1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.9
6 * Support for process record-replay and reverse debugging on aarch64*-linux*
7 targets has been added. GDB now supports recording of A64 instruction set
8 including advance SIMD instructions.
10 * GDB now honors the content of the file /proc/PID/coredump_filter
11 (PID is the process ID) on GNU/Linux systems. This file can be used
12 to specify the types of memory mappings that will be included in a
13 corefile. For more information, please refer to the manual page of
14 "core(5)". GDB also has a new command: "set use-coredump-filter
15 on|off". It allows to set whether GDB will read the content of the
16 /proc/PID/coredump_filter file when generating a corefile.
18 * The "info os" command on GNU/Linux can now display information on
20 "info os cpus" Listing of all cpus/cores on the system
22 * GDB has two new commands: "set serial parity odd|even|none" and
23 "show serial parity". These allows to set or show parity for the
26 * The "info source" command now displays the producer string if it was
27 present in the debug info. This typically includes the compiler version
28 and may include things like its command line arguments.
30 * The "info dll", an alias of the "info sharedlibrary" command,
31 is now available on all platforms.
33 * Directory names supplied to the "set sysroot" commands may be
34 prefixed with "target:" to tell GDB to access shared libraries from
35 the target system, be it local or remote. This replaces the prefix
36 "remote:". The default sysroot has been changed from "" to
37 "target:". "remote:" is automatically converted to "target:" for
38 backward compatibility.
40 * The system root specified by "set sysroot" will be prepended to the
41 filename of the main executable (if reported to GDB as absolute by
42 the operating system) when starting processes remotely, and when
43 attaching to already-running local or remote processes.
45 * GDB now supports automatic location and retrieval of executable
46 files from remote targets. Remote debugging can now be initiated
47 using only a "target remote" or "target extended-remote" command
48 (no "set sysroot" or "file" commands are required). See "New remote
51 * The "dump" command now supports verilog hex format.
53 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
55 * On GNU/Linux, GDB and gdbserver are now able to access executable
56 and shared library files without a "set sysroot" command when
57 attaching to processes running in different mount namespaces from
58 the debugger. This makes it possible to attach to processes in
59 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
60 See "New remote packets" below.
62 * The "tui reg" command now provides completion for all of the
63 available register groups, including target specific groups.
65 * The HISTSIZE environment variable is no longer read when determining
66 the size of GDB's command history. GDB now instead reads the dedicated
67 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
68 disables truncation of command history. Non-numeric values of GDBHISTSIZE
73 ** Memory ports can now be unbuffered.
77 ** gdb.Objfile objects have a new attribute "username",
78 which is the name of the objfile as specified by the user,
79 without, for example, resolving symlinks.
80 ** You can now write frame unwinders in Python.
81 ** gdb.Type objects have a new method "optimized_out",
82 returning optimized out gdb.Value instance of this type.
83 ** gdb.Value objects have new methods "reference_value" and
84 "const_value" which return a reference to the value and a
85 "const" version of the value respectively.
89 maint print symbol-cache
90 Print the contents of the symbol cache.
92 maint print symbol-cache-statistics
93 Print statistics of symbol cache usage.
95 maint flush-symbol-cache
96 Flush the contents of the symbol cache.
100 Start branch trace recording using Branch Trace Store (BTS) format.
103 Evaluate expression by using the compiler and print result.
107 Explicit commands for enabling and disabling tui mode.
110 set mpx bound on i386 and amd64
111 Support for bound table investigation on Intel(R) MPX enabled applications.
116 Renamed from "set debug dwarf2-die".
118 Renamed from "show debug dwarf2-die".
121 Renamed from "set debug dwarf2-read".
122 show debug dwarf-read
123 Renamed from "show debug dwarf2-read".
125 maint set dwarf always-disassemble
126 Renamed from "maint set dwarf2 always-disassemble".
127 maint show dwarf always-disassemble
128 Renamed from "maint show dwarf2 always-disassemble".
130 maint set dwarf max-cache-age
131 Renamed from "maint set dwarf2 max-cache-age".
132 maint show dwarf max-cache-age
133 Renamed from "maint show dwarf2 max-cache-age".
136 show debug dwarf-line
137 Control display of debugging info regarding DWARF line processing.
141 Set the maximum number of candidates to be considered during
142 completion. The default value is 200. This limit allows GDB
143 to avoid generating large completion lists, the computation of
144 which can cause the debugger to become temporarily unresponsive.
146 maint set symbol-cache-size
147 maint show symbol-cache-size
148 Control the size of the symbol cache.
150 set|show record btrace bts buffer-size
151 Set and show the size of the ring buffer used for branch tracing in
153 The obtained size may differ from the requested size. Use "info
154 record" to see the obtained buffer size.
156 set debug linux-namespaces
157 show debug linux-namespaces
158 Control display of debugging info regarding Linux namespaces.
160 * The command 'thread apply all' can now support new option '-ascending'
161 to call its specified command for all threads in ascending order.
163 * Python/Guile scripting
165 ** GDB now supports auto-loading of Python/Guile scripts contained in the
166 special section named `.debug_gdb_scripts'.
170 qXfer:btrace-conf:read
171 Return the branch trace configuration for the current thread.
173 Qbtrace-conf:bts:size
174 Set the requested ring buffer size for branch tracing in BTS format.
177 Indicates a memory breakpoint instruction was executed, irrespective
178 of whether it was GDB that planted the breakpoint or the breakpoint
179 is hardcoded in the program. This is required for correct non-stop
183 Indicates the target stopped for a hardware breakpoint. This is
184 required for correct non-stop mode operation.
187 Return information about files on the remote system.
190 Return the full absolute name of the file that was executed to
191 create a process running on the remote system.
194 Select the filesystem on which vFile: operations with filename
195 arguments will operate. This is required for GDB to be able to
196 access files on remote targets where the remote stub does not
197 share a common filesystem with the inferior(s).
200 Indicates that a fork system call was executed.
203 Indicates that a vfork system call was executed.
205 vforkdone stop reason
206 Indicates that a vfork child of the specified process has executed
207 an exec or exit, allowing the vfork parent to resume execution.
209 fork-events and vfork-events features in qSupported
210 The qSupported packet allows GDB to request support for fork and
211 vfork events using new 'gdbfeatures' fork-events and vfork-events,
212 and the qSupported response can contain the corresponding
213 'stubfeatures'. Set and show commands can be used to display
214 whether these features are enabled.
216 * Extended-remote fork events
218 ** GDB now has support for fork events on extended-remote Linux
219 targets. For targets with Linux kernels 2.5.60 and later, this
220 enables follow-fork-mode and detach-on-fork for both fork and
221 vfork, as well as fork and vfork catchpoints.
223 * The info record command now shows the recording format and the
224 branch tracing configuration for the current thread when using
225 the btrace record target.
226 For the BTS format, it shows the ring buffer size.
228 * GDB now has support for DTrace USDT (Userland Static Defined
229 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
231 * GDB now supports access to vector registers on S/390 GNU/Linux
234 * Removed command line options
236 -xdb HP-UX XDB compatibility mode.
238 * Removed targets and native configurations
240 HP/PA running HP-UX hppa*-*-hpux*
241 Itanium running HP-UX ia64-*-hpux*
243 *** Changes in GDB 7.9.1
247 ** Xmethods can now specify a result type.
249 *** Changes in GDB 7.9
251 * GDB now supports hardware watchpoints on x86 GNU Hurd.
255 ** You can now access frame registers from Python scripts.
256 ** New attribute 'producer' for gdb.Symtab objects.
257 ** gdb.Objfile objects have a new attribute "progspace",
258 which is the gdb.Progspace object of the containing program space.
259 ** gdb.Objfile objects have a new attribute "owner".
260 ** gdb.Objfile objects have a new attribute "build_id",
261 which is the build ID generated when the file was built.
262 ** gdb.Objfile objects have a new method "add_separate_debug_file".
263 ** A new event "gdb.clear_objfiles" has been added, triggered when
264 selecting a new file to debug.
265 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
266 ** New function gdb.lookup_objfile.
268 New events which are triggered when GDB modifies the state of the
271 ** gdb.events.inferior_call_pre: Function call is about to be made.
272 ** gdb.events.inferior_call_post: Function call has just been made.
273 ** gdb.events.memory_changed: A memory location has been altered.
274 ** gdb.events.register_changed: A register has been altered.
276 * New Python-based convenience functions:
278 ** $_caller_is(name [, number_of_frames])
279 ** $_caller_matches(regexp [, number_of_frames])
280 ** $_any_caller_is(name [, number_of_frames])
281 ** $_any_caller_matches(regexp [, number_of_frames])
283 * GDB now supports the compilation and injection of source code into
284 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
285 to compile the source code to object code, and if successful, inject
286 and execute that code within the current context of the inferior.
287 Currently the C language is supported. The commands used to
288 interface with this new feature are:
290 compile code [-raw|-r] [--] [source code]
291 compile file [-raw|-r] filename
295 demangle [-l language] [--] name
296 Demangle "name" in the specified language, or the current language
297 if elided. This command is renamed from the "maint demangle" command.
298 The latter is kept as a no-op to avoid "maint demangle" being interpreted
299 as "maint demangler-warning".
301 queue-signal signal-name-or-number
302 Queue a signal to be delivered to the thread when it is resumed.
304 add-auto-load-scripts-directory directory
305 Add entries to the list of directories from which to load auto-loaded
308 maint print user-registers
309 List all currently available "user" registers.
311 compile code [-r|-raw] [--] [source code]
312 Compile, inject, and execute in the inferior the executable object
313 code produced by compiling the provided source code.
315 compile file [-r|-raw] filename
316 Compile and inject into the inferior the executable object code
317 produced by compiling the source code stored in the filename
320 * On resume, GDB now always passes the signal the program had stopped
321 for to the thread the signal was sent to, even if the user changed
322 threads before resuming. Previously GDB would often (but not
323 always) deliver the signal to the thread that happens to be current
326 * Conversely, the "signal" command now consistently delivers the
327 requested signal to the current thread. GDB now asks for
328 confirmation if the program had stopped for a signal and the user
329 switched threads meanwhile.
331 * "breakpoint always-inserted" modes "off" and "auto" merged.
333 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
334 won't remove breakpoints from the target until all threads stop,
335 even in non-stop mode. The "auto" mode has been removed, and "off"
336 is now the default mode.
340 set debug symbol-lookup
341 show debug symbol-lookup
342 Control display of debugging info regarding symbol lookup.
346 ** The -list-thread-groups command outputs an exit-code field for
347 inferiors that have exited.
351 MIPS SDE mips*-sde*-elf*
355 Support for these obsolete configurations has been removed.
357 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
358 SGI Irix-5.x mips-*-irix5*
359 SGI Irix-6.x mips-*-irix6*
360 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
361 VAX running Ultrix vax-*-ultrix*
363 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
364 and "assf"), have been removed. Use the "sharedlibrary" command, or
365 its alias "share", instead.
367 *** Changes in GDB 7.8
369 * New command line options
372 This is an alias for the --data-directory option.
374 * GDB supports printing and modifying of variable length automatic arrays
375 as specified in ISO C99.
377 * The ARM simulator now supports instruction level tracing
378 with or without disassembly.
382 GDB now has support for scripting using Guile. Whether this is
383 available is determined at configure time.
384 Guile version 2.0 or greater is required.
385 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
387 * New commands (for set/show, see "New options" below)
391 Invoke CODE by passing it to the Guile interpreter.
395 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
397 info auto-load guile-scripts [regexp]
398 Print the list of automatically loaded Guile scripts.
400 * The source command is now capable of sourcing Guile scripts.
401 This feature is dependent on the debugger being built with Guile support.
405 set print symbol-loading (off|brief|full)
406 show print symbol-loading
407 Control whether to print informational messages when loading symbol
408 information for a file. The default is "full", but when debugging
409 programs with large numbers of shared libraries the amount of output
412 set guile print-stack (none|message|full)
413 show guile print-stack
414 Show a stack trace when an error is encountered in a Guile script.
416 set auto-load guile-scripts (on|off)
417 show auto-load guile-scripts
418 Control auto-loading of Guile script files.
420 maint ada set ignore-descriptive-types (on|off)
421 maint ada show ignore-descriptive-types
422 Control whether the debugger should ignore descriptive types in Ada
423 programs. The default is not to ignore the descriptive types. See
424 the user manual for more details on descriptive types and the intended
425 usage of this option.
427 set auto-connect-native-target
429 Control whether GDB is allowed to automatically connect to the
430 native target for the run, attach, etc. commands when not connected
431 to any target yet. See also "target native" below.
433 set record btrace replay-memory-access (read-only|read-write)
434 show record btrace replay-memory-access
435 Control what memory accesses are allowed during replay.
437 maint set target-async (on|off)
438 maint show target-async
439 This controls whether GDB targets operate in synchronous or
440 asynchronous mode. Normally the default is asynchronous, if it is
441 available; but this can be changed to more easily debug problems
442 occurring only in synchronous mode.
444 set mi-async (on|off)
446 Control whether MI asynchronous mode is preferred. This supersedes
447 "set target-async" of previous GDB versions.
449 * "set target-async" is deprecated as a CLI option and is now an alias
450 for "set mi-async" (only puts MI into async mode).
452 * Background execution commands (e.g., "c&", "s&", etc.) are now
453 possible ``out of the box'' if the target supports them. Previously
454 the user would need to explicitly enable the possibility with the
455 "set target-async on" command.
457 * New features in the GDB remote stub, GDBserver
459 ** New option --debug-format=option1[,option2,...] allows one to add
460 additional text to each output. At present only timestamps
461 are supported: --debug-format=timestamps.
462 Timestamps can also be turned on with the
463 "monitor set debug-format timestamps" command from GDB.
465 * The 'record instruction-history' command now starts counting instructions
466 at one. This also affects the instruction ranges reported by the
467 'record function-call-history' command when given the /i modifier.
469 * The command 'record function-call-history' supports a new modifier '/c' to
470 indent the function names based on their call stack depth.
471 The fields for the '/i' and '/l' modifier have been reordered.
472 The source line range is now prefixed with 'at'.
473 The instruction range is now prefixed with 'inst'.
474 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
475 "record instruction-history" and "list" commands.
477 * The ranges given as arguments to the 'record function-call-history' and
478 'record instruction-history' commands are now inclusive.
480 * The btrace record target now supports the 'record goto' command.
481 For locations inside the execution trace, the back trace is computed
482 based on the information stored in the execution trace.
484 * The btrace record target supports limited reverse execution and replay.
485 The target does not record data and therefore does not allow reading
488 * The "catch syscall" command now works on s390*-linux* targets.
490 * The "compare-sections" command is no longer specific to target
491 remote. It now works with all targets.
493 * All native targets are now consistently called "native".
494 Consequently, the "target child", "target GNU", "target djgpp",
495 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
496 commands have been replaced with "target native". The QNX/NTO port
497 leaves the "procfs" target in place and adds a "native" target for
498 consistency with other ports. The impact on users should be minimal
499 as these commands previously either throwed an error, or were
500 no-ops. The target's name is visible in the output of the following
501 commands: "help target", "info target", "info files", "maint print
504 * The "target native" command now connects to the native target. This
505 can be used to launch native programs even when "set
506 auto-connect-native-target" is set to off.
508 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.
510 * Support for Intel(R) AVX-512 registers on GNU/Linux.
511 Support displaying and modifying Intel(R) AVX-512 registers
512 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
516 qXfer:btrace:read's annex
517 The qXfer:btrace:read packet supports a new annex 'delta' to read
518 branch trace incrementally.
522 ** Valid Python operations on gdb.Value objects representing
523 structs/classes invoke the corresponding overloaded operators if
525 ** New `Xmethods' feature in the Python API. Xmethods are
526 additional methods or replacements for existing methods of a C++
527 class. This feature is useful for those cases where a method
528 defined in C++ source code could be inlined or optimized out by
529 the compiler, making it unavailable to GDB.
532 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
534 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
535 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
536 its alias "share", instead.
538 * The commands "set remotebaud" and "show remotebaud" are no longer
539 supported. Use "set serial baud" and "show serial baud" (respectively)
544 ** A new option "-gdb-set mi-async" replaces "-gdb-set
545 target-async". The latter is left as a deprecated alias of the
546 former for backward compatibility. If the target supports it,
547 CLI background execution commands are now always possible by
548 default, independently of whether the frontend stated a
549 preference for asynchronous execution with "-gdb-set mi-async".
550 Previously "-gdb-set target-async off" affected both MI execution
551 commands and CLI execution commands.
553 *** Changes in GDB 7.7
555 * Improved support for process record-replay and reverse debugging on
556 arm*-linux* targets. Support for thumb32 and syscall instruction
557 recording has been added.
559 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
561 * GDB now supports Fission DWP file format version 2.
562 http://gcc.gnu.org/wiki/DebugFission
564 * New convenience function "$_isvoid", to check whether an expression
565 is void. A void expression is an expression where the type of the
566 result is "void". For example, some convenience variables may be
567 "void" when evaluated (e.g., "$_exitcode" before the execution of
568 the program being debugged; or an undefined convenience variable).
569 Another example, when calling a function whose return type is
572 * The "maintenance print objfiles" command now takes an optional regexp.
574 * The "catch syscall" command now works on arm*-linux* targets.
576 * GDB now consistently shows "<not saved>" when printing values of
577 registers the debug info indicates have not been saved in the frame
578 and there's nowhere to retrieve them from
579 (callee-saved/call-clobbered registers):
584 (gdb) info registers rax
587 Before, the former would print "<optimized out>", and the latter
588 "*value not available*".
590 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
595 ** Frame filters and frame decorators have been added.
596 ** Temporary breakpoints are now supported.
597 ** Line tables representation has been added.
598 ** New attribute 'parent_type' for gdb.Field objects.
599 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
600 ** New attribute 'name' for gdb.Type objects.
604 Nios II ELF nios2*-*-elf
605 Nios II GNU/Linux nios2*-*-linux
606 Texas Instruments MSP430 msp430*-*-elf
608 * Removed native configurations
610 Support for these a.out NetBSD and OpenBSD obsolete configurations has
611 been removed. ELF variants of these configurations are kept supported.
613 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
614 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
615 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
616 i[34567]86-*-openbsd3.[0-3]
617 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
618 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
619 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
623 Like "catch throw", but catches a re-thrown exception.
625 Renamed from old "maint check-symtabs".
627 Perform consistency checks on symtabs.
629 Expand symtabs matching an optional regexp.
632 Display the details of GDB configure-time options.
634 maint set|show per-command
635 maint set|show per-command space
636 maint set|show per-command time
637 maint set|show per-command symtab
638 Enable display of per-command gdb resource usage.
640 remove-symbol-file FILENAME
641 remove-symbol-file -a ADDRESS
642 Remove a symbol file added via add-symbol-file. The file to remove
643 can be identified by its filename or by an address that lies within
644 the boundaries of this symbol file in memory.
647 info exceptions REGEXP
648 Display the list of Ada exceptions defined in the program being
649 debugged. If provided, only the exceptions whose names match REGEXP
654 set debug symfile off|on
656 Control display of debugging info regarding reading symbol files and
657 symbol tables within those files
659 set print raw frame-arguments
660 show print raw frame-arguments
661 Set/show whether to print frame arguments in raw mode,
662 disregarding any defined pretty-printers.
664 set remote trace-status-packet
665 show remote trace-status-packet
666 Set/show the use of remote protocol qTStatus packet.
670 Control display of debugging messages related to Nios II targets.
674 Control whether target-assisted range stepping is enabled.
676 set startup-with-shell
677 show startup-with-shell
678 Specifies whether Unix child processes are started via a shell or
683 Use the target memory cache for accesses to the code segment. This
684 improves performance of remote debugging (particularly disassembly).
686 * You can now use a literal value 'unlimited' for options that
687 interpret 0 or -1 as meaning "unlimited". E.g., "set
688 trace-buffer-size unlimited" is now an alias for "set
689 trace-buffer-size -1" and "set height unlimited" is now an alias for
692 * The "set debug symtab-create" debugging option of GDB has been changed to
693 accept a verbosity level. 0 means "off", 1 provides basic debugging
694 output, and values of 2 or greater provides more verbose output.
696 * New command-line options
698 Display the details of GDB configure-time options.
700 * The command 'tsave' can now support new option '-ctf' to save trace
701 buffer in Common Trace Format.
703 * Newly installed $prefix/bin/gcore acts as a shell interface for the
706 * GDB now implements the the C++ 'typeid' operator.
708 * The new convenience variable $_exception holds the exception being
709 thrown or caught at an exception-related catchpoint.
711 * The exception-related catchpoints, like "catch throw", now accept a
712 regular expression which can be used to filter exceptions by type.
714 * The new convenience variable $_exitsignal is automatically set to
715 the terminating signal number when the program being debugged dies
716 due to an uncaught signal.
720 ** All MI commands now accept an optional "--language" option.
721 Support for this feature can be verified by using the "-list-features"
722 command, which should contain "language-option".
724 ** The new command -info-gdb-mi-command allows the user to determine
725 whether a GDB/MI command is supported or not.
727 ** The "^error" result record returned when trying to execute an undefined
728 GDB/MI command now provides a variable named "code" whose content is the
729 "undefined-command" error code. Support for this feature can be verified
730 by using the "-list-features" command, which should contain
731 "undefined-command-error-code".
733 ** The -trace-save MI command can optionally save trace buffer in Common
736 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
738 ** The command -data-list-register-values now accepts an optional
739 "--skip-unavailable" option. When used, only the available registers
742 ** The new command -trace-frame-collected dumps collected variables,
743 computed expressions, tvars, memory and registers in a traceframe.
745 ** The commands -stack-list-locals, -stack-list-arguments and
746 -stack-list-variables now accept an option "--skip-unavailable".
747 When used, only the available locals or arguments are displayed.
749 ** The -exec-run command now accepts an optional "--start" option.
750 When used, the command follows the same semantics as the "start"
751 command, stopping the program's execution at the start of its
752 main subprogram. Support for this feature can be verified using
753 the "-list-features" command, which should contain
754 "exec-run-start-option".
756 ** The new commands -catch-assert and -catch-exceptions insert
757 catchpoints stopping the program when Ada exceptions are raised.
759 ** The new command -info-ada-exceptions provides the equivalent of
760 the new "info exceptions" command.
762 * New system-wide configuration scripts
763 A GDB installation now provides scripts suitable for use as system-wide
764 configuration scripts for the following systems:
768 * GDB now supports target-assigned range stepping with remote targets.
769 This improves the performance of stepping source lines by reducing
770 the number of control packets from/to GDB. See "New remote packets"
773 * GDB now understands the element 'tvar' in the XML traceframe info.
774 It has the id of the collected trace state variables.
776 * On S/390 targets that provide the transactional-execution feature,
777 the program interruption transaction diagnostic block (TDB) is now
778 represented as a number of additional "registers" in GDB.
784 The vCont packet supports a new 'r' action, that tells the remote
785 stub to step through an address range itself, without GDB
786 involvemement at each single-step.
788 qXfer:libraries-svr4:read's annex
789 The previously unused annex of the qXfer:libraries-svr4:read packet
790 is now used to support passing an argument list. The remote stub
791 reports support for this argument list to GDB's qSupported query.
792 The defined arguments are "start" and "prev", used to reduce work
793 necessary for library list updating, resulting in significant
796 * New features in the GDB remote stub, GDBserver
798 ** GDBserver now supports target-assisted range stepping. Currently
799 enabled on x86/x86_64 GNU/Linux targets.
801 ** GDBserver now adds element 'tvar' in the XML in the reply to
802 'qXfer:traceframe-info:read'. It has the id of the collected
803 trace state variables.
805 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
808 * New 'z' formatter for printing and examining memory, this displays the
809 value as hexadecimal zero padded on the left to the size of the type.
811 * GDB can now use Windows x64 unwinding data.
813 * The "set remotebaud" command has been replaced by "set serial baud".
814 Similarly, "show remotebaud" has been replaced by "show serial baud".
815 The "set remotebaud" and "show remotebaud" commands are still available
816 to provide backward compatibility with older versions of GDB.
818 *** Changes in GDB 7.6
820 * Target record has been renamed to record-full.
821 Record/replay is now enabled with the "record full" command.
822 This also affects settings that are associated with full record/replay
823 that have been moved from "set/show record" to "set/show record full":
825 set|show record full insn-number-max
826 set|show record full stop-at-limit
827 set|show record full memory-query
829 * A new record target "record-btrace" has been added. The new target
830 uses hardware support to record the control-flow of a process. It
831 does not support replaying the execution, but it implements the
832 below new commands for investigating the recorded execution log.
833 This new recording method can be enabled using:
837 The "record-btrace" target is only available on Intel Atom processors
838 and requires a Linux kernel 2.6.32 or later.
840 * Two new commands have been added for record/replay to give information
841 about the recorded execution without having to replay the execution.
842 The commands are only supported by "record btrace".
844 record instruction-history prints the execution history at
845 instruction granularity
847 record function-call-history prints the execution history at
850 * New native configurations
852 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
853 FreeBSD/powerpc powerpc*-*-freebsd
854 x86_64/Cygwin x86_64-*-cygwin*
855 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
859 ARM AArch64 aarch64*-*-elf
860 ARM AArch64 GNU/Linux aarch64*-*-linux
861 Lynx 178 PowerPC powerpc-*-lynx*178
862 x86_64/Cygwin x86_64-*-cygwin*
863 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
865 * If the configured location of system.gdbinit file (as given by the
866 --with-system-gdbinit option at configure time) is in the
867 data-directory (as specified by --with-gdb-datadir at configure
868 time) or in one of its subdirectories, then GDB will look for the
869 system-wide init file in the directory specified by the
870 --data-directory command-line option.
872 * New command line options:
874 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
875 other initialization files, unlike -nx which disables all of them.
877 * Removed command line options
879 -epoch This was used by the gdb mode in Epoch, an ancient fork of
882 * The 'ptype' and 'whatis' commands now accept an argument to control
885 * 'info proc' now works on some core files.
889 ** Vectors can be created with gdb.Type.vector.
891 ** Python's atexit.register now works in GDB.
893 ** Types can be pretty-printed via a Python API.
895 ** Python 3 is now supported (in addition to Python 2.4 or later)
897 ** New class gdb.Architecture exposes GDB's internal representation
898 of architecture in the Python API.
900 ** New method Frame.architecture returns the gdb.Architecture object
901 corresponding to the frame's architecture.
903 * New Python-based convenience functions:
905 ** $_memeq(buf1, buf2, length)
906 ** $_streq(str1, str2)
908 ** $_regex(str, regex)
910 * The 'cd' command now defaults to using '~' (the home directory) if not
913 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
914 default for GCC since November 2000.
916 * The command 'forward-search' can now be abbreviated as 'fo'.
918 * The command 'info tracepoints' can now display 'installed on target'
919 or 'not installed on target' for each non-pending location of tracepoint.
921 * New configure options
923 --enable-libmcheck/--disable-libmcheck
924 By default, development versions are built with -lmcheck on hosts
925 that support it, in order to help track memory corruption issues.
926 Release versions, on the other hand, are built without -lmcheck
927 by default. The --enable-libmcheck/--disable-libmcheck configure
928 options allow the user to override that default.
929 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
930 This configure option allows the user to build GDB with
931 libbabeltrace using which GDB can read Common Trace Format data.
933 * New commands (for set/show, see "New options" below)
936 Catch signals. This is similar to "handle", but allows commands and
937 conditions to be attached.
940 List the BFDs known to GDB.
942 python-interactive [command]
944 Start a Python interactive prompt, or evaluate the optional command
945 and print the result of expressions.
948 "py" is a new alias for "python".
950 enable type-printer [name]...
951 disable type-printer [name]...
952 Enable or disable type printers.
956 ** For the Renesas Super-H architecture, the "regs" command has been removed
957 (has been deprecated in GDB 7.5), and "info all-registers" should be used
962 set print type methods (on|off)
963 show print type methods
964 Control whether method declarations are displayed by "ptype".
965 The default is to show them.
967 set print type typedefs (on|off)
968 show print type typedefs
969 Control whether typedef definitions are displayed by "ptype".
970 The default is to show them.
972 set filename-display basename|relative|absolute
973 show filename-display
974 Control the way in which filenames is displayed.
975 The default is "relative", which preserves previous behavior.
977 set trace-buffer-size
978 show trace-buffer-size
979 Request target to change the size of trace buffer.
981 set remote trace-buffer-size-packet auto|on|off
982 show remote trace-buffer-size-packet
983 Control the use of the remote protocol `QTBuffer:size' packet.
987 Control display of debugging messages related to ARM AArch64.
990 set debug coff-pe-read
991 show debug coff-pe-read
992 Control display of debugging messages related to reading of COFF/PE
997 Control display of debugging messages related to Mach-O symbols
1000 set debug notification
1001 show debug notification
1002 Control display of debugging info for async remote notification.
1006 ** Command parameter changes are now notified using new async record
1007 "=cmd-param-changed".
1008 ** Trace frame changes caused by command "tfind" are now notified using
1009 new async record "=traceframe-changed".
1010 ** The creation, deletion and modification of trace state variables
1011 are now notified using new async records "=tsv-created",
1012 "=tsv-deleted" and "=tsv-modified".
1013 ** The start and stop of process record are now notified using new
1014 async record "=record-started" and "=record-stopped".
1015 ** Memory changes are now notified using new async record
1017 ** The data-disassemble command response will include a "fullname" field
1018 containing the absolute file name when source has been requested.
1019 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1020 command, to allow pattern filling of memory areas.
1021 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1022 library load/unload events.
1023 ** The response to breakpoint commands and breakpoint async records
1024 includes an "installed" field containing a boolean state about each
1025 non-pending tracepoint location is whether installed on target or not.
1026 ** Output of the "-trace-status" command includes a "trace-file" field
1027 containing the name of the trace file being examined. This field is
1028 optional, and only present when examining a trace file.
1029 ** The "fullname" field is now always present along with the "file" field,
1030 even if the file cannot be found by GDB.
1032 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1033 You must have the LZMA library available when configuring GDB for this
1034 feature to be enabled. For more information, see:
1035 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1037 * New remote packets
1040 Set the size of trace buffer. The remote stub reports support for this
1041 packet to gdb's qSupported query.
1044 Enable Branch Trace Store (BTS)-based branch tracing for the current
1045 thread. The remote stub reports support for this packet to gdb's
1049 Disable branch tracing for the current thread. The remote stub reports
1050 support for this packet to gdb's qSupported query.
1053 Read the traced branches for the current thread. The remote stub
1054 reports support for this packet to gdb's qSupported query.
1056 *** Changes in GDB 7.5
1058 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1059 for more x32 ABI info.
1061 * GDB now supports access to MIPS DSP registers on Linux targets.
1063 * GDB now supports debugging microMIPS binaries.
1065 * The "info os" command on GNU/Linux can now display information on
1066 several new classes of objects managed by the operating system:
1067 "info os procgroups" lists process groups
1068 "info os files" lists file descriptors
1069 "info os sockets" lists internet-domain sockets
1070 "info os shm" lists shared-memory regions
1071 "info os semaphores" lists semaphores
1072 "info os msg" lists message queues
1073 "info os modules" lists loaded kernel modules
1075 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1076 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1077 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1078 options and inspect the probe arguments using the new $_probe_arg family
1079 of convenience variables. You can obtain more information about SystemTap
1080 in <http://sourceware.org/systemtap/>.
1082 * GDB now supports reversible debugging on ARM, it allows you to
1083 debug basic ARM and THUMB instructions, and provides
1084 record/replay support.
1086 * The option "symbol-reloading" has been deleted as it is no longer used.
1090 ** GDB commands implemented in Python can now be put in command class
1093 ** The "maint set python print-stack on|off" is now deleted.
1095 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1096 apply "flag enum"-style pretty-printing to any enum.
1098 ** gdb.lookup_symbol can now work when there is no current frame.
1100 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1101 the source at which the symbol was defined.
1103 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1104 method 'value'. The former indicates whether the symbol needs a
1105 frame in order to compute its value, and the latter computes the
1108 ** A new method 'referenced_value' on gdb.Value objects which can
1109 dereference pointer as well as C++ reference values.
1111 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1112 which return the global and static blocks (as gdb.Block objects),
1113 of the underlying symbol table, respectively.
1115 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1116 object associated with a PC value.
1118 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1119 of the address range occupied by code for the current source line.
1121 * Go language support.
1122 GDB now supports debugging programs written in the Go programming
1125 * GDBserver now supports stdio connections.
1126 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1128 * The binary "gdbtui" can no longer be built or installed.
1129 Use "gdb -tui" instead.
1131 * GDB will now print "flag" enums specially. A flag enum is one where
1132 all the enumerator values have no bits in common when pairwise
1133 "and"ed. When printing a value whose type is a flag enum, GDB will
1134 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1135 (gdb) print (enum E) 3
1138 * The filename part of a linespec will now match trailing components
1139 of a source file name. For example, "break gcc/expr.c:1000" will
1140 now set a breakpoint in build/gcc/expr.c, but not
1141 build/libcpp/expr.c.
1143 * The "info proc" and "generate-core-file" commands will now also
1144 work on remote targets connected to GDBserver on Linux.
1146 * The command "info catch" has been removed. It has been disabled
1147 since December 2007.
1149 * The "catch exception" and "catch assert" commands now accept
1150 a condition at the end of the command, much like the "break"
1151 command does. For instance:
1153 (gdb) catch exception Constraint_Error if Barrier = True
1155 Previously, it was possible to add a condition to such catchpoints,
1156 but it had to be done as a second step, after the catchpoint had been
1157 created, using the "condition" command.
1159 * The "info static-tracepoint-marker" command will now also work on
1160 native Linux targets with in-process agent.
1162 * GDB can now set breakpoints on inlined functions.
1164 * The .gdb_index section has been updated to include symbols for
1165 inlined functions. GDB will ignore older .gdb_index sections by
1166 default, which could cause symbol files to be loaded more slowly
1167 until their .gdb_index sections can be recreated. The new command
1168 "set use-deprecated-index-sections on" will cause GDB to use any older
1169 .gdb_index sections it finds. This will restore performance, but the
1170 ability to set breakpoints on inlined functions will be lost in symbol
1171 files with older .gdb_index sections.
1173 The .gdb_index section has also been updated to record more information
1174 about each symbol. This speeds up the "info variables", "info functions"
1175 and "info types" commands when used with programs having the .gdb_index
1176 section, as well as speeding up debugging with shared libraries using
1177 the .gdb_index section.
1179 * Ada support for GDB/MI Variable Objects has been added.
1181 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1186 ** New command -info-os is the MI equivalent of "info os".
1188 ** Output logs ("set logging" and related) now include MI output.
1192 ** "set use-deprecated-index-sections on|off"
1193 "show use-deprecated-index-sections on|off"
1194 Controls the use of deprecated .gdb_index sections.
1196 ** "catch load" and "catch unload" can be used to stop when a shared
1197 library is loaded or unloaded, respectively.
1199 ** "enable count" can be used to auto-disable a breakpoint after
1202 ** "info vtbl" can be used to show the virtual method tables for
1203 C++ and Java objects.
1205 ** "explore" and its sub commands "explore value" and "explore type"
1206 can be used to recursively explore values and types of
1207 expressions. These commands are available only if GDB is
1208 configured with '--with-python'.
1210 ** "info auto-load" shows status of all kinds of auto-loaded files,
1211 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1212 sequences of commands files, "info auto-load python-scripts"
1213 shows status of auto-loading Python script files,
1214 "info auto-load local-gdbinit" shows status of loading init file
1215 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1216 status of inferior specific thread debugging shared library loading.
1218 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1219 and "show auto-load-scripts" commands have been deprecated, use their
1220 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1221 and "show auto-load python-scripts" counterparts instead.
1223 ** "dprintf location,format,args..." creates a dynamic printf, which
1224 is basically a breakpoint that does a printf and immediately
1225 resumes your program's execution, so it is like a printf that you
1226 can insert dynamically at runtime instead of at compiletime.
1228 ** "set print symbol"
1230 Controls whether GDB attempts to display the symbol, if any,
1231 corresponding to addresses it prints. This defaults to "on", but
1232 you can set it to "off" to restore GDB's previous behavior.
1234 * Deprecated commands
1236 ** For the Renesas Super-H architecture, the "regs" command has been
1237 deprecated, and "info all-registers" should be used instead.
1241 Renesas RL78 rl78-*-elf
1242 HP OpenVMS ia64 ia64-hp-openvms*
1244 * GDBserver supports evaluation of breakpoint conditions. When
1245 support is advertised by GDBserver, GDB may be told to send the
1246 breakpoint conditions in bytecode form to GDBserver. GDBserver
1247 will only report the breakpoint trigger to GDB when its condition
1252 set mips compression
1253 show mips compression
1254 Select the compressed ISA encoding used in functions that have no symbol
1255 information available. The encoding can be set to either of:
1258 and is updated automatically from ELF file flags if available.
1260 set breakpoint condition-evaluation
1261 show breakpoint condition-evaluation
1262 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1263 GDBserver ("target"). Default option "auto" chooses the most efficient
1265 This option can improve debugger efficiency depending on the speed of the
1269 Disable auto-loading globally.
1272 Show auto-loading setting of all kinds of auto-loaded files.
1274 set auto-load gdb-scripts on|off
1275 show auto-load gdb-scripts
1276 Control auto-loading of GDB canned sequences of commands files.
1278 set auto-load python-scripts on|off
1279 show auto-load python-scripts
1280 Control auto-loading of Python script files.
1282 set auto-load local-gdbinit on|off
1283 show auto-load local-gdbinit
1284 Control loading of init file (.gdbinit) from current directory.
1286 set auto-load libthread-db on|off
1287 show auto-load libthread-db
1288 Control auto-loading of inferior specific thread debugging shared library.
1290 set auto-load scripts-directory <dir1>[:<dir2>...]
1291 show auto-load scripts-directory
1292 Set a list of directories from which to load auto-loaded scripts.
1293 Automatically loaded Python scripts and GDB scripts are located in one
1294 of the directories listed by this option.
1295 The delimiter (':' above) may differ according to the host platform.
1297 set auto-load safe-path <dir1>[:<dir2>...]
1298 show auto-load safe-path
1299 Set a list of directories from which it is safe to auto-load files.
1300 The delimiter (':' above) may differ according to the host platform.
1302 set debug auto-load on|off
1303 show debug auto-load
1304 Control display of debugging info for auto-loading the files above.
1306 set dprintf-style gdb|call|agent
1308 Control the way in which a dynamic printf is performed; "gdb"
1309 requests a GDB printf command, while "call" causes dprintf to call a
1310 function in the inferior. "agent" requests that the target agent
1311 (such as GDBserver) do the printing.
1313 set dprintf-function <expr>
1314 show dprintf-function
1315 set dprintf-channel <expr>
1316 show dprintf-channel
1317 Set the function and optional first argument to the call when using
1318 the "call" style of dynamic printf.
1320 set disconnected-dprintf on|off
1321 show disconnected-dprintf
1322 Control whether agent-style dynamic printfs continue to be in effect
1323 after GDB disconnects.
1325 * New configure options
1327 --with-auto-load-dir
1328 Configure default value for the 'set auto-load scripts-directory'
1329 setting above. It defaults to '$debugdir:$datadir/auto-load',
1330 $debugdir representing global debugging info directories (available
1331 via 'show debug-file-directory') and $datadir representing GDB's data
1332 directory (available via 'show data-directory').
1334 --with-auto-load-safe-path
1335 Configure default value for the 'set auto-load safe-path' setting
1336 above. It defaults to the --with-auto-load-dir setting.
1338 --without-auto-load-safe-path
1339 Set 'set auto-load safe-path' to '/', effectively disabling this
1342 * New remote packets
1344 z0/z1 conditional breakpoints extension
1346 The z0/z1 breakpoint insertion packets have been extended to carry
1347 a list of conditional expressions over to the remote stub depending on the
1348 condition evaluation mode. The use of this extension can be controlled
1349 via the "set remote conditional-breakpoints-packet" command.
1353 Specify the signals which the remote stub may pass to the debugged
1354 program without GDB involvement.
1356 * New command line options
1358 --init-command=FILE, -ix Like --command, -x but execute it
1359 before loading inferior.
1360 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1361 execute it before loading inferior.
1363 *** Changes in GDB 7.4
1365 * GDB now handles ambiguous linespecs more consistently; the existing
1366 FILE:LINE support has been expanded to other types of linespecs. A
1367 breakpoint will now be set on all matching locations in all
1368 inferiors, and locations will be added or removed according to
1371 * GDB now allows you to skip uninteresting functions and files when
1372 stepping with the "skip function" and "skip file" commands.
1374 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1375 and "show remote hardware-watchpoint-length-limit". These allows to
1376 set or show the maximum length limit (in bytes) of a remote
1377 target hardware watchpoint.
1379 This allows e.g. to use "unlimited" hardware watchpoints with the
1380 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1381 watchpoints are slower than real hardware watchpoints but are
1382 significantly faster than gdb software watchpoints.
1386 ** The register_pretty_printer function in module gdb.printing now takes
1387 an optional `replace' argument. If True, the new printer replaces any
1390 ** The "maint set python print-stack on|off" command has been
1391 deprecated and will be deleted in GDB 7.5.
1392 A new command: "set python print-stack none|full|message" has
1393 replaced it. Additionally, the default for "print-stack" is
1394 now "message", which just prints the error message without
1397 ** A prompt substitution hook (prompt_hook) is now available to the
1400 ** A new Python module, gdb.prompt has been added to the GDB Python
1401 modules library. This module provides functionality for
1402 escape sequences in prompts (used by set/show
1403 extended-prompt). These escape sequences are replaced by their
1404 corresponding value.
1406 ** Python commands and convenience-functions located in
1407 'data-directory'/python/gdb/command and
1408 'data-directory'/python/gdb/function are now automatically loaded
1411 ** Blocks now provide four new attributes. global_block and
1412 static_block will return the global and static blocks
1413 respectively. is_static and is_global are boolean attributes
1414 that indicate if the block is one of those two types.
1416 ** Symbols now provide the "type" attribute, the type of the symbol.
1418 ** The "gdb.breakpoint" function has been deprecated in favor of
1421 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1422 of a function. This class is based on the "finish" command
1423 available in the CLI.
1425 ** Type objects for struct and union types now allow access to
1426 the fields using standard Python dictionary (mapping) methods.
1427 For example, "some_type['myfield']" now works, as does
1428 "some_type.items()".
1430 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1433 ** A new function, "deep_items" has been added to the gdb.types
1434 module in the GDB Python modules library. This function returns
1435 an iterator over the fields of a struct or union type. Unlike
1436 the standard Python "iteritems" method, it will recursively traverse
1437 any anonymous fields.
1441 ** "*stopped" events can report several new "reason"s, such as
1444 ** Breakpoint changes are now notified using new async records, like
1445 "=breakpoint-modified".
1447 ** New command -ada-task-info.
1449 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1450 $sdir specifies the default system locations of shared libraries.
1451 $pdir specifies the directory where the libpthread used by the application
1454 GDB no longer looks in $sdir and $pdir after it has searched the directories
1455 mentioned in libthread-db-search-path. If you want to search those
1456 directories, they must be specified in libthread-db-search-path.
1457 The default value of libthread-db-search-path on GNU/Linux and Solaris
1458 systems is now "$sdir:$pdir".
1460 $pdir is not supported by gdbserver, it is currently ignored.
1461 $sdir is supported by gdbserver.
1463 * New configure option --with-iconv-bin.
1464 When using the internationalization support like the one in the GNU C
1465 library, GDB will invoke the "iconv" program to get a list of supported
1466 character sets. If this program lives in a non-standard location, one can
1467 use this option to specify where to find it.
1469 * When natively debugging programs on PowerPC BookE processors running
1470 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1471 watchpoints, which specify a mask in addition to an address to watch.
1472 The mask specifies that some bits of an address (the bits which are
1473 reset in the mask) should be ignored when matching the address accessed
1474 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1475 section in the user manual for more details.
1477 * The new option --once causes GDBserver to stop listening for connections once
1478 the first connection is made. The listening port used by GDBserver will
1479 become available after that.
1481 * New commands "info macros" and "alias" have been added.
1483 * New function parameters suffix @entry specifies value of function parameter
1484 at the time the function got called. Entry values are available only since
1490 "!" is now an alias of the "shell" command.
1491 Note that no space is needed between "!" and SHELL COMMAND.
1495 watch EXPRESSION mask MASK_VALUE
1496 The watch command now supports the mask argument which allows creation
1497 of masked watchpoints, if the current architecture supports this feature.
1499 info auto-load-scripts [REGEXP]
1500 This command was formerly named "maintenance print section-scripts".
1501 It is now generally useful and is no longer a maintenance-only command.
1503 info macro [-all] [--] MACRO
1504 The info macro command has new options `-all' and `--'. The first for
1505 printing all definitions of a macro. The second for explicitly specifying
1506 the end of arguments and the beginning of the macro name in case the macro
1507 name starts with a hyphen.
1509 collect[/s] EXPRESSIONS
1510 The tracepoint collect command now takes an optional modifier "/s"
1511 that directs it to dereference pointer-to-character types and
1512 collect the bytes of memory up to a zero byte. The behavior is
1513 similar to what you see when you use the regular print command on a
1514 string. An optional integer following the "/s" sets a bound on the
1515 number of bytes that will be collected.
1518 The trace start command now interprets any supplied arguments as a
1519 note to be recorded with the trace run, with an effect similar to
1520 setting the variable trace-notes.
1523 The trace stop command now interprets any arguments as a note to be
1524 mentioned along with the tstatus report that the trace was stopped
1525 with a command. The effect is similar to setting the variable
1528 * Tracepoints can now be enabled and disabled at any time after a trace
1529 experiment has been started using the standard "enable" and "disable"
1530 commands. It is now possible to start a trace experiment with no enabled
1531 tracepoints; GDB will display a warning, but will allow the experiment to
1532 begin, assuming that tracepoints will be enabled as needed while the trace
1535 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1536 locations with 4-byte instructions, when they were previously
1537 limited to locations with instructions of 5 bytes or longer.
1541 set debug dwarf2-read
1542 show debug dwarf2-read
1543 Turns on or off display of debugging messages related to reading
1544 DWARF debug info. The default is off.
1546 set debug symtab-create
1547 show debug symtab-create
1548 Turns on or off display of debugging messages related to symbol table
1549 creation. The default is off.
1552 show extended-prompt
1553 Set the GDB prompt, and allow escape sequences to be inserted to
1554 display miscellaneous information (see 'help set extended-prompt'
1555 for the list of sequences). This prompt (and any information
1556 accessed through the escape sequences) is updated every time the
1557 prompt is displayed.
1559 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1560 show print entry-values
1561 Set printing of frame argument values at function entry. In some cases
1562 GDB can determine the value of function argument which was passed by the
1563 function caller, even if the value was modified inside the called function.
1565 set debug entry-values
1566 show debug entry-values
1567 Control display of debugging info for determining frame argument values at
1568 function entry and virtual tail call frames.
1570 set basenames-may-differ
1571 show basenames-may-differ
1572 Set whether a source file may have multiple base names.
1573 (A "base name" is the name of a file with the directory part removed.
1574 Example: The base name of "/home/user/hello.c" is "hello.c".)
1575 If set, GDB will canonicalize file names (e.g., expand symlinks)
1576 before comparing them. Canonicalization is an expensive operation,
1577 but it allows the same file be known by more than one base name.
1578 If not set (the default), all source files are assumed to have just
1579 one base name, and gdb will do file name comparisons more efficiently.
1585 Set a user name and notes for the current and any future trace runs.
1586 This is useful for long-running and/or disconnected traces, to
1587 inform others (or yourself) as to who is running the trace, supply
1588 contact information, or otherwise explain what is going on.
1590 set trace-stop-notes
1591 show trace-stop-notes
1592 Set a note attached to the trace run, that is displayed when the
1593 trace has been stopped by a tstop command. This is useful for
1594 instance as an explanation, if you are stopping a trace run that was
1595 started by someone else.
1597 * New remote packets
1601 Dynamically enable a tracepoint in a started trace experiment.
1605 Dynamically disable a tracepoint in a started trace experiment.
1609 Set the user and notes of the trace run.
1613 Query the current status of a tracepoint.
1617 Query the minimum length of instruction at which a fast tracepoint may
1620 * Dcache size (number of lines) and line-size are now runtime-configurable
1621 via "set dcache line" and "set dcache line-size" commands.
1625 Texas Instruments TMS320C6x tic6x-*-*
1629 Renesas RL78 rl78-*-elf
1631 *** Changes in GDB 7.3.1
1633 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1635 *** Changes in GDB 7.3
1637 * GDB has a new command: "thread find [REGEXP]".
1638 It finds the thread id whose name, target id, or thread extra info
1639 matches the given regular expression.
1641 * The "catch syscall" command now works on mips*-linux* targets.
1643 * The -data-disassemble MI command now supports modes 2 and 3 for
1644 dumping the instruction opcodes.
1646 * New command line options
1648 -data-directory DIR Specify DIR as the "data-directory".
1649 This is mostly for testing purposes.
1651 * The "maint set python auto-load on|off" command has been renamed to
1652 "set auto-load-scripts on|off".
1654 * GDB has a new command: "set directories".
1655 It is like the "dir" command except that it replaces the
1656 source path list instead of augmenting it.
1658 * GDB now understands thread names.
1660 On GNU/Linux, "info threads" will display the thread name as set by
1661 prctl or pthread_setname_np.
1663 There is also a new command, "thread name", which can be used to
1664 assign a name internally for GDB to display.
1667 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1668 has been integrated into GDB.
1672 ** The function gdb.Write now accepts an optional keyword 'stream'.
1673 This keyword, when provided, will direct the output to either
1674 stdout, stderr, or GDB's logging output.
1676 ** Parameters can now be be sub-classed in Python, and in particular
1677 you may implement the get_set_doc and get_show_doc functions.
1678 This improves how Parameter set/show documentation is processed
1679 and allows for more dynamic content.
1681 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1682 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1683 have an is_valid method.
1685 ** Breakpoints can now be sub-classed in Python, and in particular
1686 you may implement a 'stop' function that is executed each time
1687 the inferior reaches that breakpoint.
1689 ** New function gdb.lookup_global_symbol looks up a global symbol.
1691 ** GDB values in Python are now callable if the value represents a
1692 function. For example, if 'some_value' represents a function that
1693 takes two integer parameters and returns a value, you can call
1694 that function like so:
1696 result = some_value (10,20)
1698 ** Module gdb.types has been added.
1699 It contains a collection of utilities for working with gdb.Types objects:
1700 get_basic_type, has_field, make_enum_dict.
1702 ** Module gdb.printing has been added.
1703 It contains utilities for writing and registering pretty-printers.
1704 New classes: PrettyPrinter, SubPrettyPrinter,
1705 RegexpCollectionPrettyPrinter.
1706 New function: register_pretty_printer.
1708 ** New commands "info pretty-printers", "enable pretty-printer" and
1709 "disable pretty-printer" have been added.
1711 ** gdb.parameter("directories") is now available.
1713 ** New function gdb.newest_frame returns the newest frame in the
1716 ** The gdb.InferiorThread class has a new "name" attribute. This
1717 holds the thread's name.
1719 ** Python Support for Inferior events.
1720 Python scripts can add observers to be notified of events
1721 occurring in the process being debugged.
1722 The following events are currently supported:
1723 - gdb.events.cont Continue event.
1724 - gdb.events.exited Inferior exited event.
1725 - gdb.events.stop Signal received, and Breakpoint hit events.
1729 ** GDB now puts template parameters in scope when debugging in an
1730 instantiation. For example, if you have:
1732 template<int X> int func (void) { return X; }
1734 then if you step into func<5>, "print X" will show "5". This
1735 feature requires proper debuginfo support from the compiler; it
1736 was added to GCC 4.5.
1738 ** The motion commands "next", "finish", "until", and "advance" now
1739 work better when exceptions are thrown. In particular, GDB will
1740 no longer lose control of the inferior; instead, the GDB will
1741 stop the inferior at the point at which the exception is caught.
1742 This functionality requires a change in the exception handling
1743 code that was introduced in GCC 4.5.
1745 * GDB now follows GCC's rules on accessing volatile objects when
1746 reading or writing target state during expression evaluation.
1747 One notable difference to prior behavior is that "print x = 0"
1748 no longer generates a read of x; the value of the assignment is
1749 now always taken directly from the value being assigned.
1751 * GDB now has some support for using labels in the program's source in
1752 linespecs. For instance, you can use "advance label" to continue
1753 execution to a label.
1755 * GDB now has support for reading and writing a new .gdb_index
1756 section. This section holds a fast index of DWARF debugging
1757 information and can be used to greatly speed up GDB startup and
1758 operation. See the documentation for `save gdb-index' for details.
1760 * The "watch" command now accepts an optional "-location" argument.
1761 When used, this causes GDB to watch the memory referred to by the
1762 expression. Such a watchpoint is never deleted due to it going out
1765 * GDB now supports thread debugging of core dumps on GNU/Linux.
1767 GDB now activates thread debugging using the libthread_db library
1768 when debugging GNU/Linux core dumps, similarly to when debugging
1769 live processes. As a result, when debugging a core dump file, GDB
1770 is now able to display pthread_t ids of threads. For example, "info
1771 threads" shows the same output as when debugging the process when it
1772 was live. In earlier releases, you'd see something like this:
1775 * 1 LWP 6780 main () at main.c:10
1777 While now you see this:
1780 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1782 It is also now possible to inspect TLS variables when debugging core
1785 When debugging a core dump generated on a machine other than the one
1786 used to run GDB, you may need to point GDB at the correct
1787 libthread_db library with the "set libthread-db-search-path"
1788 command. See the user manual for more details on this command.
1790 * When natively debugging programs on PowerPC BookE processors running
1791 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1792 which stop execution of the inferior whenever it executes an instruction
1793 at any address within the specified range. See the "PowerPC Embedded"
1794 section in the user manual for more details.
1796 * New features in the GDB remote stub, GDBserver
1798 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1799 and i686 LynxOS (version 5.x).
1801 ** GDBserver is now supported on Blackfin Linux.
1803 * New native configurations
1805 ia64 HP-UX ia64-*-hpux*
1809 Analog Devices, Inc. Blackfin Processor bfin-*
1811 * Ada task switching is now supported on sparc-elf targets when
1812 debugging a program using the Ravenscar Profile. For more information,
1813 see the "Tasking Support when using the Ravenscar Profile" section
1814 in the GDB user manual.
1816 * Guile support was removed.
1818 * New features in the GNU simulator
1820 ** The --map-info flag lists all known core mappings.
1822 ** CFI flashes may be simulated via the "cfi" device.
1824 *** Changes in GDB 7.2
1826 * Shared library support for remote targets by default
1828 When GDB is configured for a generic, non-OS specific target, like
1829 for example, --target=arm-eabi or one of the many *-*-elf targets,
1830 GDB now queries remote stubs for loaded shared libraries using the
1831 `qXfer:libraries:read' packet. Previously, shared library support
1832 was always disabled for such configurations.
1836 ** Argument Dependent Lookup (ADL)
1838 In C++ ADL lookup directs function search to the namespaces of its
1839 arguments even if the namespace has not been imported.
1849 Here the compiler will search for `foo' in the namespace of 'b'
1850 and find A::foo. GDB now supports this. This construct is commonly
1851 used in the Standard Template Library for operators.
1853 ** Improved User Defined Operator Support
1855 In addition to member operators, GDB now supports lookup of operators
1856 defined in a namespace and imported with a `using' directive, operators
1857 defined in the global scope, operators imported implicitly from an
1858 anonymous namespace, and the ADL operators mentioned in the previous
1860 GDB now also supports proper overload resolution for all the previously
1861 mentioned flavors of operators.
1863 ** static const class members
1865 Printing of static const class members that are initialized in the
1866 class definition has been fixed.
1868 * Windows Thread Information Block access.
1870 On Windows targets, GDB now supports displaying the Windows Thread
1871 Information Block (TIB) structure. This structure is visible either
1872 by using the new command `info w32 thread-information-block' or, by
1873 dereferencing the new convenience variable named `$_tlb', a
1874 thread-specific pointer to the TIB. This feature is also supported
1875 when remote debugging using GDBserver.
1877 * Static tracepoints
1879 Static tracepoints are calls in the user program into a tracing
1880 library. One such library is a port of the LTTng kernel tracer to
1881 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1882 When debugging with GDBserver, GDB now supports combining the GDB
1883 tracepoint machinery with such libraries. For example: the user can
1884 use GDB to probe a static tracepoint marker (a call from the user
1885 program into the tracing library) with the new "strace" command (see
1886 "New commands" below). This creates a "static tracepoint" in the
1887 breakpoint list, that can be manipulated with the same feature set
1888 as fast and regular tracepoints. E.g., collect registers, local and
1889 global variables, collect trace state variables, and define
1890 tracepoint conditions. In addition, the user can collect extra
1891 static tracepoint marker specific data, by collecting the new
1892 $_sdata internal variable. When analyzing the trace buffer, you can
1893 inspect $_sdata like any other variable available to GDB. For more
1894 information, see the "Tracepoints" chapter in GDB user manual. New
1895 remote packets have been defined to support static tracepoints, see
1896 the "New remote packets" section below.
1898 * Better reconstruction of tracepoints after disconnected tracing
1900 GDB will attempt to download the original source form of tracepoint
1901 definitions when starting a trace run, and then will upload these
1902 upon reconnection to the target, resulting in a more accurate
1903 reconstruction of the tracepoints that are in use on the target.
1907 You can now exercise direct control over the ways that GDB can
1908 affect your program. For instance, you can disallow the setting of
1909 breakpoints, so that the program can run continuously (assuming
1910 non-stop mode). In addition, the "observer" variable is available
1911 to switch all of the different controls; in observer mode, GDB
1912 cannot affect the target's behavior at all, which is useful for
1913 tasks like diagnosing live systems in the field.
1915 * The new convenience variable $_thread holds the number of the
1918 * New remote packets
1922 Return the address of the Windows Thread Information Block of a given thread.
1926 In response to several of the tracepoint packets, the target may now
1927 also respond with a number of intermediate `qRelocInsn' request
1928 packets before the final result packet, to have GDB handle
1929 relocating an instruction to execute at a different address. This
1930 is particularly useful for stubs that support fast tracepoints. GDB
1931 reports support for this feature in the qSupported packet.
1935 List static tracepoint markers in the target program.
1939 List static tracepoint markers at a given address in the target
1942 qXfer:statictrace:read
1944 Read the static trace data collected (by a `collect $_sdata'
1945 tracepoint action). The remote stub reports support for this packet
1946 to gdb's qSupported query.
1950 Send the current settings of GDB's permission flags.
1954 Send part of the source (textual) form of a tracepoint definition,
1955 which includes location, conditional, and action list.
1957 * The source command now accepts a -s option to force searching for the
1958 script in the source search path even if the script name specifies
1961 * New features in the GDB remote stub, GDBserver
1963 - GDBserver now support tracepoints (including fast tracepoints, and
1964 static tracepoints). The feature is currently supported by the
1965 i386-linux and amd64-linux builds. See the "Tracepoints support
1966 in gdbserver" section in the manual for more information.
1968 GDBserver JIT compiles the tracepoint's conditional agent
1969 expression bytecode into native code whenever possible for low
1970 overhead dynamic tracepoints conditionals. For such tracepoints,
1971 an expression that examines program state is evaluated when the
1972 tracepoint is reached, in order to determine whether to capture
1973 trace data. If the condition is simple and false, processing the
1974 tracepoint finishes very quickly and no data is gathered.
1976 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1977 for static tracepoints support.
1979 - GDBserver now supports x86_64 Windows 64-bit debugging.
1981 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1982 it understands register description.
1984 * The --batch flag now disables pagination and queries.
1986 * X86 general purpose registers
1988 GDB now supports reading/writing byte, word and double-word x86
1989 general purpose registers directly. This means you can use, say,
1990 $ah or $ax to refer, respectively, to the byte register AH and
1991 16-bit word register AX that are actually portions of the 32-bit
1992 register EAX or 64-bit register RAX.
1994 * The `commands' command now accepts a range of breakpoints to modify.
1995 A plain `commands' following a command that creates multiple
1996 breakpoints affects all the breakpoints set by that command. This
1997 applies to breakpoints set by `rbreak', and also applies when a
1998 single `break' command creates multiple breakpoints (e.g.,
1999 breakpoints on overloaded c++ functions).
2001 * The `rbreak' command now accepts a filename specification as part of
2002 its argument, limiting the functions selected by the regex to those
2003 in the specified file.
2005 * Support for remote debugging Windows and SymbianOS shared libraries
2006 from Unix hosts has been improved. Non Windows GDB builds now can
2007 understand target reported file names that follow MS-DOS based file
2008 system semantics, such as file names that include drive letters and
2009 use the backslash character as directory separator. This makes it
2010 possible to transparently use the "set sysroot" and "set
2011 solib-search-path" on Unix hosts to point as host copies of the
2012 target's shared libraries. See the new command "set
2013 target-file-system-kind" described below, and the "Commands to
2014 specify files" section in the user manual for more information.
2018 eval template, expressions...
2019 Convert the values of one or more expressions under the control
2020 of the string template to a command line, and call it.
2022 set target-file-system-kind unix|dos-based|auto
2023 show target-file-system-kind
2024 Set or show the assumed file system kind for target reported file
2027 save breakpoints <filename>
2028 Save all current breakpoint definitions to a file suitable for use
2029 in a later debugging session. To read the saved breakpoint
2030 definitions, use the `source' command.
2032 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2035 info static-tracepoint-markers
2036 Display information about static tracepoint markers in the target.
2038 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2039 Define a static tracepoint by probing a marker at the given
2040 function, line, address, or marker ID.
2044 Enable and disable observer mode.
2046 set may-write-registers on|off
2047 set may-write-memory on|off
2048 set may-insert-breakpoints on|off
2049 set may-insert-tracepoints on|off
2050 set may-insert-fast-tracepoints on|off
2051 set may-interrupt on|off
2052 Set individual permissions for GDB effects on the target. Note that
2053 some of these settings can have undesirable or surprising
2054 consequences, particularly when changed in the middle of a session.
2055 For instance, disabling the writing of memory can prevent
2056 breakpoints from being inserted, cause single-stepping to fail, or
2057 even crash your program, if you disable after breakpoints have been
2058 inserted. However, GDB should not crash.
2060 set record memory-query on|off
2061 show record memory-query
2062 Control whether to stop the inferior if memory changes caused
2063 by an instruction cannot be recorded.
2068 The disassemble command now supports "start,+length" form of two arguments.
2072 ** GDB now provides a new directory location, called the python directory,
2073 where Python scripts written for GDB can be installed. The location
2074 of that directory is <data-directory>/python, where <data-directory>
2075 is the GDB data directory. For more details, see section `Scripting
2076 GDB using Python' in the manual.
2078 ** The GDB Python API now has access to breakpoints, symbols, symbol
2079 tables, program spaces, inferiors, threads and frame's code blocks.
2080 Additionally, GDB Parameters can now be created from the API, and
2081 manipulated via set/show in the CLI.
2083 ** New functions gdb.target_charset, gdb.target_wide_charset,
2084 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2086 ** New exception gdb.GdbError.
2088 ** Pretty-printers are now also looked up in the current program space.
2090 ** Pretty-printers can now be individually enabled and disabled.
2092 ** GDB now looks for names of Python scripts to auto-load in a
2093 special section named `.debug_gdb_scripts', in addition to looking
2094 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2096 * Tracepoint actions were unified with breakpoint commands. In particular,
2097 there are no longer differences in "info break" output for breakpoints and
2098 tracepoints and the "commands" command can be used for both tracepoints and
2099 regular breakpoints.
2103 ARM Symbian arm*-*-symbianelf*
2105 * D language support.
2106 GDB now supports debugging programs written in the D programming
2109 * GDB now supports the extended ptrace interface for PowerPC which is
2110 available since Linux kernel version 2.6.34. This automatically enables
2111 any hardware breakpoints and additional hardware watchpoints available in
2112 the processor. The old ptrace interface exposes just one hardware
2113 watchpoint and no hardware breakpoints.
2115 * GDB is now able to use the Data Value Compare (DVC) register available on
2116 embedded PowerPC processors to implement in hardware simple watchpoint
2117 conditions of the form:
2119 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2121 This works in native GDB running on Linux kernels with the extended ptrace
2122 interface mentioned above.
2124 *** Changes in GDB 7.1
2128 ** Namespace Support
2130 GDB now supports importing of namespaces in C++. This enables the
2131 user to inspect variables from imported namespaces. Support for
2132 namepace aliasing has also been added. So, if a namespace is
2133 aliased in the current scope (e.g. namepace C=A; ) the user can
2134 print variables using the alias (e.g. (gdb) print C::x).
2138 All known bugs relating to the printing of virtual base class were
2139 fixed. It is now possible to call overloaded static methods using a
2144 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2145 and reinterpret_cast<> are now handled by the C++ expression parser.
2149 Xilinx MicroBlaze microblaze-*-*
2154 Xilinx MicroBlaze microblaze
2157 * Multi-program debugging.
2159 GDB now has support for multi-program (a.k.a. multi-executable or
2160 multi-exec) debugging. This allows for debugging multiple inferiors
2161 simultaneously each running a different program under the same GDB
2162 session. See "Debugging Multiple Inferiors and Programs" in the
2163 manual for more information. This implied some user visible changes
2164 in the multi-inferior support. For example, "info inferiors" now
2165 lists inferiors that are not running yet or that have exited
2166 already. See also "New commands" and "New options" below.
2168 * New tracing features
2170 GDB's tracepoint facility now includes several new features:
2172 ** Trace state variables
2174 GDB tracepoints now include support for trace state variables, which
2175 are variables managed by the target agent during a tracing
2176 experiment. They are useful for tracepoints that trigger each
2177 other, so for instance one tracepoint can count hits in a variable,
2178 and then a second tracepoint has a condition that is true when the
2179 count reaches a particular value. Trace state variables share the
2180 $-syntax of GDB convenience variables, and can appear in both
2181 tracepoint actions and condition expressions. Use the "tvariable"
2182 command to create, and "info tvariables" to view; see "Trace State
2183 Variables" in the manual for more detail.
2187 GDB now includes an option for defining fast tracepoints, which
2188 targets may implement more efficiently, such as by installing a jump
2189 into the target agent rather than a trap instruction. The resulting
2190 speedup can be by two orders of magnitude or more, although the
2191 tradeoff is that some program locations on some target architectures
2192 might not allow fast tracepoint installation, for instance if the
2193 instruction to be replaced is shorter than the jump. To request a
2194 fast tracepoint, use the "ftrace" command, with syntax identical to
2195 the regular trace command.
2197 ** Disconnected tracing
2199 It is now possible to detach GDB from the target while it is running
2200 a trace experiment, then reconnect later to see how the experiment
2201 is going. In addition, a new variable disconnected-tracing lets you
2202 tell the target agent whether to continue running a trace if the
2203 connection is lost unexpectedly.
2207 GDB now has the ability to save the trace buffer into a file, and
2208 then use that file as a target, similarly to you can do with
2209 corefiles. You can select trace frames, print data that was
2210 collected in them, and use tstatus to display the state of the
2211 tracing run at the moment that it was saved. To create a trace
2212 file, use "tsave <filename>", and to use it, do "target tfile
2215 ** Circular trace buffer
2217 You can ask the target agent to handle the trace buffer as a
2218 circular buffer, discarding the oldest trace frames to make room for
2219 newer ones, by setting circular-trace-buffer to on. This feature may
2220 not be available for all target agents.
2225 The disassemble command, when invoked with two arguments, now requires
2226 the arguments to be comma-separated.
2229 The info variables command now displays variable definitions. Files
2230 which only declare a variable are not shown.
2233 The source command is now capable of sourcing Python scripts.
2234 This feature is dependent on the debugger being build with Python
2237 Related to this enhancement is also the introduction of a new command
2238 "set script-extension" (see below).
2240 * New commands (for set/show, see "New options" below)
2242 record save [<FILENAME>]
2243 Save a file (in core file format) containing the process record
2244 execution log for replay debugging at a later time.
2246 record restore <FILENAME>
2247 Restore the process record execution log that was saved at an
2248 earlier time, for replay debugging.
2250 add-inferior [-copies <N>] [-exec <FILENAME>]
2253 clone-inferior [-copies <N>] [ID]
2254 Make a new inferior ready to execute the same program another
2255 inferior has loaded.
2260 maint info program-spaces
2261 List the program spaces loaded into GDB.
2263 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2264 show remote interrupt-sequence
2265 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2266 as the sequence to the remote target in order to interrupt the execution.
2267 Ctrl-C is a default. Some system prefers BREAK which is high level of
2268 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2269 Magic SysRq g. It is BREAK signal and character 'g'.
2271 set remote interrupt-on-connect [on | off]
2272 show remote interrupt-on-connect
2273 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2274 remote target when gdb connects to it. This is needed when you debug
2277 set remotebreak [on | off]
2279 Deprecated. Use "set/show remote interrupt-sequence" instead.
2281 tvariable $NAME [ = EXP ]
2282 Create or modify a trace state variable.
2285 List trace state variables and their values.
2287 delete tvariable $NAME ...
2288 Delete one or more trace state variables.
2291 Evaluate the given expressions without collecting anything into the
2292 trace buffer. (Valid in tracepoint actions only.)
2294 ftrace FN / FILE:LINE / *ADDR
2295 Define a fast tracepoint at the given function, line, or address.
2297 * New expression syntax
2299 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2300 GDB now parses 0b101010 identically with 42.
2304 set follow-exec-mode new|same
2305 show follow-exec-mode
2306 Control whether GDB reuses the same inferior across an exec call or
2307 creates a new one. This is useful to be able to restart the old
2308 executable after the inferior having done an exec call.
2310 set default-collect EXPR, ...
2311 show default-collect
2312 Define a list of expressions to be collected at each tracepoint.
2313 This is a useful way to ensure essential items are not overlooked,
2314 such as registers or a critical global variable.
2316 set disconnected-tracing
2317 show disconnected-tracing
2318 If set to 1, the target is instructed to continue tracing if it
2319 loses its connection to GDB. If 0, the target is to stop tracing
2322 set circular-trace-buffer
2323 show circular-trace-buffer
2324 If set to on, the target is instructed to use a circular trace buffer
2325 and discard the oldest trace frames instead of stopping the trace due
2326 to a full trace buffer. If set to off, the trace stops when the buffer
2327 fills up. Some targets may not support this.
2329 set script-extension off|soft|strict
2330 show script-extension
2331 If set to "off", the debugger does not perform any script language
2332 recognition, and all sourced files are assumed to be GDB scripts.
2333 If set to "soft" (the default), files are sourced according to
2334 filename extension, falling back to GDB scripts if the first
2336 If set to "strict", files are sourced according to filename extension.
2338 set ada trust-PAD-over-XVS on|off
2339 show ada trust-PAD-over-XVS
2340 If off, activate a workaround against a bug in the debugging information
2341 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2342 the GCC sources for more information about the GNAT encoding and
2343 PAD types in particular). It is always safe to set this option to
2344 off, but this introduces a slight performance penalty. The default
2347 * Python API Improvements
2349 ** GDB provides the new class gdb.LazyString. This is useful in
2350 some pretty-printing cases. The new method gdb.Value.lazy_string
2351 provides a simple way to create objects of this type.
2353 ** The fields returned by gdb.Type.fields now have an
2354 `is_base_class' attribute.
2356 ** The new method gdb.Type.range returns the range of an array type.
2358 ** The new method gdb.parse_and_eval can be used to parse and
2359 evaluate an expression.
2361 * New remote packets
2364 Define a trace state variable.
2367 Get the current value of a trace state variable.
2370 Set desired tracing behavior upon disconnection.
2373 Set the trace buffer to be linear or circular.
2376 Get data about the tracepoints currently in use.
2380 Process record now works correctly with hardware watchpoints.
2382 Multiple bug fixes have been made to the mips-irix port, making it
2383 much more reliable. In particular:
2384 - Debugging threaded applications is now possible again. Previously,
2385 GDB would hang while starting the program, or while waiting for
2386 the program to stop at a breakpoint.
2387 - Attaching to a running process no longer hangs.
2388 - An error occurring while loading a core file has been fixed.
2389 - Changing the value of the PC register now works again. This fixes
2390 problems observed when using the "jump" command, or when calling
2391 a function from GDB, or even when assigning a new value to $pc.
2392 - With the "finish" and "return" commands, the return value for functions
2393 returning a small array is now correctly printed.
2394 - It is now possible to break on shared library code which gets executed
2395 during a shared library init phase (code executed while executing
2396 their .init section). Previously, the breakpoint would have no effect.
2397 - GDB is now able to backtrace through the signal handler for
2398 non-threaded programs.
2400 PIE (Position Independent Executable) programs debugging is now supported.
2401 This includes debugging execution of PIC (Position Independent Code) shared
2402 libraries although for that, it should be possible to run such libraries as an
2405 *** Changes in GDB 7.0
2407 * GDB now has an interface for JIT compilation. Applications that
2408 dynamically generate code can create symbol files in memory and register
2409 them with GDB. For users, the feature should work transparently, and
2410 for JIT developers, the interface is documented in the GDB manual in the
2411 "JIT Compilation Interface" chapter.
2413 * Tracepoints may now be conditional. The syntax is as for
2414 breakpoints; either an "if" clause appended to the "trace" command,
2415 or the "condition" command is available. GDB sends the condition to
2416 the target for evaluation using the same bytecode format as is used
2417 for tracepoint actions.
2419 * The disassemble command now supports: an optional /r modifier, print the
2420 raw instructions in hex as well as in symbolic form, and an optional /m
2421 modifier to print mixed source+assembly.
2423 * Process record and replay
2425 In a architecture environment that supports ``process record and
2426 replay'', ``process record and replay'' target can record a log of
2427 the process execution, and replay it with both forward and reverse
2430 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2431 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2432 set execution-direction {forward|reverse}, for targets that support
2435 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2436 feature is available with a native GDB running on kernel version
2439 * GDB now has support for multi-byte and wide character sets on the
2440 target. Strings whose character type is wchar_t, char16_t, or
2441 char32_t are now correctly printed. GDB supports wide- and unicode-
2442 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2443 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2444 `printf'. This feature requires iconv to work properly; if your
2445 system does not have a working iconv, GDB can use GNU libiconv. See
2446 the installation instructions for more information.
2448 * GDB now supports automatic retrieval of shared library files from
2449 remote targets. To use this feature, specify a system root that begins
2450 with the `remote:' prefix, either via the `set sysroot' command or via
2451 the `--with-sysroot' configure-time option.
2453 * "info sharedlibrary" now takes an optional regex of libraries to show,
2454 and it now reports if a shared library has no debugging information.
2456 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2457 now complete on file names.
2459 * When completing in expressions, gdb will attempt to limit
2460 completions to allowable structure or union fields, where appropriate.
2461 For instance, consider:
2463 # struct example { int f1; double f2; };
2464 # struct example variable;
2467 If the user types TAB at the end of this command line, the available
2468 completions will be "f1" and "f2".
2470 * Inlined functions are now supported. They show up in backtraces, and
2471 the "step", "next", and "finish" commands handle them automatically.
2473 * GDB now supports the token-splicing (##) and stringification (#)
2474 operators when expanding macros. It also supports variable-arity
2477 * GDB now supports inspecting extra signal information, exported by
2478 the new $_siginfo convenience variable. The feature is currently
2479 implemented on linux ARM, i386 and amd64.
2481 * GDB can now display the VFP floating point registers and NEON vector
2482 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2483 can provide these registers (requires Linux 2.6.30 or later). Remote
2484 and simulator targets may also provide them.
2486 * New remote packets
2489 Search memory for a sequence of bytes.
2492 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2493 operation over reliable transport links. Use of this packet is
2494 controlled by the `set remote noack-packet' command.
2497 Kill the process with the specified process ID. Use this in preference
2498 to `k' when multiprocess protocol extensions are supported.
2501 Obtains additional operating system information
2505 Read or write additional signal information.
2507 * Removed remote protocol undocumented extension
2509 An undocumented extension to the remote protocol's `S' stop reply
2510 packet that permited the stub to pass a process id was removed.
2511 Remote servers should use the `T' stop reply packet instead.
2513 * GDB now supports multiple function calling conventions according to the
2514 DWARF-2 DW_AT_calling_convention function attribute.
2516 * The SH target utilizes the aforementioned change to distinguish between gcc
2517 and Renesas calling convention. It also adds the new CLI commands
2518 `set/show sh calling-convention'.
2520 * GDB can now read compressed debug sections, as produced by GNU gold
2521 with the --compress-debug-sections=zlib flag.
2523 * 64-bit core files are now supported on AIX.
2525 * Thread switching is now supported on Tru64.
2527 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2528 which will be allocated using malloc later in program execution.
2530 * The qXfer:libraries:read remote procotol packet now allows passing a
2531 list of section offsets.
2533 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2534 conditions handling signals delivered during attach or thread creation
2535 have also been fixed.
2537 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2538 From the user's standpoint, all unqualified instances of True and False
2539 are treated as the standard definitions, regardless of context.
2541 * GDB now parses C++ symbol and type names more flexibly. For
2544 template<typename T> class C { };
2547 GDB will now correctly handle all of:
2549 ptype C<char const *>
2550 ptype C<char const*>
2551 ptype C<const char *>
2552 ptype C<const char*>
2554 * New features in the GDB remote stub, gdbserver
2556 - The "--wrapper" command-line argument tells gdbserver to use a
2557 wrapper program to launch programs for debugging.
2559 - On PowerPC and S/390 targets, it is now possible to use a single
2560 gdbserver executable to debug both 32-bit and 64-bit programs.
2561 (This requires gdbserver itself to be built as a 64-bit executable.)
2563 - gdbserver uses the new noack protocol mode for TCP connections to
2564 reduce communications latency, if also supported and enabled in GDB.
2566 - Support for the sparc64-linux-gnu target is now included in
2569 - The amd64-linux build of gdbserver now supports debugging both
2570 32-bit and 64-bit programs.
2572 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2573 now support hardware watchpoints, and will use them automatically
2578 GDB now has support for scripting using Python. Whether this is
2579 available is determined at configure time.
2581 New GDB commands can now be written in Python.
2583 * Ada tasking support
2585 Ada tasks can now be inspected in GDB. The following commands have
2589 Print the list of Ada tasks.
2591 Print detailed information about task number N.
2593 Print the task number of the current task.
2595 Switch the context of debugging to task number N.
2597 * Support for user-defined prefixed commands. The "define" command can
2598 add new commands to existing prefixes, e.g. "target".
2600 * Multi-inferior, multi-process debugging.
2602 GDB now has generalized support for multi-inferior debugging. See
2603 "Debugging Multiple Inferiors" in the manual for more information.
2604 Although availability still depends on target support, the command
2605 set is more uniform now. The GNU/Linux specific multi-forks support
2606 has been migrated to this new framework. This implied some user
2607 visible changes; see "New commands" and also "Removed commands"
2610 * Target descriptions can now describe the target OS ABI. See the
2611 "Target Description Format" section in the user manual for more
2614 * Target descriptions can now describe "compatible" architectures
2615 to indicate that the target can execute applications for a different
2616 architecture in addition to those for the main target architecture.
2617 See the "Target Description Format" section in the user manual for
2620 * Multi-architecture debugging.
2622 GDB now includes general supports for debugging applications on
2623 hybrid systems that use more than one single processor architecture
2624 at the same time. Each such hybrid architecture still requires
2625 specific support to be added. The only hybrid architecture supported
2626 in this version of GDB is the Cell Broadband Engine.
2628 * GDB now supports integrated debugging of Cell/B.E. applications that
2629 use both the PPU and SPU architectures. To enable support for hybrid
2630 Cell/B.E. debugging, you need to configure GDB to support both the
2631 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2632 --enable-targets configure option.
2634 * Non-stop mode debugging.
2636 For some targets, GDB now supports an optional mode of operation in
2637 which you can examine stopped threads while other threads continue
2638 to execute freely. This is referred to as non-stop mode, with the
2639 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2640 section in the user manual for more information.
2642 To be able to support remote non-stop debugging, a remote stub needs
2643 to implement the non-stop mode remote protocol extensions, as
2644 described in the "Remote Non-Stop" section of the user manual. The
2645 GDB remote stub, gdbserver, has been adjusted to support these
2646 extensions on linux targets.
2648 * New commands (for set/show, see "New options" below)
2650 catch syscall [NAME(S) | NUMBER(S)]
2651 Catch system calls. Arguments, which should be names of system
2652 calls or their numbers, mean catch only those syscalls. Without
2653 arguments, every syscall will be caught. When the inferior issues
2654 any of the specified syscalls, GDB will stop and announce the system
2655 call, both when it is called and when its call returns. This
2656 feature is currently available with a native GDB running on the
2657 Linux Kernel, under the following architectures: x86, x86_64,
2658 PowerPC and PowerPC64.
2660 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2662 Search memory for a sequence of bytes.
2664 maint set python print-stack
2665 maint show python print-stack
2666 Show a stack trace when an error is encountered in a Python script.
2669 Invoke CODE by passing it to the Python interpreter.
2674 These allow macros to be defined, undefined, and listed
2678 Show operating system information about processes.
2681 List the inferiors currently under GDB's control.
2684 Switch focus to inferior number NUM.
2687 Detach from inferior number NUM.
2690 Kill inferior number NUM.
2694 set spu stop-on-load
2695 show spu stop-on-load
2696 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2698 set spu auto-flush-cache
2699 show spu auto-flush-cache
2700 Control whether to automatically flush the software-managed cache
2701 during Cell/B.E. debugging.
2703 set sh calling-convention
2704 show sh calling-convention
2705 Control the calling convention used when calling SH target functions.
2708 show debug timestamp
2709 Control display of timestamps with GDB debugging output.
2711 set disassemble-next-line
2712 show disassemble-next-line
2713 Control display of disassembled source lines or instructions when
2716 set remote noack-packet
2717 show remote noack-packet
2718 Set/show the use of remote protocol QStartNoAckMode packet. See above
2719 under "New remote packets."
2721 set remote query-attached-packet
2722 show remote query-attached-packet
2723 Control use of remote protocol `qAttached' (query-attached) packet.
2725 set remote read-siginfo-object
2726 show remote read-siginfo-object
2727 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2730 set remote write-siginfo-object
2731 show remote write-siginfo-object
2732 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2735 set remote reverse-continue
2736 show remote reverse-continue
2737 Control use of remote protocol 'bc' (reverse-continue) packet.
2739 set remote reverse-step
2740 show remote reverse-step
2741 Control use of remote protocol 'bs' (reverse-step) packet.
2743 set displaced-stepping
2744 show displaced-stepping
2745 Control displaced stepping mode. Displaced stepping is a way to
2746 single-step over breakpoints without removing them from the debuggee.
2747 Also known as "out-of-line single-stepping".
2750 show debug displaced
2751 Control display of debugging info for displaced stepping.
2753 maint set internal-error
2754 maint show internal-error
2755 Control what GDB does when an internal error is detected.
2757 maint set internal-warning
2758 maint show internal-warning
2759 Control what GDB does when an internal warning is detected.
2764 Use a wrapper program to launch programs for debugging.
2766 set multiple-symbols (all|ask|cancel)
2767 show multiple-symbols
2768 The value of this variable can be changed to adjust the debugger behavior
2769 when an expression or a breakpoint location contains an ambiguous symbol
2770 name (an overloaded function name, for instance).
2772 set breakpoint always-inserted
2773 show breakpoint always-inserted
2774 Keep breakpoints always inserted in the target, as opposed to inserting
2775 them when resuming the target, and removing them when the target stops.
2776 This option can improve debugger performance on slow remote targets.
2778 set arm fallback-mode (arm|thumb|auto)
2779 show arm fallback-mode
2780 set arm force-mode (arm|thumb|auto)
2782 These commands control how ARM GDB determines whether instructions
2783 are ARM or Thumb. The default for both settings is auto, which uses
2784 the current CPSR value for instructions without symbols; previous
2785 versions of GDB behaved as if "set arm fallback-mode arm".
2787 set disable-randomization
2788 show disable-randomization
2789 Standalone programs run with the virtual address space randomization enabled
2790 by default on some platforms. This option keeps the addresses stable across
2791 multiple debugging sessions.
2795 Control whether other threads are stopped or not when some thread hits
2800 Requests that asynchronous execution is enabled in the target, if available.
2801 In this case, it's possible to resume target in the background, and interact
2802 with GDB while the target is running. "show target-async" displays the
2803 current state of asynchronous execution of the target.
2805 set target-wide-charset
2806 show target-wide-charset
2807 The target-wide-charset is the name of the character set that GDB
2808 uses when printing characters whose type is wchar_t.
2810 set tcp auto-retry (on|off)
2812 set tcp connect-timeout
2813 show tcp connect-timeout
2814 These commands allow GDB to retry failed TCP connections to a remote stub
2815 with a specified timeout period; this is useful if the stub is launched
2816 in parallel with GDB but may not be ready to accept connections immediately.
2818 set libthread-db-search-path
2819 show libthread-db-search-path
2820 Control list of directories which GDB will search for appropriate
2823 set schedule-multiple (on|off)
2824 show schedule-multiple
2825 Allow GDB to resume all threads of all processes or only threads of
2826 the current process.
2830 Use more aggressive caching for accesses to the stack. This improves
2831 performance of remote debugging (particularly backtraces) without
2832 affecting correctness.
2834 set interactive-mode (on|off|auto)
2835 show interactive-mode
2836 Control whether GDB runs in interactive mode (on) or not (off).
2837 When in interactive mode, GDB waits for the user to answer all
2838 queries. Otherwise, GDB does not wait and assumes the default
2839 answer. When set to auto (the default), GDB determines which
2840 mode to use based on the stdin settings.
2845 For program forks, this is replaced by the new more generic `info
2846 inferiors' command. To list checkpoints, you can still use the
2847 `info checkpoints' command, which was an alias for the `info forks'
2851 Replaced by the new `inferior' command. To switch between
2852 checkpoints, you can still use the `restart' command, which was an
2853 alias for the `fork' command.
2856 This is removed, since some targets don't have a notion of
2857 processes. To switch between processes, you can still use the
2858 `inferior' command using GDB's own inferior number.
2861 For program forks, this is replaced by the new more generic `kill
2862 inferior' command. To delete a checkpoint, you can still use the
2863 `delete checkpoint' command, which was an alias for the `delete
2867 For program forks, this is replaced by the new more generic `detach
2868 inferior' command. To detach a checkpoint, you can still use the
2869 `detach checkpoint' command, which was an alias for the `detach
2872 * New native configurations
2874 x86/x86_64 Darwin i[34567]86-*-darwin*
2876 x86_64 MinGW x86_64-*-mingw*
2880 Lattice Mico32 lm32-*
2881 x86 DICOS i[34567]86-*-dicos*
2882 x86_64 DICOS x86_64-*-dicos*
2885 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2886 (mingw32ce) debugging.
2892 These commands were actually not implemented on any target.
2894 *** Changes in GDB 6.8
2896 * New native configurations
2898 NetBSD/hppa hppa*-*netbsd*
2899 Xtensa GNU/Linux xtensa*-*-linux*
2903 NetBSD/hppa hppa*-*-netbsd*
2904 Xtensa GNU/Lunux xtensa*-*-linux*
2906 * Change in command line behavior -- corefiles vs. process ids.
2908 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2909 attaching to process NUMBER fails, GDB no longer attempts to open a
2910 core file named NUMBER. Attaching to a program using the -c option
2911 is no longer supported. Instead, use the '-p' or '--pid' options.
2913 * GDB can now be built as a native debugger for debugging Windows x86
2914 (mingw32) Portable Executable (PE) programs.
2916 * Pending breakpoints no longer change their number when their address
2919 * GDB now supports breakpoints with multiple locations,
2920 including breakpoints on C++ constructors, inside C++ templates,
2921 and in inlined functions.
2923 * GDB's ability to debug optimized code has been improved. GDB more
2924 accurately identifies function bodies and lexical blocks that occupy
2925 more than one contiguous range of addresses.
2927 * Target descriptions can now describe registers for PowerPC.
2929 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2930 registers on PowerPC targets.
2932 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2933 targets even when the libthread_db library is not available.
2935 * The GDB remote stub, gdbserver, now supports the new file transfer
2936 commands (remote put, remote get, and remote delete).
2938 * The GDB remote stub, gdbserver, now supports run and attach in
2939 extended-remote mode.
2941 * hppa*64*-*-hpux11* target broken
2942 The debugger is unable to start a program and fails with the following
2943 error: "Error trying to get information about dynamic linker".
2944 The gdb-6.7 release is also affected.
2946 * GDB now supports the --enable-targets= configure option to allow
2947 building a single GDB executable that supports multiple remote
2948 target architectures.
2950 * GDB now supports debugging C and C++ programs which use the
2951 Decimal Floating Point extension. In addition, the PowerPC target
2952 now has a set of pseudo-registers to inspect decimal float values
2953 stored in two consecutive float registers.
2955 * The -break-insert MI command can optionally create pending
2958 * Improved support for debugging Ada
2959 Many improvements to the Ada language support have been made. These
2961 - Better support for Ada2005 interface types
2962 - Improved handling of arrays and slices in general
2963 - Better support for Taft-amendment types
2964 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2966 - Improved command completion in Ada
2969 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2974 set print frame-arguments (all|scalars|none)
2975 show print frame-arguments
2976 The value of this variable can be changed to control which argument
2977 values should be printed by the debugger when displaying a frame.
2982 Transfer files to and from a remote target, and delete remote files.
2989 Transfer files to and from a remote target, and delete remote files.
2991 * New remote packets
2998 Open, close, read, write, and delete files on the remote system.
3001 Attach to an existing process on the remote system, in extended-remote
3005 Run a new process on the remote system, in extended-remote mode.
3007 *** Changes in GDB 6.7
3009 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3010 bfd, libiberty and opcodes, as revealed by static analysis donated by
3011 Coverity, Inc. (http://scan.coverity.com).
3013 * When looking up multiply-defined global symbols, GDB will now prefer the
3014 symbol definition in the current shared library if it was built using the
3015 -Bsymbolic linker option.
3017 * When the Text User Interface (TUI) is not configured, GDB will now
3018 recognize the -tui command-line option and print a message that the TUI
3021 * The GDB remote stub, gdbserver, now has lower overhead for high
3022 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3024 * GDB for MIPS targets now autodetects whether a remote target provides
3025 32-bit or 64-bit register values.
3027 * Support for C++ member pointers has been improved.
3029 * GDB now understands XML target descriptions, which specify the
3030 target's overall architecture. GDB can read a description from
3031 a local file or over the remote serial protocol.
3033 * Vectors of single-byte data use a new integer type which is not
3034 automatically displayed as character or string data.
3036 * The /s format now works with the print command. It displays
3037 arrays of single-byte integers and pointers to single-byte integers
3040 * Target descriptions can now describe target-specific registers,
3041 for architectures which have implemented the support (currently
3042 only ARM, M68K, and MIPS).
3044 * GDB and the GDB remote stub, gdbserver, now support the XScale
3047 * The GDB remote stub, gdbserver, has been updated to support
3048 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3049 has been rewritten to use the standard GDB remote protocol.
3051 * GDB can now step into C++ functions which are called through thunks.
3053 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3055 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3056 layout. It also supports a TextSeg= and DataSeg= response when only
3057 segment base addresses (rather than offsets) are available.
3059 * The /i format now outputs any trailing branch delay slot instructions
3060 immediately following the last instruction within the count specified.
3062 * The GDB remote protocol "T" stop reply packet now supports a
3063 "library" response. Combined with the new "qXfer:libraries:read"
3064 packet, this response allows GDB to debug shared libraries on targets
3065 where the operating system manages the list of loaded libraries (e.g.
3066 Windows and SymbianOS).
3068 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3069 (DLLs) on Windows and Windows CE targets.
3071 * GDB now supports a faster verification that a .debug file matches its binary
3072 according to its build-id signature, if the signature is present.
3078 Enable or disable hardware flow control (RTS/CTS) on the serial port
3079 when debugging using remote targets.
3081 set mem inaccessible-by-default
3082 show mem inaccessible-by-default
3083 If the target supplies a memory map, for instance via the remote
3084 protocol's "qXfer:memory-map:read" packet, setting this variable
3085 prevents GDB from accessing memory outside the memory map. This
3086 is useful for targets with memory mapped registers or which react
3087 badly to accesses of unmapped address space.
3089 set breakpoint auto-hw
3090 show breakpoint auto-hw
3091 If the target supplies a memory map, for instance via the remote
3092 protocol's "qXfer:memory-map:read" packet, setting this variable
3093 lets GDB use hardware breakpoints automatically for memory regions
3094 where it can not use software breakpoints. This covers both the
3095 "break" command and internal breakpoints used for other commands
3096 including "next" and "finish".
3099 catch exception unhandled
3100 Stop the program execution when Ada exceptions are raised.
3103 Stop the program execution when an Ada assertion failed.
3107 Set an alternate system root for target files. This is a more
3108 general version of "set solib-absolute-prefix", which is now
3109 an alias to "set sysroot".
3112 Provide extended SPU facility status information. This set of
3113 commands is available only when debugging the Cell/B.E. SPU
3116 * New native configurations
3118 OpenBSD/sh sh*-*openbsd*
3121 unset tdesc filename
3123 Use the specified local file as an XML target description, and do
3124 not query the target for its built-in description.
3128 OpenBSD/sh sh*-*-openbsd*
3129 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3130 Toshiba Media Processor mep-elf
3132 * New remote packets
3135 Ignore the specified signals; pass them directly to the debugged program
3136 without stopping other threads or reporting them to GDB.
3138 qXfer:features:read:
3139 Read an XML target description from the target, which describes its
3144 Read or write contents of an spufs file on the target system. These
3145 packets are available only on the Cell/B.E. SPU architecture.
3147 qXfer:libraries:read:
3148 Report the loaded shared libraries. Combined with new "T" packet
3149 response, this packet allows GDB to debug shared libraries on
3150 targets where the operating system manages the list of loaded
3151 libraries (e.g. Windows and SymbianOS).
3155 Support for these obsolete configurations has been removed.
3163 i[34567]86-*-lynxos*
3164 i[34567]86-*-netware*
3165 i[34567]86-*-sco3.2v5*
3166 i[34567]86-*-sco3.2v4*
3168 i[34567]86-*-sysv4.2*
3171 i[34567]86-*-unixware2*
3172 i[34567]86-*-unixware*
3181 * Other removed features
3188 Various m68k-only ROM monitors.
3195 Various Renesas ROM monitors and debugging interfaces for SH and
3200 Support for a Macraigor serial interface to on-chip debugging.
3201 GDB does not directly support the newer parallel or USB
3206 A debug information format. The predecessor to DWARF 2 and
3207 DWARF 3, which are still supported.
3209 Support for the HP aCC compiler on HP-UX/PA-RISC
3211 SOM-encapsulated symbolic debugging information, automatic
3212 invocation of pxdb, and the aCC custom C++ ABI. This does not
3213 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3214 with aCC can still be debugged on an assembly level.
3216 MIPS ".pdr" sections
3218 A MIPS-specific format used to describe stack frame layout
3219 in debugging information.
3223 GDB could work with an older version of Guile to debug
3224 the interpreter and Scheme programs running in it.
3226 set mips stack-arg-size
3227 set mips saved-gpreg-size
3229 Use "set mips abi" to control parameter passing for MIPS.
3231 *** Changes in GDB 6.6
3236 Cell Broadband Engine SPU spu-elf
3238 * GDB can now be configured as a cross-debugger targeting native Windows
3239 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3240 running on a Windows system over TCP/IP to debug Windows programs.
3242 * The GDB remote stub, gdbserver, has been updated to support Windows and
3243 Cygwin debugging. Both single-threaded and multi-threaded programs are
3246 * The "set trust-readonly-sections" command works again. This command was
3247 broken in GDB 6.3, 6.4, and 6.5.
3249 * The "load" command now supports writing to flash memory, if the remote
3250 stub provides the required support.
3252 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3253 longer requires symbolic debug information (e.g. DWARF-2).
3258 unset substitute-path
3259 show substitute-path
3260 Manage a list of substitution rules that GDB uses to rewrite the name
3261 of the directories where the sources are located. This can be useful
3262 for instance when the sources were moved to a different location
3263 between compilation and debugging.
3267 Print each CLI command as it is executed. Each command is prefixed with
3268 a number of `+' symbols representing the nesting depth.
3269 The source command now has a `-v' option to enable the same feature.
3273 The ARM Demon monitor support (RDP protocol, "target rdp").
3275 Kernel Object Display, an embedded debugging feature which only worked with
3276 an obsolete version of Cisco IOS.
3278 The 'set download-write-size' and 'show download-write-size' commands.
3280 * New remote packets
3283 Tell a stub about GDB client features, and request remote target features.
3284 The first feature implemented is PacketSize, which allows the target to
3285 specify the size of packets it can handle - to minimize the number of
3286 packets required and improve performance when connected to a remote
3290 Fetch an OS auxilliary vector from the remote stub. This packet is a
3291 more efficient replacement for qPart:auxv:read.
3293 qXfer:memory-map:read:
3294 Fetch a memory map from the remote stub, including information about
3295 RAM, ROM, and flash memory devices.
3300 Erase and program a flash memory device.
3302 * Removed remote packets
3305 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3306 used it, and only gdbserver implemented it.
3308 *** Changes in GDB 6.5
3312 Renesas M32C/M16C m32c-elf
3314 Morpho Technologies ms1 ms1-elf
3318 init-if-undefined Initialize a convenience variable, but
3319 only if it doesn't already have a value.
3321 The following commands are presently only implemented for native GNU/Linux:
3323 checkpoint Save a snapshot of the program state.
3325 restart <n> Return the program state to a
3326 previously saved state.
3328 info checkpoints List currently saved checkpoints.
3330 delete-checkpoint <n> Delete a previously saved checkpoint.
3332 set|show detach-on-fork Tell gdb whether to detach from a newly
3333 forked process, or to keep debugging it.
3335 info forks List forks of the user program that
3336 are available to be debugged.
3338 fork <n> Switch to debugging one of several
3339 forks of the user program that are
3340 available to be debugged.
3342 delete-fork <n> Delete a fork from the list of forks
3343 that are available to be debugged (and
3344 kill the forked process).
3346 detach-fork <n> Delete a fork from the list of forks
3347 that are available to be debugged (and
3348 allow the process to continue).
3352 Morpho Technologies ms2 ms1-elf
3354 * Improved Windows host support
3356 GDB now builds as a cross debugger hosted on i686-mingw32, including
3357 native console support, and remote communications using either
3358 network sockets or serial ports.
3360 * Improved Modula-2 language support
3362 GDB can now print most types in the Modula-2 syntax. This includes:
3363 basic types, set types, record types, enumerated types, range types,
3364 pointer types and ARRAY types. Procedure var parameters are correctly
3365 printed and hexadecimal addresses and character constants are also
3366 written in the Modula-2 syntax. Best results can be obtained by using
3367 GNU Modula-2 together with the -gdwarf-2 command line option.
3371 The ARM rdi-share module.
3373 The Netware NLM debug server.
3375 *** Changes in GDB 6.4
3377 * New native configurations
3379 OpenBSD/arm arm*-*-openbsd*
3380 OpenBSD/mips64 mips64-*-openbsd*
3384 Morpho Technologies ms1 ms1-elf
3386 * New command line options
3388 --batch-silent As for --batch, but totally silent.
3389 --return-child-result The debugger will exist with the same value
3390 the child (debugged) program exited with.
3391 --eval-command COMMAND, -ex COMMAND
3392 Execute a single GDB CLI command. This may be
3393 specified multiple times and in conjunction
3394 with the --command (-x) option.
3396 * Deprecated commands removed
3398 The following commands, that were deprecated in 2000, have been
3402 set|show arm disassembly-flavor set|show arm disassembler
3403 othernames set arm disassembler
3404 set|show remotedebug set|show debug remote
3405 set|show archdebug set|show debug arch
3406 set|show eventdebug set|show debug event
3409 * New BSD user-level threads support
3411 It is now possible to debug programs using the user-level threads
3412 library on OpenBSD and FreeBSD. Currently supported (target)
3415 FreeBSD/amd64 x86_64-*-freebsd*
3416 FreeBSD/i386 i386-*-freebsd*
3417 OpenBSD/i386 i386-*-openbsd*
3419 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3420 are not yet supported.
3422 * New support for Matsushita MN10300 w/sim added
3423 (Work in progress). mn10300-elf.
3425 * REMOVED configurations and files
3427 VxWorks and the XDR protocol *-*-vxworks
3428 Motorola MCORE mcore-*-*
3429 National Semiconductor NS32000 ns32k-*-*
3431 * New "set print array-indexes" command
3433 After turning this setting "on", GDB prints the index of each element
3434 when displaying arrays. The default is "off" to preserve the previous
3437 * VAX floating point support
3439 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3441 * User-defined command support
3443 In addition to using $arg0..$arg9 for argument passing, it is now possible
3444 to use $argc to determine now many arguments have been passed. See the
3445 section on user-defined commands in the user manual for more information.
3447 *** Changes in GDB 6.3:
3449 * New command line option
3451 GDB now accepts -l followed by a number to set the timeout for remote
3454 * GDB works with GCC -feliminate-dwarf2-dups
3456 GDB now supports a more compact representation of DWARF-2 debug
3457 information using DW_FORM_ref_addr references. These are produced
3458 by GCC with the option -feliminate-dwarf2-dups and also by some
3459 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3460 to use -feliminate-dwarf2-dups.
3462 * Internationalization
3464 When supported by the host system, GDB will be built with
3465 internationalization (libintl). The task of marking up the sources is
3466 continued, we're looking forward to our first translation.
3470 Initial support for debugging programs compiled with the GNAT
3471 implementation of the Ada programming language has been integrated
3472 into GDB. In this release, support is limited to expression evaluation.
3474 * New native configurations
3476 GNU/Linux/m32r m32r-*-linux-gnu
3480 GDB's remote protocol now includes support for the 'p' packet. This
3481 packet is used to fetch individual registers from a remote inferior.
3483 * END-OF-LIFE registers[] compatibility module
3485 GDB's internal register infrastructure has been completely rewritten.
3486 The new infrastructure making possible the implementation of key new
3487 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3490 GDB 6.3 will be the last release to include the the registers[]
3491 compatibility module that allowed out-of-date configurations to
3492 continue to work. This change directly impacts the following
3502 powerpc bdm protocol
3504 Unless there is activity to revive these configurations, they will be
3505 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3507 * OBSOLETE configurations and files
3509 Configurations that have been declared obsolete in this release have
3510 been commented out. Unless there is activity to revive these
3511 configurations, the next release of GDB will have their sources
3512 permanently REMOVED.
3521 *** Changes in GDB 6.2.1:
3523 * MIPS `break main; run' gave an heuristic-fence-post warning
3525 When attempting to run even a simple program, a warning about
3526 heuristic-fence-post being hit would be reported. This problem has
3529 * MIPS IRIX 'long double' crashed GDB
3531 When examining a long double variable, GDB would get a segmentation
3532 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3533 IRIX long double values).
3537 A bug in the VAX stack code was causing problems with the "next"
3538 command. This problem has been fixed.
3540 *** Changes in GDB 6.2:
3542 * Fix for ``many threads''
3544 On GNU/Linux systems that use the NPTL threads library, a program
3545 rapidly creating and deleting threads would confuse GDB leading to the
3548 ptrace: No such process.
3549 thread_db_get_info: cannot get thread info: generic error
3551 This problem has been fixed.
3553 * "-async" and "-noasync" options removed.
3555 Support for the broken "-noasync" option has been removed (it caused
3558 * New ``start'' command.
3560 This command runs the program until the begining of the main procedure.
3562 * New BSD Kernel Data Access Library (libkvm) interface
3564 Using ``target kvm'' it is now possible to debug kernel core dumps and
3565 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3566 platforms. Currently supported (native-only) configurations are:
3568 FreeBSD/amd64 x86_64-*-freebsd*
3569 FreeBSD/i386 i?86-*-freebsd*
3570 NetBSD/i386 i?86-*-netbsd*
3571 NetBSD/m68k m68*-*-netbsd*
3572 NetBSD/sparc sparc-*-netbsd*
3573 OpenBSD/amd64 x86_64-*-openbsd*
3574 OpenBSD/i386 i?86-*-openbsd*
3575 OpenBSD/m68k m68*-openbsd*
3576 OpenBSD/sparc sparc-*-openbsd*
3578 * Signal trampoline code overhauled
3580 Many generic problems with GDB's signal handling code have been fixed.
3581 These include: backtraces through non-contiguous stacks; recognition
3582 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3583 call; backtrace through a signal trampoline; step into and out of
3584 signal handlers; and single-stepping in the signal trampoline.
3586 Please note that kernel bugs are a limiting factor here. These
3587 features have been shown to work on an s390 GNU/Linux system that
3588 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3590 * Cygwin support for DWARF 2 added.
3592 * New native configurations
3594 GNU/Linux/hppa hppa*-*-linux*
3595 OpenBSD/hppa hppa*-*-openbsd*
3596 OpenBSD/m68k m68*-*-openbsd*
3597 OpenBSD/m88k m88*-*-openbsd*
3598 OpenBSD/powerpc powerpc-*-openbsd*
3599 NetBSD/vax vax-*-netbsd*
3600 OpenBSD/vax vax-*-openbsd*
3602 * END-OF-LIFE frame compatibility module
3604 GDB's internal frame infrastructure has been completely rewritten.
3605 The new infrastructure making it possible to support key new features
3606 including DWARF 2 Call Frame Information. To aid in the task of
3607 migrating old configurations to this new infrastructure, a
3608 compatibility module, that allowed old configurations to continue to
3609 work, was also included.
3611 GDB 6.2 will be the last release to include this frame compatibility
3612 module. This change directly impacts the following configurations:
3622 Unless there is activity to revive these configurations, they will be
3623 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3625 * REMOVED configurations and files
3627 Sun 3, running SunOS 3 m68*-*-sunos3*
3628 Sun 3, running SunOS 4 m68*-*-sunos4*
3629 Sun 2, running SunOS 3 m68000-*-sunos3*
3630 Sun 2, running SunOS 4 m68000-*-sunos4*
3631 Motorola 680x0 running LynxOS m68*-*-lynxos*
3632 AT&T 3b1/Unix pc m68*-att-*
3633 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3634 decstation mips-dec-* mips-little-*
3635 riscos mips-*-riscos* mips-*-sysv*
3636 sonymips mips-sony-*
3637 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3639 *** Changes in GDB 6.1.1:
3641 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3643 The TUI (Text-mode User Interface) is now built as part of a default
3644 GDB configuration. It is enabled by either selecting the TUI with the
3645 command line option "-i=tui" or by running the separate "gdbtui"
3646 program. For more information on the TUI, see the manual "Debugging
3649 * Pending breakpoint support (also included in GDB 6.1)
3651 Support has been added to allow you to specify breakpoints in shared
3652 libraries that have not yet been loaded. If a breakpoint location
3653 cannot be found, and the "breakpoint pending" option is set to auto,
3654 GDB queries you if you wish to make the breakpoint pending on a future
3655 shared-library load. If and when GDB resolves the breakpoint symbol,
3656 the pending breakpoint is removed as one or more regular breakpoints
3659 Pending breakpoints are very useful for GCJ Java debugging.
3661 * Fixed ISO-C build problems
3663 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3664 non ISO-C code that stopped them being built using a more strict ISO-C
3665 compiler (e.g., IBM's C compiler).
3667 * Fixed build problem on IRIX 5
3669 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3670 wasn't able to compile compile on an IRIX 5 system.
3672 * Added execute permission to gdb/gdbserver/configure
3674 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3675 permission. This bug would cause configure to fail on a number of
3676 systems (Solaris, IRIX). Ref: server/519.
3678 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3680 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3681 has been updated to use constant array sizes.
3683 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3685 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3686 its generated DWARF Call Frame Info. This encoding was causing GDB to
3687 panic, that panic has been fixed. Ref: gdb/1628.
3689 * Fixed a problem when examining parameters in shared library code.
3691 When examining parameters in optimized shared library code generated
3692 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3693 not available''. GDB now correctly displays the variable's value.
3695 *** Changes in GDB 6.1:
3697 * Removed --with-mmalloc
3699 Support for the mmalloc memory manager has been removed, as it
3700 conflicted with the internal gdb byte cache.
3702 * Changes in AMD64 configurations
3704 The AMD64 target now includes the %cs and %ss registers. As a result
3705 the AMD64 remote protocol has changed; this affects the floating-point
3706 and SSE registers. If you rely on those registers for your debugging,
3707 you should upgrade gdbserver on the remote side.
3709 * Revised SPARC target
3711 The SPARC target has been completely revised, incorporating the
3712 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3713 support for LynxOS and SunOS 4 has been dropped. Calling functions
3714 from within GDB on operating systems with a non-executable stack
3715 (Solaris, OpenBSD) now works.
3719 GDB has a new C++ demangler which does a better job on the mangled
3720 names generated by current versions of g++. It also runs faster, so
3721 with this and other changes gdb should now start faster on large C++
3724 * DWARF 2 Location Expressions
3726 GDB support for location expressions has been extended to support function
3727 arguments and frame bases. Older versions of GDB could crash when they
3730 * C++ nested types and namespaces
3732 GDB's support for nested types and namespaces in C++ has been
3733 improved, especially if you use the DWARF 2 debugging format. (This
3734 is the default for recent versions of GCC on most platforms.)
3735 Specifically, if you have a class "Inner" defined within a class or
3736 namespace "Outer", then GDB realizes that the class's name is
3737 "Outer::Inner", not simply "Inner". This should greatly reduce the
3738 frequency of complaints about not finding RTTI symbols. In addition,
3739 if you are stopped at inside of a function defined within a namespace,
3740 GDB modifies its name lookup accordingly.
3742 * New native configurations
3744 NetBSD/amd64 x86_64-*-netbsd*
3745 OpenBSD/amd64 x86_64-*-openbsd*
3746 OpenBSD/alpha alpha*-*-openbsd*
3747 OpenBSD/sparc sparc-*-openbsd*
3748 OpenBSD/sparc64 sparc64-*-openbsd*
3750 * New debugging protocols
3752 M32R with SDI protocol m32r-*-elf*
3754 * "set prompt-escape-char" command deleted.
3756 The command "set prompt-escape-char" has been deleted. This command,
3757 and its very obscure effet on GDB's prompt, was never documented,
3758 tested, nor mentioned in the NEWS file.
3760 * OBSOLETE configurations and files
3762 Configurations that have been declared obsolete in this release have
3763 been commented out. Unless there is activity to revive these
3764 configurations, the next release of GDB will have their sources
3765 permanently REMOVED.
3767 Sun 3, running SunOS 3 m68*-*-sunos3*
3768 Sun 3, running SunOS 4 m68*-*-sunos4*
3769 Sun 2, running SunOS 3 m68000-*-sunos3*
3770 Sun 2, running SunOS 4 m68000-*-sunos4*
3771 Motorola 680x0 running LynxOS m68*-*-lynxos*
3772 AT&T 3b1/Unix pc m68*-att-*
3773 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3774 decstation mips-dec-* mips-little-*
3775 riscos mips-*-riscos* mips-*-sysv*
3776 sonymips mips-sony-*
3777 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3779 * REMOVED configurations and files
3781 SGI Irix-4.x mips-sgi-irix4 or iris4
3782 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3783 Z8000 simulator z8k-zilog-none or z8ksim
3784 Matsushita MN10200 w/simulator mn10200-*-*
3785 H8/500 simulator h8500-hitachi-hms or h8500hms
3786 HP/PA running BSD hppa*-*-bsd*
3787 HP/PA running OSF/1 hppa*-*-osf*
3788 HP/PA Pro target hppa*-*-pro*
3789 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3790 386BSD i[3456]86-*-bsd*
3791 Sequent family i[3456]86-sequent-sysv4*
3792 i[3456]86-sequent-sysv*
3793 i[3456]86-sequent-bsd*
3794 SPARC running LynxOS sparc-*-lynxos*
3795 SPARC running SunOS 4 sparc-*-sunos4*
3796 Tsqware Sparclet sparclet-*-*
3797 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3799 *** Changes in GDB 6.0:
3803 Support for debugging the Objective-C programming language has been
3804 integrated into GDB.
3806 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3808 DWARF 2's Call Frame Information makes available compiler generated
3809 information that more exactly describes the program's run-time stack.
3810 By using this information, GDB is able to provide more robust stack
3813 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3814 have been updated to use a new backtrace mechanism which includes
3815 DWARF 2 CFI support.
3819 GDB's remote protocol has been extended to include support for hosted
3820 file I/O (where the remote target uses GDB's file system). See GDB's
3821 remote protocol documentation for details.
3823 * All targets using the new architecture framework.
3825 All of GDB's targets have been updated to use the new internal
3826 architecture framework. The way is now open for future GDB releases
3827 to include cross-architecture native debugging support (i386 on amd64,
3830 * GNU/Linux's Thread Local Storage (TLS)
3832 GDB now includes support for for the GNU/Linux implementation of
3833 per-thread variables.
3835 * GNU/Linux's Native POSIX Thread Library (NPTL)
3837 GDB's thread code has been updated to work with either the new
3838 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3840 * Separate debug info.
3842 GDB, in conjunction with BINUTILS, now supports a mechanism for
3843 automatically loading debug information from a separate file. Instead
3844 of shipping full debug and non-debug versions of system libraries,
3845 system integrators can now instead ship just the stripped libraries
3846 and optional debug files.
3848 * DWARF 2 Location Expressions
3850 DWARF 2 Location Expressions allow the compiler to more completely
3851 describe the location of variables (even in optimized code) to the
3854 GDB now includes preliminary support for location expressions (support
3855 for DW_OP_piece is still missing).
3859 A number of long standing bugs that caused GDB to die while starting a
3860 Java application have been fixed. GDB's Java support is now
3861 considered "useable".
3863 * GNU/Linux support for fork, vfork, and exec.
3865 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3866 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3869 * GDB supports logging output to a file
3871 There are two new commands, "set logging" and "show logging", which can be
3872 used to capture GDB's output to a file.
3874 * The meaning of "detach" has changed for gdbserver
3876 The "detach" command will now resume the application, as documented. To
3877 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3880 * d10v, m68hc11 `regs' command deprecated
3882 The `info registers' command has been updated so that it displays the
3883 registers using a format identical to the old `regs' command.
3887 A new command, "maint set profile on/off", has been added. This command can
3888 be used to enable or disable profiling while running GDB, to profile a
3889 session or a set of commands. In addition there is a new configure switch,
3890 "--enable-profiling", which will cause GDB to be compiled with profiling
3891 data, for more informative profiling results.
3893 * Default MI syntax changed to "mi2".
3895 The default MI (machine interface) syntax, enabled by the command line
3896 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3897 "mi1", can be enabled by specifying the option "-i=mi1".
3899 Support for the original "mi0" syntax (included in GDB 5.0) has been
3902 Fix for gdb/192: removed extraneous space when displaying frame level.
3903 Fix for gdb/672: update changelist is now output in mi list format.
3904 Fix for gdb/702: a -var-assign that updates the value now shows up
3905 in a subsequent -var-update.
3907 * New native configurations.
3909 FreeBSD/amd64 x86_64-*-freebsd*
3911 * Multi-arched targets.
3913 HP/PA HPUX11 hppa*-*-hpux*
3914 Renesas M32R/D w/simulator m32r-*-elf*
3916 * OBSOLETE configurations and files
3918 Configurations that have been declared obsolete in this release have
3919 been commented out. Unless there is activity to revive these
3920 configurations, the next release of GDB will have their sources
3921 permanently REMOVED.
3923 Z8000 simulator z8k-zilog-none or z8ksim
3924 Matsushita MN10200 w/simulator mn10200-*-*
3925 H8/500 simulator h8500-hitachi-hms or h8500hms
3926 HP/PA running BSD hppa*-*-bsd*
3927 HP/PA running OSF/1 hppa*-*-osf*
3928 HP/PA Pro target hppa*-*-pro*
3929 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3930 Sequent family i[3456]86-sequent-sysv4*
3931 i[3456]86-sequent-sysv*
3932 i[3456]86-sequent-bsd*
3933 Tsqware Sparclet sparclet-*-*
3934 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3936 * REMOVED configurations and files
3939 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3940 IBM AIX PS/2 i[3456]86-*-aix
3941 i386 running Mach 3.0 i[3456]86-*-mach3*
3942 i386 running Mach i[3456]86-*-mach*
3943 i386 running OSF/1 i[3456]86-*osf1mk*
3944 HP/Apollo 68k Family m68*-apollo*-sysv*,
3946 m68*-hp-bsd*, m68*-hp-hpux*
3947 Argonaut Risc Chip (ARC) arc-*-*
3948 Mitsubishi D30V d30v-*-*
3949 Fujitsu FR30 fr30-*-elf*
3950 OS/9000 i[34]86-*-os9k
3951 I960 with MON960 i960-*-coff
3953 * MIPS $fp behavior changed
3955 The convenience variable $fp, for the MIPS, now consistently returns
3956 the address of the current frame's base. Previously, depending on the
3957 context, $fp could refer to either $sp or the current frame's base
3958 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3959 The GNU Source-Level Debugger''.
3961 *** Changes in GDB 5.3:
3963 * GNU/Linux shared library multi-threaded performance improved.
3965 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3966 `/proc', in preference to `ptrace' for memory reads. This may result
3967 in an improvement in the start-up time of multi-threaded, shared
3968 library applications when run under GDB. One GDB user writes: ``loads
3969 shared libs like mad''.
3971 * ``gdbserver'' now supports multi-threaded applications on some targets
3973 Support for debugging multi-threaded applications which use
3974 the GNU/Linux LinuxThreads package has been added for
3975 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3976 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3978 * GDB now supports C/C++ preprocessor macros.
3980 GDB now expands preprocessor macro invocations in C/C++ expressions,
3981 and provides various commands for showing macro definitions and how
3984 The new command `macro expand EXPRESSION' expands any macro
3985 invocations in expression, and shows the result.
3987 The new command `show macro MACRO-NAME' shows the definition of the
3988 macro named MACRO-NAME, and where it was defined.
3990 Most compilers don't include information about macros in the debugging
3991 information by default. In GCC 3.1, for example, you need to compile
3992 your program with the options `-gdwarf-2 -g3'. If the macro
3993 information is present in the executable, GDB will read it.
3995 * Multi-arched targets.
3997 DEC Alpha (partial) alpha*-*-*
3998 DEC VAX (partial) vax-*-*
4000 National Semiconductor NS32000 (partial) ns32k-*-*
4001 Motorola 68000 (partial) m68k-*-*
4002 Motorola MCORE mcore-*-*
4006 Fujitsu FRV architecture added by Red Hat frv*-*-*
4009 * New native configurations
4011 Alpha NetBSD alpha*-*-netbsd*
4012 SH NetBSD sh*-*-netbsdelf*
4013 MIPS NetBSD mips*-*-netbsd*
4014 UltraSPARC NetBSD sparc64-*-netbsd*
4016 * OBSOLETE configurations and files
4018 Configurations that have been declared obsolete in this release have
4019 been commented out. Unless there is activity to revive these
4020 configurations, the next release of GDB will have their sources
4021 permanently REMOVED.
4023 Mitsubishi D30V d30v-*-*
4024 OS/9000 i[34]86-*-os9k
4025 IBM AIX PS/2 i[3456]86-*-aix
4026 Fujitsu FR30 fr30-*-elf*
4027 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4028 Argonaut Risc Chip (ARC) arc-*-*
4029 i386 running Mach 3.0 i[3456]86-*-mach3*
4030 i386 running Mach i[3456]86-*-mach*
4031 i386 running OSF/1 i[3456]86-*osf1mk*
4032 HP/Apollo 68k Family m68*-apollo*-sysv*,
4034 m68*-hp-bsd*, m68*-hp-hpux*
4035 I960 with MON960 i960-*-coff
4037 * OBSOLETE languages
4039 CHILL, a Pascal like language used by telecommunications companies.
4041 * REMOVED configurations and files
4043 AMD 29k family via UDI a29k-amd-udi, udi29k
4044 A29K VxWorks a29k-*-vxworks
4045 AMD 29000 embedded, using EBMON a29k-none-none
4046 AMD 29000 embedded with COFF a29k-none-coff
4047 AMD 29000 embedded with a.out a29k-none-aout
4049 testsuite/gdb.hp/gdb.threads-hp/ directory
4051 * New command "set max-user-call-depth <nnn>"
4053 This command allows the user to limit the call depth of user-defined
4054 commands. The default is 1024.
4056 * Changes in FreeBSD/i386 native debugging.
4058 Support for the "generate-core-file" has been added.
4060 * New commands "dump", "append", and "restore".
4062 These commands allow data to be copied from target memory
4063 to a bfd-format or binary file (dump and append), and back
4064 from a file into memory (restore).
4066 * Improved "next/step" support on multi-processor Alpha Tru64.
4068 The previous single-step mechanism could cause unpredictable problems,
4069 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4070 of a software single-step mechanism prevents this.
4072 *** Changes in GDB 5.2.1:
4080 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4081 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4082 Fix, by Joel Brobecker imported from mainline.
4084 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4085 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4086 Fix, by Fred Fish, imported from mainline.
4088 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4089 Surprisingly enough, it works now.
4090 By Michal Ludvig, imported from mainline.
4092 i386 hardware watchpoint support:
4093 avoid misses on second run for some targets.
4094 By Pierre Muller, imported from mainline.
4096 *** Changes in GDB 5.2:
4098 * New command "set trust-readonly-sections on[off]".
4100 This command is a hint that tells gdb that read-only sections
4101 really are read-only (ie. that their contents will not change).
4102 In this mode, gdb will go to the object file rather than the
4103 target to read memory from read-only sections (such as ".text").
4104 This can be a significant performance improvement on some
4105 (notably embedded) targets.
4107 * New command "generate-core-file" (or "gcore").
4109 This new gdb command allows the user to drop a core file of the child
4110 process state at any time. So far it's been implemented only for
4111 GNU/Linux and Solaris, but should be relatively easily ported to other
4112 hosts. Argument is core file name (defaults to core.<pid>).
4114 * New command line option
4116 GDB now accepts --pid or -p followed by a process id.
4118 * Change in command line behavior -- corefiles vs. process ids.
4120 There is a subtle behavior in the way in which GDB handles
4121 command line arguments. The first non-flag argument is always
4122 a program to debug, but the second non-flag argument may either
4123 be a corefile or a process id. Previously, GDB would attempt to
4124 open the second argument as a corefile, and if that failed, would
4125 issue a superfluous error message and then attempt to attach it as
4126 a process. Now, if the second argument begins with a non-digit,
4127 it will be treated as a corefile. If it begins with a digit,
4128 GDB will attempt to attach it as a process, and if no such process
4129 is found, will then attempt to open it as a corefile.
4131 * Changes in ARM configurations.
4133 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4134 configuration is fully multi-arch.
4136 * New native configurations
4138 ARM NetBSD arm*-*-netbsd*
4139 x86 OpenBSD i[3456]86-*-openbsd*
4140 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4141 Sparc64 running FreeBSD sparc64-*-freebsd*
4145 Sanyo XStormy16 xstormy16-elf
4147 * OBSOLETE configurations and files
4149 Configurations that have been declared obsolete in this release have
4150 been commented out. Unless there is activity to revive these
4151 configurations, the next release of GDB will have their sources
4152 permanently REMOVED.
4154 AMD 29k family via UDI a29k-amd-udi, udi29k
4155 A29K VxWorks a29k-*-vxworks
4156 AMD 29000 embedded, using EBMON a29k-none-none
4157 AMD 29000 embedded with COFF a29k-none-coff
4158 AMD 29000 embedded with a.out a29k-none-aout
4160 testsuite/gdb.hp/gdb.threads-hp/ directory
4162 * REMOVED configurations and files
4164 TI TMS320C80 tic80-*-*
4166 PowerPC Solaris powerpcle-*-solaris*
4167 PowerPC Windows NT powerpcle-*-cygwin32
4168 PowerPC Netware powerpc-*-netware*
4169 Harris/CXUX m88k m88*-harris-cxux*
4170 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4171 ns32k-utek-sysv* ns32k-utek-*
4172 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4173 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4174 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4175 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4176 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4178 * Changes to command line processing
4180 The new `--args' feature can be used to specify command-line arguments
4181 for the inferior from gdb's command line.
4183 * Changes to key bindings
4185 There is a new `operate-and-get-next' function bound to `C-o'.
4187 *** Changes in GDB 5.1.1
4189 Fix compile problem on DJGPP.
4191 Fix a problem with floating-point registers on the i386 being
4194 Fix to stop GDB crashing on .debug_str debug info.
4196 Numerous documentation fixes.
4198 Numerous testsuite fixes.
4200 *** Changes in GDB 5.1:
4202 * New native configurations
4204 Alpha FreeBSD alpha*-*-freebsd*
4205 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4206 MIPS GNU/Linux mips*-*-linux*
4207 MIPS SGI Irix 6.x mips*-sgi-irix6*
4208 ia64 AIX ia64-*-aix*
4209 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4213 Motorola 68HC11 and 68HC12 m68hc11-elf
4215 UltraSparc running GNU/Linux sparc64-*-linux*
4217 * OBSOLETE configurations and files
4219 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4220 Harris/CXUX m88k m88*-harris-cxux*
4221 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4222 ns32k-utek-sysv* ns32k-utek-*
4223 TI TMS320C80 tic80-*-*
4225 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4226 PowerPC Solaris powerpcle-*-solaris*
4227 PowerPC Windows NT powerpcle-*-cygwin32
4228 PowerPC Netware powerpc-*-netware*
4229 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4230 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4231 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4232 Apple Macintosh (MPW) host N/A
4234 stuff.c (Program to stuff files into a specially prepared space in kdb)
4235 kdb-start.c (Main loop for the standalone kernel debugger)
4237 Configurations that have been declared obsolete in this release have
4238 been commented out. Unless there is activity to revive these
4239 configurations, the next release of GDB will have their sources
4240 permanently REMOVED.
4242 * REMOVED configurations and files
4244 Altos 3068 m68*-altos-*
4245 Convex c1-*-*, c2-*-*
4247 ARM RISCix arm-*-* (as host)
4251 * GDB has been converted to ISO C.
4253 GDB's source code has been converted to ISO C. In particular, the
4254 sources are fully protoized, and rely on standard headers being
4259 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4261 * The MI enabled by default.
4263 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4264 revised and enabled by default. Packages which use GDB as a debugging
4265 engine behind a UI or another front end are encouraged to switch to
4266 using the GDB/MI interface, instead of the old annotations interface
4267 which is now deprecated.
4269 * Support for debugging Pascal programs.
4271 GDB now includes support for debugging Pascal programs. The following
4272 main features are supported:
4274 - Pascal-specific data types such as sets;
4276 - automatic recognition of Pascal sources based on file-name
4279 - Pascal-style display of data types, variables, and functions;
4281 - a Pascal expression parser.
4283 However, some important features are not yet supported.
4285 - Pascal string operations are not supported at all;
4287 - there are some problems with boolean types;
4289 - Pascal type hexadecimal constants are not supported
4290 because they conflict with the internal variables format;
4292 - support for Pascal objects and classes is not full yet;
4294 - unlike Pascal, GDB is case-sensitive for symbol names.
4296 * Changes in completion.
4298 Commands such as `shell', `run' and `set args', which pass arguments
4299 to inferior programs, now complete on file names, similar to what
4300 users expect at the shell prompt.
4302 Commands which accept locations, such as `disassemble', `print',
4303 `breakpoint', `until', etc. now complete on filenames as well as
4304 program symbols. Thus, if you type "break foob TAB", and the source
4305 files linked into the programs include `foobar.c', that file name will
4306 be one of the candidates for completion. However, file names are not
4307 considered for completion after you typed a colon that delimits a file
4308 name from a name of a function in that file, as in "break foo.c:bar".
4310 `set demangle-style' completes on available demangling styles.
4312 * New platform-independent commands:
4314 It is now possible to define a post-hook for a command as well as a
4315 hook that runs before the command. For more details, see the
4316 documentation of `hookpost' in the GDB manual.
4318 * Changes in GNU/Linux native debugging.
4320 Support for debugging multi-threaded programs has been completely
4321 revised for all platforms except m68k and sparc. You can now debug as
4322 many threads as your system allows you to have.
4324 Attach/detach is supported for multi-threaded programs.
4326 Support for SSE registers was added for x86. This doesn't work for
4327 multi-threaded programs though.
4329 * Changes in MIPS configurations.
4331 Multi-arch support is enabled for all MIPS configurations.
4333 GDB can now be built as native debugger on SGI Irix 6.x systems for
4334 debugging n32 executables. (Debugging 64-bit executables is not yet
4337 * Unified support for hardware watchpoints in all x86 configurations.
4339 Most (if not all) native x86 configurations support hardware-assisted
4340 breakpoints and watchpoints in a unified manner. This support
4341 implements debug register sharing between watchpoints, which allows to
4342 put a virtually infinite number of watchpoints on the same address,
4343 and also supports watching regions up to 16 bytes with several debug
4346 The new maintenance command `maintenance show-debug-regs' toggles
4347 debugging print-outs in functions that insert, remove, and test
4348 watchpoints and hardware breakpoints.
4350 * Changes in the DJGPP native configuration.
4352 New command ``info dos sysinfo'' displays assorted information about
4353 the CPU, OS, memory, and DPMI server.
4355 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4356 display information about segment descriptors stored in GDT, LDT, and
4359 New commands ``info dos pde'' and ``info dos pte'' display entries
4360 from Page Directory and Page Tables (for now works with CWSDPMI only).
4361 New command ``info dos address-pte'' displays the Page Table entry for
4362 a given linear address.
4364 GDB can now pass command lines longer than 126 characters to the
4365 program being debugged (requires an update to the libdbg.a library
4366 which is part of the DJGPP development kit).
4368 DWARF2 debug info is now supported.
4370 It is now possible to `step' and `next' through calls to `longjmp'.
4372 * Changes in documentation.
4374 All GDB documentation was converted to GFDL, the GNU Free
4375 Documentation License.
4377 Tracepoints-related commands are now fully documented in the GDB
4380 TUI, the Text-mode User Interface, is now documented in the manual.
4382 Tracepoints-related commands are now fully documented in the GDB
4385 The "GDB Internals" manual now has an index. It also includes
4386 documentation of `ui_out' functions, GDB coding standards, x86
4387 hardware watchpoints, and memory region attributes.
4389 * GDB's version number moved to ``version.in''
4391 The Makefile variable VERSION has been replaced by the file
4392 ``version.in''. People creating GDB distributions should update the
4393 contents of this file.
4397 GUD support is now a standard part of the EMACS distribution.
4399 *** Changes in GDB 5.0:
4401 * Improved support for debugging FP programs on x86 targets
4403 Unified and much-improved support for debugging floating-point
4404 programs on all x86 targets. In particular, ``info float'' now
4405 displays the FP registers in the same format on all x86 targets, with
4406 greater level of detail.
4408 * Improvements and bugfixes in hardware-assisted watchpoints
4410 It is now possible to watch array elements, struct members, and
4411 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4412 on x86 targets no longer erroneously trigger when the address is
4415 * Improvements in the native DJGPP version of GDB
4417 The distribution now includes all the scripts and auxiliary files
4418 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4419 machines ``out of the box''.
4421 The DJGPP version can now debug programs that use signals. It is
4422 possible to catch signals that happened in the debuggee, deliver
4423 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4424 would kill the program being debugged.) Programs that hook hardware
4425 interrupts (keyboard, timer, etc.) can also be debugged.
4427 It is now possible to debug DJGPP programs that redirect their
4428 standard handles or switch them to raw (as opposed to cooked) mode, or
4429 even close them. The command ``run < foo > bar'' works as expected,
4430 and ``info terminal'' reports useful information about the debuggee's
4431 terminal, including raw/cooked mode, redirection, etc.
4433 The DJGPP version now uses termios functions for console I/O, which
4434 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4437 DOS-style file names with drive letters are now fully supported by
4440 It is now possible to debug DJGPP programs that switch their working
4441 directory. It is also possible to rerun the debuggee any number of
4442 times without restarting GDB; thus, you can use the same setup,
4443 breakpoints, etc. for many debugging sessions.
4445 * New native configurations
4447 ARM GNU/Linux arm*-*-linux*
4448 PowerPC GNU/Linux powerpc-*-linux*
4452 Motorola MCore mcore-*-*
4453 x86 VxWorks i[3456]86-*-vxworks*
4454 PowerPC VxWorks powerpc-*-vxworks*
4455 TI TMS320C80 tic80-*-*
4457 * OBSOLETE configurations
4459 Altos 3068 m68*-altos-*
4460 Convex c1-*-*, c2-*-*
4462 ARM RISCix arm-*-* (as host)
4465 Configurations that have been declared obsolete will be commented out,
4466 but the code will be left in place. If there is no activity to revive
4467 these configurations before the next release of GDB, the sources will
4468 be permanently REMOVED.
4470 * Gould support removed
4472 Support for the Gould PowerNode and NP1 has been removed.
4474 * New features for SVR4
4476 On SVR4 native platforms (such as Solaris), if you attach to a process
4477 without first loading a symbol file, GDB will now attempt to locate and
4478 load symbols from the running process's executable file.
4480 * Many C++ enhancements
4482 C++ support has been greatly improved. Overload resolution now works properly
4483 in almost all cases. RTTI support is on the way.
4485 * Remote targets can connect to a sub-program
4487 A popen(3) style serial-device has been added. This device starts a
4488 sub-process (such as a stand-alone simulator) and then communicates
4489 with that. The sub-program to run is specified using the syntax
4490 ``|<program> <args>'' vis:
4492 (gdb) set remotedebug 1
4493 (gdb) target extended-remote |mn10300-elf-sim program-args
4495 * MIPS 64 remote protocol
4497 A long standing bug in the mips64 remote protocol where by GDB
4498 expected certain 32 bit registers (ex SR) to be transfered as 32
4499 instead of 64 bits has been fixed.
4501 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4502 added to provide backward compatibility with older versions of GDB.
4504 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4506 The command ``set remotebinarydownload'' command has been replaced by
4507 ``set remote X-packet''. Other commands in ``set remote'' family
4508 include ``set remote P-packet''.
4510 * Breakpoint commands accept ranges.
4512 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4513 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4514 ``tracepoint passcount'' also accepts a range of tracepoints.
4516 * ``apropos'' command added.
4518 The ``apropos'' command searches through command names and
4519 documentation strings, printing out matches, making it much easier to
4520 try to find a command that does what you are looking for.
4524 A new machine oriented interface (MI) has been added to GDB. This
4525 interface is designed for debug environments running GDB as a separate
4526 process. This is part of the long term libGDB project. See the
4527 "GDB/MI" chapter of the GDB manual for further information. It can be
4528 enabled by configuring with:
4530 .../configure --enable-gdbmi
4532 *** Changes in GDB-4.18:
4534 * New native configurations
4536 HP-UX 10.20 hppa*-*-hpux10.20
4537 HP-UX 11.x hppa*-*-hpux11.0*
4538 M68K GNU/Linux m68*-*-linux*
4542 Fujitsu FR30 fr30-*-elf*
4543 Intel StrongARM strongarm-*-*
4544 Mitsubishi D30V d30v-*-*
4546 * OBSOLETE configurations
4548 Gould PowerNode, NP1 np1-*-*, pn-*-*
4550 Configurations that have been declared obsolete will be commented out,
4551 but the code will be left in place. If there is no activity to revive
4552 these configurations before the next release of GDB, the sources will
4553 be permanently REMOVED.
4557 As a compatibility experiment, GDB's source files buildsym.h and
4558 buildsym.c have been converted to pure standard C, no longer
4559 containing any K&R compatibility code. We believe that all systems in
4560 use today either come with a standard C compiler, or have a GCC port
4561 available. If this is not true, please report the affected
4562 configuration to bug-gdb@gnu.org immediately. See the README file for
4563 information about getting a standard C compiler if you don't have one
4568 GDB now uses readline 2.2.
4570 * set extension-language
4572 You can now control the mapping between filename extensions and source
4573 languages by using the `set extension-language' command. For instance,
4574 you can ask GDB to treat .c files as C++ by saying
4575 set extension-language .c c++
4576 The command `info extensions' lists all of the recognized extensions
4577 and their associated languages.
4579 * Setting processor type for PowerPC and RS/6000
4581 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4582 you can use the `set processor' command to specify what variant of the
4583 PowerPC family you are debugging. The command
4587 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4588 following PowerPC and RS6000 variants:
4590 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4591 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4593 403GC IBM PowerPC 403GC
4594 505 Motorola PowerPC 505
4595 860 Motorola PowerPC 860 or 850
4596 601 Motorola PowerPC 601
4597 602 Motorola PowerPC 602
4598 603 Motorola/IBM PowerPC 603 or 603e
4599 604 Motorola PowerPC 604 or 604e
4600 750 Motorola/IBM PowerPC 750 or 750
4602 At the moment, this command just tells GDB what to name the
4603 special-purpose processor registers. Since almost all the affected
4604 registers are inaccessible to user-level programs, this command is
4605 only useful for remote debugging in its present form.
4609 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4610 more extensive support for HP-UX. Added features include shared
4611 library support, kernel threads and hardware watchpoints for 11.00,
4612 support for HP's ANSI C and C++ compilers, and a compatibility mode
4613 for xdb and dbx commands.
4617 HP's donation includes the new concept of catchpoints, which is a
4618 generalization of the old catch command. On HP-UX, it is now possible
4619 to catch exec, fork, and vfork, as well as library loading.
4621 This means that the existing catch command has changed; its first
4622 argument now specifies the type of catch to be set up. See the
4623 output of "help catch" for a list of catchpoint types.
4625 * Debugging across forks
4627 On HP-UX, you can choose which process to debug when a fork() happens
4632 HP has donated a curses-based terminal user interface (TUI). To get
4633 it, build with --enable-tui. Although this can be enabled for any
4634 configuration, at present it only works for native HP debugging.
4636 * GDB remote protocol additions
4638 A new protocol packet 'X' that writes binary data is now available.
4639 Default behavior is to try 'X', then drop back to 'M' if the stub
4640 fails to respond. The settable variable `remotebinarydownload'
4641 allows explicit control over the use of 'X'.
4643 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4644 full 64-bit address. The command
4646 set remoteaddresssize 32
4648 can be used to revert to the old behaviour. For existing remote stubs
4649 the change should not be noticed, as the additional address information
4652 In order to assist in debugging stubs, you may use the maintenance
4653 command `packet' to send any text string to the stub. For instance,
4655 maint packet heythere
4657 sends the packet "$heythere#<checksum>". Note that it is very easy to
4658 disrupt a debugging session by sending the wrong packet at the wrong
4661 The compare-sections command allows you to compare section data on the
4662 target to what is in the executable file without uploading or
4663 downloading, by comparing CRC checksums.
4665 * Tracing can collect general expressions
4667 You may now collect general expressions at tracepoints. This requires
4668 further additions to the target-side stub; see tracepoint.c and
4669 doc/agentexpr.texi for further details.
4671 * mask-address variable for Mips
4673 For Mips targets, you may control the zeroing of the upper 32 bits of
4674 a 64-bit address by entering `set mask-address on'. This is mainly
4675 of interest to users of embedded R4xxx and R5xxx processors.
4677 * Higher serial baud rates
4679 GDB's serial code now allows you to specify baud rates 57600, 115200,
4680 230400, and 460800 baud. (Note that your host system may not be able
4681 to achieve all of these rates.)
4685 The i960 configuration now includes an initial implementation of a
4686 builtin simulator, contributed by Jim Wilson.
4689 *** Changes in GDB-4.17:
4691 * New native configurations
4693 Alpha GNU/Linux alpha*-*-linux*
4694 Unixware 2.x i[3456]86-unixware2*
4695 Irix 6.x mips*-sgi-irix6*
4696 PowerPC GNU/Linux powerpc-*-linux*
4697 PowerPC Solaris powerpcle-*-solaris*
4698 Sparc GNU/Linux sparc-*-linux*
4699 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4703 Argonaut Risc Chip (ARC) arc-*-*
4704 Hitachi H8/300S h8300*-*-*
4705 Matsushita MN10200 w/simulator mn10200-*-*
4706 Matsushita MN10300 w/simulator mn10300-*-*
4707 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4708 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4709 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4710 Mitsubishi D10V w/simulator d10v-*-*
4711 Mitsubishi M32R/D w/simulator m32r-*-elf*
4712 Tsqware Sparclet sparclet-*-*
4713 NEC V850 w/simulator v850-*-*
4715 * New debugging protocols
4717 ARM with RDI protocol arm*-*-*
4718 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4719 DDB and LSI variants of PMON protocol mips*-*-*
4720 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4721 PowerPC with SDS protocol powerpc{,le}-*-eabi
4722 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4726 All configurations can now understand and use the DWARF 2 debugging
4727 format. The choice is automatic, if the symbol file contains DWARF 2
4732 GDB now includes basic Java language support. This support is
4733 only useful with Java compilers that produce native machine code.
4735 * solib-absolute-prefix and solib-search-path
4737 For SunOS and SVR4 shared libraries, you may now set the prefix for
4738 loading absolute shared library symbol files, and the search path for
4739 locating non-absolute shared library symbol files.
4741 * Live range splitting
4743 GDB can now effectively debug code for which GCC has performed live
4744 range splitting as part of its optimization. See gdb/doc/LRS for
4745 more details on the expected format of the stabs information.
4749 GDB's support for the GNU Hurd, including thread debugging, has been
4750 updated to work with current versions of the Hurd.
4754 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4755 instruction set. ARM GDB automatically detects when Thumb
4756 instructions are in use, and adjusts disassembly and backtracing
4761 GDB's MIPS target configurations now handle the MIP16 16-bit
4766 GDB now includes support for overlays; if an executable has been
4767 linked such that multiple sections are based at the same address, GDB
4768 will decide which section to use for symbolic info. You can choose to
4769 control the decision manually, using overlay commands, or implement
4770 additional target-side support and use "overlay load-target" to bring
4771 in the overlay mapping. Do "help overlay" for more detail.
4775 The command "info symbol <address>" displays information about
4776 the symbol at the specified address.
4780 The standard remote protocol now includes an extension that allows
4781 asynchronous collection and display of trace data. This requires
4782 extensive support in the target-side debugging stub. Tracing mode
4783 includes a new interaction mode in GDB and new commands: see the
4784 file tracepoint.c for more details.
4788 Configurations for embedded MIPS now include a simulator contributed
4789 by Cygnus Solutions. The simulator supports the instruction sets
4790 of most MIPS variants.
4794 Sparc configurations may now include the ERC32 simulator contributed
4795 by the European Space Agency. The simulator is not built into
4796 Sparc targets by default; configure with --enable-sim to include it.
4800 For target configurations that may include multiple variants of a
4801 basic architecture (such as MIPS and SH), you may now set the
4802 architecture explicitly. "set arch" sets, "info arch" lists
4803 the possible architectures.
4805 *** Changes in GDB-4.16:
4807 * New native configurations
4809 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4810 M68K NetBSD m68k-*-netbsd*
4811 PowerPC AIX 4.x powerpc-*-aix*
4812 PowerPC MacOS powerpc-*-macos*
4813 PowerPC Windows NT powerpcle-*-cygwin32
4814 RS/6000 AIX 4.x rs6000-*-aix4*
4818 ARM with RDP protocol arm-*-*
4819 I960 with MON960 i960-*-coff
4820 MIPS VxWorks mips*-*-vxworks*
4821 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4822 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4824 Matra Sparclet sparclet-*-*
4828 The powerpc-eabi configuration now includes the PSIM simulator,
4829 contributed by Andrew Cagney, with assistance from Mike Meissner.
4830 PSIM is a very elaborate model of the PowerPC, including not only
4831 basic instruction set execution, but also details of execution unit
4832 performance and I/O hardware. See sim/ppc/README for more details.
4836 GDB now works with Solaris 2.5.
4838 * Windows 95/NT native
4840 GDB will now work as a native debugger on Windows 95 and Windows NT.
4841 To build it from source, you must use the "gnu-win32" environment,
4842 which uses a DLL to emulate enough of Unix to run the GNU tools.
4843 Further information, binaries, and sources are available at
4844 ftp.cygnus.com, under pub/gnu-win32.
4846 * dont-repeat command
4848 If a user-defined command includes the command `dont-repeat', then the
4849 command will not be repeated if the user just types return. This is
4850 useful if the command is time-consuming to run, so that accidental
4851 extra keystrokes don't run the same command many times.
4853 * Send break instead of ^C
4855 The standard remote protocol now includes an option to send a break
4856 rather than a ^C to the target in order to interrupt it. By default,
4857 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4859 * Remote protocol timeout
4861 The standard remote protocol includes a new variable `remotetimeout'
4862 that allows you to set the number of seconds before GDB gives up trying
4863 to read from the target. The default value is 2.
4865 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4867 By default GDB will automatically keep track of objects as they are
4868 loaded and unloaded by the dynamic linker. By using the command `set
4869 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4870 when shared library events occur, thus allowing you to set breakpoints
4871 in shared libraries which are explicitly loaded by the inferior.
4873 Note this feature does not work on hpux8. On hpux9 you must link
4874 /usr/lib/end.o into your program. This feature should work
4875 automatically on hpux10.
4877 * Irix 5.x hardware watchpoint support
4879 Irix 5 configurations now support the use of hardware watchpoints.
4881 * Mips protocol "SYN garbage limit"
4883 When debugging a Mips target using the `target mips' protocol, you
4884 may set the number of characters that GDB will ignore by setting
4885 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4886 every character. The default value is 1050.
4888 * Recording and replaying remote debug sessions
4890 If you set `remotelogfile' to the name of a file, gdb will write to it
4891 a recording of a remote debug session. This recording may then be
4892 replayed back to gdb using "gdbreplay". See gdbserver/README for
4893 details. This is useful when you have a problem with GDB while doing
4894 remote debugging; you can make a recording of the session and send it
4895 to someone else, who can then recreate the problem.
4897 * Speedups for remote debugging
4899 GDB includes speedups for downloading and stepping MIPS systems using
4900 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4901 and more efficient S-record downloading.
4903 * Memory use reductions and statistics collection
4905 GDB now uses less memory and reports statistics about memory usage.
4906 Try the `maint print statistics' command, for example.
4908 *** Changes in GDB-4.15:
4910 * Psymtabs for XCOFF
4912 The symbol reader for AIX GDB now uses partial symbol tables. This
4913 can greatly improve startup time, especially for large executables.
4915 * Remote targets use caching
4917 Remote targets now use a data cache to speed up communication with the
4918 remote side. The data cache could lead to incorrect results because
4919 it doesn't know about volatile variables, thus making it impossible to
4920 debug targets which use memory mapped I/O devices. `set remotecache
4921 off' turns the the data cache off.
4923 * Remote targets may have threads
4925 The standard remote protocol now includes support for multiple threads
4926 in the target system, using new protocol commands 'H' and 'T'. See
4927 gdb/remote.c for details.
4931 If GDB is configured with `--enable-netrom', then it will include
4932 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4933 acts as though it is a bank of ROM on the target board, but you can
4934 write into it over the network. GDB's support consists only of
4935 support for fast loading into the emulated ROM; to debug, you must use
4936 another protocol, such as standard remote protocol. The usual
4937 sequence is something like
4939 target nrom <netrom-hostname>
4941 target remote <netrom-hostname>:1235
4945 GDB now includes support for the Apple Macintosh, as a host only. It
4946 may be run as either an MPW tool or as a standalone application, and
4947 it can debug through the serial port. All the usual GDB commands are
4948 available, but to the target command, you must supply "serial" as the
4949 device type instead of "/dev/ttyXX". See mpw-README in the main
4950 directory for more information on how to build. The MPW configuration
4951 scripts */mpw-config.in support only a few targets, and only the
4952 mips-idt-ecoff target has been tested.
4956 GDB configuration now uses autoconf. This is not user-visible,
4957 but does simplify configuration and building.
4961 GDB now supports hpux10.
4963 *** Changes in GDB-4.14:
4965 * New native configurations
4967 x86 FreeBSD i[345]86-*-freebsd
4968 x86 NetBSD i[345]86-*-netbsd
4969 NS32k NetBSD ns32k-*-netbsd
4970 Sparc NetBSD sparc-*-netbsd
4974 A29K VxWorks a29k-*-vxworks
4975 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4976 CPU32 EST-300 emulator m68*-*-est*
4977 PowerPC ELF powerpc-*-elf
4980 * Alpha OSF/1 support for procfs
4982 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4983 possible to attach to running processes. As the mounting of the /proc
4984 filesystem is optional on the Alpha, GDB automatically determines
4985 the availability of /proc during startup. This can lead to problems
4986 if /proc is unmounted after GDB has been started.
4988 * Arguments to user-defined commands
4990 User commands may accept up to 10 arguments separated by whitespace.
4991 Arguments are accessed within the user command via $arg0..$arg9. A
4994 print $arg0 + $arg1 + $arg2
4996 To execute the command use:
4999 Defines the command "adder" which prints the sum of its three arguments.
5000 Note the arguments are text substitutions, so they may reference variables,
5001 use complex expressions, or even perform inferior function calls.
5003 * New `if' and `while' commands
5005 This makes it possible to write more sophisticated user-defined
5006 commands. Both commands take a single argument, which is the
5007 expression to evaluate, and must be followed by the commands to
5008 execute, one per line, if the expression is nonzero, the list being
5009 terminated by the word `end'. The `if' command list may include an
5010 `else' word, which causes the following commands to be executed only
5011 if the expression is zero.
5013 * Fortran source language mode
5015 GDB now includes partial support for Fortran 77. It will recognize
5016 Fortran programs and can evaluate a subset of Fortran expressions, but
5017 variables and functions may not be handled correctly. GDB will work
5018 with G77, but does not yet know much about symbols emitted by other
5021 * Better HPUX support
5023 Most debugging facilities now work on dynamic executables for HPPAs
5024 running hpux9 or later. You can attach to running dynamically linked
5025 processes, but by default the dynamic libraries will be read-only, so
5026 for instance you won't be able to put breakpoints in them. To change
5027 that behavior do the following before running the program:
5033 This will cause the libraries to be mapped private and read-write.
5034 To revert to the normal behavior, do this:
5040 You cannot set breakpoints or examine data in the library until after
5041 the library is loaded if the function/data symbols do not have
5044 GDB can now also read debug symbols produced by the HP C compiler on
5045 HPPAs (sorry, no C++, Fortran or 68k support).
5047 * Target byte order now dynamically selectable
5049 You can choose which byte order to use with a target system, via the
5050 commands "set endian big" and "set endian little", and you can see the
5051 current setting by using "show endian". You can also give the command
5052 "set endian auto", in which case GDB will use the byte order
5053 associated with the executable. Currently, only embedded MIPS
5054 configurations support dynamic selection of target byte order.
5056 * New DOS host serial code
5058 This version uses DPMI interrupts to handle buffered I/O, so you
5059 no longer need to run asynctsr when debugging boards connected to
5062 *** Changes in GDB-4.13:
5064 * New "complete" command
5066 This lists all the possible completions for the rest of the line, if it
5067 were to be given as a command itself. This is intended for use by emacs.
5069 * Trailing space optional in prompt
5071 "set prompt" no longer adds a space for you after the prompt you set. This
5072 allows you to set a prompt which ends in a space or one that does not.
5074 * Breakpoint hit counts
5076 "info break" now displays a count of the number of times the breakpoint
5077 has been hit. This is especially useful in conjunction with "ignore"; you
5078 can ignore a large number of breakpoint hits, look at the breakpoint info
5079 to see how many times the breakpoint was hit, then run again, ignoring one
5080 less than that number, and this will get you quickly to the last hit of
5083 * Ability to stop printing at NULL character
5085 "set print null-stop" will cause GDB to stop printing the characters of
5086 an array when the first NULL is encountered. This is useful when large
5087 arrays actually contain only short strings.
5089 * Shared library breakpoints
5091 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5092 breakpoints in shared libraries before the executable is run.
5094 * Hardware watchpoints
5096 There is a new hardware breakpoint for the watch command for sparclite
5097 targets. See gdb/sparclite/hw_breakpoint.note.
5099 Hardware watchpoints are also now supported under GNU/Linux.
5103 Annotations have been added. These are for use with graphical interfaces,
5104 and are still experimental. Currently only gdba.el uses these.
5106 * Improved Irix 5 support
5108 GDB now works properly with Irix 5.2.
5110 * Improved HPPA support
5112 GDB now works properly with the latest GCC and GAS.
5114 * New native configurations
5116 Sequent PTX4 i[34]86-sequent-ptx4
5117 HPPA running OSF/1 hppa*-*-osf*
5118 Atari TT running SVR4 m68*-*-sysv4*
5119 RS/6000 LynxOS rs6000-*-lynxos*
5123 OS/9000 i[34]86-*-os9k
5124 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5127 * Hitachi SH7000 and E7000-PC ICE support
5129 There is now support for communicating with the Hitachi E7000-PC ICE.
5130 This is available automatically when GDB is configured for the SH.
5134 As usual, a variety of small fixes and improvements, both generic
5135 and configuration-specific. See the ChangeLog for more detail.
5137 *** Changes in GDB-4.12:
5139 * Irix 5 is now supported
5143 GDB-4.12 on the HPPA has a number of changes which make it unable
5144 to debug the output from the currently released versions of GCC and
5145 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5146 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5147 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5150 *** Changes in GDB-4.11:
5152 * User visible changes:
5156 The "set remotedebug" option is now consistent between the mips remote
5157 target, remote targets using the gdb-specific protocol, UDI (AMD's
5158 debug protocol for the 29k) and the 88k bug monitor. It is now an
5159 integer specifying a debug level (normally 0 or 1, but 2 means more
5160 debugging info for the mips target).
5162 * DEC Alpha native support
5164 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5165 debug info, but GDB works fairly well with the DEC compiler and should
5166 work with a future GCC release. See the README file for a few
5167 Alpha-specific notes.
5169 * Preliminary thread implementation
5171 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5173 * LynxOS native and target support for 386
5175 This release has been hosted on LynxOS 2.2, and also can be configured
5176 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5179 * Improvements in C++ mangling/demangling.
5181 This release has much better g++ debugging, specifically in name
5182 mangling/demangling, virtual function calls, print virtual table,
5183 call methods, ...etc.
5185 *** Changes in GDB-4.10:
5187 * User visible changes:
5189 Remote debugging using the GDB-specific (`target remote') protocol now
5190 supports the `load' command. This is only useful if you have some
5191 other way of getting the stub to the target system, and you can put it
5192 somewhere in memory where it won't get clobbered by the download.
5194 Filename completion now works.
5196 When run under emacs mode, the "info line" command now causes the
5197 arrow to point to the line specified. Also, "info line" prints
5198 addresses in symbolic form (as well as hex).
5200 All vxworks based targets now support a user settable option, called
5201 vxworks-timeout. This option represents the number of seconds gdb
5202 should wait for responses to rpc's. You might want to use this if
5203 your vxworks target is, perhaps, a slow software simulator or happens
5204 to be on the far side of a thin network line.
5208 This release contains support for using a DEC alpha as a GDB host for
5209 cross debugging. Native alpha debugging is not supported yet.
5212 *** Changes in GDB-4.9:
5216 This is the first GDB release which is accompanied by a matching testsuite.
5217 The testsuite requires installation of dejagnu, which should be available
5218 via ftp from most sites that carry GNU software.
5222 'Cfront' style demangling has had its name changed to 'ARM' style, to
5223 emphasize that it was written from the specifications in the C++ Annotated
5224 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5225 disclaimers, it still generated too much confusion with users attempting to
5226 use gdb with AT&T cfront.
5230 GDB now uses a standard remote interface to a simulator library.
5231 So far, the library contains simulators for the Zilog Z8001/2, the
5232 Hitachi H8/300, H8/500 and Super-H.
5234 * New targets supported
5236 H8/300 simulator h8300-hitachi-hms or h8300hms
5237 H8/500 simulator h8500-hitachi-hms or h8500hms
5238 SH simulator sh-hitachi-hms or sh
5239 Z8000 simulator z8k-zilog-none or z8ksim
5240 IDT MIPS board over serial line mips-idt-ecoff
5242 Cross-debugging to GO32 targets is supported. It requires a custom
5243 version of the i386-stub.c module which is integrated with the
5244 GO32 memory extender.
5246 * New remote protocols
5248 MIPS remote debugging protocol.
5250 * New source languages supported
5252 This version includes preliminary support for Chill, a Pascal like language
5253 used by telecommunications companies. Chill support is also being integrated
5254 into the GNU compiler, but we don't know when it will be publically available.
5257 *** Changes in GDB-4.8:
5259 * HP Precision Architecture supported
5261 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5262 version of this support was available as a set of patches from the
5263 University of Utah. GDB does not support debugging of programs
5264 compiled with the HP compiler, because HP will not document their file
5265 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5266 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5268 Many problems in the preliminary version have been fixed.
5270 * Faster and better demangling
5272 We have improved template demangling and fixed numerous bugs in the GNU style
5273 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5274 character types (wchar_t) are now supported. Demangling of each symbol is now
5275 only done once, and is cached when the symbol table for a file is read in.
5276 This results in a small increase in memory usage for C programs, a moderate
5277 increase in memory usage for C++ programs, and a fantastic speedup in
5280 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5281 from the specifications in the Annotated Reference Manual, which AT&T's
5282 compiler does not actually implement.
5284 * G++ multiple inheritance compiler problem
5286 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5287 inheritance lattices was reworked to properly discover ambiguities. We
5288 recently found an example which causes this new algorithm to fail in a
5289 very subtle way, producing bad debug information for those classes.
5290 The file 'gcc.patch' (in this directory) can be applied to gcc to
5291 circumvent the problem. A future GCC release will contain a complete
5294 The previous G++ debug info problem (mentioned below for the gdb-4.7
5295 release) is fixed in gcc version 2.3.2.
5297 * Improved configure script
5299 The `configure' script will now attempt to guess your system type if
5300 you don't supply a host system type. The old scheme of supplying a
5301 host system triplet is preferable over using this. All the magic is
5302 done in the new `config.guess' script. Examine it for details.
5304 We have also brought our configure script much more in line with the FSF's
5305 version. It now supports the --with-xxx options. In particular,
5306 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5307 The resulting GDB will not be able to read arbitrary object file formats --
5308 only the format ``expected'' to be used on the configured target system.
5309 We hope to make this the default in a future release.
5311 * Documentation improvements
5313 There's new internal documentation on how to modify GDB, and how to
5314 produce clean changes to the code. We implore people to read it
5315 before submitting changes.
5317 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5318 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5319 `info' files are also provided. To build `info' files from scratch,
5320 you will need the latest `makeinfo' release, which will be available in
5321 a future texinfo-X.Y release.
5323 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5324 We're not sure exactly which versions have this problem, but it has
5325 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5326 or better. If that isn't possible, there is a patch in
5327 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5328 around this problem.
5332 GDB now supports array constants that can be used in expressions typed in by
5333 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5334 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5337 The new directory `gdb/sparclite' contains a program that demonstrates
5338 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5340 * New native hosts supported
5342 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5343 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5345 * New targets supported
5347 AMD 29k family via UDI a29k-amd-udi or udi29k
5349 * New file formats supported
5351 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5352 HPUX core files, and SCO 3.2v2 core files.
5356 Attaching to processes now works again; thanks for the many bug reports.
5358 We have also stomped on a bunch of core dumps caused by
5359 printf_filtered("%s") problems.
5361 We eliminated a copyright problem on the rpc and ptrace header files
5362 for VxWorks, which was discovered at the last minute during the 4.7
5363 release. You should now be able to build a VxWorks GDB.
5365 You can now interrupt gdb while an attached process is running. This
5366 will cause the attached process to stop, and give control back to GDB.
5368 We fixed problems caused by using too many file descriptors
5369 for reading symbols from object files and libraries. This was
5370 especially a problem for programs that used many (~100) shared
5373 The `step' command now only enters a subroutine if there is line number
5374 information for the subroutine. Otherwise it acts like the `next'
5375 command. Previously, `step' would enter subroutines if there was
5376 any debugging information about the routine. This avoids problems
5377 when using `cc -g1' on MIPS machines.
5379 * Internal improvements
5381 GDB's internal interfaces have been improved to make it easier to support
5382 debugging of multiple languages in the future.
5384 GDB now uses a common structure for symbol information internally.
5385 Minimal symbols (derived from linkage symbols in object files), partial
5386 symbols (from a quick scan of debug information), and full symbols
5387 contain a common subset of information, making it easier to write
5388 shared code that handles any of them.
5390 * New command line options
5392 We now accept --silent as an alias for --quiet.
5396 The memory-mapped-malloc library is now licensed under the GNU Library
5397 General Public License.
5399 *** Changes in GDB-4.7:
5401 * Host/native/target split
5403 GDB has had some major internal surgery to untangle the support for
5404 hosts and remote targets. Now, when you configure GDB for a remote
5405 target, it will no longer load in all of the support for debugging
5406 local programs on the host. When fully completed and tested, this will
5407 ensure that arbitrary host/target combinations are possible.
5409 The primary conceptual shift is to separate the non-portable code in
5410 GDB into three categories. Host specific code is required any time GDB
5411 is compiled on that host, regardless of the target. Target specific
5412 code relates to the peculiarities of the target, but can be compiled on
5413 any host. Native specific code is everything else: it can only be
5414 built when the host and target are the same system. Child process
5415 handling and core file support are two common `native' examples.
5417 GDB's use of /proc for controlling Unix child processes is now cleaner.
5418 It has been split out into a single module under the `target_ops' vector,
5419 plus two native-dependent functions for each system that uses /proc.
5421 * New hosts supported
5423 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5424 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5425 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5427 * New targets supported
5429 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5430 68030 and CPU32 m68030-*-*, m68332-*-*
5432 * New native hosts supported
5434 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5435 (386bsd is not well tested yet)
5436 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5438 * New file formats supported
5440 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5441 supports reading of `a.out.adobe' object files, which are an a.out
5442 format extended with minimal information about multiple sections.
5446 `show copying' is the same as the old `info copying'.
5447 `show warranty' is the same as `info warrantee'.
5448 These were renamed for consistency. The old commands continue to work.
5450 `info handle' is a new alias for `info signals'.
5452 You can now define pre-command hooks, which attach arbitrary command
5453 scripts to any command. The commands in the hook will be executed
5454 prior to the user's command. You can also create a hook which will be
5455 executed whenever the program stops. See gdb.texinfo.
5459 We now deal with Cfront style name mangling, and can even extract type
5460 info from mangled symbols. GDB can automatically figure out which
5461 symbol mangling style your C++ compiler uses.
5463 Calling of methods and virtual functions has been improved as well.
5467 The crash that occured when debugging Sun Ansi-C compiled binaries is
5468 fixed. This was due to mishandling of the extra N_SO stabs output
5471 We also finally got Ultrix 4.2 running in house, and fixed core file
5472 support, with help from a dozen people on the net.
5474 John M. Farrell discovered that the reason that single-stepping was so
5475 slow on all of the Mips based platforms (primarily SGI and DEC) was
5476 that we were trying to demangle and lookup a symbol used for internal
5477 purposes on every instruction that was being stepped through. Changing
5478 the name of that symbol so that it couldn't be mistaken for a C++
5479 mangled symbol sped things up a great deal.
5481 Rich Pixley sped up symbol lookups in general by getting much smarter
5482 about when C++ symbol mangling is necessary. This should make symbol
5483 completion (TAB on the command line) much faster. It's not as fast as
5484 we'd like, but it's significantly faster than gdb-4.6.
5488 A new user controllable variable 'call_scratch_address' can
5489 specify the location of a scratch area to be used when GDB
5490 calls a function in the target. This is necessary because the
5491 usual method of putting the scratch area on the stack does not work
5492 in systems that have separate instruction and data spaces.
5494 We integrated changes to support the 29k UDI (Universal Debugger
5495 Interface), but discovered at the last minute that we didn't have all
5496 of the appropriate copyright paperwork. We are working with AMD to
5497 resolve this, and hope to have it available soon.
5501 We have sped up the remote serial line protocol, especially for targets
5502 with lots of registers. It now supports a new `expedited status' ('T')
5503 message which can be used in place of the existing 'S' status message.
5504 This allows the remote stub to send only the registers that GDB
5505 needs to make a quick decision about single-stepping or conditional
5506 breakpoints, eliminating the need to fetch the entire register set for
5507 each instruction being stepped through.
5509 The GDB remote serial protocol now implements a write-through cache for
5510 registers, only re-reading the registers if the target has run.
5512 There is also a new remote serial stub for SPARC processors. You can
5513 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5514 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5515 processor with a serial port.
5519 Configure.in files have become much easier to read and modify. A new
5520 `table driven' format makes it more obvious what configurations are
5521 supported, and what files each one uses.
5525 There is a new opcodes library which will eventually contain all of the
5526 disassembly routines and opcode tables. At present, it only contains
5527 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5528 disassembler (binutils/objdump) to share these routines.
5530 The libiberty library is now copylefted under the GNU Library General
5531 Public License. This allows more liberal use, and was done so libg++
5532 can use it. This makes no difference to GDB, since the Library License
5533 grants all the rights from the General Public License.
5537 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5538 reference to the stabs symbol info used by the debugger. It is (as far
5539 as we know) the only published document on this fascinating topic. We
5540 encourage you to read it, compare it to the stabs information on your
5541 system, and send improvements on the document in general (to
5542 bug-gdb@prep.ai.mit.edu).
5544 And, of course, many bugs have been fixed.
5547 *** Changes in GDB-4.6:
5549 * Better support for C++ function names
5551 GDB now accepts as input the "demangled form" of C++ overloaded function
5552 names and member function names, and can do command completion on such names
5553 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5554 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5555 Make use of command completion, it is your friend.
5557 GDB also now accepts a variety of C++ mangled symbol formats. They are
5558 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5559 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5560 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5561 for the list of formats.
5563 * G++ symbol mangling problem
5565 Recent versions of gcc have a bug in how they emit debugging information for
5566 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5567 directory) can be applied to gcc to fix the problem. Alternatively, if you
5568 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5569 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5570 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5573 * New 'maintenance' command
5575 All of the commands related to hacking GDB internals have been moved out of
5576 the main command set, and now live behind the 'maintenance' command. This
5577 can also be abbreviated as 'mt'. The following changes were made:
5579 dump-me -> maintenance dump-me
5580 info all-breakpoints -> maintenance info breakpoints
5581 printmsyms -> maintenance print msyms
5582 printobjfiles -> maintenance print objfiles
5583 printpsyms -> maintenance print psymbols
5584 printsyms -> maintenance print symbols
5586 The following commands are new:
5588 maintenance demangle Call internal GDB demangler routine to
5589 demangle a C++ link name and prints the result.
5590 maintenance print type Print a type chain for a given symbol
5592 * Change to .gdbinit file processing
5594 We now read the $HOME/.gdbinit file before processing the argv arguments
5595 (e.g. reading symbol files or core files). This allows global parameters to
5596 be set, which will apply during the symbol reading. The ./.gdbinit is still
5597 read after argv processing.
5599 * New hosts supported
5601 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5603 GNU/Linux support i386-unknown-linux or linux
5605 We are also including code to support the HP/PA running BSD and HPUX. This
5606 is almost guaranteed not to work, as we didn't have time to test or build it
5607 for this release. We are including it so that the more adventurous (or
5608 masochistic) of you can play with it. We also had major problems with the
5609 fact that the compiler that we got from HP doesn't support the -g option.
5612 * New targets supported
5614 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5616 * More smarts about finding #include files
5618 GDB now remembers the compilation directory for all include files, and for
5619 all files from which C is generated (like yacc and lex sources). This
5620 greatly improves GDB's ability to find yacc/lex sources, and include files,
5621 especially if you are debugging your program from a directory different from
5622 the one that contains your sources.
5624 We also fixed a bug which caused difficulty with listing and setting
5625 breakpoints in include files which contain C code. (In the past, you had to
5626 try twice in order to list an include file that you hadn't looked at before.)
5628 * Interesting infernals change
5630 GDB now deals with arbitrary numbers of sections, where the symbols for each
5631 section must be relocated relative to that section's landing place in the
5632 target's address space. This work was needed to support ELF with embedded
5633 stabs used by Solaris-2.0.
5635 * Bug fixes (of course!)
5637 There have been loads of fixes for the following things:
5638 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5639 i960, stabs, DOS(GO32), procfs, etc...
5641 See the ChangeLog for details.
5643 *** Changes in GDB-4.5:
5645 * New machines supported (host and target)
5647 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5649 SGI Irix-4.x mips-sgi-irix4 or iris4
5651 * New malloc package
5653 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5654 Mmalloc is capable of handling mutiple heaps of memory. It is also
5655 capable of saving a heap to a file, and then mapping it back in later.
5656 This can be used to greatly speedup the startup of GDB by using a
5657 pre-parsed symbol table which lives in a mmalloc managed heap. For
5658 more details, please read mmalloc/mmalloc.texi.
5662 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5663 'help info proc' for details.
5665 * MIPS ecoff symbol table format
5667 The code that reads MIPS symbol table format is now supported on all hosts.
5668 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5671 * File name changes for MS-DOS
5673 Many files in the config directories have been renamed to make it easier to
5674 support GDB on MS-DOSe systems (which have very restrictive file name
5675 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5676 environment) is close to working but has some remaining problems. Note
5677 that debugging of DOS programs is not supported, due to limitations
5678 in the ``operating system'', but it can be used to host cross-debugging.
5680 * Cross byte order fixes
5682 Many fixes have been made to support cross debugging of Sparc and MIPS
5683 targets from hosts whose byte order differs.
5685 * New -mapped and -readnow options
5687 If memory-mapped files are available on your system through the 'mmap'
5688 system call, you can use the -mapped option on the `file' or
5689 `symbol-file' commands to cause GDB to write the symbols from your
5690 program into a reusable file. If the program you are debugging is
5691 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5692 Future GDB debugging sessions will notice the presence of this file,
5693 and will quickly map in symbol information from it, rather than reading
5694 the symbol table from the executable program. Using the '-mapped'
5695 option in a GDB `file' or `symbol-file' command has the same effect as
5696 starting GDB with the '-mapped' command-line option.
5698 You can cause GDB to read the entire symbol table immediately by using
5699 the '-readnow' option with any of the commands that load symbol table
5700 information (or on the GDB command line). This makes the command
5701 slower, but makes future operations faster.
5703 The -mapped and -readnow options are typically combined in order to
5704 build a `fred.syms' file that contains complete symbol information.
5705 A simple GDB invocation to do nothing but build a `.syms' file for future
5708 gdb -batch -nx -mapped -readnow programname
5710 The `.syms' file is specific to the host machine on which GDB is run.
5711 It holds an exact image of GDB's internal symbol table. It cannot be
5712 shared across multiple host platforms.
5714 * longjmp() handling
5716 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5717 siglongjmp() without losing control. This feature has not yet been ported to
5718 all systems. It currently works on many 386 platforms, all MIPS-based
5719 platforms (SGI, DECstation, etc), and Sun3/4.
5723 Preliminary work has been put in to support the new Solaris OS from Sun. At
5724 this time, it can control and debug processes, but it is not capable of
5729 As always, many many bug fixes. The major areas were with g++, and mipsread.
5730 People using the MIPS-based platforms should experience fewer mysterious
5731 crashes and trashed symbol tables.
5733 *** Changes in GDB-4.4:
5735 * New machines supported (host and target)
5737 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5739 BSD Reno on Vax vax-dec-bsd
5740 Ultrix on Vax vax-dec-ultrix
5742 * New machines supported (target)
5744 AMD 29000 embedded, using EBMON a29k-none-none
5748 GDB continues to improve its handling of C++. `References' work better.
5749 The demangler has also been improved, and now deals with symbols mangled as
5750 per the Annotated C++ Reference Guide.
5752 GDB also now handles `stabs' symbol information embedded in MIPS
5753 `ecoff' symbol tables. Since the ecoff format was not easily
5754 extensible to handle new languages such as C++, this appeared to be a
5755 good way to put C++ debugging info into MIPS binaries. This option
5756 will be supported in the GNU C compiler, version 2, when it is
5759 * New features for SVR4
5761 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5762 shared libraries. Debugging dynamically linked programs should present
5763 only minor differences from debugging statically linked programs.
5765 The `info proc' command will print out information about any process
5766 on an SVR4 system (including the one you are debugging). At the moment,
5767 it prints the address mappings of the process.
5769 If you bring up GDB on another SVR4 system, please send mail to
5770 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5772 * Better dynamic linking support in SunOS
5774 Reading symbols from shared libraries which contain debugging symbols
5775 now works properly. However, there remain issues such as automatic
5776 skipping of `transfer vector' code during function calls, which
5777 make it harder to debug code in a shared library, than to debug the
5778 same code linked statically.
5782 GDB is now using the latest `getopt' routines from the FSF. This
5783 version accepts the -- prefix for options with long names. GDB will
5784 continue to accept the old forms (-option and +option) as well.
5785 Various single letter abbreviations for options have been explicity
5786 added to the option table so that they won't get overshadowed in the
5787 future by other options that begin with the same letter.
5791 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5792 Many assorted bugs have been handled. Many more remain to be handled.
5793 See the various ChangeLog files (primarily in gdb and bfd) for details.
5796 *** Changes in GDB-4.3:
5798 * New machines supported (host and target)
5800 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5801 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5802 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5804 * Almost SCO Unix support
5806 We had hoped to support:
5807 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5808 (except for core file support), but we discovered very late in the release
5809 that it has problems with process groups that render gdb unusable. Sorry
5810 about that. I encourage people to fix it and post the fixes.
5812 * Preliminary ELF and DWARF support
5814 GDB can read ELF object files on System V Release 4, and can handle
5815 debugging records for C, in DWARF format, in ELF files. This support
5816 is preliminary. If you bring up GDB on another SVR4 system, please
5817 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5822 GDB now uses the latest `readline' library. One user-visible change
5823 is that two tabs will list possible command completions, which previously
5824 required typing M-? (meta-question mark, or ESC ?).
5828 The `stepi' bug that many of you noticed has been squashed.
5829 Many bugs in C++ have been handled. Many more remain to be handled.
5830 See the various ChangeLog files (primarily in gdb and bfd) for details.
5832 * State of the MIPS world (in case you wondered):
5834 GDB can understand the symbol tables emitted by the compilers
5835 supplied by most vendors of MIPS-based machines, including DEC. These
5836 symbol tables are in a format that essentially nobody else uses.
5838 Some versions of gcc come with an assembler post-processor called
5839 mips-tfile. This program is required if you want to do source-level
5840 debugging of gcc-compiled programs. I believe FSF does not ship
5841 mips-tfile with gcc version 1, but it will eventually come with gcc
5844 Debugging of g++ output remains a problem. g++ version 1.xx does not
5845 really support it at all. (If you're lucky, you should be able to get
5846 line numbers and stack traces to work, but no parameters or local
5847 variables.) With some work it should be possible to improve the
5850 When gcc version 2 is released, you will have somewhat better luck.
5851 However, even then you will get confusing results for inheritance and
5854 We will eventually provide full debugging of g++ output on
5855 DECstations. This will probably involve some kind of stabs-in-ecoff
5856 encapulation, but the details have not been worked out yet.
5859 *** Changes in GDB-4.2:
5861 * Improved configuration
5863 Only one copy of `configure' exists now, and it is not self-modifying.
5864 Porting BFD is simpler.
5868 The `step' and `next' commands now only stop at the first instruction
5869 of a source line. This prevents the multiple stops that used to occur
5870 in switch statements, for-loops, etc. `Step' continues to stop if a
5871 function that has debugging information is called within the line.
5875 Lots of small bugs fixed. More remain.
5877 * New host supported (not target)
5879 Intel 386 PC clone running Mach i386-none-mach
5882 *** Changes in GDB-4.1:
5884 * Multiple source language support
5886 GDB now has internal scaffolding to handle several source languages.
5887 It determines the type of each source file from its filename extension,
5888 and will switch expression parsing and number formatting to match the
5889 language of the function in the currently selected stack frame.
5890 You can also specifically set the language to be used, with
5891 `set language c' or `set language modula-2'.
5895 GDB now has preliminary support for the GNU Modula-2 compiler,
5896 currently under development at the State University of New York at
5897 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5898 continue through the fall of 1991 and into 1992.
5900 Other Modula-2 compilers are currently not supported, and attempting to
5901 debug programs compiled with them will likely result in an error as the
5902 symbol table is read. Feel free to work on it, though!
5904 There are hooks in GDB for strict type checking and range checking,
5905 in the `Modula-2 philosophy', but they do not currently work.
5909 GDB can now write to executable and core files (e.g. patch
5910 a variable's value). You must turn this switch on, specify
5911 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5912 by assigning a new value to a variable. Modifications take
5915 * Automatic SunOS shared library reading
5917 When you run your program, GDB automatically determines where its
5918 shared libraries (if any) have been loaded, and reads their symbols.
5919 The `share' command is no longer needed. This also works when
5920 examining core files.
5924 You can specify the number of lines that the `list' command shows.
5927 * New machines supported (host and target)
5929 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5930 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5931 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5933 * New hosts supported (not targets)
5935 IBM RT/PC: romp-ibm-aix or rtpc
5937 * New targets supported (not hosts)
5939 AMD 29000 embedded with COFF a29k-none-coff
5940 AMD 29000 embedded with a.out a29k-none-aout
5941 Ultracomputer remote kernel debug a29k-nyu-kern
5943 * New remote interfaces
5949 *** Changes in GDB-4.0:
5953 Wide output is wrapped at good places to make the output more readable.
5955 Gdb now supports cross-debugging from a host machine of one type to a
5956 target machine of another type. Communication with the target system
5957 is over serial lines. The ``target'' command handles connecting to the
5958 remote system; the ``load'' command will download a program into the
5959 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5960 also supports debugging of realtime processes running under VxWorks,
5961 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5962 stub on the target system.
5964 New CPUs supported include the AMD 29000 and Intel 960.
5966 GDB now reads object files and symbol tables via a ``binary file''
5967 library, which allows a single copy of GDB to debug programs of multiple
5968 object file types such as a.out and coff.
5970 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5971 refcard.dvi and refcard.ps are available to format it).
5974 * Control-Variable user interface simplified
5976 All variables that control the operation of the debugger can be set
5977 by the ``set'' command, and displayed by the ``show'' command.
5979 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5980 ``Show prompt'' produces the response:
5981 Gdb's prompt is new-gdb=>.
5983 What follows are the NEW set commands. The command ``help set'' will
5984 print a complete list of old and new set commands. ``help set FOO''
5985 will give a longer description of the variable FOO. ``show'' will show
5986 all of the variable descriptions and their current settings.
5988 confirm on/off: Enables warning questions for operations that are
5989 hard to recover from, e.g. rerunning the program while
5990 it is already running. Default is ON.
5992 editing on/off: Enables EMACS style command line editing
5993 of input. Previous lines can be recalled with
5994 control-P, the current line can be edited with control-B,
5995 you can search for commands with control-R, etc.
5998 history filename NAME: NAME is where the gdb command history
5999 will be stored. The default is .gdb_history,
6000 or the value of the environment variable
6003 history size N: The size, in commands, of the command history. The
6004 default is 256, or the value of the environment variable
6007 history save on/off: If this value is set to ON, the history file will
6008 be saved after exiting gdb. If set to OFF, the
6009 file will not be saved. The default is OFF.
6011 history expansion on/off: If this value is set to ON, then csh-like
6012 history expansion will be performed on
6013 command line input. The default is OFF.
6015 radix N: Sets the default radix for input and output. It can be set
6016 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6017 in the current radix, so "set radix 10" is always a no-op.
6019 height N: This integer value is the number of lines on a page. Default
6020 is 24, the current `stty rows'' setting, or the ``li#''
6021 setting from the termcap entry matching the environment
6024 width N: This integer value is the number of characters on a line.
6025 Default is 80, the current `stty cols'' setting, or the ``co#''
6026 setting from the termcap entry matching the environment
6029 Note: ``set screensize'' is obsolete. Use ``set height'' and
6030 ``set width'' instead.
6032 print address on/off: Print memory addresses in various command displays,
6033 such as stack traces and structure values. Gdb looks
6034 more ``symbolic'' if you turn this off; it looks more
6035 ``machine level'' with it on. Default is ON.
6037 print array on/off: Prettyprint arrays. New convenient format! Default
6040 print demangle on/off: Print C++ symbols in "source" form if on,
6043 print asm-demangle on/off: Same, for assembler level printouts
6046 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6049 * Support for Epoch Environment.
6051 The epoch environment is a version of Emacs v18 with windowing. One
6052 new command, ``inspect'', is identical to ``print'', except that if you
6053 are running in the epoch environment, the value is printed in its own
6057 * Support for Shared Libraries
6059 GDB can now debug programs and core files that use SunOS shared libraries.
6060 Symbols from a shared library cannot be referenced
6061 before the shared library has been linked with the program (this
6062 happens after you type ``run'' and before the function main() is entered).
6063 At any time after this linking (including when examining core files
6064 from dynamically linked programs), gdb reads the symbols from each
6065 shared library when you type the ``sharedlibrary'' command.
6066 It can be abbreviated ``share''.
6068 sharedlibrary REGEXP: Load shared object library symbols for files
6069 matching a unix regular expression. No argument
6070 indicates to load symbols for all shared libraries.
6072 info sharedlibrary: Status of loaded shared libraries.
6077 A watchpoint stops execution of a program whenever the value of an
6078 expression changes. Checking for this slows down execution
6079 tremendously whenever you are in the scope of the expression, but is
6080 quite useful for catching tough ``bit-spreader'' or pointer misuse
6081 problems. Some machines such as the 386 have hardware for doing this
6082 more quickly, and future versions of gdb will use this hardware.
6084 watch EXP: Set a watchpoint (breakpoint) for an expression.
6086 info watchpoints: Information about your watchpoints.
6088 delete N: Deletes watchpoint number N (same as breakpoints).
6089 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6090 enable N: Re-enables watchpoint number N (same as breakpoints).
6093 * C++ multiple inheritance
6095 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6098 * C++ exception handling
6100 Gdb now supports limited C++ exception handling. Besides the existing
6101 ability to breakpoint on an exception handler, gdb can breakpoint on
6102 the raising of an exception (before the stack is peeled back to the
6105 catch FOO: If there is a FOO exception handler in the dynamic scope,
6106 set a breakpoint to catch exceptions which may be raised there.
6107 Multiple exceptions (``catch foo bar baz'') may be caught.
6109 info catch: Lists all exceptions which may be caught in the
6110 current stack frame.
6113 * Minor command changes
6115 The command ``call func (arg, arg, ...)'' now acts like the print
6116 command, except it does not print or save a value if the function's result
6117 is void. This is similar to dbx usage.
6119 The ``up'' and ``down'' commands now always print the frame they end up
6120 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6121 frames without printing.
6123 * New directory command
6125 'dir' now adds directories to the FRONT of the source search path.
6126 The path starts off empty. Source files that contain debug information
6127 about the directory in which they were compiled can be found even
6128 with an empty path; Sun CC and GCC include this information. If GDB can't
6129 find your source file in the current directory, type "dir .".
6131 * Configuring GDB for compilation
6133 For normal use, type ``./configure host''. See README or gdb.texinfo
6136 GDB now handles cross debugging. If you are remotely debugging between
6137 two different machines, type ``./configure host -target=targ''.
6138 Host is the machine where GDB will run; targ is the machine
6139 where the program that you are debugging will run.