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.
71 ** Memory ports can now be unbuffered.
75 ** gdb.Objfile objects have a new attribute "username",
76 which is the name of the objfile as specified by the user,
77 without, for example, resolving symlinks.
78 ** You can now write frame unwinders in Python.
79 ** gdb.Type objects have a new method "optimized_out",
80 returning optimized out gdb.Value instance of this type.
81 ** gdb.Value objects have new methods "reference_value" and
82 "const_value" which return a reference to the value and a
83 "const" version of the value respectively.
87 maint print symbol-cache
88 Print the contents of the symbol cache.
90 maint print symbol-cache-statistics
91 Print statistics of symbol cache usage.
93 maint flush-symbol-cache
94 Flush the contents of the symbol cache.
98 Start branch trace recording using Branch Trace Store (BTS) format.
101 Evaluate expression by using the compiler and print result.
105 Explicit commands for enabling and disabling tui mode.
108 set mpx bound on i386 and amd64
109 Support for bound table investigation on Intel(R) MPX enabled applications.
114 Renamed from "set debug dwarf2-die".
116 Renamed from "show debug dwarf2-die".
119 Renamed from "set debug dwarf2-read".
120 show debug dwarf-read
121 Renamed from "show debug dwarf2-read".
123 maint set dwarf always-disassemble
124 Renamed from "maint set dwarf2 always-disassemble".
125 maint show dwarf always-disassemble
126 Renamed from "maint show dwarf2 always-disassemble".
128 maint set dwarf max-cache-age
129 Renamed from "maint set dwarf2 max-cache-age".
130 maint show dwarf max-cache-age
131 Renamed from "maint show dwarf2 max-cache-age".
134 show debug dwarf-line
135 Control display of debugging info regarding DWARF line processing.
139 Set the maximum number of candidates to be considered during
140 completion. The default value is 200. This limit allows GDB
141 to avoid generating large completion lists, the computation of
142 which can cause the debugger to become temporarily unresponsive.
144 maint set symbol-cache-size
145 maint show symbol-cache-size
146 Control the size of the symbol cache.
148 set|show record btrace bts buffer-size
149 Set and show the size of the ring buffer used for branch tracing in
151 The obtained size may differ from the requested size. Use "info
152 record" to see the obtained buffer size.
154 set debug linux-namespaces
155 show debug linux-namespaces
156 Control display of debugging info regarding Linux namespaces.
158 * The command 'thread apply all' can now support new option '-ascending'
159 to call its specified command for all threads in ascending order.
161 * Python/Guile scripting
163 ** GDB now supports auto-loading of Python/Guile scripts contained in the
164 special section named `.debug_gdb_scripts'.
168 qXfer:btrace-conf:read
169 Return the branch trace configuration for the current thread.
171 Qbtrace-conf:bts:size
172 Set the requested ring buffer size for branch tracing in BTS format.
175 Indicates a memory breakpoint instruction was executed, irrespective
176 of whether it was GDB that planted the breakpoint or the breakpoint
177 is hardcoded in the program. This is required for correct non-stop
181 Indicates the target stopped for a hardware breakpoint. This is
182 required for correct non-stop mode operation.
185 Return information about files on the remote system.
188 Return the full absolute name of the file that was executed to
189 create a process running on the remote system.
192 Select the filesystem on which vFile: operations with filename
193 arguments will operate. This is required for GDB to be able to
194 access files on remote targets where the remote stub does not
195 share a common filesystem with the inferior(s).
198 Indicates that a fork system call was executed.
201 Indicates that a vfork system call was executed.
203 vforkdone stop reason
204 Indicates that a vfork child of the specified process has executed
205 an exec or exit, allowing the vfork parent to resume execution.
207 fork-events and vfork-events features in qSupported
208 The qSupported packet allows GDB to request support for fork and
209 vfork events using new 'gdbfeatures' fork-events and vfork-events,
210 and the qSupported response can contain the corresponding
211 'stubfeatures'. Set and show commands can be used to display
212 whether these features are enabled.
214 * Extended-remote fork events
216 ** GDB now has support for fork events on extended-remote Linux
217 targets. For targets with Linux kernels 2.5.60 and later, this
218 enables follow-fork-mode and detach-on-fork for both fork and
219 vfork, as well as fork and vfork catchpoints.
221 * The info record command now shows the recording format and the
222 branch tracing configuration for the current thread when using
223 the btrace record target.
224 For the BTS format, it shows the ring buffer size.
226 * GDB now has support for DTrace USDT (Userland Static Defined
227 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
229 * GDB now supports access to vector registers on S/390 GNU/Linux
232 * Removed command line options
234 -xdb HP-UX XDB compatibility mode.
236 * Removed targets and native configurations
238 HP/PA running HP-UX hppa*-*-hpux*
239 Itanium running HP-UX ia64-*-hpux*
241 *** Changes in GDB 7.9.1
245 ** Xmethods can now specify a result type.
247 *** Changes in GDB 7.9
249 * GDB now supports hardware watchpoints on x86 GNU Hurd.
253 ** You can now access frame registers from Python scripts.
254 ** New attribute 'producer' for gdb.Symtab objects.
255 ** gdb.Objfile objects have a new attribute "progspace",
256 which is the gdb.Progspace object of the containing program space.
257 ** gdb.Objfile objects have a new attribute "owner".
258 ** gdb.Objfile objects have a new attribute "build_id",
259 which is the build ID generated when the file was built.
260 ** gdb.Objfile objects have a new method "add_separate_debug_file".
261 ** A new event "gdb.clear_objfiles" has been added, triggered when
262 selecting a new file to debug.
263 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
264 ** New function gdb.lookup_objfile.
266 New events which are triggered when GDB modifies the state of the
269 ** gdb.events.inferior_call_pre: Function call is about to be made.
270 ** gdb.events.inferior_call_post: Function call has just been made.
271 ** gdb.events.memory_changed: A memory location has been altered.
272 ** gdb.events.register_changed: A register has been altered.
274 * New Python-based convenience functions:
276 ** $_caller_is(name [, number_of_frames])
277 ** $_caller_matches(regexp [, number_of_frames])
278 ** $_any_caller_is(name [, number_of_frames])
279 ** $_any_caller_matches(regexp [, number_of_frames])
281 * GDB now supports the compilation and injection of source code into
282 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
283 to compile the source code to object code, and if successful, inject
284 and execute that code within the current context of the inferior.
285 Currently the C language is supported. The commands used to
286 interface with this new feature are:
288 compile code [-raw|-r] [--] [source code]
289 compile file [-raw|-r] filename
293 demangle [-l language] [--] name
294 Demangle "name" in the specified language, or the current language
295 if elided. This command is renamed from the "maint demangle" command.
296 The latter is kept as a no-op to avoid "maint demangle" being interpreted
297 as "maint demangler-warning".
299 queue-signal signal-name-or-number
300 Queue a signal to be delivered to the thread when it is resumed.
302 add-auto-load-scripts-directory directory
303 Add entries to the list of directories from which to load auto-loaded
306 maint print user-registers
307 List all currently available "user" registers.
309 compile code [-r|-raw] [--] [source code]
310 Compile, inject, and execute in the inferior the executable object
311 code produced by compiling the provided source code.
313 compile file [-r|-raw] filename
314 Compile and inject into the inferior the executable object code
315 produced by compiling the source code stored in the filename
318 * On resume, GDB now always passes the signal the program had stopped
319 for to the thread the signal was sent to, even if the user changed
320 threads before resuming. Previously GDB would often (but not
321 always) deliver the signal to the thread that happens to be current
324 * Conversely, the "signal" command now consistently delivers the
325 requested signal to the current thread. GDB now asks for
326 confirmation if the program had stopped for a signal and the user
327 switched threads meanwhile.
329 * "breakpoint always-inserted" modes "off" and "auto" merged.
331 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
332 won't remove breakpoints from the target until all threads stop,
333 even in non-stop mode. The "auto" mode has been removed, and "off"
334 is now the default mode.
338 set debug symbol-lookup
339 show debug symbol-lookup
340 Control display of debugging info regarding symbol lookup.
344 ** The -list-thread-groups command outputs an exit-code field for
345 inferiors that have exited.
349 MIPS SDE mips*-sde*-elf*
353 Support for these obsolete configurations has been removed.
355 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
356 SGI Irix-5.x mips-*-irix5*
357 SGI Irix-6.x mips-*-irix6*
358 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
359 VAX running Ultrix vax-*-ultrix*
361 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
362 and "assf"), have been removed. Use the "sharedlibrary" command, or
363 its alias "share", instead.
365 *** Changes in GDB 7.8
367 * New command line options
370 This is an alias for the --data-directory option.
372 * GDB supports printing and modifying of variable length automatic arrays
373 as specified in ISO C99.
375 * The ARM simulator now supports instruction level tracing
376 with or without disassembly.
380 GDB now has support for scripting using Guile. Whether this is
381 available is determined at configure time.
382 Guile version 2.0 or greater is required.
383 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
385 * New commands (for set/show, see "New options" below)
389 Invoke CODE by passing it to the Guile interpreter.
393 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
395 info auto-load guile-scripts [regexp]
396 Print the list of automatically loaded Guile scripts.
398 * The source command is now capable of sourcing Guile scripts.
399 This feature is dependent on the debugger being built with Guile support.
403 set print symbol-loading (off|brief|full)
404 show print symbol-loading
405 Control whether to print informational messages when loading symbol
406 information for a file. The default is "full", but when debugging
407 programs with large numbers of shared libraries the amount of output
410 set guile print-stack (none|message|full)
411 show guile print-stack
412 Show a stack trace when an error is encountered in a Guile script.
414 set auto-load guile-scripts (on|off)
415 show auto-load guile-scripts
416 Control auto-loading of Guile script files.
418 maint ada set ignore-descriptive-types (on|off)
419 maint ada show ignore-descriptive-types
420 Control whether the debugger should ignore descriptive types in Ada
421 programs. The default is not to ignore the descriptive types. See
422 the user manual for more details on descriptive types and the intended
423 usage of this option.
425 set auto-connect-native-target
427 Control whether GDB is allowed to automatically connect to the
428 native target for the run, attach, etc. commands when not connected
429 to any target yet. See also "target native" below.
431 set record btrace replay-memory-access (read-only|read-write)
432 show record btrace replay-memory-access
433 Control what memory accesses are allowed during replay.
435 maint set target-async (on|off)
436 maint show target-async
437 This controls whether GDB targets operate in synchronous or
438 asynchronous mode. Normally the default is asynchronous, if it is
439 available; but this can be changed to more easily debug problems
440 occurring only in synchronous mode.
442 set mi-async (on|off)
444 Control whether MI asynchronous mode is preferred. This supersedes
445 "set target-async" of previous GDB versions.
447 * "set target-async" is deprecated as a CLI option and is now an alias
448 for "set mi-async" (only puts MI into async mode).
450 * Background execution commands (e.g., "c&", "s&", etc.) are now
451 possible ``out of the box'' if the target supports them. Previously
452 the user would need to explicitly enable the possibility with the
453 "set target-async on" command.
455 * New features in the GDB remote stub, GDBserver
457 ** New option --debug-format=option1[,option2,...] allows one to add
458 additional text to each output. At present only timestamps
459 are supported: --debug-format=timestamps.
460 Timestamps can also be turned on with the
461 "monitor set debug-format timestamps" command from GDB.
463 * The 'record instruction-history' command now starts counting instructions
464 at one. This also affects the instruction ranges reported by the
465 'record function-call-history' command when given the /i modifier.
467 * The command 'record function-call-history' supports a new modifier '/c' to
468 indent the function names based on their call stack depth.
469 The fields for the '/i' and '/l' modifier have been reordered.
470 The source line range is now prefixed with 'at'.
471 The instruction range is now prefixed with 'inst'.
472 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
473 "record instruction-history" and "list" commands.
475 * The ranges given as arguments to the 'record function-call-history' and
476 'record instruction-history' commands are now inclusive.
478 * The btrace record target now supports the 'record goto' command.
479 For locations inside the execution trace, the back trace is computed
480 based on the information stored in the execution trace.
482 * The btrace record target supports limited reverse execution and replay.
483 The target does not record data and therefore does not allow reading
486 * The "catch syscall" command now works on s390*-linux* targets.
488 * The "compare-sections" command is no longer specific to target
489 remote. It now works with all targets.
491 * All native targets are now consistently called "native".
492 Consequently, the "target child", "target GNU", "target djgpp",
493 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
494 commands have been replaced with "target native". The QNX/NTO port
495 leaves the "procfs" target in place and adds a "native" target for
496 consistency with other ports. The impact on users should be minimal
497 as these commands previously either throwed an error, or were
498 no-ops. The target's name is visible in the output of the following
499 commands: "help target", "info target", "info files", "maint print
502 * The "target native" command now connects to the native target. This
503 can be used to launch native programs even when "set
504 auto-connect-native-target" is set to off.
506 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.
508 * Support for Intel(R) AVX-512 registers on GNU/Linux.
509 Support displaying and modifying Intel(R) AVX-512 registers
510 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
514 qXfer:btrace:read's annex
515 The qXfer:btrace:read packet supports a new annex 'delta' to read
516 branch trace incrementally.
520 ** Valid Python operations on gdb.Value objects representing
521 structs/classes invoke the corresponding overloaded operators if
523 ** New `Xmethods' feature in the Python API. Xmethods are
524 additional methods or replacements for existing methods of a C++
525 class. This feature is useful for those cases where a method
526 defined in C++ source code could be inlined or optimized out by
527 the compiler, making it unavailable to GDB.
530 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
532 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
533 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
534 its alias "share", instead.
536 * The commands "set remotebaud" and "show remotebaud" are no longer
537 supported. Use "set serial baud" and "show serial baud" (respectively)
542 ** A new option "-gdb-set mi-async" replaces "-gdb-set
543 target-async". The latter is left as a deprecated alias of the
544 former for backward compatibility. If the target supports it,
545 CLI background execution commands are now always possible by
546 default, independently of whether the frontend stated a
547 preference for asynchronous execution with "-gdb-set mi-async".
548 Previously "-gdb-set target-async off" affected both MI execution
549 commands and CLI execution commands.
551 *** Changes in GDB 7.7
553 * Improved support for process record-replay and reverse debugging on
554 arm*-linux* targets. Support for thumb32 and syscall instruction
555 recording has been added.
557 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
559 * GDB now supports Fission DWP file format version 2.
560 http://gcc.gnu.org/wiki/DebugFission
562 * New convenience function "$_isvoid", to check whether an expression
563 is void. A void expression is an expression where the type of the
564 result is "void". For example, some convenience variables may be
565 "void" when evaluated (e.g., "$_exitcode" before the execution of
566 the program being debugged; or an undefined convenience variable).
567 Another example, when calling a function whose return type is
570 * The "maintenance print objfiles" command now takes an optional regexp.
572 * The "catch syscall" command now works on arm*-linux* targets.
574 * GDB now consistently shows "<not saved>" when printing values of
575 registers the debug info indicates have not been saved in the frame
576 and there's nowhere to retrieve them from
577 (callee-saved/call-clobbered registers):
582 (gdb) info registers rax
585 Before, the former would print "<optimized out>", and the latter
586 "*value not available*".
588 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
593 ** Frame filters and frame decorators have been added.
594 ** Temporary breakpoints are now supported.
595 ** Line tables representation has been added.
596 ** New attribute 'parent_type' for gdb.Field objects.
597 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
598 ** New attribute 'name' for gdb.Type objects.
602 Nios II ELF nios2*-*-elf
603 Nios II GNU/Linux nios2*-*-linux
604 Texas Instruments MSP430 msp430*-*-elf
606 * Removed native configurations
608 Support for these a.out NetBSD and OpenBSD obsolete configurations has
609 been removed. ELF variants of these configurations are kept supported.
611 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
612 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
613 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
614 i[34567]86-*-openbsd3.[0-3]
615 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
616 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
617 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
621 Like "catch throw", but catches a re-thrown exception.
623 Renamed from old "maint check-symtabs".
625 Perform consistency checks on symtabs.
627 Expand symtabs matching an optional regexp.
630 Display the details of GDB configure-time options.
632 maint set|show per-command
633 maint set|show per-command space
634 maint set|show per-command time
635 maint set|show per-command symtab
636 Enable display of per-command gdb resource usage.
638 remove-symbol-file FILENAME
639 remove-symbol-file -a ADDRESS
640 Remove a symbol file added via add-symbol-file. The file to remove
641 can be identified by its filename or by an address that lies within
642 the boundaries of this symbol file in memory.
645 info exceptions REGEXP
646 Display the list of Ada exceptions defined in the program being
647 debugged. If provided, only the exceptions whose names match REGEXP
652 set debug symfile off|on
654 Control display of debugging info regarding reading symbol files and
655 symbol tables within those files
657 set print raw frame-arguments
658 show print raw frame-arguments
659 Set/show whether to print frame arguments in raw mode,
660 disregarding any defined pretty-printers.
662 set remote trace-status-packet
663 show remote trace-status-packet
664 Set/show the use of remote protocol qTStatus packet.
668 Control display of debugging messages related to Nios II targets.
672 Control whether target-assisted range stepping is enabled.
674 set startup-with-shell
675 show startup-with-shell
676 Specifies whether Unix child processes are started via a shell or
681 Use the target memory cache for accesses to the code segment. This
682 improves performance of remote debugging (particularly disassembly).
684 * You can now use a literal value 'unlimited' for options that
685 interpret 0 or -1 as meaning "unlimited". E.g., "set
686 trace-buffer-size unlimited" is now an alias for "set
687 trace-buffer-size -1" and "set height unlimited" is now an alias for
690 * The "set debug symtab-create" debugging option of GDB has been changed to
691 accept a verbosity level. 0 means "off", 1 provides basic debugging
692 output, and values of 2 or greater provides more verbose output.
694 * New command-line options
696 Display the details of GDB configure-time options.
698 * The command 'tsave' can now support new option '-ctf' to save trace
699 buffer in Common Trace Format.
701 * Newly installed $prefix/bin/gcore acts as a shell interface for the
704 * GDB now implements the the C++ 'typeid' operator.
706 * The new convenience variable $_exception holds the exception being
707 thrown or caught at an exception-related catchpoint.
709 * The exception-related catchpoints, like "catch throw", now accept a
710 regular expression which can be used to filter exceptions by type.
712 * The new convenience variable $_exitsignal is automatically set to
713 the terminating signal number when the program being debugged dies
714 due to an uncaught signal.
718 ** All MI commands now accept an optional "--language" option.
719 Support for this feature can be verified by using the "-list-features"
720 command, which should contain "language-option".
722 ** The new command -info-gdb-mi-command allows the user to determine
723 whether a GDB/MI command is supported or not.
725 ** The "^error" result record returned when trying to execute an undefined
726 GDB/MI command now provides a variable named "code" whose content is the
727 "undefined-command" error code. Support for this feature can be verified
728 by using the "-list-features" command, which should contain
729 "undefined-command-error-code".
731 ** The -trace-save MI command can optionally save trace buffer in Common
734 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
736 ** The command -data-list-register-values now accepts an optional
737 "--skip-unavailable" option. When used, only the available registers
740 ** The new command -trace-frame-collected dumps collected variables,
741 computed expressions, tvars, memory and registers in a traceframe.
743 ** The commands -stack-list-locals, -stack-list-arguments and
744 -stack-list-variables now accept an option "--skip-unavailable".
745 When used, only the available locals or arguments are displayed.
747 ** The -exec-run command now accepts an optional "--start" option.
748 When used, the command follows the same semantics as the "start"
749 command, stopping the program's execution at the start of its
750 main subprogram. Support for this feature can be verified using
751 the "-list-features" command, which should contain
752 "exec-run-start-option".
754 ** The new commands -catch-assert and -catch-exceptions insert
755 catchpoints stopping the program when Ada exceptions are raised.
757 ** The new command -info-ada-exceptions provides the equivalent of
758 the new "info exceptions" command.
760 * New system-wide configuration scripts
761 A GDB installation now provides scripts suitable for use as system-wide
762 configuration scripts for the following systems:
766 * GDB now supports target-assigned range stepping with remote targets.
767 This improves the performance of stepping source lines by reducing
768 the number of control packets from/to GDB. See "New remote packets"
771 * GDB now understands the element 'tvar' in the XML traceframe info.
772 It has the id of the collected trace state variables.
774 * On S/390 targets that provide the transactional-execution feature,
775 the program interruption transaction diagnostic block (TDB) is now
776 represented as a number of additional "registers" in GDB.
782 The vCont packet supports a new 'r' action, that tells the remote
783 stub to step through an address range itself, without GDB
784 involvemement at each single-step.
786 qXfer:libraries-svr4:read's annex
787 The previously unused annex of the qXfer:libraries-svr4:read packet
788 is now used to support passing an argument list. The remote stub
789 reports support for this argument list to GDB's qSupported query.
790 The defined arguments are "start" and "prev", used to reduce work
791 necessary for library list updating, resulting in significant
794 * New features in the GDB remote stub, GDBserver
796 ** GDBserver now supports target-assisted range stepping. Currently
797 enabled on x86/x86_64 GNU/Linux targets.
799 ** GDBserver now adds element 'tvar' in the XML in the reply to
800 'qXfer:traceframe-info:read'. It has the id of the collected
801 trace state variables.
803 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
806 * New 'z' formatter for printing and examining memory, this displays the
807 value as hexadecimal zero padded on the left to the size of the type.
809 * GDB can now use Windows x64 unwinding data.
811 * The "set remotebaud" command has been replaced by "set serial baud".
812 Similarly, "show remotebaud" has been replaced by "show serial baud".
813 The "set remotebaud" and "show remotebaud" commands are still available
814 to provide backward compatibility with older versions of GDB.
816 *** Changes in GDB 7.6
818 * Target record has been renamed to record-full.
819 Record/replay is now enabled with the "record full" command.
820 This also affects settings that are associated with full record/replay
821 that have been moved from "set/show record" to "set/show record full":
823 set|show record full insn-number-max
824 set|show record full stop-at-limit
825 set|show record full memory-query
827 * A new record target "record-btrace" has been added. The new target
828 uses hardware support to record the control-flow of a process. It
829 does not support replaying the execution, but it implements the
830 below new commands for investigating the recorded execution log.
831 This new recording method can be enabled using:
835 The "record-btrace" target is only available on Intel Atom processors
836 and requires a Linux kernel 2.6.32 or later.
838 * Two new commands have been added for record/replay to give information
839 about the recorded execution without having to replay the execution.
840 The commands are only supported by "record btrace".
842 record instruction-history prints the execution history at
843 instruction granularity
845 record function-call-history prints the execution history at
848 * New native configurations
850 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
851 FreeBSD/powerpc powerpc*-*-freebsd
852 x86_64/Cygwin x86_64-*-cygwin*
853 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
857 ARM AArch64 aarch64*-*-elf
858 ARM AArch64 GNU/Linux aarch64*-*-linux
859 Lynx 178 PowerPC powerpc-*-lynx*178
860 x86_64/Cygwin x86_64-*-cygwin*
861 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
863 * If the configured location of system.gdbinit file (as given by the
864 --with-system-gdbinit option at configure time) is in the
865 data-directory (as specified by --with-gdb-datadir at configure
866 time) or in one of its subdirectories, then GDB will look for the
867 system-wide init file in the directory specified by the
868 --data-directory command-line option.
870 * New command line options:
872 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
873 other initialization files, unlike -nx which disables all of them.
875 * Removed command line options
877 -epoch This was used by the gdb mode in Epoch, an ancient fork of
880 * The 'ptype' and 'whatis' commands now accept an argument to control
883 * 'info proc' now works on some core files.
887 ** Vectors can be created with gdb.Type.vector.
889 ** Python's atexit.register now works in GDB.
891 ** Types can be pretty-printed via a Python API.
893 ** Python 3 is now supported (in addition to Python 2.4 or later)
895 ** New class gdb.Architecture exposes GDB's internal representation
896 of architecture in the Python API.
898 ** New method Frame.architecture returns the gdb.Architecture object
899 corresponding to the frame's architecture.
901 * New Python-based convenience functions:
903 ** $_memeq(buf1, buf2, length)
904 ** $_streq(str1, str2)
906 ** $_regex(str, regex)
908 * The 'cd' command now defaults to using '~' (the home directory) if not
911 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
912 default for GCC since November 2000.
914 * The command 'forward-search' can now be abbreviated as 'fo'.
916 * The command 'info tracepoints' can now display 'installed on target'
917 or 'not installed on target' for each non-pending location of tracepoint.
919 * New configure options
921 --enable-libmcheck/--disable-libmcheck
922 By default, development versions are built with -lmcheck on hosts
923 that support it, in order to help track memory corruption issues.
924 Release versions, on the other hand, are built without -lmcheck
925 by default. The --enable-libmcheck/--disable-libmcheck configure
926 options allow the user to override that default.
927 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
928 This configure option allows the user to build GDB with
929 libbabeltrace using which GDB can read Common Trace Format data.
931 * New commands (for set/show, see "New options" below)
934 Catch signals. This is similar to "handle", but allows commands and
935 conditions to be attached.
938 List the BFDs known to GDB.
940 python-interactive [command]
942 Start a Python interactive prompt, or evaluate the optional command
943 and print the result of expressions.
946 "py" is a new alias for "python".
948 enable type-printer [name]...
949 disable type-printer [name]...
950 Enable or disable type printers.
954 ** For the Renesas Super-H architecture, the "regs" command has been removed
955 (has been deprecated in GDB 7.5), and "info all-registers" should be used
960 set print type methods (on|off)
961 show print type methods
962 Control whether method declarations are displayed by "ptype".
963 The default is to show them.
965 set print type typedefs (on|off)
966 show print type typedefs
967 Control whether typedef definitions are displayed by "ptype".
968 The default is to show them.
970 set filename-display basename|relative|absolute
971 show filename-display
972 Control the way in which filenames is displayed.
973 The default is "relative", which preserves previous behavior.
975 set trace-buffer-size
976 show trace-buffer-size
977 Request target to change the size of trace buffer.
979 set remote trace-buffer-size-packet auto|on|off
980 show remote trace-buffer-size-packet
981 Control the use of the remote protocol `QTBuffer:size' packet.
985 Control display of debugging messages related to ARM AArch64.
988 set debug coff-pe-read
989 show debug coff-pe-read
990 Control display of debugging messages related to reading of COFF/PE
995 Control display of debugging messages related to Mach-O symbols
998 set debug notification
999 show debug notification
1000 Control display of debugging info for async remote notification.
1004 ** Command parameter changes are now notified using new async record
1005 "=cmd-param-changed".
1006 ** Trace frame changes caused by command "tfind" are now notified using
1007 new async record "=traceframe-changed".
1008 ** The creation, deletion and modification of trace state variables
1009 are now notified using new async records "=tsv-created",
1010 "=tsv-deleted" and "=tsv-modified".
1011 ** The start and stop of process record are now notified using new
1012 async record "=record-started" and "=record-stopped".
1013 ** Memory changes are now notified using new async record
1015 ** The data-disassemble command response will include a "fullname" field
1016 containing the absolute file name when source has been requested.
1017 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1018 command, to allow pattern filling of memory areas.
1019 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1020 library load/unload events.
1021 ** The response to breakpoint commands and breakpoint async records
1022 includes an "installed" field containing a boolean state about each
1023 non-pending tracepoint location is whether installed on target or not.
1024 ** Output of the "-trace-status" command includes a "trace-file" field
1025 containing the name of the trace file being examined. This field is
1026 optional, and only present when examining a trace file.
1027 ** The "fullname" field is now always present along with the "file" field,
1028 even if the file cannot be found by GDB.
1030 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1031 You must have the LZMA library available when configuring GDB for this
1032 feature to be enabled. For more information, see:
1033 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1035 * New remote packets
1038 Set the size of trace buffer. The remote stub reports support for this
1039 packet to gdb's qSupported query.
1042 Enable Branch Trace Store (BTS)-based branch tracing for the current
1043 thread. The remote stub reports support for this packet to gdb's
1047 Disable branch tracing for the current thread. The remote stub reports
1048 support for this packet to gdb's qSupported query.
1051 Read the traced branches for the current thread. The remote stub
1052 reports support for this packet to gdb's qSupported query.
1054 *** Changes in GDB 7.5
1056 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1057 for more x32 ABI info.
1059 * GDB now supports access to MIPS DSP registers on Linux targets.
1061 * GDB now supports debugging microMIPS binaries.
1063 * The "info os" command on GNU/Linux can now display information on
1064 several new classes of objects managed by the operating system:
1065 "info os procgroups" lists process groups
1066 "info os files" lists file descriptors
1067 "info os sockets" lists internet-domain sockets
1068 "info os shm" lists shared-memory regions
1069 "info os semaphores" lists semaphores
1070 "info os msg" lists message queues
1071 "info os modules" lists loaded kernel modules
1073 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1074 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1075 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1076 options and inspect the probe arguments using the new $_probe_arg family
1077 of convenience variables. You can obtain more information about SystemTap
1078 in <http://sourceware.org/systemtap/>.
1080 * GDB now supports reversible debugging on ARM, it allows you to
1081 debug basic ARM and THUMB instructions, and provides
1082 record/replay support.
1084 * The option "symbol-reloading" has been deleted as it is no longer used.
1088 ** GDB commands implemented in Python can now be put in command class
1091 ** The "maint set python print-stack on|off" is now deleted.
1093 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1094 apply "flag enum"-style pretty-printing to any enum.
1096 ** gdb.lookup_symbol can now work when there is no current frame.
1098 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1099 the source at which the symbol was defined.
1101 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1102 method 'value'. The former indicates whether the symbol needs a
1103 frame in order to compute its value, and the latter computes the
1106 ** A new method 'referenced_value' on gdb.Value objects which can
1107 dereference pointer as well as C++ reference values.
1109 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1110 which return the global and static blocks (as gdb.Block objects),
1111 of the underlying symbol table, respectively.
1113 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1114 object associated with a PC value.
1116 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1117 of the address range occupied by code for the current source line.
1119 * Go language support.
1120 GDB now supports debugging programs written in the Go programming
1123 * GDBserver now supports stdio connections.
1124 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1126 * The binary "gdbtui" can no longer be built or installed.
1127 Use "gdb -tui" instead.
1129 * GDB will now print "flag" enums specially. A flag enum is one where
1130 all the enumerator values have no bits in common when pairwise
1131 "and"ed. When printing a value whose type is a flag enum, GDB will
1132 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1133 (gdb) print (enum E) 3
1136 * The filename part of a linespec will now match trailing components
1137 of a source file name. For example, "break gcc/expr.c:1000" will
1138 now set a breakpoint in build/gcc/expr.c, but not
1139 build/libcpp/expr.c.
1141 * The "info proc" and "generate-core-file" commands will now also
1142 work on remote targets connected to GDBserver on Linux.
1144 * The command "info catch" has been removed. It has been disabled
1145 since December 2007.
1147 * The "catch exception" and "catch assert" commands now accept
1148 a condition at the end of the command, much like the "break"
1149 command does. For instance:
1151 (gdb) catch exception Constraint_Error if Barrier = True
1153 Previously, it was possible to add a condition to such catchpoints,
1154 but it had to be done as a second step, after the catchpoint had been
1155 created, using the "condition" command.
1157 * The "info static-tracepoint-marker" command will now also work on
1158 native Linux targets with in-process agent.
1160 * GDB can now set breakpoints on inlined functions.
1162 * The .gdb_index section has been updated to include symbols for
1163 inlined functions. GDB will ignore older .gdb_index sections by
1164 default, which could cause symbol files to be loaded more slowly
1165 until their .gdb_index sections can be recreated. The new command
1166 "set use-deprecated-index-sections on" will cause GDB to use any older
1167 .gdb_index sections it finds. This will restore performance, but the
1168 ability to set breakpoints on inlined functions will be lost in symbol
1169 files with older .gdb_index sections.
1171 The .gdb_index section has also been updated to record more information
1172 about each symbol. This speeds up the "info variables", "info functions"
1173 and "info types" commands when used with programs having the .gdb_index
1174 section, as well as speeding up debugging with shared libraries using
1175 the .gdb_index section.
1177 * Ada support for GDB/MI Variable Objects has been added.
1179 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1184 ** New command -info-os is the MI equivalent of "info os".
1186 ** Output logs ("set logging" and related) now include MI output.
1190 ** "set use-deprecated-index-sections on|off"
1191 "show use-deprecated-index-sections on|off"
1192 Controls the use of deprecated .gdb_index sections.
1194 ** "catch load" and "catch unload" can be used to stop when a shared
1195 library is loaded or unloaded, respectively.
1197 ** "enable count" can be used to auto-disable a breakpoint after
1200 ** "info vtbl" can be used to show the virtual method tables for
1201 C++ and Java objects.
1203 ** "explore" and its sub commands "explore value" and "explore type"
1204 can be used to recursively explore values and types of
1205 expressions. These commands are available only if GDB is
1206 configured with '--with-python'.
1208 ** "info auto-load" shows status of all kinds of auto-loaded files,
1209 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1210 sequences of commands files, "info auto-load python-scripts"
1211 shows status of auto-loading Python script files,
1212 "info auto-load local-gdbinit" shows status of loading init file
1213 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1214 status of inferior specific thread debugging shared library loading.
1216 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1217 and "show auto-load-scripts" commands have been deprecated, use their
1218 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1219 and "show auto-load python-scripts" counterparts instead.
1221 ** "dprintf location,format,args..." creates a dynamic printf, which
1222 is basically a breakpoint that does a printf and immediately
1223 resumes your program's execution, so it is like a printf that you
1224 can insert dynamically at runtime instead of at compiletime.
1226 ** "set print symbol"
1228 Controls whether GDB attempts to display the symbol, if any,
1229 corresponding to addresses it prints. This defaults to "on", but
1230 you can set it to "off" to restore GDB's previous behavior.
1232 * Deprecated commands
1234 ** For the Renesas Super-H architecture, the "regs" command has been
1235 deprecated, and "info all-registers" should be used instead.
1239 Renesas RL78 rl78-*-elf
1240 HP OpenVMS ia64 ia64-hp-openvms*
1242 * GDBserver supports evaluation of breakpoint conditions. When
1243 support is advertised by GDBserver, GDB may be told to send the
1244 breakpoint conditions in bytecode form to GDBserver. GDBserver
1245 will only report the breakpoint trigger to GDB when its condition
1250 set mips compression
1251 show mips compression
1252 Select the compressed ISA encoding used in functions that have no symbol
1253 information available. The encoding can be set to either of:
1256 and is updated automatically from ELF file flags if available.
1258 set breakpoint condition-evaluation
1259 show breakpoint condition-evaluation
1260 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1261 GDBserver ("target"). Default option "auto" chooses the most efficient
1263 This option can improve debugger efficiency depending on the speed of the
1267 Disable auto-loading globally.
1270 Show auto-loading setting of all kinds of auto-loaded files.
1272 set auto-load gdb-scripts on|off
1273 show auto-load gdb-scripts
1274 Control auto-loading of GDB canned sequences of commands files.
1276 set auto-load python-scripts on|off
1277 show auto-load python-scripts
1278 Control auto-loading of Python script files.
1280 set auto-load local-gdbinit on|off
1281 show auto-load local-gdbinit
1282 Control loading of init file (.gdbinit) from current directory.
1284 set auto-load libthread-db on|off
1285 show auto-load libthread-db
1286 Control auto-loading of inferior specific thread debugging shared library.
1288 set auto-load scripts-directory <dir1>[:<dir2>...]
1289 show auto-load scripts-directory
1290 Set a list of directories from which to load auto-loaded scripts.
1291 Automatically loaded Python scripts and GDB scripts are located in one
1292 of the directories listed by this option.
1293 The delimiter (':' above) may differ according to the host platform.
1295 set auto-load safe-path <dir1>[:<dir2>...]
1296 show auto-load safe-path
1297 Set a list of directories from which it is safe to auto-load files.
1298 The delimiter (':' above) may differ according to the host platform.
1300 set debug auto-load on|off
1301 show debug auto-load
1302 Control display of debugging info for auto-loading the files above.
1304 set dprintf-style gdb|call|agent
1306 Control the way in which a dynamic printf is performed; "gdb"
1307 requests a GDB printf command, while "call" causes dprintf to call a
1308 function in the inferior. "agent" requests that the target agent
1309 (such as GDBserver) do the printing.
1311 set dprintf-function <expr>
1312 show dprintf-function
1313 set dprintf-channel <expr>
1314 show dprintf-channel
1315 Set the function and optional first argument to the call when using
1316 the "call" style of dynamic printf.
1318 set disconnected-dprintf on|off
1319 show disconnected-dprintf
1320 Control whether agent-style dynamic printfs continue to be in effect
1321 after GDB disconnects.
1323 * New configure options
1325 --with-auto-load-dir
1326 Configure default value for the 'set auto-load scripts-directory'
1327 setting above. It defaults to '$debugdir:$datadir/auto-load',
1328 $debugdir representing global debugging info directories (available
1329 via 'show debug-file-directory') and $datadir representing GDB's data
1330 directory (available via 'show data-directory').
1332 --with-auto-load-safe-path
1333 Configure default value for the 'set auto-load safe-path' setting
1334 above. It defaults to the --with-auto-load-dir setting.
1336 --without-auto-load-safe-path
1337 Set 'set auto-load safe-path' to '/', effectively disabling this
1340 * New remote packets
1342 z0/z1 conditional breakpoints extension
1344 The z0/z1 breakpoint insertion packets have been extended to carry
1345 a list of conditional expressions over to the remote stub depending on the
1346 condition evaluation mode. The use of this extension can be controlled
1347 via the "set remote conditional-breakpoints-packet" command.
1351 Specify the signals which the remote stub may pass to the debugged
1352 program without GDB involvement.
1354 * New command line options
1356 --init-command=FILE, -ix Like --command, -x but execute it
1357 before loading inferior.
1358 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1359 execute it before loading inferior.
1361 *** Changes in GDB 7.4
1363 * GDB now handles ambiguous linespecs more consistently; the existing
1364 FILE:LINE support has been expanded to other types of linespecs. A
1365 breakpoint will now be set on all matching locations in all
1366 inferiors, and locations will be added or removed according to
1369 * GDB now allows you to skip uninteresting functions and files when
1370 stepping with the "skip function" and "skip file" commands.
1372 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1373 and "show remote hardware-watchpoint-length-limit". These allows to
1374 set or show the maximum length limit (in bytes) of a remote
1375 target hardware watchpoint.
1377 This allows e.g. to use "unlimited" hardware watchpoints with the
1378 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1379 watchpoints are slower than real hardware watchpoints but are
1380 significantly faster than gdb software watchpoints.
1384 ** The register_pretty_printer function in module gdb.printing now takes
1385 an optional `replace' argument. If True, the new printer replaces any
1388 ** The "maint set python print-stack on|off" command has been
1389 deprecated and will be deleted in GDB 7.5.
1390 A new command: "set python print-stack none|full|message" has
1391 replaced it. Additionally, the default for "print-stack" is
1392 now "message", which just prints the error message without
1395 ** A prompt substitution hook (prompt_hook) is now available to the
1398 ** A new Python module, gdb.prompt has been added to the GDB Python
1399 modules library. This module provides functionality for
1400 escape sequences in prompts (used by set/show
1401 extended-prompt). These escape sequences are replaced by their
1402 corresponding value.
1404 ** Python commands and convenience-functions located in
1405 'data-directory'/python/gdb/command and
1406 'data-directory'/python/gdb/function are now automatically loaded
1409 ** Blocks now provide four new attributes. global_block and
1410 static_block will return the global and static blocks
1411 respectively. is_static and is_global are boolean attributes
1412 that indicate if the block is one of those two types.
1414 ** Symbols now provide the "type" attribute, the type of the symbol.
1416 ** The "gdb.breakpoint" function has been deprecated in favor of
1419 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1420 of a function. This class is based on the "finish" command
1421 available in the CLI.
1423 ** Type objects for struct and union types now allow access to
1424 the fields using standard Python dictionary (mapping) methods.
1425 For example, "some_type['myfield']" now works, as does
1426 "some_type.items()".
1428 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1431 ** A new function, "deep_items" has been added to the gdb.types
1432 module in the GDB Python modules library. This function returns
1433 an iterator over the fields of a struct or union type. Unlike
1434 the standard Python "iteritems" method, it will recursively traverse
1435 any anonymous fields.
1439 ** "*stopped" events can report several new "reason"s, such as
1442 ** Breakpoint changes are now notified using new async records, like
1443 "=breakpoint-modified".
1445 ** New command -ada-task-info.
1447 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1448 $sdir specifies the default system locations of shared libraries.
1449 $pdir specifies the directory where the libpthread used by the application
1452 GDB no longer looks in $sdir and $pdir after it has searched the directories
1453 mentioned in libthread-db-search-path. If you want to search those
1454 directories, they must be specified in libthread-db-search-path.
1455 The default value of libthread-db-search-path on GNU/Linux and Solaris
1456 systems is now "$sdir:$pdir".
1458 $pdir is not supported by gdbserver, it is currently ignored.
1459 $sdir is supported by gdbserver.
1461 * New configure option --with-iconv-bin.
1462 When using the internationalization support like the one in the GNU C
1463 library, GDB will invoke the "iconv" program to get a list of supported
1464 character sets. If this program lives in a non-standard location, one can
1465 use this option to specify where to find it.
1467 * When natively debugging programs on PowerPC BookE processors running
1468 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1469 watchpoints, which specify a mask in addition to an address to watch.
1470 The mask specifies that some bits of an address (the bits which are
1471 reset in the mask) should be ignored when matching the address accessed
1472 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1473 section in the user manual for more details.
1475 * The new option --once causes GDBserver to stop listening for connections once
1476 the first connection is made. The listening port used by GDBserver will
1477 become available after that.
1479 * New commands "info macros" and "alias" have been added.
1481 * New function parameters suffix @entry specifies value of function parameter
1482 at the time the function got called. Entry values are available only since
1488 "!" is now an alias of the "shell" command.
1489 Note that no space is needed between "!" and SHELL COMMAND.
1493 watch EXPRESSION mask MASK_VALUE
1494 The watch command now supports the mask argument which allows creation
1495 of masked watchpoints, if the current architecture supports this feature.
1497 info auto-load-scripts [REGEXP]
1498 This command was formerly named "maintenance print section-scripts".
1499 It is now generally useful and is no longer a maintenance-only command.
1501 info macro [-all] [--] MACRO
1502 The info macro command has new options `-all' and `--'. The first for
1503 printing all definitions of a macro. The second for explicitly specifying
1504 the end of arguments and the beginning of the macro name in case the macro
1505 name starts with a hyphen.
1507 collect[/s] EXPRESSIONS
1508 The tracepoint collect command now takes an optional modifier "/s"
1509 that directs it to dereference pointer-to-character types and
1510 collect the bytes of memory up to a zero byte. The behavior is
1511 similar to what you see when you use the regular print command on a
1512 string. An optional integer following the "/s" sets a bound on the
1513 number of bytes that will be collected.
1516 The trace start command now interprets any supplied arguments as a
1517 note to be recorded with the trace run, with an effect similar to
1518 setting the variable trace-notes.
1521 The trace stop command now interprets any arguments as a note to be
1522 mentioned along with the tstatus report that the trace was stopped
1523 with a command. The effect is similar to setting the variable
1526 * Tracepoints can now be enabled and disabled at any time after a trace
1527 experiment has been started using the standard "enable" and "disable"
1528 commands. It is now possible to start a trace experiment with no enabled
1529 tracepoints; GDB will display a warning, but will allow the experiment to
1530 begin, assuming that tracepoints will be enabled as needed while the trace
1533 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1534 locations with 4-byte instructions, when they were previously
1535 limited to locations with instructions of 5 bytes or longer.
1539 set debug dwarf2-read
1540 show debug dwarf2-read
1541 Turns on or off display of debugging messages related to reading
1542 DWARF debug info. The default is off.
1544 set debug symtab-create
1545 show debug symtab-create
1546 Turns on or off display of debugging messages related to symbol table
1547 creation. The default is off.
1550 show extended-prompt
1551 Set the GDB prompt, and allow escape sequences to be inserted to
1552 display miscellaneous information (see 'help set extended-prompt'
1553 for the list of sequences). This prompt (and any information
1554 accessed through the escape sequences) is updated every time the
1555 prompt is displayed.
1557 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1558 show print entry-values
1559 Set printing of frame argument values at function entry. In some cases
1560 GDB can determine the value of function argument which was passed by the
1561 function caller, even if the value was modified inside the called function.
1563 set debug entry-values
1564 show debug entry-values
1565 Control display of debugging info for determining frame argument values at
1566 function entry and virtual tail call frames.
1568 set basenames-may-differ
1569 show basenames-may-differ
1570 Set whether a source file may have multiple base names.
1571 (A "base name" is the name of a file with the directory part removed.
1572 Example: The base name of "/home/user/hello.c" is "hello.c".)
1573 If set, GDB will canonicalize file names (e.g., expand symlinks)
1574 before comparing them. Canonicalization is an expensive operation,
1575 but it allows the same file be known by more than one base name.
1576 If not set (the default), all source files are assumed to have just
1577 one base name, and gdb will do file name comparisons more efficiently.
1583 Set a user name and notes for the current and any future trace runs.
1584 This is useful for long-running and/or disconnected traces, to
1585 inform others (or yourself) as to who is running the trace, supply
1586 contact information, or otherwise explain what is going on.
1588 set trace-stop-notes
1589 show trace-stop-notes
1590 Set a note attached to the trace run, that is displayed when the
1591 trace has been stopped by a tstop command. This is useful for
1592 instance as an explanation, if you are stopping a trace run that was
1593 started by someone else.
1595 * New remote packets
1599 Dynamically enable a tracepoint in a started trace experiment.
1603 Dynamically disable a tracepoint in a started trace experiment.
1607 Set the user and notes of the trace run.
1611 Query the current status of a tracepoint.
1615 Query the minimum length of instruction at which a fast tracepoint may
1618 * Dcache size (number of lines) and line-size are now runtime-configurable
1619 via "set dcache line" and "set dcache line-size" commands.
1623 Texas Instruments TMS320C6x tic6x-*-*
1627 Renesas RL78 rl78-*-elf
1629 *** Changes in GDB 7.3.1
1631 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1633 *** Changes in GDB 7.3
1635 * GDB has a new command: "thread find [REGEXP]".
1636 It finds the thread id whose name, target id, or thread extra info
1637 matches the given regular expression.
1639 * The "catch syscall" command now works on mips*-linux* targets.
1641 * The -data-disassemble MI command now supports modes 2 and 3 for
1642 dumping the instruction opcodes.
1644 * New command line options
1646 -data-directory DIR Specify DIR as the "data-directory".
1647 This is mostly for testing purposes.
1649 * The "maint set python auto-load on|off" command has been renamed to
1650 "set auto-load-scripts on|off".
1652 * GDB has a new command: "set directories".
1653 It is like the "dir" command except that it replaces the
1654 source path list instead of augmenting it.
1656 * GDB now understands thread names.
1658 On GNU/Linux, "info threads" will display the thread name as set by
1659 prctl or pthread_setname_np.
1661 There is also a new command, "thread name", which can be used to
1662 assign a name internally for GDB to display.
1665 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1666 has been integrated into GDB.
1670 ** The function gdb.Write now accepts an optional keyword 'stream'.
1671 This keyword, when provided, will direct the output to either
1672 stdout, stderr, or GDB's logging output.
1674 ** Parameters can now be be sub-classed in Python, and in particular
1675 you may implement the get_set_doc and get_show_doc functions.
1676 This improves how Parameter set/show documentation is processed
1677 and allows for more dynamic content.
1679 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1680 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1681 have an is_valid method.
1683 ** Breakpoints can now be sub-classed in Python, and in particular
1684 you may implement a 'stop' function that is executed each time
1685 the inferior reaches that breakpoint.
1687 ** New function gdb.lookup_global_symbol looks up a global symbol.
1689 ** GDB values in Python are now callable if the value represents a
1690 function. For example, if 'some_value' represents a function that
1691 takes two integer parameters and returns a value, you can call
1692 that function like so:
1694 result = some_value (10,20)
1696 ** Module gdb.types has been added.
1697 It contains a collection of utilities for working with gdb.Types objects:
1698 get_basic_type, has_field, make_enum_dict.
1700 ** Module gdb.printing has been added.
1701 It contains utilities for writing and registering pretty-printers.
1702 New classes: PrettyPrinter, SubPrettyPrinter,
1703 RegexpCollectionPrettyPrinter.
1704 New function: register_pretty_printer.
1706 ** New commands "info pretty-printers", "enable pretty-printer" and
1707 "disable pretty-printer" have been added.
1709 ** gdb.parameter("directories") is now available.
1711 ** New function gdb.newest_frame returns the newest frame in the
1714 ** The gdb.InferiorThread class has a new "name" attribute. This
1715 holds the thread's name.
1717 ** Python Support for Inferior events.
1718 Python scripts can add observers to be notified of events
1719 occurring in the process being debugged.
1720 The following events are currently supported:
1721 - gdb.events.cont Continue event.
1722 - gdb.events.exited Inferior exited event.
1723 - gdb.events.stop Signal received, and Breakpoint hit events.
1727 ** GDB now puts template parameters in scope when debugging in an
1728 instantiation. For example, if you have:
1730 template<int X> int func (void) { return X; }
1732 then if you step into func<5>, "print X" will show "5". This
1733 feature requires proper debuginfo support from the compiler; it
1734 was added to GCC 4.5.
1736 ** The motion commands "next", "finish", "until", and "advance" now
1737 work better when exceptions are thrown. In particular, GDB will
1738 no longer lose control of the inferior; instead, the GDB will
1739 stop the inferior at the point at which the exception is caught.
1740 This functionality requires a change in the exception handling
1741 code that was introduced in GCC 4.5.
1743 * GDB now follows GCC's rules on accessing volatile objects when
1744 reading or writing target state during expression evaluation.
1745 One notable difference to prior behavior is that "print x = 0"
1746 no longer generates a read of x; the value of the assignment is
1747 now always taken directly from the value being assigned.
1749 * GDB now has some support for using labels in the program's source in
1750 linespecs. For instance, you can use "advance label" to continue
1751 execution to a label.
1753 * GDB now has support for reading and writing a new .gdb_index
1754 section. This section holds a fast index of DWARF debugging
1755 information and can be used to greatly speed up GDB startup and
1756 operation. See the documentation for `save gdb-index' for details.
1758 * The "watch" command now accepts an optional "-location" argument.
1759 When used, this causes GDB to watch the memory referred to by the
1760 expression. Such a watchpoint is never deleted due to it going out
1763 * GDB now supports thread debugging of core dumps on GNU/Linux.
1765 GDB now activates thread debugging using the libthread_db library
1766 when debugging GNU/Linux core dumps, similarly to when debugging
1767 live processes. As a result, when debugging a core dump file, GDB
1768 is now able to display pthread_t ids of threads. For example, "info
1769 threads" shows the same output as when debugging the process when it
1770 was live. In earlier releases, you'd see something like this:
1773 * 1 LWP 6780 main () at main.c:10
1775 While now you see this:
1778 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1780 It is also now possible to inspect TLS variables when debugging core
1783 When debugging a core dump generated on a machine other than the one
1784 used to run GDB, you may need to point GDB at the correct
1785 libthread_db library with the "set libthread-db-search-path"
1786 command. See the user manual for more details on this command.
1788 * When natively debugging programs on PowerPC BookE processors running
1789 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1790 which stop execution of the inferior whenever it executes an instruction
1791 at any address within the specified range. See the "PowerPC Embedded"
1792 section in the user manual for more details.
1794 * New features in the GDB remote stub, GDBserver
1796 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1797 and i686 LynxOS (version 5.x).
1799 ** GDBserver is now supported on Blackfin Linux.
1801 * New native configurations
1803 ia64 HP-UX ia64-*-hpux*
1807 Analog Devices, Inc. Blackfin Processor bfin-*
1809 * Ada task switching is now supported on sparc-elf targets when
1810 debugging a program using the Ravenscar Profile. For more information,
1811 see the "Tasking Support when using the Ravenscar Profile" section
1812 in the GDB user manual.
1814 * Guile support was removed.
1816 * New features in the GNU simulator
1818 ** The --map-info flag lists all known core mappings.
1820 ** CFI flashes may be simulated via the "cfi" device.
1822 *** Changes in GDB 7.2
1824 * Shared library support for remote targets by default
1826 When GDB is configured for a generic, non-OS specific target, like
1827 for example, --target=arm-eabi or one of the many *-*-elf targets,
1828 GDB now queries remote stubs for loaded shared libraries using the
1829 `qXfer:libraries:read' packet. Previously, shared library support
1830 was always disabled for such configurations.
1834 ** Argument Dependent Lookup (ADL)
1836 In C++ ADL lookup directs function search to the namespaces of its
1837 arguments even if the namespace has not been imported.
1847 Here the compiler will search for `foo' in the namespace of 'b'
1848 and find A::foo. GDB now supports this. This construct is commonly
1849 used in the Standard Template Library for operators.
1851 ** Improved User Defined Operator Support
1853 In addition to member operators, GDB now supports lookup of operators
1854 defined in a namespace and imported with a `using' directive, operators
1855 defined in the global scope, operators imported implicitly from an
1856 anonymous namespace, and the ADL operators mentioned in the previous
1858 GDB now also supports proper overload resolution for all the previously
1859 mentioned flavors of operators.
1861 ** static const class members
1863 Printing of static const class members that are initialized in the
1864 class definition has been fixed.
1866 * Windows Thread Information Block access.
1868 On Windows targets, GDB now supports displaying the Windows Thread
1869 Information Block (TIB) structure. This structure is visible either
1870 by using the new command `info w32 thread-information-block' or, by
1871 dereferencing the new convenience variable named `$_tlb', a
1872 thread-specific pointer to the TIB. This feature is also supported
1873 when remote debugging using GDBserver.
1875 * Static tracepoints
1877 Static tracepoints are calls in the user program into a tracing
1878 library. One such library is a port of the LTTng kernel tracer to
1879 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1880 When debugging with GDBserver, GDB now supports combining the GDB
1881 tracepoint machinery with such libraries. For example: the user can
1882 use GDB to probe a static tracepoint marker (a call from the user
1883 program into the tracing library) with the new "strace" command (see
1884 "New commands" below). This creates a "static tracepoint" in the
1885 breakpoint list, that can be manipulated with the same feature set
1886 as fast and regular tracepoints. E.g., collect registers, local and
1887 global variables, collect trace state variables, and define
1888 tracepoint conditions. In addition, the user can collect extra
1889 static tracepoint marker specific data, by collecting the new
1890 $_sdata internal variable. When analyzing the trace buffer, you can
1891 inspect $_sdata like any other variable available to GDB. For more
1892 information, see the "Tracepoints" chapter in GDB user manual. New
1893 remote packets have been defined to support static tracepoints, see
1894 the "New remote packets" section below.
1896 * Better reconstruction of tracepoints after disconnected tracing
1898 GDB will attempt to download the original source form of tracepoint
1899 definitions when starting a trace run, and then will upload these
1900 upon reconnection to the target, resulting in a more accurate
1901 reconstruction of the tracepoints that are in use on the target.
1905 You can now exercise direct control over the ways that GDB can
1906 affect your program. For instance, you can disallow the setting of
1907 breakpoints, so that the program can run continuously (assuming
1908 non-stop mode). In addition, the "observer" variable is available
1909 to switch all of the different controls; in observer mode, GDB
1910 cannot affect the target's behavior at all, which is useful for
1911 tasks like diagnosing live systems in the field.
1913 * The new convenience variable $_thread holds the number of the
1916 * New remote packets
1920 Return the address of the Windows Thread Information Block of a given thread.
1924 In response to several of the tracepoint packets, the target may now
1925 also respond with a number of intermediate `qRelocInsn' request
1926 packets before the final result packet, to have GDB handle
1927 relocating an instruction to execute at a different address. This
1928 is particularly useful for stubs that support fast tracepoints. GDB
1929 reports support for this feature in the qSupported packet.
1933 List static tracepoint markers in the target program.
1937 List static tracepoint markers at a given address in the target
1940 qXfer:statictrace:read
1942 Read the static trace data collected (by a `collect $_sdata'
1943 tracepoint action). The remote stub reports support for this packet
1944 to gdb's qSupported query.
1948 Send the current settings of GDB's permission flags.
1952 Send part of the source (textual) form of a tracepoint definition,
1953 which includes location, conditional, and action list.
1955 * The source command now accepts a -s option to force searching for the
1956 script in the source search path even if the script name specifies
1959 * New features in the GDB remote stub, GDBserver
1961 - GDBserver now support tracepoints (including fast tracepoints, and
1962 static tracepoints). The feature is currently supported by the
1963 i386-linux and amd64-linux builds. See the "Tracepoints support
1964 in gdbserver" section in the manual for more information.
1966 GDBserver JIT compiles the tracepoint's conditional agent
1967 expression bytecode into native code whenever possible for low
1968 overhead dynamic tracepoints conditionals. For such tracepoints,
1969 an expression that examines program state is evaluated when the
1970 tracepoint is reached, in order to determine whether to capture
1971 trace data. If the condition is simple and false, processing the
1972 tracepoint finishes very quickly and no data is gathered.
1974 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1975 for static tracepoints support.
1977 - GDBserver now supports x86_64 Windows 64-bit debugging.
1979 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1980 it understands register description.
1982 * The --batch flag now disables pagination and queries.
1984 * X86 general purpose registers
1986 GDB now supports reading/writing byte, word and double-word x86
1987 general purpose registers directly. This means you can use, say,
1988 $ah or $ax to refer, respectively, to the byte register AH and
1989 16-bit word register AX that are actually portions of the 32-bit
1990 register EAX or 64-bit register RAX.
1992 * The `commands' command now accepts a range of breakpoints to modify.
1993 A plain `commands' following a command that creates multiple
1994 breakpoints affects all the breakpoints set by that command. This
1995 applies to breakpoints set by `rbreak', and also applies when a
1996 single `break' command creates multiple breakpoints (e.g.,
1997 breakpoints on overloaded c++ functions).
1999 * The `rbreak' command now accepts a filename specification as part of
2000 its argument, limiting the functions selected by the regex to those
2001 in the specified file.
2003 * Support for remote debugging Windows and SymbianOS shared libraries
2004 from Unix hosts has been improved. Non Windows GDB builds now can
2005 understand target reported file names that follow MS-DOS based file
2006 system semantics, such as file names that include drive letters and
2007 use the backslash character as directory separator. This makes it
2008 possible to transparently use the "set sysroot" and "set
2009 solib-search-path" on Unix hosts to point as host copies of the
2010 target's shared libraries. See the new command "set
2011 target-file-system-kind" described below, and the "Commands to
2012 specify files" section in the user manual for more information.
2016 eval template, expressions...
2017 Convert the values of one or more expressions under the control
2018 of the string template to a command line, and call it.
2020 set target-file-system-kind unix|dos-based|auto
2021 show target-file-system-kind
2022 Set or show the assumed file system kind for target reported file
2025 save breakpoints <filename>
2026 Save all current breakpoint definitions to a file suitable for use
2027 in a later debugging session. To read the saved breakpoint
2028 definitions, use the `source' command.
2030 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2033 info static-tracepoint-markers
2034 Display information about static tracepoint markers in the target.
2036 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2037 Define a static tracepoint by probing a marker at the given
2038 function, line, address, or marker ID.
2042 Enable and disable observer mode.
2044 set may-write-registers on|off
2045 set may-write-memory on|off
2046 set may-insert-breakpoints on|off
2047 set may-insert-tracepoints on|off
2048 set may-insert-fast-tracepoints on|off
2049 set may-interrupt on|off
2050 Set individual permissions for GDB effects on the target. Note that
2051 some of these settings can have undesirable or surprising
2052 consequences, particularly when changed in the middle of a session.
2053 For instance, disabling the writing of memory can prevent
2054 breakpoints from being inserted, cause single-stepping to fail, or
2055 even crash your program, if you disable after breakpoints have been
2056 inserted. However, GDB should not crash.
2058 set record memory-query on|off
2059 show record memory-query
2060 Control whether to stop the inferior if memory changes caused
2061 by an instruction cannot be recorded.
2066 The disassemble command now supports "start,+length" form of two arguments.
2070 ** GDB now provides a new directory location, called the python directory,
2071 where Python scripts written for GDB can be installed. The location
2072 of that directory is <data-directory>/python, where <data-directory>
2073 is the GDB data directory. For more details, see section `Scripting
2074 GDB using Python' in the manual.
2076 ** The GDB Python API now has access to breakpoints, symbols, symbol
2077 tables, program spaces, inferiors, threads and frame's code blocks.
2078 Additionally, GDB Parameters can now be created from the API, and
2079 manipulated via set/show in the CLI.
2081 ** New functions gdb.target_charset, gdb.target_wide_charset,
2082 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2084 ** New exception gdb.GdbError.
2086 ** Pretty-printers are now also looked up in the current program space.
2088 ** Pretty-printers can now be individually enabled and disabled.
2090 ** GDB now looks for names of Python scripts to auto-load in a
2091 special section named `.debug_gdb_scripts', in addition to looking
2092 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2094 * Tracepoint actions were unified with breakpoint commands. In particular,
2095 there are no longer differences in "info break" output for breakpoints and
2096 tracepoints and the "commands" command can be used for both tracepoints and
2097 regular breakpoints.
2101 ARM Symbian arm*-*-symbianelf*
2103 * D language support.
2104 GDB now supports debugging programs written in the D programming
2107 * GDB now supports the extended ptrace interface for PowerPC which is
2108 available since Linux kernel version 2.6.34. This automatically enables
2109 any hardware breakpoints and additional hardware watchpoints available in
2110 the processor. The old ptrace interface exposes just one hardware
2111 watchpoint and no hardware breakpoints.
2113 * GDB is now able to use the Data Value Compare (DVC) register available on
2114 embedded PowerPC processors to implement in hardware simple watchpoint
2115 conditions of the form:
2117 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2119 This works in native GDB running on Linux kernels with the extended ptrace
2120 interface mentioned above.
2122 *** Changes in GDB 7.1
2126 ** Namespace Support
2128 GDB now supports importing of namespaces in C++. This enables the
2129 user to inspect variables from imported namespaces. Support for
2130 namepace aliasing has also been added. So, if a namespace is
2131 aliased in the current scope (e.g. namepace C=A; ) the user can
2132 print variables using the alias (e.g. (gdb) print C::x).
2136 All known bugs relating to the printing of virtual base class were
2137 fixed. It is now possible to call overloaded static methods using a
2142 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2143 and reinterpret_cast<> are now handled by the C++ expression parser.
2147 Xilinx MicroBlaze microblaze-*-*
2152 Xilinx MicroBlaze microblaze
2155 * Multi-program debugging.
2157 GDB now has support for multi-program (a.k.a. multi-executable or
2158 multi-exec) debugging. This allows for debugging multiple inferiors
2159 simultaneously each running a different program under the same GDB
2160 session. See "Debugging Multiple Inferiors and Programs" in the
2161 manual for more information. This implied some user visible changes
2162 in the multi-inferior support. For example, "info inferiors" now
2163 lists inferiors that are not running yet or that have exited
2164 already. See also "New commands" and "New options" below.
2166 * New tracing features
2168 GDB's tracepoint facility now includes several new features:
2170 ** Trace state variables
2172 GDB tracepoints now include support for trace state variables, which
2173 are variables managed by the target agent during a tracing
2174 experiment. They are useful for tracepoints that trigger each
2175 other, so for instance one tracepoint can count hits in a variable,
2176 and then a second tracepoint has a condition that is true when the
2177 count reaches a particular value. Trace state variables share the
2178 $-syntax of GDB convenience variables, and can appear in both
2179 tracepoint actions and condition expressions. Use the "tvariable"
2180 command to create, and "info tvariables" to view; see "Trace State
2181 Variables" in the manual for more detail.
2185 GDB now includes an option for defining fast tracepoints, which
2186 targets may implement more efficiently, such as by installing a jump
2187 into the target agent rather than a trap instruction. The resulting
2188 speedup can be by two orders of magnitude or more, although the
2189 tradeoff is that some program locations on some target architectures
2190 might not allow fast tracepoint installation, for instance if the
2191 instruction to be replaced is shorter than the jump. To request a
2192 fast tracepoint, use the "ftrace" command, with syntax identical to
2193 the regular trace command.
2195 ** Disconnected tracing
2197 It is now possible to detach GDB from the target while it is running
2198 a trace experiment, then reconnect later to see how the experiment
2199 is going. In addition, a new variable disconnected-tracing lets you
2200 tell the target agent whether to continue running a trace if the
2201 connection is lost unexpectedly.
2205 GDB now has the ability to save the trace buffer into a file, and
2206 then use that file as a target, similarly to you can do with
2207 corefiles. You can select trace frames, print data that was
2208 collected in them, and use tstatus to display the state of the
2209 tracing run at the moment that it was saved. To create a trace
2210 file, use "tsave <filename>", and to use it, do "target tfile
2213 ** Circular trace buffer
2215 You can ask the target agent to handle the trace buffer as a
2216 circular buffer, discarding the oldest trace frames to make room for
2217 newer ones, by setting circular-trace-buffer to on. This feature may
2218 not be available for all target agents.
2223 The disassemble command, when invoked with two arguments, now requires
2224 the arguments to be comma-separated.
2227 The info variables command now displays variable definitions. Files
2228 which only declare a variable are not shown.
2231 The source command is now capable of sourcing Python scripts.
2232 This feature is dependent on the debugger being build with Python
2235 Related to this enhancement is also the introduction of a new command
2236 "set script-extension" (see below).
2238 * New commands (for set/show, see "New options" below)
2240 record save [<FILENAME>]
2241 Save a file (in core file format) containing the process record
2242 execution log for replay debugging at a later time.
2244 record restore <FILENAME>
2245 Restore the process record execution log that was saved at an
2246 earlier time, for replay debugging.
2248 add-inferior [-copies <N>] [-exec <FILENAME>]
2251 clone-inferior [-copies <N>] [ID]
2252 Make a new inferior ready to execute the same program another
2253 inferior has loaded.
2258 maint info program-spaces
2259 List the program spaces loaded into GDB.
2261 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2262 show remote interrupt-sequence
2263 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2264 as the sequence to the remote target in order to interrupt the execution.
2265 Ctrl-C is a default. Some system prefers BREAK which is high level of
2266 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2267 Magic SysRq g. It is BREAK signal and character 'g'.
2269 set remote interrupt-on-connect [on | off]
2270 show remote interrupt-on-connect
2271 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2272 remote target when gdb connects to it. This is needed when you debug
2275 set remotebreak [on | off]
2277 Deprecated. Use "set/show remote interrupt-sequence" instead.
2279 tvariable $NAME [ = EXP ]
2280 Create or modify a trace state variable.
2283 List trace state variables and their values.
2285 delete tvariable $NAME ...
2286 Delete one or more trace state variables.
2289 Evaluate the given expressions without collecting anything into the
2290 trace buffer. (Valid in tracepoint actions only.)
2292 ftrace FN / FILE:LINE / *ADDR
2293 Define a fast tracepoint at the given function, line, or address.
2295 * New expression syntax
2297 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2298 GDB now parses 0b101010 identically with 42.
2302 set follow-exec-mode new|same
2303 show follow-exec-mode
2304 Control whether GDB reuses the same inferior across an exec call or
2305 creates a new one. This is useful to be able to restart the old
2306 executable after the inferior having done an exec call.
2308 set default-collect EXPR, ...
2309 show default-collect
2310 Define a list of expressions to be collected at each tracepoint.
2311 This is a useful way to ensure essential items are not overlooked,
2312 such as registers or a critical global variable.
2314 set disconnected-tracing
2315 show disconnected-tracing
2316 If set to 1, the target is instructed to continue tracing if it
2317 loses its connection to GDB. If 0, the target is to stop tracing
2320 set circular-trace-buffer
2321 show circular-trace-buffer
2322 If set to on, the target is instructed to use a circular trace buffer
2323 and discard the oldest trace frames instead of stopping the trace due
2324 to a full trace buffer. If set to off, the trace stops when the buffer
2325 fills up. Some targets may not support this.
2327 set script-extension off|soft|strict
2328 show script-extension
2329 If set to "off", the debugger does not perform any script language
2330 recognition, and all sourced files are assumed to be GDB scripts.
2331 If set to "soft" (the default), files are sourced according to
2332 filename extension, falling back to GDB scripts if the first
2334 If set to "strict", files are sourced according to filename extension.
2336 set ada trust-PAD-over-XVS on|off
2337 show ada trust-PAD-over-XVS
2338 If off, activate a workaround against a bug in the debugging information
2339 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2340 the GCC sources for more information about the GNAT encoding and
2341 PAD types in particular). It is always safe to set this option to
2342 off, but this introduces a slight performance penalty. The default
2345 * Python API Improvements
2347 ** GDB provides the new class gdb.LazyString. This is useful in
2348 some pretty-printing cases. The new method gdb.Value.lazy_string
2349 provides a simple way to create objects of this type.
2351 ** The fields returned by gdb.Type.fields now have an
2352 `is_base_class' attribute.
2354 ** The new method gdb.Type.range returns the range of an array type.
2356 ** The new method gdb.parse_and_eval can be used to parse and
2357 evaluate an expression.
2359 * New remote packets
2362 Define a trace state variable.
2365 Get the current value of a trace state variable.
2368 Set desired tracing behavior upon disconnection.
2371 Set the trace buffer to be linear or circular.
2374 Get data about the tracepoints currently in use.
2378 Process record now works correctly with hardware watchpoints.
2380 Multiple bug fixes have been made to the mips-irix port, making it
2381 much more reliable. In particular:
2382 - Debugging threaded applications is now possible again. Previously,
2383 GDB would hang while starting the program, or while waiting for
2384 the program to stop at a breakpoint.
2385 - Attaching to a running process no longer hangs.
2386 - An error occurring while loading a core file has been fixed.
2387 - Changing the value of the PC register now works again. This fixes
2388 problems observed when using the "jump" command, or when calling
2389 a function from GDB, or even when assigning a new value to $pc.
2390 - With the "finish" and "return" commands, the return value for functions
2391 returning a small array is now correctly printed.
2392 - It is now possible to break on shared library code which gets executed
2393 during a shared library init phase (code executed while executing
2394 their .init section). Previously, the breakpoint would have no effect.
2395 - GDB is now able to backtrace through the signal handler for
2396 non-threaded programs.
2398 PIE (Position Independent Executable) programs debugging is now supported.
2399 This includes debugging execution of PIC (Position Independent Code) shared
2400 libraries although for that, it should be possible to run such libraries as an
2403 *** Changes in GDB 7.0
2405 * GDB now has an interface for JIT compilation. Applications that
2406 dynamically generate code can create symbol files in memory and register
2407 them with GDB. For users, the feature should work transparently, and
2408 for JIT developers, the interface is documented in the GDB manual in the
2409 "JIT Compilation Interface" chapter.
2411 * Tracepoints may now be conditional. The syntax is as for
2412 breakpoints; either an "if" clause appended to the "trace" command,
2413 or the "condition" command is available. GDB sends the condition to
2414 the target for evaluation using the same bytecode format as is used
2415 for tracepoint actions.
2417 * The disassemble command now supports: an optional /r modifier, print the
2418 raw instructions in hex as well as in symbolic form, and an optional /m
2419 modifier to print mixed source+assembly.
2421 * Process record and replay
2423 In a architecture environment that supports ``process record and
2424 replay'', ``process record and replay'' target can record a log of
2425 the process execution, and replay it with both forward and reverse
2428 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2429 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2430 set execution-direction {forward|reverse}, for targets that support
2433 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2434 feature is available with a native GDB running on kernel version
2437 * GDB now has support for multi-byte and wide character sets on the
2438 target. Strings whose character type is wchar_t, char16_t, or
2439 char32_t are now correctly printed. GDB supports wide- and unicode-
2440 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2441 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2442 `printf'. This feature requires iconv to work properly; if your
2443 system does not have a working iconv, GDB can use GNU libiconv. See
2444 the installation instructions for more information.
2446 * GDB now supports automatic retrieval of shared library files from
2447 remote targets. To use this feature, specify a system root that begins
2448 with the `remote:' prefix, either via the `set sysroot' command or via
2449 the `--with-sysroot' configure-time option.
2451 * "info sharedlibrary" now takes an optional regex of libraries to show,
2452 and it now reports if a shared library has no debugging information.
2454 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2455 now complete on file names.
2457 * When completing in expressions, gdb will attempt to limit
2458 completions to allowable structure or union fields, where appropriate.
2459 For instance, consider:
2461 # struct example { int f1; double f2; };
2462 # struct example variable;
2465 If the user types TAB at the end of this command line, the available
2466 completions will be "f1" and "f2".
2468 * Inlined functions are now supported. They show up in backtraces, and
2469 the "step", "next", and "finish" commands handle them automatically.
2471 * GDB now supports the token-splicing (##) and stringification (#)
2472 operators when expanding macros. It also supports variable-arity
2475 * GDB now supports inspecting extra signal information, exported by
2476 the new $_siginfo convenience variable. The feature is currently
2477 implemented on linux ARM, i386 and amd64.
2479 * GDB can now display the VFP floating point registers and NEON vector
2480 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2481 can provide these registers (requires Linux 2.6.30 or later). Remote
2482 and simulator targets may also provide them.
2484 * New remote packets
2487 Search memory for a sequence of bytes.
2490 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2491 operation over reliable transport links. Use of this packet is
2492 controlled by the `set remote noack-packet' command.
2495 Kill the process with the specified process ID. Use this in preference
2496 to `k' when multiprocess protocol extensions are supported.
2499 Obtains additional operating system information
2503 Read or write additional signal information.
2505 * Removed remote protocol undocumented extension
2507 An undocumented extension to the remote protocol's `S' stop reply
2508 packet that permited the stub to pass a process id was removed.
2509 Remote servers should use the `T' stop reply packet instead.
2511 * GDB now supports multiple function calling conventions according to the
2512 DWARF-2 DW_AT_calling_convention function attribute.
2514 * The SH target utilizes the aforementioned change to distinguish between gcc
2515 and Renesas calling convention. It also adds the new CLI commands
2516 `set/show sh calling-convention'.
2518 * GDB can now read compressed debug sections, as produced by GNU gold
2519 with the --compress-debug-sections=zlib flag.
2521 * 64-bit core files are now supported on AIX.
2523 * Thread switching is now supported on Tru64.
2525 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2526 which will be allocated using malloc later in program execution.
2528 * The qXfer:libraries:read remote procotol packet now allows passing a
2529 list of section offsets.
2531 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2532 conditions handling signals delivered during attach or thread creation
2533 have also been fixed.
2535 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2536 From the user's standpoint, all unqualified instances of True and False
2537 are treated as the standard definitions, regardless of context.
2539 * GDB now parses C++ symbol and type names more flexibly. For
2542 template<typename T> class C { };
2545 GDB will now correctly handle all of:
2547 ptype C<char const *>
2548 ptype C<char const*>
2549 ptype C<const char *>
2550 ptype C<const char*>
2552 * New features in the GDB remote stub, gdbserver
2554 - The "--wrapper" command-line argument tells gdbserver to use a
2555 wrapper program to launch programs for debugging.
2557 - On PowerPC and S/390 targets, it is now possible to use a single
2558 gdbserver executable to debug both 32-bit and 64-bit programs.
2559 (This requires gdbserver itself to be built as a 64-bit executable.)
2561 - gdbserver uses the new noack protocol mode for TCP connections to
2562 reduce communications latency, if also supported and enabled in GDB.
2564 - Support for the sparc64-linux-gnu target is now included in
2567 - The amd64-linux build of gdbserver now supports debugging both
2568 32-bit and 64-bit programs.
2570 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2571 now support hardware watchpoints, and will use them automatically
2576 GDB now has support for scripting using Python. Whether this is
2577 available is determined at configure time.
2579 New GDB commands can now be written in Python.
2581 * Ada tasking support
2583 Ada tasks can now be inspected in GDB. The following commands have
2587 Print the list of Ada tasks.
2589 Print detailed information about task number N.
2591 Print the task number of the current task.
2593 Switch the context of debugging to task number N.
2595 * Support for user-defined prefixed commands. The "define" command can
2596 add new commands to existing prefixes, e.g. "target".
2598 * Multi-inferior, multi-process debugging.
2600 GDB now has generalized support for multi-inferior debugging. See
2601 "Debugging Multiple Inferiors" in the manual for more information.
2602 Although availability still depends on target support, the command
2603 set is more uniform now. The GNU/Linux specific multi-forks support
2604 has been migrated to this new framework. This implied some user
2605 visible changes; see "New commands" and also "Removed commands"
2608 * Target descriptions can now describe the target OS ABI. See the
2609 "Target Description Format" section in the user manual for more
2612 * Target descriptions can now describe "compatible" architectures
2613 to indicate that the target can execute applications for a different
2614 architecture in addition to those for the main target architecture.
2615 See the "Target Description Format" section in the user manual for
2618 * Multi-architecture debugging.
2620 GDB now includes general supports for debugging applications on
2621 hybrid systems that use more than one single processor architecture
2622 at the same time. Each such hybrid architecture still requires
2623 specific support to be added. The only hybrid architecture supported
2624 in this version of GDB is the Cell Broadband Engine.
2626 * GDB now supports integrated debugging of Cell/B.E. applications that
2627 use both the PPU and SPU architectures. To enable support for hybrid
2628 Cell/B.E. debugging, you need to configure GDB to support both the
2629 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2630 --enable-targets configure option.
2632 * Non-stop mode debugging.
2634 For some targets, GDB now supports an optional mode of operation in
2635 which you can examine stopped threads while other threads continue
2636 to execute freely. This is referred to as non-stop mode, with the
2637 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2638 section in the user manual for more information.
2640 To be able to support remote non-stop debugging, a remote stub needs
2641 to implement the non-stop mode remote protocol extensions, as
2642 described in the "Remote Non-Stop" section of the user manual. The
2643 GDB remote stub, gdbserver, has been adjusted to support these
2644 extensions on linux targets.
2646 * New commands (for set/show, see "New options" below)
2648 catch syscall [NAME(S) | NUMBER(S)]
2649 Catch system calls. Arguments, which should be names of system
2650 calls or their numbers, mean catch only those syscalls. Without
2651 arguments, every syscall will be caught. When the inferior issues
2652 any of the specified syscalls, GDB will stop and announce the system
2653 call, both when it is called and when its call returns. This
2654 feature is currently available with a native GDB running on the
2655 Linux Kernel, under the following architectures: x86, x86_64,
2656 PowerPC and PowerPC64.
2658 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2660 Search memory for a sequence of bytes.
2662 maint set python print-stack
2663 maint show python print-stack
2664 Show a stack trace when an error is encountered in a Python script.
2667 Invoke CODE by passing it to the Python interpreter.
2672 These allow macros to be defined, undefined, and listed
2676 Show operating system information about processes.
2679 List the inferiors currently under GDB's control.
2682 Switch focus to inferior number NUM.
2685 Detach from inferior number NUM.
2688 Kill inferior number NUM.
2692 set spu stop-on-load
2693 show spu stop-on-load
2694 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2696 set spu auto-flush-cache
2697 show spu auto-flush-cache
2698 Control whether to automatically flush the software-managed cache
2699 during Cell/B.E. debugging.
2701 set sh calling-convention
2702 show sh calling-convention
2703 Control the calling convention used when calling SH target functions.
2706 show debug timestamp
2707 Control display of timestamps with GDB debugging output.
2709 set disassemble-next-line
2710 show disassemble-next-line
2711 Control display of disassembled source lines or instructions when
2714 set remote noack-packet
2715 show remote noack-packet
2716 Set/show the use of remote protocol QStartNoAckMode packet. See above
2717 under "New remote packets."
2719 set remote query-attached-packet
2720 show remote query-attached-packet
2721 Control use of remote protocol `qAttached' (query-attached) packet.
2723 set remote read-siginfo-object
2724 show remote read-siginfo-object
2725 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2728 set remote write-siginfo-object
2729 show remote write-siginfo-object
2730 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2733 set remote reverse-continue
2734 show remote reverse-continue
2735 Control use of remote protocol 'bc' (reverse-continue) packet.
2737 set remote reverse-step
2738 show remote reverse-step
2739 Control use of remote protocol 'bs' (reverse-step) packet.
2741 set displaced-stepping
2742 show displaced-stepping
2743 Control displaced stepping mode. Displaced stepping is a way to
2744 single-step over breakpoints without removing them from the debuggee.
2745 Also known as "out-of-line single-stepping".
2748 show debug displaced
2749 Control display of debugging info for displaced stepping.
2751 maint set internal-error
2752 maint show internal-error
2753 Control what GDB does when an internal error is detected.
2755 maint set internal-warning
2756 maint show internal-warning
2757 Control what GDB does when an internal warning is detected.
2762 Use a wrapper program to launch programs for debugging.
2764 set multiple-symbols (all|ask|cancel)
2765 show multiple-symbols
2766 The value of this variable can be changed to adjust the debugger behavior
2767 when an expression or a breakpoint location contains an ambiguous symbol
2768 name (an overloaded function name, for instance).
2770 set breakpoint always-inserted
2771 show breakpoint always-inserted
2772 Keep breakpoints always inserted in the target, as opposed to inserting
2773 them when resuming the target, and removing them when the target stops.
2774 This option can improve debugger performance on slow remote targets.
2776 set arm fallback-mode (arm|thumb|auto)
2777 show arm fallback-mode
2778 set arm force-mode (arm|thumb|auto)
2780 These commands control how ARM GDB determines whether instructions
2781 are ARM or Thumb. The default for both settings is auto, which uses
2782 the current CPSR value for instructions without symbols; previous
2783 versions of GDB behaved as if "set arm fallback-mode arm".
2785 set disable-randomization
2786 show disable-randomization
2787 Standalone programs run with the virtual address space randomization enabled
2788 by default on some platforms. This option keeps the addresses stable across
2789 multiple debugging sessions.
2793 Control whether other threads are stopped or not when some thread hits
2798 Requests that asynchronous execution is enabled in the target, if available.
2799 In this case, it's possible to resume target in the background, and interact
2800 with GDB while the target is running. "show target-async" displays the
2801 current state of asynchronous execution of the target.
2803 set target-wide-charset
2804 show target-wide-charset
2805 The target-wide-charset is the name of the character set that GDB
2806 uses when printing characters whose type is wchar_t.
2808 set tcp auto-retry (on|off)
2810 set tcp connect-timeout
2811 show tcp connect-timeout
2812 These commands allow GDB to retry failed TCP connections to a remote stub
2813 with a specified timeout period; this is useful if the stub is launched
2814 in parallel with GDB but may not be ready to accept connections immediately.
2816 set libthread-db-search-path
2817 show libthread-db-search-path
2818 Control list of directories which GDB will search for appropriate
2821 set schedule-multiple (on|off)
2822 show schedule-multiple
2823 Allow GDB to resume all threads of all processes or only threads of
2824 the current process.
2828 Use more aggressive caching for accesses to the stack. This improves
2829 performance of remote debugging (particularly backtraces) without
2830 affecting correctness.
2832 set interactive-mode (on|off|auto)
2833 show interactive-mode
2834 Control whether GDB runs in interactive mode (on) or not (off).
2835 When in interactive mode, GDB waits for the user to answer all
2836 queries. Otherwise, GDB does not wait and assumes the default
2837 answer. When set to auto (the default), GDB determines which
2838 mode to use based on the stdin settings.
2843 For program forks, this is replaced by the new more generic `info
2844 inferiors' command. To list checkpoints, you can still use the
2845 `info checkpoints' command, which was an alias for the `info forks'
2849 Replaced by the new `inferior' command. To switch between
2850 checkpoints, you can still use the `restart' command, which was an
2851 alias for the `fork' command.
2854 This is removed, since some targets don't have a notion of
2855 processes. To switch between processes, you can still use the
2856 `inferior' command using GDB's own inferior number.
2859 For program forks, this is replaced by the new more generic `kill
2860 inferior' command. To delete a checkpoint, you can still use the
2861 `delete checkpoint' command, which was an alias for the `delete
2865 For program forks, this is replaced by the new more generic `detach
2866 inferior' command. To detach a checkpoint, you can still use the
2867 `detach checkpoint' command, which was an alias for the `detach
2870 * New native configurations
2872 x86/x86_64 Darwin i[34567]86-*-darwin*
2874 x86_64 MinGW x86_64-*-mingw*
2878 Lattice Mico32 lm32-*
2879 x86 DICOS i[34567]86-*-dicos*
2880 x86_64 DICOS x86_64-*-dicos*
2883 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2884 (mingw32ce) debugging.
2890 These commands were actually not implemented on any target.
2892 *** Changes in GDB 6.8
2894 * New native configurations
2896 NetBSD/hppa hppa*-*netbsd*
2897 Xtensa GNU/Linux xtensa*-*-linux*
2901 NetBSD/hppa hppa*-*-netbsd*
2902 Xtensa GNU/Lunux xtensa*-*-linux*
2904 * Change in command line behavior -- corefiles vs. process ids.
2906 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2907 attaching to process NUMBER fails, GDB no longer attempts to open a
2908 core file named NUMBER. Attaching to a program using the -c option
2909 is no longer supported. Instead, use the '-p' or '--pid' options.
2911 * GDB can now be built as a native debugger for debugging Windows x86
2912 (mingw32) Portable Executable (PE) programs.
2914 * Pending breakpoints no longer change their number when their address
2917 * GDB now supports breakpoints with multiple locations,
2918 including breakpoints on C++ constructors, inside C++ templates,
2919 and in inlined functions.
2921 * GDB's ability to debug optimized code has been improved. GDB more
2922 accurately identifies function bodies and lexical blocks that occupy
2923 more than one contiguous range of addresses.
2925 * Target descriptions can now describe registers for PowerPC.
2927 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2928 registers on PowerPC targets.
2930 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2931 targets even when the libthread_db library is not available.
2933 * The GDB remote stub, gdbserver, now supports the new file transfer
2934 commands (remote put, remote get, and remote delete).
2936 * The GDB remote stub, gdbserver, now supports run and attach in
2937 extended-remote mode.
2939 * hppa*64*-*-hpux11* target broken
2940 The debugger is unable to start a program and fails with the following
2941 error: "Error trying to get information about dynamic linker".
2942 The gdb-6.7 release is also affected.
2944 * GDB now supports the --enable-targets= configure option to allow
2945 building a single GDB executable that supports multiple remote
2946 target architectures.
2948 * GDB now supports debugging C and C++ programs which use the
2949 Decimal Floating Point extension. In addition, the PowerPC target
2950 now has a set of pseudo-registers to inspect decimal float values
2951 stored in two consecutive float registers.
2953 * The -break-insert MI command can optionally create pending
2956 * Improved support for debugging Ada
2957 Many improvements to the Ada language support have been made. These
2959 - Better support for Ada2005 interface types
2960 - Improved handling of arrays and slices in general
2961 - Better support for Taft-amendment types
2962 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2964 - Improved command completion in Ada
2967 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2972 set print frame-arguments (all|scalars|none)
2973 show print frame-arguments
2974 The value of this variable can be changed to control which argument
2975 values should be printed by the debugger when displaying a frame.
2980 Transfer files to and from a remote target, and delete remote files.
2987 Transfer files to and from a remote target, and delete remote files.
2989 * New remote packets
2996 Open, close, read, write, and delete files on the remote system.
2999 Attach to an existing process on the remote system, in extended-remote
3003 Run a new process on the remote system, in extended-remote mode.
3005 *** Changes in GDB 6.7
3007 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3008 bfd, libiberty and opcodes, as revealed by static analysis donated by
3009 Coverity, Inc. (http://scan.coverity.com).
3011 * When looking up multiply-defined global symbols, GDB will now prefer the
3012 symbol definition in the current shared library if it was built using the
3013 -Bsymbolic linker option.
3015 * When the Text User Interface (TUI) is not configured, GDB will now
3016 recognize the -tui command-line option and print a message that the TUI
3019 * The GDB remote stub, gdbserver, now has lower overhead for high
3020 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3022 * GDB for MIPS targets now autodetects whether a remote target provides
3023 32-bit or 64-bit register values.
3025 * Support for C++ member pointers has been improved.
3027 * GDB now understands XML target descriptions, which specify the
3028 target's overall architecture. GDB can read a description from
3029 a local file or over the remote serial protocol.
3031 * Vectors of single-byte data use a new integer type which is not
3032 automatically displayed as character or string data.
3034 * The /s format now works with the print command. It displays
3035 arrays of single-byte integers and pointers to single-byte integers
3038 * Target descriptions can now describe target-specific registers,
3039 for architectures which have implemented the support (currently
3040 only ARM, M68K, and MIPS).
3042 * GDB and the GDB remote stub, gdbserver, now support the XScale
3045 * The GDB remote stub, gdbserver, has been updated to support
3046 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3047 has been rewritten to use the standard GDB remote protocol.
3049 * GDB can now step into C++ functions which are called through thunks.
3051 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3053 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3054 layout. It also supports a TextSeg= and DataSeg= response when only
3055 segment base addresses (rather than offsets) are available.
3057 * The /i format now outputs any trailing branch delay slot instructions
3058 immediately following the last instruction within the count specified.
3060 * The GDB remote protocol "T" stop reply packet now supports a
3061 "library" response. Combined with the new "qXfer:libraries:read"
3062 packet, this response allows GDB to debug shared libraries on targets
3063 where the operating system manages the list of loaded libraries (e.g.
3064 Windows and SymbianOS).
3066 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3067 (DLLs) on Windows and Windows CE targets.
3069 * GDB now supports a faster verification that a .debug file matches its binary
3070 according to its build-id signature, if the signature is present.
3076 Enable or disable hardware flow control (RTS/CTS) on the serial port
3077 when debugging using remote targets.
3079 set mem inaccessible-by-default
3080 show mem inaccessible-by-default
3081 If the target supplies a memory map, for instance via the remote
3082 protocol's "qXfer:memory-map:read" packet, setting this variable
3083 prevents GDB from accessing memory outside the memory map. This
3084 is useful for targets with memory mapped registers or which react
3085 badly to accesses of unmapped address space.
3087 set breakpoint auto-hw
3088 show breakpoint auto-hw
3089 If the target supplies a memory map, for instance via the remote
3090 protocol's "qXfer:memory-map:read" packet, setting this variable
3091 lets GDB use hardware breakpoints automatically for memory regions
3092 where it can not use software breakpoints. This covers both the
3093 "break" command and internal breakpoints used for other commands
3094 including "next" and "finish".
3097 catch exception unhandled
3098 Stop the program execution when Ada exceptions are raised.
3101 Stop the program execution when an Ada assertion failed.
3105 Set an alternate system root for target files. This is a more
3106 general version of "set solib-absolute-prefix", which is now
3107 an alias to "set sysroot".
3110 Provide extended SPU facility status information. This set of
3111 commands is available only when debugging the Cell/B.E. SPU
3114 * New native configurations
3116 OpenBSD/sh sh*-*openbsd*
3119 unset tdesc filename
3121 Use the specified local file as an XML target description, and do
3122 not query the target for its built-in description.
3126 OpenBSD/sh sh*-*-openbsd*
3127 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3128 Toshiba Media Processor mep-elf
3130 * New remote packets
3133 Ignore the specified signals; pass them directly to the debugged program
3134 without stopping other threads or reporting them to GDB.
3136 qXfer:features:read:
3137 Read an XML target description from the target, which describes its
3142 Read or write contents of an spufs file on the target system. These
3143 packets are available only on the Cell/B.E. SPU architecture.
3145 qXfer:libraries:read:
3146 Report the loaded shared libraries. Combined with new "T" packet
3147 response, this packet allows GDB to debug shared libraries on
3148 targets where the operating system manages the list of loaded
3149 libraries (e.g. Windows and SymbianOS).
3153 Support for these obsolete configurations has been removed.
3161 i[34567]86-*-lynxos*
3162 i[34567]86-*-netware*
3163 i[34567]86-*-sco3.2v5*
3164 i[34567]86-*-sco3.2v4*
3166 i[34567]86-*-sysv4.2*
3169 i[34567]86-*-unixware2*
3170 i[34567]86-*-unixware*
3179 * Other removed features
3186 Various m68k-only ROM monitors.
3193 Various Renesas ROM monitors and debugging interfaces for SH and
3198 Support for a Macraigor serial interface to on-chip debugging.
3199 GDB does not directly support the newer parallel or USB
3204 A debug information format. The predecessor to DWARF 2 and
3205 DWARF 3, which are still supported.
3207 Support for the HP aCC compiler on HP-UX/PA-RISC
3209 SOM-encapsulated symbolic debugging information, automatic
3210 invocation of pxdb, and the aCC custom C++ ABI. This does not
3211 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3212 with aCC can still be debugged on an assembly level.
3214 MIPS ".pdr" sections
3216 A MIPS-specific format used to describe stack frame layout
3217 in debugging information.
3221 GDB could work with an older version of Guile to debug
3222 the interpreter and Scheme programs running in it.
3224 set mips stack-arg-size
3225 set mips saved-gpreg-size
3227 Use "set mips abi" to control parameter passing for MIPS.
3229 *** Changes in GDB 6.6
3234 Cell Broadband Engine SPU spu-elf
3236 * GDB can now be configured as a cross-debugger targeting native Windows
3237 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3238 running on a Windows system over TCP/IP to debug Windows programs.
3240 * The GDB remote stub, gdbserver, has been updated to support Windows and
3241 Cygwin debugging. Both single-threaded and multi-threaded programs are
3244 * The "set trust-readonly-sections" command works again. This command was
3245 broken in GDB 6.3, 6.4, and 6.5.
3247 * The "load" command now supports writing to flash memory, if the remote
3248 stub provides the required support.
3250 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3251 longer requires symbolic debug information (e.g. DWARF-2).
3256 unset substitute-path
3257 show substitute-path
3258 Manage a list of substitution rules that GDB uses to rewrite the name
3259 of the directories where the sources are located. This can be useful
3260 for instance when the sources were moved to a different location
3261 between compilation and debugging.
3265 Print each CLI command as it is executed. Each command is prefixed with
3266 a number of `+' symbols representing the nesting depth.
3267 The source command now has a `-v' option to enable the same feature.
3271 The ARM Demon monitor support (RDP protocol, "target rdp").
3273 Kernel Object Display, an embedded debugging feature which only worked with
3274 an obsolete version of Cisco IOS.
3276 The 'set download-write-size' and 'show download-write-size' commands.
3278 * New remote packets
3281 Tell a stub about GDB client features, and request remote target features.
3282 The first feature implemented is PacketSize, which allows the target to
3283 specify the size of packets it can handle - to minimize the number of
3284 packets required and improve performance when connected to a remote
3288 Fetch an OS auxilliary vector from the remote stub. This packet is a
3289 more efficient replacement for qPart:auxv:read.
3291 qXfer:memory-map:read:
3292 Fetch a memory map from the remote stub, including information about
3293 RAM, ROM, and flash memory devices.
3298 Erase and program a flash memory device.
3300 * Removed remote packets
3303 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3304 used it, and only gdbserver implemented it.
3306 *** Changes in GDB 6.5
3310 Renesas M32C/M16C m32c-elf
3312 Morpho Technologies ms1 ms1-elf
3316 init-if-undefined Initialize a convenience variable, but
3317 only if it doesn't already have a value.
3319 The following commands are presently only implemented for native GNU/Linux:
3321 checkpoint Save a snapshot of the program state.
3323 restart <n> Return the program state to a
3324 previously saved state.
3326 info checkpoints List currently saved checkpoints.
3328 delete-checkpoint <n> Delete a previously saved checkpoint.
3330 set|show detach-on-fork Tell gdb whether to detach from a newly
3331 forked process, or to keep debugging it.
3333 info forks List forks of the user program that
3334 are available to be debugged.
3336 fork <n> Switch to debugging one of several
3337 forks of the user program that are
3338 available to be debugged.
3340 delete-fork <n> Delete a fork from the list of forks
3341 that are available to be debugged (and
3342 kill the forked process).
3344 detach-fork <n> Delete a fork from the list of forks
3345 that are available to be debugged (and
3346 allow the process to continue).
3350 Morpho Technologies ms2 ms1-elf
3352 * Improved Windows host support
3354 GDB now builds as a cross debugger hosted on i686-mingw32, including
3355 native console support, and remote communications using either
3356 network sockets or serial ports.
3358 * Improved Modula-2 language support
3360 GDB can now print most types in the Modula-2 syntax. This includes:
3361 basic types, set types, record types, enumerated types, range types,
3362 pointer types and ARRAY types. Procedure var parameters are correctly
3363 printed and hexadecimal addresses and character constants are also
3364 written in the Modula-2 syntax. Best results can be obtained by using
3365 GNU Modula-2 together with the -gdwarf-2 command line option.
3369 The ARM rdi-share module.
3371 The Netware NLM debug server.
3373 *** Changes in GDB 6.4
3375 * New native configurations
3377 OpenBSD/arm arm*-*-openbsd*
3378 OpenBSD/mips64 mips64-*-openbsd*
3382 Morpho Technologies ms1 ms1-elf
3384 * New command line options
3386 --batch-silent As for --batch, but totally silent.
3387 --return-child-result The debugger will exist with the same value
3388 the child (debugged) program exited with.
3389 --eval-command COMMAND, -ex COMMAND
3390 Execute a single GDB CLI command. This may be
3391 specified multiple times and in conjunction
3392 with the --command (-x) option.
3394 * Deprecated commands removed
3396 The following commands, that were deprecated in 2000, have been
3400 set|show arm disassembly-flavor set|show arm disassembler
3401 othernames set arm disassembler
3402 set|show remotedebug set|show debug remote
3403 set|show archdebug set|show debug arch
3404 set|show eventdebug set|show debug event
3407 * New BSD user-level threads support
3409 It is now possible to debug programs using the user-level threads
3410 library on OpenBSD and FreeBSD. Currently supported (target)
3413 FreeBSD/amd64 x86_64-*-freebsd*
3414 FreeBSD/i386 i386-*-freebsd*
3415 OpenBSD/i386 i386-*-openbsd*
3417 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3418 are not yet supported.
3420 * New support for Matsushita MN10300 w/sim added
3421 (Work in progress). mn10300-elf.
3423 * REMOVED configurations and files
3425 VxWorks and the XDR protocol *-*-vxworks
3426 Motorola MCORE mcore-*-*
3427 National Semiconductor NS32000 ns32k-*-*
3429 * New "set print array-indexes" command
3431 After turning this setting "on", GDB prints the index of each element
3432 when displaying arrays. The default is "off" to preserve the previous
3435 * VAX floating point support
3437 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3439 * User-defined command support
3441 In addition to using $arg0..$arg9 for argument passing, it is now possible
3442 to use $argc to determine now many arguments have been passed. See the
3443 section on user-defined commands in the user manual for more information.
3445 *** Changes in GDB 6.3:
3447 * New command line option
3449 GDB now accepts -l followed by a number to set the timeout for remote
3452 * GDB works with GCC -feliminate-dwarf2-dups
3454 GDB now supports a more compact representation of DWARF-2 debug
3455 information using DW_FORM_ref_addr references. These are produced
3456 by GCC with the option -feliminate-dwarf2-dups and also by some
3457 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3458 to use -feliminate-dwarf2-dups.
3460 * Internationalization
3462 When supported by the host system, GDB will be built with
3463 internationalization (libintl). The task of marking up the sources is
3464 continued, we're looking forward to our first translation.
3468 Initial support for debugging programs compiled with the GNAT
3469 implementation of the Ada programming language has been integrated
3470 into GDB. In this release, support is limited to expression evaluation.
3472 * New native configurations
3474 GNU/Linux/m32r m32r-*-linux-gnu
3478 GDB's remote protocol now includes support for the 'p' packet. This
3479 packet is used to fetch individual registers from a remote inferior.
3481 * END-OF-LIFE registers[] compatibility module
3483 GDB's internal register infrastructure has been completely rewritten.
3484 The new infrastructure making possible the implementation of key new
3485 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3488 GDB 6.3 will be the last release to include the the registers[]
3489 compatibility module that allowed out-of-date configurations to
3490 continue to work. This change directly impacts the following
3500 powerpc bdm protocol
3502 Unless there is activity to revive these configurations, they will be
3503 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3505 * OBSOLETE configurations and files
3507 Configurations that have been declared obsolete in this release have
3508 been commented out. Unless there is activity to revive these
3509 configurations, the next release of GDB will have their sources
3510 permanently REMOVED.
3519 *** Changes in GDB 6.2.1:
3521 * MIPS `break main; run' gave an heuristic-fence-post warning
3523 When attempting to run even a simple program, a warning about
3524 heuristic-fence-post being hit would be reported. This problem has
3527 * MIPS IRIX 'long double' crashed GDB
3529 When examining a long double variable, GDB would get a segmentation
3530 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3531 IRIX long double values).
3535 A bug in the VAX stack code was causing problems with the "next"
3536 command. This problem has been fixed.
3538 *** Changes in GDB 6.2:
3540 * Fix for ``many threads''
3542 On GNU/Linux systems that use the NPTL threads library, a program
3543 rapidly creating and deleting threads would confuse GDB leading to the
3546 ptrace: No such process.
3547 thread_db_get_info: cannot get thread info: generic error
3549 This problem has been fixed.
3551 * "-async" and "-noasync" options removed.
3553 Support for the broken "-noasync" option has been removed (it caused
3556 * New ``start'' command.
3558 This command runs the program until the begining of the main procedure.
3560 * New BSD Kernel Data Access Library (libkvm) interface
3562 Using ``target kvm'' it is now possible to debug kernel core dumps and
3563 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3564 platforms. Currently supported (native-only) configurations are:
3566 FreeBSD/amd64 x86_64-*-freebsd*
3567 FreeBSD/i386 i?86-*-freebsd*
3568 NetBSD/i386 i?86-*-netbsd*
3569 NetBSD/m68k m68*-*-netbsd*
3570 NetBSD/sparc sparc-*-netbsd*
3571 OpenBSD/amd64 x86_64-*-openbsd*
3572 OpenBSD/i386 i?86-*-openbsd*
3573 OpenBSD/m68k m68*-openbsd*
3574 OpenBSD/sparc sparc-*-openbsd*
3576 * Signal trampoline code overhauled
3578 Many generic problems with GDB's signal handling code have been fixed.
3579 These include: backtraces through non-contiguous stacks; recognition
3580 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3581 call; backtrace through a signal trampoline; step into and out of
3582 signal handlers; and single-stepping in the signal trampoline.
3584 Please note that kernel bugs are a limiting factor here. These
3585 features have been shown to work on an s390 GNU/Linux system that
3586 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3588 * Cygwin support for DWARF 2 added.
3590 * New native configurations
3592 GNU/Linux/hppa hppa*-*-linux*
3593 OpenBSD/hppa hppa*-*-openbsd*
3594 OpenBSD/m68k m68*-*-openbsd*
3595 OpenBSD/m88k m88*-*-openbsd*
3596 OpenBSD/powerpc powerpc-*-openbsd*
3597 NetBSD/vax vax-*-netbsd*
3598 OpenBSD/vax vax-*-openbsd*
3600 * END-OF-LIFE frame compatibility module
3602 GDB's internal frame infrastructure has been completely rewritten.
3603 The new infrastructure making it possible to support key new features
3604 including DWARF 2 Call Frame Information. To aid in the task of
3605 migrating old configurations to this new infrastructure, a
3606 compatibility module, that allowed old configurations to continue to
3607 work, was also included.
3609 GDB 6.2 will be the last release to include this frame compatibility
3610 module. This change directly impacts the following configurations:
3620 Unless there is activity to revive these configurations, they will be
3621 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3623 * REMOVED configurations and files
3625 Sun 3, running SunOS 3 m68*-*-sunos3*
3626 Sun 3, running SunOS 4 m68*-*-sunos4*
3627 Sun 2, running SunOS 3 m68000-*-sunos3*
3628 Sun 2, running SunOS 4 m68000-*-sunos4*
3629 Motorola 680x0 running LynxOS m68*-*-lynxos*
3630 AT&T 3b1/Unix pc m68*-att-*
3631 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3632 decstation mips-dec-* mips-little-*
3633 riscos mips-*-riscos* mips-*-sysv*
3634 sonymips mips-sony-*
3635 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3637 *** Changes in GDB 6.1.1:
3639 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3641 The TUI (Text-mode User Interface) is now built as part of a default
3642 GDB configuration. It is enabled by either selecting the TUI with the
3643 command line option "-i=tui" or by running the separate "gdbtui"
3644 program. For more information on the TUI, see the manual "Debugging
3647 * Pending breakpoint support (also included in GDB 6.1)
3649 Support has been added to allow you to specify breakpoints in shared
3650 libraries that have not yet been loaded. If a breakpoint location
3651 cannot be found, and the "breakpoint pending" option is set to auto,
3652 GDB queries you if you wish to make the breakpoint pending on a future
3653 shared-library load. If and when GDB resolves the breakpoint symbol,
3654 the pending breakpoint is removed as one or more regular breakpoints
3657 Pending breakpoints are very useful for GCJ Java debugging.
3659 * Fixed ISO-C build problems
3661 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3662 non ISO-C code that stopped them being built using a more strict ISO-C
3663 compiler (e.g., IBM's C compiler).
3665 * Fixed build problem on IRIX 5
3667 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3668 wasn't able to compile compile on an IRIX 5 system.
3670 * Added execute permission to gdb/gdbserver/configure
3672 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3673 permission. This bug would cause configure to fail on a number of
3674 systems (Solaris, IRIX). Ref: server/519.
3676 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3678 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3679 has been updated to use constant array sizes.
3681 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3683 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3684 its generated DWARF Call Frame Info. This encoding was causing GDB to
3685 panic, that panic has been fixed. Ref: gdb/1628.
3687 * Fixed a problem when examining parameters in shared library code.
3689 When examining parameters in optimized shared library code generated
3690 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3691 not available''. GDB now correctly displays the variable's value.
3693 *** Changes in GDB 6.1:
3695 * Removed --with-mmalloc
3697 Support for the mmalloc memory manager has been removed, as it
3698 conflicted with the internal gdb byte cache.
3700 * Changes in AMD64 configurations
3702 The AMD64 target now includes the %cs and %ss registers. As a result
3703 the AMD64 remote protocol has changed; this affects the floating-point
3704 and SSE registers. If you rely on those registers for your debugging,
3705 you should upgrade gdbserver on the remote side.
3707 * Revised SPARC target
3709 The SPARC target has been completely revised, incorporating the
3710 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3711 support for LynxOS and SunOS 4 has been dropped. Calling functions
3712 from within GDB on operating systems with a non-executable stack
3713 (Solaris, OpenBSD) now works.
3717 GDB has a new C++ demangler which does a better job on the mangled
3718 names generated by current versions of g++. It also runs faster, so
3719 with this and other changes gdb should now start faster on large C++
3722 * DWARF 2 Location Expressions
3724 GDB support for location expressions has been extended to support function
3725 arguments and frame bases. Older versions of GDB could crash when they
3728 * C++ nested types and namespaces
3730 GDB's support for nested types and namespaces in C++ has been
3731 improved, especially if you use the DWARF 2 debugging format. (This
3732 is the default for recent versions of GCC on most platforms.)
3733 Specifically, if you have a class "Inner" defined within a class or
3734 namespace "Outer", then GDB realizes that the class's name is
3735 "Outer::Inner", not simply "Inner". This should greatly reduce the
3736 frequency of complaints about not finding RTTI symbols. In addition,
3737 if you are stopped at inside of a function defined within a namespace,
3738 GDB modifies its name lookup accordingly.
3740 * New native configurations
3742 NetBSD/amd64 x86_64-*-netbsd*
3743 OpenBSD/amd64 x86_64-*-openbsd*
3744 OpenBSD/alpha alpha*-*-openbsd*
3745 OpenBSD/sparc sparc-*-openbsd*
3746 OpenBSD/sparc64 sparc64-*-openbsd*
3748 * New debugging protocols
3750 M32R with SDI protocol m32r-*-elf*
3752 * "set prompt-escape-char" command deleted.
3754 The command "set prompt-escape-char" has been deleted. This command,
3755 and its very obscure effet on GDB's prompt, was never documented,
3756 tested, nor mentioned in the NEWS file.
3758 * OBSOLETE configurations and files
3760 Configurations that have been declared obsolete in this release have
3761 been commented out. Unless there is activity to revive these
3762 configurations, the next release of GDB will have their sources
3763 permanently REMOVED.
3765 Sun 3, running SunOS 3 m68*-*-sunos3*
3766 Sun 3, running SunOS 4 m68*-*-sunos4*
3767 Sun 2, running SunOS 3 m68000-*-sunos3*
3768 Sun 2, running SunOS 4 m68000-*-sunos4*
3769 Motorola 680x0 running LynxOS m68*-*-lynxos*
3770 AT&T 3b1/Unix pc m68*-att-*
3771 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3772 decstation mips-dec-* mips-little-*
3773 riscos mips-*-riscos* mips-*-sysv*
3774 sonymips mips-sony-*
3775 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3777 * REMOVED configurations and files
3779 SGI Irix-4.x mips-sgi-irix4 or iris4
3780 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3781 Z8000 simulator z8k-zilog-none or z8ksim
3782 Matsushita MN10200 w/simulator mn10200-*-*
3783 H8/500 simulator h8500-hitachi-hms or h8500hms
3784 HP/PA running BSD hppa*-*-bsd*
3785 HP/PA running OSF/1 hppa*-*-osf*
3786 HP/PA Pro target hppa*-*-pro*
3787 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3788 386BSD i[3456]86-*-bsd*
3789 Sequent family i[3456]86-sequent-sysv4*
3790 i[3456]86-sequent-sysv*
3791 i[3456]86-sequent-bsd*
3792 SPARC running LynxOS sparc-*-lynxos*
3793 SPARC running SunOS 4 sparc-*-sunos4*
3794 Tsqware Sparclet sparclet-*-*
3795 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3797 *** Changes in GDB 6.0:
3801 Support for debugging the Objective-C programming language has been
3802 integrated into GDB.
3804 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3806 DWARF 2's Call Frame Information makes available compiler generated
3807 information that more exactly describes the program's run-time stack.
3808 By using this information, GDB is able to provide more robust stack
3811 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3812 have been updated to use a new backtrace mechanism which includes
3813 DWARF 2 CFI support.
3817 GDB's remote protocol has been extended to include support for hosted
3818 file I/O (where the remote target uses GDB's file system). See GDB's
3819 remote protocol documentation for details.
3821 * All targets using the new architecture framework.
3823 All of GDB's targets have been updated to use the new internal
3824 architecture framework. The way is now open for future GDB releases
3825 to include cross-architecture native debugging support (i386 on amd64,
3828 * GNU/Linux's Thread Local Storage (TLS)
3830 GDB now includes support for for the GNU/Linux implementation of
3831 per-thread variables.
3833 * GNU/Linux's Native POSIX Thread Library (NPTL)
3835 GDB's thread code has been updated to work with either the new
3836 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3838 * Separate debug info.
3840 GDB, in conjunction with BINUTILS, now supports a mechanism for
3841 automatically loading debug information from a separate file. Instead
3842 of shipping full debug and non-debug versions of system libraries,
3843 system integrators can now instead ship just the stripped libraries
3844 and optional debug files.
3846 * DWARF 2 Location Expressions
3848 DWARF 2 Location Expressions allow the compiler to more completely
3849 describe the location of variables (even in optimized code) to the
3852 GDB now includes preliminary support for location expressions (support
3853 for DW_OP_piece is still missing).
3857 A number of long standing bugs that caused GDB to die while starting a
3858 Java application have been fixed. GDB's Java support is now
3859 considered "useable".
3861 * GNU/Linux support for fork, vfork, and exec.
3863 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3864 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3867 * GDB supports logging output to a file
3869 There are two new commands, "set logging" and "show logging", which can be
3870 used to capture GDB's output to a file.
3872 * The meaning of "detach" has changed for gdbserver
3874 The "detach" command will now resume the application, as documented. To
3875 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3878 * d10v, m68hc11 `regs' command deprecated
3880 The `info registers' command has been updated so that it displays the
3881 registers using a format identical to the old `regs' command.
3885 A new command, "maint set profile on/off", has been added. This command can
3886 be used to enable or disable profiling while running GDB, to profile a
3887 session or a set of commands. In addition there is a new configure switch,
3888 "--enable-profiling", which will cause GDB to be compiled with profiling
3889 data, for more informative profiling results.
3891 * Default MI syntax changed to "mi2".
3893 The default MI (machine interface) syntax, enabled by the command line
3894 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3895 "mi1", can be enabled by specifying the option "-i=mi1".
3897 Support for the original "mi0" syntax (included in GDB 5.0) has been
3900 Fix for gdb/192: removed extraneous space when displaying frame level.
3901 Fix for gdb/672: update changelist is now output in mi list format.
3902 Fix for gdb/702: a -var-assign that updates the value now shows up
3903 in a subsequent -var-update.
3905 * New native configurations.
3907 FreeBSD/amd64 x86_64-*-freebsd*
3909 * Multi-arched targets.
3911 HP/PA HPUX11 hppa*-*-hpux*
3912 Renesas M32R/D w/simulator m32r-*-elf*
3914 * OBSOLETE configurations and files
3916 Configurations that have been declared obsolete in this release have
3917 been commented out. Unless there is activity to revive these
3918 configurations, the next release of GDB will have their sources
3919 permanently REMOVED.
3921 Z8000 simulator z8k-zilog-none or z8ksim
3922 Matsushita MN10200 w/simulator mn10200-*-*
3923 H8/500 simulator h8500-hitachi-hms or h8500hms
3924 HP/PA running BSD hppa*-*-bsd*
3925 HP/PA running OSF/1 hppa*-*-osf*
3926 HP/PA Pro target hppa*-*-pro*
3927 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3928 Sequent family i[3456]86-sequent-sysv4*
3929 i[3456]86-sequent-sysv*
3930 i[3456]86-sequent-bsd*
3931 Tsqware Sparclet sparclet-*-*
3932 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3934 * REMOVED configurations and files
3937 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3938 IBM AIX PS/2 i[3456]86-*-aix
3939 i386 running Mach 3.0 i[3456]86-*-mach3*
3940 i386 running Mach i[3456]86-*-mach*
3941 i386 running OSF/1 i[3456]86-*osf1mk*
3942 HP/Apollo 68k Family m68*-apollo*-sysv*,
3944 m68*-hp-bsd*, m68*-hp-hpux*
3945 Argonaut Risc Chip (ARC) arc-*-*
3946 Mitsubishi D30V d30v-*-*
3947 Fujitsu FR30 fr30-*-elf*
3948 OS/9000 i[34]86-*-os9k
3949 I960 with MON960 i960-*-coff
3951 * MIPS $fp behavior changed
3953 The convenience variable $fp, for the MIPS, now consistently returns
3954 the address of the current frame's base. Previously, depending on the
3955 context, $fp could refer to either $sp or the current frame's base
3956 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3957 The GNU Source-Level Debugger''.
3959 *** Changes in GDB 5.3:
3961 * GNU/Linux shared library multi-threaded performance improved.
3963 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3964 `/proc', in preference to `ptrace' for memory reads. This may result
3965 in an improvement in the start-up time of multi-threaded, shared
3966 library applications when run under GDB. One GDB user writes: ``loads
3967 shared libs like mad''.
3969 * ``gdbserver'' now supports multi-threaded applications on some targets
3971 Support for debugging multi-threaded applications which use
3972 the GNU/Linux LinuxThreads package has been added for
3973 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3974 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3976 * GDB now supports C/C++ preprocessor macros.
3978 GDB now expands preprocessor macro invocations in C/C++ expressions,
3979 and provides various commands for showing macro definitions and how
3982 The new command `macro expand EXPRESSION' expands any macro
3983 invocations in expression, and shows the result.
3985 The new command `show macro MACRO-NAME' shows the definition of the
3986 macro named MACRO-NAME, and where it was defined.
3988 Most compilers don't include information about macros in the debugging
3989 information by default. In GCC 3.1, for example, you need to compile
3990 your program with the options `-gdwarf-2 -g3'. If the macro
3991 information is present in the executable, GDB will read it.
3993 * Multi-arched targets.
3995 DEC Alpha (partial) alpha*-*-*
3996 DEC VAX (partial) vax-*-*
3998 National Semiconductor NS32000 (partial) ns32k-*-*
3999 Motorola 68000 (partial) m68k-*-*
4000 Motorola MCORE mcore-*-*
4004 Fujitsu FRV architecture added by Red Hat frv*-*-*
4007 * New native configurations
4009 Alpha NetBSD alpha*-*-netbsd*
4010 SH NetBSD sh*-*-netbsdelf*
4011 MIPS NetBSD mips*-*-netbsd*
4012 UltraSPARC NetBSD sparc64-*-netbsd*
4014 * OBSOLETE configurations and files
4016 Configurations that have been declared obsolete in this release have
4017 been commented out. Unless there is activity to revive these
4018 configurations, the next release of GDB will have their sources
4019 permanently REMOVED.
4021 Mitsubishi D30V d30v-*-*
4022 OS/9000 i[34]86-*-os9k
4023 IBM AIX PS/2 i[3456]86-*-aix
4024 Fujitsu FR30 fr30-*-elf*
4025 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4026 Argonaut Risc Chip (ARC) arc-*-*
4027 i386 running Mach 3.0 i[3456]86-*-mach3*
4028 i386 running Mach i[3456]86-*-mach*
4029 i386 running OSF/1 i[3456]86-*osf1mk*
4030 HP/Apollo 68k Family m68*-apollo*-sysv*,
4032 m68*-hp-bsd*, m68*-hp-hpux*
4033 I960 with MON960 i960-*-coff
4035 * OBSOLETE languages
4037 CHILL, a Pascal like language used by telecommunications companies.
4039 * REMOVED configurations and files
4041 AMD 29k family via UDI a29k-amd-udi, udi29k
4042 A29K VxWorks a29k-*-vxworks
4043 AMD 29000 embedded, using EBMON a29k-none-none
4044 AMD 29000 embedded with COFF a29k-none-coff
4045 AMD 29000 embedded with a.out a29k-none-aout
4047 testsuite/gdb.hp/gdb.threads-hp/ directory
4049 * New command "set max-user-call-depth <nnn>"
4051 This command allows the user to limit the call depth of user-defined
4052 commands. The default is 1024.
4054 * Changes in FreeBSD/i386 native debugging.
4056 Support for the "generate-core-file" has been added.
4058 * New commands "dump", "append", and "restore".
4060 These commands allow data to be copied from target memory
4061 to a bfd-format or binary file (dump and append), and back
4062 from a file into memory (restore).
4064 * Improved "next/step" support on multi-processor Alpha Tru64.
4066 The previous single-step mechanism could cause unpredictable problems,
4067 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4068 of a software single-step mechanism prevents this.
4070 *** Changes in GDB 5.2.1:
4078 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4079 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4080 Fix, by Joel Brobecker imported from mainline.
4082 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4083 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4084 Fix, by Fred Fish, imported from mainline.
4086 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4087 Surprisingly enough, it works now.
4088 By Michal Ludvig, imported from mainline.
4090 i386 hardware watchpoint support:
4091 avoid misses on second run for some targets.
4092 By Pierre Muller, imported from mainline.
4094 *** Changes in GDB 5.2:
4096 * New command "set trust-readonly-sections on[off]".
4098 This command is a hint that tells gdb that read-only sections
4099 really are read-only (ie. that their contents will not change).
4100 In this mode, gdb will go to the object file rather than the
4101 target to read memory from read-only sections (such as ".text").
4102 This can be a significant performance improvement on some
4103 (notably embedded) targets.
4105 * New command "generate-core-file" (or "gcore").
4107 This new gdb command allows the user to drop a core file of the child
4108 process state at any time. So far it's been implemented only for
4109 GNU/Linux and Solaris, but should be relatively easily ported to other
4110 hosts. Argument is core file name (defaults to core.<pid>).
4112 * New command line option
4114 GDB now accepts --pid or -p followed by a process id.
4116 * Change in command line behavior -- corefiles vs. process ids.
4118 There is a subtle behavior in the way in which GDB handles
4119 command line arguments. The first non-flag argument is always
4120 a program to debug, but the second non-flag argument may either
4121 be a corefile or a process id. Previously, GDB would attempt to
4122 open the second argument as a corefile, and if that failed, would
4123 issue a superfluous error message and then attempt to attach it as
4124 a process. Now, if the second argument begins with a non-digit,
4125 it will be treated as a corefile. If it begins with a digit,
4126 GDB will attempt to attach it as a process, and if no such process
4127 is found, will then attempt to open it as a corefile.
4129 * Changes in ARM configurations.
4131 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4132 configuration is fully multi-arch.
4134 * New native configurations
4136 ARM NetBSD arm*-*-netbsd*
4137 x86 OpenBSD i[3456]86-*-openbsd*
4138 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4139 Sparc64 running FreeBSD sparc64-*-freebsd*
4143 Sanyo XStormy16 xstormy16-elf
4145 * OBSOLETE configurations and files
4147 Configurations that have been declared obsolete in this release have
4148 been commented out. Unless there is activity to revive these
4149 configurations, the next release of GDB will have their sources
4150 permanently REMOVED.
4152 AMD 29k family via UDI a29k-amd-udi, udi29k
4153 A29K VxWorks a29k-*-vxworks
4154 AMD 29000 embedded, using EBMON a29k-none-none
4155 AMD 29000 embedded with COFF a29k-none-coff
4156 AMD 29000 embedded with a.out a29k-none-aout
4158 testsuite/gdb.hp/gdb.threads-hp/ directory
4160 * REMOVED configurations and files
4162 TI TMS320C80 tic80-*-*
4164 PowerPC Solaris powerpcle-*-solaris*
4165 PowerPC Windows NT powerpcle-*-cygwin32
4166 PowerPC Netware powerpc-*-netware*
4167 Harris/CXUX m88k m88*-harris-cxux*
4168 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4169 ns32k-utek-sysv* ns32k-utek-*
4170 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4171 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4172 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4173 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4174 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4176 * Changes to command line processing
4178 The new `--args' feature can be used to specify command-line arguments
4179 for the inferior from gdb's command line.
4181 * Changes to key bindings
4183 There is a new `operate-and-get-next' function bound to `C-o'.
4185 *** Changes in GDB 5.1.1
4187 Fix compile problem on DJGPP.
4189 Fix a problem with floating-point registers on the i386 being
4192 Fix to stop GDB crashing on .debug_str debug info.
4194 Numerous documentation fixes.
4196 Numerous testsuite fixes.
4198 *** Changes in GDB 5.1:
4200 * New native configurations
4202 Alpha FreeBSD alpha*-*-freebsd*
4203 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4204 MIPS GNU/Linux mips*-*-linux*
4205 MIPS SGI Irix 6.x mips*-sgi-irix6*
4206 ia64 AIX ia64-*-aix*
4207 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4211 Motorola 68HC11 and 68HC12 m68hc11-elf
4213 UltraSparc running GNU/Linux sparc64-*-linux*
4215 * OBSOLETE configurations and files
4217 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4218 Harris/CXUX m88k m88*-harris-cxux*
4219 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4220 ns32k-utek-sysv* ns32k-utek-*
4221 TI TMS320C80 tic80-*-*
4223 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4224 PowerPC Solaris powerpcle-*-solaris*
4225 PowerPC Windows NT powerpcle-*-cygwin32
4226 PowerPC Netware powerpc-*-netware*
4227 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4228 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4229 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4230 Apple Macintosh (MPW) host N/A
4232 stuff.c (Program to stuff files into a specially prepared space in kdb)
4233 kdb-start.c (Main loop for the standalone kernel debugger)
4235 Configurations that have been declared obsolete in this release have
4236 been commented out. Unless there is activity to revive these
4237 configurations, the next release of GDB will have their sources
4238 permanently REMOVED.
4240 * REMOVED configurations and files
4242 Altos 3068 m68*-altos-*
4243 Convex c1-*-*, c2-*-*
4245 ARM RISCix arm-*-* (as host)
4249 * GDB has been converted to ISO C.
4251 GDB's source code has been converted to ISO C. In particular, the
4252 sources are fully protoized, and rely on standard headers being
4257 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4259 * The MI enabled by default.
4261 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4262 revised and enabled by default. Packages which use GDB as a debugging
4263 engine behind a UI or another front end are encouraged to switch to
4264 using the GDB/MI interface, instead of the old annotations interface
4265 which is now deprecated.
4267 * Support for debugging Pascal programs.
4269 GDB now includes support for debugging Pascal programs. The following
4270 main features are supported:
4272 - Pascal-specific data types such as sets;
4274 - automatic recognition of Pascal sources based on file-name
4277 - Pascal-style display of data types, variables, and functions;
4279 - a Pascal expression parser.
4281 However, some important features are not yet supported.
4283 - Pascal string operations are not supported at all;
4285 - there are some problems with boolean types;
4287 - Pascal type hexadecimal constants are not supported
4288 because they conflict with the internal variables format;
4290 - support for Pascal objects and classes is not full yet;
4292 - unlike Pascal, GDB is case-sensitive for symbol names.
4294 * Changes in completion.
4296 Commands such as `shell', `run' and `set args', which pass arguments
4297 to inferior programs, now complete on file names, similar to what
4298 users expect at the shell prompt.
4300 Commands which accept locations, such as `disassemble', `print',
4301 `breakpoint', `until', etc. now complete on filenames as well as
4302 program symbols. Thus, if you type "break foob TAB", and the source
4303 files linked into the programs include `foobar.c', that file name will
4304 be one of the candidates for completion. However, file names are not
4305 considered for completion after you typed a colon that delimits a file
4306 name from a name of a function in that file, as in "break foo.c:bar".
4308 `set demangle-style' completes on available demangling styles.
4310 * New platform-independent commands:
4312 It is now possible to define a post-hook for a command as well as a
4313 hook that runs before the command. For more details, see the
4314 documentation of `hookpost' in the GDB manual.
4316 * Changes in GNU/Linux native debugging.
4318 Support for debugging multi-threaded programs has been completely
4319 revised for all platforms except m68k and sparc. You can now debug as
4320 many threads as your system allows you to have.
4322 Attach/detach is supported for multi-threaded programs.
4324 Support for SSE registers was added for x86. This doesn't work for
4325 multi-threaded programs though.
4327 * Changes in MIPS configurations.
4329 Multi-arch support is enabled for all MIPS configurations.
4331 GDB can now be built as native debugger on SGI Irix 6.x systems for
4332 debugging n32 executables. (Debugging 64-bit executables is not yet
4335 * Unified support for hardware watchpoints in all x86 configurations.
4337 Most (if not all) native x86 configurations support hardware-assisted
4338 breakpoints and watchpoints in a unified manner. This support
4339 implements debug register sharing between watchpoints, which allows to
4340 put a virtually infinite number of watchpoints on the same address,
4341 and also supports watching regions up to 16 bytes with several debug
4344 The new maintenance command `maintenance show-debug-regs' toggles
4345 debugging print-outs in functions that insert, remove, and test
4346 watchpoints and hardware breakpoints.
4348 * Changes in the DJGPP native configuration.
4350 New command ``info dos sysinfo'' displays assorted information about
4351 the CPU, OS, memory, and DPMI server.
4353 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4354 display information about segment descriptors stored in GDT, LDT, and
4357 New commands ``info dos pde'' and ``info dos pte'' display entries
4358 from Page Directory and Page Tables (for now works with CWSDPMI only).
4359 New command ``info dos address-pte'' displays the Page Table entry for
4360 a given linear address.
4362 GDB can now pass command lines longer than 126 characters to the
4363 program being debugged (requires an update to the libdbg.a library
4364 which is part of the DJGPP development kit).
4366 DWARF2 debug info is now supported.
4368 It is now possible to `step' and `next' through calls to `longjmp'.
4370 * Changes in documentation.
4372 All GDB documentation was converted to GFDL, the GNU Free
4373 Documentation License.
4375 Tracepoints-related commands are now fully documented in the GDB
4378 TUI, the Text-mode User Interface, is now documented in the manual.
4380 Tracepoints-related commands are now fully documented in the GDB
4383 The "GDB Internals" manual now has an index. It also includes
4384 documentation of `ui_out' functions, GDB coding standards, x86
4385 hardware watchpoints, and memory region attributes.
4387 * GDB's version number moved to ``version.in''
4389 The Makefile variable VERSION has been replaced by the file
4390 ``version.in''. People creating GDB distributions should update the
4391 contents of this file.
4395 GUD support is now a standard part of the EMACS distribution.
4397 *** Changes in GDB 5.0:
4399 * Improved support for debugging FP programs on x86 targets
4401 Unified and much-improved support for debugging floating-point
4402 programs on all x86 targets. In particular, ``info float'' now
4403 displays the FP registers in the same format on all x86 targets, with
4404 greater level of detail.
4406 * Improvements and bugfixes in hardware-assisted watchpoints
4408 It is now possible to watch array elements, struct members, and
4409 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4410 on x86 targets no longer erroneously trigger when the address is
4413 * Improvements in the native DJGPP version of GDB
4415 The distribution now includes all the scripts and auxiliary files
4416 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4417 machines ``out of the box''.
4419 The DJGPP version can now debug programs that use signals. It is
4420 possible to catch signals that happened in the debuggee, deliver
4421 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4422 would kill the program being debugged.) Programs that hook hardware
4423 interrupts (keyboard, timer, etc.) can also be debugged.
4425 It is now possible to debug DJGPP programs that redirect their
4426 standard handles or switch them to raw (as opposed to cooked) mode, or
4427 even close them. The command ``run < foo > bar'' works as expected,
4428 and ``info terminal'' reports useful information about the debuggee's
4429 terminal, including raw/cooked mode, redirection, etc.
4431 The DJGPP version now uses termios functions for console I/O, which
4432 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4435 DOS-style file names with drive letters are now fully supported by
4438 It is now possible to debug DJGPP programs that switch their working
4439 directory. It is also possible to rerun the debuggee any number of
4440 times without restarting GDB; thus, you can use the same setup,
4441 breakpoints, etc. for many debugging sessions.
4443 * New native configurations
4445 ARM GNU/Linux arm*-*-linux*
4446 PowerPC GNU/Linux powerpc-*-linux*
4450 Motorola MCore mcore-*-*
4451 x86 VxWorks i[3456]86-*-vxworks*
4452 PowerPC VxWorks powerpc-*-vxworks*
4453 TI TMS320C80 tic80-*-*
4455 * OBSOLETE configurations
4457 Altos 3068 m68*-altos-*
4458 Convex c1-*-*, c2-*-*
4460 ARM RISCix arm-*-* (as host)
4463 Configurations that have been declared obsolete will be commented out,
4464 but the code will be left in place. If there is no activity to revive
4465 these configurations before the next release of GDB, the sources will
4466 be permanently REMOVED.
4468 * Gould support removed
4470 Support for the Gould PowerNode and NP1 has been removed.
4472 * New features for SVR4
4474 On SVR4 native platforms (such as Solaris), if you attach to a process
4475 without first loading a symbol file, GDB will now attempt to locate and
4476 load symbols from the running process's executable file.
4478 * Many C++ enhancements
4480 C++ support has been greatly improved. Overload resolution now works properly
4481 in almost all cases. RTTI support is on the way.
4483 * Remote targets can connect to a sub-program
4485 A popen(3) style serial-device has been added. This device starts a
4486 sub-process (such as a stand-alone simulator) and then communicates
4487 with that. The sub-program to run is specified using the syntax
4488 ``|<program> <args>'' vis:
4490 (gdb) set remotedebug 1
4491 (gdb) target extended-remote |mn10300-elf-sim program-args
4493 * MIPS 64 remote protocol
4495 A long standing bug in the mips64 remote protocol where by GDB
4496 expected certain 32 bit registers (ex SR) to be transfered as 32
4497 instead of 64 bits has been fixed.
4499 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4500 added to provide backward compatibility with older versions of GDB.
4502 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4504 The command ``set remotebinarydownload'' command has been replaced by
4505 ``set remote X-packet''. Other commands in ``set remote'' family
4506 include ``set remote P-packet''.
4508 * Breakpoint commands accept ranges.
4510 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4511 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4512 ``tracepoint passcount'' also accepts a range of tracepoints.
4514 * ``apropos'' command added.
4516 The ``apropos'' command searches through command names and
4517 documentation strings, printing out matches, making it much easier to
4518 try to find a command that does what you are looking for.
4522 A new machine oriented interface (MI) has been added to GDB. This
4523 interface is designed for debug environments running GDB as a separate
4524 process. This is part of the long term libGDB project. See the
4525 "GDB/MI" chapter of the GDB manual for further information. It can be
4526 enabled by configuring with:
4528 .../configure --enable-gdbmi
4530 *** Changes in GDB-4.18:
4532 * New native configurations
4534 HP-UX 10.20 hppa*-*-hpux10.20
4535 HP-UX 11.x hppa*-*-hpux11.0*
4536 M68K GNU/Linux m68*-*-linux*
4540 Fujitsu FR30 fr30-*-elf*
4541 Intel StrongARM strongarm-*-*
4542 Mitsubishi D30V d30v-*-*
4544 * OBSOLETE configurations
4546 Gould PowerNode, NP1 np1-*-*, pn-*-*
4548 Configurations that have been declared obsolete will be commented out,
4549 but the code will be left in place. If there is no activity to revive
4550 these configurations before the next release of GDB, the sources will
4551 be permanently REMOVED.
4555 As a compatibility experiment, GDB's source files buildsym.h and
4556 buildsym.c have been converted to pure standard C, no longer
4557 containing any K&R compatibility code. We believe that all systems in
4558 use today either come with a standard C compiler, or have a GCC port
4559 available. If this is not true, please report the affected
4560 configuration to bug-gdb@gnu.org immediately. See the README file for
4561 information about getting a standard C compiler if you don't have one
4566 GDB now uses readline 2.2.
4568 * set extension-language
4570 You can now control the mapping between filename extensions and source
4571 languages by using the `set extension-language' command. For instance,
4572 you can ask GDB to treat .c files as C++ by saying
4573 set extension-language .c c++
4574 The command `info extensions' lists all of the recognized extensions
4575 and their associated languages.
4577 * Setting processor type for PowerPC and RS/6000
4579 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4580 you can use the `set processor' command to specify what variant of the
4581 PowerPC family you are debugging. The command
4585 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4586 following PowerPC and RS6000 variants:
4588 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4589 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4591 403GC IBM PowerPC 403GC
4592 505 Motorola PowerPC 505
4593 860 Motorola PowerPC 860 or 850
4594 601 Motorola PowerPC 601
4595 602 Motorola PowerPC 602
4596 603 Motorola/IBM PowerPC 603 or 603e
4597 604 Motorola PowerPC 604 or 604e
4598 750 Motorola/IBM PowerPC 750 or 750
4600 At the moment, this command just tells GDB what to name the
4601 special-purpose processor registers. Since almost all the affected
4602 registers are inaccessible to user-level programs, this command is
4603 only useful for remote debugging in its present form.
4607 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4608 more extensive support for HP-UX. Added features include shared
4609 library support, kernel threads and hardware watchpoints for 11.00,
4610 support for HP's ANSI C and C++ compilers, and a compatibility mode
4611 for xdb and dbx commands.
4615 HP's donation includes the new concept of catchpoints, which is a
4616 generalization of the old catch command. On HP-UX, it is now possible
4617 to catch exec, fork, and vfork, as well as library loading.
4619 This means that the existing catch command has changed; its first
4620 argument now specifies the type of catch to be set up. See the
4621 output of "help catch" for a list of catchpoint types.
4623 * Debugging across forks
4625 On HP-UX, you can choose which process to debug when a fork() happens
4630 HP has donated a curses-based terminal user interface (TUI). To get
4631 it, build with --enable-tui. Although this can be enabled for any
4632 configuration, at present it only works for native HP debugging.
4634 * GDB remote protocol additions
4636 A new protocol packet 'X' that writes binary data is now available.
4637 Default behavior is to try 'X', then drop back to 'M' if the stub
4638 fails to respond. The settable variable `remotebinarydownload'
4639 allows explicit control over the use of 'X'.
4641 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4642 full 64-bit address. The command
4644 set remoteaddresssize 32
4646 can be used to revert to the old behaviour. For existing remote stubs
4647 the change should not be noticed, as the additional address information
4650 In order to assist in debugging stubs, you may use the maintenance
4651 command `packet' to send any text string to the stub. For instance,
4653 maint packet heythere
4655 sends the packet "$heythere#<checksum>". Note that it is very easy to
4656 disrupt a debugging session by sending the wrong packet at the wrong
4659 The compare-sections command allows you to compare section data on the
4660 target to what is in the executable file without uploading or
4661 downloading, by comparing CRC checksums.
4663 * Tracing can collect general expressions
4665 You may now collect general expressions at tracepoints. This requires
4666 further additions to the target-side stub; see tracepoint.c and
4667 doc/agentexpr.texi for further details.
4669 * mask-address variable for Mips
4671 For Mips targets, you may control the zeroing of the upper 32 bits of
4672 a 64-bit address by entering `set mask-address on'. This is mainly
4673 of interest to users of embedded R4xxx and R5xxx processors.
4675 * Higher serial baud rates
4677 GDB's serial code now allows you to specify baud rates 57600, 115200,
4678 230400, and 460800 baud. (Note that your host system may not be able
4679 to achieve all of these rates.)
4683 The i960 configuration now includes an initial implementation of a
4684 builtin simulator, contributed by Jim Wilson.
4687 *** Changes in GDB-4.17:
4689 * New native configurations
4691 Alpha GNU/Linux alpha*-*-linux*
4692 Unixware 2.x i[3456]86-unixware2*
4693 Irix 6.x mips*-sgi-irix6*
4694 PowerPC GNU/Linux powerpc-*-linux*
4695 PowerPC Solaris powerpcle-*-solaris*
4696 Sparc GNU/Linux sparc-*-linux*
4697 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4701 Argonaut Risc Chip (ARC) arc-*-*
4702 Hitachi H8/300S h8300*-*-*
4703 Matsushita MN10200 w/simulator mn10200-*-*
4704 Matsushita MN10300 w/simulator mn10300-*-*
4705 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4706 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4707 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4708 Mitsubishi D10V w/simulator d10v-*-*
4709 Mitsubishi M32R/D w/simulator m32r-*-elf*
4710 Tsqware Sparclet sparclet-*-*
4711 NEC V850 w/simulator v850-*-*
4713 * New debugging protocols
4715 ARM with RDI protocol arm*-*-*
4716 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4717 DDB and LSI variants of PMON protocol mips*-*-*
4718 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4719 PowerPC with SDS protocol powerpc{,le}-*-eabi
4720 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4724 All configurations can now understand and use the DWARF 2 debugging
4725 format. The choice is automatic, if the symbol file contains DWARF 2
4730 GDB now includes basic Java language support. This support is
4731 only useful with Java compilers that produce native machine code.
4733 * solib-absolute-prefix and solib-search-path
4735 For SunOS and SVR4 shared libraries, you may now set the prefix for
4736 loading absolute shared library symbol files, and the search path for
4737 locating non-absolute shared library symbol files.
4739 * Live range splitting
4741 GDB can now effectively debug code for which GCC has performed live
4742 range splitting as part of its optimization. See gdb/doc/LRS for
4743 more details on the expected format of the stabs information.
4747 GDB's support for the GNU Hurd, including thread debugging, has been
4748 updated to work with current versions of the Hurd.
4752 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4753 instruction set. ARM GDB automatically detects when Thumb
4754 instructions are in use, and adjusts disassembly and backtracing
4759 GDB's MIPS target configurations now handle the MIP16 16-bit
4764 GDB now includes support for overlays; if an executable has been
4765 linked such that multiple sections are based at the same address, GDB
4766 will decide which section to use for symbolic info. You can choose to
4767 control the decision manually, using overlay commands, or implement
4768 additional target-side support and use "overlay load-target" to bring
4769 in the overlay mapping. Do "help overlay" for more detail.
4773 The command "info symbol <address>" displays information about
4774 the symbol at the specified address.
4778 The standard remote protocol now includes an extension that allows
4779 asynchronous collection and display of trace data. This requires
4780 extensive support in the target-side debugging stub. Tracing mode
4781 includes a new interaction mode in GDB and new commands: see the
4782 file tracepoint.c for more details.
4786 Configurations for embedded MIPS now include a simulator contributed
4787 by Cygnus Solutions. The simulator supports the instruction sets
4788 of most MIPS variants.
4792 Sparc configurations may now include the ERC32 simulator contributed
4793 by the European Space Agency. The simulator is not built into
4794 Sparc targets by default; configure with --enable-sim to include it.
4798 For target configurations that may include multiple variants of a
4799 basic architecture (such as MIPS and SH), you may now set the
4800 architecture explicitly. "set arch" sets, "info arch" lists
4801 the possible architectures.
4803 *** Changes in GDB-4.16:
4805 * New native configurations
4807 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4808 M68K NetBSD m68k-*-netbsd*
4809 PowerPC AIX 4.x powerpc-*-aix*
4810 PowerPC MacOS powerpc-*-macos*
4811 PowerPC Windows NT powerpcle-*-cygwin32
4812 RS/6000 AIX 4.x rs6000-*-aix4*
4816 ARM with RDP protocol arm-*-*
4817 I960 with MON960 i960-*-coff
4818 MIPS VxWorks mips*-*-vxworks*
4819 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4820 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4822 Matra Sparclet sparclet-*-*
4826 The powerpc-eabi configuration now includes the PSIM simulator,
4827 contributed by Andrew Cagney, with assistance from Mike Meissner.
4828 PSIM is a very elaborate model of the PowerPC, including not only
4829 basic instruction set execution, but also details of execution unit
4830 performance and I/O hardware. See sim/ppc/README for more details.
4834 GDB now works with Solaris 2.5.
4836 * Windows 95/NT native
4838 GDB will now work as a native debugger on Windows 95 and Windows NT.
4839 To build it from source, you must use the "gnu-win32" environment,
4840 which uses a DLL to emulate enough of Unix to run the GNU tools.
4841 Further information, binaries, and sources are available at
4842 ftp.cygnus.com, under pub/gnu-win32.
4844 * dont-repeat command
4846 If a user-defined command includes the command `dont-repeat', then the
4847 command will not be repeated if the user just types return. This is
4848 useful if the command is time-consuming to run, so that accidental
4849 extra keystrokes don't run the same command many times.
4851 * Send break instead of ^C
4853 The standard remote protocol now includes an option to send a break
4854 rather than a ^C to the target in order to interrupt it. By default,
4855 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4857 * Remote protocol timeout
4859 The standard remote protocol includes a new variable `remotetimeout'
4860 that allows you to set the number of seconds before GDB gives up trying
4861 to read from the target. The default value is 2.
4863 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4865 By default GDB will automatically keep track of objects as they are
4866 loaded and unloaded by the dynamic linker. By using the command `set
4867 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4868 when shared library events occur, thus allowing you to set breakpoints
4869 in shared libraries which are explicitly loaded by the inferior.
4871 Note this feature does not work on hpux8. On hpux9 you must link
4872 /usr/lib/end.o into your program. This feature should work
4873 automatically on hpux10.
4875 * Irix 5.x hardware watchpoint support
4877 Irix 5 configurations now support the use of hardware watchpoints.
4879 * Mips protocol "SYN garbage limit"
4881 When debugging a Mips target using the `target mips' protocol, you
4882 may set the number of characters that GDB will ignore by setting
4883 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4884 every character. The default value is 1050.
4886 * Recording and replaying remote debug sessions
4888 If you set `remotelogfile' to the name of a file, gdb will write to it
4889 a recording of a remote debug session. This recording may then be
4890 replayed back to gdb using "gdbreplay". See gdbserver/README for
4891 details. This is useful when you have a problem with GDB while doing
4892 remote debugging; you can make a recording of the session and send it
4893 to someone else, who can then recreate the problem.
4895 * Speedups for remote debugging
4897 GDB includes speedups for downloading and stepping MIPS systems using
4898 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4899 and more efficient S-record downloading.
4901 * Memory use reductions and statistics collection
4903 GDB now uses less memory and reports statistics about memory usage.
4904 Try the `maint print statistics' command, for example.
4906 *** Changes in GDB-4.15:
4908 * Psymtabs for XCOFF
4910 The symbol reader for AIX GDB now uses partial symbol tables. This
4911 can greatly improve startup time, especially for large executables.
4913 * Remote targets use caching
4915 Remote targets now use a data cache to speed up communication with the
4916 remote side. The data cache could lead to incorrect results because
4917 it doesn't know about volatile variables, thus making it impossible to
4918 debug targets which use memory mapped I/O devices. `set remotecache
4919 off' turns the the data cache off.
4921 * Remote targets may have threads
4923 The standard remote protocol now includes support for multiple threads
4924 in the target system, using new protocol commands 'H' and 'T'. See
4925 gdb/remote.c for details.
4929 If GDB is configured with `--enable-netrom', then it will include
4930 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4931 acts as though it is a bank of ROM on the target board, but you can
4932 write into it over the network. GDB's support consists only of
4933 support for fast loading into the emulated ROM; to debug, you must use
4934 another protocol, such as standard remote protocol. The usual
4935 sequence is something like
4937 target nrom <netrom-hostname>
4939 target remote <netrom-hostname>:1235
4943 GDB now includes support for the Apple Macintosh, as a host only. It
4944 may be run as either an MPW tool or as a standalone application, and
4945 it can debug through the serial port. All the usual GDB commands are
4946 available, but to the target command, you must supply "serial" as the
4947 device type instead of "/dev/ttyXX". See mpw-README in the main
4948 directory for more information on how to build. The MPW configuration
4949 scripts */mpw-config.in support only a few targets, and only the
4950 mips-idt-ecoff target has been tested.
4954 GDB configuration now uses autoconf. This is not user-visible,
4955 but does simplify configuration and building.
4959 GDB now supports hpux10.
4961 *** Changes in GDB-4.14:
4963 * New native configurations
4965 x86 FreeBSD i[345]86-*-freebsd
4966 x86 NetBSD i[345]86-*-netbsd
4967 NS32k NetBSD ns32k-*-netbsd
4968 Sparc NetBSD sparc-*-netbsd
4972 A29K VxWorks a29k-*-vxworks
4973 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4974 CPU32 EST-300 emulator m68*-*-est*
4975 PowerPC ELF powerpc-*-elf
4978 * Alpha OSF/1 support for procfs
4980 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4981 possible to attach to running processes. As the mounting of the /proc
4982 filesystem is optional on the Alpha, GDB automatically determines
4983 the availability of /proc during startup. This can lead to problems
4984 if /proc is unmounted after GDB has been started.
4986 * Arguments to user-defined commands
4988 User commands may accept up to 10 arguments separated by whitespace.
4989 Arguments are accessed within the user command via $arg0..$arg9. A
4992 print $arg0 + $arg1 + $arg2
4994 To execute the command use:
4997 Defines the command "adder" which prints the sum of its three arguments.
4998 Note the arguments are text substitutions, so they may reference variables,
4999 use complex expressions, or even perform inferior function calls.
5001 * New `if' and `while' commands
5003 This makes it possible to write more sophisticated user-defined
5004 commands. Both commands take a single argument, which is the
5005 expression to evaluate, and must be followed by the commands to
5006 execute, one per line, if the expression is nonzero, the list being
5007 terminated by the word `end'. The `if' command list may include an
5008 `else' word, which causes the following commands to be executed only
5009 if the expression is zero.
5011 * Fortran source language mode
5013 GDB now includes partial support for Fortran 77. It will recognize
5014 Fortran programs and can evaluate a subset of Fortran expressions, but
5015 variables and functions may not be handled correctly. GDB will work
5016 with G77, but does not yet know much about symbols emitted by other
5019 * Better HPUX support
5021 Most debugging facilities now work on dynamic executables for HPPAs
5022 running hpux9 or later. You can attach to running dynamically linked
5023 processes, but by default the dynamic libraries will be read-only, so
5024 for instance you won't be able to put breakpoints in them. To change
5025 that behavior do the following before running the program:
5031 This will cause the libraries to be mapped private and read-write.
5032 To revert to the normal behavior, do this:
5038 You cannot set breakpoints or examine data in the library until after
5039 the library is loaded if the function/data symbols do not have
5042 GDB can now also read debug symbols produced by the HP C compiler on
5043 HPPAs (sorry, no C++, Fortran or 68k support).
5045 * Target byte order now dynamically selectable
5047 You can choose which byte order to use with a target system, via the
5048 commands "set endian big" and "set endian little", and you can see the
5049 current setting by using "show endian". You can also give the command
5050 "set endian auto", in which case GDB will use the byte order
5051 associated with the executable. Currently, only embedded MIPS
5052 configurations support dynamic selection of target byte order.
5054 * New DOS host serial code
5056 This version uses DPMI interrupts to handle buffered I/O, so you
5057 no longer need to run asynctsr when debugging boards connected to
5060 *** Changes in GDB-4.13:
5062 * New "complete" command
5064 This lists all the possible completions for the rest of the line, if it
5065 were to be given as a command itself. This is intended for use by emacs.
5067 * Trailing space optional in prompt
5069 "set prompt" no longer adds a space for you after the prompt you set. This
5070 allows you to set a prompt which ends in a space or one that does not.
5072 * Breakpoint hit counts
5074 "info break" now displays a count of the number of times the breakpoint
5075 has been hit. This is especially useful in conjunction with "ignore"; you
5076 can ignore a large number of breakpoint hits, look at the breakpoint info
5077 to see how many times the breakpoint was hit, then run again, ignoring one
5078 less than that number, and this will get you quickly to the last hit of
5081 * Ability to stop printing at NULL character
5083 "set print null-stop" will cause GDB to stop printing the characters of
5084 an array when the first NULL is encountered. This is useful when large
5085 arrays actually contain only short strings.
5087 * Shared library breakpoints
5089 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5090 breakpoints in shared libraries before the executable is run.
5092 * Hardware watchpoints
5094 There is a new hardware breakpoint for the watch command for sparclite
5095 targets. See gdb/sparclite/hw_breakpoint.note.
5097 Hardware watchpoints are also now supported under GNU/Linux.
5101 Annotations have been added. These are for use with graphical interfaces,
5102 and are still experimental. Currently only gdba.el uses these.
5104 * Improved Irix 5 support
5106 GDB now works properly with Irix 5.2.
5108 * Improved HPPA support
5110 GDB now works properly with the latest GCC and GAS.
5112 * New native configurations
5114 Sequent PTX4 i[34]86-sequent-ptx4
5115 HPPA running OSF/1 hppa*-*-osf*
5116 Atari TT running SVR4 m68*-*-sysv4*
5117 RS/6000 LynxOS rs6000-*-lynxos*
5121 OS/9000 i[34]86-*-os9k
5122 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5125 * Hitachi SH7000 and E7000-PC ICE support
5127 There is now support for communicating with the Hitachi E7000-PC ICE.
5128 This is available automatically when GDB is configured for the SH.
5132 As usual, a variety of small fixes and improvements, both generic
5133 and configuration-specific. See the ChangeLog for more detail.
5135 *** Changes in GDB-4.12:
5137 * Irix 5 is now supported
5141 GDB-4.12 on the HPPA has a number of changes which make it unable
5142 to debug the output from the currently released versions of GCC and
5143 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5144 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5145 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5148 *** Changes in GDB-4.11:
5150 * User visible changes:
5154 The "set remotedebug" option is now consistent between the mips remote
5155 target, remote targets using the gdb-specific protocol, UDI (AMD's
5156 debug protocol for the 29k) and the 88k bug monitor. It is now an
5157 integer specifying a debug level (normally 0 or 1, but 2 means more
5158 debugging info for the mips target).
5160 * DEC Alpha native support
5162 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5163 debug info, but GDB works fairly well with the DEC compiler and should
5164 work with a future GCC release. See the README file for a few
5165 Alpha-specific notes.
5167 * Preliminary thread implementation
5169 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5171 * LynxOS native and target support for 386
5173 This release has been hosted on LynxOS 2.2, and also can be configured
5174 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5177 * Improvements in C++ mangling/demangling.
5179 This release has much better g++ debugging, specifically in name
5180 mangling/demangling, virtual function calls, print virtual table,
5181 call methods, ...etc.
5183 *** Changes in GDB-4.10:
5185 * User visible changes:
5187 Remote debugging using the GDB-specific (`target remote') protocol now
5188 supports the `load' command. This is only useful if you have some
5189 other way of getting the stub to the target system, and you can put it
5190 somewhere in memory where it won't get clobbered by the download.
5192 Filename completion now works.
5194 When run under emacs mode, the "info line" command now causes the
5195 arrow to point to the line specified. Also, "info line" prints
5196 addresses in symbolic form (as well as hex).
5198 All vxworks based targets now support a user settable option, called
5199 vxworks-timeout. This option represents the number of seconds gdb
5200 should wait for responses to rpc's. You might want to use this if
5201 your vxworks target is, perhaps, a slow software simulator or happens
5202 to be on the far side of a thin network line.
5206 This release contains support for using a DEC alpha as a GDB host for
5207 cross debugging. Native alpha debugging is not supported yet.
5210 *** Changes in GDB-4.9:
5214 This is the first GDB release which is accompanied by a matching testsuite.
5215 The testsuite requires installation of dejagnu, which should be available
5216 via ftp from most sites that carry GNU software.
5220 'Cfront' style demangling has had its name changed to 'ARM' style, to
5221 emphasize that it was written from the specifications in the C++ Annotated
5222 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5223 disclaimers, it still generated too much confusion with users attempting to
5224 use gdb with AT&T cfront.
5228 GDB now uses a standard remote interface to a simulator library.
5229 So far, the library contains simulators for the Zilog Z8001/2, the
5230 Hitachi H8/300, H8/500 and Super-H.
5232 * New targets supported
5234 H8/300 simulator h8300-hitachi-hms or h8300hms
5235 H8/500 simulator h8500-hitachi-hms or h8500hms
5236 SH simulator sh-hitachi-hms or sh
5237 Z8000 simulator z8k-zilog-none or z8ksim
5238 IDT MIPS board over serial line mips-idt-ecoff
5240 Cross-debugging to GO32 targets is supported. It requires a custom
5241 version of the i386-stub.c module which is integrated with the
5242 GO32 memory extender.
5244 * New remote protocols
5246 MIPS remote debugging protocol.
5248 * New source languages supported
5250 This version includes preliminary support for Chill, a Pascal like language
5251 used by telecommunications companies. Chill support is also being integrated
5252 into the GNU compiler, but we don't know when it will be publically available.
5255 *** Changes in GDB-4.8:
5257 * HP Precision Architecture supported
5259 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5260 version of this support was available as a set of patches from the
5261 University of Utah. GDB does not support debugging of programs
5262 compiled with the HP compiler, because HP will not document their file
5263 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5264 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5266 Many problems in the preliminary version have been fixed.
5268 * Faster and better demangling
5270 We have improved template demangling and fixed numerous bugs in the GNU style
5271 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5272 character types (wchar_t) are now supported. Demangling of each symbol is now
5273 only done once, and is cached when the symbol table for a file is read in.
5274 This results in a small increase in memory usage for C programs, a moderate
5275 increase in memory usage for C++ programs, and a fantastic speedup in
5278 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5279 from the specifications in the Annotated Reference Manual, which AT&T's
5280 compiler does not actually implement.
5282 * G++ multiple inheritance compiler problem
5284 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5285 inheritance lattices was reworked to properly discover ambiguities. We
5286 recently found an example which causes this new algorithm to fail in a
5287 very subtle way, producing bad debug information for those classes.
5288 The file 'gcc.patch' (in this directory) can be applied to gcc to
5289 circumvent the problem. A future GCC release will contain a complete
5292 The previous G++ debug info problem (mentioned below for the gdb-4.7
5293 release) is fixed in gcc version 2.3.2.
5295 * Improved configure script
5297 The `configure' script will now attempt to guess your system type if
5298 you don't supply a host system type. The old scheme of supplying a
5299 host system triplet is preferable over using this. All the magic is
5300 done in the new `config.guess' script. Examine it for details.
5302 We have also brought our configure script much more in line with the FSF's
5303 version. It now supports the --with-xxx options. In particular,
5304 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5305 The resulting GDB will not be able to read arbitrary object file formats --
5306 only the format ``expected'' to be used on the configured target system.
5307 We hope to make this the default in a future release.
5309 * Documentation improvements
5311 There's new internal documentation on how to modify GDB, and how to
5312 produce clean changes to the code. We implore people to read it
5313 before submitting changes.
5315 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5316 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5317 `info' files are also provided. To build `info' files from scratch,
5318 you will need the latest `makeinfo' release, which will be available in
5319 a future texinfo-X.Y release.
5321 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5322 We're not sure exactly which versions have this problem, but it has
5323 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5324 or better. If that isn't possible, there is a patch in
5325 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5326 around this problem.
5330 GDB now supports array constants that can be used in expressions typed in by
5331 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5332 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5335 The new directory `gdb/sparclite' contains a program that demonstrates
5336 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5338 * New native hosts supported
5340 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5341 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5343 * New targets supported
5345 AMD 29k family via UDI a29k-amd-udi or udi29k
5347 * New file formats supported
5349 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5350 HPUX core files, and SCO 3.2v2 core files.
5354 Attaching to processes now works again; thanks for the many bug reports.
5356 We have also stomped on a bunch of core dumps caused by
5357 printf_filtered("%s") problems.
5359 We eliminated a copyright problem on the rpc and ptrace header files
5360 for VxWorks, which was discovered at the last minute during the 4.7
5361 release. You should now be able to build a VxWorks GDB.
5363 You can now interrupt gdb while an attached process is running. This
5364 will cause the attached process to stop, and give control back to GDB.
5366 We fixed problems caused by using too many file descriptors
5367 for reading symbols from object files and libraries. This was
5368 especially a problem for programs that used many (~100) shared
5371 The `step' command now only enters a subroutine if there is line number
5372 information for the subroutine. Otherwise it acts like the `next'
5373 command. Previously, `step' would enter subroutines if there was
5374 any debugging information about the routine. This avoids problems
5375 when using `cc -g1' on MIPS machines.
5377 * Internal improvements
5379 GDB's internal interfaces have been improved to make it easier to support
5380 debugging of multiple languages in the future.
5382 GDB now uses a common structure for symbol information internally.
5383 Minimal symbols (derived from linkage symbols in object files), partial
5384 symbols (from a quick scan of debug information), and full symbols
5385 contain a common subset of information, making it easier to write
5386 shared code that handles any of them.
5388 * New command line options
5390 We now accept --silent as an alias for --quiet.
5394 The memory-mapped-malloc library is now licensed under the GNU Library
5395 General Public License.
5397 *** Changes in GDB-4.7:
5399 * Host/native/target split
5401 GDB has had some major internal surgery to untangle the support for
5402 hosts and remote targets. Now, when you configure GDB for a remote
5403 target, it will no longer load in all of the support for debugging
5404 local programs on the host. When fully completed and tested, this will
5405 ensure that arbitrary host/target combinations are possible.
5407 The primary conceptual shift is to separate the non-portable code in
5408 GDB into three categories. Host specific code is required any time GDB
5409 is compiled on that host, regardless of the target. Target specific
5410 code relates to the peculiarities of the target, but can be compiled on
5411 any host. Native specific code is everything else: it can only be
5412 built when the host and target are the same system. Child process
5413 handling and core file support are two common `native' examples.
5415 GDB's use of /proc for controlling Unix child processes is now cleaner.
5416 It has been split out into a single module under the `target_ops' vector,
5417 plus two native-dependent functions for each system that uses /proc.
5419 * New hosts supported
5421 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5422 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5423 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5425 * New targets supported
5427 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5428 68030 and CPU32 m68030-*-*, m68332-*-*
5430 * New native hosts supported
5432 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5433 (386bsd is not well tested yet)
5434 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5436 * New file formats supported
5438 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5439 supports reading of `a.out.adobe' object files, which are an a.out
5440 format extended with minimal information about multiple sections.
5444 `show copying' is the same as the old `info copying'.
5445 `show warranty' is the same as `info warrantee'.
5446 These were renamed for consistency. The old commands continue to work.
5448 `info handle' is a new alias for `info signals'.
5450 You can now define pre-command hooks, which attach arbitrary command
5451 scripts to any command. The commands in the hook will be executed
5452 prior to the user's command. You can also create a hook which will be
5453 executed whenever the program stops. See gdb.texinfo.
5457 We now deal with Cfront style name mangling, and can even extract type
5458 info from mangled symbols. GDB can automatically figure out which
5459 symbol mangling style your C++ compiler uses.
5461 Calling of methods and virtual functions has been improved as well.
5465 The crash that occured when debugging Sun Ansi-C compiled binaries is
5466 fixed. This was due to mishandling of the extra N_SO stabs output
5469 We also finally got Ultrix 4.2 running in house, and fixed core file
5470 support, with help from a dozen people on the net.
5472 John M. Farrell discovered that the reason that single-stepping was so
5473 slow on all of the Mips based platforms (primarily SGI and DEC) was
5474 that we were trying to demangle and lookup a symbol used for internal
5475 purposes on every instruction that was being stepped through. Changing
5476 the name of that symbol so that it couldn't be mistaken for a C++
5477 mangled symbol sped things up a great deal.
5479 Rich Pixley sped up symbol lookups in general by getting much smarter
5480 about when C++ symbol mangling is necessary. This should make symbol
5481 completion (TAB on the command line) much faster. It's not as fast as
5482 we'd like, but it's significantly faster than gdb-4.6.
5486 A new user controllable variable 'call_scratch_address' can
5487 specify the location of a scratch area to be used when GDB
5488 calls a function in the target. This is necessary because the
5489 usual method of putting the scratch area on the stack does not work
5490 in systems that have separate instruction and data spaces.
5492 We integrated changes to support the 29k UDI (Universal Debugger
5493 Interface), but discovered at the last minute that we didn't have all
5494 of the appropriate copyright paperwork. We are working with AMD to
5495 resolve this, and hope to have it available soon.
5499 We have sped up the remote serial line protocol, especially for targets
5500 with lots of registers. It now supports a new `expedited status' ('T')
5501 message which can be used in place of the existing 'S' status message.
5502 This allows the remote stub to send only the registers that GDB
5503 needs to make a quick decision about single-stepping or conditional
5504 breakpoints, eliminating the need to fetch the entire register set for
5505 each instruction being stepped through.
5507 The GDB remote serial protocol now implements a write-through cache for
5508 registers, only re-reading the registers if the target has run.
5510 There is also a new remote serial stub for SPARC processors. You can
5511 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5512 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5513 processor with a serial port.
5517 Configure.in files have become much easier to read and modify. A new
5518 `table driven' format makes it more obvious what configurations are
5519 supported, and what files each one uses.
5523 There is a new opcodes library which will eventually contain all of the
5524 disassembly routines and opcode tables. At present, it only contains
5525 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5526 disassembler (binutils/objdump) to share these routines.
5528 The libiberty library is now copylefted under the GNU Library General
5529 Public License. This allows more liberal use, and was done so libg++
5530 can use it. This makes no difference to GDB, since the Library License
5531 grants all the rights from the General Public License.
5535 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5536 reference to the stabs symbol info used by the debugger. It is (as far
5537 as we know) the only published document on this fascinating topic. We
5538 encourage you to read it, compare it to the stabs information on your
5539 system, and send improvements on the document in general (to
5540 bug-gdb@prep.ai.mit.edu).
5542 And, of course, many bugs have been fixed.
5545 *** Changes in GDB-4.6:
5547 * Better support for C++ function names
5549 GDB now accepts as input the "demangled form" of C++ overloaded function
5550 names and member function names, and can do command completion on such names
5551 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5552 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5553 Make use of command completion, it is your friend.
5555 GDB also now accepts a variety of C++ mangled symbol formats. They are
5556 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5557 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5558 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5559 for the list of formats.
5561 * G++ symbol mangling problem
5563 Recent versions of gcc have a bug in how they emit debugging information for
5564 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5565 directory) can be applied to gcc to fix the problem. Alternatively, if you
5566 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5567 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5568 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5571 * New 'maintenance' command
5573 All of the commands related to hacking GDB internals have been moved out of
5574 the main command set, and now live behind the 'maintenance' command. This
5575 can also be abbreviated as 'mt'. The following changes were made:
5577 dump-me -> maintenance dump-me
5578 info all-breakpoints -> maintenance info breakpoints
5579 printmsyms -> maintenance print msyms
5580 printobjfiles -> maintenance print objfiles
5581 printpsyms -> maintenance print psymbols
5582 printsyms -> maintenance print symbols
5584 The following commands are new:
5586 maintenance demangle Call internal GDB demangler routine to
5587 demangle a C++ link name and prints the result.
5588 maintenance print type Print a type chain for a given symbol
5590 * Change to .gdbinit file processing
5592 We now read the $HOME/.gdbinit file before processing the argv arguments
5593 (e.g. reading symbol files or core files). This allows global parameters to
5594 be set, which will apply during the symbol reading. The ./.gdbinit is still
5595 read after argv processing.
5597 * New hosts supported
5599 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5601 GNU/Linux support i386-unknown-linux or linux
5603 We are also including code to support the HP/PA running BSD and HPUX. This
5604 is almost guaranteed not to work, as we didn't have time to test or build it
5605 for this release. We are including it so that the more adventurous (or
5606 masochistic) of you can play with it. We also had major problems with the
5607 fact that the compiler that we got from HP doesn't support the -g option.
5610 * New targets supported
5612 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5614 * More smarts about finding #include files
5616 GDB now remembers the compilation directory for all include files, and for
5617 all files from which C is generated (like yacc and lex sources). This
5618 greatly improves GDB's ability to find yacc/lex sources, and include files,
5619 especially if you are debugging your program from a directory different from
5620 the one that contains your sources.
5622 We also fixed a bug which caused difficulty with listing and setting
5623 breakpoints in include files which contain C code. (In the past, you had to
5624 try twice in order to list an include file that you hadn't looked at before.)
5626 * Interesting infernals change
5628 GDB now deals with arbitrary numbers of sections, where the symbols for each
5629 section must be relocated relative to that section's landing place in the
5630 target's address space. This work was needed to support ELF with embedded
5631 stabs used by Solaris-2.0.
5633 * Bug fixes (of course!)
5635 There have been loads of fixes for the following things:
5636 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5637 i960, stabs, DOS(GO32), procfs, etc...
5639 See the ChangeLog for details.
5641 *** Changes in GDB-4.5:
5643 * New machines supported (host and target)
5645 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5647 SGI Irix-4.x mips-sgi-irix4 or iris4
5649 * New malloc package
5651 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5652 Mmalloc is capable of handling mutiple heaps of memory. It is also
5653 capable of saving a heap to a file, and then mapping it back in later.
5654 This can be used to greatly speedup the startup of GDB by using a
5655 pre-parsed symbol table which lives in a mmalloc managed heap. For
5656 more details, please read mmalloc/mmalloc.texi.
5660 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5661 'help info proc' for details.
5663 * MIPS ecoff symbol table format
5665 The code that reads MIPS symbol table format is now supported on all hosts.
5666 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5669 * File name changes for MS-DOS
5671 Many files in the config directories have been renamed to make it easier to
5672 support GDB on MS-DOSe systems (which have very restrictive file name
5673 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5674 environment) is close to working but has some remaining problems. Note
5675 that debugging of DOS programs is not supported, due to limitations
5676 in the ``operating system'', but it can be used to host cross-debugging.
5678 * Cross byte order fixes
5680 Many fixes have been made to support cross debugging of Sparc and MIPS
5681 targets from hosts whose byte order differs.
5683 * New -mapped and -readnow options
5685 If memory-mapped files are available on your system through the 'mmap'
5686 system call, you can use the -mapped option on the `file' or
5687 `symbol-file' commands to cause GDB to write the symbols from your
5688 program into a reusable file. If the program you are debugging is
5689 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5690 Future GDB debugging sessions will notice the presence of this file,
5691 and will quickly map in symbol information from it, rather than reading
5692 the symbol table from the executable program. Using the '-mapped'
5693 option in a GDB `file' or `symbol-file' command has the same effect as
5694 starting GDB with the '-mapped' command-line option.
5696 You can cause GDB to read the entire symbol table immediately by using
5697 the '-readnow' option with any of the commands that load symbol table
5698 information (or on the GDB command line). This makes the command
5699 slower, but makes future operations faster.
5701 The -mapped and -readnow options are typically combined in order to
5702 build a `fred.syms' file that contains complete symbol information.
5703 A simple GDB invocation to do nothing but build a `.syms' file for future
5706 gdb -batch -nx -mapped -readnow programname
5708 The `.syms' file is specific to the host machine on which GDB is run.
5709 It holds an exact image of GDB's internal symbol table. It cannot be
5710 shared across multiple host platforms.
5712 * longjmp() handling
5714 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5715 siglongjmp() without losing control. This feature has not yet been ported to
5716 all systems. It currently works on many 386 platforms, all MIPS-based
5717 platforms (SGI, DECstation, etc), and Sun3/4.
5721 Preliminary work has been put in to support the new Solaris OS from Sun. At
5722 this time, it can control and debug processes, but it is not capable of
5727 As always, many many bug fixes. The major areas were with g++, and mipsread.
5728 People using the MIPS-based platforms should experience fewer mysterious
5729 crashes and trashed symbol tables.
5731 *** Changes in GDB-4.4:
5733 * New machines supported (host and target)
5735 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5737 BSD Reno on Vax vax-dec-bsd
5738 Ultrix on Vax vax-dec-ultrix
5740 * New machines supported (target)
5742 AMD 29000 embedded, using EBMON a29k-none-none
5746 GDB continues to improve its handling of C++. `References' work better.
5747 The demangler has also been improved, and now deals with symbols mangled as
5748 per the Annotated C++ Reference Guide.
5750 GDB also now handles `stabs' symbol information embedded in MIPS
5751 `ecoff' symbol tables. Since the ecoff format was not easily
5752 extensible to handle new languages such as C++, this appeared to be a
5753 good way to put C++ debugging info into MIPS binaries. This option
5754 will be supported in the GNU C compiler, version 2, when it is
5757 * New features for SVR4
5759 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5760 shared libraries. Debugging dynamically linked programs should present
5761 only minor differences from debugging statically linked programs.
5763 The `info proc' command will print out information about any process
5764 on an SVR4 system (including the one you are debugging). At the moment,
5765 it prints the address mappings of the process.
5767 If you bring up GDB on another SVR4 system, please send mail to
5768 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5770 * Better dynamic linking support in SunOS
5772 Reading symbols from shared libraries which contain debugging symbols
5773 now works properly. However, there remain issues such as automatic
5774 skipping of `transfer vector' code during function calls, which
5775 make it harder to debug code in a shared library, than to debug the
5776 same code linked statically.
5780 GDB is now using the latest `getopt' routines from the FSF. This
5781 version accepts the -- prefix for options with long names. GDB will
5782 continue to accept the old forms (-option and +option) as well.
5783 Various single letter abbreviations for options have been explicity
5784 added to the option table so that they won't get overshadowed in the
5785 future by other options that begin with the same letter.
5789 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5790 Many assorted bugs have been handled. Many more remain to be handled.
5791 See the various ChangeLog files (primarily in gdb and bfd) for details.
5794 *** Changes in GDB-4.3:
5796 * New machines supported (host and target)
5798 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5799 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5800 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5802 * Almost SCO Unix support
5804 We had hoped to support:
5805 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5806 (except for core file support), but we discovered very late in the release
5807 that it has problems with process groups that render gdb unusable. Sorry
5808 about that. I encourage people to fix it and post the fixes.
5810 * Preliminary ELF and DWARF support
5812 GDB can read ELF object files on System V Release 4, and can handle
5813 debugging records for C, in DWARF format, in ELF files. This support
5814 is preliminary. If you bring up GDB on another SVR4 system, please
5815 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5820 GDB now uses the latest `readline' library. One user-visible change
5821 is that two tabs will list possible command completions, which previously
5822 required typing M-? (meta-question mark, or ESC ?).
5826 The `stepi' bug that many of you noticed has been squashed.
5827 Many bugs in C++ have been handled. Many more remain to be handled.
5828 See the various ChangeLog files (primarily in gdb and bfd) for details.
5830 * State of the MIPS world (in case you wondered):
5832 GDB can understand the symbol tables emitted by the compilers
5833 supplied by most vendors of MIPS-based machines, including DEC. These
5834 symbol tables are in a format that essentially nobody else uses.
5836 Some versions of gcc come with an assembler post-processor called
5837 mips-tfile. This program is required if you want to do source-level
5838 debugging of gcc-compiled programs. I believe FSF does not ship
5839 mips-tfile with gcc version 1, but it will eventually come with gcc
5842 Debugging of g++ output remains a problem. g++ version 1.xx does not
5843 really support it at all. (If you're lucky, you should be able to get
5844 line numbers and stack traces to work, but no parameters or local
5845 variables.) With some work it should be possible to improve the
5848 When gcc version 2 is released, you will have somewhat better luck.
5849 However, even then you will get confusing results for inheritance and
5852 We will eventually provide full debugging of g++ output on
5853 DECstations. This will probably involve some kind of stabs-in-ecoff
5854 encapulation, but the details have not been worked out yet.
5857 *** Changes in GDB-4.2:
5859 * Improved configuration
5861 Only one copy of `configure' exists now, and it is not self-modifying.
5862 Porting BFD is simpler.
5866 The `step' and `next' commands now only stop at the first instruction
5867 of a source line. This prevents the multiple stops that used to occur
5868 in switch statements, for-loops, etc. `Step' continues to stop if a
5869 function that has debugging information is called within the line.
5873 Lots of small bugs fixed. More remain.
5875 * New host supported (not target)
5877 Intel 386 PC clone running Mach i386-none-mach
5880 *** Changes in GDB-4.1:
5882 * Multiple source language support
5884 GDB now has internal scaffolding to handle several source languages.
5885 It determines the type of each source file from its filename extension,
5886 and will switch expression parsing and number formatting to match the
5887 language of the function in the currently selected stack frame.
5888 You can also specifically set the language to be used, with
5889 `set language c' or `set language modula-2'.
5893 GDB now has preliminary support for the GNU Modula-2 compiler,
5894 currently under development at the State University of New York at
5895 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5896 continue through the fall of 1991 and into 1992.
5898 Other Modula-2 compilers are currently not supported, and attempting to
5899 debug programs compiled with them will likely result in an error as the
5900 symbol table is read. Feel free to work on it, though!
5902 There are hooks in GDB for strict type checking and range checking,
5903 in the `Modula-2 philosophy', but they do not currently work.
5907 GDB can now write to executable and core files (e.g. patch
5908 a variable's value). You must turn this switch on, specify
5909 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5910 by assigning a new value to a variable. Modifications take
5913 * Automatic SunOS shared library reading
5915 When you run your program, GDB automatically determines where its
5916 shared libraries (if any) have been loaded, and reads their symbols.
5917 The `share' command is no longer needed. This also works when
5918 examining core files.
5922 You can specify the number of lines that the `list' command shows.
5925 * New machines supported (host and target)
5927 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5928 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5929 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5931 * New hosts supported (not targets)
5933 IBM RT/PC: romp-ibm-aix or rtpc
5935 * New targets supported (not hosts)
5937 AMD 29000 embedded with COFF a29k-none-coff
5938 AMD 29000 embedded with a.out a29k-none-aout
5939 Ultracomputer remote kernel debug a29k-nyu-kern
5941 * New remote interfaces
5947 *** Changes in GDB-4.0:
5951 Wide output is wrapped at good places to make the output more readable.
5953 Gdb now supports cross-debugging from a host machine of one type to a
5954 target machine of another type. Communication with the target system
5955 is over serial lines. The ``target'' command handles connecting to the
5956 remote system; the ``load'' command will download a program into the
5957 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5958 also supports debugging of realtime processes running under VxWorks,
5959 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5960 stub on the target system.
5962 New CPUs supported include the AMD 29000 and Intel 960.
5964 GDB now reads object files and symbol tables via a ``binary file''
5965 library, which allows a single copy of GDB to debug programs of multiple
5966 object file types such as a.out and coff.
5968 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5969 refcard.dvi and refcard.ps are available to format it).
5972 * Control-Variable user interface simplified
5974 All variables that control the operation of the debugger can be set
5975 by the ``set'' command, and displayed by the ``show'' command.
5977 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5978 ``Show prompt'' produces the response:
5979 Gdb's prompt is new-gdb=>.
5981 What follows are the NEW set commands. The command ``help set'' will
5982 print a complete list of old and new set commands. ``help set FOO''
5983 will give a longer description of the variable FOO. ``show'' will show
5984 all of the variable descriptions and their current settings.
5986 confirm on/off: Enables warning questions for operations that are
5987 hard to recover from, e.g. rerunning the program while
5988 it is already running. Default is ON.
5990 editing on/off: Enables EMACS style command line editing
5991 of input. Previous lines can be recalled with
5992 control-P, the current line can be edited with control-B,
5993 you can search for commands with control-R, etc.
5996 history filename NAME: NAME is where the gdb command history
5997 will be stored. The default is .gdb_history,
5998 or the value of the environment variable
6001 history size N: The size, in commands, of the command history. The
6002 default is 256, or the value of the environment variable
6005 history save on/off: If this value is set to ON, the history file will
6006 be saved after exiting gdb. If set to OFF, the
6007 file will not be saved. The default is OFF.
6009 history expansion on/off: If this value is set to ON, then csh-like
6010 history expansion will be performed on
6011 command line input. The default is OFF.
6013 radix N: Sets the default radix for input and output. It can be set
6014 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6015 in the current radix, so "set radix 10" is always a no-op.
6017 height N: This integer value is the number of lines on a page. Default
6018 is 24, the current `stty rows'' setting, or the ``li#''
6019 setting from the termcap entry matching the environment
6022 width N: This integer value is the number of characters on a line.
6023 Default is 80, the current `stty cols'' setting, or the ``co#''
6024 setting from the termcap entry matching the environment
6027 Note: ``set screensize'' is obsolete. Use ``set height'' and
6028 ``set width'' instead.
6030 print address on/off: Print memory addresses in various command displays,
6031 such as stack traces and structure values. Gdb looks
6032 more ``symbolic'' if you turn this off; it looks more
6033 ``machine level'' with it on. Default is ON.
6035 print array on/off: Prettyprint arrays. New convenient format! Default
6038 print demangle on/off: Print C++ symbols in "source" form if on,
6041 print asm-demangle on/off: Same, for assembler level printouts
6044 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6047 * Support for Epoch Environment.
6049 The epoch environment is a version of Emacs v18 with windowing. One
6050 new command, ``inspect'', is identical to ``print'', except that if you
6051 are running in the epoch environment, the value is printed in its own
6055 * Support for Shared Libraries
6057 GDB can now debug programs and core files that use SunOS shared libraries.
6058 Symbols from a shared library cannot be referenced
6059 before the shared library has been linked with the program (this
6060 happens after you type ``run'' and before the function main() is entered).
6061 At any time after this linking (including when examining core files
6062 from dynamically linked programs), gdb reads the symbols from each
6063 shared library when you type the ``sharedlibrary'' command.
6064 It can be abbreviated ``share''.
6066 sharedlibrary REGEXP: Load shared object library symbols for files
6067 matching a unix regular expression. No argument
6068 indicates to load symbols for all shared libraries.
6070 info sharedlibrary: Status of loaded shared libraries.
6075 A watchpoint stops execution of a program whenever the value of an
6076 expression changes. Checking for this slows down execution
6077 tremendously whenever you are in the scope of the expression, but is
6078 quite useful for catching tough ``bit-spreader'' or pointer misuse
6079 problems. Some machines such as the 386 have hardware for doing this
6080 more quickly, and future versions of gdb will use this hardware.
6082 watch EXP: Set a watchpoint (breakpoint) for an expression.
6084 info watchpoints: Information about your watchpoints.
6086 delete N: Deletes watchpoint number N (same as breakpoints).
6087 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6088 enable N: Re-enables watchpoint number N (same as breakpoints).
6091 * C++ multiple inheritance
6093 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6096 * C++ exception handling
6098 Gdb now supports limited C++ exception handling. Besides the existing
6099 ability to breakpoint on an exception handler, gdb can breakpoint on
6100 the raising of an exception (before the stack is peeled back to the
6103 catch FOO: If there is a FOO exception handler in the dynamic scope,
6104 set a breakpoint to catch exceptions which may be raised there.
6105 Multiple exceptions (``catch foo bar baz'') may be caught.
6107 info catch: Lists all exceptions which may be caught in the
6108 current stack frame.
6111 * Minor command changes
6113 The command ``call func (arg, arg, ...)'' now acts like the print
6114 command, except it does not print or save a value if the function's result
6115 is void. This is similar to dbx usage.
6117 The ``up'' and ``down'' commands now always print the frame they end up
6118 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6119 frames without printing.
6121 * New directory command
6123 'dir' now adds directories to the FRONT of the source search path.
6124 The path starts off empty. Source files that contain debug information
6125 about the directory in which they were compiled can be found even
6126 with an empty path; Sun CC and GCC include this information. If GDB can't
6127 find your source file in the current directory, type "dir .".
6129 * Configuring GDB for compilation
6131 For normal use, type ``./configure host''. See README or gdb.texinfo
6134 GDB now handles cross debugging. If you are remotely debugging between
6135 two different machines, type ``./configure host -target=targ''.
6136 Host is the machine where GDB will run; targ is the machine
6137 where the program that you are debugging will run.