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.
96 Renamed from "set debug dwarf2-die".
98 Renamed from "show debug dwarf2-die".
101 Renamed from "set debug dwarf2-read".
102 show debug dwarf-read
103 Renamed from "show debug dwarf2-read".
105 maint set dwarf always-disassemble
106 Renamed from "maint set dwarf2 always-disassemble".
107 maint show dwarf always-disassemble
108 Renamed from "maint show dwarf2 always-disassemble".
110 maint set dwarf max-cache-age
111 Renamed from "maint set dwarf2 max-cache-age".
112 maint show dwarf max-cache-age
113 Renamed from "maint show dwarf2 max-cache-age".
117 Set the maximum number of candidates to be considered during
118 completion. The default value is 200. This limit allows GDB
119 to avoid generating large completion lists, the computation of
120 which can cause the debugger to become temporarily unresponsive.
122 maint set symbol-cache-size
123 maint show symbol-cache-size
124 Control the size of the symbol cache.
126 set|show record btrace bts buffer-size
127 Set and show the size of the ring buffer used for branch tracing in
129 The obtained size may differ from the requested size. Use "info
130 record" to see the obtained buffer size.
132 * The command 'thread apply all' can now support new option '-ascending'
133 to call its specified command for all threads in ascending order.
135 * Python/Guile scripting
137 ** GDB now supports auto-loading of Python/Guile scripts contained in the
138 special section named `.debug_gdb_scripts'.
142 qXfer:btrace-conf:read
143 Return the branch trace configuration for the current thread.
145 Qbtrace-conf:bts:size
146 Set the requested ring buffer size for branch tracing in BTS format.
149 Indicates a memory breakpoint instruction was executed, irrespective
150 of whether it was GDB that planted the breakpoint or the breakpoint
151 is hardcoded in the program. This is required for correct non-stop
155 Indicates the target stopped for a hardware breakpoint. This is
156 required for correct non-stop mode operation.
159 Return information about files on the remote system.
162 Return the full absolute name of the file that was executed to
163 create a process running on the remote system.
166 Indicates that a fork system call was executed.
169 Indicates that a vfork system call was executed.
171 vforkdone stop reason
172 Indicates that a vfork child of the specified process has executed
173 an exec or exit, allowing the vfork parent to resume execution.
175 fork-events and vfork-events features in qSupported
176 The qSupported packet allows GDB to request support for fork and
177 vfork events using new 'gdbfeatures' fork-events and vfork-events,
178 and the qSupported response can contain the corresponding
179 'stubfeatures'. Set and show commands can be used to display
180 whether these features are enabled.
182 * Extended-remote fork events
184 ** GDB now has support for fork events on extended-remote Linux
185 targets. For targets with Linux kernels 2.5.60 and later, this
186 enables follow-fork-mode and detach-on-fork for both fork and
187 vfork, as well as fork and vfork catchpoints.
189 * The info record command now shows the recording format and the
190 branch tracing configuration for the current thread when using
191 the btrace record target.
192 For the BTS format, it shows the ring buffer size.
194 * GDB now has support for DTrace USDT (Userland Static Defined
195 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
197 * GDB now supports access to vector registers on S/390 GNU/Linux
200 * Removed command line options
202 -xdb HP-UX XDB compatibility mode.
204 * Removed targets and native configurations
206 HP/PA running HP-UX hppa*-*-hpux*
207 Itanium running HP-UX ia64-*-hpux*
209 *** Changes in GDB 7.9.1
213 ** Xmethods can now specify a result type.
215 *** Changes in GDB 7.9
217 * GDB now supports hardware watchpoints on x86 GNU Hurd.
221 ** You can now access frame registers from Python scripts.
222 ** New attribute 'producer' for gdb.Symtab objects.
223 ** gdb.Objfile objects have a new attribute "progspace",
224 which is the gdb.Progspace object of the containing program space.
225 ** gdb.Objfile objects have a new attribute "owner".
226 ** gdb.Objfile objects have a new attribute "build_id",
227 which is the build ID generated when the file was built.
228 ** gdb.Objfile objects have a new method "add_separate_debug_file".
229 ** A new event "gdb.clear_objfiles" has been added, triggered when
230 selecting a new file to debug.
231 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
232 ** New function gdb.lookup_objfile.
234 New events which are triggered when GDB modifies the state of the
237 ** gdb.events.inferior_call_pre: Function call is about to be made.
238 ** gdb.events.inferior_call_post: Function call has just been made.
239 ** gdb.events.memory_changed: A memory location has been altered.
240 ** gdb.events.register_changed: A register has been altered.
242 * New Python-based convenience functions:
244 ** $_caller_is(name [, number_of_frames])
245 ** $_caller_matches(regexp [, number_of_frames])
246 ** $_any_caller_is(name [, number_of_frames])
247 ** $_any_caller_matches(regexp [, number_of_frames])
249 * GDB now supports the compilation and injection of source code into
250 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
251 to compile the source code to object code, and if successful, inject
252 and execute that code within the current context of the inferior.
253 Currently the C language is supported. The commands used to
254 interface with this new feature are:
256 compile code [-raw|-r] [--] [source code]
257 compile file [-raw|-r] filename
261 demangle [-l language] [--] name
262 Demangle "name" in the specified language, or the current language
263 if elided. This command is renamed from the "maint demangle" command.
264 The latter is kept as a no-op to avoid "maint demangle" being interpreted
265 as "maint demangler-warning".
267 queue-signal signal-name-or-number
268 Queue a signal to be delivered to the thread when it is resumed.
270 add-auto-load-scripts-directory directory
271 Add entries to the list of directories from which to load auto-loaded
274 maint print user-registers
275 List all currently available "user" registers.
277 compile code [-r|-raw] [--] [source code]
278 Compile, inject, and execute in the inferior the executable object
279 code produced by compiling the provided source code.
281 compile file [-r|-raw] filename
282 Compile and inject into the inferior the executable object code
283 produced by compiling the source code stored in the filename
286 * On resume, GDB now always passes the signal the program had stopped
287 for to the thread the signal was sent to, even if the user changed
288 threads before resuming. Previously GDB would often (but not
289 always) deliver the signal to the thread that happens to be current
292 * Conversely, the "signal" command now consistently delivers the
293 requested signal to the current thread. GDB now asks for
294 confirmation if the program had stopped for a signal and the user
295 switched threads meanwhile.
297 * "breakpoint always-inserted" modes "off" and "auto" merged.
299 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
300 won't remove breakpoints from the target until all threads stop,
301 even in non-stop mode. The "auto" mode has been removed, and "off"
302 is now the default mode.
306 set debug symbol-lookup
307 show debug symbol-lookup
308 Control display of debugging info regarding symbol lookup.
312 ** The -list-thread-groups command outputs an exit-code field for
313 inferiors that have exited.
317 MIPS SDE mips*-sde*-elf*
321 Support for these obsolete configurations has been removed.
323 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
324 SGI Irix-5.x mips-*-irix5*
325 SGI Irix-6.x mips-*-irix6*
326 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
327 VAX running Ultrix vax-*-ultrix*
329 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
330 and "assf"), have been removed. Use the "sharedlibrary" command, or
331 its alias "share", instead.
333 *** Changes in GDB 7.8
335 * New command line options
338 This is an alias for the --data-directory option.
340 * GDB supports printing and modifying of variable length automatic arrays
341 as specified in ISO C99.
343 * The ARM simulator now supports instruction level tracing
344 with or without disassembly.
348 GDB now has support for scripting using Guile. Whether this is
349 available is determined at configure time.
350 Guile version 2.0 or greater is required.
351 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
353 * New commands (for set/show, see "New options" below)
357 Invoke CODE by passing it to the Guile interpreter.
361 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
363 info auto-load guile-scripts [regexp]
364 Print the list of automatically loaded Guile scripts.
366 * The source command is now capable of sourcing Guile scripts.
367 This feature is dependent on the debugger being built with Guile support.
371 set print symbol-loading (off|brief|full)
372 show print symbol-loading
373 Control whether to print informational messages when loading symbol
374 information for a file. The default is "full", but when debugging
375 programs with large numbers of shared libraries the amount of output
378 set guile print-stack (none|message|full)
379 show guile print-stack
380 Show a stack trace when an error is encountered in a Guile script.
382 set auto-load guile-scripts (on|off)
383 show auto-load guile-scripts
384 Control auto-loading of Guile script files.
386 maint ada set ignore-descriptive-types (on|off)
387 maint ada show ignore-descriptive-types
388 Control whether the debugger should ignore descriptive types in Ada
389 programs. The default is not to ignore the descriptive types. See
390 the user manual for more details on descriptive types and the intended
391 usage of this option.
393 set auto-connect-native-target
395 Control whether GDB is allowed to automatically connect to the
396 native target for the run, attach, etc. commands when not connected
397 to any target yet. See also "target native" below.
399 set record btrace replay-memory-access (read-only|read-write)
400 show record btrace replay-memory-access
401 Control what memory accesses are allowed during replay.
403 maint set target-async (on|off)
404 maint show target-async
405 This controls whether GDB targets operate in synchronous or
406 asynchronous mode. Normally the default is asynchronous, if it is
407 available; but this can be changed to more easily debug problems
408 occurring only in synchronous mode.
410 set mi-async (on|off)
412 Control whether MI asynchronous mode is preferred. This supersedes
413 "set target-async" of previous GDB versions.
415 * "set target-async" is deprecated as a CLI option and is now an alias
416 for "set mi-async" (only puts MI into async mode).
418 * Background execution commands (e.g., "c&", "s&", etc.) are now
419 possible ``out of the box'' if the target supports them. Previously
420 the user would need to explicitly enable the possibility with the
421 "set target-async on" command.
423 * New features in the GDB remote stub, GDBserver
425 ** New option --debug-format=option1[,option2,...] allows one to add
426 additional text to each output. At present only timestamps
427 are supported: --debug-format=timestamps.
428 Timestamps can also be turned on with the
429 "monitor set debug-format timestamps" command from GDB.
431 * The 'record instruction-history' command now starts counting instructions
432 at one. This also affects the instruction ranges reported by the
433 'record function-call-history' command when given the /i modifier.
435 * The command 'record function-call-history' supports a new modifier '/c' to
436 indent the function names based on their call stack depth.
437 The fields for the '/i' and '/l' modifier have been reordered.
438 The source line range is now prefixed with 'at'.
439 The instruction range is now prefixed with 'inst'.
440 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
441 "record instruction-history" and "list" commands.
443 * The ranges given as arguments to the 'record function-call-history' and
444 'record instruction-history' commands are now inclusive.
446 * The btrace record target now supports the 'record goto' command.
447 For locations inside the execution trace, the back trace is computed
448 based on the information stored in the execution trace.
450 * The btrace record target supports limited reverse execution and replay.
451 The target does not record data and therefore does not allow reading
454 * The "catch syscall" command now works on s390*-linux* targets.
456 * The "compare-sections" command is no longer specific to target
457 remote. It now works with all targets.
459 * All native targets are now consistently called "native".
460 Consequently, the "target child", "target GNU", "target djgpp",
461 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
462 commands have been replaced with "target native". The QNX/NTO port
463 leaves the "procfs" target in place and adds a "native" target for
464 consistency with other ports. The impact on users should be minimal
465 as these commands previously either throwed an error, or were
466 no-ops. The target's name is visible in the output of the following
467 commands: "help target", "info target", "info files", "maint print
470 * The "target native" command now connects to the native target. This
471 can be used to launch native programs even when "set
472 auto-connect-native-target" is set to off.
474 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.
476 * Support for Intel(R) AVX-512 registers on GNU/Linux.
477 Support displaying and modifying Intel(R) AVX-512 registers
478 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
482 qXfer:btrace:read's annex
483 The qXfer:btrace:read packet supports a new annex 'delta' to read
484 branch trace incrementally.
488 ** Valid Python operations on gdb.Value objects representing
489 structs/classes invoke the corresponding overloaded operators if
491 ** New `Xmethods' feature in the Python API. Xmethods are
492 additional methods or replacements for existing methods of a C++
493 class. This feature is useful for those cases where a method
494 defined in C++ source code could be inlined or optimized out by
495 the compiler, making it unavailable to GDB.
498 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
500 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
501 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
502 its alias "share", instead.
504 * The commands "set remotebaud" and "show remotebaud" are no longer
505 supported. Use "set serial baud" and "show serial baud" (respectively)
510 ** A new option "-gdb-set mi-async" replaces "-gdb-set
511 target-async". The latter is left as a deprecated alias of the
512 former for backward compatibility. If the target supports it,
513 CLI background execution commands are now always possible by
514 default, independently of whether the frontend stated a
515 preference for asynchronous execution with "-gdb-set mi-async".
516 Previously "-gdb-set target-async off" affected both MI execution
517 commands and CLI execution commands.
519 *** Changes in GDB 7.7
521 * Improved support for process record-replay and reverse debugging on
522 arm*-linux* targets. Support for thumb32 and syscall instruction
523 recording has been added.
525 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
527 * GDB now supports Fission DWP file format version 2.
528 http://gcc.gnu.org/wiki/DebugFission
530 * New convenience function "$_isvoid", to check whether an expression
531 is void. A void expression is an expression where the type of the
532 result is "void". For example, some convenience variables may be
533 "void" when evaluated (e.g., "$_exitcode" before the execution of
534 the program being debugged; or an undefined convenience variable).
535 Another example, when calling a function whose return type is
538 * The "maintenance print objfiles" command now takes an optional regexp.
540 * The "catch syscall" command now works on arm*-linux* targets.
542 * GDB now consistently shows "<not saved>" when printing values of
543 registers the debug info indicates have not been saved in the frame
544 and there's nowhere to retrieve them from
545 (callee-saved/call-clobbered registers):
550 (gdb) info registers rax
553 Before, the former would print "<optimized out>", and the latter
554 "*value not available*".
556 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
561 ** Frame filters and frame decorators have been added.
562 ** Temporary breakpoints are now supported.
563 ** Line tables representation has been added.
564 ** New attribute 'parent_type' for gdb.Field objects.
565 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
566 ** New attribute 'name' for gdb.Type objects.
570 Nios II ELF nios2*-*-elf
571 Nios II GNU/Linux nios2*-*-linux
572 Texas Instruments MSP430 msp430*-*-elf
574 * Removed native configurations
576 Support for these a.out NetBSD and OpenBSD obsolete configurations has
577 been removed. ELF variants of these configurations are kept supported.
579 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
580 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
581 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
582 i[34567]86-*-openbsd3.[0-3]
583 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
584 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
585 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
589 Like "catch throw", but catches a re-thrown exception.
591 Renamed from old "maint check-symtabs".
593 Perform consistency checks on symtabs.
595 Expand symtabs matching an optional regexp.
598 Display the details of GDB configure-time options.
600 maint set|show per-command
601 maint set|show per-command space
602 maint set|show per-command time
603 maint set|show per-command symtab
604 Enable display of per-command gdb resource usage.
606 remove-symbol-file FILENAME
607 remove-symbol-file -a ADDRESS
608 Remove a symbol file added via add-symbol-file. The file to remove
609 can be identified by its filename or by an address that lies within
610 the boundaries of this symbol file in memory.
613 info exceptions REGEXP
614 Display the list of Ada exceptions defined in the program being
615 debugged. If provided, only the exceptions whose names match REGEXP
620 set debug symfile off|on
622 Control display of debugging info regarding reading symbol files and
623 symbol tables within those files
625 set print raw frame-arguments
626 show print raw frame-arguments
627 Set/show whether to print frame arguments in raw mode,
628 disregarding any defined pretty-printers.
630 set remote trace-status-packet
631 show remote trace-status-packet
632 Set/show the use of remote protocol qTStatus packet.
636 Control display of debugging messages related to Nios II targets.
640 Control whether target-assisted range stepping is enabled.
642 set startup-with-shell
643 show startup-with-shell
644 Specifies whether Unix child processes are started via a shell or
649 Use the target memory cache for accesses to the code segment. This
650 improves performance of remote debugging (particularly disassembly).
652 * You can now use a literal value 'unlimited' for options that
653 interpret 0 or -1 as meaning "unlimited". E.g., "set
654 trace-buffer-size unlimited" is now an alias for "set
655 trace-buffer-size -1" and "set height unlimited" is now an alias for
658 * The "set debug symtab-create" debugging option of GDB has been changed to
659 accept a verbosity level. 0 means "off", 1 provides basic debugging
660 output, and values of 2 or greater provides more verbose output.
662 * New command-line options
664 Display the details of GDB configure-time options.
666 * The command 'tsave' can now support new option '-ctf' to save trace
667 buffer in Common Trace Format.
669 * Newly installed $prefix/bin/gcore acts as a shell interface for the
672 * GDB now implements the the C++ 'typeid' operator.
674 * The new convenience variable $_exception holds the exception being
675 thrown or caught at an exception-related catchpoint.
677 * The exception-related catchpoints, like "catch throw", now accept a
678 regular expression which can be used to filter exceptions by type.
680 * The new convenience variable $_exitsignal is automatically set to
681 the terminating signal number when the program being debugged dies
682 due to an uncaught signal.
686 ** All MI commands now accept an optional "--language" option.
687 Support for this feature can be verified by using the "-list-features"
688 command, which should contain "language-option".
690 ** The new command -info-gdb-mi-command allows the user to determine
691 whether a GDB/MI command is supported or not.
693 ** The "^error" result record returned when trying to execute an undefined
694 GDB/MI command now provides a variable named "code" whose content is the
695 "undefined-command" error code. Support for this feature can be verified
696 by using the "-list-features" command, which should contain
697 "undefined-command-error-code".
699 ** The -trace-save MI command can optionally save trace buffer in Common
702 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
704 ** The command -data-list-register-values now accepts an optional
705 "--skip-unavailable" option. When used, only the available registers
708 ** The new command -trace-frame-collected dumps collected variables,
709 computed expressions, tvars, memory and registers in a traceframe.
711 ** The commands -stack-list-locals, -stack-list-arguments and
712 -stack-list-variables now accept an option "--skip-unavailable".
713 When used, only the available locals or arguments are displayed.
715 ** The -exec-run command now accepts an optional "--start" option.
716 When used, the command follows the same semantics as the "start"
717 command, stopping the program's execution at the start of its
718 main subprogram. Support for this feature can be verified using
719 the "-list-features" command, which should contain
720 "exec-run-start-option".
722 ** The new commands -catch-assert and -catch-exceptions insert
723 catchpoints stopping the program when Ada exceptions are raised.
725 ** The new command -info-ada-exceptions provides the equivalent of
726 the new "info exceptions" command.
728 * New system-wide configuration scripts
729 A GDB installation now provides scripts suitable for use as system-wide
730 configuration scripts for the following systems:
734 * GDB now supports target-assigned range stepping with remote targets.
735 This improves the performance of stepping source lines by reducing
736 the number of control packets from/to GDB. See "New remote packets"
739 * GDB now understands the element 'tvar' in the XML traceframe info.
740 It has the id of the collected trace state variables.
742 * On S/390 targets that provide the transactional-execution feature,
743 the program interruption transaction diagnostic block (TDB) is now
744 represented as a number of additional "registers" in GDB.
750 The vCont packet supports a new 'r' action, that tells the remote
751 stub to step through an address range itself, without GDB
752 involvemement at each single-step.
754 qXfer:libraries-svr4:read's annex
755 The previously unused annex of the qXfer:libraries-svr4:read packet
756 is now used to support passing an argument list. The remote stub
757 reports support for this argument list to GDB's qSupported query.
758 The defined arguments are "start" and "prev", used to reduce work
759 necessary for library list updating, resulting in significant
762 * New features in the GDB remote stub, GDBserver
764 ** GDBserver now supports target-assisted range stepping. Currently
765 enabled on x86/x86_64 GNU/Linux targets.
767 ** GDBserver now adds element 'tvar' in the XML in the reply to
768 'qXfer:traceframe-info:read'. It has the id of the collected
769 trace state variables.
771 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
774 * New 'z' formatter for printing and examining memory, this displays the
775 value as hexadecimal zero padded on the left to the size of the type.
777 * GDB can now use Windows x64 unwinding data.
779 * The "set remotebaud" command has been replaced by "set serial baud".
780 Similarly, "show remotebaud" has been replaced by "show serial baud".
781 The "set remotebaud" and "show remotebaud" commands are still available
782 to provide backward compatibility with older versions of GDB.
784 *** Changes in GDB 7.6
786 * Target record has been renamed to record-full.
787 Record/replay is now enabled with the "record full" command.
788 This also affects settings that are associated with full record/replay
789 that have been moved from "set/show record" to "set/show record full":
791 set|show record full insn-number-max
792 set|show record full stop-at-limit
793 set|show record full memory-query
795 * A new record target "record-btrace" has been added. The new target
796 uses hardware support to record the control-flow of a process. It
797 does not support replaying the execution, but it implements the
798 below new commands for investigating the recorded execution log.
799 This new recording method can be enabled using:
803 The "record-btrace" target is only available on Intel Atom processors
804 and requires a Linux kernel 2.6.32 or later.
806 * Two new commands have been added for record/replay to give information
807 about the recorded execution without having to replay the execution.
808 The commands are only supported by "record btrace".
810 record instruction-history prints the execution history at
811 instruction granularity
813 record function-call-history prints the execution history at
816 * New native configurations
818 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
819 FreeBSD/powerpc powerpc*-*-freebsd
820 x86_64/Cygwin x86_64-*-cygwin*
821 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
825 ARM AArch64 aarch64*-*-elf
826 ARM AArch64 GNU/Linux aarch64*-*-linux
827 Lynx 178 PowerPC powerpc-*-lynx*178
828 x86_64/Cygwin x86_64-*-cygwin*
829 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
831 * If the configured location of system.gdbinit file (as given by the
832 --with-system-gdbinit option at configure time) is in the
833 data-directory (as specified by --with-gdb-datadir at configure
834 time) or in one of its subdirectories, then GDB will look for the
835 system-wide init file in the directory specified by the
836 --data-directory command-line option.
838 * New command line options:
840 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
841 other initialization files, unlike -nx which disables all of them.
843 * Removed command line options
845 -epoch This was used by the gdb mode in Epoch, an ancient fork of
848 * The 'ptype' and 'whatis' commands now accept an argument to control
851 * 'info proc' now works on some core files.
855 ** Vectors can be created with gdb.Type.vector.
857 ** Python's atexit.register now works in GDB.
859 ** Types can be pretty-printed via a Python API.
861 ** Python 3 is now supported (in addition to Python 2.4 or later)
863 ** New class gdb.Architecture exposes GDB's internal representation
864 of architecture in the Python API.
866 ** New method Frame.architecture returns the gdb.Architecture object
867 corresponding to the frame's architecture.
869 * New Python-based convenience functions:
871 ** $_memeq(buf1, buf2, length)
872 ** $_streq(str1, str2)
874 ** $_regex(str, regex)
876 * The 'cd' command now defaults to using '~' (the home directory) if not
879 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
880 default for GCC since November 2000.
882 * The command 'forward-search' can now be abbreviated as 'fo'.
884 * The command 'info tracepoints' can now display 'installed on target'
885 or 'not installed on target' for each non-pending location of tracepoint.
887 * New configure options
889 --enable-libmcheck/--disable-libmcheck
890 By default, development versions are built with -lmcheck on hosts
891 that support it, in order to help track memory corruption issues.
892 Release versions, on the other hand, are built without -lmcheck
893 by default. The --enable-libmcheck/--disable-libmcheck configure
894 options allow the user to override that default.
895 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
896 This configure option allows the user to build GDB with
897 libbabeltrace using which GDB can read Common Trace Format data.
899 * New commands (for set/show, see "New options" below)
902 Catch signals. This is similar to "handle", but allows commands and
903 conditions to be attached.
906 List the BFDs known to GDB.
908 python-interactive [command]
910 Start a Python interactive prompt, or evaluate the optional command
911 and print the result of expressions.
914 "py" is a new alias for "python".
916 enable type-printer [name]...
917 disable type-printer [name]...
918 Enable or disable type printers.
922 ** For the Renesas Super-H architecture, the "regs" command has been removed
923 (has been deprecated in GDB 7.5), and "info all-registers" should be used
928 set print type methods (on|off)
929 show print type methods
930 Control whether method declarations are displayed by "ptype".
931 The default is to show them.
933 set print type typedefs (on|off)
934 show print type typedefs
935 Control whether typedef definitions are displayed by "ptype".
936 The default is to show them.
938 set filename-display basename|relative|absolute
939 show filename-display
940 Control the way in which filenames is displayed.
941 The default is "relative", which preserves previous behavior.
943 set trace-buffer-size
944 show trace-buffer-size
945 Request target to change the size of trace buffer.
947 set remote trace-buffer-size-packet auto|on|off
948 show remote trace-buffer-size-packet
949 Control the use of the remote protocol `QTBuffer:size' packet.
953 Control display of debugging messages related to ARM AArch64.
956 set debug coff-pe-read
957 show debug coff-pe-read
958 Control display of debugging messages related to reading of COFF/PE
963 Control display of debugging messages related to Mach-O symbols
966 set debug notification
967 show debug notification
968 Control display of debugging info for async remote notification.
972 ** Command parameter changes are now notified using new async record
973 "=cmd-param-changed".
974 ** Trace frame changes caused by command "tfind" are now notified using
975 new async record "=traceframe-changed".
976 ** The creation, deletion and modification of trace state variables
977 are now notified using new async records "=tsv-created",
978 "=tsv-deleted" and "=tsv-modified".
979 ** The start and stop of process record are now notified using new
980 async record "=record-started" and "=record-stopped".
981 ** Memory changes are now notified using new async record
983 ** The data-disassemble command response will include a "fullname" field
984 containing the absolute file name when source has been requested.
985 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
986 command, to allow pattern filling of memory areas.
987 ** New commands "-catch-load"/"-catch-unload" added for intercepting
988 library load/unload events.
989 ** The response to breakpoint commands and breakpoint async records
990 includes an "installed" field containing a boolean state about each
991 non-pending tracepoint location is whether installed on target or not.
992 ** Output of the "-trace-status" command includes a "trace-file" field
993 containing the name of the trace file being examined. This field is
994 optional, and only present when examining a trace file.
995 ** The "fullname" field is now always present along with the "file" field,
996 even if the file cannot be found by GDB.
998 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
999 You must have the LZMA library available when configuring GDB for this
1000 feature to be enabled. For more information, see:
1001 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1003 * New remote packets
1006 Set the size of trace buffer. The remote stub reports support for this
1007 packet to gdb's qSupported query.
1010 Enable Branch Trace Store (BTS)-based branch tracing for the current
1011 thread. The remote stub reports support for this packet to gdb's
1015 Disable branch tracing for the current thread. The remote stub reports
1016 support for this packet to gdb's qSupported query.
1019 Read the traced branches for the current thread. The remote stub
1020 reports support for this packet to gdb's qSupported query.
1022 *** Changes in GDB 7.5
1024 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1025 for more x32 ABI info.
1027 * GDB now supports access to MIPS DSP registers on Linux targets.
1029 * GDB now supports debugging microMIPS binaries.
1031 * The "info os" command on GNU/Linux can now display information on
1032 several new classes of objects managed by the operating system:
1033 "info os procgroups" lists process groups
1034 "info os files" lists file descriptors
1035 "info os sockets" lists internet-domain sockets
1036 "info os shm" lists shared-memory regions
1037 "info os semaphores" lists semaphores
1038 "info os msg" lists message queues
1039 "info os modules" lists loaded kernel modules
1041 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1042 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1043 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1044 options and inspect the probe arguments using the new $_probe_arg family
1045 of convenience variables. You can obtain more information about SystemTap
1046 in <http://sourceware.org/systemtap/>.
1048 * GDB now supports reversible debugging on ARM, it allows you to
1049 debug basic ARM and THUMB instructions, and provides
1050 record/replay support.
1052 * The option "symbol-reloading" has been deleted as it is no longer used.
1056 ** GDB commands implemented in Python can now be put in command class
1059 ** The "maint set python print-stack on|off" is now deleted.
1061 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1062 apply "flag enum"-style pretty-printing to any enum.
1064 ** gdb.lookup_symbol can now work when there is no current frame.
1066 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1067 the source at which the symbol was defined.
1069 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1070 method 'value'. The former indicates whether the symbol needs a
1071 frame in order to compute its value, and the latter computes the
1074 ** A new method 'referenced_value' on gdb.Value objects which can
1075 dereference pointer as well as C++ reference values.
1077 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1078 which return the global and static blocks (as gdb.Block objects),
1079 of the underlying symbol table, respectively.
1081 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1082 object associated with a PC value.
1084 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1085 of the address range occupied by code for the current source line.
1087 * Go language support.
1088 GDB now supports debugging programs written in the Go programming
1091 * GDBserver now supports stdio connections.
1092 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1094 * The binary "gdbtui" can no longer be built or installed.
1095 Use "gdb -tui" instead.
1097 * GDB will now print "flag" enums specially. A flag enum is one where
1098 all the enumerator values have no bits in common when pairwise
1099 "and"ed. When printing a value whose type is a flag enum, GDB will
1100 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1101 (gdb) print (enum E) 3
1104 * The filename part of a linespec will now match trailing components
1105 of a source file name. For example, "break gcc/expr.c:1000" will
1106 now set a breakpoint in build/gcc/expr.c, but not
1107 build/libcpp/expr.c.
1109 * The "info proc" and "generate-core-file" commands will now also
1110 work on remote targets connected to GDBserver on Linux.
1112 * The command "info catch" has been removed. It has been disabled
1113 since December 2007.
1115 * The "catch exception" and "catch assert" commands now accept
1116 a condition at the end of the command, much like the "break"
1117 command does. For instance:
1119 (gdb) catch exception Constraint_Error if Barrier = True
1121 Previously, it was possible to add a condition to such catchpoints,
1122 but it had to be done as a second step, after the catchpoint had been
1123 created, using the "condition" command.
1125 * The "info static-tracepoint-marker" command will now also work on
1126 native Linux targets with in-process agent.
1128 * GDB can now set breakpoints on inlined functions.
1130 * The .gdb_index section has been updated to include symbols for
1131 inlined functions. GDB will ignore older .gdb_index sections by
1132 default, which could cause symbol files to be loaded more slowly
1133 until their .gdb_index sections can be recreated. The new command
1134 "set use-deprecated-index-sections on" will cause GDB to use any older
1135 .gdb_index sections it finds. This will restore performance, but the
1136 ability to set breakpoints on inlined functions will be lost in symbol
1137 files with older .gdb_index sections.
1139 The .gdb_index section has also been updated to record more information
1140 about each symbol. This speeds up the "info variables", "info functions"
1141 and "info types" commands when used with programs having the .gdb_index
1142 section, as well as speeding up debugging with shared libraries using
1143 the .gdb_index section.
1145 * Ada support for GDB/MI Variable Objects has been added.
1147 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1152 ** New command -info-os is the MI equivalent of "info os".
1154 ** Output logs ("set logging" and related) now include MI output.
1158 ** "set use-deprecated-index-sections on|off"
1159 "show use-deprecated-index-sections on|off"
1160 Controls the use of deprecated .gdb_index sections.
1162 ** "catch load" and "catch unload" can be used to stop when a shared
1163 library is loaded or unloaded, respectively.
1165 ** "enable count" can be used to auto-disable a breakpoint after
1168 ** "info vtbl" can be used to show the virtual method tables for
1169 C++ and Java objects.
1171 ** "explore" and its sub commands "explore value" and "explore type"
1172 can be used to recursively explore values and types of
1173 expressions. These commands are available only if GDB is
1174 configured with '--with-python'.
1176 ** "info auto-load" shows status of all kinds of auto-loaded files,
1177 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1178 sequences of commands files, "info auto-load python-scripts"
1179 shows status of auto-loading Python script files,
1180 "info auto-load local-gdbinit" shows status of loading init file
1181 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1182 status of inferior specific thread debugging shared library loading.
1184 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1185 and "show auto-load-scripts" commands have been deprecated, use their
1186 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1187 and "show auto-load python-scripts" counterparts instead.
1189 ** "dprintf location,format,args..." creates a dynamic printf, which
1190 is basically a breakpoint that does a printf and immediately
1191 resumes your program's execution, so it is like a printf that you
1192 can insert dynamically at runtime instead of at compiletime.
1194 ** "set print symbol"
1196 Controls whether GDB attempts to display the symbol, if any,
1197 corresponding to addresses it prints. This defaults to "on", but
1198 you can set it to "off" to restore GDB's previous behavior.
1200 * Deprecated commands
1202 ** For the Renesas Super-H architecture, the "regs" command has been
1203 deprecated, and "info all-registers" should be used instead.
1207 Renesas RL78 rl78-*-elf
1208 HP OpenVMS ia64 ia64-hp-openvms*
1210 * GDBserver supports evaluation of breakpoint conditions. When
1211 support is advertised by GDBserver, GDB may be told to send the
1212 breakpoint conditions in bytecode form to GDBserver. GDBserver
1213 will only report the breakpoint trigger to GDB when its condition
1218 set mips compression
1219 show mips compression
1220 Select the compressed ISA encoding used in functions that have no symbol
1221 information available. The encoding can be set to either of:
1224 and is updated automatically from ELF file flags if available.
1226 set breakpoint condition-evaluation
1227 show breakpoint condition-evaluation
1228 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1229 GDBserver ("target"). Default option "auto" chooses the most efficient
1231 This option can improve debugger efficiency depending on the speed of the
1235 Disable auto-loading globally.
1238 Show auto-loading setting of all kinds of auto-loaded files.
1240 set auto-load gdb-scripts on|off
1241 show auto-load gdb-scripts
1242 Control auto-loading of GDB canned sequences of commands files.
1244 set auto-load python-scripts on|off
1245 show auto-load python-scripts
1246 Control auto-loading of Python script files.
1248 set auto-load local-gdbinit on|off
1249 show auto-load local-gdbinit
1250 Control loading of init file (.gdbinit) from current directory.
1252 set auto-load libthread-db on|off
1253 show auto-load libthread-db
1254 Control auto-loading of inferior specific thread debugging shared library.
1256 set auto-load scripts-directory <dir1>[:<dir2>...]
1257 show auto-load scripts-directory
1258 Set a list of directories from which to load auto-loaded scripts.
1259 Automatically loaded Python scripts and GDB scripts are located in one
1260 of the directories listed by this option.
1261 The delimiter (':' above) may differ according to the host platform.
1263 set auto-load safe-path <dir1>[:<dir2>...]
1264 show auto-load safe-path
1265 Set a list of directories from which it is safe to auto-load files.
1266 The delimiter (':' above) may differ according to the host platform.
1268 set debug auto-load on|off
1269 show debug auto-load
1270 Control display of debugging info for auto-loading the files above.
1272 set dprintf-style gdb|call|agent
1274 Control the way in which a dynamic printf is performed; "gdb"
1275 requests a GDB printf command, while "call" causes dprintf to call a
1276 function in the inferior. "agent" requests that the target agent
1277 (such as GDBserver) do the printing.
1279 set dprintf-function <expr>
1280 show dprintf-function
1281 set dprintf-channel <expr>
1282 show dprintf-channel
1283 Set the function and optional first argument to the call when using
1284 the "call" style of dynamic printf.
1286 set disconnected-dprintf on|off
1287 show disconnected-dprintf
1288 Control whether agent-style dynamic printfs continue to be in effect
1289 after GDB disconnects.
1291 * New configure options
1293 --with-auto-load-dir
1294 Configure default value for the 'set auto-load scripts-directory'
1295 setting above. It defaults to '$debugdir:$datadir/auto-load',
1296 $debugdir representing global debugging info directories (available
1297 via 'show debug-file-directory') and $datadir representing GDB's data
1298 directory (available via 'show data-directory').
1300 --with-auto-load-safe-path
1301 Configure default value for the 'set auto-load safe-path' setting
1302 above. It defaults to the --with-auto-load-dir setting.
1304 --without-auto-load-safe-path
1305 Set 'set auto-load safe-path' to '/', effectively disabling this
1308 * New remote packets
1310 z0/z1 conditional breakpoints extension
1312 The z0/z1 breakpoint insertion packets have been extended to carry
1313 a list of conditional expressions over to the remote stub depending on the
1314 condition evaluation mode. The use of this extension can be controlled
1315 via the "set remote conditional-breakpoints-packet" command.
1319 Specify the signals which the remote stub may pass to the debugged
1320 program without GDB involvement.
1322 * New command line options
1324 --init-command=FILE, -ix Like --command, -x but execute it
1325 before loading inferior.
1326 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1327 execute it before loading inferior.
1329 *** Changes in GDB 7.4
1331 * GDB now handles ambiguous linespecs more consistently; the existing
1332 FILE:LINE support has been expanded to other types of linespecs. A
1333 breakpoint will now be set on all matching locations in all
1334 inferiors, and locations will be added or removed according to
1337 * GDB now allows you to skip uninteresting functions and files when
1338 stepping with the "skip function" and "skip file" commands.
1340 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1341 and "show remote hardware-watchpoint-length-limit". These allows to
1342 set or show the maximum length limit (in bytes) of a remote
1343 target hardware watchpoint.
1345 This allows e.g. to use "unlimited" hardware watchpoints with the
1346 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1347 watchpoints are slower than real hardware watchpoints but are
1348 significantly faster than gdb software watchpoints.
1352 ** The register_pretty_printer function in module gdb.printing now takes
1353 an optional `replace' argument. If True, the new printer replaces any
1356 ** The "maint set python print-stack on|off" command has been
1357 deprecated and will be deleted in GDB 7.5.
1358 A new command: "set python print-stack none|full|message" has
1359 replaced it. Additionally, the default for "print-stack" is
1360 now "message", which just prints the error message without
1363 ** A prompt substitution hook (prompt_hook) is now available to the
1366 ** A new Python module, gdb.prompt has been added to the GDB Python
1367 modules library. This module provides functionality for
1368 escape sequences in prompts (used by set/show
1369 extended-prompt). These escape sequences are replaced by their
1370 corresponding value.
1372 ** Python commands and convenience-functions located in
1373 'data-directory'/python/gdb/command and
1374 'data-directory'/python/gdb/function are now automatically loaded
1377 ** Blocks now provide four new attributes. global_block and
1378 static_block will return the global and static blocks
1379 respectively. is_static and is_global are boolean attributes
1380 that indicate if the block is one of those two types.
1382 ** Symbols now provide the "type" attribute, the type of the symbol.
1384 ** The "gdb.breakpoint" function has been deprecated in favor of
1387 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1388 of a function. This class is based on the "finish" command
1389 available in the CLI.
1391 ** Type objects for struct and union types now allow access to
1392 the fields using standard Python dictionary (mapping) methods.
1393 For example, "some_type['myfield']" now works, as does
1394 "some_type.items()".
1396 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1399 ** A new function, "deep_items" has been added to the gdb.types
1400 module in the GDB Python modules library. This function returns
1401 an iterator over the fields of a struct or union type. Unlike
1402 the standard Python "iteritems" method, it will recursively traverse
1403 any anonymous fields.
1407 ** "*stopped" events can report several new "reason"s, such as
1410 ** Breakpoint changes are now notified using new async records, like
1411 "=breakpoint-modified".
1413 ** New command -ada-task-info.
1415 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1416 $sdir specifies the default system locations of shared libraries.
1417 $pdir specifies the directory where the libpthread used by the application
1420 GDB no longer looks in $sdir and $pdir after it has searched the directories
1421 mentioned in libthread-db-search-path. If you want to search those
1422 directories, they must be specified in libthread-db-search-path.
1423 The default value of libthread-db-search-path on GNU/Linux and Solaris
1424 systems is now "$sdir:$pdir".
1426 $pdir is not supported by gdbserver, it is currently ignored.
1427 $sdir is supported by gdbserver.
1429 * New configure option --with-iconv-bin.
1430 When using the internationalization support like the one in the GNU C
1431 library, GDB will invoke the "iconv" program to get a list of supported
1432 character sets. If this program lives in a non-standard location, one can
1433 use this option to specify where to find it.
1435 * When natively debugging programs on PowerPC BookE processors running
1436 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1437 watchpoints, which specify a mask in addition to an address to watch.
1438 The mask specifies that some bits of an address (the bits which are
1439 reset in the mask) should be ignored when matching the address accessed
1440 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1441 section in the user manual for more details.
1443 * The new option --once causes GDBserver to stop listening for connections once
1444 the first connection is made. The listening port used by GDBserver will
1445 become available after that.
1447 * New commands "info macros" and "alias" have been added.
1449 * New function parameters suffix @entry specifies value of function parameter
1450 at the time the function got called. Entry values are available only since
1456 "!" is now an alias of the "shell" command.
1457 Note that no space is needed between "!" and SHELL COMMAND.
1461 watch EXPRESSION mask MASK_VALUE
1462 The watch command now supports the mask argument which allows creation
1463 of masked watchpoints, if the current architecture supports this feature.
1465 info auto-load-scripts [REGEXP]
1466 This command was formerly named "maintenance print section-scripts".
1467 It is now generally useful and is no longer a maintenance-only command.
1469 info macro [-all] [--] MACRO
1470 The info macro command has new options `-all' and `--'. The first for
1471 printing all definitions of a macro. The second for explicitly specifying
1472 the end of arguments and the beginning of the macro name in case the macro
1473 name starts with a hyphen.
1475 collect[/s] EXPRESSIONS
1476 The tracepoint collect command now takes an optional modifier "/s"
1477 that directs it to dereference pointer-to-character types and
1478 collect the bytes of memory up to a zero byte. The behavior is
1479 similar to what you see when you use the regular print command on a
1480 string. An optional integer following the "/s" sets a bound on the
1481 number of bytes that will be collected.
1484 The trace start command now interprets any supplied arguments as a
1485 note to be recorded with the trace run, with an effect similar to
1486 setting the variable trace-notes.
1489 The trace stop command now interprets any arguments as a note to be
1490 mentioned along with the tstatus report that the trace was stopped
1491 with a command. The effect is similar to setting the variable
1494 * Tracepoints can now be enabled and disabled at any time after a trace
1495 experiment has been started using the standard "enable" and "disable"
1496 commands. It is now possible to start a trace experiment with no enabled
1497 tracepoints; GDB will display a warning, but will allow the experiment to
1498 begin, assuming that tracepoints will be enabled as needed while the trace
1501 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1502 locations with 4-byte instructions, when they were previously
1503 limited to locations with instructions of 5 bytes or longer.
1507 set debug dwarf2-read
1508 show debug dwarf2-read
1509 Turns on or off display of debugging messages related to reading
1510 DWARF debug info. The default is off.
1512 set debug symtab-create
1513 show debug symtab-create
1514 Turns on or off display of debugging messages related to symbol table
1515 creation. The default is off.
1518 show extended-prompt
1519 Set the GDB prompt, and allow escape sequences to be inserted to
1520 display miscellaneous information (see 'help set extended-prompt'
1521 for the list of sequences). This prompt (and any information
1522 accessed through the escape sequences) is updated every time the
1523 prompt is displayed.
1525 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1526 show print entry-values
1527 Set printing of frame argument values at function entry. In some cases
1528 GDB can determine the value of function argument which was passed by the
1529 function caller, even if the value was modified inside the called function.
1531 set debug entry-values
1532 show debug entry-values
1533 Control display of debugging info for determining frame argument values at
1534 function entry and virtual tail call frames.
1536 set basenames-may-differ
1537 show basenames-may-differ
1538 Set whether a source file may have multiple base names.
1539 (A "base name" is the name of a file with the directory part removed.
1540 Example: The base name of "/home/user/hello.c" is "hello.c".)
1541 If set, GDB will canonicalize file names (e.g., expand symlinks)
1542 before comparing them. Canonicalization is an expensive operation,
1543 but it allows the same file be known by more than one base name.
1544 If not set (the default), all source files are assumed to have just
1545 one base name, and gdb will do file name comparisons more efficiently.
1551 Set a user name and notes for the current and any future trace runs.
1552 This is useful for long-running and/or disconnected traces, to
1553 inform others (or yourself) as to who is running the trace, supply
1554 contact information, or otherwise explain what is going on.
1556 set trace-stop-notes
1557 show trace-stop-notes
1558 Set a note attached to the trace run, that is displayed when the
1559 trace has been stopped by a tstop command. This is useful for
1560 instance as an explanation, if you are stopping a trace run that was
1561 started by someone else.
1563 * New remote packets
1567 Dynamically enable a tracepoint in a started trace experiment.
1571 Dynamically disable a tracepoint in a started trace experiment.
1575 Set the user and notes of the trace run.
1579 Query the current status of a tracepoint.
1583 Query the minimum length of instruction at which a fast tracepoint may
1586 * Dcache size (number of lines) and line-size are now runtime-configurable
1587 via "set dcache line" and "set dcache line-size" commands.
1591 Texas Instruments TMS320C6x tic6x-*-*
1595 Renesas RL78 rl78-*-elf
1597 *** Changes in GDB 7.3.1
1599 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1601 *** Changes in GDB 7.3
1603 * GDB has a new command: "thread find [REGEXP]".
1604 It finds the thread id whose name, target id, or thread extra info
1605 matches the given regular expression.
1607 * The "catch syscall" command now works on mips*-linux* targets.
1609 * The -data-disassemble MI command now supports modes 2 and 3 for
1610 dumping the instruction opcodes.
1612 * New command line options
1614 -data-directory DIR Specify DIR as the "data-directory".
1615 This is mostly for testing purposes.
1617 * The "maint set python auto-load on|off" command has been renamed to
1618 "set auto-load-scripts on|off".
1620 * GDB has a new command: "set directories".
1621 It is like the "dir" command except that it replaces the
1622 source path list instead of augmenting it.
1624 * GDB now understands thread names.
1626 On GNU/Linux, "info threads" will display the thread name as set by
1627 prctl or pthread_setname_np.
1629 There is also a new command, "thread name", which can be used to
1630 assign a name internally for GDB to display.
1633 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1634 has been integrated into GDB.
1638 ** The function gdb.Write now accepts an optional keyword 'stream'.
1639 This keyword, when provided, will direct the output to either
1640 stdout, stderr, or GDB's logging output.
1642 ** Parameters can now be be sub-classed in Python, and in particular
1643 you may implement the get_set_doc and get_show_doc functions.
1644 This improves how Parameter set/show documentation is processed
1645 and allows for more dynamic content.
1647 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1648 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1649 have an is_valid method.
1651 ** Breakpoints can now be sub-classed in Python, and in particular
1652 you may implement a 'stop' function that is executed each time
1653 the inferior reaches that breakpoint.
1655 ** New function gdb.lookup_global_symbol looks up a global symbol.
1657 ** GDB values in Python are now callable if the value represents a
1658 function. For example, if 'some_value' represents a function that
1659 takes two integer parameters and returns a value, you can call
1660 that function like so:
1662 result = some_value (10,20)
1664 ** Module gdb.types has been added.
1665 It contains a collection of utilities for working with gdb.Types objects:
1666 get_basic_type, has_field, make_enum_dict.
1668 ** Module gdb.printing has been added.
1669 It contains utilities for writing and registering pretty-printers.
1670 New classes: PrettyPrinter, SubPrettyPrinter,
1671 RegexpCollectionPrettyPrinter.
1672 New function: register_pretty_printer.
1674 ** New commands "info pretty-printers", "enable pretty-printer" and
1675 "disable pretty-printer" have been added.
1677 ** gdb.parameter("directories") is now available.
1679 ** New function gdb.newest_frame returns the newest frame in the
1682 ** The gdb.InferiorThread class has a new "name" attribute. This
1683 holds the thread's name.
1685 ** Python Support for Inferior events.
1686 Python scripts can add observers to be notified of events
1687 occurring in the process being debugged.
1688 The following events are currently supported:
1689 - gdb.events.cont Continue event.
1690 - gdb.events.exited Inferior exited event.
1691 - gdb.events.stop Signal received, and Breakpoint hit events.
1695 ** GDB now puts template parameters in scope when debugging in an
1696 instantiation. For example, if you have:
1698 template<int X> int func (void) { return X; }
1700 then if you step into func<5>, "print X" will show "5". This
1701 feature requires proper debuginfo support from the compiler; it
1702 was added to GCC 4.5.
1704 ** The motion commands "next", "finish", "until", and "advance" now
1705 work better when exceptions are thrown. In particular, GDB will
1706 no longer lose control of the inferior; instead, the GDB will
1707 stop the inferior at the point at which the exception is caught.
1708 This functionality requires a change in the exception handling
1709 code that was introduced in GCC 4.5.
1711 * GDB now follows GCC's rules on accessing volatile objects when
1712 reading or writing target state during expression evaluation.
1713 One notable difference to prior behavior is that "print x = 0"
1714 no longer generates a read of x; the value of the assignment is
1715 now always taken directly from the value being assigned.
1717 * GDB now has some support for using labels in the program's source in
1718 linespecs. For instance, you can use "advance label" to continue
1719 execution to a label.
1721 * GDB now has support for reading and writing a new .gdb_index
1722 section. This section holds a fast index of DWARF debugging
1723 information and can be used to greatly speed up GDB startup and
1724 operation. See the documentation for `save gdb-index' for details.
1726 * The "watch" command now accepts an optional "-location" argument.
1727 When used, this causes GDB to watch the memory referred to by the
1728 expression. Such a watchpoint is never deleted due to it going out
1731 * GDB now supports thread debugging of core dumps on GNU/Linux.
1733 GDB now activates thread debugging using the libthread_db library
1734 when debugging GNU/Linux core dumps, similarly to when debugging
1735 live processes. As a result, when debugging a core dump file, GDB
1736 is now able to display pthread_t ids of threads. For example, "info
1737 threads" shows the same output as when debugging the process when it
1738 was live. In earlier releases, you'd see something like this:
1741 * 1 LWP 6780 main () at main.c:10
1743 While now you see this:
1746 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1748 It is also now possible to inspect TLS variables when debugging core
1751 When debugging a core dump generated on a machine other than the one
1752 used to run GDB, you may need to point GDB at the correct
1753 libthread_db library with the "set libthread-db-search-path"
1754 command. See the user manual for more details on this command.
1756 * When natively debugging programs on PowerPC BookE processors running
1757 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1758 which stop execution of the inferior whenever it executes an instruction
1759 at any address within the specified range. See the "PowerPC Embedded"
1760 section in the user manual for more details.
1762 * New features in the GDB remote stub, GDBserver
1764 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1765 and i686 LynxOS (version 5.x).
1767 ** GDBserver is now supported on Blackfin Linux.
1769 * New native configurations
1771 ia64 HP-UX ia64-*-hpux*
1775 Analog Devices, Inc. Blackfin Processor bfin-*
1777 * Ada task switching is now supported on sparc-elf targets when
1778 debugging a program using the Ravenscar Profile. For more information,
1779 see the "Tasking Support when using the Ravenscar Profile" section
1780 in the GDB user manual.
1782 * Guile support was removed.
1784 * New features in the GNU simulator
1786 ** The --map-info flag lists all known core mappings.
1788 ** CFI flashes may be simulated via the "cfi" device.
1790 *** Changes in GDB 7.2
1792 * Shared library support for remote targets by default
1794 When GDB is configured for a generic, non-OS specific target, like
1795 for example, --target=arm-eabi or one of the many *-*-elf targets,
1796 GDB now queries remote stubs for loaded shared libraries using the
1797 `qXfer:libraries:read' packet. Previously, shared library support
1798 was always disabled for such configurations.
1802 ** Argument Dependent Lookup (ADL)
1804 In C++ ADL lookup directs function search to the namespaces of its
1805 arguments even if the namespace has not been imported.
1815 Here the compiler will search for `foo' in the namespace of 'b'
1816 and find A::foo. GDB now supports this. This construct is commonly
1817 used in the Standard Template Library for operators.
1819 ** Improved User Defined Operator Support
1821 In addition to member operators, GDB now supports lookup of operators
1822 defined in a namespace and imported with a `using' directive, operators
1823 defined in the global scope, operators imported implicitly from an
1824 anonymous namespace, and the ADL operators mentioned in the previous
1826 GDB now also supports proper overload resolution for all the previously
1827 mentioned flavors of operators.
1829 ** static const class members
1831 Printing of static const class members that are initialized in the
1832 class definition has been fixed.
1834 * Windows Thread Information Block access.
1836 On Windows targets, GDB now supports displaying the Windows Thread
1837 Information Block (TIB) structure. This structure is visible either
1838 by using the new command `info w32 thread-information-block' or, by
1839 dereferencing the new convenience variable named `$_tlb', a
1840 thread-specific pointer to the TIB. This feature is also supported
1841 when remote debugging using GDBserver.
1843 * Static tracepoints
1845 Static tracepoints are calls in the user program into a tracing
1846 library. One such library is a port of the LTTng kernel tracer to
1847 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1848 When debugging with GDBserver, GDB now supports combining the GDB
1849 tracepoint machinery with such libraries. For example: the user can
1850 use GDB to probe a static tracepoint marker (a call from the user
1851 program into the tracing library) with the new "strace" command (see
1852 "New commands" below). This creates a "static tracepoint" in the
1853 breakpoint list, that can be manipulated with the same feature set
1854 as fast and regular tracepoints. E.g., collect registers, local and
1855 global variables, collect trace state variables, and define
1856 tracepoint conditions. In addition, the user can collect extra
1857 static tracepoint marker specific data, by collecting the new
1858 $_sdata internal variable. When analyzing the trace buffer, you can
1859 inspect $_sdata like any other variable available to GDB. For more
1860 information, see the "Tracepoints" chapter in GDB user manual. New
1861 remote packets have been defined to support static tracepoints, see
1862 the "New remote packets" section below.
1864 * Better reconstruction of tracepoints after disconnected tracing
1866 GDB will attempt to download the original source form of tracepoint
1867 definitions when starting a trace run, and then will upload these
1868 upon reconnection to the target, resulting in a more accurate
1869 reconstruction of the tracepoints that are in use on the target.
1873 You can now exercise direct control over the ways that GDB can
1874 affect your program. For instance, you can disallow the setting of
1875 breakpoints, so that the program can run continuously (assuming
1876 non-stop mode). In addition, the "observer" variable is available
1877 to switch all of the different controls; in observer mode, GDB
1878 cannot affect the target's behavior at all, which is useful for
1879 tasks like diagnosing live systems in the field.
1881 * The new convenience variable $_thread holds the number of the
1884 * New remote packets
1888 Return the address of the Windows Thread Information Block of a given thread.
1892 In response to several of the tracepoint packets, the target may now
1893 also respond with a number of intermediate `qRelocInsn' request
1894 packets before the final result packet, to have GDB handle
1895 relocating an instruction to execute at a different address. This
1896 is particularly useful for stubs that support fast tracepoints. GDB
1897 reports support for this feature in the qSupported packet.
1901 List static tracepoint markers in the target program.
1905 List static tracepoint markers at a given address in the target
1908 qXfer:statictrace:read
1910 Read the static trace data collected (by a `collect $_sdata'
1911 tracepoint action). The remote stub reports support for this packet
1912 to gdb's qSupported query.
1916 Send the current settings of GDB's permission flags.
1920 Send part of the source (textual) form of a tracepoint definition,
1921 which includes location, conditional, and action list.
1923 * The source command now accepts a -s option to force searching for the
1924 script in the source search path even if the script name specifies
1927 * New features in the GDB remote stub, GDBserver
1929 - GDBserver now support tracepoints (including fast tracepoints, and
1930 static tracepoints). The feature is currently supported by the
1931 i386-linux and amd64-linux builds. See the "Tracepoints support
1932 in gdbserver" section in the manual for more information.
1934 GDBserver JIT compiles the tracepoint's conditional agent
1935 expression bytecode into native code whenever possible for low
1936 overhead dynamic tracepoints conditionals. For such tracepoints,
1937 an expression that examines program state is evaluated when the
1938 tracepoint is reached, in order to determine whether to capture
1939 trace data. If the condition is simple and false, processing the
1940 tracepoint finishes very quickly and no data is gathered.
1942 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1943 for static tracepoints support.
1945 - GDBserver now supports x86_64 Windows 64-bit debugging.
1947 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1948 it understands register description.
1950 * The --batch flag now disables pagination and queries.
1952 * X86 general purpose registers
1954 GDB now supports reading/writing byte, word and double-word x86
1955 general purpose registers directly. This means you can use, say,
1956 $ah or $ax to refer, respectively, to the byte register AH and
1957 16-bit word register AX that are actually portions of the 32-bit
1958 register EAX or 64-bit register RAX.
1960 * The `commands' command now accepts a range of breakpoints to modify.
1961 A plain `commands' following a command that creates multiple
1962 breakpoints affects all the breakpoints set by that command. This
1963 applies to breakpoints set by `rbreak', and also applies when a
1964 single `break' command creates multiple breakpoints (e.g.,
1965 breakpoints on overloaded c++ functions).
1967 * The `rbreak' command now accepts a filename specification as part of
1968 its argument, limiting the functions selected by the regex to those
1969 in the specified file.
1971 * Support for remote debugging Windows and SymbianOS shared libraries
1972 from Unix hosts has been improved. Non Windows GDB builds now can
1973 understand target reported file names that follow MS-DOS based file
1974 system semantics, such as file names that include drive letters and
1975 use the backslash character as directory separator. This makes it
1976 possible to transparently use the "set sysroot" and "set
1977 solib-search-path" on Unix hosts to point as host copies of the
1978 target's shared libraries. See the new command "set
1979 target-file-system-kind" described below, and the "Commands to
1980 specify files" section in the user manual for more information.
1984 eval template, expressions...
1985 Convert the values of one or more expressions under the control
1986 of the string template to a command line, and call it.
1988 set target-file-system-kind unix|dos-based|auto
1989 show target-file-system-kind
1990 Set or show the assumed file system kind for target reported file
1993 save breakpoints <filename>
1994 Save all current breakpoint definitions to a file suitable for use
1995 in a later debugging session. To read the saved breakpoint
1996 definitions, use the `source' command.
1998 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2001 info static-tracepoint-markers
2002 Display information about static tracepoint markers in the target.
2004 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2005 Define a static tracepoint by probing a marker at the given
2006 function, line, address, or marker ID.
2010 Enable and disable observer mode.
2012 set may-write-registers on|off
2013 set may-write-memory on|off
2014 set may-insert-breakpoints on|off
2015 set may-insert-tracepoints on|off
2016 set may-insert-fast-tracepoints on|off
2017 set may-interrupt on|off
2018 Set individual permissions for GDB effects on the target. Note that
2019 some of these settings can have undesirable or surprising
2020 consequences, particularly when changed in the middle of a session.
2021 For instance, disabling the writing of memory can prevent
2022 breakpoints from being inserted, cause single-stepping to fail, or
2023 even crash your program, if you disable after breakpoints have been
2024 inserted. However, GDB should not crash.
2026 set record memory-query on|off
2027 show record memory-query
2028 Control whether to stop the inferior if memory changes caused
2029 by an instruction cannot be recorded.
2034 The disassemble command now supports "start,+length" form of two arguments.
2038 ** GDB now provides a new directory location, called the python directory,
2039 where Python scripts written for GDB can be installed. The location
2040 of that directory is <data-directory>/python, where <data-directory>
2041 is the GDB data directory. For more details, see section `Scripting
2042 GDB using Python' in the manual.
2044 ** The GDB Python API now has access to breakpoints, symbols, symbol
2045 tables, program spaces, inferiors, threads and frame's code blocks.
2046 Additionally, GDB Parameters can now be created from the API, and
2047 manipulated via set/show in the CLI.
2049 ** New functions gdb.target_charset, gdb.target_wide_charset,
2050 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2052 ** New exception gdb.GdbError.
2054 ** Pretty-printers are now also looked up in the current program space.
2056 ** Pretty-printers can now be individually enabled and disabled.
2058 ** GDB now looks for names of Python scripts to auto-load in a
2059 special section named `.debug_gdb_scripts', in addition to looking
2060 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2062 * Tracepoint actions were unified with breakpoint commands. In particular,
2063 there are no longer differences in "info break" output for breakpoints and
2064 tracepoints and the "commands" command can be used for both tracepoints and
2065 regular breakpoints.
2069 ARM Symbian arm*-*-symbianelf*
2071 * D language support.
2072 GDB now supports debugging programs written in the D programming
2075 * GDB now supports the extended ptrace interface for PowerPC which is
2076 available since Linux kernel version 2.6.34. This automatically enables
2077 any hardware breakpoints and additional hardware watchpoints available in
2078 the processor. The old ptrace interface exposes just one hardware
2079 watchpoint and no hardware breakpoints.
2081 * GDB is now able to use the Data Value Compare (DVC) register available on
2082 embedded PowerPC processors to implement in hardware simple watchpoint
2083 conditions of the form:
2085 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2087 This works in native GDB running on Linux kernels with the extended ptrace
2088 interface mentioned above.
2090 *** Changes in GDB 7.1
2094 ** Namespace Support
2096 GDB now supports importing of namespaces in C++. This enables the
2097 user to inspect variables from imported namespaces. Support for
2098 namepace aliasing has also been added. So, if a namespace is
2099 aliased in the current scope (e.g. namepace C=A; ) the user can
2100 print variables using the alias (e.g. (gdb) print C::x).
2104 All known bugs relating to the printing of virtual base class were
2105 fixed. It is now possible to call overloaded static methods using a
2110 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2111 and reinterpret_cast<> are now handled by the C++ expression parser.
2115 Xilinx MicroBlaze microblaze-*-*
2120 Xilinx MicroBlaze microblaze
2123 * Multi-program debugging.
2125 GDB now has support for multi-program (a.k.a. multi-executable or
2126 multi-exec) debugging. This allows for debugging multiple inferiors
2127 simultaneously each running a different program under the same GDB
2128 session. See "Debugging Multiple Inferiors and Programs" in the
2129 manual for more information. This implied some user visible changes
2130 in the multi-inferior support. For example, "info inferiors" now
2131 lists inferiors that are not running yet or that have exited
2132 already. See also "New commands" and "New options" below.
2134 * New tracing features
2136 GDB's tracepoint facility now includes several new features:
2138 ** Trace state variables
2140 GDB tracepoints now include support for trace state variables, which
2141 are variables managed by the target agent during a tracing
2142 experiment. They are useful for tracepoints that trigger each
2143 other, so for instance one tracepoint can count hits in a variable,
2144 and then a second tracepoint has a condition that is true when the
2145 count reaches a particular value. Trace state variables share the
2146 $-syntax of GDB convenience variables, and can appear in both
2147 tracepoint actions and condition expressions. Use the "tvariable"
2148 command to create, and "info tvariables" to view; see "Trace State
2149 Variables" in the manual for more detail.
2153 GDB now includes an option for defining fast tracepoints, which
2154 targets may implement more efficiently, such as by installing a jump
2155 into the target agent rather than a trap instruction. The resulting
2156 speedup can be by two orders of magnitude or more, although the
2157 tradeoff is that some program locations on some target architectures
2158 might not allow fast tracepoint installation, for instance if the
2159 instruction to be replaced is shorter than the jump. To request a
2160 fast tracepoint, use the "ftrace" command, with syntax identical to
2161 the regular trace command.
2163 ** Disconnected tracing
2165 It is now possible to detach GDB from the target while it is running
2166 a trace experiment, then reconnect later to see how the experiment
2167 is going. In addition, a new variable disconnected-tracing lets you
2168 tell the target agent whether to continue running a trace if the
2169 connection is lost unexpectedly.
2173 GDB now has the ability to save the trace buffer into a file, and
2174 then use that file as a target, similarly to you can do with
2175 corefiles. You can select trace frames, print data that was
2176 collected in them, and use tstatus to display the state of the
2177 tracing run at the moment that it was saved. To create a trace
2178 file, use "tsave <filename>", and to use it, do "target tfile
2181 ** Circular trace buffer
2183 You can ask the target agent to handle the trace buffer as a
2184 circular buffer, discarding the oldest trace frames to make room for
2185 newer ones, by setting circular-trace-buffer to on. This feature may
2186 not be available for all target agents.
2191 The disassemble command, when invoked with two arguments, now requires
2192 the arguments to be comma-separated.
2195 The info variables command now displays variable definitions. Files
2196 which only declare a variable are not shown.
2199 The source command is now capable of sourcing Python scripts.
2200 This feature is dependent on the debugger being build with Python
2203 Related to this enhancement is also the introduction of a new command
2204 "set script-extension" (see below).
2206 * New commands (for set/show, see "New options" below)
2208 record save [<FILENAME>]
2209 Save a file (in core file format) containing the process record
2210 execution log for replay debugging at a later time.
2212 record restore <FILENAME>
2213 Restore the process record execution log that was saved at an
2214 earlier time, for replay debugging.
2216 add-inferior [-copies <N>] [-exec <FILENAME>]
2219 clone-inferior [-copies <N>] [ID]
2220 Make a new inferior ready to execute the same program another
2221 inferior has loaded.
2226 maint info program-spaces
2227 List the program spaces loaded into GDB.
2229 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2230 show remote interrupt-sequence
2231 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2232 as the sequence to the remote target in order to interrupt the execution.
2233 Ctrl-C is a default. Some system prefers BREAK which is high level of
2234 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2235 Magic SysRq g. It is BREAK signal and character 'g'.
2237 set remote interrupt-on-connect [on | off]
2238 show remote interrupt-on-connect
2239 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2240 remote target when gdb connects to it. This is needed when you debug
2243 set remotebreak [on | off]
2245 Deprecated. Use "set/show remote interrupt-sequence" instead.
2247 tvariable $NAME [ = EXP ]
2248 Create or modify a trace state variable.
2251 List trace state variables and their values.
2253 delete tvariable $NAME ...
2254 Delete one or more trace state variables.
2257 Evaluate the given expressions without collecting anything into the
2258 trace buffer. (Valid in tracepoint actions only.)
2260 ftrace FN / FILE:LINE / *ADDR
2261 Define a fast tracepoint at the given function, line, or address.
2263 * New expression syntax
2265 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2266 GDB now parses 0b101010 identically with 42.
2270 set follow-exec-mode new|same
2271 show follow-exec-mode
2272 Control whether GDB reuses the same inferior across an exec call or
2273 creates a new one. This is useful to be able to restart the old
2274 executable after the inferior having done an exec call.
2276 set default-collect EXPR, ...
2277 show default-collect
2278 Define a list of expressions to be collected at each tracepoint.
2279 This is a useful way to ensure essential items are not overlooked,
2280 such as registers or a critical global variable.
2282 set disconnected-tracing
2283 show disconnected-tracing
2284 If set to 1, the target is instructed to continue tracing if it
2285 loses its connection to GDB. If 0, the target is to stop tracing
2288 set circular-trace-buffer
2289 show circular-trace-buffer
2290 If set to on, the target is instructed to use a circular trace buffer
2291 and discard the oldest trace frames instead of stopping the trace due
2292 to a full trace buffer. If set to off, the trace stops when the buffer
2293 fills up. Some targets may not support this.
2295 set script-extension off|soft|strict
2296 show script-extension
2297 If set to "off", the debugger does not perform any script language
2298 recognition, and all sourced files are assumed to be GDB scripts.
2299 If set to "soft" (the default), files are sourced according to
2300 filename extension, falling back to GDB scripts if the first
2302 If set to "strict", files are sourced according to filename extension.
2304 set ada trust-PAD-over-XVS on|off
2305 show ada trust-PAD-over-XVS
2306 If off, activate a workaround against a bug in the debugging information
2307 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2308 the GCC sources for more information about the GNAT encoding and
2309 PAD types in particular). It is always safe to set this option to
2310 off, but this introduces a slight performance penalty. The default
2313 * Python API Improvements
2315 ** GDB provides the new class gdb.LazyString. This is useful in
2316 some pretty-printing cases. The new method gdb.Value.lazy_string
2317 provides a simple way to create objects of this type.
2319 ** The fields returned by gdb.Type.fields now have an
2320 `is_base_class' attribute.
2322 ** The new method gdb.Type.range returns the range of an array type.
2324 ** The new method gdb.parse_and_eval can be used to parse and
2325 evaluate an expression.
2327 * New remote packets
2330 Define a trace state variable.
2333 Get the current value of a trace state variable.
2336 Set desired tracing behavior upon disconnection.
2339 Set the trace buffer to be linear or circular.
2342 Get data about the tracepoints currently in use.
2346 Process record now works correctly with hardware watchpoints.
2348 Multiple bug fixes have been made to the mips-irix port, making it
2349 much more reliable. In particular:
2350 - Debugging threaded applications is now possible again. Previously,
2351 GDB would hang while starting the program, or while waiting for
2352 the program to stop at a breakpoint.
2353 - Attaching to a running process no longer hangs.
2354 - An error occurring while loading a core file has been fixed.
2355 - Changing the value of the PC register now works again. This fixes
2356 problems observed when using the "jump" command, or when calling
2357 a function from GDB, or even when assigning a new value to $pc.
2358 - With the "finish" and "return" commands, the return value for functions
2359 returning a small array is now correctly printed.
2360 - It is now possible to break on shared library code which gets executed
2361 during a shared library init phase (code executed while executing
2362 their .init section). Previously, the breakpoint would have no effect.
2363 - GDB is now able to backtrace through the signal handler for
2364 non-threaded programs.
2366 PIE (Position Independent Executable) programs debugging is now supported.
2367 This includes debugging execution of PIC (Position Independent Code) shared
2368 libraries although for that, it should be possible to run such libraries as an
2371 *** Changes in GDB 7.0
2373 * GDB now has an interface for JIT compilation. Applications that
2374 dynamically generate code can create symbol files in memory and register
2375 them with GDB. For users, the feature should work transparently, and
2376 for JIT developers, the interface is documented in the GDB manual in the
2377 "JIT Compilation Interface" chapter.
2379 * Tracepoints may now be conditional. The syntax is as for
2380 breakpoints; either an "if" clause appended to the "trace" command,
2381 or the "condition" command is available. GDB sends the condition to
2382 the target for evaluation using the same bytecode format as is used
2383 for tracepoint actions.
2385 * The disassemble command now supports: an optional /r modifier, print the
2386 raw instructions in hex as well as in symbolic form, and an optional /m
2387 modifier to print mixed source+assembly.
2389 * Process record and replay
2391 In a architecture environment that supports ``process record and
2392 replay'', ``process record and replay'' target can record a log of
2393 the process execution, and replay it with both forward and reverse
2396 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2397 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2398 set execution-direction {forward|reverse}, for targets that support
2401 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2402 feature is available with a native GDB running on kernel version
2405 * GDB now has support for multi-byte and wide character sets on the
2406 target. Strings whose character type is wchar_t, char16_t, or
2407 char32_t are now correctly printed. GDB supports wide- and unicode-
2408 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2409 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2410 `printf'. This feature requires iconv to work properly; if your
2411 system does not have a working iconv, GDB can use GNU libiconv. See
2412 the installation instructions for more information.
2414 * GDB now supports automatic retrieval of shared library files from
2415 remote targets. To use this feature, specify a system root that begins
2416 with the `remote:' prefix, either via the `set sysroot' command or via
2417 the `--with-sysroot' configure-time option.
2419 * "info sharedlibrary" now takes an optional regex of libraries to show,
2420 and it now reports if a shared library has no debugging information.
2422 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2423 now complete on file names.
2425 * When completing in expressions, gdb will attempt to limit
2426 completions to allowable structure or union fields, where appropriate.
2427 For instance, consider:
2429 # struct example { int f1; double f2; };
2430 # struct example variable;
2433 If the user types TAB at the end of this command line, the available
2434 completions will be "f1" and "f2".
2436 * Inlined functions are now supported. They show up in backtraces, and
2437 the "step", "next", and "finish" commands handle them automatically.
2439 * GDB now supports the token-splicing (##) and stringification (#)
2440 operators when expanding macros. It also supports variable-arity
2443 * GDB now supports inspecting extra signal information, exported by
2444 the new $_siginfo convenience variable. The feature is currently
2445 implemented on linux ARM, i386 and amd64.
2447 * GDB can now display the VFP floating point registers and NEON vector
2448 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2449 can provide these registers (requires Linux 2.6.30 or later). Remote
2450 and simulator targets may also provide them.
2452 * New remote packets
2455 Search memory for a sequence of bytes.
2458 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2459 operation over reliable transport links. Use of this packet is
2460 controlled by the `set remote noack-packet' command.
2463 Kill the process with the specified process ID. Use this in preference
2464 to `k' when multiprocess protocol extensions are supported.
2467 Obtains additional operating system information
2471 Read or write additional signal information.
2473 * Removed remote protocol undocumented extension
2475 An undocumented extension to the remote protocol's `S' stop reply
2476 packet that permited the stub to pass a process id was removed.
2477 Remote servers should use the `T' stop reply packet instead.
2479 * GDB now supports multiple function calling conventions according to the
2480 DWARF-2 DW_AT_calling_convention function attribute.
2482 * The SH target utilizes the aforementioned change to distinguish between gcc
2483 and Renesas calling convention. It also adds the new CLI commands
2484 `set/show sh calling-convention'.
2486 * GDB can now read compressed debug sections, as produced by GNU gold
2487 with the --compress-debug-sections=zlib flag.
2489 * 64-bit core files are now supported on AIX.
2491 * Thread switching is now supported on Tru64.
2493 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2494 which will be allocated using malloc later in program execution.
2496 * The qXfer:libraries:read remote procotol packet now allows passing a
2497 list of section offsets.
2499 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2500 conditions handling signals delivered during attach or thread creation
2501 have also been fixed.
2503 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2504 From the user's standpoint, all unqualified instances of True and False
2505 are treated as the standard definitions, regardless of context.
2507 * GDB now parses C++ symbol and type names more flexibly. For
2510 template<typename T> class C { };
2513 GDB will now correctly handle all of:
2515 ptype C<char const *>
2516 ptype C<char const*>
2517 ptype C<const char *>
2518 ptype C<const char*>
2520 * New features in the GDB remote stub, gdbserver
2522 - The "--wrapper" command-line argument tells gdbserver to use a
2523 wrapper program to launch programs for debugging.
2525 - On PowerPC and S/390 targets, it is now possible to use a single
2526 gdbserver executable to debug both 32-bit and 64-bit programs.
2527 (This requires gdbserver itself to be built as a 64-bit executable.)
2529 - gdbserver uses the new noack protocol mode for TCP connections to
2530 reduce communications latency, if also supported and enabled in GDB.
2532 - Support for the sparc64-linux-gnu target is now included in
2535 - The amd64-linux build of gdbserver now supports debugging both
2536 32-bit and 64-bit programs.
2538 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2539 now support hardware watchpoints, and will use them automatically
2544 GDB now has support for scripting using Python. Whether this is
2545 available is determined at configure time.
2547 New GDB commands can now be written in Python.
2549 * Ada tasking support
2551 Ada tasks can now be inspected in GDB. The following commands have
2555 Print the list of Ada tasks.
2557 Print detailed information about task number N.
2559 Print the task number of the current task.
2561 Switch the context of debugging to task number N.
2563 * Support for user-defined prefixed commands. The "define" command can
2564 add new commands to existing prefixes, e.g. "target".
2566 * Multi-inferior, multi-process debugging.
2568 GDB now has generalized support for multi-inferior debugging. See
2569 "Debugging Multiple Inferiors" in the manual for more information.
2570 Although availability still depends on target support, the command
2571 set is more uniform now. The GNU/Linux specific multi-forks support
2572 has been migrated to this new framework. This implied some user
2573 visible changes; see "New commands" and also "Removed commands"
2576 * Target descriptions can now describe the target OS ABI. See the
2577 "Target Description Format" section in the user manual for more
2580 * Target descriptions can now describe "compatible" architectures
2581 to indicate that the target can execute applications for a different
2582 architecture in addition to those for the main target architecture.
2583 See the "Target Description Format" section in the user manual for
2586 * Multi-architecture debugging.
2588 GDB now includes general supports for debugging applications on
2589 hybrid systems that use more than one single processor architecture
2590 at the same time. Each such hybrid architecture still requires
2591 specific support to be added. The only hybrid architecture supported
2592 in this version of GDB is the Cell Broadband Engine.
2594 * GDB now supports integrated debugging of Cell/B.E. applications that
2595 use both the PPU and SPU architectures. To enable support for hybrid
2596 Cell/B.E. debugging, you need to configure GDB to support both the
2597 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2598 --enable-targets configure option.
2600 * Non-stop mode debugging.
2602 For some targets, GDB now supports an optional mode of operation in
2603 which you can examine stopped threads while other threads continue
2604 to execute freely. This is referred to as non-stop mode, with the
2605 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2606 section in the user manual for more information.
2608 To be able to support remote non-stop debugging, a remote stub needs
2609 to implement the non-stop mode remote protocol extensions, as
2610 described in the "Remote Non-Stop" section of the user manual. The
2611 GDB remote stub, gdbserver, has been adjusted to support these
2612 extensions on linux targets.
2614 * New commands (for set/show, see "New options" below)
2616 catch syscall [NAME(S) | NUMBER(S)]
2617 Catch system calls. Arguments, which should be names of system
2618 calls or their numbers, mean catch only those syscalls. Without
2619 arguments, every syscall will be caught. When the inferior issues
2620 any of the specified syscalls, GDB will stop and announce the system
2621 call, both when it is called and when its call returns. This
2622 feature is currently available with a native GDB running on the
2623 Linux Kernel, under the following architectures: x86, x86_64,
2624 PowerPC and PowerPC64.
2626 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2628 Search memory for a sequence of bytes.
2630 maint set python print-stack
2631 maint show python print-stack
2632 Show a stack trace when an error is encountered in a Python script.
2635 Invoke CODE by passing it to the Python interpreter.
2640 These allow macros to be defined, undefined, and listed
2644 Show operating system information about processes.
2647 List the inferiors currently under GDB's control.
2650 Switch focus to inferior number NUM.
2653 Detach from inferior number NUM.
2656 Kill inferior number NUM.
2660 set spu stop-on-load
2661 show spu stop-on-load
2662 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2664 set spu auto-flush-cache
2665 show spu auto-flush-cache
2666 Control whether to automatically flush the software-managed cache
2667 during Cell/B.E. debugging.
2669 set sh calling-convention
2670 show sh calling-convention
2671 Control the calling convention used when calling SH target functions.
2674 show debug timestamp
2675 Control display of timestamps with GDB debugging output.
2677 set disassemble-next-line
2678 show disassemble-next-line
2679 Control display of disassembled source lines or instructions when
2682 set remote noack-packet
2683 show remote noack-packet
2684 Set/show the use of remote protocol QStartNoAckMode packet. See above
2685 under "New remote packets."
2687 set remote query-attached-packet
2688 show remote query-attached-packet
2689 Control use of remote protocol `qAttached' (query-attached) packet.
2691 set remote read-siginfo-object
2692 show remote read-siginfo-object
2693 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2696 set remote write-siginfo-object
2697 show remote write-siginfo-object
2698 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2701 set remote reverse-continue
2702 show remote reverse-continue
2703 Control use of remote protocol 'bc' (reverse-continue) packet.
2705 set remote reverse-step
2706 show remote reverse-step
2707 Control use of remote protocol 'bs' (reverse-step) packet.
2709 set displaced-stepping
2710 show displaced-stepping
2711 Control displaced stepping mode. Displaced stepping is a way to
2712 single-step over breakpoints without removing them from the debuggee.
2713 Also known as "out-of-line single-stepping".
2716 show debug displaced
2717 Control display of debugging info for displaced stepping.
2719 maint set internal-error
2720 maint show internal-error
2721 Control what GDB does when an internal error is detected.
2723 maint set internal-warning
2724 maint show internal-warning
2725 Control what GDB does when an internal warning is detected.
2730 Use a wrapper program to launch programs for debugging.
2732 set multiple-symbols (all|ask|cancel)
2733 show multiple-symbols
2734 The value of this variable can be changed to adjust the debugger behavior
2735 when an expression or a breakpoint location contains an ambiguous symbol
2736 name (an overloaded function name, for instance).
2738 set breakpoint always-inserted
2739 show breakpoint always-inserted
2740 Keep breakpoints always inserted in the target, as opposed to inserting
2741 them when resuming the target, and removing them when the target stops.
2742 This option can improve debugger performance on slow remote targets.
2744 set arm fallback-mode (arm|thumb|auto)
2745 show arm fallback-mode
2746 set arm force-mode (arm|thumb|auto)
2748 These commands control how ARM GDB determines whether instructions
2749 are ARM or Thumb. The default for both settings is auto, which uses
2750 the current CPSR value for instructions without symbols; previous
2751 versions of GDB behaved as if "set arm fallback-mode arm".
2753 set disable-randomization
2754 show disable-randomization
2755 Standalone programs run with the virtual address space randomization enabled
2756 by default on some platforms. This option keeps the addresses stable across
2757 multiple debugging sessions.
2761 Control whether other threads are stopped or not when some thread hits
2766 Requests that asynchronous execution is enabled in the target, if available.
2767 In this case, it's possible to resume target in the background, and interact
2768 with GDB while the target is running. "show target-async" displays the
2769 current state of asynchronous execution of the target.
2771 set target-wide-charset
2772 show target-wide-charset
2773 The target-wide-charset is the name of the character set that GDB
2774 uses when printing characters whose type is wchar_t.
2776 set tcp auto-retry (on|off)
2778 set tcp connect-timeout
2779 show tcp connect-timeout
2780 These commands allow GDB to retry failed TCP connections to a remote stub
2781 with a specified timeout period; this is useful if the stub is launched
2782 in parallel with GDB but may not be ready to accept connections immediately.
2784 set libthread-db-search-path
2785 show libthread-db-search-path
2786 Control list of directories which GDB will search for appropriate
2789 set schedule-multiple (on|off)
2790 show schedule-multiple
2791 Allow GDB to resume all threads of all processes or only threads of
2792 the current process.
2796 Use more aggressive caching for accesses to the stack. This improves
2797 performance of remote debugging (particularly backtraces) without
2798 affecting correctness.
2800 set interactive-mode (on|off|auto)
2801 show interactive-mode
2802 Control whether GDB runs in interactive mode (on) or not (off).
2803 When in interactive mode, GDB waits for the user to answer all
2804 queries. Otherwise, GDB does not wait and assumes the default
2805 answer. When set to auto (the default), GDB determines which
2806 mode to use based on the stdin settings.
2811 For program forks, this is replaced by the new more generic `info
2812 inferiors' command. To list checkpoints, you can still use the
2813 `info checkpoints' command, which was an alias for the `info forks'
2817 Replaced by the new `inferior' command. To switch between
2818 checkpoints, you can still use the `restart' command, which was an
2819 alias for the `fork' command.
2822 This is removed, since some targets don't have a notion of
2823 processes. To switch between processes, you can still use the
2824 `inferior' command using GDB's own inferior number.
2827 For program forks, this is replaced by the new more generic `kill
2828 inferior' command. To delete a checkpoint, you can still use the
2829 `delete checkpoint' command, which was an alias for the `delete
2833 For program forks, this is replaced by the new more generic `detach
2834 inferior' command. To detach a checkpoint, you can still use the
2835 `detach checkpoint' command, which was an alias for the `detach
2838 * New native configurations
2840 x86/x86_64 Darwin i[34567]86-*-darwin*
2842 x86_64 MinGW x86_64-*-mingw*
2846 Lattice Mico32 lm32-*
2847 x86 DICOS i[34567]86-*-dicos*
2848 x86_64 DICOS x86_64-*-dicos*
2851 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2852 (mingw32ce) debugging.
2858 These commands were actually not implemented on any target.
2860 *** Changes in GDB 6.8
2862 * New native configurations
2864 NetBSD/hppa hppa*-*netbsd*
2865 Xtensa GNU/Linux xtensa*-*-linux*
2869 NetBSD/hppa hppa*-*-netbsd*
2870 Xtensa GNU/Lunux xtensa*-*-linux*
2872 * Change in command line behavior -- corefiles vs. process ids.
2874 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2875 attaching to process NUMBER fails, GDB no longer attempts to open a
2876 core file named NUMBER. Attaching to a program using the -c option
2877 is no longer supported. Instead, use the '-p' or '--pid' options.
2879 * GDB can now be built as a native debugger for debugging Windows x86
2880 (mingw32) Portable Executable (PE) programs.
2882 * Pending breakpoints no longer change their number when their address
2885 * GDB now supports breakpoints with multiple locations,
2886 including breakpoints on C++ constructors, inside C++ templates,
2887 and in inlined functions.
2889 * GDB's ability to debug optimized code has been improved. GDB more
2890 accurately identifies function bodies and lexical blocks that occupy
2891 more than one contiguous range of addresses.
2893 * Target descriptions can now describe registers for PowerPC.
2895 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2896 registers on PowerPC targets.
2898 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2899 targets even when the libthread_db library is not available.
2901 * The GDB remote stub, gdbserver, now supports the new file transfer
2902 commands (remote put, remote get, and remote delete).
2904 * The GDB remote stub, gdbserver, now supports run and attach in
2905 extended-remote mode.
2907 * hppa*64*-*-hpux11* target broken
2908 The debugger is unable to start a program and fails with the following
2909 error: "Error trying to get information about dynamic linker".
2910 The gdb-6.7 release is also affected.
2912 * GDB now supports the --enable-targets= configure option to allow
2913 building a single GDB executable that supports multiple remote
2914 target architectures.
2916 * GDB now supports debugging C and C++ programs which use the
2917 Decimal Floating Point extension. In addition, the PowerPC target
2918 now has a set of pseudo-registers to inspect decimal float values
2919 stored in two consecutive float registers.
2921 * The -break-insert MI command can optionally create pending
2924 * Improved support for debugging Ada
2925 Many improvements to the Ada language support have been made. These
2927 - Better support for Ada2005 interface types
2928 - Improved handling of arrays and slices in general
2929 - Better support for Taft-amendment types
2930 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2932 - Improved command completion in Ada
2935 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2940 set print frame-arguments (all|scalars|none)
2941 show print frame-arguments
2942 The value of this variable can be changed to control which argument
2943 values should be printed by the debugger when displaying a frame.
2948 Transfer files to and from a remote target, and delete remote files.
2955 Transfer files to and from a remote target, and delete remote files.
2957 * New remote packets
2964 Open, close, read, write, and delete files on the remote system.
2967 Attach to an existing process on the remote system, in extended-remote
2971 Run a new process on the remote system, in extended-remote mode.
2973 *** Changes in GDB 6.7
2975 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2976 bfd, libiberty and opcodes, as revealed by static analysis donated by
2977 Coverity, Inc. (http://scan.coverity.com).
2979 * When looking up multiply-defined global symbols, GDB will now prefer the
2980 symbol definition in the current shared library if it was built using the
2981 -Bsymbolic linker option.
2983 * When the Text User Interface (TUI) is not configured, GDB will now
2984 recognize the -tui command-line option and print a message that the TUI
2987 * The GDB remote stub, gdbserver, now has lower overhead for high
2988 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2990 * GDB for MIPS targets now autodetects whether a remote target provides
2991 32-bit or 64-bit register values.
2993 * Support for C++ member pointers has been improved.
2995 * GDB now understands XML target descriptions, which specify the
2996 target's overall architecture. GDB can read a description from
2997 a local file or over the remote serial protocol.
2999 * Vectors of single-byte data use a new integer type which is not
3000 automatically displayed as character or string data.
3002 * The /s format now works with the print command. It displays
3003 arrays of single-byte integers and pointers to single-byte integers
3006 * Target descriptions can now describe target-specific registers,
3007 for architectures which have implemented the support (currently
3008 only ARM, M68K, and MIPS).
3010 * GDB and the GDB remote stub, gdbserver, now support the XScale
3013 * The GDB remote stub, gdbserver, has been updated to support
3014 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3015 has been rewritten to use the standard GDB remote protocol.
3017 * GDB can now step into C++ functions which are called through thunks.
3019 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3021 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3022 layout. It also supports a TextSeg= and DataSeg= response when only
3023 segment base addresses (rather than offsets) are available.
3025 * The /i format now outputs any trailing branch delay slot instructions
3026 immediately following the last instruction within the count specified.
3028 * The GDB remote protocol "T" stop reply packet now supports a
3029 "library" response. Combined with the new "qXfer:libraries:read"
3030 packet, this response allows GDB to debug shared libraries on targets
3031 where the operating system manages the list of loaded libraries (e.g.
3032 Windows and SymbianOS).
3034 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3035 (DLLs) on Windows and Windows CE targets.
3037 * GDB now supports a faster verification that a .debug file matches its binary
3038 according to its build-id signature, if the signature is present.
3044 Enable or disable hardware flow control (RTS/CTS) on the serial port
3045 when debugging using remote targets.
3047 set mem inaccessible-by-default
3048 show mem inaccessible-by-default
3049 If the target supplies a memory map, for instance via the remote
3050 protocol's "qXfer:memory-map:read" packet, setting this variable
3051 prevents GDB from accessing memory outside the memory map. This
3052 is useful for targets with memory mapped registers or which react
3053 badly to accesses of unmapped address space.
3055 set breakpoint auto-hw
3056 show breakpoint auto-hw
3057 If the target supplies a memory map, for instance via the remote
3058 protocol's "qXfer:memory-map:read" packet, setting this variable
3059 lets GDB use hardware breakpoints automatically for memory regions
3060 where it can not use software breakpoints. This covers both the
3061 "break" command and internal breakpoints used for other commands
3062 including "next" and "finish".
3065 catch exception unhandled
3066 Stop the program execution when Ada exceptions are raised.
3069 Stop the program execution when an Ada assertion failed.
3073 Set an alternate system root for target files. This is a more
3074 general version of "set solib-absolute-prefix", which is now
3075 an alias to "set sysroot".
3078 Provide extended SPU facility status information. This set of
3079 commands is available only when debugging the Cell/B.E. SPU
3082 * New native configurations
3084 OpenBSD/sh sh*-*openbsd*
3087 unset tdesc filename
3089 Use the specified local file as an XML target description, and do
3090 not query the target for its built-in description.
3094 OpenBSD/sh sh*-*-openbsd*
3095 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3096 Toshiba Media Processor mep-elf
3098 * New remote packets
3101 Ignore the specified signals; pass them directly to the debugged program
3102 without stopping other threads or reporting them to GDB.
3104 qXfer:features:read:
3105 Read an XML target description from the target, which describes its
3110 Read or write contents of an spufs file on the target system. These
3111 packets are available only on the Cell/B.E. SPU architecture.
3113 qXfer:libraries:read:
3114 Report the loaded shared libraries. Combined with new "T" packet
3115 response, this packet allows GDB to debug shared libraries on
3116 targets where the operating system manages the list of loaded
3117 libraries (e.g. Windows and SymbianOS).
3121 Support for these obsolete configurations has been removed.
3129 i[34567]86-*-lynxos*
3130 i[34567]86-*-netware*
3131 i[34567]86-*-sco3.2v5*
3132 i[34567]86-*-sco3.2v4*
3134 i[34567]86-*-sysv4.2*
3137 i[34567]86-*-unixware2*
3138 i[34567]86-*-unixware*
3147 * Other removed features
3154 Various m68k-only ROM monitors.
3161 Various Renesas ROM monitors and debugging interfaces for SH and
3166 Support for a Macraigor serial interface to on-chip debugging.
3167 GDB does not directly support the newer parallel or USB
3172 A debug information format. The predecessor to DWARF 2 and
3173 DWARF 3, which are still supported.
3175 Support for the HP aCC compiler on HP-UX/PA-RISC
3177 SOM-encapsulated symbolic debugging information, automatic
3178 invocation of pxdb, and the aCC custom C++ ABI. This does not
3179 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3180 with aCC can still be debugged on an assembly level.
3182 MIPS ".pdr" sections
3184 A MIPS-specific format used to describe stack frame layout
3185 in debugging information.
3189 GDB could work with an older version of Guile to debug
3190 the interpreter and Scheme programs running in it.
3192 set mips stack-arg-size
3193 set mips saved-gpreg-size
3195 Use "set mips abi" to control parameter passing for MIPS.
3197 *** Changes in GDB 6.6
3202 Cell Broadband Engine SPU spu-elf
3204 * GDB can now be configured as a cross-debugger targeting native Windows
3205 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3206 running on a Windows system over TCP/IP to debug Windows programs.
3208 * The GDB remote stub, gdbserver, has been updated to support Windows and
3209 Cygwin debugging. Both single-threaded and multi-threaded programs are
3212 * The "set trust-readonly-sections" command works again. This command was
3213 broken in GDB 6.3, 6.4, and 6.5.
3215 * The "load" command now supports writing to flash memory, if the remote
3216 stub provides the required support.
3218 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3219 longer requires symbolic debug information (e.g. DWARF-2).
3224 unset substitute-path
3225 show substitute-path
3226 Manage a list of substitution rules that GDB uses to rewrite the name
3227 of the directories where the sources are located. This can be useful
3228 for instance when the sources were moved to a different location
3229 between compilation and debugging.
3233 Print each CLI command as it is executed. Each command is prefixed with
3234 a number of `+' symbols representing the nesting depth.
3235 The source command now has a `-v' option to enable the same feature.
3239 The ARM Demon monitor support (RDP protocol, "target rdp").
3241 Kernel Object Display, an embedded debugging feature which only worked with
3242 an obsolete version of Cisco IOS.
3244 The 'set download-write-size' and 'show download-write-size' commands.
3246 * New remote packets
3249 Tell a stub about GDB client features, and request remote target features.
3250 The first feature implemented is PacketSize, which allows the target to
3251 specify the size of packets it can handle - to minimize the number of
3252 packets required and improve performance when connected to a remote
3256 Fetch an OS auxilliary vector from the remote stub. This packet is a
3257 more efficient replacement for qPart:auxv:read.
3259 qXfer:memory-map:read:
3260 Fetch a memory map from the remote stub, including information about
3261 RAM, ROM, and flash memory devices.
3266 Erase and program a flash memory device.
3268 * Removed remote packets
3271 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3272 used it, and only gdbserver implemented it.
3274 *** Changes in GDB 6.5
3278 Renesas M32C/M16C m32c-elf
3280 Morpho Technologies ms1 ms1-elf
3284 init-if-undefined Initialize a convenience variable, but
3285 only if it doesn't already have a value.
3287 The following commands are presently only implemented for native GNU/Linux:
3289 checkpoint Save a snapshot of the program state.
3291 restart <n> Return the program state to a
3292 previously saved state.
3294 info checkpoints List currently saved checkpoints.
3296 delete-checkpoint <n> Delete a previously saved checkpoint.
3298 set|show detach-on-fork Tell gdb whether to detach from a newly
3299 forked process, or to keep debugging it.
3301 info forks List forks of the user program that
3302 are available to be debugged.
3304 fork <n> Switch to debugging one of several
3305 forks of the user program that are
3306 available to be debugged.
3308 delete-fork <n> Delete a fork from the list of forks
3309 that are available to be debugged (and
3310 kill the forked process).
3312 detach-fork <n> Delete a fork from the list of forks
3313 that are available to be debugged (and
3314 allow the process to continue).
3318 Morpho Technologies ms2 ms1-elf
3320 * Improved Windows host support
3322 GDB now builds as a cross debugger hosted on i686-mingw32, including
3323 native console support, and remote communications using either
3324 network sockets or serial ports.
3326 * Improved Modula-2 language support
3328 GDB can now print most types in the Modula-2 syntax. This includes:
3329 basic types, set types, record types, enumerated types, range types,
3330 pointer types and ARRAY types. Procedure var parameters are correctly
3331 printed and hexadecimal addresses and character constants are also
3332 written in the Modula-2 syntax. Best results can be obtained by using
3333 GNU Modula-2 together with the -gdwarf-2 command line option.
3337 The ARM rdi-share module.
3339 The Netware NLM debug server.
3341 *** Changes in GDB 6.4
3343 * New native configurations
3345 OpenBSD/arm arm*-*-openbsd*
3346 OpenBSD/mips64 mips64-*-openbsd*
3350 Morpho Technologies ms1 ms1-elf
3352 * New command line options
3354 --batch-silent As for --batch, but totally silent.
3355 --return-child-result The debugger will exist with the same value
3356 the child (debugged) program exited with.
3357 --eval-command COMMAND, -ex COMMAND
3358 Execute a single GDB CLI command. This may be
3359 specified multiple times and in conjunction
3360 with the --command (-x) option.
3362 * Deprecated commands removed
3364 The following commands, that were deprecated in 2000, have been
3368 set|show arm disassembly-flavor set|show arm disassembler
3369 othernames set arm disassembler
3370 set|show remotedebug set|show debug remote
3371 set|show archdebug set|show debug arch
3372 set|show eventdebug set|show debug event
3375 * New BSD user-level threads support
3377 It is now possible to debug programs using the user-level threads
3378 library on OpenBSD and FreeBSD. Currently supported (target)
3381 FreeBSD/amd64 x86_64-*-freebsd*
3382 FreeBSD/i386 i386-*-freebsd*
3383 OpenBSD/i386 i386-*-openbsd*
3385 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3386 are not yet supported.
3388 * New support for Matsushita MN10300 w/sim added
3389 (Work in progress). mn10300-elf.
3391 * REMOVED configurations and files
3393 VxWorks and the XDR protocol *-*-vxworks
3394 Motorola MCORE mcore-*-*
3395 National Semiconductor NS32000 ns32k-*-*
3397 * New "set print array-indexes" command
3399 After turning this setting "on", GDB prints the index of each element
3400 when displaying arrays. The default is "off" to preserve the previous
3403 * VAX floating point support
3405 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3407 * User-defined command support
3409 In addition to using $arg0..$arg9 for argument passing, it is now possible
3410 to use $argc to determine now many arguments have been passed. See the
3411 section on user-defined commands in the user manual for more information.
3413 *** Changes in GDB 6.3:
3415 * New command line option
3417 GDB now accepts -l followed by a number to set the timeout for remote
3420 * GDB works with GCC -feliminate-dwarf2-dups
3422 GDB now supports a more compact representation of DWARF-2 debug
3423 information using DW_FORM_ref_addr references. These are produced
3424 by GCC with the option -feliminate-dwarf2-dups and also by some
3425 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3426 to use -feliminate-dwarf2-dups.
3428 * Internationalization
3430 When supported by the host system, GDB will be built with
3431 internationalization (libintl). The task of marking up the sources is
3432 continued, we're looking forward to our first translation.
3436 Initial support for debugging programs compiled with the GNAT
3437 implementation of the Ada programming language has been integrated
3438 into GDB. In this release, support is limited to expression evaluation.
3440 * New native configurations
3442 GNU/Linux/m32r m32r-*-linux-gnu
3446 GDB's remote protocol now includes support for the 'p' packet. This
3447 packet is used to fetch individual registers from a remote inferior.
3449 * END-OF-LIFE registers[] compatibility module
3451 GDB's internal register infrastructure has been completely rewritten.
3452 The new infrastructure making possible the implementation of key new
3453 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3456 GDB 6.3 will be the last release to include the the registers[]
3457 compatibility module that allowed out-of-date configurations to
3458 continue to work. This change directly impacts the following
3468 powerpc bdm protocol
3470 Unless there is activity to revive these configurations, they will be
3471 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3473 * OBSOLETE configurations and files
3475 Configurations that have been declared obsolete in this release have
3476 been commented out. Unless there is activity to revive these
3477 configurations, the next release of GDB will have their sources
3478 permanently REMOVED.
3487 *** Changes in GDB 6.2.1:
3489 * MIPS `break main; run' gave an heuristic-fence-post warning
3491 When attempting to run even a simple program, a warning about
3492 heuristic-fence-post being hit would be reported. This problem has
3495 * MIPS IRIX 'long double' crashed GDB
3497 When examining a long double variable, GDB would get a segmentation
3498 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3499 IRIX long double values).
3503 A bug in the VAX stack code was causing problems with the "next"
3504 command. This problem has been fixed.
3506 *** Changes in GDB 6.2:
3508 * Fix for ``many threads''
3510 On GNU/Linux systems that use the NPTL threads library, a program
3511 rapidly creating and deleting threads would confuse GDB leading to the
3514 ptrace: No such process.
3515 thread_db_get_info: cannot get thread info: generic error
3517 This problem has been fixed.
3519 * "-async" and "-noasync" options removed.
3521 Support for the broken "-noasync" option has been removed (it caused
3524 * New ``start'' command.
3526 This command runs the program until the begining of the main procedure.
3528 * New BSD Kernel Data Access Library (libkvm) interface
3530 Using ``target kvm'' it is now possible to debug kernel core dumps and
3531 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3532 platforms. Currently supported (native-only) configurations are:
3534 FreeBSD/amd64 x86_64-*-freebsd*
3535 FreeBSD/i386 i?86-*-freebsd*
3536 NetBSD/i386 i?86-*-netbsd*
3537 NetBSD/m68k m68*-*-netbsd*
3538 NetBSD/sparc sparc-*-netbsd*
3539 OpenBSD/amd64 x86_64-*-openbsd*
3540 OpenBSD/i386 i?86-*-openbsd*
3541 OpenBSD/m68k m68*-openbsd*
3542 OpenBSD/sparc sparc-*-openbsd*
3544 * Signal trampoline code overhauled
3546 Many generic problems with GDB's signal handling code have been fixed.
3547 These include: backtraces through non-contiguous stacks; recognition
3548 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3549 call; backtrace through a signal trampoline; step into and out of
3550 signal handlers; and single-stepping in the signal trampoline.
3552 Please note that kernel bugs are a limiting factor here. These
3553 features have been shown to work on an s390 GNU/Linux system that
3554 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3556 * Cygwin support for DWARF 2 added.
3558 * New native configurations
3560 GNU/Linux/hppa hppa*-*-linux*
3561 OpenBSD/hppa hppa*-*-openbsd*
3562 OpenBSD/m68k m68*-*-openbsd*
3563 OpenBSD/m88k m88*-*-openbsd*
3564 OpenBSD/powerpc powerpc-*-openbsd*
3565 NetBSD/vax vax-*-netbsd*
3566 OpenBSD/vax vax-*-openbsd*
3568 * END-OF-LIFE frame compatibility module
3570 GDB's internal frame infrastructure has been completely rewritten.
3571 The new infrastructure making it possible to support key new features
3572 including DWARF 2 Call Frame Information. To aid in the task of
3573 migrating old configurations to this new infrastructure, a
3574 compatibility module, that allowed old configurations to continue to
3575 work, was also included.
3577 GDB 6.2 will be the last release to include this frame compatibility
3578 module. This change directly impacts the following configurations:
3588 Unless there is activity to revive these configurations, they will be
3589 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3591 * REMOVED configurations and files
3593 Sun 3, running SunOS 3 m68*-*-sunos3*
3594 Sun 3, running SunOS 4 m68*-*-sunos4*
3595 Sun 2, running SunOS 3 m68000-*-sunos3*
3596 Sun 2, running SunOS 4 m68000-*-sunos4*
3597 Motorola 680x0 running LynxOS m68*-*-lynxos*
3598 AT&T 3b1/Unix pc m68*-att-*
3599 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3600 decstation mips-dec-* mips-little-*
3601 riscos mips-*-riscos* mips-*-sysv*
3602 sonymips mips-sony-*
3603 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3605 *** Changes in GDB 6.1.1:
3607 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3609 The TUI (Text-mode User Interface) is now built as part of a default
3610 GDB configuration. It is enabled by either selecting the TUI with the
3611 command line option "-i=tui" or by running the separate "gdbtui"
3612 program. For more information on the TUI, see the manual "Debugging
3615 * Pending breakpoint support (also included in GDB 6.1)
3617 Support has been added to allow you to specify breakpoints in shared
3618 libraries that have not yet been loaded. If a breakpoint location
3619 cannot be found, and the "breakpoint pending" option is set to auto,
3620 GDB queries you if you wish to make the breakpoint pending on a future
3621 shared-library load. If and when GDB resolves the breakpoint symbol,
3622 the pending breakpoint is removed as one or more regular breakpoints
3625 Pending breakpoints are very useful for GCJ Java debugging.
3627 * Fixed ISO-C build problems
3629 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3630 non ISO-C code that stopped them being built using a more strict ISO-C
3631 compiler (e.g., IBM's C compiler).
3633 * Fixed build problem on IRIX 5
3635 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3636 wasn't able to compile compile on an IRIX 5 system.
3638 * Added execute permission to gdb/gdbserver/configure
3640 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3641 permission. This bug would cause configure to fail on a number of
3642 systems (Solaris, IRIX). Ref: server/519.
3644 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3646 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3647 has been updated to use constant array sizes.
3649 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3651 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3652 its generated DWARF Call Frame Info. This encoding was causing GDB to
3653 panic, that panic has been fixed. Ref: gdb/1628.
3655 * Fixed a problem when examining parameters in shared library code.
3657 When examining parameters in optimized shared library code generated
3658 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3659 not available''. GDB now correctly displays the variable's value.
3661 *** Changes in GDB 6.1:
3663 * Removed --with-mmalloc
3665 Support for the mmalloc memory manager has been removed, as it
3666 conflicted with the internal gdb byte cache.
3668 * Changes in AMD64 configurations
3670 The AMD64 target now includes the %cs and %ss registers. As a result
3671 the AMD64 remote protocol has changed; this affects the floating-point
3672 and SSE registers. If you rely on those registers for your debugging,
3673 you should upgrade gdbserver on the remote side.
3675 * Revised SPARC target
3677 The SPARC target has been completely revised, incorporating the
3678 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3679 support for LynxOS and SunOS 4 has been dropped. Calling functions
3680 from within GDB on operating systems with a non-executable stack
3681 (Solaris, OpenBSD) now works.
3685 GDB has a new C++ demangler which does a better job on the mangled
3686 names generated by current versions of g++. It also runs faster, so
3687 with this and other changes gdb should now start faster on large C++
3690 * DWARF 2 Location Expressions
3692 GDB support for location expressions has been extended to support function
3693 arguments and frame bases. Older versions of GDB could crash when they
3696 * C++ nested types and namespaces
3698 GDB's support for nested types and namespaces in C++ has been
3699 improved, especially if you use the DWARF 2 debugging format. (This
3700 is the default for recent versions of GCC on most platforms.)
3701 Specifically, if you have a class "Inner" defined within a class or
3702 namespace "Outer", then GDB realizes that the class's name is
3703 "Outer::Inner", not simply "Inner". This should greatly reduce the
3704 frequency of complaints about not finding RTTI symbols. In addition,
3705 if you are stopped at inside of a function defined within a namespace,
3706 GDB modifies its name lookup accordingly.
3708 * New native configurations
3710 NetBSD/amd64 x86_64-*-netbsd*
3711 OpenBSD/amd64 x86_64-*-openbsd*
3712 OpenBSD/alpha alpha*-*-openbsd*
3713 OpenBSD/sparc sparc-*-openbsd*
3714 OpenBSD/sparc64 sparc64-*-openbsd*
3716 * New debugging protocols
3718 M32R with SDI protocol m32r-*-elf*
3720 * "set prompt-escape-char" command deleted.
3722 The command "set prompt-escape-char" has been deleted. This command,
3723 and its very obscure effet on GDB's prompt, was never documented,
3724 tested, nor mentioned in the NEWS file.
3726 * OBSOLETE configurations and files
3728 Configurations that have been declared obsolete in this release have
3729 been commented out. Unless there is activity to revive these
3730 configurations, the next release of GDB will have their sources
3731 permanently REMOVED.
3733 Sun 3, running SunOS 3 m68*-*-sunos3*
3734 Sun 3, running SunOS 4 m68*-*-sunos4*
3735 Sun 2, running SunOS 3 m68000-*-sunos3*
3736 Sun 2, running SunOS 4 m68000-*-sunos4*
3737 Motorola 680x0 running LynxOS m68*-*-lynxos*
3738 AT&T 3b1/Unix pc m68*-att-*
3739 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3740 decstation mips-dec-* mips-little-*
3741 riscos mips-*-riscos* mips-*-sysv*
3742 sonymips mips-sony-*
3743 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3745 * REMOVED configurations and files
3747 SGI Irix-4.x mips-sgi-irix4 or iris4
3748 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3749 Z8000 simulator z8k-zilog-none or z8ksim
3750 Matsushita MN10200 w/simulator mn10200-*-*
3751 H8/500 simulator h8500-hitachi-hms or h8500hms
3752 HP/PA running BSD hppa*-*-bsd*
3753 HP/PA running OSF/1 hppa*-*-osf*
3754 HP/PA Pro target hppa*-*-pro*
3755 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3756 386BSD i[3456]86-*-bsd*
3757 Sequent family i[3456]86-sequent-sysv4*
3758 i[3456]86-sequent-sysv*
3759 i[3456]86-sequent-bsd*
3760 SPARC running LynxOS sparc-*-lynxos*
3761 SPARC running SunOS 4 sparc-*-sunos4*
3762 Tsqware Sparclet sparclet-*-*
3763 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3765 *** Changes in GDB 6.0:
3769 Support for debugging the Objective-C programming language has been
3770 integrated into GDB.
3772 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3774 DWARF 2's Call Frame Information makes available compiler generated
3775 information that more exactly describes the program's run-time stack.
3776 By using this information, GDB is able to provide more robust stack
3779 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3780 have been updated to use a new backtrace mechanism which includes
3781 DWARF 2 CFI support.
3785 GDB's remote protocol has been extended to include support for hosted
3786 file I/O (where the remote target uses GDB's file system). See GDB's
3787 remote protocol documentation for details.
3789 * All targets using the new architecture framework.
3791 All of GDB's targets have been updated to use the new internal
3792 architecture framework. The way is now open for future GDB releases
3793 to include cross-architecture native debugging support (i386 on amd64,
3796 * GNU/Linux's Thread Local Storage (TLS)
3798 GDB now includes support for for the GNU/Linux implementation of
3799 per-thread variables.
3801 * GNU/Linux's Native POSIX Thread Library (NPTL)
3803 GDB's thread code has been updated to work with either the new
3804 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3806 * Separate debug info.
3808 GDB, in conjunction with BINUTILS, now supports a mechanism for
3809 automatically loading debug information from a separate file. Instead
3810 of shipping full debug and non-debug versions of system libraries,
3811 system integrators can now instead ship just the stripped libraries
3812 and optional debug files.
3814 * DWARF 2 Location Expressions
3816 DWARF 2 Location Expressions allow the compiler to more completely
3817 describe the location of variables (even in optimized code) to the
3820 GDB now includes preliminary support for location expressions (support
3821 for DW_OP_piece is still missing).
3825 A number of long standing bugs that caused GDB to die while starting a
3826 Java application have been fixed. GDB's Java support is now
3827 considered "useable".
3829 * GNU/Linux support for fork, vfork, and exec.
3831 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3832 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3835 * GDB supports logging output to a file
3837 There are two new commands, "set logging" and "show logging", which can be
3838 used to capture GDB's output to a file.
3840 * The meaning of "detach" has changed for gdbserver
3842 The "detach" command will now resume the application, as documented. To
3843 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3846 * d10v, m68hc11 `regs' command deprecated
3848 The `info registers' command has been updated so that it displays the
3849 registers using a format identical to the old `regs' command.
3853 A new command, "maint set profile on/off", has been added. This command can
3854 be used to enable or disable profiling while running GDB, to profile a
3855 session or a set of commands. In addition there is a new configure switch,
3856 "--enable-profiling", which will cause GDB to be compiled with profiling
3857 data, for more informative profiling results.
3859 * Default MI syntax changed to "mi2".
3861 The default MI (machine interface) syntax, enabled by the command line
3862 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3863 "mi1", can be enabled by specifying the option "-i=mi1".
3865 Support for the original "mi0" syntax (included in GDB 5.0) has been
3868 Fix for gdb/192: removed extraneous space when displaying frame level.
3869 Fix for gdb/672: update changelist is now output in mi list format.
3870 Fix for gdb/702: a -var-assign that updates the value now shows up
3871 in a subsequent -var-update.
3873 * New native configurations.
3875 FreeBSD/amd64 x86_64-*-freebsd*
3877 * Multi-arched targets.
3879 HP/PA HPUX11 hppa*-*-hpux*
3880 Renesas M32R/D w/simulator m32r-*-elf*
3882 * OBSOLETE configurations and files
3884 Configurations that have been declared obsolete in this release have
3885 been commented out. Unless there is activity to revive these
3886 configurations, the next release of GDB will have their sources
3887 permanently REMOVED.
3889 Z8000 simulator z8k-zilog-none or z8ksim
3890 Matsushita MN10200 w/simulator mn10200-*-*
3891 H8/500 simulator h8500-hitachi-hms or h8500hms
3892 HP/PA running BSD hppa*-*-bsd*
3893 HP/PA running OSF/1 hppa*-*-osf*
3894 HP/PA Pro target hppa*-*-pro*
3895 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3896 Sequent family i[3456]86-sequent-sysv4*
3897 i[3456]86-sequent-sysv*
3898 i[3456]86-sequent-bsd*
3899 Tsqware Sparclet sparclet-*-*
3900 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3902 * REMOVED configurations and files
3905 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3906 IBM AIX PS/2 i[3456]86-*-aix
3907 i386 running Mach 3.0 i[3456]86-*-mach3*
3908 i386 running Mach i[3456]86-*-mach*
3909 i386 running OSF/1 i[3456]86-*osf1mk*
3910 HP/Apollo 68k Family m68*-apollo*-sysv*,
3912 m68*-hp-bsd*, m68*-hp-hpux*
3913 Argonaut Risc Chip (ARC) arc-*-*
3914 Mitsubishi D30V d30v-*-*
3915 Fujitsu FR30 fr30-*-elf*
3916 OS/9000 i[34]86-*-os9k
3917 I960 with MON960 i960-*-coff
3919 * MIPS $fp behavior changed
3921 The convenience variable $fp, for the MIPS, now consistently returns
3922 the address of the current frame's base. Previously, depending on the
3923 context, $fp could refer to either $sp or the current frame's base
3924 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3925 The GNU Source-Level Debugger''.
3927 *** Changes in GDB 5.3:
3929 * GNU/Linux shared library multi-threaded performance improved.
3931 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3932 `/proc', in preference to `ptrace' for memory reads. This may result
3933 in an improvement in the start-up time of multi-threaded, shared
3934 library applications when run under GDB. One GDB user writes: ``loads
3935 shared libs like mad''.
3937 * ``gdbserver'' now supports multi-threaded applications on some targets
3939 Support for debugging multi-threaded applications which use
3940 the GNU/Linux LinuxThreads package has been added for
3941 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3942 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3944 * GDB now supports C/C++ preprocessor macros.
3946 GDB now expands preprocessor macro invocations in C/C++ expressions,
3947 and provides various commands for showing macro definitions and how
3950 The new command `macro expand EXPRESSION' expands any macro
3951 invocations in expression, and shows the result.
3953 The new command `show macro MACRO-NAME' shows the definition of the
3954 macro named MACRO-NAME, and where it was defined.
3956 Most compilers don't include information about macros in the debugging
3957 information by default. In GCC 3.1, for example, you need to compile
3958 your program with the options `-gdwarf-2 -g3'. If the macro
3959 information is present in the executable, GDB will read it.
3961 * Multi-arched targets.
3963 DEC Alpha (partial) alpha*-*-*
3964 DEC VAX (partial) vax-*-*
3966 National Semiconductor NS32000 (partial) ns32k-*-*
3967 Motorola 68000 (partial) m68k-*-*
3968 Motorola MCORE mcore-*-*
3972 Fujitsu FRV architecture added by Red Hat frv*-*-*
3975 * New native configurations
3977 Alpha NetBSD alpha*-*-netbsd*
3978 SH NetBSD sh*-*-netbsdelf*
3979 MIPS NetBSD mips*-*-netbsd*
3980 UltraSPARC NetBSD sparc64-*-netbsd*
3982 * OBSOLETE configurations and files
3984 Configurations that have been declared obsolete in this release have
3985 been commented out. Unless there is activity to revive these
3986 configurations, the next release of GDB will have their sources
3987 permanently REMOVED.
3989 Mitsubishi D30V d30v-*-*
3990 OS/9000 i[34]86-*-os9k
3991 IBM AIX PS/2 i[3456]86-*-aix
3992 Fujitsu FR30 fr30-*-elf*
3993 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3994 Argonaut Risc Chip (ARC) arc-*-*
3995 i386 running Mach 3.0 i[3456]86-*-mach3*
3996 i386 running Mach i[3456]86-*-mach*
3997 i386 running OSF/1 i[3456]86-*osf1mk*
3998 HP/Apollo 68k Family m68*-apollo*-sysv*,
4000 m68*-hp-bsd*, m68*-hp-hpux*
4001 I960 with MON960 i960-*-coff
4003 * OBSOLETE languages
4005 CHILL, a Pascal like language used by telecommunications companies.
4007 * REMOVED configurations and files
4009 AMD 29k family via UDI a29k-amd-udi, udi29k
4010 A29K VxWorks a29k-*-vxworks
4011 AMD 29000 embedded, using EBMON a29k-none-none
4012 AMD 29000 embedded with COFF a29k-none-coff
4013 AMD 29000 embedded with a.out a29k-none-aout
4015 testsuite/gdb.hp/gdb.threads-hp/ directory
4017 * New command "set max-user-call-depth <nnn>"
4019 This command allows the user to limit the call depth of user-defined
4020 commands. The default is 1024.
4022 * Changes in FreeBSD/i386 native debugging.
4024 Support for the "generate-core-file" has been added.
4026 * New commands "dump", "append", and "restore".
4028 These commands allow data to be copied from target memory
4029 to a bfd-format or binary file (dump and append), and back
4030 from a file into memory (restore).
4032 * Improved "next/step" support on multi-processor Alpha Tru64.
4034 The previous single-step mechanism could cause unpredictable problems,
4035 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4036 of a software single-step mechanism prevents this.
4038 *** Changes in GDB 5.2.1:
4046 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4047 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4048 Fix, by Joel Brobecker imported from mainline.
4050 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4051 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4052 Fix, by Fred Fish, imported from mainline.
4054 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4055 Surprisingly enough, it works now.
4056 By Michal Ludvig, imported from mainline.
4058 i386 hardware watchpoint support:
4059 avoid misses on second run for some targets.
4060 By Pierre Muller, imported from mainline.
4062 *** Changes in GDB 5.2:
4064 * New command "set trust-readonly-sections on[off]".
4066 This command is a hint that tells gdb that read-only sections
4067 really are read-only (ie. that their contents will not change).
4068 In this mode, gdb will go to the object file rather than the
4069 target to read memory from read-only sections (such as ".text").
4070 This can be a significant performance improvement on some
4071 (notably embedded) targets.
4073 * New command "generate-core-file" (or "gcore").
4075 This new gdb command allows the user to drop a core file of the child
4076 process state at any time. So far it's been implemented only for
4077 GNU/Linux and Solaris, but should be relatively easily ported to other
4078 hosts. Argument is core file name (defaults to core.<pid>).
4080 * New command line option
4082 GDB now accepts --pid or -p followed by a process id.
4084 * Change in command line behavior -- corefiles vs. process ids.
4086 There is a subtle behavior in the way in which GDB handles
4087 command line arguments. The first non-flag argument is always
4088 a program to debug, but the second non-flag argument may either
4089 be a corefile or a process id. Previously, GDB would attempt to
4090 open the second argument as a corefile, and if that failed, would
4091 issue a superfluous error message and then attempt to attach it as
4092 a process. Now, if the second argument begins with a non-digit,
4093 it will be treated as a corefile. If it begins with a digit,
4094 GDB will attempt to attach it as a process, and if no such process
4095 is found, will then attempt to open it as a corefile.
4097 * Changes in ARM configurations.
4099 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4100 configuration is fully multi-arch.
4102 * New native configurations
4104 ARM NetBSD arm*-*-netbsd*
4105 x86 OpenBSD i[3456]86-*-openbsd*
4106 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4107 Sparc64 running FreeBSD sparc64-*-freebsd*
4111 Sanyo XStormy16 xstormy16-elf
4113 * OBSOLETE configurations and files
4115 Configurations that have been declared obsolete in this release have
4116 been commented out. Unless there is activity to revive these
4117 configurations, the next release of GDB will have their sources
4118 permanently REMOVED.
4120 AMD 29k family via UDI a29k-amd-udi, udi29k
4121 A29K VxWorks a29k-*-vxworks
4122 AMD 29000 embedded, using EBMON a29k-none-none
4123 AMD 29000 embedded with COFF a29k-none-coff
4124 AMD 29000 embedded with a.out a29k-none-aout
4126 testsuite/gdb.hp/gdb.threads-hp/ directory
4128 * REMOVED configurations and files
4130 TI TMS320C80 tic80-*-*
4132 PowerPC Solaris powerpcle-*-solaris*
4133 PowerPC Windows NT powerpcle-*-cygwin32
4134 PowerPC Netware powerpc-*-netware*
4135 Harris/CXUX m88k m88*-harris-cxux*
4136 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4137 ns32k-utek-sysv* ns32k-utek-*
4138 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4139 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4140 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4141 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4142 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4144 * Changes to command line processing
4146 The new `--args' feature can be used to specify command-line arguments
4147 for the inferior from gdb's command line.
4149 * Changes to key bindings
4151 There is a new `operate-and-get-next' function bound to `C-o'.
4153 *** Changes in GDB 5.1.1
4155 Fix compile problem on DJGPP.
4157 Fix a problem with floating-point registers on the i386 being
4160 Fix to stop GDB crashing on .debug_str debug info.
4162 Numerous documentation fixes.
4164 Numerous testsuite fixes.
4166 *** Changes in GDB 5.1:
4168 * New native configurations
4170 Alpha FreeBSD alpha*-*-freebsd*
4171 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4172 MIPS GNU/Linux mips*-*-linux*
4173 MIPS SGI Irix 6.x mips*-sgi-irix6*
4174 ia64 AIX ia64-*-aix*
4175 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4179 Motorola 68HC11 and 68HC12 m68hc11-elf
4181 UltraSparc running GNU/Linux sparc64-*-linux*
4183 * OBSOLETE configurations and files
4185 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4186 Harris/CXUX m88k m88*-harris-cxux*
4187 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4188 ns32k-utek-sysv* ns32k-utek-*
4189 TI TMS320C80 tic80-*-*
4191 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4192 PowerPC Solaris powerpcle-*-solaris*
4193 PowerPC Windows NT powerpcle-*-cygwin32
4194 PowerPC Netware powerpc-*-netware*
4195 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4196 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4197 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4198 Apple Macintosh (MPW) host N/A
4200 stuff.c (Program to stuff files into a specially prepared space in kdb)
4201 kdb-start.c (Main loop for the standalone kernel debugger)
4203 Configurations that have been declared obsolete in this release have
4204 been commented out. Unless there is activity to revive these
4205 configurations, the next release of GDB will have their sources
4206 permanently REMOVED.
4208 * REMOVED configurations and files
4210 Altos 3068 m68*-altos-*
4211 Convex c1-*-*, c2-*-*
4213 ARM RISCix arm-*-* (as host)
4217 * GDB has been converted to ISO C.
4219 GDB's source code has been converted to ISO C. In particular, the
4220 sources are fully protoized, and rely on standard headers being
4225 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4227 * The MI enabled by default.
4229 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4230 revised and enabled by default. Packages which use GDB as a debugging
4231 engine behind a UI or another front end are encouraged to switch to
4232 using the GDB/MI interface, instead of the old annotations interface
4233 which is now deprecated.
4235 * Support for debugging Pascal programs.
4237 GDB now includes support for debugging Pascal programs. The following
4238 main features are supported:
4240 - Pascal-specific data types such as sets;
4242 - automatic recognition of Pascal sources based on file-name
4245 - Pascal-style display of data types, variables, and functions;
4247 - a Pascal expression parser.
4249 However, some important features are not yet supported.
4251 - Pascal string operations are not supported at all;
4253 - there are some problems with boolean types;
4255 - Pascal type hexadecimal constants are not supported
4256 because they conflict with the internal variables format;
4258 - support for Pascal objects and classes is not full yet;
4260 - unlike Pascal, GDB is case-sensitive for symbol names.
4262 * Changes in completion.
4264 Commands such as `shell', `run' and `set args', which pass arguments
4265 to inferior programs, now complete on file names, similar to what
4266 users expect at the shell prompt.
4268 Commands which accept locations, such as `disassemble', `print',
4269 `breakpoint', `until', etc. now complete on filenames as well as
4270 program symbols. Thus, if you type "break foob TAB", and the source
4271 files linked into the programs include `foobar.c', that file name will
4272 be one of the candidates for completion. However, file names are not
4273 considered for completion after you typed a colon that delimits a file
4274 name from a name of a function in that file, as in "break foo.c:bar".
4276 `set demangle-style' completes on available demangling styles.
4278 * New platform-independent commands:
4280 It is now possible to define a post-hook for a command as well as a
4281 hook that runs before the command. For more details, see the
4282 documentation of `hookpost' in the GDB manual.
4284 * Changes in GNU/Linux native debugging.
4286 Support for debugging multi-threaded programs has been completely
4287 revised for all platforms except m68k and sparc. You can now debug as
4288 many threads as your system allows you to have.
4290 Attach/detach is supported for multi-threaded programs.
4292 Support for SSE registers was added for x86. This doesn't work for
4293 multi-threaded programs though.
4295 * Changes in MIPS configurations.
4297 Multi-arch support is enabled for all MIPS configurations.
4299 GDB can now be built as native debugger on SGI Irix 6.x systems for
4300 debugging n32 executables. (Debugging 64-bit executables is not yet
4303 * Unified support for hardware watchpoints in all x86 configurations.
4305 Most (if not all) native x86 configurations support hardware-assisted
4306 breakpoints and watchpoints in a unified manner. This support
4307 implements debug register sharing between watchpoints, which allows to
4308 put a virtually infinite number of watchpoints on the same address,
4309 and also supports watching regions up to 16 bytes with several debug
4312 The new maintenance command `maintenance show-debug-regs' toggles
4313 debugging print-outs in functions that insert, remove, and test
4314 watchpoints and hardware breakpoints.
4316 * Changes in the DJGPP native configuration.
4318 New command ``info dos sysinfo'' displays assorted information about
4319 the CPU, OS, memory, and DPMI server.
4321 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4322 display information about segment descriptors stored in GDT, LDT, and
4325 New commands ``info dos pde'' and ``info dos pte'' display entries
4326 from Page Directory and Page Tables (for now works with CWSDPMI only).
4327 New command ``info dos address-pte'' displays the Page Table entry for
4328 a given linear address.
4330 GDB can now pass command lines longer than 126 characters to the
4331 program being debugged (requires an update to the libdbg.a library
4332 which is part of the DJGPP development kit).
4334 DWARF2 debug info is now supported.
4336 It is now possible to `step' and `next' through calls to `longjmp'.
4338 * Changes in documentation.
4340 All GDB documentation was converted to GFDL, the GNU Free
4341 Documentation License.
4343 Tracepoints-related commands are now fully documented in the GDB
4346 TUI, the Text-mode User Interface, is now documented in the manual.
4348 Tracepoints-related commands are now fully documented in the GDB
4351 The "GDB Internals" manual now has an index. It also includes
4352 documentation of `ui_out' functions, GDB coding standards, x86
4353 hardware watchpoints, and memory region attributes.
4355 * GDB's version number moved to ``version.in''
4357 The Makefile variable VERSION has been replaced by the file
4358 ``version.in''. People creating GDB distributions should update the
4359 contents of this file.
4363 GUD support is now a standard part of the EMACS distribution.
4365 *** Changes in GDB 5.0:
4367 * Improved support for debugging FP programs on x86 targets
4369 Unified and much-improved support for debugging floating-point
4370 programs on all x86 targets. In particular, ``info float'' now
4371 displays the FP registers in the same format on all x86 targets, with
4372 greater level of detail.
4374 * Improvements and bugfixes in hardware-assisted watchpoints
4376 It is now possible to watch array elements, struct members, and
4377 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4378 on x86 targets no longer erroneously trigger when the address is
4381 * Improvements in the native DJGPP version of GDB
4383 The distribution now includes all the scripts and auxiliary files
4384 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4385 machines ``out of the box''.
4387 The DJGPP version can now debug programs that use signals. It is
4388 possible to catch signals that happened in the debuggee, deliver
4389 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4390 would kill the program being debugged.) Programs that hook hardware
4391 interrupts (keyboard, timer, etc.) can also be debugged.
4393 It is now possible to debug DJGPP programs that redirect their
4394 standard handles or switch them to raw (as opposed to cooked) mode, or
4395 even close them. The command ``run < foo > bar'' works as expected,
4396 and ``info terminal'' reports useful information about the debuggee's
4397 terminal, including raw/cooked mode, redirection, etc.
4399 The DJGPP version now uses termios functions for console I/O, which
4400 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4403 DOS-style file names with drive letters are now fully supported by
4406 It is now possible to debug DJGPP programs that switch their working
4407 directory. It is also possible to rerun the debuggee any number of
4408 times without restarting GDB; thus, you can use the same setup,
4409 breakpoints, etc. for many debugging sessions.
4411 * New native configurations
4413 ARM GNU/Linux arm*-*-linux*
4414 PowerPC GNU/Linux powerpc-*-linux*
4418 Motorola MCore mcore-*-*
4419 x86 VxWorks i[3456]86-*-vxworks*
4420 PowerPC VxWorks powerpc-*-vxworks*
4421 TI TMS320C80 tic80-*-*
4423 * OBSOLETE configurations
4425 Altos 3068 m68*-altos-*
4426 Convex c1-*-*, c2-*-*
4428 ARM RISCix arm-*-* (as host)
4431 Configurations that have been declared obsolete will be commented out,
4432 but the code will be left in place. If there is no activity to revive
4433 these configurations before the next release of GDB, the sources will
4434 be permanently REMOVED.
4436 * Gould support removed
4438 Support for the Gould PowerNode and NP1 has been removed.
4440 * New features for SVR4
4442 On SVR4 native platforms (such as Solaris), if you attach to a process
4443 without first loading a symbol file, GDB will now attempt to locate and
4444 load symbols from the running process's executable file.
4446 * Many C++ enhancements
4448 C++ support has been greatly improved. Overload resolution now works properly
4449 in almost all cases. RTTI support is on the way.
4451 * Remote targets can connect to a sub-program
4453 A popen(3) style serial-device has been added. This device starts a
4454 sub-process (such as a stand-alone simulator) and then communicates
4455 with that. The sub-program to run is specified using the syntax
4456 ``|<program> <args>'' vis:
4458 (gdb) set remotedebug 1
4459 (gdb) target extended-remote |mn10300-elf-sim program-args
4461 * MIPS 64 remote protocol
4463 A long standing bug in the mips64 remote protocol where by GDB
4464 expected certain 32 bit registers (ex SR) to be transfered as 32
4465 instead of 64 bits has been fixed.
4467 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4468 added to provide backward compatibility with older versions of GDB.
4470 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4472 The command ``set remotebinarydownload'' command has been replaced by
4473 ``set remote X-packet''. Other commands in ``set remote'' family
4474 include ``set remote P-packet''.
4476 * Breakpoint commands accept ranges.
4478 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4479 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4480 ``tracepoint passcount'' also accepts a range of tracepoints.
4482 * ``apropos'' command added.
4484 The ``apropos'' command searches through command names and
4485 documentation strings, printing out matches, making it much easier to
4486 try to find a command that does what you are looking for.
4490 A new machine oriented interface (MI) has been added to GDB. This
4491 interface is designed for debug environments running GDB as a separate
4492 process. This is part of the long term libGDB project. See the
4493 "GDB/MI" chapter of the GDB manual for further information. It can be
4494 enabled by configuring with:
4496 .../configure --enable-gdbmi
4498 *** Changes in GDB-4.18:
4500 * New native configurations
4502 HP-UX 10.20 hppa*-*-hpux10.20
4503 HP-UX 11.x hppa*-*-hpux11.0*
4504 M68K GNU/Linux m68*-*-linux*
4508 Fujitsu FR30 fr30-*-elf*
4509 Intel StrongARM strongarm-*-*
4510 Mitsubishi D30V d30v-*-*
4512 * OBSOLETE configurations
4514 Gould PowerNode, NP1 np1-*-*, pn-*-*
4516 Configurations that have been declared obsolete will be commented out,
4517 but the code will be left in place. If there is no activity to revive
4518 these configurations before the next release of GDB, the sources will
4519 be permanently REMOVED.
4523 As a compatibility experiment, GDB's source files buildsym.h and
4524 buildsym.c have been converted to pure standard C, no longer
4525 containing any K&R compatibility code. We believe that all systems in
4526 use today either come with a standard C compiler, or have a GCC port
4527 available. If this is not true, please report the affected
4528 configuration to bug-gdb@gnu.org immediately. See the README file for
4529 information about getting a standard C compiler if you don't have one
4534 GDB now uses readline 2.2.
4536 * set extension-language
4538 You can now control the mapping between filename extensions and source
4539 languages by using the `set extension-language' command. For instance,
4540 you can ask GDB to treat .c files as C++ by saying
4541 set extension-language .c c++
4542 The command `info extensions' lists all of the recognized extensions
4543 and their associated languages.
4545 * Setting processor type for PowerPC and RS/6000
4547 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4548 you can use the `set processor' command to specify what variant of the
4549 PowerPC family you are debugging. The command
4553 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4554 following PowerPC and RS6000 variants:
4556 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4557 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4559 403GC IBM PowerPC 403GC
4560 505 Motorola PowerPC 505
4561 860 Motorola PowerPC 860 or 850
4562 601 Motorola PowerPC 601
4563 602 Motorola PowerPC 602
4564 603 Motorola/IBM PowerPC 603 or 603e
4565 604 Motorola PowerPC 604 or 604e
4566 750 Motorola/IBM PowerPC 750 or 750
4568 At the moment, this command just tells GDB what to name the
4569 special-purpose processor registers. Since almost all the affected
4570 registers are inaccessible to user-level programs, this command is
4571 only useful for remote debugging in its present form.
4575 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4576 more extensive support for HP-UX. Added features include shared
4577 library support, kernel threads and hardware watchpoints for 11.00,
4578 support for HP's ANSI C and C++ compilers, and a compatibility mode
4579 for xdb and dbx commands.
4583 HP's donation includes the new concept of catchpoints, which is a
4584 generalization of the old catch command. On HP-UX, it is now possible
4585 to catch exec, fork, and vfork, as well as library loading.
4587 This means that the existing catch command has changed; its first
4588 argument now specifies the type of catch to be set up. See the
4589 output of "help catch" for a list of catchpoint types.
4591 * Debugging across forks
4593 On HP-UX, you can choose which process to debug when a fork() happens
4598 HP has donated a curses-based terminal user interface (TUI). To get
4599 it, build with --enable-tui. Although this can be enabled for any
4600 configuration, at present it only works for native HP debugging.
4602 * GDB remote protocol additions
4604 A new protocol packet 'X' that writes binary data is now available.
4605 Default behavior is to try 'X', then drop back to 'M' if the stub
4606 fails to respond. The settable variable `remotebinarydownload'
4607 allows explicit control over the use of 'X'.
4609 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4610 full 64-bit address. The command
4612 set remoteaddresssize 32
4614 can be used to revert to the old behaviour. For existing remote stubs
4615 the change should not be noticed, as the additional address information
4618 In order to assist in debugging stubs, you may use the maintenance
4619 command `packet' to send any text string to the stub. For instance,
4621 maint packet heythere
4623 sends the packet "$heythere#<checksum>". Note that it is very easy to
4624 disrupt a debugging session by sending the wrong packet at the wrong
4627 The compare-sections command allows you to compare section data on the
4628 target to what is in the executable file without uploading or
4629 downloading, by comparing CRC checksums.
4631 * Tracing can collect general expressions
4633 You may now collect general expressions at tracepoints. This requires
4634 further additions to the target-side stub; see tracepoint.c and
4635 doc/agentexpr.texi for further details.
4637 * mask-address variable for Mips
4639 For Mips targets, you may control the zeroing of the upper 32 bits of
4640 a 64-bit address by entering `set mask-address on'. This is mainly
4641 of interest to users of embedded R4xxx and R5xxx processors.
4643 * Higher serial baud rates
4645 GDB's serial code now allows you to specify baud rates 57600, 115200,
4646 230400, and 460800 baud. (Note that your host system may not be able
4647 to achieve all of these rates.)
4651 The i960 configuration now includes an initial implementation of a
4652 builtin simulator, contributed by Jim Wilson.
4655 *** Changes in GDB-4.17:
4657 * New native configurations
4659 Alpha GNU/Linux alpha*-*-linux*
4660 Unixware 2.x i[3456]86-unixware2*
4661 Irix 6.x mips*-sgi-irix6*
4662 PowerPC GNU/Linux powerpc-*-linux*
4663 PowerPC Solaris powerpcle-*-solaris*
4664 Sparc GNU/Linux sparc-*-linux*
4665 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4669 Argonaut Risc Chip (ARC) arc-*-*
4670 Hitachi H8/300S h8300*-*-*
4671 Matsushita MN10200 w/simulator mn10200-*-*
4672 Matsushita MN10300 w/simulator mn10300-*-*
4673 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4674 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4675 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4676 Mitsubishi D10V w/simulator d10v-*-*
4677 Mitsubishi M32R/D w/simulator m32r-*-elf*
4678 Tsqware Sparclet sparclet-*-*
4679 NEC V850 w/simulator v850-*-*
4681 * New debugging protocols
4683 ARM with RDI protocol arm*-*-*
4684 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4685 DDB and LSI variants of PMON protocol mips*-*-*
4686 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4687 PowerPC with SDS protocol powerpc{,le}-*-eabi
4688 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4692 All configurations can now understand and use the DWARF 2 debugging
4693 format. The choice is automatic, if the symbol file contains DWARF 2
4698 GDB now includes basic Java language support. This support is
4699 only useful with Java compilers that produce native machine code.
4701 * solib-absolute-prefix and solib-search-path
4703 For SunOS and SVR4 shared libraries, you may now set the prefix for
4704 loading absolute shared library symbol files, and the search path for
4705 locating non-absolute shared library symbol files.
4707 * Live range splitting
4709 GDB can now effectively debug code for which GCC has performed live
4710 range splitting as part of its optimization. See gdb/doc/LRS for
4711 more details on the expected format of the stabs information.
4715 GDB's support for the GNU Hurd, including thread debugging, has been
4716 updated to work with current versions of the Hurd.
4720 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4721 instruction set. ARM GDB automatically detects when Thumb
4722 instructions are in use, and adjusts disassembly and backtracing
4727 GDB's MIPS target configurations now handle the MIP16 16-bit
4732 GDB now includes support for overlays; if an executable has been
4733 linked such that multiple sections are based at the same address, GDB
4734 will decide which section to use for symbolic info. You can choose to
4735 control the decision manually, using overlay commands, or implement
4736 additional target-side support and use "overlay load-target" to bring
4737 in the overlay mapping. Do "help overlay" for more detail.
4741 The command "info symbol <address>" displays information about
4742 the symbol at the specified address.
4746 The standard remote protocol now includes an extension that allows
4747 asynchronous collection and display of trace data. This requires
4748 extensive support in the target-side debugging stub. Tracing mode
4749 includes a new interaction mode in GDB and new commands: see the
4750 file tracepoint.c for more details.
4754 Configurations for embedded MIPS now include a simulator contributed
4755 by Cygnus Solutions. The simulator supports the instruction sets
4756 of most MIPS variants.
4760 Sparc configurations may now include the ERC32 simulator contributed
4761 by the European Space Agency. The simulator is not built into
4762 Sparc targets by default; configure with --enable-sim to include it.
4766 For target configurations that may include multiple variants of a
4767 basic architecture (such as MIPS and SH), you may now set the
4768 architecture explicitly. "set arch" sets, "info arch" lists
4769 the possible architectures.
4771 *** Changes in GDB-4.16:
4773 * New native configurations
4775 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4776 M68K NetBSD m68k-*-netbsd*
4777 PowerPC AIX 4.x powerpc-*-aix*
4778 PowerPC MacOS powerpc-*-macos*
4779 PowerPC Windows NT powerpcle-*-cygwin32
4780 RS/6000 AIX 4.x rs6000-*-aix4*
4784 ARM with RDP protocol arm-*-*
4785 I960 with MON960 i960-*-coff
4786 MIPS VxWorks mips*-*-vxworks*
4787 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4788 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4790 Matra Sparclet sparclet-*-*
4794 The powerpc-eabi configuration now includes the PSIM simulator,
4795 contributed by Andrew Cagney, with assistance from Mike Meissner.
4796 PSIM is a very elaborate model of the PowerPC, including not only
4797 basic instruction set execution, but also details of execution unit
4798 performance and I/O hardware. See sim/ppc/README for more details.
4802 GDB now works with Solaris 2.5.
4804 * Windows 95/NT native
4806 GDB will now work as a native debugger on Windows 95 and Windows NT.
4807 To build it from source, you must use the "gnu-win32" environment,
4808 which uses a DLL to emulate enough of Unix to run the GNU tools.
4809 Further information, binaries, and sources are available at
4810 ftp.cygnus.com, under pub/gnu-win32.
4812 * dont-repeat command
4814 If a user-defined command includes the command `dont-repeat', then the
4815 command will not be repeated if the user just types return. This is
4816 useful if the command is time-consuming to run, so that accidental
4817 extra keystrokes don't run the same command many times.
4819 * Send break instead of ^C
4821 The standard remote protocol now includes an option to send a break
4822 rather than a ^C to the target in order to interrupt it. By default,
4823 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4825 * Remote protocol timeout
4827 The standard remote protocol includes a new variable `remotetimeout'
4828 that allows you to set the number of seconds before GDB gives up trying
4829 to read from the target. The default value is 2.
4831 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4833 By default GDB will automatically keep track of objects as they are
4834 loaded and unloaded by the dynamic linker. By using the command `set
4835 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4836 when shared library events occur, thus allowing you to set breakpoints
4837 in shared libraries which are explicitly loaded by the inferior.
4839 Note this feature does not work on hpux8. On hpux9 you must link
4840 /usr/lib/end.o into your program. This feature should work
4841 automatically on hpux10.
4843 * Irix 5.x hardware watchpoint support
4845 Irix 5 configurations now support the use of hardware watchpoints.
4847 * Mips protocol "SYN garbage limit"
4849 When debugging a Mips target using the `target mips' protocol, you
4850 may set the number of characters that GDB will ignore by setting
4851 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4852 every character. The default value is 1050.
4854 * Recording and replaying remote debug sessions
4856 If you set `remotelogfile' to the name of a file, gdb will write to it
4857 a recording of a remote debug session. This recording may then be
4858 replayed back to gdb using "gdbreplay". See gdbserver/README for
4859 details. This is useful when you have a problem with GDB while doing
4860 remote debugging; you can make a recording of the session and send it
4861 to someone else, who can then recreate the problem.
4863 * Speedups for remote debugging
4865 GDB includes speedups for downloading and stepping MIPS systems using
4866 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4867 and more efficient S-record downloading.
4869 * Memory use reductions and statistics collection
4871 GDB now uses less memory and reports statistics about memory usage.
4872 Try the `maint print statistics' command, for example.
4874 *** Changes in GDB-4.15:
4876 * Psymtabs for XCOFF
4878 The symbol reader for AIX GDB now uses partial symbol tables. This
4879 can greatly improve startup time, especially for large executables.
4881 * Remote targets use caching
4883 Remote targets now use a data cache to speed up communication with the
4884 remote side. The data cache could lead to incorrect results because
4885 it doesn't know about volatile variables, thus making it impossible to
4886 debug targets which use memory mapped I/O devices. `set remotecache
4887 off' turns the the data cache off.
4889 * Remote targets may have threads
4891 The standard remote protocol now includes support for multiple threads
4892 in the target system, using new protocol commands 'H' and 'T'. See
4893 gdb/remote.c for details.
4897 If GDB is configured with `--enable-netrom', then it will include
4898 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4899 acts as though it is a bank of ROM on the target board, but you can
4900 write into it over the network. GDB's support consists only of
4901 support for fast loading into the emulated ROM; to debug, you must use
4902 another protocol, such as standard remote protocol. The usual
4903 sequence is something like
4905 target nrom <netrom-hostname>
4907 target remote <netrom-hostname>:1235
4911 GDB now includes support for the Apple Macintosh, as a host only. It
4912 may be run as either an MPW tool or as a standalone application, and
4913 it can debug through the serial port. All the usual GDB commands are
4914 available, but to the target command, you must supply "serial" as the
4915 device type instead of "/dev/ttyXX". See mpw-README in the main
4916 directory for more information on how to build. The MPW configuration
4917 scripts */mpw-config.in support only a few targets, and only the
4918 mips-idt-ecoff target has been tested.
4922 GDB configuration now uses autoconf. This is not user-visible,
4923 but does simplify configuration and building.
4927 GDB now supports hpux10.
4929 *** Changes in GDB-4.14:
4931 * New native configurations
4933 x86 FreeBSD i[345]86-*-freebsd
4934 x86 NetBSD i[345]86-*-netbsd
4935 NS32k NetBSD ns32k-*-netbsd
4936 Sparc NetBSD sparc-*-netbsd
4940 A29K VxWorks a29k-*-vxworks
4941 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4942 CPU32 EST-300 emulator m68*-*-est*
4943 PowerPC ELF powerpc-*-elf
4946 * Alpha OSF/1 support for procfs
4948 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4949 possible to attach to running processes. As the mounting of the /proc
4950 filesystem is optional on the Alpha, GDB automatically determines
4951 the availability of /proc during startup. This can lead to problems
4952 if /proc is unmounted after GDB has been started.
4954 * Arguments to user-defined commands
4956 User commands may accept up to 10 arguments separated by whitespace.
4957 Arguments are accessed within the user command via $arg0..$arg9. A
4960 print $arg0 + $arg1 + $arg2
4962 To execute the command use:
4965 Defines the command "adder" which prints the sum of its three arguments.
4966 Note the arguments are text substitutions, so they may reference variables,
4967 use complex expressions, or even perform inferior function calls.
4969 * New `if' and `while' commands
4971 This makes it possible to write more sophisticated user-defined
4972 commands. Both commands take a single argument, which is the
4973 expression to evaluate, and must be followed by the commands to
4974 execute, one per line, if the expression is nonzero, the list being
4975 terminated by the word `end'. The `if' command list may include an
4976 `else' word, which causes the following commands to be executed only
4977 if the expression is zero.
4979 * Fortran source language mode
4981 GDB now includes partial support for Fortran 77. It will recognize
4982 Fortran programs and can evaluate a subset of Fortran expressions, but
4983 variables and functions may not be handled correctly. GDB will work
4984 with G77, but does not yet know much about symbols emitted by other
4987 * Better HPUX support
4989 Most debugging facilities now work on dynamic executables for HPPAs
4990 running hpux9 or later. You can attach to running dynamically linked
4991 processes, but by default the dynamic libraries will be read-only, so
4992 for instance you won't be able to put breakpoints in them. To change
4993 that behavior do the following before running the program:
4999 This will cause the libraries to be mapped private and read-write.
5000 To revert to the normal behavior, do this:
5006 You cannot set breakpoints or examine data in the library until after
5007 the library is loaded if the function/data symbols do not have
5010 GDB can now also read debug symbols produced by the HP C compiler on
5011 HPPAs (sorry, no C++, Fortran or 68k support).
5013 * Target byte order now dynamically selectable
5015 You can choose which byte order to use with a target system, via the
5016 commands "set endian big" and "set endian little", and you can see the
5017 current setting by using "show endian". You can also give the command
5018 "set endian auto", in which case GDB will use the byte order
5019 associated with the executable. Currently, only embedded MIPS
5020 configurations support dynamic selection of target byte order.
5022 * New DOS host serial code
5024 This version uses DPMI interrupts to handle buffered I/O, so you
5025 no longer need to run asynctsr when debugging boards connected to
5028 *** Changes in GDB-4.13:
5030 * New "complete" command
5032 This lists all the possible completions for the rest of the line, if it
5033 were to be given as a command itself. This is intended for use by emacs.
5035 * Trailing space optional in prompt
5037 "set prompt" no longer adds a space for you after the prompt you set. This
5038 allows you to set a prompt which ends in a space or one that does not.
5040 * Breakpoint hit counts
5042 "info break" now displays a count of the number of times the breakpoint
5043 has been hit. This is especially useful in conjunction with "ignore"; you
5044 can ignore a large number of breakpoint hits, look at the breakpoint info
5045 to see how many times the breakpoint was hit, then run again, ignoring one
5046 less than that number, and this will get you quickly to the last hit of
5049 * Ability to stop printing at NULL character
5051 "set print null-stop" will cause GDB to stop printing the characters of
5052 an array when the first NULL is encountered. This is useful when large
5053 arrays actually contain only short strings.
5055 * Shared library breakpoints
5057 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5058 breakpoints in shared libraries before the executable is run.
5060 * Hardware watchpoints
5062 There is a new hardware breakpoint for the watch command for sparclite
5063 targets. See gdb/sparclite/hw_breakpoint.note.
5065 Hardware watchpoints are also now supported under GNU/Linux.
5069 Annotations have been added. These are for use with graphical interfaces,
5070 and are still experimental. Currently only gdba.el uses these.
5072 * Improved Irix 5 support
5074 GDB now works properly with Irix 5.2.
5076 * Improved HPPA support
5078 GDB now works properly with the latest GCC and GAS.
5080 * New native configurations
5082 Sequent PTX4 i[34]86-sequent-ptx4
5083 HPPA running OSF/1 hppa*-*-osf*
5084 Atari TT running SVR4 m68*-*-sysv4*
5085 RS/6000 LynxOS rs6000-*-lynxos*
5089 OS/9000 i[34]86-*-os9k
5090 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5093 * Hitachi SH7000 and E7000-PC ICE support
5095 There is now support for communicating with the Hitachi E7000-PC ICE.
5096 This is available automatically when GDB is configured for the SH.
5100 As usual, a variety of small fixes and improvements, both generic
5101 and configuration-specific. See the ChangeLog for more detail.
5103 *** Changes in GDB-4.12:
5105 * Irix 5 is now supported
5109 GDB-4.12 on the HPPA has a number of changes which make it unable
5110 to debug the output from the currently released versions of GCC and
5111 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5112 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5113 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5116 *** Changes in GDB-4.11:
5118 * User visible changes:
5122 The "set remotedebug" option is now consistent between the mips remote
5123 target, remote targets using the gdb-specific protocol, UDI (AMD's
5124 debug protocol for the 29k) and the 88k bug monitor. It is now an
5125 integer specifying a debug level (normally 0 or 1, but 2 means more
5126 debugging info for the mips target).
5128 * DEC Alpha native support
5130 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5131 debug info, but GDB works fairly well with the DEC compiler and should
5132 work with a future GCC release. See the README file for a few
5133 Alpha-specific notes.
5135 * Preliminary thread implementation
5137 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5139 * LynxOS native and target support for 386
5141 This release has been hosted on LynxOS 2.2, and also can be configured
5142 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5145 * Improvements in C++ mangling/demangling.
5147 This release has much better g++ debugging, specifically in name
5148 mangling/demangling, virtual function calls, print virtual table,
5149 call methods, ...etc.
5151 *** Changes in GDB-4.10:
5153 * User visible changes:
5155 Remote debugging using the GDB-specific (`target remote') protocol now
5156 supports the `load' command. This is only useful if you have some
5157 other way of getting the stub to the target system, and you can put it
5158 somewhere in memory where it won't get clobbered by the download.
5160 Filename completion now works.
5162 When run under emacs mode, the "info line" command now causes the
5163 arrow to point to the line specified. Also, "info line" prints
5164 addresses in symbolic form (as well as hex).
5166 All vxworks based targets now support a user settable option, called
5167 vxworks-timeout. This option represents the number of seconds gdb
5168 should wait for responses to rpc's. You might want to use this if
5169 your vxworks target is, perhaps, a slow software simulator or happens
5170 to be on the far side of a thin network line.
5174 This release contains support for using a DEC alpha as a GDB host for
5175 cross debugging. Native alpha debugging is not supported yet.
5178 *** Changes in GDB-4.9:
5182 This is the first GDB release which is accompanied by a matching testsuite.
5183 The testsuite requires installation of dejagnu, which should be available
5184 via ftp from most sites that carry GNU software.
5188 'Cfront' style demangling has had its name changed to 'ARM' style, to
5189 emphasize that it was written from the specifications in the C++ Annotated
5190 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5191 disclaimers, it still generated too much confusion with users attempting to
5192 use gdb with AT&T cfront.
5196 GDB now uses a standard remote interface to a simulator library.
5197 So far, the library contains simulators for the Zilog Z8001/2, the
5198 Hitachi H8/300, H8/500 and Super-H.
5200 * New targets supported
5202 H8/300 simulator h8300-hitachi-hms or h8300hms
5203 H8/500 simulator h8500-hitachi-hms or h8500hms
5204 SH simulator sh-hitachi-hms or sh
5205 Z8000 simulator z8k-zilog-none or z8ksim
5206 IDT MIPS board over serial line mips-idt-ecoff
5208 Cross-debugging to GO32 targets is supported. It requires a custom
5209 version of the i386-stub.c module which is integrated with the
5210 GO32 memory extender.
5212 * New remote protocols
5214 MIPS remote debugging protocol.
5216 * New source languages supported
5218 This version includes preliminary support for Chill, a Pascal like language
5219 used by telecommunications companies. Chill support is also being integrated
5220 into the GNU compiler, but we don't know when it will be publically available.
5223 *** Changes in GDB-4.8:
5225 * HP Precision Architecture supported
5227 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5228 version of this support was available as a set of patches from the
5229 University of Utah. GDB does not support debugging of programs
5230 compiled with the HP compiler, because HP will not document their file
5231 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5232 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5234 Many problems in the preliminary version have been fixed.
5236 * Faster and better demangling
5238 We have improved template demangling and fixed numerous bugs in the GNU style
5239 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5240 character types (wchar_t) are now supported. Demangling of each symbol is now
5241 only done once, and is cached when the symbol table for a file is read in.
5242 This results in a small increase in memory usage for C programs, a moderate
5243 increase in memory usage for C++ programs, and a fantastic speedup in
5246 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5247 from the specifications in the Annotated Reference Manual, which AT&T's
5248 compiler does not actually implement.
5250 * G++ multiple inheritance compiler problem
5252 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5253 inheritance lattices was reworked to properly discover ambiguities. We
5254 recently found an example which causes this new algorithm to fail in a
5255 very subtle way, producing bad debug information for those classes.
5256 The file 'gcc.patch' (in this directory) can be applied to gcc to
5257 circumvent the problem. A future GCC release will contain a complete
5260 The previous G++ debug info problem (mentioned below for the gdb-4.7
5261 release) is fixed in gcc version 2.3.2.
5263 * Improved configure script
5265 The `configure' script will now attempt to guess your system type if
5266 you don't supply a host system type. The old scheme of supplying a
5267 host system triplet is preferable over using this. All the magic is
5268 done in the new `config.guess' script. Examine it for details.
5270 We have also brought our configure script much more in line with the FSF's
5271 version. It now supports the --with-xxx options. In particular,
5272 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5273 The resulting GDB will not be able to read arbitrary object file formats --
5274 only the format ``expected'' to be used on the configured target system.
5275 We hope to make this the default in a future release.
5277 * Documentation improvements
5279 There's new internal documentation on how to modify GDB, and how to
5280 produce clean changes to the code. We implore people to read it
5281 before submitting changes.
5283 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5284 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5285 `info' files are also provided. To build `info' files from scratch,
5286 you will need the latest `makeinfo' release, which will be available in
5287 a future texinfo-X.Y release.
5289 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5290 We're not sure exactly which versions have this problem, but it has
5291 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5292 or better. If that isn't possible, there is a patch in
5293 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5294 around this problem.
5298 GDB now supports array constants that can be used in expressions typed in by
5299 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5300 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5303 The new directory `gdb/sparclite' contains a program that demonstrates
5304 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5306 * New native hosts supported
5308 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5309 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5311 * New targets supported
5313 AMD 29k family via UDI a29k-amd-udi or udi29k
5315 * New file formats supported
5317 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5318 HPUX core files, and SCO 3.2v2 core files.
5322 Attaching to processes now works again; thanks for the many bug reports.
5324 We have also stomped on a bunch of core dumps caused by
5325 printf_filtered("%s") problems.
5327 We eliminated a copyright problem on the rpc and ptrace header files
5328 for VxWorks, which was discovered at the last minute during the 4.7
5329 release. You should now be able to build a VxWorks GDB.
5331 You can now interrupt gdb while an attached process is running. This
5332 will cause the attached process to stop, and give control back to GDB.
5334 We fixed problems caused by using too many file descriptors
5335 for reading symbols from object files and libraries. This was
5336 especially a problem for programs that used many (~100) shared
5339 The `step' command now only enters a subroutine if there is line number
5340 information for the subroutine. Otherwise it acts like the `next'
5341 command. Previously, `step' would enter subroutines if there was
5342 any debugging information about the routine. This avoids problems
5343 when using `cc -g1' on MIPS machines.
5345 * Internal improvements
5347 GDB's internal interfaces have been improved to make it easier to support
5348 debugging of multiple languages in the future.
5350 GDB now uses a common structure for symbol information internally.
5351 Minimal symbols (derived from linkage symbols in object files), partial
5352 symbols (from a quick scan of debug information), and full symbols
5353 contain a common subset of information, making it easier to write
5354 shared code that handles any of them.
5356 * New command line options
5358 We now accept --silent as an alias for --quiet.
5362 The memory-mapped-malloc library is now licensed under the GNU Library
5363 General Public License.
5365 *** Changes in GDB-4.7:
5367 * Host/native/target split
5369 GDB has had some major internal surgery to untangle the support for
5370 hosts and remote targets. Now, when you configure GDB for a remote
5371 target, it will no longer load in all of the support for debugging
5372 local programs on the host. When fully completed and tested, this will
5373 ensure that arbitrary host/target combinations are possible.
5375 The primary conceptual shift is to separate the non-portable code in
5376 GDB into three categories. Host specific code is required any time GDB
5377 is compiled on that host, regardless of the target. Target specific
5378 code relates to the peculiarities of the target, but can be compiled on
5379 any host. Native specific code is everything else: it can only be
5380 built when the host and target are the same system. Child process
5381 handling and core file support are two common `native' examples.
5383 GDB's use of /proc for controlling Unix child processes is now cleaner.
5384 It has been split out into a single module under the `target_ops' vector,
5385 plus two native-dependent functions for each system that uses /proc.
5387 * New hosts supported
5389 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5390 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5391 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5393 * New targets supported
5395 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5396 68030 and CPU32 m68030-*-*, m68332-*-*
5398 * New native hosts supported
5400 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5401 (386bsd is not well tested yet)
5402 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5404 * New file formats supported
5406 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5407 supports reading of `a.out.adobe' object files, which are an a.out
5408 format extended with minimal information about multiple sections.
5412 `show copying' is the same as the old `info copying'.
5413 `show warranty' is the same as `info warrantee'.
5414 These were renamed for consistency. The old commands continue to work.
5416 `info handle' is a new alias for `info signals'.
5418 You can now define pre-command hooks, which attach arbitrary command
5419 scripts to any command. The commands in the hook will be executed
5420 prior to the user's command. You can also create a hook which will be
5421 executed whenever the program stops. See gdb.texinfo.
5425 We now deal with Cfront style name mangling, and can even extract type
5426 info from mangled symbols. GDB can automatically figure out which
5427 symbol mangling style your C++ compiler uses.
5429 Calling of methods and virtual functions has been improved as well.
5433 The crash that occured when debugging Sun Ansi-C compiled binaries is
5434 fixed. This was due to mishandling of the extra N_SO stabs output
5437 We also finally got Ultrix 4.2 running in house, and fixed core file
5438 support, with help from a dozen people on the net.
5440 John M. Farrell discovered that the reason that single-stepping was so
5441 slow on all of the Mips based platforms (primarily SGI and DEC) was
5442 that we were trying to demangle and lookup a symbol used for internal
5443 purposes on every instruction that was being stepped through. Changing
5444 the name of that symbol so that it couldn't be mistaken for a C++
5445 mangled symbol sped things up a great deal.
5447 Rich Pixley sped up symbol lookups in general by getting much smarter
5448 about when C++ symbol mangling is necessary. This should make symbol
5449 completion (TAB on the command line) much faster. It's not as fast as
5450 we'd like, but it's significantly faster than gdb-4.6.
5454 A new user controllable variable 'call_scratch_address' can
5455 specify the location of a scratch area to be used when GDB
5456 calls a function in the target. This is necessary because the
5457 usual method of putting the scratch area on the stack does not work
5458 in systems that have separate instruction and data spaces.
5460 We integrated changes to support the 29k UDI (Universal Debugger
5461 Interface), but discovered at the last minute that we didn't have all
5462 of the appropriate copyright paperwork. We are working with AMD to
5463 resolve this, and hope to have it available soon.
5467 We have sped up the remote serial line protocol, especially for targets
5468 with lots of registers. It now supports a new `expedited status' ('T')
5469 message which can be used in place of the existing 'S' status message.
5470 This allows the remote stub to send only the registers that GDB
5471 needs to make a quick decision about single-stepping or conditional
5472 breakpoints, eliminating the need to fetch the entire register set for
5473 each instruction being stepped through.
5475 The GDB remote serial protocol now implements a write-through cache for
5476 registers, only re-reading the registers if the target has run.
5478 There is also a new remote serial stub for SPARC processors. You can
5479 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5480 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5481 processor with a serial port.
5485 Configure.in files have become much easier to read and modify. A new
5486 `table driven' format makes it more obvious what configurations are
5487 supported, and what files each one uses.
5491 There is a new opcodes library which will eventually contain all of the
5492 disassembly routines and opcode tables. At present, it only contains
5493 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5494 disassembler (binutils/objdump) to share these routines.
5496 The libiberty library is now copylefted under the GNU Library General
5497 Public License. This allows more liberal use, and was done so libg++
5498 can use it. This makes no difference to GDB, since the Library License
5499 grants all the rights from the General Public License.
5503 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5504 reference to the stabs symbol info used by the debugger. It is (as far
5505 as we know) the only published document on this fascinating topic. We
5506 encourage you to read it, compare it to the stabs information on your
5507 system, and send improvements on the document in general (to
5508 bug-gdb@prep.ai.mit.edu).
5510 And, of course, many bugs have been fixed.
5513 *** Changes in GDB-4.6:
5515 * Better support for C++ function names
5517 GDB now accepts as input the "demangled form" of C++ overloaded function
5518 names and member function names, and can do command completion on such names
5519 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5520 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5521 Make use of command completion, it is your friend.
5523 GDB also now accepts a variety of C++ mangled symbol formats. They are
5524 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5525 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5526 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5527 for the list of formats.
5529 * G++ symbol mangling problem
5531 Recent versions of gcc have a bug in how they emit debugging information for
5532 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5533 directory) can be applied to gcc to fix the problem. Alternatively, if you
5534 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5535 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5536 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5539 * New 'maintenance' command
5541 All of the commands related to hacking GDB internals have been moved out of
5542 the main command set, and now live behind the 'maintenance' command. This
5543 can also be abbreviated as 'mt'. The following changes were made:
5545 dump-me -> maintenance dump-me
5546 info all-breakpoints -> maintenance info breakpoints
5547 printmsyms -> maintenance print msyms
5548 printobjfiles -> maintenance print objfiles
5549 printpsyms -> maintenance print psymbols
5550 printsyms -> maintenance print symbols
5552 The following commands are new:
5554 maintenance demangle Call internal GDB demangler routine to
5555 demangle a C++ link name and prints the result.
5556 maintenance print type Print a type chain for a given symbol
5558 * Change to .gdbinit file processing
5560 We now read the $HOME/.gdbinit file before processing the argv arguments
5561 (e.g. reading symbol files or core files). This allows global parameters to
5562 be set, which will apply during the symbol reading. The ./.gdbinit is still
5563 read after argv processing.
5565 * New hosts supported
5567 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5569 GNU/Linux support i386-unknown-linux or linux
5571 We are also including code to support the HP/PA running BSD and HPUX. This
5572 is almost guaranteed not to work, as we didn't have time to test or build it
5573 for this release. We are including it so that the more adventurous (or
5574 masochistic) of you can play with it. We also had major problems with the
5575 fact that the compiler that we got from HP doesn't support the -g option.
5578 * New targets supported
5580 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5582 * More smarts about finding #include files
5584 GDB now remembers the compilation directory for all include files, and for
5585 all files from which C is generated (like yacc and lex sources). This
5586 greatly improves GDB's ability to find yacc/lex sources, and include files,
5587 especially if you are debugging your program from a directory different from
5588 the one that contains your sources.
5590 We also fixed a bug which caused difficulty with listing and setting
5591 breakpoints in include files which contain C code. (In the past, you had to
5592 try twice in order to list an include file that you hadn't looked at before.)
5594 * Interesting infernals change
5596 GDB now deals with arbitrary numbers of sections, where the symbols for each
5597 section must be relocated relative to that section's landing place in the
5598 target's address space. This work was needed to support ELF with embedded
5599 stabs used by Solaris-2.0.
5601 * Bug fixes (of course!)
5603 There have been loads of fixes for the following things:
5604 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5605 i960, stabs, DOS(GO32), procfs, etc...
5607 See the ChangeLog for details.
5609 *** Changes in GDB-4.5:
5611 * New machines supported (host and target)
5613 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5615 SGI Irix-4.x mips-sgi-irix4 or iris4
5617 * New malloc package
5619 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5620 Mmalloc is capable of handling mutiple heaps of memory. It is also
5621 capable of saving a heap to a file, and then mapping it back in later.
5622 This can be used to greatly speedup the startup of GDB by using a
5623 pre-parsed symbol table which lives in a mmalloc managed heap. For
5624 more details, please read mmalloc/mmalloc.texi.
5628 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5629 'help info proc' for details.
5631 * MIPS ecoff symbol table format
5633 The code that reads MIPS symbol table format is now supported on all hosts.
5634 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5637 * File name changes for MS-DOS
5639 Many files in the config directories have been renamed to make it easier to
5640 support GDB on MS-DOSe systems (which have very restrictive file name
5641 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5642 environment) is close to working but has some remaining problems. Note
5643 that debugging of DOS programs is not supported, due to limitations
5644 in the ``operating system'', but it can be used to host cross-debugging.
5646 * Cross byte order fixes
5648 Many fixes have been made to support cross debugging of Sparc and MIPS
5649 targets from hosts whose byte order differs.
5651 * New -mapped and -readnow options
5653 If memory-mapped files are available on your system through the 'mmap'
5654 system call, you can use the -mapped option on the `file' or
5655 `symbol-file' commands to cause GDB to write the symbols from your
5656 program into a reusable file. If the program you are debugging is
5657 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5658 Future GDB debugging sessions will notice the presence of this file,
5659 and will quickly map in symbol information from it, rather than reading
5660 the symbol table from the executable program. Using the '-mapped'
5661 option in a GDB `file' or `symbol-file' command has the same effect as
5662 starting GDB with the '-mapped' command-line option.
5664 You can cause GDB to read the entire symbol table immediately by using
5665 the '-readnow' option with any of the commands that load symbol table
5666 information (or on the GDB command line). This makes the command
5667 slower, but makes future operations faster.
5669 The -mapped and -readnow options are typically combined in order to
5670 build a `fred.syms' file that contains complete symbol information.
5671 A simple GDB invocation to do nothing but build a `.syms' file for future
5674 gdb -batch -nx -mapped -readnow programname
5676 The `.syms' file is specific to the host machine on which GDB is run.
5677 It holds an exact image of GDB's internal symbol table. It cannot be
5678 shared across multiple host platforms.
5680 * longjmp() handling
5682 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5683 siglongjmp() without losing control. This feature has not yet been ported to
5684 all systems. It currently works on many 386 platforms, all MIPS-based
5685 platforms (SGI, DECstation, etc), and Sun3/4.
5689 Preliminary work has been put in to support the new Solaris OS from Sun. At
5690 this time, it can control and debug processes, but it is not capable of
5695 As always, many many bug fixes. The major areas were with g++, and mipsread.
5696 People using the MIPS-based platforms should experience fewer mysterious
5697 crashes and trashed symbol tables.
5699 *** Changes in GDB-4.4:
5701 * New machines supported (host and target)
5703 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5705 BSD Reno on Vax vax-dec-bsd
5706 Ultrix on Vax vax-dec-ultrix
5708 * New machines supported (target)
5710 AMD 29000 embedded, using EBMON a29k-none-none
5714 GDB continues to improve its handling of C++. `References' work better.
5715 The demangler has also been improved, and now deals with symbols mangled as
5716 per the Annotated C++ Reference Guide.
5718 GDB also now handles `stabs' symbol information embedded in MIPS
5719 `ecoff' symbol tables. Since the ecoff format was not easily
5720 extensible to handle new languages such as C++, this appeared to be a
5721 good way to put C++ debugging info into MIPS binaries. This option
5722 will be supported in the GNU C compiler, version 2, when it is
5725 * New features for SVR4
5727 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5728 shared libraries. Debugging dynamically linked programs should present
5729 only minor differences from debugging statically linked programs.
5731 The `info proc' command will print out information about any process
5732 on an SVR4 system (including the one you are debugging). At the moment,
5733 it prints the address mappings of the process.
5735 If you bring up GDB on another SVR4 system, please send mail to
5736 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5738 * Better dynamic linking support in SunOS
5740 Reading symbols from shared libraries which contain debugging symbols
5741 now works properly. However, there remain issues such as automatic
5742 skipping of `transfer vector' code during function calls, which
5743 make it harder to debug code in a shared library, than to debug the
5744 same code linked statically.
5748 GDB is now using the latest `getopt' routines from the FSF. This
5749 version accepts the -- prefix for options with long names. GDB will
5750 continue to accept the old forms (-option and +option) as well.
5751 Various single letter abbreviations for options have been explicity
5752 added to the option table so that they won't get overshadowed in the
5753 future by other options that begin with the same letter.
5757 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5758 Many assorted bugs have been handled. Many more remain to be handled.
5759 See the various ChangeLog files (primarily in gdb and bfd) for details.
5762 *** Changes in GDB-4.3:
5764 * New machines supported (host and target)
5766 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5767 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5768 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5770 * Almost SCO Unix support
5772 We had hoped to support:
5773 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5774 (except for core file support), but we discovered very late in the release
5775 that it has problems with process groups that render gdb unusable. Sorry
5776 about that. I encourage people to fix it and post the fixes.
5778 * Preliminary ELF and DWARF support
5780 GDB can read ELF object files on System V Release 4, and can handle
5781 debugging records for C, in DWARF format, in ELF files. This support
5782 is preliminary. If you bring up GDB on another SVR4 system, please
5783 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5788 GDB now uses the latest `readline' library. One user-visible change
5789 is that two tabs will list possible command completions, which previously
5790 required typing M-? (meta-question mark, or ESC ?).
5794 The `stepi' bug that many of you noticed has been squashed.
5795 Many bugs in C++ have been handled. Many more remain to be handled.
5796 See the various ChangeLog files (primarily in gdb and bfd) for details.
5798 * State of the MIPS world (in case you wondered):
5800 GDB can understand the symbol tables emitted by the compilers
5801 supplied by most vendors of MIPS-based machines, including DEC. These
5802 symbol tables are in a format that essentially nobody else uses.
5804 Some versions of gcc come with an assembler post-processor called
5805 mips-tfile. This program is required if you want to do source-level
5806 debugging of gcc-compiled programs. I believe FSF does not ship
5807 mips-tfile with gcc version 1, but it will eventually come with gcc
5810 Debugging of g++ output remains a problem. g++ version 1.xx does not
5811 really support it at all. (If you're lucky, you should be able to get
5812 line numbers and stack traces to work, but no parameters or local
5813 variables.) With some work it should be possible to improve the
5816 When gcc version 2 is released, you will have somewhat better luck.
5817 However, even then you will get confusing results for inheritance and
5820 We will eventually provide full debugging of g++ output on
5821 DECstations. This will probably involve some kind of stabs-in-ecoff
5822 encapulation, but the details have not been worked out yet.
5825 *** Changes in GDB-4.2:
5827 * Improved configuration
5829 Only one copy of `configure' exists now, and it is not self-modifying.
5830 Porting BFD is simpler.
5834 The `step' and `next' commands now only stop at the first instruction
5835 of a source line. This prevents the multiple stops that used to occur
5836 in switch statements, for-loops, etc. `Step' continues to stop if a
5837 function that has debugging information is called within the line.
5841 Lots of small bugs fixed. More remain.
5843 * New host supported (not target)
5845 Intel 386 PC clone running Mach i386-none-mach
5848 *** Changes in GDB-4.1:
5850 * Multiple source language support
5852 GDB now has internal scaffolding to handle several source languages.
5853 It determines the type of each source file from its filename extension,
5854 and will switch expression parsing and number formatting to match the
5855 language of the function in the currently selected stack frame.
5856 You can also specifically set the language to be used, with
5857 `set language c' or `set language modula-2'.
5861 GDB now has preliminary support for the GNU Modula-2 compiler,
5862 currently under development at the State University of New York at
5863 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5864 continue through the fall of 1991 and into 1992.
5866 Other Modula-2 compilers are currently not supported, and attempting to
5867 debug programs compiled with them will likely result in an error as the
5868 symbol table is read. Feel free to work on it, though!
5870 There are hooks in GDB for strict type checking and range checking,
5871 in the `Modula-2 philosophy', but they do not currently work.
5875 GDB can now write to executable and core files (e.g. patch
5876 a variable's value). You must turn this switch on, specify
5877 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5878 by assigning a new value to a variable. Modifications take
5881 * Automatic SunOS shared library reading
5883 When you run your program, GDB automatically determines where its
5884 shared libraries (if any) have been loaded, and reads their symbols.
5885 The `share' command is no longer needed. This also works when
5886 examining core files.
5890 You can specify the number of lines that the `list' command shows.
5893 * New machines supported (host and target)
5895 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5896 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5897 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5899 * New hosts supported (not targets)
5901 IBM RT/PC: romp-ibm-aix or rtpc
5903 * New targets supported (not hosts)
5905 AMD 29000 embedded with COFF a29k-none-coff
5906 AMD 29000 embedded with a.out a29k-none-aout
5907 Ultracomputer remote kernel debug a29k-nyu-kern
5909 * New remote interfaces
5915 *** Changes in GDB-4.0:
5919 Wide output is wrapped at good places to make the output more readable.
5921 Gdb now supports cross-debugging from a host machine of one type to a
5922 target machine of another type. Communication with the target system
5923 is over serial lines. The ``target'' command handles connecting to the
5924 remote system; the ``load'' command will download a program into the
5925 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5926 also supports debugging of realtime processes running under VxWorks,
5927 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5928 stub on the target system.
5930 New CPUs supported include the AMD 29000 and Intel 960.
5932 GDB now reads object files and symbol tables via a ``binary file''
5933 library, which allows a single copy of GDB to debug programs of multiple
5934 object file types such as a.out and coff.
5936 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5937 refcard.dvi and refcard.ps are available to format it).
5940 * Control-Variable user interface simplified
5942 All variables that control the operation of the debugger can be set
5943 by the ``set'' command, and displayed by the ``show'' command.
5945 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5946 ``Show prompt'' produces the response:
5947 Gdb's prompt is new-gdb=>.
5949 What follows are the NEW set commands. The command ``help set'' will
5950 print a complete list of old and new set commands. ``help set FOO''
5951 will give a longer description of the variable FOO. ``show'' will show
5952 all of the variable descriptions and their current settings.
5954 confirm on/off: Enables warning questions for operations that are
5955 hard to recover from, e.g. rerunning the program while
5956 it is already running. Default is ON.
5958 editing on/off: Enables EMACS style command line editing
5959 of input. Previous lines can be recalled with
5960 control-P, the current line can be edited with control-B,
5961 you can search for commands with control-R, etc.
5964 history filename NAME: NAME is where the gdb command history
5965 will be stored. The default is .gdb_history,
5966 or the value of the environment variable
5969 history size N: The size, in commands, of the command history. The
5970 default is 256, or the value of the environment variable
5973 history save on/off: If this value is set to ON, the history file will
5974 be saved after exiting gdb. If set to OFF, the
5975 file will not be saved. The default is OFF.
5977 history expansion on/off: If this value is set to ON, then csh-like
5978 history expansion will be performed on
5979 command line input. The default is OFF.
5981 radix N: Sets the default radix for input and output. It can be set
5982 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5983 in the current radix, so "set radix 10" is always a no-op.
5985 height N: This integer value is the number of lines on a page. Default
5986 is 24, the current `stty rows'' setting, or the ``li#''
5987 setting from the termcap entry matching the environment
5990 width N: This integer value is the number of characters on a line.
5991 Default is 80, the current `stty cols'' setting, or the ``co#''
5992 setting from the termcap entry matching the environment
5995 Note: ``set screensize'' is obsolete. Use ``set height'' and
5996 ``set width'' instead.
5998 print address on/off: Print memory addresses in various command displays,
5999 such as stack traces and structure values. Gdb looks
6000 more ``symbolic'' if you turn this off; it looks more
6001 ``machine level'' with it on. Default is ON.
6003 print array on/off: Prettyprint arrays. New convenient format! Default
6006 print demangle on/off: Print C++ symbols in "source" form if on,
6009 print asm-demangle on/off: Same, for assembler level printouts
6012 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6015 * Support for Epoch Environment.
6017 The epoch environment is a version of Emacs v18 with windowing. One
6018 new command, ``inspect'', is identical to ``print'', except that if you
6019 are running in the epoch environment, the value is printed in its own
6023 * Support for Shared Libraries
6025 GDB can now debug programs and core files that use SunOS shared libraries.
6026 Symbols from a shared library cannot be referenced
6027 before the shared library has been linked with the program (this
6028 happens after you type ``run'' and before the function main() is entered).
6029 At any time after this linking (including when examining core files
6030 from dynamically linked programs), gdb reads the symbols from each
6031 shared library when you type the ``sharedlibrary'' command.
6032 It can be abbreviated ``share''.
6034 sharedlibrary REGEXP: Load shared object library symbols for files
6035 matching a unix regular expression. No argument
6036 indicates to load symbols for all shared libraries.
6038 info sharedlibrary: Status of loaded shared libraries.
6043 A watchpoint stops execution of a program whenever the value of an
6044 expression changes. Checking for this slows down execution
6045 tremendously whenever you are in the scope of the expression, but is
6046 quite useful for catching tough ``bit-spreader'' or pointer misuse
6047 problems. Some machines such as the 386 have hardware for doing this
6048 more quickly, and future versions of gdb will use this hardware.
6050 watch EXP: Set a watchpoint (breakpoint) for an expression.
6052 info watchpoints: Information about your watchpoints.
6054 delete N: Deletes watchpoint number N (same as breakpoints).
6055 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6056 enable N: Re-enables watchpoint number N (same as breakpoints).
6059 * C++ multiple inheritance
6061 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6064 * C++ exception handling
6066 Gdb now supports limited C++ exception handling. Besides the existing
6067 ability to breakpoint on an exception handler, gdb can breakpoint on
6068 the raising of an exception (before the stack is peeled back to the
6071 catch FOO: If there is a FOO exception handler in the dynamic scope,
6072 set a breakpoint to catch exceptions which may be raised there.
6073 Multiple exceptions (``catch foo bar baz'') may be caught.
6075 info catch: Lists all exceptions which may be caught in the
6076 current stack frame.
6079 * Minor command changes
6081 The command ``call func (arg, arg, ...)'' now acts like the print
6082 command, except it does not print or save a value if the function's result
6083 is void. This is similar to dbx usage.
6085 The ``up'' and ``down'' commands now always print the frame they end up
6086 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6087 frames without printing.
6089 * New directory command
6091 'dir' now adds directories to the FRONT of the source search path.
6092 The path starts off empty. Source files that contain debug information
6093 about the directory in which they were compiled can be found even
6094 with an empty path; Sun CC and GCC include this information. If GDB can't
6095 find your source file in the current directory, type "dir .".
6097 * Configuring GDB for compilation
6099 For normal use, type ``./configure host''. See README or gdb.texinfo
6102 GDB now handles cross debugging. If you are remotely debugging between
6103 two different machines, type ``./configure host -target=targ''.
6104 Host is the machine where GDB will run; targ is the machine
6105 where the program that you are debugging will run.