1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.9
6 * Support for process record-replay and reverse debugging on aarch64*-linux*
7 targets has been added. GDB now supports recording of A64 instruction set
8 including advance SIMD instructions.
10 * GDB now honors the content of the file /proc/PID/coredump_filter
11 (PID is the process ID) on GNU/Linux systems. This file can be used
12 to specify the types of memory mappings that will be included in a
13 corefile. For more information, please refer to the manual page of
14 "core(5)". GDB also has a new command: "set use-coredump-filter
15 on|off". It allows to set whether GDB will read the content of the
16 /proc/PID/coredump_filter file when generating a corefile.
18 * The "info os" command on GNU/Linux can now display information on
20 "info os cpus" Listing of all cpus/cores on the system
22 * GDB has two new commands: "set serial parity odd|even|none" and
23 "show serial parity". These allows to set or show parity for the
26 * The "info source" command now displays the producer string if it was
27 present in the debug info. This typically includes the compiler version
28 and may include things like its command line arguments.
30 * The "info dll", an alias of the "info sharedlibrary" command,
31 is now available on all platforms.
33 * Directory names supplied to the "set sysroot" commands may be
34 prefixed with "target:" to tell GDB to access shared libraries from
35 the target system, be it local or remote. This replaces the prefix
36 "remote:". The default sysroot has been changed from "" to
37 "target:". "remote:" is automatically converted to "target:" for
38 backward compatibility.
40 * The system root specified by "set sysroot" will be prepended to the
41 filename of the main executable (if reported to GDB as absolute by
42 the operating system) when starting processes remotely, and when
43 attaching to already-running local or remote processes.
45 * GDB now supports automatic location and retrieval of executable
46 files from remote targets. Remote debugging can now be initiated
47 using only a "target remote" or "target extended-remote" command
48 (no "set sysroot" or "file" commands are required). See "New remote
51 * The "dump" command now supports verilog hex format.
53 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
57 ** Memory ports can now be unbuffered.
61 ** gdb.Objfile objects have a new attribute "username",
62 which is the name of the objfile as specified by the user,
63 without, for example, resolving symlinks.
64 ** You can now write frame unwinders in Python.
65 ** gdb.Type objects have a new method "optimized_out",
66 returning optimized out gdb.Value instance of this type.
67 ** gdb.Value objects have new methods "reference_value" and
68 "const_value" which return a reference to the value and a
69 "const" version of the value respectively.
73 maint print symbol-cache
74 Print the contents of the symbol cache.
76 maint print symbol-cache-statistics
77 Print statistics of symbol cache usage.
79 maint flush-symbol-cache
80 Flush the contents of the symbol cache.
84 Start branch trace recording using Branch Trace Store (BTS) format.
87 Evaluate expression by using the compiler and print result.
91 Explicit commands for enabling and disabling tui mode.
94 set mpx bound on i386 and amd64
95 Support for bound table investigation on Intel(R) MPX enabled applications.
100 Renamed from "set debug dwarf2-die".
102 Renamed from "show debug dwarf2-die".
105 Renamed from "set debug dwarf2-read".
106 show debug dwarf-read
107 Renamed from "show debug dwarf2-read".
109 maint set dwarf always-disassemble
110 Renamed from "maint set dwarf2 always-disassemble".
111 maint show dwarf always-disassemble
112 Renamed from "maint show dwarf2 always-disassemble".
114 maint set dwarf max-cache-age
115 Renamed from "maint set dwarf2 max-cache-age".
116 maint show dwarf max-cache-age
117 Renamed from "maint show dwarf2 max-cache-age".
120 show debug dwarf-line
121 Control display of debugging info regarding DWARF line processing.
125 Set the maximum number of candidates to be considered during
126 completion. The default value is 200. This limit allows GDB
127 to avoid generating large completion lists, the computation of
128 which can cause the debugger to become temporarily unresponsive.
130 maint set symbol-cache-size
131 maint show symbol-cache-size
132 Control the size of the symbol cache.
134 set|show record btrace bts buffer-size
135 Set and show the size of the ring buffer used for branch tracing in
137 The obtained size may differ from the requested size. Use "info
138 record" to see the obtained buffer size.
140 set debug linux-namespaces
141 show debug linux-namespaces
142 Control display of debugging info regarding Linux namespaces.
144 * The command 'thread apply all' can now support new option '-ascending'
145 to call its specified command for all threads in ascending order.
147 * Python/Guile scripting
149 ** GDB now supports auto-loading of Python/Guile scripts contained in the
150 special section named `.debug_gdb_scripts'.
154 qXfer:btrace-conf:read
155 Return the branch trace configuration for the current thread.
157 Qbtrace-conf:bts:size
158 Set the requested ring buffer size for branch tracing in BTS format.
161 Indicates a memory breakpoint instruction was executed, irrespective
162 of whether it was GDB that planted the breakpoint or the breakpoint
163 is hardcoded in the program. This is required for correct non-stop
167 Indicates the target stopped for a hardware breakpoint. This is
168 required for correct non-stop mode operation.
171 Return information about files on the remote system.
174 Return the full absolute name of the file that was executed to
175 create a process running on the remote system.
178 Indicates that a fork system call was executed.
181 Indicates that a vfork system call was executed.
183 vforkdone stop reason
184 Indicates that a vfork child of the specified process has executed
185 an exec or exit, allowing the vfork parent to resume execution.
187 fork-events and vfork-events features in qSupported
188 The qSupported packet allows GDB to request support for fork and
189 vfork events using new 'gdbfeatures' fork-events and vfork-events,
190 and the qSupported response can contain the corresponding
191 'stubfeatures'. Set and show commands can be used to display
192 whether these features are enabled.
194 * Extended-remote fork events
196 ** GDB now has support for fork events on extended-remote Linux
197 targets. For targets with Linux kernels 2.5.60 and later, this
198 enables follow-fork-mode and detach-on-fork for both fork and
199 vfork, as well as fork and vfork catchpoints.
201 * The info record command now shows the recording format and the
202 branch tracing configuration for the current thread when using
203 the btrace record target.
204 For the BTS format, it shows the ring buffer size.
206 * GDB now has support for DTrace USDT (Userland Static Defined
207 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
209 * GDB now supports access to vector registers on S/390 GNU/Linux
212 * Removed command line options
214 -xdb HP-UX XDB compatibility mode.
216 * Removed targets and native configurations
218 HP/PA running HP-UX hppa*-*-hpux*
219 Itanium running HP-UX ia64-*-hpux*
221 *** Changes in GDB 7.9.1
225 ** Xmethods can now specify a result type.
227 *** Changes in GDB 7.9
229 * GDB now supports hardware watchpoints on x86 GNU Hurd.
233 ** You can now access frame registers from Python scripts.
234 ** New attribute 'producer' for gdb.Symtab objects.
235 ** gdb.Objfile objects have a new attribute "progspace",
236 which is the gdb.Progspace object of the containing program space.
237 ** gdb.Objfile objects have a new attribute "owner".
238 ** gdb.Objfile objects have a new attribute "build_id",
239 which is the build ID generated when the file was built.
240 ** gdb.Objfile objects have a new method "add_separate_debug_file".
241 ** A new event "gdb.clear_objfiles" has been added, triggered when
242 selecting a new file to debug.
243 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
244 ** New function gdb.lookup_objfile.
246 New events which are triggered when GDB modifies the state of the
249 ** gdb.events.inferior_call_pre: Function call is about to be made.
250 ** gdb.events.inferior_call_post: Function call has just been made.
251 ** gdb.events.memory_changed: A memory location has been altered.
252 ** gdb.events.register_changed: A register has been altered.
254 * New Python-based convenience functions:
256 ** $_caller_is(name [, number_of_frames])
257 ** $_caller_matches(regexp [, number_of_frames])
258 ** $_any_caller_is(name [, number_of_frames])
259 ** $_any_caller_matches(regexp [, number_of_frames])
261 * GDB now supports the compilation and injection of source code into
262 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
263 to compile the source code to object code, and if successful, inject
264 and execute that code within the current context of the inferior.
265 Currently the C language is supported. The commands used to
266 interface with this new feature are:
268 compile code [-raw|-r] [--] [source code]
269 compile file [-raw|-r] filename
273 demangle [-l language] [--] name
274 Demangle "name" in the specified language, or the current language
275 if elided. This command is renamed from the "maint demangle" command.
276 The latter is kept as a no-op to avoid "maint demangle" being interpreted
277 as "maint demangler-warning".
279 queue-signal signal-name-or-number
280 Queue a signal to be delivered to the thread when it is resumed.
282 add-auto-load-scripts-directory directory
283 Add entries to the list of directories from which to load auto-loaded
286 maint print user-registers
287 List all currently available "user" registers.
289 compile code [-r|-raw] [--] [source code]
290 Compile, inject, and execute in the inferior the executable object
291 code produced by compiling the provided source code.
293 compile file [-r|-raw] filename
294 Compile and inject into the inferior the executable object code
295 produced by compiling the source code stored in the filename
298 * On resume, GDB now always passes the signal the program had stopped
299 for to the thread the signal was sent to, even if the user changed
300 threads before resuming. Previously GDB would often (but not
301 always) deliver the signal to the thread that happens to be current
304 * Conversely, the "signal" command now consistently delivers the
305 requested signal to the current thread. GDB now asks for
306 confirmation if the program had stopped for a signal and the user
307 switched threads meanwhile.
309 * "breakpoint always-inserted" modes "off" and "auto" merged.
311 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
312 won't remove breakpoints from the target until all threads stop,
313 even in non-stop mode. The "auto" mode has been removed, and "off"
314 is now the default mode.
318 set debug symbol-lookup
319 show debug symbol-lookup
320 Control display of debugging info regarding symbol lookup.
324 ** The -list-thread-groups command outputs an exit-code field for
325 inferiors that have exited.
329 MIPS SDE mips*-sde*-elf*
333 Support for these obsolete configurations has been removed.
335 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
336 SGI Irix-5.x mips-*-irix5*
337 SGI Irix-6.x mips-*-irix6*
338 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
339 VAX running Ultrix vax-*-ultrix*
341 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
342 and "assf"), have been removed. Use the "sharedlibrary" command, or
343 its alias "share", instead.
345 *** Changes in GDB 7.8
347 * New command line options
350 This is an alias for the --data-directory option.
352 * GDB supports printing and modifying of variable length automatic arrays
353 as specified in ISO C99.
355 * The ARM simulator now supports instruction level tracing
356 with or without disassembly.
360 GDB now has support for scripting using Guile. Whether this is
361 available is determined at configure time.
362 Guile version 2.0 or greater is required.
363 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
365 * New commands (for set/show, see "New options" below)
369 Invoke CODE by passing it to the Guile interpreter.
373 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
375 info auto-load guile-scripts [regexp]
376 Print the list of automatically loaded Guile scripts.
378 * The source command is now capable of sourcing Guile scripts.
379 This feature is dependent on the debugger being built with Guile support.
383 set print symbol-loading (off|brief|full)
384 show print symbol-loading
385 Control whether to print informational messages when loading symbol
386 information for a file. The default is "full", but when debugging
387 programs with large numbers of shared libraries the amount of output
390 set guile print-stack (none|message|full)
391 show guile print-stack
392 Show a stack trace when an error is encountered in a Guile script.
394 set auto-load guile-scripts (on|off)
395 show auto-load guile-scripts
396 Control auto-loading of Guile script files.
398 maint ada set ignore-descriptive-types (on|off)
399 maint ada show ignore-descriptive-types
400 Control whether the debugger should ignore descriptive types in Ada
401 programs. The default is not to ignore the descriptive types. See
402 the user manual for more details on descriptive types and the intended
403 usage of this option.
405 set auto-connect-native-target
407 Control whether GDB is allowed to automatically connect to the
408 native target for the run, attach, etc. commands when not connected
409 to any target yet. See also "target native" below.
411 set record btrace replay-memory-access (read-only|read-write)
412 show record btrace replay-memory-access
413 Control what memory accesses are allowed during replay.
415 maint set target-async (on|off)
416 maint show target-async
417 This controls whether GDB targets operate in synchronous or
418 asynchronous mode. Normally the default is asynchronous, if it is
419 available; but this can be changed to more easily debug problems
420 occurring only in synchronous mode.
422 set mi-async (on|off)
424 Control whether MI asynchronous mode is preferred. This supersedes
425 "set target-async" of previous GDB versions.
427 * "set target-async" is deprecated as a CLI option and is now an alias
428 for "set mi-async" (only puts MI into async mode).
430 * Background execution commands (e.g., "c&", "s&", etc.) are now
431 possible ``out of the box'' if the target supports them. Previously
432 the user would need to explicitly enable the possibility with the
433 "set target-async on" command.
435 * New features in the GDB remote stub, GDBserver
437 ** New option --debug-format=option1[,option2,...] allows one to add
438 additional text to each output. At present only timestamps
439 are supported: --debug-format=timestamps.
440 Timestamps can also be turned on with the
441 "monitor set debug-format timestamps" command from GDB.
443 * The 'record instruction-history' command now starts counting instructions
444 at one. This also affects the instruction ranges reported by the
445 'record function-call-history' command when given the /i modifier.
447 * The command 'record function-call-history' supports a new modifier '/c' to
448 indent the function names based on their call stack depth.
449 The fields for the '/i' and '/l' modifier have been reordered.
450 The source line range is now prefixed with 'at'.
451 The instruction range is now prefixed with 'inst'.
452 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
453 "record instruction-history" and "list" commands.
455 * The ranges given as arguments to the 'record function-call-history' and
456 'record instruction-history' commands are now inclusive.
458 * The btrace record target now supports the 'record goto' command.
459 For locations inside the execution trace, the back trace is computed
460 based on the information stored in the execution trace.
462 * The btrace record target supports limited reverse execution and replay.
463 The target does not record data and therefore does not allow reading
466 * The "catch syscall" command now works on s390*-linux* targets.
468 * The "compare-sections" command is no longer specific to target
469 remote. It now works with all targets.
471 * All native targets are now consistently called "native".
472 Consequently, the "target child", "target GNU", "target djgpp",
473 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
474 commands have been replaced with "target native". The QNX/NTO port
475 leaves the "procfs" target in place and adds a "native" target for
476 consistency with other ports. The impact on users should be minimal
477 as these commands previously either throwed an error, or were
478 no-ops. The target's name is visible in the output of the following
479 commands: "help target", "info target", "info files", "maint print
482 * The "target native" command now connects to the native target. This
483 can be used to launch native programs even when "set
484 auto-connect-native-target" is set to off.
486 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.
488 * Support for Intel(R) AVX-512 registers on GNU/Linux.
489 Support displaying and modifying Intel(R) AVX-512 registers
490 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
494 qXfer:btrace:read's annex
495 The qXfer:btrace:read packet supports a new annex 'delta' to read
496 branch trace incrementally.
500 ** Valid Python operations on gdb.Value objects representing
501 structs/classes invoke the corresponding overloaded operators if
503 ** New `Xmethods' feature in the Python API. Xmethods are
504 additional methods or replacements for existing methods of a C++
505 class. This feature is useful for those cases where a method
506 defined in C++ source code could be inlined or optimized out by
507 the compiler, making it unavailable to GDB.
510 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
512 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
513 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
514 its alias "share", instead.
516 * The commands "set remotebaud" and "show remotebaud" are no longer
517 supported. Use "set serial baud" and "show serial baud" (respectively)
522 ** A new option "-gdb-set mi-async" replaces "-gdb-set
523 target-async". The latter is left as a deprecated alias of the
524 former for backward compatibility. If the target supports it,
525 CLI background execution commands are now always possible by
526 default, independently of whether the frontend stated a
527 preference for asynchronous execution with "-gdb-set mi-async".
528 Previously "-gdb-set target-async off" affected both MI execution
529 commands and CLI execution commands.
531 *** Changes in GDB 7.7
533 * Improved support for process record-replay and reverse debugging on
534 arm*-linux* targets. Support for thumb32 and syscall instruction
535 recording has been added.
537 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
539 * GDB now supports Fission DWP file format version 2.
540 http://gcc.gnu.org/wiki/DebugFission
542 * New convenience function "$_isvoid", to check whether an expression
543 is void. A void expression is an expression where the type of the
544 result is "void". For example, some convenience variables may be
545 "void" when evaluated (e.g., "$_exitcode" before the execution of
546 the program being debugged; or an undefined convenience variable).
547 Another example, when calling a function whose return type is
550 * The "maintenance print objfiles" command now takes an optional regexp.
552 * The "catch syscall" command now works on arm*-linux* targets.
554 * GDB now consistently shows "<not saved>" when printing values of
555 registers the debug info indicates have not been saved in the frame
556 and there's nowhere to retrieve them from
557 (callee-saved/call-clobbered registers):
562 (gdb) info registers rax
565 Before, the former would print "<optimized out>", and the latter
566 "*value not available*".
568 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
573 ** Frame filters and frame decorators have been added.
574 ** Temporary breakpoints are now supported.
575 ** Line tables representation has been added.
576 ** New attribute 'parent_type' for gdb.Field objects.
577 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
578 ** New attribute 'name' for gdb.Type objects.
582 Nios II ELF nios2*-*-elf
583 Nios II GNU/Linux nios2*-*-linux
584 Texas Instruments MSP430 msp430*-*-elf
586 * Removed native configurations
588 Support for these a.out NetBSD and OpenBSD obsolete configurations has
589 been removed. ELF variants of these configurations are kept supported.
591 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
592 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
593 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
594 i[34567]86-*-openbsd3.[0-3]
595 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
596 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
597 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
601 Like "catch throw", but catches a re-thrown exception.
603 Renamed from old "maint check-symtabs".
605 Perform consistency checks on symtabs.
607 Expand symtabs matching an optional regexp.
610 Display the details of GDB configure-time options.
612 maint set|show per-command
613 maint set|show per-command space
614 maint set|show per-command time
615 maint set|show per-command symtab
616 Enable display of per-command gdb resource usage.
618 remove-symbol-file FILENAME
619 remove-symbol-file -a ADDRESS
620 Remove a symbol file added via add-symbol-file. The file to remove
621 can be identified by its filename or by an address that lies within
622 the boundaries of this symbol file in memory.
625 info exceptions REGEXP
626 Display the list of Ada exceptions defined in the program being
627 debugged. If provided, only the exceptions whose names match REGEXP
632 set debug symfile off|on
634 Control display of debugging info regarding reading symbol files and
635 symbol tables within those files
637 set print raw frame-arguments
638 show print raw frame-arguments
639 Set/show whether to print frame arguments in raw mode,
640 disregarding any defined pretty-printers.
642 set remote trace-status-packet
643 show remote trace-status-packet
644 Set/show the use of remote protocol qTStatus packet.
648 Control display of debugging messages related to Nios II targets.
652 Control whether target-assisted range stepping is enabled.
654 set startup-with-shell
655 show startup-with-shell
656 Specifies whether Unix child processes are started via a shell or
661 Use the target memory cache for accesses to the code segment. This
662 improves performance of remote debugging (particularly disassembly).
664 * You can now use a literal value 'unlimited' for options that
665 interpret 0 or -1 as meaning "unlimited". E.g., "set
666 trace-buffer-size unlimited" is now an alias for "set
667 trace-buffer-size -1" and "set height unlimited" is now an alias for
670 * The "set debug symtab-create" debugging option of GDB has been changed to
671 accept a verbosity level. 0 means "off", 1 provides basic debugging
672 output, and values of 2 or greater provides more verbose output.
674 * New command-line options
676 Display the details of GDB configure-time options.
678 * The command 'tsave' can now support new option '-ctf' to save trace
679 buffer in Common Trace Format.
681 * Newly installed $prefix/bin/gcore acts as a shell interface for the
684 * GDB now implements the the C++ 'typeid' operator.
686 * The new convenience variable $_exception holds the exception being
687 thrown or caught at an exception-related catchpoint.
689 * The exception-related catchpoints, like "catch throw", now accept a
690 regular expression which can be used to filter exceptions by type.
692 * The new convenience variable $_exitsignal is automatically set to
693 the terminating signal number when the program being debugged dies
694 due to an uncaught signal.
698 ** All MI commands now accept an optional "--language" option.
699 Support for this feature can be verified by using the "-list-features"
700 command, which should contain "language-option".
702 ** The new command -info-gdb-mi-command allows the user to determine
703 whether a GDB/MI command is supported or not.
705 ** The "^error" result record returned when trying to execute an undefined
706 GDB/MI command now provides a variable named "code" whose content is the
707 "undefined-command" error code. Support for this feature can be verified
708 by using the "-list-features" command, which should contain
709 "undefined-command-error-code".
711 ** The -trace-save MI command can optionally save trace buffer in Common
714 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
716 ** The command -data-list-register-values now accepts an optional
717 "--skip-unavailable" option. When used, only the available registers
720 ** The new command -trace-frame-collected dumps collected variables,
721 computed expressions, tvars, memory and registers in a traceframe.
723 ** The commands -stack-list-locals, -stack-list-arguments and
724 -stack-list-variables now accept an option "--skip-unavailable".
725 When used, only the available locals or arguments are displayed.
727 ** The -exec-run command now accepts an optional "--start" option.
728 When used, the command follows the same semantics as the "start"
729 command, stopping the program's execution at the start of its
730 main subprogram. Support for this feature can be verified using
731 the "-list-features" command, which should contain
732 "exec-run-start-option".
734 ** The new commands -catch-assert and -catch-exceptions insert
735 catchpoints stopping the program when Ada exceptions are raised.
737 ** The new command -info-ada-exceptions provides the equivalent of
738 the new "info exceptions" command.
740 * New system-wide configuration scripts
741 A GDB installation now provides scripts suitable for use as system-wide
742 configuration scripts for the following systems:
746 * GDB now supports target-assigned range stepping with remote targets.
747 This improves the performance of stepping source lines by reducing
748 the number of control packets from/to GDB. See "New remote packets"
751 * GDB now understands the element 'tvar' in the XML traceframe info.
752 It has the id of the collected trace state variables.
754 * On S/390 targets that provide the transactional-execution feature,
755 the program interruption transaction diagnostic block (TDB) is now
756 represented as a number of additional "registers" in GDB.
762 The vCont packet supports a new 'r' action, that tells the remote
763 stub to step through an address range itself, without GDB
764 involvemement at each single-step.
766 qXfer:libraries-svr4:read's annex
767 The previously unused annex of the qXfer:libraries-svr4:read packet
768 is now used to support passing an argument list. The remote stub
769 reports support for this argument list to GDB's qSupported query.
770 The defined arguments are "start" and "prev", used to reduce work
771 necessary for library list updating, resulting in significant
774 * New features in the GDB remote stub, GDBserver
776 ** GDBserver now supports target-assisted range stepping. Currently
777 enabled on x86/x86_64 GNU/Linux targets.
779 ** GDBserver now adds element 'tvar' in the XML in the reply to
780 'qXfer:traceframe-info:read'. It has the id of the collected
781 trace state variables.
783 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
786 * New 'z' formatter for printing and examining memory, this displays the
787 value as hexadecimal zero padded on the left to the size of the type.
789 * GDB can now use Windows x64 unwinding data.
791 * The "set remotebaud" command has been replaced by "set serial baud".
792 Similarly, "show remotebaud" has been replaced by "show serial baud".
793 The "set remotebaud" and "show remotebaud" commands are still available
794 to provide backward compatibility with older versions of GDB.
796 *** Changes in GDB 7.6
798 * Target record has been renamed to record-full.
799 Record/replay is now enabled with the "record full" command.
800 This also affects settings that are associated with full record/replay
801 that have been moved from "set/show record" to "set/show record full":
803 set|show record full insn-number-max
804 set|show record full stop-at-limit
805 set|show record full memory-query
807 * A new record target "record-btrace" has been added. The new target
808 uses hardware support to record the control-flow of a process. It
809 does not support replaying the execution, but it implements the
810 below new commands for investigating the recorded execution log.
811 This new recording method can be enabled using:
815 The "record-btrace" target is only available on Intel Atom processors
816 and requires a Linux kernel 2.6.32 or later.
818 * Two new commands have been added for record/replay to give information
819 about the recorded execution without having to replay the execution.
820 The commands are only supported by "record btrace".
822 record instruction-history prints the execution history at
823 instruction granularity
825 record function-call-history prints the execution history at
828 * New native configurations
830 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
831 FreeBSD/powerpc powerpc*-*-freebsd
832 x86_64/Cygwin x86_64-*-cygwin*
833 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
837 ARM AArch64 aarch64*-*-elf
838 ARM AArch64 GNU/Linux aarch64*-*-linux
839 Lynx 178 PowerPC powerpc-*-lynx*178
840 x86_64/Cygwin x86_64-*-cygwin*
841 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
843 * If the configured location of system.gdbinit file (as given by the
844 --with-system-gdbinit option at configure time) is in the
845 data-directory (as specified by --with-gdb-datadir at configure
846 time) or in one of its subdirectories, then GDB will look for the
847 system-wide init file in the directory specified by the
848 --data-directory command-line option.
850 * New command line options:
852 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
853 other initialization files, unlike -nx which disables all of them.
855 * Removed command line options
857 -epoch This was used by the gdb mode in Epoch, an ancient fork of
860 * The 'ptype' and 'whatis' commands now accept an argument to control
863 * 'info proc' now works on some core files.
867 ** Vectors can be created with gdb.Type.vector.
869 ** Python's atexit.register now works in GDB.
871 ** Types can be pretty-printed via a Python API.
873 ** Python 3 is now supported (in addition to Python 2.4 or later)
875 ** New class gdb.Architecture exposes GDB's internal representation
876 of architecture in the Python API.
878 ** New method Frame.architecture returns the gdb.Architecture object
879 corresponding to the frame's architecture.
881 * New Python-based convenience functions:
883 ** $_memeq(buf1, buf2, length)
884 ** $_streq(str1, str2)
886 ** $_regex(str, regex)
888 * The 'cd' command now defaults to using '~' (the home directory) if not
891 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
892 default for GCC since November 2000.
894 * The command 'forward-search' can now be abbreviated as 'fo'.
896 * The command 'info tracepoints' can now display 'installed on target'
897 or 'not installed on target' for each non-pending location of tracepoint.
899 * New configure options
901 --enable-libmcheck/--disable-libmcheck
902 By default, development versions are built with -lmcheck on hosts
903 that support it, in order to help track memory corruption issues.
904 Release versions, on the other hand, are built without -lmcheck
905 by default. The --enable-libmcheck/--disable-libmcheck configure
906 options allow the user to override that default.
907 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
908 This configure option allows the user to build GDB with
909 libbabeltrace using which GDB can read Common Trace Format data.
911 * New commands (for set/show, see "New options" below)
914 Catch signals. This is similar to "handle", but allows commands and
915 conditions to be attached.
918 List the BFDs known to GDB.
920 python-interactive [command]
922 Start a Python interactive prompt, or evaluate the optional command
923 and print the result of expressions.
926 "py" is a new alias for "python".
928 enable type-printer [name]...
929 disable type-printer [name]...
930 Enable or disable type printers.
934 ** For the Renesas Super-H architecture, the "regs" command has been removed
935 (has been deprecated in GDB 7.5), and "info all-registers" should be used
940 set print type methods (on|off)
941 show print type methods
942 Control whether method declarations are displayed by "ptype".
943 The default is to show them.
945 set print type typedefs (on|off)
946 show print type typedefs
947 Control whether typedef definitions are displayed by "ptype".
948 The default is to show them.
950 set filename-display basename|relative|absolute
951 show filename-display
952 Control the way in which filenames is displayed.
953 The default is "relative", which preserves previous behavior.
955 set trace-buffer-size
956 show trace-buffer-size
957 Request target to change the size of trace buffer.
959 set remote trace-buffer-size-packet auto|on|off
960 show remote trace-buffer-size-packet
961 Control the use of the remote protocol `QTBuffer:size' packet.
965 Control display of debugging messages related to ARM AArch64.
968 set debug coff-pe-read
969 show debug coff-pe-read
970 Control display of debugging messages related to reading of COFF/PE
975 Control display of debugging messages related to Mach-O symbols
978 set debug notification
979 show debug notification
980 Control display of debugging info for async remote notification.
984 ** Command parameter changes are now notified using new async record
985 "=cmd-param-changed".
986 ** Trace frame changes caused by command "tfind" are now notified using
987 new async record "=traceframe-changed".
988 ** The creation, deletion and modification of trace state variables
989 are now notified using new async records "=tsv-created",
990 "=tsv-deleted" and "=tsv-modified".
991 ** The start and stop of process record are now notified using new
992 async record "=record-started" and "=record-stopped".
993 ** Memory changes are now notified using new async record
995 ** The data-disassemble command response will include a "fullname" field
996 containing the absolute file name when source has been requested.
997 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
998 command, to allow pattern filling of memory areas.
999 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1000 library load/unload events.
1001 ** The response to breakpoint commands and breakpoint async records
1002 includes an "installed" field containing a boolean state about each
1003 non-pending tracepoint location is whether installed on target or not.
1004 ** Output of the "-trace-status" command includes a "trace-file" field
1005 containing the name of the trace file being examined. This field is
1006 optional, and only present when examining a trace file.
1007 ** The "fullname" field is now always present along with the "file" field,
1008 even if the file cannot be found by GDB.
1010 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1011 You must have the LZMA library available when configuring GDB for this
1012 feature to be enabled. For more information, see:
1013 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1015 * New remote packets
1018 Set the size of trace buffer. The remote stub reports support for this
1019 packet to gdb's qSupported query.
1022 Enable Branch Trace Store (BTS)-based branch tracing for the current
1023 thread. The remote stub reports support for this packet to gdb's
1027 Disable branch tracing for the current thread. The remote stub reports
1028 support for this packet to gdb's qSupported query.
1031 Read the traced branches for the current thread. The remote stub
1032 reports support for this packet to gdb's qSupported query.
1034 *** Changes in GDB 7.5
1036 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1037 for more x32 ABI info.
1039 * GDB now supports access to MIPS DSP registers on Linux targets.
1041 * GDB now supports debugging microMIPS binaries.
1043 * The "info os" command on GNU/Linux can now display information on
1044 several new classes of objects managed by the operating system:
1045 "info os procgroups" lists process groups
1046 "info os files" lists file descriptors
1047 "info os sockets" lists internet-domain sockets
1048 "info os shm" lists shared-memory regions
1049 "info os semaphores" lists semaphores
1050 "info os msg" lists message queues
1051 "info os modules" lists loaded kernel modules
1053 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1054 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1055 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1056 options and inspect the probe arguments using the new $_probe_arg family
1057 of convenience variables. You can obtain more information about SystemTap
1058 in <http://sourceware.org/systemtap/>.
1060 * GDB now supports reversible debugging on ARM, it allows you to
1061 debug basic ARM and THUMB instructions, and provides
1062 record/replay support.
1064 * The option "symbol-reloading" has been deleted as it is no longer used.
1068 ** GDB commands implemented in Python can now be put in command class
1071 ** The "maint set python print-stack on|off" is now deleted.
1073 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1074 apply "flag enum"-style pretty-printing to any enum.
1076 ** gdb.lookup_symbol can now work when there is no current frame.
1078 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1079 the source at which the symbol was defined.
1081 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1082 method 'value'. The former indicates whether the symbol needs a
1083 frame in order to compute its value, and the latter computes the
1086 ** A new method 'referenced_value' on gdb.Value objects which can
1087 dereference pointer as well as C++ reference values.
1089 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1090 which return the global and static blocks (as gdb.Block objects),
1091 of the underlying symbol table, respectively.
1093 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1094 object associated with a PC value.
1096 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1097 of the address range occupied by code for the current source line.
1099 * Go language support.
1100 GDB now supports debugging programs written in the Go programming
1103 * GDBserver now supports stdio connections.
1104 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1106 * The binary "gdbtui" can no longer be built or installed.
1107 Use "gdb -tui" instead.
1109 * GDB will now print "flag" enums specially. A flag enum is one where
1110 all the enumerator values have no bits in common when pairwise
1111 "and"ed. When printing a value whose type is a flag enum, GDB will
1112 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1113 (gdb) print (enum E) 3
1116 * The filename part of a linespec will now match trailing components
1117 of a source file name. For example, "break gcc/expr.c:1000" will
1118 now set a breakpoint in build/gcc/expr.c, but not
1119 build/libcpp/expr.c.
1121 * The "info proc" and "generate-core-file" commands will now also
1122 work on remote targets connected to GDBserver on Linux.
1124 * The command "info catch" has been removed. It has been disabled
1125 since December 2007.
1127 * The "catch exception" and "catch assert" commands now accept
1128 a condition at the end of the command, much like the "break"
1129 command does. For instance:
1131 (gdb) catch exception Constraint_Error if Barrier = True
1133 Previously, it was possible to add a condition to such catchpoints,
1134 but it had to be done as a second step, after the catchpoint had been
1135 created, using the "condition" command.
1137 * The "info static-tracepoint-marker" command will now also work on
1138 native Linux targets with in-process agent.
1140 * GDB can now set breakpoints on inlined functions.
1142 * The .gdb_index section has been updated to include symbols for
1143 inlined functions. GDB will ignore older .gdb_index sections by
1144 default, which could cause symbol files to be loaded more slowly
1145 until their .gdb_index sections can be recreated. The new command
1146 "set use-deprecated-index-sections on" will cause GDB to use any older
1147 .gdb_index sections it finds. This will restore performance, but the
1148 ability to set breakpoints on inlined functions will be lost in symbol
1149 files with older .gdb_index sections.
1151 The .gdb_index section has also been updated to record more information
1152 about each symbol. This speeds up the "info variables", "info functions"
1153 and "info types" commands when used with programs having the .gdb_index
1154 section, as well as speeding up debugging with shared libraries using
1155 the .gdb_index section.
1157 * Ada support for GDB/MI Variable Objects has been added.
1159 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1164 ** New command -info-os is the MI equivalent of "info os".
1166 ** Output logs ("set logging" and related) now include MI output.
1170 ** "set use-deprecated-index-sections on|off"
1171 "show use-deprecated-index-sections on|off"
1172 Controls the use of deprecated .gdb_index sections.
1174 ** "catch load" and "catch unload" can be used to stop when a shared
1175 library is loaded or unloaded, respectively.
1177 ** "enable count" can be used to auto-disable a breakpoint after
1180 ** "info vtbl" can be used to show the virtual method tables for
1181 C++ and Java objects.
1183 ** "explore" and its sub commands "explore value" and "explore type"
1184 can be used to recursively explore values and types of
1185 expressions. These commands are available only if GDB is
1186 configured with '--with-python'.
1188 ** "info auto-load" shows status of all kinds of auto-loaded files,
1189 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1190 sequences of commands files, "info auto-load python-scripts"
1191 shows status of auto-loading Python script files,
1192 "info auto-load local-gdbinit" shows status of loading init file
1193 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1194 status of inferior specific thread debugging shared library loading.
1196 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1197 and "show auto-load-scripts" commands have been deprecated, use their
1198 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1199 and "show auto-load python-scripts" counterparts instead.
1201 ** "dprintf location,format,args..." creates a dynamic printf, which
1202 is basically a breakpoint that does a printf and immediately
1203 resumes your program's execution, so it is like a printf that you
1204 can insert dynamically at runtime instead of at compiletime.
1206 ** "set print symbol"
1208 Controls whether GDB attempts to display the symbol, if any,
1209 corresponding to addresses it prints. This defaults to "on", but
1210 you can set it to "off" to restore GDB's previous behavior.
1212 * Deprecated commands
1214 ** For the Renesas Super-H architecture, the "regs" command has been
1215 deprecated, and "info all-registers" should be used instead.
1219 Renesas RL78 rl78-*-elf
1220 HP OpenVMS ia64 ia64-hp-openvms*
1222 * GDBserver supports evaluation of breakpoint conditions. When
1223 support is advertised by GDBserver, GDB may be told to send the
1224 breakpoint conditions in bytecode form to GDBserver. GDBserver
1225 will only report the breakpoint trigger to GDB when its condition
1230 set mips compression
1231 show mips compression
1232 Select the compressed ISA encoding used in functions that have no symbol
1233 information available. The encoding can be set to either of:
1236 and is updated automatically from ELF file flags if available.
1238 set breakpoint condition-evaluation
1239 show breakpoint condition-evaluation
1240 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1241 GDBserver ("target"). Default option "auto" chooses the most efficient
1243 This option can improve debugger efficiency depending on the speed of the
1247 Disable auto-loading globally.
1250 Show auto-loading setting of all kinds of auto-loaded files.
1252 set auto-load gdb-scripts on|off
1253 show auto-load gdb-scripts
1254 Control auto-loading of GDB canned sequences of commands files.
1256 set auto-load python-scripts on|off
1257 show auto-load python-scripts
1258 Control auto-loading of Python script files.
1260 set auto-load local-gdbinit on|off
1261 show auto-load local-gdbinit
1262 Control loading of init file (.gdbinit) from current directory.
1264 set auto-load libthread-db on|off
1265 show auto-load libthread-db
1266 Control auto-loading of inferior specific thread debugging shared library.
1268 set auto-load scripts-directory <dir1>[:<dir2>...]
1269 show auto-load scripts-directory
1270 Set a list of directories from which to load auto-loaded scripts.
1271 Automatically loaded Python scripts and GDB scripts are located in one
1272 of the directories listed by this option.
1273 The delimiter (':' above) may differ according to the host platform.
1275 set auto-load safe-path <dir1>[:<dir2>...]
1276 show auto-load safe-path
1277 Set a list of directories from which it is safe to auto-load files.
1278 The delimiter (':' above) may differ according to the host platform.
1280 set debug auto-load on|off
1281 show debug auto-load
1282 Control display of debugging info for auto-loading the files above.
1284 set dprintf-style gdb|call|agent
1286 Control the way in which a dynamic printf is performed; "gdb"
1287 requests a GDB printf command, while "call" causes dprintf to call a
1288 function in the inferior. "agent" requests that the target agent
1289 (such as GDBserver) do the printing.
1291 set dprintf-function <expr>
1292 show dprintf-function
1293 set dprintf-channel <expr>
1294 show dprintf-channel
1295 Set the function and optional first argument to the call when using
1296 the "call" style of dynamic printf.
1298 set disconnected-dprintf on|off
1299 show disconnected-dprintf
1300 Control whether agent-style dynamic printfs continue to be in effect
1301 after GDB disconnects.
1303 * New configure options
1305 --with-auto-load-dir
1306 Configure default value for the 'set auto-load scripts-directory'
1307 setting above. It defaults to '$debugdir:$datadir/auto-load',
1308 $debugdir representing global debugging info directories (available
1309 via 'show debug-file-directory') and $datadir representing GDB's data
1310 directory (available via 'show data-directory').
1312 --with-auto-load-safe-path
1313 Configure default value for the 'set auto-load safe-path' setting
1314 above. It defaults to the --with-auto-load-dir setting.
1316 --without-auto-load-safe-path
1317 Set 'set auto-load safe-path' to '/', effectively disabling this
1320 * New remote packets
1322 z0/z1 conditional breakpoints extension
1324 The z0/z1 breakpoint insertion packets have been extended to carry
1325 a list of conditional expressions over to the remote stub depending on the
1326 condition evaluation mode. The use of this extension can be controlled
1327 via the "set remote conditional-breakpoints-packet" command.
1331 Specify the signals which the remote stub may pass to the debugged
1332 program without GDB involvement.
1334 * New command line options
1336 --init-command=FILE, -ix Like --command, -x but execute it
1337 before loading inferior.
1338 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1339 execute it before loading inferior.
1341 *** Changes in GDB 7.4
1343 * GDB now handles ambiguous linespecs more consistently; the existing
1344 FILE:LINE support has been expanded to other types of linespecs. A
1345 breakpoint will now be set on all matching locations in all
1346 inferiors, and locations will be added or removed according to
1349 * GDB now allows you to skip uninteresting functions and files when
1350 stepping with the "skip function" and "skip file" commands.
1352 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1353 and "show remote hardware-watchpoint-length-limit". These allows to
1354 set or show the maximum length limit (in bytes) of a remote
1355 target hardware watchpoint.
1357 This allows e.g. to use "unlimited" hardware watchpoints with the
1358 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1359 watchpoints are slower than real hardware watchpoints but are
1360 significantly faster than gdb software watchpoints.
1364 ** The register_pretty_printer function in module gdb.printing now takes
1365 an optional `replace' argument. If True, the new printer replaces any
1368 ** The "maint set python print-stack on|off" command has been
1369 deprecated and will be deleted in GDB 7.5.
1370 A new command: "set python print-stack none|full|message" has
1371 replaced it. Additionally, the default for "print-stack" is
1372 now "message", which just prints the error message without
1375 ** A prompt substitution hook (prompt_hook) is now available to the
1378 ** A new Python module, gdb.prompt has been added to the GDB Python
1379 modules library. This module provides functionality for
1380 escape sequences in prompts (used by set/show
1381 extended-prompt). These escape sequences are replaced by their
1382 corresponding value.
1384 ** Python commands and convenience-functions located in
1385 'data-directory'/python/gdb/command and
1386 'data-directory'/python/gdb/function are now automatically loaded
1389 ** Blocks now provide four new attributes. global_block and
1390 static_block will return the global and static blocks
1391 respectively. is_static and is_global are boolean attributes
1392 that indicate if the block is one of those two types.
1394 ** Symbols now provide the "type" attribute, the type of the symbol.
1396 ** The "gdb.breakpoint" function has been deprecated in favor of
1399 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1400 of a function. This class is based on the "finish" command
1401 available in the CLI.
1403 ** Type objects for struct and union types now allow access to
1404 the fields using standard Python dictionary (mapping) methods.
1405 For example, "some_type['myfield']" now works, as does
1406 "some_type.items()".
1408 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1411 ** A new function, "deep_items" has been added to the gdb.types
1412 module in the GDB Python modules library. This function returns
1413 an iterator over the fields of a struct or union type. Unlike
1414 the standard Python "iteritems" method, it will recursively traverse
1415 any anonymous fields.
1419 ** "*stopped" events can report several new "reason"s, such as
1422 ** Breakpoint changes are now notified using new async records, like
1423 "=breakpoint-modified".
1425 ** New command -ada-task-info.
1427 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1428 $sdir specifies the default system locations of shared libraries.
1429 $pdir specifies the directory where the libpthread used by the application
1432 GDB no longer looks in $sdir and $pdir after it has searched the directories
1433 mentioned in libthread-db-search-path. If you want to search those
1434 directories, they must be specified in libthread-db-search-path.
1435 The default value of libthread-db-search-path on GNU/Linux and Solaris
1436 systems is now "$sdir:$pdir".
1438 $pdir is not supported by gdbserver, it is currently ignored.
1439 $sdir is supported by gdbserver.
1441 * New configure option --with-iconv-bin.
1442 When using the internationalization support like the one in the GNU C
1443 library, GDB will invoke the "iconv" program to get a list of supported
1444 character sets. If this program lives in a non-standard location, one can
1445 use this option to specify where to find it.
1447 * When natively debugging programs on PowerPC BookE processors running
1448 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1449 watchpoints, which specify a mask in addition to an address to watch.
1450 The mask specifies that some bits of an address (the bits which are
1451 reset in the mask) should be ignored when matching the address accessed
1452 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1453 section in the user manual for more details.
1455 * The new option --once causes GDBserver to stop listening for connections once
1456 the first connection is made. The listening port used by GDBserver will
1457 become available after that.
1459 * New commands "info macros" and "alias" have been added.
1461 * New function parameters suffix @entry specifies value of function parameter
1462 at the time the function got called. Entry values are available only since
1468 "!" is now an alias of the "shell" command.
1469 Note that no space is needed between "!" and SHELL COMMAND.
1473 watch EXPRESSION mask MASK_VALUE
1474 The watch command now supports the mask argument which allows creation
1475 of masked watchpoints, if the current architecture supports this feature.
1477 info auto-load-scripts [REGEXP]
1478 This command was formerly named "maintenance print section-scripts".
1479 It is now generally useful and is no longer a maintenance-only command.
1481 info macro [-all] [--] MACRO
1482 The info macro command has new options `-all' and `--'. The first for
1483 printing all definitions of a macro. The second for explicitly specifying
1484 the end of arguments and the beginning of the macro name in case the macro
1485 name starts with a hyphen.
1487 collect[/s] EXPRESSIONS
1488 The tracepoint collect command now takes an optional modifier "/s"
1489 that directs it to dereference pointer-to-character types and
1490 collect the bytes of memory up to a zero byte. The behavior is
1491 similar to what you see when you use the regular print command on a
1492 string. An optional integer following the "/s" sets a bound on the
1493 number of bytes that will be collected.
1496 The trace start command now interprets any supplied arguments as a
1497 note to be recorded with the trace run, with an effect similar to
1498 setting the variable trace-notes.
1501 The trace stop command now interprets any arguments as a note to be
1502 mentioned along with the tstatus report that the trace was stopped
1503 with a command. The effect is similar to setting the variable
1506 * Tracepoints can now be enabled and disabled at any time after a trace
1507 experiment has been started using the standard "enable" and "disable"
1508 commands. It is now possible to start a trace experiment with no enabled
1509 tracepoints; GDB will display a warning, but will allow the experiment to
1510 begin, assuming that tracepoints will be enabled as needed while the trace
1513 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1514 locations with 4-byte instructions, when they were previously
1515 limited to locations with instructions of 5 bytes or longer.
1519 set debug dwarf2-read
1520 show debug dwarf2-read
1521 Turns on or off display of debugging messages related to reading
1522 DWARF debug info. The default is off.
1524 set debug symtab-create
1525 show debug symtab-create
1526 Turns on or off display of debugging messages related to symbol table
1527 creation. The default is off.
1530 show extended-prompt
1531 Set the GDB prompt, and allow escape sequences to be inserted to
1532 display miscellaneous information (see 'help set extended-prompt'
1533 for the list of sequences). This prompt (and any information
1534 accessed through the escape sequences) is updated every time the
1535 prompt is displayed.
1537 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1538 show print entry-values
1539 Set printing of frame argument values at function entry. In some cases
1540 GDB can determine the value of function argument which was passed by the
1541 function caller, even if the value was modified inside the called function.
1543 set debug entry-values
1544 show debug entry-values
1545 Control display of debugging info for determining frame argument values at
1546 function entry and virtual tail call frames.
1548 set basenames-may-differ
1549 show basenames-may-differ
1550 Set whether a source file may have multiple base names.
1551 (A "base name" is the name of a file with the directory part removed.
1552 Example: The base name of "/home/user/hello.c" is "hello.c".)
1553 If set, GDB will canonicalize file names (e.g., expand symlinks)
1554 before comparing them. Canonicalization is an expensive operation,
1555 but it allows the same file be known by more than one base name.
1556 If not set (the default), all source files are assumed to have just
1557 one base name, and gdb will do file name comparisons more efficiently.
1563 Set a user name and notes for the current and any future trace runs.
1564 This is useful for long-running and/or disconnected traces, to
1565 inform others (or yourself) as to who is running the trace, supply
1566 contact information, or otherwise explain what is going on.
1568 set trace-stop-notes
1569 show trace-stop-notes
1570 Set a note attached to the trace run, that is displayed when the
1571 trace has been stopped by a tstop command. This is useful for
1572 instance as an explanation, if you are stopping a trace run that was
1573 started by someone else.
1575 * New remote packets
1579 Dynamically enable a tracepoint in a started trace experiment.
1583 Dynamically disable a tracepoint in a started trace experiment.
1587 Set the user and notes of the trace run.
1591 Query the current status of a tracepoint.
1595 Query the minimum length of instruction at which a fast tracepoint may
1598 * Dcache size (number of lines) and line-size are now runtime-configurable
1599 via "set dcache line" and "set dcache line-size" commands.
1603 Texas Instruments TMS320C6x tic6x-*-*
1607 Renesas RL78 rl78-*-elf
1609 *** Changes in GDB 7.3.1
1611 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1613 *** Changes in GDB 7.3
1615 * GDB has a new command: "thread find [REGEXP]".
1616 It finds the thread id whose name, target id, or thread extra info
1617 matches the given regular expression.
1619 * The "catch syscall" command now works on mips*-linux* targets.
1621 * The -data-disassemble MI command now supports modes 2 and 3 for
1622 dumping the instruction opcodes.
1624 * New command line options
1626 -data-directory DIR Specify DIR as the "data-directory".
1627 This is mostly for testing purposes.
1629 * The "maint set python auto-load on|off" command has been renamed to
1630 "set auto-load-scripts on|off".
1632 * GDB has a new command: "set directories".
1633 It is like the "dir" command except that it replaces the
1634 source path list instead of augmenting it.
1636 * GDB now understands thread names.
1638 On GNU/Linux, "info threads" will display the thread name as set by
1639 prctl or pthread_setname_np.
1641 There is also a new command, "thread name", which can be used to
1642 assign a name internally for GDB to display.
1645 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1646 has been integrated into GDB.
1650 ** The function gdb.Write now accepts an optional keyword 'stream'.
1651 This keyword, when provided, will direct the output to either
1652 stdout, stderr, or GDB's logging output.
1654 ** Parameters can now be be sub-classed in Python, and in particular
1655 you may implement the get_set_doc and get_show_doc functions.
1656 This improves how Parameter set/show documentation is processed
1657 and allows for more dynamic content.
1659 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1660 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1661 have an is_valid method.
1663 ** Breakpoints can now be sub-classed in Python, and in particular
1664 you may implement a 'stop' function that is executed each time
1665 the inferior reaches that breakpoint.
1667 ** New function gdb.lookup_global_symbol looks up a global symbol.
1669 ** GDB values in Python are now callable if the value represents a
1670 function. For example, if 'some_value' represents a function that
1671 takes two integer parameters and returns a value, you can call
1672 that function like so:
1674 result = some_value (10,20)
1676 ** Module gdb.types has been added.
1677 It contains a collection of utilities for working with gdb.Types objects:
1678 get_basic_type, has_field, make_enum_dict.
1680 ** Module gdb.printing has been added.
1681 It contains utilities for writing and registering pretty-printers.
1682 New classes: PrettyPrinter, SubPrettyPrinter,
1683 RegexpCollectionPrettyPrinter.
1684 New function: register_pretty_printer.
1686 ** New commands "info pretty-printers", "enable pretty-printer" and
1687 "disable pretty-printer" have been added.
1689 ** gdb.parameter("directories") is now available.
1691 ** New function gdb.newest_frame returns the newest frame in the
1694 ** The gdb.InferiorThread class has a new "name" attribute. This
1695 holds the thread's name.
1697 ** Python Support for Inferior events.
1698 Python scripts can add observers to be notified of events
1699 occurring in the process being debugged.
1700 The following events are currently supported:
1701 - gdb.events.cont Continue event.
1702 - gdb.events.exited Inferior exited event.
1703 - gdb.events.stop Signal received, and Breakpoint hit events.
1707 ** GDB now puts template parameters in scope when debugging in an
1708 instantiation. For example, if you have:
1710 template<int X> int func (void) { return X; }
1712 then if you step into func<5>, "print X" will show "5". This
1713 feature requires proper debuginfo support from the compiler; it
1714 was added to GCC 4.5.
1716 ** The motion commands "next", "finish", "until", and "advance" now
1717 work better when exceptions are thrown. In particular, GDB will
1718 no longer lose control of the inferior; instead, the GDB will
1719 stop the inferior at the point at which the exception is caught.
1720 This functionality requires a change in the exception handling
1721 code that was introduced in GCC 4.5.
1723 * GDB now follows GCC's rules on accessing volatile objects when
1724 reading or writing target state during expression evaluation.
1725 One notable difference to prior behavior is that "print x = 0"
1726 no longer generates a read of x; the value of the assignment is
1727 now always taken directly from the value being assigned.
1729 * GDB now has some support for using labels in the program's source in
1730 linespecs. For instance, you can use "advance label" to continue
1731 execution to a label.
1733 * GDB now has support for reading and writing a new .gdb_index
1734 section. This section holds a fast index of DWARF debugging
1735 information and can be used to greatly speed up GDB startup and
1736 operation. See the documentation for `save gdb-index' for details.
1738 * The "watch" command now accepts an optional "-location" argument.
1739 When used, this causes GDB to watch the memory referred to by the
1740 expression. Such a watchpoint is never deleted due to it going out
1743 * GDB now supports thread debugging of core dumps on GNU/Linux.
1745 GDB now activates thread debugging using the libthread_db library
1746 when debugging GNU/Linux core dumps, similarly to when debugging
1747 live processes. As a result, when debugging a core dump file, GDB
1748 is now able to display pthread_t ids of threads. For example, "info
1749 threads" shows the same output as when debugging the process when it
1750 was live. In earlier releases, you'd see something like this:
1753 * 1 LWP 6780 main () at main.c:10
1755 While now you see this:
1758 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1760 It is also now possible to inspect TLS variables when debugging core
1763 When debugging a core dump generated on a machine other than the one
1764 used to run GDB, you may need to point GDB at the correct
1765 libthread_db library with the "set libthread-db-search-path"
1766 command. See the user manual for more details on this command.
1768 * When natively debugging programs on PowerPC BookE processors running
1769 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1770 which stop execution of the inferior whenever it executes an instruction
1771 at any address within the specified range. See the "PowerPC Embedded"
1772 section in the user manual for more details.
1774 * New features in the GDB remote stub, GDBserver
1776 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1777 and i686 LynxOS (version 5.x).
1779 ** GDBserver is now supported on Blackfin Linux.
1781 * New native configurations
1783 ia64 HP-UX ia64-*-hpux*
1787 Analog Devices, Inc. Blackfin Processor bfin-*
1789 * Ada task switching is now supported on sparc-elf targets when
1790 debugging a program using the Ravenscar Profile. For more information,
1791 see the "Tasking Support when using the Ravenscar Profile" section
1792 in the GDB user manual.
1794 * Guile support was removed.
1796 * New features in the GNU simulator
1798 ** The --map-info flag lists all known core mappings.
1800 ** CFI flashes may be simulated via the "cfi" device.
1802 *** Changes in GDB 7.2
1804 * Shared library support for remote targets by default
1806 When GDB is configured for a generic, non-OS specific target, like
1807 for example, --target=arm-eabi or one of the many *-*-elf targets,
1808 GDB now queries remote stubs for loaded shared libraries using the
1809 `qXfer:libraries:read' packet. Previously, shared library support
1810 was always disabled for such configurations.
1814 ** Argument Dependent Lookup (ADL)
1816 In C++ ADL lookup directs function search to the namespaces of its
1817 arguments even if the namespace has not been imported.
1827 Here the compiler will search for `foo' in the namespace of 'b'
1828 and find A::foo. GDB now supports this. This construct is commonly
1829 used in the Standard Template Library for operators.
1831 ** Improved User Defined Operator Support
1833 In addition to member operators, GDB now supports lookup of operators
1834 defined in a namespace and imported with a `using' directive, operators
1835 defined in the global scope, operators imported implicitly from an
1836 anonymous namespace, and the ADL operators mentioned in the previous
1838 GDB now also supports proper overload resolution for all the previously
1839 mentioned flavors of operators.
1841 ** static const class members
1843 Printing of static const class members that are initialized in the
1844 class definition has been fixed.
1846 * Windows Thread Information Block access.
1848 On Windows targets, GDB now supports displaying the Windows Thread
1849 Information Block (TIB) structure. This structure is visible either
1850 by using the new command `info w32 thread-information-block' or, by
1851 dereferencing the new convenience variable named `$_tlb', a
1852 thread-specific pointer to the TIB. This feature is also supported
1853 when remote debugging using GDBserver.
1855 * Static tracepoints
1857 Static tracepoints are calls in the user program into a tracing
1858 library. One such library is a port of the LTTng kernel tracer to
1859 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1860 When debugging with GDBserver, GDB now supports combining the GDB
1861 tracepoint machinery with such libraries. For example: the user can
1862 use GDB to probe a static tracepoint marker (a call from the user
1863 program into the tracing library) with the new "strace" command (see
1864 "New commands" below). This creates a "static tracepoint" in the
1865 breakpoint list, that can be manipulated with the same feature set
1866 as fast and regular tracepoints. E.g., collect registers, local and
1867 global variables, collect trace state variables, and define
1868 tracepoint conditions. In addition, the user can collect extra
1869 static tracepoint marker specific data, by collecting the new
1870 $_sdata internal variable. When analyzing the trace buffer, you can
1871 inspect $_sdata like any other variable available to GDB. For more
1872 information, see the "Tracepoints" chapter in GDB user manual. New
1873 remote packets have been defined to support static tracepoints, see
1874 the "New remote packets" section below.
1876 * Better reconstruction of tracepoints after disconnected tracing
1878 GDB will attempt to download the original source form of tracepoint
1879 definitions when starting a trace run, and then will upload these
1880 upon reconnection to the target, resulting in a more accurate
1881 reconstruction of the tracepoints that are in use on the target.
1885 You can now exercise direct control over the ways that GDB can
1886 affect your program. For instance, you can disallow the setting of
1887 breakpoints, so that the program can run continuously (assuming
1888 non-stop mode). In addition, the "observer" variable is available
1889 to switch all of the different controls; in observer mode, GDB
1890 cannot affect the target's behavior at all, which is useful for
1891 tasks like diagnosing live systems in the field.
1893 * The new convenience variable $_thread holds the number of the
1896 * New remote packets
1900 Return the address of the Windows Thread Information Block of a given thread.
1904 In response to several of the tracepoint packets, the target may now
1905 also respond with a number of intermediate `qRelocInsn' request
1906 packets before the final result packet, to have GDB handle
1907 relocating an instruction to execute at a different address. This
1908 is particularly useful for stubs that support fast tracepoints. GDB
1909 reports support for this feature in the qSupported packet.
1913 List static tracepoint markers in the target program.
1917 List static tracepoint markers at a given address in the target
1920 qXfer:statictrace:read
1922 Read the static trace data collected (by a `collect $_sdata'
1923 tracepoint action). The remote stub reports support for this packet
1924 to gdb's qSupported query.
1928 Send the current settings of GDB's permission flags.
1932 Send part of the source (textual) form of a tracepoint definition,
1933 which includes location, conditional, and action list.
1935 * The source command now accepts a -s option to force searching for the
1936 script in the source search path even if the script name specifies
1939 * New features in the GDB remote stub, GDBserver
1941 - GDBserver now support tracepoints (including fast tracepoints, and
1942 static tracepoints). The feature is currently supported by the
1943 i386-linux and amd64-linux builds. See the "Tracepoints support
1944 in gdbserver" section in the manual for more information.
1946 GDBserver JIT compiles the tracepoint's conditional agent
1947 expression bytecode into native code whenever possible for low
1948 overhead dynamic tracepoints conditionals. For such tracepoints,
1949 an expression that examines program state is evaluated when the
1950 tracepoint is reached, in order to determine whether to capture
1951 trace data. If the condition is simple and false, processing the
1952 tracepoint finishes very quickly and no data is gathered.
1954 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1955 for static tracepoints support.
1957 - GDBserver now supports x86_64 Windows 64-bit debugging.
1959 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1960 it understands register description.
1962 * The --batch flag now disables pagination and queries.
1964 * X86 general purpose registers
1966 GDB now supports reading/writing byte, word and double-word x86
1967 general purpose registers directly. This means you can use, say,
1968 $ah or $ax to refer, respectively, to the byte register AH and
1969 16-bit word register AX that are actually portions of the 32-bit
1970 register EAX or 64-bit register RAX.
1972 * The `commands' command now accepts a range of breakpoints to modify.
1973 A plain `commands' following a command that creates multiple
1974 breakpoints affects all the breakpoints set by that command. This
1975 applies to breakpoints set by `rbreak', and also applies when a
1976 single `break' command creates multiple breakpoints (e.g.,
1977 breakpoints on overloaded c++ functions).
1979 * The `rbreak' command now accepts a filename specification as part of
1980 its argument, limiting the functions selected by the regex to those
1981 in the specified file.
1983 * Support for remote debugging Windows and SymbianOS shared libraries
1984 from Unix hosts has been improved. Non Windows GDB builds now can
1985 understand target reported file names that follow MS-DOS based file
1986 system semantics, such as file names that include drive letters and
1987 use the backslash character as directory separator. This makes it
1988 possible to transparently use the "set sysroot" and "set
1989 solib-search-path" on Unix hosts to point as host copies of the
1990 target's shared libraries. See the new command "set
1991 target-file-system-kind" described below, and the "Commands to
1992 specify files" section in the user manual for more information.
1996 eval template, expressions...
1997 Convert the values of one or more expressions under the control
1998 of the string template to a command line, and call it.
2000 set target-file-system-kind unix|dos-based|auto
2001 show target-file-system-kind
2002 Set or show the assumed file system kind for target reported file
2005 save breakpoints <filename>
2006 Save all current breakpoint definitions to a file suitable for use
2007 in a later debugging session. To read the saved breakpoint
2008 definitions, use the `source' command.
2010 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2013 info static-tracepoint-markers
2014 Display information about static tracepoint markers in the target.
2016 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2017 Define a static tracepoint by probing a marker at the given
2018 function, line, address, or marker ID.
2022 Enable and disable observer mode.
2024 set may-write-registers on|off
2025 set may-write-memory on|off
2026 set may-insert-breakpoints on|off
2027 set may-insert-tracepoints on|off
2028 set may-insert-fast-tracepoints on|off
2029 set may-interrupt on|off
2030 Set individual permissions for GDB effects on the target. Note that
2031 some of these settings can have undesirable or surprising
2032 consequences, particularly when changed in the middle of a session.
2033 For instance, disabling the writing of memory can prevent
2034 breakpoints from being inserted, cause single-stepping to fail, or
2035 even crash your program, if you disable after breakpoints have been
2036 inserted. However, GDB should not crash.
2038 set record memory-query on|off
2039 show record memory-query
2040 Control whether to stop the inferior if memory changes caused
2041 by an instruction cannot be recorded.
2046 The disassemble command now supports "start,+length" form of two arguments.
2050 ** GDB now provides a new directory location, called the python directory,
2051 where Python scripts written for GDB can be installed. The location
2052 of that directory is <data-directory>/python, where <data-directory>
2053 is the GDB data directory. For more details, see section `Scripting
2054 GDB using Python' in the manual.
2056 ** The GDB Python API now has access to breakpoints, symbols, symbol
2057 tables, program spaces, inferiors, threads and frame's code blocks.
2058 Additionally, GDB Parameters can now be created from the API, and
2059 manipulated via set/show in the CLI.
2061 ** New functions gdb.target_charset, gdb.target_wide_charset,
2062 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2064 ** New exception gdb.GdbError.
2066 ** Pretty-printers are now also looked up in the current program space.
2068 ** Pretty-printers can now be individually enabled and disabled.
2070 ** GDB now looks for names of Python scripts to auto-load in a
2071 special section named `.debug_gdb_scripts', in addition to looking
2072 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2074 * Tracepoint actions were unified with breakpoint commands. In particular,
2075 there are no longer differences in "info break" output for breakpoints and
2076 tracepoints and the "commands" command can be used for both tracepoints and
2077 regular breakpoints.
2081 ARM Symbian arm*-*-symbianelf*
2083 * D language support.
2084 GDB now supports debugging programs written in the D programming
2087 * GDB now supports the extended ptrace interface for PowerPC which is
2088 available since Linux kernel version 2.6.34. This automatically enables
2089 any hardware breakpoints and additional hardware watchpoints available in
2090 the processor. The old ptrace interface exposes just one hardware
2091 watchpoint and no hardware breakpoints.
2093 * GDB is now able to use the Data Value Compare (DVC) register available on
2094 embedded PowerPC processors to implement in hardware simple watchpoint
2095 conditions of the form:
2097 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2099 This works in native GDB running on Linux kernels with the extended ptrace
2100 interface mentioned above.
2102 *** Changes in GDB 7.1
2106 ** Namespace Support
2108 GDB now supports importing of namespaces in C++. This enables the
2109 user to inspect variables from imported namespaces. Support for
2110 namepace aliasing has also been added. So, if a namespace is
2111 aliased in the current scope (e.g. namepace C=A; ) the user can
2112 print variables using the alias (e.g. (gdb) print C::x).
2116 All known bugs relating to the printing of virtual base class were
2117 fixed. It is now possible to call overloaded static methods using a
2122 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2123 and reinterpret_cast<> are now handled by the C++ expression parser.
2127 Xilinx MicroBlaze microblaze-*-*
2132 Xilinx MicroBlaze microblaze
2135 * Multi-program debugging.
2137 GDB now has support for multi-program (a.k.a. multi-executable or
2138 multi-exec) debugging. This allows for debugging multiple inferiors
2139 simultaneously each running a different program under the same GDB
2140 session. See "Debugging Multiple Inferiors and Programs" in the
2141 manual for more information. This implied some user visible changes
2142 in the multi-inferior support. For example, "info inferiors" now
2143 lists inferiors that are not running yet or that have exited
2144 already. See also "New commands" and "New options" below.
2146 * New tracing features
2148 GDB's tracepoint facility now includes several new features:
2150 ** Trace state variables
2152 GDB tracepoints now include support for trace state variables, which
2153 are variables managed by the target agent during a tracing
2154 experiment. They are useful for tracepoints that trigger each
2155 other, so for instance one tracepoint can count hits in a variable,
2156 and then a second tracepoint has a condition that is true when the
2157 count reaches a particular value. Trace state variables share the
2158 $-syntax of GDB convenience variables, and can appear in both
2159 tracepoint actions and condition expressions. Use the "tvariable"
2160 command to create, and "info tvariables" to view; see "Trace State
2161 Variables" in the manual for more detail.
2165 GDB now includes an option for defining fast tracepoints, which
2166 targets may implement more efficiently, such as by installing a jump
2167 into the target agent rather than a trap instruction. The resulting
2168 speedup can be by two orders of magnitude or more, although the
2169 tradeoff is that some program locations on some target architectures
2170 might not allow fast tracepoint installation, for instance if the
2171 instruction to be replaced is shorter than the jump. To request a
2172 fast tracepoint, use the "ftrace" command, with syntax identical to
2173 the regular trace command.
2175 ** Disconnected tracing
2177 It is now possible to detach GDB from the target while it is running
2178 a trace experiment, then reconnect later to see how the experiment
2179 is going. In addition, a new variable disconnected-tracing lets you
2180 tell the target agent whether to continue running a trace if the
2181 connection is lost unexpectedly.
2185 GDB now has the ability to save the trace buffer into a file, and
2186 then use that file as a target, similarly to you can do with
2187 corefiles. You can select trace frames, print data that was
2188 collected in them, and use tstatus to display the state of the
2189 tracing run at the moment that it was saved. To create a trace
2190 file, use "tsave <filename>", and to use it, do "target tfile
2193 ** Circular trace buffer
2195 You can ask the target agent to handle the trace buffer as a
2196 circular buffer, discarding the oldest trace frames to make room for
2197 newer ones, by setting circular-trace-buffer to on. This feature may
2198 not be available for all target agents.
2203 The disassemble command, when invoked with two arguments, now requires
2204 the arguments to be comma-separated.
2207 The info variables command now displays variable definitions. Files
2208 which only declare a variable are not shown.
2211 The source command is now capable of sourcing Python scripts.
2212 This feature is dependent on the debugger being build with Python
2215 Related to this enhancement is also the introduction of a new command
2216 "set script-extension" (see below).
2218 * New commands (for set/show, see "New options" below)
2220 record save [<FILENAME>]
2221 Save a file (in core file format) containing the process record
2222 execution log for replay debugging at a later time.
2224 record restore <FILENAME>
2225 Restore the process record execution log that was saved at an
2226 earlier time, for replay debugging.
2228 add-inferior [-copies <N>] [-exec <FILENAME>]
2231 clone-inferior [-copies <N>] [ID]
2232 Make a new inferior ready to execute the same program another
2233 inferior has loaded.
2238 maint info program-spaces
2239 List the program spaces loaded into GDB.
2241 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2242 show remote interrupt-sequence
2243 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2244 as the sequence to the remote target in order to interrupt the execution.
2245 Ctrl-C is a default. Some system prefers BREAK which is high level of
2246 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2247 Magic SysRq g. It is BREAK signal and character 'g'.
2249 set remote interrupt-on-connect [on | off]
2250 show remote interrupt-on-connect
2251 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2252 remote target when gdb connects to it. This is needed when you debug
2255 set remotebreak [on | off]
2257 Deprecated. Use "set/show remote interrupt-sequence" instead.
2259 tvariable $NAME [ = EXP ]
2260 Create or modify a trace state variable.
2263 List trace state variables and their values.
2265 delete tvariable $NAME ...
2266 Delete one or more trace state variables.
2269 Evaluate the given expressions without collecting anything into the
2270 trace buffer. (Valid in tracepoint actions only.)
2272 ftrace FN / FILE:LINE / *ADDR
2273 Define a fast tracepoint at the given function, line, or address.
2275 * New expression syntax
2277 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2278 GDB now parses 0b101010 identically with 42.
2282 set follow-exec-mode new|same
2283 show follow-exec-mode
2284 Control whether GDB reuses the same inferior across an exec call or
2285 creates a new one. This is useful to be able to restart the old
2286 executable after the inferior having done an exec call.
2288 set default-collect EXPR, ...
2289 show default-collect
2290 Define a list of expressions to be collected at each tracepoint.
2291 This is a useful way to ensure essential items are not overlooked,
2292 such as registers or a critical global variable.
2294 set disconnected-tracing
2295 show disconnected-tracing
2296 If set to 1, the target is instructed to continue tracing if it
2297 loses its connection to GDB. If 0, the target is to stop tracing
2300 set circular-trace-buffer
2301 show circular-trace-buffer
2302 If set to on, the target is instructed to use a circular trace buffer
2303 and discard the oldest trace frames instead of stopping the trace due
2304 to a full trace buffer. If set to off, the trace stops when the buffer
2305 fills up. Some targets may not support this.
2307 set script-extension off|soft|strict
2308 show script-extension
2309 If set to "off", the debugger does not perform any script language
2310 recognition, and all sourced files are assumed to be GDB scripts.
2311 If set to "soft" (the default), files are sourced according to
2312 filename extension, falling back to GDB scripts if the first
2314 If set to "strict", files are sourced according to filename extension.
2316 set ada trust-PAD-over-XVS on|off
2317 show ada trust-PAD-over-XVS
2318 If off, activate a workaround against a bug in the debugging information
2319 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2320 the GCC sources for more information about the GNAT encoding and
2321 PAD types in particular). It is always safe to set this option to
2322 off, but this introduces a slight performance penalty. The default
2325 * Python API Improvements
2327 ** GDB provides the new class gdb.LazyString. This is useful in
2328 some pretty-printing cases. The new method gdb.Value.lazy_string
2329 provides a simple way to create objects of this type.
2331 ** The fields returned by gdb.Type.fields now have an
2332 `is_base_class' attribute.
2334 ** The new method gdb.Type.range returns the range of an array type.
2336 ** The new method gdb.parse_and_eval can be used to parse and
2337 evaluate an expression.
2339 * New remote packets
2342 Define a trace state variable.
2345 Get the current value of a trace state variable.
2348 Set desired tracing behavior upon disconnection.
2351 Set the trace buffer to be linear or circular.
2354 Get data about the tracepoints currently in use.
2358 Process record now works correctly with hardware watchpoints.
2360 Multiple bug fixes have been made to the mips-irix port, making it
2361 much more reliable. In particular:
2362 - Debugging threaded applications is now possible again. Previously,
2363 GDB would hang while starting the program, or while waiting for
2364 the program to stop at a breakpoint.
2365 - Attaching to a running process no longer hangs.
2366 - An error occurring while loading a core file has been fixed.
2367 - Changing the value of the PC register now works again. This fixes
2368 problems observed when using the "jump" command, or when calling
2369 a function from GDB, or even when assigning a new value to $pc.
2370 - With the "finish" and "return" commands, the return value for functions
2371 returning a small array is now correctly printed.
2372 - It is now possible to break on shared library code which gets executed
2373 during a shared library init phase (code executed while executing
2374 their .init section). Previously, the breakpoint would have no effect.
2375 - GDB is now able to backtrace through the signal handler for
2376 non-threaded programs.
2378 PIE (Position Independent Executable) programs debugging is now supported.
2379 This includes debugging execution of PIC (Position Independent Code) shared
2380 libraries although for that, it should be possible to run such libraries as an
2383 *** Changes in GDB 7.0
2385 * GDB now has an interface for JIT compilation. Applications that
2386 dynamically generate code can create symbol files in memory and register
2387 them with GDB. For users, the feature should work transparently, and
2388 for JIT developers, the interface is documented in the GDB manual in the
2389 "JIT Compilation Interface" chapter.
2391 * Tracepoints may now be conditional. The syntax is as for
2392 breakpoints; either an "if" clause appended to the "trace" command,
2393 or the "condition" command is available. GDB sends the condition to
2394 the target for evaluation using the same bytecode format as is used
2395 for tracepoint actions.
2397 * The disassemble command now supports: an optional /r modifier, print the
2398 raw instructions in hex as well as in symbolic form, and an optional /m
2399 modifier to print mixed source+assembly.
2401 * Process record and replay
2403 In a architecture environment that supports ``process record and
2404 replay'', ``process record and replay'' target can record a log of
2405 the process execution, and replay it with both forward and reverse
2408 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2409 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2410 set execution-direction {forward|reverse}, for targets that support
2413 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2414 feature is available with a native GDB running on kernel version
2417 * GDB now has support for multi-byte and wide character sets on the
2418 target. Strings whose character type is wchar_t, char16_t, or
2419 char32_t are now correctly printed. GDB supports wide- and unicode-
2420 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2421 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2422 `printf'. This feature requires iconv to work properly; if your
2423 system does not have a working iconv, GDB can use GNU libiconv. See
2424 the installation instructions for more information.
2426 * GDB now supports automatic retrieval of shared library files from
2427 remote targets. To use this feature, specify a system root that begins
2428 with the `remote:' prefix, either via the `set sysroot' command or via
2429 the `--with-sysroot' configure-time option.
2431 * "info sharedlibrary" now takes an optional regex of libraries to show,
2432 and it now reports if a shared library has no debugging information.
2434 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2435 now complete on file names.
2437 * When completing in expressions, gdb will attempt to limit
2438 completions to allowable structure or union fields, where appropriate.
2439 For instance, consider:
2441 # struct example { int f1; double f2; };
2442 # struct example variable;
2445 If the user types TAB at the end of this command line, the available
2446 completions will be "f1" and "f2".
2448 * Inlined functions are now supported. They show up in backtraces, and
2449 the "step", "next", and "finish" commands handle them automatically.
2451 * GDB now supports the token-splicing (##) and stringification (#)
2452 operators when expanding macros. It also supports variable-arity
2455 * GDB now supports inspecting extra signal information, exported by
2456 the new $_siginfo convenience variable. The feature is currently
2457 implemented on linux ARM, i386 and amd64.
2459 * GDB can now display the VFP floating point registers and NEON vector
2460 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2461 can provide these registers (requires Linux 2.6.30 or later). Remote
2462 and simulator targets may also provide them.
2464 * New remote packets
2467 Search memory for a sequence of bytes.
2470 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2471 operation over reliable transport links. Use of this packet is
2472 controlled by the `set remote noack-packet' command.
2475 Kill the process with the specified process ID. Use this in preference
2476 to `k' when multiprocess protocol extensions are supported.
2479 Obtains additional operating system information
2483 Read or write additional signal information.
2485 * Removed remote protocol undocumented extension
2487 An undocumented extension to the remote protocol's `S' stop reply
2488 packet that permited the stub to pass a process id was removed.
2489 Remote servers should use the `T' stop reply packet instead.
2491 * GDB now supports multiple function calling conventions according to the
2492 DWARF-2 DW_AT_calling_convention function attribute.
2494 * The SH target utilizes the aforementioned change to distinguish between gcc
2495 and Renesas calling convention. It also adds the new CLI commands
2496 `set/show sh calling-convention'.
2498 * GDB can now read compressed debug sections, as produced by GNU gold
2499 with the --compress-debug-sections=zlib flag.
2501 * 64-bit core files are now supported on AIX.
2503 * Thread switching is now supported on Tru64.
2505 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2506 which will be allocated using malloc later in program execution.
2508 * The qXfer:libraries:read remote procotol packet now allows passing a
2509 list of section offsets.
2511 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2512 conditions handling signals delivered during attach or thread creation
2513 have also been fixed.
2515 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2516 From the user's standpoint, all unqualified instances of True and False
2517 are treated as the standard definitions, regardless of context.
2519 * GDB now parses C++ symbol and type names more flexibly. For
2522 template<typename T> class C { };
2525 GDB will now correctly handle all of:
2527 ptype C<char const *>
2528 ptype C<char const*>
2529 ptype C<const char *>
2530 ptype C<const char*>
2532 * New features in the GDB remote stub, gdbserver
2534 - The "--wrapper" command-line argument tells gdbserver to use a
2535 wrapper program to launch programs for debugging.
2537 - On PowerPC and S/390 targets, it is now possible to use a single
2538 gdbserver executable to debug both 32-bit and 64-bit programs.
2539 (This requires gdbserver itself to be built as a 64-bit executable.)
2541 - gdbserver uses the new noack protocol mode for TCP connections to
2542 reduce communications latency, if also supported and enabled in GDB.
2544 - Support for the sparc64-linux-gnu target is now included in
2547 - The amd64-linux build of gdbserver now supports debugging both
2548 32-bit and 64-bit programs.
2550 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2551 now support hardware watchpoints, and will use them automatically
2556 GDB now has support for scripting using Python. Whether this is
2557 available is determined at configure time.
2559 New GDB commands can now be written in Python.
2561 * Ada tasking support
2563 Ada tasks can now be inspected in GDB. The following commands have
2567 Print the list of Ada tasks.
2569 Print detailed information about task number N.
2571 Print the task number of the current task.
2573 Switch the context of debugging to task number N.
2575 * Support for user-defined prefixed commands. The "define" command can
2576 add new commands to existing prefixes, e.g. "target".
2578 * Multi-inferior, multi-process debugging.
2580 GDB now has generalized support for multi-inferior debugging. See
2581 "Debugging Multiple Inferiors" in the manual for more information.
2582 Although availability still depends on target support, the command
2583 set is more uniform now. The GNU/Linux specific multi-forks support
2584 has been migrated to this new framework. This implied some user
2585 visible changes; see "New commands" and also "Removed commands"
2588 * Target descriptions can now describe the target OS ABI. See the
2589 "Target Description Format" section in the user manual for more
2592 * Target descriptions can now describe "compatible" architectures
2593 to indicate that the target can execute applications for a different
2594 architecture in addition to those for the main target architecture.
2595 See the "Target Description Format" section in the user manual for
2598 * Multi-architecture debugging.
2600 GDB now includes general supports for debugging applications on
2601 hybrid systems that use more than one single processor architecture
2602 at the same time. Each such hybrid architecture still requires
2603 specific support to be added. The only hybrid architecture supported
2604 in this version of GDB is the Cell Broadband Engine.
2606 * GDB now supports integrated debugging of Cell/B.E. applications that
2607 use both the PPU and SPU architectures. To enable support for hybrid
2608 Cell/B.E. debugging, you need to configure GDB to support both the
2609 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2610 --enable-targets configure option.
2612 * Non-stop mode debugging.
2614 For some targets, GDB now supports an optional mode of operation in
2615 which you can examine stopped threads while other threads continue
2616 to execute freely. This is referred to as non-stop mode, with the
2617 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2618 section in the user manual for more information.
2620 To be able to support remote non-stop debugging, a remote stub needs
2621 to implement the non-stop mode remote protocol extensions, as
2622 described in the "Remote Non-Stop" section of the user manual. The
2623 GDB remote stub, gdbserver, has been adjusted to support these
2624 extensions on linux targets.
2626 * New commands (for set/show, see "New options" below)
2628 catch syscall [NAME(S) | NUMBER(S)]
2629 Catch system calls. Arguments, which should be names of system
2630 calls or their numbers, mean catch only those syscalls. Without
2631 arguments, every syscall will be caught. When the inferior issues
2632 any of the specified syscalls, GDB will stop and announce the system
2633 call, both when it is called and when its call returns. This
2634 feature is currently available with a native GDB running on the
2635 Linux Kernel, under the following architectures: x86, x86_64,
2636 PowerPC and PowerPC64.
2638 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2640 Search memory for a sequence of bytes.
2642 maint set python print-stack
2643 maint show python print-stack
2644 Show a stack trace when an error is encountered in a Python script.
2647 Invoke CODE by passing it to the Python interpreter.
2652 These allow macros to be defined, undefined, and listed
2656 Show operating system information about processes.
2659 List the inferiors currently under GDB's control.
2662 Switch focus to inferior number NUM.
2665 Detach from inferior number NUM.
2668 Kill inferior number NUM.
2672 set spu stop-on-load
2673 show spu stop-on-load
2674 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2676 set spu auto-flush-cache
2677 show spu auto-flush-cache
2678 Control whether to automatically flush the software-managed cache
2679 during Cell/B.E. debugging.
2681 set sh calling-convention
2682 show sh calling-convention
2683 Control the calling convention used when calling SH target functions.
2686 show debug timestamp
2687 Control display of timestamps with GDB debugging output.
2689 set disassemble-next-line
2690 show disassemble-next-line
2691 Control display of disassembled source lines or instructions when
2694 set remote noack-packet
2695 show remote noack-packet
2696 Set/show the use of remote protocol QStartNoAckMode packet. See above
2697 under "New remote packets."
2699 set remote query-attached-packet
2700 show remote query-attached-packet
2701 Control use of remote protocol `qAttached' (query-attached) packet.
2703 set remote read-siginfo-object
2704 show remote read-siginfo-object
2705 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2708 set remote write-siginfo-object
2709 show remote write-siginfo-object
2710 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2713 set remote reverse-continue
2714 show remote reverse-continue
2715 Control use of remote protocol 'bc' (reverse-continue) packet.
2717 set remote reverse-step
2718 show remote reverse-step
2719 Control use of remote protocol 'bs' (reverse-step) packet.
2721 set displaced-stepping
2722 show displaced-stepping
2723 Control displaced stepping mode. Displaced stepping is a way to
2724 single-step over breakpoints without removing them from the debuggee.
2725 Also known as "out-of-line single-stepping".
2728 show debug displaced
2729 Control display of debugging info for displaced stepping.
2731 maint set internal-error
2732 maint show internal-error
2733 Control what GDB does when an internal error is detected.
2735 maint set internal-warning
2736 maint show internal-warning
2737 Control what GDB does when an internal warning is detected.
2742 Use a wrapper program to launch programs for debugging.
2744 set multiple-symbols (all|ask|cancel)
2745 show multiple-symbols
2746 The value of this variable can be changed to adjust the debugger behavior
2747 when an expression or a breakpoint location contains an ambiguous symbol
2748 name (an overloaded function name, for instance).
2750 set breakpoint always-inserted
2751 show breakpoint always-inserted
2752 Keep breakpoints always inserted in the target, as opposed to inserting
2753 them when resuming the target, and removing them when the target stops.
2754 This option can improve debugger performance on slow remote targets.
2756 set arm fallback-mode (arm|thumb|auto)
2757 show arm fallback-mode
2758 set arm force-mode (arm|thumb|auto)
2760 These commands control how ARM GDB determines whether instructions
2761 are ARM or Thumb. The default for both settings is auto, which uses
2762 the current CPSR value for instructions without symbols; previous
2763 versions of GDB behaved as if "set arm fallback-mode arm".
2765 set disable-randomization
2766 show disable-randomization
2767 Standalone programs run with the virtual address space randomization enabled
2768 by default on some platforms. This option keeps the addresses stable across
2769 multiple debugging sessions.
2773 Control whether other threads are stopped or not when some thread hits
2778 Requests that asynchronous execution is enabled in the target, if available.
2779 In this case, it's possible to resume target in the background, and interact
2780 with GDB while the target is running. "show target-async" displays the
2781 current state of asynchronous execution of the target.
2783 set target-wide-charset
2784 show target-wide-charset
2785 The target-wide-charset is the name of the character set that GDB
2786 uses when printing characters whose type is wchar_t.
2788 set tcp auto-retry (on|off)
2790 set tcp connect-timeout
2791 show tcp connect-timeout
2792 These commands allow GDB to retry failed TCP connections to a remote stub
2793 with a specified timeout period; this is useful if the stub is launched
2794 in parallel with GDB but may not be ready to accept connections immediately.
2796 set libthread-db-search-path
2797 show libthread-db-search-path
2798 Control list of directories which GDB will search for appropriate
2801 set schedule-multiple (on|off)
2802 show schedule-multiple
2803 Allow GDB to resume all threads of all processes or only threads of
2804 the current process.
2808 Use more aggressive caching for accesses to the stack. This improves
2809 performance of remote debugging (particularly backtraces) without
2810 affecting correctness.
2812 set interactive-mode (on|off|auto)
2813 show interactive-mode
2814 Control whether GDB runs in interactive mode (on) or not (off).
2815 When in interactive mode, GDB waits for the user to answer all
2816 queries. Otherwise, GDB does not wait and assumes the default
2817 answer. When set to auto (the default), GDB determines which
2818 mode to use based on the stdin settings.
2823 For program forks, this is replaced by the new more generic `info
2824 inferiors' command. To list checkpoints, you can still use the
2825 `info checkpoints' command, which was an alias for the `info forks'
2829 Replaced by the new `inferior' command. To switch between
2830 checkpoints, you can still use the `restart' command, which was an
2831 alias for the `fork' command.
2834 This is removed, since some targets don't have a notion of
2835 processes. To switch between processes, you can still use the
2836 `inferior' command using GDB's own inferior number.
2839 For program forks, this is replaced by the new more generic `kill
2840 inferior' command. To delete a checkpoint, you can still use the
2841 `delete checkpoint' command, which was an alias for the `delete
2845 For program forks, this is replaced by the new more generic `detach
2846 inferior' command. To detach a checkpoint, you can still use the
2847 `detach checkpoint' command, which was an alias for the `detach
2850 * New native configurations
2852 x86/x86_64 Darwin i[34567]86-*-darwin*
2854 x86_64 MinGW x86_64-*-mingw*
2858 Lattice Mico32 lm32-*
2859 x86 DICOS i[34567]86-*-dicos*
2860 x86_64 DICOS x86_64-*-dicos*
2863 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2864 (mingw32ce) debugging.
2870 These commands were actually not implemented on any target.
2872 *** Changes in GDB 6.8
2874 * New native configurations
2876 NetBSD/hppa hppa*-*netbsd*
2877 Xtensa GNU/Linux xtensa*-*-linux*
2881 NetBSD/hppa hppa*-*-netbsd*
2882 Xtensa GNU/Lunux xtensa*-*-linux*
2884 * Change in command line behavior -- corefiles vs. process ids.
2886 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2887 attaching to process NUMBER fails, GDB no longer attempts to open a
2888 core file named NUMBER. Attaching to a program using the -c option
2889 is no longer supported. Instead, use the '-p' or '--pid' options.
2891 * GDB can now be built as a native debugger for debugging Windows x86
2892 (mingw32) Portable Executable (PE) programs.
2894 * Pending breakpoints no longer change their number when their address
2897 * GDB now supports breakpoints with multiple locations,
2898 including breakpoints on C++ constructors, inside C++ templates,
2899 and in inlined functions.
2901 * GDB's ability to debug optimized code has been improved. GDB more
2902 accurately identifies function bodies and lexical blocks that occupy
2903 more than one contiguous range of addresses.
2905 * Target descriptions can now describe registers for PowerPC.
2907 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2908 registers on PowerPC targets.
2910 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2911 targets even when the libthread_db library is not available.
2913 * The GDB remote stub, gdbserver, now supports the new file transfer
2914 commands (remote put, remote get, and remote delete).
2916 * The GDB remote stub, gdbserver, now supports run and attach in
2917 extended-remote mode.
2919 * hppa*64*-*-hpux11* target broken
2920 The debugger is unable to start a program and fails with the following
2921 error: "Error trying to get information about dynamic linker".
2922 The gdb-6.7 release is also affected.
2924 * GDB now supports the --enable-targets= configure option to allow
2925 building a single GDB executable that supports multiple remote
2926 target architectures.
2928 * GDB now supports debugging C and C++ programs which use the
2929 Decimal Floating Point extension. In addition, the PowerPC target
2930 now has a set of pseudo-registers to inspect decimal float values
2931 stored in two consecutive float registers.
2933 * The -break-insert MI command can optionally create pending
2936 * Improved support for debugging Ada
2937 Many improvements to the Ada language support have been made. These
2939 - Better support for Ada2005 interface types
2940 - Improved handling of arrays and slices in general
2941 - Better support for Taft-amendment types
2942 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2944 - Improved command completion in Ada
2947 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2952 set print frame-arguments (all|scalars|none)
2953 show print frame-arguments
2954 The value of this variable can be changed to control which argument
2955 values should be printed by the debugger when displaying a frame.
2960 Transfer files to and from a remote target, and delete remote files.
2967 Transfer files to and from a remote target, and delete remote files.
2969 * New remote packets
2976 Open, close, read, write, and delete files on the remote system.
2979 Attach to an existing process on the remote system, in extended-remote
2983 Run a new process on the remote system, in extended-remote mode.
2985 *** Changes in GDB 6.7
2987 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2988 bfd, libiberty and opcodes, as revealed by static analysis donated by
2989 Coverity, Inc. (http://scan.coverity.com).
2991 * When looking up multiply-defined global symbols, GDB will now prefer the
2992 symbol definition in the current shared library if it was built using the
2993 -Bsymbolic linker option.
2995 * When the Text User Interface (TUI) is not configured, GDB will now
2996 recognize the -tui command-line option and print a message that the TUI
2999 * The GDB remote stub, gdbserver, now has lower overhead for high
3000 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3002 * GDB for MIPS targets now autodetects whether a remote target provides
3003 32-bit or 64-bit register values.
3005 * Support for C++ member pointers has been improved.
3007 * GDB now understands XML target descriptions, which specify the
3008 target's overall architecture. GDB can read a description from
3009 a local file or over the remote serial protocol.
3011 * Vectors of single-byte data use a new integer type which is not
3012 automatically displayed as character or string data.
3014 * The /s format now works with the print command. It displays
3015 arrays of single-byte integers and pointers to single-byte integers
3018 * Target descriptions can now describe target-specific registers,
3019 for architectures which have implemented the support (currently
3020 only ARM, M68K, and MIPS).
3022 * GDB and the GDB remote stub, gdbserver, now support the XScale
3025 * The GDB remote stub, gdbserver, has been updated to support
3026 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3027 has been rewritten to use the standard GDB remote protocol.
3029 * GDB can now step into C++ functions which are called through thunks.
3031 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3033 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3034 layout. It also supports a TextSeg= and DataSeg= response when only
3035 segment base addresses (rather than offsets) are available.
3037 * The /i format now outputs any trailing branch delay slot instructions
3038 immediately following the last instruction within the count specified.
3040 * The GDB remote protocol "T" stop reply packet now supports a
3041 "library" response. Combined with the new "qXfer:libraries:read"
3042 packet, this response allows GDB to debug shared libraries on targets
3043 where the operating system manages the list of loaded libraries (e.g.
3044 Windows and SymbianOS).
3046 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3047 (DLLs) on Windows and Windows CE targets.
3049 * GDB now supports a faster verification that a .debug file matches its binary
3050 according to its build-id signature, if the signature is present.
3056 Enable or disable hardware flow control (RTS/CTS) on the serial port
3057 when debugging using remote targets.
3059 set mem inaccessible-by-default
3060 show mem inaccessible-by-default
3061 If the target supplies a memory map, for instance via the remote
3062 protocol's "qXfer:memory-map:read" packet, setting this variable
3063 prevents GDB from accessing memory outside the memory map. This
3064 is useful for targets with memory mapped registers or which react
3065 badly to accesses of unmapped address space.
3067 set breakpoint auto-hw
3068 show breakpoint auto-hw
3069 If the target supplies a memory map, for instance via the remote
3070 protocol's "qXfer:memory-map:read" packet, setting this variable
3071 lets GDB use hardware breakpoints automatically for memory regions
3072 where it can not use software breakpoints. This covers both the
3073 "break" command and internal breakpoints used for other commands
3074 including "next" and "finish".
3077 catch exception unhandled
3078 Stop the program execution when Ada exceptions are raised.
3081 Stop the program execution when an Ada assertion failed.
3085 Set an alternate system root for target files. This is a more
3086 general version of "set solib-absolute-prefix", which is now
3087 an alias to "set sysroot".
3090 Provide extended SPU facility status information. This set of
3091 commands is available only when debugging the Cell/B.E. SPU
3094 * New native configurations
3096 OpenBSD/sh sh*-*openbsd*
3099 unset tdesc filename
3101 Use the specified local file as an XML target description, and do
3102 not query the target for its built-in description.
3106 OpenBSD/sh sh*-*-openbsd*
3107 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3108 Toshiba Media Processor mep-elf
3110 * New remote packets
3113 Ignore the specified signals; pass them directly to the debugged program
3114 without stopping other threads or reporting them to GDB.
3116 qXfer:features:read:
3117 Read an XML target description from the target, which describes its
3122 Read or write contents of an spufs file on the target system. These
3123 packets are available only on the Cell/B.E. SPU architecture.
3125 qXfer:libraries:read:
3126 Report the loaded shared libraries. Combined with new "T" packet
3127 response, this packet allows GDB to debug shared libraries on
3128 targets where the operating system manages the list of loaded
3129 libraries (e.g. Windows and SymbianOS).
3133 Support for these obsolete configurations has been removed.
3141 i[34567]86-*-lynxos*
3142 i[34567]86-*-netware*
3143 i[34567]86-*-sco3.2v5*
3144 i[34567]86-*-sco3.2v4*
3146 i[34567]86-*-sysv4.2*
3149 i[34567]86-*-unixware2*
3150 i[34567]86-*-unixware*
3159 * Other removed features
3166 Various m68k-only ROM monitors.
3173 Various Renesas ROM monitors and debugging interfaces for SH and
3178 Support for a Macraigor serial interface to on-chip debugging.
3179 GDB does not directly support the newer parallel or USB
3184 A debug information format. The predecessor to DWARF 2 and
3185 DWARF 3, which are still supported.
3187 Support for the HP aCC compiler on HP-UX/PA-RISC
3189 SOM-encapsulated symbolic debugging information, automatic
3190 invocation of pxdb, and the aCC custom C++ ABI. This does not
3191 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3192 with aCC can still be debugged on an assembly level.
3194 MIPS ".pdr" sections
3196 A MIPS-specific format used to describe stack frame layout
3197 in debugging information.
3201 GDB could work with an older version of Guile to debug
3202 the interpreter and Scheme programs running in it.
3204 set mips stack-arg-size
3205 set mips saved-gpreg-size
3207 Use "set mips abi" to control parameter passing for MIPS.
3209 *** Changes in GDB 6.6
3214 Cell Broadband Engine SPU spu-elf
3216 * GDB can now be configured as a cross-debugger targeting native Windows
3217 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3218 running on a Windows system over TCP/IP to debug Windows programs.
3220 * The GDB remote stub, gdbserver, has been updated to support Windows and
3221 Cygwin debugging. Both single-threaded and multi-threaded programs are
3224 * The "set trust-readonly-sections" command works again. This command was
3225 broken in GDB 6.3, 6.4, and 6.5.
3227 * The "load" command now supports writing to flash memory, if the remote
3228 stub provides the required support.
3230 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3231 longer requires symbolic debug information (e.g. DWARF-2).
3236 unset substitute-path
3237 show substitute-path
3238 Manage a list of substitution rules that GDB uses to rewrite the name
3239 of the directories where the sources are located. This can be useful
3240 for instance when the sources were moved to a different location
3241 between compilation and debugging.
3245 Print each CLI command as it is executed. Each command is prefixed with
3246 a number of `+' symbols representing the nesting depth.
3247 The source command now has a `-v' option to enable the same feature.
3251 The ARM Demon monitor support (RDP protocol, "target rdp").
3253 Kernel Object Display, an embedded debugging feature which only worked with
3254 an obsolete version of Cisco IOS.
3256 The 'set download-write-size' and 'show download-write-size' commands.
3258 * New remote packets
3261 Tell a stub about GDB client features, and request remote target features.
3262 The first feature implemented is PacketSize, which allows the target to
3263 specify the size of packets it can handle - to minimize the number of
3264 packets required and improve performance when connected to a remote
3268 Fetch an OS auxilliary vector from the remote stub. This packet is a
3269 more efficient replacement for qPart:auxv:read.
3271 qXfer:memory-map:read:
3272 Fetch a memory map from the remote stub, including information about
3273 RAM, ROM, and flash memory devices.
3278 Erase and program a flash memory device.
3280 * Removed remote packets
3283 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3284 used it, and only gdbserver implemented it.
3286 *** Changes in GDB 6.5
3290 Renesas M32C/M16C m32c-elf
3292 Morpho Technologies ms1 ms1-elf
3296 init-if-undefined Initialize a convenience variable, but
3297 only if it doesn't already have a value.
3299 The following commands are presently only implemented for native GNU/Linux:
3301 checkpoint Save a snapshot of the program state.
3303 restart <n> Return the program state to a
3304 previously saved state.
3306 info checkpoints List currently saved checkpoints.
3308 delete-checkpoint <n> Delete a previously saved checkpoint.
3310 set|show detach-on-fork Tell gdb whether to detach from a newly
3311 forked process, or to keep debugging it.
3313 info forks List forks of the user program that
3314 are available to be debugged.
3316 fork <n> Switch to debugging one of several
3317 forks of the user program that are
3318 available to be debugged.
3320 delete-fork <n> Delete a fork from the list of forks
3321 that are available to be debugged (and
3322 kill the forked process).
3324 detach-fork <n> Delete a fork from the list of forks
3325 that are available to be debugged (and
3326 allow the process to continue).
3330 Morpho Technologies ms2 ms1-elf
3332 * Improved Windows host support
3334 GDB now builds as a cross debugger hosted on i686-mingw32, including
3335 native console support, and remote communications using either
3336 network sockets or serial ports.
3338 * Improved Modula-2 language support
3340 GDB can now print most types in the Modula-2 syntax. This includes:
3341 basic types, set types, record types, enumerated types, range types,
3342 pointer types and ARRAY types. Procedure var parameters are correctly
3343 printed and hexadecimal addresses and character constants are also
3344 written in the Modula-2 syntax. Best results can be obtained by using
3345 GNU Modula-2 together with the -gdwarf-2 command line option.
3349 The ARM rdi-share module.
3351 The Netware NLM debug server.
3353 *** Changes in GDB 6.4
3355 * New native configurations
3357 OpenBSD/arm arm*-*-openbsd*
3358 OpenBSD/mips64 mips64-*-openbsd*
3362 Morpho Technologies ms1 ms1-elf
3364 * New command line options
3366 --batch-silent As for --batch, but totally silent.
3367 --return-child-result The debugger will exist with the same value
3368 the child (debugged) program exited with.
3369 --eval-command COMMAND, -ex COMMAND
3370 Execute a single GDB CLI command. This may be
3371 specified multiple times and in conjunction
3372 with the --command (-x) option.
3374 * Deprecated commands removed
3376 The following commands, that were deprecated in 2000, have been
3380 set|show arm disassembly-flavor set|show arm disassembler
3381 othernames set arm disassembler
3382 set|show remotedebug set|show debug remote
3383 set|show archdebug set|show debug arch
3384 set|show eventdebug set|show debug event
3387 * New BSD user-level threads support
3389 It is now possible to debug programs using the user-level threads
3390 library on OpenBSD and FreeBSD. Currently supported (target)
3393 FreeBSD/amd64 x86_64-*-freebsd*
3394 FreeBSD/i386 i386-*-freebsd*
3395 OpenBSD/i386 i386-*-openbsd*
3397 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3398 are not yet supported.
3400 * New support for Matsushita MN10300 w/sim added
3401 (Work in progress). mn10300-elf.
3403 * REMOVED configurations and files
3405 VxWorks and the XDR protocol *-*-vxworks
3406 Motorola MCORE mcore-*-*
3407 National Semiconductor NS32000 ns32k-*-*
3409 * New "set print array-indexes" command
3411 After turning this setting "on", GDB prints the index of each element
3412 when displaying arrays. The default is "off" to preserve the previous
3415 * VAX floating point support
3417 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3419 * User-defined command support
3421 In addition to using $arg0..$arg9 for argument passing, it is now possible
3422 to use $argc to determine now many arguments have been passed. See the
3423 section on user-defined commands in the user manual for more information.
3425 *** Changes in GDB 6.3:
3427 * New command line option
3429 GDB now accepts -l followed by a number to set the timeout for remote
3432 * GDB works with GCC -feliminate-dwarf2-dups
3434 GDB now supports a more compact representation of DWARF-2 debug
3435 information using DW_FORM_ref_addr references. These are produced
3436 by GCC with the option -feliminate-dwarf2-dups and also by some
3437 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3438 to use -feliminate-dwarf2-dups.
3440 * Internationalization
3442 When supported by the host system, GDB will be built with
3443 internationalization (libintl). The task of marking up the sources is
3444 continued, we're looking forward to our first translation.
3448 Initial support for debugging programs compiled with the GNAT
3449 implementation of the Ada programming language has been integrated
3450 into GDB. In this release, support is limited to expression evaluation.
3452 * New native configurations
3454 GNU/Linux/m32r m32r-*-linux-gnu
3458 GDB's remote protocol now includes support for the 'p' packet. This
3459 packet is used to fetch individual registers from a remote inferior.
3461 * END-OF-LIFE registers[] compatibility module
3463 GDB's internal register infrastructure has been completely rewritten.
3464 The new infrastructure making possible the implementation of key new
3465 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3468 GDB 6.3 will be the last release to include the the registers[]
3469 compatibility module that allowed out-of-date configurations to
3470 continue to work. This change directly impacts the following
3480 powerpc bdm protocol
3482 Unless there is activity to revive these configurations, they will be
3483 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3485 * OBSOLETE configurations and files
3487 Configurations that have been declared obsolete in this release have
3488 been commented out. Unless there is activity to revive these
3489 configurations, the next release of GDB will have their sources
3490 permanently REMOVED.
3499 *** Changes in GDB 6.2.1:
3501 * MIPS `break main; run' gave an heuristic-fence-post warning
3503 When attempting to run even a simple program, a warning about
3504 heuristic-fence-post being hit would be reported. This problem has
3507 * MIPS IRIX 'long double' crashed GDB
3509 When examining a long double variable, GDB would get a segmentation
3510 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3511 IRIX long double values).
3515 A bug in the VAX stack code was causing problems with the "next"
3516 command. This problem has been fixed.
3518 *** Changes in GDB 6.2:
3520 * Fix for ``many threads''
3522 On GNU/Linux systems that use the NPTL threads library, a program
3523 rapidly creating and deleting threads would confuse GDB leading to the
3526 ptrace: No such process.
3527 thread_db_get_info: cannot get thread info: generic error
3529 This problem has been fixed.
3531 * "-async" and "-noasync" options removed.
3533 Support for the broken "-noasync" option has been removed (it caused
3536 * New ``start'' command.
3538 This command runs the program until the begining of the main procedure.
3540 * New BSD Kernel Data Access Library (libkvm) interface
3542 Using ``target kvm'' it is now possible to debug kernel core dumps and
3543 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3544 platforms. Currently supported (native-only) configurations are:
3546 FreeBSD/amd64 x86_64-*-freebsd*
3547 FreeBSD/i386 i?86-*-freebsd*
3548 NetBSD/i386 i?86-*-netbsd*
3549 NetBSD/m68k m68*-*-netbsd*
3550 NetBSD/sparc sparc-*-netbsd*
3551 OpenBSD/amd64 x86_64-*-openbsd*
3552 OpenBSD/i386 i?86-*-openbsd*
3553 OpenBSD/m68k m68*-openbsd*
3554 OpenBSD/sparc sparc-*-openbsd*
3556 * Signal trampoline code overhauled
3558 Many generic problems with GDB's signal handling code have been fixed.
3559 These include: backtraces through non-contiguous stacks; recognition
3560 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3561 call; backtrace through a signal trampoline; step into and out of
3562 signal handlers; and single-stepping in the signal trampoline.
3564 Please note that kernel bugs are a limiting factor here. These
3565 features have been shown to work on an s390 GNU/Linux system that
3566 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3568 * Cygwin support for DWARF 2 added.
3570 * New native configurations
3572 GNU/Linux/hppa hppa*-*-linux*
3573 OpenBSD/hppa hppa*-*-openbsd*
3574 OpenBSD/m68k m68*-*-openbsd*
3575 OpenBSD/m88k m88*-*-openbsd*
3576 OpenBSD/powerpc powerpc-*-openbsd*
3577 NetBSD/vax vax-*-netbsd*
3578 OpenBSD/vax vax-*-openbsd*
3580 * END-OF-LIFE frame compatibility module
3582 GDB's internal frame infrastructure has been completely rewritten.
3583 The new infrastructure making it possible to support key new features
3584 including DWARF 2 Call Frame Information. To aid in the task of
3585 migrating old configurations to this new infrastructure, a
3586 compatibility module, that allowed old configurations to continue to
3587 work, was also included.
3589 GDB 6.2 will be the last release to include this frame compatibility
3590 module. This change directly impacts the following configurations:
3600 Unless there is activity to revive these configurations, they will be
3601 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3603 * REMOVED configurations and files
3605 Sun 3, running SunOS 3 m68*-*-sunos3*
3606 Sun 3, running SunOS 4 m68*-*-sunos4*
3607 Sun 2, running SunOS 3 m68000-*-sunos3*
3608 Sun 2, running SunOS 4 m68000-*-sunos4*
3609 Motorola 680x0 running LynxOS m68*-*-lynxos*
3610 AT&T 3b1/Unix pc m68*-att-*
3611 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3612 decstation mips-dec-* mips-little-*
3613 riscos mips-*-riscos* mips-*-sysv*
3614 sonymips mips-sony-*
3615 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3617 *** Changes in GDB 6.1.1:
3619 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3621 The TUI (Text-mode User Interface) is now built as part of a default
3622 GDB configuration. It is enabled by either selecting the TUI with the
3623 command line option "-i=tui" or by running the separate "gdbtui"
3624 program. For more information on the TUI, see the manual "Debugging
3627 * Pending breakpoint support (also included in GDB 6.1)
3629 Support has been added to allow you to specify breakpoints in shared
3630 libraries that have not yet been loaded. If a breakpoint location
3631 cannot be found, and the "breakpoint pending" option is set to auto,
3632 GDB queries you if you wish to make the breakpoint pending on a future
3633 shared-library load. If and when GDB resolves the breakpoint symbol,
3634 the pending breakpoint is removed as one or more regular breakpoints
3637 Pending breakpoints are very useful for GCJ Java debugging.
3639 * Fixed ISO-C build problems
3641 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3642 non ISO-C code that stopped them being built using a more strict ISO-C
3643 compiler (e.g., IBM's C compiler).
3645 * Fixed build problem on IRIX 5
3647 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3648 wasn't able to compile compile on an IRIX 5 system.
3650 * Added execute permission to gdb/gdbserver/configure
3652 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3653 permission. This bug would cause configure to fail on a number of
3654 systems (Solaris, IRIX). Ref: server/519.
3656 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3658 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3659 has been updated to use constant array sizes.
3661 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3663 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3664 its generated DWARF Call Frame Info. This encoding was causing GDB to
3665 panic, that panic has been fixed. Ref: gdb/1628.
3667 * Fixed a problem when examining parameters in shared library code.
3669 When examining parameters in optimized shared library code generated
3670 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3671 not available''. GDB now correctly displays the variable's value.
3673 *** Changes in GDB 6.1:
3675 * Removed --with-mmalloc
3677 Support for the mmalloc memory manager has been removed, as it
3678 conflicted with the internal gdb byte cache.
3680 * Changes in AMD64 configurations
3682 The AMD64 target now includes the %cs and %ss registers. As a result
3683 the AMD64 remote protocol has changed; this affects the floating-point
3684 and SSE registers. If you rely on those registers for your debugging,
3685 you should upgrade gdbserver on the remote side.
3687 * Revised SPARC target
3689 The SPARC target has been completely revised, incorporating the
3690 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3691 support for LynxOS and SunOS 4 has been dropped. Calling functions
3692 from within GDB on operating systems with a non-executable stack
3693 (Solaris, OpenBSD) now works.
3697 GDB has a new C++ demangler which does a better job on the mangled
3698 names generated by current versions of g++. It also runs faster, so
3699 with this and other changes gdb should now start faster on large C++
3702 * DWARF 2 Location Expressions
3704 GDB support for location expressions has been extended to support function
3705 arguments and frame bases. Older versions of GDB could crash when they
3708 * C++ nested types and namespaces
3710 GDB's support for nested types and namespaces in C++ has been
3711 improved, especially if you use the DWARF 2 debugging format. (This
3712 is the default for recent versions of GCC on most platforms.)
3713 Specifically, if you have a class "Inner" defined within a class or
3714 namespace "Outer", then GDB realizes that the class's name is
3715 "Outer::Inner", not simply "Inner". This should greatly reduce the
3716 frequency of complaints about not finding RTTI symbols. In addition,
3717 if you are stopped at inside of a function defined within a namespace,
3718 GDB modifies its name lookup accordingly.
3720 * New native configurations
3722 NetBSD/amd64 x86_64-*-netbsd*
3723 OpenBSD/amd64 x86_64-*-openbsd*
3724 OpenBSD/alpha alpha*-*-openbsd*
3725 OpenBSD/sparc sparc-*-openbsd*
3726 OpenBSD/sparc64 sparc64-*-openbsd*
3728 * New debugging protocols
3730 M32R with SDI protocol m32r-*-elf*
3732 * "set prompt-escape-char" command deleted.
3734 The command "set prompt-escape-char" has been deleted. This command,
3735 and its very obscure effet on GDB's prompt, was never documented,
3736 tested, nor mentioned in the NEWS file.
3738 * OBSOLETE configurations and files
3740 Configurations that have been declared obsolete in this release have
3741 been commented out. Unless there is activity to revive these
3742 configurations, the next release of GDB will have their sources
3743 permanently REMOVED.
3745 Sun 3, running SunOS 3 m68*-*-sunos3*
3746 Sun 3, running SunOS 4 m68*-*-sunos4*
3747 Sun 2, running SunOS 3 m68000-*-sunos3*
3748 Sun 2, running SunOS 4 m68000-*-sunos4*
3749 Motorola 680x0 running LynxOS m68*-*-lynxos*
3750 AT&T 3b1/Unix pc m68*-att-*
3751 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3752 decstation mips-dec-* mips-little-*
3753 riscos mips-*-riscos* mips-*-sysv*
3754 sonymips mips-sony-*
3755 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3757 * REMOVED configurations and files
3759 SGI Irix-4.x mips-sgi-irix4 or iris4
3760 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3761 Z8000 simulator z8k-zilog-none or z8ksim
3762 Matsushita MN10200 w/simulator mn10200-*-*
3763 H8/500 simulator h8500-hitachi-hms or h8500hms
3764 HP/PA running BSD hppa*-*-bsd*
3765 HP/PA running OSF/1 hppa*-*-osf*
3766 HP/PA Pro target hppa*-*-pro*
3767 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3768 386BSD i[3456]86-*-bsd*
3769 Sequent family i[3456]86-sequent-sysv4*
3770 i[3456]86-sequent-sysv*
3771 i[3456]86-sequent-bsd*
3772 SPARC running LynxOS sparc-*-lynxos*
3773 SPARC running SunOS 4 sparc-*-sunos4*
3774 Tsqware Sparclet sparclet-*-*
3775 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3777 *** Changes in GDB 6.0:
3781 Support for debugging the Objective-C programming language has been
3782 integrated into GDB.
3784 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3786 DWARF 2's Call Frame Information makes available compiler generated
3787 information that more exactly describes the program's run-time stack.
3788 By using this information, GDB is able to provide more robust stack
3791 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3792 have been updated to use a new backtrace mechanism which includes
3793 DWARF 2 CFI support.
3797 GDB's remote protocol has been extended to include support for hosted
3798 file I/O (where the remote target uses GDB's file system). See GDB's
3799 remote protocol documentation for details.
3801 * All targets using the new architecture framework.
3803 All of GDB's targets have been updated to use the new internal
3804 architecture framework. The way is now open for future GDB releases
3805 to include cross-architecture native debugging support (i386 on amd64,
3808 * GNU/Linux's Thread Local Storage (TLS)
3810 GDB now includes support for for the GNU/Linux implementation of
3811 per-thread variables.
3813 * GNU/Linux's Native POSIX Thread Library (NPTL)
3815 GDB's thread code has been updated to work with either the new
3816 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3818 * Separate debug info.
3820 GDB, in conjunction with BINUTILS, now supports a mechanism for
3821 automatically loading debug information from a separate file. Instead
3822 of shipping full debug and non-debug versions of system libraries,
3823 system integrators can now instead ship just the stripped libraries
3824 and optional debug files.
3826 * DWARF 2 Location Expressions
3828 DWARF 2 Location Expressions allow the compiler to more completely
3829 describe the location of variables (even in optimized code) to the
3832 GDB now includes preliminary support for location expressions (support
3833 for DW_OP_piece is still missing).
3837 A number of long standing bugs that caused GDB to die while starting a
3838 Java application have been fixed. GDB's Java support is now
3839 considered "useable".
3841 * GNU/Linux support for fork, vfork, and exec.
3843 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3844 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3847 * GDB supports logging output to a file
3849 There are two new commands, "set logging" and "show logging", which can be
3850 used to capture GDB's output to a file.
3852 * The meaning of "detach" has changed for gdbserver
3854 The "detach" command will now resume the application, as documented. To
3855 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3858 * d10v, m68hc11 `regs' command deprecated
3860 The `info registers' command has been updated so that it displays the
3861 registers using a format identical to the old `regs' command.
3865 A new command, "maint set profile on/off", has been added. This command can
3866 be used to enable or disable profiling while running GDB, to profile a
3867 session or a set of commands. In addition there is a new configure switch,
3868 "--enable-profiling", which will cause GDB to be compiled with profiling
3869 data, for more informative profiling results.
3871 * Default MI syntax changed to "mi2".
3873 The default MI (machine interface) syntax, enabled by the command line
3874 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3875 "mi1", can be enabled by specifying the option "-i=mi1".
3877 Support for the original "mi0" syntax (included in GDB 5.0) has been
3880 Fix for gdb/192: removed extraneous space when displaying frame level.
3881 Fix for gdb/672: update changelist is now output in mi list format.
3882 Fix for gdb/702: a -var-assign that updates the value now shows up
3883 in a subsequent -var-update.
3885 * New native configurations.
3887 FreeBSD/amd64 x86_64-*-freebsd*
3889 * Multi-arched targets.
3891 HP/PA HPUX11 hppa*-*-hpux*
3892 Renesas M32R/D w/simulator m32r-*-elf*
3894 * OBSOLETE configurations and files
3896 Configurations that have been declared obsolete in this release have
3897 been commented out. Unless there is activity to revive these
3898 configurations, the next release of GDB will have their sources
3899 permanently REMOVED.
3901 Z8000 simulator z8k-zilog-none or z8ksim
3902 Matsushita MN10200 w/simulator mn10200-*-*
3903 H8/500 simulator h8500-hitachi-hms or h8500hms
3904 HP/PA running BSD hppa*-*-bsd*
3905 HP/PA running OSF/1 hppa*-*-osf*
3906 HP/PA Pro target hppa*-*-pro*
3907 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3908 Sequent family i[3456]86-sequent-sysv4*
3909 i[3456]86-sequent-sysv*
3910 i[3456]86-sequent-bsd*
3911 Tsqware Sparclet sparclet-*-*
3912 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3914 * REMOVED configurations and files
3917 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3918 IBM AIX PS/2 i[3456]86-*-aix
3919 i386 running Mach 3.0 i[3456]86-*-mach3*
3920 i386 running Mach i[3456]86-*-mach*
3921 i386 running OSF/1 i[3456]86-*osf1mk*
3922 HP/Apollo 68k Family m68*-apollo*-sysv*,
3924 m68*-hp-bsd*, m68*-hp-hpux*
3925 Argonaut Risc Chip (ARC) arc-*-*
3926 Mitsubishi D30V d30v-*-*
3927 Fujitsu FR30 fr30-*-elf*
3928 OS/9000 i[34]86-*-os9k
3929 I960 with MON960 i960-*-coff
3931 * MIPS $fp behavior changed
3933 The convenience variable $fp, for the MIPS, now consistently returns
3934 the address of the current frame's base. Previously, depending on the
3935 context, $fp could refer to either $sp or the current frame's base
3936 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3937 The GNU Source-Level Debugger''.
3939 *** Changes in GDB 5.3:
3941 * GNU/Linux shared library multi-threaded performance improved.
3943 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3944 `/proc', in preference to `ptrace' for memory reads. This may result
3945 in an improvement in the start-up time of multi-threaded, shared
3946 library applications when run under GDB. One GDB user writes: ``loads
3947 shared libs like mad''.
3949 * ``gdbserver'' now supports multi-threaded applications on some targets
3951 Support for debugging multi-threaded applications which use
3952 the GNU/Linux LinuxThreads package has been added for
3953 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3954 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3956 * GDB now supports C/C++ preprocessor macros.
3958 GDB now expands preprocessor macro invocations in C/C++ expressions,
3959 and provides various commands for showing macro definitions and how
3962 The new command `macro expand EXPRESSION' expands any macro
3963 invocations in expression, and shows the result.
3965 The new command `show macro MACRO-NAME' shows the definition of the
3966 macro named MACRO-NAME, and where it was defined.
3968 Most compilers don't include information about macros in the debugging
3969 information by default. In GCC 3.1, for example, you need to compile
3970 your program with the options `-gdwarf-2 -g3'. If the macro
3971 information is present in the executable, GDB will read it.
3973 * Multi-arched targets.
3975 DEC Alpha (partial) alpha*-*-*
3976 DEC VAX (partial) vax-*-*
3978 National Semiconductor NS32000 (partial) ns32k-*-*
3979 Motorola 68000 (partial) m68k-*-*
3980 Motorola MCORE mcore-*-*
3984 Fujitsu FRV architecture added by Red Hat frv*-*-*
3987 * New native configurations
3989 Alpha NetBSD alpha*-*-netbsd*
3990 SH NetBSD sh*-*-netbsdelf*
3991 MIPS NetBSD mips*-*-netbsd*
3992 UltraSPARC NetBSD sparc64-*-netbsd*
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 Mitsubishi D30V d30v-*-*
4002 OS/9000 i[34]86-*-os9k
4003 IBM AIX PS/2 i[3456]86-*-aix
4004 Fujitsu FR30 fr30-*-elf*
4005 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4006 Argonaut Risc Chip (ARC) arc-*-*
4007 i386 running Mach 3.0 i[3456]86-*-mach3*
4008 i386 running Mach i[3456]86-*-mach*
4009 i386 running OSF/1 i[3456]86-*osf1mk*
4010 HP/Apollo 68k Family m68*-apollo*-sysv*,
4012 m68*-hp-bsd*, m68*-hp-hpux*
4013 I960 with MON960 i960-*-coff
4015 * OBSOLETE languages
4017 CHILL, a Pascal like language used by telecommunications companies.
4019 * REMOVED configurations and files
4021 AMD 29k family via UDI a29k-amd-udi, udi29k
4022 A29K VxWorks a29k-*-vxworks
4023 AMD 29000 embedded, using EBMON a29k-none-none
4024 AMD 29000 embedded with COFF a29k-none-coff
4025 AMD 29000 embedded with a.out a29k-none-aout
4027 testsuite/gdb.hp/gdb.threads-hp/ directory
4029 * New command "set max-user-call-depth <nnn>"
4031 This command allows the user to limit the call depth of user-defined
4032 commands. The default is 1024.
4034 * Changes in FreeBSD/i386 native debugging.
4036 Support for the "generate-core-file" has been added.
4038 * New commands "dump", "append", and "restore".
4040 These commands allow data to be copied from target memory
4041 to a bfd-format or binary file (dump and append), and back
4042 from a file into memory (restore).
4044 * Improved "next/step" support on multi-processor Alpha Tru64.
4046 The previous single-step mechanism could cause unpredictable problems,
4047 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4048 of a software single-step mechanism prevents this.
4050 *** Changes in GDB 5.2.1:
4058 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4059 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4060 Fix, by Joel Brobecker imported from mainline.
4062 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4063 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4064 Fix, by Fred Fish, imported from mainline.
4066 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4067 Surprisingly enough, it works now.
4068 By Michal Ludvig, imported from mainline.
4070 i386 hardware watchpoint support:
4071 avoid misses on second run for some targets.
4072 By Pierre Muller, imported from mainline.
4074 *** Changes in GDB 5.2:
4076 * New command "set trust-readonly-sections on[off]".
4078 This command is a hint that tells gdb that read-only sections
4079 really are read-only (ie. that their contents will not change).
4080 In this mode, gdb will go to the object file rather than the
4081 target to read memory from read-only sections (such as ".text").
4082 This can be a significant performance improvement on some
4083 (notably embedded) targets.
4085 * New command "generate-core-file" (or "gcore").
4087 This new gdb command allows the user to drop a core file of the child
4088 process state at any time. So far it's been implemented only for
4089 GNU/Linux and Solaris, but should be relatively easily ported to other
4090 hosts. Argument is core file name (defaults to core.<pid>).
4092 * New command line option
4094 GDB now accepts --pid or -p followed by a process id.
4096 * Change in command line behavior -- corefiles vs. process ids.
4098 There is a subtle behavior in the way in which GDB handles
4099 command line arguments. The first non-flag argument is always
4100 a program to debug, but the second non-flag argument may either
4101 be a corefile or a process id. Previously, GDB would attempt to
4102 open the second argument as a corefile, and if that failed, would
4103 issue a superfluous error message and then attempt to attach it as
4104 a process. Now, if the second argument begins with a non-digit,
4105 it will be treated as a corefile. If it begins with a digit,
4106 GDB will attempt to attach it as a process, and if no such process
4107 is found, will then attempt to open it as a corefile.
4109 * Changes in ARM configurations.
4111 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4112 configuration is fully multi-arch.
4114 * New native configurations
4116 ARM NetBSD arm*-*-netbsd*
4117 x86 OpenBSD i[3456]86-*-openbsd*
4118 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4119 Sparc64 running FreeBSD sparc64-*-freebsd*
4123 Sanyo XStormy16 xstormy16-elf
4125 * OBSOLETE configurations and files
4127 Configurations that have been declared obsolete in this release have
4128 been commented out. Unless there is activity to revive these
4129 configurations, the next release of GDB will have their sources
4130 permanently REMOVED.
4132 AMD 29k family via UDI a29k-amd-udi, udi29k
4133 A29K VxWorks a29k-*-vxworks
4134 AMD 29000 embedded, using EBMON a29k-none-none
4135 AMD 29000 embedded with COFF a29k-none-coff
4136 AMD 29000 embedded with a.out a29k-none-aout
4138 testsuite/gdb.hp/gdb.threads-hp/ directory
4140 * REMOVED configurations and files
4142 TI TMS320C80 tic80-*-*
4144 PowerPC Solaris powerpcle-*-solaris*
4145 PowerPC Windows NT powerpcle-*-cygwin32
4146 PowerPC Netware powerpc-*-netware*
4147 Harris/CXUX m88k m88*-harris-cxux*
4148 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4149 ns32k-utek-sysv* ns32k-utek-*
4150 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4151 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4152 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4153 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4154 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4156 * Changes to command line processing
4158 The new `--args' feature can be used to specify command-line arguments
4159 for the inferior from gdb's command line.
4161 * Changes to key bindings
4163 There is a new `operate-and-get-next' function bound to `C-o'.
4165 *** Changes in GDB 5.1.1
4167 Fix compile problem on DJGPP.
4169 Fix a problem with floating-point registers on the i386 being
4172 Fix to stop GDB crashing on .debug_str debug info.
4174 Numerous documentation fixes.
4176 Numerous testsuite fixes.
4178 *** Changes in GDB 5.1:
4180 * New native configurations
4182 Alpha FreeBSD alpha*-*-freebsd*
4183 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4184 MIPS GNU/Linux mips*-*-linux*
4185 MIPS SGI Irix 6.x mips*-sgi-irix6*
4186 ia64 AIX ia64-*-aix*
4187 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4191 Motorola 68HC11 and 68HC12 m68hc11-elf
4193 UltraSparc running GNU/Linux sparc64-*-linux*
4195 * OBSOLETE configurations and files
4197 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4198 Harris/CXUX m88k m88*-harris-cxux*
4199 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4200 ns32k-utek-sysv* ns32k-utek-*
4201 TI TMS320C80 tic80-*-*
4203 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4204 PowerPC Solaris powerpcle-*-solaris*
4205 PowerPC Windows NT powerpcle-*-cygwin32
4206 PowerPC Netware powerpc-*-netware*
4207 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4208 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4209 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4210 Apple Macintosh (MPW) host N/A
4212 stuff.c (Program to stuff files into a specially prepared space in kdb)
4213 kdb-start.c (Main loop for the standalone kernel debugger)
4215 Configurations that have been declared obsolete in this release have
4216 been commented out. Unless there is activity to revive these
4217 configurations, the next release of GDB will have their sources
4218 permanently REMOVED.
4220 * REMOVED configurations and files
4222 Altos 3068 m68*-altos-*
4223 Convex c1-*-*, c2-*-*
4225 ARM RISCix arm-*-* (as host)
4229 * GDB has been converted to ISO C.
4231 GDB's source code has been converted to ISO C. In particular, the
4232 sources are fully protoized, and rely on standard headers being
4237 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4239 * The MI enabled by default.
4241 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4242 revised and enabled by default. Packages which use GDB as a debugging
4243 engine behind a UI or another front end are encouraged to switch to
4244 using the GDB/MI interface, instead of the old annotations interface
4245 which is now deprecated.
4247 * Support for debugging Pascal programs.
4249 GDB now includes support for debugging Pascal programs. The following
4250 main features are supported:
4252 - Pascal-specific data types such as sets;
4254 - automatic recognition of Pascal sources based on file-name
4257 - Pascal-style display of data types, variables, and functions;
4259 - a Pascal expression parser.
4261 However, some important features are not yet supported.
4263 - Pascal string operations are not supported at all;
4265 - there are some problems with boolean types;
4267 - Pascal type hexadecimal constants are not supported
4268 because they conflict with the internal variables format;
4270 - support for Pascal objects and classes is not full yet;
4272 - unlike Pascal, GDB is case-sensitive for symbol names.
4274 * Changes in completion.
4276 Commands such as `shell', `run' and `set args', which pass arguments
4277 to inferior programs, now complete on file names, similar to what
4278 users expect at the shell prompt.
4280 Commands which accept locations, such as `disassemble', `print',
4281 `breakpoint', `until', etc. now complete on filenames as well as
4282 program symbols. Thus, if you type "break foob TAB", and the source
4283 files linked into the programs include `foobar.c', that file name will
4284 be one of the candidates for completion. However, file names are not
4285 considered for completion after you typed a colon that delimits a file
4286 name from a name of a function in that file, as in "break foo.c:bar".
4288 `set demangle-style' completes on available demangling styles.
4290 * New platform-independent commands:
4292 It is now possible to define a post-hook for a command as well as a
4293 hook that runs before the command. For more details, see the
4294 documentation of `hookpost' in the GDB manual.
4296 * Changes in GNU/Linux native debugging.
4298 Support for debugging multi-threaded programs has been completely
4299 revised for all platforms except m68k and sparc. You can now debug as
4300 many threads as your system allows you to have.
4302 Attach/detach is supported for multi-threaded programs.
4304 Support for SSE registers was added for x86. This doesn't work for
4305 multi-threaded programs though.
4307 * Changes in MIPS configurations.
4309 Multi-arch support is enabled for all MIPS configurations.
4311 GDB can now be built as native debugger on SGI Irix 6.x systems for
4312 debugging n32 executables. (Debugging 64-bit executables is not yet
4315 * Unified support for hardware watchpoints in all x86 configurations.
4317 Most (if not all) native x86 configurations support hardware-assisted
4318 breakpoints and watchpoints in a unified manner. This support
4319 implements debug register sharing between watchpoints, which allows to
4320 put a virtually infinite number of watchpoints on the same address,
4321 and also supports watching regions up to 16 bytes with several debug
4324 The new maintenance command `maintenance show-debug-regs' toggles
4325 debugging print-outs in functions that insert, remove, and test
4326 watchpoints and hardware breakpoints.
4328 * Changes in the DJGPP native configuration.
4330 New command ``info dos sysinfo'' displays assorted information about
4331 the CPU, OS, memory, and DPMI server.
4333 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4334 display information about segment descriptors stored in GDT, LDT, and
4337 New commands ``info dos pde'' and ``info dos pte'' display entries
4338 from Page Directory and Page Tables (for now works with CWSDPMI only).
4339 New command ``info dos address-pte'' displays the Page Table entry for
4340 a given linear address.
4342 GDB can now pass command lines longer than 126 characters to the
4343 program being debugged (requires an update to the libdbg.a library
4344 which is part of the DJGPP development kit).
4346 DWARF2 debug info is now supported.
4348 It is now possible to `step' and `next' through calls to `longjmp'.
4350 * Changes in documentation.
4352 All GDB documentation was converted to GFDL, the GNU Free
4353 Documentation License.
4355 Tracepoints-related commands are now fully documented in the GDB
4358 TUI, the Text-mode User Interface, is now documented in the manual.
4360 Tracepoints-related commands are now fully documented in the GDB
4363 The "GDB Internals" manual now has an index. It also includes
4364 documentation of `ui_out' functions, GDB coding standards, x86
4365 hardware watchpoints, and memory region attributes.
4367 * GDB's version number moved to ``version.in''
4369 The Makefile variable VERSION has been replaced by the file
4370 ``version.in''. People creating GDB distributions should update the
4371 contents of this file.
4375 GUD support is now a standard part of the EMACS distribution.
4377 *** Changes in GDB 5.0:
4379 * Improved support for debugging FP programs on x86 targets
4381 Unified and much-improved support for debugging floating-point
4382 programs on all x86 targets. In particular, ``info float'' now
4383 displays the FP registers in the same format on all x86 targets, with
4384 greater level of detail.
4386 * Improvements and bugfixes in hardware-assisted watchpoints
4388 It is now possible to watch array elements, struct members, and
4389 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4390 on x86 targets no longer erroneously trigger when the address is
4393 * Improvements in the native DJGPP version of GDB
4395 The distribution now includes all the scripts and auxiliary files
4396 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4397 machines ``out of the box''.
4399 The DJGPP version can now debug programs that use signals. It is
4400 possible to catch signals that happened in the debuggee, deliver
4401 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4402 would kill the program being debugged.) Programs that hook hardware
4403 interrupts (keyboard, timer, etc.) can also be debugged.
4405 It is now possible to debug DJGPP programs that redirect their
4406 standard handles or switch them to raw (as opposed to cooked) mode, or
4407 even close them. The command ``run < foo > bar'' works as expected,
4408 and ``info terminal'' reports useful information about the debuggee's
4409 terminal, including raw/cooked mode, redirection, etc.
4411 The DJGPP version now uses termios functions for console I/O, which
4412 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4415 DOS-style file names with drive letters are now fully supported by
4418 It is now possible to debug DJGPP programs that switch their working
4419 directory. It is also possible to rerun the debuggee any number of
4420 times without restarting GDB; thus, you can use the same setup,
4421 breakpoints, etc. for many debugging sessions.
4423 * New native configurations
4425 ARM GNU/Linux arm*-*-linux*
4426 PowerPC GNU/Linux powerpc-*-linux*
4430 Motorola MCore mcore-*-*
4431 x86 VxWorks i[3456]86-*-vxworks*
4432 PowerPC VxWorks powerpc-*-vxworks*
4433 TI TMS320C80 tic80-*-*
4435 * OBSOLETE configurations
4437 Altos 3068 m68*-altos-*
4438 Convex c1-*-*, c2-*-*
4440 ARM RISCix arm-*-* (as host)
4443 Configurations that have been declared obsolete will be commented out,
4444 but the code will be left in place. If there is no activity to revive
4445 these configurations before the next release of GDB, the sources will
4446 be permanently REMOVED.
4448 * Gould support removed
4450 Support for the Gould PowerNode and NP1 has been removed.
4452 * New features for SVR4
4454 On SVR4 native platforms (such as Solaris), if you attach to a process
4455 without first loading a symbol file, GDB will now attempt to locate and
4456 load symbols from the running process's executable file.
4458 * Many C++ enhancements
4460 C++ support has been greatly improved. Overload resolution now works properly
4461 in almost all cases. RTTI support is on the way.
4463 * Remote targets can connect to a sub-program
4465 A popen(3) style serial-device has been added. This device starts a
4466 sub-process (such as a stand-alone simulator) and then communicates
4467 with that. The sub-program to run is specified using the syntax
4468 ``|<program> <args>'' vis:
4470 (gdb) set remotedebug 1
4471 (gdb) target extended-remote |mn10300-elf-sim program-args
4473 * MIPS 64 remote protocol
4475 A long standing bug in the mips64 remote protocol where by GDB
4476 expected certain 32 bit registers (ex SR) to be transfered as 32
4477 instead of 64 bits has been fixed.
4479 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4480 added to provide backward compatibility with older versions of GDB.
4482 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4484 The command ``set remotebinarydownload'' command has been replaced by
4485 ``set remote X-packet''. Other commands in ``set remote'' family
4486 include ``set remote P-packet''.
4488 * Breakpoint commands accept ranges.
4490 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4491 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4492 ``tracepoint passcount'' also accepts a range of tracepoints.
4494 * ``apropos'' command added.
4496 The ``apropos'' command searches through command names and
4497 documentation strings, printing out matches, making it much easier to
4498 try to find a command that does what you are looking for.
4502 A new machine oriented interface (MI) has been added to GDB. This
4503 interface is designed for debug environments running GDB as a separate
4504 process. This is part of the long term libGDB project. See the
4505 "GDB/MI" chapter of the GDB manual for further information. It can be
4506 enabled by configuring with:
4508 .../configure --enable-gdbmi
4510 *** Changes in GDB-4.18:
4512 * New native configurations
4514 HP-UX 10.20 hppa*-*-hpux10.20
4515 HP-UX 11.x hppa*-*-hpux11.0*
4516 M68K GNU/Linux m68*-*-linux*
4520 Fujitsu FR30 fr30-*-elf*
4521 Intel StrongARM strongarm-*-*
4522 Mitsubishi D30V d30v-*-*
4524 * OBSOLETE configurations
4526 Gould PowerNode, NP1 np1-*-*, pn-*-*
4528 Configurations that have been declared obsolete will be commented out,
4529 but the code will be left in place. If there is no activity to revive
4530 these configurations before the next release of GDB, the sources will
4531 be permanently REMOVED.
4535 As a compatibility experiment, GDB's source files buildsym.h and
4536 buildsym.c have been converted to pure standard C, no longer
4537 containing any K&R compatibility code. We believe that all systems in
4538 use today either come with a standard C compiler, or have a GCC port
4539 available. If this is not true, please report the affected
4540 configuration to bug-gdb@gnu.org immediately. See the README file for
4541 information about getting a standard C compiler if you don't have one
4546 GDB now uses readline 2.2.
4548 * set extension-language
4550 You can now control the mapping between filename extensions and source
4551 languages by using the `set extension-language' command. For instance,
4552 you can ask GDB to treat .c files as C++ by saying
4553 set extension-language .c c++
4554 The command `info extensions' lists all of the recognized extensions
4555 and their associated languages.
4557 * Setting processor type for PowerPC and RS/6000
4559 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4560 you can use the `set processor' command to specify what variant of the
4561 PowerPC family you are debugging. The command
4565 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4566 following PowerPC and RS6000 variants:
4568 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4569 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4571 403GC IBM PowerPC 403GC
4572 505 Motorola PowerPC 505
4573 860 Motorola PowerPC 860 or 850
4574 601 Motorola PowerPC 601
4575 602 Motorola PowerPC 602
4576 603 Motorola/IBM PowerPC 603 or 603e
4577 604 Motorola PowerPC 604 or 604e
4578 750 Motorola/IBM PowerPC 750 or 750
4580 At the moment, this command just tells GDB what to name the
4581 special-purpose processor registers. Since almost all the affected
4582 registers are inaccessible to user-level programs, this command is
4583 only useful for remote debugging in its present form.
4587 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4588 more extensive support for HP-UX. Added features include shared
4589 library support, kernel threads and hardware watchpoints for 11.00,
4590 support for HP's ANSI C and C++ compilers, and a compatibility mode
4591 for xdb and dbx commands.
4595 HP's donation includes the new concept of catchpoints, which is a
4596 generalization of the old catch command. On HP-UX, it is now possible
4597 to catch exec, fork, and vfork, as well as library loading.
4599 This means that the existing catch command has changed; its first
4600 argument now specifies the type of catch to be set up. See the
4601 output of "help catch" for a list of catchpoint types.
4603 * Debugging across forks
4605 On HP-UX, you can choose which process to debug when a fork() happens
4610 HP has donated a curses-based terminal user interface (TUI). To get
4611 it, build with --enable-tui. Although this can be enabled for any
4612 configuration, at present it only works for native HP debugging.
4614 * GDB remote protocol additions
4616 A new protocol packet 'X' that writes binary data is now available.
4617 Default behavior is to try 'X', then drop back to 'M' if the stub
4618 fails to respond. The settable variable `remotebinarydownload'
4619 allows explicit control over the use of 'X'.
4621 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4622 full 64-bit address. The command
4624 set remoteaddresssize 32
4626 can be used to revert to the old behaviour. For existing remote stubs
4627 the change should not be noticed, as the additional address information
4630 In order to assist in debugging stubs, you may use the maintenance
4631 command `packet' to send any text string to the stub. For instance,
4633 maint packet heythere
4635 sends the packet "$heythere#<checksum>". Note that it is very easy to
4636 disrupt a debugging session by sending the wrong packet at the wrong
4639 The compare-sections command allows you to compare section data on the
4640 target to what is in the executable file without uploading or
4641 downloading, by comparing CRC checksums.
4643 * Tracing can collect general expressions
4645 You may now collect general expressions at tracepoints. This requires
4646 further additions to the target-side stub; see tracepoint.c and
4647 doc/agentexpr.texi for further details.
4649 * mask-address variable for Mips
4651 For Mips targets, you may control the zeroing of the upper 32 bits of
4652 a 64-bit address by entering `set mask-address on'. This is mainly
4653 of interest to users of embedded R4xxx and R5xxx processors.
4655 * Higher serial baud rates
4657 GDB's serial code now allows you to specify baud rates 57600, 115200,
4658 230400, and 460800 baud. (Note that your host system may not be able
4659 to achieve all of these rates.)
4663 The i960 configuration now includes an initial implementation of a
4664 builtin simulator, contributed by Jim Wilson.
4667 *** Changes in GDB-4.17:
4669 * New native configurations
4671 Alpha GNU/Linux alpha*-*-linux*
4672 Unixware 2.x i[3456]86-unixware2*
4673 Irix 6.x mips*-sgi-irix6*
4674 PowerPC GNU/Linux powerpc-*-linux*
4675 PowerPC Solaris powerpcle-*-solaris*
4676 Sparc GNU/Linux sparc-*-linux*
4677 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4681 Argonaut Risc Chip (ARC) arc-*-*
4682 Hitachi H8/300S h8300*-*-*
4683 Matsushita MN10200 w/simulator mn10200-*-*
4684 Matsushita MN10300 w/simulator mn10300-*-*
4685 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4686 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4687 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4688 Mitsubishi D10V w/simulator d10v-*-*
4689 Mitsubishi M32R/D w/simulator m32r-*-elf*
4690 Tsqware Sparclet sparclet-*-*
4691 NEC V850 w/simulator v850-*-*
4693 * New debugging protocols
4695 ARM with RDI protocol arm*-*-*
4696 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4697 DDB and LSI variants of PMON protocol mips*-*-*
4698 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4699 PowerPC with SDS protocol powerpc{,le}-*-eabi
4700 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4704 All configurations can now understand and use the DWARF 2 debugging
4705 format. The choice is automatic, if the symbol file contains DWARF 2
4710 GDB now includes basic Java language support. This support is
4711 only useful with Java compilers that produce native machine code.
4713 * solib-absolute-prefix and solib-search-path
4715 For SunOS and SVR4 shared libraries, you may now set the prefix for
4716 loading absolute shared library symbol files, and the search path for
4717 locating non-absolute shared library symbol files.
4719 * Live range splitting
4721 GDB can now effectively debug code for which GCC has performed live
4722 range splitting as part of its optimization. See gdb/doc/LRS for
4723 more details on the expected format of the stabs information.
4727 GDB's support for the GNU Hurd, including thread debugging, has been
4728 updated to work with current versions of the Hurd.
4732 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4733 instruction set. ARM GDB automatically detects when Thumb
4734 instructions are in use, and adjusts disassembly and backtracing
4739 GDB's MIPS target configurations now handle the MIP16 16-bit
4744 GDB now includes support for overlays; if an executable has been
4745 linked such that multiple sections are based at the same address, GDB
4746 will decide which section to use for symbolic info. You can choose to
4747 control the decision manually, using overlay commands, or implement
4748 additional target-side support and use "overlay load-target" to bring
4749 in the overlay mapping. Do "help overlay" for more detail.
4753 The command "info symbol <address>" displays information about
4754 the symbol at the specified address.
4758 The standard remote protocol now includes an extension that allows
4759 asynchronous collection and display of trace data. This requires
4760 extensive support in the target-side debugging stub. Tracing mode
4761 includes a new interaction mode in GDB and new commands: see the
4762 file tracepoint.c for more details.
4766 Configurations for embedded MIPS now include a simulator contributed
4767 by Cygnus Solutions. The simulator supports the instruction sets
4768 of most MIPS variants.
4772 Sparc configurations may now include the ERC32 simulator contributed
4773 by the European Space Agency. The simulator is not built into
4774 Sparc targets by default; configure with --enable-sim to include it.
4778 For target configurations that may include multiple variants of a
4779 basic architecture (such as MIPS and SH), you may now set the
4780 architecture explicitly. "set arch" sets, "info arch" lists
4781 the possible architectures.
4783 *** Changes in GDB-4.16:
4785 * New native configurations
4787 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4788 M68K NetBSD m68k-*-netbsd*
4789 PowerPC AIX 4.x powerpc-*-aix*
4790 PowerPC MacOS powerpc-*-macos*
4791 PowerPC Windows NT powerpcle-*-cygwin32
4792 RS/6000 AIX 4.x rs6000-*-aix4*
4796 ARM with RDP protocol arm-*-*
4797 I960 with MON960 i960-*-coff
4798 MIPS VxWorks mips*-*-vxworks*
4799 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4800 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4802 Matra Sparclet sparclet-*-*
4806 The powerpc-eabi configuration now includes the PSIM simulator,
4807 contributed by Andrew Cagney, with assistance from Mike Meissner.
4808 PSIM is a very elaborate model of the PowerPC, including not only
4809 basic instruction set execution, but also details of execution unit
4810 performance and I/O hardware. See sim/ppc/README for more details.
4814 GDB now works with Solaris 2.5.
4816 * Windows 95/NT native
4818 GDB will now work as a native debugger on Windows 95 and Windows NT.
4819 To build it from source, you must use the "gnu-win32" environment,
4820 which uses a DLL to emulate enough of Unix to run the GNU tools.
4821 Further information, binaries, and sources are available at
4822 ftp.cygnus.com, under pub/gnu-win32.
4824 * dont-repeat command
4826 If a user-defined command includes the command `dont-repeat', then the
4827 command will not be repeated if the user just types return. This is
4828 useful if the command is time-consuming to run, so that accidental
4829 extra keystrokes don't run the same command many times.
4831 * Send break instead of ^C
4833 The standard remote protocol now includes an option to send a break
4834 rather than a ^C to the target in order to interrupt it. By default,
4835 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4837 * Remote protocol timeout
4839 The standard remote protocol includes a new variable `remotetimeout'
4840 that allows you to set the number of seconds before GDB gives up trying
4841 to read from the target. The default value is 2.
4843 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4845 By default GDB will automatically keep track of objects as they are
4846 loaded and unloaded by the dynamic linker. By using the command `set
4847 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4848 when shared library events occur, thus allowing you to set breakpoints
4849 in shared libraries which are explicitly loaded by the inferior.
4851 Note this feature does not work on hpux8. On hpux9 you must link
4852 /usr/lib/end.o into your program. This feature should work
4853 automatically on hpux10.
4855 * Irix 5.x hardware watchpoint support
4857 Irix 5 configurations now support the use of hardware watchpoints.
4859 * Mips protocol "SYN garbage limit"
4861 When debugging a Mips target using the `target mips' protocol, you
4862 may set the number of characters that GDB will ignore by setting
4863 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4864 every character. The default value is 1050.
4866 * Recording and replaying remote debug sessions
4868 If you set `remotelogfile' to the name of a file, gdb will write to it
4869 a recording of a remote debug session. This recording may then be
4870 replayed back to gdb using "gdbreplay". See gdbserver/README for
4871 details. This is useful when you have a problem with GDB while doing
4872 remote debugging; you can make a recording of the session and send it
4873 to someone else, who can then recreate the problem.
4875 * Speedups for remote debugging
4877 GDB includes speedups for downloading and stepping MIPS systems using
4878 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4879 and more efficient S-record downloading.
4881 * Memory use reductions and statistics collection
4883 GDB now uses less memory and reports statistics about memory usage.
4884 Try the `maint print statistics' command, for example.
4886 *** Changes in GDB-4.15:
4888 * Psymtabs for XCOFF
4890 The symbol reader for AIX GDB now uses partial symbol tables. This
4891 can greatly improve startup time, especially for large executables.
4893 * Remote targets use caching
4895 Remote targets now use a data cache to speed up communication with the
4896 remote side. The data cache could lead to incorrect results because
4897 it doesn't know about volatile variables, thus making it impossible to
4898 debug targets which use memory mapped I/O devices. `set remotecache
4899 off' turns the the data cache off.
4901 * Remote targets may have threads
4903 The standard remote protocol now includes support for multiple threads
4904 in the target system, using new protocol commands 'H' and 'T'. See
4905 gdb/remote.c for details.
4909 If GDB is configured with `--enable-netrom', then it will include
4910 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4911 acts as though it is a bank of ROM on the target board, but you can
4912 write into it over the network. GDB's support consists only of
4913 support for fast loading into the emulated ROM; to debug, you must use
4914 another protocol, such as standard remote protocol. The usual
4915 sequence is something like
4917 target nrom <netrom-hostname>
4919 target remote <netrom-hostname>:1235
4923 GDB now includes support for the Apple Macintosh, as a host only. It
4924 may be run as either an MPW tool or as a standalone application, and
4925 it can debug through the serial port. All the usual GDB commands are
4926 available, but to the target command, you must supply "serial" as the
4927 device type instead of "/dev/ttyXX". See mpw-README in the main
4928 directory for more information on how to build. The MPW configuration
4929 scripts */mpw-config.in support only a few targets, and only the
4930 mips-idt-ecoff target has been tested.
4934 GDB configuration now uses autoconf. This is not user-visible,
4935 but does simplify configuration and building.
4939 GDB now supports hpux10.
4941 *** Changes in GDB-4.14:
4943 * New native configurations
4945 x86 FreeBSD i[345]86-*-freebsd
4946 x86 NetBSD i[345]86-*-netbsd
4947 NS32k NetBSD ns32k-*-netbsd
4948 Sparc NetBSD sparc-*-netbsd
4952 A29K VxWorks a29k-*-vxworks
4953 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4954 CPU32 EST-300 emulator m68*-*-est*
4955 PowerPC ELF powerpc-*-elf
4958 * Alpha OSF/1 support for procfs
4960 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4961 possible to attach to running processes. As the mounting of the /proc
4962 filesystem is optional on the Alpha, GDB automatically determines
4963 the availability of /proc during startup. This can lead to problems
4964 if /proc is unmounted after GDB has been started.
4966 * Arguments to user-defined commands
4968 User commands may accept up to 10 arguments separated by whitespace.
4969 Arguments are accessed within the user command via $arg0..$arg9. A
4972 print $arg0 + $arg1 + $arg2
4974 To execute the command use:
4977 Defines the command "adder" which prints the sum of its three arguments.
4978 Note the arguments are text substitutions, so they may reference variables,
4979 use complex expressions, or even perform inferior function calls.
4981 * New `if' and `while' commands
4983 This makes it possible to write more sophisticated user-defined
4984 commands. Both commands take a single argument, which is the
4985 expression to evaluate, and must be followed by the commands to
4986 execute, one per line, if the expression is nonzero, the list being
4987 terminated by the word `end'. The `if' command list may include an
4988 `else' word, which causes the following commands to be executed only
4989 if the expression is zero.
4991 * Fortran source language mode
4993 GDB now includes partial support for Fortran 77. It will recognize
4994 Fortran programs and can evaluate a subset of Fortran expressions, but
4995 variables and functions may not be handled correctly. GDB will work
4996 with G77, but does not yet know much about symbols emitted by other
4999 * Better HPUX support
5001 Most debugging facilities now work on dynamic executables for HPPAs
5002 running hpux9 or later. You can attach to running dynamically linked
5003 processes, but by default the dynamic libraries will be read-only, so
5004 for instance you won't be able to put breakpoints in them. To change
5005 that behavior do the following before running the program:
5011 This will cause the libraries to be mapped private and read-write.
5012 To revert to the normal behavior, do this:
5018 You cannot set breakpoints or examine data in the library until after
5019 the library is loaded if the function/data symbols do not have
5022 GDB can now also read debug symbols produced by the HP C compiler on
5023 HPPAs (sorry, no C++, Fortran or 68k support).
5025 * Target byte order now dynamically selectable
5027 You can choose which byte order to use with a target system, via the
5028 commands "set endian big" and "set endian little", and you can see the
5029 current setting by using "show endian". You can also give the command
5030 "set endian auto", in which case GDB will use the byte order
5031 associated with the executable. Currently, only embedded MIPS
5032 configurations support dynamic selection of target byte order.
5034 * New DOS host serial code
5036 This version uses DPMI interrupts to handle buffered I/O, so you
5037 no longer need to run asynctsr when debugging boards connected to
5040 *** Changes in GDB-4.13:
5042 * New "complete" command
5044 This lists all the possible completions for the rest of the line, if it
5045 were to be given as a command itself. This is intended for use by emacs.
5047 * Trailing space optional in prompt
5049 "set prompt" no longer adds a space for you after the prompt you set. This
5050 allows you to set a prompt which ends in a space or one that does not.
5052 * Breakpoint hit counts
5054 "info break" now displays a count of the number of times the breakpoint
5055 has been hit. This is especially useful in conjunction with "ignore"; you
5056 can ignore a large number of breakpoint hits, look at the breakpoint info
5057 to see how many times the breakpoint was hit, then run again, ignoring one
5058 less than that number, and this will get you quickly to the last hit of
5061 * Ability to stop printing at NULL character
5063 "set print null-stop" will cause GDB to stop printing the characters of
5064 an array when the first NULL is encountered. This is useful when large
5065 arrays actually contain only short strings.
5067 * Shared library breakpoints
5069 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5070 breakpoints in shared libraries before the executable is run.
5072 * Hardware watchpoints
5074 There is a new hardware breakpoint for the watch command for sparclite
5075 targets. See gdb/sparclite/hw_breakpoint.note.
5077 Hardware watchpoints are also now supported under GNU/Linux.
5081 Annotations have been added. These are for use with graphical interfaces,
5082 and are still experimental. Currently only gdba.el uses these.
5084 * Improved Irix 5 support
5086 GDB now works properly with Irix 5.2.
5088 * Improved HPPA support
5090 GDB now works properly with the latest GCC and GAS.
5092 * New native configurations
5094 Sequent PTX4 i[34]86-sequent-ptx4
5095 HPPA running OSF/1 hppa*-*-osf*
5096 Atari TT running SVR4 m68*-*-sysv4*
5097 RS/6000 LynxOS rs6000-*-lynxos*
5101 OS/9000 i[34]86-*-os9k
5102 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5105 * Hitachi SH7000 and E7000-PC ICE support
5107 There is now support for communicating with the Hitachi E7000-PC ICE.
5108 This is available automatically when GDB is configured for the SH.
5112 As usual, a variety of small fixes and improvements, both generic
5113 and configuration-specific. See the ChangeLog for more detail.
5115 *** Changes in GDB-4.12:
5117 * Irix 5 is now supported
5121 GDB-4.12 on the HPPA has a number of changes which make it unable
5122 to debug the output from the currently released versions of GCC and
5123 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5124 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5125 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5128 *** Changes in GDB-4.11:
5130 * User visible changes:
5134 The "set remotedebug" option is now consistent between the mips remote
5135 target, remote targets using the gdb-specific protocol, UDI (AMD's
5136 debug protocol for the 29k) and the 88k bug monitor. It is now an
5137 integer specifying a debug level (normally 0 or 1, but 2 means more
5138 debugging info for the mips target).
5140 * DEC Alpha native support
5142 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5143 debug info, but GDB works fairly well with the DEC compiler and should
5144 work with a future GCC release. See the README file for a few
5145 Alpha-specific notes.
5147 * Preliminary thread implementation
5149 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5151 * LynxOS native and target support for 386
5153 This release has been hosted on LynxOS 2.2, and also can be configured
5154 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5157 * Improvements in C++ mangling/demangling.
5159 This release has much better g++ debugging, specifically in name
5160 mangling/demangling, virtual function calls, print virtual table,
5161 call methods, ...etc.
5163 *** Changes in GDB-4.10:
5165 * User visible changes:
5167 Remote debugging using the GDB-specific (`target remote') protocol now
5168 supports the `load' command. This is only useful if you have some
5169 other way of getting the stub to the target system, and you can put it
5170 somewhere in memory where it won't get clobbered by the download.
5172 Filename completion now works.
5174 When run under emacs mode, the "info line" command now causes the
5175 arrow to point to the line specified. Also, "info line" prints
5176 addresses in symbolic form (as well as hex).
5178 All vxworks based targets now support a user settable option, called
5179 vxworks-timeout. This option represents the number of seconds gdb
5180 should wait for responses to rpc's. You might want to use this if
5181 your vxworks target is, perhaps, a slow software simulator or happens
5182 to be on the far side of a thin network line.
5186 This release contains support for using a DEC alpha as a GDB host for
5187 cross debugging. Native alpha debugging is not supported yet.
5190 *** Changes in GDB-4.9:
5194 This is the first GDB release which is accompanied by a matching testsuite.
5195 The testsuite requires installation of dejagnu, which should be available
5196 via ftp from most sites that carry GNU software.
5200 'Cfront' style demangling has had its name changed to 'ARM' style, to
5201 emphasize that it was written from the specifications in the C++ Annotated
5202 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5203 disclaimers, it still generated too much confusion with users attempting to
5204 use gdb with AT&T cfront.
5208 GDB now uses a standard remote interface to a simulator library.
5209 So far, the library contains simulators for the Zilog Z8001/2, the
5210 Hitachi H8/300, H8/500 and Super-H.
5212 * New targets supported
5214 H8/300 simulator h8300-hitachi-hms or h8300hms
5215 H8/500 simulator h8500-hitachi-hms or h8500hms
5216 SH simulator sh-hitachi-hms or sh
5217 Z8000 simulator z8k-zilog-none or z8ksim
5218 IDT MIPS board over serial line mips-idt-ecoff
5220 Cross-debugging to GO32 targets is supported. It requires a custom
5221 version of the i386-stub.c module which is integrated with the
5222 GO32 memory extender.
5224 * New remote protocols
5226 MIPS remote debugging protocol.
5228 * New source languages supported
5230 This version includes preliminary support for Chill, a Pascal like language
5231 used by telecommunications companies. Chill support is also being integrated
5232 into the GNU compiler, but we don't know when it will be publically available.
5235 *** Changes in GDB-4.8:
5237 * HP Precision Architecture supported
5239 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5240 version of this support was available as a set of patches from the
5241 University of Utah. GDB does not support debugging of programs
5242 compiled with the HP compiler, because HP will not document their file
5243 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5244 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5246 Many problems in the preliminary version have been fixed.
5248 * Faster and better demangling
5250 We have improved template demangling and fixed numerous bugs in the GNU style
5251 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5252 character types (wchar_t) are now supported. Demangling of each symbol is now
5253 only done once, and is cached when the symbol table for a file is read in.
5254 This results in a small increase in memory usage for C programs, a moderate
5255 increase in memory usage for C++ programs, and a fantastic speedup in
5258 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5259 from the specifications in the Annotated Reference Manual, which AT&T's
5260 compiler does not actually implement.
5262 * G++ multiple inheritance compiler problem
5264 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5265 inheritance lattices was reworked to properly discover ambiguities. We
5266 recently found an example which causes this new algorithm to fail in a
5267 very subtle way, producing bad debug information for those classes.
5268 The file 'gcc.patch' (in this directory) can be applied to gcc to
5269 circumvent the problem. A future GCC release will contain a complete
5272 The previous G++ debug info problem (mentioned below for the gdb-4.7
5273 release) is fixed in gcc version 2.3.2.
5275 * Improved configure script
5277 The `configure' script will now attempt to guess your system type if
5278 you don't supply a host system type. The old scheme of supplying a
5279 host system triplet is preferable over using this. All the magic is
5280 done in the new `config.guess' script. Examine it for details.
5282 We have also brought our configure script much more in line with the FSF's
5283 version. It now supports the --with-xxx options. In particular,
5284 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5285 The resulting GDB will not be able to read arbitrary object file formats --
5286 only the format ``expected'' to be used on the configured target system.
5287 We hope to make this the default in a future release.
5289 * Documentation improvements
5291 There's new internal documentation on how to modify GDB, and how to
5292 produce clean changes to the code. We implore people to read it
5293 before submitting changes.
5295 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5296 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5297 `info' files are also provided. To build `info' files from scratch,
5298 you will need the latest `makeinfo' release, which will be available in
5299 a future texinfo-X.Y release.
5301 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5302 We're not sure exactly which versions have this problem, but it has
5303 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5304 or better. If that isn't possible, there is a patch in
5305 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5306 around this problem.
5310 GDB now supports array constants that can be used in expressions typed in by
5311 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5312 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5315 The new directory `gdb/sparclite' contains a program that demonstrates
5316 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5318 * New native hosts supported
5320 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5321 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5323 * New targets supported
5325 AMD 29k family via UDI a29k-amd-udi or udi29k
5327 * New file formats supported
5329 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5330 HPUX core files, and SCO 3.2v2 core files.
5334 Attaching to processes now works again; thanks for the many bug reports.
5336 We have also stomped on a bunch of core dumps caused by
5337 printf_filtered("%s") problems.
5339 We eliminated a copyright problem on the rpc and ptrace header files
5340 for VxWorks, which was discovered at the last minute during the 4.7
5341 release. You should now be able to build a VxWorks GDB.
5343 You can now interrupt gdb while an attached process is running. This
5344 will cause the attached process to stop, and give control back to GDB.
5346 We fixed problems caused by using too many file descriptors
5347 for reading symbols from object files and libraries. This was
5348 especially a problem for programs that used many (~100) shared
5351 The `step' command now only enters a subroutine if there is line number
5352 information for the subroutine. Otherwise it acts like the `next'
5353 command. Previously, `step' would enter subroutines if there was
5354 any debugging information about the routine. This avoids problems
5355 when using `cc -g1' on MIPS machines.
5357 * Internal improvements
5359 GDB's internal interfaces have been improved to make it easier to support
5360 debugging of multiple languages in the future.
5362 GDB now uses a common structure for symbol information internally.
5363 Minimal symbols (derived from linkage symbols in object files), partial
5364 symbols (from a quick scan of debug information), and full symbols
5365 contain a common subset of information, making it easier to write
5366 shared code that handles any of them.
5368 * New command line options
5370 We now accept --silent as an alias for --quiet.
5374 The memory-mapped-malloc library is now licensed under the GNU Library
5375 General Public License.
5377 *** Changes in GDB-4.7:
5379 * Host/native/target split
5381 GDB has had some major internal surgery to untangle the support for
5382 hosts and remote targets. Now, when you configure GDB for a remote
5383 target, it will no longer load in all of the support for debugging
5384 local programs on the host. When fully completed and tested, this will
5385 ensure that arbitrary host/target combinations are possible.
5387 The primary conceptual shift is to separate the non-portable code in
5388 GDB into three categories. Host specific code is required any time GDB
5389 is compiled on that host, regardless of the target. Target specific
5390 code relates to the peculiarities of the target, but can be compiled on
5391 any host. Native specific code is everything else: it can only be
5392 built when the host and target are the same system. Child process
5393 handling and core file support are two common `native' examples.
5395 GDB's use of /proc for controlling Unix child processes is now cleaner.
5396 It has been split out into a single module under the `target_ops' vector,
5397 plus two native-dependent functions for each system that uses /proc.
5399 * New hosts supported
5401 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5402 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5403 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5405 * New targets supported
5407 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5408 68030 and CPU32 m68030-*-*, m68332-*-*
5410 * New native hosts supported
5412 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5413 (386bsd is not well tested yet)
5414 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5416 * New file formats supported
5418 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5419 supports reading of `a.out.adobe' object files, which are an a.out
5420 format extended with minimal information about multiple sections.
5424 `show copying' is the same as the old `info copying'.
5425 `show warranty' is the same as `info warrantee'.
5426 These were renamed for consistency. The old commands continue to work.
5428 `info handle' is a new alias for `info signals'.
5430 You can now define pre-command hooks, which attach arbitrary command
5431 scripts to any command. The commands in the hook will be executed
5432 prior to the user's command. You can also create a hook which will be
5433 executed whenever the program stops. See gdb.texinfo.
5437 We now deal with Cfront style name mangling, and can even extract type
5438 info from mangled symbols. GDB can automatically figure out which
5439 symbol mangling style your C++ compiler uses.
5441 Calling of methods and virtual functions has been improved as well.
5445 The crash that occured when debugging Sun Ansi-C compiled binaries is
5446 fixed. This was due to mishandling of the extra N_SO stabs output
5449 We also finally got Ultrix 4.2 running in house, and fixed core file
5450 support, with help from a dozen people on the net.
5452 John M. Farrell discovered that the reason that single-stepping was so
5453 slow on all of the Mips based platforms (primarily SGI and DEC) was
5454 that we were trying to demangle and lookup a symbol used for internal
5455 purposes on every instruction that was being stepped through. Changing
5456 the name of that symbol so that it couldn't be mistaken for a C++
5457 mangled symbol sped things up a great deal.
5459 Rich Pixley sped up symbol lookups in general by getting much smarter
5460 about when C++ symbol mangling is necessary. This should make symbol
5461 completion (TAB on the command line) much faster. It's not as fast as
5462 we'd like, but it's significantly faster than gdb-4.6.
5466 A new user controllable variable 'call_scratch_address' can
5467 specify the location of a scratch area to be used when GDB
5468 calls a function in the target. This is necessary because the
5469 usual method of putting the scratch area on the stack does not work
5470 in systems that have separate instruction and data spaces.
5472 We integrated changes to support the 29k UDI (Universal Debugger
5473 Interface), but discovered at the last minute that we didn't have all
5474 of the appropriate copyright paperwork. We are working with AMD to
5475 resolve this, and hope to have it available soon.
5479 We have sped up the remote serial line protocol, especially for targets
5480 with lots of registers. It now supports a new `expedited status' ('T')
5481 message which can be used in place of the existing 'S' status message.
5482 This allows the remote stub to send only the registers that GDB
5483 needs to make a quick decision about single-stepping or conditional
5484 breakpoints, eliminating the need to fetch the entire register set for
5485 each instruction being stepped through.
5487 The GDB remote serial protocol now implements a write-through cache for
5488 registers, only re-reading the registers if the target has run.
5490 There is also a new remote serial stub for SPARC processors. You can
5491 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5492 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5493 processor with a serial port.
5497 Configure.in files have become much easier to read and modify. A new
5498 `table driven' format makes it more obvious what configurations are
5499 supported, and what files each one uses.
5503 There is a new opcodes library which will eventually contain all of the
5504 disassembly routines and opcode tables. At present, it only contains
5505 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5506 disassembler (binutils/objdump) to share these routines.
5508 The libiberty library is now copylefted under the GNU Library General
5509 Public License. This allows more liberal use, and was done so libg++
5510 can use it. This makes no difference to GDB, since the Library License
5511 grants all the rights from the General Public License.
5515 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5516 reference to the stabs symbol info used by the debugger. It is (as far
5517 as we know) the only published document on this fascinating topic. We
5518 encourage you to read it, compare it to the stabs information on your
5519 system, and send improvements on the document in general (to
5520 bug-gdb@prep.ai.mit.edu).
5522 And, of course, many bugs have been fixed.
5525 *** Changes in GDB-4.6:
5527 * Better support for C++ function names
5529 GDB now accepts as input the "demangled form" of C++ overloaded function
5530 names and member function names, and can do command completion on such names
5531 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5532 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5533 Make use of command completion, it is your friend.
5535 GDB also now accepts a variety of C++ mangled symbol formats. They are
5536 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5537 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5538 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5539 for the list of formats.
5541 * G++ symbol mangling problem
5543 Recent versions of gcc have a bug in how they emit debugging information for
5544 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5545 directory) can be applied to gcc to fix the problem. Alternatively, if you
5546 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5547 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5548 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5551 * New 'maintenance' command
5553 All of the commands related to hacking GDB internals have been moved out of
5554 the main command set, and now live behind the 'maintenance' command. This
5555 can also be abbreviated as 'mt'. The following changes were made:
5557 dump-me -> maintenance dump-me
5558 info all-breakpoints -> maintenance info breakpoints
5559 printmsyms -> maintenance print msyms
5560 printobjfiles -> maintenance print objfiles
5561 printpsyms -> maintenance print psymbols
5562 printsyms -> maintenance print symbols
5564 The following commands are new:
5566 maintenance demangle Call internal GDB demangler routine to
5567 demangle a C++ link name and prints the result.
5568 maintenance print type Print a type chain for a given symbol
5570 * Change to .gdbinit file processing
5572 We now read the $HOME/.gdbinit file before processing the argv arguments
5573 (e.g. reading symbol files or core files). This allows global parameters to
5574 be set, which will apply during the symbol reading. The ./.gdbinit is still
5575 read after argv processing.
5577 * New hosts supported
5579 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5581 GNU/Linux support i386-unknown-linux or linux
5583 We are also including code to support the HP/PA running BSD and HPUX. This
5584 is almost guaranteed not to work, as we didn't have time to test or build it
5585 for this release. We are including it so that the more adventurous (or
5586 masochistic) of you can play with it. We also had major problems with the
5587 fact that the compiler that we got from HP doesn't support the -g option.
5590 * New targets supported
5592 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5594 * More smarts about finding #include files
5596 GDB now remembers the compilation directory for all include files, and for
5597 all files from which C is generated (like yacc and lex sources). This
5598 greatly improves GDB's ability to find yacc/lex sources, and include files,
5599 especially if you are debugging your program from a directory different from
5600 the one that contains your sources.
5602 We also fixed a bug which caused difficulty with listing and setting
5603 breakpoints in include files which contain C code. (In the past, you had to
5604 try twice in order to list an include file that you hadn't looked at before.)
5606 * Interesting infernals change
5608 GDB now deals with arbitrary numbers of sections, where the symbols for each
5609 section must be relocated relative to that section's landing place in the
5610 target's address space. This work was needed to support ELF with embedded
5611 stabs used by Solaris-2.0.
5613 * Bug fixes (of course!)
5615 There have been loads of fixes for the following things:
5616 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5617 i960, stabs, DOS(GO32), procfs, etc...
5619 See the ChangeLog for details.
5621 *** Changes in GDB-4.5:
5623 * New machines supported (host and target)
5625 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5627 SGI Irix-4.x mips-sgi-irix4 or iris4
5629 * New malloc package
5631 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5632 Mmalloc is capable of handling mutiple heaps of memory. It is also
5633 capable of saving a heap to a file, and then mapping it back in later.
5634 This can be used to greatly speedup the startup of GDB by using a
5635 pre-parsed symbol table which lives in a mmalloc managed heap. For
5636 more details, please read mmalloc/mmalloc.texi.
5640 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5641 'help info proc' for details.
5643 * MIPS ecoff symbol table format
5645 The code that reads MIPS symbol table format is now supported on all hosts.
5646 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5649 * File name changes for MS-DOS
5651 Many files in the config directories have been renamed to make it easier to
5652 support GDB on MS-DOSe systems (which have very restrictive file name
5653 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5654 environment) is close to working but has some remaining problems. Note
5655 that debugging of DOS programs is not supported, due to limitations
5656 in the ``operating system'', but it can be used to host cross-debugging.
5658 * Cross byte order fixes
5660 Many fixes have been made to support cross debugging of Sparc and MIPS
5661 targets from hosts whose byte order differs.
5663 * New -mapped and -readnow options
5665 If memory-mapped files are available on your system through the 'mmap'
5666 system call, you can use the -mapped option on the `file' or
5667 `symbol-file' commands to cause GDB to write the symbols from your
5668 program into a reusable file. If the program you are debugging is
5669 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5670 Future GDB debugging sessions will notice the presence of this file,
5671 and will quickly map in symbol information from it, rather than reading
5672 the symbol table from the executable program. Using the '-mapped'
5673 option in a GDB `file' or `symbol-file' command has the same effect as
5674 starting GDB with the '-mapped' command-line option.
5676 You can cause GDB to read the entire symbol table immediately by using
5677 the '-readnow' option with any of the commands that load symbol table
5678 information (or on the GDB command line). This makes the command
5679 slower, but makes future operations faster.
5681 The -mapped and -readnow options are typically combined in order to
5682 build a `fred.syms' file that contains complete symbol information.
5683 A simple GDB invocation to do nothing but build a `.syms' file for future
5686 gdb -batch -nx -mapped -readnow programname
5688 The `.syms' file is specific to the host machine on which GDB is run.
5689 It holds an exact image of GDB's internal symbol table. It cannot be
5690 shared across multiple host platforms.
5692 * longjmp() handling
5694 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5695 siglongjmp() without losing control. This feature has not yet been ported to
5696 all systems. It currently works on many 386 platforms, all MIPS-based
5697 platforms (SGI, DECstation, etc), and Sun3/4.
5701 Preliminary work has been put in to support the new Solaris OS from Sun. At
5702 this time, it can control and debug processes, but it is not capable of
5707 As always, many many bug fixes. The major areas were with g++, and mipsread.
5708 People using the MIPS-based platforms should experience fewer mysterious
5709 crashes and trashed symbol tables.
5711 *** Changes in GDB-4.4:
5713 * New machines supported (host and target)
5715 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5717 BSD Reno on Vax vax-dec-bsd
5718 Ultrix on Vax vax-dec-ultrix
5720 * New machines supported (target)
5722 AMD 29000 embedded, using EBMON a29k-none-none
5726 GDB continues to improve its handling of C++. `References' work better.
5727 The demangler has also been improved, and now deals with symbols mangled as
5728 per the Annotated C++ Reference Guide.
5730 GDB also now handles `stabs' symbol information embedded in MIPS
5731 `ecoff' symbol tables. Since the ecoff format was not easily
5732 extensible to handle new languages such as C++, this appeared to be a
5733 good way to put C++ debugging info into MIPS binaries. This option
5734 will be supported in the GNU C compiler, version 2, when it is
5737 * New features for SVR4
5739 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5740 shared libraries. Debugging dynamically linked programs should present
5741 only minor differences from debugging statically linked programs.
5743 The `info proc' command will print out information about any process
5744 on an SVR4 system (including the one you are debugging). At the moment,
5745 it prints the address mappings of the process.
5747 If you bring up GDB on another SVR4 system, please send mail to
5748 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5750 * Better dynamic linking support in SunOS
5752 Reading symbols from shared libraries which contain debugging symbols
5753 now works properly. However, there remain issues such as automatic
5754 skipping of `transfer vector' code during function calls, which
5755 make it harder to debug code in a shared library, than to debug the
5756 same code linked statically.
5760 GDB is now using the latest `getopt' routines from the FSF. This
5761 version accepts the -- prefix for options with long names. GDB will
5762 continue to accept the old forms (-option and +option) as well.
5763 Various single letter abbreviations for options have been explicity
5764 added to the option table so that they won't get overshadowed in the
5765 future by other options that begin with the same letter.
5769 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5770 Many assorted bugs have been handled. Many more remain to be handled.
5771 See the various ChangeLog files (primarily in gdb and bfd) for details.
5774 *** Changes in GDB-4.3:
5776 * New machines supported (host and target)
5778 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5779 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5780 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5782 * Almost SCO Unix support
5784 We had hoped to support:
5785 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5786 (except for core file support), but we discovered very late in the release
5787 that it has problems with process groups that render gdb unusable. Sorry
5788 about that. I encourage people to fix it and post the fixes.
5790 * Preliminary ELF and DWARF support
5792 GDB can read ELF object files on System V Release 4, and can handle
5793 debugging records for C, in DWARF format, in ELF files. This support
5794 is preliminary. If you bring up GDB on another SVR4 system, please
5795 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5800 GDB now uses the latest `readline' library. One user-visible change
5801 is that two tabs will list possible command completions, which previously
5802 required typing M-? (meta-question mark, or ESC ?).
5806 The `stepi' bug that many of you noticed has been squashed.
5807 Many bugs in C++ have been handled. Many more remain to be handled.
5808 See the various ChangeLog files (primarily in gdb and bfd) for details.
5810 * State of the MIPS world (in case you wondered):
5812 GDB can understand the symbol tables emitted by the compilers
5813 supplied by most vendors of MIPS-based machines, including DEC. These
5814 symbol tables are in a format that essentially nobody else uses.
5816 Some versions of gcc come with an assembler post-processor called
5817 mips-tfile. This program is required if you want to do source-level
5818 debugging of gcc-compiled programs. I believe FSF does not ship
5819 mips-tfile with gcc version 1, but it will eventually come with gcc
5822 Debugging of g++ output remains a problem. g++ version 1.xx does not
5823 really support it at all. (If you're lucky, you should be able to get
5824 line numbers and stack traces to work, but no parameters or local
5825 variables.) With some work it should be possible to improve the
5828 When gcc version 2 is released, you will have somewhat better luck.
5829 However, even then you will get confusing results for inheritance and
5832 We will eventually provide full debugging of g++ output on
5833 DECstations. This will probably involve some kind of stabs-in-ecoff
5834 encapulation, but the details have not been worked out yet.
5837 *** Changes in GDB-4.2:
5839 * Improved configuration
5841 Only one copy of `configure' exists now, and it is not self-modifying.
5842 Porting BFD is simpler.
5846 The `step' and `next' commands now only stop at the first instruction
5847 of a source line. This prevents the multiple stops that used to occur
5848 in switch statements, for-loops, etc. `Step' continues to stop if a
5849 function that has debugging information is called within the line.
5853 Lots of small bugs fixed. More remain.
5855 * New host supported (not target)
5857 Intel 386 PC clone running Mach i386-none-mach
5860 *** Changes in GDB-4.1:
5862 * Multiple source language support
5864 GDB now has internal scaffolding to handle several source languages.
5865 It determines the type of each source file from its filename extension,
5866 and will switch expression parsing and number formatting to match the
5867 language of the function in the currently selected stack frame.
5868 You can also specifically set the language to be used, with
5869 `set language c' or `set language modula-2'.
5873 GDB now has preliminary support for the GNU Modula-2 compiler,
5874 currently under development at the State University of New York at
5875 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5876 continue through the fall of 1991 and into 1992.
5878 Other Modula-2 compilers are currently not supported, and attempting to
5879 debug programs compiled with them will likely result in an error as the
5880 symbol table is read. Feel free to work on it, though!
5882 There are hooks in GDB for strict type checking and range checking,
5883 in the `Modula-2 philosophy', but they do not currently work.
5887 GDB can now write to executable and core files (e.g. patch
5888 a variable's value). You must turn this switch on, specify
5889 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5890 by assigning a new value to a variable. Modifications take
5893 * Automatic SunOS shared library reading
5895 When you run your program, GDB automatically determines where its
5896 shared libraries (if any) have been loaded, and reads their symbols.
5897 The `share' command is no longer needed. This also works when
5898 examining core files.
5902 You can specify the number of lines that the `list' command shows.
5905 * New machines supported (host and target)
5907 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5908 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5909 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5911 * New hosts supported (not targets)
5913 IBM RT/PC: romp-ibm-aix or rtpc
5915 * New targets supported (not hosts)
5917 AMD 29000 embedded with COFF a29k-none-coff
5918 AMD 29000 embedded with a.out a29k-none-aout
5919 Ultracomputer remote kernel debug a29k-nyu-kern
5921 * New remote interfaces
5927 *** Changes in GDB-4.0:
5931 Wide output is wrapped at good places to make the output more readable.
5933 Gdb now supports cross-debugging from a host machine of one type to a
5934 target machine of another type. Communication with the target system
5935 is over serial lines. The ``target'' command handles connecting to the
5936 remote system; the ``load'' command will download a program into the
5937 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5938 also supports debugging of realtime processes running under VxWorks,
5939 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5940 stub on the target system.
5942 New CPUs supported include the AMD 29000 and Intel 960.
5944 GDB now reads object files and symbol tables via a ``binary file''
5945 library, which allows a single copy of GDB to debug programs of multiple
5946 object file types such as a.out and coff.
5948 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5949 refcard.dvi and refcard.ps are available to format it).
5952 * Control-Variable user interface simplified
5954 All variables that control the operation of the debugger can be set
5955 by the ``set'' command, and displayed by the ``show'' command.
5957 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5958 ``Show prompt'' produces the response:
5959 Gdb's prompt is new-gdb=>.
5961 What follows are the NEW set commands. The command ``help set'' will
5962 print a complete list of old and new set commands. ``help set FOO''
5963 will give a longer description of the variable FOO. ``show'' will show
5964 all of the variable descriptions and their current settings.
5966 confirm on/off: Enables warning questions for operations that are
5967 hard to recover from, e.g. rerunning the program while
5968 it is already running. Default is ON.
5970 editing on/off: Enables EMACS style command line editing
5971 of input. Previous lines can be recalled with
5972 control-P, the current line can be edited with control-B,
5973 you can search for commands with control-R, etc.
5976 history filename NAME: NAME is where the gdb command history
5977 will be stored. The default is .gdb_history,
5978 or the value of the environment variable
5981 history size N: The size, in commands, of the command history. The
5982 default is 256, or the value of the environment variable
5985 history save on/off: If this value is set to ON, the history file will
5986 be saved after exiting gdb. If set to OFF, the
5987 file will not be saved. The default is OFF.
5989 history expansion on/off: If this value is set to ON, then csh-like
5990 history expansion will be performed on
5991 command line input. The default is OFF.
5993 radix N: Sets the default radix for input and output. It can be set
5994 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5995 in the current radix, so "set radix 10" is always a no-op.
5997 height N: This integer value is the number of lines on a page. Default
5998 is 24, the current `stty rows'' setting, or the ``li#''
5999 setting from the termcap entry matching the environment
6002 width N: This integer value is the number of characters on a line.
6003 Default is 80, the current `stty cols'' setting, or the ``co#''
6004 setting from the termcap entry matching the environment
6007 Note: ``set screensize'' is obsolete. Use ``set height'' and
6008 ``set width'' instead.
6010 print address on/off: Print memory addresses in various command displays,
6011 such as stack traces and structure values. Gdb looks
6012 more ``symbolic'' if you turn this off; it looks more
6013 ``machine level'' with it on. Default is ON.
6015 print array on/off: Prettyprint arrays. New convenient format! Default
6018 print demangle on/off: Print C++ symbols in "source" form if on,
6021 print asm-demangle on/off: Same, for assembler level printouts
6024 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6027 * Support for Epoch Environment.
6029 The epoch environment is a version of Emacs v18 with windowing. One
6030 new command, ``inspect'', is identical to ``print'', except that if you
6031 are running in the epoch environment, the value is printed in its own
6035 * Support for Shared Libraries
6037 GDB can now debug programs and core files that use SunOS shared libraries.
6038 Symbols from a shared library cannot be referenced
6039 before the shared library has been linked with the program (this
6040 happens after you type ``run'' and before the function main() is entered).
6041 At any time after this linking (including when examining core files
6042 from dynamically linked programs), gdb reads the symbols from each
6043 shared library when you type the ``sharedlibrary'' command.
6044 It can be abbreviated ``share''.
6046 sharedlibrary REGEXP: Load shared object library symbols for files
6047 matching a unix regular expression. No argument
6048 indicates to load symbols for all shared libraries.
6050 info sharedlibrary: Status of loaded shared libraries.
6055 A watchpoint stops execution of a program whenever the value of an
6056 expression changes. Checking for this slows down execution
6057 tremendously whenever you are in the scope of the expression, but is
6058 quite useful for catching tough ``bit-spreader'' or pointer misuse
6059 problems. Some machines such as the 386 have hardware for doing this
6060 more quickly, and future versions of gdb will use this hardware.
6062 watch EXP: Set a watchpoint (breakpoint) for an expression.
6064 info watchpoints: Information about your watchpoints.
6066 delete N: Deletes watchpoint number N (same as breakpoints).
6067 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6068 enable N: Re-enables watchpoint number N (same as breakpoints).
6071 * C++ multiple inheritance
6073 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6076 * C++ exception handling
6078 Gdb now supports limited C++ exception handling. Besides the existing
6079 ability to breakpoint on an exception handler, gdb can breakpoint on
6080 the raising of an exception (before the stack is peeled back to the
6083 catch FOO: If there is a FOO exception handler in the dynamic scope,
6084 set a breakpoint to catch exceptions which may be raised there.
6085 Multiple exceptions (``catch foo bar baz'') may be caught.
6087 info catch: Lists all exceptions which may be caught in the
6088 current stack frame.
6091 * Minor command changes
6093 The command ``call func (arg, arg, ...)'' now acts like the print
6094 command, except it does not print or save a value if the function's result
6095 is void. This is similar to dbx usage.
6097 The ``up'' and ``down'' commands now always print the frame they end up
6098 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6099 frames without printing.
6101 * New directory command
6103 'dir' now adds directories to the FRONT of the source search path.
6104 The path starts off empty. Source files that contain debug information
6105 about the directory in which they were compiled can be found even
6106 with an empty path; Sun CC and GCC include this information. If GDB can't
6107 find your source file in the current directory, type "dir .".
6109 * Configuring GDB for compilation
6111 For normal use, type ``./configure host''. See README or gdb.texinfo
6114 GDB now handles cross debugging. If you are remotely debugging between
6115 two different machines, type ``./configure host -target=targ''.
6116 Host is the machine where GDB will run; targ is the machine
6117 where the program that you are debugging will run.