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 * Support for Sun's version of the "stabs" debug file format has been removed.
12 * GDB now honors the content of the file /proc/PID/coredump_filter
13 (PID is the process ID) on GNU/Linux systems. This file can be used
14 to specify the types of memory mappings that will be included in a
15 corefile. For more information, please refer to the manual page of
16 "core(5)". GDB also has a new command: "set use-coredump-filter
17 on|off". It allows to set whether GDB will read the content of the
18 /proc/PID/coredump_filter file when generating a corefile.
20 * The "info os" command on GNU/Linux can now display information on
22 "info os cpus" Listing of all cpus/cores on the system
24 * GDB has two new commands: "set serial parity odd|even|none" and
25 "show serial parity". These allows to set or show parity for the
28 * The "info source" command now displays the producer string if it was
29 present in the debug info. This typically includes the compiler version
30 and may include things like its command line arguments.
32 * The "info dll", an alias of the "info sharedlibrary" command,
33 is now available on all platforms.
35 * Directory names supplied to the "set sysroot" commands may be
36 prefixed with "target:" to tell GDB to access shared libraries from
37 the target system, be it local or remote. This replaces the prefix
38 "remote:". The default sysroot has been changed from "" to
39 "target:". "remote:" is automatically converted to "target:" for
40 backward compatibility.
42 * The system root specified by "set sysroot" will be prepended to the
43 filename of the main executable (if reported to GDB as absolute by
44 the operating system) when starting processes remotely, and when
45 attaching to already-running local or remote processes.
47 * GDB now supports automatic location and retrieval of executable
48 files from remote targets. Remote debugging can now be initiated
49 using only a "target remote" or "target extended-remote" command
50 (no "set sysroot" or "file" commands are required). See "New remote
53 * The "dump" command now supports verilog hex format.
55 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
57 * On GNU/Linux, GDB and gdbserver are now able to access executable
58 and shared library files without a "set sysroot" command when
59 attaching to processes running in different mount namespaces from
60 the debugger. This makes it possible to attach to processes in
61 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
62 See "New remote packets" below.
64 * The "tui reg" command now provides completion for all of the
65 available register groups, including target specific groups.
67 * The HISTSIZE environment variable is no longer read when determining
68 the size of GDB's command history. GDB now instead reads the dedicated
69 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
70 disables truncation of command history. Non-numeric values of GDBHISTSIZE
75 ** Memory ports can now be unbuffered.
79 ** gdb.Objfile objects have a new attribute "username",
80 which is the name of the objfile as specified by the user,
81 without, for example, resolving symlinks.
82 ** You can now write frame unwinders in Python.
83 ** gdb.Type objects have a new method "optimized_out",
84 returning optimized out gdb.Value instance of this type.
85 ** gdb.Value objects have new methods "reference_value" and
86 "const_value" which return a reference to the value and a
87 "const" version of the value respectively.
91 maint print symbol-cache
92 Print the contents of the symbol cache.
94 maint print symbol-cache-statistics
95 Print statistics of symbol cache usage.
97 maint flush-symbol-cache
98 Flush the contents of the symbol cache.
102 Start branch trace recording using Branch Trace Store (BTS) format.
105 Evaluate expression by using the compiler and print result.
109 Explicit commands for enabling and disabling tui mode.
112 set mpx bound on i386 and amd64
113 Support for bound table investigation on Intel(R) MPX enabled applications.
118 Renamed from "set debug dwarf2-die".
120 Renamed from "show debug dwarf2-die".
123 Renamed from "set debug dwarf2-read".
124 show debug dwarf-read
125 Renamed from "show debug dwarf2-read".
127 maint set dwarf always-disassemble
128 Renamed from "maint set dwarf2 always-disassemble".
129 maint show dwarf always-disassemble
130 Renamed from "maint show dwarf2 always-disassemble".
132 maint set dwarf max-cache-age
133 Renamed from "maint set dwarf2 max-cache-age".
134 maint show dwarf max-cache-age
135 Renamed from "maint show dwarf2 max-cache-age".
138 show debug dwarf-line
139 Control display of debugging info regarding DWARF line processing.
143 Set the maximum number of candidates to be considered during
144 completion. The default value is 200. This limit allows GDB
145 to avoid generating large completion lists, the computation of
146 which can cause the debugger to become temporarily unresponsive.
148 maint set symbol-cache-size
149 maint show symbol-cache-size
150 Control the size of the symbol cache.
152 set|show record btrace bts buffer-size
153 Set and show the size of the ring buffer used for branch tracing in
155 The obtained size may differ from the requested size. Use "info
156 record" to see the obtained buffer size.
158 set debug linux-namespaces
159 show debug linux-namespaces
160 Control display of debugging info regarding Linux namespaces.
162 * The command 'thread apply all' can now support new option '-ascending'
163 to call its specified command for all threads in ascending order.
165 * Python/Guile scripting
167 ** GDB now supports auto-loading of Python/Guile scripts contained in the
168 special section named `.debug_gdb_scripts'.
172 qXfer:btrace-conf:read
173 Return the branch trace configuration for the current thread.
175 Qbtrace-conf:bts:size
176 Set the requested ring buffer size for branch tracing in BTS format.
179 Indicates a memory breakpoint instruction was executed, irrespective
180 of whether it was GDB that planted the breakpoint or the breakpoint
181 is hardcoded in the program. This is required for correct non-stop
185 Indicates the target stopped for a hardware breakpoint. This is
186 required for correct non-stop mode operation.
189 Return information about files on the remote system.
192 Return the full absolute name of the file that was executed to
193 create a process running on the remote system.
196 Select the filesystem on which vFile: operations with filename
197 arguments will operate. This is required for GDB to be able to
198 access files on remote targets where the remote stub does not
199 share a common filesystem with the inferior(s).
202 Indicates that a fork system call was executed.
205 Indicates that a vfork system call was executed.
207 vforkdone stop reason
208 Indicates that a vfork child of the specified process has executed
209 an exec or exit, allowing the vfork parent to resume execution.
211 fork-events and vfork-events features in qSupported
212 The qSupported packet allows GDB to request support for fork and
213 vfork events using new 'gdbfeatures' fork-events and vfork-events,
214 and the qSupported response can contain the corresponding
215 'stubfeatures'. Set and show commands can be used to display
216 whether these features are enabled.
218 * Extended-remote fork events
220 ** GDB now has support for fork events on extended-remote Linux
221 targets. For targets with Linux kernels 2.5.60 and later, this
222 enables follow-fork-mode and detach-on-fork for both fork and
223 vfork, as well as fork and vfork catchpoints.
225 * The info record command now shows the recording format and the
226 branch tracing configuration for the current thread when using
227 the btrace record target.
228 For the BTS format, it shows the ring buffer size.
230 * GDB now has support for DTrace USDT (Userland Static Defined
231 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
233 * GDB now supports access to vector registers on S/390 GNU/Linux
236 * Removed command line options
238 -xdb HP-UX XDB compatibility mode.
240 * Removed targets and native configurations
242 HP/PA running HP-UX hppa*-*-hpux*
243 Itanium running HP-UX ia64-*-hpux*
245 *** Changes in GDB 7.9.1
249 ** Xmethods can now specify a result type.
251 *** Changes in GDB 7.9
253 * GDB now supports hardware watchpoints on x86 GNU Hurd.
257 ** You can now access frame registers from Python scripts.
258 ** New attribute 'producer' for gdb.Symtab objects.
259 ** gdb.Objfile objects have a new attribute "progspace",
260 which is the gdb.Progspace object of the containing program space.
261 ** gdb.Objfile objects have a new attribute "owner".
262 ** gdb.Objfile objects have a new attribute "build_id",
263 which is the build ID generated when the file was built.
264 ** gdb.Objfile objects have a new method "add_separate_debug_file".
265 ** A new event "gdb.clear_objfiles" has been added, triggered when
266 selecting a new file to debug.
267 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
268 ** New function gdb.lookup_objfile.
270 New events which are triggered when GDB modifies the state of the
273 ** gdb.events.inferior_call_pre: Function call is about to be made.
274 ** gdb.events.inferior_call_post: Function call has just been made.
275 ** gdb.events.memory_changed: A memory location has been altered.
276 ** gdb.events.register_changed: A register has been altered.
278 * New Python-based convenience functions:
280 ** $_caller_is(name [, number_of_frames])
281 ** $_caller_matches(regexp [, number_of_frames])
282 ** $_any_caller_is(name [, number_of_frames])
283 ** $_any_caller_matches(regexp [, number_of_frames])
285 * GDB now supports the compilation and injection of source code into
286 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
287 to compile the source code to object code, and if successful, inject
288 and execute that code within the current context of the inferior.
289 Currently the C language is supported. The commands used to
290 interface with this new feature are:
292 compile code [-raw|-r] [--] [source code]
293 compile file [-raw|-r] filename
297 demangle [-l language] [--] name
298 Demangle "name" in the specified language, or the current language
299 if elided. This command is renamed from the "maint demangle" command.
300 The latter is kept as a no-op to avoid "maint demangle" being interpreted
301 as "maint demangler-warning".
303 queue-signal signal-name-or-number
304 Queue a signal to be delivered to the thread when it is resumed.
306 add-auto-load-scripts-directory directory
307 Add entries to the list of directories from which to load auto-loaded
310 maint print user-registers
311 List all currently available "user" registers.
313 compile code [-r|-raw] [--] [source code]
314 Compile, inject, and execute in the inferior the executable object
315 code produced by compiling the provided source code.
317 compile file [-r|-raw] filename
318 Compile and inject into the inferior the executable object code
319 produced by compiling the source code stored in the filename
322 * On resume, GDB now always passes the signal the program had stopped
323 for to the thread the signal was sent to, even if the user changed
324 threads before resuming. Previously GDB would often (but not
325 always) deliver the signal to the thread that happens to be current
328 * Conversely, the "signal" command now consistently delivers the
329 requested signal to the current thread. GDB now asks for
330 confirmation if the program had stopped for a signal and the user
331 switched threads meanwhile.
333 * "breakpoint always-inserted" modes "off" and "auto" merged.
335 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
336 won't remove breakpoints from the target until all threads stop,
337 even in non-stop mode. The "auto" mode has been removed, and "off"
338 is now the default mode.
342 set debug symbol-lookup
343 show debug symbol-lookup
344 Control display of debugging info regarding symbol lookup.
348 ** The -list-thread-groups command outputs an exit-code field for
349 inferiors that have exited.
353 MIPS SDE mips*-sde*-elf*
357 Support for these obsolete configurations has been removed.
359 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
360 SGI Irix-5.x mips-*-irix5*
361 SGI Irix-6.x mips-*-irix6*
362 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
363 VAX running Ultrix vax-*-ultrix*
365 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
366 and "assf"), have been removed. Use the "sharedlibrary" command, or
367 its alias "share", instead.
369 *** Changes in GDB 7.8
371 * New command line options
374 This is an alias for the --data-directory option.
376 * GDB supports printing and modifying of variable length automatic arrays
377 as specified in ISO C99.
379 * The ARM simulator now supports instruction level tracing
380 with or without disassembly.
384 GDB now has support for scripting using Guile. Whether this is
385 available is determined at configure time.
386 Guile version 2.0 or greater is required.
387 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
389 * New commands (for set/show, see "New options" below)
393 Invoke CODE by passing it to the Guile interpreter.
397 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
399 info auto-load guile-scripts [regexp]
400 Print the list of automatically loaded Guile scripts.
402 * The source command is now capable of sourcing Guile scripts.
403 This feature is dependent on the debugger being built with Guile support.
407 set print symbol-loading (off|brief|full)
408 show print symbol-loading
409 Control whether to print informational messages when loading symbol
410 information for a file. The default is "full", but when debugging
411 programs with large numbers of shared libraries the amount of output
414 set guile print-stack (none|message|full)
415 show guile print-stack
416 Show a stack trace when an error is encountered in a Guile script.
418 set auto-load guile-scripts (on|off)
419 show auto-load guile-scripts
420 Control auto-loading of Guile script files.
422 maint ada set ignore-descriptive-types (on|off)
423 maint ada show ignore-descriptive-types
424 Control whether the debugger should ignore descriptive types in Ada
425 programs. The default is not to ignore the descriptive types. See
426 the user manual for more details on descriptive types and the intended
427 usage of this option.
429 set auto-connect-native-target
431 Control whether GDB is allowed to automatically connect to the
432 native target for the run, attach, etc. commands when not connected
433 to any target yet. See also "target native" below.
435 set record btrace replay-memory-access (read-only|read-write)
436 show record btrace replay-memory-access
437 Control what memory accesses are allowed during replay.
439 maint set target-async (on|off)
440 maint show target-async
441 This controls whether GDB targets operate in synchronous or
442 asynchronous mode. Normally the default is asynchronous, if it is
443 available; but this can be changed to more easily debug problems
444 occurring only in synchronous mode.
446 set mi-async (on|off)
448 Control whether MI asynchronous mode is preferred. This supersedes
449 "set target-async" of previous GDB versions.
451 * "set target-async" is deprecated as a CLI option and is now an alias
452 for "set mi-async" (only puts MI into async mode).
454 * Background execution commands (e.g., "c&", "s&", etc.) are now
455 possible ``out of the box'' if the target supports them. Previously
456 the user would need to explicitly enable the possibility with the
457 "set target-async on" command.
459 * New features in the GDB remote stub, GDBserver
461 ** New option --debug-format=option1[,option2,...] allows one to add
462 additional text to each output. At present only timestamps
463 are supported: --debug-format=timestamps.
464 Timestamps can also be turned on with the
465 "monitor set debug-format timestamps" command from GDB.
467 * The 'record instruction-history' command now starts counting instructions
468 at one. This also affects the instruction ranges reported by the
469 'record function-call-history' command when given the /i modifier.
471 * The command 'record function-call-history' supports a new modifier '/c' to
472 indent the function names based on their call stack depth.
473 The fields for the '/i' and '/l' modifier have been reordered.
474 The source line range is now prefixed with 'at'.
475 The instruction range is now prefixed with 'inst'.
476 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
477 "record instruction-history" and "list" commands.
479 * The ranges given as arguments to the 'record function-call-history' and
480 'record instruction-history' commands are now inclusive.
482 * The btrace record target now supports the 'record goto' command.
483 For locations inside the execution trace, the back trace is computed
484 based on the information stored in the execution trace.
486 * The btrace record target supports limited reverse execution and replay.
487 The target does not record data and therefore does not allow reading
490 * The "catch syscall" command now works on s390*-linux* targets.
492 * The "compare-sections" command is no longer specific to target
493 remote. It now works with all targets.
495 * All native targets are now consistently called "native".
496 Consequently, the "target child", "target GNU", "target djgpp",
497 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
498 commands have been replaced with "target native". The QNX/NTO port
499 leaves the "procfs" target in place and adds a "native" target for
500 consistency with other ports. The impact on users should be minimal
501 as these commands previously either throwed an error, or were
502 no-ops. The target's name is visible in the output of the following
503 commands: "help target", "info target", "info files", "maint print
506 * The "target native" command now connects to the native target. This
507 can be used to launch native programs even when "set
508 auto-connect-native-target" is set to off.
510 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.
512 * Support for Intel(R) AVX-512 registers on GNU/Linux.
513 Support displaying and modifying Intel(R) AVX-512 registers
514 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
518 qXfer:btrace:read's annex
519 The qXfer:btrace:read packet supports a new annex 'delta' to read
520 branch trace incrementally.
524 ** Valid Python operations on gdb.Value objects representing
525 structs/classes invoke the corresponding overloaded operators if
527 ** New `Xmethods' feature in the Python API. Xmethods are
528 additional methods or replacements for existing methods of a C++
529 class. This feature is useful for those cases where a method
530 defined in C++ source code could be inlined or optimized out by
531 the compiler, making it unavailable to GDB.
534 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
536 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
537 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
538 its alias "share", instead.
540 * The commands "set remotebaud" and "show remotebaud" are no longer
541 supported. Use "set serial baud" and "show serial baud" (respectively)
546 ** A new option "-gdb-set mi-async" replaces "-gdb-set
547 target-async". The latter is left as a deprecated alias of the
548 former for backward compatibility. If the target supports it,
549 CLI background execution commands are now always possible by
550 default, independently of whether the frontend stated a
551 preference for asynchronous execution with "-gdb-set mi-async".
552 Previously "-gdb-set target-async off" affected both MI execution
553 commands and CLI execution commands.
555 *** Changes in GDB 7.7
557 * Improved support for process record-replay and reverse debugging on
558 arm*-linux* targets. Support for thumb32 and syscall instruction
559 recording has been added.
561 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
563 * GDB now supports Fission DWP file format version 2.
564 http://gcc.gnu.org/wiki/DebugFission
566 * New convenience function "$_isvoid", to check whether an expression
567 is void. A void expression is an expression where the type of the
568 result is "void". For example, some convenience variables may be
569 "void" when evaluated (e.g., "$_exitcode" before the execution of
570 the program being debugged; or an undefined convenience variable).
571 Another example, when calling a function whose return type is
574 * The "maintenance print objfiles" command now takes an optional regexp.
576 * The "catch syscall" command now works on arm*-linux* targets.
578 * GDB now consistently shows "<not saved>" when printing values of
579 registers the debug info indicates have not been saved in the frame
580 and there's nowhere to retrieve them from
581 (callee-saved/call-clobbered registers):
586 (gdb) info registers rax
589 Before, the former would print "<optimized out>", and the latter
590 "*value not available*".
592 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
597 ** Frame filters and frame decorators have been added.
598 ** Temporary breakpoints are now supported.
599 ** Line tables representation has been added.
600 ** New attribute 'parent_type' for gdb.Field objects.
601 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
602 ** New attribute 'name' for gdb.Type objects.
606 Nios II ELF nios2*-*-elf
607 Nios II GNU/Linux nios2*-*-linux
608 Texas Instruments MSP430 msp430*-*-elf
610 * Removed native configurations
612 Support for these a.out NetBSD and OpenBSD obsolete configurations has
613 been removed. ELF variants of these configurations are kept supported.
615 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
616 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
617 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
618 i[34567]86-*-openbsd3.[0-3]
619 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
620 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
621 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
625 Like "catch throw", but catches a re-thrown exception.
627 Renamed from old "maint check-symtabs".
629 Perform consistency checks on symtabs.
631 Expand symtabs matching an optional regexp.
634 Display the details of GDB configure-time options.
636 maint set|show per-command
637 maint set|show per-command space
638 maint set|show per-command time
639 maint set|show per-command symtab
640 Enable display of per-command gdb resource usage.
642 remove-symbol-file FILENAME
643 remove-symbol-file -a ADDRESS
644 Remove a symbol file added via add-symbol-file. The file to remove
645 can be identified by its filename or by an address that lies within
646 the boundaries of this symbol file in memory.
649 info exceptions REGEXP
650 Display the list of Ada exceptions defined in the program being
651 debugged. If provided, only the exceptions whose names match REGEXP
656 set debug symfile off|on
658 Control display of debugging info regarding reading symbol files and
659 symbol tables within those files
661 set print raw frame-arguments
662 show print raw frame-arguments
663 Set/show whether to print frame arguments in raw mode,
664 disregarding any defined pretty-printers.
666 set remote trace-status-packet
667 show remote trace-status-packet
668 Set/show the use of remote protocol qTStatus packet.
672 Control display of debugging messages related to Nios II targets.
676 Control whether target-assisted range stepping is enabled.
678 set startup-with-shell
679 show startup-with-shell
680 Specifies whether Unix child processes are started via a shell or
685 Use the target memory cache for accesses to the code segment. This
686 improves performance of remote debugging (particularly disassembly).
688 * You can now use a literal value 'unlimited' for options that
689 interpret 0 or -1 as meaning "unlimited". E.g., "set
690 trace-buffer-size unlimited" is now an alias for "set
691 trace-buffer-size -1" and "set height unlimited" is now an alias for
694 * The "set debug symtab-create" debugging option of GDB has been changed to
695 accept a verbosity level. 0 means "off", 1 provides basic debugging
696 output, and values of 2 or greater provides more verbose output.
698 * New command-line options
700 Display the details of GDB configure-time options.
702 * The command 'tsave' can now support new option '-ctf' to save trace
703 buffer in Common Trace Format.
705 * Newly installed $prefix/bin/gcore acts as a shell interface for the
708 * GDB now implements the the C++ 'typeid' operator.
710 * The new convenience variable $_exception holds the exception being
711 thrown or caught at an exception-related catchpoint.
713 * The exception-related catchpoints, like "catch throw", now accept a
714 regular expression which can be used to filter exceptions by type.
716 * The new convenience variable $_exitsignal is automatically set to
717 the terminating signal number when the program being debugged dies
718 due to an uncaught signal.
722 ** All MI commands now accept an optional "--language" option.
723 Support for this feature can be verified by using the "-list-features"
724 command, which should contain "language-option".
726 ** The new command -info-gdb-mi-command allows the user to determine
727 whether a GDB/MI command is supported or not.
729 ** The "^error" result record returned when trying to execute an undefined
730 GDB/MI command now provides a variable named "code" whose content is the
731 "undefined-command" error code. Support for this feature can be verified
732 by using the "-list-features" command, which should contain
733 "undefined-command-error-code".
735 ** The -trace-save MI command can optionally save trace buffer in Common
738 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
740 ** The command -data-list-register-values now accepts an optional
741 "--skip-unavailable" option. When used, only the available registers
744 ** The new command -trace-frame-collected dumps collected variables,
745 computed expressions, tvars, memory and registers in a traceframe.
747 ** The commands -stack-list-locals, -stack-list-arguments and
748 -stack-list-variables now accept an option "--skip-unavailable".
749 When used, only the available locals or arguments are displayed.
751 ** The -exec-run command now accepts an optional "--start" option.
752 When used, the command follows the same semantics as the "start"
753 command, stopping the program's execution at the start of its
754 main subprogram. Support for this feature can be verified using
755 the "-list-features" command, which should contain
756 "exec-run-start-option".
758 ** The new commands -catch-assert and -catch-exceptions insert
759 catchpoints stopping the program when Ada exceptions are raised.
761 ** The new command -info-ada-exceptions provides the equivalent of
762 the new "info exceptions" command.
764 * New system-wide configuration scripts
765 A GDB installation now provides scripts suitable for use as system-wide
766 configuration scripts for the following systems:
770 * GDB now supports target-assigned range stepping with remote targets.
771 This improves the performance of stepping source lines by reducing
772 the number of control packets from/to GDB. See "New remote packets"
775 * GDB now understands the element 'tvar' in the XML traceframe info.
776 It has the id of the collected trace state variables.
778 * On S/390 targets that provide the transactional-execution feature,
779 the program interruption transaction diagnostic block (TDB) is now
780 represented as a number of additional "registers" in GDB.
786 The vCont packet supports a new 'r' action, that tells the remote
787 stub to step through an address range itself, without GDB
788 involvemement at each single-step.
790 qXfer:libraries-svr4:read's annex
791 The previously unused annex of the qXfer:libraries-svr4:read packet
792 is now used to support passing an argument list. The remote stub
793 reports support for this argument list to GDB's qSupported query.
794 The defined arguments are "start" and "prev", used to reduce work
795 necessary for library list updating, resulting in significant
798 * New features in the GDB remote stub, GDBserver
800 ** GDBserver now supports target-assisted range stepping. Currently
801 enabled on x86/x86_64 GNU/Linux targets.
803 ** GDBserver now adds element 'tvar' in the XML in the reply to
804 'qXfer:traceframe-info:read'. It has the id of the collected
805 trace state variables.
807 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
810 * New 'z' formatter for printing and examining memory, this displays the
811 value as hexadecimal zero padded on the left to the size of the type.
813 * GDB can now use Windows x64 unwinding data.
815 * The "set remotebaud" command has been replaced by "set serial baud".
816 Similarly, "show remotebaud" has been replaced by "show serial baud".
817 The "set remotebaud" and "show remotebaud" commands are still available
818 to provide backward compatibility with older versions of GDB.
820 *** Changes in GDB 7.6
822 * Target record has been renamed to record-full.
823 Record/replay is now enabled with the "record full" command.
824 This also affects settings that are associated with full record/replay
825 that have been moved from "set/show record" to "set/show record full":
827 set|show record full insn-number-max
828 set|show record full stop-at-limit
829 set|show record full memory-query
831 * A new record target "record-btrace" has been added. The new target
832 uses hardware support to record the control-flow of a process. It
833 does not support replaying the execution, but it implements the
834 below new commands for investigating the recorded execution log.
835 This new recording method can be enabled using:
839 The "record-btrace" target is only available on Intel Atom processors
840 and requires a Linux kernel 2.6.32 or later.
842 * Two new commands have been added for record/replay to give information
843 about the recorded execution without having to replay the execution.
844 The commands are only supported by "record btrace".
846 record instruction-history prints the execution history at
847 instruction granularity
849 record function-call-history prints the execution history at
852 * New native configurations
854 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
855 FreeBSD/powerpc powerpc*-*-freebsd
856 x86_64/Cygwin x86_64-*-cygwin*
857 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
861 ARM AArch64 aarch64*-*-elf
862 ARM AArch64 GNU/Linux aarch64*-*-linux
863 Lynx 178 PowerPC powerpc-*-lynx*178
864 x86_64/Cygwin x86_64-*-cygwin*
865 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
867 * If the configured location of system.gdbinit file (as given by the
868 --with-system-gdbinit option at configure time) is in the
869 data-directory (as specified by --with-gdb-datadir at configure
870 time) or in one of its subdirectories, then GDB will look for the
871 system-wide init file in the directory specified by the
872 --data-directory command-line option.
874 * New command line options:
876 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
877 other initialization files, unlike -nx which disables all of them.
879 * Removed command line options
881 -epoch This was used by the gdb mode in Epoch, an ancient fork of
884 * The 'ptype' and 'whatis' commands now accept an argument to control
887 * 'info proc' now works on some core files.
891 ** Vectors can be created with gdb.Type.vector.
893 ** Python's atexit.register now works in GDB.
895 ** Types can be pretty-printed via a Python API.
897 ** Python 3 is now supported (in addition to Python 2.4 or later)
899 ** New class gdb.Architecture exposes GDB's internal representation
900 of architecture in the Python API.
902 ** New method Frame.architecture returns the gdb.Architecture object
903 corresponding to the frame's architecture.
905 * New Python-based convenience functions:
907 ** $_memeq(buf1, buf2, length)
908 ** $_streq(str1, str2)
910 ** $_regex(str, regex)
912 * The 'cd' command now defaults to using '~' (the home directory) if not
915 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
916 default for GCC since November 2000.
918 * The command 'forward-search' can now be abbreviated as 'fo'.
920 * The command 'info tracepoints' can now display 'installed on target'
921 or 'not installed on target' for each non-pending location of tracepoint.
923 * New configure options
925 --enable-libmcheck/--disable-libmcheck
926 By default, development versions are built with -lmcheck on hosts
927 that support it, in order to help track memory corruption issues.
928 Release versions, on the other hand, are built without -lmcheck
929 by default. The --enable-libmcheck/--disable-libmcheck configure
930 options allow the user to override that default.
931 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
932 This configure option allows the user to build GDB with
933 libbabeltrace using which GDB can read Common Trace Format data.
935 * New commands (for set/show, see "New options" below)
938 Catch signals. This is similar to "handle", but allows commands and
939 conditions to be attached.
942 List the BFDs known to GDB.
944 python-interactive [command]
946 Start a Python interactive prompt, or evaluate the optional command
947 and print the result of expressions.
950 "py" is a new alias for "python".
952 enable type-printer [name]...
953 disable type-printer [name]...
954 Enable or disable type printers.
958 ** For the Renesas Super-H architecture, the "regs" command has been removed
959 (has been deprecated in GDB 7.5), and "info all-registers" should be used
964 set print type methods (on|off)
965 show print type methods
966 Control whether method declarations are displayed by "ptype".
967 The default is to show them.
969 set print type typedefs (on|off)
970 show print type typedefs
971 Control whether typedef definitions are displayed by "ptype".
972 The default is to show them.
974 set filename-display basename|relative|absolute
975 show filename-display
976 Control the way in which filenames is displayed.
977 The default is "relative", which preserves previous behavior.
979 set trace-buffer-size
980 show trace-buffer-size
981 Request target to change the size of trace buffer.
983 set remote trace-buffer-size-packet auto|on|off
984 show remote trace-buffer-size-packet
985 Control the use of the remote protocol `QTBuffer:size' packet.
989 Control display of debugging messages related to ARM AArch64.
992 set debug coff-pe-read
993 show debug coff-pe-read
994 Control display of debugging messages related to reading of COFF/PE
999 Control display of debugging messages related to Mach-O symbols
1002 set debug notification
1003 show debug notification
1004 Control display of debugging info for async remote notification.
1008 ** Command parameter changes are now notified using new async record
1009 "=cmd-param-changed".
1010 ** Trace frame changes caused by command "tfind" are now notified using
1011 new async record "=traceframe-changed".
1012 ** The creation, deletion and modification of trace state variables
1013 are now notified using new async records "=tsv-created",
1014 "=tsv-deleted" and "=tsv-modified".
1015 ** The start and stop of process record are now notified using new
1016 async record "=record-started" and "=record-stopped".
1017 ** Memory changes are now notified using new async record
1019 ** The data-disassemble command response will include a "fullname" field
1020 containing the absolute file name when source has been requested.
1021 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1022 command, to allow pattern filling of memory areas.
1023 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1024 library load/unload events.
1025 ** The response to breakpoint commands and breakpoint async records
1026 includes an "installed" field containing a boolean state about each
1027 non-pending tracepoint location is whether installed on target or not.
1028 ** Output of the "-trace-status" command includes a "trace-file" field
1029 containing the name of the trace file being examined. This field is
1030 optional, and only present when examining a trace file.
1031 ** The "fullname" field is now always present along with the "file" field,
1032 even if the file cannot be found by GDB.
1034 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1035 You must have the LZMA library available when configuring GDB for this
1036 feature to be enabled. For more information, see:
1037 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1039 * New remote packets
1042 Set the size of trace buffer. The remote stub reports support for this
1043 packet to gdb's qSupported query.
1046 Enable Branch Trace Store (BTS)-based branch tracing for the current
1047 thread. The remote stub reports support for this packet to gdb's
1051 Disable branch tracing for the current thread. The remote stub reports
1052 support for this packet to gdb's qSupported query.
1055 Read the traced branches for the current thread. The remote stub
1056 reports support for this packet to gdb's qSupported query.
1058 *** Changes in GDB 7.5
1060 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1061 for more x32 ABI info.
1063 * GDB now supports access to MIPS DSP registers on Linux targets.
1065 * GDB now supports debugging microMIPS binaries.
1067 * The "info os" command on GNU/Linux can now display information on
1068 several new classes of objects managed by the operating system:
1069 "info os procgroups" lists process groups
1070 "info os files" lists file descriptors
1071 "info os sockets" lists internet-domain sockets
1072 "info os shm" lists shared-memory regions
1073 "info os semaphores" lists semaphores
1074 "info os msg" lists message queues
1075 "info os modules" lists loaded kernel modules
1077 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1078 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1079 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1080 options and inspect the probe arguments using the new $_probe_arg family
1081 of convenience variables. You can obtain more information about SystemTap
1082 in <http://sourceware.org/systemtap/>.
1084 * GDB now supports reversible debugging on ARM, it allows you to
1085 debug basic ARM and THUMB instructions, and provides
1086 record/replay support.
1088 * The option "symbol-reloading" has been deleted as it is no longer used.
1092 ** GDB commands implemented in Python can now be put in command class
1095 ** The "maint set python print-stack on|off" is now deleted.
1097 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1098 apply "flag enum"-style pretty-printing to any enum.
1100 ** gdb.lookup_symbol can now work when there is no current frame.
1102 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1103 the source at which the symbol was defined.
1105 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1106 method 'value'. The former indicates whether the symbol needs a
1107 frame in order to compute its value, and the latter computes the
1110 ** A new method 'referenced_value' on gdb.Value objects which can
1111 dereference pointer as well as C++ reference values.
1113 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1114 which return the global and static blocks (as gdb.Block objects),
1115 of the underlying symbol table, respectively.
1117 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1118 object associated with a PC value.
1120 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1121 of the address range occupied by code for the current source line.
1123 * Go language support.
1124 GDB now supports debugging programs written in the Go programming
1127 * GDBserver now supports stdio connections.
1128 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1130 * The binary "gdbtui" can no longer be built or installed.
1131 Use "gdb -tui" instead.
1133 * GDB will now print "flag" enums specially. A flag enum is one where
1134 all the enumerator values have no bits in common when pairwise
1135 "and"ed. When printing a value whose type is a flag enum, GDB will
1136 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1137 (gdb) print (enum E) 3
1140 * The filename part of a linespec will now match trailing components
1141 of a source file name. For example, "break gcc/expr.c:1000" will
1142 now set a breakpoint in build/gcc/expr.c, but not
1143 build/libcpp/expr.c.
1145 * The "info proc" and "generate-core-file" commands will now also
1146 work on remote targets connected to GDBserver on Linux.
1148 * The command "info catch" has been removed. It has been disabled
1149 since December 2007.
1151 * The "catch exception" and "catch assert" commands now accept
1152 a condition at the end of the command, much like the "break"
1153 command does. For instance:
1155 (gdb) catch exception Constraint_Error if Barrier = True
1157 Previously, it was possible to add a condition to such catchpoints,
1158 but it had to be done as a second step, after the catchpoint had been
1159 created, using the "condition" command.
1161 * The "info static-tracepoint-marker" command will now also work on
1162 native Linux targets with in-process agent.
1164 * GDB can now set breakpoints on inlined functions.
1166 * The .gdb_index section has been updated to include symbols for
1167 inlined functions. GDB will ignore older .gdb_index sections by
1168 default, which could cause symbol files to be loaded more slowly
1169 until their .gdb_index sections can be recreated. The new command
1170 "set use-deprecated-index-sections on" will cause GDB to use any older
1171 .gdb_index sections it finds. This will restore performance, but the
1172 ability to set breakpoints on inlined functions will be lost in symbol
1173 files with older .gdb_index sections.
1175 The .gdb_index section has also been updated to record more information
1176 about each symbol. This speeds up the "info variables", "info functions"
1177 and "info types" commands when used with programs having the .gdb_index
1178 section, as well as speeding up debugging with shared libraries using
1179 the .gdb_index section.
1181 * Ada support for GDB/MI Variable Objects has been added.
1183 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1188 ** New command -info-os is the MI equivalent of "info os".
1190 ** Output logs ("set logging" and related) now include MI output.
1194 ** "set use-deprecated-index-sections on|off"
1195 "show use-deprecated-index-sections on|off"
1196 Controls the use of deprecated .gdb_index sections.
1198 ** "catch load" and "catch unload" can be used to stop when a shared
1199 library is loaded or unloaded, respectively.
1201 ** "enable count" can be used to auto-disable a breakpoint after
1204 ** "info vtbl" can be used to show the virtual method tables for
1205 C++ and Java objects.
1207 ** "explore" and its sub commands "explore value" and "explore type"
1208 can be used to recursively explore values and types of
1209 expressions. These commands are available only if GDB is
1210 configured with '--with-python'.
1212 ** "info auto-load" shows status of all kinds of auto-loaded files,
1213 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1214 sequences of commands files, "info auto-load python-scripts"
1215 shows status of auto-loading Python script files,
1216 "info auto-load local-gdbinit" shows status of loading init file
1217 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1218 status of inferior specific thread debugging shared library loading.
1220 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1221 and "show auto-load-scripts" commands have been deprecated, use their
1222 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1223 and "show auto-load python-scripts" counterparts instead.
1225 ** "dprintf location,format,args..." creates a dynamic printf, which
1226 is basically a breakpoint that does a printf and immediately
1227 resumes your program's execution, so it is like a printf that you
1228 can insert dynamically at runtime instead of at compiletime.
1230 ** "set print symbol"
1232 Controls whether GDB attempts to display the symbol, if any,
1233 corresponding to addresses it prints. This defaults to "on", but
1234 you can set it to "off" to restore GDB's previous behavior.
1236 * Deprecated commands
1238 ** For the Renesas Super-H architecture, the "regs" command has been
1239 deprecated, and "info all-registers" should be used instead.
1243 Renesas RL78 rl78-*-elf
1244 HP OpenVMS ia64 ia64-hp-openvms*
1246 * GDBserver supports evaluation of breakpoint conditions. When
1247 support is advertised by GDBserver, GDB may be told to send the
1248 breakpoint conditions in bytecode form to GDBserver. GDBserver
1249 will only report the breakpoint trigger to GDB when its condition
1254 set mips compression
1255 show mips compression
1256 Select the compressed ISA encoding used in functions that have no symbol
1257 information available. The encoding can be set to either of:
1260 and is updated automatically from ELF file flags if available.
1262 set breakpoint condition-evaluation
1263 show breakpoint condition-evaluation
1264 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1265 GDBserver ("target"). Default option "auto" chooses the most efficient
1267 This option can improve debugger efficiency depending on the speed of the
1271 Disable auto-loading globally.
1274 Show auto-loading setting of all kinds of auto-loaded files.
1276 set auto-load gdb-scripts on|off
1277 show auto-load gdb-scripts
1278 Control auto-loading of GDB canned sequences of commands files.
1280 set auto-load python-scripts on|off
1281 show auto-load python-scripts
1282 Control auto-loading of Python script files.
1284 set auto-load local-gdbinit on|off
1285 show auto-load local-gdbinit
1286 Control loading of init file (.gdbinit) from current directory.
1288 set auto-load libthread-db on|off
1289 show auto-load libthread-db
1290 Control auto-loading of inferior specific thread debugging shared library.
1292 set auto-load scripts-directory <dir1>[:<dir2>...]
1293 show auto-load scripts-directory
1294 Set a list of directories from which to load auto-loaded scripts.
1295 Automatically loaded Python scripts and GDB scripts are located in one
1296 of the directories listed by this option.
1297 The delimiter (':' above) may differ according to the host platform.
1299 set auto-load safe-path <dir1>[:<dir2>...]
1300 show auto-load safe-path
1301 Set a list of directories from which it is safe to auto-load files.
1302 The delimiter (':' above) may differ according to the host platform.
1304 set debug auto-load on|off
1305 show debug auto-load
1306 Control display of debugging info for auto-loading the files above.
1308 set dprintf-style gdb|call|agent
1310 Control the way in which a dynamic printf is performed; "gdb"
1311 requests a GDB printf command, while "call" causes dprintf to call a
1312 function in the inferior. "agent" requests that the target agent
1313 (such as GDBserver) do the printing.
1315 set dprintf-function <expr>
1316 show dprintf-function
1317 set dprintf-channel <expr>
1318 show dprintf-channel
1319 Set the function and optional first argument to the call when using
1320 the "call" style of dynamic printf.
1322 set disconnected-dprintf on|off
1323 show disconnected-dprintf
1324 Control whether agent-style dynamic printfs continue to be in effect
1325 after GDB disconnects.
1327 * New configure options
1329 --with-auto-load-dir
1330 Configure default value for the 'set auto-load scripts-directory'
1331 setting above. It defaults to '$debugdir:$datadir/auto-load',
1332 $debugdir representing global debugging info directories (available
1333 via 'show debug-file-directory') and $datadir representing GDB's data
1334 directory (available via 'show data-directory').
1336 --with-auto-load-safe-path
1337 Configure default value for the 'set auto-load safe-path' setting
1338 above. It defaults to the --with-auto-load-dir setting.
1340 --without-auto-load-safe-path
1341 Set 'set auto-load safe-path' to '/', effectively disabling this
1344 * New remote packets
1346 z0/z1 conditional breakpoints extension
1348 The z0/z1 breakpoint insertion packets have been extended to carry
1349 a list of conditional expressions over to the remote stub depending on the
1350 condition evaluation mode. The use of this extension can be controlled
1351 via the "set remote conditional-breakpoints-packet" command.
1355 Specify the signals which the remote stub may pass to the debugged
1356 program without GDB involvement.
1358 * New command line options
1360 --init-command=FILE, -ix Like --command, -x but execute it
1361 before loading inferior.
1362 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1363 execute it before loading inferior.
1365 *** Changes in GDB 7.4
1367 * GDB now handles ambiguous linespecs more consistently; the existing
1368 FILE:LINE support has been expanded to other types of linespecs. A
1369 breakpoint will now be set on all matching locations in all
1370 inferiors, and locations will be added or removed according to
1373 * GDB now allows you to skip uninteresting functions and files when
1374 stepping with the "skip function" and "skip file" commands.
1376 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1377 and "show remote hardware-watchpoint-length-limit". These allows to
1378 set or show the maximum length limit (in bytes) of a remote
1379 target hardware watchpoint.
1381 This allows e.g. to use "unlimited" hardware watchpoints with the
1382 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1383 watchpoints are slower than real hardware watchpoints but are
1384 significantly faster than gdb software watchpoints.
1388 ** The register_pretty_printer function in module gdb.printing now takes
1389 an optional `replace' argument. If True, the new printer replaces any
1392 ** The "maint set python print-stack on|off" command has been
1393 deprecated and will be deleted in GDB 7.5.
1394 A new command: "set python print-stack none|full|message" has
1395 replaced it. Additionally, the default for "print-stack" is
1396 now "message", which just prints the error message without
1399 ** A prompt substitution hook (prompt_hook) is now available to the
1402 ** A new Python module, gdb.prompt has been added to the GDB Python
1403 modules library. This module provides functionality for
1404 escape sequences in prompts (used by set/show
1405 extended-prompt). These escape sequences are replaced by their
1406 corresponding value.
1408 ** Python commands and convenience-functions located in
1409 'data-directory'/python/gdb/command and
1410 'data-directory'/python/gdb/function are now automatically loaded
1413 ** Blocks now provide four new attributes. global_block and
1414 static_block will return the global and static blocks
1415 respectively. is_static and is_global are boolean attributes
1416 that indicate if the block is one of those two types.
1418 ** Symbols now provide the "type" attribute, the type of the symbol.
1420 ** The "gdb.breakpoint" function has been deprecated in favor of
1423 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1424 of a function. This class is based on the "finish" command
1425 available in the CLI.
1427 ** Type objects for struct and union types now allow access to
1428 the fields using standard Python dictionary (mapping) methods.
1429 For example, "some_type['myfield']" now works, as does
1430 "some_type.items()".
1432 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1435 ** A new function, "deep_items" has been added to the gdb.types
1436 module in the GDB Python modules library. This function returns
1437 an iterator over the fields of a struct or union type. Unlike
1438 the standard Python "iteritems" method, it will recursively traverse
1439 any anonymous fields.
1443 ** "*stopped" events can report several new "reason"s, such as
1446 ** Breakpoint changes are now notified using new async records, like
1447 "=breakpoint-modified".
1449 ** New command -ada-task-info.
1451 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1452 $sdir specifies the default system locations of shared libraries.
1453 $pdir specifies the directory where the libpthread used by the application
1456 GDB no longer looks in $sdir and $pdir after it has searched the directories
1457 mentioned in libthread-db-search-path. If you want to search those
1458 directories, they must be specified in libthread-db-search-path.
1459 The default value of libthread-db-search-path on GNU/Linux and Solaris
1460 systems is now "$sdir:$pdir".
1462 $pdir is not supported by gdbserver, it is currently ignored.
1463 $sdir is supported by gdbserver.
1465 * New configure option --with-iconv-bin.
1466 When using the internationalization support like the one in the GNU C
1467 library, GDB will invoke the "iconv" program to get a list of supported
1468 character sets. If this program lives in a non-standard location, one can
1469 use this option to specify where to find it.
1471 * When natively debugging programs on PowerPC BookE processors running
1472 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1473 watchpoints, which specify a mask in addition to an address to watch.
1474 The mask specifies that some bits of an address (the bits which are
1475 reset in the mask) should be ignored when matching the address accessed
1476 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1477 section in the user manual for more details.
1479 * The new option --once causes GDBserver to stop listening for connections once
1480 the first connection is made. The listening port used by GDBserver will
1481 become available after that.
1483 * New commands "info macros" and "alias" have been added.
1485 * New function parameters suffix @entry specifies value of function parameter
1486 at the time the function got called. Entry values are available only since
1492 "!" is now an alias of the "shell" command.
1493 Note that no space is needed between "!" and SHELL COMMAND.
1497 watch EXPRESSION mask MASK_VALUE
1498 The watch command now supports the mask argument which allows creation
1499 of masked watchpoints, if the current architecture supports this feature.
1501 info auto-load-scripts [REGEXP]
1502 This command was formerly named "maintenance print section-scripts".
1503 It is now generally useful and is no longer a maintenance-only command.
1505 info macro [-all] [--] MACRO
1506 The info macro command has new options `-all' and `--'. The first for
1507 printing all definitions of a macro. The second for explicitly specifying
1508 the end of arguments and the beginning of the macro name in case the macro
1509 name starts with a hyphen.
1511 collect[/s] EXPRESSIONS
1512 The tracepoint collect command now takes an optional modifier "/s"
1513 that directs it to dereference pointer-to-character types and
1514 collect the bytes of memory up to a zero byte. The behavior is
1515 similar to what you see when you use the regular print command on a
1516 string. An optional integer following the "/s" sets a bound on the
1517 number of bytes that will be collected.
1520 The trace start command now interprets any supplied arguments as a
1521 note to be recorded with the trace run, with an effect similar to
1522 setting the variable trace-notes.
1525 The trace stop command now interprets any arguments as a note to be
1526 mentioned along with the tstatus report that the trace was stopped
1527 with a command. The effect is similar to setting the variable
1530 * Tracepoints can now be enabled and disabled at any time after a trace
1531 experiment has been started using the standard "enable" and "disable"
1532 commands. It is now possible to start a trace experiment with no enabled
1533 tracepoints; GDB will display a warning, but will allow the experiment to
1534 begin, assuming that tracepoints will be enabled as needed while the trace
1537 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1538 locations with 4-byte instructions, when they were previously
1539 limited to locations with instructions of 5 bytes or longer.
1543 set debug dwarf2-read
1544 show debug dwarf2-read
1545 Turns on or off display of debugging messages related to reading
1546 DWARF debug info. The default is off.
1548 set debug symtab-create
1549 show debug symtab-create
1550 Turns on or off display of debugging messages related to symbol table
1551 creation. The default is off.
1554 show extended-prompt
1555 Set the GDB prompt, and allow escape sequences to be inserted to
1556 display miscellaneous information (see 'help set extended-prompt'
1557 for the list of sequences). This prompt (and any information
1558 accessed through the escape sequences) is updated every time the
1559 prompt is displayed.
1561 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1562 show print entry-values
1563 Set printing of frame argument values at function entry. In some cases
1564 GDB can determine the value of function argument which was passed by the
1565 function caller, even if the value was modified inside the called function.
1567 set debug entry-values
1568 show debug entry-values
1569 Control display of debugging info for determining frame argument values at
1570 function entry and virtual tail call frames.
1572 set basenames-may-differ
1573 show basenames-may-differ
1574 Set whether a source file may have multiple base names.
1575 (A "base name" is the name of a file with the directory part removed.
1576 Example: The base name of "/home/user/hello.c" is "hello.c".)
1577 If set, GDB will canonicalize file names (e.g., expand symlinks)
1578 before comparing them. Canonicalization is an expensive operation,
1579 but it allows the same file be known by more than one base name.
1580 If not set (the default), all source files are assumed to have just
1581 one base name, and gdb will do file name comparisons more efficiently.
1587 Set a user name and notes for the current and any future trace runs.
1588 This is useful for long-running and/or disconnected traces, to
1589 inform others (or yourself) as to who is running the trace, supply
1590 contact information, or otherwise explain what is going on.
1592 set trace-stop-notes
1593 show trace-stop-notes
1594 Set a note attached to the trace run, that is displayed when the
1595 trace has been stopped by a tstop command. This is useful for
1596 instance as an explanation, if you are stopping a trace run that was
1597 started by someone else.
1599 * New remote packets
1603 Dynamically enable a tracepoint in a started trace experiment.
1607 Dynamically disable a tracepoint in a started trace experiment.
1611 Set the user and notes of the trace run.
1615 Query the current status of a tracepoint.
1619 Query the minimum length of instruction at which a fast tracepoint may
1622 * Dcache size (number of lines) and line-size are now runtime-configurable
1623 via "set dcache line" and "set dcache line-size" commands.
1627 Texas Instruments TMS320C6x tic6x-*-*
1631 Renesas RL78 rl78-*-elf
1633 *** Changes in GDB 7.3.1
1635 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1637 *** Changes in GDB 7.3
1639 * GDB has a new command: "thread find [REGEXP]".
1640 It finds the thread id whose name, target id, or thread extra info
1641 matches the given regular expression.
1643 * The "catch syscall" command now works on mips*-linux* targets.
1645 * The -data-disassemble MI command now supports modes 2 and 3 for
1646 dumping the instruction opcodes.
1648 * New command line options
1650 -data-directory DIR Specify DIR as the "data-directory".
1651 This is mostly for testing purposes.
1653 * The "maint set python auto-load on|off" command has been renamed to
1654 "set auto-load-scripts on|off".
1656 * GDB has a new command: "set directories".
1657 It is like the "dir" command except that it replaces the
1658 source path list instead of augmenting it.
1660 * GDB now understands thread names.
1662 On GNU/Linux, "info threads" will display the thread name as set by
1663 prctl or pthread_setname_np.
1665 There is also a new command, "thread name", which can be used to
1666 assign a name internally for GDB to display.
1669 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1670 has been integrated into GDB.
1674 ** The function gdb.Write now accepts an optional keyword 'stream'.
1675 This keyword, when provided, will direct the output to either
1676 stdout, stderr, or GDB's logging output.
1678 ** Parameters can now be be sub-classed in Python, and in particular
1679 you may implement the get_set_doc and get_show_doc functions.
1680 This improves how Parameter set/show documentation is processed
1681 and allows for more dynamic content.
1683 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1684 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1685 have an is_valid method.
1687 ** Breakpoints can now be sub-classed in Python, and in particular
1688 you may implement a 'stop' function that is executed each time
1689 the inferior reaches that breakpoint.
1691 ** New function gdb.lookup_global_symbol looks up a global symbol.
1693 ** GDB values in Python are now callable if the value represents a
1694 function. For example, if 'some_value' represents a function that
1695 takes two integer parameters and returns a value, you can call
1696 that function like so:
1698 result = some_value (10,20)
1700 ** Module gdb.types has been added.
1701 It contains a collection of utilities for working with gdb.Types objects:
1702 get_basic_type, has_field, make_enum_dict.
1704 ** Module gdb.printing has been added.
1705 It contains utilities for writing and registering pretty-printers.
1706 New classes: PrettyPrinter, SubPrettyPrinter,
1707 RegexpCollectionPrettyPrinter.
1708 New function: register_pretty_printer.
1710 ** New commands "info pretty-printers", "enable pretty-printer" and
1711 "disable pretty-printer" have been added.
1713 ** gdb.parameter("directories") is now available.
1715 ** New function gdb.newest_frame returns the newest frame in the
1718 ** The gdb.InferiorThread class has a new "name" attribute. This
1719 holds the thread's name.
1721 ** Python Support for Inferior events.
1722 Python scripts can add observers to be notified of events
1723 occurring in the process being debugged.
1724 The following events are currently supported:
1725 - gdb.events.cont Continue event.
1726 - gdb.events.exited Inferior exited event.
1727 - gdb.events.stop Signal received, and Breakpoint hit events.
1731 ** GDB now puts template parameters in scope when debugging in an
1732 instantiation. For example, if you have:
1734 template<int X> int func (void) { return X; }
1736 then if you step into func<5>, "print X" will show "5". This
1737 feature requires proper debuginfo support from the compiler; it
1738 was added to GCC 4.5.
1740 ** The motion commands "next", "finish", "until", and "advance" now
1741 work better when exceptions are thrown. In particular, GDB will
1742 no longer lose control of the inferior; instead, the GDB will
1743 stop the inferior at the point at which the exception is caught.
1744 This functionality requires a change in the exception handling
1745 code that was introduced in GCC 4.5.
1747 * GDB now follows GCC's rules on accessing volatile objects when
1748 reading or writing target state during expression evaluation.
1749 One notable difference to prior behavior is that "print x = 0"
1750 no longer generates a read of x; the value of the assignment is
1751 now always taken directly from the value being assigned.
1753 * GDB now has some support for using labels in the program's source in
1754 linespecs. For instance, you can use "advance label" to continue
1755 execution to a label.
1757 * GDB now has support for reading and writing a new .gdb_index
1758 section. This section holds a fast index of DWARF debugging
1759 information and can be used to greatly speed up GDB startup and
1760 operation. See the documentation for `save gdb-index' for details.
1762 * The "watch" command now accepts an optional "-location" argument.
1763 When used, this causes GDB to watch the memory referred to by the
1764 expression. Such a watchpoint is never deleted due to it going out
1767 * GDB now supports thread debugging of core dumps on GNU/Linux.
1769 GDB now activates thread debugging using the libthread_db library
1770 when debugging GNU/Linux core dumps, similarly to when debugging
1771 live processes. As a result, when debugging a core dump file, GDB
1772 is now able to display pthread_t ids of threads. For example, "info
1773 threads" shows the same output as when debugging the process when it
1774 was live. In earlier releases, you'd see something like this:
1777 * 1 LWP 6780 main () at main.c:10
1779 While now you see this:
1782 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1784 It is also now possible to inspect TLS variables when debugging core
1787 When debugging a core dump generated on a machine other than the one
1788 used to run GDB, you may need to point GDB at the correct
1789 libthread_db library with the "set libthread-db-search-path"
1790 command. See the user manual for more details on this command.
1792 * When natively debugging programs on PowerPC BookE processors running
1793 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1794 which stop execution of the inferior whenever it executes an instruction
1795 at any address within the specified range. See the "PowerPC Embedded"
1796 section in the user manual for more details.
1798 * New features in the GDB remote stub, GDBserver
1800 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1801 and i686 LynxOS (version 5.x).
1803 ** GDBserver is now supported on Blackfin Linux.
1805 * New native configurations
1807 ia64 HP-UX ia64-*-hpux*
1811 Analog Devices, Inc. Blackfin Processor bfin-*
1813 * Ada task switching is now supported on sparc-elf targets when
1814 debugging a program using the Ravenscar Profile. For more information,
1815 see the "Tasking Support when using the Ravenscar Profile" section
1816 in the GDB user manual.
1818 * Guile support was removed.
1820 * New features in the GNU simulator
1822 ** The --map-info flag lists all known core mappings.
1824 ** CFI flashes may be simulated via the "cfi" device.
1826 *** Changes in GDB 7.2
1828 * Shared library support for remote targets by default
1830 When GDB is configured for a generic, non-OS specific target, like
1831 for example, --target=arm-eabi or one of the many *-*-elf targets,
1832 GDB now queries remote stubs for loaded shared libraries using the
1833 `qXfer:libraries:read' packet. Previously, shared library support
1834 was always disabled for such configurations.
1838 ** Argument Dependent Lookup (ADL)
1840 In C++ ADL lookup directs function search to the namespaces of its
1841 arguments even if the namespace has not been imported.
1851 Here the compiler will search for `foo' in the namespace of 'b'
1852 and find A::foo. GDB now supports this. This construct is commonly
1853 used in the Standard Template Library for operators.
1855 ** Improved User Defined Operator Support
1857 In addition to member operators, GDB now supports lookup of operators
1858 defined in a namespace and imported with a `using' directive, operators
1859 defined in the global scope, operators imported implicitly from an
1860 anonymous namespace, and the ADL operators mentioned in the previous
1862 GDB now also supports proper overload resolution for all the previously
1863 mentioned flavors of operators.
1865 ** static const class members
1867 Printing of static const class members that are initialized in the
1868 class definition has been fixed.
1870 * Windows Thread Information Block access.
1872 On Windows targets, GDB now supports displaying the Windows Thread
1873 Information Block (TIB) structure. This structure is visible either
1874 by using the new command `info w32 thread-information-block' or, by
1875 dereferencing the new convenience variable named `$_tlb', a
1876 thread-specific pointer to the TIB. This feature is also supported
1877 when remote debugging using GDBserver.
1879 * Static tracepoints
1881 Static tracepoints are calls in the user program into a tracing
1882 library. One such library is a port of the LTTng kernel tracer to
1883 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1884 When debugging with GDBserver, GDB now supports combining the GDB
1885 tracepoint machinery with such libraries. For example: the user can
1886 use GDB to probe a static tracepoint marker (a call from the user
1887 program into the tracing library) with the new "strace" command (see
1888 "New commands" below). This creates a "static tracepoint" in the
1889 breakpoint list, that can be manipulated with the same feature set
1890 as fast and regular tracepoints. E.g., collect registers, local and
1891 global variables, collect trace state variables, and define
1892 tracepoint conditions. In addition, the user can collect extra
1893 static tracepoint marker specific data, by collecting the new
1894 $_sdata internal variable. When analyzing the trace buffer, you can
1895 inspect $_sdata like any other variable available to GDB. For more
1896 information, see the "Tracepoints" chapter in GDB user manual. New
1897 remote packets have been defined to support static tracepoints, see
1898 the "New remote packets" section below.
1900 * Better reconstruction of tracepoints after disconnected tracing
1902 GDB will attempt to download the original source form of tracepoint
1903 definitions when starting a trace run, and then will upload these
1904 upon reconnection to the target, resulting in a more accurate
1905 reconstruction of the tracepoints that are in use on the target.
1909 You can now exercise direct control over the ways that GDB can
1910 affect your program. For instance, you can disallow the setting of
1911 breakpoints, so that the program can run continuously (assuming
1912 non-stop mode). In addition, the "observer" variable is available
1913 to switch all of the different controls; in observer mode, GDB
1914 cannot affect the target's behavior at all, which is useful for
1915 tasks like diagnosing live systems in the field.
1917 * The new convenience variable $_thread holds the number of the
1920 * New remote packets
1924 Return the address of the Windows Thread Information Block of a given thread.
1928 In response to several of the tracepoint packets, the target may now
1929 also respond with a number of intermediate `qRelocInsn' request
1930 packets before the final result packet, to have GDB handle
1931 relocating an instruction to execute at a different address. This
1932 is particularly useful for stubs that support fast tracepoints. GDB
1933 reports support for this feature in the qSupported packet.
1937 List static tracepoint markers in the target program.
1941 List static tracepoint markers at a given address in the target
1944 qXfer:statictrace:read
1946 Read the static trace data collected (by a `collect $_sdata'
1947 tracepoint action). The remote stub reports support for this packet
1948 to gdb's qSupported query.
1952 Send the current settings of GDB's permission flags.
1956 Send part of the source (textual) form of a tracepoint definition,
1957 which includes location, conditional, and action list.
1959 * The source command now accepts a -s option to force searching for the
1960 script in the source search path even if the script name specifies
1963 * New features in the GDB remote stub, GDBserver
1965 - GDBserver now support tracepoints (including fast tracepoints, and
1966 static tracepoints). The feature is currently supported by the
1967 i386-linux and amd64-linux builds. See the "Tracepoints support
1968 in gdbserver" section in the manual for more information.
1970 GDBserver JIT compiles the tracepoint's conditional agent
1971 expression bytecode into native code whenever possible for low
1972 overhead dynamic tracepoints conditionals. For such tracepoints,
1973 an expression that examines program state is evaluated when the
1974 tracepoint is reached, in order to determine whether to capture
1975 trace data. If the condition is simple and false, processing the
1976 tracepoint finishes very quickly and no data is gathered.
1978 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1979 for static tracepoints support.
1981 - GDBserver now supports x86_64 Windows 64-bit debugging.
1983 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1984 it understands register description.
1986 * The --batch flag now disables pagination and queries.
1988 * X86 general purpose registers
1990 GDB now supports reading/writing byte, word and double-word x86
1991 general purpose registers directly. This means you can use, say,
1992 $ah or $ax to refer, respectively, to the byte register AH and
1993 16-bit word register AX that are actually portions of the 32-bit
1994 register EAX or 64-bit register RAX.
1996 * The `commands' command now accepts a range of breakpoints to modify.
1997 A plain `commands' following a command that creates multiple
1998 breakpoints affects all the breakpoints set by that command. This
1999 applies to breakpoints set by `rbreak', and also applies when a
2000 single `break' command creates multiple breakpoints (e.g.,
2001 breakpoints on overloaded c++ functions).
2003 * The `rbreak' command now accepts a filename specification as part of
2004 its argument, limiting the functions selected by the regex to those
2005 in the specified file.
2007 * Support for remote debugging Windows and SymbianOS shared libraries
2008 from Unix hosts has been improved. Non Windows GDB builds now can
2009 understand target reported file names that follow MS-DOS based file
2010 system semantics, such as file names that include drive letters and
2011 use the backslash character as directory separator. This makes it
2012 possible to transparently use the "set sysroot" and "set
2013 solib-search-path" on Unix hosts to point as host copies of the
2014 target's shared libraries. See the new command "set
2015 target-file-system-kind" described below, and the "Commands to
2016 specify files" section in the user manual for more information.
2020 eval template, expressions...
2021 Convert the values of one or more expressions under the control
2022 of the string template to a command line, and call it.
2024 set target-file-system-kind unix|dos-based|auto
2025 show target-file-system-kind
2026 Set or show the assumed file system kind for target reported file
2029 save breakpoints <filename>
2030 Save all current breakpoint definitions to a file suitable for use
2031 in a later debugging session. To read the saved breakpoint
2032 definitions, use the `source' command.
2034 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2037 info static-tracepoint-markers
2038 Display information about static tracepoint markers in the target.
2040 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2041 Define a static tracepoint by probing a marker at the given
2042 function, line, address, or marker ID.
2046 Enable and disable observer mode.
2048 set may-write-registers on|off
2049 set may-write-memory on|off
2050 set may-insert-breakpoints on|off
2051 set may-insert-tracepoints on|off
2052 set may-insert-fast-tracepoints on|off
2053 set may-interrupt on|off
2054 Set individual permissions for GDB effects on the target. Note that
2055 some of these settings can have undesirable or surprising
2056 consequences, particularly when changed in the middle of a session.
2057 For instance, disabling the writing of memory can prevent
2058 breakpoints from being inserted, cause single-stepping to fail, or
2059 even crash your program, if you disable after breakpoints have been
2060 inserted. However, GDB should not crash.
2062 set record memory-query on|off
2063 show record memory-query
2064 Control whether to stop the inferior if memory changes caused
2065 by an instruction cannot be recorded.
2070 The disassemble command now supports "start,+length" form of two arguments.
2074 ** GDB now provides a new directory location, called the python directory,
2075 where Python scripts written for GDB can be installed. The location
2076 of that directory is <data-directory>/python, where <data-directory>
2077 is the GDB data directory. For more details, see section `Scripting
2078 GDB using Python' in the manual.
2080 ** The GDB Python API now has access to breakpoints, symbols, symbol
2081 tables, program spaces, inferiors, threads and frame's code blocks.
2082 Additionally, GDB Parameters can now be created from the API, and
2083 manipulated via set/show in the CLI.
2085 ** New functions gdb.target_charset, gdb.target_wide_charset,
2086 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2088 ** New exception gdb.GdbError.
2090 ** Pretty-printers are now also looked up in the current program space.
2092 ** Pretty-printers can now be individually enabled and disabled.
2094 ** GDB now looks for names of Python scripts to auto-load in a
2095 special section named `.debug_gdb_scripts', in addition to looking
2096 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2098 * Tracepoint actions were unified with breakpoint commands. In particular,
2099 there are no longer differences in "info break" output for breakpoints and
2100 tracepoints and the "commands" command can be used for both tracepoints and
2101 regular breakpoints.
2105 ARM Symbian arm*-*-symbianelf*
2107 * D language support.
2108 GDB now supports debugging programs written in the D programming
2111 * GDB now supports the extended ptrace interface for PowerPC which is
2112 available since Linux kernel version 2.6.34. This automatically enables
2113 any hardware breakpoints and additional hardware watchpoints available in
2114 the processor. The old ptrace interface exposes just one hardware
2115 watchpoint and no hardware breakpoints.
2117 * GDB is now able to use the Data Value Compare (DVC) register available on
2118 embedded PowerPC processors to implement in hardware simple watchpoint
2119 conditions of the form:
2121 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2123 This works in native GDB running on Linux kernels with the extended ptrace
2124 interface mentioned above.
2126 *** Changes in GDB 7.1
2130 ** Namespace Support
2132 GDB now supports importing of namespaces in C++. This enables the
2133 user to inspect variables from imported namespaces. Support for
2134 namepace aliasing has also been added. So, if a namespace is
2135 aliased in the current scope (e.g. namepace C=A; ) the user can
2136 print variables using the alias (e.g. (gdb) print C::x).
2140 All known bugs relating to the printing of virtual base class were
2141 fixed. It is now possible to call overloaded static methods using a
2146 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2147 and reinterpret_cast<> are now handled by the C++ expression parser.
2151 Xilinx MicroBlaze microblaze-*-*
2156 Xilinx MicroBlaze microblaze
2159 * Multi-program debugging.
2161 GDB now has support for multi-program (a.k.a. multi-executable or
2162 multi-exec) debugging. This allows for debugging multiple inferiors
2163 simultaneously each running a different program under the same GDB
2164 session. See "Debugging Multiple Inferiors and Programs" in the
2165 manual for more information. This implied some user visible changes
2166 in the multi-inferior support. For example, "info inferiors" now
2167 lists inferiors that are not running yet or that have exited
2168 already. See also "New commands" and "New options" below.
2170 * New tracing features
2172 GDB's tracepoint facility now includes several new features:
2174 ** Trace state variables
2176 GDB tracepoints now include support for trace state variables, which
2177 are variables managed by the target agent during a tracing
2178 experiment. They are useful for tracepoints that trigger each
2179 other, so for instance one tracepoint can count hits in a variable,
2180 and then a second tracepoint has a condition that is true when the
2181 count reaches a particular value. Trace state variables share the
2182 $-syntax of GDB convenience variables, and can appear in both
2183 tracepoint actions and condition expressions. Use the "tvariable"
2184 command to create, and "info tvariables" to view; see "Trace State
2185 Variables" in the manual for more detail.
2189 GDB now includes an option for defining fast tracepoints, which
2190 targets may implement more efficiently, such as by installing a jump
2191 into the target agent rather than a trap instruction. The resulting
2192 speedup can be by two orders of magnitude or more, although the
2193 tradeoff is that some program locations on some target architectures
2194 might not allow fast tracepoint installation, for instance if the
2195 instruction to be replaced is shorter than the jump. To request a
2196 fast tracepoint, use the "ftrace" command, with syntax identical to
2197 the regular trace command.
2199 ** Disconnected tracing
2201 It is now possible to detach GDB from the target while it is running
2202 a trace experiment, then reconnect later to see how the experiment
2203 is going. In addition, a new variable disconnected-tracing lets you
2204 tell the target agent whether to continue running a trace if the
2205 connection is lost unexpectedly.
2209 GDB now has the ability to save the trace buffer into a file, and
2210 then use that file as a target, similarly to you can do with
2211 corefiles. You can select trace frames, print data that was
2212 collected in them, and use tstatus to display the state of the
2213 tracing run at the moment that it was saved. To create a trace
2214 file, use "tsave <filename>", and to use it, do "target tfile
2217 ** Circular trace buffer
2219 You can ask the target agent to handle the trace buffer as a
2220 circular buffer, discarding the oldest trace frames to make room for
2221 newer ones, by setting circular-trace-buffer to on. This feature may
2222 not be available for all target agents.
2227 The disassemble command, when invoked with two arguments, now requires
2228 the arguments to be comma-separated.
2231 The info variables command now displays variable definitions. Files
2232 which only declare a variable are not shown.
2235 The source command is now capable of sourcing Python scripts.
2236 This feature is dependent on the debugger being build with Python
2239 Related to this enhancement is also the introduction of a new command
2240 "set script-extension" (see below).
2242 * New commands (for set/show, see "New options" below)
2244 record save [<FILENAME>]
2245 Save a file (in core file format) containing the process record
2246 execution log for replay debugging at a later time.
2248 record restore <FILENAME>
2249 Restore the process record execution log that was saved at an
2250 earlier time, for replay debugging.
2252 add-inferior [-copies <N>] [-exec <FILENAME>]
2255 clone-inferior [-copies <N>] [ID]
2256 Make a new inferior ready to execute the same program another
2257 inferior has loaded.
2262 maint info program-spaces
2263 List the program spaces loaded into GDB.
2265 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2266 show remote interrupt-sequence
2267 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2268 as the sequence to the remote target in order to interrupt the execution.
2269 Ctrl-C is a default. Some system prefers BREAK which is high level of
2270 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2271 Magic SysRq g. It is BREAK signal and character 'g'.
2273 set remote interrupt-on-connect [on | off]
2274 show remote interrupt-on-connect
2275 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2276 remote target when gdb connects to it. This is needed when you debug
2279 set remotebreak [on | off]
2281 Deprecated. Use "set/show remote interrupt-sequence" instead.
2283 tvariable $NAME [ = EXP ]
2284 Create or modify a trace state variable.
2287 List trace state variables and their values.
2289 delete tvariable $NAME ...
2290 Delete one or more trace state variables.
2293 Evaluate the given expressions without collecting anything into the
2294 trace buffer. (Valid in tracepoint actions only.)
2296 ftrace FN / FILE:LINE / *ADDR
2297 Define a fast tracepoint at the given function, line, or address.
2299 * New expression syntax
2301 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2302 GDB now parses 0b101010 identically with 42.
2306 set follow-exec-mode new|same
2307 show follow-exec-mode
2308 Control whether GDB reuses the same inferior across an exec call or
2309 creates a new one. This is useful to be able to restart the old
2310 executable after the inferior having done an exec call.
2312 set default-collect EXPR, ...
2313 show default-collect
2314 Define a list of expressions to be collected at each tracepoint.
2315 This is a useful way to ensure essential items are not overlooked,
2316 such as registers or a critical global variable.
2318 set disconnected-tracing
2319 show disconnected-tracing
2320 If set to 1, the target is instructed to continue tracing if it
2321 loses its connection to GDB. If 0, the target is to stop tracing
2324 set circular-trace-buffer
2325 show circular-trace-buffer
2326 If set to on, the target is instructed to use a circular trace buffer
2327 and discard the oldest trace frames instead of stopping the trace due
2328 to a full trace buffer. If set to off, the trace stops when the buffer
2329 fills up. Some targets may not support this.
2331 set script-extension off|soft|strict
2332 show script-extension
2333 If set to "off", the debugger does not perform any script language
2334 recognition, and all sourced files are assumed to be GDB scripts.
2335 If set to "soft" (the default), files are sourced according to
2336 filename extension, falling back to GDB scripts if the first
2338 If set to "strict", files are sourced according to filename extension.
2340 set ada trust-PAD-over-XVS on|off
2341 show ada trust-PAD-over-XVS
2342 If off, activate a workaround against a bug in the debugging information
2343 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2344 the GCC sources for more information about the GNAT encoding and
2345 PAD types in particular). It is always safe to set this option to
2346 off, but this introduces a slight performance penalty. The default
2349 * Python API Improvements
2351 ** GDB provides the new class gdb.LazyString. This is useful in
2352 some pretty-printing cases. The new method gdb.Value.lazy_string
2353 provides a simple way to create objects of this type.
2355 ** The fields returned by gdb.Type.fields now have an
2356 `is_base_class' attribute.
2358 ** The new method gdb.Type.range returns the range of an array type.
2360 ** The new method gdb.parse_and_eval can be used to parse and
2361 evaluate an expression.
2363 * New remote packets
2366 Define a trace state variable.
2369 Get the current value of a trace state variable.
2372 Set desired tracing behavior upon disconnection.
2375 Set the trace buffer to be linear or circular.
2378 Get data about the tracepoints currently in use.
2382 Process record now works correctly with hardware watchpoints.
2384 Multiple bug fixes have been made to the mips-irix port, making it
2385 much more reliable. In particular:
2386 - Debugging threaded applications is now possible again. Previously,
2387 GDB would hang while starting the program, or while waiting for
2388 the program to stop at a breakpoint.
2389 - Attaching to a running process no longer hangs.
2390 - An error occurring while loading a core file has been fixed.
2391 - Changing the value of the PC register now works again. This fixes
2392 problems observed when using the "jump" command, or when calling
2393 a function from GDB, or even when assigning a new value to $pc.
2394 - With the "finish" and "return" commands, the return value for functions
2395 returning a small array is now correctly printed.
2396 - It is now possible to break on shared library code which gets executed
2397 during a shared library init phase (code executed while executing
2398 their .init section). Previously, the breakpoint would have no effect.
2399 - GDB is now able to backtrace through the signal handler for
2400 non-threaded programs.
2402 PIE (Position Independent Executable) programs debugging is now supported.
2403 This includes debugging execution of PIC (Position Independent Code) shared
2404 libraries although for that, it should be possible to run such libraries as an
2407 *** Changes in GDB 7.0
2409 * GDB now has an interface for JIT compilation. Applications that
2410 dynamically generate code can create symbol files in memory and register
2411 them with GDB. For users, the feature should work transparently, and
2412 for JIT developers, the interface is documented in the GDB manual in the
2413 "JIT Compilation Interface" chapter.
2415 * Tracepoints may now be conditional. The syntax is as for
2416 breakpoints; either an "if" clause appended to the "trace" command,
2417 or the "condition" command is available. GDB sends the condition to
2418 the target for evaluation using the same bytecode format as is used
2419 for tracepoint actions.
2421 * The disassemble command now supports: an optional /r modifier, print the
2422 raw instructions in hex as well as in symbolic form, and an optional /m
2423 modifier to print mixed source+assembly.
2425 * Process record and replay
2427 In a architecture environment that supports ``process record and
2428 replay'', ``process record and replay'' target can record a log of
2429 the process execution, and replay it with both forward and reverse
2432 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2433 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2434 set execution-direction {forward|reverse}, for targets that support
2437 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2438 feature is available with a native GDB running on kernel version
2441 * GDB now has support for multi-byte and wide character sets on the
2442 target. Strings whose character type is wchar_t, char16_t, or
2443 char32_t are now correctly printed. GDB supports wide- and unicode-
2444 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2445 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2446 `printf'. This feature requires iconv to work properly; if your
2447 system does not have a working iconv, GDB can use GNU libiconv. See
2448 the installation instructions for more information.
2450 * GDB now supports automatic retrieval of shared library files from
2451 remote targets. To use this feature, specify a system root that begins
2452 with the `remote:' prefix, either via the `set sysroot' command or via
2453 the `--with-sysroot' configure-time option.
2455 * "info sharedlibrary" now takes an optional regex of libraries to show,
2456 and it now reports if a shared library has no debugging information.
2458 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2459 now complete on file names.
2461 * When completing in expressions, gdb will attempt to limit
2462 completions to allowable structure or union fields, where appropriate.
2463 For instance, consider:
2465 # struct example { int f1; double f2; };
2466 # struct example variable;
2469 If the user types TAB at the end of this command line, the available
2470 completions will be "f1" and "f2".
2472 * Inlined functions are now supported. They show up in backtraces, and
2473 the "step", "next", and "finish" commands handle them automatically.
2475 * GDB now supports the token-splicing (##) and stringification (#)
2476 operators when expanding macros. It also supports variable-arity
2479 * GDB now supports inspecting extra signal information, exported by
2480 the new $_siginfo convenience variable. The feature is currently
2481 implemented on linux ARM, i386 and amd64.
2483 * GDB can now display the VFP floating point registers and NEON vector
2484 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2485 can provide these registers (requires Linux 2.6.30 or later). Remote
2486 and simulator targets may also provide them.
2488 * New remote packets
2491 Search memory for a sequence of bytes.
2494 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2495 operation over reliable transport links. Use of this packet is
2496 controlled by the `set remote noack-packet' command.
2499 Kill the process with the specified process ID. Use this in preference
2500 to `k' when multiprocess protocol extensions are supported.
2503 Obtains additional operating system information
2507 Read or write additional signal information.
2509 * Removed remote protocol undocumented extension
2511 An undocumented extension to the remote protocol's `S' stop reply
2512 packet that permited the stub to pass a process id was removed.
2513 Remote servers should use the `T' stop reply packet instead.
2515 * GDB now supports multiple function calling conventions according to the
2516 DWARF-2 DW_AT_calling_convention function attribute.
2518 * The SH target utilizes the aforementioned change to distinguish between gcc
2519 and Renesas calling convention. It also adds the new CLI commands
2520 `set/show sh calling-convention'.
2522 * GDB can now read compressed debug sections, as produced by GNU gold
2523 with the --compress-debug-sections=zlib flag.
2525 * 64-bit core files are now supported on AIX.
2527 * Thread switching is now supported on Tru64.
2529 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2530 which will be allocated using malloc later in program execution.
2532 * The qXfer:libraries:read remote procotol packet now allows passing a
2533 list of section offsets.
2535 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2536 conditions handling signals delivered during attach or thread creation
2537 have also been fixed.
2539 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2540 From the user's standpoint, all unqualified instances of True and False
2541 are treated as the standard definitions, regardless of context.
2543 * GDB now parses C++ symbol and type names more flexibly. For
2546 template<typename T> class C { };
2549 GDB will now correctly handle all of:
2551 ptype C<char const *>
2552 ptype C<char const*>
2553 ptype C<const char *>
2554 ptype C<const char*>
2556 * New features in the GDB remote stub, gdbserver
2558 - The "--wrapper" command-line argument tells gdbserver to use a
2559 wrapper program to launch programs for debugging.
2561 - On PowerPC and S/390 targets, it is now possible to use a single
2562 gdbserver executable to debug both 32-bit and 64-bit programs.
2563 (This requires gdbserver itself to be built as a 64-bit executable.)
2565 - gdbserver uses the new noack protocol mode for TCP connections to
2566 reduce communications latency, if also supported and enabled in GDB.
2568 - Support for the sparc64-linux-gnu target is now included in
2571 - The amd64-linux build of gdbserver now supports debugging both
2572 32-bit and 64-bit programs.
2574 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2575 now support hardware watchpoints, and will use them automatically
2580 GDB now has support for scripting using Python. Whether this is
2581 available is determined at configure time.
2583 New GDB commands can now be written in Python.
2585 * Ada tasking support
2587 Ada tasks can now be inspected in GDB. The following commands have
2591 Print the list of Ada tasks.
2593 Print detailed information about task number N.
2595 Print the task number of the current task.
2597 Switch the context of debugging to task number N.
2599 * Support for user-defined prefixed commands. The "define" command can
2600 add new commands to existing prefixes, e.g. "target".
2602 * Multi-inferior, multi-process debugging.
2604 GDB now has generalized support for multi-inferior debugging. See
2605 "Debugging Multiple Inferiors" in the manual for more information.
2606 Although availability still depends on target support, the command
2607 set is more uniform now. The GNU/Linux specific multi-forks support
2608 has been migrated to this new framework. This implied some user
2609 visible changes; see "New commands" and also "Removed commands"
2612 * Target descriptions can now describe the target OS ABI. See the
2613 "Target Description Format" section in the user manual for more
2616 * Target descriptions can now describe "compatible" architectures
2617 to indicate that the target can execute applications for a different
2618 architecture in addition to those for the main target architecture.
2619 See the "Target Description Format" section in the user manual for
2622 * Multi-architecture debugging.
2624 GDB now includes general supports for debugging applications on
2625 hybrid systems that use more than one single processor architecture
2626 at the same time. Each such hybrid architecture still requires
2627 specific support to be added. The only hybrid architecture supported
2628 in this version of GDB is the Cell Broadband Engine.
2630 * GDB now supports integrated debugging of Cell/B.E. applications that
2631 use both the PPU and SPU architectures. To enable support for hybrid
2632 Cell/B.E. debugging, you need to configure GDB to support both the
2633 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2634 --enable-targets configure option.
2636 * Non-stop mode debugging.
2638 For some targets, GDB now supports an optional mode of operation in
2639 which you can examine stopped threads while other threads continue
2640 to execute freely. This is referred to as non-stop mode, with the
2641 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2642 section in the user manual for more information.
2644 To be able to support remote non-stop debugging, a remote stub needs
2645 to implement the non-stop mode remote protocol extensions, as
2646 described in the "Remote Non-Stop" section of the user manual. The
2647 GDB remote stub, gdbserver, has been adjusted to support these
2648 extensions on linux targets.
2650 * New commands (for set/show, see "New options" below)
2652 catch syscall [NAME(S) | NUMBER(S)]
2653 Catch system calls. Arguments, which should be names of system
2654 calls or their numbers, mean catch only those syscalls. Without
2655 arguments, every syscall will be caught. When the inferior issues
2656 any of the specified syscalls, GDB will stop and announce the system
2657 call, both when it is called and when its call returns. This
2658 feature is currently available with a native GDB running on the
2659 Linux Kernel, under the following architectures: x86, x86_64,
2660 PowerPC and PowerPC64.
2662 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2664 Search memory for a sequence of bytes.
2666 maint set python print-stack
2667 maint show python print-stack
2668 Show a stack trace when an error is encountered in a Python script.
2671 Invoke CODE by passing it to the Python interpreter.
2676 These allow macros to be defined, undefined, and listed
2680 Show operating system information about processes.
2683 List the inferiors currently under GDB's control.
2686 Switch focus to inferior number NUM.
2689 Detach from inferior number NUM.
2692 Kill inferior number NUM.
2696 set spu stop-on-load
2697 show spu stop-on-load
2698 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2700 set spu auto-flush-cache
2701 show spu auto-flush-cache
2702 Control whether to automatically flush the software-managed cache
2703 during Cell/B.E. debugging.
2705 set sh calling-convention
2706 show sh calling-convention
2707 Control the calling convention used when calling SH target functions.
2710 show debug timestamp
2711 Control display of timestamps with GDB debugging output.
2713 set disassemble-next-line
2714 show disassemble-next-line
2715 Control display of disassembled source lines or instructions when
2718 set remote noack-packet
2719 show remote noack-packet
2720 Set/show the use of remote protocol QStartNoAckMode packet. See above
2721 under "New remote packets."
2723 set remote query-attached-packet
2724 show remote query-attached-packet
2725 Control use of remote protocol `qAttached' (query-attached) packet.
2727 set remote read-siginfo-object
2728 show remote read-siginfo-object
2729 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2732 set remote write-siginfo-object
2733 show remote write-siginfo-object
2734 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2737 set remote reverse-continue
2738 show remote reverse-continue
2739 Control use of remote protocol 'bc' (reverse-continue) packet.
2741 set remote reverse-step
2742 show remote reverse-step
2743 Control use of remote protocol 'bs' (reverse-step) packet.
2745 set displaced-stepping
2746 show displaced-stepping
2747 Control displaced stepping mode. Displaced stepping is a way to
2748 single-step over breakpoints without removing them from the debuggee.
2749 Also known as "out-of-line single-stepping".
2752 show debug displaced
2753 Control display of debugging info for displaced stepping.
2755 maint set internal-error
2756 maint show internal-error
2757 Control what GDB does when an internal error is detected.
2759 maint set internal-warning
2760 maint show internal-warning
2761 Control what GDB does when an internal warning is detected.
2766 Use a wrapper program to launch programs for debugging.
2768 set multiple-symbols (all|ask|cancel)
2769 show multiple-symbols
2770 The value of this variable can be changed to adjust the debugger behavior
2771 when an expression or a breakpoint location contains an ambiguous symbol
2772 name (an overloaded function name, for instance).
2774 set breakpoint always-inserted
2775 show breakpoint always-inserted
2776 Keep breakpoints always inserted in the target, as opposed to inserting
2777 them when resuming the target, and removing them when the target stops.
2778 This option can improve debugger performance on slow remote targets.
2780 set arm fallback-mode (arm|thumb|auto)
2781 show arm fallback-mode
2782 set arm force-mode (arm|thumb|auto)
2784 These commands control how ARM GDB determines whether instructions
2785 are ARM or Thumb. The default for both settings is auto, which uses
2786 the current CPSR value for instructions without symbols; previous
2787 versions of GDB behaved as if "set arm fallback-mode arm".
2789 set disable-randomization
2790 show disable-randomization
2791 Standalone programs run with the virtual address space randomization enabled
2792 by default on some platforms. This option keeps the addresses stable across
2793 multiple debugging sessions.
2797 Control whether other threads are stopped or not when some thread hits
2802 Requests that asynchronous execution is enabled in the target, if available.
2803 In this case, it's possible to resume target in the background, and interact
2804 with GDB while the target is running. "show target-async" displays the
2805 current state of asynchronous execution of the target.
2807 set target-wide-charset
2808 show target-wide-charset
2809 The target-wide-charset is the name of the character set that GDB
2810 uses when printing characters whose type is wchar_t.
2812 set tcp auto-retry (on|off)
2814 set tcp connect-timeout
2815 show tcp connect-timeout
2816 These commands allow GDB to retry failed TCP connections to a remote stub
2817 with a specified timeout period; this is useful if the stub is launched
2818 in parallel with GDB but may not be ready to accept connections immediately.
2820 set libthread-db-search-path
2821 show libthread-db-search-path
2822 Control list of directories which GDB will search for appropriate
2825 set schedule-multiple (on|off)
2826 show schedule-multiple
2827 Allow GDB to resume all threads of all processes or only threads of
2828 the current process.
2832 Use more aggressive caching for accesses to the stack. This improves
2833 performance of remote debugging (particularly backtraces) without
2834 affecting correctness.
2836 set interactive-mode (on|off|auto)
2837 show interactive-mode
2838 Control whether GDB runs in interactive mode (on) or not (off).
2839 When in interactive mode, GDB waits for the user to answer all
2840 queries. Otherwise, GDB does not wait and assumes the default
2841 answer. When set to auto (the default), GDB determines which
2842 mode to use based on the stdin settings.
2847 For program forks, this is replaced by the new more generic `info
2848 inferiors' command. To list checkpoints, you can still use the
2849 `info checkpoints' command, which was an alias for the `info forks'
2853 Replaced by the new `inferior' command. To switch between
2854 checkpoints, you can still use the `restart' command, which was an
2855 alias for the `fork' command.
2858 This is removed, since some targets don't have a notion of
2859 processes. To switch between processes, you can still use the
2860 `inferior' command using GDB's own inferior number.
2863 For program forks, this is replaced by the new more generic `kill
2864 inferior' command. To delete a checkpoint, you can still use the
2865 `delete checkpoint' command, which was an alias for the `delete
2869 For program forks, this is replaced by the new more generic `detach
2870 inferior' command. To detach a checkpoint, you can still use the
2871 `detach checkpoint' command, which was an alias for the `detach
2874 * New native configurations
2876 x86/x86_64 Darwin i[34567]86-*-darwin*
2878 x86_64 MinGW x86_64-*-mingw*
2882 Lattice Mico32 lm32-*
2883 x86 DICOS i[34567]86-*-dicos*
2884 x86_64 DICOS x86_64-*-dicos*
2887 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2888 (mingw32ce) debugging.
2894 These commands were actually not implemented on any target.
2896 *** Changes in GDB 6.8
2898 * New native configurations
2900 NetBSD/hppa hppa*-*netbsd*
2901 Xtensa GNU/Linux xtensa*-*-linux*
2905 NetBSD/hppa hppa*-*-netbsd*
2906 Xtensa GNU/Lunux xtensa*-*-linux*
2908 * Change in command line behavior -- corefiles vs. process ids.
2910 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2911 attaching to process NUMBER fails, GDB no longer attempts to open a
2912 core file named NUMBER. Attaching to a program using the -c option
2913 is no longer supported. Instead, use the '-p' or '--pid' options.
2915 * GDB can now be built as a native debugger for debugging Windows x86
2916 (mingw32) Portable Executable (PE) programs.
2918 * Pending breakpoints no longer change their number when their address
2921 * GDB now supports breakpoints with multiple locations,
2922 including breakpoints on C++ constructors, inside C++ templates,
2923 and in inlined functions.
2925 * GDB's ability to debug optimized code has been improved. GDB more
2926 accurately identifies function bodies and lexical blocks that occupy
2927 more than one contiguous range of addresses.
2929 * Target descriptions can now describe registers for PowerPC.
2931 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2932 registers on PowerPC targets.
2934 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2935 targets even when the libthread_db library is not available.
2937 * The GDB remote stub, gdbserver, now supports the new file transfer
2938 commands (remote put, remote get, and remote delete).
2940 * The GDB remote stub, gdbserver, now supports run and attach in
2941 extended-remote mode.
2943 * hppa*64*-*-hpux11* target broken
2944 The debugger is unable to start a program and fails with the following
2945 error: "Error trying to get information about dynamic linker".
2946 The gdb-6.7 release is also affected.
2948 * GDB now supports the --enable-targets= configure option to allow
2949 building a single GDB executable that supports multiple remote
2950 target architectures.
2952 * GDB now supports debugging C and C++ programs which use the
2953 Decimal Floating Point extension. In addition, the PowerPC target
2954 now has a set of pseudo-registers to inspect decimal float values
2955 stored in two consecutive float registers.
2957 * The -break-insert MI command can optionally create pending
2960 * Improved support for debugging Ada
2961 Many improvements to the Ada language support have been made. These
2963 - Better support for Ada2005 interface types
2964 - Improved handling of arrays and slices in general
2965 - Better support for Taft-amendment types
2966 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2968 - Improved command completion in Ada
2971 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2976 set print frame-arguments (all|scalars|none)
2977 show print frame-arguments
2978 The value of this variable can be changed to control which argument
2979 values should be printed by the debugger when displaying a frame.
2984 Transfer files to and from a remote target, and delete remote files.
2991 Transfer files to and from a remote target, and delete remote files.
2993 * New remote packets
3000 Open, close, read, write, and delete files on the remote system.
3003 Attach to an existing process on the remote system, in extended-remote
3007 Run a new process on the remote system, in extended-remote mode.
3009 *** Changes in GDB 6.7
3011 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3012 bfd, libiberty and opcodes, as revealed by static analysis donated by
3013 Coverity, Inc. (http://scan.coverity.com).
3015 * When looking up multiply-defined global symbols, GDB will now prefer the
3016 symbol definition in the current shared library if it was built using the
3017 -Bsymbolic linker option.
3019 * When the Text User Interface (TUI) is not configured, GDB will now
3020 recognize the -tui command-line option and print a message that the TUI
3023 * The GDB remote stub, gdbserver, now has lower overhead for high
3024 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3026 * GDB for MIPS targets now autodetects whether a remote target provides
3027 32-bit or 64-bit register values.
3029 * Support for C++ member pointers has been improved.
3031 * GDB now understands XML target descriptions, which specify the
3032 target's overall architecture. GDB can read a description from
3033 a local file or over the remote serial protocol.
3035 * Vectors of single-byte data use a new integer type which is not
3036 automatically displayed as character or string data.
3038 * The /s format now works with the print command. It displays
3039 arrays of single-byte integers and pointers to single-byte integers
3042 * Target descriptions can now describe target-specific registers,
3043 for architectures which have implemented the support (currently
3044 only ARM, M68K, and MIPS).
3046 * GDB and the GDB remote stub, gdbserver, now support the XScale
3049 * The GDB remote stub, gdbserver, has been updated to support
3050 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3051 has been rewritten to use the standard GDB remote protocol.
3053 * GDB can now step into C++ functions which are called through thunks.
3055 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3057 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3058 layout. It also supports a TextSeg= and DataSeg= response when only
3059 segment base addresses (rather than offsets) are available.
3061 * The /i format now outputs any trailing branch delay slot instructions
3062 immediately following the last instruction within the count specified.
3064 * The GDB remote protocol "T" stop reply packet now supports a
3065 "library" response. Combined with the new "qXfer:libraries:read"
3066 packet, this response allows GDB to debug shared libraries on targets
3067 where the operating system manages the list of loaded libraries (e.g.
3068 Windows and SymbianOS).
3070 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3071 (DLLs) on Windows and Windows CE targets.
3073 * GDB now supports a faster verification that a .debug file matches its binary
3074 according to its build-id signature, if the signature is present.
3080 Enable or disable hardware flow control (RTS/CTS) on the serial port
3081 when debugging using remote targets.
3083 set mem inaccessible-by-default
3084 show mem inaccessible-by-default
3085 If the target supplies a memory map, for instance via the remote
3086 protocol's "qXfer:memory-map:read" packet, setting this variable
3087 prevents GDB from accessing memory outside the memory map. This
3088 is useful for targets with memory mapped registers or which react
3089 badly to accesses of unmapped address space.
3091 set breakpoint auto-hw
3092 show breakpoint auto-hw
3093 If the target supplies a memory map, for instance via the remote
3094 protocol's "qXfer:memory-map:read" packet, setting this variable
3095 lets GDB use hardware breakpoints automatically for memory regions
3096 where it can not use software breakpoints. This covers both the
3097 "break" command and internal breakpoints used for other commands
3098 including "next" and "finish".
3101 catch exception unhandled
3102 Stop the program execution when Ada exceptions are raised.
3105 Stop the program execution when an Ada assertion failed.
3109 Set an alternate system root for target files. This is a more
3110 general version of "set solib-absolute-prefix", which is now
3111 an alias to "set sysroot".
3114 Provide extended SPU facility status information. This set of
3115 commands is available only when debugging the Cell/B.E. SPU
3118 * New native configurations
3120 OpenBSD/sh sh*-*openbsd*
3123 unset tdesc filename
3125 Use the specified local file as an XML target description, and do
3126 not query the target for its built-in description.
3130 OpenBSD/sh sh*-*-openbsd*
3131 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3132 Toshiba Media Processor mep-elf
3134 * New remote packets
3137 Ignore the specified signals; pass them directly to the debugged program
3138 without stopping other threads or reporting them to GDB.
3140 qXfer:features:read:
3141 Read an XML target description from the target, which describes its
3146 Read or write contents of an spufs file on the target system. These
3147 packets are available only on the Cell/B.E. SPU architecture.
3149 qXfer:libraries:read:
3150 Report the loaded shared libraries. Combined with new "T" packet
3151 response, this packet allows GDB to debug shared libraries on
3152 targets where the operating system manages the list of loaded
3153 libraries (e.g. Windows and SymbianOS).
3157 Support for these obsolete configurations has been removed.
3165 i[34567]86-*-lynxos*
3166 i[34567]86-*-netware*
3167 i[34567]86-*-sco3.2v5*
3168 i[34567]86-*-sco3.2v4*
3170 i[34567]86-*-sysv4.2*
3173 i[34567]86-*-unixware2*
3174 i[34567]86-*-unixware*
3183 * Other removed features
3190 Various m68k-only ROM monitors.
3197 Various Renesas ROM monitors and debugging interfaces for SH and
3202 Support for a Macraigor serial interface to on-chip debugging.
3203 GDB does not directly support the newer parallel or USB
3208 A debug information format. The predecessor to DWARF 2 and
3209 DWARF 3, which are still supported.
3211 Support for the HP aCC compiler on HP-UX/PA-RISC
3213 SOM-encapsulated symbolic debugging information, automatic
3214 invocation of pxdb, and the aCC custom C++ ABI. This does not
3215 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3216 with aCC can still be debugged on an assembly level.
3218 MIPS ".pdr" sections
3220 A MIPS-specific format used to describe stack frame layout
3221 in debugging information.
3225 GDB could work with an older version of Guile to debug
3226 the interpreter and Scheme programs running in it.
3228 set mips stack-arg-size
3229 set mips saved-gpreg-size
3231 Use "set mips abi" to control parameter passing for MIPS.
3233 *** Changes in GDB 6.6
3238 Cell Broadband Engine SPU spu-elf
3240 * GDB can now be configured as a cross-debugger targeting native Windows
3241 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3242 running on a Windows system over TCP/IP to debug Windows programs.
3244 * The GDB remote stub, gdbserver, has been updated to support Windows and
3245 Cygwin debugging. Both single-threaded and multi-threaded programs are
3248 * The "set trust-readonly-sections" command works again. This command was
3249 broken in GDB 6.3, 6.4, and 6.5.
3251 * The "load" command now supports writing to flash memory, if the remote
3252 stub provides the required support.
3254 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3255 longer requires symbolic debug information (e.g. DWARF-2).
3260 unset substitute-path
3261 show substitute-path
3262 Manage a list of substitution rules that GDB uses to rewrite the name
3263 of the directories where the sources are located. This can be useful
3264 for instance when the sources were moved to a different location
3265 between compilation and debugging.
3269 Print each CLI command as it is executed. Each command is prefixed with
3270 a number of `+' symbols representing the nesting depth.
3271 The source command now has a `-v' option to enable the same feature.
3275 The ARM Demon monitor support (RDP protocol, "target rdp").
3277 Kernel Object Display, an embedded debugging feature which only worked with
3278 an obsolete version of Cisco IOS.
3280 The 'set download-write-size' and 'show download-write-size' commands.
3282 * New remote packets
3285 Tell a stub about GDB client features, and request remote target features.
3286 The first feature implemented is PacketSize, which allows the target to
3287 specify the size of packets it can handle - to minimize the number of
3288 packets required and improve performance when connected to a remote
3292 Fetch an OS auxilliary vector from the remote stub. This packet is a
3293 more efficient replacement for qPart:auxv:read.
3295 qXfer:memory-map:read:
3296 Fetch a memory map from the remote stub, including information about
3297 RAM, ROM, and flash memory devices.
3302 Erase and program a flash memory device.
3304 * Removed remote packets
3307 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3308 used it, and only gdbserver implemented it.
3310 *** Changes in GDB 6.5
3314 Renesas M32C/M16C m32c-elf
3316 Morpho Technologies ms1 ms1-elf
3320 init-if-undefined Initialize a convenience variable, but
3321 only if it doesn't already have a value.
3323 The following commands are presently only implemented for native GNU/Linux:
3325 checkpoint Save a snapshot of the program state.
3327 restart <n> Return the program state to a
3328 previously saved state.
3330 info checkpoints List currently saved checkpoints.
3332 delete-checkpoint <n> Delete a previously saved checkpoint.
3334 set|show detach-on-fork Tell gdb whether to detach from a newly
3335 forked process, or to keep debugging it.
3337 info forks List forks of the user program that
3338 are available to be debugged.
3340 fork <n> Switch to debugging one of several
3341 forks of the user program that are
3342 available to be debugged.
3344 delete-fork <n> Delete a fork from the list of forks
3345 that are available to be debugged (and
3346 kill the forked process).
3348 detach-fork <n> Delete a fork from the list of forks
3349 that are available to be debugged (and
3350 allow the process to continue).
3354 Morpho Technologies ms2 ms1-elf
3356 * Improved Windows host support
3358 GDB now builds as a cross debugger hosted on i686-mingw32, including
3359 native console support, and remote communications using either
3360 network sockets or serial ports.
3362 * Improved Modula-2 language support
3364 GDB can now print most types in the Modula-2 syntax. This includes:
3365 basic types, set types, record types, enumerated types, range types,
3366 pointer types and ARRAY types. Procedure var parameters are correctly
3367 printed and hexadecimal addresses and character constants are also
3368 written in the Modula-2 syntax. Best results can be obtained by using
3369 GNU Modula-2 together with the -gdwarf-2 command line option.
3373 The ARM rdi-share module.
3375 The Netware NLM debug server.
3377 *** Changes in GDB 6.4
3379 * New native configurations
3381 OpenBSD/arm arm*-*-openbsd*
3382 OpenBSD/mips64 mips64-*-openbsd*
3386 Morpho Technologies ms1 ms1-elf
3388 * New command line options
3390 --batch-silent As for --batch, but totally silent.
3391 --return-child-result The debugger will exist with the same value
3392 the child (debugged) program exited with.
3393 --eval-command COMMAND, -ex COMMAND
3394 Execute a single GDB CLI command. This may be
3395 specified multiple times and in conjunction
3396 with the --command (-x) option.
3398 * Deprecated commands removed
3400 The following commands, that were deprecated in 2000, have been
3404 set|show arm disassembly-flavor set|show arm disassembler
3405 othernames set arm disassembler
3406 set|show remotedebug set|show debug remote
3407 set|show archdebug set|show debug arch
3408 set|show eventdebug set|show debug event
3411 * New BSD user-level threads support
3413 It is now possible to debug programs using the user-level threads
3414 library on OpenBSD and FreeBSD. Currently supported (target)
3417 FreeBSD/amd64 x86_64-*-freebsd*
3418 FreeBSD/i386 i386-*-freebsd*
3419 OpenBSD/i386 i386-*-openbsd*
3421 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3422 are not yet supported.
3424 * New support for Matsushita MN10300 w/sim added
3425 (Work in progress). mn10300-elf.
3427 * REMOVED configurations and files
3429 VxWorks and the XDR protocol *-*-vxworks
3430 Motorola MCORE mcore-*-*
3431 National Semiconductor NS32000 ns32k-*-*
3433 * New "set print array-indexes" command
3435 After turning this setting "on", GDB prints the index of each element
3436 when displaying arrays. The default is "off" to preserve the previous
3439 * VAX floating point support
3441 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3443 * User-defined command support
3445 In addition to using $arg0..$arg9 for argument passing, it is now possible
3446 to use $argc to determine now many arguments have been passed. See the
3447 section on user-defined commands in the user manual for more information.
3449 *** Changes in GDB 6.3:
3451 * New command line option
3453 GDB now accepts -l followed by a number to set the timeout for remote
3456 * GDB works with GCC -feliminate-dwarf2-dups
3458 GDB now supports a more compact representation of DWARF-2 debug
3459 information using DW_FORM_ref_addr references. These are produced
3460 by GCC with the option -feliminate-dwarf2-dups and also by some
3461 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3462 to use -feliminate-dwarf2-dups.
3464 * Internationalization
3466 When supported by the host system, GDB will be built with
3467 internationalization (libintl). The task of marking up the sources is
3468 continued, we're looking forward to our first translation.
3472 Initial support for debugging programs compiled with the GNAT
3473 implementation of the Ada programming language has been integrated
3474 into GDB. In this release, support is limited to expression evaluation.
3476 * New native configurations
3478 GNU/Linux/m32r m32r-*-linux-gnu
3482 GDB's remote protocol now includes support for the 'p' packet. This
3483 packet is used to fetch individual registers from a remote inferior.
3485 * END-OF-LIFE registers[] compatibility module
3487 GDB's internal register infrastructure has been completely rewritten.
3488 The new infrastructure making possible the implementation of key new
3489 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3492 GDB 6.3 will be the last release to include the the registers[]
3493 compatibility module that allowed out-of-date configurations to
3494 continue to work. This change directly impacts the following
3504 powerpc bdm protocol
3506 Unless there is activity to revive these configurations, they will be
3507 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3509 * OBSOLETE configurations and files
3511 Configurations that have been declared obsolete in this release have
3512 been commented out. Unless there is activity to revive these
3513 configurations, the next release of GDB will have their sources
3514 permanently REMOVED.
3523 *** Changes in GDB 6.2.1:
3525 * MIPS `break main; run' gave an heuristic-fence-post warning
3527 When attempting to run even a simple program, a warning about
3528 heuristic-fence-post being hit would be reported. This problem has
3531 * MIPS IRIX 'long double' crashed GDB
3533 When examining a long double variable, GDB would get a segmentation
3534 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3535 IRIX long double values).
3539 A bug in the VAX stack code was causing problems with the "next"
3540 command. This problem has been fixed.
3542 *** Changes in GDB 6.2:
3544 * Fix for ``many threads''
3546 On GNU/Linux systems that use the NPTL threads library, a program
3547 rapidly creating and deleting threads would confuse GDB leading to the
3550 ptrace: No such process.
3551 thread_db_get_info: cannot get thread info: generic error
3553 This problem has been fixed.
3555 * "-async" and "-noasync" options removed.
3557 Support for the broken "-noasync" option has been removed (it caused
3560 * New ``start'' command.
3562 This command runs the program until the begining of the main procedure.
3564 * New BSD Kernel Data Access Library (libkvm) interface
3566 Using ``target kvm'' it is now possible to debug kernel core dumps and
3567 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3568 platforms. Currently supported (native-only) configurations are:
3570 FreeBSD/amd64 x86_64-*-freebsd*
3571 FreeBSD/i386 i?86-*-freebsd*
3572 NetBSD/i386 i?86-*-netbsd*
3573 NetBSD/m68k m68*-*-netbsd*
3574 NetBSD/sparc sparc-*-netbsd*
3575 OpenBSD/amd64 x86_64-*-openbsd*
3576 OpenBSD/i386 i?86-*-openbsd*
3577 OpenBSD/m68k m68*-openbsd*
3578 OpenBSD/sparc sparc-*-openbsd*
3580 * Signal trampoline code overhauled
3582 Many generic problems with GDB's signal handling code have been fixed.
3583 These include: backtraces through non-contiguous stacks; recognition
3584 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3585 call; backtrace through a signal trampoline; step into and out of
3586 signal handlers; and single-stepping in the signal trampoline.
3588 Please note that kernel bugs are a limiting factor here. These
3589 features have been shown to work on an s390 GNU/Linux system that
3590 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3592 * Cygwin support for DWARF 2 added.
3594 * New native configurations
3596 GNU/Linux/hppa hppa*-*-linux*
3597 OpenBSD/hppa hppa*-*-openbsd*
3598 OpenBSD/m68k m68*-*-openbsd*
3599 OpenBSD/m88k m88*-*-openbsd*
3600 OpenBSD/powerpc powerpc-*-openbsd*
3601 NetBSD/vax vax-*-netbsd*
3602 OpenBSD/vax vax-*-openbsd*
3604 * END-OF-LIFE frame compatibility module
3606 GDB's internal frame infrastructure has been completely rewritten.
3607 The new infrastructure making it possible to support key new features
3608 including DWARF 2 Call Frame Information. To aid in the task of
3609 migrating old configurations to this new infrastructure, a
3610 compatibility module, that allowed old configurations to continue to
3611 work, was also included.
3613 GDB 6.2 will be the last release to include this frame compatibility
3614 module. This change directly impacts the following configurations:
3624 Unless there is activity to revive these configurations, they will be
3625 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3627 * REMOVED configurations and files
3629 Sun 3, running SunOS 3 m68*-*-sunos3*
3630 Sun 3, running SunOS 4 m68*-*-sunos4*
3631 Sun 2, running SunOS 3 m68000-*-sunos3*
3632 Sun 2, running SunOS 4 m68000-*-sunos4*
3633 Motorola 680x0 running LynxOS m68*-*-lynxos*
3634 AT&T 3b1/Unix pc m68*-att-*
3635 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3636 decstation mips-dec-* mips-little-*
3637 riscos mips-*-riscos* mips-*-sysv*
3638 sonymips mips-sony-*
3639 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3641 *** Changes in GDB 6.1.1:
3643 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3645 The TUI (Text-mode User Interface) is now built as part of a default
3646 GDB configuration. It is enabled by either selecting the TUI with the
3647 command line option "-i=tui" or by running the separate "gdbtui"
3648 program. For more information on the TUI, see the manual "Debugging
3651 * Pending breakpoint support (also included in GDB 6.1)
3653 Support has been added to allow you to specify breakpoints in shared
3654 libraries that have not yet been loaded. If a breakpoint location
3655 cannot be found, and the "breakpoint pending" option is set to auto,
3656 GDB queries you if you wish to make the breakpoint pending on a future
3657 shared-library load. If and when GDB resolves the breakpoint symbol,
3658 the pending breakpoint is removed as one or more regular breakpoints
3661 Pending breakpoints are very useful for GCJ Java debugging.
3663 * Fixed ISO-C build problems
3665 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3666 non ISO-C code that stopped them being built using a more strict ISO-C
3667 compiler (e.g., IBM's C compiler).
3669 * Fixed build problem on IRIX 5
3671 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3672 wasn't able to compile compile on an IRIX 5 system.
3674 * Added execute permission to gdb/gdbserver/configure
3676 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3677 permission. This bug would cause configure to fail on a number of
3678 systems (Solaris, IRIX). Ref: server/519.
3680 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3682 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3683 has been updated to use constant array sizes.
3685 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3687 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3688 its generated DWARF Call Frame Info. This encoding was causing GDB to
3689 panic, that panic has been fixed. Ref: gdb/1628.
3691 * Fixed a problem when examining parameters in shared library code.
3693 When examining parameters in optimized shared library code generated
3694 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3695 not available''. GDB now correctly displays the variable's value.
3697 *** Changes in GDB 6.1:
3699 * Removed --with-mmalloc
3701 Support for the mmalloc memory manager has been removed, as it
3702 conflicted with the internal gdb byte cache.
3704 * Changes in AMD64 configurations
3706 The AMD64 target now includes the %cs and %ss registers. As a result
3707 the AMD64 remote protocol has changed; this affects the floating-point
3708 and SSE registers. If you rely on those registers for your debugging,
3709 you should upgrade gdbserver on the remote side.
3711 * Revised SPARC target
3713 The SPARC target has been completely revised, incorporating the
3714 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3715 support for LynxOS and SunOS 4 has been dropped. Calling functions
3716 from within GDB on operating systems with a non-executable stack
3717 (Solaris, OpenBSD) now works.
3721 GDB has a new C++ demangler which does a better job on the mangled
3722 names generated by current versions of g++. It also runs faster, so
3723 with this and other changes gdb should now start faster on large C++
3726 * DWARF 2 Location Expressions
3728 GDB support for location expressions has been extended to support function
3729 arguments and frame bases. Older versions of GDB could crash when they
3732 * C++ nested types and namespaces
3734 GDB's support for nested types and namespaces in C++ has been
3735 improved, especially if you use the DWARF 2 debugging format. (This
3736 is the default for recent versions of GCC on most platforms.)
3737 Specifically, if you have a class "Inner" defined within a class or
3738 namespace "Outer", then GDB realizes that the class's name is
3739 "Outer::Inner", not simply "Inner". This should greatly reduce the
3740 frequency of complaints about not finding RTTI symbols. In addition,
3741 if you are stopped at inside of a function defined within a namespace,
3742 GDB modifies its name lookup accordingly.
3744 * New native configurations
3746 NetBSD/amd64 x86_64-*-netbsd*
3747 OpenBSD/amd64 x86_64-*-openbsd*
3748 OpenBSD/alpha alpha*-*-openbsd*
3749 OpenBSD/sparc sparc-*-openbsd*
3750 OpenBSD/sparc64 sparc64-*-openbsd*
3752 * New debugging protocols
3754 M32R with SDI protocol m32r-*-elf*
3756 * "set prompt-escape-char" command deleted.
3758 The command "set prompt-escape-char" has been deleted. This command,
3759 and its very obscure effet on GDB's prompt, was never documented,
3760 tested, nor mentioned in the NEWS file.
3762 * OBSOLETE configurations and files
3764 Configurations that have been declared obsolete in this release have
3765 been commented out. Unless there is activity to revive these
3766 configurations, the next release of GDB will have their sources
3767 permanently REMOVED.
3769 Sun 3, running SunOS 3 m68*-*-sunos3*
3770 Sun 3, running SunOS 4 m68*-*-sunos4*
3771 Sun 2, running SunOS 3 m68000-*-sunos3*
3772 Sun 2, running SunOS 4 m68000-*-sunos4*
3773 Motorola 680x0 running LynxOS m68*-*-lynxos*
3774 AT&T 3b1/Unix pc m68*-att-*
3775 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3776 decstation mips-dec-* mips-little-*
3777 riscos mips-*-riscos* mips-*-sysv*
3778 sonymips mips-sony-*
3779 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3781 * REMOVED configurations and files
3783 SGI Irix-4.x mips-sgi-irix4 or iris4
3784 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3785 Z8000 simulator z8k-zilog-none or z8ksim
3786 Matsushita MN10200 w/simulator mn10200-*-*
3787 H8/500 simulator h8500-hitachi-hms or h8500hms
3788 HP/PA running BSD hppa*-*-bsd*
3789 HP/PA running OSF/1 hppa*-*-osf*
3790 HP/PA Pro target hppa*-*-pro*
3791 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3792 386BSD i[3456]86-*-bsd*
3793 Sequent family i[3456]86-sequent-sysv4*
3794 i[3456]86-sequent-sysv*
3795 i[3456]86-sequent-bsd*
3796 SPARC running LynxOS sparc-*-lynxos*
3797 SPARC running SunOS 4 sparc-*-sunos4*
3798 Tsqware Sparclet sparclet-*-*
3799 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3801 *** Changes in GDB 6.0:
3805 Support for debugging the Objective-C programming language has been
3806 integrated into GDB.
3808 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3810 DWARF 2's Call Frame Information makes available compiler generated
3811 information that more exactly describes the program's run-time stack.
3812 By using this information, GDB is able to provide more robust stack
3815 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3816 have been updated to use a new backtrace mechanism which includes
3817 DWARF 2 CFI support.
3821 GDB's remote protocol has been extended to include support for hosted
3822 file I/O (where the remote target uses GDB's file system). See GDB's
3823 remote protocol documentation for details.
3825 * All targets using the new architecture framework.
3827 All of GDB's targets have been updated to use the new internal
3828 architecture framework. The way is now open for future GDB releases
3829 to include cross-architecture native debugging support (i386 on amd64,
3832 * GNU/Linux's Thread Local Storage (TLS)
3834 GDB now includes support for for the GNU/Linux implementation of
3835 per-thread variables.
3837 * GNU/Linux's Native POSIX Thread Library (NPTL)
3839 GDB's thread code has been updated to work with either the new
3840 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3842 * Separate debug info.
3844 GDB, in conjunction with BINUTILS, now supports a mechanism for
3845 automatically loading debug information from a separate file. Instead
3846 of shipping full debug and non-debug versions of system libraries,
3847 system integrators can now instead ship just the stripped libraries
3848 and optional debug files.
3850 * DWARF 2 Location Expressions
3852 DWARF 2 Location Expressions allow the compiler to more completely
3853 describe the location of variables (even in optimized code) to the
3856 GDB now includes preliminary support for location expressions (support
3857 for DW_OP_piece is still missing).
3861 A number of long standing bugs that caused GDB to die while starting a
3862 Java application have been fixed. GDB's Java support is now
3863 considered "useable".
3865 * GNU/Linux support for fork, vfork, and exec.
3867 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3868 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3871 * GDB supports logging output to a file
3873 There are two new commands, "set logging" and "show logging", which can be
3874 used to capture GDB's output to a file.
3876 * The meaning of "detach" has changed for gdbserver
3878 The "detach" command will now resume the application, as documented. To
3879 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3882 * d10v, m68hc11 `regs' command deprecated
3884 The `info registers' command has been updated so that it displays the
3885 registers using a format identical to the old `regs' command.
3889 A new command, "maint set profile on/off", has been added. This command can
3890 be used to enable or disable profiling while running GDB, to profile a
3891 session or a set of commands. In addition there is a new configure switch,
3892 "--enable-profiling", which will cause GDB to be compiled with profiling
3893 data, for more informative profiling results.
3895 * Default MI syntax changed to "mi2".
3897 The default MI (machine interface) syntax, enabled by the command line
3898 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3899 "mi1", can be enabled by specifying the option "-i=mi1".
3901 Support for the original "mi0" syntax (included in GDB 5.0) has been
3904 Fix for gdb/192: removed extraneous space when displaying frame level.
3905 Fix for gdb/672: update changelist is now output in mi list format.
3906 Fix for gdb/702: a -var-assign that updates the value now shows up
3907 in a subsequent -var-update.
3909 * New native configurations.
3911 FreeBSD/amd64 x86_64-*-freebsd*
3913 * Multi-arched targets.
3915 HP/PA HPUX11 hppa*-*-hpux*
3916 Renesas M32R/D w/simulator m32r-*-elf*
3918 * OBSOLETE configurations and files
3920 Configurations that have been declared obsolete in this release have
3921 been commented out. Unless there is activity to revive these
3922 configurations, the next release of GDB will have their sources
3923 permanently REMOVED.
3925 Z8000 simulator z8k-zilog-none or z8ksim
3926 Matsushita MN10200 w/simulator mn10200-*-*
3927 H8/500 simulator h8500-hitachi-hms or h8500hms
3928 HP/PA running BSD hppa*-*-bsd*
3929 HP/PA running OSF/1 hppa*-*-osf*
3930 HP/PA Pro target hppa*-*-pro*
3931 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3932 Sequent family i[3456]86-sequent-sysv4*
3933 i[3456]86-sequent-sysv*
3934 i[3456]86-sequent-bsd*
3935 Tsqware Sparclet sparclet-*-*
3936 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3938 * REMOVED configurations and files
3941 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3942 IBM AIX PS/2 i[3456]86-*-aix
3943 i386 running Mach 3.0 i[3456]86-*-mach3*
3944 i386 running Mach i[3456]86-*-mach*
3945 i386 running OSF/1 i[3456]86-*osf1mk*
3946 HP/Apollo 68k Family m68*-apollo*-sysv*,
3948 m68*-hp-bsd*, m68*-hp-hpux*
3949 Argonaut Risc Chip (ARC) arc-*-*
3950 Mitsubishi D30V d30v-*-*
3951 Fujitsu FR30 fr30-*-elf*
3952 OS/9000 i[34]86-*-os9k
3953 I960 with MON960 i960-*-coff
3955 * MIPS $fp behavior changed
3957 The convenience variable $fp, for the MIPS, now consistently returns
3958 the address of the current frame's base. Previously, depending on the
3959 context, $fp could refer to either $sp or the current frame's base
3960 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3961 The GNU Source-Level Debugger''.
3963 *** Changes in GDB 5.3:
3965 * GNU/Linux shared library multi-threaded performance improved.
3967 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3968 `/proc', in preference to `ptrace' for memory reads. This may result
3969 in an improvement in the start-up time of multi-threaded, shared
3970 library applications when run under GDB. One GDB user writes: ``loads
3971 shared libs like mad''.
3973 * ``gdbserver'' now supports multi-threaded applications on some targets
3975 Support for debugging multi-threaded applications which use
3976 the GNU/Linux LinuxThreads package has been added for
3977 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3978 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3980 * GDB now supports C/C++ preprocessor macros.
3982 GDB now expands preprocessor macro invocations in C/C++ expressions,
3983 and provides various commands for showing macro definitions and how
3986 The new command `macro expand EXPRESSION' expands any macro
3987 invocations in expression, and shows the result.
3989 The new command `show macro MACRO-NAME' shows the definition of the
3990 macro named MACRO-NAME, and where it was defined.
3992 Most compilers don't include information about macros in the debugging
3993 information by default. In GCC 3.1, for example, you need to compile
3994 your program with the options `-gdwarf-2 -g3'. If the macro
3995 information is present in the executable, GDB will read it.
3997 * Multi-arched targets.
3999 DEC Alpha (partial) alpha*-*-*
4000 DEC VAX (partial) vax-*-*
4002 National Semiconductor NS32000 (partial) ns32k-*-*
4003 Motorola 68000 (partial) m68k-*-*
4004 Motorola MCORE mcore-*-*
4008 Fujitsu FRV architecture added by Red Hat frv*-*-*
4011 * New native configurations
4013 Alpha NetBSD alpha*-*-netbsd*
4014 SH NetBSD sh*-*-netbsdelf*
4015 MIPS NetBSD mips*-*-netbsd*
4016 UltraSPARC NetBSD sparc64-*-netbsd*
4018 * OBSOLETE configurations and files
4020 Configurations that have been declared obsolete in this release have
4021 been commented out. Unless there is activity to revive these
4022 configurations, the next release of GDB will have their sources
4023 permanently REMOVED.
4025 Mitsubishi D30V d30v-*-*
4026 OS/9000 i[34]86-*-os9k
4027 IBM AIX PS/2 i[3456]86-*-aix
4028 Fujitsu FR30 fr30-*-elf*
4029 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4030 Argonaut Risc Chip (ARC) arc-*-*
4031 i386 running Mach 3.0 i[3456]86-*-mach3*
4032 i386 running Mach i[3456]86-*-mach*
4033 i386 running OSF/1 i[3456]86-*osf1mk*
4034 HP/Apollo 68k Family m68*-apollo*-sysv*,
4036 m68*-hp-bsd*, m68*-hp-hpux*
4037 I960 with MON960 i960-*-coff
4039 * OBSOLETE languages
4041 CHILL, a Pascal like language used by telecommunications companies.
4043 * REMOVED configurations and files
4045 AMD 29k family via UDI a29k-amd-udi, udi29k
4046 A29K VxWorks a29k-*-vxworks
4047 AMD 29000 embedded, using EBMON a29k-none-none
4048 AMD 29000 embedded with COFF a29k-none-coff
4049 AMD 29000 embedded with a.out a29k-none-aout
4051 testsuite/gdb.hp/gdb.threads-hp/ directory
4053 * New command "set max-user-call-depth <nnn>"
4055 This command allows the user to limit the call depth of user-defined
4056 commands. The default is 1024.
4058 * Changes in FreeBSD/i386 native debugging.
4060 Support for the "generate-core-file" has been added.
4062 * New commands "dump", "append", and "restore".
4064 These commands allow data to be copied from target memory
4065 to a bfd-format or binary file (dump and append), and back
4066 from a file into memory (restore).
4068 * Improved "next/step" support on multi-processor Alpha Tru64.
4070 The previous single-step mechanism could cause unpredictable problems,
4071 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4072 of a software single-step mechanism prevents this.
4074 *** Changes in GDB 5.2.1:
4082 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4083 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4084 Fix, by Joel Brobecker imported from mainline.
4086 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4087 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4088 Fix, by Fred Fish, imported from mainline.
4090 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4091 Surprisingly enough, it works now.
4092 By Michal Ludvig, imported from mainline.
4094 i386 hardware watchpoint support:
4095 avoid misses on second run for some targets.
4096 By Pierre Muller, imported from mainline.
4098 *** Changes in GDB 5.2:
4100 * New command "set trust-readonly-sections on[off]".
4102 This command is a hint that tells gdb that read-only sections
4103 really are read-only (ie. that their contents will not change).
4104 In this mode, gdb will go to the object file rather than the
4105 target to read memory from read-only sections (such as ".text").
4106 This can be a significant performance improvement on some
4107 (notably embedded) targets.
4109 * New command "generate-core-file" (or "gcore").
4111 This new gdb command allows the user to drop a core file of the child
4112 process state at any time. So far it's been implemented only for
4113 GNU/Linux and Solaris, but should be relatively easily ported to other
4114 hosts. Argument is core file name (defaults to core.<pid>).
4116 * New command line option
4118 GDB now accepts --pid or -p followed by a process id.
4120 * Change in command line behavior -- corefiles vs. process ids.
4122 There is a subtle behavior in the way in which GDB handles
4123 command line arguments. The first non-flag argument is always
4124 a program to debug, but the second non-flag argument may either
4125 be a corefile or a process id. Previously, GDB would attempt to
4126 open the second argument as a corefile, and if that failed, would
4127 issue a superfluous error message and then attempt to attach it as
4128 a process. Now, if the second argument begins with a non-digit,
4129 it will be treated as a corefile. If it begins with a digit,
4130 GDB will attempt to attach it as a process, and if no such process
4131 is found, will then attempt to open it as a corefile.
4133 * Changes in ARM configurations.
4135 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4136 configuration is fully multi-arch.
4138 * New native configurations
4140 ARM NetBSD arm*-*-netbsd*
4141 x86 OpenBSD i[3456]86-*-openbsd*
4142 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4143 Sparc64 running FreeBSD sparc64-*-freebsd*
4147 Sanyo XStormy16 xstormy16-elf
4149 * OBSOLETE configurations and files
4151 Configurations that have been declared obsolete in this release have
4152 been commented out. Unless there is activity to revive these
4153 configurations, the next release of GDB will have their sources
4154 permanently REMOVED.
4156 AMD 29k family via UDI a29k-amd-udi, udi29k
4157 A29K VxWorks a29k-*-vxworks
4158 AMD 29000 embedded, using EBMON a29k-none-none
4159 AMD 29000 embedded with COFF a29k-none-coff
4160 AMD 29000 embedded with a.out a29k-none-aout
4162 testsuite/gdb.hp/gdb.threads-hp/ directory
4164 * REMOVED configurations and files
4166 TI TMS320C80 tic80-*-*
4168 PowerPC Solaris powerpcle-*-solaris*
4169 PowerPC Windows NT powerpcle-*-cygwin32
4170 PowerPC Netware powerpc-*-netware*
4171 Harris/CXUX m88k m88*-harris-cxux*
4172 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4173 ns32k-utek-sysv* ns32k-utek-*
4174 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4175 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4176 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4177 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4178 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4180 * Changes to command line processing
4182 The new `--args' feature can be used to specify command-line arguments
4183 for the inferior from gdb's command line.
4185 * Changes to key bindings
4187 There is a new `operate-and-get-next' function bound to `C-o'.
4189 *** Changes in GDB 5.1.1
4191 Fix compile problem on DJGPP.
4193 Fix a problem with floating-point registers on the i386 being
4196 Fix to stop GDB crashing on .debug_str debug info.
4198 Numerous documentation fixes.
4200 Numerous testsuite fixes.
4202 *** Changes in GDB 5.1:
4204 * New native configurations
4206 Alpha FreeBSD alpha*-*-freebsd*
4207 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4208 MIPS GNU/Linux mips*-*-linux*
4209 MIPS SGI Irix 6.x mips*-sgi-irix6*
4210 ia64 AIX ia64-*-aix*
4211 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4215 Motorola 68HC11 and 68HC12 m68hc11-elf
4217 UltraSparc running GNU/Linux sparc64-*-linux*
4219 * OBSOLETE configurations and files
4221 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4222 Harris/CXUX m88k m88*-harris-cxux*
4223 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4224 ns32k-utek-sysv* ns32k-utek-*
4225 TI TMS320C80 tic80-*-*
4227 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4228 PowerPC Solaris powerpcle-*-solaris*
4229 PowerPC Windows NT powerpcle-*-cygwin32
4230 PowerPC Netware powerpc-*-netware*
4231 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4232 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4233 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4234 Apple Macintosh (MPW) host N/A
4236 stuff.c (Program to stuff files into a specially prepared space in kdb)
4237 kdb-start.c (Main loop for the standalone kernel debugger)
4239 Configurations that have been declared obsolete in this release have
4240 been commented out. Unless there is activity to revive these
4241 configurations, the next release of GDB will have their sources
4242 permanently REMOVED.
4244 * REMOVED configurations and files
4246 Altos 3068 m68*-altos-*
4247 Convex c1-*-*, c2-*-*
4249 ARM RISCix arm-*-* (as host)
4253 * GDB has been converted to ISO C.
4255 GDB's source code has been converted to ISO C. In particular, the
4256 sources are fully protoized, and rely on standard headers being
4261 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4263 * The MI enabled by default.
4265 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4266 revised and enabled by default. Packages which use GDB as a debugging
4267 engine behind a UI or another front end are encouraged to switch to
4268 using the GDB/MI interface, instead of the old annotations interface
4269 which is now deprecated.
4271 * Support for debugging Pascal programs.
4273 GDB now includes support for debugging Pascal programs. The following
4274 main features are supported:
4276 - Pascal-specific data types such as sets;
4278 - automatic recognition of Pascal sources based on file-name
4281 - Pascal-style display of data types, variables, and functions;
4283 - a Pascal expression parser.
4285 However, some important features are not yet supported.
4287 - Pascal string operations are not supported at all;
4289 - there are some problems with boolean types;
4291 - Pascal type hexadecimal constants are not supported
4292 because they conflict with the internal variables format;
4294 - support for Pascal objects and classes is not full yet;
4296 - unlike Pascal, GDB is case-sensitive for symbol names.
4298 * Changes in completion.
4300 Commands such as `shell', `run' and `set args', which pass arguments
4301 to inferior programs, now complete on file names, similar to what
4302 users expect at the shell prompt.
4304 Commands which accept locations, such as `disassemble', `print',
4305 `breakpoint', `until', etc. now complete on filenames as well as
4306 program symbols. Thus, if you type "break foob TAB", and the source
4307 files linked into the programs include `foobar.c', that file name will
4308 be one of the candidates for completion. However, file names are not
4309 considered for completion after you typed a colon that delimits a file
4310 name from a name of a function in that file, as in "break foo.c:bar".
4312 `set demangle-style' completes on available demangling styles.
4314 * New platform-independent commands:
4316 It is now possible to define a post-hook for a command as well as a
4317 hook that runs before the command. For more details, see the
4318 documentation of `hookpost' in the GDB manual.
4320 * Changes in GNU/Linux native debugging.
4322 Support for debugging multi-threaded programs has been completely
4323 revised for all platforms except m68k and sparc. You can now debug as
4324 many threads as your system allows you to have.
4326 Attach/detach is supported for multi-threaded programs.
4328 Support for SSE registers was added for x86. This doesn't work for
4329 multi-threaded programs though.
4331 * Changes in MIPS configurations.
4333 Multi-arch support is enabled for all MIPS configurations.
4335 GDB can now be built as native debugger on SGI Irix 6.x systems for
4336 debugging n32 executables. (Debugging 64-bit executables is not yet
4339 * Unified support for hardware watchpoints in all x86 configurations.
4341 Most (if not all) native x86 configurations support hardware-assisted
4342 breakpoints and watchpoints in a unified manner. This support
4343 implements debug register sharing between watchpoints, which allows to
4344 put a virtually infinite number of watchpoints on the same address,
4345 and also supports watching regions up to 16 bytes with several debug
4348 The new maintenance command `maintenance show-debug-regs' toggles
4349 debugging print-outs in functions that insert, remove, and test
4350 watchpoints and hardware breakpoints.
4352 * Changes in the DJGPP native configuration.
4354 New command ``info dos sysinfo'' displays assorted information about
4355 the CPU, OS, memory, and DPMI server.
4357 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4358 display information about segment descriptors stored in GDT, LDT, and
4361 New commands ``info dos pde'' and ``info dos pte'' display entries
4362 from Page Directory and Page Tables (for now works with CWSDPMI only).
4363 New command ``info dos address-pte'' displays the Page Table entry for
4364 a given linear address.
4366 GDB can now pass command lines longer than 126 characters to the
4367 program being debugged (requires an update to the libdbg.a library
4368 which is part of the DJGPP development kit).
4370 DWARF2 debug info is now supported.
4372 It is now possible to `step' and `next' through calls to `longjmp'.
4374 * Changes in documentation.
4376 All GDB documentation was converted to GFDL, the GNU Free
4377 Documentation License.
4379 Tracepoints-related commands are now fully documented in the GDB
4382 TUI, the Text-mode User Interface, is now documented in the manual.
4384 Tracepoints-related commands are now fully documented in the GDB
4387 The "GDB Internals" manual now has an index. It also includes
4388 documentation of `ui_out' functions, GDB coding standards, x86
4389 hardware watchpoints, and memory region attributes.
4391 * GDB's version number moved to ``version.in''
4393 The Makefile variable VERSION has been replaced by the file
4394 ``version.in''. People creating GDB distributions should update the
4395 contents of this file.
4399 GUD support is now a standard part of the EMACS distribution.
4401 *** Changes in GDB 5.0:
4403 * Improved support for debugging FP programs on x86 targets
4405 Unified and much-improved support for debugging floating-point
4406 programs on all x86 targets. In particular, ``info float'' now
4407 displays the FP registers in the same format on all x86 targets, with
4408 greater level of detail.
4410 * Improvements and bugfixes in hardware-assisted watchpoints
4412 It is now possible to watch array elements, struct members, and
4413 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4414 on x86 targets no longer erroneously trigger when the address is
4417 * Improvements in the native DJGPP version of GDB
4419 The distribution now includes all the scripts and auxiliary files
4420 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4421 machines ``out of the box''.
4423 The DJGPP version can now debug programs that use signals. It is
4424 possible to catch signals that happened in the debuggee, deliver
4425 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4426 would kill the program being debugged.) Programs that hook hardware
4427 interrupts (keyboard, timer, etc.) can also be debugged.
4429 It is now possible to debug DJGPP programs that redirect their
4430 standard handles or switch them to raw (as opposed to cooked) mode, or
4431 even close them. The command ``run < foo > bar'' works as expected,
4432 and ``info terminal'' reports useful information about the debuggee's
4433 terminal, including raw/cooked mode, redirection, etc.
4435 The DJGPP version now uses termios functions for console I/O, which
4436 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4439 DOS-style file names with drive letters are now fully supported by
4442 It is now possible to debug DJGPP programs that switch their working
4443 directory. It is also possible to rerun the debuggee any number of
4444 times without restarting GDB; thus, you can use the same setup,
4445 breakpoints, etc. for many debugging sessions.
4447 * New native configurations
4449 ARM GNU/Linux arm*-*-linux*
4450 PowerPC GNU/Linux powerpc-*-linux*
4454 Motorola MCore mcore-*-*
4455 x86 VxWorks i[3456]86-*-vxworks*
4456 PowerPC VxWorks powerpc-*-vxworks*
4457 TI TMS320C80 tic80-*-*
4459 * OBSOLETE configurations
4461 Altos 3068 m68*-altos-*
4462 Convex c1-*-*, c2-*-*
4464 ARM RISCix arm-*-* (as host)
4467 Configurations that have been declared obsolete will be commented out,
4468 but the code will be left in place. If there is no activity to revive
4469 these configurations before the next release of GDB, the sources will
4470 be permanently REMOVED.
4472 * Gould support removed
4474 Support for the Gould PowerNode and NP1 has been removed.
4476 * New features for SVR4
4478 On SVR4 native platforms (such as Solaris), if you attach to a process
4479 without first loading a symbol file, GDB will now attempt to locate and
4480 load symbols from the running process's executable file.
4482 * Many C++ enhancements
4484 C++ support has been greatly improved. Overload resolution now works properly
4485 in almost all cases. RTTI support is on the way.
4487 * Remote targets can connect to a sub-program
4489 A popen(3) style serial-device has been added. This device starts a
4490 sub-process (such as a stand-alone simulator) and then communicates
4491 with that. The sub-program to run is specified using the syntax
4492 ``|<program> <args>'' vis:
4494 (gdb) set remotedebug 1
4495 (gdb) target extended-remote |mn10300-elf-sim program-args
4497 * MIPS 64 remote protocol
4499 A long standing bug in the mips64 remote protocol where by GDB
4500 expected certain 32 bit registers (ex SR) to be transfered as 32
4501 instead of 64 bits has been fixed.
4503 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4504 added to provide backward compatibility with older versions of GDB.
4506 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4508 The command ``set remotebinarydownload'' command has been replaced by
4509 ``set remote X-packet''. Other commands in ``set remote'' family
4510 include ``set remote P-packet''.
4512 * Breakpoint commands accept ranges.
4514 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4515 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4516 ``tracepoint passcount'' also accepts a range of tracepoints.
4518 * ``apropos'' command added.
4520 The ``apropos'' command searches through command names and
4521 documentation strings, printing out matches, making it much easier to
4522 try to find a command that does what you are looking for.
4526 A new machine oriented interface (MI) has been added to GDB. This
4527 interface is designed for debug environments running GDB as a separate
4528 process. This is part of the long term libGDB project. See the
4529 "GDB/MI" chapter of the GDB manual for further information. It can be
4530 enabled by configuring with:
4532 .../configure --enable-gdbmi
4534 *** Changes in GDB-4.18:
4536 * New native configurations
4538 HP-UX 10.20 hppa*-*-hpux10.20
4539 HP-UX 11.x hppa*-*-hpux11.0*
4540 M68K GNU/Linux m68*-*-linux*
4544 Fujitsu FR30 fr30-*-elf*
4545 Intel StrongARM strongarm-*-*
4546 Mitsubishi D30V d30v-*-*
4548 * OBSOLETE configurations
4550 Gould PowerNode, NP1 np1-*-*, pn-*-*
4552 Configurations that have been declared obsolete will be commented out,
4553 but the code will be left in place. If there is no activity to revive
4554 these configurations before the next release of GDB, the sources will
4555 be permanently REMOVED.
4559 As a compatibility experiment, GDB's source files buildsym.h and
4560 buildsym.c have been converted to pure standard C, no longer
4561 containing any K&R compatibility code. We believe that all systems in
4562 use today either come with a standard C compiler, or have a GCC port
4563 available. If this is not true, please report the affected
4564 configuration to bug-gdb@gnu.org immediately. See the README file for
4565 information about getting a standard C compiler if you don't have one
4570 GDB now uses readline 2.2.
4572 * set extension-language
4574 You can now control the mapping between filename extensions and source
4575 languages by using the `set extension-language' command. For instance,
4576 you can ask GDB to treat .c files as C++ by saying
4577 set extension-language .c c++
4578 The command `info extensions' lists all of the recognized extensions
4579 and their associated languages.
4581 * Setting processor type for PowerPC and RS/6000
4583 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4584 you can use the `set processor' command to specify what variant of the
4585 PowerPC family you are debugging. The command
4589 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4590 following PowerPC and RS6000 variants:
4592 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4593 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4595 403GC IBM PowerPC 403GC
4596 505 Motorola PowerPC 505
4597 860 Motorola PowerPC 860 or 850
4598 601 Motorola PowerPC 601
4599 602 Motorola PowerPC 602
4600 603 Motorola/IBM PowerPC 603 or 603e
4601 604 Motorola PowerPC 604 or 604e
4602 750 Motorola/IBM PowerPC 750 or 750
4604 At the moment, this command just tells GDB what to name the
4605 special-purpose processor registers. Since almost all the affected
4606 registers are inaccessible to user-level programs, this command is
4607 only useful for remote debugging in its present form.
4611 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4612 more extensive support for HP-UX. Added features include shared
4613 library support, kernel threads and hardware watchpoints for 11.00,
4614 support for HP's ANSI C and C++ compilers, and a compatibility mode
4615 for xdb and dbx commands.
4619 HP's donation includes the new concept of catchpoints, which is a
4620 generalization of the old catch command. On HP-UX, it is now possible
4621 to catch exec, fork, and vfork, as well as library loading.
4623 This means that the existing catch command has changed; its first
4624 argument now specifies the type of catch to be set up. See the
4625 output of "help catch" for a list of catchpoint types.
4627 * Debugging across forks
4629 On HP-UX, you can choose which process to debug when a fork() happens
4634 HP has donated a curses-based terminal user interface (TUI). To get
4635 it, build with --enable-tui. Although this can be enabled for any
4636 configuration, at present it only works for native HP debugging.
4638 * GDB remote protocol additions
4640 A new protocol packet 'X' that writes binary data is now available.
4641 Default behavior is to try 'X', then drop back to 'M' if the stub
4642 fails to respond. The settable variable `remotebinarydownload'
4643 allows explicit control over the use of 'X'.
4645 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4646 full 64-bit address. The command
4648 set remoteaddresssize 32
4650 can be used to revert to the old behaviour. For existing remote stubs
4651 the change should not be noticed, as the additional address information
4654 In order to assist in debugging stubs, you may use the maintenance
4655 command `packet' to send any text string to the stub. For instance,
4657 maint packet heythere
4659 sends the packet "$heythere#<checksum>". Note that it is very easy to
4660 disrupt a debugging session by sending the wrong packet at the wrong
4663 The compare-sections command allows you to compare section data on the
4664 target to what is in the executable file without uploading or
4665 downloading, by comparing CRC checksums.
4667 * Tracing can collect general expressions
4669 You may now collect general expressions at tracepoints. This requires
4670 further additions to the target-side stub; see tracepoint.c and
4671 doc/agentexpr.texi for further details.
4673 * mask-address variable for Mips
4675 For Mips targets, you may control the zeroing of the upper 32 bits of
4676 a 64-bit address by entering `set mask-address on'. This is mainly
4677 of interest to users of embedded R4xxx and R5xxx processors.
4679 * Higher serial baud rates
4681 GDB's serial code now allows you to specify baud rates 57600, 115200,
4682 230400, and 460800 baud. (Note that your host system may not be able
4683 to achieve all of these rates.)
4687 The i960 configuration now includes an initial implementation of a
4688 builtin simulator, contributed by Jim Wilson.
4691 *** Changes in GDB-4.17:
4693 * New native configurations
4695 Alpha GNU/Linux alpha*-*-linux*
4696 Unixware 2.x i[3456]86-unixware2*
4697 Irix 6.x mips*-sgi-irix6*
4698 PowerPC GNU/Linux powerpc-*-linux*
4699 PowerPC Solaris powerpcle-*-solaris*
4700 Sparc GNU/Linux sparc-*-linux*
4701 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4705 Argonaut Risc Chip (ARC) arc-*-*
4706 Hitachi H8/300S h8300*-*-*
4707 Matsushita MN10200 w/simulator mn10200-*-*
4708 Matsushita MN10300 w/simulator mn10300-*-*
4709 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4710 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4711 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4712 Mitsubishi D10V w/simulator d10v-*-*
4713 Mitsubishi M32R/D w/simulator m32r-*-elf*
4714 Tsqware Sparclet sparclet-*-*
4715 NEC V850 w/simulator v850-*-*
4717 * New debugging protocols
4719 ARM with RDI protocol arm*-*-*
4720 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4721 DDB and LSI variants of PMON protocol mips*-*-*
4722 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4723 PowerPC with SDS protocol powerpc{,le}-*-eabi
4724 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4728 All configurations can now understand and use the DWARF 2 debugging
4729 format. The choice is automatic, if the symbol file contains DWARF 2
4734 GDB now includes basic Java language support. This support is
4735 only useful with Java compilers that produce native machine code.
4737 * solib-absolute-prefix and solib-search-path
4739 For SunOS and SVR4 shared libraries, you may now set the prefix for
4740 loading absolute shared library symbol files, and the search path for
4741 locating non-absolute shared library symbol files.
4743 * Live range splitting
4745 GDB can now effectively debug code for which GCC has performed live
4746 range splitting as part of its optimization. See gdb/doc/LRS for
4747 more details on the expected format of the stabs information.
4751 GDB's support for the GNU Hurd, including thread debugging, has been
4752 updated to work with current versions of the Hurd.
4756 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4757 instruction set. ARM GDB automatically detects when Thumb
4758 instructions are in use, and adjusts disassembly and backtracing
4763 GDB's MIPS target configurations now handle the MIP16 16-bit
4768 GDB now includes support for overlays; if an executable has been
4769 linked such that multiple sections are based at the same address, GDB
4770 will decide which section to use for symbolic info. You can choose to
4771 control the decision manually, using overlay commands, or implement
4772 additional target-side support and use "overlay load-target" to bring
4773 in the overlay mapping. Do "help overlay" for more detail.
4777 The command "info symbol <address>" displays information about
4778 the symbol at the specified address.
4782 The standard remote protocol now includes an extension that allows
4783 asynchronous collection and display of trace data. This requires
4784 extensive support in the target-side debugging stub. Tracing mode
4785 includes a new interaction mode in GDB and new commands: see the
4786 file tracepoint.c for more details.
4790 Configurations for embedded MIPS now include a simulator contributed
4791 by Cygnus Solutions. The simulator supports the instruction sets
4792 of most MIPS variants.
4796 Sparc configurations may now include the ERC32 simulator contributed
4797 by the European Space Agency. The simulator is not built into
4798 Sparc targets by default; configure with --enable-sim to include it.
4802 For target configurations that may include multiple variants of a
4803 basic architecture (such as MIPS and SH), you may now set the
4804 architecture explicitly. "set arch" sets, "info arch" lists
4805 the possible architectures.
4807 *** Changes in GDB-4.16:
4809 * New native configurations
4811 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4812 M68K NetBSD m68k-*-netbsd*
4813 PowerPC AIX 4.x powerpc-*-aix*
4814 PowerPC MacOS powerpc-*-macos*
4815 PowerPC Windows NT powerpcle-*-cygwin32
4816 RS/6000 AIX 4.x rs6000-*-aix4*
4820 ARM with RDP protocol arm-*-*
4821 I960 with MON960 i960-*-coff
4822 MIPS VxWorks mips*-*-vxworks*
4823 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4824 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4826 Matra Sparclet sparclet-*-*
4830 The powerpc-eabi configuration now includes the PSIM simulator,
4831 contributed by Andrew Cagney, with assistance from Mike Meissner.
4832 PSIM is a very elaborate model of the PowerPC, including not only
4833 basic instruction set execution, but also details of execution unit
4834 performance and I/O hardware. See sim/ppc/README for more details.
4838 GDB now works with Solaris 2.5.
4840 * Windows 95/NT native
4842 GDB will now work as a native debugger on Windows 95 and Windows NT.
4843 To build it from source, you must use the "gnu-win32" environment,
4844 which uses a DLL to emulate enough of Unix to run the GNU tools.
4845 Further information, binaries, and sources are available at
4846 ftp.cygnus.com, under pub/gnu-win32.
4848 * dont-repeat command
4850 If a user-defined command includes the command `dont-repeat', then the
4851 command will not be repeated if the user just types return. This is
4852 useful if the command is time-consuming to run, so that accidental
4853 extra keystrokes don't run the same command many times.
4855 * Send break instead of ^C
4857 The standard remote protocol now includes an option to send a break
4858 rather than a ^C to the target in order to interrupt it. By default,
4859 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4861 * Remote protocol timeout
4863 The standard remote protocol includes a new variable `remotetimeout'
4864 that allows you to set the number of seconds before GDB gives up trying
4865 to read from the target. The default value is 2.
4867 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4869 By default GDB will automatically keep track of objects as they are
4870 loaded and unloaded by the dynamic linker. By using the command `set
4871 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4872 when shared library events occur, thus allowing you to set breakpoints
4873 in shared libraries which are explicitly loaded by the inferior.
4875 Note this feature does not work on hpux8. On hpux9 you must link
4876 /usr/lib/end.o into your program. This feature should work
4877 automatically on hpux10.
4879 * Irix 5.x hardware watchpoint support
4881 Irix 5 configurations now support the use of hardware watchpoints.
4883 * Mips protocol "SYN garbage limit"
4885 When debugging a Mips target using the `target mips' protocol, you
4886 may set the number of characters that GDB will ignore by setting
4887 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4888 every character. The default value is 1050.
4890 * Recording and replaying remote debug sessions
4892 If you set `remotelogfile' to the name of a file, gdb will write to it
4893 a recording of a remote debug session. This recording may then be
4894 replayed back to gdb using "gdbreplay". See gdbserver/README for
4895 details. This is useful when you have a problem with GDB while doing
4896 remote debugging; you can make a recording of the session and send it
4897 to someone else, who can then recreate the problem.
4899 * Speedups for remote debugging
4901 GDB includes speedups for downloading and stepping MIPS systems using
4902 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4903 and more efficient S-record downloading.
4905 * Memory use reductions and statistics collection
4907 GDB now uses less memory and reports statistics about memory usage.
4908 Try the `maint print statistics' command, for example.
4910 *** Changes in GDB-4.15:
4912 * Psymtabs for XCOFF
4914 The symbol reader for AIX GDB now uses partial symbol tables. This
4915 can greatly improve startup time, especially for large executables.
4917 * Remote targets use caching
4919 Remote targets now use a data cache to speed up communication with the
4920 remote side. The data cache could lead to incorrect results because
4921 it doesn't know about volatile variables, thus making it impossible to
4922 debug targets which use memory mapped I/O devices. `set remotecache
4923 off' turns the the data cache off.
4925 * Remote targets may have threads
4927 The standard remote protocol now includes support for multiple threads
4928 in the target system, using new protocol commands 'H' and 'T'. See
4929 gdb/remote.c for details.
4933 If GDB is configured with `--enable-netrom', then it will include
4934 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4935 acts as though it is a bank of ROM on the target board, but you can
4936 write into it over the network. GDB's support consists only of
4937 support for fast loading into the emulated ROM; to debug, you must use
4938 another protocol, such as standard remote protocol. The usual
4939 sequence is something like
4941 target nrom <netrom-hostname>
4943 target remote <netrom-hostname>:1235
4947 GDB now includes support for the Apple Macintosh, as a host only. It
4948 may be run as either an MPW tool or as a standalone application, and
4949 it can debug through the serial port. All the usual GDB commands are
4950 available, but to the target command, you must supply "serial" as the
4951 device type instead of "/dev/ttyXX". See mpw-README in the main
4952 directory for more information on how to build. The MPW configuration
4953 scripts */mpw-config.in support only a few targets, and only the
4954 mips-idt-ecoff target has been tested.
4958 GDB configuration now uses autoconf. This is not user-visible,
4959 but does simplify configuration and building.
4963 GDB now supports hpux10.
4965 *** Changes in GDB-4.14:
4967 * New native configurations
4969 x86 FreeBSD i[345]86-*-freebsd
4970 x86 NetBSD i[345]86-*-netbsd
4971 NS32k NetBSD ns32k-*-netbsd
4972 Sparc NetBSD sparc-*-netbsd
4976 A29K VxWorks a29k-*-vxworks
4977 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4978 CPU32 EST-300 emulator m68*-*-est*
4979 PowerPC ELF powerpc-*-elf
4982 * Alpha OSF/1 support for procfs
4984 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4985 possible to attach to running processes. As the mounting of the /proc
4986 filesystem is optional on the Alpha, GDB automatically determines
4987 the availability of /proc during startup. This can lead to problems
4988 if /proc is unmounted after GDB has been started.
4990 * Arguments to user-defined commands
4992 User commands may accept up to 10 arguments separated by whitespace.
4993 Arguments are accessed within the user command via $arg0..$arg9. A
4996 print $arg0 + $arg1 + $arg2
4998 To execute the command use:
5001 Defines the command "adder" which prints the sum of its three arguments.
5002 Note the arguments are text substitutions, so they may reference variables,
5003 use complex expressions, or even perform inferior function calls.
5005 * New `if' and `while' commands
5007 This makes it possible to write more sophisticated user-defined
5008 commands. Both commands take a single argument, which is the
5009 expression to evaluate, and must be followed by the commands to
5010 execute, one per line, if the expression is nonzero, the list being
5011 terminated by the word `end'. The `if' command list may include an
5012 `else' word, which causes the following commands to be executed only
5013 if the expression is zero.
5015 * Fortran source language mode
5017 GDB now includes partial support for Fortran 77. It will recognize
5018 Fortran programs and can evaluate a subset of Fortran expressions, but
5019 variables and functions may not be handled correctly. GDB will work
5020 with G77, but does not yet know much about symbols emitted by other
5023 * Better HPUX support
5025 Most debugging facilities now work on dynamic executables for HPPAs
5026 running hpux9 or later. You can attach to running dynamically linked
5027 processes, but by default the dynamic libraries will be read-only, so
5028 for instance you won't be able to put breakpoints in them. To change
5029 that behavior do the following before running the program:
5035 This will cause the libraries to be mapped private and read-write.
5036 To revert to the normal behavior, do this:
5042 You cannot set breakpoints or examine data in the library until after
5043 the library is loaded if the function/data symbols do not have
5046 GDB can now also read debug symbols produced by the HP C compiler on
5047 HPPAs (sorry, no C++, Fortran or 68k support).
5049 * Target byte order now dynamically selectable
5051 You can choose which byte order to use with a target system, via the
5052 commands "set endian big" and "set endian little", and you can see the
5053 current setting by using "show endian". You can also give the command
5054 "set endian auto", in which case GDB will use the byte order
5055 associated with the executable. Currently, only embedded MIPS
5056 configurations support dynamic selection of target byte order.
5058 * New DOS host serial code
5060 This version uses DPMI interrupts to handle buffered I/O, so you
5061 no longer need to run asynctsr when debugging boards connected to
5064 *** Changes in GDB-4.13:
5066 * New "complete" command
5068 This lists all the possible completions for the rest of the line, if it
5069 were to be given as a command itself. This is intended for use by emacs.
5071 * Trailing space optional in prompt
5073 "set prompt" no longer adds a space for you after the prompt you set. This
5074 allows you to set a prompt which ends in a space or one that does not.
5076 * Breakpoint hit counts
5078 "info break" now displays a count of the number of times the breakpoint
5079 has been hit. This is especially useful in conjunction with "ignore"; you
5080 can ignore a large number of breakpoint hits, look at the breakpoint info
5081 to see how many times the breakpoint was hit, then run again, ignoring one
5082 less than that number, and this will get you quickly to the last hit of
5085 * Ability to stop printing at NULL character
5087 "set print null-stop" will cause GDB to stop printing the characters of
5088 an array when the first NULL is encountered. This is useful when large
5089 arrays actually contain only short strings.
5091 * Shared library breakpoints
5093 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5094 breakpoints in shared libraries before the executable is run.
5096 * Hardware watchpoints
5098 There is a new hardware breakpoint for the watch command for sparclite
5099 targets. See gdb/sparclite/hw_breakpoint.note.
5101 Hardware watchpoints are also now supported under GNU/Linux.
5105 Annotations have been added. These are for use with graphical interfaces,
5106 and are still experimental. Currently only gdba.el uses these.
5108 * Improved Irix 5 support
5110 GDB now works properly with Irix 5.2.
5112 * Improved HPPA support
5114 GDB now works properly with the latest GCC and GAS.
5116 * New native configurations
5118 Sequent PTX4 i[34]86-sequent-ptx4
5119 HPPA running OSF/1 hppa*-*-osf*
5120 Atari TT running SVR4 m68*-*-sysv4*
5121 RS/6000 LynxOS rs6000-*-lynxos*
5125 OS/9000 i[34]86-*-os9k
5126 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5129 * Hitachi SH7000 and E7000-PC ICE support
5131 There is now support for communicating with the Hitachi E7000-PC ICE.
5132 This is available automatically when GDB is configured for the SH.
5136 As usual, a variety of small fixes and improvements, both generic
5137 and configuration-specific. See the ChangeLog for more detail.
5139 *** Changes in GDB-4.12:
5141 * Irix 5 is now supported
5145 GDB-4.12 on the HPPA has a number of changes which make it unable
5146 to debug the output from the currently released versions of GCC and
5147 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5148 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5149 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5152 *** Changes in GDB-4.11:
5154 * User visible changes:
5158 The "set remotedebug" option is now consistent between the mips remote
5159 target, remote targets using the gdb-specific protocol, UDI (AMD's
5160 debug protocol for the 29k) and the 88k bug monitor. It is now an
5161 integer specifying a debug level (normally 0 or 1, but 2 means more
5162 debugging info for the mips target).
5164 * DEC Alpha native support
5166 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5167 debug info, but GDB works fairly well with the DEC compiler and should
5168 work with a future GCC release. See the README file for a few
5169 Alpha-specific notes.
5171 * Preliminary thread implementation
5173 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5175 * LynxOS native and target support for 386
5177 This release has been hosted on LynxOS 2.2, and also can be configured
5178 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5181 * Improvements in C++ mangling/demangling.
5183 This release has much better g++ debugging, specifically in name
5184 mangling/demangling, virtual function calls, print virtual table,
5185 call methods, ...etc.
5187 *** Changes in GDB-4.10:
5189 * User visible changes:
5191 Remote debugging using the GDB-specific (`target remote') protocol now
5192 supports the `load' command. This is only useful if you have some
5193 other way of getting the stub to the target system, and you can put it
5194 somewhere in memory where it won't get clobbered by the download.
5196 Filename completion now works.
5198 When run under emacs mode, the "info line" command now causes the
5199 arrow to point to the line specified. Also, "info line" prints
5200 addresses in symbolic form (as well as hex).
5202 All vxworks based targets now support a user settable option, called
5203 vxworks-timeout. This option represents the number of seconds gdb
5204 should wait for responses to rpc's. You might want to use this if
5205 your vxworks target is, perhaps, a slow software simulator or happens
5206 to be on the far side of a thin network line.
5210 This release contains support for using a DEC alpha as a GDB host for
5211 cross debugging. Native alpha debugging is not supported yet.
5214 *** Changes in GDB-4.9:
5218 This is the first GDB release which is accompanied by a matching testsuite.
5219 The testsuite requires installation of dejagnu, which should be available
5220 via ftp from most sites that carry GNU software.
5224 'Cfront' style demangling has had its name changed to 'ARM' style, to
5225 emphasize that it was written from the specifications in the C++ Annotated
5226 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5227 disclaimers, it still generated too much confusion with users attempting to
5228 use gdb with AT&T cfront.
5232 GDB now uses a standard remote interface to a simulator library.
5233 So far, the library contains simulators for the Zilog Z8001/2, the
5234 Hitachi H8/300, H8/500 and Super-H.
5236 * New targets supported
5238 H8/300 simulator h8300-hitachi-hms or h8300hms
5239 H8/500 simulator h8500-hitachi-hms or h8500hms
5240 SH simulator sh-hitachi-hms or sh
5241 Z8000 simulator z8k-zilog-none or z8ksim
5242 IDT MIPS board over serial line mips-idt-ecoff
5244 Cross-debugging to GO32 targets is supported. It requires a custom
5245 version of the i386-stub.c module which is integrated with the
5246 GO32 memory extender.
5248 * New remote protocols
5250 MIPS remote debugging protocol.
5252 * New source languages supported
5254 This version includes preliminary support for Chill, a Pascal like language
5255 used by telecommunications companies. Chill support is also being integrated
5256 into the GNU compiler, but we don't know when it will be publically available.
5259 *** Changes in GDB-4.8:
5261 * HP Precision Architecture supported
5263 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5264 version of this support was available as a set of patches from the
5265 University of Utah. GDB does not support debugging of programs
5266 compiled with the HP compiler, because HP will not document their file
5267 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5268 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5270 Many problems in the preliminary version have been fixed.
5272 * Faster and better demangling
5274 We have improved template demangling and fixed numerous bugs in the GNU style
5275 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5276 character types (wchar_t) are now supported. Demangling of each symbol is now
5277 only done once, and is cached when the symbol table for a file is read in.
5278 This results in a small increase in memory usage for C programs, a moderate
5279 increase in memory usage for C++ programs, and a fantastic speedup in
5282 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5283 from the specifications in the Annotated Reference Manual, which AT&T's
5284 compiler does not actually implement.
5286 * G++ multiple inheritance compiler problem
5288 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5289 inheritance lattices was reworked to properly discover ambiguities. We
5290 recently found an example which causes this new algorithm to fail in a
5291 very subtle way, producing bad debug information for those classes.
5292 The file 'gcc.patch' (in this directory) can be applied to gcc to
5293 circumvent the problem. A future GCC release will contain a complete
5296 The previous G++ debug info problem (mentioned below for the gdb-4.7
5297 release) is fixed in gcc version 2.3.2.
5299 * Improved configure script
5301 The `configure' script will now attempt to guess your system type if
5302 you don't supply a host system type. The old scheme of supplying a
5303 host system triplet is preferable over using this. All the magic is
5304 done in the new `config.guess' script. Examine it for details.
5306 We have also brought our configure script much more in line with the FSF's
5307 version. It now supports the --with-xxx options. In particular,
5308 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5309 The resulting GDB will not be able to read arbitrary object file formats --
5310 only the format ``expected'' to be used on the configured target system.
5311 We hope to make this the default in a future release.
5313 * Documentation improvements
5315 There's new internal documentation on how to modify GDB, and how to
5316 produce clean changes to the code. We implore people to read it
5317 before submitting changes.
5319 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5320 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5321 `info' files are also provided. To build `info' files from scratch,
5322 you will need the latest `makeinfo' release, which will be available in
5323 a future texinfo-X.Y release.
5325 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5326 We're not sure exactly which versions have this problem, but it has
5327 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5328 or better. If that isn't possible, there is a patch in
5329 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5330 around this problem.
5334 GDB now supports array constants that can be used in expressions typed in by
5335 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5336 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5339 The new directory `gdb/sparclite' contains a program that demonstrates
5340 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5342 * New native hosts supported
5344 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5345 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5347 * New targets supported
5349 AMD 29k family via UDI a29k-amd-udi or udi29k
5351 * New file formats supported
5353 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5354 HPUX core files, and SCO 3.2v2 core files.
5358 Attaching to processes now works again; thanks for the many bug reports.
5360 We have also stomped on a bunch of core dumps caused by
5361 printf_filtered("%s") problems.
5363 We eliminated a copyright problem on the rpc and ptrace header files
5364 for VxWorks, which was discovered at the last minute during the 4.7
5365 release. You should now be able to build a VxWorks GDB.
5367 You can now interrupt gdb while an attached process is running. This
5368 will cause the attached process to stop, and give control back to GDB.
5370 We fixed problems caused by using too many file descriptors
5371 for reading symbols from object files and libraries. This was
5372 especially a problem for programs that used many (~100) shared
5375 The `step' command now only enters a subroutine if there is line number
5376 information for the subroutine. Otherwise it acts like the `next'
5377 command. Previously, `step' would enter subroutines if there was
5378 any debugging information about the routine. This avoids problems
5379 when using `cc -g1' on MIPS machines.
5381 * Internal improvements
5383 GDB's internal interfaces have been improved to make it easier to support
5384 debugging of multiple languages in the future.
5386 GDB now uses a common structure for symbol information internally.
5387 Minimal symbols (derived from linkage symbols in object files), partial
5388 symbols (from a quick scan of debug information), and full symbols
5389 contain a common subset of information, making it easier to write
5390 shared code that handles any of them.
5392 * New command line options
5394 We now accept --silent as an alias for --quiet.
5398 The memory-mapped-malloc library is now licensed under the GNU Library
5399 General Public License.
5401 *** Changes in GDB-4.7:
5403 * Host/native/target split
5405 GDB has had some major internal surgery to untangle the support for
5406 hosts and remote targets. Now, when you configure GDB for a remote
5407 target, it will no longer load in all of the support for debugging
5408 local programs on the host. When fully completed and tested, this will
5409 ensure that arbitrary host/target combinations are possible.
5411 The primary conceptual shift is to separate the non-portable code in
5412 GDB into three categories. Host specific code is required any time GDB
5413 is compiled on that host, regardless of the target. Target specific
5414 code relates to the peculiarities of the target, but can be compiled on
5415 any host. Native specific code is everything else: it can only be
5416 built when the host and target are the same system. Child process
5417 handling and core file support are two common `native' examples.
5419 GDB's use of /proc for controlling Unix child processes is now cleaner.
5420 It has been split out into a single module under the `target_ops' vector,
5421 plus two native-dependent functions for each system that uses /proc.
5423 * New hosts supported
5425 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5426 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5427 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5429 * New targets supported
5431 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5432 68030 and CPU32 m68030-*-*, m68332-*-*
5434 * New native hosts supported
5436 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5437 (386bsd is not well tested yet)
5438 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5440 * New file formats supported
5442 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5443 supports reading of `a.out.adobe' object files, which are an a.out
5444 format extended with minimal information about multiple sections.
5448 `show copying' is the same as the old `info copying'.
5449 `show warranty' is the same as `info warrantee'.
5450 These were renamed for consistency. The old commands continue to work.
5452 `info handle' is a new alias for `info signals'.
5454 You can now define pre-command hooks, which attach arbitrary command
5455 scripts to any command. The commands in the hook will be executed
5456 prior to the user's command. You can also create a hook which will be
5457 executed whenever the program stops. See gdb.texinfo.
5461 We now deal with Cfront style name mangling, and can even extract type
5462 info from mangled symbols. GDB can automatically figure out which
5463 symbol mangling style your C++ compiler uses.
5465 Calling of methods and virtual functions has been improved as well.
5469 The crash that occured when debugging Sun Ansi-C compiled binaries is
5470 fixed. This was due to mishandling of the extra N_SO stabs output
5473 We also finally got Ultrix 4.2 running in house, and fixed core file
5474 support, with help from a dozen people on the net.
5476 John M. Farrell discovered that the reason that single-stepping was so
5477 slow on all of the Mips based platforms (primarily SGI and DEC) was
5478 that we were trying to demangle and lookup a symbol used for internal
5479 purposes on every instruction that was being stepped through. Changing
5480 the name of that symbol so that it couldn't be mistaken for a C++
5481 mangled symbol sped things up a great deal.
5483 Rich Pixley sped up symbol lookups in general by getting much smarter
5484 about when C++ symbol mangling is necessary. This should make symbol
5485 completion (TAB on the command line) much faster. It's not as fast as
5486 we'd like, but it's significantly faster than gdb-4.6.
5490 A new user controllable variable 'call_scratch_address' can
5491 specify the location of a scratch area to be used when GDB
5492 calls a function in the target. This is necessary because the
5493 usual method of putting the scratch area on the stack does not work
5494 in systems that have separate instruction and data spaces.
5496 We integrated changes to support the 29k UDI (Universal Debugger
5497 Interface), but discovered at the last minute that we didn't have all
5498 of the appropriate copyright paperwork. We are working with AMD to
5499 resolve this, and hope to have it available soon.
5503 We have sped up the remote serial line protocol, especially for targets
5504 with lots of registers. It now supports a new `expedited status' ('T')
5505 message which can be used in place of the existing 'S' status message.
5506 This allows the remote stub to send only the registers that GDB
5507 needs to make a quick decision about single-stepping or conditional
5508 breakpoints, eliminating the need to fetch the entire register set for
5509 each instruction being stepped through.
5511 The GDB remote serial protocol now implements a write-through cache for
5512 registers, only re-reading the registers if the target has run.
5514 There is also a new remote serial stub for SPARC processors. You can
5515 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5516 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5517 processor with a serial port.
5521 Configure.in files have become much easier to read and modify. A new
5522 `table driven' format makes it more obvious what configurations are
5523 supported, and what files each one uses.
5527 There is a new opcodes library which will eventually contain all of the
5528 disassembly routines and opcode tables. At present, it only contains
5529 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5530 disassembler (binutils/objdump) to share these routines.
5532 The libiberty library is now copylefted under the GNU Library General
5533 Public License. This allows more liberal use, and was done so libg++
5534 can use it. This makes no difference to GDB, since the Library License
5535 grants all the rights from the General Public License.
5539 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5540 reference to the stabs symbol info used by the debugger. It is (as far
5541 as we know) the only published document on this fascinating topic. We
5542 encourage you to read it, compare it to the stabs information on your
5543 system, and send improvements on the document in general (to
5544 bug-gdb@prep.ai.mit.edu).
5546 And, of course, many bugs have been fixed.
5549 *** Changes in GDB-4.6:
5551 * Better support for C++ function names
5553 GDB now accepts as input the "demangled form" of C++ overloaded function
5554 names and member function names, and can do command completion on such names
5555 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5556 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5557 Make use of command completion, it is your friend.
5559 GDB also now accepts a variety of C++ mangled symbol formats. They are
5560 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5561 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5562 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5563 for the list of formats.
5565 * G++ symbol mangling problem
5567 Recent versions of gcc have a bug in how they emit debugging information for
5568 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5569 directory) can be applied to gcc to fix the problem. Alternatively, if you
5570 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5571 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5572 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5575 * New 'maintenance' command
5577 All of the commands related to hacking GDB internals have been moved out of
5578 the main command set, and now live behind the 'maintenance' command. This
5579 can also be abbreviated as 'mt'. The following changes were made:
5581 dump-me -> maintenance dump-me
5582 info all-breakpoints -> maintenance info breakpoints
5583 printmsyms -> maintenance print msyms
5584 printobjfiles -> maintenance print objfiles
5585 printpsyms -> maintenance print psymbols
5586 printsyms -> maintenance print symbols
5588 The following commands are new:
5590 maintenance demangle Call internal GDB demangler routine to
5591 demangle a C++ link name and prints the result.
5592 maintenance print type Print a type chain for a given symbol
5594 * Change to .gdbinit file processing
5596 We now read the $HOME/.gdbinit file before processing the argv arguments
5597 (e.g. reading symbol files or core files). This allows global parameters to
5598 be set, which will apply during the symbol reading. The ./.gdbinit is still
5599 read after argv processing.
5601 * New hosts supported
5603 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5605 GNU/Linux support i386-unknown-linux or linux
5607 We are also including code to support the HP/PA running BSD and HPUX. This
5608 is almost guaranteed not to work, as we didn't have time to test or build it
5609 for this release. We are including it so that the more adventurous (or
5610 masochistic) of you can play with it. We also had major problems with the
5611 fact that the compiler that we got from HP doesn't support the -g option.
5614 * New targets supported
5616 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5618 * More smarts about finding #include files
5620 GDB now remembers the compilation directory for all include files, and for
5621 all files from which C is generated (like yacc and lex sources). This
5622 greatly improves GDB's ability to find yacc/lex sources, and include files,
5623 especially if you are debugging your program from a directory different from
5624 the one that contains your sources.
5626 We also fixed a bug which caused difficulty with listing and setting
5627 breakpoints in include files which contain C code. (In the past, you had to
5628 try twice in order to list an include file that you hadn't looked at before.)
5630 * Interesting infernals change
5632 GDB now deals with arbitrary numbers of sections, where the symbols for each
5633 section must be relocated relative to that section's landing place in the
5634 target's address space. This work was needed to support ELF with embedded
5635 stabs used by Solaris-2.0.
5637 * Bug fixes (of course!)
5639 There have been loads of fixes for the following things:
5640 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5641 i960, stabs, DOS(GO32), procfs, etc...
5643 See the ChangeLog for details.
5645 *** Changes in GDB-4.5:
5647 * New machines supported (host and target)
5649 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5651 SGI Irix-4.x mips-sgi-irix4 or iris4
5653 * New malloc package
5655 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5656 Mmalloc is capable of handling mutiple heaps of memory. It is also
5657 capable of saving a heap to a file, and then mapping it back in later.
5658 This can be used to greatly speedup the startup of GDB by using a
5659 pre-parsed symbol table which lives in a mmalloc managed heap. For
5660 more details, please read mmalloc/mmalloc.texi.
5664 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5665 'help info proc' for details.
5667 * MIPS ecoff symbol table format
5669 The code that reads MIPS symbol table format is now supported on all hosts.
5670 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5673 * File name changes for MS-DOS
5675 Many files in the config directories have been renamed to make it easier to
5676 support GDB on MS-DOSe systems (which have very restrictive file name
5677 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5678 environment) is close to working but has some remaining problems. Note
5679 that debugging of DOS programs is not supported, due to limitations
5680 in the ``operating system'', but it can be used to host cross-debugging.
5682 * Cross byte order fixes
5684 Many fixes have been made to support cross debugging of Sparc and MIPS
5685 targets from hosts whose byte order differs.
5687 * New -mapped and -readnow options
5689 If memory-mapped files are available on your system through the 'mmap'
5690 system call, you can use the -mapped option on the `file' or
5691 `symbol-file' commands to cause GDB to write the symbols from your
5692 program into a reusable file. If the program you are debugging is
5693 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5694 Future GDB debugging sessions will notice the presence of this file,
5695 and will quickly map in symbol information from it, rather than reading
5696 the symbol table from the executable program. Using the '-mapped'
5697 option in a GDB `file' or `symbol-file' command has the same effect as
5698 starting GDB with the '-mapped' command-line option.
5700 You can cause GDB to read the entire symbol table immediately by using
5701 the '-readnow' option with any of the commands that load symbol table
5702 information (or on the GDB command line). This makes the command
5703 slower, but makes future operations faster.
5705 The -mapped and -readnow options are typically combined in order to
5706 build a `fred.syms' file that contains complete symbol information.
5707 A simple GDB invocation to do nothing but build a `.syms' file for future
5710 gdb -batch -nx -mapped -readnow programname
5712 The `.syms' file is specific to the host machine on which GDB is run.
5713 It holds an exact image of GDB's internal symbol table. It cannot be
5714 shared across multiple host platforms.
5716 * longjmp() handling
5718 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5719 siglongjmp() without losing control. This feature has not yet been ported to
5720 all systems. It currently works on many 386 platforms, all MIPS-based
5721 platforms (SGI, DECstation, etc), and Sun3/4.
5725 Preliminary work has been put in to support the new Solaris OS from Sun. At
5726 this time, it can control and debug processes, but it is not capable of
5731 As always, many many bug fixes. The major areas were with g++, and mipsread.
5732 People using the MIPS-based platforms should experience fewer mysterious
5733 crashes and trashed symbol tables.
5735 *** Changes in GDB-4.4:
5737 * New machines supported (host and target)
5739 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5741 BSD Reno on Vax vax-dec-bsd
5742 Ultrix on Vax vax-dec-ultrix
5744 * New machines supported (target)
5746 AMD 29000 embedded, using EBMON a29k-none-none
5750 GDB continues to improve its handling of C++. `References' work better.
5751 The demangler has also been improved, and now deals with symbols mangled as
5752 per the Annotated C++ Reference Guide.
5754 GDB also now handles `stabs' symbol information embedded in MIPS
5755 `ecoff' symbol tables. Since the ecoff format was not easily
5756 extensible to handle new languages such as C++, this appeared to be a
5757 good way to put C++ debugging info into MIPS binaries. This option
5758 will be supported in the GNU C compiler, version 2, when it is
5761 * New features for SVR4
5763 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5764 shared libraries. Debugging dynamically linked programs should present
5765 only minor differences from debugging statically linked programs.
5767 The `info proc' command will print out information about any process
5768 on an SVR4 system (including the one you are debugging). At the moment,
5769 it prints the address mappings of the process.
5771 If you bring up GDB on another SVR4 system, please send mail to
5772 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5774 * Better dynamic linking support in SunOS
5776 Reading symbols from shared libraries which contain debugging symbols
5777 now works properly. However, there remain issues such as automatic
5778 skipping of `transfer vector' code during function calls, which
5779 make it harder to debug code in a shared library, than to debug the
5780 same code linked statically.
5784 GDB is now using the latest `getopt' routines from the FSF. This
5785 version accepts the -- prefix for options with long names. GDB will
5786 continue to accept the old forms (-option and +option) as well.
5787 Various single letter abbreviations for options have been explicity
5788 added to the option table so that they won't get overshadowed in the
5789 future by other options that begin with the same letter.
5793 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5794 Many assorted bugs have been handled. Many more remain to be handled.
5795 See the various ChangeLog files (primarily in gdb and bfd) for details.
5798 *** Changes in GDB-4.3:
5800 * New machines supported (host and target)
5802 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5803 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5804 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5806 * Almost SCO Unix support
5808 We had hoped to support:
5809 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5810 (except for core file support), but we discovered very late in the release
5811 that it has problems with process groups that render gdb unusable. Sorry
5812 about that. I encourage people to fix it and post the fixes.
5814 * Preliminary ELF and DWARF support
5816 GDB can read ELF object files on System V Release 4, and can handle
5817 debugging records for C, in DWARF format, in ELF files. This support
5818 is preliminary. If you bring up GDB on another SVR4 system, please
5819 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5824 GDB now uses the latest `readline' library. One user-visible change
5825 is that two tabs will list possible command completions, which previously
5826 required typing M-? (meta-question mark, or ESC ?).
5830 The `stepi' bug that many of you noticed has been squashed.
5831 Many bugs in C++ have been handled. Many more remain to be handled.
5832 See the various ChangeLog files (primarily in gdb and bfd) for details.
5834 * State of the MIPS world (in case you wondered):
5836 GDB can understand the symbol tables emitted by the compilers
5837 supplied by most vendors of MIPS-based machines, including DEC. These
5838 symbol tables are in a format that essentially nobody else uses.
5840 Some versions of gcc come with an assembler post-processor called
5841 mips-tfile. This program is required if you want to do source-level
5842 debugging of gcc-compiled programs. I believe FSF does not ship
5843 mips-tfile with gcc version 1, but it will eventually come with gcc
5846 Debugging of g++ output remains a problem. g++ version 1.xx does not
5847 really support it at all. (If you're lucky, you should be able to get
5848 line numbers and stack traces to work, but no parameters or local
5849 variables.) With some work it should be possible to improve the
5852 When gcc version 2 is released, you will have somewhat better luck.
5853 However, even then you will get confusing results for inheritance and
5856 We will eventually provide full debugging of g++ output on
5857 DECstations. This will probably involve some kind of stabs-in-ecoff
5858 encapulation, but the details have not been worked out yet.
5861 *** Changes in GDB-4.2:
5863 * Improved configuration
5865 Only one copy of `configure' exists now, and it is not self-modifying.
5866 Porting BFD is simpler.
5870 The `step' and `next' commands now only stop at the first instruction
5871 of a source line. This prevents the multiple stops that used to occur
5872 in switch statements, for-loops, etc. `Step' continues to stop if a
5873 function that has debugging information is called within the line.
5877 Lots of small bugs fixed. More remain.
5879 * New host supported (not target)
5881 Intel 386 PC clone running Mach i386-none-mach
5884 *** Changes in GDB-4.1:
5886 * Multiple source language support
5888 GDB now has internal scaffolding to handle several source languages.
5889 It determines the type of each source file from its filename extension,
5890 and will switch expression parsing and number formatting to match the
5891 language of the function in the currently selected stack frame.
5892 You can also specifically set the language to be used, with
5893 `set language c' or `set language modula-2'.
5897 GDB now has preliminary support for the GNU Modula-2 compiler,
5898 currently under development at the State University of New York at
5899 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5900 continue through the fall of 1991 and into 1992.
5902 Other Modula-2 compilers are currently not supported, and attempting to
5903 debug programs compiled with them will likely result in an error as the
5904 symbol table is read. Feel free to work on it, though!
5906 There are hooks in GDB for strict type checking and range checking,
5907 in the `Modula-2 philosophy', but they do not currently work.
5911 GDB can now write to executable and core files (e.g. patch
5912 a variable's value). You must turn this switch on, specify
5913 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5914 by assigning a new value to a variable. Modifications take
5917 * Automatic SunOS shared library reading
5919 When you run your program, GDB automatically determines where its
5920 shared libraries (if any) have been loaded, and reads their symbols.
5921 The `share' command is no longer needed. This also works when
5922 examining core files.
5926 You can specify the number of lines that the `list' command shows.
5929 * New machines supported (host and target)
5931 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5932 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5933 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5935 * New hosts supported (not targets)
5937 IBM RT/PC: romp-ibm-aix or rtpc
5939 * New targets supported (not hosts)
5941 AMD 29000 embedded with COFF a29k-none-coff
5942 AMD 29000 embedded with a.out a29k-none-aout
5943 Ultracomputer remote kernel debug a29k-nyu-kern
5945 * New remote interfaces
5951 *** Changes in GDB-4.0:
5955 Wide output is wrapped at good places to make the output more readable.
5957 Gdb now supports cross-debugging from a host machine of one type to a
5958 target machine of another type. Communication with the target system
5959 is over serial lines. The ``target'' command handles connecting to the
5960 remote system; the ``load'' command will download a program into the
5961 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5962 also supports debugging of realtime processes running under VxWorks,
5963 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5964 stub on the target system.
5966 New CPUs supported include the AMD 29000 and Intel 960.
5968 GDB now reads object files and symbol tables via a ``binary file''
5969 library, which allows a single copy of GDB to debug programs of multiple
5970 object file types such as a.out and coff.
5972 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5973 refcard.dvi and refcard.ps are available to format it).
5976 * Control-Variable user interface simplified
5978 All variables that control the operation of the debugger can be set
5979 by the ``set'' command, and displayed by the ``show'' command.
5981 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5982 ``Show prompt'' produces the response:
5983 Gdb's prompt is new-gdb=>.
5985 What follows are the NEW set commands. The command ``help set'' will
5986 print a complete list of old and new set commands. ``help set FOO''
5987 will give a longer description of the variable FOO. ``show'' will show
5988 all of the variable descriptions and their current settings.
5990 confirm on/off: Enables warning questions for operations that are
5991 hard to recover from, e.g. rerunning the program while
5992 it is already running. Default is ON.
5994 editing on/off: Enables EMACS style command line editing
5995 of input. Previous lines can be recalled with
5996 control-P, the current line can be edited with control-B,
5997 you can search for commands with control-R, etc.
6000 history filename NAME: NAME is where the gdb command history
6001 will be stored. The default is .gdb_history,
6002 or the value of the environment variable
6005 history size N: The size, in commands, of the command history. The
6006 default is 256, or the value of the environment variable
6009 history save on/off: If this value is set to ON, the history file will
6010 be saved after exiting gdb. If set to OFF, the
6011 file will not be saved. The default is OFF.
6013 history expansion on/off: If this value is set to ON, then csh-like
6014 history expansion will be performed on
6015 command line input. The default is OFF.
6017 radix N: Sets the default radix for input and output. It can be set
6018 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6019 in the current radix, so "set radix 10" is always a no-op.
6021 height N: This integer value is the number of lines on a page. Default
6022 is 24, the current `stty rows'' setting, or the ``li#''
6023 setting from the termcap entry matching the environment
6026 width N: This integer value is the number of characters on a line.
6027 Default is 80, the current `stty cols'' setting, or the ``co#''
6028 setting from the termcap entry matching the environment
6031 Note: ``set screensize'' is obsolete. Use ``set height'' and
6032 ``set width'' instead.
6034 print address on/off: Print memory addresses in various command displays,
6035 such as stack traces and structure values. Gdb looks
6036 more ``symbolic'' if you turn this off; it looks more
6037 ``machine level'' with it on. Default is ON.
6039 print array on/off: Prettyprint arrays. New convenient format! Default
6042 print demangle on/off: Print C++ symbols in "source" form if on,
6045 print asm-demangle on/off: Same, for assembler level printouts
6048 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6051 * Support for Epoch Environment.
6053 The epoch environment is a version of Emacs v18 with windowing. One
6054 new command, ``inspect'', is identical to ``print'', except that if you
6055 are running in the epoch environment, the value is printed in its own
6059 * Support for Shared Libraries
6061 GDB can now debug programs and core files that use SunOS shared libraries.
6062 Symbols from a shared library cannot be referenced
6063 before the shared library has been linked with the program (this
6064 happens after you type ``run'' and before the function main() is entered).
6065 At any time after this linking (including when examining core files
6066 from dynamically linked programs), gdb reads the symbols from each
6067 shared library when you type the ``sharedlibrary'' command.
6068 It can be abbreviated ``share''.
6070 sharedlibrary REGEXP: Load shared object library symbols for files
6071 matching a unix regular expression. No argument
6072 indicates to load symbols for all shared libraries.
6074 info sharedlibrary: Status of loaded shared libraries.
6079 A watchpoint stops execution of a program whenever the value of an
6080 expression changes. Checking for this slows down execution
6081 tremendously whenever you are in the scope of the expression, but is
6082 quite useful for catching tough ``bit-spreader'' or pointer misuse
6083 problems. Some machines such as the 386 have hardware for doing this
6084 more quickly, and future versions of gdb will use this hardware.
6086 watch EXP: Set a watchpoint (breakpoint) for an expression.
6088 info watchpoints: Information about your watchpoints.
6090 delete N: Deletes watchpoint number N (same as breakpoints).
6091 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6092 enable N: Re-enables watchpoint number N (same as breakpoints).
6095 * C++ multiple inheritance
6097 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6100 * C++ exception handling
6102 Gdb now supports limited C++ exception handling. Besides the existing
6103 ability to breakpoint on an exception handler, gdb can breakpoint on
6104 the raising of an exception (before the stack is peeled back to the
6107 catch FOO: If there is a FOO exception handler in the dynamic scope,
6108 set a breakpoint to catch exceptions which may be raised there.
6109 Multiple exceptions (``catch foo bar baz'') may be caught.
6111 info catch: Lists all exceptions which may be caught in the
6112 current stack frame.
6115 * Minor command changes
6117 The command ``call func (arg, arg, ...)'' now acts like the print
6118 command, except it does not print or save a value if the function's result
6119 is void. This is similar to dbx usage.
6121 The ``up'' and ``down'' commands now always print the frame they end up
6122 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6123 frames without printing.
6125 * New directory command
6127 'dir' now adds directories to the FRONT of the source search path.
6128 The path starts off empty. Source files that contain debug information
6129 about the directory in which they were compiled can be found even
6130 with an empty path; Sun CC and GCC include this information. If GDB can't
6131 find your source file in the current directory, type "dir .".
6133 * Configuring GDB for compilation
6135 For normal use, type ``./configure host''. See README or gdb.texinfo
6138 GDB now handles cross debugging. If you are remotely debugging between
6139 two different machines, type ``./configure host -target=targ''.
6140 Host is the machine where GDB will run; targ is the machine
6141 where the program that you are debugging will run.