1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.10
6 * Record btrace now supports non-stop mode.
8 * Support for tracepoints on aarch64-linux was added in GDBserver.
10 * The 'record instruction-history' command now indicates speculative execution
11 when using the Intel(R) Processor Trace recording format.
13 * GDB now allows users to specify explicit locations, bypassing
14 the linespec parser. This feature is also available to GDB/MI
17 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
18 GDB now is able to debug both AArch64 applications and ARM applications
21 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
22 including JIT compiling fast tracepoint's conditional expression bytecode
25 * GDB now supports displaced stepping on AArch64 GNU/Linux.
27 * "info threads", "info inferiors", "info display", "info checkpoints"
28 and "maint info program-spaces" now list the corresponding items in
29 ascending ID order, for consistency with all other "info" commands.
33 maint set target-non-stop (on|off|auto)
34 maint show target-non-stop
35 Control whether GDB targets always operate in non-stop mode even if
36 "set non-stop" is "off". The default is "auto", meaning non-stop
37 mode is enabled if supported by the target.
40 maint show bfd-sharing
41 Control the reuse of bfd objects.
45 Control display of debugging info regarding bfd caching.
47 set remote multiprocess-extensions-packet
48 show remote multiprocess-extensions-packet
49 Set/show the use of the remote protocol multiprocess extensions.
51 set remote thread-events
52 show remote thread-events
53 Set/show the use of thread create/exit events.
55 * The "disassemble" command accepts a new modifier: /s.
56 It prints mixed source+disassembly like /m with two differences:
57 - disassembled instructions are now printed in program order, and
58 - and source for all relevant files is now printed.
59 The "/m" option is now considered deprecated: its "source-centric"
60 output hasn't proved useful in practice.
62 * The "record instruction-history" command accepts a new modifier: /s.
63 It behaves exactly like /m and prints mixed source+disassembly.
65 * The "set scheduler-locking" command supports a new mode "replay".
66 It behaves like "off" in record mode and like "on" in replay mode.
68 * Support for various ROM monitors has been removed:
70 target dbug dBUG ROM monitor for Motorola ColdFire
71 target picobug Motorola picobug monitor
72 target dink32 DINK32 ROM monitor for PowerPC
73 target m32r Renesas M32R/D ROM monitor
74 target mon2000 mon2000 ROM monitor
75 target ppcbug PPCBUG ROM monitor for PowerPC
77 * Support for reading/writing memory and extracting values on architectures
78 whose memory is addressable in units of any integral multiple of 8 bits.
83 Indicates that an exec system call was executed.
85 exec-events feature in qSupported
86 The qSupported packet allows GDB to request support for exec
87 events using the new 'gdbfeature' exec-event, and the qSupported
88 response can contain the corresponding 'stubfeature'. Set and
89 show commands can be used to display whether these features are enabled.
92 Equivalent to interrupting with the ^C character, but works in
95 thread created stop reason (T05 create:...)
96 Indicates that the thread was just created and is stopped at entry.
98 thread exit stop reply (w exitcode;tid)
99 Indicates that the thread has terminated.
102 Enables/disables thread create and exit event reporting. For
103 example, this is used in non-stop mode when GDB stops a set of
104 threads and synchronously waits for the their corresponding stop
105 replies. Without exit events, if one of the threads exits, GDB
106 would hang forever not knowing that it should no longer expect a
107 stop for that same thread.
109 * Extended-remote exec events
111 ** GDB now has support for exec events on extended-remote Linux targets.
112 For such targets with Linux kernels 2.5.46 and later, this enables
113 follow-exec-mode and exec catchpoints.
115 set remote exec-event-feature-packet
116 show remote exec-event-feature-packet
117 Set/show the use of the remote exec event feature.
119 * Thread names in remote protocol
121 The reply to qXfer:threads:read may now include a name attribute for each
124 *** Changes in GDB 7.10
126 * Support for process record-replay and reverse debugging on aarch64*-linux*
127 targets has been added. GDB now supports recording of A64 instruction set
128 including advance SIMD instructions.
130 * Support for Sun's version of the "stabs" debug file format has been removed.
132 * GDB now honors the content of the file /proc/PID/coredump_filter
133 (PID is the process ID) on GNU/Linux systems. This file can be used
134 to specify the types of memory mappings that will be included in a
135 corefile. For more information, please refer to the manual page of
136 "core(5)". GDB also has a new command: "set use-coredump-filter
137 on|off". It allows to set whether GDB will read the content of the
138 /proc/PID/coredump_filter file when generating a corefile.
140 * The "info os" command on GNU/Linux can now display information on
142 "info os cpus" Listing of all cpus/cores on the system
144 * GDB has two new commands: "set serial parity odd|even|none" and
145 "show serial parity". These allows to set or show parity for the
148 * The "info source" command now displays the producer string if it was
149 present in the debug info. This typically includes the compiler version
150 and may include things like its command line arguments.
152 * The "info dll", an alias of the "info sharedlibrary" command,
153 is now available on all platforms.
155 * Directory names supplied to the "set sysroot" commands may be
156 prefixed with "target:" to tell GDB to access shared libraries from
157 the target system, be it local or remote. This replaces the prefix
158 "remote:". The default sysroot has been changed from "" to
159 "target:". "remote:" is automatically converted to "target:" for
160 backward compatibility.
162 * The system root specified by "set sysroot" will be prepended to the
163 filename of the main executable (if reported to GDB as absolute by
164 the operating system) when starting processes remotely, and when
165 attaching to already-running local or remote processes.
167 * GDB now supports automatic location and retrieval of executable
168 files from remote targets. Remote debugging can now be initiated
169 using only a "target remote" or "target extended-remote" command
170 (no "set sysroot" or "file" commands are required). See "New remote
173 * The "dump" command now supports verilog hex format.
175 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
177 * On GNU/Linux, GDB and gdbserver are now able to access executable
178 and shared library files without a "set sysroot" command when
179 attaching to processes running in different mount namespaces from
180 the debugger. This makes it possible to attach to processes in
181 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
182 See "New remote packets" below.
184 * The "tui reg" command now provides completion for all of the
185 available register groups, including target specific groups.
187 * The HISTSIZE environment variable is no longer read when determining
188 the size of GDB's command history. GDB now instead reads the dedicated
189 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
190 disables truncation of command history. Non-numeric values of GDBHISTSIZE
195 ** Memory ports can now be unbuffered.
199 ** gdb.Objfile objects have a new attribute "username",
200 which is the name of the objfile as specified by the user,
201 without, for example, resolving symlinks.
202 ** You can now write frame unwinders in Python.
203 ** gdb.Type objects have a new method "optimized_out",
204 returning optimized out gdb.Value instance of this type.
205 ** gdb.Value objects have new methods "reference_value" and
206 "const_value" which return a reference to the value and a
207 "const" version of the value respectively.
211 maint print symbol-cache
212 Print the contents of the symbol cache.
214 maint print symbol-cache-statistics
215 Print statistics of symbol cache usage.
217 maint flush-symbol-cache
218 Flush the contents of the symbol cache.
222 Start branch trace recording using Branch Trace Store (BTS) format.
225 Evaluate expression by using the compiler and print result.
229 Explicit commands for enabling and disabling tui mode.
232 set mpx bound on i386 and amd64
233 Support for bound table investigation on Intel(R) MPX enabled applications.
237 Start branch trace recording using Intel(R) Processor Trace format.
240 Print information about branch tracing internals.
242 maint btrace packet-history
243 Print the raw branch tracing data.
245 maint btrace clear-packet-history
246 Discard the stored raw branch tracing data.
249 Discard all branch tracing data. It will be fetched and processed
250 anew by the next "record" command.
255 Renamed from "set debug dwarf2-die".
257 Renamed from "show debug dwarf2-die".
260 Renamed from "set debug dwarf2-read".
261 show debug dwarf-read
262 Renamed from "show debug dwarf2-read".
264 maint set dwarf always-disassemble
265 Renamed from "maint set dwarf2 always-disassemble".
266 maint show dwarf always-disassemble
267 Renamed from "maint show dwarf2 always-disassemble".
269 maint set dwarf max-cache-age
270 Renamed from "maint set dwarf2 max-cache-age".
271 maint show dwarf max-cache-age
272 Renamed from "maint show dwarf2 max-cache-age".
275 show debug dwarf-line
276 Control display of debugging info regarding DWARF line processing.
280 Set the maximum number of candidates to be considered during
281 completion. The default value is 200. This limit allows GDB
282 to avoid generating large completion lists, the computation of
283 which can cause the debugger to become temporarily unresponsive.
285 set history remove-duplicates
286 show history remove-duplicates
287 Control the removal of duplicate history entries.
289 maint set symbol-cache-size
290 maint show symbol-cache-size
291 Control the size of the symbol cache.
293 set|show record btrace bts buffer-size
294 Set and show the size of the ring buffer used for branch tracing in
296 The obtained size may differ from the requested size. Use "info
297 record" to see the obtained buffer size.
299 set debug linux-namespaces
300 show debug linux-namespaces
301 Control display of debugging info regarding Linux namespaces.
303 set|show record btrace pt buffer-size
304 Set and show the size of the ring buffer used for branch tracing in
305 Intel(R) Processor Trace format.
306 The obtained size may differ from the requested size. Use "info
307 record" to see the obtained buffer size.
309 maint set|show btrace pt skip-pad
310 Set and show whether PAD packets are skipped when computing the
313 * The command 'thread apply all' can now support new option '-ascending'
314 to call its specified command for all threads in ascending order.
316 * Python/Guile scripting
318 ** GDB now supports auto-loading of Python/Guile scripts contained in the
319 special section named `.debug_gdb_scripts'.
323 qXfer:btrace-conf:read
324 Return the branch trace configuration for the current thread.
326 Qbtrace-conf:bts:size
327 Set the requested ring buffer size for branch tracing in BTS format.
330 Enable Intel(R) Procesor Trace-based branch tracing for the current
331 process. The remote stub reports support for this packet to GDB's
335 Set the requested ring buffer size for branch tracing in Intel(R) Processor
339 Indicates a memory breakpoint instruction was executed, irrespective
340 of whether it was GDB that planted the breakpoint or the breakpoint
341 is hardcoded in the program. This is required for correct non-stop
345 Indicates the target stopped for a hardware breakpoint. This is
346 required for correct non-stop mode operation.
349 Return information about files on the remote system.
352 Return the full absolute name of the file that was executed to
353 create a process running on the remote system.
356 Select the filesystem on which vFile: operations with filename
357 arguments will operate. This is required for GDB to be able to
358 access files on remote targets where the remote stub does not
359 share a common filesystem with the inferior(s).
362 Indicates that a fork system call was executed.
365 Indicates that a vfork system call was executed.
367 vforkdone stop reason
368 Indicates that a vfork child of the specified process has executed
369 an exec or exit, allowing the vfork parent to resume execution.
371 fork-events and vfork-events features in qSupported
372 The qSupported packet allows GDB to request support for fork and
373 vfork events using new 'gdbfeatures' fork-events and vfork-events,
374 and the qSupported response can contain the corresponding
375 'stubfeatures'. Set and show commands can be used to display
376 whether these features are enabled.
378 * Extended-remote fork events
380 ** GDB now has support for fork events on extended-remote Linux
381 targets. For targets with Linux kernels 2.5.60 and later, this
382 enables follow-fork-mode and detach-on-fork for both fork and
383 vfork, as well as fork and vfork catchpoints.
385 * The info record command now shows the recording format and the
386 branch tracing configuration for the current thread when using
387 the btrace record target.
388 For the BTS format, it shows the ring buffer size.
390 * GDB now has support for DTrace USDT (Userland Static Defined
391 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
393 * GDB now supports access to vector registers on S/390 GNU/Linux
396 * Removed command line options
398 -xdb HP-UX XDB compatibility mode.
400 * Removed targets and native configurations
402 HP/PA running HP-UX hppa*-*-hpux*
403 Itanium running HP-UX ia64-*-hpux*
405 * New configure options
408 This configure option allows the user to build GDB with support for
409 Intel(R) Processor Trace (default: auto). This requires libipt.
411 --with-libipt-prefix=PATH
412 Specify the path to the version of libipt that GDB should use.
413 $PATH/include should contain the intel-pt.h header and
414 $PATH/lib should contain the libipt.so library.
416 *** Changes in GDB 7.9.1
420 ** Xmethods can now specify a result type.
422 *** Changes in GDB 7.9
424 * GDB now supports hardware watchpoints on x86 GNU Hurd.
428 ** You can now access frame registers from Python scripts.
429 ** New attribute 'producer' for gdb.Symtab objects.
430 ** gdb.Objfile objects have a new attribute "progspace",
431 which is the gdb.Progspace object of the containing program space.
432 ** gdb.Objfile objects have a new attribute "owner".
433 ** gdb.Objfile objects have a new attribute "build_id",
434 which is the build ID generated when the file was built.
435 ** gdb.Objfile objects have a new method "add_separate_debug_file".
436 ** A new event "gdb.clear_objfiles" has been added, triggered when
437 selecting a new file to debug.
438 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
439 ** New function gdb.lookup_objfile.
441 New events which are triggered when GDB modifies the state of the
444 ** gdb.events.inferior_call_pre: Function call is about to be made.
445 ** gdb.events.inferior_call_post: Function call has just been made.
446 ** gdb.events.memory_changed: A memory location has been altered.
447 ** gdb.events.register_changed: A register has been altered.
449 * New Python-based convenience functions:
451 ** $_caller_is(name [, number_of_frames])
452 ** $_caller_matches(regexp [, number_of_frames])
453 ** $_any_caller_is(name [, number_of_frames])
454 ** $_any_caller_matches(regexp [, number_of_frames])
456 * GDB now supports the compilation and injection of source code into
457 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
458 to compile the source code to object code, and if successful, inject
459 and execute that code within the current context of the inferior.
460 Currently the C language is supported. The commands used to
461 interface with this new feature are:
463 compile code [-raw|-r] [--] [source code]
464 compile file [-raw|-r] filename
468 demangle [-l language] [--] name
469 Demangle "name" in the specified language, or the current language
470 if elided. This command is renamed from the "maint demangle" command.
471 The latter is kept as a no-op to avoid "maint demangle" being interpreted
472 as "maint demangler-warning".
474 queue-signal signal-name-or-number
475 Queue a signal to be delivered to the thread when it is resumed.
477 add-auto-load-scripts-directory directory
478 Add entries to the list of directories from which to load auto-loaded
481 maint print user-registers
482 List all currently available "user" registers.
484 compile code [-r|-raw] [--] [source code]
485 Compile, inject, and execute in the inferior the executable object
486 code produced by compiling the provided source code.
488 compile file [-r|-raw] filename
489 Compile and inject into the inferior the executable object code
490 produced by compiling the source code stored in the filename
493 * On resume, GDB now always passes the signal the program had stopped
494 for to the thread the signal was sent to, even if the user changed
495 threads before resuming. Previously GDB would often (but not
496 always) deliver the signal to the thread that happens to be current
499 * Conversely, the "signal" command now consistently delivers the
500 requested signal to the current thread. GDB now asks for
501 confirmation if the program had stopped for a signal and the user
502 switched threads meanwhile.
504 * "breakpoint always-inserted" modes "off" and "auto" merged.
506 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
507 won't remove breakpoints from the target until all threads stop,
508 even in non-stop mode. The "auto" mode has been removed, and "off"
509 is now the default mode.
513 set debug symbol-lookup
514 show debug symbol-lookup
515 Control display of debugging info regarding symbol lookup.
519 ** The -list-thread-groups command outputs an exit-code field for
520 inferiors that have exited.
524 MIPS SDE mips*-sde*-elf*
528 Support for these obsolete configurations has been removed.
530 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
531 SGI Irix-5.x mips-*-irix5*
532 SGI Irix-6.x mips-*-irix6*
533 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
534 VAX running Ultrix vax-*-ultrix*
536 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
537 and "assf"), have been removed. Use the "sharedlibrary" command, or
538 its alias "share", instead.
540 *** Changes in GDB 7.8
542 * New command line options
545 This is an alias for the --data-directory option.
547 * GDB supports printing and modifying of variable length automatic arrays
548 as specified in ISO C99.
550 * The ARM simulator now supports instruction level tracing
551 with or without disassembly.
555 GDB now has support for scripting using Guile. Whether this is
556 available is determined at configure time.
557 Guile version 2.0 or greater is required.
558 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
560 * New commands (for set/show, see "New options" below)
564 Invoke CODE by passing it to the Guile interpreter.
568 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
570 info auto-load guile-scripts [regexp]
571 Print the list of automatically loaded Guile scripts.
573 * The source command is now capable of sourcing Guile scripts.
574 This feature is dependent on the debugger being built with Guile support.
578 set print symbol-loading (off|brief|full)
579 show print symbol-loading
580 Control whether to print informational messages when loading symbol
581 information for a file. The default is "full", but when debugging
582 programs with large numbers of shared libraries the amount of output
585 set guile print-stack (none|message|full)
586 show guile print-stack
587 Show a stack trace when an error is encountered in a Guile script.
589 set auto-load guile-scripts (on|off)
590 show auto-load guile-scripts
591 Control auto-loading of Guile script files.
593 maint ada set ignore-descriptive-types (on|off)
594 maint ada show ignore-descriptive-types
595 Control whether the debugger should ignore descriptive types in Ada
596 programs. The default is not to ignore the descriptive types. See
597 the user manual for more details on descriptive types and the intended
598 usage of this option.
600 set auto-connect-native-target
602 Control whether GDB is allowed to automatically connect to the
603 native target for the run, attach, etc. commands when not connected
604 to any target yet. See also "target native" below.
606 set record btrace replay-memory-access (read-only|read-write)
607 show record btrace replay-memory-access
608 Control what memory accesses are allowed during replay.
610 maint set target-async (on|off)
611 maint show target-async
612 This controls whether GDB targets operate in synchronous or
613 asynchronous mode. Normally the default is asynchronous, if it is
614 available; but this can be changed to more easily debug problems
615 occurring only in synchronous mode.
617 set mi-async (on|off)
619 Control whether MI asynchronous mode is preferred. This supersedes
620 "set target-async" of previous GDB versions.
622 * "set target-async" is deprecated as a CLI option and is now an alias
623 for "set mi-async" (only puts MI into async mode).
625 * Background execution commands (e.g., "c&", "s&", etc.) are now
626 possible ``out of the box'' if the target supports them. Previously
627 the user would need to explicitly enable the possibility with the
628 "set target-async on" command.
630 * New features in the GDB remote stub, GDBserver
632 ** New option --debug-format=option1[,option2,...] allows one to add
633 additional text to each output. At present only timestamps
634 are supported: --debug-format=timestamps.
635 Timestamps can also be turned on with the
636 "monitor set debug-format timestamps" command from GDB.
638 * The 'record instruction-history' command now starts counting instructions
639 at one. This also affects the instruction ranges reported by the
640 'record function-call-history' command when given the /i modifier.
642 * The command 'record function-call-history' supports a new modifier '/c' to
643 indent the function names based on their call stack depth.
644 The fields for the '/i' and '/l' modifier have been reordered.
645 The source line range is now prefixed with 'at'.
646 The instruction range is now prefixed with 'inst'.
647 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
648 "record instruction-history" and "list" commands.
650 * The ranges given as arguments to the 'record function-call-history' and
651 'record instruction-history' commands are now inclusive.
653 * The btrace record target now supports the 'record goto' command.
654 For locations inside the execution trace, the back trace is computed
655 based on the information stored in the execution trace.
657 * The btrace record target supports limited reverse execution and replay.
658 The target does not record data and therefore does not allow reading
661 * The "catch syscall" command now works on s390*-linux* targets.
663 * The "compare-sections" command is no longer specific to target
664 remote. It now works with all targets.
666 * All native targets are now consistently called "native".
667 Consequently, the "target child", "target GNU", "target djgpp",
668 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
669 commands have been replaced with "target native". The QNX/NTO port
670 leaves the "procfs" target in place and adds a "native" target for
671 consistency with other ports. The impact on users should be minimal
672 as these commands previously either throwed an error, or were
673 no-ops. The target's name is visible in the output of the following
674 commands: "help target", "info target", "info files", "maint print
677 * The "target native" command now connects to the native target. This
678 can be used to launch native programs even when "set
679 auto-connect-native-target" is set to off.
681 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.
683 * Support for Intel(R) AVX-512 registers on GNU/Linux.
684 Support displaying and modifying Intel(R) AVX-512 registers
685 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
689 qXfer:btrace:read's annex
690 The qXfer:btrace:read packet supports a new annex 'delta' to read
691 branch trace incrementally.
695 ** Valid Python operations on gdb.Value objects representing
696 structs/classes invoke the corresponding overloaded operators if
698 ** New `Xmethods' feature in the Python API. Xmethods are
699 additional methods or replacements for existing methods of a C++
700 class. This feature is useful for those cases where a method
701 defined in C++ source code could be inlined or optimized out by
702 the compiler, making it unavailable to GDB.
705 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
707 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
708 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
709 its alias "share", instead.
711 * The commands "set remotebaud" and "show remotebaud" are no longer
712 supported. Use "set serial baud" and "show serial baud" (respectively)
717 ** A new option "-gdb-set mi-async" replaces "-gdb-set
718 target-async". The latter is left as a deprecated alias of the
719 former for backward compatibility. If the target supports it,
720 CLI background execution commands are now always possible by
721 default, independently of whether the frontend stated a
722 preference for asynchronous execution with "-gdb-set mi-async".
723 Previously "-gdb-set target-async off" affected both MI execution
724 commands and CLI execution commands.
726 *** Changes in GDB 7.7
728 * Improved support for process record-replay and reverse debugging on
729 arm*-linux* targets. Support for thumb32 and syscall instruction
730 recording has been added.
732 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
734 * GDB now supports Fission DWP file format version 2.
735 http://gcc.gnu.org/wiki/DebugFission
737 * New convenience function "$_isvoid", to check whether an expression
738 is void. A void expression is an expression where the type of the
739 result is "void". For example, some convenience variables may be
740 "void" when evaluated (e.g., "$_exitcode" before the execution of
741 the program being debugged; or an undefined convenience variable).
742 Another example, when calling a function whose return type is
745 * The "maintenance print objfiles" command now takes an optional regexp.
747 * The "catch syscall" command now works on arm*-linux* targets.
749 * GDB now consistently shows "<not saved>" when printing values of
750 registers the debug info indicates have not been saved in the frame
751 and there's nowhere to retrieve them from
752 (callee-saved/call-clobbered registers):
757 (gdb) info registers rax
760 Before, the former would print "<optimized out>", and the latter
761 "*value not available*".
763 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
768 ** Frame filters and frame decorators have been added.
769 ** Temporary breakpoints are now supported.
770 ** Line tables representation has been added.
771 ** New attribute 'parent_type' for gdb.Field objects.
772 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
773 ** New attribute 'name' for gdb.Type objects.
777 Nios II ELF nios2*-*-elf
778 Nios II GNU/Linux nios2*-*-linux
779 Texas Instruments MSP430 msp430*-*-elf
781 * Removed native configurations
783 Support for these a.out NetBSD and OpenBSD obsolete configurations has
784 been removed. ELF variants of these configurations are kept supported.
786 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
787 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
788 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
789 i[34567]86-*-openbsd3.[0-3]
790 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
791 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
792 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
796 Like "catch throw", but catches a re-thrown exception.
798 Renamed from old "maint check-symtabs".
800 Perform consistency checks on symtabs.
802 Expand symtabs matching an optional regexp.
805 Display the details of GDB configure-time options.
807 maint set|show per-command
808 maint set|show per-command space
809 maint set|show per-command time
810 maint set|show per-command symtab
811 Enable display of per-command gdb resource usage.
813 remove-symbol-file FILENAME
814 remove-symbol-file -a ADDRESS
815 Remove a symbol file added via add-symbol-file. The file to remove
816 can be identified by its filename or by an address that lies within
817 the boundaries of this symbol file in memory.
820 info exceptions REGEXP
821 Display the list of Ada exceptions defined in the program being
822 debugged. If provided, only the exceptions whose names match REGEXP
827 set debug symfile off|on
829 Control display of debugging info regarding reading symbol files and
830 symbol tables within those files
832 set print raw frame-arguments
833 show print raw frame-arguments
834 Set/show whether to print frame arguments in raw mode,
835 disregarding any defined pretty-printers.
837 set remote trace-status-packet
838 show remote trace-status-packet
839 Set/show the use of remote protocol qTStatus packet.
843 Control display of debugging messages related to Nios II targets.
847 Control whether target-assisted range stepping is enabled.
849 set startup-with-shell
850 show startup-with-shell
851 Specifies whether Unix child processes are started via a shell or
856 Use the target memory cache for accesses to the code segment. This
857 improves performance of remote debugging (particularly disassembly).
859 * You can now use a literal value 'unlimited' for options that
860 interpret 0 or -1 as meaning "unlimited". E.g., "set
861 trace-buffer-size unlimited" is now an alias for "set
862 trace-buffer-size -1" and "set height unlimited" is now an alias for
865 * The "set debug symtab-create" debugging option of GDB has been changed to
866 accept a verbosity level. 0 means "off", 1 provides basic debugging
867 output, and values of 2 or greater provides more verbose output.
869 * New command-line options
871 Display the details of GDB configure-time options.
873 * The command 'tsave' can now support new option '-ctf' to save trace
874 buffer in Common Trace Format.
876 * Newly installed $prefix/bin/gcore acts as a shell interface for the
879 * GDB now implements the the C++ 'typeid' operator.
881 * The new convenience variable $_exception holds the exception being
882 thrown or caught at an exception-related catchpoint.
884 * The exception-related catchpoints, like "catch throw", now accept a
885 regular expression which can be used to filter exceptions by type.
887 * The new convenience variable $_exitsignal is automatically set to
888 the terminating signal number when the program being debugged dies
889 due to an uncaught signal.
893 ** All MI commands now accept an optional "--language" option.
894 Support for this feature can be verified by using the "-list-features"
895 command, which should contain "language-option".
897 ** The new command -info-gdb-mi-command allows the user to determine
898 whether a GDB/MI command is supported or not.
900 ** The "^error" result record returned when trying to execute an undefined
901 GDB/MI command now provides a variable named "code" whose content is the
902 "undefined-command" error code. Support for this feature can be verified
903 by using the "-list-features" command, which should contain
904 "undefined-command-error-code".
906 ** The -trace-save MI command can optionally save trace buffer in Common
909 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
911 ** The command -data-list-register-values now accepts an optional
912 "--skip-unavailable" option. When used, only the available registers
915 ** The new command -trace-frame-collected dumps collected variables,
916 computed expressions, tvars, memory and registers in a traceframe.
918 ** The commands -stack-list-locals, -stack-list-arguments and
919 -stack-list-variables now accept an option "--skip-unavailable".
920 When used, only the available locals or arguments are displayed.
922 ** The -exec-run command now accepts an optional "--start" option.
923 When used, the command follows the same semantics as the "start"
924 command, stopping the program's execution at the start of its
925 main subprogram. Support for this feature can be verified using
926 the "-list-features" command, which should contain
927 "exec-run-start-option".
929 ** The new commands -catch-assert and -catch-exceptions insert
930 catchpoints stopping the program when Ada exceptions are raised.
932 ** The new command -info-ada-exceptions provides the equivalent of
933 the new "info exceptions" command.
935 * New system-wide configuration scripts
936 A GDB installation now provides scripts suitable for use as system-wide
937 configuration scripts for the following systems:
941 * GDB now supports target-assigned range stepping with remote targets.
942 This improves the performance of stepping source lines by reducing
943 the number of control packets from/to GDB. See "New remote packets"
946 * GDB now understands the element 'tvar' in the XML traceframe info.
947 It has the id of the collected trace state variables.
949 * On S/390 targets that provide the transactional-execution feature,
950 the program interruption transaction diagnostic block (TDB) is now
951 represented as a number of additional "registers" in GDB.
957 The vCont packet supports a new 'r' action, that tells the remote
958 stub to step through an address range itself, without GDB
959 involvemement at each single-step.
961 qXfer:libraries-svr4:read's annex
962 The previously unused annex of the qXfer:libraries-svr4:read packet
963 is now used to support passing an argument list. The remote stub
964 reports support for this argument list to GDB's qSupported query.
965 The defined arguments are "start" and "prev", used to reduce work
966 necessary for library list updating, resulting in significant
969 * New features in the GDB remote stub, GDBserver
971 ** GDBserver now supports target-assisted range stepping. Currently
972 enabled on x86/x86_64 GNU/Linux targets.
974 ** GDBserver now adds element 'tvar' in the XML in the reply to
975 'qXfer:traceframe-info:read'. It has the id of the collected
976 trace state variables.
978 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
981 * New 'z' formatter for printing and examining memory, this displays the
982 value as hexadecimal zero padded on the left to the size of the type.
984 * GDB can now use Windows x64 unwinding data.
986 * The "set remotebaud" command has been replaced by "set serial baud".
987 Similarly, "show remotebaud" has been replaced by "show serial baud".
988 The "set remotebaud" and "show remotebaud" commands are still available
989 to provide backward compatibility with older versions of GDB.
991 *** Changes in GDB 7.6
993 * Target record has been renamed to record-full.
994 Record/replay is now enabled with the "record full" command.
995 This also affects settings that are associated with full record/replay
996 that have been moved from "set/show record" to "set/show record full":
998 set|show record full insn-number-max
999 set|show record full stop-at-limit
1000 set|show record full memory-query
1002 * A new record target "record-btrace" has been added. The new target
1003 uses hardware support to record the control-flow of a process. It
1004 does not support replaying the execution, but it implements the
1005 below new commands for investigating the recorded execution log.
1006 This new recording method can be enabled using:
1010 The "record-btrace" target is only available on Intel Atom processors
1011 and requires a Linux kernel 2.6.32 or later.
1013 * Two new commands have been added for record/replay to give information
1014 about the recorded execution without having to replay the execution.
1015 The commands are only supported by "record btrace".
1017 record instruction-history prints the execution history at
1018 instruction granularity
1020 record function-call-history prints the execution history at
1021 function granularity
1023 * New native configurations
1025 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1026 FreeBSD/powerpc powerpc*-*-freebsd
1027 x86_64/Cygwin x86_64-*-cygwin*
1028 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1032 ARM AArch64 aarch64*-*-elf
1033 ARM AArch64 GNU/Linux aarch64*-*-linux
1034 Lynx 178 PowerPC powerpc-*-lynx*178
1035 x86_64/Cygwin x86_64-*-cygwin*
1036 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1038 * If the configured location of system.gdbinit file (as given by the
1039 --with-system-gdbinit option at configure time) is in the
1040 data-directory (as specified by --with-gdb-datadir at configure
1041 time) or in one of its subdirectories, then GDB will look for the
1042 system-wide init file in the directory specified by the
1043 --data-directory command-line option.
1045 * New command line options:
1047 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1048 other initialization files, unlike -nx which disables all of them.
1050 * Removed command line options
1052 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1055 * The 'ptype' and 'whatis' commands now accept an argument to control
1058 * 'info proc' now works on some core files.
1062 ** Vectors can be created with gdb.Type.vector.
1064 ** Python's atexit.register now works in GDB.
1066 ** Types can be pretty-printed via a Python API.
1068 ** Python 3 is now supported (in addition to Python 2.4 or later)
1070 ** New class gdb.Architecture exposes GDB's internal representation
1071 of architecture in the Python API.
1073 ** New method Frame.architecture returns the gdb.Architecture object
1074 corresponding to the frame's architecture.
1076 * New Python-based convenience functions:
1078 ** $_memeq(buf1, buf2, length)
1079 ** $_streq(str1, str2)
1081 ** $_regex(str, regex)
1083 * The 'cd' command now defaults to using '~' (the home directory) if not
1086 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1087 default for GCC since November 2000.
1089 * The command 'forward-search' can now be abbreviated as 'fo'.
1091 * The command 'info tracepoints' can now display 'installed on target'
1092 or 'not installed on target' for each non-pending location of tracepoint.
1094 * New configure options
1096 --enable-libmcheck/--disable-libmcheck
1097 By default, development versions are built with -lmcheck on hosts
1098 that support it, in order to help track memory corruption issues.
1099 Release versions, on the other hand, are built without -lmcheck
1100 by default. The --enable-libmcheck/--disable-libmcheck configure
1101 options allow the user to override that default.
1102 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1103 This configure option allows the user to build GDB with
1104 libbabeltrace using which GDB can read Common Trace Format data.
1106 * New commands (for set/show, see "New options" below)
1109 Catch signals. This is similar to "handle", but allows commands and
1110 conditions to be attached.
1113 List the BFDs known to GDB.
1115 python-interactive [command]
1117 Start a Python interactive prompt, or evaluate the optional command
1118 and print the result of expressions.
1121 "py" is a new alias for "python".
1123 enable type-printer [name]...
1124 disable type-printer [name]...
1125 Enable or disable type printers.
1129 ** For the Renesas Super-H architecture, the "regs" command has been removed
1130 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1135 set print type methods (on|off)
1136 show print type methods
1137 Control whether method declarations are displayed by "ptype".
1138 The default is to show them.
1140 set print type typedefs (on|off)
1141 show print type typedefs
1142 Control whether typedef definitions are displayed by "ptype".
1143 The default is to show them.
1145 set filename-display basename|relative|absolute
1146 show filename-display
1147 Control the way in which filenames is displayed.
1148 The default is "relative", which preserves previous behavior.
1150 set trace-buffer-size
1151 show trace-buffer-size
1152 Request target to change the size of trace buffer.
1154 set remote trace-buffer-size-packet auto|on|off
1155 show remote trace-buffer-size-packet
1156 Control the use of the remote protocol `QTBuffer:size' packet.
1160 Control display of debugging messages related to ARM AArch64.
1163 set debug coff-pe-read
1164 show debug coff-pe-read
1165 Control display of debugging messages related to reading of COFF/PE
1170 Control display of debugging messages related to Mach-O symbols
1173 set debug notification
1174 show debug notification
1175 Control display of debugging info for async remote notification.
1179 ** Command parameter changes are now notified using new async record
1180 "=cmd-param-changed".
1181 ** Trace frame changes caused by command "tfind" are now notified using
1182 new async record "=traceframe-changed".
1183 ** The creation, deletion and modification of trace state variables
1184 are now notified using new async records "=tsv-created",
1185 "=tsv-deleted" and "=tsv-modified".
1186 ** The start and stop of process record are now notified using new
1187 async record "=record-started" and "=record-stopped".
1188 ** Memory changes are now notified using new async record
1190 ** The data-disassemble command response will include a "fullname" field
1191 containing the absolute file name when source has been requested.
1192 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1193 command, to allow pattern filling of memory areas.
1194 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1195 library load/unload events.
1196 ** The response to breakpoint commands and breakpoint async records
1197 includes an "installed" field containing a boolean state about each
1198 non-pending tracepoint location is whether installed on target or not.
1199 ** Output of the "-trace-status" command includes a "trace-file" field
1200 containing the name of the trace file being examined. This field is
1201 optional, and only present when examining a trace file.
1202 ** The "fullname" field is now always present along with the "file" field,
1203 even if the file cannot be found by GDB.
1205 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1206 You must have the LZMA library available when configuring GDB for this
1207 feature to be enabled. For more information, see:
1208 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1210 * New remote packets
1213 Set the size of trace buffer. The remote stub reports support for this
1214 packet to gdb's qSupported query.
1217 Enable Branch Trace Store (BTS)-based branch tracing for the current
1218 thread. The remote stub reports support for this packet to gdb's
1222 Disable branch tracing for the current thread. The remote stub reports
1223 support for this packet to gdb's qSupported query.
1226 Read the traced branches for the current thread. The remote stub
1227 reports support for this packet to gdb's qSupported query.
1229 *** Changes in GDB 7.5
1231 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1232 for more x32 ABI info.
1234 * GDB now supports access to MIPS DSP registers on Linux targets.
1236 * GDB now supports debugging microMIPS binaries.
1238 * The "info os" command on GNU/Linux can now display information on
1239 several new classes of objects managed by the operating system:
1240 "info os procgroups" lists process groups
1241 "info os files" lists file descriptors
1242 "info os sockets" lists internet-domain sockets
1243 "info os shm" lists shared-memory regions
1244 "info os semaphores" lists semaphores
1245 "info os msg" lists message queues
1246 "info os modules" lists loaded kernel modules
1248 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1249 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1250 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1251 options and inspect the probe arguments using the new $_probe_arg family
1252 of convenience variables. You can obtain more information about SystemTap
1253 in <http://sourceware.org/systemtap/>.
1255 * GDB now supports reversible debugging on ARM, it allows you to
1256 debug basic ARM and THUMB instructions, and provides
1257 record/replay support.
1259 * The option "symbol-reloading" has been deleted as it is no longer used.
1263 ** GDB commands implemented in Python can now be put in command class
1266 ** The "maint set python print-stack on|off" is now deleted.
1268 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1269 apply "flag enum"-style pretty-printing to any enum.
1271 ** gdb.lookup_symbol can now work when there is no current frame.
1273 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1274 the source at which the symbol was defined.
1276 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1277 method 'value'. The former indicates whether the symbol needs a
1278 frame in order to compute its value, and the latter computes the
1281 ** A new method 'referenced_value' on gdb.Value objects which can
1282 dereference pointer as well as C++ reference values.
1284 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1285 which return the global and static blocks (as gdb.Block objects),
1286 of the underlying symbol table, respectively.
1288 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1289 object associated with a PC value.
1291 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1292 of the address range occupied by code for the current source line.
1294 * Go language support.
1295 GDB now supports debugging programs written in the Go programming
1298 * GDBserver now supports stdio connections.
1299 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1301 * The binary "gdbtui" can no longer be built or installed.
1302 Use "gdb -tui" instead.
1304 * GDB will now print "flag" enums specially. A flag enum is one where
1305 all the enumerator values have no bits in common when pairwise
1306 "and"ed. When printing a value whose type is a flag enum, GDB will
1307 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1308 (gdb) print (enum E) 3
1311 * The filename part of a linespec will now match trailing components
1312 of a source file name. For example, "break gcc/expr.c:1000" will
1313 now set a breakpoint in build/gcc/expr.c, but not
1314 build/libcpp/expr.c.
1316 * The "info proc" and "generate-core-file" commands will now also
1317 work on remote targets connected to GDBserver on Linux.
1319 * The command "info catch" has been removed. It has been disabled
1320 since December 2007.
1322 * The "catch exception" and "catch assert" commands now accept
1323 a condition at the end of the command, much like the "break"
1324 command does. For instance:
1326 (gdb) catch exception Constraint_Error if Barrier = True
1328 Previously, it was possible to add a condition to such catchpoints,
1329 but it had to be done as a second step, after the catchpoint had been
1330 created, using the "condition" command.
1332 * The "info static-tracepoint-marker" command will now also work on
1333 native Linux targets with in-process agent.
1335 * GDB can now set breakpoints on inlined functions.
1337 * The .gdb_index section has been updated to include symbols for
1338 inlined functions. GDB will ignore older .gdb_index sections by
1339 default, which could cause symbol files to be loaded more slowly
1340 until their .gdb_index sections can be recreated. The new command
1341 "set use-deprecated-index-sections on" will cause GDB to use any older
1342 .gdb_index sections it finds. This will restore performance, but the
1343 ability to set breakpoints on inlined functions will be lost in symbol
1344 files with older .gdb_index sections.
1346 The .gdb_index section has also been updated to record more information
1347 about each symbol. This speeds up the "info variables", "info functions"
1348 and "info types" commands when used with programs having the .gdb_index
1349 section, as well as speeding up debugging with shared libraries using
1350 the .gdb_index section.
1352 * Ada support for GDB/MI Variable Objects has been added.
1354 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1359 ** New command -info-os is the MI equivalent of "info os".
1361 ** Output logs ("set logging" and related) now include MI output.
1365 ** "set use-deprecated-index-sections on|off"
1366 "show use-deprecated-index-sections on|off"
1367 Controls the use of deprecated .gdb_index sections.
1369 ** "catch load" and "catch unload" can be used to stop when a shared
1370 library is loaded or unloaded, respectively.
1372 ** "enable count" can be used to auto-disable a breakpoint after
1375 ** "info vtbl" can be used to show the virtual method tables for
1376 C++ and Java objects.
1378 ** "explore" and its sub commands "explore value" and "explore type"
1379 can be used to recursively explore values and types of
1380 expressions. These commands are available only if GDB is
1381 configured with '--with-python'.
1383 ** "info auto-load" shows status of all kinds of auto-loaded files,
1384 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1385 sequences of commands files, "info auto-load python-scripts"
1386 shows status of auto-loading Python script files,
1387 "info auto-load local-gdbinit" shows status of loading init file
1388 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1389 status of inferior specific thread debugging shared library loading.
1391 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1392 and "show auto-load-scripts" commands have been deprecated, use their
1393 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1394 and "show auto-load python-scripts" counterparts instead.
1396 ** "dprintf location,format,args..." creates a dynamic printf, which
1397 is basically a breakpoint that does a printf and immediately
1398 resumes your program's execution, so it is like a printf that you
1399 can insert dynamically at runtime instead of at compiletime.
1401 ** "set print symbol"
1403 Controls whether GDB attempts to display the symbol, if any,
1404 corresponding to addresses it prints. This defaults to "on", but
1405 you can set it to "off" to restore GDB's previous behavior.
1407 * Deprecated commands
1409 ** For the Renesas Super-H architecture, the "regs" command has been
1410 deprecated, and "info all-registers" should be used instead.
1414 Renesas RL78 rl78-*-elf
1415 HP OpenVMS ia64 ia64-hp-openvms*
1417 * GDBserver supports evaluation of breakpoint conditions. When
1418 support is advertised by GDBserver, GDB may be told to send the
1419 breakpoint conditions in bytecode form to GDBserver. GDBserver
1420 will only report the breakpoint trigger to GDB when its condition
1425 set mips compression
1426 show mips compression
1427 Select the compressed ISA encoding used in functions that have no symbol
1428 information available. The encoding can be set to either of:
1431 and is updated automatically from ELF file flags if available.
1433 set breakpoint condition-evaluation
1434 show breakpoint condition-evaluation
1435 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1436 GDBserver ("target"). Default option "auto" chooses the most efficient
1438 This option can improve debugger efficiency depending on the speed of the
1442 Disable auto-loading globally.
1445 Show auto-loading setting of all kinds of auto-loaded files.
1447 set auto-load gdb-scripts on|off
1448 show auto-load gdb-scripts
1449 Control auto-loading of GDB canned sequences of commands files.
1451 set auto-load python-scripts on|off
1452 show auto-load python-scripts
1453 Control auto-loading of Python script files.
1455 set auto-load local-gdbinit on|off
1456 show auto-load local-gdbinit
1457 Control loading of init file (.gdbinit) from current directory.
1459 set auto-load libthread-db on|off
1460 show auto-load libthread-db
1461 Control auto-loading of inferior specific thread debugging shared library.
1463 set auto-load scripts-directory <dir1>[:<dir2>...]
1464 show auto-load scripts-directory
1465 Set a list of directories from which to load auto-loaded scripts.
1466 Automatically loaded Python scripts and GDB scripts are located in one
1467 of the directories listed by this option.
1468 The delimiter (':' above) may differ according to the host platform.
1470 set auto-load safe-path <dir1>[:<dir2>...]
1471 show auto-load safe-path
1472 Set a list of directories from which it is safe to auto-load files.
1473 The delimiter (':' above) may differ according to the host platform.
1475 set debug auto-load on|off
1476 show debug auto-load
1477 Control display of debugging info for auto-loading the files above.
1479 set dprintf-style gdb|call|agent
1481 Control the way in which a dynamic printf is performed; "gdb"
1482 requests a GDB printf command, while "call" causes dprintf to call a
1483 function in the inferior. "agent" requests that the target agent
1484 (such as GDBserver) do the printing.
1486 set dprintf-function <expr>
1487 show dprintf-function
1488 set dprintf-channel <expr>
1489 show dprintf-channel
1490 Set the function and optional first argument to the call when using
1491 the "call" style of dynamic printf.
1493 set disconnected-dprintf on|off
1494 show disconnected-dprintf
1495 Control whether agent-style dynamic printfs continue to be in effect
1496 after GDB disconnects.
1498 * New configure options
1500 --with-auto-load-dir
1501 Configure default value for the 'set auto-load scripts-directory'
1502 setting above. It defaults to '$debugdir:$datadir/auto-load',
1503 $debugdir representing global debugging info directories (available
1504 via 'show debug-file-directory') and $datadir representing GDB's data
1505 directory (available via 'show data-directory').
1507 --with-auto-load-safe-path
1508 Configure default value for the 'set auto-load safe-path' setting
1509 above. It defaults to the --with-auto-load-dir setting.
1511 --without-auto-load-safe-path
1512 Set 'set auto-load safe-path' to '/', effectively disabling this
1515 * New remote packets
1517 z0/z1 conditional breakpoints extension
1519 The z0/z1 breakpoint insertion packets have been extended to carry
1520 a list of conditional expressions over to the remote stub depending on the
1521 condition evaluation mode. The use of this extension can be controlled
1522 via the "set remote conditional-breakpoints-packet" command.
1526 Specify the signals which the remote stub may pass to the debugged
1527 program without GDB involvement.
1529 * New command line options
1531 --init-command=FILE, -ix Like --command, -x but execute it
1532 before loading inferior.
1533 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1534 execute it before loading inferior.
1536 *** Changes in GDB 7.4
1538 * GDB now handles ambiguous linespecs more consistently; the existing
1539 FILE:LINE support has been expanded to other types of linespecs. A
1540 breakpoint will now be set on all matching locations in all
1541 inferiors, and locations will be added or removed according to
1544 * GDB now allows you to skip uninteresting functions and files when
1545 stepping with the "skip function" and "skip file" commands.
1547 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1548 and "show remote hardware-watchpoint-length-limit". These allows to
1549 set or show the maximum length limit (in bytes) of a remote
1550 target hardware watchpoint.
1552 This allows e.g. to use "unlimited" hardware watchpoints with the
1553 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1554 watchpoints are slower than real hardware watchpoints but are
1555 significantly faster than gdb software watchpoints.
1559 ** The register_pretty_printer function in module gdb.printing now takes
1560 an optional `replace' argument. If True, the new printer replaces any
1563 ** The "maint set python print-stack on|off" command has been
1564 deprecated and will be deleted in GDB 7.5.
1565 A new command: "set python print-stack none|full|message" has
1566 replaced it. Additionally, the default for "print-stack" is
1567 now "message", which just prints the error message without
1570 ** A prompt substitution hook (prompt_hook) is now available to the
1573 ** A new Python module, gdb.prompt has been added to the GDB Python
1574 modules library. This module provides functionality for
1575 escape sequences in prompts (used by set/show
1576 extended-prompt). These escape sequences are replaced by their
1577 corresponding value.
1579 ** Python commands and convenience-functions located in
1580 'data-directory'/python/gdb/command and
1581 'data-directory'/python/gdb/function are now automatically loaded
1584 ** Blocks now provide four new attributes. global_block and
1585 static_block will return the global and static blocks
1586 respectively. is_static and is_global are boolean attributes
1587 that indicate if the block is one of those two types.
1589 ** Symbols now provide the "type" attribute, the type of the symbol.
1591 ** The "gdb.breakpoint" function has been deprecated in favor of
1594 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1595 of a function. This class is based on the "finish" command
1596 available in the CLI.
1598 ** Type objects for struct and union types now allow access to
1599 the fields using standard Python dictionary (mapping) methods.
1600 For example, "some_type['myfield']" now works, as does
1601 "some_type.items()".
1603 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1606 ** A new function, "deep_items" has been added to the gdb.types
1607 module in the GDB Python modules library. This function returns
1608 an iterator over the fields of a struct or union type. Unlike
1609 the standard Python "iteritems" method, it will recursively traverse
1610 any anonymous fields.
1614 ** "*stopped" events can report several new "reason"s, such as
1617 ** Breakpoint changes are now notified using new async records, like
1618 "=breakpoint-modified".
1620 ** New command -ada-task-info.
1622 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1623 $sdir specifies the default system locations of shared libraries.
1624 $pdir specifies the directory where the libpthread used by the application
1627 GDB no longer looks in $sdir and $pdir after it has searched the directories
1628 mentioned in libthread-db-search-path. If you want to search those
1629 directories, they must be specified in libthread-db-search-path.
1630 The default value of libthread-db-search-path on GNU/Linux and Solaris
1631 systems is now "$sdir:$pdir".
1633 $pdir is not supported by gdbserver, it is currently ignored.
1634 $sdir is supported by gdbserver.
1636 * New configure option --with-iconv-bin.
1637 When using the internationalization support like the one in the GNU C
1638 library, GDB will invoke the "iconv" program to get a list of supported
1639 character sets. If this program lives in a non-standard location, one can
1640 use this option to specify where to find it.
1642 * When natively debugging programs on PowerPC BookE processors running
1643 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1644 watchpoints, which specify a mask in addition to an address to watch.
1645 The mask specifies that some bits of an address (the bits which are
1646 reset in the mask) should be ignored when matching the address accessed
1647 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1648 section in the user manual for more details.
1650 * The new option --once causes GDBserver to stop listening for connections once
1651 the first connection is made. The listening port used by GDBserver will
1652 become available after that.
1654 * New commands "info macros" and "alias" have been added.
1656 * New function parameters suffix @entry specifies value of function parameter
1657 at the time the function got called. Entry values are available only since
1663 "!" is now an alias of the "shell" command.
1664 Note that no space is needed between "!" and SHELL COMMAND.
1668 watch EXPRESSION mask MASK_VALUE
1669 The watch command now supports the mask argument which allows creation
1670 of masked watchpoints, if the current architecture supports this feature.
1672 info auto-load-scripts [REGEXP]
1673 This command was formerly named "maintenance print section-scripts".
1674 It is now generally useful and is no longer a maintenance-only command.
1676 info macro [-all] [--] MACRO
1677 The info macro command has new options `-all' and `--'. The first for
1678 printing all definitions of a macro. The second for explicitly specifying
1679 the end of arguments and the beginning of the macro name in case the macro
1680 name starts with a hyphen.
1682 collect[/s] EXPRESSIONS
1683 The tracepoint collect command now takes an optional modifier "/s"
1684 that directs it to dereference pointer-to-character types and
1685 collect the bytes of memory up to a zero byte. The behavior is
1686 similar to what you see when you use the regular print command on a
1687 string. An optional integer following the "/s" sets a bound on the
1688 number of bytes that will be collected.
1691 The trace start command now interprets any supplied arguments as a
1692 note to be recorded with the trace run, with an effect similar to
1693 setting the variable trace-notes.
1696 The trace stop command now interprets any arguments as a note to be
1697 mentioned along with the tstatus report that the trace was stopped
1698 with a command. The effect is similar to setting the variable
1701 * Tracepoints can now be enabled and disabled at any time after a trace
1702 experiment has been started using the standard "enable" and "disable"
1703 commands. It is now possible to start a trace experiment with no enabled
1704 tracepoints; GDB will display a warning, but will allow the experiment to
1705 begin, assuming that tracepoints will be enabled as needed while the trace
1708 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1709 locations with 4-byte instructions, when they were previously
1710 limited to locations with instructions of 5 bytes or longer.
1714 set debug dwarf2-read
1715 show debug dwarf2-read
1716 Turns on or off display of debugging messages related to reading
1717 DWARF debug info. The default is off.
1719 set debug symtab-create
1720 show debug symtab-create
1721 Turns on or off display of debugging messages related to symbol table
1722 creation. The default is off.
1725 show extended-prompt
1726 Set the GDB prompt, and allow escape sequences to be inserted to
1727 display miscellaneous information (see 'help set extended-prompt'
1728 for the list of sequences). This prompt (and any information
1729 accessed through the escape sequences) is updated every time the
1730 prompt is displayed.
1732 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1733 show print entry-values
1734 Set printing of frame argument values at function entry. In some cases
1735 GDB can determine the value of function argument which was passed by the
1736 function caller, even if the value was modified inside the called function.
1738 set debug entry-values
1739 show debug entry-values
1740 Control display of debugging info for determining frame argument values at
1741 function entry and virtual tail call frames.
1743 set basenames-may-differ
1744 show basenames-may-differ
1745 Set whether a source file may have multiple base names.
1746 (A "base name" is the name of a file with the directory part removed.
1747 Example: The base name of "/home/user/hello.c" is "hello.c".)
1748 If set, GDB will canonicalize file names (e.g., expand symlinks)
1749 before comparing them. Canonicalization is an expensive operation,
1750 but it allows the same file be known by more than one base name.
1751 If not set (the default), all source files are assumed to have just
1752 one base name, and gdb will do file name comparisons more efficiently.
1758 Set a user name and notes for the current and any future trace runs.
1759 This is useful for long-running and/or disconnected traces, to
1760 inform others (or yourself) as to who is running the trace, supply
1761 contact information, or otherwise explain what is going on.
1763 set trace-stop-notes
1764 show trace-stop-notes
1765 Set a note attached to the trace run, that is displayed when the
1766 trace has been stopped by a tstop command. This is useful for
1767 instance as an explanation, if you are stopping a trace run that was
1768 started by someone else.
1770 * New remote packets
1774 Dynamically enable a tracepoint in a started trace experiment.
1778 Dynamically disable a tracepoint in a started trace experiment.
1782 Set the user and notes of the trace run.
1786 Query the current status of a tracepoint.
1790 Query the minimum length of instruction at which a fast tracepoint may
1793 * Dcache size (number of lines) and line-size are now runtime-configurable
1794 via "set dcache line" and "set dcache line-size" commands.
1798 Texas Instruments TMS320C6x tic6x-*-*
1802 Renesas RL78 rl78-*-elf
1804 *** Changes in GDB 7.3.1
1806 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1808 *** Changes in GDB 7.3
1810 * GDB has a new command: "thread find [REGEXP]".
1811 It finds the thread id whose name, target id, or thread extra info
1812 matches the given regular expression.
1814 * The "catch syscall" command now works on mips*-linux* targets.
1816 * The -data-disassemble MI command now supports modes 2 and 3 for
1817 dumping the instruction opcodes.
1819 * New command line options
1821 -data-directory DIR Specify DIR as the "data-directory".
1822 This is mostly for testing purposes.
1824 * The "maint set python auto-load on|off" command has been renamed to
1825 "set auto-load-scripts on|off".
1827 * GDB has a new command: "set directories".
1828 It is like the "dir" command except that it replaces the
1829 source path list instead of augmenting it.
1831 * GDB now understands thread names.
1833 On GNU/Linux, "info threads" will display the thread name as set by
1834 prctl or pthread_setname_np.
1836 There is also a new command, "thread name", which can be used to
1837 assign a name internally for GDB to display.
1840 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1841 has been integrated into GDB.
1845 ** The function gdb.Write now accepts an optional keyword 'stream'.
1846 This keyword, when provided, will direct the output to either
1847 stdout, stderr, or GDB's logging output.
1849 ** Parameters can now be be sub-classed in Python, and in particular
1850 you may implement the get_set_doc and get_show_doc functions.
1851 This improves how Parameter set/show documentation is processed
1852 and allows for more dynamic content.
1854 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1855 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1856 have an is_valid method.
1858 ** Breakpoints can now be sub-classed in Python, and in particular
1859 you may implement a 'stop' function that is executed each time
1860 the inferior reaches that breakpoint.
1862 ** New function gdb.lookup_global_symbol looks up a global symbol.
1864 ** GDB values in Python are now callable if the value represents a
1865 function. For example, if 'some_value' represents a function that
1866 takes two integer parameters and returns a value, you can call
1867 that function like so:
1869 result = some_value (10,20)
1871 ** Module gdb.types has been added.
1872 It contains a collection of utilities for working with gdb.Types objects:
1873 get_basic_type, has_field, make_enum_dict.
1875 ** Module gdb.printing has been added.
1876 It contains utilities for writing and registering pretty-printers.
1877 New classes: PrettyPrinter, SubPrettyPrinter,
1878 RegexpCollectionPrettyPrinter.
1879 New function: register_pretty_printer.
1881 ** New commands "info pretty-printers", "enable pretty-printer" and
1882 "disable pretty-printer" have been added.
1884 ** gdb.parameter("directories") is now available.
1886 ** New function gdb.newest_frame returns the newest frame in the
1889 ** The gdb.InferiorThread class has a new "name" attribute. This
1890 holds the thread's name.
1892 ** Python Support for Inferior events.
1893 Python scripts can add observers to be notified of events
1894 occurring in the process being debugged.
1895 The following events are currently supported:
1896 - gdb.events.cont Continue event.
1897 - gdb.events.exited Inferior exited event.
1898 - gdb.events.stop Signal received, and Breakpoint hit events.
1902 ** GDB now puts template parameters in scope when debugging in an
1903 instantiation. For example, if you have:
1905 template<int X> int func (void) { return X; }
1907 then if you step into func<5>, "print X" will show "5". This
1908 feature requires proper debuginfo support from the compiler; it
1909 was added to GCC 4.5.
1911 ** The motion commands "next", "finish", "until", and "advance" now
1912 work better when exceptions are thrown. In particular, GDB will
1913 no longer lose control of the inferior; instead, the GDB will
1914 stop the inferior at the point at which the exception is caught.
1915 This functionality requires a change in the exception handling
1916 code that was introduced in GCC 4.5.
1918 * GDB now follows GCC's rules on accessing volatile objects when
1919 reading or writing target state during expression evaluation.
1920 One notable difference to prior behavior is that "print x = 0"
1921 no longer generates a read of x; the value of the assignment is
1922 now always taken directly from the value being assigned.
1924 * GDB now has some support for using labels in the program's source in
1925 linespecs. For instance, you can use "advance label" to continue
1926 execution to a label.
1928 * GDB now has support for reading and writing a new .gdb_index
1929 section. This section holds a fast index of DWARF debugging
1930 information and can be used to greatly speed up GDB startup and
1931 operation. See the documentation for `save gdb-index' for details.
1933 * The "watch" command now accepts an optional "-location" argument.
1934 When used, this causes GDB to watch the memory referred to by the
1935 expression. Such a watchpoint is never deleted due to it going out
1938 * GDB now supports thread debugging of core dumps on GNU/Linux.
1940 GDB now activates thread debugging using the libthread_db library
1941 when debugging GNU/Linux core dumps, similarly to when debugging
1942 live processes. As a result, when debugging a core dump file, GDB
1943 is now able to display pthread_t ids of threads. For example, "info
1944 threads" shows the same output as when debugging the process when it
1945 was live. In earlier releases, you'd see something like this:
1948 * 1 LWP 6780 main () at main.c:10
1950 While now you see this:
1953 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1955 It is also now possible to inspect TLS variables when debugging core
1958 When debugging a core dump generated on a machine other than the one
1959 used to run GDB, you may need to point GDB at the correct
1960 libthread_db library with the "set libthread-db-search-path"
1961 command. See the user manual for more details on this command.
1963 * When natively debugging programs on PowerPC BookE processors running
1964 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1965 which stop execution of the inferior whenever it executes an instruction
1966 at any address within the specified range. See the "PowerPC Embedded"
1967 section in the user manual for more details.
1969 * New features in the GDB remote stub, GDBserver
1971 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1972 and i686 LynxOS (version 5.x).
1974 ** GDBserver is now supported on Blackfin Linux.
1976 * New native configurations
1978 ia64 HP-UX ia64-*-hpux*
1982 Analog Devices, Inc. Blackfin Processor bfin-*
1984 * Ada task switching is now supported on sparc-elf targets when
1985 debugging a program using the Ravenscar Profile. For more information,
1986 see the "Tasking Support when using the Ravenscar Profile" section
1987 in the GDB user manual.
1989 * Guile support was removed.
1991 * New features in the GNU simulator
1993 ** The --map-info flag lists all known core mappings.
1995 ** CFI flashes may be simulated via the "cfi" device.
1997 *** Changes in GDB 7.2
1999 * Shared library support for remote targets by default
2001 When GDB is configured for a generic, non-OS specific target, like
2002 for example, --target=arm-eabi or one of the many *-*-elf targets,
2003 GDB now queries remote stubs for loaded shared libraries using the
2004 `qXfer:libraries:read' packet. Previously, shared library support
2005 was always disabled for such configurations.
2009 ** Argument Dependent Lookup (ADL)
2011 In C++ ADL lookup directs function search to the namespaces of its
2012 arguments even if the namespace has not been imported.
2022 Here the compiler will search for `foo' in the namespace of 'b'
2023 and find A::foo. GDB now supports this. This construct is commonly
2024 used in the Standard Template Library for operators.
2026 ** Improved User Defined Operator Support
2028 In addition to member operators, GDB now supports lookup of operators
2029 defined in a namespace and imported with a `using' directive, operators
2030 defined in the global scope, operators imported implicitly from an
2031 anonymous namespace, and the ADL operators mentioned in the previous
2033 GDB now also supports proper overload resolution for all the previously
2034 mentioned flavors of operators.
2036 ** static const class members
2038 Printing of static const class members that are initialized in the
2039 class definition has been fixed.
2041 * Windows Thread Information Block access.
2043 On Windows targets, GDB now supports displaying the Windows Thread
2044 Information Block (TIB) structure. This structure is visible either
2045 by using the new command `info w32 thread-information-block' or, by
2046 dereferencing the new convenience variable named `$_tlb', a
2047 thread-specific pointer to the TIB. This feature is also supported
2048 when remote debugging using GDBserver.
2050 * Static tracepoints
2052 Static tracepoints are calls in the user program into a tracing
2053 library. One such library is a port of the LTTng kernel tracer to
2054 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2055 When debugging with GDBserver, GDB now supports combining the GDB
2056 tracepoint machinery with such libraries. For example: the user can
2057 use GDB to probe a static tracepoint marker (a call from the user
2058 program into the tracing library) with the new "strace" command (see
2059 "New commands" below). This creates a "static tracepoint" in the
2060 breakpoint list, that can be manipulated with the same feature set
2061 as fast and regular tracepoints. E.g., collect registers, local and
2062 global variables, collect trace state variables, and define
2063 tracepoint conditions. In addition, the user can collect extra
2064 static tracepoint marker specific data, by collecting the new
2065 $_sdata internal variable. When analyzing the trace buffer, you can
2066 inspect $_sdata like any other variable available to GDB. For more
2067 information, see the "Tracepoints" chapter in GDB user manual. New
2068 remote packets have been defined to support static tracepoints, see
2069 the "New remote packets" section below.
2071 * Better reconstruction of tracepoints after disconnected tracing
2073 GDB will attempt to download the original source form of tracepoint
2074 definitions when starting a trace run, and then will upload these
2075 upon reconnection to the target, resulting in a more accurate
2076 reconstruction of the tracepoints that are in use on the target.
2080 You can now exercise direct control over the ways that GDB can
2081 affect your program. For instance, you can disallow the setting of
2082 breakpoints, so that the program can run continuously (assuming
2083 non-stop mode). In addition, the "observer" variable is available
2084 to switch all of the different controls; in observer mode, GDB
2085 cannot affect the target's behavior at all, which is useful for
2086 tasks like diagnosing live systems in the field.
2088 * The new convenience variable $_thread holds the number of the
2091 * New remote packets
2095 Return the address of the Windows Thread Information Block of a given thread.
2099 In response to several of the tracepoint packets, the target may now
2100 also respond with a number of intermediate `qRelocInsn' request
2101 packets before the final result packet, to have GDB handle
2102 relocating an instruction to execute at a different address. This
2103 is particularly useful for stubs that support fast tracepoints. GDB
2104 reports support for this feature in the qSupported packet.
2108 List static tracepoint markers in the target program.
2112 List static tracepoint markers at a given address in the target
2115 qXfer:statictrace:read
2117 Read the static trace data collected (by a `collect $_sdata'
2118 tracepoint action). The remote stub reports support for this packet
2119 to gdb's qSupported query.
2123 Send the current settings of GDB's permission flags.
2127 Send part of the source (textual) form of a tracepoint definition,
2128 which includes location, conditional, and action list.
2130 * The source command now accepts a -s option to force searching for the
2131 script in the source search path even if the script name specifies
2134 * New features in the GDB remote stub, GDBserver
2136 - GDBserver now support tracepoints (including fast tracepoints, and
2137 static tracepoints). The feature is currently supported by the
2138 i386-linux and amd64-linux builds. See the "Tracepoints support
2139 in gdbserver" section in the manual for more information.
2141 GDBserver JIT compiles the tracepoint's conditional agent
2142 expression bytecode into native code whenever possible for low
2143 overhead dynamic tracepoints conditionals. For such tracepoints,
2144 an expression that examines program state is evaluated when the
2145 tracepoint is reached, in order to determine whether to capture
2146 trace data. If the condition is simple and false, processing the
2147 tracepoint finishes very quickly and no data is gathered.
2149 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2150 for static tracepoints support.
2152 - GDBserver now supports x86_64 Windows 64-bit debugging.
2154 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2155 it understands register description.
2157 * The --batch flag now disables pagination and queries.
2159 * X86 general purpose registers
2161 GDB now supports reading/writing byte, word and double-word x86
2162 general purpose registers directly. This means you can use, say,
2163 $ah or $ax to refer, respectively, to the byte register AH and
2164 16-bit word register AX that are actually portions of the 32-bit
2165 register EAX or 64-bit register RAX.
2167 * The `commands' command now accepts a range of breakpoints to modify.
2168 A plain `commands' following a command that creates multiple
2169 breakpoints affects all the breakpoints set by that command. This
2170 applies to breakpoints set by `rbreak', and also applies when a
2171 single `break' command creates multiple breakpoints (e.g.,
2172 breakpoints on overloaded c++ functions).
2174 * The `rbreak' command now accepts a filename specification as part of
2175 its argument, limiting the functions selected by the regex to those
2176 in the specified file.
2178 * Support for remote debugging Windows and SymbianOS shared libraries
2179 from Unix hosts has been improved. Non Windows GDB builds now can
2180 understand target reported file names that follow MS-DOS based file
2181 system semantics, such as file names that include drive letters and
2182 use the backslash character as directory separator. This makes it
2183 possible to transparently use the "set sysroot" and "set
2184 solib-search-path" on Unix hosts to point as host copies of the
2185 target's shared libraries. See the new command "set
2186 target-file-system-kind" described below, and the "Commands to
2187 specify files" section in the user manual for more information.
2191 eval template, expressions...
2192 Convert the values of one or more expressions under the control
2193 of the string template to a command line, and call it.
2195 set target-file-system-kind unix|dos-based|auto
2196 show target-file-system-kind
2197 Set or show the assumed file system kind for target reported file
2200 save breakpoints <filename>
2201 Save all current breakpoint definitions to a file suitable for use
2202 in a later debugging session. To read the saved breakpoint
2203 definitions, use the `source' command.
2205 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2208 info static-tracepoint-markers
2209 Display information about static tracepoint markers in the target.
2211 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2212 Define a static tracepoint by probing a marker at the given
2213 function, line, address, or marker ID.
2217 Enable and disable observer mode.
2219 set may-write-registers on|off
2220 set may-write-memory on|off
2221 set may-insert-breakpoints on|off
2222 set may-insert-tracepoints on|off
2223 set may-insert-fast-tracepoints on|off
2224 set may-interrupt on|off
2225 Set individual permissions for GDB effects on the target. Note that
2226 some of these settings can have undesirable or surprising
2227 consequences, particularly when changed in the middle of a session.
2228 For instance, disabling the writing of memory can prevent
2229 breakpoints from being inserted, cause single-stepping to fail, or
2230 even crash your program, if you disable after breakpoints have been
2231 inserted. However, GDB should not crash.
2233 set record memory-query on|off
2234 show record memory-query
2235 Control whether to stop the inferior if memory changes caused
2236 by an instruction cannot be recorded.
2241 The disassemble command now supports "start,+length" form of two arguments.
2245 ** GDB now provides a new directory location, called the python directory,
2246 where Python scripts written for GDB can be installed. The location
2247 of that directory is <data-directory>/python, where <data-directory>
2248 is the GDB data directory. For more details, see section `Scripting
2249 GDB using Python' in the manual.
2251 ** The GDB Python API now has access to breakpoints, symbols, symbol
2252 tables, program spaces, inferiors, threads and frame's code blocks.
2253 Additionally, GDB Parameters can now be created from the API, and
2254 manipulated via set/show in the CLI.
2256 ** New functions gdb.target_charset, gdb.target_wide_charset,
2257 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2259 ** New exception gdb.GdbError.
2261 ** Pretty-printers are now also looked up in the current program space.
2263 ** Pretty-printers can now be individually enabled and disabled.
2265 ** GDB now looks for names of Python scripts to auto-load in a
2266 special section named `.debug_gdb_scripts', in addition to looking
2267 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2269 * Tracepoint actions were unified with breakpoint commands. In particular,
2270 there are no longer differences in "info break" output for breakpoints and
2271 tracepoints and the "commands" command can be used for both tracepoints and
2272 regular breakpoints.
2276 ARM Symbian arm*-*-symbianelf*
2278 * D language support.
2279 GDB now supports debugging programs written in the D programming
2282 * GDB now supports the extended ptrace interface for PowerPC which is
2283 available since Linux kernel version 2.6.34. This automatically enables
2284 any hardware breakpoints and additional hardware watchpoints available in
2285 the processor. The old ptrace interface exposes just one hardware
2286 watchpoint and no hardware breakpoints.
2288 * GDB is now able to use the Data Value Compare (DVC) register available on
2289 embedded PowerPC processors to implement in hardware simple watchpoint
2290 conditions of the form:
2292 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2294 This works in native GDB running on Linux kernels with the extended ptrace
2295 interface mentioned above.
2297 *** Changes in GDB 7.1
2301 ** Namespace Support
2303 GDB now supports importing of namespaces in C++. This enables the
2304 user to inspect variables from imported namespaces. Support for
2305 namepace aliasing has also been added. So, if a namespace is
2306 aliased in the current scope (e.g. namepace C=A; ) the user can
2307 print variables using the alias (e.g. (gdb) print C::x).
2311 All known bugs relating to the printing of virtual base class were
2312 fixed. It is now possible to call overloaded static methods using a
2317 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2318 and reinterpret_cast<> are now handled by the C++ expression parser.
2322 Xilinx MicroBlaze microblaze-*-*
2327 Xilinx MicroBlaze microblaze
2330 * Multi-program debugging.
2332 GDB now has support for multi-program (a.k.a. multi-executable or
2333 multi-exec) debugging. This allows for debugging multiple inferiors
2334 simultaneously each running a different program under the same GDB
2335 session. See "Debugging Multiple Inferiors and Programs" in the
2336 manual for more information. This implied some user visible changes
2337 in the multi-inferior support. For example, "info inferiors" now
2338 lists inferiors that are not running yet or that have exited
2339 already. See also "New commands" and "New options" below.
2341 * New tracing features
2343 GDB's tracepoint facility now includes several new features:
2345 ** Trace state variables
2347 GDB tracepoints now include support for trace state variables, which
2348 are variables managed by the target agent during a tracing
2349 experiment. They are useful for tracepoints that trigger each
2350 other, so for instance one tracepoint can count hits in a variable,
2351 and then a second tracepoint has a condition that is true when the
2352 count reaches a particular value. Trace state variables share the
2353 $-syntax of GDB convenience variables, and can appear in both
2354 tracepoint actions and condition expressions. Use the "tvariable"
2355 command to create, and "info tvariables" to view; see "Trace State
2356 Variables" in the manual for more detail.
2360 GDB now includes an option for defining fast tracepoints, which
2361 targets may implement more efficiently, such as by installing a jump
2362 into the target agent rather than a trap instruction. The resulting
2363 speedup can be by two orders of magnitude or more, although the
2364 tradeoff is that some program locations on some target architectures
2365 might not allow fast tracepoint installation, for instance if the
2366 instruction to be replaced is shorter than the jump. To request a
2367 fast tracepoint, use the "ftrace" command, with syntax identical to
2368 the regular trace command.
2370 ** Disconnected tracing
2372 It is now possible to detach GDB from the target while it is running
2373 a trace experiment, then reconnect later to see how the experiment
2374 is going. In addition, a new variable disconnected-tracing lets you
2375 tell the target agent whether to continue running a trace if the
2376 connection is lost unexpectedly.
2380 GDB now has the ability to save the trace buffer into a file, and
2381 then use that file as a target, similarly to you can do with
2382 corefiles. You can select trace frames, print data that was
2383 collected in them, and use tstatus to display the state of the
2384 tracing run at the moment that it was saved. To create a trace
2385 file, use "tsave <filename>", and to use it, do "target tfile
2388 ** Circular trace buffer
2390 You can ask the target agent to handle the trace buffer as a
2391 circular buffer, discarding the oldest trace frames to make room for
2392 newer ones, by setting circular-trace-buffer to on. This feature may
2393 not be available for all target agents.
2398 The disassemble command, when invoked with two arguments, now requires
2399 the arguments to be comma-separated.
2402 The info variables command now displays variable definitions. Files
2403 which only declare a variable are not shown.
2406 The source command is now capable of sourcing Python scripts.
2407 This feature is dependent on the debugger being build with Python
2410 Related to this enhancement is also the introduction of a new command
2411 "set script-extension" (see below).
2413 * New commands (for set/show, see "New options" below)
2415 record save [<FILENAME>]
2416 Save a file (in core file format) containing the process record
2417 execution log for replay debugging at a later time.
2419 record restore <FILENAME>
2420 Restore the process record execution log that was saved at an
2421 earlier time, for replay debugging.
2423 add-inferior [-copies <N>] [-exec <FILENAME>]
2426 clone-inferior [-copies <N>] [ID]
2427 Make a new inferior ready to execute the same program another
2428 inferior has loaded.
2433 maint info program-spaces
2434 List the program spaces loaded into GDB.
2436 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2437 show remote interrupt-sequence
2438 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2439 as the sequence to the remote target in order to interrupt the execution.
2440 Ctrl-C is a default. Some system prefers BREAK which is high level of
2441 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2442 Magic SysRq g. It is BREAK signal and character 'g'.
2444 set remote interrupt-on-connect [on | off]
2445 show remote interrupt-on-connect
2446 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2447 remote target when gdb connects to it. This is needed when you debug
2450 set remotebreak [on | off]
2452 Deprecated. Use "set/show remote interrupt-sequence" instead.
2454 tvariable $NAME [ = EXP ]
2455 Create or modify a trace state variable.
2458 List trace state variables and their values.
2460 delete tvariable $NAME ...
2461 Delete one or more trace state variables.
2464 Evaluate the given expressions without collecting anything into the
2465 trace buffer. (Valid in tracepoint actions only.)
2467 ftrace FN / FILE:LINE / *ADDR
2468 Define a fast tracepoint at the given function, line, or address.
2470 * New expression syntax
2472 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2473 GDB now parses 0b101010 identically with 42.
2477 set follow-exec-mode new|same
2478 show follow-exec-mode
2479 Control whether GDB reuses the same inferior across an exec call or
2480 creates a new one. This is useful to be able to restart the old
2481 executable after the inferior having done an exec call.
2483 set default-collect EXPR, ...
2484 show default-collect
2485 Define a list of expressions to be collected at each tracepoint.
2486 This is a useful way to ensure essential items are not overlooked,
2487 such as registers or a critical global variable.
2489 set disconnected-tracing
2490 show disconnected-tracing
2491 If set to 1, the target is instructed to continue tracing if it
2492 loses its connection to GDB. If 0, the target is to stop tracing
2495 set circular-trace-buffer
2496 show circular-trace-buffer
2497 If set to on, the target is instructed to use a circular trace buffer
2498 and discard the oldest trace frames instead of stopping the trace due
2499 to a full trace buffer. If set to off, the trace stops when the buffer
2500 fills up. Some targets may not support this.
2502 set script-extension off|soft|strict
2503 show script-extension
2504 If set to "off", the debugger does not perform any script language
2505 recognition, and all sourced files are assumed to be GDB scripts.
2506 If set to "soft" (the default), files are sourced according to
2507 filename extension, falling back to GDB scripts if the first
2509 If set to "strict", files are sourced according to filename extension.
2511 set ada trust-PAD-over-XVS on|off
2512 show ada trust-PAD-over-XVS
2513 If off, activate a workaround against a bug in the debugging information
2514 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2515 the GCC sources for more information about the GNAT encoding and
2516 PAD types in particular). It is always safe to set this option to
2517 off, but this introduces a slight performance penalty. The default
2520 * Python API Improvements
2522 ** GDB provides the new class gdb.LazyString. This is useful in
2523 some pretty-printing cases. The new method gdb.Value.lazy_string
2524 provides a simple way to create objects of this type.
2526 ** The fields returned by gdb.Type.fields now have an
2527 `is_base_class' attribute.
2529 ** The new method gdb.Type.range returns the range of an array type.
2531 ** The new method gdb.parse_and_eval can be used to parse and
2532 evaluate an expression.
2534 * New remote packets
2537 Define a trace state variable.
2540 Get the current value of a trace state variable.
2543 Set desired tracing behavior upon disconnection.
2546 Set the trace buffer to be linear or circular.
2549 Get data about the tracepoints currently in use.
2553 Process record now works correctly with hardware watchpoints.
2555 Multiple bug fixes have been made to the mips-irix port, making it
2556 much more reliable. In particular:
2557 - Debugging threaded applications is now possible again. Previously,
2558 GDB would hang while starting the program, or while waiting for
2559 the program to stop at a breakpoint.
2560 - Attaching to a running process no longer hangs.
2561 - An error occurring while loading a core file has been fixed.
2562 - Changing the value of the PC register now works again. This fixes
2563 problems observed when using the "jump" command, or when calling
2564 a function from GDB, or even when assigning a new value to $pc.
2565 - With the "finish" and "return" commands, the return value for functions
2566 returning a small array is now correctly printed.
2567 - It is now possible to break on shared library code which gets executed
2568 during a shared library init phase (code executed while executing
2569 their .init section). Previously, the breakpoint would have no effect.
2570 - GDB is now able to backtrace through the signal handler for
2571 non-threaded programs.
2573 PIE (Position Independent Executable) programs debugging is now supported.
2574 This includes debugging execution of PIC (Position Independent Code) shared
2575 libraries although for that, it should be possible to run such libraries as an
2578 *** Changes in GDB 7.0
2580 * GDB now has an interface for JIT compilation. Applications that
2581 dynamically generate code can create symbol files in memory and register
2582 them with GDB. For users, the feature should work transparently, and
2583 for JIT developers, the interface is documented in the GDB manual in the
2584 "JIT Compilation Interface" chapter.
2586 * Tracepoints may now be conditional. The syntax is as for
2587 breakpoints; either an "if" clause appended to the "trace" command,
2588 or the "condition" command is available. GDB sends the condition to
2589 the target for evaluation using the same bytecode format as is used
2590 for tracepoint actions.
2592 * The disassemble command now supports: an optional /r modifier, print the
2593 raw instructions in hex as well as in symbolic form, and an optional /m
2594 modifier to print mixed source+assembly.
2596 * Process record and replay
2598 In a architecture environment that supports ``process record and
2599 replay'', ``process record and replay'' target can record a log of
2600 the process execution, and replay it with both forward and reverse
2603 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2604 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2605 set execution-direction {forward|reverse}, for targets that support
2608 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2609 feature is available with a native GDB running on kernel version
2612 * GDB now has support for multi-byte and wide character sets on the
2613 target. Strings whose character type is wchar_t, char16_t, or
2614 char32_t are now correctly printed. GDB supports wide- and unicode-
2615 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2616 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2617 `printf'. This feature requires iconv to work properly; if your
2618 system does not have a working iconv, GDB can use GNU libiconv. See
2619 the installation instructions for more information.
2621 * GDB now supports automatic retrieval of shared library files from
2622 remote targets. To use this feature, specify a system root that begins
2623 with the `remote:' prefix, either via the `set sysroot' command or via
2624 the `--with-sysroot' configure-time option.
2626 * "info sharedlibrary" now takes an optional regex of libraries to show,
2627 and it now reports if a shared library has no debugging information.
2629 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2630 now complete on file names.
2632 * When completing in expressions, gdb will attempt to limit
2633 completions to allowable structure or union fields, where appropriate.
2634 For instance, consider:
2636 # struct example { int f1; double f2; };
2637 # struct example variable;
2640 If the user types TAB at the end of this command line, the available
2641 completions will be "f1" and "f2".
2643 * Inlined functions are now supported. They show up in backtraces, and
2644 the "step", "next", and "finish" commands handle them automatically.
2646 * GDB now supports the token-splicing (##) and stringification (#)
2647 operators when expanding macros. It also supports variable-arity
2650 * GDB now supports inspecting extra signal information, exported by
2651 the new $_siginfo convenience variable. The feature is currently
2652 implemented on linux ARM, i386 and amd64.
2654 * GDB can now display the VFP floating point registers and NEON vector
2655 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2656 can provide these registers (requires Linux 2.6.30 or later). Remote
2657 and simulator targets may also provide them.
2659 * New remote packets
2662 Search memory for a sequence of bytes.
2665 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2666 operation over reliable transport links. Use of this packet is
2667 controlled by the `set remote noack-packet' command.
2670 Kill the process with the specified process ID. Use this in preference
2671 to `k' when multiprocess protocol extensions are supported.
2674 Obtains additional operating system information
2678 Read or write additional signal information.
2680 * Removed remote protocol undocumented extension
2682 An undocumented extension to the remote protocol's `S' stop reply
2683 packet that permited the stub to pass a process id was removed.
2684 Remote servers should use the `T' stop reply packet instead.
2686 * GDB now supports multiple function calling conventions according to the
2687 DWARF-2 DW_AT_calling_convention function attribute.
2689 * The SH target utilizes the aforementioned change to distinguish between gcc
2690 and Renesas calling convention. It also adds the new CLI commands
2691 `set/show sh calling-convention'.
2693 * GDB can now read compressed debug sections, as produced by GNU gold
2694 with the --compress-debug-sections=zlib flag.
2696 * 64-bit core files are now supported on AIX.
2698 * Thread switching is now supported on Tru64.
2700 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2701 which will be allocated using malloc later in program execution.
2703 * The qXfer:libraries:read remote procotol packet now allows passing a
2704 list of section offsets.
2706 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2707 conditions handling signals delivered during attach or thread creation
2708 have also been fixed.
2710 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2711 From the user's standpoint, all unqualified instances of True and False
2712 are treated as the standard definitions, regardless of context.
2714 * GDB now parses C++ symbol and type names more flexibly. For
2717 template<typename T> class C { };
2720 GDB will now correctly handle all of:
2722 ptype C<char const *>
2723 ptype C<char const*>
2724 ptype C<const char *>
2725 ptype C<const char*>
2727 * New features in the GDB remote stub, gdbserver
2729 - The "--wrapper" command-line argument tells gdbserver to use a
2730 wrapper program to launch programs for debugging.
2732 - On PowerPC and S/390 targets, it is now possible to use a single
2733 gdbserver executable to debug both 32-bit and 64-bit programs.
2734 (This requires gdbserver itself to be built as a 64-bit executable.)
2736 - gdbserver uses the new noack protocol mode for TCP connections to
2737 reduce communications latency, if also supported and enabled in GDB.
2739 - Support for the sparc64-linux-gnu target is now included in
2742 - The amd64-linux build of gdbserver now supports debugging both
2743 32-bit and 64-bit programs.
2745 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2746 now support hardware watchpoints, and will use them automatically
2751 GDB now has support for scripting using Python. Whether this is
2752 available is determined at configure time.
2754 New GDB commands can now be written in Python.
2756 * Ada tasking support
2758 Ada tasks can now be inspected in GDB. The following commands have
2762 Print the list of Ada tasks.
2764 Print detailed information about task number N.
2766 Print the task number of the current task.
2768 Switch the context of debugging to task number N.
2770 * Support for user-defined prefixed commands. The "define" command can
2771 add new commands to existing prefixes, e.g. "target".
2773 * Multi-inferior, multi-process debugging.
2775 GDB now has generalized support for multi-inferior debugging. See
2776 "Debugging Multiple Inferiors" in the manual for more information.
2777 Although availability still depends on target support, the command
2778 set is more uniform now. The GNU/Linux specific multi-forks support
2779 has been migrated to this new framework. This implied some user
2780 visible changes; see "New commands" and also "Removed commands"
2783 * Target descriptions can now describe the target OS ABI. See the
2784 "Target Description Format" section in the user manual for more
2787 * Target descriptions can now describe "compatible" architectures
2788 to indicate that the target can execute applications for a different
2789 architecture in addition to those for the main target architecture.
2790 See the "Target Description Format" section in the user manual for
2793 * Multi-architecture debugging.
2795 GDB now includes general supports for debugging applications on
2796 hybrid systems that use more than one single processor architecture
2797 at the same time. Each such hybrid architecture still requires
2798 specific support to be added. The only hybrid architecture supported
2799 in this version of GDB is the Cell Broadband Engine.
2801 * GDB now supports integrated debugging of Cell/B.E. applications that
2802 use both the PPU and SPU architectures. To enable support for hybrid
2803 Cell/B.E. debugging, you need to configure GDB to support both the
2804 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2805 --enable-targets configure option.
2807 * Non-stop mode debugging.
2809 For some targets, GDB now supports an optional mode of operation in
2810 which you can examine stopped threads while other threads continue
2811 to execute freely. This is referred to as non-stop mode, with the
2812 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2813 section in the user manual for more information.
2815 To be able to support remote non-stop debugging, a remote stub needs
2816 to implement the non-stop mode remote protocol extensions, as
2817 described in the "Remote Non-Stop" section of the user manual. The
2818 GDB remote stub, gdbserver, has been adjusted to support these
2819 extensions on linux targets.
2821 * New commands (for set/show, see "New options" below)
2823 catch syscall [NAME(S) | NUMBER(S)]
2824 Catch system calls. Arguments, which should be names of system
2825 calls or their numbers, mean catch only those syscalls. Without
2826 arguments, every syscall will be caught. When the inferior issues
2827 any of the specified syscalls, GDB will stop and announce the system
2828 call, both when it is called and when its call returns. This
2829 feature is currently available with a native GDB running on the
2830 Linux Kernel, under the following architectures: x86, x86_64,
2831 PowerPC and PowerPC64.
2833 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2835 Search memory for a sequence of bytes.
2837 maint set python print-stack
2838 maint show python print-stack
2839 Show a stack trace when an error is encountered in a Python script.
2842 Invoke CODE by passing it to the Python interpreter.
2847 These allow macros to be defined, undefined, and listed
2851 Show operating system information about processes.
2854 List the inferiors currently under GDB's control.
2857 Switch focus to inferior number NUM.
2860 Detach from inferior number NUM.
2863 Kill inferior number NUM.
2867 set spu stop-on-load
2868 show spu stop-on-load
2869 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2871 set spu auto-flush-cache
2872 show spu auto-flush-cache
2873 Control whether to automatically flush the software-managed cache
2874 during Cell/B.E. debugging.
2876 set sh calling-convention
2877 show sh calling-convention
2878 Control the calling convention used when calling SH target functions.
2881 show debug timestamp
2882 Control display of timestamps with GDB debugging output.
2884 set disassemble-next-line
2885 show disassemble-next-line
2886 Control display of disassembled source lines or instructions when
2889 set remote noack-packet
2890 show remote noack-packet
2891 Set/show the use of remote protocol QStartNoAckMode packet. See above
2892 under "New remote packets."
2894 set remote query-attached-packet
2895 show remote query-attached-packet
2896 Control use of remote protocol `qAttached' (query-attached) packet.
2898 set remote read-siginfo-object
2899 show remote read-siginfo-object
2900 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2903 set remote write-siginfo-object
2904 show remote write-siginfo-object
2905 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2908 set remote reverse-continue
2909 show remote reverse-continue
2910 Control use of remote protocol 'bc' (reverse-continue) packet.
2912 set remote reverse-step
2913 show remote reverse-step
2914 Control use of remote protocol 'bs' (reverse-step) packet.
2916 set displaced-stepping
2917 show displaced-stepping
2918 Control displaced stepping mode. Displaced stepping is a way to
2919 single-step over breakpoints without removing them from the debuggee.
2920 Also known as "out-of-line single-stepping".
2923 show debug displaced
2924 Control display of debugging info for displaced stepping.
2926 maint set internal-error
2927 maint show internal-error
2928 Control what GDB does when an internal error is detected.
2930 maint set internal-warning
2931 maint show internal-warning
2932 Control what GDB does when an internal warning is detected.
2937 Use a wrapper program to launch programs for debugging.
2939 set multiple-symbols (all|ask|cancel)
2940 show multiple-symbols
2941 The value of this variable can be changed to adjust the debugger behavior
2942 when an expression or a breakpoint location contains an ambiguous symbol
2943 name (an overloaded function name, for instance).
2945 set breakpoint always-inserted
2946 show breakpoint always-inserted
2947 Keep breakpoints always inserted in the target, as opposed to inserting
2948 them when resuming the target, and removing them when the target stops.
2949 This option can improve debugger performance on slow remote targets.
2951 set arm fallback-mode (arm|thumb|auto)
2952 show arm fallback-mode
2953 set arm force-mode (arm|thumb|auto)
2955 These commands control how ARM GDB determines whether instructions
2956 are ARM or Thumb. The default for both settings is auto, which uses
2957 the current CPSR value for instructions without symbols; previous
2958 versions of GDB behaved as if "set arm fallback-mode arm".
2960 set disable-randomization
2961 show disable-randomization
2962 Standalone programs run with the virtual address space randomization enabled
2963 by default on some platforms. This option keeps the addresses stable across
2964 multiple debugging sessions.
2968 Control whether other threads are stopped or not when some thread hits
2973 Requests that asynchronous execution is enabled in the target, if available.
2974 In this case, it's possible to resume target in the background, and interact
2975 with GDB while the target is running. "show target-async" displays the
2976 current state of asynchronous execution of the target.
2978 set target-wide-charset
2979 show target-wide-charset
2980 The target-wide-charset is the name of the character set that GDB
2981 uses when printing characters whose type is wchar_t.
2983 set tcp auto-retry (on|off)
2985 set tcp connect-timeout
2986 show tcp connect-timeout
2987 These commands allow GDB to retry failed TCP connections to a remote stub
2988 with a specified timeout period; this is useful if the stub is launched
2989 in parallel with GDB but may not be ready to accept connections immediately.
2991 set libthread-db-search-path
2992 show libthread-db-search-path
2993 Control list of directories which GDB will search for appropriate
2996 set schedule-multiple (on|off)
2997 show schedule-multiple
2998 Allow GDB to resume all threads of all processes or only threads of
2999 the current process.
3003 Use more aggressive caching for accesses to the stack. This improves
3004 performance of remote debugging (particularly backtraces) without
3005 affecting correctness.
3007 set interactive-mode (on|off|auto)
3008 show interactive-mode
3009 Control whether GDB runs in interactive mode (on) or not (off).
3010 When in interactive mode, GDB waits for the user to answer all
3011 queries. Otherwise, GDB does not wait and assumes the default
3012 answer. When set to auto (the default), GDB determines which
3013 mode to use based on the stdin settings.
3018 For program forks, this is replaced by the new more generic `info
3019 inferiors' command. To list checkpoints, you can still use the
3020 `info checkpoints' command, which was an alias for the `info forks'
3024 Replaced by the new `inferior' command. To switch between
3025 checkpoints, you can still use the `restart' command, which was an
3026 alias for the `fork' command.
3029 This is removed, since some targets don't have a notion of
3030 processes. To switch between processes, you can still use the
3031 `inferior' command using GDB's own inferior number.
3034 For program forks, this is replaced by the new more generic `kill
3035 inferior' command. To delete a checkpoint, you can still use the
3036 `delete checkpoint' command, which was an alias for the `delete
3040 For program forks, this is replaced by the new more generic `detach
3041 inferior' command. To detach a checkpoint, you can still use the
3042 `detach checkpoint' command, which was an alias for the `detach
3045 * New native configurations
3047 x86/x86_64 Darwin i[34567]86-*-darwin*
3049 x86_64 MinGW x86_64-*-mingw*
3053 Lattice Mico32 lm32-*
3054 x86 DICOS i[34567]86-*-dicos*
3055 x86_64 DICOS x86_64-*-dicos*
3058 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3059 (mingw32ce) debugging.
3065 These commands were actually not implemented on any target.
3067 *** Changes in GDB 6.8
3069 * New native configurations
3071 NetBSD/hppa hppa*-*netbsd*
3072 Xtensa GNU/Linux xtensa*-*-linux*
3076 NetBSD/hppa hppa*-*-netbsd*
3077 Xtensa GNU/Lunux xtensa*-*-linux*
3079 * Change in command line behavior -- corefiles vs. process ids.
3081 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3082 attaching to process NUMBER fails, GDB no longer attempts to open a
3083 core file named NUMBER. Attaching to a program using the -c option
3084 is no longer supported. Instead, use the '-p' or '--pid' options.
3086 * GDB can now be built as a native debugger for debugging Windows x86
3087 (mingw32) Portable Executable (PE) programs.
3089 * Pending breakpoints no longer change their number when their address
3092 * GDB now supports breakpoints with multiple locations,
3093 including breakpoints on C++ constructors, inside C++ templates,
3094 and in inlined functions.
3096 * GDB's ability to debug optimized code has been improved. GDB more
3097 accurately identifies function bodies and lexical blocks that occupy
3098 more than one contiguous range of addresses.
3100 * Target descriptions can now describe registers for PowerPC.
3102 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3103 registers on PowerPC targets.
3105 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3106 targets even when the libthread_db library is not available.
3108 * The GDB remote stub, gdbserver, now supports the new file transfer
3109 commands (remote put, remote get, and remote delete).
3111 * The GDB remote stub, gdbserver, now supports run and attach in
3112 extended-remote mode.
3114 * hppa*64*-*-hpux11* target broken
3115 The debugger is unable to start a program and fails with the following
3116 error: "Error trying to get information about dynamic linker".
3117 The gdb-6.7 release is also affected.
3119 * GDB now supports the --enable-targets= configure option to allow
3120 building a single GDB executable that supports multiple remote
3121 target architectures.
3123 * GDB now supports debugging C and C++ programs which use the
3124 Decimal Floating Point extension. In addition, the PowerPC target
3125 now has a set of pseudo-registers to inspect decimal float values
3126 stored in two consecutive float registers.
3128 * The -break-insert MI command can optionally create pending
3131 * Improved support for debugging Ada
3132 Many improvements to the Ada language support have been made. These
3134 - Better support for Ada2005 interface types
3135 - Improved handling of arrays and slices in general
3136 - Better support for Taft-amendment types
3137 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3139 - Improved command completion in Ada
3142 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3147 set print frame-arguments (all|scalars|none)
3148 show print frame-arguments
3149 The value of this variable can be changed to control which argument
3150 values should be printed by the debugger when displaying a frame.
3155 Transfer files to and from a remote target, and delete remote files.
3162 Transfer files to and from a remote target, and delete remote files.
3164 * New remote packets
3171 Open, close, read, write, and delete files on the remote system.
3174 Attach to an existing process on the remote system, in extended-remote
3178 Run a new process on the remote system, in extended-remote mode.
3180 *** Changes in GDB 6.7
3182 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3183 bfd, libiberty and opcodes, as revealed by static analysis donated by
3184 Coverity, Inc. (http://scan.coverity.com).
3186 * When looking up multiply-defined global symbols, GDB will now prefer the
3187 symbol definition in the current shared library if it was built using the
3188 -Bsymbolic linker option.
3190 * When the Text User Interface (TUI) is not configured, GDB will now
3191 recognize the -tui command-line option and print a message that the TUI
3194 * The GDB remote stub, gdbserver, now has lower overhead for high
3195 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3197 * GDB for MIPS targets now autodetects whether a remote target provides
3198 32-bit or 64-bit register values.
3200 * Support for C++ member pointers has been improved.
3202 * GDB now understands XML target descriptions, which specify the
3203 target's overall architecture. GDB can read a description from
3204 a local file or over the remote serial protocol.
3206 * Vectors of single-byte data use a new integer type which is not
3207 automatically displayed as character or string data.
3209 * The /s format now works with the print command. It displays
3210 arrays of single-byte integers and pointers to single-byte integers
3213 * Target descriptions can now describe target-specific registers,
3214 for architectures which have implemented the support (currently
3215 only ARM, M68K, and MIPS).
3217 * GDB and the GDB remote stub, gdbserver, now support the XScale
3220 * The GDB remote stub, gdbserver, has been updated to support
3221 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3222 has been rewritten to use the standard GDB remote protocol.
3224 * GDB can now step into C++ functions which are called through thunks.
3226 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3228 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3229 layout. It also supports a TextSeg= and DataSeg= response when only
3230 segment base addresses (rather than offsets) are available.
3232 * The /i format now outputs any trailing branch delay slot instructions
3233 immediately following the last instruction within the count specified.
3235 * The GDB remote protocol "T" stop reply packet now supports a
3236 "library" response. Combined with the new "qXfer:libraries:read"
3237 packet, this response allows GDB to debug shared libraries on targets
3238 where the operating system manages the list of loaded libraries (e.g.
3239 Windows and SymbianOS).
3241 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3242 (DLLs) on Windows and Windows CE targets.
3244 * GDB now supports a faster verification that a .debug file matches its binary
3245 according to its build-id signature, if the signature is present.
3251 Enable or disable hardware flow control (RTS/CTS) on the serial port
3252 when debugging using remote targets.
3254 set mem inaccessible-by-default
3255 show mem inaccessible-by-default
3256 If the target supplies a memory map, for instance via the remote
3257 protocol's "qXfer:memory-map:read" packet, setting this variable
3258 prevents GDB from accessing memory outside the memory map. This
3259 is useful for targets with memory mapped registers or which react
3260 badly to accesses of unmapped address space.
3262 set breakpoint auto-hw
3263 show breakpoint auto-hw
3264 If the target supplies a memory map, for instance via the remote
3265 protocol's "qXfer:memory-map:read" packet, setting this variable
3266 lets GDB use hardware breakpoints automatically for memory regions
3267 where it can not use software breakpoints. This covers both the
3268 "break" command and internal breakpoints used for other commands
3269 including "next" and "finish".
3272 catch exception unhandled
3273 Stop the program execution when Ada exceptions are raised.
3276 Stop the program execution when an Ada assertion failed.
3280 Set an alternate system root for target files. This is a more
3281 general version of "set solib-absolute-prefix", which is now
3282 an alias to "set sysroot".
3285 Provide extended SPU facility status information. This set of
3286 commands is available only when debugging the Cell/B.E. SPU
3289 * New native configurations
3291 OpenBSD/sh sh*-*openbsd*
3294 unset tdesc filename
3296 Use the specified local file as an XML target description, and do
3297 not query the target for its built-in description.
3301 OpenBSD/sh sh*-*-openbsd*
3302 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3303 Toshiba Media Processor mep-elf
3305 * New remote packets
3308 Ignore the specified signals; pass them directly to the debugged program
3309 without stopping other threads or reporting them to GDB.
3311 qXfer:features:read:
3312 Read an XML target description from the target, which describes its
3317 Read or write contents of an spufs file on the target system. These
3318 packets are available only on the Cell/B.E. SPU architecture.
3320 qXfer:libraries:read:
3321 Report the loaded shared libraries. Combined with new "T" packet
3322 response, this packet allows GDB to debug shared libraries on
3323 targets where the operating system manages the list of loaded
3324 libraries (e.g. Windows and SymbianOS).
3328 Support for these obsolete configurations has been removed.
3336 i[34567]86-*-lynxos*
3337 i[34567]86-*-netware*
3338 i[34567]86-*-sco3.2v5*
3339 i[34567]86-*-sco3.2v4*
3341 i[34567]86-*-sysv4.2*
3344 i[34567]86-*-unixware2*
3345 i[34567]86-*-unixware*
3354 * Other removed features
3361 Various m68k-only ROM monitors.
3368 Various Renesas ROM monitors and debugging interfaces for SH and
3373 Support for a Macraigor serial interface to on-chip debugging.
3374 GDB does not directly support the newer parallel or USB
3379 A debug information format. The predecessor to DWARF 2 and
3380 DWARF 3, which are still supported.
3382 Support for the HP aCC compiler on HP-UX/PA-RISC
3384 SOM-encapsulated symbolic debugging information, automatic
3385 invocation of pxdb, and the aCC custom C++ ABI. This does not
3386 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3387 with aCC can still be debugged on an assembly level.
3389 MIPS ".pdr" sections
3391 A MIPS-specific format used to describe stack frame layout
3392 in debugging information.
3396 GDB could work with an older version of Guile to debug
3397 the interpreter and Scheme programs running in it.
3399 set mips stack-arg-size
3400 set mips saved-gpreg-size
3402 Use "set mips abi" to control parameter passing for MIPS.
3404 *** Changes in GDB 6.6
3409 Cell Broadband Engine SPU spu-elf
3411 * GDB can now be configured as a cross-debugger targeting native Windows
3412 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3413 running on a Windows system over TCP/IP to debug Windows programs.
3415 * The GDB remote stub, gdbserver, has been updated to support Windows and
3416 Cygwin debugging. Both single-threaded and multi-threaded programs are
3419 * The "set trust-readonly-sections" command works again. This command was
3420 broken in GDB 6.3, 6.4, and 6.5.
3422 * The "load" command now supports writing to flash memory, if the remote
3423 stub provides the required support.
3425 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3426 longer requires symbolic debug information (e.g. DWARF-2).
3431 unset substitute-path
3432 show substitute-path
3433 Manage a list of substitution rules that GDB uses to rewrite the name
3434 of the directories where the sources are located. This can be useful
3435 for instance when the sources were moved to a different location
3436 between compilation and debugging.
3440 Print each CLI command as it is executed. Each command is prefixed with
3441 a number of `+' symbols representing the nesting depth.
3442 The source command now has a `-v' option to enable the same feature.
3446 The ARM Demon monitor support (RDP protocol, "target rdp").
3448 Kernel Object Display, an embedded debugging feature which only worked with
3449 an obsolete version of Cisco IOS.
3451 The 'set download-write-size' and 'show download-write-size' commands.
3453 * New remote packets
3456 Tell a stub about GDB client features, and request remote target features.
3457 The first feature implemented is PacketSize, which allows the target to
3458 specify the size of packets it can handle - to minimize the number of
3459 packets required and improve performance when connected to a remote
3463 Fetch an OS auxilliary vector from the remote stub. This packet is a
3464 more efficient replacement for qPart:auxv:read.
3466 qXfer:memory-map:read:
3467 Fetch a memory map from the remote stub, including information about
3468 RAM, ROM, and flash memory devices.
3473 Erase and program a flash memory device.
3475 * Removed remote packets
3478 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3479 used it, and only gdbserver implemented it.
3481 *** Changes in GDB 6.5
3485 Renesas M32C/M16C m32c-elf
3487 Morpho Technologies ms1 ms1-elf
3491 init-if-undefined Initialize a convenience variable, but
3492 only if it doesn't already have a value.
3494 The following commands are presently only implemented for native GNU/Linux:
3496 checkpoint Save a snapshot of the program state.
3498 restart <n> Return the program state to a
3499 previously saved state.
3501 info checkpoints List currently saved checkpoints.
3503 delete-checkpoint <n> Delete a previously saved checkpoint.
3505 set|show detach-on-fork Tell gdb whether to detach from a newly
3506 forked process, or to keep debugging it.
3508 info forks List forks of the user program that
3509 are available to be debugged.
3511 fork <n> Switch to debugging one of several
3512 forks of the user program that are
3513 available to be debugged.
3515 delete-fork <n> Delete a fork from the list of forks
3516 that are available to be debugged (and
3517 kill the forked process).
3519 detach-fork <n> Delete a fork from the list of forks
3520 that are available to be debugged (and
3521 allow the process to continue).
3525 Morpho Technologies ms2 ms1-elf
3527 * Improved Windows host support
3529 GDB now builds as a cross debugger hosted on i686-mingw32, including
3530 native console support, and remote communications using either
3531 network sockets or serial ports.
3533 * Improved Modula-2 language support
3535 GDB can now print most types in the Modula-2 syntax. This includes:
3536 basic types, set types, record types, enumerated types, range types,
3537 pointer types and ARRAY types. Procedure var parameters are correctly
3538 printed and hexadecimal addresses and character constants are also
3539 written in the Modula-2 syntax. Best results can be obtained by using
3540 GNU Modula-2 together with the -gdwarf-2 command line option.
3544 The ARM rdi-share module.
3546 The Netware NLM debug server.
3548 *** Changes in GDB 6.4
3550 * New native configurations
3552 OpenBSD/arm arm*-*-openbsd*
3553 OpenBSD/mips64 mips64-*-openbsd*
3557 Morpho Technologies ms1 ms1-elf
3559 * New command line options
3561 --batch-silent As for --batch, but totally silent.
3562 --return-child-result The debugger will exist with the same value
3563 the child (debugged) program exited with.
3564 --eval-command COMMAND, -ex COMMAND
3565 Execute a single GDB CLI command. This may be
3566 specified multiple times and in conjunction
3567 with the --command (-x) option.
3569 * Deprecated commands removed
3571 The following commands, that were deprecated in 2000, have been
3575 set|show arm disassembly-flavor set|show arm disassembler
3576 othernames set arm disassembler
3577 set|show remotedebug set|show debug remote
3578 set|show archdebug set|show debug arch
3579 set|show eventdebug set|show debug event
3582 * New BSD user-level threads support
3584 It is now possible to debug programs using the user-level threads
3585 library on OpenBSD and FreeBSD. Currently supported (target)
3588 FreeBSD/amd64 x86_64-*-freebsd*
3589 FreeBSD/i386 i386-*-freebsd*
3590 OpenBSD/i386 i386-*-openbsd*
3592 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3593 are not yet supported.
3595 * New support for Matsushita MN10300 w/sim added
3596 (Work in progress). mn10300-elf.
3598 * REMOVED configurations and files
3600 VxWorks and the XDR protocol *-*-vxworks
3601 Motorola MCORE mcore-*-*
3602 National Semiconductor NS32000 ns32k-*-*
3604 * New "set print array-indexes" command
3606 After turning this setting "on", GDB prints the index of each element
3607 when displaying arrays. The default is "off" to preserve the previous
3610 * VAX floating point support
3612 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3614 * User-defined command support
3616 In addition to using $arg0..$arg9 for argument passing, it is now possible
3617 to use $argc to determine now many arguments have been passed. See the
3618 section on user-defined commands in the user manual for more information.
3620 *** Changes in GDB 6.3:
3622 * New command line option
3624 GDB now accepts -l followed by a number to set the timeout for remote
3627 * GDB works with GCC -feliminate-dwarf2-dups
3629 GDB now supports a more compact representation of DWARF-2 debug
3630 information using DW_FORM_ref_addr references. These are produced
3631 by GCC with the option -feliminate-dwarf2-dups and also by some
3632 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3633 to use -feliminate-dwarf2-dups.
3635 * Internationalization
3637 When supported by the host system, GDB will be built with
3638 internationalization (libintl). The task of marking up the sources is
3639 continued, we're looking forward to our first translation.
3643 Initial support for debugging programs compiled with the GNAT
3644 implementation of the Ada programming language has been integrated
3645 into GDB. In this release, support is limited to expression evaluation.
3647 * New native configurations
3649 GNU/Linux/m32r m32r-*-linux-gnu
3653 GDB's remote protocol now includes support for the 'p' packet. This
3654 packet is used to fetch individual registers from a remote inferior.
3656 * END-OF-LIFE registers[] compatibility module
3658 GDB's internal register infrastructure has been completely rewritten.
3659 The new infrastructure making possible the implementation of key new
3660 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3663 GDB 6.3 will be the last release to include the the registers[]
3664 compatibility module that allowed out-of-date configurations to
3665 continue to work. This change directly impacts the following
3675 powerpc bdm protocol
3677 Unless there is activity to revive these configurations, they will be
3678 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3680 * OBSOLETE configurations and files
3682 Configurations that have been declared obsolete in this release have
3683 been commented out. Unless there is activity to revive these
3684 configurations, the next release of GDB will have their sources
3685 permanently REMOVED.
3694 *** Changes in GDB 6.2.1:
3696 * MIPS `break main; run' gave an heuristic-fence-post warning
3698 When attempting to run even a simple program, a warning about
3699 heuristic-fence-post being hit would be reported. This problem has
3702 * MIPS IRIX 'long double' crashed GDB
3704 When examining a long double variable, GDB would get a segmentation
3705 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3706 IRIX long double values).
3710 A bug in the VAX stack code was causing problems with the "next"
3711 command. This problem has been fixed.
3713 *** Changes in GDB 6.2:
3715 * Fix for ``many threads''
3717 On GNU/Linux systems that use the NPTL threads library, a program
3718 rapidly creating and deleting threads would confuse GDB leading to the
3721 ptrace: No such process.
3722 thread_db_get_info: cannot get thread info: generic error
3724 This problem has been fixed.
3726 * "-async" and "-noasync" options removed.
3728 Support for the broken "-noasync" option has been removed (it caused
3731 * New ``start'' command.
3733 This command runs the program until the begining of the main procedure.
3735 * New BSD Kernel Data Access Library (libkvm) interface
3737 Using ``target kvm'' it is now possible to debug kernel core dumps and
3738 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3739 platforms. Currently supported (native-only) configurations are:
3741 FreeBSD/amd64 x86_64-*-freebsd*
3742 FreeBSD/i386 i?86-*-freebsd*
3743 NetBSD/i386 i?86-*-netbsd*
3744 NetBSD/m68k m68*-*-netbsd*
3745 NetBSD/sparc sparc-*-netbsd*
3746 OpenBSD/amd64 x86_64-*-openbsd*
3747 OpenBSD/i386 i?86-*-openbsd*
3748 OpenBSD/m68k m68*-openbsd*
3749 OpenBSD/sparc sparc-*-openbsd*
3751 * Signal trampoline code overhauled
3753 Many generic problems with GDB's signal handling code have been fixed.
3754 These include: backtraces through non-contiguous stacks; recognition
3755 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3756 call; backtrace through a signal trampoline; step into and out of
3757 signal handlers; and single-stepping in the signal trampoline.
3759 Please note that kernel bugs are a limiting factor here. These
3760 features have been shown to work on an s390 GNU/Linux system that
3761 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3763 * Cygwin support for DWARF 2 added.
3765 * New native configurations
3767 GNU/Linux/hppa hppa*-*-linux*
3768 OpenBSD/hppa hppa*-*-openbsd*
3769 OpenBSD/m68k m68*-*-openbsd*
3770 OpenBSD/m88k m88*-*-openbsd*
3771 OpenBSD/powerpc powerpc-*-openbsd*
3772 NetBSD/vax vax-*-netbsd*
3773 OpenBSD/vax vax-*-openbsd*
3775 * END-OF-LIFE frame compatibility module
3777 GDB's internal frame infrastructure has been completely rewritten.
3778 The new infrastructure making it possible to support key new features
3779 including DWARF 2 Call Frame Information. To aid in the task of
3780 migrating old configurations to this new infrastructure, a
3781 compatibility module, that allowed old configurations to continue to
3782 work, was also included.
3784 GDB 6.2 will be the last release to include this frame compatibility
3785 module. This change directly impacts the following configurations:
3795 Unless there is activity to revive these configurations, they will be
3796 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3798 * REMOVED configurations and files
3800 Sun 3, running SunOS 3 m68*-*-sunos3*
3801 Sun 3, running SunOS 4 m68*-*-sunos4*
3802 Sun 2, running SunOS 3 m68000-*-sunos3*
3803 Sun 2, running SunOS 4 m68000-*-sunos4*
3804 Motorola 680x0 running LynxOS m68*-*-lynxos*
3805 AT&T 3b1/Unix pc m68*-att-*
3806 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3807 decstation mips-dec-* mips-little-*
3808 riscos mips-*-riscos* mips-*-sysv*
3809 sonymips mips-sony-*
3810 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3812 *** Changes in GDB 6.1.1:
3814 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3816 The TUI (Text-mode User Interface) is now built as part of a default
3817 GDB configuration. It is enabled by either selecting the TUI with the
3818 command line option "-i=tui" or by running the separate "gdbtui"
3819 program. For more information on the TUI, see the manual "Debugging
3822 * Pending breakpoint support (also included in GDB 6.1)
3824 Support has been added to allow you to specify breakpoints in shared
3825 libraries that have not yet been loaded. If a breakpoint location
3826 cannot be found, and the "breakpoint pending" option is set to auto,
3827 GDB queries you if you wish to make the breakpoint pending on a future
3828 shared-library load. If and when GDB resolves the breakpoint symbol,
3829 the pending breakpoint is removed as one or more regular breakpoints
3832 Pending breakpoints are very useful for GCJ Java debugging.
3834 * Fixed ISO-C build problems
3836 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3837 non ISO-C code that stopped them being built using a more strict ISO-C
3838 compiler (e.g., IBM's C compiler).
3840 * Fixed build problem on IRIX 5
3842 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3843 wasn't able to compile compile on an IRIX 5 system.
3845 * Added execute permission to gdb/gdbserver/configure
3847 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3848 permission. This bug would cause configure to fail on a number of
3849 systems (Solaris, IRIX). Ref: server/519.
3851 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3853 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3854 has been updated to use constant array sizes.
3856 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3858 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3859 its generated DWARF Call Frame Info. This encoding was causing GDB to
3860 panic, that panic has been fixed. Ref: gdb/1628.
3862 * Fixed a problem when examining parameters in shared library code.
3864 When examining parameters in optimized shared library code generated
3865 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3866 not available''. GDB now correctly displays the variable's value.
3868 *** Changes in GDB 6.1:
3870 * Removed --with-mmalloc
3872 Support for the mmalloc memory manager has been removed, as it
3873 conflicted with the internal gdb byte cache.
3875 * Changes in AMD64 configurations
3877 The AMD64 target now includes the %cs and %ss registers. As a result
3878 the AMD64 remote protocol has changed; this affects the floating-point
3879 and SSE registers. If you rely on those registers for your debugging,
3880 you should upgrade gdbserver on the remote side.
3882 * Revised SPARC target
3884 The SPARC target has been completely revised, incorporating the
3885 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3886 support for LynxOS and SunOS 4 has been dropped. Calling functions
3887 from within GDB on operating systems with a non-executable stack
3888 (Solaris, OpenBSD) now works.
3892 GDB has a new C++ demangler which does a better job on the mangled
3893 names generated by current versions of g++. It also runs faster, so
3894 with this and other changes gdb should now start faster on large C++
3897 * DWARF 2 Location Expressions
3899 GDB support for location expressions has been extended to support function
3900 arguments and frame bases. Older versions of GDB could crash when they
3903 * C++ nested types and namespaces
3905 GDB's support for nested types and namespaces in C++ has been
3906 improved, especially if you use the DWARF 2 debugging format. (This
3907 is the default for recent versions of GCC on most platforms.)
3908 Specifically, if you have a class "Inner" defined within a class or
3909 namespace "Outer", then GDB realizes that the class's name is
3910 "Outer::Inner", not simply "Inner". This should greatly reduce the
3911 frequency of complaints about not finding RTTI symbols. In addition,
3912 if you are stopped at inside of a function defined within a namespace,
3913 GDB modifies its name lookup accordingly.
3915 * New native configurations
3917 NetBSD/amd64 x86_64-*-netbsd*
3918 OpenBSD/amd64 x86_64-*-openbsd*
3919 OpenBSD/alpha alpha*-*-openbsd*
3920 OpenBSD/sparc sparc-*-openbsd*
3921 OpenBSD/sparc64 sparc64-*-openbsd*
3923 * New debugging protocols
3925 M32R with SDI protocol m32r-*-elf*
3927 * "set prompt-escape-char" command deleted.
3929 The command "set prompt-escape-char" has been deleted. This command,
3930 and its very obscure effet on GDB's prompt, was never documented,
3931 tested, nor mentioned in the NEWS file.
3933 * OBSOLETE configurations and files
3935 Configurations that have been declared obsolete in this release have
3936 been commented out. Unless there is activity to revive these
3937 configurations, the next release of GDB will have their sources
3938 permanently REMOVED.
3940 Sun 3, running SunOS 3 m68*-*-sunos3*
3941 Sun 3, running SunOS 4 m68*-*-sunos4*
3942 Sun 2, running SunOS 3 m68000-*-sunos3*
3943 Sun 2, running SunOS 4 m68000-*-sunos4*
3944 Motorola 680x0 running LynxOS m68*-*-lynxos*
3945 AT&T 3b1/Unix pc m68*-att-*
3946 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3947 decstation mips-dec-* mips-little-*
3948 riscos mips-*-riscos* mips-*-sysv*
3949 sonymips mips-sony-*
3950 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3952 * REMOVED configurations and files
3954 SGI Irix-4.x mips-sgi-irix4 or iris4
3955 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3956 Z8000 simulator z8k-zilog-none or z8ksim
3957 Matsushita MN10200 w/simulator mn10200-*-*
3958 H8/500 simulator h8500-hitachi-hms or h8500hms
3959 HP/PA running BSD hppa*-*-bsd*
3960 HP/PA running OSF/1 hppa*-*-osf*
3961 HP/PA Pro target hppa*-*-pro*
3962 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3963 386BSD i[3456]86-*-bsd*
3964 Sequent family i[3456]86-sequent-sysv4*
3965 i[3456]86-sequent-sysv*
3966 i[3456]86-sequent-bsd*
3967 SPARC running LynxOS sparc-*-lynxos*
3968 SPARC running SunOS 4 sparc-*-sunos4*
3969 Tsqware Sparclet sparclet-*-*
3970 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3972 *** Changes in GDB 6.0:
3976 Support for debugging the Objective-C programming language has been
3977 integrated into GDB.
3979 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3981 DWARF 2's Call Frame Information makes available compiler generated
3982 information that more exactly describes the program's run-time stack.
3983 By using this information, GDB is able to provide more robust stack
3986 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3987 have been updated to use a new backtrace mechanism which includes
3988 DWARF 2 CFI support.
3992 GDB's remote protocol has been extended to include support for hosted
3993 file I/O (where the remote target uses GDB's file system). See GDB's
3994 remote protocol documentation for details.
3996 * All targets using the new architecture framework.
3998 All of GDB's targets have been updated to use the new internal
3999 architecture framework. The way is now open for future GDB releases
4000 to include cross-architecture native debugging support (i386 on amd64,
4003 * GNU/Linux's Thread Local Storage (TLS)
4005 GDB now includes support for for the GNU/Linux implementation of
4006 per-thread variables.
4008 * GNU/Linux's Native POSIX Thread Library (NPTL)
4010 GDB's thread code has been updated to work with either the new
4011 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4013 * Separate debug info.
4015 GDB, in conjunction with BINUTILS, now supports a mechanism for
4016 automatically loading debug information from a separate file. Instead
4017 of shipping full debug and non-debug versions of system libraries,
4018 system integrators can now instead ship just the stripped libraries
4019 and optional debug files.
4021 * DWARF 2 Location Expressions
4023 DWARF 2 Location Expressions allow the compiler to more completely
4024 describe the location of variables (even in optimized code) to the
4027 GDB now includes preliminary support for location expressions (support
4028 for DW_OP_piece is still missing).
4032 A number of long standing bugs that caused GDB to die while starting a
4033 Java application have been fixed. GDB's Java support is now
4034 considered "useable".
4036 * GNU/Linux support for fork, vfork, and exec.
4038 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4039 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4042 * GDB supports logging output to a file
4044 There are two new commands, "set logging" and "show logging", which can be
4045 used to capture GDB's output to a file.
4047 * The meaning of "detach" has changed for gdbserver
4049 The "detach" command will now resume the application, as documented. To
4050 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4053 * d10v, m68hc11 `regs' command deprecated
4055 The `info registers' command has been updated so that it displays the
4056 registers using a format identical to the old `regs' command.
4060 A new command, "maint set profile on/off", has been added. This command can
4061 be used to enable or disable profiling while running GDB, to profile a
4062 session or a set of commands. In addition there is a new configure switch,
4063 "--enable-profiling", which will cause GDB to be compiled with profiling
4064 data, for more informative profiling results.
4066 * Default MI syntax changed to "mi2".
4068 The default MI (machine interface) syntax, enabled by the command line
4069 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4070 "mi1", can be enabled by specifying the option "-i=mi1".
4072 Support for the original "mi0" syntax (included in GDB 5.0) has been
4075 Fix for gdb/192: removed extraneous space when displaying frame level.
4076 Fix for gdb/672: update changelist is now output in mi list format.
4077 Fix for gdb/702: a -var-assign that updates the value now shows up
4078 in a subsequent -var-update.
4080 * New native configurations.
4082 FreeBSD/amd64 x86_64-*-freebsd*
4084 * Multi-arched targets.
4086 HP/PA HPUX11 hppa*-*-hpux*
4087 Renesas M32R/D w/simulator m32r-*-elf*
4089 * OBSOLETE configurations and files
4091 Configurations that have been declared obsolete in this release have
4092 been commented out. Unless there is activity to revive these
4093 configurations, the next release of GDB will have their sources
4094 permanently REMOVED.
4096 Z8000 simulator z8k-zilog-none or z8ksim
4097 Matsushita MN10200 w/simulator mn10200-*-*
4098 H8/500 simulator h8500-hitachi-hms or h8500hms
4099 HP/PA running BSD hppa*-*-bsd*
4100 HP/PA running OSF/1 hppa*-*-osf*
4101 HP/PA Pro target hppa*-*-pro*
4102 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4103 Sequent family i[3456]86-sequent-sysv4*
4104 i[3456]86-sequent-sysv*
4105 i[3456]86-sequent-bsd*
4106 Tsqware Sparclet sparclet-*-*
4107 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4109 * REMOVED configurations and files
4112 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4113 IBM AIX PS/2 i[3456]86-*-aix
4114 i386 running Mach 3.0 i[3456]86-*-mach3*
4115 i386 running Mach i[3456]86-*-mach*
4116 i386 running OSF/1 i[3456]86-*osf1mk*
4117 HP/Apollo 68k Family m68*-apollo*-sysv*,
4119 m68*-hp-bsd*, m68*-hp-hpux*
4120 Argonaut Risc Chip (ARC) arc-*-*
4121 Mitsubishi D30V d30v-*-*
4122 Fujitsu FR30 fr30-*-elf*
4123 OS/9000 i[34]86-*-os9k
4124 I960 with MON960 i960-*-coff
4126 * MIPS $fp behavior changed
4128 The convenience variable $fp, for the MIPS, now consistently returns
4129 the address of the current frame's base. Previously, depending on the
4130 context, $fp could refer to either $sp or the current frame's base
4131 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4132 The GNU Source-Level Debugger''.
4134 *** Changes in GDB 5.3:
4136 * GNU/Linux shared library multi-threaded performance improved.
4138 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4139 `/proc', in preference to `ptrace' for memory reads. This may result
4140 in an improvement in the start-up time of multi-threaded, shared
4141 library applications when run under GDB. One GDB user writes: ``loads
4142 shared libs like mad''.
4144 * ``gdbserver'' now supports multi-threaded applications on some targets
4146 Support for debugging multi-threaded applications which use
4147 the GNU/Linux LinuxThreads package has been added for
4148 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4149 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4151 * GDB now supports C/C++ preprocessor macros.
4153 GDB now expands preprocessor macro invocations in C/C++ expressions,
4154 and provides various commands for showing macro definitions and how
4157 The new command `macro expand EXPRESSION' expands any macro
4158 invocations in expression, and shows the result.
4160 The new command `show macro MACRO-NAME' shows the definition of the
4161 macro named MACRO-NAME, and where it was defined.
4163 Most compilers don't include information about macros in the debugging
4164 information by default. In GCC 3.1, for example, you need to compile
4165 your program with the options `-gdwarf-2 -g3'. If the macro
4166 information is present in the executable, GDB will read it.
4168 * Multi-arched targets.
4170 DEC Alpha (partial) alpha*-*-*
4171 DEC VAX (partial) vax-*-*
4173 National Semiconductor NS32000 (partial) ns32k-*-*
4174 Motorola 68000 (partial) m68k-*-*
4175 Motorola MCORE mcore-*-*
4179 Fujitsu FRV architecture added by Red Hat frv*-*-*
4182 * New native configurations
4184 Alpha NetBSD alpha*-*-netbsd*
4185 SH NetBSD sh*-*-netbsdelf*
4186 MIPS NetBSD mips*-*-netbsd*
4187 UltraSPARC NetBSD sparc64-*-netbsd*
4189 * OBSOLETE configurations and files
4191 Configurations that have been declared obsolete in this release have
4192 been commented out. Unless there is activity to revive these
4193 configurations, the next release of GDB will have their sources
4194 permanently REMOVED.
4196 Mitsubishi D30V d30v-*-*
4197 OS/9000 i[34]86-*-os9k
4198 IBM AIX PS/2 i[3456]86-*-aix
4199 Fujitsu FR30 fr30-*-elf*
4200 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4201 Argonaut Risc Chip (ARC) arc-*-*
4202 i386 running Mach 3.0 i[3456]86-*-mach3*
4203 i386 running Mach i[3456]86-*-mach*
4204 i386 running OSF/1 i[3456]86-*osf1mk*
4205 HP/Apollo 68k Family m68*-apollo*-sysv*,
4207 m68*-hp-bsd*, m68*-hp-hpux*
4208 I960 with MON960 i960-*-coff
4210 * OBSOLETE languages
4212 CHILL, a Pascal like language used by telecommunications companies.
4214 * REMOVED configurations and files
4216 AMD 29k family via UDI a29k-amd-udi, udi29k
4217 A29K VxWorks a29k-*-vxworks
4218 AMD 29000 embedded, using EBMON a29k-none-none
4219 AMD 29000 embedded with COFF a29k-none-coff
4220 AMD 29000 embedded with a.out a29k-none-aout
4222 testsuite/gdb.hp/gdb.threads-hp/ directory
4224 * New command "set max-user-call-depth <nnn>"
4226 This command allows the user to limit the call depth of user-defined
4227 commands. The default is 1024.
4229 * Changes in FreeBSD/i386 native debugging.
4231 Support for the "generate-core-file" has been added.
4233 * New commands "dump", "append", and "restore".
4235 These commands allow data to be copied from target memory
4236 to a bfd-format or binary file (dump and append), and back
4237 from a file into memory (restore).
4239 * Improved "next/step" support on multi-processor Alpha Tru64.
4241 The previous single-step mechanism could cause unpredictable problems,
4242 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4243 of a software single-step mechanism prevents this.
4245 *** Changes in GDB 5.2.1:
4253 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4254 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4255 Fix, by Joel Brobecker imported from mainline.
4257 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4258 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4259 Fix, by Fred Fish, imported from mainline.
4261 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4262 Surprisingly enough, it works now.
4263 By Michal Ludvig, imported from mainline.
4265 i386 hardware watchpoint support:
4266 avoid misses on second run for some targets.
4267 By Pierre Muller, imported from mainline.
4269 *** Changes in GDB 5.2:
4271 * New command "set trust-readonly-sections on[off]".
4273 This command is a hint that tells gdb that read-only sections
4274 really are read-only (ie. that their contents will not change).
4275 In this mode, gdb will go to the object file rather than the
4276 target to read memory from read-only sections (such as ".text").
4277 This can be a significant performance improvement on some
4278 (notably embedded) targets.
4280 * New command "generate-core-file" (or "gcore").
4282 This new gdb command allows the user to drop a core file of the child
4283 process state at any time. So far it's been implemented only for
4284 GNU/Linux and Solaris, but should be relatively easily ported to other
4285 hosts. Argument is core file name (defaults to core.<pid>).
4287 * New command line option
4289 GDB now accepts --pid or -p followed by a process id.
4291 * Change in command line behavior -- corefiles vs. process ids.
4293 There is a subtle behavior in the way in which GDB handles
4294 command line arguments. The first non-flag argument is always
4295 a program to debug, but the second non-flag argument may either
4296 be a corefile or a process id. Previously, GDB would attempt to
4297 open the second argument as a corefile, and if that failed, would
4298 issue a superfluous error message and then attempt to attach it as
4299 a process. Now, if the second argument begins with a non-digit,
4300 it will be treated as a corefile. If it begins with a digit,
4301 GDB will attempt to attach it as a process, and if no such process
4302 is found, will then attempt to open it as a corefile.
4304 * Changes in ARM configurations.
4306 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4307 configuration is fully multi-arch.
4309 * New native configurations
4311 ARM NetBSD arm*-*-netbsd*
4312 x86 OpenBSD i[3456]86-*-openbsd*
4313 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4314 Sparc64 running FreeBSD sparc64-*-freebsd*
4318 Sanyo XStormy16 xstormy16-elf
4320 * OBSOLETE configurations and files
4322 Configurations that have been declared obsolete in this release have
4323 been commented out. Unless there is activity to revive these
4324 configurations, the next release of GDB will have their sources
4325 permanently REMOVED.
4327 AMD 29k family via UDI a29k-amd-udi, udi29k
4328 A29K VxWorks a29k-*-vxworks
4329 AMD 29000 embedded, using EBMON a29k-none-none
4330 AMD 29000 embedded with COFF a29k-none-coff
4331 AMD 29000 embedded with a.out a29k-none-aout
4333 testsuite/gdb.hp/gdb.threads-hp/ directory
4335 * REMOVED configurations and files
4337 TI TMS320C80 tic80-*-*
4339 PowerPC Solaris powerpcle-*-solaris*
4340 PowerPC Windows NT powerpcle-*-cygwin32
4341 PowerPC Netware powerpc-*-netware*
4342 Harris/CXUX m88k m88*-harris-cxux*
4343 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4344 ns32k-utek-sysv* ns32k-utek-*
4345 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4346 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4347 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4348 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4349 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4351 * Changes to command line processing
4353 The new `--args' feature can be used to specify command-line arguments
4354 for the inferior from gdb's command line.
4356 * Changes to key bindings
4358 There is a new `operate-and-get-next' function bound to `C-o'.
4360 *** Changes in GDB 5.1.1
4362 Fix compile problem on DJGPP.
4364 Fix a problem with floating-point registers on the i386 being
4367 Fix to stop GDB crashing on .debug_str debug info.
4369 Numerous documentation fixes.
4371 Numerous testsuite fixes.
4373 *** Changes in GDB 5.1:
4375 * New native configurations
4377 Alpha FreeBSD alpha*-*-freebsd*
4378 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4379 MIPS GNU/Linux mips*-*-linux*
4380 MIPS SGI Irix 6.x mips*-sgi-irix6*
4381 ia64 AIX ia64-*-aix*
4382 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4386 Motorola 68HC11 and 68HC12 m68hc11-elf
4388 UltraSparc running GNU/Linux sparc64-*-linux*
4390 * OBSOLETE configurations and files
4392 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4393 Harris/CXUX m88k m88*-harris-cxux*
4394 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4395 ns32k-utek-sysv* ns32k-utek-*
4396 TI TMS320C80 tic80-*-*
4398 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4399 PowerPC Solaris powerpcle-*-solaris*
4400 PowerPC Windows NT powerpcle-*-cygwin32
4401 PowerPC Netware powerpc-*-netware*
4402 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4403 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4404 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4405 Apple Macintosh (MPW) host N/A
4407 stuff.c (Program to stuff files into a specially prepared space in kdb)
4408 kdb-start.c (Main loop for the standalone kernel debugger)
4410 Configurations that have been declared obsolete in this release have
4411 been commented out. Unless there is activity to revive these
4412 configurations, the next release of GDB will have their sources
4413 permanently REMOVED.
4415 * REMOVED configurations and files
4417 Altos 3068 m68*-altos-*
4418 Convex c1-*-*, c2-*-*
4420 ARM RISCix arm-*-* (as host)
4424 * GDB has been converted to ISO C.
4426 GDB's source code has been converted to ISO C. In particular, the
4427 sources are fully protoized, and rely on standard headers being
4432 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4434 * The MI enabled by default.
4436 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4437 revised and enabled by default. Packages which use GDB as a debugging
4438 engine behind a UI or another front end are encouraged to switch to
4439 using the GDB/MI interface, instead of the old annotations interface
4440 which is now deprecated.
4442 * Support for debugging Pascal programs.
4444 GDB now includes support for debugging Pascal programs. The following
4445 main features are supported:
4447 - Pascal-specific data types such as sets;
4449 - automatic recognition of Pascal sources based on file-name
4452 - Pascal-style display of data types, variables, and functions;
4454 - a Pascal expression parser.
4456 However, some important features are not yet supported.
4458 - Pascal string operations are not supported at all;
4460 - there are some problems with boolean types;
4462 - Pascal type hexadecimal constants are not supported
4463 because they conflict with the internal variables format;
4465 - support for Pascal objects and classes is not full yet;
4467 - unlike Pascal, GDB is case-sensitive for symbol names.
4469 * Changes in completion.
4471 Commands such as `shell', `run' and `set args', which pass arguments
4472 to inferior programs, now complete on file names, similar to what
4473 users expect at the shell prompt.
4475 Commands which accept locations, such as `disassemble', `print',
4476 `breakpoint', `until', etc. now complete on filenames as well as
4477 program symbols. Thus, if you type "break foob TAB", and the source
4478 files linked into the programs include `foobar.c', that file name will
4479 be one of the candidates for completion. However, file names are not
4480 considered for completion after you typed a colon that delimits a file
4481 name from a name of a function in that file, as in "break foo.c:bar".
4483 `set demangle-style' completes on available demangling styles.
4485 * New platform-independent commands:
4487 It is now possible to define a post-hook for a command as well as a
4488 hook that runs before the command. For more details, see the
4489 documentation of `hookpost' in the GDB manual.
4491 * Changes in GNU/Linux native debugging.
4493 Support for debugging multi-threaded programs has been completely
4494 revised for all platforms except m68k and sparc. You can now debug as
4495 many threads as your system allows you to have.
4497 Attach/detach is supported for multi-threaded programs.
4499 Support for SSE registers was added for x86. This doesn't work for
4500 multi-threaded programs though.
4502 * Changes in MIPS configurations.
4504 Multi-arch support is enabled for all MIPS configurations.
4506 GDB can now be built as native debugger on SGI Irix 6.x systems for
4507 debugging n32 executables. (Debugging 64-bit executables is not yet
4510 * Unified support for hardware watchpoints in all x86 configurations.
4512 Most (if not all) native x86 configurations support hardware-assisted
4513 breakpoints and watchpoints in a unified manner. This support
4514 implements debug register sharing between watchpoints, which allows to
4515 put a virtually infinite number of watchpoints on the same address,
4516 and also supports watching regions up to 16 bytes with several debug
4519 The new maintenance command `maintenance show-debug-regs' toggles
4520 debugging print-outs in functions that insert, remove, and test
4521 watchpoints and hardware breakpoints.
4523 * Changes in the DJGPP native configuration.
4525 New command ``info dos sysinfo'' displays assorted information about
4526 the CPU, OS, memory, and DPMI server.
4528 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4529 display information about segment descriptors stored in GDT, LDT, and
4532 New commands ``info dos pde'' and ``info dos pte'' display entries
4533 from Page Directory and Page Tables (for now works with CWSDPMI only).
4534 New command ``info dos address-pte'' displays the Page Table entry for
4535 a given linear address.
4537 GDB can now pass command lines longer than 126 characters to the
4538 program being debugged (requires an update to the libdbg.a library
4539 which is part of the DJGPP development kit).
4541 DWARF2 debug info is now supported.
4543 It is now possible to `step' and `next' through calls to `longjmp'.
4545 * Changes in documentation.
4547 All GDB documentation was converted to GFDL, the GNU Free
4548 Documentation License.
4550 Tracepoints-related commands are now fully documented in the GDB
4553 TUI, the Text-mode User Interface, is now documented in the manual.
4555 Tracepoints-related commands are now fully documented in the GDB
4558 The "GDB Internals" manual now has an index. It also includes
4559 documentation of `ui_out' functions, GDB coding standards, x86
4560 hardware watchpoints, and memory region attributes.
4562 * GDB's version number moved to ``version.in''
4564 The Makefile variable VERSION has been replaced by the file
4565 ``version.in''. People creating GDB distributions should update the
4566 contents of this file.
4570 GUD support is now a standard part of the EMACS distribution.
4572 *** Changes in GDB 5.0:
4574 * Improved support for debugging FP programs on x86 targets
4576 Unified and much-improved support for debugging floating-point
4577 programs on all x86 targets. In particular, ``info float'' now
4578 displays the FP registers in the same format on all x86 targets, with
4579 greater level of detail.
4581 * Improvements and bugfixes in hardware-assisted watchpoints
4583 It is now possible to watch array elements, struct members, and
4584 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4585 on x86 targets no longer erroneously trigger when the address is
4588 * Improvements in the native DJGPP version of GDB
4590 The distribution now includes all the scripts and auxiliary files
4591 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4592 machines ``out of the box''.
4594 The DJGPP version can now debug programs that use signals. It is
4595 possible to catch signals that happened in the debuggee, deliver
4596 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4597 would kill the program being debugged.) Programs that hook hardware
4598 interrupts (keyboard, timer, etc.) can also be debugged.
4600 It is now possible to debug DJGPP programs that redirect their
4601 standard handles or switch them to raw (as opposed to cooked) mode, or
4602 even close them. The command ``run < foo > bar'' works as expected,
4603 and ``info terminal'' reports useful information about the debuggee's
4604 terminal, including raw/cooked mode, redirection, etc.
4606 The DJGPP version now uses termios functions for console I/O, which
4607 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4610 DOS-style file names with drive letters are now fully supported by
4613 It is now possible to debug DJGPP programs that switch their working
4614 directory. It is also possible to rerun the debuggee any number of
4615 times without restarting GDB; thus, you can use the same setup,
4616 breakpoints, etc. for many debugging sessions.
4618 * New native configurations
4620 ARM GNU/Linux arm*-*-linux*
4621 PowerPC GNU/Linux powerpc-*-linux*
4625 Motorola MCore mcore-*-*
4626 x86 VxWorks i[3456]86-*-vxworks*
4627 PowerPC VxWorks powerpc-*-vxworks*
4628 TI TMS320C80 tic80-*-*
4630 * OBSOLETE configurations
4632 Altos 3068 m68*-altos-*
4633 Convex c1-*-*, c2-*-*
4635 ARM RISCix arm-*-* (as host)
4638 Configurations that have been declared obsolete will be commented out,
4639 but the code will be left in place. If there is no activity to revive
4640 these configurations before the next release of GDB, the sources will
4641 be permanently REMOVED.
4643 * Gould support removed
4645 Support for the Gould PowerNode and NP1 has been removed.
4647 * New features for SVR4
4649 On SVR4 native platforms (such as Solaris), if you attach to a process
4650 without first loading a symbol file, GDB will now attempt to locate and
4651 load symbols from the running process's executable file.
4653 * Many C++ enhancements
4655 C++ support has been greatly improved. Overload resolution now works properly
4656 in almost all cases. RTTI support is on the way.
4658 * Remote targets can connect to a sub-program
4660 A popen(3) style serial-device has been added. This device starts a
4661 sub-process (such as a stand-alone simulator) and then communicates
4662 with that. The sub-program to run is specified using the syntax
4663 ``|<program> <args>'' vis:
4665 (gdb) set remotedebug 1
4666 (gdb) target extended-remote |mn10300-elf-sim program-args
4668 * MIPS 64 remote protocol
4670 A long standing bug in the mips64 remote protocol where by GDB
4671 expected certain 32 bit registers (ex SR) to be transfered as 32
4672 instead of 64 bits has been fixed.
4674 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4675 added to provide backward compatibility with older versions of GDB.
4677 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4679 The command ``set remotebinarydownload'' command has been replaced by
4680 ``set remote X-packet''. Other commands in ``set remote'' family
4681 include ``set remote P-packet''.
4683 * Breakpoint commands accept ranges.
4685 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4686 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4687 ``tracepoint passcount'' also accepts a range of tracepoints.
4689 * ``apropos'' command added.
4691 The ``apropos'' command searches through command names and
4692 documentation strings, printing out matches, making it much easier to
4693 try to find a command that does what you are looking for.
4697 A new machine oriented interface (MI) has been added to GDB. This
4698 interface is designed for debug environments running GDB as a separate
4699 process. This is part of the long term libGDB project. See the
4700 "GDB/MI" chapter of the GDB manual for further information. It can be
4701 enabled by configuring with:
4703 .../configure --enable-gdbmi
4705 *** Changes in GDB-4.18:
4707 * New native configurations
4709 HP-UX 10.20 hppa*-*-hpux10.20
4710 HP-UX 11.x hppa*-*-hpux11.0*
4711 M68K GNU/Linux m68*-*-linux*
4715 Fujitsu FR30 fr30-*-elf*
4716 Intel StrongARM strongarm-*-*
4717 Mitsubishi D30V d30v-*-*
4719 * OBSOLETE configurations
4721 Gould PowerNode, NP1 np1-*-*, pn-*-*
4723 Configurations that have been declared obsolete will be commented out,
4724 but the code will be left in place. If there is no activity to revive
4725 these configurations before the next release of GDB, the sources will
4726 be permanently REMOVED.
4730 As a compatibility experiment, GDB's source files buildsym.h and
4731 buildsym.c have been converted to pure standard C, no longer
4732 containing any K&R compatibility code. We believe that all systems in
4733 use today either come with a standard C compiler, or have a GCC port
4734 available. If this is not true, please report the affected
4735 configuration to bug-gdb@gnu.org immediately. See the README file for
4736 information about getting a standard C compiler if you don't have one
4741 GDB now uses readline 2.2.
4743 * set extension-language
4745 You can now control the mapping between filename extensions and source
4746 languages by using the `set extension-language' command. For instance,
4747 you can ask GDB to treat .c files as C++ by saying
4748 set extension-language .c c++
4749 The command `info extensions' lists all of the recognized extensions
4750 and their associated languages.
4752 * Setting processor type for PowerPC and RS/6000
4754 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4755 you can use the `set processor' command to specify what variant of the
4756 PowerPC family you are debugging. The command
4760 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4761 following PowerPC and RS6000 variants:
4763 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4764 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4766 403GC IBM PowerPC 403GC
4767 505 Motorola PowerPC 505
4768 860 Motorola PowerPC 860 or 850
4769 601 Motorola PowerPC 601
4770 602 Motorola PowerPC 602
4771 603 Motorola/IBM PowerPC 603 or 603e
4772 604 Motorola PowerPC 604 or 604e
4773 750 Motorola/IBM PowerPC 750 or 750
4775 At the moment, this command just tells GDB what to name the
4776 special-purpose processor registers. Since almost all the affected
4777 registers are inaccessible to user-level programs, this command is
4778 only useful for remote debugging in its present form.
4782 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4783 more extensive support for HP-UX. Added features include shared
4784 library support, kernel threads and hardware watchpoints for 11.00,
4785 support for HP's ANSI C and C++ compilers, and a compatibility mode
4786 for xdb and dbx commands.
4790 HP's donation includes the new concept of catchpoints, which is a
4791 generalization of the old catch command. On HP-UX, it is now possible
4792 to catch exec, fork, and vfork, as well as library loading.
4794 This means that the existing catch command has changed; its first
4795 argument now specifies the type of catch to be set up. See the
4796 output of "help catch" for a list of catchpoint types.
4798 * Debugging across forks
4800 On HP-UX, you can choose which process to debug when a fork() happens
4805 HP has donated a curses-based terminal user interface (TUI). To get
4806 it, build with --enable-tui. Although this can be enabled for any
4807 configuration, at present it only works for native HP debugging.
4809 * GDB remote protocol additions
4811 A new protocol packet 'X' that writes binary data is now available.
4812 Default behavior is to try 'X', then drop back to 'M' if the stub
4813 fails to respond. The settable variable `remotebinarydownload'
4814 allows explicit control over the use of 'X'.
4816 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4817 full 64-bit address. The command
4819 set remoteaddresssize 32
4821 can be used to revert to the old behaviour. For existing remote stubs
4822 the change should not be noticed, as the additional address information
4825 In order to assist in debugging stubs, you may use the maintenance
4826 command `packet' to send any text string to the stub. For instance,
4828 maint packet heythere
4830 sends the packet "$heythere#<checksum>". Note that it is very easy to
4831 disrupt a debugging session by sending the wrong packet at the wrong
4834 The compare-sections command allows you to compare section data on the
4835 target to what is in the executable file without uploading or
4836 downloading, by comparing CRC checksums.
4838 * Tracing can collect general expressions
4840 You may now collect general expressions at tracepoints. This requires
4841 further additions to the target-side stub; see tracepoint.c and
4842 doc/agentexpr.texi for further details.
4844 * mask-address variable for Mips
4846 For Mips targets, you may control the zeroing of the upper 32 bits of
4847 a 64-bit address by entering `set mask-address on'. This is mainly
4848 of interest to users of embedded R4xxx and R5xxx processors.
4850 * Higher serial baud rates
4852 GDB's serial code now allows you to specify baud rates 57600, 115200,
4853 230400, and 460800 baud. (Note that your host system may not be able
4854 to achieve all of these rates.)
4858 The i960 configuration now includes an initial implementation of a
4859 builtin simulator, contributed by Jim Wilson.
4862 *** Changes in GDB-4.17:
4864 * New native configurations
4866 Alpha GNU/Linux alpha*-*-linux*
4867 Unixware 2.x i[3456]86-unixware2*
4868 Irix 6.x mips*-sgi-irix6*
4869 PowerPC GNU/Linux powerpc-*-linux*
4870 PowerPC Solaris powerpcle-*-solaris*
4871 Sparc GNU/Linux sparc-*-linux*
4872 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4876 Argonaut Risc Chip (ARC) arc-*-*
4877 Hitachi H8/300S h8300*-*-*
4878 Matsushita MN10200 w/simulator mn10200-*-*
4879 Matsushita MN10300 w/simulator mn10300-*-*
4880 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4881 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4882 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4883 Mitsubishi D10V w/simulator d10v-*-*
4884 Mitsubishi M32R/D w/simulator m32r-*-elf*
4885 Tsqware Sparclet sparclet-*-*
4886 NEC V850 w/simulator v850-*-*
4888 * New debugging protocols
4890 ARM with RDI protocol arm*-*-*
4891 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4892 DDB and LSI variants of PMON protocol mips*-*-*
4893 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4894 PowerPC with SDS protocol powerpc{,le}-*-eabi
4895 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4899 All configurations can now understand and use the DWARF 2 debugging
4900 format. The choice is automatic, if the symbol file contains DWARF 2
4905 GDB now includes basic Java language support. This support is
4906 only useful with Java compilers that produce native machine code.
4908 * solib-absolute-prefix and solib-search-path
4910 For SunOS and SVR4 shared libraries, you may now set the prefix for
4911 loading absolute shared library symbol files, and the search path for
4912 locating non-absolute shared library symbol files.
4914 * Live range splitting
4916 GDB can now effectively debug code for which GCC has performed live
4917 range splitting as part of its optimization. See gdb/doc/LRS for
4918 more details on the expected format of the stabs information.
4922 GDB's support for the GNU Hurd, including thread debugging, has been
4923 updated to work with current versions of the Hurd.
4927 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4928 instruction set. ARM GDB automatically detects when Thumb
4929 instructions are in use, and adjusts disassembly and backtracing
4934 GDB's MIPS target configurations now handle the MIP16 16-bit
4939 GDB now includes support for overlays; if an executable has been
4940 linked such that multiple sections are based at the same address, GDB
4941 will decide which section to use for symbolic info. You can choose to
4942 control the decision manually, using overlay commands, or implement
4943 additional target-side support and use "overlay load-target" to bring
4944 in the overlay mapping. Do "help overlay" for more detail.
4948 The command "info symbol <address>" displays information about
4949 the symbol at the specified address.
4953 The standard remote protocol now includes an extension that allows
4954 asynchronous collection and display of trace data. This requires
4955 extensive support in the target-side debugging stub. Tracing mode
4956 includes a new interaction mode in GDB and new commands: see the
4957 file tracepoint.c for more details.
4961 Configurations for embedded MIPS now include a simulator contributed
4962 by Cygnus Solutions. The simulator supports the instruction sets
4963 of most MIPS variants.
4967 Sparc configurations may now include the ERC32 simulator contributed
4968 by the European Space Agency. The simulator is not built into
4969 Sparc targets by default; configure with --enable-sim to include it.
4973 For target configurations that may include multiple variants of a
4974 basic architecture (such as MIPS and SH), you may now set the
4975 architecture explicitly. "set arch" sets, "info arch" lists
4976 the possible architectures.
4978 *** Changes in GDB-4.16:
4980 * New native configurations
4982 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4983 M68K NetBSD m68k-*-netbsd*
4984 PowerPC AIX 4.x powerpc-*-aix*
4985 PowerPC MacOS powerpc-*-macos*
4986 PowerPC Windows NT powerpcle-*-cygwin32
4987 RS/6000 AIX 4.x rs6000-*-aix4*
4991 ARM with RDP protocol arm-*-*
4992 I960 with MON960 i960-*-coff
4993 MIPS VxWorks mips*-*-vxworks*
4994 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4995 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4997 Matra Sparclet sparclet-*-*
5001 The powerpc-eabi configuration now includes the PSIM simulator,
5002 contributed by Andrew Cagney, with assistance from Mike Meissner.
5003 PSIM is a very elaborate model of the PowerPC, including not only
5004 basic instruction set execution, but also details of execution unit
5005 performance and I/O hardware. See sim/ppc/README for more details.
5009 GDB now works with Solaris 2.5.
5011 * Windows 95/NT native
5013 GDB will now work as a native debugger on Windows 95 and Windows NT.
5014 To build it from source, you must use the "gnu-win32" environment,
5015 which uses a DLL to emulate enough of Unix to run the GNU tools.
5016 Further information, binaries, and sources are available at
5017 ftp.cygnus.com, under pub/gnu-win32.
5019 * dont-repeat command
5021 If a user-defined command includes the command `dont-repeat', then the
5022 command will not be repeated if the user just types return. This is
5023 useful if the command is time-consuming to run, so that accidental
5024 extra keystrokes don't run the same command many times.
5026 * Send break instead of ^C
5028 The standard remote protocol now includes an option to send a break
5029 rather than a ^C to the target in order to interrupt it. By default,
5030 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5032 * Remote protocol timeout
5034 The standard remote protocol includes a new variable `remotetimeout'
5035 that allows you to set the number of seconds before GDB gives up trying
5036 to read from the target. The default value is 2.
5038 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5040 By default GDB will automatically keep track of objects as they are
5041 loaded and unloaded by the dynamic linker. By using the command `set
5042 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5043 when shared library events occur, thus allowing you to set breakpoints
5044 in shared libraries which are explicitly loaded by the inferior.
5046 Note this feature does not work on hpux8. On hpux9 you must link
5047 /usr/lib/end.o into your program. This feature should work
5048 automatically on hpux10.
5050 * Irix 5.x hardware watchpoint support
5052 Irix 5 configurations now support the use of hardware watchpoints.
5054 * Mips protocol "SYN garbage limit"
5056 When debugging a Mips target using the `target mips' protocol, you
5057 may set the number of characters that GDB will ignore by setting
5058 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5059 every character. The default value is 1050.
5061 * Recording and replaying remote debug sessions
5063 If you set `remotelogfile' to the name of a file, gdb will write to it
5064 a recording of a remote debug session. This recording may then be
5065 replayed back to gdb using "gdbreplay". See gdbserver/README for
5066 details. This is useful when you have a problem with GDB while doing
5067 remote debugging; you can make a recording of the session and send it
5068 to someone else, who can then recreate the problem.
5070 * Speedups for remote debugging
5072 GDB includes speedups for downloading and stepping MIPS systems using
5073 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5074 and more efficient S-record downloading.
5076 * Memory use reductions and statistics collection
5078 GDB now uses less memory and reports statistics about memory usage.
5079 Try the `maint print statistics' command, for example.
5081 *** Changes in GDB-4.15:
5083 * Psymtabs for XCOFF
5085 The symbol reader for AIX GDB now uses partial symbol tables. This
5086 can greatly improve startup time, especially for large executables.
5088 * Remote targets use caching
5090 Remote targets now use a data cache to speed up communication with the
5091 remote side. The data cache could lead to incorrect results because
5092 it doesn't know about volatile variables, thus making it impossible to
5093 debug targets which use memory mapped I/O devices. `set remotecache
5094 off' turns the the data cache off.
5096 * Remote targets may have threads
5098 The standard remote protocol now includes support for multiple threads
5099 in the target system, using new protocol commands 'H' and 'T'. See
5100 gdb/remote.c for details.
5104 If GDB is configured with `--enable-netrom', then it will include
5105 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5106 acts as though it is a bank of ROM on the target board, but you can
5107 write into it over the network. GDB's support consists only of
5108 support for fast loading into the emulated ROM; to debug, you must use
5109 another protocol, such as standard remote protocol. The usual
5110 sequence is something like
5112 target nrom <netrom-hostname>
5114 target remote <netrom-hostname>:1235
5118 GDB now includes support for the Apple Macintosh, as a host only. It
5119 may be run as either an MPW tool or as a standalone application, and
5120 it can debug through the serial port. All the usual GDB commands are
5121 available, but to the target command, you must supply "serial" as the
5122 device type instead of "/dev/ttyXX". See mpw-README in the main
5123 directory for more information on how to build. The MPW configuration
5124 scripts */mpw-config.in support only a few targets, and only the
5125 mips-idt-ecoff target has been tested.
5129 GDB configuration now uses autoconf. This is not user-visible,
5130 but does simplify configuration and building.
5134 GDB now supports hpux10.
5136 *** Changes in GDB-4.14:
5138 * New native configurations
5140 x86 FreeBSD i[345]86-*-freebsd
5141 x86 NetBSD i[345]86-*-netbsd
5142 NS32k NetBSD ns32k-*-netbsd
5143 Sparc NetBSD sparc-*-netbsd
5147 A29K VxWorks a29k-*-vxworks
5148 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5149 CPU32 EST-300 emulator m68*-*-est*
5150 PowerPC ELF powerpc-*-elf
5153 * Alpha OSF/1 support for procfs
5155 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5156 possible to attach to running processes. As the mounting of the /proc
5157 filesystem is optional on the Alpha, GDB automatically determines
5158 the availability of /proc during startup. This can lead to problems
5159 if /proc is unmounted after GDB has been started.
5161 * Arguments to user-defined commands
5163 User commands may accept up to 10 arguments separated by whitespace.
5164 Arguments are accessed within the user command via $arg0..$arg9. A
5167 print $arg0 + $arg1 + $arg2
5169 To execute the command use:
5172 Defines the command "adder" which prints the sum of its three arguments.
5173 Note the arguments are text substitutions, so they may reference variables,
5174 use complex expressions, or even perform inferior function calls.
5176 * New `if' and `while' commands
5178 This makes it possible to write more sophisticated user-defined
5179 commands. Both commands take a single argument, which is the
5180 expression to evaluate, and must be followed by the commands to
5181 execute, one per line, if the expression is nonzero, the list being
5182 terminated by the word `end'. The `if' command list may include an
5183 `else' word, which causes the following commands to be executed only
5184 if the expression is zero.
5186 * Fortran source language mode
5188 GDB now includes partial support for Fortran 77. It will recognize
5189 Fortran programs and can evaluate a subset of Fortran expressions, but
5190 variables and functions may not be handled correctly. GDB will work
5191 with G77, but does not yet know much about symbols emitted by other
5194 * Better HPUX support
5196 Most debugging facilities now work on dynamic executables for HPPAs
5197 running hpux9 or later. You can attach to running dynamically linked
5198 processes, but by default the dynamic libraries will be read-only, so
5199 for instance you won't be able to put breakpoints in them. To change
5200 that behavior do the following before running the program:
5206 This will cause the libraries to be mapped private and read-write.
5207 To revert to the normal behavior, do this:
5213 You cannot set breakpoints or examine data in the library until after
5214 the library is loaded if the function/data symbols do not have
5217 GDB can now also read debug symbols produced by the HP C compiler on
5218 HPPAs (sorry, no C++, Fortran or 68k support).
5220 * Target byte order now dynamically selectable
5222 You can choose which byte order to use with a target system, via the
5223 commands "set endian big" and "set endian little", and you can see the
5224 current setting by using "show endian". You can also give the command
5225 "set endian auto", in which case GDB will use the byte order
5226 associated with the executable. Currently, only embedded MIPS
5227 configurations support dynamic selection of target byte order.
5229 * New DOS host serial code
5231 This version uses DPMI interrupts to handle buffered I/O, so you
5232 no longer need to run asynctsr when debugging boards connected to
5235 *** Changes in GDB-4.13:
5237 * New "complete" command
5239 This lists all the possible completions for the rest of the line, if it
5240 were to be given as a command itself. This is intended for use by emacs.
5242 * Trailing space optional in prompt
5244 "set prompt" no longer adds a space for you after the prompt you set. This
5245 allows you to set a prompt which ends in a space or one that does not.
5247 * Breakpoint hit counts
5249 "info break" now displays a count of the number of times the breakpoint
5250 has been hit. This is especially useful in conjunction with "ignore"; you
5251 can ignore a large number of breakpoint hits, look at the breakpoint info
5252 to see how many times the breakpoint was hit, then run again, ignoring one
5253 less than that number, and this will get you quickly to the last hit of
5256 * Ability to stop printing at NULL character
5258 "set print null-stop" will cause GDB to stop printing the characters of
5259 an array when the first NULL is encountered. This is useful when large
5260 arrays actually contain only short strings.
5262 * Shared library breakpoints
5264 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5265 breakpoints in shared libraries before the executable is run.
5267 * Hardware watchpoints
5269 There is a new hardware breakpoint for the watch command for sparclite
5270 targets. See gdb/sparclite/hw_breakpoint.note.
5272 Hardware watchpoints are also now supported under GNU/Linux.
5276 Annotations have been added. These are for use with graphical interfaces,
5277 and are still experimental. Currently only gdba.el uses these.
5279 * Improved Irix 5 support
5281 GDB now works properly with Irix 5.2.
5283 * Improved HPPA support
5285 GDB now works properly with the latest GCC and GAS.
5287 * New native configurations
5289 Sequent PTX4 i[34]86-sequent-ptx4
5290 HPPA running OSF/1 hppa*-*-osf*
5291 Atari TT running SVR4 m68*-*-sysv4*
5292 RS/6000 LynxOS rs6000-*-lynxos*
5296 OS/9000 i[34]86-*-os9k
5297 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5300 * Hitachi SH7000 and E7000-PC ICE support
5302 There is now support for communicating with the Hitachi E7000-PC ICE.
5303 This is available automatically when GDB is configured for the SH.
5307 As usual, a variety of small fixes and improvements, both generic
5308 and configuration-specific. See the ChangeLog for more detail.
5310 *** Changes in GDB-4.12:
5312 * Irix 5 is now supported
5316 GDB-4.12 on the HPPA has a number of changes which make it unable
5317 to debug the output from the currently released versions of GCC and
5318 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5319 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5320 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5323 *** Changes in GDB-4.11:
5325 * User visible changes:
5329 The "set remotedebug" option is now consistent between the mips remote
5330 target, remote targets using the gdb-specific protocol, UDI (AMD's
5331 debug protocol for the 29k) and the 88k bug monitor. It is now an
5332 integer specifying a debug level (normally 0 or 1, but 2 means more
5333 debugging info for the mips target).
5335 * DEC Alpha native support
5337 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5338 debug info, but GDB works fairly well with the DEC compiler and should
5339 work with a future GCC release. See the README file for a few
5340 Alpha-specific notes.
5342 * Preliminary thread implementation
5344 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5346 * LynxOS native and target support for 386
5348 This release has been hosted on LynxOS 2.2, and also can be configured
5349 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5352 * Improvements in C++ mangling/demangling.
5354 This release has much better g++ debugging, specifically in name
5355 mangling/demangling, virtual function calls, print virtual table,
5356 call methods, ...etc.
5358 *** Changes in GDB-4.10:
5360 * User visible changes:
5362 Remote debugging using the GDB-specific (`target remote') protocol now
5363 supports the `load' command. This is only useful if you have some
5364 other way of getting the stub to the target system, and you can put it
5365 somewhere in memory where it won't get clobbered by the download.
5367 Filename completion now works.
5369 When run under emacs mode, the "info line" command now causes the
5370 arrow to point to the line specified. Also, "info line" prints
5371 addresses in symbolic form (as well as hex).
5373 All vxworks based targets now support a user settable option, called
5374 vxworks-timeout. This option represents the number of seconds gdb
5375 should wait for responses to rpc's. You might want to use this if
5376 your vxworks target is, perhaps, a slow software simulator or happens
5377 to be on the far side of a thin network line.
5381 This release contains support for using a DEC alpha as a GDB host for
5382 cross debugging. Native alpha debugging is not supported yet.
5385 *** Changes in GDB-4.9:
5389 This is the first GDB release which is accompanied by a matching testsuite.
5390 The testsuite requires installation of dejagnu, which should be available
5391 via ftp from most sites that carry GNU software.
5395 'Cfront' style demangling has had its name changed to 'ARM' style, to
5396 emphasize that it was written from the specifications in the C++ Annotated
5397 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5398 disclaimers, it still generated too much confusion with users attempting to
5399 use gdb with AT&T cfront.
5403 GDB now uses a standard remote interface to a simulator library.
5404 So far, the library contains simulators for the Zilog Z8001/2, the
5405 Hitachi H8/300, H8/500 and Super-H.
5407 * New targets supported
5409 H8/300 simulator h8300-hitachi-hms or h8300hms
5410 H8/500 simulator h8500-hitachi-hms or h8500hms
5411 SH simulator sh-hitachi-hms or sh
5412 Z8000 simulator z8k-zilog-none or z8ksim
5413 IDT MIPS board over serial line mips-idt-ecoff
5415 Cross-debugging to GO32 targets is supported. It requires a custom
5416 version of the i386-stub.c module which is integrated with the
5417 GO32 memory extender.
5419 * New remote protocols
5421 MIPS remote debugging protocol.
5423 * New source languages supported
5425 This version includes preliminary support for Chill, a Pascal like language
5426 used by telecommunications companies. Chill support is also being integrated
5427 into the GNU compiler, but we don't know when it will be publically available.
5430 *** Changes in GDB-4.8:
5432 * HP Precision Architecture supported
5434 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5435 version of this support was available as a set of patches from the
5436 University of Utah. GDB does not support debugging of programs
5437 compiled with the HP compiler, because HP will not document their file
5438 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5439 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5441 Many problems in the preliminary version have been fixed.
5443 * Faster and better demangling
5445 We have improved template demangling and fixed numerous bugs in the GNU style
5446 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5447 character types (wchar_t) are now supported. Demangling of each symbol is now
5448 only done once, and is cached when the symbol table for a file is read in.
5449 This results in a small increase in memory usage for C programs, a moderate
5450 increase in memory usage for C++ programs, and a fantastic speedup in
5453 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5454 from the specifications in the Annotated Reference Manual, which AT&T's
5455 compiler does not actually implement.
5457 * G++ multiple inheritance compiler problem
5459 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5460 inheritance lattices was reworked to properly discover ambiguities. We
5461 recently found an example which causes this new algorithm to fail in a
5462 very subtle way, producing bad debug information for those classes.
5463 The file 'gcc.patch' (in this directory) can be applied to gcc to
5464 circumvent the problem. A future GCC release will contain a complete
5467 The previous G++ debug info problem (mentioned below for the gdb-4.7
5468 release) is fixed in gcc version 2.3.2.
5470 * Improved configure script
5472 The `configure' script will now attempt to guess your system type if
5473 you don't supply a host system type. The old scheme of supplying a
5474 host system triplet is preferable over using this. All the magic is
5475 done in the new `config.guess' script. Examine it for details.
5477 We have also brought our configure script much more in line with the FSF's
5478 version. It now supports the --with-xxx options. In particular,
5479 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5480 The resulting GDB will not be able to read arbitrary object file formats --
5481 only the format ``expected'' to be used on the configured target system.
5482 We hope to make this the default in a future release.
5484 * Documentation improvements
5486 There's new internal documentation on how to modify GDB, and how to
5487 produce clean changes to the code. We implore people to read it
5488 before submitting changes.
5490 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5491 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5492 `info' files are also provided. To build `info' files from scratch,
5493 you will need the latest `makeinfo' release, which will be available in
5494 a future texinfo-X.Y release.
5496 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5497 We're not sure exactly which versions have this problem, but it has
5498 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5499 or better. If that isn't possible, there is a patch in
5500 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5501 around this problem.
5505 GDB now supports array constants that can be used in expressions typed in by
5506 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5507 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5510 The new directory `gdb/sparclite' contains a program that demonstrates
5511 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5513 * New native hosts supported
5515 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5516 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5518 * New targets supported
5520 AMD 29k family via UDI a29k-amd-udi or udi29k
5522 * New file formats supported
5524 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5525 HPUX core files, and SCO 3.2v2 core files.
5529 Attaching to processes now works again; thanks for the many bug reports.
5531 We have also stomped on a bunch of core dumps caused by
5532 printf_filtered("%s") problems.
5534 We eliminated a copyright problem on the rpc and ptrace header files
5535 for VxWorks, which was discovered at the last minute during the 4.7
5536 release. You should now be able to build a VxWorks GDB.
5538 You can now interrupt gdb while an attached process is running. This
5539 will cause the attached process to stop, and give control back to GDB.
5541 We fixed problems caused by using too many file descriptors
5542 for reading symbols from object files and libraries. This was
5543 especially a problem for programs that used many (~100) shared
5546 The `step' command now only enters a subroutine if there is line number
5547 information for the subroutine. Otherwise it acts like the `next'
5548 command. Previously, `step' would enter subroutines if there was
5549 any debugging information about the routine. This avoids problems
5550 when using `cc -g1' on MIPS machines.
5552 * Internal improvements
5554 GDB's internal interfaces have been improved to make it easier to support
5555 debugging of multiple languages in the future.
5557 GDB now uses a common structure for symbol information internally.
5558 Minimal symbols (derived from linkage symbols in object files), partial
5559 symbols (from a quick scan of debug information), and full symbols
5560 contain a common subset of information, making it easier to write
5561 shared code that handles any of them.
5563 * New command line options
5565 We now accept --silent as an alias for --quiet.
5569 The memory-mapped-malloc library is now licensed under the GNU Library
5570 General Public License.
5572 *** Changes in GDB-4.7:
5574 * Host/native/target split
5576 GDB has had some major internal surgery to untangle the support for
5577 hosts and remote targets. Now, when you configure GDB for a remote
5578 target, it will no longer load in all of the support for debugging
5579 local programs on the host. When fully completed and tested, this will
5580 ensure that arbitrary host/target combinations are possible.
5582 The primary conceptual shift is to separate the non-portable code in
5583 GDB into three categories. Host specific code is required any time GDB
5584 is compiled on that host, regardless of the target. Target specific
5585 code relates to the peculiarities of the target, but can be compiled on
5586 any host. Native specific code is everything else: it can only be
5587 built when the host and target are the same system. Child process
5588 handling and core file support are two common `native' examples.
5590 GDB's use of /proc for controlling Unix child processes is now cleaner.
5591 It has been split out into a single module under the `target_ops' vector,
5592 plus two native-dependent functions for each system that uses /proc.
5594 * New hosts supported
5596 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5597 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5598 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5600 * New targets supported
5602 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5603 68030 and CPU32 m68030-*-*, m68332-*-*
5605 * New native hosts supported
5607 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5608 (386bsd is not well tested yet)
5609 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5611 * New file formats supported
5613 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5614 supports reading of `a.out.adobe' object files, which are an a.out
5615 format extended with minimal information about multiple sections.
5619 `show copying' is the same as the old `info copying'.
5620 `show warranty' is the same as `info warrantee'.
5621 These were renamed for consistency. The old commands continue to work.
5623 `info handle' is a new alias for `info signals'.
5625 You can now define pre-command hooks, which attach arbitrary command
5626 scripts to any command. The commands in the hook will be executed
5627 prior to the user's command. You can also create a hook which will be
5628 executed whenever the program stops. See gdb.texinfo.
5632 We now deal with Cfront style name mangling, and can even extract type
5633 info from mangled symbols. GDB can automatically figure out which
5634 symbol mangling style your C++ compiler uses.
5636 Calling of methods and virtual functions has been improved as well.
5640 The crash that occured when debugging Sun Ansi-C compiled binaries is
5641 fixed. This was due to mishandling of the extra N_SO stabs output
5644 We also finally got Ultrix 4.2 running in house, and fixed core file
5645 support, with help from a dozen people on the net.
5647 John M. Farrell discovered that the reason that single-stepping was so
5648 slow on all of the Mips based platforms (primarily SGI and DEC) was
5649 that we were trying to demangle and lookup a symbol used for internal
5650 purposes on every instruction that was being stepped through. Changing
5651 the name of that symbol so that it couldn't be mistaken for a C++
5652 mangled symbol sped things up a great deal.
5654 Rich Pixley sped up symbol lookups in general by getting much smarter
5655 about when C++ symbol mangling is necessary. This should make symbol
5656 completion (TAB on the command line) much faster. It's not as fast as
5657 we'd like, but it's significantly faster than gdb-4.6.
5661 A new user controllable variable 'call_scratch_address' can
5662 specify the location of a scratch area to be used when GDB
5663 calls a function in the target. This is necessary because the
5664 usual method of putting the scratch area on the stack does not work
5665 in systems that have separate instruction and data spaces.
5667 We integrated changes to support the 29k UDI (Universal Debugger
5668 Interface), but discovered at the last minute that we didn't have all
5669 of the appropriate copyright paperwork. We are working with AMD to
5670 resolve this, and hope to have it available soon.
5674 We have sped up the remote serial line protocol, especially for targets
5675 with lots of registers. It now supports a new `expedited status' ('T')
5676 message which can be used in place of the existing 'S' status message.
5677 This allows the remote stub to send only the registers that GDB
5678 needs to make a quick decision about single-stepping or conditional
5679 breakpoints, eliminating the need to fetch the entire register set for
5680 each instruction being stepped through.
5682 The GDB remote serial protocol now implements a write-through cache for
5683 registers, only re-reading the registers if the target has run.
5685 There is also a new remote serial stub for SPARC processors. You can
5686 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5687 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5688 processor with a serial port.
5692 Configure.in files have become much easier to read and modify. A new
5693 `table driven' format makes it more obvious what configurations are
5694 supported, and what files each one uses.
5698 There is a new opcodes library which will eventually contain all of the
5699 disassembly routines and opcode tables. At present, it only contains
5700 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5701 disassembler (binutils/objdump) to share these routines.
5703 The libiberty library is now copylefted under the GNU Library General
5704 Public License. This allows more liberal use, and was done so libg++
5705 can use it. This makes no difference to GDB, since the Library License
5706 grants all the rights from the General Public License.
5710 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5711 reference to the stabs symbol info used by the debugger. It is (as far
5712 as we know) the only published document on this fascinating topic. We
5713 encourage you to read it, compare it to the stabs information on your
5714 system, and send improvements on the document in general (to
5715 bug-gdb@prep.ai.mit.edu).
5717 And, of course, many bugs have been fixed.
5720 *** Changes in GDB-4.6:
5722 * Better support for C++ function names
5724 GDB now accepts as input the "demangled form" of C++ overloaded function
5725 names and member function names, and can do command completion on such names
5726 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5727 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5728 Make use of command completion, it is your friend.
5730 GDB also now accepts a variety of C++ mangled symbol formats. They are
5731 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5732 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5733 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5734 for the list of formats.
5736 * G++ symbol mangling problem
5738 Recent versions of gcc have a bug in how they emit debugging information for
5739 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5740 directory) can be applied to gcc to fix the problem. Alternatively, if you
5741 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5742 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5743 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5746 * New 'maintenance' command
5748 All of the commands related to hacking GDB internals have been moved out of
5749 the main command set, and now live behind the 'maintenance' command. This
5750 can also be abbreviated as 'mt'. The following changes were made:
5752 dump-me -> maintenance dump-me
5753 info all-breakpoints -> maintenance info breakpoints
5754 printmsyms -> maintenance print msyms
5755 printobjfiles -> maintenance print objfiles
5756 printpsyms -> maintenance print psymbols
5757 printsyms -> maintenance print symbols
5759 The following commands are new:
5761 maintenance demangle Call internal GDB demangler routine to
5762 demangle a C++ link name and prints the result.
5763 maintenance print type Print a type chain for a given symbol
5765 * Change to .gdbinit file processing
5767 We now read the $HOME/.gdbinit file before processing the argv arguments
5768 (e.g. reading symbol files or core files). This allows global parameters to
5769 be set, which will apply during the symbol reading. The ./.gdbinit is still
5770 read after argv processing.
5772 * New hosts supported
5774 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5776 GNU/Linux support i386-unknown-linux or linux
5778 We are also including code to support the HP/PA running BSD and HPUX. This
5779 is almost guaranteed not to work, as we didn't have time to test or build it
5780 for this release. We are including it so that the more adventurous (or
5781 masochistic) of you can play with it. We also had major problems with the
5782 fact that the compiler that we got from HP doesn't support the -g option.
5785 * New targets supported
5787 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5789 * More smarts about finding #include files
5791 GDB now remembers the compilation directory for all include files, and for
5792 all files from which C is generated (like yacc and lex sources). This
5793 greatly improves GDB's ability to find yacc/lex sources, and include files,
5794 especially if you are debugging your program from a directory different from
5795 the one that contains your sources.
5797 We also fixed a bug which caused difficulty with listing and setting
5798 breakpoints in include files which contain C code. (In the past, you had to
5799 try twice in order to list an include file that you hadn't looked at before.)
5801 * Interesting infernals change
5803 GDB now deals with arbitrary numbers of sections, where the symbols for each
5804 section must be relocated relative to that section's landing place in the
5805 target's address space. This work was needed to support ELF with embedded
5806 stabs used by Solaris-2.0.
5808 * Bug fixes (of course!)
5810 There have been loads of fixes for the following things:
5811 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5812 i960, stabs, DOS(GO32), procfs, etc...
5814 See the ChangeLog for details.
5816 *** Changes in GDB-4.5:
5818 * New machines supported (host and target)
5820 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5822 SGI Irix-4.x mips-sgi-irix4 or iris4
5824 * New malloc package
5826 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5827 Mmalloc is capable of handling mutiple heaps of memory. It is also
5828 capable of saving a heap to a file, and then mapping it back in later.
5829 This can be used to greatly speedup the startup of GDB by using a
5830 pre-parsed symbol table which lives in a mmalloc managed heap. For
5831 more details, please read mmalloc/mmalloc.texi.
5835 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5836 'help info proc' for details.
5838 * MIPS ecoff symbol table format
5840 The code that reads MIPS symbol table format is now supported on all hosts.
5841 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5844 * File name changes for MS-DOS
5846 Many files in the config directories have been renamed to make it easier to
5847 support GDB on MS-DOSe systems (which have very restrictive file name
5848 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5849 environment) is close to working but has some remaining problems. Note
5850 that debugging of DOS programs is not supported, due to limitations
5851 in the ``operating system'', but it can be used to host cross-debugging.
5853 * Cross byte order fixes
5855 Many fixes have been made to support cross debugging of Sparc and MIPS
5856 targets from hosts whose byte order differs.
5858 * New -mapped and -readnow options
5860 If memory-mapped files are available on your system through the 'mmap'
5861 system call, you can use the -mapped option on the `file' or
5862 `symbol-file' commands to cause GDB to write the symbols from your
5863 program into a reusable file. If the program you are debugging is
5864 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5865 Future GDB debugging sessions will notice the presence of this file,
5866 and will quickly map in symbol information from it, rather than reading
5867 the symbol table from the executable program. Using the '-mapped'
5868 option in a GDB `file' or `symbol-file' command has the same effect as
5869 starting GDB with the '-mapped' command-line option.
5871 You can cause GDB to read the entire symbol table immediately by using
5872 the '-readnow' option with any of the commands that load symbol table
5873 information (or on the GDB command line). This makes the command
5874 slower, but makes future operations faster.
5876 The -mapped and -readnow options are typically combined in order to
5877 build a `fred.syms' file that contains complete symbol information.
5878 A simple GDB invocation to do nothing but build a `.syms' file for future
5881 gdb -batch -nx -mapped -readnow programname
5883 The `.syms' file is specific to the host machine on which GDB is run.
5884 It holds an exact image of GDB's internal symbol table. It cannot be
5885 shared across multiple host platforms.
5887 * longjmp() handling
5889 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5890 siglongjmp() without losing control. This feature has not yet been ported to
5891 all systems. It currently works on many 386 platforms, all MIPS-based
5892 platforms (SGI, DECstation, etc), and Sun3/4.
5896 Preliminary work has been put in to support the new Solaris OS from Sun. At
5897 this time, it can control and debug processes, but it is not capable of
5902 As always, many many bug fixes. The major areas were with g++, and mipsread.
5903 People using the MIPS-based platforms should experience fewer mysterious
5904 crashes and trashed symbol tables.
5906 *** Changes in GDB-4.4:
5908 * New machines supported (host and target)
5910 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5912 BSD Reno on Vax vax-dec-bsd
5913 Ultrix on Vax vax-dec-ultrix
5915 * New machines supported (target)
5917 AMD 29000 embedded, using EBMON a29k-none-none
5921 GDB continues to improve its handling of C++. `References' work better.
5922 The demangler has also been improved, and now deals with symbols mangled as
5923 per the Annotated C++ Reference Guide.
5925 GDB also now handles `stabs' symbol information embedded in MIPS
5926 `ecoff' symbol tables. Since the ecoff format was not easily
5927 extensible to handle new languages such as C++, this appeared to be a
5928 good way to put C++ debugging info into MIPS binaries. This option
5929 will be supported in the GNU C compiler, version 2, when it is
5932 * New features for SVR4
5934 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5935 shared libraries. Debugging dynamically linked programs should present
5936 only minor differences from debugging statically linked programs.
5938 The `info proc' command will print out information about any process
5939 on an SVR4 system (including the one you are debugging). At the moment,
5940 it prints the address mappings of the process.
5942 If you bring up GDB on another SVR4 system, please send mail to
5943 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5945 * Better dynamic linking support in SunOS
5947 Reading symbols from shared libraries which contain debugging symbols
5948 now works properly. However, there remain issues such as automatic
5949 skipping of `transfer vector' code during function calls, which
5950 make it harder to debug code in a shared library, than to debug the
5951 same code linked statically.
5955 GDB is now using the latest `getopt' routines from the FSF. This
5956 version accepts the -- prefix for options with long names. GDB will
5957 continue to accept the old forms (-option and +option) as well.
5958 Various single letter abbreviations for options have been explicity
5959 added to the option table so that they won't get overshadowed in the
5960 future by other options that begin with the same letter.
5964 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5965 Many assorted bugs have been handled. Many more remain to be handled.
5966 See the various ChangeLog files (primarily in gdb and bfd) for details.
5969 *** Changes in GDB-4.3:
5971 * New machines supported (host and target)
5973 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5974 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5975 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5977 * Almost SCO Unix support
5979 We had hoped to support:
5980 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5981 (except for core file support), but we discovered very late in the release
5982 that it has problems with process groups that render gdb unusable. Sorry
5983 about that. I encourage people to fix it and post the fixes.
5985 * Preliminary ELF and DWARF support
5987 GDB can read ELF object files on System V Release 4, and can handle
5988 debugging records for C, in DWARF format, in ELF files. This support
5989 is preliminary. If you bring up GDB on another SVR4 system, please
5990 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5995 GDB now uses the latest `readline' library. One user-visible change
5996 is that two tabs will list possible command completions, which previously
5997 required typing M-? (meta-question mark, or ESC ?).
6001 The `stepi' bug that many of you noticed has been squashed.
6002 Many bugs in C++ have been handled. Many more remain to be handled.
6003 See the various ChangeLog files (primarily in gdb and bfd) for details.
6005 * State of the MIPS world (in case you wondered):
6007 GDB can understand the symbol tables emitted by the compilers
6008 supplied by most vendors of MIPS-based machines, including DEC. These
6009 symbol tables are in a format that essentially nobody else uses.
6011 Some versions of gcc come with an assembler post-processor called
6012 mips-tfile. This program is required if you want to do source-level
6013 debugging of gcc-compiled programs. I believe FSF does not ship
6014 mips-tfile with gcc version 1, but it will eventually come with gcc
6017 Debugging of g++ output remains a problem. g++ version 1.xx does not
6018 really support it at all. (If you're lucky, you should be able to get
6019 line numbers and stack traces to work, but no parameters or local
6020 variables.) With some work it should be possible to improve the
6023 When gcc version 2 is released, you will have somewhat better luck.
6024 However, even then you will get confusing results for inheritance and
6027 We will eventually provide full debugging of g++ output on
6028 DECstations. This will probably involve some kind of stabs-in-ecoff
6029 encapulation, but the details have not been worked out yet.
6032 *** Changes in GDB-4.2:
6034 * Improved configuration
6036 Only one copy of `configure' exists now, and it is not self-modifying.
6037 Porting BFD is simpler.
6041 The `step' and `next' commands now only stop at the first instruction
6042 of a source line. This prevents the multiple stops that used to occur
6043 in switch statements, for-loops, etc. `Step' continues to stop if a
6044 function that has debugging information is called within the line.
6048 Lots of small bugs fixed. More remain.
6050 * New host supported (not target)
6052 Intel 386 PC clone running Mach i386-none-mach
6055 *** Changes in GDB-4.1:
6057 * Multiple source language support
6059 GDB now has internal scaffolding to handle several source languages.
6060 It determines the type of each source file from its filename extension,
6061 and will switch expression parsing and number formatting to match the
6062 language of the function in the currently selected stack frame.
6063 You can also specifically set the language to be used, with
6064 `set language c' or `set language modula-2'.
6068 GDB now has preliminary support for the GNU Modula-2 compiler,
6069 currently under development at the State University of New York at
6070 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6071 continue through the fall of 1991 and into 1992.
6073 Other Modula-2 compilers are currently not supported, and attempting to
6074 debug programs compiled with them will likely result in an error as the
6075 symbol table is read. Feel free to work on it, though!
6077 There are hooks in GDB for strict type checking and range checking,
6078 in the `Modula-2 philosophy', but they do not currently work.
6082 GDB can now write to executable and core files (e.g. patch
6083 a variable's value). You must turn this switch on, specify
6084 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6085 by assigning a new value to a variable. Modifications take
6088 * Automatic SunOS shared library reading
6090 When you run your program, GDB automatically determines where its
6091 shared libraries (if any) have been loaded, and reads their symbols.
6092 The `share' command is no longer needed. This also works when
6093 examining core files.
6097 You can specify the number of lines that the `list' command shows.
6100 * New machines supported (host and target)
6102 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6103 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6104 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6106 * New hosts supported (not targets)
6108 IBM RT/PC: romp-ibm-aix or rtpc
6110 * New targets supported (not hosts)
6112 AMD 29000 embedded with COFF a29k-none-coff
6113 AMD 29000 embedded with a.out a29k-none-aout
6114 Ultracomputer remote kernel debug a29k-nyu-kern
6116 * New remote interfaces
6122 *** Changes in GDB-4.0:
6126 Wide output is wrapped at good places to make the output more readable.
6128 Gdb now supports cross-debugging from a host machine of one type to a
6129 target machine of another type. Communication with the target system
6130 is over serial lines. The ``target'' command handles connecting to the
6131 remote system; the ``load'' command will download a program into the
6132 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6133 also supports debugging of realtime processes running under VxWorks,
6134 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6135 stub on the target system.
6137 New CPUs supported include the AMD 29000 and Intel 960.
6139 GDB now reads object files and symbol tables via a ``binary file''
6140 library, which allows a single copy of GDB to debug programs of multiple
6141 object file types such as a.out and coff.
6143 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6144 refcard.dvi and refcard.ps are available to format it).
6147 * Control-Variable user interface simplified
6149 All variables that control the operation of the debugger can be set
6150 by the ``set'' command, and displayed by the ``show'' command.
6152 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6153 ``Show prompt'' produces the response:
6154 Gdb's prompt is new-gdb=>.
6156 What follows are the NEW set commands. The command ``help set'' will
6157 print a complete list of old and new set commands. ``help set FOO''
6158 will give a longer description of the variable FOO. ``show'' will show
6159 all of the variable descriptions and their current settings.
6161 confirm on/off: Enables warning questions for operations that are
6162 hard to recover from, e.g. rerunning the program while
6163 it is already running. Default is ON.
6165 editing on/off: Enables EMACS style command line editing
6166 of input. Previous lines can be recalled with
6167 control-P, the current line can be edited with control-B,
6168 you can search for commands with control-R, etc.
6171 history filename NAME: NAME is where the gdb command history
6172 will be stored. The default is .gdb_history,
6173 or the value of the environment variable
6176 history size N: The size, in commands, of the command history. The
6177 default is 256, or the value of the environment variable
6180 history save on/off: If this value is set to ON, the history file will
6181 be saved after exiting gdb. If set to OFF, the
6182 file will not be saved. The default is OFF.
6184 history expansion on/off: If this value is set to ON, then csh-like
6185 history expansion will be performed on
6186 command line input. The default is OFF.
6188 radix N: Sets the default radix for input and output. It can be set
6189 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6190 in the current radix, so "set radix 10" is always a no-op.
6192 height N: This integer value is the number of lines on a page. Default
6193 is 24, the current `stty rows'' setting, or the ``li#''
6194 setting from the termcap entry matching the environment
6197 width N: This integer value is the number of characters on a line.
6198 Default is 80, the current `stty cols'' setting, or the ``co#''
6199 setting from the termcap entry matching the environment
6202 Note: ``set screensize'' is obsolete. Use ``set height'' and
6203 ``set width'' instead.
6205 print address on/off: Print memory addresses in various command displays,
6206 such as stack traces and structure values. Gdb looks
6207 more ``symbolic'' if you turn this off; it looks more
6208 ``machine level'' with it on. Default is ON.
6210 print array on/off: Prettyprint arrays. New convenient format! Default
6213 print demangle on/off: Print C++ symbols in "source" form if on,
6216 print asm-demangle on/off: Same, for assembler level printouts
6219 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6222 * Support for Epoch Environment.
6224 The epoch environment is a version of Emacs v18 with windowing. One
6225 new command, ``inspect'', is identical to ``print'', except that if you
6226 are running in the epoch environment, the value is printed in its own
6230 * Support for Shared Libraries
6232 GDB can now debug programs and core files that use SunOS shared libraries.
6233 Symbols from a shared library cannot be referenced
6234 before the shared library has been linked with the program (this
6235 happens after you type ``run'' and before the function main() is entered).
6236 At any time after this linking (including when examining core files
6237 from dynamically linked programs), gdb reads the symbols from each
6238 shared library when you type the ``sharedlibrary'' command.
6239 It can be abbreviated ``share''.
6241 sharedlibrary REGEXP: Load shared object library symbols for files
6242 matching a unix regular expression. No argument
6243 indicates to load symbols for all shared libraries.
6245 info sharedlibrary: Status of loaded shared libraries.
6250 A watchpoint stops execution of a program whenever the value of an
6251 expression changes. Checking for this slows down execution
6252 tremendously whenever you are in the scope of the expression, but is
6253 quite useful for catching tough ``bit-spreader'' or pointer misuse
6254 problems. Some machines such as the 386 have hardware for doing this
6255 more quickly, and future versions of gdb will use this hardware.
6257 watch EXP: Set a watchpoint (breakpoint) for an expression.
6259 info watchpoints: Information about your watchpoints.
6261 delete N: Deletes watchpoint number N (same as breakpoints).
6262 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6263 enable N: Re-enables watchpoint number N (same as breakpoints).
6266 * C++ multiple inheritance
6268 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6271 * C++ exception handling
6273 Gdb now supports limited C++ exception handling. Besides the existing
6274 ability to breakpoint on an exception handler, gdb can breakpoint on
6275 the raising of an exception (before the stack is peeled back to the
6278 catch FOO: If there is a FOO exception handler in the dynamic scope,
6279 set a breakpoint to catch exceptions which may be raised there.
6280 Multiple exceptions (``catch foo bar baz'') may be caught.
6282 info catch: Lists all exceptions which may be caught in the
6283 current stack frame.
6286 * Minor command changes
6288 The command ``call func (arg, arg, ...)'' now acts like the print
6289 command, except it does not print or save a value if the function's result
6290 is void. This is similar to dbx usage.
6292 The ``up'' and ``down'' commands now always print the frame they end up
6293 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6294 frames without printing.
6296 * New directory command
6298 'dir' now adds directories to the FRONT of the source search path.
6299 The path starts off empty. Source files that contain debug information
6300 about the directory in which they were compiled can be found even
6301 with an empty path; Sun CC and GCC include this information. If GDB can't
6302 find your source file in the current directory, type "dir .".
6304 * Configuring GDB for compilation
6306 For normal use, type ``./configure host''. See README or gdb.texinfo
6309 GDB now handles cross debugging. If you are remotely debugging between
6310 two different machines, type ``./configure host -target=targ''.
6311 Host is the machine where GDB will run; targ is the machine
6312 where the program that you are debugging will run.