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".
116 show debug dwarf-line
117 Control display of debugging info regarding DWARF line processing.
121 Set the maximum number of candidates to be considered during
122 completion. The default value is 200. This limit allows GDB
123 to avoid generating large completion lists, the computation of
124 which can cause the debugger to become temporarily unresponsive.
126 maint set symbol-cache-size
127 maint show symbol-cache-size
128 Control the size of the symbol cache.
130 set|show record btrace bts buffer-size
131 Set and show the size of the ring buffer used for branch tracing in
133 The obtained size may differ from the requested size. Use "info
134 record" to see the obtained buffer size.
136 * The command 'thread apply all' can now support new option '-ascending'
137 to call its specified command for all threads in ascending order.
139 * Python/Guile scripting
141 ** GDB now supports auto-loading of Python/Guile scripts contained in the
142 special section named `.debug_gdb_scripts'.
146 qXfer:btrace-conf:read
147 Return the branch trace configuration for the current thread.
149 Qbtrace-conf:bts:size
150 Set the requested ring buffer size for branch tracing in BTS format.
153 Indicates a memory breakpoint instruction was executed, irrespective
154 of whether it was GDB that planted the breakpoint or the breakpoint
155 is hardcoded in the program. This is required for correct non-stop
159 Indicates the target stopped for a hardware breakpoint. This is
160 required for correct non-stop mode operation.
163 Return information about files on the remote system.
166 Return the full absolute name of the file that was executed to
167 create a process running on the remote system.
170 Indicates that a fork system call was executed.
173 Indicates that a vfork system call was executed.
175 vforkdone stop reason
176 Indicates that a vfork child of the specified process has executed
177 an exec or exit, allowing the vfork parent to resume execution.
179 fork-events and vfork-events features in qSupported
180 The qSupported packet allows GDB to request support for fork and
181 vfork events using new 'gdbfeatures' fork-events and vfork-events,
182 and the qSupported response can contain the corresponding
183 'stubfeatures'. Set and show commands can be used to display
184 whether these features are enabled.
186 * Extended-remote fork events
188 ** GDB now has support for fork events on extended-remote Linux
189 targets. For targets with Linux kernels 2.5.60 and later, this
190 enables follow-fork-mode and detach-on-fork for both fork and
191 vfork, as well as fork and vfork catchpoints.
193 * The info record command now shows the recording format and the
194 branch tracing configuration for the current thread when using
195 the btrace record target.
196 For the BTS format, it shows the ring buffer size.
198 * GDB now has support for DTrace USDT (Userland Static Defined
199 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
201 * GDB now supports access to vector registers on S/390 GNU/Linux
204 * Removed command line options
206 -xdb HP-UX XDB compatibility mode.
208 * Removed targets and native configurations
210 HP/PA running HP-UX hppa*-*-hpux*
211 Itanium running HP-UX ia64-*-hpux*
213 *** Changes in GDB 7.9.1
217 ** Xmethods can now specify a result type.
219 *** Changes in GDB 7.9
221 * GDB now supports hardware watchpoints on x86 GNU Hurd.
225 ** You can now access frame registers from Python scripts.
226 ** New attribute 'producer' for gdb.Symtab objects.
227 ** gdb.Objfile objects have a new attribute "progspace",
228 which is the gdb.Progspace object of the containing program space.
229 ** gdb.Objfile objects have a new attribute "owner".
230 ** gdb.Objfile objects have a new attribute "build_id",
231 which is the build ID generated when the file was built.
232 ** gdb.Objfile objects have a new method "add_separate_debug_file".
233 ** A new event "gdb.clear_objfiles" has been added, triggered when
234 selecting a new file to debug.
235 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
236 ** New function gdb.lookup_objfile.
238 New events which are triggered when GDB modifies the state of the
241 ** gdb.events.inferior_call_pre: Function call is about to be made.
242 ** gdb.events.inferior_call_post: Function call has just been made.
243 ** gdb.events.memory_changed: A memory location has been altered.
244 ** gdb.events.register_changed: A register has been altered.
246 * New Python-based convenience functions:
248 ** $_caller_is(name [, number_of_frames])
249 ** $_caller_matches(regexp [, number_of_frames])
250 ** $_any_caller_is(name [, number_of_frames])
251 ** $_any_caller_matches(regexp [, number_of_frames])
253 * GDB now supports the compilation and injection of source code into
254 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
255 to compile the source code to object code, and if successful, inject
256 and execute that code within the current context of the inferior.
257 Currently the C language is supported. The commands used to
258 interface with this new feature are:
260 compile code [-raw|-r] [--] [source code]
261 compile file [-raw|-r] filename
265 demangle [-l language] [--] name
266 Demangle "name" in the specified language, or the current language
267 if elided. This command is renamed from the "maint demangle" command.
268 The latter is kept as a no-op to avoid "maint demangle" being interpreted
269 as "maint demangler-warning".
271 queue-signal signal-name-or-number
272 Queue a signal to be delivered to the thread when it is resumed.
274 add-auto-load-scripts-directory directory
275 Add entries to the list of directories from which to load auto-loaded
278 maint print user-registers
279 List all currently available "user" registers.
281 compile code [-r|-raw] [--] [source code]
282 Compile, inject, and execute in the inferior the executable object
283 code produced by compiling the provided source code.
285 compile file [-r|-raw] filename
286 Compile and inject into the inferior the executable object code
287 produced by compiling the source code stored in the filename
290 * On resume, GDB now always passes the signal the program had stopped
291 for to the thread the signal was sent to, even if the user changed
292 threads before resuming. Previously GDB would often (but not
293 always) deliver the signal to the thread that happens to be current
296 * Conversely, the "signal" command now consistently delivers the
297 requested signal to the current thread. GDB now asks for
298 confirmation if the program had stopped for a signal and the user
299 switched threads meanwhile.
301 * "breakpoint always-inserted" modes "off" and "auto" merged.
303 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
304 won't remove breakpoints from the target until all threads stop,
305 even in non-stop mode. The "auto" mode has been removed, and "off"
306 is now the default mode.
310 set debug symbol-lookup
311 show debug symbol-lookup
312 Control display of debugging info regarding symbol lookup.
316 ** The -list-thread-groups command outputs an exit-code field for
317 inferiors that have exited.
321 MIPS SDE mips*-sde*-elf*
325 Support for these obsolete configurations has been removed.
327 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
328 SGI Irix-5.x mips-*-irix5*
329 SGI Irix-6.x mips-*-irix6*
330 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
331 VAX running Ultrix vax-*-ultrix*
333 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
334 and "assf"), have been removed. Use the "sharedlibrary" command, or
335 its alias "share", instead.
337 *** Changes in GDB 7.8
339 * New command line options
342 This is an alias for the --data-directory option.
344 * GDB supports printing and modifying of variable length automatic arrays
345 as specified in ISO C99.
347 * The ARM simulator now supports instruction level tracing
348 with or without disassembly.
352 GDB now has support for scripting using Guile. Whether this is
353 available is determined at configure time.
354 Guile version 2.0 or greater is required.
355 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
357 * New commands (for set/show, see "New options" below)
361 Invoke CODE by passing it to the Guile interpreter.
365 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
367 info auto-load guile-scripts [regexp]
368 Print the list of automatically loaded Guile scripts.
370 * The source command is now capable of sourcing Guile scripts.
371 This feature is dependent on the debugger being built with Guile support.
375 set print symbol-loading (off|brief|full)
376 show print symbol-loading
377 Control whether to print informational messages when loading symbol
378 information for a file. The default is "full", but when debugging
379 programs with large numbers of shared libraries the amount of output
382 set guile print-stack (none|message|full)
383 show guile print-stack
384 Show a stack trace when an error is encountered in a Guile script.
386 set auto-load guile-scripts (on|off)
387 show auto-load guile-scripts
388 Control auto-loading of Guile script files.
390 maint ada set ignore-descriptive-types (on|off)
391 maint ada show ignore-descriptive-types
392 Control whether the debugger should ignore descriptive types in Ada
393 programs. The default is not to ignore the descriptive types. See
394 the user manual for more details on descriptive types and the intended
395 usage of this option.
397 set auto-connect-native-target
399 Control whether GDB is allowed to automatically connect to the
400 native target for the run, attach, etc. commands when not connected
401 to any target yet. See also "target native" below.
403 set record btrace replay-memory-access (read-only|read-write)
404 show record btrace replay-memory-access
405 Control what memory accesses are allowed during replay.
407 maint set target-async (on|off)
408 maint show target-async
409 This controls whether GDB targets operate in synchronous or
410 asynchronous mode. Normally the default is asynchronous, if it is
411 available; but this can be changed to more easily debug problems
412 occurring only in synchronous mode.
414 set mi-async (on|off)
416 Control whether MI asynchronous mode is preferred. This supersedes
417 "set target-async" of previous GDB versions.
419 * "set target-async" is deprecated as a CLI option and is now an alias
420 for "set mi-async" (only puts MI into async mode).
422 * Background execution commands (e.g., "c&", "s&", etc.) are now
423 possible ``out of the box'' if the target supports them. Previously
424 the user would need to explicitly enable the possibility with the
425 "set target-async on" command.
427 * New features in the GDB remote stub, GDBserver
429 ** New option --debug-format=option1[,option2,...] allows one to add
430 additional text to each output. At present only timestamps
431 are supported: --debug-format=timestamps.
432 Timestamps can also be turned on with the
433 "monitor set debug-format timestamps" command from GDB.
435 * The 'record instruction-history' command now starts counting instructions
436 at one. This also affects the instruction ranges reported by the
437 'record function-call-history' command when given the /i modifier.
439 * The command 'record function-call-history' supports a new modifier '/c' to
440 indent the function names based on their call stack depth.
441 The fields for the '/i' and '/l' modifier have been reordered.
442 The source line range is now prefixed with 'at'.
443 The instruction range is now prefixed with 'inst'.
444 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
445 "record instruction-history" and "list" commands.
447 * The ranges given as arguments to the 'record function-call-history' and
448 'record instruction-history' commands are now inclusive.
450 * The btrace record target now supports the 'record goto' command.
451 For locations inside the execution trace, the back trace is computed
452 based on the information stored in the execution trace.
454 * The btrace record target supports limited reverse execution and replay.
455 The target does not record data and therefore does not allow reading
458 * The "catch syscall" command now works on s390*-linux* targets.
460 * The "compare-sections" command is no longer specific to target
461 remote. It now works with all targets.
463 * All native targets are now consistently called "native".
464 Consequently, the "target child", "target GNU", "target djgpp",
465 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
466 commands have been replaced with "target native". The QNX/NTO port
467 leaves the "procfs" target in place and adds a "native" target for
468 consistency with other ports. The impact on users should be minimal
469 as these commands previously either throwed an error, or were
470 no-ops. The target's name is visible in the output of the following
471 commands: "help target", "info target", "info files", "maint print
474 * The "target native" command now connects to the native target. This
475 can be used to launch native programs even when "set
476 auto-connect-native-target" is set to off.
478 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.
480 * Support for Intel(R) AVX-512 registers on GNU/Linux.
481 Support displaying and modifying Intel(R) AVX-512 registers
482 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
486 qXfer:btrace:read's annex
487 The qXfer:btrace:read packet supports a new annex 'delta' to read
488 branch trace incrementally.
492 ** Valid Python operations on gdb.Value objects representing
493 structs/classes invoke the corresponding overloaded operators if
495 ** New `Xmethods' feature in the Python API. Xmethods are
496 additional methods or replacements for existing methods of a C++
497 class. This feature is useful for those cases where a method
498 defined in C++ source code could be inlined or optimized out by
499 the compiler, making it unavailable to GDB.
502 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
504 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
505 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
506 its alias "share", instead.
508 * The commands "set remotebaud" and "show remotebaud" are no longer
509 supported. Use "set serial baud" and "show serial baud" (respectively)
514 ** A new option "-gdb-set mi-async" replaces "-gdb-set
515 target-async". The latter is left as a deprecated alias of the
516 former for backward compatibility. If the target supports it,
517 CLI background execution commands are now always possible by
518 default, independently of whether the frontend stated a
519 preference for asynchronous execution with "-gdb-set mi-async".
520 Previously "-gdb-set target-async off" affected both MI execution
521 commands and CLI execution commands.
523 *** Changes in GDB 7.7
525 * Improved support for process record-replay and reverse debugging on
526 arm*-linux* targets. Support for thumb32 and syscall instruction
527 recording has been added.
529 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
531 * GDB now supports Fission DWP file format version 2.
532 http://gcc.gnu.org/wiki/DebugFission
534 * New convenience function "$_isvoid", to check whether an expression
535 is void. A void expression is an expression where the type of the
536 result is "void". For example, some convenience variables may be
537 "void" when evaluated (e.g., "$_exitcode" before the execution of
538 the program being debugged; or an undefined convenience variable).
539 Another example, when calling a function whose return type is
542 * The "maintenance print objfiles" command now takes an optional regexp.
544 * The "catch syscall" command now works on arm*-linux* targets.
546 * GDB now consistently shows "<not saved>" when printing values of
547 registers the debug info indicates have not been saved in the frame
548 and there's nowhere to retrieve them from
549 (callee-saved/call-clobbered registers):
554 (gdb) info registers rax
557 Before, the former would print "<optimized out>", and the latter
558 "*value not available*".
560 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
565 ** Frame filters and frame decorators have been added.
566 ** Temporary breakpoints are now supported.
567 ** Line tables representation has been added.
568 ** New attribute 'parent_type' for gdb.Field objects.
569 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
570 ** New attribute 'name' for gdb.Type objects.
574 Nios II ELF nios2*-*-elf
575 Nios II GNU/Linux nios2*-*-linux
576 Texas Instruments MSP430 msp430*-*-elf
578 * Removed native configurations
580 Support for these a.out NetBSD and OpenBSD obsolete configurations has
581 been removed. ELF variants of these configurations are kept supported.
583 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
584 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
585 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
586 i[34567]86-*-openbsd3.[0-3]
587 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
588 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
589 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
593 Like "catch throw", but catches a re-thrown exception.
595 Renamed from old "maint check-symtabs".
597 Perform consistency checks on symtabs.
599 Expand symtabs matching an optional regexp.
602 Display the details of GDB configure-time options.
604 maint set|show per-command
605 maint set|show per-command space
606 maint set|show per-command time
607 maint set|show per-command symtab
608 Enable display of per-command gdb resource usage.
610 remove-symbol-file FILENAME
611 remove-symbol-file -a ADDRESS
612 Remove a symbol file added via add-symbol-file. The file to remove
613 can be identified by its filename or by an address that lies within
614 the boundaries of this symbol file in memory.
617 info exceptions REGEXP
618 Display the list of Ada exceptions defined in the program being
619 debugged. If provided, only the exceptions whose names match REGEXP
624 set debug symfile off|on
626 Control display of debugging info regarding reading symbol files and
627 symbol tables within those files
629 set print raw frame-arguments
630 show print raw frame-arguments
631 Set/show whether to print frame arguments in raw mode,
632 disregarding any defined pretty-printers.
634 set remote trace-status-packet
635 show remote trace-status-packet
636 Set/show the use of remote protocol qTStatus packet.
640 Control display of debugging messages related to Nios II targets.
644 Control whether target-assisted range stepping is enabled.
646 set startup-with-shell
647 show startup-with-shell
648 Specifies whether Unix child processes are started via a shell or
653 Use the target memory cache for accesses to the code segment. This
654 improves performance of remote debugging (particularly disassembly).
656 * You can now use a literal value 'unlimited' for options that
657 interpret 0 or -1 as meaning "unlimited". E.g., "set
658 trace-buffer-size unlimited" is now an alias for "set
659 trace-buffer-size -1" and "set height unlimited" is now an alias for
662 * The "set debug symtab-create" debugging option of GDB has been changed to
663 accept a verbosity level. 0 means "off", 1 provides basic debugging
664 output, and values of 2 or greater provides more verbose output.
666 * New command-line options
668 Display the details of GDB configure-time options.
670 * The command 'tsave' can now support new option '-ctf' to save trace
671 buffer in Common Trace Format.
673 * Newly installed $prefix/bin/gcore acts as a shell interface for the
676 * GDB now implements the the C++ 'typeid' operator.
678 * The new convenience variable $_exception holds the exception being
679 thrown or caught at an exception-related catchpoint.
681 * The exception-related catchpoints, like "catch throw", now accept a
682 regular expression which can be used to filter exceptions by type.
684 * The new convenience variable $_exitsignal is automatically set to
685 the terminating signal number when the program being debugged dies
686 due to an uncaught signal.
690 ** All MI commands now accept an optional "--language" option.
691 Support for this feature can be verified by using the "-list-features"
692 command, which should contain "language-option".
694 ** The new command -info-gdb-mi-command allows the user to determine
695 whether a GDB/MI command is supported or not.
697 ** The "^error" result record returned when trying to execute an undefined
698 GDB/MI command now provides a variable named "code" whose content is the
699 "undefined-command" error code. Support for this feature can be verified
700 by using the "-list-features" command, which should contain
701 "undefined-command-error-code".
703 ** The -trace-save MI command can optionally save trace buffer in Common
706 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
708 ** The command -data-list-register-values now accepts an optional
709 "--skip-unavailable" option. When used, only the available registers
712 ** The new command -trace-frame-collected dumps collected variables,
713 computed expressions, tvars, memory and registers in a traceframe.
715 ** The commands -stack-list-locals, -stack-list-arguments and
716 -stack-list-variables now accept an option "--skip-unavailable".
717 When used, only the available locals or arguments are displayed.
719 ** The -exec-run command now accepts an optional "--start" option.
720 When used, the command follows the same semantics as the "start"
721 command, stopping the program's execution at the start of its
722 main subprogram. Support for this feature can be verified using
723 the "-list-features" command, which should contain
724 "exec-run-start-option".
726 ** The new commands -catch-assert and -catch-exceptions insert
727 catchpoints stopping the program when Ada exceptions are raised.
729 ** The new command -info-ada-exceptions provides the equivalent of
730 the new "info exceptions" command.
732 * New system-wide configuration scripts
733 A GDB installation now provides scripts suitable for use as system-wide
734 configuration scripts for the following systems:
738 * GDB now supports target-assigned range stepping with remote targets.
739 This improves the performance of stepping source lines by reducing
740 the number of control packets from/to GDB. See "New remote packets"
743 * GDB now understands the element 'tvar' in the XML traceframe info.
744 It has the id of the collected trace state variables.
746 * On S/390 targets that provide the transactional-execution feature,
747 the program interruption transaction diagnostic block (TDB) is now
748 represented as a number of additional "registers" in GDB.
754 The vCont packet supports a new 'r' action, that tells the remote
755 stub to step through an address range itself, without GDB
756 involvemement at each single-step.
758 qXfer:libraries-svr4:read's annex
759 The previously unused annex of the qXfer:libraries-svr4:read packet
760 is now used to support passing an argument list. The remote stub
761 reports support for this argument list to GDB's qSupported query.
762 The defined arguments are "start" and "prev", used to reduce work
763 necessary for library list updating, resulting in significant
766 * New features in the GDB remote stub, GDBserver
768 ** GDBserver now supports target-assisted range stepping. Currently
769 enabled on x86/x86_64 GNU/Linux targets.
771 ** GDBserver now adds element 'tvar' in the XML in the reply to
772 'qXfer:traceframe-info:read'. It has the id of the collected
773 trace state variables.
775 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
778 * New 'z' formatter for printing and examining memory, this displays the
779 value as hexadecimal zero padded on the left to the size of the type.
781 * GDB can now use Windows x64 unwinding data.
783 * The "set remotebaud" command has been replaced by "set serial baud".
784 Similarly, "show remotebaud" has been replaced by "show serial baud".
785 The "set remotebaud" and "show remotebaud" commands are still available
786 to provide backward compatibility with older versions of GDB.
788 *** Changes in GDB 7.6
790 * Target record has been renamed to record-full.
791 Record/replay is now enabled with the "record full" command.
792 This also affects settings that are associated with full record/replay
793 that have been moved from "set/show record" to "set/show record full":
795 set|show record full insn-number-max
796 set|show record full stop-at-limit
797 set|show record full memory-query
799 * A new record target "record-btrace" has been added. The new target
800 uses hardware support to record the control-flow of a process. It
801 does not support replaying the execution, but it implements the
802 below new commands for investigating the recorded execution log.
803 This new recording method can be enabled using:
807 The "record-btrace" target is only available on Intel Atom processors
808 and requires a Linux kernel 2.6.32 or later.
810 * Two new commands have been added for record/replay to give information
811 about the recorded execution without having to replay the execution.
812 The commands are only supported by "record btrace".
814 record instruction-history prints the execution history at
815 instruction granularity
817 record function-call-history prints the execution history at
820 * New native configurations
822 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
823 FreeBSD/powerpc powerpc*-*-freebsd
824 x86_64/Cygwin x86_64-*-cygwin*
825 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
829 ARM AArch64 aarch64*-*-elf
830 ARM AArch64 GNU/Linux aarch64*-*-linux
831 Lynx 178 PowerPC powerpc-*-lynx*178
832 x86_64/Cygwin x86_64-*-cygwin*
833 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
835 * If the configured location of system.gdbinit file (as given by the
836 --with-system-gdbinit option at configure time) is in the
837 data-directory (as specified by --with-gdb-datadir at configure
838 time) or in one of its subdirectories, then GDB will look for the
839 system-wide init file in the directory specified by the
840 --data-directory command-line option.
842 * New command line options:
844 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
845 other initialization files, unlike -nx which disables all of them.
847 * Removed command line options
849 -epoch This was used by the gdb mode in Epoch, an ancient fork of
852 * The 'ptype' and 'whatis' commands now accept an argument to control
855 * 'info proc' now works on some core files.
859 ** Vectors can be created with gdb.Type.vector.
861 ** Python's atexit.register now works in GDB.
863 ** Types can be pretty-printed via a Python API.
865 ** Python 3 is now supported (in addition to Python 2.4 or later)
867 ** New class gdb.Architecture exposes GDB's internal representation
868 of architecture in the Python API.
870 ** New method Frame.architecture returns the gdb.Architecture object
871 corresponding to the frame's architecture.
873 * New Python-based convenience functions:
875 ** $_memeq(buf1, buf2, length)
876 ** $_streq(str1, str2)
878 ** $_regex(str, regex)
880 * The 'cd' command now defaults to using '~' (the home directory) if not
883 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
884 default for GCC since November 2000.
886 * The command 'forward-search' can now be abbreviated as 'fo'.
888 * The command 'info tracepoints' can now display 'installed on target'
889 or 'not installed on target' for each non-pending location of tracepoint.
891 * New configure options
893 --enable-libmcheck/--disable-libmcheck
894 By default, development versions are built with -lmcheck on hosts
895 that support it, in order to help track memory corruption issues.
896 Release versions, on the other hand, are built without -lmcheck
897 by default. The --enable-libmcheck/--disable-libmcheck configure
898 options allow the user to override that default.
899 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
900 This configure option allows the user to build GDB with
901 libbabeltrace using which GDB can read Common Trace Format data.
903 * New commands (for set/show, see "New options" below)
906 Catch signals. This is similar to "handle", but allows commands and
907 conditions to be attached.
910 List the BFDs known to GDB.
912 python-interactive [command]
914 Start a Python interactive prompt, or evaluate the optional command
915 and print the result of expressions.
918 "py" is a new alias for "python".
920 enable type-printer [name]...
921 disable type-printer [name]...
922 Enable or disable type printers.
926 ** For the Renesas Super-H architecture, the "regs" command has been removed
927 (has been deprecated in GDB 7.5), and "info all-registers" should be used
932 set print type methods (on|off)
933 show print type methods
934 Control whether method declarations are displayed by "ptype".
935 The default is to show them.
937 set print type typedefs (on|off)
938 show print type typedefs
939 Control whether typedef definitions are displayed by "ptype".
940 The default is to show them.
942 set filename-display basename|relative|absolute
943 show filename-display
944 Control the way in which filenames is displayed.
945 The default is "relative", which preserves previous behavior.
947 set trace-buffer-size
948 show trace-buffer-size
949 Request target to change the size of trace buffer.
951 set remote trace-buffer-size-packet auto|on|off
952 show remote trace-buffer-size-packet
953 Control the use of the remote protocol `QTBuffer:size' packet.
957 Control display of debugging messages related to ARM AArch64.
960 set debug coff-pe-read
961 show debug coff-pe-read
962 Control display of debugging messages related to reading of COFF/PE
967 Control display of debugging messages related to Mach-O symbols
970 set debug notification
971 show debug notification
972 Control display of debugging info for async remote notification.
976 ** Command parameter changes are now notified using new async record
977 "=cmd-param-changed".
978 ** Trace frame changes caused by command "tfind" are now notified using
979 new async record "=traceframe-changed".
980 ** The creation, deletion and modification of trace state variables
981 are now notified using new async records "=tsv-created",
982 "=tsv-deleted" and "=tsv-modified".
983 ** The start and stop of process record are now notified using new
984 async record "=record-started" and "=record-stopped".
985 ** Memory changes are now notified using new async record
987 ** The data-disassemble command response will include a "fullname" field
988 containing the absolute file name when source has been requested.
989 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
990 command, to allow pattern filling of memory areas.
991 ** New commands "-catch-load"/"-catch-unload" added for intercepting
992 library load/unload events.
993 ** The response to breakpoint commands and breakpoint async records
994 includes an "installed" field containing a boolean state about each
995 non-pending tracepoint location is whether installed on target or not.
996 ** Output of the "-trace-status" command includes a "trace-file" field
997 containing the name of the trace file being examined. This field is
998 optional, and only present when examining a trace file.
999 ** The "fullname" field is now always present along with the "file" field,
1000 even if the file cannot be found by GDB.
1002 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1003 You must have the LZMA library available when configuring GDB for this
1004 feature to be enabled. For more information, see:
1005 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1007 * New remote packets
1010 Set the size of trace buffer. The remote stub reports support for this
1011 packet to gdb's qSupported query.
1014 Enable Branch Trace Store (BTS)-based branch tracing for the current
1015 thread. The remote stub reports support for this packet to gdb's
1019 Disable branch tracing for the current thread. The remote stub reports
1020 support for this packet to gdb's qSupported query.
1023 Read the traced branches for the current thread. The remote stub
1024 reports support for this packet to gdb's qSupported query.
1026 *** Changes in GDB 7.5
1028 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1029 for more x32 ABI info.
1031 * GDB now supports access to MIPS DSP registers on Linux targets.
1033 * GDB now supports debugging microMIPS binaries.
1035 * The "info os" command on GNU/Linux can now display information on
1036 several new classes of objects managed by the operating system:
1037 "info os procgroups" lists process groups
1038 "info os files" lists file descriptors
1039 "info os sockets" lists internet-domain sockets
1040 "info os shm" lists shared-memory regions
1041 "info os semaphores" lists semaphores
1042 "info os msg" lists message queues
1043 "info os modules" lists loaded kernel modules
1045 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1046 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1047 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1048 options and inspect the probe arguments using the new $_probe_arg family
1049 of convenience variables. You can obtain more information about SystemTap
1050 in <http://sourceware.org/systemtap/>.
1052 * GDB now supports reversible debugging on ARM, it allows you to
1053 debug basic ARM and THUMB instructions, and provides
1054 record/replay support.
1056 * The option "symbol-reloading" has been deleted as it is no longer used.
1060 ** GDB commands implemented in Python can now be put in command class
1063 ** The "maint set python print-stack on|off" is now deleted.
1065 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1066 apply "flag enum"-style pretty-printing to any enum.
1068 ** gdb.lookup_symbol can now work when there is no current frame.
1070 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1071 the source at which the symbol was defined.
1073 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1074 method 'value'. The former indicates whether the symbol needs a
1075 frame in order to compute its value, and the latter computes the
1078 ** A new method 'referenced_value' on gdb.Value objects which can
1079 dereference pointer as well as C++ reference values.
1081 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1082 which return the global and static blocks (as gdb.Block objects),
1083 of the underlying symbol table, respectively.
1085 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1086 object associated with a PC value.
1088 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1089 of the address range occupied by code for the current source line.
1091 * Go language support.
1092 GDB now supports debugging programs written in the Go programming
1095 * GDBserver now supports stdio connections.
1096 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1098 * The binary "gdbtui" can no longer be built or installed.
1099 Use "gdb -tui" instead.
1101 * GDB will now print "flag" enums specially. A flag enum is one where
1102 all the enumerator values have no bits in common when pairwise
1103 "and"ed. When printing a value whose type is a flag enum, GDB will
1104 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1105 (gdb) print (enum E) 3
1108 * The filename part of a linespec will now match trailing components
1109 of a source file name. For example, "break gcc/expr.c:1000" will
1110 now set a breakpoint in build/gcc/expr.c, but not
1111 build/libcpp/expr.c.
1113 * The "info proc" and "generate-core-file" commands will now also
1114 work on remote targets connected to GDBserver on Linux.
1116 * The command "info catch" has been removed. It has been disabled
1117 since December 2007.
1119 * The "catch exception" and "catch assert" commands now accept
1120 a condition at the end of the command, much like the "break"
1121 command does. For instance:
1123 (gdb) catch exception Constraint_Error if Barrier = True
1125 Previously, it was possible to add a condition to such catchpoints,
1126 but it had to be done as a second step, after the catchpoint had been
1127 created, using the "condition" command.
1129 * The "info static-tracepoint-marker" command will now also work on
1130 native Linux targets with in-process agent.
1132 * GDB can now set breakpoints on inlined functions.
1134 * The .gdb_index section has been updated to include symbols for
1135 inlined functions. GDB will ignore older .gdb_index sections by
1136 default, which could cause symbol files to be loaded more slowly
1137 until their .gdb_index sections can be recreated. The new command
1138 "set use-deprecated-index-sections on" will cause GDB to use any older
1139 .gdb_index sections it finds. This will restore performance, but the
1140 ability to set breakpoints on inlined functions will be lost in symbol
1141 files with older .gdb_index sections.
1143 The .gdb_index section has also been updated to record more information
1144 about each symbol. This speeds up the "info variables", "info functions"
1145 and "info types" commands when used with programs having the .gdb_index
1146 section, as well as speeding up debugging with shared libraries using
1147 the .gdb_index section.
1149 * Ada support for GDB/MI Variable Objects has been added.
1151 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1156 ** New command -info-os is the MI equivalent of "info os".
1158 ** Output logs ("set logging" and related) now include MI output.
1162 ** "set use-deprecated-index-sections on|off"
1163 "show use-deprecated-index-sections on|off"
1164 Controls the use of deprecated .gdb_index sections.
1166 ** "catch load" and "catch unload" can be used to stop when a shared
1167 library is loaded or unloaded, respectively.
1169 ** "enable count" can be used to auto-disable a breakpoint after
1172 ** "info vtbl" can be used to show the virtual method tables for
1173 C++ and Java objects.
1175 ** "explore" and its sub commands "explore value" and "explore type"
1176 can be used to recursively explore values and types of
1177 expressions. These commands are available only if GDB is
1178 configured with '--with-python'.
1180 ** "info auto-load" shows status of all kinds of auto-loaded files,
1181 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1182 sequences of commands files, "info auto-load python-scripts"
1183 shows status of auto-loading Python script files,
1184 "info auto-load local-gdbinit" shows status of loading init file
1185 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1186 status of inferior specific thread debugging shared library loading.
1188 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1189 and "show auto-load-scripts" commands have been deprecated, use their
1190 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1191 and "show auto-load python-scripts" counterparts instead.
1193 ** "dprintf location,format,args..." creates a dynamic printf, which
1194 is basically a breakpoint that does a printf and immediately
1195 resumes your program's execution, so it is like a printf that you
1196 can insert dynamically at runtime instead of at compiletime.
1198 ** "set print symbol"
1200 Controls whether GDB attempts to display the symbol, if any,
1201 corresponding to addresses it prints. This defaults to "on", but
1202 you can set it to "off" to restore GDB's previous behavior.
1204 * Deprecated commands
1206 ** For the Renesas Super-H architecture, the "regs" command has been
1207 deprecated, and "info all-registers" should be used instead.
1211 Renesas RL78 rl78-*-elf
1212 HP OpenVMS ia64 ia64-hp-openvms*
1214 * GDBserver supports evaluation of breakpoint conditions. When
1215 support is advertised by GDBserver, GDB may be told to send the
1216 breakpoint conditions in bytecode form to GDBserver. GDBserver
1217 will only report the breakpoint trigger to GDB when its condition
1222 set mips compression
1223 show mips compression
1224 Select the compressed ISA encoding used in functions that have no symbol
1225 information available. The encoding can be set to either of:
1228 and is updated automatically from ELF file flags if available.
1230 set breakpoint condition-evaluation
1231 show breakpoint condition-evaluation
1232 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1233 GDBserver ("target"). Default option "auto" chooses the most efficient
1235 This option can improve debugger efficiency depending on the speed of the
1239 Disable auto-loading globally.
1242 Show auto-loading setting of all kinds of auto-loaded files.
1244 set auto-load gdb-scripts on|off
1245 show auto-load gdb-scripts
1246 Control auto-loading of GDB canned sequences of commands files.
1248 set auto-load python-scripts on|off
1249 show auto-load python-scripts
1250 Control auto-loading of Python script files.
1252 set auto-load local-gdbinit on|off
1253 show auto-load local-gdbinit
1254 Control loading of init file (.gdbinit) from current directory.
1256 set auto-load libthread-db on|off
1257 show auto-load libthread-db
1258 Control auto-loading of inferior specific thread debugging shared library.
1260 set auto-load scripts-directory <dir1>[:<dir2>...]
1261 show auto-load scripts-directory
1262 Set a list of directories from which to load auto-loaded scripts.
1263 Automatically loaded Python scripts and GDB scripts are located in one
1264 of the directories listed by this option.
1265 The delimiter (':' above) may differ according to the host platform.
1267 set auto-load safe-path <dir1>[:<dir2>...]
1268 show auto-load safe-path
1269 Set a list of directories from which it is safe to auto-load files.
1270 The delimiter (':' above) may differ according to the host platform.
1272 set debug auto-load on|off
1273 show debug auto-load
1274 Control display of debugging info for auto-loading the files above.
1276 set dprintf-style gdb|call|agent
1278 Control the way in which a dynamic printf is performed; "gdb"
1279 requests a GDB printf command, while "call" causes dprintf to call a
1280 function in the inferior. "agent" requests that the target agent
1281 (such as GDBserver) do the printing.
1283 set dprintf-function <expr>
1284 show dprintf-function
1285 set dprintf-channel <expr>
1286 show dprintf-channel
1287 Set the function and optional first argument to the call when using
1288 the "call" style of dynamic printf.
1290 set disconnected-dprintf on|off
1291 show disconnected-dprintf
1292 Control whether agent-style dynamic printfs continue to be in effect
1293 after GDB disconnects.
1295 * New configure options
1297 --with-auto-load-dir
1298 Configure default value for the 'set auto-load scripts-directory'
1299 setting above. It defaults to '$debugdir:$datadir/auto-load',
1300 $debugdir representing global debugging info directories (available
1301 via 'show debug-file-directory') and $datadir representing GDB's data
1302 directory (available via 'show data-directory').
1304 --with-auto-load-safe-path
1305 Configure default value for the 'set auto-load safe-path' setting
1306 above. It defaults to the --with-auto-load-dir setting.
1308 --without-auto-load-safe-path
1309 Set 'set auto-load safe-path' to '/', effectively disabling this
1312 * New remote packets
1314 z0/z1 conditional breakpoints extension
1316 The z0/z1 breakpoint insertion packets have been extended to carry
1317 a list of conditional expressions over to the remote stub depending on the
1318 condition evaluation mode. The use of this extension can be controlled
1319 via the "set remote conditional-breakpoints-packet" command.
1323 Specify the signals which the remote stub may pass to the debugged
1324 program without GDB involvement.
1326 * New command line options
1328 --init-command=FILE, -ix Like --command, -x but execute it
1329 before loading inferior.
1330 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1331 execute it before loading inferior.
1333 *** Changes in GDB 7.4
1335 * GDB now handles ambiguous linespecs more consistently; the existing
1336 FILE:LINE support has been expanded to other types of linespecs. A
1337 breakpoint will now be set on all matching locations in all
1338 inferiors, and locations will be added or removed according to
1341 * GDB now allows you to skip uninteresting functions and files when
1342 stepping with the "skip function" and "skip file" commands.
1344 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1345 and "show remote hardware-watchpoint-length-limit". These allows to
1346 set or show the maximum length limit (in bytes) of a remote
1347 target hardware watchpoint.
1349 This allows e.g. to use "unlimited" hardware watchpoints with the
1350 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1351 watchpoints are slower than real hardware watchpoints but are
1352 significantly faster than gdb software watchpoints.
1356 ** The register_pretty_printer function in module gdb.printing now takes
1357 an optional `replace' argument. If True, the new printer replaces any
1360 ** The "maint set python print-stack on|off" command has been
1361 deprecated and will be deleted in GDB 7.5.
1362 A new command: "set python print-stack none|full|message" has
1363 replaced it. Additionally, the default for "print-stack" is
1364 now "message", which just prints the error message without
1367 ** A prompt substitution hook (prompt_hook) is now available to the
1370 ** A new Python module, gdb.prompt has been added to the GDB Python
1371 modules library. This module provides functionality for
1372 escape sequences in prompts (used by set/show
1373 extended-prompt). These escape sequences are replaced by their
1374 corresponding value.
1376 ** Python commands and convenience-functions located in
1377 'data-directory'/python/gdb/command and
1378 'data-directory'/python/gdb/function are now automatically loaded
1381 ** Blocks now provide four new attributes. global_block and
1382 static_block will return the global and static blocks
1383 respectively. is_static and is_global are boolean attributes
1384 that indicate if the block is one of those two types.
1386 ** Symbols now provide the "type" attribute, the type of the symbol.
1388 ** The "gdb.breakpoint" function has been deprecated in favor of
1391 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1392 of a function. This class is based on the "finish" command
1393 available in the CLI.
1395 ** Type objects for struct and union types now allow access to
1396 the fields using standard Python dictionary (mapping) methods.
1397 For example, "some_type['myfield']" now works, as does
1398 "some_type.items()".
1400 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1403 ** A new function, "deep_items" has been added to the gdb.types
1404 module in the GDB Python modules library. This function returns
1405 an iterator over the fields of a struct or union type. Unlike
1406 the standard Python "iteritems" method, it will recursively traverse
1407 any anonymous fields.
1411 ** "*stopped" events can report several new "reason"s, such as
1414 ** Breakpoint changes are now notified using new async records, like
1415 "=breakpoint-modified".
1417 ** New command -ada-task-info.
1419 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1420 $sdir specifies the default system locations of shared libraries.
1421 $pdir specifies the directory where the libpthread used by the application
1424 GDB no longer looks in $sdir and $pdir after it has searched the directories
1425 mentioned in libthread-db-search-path. If you want to search those
1426 directories, they must be specified in libthread-db-search-path.
1427 The default value of libthread-db-search-path on GNU/Linux and Solaris
1428 systems is now "$sdir:$pdir".
1430 $pdir is not supported by gdbserver, it is currently ignored.
1431 $sdir is supported by gdbserver.
1433 * New configure option --with-iconv-bin.
1434 When using the internationalization support like the one in the GNU C
1435 library, GDB will invoke the "iconv" program to get a list of supported
1436 character sets. If this program lives in a non-standard location, one can
1437 use this option to specify where to find it.
1439 * When natively debugging programs on PowerPC BookE processors running
1440 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1441 watchpoints, which specify a mask in addition to an address to watch.
1442 The mask specifies that some bits of an address (the bits which are
1443 reset in the mask) should be ignored when matching the address accessed
1444 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1445 section in the user manual for more details.
1447 * The new option --once causes GDBserver to stop listening for connections once
1448 the first connection is made. The listening port used by GDBserver will
1449 become available after that.
1451 * New commands "info macros" and "alias" have been added.
1453 * New function parameters suffix @entry specifies value of function parameter
1454 at the time the function got called. Entry values are available only since
1460 "!" is now an alias of the "shell" command.
1461 Note that no space is needed between "!" and SHELL COMMAND.
1465 watch EXPRESSION mask MASK_VALUE
1466 The watch command now supports the mask argument which allows creation
1467 of masked watchpoints, if the current architecture supports this feature.
1469 info auto-load-scripts [REGEXP]
1470 This command was formerly named "maintenance print section-scripts".
1471 It is now generally useful and is no longer a maintenance-only command.
1473 info macro [-all] [--] MACRO
1474 The info macro command has new options `-all' and `--'. The first for
1475 printing all definitions of a macro. The second for explicitly specifying
1476 the end of arguments and the beginning of the macro name in case the macro
1477 name starts with a hyphen.
1479 collect[/s] EXPRESSIONS
1480 The tracepoint collect command now takes an optional modifier "/s"
1481 that directs it to dereference pointer-to-character types and
1482 collect the bytes of memory up to a zero byte. The behavior is
1483 similar to what you see when you use the regular print command on a
1484 string. An optional integer following the "/s" sets a bound on the
1485 number of bytes that will be collected.
1488 The trace start command now interprets any supplied arguments as a
1489 note to be recorded with the trace run, with an effect similar to
1490 setting the variable trace-notes.
1493 The trace stop command now interprets any arguments as a note to be
1494 mentioned along with the tstatus report that the trace was stopped
1495 with a command. The effect is similar to setting the variable
1498 * Tracepoints can now be enabled and disabled at any time after a trace
1499 experiment has been started using the standard "enable" and "disable"
1500 commands. It is now possible to start a trace experiment with no enabled
1501 tracepoints; GDB will display a warning, but will allow the experiment to
1502 begin, assuming that tracepoints will be enabled as needed while the trace
1505 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1506 locations with 4-byte instructions, when they were previously
1507 limited to locations with instructions of 5 bytes or longer.
1511 set debug dwarf2-read
1512 show debug dwarf2-read
1513 Turns on or off display of debugging messages related to reading
1514 DWARF debug info. The default is off.
1516 set debug symtab-create
1517 show debug symtab-create
1518 Turns on or off display of debugging messages related to symbol table
1519 creation. The default is off.
1522 show extended-prompt
1523 Set the GDB prompt, and allow escape sequences to be inserted to
1524 display miscellaneous information (see 'help set extended-prompt'
1525 for the list of sequences). This prompt (and any information
1526 accessed through the escape sequences) is updated every time the
1527 prompt is displayed.
1529 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1530 show print entry-values
1531 Set printing of frame argument values at function entry. In some cases
1532 GDB can determine the value of function argument which was passed by the
1533 function caller, even if the value was modified inside the called function.
1535 set debug entry-values
1536 show debug entry-values
1537 Control display of debugging info for determining frame argument values at
1538 function entry and virtual tail call frames.
1540 set basenames-may-differ
1541 show basenames-may-differ
1542 Set whether a source file may have multiple base names.
1543 (A "base name" is the name of a file with the directory part removed.
1544 Example: The base name of "/home/user/hello.c" is "hello.c".)
1545 If set, GDB will canonicalize file names (e.g., expand symlinks)
1546 before comparing them. Canonicalization is an expensive operation,
1547 but it allows the same file be known by more than one base name.
1548 If not set (the default), all source files are assumed to have just
1549 one base name, and gdb will do file name comparisons more efficiently.
1555 Set a user name and notes for the current and any future trace runs.
1556 This is useful for long-running and/or disconnected traces, to
1557 inform others (or yourself) as to who is running the trace, supply
1558 contact information, or otherwise explain what is going on.
1560 set trace-stop-notes
1561 show trace-stop-notes
1562 Set a note attached to the trace run, that is displayed when the
1563 trace has been stopped by a tstop command. This is useful for
1564 instance as an explanation, if you are stopping a trace run that was
1565 started by someone else.
1567 * New remote packets
1571 Dynamically enable a tracepoint in a started trace experiment.
1575 Dynamically disable a tracepoint in a started trace experiment.
1579 Set the user and notes of the trace run.
1583 Query the current status of a tracepoint.
1587 Query the minimum length of instruction at which a fast tracepoint may
1590 * Dcache size (number of lines) and line-size are now runtime-configurable
1591 via "set dcache line" and "set dcache line-size" commands.
1595 Texas Instruments TMS320C6x tic6x-*-*
1599 Renesas RL78 rl78-*-elf
1601 *** Changes in GDB 7.3.1
1603 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1605 *** Changes in GDB 7.3
1607 * GDB has a new command: "thread find [REGEXP]".
1608 It finds the thread id whose name, target id, or thread extra info
1609 matches the given regular expression.
1611 * The "catch syscall" command now works on mips*-linux* targets.
1613 * The -data-disassemble MI command now supports modes 2 and 3 for
1614 dumping the instruction opcodes.
1616 * New command line options
1618 -data-directory DIR Specify DIR as the "data-directory".
1619 This is mostly for testing purposes.
1621 * The "maint set python auto-load on|off" command has been renamed to
1622 "set auto-load-scripts on|off".
1624 * GDB has a new command: "set directories".
1625 It is like the "dir" command except that it replaces the
1626 source path list instead of augmenting it.
1628 * GDB now understands thread names.
1630 On GNU/Linux, "info threads" will display the thread name as set by
1631 prctl or pthread_setname_np.
1633 There is also a new command, "thread name", which can be used to
1634 assign a name internally for GDB to display.
1637 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1638 has been integrated into GDB.
1642 ** The function gdb.Write now accepts an optional keyword 'stream'.
1643 This keyword, when provided, will direct the output to either
1644 stdout, stderr, or GDB's logging output.
1646 ** Parameters can now be be sub-classed in Python, and in particular
1647 you may implement the get_set_doc and get_show_doc functions.
1648 This improves how Parameter set/show documentation is processed
1649 and allows for more dynamic content.
1651 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1652 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1653 have an is_valid method.
1655 ** Breakpoints can now be sub-classed in Python, and in particular
1656 you may implement a 'stop' function that is executed each time
1657 the inferior reaches that breakpoint.
1659 ** New function gdb.lookup_global_symbol looks up a global symbol.
1661 ** GDB values in Python are now callable if the value represents a
1662 function. For example, if 'some_value' represents a function that
1663 takes two integer parameters and returns a value, you can call
1664 that function like so:
1666 result = some_value (10,20)
1668 ** Module gdb.types has been added.
1669 It contains a collection of utilities for working with gdb.Types objects:
1670 get_basic_type, has_field, make_enum_dict.
1672 ** Module gdb.printing has been added.
1673 It contains utilities for writing and registering pretty-printers.
1674 New classes: PrettyPrinter, SubPrettyPrinter,
1675 RegexpCollectionPrettyPrinter.
1676 New function: register_pretty_printer.
1678 ** New commands "info pretty-printers", "enable pretty-printer" and
1679 "disable pretty-printer" have been added.
1681 ** gdb.parameter("directories") is now available.
1683 ** New function gdb.newest_frame returns the newest frame in the
1686 ** The gdb.InferiorThread class has a new "name" attribute. This
1687 holds the thread's name.
1689 ** Python Support for Inferior events.
1690 Python scripts can add observers to be notified of events
1691 occurring in the process being debugged.
1692 The following events are currently supported:
1693 - gdb.events.cont Continue event.
1694 - gdb.events.exited Inferior exited event.
1695 - gdb.events.stop Signal received, and Breakpoint hit events.
1699 ** GDB now puts template parameters in scope when debugging in an
1700 instantiation. For example, if you have:
1702 template<int X> int func (void) { return X; }
1704 then if you step into func<5>, "print X" will show "5". This
1705 feature requires proper debuginfo support from the compiler; it
1706 was added to GCC 4.5.
1708 ** The motion commands "next", "finish", "until", and "advance" now
1709 work better when exceptions are thrown. In particular, GDB will
1710 no longer lose control of the inferior; instead, the GDB will
1711 stop the inferior at the point at which the exception is caught.
1712 This functionality requires a change in the exception handling
1713 code that was introduced in GCC 4.5.
1715 * GDB now follows GCC's rules on accessing volatile objects when
1716 reading or writing target state during expression evaluation.
1717 One notable difference to prior behavior is that "print x = 0"
1718 no longer generates a read of x; the value of the assignment is
1719 now always taken directly from the value being assigned.
1721 * GDB now has some support for using labels in the program's source in
1722 linespecs. For instance, you can use "advance label" to continue
1723 execution to a label.
1725 * GDB now has support for reading and writing a new .gdb_index
1726 section. This section holds a fast index of DWARF debugging
1727 information and can be used to greatly speed up GDB startup and
1728 operation. See the documentation for `save gdb-index' for details.
1730 * The "watch" command now accepts an optional "-location" argument.
1731 When used, this causes GDB to watch the memory referred to by the
1732 expression. Such a watchpoint is never deleted due to it going out
1735 * GDB now supports thread debugging of core dumps on GNU/Linux.
1737 GDB now activates thread debugging using the libthread_db library
1738 when debugging GNU/Linux core dumps, similarly to when debugging
1739 live processes. As a result, when debugging a core dump file, GDB
1740 is now able to display pthread_t ids of threads. For example, "info
1741 threads" shows the same output as when debugging the process when it
1742 was live. In earlier releases, you'd see something like this:
1745 * 1 LWP 6780 main () at main.c:10
1747 While now you see this:
1750 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1752 It is also now possible to inspect TLS variables when debugging core
1755 When debugging a core dump generated on a machine other than the one
1756 used to run GDB, you may need to point GDB at the correct
1757 libthread_db library with the "set libthread-db-search-path"
1758 command. See the user manual for more details on this command.
1760 * When natively debugging programs on PowerPC BookE processors running
1761 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1762 which stop execution of the inferior whenever it executes an instruction
1763 at any address within the specified range. See the "PowerPC Embedded"
1764 section in the user manual for more details.
1766 * New features in the GDB remote stub, GDBserver
1768 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1769 and i686 LynxOS (version 5.x).
1771 ** GDBserver is now supported on Blackfin Linux.
1773 * New native configurations
1775 ia64 HP-UX ia64-*-hpux*
1779 Analog Devices, Inc. Blackfin Processor bfin-*
1781 * Ada task switching is now supported on sparc-elf targets when
1782 debugging a program using the Ravenscar Profile. For more information,
1783 see the "Tasking Support when using the Ravenscar Profile" section
1784 in the GDB user manual.
1786 * Guile support was removed.
1788 * New features in the GNU simulator
1790 ** The --map-info flag lists all known core mappings.
1792 ** CFI flashes may be simulated via the "cfi" device.
1794 *** Changes in GDB 7.2
1796 * Shared library support for remote targets by default
1798 When GDB is configured for a generic, non-OS specific target, like
1799 for example, --target=arm-eabi or one of the many *-*-elf targets,
1800 GDB now queries remote stubs for loaded shared libraries using the
1801 `qXfer:libraries:read' packet. Previously, shared library support
1802 was always disabled for such configurations.
1806 ** Argument Dependent Lookup (ADL)
1808 In C++ ADL lookup directs function search to the namespaces of its
1809 arguments even if the namespace has not been imported.
1819 Here the compiler will search for `foo' in the namespace of 'b'
1820 and find A::foo. GDB now supports this. This construct is commonly
1821 used in the Standard Template Library for operators.
1823 ** Improved User Defined Operator Support
1825 In addition to member operators, GDB now supports lookup of operators
1826 defined in a namespace and imported with a `using' directive, operators
1827 defined in the global scope, operators imported implicitly from an
1828 anonymous namespace, and the ADL operators mentioned in the previous
1830 GDB now also supports proper overload resolution for all the previously
1831 mentioned flavors of operators.
1833 ** static const class members
1835 Printing of static const class members that are initialized in the
1836 class definition has been fixed.
1838 * Windows Thread Information Block access.
1840 On Windows targets, GDB now supports displaying the Windows Thread
1841 Information Block (TIB) structure. This structure is visible either
1842 by using the new command `info w32 thread-information-block' or, by
1843 dereferencing the new convenience variable named `$_tlb', a
1844 thread-specific pointer to the TIB. This feature is also supported
1845 when remote debugging using GDBserver.
1847 * Static tracepoints
1849 Static tracepoints are calls in the user program into a tracing
1850 library. One such library is a port of the LTTng kernel tracer to
1851 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1852 When debugging with GDBserver, GDB now supports combining the GDB
1853 tracepoint machinery with such libraries. For example: the user can
1854 use GDB to probe a static tracepoint marker (a call from the user
1855 program into the tracing library) with the new "strace" command (see
1856 "New commands" below). This creates a "static tracepoint" in the
1857 breakpoint list, that can be manipulated with the same feature set
1858 as fast and regular tracepoints. E.g., collect registers, local and
1859 global variables, collect trace state variables, and define
1860 tracepoint conditions. In addition, the user can collect extra
1861 static tracepoint marker specific data, by collecting the new
1862 $_sdata internal variable. When analyzing the trace buffer, you can
1863 inspect $_sdata like any other variable available to GDB. For more
1864 information, see the "Tracepoints" chapter in GDB user manual. New
1865 remote packets have been defined to support static tracepoints, see
1866 the "New remote packets" section below.
1868 * Better reconstruction of tracepoints after disconnected tracing
1870 GDB will attempt to download the original source form of tracepoint
1871 definitions when starting a trace run, and then will upload these
1872 upon reconnection to the target, resulting in a more accurate
1873 reconstruction of the tracepoints that are in use on the target.
1877 You can now exercise direct control over the ways that GDB can
1878 affect your program. For instance, you can disallow the setting of
1879 breakpoints, so that the program can run continuously (assuming
1880 non-stop mode). In addition, the "observer" variable is available
1881 to switch all of the different controls; in observer mode, GDB
1882 cannot affect the target's behavior at all, which is useful for
1883 tasks like diagnosing live systems in the field.
1885 * The new convenience variable $_thread holds the number of the
1888 * New remote packets
1892 Return the address of the Windows Thread Information Block of a given thread.
1896 In response to several of the tracepoint packets, the target may now
1897 also respond with a number of intermediate `qRelocInsn' request
1898 packets before the final result packet, to have GDB handle
1899 relocating an instruction to execute at a different address. This
1900 is particularly useful for stubs that support fast tracepoints. GDB
1901 reports support for this feature in the qSupported packet.
1905 List static tracepoint markers in the target program.
1909 List static tracepoint markers at a given address in the target
1912 qXfer:statictrace:read
1914 Read the static trace data collected (by a `collect $_sdata'
1915 tracepoint action). The remote stub reports support for this packet
1916 to gdb's qSupported query.
1920 Send the current settings of GDB's permission flags.
1924 Send part of the source (textual) form of a tracepoint definition,
1925 which includes location, conditional, and action list.
1927 * The source command now accepts a -s option to force searching for the
1928 script in the source search path even if the script name specifies
1931 * New features in the GDB remote stub, GDBserver
1933 - GDBserver now support tracepoints (including fast tracepoints, and
1934 static tracepoints). The feature is currently supported by the
1935 i386-linux and amd64-linux builds. See the "Tracepoints support
1936 in gdbserver" section in the manual for more information.
1938 GDBserver JIT compiles the tracepoint's conditional agent
1939 expression bytecode into native code whenever possible for low
1940 overhead dynamic tracepoints conditionals. For such tracepoints,
1941 an expression that examines program state is evaluated when the
1942 tracepoint is reached, in order to determine whether to capture
1943 trace data. If the condition is simple and false, processing the
1944 tracepoint finishes very quickly and no data is gathered.
1946 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1947 for static tracepoints support.
1949 - GDBserver now supports x86_64 Windows 64-bit debugging.
1951 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1952 it understands register description.
1954 * The --batch flag now disables pagination and queries.
1956 * X86 general purpose registers
1958 GDB now supports reading/writing byte, word and double-word x86
1959 general purpose registers directly. This means you can use, say,
1960 $ah or $ax to refer, respectively, to the byte register AH and
1961 16-bit word register AX that are actually portions of the 32-bit
1962 register EAX or 64-bit register RAX.
1964 * The `commands' command now accepts a range of breakpoints to modify.
1965 A plain `commands' following a command that creates multiple
1966 breakpoints affects all the breakpoints set by that command. This
1967 applies to breakpoints set by `rbreak', and also applies when a
1968 single `break' command creates multiple breakpoints (e.g.,
1969 breakpoints on overloaded c++ functions).
1971 * The `rbreak' command now accepts a filename specification as part of
1972 its argument, limiting the functions selected by the regex to those
1973 in the specified file.
1975 * Support for remote debugging Windows and SymbianOS shared libraries
1976 from Unix hosts has been improved. Non Windows GDB builds now can
1977 understand target reported file names that follow MS-DOS based file
1978 system semantics, such as file names that include drive letters and
1979 use the backslash character as directory separator. This makes it
1980 possible to transparently use the "set sysroot" and "set
1981 solib-search-path" on Unix hosts to point as host copies of the
1982 target's shared libraries. See the new command "set
1983 target-file-system-kind" described below, and the "Commands to
1984 specify files" section in the user manual for more information.
1988 eval template, expressions...
1989 Convert the values of one or more expressions under the control
1990 of the string template to a command line, and call it.
1992 set target-file-system-kind unix|dos-based|auto
1993 show target-file-system-kind
1994 Set or show the assumed file system kind for target reported file
1997 save breakpoints <filename>
1998 Save all current breakpoint definitions to a file suitable for use
1999 in a later debugging session. To read the saved breakpoint
2000 definitions, use the `source' command.
2002 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2005 info static-tracepoint-markers
2006 Display information about static tracepoint markers in the target.
2008 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2009 Define a static tracepoint by probing a marker at the given
2010 function, line, address, or marker ID.
2014 Enable and disable observer mode.
2016 set may-write-registers on|off
2017 set may-write-memory on|off
2018 set may-insert-breakpoints on|off
2019 set may-insert-tracepoints on|off
2020 set may-insert-fast-tracepoints on|off
2021 set may-interrupt on|off
2022 Set individual permissions for GDB effects on the target. Note that
2023 some of these settings can have undesirable or surprising
2024 consequences, particularly when changed in the middle of a session.
2025 For instance, disabling the writing of memory can prevent
2026 breakpoints from being inserted, cause single-stepping to fail, or
2027 even crash your program, if you disable after breakpoints have been
2028 inserted. However, GDB should not crash.
2030 set record memory-query on|off
2031 show record memory-query
2032 Control whether to stop the inferior if memory changes caused
2033 by an instruction cannot be recorded.
2038 The disassemble command now supports "start,+length" form of two arguments.
2042 ** GDB now provides a new directory location, called the python directory,
2043 where Python scripts written for GDB can be installed. The location
2044 of that directory is <data-directory>/python, where <data-directory>
2045 is the GDB data directory. For more details, see section `Scripting
2046 GDB using Python' in the manual.
2048 ** The GDB Python API now has access to breakpoints, symbols, symbol
2049 tables, program spaces, inferiors, threads and frame's code blocks.
2050 Additionally, GDB Parameters can now be created from the API, and
2051 manipulated via set/show in the CLI.
2053 ** New functions gdb.target_charset, gdb.target_wide_charset,
2054 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2056 ** New exception gdb.GdbError.
2058 ** Pretty-printers are now also looked up in the current program space.
2060 ** Pretty-printers can now be individually enabled and disabled.
2062 ** GDB now looks for names of Python scripts to auto-load in a
2063 special section named `.debug_gdb_scripts', in addition to looking
2064 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2066 * Tracepoint actions were unified with breakpoint commands. In particular,
2067 there are no longer differences in "info break" output for breakpoints and
2068 tracepoints and the "commands" command can be used for both tracepoints and
2069 regular breakpoints.
2073 ARM Symbian arm*-*-symbianelf*
2075 * D language support.
2076 GDB now supports debugging programs written in the D programming
2079 * GDB now supports the extended ptrace interface for PowerPC which is
2080 available since Linux kernel version 2.6.34. This automatically enables
2081 any hardware breakpoints and additional hardware watchpoints available in
2082 the processor. The old ptrace interface exposes just one hardware
2083 watchpoint and no hardware breakpoints.
2085 * GDB is now able to use the Data Value Compare (DVC) register available on
2086 embedded PowerPC processors to implement in hardware simple watchpoint
2087 conditions of the form:
2089 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2091 This works in native GDB running on Linux kernels with the extended ptrace
2092 interface mentioned above.
2094 *** Changes in GDB 7.1
2098 ** Namespace Support
2100 GDB now supports importing of namespaces in C++. This enables the
2101 user to inspect variables from imported namespaces. Support for
2102 namepace aliasing has also been added. So, if a namespace is
2103 aliased in the current scope (e.g. namepace C=A; ) the user can
2104 print variables using the alias (e.g. (gdb) print C::x).
2108 All known bugs relating to the printing of virtual base class were
2109 fixed. It is now possible to call overloaded static methods using a
2114 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2115 and reinterpret_cast<> are now handled by the C++ expression parser.
2119 Xilinx MicroBlaze microblaze-*-*
2124 Xilinx MicroBlaze microblaze
2127 * Multi-program debugging.
2129 GDB now has support for multi-program (a.k.a. multi-executable or
2130 multi-exec) debugging. This allows for debugging multiple inferiors
2131 simultaneously each running a different program under the same GDB
2132 session. See "Debugging Multiple Inferiors and Programs" in the
2133 manual for more information. This implied some user visible changes
2134 in the multi-inferior support. For example, "info inferiors" now
2135 lists inferiors that are not running yet or that have exited
2136 already. See also "New commands" and "New options" below.
2138 * New tracing features
2140 GDB's tracepoint facility now includes several new features:
2142 ** Trace state variables
2144 GDB tracepoints now include support for trace state variables, which
2145 are variables managed by the target agent during a tracing
2146 experiment. They are useful for tracepoints that trigger each
2147 other, so for instance one tracepoint can count hits in a variable,
2148 and then a second tracepoint has a condition that is true when the
2149 count reaches a particular value. Trace state variables share the
2150 $-syntax of GDB convenience variables, and can appear in both
2151 tracepoint actions and condition expressions. Use the "tvariable"
2152 command to create, and "info tvariables" to view; see "Trace State
2153 Variables" in the manual for more detail.
2157 GDB now includes an option for defining fast tracepoints, which
2158 targets may implement more efficiently, such as by installing a jump
2159 into the target agent rather than a trap instruction. The resulting
2160 speedup can be by two orders of magnitude or more, although the
2161 tradeoff is that some program locations on some target architectures
2162 might not allow fast tracepoint installation, for instance if the
2163 instruction to be replaced is shorter than the jump. To request a
2164 fast tracepoint, use the "ftrace" command, with syntax identical to
2165 the regular trace command.
2167 ** Disconnected tracing
2169 It is now possible to detach GDB from the target while it is running
2170 a trace experiment, then reconnect later to see how the experiment
2171 is going. In addition, a new variable disconnected-tracing lets you
2172 tell the target agent whether to continue running a trace if the
2173 connection is lost unexpectedly.
2177 GDB now has the ability to save the trace buffer into a file, and
2178 then use that file as a target, similarly to you can do with
2179 corefiles. You can select trace frames, print data that was
2180 collected in them, and use tstatus to display the state of the
2181 tracing run at the moment that it was saved. To create a trace
2182 file, use "tsave <filename>", and to use it, do "target tfile
2185 ** Circular trace buffer
2187 You can ask the target agent to handle the trace buffer as a
2188 circular buffer, discarding the oldest trace frames to make room for
2189 newer ones, by setting circular-trace-buffer to on. This feature may
2190 not be available for all target agents.
2195 The disassemble command, when invoked with two arguments, now requires
2196 the arguments to be comma-separated.
2199 The info variables command now displays variable definitions. Files
2200 which only declare a variable are not shown.
2203 The source command is now capable of sourcing Python scripts.
2204 This feature is dependent on the debugger being build with Python
2207 Related to this enhancement is also the introduction of a new command
2208 "set script-extension" (see below).
2210 * New commands (for set/show, see "New options" below)
2212 record save [<FILENAME>]
2213 Save a file (in core file format) containing the process record
2214 execution log for replay debugging at a later time.
2216 record restore <FILENAME>
2217 Restore the process record execution log that was saved at an
2218 earlier time, for replay debugging.
2220 add-inferior [-copies <N>] [-exec <FILENAME>]
2223 clone-inferior [-copies <N>] [ID]
2224 Make a new inferior ready to execute the same program another
2225 inferior has loaded.
2230 maint info program-spaces
2231 List the program spaces loaded into GDB.
2233 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2234 show remote interrupt-sequence
2235 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2236 as the sequence to the remote target in order to interrupt the execution.
2237 Ctrl-C is a default. Some system prefers BREAK which is high level of
2238 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2239 Magic SysRq g. It is BREAK signal and character 'g'.
2241 set remote interrupt-on-connect [on | off]
2242 show remote interrupt-on-connect
2243 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2244 remote target when gdb connects to it. This is needed when you debug
2247 set remotebreak [on | off]
2249 Deprecated. Use "set/show remote interrupt-sequence" instead.
2251 tvariable $NAME [ = EXP ]
2252 Create or modify a trace state variable.
2255 List trace state variables and their values.
2257 delete tvariable $NAME ...
2258 Delete one or more trace state variables.
2261 Evaluate the given expressions without collecting anything into the
2262 trace buffer. (Valid in tracepoint actions only.)
2264 ftrace FN / FILE:LINE / *ADDR
2265 Define a fast tracepoint at the given function, line, or address.
2267 * New expression syntax
2269 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2270 GDB now parses 0b101010 identically with 42.
2274 set follow-exec-mode new|same
2275 show follow-exec-mode
2276 Control whether GDB reuses the same inferior across an exec call or
2277 creates a new one. This is useful to be able to restart the old
2278 executable after the inferior having done an exec call.
2280 set default-collect EXPR, ...
2281 show default-collect
2282 Define a list of expressions to be collected at each tracepoint.
2283 This is a useful way to ensure essential items are not overlooked,
2284 such as registers or a critical global variable.
2286 set disconnected-tracing
2287 show disconnected-tracing
2288 If set to 1, the target is instructed to continue tracing if it
2289 loses its connection to GDB. If 0, the target is to stop tracing
2292 set circular-trace-buffer
2293 show circular-trace-buffer
2294 If set to on, the target is instructed to use a circular trace buffer
2295 and discard the oldest trace frames instead of stopping the trace due
2296 to a full trace buffer. If set to off, the trace stops when the buffer
2297 fills up. Some targets may not support this.
2299 set script-extension off|soft|strict
2300 show script-extension
2301 If set to "off", the debugger does not perform any script language
2302 recognition, and all sourced files are assumed to be GDB scripts.
2303 If set to "soft" (the default), files are sourced according to
2304 filename extension, falling back to GDB scripts if the first
2306 If set to "strict", files are sourced according to filename extension.
2308 set ada trust-PAD-over-XVS on|off
2309 show ada trust-PAD-over-XVS
2310 If off, activate a workaround against a bug in the debugging information
2311 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2312 the GCC sources for more information about the GNAT encoding and
2313 PAD types in particular). It is always safe to set this option to
2314 off, but this introduces a slight performance penalty. The default
2317 * Python API Improvements
2319 ** GDB provides the new class gdb.LazyString. This is useful in
2320 some pretty-printing cases. The new method gdb.Value.lazy_string
2321 provides a simple way to create objects of this type.
2323 ** The fields returned by gdb.Type.fields now have an
2324 `is_base_class' attribute.
2326 ** The new method gdb.Type.range returns the range of an array type.
2328 ** The new method gdb.parse_and_eval can be used to parse and
2329 evaluate an expression.
2331 * New remote packets
2334 Define a trace state variable.
2337 Get the current value of a trace state variable.
2340 Set desired tracing behavior upon disconnection.
2343 Set the trace buffer to be linear or circular.
2346 Get data about the tracepoints currently in use.
2350 Process record now works correctly with hardware watchpoints.
2352 Multiple bug fixes have been made to the mips-irix port, making it
2353 much more reliable. In particular:
2354 - Debugging threaded applications is now possible again. Previously,
2355 GDB would hang while starting the program, or while waiting for
2356 the program to stop at a breakpoint.
2357 - Attaching to a running process no longer hangs.
2358 - An error occurring while loading a core file has been fixed.
2359 - Changing the value of the PC register now works again. This fixes
2360 problems observed when using the "jump" command, or when calling
2361 a function from GDB, or even when assigning a new value to $pc.
2362 - With the "finish" and "return" commands, the return value for functions
2363 returning a small array is now correctly printed.
2364 - It is now possible to break on shared library code which gets executed
2365 during a shared library init phase (code executed while executing
2366 their .init section). Previously, the breakpoint would have no effect.
2367 - GDB is now able to backtrace through the signal handler for
2368 non-threaded programs.
2370 PIE (Position Independent Executable) programs debugging is now supported.
2371 This includes debugging execution of PIC (Position Independent Code) shared
2372 libraries although for that, it should be possible to run such libraries as an
2375 *** Changes in GDB 7.0
2377 * GDB now has an interface for JIT compilation. Applications that
2378 dynamically generate code can create symbol files in memory and register
2379 them with GDB. For users, the feature should work transparently, and
2380 for JIT developers, the interface is documented in the GDB manual in the
2381 "JIT Compilation Interface" chapter.
2383 * Tracepoints may now be conditional. The syntax is as for
2384 breakpoints; either an "if" clause appended to the "trace" command,
2385 or the "condition" command is available. GDB sends the condition to
2386 the target for evaluation using the same bytecode format as is used
2387 for tracepoint actions.
2389 * The disassemble command now supports: an optional /r modifier, print the
2390 raw instructions in hex as well as in symbolic form, and an optional /m
2391 modifier to print mixed source+assembly.
2393 * Process record and replay
2395 In a architecture environment that supports ``process record and
2396 replay'', ``process record and replay'' target can record a log of
2397 the process execution, and replay it with both forward and reverse
2400 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2401 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2402 set execution-direction {forward|reverse}, for targets that support
2405 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2406 feature is available with a native GDB running on kernel version
2409 * GDB now has support for multi-byte and wide character sets on the
2410 target. Strings whose character type is wchar_t, char16_t, or
2411 char32_t are now correctly printed. GDB supports wide- and unicode-
2412 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2413 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2414 `printf'. This feature requires iconv to work properly; if your
2415 system does not have a working iconv, GDB can use GNU libiconv. See
2416 the installation instructions for more information.
2418 * GDB now supports automatic retrieval of shared library files from
2419 remote targets. To use this feature, specify a system root that begins
2420 with the `remote:' prefix, either via the `set sysroot' command or via
2421 the `--with-sysroot' configure-time option.
2423 * "info sharedlibrary" now takes an optional regex of libraries to show,
2424 and it now reports if a shared library has no debugging information.
2426 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2427 now complete on file names.
2429 * When completing in expressions, gdb will attempt to limit
2430 completions to allowable structure or union fields, where appropriate.
2431 For instance, consider:
2433 # struct example { int f1; double f2; };
2434 # struct example variable;
2437 If the user types TAB at the end of this command line, the available
2438 completions will be "f1" and "f2".
2440 * Inlined functions are now supported. They show up in backtraces, and
2441 the "step", "next", and "finish" commands handle them automatically.
2443 * GDB now supports the token-splicing (##) and stringification (#)
2444 operators when expanding macros. It also supports variable-arity
2447 * GDB now supports inspecting extra signal information, exported by
2448 the new $_siginfo convenience variable. The feature is currently
2449 implemented on linux ARM, i386 and amd64.
2451 * GDB can now display the VFP floating point registers and NEON vector
2452 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2453 can provide these registers (requires Linux 2.6.30 or later). Remote
2454 and simulator targets may also provide them.
2456 * New remote packets
2459 Search memory for a sequence of bytes.
2462 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2463 operation over reliable transport links. Use of this packet is
2464 controlled by the `set remote noack-packet' command.
2467 Kill the process with the specified process ID. Use this in preference
2468 to `k' when multiprocess protocol extensions are supported.
2471 Obtains additional operating system information
2475 Read or write additional signal information.
2477 * Removed remote protocol undocumented extension
2479 An undocumented extension to the remote protocol's `S' stop reply
2480 packet that permited the stub to pass a process id was removed.
2481 Remote servers should use the `T' stop reply packet instead.
2483 * GDB now supports multiple function calling conventions according to the
2484 DWARF-2 DW_AT_calling_convention function attribute.
2486 * The SH target utilizes the aforementioned change to distinguish between gcc
2487 and Renesas calling convention. It also adds the new CLI commands
2488 `set/show sh calling-convention'.
2490 * GDB can now read compressed debug sections, as produced by GNU gold
2491 with the --compress-debug-sections=zlib flag.
2493 * 64-bit core files are now supported on AIX.
2495 * Thread switching is now supported on Tru64.
2497 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2498 which will be allocated using malloc later in program execution.
2500 * The qXfer:libraries:read remote procotol packet now allows passing a
2501 list of section offsets.
2503 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2504 conditions handling signals delivered during attach or thread creation
2505 have also been fixed.
2507 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2508 From the user's standpoint, all unqualified instances of True and False
2509 are treated as the standard definitions, regardless of context.
2511 * GDB now parses C++ symbol and type names more flexibly. For
2514 template<typename T> class C { };
2517 GDB will now correctly handle all of:
2519 ptype C<char const *>
2520 ptype C<char const*>
2521 ptype C<const char *>
2522 ptype C<const char*>
2524 * New features in the GDB remote stub, gdbserver
2526 - The "--wrapper" command-line argument tells gdbserver to use a
2527 wrapper program to launch programs for debugging.
2529 - On PowerPC and S/390 targets, it is now possible to use a single
2530 gdbserver executable to debug both 32-bit and 64-bit programs.
2531 (This requires gdbserver itself to be built as a 64-bit executable.)
2533 - gdbserver uses the new noack protocol mode for TCP connections to
2534 reduce communications latency, if also supported and enabled in GDB.
2536 - Support for the sparc64-linux-gnu target is now included in
2539 - The amd64-linux build of gdbserver now supports debugging both
2540 32-bit and 64-bit programs.
2542 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2543 now support hardware watchpoints, and will use them automatically
2548 GDB now has support for scripting using Python. Whether this is
2549 available is determined at configure time.
2551 New GDB commands can now be written in Python.
2553 * Ada tasking support
2555 Ada tasks can now be inspected in GDB. The following commands have
2559 Print the list of Ada tasks.
2561 Print detailed information about task number N.
2563 Print the task number of the current task.
2565 Switch the context of debugging to task number N.
2567 * Support for user-defined prefixed commands. The "define" command can
2568 add new commands to existing prefixes, e.g. "target".
2570 * Multi-inferior, multi-process debugging.
2572 GDB now has generalized support for multi-inferior debugging. See
2573 "Debugging Multiple Inferiors" in the manual for more information.
2574 Although availability still depends on target support, the command
2575 set is more uniform now. The GNU/Linux specific multi-forks support
2576 has been migrated to this new framework. This implied some user
2577 visible changes; see "New commands" and also "Removed commands"
2580 * Target descriptions can now describe the target OS ABI. See the
2581 "Target Description Format" section in the user manual for more
2584 * Target descriptions can now describe "compatible" architectures
2585 to indicate that the target can execute applications for a different
2586 architecture in addition to those for the main target architecture.
2587 See the "Target Description Format" section in the user manual for
2590 * Multi-architecture debugging.
2592 GDB now includes general supports for debugging applications on
2593 hybrid systems that use more than one single processor architecture
2594 at the same time. Each such hybrid architecture still requires
2595 specific support to be added. The only hybrid architecture supported
2596 in this version of GDB is the Cell Broadband Engine.
2598 * GDB now supports integrated debugging of Cell/B.E. applications that
2599 use both the PPU and SPU architectures. To enable support for hybrid
2600 Cell/B.E. debugging, you need to configure GDB to support both the
2601 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2602 --enable-targets configure option.
2604 * Non-stop mode debugging.
2606 For some targets, GDB now supports an optional mode of operation in
2607 which you can examine stopped threads while other threads continue
2608 to execute freely. This is referred to as non-stop mode, with the
2609 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2610 section in the user manual for more information.
2612 To be able to support remote non-stop debugging, a remote stub needs
2613 to implement the non-stop mode remote protocol extensions, as
2614 described in the "Remote Non-Stop" section of the user manual. The
2615 GDB remote stub, gdbserver, has been adjusted to support these
2616 extensions on linux targets.
2618 * New commands (for set/show, see "New options" below)
2620 catch syscall [NAME(S) | NUMBER(S)]
2621 Catch system calls. Arguments, which should be names of system
2622 calls or their numbers, mean catch only those syscalls. Without
2623 arguments, every syscall will be caught. When the inferior issues
2624 any of the specified syscalls, GDB will stop and announce the system
2625 call, both when it is called and when its call returns. This
2626 feature is currently available with a native GDB running on the
2627 Linux Kernel, under the following architectures: x86, x86_64,
2628 PowerPC and PowerPC64.
2630 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2632 Search memory for a sequence of bytes.
2634 maint set python print-stack
2635 maint show python print-stack
2636 Show a stack trace when an error is encountered in a Python script.
2639 Invoke CODE by passing it to the Python interpreter.
2644 These allow macros to be defined, undefined, and listed
2648 Show operating system information about processes.
2651 List the inferiors currently under GDB's control.
2654 Switch focus to inferior number NUM.
2657 Detach from inferior number NUM.
2660 Kill inferior number NUM.
2664 set spu stop-on-load
2665 show spu stop-on-load
2666 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2668 set spu auto-flush-cache
2669 show spu auto-flush-cache
2670 Control whether to automatically flush the software-managed cache
2671 during Cell/B.E. debugging.
2673 set sh calling-convention
2674 show sh calling-convention
2675 Control the calling convention used when calling SH target functions.
2678 show debug timestamp
2679 Control display of timestamps with GDB debugging output.
2681 set disassemble-next-line
2682 show disassemble-next-line
2683 Control display of disassembled source lines or instructions when
2686 set remote noack-packet
2687 show remote noack-packet
2688 Set/show the use of remote protocol QStartNoAckMode packet. See above
2689 under "New remote packets."
2691 set remote query-attached-packet
2692 show remote query-attached-packet
2693 Control use of remote protocol `qAttached' (query-attached) packet.
2695 set remote read-siginfo-object
2696 show remote read-siginfo-object
2697 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2700 set remote write-siginfo-object
2701 show remote write-siginfo-object
2702 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2705 set remote reverse-continue
2706 show remote reverse-continue
2707 Control use of remote protocol 'bc' (reverse-continue) packet.
2709 set remote reverse-step
2710 show remote reverse-step
2711 Control use of remote protocol 'bs' (reverse-step) packet.
2713 set displaced-stepping
2714 show displaced-stepping
2715 Control displaced stepping mode. Displaced stepping is a way to
2716 single-step over breakpoints without removing them from the debuggee.
2717 Also known as "out-of-line single-stepping".
2720 show debug displaced
2721 Control display of debugging info for displaced stepping.
2723 maint set internal-error
2724 maint show internal-error
2725 Control what GDB does when an internal error is detected.
2727 maint set internal-warning
2728 maint show internal-warning
2729 Control what GDB does when an internal warning is detected.
2734 Use a wrapper program to launch programs for debugging.
2736 set multiple-symbols (all|ask|cancel)
2737 show multiple-symbols
2738 The value of this variable can be changed to adjust the debugger behavior
2739 when an expression or a breakpoint location contains an ambiguous symbol
2740 name (an overloaded function name, for instance).
2742 set breakpoint always-inserted
2743 show breakpoint always-inserted
2744 Keep breakpoints always inserted in the target, as opposed to inserting
2745 them when resuming the target, and removing them when the target stops.
2746 This option can improve debugger performance on slow remote targets.
2748 set arm fallback-mode (arm|thumb|auto)
2749 show arm fallback-mode
2750 set arm force-mode (arm|thumb|auto)
2752 These commands control how ARM GDB determines whether instructions
2753 are ARM or Thumb. The default for both settings is auto, which uses
2754 the current CPSR value for instructions without symbols; previous
2755 versions of GDB behaved as if "set arm fallback-mode arm".
2757 set disable-randomization
2758 show disable-randomization
2759 Standalone programs run with the virtual address space randomization enabled
2760 by default on some platforms. This option keeps the addresses stable across
2761 multiple debugging sessions.
2765 Control whether other threads are stopped or not when some thread hits
2770 Requests that asynchronous execution is enabled in the target, if available.
2771 In this case, it's possible to resume target in the background, and interact
2772 with GDB while the target is running. "show target-async" displays the
2773 current state of asynchronous execution of the target.
2775 set target-wide-charset
2776 show target-wide-charset
2777 The target-wide-charset is the name of the character set that GDB
2778 uses when printing characters whose type is wchar_t.
2780 set tcp auto-retry (on|off)
2782 set tcp connect-timeout
2783 show tcp connect-timeout
2784 These commands allow GDB to retry failed TCP connections to a remote stub
2785 with a specified timeout period; this is useful if the stub is launched
2786 in parallel with GDB but may not be ready to accept connections immediately.
2788 set libthread-db-search-path
2789 show libthread-db-search-path
2790 Control list of directories which GDB will search for appropriate
2793 set schedule-multiple (on|off)
2794 show schedule-multiple
2795 Allow GDB to resume all threads of all processes or only threads of
2796 the current process.
2800 Use more aggressive caching for accesses to the stack. This improves
2801 performance of remote debugging (particularly backtraces) without
2802 affecting correctness.
2804 set interactive-mode (on|off|auto)
2805 show interactive-mode
2806 Control whether GDB runs in interactive mode (on) or not (off).
2807 When in interactive mode, GDB waits for the user to answer all
2808 queries. Otherwise, GDB does not wait and assumes the default
2809 answer. When set to auto (the default), GDB determines which
2810 mode to use based on the stdin settings.
2815 For program forks, this is replaced by the new more generic `info
2816 inferiors' command. To list checkpoints, you can still use the
2817 `info checkpoints' command, which was an alias for the `info forks'
2821 Replaced by the new `inferior' command. To switch between
2822 checkpoints, you can still use the `restart' command, which was an
2823 alias for the `fork' command.
2826 This is removed, since some targets don't have a notion of
2827 processes. To switch between processes, you can still use the
2828 `inferior' command using GDB's own inferior number.
2831 For program forks, this is replaced by the new more generic `kill
2832 inferior' command. To delete a checkpoint, you can still use the
2833 `delete checkpoint' command, which was an alias for the `delete
2837 For program forks, this is replaced by the new more generic `detach
2838 inferior' command. To detach a checkpoint, you can still use the
2839 `detach checkpoint' command, which was an alias for the `detach
2842 * New native configurations
2844 x86/x86_64 Darwin i[34567]86-*-darwin*
2846 x86_64 MinGW x86_64-*-mingw*
2850 Lattice Mico32 lm32-*
2851 x86 DICOS i[34567]86-*-dicos*
2852 x86_64 DICOS x86_64-*-dicos*
2855 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2856 (mingw32ce) debugging.
2862 These commands were actually not implemented on any target.
2864 *** Changes in GDB 6.8
2866 * New native configurations
2868 NetBSD/hppa hppa*-*netbsd*
2869 Xtensa GNU/Linux xtensa*-*-linux*
2873 NetBSD/hppa hppa*-*-netbsd*
2874 Xtensa GNU/Lunux xtensa*-*-linux*
2876 * Change in command line behavior -- corefiles vs. process ids.
2878 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2879 attaching to process NUMBER fails, GDB no longer attempts to open a
2880 core file named NUMBER. Attaching to a program using the -c option
2881 is no longer supported. Instead, use the '-p' or '--pid' options.
2883 * GDB can now be built as a native debugger for debugging Windows x86
2884 (mingw32) Portable Executable (PE) programs.
2886 * Pending breakpoints no longer change their number when their address
2889 * GDB now supports breakpoints with multiple locations,
2890 including breakpoints on C++ constructors, inside C++ templates,
2891 and in inlined functions.
2893 * GDB's ability to debug optimized code has been improved. GDB more
2894 accurately identifies function bodies and lexical blocks that occupy
2895 more than one contiguous range of addresses.
2897 * Target descriptions can now describe registers for PowerPC.
2899 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2900 registers on PowerPC targets.
2902 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2903 targets even when the libthread_db library is not available.
2905 * The GDB remote stub, gdbserver, now supports the new file transfer
2906 commands (remote put, remote get, and remote delete).
2908 * The GDB remote stub, gdbserver, now supports run and attach in
2909 extended-remote mode.
2911 * hppa*64*-*-hpux11* target broken
2912 The debugger is unable to start a program and fails with the following
2913 error: "Error trying to get information about dynamic linker".
2914 The gdb-6.7 release is also affected.
2916 * GDB now supports the --enable-targets= configure option to allow
2917 building a single GDB executable that supports multiple remote
2918 target architectures.
2920 * GDB now supports debugging C and C++ programs which use the
2921 Decimal Floating Point extension. In addition, the PowerPC target
2922 now has a set of pseudo-registers to inspect decimal float values
2923 stored in two consecutive float registers.
2925 * The -break-insert MI command can optionally create pending
2928 * Improved support for debugging Ada
2929 Many improvements to the Ada language support have been made. These
2931 - Better support for Ada2005 interface types
2932 - Improved handling of arrays and slices in general
2933 - Better support for Taft-amendment types
2934 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2936 - Improved command completion in Ada
2939 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2944 set print frame-arguments (all|scalars|none)
2945 show print frame-arguments
2946 The value of this variable can be changed to control which argument
2947 values should be printed by the debugger when displaying a frame.
2952 Transfer files to and from a remote target, and delete remote files.
2959 Transfer files to and from a remote target, and delete remote files.
2961 * New remote packets
2968 Open, close, read, write, and delete files on the remote system.
2971 Attach to an existing process on the remote system, in extended-remote
2975 Run a new process on the remote system, in extended-remote mode.
2977 *** Changes in GDB 6.7
2979 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2980 bfd, libiberty and opcodes, as revealed by static analysis donated by
2981 Coverity, Inc. (http://scan.coverity.com).
2983 * When looking up multiply-defined global symbols, GDB will now prefer the
2984 symbol definition in the current shared library if it was built using the
2985 -Bsymbolic linker option.
2987 * When the Text User Interface (TUI) is not configured, GDB will now
2988 recognize the -tui command-line option and print a message that the TUI
2991 * The GDB remote stub, gdbserver, now has lower overhead for high
2992 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2994 * GDB for MIPS targets now autodetects whether a remote target provides
2995 32-bit or 64-bit register values.
2997 * Support for C++ member pointers has been improved.
2999 * GDB now understands XML target descriptions, which specify the
3000 target's overall architecture. GDB can read a description from
3001 a local file or over the remote serial protocol.
3003 * Vectors of single-byte data use a new integer type which is not
3004 automatically displayed as character or string data.
3006 * The /s format now works with the print command. It displays
3007 arrays of single-byte integers and pointers to single-byte integers
3010 * Target descriptions can now describe target-specific registers,
3011 for architectures which have implemented the support (currently
3012 only ARM, M68K, and MIPS).
3014 * GDB and the GDB remote stub, gdbserver, now support the XScale
3017 * The GDB remote stub, gdbserver, has been updated to support
3018 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3019 has been rewritten to use the standard GDB remote protocol.
3021 * GDB can now step into C++ functions which are called through thunks.
3023 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3025 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3026 layout. It also supports a TextSeg= and DataSeg= response when only
3027 segment base addresses (rather than offsets) are available.
3029 * The /i format now outputs any trailing branch delay slot instructions
3030 immediately following the last instruction within the count specified.
3032 * The GDB remote protocol "T" stop reply packet now supports a
3033 "library" response. Combined with the new "qXfer:libraries:read"
3034 packet, this response allows GDB to debug shared libraries on targets
3035 where the operating system manages the list of loaded libraries (e.g.
3036 Windows and SymbianOS).
3038 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3039 (DLLs) on Windows and Windows CE targets.
3041 * GDB now supports a faster verification that a .debug file matches its binary
3042 according to its build-id signature, if the signature is present.
3048 Enable or disable hardware flow control (RTS/CTS) on the serial port
3049 when debugging using remote targets.
3051 set mem inaccessible-by-default
3052 show mem inaccessible-by-default
3053 If the target supplies a memory map, for instance via the remote
3054 protocol's "qXfer:memory-map:read" packet, setting this variable
3055 prevents GDB from accessing memory outside the memory map. This
3056 is useful for targets with memory mapped registers or which react
3057 badly to accesses of unmapped address space.
3059 set breakpoint auto-hw
3060 show breakpoint auto-hw
3061 If the target supplies a memory map, for instance via the remote
3062 protocol's "qXfer:memory-map:read" packet, setting this variable
3063 lets GDB use hardware breakpoints automatically for memory regions
3064 where it can not use software breakpoints. This covers both the
3065 "break" command and internal breakpoints used for other commands
3066 including "next" and "finish".
3069 catch exception unhandled
3070 Stop the program execution when Ada exceptions are raised.
3073 Stop the program execution when an Ada assertion failed.
3077 Set an alternate system root for target files. This is a more
3078 general version of "set solib-absolute-prefix", which is now
3079 an alias to "set sysroot".
3082 Provide extended SPU facility status information. This set of
3083 commands is available only when debugging the Cell/B.E. SPU
3086 * New native configurations
3088 OpenBSD/sh sh*-*openbsd*
3091 unset tdesc filename
3093 Use the specified local file as an XML target description, and do
3094 not query the target for its built-in description.
3098 OpenBSD/sh sh*-*-openbsd*
3099 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3100 Toshiba Media Processor mep-elf
3102 * New remote packets
3105 Ignore the specified signals; pass them directly to the debugged program
3106 without stopping other threads or reporting them to GDB.
3108 qXfer:features:read:
3109 Read an XML target description from the target, which describes its
3114 Read or write contents of an spufs file on the target system. These
3115 packets are available only on the Cell/B.E. SPU architecture.
3117 qXfer:libraries:read:
3118 Report the loaded shared libraries. Combined with new "T" packet
3119 response, this packet allows GDB to debug shared libraries on
3120 targets where the operating system manages the list of loaded
3121 libraries (e.g. Windows and SymbianOS).
3125 Support for these obsolete configurations has been removed.
3133 i[34567]86-*-lynxos*
3134 i[34567]86-*-netware*
3135 i[34567]86-*-sco3.2v5*
3136 i[34567]86-*-sco3.2v4*
3138 i[34567]86-*-sysv4.2*
3141 i[34567]86-*-unixware2*
3142 i[34567]86-*-unixware*
3151 * Other removed features
3158 Various m68k-only ROM monitors.
3165 Various Renesas ROM monitors and debugging interfaces for SH and
3170 Support for a Macraigor serial interface to on-chip debugging.
3171 GDB does not directly support the newer parallel or USB
3176 A debug information format. The predecessor to DWARF 2 and
3177 DWARF 3, which are still supported.
3179 Support for the HP aCC compiler on HP-UX/PA-RISC
3181 SOM-encapsulated symbolic debugging information, automatic
3182 invocation of pxdb, and the aCC custom C++ ABI. This does not
3183 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3184 with aCC can still be debugged on an assembly level.
3186 MIPS ".pdr" sections
3188 A MIPS-specific format used to describe stack frame layout
3189 in debugging information.
3193 GDB could work with an older version of Guile to debug
3194 the interpreter and Scheme programs running in it.
3196 set mips stack-arg-size
3197 set mips saved-gpreg-size
3199 Use "set mips abi" to control parameter passing for MIPS.
3201 *** Changes in GDB 6.6
3206 Cell Broadband Engine SPU spu-elf
3208 * GDB can now be configured as a cross-debugger targeting native Windows
3209 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3210 running on a Windows system over TCP/IP to debug Windows programs.
3212 * The GDB remote stub, gdbserver, has been updated to support Windows and
3213 Cygwin debugging. Both single-threaded and multi-threaded programs are
3216 * The "set trust-readonly-sections" command works again. This command was
3217 broken in GDB 6.3, 6.4, and 6.5.
3219 * The "load" command now supports writing to flash memory, if the remote
3220 stub provides the required support.
3222 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3223 longer requires symbolic debug information (e.g. DWARF-2).
3228 unset substitute-path
3229 show substitute-path
3230 Manage a list of substitution rules that GDB uses to rewrite the name
3231 of the directories where the sources are located. This can be useful
3232 for instance when the sources were moved to a different location
3233 between compilation and debugging.
3237 Print each CLI command as it is executed. Each command is prefixed with
3238 a number of `+' symbols representing the nesting depth.
3239 The source command now has a `-v' option to enable the same feature.
3243 The ARM Demon monitor support (RDP protocol, "target rdp").
3245 Kernel Object Display, an embedded debugging feature which only worked with
3246 an obsolete version of Cisco IOS.
3248 The 'set download-write-size' and 'show download-write-size' commands.
3250 * New remote packets
3253 Tell a stub about GDB client features, and request remote target features.
3254 The first feature implemented is PacketSize, which allows the target to
3255 specify the size of packets it can handle - to minimize the number of
3256 packets required and improve performance when connected to a remote
3260 Fetch an OS auxilliary vector from the remote stub. This packet is a
3261 more efficient replacement for qPart:auxv:read.
3263 qXfer:memory-map:read:
3264 Fetch a memory map from the remote stub, including information about
3265 RAM, ROM, and flash memory devices.
3270 Erase and program a flash memory device.
3272 * Removed remote packets
3275 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3276 used it, and only gdbserver implemented it.
3278 *** Changes in GDB 6.5
3282 Renesas M32C/M16C m32c-elf
3284 Morpho Technologies ms1 ms1-elf
3288 init-if-undefined Initialize a convenience variable, but
3289 only if it doesn't already have a value.
3291 The following commands are presently only implemented for native GNU/Linux:
3293 checkpoint Save a snapshot of the program state.
3295 restart <n> Return the program state to a
3296 previously saved state.
3298 info checkpoints List currently saved checkpoints.
3300 delete-checkpoint <n> Delete a previously saved checkpoint.
3302 set|show detach-on-fork Tell gdb whether to detach from a newly
3303 forked process, or to keep debugging it.
3305 info forks List forks of the user program that
3306 are available to be debugged.
3308 fork <n> Switch to debugging one of several
3309 forks of the user program that are
3310 available to be debugged.
3312 delete-fork <n> Delete a fork from the list of forks
3313 that are available to be debugged (and
3314 kill the forked process).
3316 detach-fork <n> Delete a fork from the list of forks
3317 that are available to be debugged (and
3318 allow the process to continue).
3322 Morpho Technologies ms2 ms1-elf
3324 * Improved Windows host support
3326 GDB now builds as a cross debugger hosted on i686-mingw32, including
3327 native console support, and remote communications using either
3328 network sockets or serial ports.
3330 * Improved Modula-2 language support
3332 GDB can now print most types in the Modula-2 syntax. This includes:
3333 basic types, set types, record types, enumerated types, range types,
3334 pointer types and ARRAY types. Procedure var parameters are correctly
3335 printed and hexadecimal addresses and character constants are also
3336 written in the Modula-2 syntax. Best results can be obtained by using
3337 GNU Modula-2 together with the -gdwarf-2 command line option.
3341 The ARM rdi-share module.
3343 The Netware NLM debug server.
3345 *** Changes in GDB 6.4
3347 * New native configurations
3349 OpenBSD/arm arm*-*-openbsd*
3350 OpenBSD/mips64 mips64-*-openbsd*
3354 Morpho Technologies ms1 ms1-elf
3356 * New command line options
3358 --batch-silent As for --batch, but totally silent.
3359 --return-child-result The debugger will exist with the same value
3360 the child (debugged) program exited with.
3361 --eval-command COMMAND, -ex COMMAND
3362 Execute a single GDB CLI command. This may be
3363 specified multiple times and in conjunction
3364 with the --command (-x) option.
3366 * Deprecated commands removed
3368 The following commands, that were deprecated in 2000, have been
3372 set|show arm disassembly-flavor set|show arm disassembler
3373 othernames set arm disassembler
3374 set|show remotedebug set|show debug remote
3375 set|show archdebug set|show debug arch
3376 set|show eventdebug set|show debug event
3379 * New BSD user-level threads support
3381 It is now possible to debug programs using the user-level threads
3382 library on OpenBSD and FreeBSD. Currently supported (target)
3385 FreeBSD/amd64 x86_64-*-freebsd*
3386 FreeBSD/i386 i386-*-freebsd*
3387 OpenBSD/i386 i386-*-openbsd*
3389 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3390 are not yet supported.
3392 * New support for Matsushita MN10300 w/sim added
3393 (Work in progress). mn10300-elf.
3395 * REMOVED configurations and files
3397 VxWorks and the XDR protocol *-*-vxworks
3398 Motorola MCORE mcore-*-*
3399 National Semiconductor NS32000 ns32k-*-*
3401 * New "set print array-indexes" command
3403 After turning this setting "on", GDB prints the index of each element
3404 when displaying arrays. The default is "off" to preserve the previous
3407 * VAX floating point support
3409 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3411 * User-defined command support
3413 In addition to using $arg0..$arg9 for argument passing, it is now possible
3414 to use $argc to determine now many arguments have been passed. See the
3415 section on user-defined commands in the user manual for more information.
3417 *** Changes in GDB 6.3:
3419 * New command line option
3421 GDB now accepts -l followed by a number to set the timeout for remote
3424 * GDB works with GCC -feliminate-dwarf2-dups
3426 GDB now supports a more compact representation of DWARF-2 debug
3427 information using DW_FORM_ref_addr references. These are produced
3428 by GCC with the option -feliminate-dwarf2-dups and also by some
3429 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3430 to use -feliminate-dwarf2-dups.
3432 * Internationalization
3434 When supported by the host system, GDB will be built with
3435 internationalization (libintl). The task of marking up the sources is
3436 continued, we're looking forward to our first translation.
3440 Initial support for debugging programs compiled with the GNAT
3441 implementation of the Ada programming language has been integrated
3442 into GDB. In this release, support is limited to expression evaluation.
3444 * New native configurations
3446 GNU/Linux/m32r m32r-*-linux-gnu
3450 GDB's remote protocol now includes support for the 'p' packet. This
3451 packet is used to fetch individual registers from a remote inferior.
3453 * END-OF-LIFE registers[] compatibility module
3455 GDB's internal register infrastructure has been completely rewritten.
3456 The new infrastructure making possible the implementation of key new
3457 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3460 GDB 6.3 will be the last release to include the the registers[]
3461 compatibility module that allowed out-of-date configurations to
3462 continue to work. This change directly impacts the following
3472 powerpc bdm protocol
3474 Unless there is activity to revive these configurations, they will be
3475 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3477 * OBSOLETE configurations and files
3479 Configurations that have been declared obsolete in this release have
3480 been commented out. Unless there is activity to revive these
3481 configurations, the next release of GDB will have their sources
3482 permanently REMOVED.
3491 *** Changes in GDB 6.2.1:
3493 * MIPS `break main; run' gave an heuristic-fence-post warning
3495 When attempting to run even a simple program, a warning about
3496 heuristic-fence-post being hit would be reported. This problem has
3499 * MIPS IRIX 'long double' crashed GDB
3501 When examining a long double variable, GDB would get a segmentation
3502 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3503 IRIX long double values).
3507 A bug in the VAX stack code was causing problems with the "next"
3508 command. This problem has been fixed.
3510 *** Changes in GDB 6.2:
3512 * Fix for ``many threads''
3514 On GNU/Linux systems that use the NPTL threads library, a program
3515 rapidly creating and deleting threads would confuse GDB leading to the
3518 ptrace: No such process.
3519 thread_db_get_info: cannot get thread info: generic error
3521 This problem has been fixed.
3523 * "-async" and "-noasync" options removed.
3525 Support for the broken "-noasync" option has been removed (it caused
3528 * New ``start'' command.
3530 This command runs the program until the begining of the main procedure.
3532 * New BSD Kernel Data Access Library (libkvm) interface
3534 Using ``target kvm'' it is now possible to debug kernel core dumps and
3535 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3536 platforms. Currently supported (native-only) configurations are:
3538 FreeBSD/amd64 x86_64-*-freebsd*
3539 FreeBSD/i386 i?86-*-freebsd*
3540 NetBSD/i386 i?86-*-netbsd*
3541 NetBSD/m68k m68*-*-netbsd*
3542 NetBSD/sparc sparc-*-netbsd*
3543 OpenBSD/amd64 x86_64-*-openbsd*
3544 OpenBSD/i386 i?86-*-openbsd*
3545 OpenBSD/m68k m68*-openbsd*
3546 OpenBSD/sparc sparc-*-openbsd*
3548 * Signal trampoline code overhauled
3550 Many generic problems with GDB's signal handling code have been fixed.
3551 These include: backtraces through non-contiguous stacks; recognition
3552 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3553 call; backtrace through a signal trampoline; step into and out of
3554 signal handlers; and single-stepping in the signal trampoline.
3556 Please note that kernel bugs are a limiting factor here. These
3557 features have been shown to work on an s390 GNU/Linux system that
3558 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3560 * Cygwin support for DWARF 2 added.
3562 * New native configurations
3564 GNU/Linux/hppa hppa*-*-linux*
3565 OpenBSD/hppa hppa*-*-openbsd*
3566 OpenBSD/m68k m68*-*-openbsd*
3567 OpenBSD/m88k m88*-*-openbsd*
3568 OpenBSD/powerpc powerpc-*-openbsd*
3569 NetBSD/vax vax-*-netbsd*
3570 OpenBSD/vax vax-*-openbsd*
3572 * END-OF-LIFE frame compatibility module
3574 GDB's internal frame infrastructure has been completely rewritten.
3575 The new infrastructure making it possible to support key new features
3576 including DWARF 2 Call Frame Information. To aid in the task of
3577 migrating old configurations to this new infrastructure, a
3578 compatibility module, that allowed old configurations to continue to
3579 work, was also included.
3581 GDB 6.2 will be the last release to include this frame compatibility
3582 module. This change directly impacts the following configurations:
3592 Unless there is activity to revive these configurations, they will be
3593 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3595 * REMOVED configurations and files
3597 Sun 3, running SunOS 3 m68*-*-sunos3*
3598 Sun 3, running SunOS 4 m68*-*-sunos4*
3599 Sun 2, running SunOS 3 m68000-*-sunos3*
3600 Sun 2, running SunOS 4 m68000-*-sunos4*
3601 Motorola 680x0 running LynxOS m68*-*-lynxos*
3602 AT&T 3b1/Unix pc m68*-att-*
3603 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3604 decstation mips-dec-* mips-little-*
3605 riscos mips-*-riscos* mips-*-sysv*
3606 sonymips mips-sony-*
3607 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3609 *** Changes in GDB 6.1.1:
3611 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3613 The TUI (Text-mode User Interface) is now built as part of a default
3614 GDB configuration. It is enabled by either selecting the TUI with the
3615 command line option "-i=tui" or by running the separate "gdbtui"
3616 program. For more information on the TUI, see the manual "Debugging
3619 * Pending breakpoint support (also included in GDB 6.1)
3621 Support has been added to allow you to specify breakpoints in shared
3622 libraries that have not yet been loaded. If a breakpoint location
3623 cannot be found, and the "breakpoint pending" option is set to auto,
3624 GDB queries you if you wish to make the breakpoint pending on a future
3625 shared-library load. If and when GDB resolves the breakpoint symbol,
3626 the pending breakpoint is removed as one or more regular breakpoints
3629 Pending breakpoints are very useful for GCJ Java debugging.
3631 * Fixed ISO-C build problems
3633 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3634 non ISO-C code that stopped them being built using a more strict ISO-C
3635 compiler (e.g., IBM's C compiler).
3637 * Fixed build problem on IRIX 5
3639 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3640 wasn't able to compile compile on an IRIX 5 system.
3642 * Added execute permission to gdb/gdbserver/configure
3644 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3645 permission. This bug would cause configure to fail on a number of
3646 systems (Solaris, IRIX). Ref: server/519.
3648 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3650 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3651 has been updated to use constant array sizes.
3653 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3655 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3656 its generated DWARF Call Frame Info. This encoding was causing GDB to
3657 panic, that panic has been fixed. Ref: gdb/1628.
3659 * Fixed a problem when examining parameters in shared library code.
3661 When examining parameters in optimized shared library code generated
3662 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3663 not available''. GDB now correctly displays the variable's value.
3665 *** Changes in GDB 6.1:
3667 * Removed --with-mmalloc
3669 Support for the mmalloc memory manager has been removed, as it
3670 conflicted with the internal gdb byte cache.
3672 * Changes in AMD64 configurations
3674 The AMD64 target now includes the %cs and %ss registers. As a result
3675 the AMD64 remote protocol has changed; this affects the floating-point
3676 and SSE registers. If you rely on those registers for your debugging,
3677 you should upgrade gdbserver on the remote side.
3679 * Revised SPARC target
3681 The SPARC target has been completely revised, incorporating the
3682 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3683 support for LynxOS and SunOS 4 has been dropped. Calling functions
3684 from within GDB on operating systems with a non-executable stack
3685 (Solaris, OpenBSD) now works.
3689 GDB has a new C++ demangler which does a better job on the mangled
3690 names generated by current versions of g++. It also runs faster, so
3691 with this and other changes gdb should now start faster on large C++
3694 * DWARF 2 Location Expressions
3696 GDB support for location expressions has been extended to support function
3697 arguments and frame bases. Older versions of GDB could crash when they
3700 * C++ nested types and namespaces
3702 GDB's support for nested types and namespaces in C++ has been
3703 improved, especially if you use the DWARF 2 debugging format. (This
3704 is the default for recent versions of GCC on most platforms.)
3705 Specifically, if you have a class "Inner" defined within a class or
3706 namespace "Outer", then GDB realizes that the class's name is
3707 "Outer::Inner", not simply "Inner". This should greatly reduce the
3708 frequency of complaints about not finding RTTI symbols. In addition,
3709 if you are stopped at inside of a function defined within a namespace,
3710 GDB modifies its name lookup accordingly.
3712 * New native configurations
3714 NetBSD/amd64 x86_64-*-netbsd*
3715 OpenBSD/amd64 x86_64-*-openbsd*
3716 OpenBSD/alpha alpha*-*-openbsd*
3717 OpenBSD/sparc sparc-*-openbsd*
3718 OpenBSD/sparc64 sparc64-*-openbsd*
3720 * New debugging protocols
3722 M32R with SDI protocol m32r-*-elf*
3724 * "set prompt-escape-char" command deleted.
3726 The command "set prompt-escape-char" has been deleted. This command,
3727 and its very obscure effet on GDB's prompt, was never documented,
3728 tested, nor mentioned in the NEWS file.
3730 * OBSOLETE configurations and files
3732 Configurations that have been declared obsolete in this release have
3733 been commented out. Unless there is activity to revive these
3734 configurations, the next release of GDB will have their sources
3735 permanently REMOVED.
3737 Sun 3, running SunOS 3 m68*-*-sunos3*
3738 Sun 3, running SunOS 4 m68*-*-sunos4*
3739 Sun 2, running SunOS 3 m68000-*-sunos3*
3740 Sun 2, running SunOS 4 m68000-*-sunos4*
3741 Motorola 680x0 running LynxOS m68*-*-lynxos*
3742 AT&T 3b1/Unix pc m68*-att-*
3743 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3744 decstation mips-dec-* mips-little-*
3745 riscos mips-*-riscos* mips-*-sysv*
3746 sonymips mips-sony-*
3747 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3749 * REMOVED configurations and files
3751 SGI Irix-4.x mips-sgi-irix4 or iris4
3752 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3753 Z8000 simulator z8k-zilog-none or z8ksim
3754 Matsushita MN10200 w/simulator mn10200-*-*
3755 H8/500 simulator h8500-hitachi-hms or h8500hms
3756 HP/PA running BSD hppa*-*-bsd*
3757 HP/PA running OSF/1 hppa*-*-osf*
3758 HP/PA Pro target hppa*-*-pro*
3759 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3760 386BSD i[3456]86-*-bsd*
3761 Sequent family i[3456]86-sequent-sysv4*
3762 i[3456]86-sequent-sysv*
3763 i[3456]86-sequent-bsd*
3764 SPARC running LynxOS sparc-*-lynxos*
3765 SPARC running SunOS 4 sparc-*-sunos4*
3766 Tsqware Sparclet sparclet-*-*
3767 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3769 *** Changes in GDB 6.0:
3773 Support for debugging the Objective-C programming language has been
3774 integrated into GDB.
3776 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3778 DWARF 2's Call Frame Information makes available compiler generated
3779 information that more exactly describes the program's run-time stack.
3780 By using this information, GDB is able to provide more robust stack
3783 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3784 have been updated to use a new backtrace mechanism which includes
3785 DWARF 2 CFI support.
3789 GDB's remote protocol has been extended to include support for hosted
3790 file I/O (where the remote target uses GDB's file system). See GDB's
3791 remote protocol documentation for details.
3793 * All targets using the new architecture framework.
3795 All of GDB's targets have been updated to use the new internal
3796 architecture framework. The way is now open for future GDB releases
3797 to include cross-architecture native debugging support (i386 on amd64,
3800 * GNU/Linux's Thread Local Storage (TLS)
3802 GDB now includes support for for the GNU/Linux implementation of
3803 per-thread variables.
3805 * GNU/Linux's Native POSIX Thread Library (NPTL)
3807 GDB's thread code has been updated to work with either the new
3808 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3810 * Separate debug info.
3812 GDB, in conjunction with BINUTILS, now supports a mechanism for
3813 automatically loading debug information from a separate file. Instead
3814 of shipping full debug and non-debug versions of system libraries,
3815 system integrators can now instead ship just the stripped libraries
3816 and optional debug files.
3818 * DWARF 2 Location Expressions
3820 DWARF 2 Location Expressions allow the compiler to more completely
3821 describe the location of variables (even in optimized code) to the
3824 GDB now includes preliminary support for location expressions (support
3825 for DW_OP_piece is still missing).
3829 A number of long standing bugs that caused GDB to die while starting a
3830 Java application have been fixed. GDB's Java support is now
3831 considered "useable".
3833 * GNU/Linux support for fork, vfork, and exec.
3835 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3836 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3839 * GDB supports logging output to a file
3841 There are two new commands, "set logging" and "show logging", which can be
3842 used to capture GDB's output to a file.
3844 * The meaning of "detach" has changed for gdbserver
3846 The "detach" command will now resume the application, as documented. To
3847 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3850 * d10v, m68hc11 `regs' command deprecated
3852 The `info registers' command has been updated so that it displays the
3853 registers using a format identical to the old `regs' command.
3857 A new command, "maint set profile on/off", has been added. This command can
3858 be used to enable or disable profiling while running GDB, to profile a
3859 session or a set of commands. In addition there is a new configure switch,
3860 "--enable-profiling", which will cause GDB to be compiled with profiling
3861 data, for more informative profiling results.
3863 * Default MI syntax changed to "mi2".
3865 The default MI (machine interface) syntax, enabled by the command line
3866 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3867 "mi1", can be enabled by specifying the option "-i=mi1".
3869 Support for the original "mi0" syntax (included in GDB 5.0) has been
3872 Fix for gdb/192: removed extraneous space when displaying frame level.
3873 Fix for gdb/672: update changelist is now output in mi list format.
3874 Fix for gdb/702: a -var-assign that updates the value now shows up
3875 in a subsequent -var-update.
3877 * New native configurations.
3879 FreeBSD/amd64 x86_64-*-freebsd*
3881 * Multi-arched targets.
3883 HP/PA HPUX11 hppa*-*-hpux*
3884 Renesas M32R/D w/simulator m32r-*-elf*
3886 * OBSOLETE configurations and files
3888 Configurations that have been declared obsolete in this release have
3889 been commented out. Unless there is activity to revive these
3890 configurations, the next release of GDB will have their sources
3891 permanently REMOVED.
3893 Z8000 simulator z8k-zilog-none or z8ksim
3894 Matsushita MN10200 w/simulator mn10200-*-*
3895 H8/500 simulator h8500-hitachi-hms or h8500hms
3896 HP/PA running BSD hppa*-*-bsd*
3897 HP/PA running OSF/1 hppa*-*-osf*
3898 HP/PA Pro target hppa*-*-pro*
3899 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3900 Sequent family i[3456]86-sequent-sysv4*
3901 i[3456]86-sequent-sysv*
3902 i[3456]86-sequent-bsd*
3903 Tsqware Sparclet sparclet-*-*
3904 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3906 * REMOVED configurations and files
3909 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3910 IBM AIX PS/2 i[3456]86-*-aix
3911 i386 running Mach 3.0 i[3456]86-*-mach3*
3912 i386 running Mach i[3456]86-*-mach*
3913 i386 running OSF/1 i[3456]86-*osf1mk*
3914 HP/Apollo 68k Family m68*-apollo*-sysv*,
3916 m68*-hp-bsd*, m68*-hp-hpux*
3917 Argonaut Risc Chip (ARC) arc-*-*
3918 Mitsubishi D30V d30v-*-*
3919 Fujitsu FR30 fr30-*-elf*
3920 OS/9000 i[34]86-*-os9k
3921 I960 with MON960 i960-*-coff
3923 * MIPS $fp behavior changed
3925 The convenience variable $fp, for the MIPS, now consistently returns
3926 the address of the current frame's base. Previously, depending on the
3927 context, $fp could refer to either $sp or the current frame's base
3928 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3929 The GNU Source-Level Debugger''.
3931 *** Changes in GDB 5.3:
3933 * GNU/Linux shared library multi-threaded performance improved.
3935 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3936 `/proc', in preference to `ptrace' for memory reads. This may result
3937 in an improvement in the start-up time of multi-threaded, shared
3938 library applications when run under GDB. One GDB user writes: ``loads
3939 shared libs like mad''.
3941 * ``gdbserver'' now supports multi-threaded applications on some targets
3943 Support for debugging multi-threaded applications which use
3944 the GNU/Linux LinuxThreads package has been added for
3945 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3946 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3948 * GDB now supports C/C++ preprocessor macros.
3950 GDB now expands preprocessor macro invocations in C/C++ expressions,
3951 and provides various commands for showing macro definitions and how
3954 The new command `macro expand EXPRESSION' expands any macro
3955 invocations in expression, and shows the result.
3957 The new command `show macro MACRO-NAME' shows the definition of the
3958 macro named MACRO-NAME, and where it was defined.
3960 Most compilers don't include information about macros in the debugging
3961 information by default. In GCC 3.1, for example, you need to compile
3962 your program with the options `-gdwarf-2 -g3'. If the macro
3963 information is present in the executable, GDB will read it.
3965 * Multi-arched targets.
3967 DEC Alpha (partial) alpha*-*-*
3968 DEC VAX (partial) vax-*-*
3970 National Semiconductor NS32000 (partial) ns32k-*-*
3971 Motorola 68000 (partial) m68k-*-*
3972 Motorola MCORE mcore-*-*
3976 Fujitsu FRV architecture added by Red Hat frv*-*-*
3979 * New native configurations
3981 Alpha NetBSD alpha*-*-netbsd*
3982 SH NetBSD sh*-*-netbsdelf*
3983 MIPS NetBSD mips*-*-netbsd*
3984 UltraSPARC NetBSD sparc64-*-netbsd*
3986 * OBSOLETE configurations and files
3988 Configurations that have been declared obsolete in this release have
3989 been commented out. Unless there is activity to revive these
3990 configurations, the next release of GDB will have their sources
3991 permanently REMOVED.
3993 Mitsubishi D30V d30v-*-*
3994 OS/9000 i[34]86-*-os9k
3995 IBM AIX PS/2 i[3456]86-*-aix
3996 Fujitsu FR30 fr30-*-elf*
3997 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3998 Argonaut Risc Chip (ARC) arc-*-*
3999 i386 running Mach 3.0 i[3456]86-*-mach3*
4000 i386 running Mach i[3456]86-*-mach*
4001 i386 running OSF/1 i[3456]86-*osf1mk*
4002 HP/Apollo 68k Family m68*-apollo*-sysv*,
4004 m68*-hp-bsd*, m68*-hp-hpux*
4005 I960 with MON960 i960-*-coff
4007 * OBSOLETE languages
4009 CHILL, a Pascal like language used by telecommunications companies.
4011 * REMOVED configurations and files
4013 AMD 29k family via UDI a29k-amd-udi, udi29k
4014 A29K VxWorks a29k-*-vxworks
4015 AMD 29000 embedded, using EBMON a29k-none-none
4016 AMD 29000 embedded with COFF a29k-none-coff
4017 AMD 29000 embedded with a.out a29k-none-aout
4019 testsuite/gdb.hp/gdb.threads-hp/ directory
4021 * New command "set max-user-call-depth <nnn>"
4023 This command allows the user to limit the call depth of user-defined
4024 commands. The default is 1024.
4026 * Changes in FreeBSD/i386 native debugging.
4028 Support for the "generate-core-file" has been added.
4030 * New commands "dump", "append", and "restore".
4032 These commands allow data to be copied from target memory
4033 to a bfd-format or binary file (dump and append), and back
4034 from a file into memory (restore).
4036 * Improved "next/step" support on multi-processor Alpha Tru64.
4038 The previous single-step mechanism could cause unpredictable problems,
4039 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4040 of a software single-step mechanism prevents this.
4042 *** Changes in GDB 5.2.1:
4050 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4051 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4052 Fix, by Joel Brobecker imported from mainline.
4054 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4055 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4056 Fix, by Fred Fish, imported from mainline.
4058 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4059 Surprisingly enough, it works now.
4060 By Michal Ludvig, imported from mainline.
4062 i386 hardware watchpoint support:
4063 avoid misses on second run for some targets.
4064 By Pierre Muller, imported from mainline.
4066 *** Changes in GDB 5.2:
4068 * New command "set trust-readonly-sections on[off]".
4070 This command is a hint that tells gdb that read-only sections
4071 really are read-only (ie. that their contents will not change).
4072 In this mode, gdb will go to the object file rather than the
4073 target to read memory from read-only sections (such as ".text").
4074 This can be a significant performance improvement on some
4075 (notably embedded) targets.
4077 * New command "generate-core-file" (or "gcore").
4079 This new gdb command allows the user to drop a core file of the child
4080 process state at any time. So far it's been implemented only for
4081 GNU/Linux and Solaris, but should be relatively easily ported to other
4082 hosts. Argument is core file name (defaults to core.<pid>).
4084 * New command line option
4086 GDB now accepts --pid or -p followed by a process id.
4088 * Change in command line behavior -- corefiles vs. process ids.
4090 There is a subtle behavior in the way in which GDB handles
4091 command line arguments. The first non-flag argument is always
4092 a program to debug, but the second non-flag argument may either
4093 be a corefile or a process id. Previously, GDB would attempt to
4094 open the second argument as a corefile, and if that failed, would
4095 issue a superfluous error message and then attempt to attach it as
4096 a process. Now, if the second argument begins with a non-digit,
4097 it will be treated as a corefile. If it begins with a digit,
4098 GDB will attempt to attach it as a process, and if no such process
4099 is found, will then attempt to open it as a corefile.
4101 * Changes in ARM configurations.
4103 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4104 configuration is fully multi-arch.
4106 * New native configurations
4108 ARM NetBSD arm*-*-netbsd*
4109 x86 OpenBSD i[3456]86-*-openbsd*
4110 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4111 Sparc64 running FreeBSD sparc64-*-freebsd*
4115 Sanyo XStormy16 xstormy16-elf
4117 * OBSOLETE configurations and files
4119 Configurations that have been declared obsolete in this release have
4120 been commented out. Unless there is activity to revive these
4121 configurations, the next release of GDB will have their sources
4122 permanently REMOVED.
4124 AMD 29k family via UDI a29k-amd-udi, udi29k
4125 A29K VxWorks a29k-*-vxworks
4126 AMD 29000 embedded, using EBMON a29k-none-none
4127 AMD 29000 embedded with COFF a29k-none-coff
4128 AMD 29000 embedded with a.out a29k-none-aout
4130 testsuite/gdb.hp/gdb.threads-hp/ directory
4132 * REMOVED configurations and files
4134 TI TMS320C80 tic80-*-*
4136 PowerPC Solaris powerpcle-*-solaris*
4137 PowerPC Windows NT powerpcle-*-cygwin32
4138 PowerPC Netware powerpc-*-netware*
4139 Harris/CXUX m88k m88*-harris-cxux*
4140 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4141 ns32k-utek-sysv* ns32k-utek-*
4142 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4143 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4144 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4145 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4146 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4148 * Changes to command line processing
4150 The new `--args' feature can be used to specify command-line arguments
4151 for the inferior from gdb's command line.
4153 * Changes to key bindings
4155 There is a new `operate-and-get-next' function bound to `C-o'.
4157 *** Changes in GDB 5.1.1
4159 Fix compile problem on DJGPP.
4161 Fix a problem with floating-point registers on the i386 being
4164 Fix to stop GDB crashing on .debug_str debug info.
4166 Numerous documentation fixes.
4168 Numerous testsuite fixes.
4170 *** Changes in GDB 5.1:
4172 * New native configurations
4174 Alpha FreeBSD alpha*-*-freebsd*
4175 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4176 MIPS GNU/Linux mips*-*-linux*
4177 MIPS SGI Irix 6.x mips*-sgi-irix6*
4178 ia64 AIX ia64-*-aix*
4179 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4183 Motorola 68HC11 and 68HC12 m68hc11-elf
4185 UltraSparc running GNU/Linux sparc64-*-linux*
4187 * OBSOLETE configurations and files
4189 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4190 Harris/CXUX m88k m88*-harris-cxux*
4191 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4192 ns32k-utek-sysv* ns32k-utek-*
4193 TI TMS320C80 tic80-*-*
4195 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4196 PowerPC Solaris powerpcle-*-solaris*
4197 PowerPC Windows NT powerpcle-*-cygwin32
4198 PowerPC Netware powerpc-*-netware*
4199 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4200 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4201 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4202 Apple Macintosh (MPW) host N/A
4204 stuff.c (Program to stuff files into a specially prepared space in kdb)
4205 kdb-start.c (Main loop for the standalone kernel debugger)
4207 Configurations that have been declared obsolete in this release have
4208 been commented out. Unless there is activity to revive these
4209 configurations, the next release of GDB will have their sources
4210 permanently REMOVED.
4212 * REMOVED configurations and files
4214 Altos 3068 m68*-altos-*
4215 Convex c1-*-*, c2-*-*
4217 ARM RISCix arm-*-* (as host)
4221 * GDB has been converted to ISO C.
4223 GDB's source code has been converted to ISO C. In particular, the
4224 sources are fully protoized, and rely on standard headers being
4229 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4231 * The MI enabled by default.
4233 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4234 revised and enabled by default. Packages which use GDB as a debugging
4235 engine behind a UI or another front end are encouraged to switch to
4236 using the GDB/MI interface, instead of the old annotations interface
4237 which is now deprecated.
4239 * Support for debugging Pascal programs.
4241 GDB now includes support for debugging Pascal programs. The following
4242 main features are supported:
4244 - Pascal-specific data types such as sets;
4246 - automatic recognition of Pascal sources based on file-name
4249 - Pascal-style display of data types, variables, and functions;
4251 - a Pascal expression parser.
4253 However, some important features are not yet supported.
4255 - Pascal string operations are not supported at all;
4257 - there are some problems with boolean types;
4259 - Pascal type hexadecimal constants are not supported
4260 because they conflict with the internal variables format;
4262 - support for Pascal objects and classes is not full yet;
4264 - unlike Pascal, GDB is case-sensitive for symbol names.
4266 * Changes in completion.
4268 Commands such as `shell', `run' and `set args', which pass arguments
4269 to inferior programs, now complete on file names, similar to what
4270 users expect at the shell prompt.
4272 Commands which accept locations, such as `disassemble', `print',
4273 `breakpoint', `until', etc. now complete on filenames as well as
4274 program symbols. Thus, if you type "break foob TAB", and the source
4275 files linked into the programs include `foobar.c', that file name will
4276 be one of the candidates for completion. However, file names are not
4277 considered for completion after you typed a colon that delimits a file
4278 name from a name of a function in that file, as in "break foo.c:bar".
4280 `set demangle-style' completes on available demangling styles.
4282 * New platform-independent commands:
4284 It is now possible to define a post-hook for a command as well as a
4285 hook that runs before the command. For more details, see the
4286 documentation of `hookpost' in the GDB manual.
4288 * Changes in GNU/Linux native debugging.
4290 Support for debugging multi-threaded programs has been completely
4291 revised for all platforms except m68k and sparc. You can now debug as
4292 many threads as your system allows you to have.
4294 Attach/detach is supported for multi-threaded programs.
4296 Support for SSE registers was added for x86. This doesn't work for
4297 multi-threaded programs though.
4299 * Changes in MIPS configurations.
4301 Multi-arch support is enabled for all MIPS configurations.
4303 GDB can now be built as native debugger on SGI Irix 6.x systems for
4304 debugging n32 executables. (Debugging 64-bit executables is not yet
4307 * Unified support for hardware watchpoints in all x86 configurations.
4309 Most (if not all) native x86 configurations support hardware-assisted
4310 breakpoints and watchpoints in a unified manner. This support
4311 implements debug register sharing between watchpoints, which allows to
4312 put a virtually infinite number of watchpoints on the same address,
4313 and also supports watching regions up to 16 bytes with several debug
4316 The new maintenance command `maintenance show-debug-regs' toggles
4317 debugging print-outs in functions that insert, remove, and test
4318 watchpoints and hardware breakpoints.
4320 * Changes in the DJGPP native configuration.
4322 New command ``info dos sysinfo'' displays assorted information about
4323 the CPU, OS, memory, and DPMI server.
4325 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4326 display information about segment descriptors stored in GDT, LDT, and
4329 New commands ``info dos pde'' and ``info dos pte'' display entries
4330 from Page Directory and Page Tables (for now works with CWSDPMI only).
4331 New command ``info dos address-pte'' displays the Page Table entry for
4332 a given linear address.
4334 GDB can now pass command lines longer than 126 characters to the
4335 program being debugged (requires an update to the libdbg.a library
4336 which is part of the DJGPP development kit).
4338 DWARF2 debug info is now supported.
4340 It is now possible to `step' and `next' through calls to `longjmp'.
4342 * Changes in documentation.
4344 All GDB documentation was converted to GFDL, the GNU Free
4345 Documentation License.
4347 Tracepoints-related commands are now fully documented in the GDB
4350 TUI, the Text-mode User Interface, is now documented in the manual.
4352 Tracepoints-related commands are now fully documented in the GDB
4355 The "GDB Internals" manual now has an index. It also includes
4356 documentation of `ui_out' functions, GDB coding standards, x86
4357 hardware watchpoints, and memory region attributes.
4359 * GDB's version number moved to ``version.in''
4361 The Makefile variable VERSION has been replaced by the file
4362 ``version.in''. People creating GDB distributions should update the
4363 contents of this file.
4367 GUD support is now a standard part of the EMACS distribution.
4369 *** Changes in GDB 5.0:
4371 * Improved support for debugging FP programs on x86 targets
4373 Unified and much-improved support for debugging floating-point
4374 programs on all x86 targets. In particular, ``info float'' now
4375 displays the FP registers in the same format on all x86 targets, with
4376 greater level of detail.
4378 * Improvements and bugfixes in hardware-assisted watchpoints
4380 It is now possible to watch array elements, struct members, and
4381 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4382 on x86 targets no longer erroneously trigger when the address is
4385 * Improvements in the native DJGPP version of GDB
4387 The distribution now includes all the scripts and auxiliary files
4388 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4389 machines ``out of the box''.
4391 The DJGPP version can now debug programs that use signals. It is
4392 possible to catch signals that happened in the debuggee, deliver
4393 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4394 would kill the program being debugged.) Programs that hook hardware
4395 interrupts (keyboard, timer, etc.) can also be debugged.
4397 It is now possible to debug DJGPP programs that redirect their
4398 standard handles or switch them to raw (as opposed to cooked) mode, or
4399 even close them. The command ``run < foo > bar'' works as expected,
4400 and ``info terminal'' reports useful information about the debuggee's
4401 terminal, including raw/cooked mode, redirection, etc.
4403 The DJGPP version now uses termios functions for console I/O, which
4404 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4407 DOS-style file names with drive letters are now fully supported by
4410 It is now possible to debug DJGPP programs that switch their working
4411 directory. It is also possible to rerun the debuggee any number of
4412 times without restarting GDB; thus, you can use the same setup,
4413 breakpoints, etc. for many debugging sessions.
4415 * New native configurations
4417 ARM GNU/Linux arm*-*-linux*
4418 PowerPC GNU/Linux powerpc-*-linux*
4422 Motorola MCore mcore-*-*
4423 x86 VxWorks i[3456]86-*-vxworks*
4424 PowerPC VxWorks powerpc-*-vxworks*
4425 TI TMS320C80 tic80-*-*
4427 * OBSOLETE configurations
4429 Altos 3068 m68*-altos-*
4430 Convex c1-*-*, c2-*-*
4432 ARM RISCix arm-*-* (as host)
4435 Configurations that have been declared obsolete will be commented out,
4436 but the code will be left in place. If there is no activity to revive
4437 these configurations before the next release of GDB, the sources will
4438 be permanently REMOVED.
4440 * Gould support removed
4442 Support for the Gould PowerNode and NP1 has been removed.
4444 * New features for SVR4
4446 On SVR4 native platforms (such as Solaris), if you attach to a process
4447 without first loading a symbol file, GDB will now attempt to locate and
4448 load symbols from the running process's executable file.
4450 * Many C++ enhancements
4452 C++ support has been greatly improved. Overload resolution now works properly
4453 in almost all cases. RTTI support is on the way.
4455 * Remote targets can connect to a sub-program
4457 A popen(3) style serial-device has been added. This device starts a
4458 sub-process (such as a stand-alone simulator) and then communicates
4459 with that. The sub-program to run is specified using the syntax
4460 ``|<program> <args>'' vis:
4462 (gdb) set remotedebug 1
4463 (gdb) target extended-remote |mn10300-elf-sim program-args
4465 * MIPS 64 remote protocol
4467 A long standing bug in the mips64 remote protocol where by GDB
4468 expected certain 32 bit registers (ex SR) to be transfered as 32
4469 instead of 64 bits has been fixed.
4471 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4472 added to provide backward compatibility with older versions of GDB.
4474 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4476 The command ``set remotebinarydownload'' command has been replaced by
4477 ``set remote X-packet''. Other commands in ``set remote'' family
4478 include ``set remote P-packet''.
4480 * Breakpoint commands accept ranges.
4482 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4483 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4484 ``tracepoint passcount'' also accepts a range of tracepoints.
4486 * ``apropos'' command added.
4488 The ``apropos'' command searches through command names and
4489 documentation strings, printing out matches, making it much easier to
4490 try to find a command that does what you are looking for.
4494 A new machine oriented interface (MI) has been added to GDB. This
4495 interface is designed for debug environments running GDB as a separate
4496 process. This is part of the long term libGDB project. See the
4497 "GDB/MI" chapter of the GDB manual for further information. It can be
4498 enabled by configuring with:
4500 .../configure --enable-gdbmi
4502 *** Changes in GDB-4.18:
4504 * New native configurations
4506 HP-UX 10.20 hppa*-*-hpux10.20
4507 HP-UX 11.x hppa*-*-hpux11.0*
4508 M68K GNU/Linux m68*-*-linux*
4512 Fujitsu FR30 fr30-*-elf*
4513 Intel StrongARM strongarm-*-*
4514 Mitsubishi D30V d30v-*-*
4516 * OBSOLETE configurations
4518 Gould PowerNode, NP1 np1-*-*, pn-*-*
4520 Configurations that have been declared obsolete will be commented out,
4521 but the code will be left in place. If there is no activity to revive
4522 these configurations before the next release of GDB, the sources will
4523 be permanently REMOVED.
4527 As a compatibility experiment, GDB's source files buildsym.h and
4528 buildsym.c have been converted to pure standard C, no longer
4529 containing any K&R compatibility code. We believe that all systems in
4530 use today either come with a standard C compiler, or have a GCC port
4531 available. If this is not true, please report the affected
4532 configuration to bug-gdb@gnu.org immediately. See the README file for
4533 information about getting a standard C compiler if you don't have one
4538 GDB now uses readline 2.2.
4540 * set extension-language
4542 You can now control the mapping between filename extensions and source
4543 languages by using the `set extension-language' command. For instance,
4544 you can ask GDB to treat .c files as C++ by saying
4545 set extension-language .c c++
4546 The command `info extensions' lists all of the recognized extensions
4547 and their associated languages.
4549 * Setting processor type for PowerPC and RS/6000
4551 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4552 you can use the `set processor' command to specify what variant of the
4553 PowerPC family you are debugging. The command
4557 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4558 following PowerPC and RS6000 variants:
4560 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4561 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4563 403GC IBM PowerPC 403GC
4564 505 Motorola PowerPC 505
4565 860 Motorola PowerPC 860 or 850
4566 601 Motorola PowerPC 601
4567 602 Motorola PowerPC 602
4568 603 Motorola/IBM PowerPC 603 or 603e
4569 604 Motorola PowerPC 604 or 604e
4570 750 Motorola/IBM PowerPC 750 or 750
4572 At the moment, this command just tells GDB what to name the
4573 special-purpose processor registers. Since almost all the affected
4574 registers are inaccessible to user-level programs, this command is
4575 only useful for remote debugging in its present form.
4579 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4580 more extensive support for HP-UX. Added features include shared
4581 library support, kernel threads and hardware watchpoints for 11.00,
4582 support for HP's ANSI C and C++ compilers, and a compatibility mode
4583 for xdb and dbx commands.
4587 HP's donation includes the new concept of catchpoints, which is a
4588 generalization of the old catch command. On HP-UX, it is now possible
4589 to catch exec, fork, and vfork, as well as library loading.
4591 This means that the existing catch command has changed; its first
4592 argument now specifies the type of catch to be set up. See the
4593 output of "help catch" for a list of catchpoint types.
4595 * Debugging across forks
4597 On HP-UX, you can choose which process to debug when a fork() happens
4602 HP has donated a curses-based terminal user interface (TUI). To get
4603 it, build with --enable-tui. Although this can be enabled for any
4604 configuration, at present it only works for native HP debugging.
4606 * GDB remote protocol additions
4608 A new protocol packet 'X' that writes binary data is now available.
4609 Default behavior is to try 'X', then drop back to 'M' if the stub
4610 fails to respond. The settable variable `remotebinarydownload'
4611 allows explicit control over the use of 'X'.
4613 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4614 full 64-bit address. The command
4616 set remoteaddresssize 32
4618 can be used to revert to the old behaviour. For existing remote stubs
4619 the change should not be noticed, as the additional address information
4622 In order to assist in debugging stubs, you may use the maintenance
4623 command `packet' to send any text string to the stub. For instance,
4625 maint packet heythere
4627 sends the packet "$heythere#<checksum>". Note that it is very easy to
4628 disrupt a debugging session by sending the wrong packet at the wrong
4631 The compare-sections command allows you to compare section data on the
4632 target to what is in the executable file without uploading or
4633 downloading, by comparing CRC checksums.
4635 * Tracing can collect general expressions
4637 You may now collect general expressions at tracepoints. This requires
4638 further additions to the target-side stub; see tracepoint.c and
4639 doc/agentexpr.texi for further details.
4641 * mask-address variable for Mips
4643 For Mips targets, you may control the zeroing of the upper 32 bits of
4644 a 64-bit address by entering `set mask-address on'. This is mainly
4645 of interest to users of embedded R4xxx and R5xxx processors.
4647 * Higher serial baud rates
4649 GDB's serial code now allows you to specify baud rates 57600, 115200,
4650 230400, and 460800 baud. (Note that your host system may not be able
4651 to achieve all of these rates.)
4655 The i960 configuration now includes an initial implementation of a
4656 builtin simulator, contributed by Jim Wilson.
4659 *** Changes in GDB-4.17:
4661 * New native configurations
4663 Alpha GNU/Linux alpha*-*-linux*
4664 Unixware 2.x i[3456]86-unixware2*
4665 Irix 6.x mips*-sgi-irix6*
4666 PowerPC GNU/Linux powerpc-*-linux*
4667 PowerPC Solaris powerpcle-*-solaris*
4668 Sparc GNU/Linux sparc-*-linux*
4669 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4673 Argonaut Risc Chip (ARC) arc-*-*
4674 Hitachi H8/300S h8300*-*-*
4675 Matsushita MN10200 w/simulator mn10200-*-*
4676 Matsushita MN10300 w/simulator mn10300-*-*
4677 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4678 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4679 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4680 Mitsubishi D10V w/simulator d10v-*-*
4681 Mitsubishi M32R/D w/simulator m32r-*-elf*
4682 Tsqware Sparclet sparclet-*-*
4683 NEC V850 w/simulator v850-*-*
4685 * New debugging protocols
4687 ARM with RDI protocol arm*-*-*
4688 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4689 DDB and LSI variants of PMON protocol mips*-*-*
4690 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4691 PowerPC with SDS protocol powerpc{,le}-*-eabi
4692 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4696 All configurations can now understand and use the DWARF 2 debugging
4697 format. The choice is automatic, if the symbol file contains DWARF 2
4702 GDB now includes basic Java language support. This support is
4703 only useful with Java compilers that produce native machine code.
4705 * solib-absolute-prefix and solib-search-path
4707 For SunOS and SVR4 shared libraries, you may now set the prefix for
4708 loading absolute shared library symbol files, and the search path for
4709 locating non-absolute shared library symbol files.
4711 * Live range splitting
4713 GDB can now effectively debug code for which GCC has performed live
4714 range splitting as part of its optimization. See gdb/doc/LRS for
4715 more details on the expected format of the stabs information.
4719 GDB's support for the GNU Hurd, including thread debugging, has been
4720 updated to work with current versions of the Hurd.
4724 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4725 instruction set. ARM GDB automatically detects when Thumb
4726 instructions are in use, and adjusts disassembly and backtracing
4731 GDB's MIPS target configurations now handle the MIP16 16-bit
4736 GDB now includes support for overlays; if an executable has been
4737 linked such that multiple sections are based at the same address, GDB
4738 will decide which section to use for symbolic info. You can choose to
4739 control the decision manually, using overlay commands, or implement
4740 additional target-side support and use "overlay load-target" to bring
4741 in the overlay mapping. Do "help overlay" for more detail.
4745 The command "info symbol <address>" displays information about
4746 the symbol at the specified address.
4750 The standard remote protocol now includes an extension that allows
4751 asynchronous collection and display of trace data. This requires
4752 extensive support in the target-side debugging stub. Tracing mode
4753 includes a new interaction mode in GDB and new commands: see the
4754 file tracepoint.c for more details.
4758 Configurations for embedded MIPS now include a simulator contributed
4759 by Cygnus Solutions. The simulator supports the instruction sets
4760 of most MIPS variants.
4764 Sparc configurations may now include the ERC32 simulator contributed
4765 by the European Space Agency. The simulator is not built into
4766 Sparc targets by default; configure with --enable-sim to include it.
4770 For target configurations that may include multiple variants of a
4771 basic architecture (such as MIPS and SH), you may now set the
4772 architecture explicitly. "set arch" sets, "info arch" lists
4773 the possible architectures.
4775 *** Changes in GDB-4.16:
4777 * New native configurations
4779 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4780 M68K NetBSD m68k-*-netbsd*
4781 PowerPC AIX 4.x powerpc-*-aix*
4782 PowerPC MacOS powerpc-*-macos*
4783 PowerPC Windows NT powerpcle-*-cygwin32
4784 RS/6000 AIX 4.x rs6000-*-aix4*
4788 ARM with RDP protocol arm-*-*
4789 I960 with MON960 i960-*-coff
4790 MIPS VxWorks mips*-*-vxworks*
4791 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4792 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4794 Matra Sparclet sparclet-*-*
4798 The powerpc-eabi configuration now includes the PSIM simulator,
4799 contributed by Andrew Cagney, with assistance from Mike Meissner.
4800 PSIM is a very elaborate model of the PowerPC, including not only
4801 basic instruction set execution, but also details of execution unit
4802 performance and I/O hardware. See sim/ppc/README for more details.
4806 GDB now works with Solaris 2.5.
4808 * Windows 95/NT native
4810 GDB will now work as a native debugger on Windows 95 and Windows NT.
4811 To build it from source, you must use the "gnu-win32" environment,
4812 which uses a DLL to emulate enough of Unix to run the GNU tools.
4813 Further information, binaries, and sources are available at
4814 ftp.cygnus.com, under pub/gnu-win32.
4816 * dont-repeat command
4818 If a user-defined command includes the command `dont-repeat', then the
4819 command will not be repeated if the user just types return. This is
4820 useful if the command is time-consuming to run, so that accidental
4821 extra keystrokes don't run the same command many times.
4823 * Send break instead of ^C
4825 The standard remote protocol now includes an option to send a break
4826 rather than a ^C to the target in order to interrupt it. By default,
4827 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4829 * Remote protocol timeout
4831 The standard remote protocol includes a new variable `remotetimeout'
4832 that allows you to set the number of seconds before GDB gives up trying
4833 to read from the target. The default value is 2.
4835 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4837 By default GDB will automatically keep track of objects as they are
4838 loaded and unloaded by the dynamic linker. By using the command `set
4839 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4840 when shared library events occur, thus allowing you to set breakpoints
4841 in shared libraries which are explicitly loaded by the inferior.
4843 Note this feature does not work on hpux8. On hpux9 you must link
4844 /usr/lib/end.o into your program. This feature should work
4845 automatically on hpux10.
4847 * Irix 5.x hardware watchpoint support
4849 Irix 5 configurations now support the use of hardware watchpoints.
4851 * Mips protocol "SYN garbage limit"
4853 When debugging a Mips target using the `target mips' protocol, you
4854 may set the number of characters that GDB will ignore by setting
4855 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4856 every character. The default value is 1050.
4858 * Recording and replaying remote debug sessions
4860 If you set `remotelogfile' to the name of a file, gdb will write to it
4861 a recording of a remote debug session. This recording may then be
4862 replayed back to gdb using "gdbreplay". See gdbserver/README for
4863 details. This is useful when you have a problem with GDB while doing
4864 remote debugging; you can make a recording of the session and send it
4865 to someone else, who can then recreate the problem.
4867 * Speedups for remote debugging
4869 GDB includes speedups for downloading and stepping MIPS systems using
4870 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4871 and more efficient S-record downloading.
4873 * Memory use reductions and statistics collection
4875 GDB now uses less memory and reports statistics about memory usage.
4876 Try the `maint print statistics' command, for example.
4878 *** Changes in GDB-4.15:
4880 * Psymtabs for XCOFF
4882 The symbol reader for AIX GDB now uses partial symbol tables. This
4883 can greatly improve startup time, especially for large executables.
4885 * Remote targets use caching
4887 Remote targets now use a data cache to speed up communication with the
4888 remote side. The data cache could lead to incorrect results because
4889 it doesn't know about volatile variables, thus making it impossible to
4890 debug targets which use memory mapped I/O devices. `set remotecache
4891 off' turns the the data cache off.
4893 * Remote targets may have threads
4895 The standard remote protocol now includes support for multiple threads
4896 in the target system, using new protocol commands 'H' and 'T'. See
4897 gdb/remote.c for details.
4901 If GDB is configured with `--enable-netrom', then it will include
4902 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4903 acts as though it is a bank of ROM on the target board, but you can
4904 write into it over the network. GDB's support consists only of
4905 support for fast loading into the emulated ROM; to debug, you must use
4906 another protocol, such as standard remote protocol. The usual
4907 sequence is something like
4909 target nrom <netrom-hostname>
4911 target remote <netrom-hostname>:1235
4915 GDB now includes support for the Apple Macintosh, as a host only. It
4916 may be run as either an MPW tool or as a standalone application, and
4917 it can debug through the serial port. All the usual GDB commands are
4918 available, but to the target command, you must supply "serial" as the
4919 device type instead of "/dev/ttyXX". See mpw-README in the main
4920 directory for more information on how to build. The MPW configuration
4921 scripts */mpw-config.in support only a few targets, and only the
4922 mips-idt-ecoff target has been tested.
4926 GDB configuration now uses autoconf. This is not user-visible,
4927 but does simplify configuration and building.
4931 GDB now supports hpux10.
4933 *** Changes in GDB-4.14:
4935 * New native configurations
4937 x86 FreeBSD i[345]86-*-freebsd
4938 x86 NetBSD i[345]86-*-netbsd
4939 NS32k NetBSD ns32k-*-netbsd
4940 Sparc NetBSD sparc-*-netbsd
4944 A29K VxWorks a29k-*-vxworks
4945 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4946 CPU32 EST-300 emulator m68*-*-est*
4947 PowerPC ELF powerpc-*-elf
4950 * Alpha OSF/1 support for procfs
4952 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4953 possible to attach to running processes. As the mounting of the /proc
4954 filesystem is optional on the Alpha, GDB automatically determines
4955 the availability of /proc during startup. This can lead to problems
4956 if /proc is unmounted after GDB has been started.
4958 * Arguments to user-defined commands
4960 User commands may accept up to 10 arguments separated by whitespace.
4961 Arguments are accessed within the user command via $arg0..$arg9. A
4964 print $arg0 + $arg1 + $arg2
4966 To execute the command use:
4969 Defines the command "adder" which prints the sum of its three arguments.
4970 Note the arguments are text substitutions, so they may reference variables,
4971 use complex expressions, or even perform inferior function calls.
4973 * New `if' and `while' commands
4975 This makes it possible to write more sophisticated user-defined
4976 commands. Both commands take a single argument, which is the
4977 expression to evaluate, and must be followed by the commands to
4978 execute, one per line, if the expression is nonzero, the list being
4979 terminated by the word `end'. The `if' command list may include an
4980 `else' word, which causes the following commands to be executed only
4981 if the expression is zero.
4983 * Fortran source language mode
4985 GDB now includes partial support for Fortran 77. It will recognize
4986 Fortran programs and can evaluate a subset of Fortran expressions, but
4987 variables and functions may not be handled correctly. GDB will work
4988 with G77, but does not yet know much about symbols emitted by other
4991 * Better HPUX support
4993 Most debugging facilities now work on dynamic executables for HPPAs
4994 running hpux9 or later. You can attach to running dynamically linked
4995 processes, but by default the dynamic libraries will be read-only, so
4996 for instance you won't be able to put breakpoints in them. To change
4997 that behavior do the following before running the program:
5003 This will cause the libraries to be mapped private and read-write.
5004 To revert to the normal behavior, do this:
5010 You cannot set breakpoints or examine data in the library until after
5011 the library is loaded if the function/data symbols do not have
5014 GDB can now also read debug symbols produced by the HP C compiler on
5015 HPPAs (sorry, no C++, Fortran or 68k support).
5017 * Target byte order now dynamically selectable
5019 You can choose which byte order to use with a target system, via the
5020 commands "set endian big" and "set endian little", and you can see the
5021 current setting by using "show endian". You can also give the command
5022 "set endian auto", in which case GDB will use the byte order
5023 associated with the executable. Currently, only embedded MIPS
5024 configurations support dynamic selection of target byte order.
5026 * New DOS host serial code
5028 This version uses DPMI interrupts to handle buffered I/O, so you
5029 no longer need to run asynctsr when debugging boards connected to
5032 *** Changes in GDB-4.13:
5034 * New "complete" command
5036 This lists all the possible completions for the rest of the line, if it
5037 were to be given as a command itself. This is intended for use by emacs.
5039 * Trailing space optional in prompt
5041 "set prompt" no longer adds a space for you after the prompt you set. This
5042 allows you to set a prompt which ends in a space or one that does not.
5044 * Breakpoint hit counts
5046 "info break" now displays a count of the number of times the breakpoint
5047 has been hit. This is especially useful in conjunction with "ignore"; you
5048 can ignore a large number of breakpoint hits, look at the breakpoint info
5049 to see how many times the breakpoint was hit, then run again, ignoring one
5050 less than that number, and this will get you quickly to the last hit of
5053 * Ability to stop printing at NULL character
5055 "set print null-stop" will cause GDB to stop printing the characters of
5056 an array when the first NULL is encountered. This is useful when large
5057 arrays actually contain only short strings.
5059 * Shared library breakpoints
5061 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5062 breakpoints in shared libraries before the executable is run.
5064 * Hardware watchpoints
5066 There is a new hardware breakpoint for the watch command for sparclite
5067 targets. See gdb/sparclite/hw_breakpoint.note.
5069 Hardware watchpoints are also now supported under GNU/Linux.
5073 Annotations have been added. These are for use with graphical interfaces,
5074 and are still experimental. Currently only gdba.el uses these.
5076 * Improved Irix 5 support
5078 GDB now works properly with Irix 5.2.
5080 * Improved HPPA support
5082 GDB now works properly with the latest GCC and GAS.
5084 * New native configurations
5086 Sequent PTX4 i[34]86-sequent-ptx4
5087 HPPA running OSF/1 hppa*-*-osf*
5088 Atari TT running SVR4 m68*-*-sysv4*
5089 RS/6000 LynxOS rs6000-*-lynxos*
5093 OS/9000 i[34]86-*-os9k
5094 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5097 * Hitachi SH7000 and E7000-PC ICE support
5099 There is now support for communicating with the Hitachi E7000-PC ICE.
5100 This is available automatically when GDB is configured for the SH.
5104 As usual, a variety of small fixes and improvements, both generic
5105 and configuration-specific. See the ChangeLog for more detail.
5107 *** Changes in GDB-4.12:
5109 * Irix 5 is now supported
5113 GDB-4.12 on the HPPA has a number of changes which make it unable
5114 to debug the output from the currently released versions of GCC and
5115 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5116 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5117 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5120 *** Changes in GDB-4.11:
5122 * User visible changes:
5126 The "set remotedebug" option is now consistent between the mips remote
5127 target, remote targets using the gdb-specific protocol, UDI (AMD's
5128 debug protocol for the 29k) and the 88k bug monitor. It is now an
5129 integer specifying a debug level (normally 0 or 1, but 2 means more
5130 debugging info for the mips target).
5132 * DEC Alpha native support
5134 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5135 debug info, but GDB works fairly well with the DEC compiler and should
5136 work with a future GCC release. See the README file for a few
5137 Alpha-specific notes.
5139 * Preliminary thread implementation
5141 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5143 * LynxOS native and target support for 386
5145 This release has been hosted on LynxOS 2.2, and also can be configured
5146 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5149 * Improvements in C++ mangling/demangling.
5151 This release has much better g++ debugging, specifically in name
5152 mangling/demangling, virtual function calls, print virtual table,
5153 call methods, ...etc.
5155 *** Changes in GDB-4.10:
5157 * User visible changes:
5159 Remote debugging using the GDB-specific (`target remote') protocol now
5160 supports the `load' command. This is only useful if you have some
5161 other way of getting the stub to the target system, and you can put it
5162 somewhere in memory where it won't get clobbered by the download.
5164 Filename completion now works.
5166 When run under emacs mode, the "info line" command now causes the
5167 arrow to point to the line specified. Also, "info line" prints
5168 addresses in symbolic form (as well as hex).
5170 All vxworks based targets now support a user settable option, called
5171 vxworks-timeout. This option represents the number of seconds gdb
5172 should wait for responses to rpc's. You might want to use this if
5173 your vxworks target is, perhaps, a slow software simulator or happens
5174 to be on the far side of a thin network line.
5178 This release contains support for using a DEC alpha as a GDB host for
5179 cross debugging. Native alpha debugging is not supported yet.
5182 *** Changes in GDB-4.9:
5186 This is the first GDB release which is accompanied by a matching testsuite.
5187 The testsuite requires installation of dejagnu, which should be available
5188 via ftp from most sites that carry GNU software.
5192 'Cfront' style demangling has had its name changed to 'ARM' style, to
5193 emphasize that it was written from the specifications in the C++ Annotated
5194 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5195 disclaimers, it still generated too much confusion with users attempting to
5196 use gdb with AT&T cfront.
5200 GDB now uses a standard remote interface to a simulator library.
5201 So far, the library contains simulators for the Zilog Z8001/2, the
5202 Hitachi H8/300, H8/500 and Super-H.
5204 * New targets supported
5206 H8/300 simulator h8300-hitachi-hms or h8300hms
5207 H8/500 simulator h8500-hitachi-hms or h8500hms
5208 SH simulator sh-hitachi-hms or sh
5209 Z8000 simulator z8k-zilog-none or z8ksim
5210 IDT MIPS board over serial line mips-idt-ecoff
5212 Cross-debugging to GO32 targets is supported. It requires a custom
5213 version of the i386-stub.c module which is integrated with the
5214 GO32 memory extender.
5216 * New remote protocols
5218 MIPS remote debugging protocol.
5220 * New source languages supported
5222 This version includes preliminary support for Chill, a Pascal like language
5223 used by telecommunications companies. Chill support is also being integrated
5224 into the GNU compiler, but we don't know when it will be publically available.
5227 *** Changes in GDB-4.8:
5229 * HP Precision Architecture supported
5231 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5232 version of this support was available as a set of patches from the
5233 University of Utah. GDB does not support debugging of programs
5234 compiled with the HP compiler, because HP will not document their file
5235 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5236 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5238 Many problems in the preliminary version have been fixed.
5240 * Faster and better demangling
5242 We have improved template demangling and fixed numerous bugs in the GNU style
5243 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5244 character types (wchar_t) are now supported. Demangling of each symbol is now
5245 only done once, and is cached when the symbol table for a file is read in.
5246 This results in a small increase in memory usage for C programs, a moderate
5247 increase in memory usage for C++ programs, and a fantastic speedup in
5250 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5251 from the specifications in the Annotated Reference Manual, which AT&T's
5252 compiler does not actually implement.
5254 * G++ multiple inheritance compiler problem
5256 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5257 inheritance lattices was reworked to properly discover ambiguities. We
5258 recently found an example which causes this new algorithm to fail in a
5259 very subtle way, producing bad debug information for those classes.
5260 The file 'gcc.patch' (in this directory) can be applied to gcc to
5261 circumvent the problem. A future GCC release will contain a complete
5264 The previous G++ debug info problem (mentioned below for the gdb-4.7
5265 release) is fixed in gcc version 2.3.2.
5267 * Improved configure script
5269 The `configure' script will now attempt to guess your system type if
5270 you don't supply a host system type. The old scheme of supplying a
5271 host system triplet is preferable over using this. All the magic is
5272 done in the new `config.guess' script. Examine it for details.
5274 We have also brought our configure script much more in line with the FSF's
5275 version. It now supports the --with-xxx options. In particular,
5276 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5277 The resulting GDB will not be able to read arbitrary object file formats --
5278 only the format ``expected'' to be used on the configured target system.
5279 We hope to make this the default in a future release.
5281 * Documentation improvements
5283 There's new internal documentation on how to modify GDB, and how to
5284 produce clean changes to the code. We implore people to read it
5285 before submitting changes.
5287 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5288 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5289 `info' files are also provided. To build `info' files from scratch,
5290 you will need the latest `makeinfo' release, which will be available in
5291 a future texinfo-X.Y release.
5293 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5294 We're not sure exactly which versions have this problem, but it has
5295 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5296 or better. If that isn't possible, there is a patch in
5297 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5298 around this problem.
5302 GDB now supports array constants that can be used in expressions typed in by
5303 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5304 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5307 The new directory `gdb/sparclite' contains a program that demonstrates
5308 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5310 * New native hosts supported
5312 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5313 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5315 * New targets supported
5317 AMD 29k family via UDI a29k-amd-udi or udi29k
5319 * New file formats supported
5321 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5322 HPUX core files, and SCO 3.2v2 core files.
5326 Attaching to processes now works again; thanks for the many bug reports.
5328 We have also stomped on a bunch of core dumps caused by
5329 printf_filtered("%s") problems.
5331 We eliminated a copyright problem on the rpc and ptrace header files
5332 for VxWorks, which was discovered at the last minute during the 4.7
5333 release. You should now be able to build a VxWorks GDB.
5335 You can now interrupt gdb while an attached process is running. This
5336 will cause the attached process to stop, and give control back to GDB.
5338 We fixed problems caused by using too many file descriptors
5339 for reading symbols from object files and libraries. This was
5340 especially a problem for programs that used many (~100) shared
5343 The `step' command now only enters a subroutine if there is line number
5344 information for the subroutine. Otherwise it acts like the `next'
5345 command. Previously, `step' would enter subroutines if there was
5346 any debugging information about the routine. This avoids problems
5347 when using `cc -g1' on MIPS machines.
5349 * Internal improvements
5351 GDB's internal interfaces have been improved to make it easier to support
5352 debugging of multiple languages in the future.
5354 GDB now uses a common structure for symbol information internally.
5355 Minimal symbols (derived from linkage symbols in object files), partial
5356 symbols (from a quick scan of debug information), and full symbols
5357 contain a common subset of information, making it easier to write
5358 shared code that handles any of them.
5360 * New command line options
5362 We now accept --silent as an alias for --quiet.
5366 The memory-mapped-malloc library is now licensed under the GNU Library
5367 General Public License.
5369 *** Changes in GDB-4.7:
5371 * Host/native/target split
5373 GDB has had some major internal surgery to untangle the support for
5374 hosts and remote targets. Now, when you configure GDB for a remote
5375 target, it will no longer load in all of the support for debugging
5376 local programs on the host. When fully completed and tested, this will
5377 ensure that arbitrary host/target combinations are possible.
5379 The primary conceptual shift is to separate the non-portable code in
5380 GDB into three categories. Host specific code is required any time GDB
5381 is compiled on that host, regardless of the target. Target specific
5382 code relates to the peculiarities of the target, but can be compiled on
5383 any host. Native specific code is everything else: it can only be
5384 built when the host and target are the same system. Child process
5385 handling and core file support are two common `native' examples.
5387 GDB's use of /proc for controlling Unix child processes is now cleaner.
5388 It has been split out into a single module under the `target_ops' vector,
5389 plus two native-dependent functions for each system that uses /proc.
5391 * New hosts supported
5393 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5394 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5395 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5397 * New targets supported
5399 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5400 68030 and CPU32 m68030-*-*, m68332-*-*
5402 * New native hosts supported
5404 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5405 (386bsd is not well tested yet)
5406 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5408 * New file formats supported
5410 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5411 supports reading of `a.out.adobe' object files, which are an a.out
5412 format extended with minimal information about multiple sections.
5416 `show copying' is the same as the old `info copying'.
5417 `show warranty' is the same as `info warrantee'.
5418 These were renamed for consistency. The old commands continue to work.
5420 `info handle' is a new alias for `info signals'.
5422 You can now define pre-command hooks, which attach arbitrary command
5423 scripts to any command. The commands in the hook will be executed
5424 prior to the user's command. You can also create a hook which will be
5425 executed whenever the program stops. See gdb.texinfo.
5429 We now deal with Cfront style name mangling, and can even extract type
5430 info from mangled symbols. GDB can automatically figure out which
5431 symbol mangling style your C++ compiler uses.
5433 Calling of methods and virtual functions has been improved as well.
5437 The crash that occured when debugging Sun Ansi-C compiled binaries is
5438 fixed. This was due to mishandling of the extra N_SO stabs output
5441 We also finally got Ultrix 4.2 running in house, and fixed core file
5442 support, with help from a dozen people on the net.
5444 John M. Farrell discovered that the reason that single-stepping was so
5445 slow on all of the Mips based platforms (primarily SGI and DEC) was
5446 that we were trying to demangle and lookup a symbol used for internal
5447 purposes on every instruction that was being stepped through. Changing
5448 the name of that symbol so that it couldn't be mistaken for a C++
5449 mangled symbol sped things up a great deal.
5451 Rich Pixley sped up symbol lookups in general by getting much smarter
5452 about when C++ symbol mangling is necessary. This should make symbol
5453 completion (TAB on the command line) much faster. It's not as fast as
5454 we'd like, but it's significantly faster than gdb-4.6.
5458 A new user controllable variable 'call_scratch_address' can
5459 specify the location of a scratch area to be used when GDB
5460 calls a function in the target. This is necessary because the
5461 usual method of putting the scratch area on the stack does not work
5462 in systems that have separate instruction and data spaces.
5464 We integrated changes to support the 29k UDI (Universal Debugger
5465 Interface), but discovered at the last minute that we didn't have all
5466 of the appropriate copyright paperwork. We are working with AMD to
5467 resolve this, and hope to have it available soon.
5471 We have sped up the remote serial line protocol, especially for targets
5472 with lots of registers. It now supports a new `expedited status' ('T')
5473 message which can be used in place of the existing 'S' status message.
5474 This allows the remote stub to send only the registers that GDB
5475 needs to make a quick decision about single-stepping or conditional
5476 breakpoints, eliminating the need to fetch the entire register set for
5477 each instruction being stepped through.
5479 The GDB remote serial protocol now implements a write-through cache for
5480 registers, only re-reading the registers if the target has run.
5482 There is also a new remote serial stub for SPARC processors. You can
5483 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5484 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5485 processor with a serial port.
5489 Configure.in files have become much easier to read and modify. A new
5490 `table driven' format makes it more obvious what configurations are
5491 supported, and what files each one uses.
5495 There is a new opcodes library which will eventually contain all of the
5496 disassembly routines and opcode tables. At present, it only contains
5497 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5498 disassembler (binutils/objdump) to share these routines.
5500 The libiberty library is now copylefted under the GNU Library General
5501 Public License. This allows more liberal use, and was done so libg++
5502 can use it. This makes no difference to GDB, since the Library License
5503 grants all the rights from the General Public License.
5507 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5508 reference to the stabs symbol info used by the debugger. It is (as far
5509 as we know) the only published document on this fascinating topic. We
5510 encourage you to read it, compare it to the stabs information on your
5511 system, and send improvements on the document in general (to
5512 bug-gdb@prep.ai.mit.edu).
5514 And, of course, many bugs have been fixed.
5517 *** Changes in GDB-4.6:
5519 * Better support for C++ function names
5521 GDB now accepts as input the "demangled form" of C++ overloaded function
5522 names and member function names, and can do command completion on such names
5523 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5524 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5525 Make use of command completion, it is your friend.
5527 GDB also now accepts a variety of C++ mangled symbol formats. They are
5528 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5529 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5530 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5531 for the list of formats.
5533 * G++ symbol mangling problem
5535 Recent versions of gcc have a bug in how they emit debugging information for
5536 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5537 directory) can be applied to gcc to fix the problem. Alternatively, if you
5538 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5539 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5540 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5543 * New 'maintenance' command
5545 All of the commands related to hacking GDB internals have been moved out of
5546 the main command set, and now live behind the 'maintenance' command. This
5547 can also be abbreviated as 'mt'. The following changes were made:
5549 dump-me -> maintenance dump-me
5550 info all-breakpoints -> maintenance info breakpoints
5551 printmsyms -> maintenance print msyms
5552 printobjfiles -> maintenance print objfiles
5553 printpsyms -> maintenance print psymbols
5554 printsyms -> maintenance print symbols
5556 The following commands are new:
5558 maintenance demangle Call internal GDB demangler routine to
5559 demangle a C++ link name and prints the result.
5560 maintenance print type Print a type chain for a given symbol
5562 * Change to .gdbinit file processing
5564 We now read the $HOME/.gdbinit file before processing the argv arguments
5565 (e.g. reading symbol files or core files). This allows global parameters to
5566 be set, which will apply during the symbol reading. The ./.gdbinit is still
5567 read after argv processing.
5569 * New hosts supported
5571 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5573 GNU/Linux support i386-unknown-linux or linux
5575 We are also including code to support the HP/PA running BSD and HPUX. This
5576 is almost guaranteed not to work, as we didn't have time to test or build it
5577 for this release. We are including it so that the more adventurous (or
5578 masochistic) of you can play with it. We also had major problems with the
5579 fact that the compiler that we got from HP doesn't support the -g option.
5582 * New targets supported
5584 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5586 * More smarts about finding #include files
5588 GDB now remembers the compilation directory for all include files, and for
5589 all files from which C is generated (like yacc and lex sources). This
5590 greatly improves GDB's ability to find yacc/lex sources, and include files,
5591 especially if you are debugging your program from a directory different from
5592 the one that contains your sources.
5594 We also fixed a bug which caused difficulty with listing and setting
5595 breakpoints in include files which contain C code. (In the past, you had to
5596 try twice in order to list an include file that you hadn't looked at before.)
5598 * Interesting infernals change
5600 GDB now deals with arbitrary numbers of sections, where the symbols for each
5601 section must be relocated relative to that section's landing place in the
5602 target's address space. This work was needed to support ELF with embedded
5603 stabs used by Solaris-2.0.
5605 * Bug fixes (of course!)
5607 There have been loads of fixes for the following things:
5608 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5609 i960, stabs, DOS(GO32), procfs, etc...
5611 See the ChangeLog for details.
5613 *** Changes in GDB-4.5:
5615 * New machines supported (host and target)
5617 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5619 SGI Irix-4.x mips-sgi-irix4 or iris4
5621 * New malloc package
5623 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5624 Mmalloc is capable of handling mutiple heaps of memory. It is also
5625 capable of saving a heap to a file, and then mapping it back in later.
5626 This can be used to greatly speedup the startup of GDB by using a
5627 pre-parsed symbol table which lives in a mmalloc managed heap. For
5628 more details, please read mmalloc/mmalloc.texi.
5632 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5633 'help info proc' for details.
5635 * MIPS ecoff symbol table format
5637 The code that reads MIPS symbol table format is now supported on all hosts.
5638 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5641 * File name changes for MS-DOS
5643 Many files in the config directories have been renamed to make it easier to
5644 support GDB on MS-DOSe systems (which have very restrictive file name
5645 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5646 environment) is close to working but has some remaining problems. Note
5647 that debugging of DOS programs is not supported, due to limitations
5648 in the ``operating system'', but it can be used to host cross-debugging.
5650 * Cross byte order fixes
5652 Many fixes have been made to support cross debugging of Sparc and MIPS
5653 targets from hosts whose byte order differs.
5655 * New -mapped and -readnow options
5657 If memory-mapped files are available on your system through the 'mmap'
5658 system call, you can use the -mapped option on the `file' or
5659 `symbol-file' commands to cause GDB to write the symbols from your
5660 program into a reusable file. If the program you are debugging is
5661 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5662 Future GDB debugging sessions will notice the presence of this file,
5663 and will quickly map in symbol information from it, rather than reading
5664 the symbol table from the executable program. Using the '-mapped'
5665 option in a GDB `file' or `symbol-file' command has the same effect as
5666 starting GDB with the '-mapped' command-line option.
5668 You can cause GDB to read the entire symbol table immediately by using
5669 the '-readnow' option with any of the commands that load symbol table
5670 information (or on the GDB command line). This makes the command
5671 slower, but makes future operations faster.
5673 The -mapped and -readnow options are typically combined in order to
5674 build a `fred.syms' file that contains complete symbol information.
5675 A simple GDB invocation to do nothing but build a `.syms' file for future
5678 gdb -batch -nx -mapped -readnow programname
5680 The `.syms' file is specific to the host machine on which GDB is run.
5681 It holds an exact image of GDB's internal symbol table. It cannot be
5682 shared across multiple host platforms.
5684 * longjmp() handling
5686 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5687 siglongjmp() without losing control. This feature has not yet been ported to
5688 all systems. It currently works on many 386 platforms, all MIPS-based
5689 platforms (SGI, DECstation, etc), and Sun3/4.
5693 Preliminary work has been put in to support the new Solaris OS from Sun. At
5694 this time, it can control and debug processes, but it is not capable of
5699 As always, many many bug fixes. The major areas were with g++, and mipsread.
5700 People using the MIPS-based platforms should experience fewer mysterious
5701 crashes and trashed symbol tables.
5703 *** Changes in GDB-4.4:
5705 * New machines supported (host and target)
5707 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5709 BSD Reno on Vax vax-dec-bsd
5710 Ultrix on Vax vax-dec-ultrix
5712 * New machines supported (target)
5714 AMD 29000 embedded, using EBMON a29k-none-none
5718 GDB continues to improve its handling of C++. `References' work better.
5719 The demangler has also been improved, and now deals with symbols mangled as
5720 per the Annotated C++ Reference Guide.
5722 GDB also now handles `stabs' symbol information embedded in MIPS
5723 `ecoff' symbol tables. Since the ecoff format was not easily
5724 extensible to handle new languages such as C++, this appeared to be a
5725 good way to put C++ debugging info into MIPS binaries. This option
5726 will be supported in the GNU C compiler, version 2, when it is
5729 * New features for SVR4
5731 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5732 shared libraries. Debugging dynamically linked programs should present
5733 only minor differences from debugging statically linked programs.
5735 The `info proc' command will print out information about any process
5736 on an SVR4 system (including the one you are debugging). At the moment,
5737 it prints the address mappings of the process.
5739 If you bring up GDB on another SVR4 system, please send mail to
5740 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5742 * Better dynamic linking support in SunOS
5744 Reading symbols from shared libraries which contain debugging symbols
5745 now works properly. However, there remain issues such as automatic
5746 skipping of `transfer vector' code during function calls, which
5747 make it harder to debug code in a shared library, than to debug the
5748 same code linked statically.
5752 GDB is now using the latest `getopt' routines from the FSF. This
5753 version accepts the -- prefix for options with long names. GDB will
5754 continue to accept the old forms (-option and +option) as well.
5755 Various single letter abbreviations for options have been explicity
5756 added to the option table so that they won't get overshadowed in the
5757 future by other options that begin with the same letter.
5761 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5762 Many assorted bugs have been handled. Many more remain to be handled.
5763 See the various ChangeLog files (primarily in gdb and bfd) for details.
5766 *** Changes in GDB-4.3:
5768 * New machines supported (host and target)
5770 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5771 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5772 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5774 * Almost SCO Unix support
5776 We had hoped to support:
5777 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5778 (except for core file support), but we discovered very late in the release
5779 that it has problems with process groups that render gdb unusable. Sorry
5780 about that. I encourage people to fix it and post the fixes.
5782 * Preliminary ELF and DWARF support
5784 GDB can read ELF object files on System V Release 4, and can handle
5785 debugging records for C, in DWARF format, in ELF files. This support
5786 is preliminary. If you bring up GDB on another SVR4 system, please
5787 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5792 GDB now uses the latest `readline' library. One user-visible change
5793 is that two tabs will list possible command completions, which previously
5794 required typing M-? (meta-question mark, or ESC ?).
5798 The `stepi' bug that many of you noticed has been squashed.
5799 Many bugs in C++ have been handled. Many more remain to be handled.
5800 See the various ChangeLog files (primarily in gdb and bfd) for details.
5802 * State of the MIPS world (in case you wondered):
5804 GDB can understand the symbol tables emitted by the compilers
5805 supplied by most vendors of MIPS-based machines, including DEC. These
5806 symbol tables are in a format that essentially nobody else uses.
5808 Some versions of gcc come with an assembler post-processor called
5809 mips-tfile. This program is required if you want to do source-level
5810 debugging of gcc-compiled programs. I believe FSF does not ship
5811 mips-tfile with gcc version 1, but it will eventually come with gcc
5814 Debugging of g++ output remains a problem. g++ version 1.xx does not
5815 really support it at all. (If you're lucky, you should be able to get
5816 line numbers and stack traces to work, but no parameters or local
5817 variables.) With some work it should be possible to improve the
5820 When gcc version 2 is released, you will have somewhat better luck.
5821 However, even then you will get confusing results for inheritance and
5824 We will eventually provide full debugging of g++ output on
5825 DECstations. This will probably involve some kind of stabs-in-ecoff
5826 encapulation, but the details have not been worked out yet.
5829 *** Changes in GDB-4.2:
5831 * Improved configuration
5833 Only one copy of `configure' exists now, and it is not self-modifying.
5834 Porting BFD is simpler.
5838 The `step' and `next' commands now only stop at the first instruction
5839 of a source line. This prevents the multiple stops that used to occur
5840 in switch statements, for-loops, etc. `Step' continues to stop if a
5841 function that has debugging information is called within the line.
5845 Lots of small bugs fixed. More remain.
5847 * New host supported (not target)
5849 Intel 386 PC clone running Mach i386-none-mach
5852 *** Changes in GDB-4.1:
5854 * Multiple source language support
5856 GDB now has internal scaffolding to handle several source languages.
5857 It determines the type of each source file from its filename extension,
5858 and will switch expression parsing and number formatting to match the
5859 language of the function in the currently selected stack frame.
5860 You can also specifically set the language to be used, with
5861 `set language c' or `set language modula-2'.
5865 GDB now has preliminary support for the GNU Modula-2 compiler,
5866 currently under development at the State University of New York at
5867 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5868 continue through the fall of 1991 and into 1992.
5870 Other Modula-2 compilers are currently not supported, and attempting to
5871 debug programs compiled with them will likely result in an error as the
5872 symbol table is read. Feel free to work on it, though!
5874 There are hooks in GDB for strict type checking and range checking,
5875 in the `Modula-2 philosophy', but they do not currently work.
5879 GDB can now write to executable and core files (e.g. patch
5880 a variable's value). You must turn this switch on, specify
5881 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5882 by assigning a new value to a variable. Modifications take
5885 * Automatic SunOS shared library reading
5887 When you run your program, GDB automatically determines where its
5888 shared libraries (if any) have been loaded, and reads their symbols.
5889 The `share' command is no longer needed. This also works when
5890 examining core files.
5894 You can specify the number of lines that the `list' command shows.
5897 * New machines supported (host and target)
5899 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5900 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5901 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5903 * New hosts supported (not targets)
5905 IBM RT/PC: romp-ibm-aix or rtpc
5907 * New targets supported (not hosts)
5909 AMD 29000 embedded with COFF a29k-none-coff
5910 AMD 29000 embedded with a.out a29k-none-aout
5911 Ultracomputer remote kernel debug a29k-nyu-kern
5913 * New remote interfaces
5919 *** Changes in GDB-4.0:
5923 Wide output is wrapped at good places to make the output more readable.
5925 Gdb now supports cross-debugging from a host machine of one type to a
5926 target machine of another type. Communication with the target system
5927 is over serial lines. The ``target'' command handles connecting to the
5928 remote system; the ``load'' command will download a program into the
5929 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5930 also supports debugging of realtime processes running under VxWorks,
5931 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5932 stub on the target system.
5934 New CPUs supported include the AMD 29000 and Intel 960.
5936 GDB now reads object files and symbol tables via a ``binary file''
5937 library, which allows a single copy of GDB to debug programs of multiple
5938 object file types such as a.out and coff.
5940 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5941 refcard.dvi and refcard.ps are available to format it).
5944 * Control-Variable user interface simplified
5946 All variables that control the operation of the debugger can be set
5947 by the ``set'' command, and displayed by the ``show'' command.
5949 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5950 ``Show prompt'' produces the response:
5951 Gdb's prompt is new-gdb=>.
5953 What follows are the NEW set commands. The command ``help set'' will
5954 print a complete list of old and new set commands. ``help set FOO''
5955 will give a longer description of the variable FOO. ``show'' will show
5956 all of the variable descriptions and their current settings.
5958 confirm on/off: Enables warning questions for operations that are
5959 hard to recover from, e.g. rerunning the program while
5960 it is already running. Default is ON.
5962 editing on/off: Enables EMACS style command line editing
5963 of input. Previous lines can be recalled with
5964 control-P, the current line can be edited with control-B,
5965 you can search for commands with control-R, etc.
5968 history filename NAME: NAME is where the gdb command history
5969 will be stored. The default is .gdb_history,
5970 or the value of the environment variable
5973 history size N: The size, in commands, of the command history. The
5974 default is 256, or the value of the environment variable
5977 history save on/off: If this value is set to ON, the history file will
5978 be saved after exiting gdb. If set to OFF, the
5979 file will not be saved. The default is OFF.
5981 history expansion on/off: If this value is set to ON, then csh-like
5982 history expansion will be performed on
5983 command line input. The default is OFF.
5985 radix N: Sets the default radix for input and output. It can be set
5986 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5987 in the current radix, so "set radix 10" is always a no-op.
5989 height N: This integer value is the number of lines on a page. Default
5990 is 24, the current `stty rows'' setting, or the ``li#''
5991 setting from the termcap entry matching the environment
5994 width N: This integer value is the number of characters on a line.
5995 Default is 80, the current `stty cols'' setting, or the ``co#''
5996 setting from the termcap entry matching the environment
5999 Note: ``set screensize'' is obsolete. Use ``set height'' and
6000 ``set width'' instead.
6002 print address on/off: Print memory addresses in various command displays,
6003 such as stack traces and structure values. Gdb looks
6004 more ``symbolic'' if you turn this off; it looks more
6005 ``machine level'' with it on. Default is ON.
6007 print array on/off: Prettyprint arrays. New convenient format! Default
6010 print demangle on/off: Print C++ symbols in "source" form if on,
6013 print asm-demangle on/off: Same, for assembler level printouts
6016 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6019 * Support for Epoch Environment.
6021 The epoch environment is a version of Emacs v18 with windowing. One
6022 new command, ``inspect'', is identical to ``print'', except that if you
6023 are running in the epoch environment, the value is printed in its own
6027 * Support for Shared Libraries
6029 GDB can now debug programs and core files that use SunOS shared libraries.
6030 Symbols from a shared library cannot be referenced
6031 before the shared library has been linked with the program (this
6032 happens after you type ``run'' and before the function main() is entered).
6033 At any time after this linking (including when examining core files
6034 from dynamically linked programs), gdb reads the symbols from each
6035 shared library when you type the ``sharedlibrary'' command.
6036 It can be abbreviated ``share''.
6038 sharedlibrary REGEXP: Load shared object library symbols for files
6039 matching a unix regular expression. No argument
6040 indicates to load symbols for all shared libraries.
6042 info sharedlibrary: Status of loaded shared libraries.
6047 A watchpoint stops execution of a program whenever the value of an
6048 expression changes. Checking for this slows down execution
6049 tremendously whenever you are in the scope of the expression, but is
6050 quite useful for catching tough ``bit-spreader'' or pointer misuse
6051 problems. Some machines such as the 386 have hardware for doing this
6052 more quickly, and future versions of gdb will use this hardware.
6054 watch EXP: Set a watchpoint (breakpoint) for an expression.
6056 info watchpoints: Information about your watchpoints.
6058 delete N: Deletes watchpoint number N (same as breakpoints).
6059 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6060 enable N: Re-enables watchpoint number N (same as breakpoints).
6063 * C++ multiple inheritance
6065 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6068 * C++ exception handling
6070 Gdb now supports limited C++ exception handling. Besides the existing
6071 ability to breakpoint on an exception handler, gdb can breakpoint on
6072 the raising of an exception (before the stack is peeled back to the
6075 catch FOO: If there is a FOO exception handler in the dynamic scope,
6076 set a breakpoint to catch exceptions which may be raised there.
6077 Multiple exceptions (``catch foo bar baz'') may be caught.
6079 info catch: Lists all exceptions which may be caught in the
6080 current stack frame.
6083 * Minor command changes
6085 The command ``call func (arg, arg, ...)'' now acts like the print
6086 command, except it does not print or save a value if the function's result
6087 is void. This is similar to dbx usage.
6089 The ``up'' and ``down'' commands now always print the frame they end up
6090 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6091 frames without printing.
6093 * New directory command
6095 'dir' now adds directories to the FRONT of the source search path.
6096 The path starts off empty. Source files that contain debug information
6097 about the directory in which they were compiled can be found even
6098 with an empty path; Sun CC and GCC include this information. If GDB can't
6099 find your source file in the current directory, type "dir .".
6101 * Configuring GDB for compilation
6103 For normal use, type ``./configure host''. See README or gdb.texinfo
6106 GDB now handles cross debugging. If you are remotely debugging between
6107 two different machines, type ``./configure host -target=targ''.
6108 Host is the machine where GDB will run; targ is the machine
6109 where the program that you are debugging will run.