1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.10
6 * Support for tracepoints on aarch64-linux was added in GDBserver.
8 * The 'record instruction-history' command now indicates speculative execution
9 when using the Intel(R) Processor Trace recording format.
11 * GDB now allows users to specify explicit locations, bypassing
12 the linespec parser. This feature is also available to GDB/MI
17 maint set target-non-stop (on|off|auto)
18 maint show target-non-stop
19 Control whether GDB targets always operate in non-stop mode even if
20 "set non-stop" is "off". The default is "auto", meaning non-stop
21 mode is enabled if supported by the target.
23 *** Changes in GDB 7.10
25 * Support for process record-replay and reverse debugging on aarch64*-linux*
26 targets has been added. GDB now supports recording of A64 instruction set
27 including advance SIMD instructions.
29 * Support for Sun's version of the "stabs" debug file format has been removed.
31 * GDB now honors the content of the file /proc/PID/coredump_filter
32 (PID is the process ID) on GNU/Linux systems. This file can be used
33 to specify the types of memory mappings that will be included in a
34 corefile. For more information, please refer to the manual page of
35 "core(5)". GDB also has a new command: "set use-coredump-filter
36 on|off". It allows to set whether GDB will read the content of the
37 /proc/PID/coredump_filter file when generating a corefile.
39 * The "info os" command on GNU/Linux can now display information on
41 "info os cpus" Listing of all cpus/cores on the system
43 * GDB has two new commands: "set serial parity odd|even|none" and
44 "show serial parity". These allows to set or show parity for the
47 * The "info source" command now displays the producer string if it was
48 present in the debug info. This typically includes the compiler version
49 and may include things like its command line arguments.
51 * The "info dll", an alias of the "info sharedlibrary" command,
52 is now available on all platforms.
54 * Directory names supplied to the "set sysroot" commands may be
55 prefixed with "target:" to tell GDB to access shared libraries from
56 the target system, be it local or remote. This replaces the prefix
57 "remote:". The default sysroot has been changed from "" to
58 "target:". "remote:" is automatically converted to "target:" for
59 backward compatibility.
61 * The system root specified by "set sysroot" will be prepended to the
62 filename of the main executable (if reported to GDB as absolute by
63 the operating system) when starting processes remotely, and when
64 attaching to already-running local or remote processes.
66 * GDB now supports automatic location and retrieval of executable
67 files from remote targets. Remote debugging can now be initiated
68 using only a "target remote" or "target extended-remote" command
69 (no "set sysroot" or "file" commands are required). See "New remote
72 * The "dump" command now supports verilog hex format.
74 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
76 * On GNU/Linux, GDB and gdbserver are now able to access executable
77 and shared library files without a "set sysroot" command when
78 attaching to processes running in different mount namespaces from
79 the debugger. This makes it possible to attach to processes in
80 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
81 See "New remote packets" below.
83 * The "tui reg" command now provides completion for all of the
84 available register groups, including target specific groups.
86 * The HISTSIZE environment variable is no longer read when determining
87 the size of GDB's command history. GDB now instead reads the dedicated
88 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
89 disables truncation of command history. Non-numeric values of GDBHISTSIZE
94 ** Memory ports can now be unbuffered.
98 ** gdb.Objfile objects have a new attribute "username",
99 which is the name of the objfile as specified by the user,
100 without, for example, resolving symlinks.
101 ** You can now write frame unwinders in Python.
102 ** gdb.Type objects have a new method "optimized_out",
103 returning optimized out gdb.Value instance of this type.
104 ** gdb.Value objects have new methods "reference_value" and
105 "const_value" which return a reference to the value and a
106 "const" version of the value respectively.
110 maint print symbol-cache
111 Print the contents of the symbol cache.
113 maint print symbol-cache-statistics
114 Print statistics of symbol cache usage.
116 maint flush-symbol-cache
117 Flush the contents of the symbol cache.
119 maint set target-non-stop (on|off|auto)
120 maint show target-non-stop
121 Control whether GDB targets always operate in non-stop mode even if
122 "set non-stop" is "off". The default is "auto", meaning non-stop
123 mode is enabled if supported by the target.
127 Start branch trace recording using Branch Trace Store (BTS) format.
130 Evaluate expression by using the compiler and print result.
134 Explicit commands for enabling and disabling tui mode.
137 set mpx bound on i386 and amd64
138 Support for bound table investigation on Intel(R) MPX enabled applications.
142 Start branch trace recording using Intel(R) Processor Trace format.
145 Print information about branch tracing internals.
147 maint btrace packet-history
148 Print the raw branch tracing data.
150 maint btrace clear-packet-history
151 Discard the stored raw branch tracing data.
154 Discard all branch tracing data. It will be fetched and processed
155 anew by the next "record" command.
160 Renamed from "set debug dwarf2-die".
162 Renamed from "show debug dwarf2-die".
165 Renamed from "set debug dwarf2-read".
166 show debug dwarf-read
167 Renamed from "show debug dwarf2-read".
169 maint set dwarf always-disassemble
170 Renamed from "maint set dwarf2 always-disassemble".
171 maint show dwarf always-disassemble
172 Renamed from "maint show dwarf2 always-disassemble".
174 maint set dwarf max-cache-age
175 Renamed from "maint set dwarf2 max-cache-age".
176 maint show dwarf max-cache-age
177 Renamed from "maint show dwarf2 max-cache-age".
180 show debug dwarf-line
181 Control display of debugging info regarding DWARF line processing.
185 Set the maximum number of candidates to be considered during
186 completion. The default value is 200. This limit allows GDB
187 to avoid generating large completion lists, the computation of
188 which can cause the debugger to become temporarily unresponsive.
190 set history remove-duplicates
191 show history remove-duplicates
192 Control the removal of duplicate history entries.
194 maint set symbol-cache-size
195 maint show symbol-cache-size
196 Control the size of the symbol cache.
198 set|show record btrace bts buffer-size
199 Set and show the size of the ring buffer used for branch tracing in
201 The obtained size may differ from the requested size. Use "info
202 record" to see the obtained buffer size.
204 set debug linux-namespaces
205 show debug linux-namespaces
206 Control display of debugging info regarding Linux namespaces.
208 set|show record btrace pt buffer-size
209 Set and show the size of the ring buffer used for branch tracing in
210 Intel(R) Processor Trace format.
211 The obtained size may differ from the requested size. Use "info
212 record" to see the obtained buffer size.
214 maint set|show btrace pt skip-pad
215 Set and show whether PAD packets are skipped when computing the
218 * The command 'thread apply all' can now support new option '-ascending'
219 to call its specified command for all threads in ascending order.
221 * Python/Guile scripting
223 ** GDB now supports auto-loading of Python/Guile scripts contained in the
224 special section named `.debug_gdb_scripts'.
228 qXfer:btrace-conf:read
229 Return the branch trace configuration for the current thread.
231 Qbtrace-conf:bts:size
232 Set the requested ring buffer size for branch tracing in BTS format.
235 Enable Intel(R) Procesor Trace-based branch tracing for the current
236 process. The remote stub reports support for this packet to GDB's
240 Set the requested ring buffer size for branch tracing in Intel(R) Processor
244 Indicates a memory breakpoint instruction was executed, irrespective
245 of whether it was GDB that planted the breakpoint or the breakpoint
246 is hardcoded in the program. This is required for correct non-stop
250 Indicates the target stopped for a hardware breakpoint. This is
251 required for correct non-stop mode operation.
254 Return information about files on the remote system.
257 Return the full absolute name of the file that was executed to
258 create a process running on the remote system.
261 Select the filesystem on which vFile: operations with filename
262 arguments will operate. This is required for GDB to be able to
263 access files on remote targets where the remote stub does not
264 share a common filesystem with the inferior(s).
267 Indicates that a fork system call was executed.
270 Indicates that a vfork system call was executed.
272 vforkdone stop reason
273 Indicates that a vfork child of the specified process has executed
274 an exec or exit, allowing the vfork parent to resume execution.
276 fork-events and vfork-events features in qSupported
277 The qSupported packet allows GDB to request support for fork and
278 vfork events using new 'gdbfeatures' fork-events and vfork-events,
279 and the qSupported response can contain the corresponding
280 'stubfeatures'. Set and show commands can be used to display
281 whether these features are enabled.
283 * Extended-remote fork events
285 ** GDB now has support for fork events on extended-remote Linux
286 targets. For targets with Linux kernels 2.5.60 and later, this
287 enables follow-fork-mode and detach-on-fork for both fork and
288 vfork, as well as fork and vfork catchpoints.
290 * The info record command now shows the recording format and the
291 branch tracing configuration for the current thread when using
292 the btrace record target.
293 For the BTS format, it shows the ring buffer size.
295 * GDB now has support for DTrace USDT (Userland Static Defined
296 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
298 * GDB now supports access to vector registers on S/390 GNU/Linux
301 * Removed command line options
303 -xdb HP-UX XDB compatibility mode.
305 * Removed targets and native configurations
307 HP/PA running HP-UX hppa*-*-hpux*
308 Itanium running HP-UX ia64-*-hpux*
310 * New configure options
313 This configure option allows the user to build GDB with support for
314 Intel(R) Processor Trace (default: auto). This requires libipt.
316 --with-libipt-prefix=PATH
317 Specify the path to the version of libipt that GDB should use.
318 $PATH/include should contain the intel-pt.h header and
319 $PATH/lib should contain the libipt.so library.
321 *** Changes in GDB 7.9.1
325 ** Xmethods can now specify a result type.
327 *** Changes in GDB 7.9
329 * GDB now supports hardware watchpoints on x86 GNU Hurd.
333 ** You can now access frame registers from Python scripts.
334 ** New attribute 'producer' for gdb.Symtab objects.
335 ** gdb.Objfile objects have a new attribute "progspace",
336 which is the gdb.Progspace object of the containing program space.
337 ** gdb.Objfile objects have a new attribute "owner".
338 ** gdb.Objfile objects have a new attribute "build_id",
339 which is the build ID generated when the file was built.
340 ** gdb.Objfile objects have a new method "add_separate_debug_file".
341 ** A new event "gdb.clear_objfiles" has been added, triggered when
342 selecting a new file to debug.
343 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
344 ** New function gdb.lookup_objfile.
346 New events which are triggered when GDB modifies the state of the
349 ** gdb.events.inferior_call_pre: Function call is about to be made.
350 ** gdb.events.inferior_call_post: Function call has just been made.
351 ** gdb.events.memory_changed: A memory location has been altered.
352 ** gdb.events.register_changed: A register has been altered.
354 * New Python-based convenience functions:
356 ** $_caller_is(name [, number_of_frames])
357 ** $_caller_matches(regexp [, number_of_frames])
358 ** $_any_caller_is(name [, number_of_frames])
359 ** $_any_caller_matches(regexp [, number_of_frames])
361 * GDB now supports the compilation and injection of source code into
362 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
363 to compile the source code to object code, and if successful, inject
364 and execute that code within the current context of the inferior.
365 Currently the C language is supported. The commands used to
366 interface with this new feature are:
368 compile code [-raw|-r] [--] [source code]
369 compile file [-raw|-r] filename
373 demangle [-l language] [--] name
374 Demangle "name" in the specified language, or the current language
375 if elided. This command is renamed from the "maint demangle" command.
376 The latter is kept as a no-op to avoid "maint demangle" being interpreted
377 as "maint demangler-warning".
379 queue-signal signal-name-or-number
380 Queue a signal to be delivered to the thread when it is resumed.
382 add-auto-load-scripts-directory directory
383 Add entries to the list of directories from which to load auto-loaded
386 maint print user-registers
387 List all currently available "user" registers.
389 compile code [-r|-raw] [--] [source code]
390 Compile, inject, and execute in the inferior the executable object
391 code produced by compiling the provided source code.
393 compile file [-r|-raw] filename
394 Compile and inject into the inferior the executable object code
395 produced by compiling the source code stored in the filename
398 * On resume, GDB now always passes the signal the program had stopped
399 for to the thread the signal was sent to, even if the user changed
400 threads before resuming. Previously GDB would often (but not
401 always) deliver the signal to the thread that happens to be current
404 * Conversely, the "signal" command now consistently delivers the
405 requested signal to the current thread. GDB now asks for
406 confirmation if the program had stopped for a signal and the user
407 switched threads meanwhile.
409 * "breakpoint always-inserted" modes "off" and "auto" merged.
411 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
412 won't remove breakpoints from the target until all threads stop,
413 even in non-stop mode. The "auto" mode has been removed, and "off"
414 is now the default mode.
418 set debug symbol-lookup
419 show debug symbol-lookup
420 Control display of debugging info regarding symbol lookup.
424 ** The -list-thread-groups command outputs an exit-code field for
425 inferiors that have exited.
429 MIPS SDE mips*-sde*-elf*
433 Support for these obsolete configurations has been removed.
435 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
436 SGI Irix-5.x mips-*-irix5*
437 SGI Irix-6.x mips-*-irix6*
438 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
439 VAX running Ultrix vax-*-ultrix*
441 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
442 and "assf"), have been removed. Use the "sharedlibrary" command, or
443 its alias "share", instead.
445 *** Changes in GDB 7.8
447 * New command line options
450 This is an alias for the --data-directory option.
452 * GDB supports printing and modifying of variable length automatic arrays
453 as specified in ISO C99.
455 * The ARM simulator now supports instruction level tracing
456 with or without disassembly.
460 GDB now has support for scripting using Guile. Whether this is
461 available is determined at configure time.
462 Guile version 2.0 or greater is required.
463 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
465 * New commands (for set/show, see "New options" below)
469 Invoke CODE by passing it to the Guile interpreter.
473 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
475 info auto-load guile-scripts [regexp]
476 Print the list of automatically loaded Guile scripts.
478 * The source command is now capable of sourcing Guile scripts.
479 This feature is dependent on the debugger being built with Guile support.
483 set print symbol-loading (off|brief|full)
484 show print symbol-loading
485 Control whether to print informational messages when loading symbol
486 information for a file. The default is "full", but when debugging
487 programs with large numbers of shared libraries the amount of output
490 set guile print-stack (none|message|full)
491 show guile print-stack
492 Show a stack trace when an error is encountered in a Guile script.
494 set auto-load guile-scripts (on|off)
495 show auto-load guile-scripts
496 Control auto-loading of Guile script files.
498 maint ada set ignore-descriptive-types (on|off)
499 maint ada show ignore-descriptive-types
500 Control whether the debugger should ignore descriptive types in Ada
501 programs. The default is not to ignore the descriptive types. See
502 the user manual for more details on descriptive types and the intended
503 usage of this option.
505 set auto-connect-native-target
507 Control whether GDB is allowed to automatically connect to the
508 native target for the run, attach, etc. commands when not connected
509 to any target yet. See also "target native" below.
511 set record btrace replay-memory-access (read-only|read-write)
512 show record btrace replay-memory-access
513 Control what memory accesses are allowed during replay.
515 maint set target-async (on|off)
516 maint show target-async
517 This controls whether GDB targets operate in synchronous or
518 asynchronous mode. Normally the default is asynchronous, if it is
519 available; but this can be changed to more easily debug problems
520 occurring only in synchronous mode.
522 set mi-async (on|off)
524 Control whether MI asynchronous mode is preferred. This supersedes
525 "set target-async" of previous GDB versions.
527 * "set target-async" is deprecated as a CLI option and is now an alias
528 for "set mi-async" (only puts MI into async mode).
530 * Background execution commands (e.g., "c&", "s&", etc.) are now
531 possible ``out of the box'' if the target supports them. Previously
532 the user would need to explicitly enable the possibility with the
533 "set target-async on" command.
535 * New features in the GDB remote stub, GDBserver
537 ** New option --debug-format=option1[,option2,...] allows one to add
538 additional text to each output. At present only timestamps
539 are supported: --debug-format=timestamps.
540 Timestamps can also be turned on with the
541 "monitor set debug-format timestamps" command from GDB.
543 * The 'record instruction-history' command now starts counting instructions
544 at one. This also affects the instruction ranges reported by the
545 'record function-call-history' command when given the /i modifier.
547 * The command 'record function-call-history' supports a new modifier '/c' to
548 indent the function names based on their call stack depth.
549 The fields for the '/i' and '/l' modifier have been reordered.
550 The source line range is now prefixed with 'at'.
551 The instruction range is now prefixed with 'inst'.
552 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
553 "record instruction-history" and "list" commands.
555 * The ranges given as arguments to the 'record function-call-history' and
556 'record instruction-history' commands are now inclusive.
558 * The btrace record target now supports the 'record goto' command.
559 For locations inside the execution trace, the back trace is computed
560 based on the information stored in the execution trace.
562 * The btrace record target supports limited reverse execution and replay.
563 The target does not record data and therefore does not allow reading
566 * The "catch syscall" command now works on s390*-linux* targets.
568 * The "compare-sections" command is no longer specific to target
569 remote. It now works with all targets.
571 * All native targets are now consistently called "native".
572 Consequently, the "target child", "target GNU", "target djgpp",
573 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
574 commands have been replaced with "target native". The QNX/NTO port
575 leaves the "procfs" target in place and adds a "native" target for
576 consistency with other ports. The impact on users should be minimal
577 as these commands previously either throwed an error, or were
578 no-ops. The target's name is visible in the output of the following
579 commands: "help target", "info target", "info files", "maint print
582 * The "target native" command now connects to the native target. This
583 can be used to launch native programs even when "set
584 auto-connect-native-target" is set to off.
586 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.
588 * Support for Intel(R) AVX-512 registers on GNU/Linux.
589 Support displaying and modifying Intel(R) AVX-512 registers
590 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
594 qXfer:btrace:read's annex
595 The qXfer:btrace:read packet supports a new annex 'delta' to read
596 branch trace incrementally.
600 ** Valid Python operations on gdb.Value objects representing
601 structs/classes invoke the corresponding overloaded operators if
603 ** New `Xmethods' feature in the Python API. Xmethods are
604 additional methods or replacements for existing methods of a C++
605 class. This feature is useful for those cases where a method
606 defined in C++ source code could be inlined or optimized out by
607 the compiler, making it unavailable to GDB.
610 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
612 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
613 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
614 its alias "share", instead.
616 * The commands "set remotebaud" and "show remotebaud" are no longer
617 supported. Use "set serial baud" and "show serial baud" (respectively)
622 ** A new option "-gdb-set mi-async" replaces "-gdb-set
623 target-async". The latter is left as a deprecated alias of the
624 former for backward compatibility. If the target supports it,
625 CLI background execution commands are now always possible by
626 default, independently of whether the frontend stated a
627 preference for asynchronous execution with "-gdb-set mi-async".
628 Previously "-gdb-set target-async off" affected both MI execution
629 commands and CLI execution commands.
631 *** Changes in GDB 7.7
633 * Improved support for process record-replay and reverse debugging on
634 arm*-linux* targets. Support for thumb32 and syscall instruction
635 recording has been added.
637 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
639 * GDB now supports Fission DWP file format version 2.
640 http://gcc.gnu.org/wiki/DebugFission
642 * New convenience function "$_isvoid", to check whether an expression
643 is void. A void expression is an expression where the type of the
644 result is "void". For example, some convenience variables may be
645 "void" when evaluated (e.g., "$_exitcode" before the execution of
646 the program being debugged; or an undefined convenience variable).
647 Another example, when calling a function whose return type is
650 * The "maintenance print objfiles" command now takes an optional regexp.
652 * The "catch syscall" command now works on arm*-linux* targets.
654 * GDB now consistently shows "<not saved>" when printing values of
655 registers the debug info indicates have not been saved in the frame
656 and there's nowhere to retrieve them from
657 (callee-saved/call-clobbered registers):
662 (gdb) info registers rax
665 Before, the former would print "<optimized out>", and the latter
666 "*value not available*".
668 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
673 ** Frame filters and frame decorators have been added.
674 ** Temporary breakpoints are now supported.
675 ** Line tables representation has been added.
676 ** New attribute 'parent_type' for gdb.Field objects.
677 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
678 ** New attribute 'name' for gdb.Type objects.
682 Nios II ELF nios2*-*-elf
683 Nios II GNU/Linux nios2*-*-linux
684 Texas Instruments MSP430 msp430*-*-elf
686 * Removed native configurations
688 Support for these a.out NetBSD and OpenBSD obsolete configurations has
689 been removed. ELF variants of these configurations are kept supported.
691 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
692 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
693 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
694 i[34567]86-*-openbsd3.[0-3]
695 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
696 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
697 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
701 Like "catch throw", but catches a re-thrown exception.
703 Renamed from old "maint check-symtabs".
705 Perform consistency checks on symtabs.
707 Expand symtabs matching an optional regexp.
710 Display the details of GDB configure-time options.
712 maint set|show per-command
713 maint set|show per-command space
714 maint set|show per-command time
715 maint set|show per-command symtab
716 Enable display of per-command gdb resource usage.
718 remove-symbol-file FILENAME
719 remove-symbol-file -a ADDRESS
720 Remove a symbol file added via add-symbol-file. The file to remove
721 can be identified by its filename or by an address that lies within
722 the boundaries of this symbol file in memory.
725 info exceptions REGEXP
726 Display the list of Ada exceptions defined in the program being
727 debugged. If provided, only the exceptions whose names match REGEXP
732 set debug symfile off|on
734 Control display of debugging info regarding reading symbol files and
735 symbol tables within those files
737 set print raw frame-arguments
738 show print raw frame-arguments
739 Set/show whether to print frame arguments in raw mode,
740 disregarding any defined pretty-printers.
742 set remote trace-status-packet
743 show remote trace-status-packet
744 Set/show the use of remote protocol qTStatus packet.
748 Control display of debugging messages related to Nios II targets.
752 Control whether target-assisted range stepping is enabled.
754 set startup-with-shell
755 show startup-with-shell
756 Specifies whether Unix child processes are started via a shell or
761 Use the target memory cache for accesses to the code segment. This
762 improves performance of remote debugging (particularly disassembly).
764 * You can now use a literal value 'unlimited' for options that
765 interpret 0 or -1 as meaning "unlimited". E.g., "set
766 trace-buffer-size unlimited" is now an alias for "set
767 trace-buffer-size -1" and "set height unlimited" is now an alias for
770 * The "set debug symtab-create" debugging option of GDB has been changed to
771 accept a verbosity level. 0 means "off", 1 provides basic debugging
772 output, and values of 2 or greater provides more verbose output.
774 * New command-line options
776 Display the details of GDB configure-time options.
778 * The command 'tsave' can now support new option '-ctf' to save trace
779 buffer in Common Trace Format.
781 * Newly installed $prefix/bin/gcore acts as a shell interface for the
784 * GDB now implements the the C++ 'typeid' operator.
786 * The new convenience variable $_exception holds the exception being
787 thrown or caught at an exception-related catchpoint.
789 * The exception-related catchpoints, like "catch throw", now accept a
790 regular expression which can be used to filter exceptions by type.
792 * The new convenience variable $_exitsignal is automatically set to
793 the terminating signal number when the program being debugged dies
794 due to an uncaught signal.
798 ** All MI commands now accept an optional "--language" option.
799 Support for this feature can be verified by using the "-list-features"
800 command, which should contain "language-option".
802 ** The new command -info-gdb-mi-command allows the user to determine
803 whether a GDB/MI command is supported or not.
805 ** The "^error" result record returned when trying to execute an undefined
806 GDB/MI command now provides a variable named "code" whose content is the
807 "undefined-command" error code. Support for this feature can be verified
808 by using the "-list-features" command, which should contain
809 "undefined-command-error-code".
811 ** The -trace-save MI command can optionally save trace buffer in Common
814 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
816 ** The command -data-list-register-values now accepts an optional
817 "--skip-unavailable" option. When used, only the available registers
820 ** The new command -trace-frame-collected dumps collected variables,
821 computed expressions, tvars, memory and registers in a traceframe.
823 ** The commands -stack-list-locals, -stack-list-arguments and
824 -stack-list-variables now accept an option "--skip-unavailable".
825 When used, only the available locals or arguments are displayed.
827 ** The -exec-run command now accepts an optional "--start" option.
828 When used, the command follows the same semantics as the "start"
829 command, stopping the program's execution at the start of its
830 main subprogram. Support for this feature can be verified using
831 the "-list-features" command, which should contain
832 "exec-run-start-option".
834 ** The new commands -catch-assert and -catch-exceptions insert
835 catchpoints stopping the program when Ada exceptions are raised.
837 ** The new command -info-ada-exceptions provides the equivalent of
838 the new "info exceptions" command.
840 * New system-wide configuration scripts
841 A GDB installation now provides scripts suitable for use as system-wide
842 configuration scripts for the following systems:
846 * GDB now supports target-assigned range stepping with remote targets.
847 This improves the performance of stepping source lines by reducing
848 the number of control packets from/to GDB. See "New remote packets"
851 * GDB now understands the element 'tvar' in the XML traceframe info.
852 It has the id of the collected trace state variables.
854 * On S/390 targets that provide the transactional-execution feature,
855 the program interruption transaction diagnostic block (TDB) is now
856 represented as a number of additional "registers" in GDB.
862 The vCont packet supports a new 'r' action, that tells the remote
863 stub to step through an address range itself, without GDB
864 involvemement at each single-step.
866 qXfer:libraries-svr4:read's annex
867 The previously unused annex of the qXfer:libraries-svr4:read packet
868 is now used to support passing an argument list. The remote stub
869 reports support for this argument list to GDB's qSupported query.
870 The defined arguments are "start" and "prev", used to reduce work
871 necessary for library list updating, resulting in significant
874 * New features in the GDB remote stub, GDBserver
876 ** GDBserver now supports target-assisted range stepping. Currently
877 enabled on x86/x86_64 GNU/Linux targets.
879 ** GDBserver now adds element 'tvar' in the XML in the reply to
880 'qXfer:traceframe-info:read'. It has the id of the collected
881 trace state variables.
883 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
886 * New 'z' formatter for printing and examining memory, this displays the
887 value as hexadecimal zero padded on the left to the size of the type.
889 * GDB can now use Windows x64 unwinding data.
891 * The "set remotebaud" command has been replaced by "set serial baud".
892 Similarly, "show remotebaud" has been replaced by "show serial baud".
893 The "set remotebaud" and "show remotebaud" commands are still available
894 to provide backward compatibility with older versions of GDB.
896 *** Changes in GDB 7.6
898 * Target record has been renamed to record-full.
899 Record/replay is now enabled with the "record full" command.
900 This also affects settings that are associated with full record/replay
901 that have been moved from "set/show record" to "set/show record full":
903 set|show record full insn-number-max
904 set|show record full stop-at-limit
905 set|show record full memory-query
907 * A new record target "record-btrace" has been added. The new target
908 uses hardware support to record the control-flow of a process. It
909 does not support replaying the execution, but it implements the
910 below new commands for investigating the recorded execution log.
911 This new recording method can be enabled using:
915 The "record-btrace" target is only available on Intel Atom processors
916 and requires a Linux kernel 2.6.32 or later.
918 * Two new commands have been added for record/replay to give information
919 about the recorded execution without having to replay the execution.
920 The commands are only supported by "record btrace".
922 record instruction-history prints the execution history at
923 instruction granularity
925 record function-call-history prints the execution history at
928 * New native configurations
930 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
931 FreeBSD/powerpc powerpc*-*-freebsd
932 x86_64/Cygwin x86_64-*-cygwin*
933 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
937 ARM AArch64 aarch64*-*-elf
938 ARM AArch64 GNU/Linux aarch64*-*-linux
939 Lynx 178 PowerPC powerpc-*-lynx*178
940 x86_64/Cygwin x86_64-*-cygwin*
941 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
943 * If the configured location of system.gdbinit file (as given by the
944 --with-system-gdbinit option at configure time) is in the
945 data-directory (as specified by --with-gdb-datadir at configure
946 time) or in one of its subdirectories, then GDB will look for the
947 system-wide init file in the directory specified by the
948 --data-directory command-line option.
950 * New command line options:
952 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
953 other initialization files, unlike -nx which disables all of them.
955 * Removed command line options
957 -epoch This was used by the gdb mode in Epoch, an ancient fork of
960 * The 'ptype' and 'whatis' commands now accept an argument to control
963 * 'info proc' now works on some core files.
967 ** Vectors can be created with gdb.Type.vector.
969 ** Python's atexit.register now works in GDB.
971 ** Types can be pretty-printed via a Python API.
973 ** Python 3 is now supported (in addition to Python 2.4 or later)
975 ** New class gdb.Architecture exposes GDB's internal representation
976 of architecture in the Python API.
978 ** New method Frame.architecture returns the gdb.Architecture object
979 corresponding to the frame's architecture.
981 * New Python-based convenience functions:
983 ** $_memeq(buf1, buf2, length)
984 ** $_streq(str1, str2)
986 ** $_regex(str, regex)
988 * The 'cd' command now defaults to using '~' (the home directory) if not
991 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
992 default for GCC since November 2000.
994 * The command 'forward-search' can now be abbreviated as 'fo'.
996 * The command 'info tracepoints' can now display 'installed on target'
997 or 'not installed on target' for each non-pending location of tracepoint.
999 * New configure options
1001 --enable-libmcheck/--disable-libmcheck
1002 By default, development versions are built with -lmcheck on hosts
1003 that support it, in order to help track memory corruption issues.
1004 Release versions, on the other hand, are built without -lmcheck
1005 by default. The --enable-libmcheck/--disable-libmcheck configure
1006 options allow the user to override that default.
1007 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1008 This configure option allows the user to build GDB with
1009 libbabeltrace using which GDB can read Common Trace Format data.
1011 * New commands (for set/show, see "New options" below)
1014 Catch signals. This is similar to "handle", but allows commands and
1015 conditions to be attached.
1018 List the BFDs known to GDB.
1020 python-interactive [command]
1022 Start a Python interactive prompt, or evaluate the optional command
1023 and print the result of expressions.
1026 "py" is a new alias for "python".
1028 enable type-printer [name]...
1029 disable type-printer [name]...
1030 Enable or disable type printers.
1034 ** For the Renesas Super-H architecture, the "regs" command has been removed
1035 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1040 set print type methods (on|off)
1041 show print type methods
1042 Control whether method declarations are displayed by "ptype".
1043 The default is to show them.
1045 set print type typedefs (on|off)
1046 show print type typedefs
1047 Control whether typedef definitions are displayed by "ptype".
1048 The default is to show them.
1050 set filename-display basename|relative|absolute
1051 show filename-display
1052 Control the way in which filenames is displayed.
1053 The default is "relative", which preserves previous behavior.
1055 set trace-buffer-size
1056 show trace-buffer-size
1057 Request target to change the size of trace buffer.
1059 set remote trace-buffer-size-packet auto|on|off
1060 show remote trace-buffer-size-packet
1061 Control the use of the remote protocol `QTBuffer:size' packet.
1065 Control display of debugging messages related to ARM AArch64.
1068 set debug coff-pe-read
1069 show debug coff-pe-read
1070 Control display of debugging messages related to reading of COFF/PE
1075 Control display of debugging messages related to Mach-O symbols
1078 set debug notification
1079 show debug notification
1080 Control display of debugging info for async remote notification.
1084 ** Command parameter changes are now notified using new async record
1085 "=cmd-param-changed".
1086 ** Trace frame changes caused by command "tfind" are now notified using
1087 new async record "=traceframe-changed".
1088 ** The creation, deletion and modification of trace state variables
1089 are now notified using new async records "=tsv-created",
1090 "=tsv-deleted" and "=tsv-modified".
1091 ** The start and stop of process record are now notified using new
1092 async record "=record-started" and "=record-stopped".
1093 ** Memory changes are now notified using new async record
1095 ** The data-disassemble command response will include a "fullname" field
1096 containing the absolute file name when source has been requested.
1097 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1098 command, to allow pattern filling of memory areas.
1099 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1100 library load/unload events.
1101 ** The response to breakpoint commands and breakpoint async records
1102 includes an "installed" field containing a boolean state about each
1103 non-pending tracepoint location is whether installed on target or not.
1104 ** Output of the "-trace-status" command includes a "trace-file" field
1105 containing the name of the trace file being examined. This field is
1106 optional, and only present when examining a trace file.
1107 ** The "fullname" field is now always present along with the "file" field,
1108 even if the file cannot be found by GDB.
1110 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1111 You must have the LZMA library available when configuring GDB for this
1112 feature to be enabled. For more information, see:
1113 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1115 * New remote packets
1118 Set the size of trace buffer. The remote stub reports support for this
1119 packet to gdb's qSupported query.
1122 Enable Branch Trace Store (BTS)-based branch tracing for the current
1123 thread. The remote stub reports support for this packet to gdb's
1127 Disable branch tracing for the current thread. The remote stub reports
1128 support for this packet to gdb's qSupported query.
1131 Read the traced branches for the current thread. The remote stub
1132 reports support for this packet to gdb's qSupported query.
1134 *** Changes in GDB 7.5
1136 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1137 for more x32 ABI info.
1139 * GDB now supports access to MIPS DSP registers on Linux targets.
1141 * GDB now supports debugging microMIPS binaries.
1143 * The "info os" command on GNU/Linux can now display information on
1144 several new classes of objects managed by the operating system:
1145 "info os procgroups" lists process groups
1146 "info os files" lists file descriptors
1147 "info os sockets" lists internet-domain sockets
1148 "info os shm" lists shared-memory regions
1149 "info os semaphores" lists semaphores
1150 "info os msg" lists message queues
1151 "info os modules" lists loaded kernel modules
1153 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1154 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1155 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1156 options and inspect the probe arguments using the new $_probe_arg family
1157 of convenience variables. You can obtain more information about SystemTap
1158 in <http://sourceware.org/systemtap/>.
1160 * GDB now supports reversible debugging on ARM, it allows you to
1161 debug basic ARM and THUMB instructions, and provides
1162 record/replay support.
1164 * The option "symbol-reloading" has been deleted as it is no longer used.
1168 ** GDB commands implemented in Python can now be put in command class
1171 ** The "maint set python print-stack on|off" is now deleted.
1173 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1174 apply "flag enum"-style pretty-printing to any enum.
1176 ** gdb.lookup_symbol can now work when there is no current frame.
1178 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1179 the source at which the symbol was defined.
1181 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1182 method 'value'. The former indicates whether the symbol needs a
1183 frame in order to compute its value, and the latter computes the
1186 ** A new method 'referenced_value' on gdb.Value objects which can
1187 dereference pointer as well as C++ reference values.
1189 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1190 which return the global and static blocks (as gdb.Block objects),
1191 of the underlying symbol table, respectively.
1193 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1194 object associated with a PC value.
1196 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1197 of the address range occupied by code for the current source line.
1199 * Go language support.
1200 GDB now supports debugging programs written in the Go programming
1203 * GDBserver now supports stdio connections.
1204 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1206 * The binary "gdbtui" can no longer be built or installed.
1207 Use "gdb -tui" instead.
1209 * GDB will now print "flag" enums specially. A flag enum is one where
1210 all the enumerator values have no bits in common when pairwise
1211 "and"ed. When printing a value whose type is a flag enum, GDB will
1212 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1213 (gdb) print (enum E) 3
1216 * The filename part of a linespec will now match trailing components
1217 of a source file name. For example, "break gcc/expr.c:1000" will
1218 now set a breakpoint in build/gcc/expr.c, but not
1219 build/libcpp/expr.c.
1221 * The "info proc" and "generate-core-file" commands will now also
1222 work on remote targets connected to GDBserver on Linux.
1224 * The command "info catch" has been removed. It has been disabled
1225 since December 2007.
1227 * The "catch exception" and "catch assert" commands now accept
1228 a condition at the end of the command, much like the "break"
1229 command does. For instance:
1231 (gdb) catch exception Constraint_Error if Barrier = True
1233 Previously, it was possible to add a condition to such catchpoints,
1234 but it had to be done as a second step, after the catchpoint had been
1235 created, using the "condition" command.
1237 * The "info static-tracepoint-marker" command will now also work on
1238 native Linux targets with in-process agent.
1240 * GDB can now set breakpoints on inlined functions.
1242 * The .gdb_index section has been updated to include symbols for
1243 inlined functions. GDB will ignore older .gdb_index sections by
1244 default, which could cause symbol files to be loaded more slowly
1245 until their .gdb_index sections can be recreated. The new command
1246 "set use-deprecated-index-sections on" will cause GDB to use any older
1247 .gdb_index sections it finds. This will restore performance, but the
1248 ability to set breakpoints on inlined functions will be lost in symbol
1249 files with older .gdb_index sections.
1251 The .gdb_index section has also been updated to record more information
1252 about each symbol. This speeds up the "info variables", "info functions"
1253 and "info types" commands when used with programs having the .gdb_index
1254 section, as well as speeding up debugging with shared libraries using
1255 the .gdb_index section.
1257 * Ada support for GDB/MI Variable Objects has been added.
1259 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1264 ** New command -info-os is the MI equivalent of "info os".
1266 ** Output logs ("set logging" and related) now include MI output.
1270 ** "set use-deprecated-index-sections on|off"
1271 "show use-deprecated-index-sections on|off"
1272 Controls the use of deprecated .gdb_index sections.
1274 ** "catch load" and "catch unload" can be used to stop when a shared
1275 library is loaded or unloaded, respectively.
1277 ** "enable count" can be used to auto-disable a breakpoint after
1280 ** "info vtbl" can be used to show the virtual method tables for
1281 C++ and Java objects.
1283 ** "explore" and its sub commands "explore value" and "explore type"
1284 can be used to recursively explore values and types of
1285 expressions. These commands are available only if GDB is
1286 configured with '--with-python'.
1288 ** "info auto-load" shows status of all kinds of auto-loaded files,
1289 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1290 sequences of commands files, "info auto-load python-scripts"
1291 shows status of auto-loading Python script files,
1292 "info auto-load local-gdbinit" shows status of loading init file
1293 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1294 status of inferior specific thread debugging shared library loading.
1296 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1297 and "show auto-load-scripts" commands have been deprecated, use their
1298 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1299 and "show auto-load python-scripts" counterparts instead.
1301 ** "dprintf location,format,args..." creates a dynamic printf, which
1302 is basically a breakpoint that does a printf and immediately
1303 resumes your program's execution, so it is like a printf that you
1304 can insert dynamically at runtime instead of at compiletime.
1306 ** "set print symbol"
1308 Controls whether GDB attempts to display the symbol, if any,
1309 corresponding to addresses it prints. This defaults to "on", but
1310 you can set it to "off" to restore GDB's previous behavior.
1312 * Deprecated commands
1314 ** For the Renesas Super-H architecture, the "regs" command has been
1315 deprecated, and "info all-registers" should be used instead.
1319 Renesas RL78 rl78-*-elf
1320 HP OpenVMS ia64 ia64-hp-openvms*
1322 * GDBserver supports evaluation of breakpoint conditions. When
1323 support is advertised by GDBserver, GDB may be told to send the
1324 breakpoint conditions in bytecode form to GDBserver. GDBserver
1325 will only report the breakpoint trigger to GDB when its condition
1330 set mips compression
1331 show mips compression
1332 Select the compressed ISA encoding used in functions that have no symbol
1333 information available. The encoding can be set to either of:
1336 and is updated automatically from ELF file flags if available.
1338 set breakpoint condition-evaluation
1339 show breakpoint condition-evaluation
1340 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1341 GDBserver ("target"). Default option "auto" chooses the most efficient
1343 This option can improve debugger efficiency depending on the speed of the
1347 Disable auto-loading globally.
1350 Show auto-loading setting of all kinds of auto-loaded files.
1352 set auto-load gdb-scripts on|off
1353 show auto-load gdb-scripts
1354 Control auto-loading of GDB canned sequences of commands files.
1356 set auto-load python-scripts on|off
1357 show auto-load python-scripts
1358 Control auto-loading of Python script files.
1360 set auto-load local-gdbinit on|off
1361 show auto-load local-gdbinit
1362 Control loading of init file (.gdbinit) from current directory.
1364 set auto-load libthread-db on|off
1365 show auto-load libthread-db
1366 Control auto-loading of inferior specific thread debugging shared library.
1368 set auto-load scripts-directory <dir1>[:<dir2>...]
1369 show auto-load scripts-directory
1370 Set a list of directories from which to load auto-loaded scripts.
1371 Automatically loaded Python scripts and GDB scripts are located in one
1372 of the directories listed by this option.
1373 The delimiter (':' above) may differ according to the host platform.
1375 set auto-load safe-path <dir1>[:<dir2>...]
1376 show auto-load safe-path
1377 Set a list of directories from which it is safe to auto-load files.
1378 The delimiter (':' above) may differ according to the host platform.
1380 set debug auto-load on|off
1381 show debug auto-load
1382 Control display of debugging info for auto-loading the files above.
1384 set dprintf-style gdb|call|agent
1386 Control the way in which a dynamic printf is performed; "gdb"
1387 requests a GDB printf command, while "call" causes dprintf to call a
1388 function in the inferior. "agent" requests that the target agent
1389 (such as GDBserver) do the printing.
1391 set dprintf-function <expr>
1392 show dprintf-function
1393 set dprintf-channel <expr>
1394 show dprintf-channel
1395 Set the function and optional first argument to the call when using
1396 the "call" style of dynamic printf.
1398 set disconnected-dprintf on|off
1399 show disconnected-dprintf
1400 Control whether agent-style dynamic printfs continue to be in effect
1401 after GDB disconnects.
1403 * New configure options
1405 --with-auto-load-dir
1406 Configure default value for the 'set auto-load scripts-directory'
1407 setting above. It defaults to '$debugdir:$datadir/auto-load',
1408 $debugdir representing global debugging info directories (available
1409 via 'show debug-file-directory') and $datadir representing GDB's data
1410 directory (available via 'show data-directory').
1412 --with-auto-load-safe-path
1413 Configure default value for the 'set auto-load safe-path' setting
1414 above. It defaults to the --with-auto-load-dir setting.
1416 --without-auto-load-safe-path
1417 Set 'set auto-load safe-path' to '/', effectively disabling this
1420 * New remote packets
1422 z0/z1 conditional breakpoints extension
1424 The z0/z1 breakpoint insertion packets have been extended to carry
1425 a list of conditional expressions over to the remote stub depending on the
1426 condition evaluation mode. The use of this extension can be controlled
1427 via the "set remote conditional-breakpoints-packet" command.
1431 Specify the signals which the remote stub may pass to the debugged
1432 program without GDB involvement.
1434 * New command line options
1436 --init-command=FILE, -ix Like --command, -x but execute it
1437 before loading inferior.
1438 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1439 execute it before loading inferior.
1441 *** Changes in GDB 7.4
1443 * GDB now handles ambiguous linespecs more consistently; the existing
1444 FILE:LINE support has been expanded to other types of linespecs. A
1445 breakpoint will now be set on all matching locations in all
1446 inferiors, and locations will be added or removed according to
1449 * GDB now allows you to skip uninteresting functions and files when
1450 stepping with the "skip function" and "skip file" commands.
1452 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1453 and "show remote hardware-watchpoint-length-limit". These allows to
1454 set or show the maximum length limit (in bytes) of a remote
1455 target hardware watchpoint.
1457 This allows e.g. to use "unlimited" hardware watchpoints with the
1458 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1459 watchpoints are slower than real hardware watchpoints but are
1460 significantly faster than gdb software watchpoints.
1464 ** The register_pretty_printer function in module gdb.printing now takes
1465 an optional `replace' argument. If True, the new printer replaces any
1468 ** The "maint set python print-stack on|off" command has been
1469 deprecated and will be deleted in GDB 7.5.
1470 A new command: "set python print-stack none|full|message" has
1471 replaced it. Additionally, the default for "print-stack" is
1472 now "message", which just prints the error message without
1475 ** A prompt substitution hook (prompt_hook) is now available to the
1478 ** A new Python module, gdb.prompt has been added to the GDB Python
1479 modules library. This module provides functionality for
1480 escape sequences in prompts (used by set/show
1481 extended-prompt). These escape sequences are replaced by their
1482 corresponding value.
1484 ** Python commands and convenience-functions located in
1485 'data-directory'/python/gdb/command and
1486 'data-directory'/python/gdb/function are now automatically loaded
1489 ** Blocks now provide four new attributes. global_block and
1490 static_block will return the global and static blocks
1491 respectively. is_static and is_global are boolean attributes
1492 that indicate if the block is one of those two types.
1494 ** Symbols now provide the "type" attribute, the type of the symbol.
1496 ** The "gdb.breakpoint" function has been deprecated in favor of
1499 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1500 of a function. This class is based on the "finish" command
1501 available in the CLI.
1503 ** Type objects for struct and union types now allow access to
1504 the fields using standard Python dictionary (mapping) methods.
1505 For example, "some_type['myfield']" now works, as does
1506 "some_type.items()".
1508 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1511 ** A new function, "deep_items" has been added to the gdb.types
1512 module in the GDB Python modules library. This function returns
1513 an iterator over the fields of a struct or union type. Unlike
1514 the standard Python "iteritems" method, it will recursively traverse
1515 any anonymous fields.
1519 ** "*stopped" events can report several new "reason"s, such as
1522 ** Breakpoint changes are now notified using new async records, like
1523 "=breakpoint-modified".
1525 ** New command -ada-task-info.
1527 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1528 $sdir specifies the default system locations of shared libraries.
1529 $pdir specifies the directory where the libpthread used by the application
1532 GDB no longer looks in $sdir and $pdir after it has searched the directories
1533 mentioned in libthread-db-search-path. If you want to search those
1534 directories, they must be specified in libthread-db-search-path.
1535 The default value of libthread-db-search-path on GNU/Linux and Solaris
1536 systems is now "$sdir:$pdir".
1538 $pdir is not supported by gdbserver, it is currently ignored.
1539 $sdir is supported by gdbserver.
1541 * New configure option --with-iconv-bin.
1542 When using the internationalization support like the one in the GNU C
1543 library, GDB will invoke the "iconv" program to get a list of supported
1544 character sets. If this program lives in a non-standard location, one can
1545 use this option to specify where to find it.
1547 * When natively debugging programs on PowerPC BookE processors running
1548 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1549 watchpoints, which specify a mask in addition to an address to watch.
1550 The mask specifies that some bits of an address (the bits which are
1551 reset in the mask) should be ignored when matching the address accessed
1552 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1553 section in the user manual for more details.
1555 * The new option --once causes GDBserver to stop listening for connections once
1556 the first connection is made. The listening port used by GDBserver will
1557 become available after that.
1559 * New commands "info macros" and "alias" have been added.
1561 * New function parameters suffix @entry specifies value of function parameter
1562 at the time the function got called. Entry values are available only since
1568 "!" is now an alias of the "shell" command.
1569 Note that no space is needed between "!" and SHELL COMMAND.
1573 watch EXPRESSION mask MASK_VALUE
1574 The watch command now supports the mask argument which allows creation
1575 of masked watchpoints, if the current architecture supports this feature.
1577 info auto-load-scripts [REGEXP]
1578 This command was formerly named "maintenance print section-scripts".
1579 It is now generally useful and is no longer a maintenance-only command.
1581 info macro [-all] [--] MACRO
1582 The info macro command has new options `-all' and `--'. The first for
1583 printing all definitions of a macro. The second for explicitly specifying
1584 the end of arguments and the beginning of the macro name in case the macro
1585 name starts with a hyphen.
1587 collect[/s] EXPRESSIONS
1588 The tracepoint collect command now takes an optional modifier "/s"
1589 that directs it to dereference pointer-to-character types and
1590 collect the bytes of memory up to a zero byte. The behavior is
1591 similar to what you see when you use the regular print command on a
1592 string. An optional integer following the "/s" sets a bound on the
1593 number of bytes that will be collected.
1596 The trace start command now interprets any supplied arguments as a
1597 note to be recorded with the trace run, with an effect similar to
1598 setting the variable trace-notes.
1601 The trace stop command now interprets any arguments as a note to be
1602 mentioned along with the tstatus report that the trace was stopped
1603 with a command. The effect is similar to setting the variable
1606 * Tracepoints can now be enabled and disabled at any time after a trace
1607 experiment has been started using the standard "enable" and "disable"
1608 commands. It is now possible to start a trace experiment with no enabled
1609 tracepoints; GDB will display a warning, but will allow the experiment to
1610 begin, assuming that tracepoints will be enabled as needed while the trace
1613 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1614 locations with 4-byte instructions, when they were previously
1615 limited to locations with instructions of 5 bytes or longer.
1619 set debug dwarf2-read
1620 show debug dwarf2-read
1621 Turns on or off display of debugging messages related to reading
1622 DWARF debug info. The default is off.
1624 set debug symtab-create
1625 show debug symtab-create
1626 Turns on or off display of debugging messages related to symbol table
1627 creation. The default is off.
1630 show extended-prompt
1631 Set the GDB prompt, and allow escape sequences to be inserted to
1632 display miscellaneous information (see 'help set extended-prompt'
1633 for the list of sequences). This prompt (and any information
1634 accessed through the escape sequences) is updated every time the
1635 prompt is displayed.
1637 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1638 show print entry-values
1639 Set printing of frame argument values at function entry. In some cases
1640 GDB can determine the value of function argument which was passed by the
1641 function caller, even if the value was modified inside the called function.
1643 set debug entry-values
1644 show debug entry-values
1645 Control display of debugging info for determining frame argument values at
1646 function entry and virtual tail call frames.
1648 set basenames-may-differ
1649 show basenames-may-differ
1650 Set whether a source file may have multiple base names.
1651 (A "base name" is the name of a file with the directory part removed.
1652 Example: The base name of "/home/user/hello.c" is "hello.c".)
1653 If set, GDB will canonicalize file names (e.g., expand symlinks)
1654 before comparing them. Canonicalization is an expensive operation,
1655 but it allows the same file be known by more than one base name.
1656 If not set (the default), all source files are assumed to have just
1657 one base name, and gdb will do file name comparisons more efficiently.
1663 Set a user name and notes for the current and any future trace runs.
1664 This is useful for long-running and/or disconnected traces, to
1665 inform others (or yourself) as to who is running the trace, supply
1666 contact information, or otherwise explain what is going on.
1668 set trace-stop-notes
1669 show trace-stop-notes
1670 Set a note attached to the trace run, that is displayed when the
1671 trace has been stopped by a tstop command. This is useful for
1672 instance as an explanation, if you are stopping a trace run that was
1673 started by someone else.
1675 * New remote packets
1679 Dynamically enable a tracepoint in a started trace experiment.
1683 Dynamically disable a tracepoint in a started trace experiment.
1687 Set the user and notes of the trace run.
1691 Query the current status of a tracepoint.
1695 Query the minimum length of instruction at which a fast tracepoint may
1698 * Dcache size (number of lines) and line-size are now runtime-configurable
1699 via "set dcache line" and "set dcache line-size" commands.
1703 Texas Instruments TMS320C6x tic6x-*-*
1707 Renesas RL78 rl78-*-elf
1709 *** Changes in GDB 7.3.1
1711 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1713 *** Changes in GDB 7.3
1715 * GDB has a new command: "thread find [REGEXP]".
1716 It finds the thread id whose name, target id, or thread extra info
1717 matches the given regular expression.
1719 * The "catch syscall" command now works on mips*-linux* targets.
1721 * The -data-disassemble MI command now supports modes 2 and 3 for
1722 dumping the instruction opcodes.
1724 * New command line options
1726 -data-directory DIR Specify DIR as the "data-directory".
1727 This is mostly for testing purposes.
1729 * The "maint set python auto-load on|off" command has been renamed to
1730 "set auto-load-scripts on|off".
1732 * GDB has a new command: "set directories".
1733 It is like the "dir" command except that it replaces the
1734 source path list instead of augmenting it.
1736 * GDB now understands thread names.
1738 On GNU/Linux, "info threads" will display the thread name as set by
1739 prctl or pthread_setname_np.
1741 There is also a new command, "thread name", which can be used to
1742 assign a name internally for GDB to display.
1745 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1746 has been integrated into GDB.
1750 ** The function gdb.Write now accepts an optional keyword 'stream'.
1751 This keyword, when provided, will direct the output to either
1752 stdout, stderr, or GDB's logging output.
1754 ** Parameters can now be be sub-classed in Python, and in particular
1755 you may implement the get_set_doc and get_show_doc functions.
1756 This improves how Parameter set/show documentation is processed
1757 and allows for more dynamic content.
1759 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1760 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1761 have an is_valid method.
1763 ** Breakpoints can now be sub-classed in Python, and in particular
1764 you may implement a 'stop' function that is executed each time
1765 the inferior reaches that breakpoint.
1767 ** New function gdb.lookup_global_symbol looks up a global symbol.
1769 ** GDB values in Python are now callable if the value represents a
1770 function. For example, if 'some_value' represents a function that
1771 takes two integer parameters and returns a value, you can call
1772 that function like so:
1774 result = some_value (10,20)
1776 ** Module gdb.types has been added.
1777 It contains a collection of utilities for working with gdb.Types objects:
1778 get_basic_type, has_field, make_enum_dict.
1780 ** Module gdb.printing has been added.
1781 It contains utilities for writing and registering pretty-printers.
1782 New classes: PrettyPrinter, SubPrettyPrinter,
1783 RegexpCollectionPrettyPrinter.
1784 New function: register_pretty_printer.
1786 ** New commands "info pretty-printers", "enable pretty-printer" and
1787 "disable pretty-printer" have been added.
1789 ** gdb.parameter("directories") is now available.
1791 ** New function gdb.newest_frame returns the newest frame in the
1794 ** The gdb.InferiorThread class has a new "name" attribute. This
1795 holds the thread's name.
1797 ** Python Support for Inferior events.
1798 Python scripts can add observers to be notified of events
1799 occurring in the process being debugged.
1800 The following events are currently supported:
1801 - gdb.events.cont Continue event.
1802 - gdb.events.exited Inferior exited event.
1803 - gdb.events.stop Signal received, and Breakpoint hit events.
1807 ** GDB now puts template parameters in scope when debugging in an
1808 instantiation. For example, if you have:
1810 template<int X> int func (void) { return X; }
1812 then if you step into func<5>, "print X" will show "5". This
1813 feature requires proper debuginfo support from the compiler; it
1814 was added to GCC 4.5.
1816 ** The motion commands "next", "finish", "until", and "advance" now
1817 work better when exceptions are thrown. In particular, GDB will
1818 no longer lose control of the inferior; instead, the GDB will
1819 stop the inferior at the point at which the exception is caught.
1820 This functionality requires a change in the exception handling
1821 code that was introduced in GCC 4.5.
1823 * GDB now follows GCC's rules on accessing volatile objects when
1824 reading or writing target state during expression evaluation.
1825 One notable difference to prior behavior is that "print x = 0"
1826 no longer generates a read of x; the value of the assignment is
1827 now always taken directly from the value being assigned.
1829 * GDB now has some support for using labels in the program's source in
1830 linespecs. For instance, you can use "advance label" to continue
1831 execution to a label.
1833 * GDB now has support for reading and writing a new .gdb_index
1834 section. This section holds a fast index of DWARF debugging
1835 information and can be used to greatly speed up GDB startup and
1836 operation. See the documentation for `save gdb-index' for details.
1838 * The "watch" command now accepts an optional "-location" argument.
1839 When used, this causes GDB to watch the memory referred to by the
1840 expression. Such a watchpoint is never deleted due to it going out
1843 * GDB now supports thread debugging of core dumps on GNU/Linux.
1845 GDB now activates thread debugging using the libthread_db library
1846 when debugging GNU/Linux core dumps, similarly to when debugging
1847 live processes. As a result, when debugging a core dump file, GDB
1848 is now able to display pthread_t ids of threads. For example, "info
1849 threads" shows the same output as when debugging the process when it
1850 was live. In earlier releases, you'd see something like this:
1853 * 1 LWP 6780 main () at main.c:10
1855 While now you see this:
1858 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1860 It is also now possible to inspect TLS variables when debugging core
1863 When debugging a core dump generated on a machine other than the one
1864 used to run GDB, you may need to point GDB at the correct
1865 libthread_db library with the "set libthread-db-search-path"
1866 command. See the user manual for more details on this command.
1868 * When natively debugging programs on PowerPC BookE processors running
1869 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1870 which stop execution of the inferior whenever it executes an instruction
1871 at any address within the specified range. See the "PowerPC Embedded"
1872 section in the user manual for more details.
1874 * New features in the GDB remote stub, GDBserver
1876 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1877 and i686 LynxOS (version 5.x).
1879 ** GDBserver is now supported on Blackfin Linux.
1881 * New native configurations
1883 ia64 HP-UX ia64-*-hpux*
1887 Analog Devices, Inc. Blackfin Processor bfin-*
1889 * Ada task switching is now supported on sparc-elf targets when
1890 debugging a program using the Ravenscar Profile. For more information,
1891 see the "Tasking Support when using the Ravenscar Profile" section
1892 in the GDB user manual.
1894 * Guile support was removed.
1896 * New features in the GNU simulator
1898 ** The --map-info flag lists all known core mappings.
1900 ** CFI flashes may be simulated via the "cfi" device.
1902 *** Changes in GDB 7.2
1904 * Shared library support for remote targets by default
1906 When GDB is configured for a generic, non-OS specific target, like
1907 for example, --target=arm-eabi or one of the many *-*-elf targets,
1908 GDB now queries remote stubs for loaded shared libraries using the
1909 `qXfer:libraries:read' packet. Previously, shared library support
1910 was always disabled for such configurations.
1914 ** Argument Dependent Lookup (ADL)
1916 In C++ ADL lookup directs function search to the namespaces of its
1917 arguments even if the namespace has not been imported.
1927 Here the compiler will search for `foo' in the namespace of 'b'
1928 and find A::foo. GDB now supports this. This construct is commonly
1929 used in the Standard Template Library for operators.
1931 ** Improved User Defined Operator Support
1933 In addition to member operators, GDB now supports lookup of operators
1934 defined in a namespace and imported with a `using' directive, operators
1935 defined in the global scope, operators imported implicitly from an
1936 anonymous namespace, and the ADL operators mentioned in the previous
1938 GDB now also supports proper overload resolution for all the previously
1939 mentioned flavors of operators.
1941 ** static const class members
1943 Printing of static const class members that are initialized in the
1944 class definition has been fixed.
1946 * Windows Thread Information Block access.
1948 On Windows targets, GDB now supports displaying the Windows Thread
1949 Information Block (TIB) structure. This structure is visible either
1950 by using the new command `info w32 thread-information-block' or, by
1951 dereferencing the new convenience variable named `$_tlb', a
1952 thread-specific pointer to the TIB. This feature is also supported
1953 when remote debugging using GDBserver.
1955 * Static tracepoints
1957 Static tracepoints are calls in the user program into a tracing
1958 library. One such library is a port of the LTTng kernel tracer to
1959 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1960 When debugging with GDBserver, GDB now supports combining the GDB
1961 tracepoint machinery with such libraries. For example: the user can
1962 use GDB to probe a static tracepoint marker (a call from the user
1963 program into the tracing library) with the new "strace" command (see
1964 "New commands" below). This creates a "static tracepoint" in the
1965 breakpoint list, that can be manipulated with the same feature set
1966 as fast and regular tracepoints. E.g., collect registers, local and
1967 global variables, collect trace state variables, and define
1968 tracepoint conditions. In addition, the user can collect extra
1969 static tracepoint marker specific data, by collecting the new
1970 $_sdata internal variable. When analyzing the trace buffer, you can
1971 inspect $_sdata like any other variable available to GDB. For more
1972 information, see the "Tracepoints" chapter in GDB user manual. New
1973 remote packets have been defined to support static tracepoints, see
1974 the "New remote packets" section below.
1976 * Better reconstruction of tracepoints after disconnected tracing
1978 GDB will attempt to download the original source form of tracepoint
1979 definitions when starting a trace run, and then will upload these
1980 upon reconnection to the target, resulting in a more accurate
1981 reconstruction of the tracepoints that are in use on the target.
1985 You can now exercise direct control over the ways that GDB can
1986 affect your program. For instance, you can disallow the setting of
1987 breakpoints, so that the program can run continuously (assuming
1988 non-stop mode). In addition, the "observer" variable is available
1989 to switch all of the different controls; in observer mode, GDB
1990 cannot affect the target's behavior at all, which is useful for
1991 tasks like diagnosing live systems in the field.
1993 * The new convenience variable $_thread holds the number of the
1996 * New remote packets
2000 Return the address of the Windows Thread Information Block of a given thread.
2004 In response to several of the tracepoint packets, the target may now
2005 also respond with a number of intermediate `qRelocInsn' request
2006 packets before the final result packet, to have GDB handle
2007 relocating an instruction to execute at a different address. This
2008 is particularly useful for stubs that support fast tracepoints. GDB
2009 reports support for this feature in the qSupported packet.
2013 List static tracepoint markers in the target program.
2017 List static tracepoint markers at a given address in the target
2020 qXfer:statictrace:read
2022 Read the static trace data collected (by a `collect $_sdata'
2023 tracepoint action). The remote stub reports support for this packet
2024 to gdb's qSupported query.
2028 Send the current settings of GDB's permission flags.
2032 Send part of the source (textual) form of a tracepoint definition,
2033 which includes location, conditional, and action list.
2035 * The source command now accepts a -s option to force searching for the
2036 script in the source search path even if the script name specifies
2039 * New features in the GDB remote stub, GDBserver
2041 - GDBserver now support tracepoints (including fast tracepoints, and
2042 static tracepoints). The feature is currently supported by the
2043 i386-linux and amd64-linux builds. See the "Tracepoints support
2044 in gdbserver" section in the manual for more information.
2046 GDBserver JIT compiles the tracepoint's conditional agent
2047 expression bytecode into native code whenever possible for low
2048 overhead dynamic tracepoints conditionals. For such tracepoints,
2049 an expression that examines program state is evaluated when the
2050 tracepoint is reached, in order to determine whether to capture
2051 trace data. If the condition is simple and false, processing the
2052 tracepoint finishes very quickly and no data is gathered.
2054 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2055 for static tracepoints support.
2057 - GDBserver now supports x86_64 Windows 64-bit debugging.
2059 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2060 it understands register description.
2062 * The --batch flag now disables pagination and queries.
2064 * X86 general purpose registers
2066 GDB now supports reading/writing byte, word and double-word x86
2067 general purpose registers directly. This means you can use, say,
2068 $ah or $ax to refer, respectively, to the byte register AH and
2069 16-bit word register AX that are actually portions of the 32-bit
2070 register EAX or 64-bit register RAX.
2072 * The `commands' command now accepts a range of breakpoints to modify.
2073 A plain `commands' following a command that creates multiple
2074 breakpoints affects all the breakpoints set by that command. This
2075 applies to breakpoints set by `rbreak', and also applies when a
2076 single `break' command creates multiple breakpoints (e.g.,
2077 breakpoints on overloaded c++ functions).
2079 * The `rbreak' command now accepts a filename specification as part of
2080 its argument, limiting the functions selected by the regex to those
2081 in the specified file.
2083 * Support for remote debugging Windows and SymbianOS shared libraries
2084 from Unix hosts has been improved. Non Windows GDB builds now can
2085 understand target reported file names that follow MS-DOS based file
2086 system semantics, such as file names that include drive letters and
2087 use the backslash character as directory separator. This makes it
2088 possible to transparently use the "set sysroot" and "set
2089 solib-search-path" on Unix hosts to point as host copies of the
2090 target's shared libraries. See the new command "set
2091 target-file-system-kind" described below, and the "Commands to
2092 specify files" section in the user manual for more information.
2096 eval template, expressions...
2097 Convert the values of one or more expressions under the control
2098 of the string template to a command line, and call it.
2100 set target-file-system-kind unix|dos-based|auto
2101 show target-file-system-kind
2102 Set or show the assumed file system kind for target reported file
2105 save breakpoints <filename>
2106 Save all current breakpoint definitions to a file suitable for use
2107 in a later debugging session. To read the saved breakpoint
2108 definitions, use the `source' command.
2110 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2113 info static-tracepoint-markers
2114 Display information about static tracepoint markers in the target.
2116 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2117 Define a static tracepoint by probing a marker at the given
2118 function, line, address, or marker ID.
2122 Enable and disable observer mode.
2124 set may-write-registers on|off
2125 set may-write-memory on|off
2126 set may-insert-breakpoints on|off
2127 set may-insert-tracepoints on|off
2128 set may-insert-fast-tracepoints on|off
2129 set may-interrupt on|off
2130 Set individual permissions for GDB effects on the target. Note that
2131 some of these settings can have undesirable or surprising
2132 consequences, particularly when changed in the middle of a session.
2133 For instance, disabling the writing of memory can prevent
2134 breakpoints from being inserted, cause single-stepping to fail, or
2135 even crash your program, if you disable after breakpoints have been
2136 inserted. However, GDB should not crash.
2138 set record memory-query on|off
2139 show record memory-query
2140 Control whether to stop the inferior if memory changes caused
2141 by an instruction cannot be recorded.
2146 The disassemble command now supports "start,+length" form of two arguments.
2150 ** GDB now provides a new directory location, called the python directory,
2151 where Python scripts written for GDB can be installed. The location
2152 of that directory is <data-directory>/python, where <data-directory>
2153 is the GDB data directory. For more details, see section `Scripting
2154 GDB using Python' in the manual.
2156 ** The GDB Python API now has access to breakpoints, symbols, symbol
2157 tables, program spaces, inferiors, threads and frame's code blocks.
2158 Additionally, GDB Parameters can now be created from the API, and
2159 manipulated via set/show in the CLI.
2161 ** New functions gdb.target_charset, gdb.target_wide_charset,
2162 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2164 ** New exception gdb.GdbError.
2166 ** Pretty-printers are now also looked up in the current program space.
2168 ** Pretty-printers can now be individually enabled and disabled.
2170 ** GDB now looks for names of Python scripts to auto-load in a
2171 special section named `.debug_gdb_scripts', in addition to looking
2172 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2174 * Tracepoint actions were unified with breakpoint commands. In particular,
2175 there are no longer differences in "info break" output for breakpoints and
2176 tracepoints and the "commands" command can be used for both tracepoints and
2177 regular breakpoints.
2181 ARM Symbian arm*-*-symbianelf*
2183 * D language support.
2184 GDB now supports debugging programs written in the D programming
2187 * GDB now supports the extended ptrace interface for PowerPC which is
2188 available since Linux kernel version 2.6.34. This automatically enables
2189 any hardware breakpoints and additional hardware watchpoints available in
2190 the processor. The old ptrace interface exposes just one hardware
2191 watchpoint and no hardware breakpoints.
2193 * GDB is now able to use the Data Value Compare (DVC) register available on
2194 embedded PowerPC processors to implement in hardware simple watchpoint
2195 conditions of the form:
2197 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2199 This works in native GDB running on Linux kernels with the extended ptrace
2200 interface mentioned above.
2202 *** Changes in GDB 7.1
2206 ** Namespace Support
2208 GDB now supports importing of namespaces in C++. This enables the
2209 user to inspect variables from imported namespaces. Support for
2210 namepace aliasing has also been added. So, if a namespace is
2211 aliased in the current scope (e.g. namepace C=A; ) the user can
2212 print variables using the alias (e.g. (gdb) print C::x).
2216 All known bugs relating to the printing of virtual base class were
2217 fixed. It is now possible to call overloaded static methods using a
2222 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2223 and reinterpret_cast<> are now handled by the C++ expression parser.
2227 Xilinx MicroBlaze microblaze-*-*
2232 Xilinx MicroBlaze microblaze
2235 * Multi-program debugging.
2237 GDB now has support for multi-program (a.k.a. multi-executable or
2238 multi-exec) debugging. This allows for debugging multiple inferiors
2239 simultaneously each running a different program under the same GDB
2240 session. See "Debugging Multiple Inferiors and Programs" in the
2241 manual for more information. This implied some user visible changes
2242 in the multi-inferior support. For example, "info inferiors" now
2243 lists inferiors that are not running yet or that have exited
2244 already. See also "New commands" and "New options" below.
2246 * New tracing features
2248 GDB's tracepoint facility now includes several new features:
2250 ** Trace state variables
2252 GDB tracepoints now include support for trace state variables, which
2253 are variables managed by the target agent during a tracing
2254 experiment. They are useful for tracepoints that trigger each
2255 other, so for instance one tracepoint can count hits in a variable,
2256 and then a second tracepoint has a condition that is true when the
2257 count reaches a particular value. Trace state variables share the
2258 $-syntax of GDB convenience variables, and can appear in both
2259 tracepoint actions and condition expressions. Use the "tvariable"
2260 command to create, and "info tvariables" to view; see "Trace State
2261 Variables" in the manual for more detail.
2265 GDB now includes an option for defining fast tracepoints, which
2266 targets may implement more efficiently, such as by installing a jump
2267 into the target agent rather than a trap instruction. The resulting
2268 speedup can be by two orders of magnitude or more, although the
2269 tradeoff is that some program locations on some target architectures
2270 might not allow fast tracepoint installation, for instance if the
2271 instruction to be replaced is shorter than the jump. To request a
2272 fast tracepoint, use the "ftrace" command, with syntax identical to
2273 the regular trace command.
2275 ** Disconnected tracing
2277 It is now possible to detach GDB from the target while it is running
2278 a trace experiment, then reconnect later to see how the experiment
2279 is going. In addition, a new variable disconnected-tracing lets you
2280 tell the target agent whether to continue running a trace if the
2281 connection is lost unexpectedly.
2285 GDB now has the ability to save the trace buffer into a file, and
2286 then use that file as a target, similarly to you can do with
2287 corefiles. You can select trace frames, print data that was
2288 collected in them, and use tstatus to display the state of the
2289 tracing run at the moment that it was saved. To create a trace
2290 file, use "tsave <filename>", and to use it, do "target tfile
2293 ** Circular trace buffer
2295 You can ask the target agent to handle the trace buffer as a
2296 circular buffer, discarding the oldest trace frames to make room for
2297 newer ones, by setting circular-trace-buffer to on. This feature may
2298 not be available for all target agents.
2303 The disassemble command, when invoked with two arguments, now requires
2304 the arguments to be comma-separated.
2307 The info variables command now displays variable definitions. Files
2308 which only declare a variable are not shown.
2311 The source command is now capable of sourcing Python scripts.
2312 This feature is dependent on the debugger being build with Python
2315 Related to this enhancement is also the introduction of a new command
2316 "set script-extension" (see below).
2318 * New commands (for set/show, see "New options" below)
2320 record save [<FILENAME>]
2321 Save a file (in core file format) containing the process record
2322 execution log for replay debugging at a later time.
2324 record restore <FILENAME>
2325 Restore the process record execution log that was saved at an
2326 earlier time, for replay debugging.
2328 add-inferior [-copies <N>] [-exec <FILENAME>]
2331 clone-inferior [-copies <N>] [ID]
2332 Make a new inferior ready to execute the same program another
2333 inferior has loaded.
2338 maint info program-spaces
2339 List the program spaces loaded into GDB.
2341 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2342 show remote interrupt-sequence
2343 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2344 as the sequence to the remote target in order to interrupt the execution.
2345 Ctrl-C is a default. Some system prefers BREAK which is high level of
2346 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2347 Magic SysRq g. It is BREAK signal and character 'g'.
2349 set remote interrupt-on-connect [on | off]
2350 show remote interrupt-on-connect
2351 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2352 remote target when gdb connects to it. This is needed when you debug
2355 set remotebreak [on | off]
2357 Deprecated. Use "set/show remote interrupt-sequence" instead.
2359 tvariable $NAME [ = EXP ]
2360 Create or modify a trace state variable.
2363 List trace state variables and their values.
2365 delete tvariable $NAME ...
2366 Delete one or more trace state variables.
2369 Evaluate the given expressions without collecting anything into the
2370 trace buffer. (Valid in tracepoint actions only.)
2372 ftrace FN / FILE:LINE / *ADDR
2373 Define a fast tracepoint at the given function, line, or address.
2375 * New expression syntax
2377 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2378 GDB now parses 0b101010 identically with 42.
2382 set follow-exec-mode new|same
2383 show follow-exec-mode
2384 Control whether GDB reuses the same inferior across an exec call or
2385 creates a new one. This is useful to be able to restart the old
2386 executable after the inferior having done an exec call.
2388 set default-collect EXPR, ...
2389 show default-collect
2390 Define a list of expressions to be collected at each tracepoint.
2391 This is a useful way to ensure essential items are not overlooked,
2392 such as registers or a critical global variable.
2394 set disconnected-tracing
2395 show disconnected-tracing
2396 If set to 1, the target is instructed to continue tracing if it
2397 loses its connection to GDB. If 0, the target is to stop tracing
2400 set circular-trace-buffer
2401 show circular-trace-buffer
2402 If set to on, the target is instructed to use a circular trace buffer
2403 and discard the oldest trace frames instead of stopping the trace due
2404 to a full trace buffer. If set to off, the trace stops when the buffer
2405 fills up. Some targets may not support this.
2407 set script-extension off|soft|strict
2408 show script-extension
2409 If set to "off", the debugger does not perform any script language
2410 recognition, and all sourced files are assumed to be GDB scripts.
2411 If set to "soft" (the default), files are sourced according to
2412 filename extension, falling back to GDB scripts if the first
2414 If set to "strict", files are sourced according to filename extension.
2416 set ada trust-PAD-over-XVS on|off
2417 show ada trust-PAD-over-XVS
2418 If off, activate a workaround against a bug in the debugging information
2419 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2420 the GCC sources for more information about the GNAT encoding and
2421 PAD types in particular). It is always safe to set this option to
2422 off, but this introduces a slight performance penalty. The default
2425 * Python API Improvements
2427 ** GDB provides the new class gdb.LazyString. This is useful in
2428 some pretty-printing cases. The new method gdb.Value.lazy_string
2429 provides a simple way to create objects of this type.
2431 ** The fields returned by gdb.Type.fields now have an
2432 `is_base_class' attribute.
2434 ** The new method gdb.Type.range returns the range of an array type.
2436 ** The new method gdb.parse_and_eval can be used to parse and
2437 evaluate an expression.
2439 * New remote packets
2442 Define a trace state variable.
2445 Get the current value of a trace state variable.
2448 Set desired tracing behavior upon disconnection.
2451 Set the trace buffer to be linear or circular.
2454 Get data about the tracepoints currently in use.
2458 Process record now works correctly with hardware watchpoints.
2460 Multiple bug fixes have been made to the mips-irix port, making it
2461 much more reliable. In particular:
2462 - Debugging threaded applications is now possible again. Previously,
2463 GDB would hang while starting the program, or while waiting for
2464 the program to stop at a breakpoint.
2465 - Attaching to a running process no longer hangs.
2466 - An error occurring while loading a core file has been fixed.
2467 - Changing the value of the PC register now works again. This fixes
2468 problems observed when using the "jump" command, or when calling
2469 a function from GDB, or even when assigning a new value to $pc.
2470 - With the "finish" and "return" commands, the return value for functions
2471 returning a small array is now correctly printed.
2472 - It is now possible to break on shared library code which gets executed
2473 during a shared library init phase (code executed while executing
2474 their .init section). Previously, the breakpoint would have no effect.
2475 - GDB is now able to backtrace through the signal handler for
2476 non-threaded programs.
2478 PIE (Position Independent Executable) programs debugging is now supported.
2479 This includes debugging execution of PIC (Position Independent Code) shared
2480 libraries although for that, it should be possible to run such libraries as an
2483 *** Changes in GDB 7.0
2485 * GDB now has an interface for JIT compilation. Applications that
2486 dynamically generate code can create symbol files in memory and register
2487 them with GDB. For users, the feature should work transparently, and
2488 for JIT developers, the interface is documented in the GDB manual in the
2489 "JIT Compilation Interface" chapter.
2491 * Tracepoints may now be conditional. The syntax is as for
2492 breakpoints; either an "if" clause appended to the "trace" command,
2493 or the "condition" command is available. GDB sends the condition to
2494 the target for evaluation using the same bytecode format as is used
2495 for tracepoint actions.
2497 * The disassemble command now supports: an optional /r modifier, print the
2498 raw instructions in hex as well as in symbolic form, and an optional /m
2499 modifier to print mixed source+assembly.
2501 * Process record and replay
2503 In a architecture environment that supports ``process record and
2504 replay'', ``process record and replay'' target can record a log of
2505 the process execution, and replay it with both forward and reverse
2508 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2509 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2510 set execution-direction {forward|reverse}, for targets that support
2513 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2514 feature is available with a native GDB running on kernel version
2517 * GDB now has support for multi-byte and wide character sets on the
2518 target. Strings whose character type is wchar_t, char16_t, or
2519 char32_t are now correctly printed. GDB supports wide- and unicode-
2520 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2521 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2522 `printf'. This feature requires iconv to work properly; if your
2523 system does not have a working iconv, GDB can use GNU libiconv. See
2524 the installation instructions for more information.
2526 * GDB now supports automatic retrieval of shared library files from
2527 remote targets. To use this feature, specify a system root that begins
2528 with the `remote:' prefix, either via the `set sysroot' command or via
2529 the `--with-sysroot' configure-time option.
2531 * "info sharedlibrary" now takes an optional regex of libraries to show,
2532 and it now reports if a shared library has no debugging information.
2534 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2535 now complete on file names.
2537 * When completing in expressions, gdb will attempt to limit
2538 completions to allowable structure or union fields, where appropriate.
2539 For instance, consider:
2541 # struct example { int f1; double f2; };
2542 # struct example variable;
2545 If the user types TAB at the end of this command line, the available
2546 completions will be "f1" and "f2".
2548 * Inlined functions are now supported. They show up in backtraces, and
2549 the "step", "next", and "finish" commands handle them automatically.
2551 * GDB now supports the token-splicing (##) and stringification (#)
2552 operators when expanding macros. It also supports variable-arity
2555 * GDB now supports inspecting extra signal information, exported by
2556 the new $_siginfo convenience variable. The feature is currently
2557 implemented on linux ARM, i386 and amd64.
2559 * GDB can now display the VFP floating point registers and NEON vector
2560 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2561 can provide these registers (requires Linux 2.6.30 or later). Remote
2562 and simulator targets may also provide them.
2564 * New remote packets
2567 Search memory for a sequence of bytes.
2570 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2571 operation over reliable transport links. Use of this packet is
2572 controlled by the `set remote noack-packet' command.
2575 Kill the process with the specified process ID. Use this in preference
2576 to `k' when multiprocess protocol extensions are supported.
2579 Obtains additional operating system information
2583 Read or write additional signal information.
2585 * Removed remote protocol undocumented extension
2587 An undocumented extension to the remote protocol's `S' stop reply
2588 packet that permited the stub to pass a process id was removed.
2589 Remote servers should use the `T' stop reply packet instead.
2591 * GDB now supports multiple function calling conventions according to the
2592 DWARF-2 DW_AT_calling_convention function attribute.
2594 * The SH target utilizes the aforementioned change to distinguish between gcc
2595 and Renesas calling convention. It also adds the new CLI commands
2596 `set/show sh calling-convention'.
2598 * GDB can now read compressed debug sections, as produced by GNU gold
2599 with the --compress-debug-sections=zlib flag.
2601 * 64-bit core files are now supported on AIX.
2603 * Thread switching is now supported on Tru64.
2605 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2606 which will be allocated using malloc later in program execution.
2608 * The qXfer:libraries:read remote procotol packet now allows passing a
2609 list of section offsets.
2611 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2612 conditions handling signals delivered during attach or thread creation
2613 have also been fixed.
2615 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2616 From the user's standpoint, all unqualified instances of True and False
2617 are treated as the standard definitions, regardless of context.
2619 * GDB now parses C++ symbol and type names more flexibly. For
2622 template<typename T> class C { };
2625 GDB will now correctly handle all of:
2627 ptype C<char const *>
2628 ptype C<char const*>
2629 ptype C<const char *>
2630 ptype C<const char*>
2632 * New features in the GDB remote stub, gdbserver
2634 - The "--wrapper" command-line argument tells gdbserver to use a
2635 wrapper program to launch programs for debugging.
2637 - On PowerPC and S/390 targets, it is now possible to use a single
2638 gdbserver executable to debug both 32-bit and 64-bit programs.
2639 (This requires gdbserver itself to be built as a 64-bit executable.)
2641 - gdbserver uses the new noack protocol mode for TCP connections to
2642 reduce communications latency, if also supported and enabled in GDB.
2644 - Support for the sparc64-linux-gnu target is now included in
2647 - The amd64-linux build of gdbserver now supports debugging both
2648 32-bit and 64-bit programs.
2650 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2651 now support hardware watchpoints, and will use them automatically
2656 GDB now has support for scripting using Python. Whether this is
2657 available is determined at configure time.
2659 New GDB commands can now be written in Python.
2661 * Ada tasking support
2663 Ada tasks can now be inspected in GDB. The following commands have
2667 Print the list of Ada tasks.
2669 Print detailed information about task number N.
2671 Print the task number of the current task.
2673 Switch the context of debugging to task number N.
2675 * Support for user-defined prefixed commands. The "define" command can
2676 add new commands to existing prefixes, e.g. "target".
2678 * Multi-inferior, multi-process debugging.
2680 GDB now has generalized support for multi-inferior debugging. See
2681 "Debugging Multiple Inferiors" in the manual for more information.
2682 Although availability still depends on target support, the command
2683 set is more uniform now. The GNU/Linux specific multi-forks support
2684 has been migrated to this new framework. This implied some user
2685 visible changes; see "New commands" and also "Removed commands"
2688 * Target descriptions can now describe the target OS ABI. See the
2689 "Target Description Format" section in the user manual for more
2692 * Target descriptions can now describe "compatible" architectures
2693 to indicate that the target can execute applications for a different
2694 architecture in addition to those for the main target architecture.
2695 See the "Target Description Format" section in the user manual for
2698 * Multi-architecture debugging.
2700 GDB now includes general supports for debugging applications on
2701 hybrid systems that use more than one single processor architecture
2702 at the same time. Each such hybrid architecture still requires
2703 specific support to be added. The only hybrid architecture supported
2704 in this version of GDB is the Cell Broadband Engine.
2706 * GDB now supports integrated debugging of Cell/B.E. applications that
2707 use both the PPU and SPU architectures. To enable support for hybrid
2708 Cell/B.E. debugging, you need to configure GDB to support both the
2709 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2710 --enable-targets configure option.
2712 * Non-stop mode debugging.
2714 For some targets, GDB now supports an optional mode of operation in
2715 which you can examine stopped threads while other threads continue
2716 to execute freely. This is referred to as non-stop mode, with the
2717 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2718 section in the user manual for more information.
2720 To be able to support remote non-stop debugging, a remote stub needs
2721 to implement the non-stop mode remote protocol extensions, as
2722 described in the "Remote Non-Stop" section of the user manual. The
2723 GDB remote stub, gdbserver, has been adjusted to support these
2724 extensions on linux targets.
2726 * New commands (for set/show, see "New options" below)
2728 catch syscall [NAME(S) | NUMBER(S)]
2729 Catch system calls. Arguments, which should be names of system
2730 calls or their numbers, mean catch only those syscalls. Without
2731 arguments, every syscall will be caught. When the inferior issues
2732 any of the specified syscalls, GDB will stop and announce the system
2733 call, both when it is called and when its call returns. This
2734 feature is currently available with a native GDB running on the
2735 Linux Kernel, under the following architectures: x86, x86_64,
2736 PowerPC and PowerPC64.
2738 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2740 Search memory for a sequence of bytes.
2742 maint set python print-stack
2743 maint show python print-stack
2744 Show a stack trace when an error is encountered in a Python script.
2747 Invoke CODE by passing it to the Python interpreter.
2752 These allow macros to be defined, undefined, and listed
2756 Show operating system information about processes.
2759 List the inferiors currently under GDB's control.
2762 Switch focus to inferior number NUM.
2765 Detach from inferior number NUM.
2768 Kill inferior number NUM.
2772 set spu stop-on-load
2773 show spu stop-on-load
2774 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2776 set spu auto-flush-cache
2777 show spu auto-flush-cache
2778 Control whether to automatically flush the software-managed cache
2779 during Cell/B.E. debugging.
2781 set sh calling-convention
2782 show sh calling-convention
2783 Control the calling convention used when calling SH target functions.
2786 show debug timestamp
2787 Control display of timestamps with GDB debugging output.
2789 set disassemble-next-line
2790 show disassemble-next-line
2791 Control display of disassembled source lines or instructions when
2794 set remote noack-packet
2795 show remote noack-packet
2796 Set/show the use of remote protocol QStartNoAckMode packet. See above
2797 under "New remote packets."
2799 set remote query-attached-packet
2800 show remote query-attached-packet
2801 Control use of remote protocol `qAttached' (query-attached) packet.
2803 set remote read-siginfo-object
2804 show remote read-siginfo-object
2805 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2808 set remote write-siginfo-object
2809 show remote write-siginfo-object
2810 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2813 set remote reverse-continue
2814 show remote reverse-continue
2815 Control use of remote protocol 'bc' (reverse-continue) packet.
2817 set remote reverse-step
2818 show remote reverse-step
2819 Control use of remote protocol 'bs' (reverse-step) packet.
2821 set displaced-stepping
2822 show displaced-stepping
2823 Control displaced stepping mode. Displaced stepping is a way to
2824 single-step over breakpoints without removing them from the debuggee.
2825 Also known as "out-of-line single-stepping".
2828 show debug displaced
2829 Control display of debugging info for displaced stepping.
2831 maint set internal-error
2832 maint show internal-error
2833 Control what GDB does when an internal error is detected.
2835 maint set internal-warning
2836 maint show internal-warning
2837 Control what GDB does when an internal warning is detected.
2842 Use a wrapper program to launch programs for debugging.
2844 set multiple-symbols (all|ask|cancel)
2845 show multiple-symbols
2846 The value of this variable can be changed to adjust the debugger behavior
2847 when an expression or a breakpoint location contains an ambiguous symbol
2848 name (an overloaded function name, for instance).
2850 set breakpoint always-inserted
2851 show breakpoint always-inserted
2852 Keep breakpoints always inserted in the target, as opposed to inserting
2853 them when resuming the target, and removing them when the target stops.
2854 This option can improve debugger performance on slow remote targets.
2856 set arm fallback-mode (arm|thumb|auto)
2857 show arm fallback-mode
2858 set arm force-mode (arm|thumb|auto)
2860 These commands control how ARM GDB determines whether instructions
2861 are ARM or Thumb. The default for both settings is auto, which uses
2862 the current CPSR value for instructions without symbols; previous
2863 versions of GDB behaved as if "set arm fallback-mode arm".
2865 set disable-randomization
2866 show disable-randomization
2867 Standalone programs run with the virtual address space randomization enabled
2868 by default on some platforms. This option keeps the addresses stable across
2869 multiple debugging sessions.
2873 Control whether other threads are stopped or not when some thread hits
2878 Requests that asynchronous execution is enabled in the target, if available.
2879 In this case, it's possible to resume target in the background, and interact
2880 with GDB while the target is running. "show target-async" displays the
2881 current state of asynchronous execution of the target.
2883 set target-wide-charset
2884 show target-wide-charset
2885 The target-wide-charset is the name of the character set that GDB
2886 uses when printing characters whose type is wchar_t.
2888 set tcp auto-retry (on|off)
2890 set tcp connect-timeout
2891 show tcp connect-timeout
2892 These commands allow GDB to retry failed TCP connections to a remote stub
2893 with a specified timeout period; this is useful if the stub is launched
2894 in parallel with GDB but may not be ready to accept connections immediately.
2896 set libthread-db-search-path
2897 show libthread-db-search-path
2898 Control list of directories which GDB will search for appropriate
2901 set schedule-multiple (on|off)
2902 show schedule-multiple
2903 Allow GDB to resume all threads of all processes or only threads of
2904 the current process.
2908 Use more aggressive caching for accesses to the stack. This improves
2909 performance of remote debugging (particularly backtraces) without
2910 affecting correctness.
2912 set interactive-mode (on|off|auto)
2913 show interactive-mode
2914 Control whether GDB runs in interactive mode (on) or not (off).
2915 When in interactive mode, GDB waits for the user to answer all
2916 queries. Otherwise, GDB does not wait and assumes the default
2917 answer. When set to auto (the default), GDB determines which
2918 mode to use based on the stdin settings.
2923 For program forks, this is replaced by the new more generic `info
2924 inferiors' command. To list checkpoints, you can still use the
2925 `info checkpoints' command, which was an alias for the `info forks'
2929 Replaced by the new `inferior' command. To switch between
2930 checkpoints, you can still use the `restart' command, which was an
2931 alias for the `fork' command.
2934 This is removed, since some targets don't have a notion of
2935 processes. To switch between processes, you can still use the
2936 `inferior' command using GDB's own inferior number.
2939 For program forks, this is replaced by the new more generic `kill
2940 inferior' command. To delete a checkpoint, you can still use the
2941 `delete checkpoint' command, which was an alias for the `delete
2945 For program forks, this is replaced by the new more generic `detach
2946 inferior' command. To detach a checkpoint, you can still use the
2947 `detach checkpoint' command, which was an alias for the `detach
2950 * New native configurations
2952 x86/x86_64 Darwin i[34567]86-*-darwin*
2954 x86_64 MinGW x86_64-*-mingw*
2958 Lattice Mico32 lm32-*
2959 x86 DICOS i[34567]86-*-dicos*
2960 x86_64 DICOS x86_64-*-dicos*
2963 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2964 (mingw32ce) debugging.
2970 These commands were actually not implemented on any target.
2972 *** Changes in GDB 6.8
2974 * New native configurations
2976 NetBSD/hppa hppa*-*netbsd*
2977 Xtensa GNU/Linux xtensa*-*-linux*
2981 NetBSD/hppa hppa*-*-netbsd*
2982 Xtensa GNU/Lunux xtensa*-*-linux*
2984 * Change in command line behavior -- corefiles vs. process ids.
2986 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2987 attaching to process NUMBER fails, GDB no longer attempts to open a
2988 core file named NUMBER. Attaching to a program using the -c option
2989 is no longer supported. Instead, use the '-p' or '--pid' options.
2991 * GDB can now be built as a native debugger for debugging Windows x86
2992 (mingw32) Portable Executable (PE) programs.
2994 * Pending breakpoints no longer change their number when their address
2997 * GDB now supports breakpoints with multiple locations,
2998 including breakpoints on C++ constructors, inside C++ templates,
2999 and in inlined functions.
3001 * GDB's ability to debug optimized code has been improved. GDB more
3002 accurately identifies function bodies and lexical blocks that occupy
3003 more than one contiguous range of addresses.
3005 * Target descriptions can now describe registers for PowerPC.
3007 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3008 registers on PowerPC targets.
3010 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3011 targets even when the libthread_db library is not available.
3013 * The GDB remote stub, gdbserver, now supports the new file transfer
3014 commands (remote put, remote get, and remote delete).
3016 * The GDB remote stub, gdbserver, now supports run and attach in
3017 extended-remote mode.
3019 * hppa*64*-*-hpux11* target broken
3020 The debugger is unable to start a program and fails with the following
3021 error: "Error trying to get information about dynamic linker".
3022 The gdb-6.7 release is also affected.
3024 * GDB now supports the --enable-targets= configure option to allow
3025 building a single GDB executable that supports multiple remote
3026 target architectures.
3028 * GDB now supports debugging C and C++ programs which use the
3029 Decimal Floating Point extension. In addition, the PowerPC target
3030 now has a set of pseudo-registers to inspect decimal float values
3031 stored in two consecutive float registers.
3033 * The -break-insert MI command can optionally create pending
3036 * Improved support for debugging Ada
3037 Many improvements to the Ada language support have been made. These
3039 - Better support for Ada2005 interface types
3040 - Improved handling of arrays and slices in general
3041 - Better support for Taft-amendment types
3042 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3044 - Improved command completion in Ada
3047 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3052 set print frame-arguments (all|scalars|none)
3053 show print frame-arguments
3054 The value of this variable can be changed to control which argument
3055 values should be printed by the debugger when displaying a frame.
3060 Transfer files to and from a remote target, and delete remote files.
3067 Transfer files to and from a remote target, and delete remote files.
3069 * New remote packets
3076 Open, close, read, write, and delete files on the remote system.
3079 Attach to an existing process on the remote system, in extended-remote
3083 Run a new process on the remote system, in extended-remote mode.
3085 *** Changes in GDB 6.7
3087 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3088 bfd, libiberty and opcodes, as revealed by static analysis donated by
3089 Coverity, Inc. (http://scan.coverity.com).
3091 * When looking up multiply-defined global symbols, GDB will now prefer the
3092 symbol definition in the current shared library if it was built using the
3093 -Bsymbolic linker option.
3095 * When the Text User Interface (TUI) is not configured, GDB will now
3096 recognize the -tui command-line option and print a message that the TUI
3099 * The GDB remote stub, gdbserver, now has lower overhead for high
3100 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3102 * GDB for MIPS targets now autodetects whether a remote target provides
3103 32-bit or 64-bit register values.
3105 * Support for C++ member pointers has been improved.
3107 * GDB now understands XML target descriptions, which specify the
3108 target's overall architecture. GDB can read a description from
3109 a local file or over the remote serial protocol.
3111 * Vectors of single-byte data use a new integer type which is not
3112 automatically displayed as character or string data.
3114 * The /s format now works with the print command. It displays
3115 arrays of single-byte integers and pointers to single-byte integers
3118 * Target descriptions can now describe target-specific registers,
3119 for architectures which have implemented the support (currently
3120 only ARM, M68K, and MIPS).
3122 * GDB and the GDB remote stub, gdbserver, now support the XScale
3125 * The GDB remote stub, gdbserver, has been updated to support
3126 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3127 has been rewritten to use the standard GDB remote protocol.
3129 * GDB can now step into C++ functions which are called through thunks.
3131 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3133 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3134 layout. It also supports a TextSeg= and DataSeg= response when only
3135 segment base addresses (rather than offsets) are available.
3137 * The /i format now outputs any trailing branch delay slot instructions
3138 immediately following the last instruction within the count specified.
3140 * The GDB remote protocol "T" stop reply packet now supports a
3141 "library" response. Combined with the new "qXfer:libraries:read"
3142 packet, this response allows GDB to debug shared libraries on targets
3143 where the operating system manages the list of loaded libraries (e.g.
3144 Windows and SymbianOS).
3146 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3147 (DLLs) on Windows and Windows CE targets.
3149 * GDB now supports a faster verification that a .debug file matches its binary
3150 according to its build-id signature, if the signature is present.
3156 Enable or disable hardware flow control (RTS/CTS) on the serial port
3157 when debugging using remote targets.
3159 set mem inaccessible-by-default
3160 show mem inaccessible-by-default
3161 If the target supplies a memory map, for instance via the remote
3162 protocol's "qXfer:memory-map:read" packet, setting this variable
3163 prevents GDB from accessing memory outside the memory map. This
3164 is useful for targets with memory mapped registers or which react
3165 badly to accesses of unmapped address space.
3167 set breakpoint auto-hw
3168 show breakpoint auto-hw
3169 If the target supplies a memory map, for instance via the remote
3170 protocol's "qXfer:memory-map:read" packet, setting this variable
3171 lets GDB use hardware breakpoints automatically for memory regions
3172 where it can not use software breakpoints. This covers both the
3173 "break" command and internal breakpoints used for other commands
3174 including "next" and "finish".
3177 catch exception unhandled
3178 Stop the program execution when Ada exceptions are raised.
3181 Stop the program execution when an Ada assertion failed.
3185 Set an alternate system root for target files. This is a more
3186 general version of "set solib-absolute-prefix", which is now
3187 an alias to "set sysroot".
3190 Provide extended SPU facility status information. This set of
3191 commands is available only when debugging the Cell/B.E. SPU
3194 * New native configurations
3196 OpenBSD/sh sh*-*openbsd*
3199 unset tdesc filename
3201 Use the specified local file as an XML target description, and do
3202 not query the target for its built-in description.
3206 OpenBSD/sh sh*-*-openbsd*
3207 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3208 Toshiba Media Processor mep-elf
3210 * New remote packets
3213 Ignore the specified signals; pass them directly to the debugged program
3214 without stopping other threads or reporting them to GDB.
3216 qXfer:features:read:
3217 Read an XML target description from the target, which describes its
3222 Read or write contents of an spufs file on the target system. These
3223 packets are available only on the Cell/B.E. SPU architecture.
3225 qXfer:libraries:read:
3226 Report the loaded shared libraries. Combined with new "T" packet
3227 response, this packet allows GDB to debug shared libraries on
3228 targets where the operating system manages the list of loaded
3229 libraries (e.g. Windows and SymbianOS).
3233 Support for these obsolete configurations has been removed.
3241 i[34567]86-*-lynxos*
3242 i[34567]86-*-netware*
3243 i[34567]86-*-sco3.2v5*
3244 i[34567]86-*-sco3.2v4*
3246 i[34567]86-*-sysv4.2*
3249 i[34567]86-*-unixware2*
3250 i[34567]86-*-unixware*
3259 * Other removed features
3266 Various m68k-only ROM monitors.
3273 Various Renesas ROM monitors and debugging interfaces for SH and
3278 Support for a Macraigor serial interface to on-chip debugging.
3279 GDB does not directly support the newer parallel or USB
3284 A debug information format. The predecessor to DWARF 2 and
3285 DWARF 3, which are still supported.
3287 Support for the HP aCC compiler on HP-UX/PA-RISC
3289 SOM-encapsulated symbolic debugging information, automatic
3290 invocation of pxdb, and the aCC custom C++ ABI. This does not
3291 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3292 with aCC can still be debugged on an assembly level.
3294 MIPS ".pdr" sections
3296 A MIPS-specific format used to describe stack frame layout
3297 in debugging information.
3301 GDB could work with an older version of Guile to debug
3302 the interpreter and Scheme programs running in it.
3304 set mips stack-arg-size
3305 set mips saved-gpreg-size
3307 Use "set mips abi" to control parameter passing for MIPS.
3309 *** Changes in GDB 6.6
3314 Cell Broadband Engine SPU spu-elf
3316 * GDB can now be configured as a cross-debugger targeting native Windows
3317 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3318 running on a Windows system over TCP/IP to debug Windows programs.
3320 * The GDB remote stub, gdbserver, has been updated to support Windows and
3321 Cygwin debugging. Both single-threaded and multi-threaded programs are
3324 * The "set trust-readonly-sections" command works again. This command was
3325 broken in GDB 6.3, 6.4, and 6.5.
3327 * The "load" command now supports writing to flash memory, if the remote
3328 stub provides the required support.
3330 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3331 longer requires symbolic debug information (e.g. DWARF-2).
3336 unset substitute-path
3337 show substitute-path
3338 Manage a list of substitution rules that GDB uses to rewrite the name
3339 of the directories where the sources are located. This can be useful
3340 for instance when the sources were moved to a different location
3341 between compilation and debugging.
3345 Print each CLI command as it is executed. Each command is prefixed with
3346 a number of `+' symbols representing the nesting depth.
3347 The source command now has a `-v' option to enable the same feature.
3351 The ARM Demon monitor support (RDP protocol, "target rdp").
3353 Kernel Object Display, an embedded debugging feature which only worked with
3354 an obsolete version of Cisco IOS.
3356 The 'set download-write-size' and 'show download-write-size' commands.
3358 * New remote packets
3361 Tell a stub about GDB client features, and request remote target features.
3362 The first feature implemented is PacketSize, which allows the target to
3363 specify the size of packets it can handle - to minimize the number of
3364 packets required and improve performance when connected to a remote
3368 Fetch an OS auxilliary vector from the remote stub. This packet is a
3369 more efficient replacement for qPart:auxv:read.
3371 qXfer:memory-map:read:
3372 Fetch a memory map from the remote stub, including information about
3373 RAM, ROM, and flash memory devices.
3378 Erase and program a flash memory device.
3380 * Removed remote packets
3383 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3384 used it, and only gdbserver implemented it.
3386 *** Changes in GDB 6.5
3390 Renesas M32C/M16C m32c-elf
3392 Morpho Technologies ms1 ms1-elf
3396 init-if-undefined Initialize a convenience variable, but
3397 only if it doesn't already have a value.
3399 The following commands are presently only implemented for native GNU/Linux:
3401 checkpoint Save a snapshot of the program state.
3403 restart <n> Return the program state to a
3404 previously saved state.
3406 info checkpoints List currently saved checkpoints.
3408 delete-checkpoint <n> Delete a previously saved checkpoint.
3410 set|show detach-on-fork Tell gdb whether to detach from a newly
3411 forked process, or to keep debugging it.
3413 info forks List forks of the user program that
3414 are available to be debugged.
3416 fork <n> Switch to debugging one of several
3417 forks of the user program that are
3418 available to be debugged.
3420 delete-fork <n> Delete a fork from the list of forks
3421 that are available to be debugged (and
3422 kill the forked process).
3424 detach-fork <n> Delete a fork from the list of forks
3425 that are available to be debugged (and
3426 allow the process to continue).
3430 Morpho Technologies ms2 ms1-elf
3432 * Improved Windows host support
3434 GDB now builds as a cross debugger hosted on i686-mingw32, including
3435 native console support, and remote communications using either
3436 network sockets or serial ports.
3438 * Improved Modula-2 language support
3440 GDB can now print most types in the Modula-2 syntax. This includes:
3441 basic types, set types, record types, enumerated types, range types,
3442 pointer types and ARRAY types. Procedure var parameters are correctly
3443 printed and hexadecimal addresses and character constants are also
3444 written in the Modula-2 syntax. Best results can be obtained by using
3445 GNU Modula-2 together with the -gdwarf-2 command line option.
3449 The ARM rdi-share module.
3451 The Netware NLM debug server.
3453 *** Changes in GDB 6.4
3455 * New native configurations
3457 OpenBSD/arm arm*-*-openbsd*
3458 OpenBSD/mips64 mips64-*-openbsd*
3462 Morpho Technologies ms1 ms1-elf
3464 * New command line options
3466 --batch-silent As for --batch, but totally silent.
3467 --return-child-result The debugger will exist with the same value
3468 the child (debugged) program exited with.
3469 --eval-command COMMAND, -ex COMMAND
3470 Execute a single GDB CLI command. This may be
3471 specified multiple times and in conjunction
3472 with the --command (-x) option.
3474 * Deprecated commands removed
3476 The following commands, that were deprecated in 2000, have been
3480 set|show arm disassembly-flavor set|show arm disassembler
3481 othernames set arm disassembler
3482 set|show remotedebug set|show debug remote
3483 set|show archdebug set|show debug arch
3484 set|show eventdebug set|show debug event
3487 * New BSD user-level threads support
3489 It is now possible to debug programs using the user-level threads
3490 library on OpenBSD and FreeBSD. Currently supported (target)
3493 FreeBSD/amd64 x86_64-*-freebsd*
3494 FreeBSD/i386 i386-*-freebsd*
3495 OpenBSD/i386 i386-*-openbsd*
3497 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3498 are not yet supported.
3500 * New support for Matsushita MN10300 w/sim added
3501 (Work in progress). mn10300-elf.
3503 * REMOVED configurations and files
3505 VxWorks and the XDR protocol *-*-vxworks
3506 Motorola MCORE mcore-*-*
3507 National Semiconductor NS32000 ns32k-*-*
3509 * New "set print array-indexes" command
3511 After turning this setting "on", GDB prints the index of each element
3512 when displaying arrays. The default is "off" to preserve the previous
3515 * VAX floating point support
3517 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3519 * User-defined command support
3521 In addition to using $arg0..$arg9 for argument passing, it is now possible
3522 to use $argc to determine now many arguments have been passed. See the
3523 section on user-defined commands in the user manual for more information.
3525 *** Changes in GDB 6.3:
3527 * New command line option
3529 GDB now accepts -l followed by a number to set the timeout for remote
3532 * GDB works with GCC -feliminate-dwarf2-dups
3534 GDB now supports a more compact representation of DWARF-2 debug
3535 information using DW_FORM_ref_addr references. These are produced
3536 by GCC with the option -feliminate-dwarf2-dups and also by some
3537 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3538 to use -feliminate-dwarf2-dups.
3540 * Internationalization
3542 When supported by the host system, GDB will be built with
3543 internationalization (libintl). The task of marking up the sources is
3544 continued, we're looking forward to our first translation.
3548 Initial support for debugging programs compiled with the GNAT
3549 implementation of the Ada programming language has been integrated
3550 into GDB. In this release, support is limited to expression evaluation.
3552 * New native configurations
3554 GNU/Linux/m32r m32r-*-linux-gnu
3558 GDB's remote protocol now includes support for the 'p' packet. This
3559 packet is used to fetch individual registers from a remote inferior.
3561 * END-OF-LIFE registers[] compatibility module
3563 GDB's internal register infrastructure has been completely rewritten.
3564 The new infrastructure making possible the implementation of key new
3565 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3568 GDB 6.3 will be the last release to include the the registers[]
3569 compatibility module that allowed out-of-date configurations to
3570 continue to work. This change directly impacts the following
3580 powerpc bdm protocol
3582 Unless there is activity to revive these configurations, they will be
3583 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3585 * OBSOLETE configurations and files
3587 Configurations that have been declared obsolete in this release have
3588 been commented out. Unless there is activity to revive these
3589 configurations, the next release of GDB will have their sources
3590 permanently REMOVED.
3599 *** Changes in GDB 6.2.1:
3601 * MIPS `break main; run' gave an heuristic-fence-post warning
3603 When attempting to run even a simple program, a warning about
3604 heuristic-fence-post being hit would be reported. This problem has
3607 * MIPS IRIX 'long double' crashed GDB
3609 When examining a long double variable, GDB would get a segmentation
3610 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3611 IRIX long double values).
3615 A bug in the VAX stack code was causing problems with the "next"
3616 command. This problem has been fixed.
3618 *** Changes in GDB 6.2:
3620 * Fix for ``many threads''
3622 On GNU/Linux systems that use the NPTL threads library, a program
3623 rapidly creating and deleting threads would confuse GDB leading to the
3626 ptrace: No such process.
3627 thread_db_get_info: cannot get thread info: generic error
3629 This problem has been fixed.
3631 * "-async" and "-noasync" options removed.
3633 Support for the broken "-noasync" option has been removed (it caused
3636 * New ``start'' command.
3638 This command runs the program until the begining of the main procedure.
3640 * New BSD Kernel Data Access Library (libkvm) interface
3642 Using ``target kvm'' it is now possible to debug kernel core dumps and
3643 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3644 platforms. Currently supported (native-only) configurations are:
3646 FreeBSD/amd64 x86_64-*-freebsd*
3647 FreeBSD/i386 i?86-*-freebsd*
3648 NetBSD/i386 i?86-*-netbsd*
3649 NetBSD/m68k m68*-*-netbsd*
3650 NetBSD/sparc sparc-*-netbsd*
3651 OpenBSD/amd64 x86_64-*-openbsd*
3652 OpenBSD/i386 i?86-*-openbsd*
3653 OpenBSD/m68k m68*-openbsd*
3654 OpenBSD/sparc sparc-*-openbsd*
3656 * Signal trampoline code overhauled
3658 Many generic problems with GDB's signal handling code have been fixed.
3659 These include: backtraces through non-contiguous stacks; recognition
3660 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3661 call; backtrace through a signal trampoline; step into and out of
3662 signal handlers; and single-stepping in the signal trampoline.
3664 Please note that kernel bugs are a limiting factor here. These
3665 features have been shown to work on an s390 GNU/Linux system that
3666 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3668 * Cygwin support for DWARF 2 added.
3670 * New native configurations
3672 GNU/Linux/hppa hppa*-*-linux*
3673 OpenBSD/hppa hppa*-*-openbsd*
3674 OpenBSD/m68k m68*-*-openbsd*
3675 OpenBSD/m88k m88*-*-openbsd*
3676 OpenBSD/powerpc powerpc-*-openbsd*
3677 NetBSD/vax vax-*-netbsd*
3678 OpenBSD/vax vax-*-openbsd*
3680 * END-OF-LIFE frame compatibility module
3682 GDB's internal frame infrastructure has been completely rewritten.
3683 The new infrastructure making it possible to support key new features
3684 including DWARF 2 Call Frame Information. To aid in the task of
3685 migrating old configurations to this new infrastructure, a
3686 compatibility module, that allowed old configurations to continue to
3687 work, was also included.
3689 GDB 6.2 will be the last release to include this frame compatibility
3690 module. This change directly impacts the following configurations:
3700 Unless there is activity to revive these configurations, they will be
3701 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3703 * REMOVED configurations and files
3705 Sun 3, running SunOS 3 m68*-*-sunos3*
3706 Sun 3, running SunOS 4 m68*-*-sunos4*
3707 Sun 2, running SunOS 3 m68000-*-sunos3*
3708 Sun 2, running SunOS 4 m68000-*-sunos4*
3709 Motorola 680x0 running LynxOS m68*-*-lynxos*
3710 AT&T 3b1/Unix pc m68*-att-*
3711 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3712 decstation mips-dec-* mips-little-*
3713 riscos mips-*-riscos* mips-*-sysv*
3714 sonymips mips-sony-*
3715 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3717 *** Changes in GDB 6.1.1:
3719 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3721 The TUI (Text-mode User Interface) is now built as part of a default
3722 GDB configuration. It is enabled by either selecting the TUI with the
3723 command line option "-i=tui" or by running the separate "gdbtui"
3724 program. For more information on the TUI, see the manual "Debugging
3727 * Pending breakpoint support (also included in GDB 6.1)
3729 Support has been added to allow you to specify breakpoints in shared
3730 libraries that have not yet been loaded. If a breakpoint location
3731 cannot be found, and the "breakpoint pending" option is set to auto,
3732 GDB queries you if you wish to make the breakpoint pending on a future
3733 shared-library load. If and when GDB resolves the breakpoint symbol,
3734 the pending breakpoint is removed as one or more regular breakpoints
3737 Pending breakpoints are very useful for GCJ Java debugging.
3739 * Fixed ISO-C build problems
3741 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3742 non ISO-C code that stopped them being built using a more strict ISO-C
3743 compiler (e.g., IBM's C compiler).
3745 * Fixed build problem on IRIX 5
3747 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3748 wasn't able to compile compile on an IRIX 5 system.
3750 * Added execute permission to gdb/gdbserver/configure
3752 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3753 permission. This bug would cause configure to fail on a number of
3754 systems (Solaris, IRIX). Ref: server/519.
3756 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3758 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3759 has been updated to use constant array sizes.
3761 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3763 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3764 its generated DWARF Call Frame Info. This encoding was causing GDB to
3765 panic, that panic has been fixed. Ref: gdb/1628.
3767 * Fixed a problem when examining parameters in shared library code.
3769 When examining parameters in optimized shared library code generated
3770 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3771 not available''. GDB now correctly displays the variable's value.
3773 *** Changes in GDB 6.1:
3775 * Removed --with-mmalloc
3777 Support for the mmalloc memory manager has been removed, as it
3778 conflicted with the internal gdb byte cache.
3780 * Changes in AMD64 configurations
3782 The AMD64 target now includes the %cs and %ss registers. As a result
3783 the AMD64 remote protocol has changed; this affects the floating-point
3784 and SSE registers. If you rely on those registers for your debugging,
3785 you should upgrade gdbserver on the remote side.
3787 * Revised SPARC target
3789 The SPARC target has been completely revised, incorporating the
3790 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3791 support for LynxOS and SunOS 4 has been dropped. Calling functions
3792 from within GDB on operating systems with a non-executable stack
3793 (Solaris, OpenBSD) now works.
3797 GDB has a new C++ demangler which does a better job on the mangled
3798 names generated by current versions of g++. It also runs faster, so
3799 with this and other changes gdb should now start faster on large C++
3802 * DWARF 2 Location Expressions
3804 GDB support for location expressions has been extended to support function
3805 arguments and frame bases. Older versions of GDB could crash when they
3808 * C++ nested types and namespaces
3810 GDB's support for nested types and namespaces in C++ has been
3811 improved, especially if you use the DWARF 2 debugging format. (This
3812 is the default for recent versions of GCC on most platforms.)
3813 Specifically, if you have a class "Inner" defined within a class or
3814 namespace "Outer", then GDB realizes that the class's name is
3815 "Outer::Inner", not simply "Inner". This should greatly reduce the
3816 frequency of complaints about not finding RTTI symbols. In addition,
3817 if you are stopped at inside of a function defined within a namespace,
3818 GDB modifies its name lookup accordingly.
3820 * New native configurations
3822 NetBSD/amd64 x86_64-*-netbsd*
3823 OpenBSD/amd64 x86_64-*-openbsd*
3824 OpenBSD/alpha alpha*-*-openbsd*
3825 OpenBSD/sparc sparc-*-openbsd*
3826 OpenBSD/sparc64 sparc64-*-openbsd*
3828 * New debugging protocols
3830 M32R with SDI protocol m32r-*-elf*
3832 * "set prompt-escape-char" command deleted.
3834 The command "set prompt-escape-char" has been deleted. This command,
3835 and its very obscure effet on GDB's prompt, was never documented,
3836 tested, nor mentioned in the NEWS file.
3838 * OBSOLETE configurations and files
3840 Configurations that have been declared obsolete in this release have
3841 been commented out. Unless there is activity to revive these
3842 configurations, the next release of GDB will have their sources
3843 permanently REMOVED.
3845 Sun 3, running SunOS 3 m68*-*-sunos3*
3846 Sun 3, running SunOS 4 m68*-*-sunos4*
3847 Sun 2, running SunOS 3 m68000-*-sunos3*
3848 Sun 2, running SunOS 4 m68000-*-sunos4*
3849 Motorola 680x0 running LynxOS m68*-*-lynxos*
3850 AT&T 3b1/Unix pc m68*-att-*
3851 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3852 decstation mips-dec-* mips-little-*
3853 riscos mips-*-riscos* mips-*-sysv*
3854 sonymips mips-sony-*
3855 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3857 * REMOVED configurations and files
3859 SGI Irix-4.x mips-sgi-irix4 or iris4
3860 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3861 Z8000 simulator z8k-zilog-none or z8ksim
3862 Matsushita MN10200 w/simulator mn10200-*-*
3863 H8/500 simulator h8500-hitachi-hms or h8500hms
3864 HP/PA running BSD hppa*-*-bsd*
3865 HP/PA running OSF/1 hppa*-*-osf*
3866 HP/PA Pro target hppa*-*-pro*
3867 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3868 386BSD i[3456]86-*-bsd*
3869 Sequent family i[3456]86-sequent-sysv4*
3870 i[3456]86-sequent-sysv*
3871 i[3456]86-sequent-bsd*
3872 SPARC running LynxOS sparc-*-lynxos*
3873 SPARC running SunOS 4 sparc-*-sunos4*
3874 Tsqware Sparclet sparclet-*-*
3875 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3877 *** Changes in GDB 6.0:
3881 Support for debugging the Objective-C programming language has been
3882 integrated into GDB.
3884 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3886 DWARF 2's Call Frame Information makes available compiler generated
3887 information that more exactly describes the program's run-time stack.
3888 By using this information, GDB is able to provide more robust stack
3891 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3892 have been updated to use a new backtrace mechanism which includes
3893 DWARF 2 CFI support.
3897 GDB's remote protocol has been extended to include support for hosted
3898 file I/O (where the remote target uses GDB's file system). See GDB's
3899 remote protocol documentation for details.
3901 * All targets using the new architecture framework.
3903 All of GDB's targets have been updated to use the new internal
3904 architecture framework. The way is now open for future GDB releases
3905 to include cross-architecture native debugging support (i386 on amd64,
3908 * GNU/Linux's Thread Local Storage (TLS)
3910 GDB now includes support for for the GNU/Linux implementation of
3911 per-thread variables.
3913 * GNU/Linux's Native POSIX Thread Library (NPTL)
3915 GDB's thread code has been updated to work with either the new
3916 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3918 * Separate debug info.
3920 GDB, in conjunction with BINUTILS, now supports a mechanism for
3921 automatically loading debug information from a separate file. Instead
3922 of shipping full debug and non-debug versions of system libraries,
3923 system integrators can now instead ship just the stripped libraries
3924 and optional debug files.
3926 * DWARF 2 Location Expressions
3928 DWARF 2 Location Expressions allow the compiler to more completely
3929 describe the location of variables (even in optimized code) to the
3932 GDB now includes preliminary support for location expressions (support
3933 for DW_OP_piece is still missing).
3937 A number of long standing bugs that caused GDB to die while starting a
3938 Java application have been fixed. GDB's Java support is now
3939 considered "useable".
3941 * GNU/Linux support for fork, vfork, and exec.
3943 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3944 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3947 * GDB supports logging output to a file
3949 There are two new commands, "set logging" and "show logging", which can be
3950 used to capture GDB's output to a file.
3952 * The meaning of "detach" has changed for gdbserver
3954 The "detach" command will now resume the application, as documented. To
3955 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3958 * d10v, m68hc11 `regs' command deprecated
3960 The `info registers' command has been updated so that it displays the
3961 registers using a format identical to the old `regs' command.
3965 A new command, "maint set profile on/off", has been added. This command can
3966 be used to enable or disable profiling while running GDB, to profile a
3967 session or a set of commands. In addition there is a new configure switch,
3968 "--enable-profiling", which will cause GDB to be compiled with profiling
3969 data, for more informative profiling results.
3971 * Default MI syntax changed to "mi2".
3973 The default MI (machine interface) syntax, enabled by the command line
3974 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3975 "mi1", can be enabled by specifying the option "-i=mi1".
3977 Support for the original "mi0" syntax (included in GDB 5.0) has been
3980 Fix for gdb/192: removed extraneous space when displaying frame level.
3981 Fix for gdb/672: update changelist is now output in mi list format.
3982 Fix for gdb/702: a -var-assign that updates the value now shows up
3983 in a subsequent -var-update.
3985 * New native configurations.
3987 FreeBSD/amd64 x86_64-*-freebsd*
3989 * Multi-arched targets.
3991 HP/PA HPUX11 hppa*-*-hpux*
3992 Renesas M32R/D w/simulator m32r-*-elf*
3994 * OBSOLETE configurations and files
3996 Configurations that have been declared obsolete in this release have
3997 been commented out. Unless there is activity to revive these
3998 configurations, the next release of GDB will have their sources
3999 permanently REMOVED.
4001 Z8000 simulator z8k-zilog-none or z8ksim
4002 Matsushita MN10200 w/simulator mn10200-*-*
4003 H8/500 simulator h8500-hitachi-hms or h8500hms
4004 HP/PA running BSD hppa*-*-bsd*
4005 HP/PA running OSF/1 hppa*-*-osf*
4006 HP/PA Pro target hppa*-*-pro*
4007 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4008 Sequent family i[3456]86-sequent-sysv4*
4009 i[3456]86-sequent-sysv*
4010 i[3456]86-sequent-bsd*
4011 Tsqware Sparclet sparclet-*-*
4012 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4014 * REMOVED configurations and files
4017 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4018 IBM AIX PS/2 i[3456]86-*-aix
4019 i386 running Mach 3.0 i[3456]86-*-mach3*
4020 i386 running Mach i[3456]86-*-mach*
4021 i386 running OSF/1 i[3456]86-*osf1mk*
4022 HP/Apollo 68k Family m68*-apollo*-sysv*,
4024 m68*-hp-bsd*, m68*-hp-hpux*
4025 Argonaut Risc Chip (ARC) arc-*-*
4026 Mitsubishi D30V d30v-*-*
4027 Fujitsu FR30 fr30-*-elf*
4028 OS/9000 i[34]86-*-os9k
4029 I960 with MON960 i960-*-coff
4031 * MIPS $fp behavior changed
4033 The convenience variable $fp, for the MIPS, now consistently returns
4034 the address of the current frame's base. Previously, depending on the
4035 context, $fp could refer to either $sp or the current frame's base
4036 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4037 The GNU Source-Level Debugger''.
4039 *** Changes in GDB 5.3:
4041 * GNU/Linux shared library multi-threaded performance improved.
4043 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4044 `/proc', in preference to `ptrace' for memory reads. This may result
4045 in an improvement in the start-up time of multi-threaded, shared
4046 library applications when run under GDB. One GDB user writes: ``loads
4047 shared libs like mad''.
4049 * ``gdbserver'' now supports multi-threaded applications on some targets
4051 Support for debugging multi-threaded applications which use
4052 the GNU/Linux LinuxThreads package has been added for
4053 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4054 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4056 * GDB now supports C/C++ preprocessor macros.
4058 GDB now expands preprocessor macro invocations in C/C++ expressions,
4059 and provides various commands for showing macro definitions and how
4062 The new command `macro expand EXPRESSION' expands any macro
4063 invocations in expression, and shows the result.
4065 The new command `show macro MACRO-NAME' shows the definition of the
4066 macro named MACRO-NAME, and where it was defined.
4068 Most compilers don't include information about macros in the debugging
4069 information by default. In GCC 3.1, for example, you need to compile
4070 your program with the options `-gdwarf-2 -g3'. If the macro
4071 information is present in the executable, GDB will read it.
4073 * Multi-arched targets.
4075 DEC Alpha (partial) alpha*-*-*
4076 DEC VAX (partial) vax-*-*
4078 National Semiconductor NS32000 (partial) ns32k-*-*
4079 Motorola 68000 (partial) m68k-*-*
4080 Motorola MCORE mcore-*-*
4084 Fujitsu FRV architecture added by Red Hat frv*-*-*
4087 * New native configurations
4089 Alpha NetBSD alpha*-*-netbsd*
4090 SH NetBSD sh*-*-netbsdelf*
4091 MIPS NetBSD mips*-*-netbsd*
4092 UltraSPARC NetBSD sparc64-*-netbsd*
4094 * OBSOLETE configurations and files
4096 Configurations that have been declared obsolete in this release have
4097 been commented out. Unless there is activity to revive these
4098 configurations, the next release of GDB will have their sources
4099 permanently REMOVED.
4101 Mitsubishi D30V d30v-*-*
4102 OS/9000 i[34]86-*-os9k
4103 IBM AIX PS/2 i[3456]86-*-aix
4104 Fujitsu FR30 fr30-*-elf*
4105 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4106 Argonaut Risc Chip (ARC) arc-*-*
4107 i386 running Mach 3.0 i[3456]86-*-mach3*
4108 i386 running Mach i[3456]86-*-mach*
4109 i386 running OSF/1 i[3456]86-*osf1mk*
4110 HP/Apollo 68k Family m68*-apollo*-sysv*,
4112 m68*-hp-bsd*, m68*-hp-hpux*
4113 I960 with MON960 i960-*-coff
4115 * OBSOLETE languages
4117 CHILL, a Pascal like language used by telecommunications companies.
4119 * REMOVED configurations and files
4121 AMD 29k family via UDI a29k-amd-udi, udi29k
4122 A29K VxWorks a29k-*-vxworks
4123 AMD 29000 embedded, using EBMON a29k-none-none
4124 AMD 29000 embedded with COFF a29k-none-coff
4125 AMD 29000 embedded with a.out a29k-none-aout
4127 testsuite/gdb.hp/gdb.threads-hp/ directory
4129 * New command "set max-user-call-depth <nnn>"
4131 This command allows the user to limit the call depth of user-defined
4132 commands. The default is 1024.
4134 * Changes in FreeBSD/i386 native debugging.
4136 Support for the "generate-core-file" has been added.
4138 * New commands "dump", "append", and "restore".
4140 These commands allow data to be copied from target memory
4141 to a bfd-format or binary file (dump and append), and back
4142 from a file into memory (restore).
4144 * Improved "next/step" support on multi-processor Alpha Tru64.
4146 The previous single-step mechanism could cause unpredictable problems,
4147 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4148 of a software single-step mechanism prevents this.
4150 *** Changes in GDB 5.2.1:
4158 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4159 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4160 Fix, by Joel Brobecker imported from mainline.
4162 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4163 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4164 Fix, by Fred Fish, imported from mainline.
4166 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4167 Surprisingly enough, it works now.
4168 By Michal Ludvig, imported from mainline.
4170 i386 hardware watchpoint support:
4171 avoid misses on second run for some targets.
4172 By Pierre Muller, imported from mainline.
4174 *** Changes in GDB 5.2:
4176 * New command "set trust-readonly-sections on[off]".
4178 This command is a hint that tells gdb that read-only sections
4179 really are read-only (ie. that their contents will not change).
4180 In this mode, gdb will go to the object file rather than the
4181 target to read memory from read-only sections (such as ".text").
4182 This can be a significant performance improvement on some
4183 (notably embedded) targets.
4185 * New command "generate-core-file" (or "gcore").
4187 This new gdb command allows the user to drop a core file of the child
4188 process state at any time. So far it's been implemented only for
4189 GNU/Linux and Solaris, but should be relatively easily ported to other
4190 hosts. Argument is core file name (defaults to core.<pid>).
4192 * New command line option
4194 GDB now accepts --pid or -p followed by a process id.
4196 * Change in command line behavior -- corefiles vs. process ids.
4198 There is a subtle behavior in the way in which GDB handles
4199 command line arguments. The first non-flag argument is always
4200 a program to debug, but the second non-flag argument may either
4201 be a corefile or a process id. Previously, GDB would attempt to
4202 open the second argument as a corefile, and if that failed, would
4203 issue a superfluous error message and then attempt to attach it as
4204 a process. Now, if the second argument begins with a non-digit,
4205 it will be treated as a corefile. If it begins with a digit,
4206 GDB will attempt to attach it as a process, and if no such process
4207 is found, will then attempt to open it as a corefile.
4209 * Changes in ARM configurations.
4211 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4212 configuration is fully multi-arch.
4214 * New native configurations
4216 ARM NetBSD arm*-*-netbsd*
4217 x86 OpenBSD i[3456]86-*-openbsd*
4218 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4219 Sparc64 running FreeBSD sparc64-*-freebsd*
4223 Sanyo XStormy16 xstormy16-elf
4225 * OBSOLETE configurations and files
4227 Configurations that have been declared obsolete in this release have
4228 been commented out. Unless there is activity to revive these
4229 configurations, the next release of GDB will have their sources
4230 permanently REMOVED.
4232 AMD 29k family via UDI a29k-amd-udi, udi29k
4233 A29K VxWorks a29k-*-vxworks
4234 AMD 29000 embedded, using EBMON a29k-none-none
4235 AMD 29000 embedded with COFF a29k-none-coff
4236 AMD 29000 embedded with a.out a29k-none-aout
4238 testsuite/gdb.hp/gdb.threads-hp/ directory
4240 * REMOVED configurations and files
4242 TI TMS320C80 tic80-*-*
4244 PowerPC Solaris powerpcle-*-solaris*
4245 PowerPC Windows NT powerpcle-*-cygwin32
4246 PowerPC Netware powerpc-*-netware*
4247 Harris/CXUX m88k m88*-harris-cxux*
4248 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4249 ns32k-utek-sysv* ns32k-utek-*
4250 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4251 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4252 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4253 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4254 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4256 * Changes to command line processing
4258 The new `--args' feature can be used to specify command-line arguments
4259 for the inferior from gdb's command line.
4261 * Changes to key bindings
4263 There is a new `operate-and-get-next' function bound to `C-o'.
4265 *** Changes in GDB 5.1.1
4267 Fix compile problem on DJGPP.
4269 Fix a problem with floating-point registers on the i386 being
4272 Fix to stop GDB crashing on .debug_str debug info.
4274 Numerous documentation fixes.
4276 Numerous testsuite fixes.
4278 *** Changes in GDB 5.1:
4280 * New native configurations
4282 Alpha FreeBSD alpha*-*-freebsd*
4283 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4284 MIPS GNU/Linux mips*-*-linux*
4285 MIPS SGI Irix 6.x mips*-sgi-irix6*
4286 ia64 AIX ia64-*-aix*
4287 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4291 Motorola 68HC11 and 68HC12 m68hc11-elf
4293 UltraSparc running GNU/Linux sparc64-*-linux*
4295 * OBSOLETE configurations and files
4297 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4298 Harris/CXUX m88k m88*-harris-cxux*
4299 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4300 ns32k-utek-sysv* ns32k-utek-*
4301 TI TMS320C80 tic80-*-*
4303 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4304 PowerPC Solaris powerpcle-*-solaris*
4305 PowerPC Windows NT powerpcle-*-cygwin32
4306 PowerPC Netware powerpc-*-netware*
4307 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4308 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4309 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4310 Apple Macintosh (MPW) host N/A
4312 stuff.c (Program to stuff files into a specially prepared space in kdb)
4313 kdb-start.c (Main loop for the standalone kernel debugger)
4315 Configurations that have been declared obsolete in this release have
4316 been commented out. Unless there is activity to revive these
4317 configurations, the next release of GDB will have their sources
4318 permanently REMOVED.
4320 * REMOVED configurations and files
4322 Altos 3068 m68*-altos-*
4323 Convex c1-*-*, c2-*-*
4325 ARM RISCix arm-*-* (as host)
4329 * GDB has been converted to ISO C.
4331 GDB's source code has been converted to ISO C. In particular, the
4332 sources are fully protoized, and rely on standard headers being
4337 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4339 * The MI enabled by default.
4341 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4342 revised and enabled by default. Packages which use GDB as a debugging
4343 engine behind a UI or another front end are encouraged to switch to
4344 using the GDB/MI interface, instead of the old annotations interface
4345 which is now deprecated.
4347 * Support for debugging Pascal programs.
4349 GDB now includes support for debugging Pascal programs. The following
4350 main features are supported:
4352 - Pascal-specific data types such as sets;
4354 - automatic recognition of Pascal sources based on file-name
4357 - Pascal-style display of data types, variables, and functions;
4359 - a Pascal expression parser.
4361 However, some important features are not yet supported.
4363 - Pascal string operations are not supported at all;
4365 - there are some problems with boolean types;
4367 - Pascal type hexadecimal constants are not supported
4368 because they conflict with the internal variables format;
4370 - support for Pascal objects and classes is not full yet;
4372 - unlike Pascal, GDB is case-sensitive for symbol names.
4374 * Changes in completion.
4376 Commands such as `shell', `run' and `set args', which pass arguments
4377 to inferior programs, now complete on file names, similar to what
4378 users expect at the shell prompt.
4380 Commands which accept locations, such as `disassemble', `print',
4381 `breakpoint', `until', etc. now complete on filenames as well as
4382 program symbols. Thus, if you type "break foob TAB", and the source
4383 files linked into the programs include `foobar.c', that file name will
4384 be one of the candidates for completion. However, file names are not
4385 considered for completion after you typed a colon that delimits a file
4386 name from a name of a function in that file, as in "break foo.c:bar".
4388 `set demangle-style' completes on available demangling styles.
4390 * New platform-independent commands:
4392 It is now possible to define a post-hook for a command as well as a
4393 hook that runs before the command. For more details, see the
4394 documentation of `hookpost' in the GDB manual.
4396 * Changes in GNU/Linux native debugging.
4398 Support for debugging multi-threaded programs has been completely
4399 revised for all platforms except m68k and sparc. You can now debug as
4400 many threads as your system allows you to have.
4402 Attach/detach is supported for multi-threaded programs.
4404 Support for SSE registers was added for x86. This doesn't work for
4405 multi-threaded programs though.
4407 * Changes in MIPS configurations.
4409 Multi-arch support is enabled for all MIPS configurations.
4411 GDB can now be built as native debugger on SGI Irix 6.x systems for
4412 debugging n32 executables. (Debugging 64-bit executables is not yet
4415 * Unified support for hardware watchpoints in all x86 configurations.
4417 Most (if not all) native x86 configurations support hardware-assisted
4418 breakpoints and watchpoints in a unified manner. This support
4419 implements debug register sharing between watchpoints, which allows to
4420 put a virtually infinite number of watchpoints on the same address,
4421 and also supports watching regions up to 16 bytes with several debug
4424 The new maintenance command `maintenance show-debug-regs' toggles
4425 debugging print-outs in functions that insert, remove, and test
4426 watchpoints and hardware breakpoints.
4428 * Changes in the DJGPP native configuration.
4430 New command ``info dos sysinfo'' displays assorted information about
4431 the CPU, OS, memory, and DPMI server.
4433 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4434 display information about segment descriptors stored in GDT, LDT, and
4437 New commands ``info dos pde'' and ``info dos pte'' display entries
4438 from Page Directory and Page Tables (for now works with CWSDPMI only).
4439 New command ``info dos address-pte'' displays the Page Table entry for
4440 a given linear address.
4442 GDB can now pass command lines longer than 126 characters to the
4443 program being debugged (requires an update to the libdbg.a library
4444 which is part of the DJGPP development kit).
4446 DWARF2 debug info is now supported.
4448 It is now possible to `step' and `next' through calls to `longjmp'.
4450 * Changes in documentation.
4452 All GDB documentation was converted to GFDL, the GNU Free
4453 Documentation License.
4455 Tracepoints-related commands are now fully documented in the GDB
4458 TUI, the Text-mode User Interface, is now documented in the manual.
4460 Tracepoints-related commands are now fully documented in the GDB
4463 The "GDB Internals" manual now has an index. It also includes
4464 documentation of `ui_out' functions, GDB coding standards, x86
4465 hardware watchpoints, and memory region attributes.
4467 * GDB's version number moved to ``version.in''
4469 The Makefile variable VERSION has been replaced by the file
4470 ``version.in''. People creating GDB distributions should update the
4471 contents of this file.
4475 GUD support is now a standard part of the EMACS distribution.
4477 *** Changes in GDB 5.0:
4479 * Improved support for debugging FP programs on x86 targets
4481 Unified and much-improved support for debugging floating-point
4482 programs on all x86 targets. In particular, ``info float'' now
4483 displays the FP registers in the same format on all x86 targets, with
4484 greater level of detail.
4486 * Improvements and bugfixes in hardware-assisted watchpoints
4488 It is now possible to watch array elements, struct members, and
4489 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4490 on x86 targets no longer erroneously trigger when the address is
4493 * Improvements in the native DJGPP version of GDB
4495 The distribution now includes all the scripts and auxiliary files
4496 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4497 machines ``out of the box''.
4499 The DJGPP version can now debug programs that use signals. It is
4500 possible to catch signals that happened in the debuggee, deliver
4501 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4502 would kill the program being debugged.) Programs that hook hardware
4503 interrupts (keyboard, timer, etc.) can also be debugged.
4505 It is now possible to debug DJGPP programs that redirect their
4506 standard handles or switch them to raw (as opposed to cooked) mode, or
4507 even close them. The command ``run < foo > bar'' works as expected,
4508 and ``info terminal'' reports useful information about the debuggee's
4509 terminal, including raw/cooked mode, redirection, etc.
4511 The DJGPP version now uses termios functions for console I/O, which
4512 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4515 DOS-style file names with drive letters are now fully supported by
4518 It is now possible to debug DJGPP programs that switch their working
4519 directory. It is also possible to rerun the debuggee any number of
4520 times without restarting GDB; thus, you can use the same setup,
4521 breakpoints, etc. for many debugging sessions.
4523 * New native configurations
4525 ARM GNU/Linux arm*-*-linux*
4526 PowerPC GNU/Linux powerpc-*-linux*
4530 Motorola MCore mcore-*-*
4531 x86 VxWorks i[3456]86-*-vxworks*
4532 PowerPC VxWorks powerpc-*-vxworks*
4533 TI TMS320C80 tic80-*-*
4535 * OBSOLETE configurations
4537 Altos 3068 m68*-altos-*
4538 Convex c1-*-*, c2-*-*
4540 ARM RISCix arm-*-* (as host)
4543 Configurations that have been declared obsolete will be commented out,
4544 but the code will be left in place. If there is no activity to revive
4545 these configurations before the next release of GDB, the sources will
4546 be permanently REMOVED.
4548 * Gould support removed
4550 Support for the Gould PowerNode and NP1 has been removed.
4552 * New features for SVR4
4554 On SVR4 native platforms (such as Solaris), if you attach to a process
4555 without first loading a symbol file, GDB will now attempt to locate and
4556 load symbols from the running process's executable file.
4558 * Many C++ enhancements
4560 C++ support has been greatly improved. Overload resolution now works properly
4561 in almost all cases. RTTI support is on the way.
4563 * Remote targets can connect to a sub-program
4565 A popen(3) style serial-device has been added. This device starts a
4566 sub-process (such as a stand-alone simulator) and then communicates
4567 with that. The sub-program to run is specified using the syntax
4568 ``|<program> <args>'' vis:
4570 (gdb) set remotedebug 1
4571 (gdb) target extended-remote |mn10300-elf-sim program-args
4573 * MIPS 64 remote protocol
4575 A long standing bug in the mips64 remote protocol where by GDB
4576 expected certain 32 bit registers (ex SR) to be transfered as 32
4577 instead of 64 bits has been fixed.
4579 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4580 added to provide backward compatibility with older versions of GDB.
4582 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4584 The command ``set remotebinarydownload'' command has been replaced by
4585 ``set remote X-packet''. Other commands in ``set remote'' family
4586 include ``set remote P-packet''.
4588 * Breakpoint commands accept ranges.
4590 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4591 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4592 ``tracepoint passcount'' also accepts a range of tracepoints.
4594 * ``apropos'' command added.
4596 The ``apropos'' command searches through command names and
4597 documentation strings, printing out matches, making it much easier to
4598 try to find a command that does what you are looking for.
4602 A new machine oriented interface (MI) has been added to GDB. This
4603 interface is designed for debug environments running GDB as a separate
4604 process. This is part of the long term libGDB project. See the
4605 "GDB/MI" chapter of the GDB manual for further information. It can be
4606 enabled by configuring with:
4608 .../configure --enable-gdbmi
4610 *** Changes in GDB-4.18:
4612 * New native configurations
4614 HP-UX 10.20 hppa*-*-hpux10.20
4615 HP-UX 11.x hppa*-*-hpux11.0*
4616 M68K GNU/Linux m68*-*-linux*
4620 Fujitsu FR30 fr30-*-elf*
4621 Intel StrongARM strongarm-*-*
4622 Mitsubishi D30V d30v-*-*
4624 * OBSOLETE configurations
4626 Gould PowerNode, NP1 np1-*-*, pn-*-*
4628 Configurations that have been declared obsolete will be commented out,
4629 but the code will be left in place. If there is no activity to revive
4630 these configurations before the next release of GDB, the sources will
4631 be permanently REMOVED.
4635 As a compatibility experiment, GDB's source files buildsym.h and
4636 buildsym.c have been converted to pure standard C, no longer
4637 containing any K&R compatibility code. We believe that all systems in
4638 use today either come with a standard C compiler, or have a GCC port
4639 available. If this is not true, please report the affected
4640 configuration to bug-gdb@gnu.org immediately. See the README file for
4641 information about getting a standard C compiler if you don't have one
4646 GDB now uses readline 2.2.
4648 * set extension-language
4650 You can now control the mapping between filename extensions and source
4651 languages by using the `set extension-language' command. For instance,
4652 you can ask GDB to treat .c files as C++ by saying
4653 set extension-language .c c++
4654 The command `info extensions' lists all of the recognized extensions
4655 and their associated languages.
4657 * Setting processor type for PowerPC and RS/6000
4659 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4660 you can use the `set processor' command to specify what variant of the
4661 PowerPC family you are debugging. The command
4665 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4666 following PowerPC and RS6000 variants:
4668 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4669 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4671 403GC IBM PowerPC 403GC
4672 505 Motorola PowerPC 505
4673 860 Motorola PowerPC 860 or 850
4674 601 Motorola PowerPC 601
4675 602 Motorola PowerPC 602
4676 603 Motorola/IBM PowerPC 603 or 603e
4677 604 Motorola PowerPC 604 or 604e
4678 750 Motorola/IBM PowerPC 750 or 750
4680 At the moment, this command just tells GDB what to name the
4681 special-purpose processor registers. Since almost all the affected
4682 registers are inaccessible to user-level programs, this command is
4683 only useful for remote debugging in its present form.
4687 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4688 more extensive support for HP-UX. Added features include shared
4689 library support, kernel threads and hardware watchpoints for 11.00,
4690 support for HP's ANSI C and C++ compilers, and a compatibility mode
4691 for xdb and dbx commands.
4695 HP's donation includes the new concept of catchpoints, which is a
4696 generalization of the old catch command. On HP-UX, it is now possible
4697 to catch exec, fork, and vfork, as well as library loading.
4699 This means that the existing catch command has changed; its first
4700 argument now specifies the type of catch to be set up. See the
4701 output of "help catch" for a list of catchpoint types.
4703 * Debugging across forks
4705 On HP-UX, you can choose which process to debug when a fork() happens
4710 HP has donated a curses-based terminal user interface (TUI). To get
4711 it, build with --enable-tui. Although this can be enabled for any
4712 configuration, at present it only works for native HP debugging.
4714 * GDB remote protocol additions
4716 A new protocol packet 'X' that writes binary data is now available.
4717 Default behavior is to try 'X', then drop back to 'M' if the stub
4718 fails to respond. The settable variable `remotebinarydownload'
4719 allows explicit control over the use of 'X'.
4721 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4722 full 64-bit address. The command
4724 set remoteaddresssize 32
4726 can be used to revert to the old behaviour. For existing remote stubs
4727 the change should not be noticed, as the additional address information
4730 In order to assist in debugging stubs, you may use the maintenance
4731 command `packet' to send any text string to the stub. For instance,
4733 maint packet heythere
4735 sends the packet "$heythere#<checksum>". Note that it is very easy to
4736 disrupt a debugging session by sending the wrong packet at the wrong
4739 The compare-sections command allows you to compare section data on the
4740 target to what is in the executable file without uploading or
4741 downloading, by comparing CRC checksums.
4743 * Tracing can collect general expressions
4745 You may now collect general expressions at tracepoints. This requires
4746 further additions to the target-side stub; see tracepoint.c and
4747 doc/agentexpr.texi for further details.
4749 * mask-address variable for Mips
4751 For Mips targets, you may control the zeroing of the upper 32 bits of
4752 a 64-bit address by entering `set mask-address on'. This is mainly
4753 of interest to users of embedded R4xxx and R5xxx processors.
4755 * Higher serial baud rates
4757 GDB's serial code now allows you to specify baud rates 57600, 115200,
4758 230400, and 460800 baud. (Note that your host system may not be able
4759 to achieve all of these rates.)
4763 The i960 configuration now includes an initial implementation of a
4764 builtin simulator, contributed by Jim Wilson.
4767 *** Changes in GDB-4.17:
4769 * New native configurations
4771 Alpha GNU/Linux alpha*-*-linux*
4772 Unixware 2.x i[3456]86-unixware2*
4773 Irix 6.x mips*-sgi-irix6*
4774 PowerPC GNU/Linux powerpc-*-linux*
4775 PowerPC Solaris powerpcle-*-solaris*
4776 Sparc GNU/Linux sparc-*-linux*
4777 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4781 Argonaut Risc Chip (ARC) arc-*-*
4782 Hitachi H8/300S h8300*-*-*
4783 Matsushita MN10200 w/simulator mn10200-*-*
4784 Matsushita MN10300 w/simulator mn10300-*-*
4785 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4786 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4787 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4788 Mitsubishi D10V w/simulator d10v-*-*
4789 Mitsubishi M32R/D w/simulator m32r-*-elf*
4790 Tsqware Sparclet sparclet-*-*
4791 NEC V850 w/simulator v850-*-*
4793 * New debugging protocols
4795 ARM with RDI protocol arm*-*-*
4796 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4797 DDB and LSI variants of PMON protocol mips*-*-*
4798 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4799 PowerPC with SDS protocol powerpc{,le}-*-eabi
4800 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4804 All configurations can now understand and use the DWARF 2 debugging
4805 format. The choice is automatic, if the symbol file contains DWARF 2
4810 GDB now includes basic Java language support. This support is
4811 only useful with Java compilers that produce native machine code.
4813 * solib-absolute-prefix and solib-search-path
4815 For SunOS and SVR4 shared libraries, you may now set the prefix for
4816 loading absolute shared library symbol files, and the search path for
4817 locating non-absolute shared library symbol files.
4819 * Live range splitting
4821 GDB can now effectively debug code for which GCC has performed live
4822 range splitting as part of its optimization. See gdb/doc/LRS for
4823 more details on the expected format of the stabs information.
4827 GDB's support for the GNU Hurd, including thread debugging, has been
4828 updated to work with current versions of the Hurd.
4832 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4833 instruction set. ARM GDB automatically detects when Thumb
4834 instructions are in use, and adjusts disassembly and backtracing
4839 GDB's MIPS target configurations now handle the MIP16 16-bit
4844 GDB now includes support for overlays; if an executable has been
4845 linked such that multiple sections are based at the same address, GDB
4846 will decide which section to use for symbolic info. You can choose to
4847 control the decision manually, using overlay commands, or implement
4848 additional target-side support and use "overlay load-target" to bring
4849 in the overlay mapping. Do "help overlay" for more detail.
4853 The command "info symbol <address>" displays information about
4854 the symbol at the specified address.
4858 The standard remote protocol now includes an extension that allows
4859 asynchronous collection and display of trace data. This requires
4860 extensive support in the target-side debugging stub. Tracing mode
4861 includes a new interaction mode in GDB and new commands: see the
4862 file tracepoint.c for more details.
4866 Configurations for embedded MIPS now include a simulator contributed
4867 by Cygnus Solutions. The simulator supports the instruction sets
4868 of most MIPS variants.
4872 Sparc configurations may now include the ERC32 simulator contributed
4873 by the European Space Agency. The simulator is not built into
4874 Sparc targets by default; configure with --enable-sim to include it.
4878 For target configurations that may include multiple variants of a
4879 basic architecture (such as MIPS and SH), you may now set the
4880 architecture explicitly. "set arch" sets, "info arch" lists
4881 the possible architectures.
4883 *** Changes in GDB-4.16:
4885 * New native configurations
4887 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4888 M68K NetBSD m68k-*-netbsd*
4889 PowerPC AIX 4.x powerpc-*-aix*
4890 PowerPC MacOS powerpc-*-macos*
4891 PowerPC Windows NT powerpcle-*-cygwin32
4892 RS/6000 AIX 4.x rs6000-*-aix4*
4896 ARM with RDP protocol arm-*-*
4897 I960 with MON960 i960-*-coff
4898 MIPS VxWorks mips*-*-vxworks*
4899 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4900 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4902 Matra Sparclet sparclet-*-*
4906 The powerpc-eabi configuration now includes the PSIM simulator,
4907 contributed by Andrew Cagney, with assistance from Mike Meissner.
4908 PSIM is a very elaborate model of the PowerPC, including not only
4909 basic instruction set execution, but also details of execution unit
4910 performance and I/O hardware. See sim/ppc/README for more details.
4914 GDB now works with Solaris 2.5.
4916 * Windows 95/NT native
4918 GDB will now work as a native debugger on Windows 95 and Windows NT.
4919 To build it from source, you must use the "gnu-win32" environment,
4920 which uses a DLL to emulate enough of Unix to run the GNU tools.
4921 Further information, binaries, and sources are available at
4922 ftp.cygnus.com, under pub/gnu-win32.
4924 * dont-repeat command
4926 If a user-defined command includes the command `dont-repeat', then the
4927 command will not be repeated if the user just types return. This is
4928 useful if the command is time-consuming to run, so that accidental
4929 extra keystrokes don't run the same command many times.
4931 * Send break instead of ^C
4933 The standard remote protocol now includes an option to send a break
4934 rather than a ^C to the target in order to interrupt it. By default,
4935 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4937 * Remote protocol timeout
4939 The standard remote protocol includes a new variable `remotetimeout'
4940 that allows you to set the number of seconds before GDB gives up trying
4941 to read from the target. The default value is 2.
4943 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4945 By default GDB will automatically keep track of objects as they are
4946 loaded and unloaded by the dynamic linker. By using the command `set
4947 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4948 when shared library events occur, thus allowing you to set breakpoints
4949 in shared libraries which are explicitly loaded by the inferior.
4951 Note this feature does not work on hpux8. On hpux9 you must link
4952 /usr/lib/end.o into your program. This feature should work
4953 automatically on hpux10.
4955 * Irix 5.x hardware watchpoint support
4957 Irix 5 configurations now support the use of hardware watchpoints.
4959 * Mips protocol "SYN garbage limit"
4961 When debugging a Mips target using the `target mips' protocol, you
4962 may set the number of characters that GDB will ignore by setting
4963 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4964 every character. The default value is 1050.
4966 * Recording and replaying remote debug sessions
4968 If you set `remotelogfile' to the name of a file, gdb will write to it
4969 a recording of a remote debug session. This recording may then be
4970 replayed back to gdb using "gdbreplay". See gdbserver/README for
4971 details. This is useful when you have a problem with GDB while doing
4972 remote debugging; you can make a recording of the session and send it
4973 to someone else, who can then recreate the problem.
4975 * Speedups for remote debugging
4977 GDB includes speedups for downloading and stepping MIPS systems using
4978 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4979 and more efficient S-record downloading.
4981 * Memory use reductions and statistics collection
4983 GDB now uses less memory and reports statistics about memory usage.
4984 Try the `maint print statistics' command, for example.
4986 *** Changes in GDB-4.15:
4988 * Psymtabs for XCOFF
4990 The symbol reader for AIX GDB now uses partial symbol tables. This
4991 can greatly improve startup time, especially for large executables.
4993 * Remote targets use caching
4995 Remote targets now use a data cache to speed up communication with the
4996 remote side. The data cache could lead to incorrect results because
4997 it doesn't know about volatile variables, thus making it impossible to
4998 debug targets which use memory mapped I/O devices. `set remotecache
4999 off' turns the the data cache off.
5001 * Remote targets may have threads
5003 The standard remote protocol now includes support for multiple threads
5004 in the target system, using new protocol commands 'H' and 'T'. See
5005 gdb/remote.c for details.
5009 If GDB is configured with `--enable-netrom', then it will include
5010 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5011 acts as though it is a bank of ROM on the target board, but you can
5012 write into it over the network. GDB's support consists only of
5013 support for fast loading into the emulated ROM; to debug, you must use
5014 another protocol, such as standard remote protocol. The usual
5015 sequence is something like
5017 target nrom <netrom-hostname>
5019 target remote <netrom-hostname>:1235
5023 GDB now includes support for the Apple Macintosh, as a host only. It
5024 may be run as either an MPW tool or as a standalone application, and
5025 it can debug through the serial port. All the usual GDB commands are
5026 available, but to the target command, you must supply "serial" as the
5027 device type instead of "/dev/ttyXX". See mpw-README in the main
5028 directory for more information on how to build. The MPW configuration
5029 scripts */mpw-config.in support only a few targets, and only the
5030 mips-idt-ecoff target has been tested.
5034 GDB configuration now uses autoconf. This is not user-visible,
5035 but does simplify configuration and building.
5039 GDB now supports hpux10.
5041 *** Changes in GDB-4.14:
5043 * New native configurations
5045 x86 FreeBSD i[345]86-*-freebsd
5046 x86 NetBSD i[345]86-*-netbsd
5047 NS32k NetBSD ns32k-*-netbsd
5048 Sparc NetBSD sparc-*-netbsd
5052 A29K VxWorks a29k-*-vxworks
5053 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5054 CPU32 EST-300 emulator m68*-*-est*
5055 PowerPC ELF powerpc-*-elf
5058 * Alpha OSF/1 support for procfs
5060 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5061 possible to attach to running processes. As the mounting of the /proc
5062 filesystem is optional on the Alpha, GDB automatically determines
5063 the availability of /proc during startup. This can lead to problems
5064 if /proc is unmounted after GDB has been started.
5066 * Arguments to user-defined commands
5068 User commands may accept up to 10 arguments separated by whitespace.
5069 Arguments are accessed within the user command via $arg0..$arg9. A
5072 print $arg0 + $arg1 + $arg2
5074 To execute the command use:
5077 Defines the command "adder" which prints the sum of its three arguments.
5078 Note the arguments are text substitutions, so they may reference variables,
5079 use complex expressions, or even perform inferior function calls.
5081 * New `if' and `while' commands
5083 This makes it possible to write more sophisticated user-defined
5084 commands. Both commands take a single argument, which is the
5085 expression to evaluate, and must be followed by the commands to
5086 execute, one per line, if the expression is nonzero, the list being
5087 terminated by the word `end'. The `if' command list may include an
5088 `else' word, which causes the following commands to be executed only
5089 if the expression is zero.
5091 * Fortran source language mode
5093 GDB now includes partial support for Fortran 77. It will recognize
5094 Fortran programs and can evaluate a subset of Fortran expressions, but
5095 variables and functions may not be handled correctly. GDB will work
5096 with G77, but does not yet know much about symbols emitted by other
5099 * Better HPUX support
5101 Most debugging facilities now work on dynamic executables for HPPAs
5102 running hpux9 or later. You can attach to running dynamically linked
5103 processes, but by default the dynamic libraries will be read-only, so
5104 for instance you won't be able to put breakpoints in them. To change
5105 that behavior do the following before running the program:
5111 This will cause the libraries to be mapped private and read-write.
5112 To revert to the normal behavior, do this:
5118 You cannot set breakpoints or examine data in the library until after
5119 the library is loaded if the function/data symbols do not have
5122 GDB can now also read debug symbols produced by the HP C compiler on
5123 HPPAs (sorry, no C++, Fortran or 68k support).
5125 * Target byte order now dynamically selectable
5127 You can choose which byte order to use with a target system, via the
5128 commands "set endian big" and "set endian little", and you can see the
5129 current setting by using "show endian". You can also give the command
5130 "set endian auto", in which case GDB will use the byte order
5131 associated with the executable. Currently, only embedded MIPS
5132 configurations support dynamic selection of target byte order.
5134 * New DOS host serial code
5136 This version uses DPMI interrupts to handle buffered I/O, so you
5137 no longer need to run asynctsr when debugging boards connected to
5140 *** Changes in GDB-4.13:
5142 * New "complete" command
5144 This lists all the possible completions for the rest of the line, if it
5145 were to be given as a command itself. This is intended for use by emacs.
5147 * Trailing space optional in prompt
5149 "set prompt" no longer adds a space for you after the prompt you set. This
5150 allows you to set a prompt which ends in a space or one that does not.
5152 * Breakpoint hit counts
5154 "info break" now displays a count of the number of times the breakpoint
5155 has been hit. This is especially useful in conjunction with "ignore"; you
5156 can ignore a large number of breakpoint hits, look at the breakpoint info
5157 to see how many times the breakpoint was hit, then run again, ignoring one
5158 less than that number, and this will get you quickly to the last hit of
5161 * Ability to stop printing at NULL character
5163 "set print null-stop" will cause GDB to stop printing the characters of
5164 an array when the first NULL is encountered. This is useful when large
5165 arrays actually contain only short strings.
5167 * Shared library breakpoints
5169 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5170 breakpoints in shared libraries before the executable is run.
5172 * Hardware watchpoints
5174 There is a new hardware breakpoint for the watch command for sparclite
5175 targets. See gdb/sparclite/hw_breakpoint.note.
5177 Hardware watchpoints are also now supported under GNU/Linux.
5181 Annotations have been added. These are for use with graphical interfaces,
5182 and are still experimental. Currently only gdba.el uses these.
5184 * Improved Irix 5 support
5186 GDB now works properly with Irix 5.2.
5188 * Improved HPPA support
5190 GDB now works properly with the latest GCC and GAS.
5192 * New native configurations
5194 Sequent PTX4 i[34]86-sequent-ptx4
5195 HPPA running OSF/1 hppa*-*-osf*
5196 Atari TT running SVR4 m68*-*-sysv4*
5197 RS/6000 LynxOS rs6000-*-lynxos*
5201 OS/9000 i[34]86-*-os9k
5202 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5205 * Hitachi SH7000 and E7000-PC ICE support
5207 There is now support for communicating with the Hitachi E7000-PC ICE.
5208 This is available automatically when GDB is configured for the SH.
5212 As usual, a variety of small fixes and improvements, both generic
5213 and configuration-specific. See the ChangeLog for more detail.
5215 *** Changes in GDB-4.12:
5217 * Irix 5 is now supported
5221 GDB-4.12 on the HPPA has a number of changes which make it unable
5222 to debug the output from the currently released versions of GCC and
5223 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5224 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5225 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5228 *** Changes in GDB-4.11:
5230 * User visible changes:
5234 The "set remotedebug" option is now consistent between the mips remote
5235 target, remote targets using the gdb-specific protocol, UDI (AMD's
5236 debug protocol for the 29k) and the 88k bug monitor. It is now an
5237 integer specifying a debug level (normally 0 or 1, but 2 means more
5238 debugging info for the mips target).
5240 * DEC Alpha native support
5242 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5243 debug info, but GDB works fairly well with the DEC compiler and should
5244 work with a future GCC release. See the README file for a few
5245 Alpha-specific notes.
5247 * Preliminary thread implementation
5249 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5251 * LynxOS native and target support for 386
5253 This release has been hosted on LynxOS 2.2, and also can be configured
5254 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5257 * Improvements in C++ mangling/demangling.
5259 This release has much better g++ debugging, specifically in name
5260 mangling/demangling, virtual function calls, print virtual table,
5261 call methods, ...etc.
5263 *** Changes in GDB-4.10:
5265 * User visible changes:
5267 Remote debugging using the GDB-specific (`target remote') protocol now
5268 supports the `load' command. This is only useful if you have some
5269 other way of getting the stub to the target system, and you can put it
5270 somewhere in memory where it won't get clobbered by the download.
5272 Filename completion now works.
5274 When run under emacs mode, the "info line" command now causes the
5275 arrow to point to the line specified. Also, "info line" prints
5276 addresses in symbolic form (as well as hex).
5278 All vxworks based targets now support a user settable option, called
5279 vxworks-timeout. This option represents the number of seconds gdb
5280 should wait for responses to rpc's. You might want to use this if
5281 your vxworks target is, perhaps, a slow software simulator or happens
5282 to be on the far side of a thin network line.
5286 This release contains support for using a DEC alpha as a GDB host for
5287 cross debugging. Native alpha debugging is not supported yet.
5290 *** Changes in GDB-4.9:
5294 This is the first GDB release which is accompanied by a matching testsuite.
5295 The testsuite requires installation of dejagnu, which should be available
5296 via ftp from most sites that carry GNU software.
5300 'Cfront' style demangling has had its name changed to 'ARM' style, to
5301 emphasize that it was written from the specifications in the C++ Annotated
5302 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5303 disclaimers, it still generated too much confusion with users attempting to
5304 use gdb with AT&T cfront.
5308 GDB now uses a standard remote interface to a simulator library.
5309 So far, the library contains simulators for the Zilog Z8001/2, the
5310 Hitachi H8/300, H8/500 and Super-H.
5312 * New targets supported
5314 H8/300 simulator h8300-hitachi-hms or h8300hms
5315 H8/500 simulator h8500-hitachi-hms or h8500hms
5316 SH simulator sh-hitachi-hms or sh
5317 Z8000 simulator z8k-zilog-none or z8ksim
5318 IDT MIPS board over serial line mips-idt-ecoff
5320 Cross-debugging to GO32 targets is supported. It requires a custom
5321 version of the i386-stub.c module which is integrated with the
5322 GO32 memory extender.
5324 * New remote protocols
5326 MIPS remote debugging protocol.
5328 * New source languages supported
5330 This version includes preliminary support for Chill, a Pascal like language
5331 used by telecommunications companies. Chill support is also being integrated
5332 into the GNU compiler, but we don't know when it will be publically available.
5335 *** Changes in GDB-4.8:
5337 * HP Precision Architecture supported
5339 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5340 version of this support was available as a set of patches from the
5341 University of Utah. GDB does not support debugging of programs
5342 compiled with the HP compiler, because HP will not document their file
5343 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5344 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5346 Many problems in the preliminary version have been fixed.
5348 * Faster and better demangling
5350 We have improved template demangling and fixed numerous bugs in the GNU style
5351 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5352 character types (wchar_t) are now supported. Demangling of each symbol is now
5353 only done once, and is cached when the symbol table for a file is read in.
5354 This results in a small increase in memory usage for C programs, a moderate
5355 increase in memory usage for C++ programs, and a fantastic speedup in
5358 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5359 from the specifications in the Annotated Reference Manual, which AT&T's
5360 compiler does not actually implement.
5362 * G++ multiple inheritance compiler problem
5364 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5365 inheritance lattices was reworked to properly discover ambiguities. We
5366 recently found an example which causes this new algorithm to fail in a
5367 very subtle way, producing bad debug information for those classes.
5368 The file 'gcc.patch' (in this directory) can be applied to gcc to
5369 circumvent the problem. A future GCC release will contain a complete
5372 The previous G++ debug info problem (mentioned below for the gdb-4.7
5373 release) is fixed in gcc version 2.3.2.
5375 * Improved configure script
5377 The `configure' script will now attempt to guess your system type if
5378 you don't supply a host system type. The old scheme of supplying a
5379 host system triplet is preferable over using this. All the magic is
5380 done in the new `config.guess' script. Examine it for details.
5382 We have also brought our configure script much more in line with the FSF's
5383 version. It now supports the --with-xxx options. In particular,
5384 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5385 The resulting GDB will not be able to read arbitrary object file formats --
5386 only the format ``expected'' to be used on the configured target system.
5387 We hope to make this the default in a future release.
5389 * Documentation improvements
5391 There's new internal documentation on how to modify GDB, and how to
5392 produce clean changes to the code. We implore people to read it
5393 before submitting changes.
5395 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5396 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5397 `info' files are also provided. To build `info' files from scratch,
5398 you will need the latest `makeinfo' release, which will be available in
5399 a future texinfo-X.Y release.
5401 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5402 We're not sure exactly which versions have this problem, but it has
5403 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5404 or better. If that isn't possible, there is a patch in
5405 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5406 around this problem.
5410 GDB now supports array constants that can be used in expressions typed in by
5411 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5412 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5415 The new directory `gdb/sparclite' contains a program that demonstrates
5416 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5418 * New native hosts supported
5420 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5421 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5423 * New targets supported
5425 AMD 29k family via UDI a29k-amd-udi or udi29k
5427 * New file formats supported
5429 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5430 HPUX core files, and SCO 3.2v2 core files.
5434 Attaching to processes now works again; thanks for the many bug reports.
5436 We have also stomped on a bunch of core dumps caused by
5437 printf_filtered("%s") problems.
5439 We eliminated a copyright problem on the rpc and ptrace header files
5440 for VxWorks, which was discovered at the last minute during the 4.7
5441 release. You should now be able to build a VxWorks GDB.
5443 You can now interrupt gdb while an attached process is running. This
5444 will cause the attached process to stop, and give control back to GDB.
5446 We fixed problems caused by using too many file descriptors
5447 for reading symbols from object files and libraries. This was
5448 especially a problem for programs that used many (~100) shared
5451 The `step' command now only enters a subroutine if there is line number
5452 information for the subroutine. Otherwise it acts like the `next'
5453 command. Previously, `step' would enter subroutines if there was
5454 any debugging information about the routine. This avoids problems
5455 when using `cc -g1' on MIPS machines.
5457 * Internal improvements
5459 GDB's internal interfaces have been improved to make it easier to support
5460 debugging of multiple languages in the future.
5462 GDB now uses a common structure for symbol information internally.
5463 Minimal symbols (derived from linkage symbols in object files), partial
5464 symbols (from a quick scan of debug information), and full symbols
5465 contain a common subset of information, making it easier to write
5466 shared code that handles any of them.
5468 * New command line options
5470 We now accept --silent as an alias for --quiet.
5474 The memory-mapped-malloc library is now licensed under the GNU Library
5475 General Public License.
5477 *** Changes in GDB-4.7:
5479 * Host/native/target split
5481 GDB has had some major internal surgery to untangle the support for
5482 hosts and remote targets. Now, when you configure GDB for a remote
5483 target, it will no longer load in all of the support for debugging
5484 local programs on the host. When fully completed and tested, this will
5485 ensure that arbitrary host/target combinations are possible.
5487 The primary conceptual shift is to separate the non-portable code in
5488 GDB into three categories. Host specific code is required any time GDB
5489 is compiled on that host, regardless of the target. Target specific
5490 code relates to the peculiarities of the target, but can be compiled on
5491 any host. Native specific code is everything else: it can only be
5492 built when the host and target are the same system. Child process
5493 handling and core file support are two common `native' examples.
5495 GDB's use of /proc for controlling Unix child processes is now cleaner.
5496 It has been split out into a single module under the `target_ops' vector,
5497 plus two native-dependent functions for each system that uses /proc.
5499 * New hosts supported
5501 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5502 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5503 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5505 * New targets supported
5507 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5508 68030 and CPU32 m68030-*-*, m68332-*-*
5510 * New native hosts supported
5512 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5513 (386bsd is not well tested yet)
5514 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5516 * New file formats supported
5518 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5519 supports reading of `a.out.adobe' object files, which are an a.out
5520 format extended with minimal information about multiple sections.
5524 `show copying' is the same as the old `info copying'.
5525 `show warranty' is the same as `info warrantee'.
5526 These were renamed for consistency. The old commands continue to work.
5528 `info handle' is a new alias for `info signals'.
5530 You can now define pre-command hooks, which attach arbitrary command
5531 scripts to any command. The commands in the hook will be executed
5532 prior to the user's command. You can also create a hook which will be
5533 executed whenever the program stops. See gdb.texinfo.
5537 We now deal with Cfront style name mangling, and can even extract type
5538 info from mangled symbols. GDB can automatically figure out which
5539 symbol mangling style your C++ compiler uses.
5541 Calling of methods and virtual functions has been improved as well.
5545 The crash that occured when debugging Sun Ansi-C compiled binaries is
5546 fixed. This was due to mishandling of the extra N_SO stabs output
5549 We also finally got Ultrix 4.2 running in house, and fixed core file
5550 support, with help from a dozen people on the net.
5552 John M. Farrell discovered that the reason that single-stepping was so
5553 slow on all of the Mips based platforms (primarily SGI and DEC) was
5554 that we were trying to demangle and lookup a symbol used for internal
5555 purposes on every instruction that was being stepped through. Changing
5556 the name of that symbol so that it couldn't be mistaken for a C++
5557 mangled symbol sped things up a great deal.
5559 Rich Pixley sped up symbol lookups in general by getting much smarter
5560 about when C++ symbol mangling is necessary. This should make symbol
5561 completion (TAB on the command line) much faster. It's not as fast as
5562 we'd like, but it's significantly faster than gdb-4.6.
5566 A new user controllable variable 'call_scratch_address' can
5567 specify the location of a scratch area to be used when GDB
5568 calls a function in the target. This is necessary because the
5569 usual method of putting the scratch area on the stack does not work
5570 in systems that have separate instruction and data spaces.
5572 We integrated changes to support the 29k UDI (Universal Debugger
5573 Interface), but discovered at the last minute that we didn't have all
5574 of the appropriate copyright paperwork. We are working with AMD to
5575 resolve this, and hope to have it available soon.
5579 We have sped up the remote serial line protocol, especially for targets
5580 with lots of registers. It now supports a new `expedited status' ('T')
5581 message which can be used in place of the existing 'S' status message.
5582 This allows the remote stub to send only the registers that GDB
5583 needs to make a quick decision about single-stepping or conditional
5584 breakpoints, eliminating the need to fetch the entire register set for
5585 each instruction being stepped through.
5587 The GDB remote serial protocol now implements a write-through cache for
5588 registers, only re-reading the registers if the target has run.
5590 There is also a new remote serial stub for SPARC processors. You can
5591 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5592 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5593 processor with a serial port.
5597 Configure.in files have become much easier to read and modify. A new
5598 `table driven' format makes it more obvious what configurations are
5599 supported, and what files each one uses.
5603 There is a new opcodes library which will eventually contain all of the
5604 disassembly routines and opcode tables. At present, it only contains
5605 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5606 disassembler (binutils/objdump) to share these routines.
5608 The libiberty library is now copylefted under the GNU Library General
5609 Public License. This allows more liberal use, and was done so libg++
5610 can use it. This makes no difference to GDB, since the Library License
5611 grants all the rights from the General Public License.
5615 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5616 reference to the stabs symbol info used by the debugger. It is (as far
5617 as we know) the only published document on this fascinating topic. We
5618 encourage you to read it, compare it to the stabs information on your
5619 system, and send improvements on the document in general (to
5620 bug-gdb@prep.ai.mit.edu).
5622 And, of course, many bugs have been fixed.
5625 *** Changes in GDB-4.6:
5627 * Better support for C++ function names
5629 GDB now accepts as input the "demangled form" of C++ overloaded function
5630 names and member function names, and can do command completion on such names
5631 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5632 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5633 Make use of command completion, it is your friend.
5635 GDB also now accepts a variety of C++ mangled symbol formats. They are
5636 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5637 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5638 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5639 for the list of formats.
5641 * G++ symbol mangling problem
5643 Recent versions of gcc have a bug in how they emit debugging information for
5644 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5645 directory) can be applied to gcc to fix the problem. Alternatively, if you
5646 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5647 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5648 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5651 * New 'maintenance' command
5653 All of the commands related to hacking GDB internals have been moved out of
5654 the main command set, and now live behind the 'maintenance' command. This
5655 can also be abbreviated as 'mt'. The following changes were made:
5657 dump-me -> maintenance dump-me
5658 info all-breakpoints -> maintenance info breakpoints
5659 printmsyms -> maintenance print msyms
5660 printobjfiles -> maintenance print objfiles
5661 printpsyms -> maintenance print psymbols
5662 printsyms -> maintenance print symbols
5664 The following commands are new:
5666 maintenance demangle Call internal GDB demangler routine to
5667 demangle a C++ link name and prints the result.
5668 maintenance print type Print a type chain for a given symbol
5670 * Change to .gdbinit file processing
5672 We now read the $HOME/.gdbinit file before processing the argv arguments
5673 (e.g. reading symbol files or core files). This allows global parameters to
5674 be set, which will apply during the symbol reading. The ./.gdbinit is still
5675 read after argv processing.
5677 * New hosts supported
5679 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5681 GNU/Linux support i386-unknown-linux or linux
5683 We are also including code to support the HP/PA running BSD and HPUX. This
5684 is almost guaranteed not to work, as we didn't have time to test or build it
5685 for this release. We are including it so that the more adventurous (or
5686 masochistic) of you can play with it. We also had major problems with the
5687 fact that the compiler that we got from HP doesn't support the -g option.
5690 * New targets supported
5692 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5694 * More smarts about finding #include files
5696 GDB now remembers the compilation directory for all include files, and for
5697 all files from which C is generated (like yacc and lex sources). This
5698 greatly improves GDB's ability to find yacc/lex sources, and include files,
5699 especially if you are debugging your program from a directory different from
5700 the one that contains your sources.
5702 We also fixed a bug which caused difficulty with listing and setting
5703 breakpoints in include files which contain C code. (In the past, you had to
5704 try twice in order to list an include file that you hadn't looked at before.)
5706 * Interesting infernals change
5708 GDB now deals with arbitrary numbers of sections, where the symbols for each
5709 section must be relocated relative to that section's landing place in the
5710 target's address space. This work was needed to support ELF with embedded
5711 stabs used by Solaris-2.0.
5713 * Bug fixes (of course!)
5715 There have been loads of fixes for the following things:
5716 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5717 i960, stabs, DOS(GO32), procfs, etc...
5719 See the ChangeLog for details.
5721 *** Changes in GDB-4.5:
5723 * New machines supported (host and target)
5725 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5727 SGI Irix-4.x mips-sgi-irix4 or iris4
5729 * New malloc package
5731 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5732 Mmalloc is capable of handling mutiple heaps of memory. It is also
5733 capable of saving a heap to a file, and then mapping it back in later.
5734 This can be used to greatly speedup the startup of GDB by using a
5735 pre-parsed symbol table which lives in a mmalloc managed heap. For
5736 more details, please read mmalloc/mmalloc.texi.
5740 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5741 'help info proc' for details.
5743 * MIPS ecoff symbol table format
5745 The code that reads MIPS symbol table format is now supported on all hosts.
5746 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5749 * File name changes for MS-DOS
5751 Many files in the config directories have been renamed to make it easier to
5752 support GDB on MS-DOSe systems (which have very restrictive file name
5753 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5754 environment) is close to working but has some remaining problems. Note
5755 that debugging of DOS programs is not supported, due to limitations
5756 in the ``operating system'', but it can be used to host cross-debugging.
5758 * Cross byte order fixes
5760 Many fixes have been made to support cross debugging of Sparc and MIPS
5761 targets from hosts whose byte order differs.
5763 * New -mapped and -readnow options
5765 If memory-mapped files are available on your system through the 'mmap'
5766 system call, you can use the -mapped option on the `file' or
5767 `symbol-file' commands to cause GDB to write the symbols from your
5768 program into a reusable file. If the program you are debugging is
5769 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5770 Future GDB debugging sessions will notice the presence of this file,
5771 and will quickly map in symbol information from it, rather than reading
5772 the symbol table from the executable program. Using the '-mapped'
5773 option in a GDB `file' or `symbol-file' command has the same effect as
5774 starting GDB with the '-mapped' command-line option.
5776 You can cause GDB to read the entire symbol table immediately by using
5777 the '-readnow' option with any of the commands that load symbol table
5778 information (or on the GDB command line). This makes the command
5779 slower, but makes future operations faster.
5781 The -mapped and -readnow options are typically combined in order to
5782 build a `fred.syms' file that contains complete symbol information.
5783 A simple GDB invocation to do nothing but build a `.syms' file for future
5786 gdb -batch -nx -mapped -readnow programname
5788 The `.syms' file is specific to the host machine on which GDB is run.
5789 It holds an exact image of GDB's internal symbol table. It cannot be
5790 shared across multiple host platforms.
5792 * longjmp() handling
5794 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5795 siglongjmp() without losing control. This feature has not yet been ported to
5796 all systems. It currently works on many 386 platforms, all MIPS-based
5797 platforms (SGI, DECstation, etc), and Sun3/4.
5801 Preliminary work has been put in to support the new Solaris OS from Sun. At
5802 this time, it can control and debug processes, but it is not capable of
5807 As always, many many bug fixes. The major areas were with g++, and mipsread.
5808 People using the MIPS-based platforms should experience fewer mysterious
5809 crashes and trashed symbol tables.
5811 *** Changes in GDB-4.4:
5813 * New machines supported (host and target)
5815 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5817 BSD Reno on Vax vax-dec-bsd
5818 Ultrix on Vax vax-dec-ultrix
5820 * New machines supported (target)
5822 AMD 29000 embedded, using EBMON a29k-none-none
5826 GDB continues to improve its handling of C++. `References' work better.
5827 The demangler has also been improved, and now deals with symbols mangled as
5828 per the Annotated C++ Reference Guide.
5830 GDB also now handles `stabs' symbol information embedded in MIPS
5831 `ecoff' symbol tables. Since the ecoff format was not easily
5832 extensible to handle new languages such as C++, this appeared to be a
5833 good way to put C++ debugging info into MIPS binaries. This option
5834 will be supported in the GNU C compiler, version 2, when it is
5837 * New features for SVR4
5839 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5840 shared libraries. Debugging dynamically linked programs should present
5841 only minor differences from debugging statically linked programs.
5843 The `info proc' command will print out information about any process
5844 on an SVR4 system (including the one you are debugging). At the moment,
5845 it prints the address mappings of the process.
5847 If you bring up GDB on another SVR4 system, please send mail to
5848 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5850 * Better dynamic linking support in SunOS
5852 Reading symbols from shared libraries which contain debugging symbols
5853 now works properly. However, there remain issues such as automatic
5854 skipping of `transfer vector' code during function calls, which
5855 make it harder to debug code in a shared library, than to debug the
5856 same code linked statically.
5860 GDB is now using the latest `getopt' routines from the FSF. This
5861 version accepts the -- prefix for options with long names. GDB will
5862 continue to accept the old forms (-option and +option) as well.
5863 Various single letter abbreviations for options have been explicity
5864 added to the option table so that they won't get overshadowed in the
5865 future by other options that begin with the same letter.
5869 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5870 Many assorted bugs have been handled. Many more remain to be handled.
5871 See the various ChangeLog files (primarily in gdb and bfd) for details.
5874 *** Changes in GDB-4.3:
5876 * New machines supported (host and target)
5878 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5879 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5880 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5882 * Almost SCO Unix support
5884 We had hoped to support:
5885 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5886 (except for core file support), but we discovered very late in the release
5887 that it has problems with process groups that render gdb unusable. Sorry
5888 about that. I encourage people to fix it and post the fixes.
5890 * Preliminary ELF and DWARF support
5892 GDB can read ELF object files on System V Release 4, and can handle
5893 debugging records for C, in DWARF format, in ELF files. This support
5894 is preliminary. If you bring up GDB on another SVR4 system, please
5895 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5900 GDB now uses the latest `readline' library. One user-visible change
5901 is that two tabs will list possible command completions, which previously
5902 required typing M-? (meta-question mark, or ESC ?).
5906 The `stepi' bug that many of you noticed has been squashed.
5907 Many bugs in C++ have been handled. Many more remain to be handled.
5908 See the various ChangeLog files (primarily in gdb and bfd) for details.
5910 * State of the MIPS world (in case you wondered):
5912 GDB can understand the symbol tables emitted by the compilers
5913 supplied by most vendors of MIPS-based machines, including DEC. These
5914 symbol tables are in a format that essentially nobody else uses.
5916 Some versions of gcc come with an assembler post-processor called
5917 mips-tfile. This program is required if you want to do source-level
5918 debugging of gcc-compiled programs. I believe FSF does not ship
5919 mips-tfile with gcc version 1, but it will eventually come with gcc
5922 Debugging of g++ output remains a problem. g++ version 1.xx does not
5923 really support it at all. (If you're lucky, you should be able to get
5924 line numbers and stack traces to work, but no parameters or local
5925 variables.) With some work it should be possible to improve the
5928 When gcc version 2 is released, you will have somewhat better luck.
5929 However, even then you will get confusing results for inheritance and
5932 We will eventually provide full debugging of g++ output on
5933 DECstations. This will probably involve some kind of stabs-in-ecoff
5934 encapulation, but the details have not been worked out yet.
5937 *** Changes in GDB-4.2:
5939 * Improved configuration
5941 Only one copy of `configure' exists now, and it is not self-modifying.
5942 Porting BFD is simpler.
5946 The `step' and `next' commands now only stop at the first instruction
5947 of a source line. This prevents the multiple stops that used to occur
5948 in switch statements, for-loops, etc. `Step' continues to stop if a
5949 function that has debugging information is called within the line.
5953 Lots of small bugs fixed. More remain.
5955 * New host supported (not target)
5957 Intel 386 PC clone running Mach i386-none-mach
5960 *** Changes in GDB-4.1:
5962 * Multiple source language support
5964 GDB now has internal scaffolding to handle several source languages.
5965 It determines the type of each source file from its filename extension,
5966 and will switch expression parsing and number formatting to match the
5967 language of the function in the currently selected stack frame.
5968 You can also specifically set the language to be used, with
5969 `set language c' or `set language modula-2'.
5973 GDB now has preliminary support for the GNU Modula-2 compiler,
5974 currently under development at the State University of New York at
5975 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5976 continue through the fall of 1991 and into 1992.
5978 Other Modula-2 compilers are currently not supported, and attempting to
5979 debug programs compiled with them will likely result in an error as the
5980 symbol table is read. Feel free to work on it, though!
5982 There are hooks in GDB for strict type checking and range checking,
5983 in the `Modula-2 philosophy', but they do not currently work.
5987 GDB can now write to executable and core files (e.g. patch
5988 a variable's value). You must turn this switch on, specify
5989 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5990 by assigning a new value to a variable. Modifications take
5993 * Automatic SunOS shared library reading
5995 When you run your program, GDB automatically determines where its
5996 shared libraries (if any) have been loaded, and reads their symbols.
5997 The `share' command is no longer needed. This also works when
5998 examining core files.
6002 You can specify the number of lines that the `list' command shows.
6005 * New machines supported (host and target)
6007 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6008 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6009 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6011 * New hosts supported (not targets)
6013 IBM RT/PC: romp-ibm-aix or rtpc
6015 * New targets supported (not hosts)
6017 AMD 29000 embedded with COFF a29k-none-coff
6018 AMD 29000 embedded with a.out a29k-none-aout
6019 Ultracomputer remote kernel debug a29k-nyu-kern
6021 * New remote interfaces
6027 *** Changes in GDB-4.0:
6031 Wide output is wrapped at good places to make the output more readable.
6033 Gdb now supports cross-debugging from a host machine of one type to a
6034 target machine of another type. Communication with the target system
6035 is over serial lines. The ``target'' command handles connecting to the
6036 remote system; the ``load'' command will download a program into the
6037 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6038 also supports debugging of realtime processes running under VxWorks,
6039 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6040 stub on the target system.
6042 New CPUs supported include the AMD 29000 and Intel 960.
6044 GDB now reads object files and symbol tables via a ``binary file''
6045 library, which allows a single copy of GDB to debug programs of multiple
6046 object file types such as a.out and coff.
6048 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6049 refcard.dvi and refcard.ps are available to format it).
6052 * Control-Variable user interface simplified
6054 All variables that control the operation of the debugger can be set
6055 by the ``set'' command, and displayed by the ``show'' command.
6057 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6058 ``Show prompt'' produces the response:
6059 Gdb's prompt is new-gdb=>.
6061 What follows are the NEW set commands. The command ``help set'' will
6062 print a complete list of old and new set commands. ``help set FOO''
6063 will give a longer description of the variable FOO. ``show'' will show
6064 all of the variable descriptions and their current settings.
6066 confirm on/off: Enables warning questions for operations that are
6067 hard to recover from, e.g. rerunning the program while
6068 it is already running. Default is ON.
6070 editing on/off: Enables EMACS style command line editing
6071 of input. Previous lines can be recalled with
6072 control-P, the current line can be edited with control-B,
6073 you can search for commands with control-R, etc.
6076 history filename NAME: NAME is where the gdb command history
6077 will be stored. The default is .gdb_history,
6078 or the value of the environment variable
6081 history size N: The size, in commands, of the command history. The
6082 default is 256, or the value of the environment variable
6085 history save on/off: If this value is set to ON, the history file will
6086 be saved after exiting gdb. If set to OFF, the
6087 file will not be saved. The default is OFF.
6089 history expansion on/off: If this value is set to ON, then csh-like
6090 history expansion will be performed on
6091 command line input. The default is OFF.
6093 radix N: Sets the default radix for input and output. It can be set
6094 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6095 in the current radix, so "set radix 10" is always a no-op.
6097 height N: This integer value is the number of lines on a page. Default
6098 is 24, the current `stty rows'' setting, or the ``li#''
6099 setting from the termcap entry matching the environment
6102 width N: This integer value is the number of characters on a line.
6103 Default is 80, the current `stty cols'' setting, or the ``co#''
6104 setting from the termcap entry matching the environment
6107 Note: ``set screensize'' is obsolete. Use ``set height'' and
6108 ``set width'' instead.
6110 print address on/off: Print memory addresses in various command displays,
6111 such as stack traces and structure values. Gdb looks
6112 more ``symbolic'' if you turn this off; it looks more
6113 ``machine level'' with it on. Default is ON.
6115 print array on/off: Prettyprint arrays. New convenient format! Default
6118 print demangle on/off: Print C++ symbols in "source" form if on,
6121 print asm-demangle on/off: Same, for assembler level printouts
6124 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6127 * Support for Epoch Environment.
6129 The epoch environment is a version of Emacs v18 with windowing. One
6130 new command, ``inspect'', is identical to ``print'', except that if you
6131 are running in the epoch environment, the value is printed in its own
6135 * Support for Shared Libraries
6137 GDB can now debug programs and core files that use SunOS shared libraries.
6138 Symbols from a shared library cannot be referenced
6139 before the shared library has been linked with the program (this
6140 happens after you type ``run'' and before the function main() is entered).
6141 At any time after this linking (including when examining core files
6142 from dynamically linked programs), gdb reads the symbols from each
6143 shared library when you type the ``sharedlibrary'' command.
6144 It can be abbreviated ``share''.
6146 sharedlibrary REGEXP: Load shared object library symbols for files
6147 matching a unix regular expression. No argument
6148 indicates to load symbols for all shared libraries.
6150 info sharedlibrary: Status of loaded shared libraries.
6155 A watchpoint stops execution of a program whenever the value of an
6156 expression changes. Checking for this slows down execution
6157 tremendously whenever you are in the scope of the expression, but is
6158 quite useful for catching tough ``bit-spreader'' or pointer misuse
6159 problems. Some machines such as the 386 have hardware for doing this
6160 more quickly, and future versions of gdb will use this hardware.
6162 watch EXP: Set a watchpoint (breakpoint) for an expression.
6164 info watchpoints: Information about your watchpoints.
6166 delete N: Deletes watchpoint number N (same as breakpoints).
6167 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6168 enable N: Re-enables watchpoint number N (same as breakpoints).
6171 * C++ multiple inheritance
6173 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6176 * C++ exception handling
6178 Gdb now supports limited C++ exception handling. Besides the existing
6179 ability to breakpoint on an exception handler, gdb can breakpoint on
6180 the raising of an exception (before the stack is peeled back to the
6183 catch FOO: If there is a FOO exception handler in the dynamic scope,
6184 set a breakpoint to catch exceptions which may be raised there.
6185 Multiple exceptions (``catch foo bar baz'') may be caught.
6187 info catch: Lists all exceptions which may be caught in the
6188 current stack frame.
6191 * Minor command changes
6193 The command ``call func (arg, arg, ...)'' now acts like the print
6194 command, except it does not print or save a value if the function's result
6195 is void. This is similar to dbx usage.
6197 The ``up'' and ``down'' commands now always print the frame they end up
6198 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6199 frames without printing.
6201 * New directory command
6203 'dir' now adds directories to the FRONT of the source search path.
6204 The path starts off empty. Source files that contain debug information
6205 about the directory in which they were compiled can be found even
6206 with an empty path; Sun CC and GCC include this information. If GDB can't
6207 find your source file in the current directory, type "dir .".
6209 * Configuring GDB for compilation
6211 For normal use, type ``./configure host''. See README or gdb.texinfo
6214 GDB now handles cross debugging. If you are remotely debugging between
6215 two different machines, type ``./configure host -target=targ''.
6216 Host is the machine where GDB will run; targ is the machine
6217 where the program that you are debugging will run.