `delete checkpoint' command, which was an alias for the `delete
3022 For program forks, this is replaced by the new more generic `detach
3023 inferior' command. To detach a checkpoint, you can still use the
3024 `detach checkpoint' command, which was an alias for the `detach
3027 * New native configurations
3029 x86/x86_64 Darwin i[34567]86-*-darwin*
3031 x86_64 MinGW x86_64-*-mingw*
3035 Lattice Mico32 lm32-*
3036 x86 DICOS i[34567]86-*-dicos*
3037 x86_64 DICOS x86_64-*-dicos*
3040 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3041 (mingw32ce) debugging.
3047 These commands were actually not implemented on any target.
3049 *** Changes in GDB 6.8
3051 * New native configurations
3053 NetBSD/hppa hppa*-*netbsd*
3054 Xtensa GNU/Linux xtensa*-*-linux*
3058 NetBSD/hppa hppa*-*-netbsd*
3059 Xtensa GNU/Lunux xtensa*-*-linux*
3061 * Change in command line behavior -- corefiles vs. process ids.
3063 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3064 attaching to process NUMBER fails, GDB no longer attempts to open a
3065 core file named NUMBER. Attaching to a program using the -c option
3066 is no longer supported. Instead, use the '-p' or '--pid' options.
3068 * GDB can now be built as a native debugger for debugging Windows x86
3069 (mingw32) Portable Executable (PE) programs.
3071 * Pending breakpoints no longer change their number when their address
3074 * GDB now supports breakpoints with multiple locations,
3075 including breakpoints on C++ constructors, inside C++ templates,
3076 and in inlined functions.
3078 * GDB's ability to debug optimized code has been improved. GDB more
3079 accurately identifies function bodies and lexical blocks that occupy
3080 more than one contiguous range of addresses.
3082 * Target descriptions can now describe registers for PowerPC.
3084 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3085 registers on PowerPC targets.
3087 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3088 targets even when the libthread_db library is not available.
3090 * The GDB remote stub, gdbserver, now supports the new file transfer
3091 commands (remote put, remote get, and remote delete).
3093 * The GDB remote stub, gdbserver, now supports run and attach in
3094 extended-remote mode.
3096 * hppa*64*-*-hpux11* target broken
3097 The debugger is unable to start a program and fails with the following
3098 error: "Error trying to get information about dynamic linker".
3099 The gdb-6.7 release is also affected.
3101 * GDB now supports the --enable-targets= configure option to allow
3102 building a single GDB executable that supports multiple remote
3103 target architectures.
3105 * GDB now supports debugging C and C++ programs which use the
3106 Decimal Floating Point extension. In addition, the PowerPC target
3107 now has a set of pseudo-registers to inspect decimal float values
3108 stored in two consecutive float registers.
3110 * The -break-insert MI command can optionally create pending
3113 * Improved support for debugging Ada
3114 Many improvements to the Ada language support have been made. These
3116 - Better support for Ada2005 interface types
3117 - Improved handling of arrays and slices in general
3118 - Better support for Taft-amendment types
3119 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3121 - Improved command completion in Ada
3124 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3129 set print frame-arguments (all|scalars|none)
3130 show print frame-arguments
3131 The value of this variable can be changed to control which argument
3132 values should be printed by the debugger when displaying a frame.
3137 Transfer files to and from a remote target, and delete remote files.
3144 Transfer files to and from a remote target, and delete remote files.
3146 * New remote packets
3153 Open, close, read, write, and delete files on the remote system.
3156 Attach to an existing process on the remote system, in extended-remote
3160 Run a new process on the remote system, in extended-remote mode.
3162 *** Changes in GDB 6.7
3164 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3165 bfd, libiberty and opcodes, as revealed by static analysis donated by
3166 Coverity, Inc. (http://scan.coverity.com).
3168 * When looking up multiply-defined global symbols, GDB will now prefer the
3169 symbol definition in the current shared library if it was built using the
3170 -Bsymbolic linker option.
3172 * When the Text User Interface (TUI) is not configured, GDB will now
3173 recognize the -tui command-line option and print a message that the TUI
3176 * The GDB remote stub, gdbserver, now has lower overhead for high
3177 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3179 * GDB for MIPS targets now autodetects whether a remote target provides
3180 32-bit or 64-bit register values.
3182 * Support for C++ member pointers has been improved.
3184 * GDB now understands XML target descriptions, which specify the
3185 target's overall architecture. GDB can read a description from
3186 a local file or over the remote serial protocol.
3188 * Vectors of single-byte data use a new integer type which is not
3189 automatically displayed as character or string data.
3191 * The /s format now works with the print command. It displays
3192 arrays of single-byte integers and pointers to single-byte integers
3195 * Target descriptions can now describe target-specific registers,
3196 for architectures which have implemented the support (currently
3197 only ARM, M68K, and MIPS).
3199 * GDB and the GDB remote stub, gdbserver, now support the XScale
3202 * The GDB remote stub, gdbserver, has been updated to support
3203 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3204 has been rewritten to use the standard GDB remote protocol.
3206 * GDB can now step into C++ functions which are called through thunks.
3208 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3210 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3211 layout. It also supports a TextSeg= and DataSeg= response when only
3212 segment base addresses (rather than offsets) are available.
3214 * The /i format now outputs any trailing branch delay slot instructions
3215 immediately following the last instruction within the count specified.
3217 * The GDB remote protocol "T" stop reply packet now supports a
3218 "library" response. Combined with the new "qXfer:libraries:read"
3219 packet, this response allows GDB to debug shared libraries on targets
3220 where the operating system manages the list of loaded libraries (e.g.
3221 Windows and SymbianOS).
3223 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3224 (DLLs) on Windows and Windows CE targets.
3226 * GDB now supports a faster verification that a .debug file matches its binary
3227 according to its build-id signature, if the signature is present.
3233 Enable or disable hardware flow control (RTS/CTS) on the serial port
3234 when debugging using remote targets.
3236 set mem inaccessible-by-default
3237 show mem inaccessible-by-default
3238 If the target supplies a memory map, for instance via the remote
3239 protocol's "qXfer:memory-map:read" packet, setting this variable
3240 prevents GDB from accessing memory outside the memory map. This
3241 is useful for targets with memory mapped registers or which react
3242 badly to accesses of unmapped address space.
3244 set breakpoint auto-hw
3245 show breakpoint auto-hw
3246 If the target supplies a memory map, for instance via the remote
3247 protocol's "qXfer:memory-map:read" packet, setting this variable
3248 lets GDB use hardware breakpoints automatically for memory regions
3249 where it can not use software breakpoints. This covers both the
3250 "break" command and internal breakpoints used for other commands
3251 including "next" and "finish".
3254 catch exception unhandled
3255 Stop the program execution when Ada exceptions are raised.
3258 Stop the program execution when an Ada assertion failed.
3262 Set an alternate system root for target files. This is a more
3263 general version of "set solib-absolute-prefix", which is now
3264 an alias to "set sysroot".
3267 Provide extended SPU facility status information. This set of
3268 commands is available only when debugging the Cell/B.E. SPU
3271 * New native configurations
3273 OpenBSD/sh sh*-*openbsd*
3276 unset tdesc filename
3278 Use the specified local file as an XML target description, and do
3279 not query the target for its built-in description.
3283 OpenBSD/sh sh*-*-openbsd*
3284 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3285 Toshiba Media Processor mep-elf
3287 * New remote packets
3290 Ignore the specified signals; pass them directly to the debugged program
3291 without stopping other threads or reporting them to GDB.
3293 qXfer:features:read:
3294 Read an XML target description from the target, which describes its
3299 Read or write contents of an spufs file on the target system. These
3300 packets are available only on the Cell/B.E. SPU architecture.
3302 qXfer:libraries:read:
3303 Report the loaded shared libraries. Combined with new "T" packet
3304 response, this packet allows GDB to debug shared libraries on
3305 targets where the operating system manages the list of loaded
3306 libraries (e.g. Windows and SymbianOS).
3310 Support for these obsolete configurations has been removed.
3318 i[34567]86-*-lynxos*
3319 i[34567]86-*-netware*
3320 i[34567]86-*-sco3.2v5*
3321 i[34567]86-*-sco3.2v4*
3323 i[34567]86-*-sysv4.2*
3326 i[34567]86-*-unixware2*
3327 i[34567]86-*-unixware*
3336 * Other removed features
3343 Various m68k-only ROM monitors.
3350 Various Renesas ROM monitors and debugging interfaces for SH and
3355 Support for a Macraigor serial interface to on-chip debugging.
3356 GDB does not directly support the newer parallel or USB
3361 A debug information format. The predecessor to DWARF 2 and
3362 DWARF 3, which are still supported.
3364 Support for the HP aCC compiler on HP-UX/PA-RISC
3366 SOM-encapsulated symbolic debugging information, automatic
3367 invocation of pxdb, and the aCC custom C++ ABI. This does not
3368 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3369 with aCC can still be debugged on an assembly level.
3371 MIPS ".pdr" sections
3373 A MIPS-specific format used to describe stack frame layout
3374 in debugging information.
3378 GDB could work with an older version of Guile to debug
3379 the interpreter and Scheme programs running in it.
3381 set mips stack-arg-size
3382 set mips saved-gpreg-size
3384 Use "set mips abi" to control parameter passing for MIPS.
3386 *** Changes in GDB 6.6
3391 Cell Broadband Engine SPU spu-elf
3393 * GDB can now be configured as a cross-debugger targeting native Windows
3394 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3395 running on a Windows system over TCP/IP to debug Windows programs.
3397 * The GDB remote stub, gdbserver, has been updated to support Windows and
3398 Cygwin debugging. Both single-threaded and multi-threaded programs are
3401 * The "set trust-readonly-sections" command works again. This command was
3402 broken in GDB 6.3, 6.4, and 6.5.
3404 * The "load" command now supports writing to flash memory, if the remote
3405 stub provides the required support.
3407 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3408 longer requires symbolic debug information (e.g. DWARF-2).
3413 unset substitute-path
3414 show substitute-path
3415 Manage a list of substitution rules that GDB uses to rewrite the name
3416 of the directories where the sources are located. This can be useful
3417 for instance when the sources were moved to a different location
3418 between compilation and debugging.
3422 Print each CLI command as it is executed. Each command is prefixed with
3423 a number of `+' symbols representing the nesting depth.
3424 The source command now has a `-v' option to enable the same feature.
3428 The ARM Demon monitor support (RDP protocol, "target rdp").
3430 Kernel Object Display, an embedded debugging feature which only worked with
3431 an obsolete version of Cisco IOS.
3433 The 'set download-write-size' and 'show download-write-size' commands.
3435 * New remote packets
3438 Tell a stub about GDB client features, and request remote target features.
3439 The first feature implemented is PacketSize, which allows the target to
3440 specify the size of packets it can handle - to minimize the number of
3441 packets required and improve performance when connected to a remote
3445 Fetch an OS auxilliary vector from the remote stub. This packet is a
3446 more efficient replacement for qPart:auxv:read.
3448 qXfer:memory-map:read:
3449 Fetch a memory map from the remote stub, including information about
3450 RAM, ROM, and flash memory devices.
3455 Erase and program a flash memory device.
3457 * Removed remote packets
3460 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3461 used it, and only gdbserver implemented it.
3463 *** Changes in GDB 6.5
3467 Renesas M32C/M16C m32c-elf
3469 Morpho Technologies ms1 ms1-elf
3473 init-if-undefined Initialize a convenience variable, but
3474 only if it doesn't already have a value.
3476 The following commands are presently only implemented for native GNU/Linux:
3478 checkpoint Save a snapshot of the program state.
3480 restart <n> Return the program state to a
3481 previously saved state.
3483 info checkpoints List currently saved checkpoints.
3485 delete-checkpoint <n> Delete a previously saved checkpoint.
3487 set|show detach-on-fork Tell gdb whether to detach from a newly
3488 forked process, or to keep debugging it.
3490 info forks List forks of the user program that
3491 are available to be debugged.
3493 fork <n> Switch to debugging one of several
3494 forks of the user program that are
3495 available to be debugged.
3497 delete-fork <n> Delete a fork from the list of forks
3498 that are available to be debugged (and
3499 kill the forked process).
3501 detach-fork <n> Delete a fork from the list of forks
3502 that are available to be debugged (and
3503 allow the process to continue).
3507 Morpho Technologies ms2 ms1-elf
3509 * Improved Windows host support
3511 GDB now builds as a cross debugger hosted on i686-mingw32, including
3512 native console support, and remote communications using either
3513 network sockets or serial ports.
3515 * Improved Modula-2 language support
3517 GDB can now print most types in the Modula-2 syntax. This includes:
3518 basic types, set types, record types, enumerated types, range types,
3519 pointer types and ARRAY types. Procedure var parameters are correctly
3520 printed and hexadecimal addresses and character constants are also
3521 written in the Modula-2 syntax. Best results can be obtained by using
3522 GNU Modula-2 together with the -gdwarf-2 command line option.
3526 The ARM rdi-share module.
3528 The Netware NLM debug server.
3530 *** Changes in GDB 6.4
3532 * New native configurations
3534 OpenBSD/arm arm*-*-openbsd*
3535 OpenBSD/mips64 mips64-*-openbsd*
3539 Morpho Technologies ms1 ms1-elf
3541 * New command line options
3543 --batch-silent As for --batch, but totally silent.
3544 --return-child-result The debugger will exist with the same value
3545 the child (debugged) program exited with.
3546 --eval-command COMMAND, -ex COMMAND
3547 Execute a single GDB CLI command. This may be
3548 specified multiple times and in conjunction
3549 with the --command (-x) option.
3551 * Deprecated commands removed
3553 The following commands, that were deprecated in 2000, have been
3557 set|show arm disassembly-flavor set|show arm disassembler
3558 othernames set arm disassembler
3559 set|show remotedebug set|show debug remote
3560 set|show archdebug set|show debug arch
3561 set|show eventdebug set|show debug event
3564 * New BSD user-level threads support
3566 It is now possible to debug programs using the user-level threads
3567 library on OpenBSD and FreeBSD. Currently supported (target)
3570 FreeBSD/amd64 x86_64-*-freebsd*
3571 FreeBSD/i386 i386-*-freebsd*
3572 OpenBSD/i386 i386-*-openbsd*
3574 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3575 are not yet supported.
3577 * New support for Matsushita MN10300 w/sim added
3578 (Work in progress). mn10300-elf.
3580 * REMOVED configurations and files
3582 VxWorks and the XDR protocol *-*-vxworks
3583 Motorola MCORE mcore-*-*
3584 National Semiconductor NS32000 ns32k-*-*
3586 * New "set print array-indexes" command
3588 After turning this setting "on", GDB prints the index of each element
3589 when displaying arrays. The default is "off" to preserve the previous
3592 * VAX floating point support
3594 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3596 * User-defined command support
3598 In addition to using $arg0..$arg9 for argument passing, it is now possible
3599 to use $argc to determine now many arguments have been passed. See the
3600 section on user-defined commands in the user manual for more information.
3602 *** Changes in GDB 6.3:
3604 * New command line option
3606 GDB now accepts -l followed by a number to set the timeout for remote
3609 * GDB works with GCC -feliminate-dwarf2-dups
3611 GDB now supports a more compact representation of DWARF-2 debug
3612 information using DW_FORM_ref_addr references. These are produced
3613 by GCC with the option -feliminate-dwarf2-dups and also by some
3614 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3615 to use -feliminate-dwarf2-dups.
3617 * Internationalization
3619 When supported by the host system, GDB will be built with
3620 internationalization (libintl). The task of marking up the sources is
3621 continued, we're looking forward to our first translation.
3625 Initial support for debugging programs compiled with the GNAT
3626 implementation of the Ada programming language has been integrated
3627 into GDB. In this release, support is limited to expression evaluation.
3629 * New native configurations
3631 GNU/Linux/m32r m32r-*-linux-gnu
3635 GDB's remote protocol now includes support for the 'p' packet. This
3636 packet is used to fetch individual registers from a remote inferior.
3638 * END-OF-LIFE registers[] compatibility module
3640 GDB's internal register infrastructure has been completely rewritten.
3641 The new infrastructure making possible the implementation of key new
3642 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3645 GDB 6.3 will be the last release to include the the registers[]
3646 compatibility module that allowed out-of-date configurations to
3647 continue to work. This change directly impacts the following
3657 powerpc bdm protocol
3659 Unless there is activity to revive these configurations, they will be
3660 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3662 * OBSOLETE configurations and files
3664 Configurations that have been declared obsolete in this release have
3665 been commented out. Unless there is activity to revive these
3666 configurations, the next release of GDB will have their sources
3667 permanently REMOVED.
3676 *** Changes in GDB 6.2.1:
3678 * MIPS `break main; run' gave an heuristic-fence-post warning
3680 When attempting to run even a simple program, a warning about
3681 heuristic-fence-post being hit would be reported. This problem has
3684 * MIPS IRIX 'long double' crashed GDB
3686 When examining a long double variable, GDB would get a segmentation
3687 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3688 IRIX long double values).
3692 A bug in the VAX stack code was causing problems with the "next"
3693 command. This problem has been fixed.
3695 *** Changes in GDB 6.2:
3697 * Fix for ``many threads''
3699 On GNU/Linux systems that use the NPTL threads library, a program
3700 rapidly creating and deleting threads would confuse GDB leading to the
3703 ptrace: No such process.
3704 thread_db_get_info: cannot get thread info: generic error
3706 This problem has been fixed.
3708 * "-async" and "-noasync" options removed.
3710 Support for the broken "-noasync" option has been removed (it caused
3713 * New ``start'' command.
3715 This command runs the program until the begining of the main procedure.
3717 * New BSD Kernel Data Access Library (libkvm) interface
3719 Using ``target kvm'' it is now possible to debug kernel core dumps and
3720 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3721 platforms. Currently supported (native-only) configurations are:
3723 FreeBSD/amd64 x86_64-*-freebsd*
3724 FreeBSD/i386 i?86-*-freebsd*
3725 NetBSD/i386 i?86-*-netbsd*
3726 NetBSD/m68k m68*-*-netbsd*
3727 NetBSD/sparc sparc-*-netbsd*
3728 OpenBSD/amd64 x86_64-*-openbsd*
3729 OpenBSD/i386 i?86-*-openbsd*
3730 OpenBSD/m68k m68*-openbsd*
3731 OpenBSD/sparc sparc-*-openbsd*
3733 * Signal trampoline code overhauled
3735 Many generic problems with GDB's signal handling code have been fixed.
3736 These include: backtraces through non-contiguous stacks; recognition
3737 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3738 call; backtrace through a signal trampoline; step into and out of
3739 signal handlers; and single-stepping in the signal trampoline.
3741 Please note that kernel bugs are a limiting factor here. These
3742 features have been shown to work on an s390 GNU/Linux system that
3743 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3745 * Cygwin support for DWARF 2 added.
3747 * New native configurations
3749 GNU/Linux/hppa hppa*-*-linux*
3750 OpenBSD/hppa hppa*-*-openbsd*
3751 OpenBSD/m68k m68*-*-openbsd*
3752 OpenBSD/m88k m88*-*-openbsd*
3753 OpenBSD/powerpc powerpc-*-openbsd*
3754 NetBSD/vax vax-*-netbsd*
3755 OpenBSD/vax vax-*-openbsd*
3757 * END-OF-LIFE frame compatibility module
3759 GDB's internal frame infrastructure has been completely rewritten.
3760 The new infrastructure making it possible to support key new features
3761 including DWARF 2 Call Frame Information. To aid in the task of
3762 migrating old configurations to this new infrastructure, a
3763 compatibility module, that allowed old configurations to continue to
3764 work, was also included.
3766 GDB 6.2 will be the last release to include this frame compatibility
3767 module. This change directly impacts the following configurations:
3777 Unless there is activity to revive these configurations, they will be
3778 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3780 * REMOVED configurations and files
3782 Sun 3, running SunOS 3 m68*-*-sunos3*
3783 Sun 3, running SunOS 4 m68*-*-sunos4*
3784 Sun 2, running SunOS 3 m68000-*-sunos3*
3785 Sun 2, running SunOS 4 m68000-*-sunos4*
3786 Motorola 680x0 running LynxOS m68*-*-lynxos*
3787 AT&T 3b1/Unix pc m68*-att-*
3788 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3789 decstation mips-dec-* mips-little-*
3790 riscos mips-*-riscos* mips-*-sysv*
3791 sonymips mips-sony-*
3792 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3794 *** Changes in GDB 6.1.1:
3796 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3798 The TUI (Text-mode User Interface) is now built as part of a default
3799 GDB configuration. It is enabled by either selecting the TUI with the
3800 command line option "-i=tui" or by running the separate "gdbtui"
3801 program. For more information on the TUI, see the manual "Debugging
3804 * Pending breakpoint support (also included in GDB 6.1)
3806 Support has been added to allow you to specify breakpoints in shared
3807 libraries that have not yet been loaded. If a breakpoint location
3808 cannot be found, and the "breakpoint pending" option is set to auto,
3809 GDB queries you if you wish to make the breakpoint pending on a future
3810 shared-library load. If and when GDB resolves the breakpoint symbol,
3811 the pending breakpoint is removed as one or more regular breakpoints
3814 Pending breakpoints are very useful for GCJ Java debugging.
3816 * Fixed ISO-C build problems
3818 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3819 non ISO-C code that stopped them being built using a more strict ISO-C
3820 compiler (e.g., IBM's C compiler).
3822 * Fixed build problem on IRIX 5
3824 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3825 wasn't able to compile compile on an IRIX 5 system.
3827 * Added execute permission to gdb/gdbserver/configure
3829 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3830 permission. This bug would cause configure to fail on a number of
3831 systems (Solaris, IRIX). Ref: server/519.
3833 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3835 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3836 has been updated to use constant array sizes.
3838 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3840 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3841 its generated DWARF Call Frame Info. This encoding was causing GDB to
3842 panic, that panic has been fixed. Ref: gdb/1628.
3844 * Fixed a problem when examining parameters in shared library code.
3846 When examining parameters in optimized shared library code generated
3847 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3848 not available''. GDB now correctly displays the variable's value.
3850 *** Changes in GDB 6.1:
3852 * Removed --with-mmalloc
3854 Support for the mmalloc memory manager has been removed, as it
3855 conflicted with the internal gdb byte cache.
3857 * Changes in AMD64 configurations
3859 The AMD64 target now includes the %cs and %ss registers. As a result
3860 the AMD64 remote protocol has changed; this affects the floating-point
3861 and SSE registers. If you rely on those registers for your debugging,
3862 you should upgrade gdbserver on the remote side.
3864 * Revised SPARC target
3866 The SPARC target has been completely revised, incorporating the
3867 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3868 support for LynxOS and SunOS 4 has been dropped. Calling functions
3869 from within GDB on operating systems with a non-executable stack
3870 (Solaris, OpenBSD) now works.
3874 GDB has a new C++ demangler which does a better job on the mangled
3875 names generated by current versions of g++. It also runs faster, so
3876 with this and other changes gdb should now start faster on large C++
3879 * DWARF 2 Location Expressions
3881 GDB support for location expressions has been extended to support function
3882 arguments and frame bases. Older versions of GDB could crash when they
3885 * C++ nested types and namespaces
3887 GDB's support for nested types and namespaces in C++ has been
3888 improved, especially if you use the DWARF 2 debugging format. (This
3889 is the default for recent versions of GCC on most platforms.)
3890 Specifically, if you have a class "Inner" defined within a class or
3891 namespace "Outer", then GDB realizes that the class's name is
3892 "Outer::Inner", not simply "Inner". This should greatly reduce the
3893 frequency of complaints about not finding RTTI symbols. In addition,
3894 if you are stopped at inside of a function defined within a namespace,
3895 GDB modifies its name lookup accordingly.
3897 * New native configurations
3899 NetBSD/amd64 x86_64-*-netbsd*
3900 OpenBSD/amd64 x86_64-*-openbsd*
3901 OpenBSD/alpha alpha*-*-openbsd*
3902 OpenBSD/sparc sparc-*-openbsd*
3903 OpenBSD/sparc64 sparc64-*-openbsd*
3905 * New debugging protocols
3907 M32R with SDI protocol m32r-*-elf*
3909 * "set prompt-escape-char" command deleted.
3911 The command "set prompt-escape-char" has been deleted. This command,
3912 and its very obscure effet on GDB's prompt, was never documented,
3913 tested, nor mentioned in the NEWS file.
3915 * OBSOLETE configurations and files
3917 Configurations that have been declared obsolete in this release have
3918 been commented out. Unless there is activity to revive these
3919 configurations, the next release of GDB will have their sources
3920 permanently REMOVED.
3922 Sun 3, running SunOS 3 m68*-*-sunos3*
3923 Sun 3, running SunOS 4 m68*-*-sunos4*
3924 Sun 2, running SunOS 3 m68000-*-sunos3*
3925 Sun 2, running SunOS 4 m68000-*-sunos4*
3926 Motorola 680x0 running LynxOS m68*-*-lynxos*
3927 AT&T 3b1/Unix pc m68*-att-*
3928 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3929 decstation mips-dec-* mips-little-*
3930 riscos mips-*-riscos* mips-*-sysv*
3931 sonymips mips-sony-*
3932 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3934 * REMOVED configurations and files
3936 SGI Irix-4.x mips-sgi-irix4 or iris4
3937 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3938 Z8000 simulator z8k-zilog-none or z8ksim
3939 Matsushita MN10200 w/simulator mn10200-*-*
3940 H8/500 simulator h8500-hitachi-hms or h8500hms
3941 HP/PA running BSD hppa*-*-bsd*
3942 HP/PA running OSF/1 hppa*-*-osf*
3943 HP/PA Pro target hppa*-*-pro*
3944 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3945 386BSD i[3456]86-*-bsd*
3946 Sequent family i[3456]86-sequent-sysv4*
3947 i[3456]86-sequent-sysv*
3948 i[3456]86-sequent-bsd*
3949 SPARC running LynxOS sparc-*-lynxos*
3950 SPARC running SunOS 4 sparc-*-sunos4*
3951 Tsqware Sparclet sparclet-*-*
3952 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3954 *** Changes in GDB 6.0:
3958 Support for debugging the Objective-C programming language has been
3959 integrated into GDB.
3961 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3963 DWARF 2's Call Frame Information makes available compiler generated
3964 information that more exactly describes the program's run-time stack.
3965 By using this information, GDB is able to provide more robust stack
3968 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3969 have been updated to use a new backtrace mechanism which includes
3970 DWARF 2 CFI support.
3974 GDB's remote protocol has been extended to include support for hosted
3975 file I/O (where the remote target uses GDB's file system). See GDB's
3976 remote protocol documentation for details.
3978 * All targets using the new architecture framework.
3980 All of GDB's targets have been updated to use the new internal
3981 architecture framework. The way is now open for future GDB releases
3982 to include cross-architecture native debugging support (i386 on amd64,
3985 * GNU/Linux's Thread Local Storage (TLS)
3987 GDB now includes support for for the GNU/Linux implementation of
3988 per-thread variables.
3990 * GNU/Linux's Native POSIX Thread Library (NPTL)
3992 GDB's thread code has been updated to work with either the new
3993 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3995 * Separate debug info.
3997 GDB, in conjunction with BINUTILS, now supports a mechanism for
3998 automatically loading debug information from a separate file. Instead
3999 of shipping full debug and non-debug versions of system libraries,
4000 system integrators can now instead ship just the stripped libraries
4001 and optional debug files.
4003 * DWARF 2 Location Expressions
4005 DWARF 2 Location Expressions allow the compiler to more completely
4006 describe the location of variables (even in optimized code) to the
4009 GDB now includes preliminary support for location expressions (support
4010 for DW_OP_piece is still missing).
4014 A number of long standing bugs that caused GDB to die while starting a
4015 Java application have been fixed. GDB's Java support is now
4016 considered "useable".
4018 * GNU/Linux support for fork, vfork, and exec.
4020 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4021 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4024 * GDB supports logging output to a file
4026 There are two new commands, "set logging" and "show logging", which can be
4027 used to capture GDB's output to a file.
4029 * The meaning of "detach" has changed for gdbserver
4031 The "detach" command will now resume the application, as documented. To
4032 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4035 * d10v, m68hc11 `regs' command deprecated
4037 The `info registers' command has been updated so that it displays the
4038 registers using a format identical to the old `regs' command.
4042 A new command, "maint set profile on/off", has been added. This command can
4043 be used to enable or disable profiling while running GDB, to profile a
4044 session or a set of commands. In addition there is a new configure switch,
4045 "--enable-profiling", which will cause GDB to be compiled with profiling
4046 data, for more informative profiling results.
4048 * Default MI syntax changed to "mi2".
4050 The default MI (machine interface) syntax, enabled by the command line
4051 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4052 "mi1", can be enabled by specifying the option "-i=mi1".
4054 Support for the original "mi0" syntax (included in GDB 5.0) has been
4057 Fix for gdb/192: removed extraneous space when displaying frame level.
4058 Fix for gdb/672: update changelist is now output in mi list format.
4059 Fix for gdb/702: a -var-assign that updates the value now shows up
4060 in a subsequent -var-update.
4062 * New native configurations.
4064 FreeBSD/amd64 x86_64-*-freebsd*
4066 * Multi-arched targets.
4068 HP/PA HPUX11 hppa*-*-hpux*
4069 Renesas M32R/D w/simulator m32r-*-elf*
4071 * OBSOLETE configurations and files
4073 Configurations that have been declared obsolete in this release have
4074 been commented out. Unless there is activity to revive these
4075 configurations, the next release of GDB will have their sources
4076 permanently REMOVED.
4078 Z8000 simulator z8k-zilog-none or z8ksim
4079 Matsushita MN10200 w/simulator mn10200-*-*
4080 H8/500 simulator h8500-hitachi-hms or h8500hms
4081 HP/PA running BSD hppa*-*-bsd*
4082 HP/PA running OSF/1 hppa*-*-osf*
4083 HP/PA Pro target hppa*-*-pro*
4084 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4085 Sequent family i[3456]86-sequent-sysv4*
4086 i[3456]86-sequent-sysv*
4087 i[3456]86-sequent-bsd*
4088 Tsqware Sparclet sparclet-*-*
4089 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4091 * REMOVED configurations and files
4094 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4095 IBM AIX PS/2 i[3456]86-*-aix
4096 i386 running Mach 3.0 i[3456]86-*-mach3*
4097 i386 running Mach i[3456]86-*-mach*
4098 i386 running OSF/1 i[3456]86-*osf1mk*
4099 HP/Apollo 68k Family m68*-apollo*-sysv*,
4101 m68*-hp-bsd*, m68*-hp-hpux*
4102 Argonaut Risc Chip (ARC) arc-*-*
4103 Mitsubishi D30V d30v-*-*
4104 Fujitsu FR30 fr30-*-elf*
4105 OS/9000 i[34]86-*-os9k
4106 I960 with MON960 i960-*-coff
4108 * MIPS $fp behavior changed
4110 The convenience variable $fp, for the MIPS, now consistently returns
4111 the address of the current frame's base. Previously, depending on the
4112 context, $fp could refer to either $sp or the current frame's base
4113 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4114 The GNU Source-Level Debugger''.
4116 *** Changes in GDB 5.3:
4118 * GNU/Linux shared library multi-threaded performance improved.
4120 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4121 `/proc', in preference to `ptrace' for memory reads. This may result
4122 in an improvement in the start-up time of multi-threaded, shared
4123 library applications when run under GDB. One GDB user writes: ``loads
4124 shared libs like mad''.
4126 * ``gdbserver'' now supports multi-threaded applications on some targets
4128 Support for debugging multi-threaded applications which use
4129 the GNU/Linux LinuxThreads package has been added for
4130 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4131 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4133 * GDB now supports C/C++ preprocessor macros.
4135 GDB now expands preprocessor macro invocations in C/C++ expressions,
4136 and provides various commands for showing macro definitions and how
4139 The new command `macro expand EXPRESSION' expands any macro
4140 invocations in expression, and shows the result.
4142 The new command `show macro MACRO-NAME' shows the definition of the
4143 macro named MACRO-NAME, and where it was defined.
4145 Most compilers don't include information about macros in the debugging
4146 information by default. In GCC 3.1, for example, you need to compile
4147 your program with the options `-gdwarf-2 -g3'. If the macro
4148 information is present in the executable, GDB will read it.
4150 * Multi-arched targets.
4152 DEC Alpha (partial) alpha*-*-*
4153 DEC VAX (partial) vax-*-*
4155 National Semiconductor NS32000 (partial) ns32k-*-*
4156 Motorola 68000 (partial) m68k-*-*
4157 Motorola MCORE mcore-*-*
4161 Fujitsu FRV architecture added by Red Hat frv*-*-*
4164 * New native configurations
4166 Alpha NetBSD alpha*-*-netbsd*
4167 SH NetBSD sh*-*-netbsdelf*
4168 MIPS NetBSD mips*-*-netbsd*
4169 UltraSPARC NetBSD sparc64-*-netbsd*
4171 * OBSOLETE configurations and files
4173 Configurations that have been declared obsolete in this release have
4174 been commented out. Unless there is activity to revive these
4175 configurations, the next release of GDB will have their sources
4176 permanently REMOVED.
4178 Mitsubishi D30V d30v-*-*
4179 OS/9000 i[34]86-*-os9k
4180 IBM AIX PS/2 i[3456]86-*-aix
4181 Fujitsu FR30 fr30-*-elf*
4182 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4183 Argonaut Risc Chip (ARC) arc-*-*
4184 i386 running Mach 3.0 i[3456]86-*-mach3*
4185 i386 running Mach i[3456]86-*-mach*
4186 i386 running OSF/1 i[3456]86-*osf1mk*
4187 HP/Apollo 68k Family m68*-apollo*-sysv*,
4189 m68*-hp-bsd*, m68*-hp-hpux*
4190 I960 with MON960 i960-*-coff
4192 * OBSOLETE languages
4194 CHILL, a Pascal like language used by telecommunications companies.
4196 * REMOVED configurations and files
4198 AMD 29k family via UDI a29k-amd-udi, udi29k
4199 A29K VxWorks a29k-*-vxworks
4200 AMD 29000 embedded, using EBMON a29k-none-none
4201 AMD 29000 embedded with COFF a29k-none-coff
4202 AMD 29000 embedded with a.out a29k-none-aout
4204 testsuite/gdb.hp/gdb.threads-hp/ directory
4206 * New command "set max-user-call-depth <nnn>"
4208 This command allows the user to limit the call depth of user-defined
4209 commands. The default is 1024.
4211 * Changes in FreeBSD/i386 native debugging.
4213 Support for the "generate-core-file" has been added.
4215 * New commands "dump", "append", and "restore".
4217 These commands allow data to be copied from target memory
4218 to a bfd-format or binary file (dump and append), and back
4219 from a file into memory (restore).
4221 * Improved "next/step" support on multi-processor Alpha Tru64.
4223 The previous single-step mechanism could cause unpredictable problems,
4224 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4225 of a software single-step mechanism prevents this.
4227 *** Changes in GDB 5.2.1:
4235 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4236 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4237 Fix, by Joel Brobecker imported from mainline.
4239 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4240 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4241 Fix, by Fred Fish, imported from mainline.
4243 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4244 Surprisingly enough, it works now.
4245 By Michal Ludvig, imported from mainline.
4247 i386 hardware watchpoint support:
4248 avoid misses on second run for some targets.
4249 By Pierre Muller, imported from mainline.
4251 *** Changes in GDB 5.2:
4253 * New command "set trust-readonly-sections on[off]".
4255 This command is a hint that tells gdb that read-only sections
4256 really are read-only (ie. that their contents will not change).
4257 In this mode, gdb will go to the object file rather than the
4258 target to read memory from read-only sections (such as ".text").
4259 This can be a significant performance improvement on some
4260 (notably embedded) targets.
4262 * New command "generate-core-file" (or "gcore").
4264 This new gdb command allows the user to drop a core file of the child
4265 process state at any time. So far it's been implemented only for
4266 GNU/Linux and Solaris, but should be relatively easily ported to other
4267 hosts. Argument is core file name (defaults to core.<pid>).
4269 * New command line option
4271 GDB now accepts --pid or -p followed by a process id.
4273 * Change in command line behavior -- corefiles vs. process ids.
4275 There is a subtle behavior in the way in which GDB handles
4276 command line arguments. The first non-flag argument is always
4277 a program to debug, but the second non-flag argument may either
4278 be a corefile or a process id. Previously, GDB would attempt to
4279 open the second argument as a corefile, and if that failed, would
4280 issue a superfluous error message and then attempt to attach it as
4281 a process. Now, if the second argument begins with a non-digit,
4282 it will be treated as a corefile. If it begins with a digit,
4283 GDB will attempt to attach it as a process, and if no such process
4284 is found, will then attempt to open it as a corefile.
4286 * Changes in ARM configurations.
4288 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4289 configuration is fully multi-arch.
4291 * New native configurations
4293 ARM NetBSD arm*-*-netbsd*
4294 x86 OpenBSD i[3456]86-*-openbsd*
4295 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4296 Sparc64 running FreeBSD sparc64-*-freebsd*
4300 Sanyo XStormy16 xstormy16-elf
4302 * OBSOLETE configurations and files
4304 Configurations that have been declared obsolete in this release have
4305 been commented out. Unless there is activity to revive these
4306 configurations, the next release of GDB will have their sources
4307 permanently REMOVED.
4309 AMD 29k family via UDI a29k-amd-udi, udi29k
4310 A29K VxWorks a29k-*-vxworks
4311 AMD 29000 embedded, using EBMON a29k-none-none
4312 AMD 29000 embedded with COFF a29k-none-coff
4313 AMD 29000 embedded with a.out a29k-none-aout
4315 testsuite/gdb.hp/gdb.threads-hp/ directory
4317 * REMOVED configurations and files
4319 TI TMS320C80 tic80-*-*
4321 PowerPC Solaris powerpcle-*-solaris*
4322 PowerPC Windows NT powerpcle-*-cygwin32
4323 PowerPC Netware powerpc-*-netware*
4324 Harris/CXUX m88k m88*-harris-cxux*
4325 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4326 ns32k-utek-sysv* ns32k-utek-*
4327 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4328 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4329 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4330 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4331 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4333 * Changes to command line processing
4335 The new `--args' feature can be used to specify command-line arguments
4336 for the inferior from gdb's command line.
4338 * Changes to key bindings
4340 There is a new `operate-and-get-next' function bound to `C-o'.
4342 *** Changes in GDB 5.1.1
4344 Fix compile problem on DJGPP.
4346 Fix a problem with floating-point registers on the i386 being
4349 Fix to stop GDB crashing on .debug_str debug info.
4351 Numerous documentation fixes.
4353 Numerous testsuite fixes.
4355 *** Changes in GDB 5.1:
4357 * New native configurations
4359 Alpha FreeBSD alpha*-*-freebsd*
4360 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4361 MIPS GNU/Linux mips*-*-linux*
4362 MIPS SGI Irix 6.x mips*-sgi-irix6*
4363 ia64 AIX ia64-*-aix*
4364 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4368 Motorola 68HC11 and 68HC12 m68hc11-elf
4370 UltraSparc running GNU/Linux sparc64-*-linux*
4372 * OBSOLETE configurations and files
4374 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4375 Harris/CXUX m88k m88*-harris-cxux*
4376 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4377 ns32k-utek-sysv* ns32k-utek-*
4378 TI TMS320C80 tic80-*-*
4380 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4381 PowerPC Solaris powerpcle-*-solaris*
4382 PowerPC Windows NT powerpcle-*-cygwin32
4383 PowerPC Netware powerpc-*-netware*
4384 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4385 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4386 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4387 Apple Macintosh (MPW) host N/A
4389 stuff.c (Program to stuff files into a specially prepared space in kdb)
4390 kdb-start.c (Main loop for the standalone kernel debugger)
4392 Configurations that have been declared obsolete in this release have
4393 been commented out. Unless there is activity to revive these
4394 configurations, the next release of GDB will have their sources
4395 permanently REMOVED.
4397 * REMOVED configurations and files
4399 Altos 3068 m68*-altos-*
4400 Convex c1-*-*, c2-*-*
4402 ARM RISCix arm-*-* (as host)
4406 * GDB has been converted to ISO C.
4408 GDB's source code has been converted to ISO C. In particular, the
4409 sources are fully protoized, and rely on standard headers being
4414 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4416 * The MI enabled by default.
4418 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4419 revised and enabled by default. Packages which use GDB as a debugging
4420 engine behind a UI or another front end are encouraged to switch to
4421 using the GDB/MI interface, instead of the old annotations interface
4422 which is now deprecated.
4424 * Support for debugging Pascal programs.
4426 GDB now includes support for debugging Pascal programs. The following
4427 main features are supported:
4429 - Pascal-specific data types such as sets;
4431 - automatic recognition of Pascal sources based on file-name
4434 - Pascal-style display of data types, variables, and functions;
4436 - a Pascal expression parser.
4438 However, some important features are not yet supported.
4440 - Pascal string operations are not supported at all;
4442 - there are some problems with boolean types;
4444 - Pascal type hexadecimal constants are not supported
4445 because they conflict with the internal variables format;
4447 - support for Pascal objects and classes is not full yet;
4449 - unlike Pascal, GDB is case-sensitive for symbol names.
4451 * Changes in completion.
4453 Commands such as `shell', `run' and `set args', which pass arguments
4454 to inferior programs, now complete on file names, similar to what
4455 users expect at the shell prompt.
4457 Commands which accept locations, such as `disassemble', `print',
4458 `breakpoint', `until', etc. now complete on filenames as well as
4459 program symbols. Thus, if you type "break foob TAB", and the source
4460 files linked into the programs include `foobar.c', that file name will
4461 be one of the candidates for completion. However, file names are not
4462 considered for completion after you typed a colon that delimits a file
4463 name from a name of a function in that file, as in "break foo.c:bar".
4465 `set demangle-style' completes on available demangling styles.
4467 * New platform-independent commands:
4469 It is now possible to define a post-hook for a command as well as a
4470 hook that runs before the command. For more details, see the
4471 documentation of `hookpost' in the GDB manual.
4473 * Changes in GNU/Linux native debugging.
4475 Support for debugging multi-threaded programs has been completely
4476 revised for all platforms except m68k and sparc. You can now debug as
4477 many threads as your system allows you to have.
4479 Attach/detach is supported for multi-threaded programs.
4481 Support for SSE registers was added for x86. This doesn't work for
4482 multi-threaded programs though.
4484 * Changes in MIPS configurations.
4486 Multi-arch support is enabled for all MIPS configurations.
4488 GDB can now be built as native debugger on SGI Irix 6.x systems for
4489 debugging n32 executables. (Debugging 64-bit executables is not yet
4492 * Unified support for hardware watchpoints in all x86 configurations.
4494 Most (if not all) native x86 configurations support hardware-assisted
4495 breakpoints and watchpoints in a unified manner. This support
4496 implements debug register sharing between watchpoints, which allows to
4497 put a virtually infinite number of watchpoints on the same address,
4498 and also supports watching regions up to 16 bytes with several debug
4501 The new maintenance command `maintenance show-debug-regs' toggles
4502 debugging print-outs in functions that insert, remove, and test
4503 watchpoints and hardware breakpoints.
4505 * Changes in the DJGPP native configuration.
4507 New command ``info dos sysinfo'' displays assorted information about
4508 the CPU, OS, memory, and DPMI server.
4510 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4511 display information about segment descriptors stored in GDT, LDT, and
4514 New commands ``info dos pde'' and ``info dos pte'' display entries
4515 from Page Directory and Page Tables (for now works with CWSDPMI only).
4516 New command ``info dos address-pte'' displays the Page Table entry for
4517 a given linear address.
4519 GDB can now pass command lines longer than 126 characters to the
4520 program being debugged (requires an update to the libdbg.a library
4521 which is part of the DJGPP development kit).
4523 DWARF2 debug info is now supported.
4525 It is now possible to `step' and `next' through calls to `longjmp'.
4527 * Changes in documentation.
4529 All GDB documentation was converted to GFDL, the GNU Free
4530 Documentation License.
4532 Tracepoints-related commands are now fully documented in the GDB
4535 TUI, the Text-mode User Interface, is now documented in the manual.
4537 Tracepoints-related commands are now fully documented in the GDB
4540 The "GDB Internals" manual now has an index. It also includes
4541 documentation of `ui_out' functions, GDB coding standards, x86
4542 hardware watchpoints, and memory region attributes.
4544 * GDB's version number moved to ``version.in''
4546 The Makefile variable VERSION has been replaced by the file
4547 ``version.in''. People creating GDB distributions should update the
4548 contents of this file.
4552 GUD support is now a standard part of the EMACS distribution.
4554 *** Changes in GDB 5.0:
4556 * Improved support for debugging FP programs on x86 targets
4558 Unified and much-improved support for debugging floating-point
4559 programs on all x86 targets. In particular, ``info float'' now
4560 displays the FP registers in the same format on all x86 targets, with
4561 greater level of detail.
4563 * Improvements and bugfixes in hardware-assisted watchpoints
4565 It is now possible to watch array elements, struct members, and
4566 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4567 on x86 targets no longer erroneously trigger when the address is
4570 * Improvements in the native DJGPP version of GDB
4572 The distribution now includes all the scripts and auxiliary files
4573 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4574 machines ``out of the box''.
4576 The DJGPP version can now debug programs that use signals. It is
4577 possible to catch signals that happened in the debuggee, deliver
4578 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4579 would kill the program being debugged.) Programs that hook hardware
4580 interrupts (keyboard, timer, etc.) can also be debugged.
4582 It is now possible to debug DJGPP programs that redirect their
4583 standard handles or switch them to raw (as opposed to cooked) mode, or
4584 even close them. The command ``run < foo > bar'' works as expected,
4585 and ``info terminal'' reports useful information about the debuggee's
4586 terminal, including raw/cooked mode, redirection, etc.
4588 The DJGPP version now uses termios functions for console I/O, which
4589 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4592 DOS-style file names with drive letters are now fully supported by
4595 It is now possible to debug DJGPP programs that switch their working
4596 directory. It is also possible to rerun the debuggee any number of
4597 times without restarting GDB; thus, you can use the same setup,
4598 breakpoints, etc. for many debugging sessions.
4600 * New native configurations
4602 ARM GNU/Linux arm*-*-linux*
4603 PowerPC GNU/Linux powerpc-*-linux*
4607 Motorola MCore mcore-*-*
4608 x86 VxWorks i[3456]86-*-vxworks*
4609 PowerPC VxWorks powerpc-*-vxworks*
4610 TI TMS320C80 tic80-*-*
4612 * OBSOLETE configurations
4614 Altos 3068 m68*-altos-*
4615 Convex c1-*-*, c2-*-*
4617 ARM RISCix arm-*-* (as host)
4620 Configurations that have been declared obsolete will be commented out,
4621 but the code will be left in place. If there is no activity to revive
4622 these configurations before the next release of GDB, the sources will
4623 be permanently REMOVED.
4625 * Gould support removed
4627 Support for the Gould PowerNode and NP1 has been removed.
4629 * New features for SVR4
4631 On SVR4 native platforms (such as Solaris), if you attach to a process
4632 without first loading a symbol file, GDB will now attempt to locate and
4633 load symbols from the running process's executable file.
4635 * Many C++ enhancements
4637 C++ support has been greatly improved. Overload resolution now works properly
4638 in almost all cases. RTTI support is on the way.
4640 * Remote targets can connect to a sub-program
4642 A popen(3) style serial-device has been added. This device starts a
4643 sub-process (such as a stand-alone simulator) and then communicates
4644 with that. The sub-program to run is specified using the syntax
4645 ``|<program> <args>'' vis:
4647 (gdb) set remotedebug 1
4648 (gdb) target extended-remote |mn10300-elf-sim program-args
4650 * MIPS 64 remote protocol
4652 A long standing bug in the mips64 remote protocol where by GDB
4653 expected certain 32 bit registers (ex SR) to be transfered as 32
4654 instead of 64 bits has been fixed.
4656 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4657 added to provide backward compatibility with older versions of GDB.
4659 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4661 The command ``set remotebinarydownload'' command has been replaced by
4662 ``set remote X-packet''. Other commands in ``set remote'' family
4663 include ``set remote P-packet''.
4665 * Breakpoint commands accept ranges.
4667 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4668 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4669 ``tracepoint passcount'' also accepts a range of tracepoints.
4671 * ``apropos'' command added.
4673 The ``apropos'' command searches through command names and
4674 documentation strings, printing out matches, making it much easier to
4675 try to find a command that does what you are looking for.
4679 A new machine oriented interface (MI) has been added to GDB. This
4680 interface is designed for debug environments running GDB as a separate
4681 process. This is part of the long term libGDB project. See the
4682 "GDB/MI" chapter of the GDB manual for further information. It can be
4683 enabled by configuring with:
4685 .../configure --enable-gdbmi
4687 *** Changes in GDB-4.18:
4689 * New native configurations
4691 HP-UX 10.20 hppa*-*-hpux10.20
4692 HP-UX 11.x hppa*-*-hpux11.0*
4693 M68K GNU/Linux m68*-*-linux*
4697 Fujitsu FR30 fr30-*-elf*
4698 Intel StrongARM strongarm-*-*
4699 Mitsubishi D30V d30v-*-*
4701 * OBSOLETE configurations
4703 Gould PowerNode, NP1 np1-*-*, pn-*-*
4705 Configurations that have been declared obsolete will be commented out,
4706 but the code will be left in place. If there is no activity to revive
4707 these configurations before the next release of GDB, the sources will
4708 be permanently REMOVED.
4712 As a compatibility experiment, GDB's source files buildsym.h and
4713 buildsym.c have been converted to pure standard C, no longer
4714 containing any K&R compatibility code. We believe that all systems in
4715 use today either come with a standard C compiler, or have a GCC port
4716 available. If this is not true, please report the affected
4717 configuration to bug-gdb@gnu.org immediately. See the README file for
4718 information about getting a standard C compiler if you don't have one
4723 GDB now uses readline 2.2.
4725 * set extension-language
4727 You can now control the mapping between filename extensions and source
4728 languages by using the `set extension-language' command. For instance,
4729 you can ask GDB to treat .c files as C++ by saying
4730 set extension-language .c c++
4731 The command `info extensions' lists all of the recognized extensions
4732 and their associated languages.
4734 * Setting processor type for PowerPC and RS/6000
4736 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4737 you can use the `set processor' command to specify what variant of the
4738 PowerPC family you are debugging. The command
4742 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4743 following PowerPC and RS6000 variants:
4745 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4746 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4748 403GC IBM PowerPC 403GC
4749 505 Motorola PowerPC 505
4750 860 Motorola PowerPC 860 or 850
4751 601 Motorola PowerPC 601
4752 602 Motorola PowerPC 602
4753 603 Motorola/IBM PowerPC 603 or 603e
4754 604 Motorola PowerPC 604 or 604e
4755 750 Motorola/IBM PowerPC 750 or 750
4757 At the moment, this command just tells GDB what to name the
4758 special-purpose processor registers. Since almost all the affected
4759 registers are inaccessible to user-level programs, this command is
4760 only useful for remote debugging in its present form.
4764 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4765 more extensive support for HP-UX. Added features include shared
4766 library support, kernel threads and hardware watchpoints for 11.00,
4767 support for HP's ANSI C and C++ compilers, and a compatibility mode
4768 for xdb and dbx commands.
4772 HP's donation includes the new concept of catchpoints, which is a
4773 generalization of the old catch command. On HP-UX, it is now possible
4774 to catch exec, fork, and vfork, as well as library loading.
4776 This means that the existing catch command has changed; its first
4777 argument now specifies the type of catch to be set up. See the
4778 output of "help catch" for a list of catchpoint types.
4780 * Debugging across forks
4782 On HP-UX, you can choose which process to debug when a fork() happens
4787 HP has donated a curses-based terminal user interface (TUI). To get
4788 it, build with --enable-tui. Although this can be enabled for any
4789 configuration, at present it only works for native HP debugging.
4791 * GDB remote protocol additions
4793 A new protocol packet 'X' that writes binary data is now available.
4794 Default behavior is to try 'X', then drop back to 'M' if the stub
4795 fails to respond. The settable variable `remotebinarydownload'
4796 allows explicit control over the use of 'X'.
4798 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4799 full 64-bit address. The command
4801 set remoteaddresssize 32
4803 can be used to revert to the old behaviour. For existing remote stubs
4804 the change should not be noticed, as the additional address information
4807 In order to assist in debugging stubs, you may use the maintenance
4808 command `packet' to send any text string to the stub. For instance,
4810 maint packet heythere
4812 sends the packet "$heythere#<checksum>". Note that it is very easy to
4813 disrupt a debugging session by sending the wrong packet at the wrong
4816 The compare-sections command allows you to compare section data on the
4817 target to what is in the executable file without uploading or
4818 downloading, by comparing CRC checksums.
4820 * Tracing can collect general expressions
4822 You may now collect general expressions at tracepoints. This requires
4823 further additions to the target-side stub; see tracepoint.c and
4824 doc/agentexpr.texi for further details.
4826 * mask-address variable for Mips
4828 For Mips targets, you may control the zeroing of the upper 32 bits of
4829 a 64-bit address by entering `set mask-address on'. This is mainly
4830 of interest to users of embedded R4xxx and R5xxx processors.
4832 * Higher serial baud rates
4834 GDB's serial code now allows you to specify baud rates 57600, 115200,
4835 230400, and 460800 baud. (Note that your host system may not be able
4836 to achieve all of these rates.)
4840 The i960 configuration now includes an initial implementation of a
4841 builtin simulator, contributed by Jim Wilson.
4844 *** Changes in GDB-4.17:
4846 * New native configurations
4848 Alpha GNU/Linux alpha*-*-linux*
4849 Unixware 2.x i[3456]86-unixware2*
4850 Irix 6.x mips*-sgi-irix6*
4851 PowerPC GNU/Linux powerpc-*-linux*
4852 PowerPC Solaris powerpcle-*-solaris*
4853 Sparc GNU/Linux sparc-*-linux*
4854 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4858 Argonaut Risc Chip (ARC) arc-*-*
4859 Hitachi H8/300S h8300*-*-*
4860 Matsushita MN10200 w/simulator mn10200-*-*
4861 Matsushita MN10300 w/simulator mn10300-*-*
4862 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4863 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4864 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4865 Mitsubishi D10V w/simulator d10v-*-*
4866 Mitsubishi M32R/D w/simulator m32r-*-elf*
4867 Tsqware Sparclet sparclet-*-*
4868 NEC V850 w/simulator v850-*-*
4870 * New debugging protocols
4872 ARM with RDI protocol arm*-*-*
4873 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4874 DDB and LSI variants of PMON protocol mips*-*-*
4875 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4876 PowerPC with SDS protocol powerpc{,le}-*-eabi
4877 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4881 All configurations can now understand and use the DWARF 2 debugging
4882 format. The choice is automatic, if the symbol file contains DWARF 2
4887 GDB now includes basic Java language support. This support is
4888 only useful with Java compilers that produce native machine code.
4890 * solib-absolute-prefix and solib-search-path
4892 For SunOS and SVR4 shared libraries, you may now set the prefix for
4893 loading absolute shared library symbol files, and the search path for
4894 locating non-absolute shared library symbol files.
4896 * Live range splitting
4898 GDB can now effectively debug code for which GCC has performed live
4899 range splitting as part of its optimization. See gdb/doc/LRS for
4900 more details on the expected format of the stabs information.
4904 GDB's support for the GNU Hurd, including thread debugging, has been
4905 updated to work with current versions of the Hurd.
4909 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4910 instruction set. ARM GDB automatically detects when Thumb
4911 instructions are in use, and adjusts disassembly and backtracing
4916 GDB's MIPS target configurations now handle the MIP16 16-bit
4921 GDB now includes support for overlays; if an executable has been
4922 linked such that multiple sections are based at the same address, GDB
4923 will decide which section to use for symbolic info. You can choose to
4924 control the decision manually, using overlay commands, or implement
4925 additional target-side support and use "overlay load-target" to bring
4926 in the overlay mapping. Do "help overlay" for more detail.
4930 The command "info symbol <address>" displays information about
4931 the symbol at the specified address.
4935 The standard remote protocol now includes an extension that allows
4936 asynchronous collection and display of trace data. This requires
4937 extensive support in the target-side debugging stub. Tracing mode
4938 includes a new interaction mode in GDB and new commands: see the
4939 file tracepoint.c for more details.
4943 Configurations for embedded MIPS now include a simulator contributed
4944 by Cygnus Solutions. The simulator supports the instruction sets
4945 of most MIPS variants.
4949 Sparc configurations may now include the ERC32 simulator contributed
4950 by the European Space Agency. The simulator is not built into
4951 Sparc targets by default; configure with --enable-sim to include it.
4955 For target configurations that may include multiple variants of a
4956 basic architecture (such as MIPS and SH), you may now set the
4957 architecture explicitly. "set arch" sets, "info arch" lists
4958 the possible architectures.
4960 *** Changes in GDB-4.16:
4962 * New native configurations
4964 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4965 M68K NetBSD m68k-*-netbsd*
4966 PowerPC AIX 4.x powerpc-*-aix*
4967 PowerPC MacOS powerpc-*-macos*
4968 PowerPC Windows NT powerpcle-*-cygwin32
4969 RS/6000 AIX 4.x rs6000-*-aix4*
4973 ARM with RDP protocol arm-*-*
4974 I960 with MON960 i960-*-coff
4975 MIPS VxWorks mips*-*-vxworks*
4976 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4977 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4979 Matra Sparclet sparclet-*-*
4983 The powerpc-eabi configuration now includes the PSIM simulator,
4984 contributed by Andrew Cagney, with assistance from Mike Meissner.
4985 PSIM is a very elaborate model of the PowerPC, including not only
4986 basic instruction set execution, but also details of execution unit
4987 performance and I/O hardware. See sim/ppc/README for more details.
4991 GDB now works with Solaris 2.5.
4993 * Windows 95/NT native
4995 GDB will now work as a native debugger on Windows 95 and Windows NT.
4996 To build it from source, you must use the "gnu-win32" environment,
4997 which uses a DLL to emulate enough of Unix to run the GNU tools.
4998 Further information, binaries, and sources are available at
4999 ftp.cygnus.com, under pub/gnu-win32.
5001 * dont-repeat command
5003 If a user-defined command includes the command `dont-repeat', then the
5004 command will not be repeated if the user just types return. This is
5005 useful if the command is time-consuming to run, so that accidental
5006 extra keystrokes don't run the same command many times.
5008 * Send break instead of ^C
5010 The standard remote protocol now includes an option to send a break
5011 rather than a ^C to the target in order to interrupt it. By default,
5012 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5014 * Remote protocol timeout
5016 The standard remote protocol includes a new variable `remotetimeout'
5017 that allows you to set the number of seconds before GDB gives up trying
5018 to read from the target. The default value is 2.
5020 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5022 By default GDB will automatically keep track of objects as they are
5023 loaded and unloaded by the dynamic linker. By using the command `set
5024 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5025 when shared library events occur, thus allowing you to set breakpoints
5026 in shared libraries which are explicitly loaded by the inferior.
5028 Note this feature does not work on hpux8. On hpux9 you must link
5029 /usr/lib/end.o into your program. This feature should work
5030 automatically on hpux10.
5032 * Irix 5.x hardware watchpoint support
5034 Irix 5 configurations now support the use of hardware watchpoints.
5036 * Mips protocol "SYN garbage limit"
5038 When debugging a Mips target using the `target mips' protocol, you
5039 may set the number of characters that GDB will ignore by setting
5040 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5041 every character. The default value is 1050.
5043 * Recording and replaying remote debug sessions
5045 If you set `remotelogfile' to the name of a file, gdb will write to it
5046 a recording of a remote debug session. This recording may then be
5047 replayed back to gdb using "gdbreplay". See gdbserver/README for
5048 details. This is useful when you have a problem with GDB while doing
5049 remote debugging; you can make a recording of the session and send it
5050 to someone else, who can then recreate the problem.
5052 * Speedups for remote debugging
5054 GDB includes speedups for downloading and stepping MIPS systems using
5055 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5056 and more efficient S-record downloading.
5058 * Memory use reductions and statistics collection
5060 GDB now uses less memory and reports statistics about memory usage.
5061 Try the `maint print statistics' command, for example.
5063 *** Changes in GDB-4.15:
5065 * Psymtabs for XCOFF
5067 The symbol reader for AIX GDB now uses partial symbol tables. This
5068 can greatly improve startup time, especially for large executables.
5070 * Remote targets use caching
5072 Remote targets now use a data cache to speed up communication with the
5073 remote side. The data cache could lead to incorrect results because
5074 it doesn't know about volatile variables, thus making it impossible to
5075 debug targets which use memory mapped I/O devices. `set remotecache
5076 off' turns the the data cache off.
5078 * Remote targets may have threads
5080 The standard remote protocol now includes support for multiple threads
5081 in the target system, using new protocol commands 'H' and 'T'. See
5082 gdb/remote.c for details.
5086 If GDB is configured with `--enable-netrom', then it will include
5087 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5088 acts as though it is a bank of ROM on the target board, but you can
5089 write into it over the network. GDB's support consists only of
5090 support for fast loading into the emulated ROM; to debug, you must use
5091 another protocol, such as standard remote protocol. The usual
5092 sequence is something like
5094 target nrom <netrom-hostname>
5096 target remote <netrom-hostname>:1235
5100 GDB now includes support for the Apple Macintosh, as a host only. It
5101 may be run as either an MPW tool or as a standalone application, and
5102 it can debug through the serial port. All the usual GDB commands are
5103 available, but to the target command, you must supply "serial" as the
5104 device type instead of "/dev/ttyXX". See mpw-README in the main
5105 directory for more information on how to build. The MPW configuration
5106 scripts */mpw-config.in support only a few targets, and only the
5107 mips-idt-ecoff target has been tested.
5111 GDB configuration now uses autoconf. This is not user-visible,
5112 but does simplify configuration and building.
5116 GDB now supports hpux10.
5118 *** Changes in GDB-4.14:
5120 * New native configurations
5122 x86 FreeBSD i[345]86-*-freebsd
5123 x86 NetBSD i[345]86-*-netbsd
5124 NS32k NetBSD ns32k-*-netbsd
5125 Sparc NetBSD sparc-*-netbsd
5129 A29K VxWorks a29k-*-vxworks
5130 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5131 CPU32 EST-300 emulator m68*-*-est*
5132 PowerPC ELF powerpc-*-elf
5135 * Alpha OSF/1 support for procfs
5137 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5138 possible to attach to running processes. As the mounting of the /proc
5139 filesystem is optional on the Alpha, GDB automatically determines
5140 the availability of /proc during startup. This can lead to problems
5141 if /proc is unmounted after GDB has been started.
5143 * Arguments to user-defined commands
5145 User commands may accept up to 10 arguments separated by whitespace.
5146 Arguments are accessed within the user command via $arg0..$arg9. A
5149 print $arg0 + $arg1 + $arg2
5151 To execute the command use:
5154 Defines the command "adder" which prints the sum of its three arguments.
5155 Note the arguments are text substitutions, so they may reference variables,
5156 use complex expressions, or even perform inferior function calls.
5158 * New `if' and `while' commands
5160 This makes it possible to write more sophisticated user-defined
5161 commands. Both commands take a single argument, which is the
5162 expression to evaluate, and must be followed by the commands to
5163 execute, one per line, if the expression is nonzero, the list being
5164 terminated by the word `end'. The `if' command list may include an
5165 `else' word, which causes the following commands to be executed only
5166 if the expression is zero.
5168 * Fortran source language mode
5170 GDB now includes partial support for Fortran 77. It will recognize
5171 Fortran programs and can evaluate a subset of Fortran expressions, but
5172 variables and functions may not be handled correctly. GDB will work
5173 with G77, but does not yet know much about symbols emitted by other
5176 * Better HPUX support
5178 Most debugging facilities now work on dynamic executables for HPPAs
5179 running hpux9 or later. You can attach to running dynamically linked
5180 processes, but by default the dynamic libraries will be read-only, so
5181 for instance you won't be able to put breakpoints in them. To change
5182 that behavior do the following before running the program:
5188 This will cause the libraries to be mapped private and read-write.
5189 To revert to the normal behavior, do this:
5195 You cannot set breakpoints or examine data in the library until after
5196 the library is loaded if the function/data symbols do not have
5199 GDB can now also read debug symbols produced by the HP C compiler on
5200 HPPAs (sorry, no C++, Fortran or 68k support).
5202 * Target byte order now dynamically selectable
5204 You can choose which byte order to use with a target system, via the
5205 commands "set endian big" and "set endian little", and you can see the
5206 current setting by using "show endian". You can also give the command
5207 "set endian auto", in which case GDB will use the byte order
5208 associated with the executable. Currently, only embedded MIPS
5209 configurations support dynamic selection of target byte order.
5211 * New DOS host serial code
5213 This version uses DPMI interrupts to handle buffered I/O, so you
5214 no longer need to run asynctsr when debugging boards connected to
5217 *** Changes in GDB-4.13:
5219 * New "complete" command
5221 This lists all the possible completions for the rest of the line, if it
5222 were to be given as a command itself. This is intended for use by emacs.
5224 * Trailing space optional in prompt
5226 "set prompt" no longer adds a space for you after the prompt you set. This
5227 allows you to set a prompt which ends in a space or one that does not.
5229 * Breakpoint hit counts
5231 "info break" now displays a count of the number of times the breakpoint
5232 has been hit. This is especially useful in conjunction with "ignore"; you
5233 can ignore a large number of breakpoint hits, look at the breakpoint info
5234 to see how many times the breakpoint was hit, then run again, ignoring one
5235 less than that number, and this will get you quickly to the last hit of
5238 * Ability to stop printing at NULL character
5240 "set print null-stop" will cause GDB to stop printing the characters of
5241 an array when the first NULL is encountered. This is useful when large
5242 arrays actually contain only short strings.
5244 * Shared library breakpoints
5246 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5247 breakpoints in shared libraries before the executable is run.
5249 * Hardware watchpoints
5251 There is a new hardware breakpoint for the watch command for sparclite
5252 targets. See gdb/sparclite/hw_breakpoint.note.
5254 Hardware watchpoints are also now supported under GNU/Linux.
5258 Annotations have been added. These are for use with graphical interfaces,
5259 and are still experimental. Currently only gdba.el uses these.
5261 * Improved Irix 5 support
5263 GDB now works properly with Irix 5.2.
5265 * Improved HPPA support
5267 GDB now works properly with the latest GCC and GAS.
5269 * New native configurations
5271 Sequent PTX4 i[34]86-sequent-ptx4
5272 HPPA running OSF/1 hppa*-*-osf*
5273 Atari TT running SVR4 m68*-*-sysv4*
5274 RS/6000 LynxOS rs6000-*-lynxos*
5278 OS/9000 i[34]86-*-os9k
5279 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5282 * Hitachi SH7000 and E7000-PC ICE support
5284 There is now support for communicating with the Hitachi E7000-PC ICE.
5285 This is available automatically when GDB is configured for the SH.
5289 As usual, a variety of small fixes and improvements, both generic
5290 and configuration-specific. See the ChangeLog for more detail.
5292 *** Changes in GDB-4.12:
5294 * Irix 5 is now supported
5298 GDB-4.12 on the HPPA has a number of changes which make it unable
5299 to debug the output from the currently released versions of GCC and
5300 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5301 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5302 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5305 *** Changes in GDB-4.11:
5307 * User visible changes:
5311 The "set remotedebug" option is now consistent between the mips remote
5312 target, remote targets using the gdb-specific protocol, UDI (AMD's
5313 debug protocol for the 29k) and the 88k bug monitor. It is now an
5314 integer specifying a debug level (normally 0 or 1, but 2 means more
5315 debugging info for the mips target).
5317 * DEC Alpha native support
5319 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5320 debug info, but GDB works fairly well with the DEC compiler and should
5321 work with a future GCC release. See the README file for a few
5322 Alpha-specific notes.
5324 * Preliminary thread implementation
5326 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5328 * LynxOS native and target support for 386
5330 This release has been hosted on LynxOS 2.2, and also can be configured
5331 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5334 * Improvements in C++ mangling/demangling.
5336 This release has much better g++ debugging, specifically in name
5337 mangling/demangling, virtual function calls, print virtual table,
5338 call methods, ...etc.
5340 *** Changes in GDB-4.10:
5342 * User visible changes:
5344 Remote debugging using the GDB-specific (`target remote') protocol now
5345 supports the `load' command. This is only useful if you have some
5346 other way of getting the stub to the target system, and you can put it
5347 somewhere in memory where it won't get clobbered by the download.
5349 Filename completion now works.
5351 When run under emacs mode, the "info line" command now causes the
5352 arrow to point to the line specified. Also, "info line" prints
5353 addresses in symbolic form (as well as hex).
5355 All vxworks based targets now support a user settable option, called
5356 vxworks-timeout. This option represents the number of seconds gdb
5357 should wait for responses to rpc's. You might want to use this if
5358 your vxworks target is, perhaps, a slow software simulator or happens
5359 to be on the far side of a thin network line.
5363 This release contains support for using a DEC alpha as a GDB host for
5364 cross debugging. Native alpha debugging is not supported yet.
5367 *** Changes in GDB-4.9:
5371 This is the first GDB release which is accompanied by a matching testsuite.
5372 The testsuite requires installation of dejagnu, which should be available
5373 via ftp from most sites that carry GNU software.
5377 'Cfront' style demangling has had its name changed to 'ARM' style, to
5378 emphasize that it was written from the specifications in the C++ Annotated
5379 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5380 disclaimers, it still generated too much confusion with users attempting to
5381 use gdb with AT&T cfront.
5385 GDB now uses a standard remote interface to a simulator library.
5386 So far, the library contains simulators for the Zilog Z8001/2, the
5387 Hitachi H8/300, H8/500 and Super-H.
5389 * New targets supported
5391 H8/300 simulator h8300-hitachi-hms or h8300hms
5392 H8/500 simulator h8500-hitachi-hms or h8500hms
5393 SH simulator sh-hitachi-hms or sh
5394 Z8000 simulator z8k-zilog-none or z8ksim
5395 IDT MIPS board over serial line mips-idt-ecoff
5397 Cross-debugging to GO32 targets is supported. It requires a custom
5398 version of the i386-stub.c module which is integrated with the
5399 GO32 memory extender.
5401 * New remote protocols
5403 MIPS remote debugging protocol.
5405 * New source languages supported
5407 This version includes preliminary support for Chill, a Pascal like language
5408 used by telecommunications companies. Chill support is also being integrated
5409 into the GNU compiler, but we don't know when it will be publically available.
5412 *** Changes in GDB-4.8:
5414 * HP Precision Architecture supported
5416 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5417 version of this support was available as a set of patches from the
5418 University of Utah. GDB does not support debugging of programs
5419 compiled with the HP compiler, because HP will not document their file
5420 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5421 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5423 Many problems in the preliminary version have been fixed.
5425 * Faster and better demangling
5427 We have improved template demangling and fixed numerous bugs in the GNU style
5428 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5429 character types (wchar_t) are now supported. Demangling of each symbol is now
5430 only done once, and is cached when the symbol table for a file is read in.
5431 This results in a small increase in memory usage for C programs, a moderate
5432 increase in memory usage for C++ programs, and a fantastic speedup in
5435 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5436 from the specifications in the Annotated Reference Manual, which AT&T's
5437 compiler does not actually implement.
5439 * G++ multiple inheritance compiler problem
5441 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5442 inheritance lattices was reworked to properly discover ambiguities. We
5443 recently found an example which causes this new algorithm to fail in a
5444 very subtle way, producing bad debug information for those classes.
5445 The file 'gcc.patch' (in this directory) can be applied to gcc to
5446 circumvent the problem. A future GCC release will contain a complete
5449 The previous G++ debug info problem (mentioned below for the gdb-4.7
5450 release) is fixed in gcc version 2.3.2.
5452 * Improved configure script
5454 The `configure' script will now attempt to guess your system type if
5455 you don't supply a host system type. The old scheme of supplying a
5456 host system triplet is preferable over using this. All the magic is
5457 done in the new `config.guess' script. Examine it for details.
5459 We have also brought our configure script much more in line with the FSF's
5460 version. It now supports the --with-xxx options. In particular,
5461 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5462 The resulting GDB will not be able to read arbitrary object file formats --
5463 only the format ``expected'' to be used on the configured target system.
5464 We hope to make this the default in a future release.
5466 * Documentation improvements
5468 There's new internal documentation on how to modify GDB, and how to
5469 produce clean changes to the code. We implore people to read it
5470 before submitting changes.
5472 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5473 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5474 `info' files are also provided. To build `info' files from scratch,
5475 you will need the latest `makeinfo' release, which will be available in
5476 a future texinfo-X.Y release.
5478 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5479 We're not sure exactly which versions have this problem, but it has
5480 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5481 or better. If that isn't possible, there is a patch in
5482 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5483 around this problem.
5487 GDB now supports array constants that can be used in expressions typed in by
5488 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5489 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5492 The new directory `gdb/sparclite' contains a program that demonstrates
5493 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5495 * New native hosts supported
5497 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5498 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5500 * New targets supported
5502 AMD 29k family via UDI a29k-amd-udi or udi29k
5504 * New file formats supported
5506 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5507 HPUX core files, and SCO 3.2v2 core files.
5511 Attaching to processes now works again; thanks for the many bug reports.
5513 We have also stomped on a bunch of core dumps caused by
5514 printf_filtered("%s") problems.
5516 We eliminated a copyright problem on the rpc and ptrace header files
5517 for VxWorks, which was discovered at the last minute during the 4.7
5518 release. You should now be able to build a VxWorks GDB.
5520 You can now interrupt gdb while an attached process is running. This
5521 will cause the attached process to stop, and give control back to GDB.
5523 We fixed problems caused by using too many file descriptors
5524 for reading symbols from object files and libraries. This was
5525 especially a problem for programs that used many (~100) shared
5528 The `step' command now only enters a subroutine if there is line number
5529 information for the subroutine. Otherwise it acts like the `next'
5530 command. Previously, `step' would enter subroutines if there was
5531 any debugging information about the routine. This avoids problems
5532 when using `cc -g1' on MIPS machines.
5534 * Internal improvements
5536 GDB's internal interfaces have been improved to make it easier to support
5537 debugging of multiple languages in the future.
5539 GDB now uses a common structure for symbol information internally.
5540 Minimal symbols (derived from linkage symbols in object files), partial
5541 symbols (from a quick scan of debug information), and full symbols
5542 contain a common subset of information, making it easier to write
5543 shared code that handles any of them.
5545 * New command line options
5547 We now accept --silent as an alias for --quiet.
5551 The memory-mapped-malloc library is now licensed under the GNU Library
5552 General Public License.
5554 *** Changes in GDB-4.7:
5556 * Host/native/target split
5558 GDB has had some major internal surgery to untangle the support for
5559 hosts and remote targets. Now, when you configure GDB for a remote
5560 target, it will no longer load in all of the support for debugging
5561 local programs on the host. When fully completed and tested, this will
5562 ensure that arbitrary host/target combinations are possible.
5564 The primary conceptual shift is to separate the non-portable code in
5565 GDB into three categories. Host specific code is required any time GDB
5566 is compiled on that host, regardless of the target. Target specific
5567 code relates to the peculiarities of the target, but can be compiled on
5568 any host. Native specific code is everything else: it can only be
5569 built when the host and target are the same system. Child process
5570 handling and core file support are two common `native' examples.
5572 GDB's use of /proc for controlling Unix child processes is now cleaner.
5573 It has been split out into a single module under the `target_ops' vector,
5574 plus two native-dependent functions for each system that uses /proc.
5576 * New hosts supported
5578 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5579 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5580 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5582 * New targets supported
5584 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5585 68030 and CPU32 m68030-*-*, m68332-*-*
5587 * New native hosts supported
5589 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5590 (386bsd is not well tested yet)
5591 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5593 * New file formats supported
5595 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5596 supports reading of `a.out.adobe' object files, which are an a.out
5597 format extended with minimal information about multiple sections.
5601 `show copying' is the same as the old `info copying'.
5602 `show warranty' is the same as `info warrantee'.
5603 These were renamed for consistency. The old commands continue to work.
5605 `info handle' is a new alias for `info signals'.
5607 You can now define pre-command hooks, which attach arbitrary command
5608 scripts to any command. The commands in the hook will be executed
5609 prior to the user's command. You can also create a hook which will be
5610 executed whenever the program stops. See gdb.texinfo.
5614 We now deal with Cfront style name mangling, and can even extract type
5615 info from mangled symbols. GDB can automatically figure out which
5616 symbol mangling style your C++ compiler uses.
5618 Calling of methods and virtual functions has been improved as well.
5622 The crash that occured when debugging Sun Ansi-C compiled binaries is
5623 fixed. This was due to mishandling of the extra N_SO stabs output
5626 We also finally got Ultrix 4.2 running in house, and fixed core file
5627 support, with help from a dozen people on the net.
5629 John M. Farrell discovered that the reason that single-stepping was so
5630 slow on all of the Mips based platforms (primarily SGI and DEC) was
5631 that we were trying to demangle and lookup a symbol used for internal
5632 purposes on every instruction that was being stepped through. Changing
5633 the name of that symbol so that it couldn't be mistaken for a C++
5634 mangled symbol sped things up a great deal.
5636 Rich Pixley sped up symbol lookups in general by getting much smarter
5637 about when C++ symbol mangling is necessary. This should make symbol
5638 completion (TAB on the command line) much faster. It's not as fast as
5639 we'd like, but it's significantly faster than gdb-4.6.
5643 A new user controllable variable 'call_scratch_address' can
5644 specify the location of a scratch area to be used when GDB
5645 calls a function in the target. This is necessary because the
5646 usual method of putting the scratch area on the stack does not work
5647 in systems that have separate instruction and data spaces.
5649 We integrated changes to support the 29k UDI (Universal Debugger
5650 Interface), but discovered at the last minute that we didn't have all
5651 of the appropriate copyright paperwork. We are working with AMD to
5652 resolve this, and hope to have it available soon.
5656 We have sped up the remote serial line protocol, especially for targets
5657 with lots of registers. It now supports a new `expedited status' ('T')
5658 message which can be used in place of the existing 'S' status message.
5659 This allows the remote stub to send only the registers that GDB
5660 needs to make a quick decision about single-stepping or conditional
5661 breakpoints, eliminating the need to fetch the entire register set for
5662 each instruction being stepped through.
5664 The GDB remote serial protocol now implements a write-through cache for
5665 registers, only re-reading the registers if the target has run.
5667 There is also a new remote serial stub for SPARC processors. You can
5668 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5669 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5670 processor with a serial port.
5674 Configure.in files have become much easier to read and modify. A new
5675 `table driven' format makes it more obvious what configurations are
5676 supported, and what files each one uses.
5680 There is a new opcodes library which will eventually contain all of the
5681 disassembly routines and opcode tables. At present, it only contains
5682 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5683 disassembler (binutils/objdump) to share these routines.
5685 The libiberty library is now copylefted under the GNU Library General
5686 Public License. This allows more liberal use, and was done so libg++
5687 can use it. This makes no difference to GDB, since the Library License
5688 grants all the rights from the General Public License.
5692 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5693 reference to the stabs symbol info used by the debugger. It is (as far
5694 as we know) the only published document on this fascinating topic. We
5695 encourage you to read it, compare it to the stabs information on your
5696 system, and send improvements on the document in general (to
5697 bug-gdb@prep.ai.mit.edu).
5699 And, of course, many bugs have been fixed.
5702 *** Changes in GDB-4.6:
5704 * Better support for C++ function names
5706 GDB now accepts as input the "demangled form" of C++ overloaded function
5707 names and member function names, and can do command completion on such names
5708 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5709 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5710 Make use of command completion, it is your friend.
5712 GDB also now accepts a variety of C++ mangled symbol formats. They are
5713 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5714 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5715 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5716 for the list of formats.
5718 * G++ symbol mangling problem
5720 Recent versions of gcc have a bug in how they emit debugging information for
5721 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5722 directory) can be applied to gcc to fix the problem. Alternatively, if you
5723 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5724 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5725 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5728 * New 'maintenance' command
5730 All of the commands related to hacking GDB internals have been moved out of
5731 the main command set, and now live behind the 'maintenance' command. This
5732 can also be abbreviated as 'mt'. The following changes were made:
5734 dump-me -> maintenance dump-me
5735 info all-breakpoints -> maintenance info breakpoints
5736 printmsyms -> maintenance print msyms
5737 printobjfiles -> maintenance print objfiles
5738 printpsyms -> maintenance print psymbols
5739 printsyms -> maintenance print symbols
5741 The following commands are new:
5743 maintenance demangle Call internal GDB demangler routine to
5744 demangle a C++ link name and prints the result.
5745 maintenance print type Print a type chain for a given symbol
5747 * Change to .gdbinit file processing
5749 We now read the $HOME/.gdbinit file before processing the argv arguments
5750 (e.g. reading symbol files or core files). This allows global parameters to
5751 be set, which will apply during the symbol reading. The ./.gdbinit is still
5752 read after argv processing.
5754 * New hosts supported
5756 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5758 GNU/Linux support i386-unknown-linux or linux
5760 We are also including code to support the HP/PA running BSD and HPUX. This
5761 is almost guaranteed not to work, as we didn't have time to test or build it
5762 for this release. We are including it so that the more adventurous (or
5763 masochistic) of you can play with it. We also had major problems with the
5764 fact that the compiler that we got from HP doesn't support the -g option.
5767 * New targets supported
5769 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5771 * More smarts about finding #include files
5773 GDB now remembers the compilation directory for all include files, and for
5774 all files from which C is generated (like yacc and lex sources). This
5775 greatly improves GDB's ability to find yacc/lex sources, and include files,
5776 especially if you are debugging your program from a directory different from
5777 the one that contains your sources.
5779 We also fixed a bug which caused difficulty with listing and setting
5780 breakpoints in include files which contain C code. (In the past, you had to
5781 try twice in order to list an include file that you hadn't looked at before.)
5783 * Interesting infernals change
5785 GDB now deals with arbitrary numbers of sections, where the symbols for each
5786 section must be relocated relative to that section's landing place in the
5787 target's address space. This work was needed to support ELF with embedded
5788 stabs used by Solaris-2.0.
5790 * Bug fixes (of course!)
5792 There have been loads of fixes for the following things:
5793 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5794 i960, stabs, DOS(GO32), procfs, etc...
5796 See the ChangeLog for details.
5798 *** Changes in GDB-4.5:
5800 * New machines supported (host and target)
5802 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5804 SGI Irix-4.x mips-sgi-irix4 or iris4
5806 * New malloc package
5808 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5809 Mmalloc is capable of handling mutiple heaps of memory. It is also
5810 capable of saving a heap to a file, and then mapping it back in later.
5811 This can be used to greatly speedup the startup of GDB by using a
5812 pre-parsed symbol table which lives in a mmalloc managed heap. For
5813 more details, please read mmalloc/mmalloc.texi.
5817 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5818 'help info proc' for details.
5820 * MIPS ecoff symbol table format
5822 The code that reads MIPS symbol table format is now supported on all hosts.
5823 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5826 * File name changes for MS-DOS
5828 Many files in the config directories have been renamed to make it easier to
5829 support GDB on MS-DOSe systems (which have very restrictive file name
5830 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5831 environment) is close to working but has some remaining problems. Note
5832 that debugging of DOS programs is not supported, due to limitations
5833 in the ``operating system'', but it can be used to host cross-debugging.
5835 * Cross byte order fixes
5837 Many fixes have been made to support cross debugging of Sparc and MIPS
5838 targets from hosts whose byte order differs.
5840 * New -mapped and -readnow options
5842 If memory-mapped files are available on your system through the 'mmap'
5843 system call, you can use the -mapped option on the `file' or
5844 `symbol-file' commands to cause GDB to write the symbols from your
5845 program into a reusable file. If the program you are debugging is
5846 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5847 Future GDB debugging sessions will notice the presence of this file,
5848 and will quickly map in symbol information from it, rather than reading
5849 the symbol table from the executable program. Using the '-mapped'
5850 option in a GDB `file' or `symbol-file' command has the same effect as
5851 starting GDB with the '-mapped' command-line option.
5853 You can cause GDB to read the entire symbol table immediately by using
5854 the '-readnow' option with any of the commands that load symbol table
5855 information (or on the GDB command line). This makes the command
5856 slower, but makes future operations faster.
5858 The -mapped and -readnow options are typically combined in order to
5859 build a `fred.syms' file that contains complete symbol information.
5860 A simple GDB invocation to do nothing but build a `.syms' file for future
5863 gdb -batch -nx -mapped -readnow programname
5865 The `.syms' file is specific to the host machine on which GDB is run.
5866 It holds an exact image of GDB's internal symbol table. It cannot be
5867 shared across multiple host platforms.
5869 * longjmp() handling
5871 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5872 siglongjmp() without losing control. This feature has not yet been ported to
5873 all systems. It currently works on many 386 platforms, all MIPS-based
5874 platforms (SGI, DECstation, etc), and Sun3/4.
5878 Preliminary work has been put in to support the new Solaris OS from Sun. At
5879 this time, it can control and debug processes, but it is not capable of
5884 As always, many many bug fixes. The major areas were with g++, and mipsread.
5885 People using the MIPS-based platforms should experience fewer mysterious
5886 crashes and trashed symbol tables.
5888 *** Changes in GDB-4.4:
5890 * New machines supported (host and target)
5892 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5894 BSD Reno on Vax vax-dec-bsd
5895 Ultrix on Vax vax-dec-ultrix
5897 * New machines supported (target)
5899 AMD 29000 embedded, using EBMON a29k-none-none
5903 GDB continues to improve its handling of C++. `References' work better.
5904 The demangler has also been improved, and now deals with symbols mangled as
5905 per the Annotated C++ Reference Guide.
5907 GDB also now handles `stabs' symbol information embedded in MIPS
5908 `ecoff' symbol tables. Since the ecoff format was not easily
5909 extensible to handle new languages such as C++, this appeared to be a
5910 good way to put C++ debugging info into MIPS binaries. This option
5911 will be supported in the GNU C compiler, version 2, when it is
5914 * New features for SVR4
5916 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5917 shared libraries. Debugging dynamically linked programs should present
5918 only minor differences from debugging statically linked programs.
5920 The `info proc' command will print out information about any process
5921 on an SVR4 system (including the one you are debugging). At the moment,
5922 it prints the address mappings of the process.
5924 If you bring up GDB on another SVR4 system, please send mail to
5925 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5927 * Better dynamic linking support in SunOS
5929 Reading symbols from shared libraries which contain debugging symbols
5930 now works properly. However, there remain issues such as automatic
5931 skipping of `transfer vector' code during function calls, which
5932 make it harder to debug code in a shared library, than to debug the
5933 same code linked statically.
5937 GDB is now using the latest `getopt' routines from the FSF. This
5938 version accepts the -- prefix for options with long names. GDB will
5939 continue to accept the old forms (-option and +option) as well.
5940 Various single letter abbreviations for options have been explicity
5941 added to the option table so that they won't get overshadowed in the
5942 future by other options that begin with the same letter.
5946 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5947 Many assorted bugs have been handled. Many more remain to be handled.
5948 See the various ChangeLog files (primarily in gdb and bfd) for details.
5951 *** Changes in GDB-4.3:
5953 * New machines supported (host and target)
5955 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5956 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5957 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5959 * Almost SCO Unix support
5961 We had hoped to support:
5962 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5963 (except for core file support), but we discovered very late in the release
5964 that it has problems with process groups that render gdb unusable. Sorry
5965 about that. I encourage people to fix it and post the fixes.
5967 * Preliminary ELF and DWARF support
5969 GDB can read ELF object files on System V Release 4, and can handle
5970 debugging records for C, in DWARF format, in ELF files. This support
5971 is preliminary. If you bring up GDB on another SVR4 system, please
5972 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5977 GDB now uses the latest `readline' library. One user-visible change
5978 is that two tabs will list possible command completions, which previously
5979 required typing M-? (meta-question mark, or ESC ?).
5983 The `stepi' bug that many of you noticed has been squashed.
5984 Many bugs in C++ have been handled. Many more remain to be handled.
5985 See the various ChangeLog files (primarily in gdb and bfd) for details.
5987 * State of the MIPS world (in case you wondered):
5989 GDB can understand the symbol tables emitted by the compilers
5990 supplied by most vendors of MIPS-based machines, including DEC. These
5991 symbol tables are in a format that essentially nobody else uses.
5993 Some versions of gcc come with an assembler post-processor called
5994 mips-tfile. This program is required if you want to do source-level
5995 debugging of gcc-compiled programs. I believe FSF does not ship
5996 mips-tfile with gcc version 1, but it will eventually come with gcc
5999 Debugging of g++ output remains a problem. g++ version 1.xx does not
6000 really support it at all. (If you're lucky, you should be able to get
6001 line numbers and stack traces to work, but no parameters or local
6002 variables.) With some work it should be possible to improve the
6005 When gcc version 2 is released, you will have somewhat better luck.
6006 However, even then you will get confusing results for inheritance and
6009 We will eventually provide full debugging of g++ output on
6010 DECstations. This will probably involve some kind of stabs-in-ecoff
6011 encapulation, but the details have not been worked out yet.
6014 *** Changes in GDB-4.2:
6016 * Improved configuration
6018 Only one copy of `configure' exists now, and it is not self-modifying.
6019 Porting BFD is simpler.
6023 The `step' and `next' commands now only stop at the first instruction
6024 of a source line. This prevents the multiple stops that used to occur
6025 in switch statements, for-loops, etc. `Step' continues to stop if a
6026 function that has debugging information is called within the line.
6030 Lots of small bugs fixed. More remain.
6032 * New host supported (not target)
6034 Intel 386 PC clone running Mach i386-none-mach
6037 *** Changes in GDB-4.1:
6039 * Multiple source language support
6041 GDB now has internal scaffolding to handle several source languages.
6042 It determines the type of each source file from its filename extension,
6043 and will switch expression parsing and number formatting to match the
6044 language of the function in the currently selected stack frame.
6045 You can also specifically set the language to be used, with
6046 `set language c' or `set language modula-2'.
6050 GDB now has preliminary support for the GNU Modula-2 compiler,
6051 currently under development at the State University of New York at
6052 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6053 continue through the fall of 1991 and into 1992.
6055 Other Modula-2 compilers are currently not supported, and attempting to
6056 debug programs compiled with them will likely result in an error as the
6057 symbol table is read. Feel free to work on it, though!
6059 There are hooks in GDB for strict type checking and range checking,
6060 in the `Modula-2 philosophy', but they do not currently work.
6064 GDB can now write to executable and core files (e.g. patch
6065 a variable's value). You must turn this switch on, specify
6066 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6067 by assigning a new value to a variable. Modifications take
6070 * Automatic SunOS shared library reading
6072 When you run your program, GDB automatically determines where its
6073 shared libraries (if any) have been loaded, and reads their symbols.
6074 The `share' command is no longer needed. This also works when
6075 examining core files.
6079 You can specify the number of lines that the `list' command shows.
6082 * New machines supported (host and target)
6084 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6085 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6086 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6088 * New hosts supported (not targets)
6090 IBM RT/PC: romp-ibm-aix or rtpc
6092 * New targets supported (not hosts)
6094 AMD 29000 embedded with COFF a29k-none-coff
6095 AMD 29000 embedded with a.out a29k-none-aout
6096 Ultracomputer remote kernel debug a29k-nyu-kern
6098 * New remote interfaces
6104 *** Changes in GDB-4.0:
6108 Wide output is wrapped at good places to make the output more readable.
6110 Gdb now supports cross-debugging from a host machine of one type to a
6111 target machine of another type. Communication with the target system
6112 is over serial lines. The ``target'' command handles connecting to the
6113 remote system; the ``load'' command will download a program into the
6114 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6115 also supports debugging of realtime processes running under VxWorks,
6116 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6117 stub on the target system.
6119 New CPUs supported include the AMD 29000 and Intel 960.
6121 GDB now reads object files and symbol tables via a ``binary file''
6122 library, which allows a single copy of GDB to debug programs of multiple
6123 object file types such as a.out and coff.
6125 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6126 refcard.dvi and refcard.ps are available to format it).
6129 * Control-Variable user interface simplified
6131 All variables that control the operation of the debugger can be set
6132 by the ``set'' command, and displayed by the ``show'' command.
6134 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6135 ``Show prompt'' produces the response:
6136 Gdb's prompt is new-gdb=>.
6138 What follows are the NEW set commands. The command ``help set'' will
6139 print a complete list of old and new set commands. ``help set FOO''
6140 will give a longer description of the variable FOO. ``show'' will show
6141 all of the variable descriptions and their current settings.
6143 confirm on/off: Enables warning questions for operations that are
6144 hard to recover from, e.g. rerunning the program while
6145 it is already running. Default is ON.
6147 editing on/off: Enables EMACS style command line editing
6148 of input. Previous lines can be recalled with
6149 control-P, the current line can be edited with control-B,
6150 you can search for commands with control-R, etc.
6153 history filename NAME: NAME is where the gdb command history
6154 will be stored. The default is .gdb_history,
6155 or the value of the environment variable
6158 history size N: The size, in commands, of the command history. The
6159 default is 256, or the value of the environment variable
6162 history save on/off: If this value is set to ON, the history file will
6163 be saved after exiting gdb. If set to OFF, the
6164 file will not be saved. The default is OFF.
6166 history expansion on/off: If this value is set to ON, then csh-like
6167 history expansion will be performed on
6168 command line input. The default is OFF.
6170 radix N: Sets the default radix for input and output. It can be set
6171 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6172 in the current radix, so "set radix 10" is always a no-op.
6174 height N: This integer value is the number of lines on a page. Default
6175 is 24, the current `stty rows'' setting, or the ``li#''
6176 setting from the termcap entry matching the environment
6179 width N: This integer value is the number of characters on a line.
6180 Default is 80, the current `stty cols'' setting, or the ``co#''
6181 setting from the termcap entry matching the environment
6184 Note: ``set screensize'' is obsolete. Use ``set height'' and
6185 ``set width'' instead.
6187 print address on/off: Print memory addresses in various command displays,
6188 such as stack traces and structure values. Gdb looks
6189 more ``symbolic'' if you turn this off; it looks more
6190 ``machine level'' with it on. Default is ON.
6192 print array on/off: Prettyprint arrays. New convenient format! Default
6195 print demangle on/off: Print C++ symbols in "source" form if on,
6198 print asm-demangle on/off: Same, for assembler level printouts
6201 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6204 * Support for Epoch Environment.
6206 The epoch environment is a version of Emacs v18 with windowing. One
6207 new command, ``inspect'', is identical to ``print'', except that if you
6208 are running in the epoch environment, the value is printed in its own
6212 * Support for Shared Libraries
6214 GDB can now debug programs and core files that use SunOS shared libraries.
6215 Symbols from a shared library cannot be referenced
6216 before the shared library has been linked with the program (this
6217 happens after you type ``run'' and before the function main() is entered).
6218 At any time after this linking (including when examining core files
6219 from dynamically linked programs), gdb reads the symbols from each
6220 shared library when you type the ``sharedlibrary'' command.
6221 It can be abbreviated ``share''.
6223 sharedlibrary REGEXP: Load shared object library symbols for files
6224 matching a unix regular expression. No argument
6225 indicates to load symbols for all shared libraries.
6227 info sharedlibrary: Status of loaded shared libraries.
6232 A watchpoint stops execution of a program whenever the value of an
6233 expression changes. Checking for this slows down execution
6234 tremendously whenever you are in the scope of the expression, but is
6235 quite useful for catching tough ``bit-spreader'' or pointer misuse
6236 problems. Some machines such as the 386 have hardware for doing this
6237 more quickly, and future versions of gdb will use this hardware.
6239 watch EXP: Set a watchpoint (breakpoint) for an expression.
6241 info watchpoints: Information about your watchpoints.
6243 delete N: Deletes watchpoint number N (same as breakpoints).
6244 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6245 enable N: Re-enables watchpoint number N (same as breakpoints).
6248 * C++ multiple inheritance
6250 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6253 * C++ exception handling
6255 Gdb now supports limited C++ exception handling. Besides the existing
6256 ability to breakpoint on an exception handler, gdb can breakpoint on
6257 the raising of an exception (before the stack is peeled back to the
6260 catch FOO: If there is a FOO exception handler in the dynamic scope,
6261 set a breakpoint to catch exceptions which may be raised there.
6262 Multiple exceptions (``catch foo bar baz'') may be caught.
6264 info catch: Lists all exceptions which may be caught in the
6265 current stack frame.
6268 * Minor command changes
6270 The command ``call func (arg, arg, ...)'' now acts like the print
6271 command, except it does not print or save a value if the function's result
6272 is void. This is similar to dbx usage.
6274 The ``up'' and ``down'' commands now always print the frame they end up
6275 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6276 frames without printing.
6278 * New directory command
6280 'dir' now adds directories to the FRONT of the source search path.
6281 The path starts off empty. Source files that contain debug information
6282 about the directory in which they were compiled can be found even
6283 with an empty path; Sun CC and GCC include this information. If GDB can't
6284 find your source file in the current directory, type "dir .".
6286 * Configuring GDB for compilation
6288 For normal use, type ``./configure host''. See README or gdb.texinfo
6291 GDB now handles cross debugging. If you are remotely debugging between
6292 two different machines, type ``./configure host -target=targ''.
6293 Host is the machine where GDB will run; targ is the machine
6294 where the program that you are debugging will run.