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.
31 * In Ada, the overloads selection menu has been enhanced to display the
32 parameter types and the return types for the matching overloaded subprograms.
36 maint set target-non-stop (on|off|auto)
37 maint show target-non-stop
38 Control whether GDB targets always operate in non-stop mode even if
39 "set non-stop" is "off". The default is "auto", meaning non-stop
40 mode is enabled if supported by the target.
43 maint show bfd-sharing
44 Control the reuse of bfd objects.
48 Control display of debugging info regarding bfd caching.
50 set remote multiprocess-extensions-packet
51 show remote multiprocess-extensions-packet
52 Set/show the use of the remote protocol multiprocess extensions.
54 set remote thread-events
55 show remote thread-events
56 Set/show the use of thread create/exit events.
58 set ada print-signatures on|off
59 show ada print-signatures"
60 Control whether parameter types and return types are displayed in overloads
61 selection menus. It is activaled (@code{on}) by default.
63 * The "disassemble" command accepts a new modifier: /s.
64 It prints mixed source+disassembly like /m with two differences:
65 - disassembled instructions are now printed in program order, and
66 - and source for all relevant files is now printed.
67 The "/m" option is now considered deprecated: its "source-centric"
68 output hasn't proved useful in practice.
70 * The "record instruction-history" command accepts a new modifier: /s.
71 It behaves exactly like /m and prints mixed source+disassembly.
73 * The "set scheduler-locking" command supports a new mode "replay".
74 It behaves like "off" in record mode and like "on" in replay mode.
76 * Support for various ROM monitors has been removed:
78 target dbug dBUG ROM monitor for Motorola ColdFire
79 target picobug Motorola picobug monitor
80 target dink32 DINK32 ROM monitor for PowerPC
81 target m32r Renesas M32R/D ROM monitor
82 target mon2000 mon2000 ROM monitor
83 target ppcbug PPCBUG ROM monitor for PowerPC
85 * Support for reading/writing memory and extracting values on architectures
86 whose memory is addressable in units of any integral multiple of 8 bits.
91 Indicates that an exec system call was executed.
93 exec-events feature in qSupported
94 The qSupported packet allows GDB to request support for exec
95 events using the new 'gdbfeature' exec-event, and the qSupported
96 response can contain the corresponding 'stubfeature'. Set and
97 show commands can be used to display whether these features are enabled.
100 Equivalent to interrupting with the ^C character, but works in
103 thread created stop reason (T05 create:...)
104 Indicates that the thread was just created and is stopped at entry.
106 thread exit stop reply (w exitcode;tid)
107 Indicates that the thread has terminated.
110 Enables/disables thread create and exit event reporting. For
111 example, this is used in non-stop mode when GDB stops a set of
112 threads and synchronously waits for the their corresponding stop
113 replies. Without exit events, if one of the threads exits, GDB
114 would hang forever not knowing that it should no longer expect a
115 stop for that same thread.
119 Indicates that there are no resumed threads left in the target (all
120 threads are stopped). The remote stub reports support for this stop
121 reply to GDB's qSupported query.
123 * Extended-remote exec events
125 ** GDB now has support for exec events on extended-remote Linux targets.
126 For such targets with Linux kernels 2.5.46 and later, this enables
127 follow-exec-mode and exec catchpoints.
129 set remote exec-event-feature-packet
130 show remote exec-event-feature-packet
131 Set/show the use of the remote exec event feature.
133 * Thread names in remote protocol
135 The reply to qXfer:threads:read may now include a name attribute for each
138 *** Changes in GDB 7.10
140 * Support for process record-replay and reverse debugging on aarch64*-linux*
141 targets has been added. GDB now supports recording of A64 instruction set
142 including advance SIMD instructions.
144 * Support for Sun's version of the "stabs" debug file format has been removed.
146 * GDB now honors the content of the file /proc/PID/coredump_filter
147 (PID is the process ID) on GNU/Linux systems. This file can be used
148 to specify the types of memory mappings that will be included in a
149 corefile. For more information, please refer to the manual page of
150 "core(5)". GDB also has a new command: "set use-coredump-filter
151 on|off". It allows to set whether GDB will read the content of the
152 /proc/PID/coredump_filter file when generating a corefile.
154 * The "info os" command on GNU/Linux can now display information on
156 "info os cpus" Listing of all cpus/cores on the system
158 * GDB has two new commands: "set serial parity odd|even|none" and
159 "show serial parity". These allows to set or show parity for the
162 * The "info source" command now displays the producer string if it was
163 present in the debug info. This typically includes the compiler version
164 and may include things like its command line arguments.
166 * The "info dll", an alias of the "info sharedlibrary" command,
167 is now available on all platforms.
169 * Directory names supplied to the "set sysroot" commands may be
170 prefixed with "target:" to tell GDB to access shared libraries from
171 the target system, be it local or remote. This replaces the prefix
172 "remote:". The default sysroot has been changed from "" to
173 "target:". "remote:" is automatically converted to "target:" for
174 backward compatibility.
176 * The system root specified by "set sysroot" will be prepended to the
177 filename of the main executable (if reported to GDB as absolute by
178 the operating system) when starting processes remotely, and when
179 attaching to already-running local or remote processes.
181 * GDB now supports automatic location and retrieval of executable
182 files from remote targets. Remote debugging can now be initiated
183 using only a "target remote" or "target extended-remote" command
184 (no "set sysroot" or "file" commands are required). See "New remote
187 * The "dump" command now supports verilog hex format.
189 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
191 * On GNU/Linux, GDB and gdbserver are now able to access executable
192 and shared library files without a "set sysroot" command when
193 attaching to processes running in different mount namespaces from
194 the debugger. This makes it possible to attach to processes in
195 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
196 See "New remote packets" below.
198 * The "tui reg" command now provides completion for all of the
199 available register groups, including target specific groups.
201 * The HISTSIZE environment variable is no longer read when determining
202 the size of GDB's command history. GDB now instead reads the dedicated
203 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
204 disables truncation of command history. Non-numeric values of GDBHISTSIZE
209 ** Memory ports can now be unbuffered.
213 ** gdb.Objfile objects have a new attribute "username",
214 which is the name of the objfile as specified by the user,
215 without, for example, resolving symlinks.
216 ** You can now write frame unwinders in Python.
217 ** gdb.Type objects have a new method "optimized_out",
218 returning optimized out gdb.Value instance of this type.
219 ** gdb.Value objects have new methods "reference_value" and
220 "const_value" which return a reference to the value and a
221 "const" version of the value respectively.
225 maint print symbol-cache
226 Print the contents of the symbol cache.
228 maint print symbol-cache-statistics
229 Print statistics of symbol cache usage.
231 maint flush-symbol-cache
232 Flush the contents of the symbol cache.
236 Start branch trace recording using Branch Trace Store (BTS) format.
239 Evaluate expression by using the compiler and print result.
243 Explicit commands for enabling and disabling tui mode.
246 set mpx bound on i386 and amd64
247 Support for bound table investigation on Intel(R) MPX enabled applications.
251 Start branch trace recording using Intel(R) Processor Trace format.
254 Print information about branch tracing internals.
256 maint btrace packet-history
257 Print the raw branch tracing data.
259 maint btrace clear-packet-history
260 Discard the stored raw branch tracing data.
263 Discard all branch tracing data. It will be fetched and processed
264 anew by the next "record" command.
269 Renamed from "set debug dwarf2-die".
271 Renamed from "show debug dwarf2-die".
274 Renamed from "set debug dwarf2-read".
275 show debug dwarf-read
276 Renamed from "show debug dwarf2-read".
278 maint set dwarf always-disassemble
279 Renamed from "maint set dwarf2 always-disassemble".
280 maint show dwarf always-disassemble
281 Renamed from "maint show dwarf2 always-disassemble".
283 maint set dwarf max-cache-age
284 Renamed from "maint set dwarf2 max-cache-age".
285 maint show dwarf max-cache-age
286 Renamed from "maint show dwarf2 max-cache-age".
289 show debug dwarf-line
290 Control display of debugging info regarding DWARF line processing.
294 Set the maximum number of candidates to be considered during
295 completion. The default value is 200. This limit allows GDB
296 to avoid generating large completion lists, the computation of
297 which can cause the debugger to become temporarily unresponsive.
299 set history remove-duplicates
300 show history remove-duplicates
301 Control the removal of duplicate history entries.
303 maint set symbol-cache-size
304 maint show symbol-cache-size
305 Control the size of the symbol cache.
307 set|show record btrace bts buffer-size
308 Set and show the size of the ring buffer used for branch tracing in
310 The obtained size may differ from the requested size. Use "info
311 record" to see the obtained buffer size.
313 set debug linux-namespaces
314 show debug linux-namespaces
315 Control display of debugging info regarding Linux namespaces.
317 set|show record btrace pt buffer-size
318 Set and show the size of the ring buffer used for branch tracing in
319 Intel(R) Processor Trace format.
320 The obtained size may differ from the requested size. Use "info
321 record" to see the obtained buffer size.
323 maint set|show btrace pt skip-pad
324 Set and show whether PAD packets are skipped when computing the
327 * The command 'thread apply all' can now support new option '-ascending'
328 to call its specified command for all threads in ascending order.
330 * Python/Guile scripting
332 ** GDB now supports auto-loading of Python/Guile scripts contained in the
333 special section named `.debug_gdb_scripts'.
337 qXfer:btrace-conf:read
338 Return the branch trace configuration for the current thread.
340 Qbtrace-conf:bts:size
341 Set the requested ring buffer size for branch tracing in BTS format.
344 Enable Intel(R) Procesor Trace-based branch tracing for the current
345 process. The remote stub reports support for this packet to GDB's
349 Set the requested ring buffer size for branch tracing in Intel(R) Processor
353 Indicates a memory breakpoint instruction was executed, irrespective
354 of whether it was GDB that planted the breakpoint or the breakpoint
355 is hardcoded in the program. This is required for correct non-stop
359 Indicates the target stopped for a hardware breakpoint. This is
360 required for correct non-stop mode operation.
363 Return information about files on the remote system.
366 Return the full absolute name of the file that was executed to
367 create a process running on the remote system.
370 Select the filesystem on which vFile: operations with filename
371 arguments will operate. This is required for GDB to be able to
372 access files on remote targets where the remote stub does not
373 share a common filesystem with the inferior(s).
376 Indicates that a fork system call was executed.
379 Indicates that a vfork system call was executed.
381 vforkdone stop reason
382 Indicates that a vfork child of the specified process has executed
383 an exec or exit, allowing the vfork parent to resume execution.
385 fork-events and vfork-events features in qSupported
386 The qSupported packet allows GDB to request support for fork and
387 vfork events using new 'gdbfeatures' fork-events and vfork-events,
388 and the qSupported response can contain the corresponding
389 'stubfeatures'. Set and show commands can be used to display
390 whether these features are enabled.
392 * Extended-remote fork events
394 ** GDB now has support for fork events on extended-remote Linux
395 targets. For targets with Linux kernels 2.5.60 and later, this
396 enables follow-fork-mode and detach-on-fork for both fork and
397 vfork, as well as fork and vfork catchpoints.
399 * The info record command now shows the recording format and the
400 branch tracing configuration for the current thread when using
401 the btrace record target.
402 For the BTS format, it shows the ring buffer size.
404 * GDB now has support for DTrace USDT (Userland Static Defined
405 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
407 * GDB now supports access to vector registers on S/390 GNU/Linux
410 * Removed command line options
412 -xdb HP-UX XDB compatibility mode.
414 * Removed targets and native configurations
416 HP/PA running HP-UX hppa*-*-hpux*
417 Itanium running HP-UX ia64-*-hpux*
419 * New configure options
422 This configure option allows the user to build GDB with support for
423 Intel(R) Processor Trace (default: auto). This requires libipt.
425 --with-libipt-prefix=PATH
426 Specify the path to the version of libipt that GDB should use.
427 $PATH/include should contain the intel-pt.h header and
428 $PATH/lib should contain the libipt.so library.
430 *** Changes in GDB 7.9.1
434 ** Xmethods can now specify a result type.
436 *** Changes in GDB 7.9
438 * GDB now supports hardware watchpoints on x86 GNU Hurd.
442 ** You can now access frame registers from Python scripts.
443 ** New attribute 'producer' for gdb.Symtab objects.
444 ** gdb.Objfile objects have a new attribute "progspace",
445 which is the gdb.Progspace object of the containing program space.
446 ** gdb.Objfile objects have a new attribute "owner".
447 ** gdb.Objfile objects have a new attribute "build_id",
448 which is the build ID generated when the file was built.
449 ** gdb.Objfile objects have a new method "add_separate_debug_file".
450 ** A new event "gdb.clear_objfiles" has been added, triggered when
451 selecting a new file to debug.
452 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
453 ** New function gdb.lookup_objfile.
455 New events which are triggered when GDB modifies the state of the
458 ** gdb.events.inferior_call_pre: Function call is about to be made.
459 ** gdb.events.inferior_call_post: Function call has just been made.
460 ** gdb.events.memory_changed: A memory location has been altered.
461 ** gdb.events.register_changed: A register has been altered.
463 * New Python-based convenience functions:
465 ** $_caller_is(name [, number_of_frames])
466 ** $_caller_matches(regexp [, number_of_frames])
467 ** $_any_caller_is(name [, number_of_frames])
468 ** $_any_caller_matches(regexp [, number_of_frames])
470 * GDB now supports the compilation and injection of source code into
471 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
472 to compile the source code to object code, and if successful, inject
473 and execute that code within the current context of the inferior.
474 Currently the C language is supported. The commands used to
475 interface with this new feature are:
477 compile code [-raw|-r] [--] [source code]
478 compile file [-raw|-r] filename
482 demangle [-l language] [--] name
483 Demangle "name" in the specified language, or the current language
484 if elided. This command is renamed from the "maint demangle" command.
485 The latter is kept as a no-op to avoid "maint demangle" being interpreted
486 as "maint demangler-warning".
488 queue-signal signal-name-or-number
489 Queue a signal to be delivered to the thread when it is resumed.
491 add-auto-load-scripts-directory directory
492 Add entries to the list of directories from which to load auto-loaded
495 maint print user-registers
496 List all currently available "user" registers.
498 compile code [-r|-raw] [--] [source code]
499 Compile, inject, and execute in the inferior the executable object
500 code produced by compiling the provided source code.
502 compile file [-r|-raw] filename
503 Compile and inject into the inferior the executable object code
504 produced by compiling the source code stored in the filename
507 * On resume, GDB now always passes the signal the program had stopped
508 for to the thread the signal was sent to, even if the user changed
509 threads before resuming. Previously GDB would often (but not
510 always) deliver the signal to the thread that happens to be current
513 * Conversely, the "signal" command now consistently delivers the
514 requested signal to the current thread. GDB now asks for
515 confirmation if the program had stopped for a signal and the user
516 switched threads meanwhile.
518 * "breakpoint always-inserted" modes "off" and "auto" merged.
520 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
521 won't remove breakpoints from the target until all threads stop,
522 even in non-stop mode. The "auto" mode has been removed, and "off"
523 is now the default mode.
527 set debug symbol-lookup
528 show debug symbol-lookup
529 Control display of debugging info regarding symbol lookup.
533 ** The -list-thread-groups command outputs an exit-code field for
534 inferiors that have exited.
538 MIPS SDE mips*-sde*-elf*
542 Support for these obsolete configurations has been removed.
544 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
545 SGI Irix-5.x mips-*-irix5*
546 SGI Irix-6.x mips-*-irix6*
547 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
548 VAX running Ultrix vax-*-ultrix*
550 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
551 and "assf"), have been removed. Use the "sharedlibrary" command, or
552 its alias "share", instead.
554 *** Changes in GDB 7.8
556 * New command line options
559 This is an alias for the --data-directory option.
561 * GDB supports printing and modifying of variable length automatic arrays
562 as specified in ISO C99.
564 * The ARM simulator now supports instruction level tracing
565 with or without disassembly.
569 GDB now has support for scripting using Guile. Whether this is
570 available is determined at configure time.
571 Guile version 2.0 or greater is required.
572 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
574 * New commands (for set/show, see "New options" below)
578 Invoke CODE by passing it to the Guile interpreter.
582 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
584 info auto-load guile-scripts [regexp]
585 Print the list of automatically loaded Guile scripts.
587 * The source command is now capable of sourcing Guile scripts.
588 This feature is dependent on the debugger being built with Guile support.
592 set print symbol-loading (off|brief|full)
593 show print symbol-loading
594 Control whether to print informational messages when loading symbol
595 information for a file. The default is "full", but when debugging
596 programs with large numbers of shared libraries the amount of output
599 set guile print-stack (none|message|full)
600 show guile print-stack
601 Show a stack trace when an error is encountered in a Guile script.
603 set auto-load guile-scripts (on|off)
604 show auto-load guile-scripts
605 Control auto-loading of Guile script files.
607 maint ada set ignore-descriptive-types (on|off)
608 maint ada show ignore-descriptive-types
609 Control whether the debugger should ignore descriptive types in Ada
610 programs. The default is not to ignore the descriptive types. See
611 the user manual for more details on descriptive types and the intended
612 usage of this option.
614 set auto-connect-native-target
616 Control whether GDB is allowed to automatically connect to the
617 native target for the run, attach, etc. commands when not connected
618 to any target yet. See also "target native" below.
620 set record btrace replay-memory-access (read-only|read-write)
621 show record btrace replay-memory-access
622 Control what memory accesses are allowed during replay.
624 maint set target-async (on|off)
625 maint show target-async
626 This controls whether GDB targets operate in synchronous or
627 asynchronous mode. Normally the default is asynchronous, if it is
628 available; but this can be changed to more easily debug problems
629 occurring only in synchronous mode.
631 set mi-async (on|off)
633 Control whether MI asynchronous mode is preferred. This supersedes
634 "set target-async" of previous GDB versions.
636 * "set target-async" is deprecated as a CLI option and is now an alias
637 for "set mi-async" (only puts MI into async mode).
639 * Background execution commands (e.g., "c&", "s&", etc.) are now
640 possible ``out of the box'' if the target supports them. Previously
641 the user would need to explicitly enable the possibility with the
642 "set target-async on" command.
644 * New features in the GDB remote stub, GDBserver
646 ** New option --debug-format=option1[,option2,...] allows one to add
647 additional text to each output. At present only timestamps
648 are supported: --debug-format=timestamps.
649 Timestamps can also be turned on with the
650 "monitor set debug-format timestamps" command from GDB.
652 * The 'record instruction-history' command now starts counting instructions
653 at one. This also affects the instruction ranges reported by the
654 'record function-call-history' command when given the /i modifier.
656 * The command 'record function-call-history' supports a new modifier '/c' to
657 indent the function names based on their call stack depth.
658 The fields for the '/i' and '/l' modifier have been reordered.
659 The source line range is now prefixed with 'at'.
660 The instruction range is now prefixed with 'inst'.
661 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
662 "record instruction-history" and "list" commands.
664 * The ranges given as arguments to the 'record function-call-history' and
665 'record instruction-history' commands are now inclusive.
667 * The btrace record target now supports the 'record goto' command.
668 For locations inside the execution trace, the back trace is computed
669 based on the information stored in the execution trace.
671 * The btrace record target supports limited reverse execution and replay.
672 The target does not record data and therefore does not allow reading
675 * The "catch syscall" command now works on s390*-linux* targets.
677 * The "compare-sections" command is no longer specific to target
678 remote. It now works with all targets.
680 * All native targets are now consistently called "native".
681 Consequently, the "target child", "target GNU", "target djgpp",
682 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
683 commands have been replaced with "target native". The QNX/NTO port
684 leaves the "procfs" target in place and adds a "native" target for
685 consistency with other ports. The impact on users should be minimal
686 as these commands previously either throwed an error, or were
687 no-ops. The target's name is visible in the output of the following
688 commands: "help target", "info target", "info files", "maint print
691 * The "target native" command now connects to the native target. This
692 can be used to launch native programs even when "set
693 auto-connect-native-target" is set to off.
695 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.
697 * Support for Intel(R) AVX-512 registers on GNU/Linux.
698 Support displaying and modifying Intel(R) AVX-512 registers
699 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
703 qXfer:btrace:read's annex
704 The qXfer:btrace:read packet supports a new annex 'delta' to read
705 branch trace incrementally.
709 ** Valid Python operations on gdb.Value objects representing
710 structs/classes invoke the corresponding overloaded operators if
712 ** New `Xmethods' feature in the Python API. Xmethods are
713 additional methods or replacements for existing methods of a C++
714 class. This feature is useful for those cases where a method
715 defined in C++ source code could be inlined or optimized out by
716 the compiler, making it unavailable to GDB.
719 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
721 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
722 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
723 its alias "share", instead.
725 * The commands "set remotebaud" and "show remotebaud" are no longer
726 supported. Use "set serial baud" and "show serial baud" (respectively)
731 ** A new option "-gdb-set mi-async" replaces "-gdb-set
732 target-async". The latter is left as a deprecated alias of the
733 former for backward compatibility. If the target supports it,
734 CLI background execution commands are now always possible by
735 default, independently of whether the frontend stated a
736 preference for asynchronous execution with "-gdb-set mi-async".
737 Previously "-gdb-set target-async off" affected both MI execution
738 commands and CLI execution commands.
740 *** Changes in GDB 7.7
742 * Improved support for process record-replay and reverse debugging on
743 arm*-linux* targets. Support for thumb32 and syscall instruction
744 recording has been added.
746 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
748 * GDB now supports Fission DWP file format version 2.
749 http://gcc.gnu.org/wiki/DebugFission
751 * New convenience function "$_isvoid", to check whether an expression
752 is void. A void expression is an expression where the type of the
753 result is "void". For example, some convenience variables may be
754 "void" when evaluated (e.g., "$_exitcode" before the execution of
755 the program being debugged; or an undefined convenience variable).
756 Another example, when calling a function whose return type is
759 * The "maintenance print objfiles" command now takes an optional regexp.
761 * The "catch syscall" command now works on arm*-linux* targets.
763 * GDB now consistently shows "<not saved>" when printing values of
764 registers the debug info indicates have not been saved in the frame
765 and there's nowhere to retrieve them from
766 (callee-saved/call-clobbered registers):
771 (gdb) info registers rax
774 Before, the former would print "<optimized out>", and the latter
775 "*value not available*".
777 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
782 ** Frame filters and frame decorators have been added.
783 ** Temporary breakpoints are now supported.
784 ** Line tables representation has been added.
785 ** New attribute 'parent_type' for gdb.Field objects.
786 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
787 ** New attribute 'name' for gdb.Type objects.
791 Nios II ELF nios2*-*-elf
792 Nios II GNU/Linux nios2*-*-linux
793 Texas Instruments MSP430 msp430*-*-elf
795 * Removed native configurations
797 Support for these a.out NetBSD and OpenBSD obsolete configurations has
798 been removed. ELF variants of these configurations are kept supported.
800 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
801 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
802 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
803 i[34567]86-*-openbsd3.[0-3]
804 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
805 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
806 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
810 Like "catch throw", but catches a re-thrown exception.
812 Renamed from old "maint check-symtabs".
814 Perform consistency checks on symtabs.
816 Expand symtabs matching an optional regexp.
819 Display the details of GDB configure-time options.
821 maint set|show per-command
822 maint set|show per-command space
823 maint set|show per-command time
824 maint set|show per-command symtab
825 Enable display of per-command gdb resource usage.
827 remove-symbol-file FILENAME
828 remove-symbol-file -a ADDRESS
829 Remove a symbol file added via add-symbol-file. The file to remove
830 can be identified by its filename or by an address that lies within
831 the boundaries of this symbol file in memory.
834 info exceptions REGEXP
835 Display the list of Ada exceptions defined in the program being
836 debugged. If provided, only the exceptions whose names match REGEXP
841 set debug symfile off|on
843 Control display of debugging info regarding reading symbol files and
844 symbol tables within those files
846 set print raw frame-arguments
847 show print raw frame-arguments
848 Set/show whether to print frame arguments in raw mode,
849 disregarding any defined pretty-printers.
851 set remote trace-status-packet
852 show remote trace-status-packet
853 Set/show the use of remote protocol qTStatus packet.
857 Control display of debugging messages related to Nios II targets.
861 Control whether target-assisted range stepping is enabled.
863 set startup-with-shell
864 show startup-with-shell
865 Specifies whether Unix child processes are started via a shell or
870 Use the target memory cache for accesses to the code segment. This
871 improves performance of remote debugging (particularly disassembly).
873 * You can now use a literal value 'unlimited' for options that
874 interpret 0 or -1 as meaning "unlimited". E.g., "set
875 trace-buffer-size unlimited" is now an alias for "set
876 trace-buffer-size -1" and "set height unlimited" is now an alias for
879 * The "set debug symtab-create" debugging option of GDB has been changed to
880 accept a verbosity level. 0 means "off", 1 provides basic debugging
881 output, and values of 2 or greater provides more verbose output.
883 * New command-line options
885 Display the details of GDB configure-time options.
887 * The command 'tsave' can now support new option '-ctf' to save trace
888 buffer in Common Trace Format.
890 * Newly installed $prefix/bin/gcore acts as a shell interface for the
893 * GDB now implements the the C++ 'typeid' operator.
895 * The new convenience variable $_exception holds the exception being
896 thrown or caught at an exception-related catchpoint.
898 * The exception-related catchpoints, like "catch throw", now accept a
899 regular expression which can be used to filter exceptions by type.
901 * The new convenience variable $_exitsignal is automatically set to
902 the terminating signal number when the program being debugged dies
903 due to an uncaught signal.
907 ** All MI commands now accept an optional "--language" option.
908 Support for this feature can be verified by using the "-list-features"
909 command, which should contain "language-option".
911 ** The new command -info-gdb-mi-command allows the user to determine
912 whether a GDB/MI command is supported or not.
914 ** The "^error" result record returned when trying to execute an undefined
915 GDB/MI command now provides a variable named "code" whose content is the
916 "undefined-command" error code. Support for this feature can be verified
917 by using the "-list-features" command, which should contain
918 "undefined-command-error-code".
920 ** The -trace-save MI command can optionally save trace buffer in Common
923 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
925 ** The command -data-list-register-values now accepts an optional
926 "--skip-unavailable" option. When used, only the available registers
929 ** The new command -trace-frame-collected dumps collected variables,
930 computed expressions, tvars, memory and registers in a traceframe.
932 ** The commands -stack-list-locals, -stack-list-arguments and
933 -stack-list-variables now accept an option "--skip-unavailable".
934 When used, only the available locals or arguments are displayed.
936 ** The -exec-run command now accepts an optional "--start" option.
937 When used, the command follows the same semantics as the "start"
938 command, stopping the program's execution at the start of its
939 main subprogram. Support for this feature can be verified using
940 the "-list-features" command, which should contain
941 "exec-run-start-option".
943 ** The new commands -catch-assert and -catch-exceptions insert
944 catchpoints stopping the program when Ada exceptions are raised.
946 ** The new command -info-ada-exceptions provides the equivalent of
947 the new "info exceptions" command.
949 * New system-wide configuration scripts
950 A GDB installation now provides scripts suitable for use as system-wide
951 configuration scripts for the following systems:
955 * GDB now supports target-assigned range stepping with remote targets.
956 This improves the performance of stepping source lines by reducing
957 the number of control packets from/to GDB. See "New remote packets"
960 * GDB now understands the element 'tvar' in the XML traceframe info.
961 It has the id of the collected trace state variables.
963 * On S/390 targets that provide the transactional-execution feature,
964 the program interruption transaction diagnostic block (TDB) is now
965 represented as a number of additional "registers" in GDB.
971 The vCont packet supports a new 'r' action, that tells the remote
972 stub to step through an address range itself, without GDB
973 involvemement at each single-step.
975 qXfer:libraries-svr4:read's annex
976 The previously unused annex of the qXfer:libraries-svr4:read packet
977 is now used to support passing an argument list. The remote stub
978 reports support for this argument list to GDB's qSupported query.
979 The defined arguments are "start" and "prev", used to reduce work
980 necessary for library list updating, resulting in significant
983 * New features in the GDB remote stub, GDBserver
985 ** GDBserver now supports target-assisted range stepping. Currently
986 enabled on x86/x86_64 GNU/Linux targets.
988 ** GDBserver now adds element 'tvar' in the XML in the reply to
989 'qXfer:traceframe-info:read'. It has the id of the collected
990 trace state variables.
992 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
995 * New 'z' formatter for printing and examining memory, this displays the
996 value as hexadecimal zero padded on the left to the size of the type.
998 * GDB can now use Windows x64 unwinding data.
1000 * The "set remotebaud" command has been replaced by "set serial baud".
1001 Similarly, "show remotebaud" has been replaced by "show serial baud".
1002 The "set remotebaud" and "show remotebaud" commands are still available
1003 to provide backward compatibility with older versions of GDB.
1005 *** Changes in GDB 7.6
1007 * Target record has been renamed to record-full.
1008 Record/replay is now enabled with the "record full" command.
1009 This also affects settings that are associated with full record/replay
1010 that have been moved from "set/show record" to "set/show record full":
1012 set|show record full insn-number-max
1013 set|show record full stop-at-limit
1014 set|show record full memory-query
1016 * A new record target "record-btrace" has been added. The new target
1017 uses hardware support to record the control-flow of a process. It
1018 does not support replaying the execution, but it implements the
1019 below new commands for investigating the recorded execution log.
1020 This new recording method can be enabled using:
1024 The "record-btrace" target is only available on Intel Atom processors
1025 and requires a Linux kernel 2.6.32 or later.
1027 * Two new commands have been added for record/replay to give information
1028 about the recorded execution without having to replay the execution.
1029 The commands are only supported by "record btrace".
1031 record instruction-history prints the execution history at
1032 instruction granularity
1034 record function-call-history prints the execution history at
1035 function granularity
1037 * New native configurations
1039 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1040 FreeBSD/powerpc powerpc*-*-freebsd
1041 x86_64/Cygwin x86_64-*-cygwin*
1042 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1046 ARM AArch64 aarch64*-*-elf
1047 ARM AArch64 GNU/Linux aarch64*-*-linux
1048 Lynx 178 PowerPC powerpc-*-lynx*178
1049 x86_64/Cygwin x86_64-*-cygwin*
1050 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1052 * If the configured location of system.gdbinit file (as given by the
1053 --with-system-gdbinit option at configure time) is in the
1054 data-directory (as specified by --with-gdb-datadir at configure
1055 time) or in one of its subdirectories, then GDB will look for the
1056 system-wide init file in the directory specified by the
1057 --data-directory command-line option.
1059 * New command line options:
1061 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1062 other initialization files, unlike -nx which disables all of them.
1064 * Removed command line options
1066 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1069 * The 'ptype' and 'whatis' commands now accept an argument to control
1072 * 'info proc' now works on some core files.
1076 ** Vectors can be created with gdb.Type.vector.
1078 ** Python's atexit.register now works in GDB.
1080 ** Types can be pretty-printed via a Python API.
1082 ** Python 3 is now supported (in addition to Python 2.4 or later)
1084 ** New class gdb.Architecture exposes GDB's internal representation
1085 of architecture in the Python API.
1087 ** New method Frame.architecture returns the gdb.Architecture object
1088 corresponding to the frame's architecture.
1090 * New Python-based convenience functions:
1092 ** $_memeq(buf1, buf2, length)
1093 ** $_streq(str1, str2)
1095 ** $_regex(str, regex)
1097 * The 'cd' command now defaults to using '~' (the home directory) if not
1100 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1101 default for GCC since November 2000.
1103 * The command 'forward-search' can now be abbreviated as 'fo'.
1105 * The command 'info tracepoints' can now display 'installed on target'
1106 or 'not installed on target' for each non-pending location of tracepoint.
1108 * New configure options
1110 --enable-libmcheck/--disable-libmcheck
1111 By default, development versions are built with -lmcheck on hosts
1112 that support it, in order to help track memory corruption issues.
1113 Release versions, on the other hand, are built without -lmcheck
1114 by default. The --enable-libmcheck/--disable-libmcheck configure
1115 options allow the user to override that default.
1116 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1117 This configure option allows the user to build GDB with
1118 libbabeltrace using which GDB can read Common Trace Format data.
1120 * New commands (for set/show, see "New options" below)
1123 Catch signals. This is similar to "handle", but allows commands and
1124 conditions to be attached.
1127 List the BFDs known to GDB.
1129 python-interactive [command]
1131 Start a Python interactive prompt, or evaluate the optional command
1132 and print the result of expressions.
1135 "py" is a new alias for "python".
1137 enable type-printer [name]...
1138 disable type-printer [name]...
1139 Enable or disable type printers.
1143 ** For the Renesas Super-H architecture, the "regs" command has been removed
1144 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1149 set print type methods (on|off)
1150 show print type methods
1151 Control whether method declarations are displayed by "ptype".
1152 The default is to show them.
1154 set print type typedefs (on|off)
1155 show print type typedefs
1156 Control whether typedef definitions are displayed by "ptype".
1157 The default is to show them.
1159 set filename-display basename|relative|absolute
1160 show filename-display
1161 Control the way in which filenames is displayed.
1162 The default is "relative", which preserves previous behavior.
1164 set trace-buffer-size
1165 show trace-buffer-size
1166 Request target to change the size of trace buffer.
1168 set remote trace-buffer-size-packet auto|on|off
1169 show remote trace-buffer-size-packet
1170 Control the use of the remote protocol `QTBuffer:size' packet.
1174 Control display of debugging messages related to ARM AArch64.
1177 set debug coff-pe-read
1178 show debug coff-pe-read
1179 Control display of debugging messages related to reading of COFF/PE
1184 Control display of debugging messages related to Mach-O symbols
1187 set debug notification
1188 show debug notification
1189 Control display of debugging info for async remote notification.
1193 ** Command parameter changes are now notified using new async record
1194 "=cmd-param-changed".
1195 ** Trace frame changes caused by command "tfind" are now notified using
1196 new async record "=traceframe-changed".
1197 ** The creation, deletion and modification of trace state variables
1198 are now notified using new async records "=tsv-created",
1199 "=tsv-deleted" and "=tsv-modified".
1200 ** The start and stop of process record are now notified using new
1201 async record "=record-started" and "=record-stopped".
1202 ** Memory changes are now notified using new async record
1204 ** The data-disassemble command response will include a "fullname" field
1205 containing the absolute file name when source has been requested.
1206 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1207 command, to allow pattern filling of memory areas.
1208 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1209 library load/unload events.
1210 ** The response to breakpoint commands and breakpoint async records
1211 includes an "installed" field containing a boolean state about each
1212 non-pending tracepoint location is whether installed on target or not.
1213 ** Output of the "-trace-status" command includes a "trace-file" field
1214 containing the name of the trace file being examined. This field is
1215 optional, and only present when examining a trace file.
1216 ** The "fullname" field is now always present along with the "file" field,
1217 even if the file cannot be found by GDB.
1219 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1220 You must have the LZMA library available when configuring GDB for this
1221 feature to be enabled. For more information, see:
1222 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1224 * New remote packets
1227 Set the size of trace buffer. The remote stub reports support for this
1228 packet to gdb's qSupported query.
1231 Enable Branch Trace Store (BTS)-based branch tracing for the current
1232 thread. The remote stub reports support for this packet to gdb's
1236 Disable branch tracing for the current thread. The remote stub reports
1237 support for this packet to gdb's qSupported query.
1240 Read the traced branches for the current thread. The remote stub
1241 reports support for this packet to gdb's qSupported query.
1243 *** Changes in GDB 7.5
1245 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1246 for more x32 ABI info.
1248 * GDB now supports access to MIPS DSP registers on Linux targets.
1250 * GDB now supports debugging microMIPS binaries.
1252 * The "info os" command on GNU/Linux can now display information on
1253 several new classes of objects managed by the operating system:
1254 "info os procgroups" lists process groups
1255 "info os files" lists file descriptors
1256 "info os sockets" lists internet-domain sockets
1257 "info os shm" lists shared-memory regions
1258 "info os semaphores" lists semaphores
1259 "info os msg" lists message queues
1260 "info os modules" lists loaded kernel modules
1262 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1263 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1264 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1265 options and inspect the probe arguments using the new $_probe_arg family
1266 of convenience variables. You can obtain more information about SystemTap
1267 in <http://sourceware.org/systemtap/>.
1269 * GDB now supports reversible debugging on ARM, it allows you to
1270 debug basic ARM and THUMB instructions, and provides
1271 record/replay support.
1273 * The option "symbol-reloading" has been deleted as it is no longer used.
1277 ** GDB commands implemented in Python can now be put in command class
1280 ** The "maint set python print-stack on|off" is now deleted.
1282 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1283 apply "flag enum"-style pretty-printing to any enum.
1285 ** gdb.lookup_symbol can now work when there is no current frame.
1287 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1288 the source at which the symbol was defined.
1290 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1291 method 'value'. The former indicates whether the symbol needs a
1292 frame in order to compute its value, and the latter computes the
1295 ** A new method 'referenced_value' on gdb.Value objects which can
1296 dereference pointer as well as C++ reference values.
1298 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1299 which return the global and static blocks (as gdb.Block objects),
1300 of the underlying symbol table, respectively.
1302 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1303 object associated with a PC value.
1305 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1306 of the address range occupied by code for the current source line.
1308 * Go language support.
1309 GDB now supports debugging programs written in the Go programming
1312 * GDBserver now supports stdio connections.
1313 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1315 * The binary "gdbtui" can no longer be built or installed.
1316 Use "gdb -tui" instead.
1318 * GDB will now print "flag" enums specially. A flag enum is one where
1319 all the enumerator values have no bits in common when pairwise
1320 "and"ed. When printing a value whose type is a flag enum, GDB will
1321 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1322 (gdb) print (enum E) 3
1325 * The filename part of a linespec will now match trailing components
1326 of a source file name. For example, "break gcc/expr.c:1000" will
1327 now set a breakpoint in build/gcc/expr.c, but not
1328 build/libcpp/expr.c.
1330 * The "info proc" and "generate-core-file" commands will now also
1331 work on remote targets connected to GDBserver on Linux.
1333 * The command "info catch" has been removed. It has been disabled
1334 since December 2007.
1336 * The "catch exception" and "catch assert" commands now accept
1337 a condition at the end of the command, much like the "break"
1338 command does. For instance:
1340 (gdb) catch exception Constraint_Error if Barrier = True
1342 Previously, it was possible to add a condition to such catchpoints,
1343 but it had to be done as a second step, after the catchpoint had been
1344 created, using the "condition" command.
1346 * The "info static-tracepoint-marker" command will now also work on
1347 native Linux targets with in-process agent.
1349 * GDB can now set breakpoints on inlined functions.
1351 * The .gdb_index section has been updated to include symbols for
1352 inlined functions. GDB will ignore older .gdb_index sections by
1353 default, which could cause symbol files to be loaded more slowly
1354 until their .gdb_index sections can be recreated. The new command
1355 "set use-deprecated-index-sections on" will cause GDB to use any older
1356 .gdb_index sections it finds. This will restore performance, but the
1357 ability to set breakpoints on inlined functions will be lost in symbol
1358 files with older .gdb_index sections.
1360 The .gdb_index section has also been updated to record more information
1361 about each symbol. This speeds up the "info variables", "info functions"
1362 and "info types" commands when used with programs having the .gdb_index
1363 section, as well as speeding up debugging with shared libraries using
1364 the .gdb_index section.
1366 * Ada support for GDB/MI Variable Objects has been added.
1368 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1373 ** New command -info-os is the MI equivalent of "info os".
1375 ** Output logs ("set logging" and related) now include MI output.
1379 ** "set use-deprecated-index-sections on|off"
1380 "show use-deprecated-index-sections on|off"
1381 Controls the use of deprecated .gdb_index sections.
1383 ** "catch load" and "catch unload" can be used to stop when a shared
1384 library is loaded or unloaded, respectively.
1386 ** "enable count" can be used to auto-disable a breakpoint after
1389 ** "info vtbl" can be used to show the virtual method tables for
1390 C++ and Java objects.
1392 ** "explore" and its sub commands "explore value" and "explore type"
1393 can be used to recursively explore values and types of
1394 expressions. These commands are available only if GDB is
1395 configured with '--with-python'.
1397 ** "info auto-load" shows status of all kinds of auto-loaded files,
1398 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1399 sequences of commands files, "info auto-load python-scripts"
1400 shows status of auto-loading Python script files,
1401 "info auto-load local-gdbinit" shows status of loading init file
1402 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1403 status of inferior specific thread debugging shared library loading.
1405 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1406 and "show auto-load-scripts" commands have been deprecated, use their
1407 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1408 and "show auto-load python-scripts" counterparts instead.
1410 ** "dprintf location,format,args..." creates a dynamic printf, which
1411 is basically a breakpoint that does a printf and immediately
1412 resumes your program's execution, so it is like a printf that you
1413 can insert dynamically at runtime instead of at compiletime.
1415 ** "set print symbol"
1417 Controls whether GDB attempts to display the symbol, if any,
1418 corresponding to addresses it prints. This defaults to "on", but
1419 you can set it to "off" to restore GDB's previous behavior.
1421 * Deprecated commands
1423 ** For the Renesas Super-H architecture, the "regs" command has been
1424 deprecated, and "info all-registers" should be used instead.
1428 Renesas RL78 rl78-*-elf
1429 HP OpenVMS ia64 ia64-hp-openvms*
1431 * GDBserver supports evaluation of breakpoint conditions. When
1432 support is advertised by GDBserver, GDB may be told to send the
1433 breakpoint conditions in bytecode form to GDBserver. GDBserver
1434 will only report the breakpoint trigger to GDB when its condition
1439 set mips compression
1440 show mips compression
1441 Select the compressed ISA encoding used in functions that have no symbol
1442 information available. The encoding can be set to either of:
1445 and is updated automatically from ELF file flags if available.
1447 set breakpoint condition-evaluation
1448 show breakpoint condition-evaluation
1449 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1450 GDBserver ("target"). Default option "auto" chooses the most efficient
1452 This option can improve debugger efficiency depending on the speed of the
1456 Disable auto-loading globally.
1459 Show auto-loading setting of all kinds of auto-loaded files.
1461 set auto-load gdb-scripts on|off
1462 show auto-load gdb-scripts
1463 Control auto-loading of GDB canned sequences of commands files.
1465 set auto-load python-scripts on|off
1466 show auto-load python-scripts
1467 Control auto-loading of Python script files.
1469 set auto-load local-gdbinit on|off
1470 show auto-load local-gdbinit
1471 Control loading of init file (.gdbinit) from current directory.
1473 set auto-load libthread-db on|off
1474 show auto-load libthread-db
1475 Control auto-loading of inferior specific thread debugging shared library.
1477 set auto-load scripts-directory <dir1>[:<dir2>...]
1478 show auto-load scripts-directory
1479 Set a list of directories from which to load auto-loaded scripts.
1480 Automatically loaded Python scripts and GDB scripts are located in one
1481 of the directories listed by this option.
1482 The delimiter (':' above) may differ according to the host platform.
1484 set auto-load safe-path <dir1>[:<dir2>...]
1485 show auto-load safe-path
1486 Set a list of directories from which it is safe to auto-load files.
1487 The delimiter (':' above) may differ according to the host platform.
1489 set debug auto-load on|off
1490 show debug auto-load
1491 Control display of debugging info for auto-loading the files above.
1493 set dprintf-style gdb|call|agent
1495 Control the way in which a dynamic printf is performed; "gdb"
1496 requests a GDB printf command, while "call" causes dprintf to call a
1497 function in the inferior. "agent" requests that the target agent
1498 (such as GDBserver) do the printing.
1500 set dprintf-function <expr>
1501 show dprintf-function
1502 set dprintf-channel <expr>
1503 show dprintf-channel
1504 Set the function and optional first argument to the call when using
1505 the "call" style of dynamic printf.
1507 set disconnected-dprintf on|off
1508 show disconnected-dprintf
1509 Control whether agent-style dynamic printfs continue to be in effect
1510 after GDB disconnects.
1512 * New configure options
1514 --with-auto-load-dir
1515 Configure default value for the 'set auto-load scripts-directory'
1516 setting above. It defaults to '$debugdir:$datadir/auto-load',
1517 $debugdir representing global debugging info directories (available
1518 via 'show debug-file-directory') and $datadir representing GDB's data
1519 directory (available via 'show data-directory').
1521 --with-auto-load-safe-path
1522 Configure default value for the 'set auto-load safe-path' setting
1523 above. It defaults to the --with-auto-load-dir setting.
1525 --without-auto-load-safe-path
1526 Set 'set auto-load safe-path' to '/', effectively disabling this
1529 * New remote packets
1531 z0/z1 conditional breakpoints extension
1533 The z0/z1 breakpoint insertion packets have been extended to carry
1534 a list of conditional expressions over to the remote stub depending on the
1535 condition evaluation mode. The use of this extension can be controlled
1536 via the "set remote conditional-breakpoints-packet" command.
1540 Specify the signals which the remote stub may pass to the debugged
1541 program without GDB involvement.
1543 * New command line options
1545 --init-command=FILE, -ix Like --command, -x but execute it
1546 before loading inferior.
1547 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1548 execute it before loading inferior.
1550 *** Changes in GDB 7.4
1552 * GDB now handles ambiguous linespecs more consistently; the existing
1553 FILE:LINE support has been expanded to other types of linespecs. A
1554 breakpoint will now be set on all matching locations in all
1555 inferiors, and locations will be added or removed according to
1558 * GDB now allows you to skip uninteresting functions and files when
1559 stepping with the "skip function" and "skip file" commands.
1561 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1562 and "show remote hardware-watchpoint-length-limit". These allows to
1563 set or show the maximum length limit (in bytes) of a remote
1564 target hardware watchpoint.
1566 This allows e.g. to use "unlimited" hardware watchpoints with the
1567 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1568 watchpoints are slower than real hardware watchpoints but are
1569 significantly faster than gdb software watchpoints.
1573 ** The register_pretty_printer function in module gdb.printing now takes
1574 an optional `replace' argument. If True, the new printer replaces any
1577 ** The "maint set python print-stack on|off" command has been
1578 deprecated and will be deleted in GDB 7.5.
1579 A new command: "set python print-stack none|full|message" has
1580 replaced it. Additionally, the default for "print-stack" is
1581 now "message", which just prints the error message without
1584 ** A prompt substitution hook (prompt_hook) is now available to the
1587 ** A new Python module, gdb.prompt has been added to the GDB Python
1588 modules library. This module provides functionality for
1589 escape sequences in prompts (used by set/show
1590 extended-prompt). These escape sequences are replaced by their
1591 corresponding value.
1593 ** Python commands and convenience-functions located in
1594 'data-directory'/python/gdb/command and
1595 'data-directory'/python/gdb/function are now automatically loaded
1598 ** Blocks now provide four new attributes. global_block and
1599 static_block will return the global and static blocks
1600 respectively. is_static and is_global are boolean attributes
1601 that indicate if the block is one of those two types.
1603 ** Symbols now provide the "type" attribute, the type of the symbol.
1605 ** The "gdb.breakpoint" function has been deprecated in favor of
1608 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1609 of a function. This class is based on the "finish" command
1610 available in the CLI.
1612 ** Type objects for struct and union types now allow access to
1613 the fields using standard Python dictionary (mapping) methods.
1614 For example, "some_type['myfield']" now works, as does
1615 "some_type.items()".
1617 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1620 ** A new function, "deep_items" has been added to the gdb.types
1621 module in the GDB Python modules library. This function returns
1622 an iterator over the fields of a struct or union type. Unlike
1623 the standard Python "iteritems" method, it will recursively traverse
1624 any anonymous fields.
1628 ** "*stopped" events can report several new "reason"s, such as
1631 ** Breakpoint changes are now notified using new async records, like
1632 "=breakpoint-modified".
1634 ** New command -ada-task-info.
1636 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1637 $sdir specifies the default system locations of shared libraries.
1638 $pdir specifies the directory where the libpthread used by the application
1641 GDB no longer looks in $sdir and $pdir after it has searched the directories
1642 mentioned in libthread-db-search-path. If you want to search those
1643 directories, they must be specified in libthread-db-search-path.
1644 The default value of libthread-db-search-path on GNU/Linux and Solaris
1645 systems is now "$sdir:$pdir".
1647 $pdir is not supported by gdbserver, it is currently ignored.
1648 $sdir is supported by gdbserver.
1650 * New configure option --with-iconv-bin.
1651 When using the internationalization support like the one in the GNU C
1652 library, GDB will invoke the "iconv" program to get a list of supported
1653 character sets. If this program lives in a non-standard location, one can
1654 use this option to specify where to find it.
1656 * When natively debugging programs on PowerPC BookE processors running
1657 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1658 watchpoints, which specify a mask in addition to an address to watch.
1659 The mask specifies that some bits of an address (the bits which are
1660 reset in the mask) should be ignored when matching the address accessed
1661 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1662 section in the user manual for more details.
1664 * The new option --once causes GDBserver to stop listening for connections once
1665 the first connection is made. The listening port used by GDBserver will
1666 become available after that.
1668 * New commands "info macros" and "alias" have been added.
1670 * New function parameters suffix @entry specifies value of function parameter
1671 at the time the function got called. Entry values are available only since
1677 "!" is now an alias of the "shell" command.
1678 Note that no space is needed between "!" and SHELL COMMAND.
1682 watch EXPRESSION mask MASK_VALUE
1683 The watch command now supports the mask argument which allows creation
1684 of masked watchpoints, if the current architecture supports this feature.
1686 info auto-load-scripts [REGEXP]
1687 This command was formerly named "maintenance print section-scripts".
1688 It is now generally useful and is no longer a maintenance-only command.
1690 info macro [-all] [--] MACRO
1691 The info macro command has new options `-all' and `--'. The first for
1692 printing all definitions of a macro. The second for explicitly specifying
1693 the end of arguments and the beginning of the macro name in case the macro
1694 name starts with a hyphen.
1696 collect[/s] EXPRESSIONS
1697 The tracepoint collect command now takes an optional modifier "/s"
1698 that directs it to dereference pointer-to-character types and
1699 collect the bytes of memory up to a zero byte. The behavior is
1700 similar to what you see when you use the regular print command on a
1701 string. An optional integer following the "/s" sets a bound on the
1702 number of bytes that will be collected.
1705 The trace start command now interprets any supplied arguments as a
1706 note to be recorded with the trace run, with an effect similar to
1707 setting the variable trace-notes.
1710 The trace stop command now interprets any arguments as a note to be
1711 mentioned along with the tstatus report that the trace was stopped
1712 with a command. The effect is similar to setting the variable
1715 * Tracepoints can now be enabled and disabled at any time after a trace
1716 experiment has been started using the standard "enable" and "disable"
1717 commands. It is now possible to start a trace experiment with no enabled
1718 tracepoints; GDB will display a warning, but will allow the experiment to
1719 begin, assuming that tracepoints will be enabled as needed while the trace
1722 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1723 locations with 4-byte instructions, when they were previously
1724 limited to locations with instructions of 5 bytes or longer.
1728 set debug dwarf2-read
1729 show debug dwarf2-read
1730 Turns on or off display of debugging messages related to reading
1731 DWARF debug info. The default is off.
1733 set debug symtab-create
1734 show debug symtab-create
1735 Turns on or off display of debugging messages related to symbol table
1736 creation. The default is off.
1739 show extended-prompt
1740 Set the GDB prompt, and allow escape sequences to be inserted to
1741 display miscellaneous information (see 'help set extended-prompt'
1742 for the list of sequences). This prompt (and any information
1743 accessed through the escape sequences) is updated every time the
1744 prompt is displayed.
1746 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1747 show print entry-values
1748 Set printing of frame argument values at function entry. In some cases
1749 GDB can determine the value of function argument which was passed by the
1750 function caller, even if the value was modified inside the called function.
1752 set debug entry-values
1753 show debug entry-values
1754 Control display of debugging info for determining frame argument values at
1755 function entry and virtual tail call frames.
1757 set basenames-may-differ
1758 show basenames-may-differ
1759 Set whether a source file may have multiple base names.
1760 (A "base name" is the name of a file with the directory part removed.
1761 Example: The base name of "/home/user/hello.c" is "hello.c".)
1762 If set, GDB will canonicalize file names (e.g., expand symlinks)
1763 before comparing them. Canonicalization is an expensive operation,
1764 but it allows the same file be known by more than one base name.
1765 If not set (the default), all source files are assumed to have just
1766 one base name, and gdb will do file name comparisons more efficiently.
1772 Set a user name and notes for the current and any future trace runs.
1773 This is useful for long-running and/or disconnected traces, to
1774 inform others (or yourself) as to who is running the trace, supply
1775 contact information, or otherwise explain what is going on.
1777 set trace-stop-notes
1778 show trace-stop-notes
1779 Set a note attached to the trace run, that is displayed when the
1780 trace has been stopped by a tstop command. This is useful for
1781 instance as an explanation, if you are stopping a trace run that was
1782 started by someone else.
1784 * New remote packets
1788 Dynamically enable a tracepoint in a started trace experiment.
1792 Dynamically disable a tracepoint in a started trace experiment.
1796 Set the user and notes of the trace run.
1800 Query the current status of a tracepoint.
1804 Query the minimum length of instruction at which a fast tracepoint may
1807 * Dcache size (number of lines) and line-size are now runtime-configurable
1808 via "set dcache line" and "set dcache line-size" commands.
1812 Texas Instruments TMS320C6x tic6x-*-*
1816 Renesas RL78 rl78-*-elf
1818 *** Changes in GDB 7.3.1
1820 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1822 *** Changes in GDB 7.3
1824 * GDB has a new command: "thread find [REGEXP]".
1825 It finds the thread id whose name, target id, or thread extra info
1826 matches the given regular expression.
1828 * The "catch syscall" command now works on mips*-linux* targets.
1830 * The -data-disassemble MI command now supports modes 2 and 3 for
1831 dumping the instruction opcodes.
1833 * New command line options
1835 -data-directory DIR Specify DIR as the "data-directory".
1836 This is mostly for testing purposes.
1838 * The "maint set python auto-load on|off" command has been renamed to
1839 "set auto-load-scripts on|off".
1841 * GDB has a new command: "set directories".
1842 It is like the "dir" command except that it replaces the
1843 source path list instead of augmenting it.
1845 * GDB now understands thread names.
1847 On GNU/Linux, "info threads" will display the thread name as set by
1848 prctl or pthread_setname_np.
1850 There is also a new command, "thread name", which can be used to
1851 assign a name internally for GDB to display.
1854 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1855 has been integrated into GDB.
1859 ** The function gdb.Write now accepts an optional keyword 'stream'.
1860 This keyword, when provided, will direct the output to either
1861 stdout, stderr, or GDB's logging output.
1863 ** Parameters can now be be sub-classed in Python, and in particular
1864 you may implement the get_set_doc and get_show_doc functions.
1865 This improves how Parameter set/show documentation is processed
1866 and allows for more dynamic content.
1868 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1869 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1870 have an is_valid method.
1872 ** Breakpoints can now be sub-classed in Python, and in particular
1873 you may implement a 'stop' function that is executed each time
1874 the inferior reaches that breakpoint.
1876 ** New function gdb.lookup_global_symbol looks up a global symbol.
1878 ** GDB values in Python are now callable if the value represents a
1879 function. For example, if 'some_value' represents a function that
1880 takes two integer parameters and returns a value, you can call
1881 that function like so:
1883 result = some_value (10,20)
1885 ** Module gdb.types has been added.
1886 It contains a collection of utilities for working with gdb.Types objects:
1887 get_basic_type, has_field, make_enum_dict.
1889 ** Module gdb.printing has been added.
1890 It contains utilities for writing and registering pretty-printers.
1891 New classes: PrettyPrinter, SubPrettyPrinter,
1892 RegexpCollectionPrettyPrinter.
1893 New function: register_pretty_printer.
1895 ** New commands "info pretty-printers", "enable pretty-printer" and
1896 "disable pretty-printer" have been added.
1898 ** gdb.parameter("directories") is now available.
1900 ** New function gdb.newest_frame returns the newest frame in the
1903 ** The gdb.InferiorThread class has a new "name" attribute. This
1904 holds the thread's name.
1906 ** Python Support for Inferior events.
1907 Python scripts can add observers to be notified of events
1908 occurring in the process being debugged.
1909 The following events are currently supported:
1910 - gdb.events.cont Continue event.
1911 - gdb.events.exited Inferior exited event.
1912 - gdb.events.stop Signal received, and Breakpoint hit events.
1916 ** GDB now puts template parameters in scope when debugging in an
1917 instantiation. For example, if you have:
1919 template<int X> int func (void) { return X; }
1921 then if you step into func<5>, "print X" will show "5". This
1922 feature requires proper debuginfo support from the compiler; it
1923 was added to GCC 4.5.
1925 ** The motion commands "next", "finish", "until", and "advance" now
1926 work better when exceptions are thrown. In particular, GDB will
1927 no longer lose control of the inferior; instead, the GDB will
1928 stop the inferior at the point at which the exception is caught.
1929 This functionality requires a change in the exception handling
1930 code that was introduced in GCC 4.5.
1932 * GDB now follows GCC's rules on accessing volatile objects when
1933 reading or writing target state during expression evaluation.
1934 One notable difference to prior behavior is that "print x = 0"
1935 no longer generates a read of x; the value of the assignment is
1936 now always taken directly from the value being assigned.
1938 * GDB now has some support for using labels in the program's source in
1939 linespecs. For instance, you can use "advance label" to continue
1940 execution to a label.
1942 * GDB now has support for reading and writing a new .gdb_index
1943 section. This section holds a fast index of DWARF debugging
1944 information and can be used to greatly speed up GDB startup and
1945 operation. See the documentation for `save gdb-index' for details.
1947 * The "watch" command now accepts an optional "-location" argument.
1948 When used, this causes GDB to watch the memory referred to by the
1949 expression. Such a watchpoint is never deleted due to it going out
1952 * GDB now supports thread debugging of core dumps on GNU/Linux.
1954 GDB now activates thread debugging using the libthread_db library
1955 when debugging GNU/Linux core dumps, similarly to when debugging
1956 live processes. As a result, when debugging a core dump file, GDB
1957 is now able to display pthread_t ids of threads. For example, "info
1958 threads" shows the same output as when debugging the process when it
1959 was live. In earlier releases, you'd see something like this:
1962 * 1 LWP 6780 main () at main.c:10
1964 While now you see this:
1967 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1969 It is also now possible to inspect TLS variables when debugging core
1972 When debugging a core dump generated on a machine other than the one
1973 used to run GDB, you may need to point GDB at the correct
1974 libthread_db library with the "set libthread-db-search-path"
1975 command. See the user manual for more details on this command.
1977 * When natively debugging programs on PowerPC BookE processors running
1978 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1979 which stop execution of the inferior whenever it executes an instruction
1980 at any address within the specified range. See the "PowerPC Embedded"
1981 section in the user manual for more details.
1983 * New features in the GDB remote stub, GDBserver
1985 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1986 and i686 LynxOS (version 5.x).
1988 ** GDBserver is now supported on Blackfin Linux.
1990 * New native configurations
1992 ia64 HP-UX ia64-*-hpux*
1996 Analog Devices, Inc. Blackfin Processor bfin-*
1998 * Ada task switching is now supported on sparc-elf targets when
1999 debugging a program using the Ravenscar Profile. For more information,
2000 see the "Tasking Support when using the Ravenscar Profile" section
2001 in the GDB user manual.
2003 * Guile support was removed.
2005 * New features in the GNU simulator
2007 ** The --map-info flag lists all known core mappings.
2009 ** CFI flashes may be simulated via the "cfi" device.
2011 *** Changes in GDB 7.2
2013 * Shared library support for remote targets by default
2015 When GDB is configured for a generic, non-OS specific target, like
2016 for example, --target=arm-eabi or one of the many *-*-elf targets,
2017 GDB now queries remote stubs for loaded shared libraries using the
2018 `qXfer:libraries:read' packet. Previously, shared library support
2019 was always disabled for such configurations.
2023 ** Argument Dependent Lookup (ADL)
2025 In C++ ADL lookup directs function search to the namespaces of its
2026 arguments even if the namespace has not been imported.
2036 Here the compiler will search for `foo' in the namespace of 'b'
2037 and find A::foo. GDB now supports this. This construct is commonly
2038 used in the Standard Template Library for operators.
2040 ** Improved User Defined Operator Support
2042 In addition to member operators, GDB now supports lookup of operators
2043 defined in a namespace and imported with a `using' directive, operators
2044 defined in the global scope, operators imported implicitly from an
2045 anonymous namespace, and the ADL operators mentioned in the previous
2047 GDB now also supports proper overload resolution for all the previously
2048 mentioned flavors of operators.
2050 ** static const class members
2052 Printing of static const class members that are initialized in the
2053 class definition has been fixed.
2055 * Windows Thread Information Block access.
2057 On Windows targets, GDB now supports displaying the Windows Thread
2058 Information Block (TIB) structure. This structure is visible either
2059 by using the new command `info w32 thread-information-block' or, by
2060 dereferencing the new convenience variable named `$_tlb', a
2061 thread-specific pointer to the TIB. This feature is also supported
2062 when remote debugging using GDBserver.
2064 * Static tracepoints
2066 Static tracepoints are calls in the user program into a tracing
2067 library. One such library is a port of the LTTng kernel tracer to
2068 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2069 When debugging with GDBserver, GDB now supports combining the GDB
2070 tracepoint machinery with such libraries. For example: the user can
2071 use GDB to probe a static tracepoint marker (a call from the user
2072 program into the tracing library) with the new "strace" command (see
2073 "New commands" below). This creates a "static tracepoint" in the
2074 breakpoint list, that can be manipulated with the same feature set
2075 as fast and regular tracepoints. E.g., collect registers, local and
2076 global variables, collect trace state variables, and define
2077 tracepoint conditions. In addition, the user can collect extra
2078 static tracepoint marker specific data, by collecting the new
2079 $_sdata internal variable. When analyzing the trace buffer, you can
2080 inspect $_sdata like any other variable available to GDB. For more
2081 information, see the "Tracepoints" chapter in GDB user manual. New
2082 remote packets have been defined to support static tracepoints, see
2083 the "New remote packets" section below.
2085 * Better reconstruction of tracepoints after disconnected tracing
2087 GDB will attempt to download the original source form of tracepoint
2088 definitions when starting a trace run, and then will upload these
2089 upon reconnection to the target, resulting in a more accurate
2090 reconstruction of the tracepoints that are in use on the target.
2094 You can now exercise direct control over the ways that GDB can
2095 affect your program. For instance, you can disallow the setting of
2096 breakpoints, so that the program can run continuously (assuming
2097 non-stop mode). In addition, the "observer" variable is available
2098 to switch all of the different controls; in observer mode, GDB
2099 cannot affect the target's behavior at all, which is useful for
2100 tasks like diagnosing live systems in the field.
2102 * The new convenience variable $_thread holds the number of the
2105 * New remote packets
2109 Return the address of the Windows Thread Information Block of a given thread.
2113 In response to several of the tracepoint packets, the target may now
2114 also respond with a number of intermediate `qRelocInsn' request
2115 packets before the final result packet, to have GDB handle
2116 relocating an instruction to execute at a different address. This
2117 is particularly useful for stubs that support fast tracepoints. GDB
2118 reports support for this feature in the qSupported packet.
2122 List static tracepoint markers in the target program.
2126 List static tracepoint markers at a given address in the target
2129 qXfer:statictrace:read
2131 Read the static trace data collected (by a `collect $_sdata'
2132 tracepoint action). The remote stub reports support for this packet
2133 to gdb's qSupported query.
2137 Send the current settings of GDB's permission flags.
2141 Send part of the source (textual) form of a tracepoint definition,
2142 which includes location, conditional, and action list.
2144 * The source command now accepts a -s option to force searching for the
2145 script in the source search path even if the script name specifies
2148 * New features in the GDB remote stub, GDBserver
2150 - GDBserver now support tracepoints (including fast tracepoints, and
2151 static tracepoints). The feature is currently supported by the
2152 i386-linux and amd64-linux builds. See the "Tracepoints support
2153 in gdbserver" section in the manual for more information.
2155 GDBserver JIT compiles the tracepoint's conditional agent
2156 expression bytecode into native code whenever possible for low
2157 overhead dynamic tracepoints conditionals. For such tracepoints,
2158 an expression that examines program state is evaluated when the
2159 tracepoint is reached, in order to determine whether to capture
2160 trace data. If the condition is simple and false, processing the
2161 tracepoint finishes very quickly and no data is gathered.
2163 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2164 for static tracepoints support.
2166 - GDBserver now supports x86_64 Windows 64-bit debugging.
2168 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2169 it understands register description.
2171 * The --batch flag now disables pagination and queries.
2173 * X86 general purpose registers
2175 GDB now supports reading/writing byte, word and double-word x86
2176 general purpose registers directly. This means you can use, say,
2177 $ah or $ax to refer, respectively, to the byte register AH and
2178 16-bit word register AX that are actually portions of the 32-bit
2179 register EAX or 64-bit register RAX.
2181 * The `commands' command now accepts a range of breakpoints to modify.
2182 A plain `commands' following a command that creates multiple
2183 breakpoints affects all the breakpoints set by that command. This
2184 applies to breakpoints set by `rbreak', and also applies when a
2185 single `break' command creates multiple breakpoints (e.g.,
2186 breakpoints on overloaded c++ functions).
2188 * The `rbreak' command now accepts a filename specification as part of
2189 its argument, limiting the functions selected by the regex to those
2190 in the specified file.
2192 * Support for remote debugging Windows and SymbianOS shared libraries
2193 from Unix hosts has been improved. Non Windows GDB builds now can
2194 understand target reported file names that follow MS-DOS based file
2195 system semantics, such as file names that include drive letters and
2196 use the backslash character as directory separator. This makes it
2197 possible to transparently use the "set sysroot" and "set
2198 solib-search-path" on Unix hosts to point as host copies of the
2199 target's shared libraries. See the new command "set
2200 target-file-system-kind" described below, and the "Commands to
2201 specify files" section in the user manual for more information.
2205 eval template, expressions...
2206 Convert the values of one or more expressions under the control
2207 of the string template to a command line, and call it.
2209 set target-file-system-kind unix|dos-based|auto
2210 show target-file-system-kind
2211 Set or show the assumed file system kind for target reported file
2214 save breakpoints <filename>
2215 Save all current breakpoint definitions to a file suitable for use
2216 in a later debugging session. To read the saved breakpoint
2217 definitions, use the `source' command.
2219 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2222 info static-tracepoint-markers
2223 Display information about static tracepoint markers in the target.
2225 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2226 Define a static tracepoint by probing a marker at the given
2227 function, line, address, or marker ID.
2231 Enable and disable observer mode.
2233 set may-write-registers on|off
2234 set may-write-memory on|off
2235 set may-insert-breakpoints on|off
2236 set may-insert-tracepoints on|off
2237 set may-insert-fast-tracepoints on|off
2238 set may-interrupt on|off
2239 Set individual permissions for GDB effects on the target. Note that
2240 some of these settings can have undesirable or surprising
2241 consequences, particularly when changed in the middle of a session.
2242 For instance, disabling the writing of memory can prevent
2243 breakpoints from being inserted, cause single-stepping to fail, or
2244 even crash your program, if you disable after breakpoints have been
2245 inserted. However, GDB should not crash.
2247 set record memory-query on|off
2248 show record memory-query
2249 Control whether to stop the inferior if memory changes caused
2250 by an instruction cannot be recorded.
2255 The disassemble command now supports "start,+length" form of two arguments.
2259 ** GDB now provides a new directory location, called the python directory,
2260 where Python scripts written for GDB can be installed. The location
2261 of that directory is <data-directory>/python, where <data-directory>
2262 is the GDB data directory. For more details, see section `Scripting
2263 GDB using Python' in the manual.
2265 ** The GDB Python API now has access to breakpoints, symbols, symbol
2266 tables, program spaces, inferiors, threads and frame's code blocks.
2267 Additionally, GDB Parameters can now be created from the API, and
2268 manipulated via set/show in the CLI.
2270 ** New functions gdb.target_charset, gdb.target_wide_charset,
2271 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2273 ** New exception gdb.GdbError.
2275 ** Pretty-printers are now also looked up in the current program space.
2277 ** Pretty-printers can now be individually enabled and disabled.
2279 ** GDB now looks for names of Python scripts to auto-load in a
2280 special section named `.debug_gdb_scripts', in addition to looking
2281 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2283 * Tracepoint actions were unified with breakpoint commands. In particular,
2284 there are no longer differences in "info break" output for breakpoints and
2285 tracepoints and the "commands" command can be used for both tracepoints and
2286 regular breakpoints.
2290 ARM Symbian arm*-*-symbianelf*
2292 * D language support.
2293 GDB now supports debugging programs written in the D programming
2296 * GDB now supports the extended ptrace interface for PowerPC which is
2297 available since Linux kernel version 2.6.34. This automatically enables
2298 any hardware breakpoints and additional hardware watchpoints available in
2299 the processor. The old ptrace interface exposes just one hardware
2300 watchpoint and no hardware breakpoints.
2302 * GDB is now able to use the Data Value Compare (DVC) register available on
2303 embedded PowerPC processors to implement in hardware simple watchpoint
2304 conditions of the form:
2306 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2308 This works in native GDB running on Linux kernels with the extended ptrace
2309 interface mentioned above.
2311 *** Changes in GDB 7.1
2315 ** Namespace Support
2317 GDB now supports importing of namespaces in C++. This enables the
2318 user to inspect variables from imported namespaces. Support for
2319 namepace aliasing has also been added. So, if a namespace is
2320 aliased in the current scope (e.g. namepace C=A; ) the user can
2321 print variables using the alias (e.g. (gdb) print C::x).
2325 All known bugs relating to the printing of virtual base class were
2326 fixed. It is now possible to call overloaded static methods using a
2331 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2332 and reinterpret_cast<> are now handled by the C++ expression parser.
2336 Xilinx MicroBlaze microblaze-*-*
2341 Xilinx MicroBlaze microblaze
2344 * Multi-program debugging.
2346 GDB now has support for multi-program (a.k.a. multi-executable or
2347 multi-exec) debugging. This allows for debugging multiple inferiors
2348 simultaneously each running a different program under the same GDB
2349 session. See "Debugging Multiple Inferiors and Programs" in the
2350 manual for more information. This implied some user visible changes
2351 in the multi-inferior support. For example, "info inferiors" now
2352 lists inferiors that are not running yet or that have exited
2353 already. See also "New commands" and "New options" below.
2355 * New tracing features
2357 GDB's tracepoint facility now includes several new features:
2359 ** Trace state variables
2361 GDB tracepoints now include support for trace state variables, which
2362 are variables managed by the target agent during a tracing
2363 experiment. They are useful for tracepoints that trigger each
2364 other, so for instance one tracepoint can count hits in a variable,
2365 and then a second tracepoint has a condition that is true when the
2366 count reaches a particular value. Trace state variables share the
2367 $-syntax of GDB convenience variables, and can appear in both
2368 tracepoint actions and condition expressions. Use the "tvariable"
2369 command to create, and "info tvariables" to view; see "Trace State
2370 Variables" in the manual for more detail.
2374 GDB now includes an option for defining fast tracepoints, which
2375 targets may implement more efficiently, such as by installing a jump
2376 into the target agent rather than a trap instruction. The resulting
2377 speedup can be by two orders of magnitude or more, although the
2378 tradeoff is that some program locations on some target architectures
2379 might not allow fast tracepoint installation, for instance if the
2380 instruction to be replaced is shorter than the jump. To request a
2381 fast tracepoint, use the "ftrace" command, with syntax identical to
2382 the regular trace command.
2384 ** Disconnected tracing
2386 It is now possible to detach GDB from the target while it is running
2387 a trace experiment, then reconnect later to see how the experiment
2388 is going. In addition, a new variable disconnected-tracing lets you
2389 tell the target agent whether to continue running a trace if the
2390 connection is lost unexpectedly.
2394 GDB now has the ability to save the trace buffer into a file, and
2395 then use that file as a target, similarly to you can do with
2396 corefiles. You can select trace frames, print data that was
2397 collected in them, and use tstatus to display the state of the
2398 tracing run at the moment that it was saved. To create a trace
2399 file, use "tsave <filename>", and to use it, do "target tfile
2402 ** Circular trace buffer
2404 You can ask the target agent to handle the trace buffer as a
2405 circular buffer, discarding the oldest trace frames to make room for
2406 newer ones, by setting circular-trace-buffer to on. This feature may
2407 not be available for all target agents.
2412 The disassemble command, when invoked with two arguments, now requires
2413 the arguments to be comma-separated.
2416 The info variables command now displays variable definitions. Files
2417 which only declare a variable are not shown.
2420 The source command is now capable of sourcing Python scripts.
2421 This feature is dependent on the debugger being build with Python
2424 Related to this enhancement is also the introduction of a new command
2425 "set script-extension" (see below).
2427 * New commands (for set/show, see "New options" below)
2429 record save [<FILENAME>]
2430 Save a file (in core file format) containing the process record
2431 execution log for replay debugging at a later time.
2433 record restore <FILENAME>
2434 Restore the process record execution log that was saved at an
2435 earlier time, for replay debugging.
2437 add-inferior [-copies <N>] [-exec <FILENAME>]
2440 clone-inferior [-copies <N>] [ID]
2441 Make a new inferior ready to execute the same program another
2442 inferior has loaded.
2447 maint info program-spaces
2448 List the program spaces loaded into GDB.
2450 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2451 show remote interrupt-sequence
2452 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2453 as the sequence to the remote target in order to interrupt the execution.
2454 Ctrl-C is a default. Some system prefers BREAK which is high level of
2455 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2456 Magic SysRq g. It is BREAK signal and character 'g'.
2458 set remote interrupt-on-connect [on | off]
2459 show remote interrupt-on-connect
2460 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2461 remote target when gdb connects to it. This is needed when you debug
2464 set remotebreak [on | off]
2466 Deprecated. Use "set/show remote interrupt-sequence" instead.
2468 tvariable $NAME [ = EXP ]
2469 Create or modify a trace state variable.
2472 List trace state variables and their values.
2474 delete tvariable $NAME ...
2475 Delete one or more trace state variables.
2478 Evaluate the given expressions without collecting anything into the
2479 trace buffer. (Valid in tracepoint actions only.)
2481 ftrace FN / FILE:LINE / *ADDR
2482 Define a fast tracepoint at the given function, line, or address.
2484 * New expression syntax
2486 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2487 GDB now parses 0b101010 identically with 42.
2491 set follow-exec-mode new|same
2492 show follow-exec-mode
2493 Control whether GDB reuses the same inferior across an exec call or
2494 creates a new one. This is useful to be able to restart the old
2495 executable after the inferior having done an exec call.
2497 set default-collect EXPR, ...
2498 show default-collect
2499 Define a list of expressions to be collected at each tracepoint.
2500 This is a useful way to ensure essential items are not overlooked,
2501 such as registers or a critical global variable.
2503 set disconnected-tracing
2504 show disconnected-tracing
2505 If set to 1, the target is instructed to continue tracing if it
2506 loses its connection to GDB. If 0, the target is to stop tracing
2509 set circular-trace-buffer
2510 show circular-trace-buffer
2511 If set to on, the target is instructed to use a circular trace buffer
2512 and discard the oldest trace frames instead of stopping the trace due
2513 to a full trace buffer. If set to off, the trace stops when the buffer
2514 fills up. Some targets may not support this.
2516 set script-extension off|soft|strict
2517 show script-extension
2518 If set to "off", the debugger does not perform any script language
2519 recognition, and all sourced files are assumed to be GDB scripts.
2520 If set to "soft" (the default), files are sourced according to
2521 filename extension, falling back to GDB scripts if the first
2523 If set to "strict", files are sourced according to filename extension.
2525 set ada trust-PAD-over-XVS on|off
2526 show ada trust-PAD-over-XVS
2527 If off, activate a workaround against a bug in the debugging information
2528 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2529 the GCC sources for more information about the GNAT encoding and
2530 PAD types in particular). It is always safe to set this option to
2531 off, but this introduces a slight performance penalty. The default
2534 * Python API Improvements
2536 ** GDB provides the new class gdb.LazyString. This is useful in
2537 some pretty-printing cases. The new method gdb.Value.lazy_string
2538 provides a simple way to create objects of this type.
2540 ** The fields returned by gdb.Type.fields now have an
2541 `is_base_class' attribute.
2543 ** The new method gdb.Type.range returns the range of an array type.
2545 ** The new method gdb.parse_and_eval can be used to parse and
2546 evaluate an expression.
2548 * New remote packets
2551 Define a trace state variable.
2554 Get the current value of a trace state variable.
2557 Set desired tracing behavior upon disconnection.
2560 Set the trace buffer to be linear or circular.
2563 Get data about the tracepoints currently in use.
2567 Process record now works correctly with hardware watchpoints.
2569 Multiple bug fixes have been made to the mips-irix port, making it
2570 much more reliable. In particular:
2571 - Debugging threaded applications is now possible again. Previously,
2572 GDB would hang while starting the program, or while waiting for
2573 the program to stop at a breakpoint.
2574 - Attaching to a running process no longer hangs.
2575 - An error occurring while loading a core file has been fixed.
2576 - Changing the value of the PC register now works again. This fixes
2577 problems observed when using the "jump" command, or when calling
2578 a function from GDB, or even when assigning a new value to $pc.
2579 - With the "finish" and "return" commands, the return value for functions
2580 returning a small array is now correctly printed.
2581 - It is now possible to break on shared library code which gets executed
2582 during a shared library init phase (code executed while executing
2583 their .init section). Previously, the breakpoint would have no effect.
2584 - GDB is now able to backtrace through the signal handler for
2585 non-threaded programs.
2587 PIE (Position Independent Executable) programs debugging is now supported.
2588 This includes debugging execution of PIC (Position Independent Code) shared
2589 libraries although for that, it should be possible to run such libraries as an
2592 *** Changes in GDB 7.0
2594 * GDB now has an interface for JIT compilation. Applications that
2595 dynamically generate code can create symbol files in memory and register
2596 them with GDB. For users, the feature should work transparently, and
2597 for JIT developers, the interface is documented in the GDB manual in the
2598 "JIT Compilation Interface" chapter.
2600 * Tracepoints may now be conditional. The syntax is as for
2601 breakpoints; either an "if" clause appended to the "trace" command,
2602 or the "condition" command is available. GDB sends the condition to
2603 the target for evaluation using the same bytecode format as is used
2604 for tracepoint actions.
2606 * The disassemble command now supports: an optional /r modifier, print the
2607 raw instructions in hex as well as in symbolic form, and an optional /m
2608 modifier to print mixed source+assembly.
2610 * Process record and replay
2612 In a architecture environment that supports ``process record and
2613 replay'', ``process record and replay'' target can record a log of
2614 the process execution, and replay it with both forward and reverse
2617 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2618 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2619 set execution-direction {forward|reverse}, for targets that support
2622 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2623 feature is available with a native GDB running on kernel version
2626 * GDB now has support for multi-byte and wide character sets on the
2627 target. Strings whose character type is wchar_t, char16_t, or
2628 char32_t are now correctly printed. GDB supports wide- and unicode-
2629 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2630 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2631 `printf'. This feature requires iconv to work properly; if your
2632 system does not have a working iconv, GDB can use GNU libiconv. See
2633 the installation instructions for more information.
2635 * GDB now supports automatic retrieval of shared library files from
2636 remote targets. To use this feature, specify a system root that begins
2637 with the `remote:' prefix, either via the `set sysroot' command or via
2638 the `--with-sysroot' configure-time option.
2640 * "info sharedlibrary" now takes an optional regex of libraries to show,
2641 and it now reports if a shared library has no debugging information.
2643 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2644 now complete on file names.
2646 * When completing in expressions, gdb will attempt to limit
2647 completions to allowable structure or union fields, where appropriate.
2648 For instance, consider:
2650 # struct example { int f1; double f2; };
2651 # struct example variable;
2654 If the user types TAB at the end of this command line, the available
2655 completions will be "f1" and "f2".
2657 * Inlined functions are now supported. They show up in backtraces, and
2658 the "step", "next", and "finish" commands handle them automatically.
2660 * GDB now supports the token-splicing (##) and stringification (#)
2661 operators when expanding macros. It also supports variable-arity
2664 * GDB now supports inspecting extra signal information, exported by
2665 the new $_siginfo convenience variable. The feature is currently
2666 implemented on linux ARM, i386 and amd64.
2668 * GDB can now display the VFP floating point registers and NEON vector
2669 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2670 can provide these registers (requires Linux 2.6.30 or later). Remote
2671 and simulator targets may also provide them.
2673 * New remote packets
2676 Search memory for a sequence of bytes.
2679 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2680 operation over reliable transport links. Use of this packet is
2681 controlled by the `set remote noack-packet' command.
2684 Kill the process with the specified process ID. Use this in preference
2685 to `k' when multiprocess protocol extensions are supported.
2688 Obtains additional operating system information
2692 Read or write additional signal information.
2694 * Removed remote protocol undocumented extension
2696 An undocumented extension to the remote protocol's `S' stop reply
2697 packet that permited the stub to pass a process id was removed.
2698 Remote servers should use the `T' stop reply packet instead.
2700 * GDB now supports multiple function calling conventions according to the
2701 DWARF-2 DW_AT_calling_convention function attribute.
2703 * The SH target utilizes the aforementioned change to distinguish between gcc
2704 and Renesas calling convention. It also adds the new CLI commands
2705 `set/show sh calling-convention'.
2707 * GDB can now read compressed debug sections, as produced by GNU gold
2708 with the --compress-debug-sections=zlib flag.
2710 * 64-bit core files are now supported on AIX.
2712 * Thread switching is now supported on Tru64.
2714 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2715 which will be allocated using malloc later in program execution.
2717 * The qXfer:libraries:read remote procotol packet now allows passing a
2718 list of section offsets.
2720 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2721 conditions handling signals delivered during attach or thread creation
2722 have also been fixed.
2724 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2725 From the user's standpoint, all unqualified instances of True and False
2726 are treated as the standard definitions, regardless of context.
2728 * GDB now parses C++ symbol and type names more flexibly. For
2731 template<typename T> class C { };
2734 GDB will now correctly handle all of:
2736 ptype C<char const *>
2737 ptype C<char const*>
2738 ptype C<const char *>
2739 ptype C<const char*>
2741 * New features in the GDB remote stub, gdbserver
2743 - The "--wrapper" command-line argument tells gdbserver to use a
2744 wrapper program to launch programs for debugging.
2746 - On PowerPC and S/390 targets, it is now possible to use a single
2747 gdbserver executable to debug both 32-bit and 64-bit programs.
2748 (This requires gdbserver itself to be built as a 64-bit executable.)
2750 - gdbserver uses the new noack protocol mode for TCP connections to
2751 reduce communications latency, if also supported and enabled in GDB.
2753 - Support for the sparc64-linux-gnu target is now included in
2756 - The amd64-linux build of gdbserver now supports debugging both
2757 32-bit and 64-bit programs.
2759 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2760 now support hardware watchpoints, and will use them automatically
2765 GDB now has support for scripting using Python. Whether this is
2766 available is determined at configure time.
2768 New GDB commands can now be written in Python.
2770 * Ada tasking support
2772 Ada tasks can now be inspected in GDB. The following commands have
2776 Print the list of Ada tasks.
2778 Print detailed information about task number N.
2780 Print the task number of the current task.
2782 Switch the context of debugging to task number N.
2784 * Support for user-defined prefixed commands. The "define" command can
2785 add new commands to existing prefixes, e.g. "target".
2787 * Multi-inferior, multi-process debugging.
2789 GDB now has generalized support for multi-inferior debugging. See
2790 "Debugging Multiple Inferiors" in the manual for more information.
2791 Although availability still depends on target support, the command
2792 set is more uniform now. The GNU/Linux specific multi-forks support
2793 has been migrated to this new framework. This implied some user
2794 visible changes; see "New commands" and also "Removed commands"
2797 * Target descriptions can now describe the target OS ABI. See the
2798 "Target Description Format" section in the user manual for more
2801 * Target descriptions can now describe "compatible" architectures
2802 to indicate that the target can execute applications for a different
2803 architecture in addition to those for the main target architecture.
2804 See the "Target Description Format" section in the user manual for
2807 * Multi-architecture debugging.
2809 GDB now includes general supports for debugging applications on
2810 hybrid systems that use more than one single processor architecture
2811 at the same time. Each such hybrid architecture still requires
2812 specific support to be added. The only hybrid architecture supported
2813 in this version of GDB is the Cell Broadband Engine.
2815 * GDB now supports integrated debugging of Cell/B.E. applications that
2816 use both the PPU and SPU architectures. To enable support for hybrid
2817 Cell/B.E. debugging, you need to configure GDB to support both the
2818 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2819 --enable-targets configure option.
2821 * Non-stop mode debugging.
2823 For some targets, GDB now supports an optional mode of operation in
2824 which you can examine stopped threads while other threads continue
2825 to execute freely. This is referred to as non-stop mode, with the
2826 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2827 section in the user manual for more information.
2829 To be able to support remote non-stop debugging, a remote stub needs
2830 to implement the non-stop mode remote protocol extensions, as
2831 described in the "Remote Non-Stop" section of the user manual. The
2832 GDB remote stub, gdbserver, has been adjusted to support these
2833 extensions on linux targets.
2835 * New commands (for set/show, see "New options" below)
2837 catch syscall [NAME(S) | NUMBER(S)]
2838 Catch system calls. Arguments, which should be names of system
2839 calls or their numbers, mean catch only those syscalls. Without
2840 arguments, every syscall will be caught. When the inferior issues
2841 any of the specified syscalls, GDB will stop and announce the system
2842 call, both when it is called and when its call returns. This
2843 feature is currently available with a native GDB running on the
2844 Linux Kernel, under the following architectures: x86, x86_64,
2845 PowerPC and PowerPC64.
2847 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2849 Search memory for a sequence of bytes.
2851 maint set python print-stack
2852 maint show python print-stack
2853 Show a stack trace when an error is encountered in a Python script.
2856 Invoke CODE by passing it to the Python interpreter.
2861 These allow macros to be defined, undefined, and listed
2865 Show operating system information about processes.
2868 List the inferiors currently under GDB's control.
2871 Switch focus to inferior number NUM.
2874 Detach from inferior number NUM.
2877 Kill inferior number NUM.
2881 set spu stop-on-load
2882 show spu stop-on-load
2883 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2885 set spu auto-flush-cache
2886 show spu auto-flush-cache
2887 Control whether to automatically flush the software-managed cache
2888 during Cell/B.E. debugging.
2890 set sh calling-convention
2891 show sh calling-convention
2892 Control the calling convention used when calling SH target functions.
2895 show debug timestamp
2896 Control display of timestamps with GDB debugging output.
2898 set disassemble-next-line
2899 show disassemble-next-line
2900 Control display of disassembled source lines or instructions when
2903 set remote noack-packet
2904 show remote noack-packet
2905 Set/show the use of remote protocol QStartNoAckMode packet. See above
2906 under "New remote packets."
2908 set remote query-attached-packet
2909 show remote query-attached-packet
2910 Control use of remote protocol `qAttached' (query-attached) packet.
2912 set remote read-siginfo-object
2913 show remote read-siginfo-object
2914 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2917 set remote write-siginfo-object
2918 show remote write-siginfo-object
2919 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2922 set remote reverse-continue
2923 show remote reverse-continue
2924 Control use of remote protocol 'bc' (reverse-continue) packet.
2926 set remote reverse-step
2927 show remote reverse-step
2928 Control use of remote protocol 'bs' (reverse-step) packet.
2930 set displaced-stepping
2931 show displaced-stepping
2932 Control displaced stepping mode. Displaced stepping is a way to
2933 single-step over breakpoints without removing them from the debuggee.
2934 Also known as "out-of-line single-stepping".
2937 show debug displaced
2938 Control display of debugging info for displaced stepping.
2940 maint set internal-error
2941 maint show internal-error
2942 Control what GDB does when an internal error is detected.
2944 maint set internal-warning
2945 maint show internal-warning
2946 Control what GDB does when an internal warning is detected.
2951 Use a wrapper program to launch programs for debugging.
2953 set multiple-symbols (all|ask|cancel)
2954 show multiple-symbols
2955 The value of this variable can be changed to adjust the debugger behavior
2956 when an expression or a breakpoint location contains an ambiguous symbol
2957 name (an overloaded function name, for instance).
2959 set breakpoint always-inserted
2960 show breakpoint always-inserted
2961 Keep breakpoints always inserted in the target, as opposed to inserting
2962 them when resuming the target, and removing them when the target stops.
2963 This option can improve debugger performance on slow remote targets.
2965 set arm fallback-mode (arm|thumb|auto)
2966 show arm fallback-mode
2967 set arm force-mode (arm|thumb|auto)
2969 These commands control how ARM GDB determines whether instructions
2970 are ARM or Thumb. The default for both settings is auto, which uses
2971 the current CPSR value for instructions without symbols; previous
2972 versions of GDB behaved as if "set arm fallback-mode arm".
2974 set disable-randomization
2975 show disable-randomization
2976 Standalone programs run with the virtual address space randomization enabled
2977 by default on some platforms. This option keeps the addresses stable across
2978 multiple debugging sessions.
2982 Control whether other threads are stopped or not when some thread hits
2987 Requests that asynchronous execution is enabled in the target, if available.
2988 In this case, it's possible to resume target in the background, and interact
2989 with GDB while the target is running. "show target-async" displays the
2990 current state of asynchronous execution of the target.
2992 set target-wide-charset
2993 show target-wide-charset
2994 The target-wide-charset is the name of the character set that GDB
2995 uses when printing characters whose type is wchar_t.
2997 set tcp auto-retry (on|off)
2999 set tcp connect-timeout
3000 show tcp connect-timeout
3001 These commands allow GDB to retry failed TCP connections to a remote stub
3002 with a specified timeout period; this is useful if the stub is launched
3003 in parallel with GDB but may not be ready to accept connections immediately.
3005 set libthread-db-search-path
3006 show libthread-db-search-path
3007 Control list of directories which GDB will search for appropriate
3010 set schedule-multiple (on|off)
3011 show schedule-multiple
3012 Allow GDB to resume all threads of all processes or only threads of
3013 the current process.
3017 Use more aggressive caching for accesses to the stack. This improves
3018 performance of remote debugging (particularly backtraces) without
3019 affecting correctness.
3021 set interactive-mode (on|off|auto)
3022 show interactive-mode
3023 Control whether GDB runs in interactive mode (on) or not (off).
3024 When in interactive mode, GDB waits for the user to answer all
3025 queries. Otherwise, GDB does not wait and assumes the default
3026 answer. When set to auto (the default), GDB determines which
3027 mode to use based on the stdin settings.
3032 For program forks, this is replaced by the new more generic `info
3033 inferiors' command. To list checkpoints, you can still use the
3034 `info checkpoints' command, which was an alias for the `info forks'
3038 Replaced by the new `inferior' command. To switch between
3039 checkpoints, you can still use the `restart' command, which was an
3040 alias for the `fork' command.
3043 This is removed, since some targets don't have a notion of
3044 processes. To switch between processes, you can still use the
3045 `inferior' command using GDB's own inferior number.
3048 For program forks, this is replaced by the new more generic `kill
3049 inferior' command. To delete a checkpoint, you can still use the
3050 `delete checkpoint' command, which was an alias for the `delete
3054 For program forks, this is replaced by the new more generic `detach
3055 inferior' command. To detach a checkpoint, you can still use the
3056 `detach checkpoint' command, which was an alias for the `detach
3059 * New native configurations
3061 x86/x86_64 Darwin i[34567]86-*-darwin*
3063 x86_64 MinGW x86_64-*-mingw*
3067 Lattice Mico32 lm32-*
3068 x86 DICOS i[34567]86-*-dicos*
3069 x86_64 DICOS x86_64-*-dicos*
3072 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3073 (mingw32ce) debugging.
3079 These commands were actually not implemented on any target.
3081 *** Changes in GDB 6.8
3083 * New native configurations
3085 NetBSD/hppa hppa*-*netbsd*
3086 Xtensa GNU/Linux xtensa*-*-linux*
3090 NetBSD/hppa hppa*-*-netbsd*
3091 Xtensa GNU/Lunux xtensa*-*-linux*
3093 * Change in command line behavior -- corefiles vs. process ids.
3095 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3096 attaching to process NUMBER fails, GDB no longer attempts to open a
3097 core file named NUMBER. Attaching to a program using the -c option
3098 is no longer supported. Instead, use the '-p' or '--pid' options.
3100 * GDB can now be built as a native debugger for debugging Windows x86
3101 (mingw32) Portable Executable (PE) programs.
3103 * Pending breakpoints no longer change their number when their address
3106 * GDB now supports breakpoints with multiple locations,
3107 including breakpoints on C++ constructors, inside C++ templates,
3108 and in inlined functions.
3110 * GDB's ability to debug optimized code has been improved. GDB more
3111 accurately identifies function bodies and lexical blocks that occupy
3112 more than one contiguous range of addresses.
3114 * Target descriptions can now describe registers for PowerPC.
3116 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3117 registers on PowerPC targets.
3119 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3120 targets even when the libthread_db library is not available.
3122 * The GDB remote stub, gdbserver, now supports the new file transfer
3123 commands (remote put, remote get, and remote delete).
3125 * The GDB remote stub, gdbserver, now supports run and attach in
3126 extended-remote mode.
3128 * hppa*64*-*-hpux11* target broken
3129 The debugger is unable to start a program and fails with the following
3130 error: "Error trying to get information about dynamic linker".
3131 The gdb-6.7 release is also affected.
3133 * GDB now supports the --enable-targets= configure option to allow
3134 building a single GDB executable that supports multiple remote
3135 target architectures.
3137 * GDB now supports debugging C and C++ programs which use the
3138 Decimal Floating Point extension. In addition, the PowerPC target
3139 now has a set of pseudo-registers to inspect decimal float values
3140 stored in two consecutive float registers.
3142 * The -break-insert MI command can optionally create pending
3145 * Improved support for debugging Ada
3146 Many improvements to the Ada language support have been made. These
3148 - Better support for Ada2005 interface types
3149 - Improved handling of arrays and slices in general
3150 - Better support for Taft-amendment types
3151 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3153 - Improved command completion in Ada
3156 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3161 set print frame-arguments (all|scalars|none)
3162 show print frame-arguments
3163 The value of this variable can be changed to control which argument
3164 values should be printed by the debugger when displaying a frame.
3169 Transfer files to and from a remote target, and delete remote files.
3176 Transfer files to and from a remote target, and delete remote files.
3178 * New remote packets
3185 Open, close, read, write, and delete files on the remote system.
3188 Attach to an existing process on the remote system, in extended-remote
3192 Run a new process on the remote system, in extended-remote mode.
3194 *** Changes in GDB 6.7
3196 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3197 bfd, libiberty and opcodes, as revealed by static analysis donated by
3198 Coverity, Inc. (http://scan.coverity.com).
3200 * When looking up multiply-defined global symbols, GDB will now prefer the
3201 symbol definition in the current shared library if it was built using the
3202 -Bsymbolic linker option.
3204 * When the Text User Interface (TUI) is not configured, GDB will now
3205 recognize the -tui command-line option and print a message that the TUI
3208 * The GDB remote stub, gdbserver, now has lower overhead for high
3209 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3211 * GDB for MIPS targets now autodetects whether a remote target provides
3212 32-bit or 64-bit register values.
3214 * Support for C++ member pointers has been improved.
3216 * GDB now understands XML target descriptions, which specify the
3217 target's overall architecture. GDB can read a description from
3218 a local file or over the remote serial protocol.
3220 * Vectors of single-byte data use a new integer type which is not
3221 automatically displayed as character or string data.
3223 * The /s format now works with the print command. It displays
3224 arrays of single-byte integers and pointers to single-byte integers
3227 * Target descriptions can now describe target-specific registers,
3228 for architectures which have implemented the support (currently
3229 only ARM, M68K, and MIPS).
3231 * GDB and the GDB remote stub, gdbserver, now support the XScale
3234 * The GDB remote stub, gdbserver, has been updated to support
3235 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3236 has been rewritten to use the standard GDB remote protocol.
3238 * GDB can now step into C++ functions which are called through thunks.
3240 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3242 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3243 layout. It also supports a TextSeg= and DataSeg= response when only
3244 segment base addresses (rather than offsets) are available.
3246 * The /i format now outputs any trailing branch delay slot instructions
3247 immediately following the last instruction within the count specified.
3249 * The GDB remote protocol "T" stop reply packet now supports a
3250 "library" response. Combined with the new "qXfer:libraries:read"
3251 packet, this response allows GDB to debug shared libraries on targets
3252 where the operating system manages the list of loaded libraries (e.g.
3253 Windows and SymbianOS).
3255 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3256 (DLLs) on Windows and Windows CE targets.
3258 * GDB now supports a faster verification that a .debug file matches its binary
3259 according to its build-id signature, if the signature is present.
3265 Enable or disable hardware flow control (RTS/CTS) on the serial port
3266 when debugging using remote targets.
3268 set mem inaccessible-by-default
3269 show mem inaccessible-by-default
3270 If the target supplies a memory map, for instance via the remote
3271 protocol's "qXfer:memory-map:read" packet, setting this variable
3272 prevents GDB from accessing memory outside the memory map. This
3273 is useful for targets with memory mapped registers or which react
3274 badly to accesses of unmapped address space.
3276 set breakpoint auto-hw
3277 show breakpoint auto-hw
3278 If the target supplies a memory map, for instance via the remote
3279 protocol's "qXfer:memory-map:read" packet, setting this variable
3280 lets GDB use hardware breakpoints automatically for memory regions
3281 where it can not use software breakpoints. This covers both the
3282 "break" command and internal breakpoints used for other commands
3283 including "next" and "finish".
3286 catch exception unhandled
3287 Stop the program execution when Ada exceptions are raised.
3290 Stop the program execution when an Ada assertion failed.
3294 Set an alternate system root for target files. This is a more
3295 general version of "set solib-absolute-prefix", which is now
3296 an alias to "set sysroot".
3299 Provide extended SPU facility status information. This set of
3300 commands is available only when debugging the Cell/B.E. SPU
3303 * New native configurations
3305 OpenBSD/sh sh*-*openbsd*
3308 unset tdesc filename
3310 Use the specified local file as an XML target description, and do
3311 not query the target for its built-in description.
3315 OpenBSD/sh sh*-*-openbsd*
3316 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3317 Toshiba Media Processor mep-elf
3319 * New remote packets
3322 Ignore the specified signals; pass them directly to the debugged program
3323 without stopping other threads or reporting them to GDB.
3325 qXfer:features:read:
3326 Read an XML target description from the target, which describes its
3331 Read or write contents of an spufs file on the target system. These
3332 packets are available only on the Cell/B.E. SPU architecture.
3334 qXfer:libraries:read:
3335 Report the loaded shared libraries. Combined with new "T" packet
3336 response, this packet allows GDB to debug shared libraries on
3337 targets where the operating system manages the list of loaded
3338 libraries (e.g. Windows and SymbianOS).
3342 Support for these obsolete configurations has been removed.
3350 i[34567]86-*-lynxos*
3351 i[34567]86-*-netware*
3352 i[34567]86-*-sco3.2v5*
3353 i[34567]86-*-sco3.2v4*
3355 i[34567]86-*-sysv4.2*
3358 i[34567]86-*-unixware2*
3359 i[34567]86-*-unixware*
3368 * Other removed features
3375 Various m68k-only ROM monitors.
3382 Various Renesas ROM monitors and debugging interfaces for SH and
3387 Support for a Macraigor serial interface to on-chip debugging.
3388 GDB does not directly support the newer parallel or USB
3393 A debug information format. The predecessor to DWARF 2 and
3394 DWARF 3, which are still supported.
3396 Support for the HP aCC compiler on HP-UX/PA-RISC
3398 SOM-encapsulated symbolic debugging information, automatic
3399 invocation of pxdb, and the aCC custom C++ ABI. This does not
3400 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3401 with aCC can still be debugged on an assembly level.
3403 MIPS ".pdr" sections
3405 A MIPS-specific format used to describe stack frame layout
3406 in debugging information.
3410 GDB could work with an older version of Guile to debug
3411 the interpreter and Scheme programs running in it.
3413 set mips stack-arg-size
3414 set mips saved-gpreg-size
3416 Use "set mips abi" to control parameter passing for MIPS.
3418 *** Changes in GDB 6.6
3423 Cell Broadband Engine SPU spu-elf
3425 * GDB can now be configured as a cross-debugger targeting native Windows
3426 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3427 running on a Windows system over TCP/IP to debug Windows programs.
3429 * The GDB remote stub, gdbserver, has been updated to support Windows and
3430 Cygwin debugging. Both single-threaded and multi-threaded programs are
3433 * The "set trust-readonly-sections" command works again. This command was
3434 broken in GDB 6.3, 6.4, and 6.5.
3436 * The "load" command now supports writing to flash memory, if the remote
3437 stub provides the required support.
3439 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3440 longer requires symbolic debug information (e.g. DWARF-2).
3445 unset substitute-path
3446 show substitute-path
3447 Manage a list of substitution rules that GDB uses to rewrite the name
3448 of the directories where the sources are located. This can be useful
3449 for instance when the sources were moved to a different location
3450 between compilation and debugging.
3454 Print each CLI command as it is executed. Each command is prefixed with
3455 a number of `+' symbols representing the nesting depth.
3456 The source command now has a `-v' option to enable the same feature.
3460 The ARM Demon monitor support (RDP protocol, "target rdp").
3462 Kernel Object Display, an embedded debugging feature which only worked with
3463 an obsolete version of Cisco IOS.
3465 The 'set download-write-size' and 'show download-write-size' commands.
3467 * New remote packets
3470 Tell a stub about GDB client features, and request remote target features.
3471 The first feature implemented is PacketSize, which allows the target to
3472 specify the size of packets it can handle - to minimize the number of
3473 packets required and improve performance when connected to a remote
3477 Fetch an OS auxilliary vector from the remote stub. This packet is a
3478 more efficient replacement for qPart:auxv:read.
3480 qXfer:memory-map:read:
3481 Fetch a memory map from the remote stub, including information about
3482 RAM, ROM, and flash memory devices.
3487 Erase and program a flash memory device.
3489 * Removed remote packets
3492 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3493 used it, and only gdbserver implemented it.
3495 *** Changes in GDB 6.5
3499 Renesas M32C/M16C m32c-elf
3501 Morpho Technologies ms1 ms1-elf
3505 init-if-undefined Initialize a convenience variable, but
3506 only if it doesn't already have a value.
3508 The following commands are presently only implemented for native GNU/Linux:
3510 checkpoint Save a snapshot of the program state.
3512 restart <n> Return the program state to a
3513 previously saved state.
3515 info checkpoints List currently saved checkpoints.
3517 delete-checkpoint <n> Delete a previously saved checkpoint.
3519 set|show detach-on-fork Tell gdb whether to detach from a newly
3520 forked process, or to keep debugging it.
3522 info forks List forks of the user program that
3523 are available to be debugged.
3525 fork <n> Switch to debugging one of several
3526 forks of the user program that are
3527 available to be debugged.
3529 delete-fork <n> Delete a fork from the list of forks
3530 that are available to be debugged (and
3531 kill the forked process).
3533 detach-fork <n> Delete a fork from the list of forks
3534 that are available to be debugged (and
3535 allow the process to continue).
3539 Morpho Technologies ms2 ms1-elf
3541 * Improved Windows host support
3543 GDB now builds as a cross debugger hosted on i686-mingw32, including
3544 native console support, and remote communications using either
3545 network sockets or serial ports.
3547 * Improved Modula-2 language support
3549 GDB can now print most types in the Modula-2 syntax. This includes:
3550 basic types, set types, record types, enumerated types, range types,
3551 pointer types and ARRAY types. Procedure var parameters are correctly
3552 printed and hexadecimal addresses and character constants are also
3553 written in the Modula-2 syntax. Best results can be obtained by using
3554 GNU Modula-2 together with the -gdwarf-2 command line option.
3558 The ARM rdi-share module.
3560 The Netware NLM debug server.
3562 *** Changes in GDB 6.4
3564 * New native configurations
3566 OpenBSD/arm arm*-*-openbsd*
3567 OpenBSD/mips64 mips64-*-openbsd*
3571 Morpho Technologies ms1 ms1-elf
3573 * New command line options
3575 --batch-silent As for --batch, but totally silent.
3576 --return-child-result The debugger will exist with the same value
3577 the child (debugged) program exited with.
3578 --eval-command COMMAND, -ex COMMAND
3579 Execute a single GDB CLI command. This may be
3580 specified multiple times and in conjunction
3581 with the --command (-x) option.
3583 * Deprecated commands removed
3585 The following commands, that were deprecated in 2000, have been
3589 set|show arm disassembly-flavor set|show arm disassembler
3590 othernames set arm disassembler
3591 set|show remotedebug set|show debug remote
3592 set|show archdebug set|show debug arch
3593 set|show eventdebug set|show debug event
3596 * New BSD user-level threads support
3598 It is now possible to debug programs using the user-level threads
3599 library on OpenBSD and FreeBSD. Currently supported (target)
3602 FreeBSD/amd64 x86_64-*-freebsd*
3603 FreeBSD/i386 i386-*-freebsd*
3604 OpenBSD/i386 i386-*-openbsd*
3606 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3607 are not yet supported.
3609 * New support for Matsushita MN10300 w/sim added
3610 (Work in progress). mn10300-elf.
3612 * REMOVED configurations and files
3614 VxWorks and the XDR protocol *-*-vxworks
3615 Motorola MCORE mcore-*-*
3616 National Semiconductor NS32000 ns32k-*-*
3618 * New "set print array-indexes" command
3620 After turning this setting "on", GDB prints the index of each element
3621 when displaying arrays. The default is "off" to preserve the previous
3624 * VAX floating point support
3626 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3628 * User-defined command support
3630 In addition to using $arg0..$arg9 for argument passing, it is now possible
3631 to use $argc to determine now many arguments have been passed. See the
3632 section on user-defined commands in the user manual for more information.
3634 *** Changes in GDB 6.3:
3636 * New command line option
3638 GDB now accepts -l followed by a number to set the timeout for remote
3641 * GDB works with GCC -feliminate-dwarf2-dups
3643 GDB now supports a more compact representation of DWARF-2 debug
3644 information using DW_FORM_ref_addr references. These are produced
3645 by GCC with the option -feliminate-dwarf2-dups and also by some
3646 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3647 to use -feliminate-dwarf2-dups.
3649 * Internationalization
3651 When supported by the host system, GDB will be built with
3652 internationalization (libintl). The task of marking up the sources is
3653 continued, we're looking forward to our first translation.
3657 Initial support for debugging programs compiled with the GNAT
3658 implementation of the Ada programming language has been integrated
3659 into GDB. In this release, support is limited to expression evaluation.
3661 * New native configurations
3663 GNU/Linux/m32r m32r-*-linux-gnu
3667 GDB's remote protocol now includes support for the 'p' packet. This
3668 packet is used to fetch individual registers from a remote inferior.
3670 * END-OF-LIFE registers[] compatibility module
3672 GDB's internal register infrastructure has been completely rewritten.
3673 The new infrastructure making possible the implementation of key new
3674 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3677 GDB 6.3 will be the last release to include the the registers[]
3678 compatibility module that allowed out-of-date configurations to
3679 continue to work. This change directly impacts the following
3689 powerpc bdm protocol
3691 Unless there is activity to revive these configurations, they will be
3692 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3694 * OBSOLETE configurations and files
3696 Configurations that have been declared obsolete in this release have
3697 been commented out. Unless there is activity to revive these
3698 configurations, the next release of GDB will have their sources
3699 permanently REMOVED.
3708 *** Changes in GDB 6.2.1:
3710 * MIPS `break main; run' gave an heuristic-fence-post warning
3712 When attempting to run even a simple program, a warning about
3713 heuristic-fence-post being hit would be reported. This problem has
3716 * MIPS IRIX 'long double' crashed GDB
3718 When examining a long double variable, GDB would get a segmentation
3719 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3720 IRIX long double values).
3724 A bug in the VAX stack code was causing problems with the "next"
3725 command. This problem has been fixed.
3727 *** Changes in GDB 6.2:
3729 * Fix for ``many threads''
3731 On GNU/Linux systems that use the NPTL threads library, a program
3732 rapidly creating and deleting threads would confuse GDB leading to the
3735 ptrace: No such process.
3736 thread_db_get_info: cannot get thread info: generic error
3738 This problem has been fixed.
3740 * "-async" and "-noasync" options removed.
3742 Support for the broken "-noasync" option has been removed (it caused
3745 * New ``start'' command.
3747 This command runs the program until the begining of the main procedure.
3749 * New BSD Kernel Data Access Library (libkvm) interface
3751 Using ``target kvm'' it is now possible to debug kernel core dumps and
3752 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3753 platforms. Currently supported (native-only) configurations are:
3755 FreeBSD/amd64 x86_64-*-freebsd*
3756 FreeBSD/i386 i?86-*-freebsd*
3757 NetBSD/i386 i?86-*-netbsd*
3758 NetBSD/m68k m68*-*-netbsd*
3759 NetBSD/sparc sparc-*-netbsd*
3760 OpenBSD/amd64 x86_64-*-openbsd*
3761 OpenBSD/i386 i?86-*-openbsd*
3762 OpenBSD/m68k m68*-openbsd*
3763 OpenBSD/sparc sparc-*-openbsd*
3765 * Signal trampoline code overhauled
3767 Many generic problems with GDB's signal handling code have been fixed.
3768 These include: backtraces through non-contiguous stacks; recognition
3769 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3770 call; backtrace through a signal trampoline; step into and out of
3771 signal handlers; and single-stepping in the signal trampoline.
3773 Please note that kernel bugs are a limiting factor here. These
3774 features have been shown to work on an s390 GNU/Linux system that
3775 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3777 * Cygwin support for DWARF 2 added.
3779 * New native configurations
3781 GNU/Linux/hppa hppa*-*-linux*
3782 OpenBSD/hppa hppa*-*-openbsd*
3783 OpenBSD/m68k m68*-*-openbsd*
3784 OpenBSD/m88k m88*-*-openbsd*
3785 OpenBSD/powerpc powerpc-*-openbsd*
3786 NetBSD/vax vax-*-netbsd*
3787 OpenBSD/vax vax-*-openbsd*
3789 * END-OF-LIFE frame compatibility module
3791 GDB's internal frame infrastructure has been completely rewritten.
3792 The new infrastructure making it possible to support key new features
3793 including DWARF 2 Call Frame Information. To aid in the task of
3794 migrating old configurations to this new infrastructure, a
3795 compatibility module, that allowed old configurations to continue to
3796 work, was also included.
3798 GDB 6.2 will be the last release to include this frame compatibility
3799 module. This change directly impacts the following configurations:
3809 Unless there is activity to revive these configurations, they will be
3810 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3812 * REMOVED configurations and files
3814 Sun 3, running SunOS 3 m68*-*-sunos3*
3815 Sun 3, running SunOS 4 m68*-*-sunos4*
3816 Sun 2, running SunOS 3 m68000-*-sunos3*
3817 Sun 2, running SunOS 4 m68000-*-sunos4*
3818 Motorola 680x0 running LynxOS m68*-*-lynxos*
3819 AT&T 3b1/Unix pc m68*-att-*
3820 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3821 decstation mips-dec-* mips-little-*
3822 riscos mips-*-riscos* mips-*-sysv*
3823 sonymips mips-sony-*
3824 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3826 *** Changes in GDB 6.1.1:
3828 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3830 The TUI (Text-mode User Interface) is now built as part of a default
3831 GDB configuration. It is enabled by either selecting the TUI with the
3832 command line option "-i=tui" or by running the separate "gdbtui"
3833 program. For more information on the TUI, see the manual "Debugging
3836 * Pending breakpoint support (also included in GDB 6.1)
3838 Support has been added to allow you to specify breakpoints in shared
3839 libraries that have not yet been loaded. If a breakpoint location
3840 cannot be found, and the "breakpoint pending" option is set to auto,
3841 GDB queries you if you wish to make the breakpoint pending on a future
3842 shared-library load. If and when GDB resolves the breakpoint symbol,
3843 the pending breakpoint is removed as one or more regular breakpoints
3846 Pending breakpoints are very useful for GCJ Java debugging.
3848 * Fixed ISO-C build problems
3850 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3851 non ISO-C code that stopped them being built using a more strict ISO-C
3852 compiler (e.g., IBM's C compiler).
3854 * Fixed build problem on IRIX 5
3856 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3857 wasn't able to compile compile on an IRIX 5 system.
3859 * Added execute permission to gdb/gdbserver/configure
3861 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3862 permission. This bug would cause configure to fail on a number of
3863 systems (Solaris, IRIX). Ref: server/519.
3865 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3867 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3868 has been updated to use constant array sizes.
3870 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3872 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3873 its generated DWARF Call Frame Info. This encoding was causing GDB to
3874 panic, that panic has been fixed. Ref: gdb/1628.
3876 * Fixed a problem when examining parameters in shared library code.
3878 When examining parameters in optimized shared library code generated
3879 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3880 not available''. GDB now correctly displays the variable's value.
3882 *** Changes in GDB 6.1:
3884 * Removed --with-mmalloc
3886 Support for the mmalloc memory manager has been removed, as it
3887 conflicted with the internal gdb byte cache.
3889 * Changes in AMD64 configurations
3891 The AMD64 target now includes the %cs and %ss registers. As a result
3892 the AMD64 remote protocol has changed; this affects the floating-point
3893 and SSE registers. If you rely on those registers for your debugging,
3894 you should upgrade gdbserver on the remote side.
3896 * Revised SPARC target
3898 The SPARC target has been completely revised, incorporating the
3899 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3900 support for LynxOS and SunOS 4 has been dropped. Calling functions
3901 from within GDB on operating systems with a non-executable stack
3902 (Solaris, OpenBSD) now works.
3906 GDB has a new C++ demangler which does a better job on the mangled
3907 names generated by current versions of g++. It also runs faster, so
3908 with this and other changes gdb should now start faster on large C++
3911 * DWARF 2 Location Expressions
3913 GDB support for location expressions has been extended to support function
3914 arguments and frame bases. Older versions of GDB could crash when they
3917 * C++ nested types and namespaces
3919 GDB's support for nested types and namespaces in C++ has been
3920 improved, especially if you use the DWARF 2 debugging format. (This
3921 is the default for recent versions of GCC on most platforms.)
3922 Specifically, if you have a class "Inner" defined within a class or
3923 namespace "Outer", then GDB realizes that the class's name is
3924 "Outer::Inner", not simply "Inner". This should greatly reduce the
3925 frequency of complaints about not finding RTTI symbols. In addition,
3926 if you are stopped at inside of a function defined within a namespace,
3927 GDB modifies its name lookup accordingly.
3929 * New native configurations
3931 NetBSD/amd64 x86_64-*-netbsd*
3932 OpenBSD/amd64 x86_64-*-openbsd*
3933 OpenBSD/alpha alpha*-*-openbsd*
3934 OpenBSD/sparc sparc-*-openbsd*
3935 OpenBSD/sparc64 sparc64-*-openbsd*
3937 * New debugging protocols
3939 M32R with SDI protocol m32r-*-elf*
3941 * "set prompt-escape-char" command deleted.
3943 The command "set prompt-escape-char" has been deleted. This command,
3944 and its very obscure effet on GDB's prompt, was never documented,
3945 tested, nor mentioned in the NEWS file.
3947 * OBSOLETE configurations and files
3949 Configurations that have been declared obsolete in this release have
3950 been commented out. Unless there is activity to revive these
3951 configurations, the next release of GDB will have their sources
3952 permanently REMOVED.
3954 Sun 3, running SunOS 3 m68*-*-sunos3*
3955 Sun 3, running SunOS 4 m68*-*-sunos4*
3956 Sun 2, running SunOS 3 m68000-*-sunos3*
3957 Sun 2, running SunOS 4 m68000-*-sunos4*
3958 Motorola 680x0 running LynxOS m68*-*-lynxos*
3959 AT&T 3b1/Unix pc m68*-att-*
3960 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3961 decstation mips-dec-* mips-little-*
3962 riscos mips-*-riscos* mips-*-sysv*
3963 sonymips mips-sony-*
3964 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3966 * REMOVED configurations and files
3968 SGI Irix-4.x mips-sgi-irix4 or iris4
3969 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3970 Z8000 simulator z8k-zilog-none or z8ksim
3971 Matsushita MN10200 w/simulator mn10200-*-*
3972 H8/500 simulator h8500-hitachi-hms or h8500hms
3973 HP/PA running BSD hppa*-*-bsd*
3974 HP/PA running OSF/1 hppa*-*-osf*
3975 HP/PA Pro target hppa*-*-pro*
3976 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3977 386BSD i[3456]86-*-bsd*
3978 Sequent family i[3456]86-sequent-sysv4*
3979 i[3456]86-sequent-sysv*
3980 i[3456]86-sequent-bsd*
3981 SPARC running LynxOS sparc-*-lynxos*
3982 SPARC running SunOS 4 sparc-*-sunos4*
3983 Tsqware Sparclet sparclet-*-*
3984 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3986 *** Changes in GDB 6.0:
3990 Support for debugging the Objective-C programming language has been
3991 integrated into GDB.
3993 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3995 DWARF 2's Call Frame Information makes available compiler generated
3996 information that more exactly describes the program's run-time stack.
3997 By using this information, GDB is able to provide more robust stack
4000 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4001 have been updated to use a new backtrace mechanism which includes
4002 DWARF 2 CFI support.
4006 GDB's remote protocol has been extended to include support for hosted
4007 file I/O (where the remote target uses GDB's file system). See GDB's
4008 remote protocol documentation for details.
4010 * All targets using the new architecture framework.
4012 All of GDB's targets have been updated to use the new internal
4013 architecture framework. The way is now open for future GDB releases
4014 to include cross-architecture native debugging support (i386 on amd64,
4017 * GNU/Linux's Thread Local Storage (TLS)
4019 GDB now includes support for for the GNU/Linux implementation of
4020 per-thread variables.
4022 * GNU/Linux's Native POSIX Thread Library (NPTL)
4024 GDB's thread code has been updated to work with either the new
4025 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4027 * Separate debug info.
4029 GDB, in conjunction with BINUTILS, now supports a mechanism for
4030 automatically loading debug information from a separate file. Instead
4031 of shipping full debug and non-debug versions of system libraries,
4032 system integrators can now instead ship just the stripped libraries
4033 and optional debug files.
4035 * DWARF 2 Location Expressions
4037 DWARF 2 Location Expressions allow the compiler to more completely
4038 describe the location of variables (even in optimized code) to the
4041 GDB now includes preliminary support for location expressions (support
4042 for DW_OP_piece is still missing).
4046 A number of long standing bugs that caused GDB to die while starting a
4047 Java application have been fixed. GDB's Java support is now
4048 considered "useable".
4050 * GNU/Linux support for fork, vfork, and exec.
4052 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4053 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4056 * GDB supports logging output to a file
4058 There are two new commands, "set logging" and "show logging", which can be
4059 used to capture GDB's output to a file.
4061 * The meaning of "detach" has changed for gdbserver
4063 The "detach" command will now resume the application, as documented. To
4064 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4067 * d10v, m68hc11 `regs' command deprecated
4069 The `info registers' command has been updated so that it displays the
4070 registers using a format identical to the old `regs' command.
4074 A new command, "maint set profile on/off", has been added. This command can
4075 be used to enable or disable profiling while running GDB, to profile a
4076 session or a set of commands. In addition there is a new configure switch,
4077 "--enable-profiling", which will cause GDB to be compiled with profiling
4078 data, for more informative profiling results.
4080 * Default MI syntax changed to "mi2".
4082 The default MI (machine interface) syntax, enabled by the command line
4083 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4084 "mi1", can be enabled by specifying the option "-i=mi1".
4086 Support for the original "mi0" syntax (included in GDB 5.0) has been
4089 Fix for gdb/192: removed extraneous space when displaying frame level.
4090 Fix for gdb/672: update changelist is now output in mi list format.
4091 Fix for gdb/702: a -var-assign that updates the value now shows up
4092 in a subsequent -var-update.
4094 * New native configurations.
4096 FreeBSD/amd64 x86_64-*-freebsd*
4098 * Multi-arched targets.
4100 HP/PA HPUX11 hppa*-*-hpux*
4101 Renesas M32R/D w/simulator m32r-*-elf*
4103 * OBSOLETE configurations and files
4105 Configurations that have been declared obsolete in this release have
4106 been commented out. Unless there is activity to revive these
4107 configurations, the next release of GDB will have their sources
4108 permanently REMOVED.
4110 Z8000 simulator z8k-zilog-none or z8ksim
4111 Matsushita MN10200 w/simulator mn10200-*-*
4112 H8/500 simulator h8500-hitachi-hms or h8500hms
4113 HP/PA running BSD hppa*-*-bsd*
4114 HP/PA running OSF/1 hppa*-*-osf*
4115 HP/PA Pro target hppa*-*-pro*
4116 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4117 Sequent family i[3456]86-sequent-sysv4*
4118 i[3456]86-sequent-sysv*
4119 i[3456]86-sequent-bsd*
4120 Tsqware Sparclet sparclet-*-*
4121 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4123 * REMOVED configurations and files
4126 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4127 IBM AIX PS/2 i[3456]86-*-aix
4128 i386 running Mach 3.0 i[3456]86-*-mach3*
4129 i386 running Mach i[3456]86-*-mach*
4130 i386 running OSF/1 i[3456]86-*osf1mk*
4131 HP/Apollo 68k Family m68*-apollo*-sysv*,
4133 m68*-hp-bsd*, m68*-hp-hpux*
4134 Argonaut Risc Chip (ARC) arc-*-*
4135 Mitsubishi D30V d30v-*-*
4136 Fujitsu FR30 fr30-*-elf*
4137 OS/9000 i[34]86-*-os9k
4138 I960 with MON960 i960-*-coff
4140 * MIPS $fp behavior changed
4142 The convenience variable $fp, for the MIPS, now consistently returns
4143 the address of the current frame's base. Previously, depending on the
4144 context, $fp could refer to either $sp or the current frame's base
4145 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4146 The GNU Source-Level Debugger''.
4148 *** Changes in GDB 5.3:
4150 * GNU/Linux shared library multi-threaded performance improved.
4152 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4153 `/proc', in preference to `ptrace' for memory reads. This may result
4154 in an improvement in the start-up time of multi-threaded, shared
4155 library applications when run under GDB. One GDB user writes: ``loads
4156 shared libs like mad''.
4158 * ``gdbserver'' now supports multi-threaded applications on some targets
4160 Support for debugging multi-threaded applications which use
4161 the GNU/Linux LinuxThreads package has been added for
4162 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4163 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4165 * GDB now supports C/C++ preprocessor macros.
4167 GDB now expands preprocessor macro invocations in C/C++ expressions,
4168 and provides various commands for showing macro definitions and how
4171 The new command `macro expand EXPRESSION' expands any macro
4172 invocations in expression, and shows the result.
4174 The new command `show macro MACRO-NAME' shows the definition of the
4175 macro named MACRO-NAME, and where it was defined.
4177 Most compilers don't include information about macros in the debugging
4178 information by default. In GCC 3.1, for example, you need to compile
4179 your program with the options `-gdwarf-2 -g3'. If the macro
4180 information is present in the executable, GDB will read it.
4182 * Multi-arched targets.
4184 DEC Alpha (partial) alpha*-*-*
4185 DEC VAX (partial) vax-*-*
4187 National Semiconductor NS32000 (partial) ns32k-*-*
4188 Motorola 68000 (partial) m68k-*-*
4189 Motorola MCORE mcore-*-*
4193 Fujitsu FRV architecture added by Red Hat frv*-*-*
4196 * New native configurations
4198 Alpha NetBSD alpha*-*-netbsd*
4199 SH NetBSD sh*-*-netbsdelf*
4200 MIPS NetBSD mips*-*-netbsd*
4201 UltraSPARC NetBSD sparc64-*-netbsd*
4203 * OBSOLETE configurations and files
4205 Configurations that have been declared obsolete in this release have
4206 been commented out. Unless there is activity to revive these
4207 configurations, the next release of GDB will have their sources
4208 permanently REMOVED.
4210 Mitsubishi D30V d30v-*-*
4211 OS/9000 i[34]86-*-os9k
4212 IBM AIX PS/2 i[3456]86-*-aix
4213 Fujitsu FR30 fr30-*-elf*
4214 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4215 Argonaut Risc Chip (ARC) arc-*-*
4216 i386 running Mach 3.0 i[3456]86-*-mach3*
4217 i386 running Mach i[3456]86-*-mach*
4218 i386 running OSF/1 i[3456]86-*osf1mk*
4219 HP/Apollo 68k Family m68*-apollo*-sysv*,
4221 m68*-hp-bsd*, m68*-hp-hpux*
4222 I960 with MON960 i960-*-coff
4224 * OBSOLETE languages
4226 CHILL, a Pascal like language used by telecommunications companies.
4228 * REMOVED configurations and files
4230 AMD 29k family via UDI a29k-amd-udi, udi29k
4231 A29K VxWorks a29k-*-vxworks
4232 AMD 29000 embedded, using EBMON a29k-none-none
4233 AMD 29000 embedded with COFF a29k-none-coff
4234 AMD 29000 embedded with a.out a29k-none-aout
4236 testsuite/gdb.hp/gdb.threads-hp/ directory
4238 * New command "set max-user-call-depth <nnn>"
4240 This command allows the user to limit the call depth of user-defined
4241 commands. The default is 1024.
4243 * Changes in FreeBSD/i386 native debugging.
4245 Support for the "generate-core-file" has been added.
4247 * New commands "dump", "append", and "restore".
4249 These commands allow data to be copied from target memory
4250 to a bfd-format or binary file (dump and append), and back
4251 from a file into memory (restore).
4253 * Improved "next/step" support on multi-processor Alpha Tru64.
4255 The previous single-step mechanism could cause unpredictable problems,
4256 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4257 of a software single-step mechanism prevents this.
4259 *** Changes in GDB 5.2.1:
4267 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4268 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4269 Fix, by Joel Brobecker imported from mainline.
4271 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4272 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4273 Fix, by Fred Fish, imported from mainline.
4275 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4276 Surprisingly enough, it works now.
4277 By Michal Ludvig, imported from mainline.
4279 i386 hardware watchpoint support:
4280 avoid misses on second run for some targets.
4281 By Pierre Muller, imported from mainline.
4283 *** Changes in GDB 5.2:
4285 * New command "set trust-readonly-sections on[off]".
4287 This command is a hint that tells gdb that read-only sections
4288 really are read-only (ie. that their contents will not change).
4289 In this mode, gdb will go to the object file rather than the
4290 target to read memory from read-only sections (such as ".text").
4291 This can be a significant performance improvement on some
4292 (notably embedded) targets.
4294 * New command "generate-core-file" (or "gcore").
4296 This new gdb command allows the user to drop a core file of the child
4297 process state at any time. So far it's been implemented only for
4298 GNU/Linux and Solaris, but should be relatively easily ported to other
4299 hosts. Argument is core file name (defaults to core.<pid>).
4301 * New command line option
4303 GDB now accepts --pid or -p followed by a process id.
4305 * Change in command line behavior -- corefiles vs. process ids.
4307 There is a subtle behavior in the way in which GDB handles
4308 command line arguments. The first non-flag argument is always
4309 a program to debug, but the second non-flag argument may either
4310 be a corefile or a process id. Previously, GDB would attempt to
4311 open the second argument as a corefile, and if that failed, would
4312 issue a superfluous error message and then attempt to attach it as
4313 a process. Now, if the second argument begins with a non-digit,
4314 it will be treated as a corefile. If it begins with a digit,
4315 GDB will attempt to attach it as a process, and if no such process
4316 is found, will then attempt to open it as a corefile.
4318 * Changes in ARM configurations.
4320 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4321 configuration is fully multi-arch.
4323 * New native configurations
4325 ARM NetBSD arm*-*-netbsd*
4326 x86 OpenBSD i[3456]86-*-openbsd*
4327 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4328 Sparc64 running FreeBSD sparc64-*-freebsd*
4332 Sanyo XStormy16 xstormy16-elf
4334 * OBSOLETE configurations and files
4336 Configurations that have been declared obsolete in this release have
4337 been commented out. Unless there is activity to revive these
4338 configurations, the next release of GDB will have their sources
4339 permanently REMOVED.
4341 AMD 29k family via UDI a29k-amd-udi, udi29k
4342 A29K VxWorks a29k-*-vxworks
4343 AMD 29000 embedded, using EBMON a29k-none-none
4344 AMD 29000 embedded with COFF a29k-none-coff
4345 AMD 29000 embedded with a.out a29k-none-aout
4347 testsuite/gdb.hp/gdb.threads-hp/ directory
4349 * REMOVED configurations and files
4351 TI TMS320C80 tic80-*-*
4353 PowerPC Solaris powerpcle-*-solaris*
4354 PowerPC Windows NT powerpcle-*-cygwin32
4355 PowerPC Netware powerpc-*-netware*
4356 Harris/CXUX m88k m88*-harris-cxux*
4357 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4358 ns32k-utek-sysv* ns32k-utek-*
4359 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4360 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4361 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4362 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4363 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4365 * Changes to command line processing
4367 The new `--args' feature can be used to specify command-line arguments
4368 for the inferior from gdb's command line.
4370 * Changes to key bindings
4372 There is a new `operate-and-get-next' function bound to `C-o'.
4374 *** Changes in GDB 5.1.1
4376 Fix compile problem on DJGPP.
4378 Fix a problem with floating-point registers on the i386 being
4381 Fix to stop GDB crashing on .debug_str debug info.
4383 Numerous documentation fixes.
4385 Numerous testsuite fixes.
4387 *** Changes in GDB 5.1:
4389 * New native configurations
4391 Alpha FreeBSD alpha*-*-freebsd*
4392 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4393 MIPS GNU/Linux mips*-*-linux*
4394 MIPS SGI Irix 6.x mips*-sgi-irix6*
4395 ia64 AIX ia64-*-aix*
4396 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4400 Motorola 68HC11 and 68HC12 m68hc11-elf
4402 UltraSparc running GNU/Linux sparc64-*-linux*
4404 * OBSOLETE configurations and files
4406 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4407 Harris/CXUX m88k m88*-harris-cxux*
4408 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4409 ns32k-utek-sysv* ns32k-utek-*
4410 TI TMS320C80 tic80-*-*
4412 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4413 PowerPC Solaris powerpcle-*-solaris*
4414 PowerPC Windows NT powerpcle-*-cygwin32
4415 PowerPC Netware powerpc-*-netware*
4416 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4417 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4418 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4419 Apple Macintosh (MPW) host N/A
4421 stuff.c (Program to stuff files into a specially prepared space in kdb)
4422 kdb-start.c (Main loop for the standalone kernel debugger)
4424 Configurations that have been declared obsolete in this release have
4425 been commented out. Unless there is activity to revive these
4426 configurations, the next release of GDB will have their sources
4427 permanently REMOVED.
4429 * REMOVED configurations and files
4431 Altos 3068 m68*-altos-*
4432 Convex c1-*-*, c2-*-*
4434 ARM RISCix arm-*-* (as host)
4438 * GDB has been converted to ISO C.
4440 GDB's source code has been converted to ISO C. In particular, the
4441 sources are fully protoized, and rely on standard headers being
4446 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4448 * The MI enabled by default.
4450 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4451 revised and enabled by default. Packages which use GDB as a debugging
4452 engine behind a UI or another front end are encouraged to switch to
4453 using the GDB/MI interface, instead of the old annotations interface
4454 which is now deprecated.
4456 * Support for debugging Pascal programs.
4458 GDB now includes support for debugging Pascal programs. The following
4459 main features are supported:
4461 - Pascal-specific data types such as sets;
4463 - automatic recognition of Pascal sources based on file-name
4466 - Pascal-style display of data types, variables, and functions;
4468 - a Pascal expression parser.
4470 However, some important features are not yet supported.
4472 - Pascal string operations are not supported at all;
4474 - there are some problems with boolean types;
4476 - Pascal type hexadecimal constants are not supported
4477 because they conflict with the internal variables format;
4479 - support for Pascal objects and classes is not full yet;
4481 - unlike Pascal, GDB is case-sensitive for symbol names.
4483 * Changes in completion.
4485 Commands such as `shell', `run' and `set args', which pass arguments
4486 to inferior programs, now complete on file names, similar to what
4487 users expect at the shell prompt.
4489 Commands which accept locations, such as `disassemble', `print',
4490 `breakpoint', `until', etc. now complete on filenames as well as
4491 program symbols. Thus, if you type "break foob TAB", and the source
4492 files linked into the programs include `foobar.c', that file name will
4493 be one of the candidates for completion. However, file names are not
4494 considered for completion after you typed a colon that delimits a file
4495 name from a name of a function in that file, as in "break foo.c:bar".
4497 `set demangle-style' completes on available demangling styles.
4499 * New platform-independent commands:
4501 It is now possible to define a post-hook for a command as well as a
4502 hook that runs before the command. For more details, see the
4503 documentation of `hookpost' in the GDB manual.
4505 * Changes in GNU/Linux native debugging.
4507 Support for debugging multi-threaded programs has been completely
4508 revised for all platforms except m68k and sparc. You can now debug as
4509 many threads as your system allows you to have.
4511 Attach/detach is supported for multi-threaded programs.
4513 Support for SSE registers was added for x86. This doesn't work for
4514 multi-threaded programs though.
4516 * Changes in MIPS configurations.
4518 Multi-arch support is enabled for all MIPS configurations.
4520 GDB can now be built as native debugger on SGI Irix 6.x systems for
4521 debugging n32 executables. (Debugging 64-bit executables is not yet
4524 * Unified support for hardware watchpoints in all x86 configurations.
4526 Most (if not all) native x86 configurations support hardware-assisted
4527 breakpoints and watchpoints in a unified manner. This support
4528 implements debug register sharing between watchpoints, which allows to
4529 put a virtually infinite number of watchpoints on the same address,
4530 and also supports watching regions up to 16 bytes with several debug
4533 The new maintenance command `maintenance show-debug-regs' toggles
4534 debugging print-outs in functions that insert, remove, and test
4535 watchpoints and hardware breakpoints.
4537 * Changes in the DJGPP native configuration.
4539 New command ``info dos sysinfo'' displays assorted information about
4540 the CPU, OS, memory, and DPMI server.
4542 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4543 display information about segment descriptors stored in GDT, LDT, and
4546 New commands ``info dos pde'' and ``info dos pte'' display entries
4547 from Page Directory and Page Tables (for now works with CWSDPMI only).
4548 New command ``info dos address-pte'' displays the Page Table entry for
4549 a given linear address.
4551 GDB can now pass command lines longer than 126 characters to the
4552 program being debugged (requires an update to the libdbg.a library
4553 which is part of the DJGPP development kit).
4555 DWARF2 debug info is now supported.
4557 It is now possible to `step' and `next' through calls to `longjmp'.
4559 * Changes in documentation.
4561 All GDB documentation was converted to GFDL, the GNU Free
4562 Documentation License.
4564 Tracepoints-related commands are now fully documented in the GDB
4567 TUI, the Text-mode User Interface, is now documented in the manual.
4569 Tracepoints-related commands are now fully documented in the GDB
4572 The "GDB Internals" manual now has an index. It also includes
4573 documentation of `ui_out' functions, GDB coding standards, x86
4574 hardware watchpoints, and memory region attributes.
4576 * GDB's version number moved to ``version.in''
4578 The Makefile variable VERSION has been replaced by the file
4579 ``version.in''. People creating GDB distributions should update the
4580 contents of this file.
4584 GUD support is now a standard part of the EMACS distribution.
4586 *** Changes in GDB 5.0:
4588 * Improved support for debugging FP programs on x86 targets
4590 Unified and much-improved support for debugging floating-point
4591 programs on all x86 targets. In particular, ``info float'' now
4592 displays the FP registers in the same format on all x86 targets, with
4593 greater level of detail.
4595 * Improvements and bugfixes in hardware-assisted watchpoints
4597 It is now possible to watch array elements, struct members, and
4598 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4599 on x86 targets no longer erroneously trigger when the address is
4602 * Improvements in the native DJGPP version of GDB
4604 The distribution now includes all the scripts and auxiliary files
4605 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4606 machines ``out of the box''.
4608 The DJGPP version can now debug programs that use signals. It is
4609 possible to catch signals that happened in the debuggee, deliver
4610 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4611 would kill the program being debugged.) Programs that hook hardware
4612 interrupts (keyboard, timer, etc.) can also be debugged.
4614 It is now possible to debug DJGPP programs that redirect their
4615 standard handles or switch them to raw (as opposed to cooked) mode, or
4616 even close them. The command ``run < foo > bar'' works as expected,
4617 and ``info terminal'' reports useful information about the debuggee's
4618 terminal, including raw/cooked mode, redirection, etc.
4620 The DJGPP version now uses termios functions for console I/O, which
4621 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4624 DOS-style file names with drive letters are now fully supported by
4627 It is now possible to debug DJGPP programs that switch their working
4628 directory. It is also possible to rerun the debuggee any number of
4629 times without restarting GDB; thus, you can use the same setup,
4630 breakpoints, etc. for many debugging sessions.
4632 * New native configurations
4634 ARM GNU/Linux arm*-*-linux*
4635 PowerPC GNU/Linux powerpc-*-linux*
4639 Motorola MCore mcore-*-*
4640 x86 VxWorks i[3456]86-*-vxworks*
4641 PowerPC VxWorks powerpc-*-vxworks*
4642 TI TMS320C80 tic80-*-*
4644 * OBSOLETE configurations
4646 Altos 3068 m68*-altos-*
4647 Convex c1-*-*, c2-*-*
4649 ARM RISCix arm-*-* (as host)
4652 Configurations that have been declared obsolete will be commented out,
4653 but the code will be left in place. If there is no activity to revive
4654 these configurations before the next release of GDB, the sources will
4655 be permanently REMOVED.
4657 * Gould support removed
4659 Support for the Gould PowerNode and NP1 has been removed.
4661 * New features for SVR4
4663 On SVR4 native platforms (such as Solaris), if you attach to a process
4664 without first loading a symbol file, GDB will now attempt to locate and
4665 load symbols from the running process's executable file.
4667 * Many C++ enhancements
4669 C++ support has been greatly improved. Overload resolution now works properly
4670 in almost all cases. RTTI support is on the way.
4672 * Remote targets can connect to a sub-program
4674 A popen(3) style serial-device has been added. This device starts a
4675 sub-process (such as a stand-alone simulator) and then communicates
4676 with that. The sub-program to run is specified using the syntax
4677 ``|<program> <args>'' vis:
4679 (gdb) set remotedebug 1
4680 (gdb) target extended-remote |mn10300-elf-sim program-args
4682 * MIPS 64 remote protocol
4684 A long standing bug in the mips64 remote protocol where by GDB
4685 expected certain 32 bit registers (ex SR) to be transfered as 32
4686 instead of 64 bits has been fixed.
4688 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4689 added to provide backward compatibility with older versions of GDB.
4691 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4693 The command ``set remotebinarydownload'' command has been replaced by
4694 ``set remote X-packet''. Other commands in ``set remote'' family
4695 include ``set remote P-packet''.
4697 * Breakpoint commands accept ranges.
4699 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4700 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4701 ``tracepoint passcount'' also accepts a range of tracepoints.
4703 * ``apropos'' command added.
4705 The ``apropos'' command searches through command names and
4706 documentation strings, printing out matches, making it much easier to
4707 try to find a command that does what you are looking for.
4711 A new machine oriented interface (MI) has been added to GDB. This
4712 interface is designed for debug environments running GDB as a separate
4713 process. This is part of the long term libGDB project. See the
4714 "GDB/MI" chapter of the GDB manual for further information. It can be
4715 enabled by configuring with:
4717 .../configure --enable-gdbmi
4719 *** Changes in GDB-4.18:
4721 * New native configurations
4723 HP-UX 10.20 hppa*-*-hpux10.20
4724 HP-UX 11.x hppa*-*-hpux11.0*
4725 M68K GNU/Linux m68*-*-linux*
4729 Fujitsu FR30 fr30-*-elf*
4730 Intel StrongARM strongarm-*-*
4731 Mitsubishi D30V d30v-*-*
4733 * OBSOLETE configurations
4735 Gould PowerNode, NP1 np1-*-*, pn-*-*
4737 Configurations that have been declared obsolete will be commented out,
4738 but the code will be left in place. If there is no activity to revive
4739 these configurations before the next release of GDB, the sources will
4740 be permanently REMOVED.
4744 As a compatibility experiment, GDB's source files buildsym.h and
4745 buildsym.c have been converted to pure standard C, no longer
4746 containing any K&R compatibility code. We believe that all systems in
4747 use today either come with a standard C compiler, or have a GCC port
4748 available. If this is not true, please report the affected
4749 configuration to bug-gdb@gnu.org immediately. See the README file for
4750 information about getting a standard C compiler if you don't have one
4755 GDB now uses readline 2.2.
4757 * set extension-language
4759 You can now control the mapping between filename extensions and source
4760 languages by using the `set extension-language' command. For instance,
4761 you can ask GDB to treat .c files as C++ by saying
4762 set extension-language .c c++
4763 The command `info extensions' lists all of the recognized extensions
4764 and their associated languages.
4766 * Setting processor type for PowerPC and RS/6000
4768 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4769 you can use the `set processor' command to specify what variant of the
4770 PowerPC family you are debugging. The command
4774 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4775 following PowerPC and RS6000 variants:
4777 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4778 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4780 403GC IBM PowerPC 403GC
4781 505 Motorola PowerPC 505
4782 860 Motorola PowerPC 860 or 850
4783 601 Motorola PowerPC 601
4784 602 Motorola PowerPC 602
4785 603 Motorola/IBM PowerPC 603 or 603e
4786 604 Motorola PowerPC 604 or 604e
4787 750 Motorola/IBM PowerPC 750 or 750
4789 At the moment, this command just tells GDB what to name the
4790 special-purpose processor registers. Since almost all the affected
4791 registers are inaccessible to user-level programs, this command is
4792 only useful for remote debugging in its present form.
4796 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4797 more extensive support for HP-UX. Added features include shared
4798 library support, kernel threads and hardware watchpoints for 11.00,
4799 support for HP's ANSI C and C++ compilers, and a compatibility mode
4800 for xdb and dbx commands.
4804 HP's donation includes the new concept of catchpoints, which is a
4805 generalization of the old catch command. On HP-UX, it is now possible
4806 to catch exec, fork, and vfork, as well as library loading.
4808 This means that the existing catch command has changed; its first
4809 argument now specifies the type of catch to be set up. See the
4810 output of "help catch" for a list of catchpoint types.
4812 * Debugging across forks
4814 On HP-UX, you can choose which process to debug when a fork() happens
4819 HP has donated a curses-based terminal user interface (TUI). To get
4820 it, build with --enable-tui. Although this can be enabled for any
4821 configuration, at present it only works for native HP debugging.
4823 * GDB remote protocol additions
4825 A new protocol packet 'X' that writes binary data is now available.
4826 Default behavior is to try 'X', then drop back to 'M' if the stub
4827 fails to respond. The settable variable `remotebinarydownload'
4828 allows explicit control over the use of 'X'.
4830 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4831 full 64-bit address. The command
4833 set remoteaddresssize 32
4835 can be used to revert to the old behaviour. For existing remote stubs
4836 the change should not be noticed, as the additional address information
4839 In order to assist in debugging stubs, you may use the maintenance
4840 command `packet' to send any text string to the stub. For instance,
4842 maint packet heythere
4844 sends the packet "$heythere#<checksum>". Note that it is very easy to
4845 disrupt a debugging session by sending the wrong packet at the wrong
4848 The compare-sections command allows you to compare section data on the
4849 target to what is in the executable file without uploading or
4850 downloading, by comparing CRC checksums.
4852 * Tracing can collect general expressions
4854 You may now collect general expressions at tracepoints. This requires
4855 further additions to the target-side stub; see tracepoint.c and
4856 doc/agentexpr.texi for further details.
4858 * mask-address variable for Mips
4860 For Mips targets, you may control the zeroing of the upper 32 bits of
4861 a 64-bit address by entering `set mask-address on'. This is mainly
4862 of interest to users of embedded R4xxx and R5xxx processors.
4864 * Higher serial baud rates
4866 GDB's serial code now allows you to specify baud rates 57600, 115200,
4867 230400, and 460800 baud. (Note that your host system may not be able
4868 to achieve all of these rates.)
4872 The i960 configuration now includes an initial implementation of a
4873 builtin simulator, contributed by Jim Wilson.
4876 *** Changes in GDB-4.17:
4878 * New native configurations
4880 Alpha GNU/Linux alpha*-*-linux*
4881 Unixware 2.x i[3456]86-unixware2*
4882 Irix 6.x mips*-sgi-irix6*
4883 PowerPC GNU/Linux powerpc-*-linux*
4884 PowerPC Solaris powerpcle-*-solaris*
4885 Sparc GNU/Linux sparc-*-linux*
4886 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4890 Argonaut Risc Chip (ARC) arc-*-*
4891 Hitachi H8/300S h8300*-*-*
4892 Matsushita MN10200 w/simulator mn10200-*-*
4893 Matsushita MN10300 w/simulator mn10300-*-*
4894 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4895 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4896 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4897 Mitsubishi D10V w/simulator d10v-*-*
4898 Mitsubishi M32R/D w/simulator m32r-*-elf*
4899 Tsqware Sparclet sparclet-*-*
4900 NEC V850 w/simulator v850-*-*
4902 * New debugging protocols
4904 ARM with RDI protocol arm*-*-*
4905 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4906 DDB and LSI variants of PMON protocol mips*-*-*
4907 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4908 PowerPC with SDS protocol powerpc{,le}-*-eabi
4909 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4913 All configurations can now understand and use the DWARF 2 debugging
4914 format. The choice is automatic, if the symbol file contains DWARF 2
4919 GDB now includes basic Java language support. This support is
4920 only useful with Java compilers that produce native machine code.
4922 * solib-absolute-prefix and solib-search-path
4924 For SunOS and SVR4 shared libraries, you may now set the prefix for
4925 loading absolute shared library symbol files, and the search path for
4926 locating non-absolute shared library symbol files.
4928 * Live range splitting
4930 GDB can now effectively debug code for which GCC has performed live
4931 range splitting as part of its optimization. See gdb/doc/LRS for
4932 more details on the expected format of the stabs information.
4936 GDB's support for the GNU Hurd, including thread debugging, has been
4937 updated to work with current versions of the Hurd.
4941 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4942 instruction set. ARM GDB automatically detects when Thumb
4943 instructions are in use, and adjusts disassembly and backtracing
4948 GDB's MIPS target configurations now handle the MIP16 16-bit
4953 GDB now includes support for overlays; if an executable has been
4954 linked such that multiple sections are based at the same address, GDB
4955 will decide which section to use for symbolic info. You can choose to
4956 control the decision manually, using overlay commands, or implement
4957 additional target-side support and use "overlay load-target" to bring
4958 in the overlay mapping. Do "help overlay" for more detail.
4962 The command "info symbol <address>" displays information about
4963 the symbol at the specified address.
4967 The standard remote protocol now includes an extension that allows
4968 asynchronous collection and display of trace data. This requires
4969 extensive support in the target-side debugging stub. Tracing mode
4970 includes a new interaction mode in GDB and new commands: see the
4971 file tracepoint.c for more details.
4975 Configurations for embedded MIPS now include a simulator contributed
4976 by Cygnus Solutions. The simulator supports the instruction sets
4977 of most MIPS variants.
4981 Sparc configurations may now include the ERC32 simulator contributed
4982 by the European Space Agency. The simulator is not built into
4983 Sparc targets by default; configure with --enable-sim to include it.
4987 For target configurations that may include multiple variants of a
4988 basic architecture (such as MIPS and SH), you may now set the
4989 architecture explicitly. "set arch" sets, "info arch" lists
4990 the possible architectures.
4992 *** Changes in GDB-4.16:
4994 * New native configurations
4996 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4997 M68K NetBSD m68k-*-netbsd*
4998 PowerPC AIX 4.x powerpc-*-aix*
4999 PowerPC MacOS powerpc-*-macos*
5000 PowerPC Windows NT powerpcle-*-cygwin32
5001 RS/6000 AIX 4.x rs6000-*-aix4*
5005 ARM with RDP protocol arm-*-*
5006 I960 with MON960 i960-*-coff
5007 MIPS VxWorks mips*-*-vxworks*
5008 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5009 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5011 Matra Sparclet sparclet-*-*
5015 The powerpc-eabi configuration now includes the PSIM simulator,
5016 contributed by Andrew Cagney, with assistance from Mike Meissner.
5017 PSIM is a very elaborate model of the PowerPC, including not only
5018 basic instruction set execution, but also details of execution unit
5019 performance and I/O hardware. See sim/ppc/README for more details.
5023 GDB now works with Solaris 2.5.
5025 * Windows 95/NT native
5027 GDB will now work as a native debugger on Windows 95 and Windows NT.
5028 To build it from source, you must use the "gnu-win32" environment,
5029 which uses a DLL to emulate enough of Unix to run the GNU tools.
5030 Further information, binaries, and sources are available at
5031 ftp.cygnus.com, under pub/gnu-win32.
5033 * dont-repeat command
5035 If a user-defined command includes the command `dont-repeat', then the
5036 command will not be repeated if the user just types return. This is
5037 useful if the command is time-consuming to run, so that accidental
5038 extra keystrokes don't run the same command many times.
5040 * Send break instead of ^C
5042 The standard remote protocol now includes an option to send a break
5043 rather than a ^C to the target in order to interrupt it. By default,
5044 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5046 * Remote protocol timeout
5048 The standard remote protocol includes a new variable `remotetimeout'
5049 that allows you to set the number of seconds before GDB gives up trying
5050 to read from the target. The default value is 2.
5052 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5054 By default GDB will automatically keep track of objects as they are
5055 loaded and unloaded by the dynamic linker. By using the command `set
5056 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5057 when shared library events occur, thus allowing you to set breakpoints
5058 in shared libraries which are explicitly loaded by the inferior.
5060 Note this feature does not work on hpux8. On hpux9 you must link
5061 /usr/lib/end.o into your program. This feature should work
5062 automatically on hpux10.
5064 * Irix 5.x hardware watchpoint support
5066 Irix 5 configurations now support the use of hardware watchpoints.
5068 * Mips protocol "SYN garbage limit"
5070 When debugging a Mips target using the `target mips' protocol, you
5071 may set the number of characters that GDB will ignore by setting
5072 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5073 every character. The default value is 1050.
5075 * Recording and replaying remote debug sessions
5077 If you set `remotelogfile' to the name of a file, gdb will write to it
5078 a recording of a remote debug session. This recording may then be
5079 replayed back to gdb using "gdbreplay". See gdbserver/README for
5080 details. This is useful when you have a problem with GDB while doing
5081 remote debugging; you can make a recording of the session and send it
5082 to someone else, who can then recreate the problem.
5084 * Speedups for remote debugging
5086 GDB includes speedups for downloading and stepping MIPS systems using
5087 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5088 and more efficient S-record downloading.
5090 * Memory use reductions and statistics collection
5092 GDB now uses less memory and reports statistics about memory usage.
5093 Try the `maint print statistics' command, for example.
5095 *** Changes in GDB-4.15:
5097 * Psymtabs for XCOFF
5099 The symbol reader for AIX GDB now uses partial symbol tables. This
5100 can greatly improve startup time, especially for large executables.
5102 * Remote targets use caching
5104 Remote targets now use a data cache to speed up communication with the
5105 remote side. The data cache could lead to incorrect results because
5106 it doesn't know about volatile variables, thus making it impossible to
5107 debug targets which use memory mapped I/O devices. `set remotecache
5108 off' turns the the data cache off.
5110 * Remote targets may have threads
5112 The standard remote protocol now includes support for multiple threads
5113 in the target system, using new protocol commands 'H' and 'T'. See
5114 gdb/remote.c for details.
5118 If GDB is configured with `--enable-netrom', then it will include
5119 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5120 acts as though it is a bank of ROM on the target board, but you can
5121 write into it over the network. GDB's support consists only of
5122 support for fast loading into the emulated ROM; to debug, you must use
5123 another protocol, such as standard remote protocol. The usual
5124 sequence is something like
5126 target nrom <netrom-hostname>
5128 target remote <netrom-hostname>:1235
5132 GDB now includes support for the Apple Macintosh, as a host only. It
5133 may be run as either an MPW tool or as a standalone application, and
5134 it can debug through the serial port. All the usual GDB commands are
5135 available, but to the target command, you must supply "serial" as the
5136 device type instead of "/dev/ttyXX". See mpw-README in the main
5137 directory for more information on how to build. The MPW configuration
5138 scripts */mpw-config.in support only a few targets, and only the
5139 mips-idt-ecoff target has been tested.
5143 GDB configuration now uses autoconf. This is not user-visible,
5144 but does simplify configuration and building.
5148 GDB now supports hpux10.
5150 *** Changes in GDB-4.14:
5152 * New native configurations
5154 x86 FreeBSD i[345]86-*-freebsd
5155 x86 NetBSD i[345]86-*-netbsd
5156 NS32k NetBSD ns32k-*-netbsd
5157 Sparc NetBSD sparc-*-netbsd
5161 A29K VxWorks a29k-*-vxworks
5162 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5163 CPU32 EST-300 emulator m68*-*-est*
5164 PowerPC ELF powerpc-*-elf
5167 * Alpha OSF/1 support for procfs
5169 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5170 possible to attach to running processes. As the mounting of the /proc
5171 filesystem is optional on the Alpha, GDB automatically determines
5172 the availability of /proc during startup. This can lead to problems
5173 if /proc is unmounted after GDB has been started.
5175 * Arguments to user-defined commands
5177 User commands may accept up to 10 arguments separated by whitespace.
5178 Arguments are accessed within the user command via $arg0..$arg9. A
5181 print $arg0 + $arg1 + $arg2
5183 To execute the command use:
5186 Defines the command "adder" which prints the sum of its three arguments.
5187 Note the arguments are text substitutions, so they may reference variables,
5188 use complex expressions, or even perform inferior function calls.
5190 * New `if' and `while' commands
5192 This makes it possible to write more sophisticated user-defined
5193 commands. Both commands take a single argument, which is the
5194 expression to evaluate, and must be followed by the commands to
5195 execute, one per line, if the expression is nonzero, the list being
5196 terminated by the word `end'. The `if' command list may include an
5197 `else' word, which causes the following commands to be executed only
5198 if the expression is zero.
5200 * Fortran source language mode
5202 GDB now includes partial support for Fortran 77. It will recognize
5203 Fortran programs and can evaluate a subset of Fortran expressions, but
5204 variables and functions may not be handled correctly. GDB will work
5205 with G77, but does not yet know much about symbols emitted by other
5208 * Better HPUX support
5210 Most debugging facilities now work on dynamic executables for HPPAs
5211 running hpux9 or later. You can attach to running dynamically linked
5212 processes, but by default the dynamic libraries will be read-only, so
5213 for instance you won't be able to put breakpoints in them. To change
5214 that behavior do the following before running the program:
5220 This will cause the libraries to be mapped private and read-write.
5221 To revert to the normal behavior, do this:
5227 You cannot set breakpoints or examine data in the library until after
5228 the library is loaded if the function/data symbols do not have
5231 GDB can now also read debug symbols produced by the HP C compiler on
5232 HPPAs (sorry, no C++, Fortran or 68k support).
5234 * Target byte order now dynamically selectable
5236 You can choose which byte order to use with a target system, via the
5237 commands "set endian big" and "set endian little", and you can see the
5238 current setting by using "show endian". You can also give the command
5239 "set endian auto", in which case GDB will use the byte order
5240 associated with the executable. Currently, only embedded MIPS
5241 configurations support dynamic selection of target byte order.
5243 * New DOS host serial code
5245 This version uses DPMI interrupts to handle buffered I/O, so you
5246 no longer need to run asynctsr when debugging boards connected to
5249 *** Changes in GDB-4.13:
5251 * New "complete" command
5253 This lists all the possible completions for the rest of the line, if it
5254 were to be given as a command itself. This is intended for use by emacs.
5256 * Trailing space optional in prompt
5258 "set prompt" no longer adds a space for you after the prompt you set. This
5259 allows you to set a prompt which ends in a space or one that does not.
5261 * Breakpoint hit counts
5263 "info break" now displays a count of the number of times the breakpoint
5264 has been hit. This is especially useful in conjunction with "ignore"; you
5265 can ignore a large number of breakpoint hits, look at the breakpoint info
5266 to see how many times the breakpoint was hit, then run again, ignoring one
5267 less than that number, and this will get you quickly to the last hit of
5270 * Ability to stop printing at NULL character
5272 "set print null-stop" will cause GDB to stop printing the characters of
5273 an array when the first NULL is encountered. This is useful when large
5274 arrays actually contain only short strings.
5276 * Shared library breakpoints
5278 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5279 breakpoints in shared libraries before the executable is run.
5281 * Hardware watchpoints
5283 There is a new hardware breakpoint for the watch command for sparclite
5284 targets. See gdb/sparclite/hw_breakpoint.note.
5286 Hardware watchpoints are also now supported under GNU/Linux.
5290 Annotations have been added. These are for use with graphical interfaces,
5291 and are still experimental. Currently only gdba.el uses these.
5293 * Improved Irix 5 support
5295 GDB now works properly with Irix 5.2.
5297 * Improved HPPA support
5299 GDB now works properly with the latest GCC and GAS.
5301 * New native configurations
5303 Sequent PTX4 i[34]86-sequent-ptx4
5304 HPPA running OSF/1 hppa*-*-osf*
5305 Atari TT running SVR4 m68*-*-sysv4*
5306 RS/6000 LynxOS rs6000-*-lynxos*
5310 OS/9000 i[34]86-*-os9k
5311 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5314 * Hitachi SH7000 and E7000-PC ICE support
5316 There is now support for communicating with the Hitachi E7000-PC ICE.
5317 This is available automatically when GDB is configured for the SH.
5321 As usual, a variety of small fixes and improvements, both generic
5322 and configuration-specific. See the ChangeLog for more detail.
5324 *** Changes in GDB-4.12:
5326 * Irix 5 is now supported
5330 GDB-4.12 on the HPPA has a number of changes which make it unable
5331 to debug the output from the currently released versions of GCC and
5332 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5333 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5334 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5337 *** Changes in GDB-4.11:
5339 * User visible changes:
5343 The "set remotedebug" option is now consistent between the mips remote
5344 target, remote targets using the gdb-specific protocol, UDI (AMD's
5345 debug protocol for the 29k) and the 88k bug monitor. It is now an
5346 integer specifying a debug level (normally 0 or 1, but 2 means more
5347 debugging info for the mips target).
5349 * DEC Alpha native support
5351 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5352 debug info, but GDB works fairly well with the DEC compiler and should
5353 work with a future GCC release. See the README file for a few
5354 Alpha-specific notes.
5356 * Preliminary thread implementation
5358 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5360 * LynxOS native and target support for 386
5362 This release has been hosted on LynxOS 2.2, and also can be configured
5363 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5366 * Improvements in C++ mangling/demangling.
5368 This release has much better g++ debugging, specifically in name
5369 mangling/demangling, virtual function calls, print virtual table,
5370 call methods, ...etc.
5372 *** Changes in GDB-4.10:
5374 * User visible changes:
5376 Remote debugging using the GDB-specific (`target remote') protocol now
5377 supports the `load' command. This is only useful if you have some
5378 other way of getting the stub to the target system, and you can put it
5379 somewhere in memory where it won't get clobbered by the download.
5381 Filename completion now works.
5383 When run under emacs mode, the "info line" command now causes the
5384 arrow to point to the line specified. Also, "info line" prints
5385 addresses in symbolic form (as well as hex).
5387 All vxworks based targets now support a user settable option, called
5388 vxworks-timeout. This option represents the number of seconds gdb
5389 should wait for responses to rpc's. You might want to use this if
5390 your vxworks target is, perhaps, a slow software simulator or happens
5391 to be on the far side of a thin network line.
5395 This release contains support for using a DEC alpha as a GDB host for
5396 cross debugging. Native alpha debugging is not supported yet.
5399 *** Changes in GDB-4.9:
5403 This is the first GDB release which is accompanied by a matching testsuite.
5404 The testsuite requires installation of dejagnu, which should be available
5405 via ftp from most sites that carry GNU software.
5409 'Cfront' style demangling has had its name changed to 'ARM' style, to
5410 emphasize that it was written from the specifications in the C++ Annotated
5411 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5412 disclaimers, it still generated too much confusion with users attempting to
5413 use gdb with AT&T cfront.
5417 GDB now uses a standard remote interface to a simulator library.
5418 So far, the library contains simulators for the Zilog Z8001/2, the
5419 Hitachi H8/300, H8/500 and Super-H.
5421 * New targets supported
5423 H8/300 simulator h8300-hitachi-hms or h8300hms
5424 H8/500 simulator h8500-hitachi-hms or h8500hms
5425 SH simulator sh-hitachi-hms or sh
5426 Z8000 simulator z8k-zilog-none or z8ksim
5427 IDT MIPS board over serial line mips-idt-ecoff
5429 Cross-debugging to GO32 targets is supported. It requires a custom
5430 version of the i386-stub.c module which is integrated with the
5431 GO32 memory extender.
5433 * New remote protocols
5435 MIPS remote debugging protocol.
5437 * New source languages supported
5439 This version includes preliminary support for Chill, a Pascal like language
5440 used by telecommunications companies. Chill support is also being integrated
5441 into the GNU compiler, but we don't know when it will be publically available.
5444 *** Changes in GDB-4.8:
5446 * HP Precision Architecture supported
5448 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5449 version of this support was available as a set of patches from the
5450 University of Utah. GDB does not support debugging of programs
5451 compiled with the HP compiler, because HP will not document their file
5452 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5453 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5455 Many problems in the preliminary version have been fixed.
5457 * Faster and better demangling
5459 We have improved template demangling and fixed numerous bugs in the GNU style
5460 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5461 character types (wchar_t) are now supported. Demangling of each symbol is now
5462 only done once, and is cached when the symbol table for a file is read in.
5463 This results in a small increase in memory usage for C programs, a moderate
5464 increase in memory usage for C++ programs, and a fantastic speedup in
5467 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5468 from the specifications in the Annotated Reference Manual, which AT&T's
5469 compiler does not actually implement.
5471 * G++ multiple inheritance compiler problem
5473 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5474 inheritance lattices was reworked to properly discover ambiguities. We
5475 recently found an example which causes this new algorithm to fail in a
5476 very subtle way, producing bad debug information for those classes.
5477 The file 'gcc.patch' (in this directory) can be applied to gcc to
5478 circumvent the problem. A future GCC release will contain a complete
5481 The previous G++ debug info problem (mentioned below for the gdb-4.7
5482 release) is fixed in gcc version 2.3.2.
5484 * Improved configure script
5486 The `configure' script will now attempt to guess your system type if
5487 you don't supply a host system type. The old scheme of supplying a
5488 host system triplet is preferable over using this. All the magic is
5489 done in the new `config.guess' script. Examine it for details.
5491 We have also brought our configure script much more in line with the FSF's
5492 version. It now supports the --with-xxx options. In particular,
5493 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5494 The resulting GDB will not be able to read arbitrary object file formats --
5495 only the format ``expected'' to be used on the configured target system.
5496 We hope to make this the default in a future release.
5498 * Documentation improvements
5500 There's new internal documentation on how to modify GDB, and how to
5501 produce clean changes to the code. We implore people to read it
5502 before submitting changes.
5504 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5505 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5506 `info' files are also provided. To build `info' files from scratch,
5507 you will need the latest `makeinfo' release, which will be available in
5508 a future texinfo-X.Y release.
5510 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5511 We're not sure exactly which versions have this problem, but it has
5512 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5513 or better. If that isn't possible, there is a patch in
5514 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5515 around this problem.
5519 GDB now supports array constants that can be used in expressions typed in by
5520 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5521 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5524 The new directory `gdb/sparclite' contains a program that demonstrates
5525 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5527 * New native hosts supported
5529 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5530 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5532 * New targets supported
5534 AMD 29k family via UDI a29k-amd-udi or udi29k
5536 * New file formats supported
5538 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5539 HPUX core files, and SCO 3.2v2 core files.
5543 Attaching to processes now works again; thanks for the many bug reports.
5545 We have also stomped on a bunch of core dumps caused by
5546 printf_filtered("%s") problems.
5548 We eliminated a copyright problem on the rpc and ptrace header files
5549 for VxWorks, which was discovered at the last minute during the 4.7
5550 release. You should now be able to build a VxWorks GDB.
5552 You can now interrupt gdb while an attached process is running. This
5553 will cause the attached process to stop, and give control back to GDB.
5555 We fixed problems caused by using too many file descriptors
5556 for reading symbols from object files and libraries. This was
5557 especially a problem for programs that used many (~100) shared
5560 The `step' command now only enters a subroutine if there is line number
5561 information for the subroutine. Otherwise it acts like the `next'
5562 command. Previously, `step' would enter subroutines if there was
5563 any debugging information about the routine. This avoids problems
5564 when using `cc -g1' on MIPS machines.
5566 * Internal improvements
5568 GDB's internal interfaces have been improved to make it easier to support
5569 debugging of multiple languages in the future.
5571 GDB now uses a common structure for symbol information internally.
5572 Minimal symbols (derived from linkage symbols in object files), partial
5573 symbols (from a quick scan of debug information), and full symbols
5574 contain a common subset of information, making it easier to write
5575 shared code that handles any of them.
5577 * New command line options
5579 We now accept --silent as an alias for --quiet.
5583 The memory-mapped-malloc library is now licensed under the GNU Library
5584 General Public License.
5586 *** Changes in GDB-4.7:
5588 * Host/native/target split
5590 GDB has had some major internal surgery to untangle the support for
5591 hosts and remote targets. Now, when you configure GDB for a remote
5592 target, it will no longer load in all of the support for debugging
5593 local programs on the host. When fully completed and tested, this will
5594 ensure that arbitrary host/target combinations are possible.
5596 The primary conceptual shift is to separate the non-portable code in
5597 GDB into three categories. Host specific code is required any time GDB
5598 is compiled on that host, regardless of the target. Target specific
5599 code relates to the peculiarities of the target, but can be compiled on
5600 any host. Native specific code is everything else: it can only be
5601 built when the host and target are the same system. Child process
5602 handling and core file support are two common `native' examples.
5604 GDB's use of /proc for controlling Unix child processes is now cleaner.
5605 It has been split out into a single module under the `target_ops' vector,
5606 plus two native-dependent functions for each system that uses /proc.
5608 * New hosts supported
5610 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5611 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5612 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5614 * New targets supported
5616 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5617 68030 and CPU32 m68030-*-*, m68332-*-*
5619 * New native hosts supported
5621 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5622 (386bsd is not well tested yet)
5623 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5625 * New file formats supported
5627 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5628 supports reading of `a.out.adobe' object files, which are an a.out
5629 format extended with minimal information about multiple sections.
5633 `show copying' is the same as the old `info copying'.
5634 `show warranty' is the same as `info warrantee'.
5635 These were renamed for consistency. The old commands continue to work.
5637 `info handle' is a new alias for `info signals'.
5639 You can now define pre-command hooks, which attach arbitrary command
5640 scripts to any command. The commands in the hook will be executed
5641 prior to the user's command. You can also create a hook which will be
5642 executed whenever the program stops. See gdb.texinfo.
5646 We now deal with Cfront style name mangling, and can even extract type
5647 info from mangled symbols. GDB can automatically figure out which
5648 symbol mangling style your C++ compiler uses.
5650 Calling of methods and virtual functions has been improved as well.
5654 The crash that occured when debugging Sun Ansi-C compiled binaries is
5655 fixed. This was due to mishandling of the extra N_SO stabs output
5658 We also finally got Ultrix 4.2 running in house, and fixed core file
5659 support, with help from a dozen people on the net.
5661 John M. Farrell discovered that the reason that single-stepping was so
5662 slow on all of the Mips based platforms (primarily SGI and DEC) was
5663 that we were trying to demangle and lookup a symbol used for internal
5664 purposes on every instruction that was being stepped through. Changing
5665 the name of that symbol so that it couldn't be mistaken for a C++
5666 mangled symbol sped things up a great deal.
5668 Rich Pixley sped up symbol lookups in general by getting much smarter
5669 about when C++ symbol mangling is necessary. This should make symbol
5670 completion (TAB on the command line) much faster. It's not as fast as
5671 we'd like, but it's significantly faster than gdb-4.6.
5675 A new user controllable variable 'call_scratch_address' can
5676 specify the location of a scratch area to be used when GDB
5677 calls a function in the target. This is necessary because the
5678 usual method of putting the scratch area on the stack does not work
5679 in systems that have separate instruction and data spaces.
5681 We integrated changes to support the 29k UDI (Universal Debugger
5682 Interface), but discovered at the last minute that we didn't have all
5683 of the appropriate copyright paperwork. We are working with AMD to
5684 resolve this, and hope to have it available soon.
5688 We have sped up the remote serial line protocol, especially for targets
5689 with lots of registers. It now supports a new `expedited status' ('T')
5690 message which can be used in place of the existing 'S' status message.
5691 This allows the remote stub to send only the registers that GDB
5692 needs to make a quick decision about single-stepping or conditional
5693 breakpoints, eliminating the need to fetch the entire register set for
5694 each instruction being stepped through.
5696 The GDB remote serial protocol now implements a write-through cache for
5697 registers, only re-reading the registers if the target has run.
5699 There is also a new remote serial stub for SPARC processors. You can
5700 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5701 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5702 processor with a serial port.
5706 Configure.in files have become much easier to read and modify. A new
5707 `table driven' format makes it more obvious what configurations are
5708 supported, and what files each one uses.
5712 There is a new opcodes library which will eventually contain all of the
5713 disassembly routines and opcode tables. At present, it only contains
5714 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5715 disassembler (binutils/objdump) to share these routines.
5717 The libiberty library is now copylefted under the GNU Library General
5718 Public License. This allows more liberal use, and was done so libg++
5719 can use it. This makes no difference to GDB, since the Library License
5720 grants all the rights from the General Public License.
5724 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5725 reference to the stabs symbol info used by the debugger. It is (as far
5726 as we know) the only published document on this fascinating topic. We
5727 encourage you to read it, compare it to the stabs information on your
5728 system, and send improvements on the document in general (to
5729 bug-gdb@prep.ai.mit.edu).
5731 And, of course, many bugs have been fixed.
5734 *** Changes in GDB-4.6:
5736 * Better support for C++ function names
5738 GDB now accepts as input the "demangled form" of C++ overloaded function
5739 names and member function names, and can do command completion on such names
5740 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5741 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5742 Make use of command completion, it is your friend.
5744 GDB also now accepts a variety of C++ mangled symbol formats. They are
5745 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5746 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5747 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5748 for the list of formats.
5750 * G++ symbol mangling problem
5752 Recent versions of gcc have a bug in how they emit debugging information for
5753 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5754 directory) can be applied to gcc to fix the problem. Alternatively, if you
5755 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5756 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5757 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5760 * New 'maintenance' command
5762 All of the commands related to hacking GDB internals have been moved out of
5763 the main command set, and now live behind the 'maintenance' command. This
5764 can also be abbreviated as 'mt'. The following changes were made:
5766 dump-me -> maintenance dump-me
5767 info all-breakpoints -> maintenance info breakpoints
5768 printmsyms -> maintenance print msyms
5769 printobjfiles -> maintenance print objfiles
5770 printpsyms -> maintenance print psymbols
5771 printsyms -> maintenance print symbols
5773 The following commands are new:
5775 maintenance demangle Call internal GDB demangler routine to
5776 demangle a C++ link name and prints the result.
5777 maintenance print type Print a type chain for a given symbol
5779 * Change to .gdbinit file processing
5781 We now read the $HOME/.gdbinit file before processing the argv arguments
5782 (e.g. reading symbol files or core files). This allows global parameters to
5783 be set, which will apply during the symbol reading. The ./.gdbinit is still
5784 read after argv processing.
5786 * New hosts supported
5788 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5790 GNU/Linux support i386-unknown-linux or linux
5792 We are also including code to support the HP/PA running BSD and HPUX. This
5793 is almost guaranteed not to work, as we didn't have time to test or build it
5794 for this release. We are including it so that the more adventurous (or
5795 masochistic) of you can play with it. We also had major problems with the
5796 fact that the compiler that we got from HP doesn't support the -g option.
5799 * New targets supported
5801 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5803 * More smarts about finding #include files
5805 GDB now remembers the compilation directory for all include files, and for
5806 all files from which C is generated (like yacc and lex sources). This
5807 greatly improves GDB's ability to find yacc/lex sources, and include files,
5808 especially if you are debugging your program from a directory different from
5809 the one that contains your sources.
5811 We also fixed a bug which caused difficulty with listing and setting
5812 breakpoints in include files which contain C code. (In the past, you had to
5813 try twice in order to list an include file that you hadn't looked at before.)
5815 * Interesting infernals change
5817 GDB now deals with arbitrary numbers of sections, where the symbols for each
5818 section must be relocated relative to that section's landing place in the
5819 target's address space. This work was needed to support ELF with embedded
5820 stabs used by Solaris-2.0.
5822 * Bug fixes (of course!)
5824 There have been loads of fixes for the following things:
5825 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5826 i960, stabs, DOS(GO32), procfs, etc...
5828 See the ChangeLog for details.
5830 *** Changes in GDB-4.5:
5832 * New machines supported (host and target)
5834 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5836 SGI Irix-4.x mips-sgi-irix4 or iris4
5838 * New malloc package
5840 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5841 Mmalloc is capable of handling mutiple heaps of memory. It is also
5842 capable of saving a heap to a file, and then mapping it back in later.
5843 This can be used to greatly speedup the startup of GDB by using a
5844 pre-parsed symbol table which lives in a mmalloc managed heap. For
5845 more details, please read mmalloc/mmalloc.texi.
5849 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5850 'help info proc' for details.
5852 * MIPS ecoff symbol table format
5854 The code that reads MIPS symbol table format is now supported on all hosts.
5855 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5858 * File name changes for MS-DOS
5860 Many files in the config directories have been renamed to make it easier to
5861 support GDB on MS-DOSe systems (which have very restrictive file name
5862 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5863 environment) is close to working but has some remaining problems. Note
5864 that debugging of DOS programs is not supported, due to limitations
5865 in the ``operating system'', but it can be used to host cross-debugging.
5867 * Cross byte order fixes
5869 Many fixes have been made to support cross debugging of Sparc and MIPS
5870 targets from hosts whose byte order differs.
5872 * New -mapped and -readnow options
5874 If memory-mapped files are available on your system through the 'mmap'
5875 system call, you can use the -mapped option on the `file' or
5876 `symbol-file' commands to cause GDB to write the symbols from your
5877 program into a reusable file. If the program you are debugging is
5878 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5879 Future GDB debugging sessions will notice the presence of this file,
5880 and will quickly map in symbol information from it, rather than reading
5881 the symbol table from the executable program. Using the '-mapped'
5882 option in a GDB `file' or `symbol-file' command has the same effect as
5883 starting GDB with the '-mapped' command-line option.
5885 You can cause GDB to read the entire symbol table immediately by using
5886 the '-readnow' option with any of the commands that load symbol table
5887 information (or on the GDB command line). This makes the command
5888 slower, but makes future operations faster.
5890 The -mapped and -readnow options are typically combined in order to
5891 build a `fred.syms' file that contains complete symbol information.
5892 A simple GDB invocation to do nothing but build a `.syms' file for future
5895 gdb -batch -nx -mapped -readnow programname
5897 The `.syms' file is specific to the host machine on which GDB is run.
5898 It holds an exact image of GDB's internal symbol table. It cannot be
5899 shared across multiple host platforms.
5901 * longjmp() handling
5903 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5904 siglongjmp() without losing control. This feature has not yet been ported to
5905 all systems. It currently works on many 386 platforms, all MIPS-based
5906 platforms (SGI, DECstation, etc), and Sun3/4.
5910 Preliminary work has been put in to support the new Solaris OS from Sun. At
5911 this time, it can control and debug processes, but it is not capable of
5916 As always, many many bug fixes. The major areas were with g++, and mipsread.
5917 People using the MIPS-based platforms should experience fewer mysterious
5918 crashes and trashed symbol tables.
5920 *** Changes in GDB-4.4:
5922 * New machines supported (host and target)
5924 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5926 BSD Reno on Vax vax-dec-bsd
5927 Ultrix on Vax vax-dec-ultrix
5929 * New machines supported (target)
5931 AMD 29000 embedded, using EBMON a29k-none-none
5935 GDB continues to improve its handling of C++. `References' work better.
5936 The demangler has also been improved, and now deals with symbols mangled as
5937 per the Annotated C++ Reference Guide.
5939 GDB also now handles `stabs' symbol information embedded in MIPS
5940 `ecoff' symbol tables. Since the ecoff format was not easily
5941 extensible to handle new languages such as C++, this appeared to be a
5942 good way to put C++ debugging info into MIPS binaries. This option
5943 will be supported in the GNU C compiler, version 2, when it is
5946 * New features for SVR4
5948 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5949 shared libraries. Debugging dynamically linked programs should present
5950 only minor differences from debugging statically linked programs.
5952 The `info proc' command will print out information about any process
5953 on an SVR4 system (including the one you are debugging). At the moment,
5954 it prints the address mappings of the process.
5956 If you bring up GDB on another SVR4 system, please send mail to
5957 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5959 * Better dynamic linking support in SunOS
5961 Reading symbols from shared libraries which contain debugging symbols
5962 now works properly. However, there remain issues such as automatic
5963 skipping of `transfer vector' code during function calls, which
5964 make it harder to debug code in a shared library, than to debug the
5965 same code linked statically.
5969 GDB is now using the latest `getopt' routines from the FSF. This
5970 version accepts the -- prefix for options with long names. GDB will
5971 continue to accept the old forms (-option and +option) as well.
5972 Various single letter abbreviations for options have been explicity
5973 added to the option table so that they won't get overshadowed in the
5974 future by other options that begin with the same letter.
5978 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5979 Many assorted bugs have been handled. Many more remain to be handled.
5980 See the various ChangeLog files (primarily in gdb and bfd) for details.
5983 *** Changes in GDB-4.3:
5985 * New machines supported (host and target)
5987 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5988 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5989 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5991 * Almost SCO Unix support
5993 We had hoped to support:
5994 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5995 (except for core file support), but we discovered very late in the release
5996 that it has problems with process groups that render gdb unusable. Sorry
5997 about that. I encourage people to fix it and post the fixes.
5999 * Preliminary ELF and DWARF support
6001 GDB can read ELF object files on System V Release 4, and can handle
6002 debugging records for C, in DWARF format, in ELF files. This support
6003 is preliminary. If you bring up GDB on another SVR4 system, please
6004 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6009 GDB now uses the latest `readline' library. One user-visible change
6010 is that two tabs will list possible command completions, which previously
6011 required typing M-? (meta-question mark, or ESC ?).
6015 The `stepi' bug that many of you noticed has been squashed.
6016 Many bugs in C++ have been handled. Many more remain to be handled.
6017 See the various ChangeLog files (primarily in gdb and bfd) for details.
6019 * State of the MIPS world (in case you wondered):
6021 GDB can understand the symbol tables emitted by the compilers
6022 supplied by most vendors of MIPS-based machines, including DEC. These
6023 symbol tables are in a format that essentially nobody else uses.
6025 Some versions of gcc come with an assembler post-processor called
6026 mips-tfile. This program is required if you want to do source-level
6027 debugging of gcc-compiled programs. I believe FSF does not ship
6028 mips-tfile with gcc version 1, but it will eventually come with gcc
6031 Debugging of g++ output remains a problem. g++ version 1.xx does not
6032 really support it at all. (If you're lucky, you should be able to get
6033 line numbers and stack traces to work, but no parameters or local
6034 variables.) With some work it should be possible to improve the
6037 When gcc version 2 is released, you will have somewhat better luck.
6038 However, even then you will get confusing results for inheritance and
6041 We will eventually provide full debugging of g++ output on
6042 DECstations. This will probably involve some kind of stabs-in-ecoff
6043 encapulation, but the details have not been worked out yet.
6046 *** Changes in GDB-4.2:
6048 * Improved configuration
6050 Only one copy of `configure' exists now, and it is not self-modifying.
6051 Porting BFD is simpler.
6055 The `step' and `next' commands now only stop at the first instruction
6056 of a source line. This prevents the multiple stops that used to occur
6057 in switch statements, for-loops, etc. `Step' continues to stop if a
6058 function that has debugging information is called within the line.
6062 Lots of small bugs fixed. More remain.
6064 * New host supported (not target)
6066 Intel 386 PC clone running Mach i386-none-mach
6069 *** Changes in GDB-4.1:
6071 * Multiple source language support
6073 GDB now has internal scaffolding to handle several source languages.
6074 It determines the type of each source file from its filename extension,
6075 and will switch expression parsing and number formatting to match the
6076 language of the function in the currently selected stack frame.
6077 You can also specifically set the language to be used, with
6078 `set language c' or `set language modula-2'.
6082 GDB now has preliminary support for the GNU Modula-2 compiler,
6083 currently under development at the State University of New York at
6084 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6085 continue through the fall of 1991 and into 1992.
6087 Other Modula-2 compilers are currently not supported, and attempting to
6088 debug programs compiled with them will likely result in an error as the
6089 symbol table is read. Feel free to work on it, though!
6091 There are hooks in GDB for strict type checking and range checking,
6092 in the `Modula-2 philosophy', but they do not currently work.
6096 GDB can now write to executable and core files (e.g. patch
6097 a variable's value). You must turn this switch on, specify
6098 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6099 by assigning a new value to a variable. Modifications take
6102 * Automatic SunOS shared library reading
6104 When you run your program, GDB automatically determines where its
6105 shared libraries (if any) have been loaded, and reads their symbols.
6106 The `share' command is no longer needed. This also works when
6107 examining core files.
6111 You can specify the number of lines that the `list' command shows.
6114 * New machines supported (host and target)
6116 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6117 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6118 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6120 * New hosts supported (not targets)
6122 IBM RT/PC: romp-ibm-aix or rtpc
6124 * New targets supported (not hosts)
6126 AMD 29000 embedded with COFF a29k-none-coff
6127 AMD 29000 embedded with a.out a29k-none-aout
6128 Ultracomputer remote kernel debug a29k-nyu-kern
6130 * New remote interfaces
6136 *** Changes in GDB-4.0:
6140 Wide output is wrapped at good places to make the output more readable.
6142 Gdb now supports cross-debugging from a host machine of one type to a
6143 target machine of another type. Communication with the target system
6144 is over serial lines. The ``target'' command handles connecting to the
6145 remote system; the ``load'' command will download a program into the
6146 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6147 also supports debugging of realtime processes running under VxWorks,
6148 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6149 stub on the target system.
6151 New CPUs supported include the AMD 29000 and Intel 960.
6153 GDB now reads object files and symbol tables via a ``binary file''
6154 library, which allows a single copy of GDB to debug programs of multiple
6155 object file types such as a.out and coff.
6157 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6158 refcard.dvi and refcard.ps are available to format it).
6161 * Control-Variable user interface simplified
6163 All variables that control the operation of the debugger can be set
6164 by the ``set'' command, and displayed by the ``show'' command.
6166 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6167 ``Show prompt'' produces the response:
6168 Gdb's prompt is new-gdb=>.
6170 What follows are the NEW set commands. The command ``help set'' will
6171 print a complete list of old and new set commands. ``help set FOO''
6172 will give a longer description of the variable FOO. ``show'' will show
6173 all of the variable descriptions and their current settings.
6175 confirm on/off: Enables warning questions for operations that are
6176 hard to recover from, e.g. rerunning the program while
6177 it is already running. Default is ON.
6179 editing on/off: Enables EMACS style command line editing
6180 of input. Previous lines can be recalled with
6181 control-P, the current line can be edited with control-B,
6182 you can search for commands with control-R, etc.
6185 history filename NAME: NAME is where the gdb command history
6186 will be stored. The default is .gdb_history,
6187 or the value of the environment variable
6190 history size N: The size, in commands, of the command history. The
6191 default is 256, or the value of the environment variable
6194 history save on/off: If this value is set to ON, the history file will
6195 be saved after exiting gdb. If set to OFF, the
6196 file will not be saved. The default is OFF.
6198 history expansion on/off: If this value is set to ON, then csh-like
6199 history expansion will be performed on
6200 command line input. The default is OFF.
6202 radix N: Sets the default radix for input and output. It can be set
6203 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6204 in the current radix, so "set radix 10" is always a no-op.
6206 height N: This integer value is the number of lines on a page. Default
6207 is 24, the current `stty rows'' setting, or the ``li#''
6208 setting from the termcap entry matching the environment
6211 width N: This integer value is the number of characters on a line.
6212 Default is 80, the current `stty cols'' setting, or the ``co#''
6213 setting from the termcap entry matching the environment
6216 Note: ``set screensize'' is obsolete. Use ``set height'' and
6217 ``set width'' instead.
6219 print address on/off: Print memory addresses in various command displays,
6220 such as stack traces and structure values. Gdb looks
6221 more ``symbolic'' if you turn this off; it looks more
6222 ``machine level'' with it on. Default is ON.
6224 print array on/off: Prettyprint arrays. New convenient format! Default
6227 print demangle on/off: Print C++ symbols in "source" form if on,
6230 print asm-demangle on/off: Same, for assembler level printouts
6233 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6236 * Support for Epoch Environment.
6238 The epoch environment is a version of Emacs v18 with windowing. One
6239 new command, ``inspect'', is identical to ``print'', except that if you
6240 are running in the epoch environment, the value is printed in its own
6244 * Support for Shared Libraries
6246 GDB can now debug programs and core files that use SunOS shared libraries.
6247 Symbols from a shared library cannot be referenced
6248 before the shared library has been linked with the program (this
6249 happens after you type ``run'' and before the function main() is entered).
6250 At any time after this linking (including when examining core files
6251 from dynamically linked programs), gdb reads the symbols from each
6252 shared library when you type the ``sharedlibrary'' command.
6253 It can be abbreviated ``share''.
6255 sharedlibrary REGEXP: Load shared object library symbols for files
6256 matching a unix regular expression. No argument
6257 indicates to load symbols for all shared libraries.
6259 info sharedlibrary: Status of loaded shared libraries.
6264 A watchpoint stops execution of a program whenever the value of an
6265 expression changes. Checking for this slows down execution
6266 tremendously whenever you are in the scope of the expression, but is
6267 quite useful for catching tough ``bit-spreader'' or pointer misuse
6268 problems. Some machines such as the 386 have hardware for doing this
6269 more quickly, and future versions of gdb will use this hardware.
6271 watch EXP: Set a watchpoint (breakpoint) for an expression.
6273 info watchpoints: Information about your watchpoints.
6275 delete N: Deletes watchpoint number N (same as breakpoints).
6276 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6277 enable N: Re-enables watchpoint number N (same as breakpoints).
6280 * C++ multiple inheritance
6282 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6285 * C++ exception handling
6287 Gdb now supports limited C++ exception handling. Besides the existing
6288 ability to breakpoint on an exception handler, gdb can breakpoint on
6289 the raising of an exception (before the stack is peeled back to the
6292 catch FOO: If there is a FOO exception handler in the dynamic scope,
6293 set a breakpoint to catch exceptions which may be raised there.
6294 Multiple exceptions (``catch foo bar baz'') may be caught.
6296 info catch: Lists all exceptions which may be caught in the
6297 current stack frame.
6300 * Minor command changes
6302 The command ``call func (arg, arg, ...)'' now acts like the print
6303 command, except it does not print or save a value if the function's result
6304 is void. This is similar to dbx usage.
6306 The ``up'' and ``down'' commands now always print the frame they end up
6307 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6308 frames without printing.
6310 * New directory command
6312 'dir' now adds directories to the FRONT of the source search path.
6313 The path starts off empty. Source files that contain debug information
6314 about the directory in which they were compiled can be found even
6315 with an empty path; Sun CC and GCC include this information. If GDB can't
6316 find your source file in the current directory, type "dir .".
6318 * Configuring GDB for compilation
6320 For normal use, type ``./configure host''. See README or gdb.texinfo
6323 GDB now handles cross debugging. If you are remotely debugging between
6324 two different machines, type ``./configure host -target=targ''.
6325 Host is the machine where GDB will run; targ is the machine
6326 where the program that you are debugging will run.