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.
64 ** Memory ports can now be unbuffered.
68 ** gdb.Objfile objects have a new attribute "username",
69 which is the name of the objfile as specified by the user,
70 without, for example, resolving symlinks.
71 ** You can now write frame unwinders in Python.
72 ** gdb.Type objects have a new method "optimized_out",
73 returning optimized out gdb.Value instance of this type.
74 ** gdb.Value objects have new methods "reference_value" and
75 "const_value" which return a reference to the value and a
76 "const" version of the value respectively.
80 maint print symbol-cache
81 Print the contents of the symbol cache.
83 maint print symbol-cache-statistics
84 Print statistics of symbol cache usage.
86 maint flush-symbol-cache
87 Flush the contents of the symbol cache.
91 Start branch trace recording using Branch Trace Store (BTS) format.
94 Evaluate expression by using the compiler and print result.
98 Explicit commands for enabling and disabling tui mode.
101 set mpx bound on i386 and amd64
102 Support for bound table investigation on Intel(R) MPX enabled applications.
107 Renamed from "set debug dwarf2-die".
109 Renamed from "show debug dwarf2-die".
112 Renamed from "set debug dwarf2-read".
113 show debug dwarf-read
114 Renamed from "show debug dwarf2-read".
116 maint set dwarf always-disassemble
117 Renamed from "maint set dwarf2 always-disassemble".
118 maint show dwarf always-disassemble
119 Renamed from "maint show dwarf2 always-disassemble".
121 maint set dwarf max-cache-age
122 Renamed from "maint set dwarf2 max-cache-age".
123 maint show dwarf max-cache-age
124 Renamed from "maint show dwarf2 max-cache-age".
127 show debug dwarf-line
128 Control display of debugging info regarding DWARF line processing.
132 Set the maximum number of candidates to be considered during
133 completion. The default value is 200. This limit allows GDB
134 to avoid generating large completion lists, the computation of
135 which can cause the debugger to become temporarily unresponsive.
137 maint set symbol-cache-size
138 maint show symbol-cache-size
139 Control the size of the symbol cache.
141 set|show record btrace bts buffer-size
142 Set and show the size of the ring buffer used for branch tracing in
144 The obtained size may differ from the requested size. Use "info
145 record" to see the obtained buffer size.
147 set debug linux-namespaces
148 show debug linux-namespaces
149 Control display of debugging info regarding Linux namespaces.
151 * The command 'thread apply all' can now support new option '-ascending'
152 to call its specified command for all threads in ascending order.
154 * Python/Guile scripting
156 ** GDB now supports auto-loading of Python/Guile scripts contained in the
157 special section named `.debug_gdb_scripts'.
161 qXfer:btrace-conf:read
162 Return the branch trace configuration for the current thread.
164 Qbtrace-conf:bts:size
165 Set the requested ring buffer size for branch tracing in BTS format.
168 Indicates a memory breakpoint instruction was executed, irrespective
169 of whether it was GDB that planted the breakpoint or the breakpoint
170 is hardcoded in the program. This is required for correct non-stop
174 Indicates the target stopped for a hardware breakpoint. This is
175 required for correct non-stop mode operation.
178 Return information about files on the remote system.
181 Return the full absolute name of the file that was executed to
182 create a process running on the remote system.
185 Select the filesystem on which vFile: operations with filename
186 arguments will operate. This is required for GDB to be able to
187 access files on remote targets where the remote stub does not
188 share a common filesystem with the inferior(s).
191 Indicates that a fork system call was executed.
194 Indicates that a vfork system call was executed.
196 vforkdone stop reason
197 Indicates that a vfork child of the specified process has executed
198 an exec or exit, allowing the vfork parent to resume execution.
200 fork-events and vfork-events features in qSupported
201 The qSupported packet allows GDB to request support for fork and
202 vfork events using new 'gdbfeatures' fork-events and vfork-events,
203 and the qSupported response can contain the corresponding
204 'stubfeatures'. Set and show commands can be used to display
205 whether these features are enabled.
207 * Extended-remote fork events
209 ** GDB now has support for fork events on extended-remote Linux
210 targets. For targets with Linux kernels 2.5.60 and later, this
211 enables follow-fork-mode and detach-on-fork for both fork and
212 vfork, as well as fork and vfork catchpoints.
214 * The info record command now shows the recording format and the
215 branch tracing configuration for the current thread when using
216 the btrace record target.
217 For the BTS format, it shows the ring buffer size.
219 * GDB now has support for DTrace USDT (Userland Static Defined
220 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
222 * GDB now supports access to vector registers on S/390 GNU/Linux
225 * Removed command line options
227 -xdb HP-UX XDB compatibility mode.
229 * Removed targets and native configurations
231 HP/PA running HP-UX hppa*-*-hpux*
232 Itanium running HP-UX ia64-*-hpux*
234 *** Changes in GDB 7.9.1
238 ** Xmethods can now specify a result type.
240 *** Changes in GDB 7.9
242 * GDB now supports hardware watchpoints on x86 GNU Hurd.
246 ** You can now access frame registers from Python scripts.
247 ** New attribute 'producer' for gdb.Symtab objects.
248 ** gdb.Objfile objects have a new attribute "progspace",
249 which is the gdb.Progspace object of the containing program space.
250 ** gdb.Objfile objects have a new attribute "owner".
251 ** gdb.Objfile objects have a new attribute "build_id",
252 which is the build ID generated when the file was built.
253 ** gdb.Objfile objects have a new method "add_separate_debug_file".
254 ** A new event "gdb.clear_objfiles" has been added, triggered when
255 selecting a new file to debug.
256 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
257 ** New function gdb.lookup_objfile.
259 New events which are triggered when GDB modifies the state of the
262 ** gdb.events.inferior_call_pre: Function call is about to be made.
263 ** gdb.events.inferior_call_post: Function call has just been made.
264 ** gdb.events.memory_changed: A memory location has been altered.
265 ** gdb.events.register_changed: A register has been altered.
267 * New Python-based convenience functions:
269 ** $_caller_is(name [, number_of_frames])
270 ** $_caller_matches(regexp [, number_of_frames])
271 ** $_any_caller_is(name [, number_of_frames])
272 ** $_any_caller_matches(regexp [, number_of_frames])
274 * GDB now supports the compilation and injection of source code into
275 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
276 to compile the source code to object code, and if successful, inject
277 and execute that code within the current context of the inferior.
278 Currently the C language is supported. The commands used to
279 interface with this new feature are:
281 compile code [-raw|-r] [--] [source code]
282 compile file [-raw|-r] filename
286 demangle [-l language] [--] name
287 Demangle "name" in the specified language, or the current language
288 if elided. This command is renamed from the "maint demangle" command.
289 The latter is kept as a no-op to avoid "maint demangle" being interpreted
290 as "maint demangler-warning".
292 queue-signal signal-name-or-number
293 Queue a signal to be delivered to the thread when it is resumed.
295 add-auto-load-scripts-directory directory
296 Add entries to the list of directories from which to load auto-loaded
299 maint print user-registers
300 List all currently available "user" registers.
302 compile code [-r|-raw] [--] [source code]
303 Compile, inject, and execute in the inferior the executable object
304 code produced by compiling the provided source code.
306 compile file [-r|-raw] filename
307 Compile and inject into the inferior the executable object code
308 produced by compiling the source code stored in the filename
311 * On resume, GDB now always passes the signal the program had stopped
312 for to the thread the signal was sent to, even if the user changed
313 threads before resuming. Previously GDB would often (but not
314 always) deliver the signal to the thread that happens to be current
317 * Conversely, the "signal" command now consistently delivers the
318 requested signal to the current thread. GDB now asks for
319 confirmation if the program had stopped for a signal and the user
320 switched threads meanwhile.
322 * "breakpoint always-inserted" modes "off" and "auto" merged.
324 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
325 won't remove breakpoints from the target until all threads stop,
326 even in non-stop mode. The "auto" mode has been removed, and "off"
327 is now the default mode.
331 set debug symbol-lookup
332 show debug symbol-lookup
333 Control display of debugging info regarding symbol lookup.
337 ** The -list-thread-groups command outputs an exit-code field for
338 inferiors that have exited.
342 MIPS SDE mips*-sde*-elf*
346 Support for these obsolete configurations has been removed.
348 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
349 SGI Irix-5.x mips-*-irix5*
350 SGI Irix-6.x mips-*-irix6*
351 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
352 VAX running Ultrix vax-*-ultrix*
354 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
355 and "assf"), have been removed. Use the "sharedlibrary" command, or
356 its alias "share", instead.
358 *** Changes in GDB 7.8
360 * New command line options
363 This is an alias for the --data-directory option.
365 * GDB supports printing and modifying of variable length automatic arrays
366 as specified in ISO C99.
368 * The ARM simulator now supports instruction level tracing
369 with or without disassembly.
373 GDB now has support for scripting using Guile. Whether this is
374 available is determined at configure time.
375 Guile version 2.0 or greater is required.
376 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
378 * New commands (for set/show, see "New options" below)
382 Invoke CODE by passing it to the Guile interpreter.
386 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
388 info auto-load guile-scripts [regexp]
389 Print the list of automatically loaded Guile scripts.
391 * The source command is now capable of sourcing Guile scripts.
392 This feature is dependent on the debugger being built with Guile support.
396 set print symbol-loading (off|brief|full)
397 show print symbol-loading
398 Control whether to print informational messages when loading symbol
399 information for a file. The default is "full", but when debugging
400 programs with large numbers of shared libraries the amount of output
403 set guile print-stack (none|message|full)
404 show guile print-stack
405 Show a stack trace when an error is encountered in a Guile script.
407 set auto-load guile-scripts (on|off)
408 show auto-load guile-scripts
409 Control auto-loading of Guile script files.
411 maint ada set ignore-descriptive-types (on|off)
412 maint ada show ignore-descriptive-types
413 Control whether the debugger should ignore descriptive types in Ada
414 programs. The default is not to ignore the descriptive types. See
415 the user manual for more details on descriptive types and the intended
416 usage of this option.
418 set auto-connect-native-target
420 Control whether GDB is allowed to automatically connect to the
421 native target for the run, attach, etc. commands when not connected
422 to any target yet. See also "target native" below.
424 set record btrace replay-memory-access (read-only|read-write)
425 show record btrace replay-memory-access
426 Control what memory accesses are allowed during replay.
428 maint set target-async (on|off)
429 maint show target-async
430 This controls whether GDB targets operate in synchronous or
431 asynchronous mode. Normally the default is asynchronous, if it is
432 available; but this can be changed to more easily debug problems
433 occurring only in synchronous mode.
435 set mi-async (on|off)
437 Control whether MI asynchronous mode is preferred. This supersedes
438 "set target-async" of previous GDB versions.
440 * "set target-async" is deprecated as a CLI option and is now an alias
441 for "set mi-async" (only puts MI into async mode).
443 * Background execution commands (e.g., "c&", "s&", etc.) are now
444 possible ``out of the box'' if the target supports them. Previously
445 the user would need to explicitly enable the possibility with the
446 "set target-async on" command.
448 * New features in the GDB remote stub, GDBserver
450 ** New option --debug-format=option1[,option2,...] allows one to add
451 additional text to each output. At present only timestamps
452 are supported: --debug-format=timestamps.
453 Timestamps can also be turned on with the
454 "monitor set debug-format timestamps" command from GDB.
456 * The 'record instruction-history' command now starts counting instructions
457 at one. This also affects the instruction ranges reported by the
458 'record function-call-history' command when given the /i modifier.
460 * The command 'record function-call-history' supports a new modifier '/c' to
461 indent the function names based on their call stack depth.
462 The fields for the '/i' and '/l' modifier have been reordered.
463 The source line range is now prefixed with 'at'.
464 The instruction range is now prefixed with 'inst'.
465 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
466 "record instruction-history" and "list" commands.
468 * The ranges given as arguments to the 'record function-call-history' and
469 'record instruction-history' commands are now inclusive.
471 * The btrace record target now supports the 'record goto' command.
472 For locations inside the execution trace, the back trace is computed
473 based on the information stored in the execution trace.
475 * The btrace record target supports limited reverse execution and replay.
476 The target does not record data and therefore does not allow reading
479 * The "catch syscall" command now works on s390*-linux* targets.
481 * The "compare-sections" command is no longer specific to target
482 remote. It now works with all targets.
484 * All native targets are now consistently called "native".
485 Consequently, the "target child", "target GNU", "target djgpp",
486 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
487 commands have been replaced with "target native". The QNX/NTO port
488 leaves the "procfs" target in place and adds a "native" target for
489 consistency with other ports. The impact on users should be minimal
490 as these commands previously either throwed an error, or were
491 no-ops. The target's name is visible in the output of the following
492 commands: "help target", "info target", "info files", "maint print
495 * The "target native" command now connects to the native target. This
496 can be used to launch native programs even when "set
497 auto-connect-native-target" is set to off.
499 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.
501 * Support for Intel(R) AVX-512 registers on GNU/Linux.
502 Support displaying and modifying Intel(R) AVX-512 registers
503 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
507 qXfer:btrace:read's annex
508 The qXfer:btrace:read packet supports a new annex 'delta' to read
509 branch trace incrementally.
513 ** Valid Python operations on gdb.Value objects representing
514 structs/classes invoke the corresponding overloaded operators if
516 ** New `Xmethods' feature in the Python API. Xmethods are
517 additional methods or replacements for existing methods of a C++
518 class. This feature is useful for those cases where a method
519 defined in C++ source code could be inlined or optimized out by
520 the compiler, making it unavailable to GDB.
523 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
525 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
526 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
527 its alias "share", instead.
529 * The commands "set remotebaud" and "show remotebaud" are no longer
530 supported. Use "set serial baud" and "show serial baud" (respectively)
535 ** A new option "-gdb-set mi-async" replaces "-gdb-set
536 target-async". The latter is left as a deprecated alias of the
537 former for backward compatibility. If the target supports it,
538 CLI background execution commands are now always possible by
539 default, independently of whether the frontend stated a
540 preference for asynchronous execution with "-gdb-set mi-async".
541 Previously "-gdb-set target-async off" affected both MI execution
542 commands and CLI execution commands.
544 *** Changes in GDB 7.7
546 * Improved support for process record-replay and reverse debugging on
547 arm*-linux* targets. Support for thumb32 and syscall instruction
548 recording has been added.
550 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
552 * GDB now supports Fission DWP file format version 2.
553 http://gcc.gnu.org/wiki/DebugFission
555 * New convenience function "$_isvoid", to check whether an expression
556 is void. A void expression is an expression where the type of the
557 result is "void". For example, some convenience variables may be
558 "void" when evaluated (e.g., "$_exitcode" before the execution of
559 the program being debugged; or an undefined convenience variable).
560 Another example, when calling a function whose return type is
563 * The "maintenance print objfiles" command now takes an optional regexp.
565 * The "catch syscall" command now works on arm*-linux* targets.
567 * GDB now consistently shows "<not saved>" when printing values of
568 registers the debug info indicates have not been saved in the frame
569 and there's nowhere to retrieve them from
570 (callee-saved/call-clobbered registers):
575 (gdb) info registers rax
578 Before, the former would print "<optimized out>", and the latter
579 "*value not available*".
581 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
586 ** Frame filters and frame decorators have been added.
587 ** Temporary breakpoints are now supported.
588 ** Line tables representation has been added.
589 ** New attribute 'parent_type' for gdb.Field objects.
590 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
591 ** New attribute 'name' for gdb.Type objects.
595 Nios II ELF nios2*-*-elf
596 Nios II GNU/Linux nios2*-*-linux
597 Texas Instruments MSP430 msp430*-*-elf
599 * Removed native configurations
601 Support for these a.out NetBSD and OpenBSD obsolete configurations has
602 been removed. ELF variants of these configurations are kept supported.
604 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
605 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
606 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
607 i[34567]86-*-openbsd3.[0-3]
608 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
609 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
610 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
614 Like "catch throw", but catches a re-thrown exception.
616 Renamed from old "maint check-symtabs".
618 Perform consistency checks on symtabs.
620 Expand symtabs matching an optional regexp.
623 Display the details of GDB configure-time options.
625 maint set|show per-command
626 maint set|show per-command space
627 maint set|show per-command time
628 maint set|show per-command symtab
629 Enable display of per-command gdb resource usage.
631 remove-symbol-file FILENAME
632 remove-symbol-file -a ADDRESS
633 Remove a symbol file added via add-symbol-file. The file to remove
634 can be identified by its filename or by an address that lies within
635 the boundaries of this symbol file in memory.
638 info exceptions REGEXP
639 Display the list of Ada exceptions defined in the program being
640 debugged. If provided, only the exceptions whose names match REGEXP
645 set debug symfile off|on
647 Control display of debugging info regarding reading symbol files and
648 symbol tables within those files
650 set print raw frame-arguments
651 show print raw frame-arguments
652 Set/show whether to print frame arguments in raw mode,
653 disregarding any defined pretty-printers.
655 set remote trace-status-packet
656 show remote trace-status-packet
657 Set/show the use of remote protocol qTStatus packet.
661 Control display of debugging messages related to Nios II targets.
665 Control whether target-assisted range stepping is enabled.
667 set startup-with-shell
668 show startup-with-shell
669 Specifies whether Unix child processes are started via a shell or
674 Use the target memory cache for accesses to the code segment. This
675 improves performance of remote debugging (particularly disassembly).
677 * You can now use a literal value 'unlimited' for options that
678 interpret 0 or -1 as meaning "unlimited". E.g., "set
679 trace-buffer-size unlimited" is now an alias for "set
680 trace-buffer-size -1" and "set height unlimited" is now an alias for
683 * The "set debug symtab-create" debugging option of GDB has been changed to
684 accept a verbosity level. 0 means "off", 1 provides basic debugging
685 output, and values of 2 or greater provides more verbose output.
687 * New command-line options
689 Display the details of GDB configure-time options.
691 * The command 'tsave' can now support new option '-ctf' to save trace
692 buffer in Common Trace Format.
694 * Newly installed $prefix/bin/gcore acts as a shell interface for the
697 * GDB now implements the the C++ 'typeid' operator.
699 * The new convenience variable $_exception holds the exception being
700 thrown or caught at an exception-related catchpoint.
702 * The exception-related catchpoints, like "catch throw", now accept a
703 regular expression which can be used to filter exceptions by type.
705 * The new convenience variable $_exitsignal is automatically set to
706 the terminating signal number when the program being debugged dies
707 due to an uncaught signal.
711 ** All MI commands now accept an optional "--language" option.
712 Support for this feature can be verified by using the "-list-features"
713 command, which should contain "language-option".
715 ** The new command -info-gdb-mi-command allows the user to determine
716 whether a GDB/MI command is supported or not.
718 ** The "^error" result record returned when trying to execute an undefined
719 GDB/MI command now provides a variable named "code" whose content is the
720 "undefined-command" error code. Support for this feature can be verified
721 by using the "-list-features" command, which should contain
722 "undefined-command-error-code".
724 ** The -trace-save MI command can optionally save trace buffer in Common
727 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
729 ** The command -data-list-register-values now accepts an optional
730 "--skip-unavailable" option. When used, only the available registers
733 ** The new command -trace-frame-collected dumps collected variables,
734 computed expressions, tvars, memory and registers in a traceframe.
736 ** The commands -stack-list-locals, -stack-list-arguments and
737 -stack-list-variables now accept an option "--skip-unavailable".
738 When used, only the available locals or arguments are displayed.
740 ** The -exec-run command now accepts an optional "--start" option.
741 When used, the command follows the same semantics as the "start"
742 command, stopping the program's execution at the start of its
743 main subprogram. Support for this feature can be verified using
744 the "-list-features" command, which should contain
745 "exec-run-start-option".
747 ** The new commands -catch-assert and -catch-exceptions insert
748 catchpoints stopping the program when Ada exceptions are raised.
750 ** The new command -info-ada-exceptions provides the equivalent of
751 the new "info exceptions" command.
753 * New system-wide configuration scripts
754 A GDB installation now provides scripts suitable for use as system-wide
755 configuration scripts for the following systems:
759 * GDB now supports target-assigned range stepping with remote targets.
760 This improves the performance of stepping source lines by reducing
761 the number of control packets from/to GDB. See "New remote packets"
764 * GDB now understands the element 'tvar' in the XML traceframe info.
765 It has the id of the collected trace state variables.
767 * On S/390 targets that provide the transactional-execution feature,
768 the program interruption transaction diagnostic block (TDB) is now
769 represented as a number of additional "registers" in GDB.
775 The vCont packet supports a new 'r' action, that tells the remote
776 stub to step through an address range itself, without GDB
777 involvemement at each single-step.
779 qXfer:libraries-svr4:read's annex
780 The previously unused annex of the qXfer:libraries-svr4:read packet
781 is now used to support passing an argument list. The remote stub
782 reports support for this argument list to GDB's qSupported query.
783 The defined arguments are "start" and "prev", used to reduce work
784 necessary for library list updating, resulting in significant
787 * New features in the GDB remote stub, GDBserver
789 ** GDBserver now supports target-assisted range stepping. Currently
790 enabled on x86/x86_64 GNU/Linux targets.
792 ** GDBserver now adds element 'tvar' in the XML in the reply to
793 'qXfer:traceframe-info:read'. It has the id of the collected
794 trace state variables.
796 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
799 * New 'z' formatter for printing and examining memory, this displays the
800 value as hexadecimal zero padded on the left to the size of the type.
802 * GDB can now use Windows x64 unwinding data.
804 * The "set remotebaud" command has been replaced by "set serial baud".
805 Similarly, "show remotebaud" has been replaced by "show serial baud".
806 The "set remotebaud" and "show remotebaud" commands are still available
807 to provide backward compatibility with older versions of GDB.
809 *** Changes in GDB 7.6
811 * Target record has been renamed to record-full.
812 Record/replay is now enabled with the "record full" command.
813 This also affects settings that are associated with full record/replay
814 that have been moved from "set/show record" to "set/show record full":
816 set|show record full insn-number-max
817 set|show record full stop-at-limit
818 set|show record full memory-query
820 * A new record target "record-btrace" has been added. The new target
821 uses hardware support to record the control-flow of a process. It
822 does not support replaying the execution, but it implements the
823 below new commands for investigating the recorded execution log.
824 This new recording method can be enabled using:
828 The "record-btrace" target is only available on Intel Atom processors
829 and requires a Linux kernel 2.6.32 or later.
831 * Two new commands have been added for record/replay to give information
832 about the recorded execution without having to replay the execution.
833 The commands are only supported by "record btrace".
835 record instruction-history prints the execution history at
836 instruction granularity
838 record function-call-history prints the execution history at
841 * New native configurations
843 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
844 FreeBSD/powerpc powerpc*-*-freebsd
845 x86_64/Cygwin x86_64-*-cygwin*
846 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
850 ARM AArch64 aarch64*-*-elf
851 ARM AArch64 GNU/Linux aarch64*-*-linux
852 Lynx 178 PowerPC powerpc-*-lynx*178
853 x86_64/Cygwin x86_64-*-cygwin*
854 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
856 * If the configured location of system.gdbinit file (as given by the
857 --with-system-gdbinit option at configure time) is in the
858 data-directory (as specified by --with-gdb-datadir at configure
859 time) or in one of its subdirectories, then GDB will look for the
860 system-wide init file in the directory specified by the
861 --data-directory command-line option.
863 * New command line options:
865 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
866 other initialization files, unlike -nx which disables all of them.
868 * Removed command line options
870 -epoch This was used by the gdb mode in Epoch, an ancient fork of
873 * The 'ptype' and 'whatis' commands now accept an argument to control
876 * 'info proc' now works on some core files.
880 ** Vectors can be created with gdb.Type.vector.
882 ** Python's atexit.register now works in GDB.
884 ** Types can be pretty-printed via a Python API.
886 ** Python 3 is now supported (in addition to Python 2.4 or later)
888 ** New class gdb.Architecture exposes GDB's internal representation
889 of architecture in the Python API.
891 ** New method Frame.architecture returns the gdb.Architecture object
892 corresponding to the frame's architecture.
894 * New Python-based convenience functions:
896 ** $_memeq(buf1, buf2, length)
897 ** $_streq(str1, str2)
899 ** $_regex(str, regex)
901 * The 'cd' command now defaults to using '~' (the home directory) if not
904 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
905 default for GCC since November 2000.
907 * The command 'forward-search' can now be abbreviated as 'fo'.
909 * The command 'info tracepoints' can now display 'installed on target'
910 or 'not installed on target' for each non-pending location of tracepoint.
912 * New configure options
914 --enable-libmcheck/--disable-libmcheck
915 By default, development versions are built with -lmcheck on hosts
916 that support it, in order to help track memory corruption issues.
917 Release versions, on the other hand, are built without -lmcheck
918 by default. The --enable-libmcheck/--disable-libmcheck configure
919 options allow the user to override that default.
920 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
921 This configure option allows the user to build GDB with
922 libbabeltrace using which GDB can read Common Trace Format data.
924 * New commands (for set/show, see "New options" below)
927 Catch signals. This is similar to "handle", but allows commands and
928 conditions to be attached.
931 List the BFDs known to GDB.
933 python-interactive [command]
935 Start a Python interactive prompt, or evaluate the optional command
936 and print the result of expressions.
939 "py" is a new alias for "python".
941 enable type-printer [name]...
942 disable type-printer [name]...
943 Enable or disable type printers.
947 ** For the Renesas Super-H architecture, the "regs" command has been removed
948 (has been deprecated in GDB 7.5), and "info all-registers" should be used
953 set print type methods (on|off)
954 show print type methods
955 Control whether method declarations are displayed by "ptype".
956 The default is to show them.
958 set print type typedefs (on|off)
959 show print type typedefs
960 Control whether typedef definitions are displayed by "ptype".
961 The default is to show them.
963 set filename-display basename|relative|absolute
964 show filename-display
965 Control the way in which filenames is displayed.
966 The default is "relative", which preserves previous behavior.
968 set trace-buffer-size
969 show trace-buffer-size
970 Request target to change the size of trace buffer.
972 set remote trace-buffer-size-packet auto|on|off
973 show remote trace-buffer-size-packet
974 Control the use of the remote protocol `QTBuffer:size' packet.
978 Control display of debugging messages related to ARM AArch64.
981 set debug coff-pe-read
982 show debug coff-pe-read
983 Control display of debugging messages related to reading of COFF/PE
988 Control display of debugging messages related to Mach-O symbols
991 set debug notification
992 show debug notification
993 Control display of debugging info for async remote notification.
997 ** Command parameter changes are now notified using new async record
998 "=cmd-param-changed".
999 ** Trace frame changes caused by command "tfind" are now notified using
1000 new async record "=traceframe-changed".
1001 ** The creation, deletion and modification of trace state variables
1002 are now notified using new async records "=tsv-created",
1003 "=tsv-deleted" and "=tsv-modified".
1004 ** The start and stop of process record are now notified using new
1005 async record "=record-started" and "=record-stopped".
1006 ** Memory changes are now notified using new async record
1008 ** The data-disassemble command response will include a "fullname" field
1009 containing the absolute file name when source has been requested.
1010 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1011 command, to allow pattern filling of memory areas.
1012 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1013 library load/unload events.
1014 ** The response to breakpoint commands and breakpoint async records
1015 includes an "installed" field containing a boolean state about each
1016 non-pending tracepoint location is whether installed on target or not.
1017 ** Output of the "-trace-status" command includes a "trace-file" field
1018 containing the name of the trace file being examined. This field is
1019 optional, and only present when examining a trace file.
1020 ** The "fullname" field is now always present along with the "file" field,
1021 even if the file cannot be found by GDB.
1023 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1024 You must have the LZMA library available when configuring GDB for this
1025 feature to be enabled. For more information, see:
1026 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1028 * New remote packets
1031 Set the size of trace buffer. The remote stub reports support for this
1032 packet to gdb's qSupported query.
1035 Enable Branch Trace Store (BTS)-based branch tracing for the current
1036 thread. The remote stub reports support for this packet to gdb's
1040 Disable branch tracing for the current thread. The remote stub reports
1041 support for this packet to gdb's qSupported query.
1044 Read the traced branches for the current thread. The remote stub
1045 reports support for this packet to gdb's qSupported query.
1047 *** Changes in GDB 7.5
1049 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1050 for more x32 ABI info.
1052 * GDB now supports access to MIPS DSP registers on Linux targets.
1054 * GDB now supports debugging microMIPS binaries.
1056 * The "info os" command on GNU/Linux can now display information on
1057 several new classes of objects managed by the operating system:
1058 "info os procgroups" lists process groups
1059 "info os files" lists file descriptors
1060 "info os sockets" lists internet-domain sockets
1061 "info os shm" lists shared-memory regions
1062 "info os semaphores" lists semaphores
1063 "info os msg" lists message queues
1064 "info os modules" lists loaded kernel modules
1066 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1067 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1068 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1069 options and inspect the probe arguments using the new $_probe_arg family
1070 of convenience variables. You can obtain more information about SystemTap
1071 in <http://sourceware.org/systemtap/>.
1073 * GDB now supports reversible debugging on ARM, it allows you to
1074 debug basic ARM and THUMB instructions, and provides
1075 record/replay support.
1077 * The option "symbol-reloading" has been deleted as it is no longer used.
1081 ** GDB commands implemented in Python can now be put in command class
1084 ** The "maint set python print-stack on|off" is now deleted.
1086 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1087 apply "flag enum"-style pretty-printing to any enum.
1089 ** gdb.lookup_symbol can now work when there is no current frame.
1091 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1092 the source at which the symbol was defined.
1094 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1095 method 'value'. The former indicates whether the symbol needs a
1096 frame in order to compute its value, and the latter computes the
1099 ** A new method 'referenced_value' on gdb.Value objects which can
1100 dereference pointer as well as C++ reference values.
1102 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1103 which return the global and static blocks (as gdb.Block objects),
1104 of the underlying symbol table, respectively.
1106 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1107 object associated with a PC value.
1109 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1110 of the address range occupied by code for the current source line.
1112 * Go language support.
1113 GDB now supports debugging programs written in the Go programming
1116 * GDBserver now supports stdio connections.
1117 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1119 * The binary "gdbtui" can no longer be built or installed.
1120 Use "gdb -tui" instead.
1122 * GDB will now print "flag" enums specially. A flag enum is one where
1123 all the enumerator values have no bits in common when pairwise
1124 "and"ed. When printing a value whose type is a flag enum, GDB will
1125 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1126 (gdb) print (enum E) 3
1129 * The filename part of a linespec will now match trailing components
1130 of a source file name. For example, "break gcc/expr.c:1000" will
1131 now set a breakpoint in build/gcc/expr.c, but not
1132 build/libcpp/expr.c.
1134 * The "info proc" and "generate-core-file" commands will now also
1135 work on remote targets connected to GDBserver on Linux.
1137 * The command "info catch" has been removed. It has been disabled
1138 since December 2007.
1140 * The "catch exception" and "catch assert" commands now accept
1141 a condition at the end of the command, much like the "break"
1142 command does. For instance:
1144 (gdb) catch exception Constraint_Error if Barrier = True
1146 Previously, it was possible to add a condition to such catchpoints,
1147 but it had to be done as a second step, after the catchpoint had been
1148 created, using the "condition" command.
1150 * The "info static-tracepoint-marker" command will now also work on
1151 native Linux targets with in-process agent.
1153 * GDB can now set breakpoints on inlined functions.
1155 * The .gdb_index section has been updated to include symbols for
1156 inlined functions. GDB will ignore older .gdb_index sections by
1157 default, which could cause symbol files to be loaded more slowly
1158 until their .gdb_index sections can be recreated. The new command
1159 "set use-deprecated-index-sections on" will cause GDB to use any older
1160 .gdb_index sections it finds. This will restore performance, but the
1161 ability to set breakpoints on inlined functions will be lost in symbol
1162 files with older .gdb_index sections.
1164 The .gdb_index section has also been updated to record more information
1165 about each symbol. This speeds up the "info variables", "info functions"
1166 and "info types" commands when used with programs having the .gdb_index
1167 section, as well as speeding up debugging with shared libraries using
1168 the .gdb_index section.
1170 * Ada support for GDB/MI Variable Objects has been added.
1172 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1177 ** New command -info-os is the MI equivalent of "info os".
1179 ** Output logs ("set logging" and related) now include MI output.
1183 ** "set use-deprecated-index-sections on|off"
1184 "show use-deprecated-index-sections on|off"
1185 Controls the use of deprecated .gdb_index sections.
1187 ** "catch load" and "catch unload" can be used to stop when a shared
1188 library is loaded or unloaded, respectively.
1190 ** "enable count" can be used to auto-disable a breakpoint after
1193 ** "info vtbl" can be used to show the virtual method tables for
1194 C++ and Java objects.
1196 ** "explore" and its sub commands "explore value" and "explore type"
1197 can be used to recursively explore values and types of
1198 expressions. These commands are available only if GDB is
1199 configured with '--with-python'.
1201 ** "info auto-load" shows status of all kinds of auto-loaded files,
1202 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1203 sequences of commands files, "info auto-load python-scripts"
1204 shows status of auto-loading Python script files,
1205 "info auto-load local-gdbinit" shows status of loading init file
1206 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1207 status of inferior specific thread debugging shared library loading.
1209 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1210 and "show auto-load-scripts" commands have been deprecated, use their
1211 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1212 and "show auto-load python-scripts" counterparts instead.
1214 ** "dprintf location,format,args..." creates a dynamic printf, which
1215 is basically a breakpoint that does a printf and immediately
1216 resumes your program's execution, so it is like a printf that you
1217 can insert dynamically at runtime instead of at compiletime.
1219 ** "set print symbol"
1221 Controls whether GDB attempts to display the symbol, if any,
1222 corresponding to addresses it prints. This defaults to "on", but
1223 you can set it to "off" to restore GDB's previous behavior.
1225 * Deprecated commands
1227 ** For the Renesas Super-H architecture, the "regs" command has been
1228 deprecated, and "info all-registers" should be used instead.
1232 Renesas RL78 rl78-*-elf
1233 HP OpenVMS ia64 ia64-hp-openvms*
1235 * GDBserver supports evaluation of breakpoint conditions. When
1236 support is advertised by GDBserver, GDB may be told to send the
1237 breakpoint conditions in bytecode form to GDBserver. GDBserver
1238 will only report the breakpoint trigger to GDB when its condition
1243 set mips compression
1244 show mips compression
1245 Select the compressed ISA encoding used in functions that have no symbol
1246 information available. The encoding can be set to either of:
1249 and is updated automatically from ELF file flags if available.
1251 set breakpoint condition-evaluation
1252 show breakpoint condition-evaluation
1253 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1254 GDBserver ("target"). Default option "auto" chooses the most efficient
1256 This option can improve debugger efficiency depending on the speed of the
1260 Disable auto-loading globally.
1263 Show auto-loading setting of all kinds of auto-loaded files.
1265 set auto-load gdb-scripts on|off
1266 show auto-load gdb-scripts
1267 Control auto-loading of GDB canned sequences of commands files.
1269 set auto-load python-scripts on|off
1270 show auto-load python-scripts
1271 Control auto-loading of Python script files.
1273 set auto-load local-gdbinit on|off
1274 show auto-load local-gdbinit
1275 Control loading of init file (.gdbinit) from current directory.
1277 set auto-load libthread-db on|off
1278 show auto-load libthread-db
1279 Control auto-loading of inferior specific thread debugging shared library.
1281 set auto-load scripts-directory <dir1>[:<dir2>...]
1282 show auto-load scripts-directory
1283 Set a list of directories from which to load auto-loaded scripts.
1284 Automatically loaded Python scripts and GDB scripts are located in one
1285 of the directories listed by this option.
1286 The delimiter (':' above) may differ according to the host platform.
1288 set auto-load safe-path <dir1>[:<dir2>...]
1289 show auto-load safe-path
1290 Set a list of directories from which it is safe to auto-load files.
1291 The delimiter (':' above) may differ according to the host platform.
1293 set debug auto-load on|off
1294 show debug auto-load
1295 Control display of debugging info for auto-loading the files above.
1297 set dprintf-style gdb|call|agent
1299 Control the way in which a dynamic printf is performed; "gdb"
1300 requests a GDB printf command, while "call" causes dprintf to call a
1301 function in the inferior. "agent" requests that the target agent
1302 (such as GDBserver) do the printing.
1304 set dprintf-function <expr>
1305 show dprintf-function
1306 set dprintf-channel <expr>
1307 show dprintf-channel
1308 Set the function and optional first argument to the call when using
1309 the "call" style of dynamic printf.
1311 set disconnected-dprintf on|off
1312 show disconnected-dprintf
1313 Control whether agent-style dynamic printfs continue to be in effect
1314 after GDB disconnects.
1316 * New configure options
1318 --with-auto-load-dir
1319 Configure default value for the 'set auto-load scripts-directory'
1320 setting above. It defaults to '$debugdir:$datadir/auto-load',
1321 $debugdir representing global debugging info directories (available
1322 via 'show debug-file-directory') and $datadir representing GDB's data
1323 directory (available via 'show data-directory').
1325 --with-auto-load-safe-path
1326 Configure default value for the 'set auto-load safe-path' setting
1327 above. It defaults to the --with-auto-load-dir setting.
1329 --without-auto-load-safe-path
1330 Set 'set auto-load safe-path' to '/', effectively disabling this
1333 * New remote packets
1335 z0/z1 conditional breakpoints extension
1337 The z0/z1 breakpoint insertion packets have been extended to carry
1338 a list of conditional expressions over to the remote stub depending on the
1339 condition evaluation mode. The use of this extension can be controlled
1340 via the "set remote conditional-breakpoints-packet" command.
1344 Specify the signals which the remote stub may pass to the debugged
1345 program without GDB involvement.
1347 * New command line options
1349 --init-command=FILE, -ix Like --command, -x but execute it
1350 before loading inferior.
1351 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1352 execute it before loading inferior.
1354 *** Changes in GDB 7.4
1356 * GDB now handles ambiguous linespecs more consistently; the existing
1357 FILE:LINE support has been expanded to other types of linespecs. A
1358 breakpoint will now be set on all matching locations in all
1359 inferiors, and locations will be added or removed according to
1362 * GDB now allows you to skip uninteresting functions and files when
1363 stepping with the "skip function" and "skip file" commands.
1365 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1366 and "show remote hardware-watchpoint-length-limit". These allows to
1367 set or show the maximum length limit (in bytes) of a remote
1368 target hardware watchpoint.
1370 This allows e.g. to use "unlimited" hardware watchpoints with the
1371 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1372 watchpoints are slower than real hardware watchpoints but are
1373 significantly faster than gdb software watchpoints.
1377 ** The register_pretty_printer function in module gdb.printing now takes
1378 an optional `replace' argument. If True, the new printer replaces any
1381 ** The "maint set python print-stack on|off" command has been
1382 deprecated and will be deleted in GDB 7.5.
1383 A new command: "set python print-stack none|full|message" has
1384 replaced it. Additionally, the default for "print-stack" is
1385 now "message", which just prints the error message without
1388 ** A prompt substitution hook (prompt_hook) is now available to the
1391 ** A new Python module, gdb.prompt has been added to the GDB Python
1392 modules library. This module provides functionality for
1393 escape sequences in prompts (used by set/show
1394 extended-prompt). These escape sequences are replaced by their
1395 corresponding value.
1397 ** Python commands and convenience-functions located in
1398 'data-directory'/python/gdb/command and
1399 'data-directory'/python/gdb/function are now automatically loaded
1402 ** Blocks now provide four new attributes. global_block and
1403 static_block will return the global and static blocks
1404 respectively. is_static and is_global are boolean attributes
1405 that indicate if the block is one of those two types.
1407 ** Symbols now provide the "type" attribute, the type of the symbol.
1409 ** The "gdb.breakpoint" function has been deprecated in favor of
1412 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1413 of a function. This class is based on the "finish" command
1414 available in the CLI.
1416 ** Type objects for struct and union types now allow access to
1417 the fields using standard Python dictionary (mapping) methods.
1418 For example, "some_type['myfield']" now works, as does
1419 "some_type.items()".
1421 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1424 ** A new function, "deep_items" has been added to the gdb.types
1425 module in the GDB Python modules library. This function returns
1426 an iterator over the fields of a struct or union type. Unlike
1427 the standard Python "iteritems" method, it will recursively traverse
1428 any anonymous fields.
1432 ** "*stopped" events can report several new "reason"s, such as
1435 ** Breakpoint changes are now notified using new async records, like
1436 "=breakpoint-modified".
1438 ** New command -ada-task-info.
1440 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1441 $sdir specifies the default system locations of shared libraries.
1442 $pdir specifies the directory where the libpthread used by the application
1445 GDB no longer looks in $sdir and $pdir after it has searched the directories
1446 mentioned in libthread-db-search-path. If you want to search those
1447 directories, they must be specified in libthread-db-search-path.
1448 The default value of libthread-db-search-path on GNU/Linux and Solaris
1449 systems is now "$sdir:$pdir".
1451 $pdir is not supported by gdbserver, it is currently ignored.
1452 $sdir is supported by gdbserver.
1454 * New configure option --with-iconv-bin.
1455 When using the internationalization support like the one in the GNU C
1456 library, GDB will invoke the "iconv" program to get a list of supported
1457 character sets. If this program lives in a non-standard location, one can
1458 use this option to specify where to find it.
1460 * When natively debugging programs on PowerPC BookE processors running
1461 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1462 watchpoints, which specify a mask in addition to an address to watch.
1463 The mask specifies that some bits of an address (the bits which are
1464 reset in the mask) should be ignored when matching the address accessed
1465 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1466 section in the user manual for more details.
1468 * The new option --once causes GDBserver to stop listening for connections once
1469 the first connection is made. The listening port used by GDBserver will
1470 become available after that.
1472 * New commands "info macros" and "alias" have been added.
1474 * New function parameters suffix @entry specifies value of function parameter
1475 at the time the function got called. Entry values are available only since
1481 "!" is now an alias of the "shell" command.
1482 Note that no space is needed between "!" and SHELL COMMAND.
1486 watch EXPRESSION mask MASK_VALUE
1487 The watch command now supports the mask argument which allows creation
1488 of masked watchpoints, if the current architecture supports this feature.
1490 info auto-load-scripts [REGEXP]
1491 This command was formerly named "maintenance print section-scripts".
1492 It is now generally useful and is no longer a maintenance-only command.
1494 info macro [-all] [--] MACRO
1495 The info macro command has new options `-all' and `--'. The first for
1496 printing all definitions of a macro. The second for explicitly specifying
1497 the end of arguments and the beginning of the macro name in case the macro
1498 name starts with a hyphen.
1500 collect[/s] EXPRESSIONS
1501 The tracepoint collect command now takes an optional modifier "/s"
1502 that directs it to dereference pointer-to-character types and
1503 collect the bytes of memory up to a zero byte. The behavior is
1504 similar to what you see when you use the regular print command on a
1505 string. An optional integer following the "/s" sets a bound on the
1506 number of bytes that will be collected.
1509 The trace start command now interprets any supplied arguments as a
1510 note to be recorded with the trace run, with an effect similar to
1511 setting the variable trace-notes.
1514 The trace stop command now interprets any arguments as a note to be
1515 mentioned along with the tstatus report that the trace was stopped
1516 with a command. The effect is similar to setting the variable
1519 * Tracepoints can now be enabled and disabled at any time after a trace
1520 experiment has been started using the standard "enable" and "disable"
1521 commands. It is now possible to start a trace experiment with no enabled
1522 tracepoints; GDB will display a warning, but will allow the experiment to
1523 begin, assuming that tracepoints will be enabled as needed while the trace
1526 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1527 locations with 4-byte instructions, when they were previously
1528 limited to locations with instructions of 5 bytes or longer.
1532 set debug dwarf2-read
1533 show debug dwarf2-read
1534 Turns on or off display of debugging messages related to reading
1535 DWARF debug info. The default is off.
1537 set debug symtab-create
1538 show debug symtab-create
1539 Turns on or off display of debugging messages related to symbol table
1540 creation. The default is off.
1543 show extended-prompt
1544 Set the GDB prompt, and allow escape sequences to be inserted to
1545 display miscellaneous information (see 'help set extended-prompt'
1546 for the list of sequences). This prompt (and any information
1547 accessed through the escape sequences) is updated every time the
1548 prompt is displayed.
1550 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1551 show print entry-values
1552 Set printing of frame argument values at function entry. In some cases
1553 GDB can determine the value of function argument which was passed by the
1554 function caller, even if the value was modified inside the called function.
1556 set debug entry-values
1557 show debug entry-values
1558 Control display of debugging info for determining frame argument values at
1559 function entry and virtual tail call frames.
1561 set basenames-may-differ
1562 show basenames-may-differ
1563 Set whether a source file may have multiple base names.
1564 (A "base name" is the name of a file with the directory part removed.
1565 Example: The base name of "/home/user/hello.c" is "hello.c".)
1566 If set, GDB will canonicalize file names (e.g., expand symlinks)
1567 before comparing them. Canonicalization is an expensive operation,
1568 but it allows the same file be known by more than one base name.
1569 If not set (the default), all source files are assumed to have just
1570 one base name, and gdb will do file name comparisons more efficiently.
1576 Set a user name and notes for the current and any future trace runs.
1577 This is useful for long-running and/or disconnected traces, to
1578 inform others (or yourself) as to who is running the trace, supply
1579 contact information, or otherwise explain what is going on.
1581 set trace-stop-notes
1582 show trace-stop-notes
1583 Set a note attached to the trace run, that is displayed when the
1584 trace has been stopped by a tstop command. This is useful for
1585 instance as an explanation, if you are stopping a trace run that was
1586 started by someone else.
1588 * New remote packets
1592 Dynamically enable a tracepoint in a started trace experiment.
1596 Dynamically disable a tracepoint in a started trace experiment.
1600 Set the user and notes of the trace run.
1604 Query the current status of a tracepoint.
1608 Query the minimum length of instruction at which a fast tracepoint may
1611 * Dcache size (number of lines) and line-size are now runtime-configurable
1612 via "set dcache line" and "set dcache line-size" commands.
1616 Texas Instruments TMS320C6x tic6x-*-*
1620 Renesas RL78 rl78-*-elf
1622 *** Changes in GDB 7.3.1
1624 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1626 *** Changes in GDB 7.3
1628 * GDB has a new command: "thread find [REGEXP]".
1629 It finds the thread id whose name, target id, or thread extra info
1630 matches the given regular expression.
1632 * The "catch syscall" command now works on mips*-linux* targets.
1634 * The -data-disassemble MI command now supports modes 2 and 3 for
1635 dumping the instruction opcodes.
1637 * New command line options
1639 -data-directory DIR Specify DIR as the "data-directory".
1640 This is mostly for testing purposes.
1642 * The "maint set python auto-load on|off" command has been renamed to
1643 "set auto-load-scripts on|off".
1645 * GDB has a new command: "set directories".
1646 It is like the "dir" command except that it replaces the
1647 source path list instead of augmenting it.
1649 * GDB now understands thread names.
1651 On GNU/Linux, "info threads" will display the thread name as set by
1652 prctl or pthread_setname_np.
1654 There is also a new command, "thread name", which can be used to
1655 assign a name internally for GDB to display.
1658 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1659 has been integrated into GDB.
1663 ** The function gdb.Write now accepts an optional keyword 'stream'.
1664 This keyword, when provided, will direct the output to either
1665 stdout, stderr, or GDB's logging output.
1667 ** Parameters can now be be sub-classed in Python, and in particular
1668 you may implement the get_set_doc and get_show_doc functions.
1669 This improves how Parameter set/show documentation is processed
1670 and allows for more dynamic content.
1672 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1673 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1674 have an is_valid method.
1676 ** Breakpoints can now be sub-classed in Python, and in particular
1677 you may implement a 'stop' function that is executed each time
1678 the inferior reaches that breakpoint.
1680 ** New function gdb.lookup_global_symbol looks up a global symbol.
1682 ** GDB values in Python are now callable if the value represents a
1683 function. For example, if 'some_value' represents a function that
1684 takes two integer parameters and returns a value, you can call
1685 that function like so:
1687 result = some_value (10,20)
1689 ** Module gdb.types has been added.
1690 It contains a collection of utilities for working with gdb.Types objects:
1691 get_basic_type, has_field, make_enum_dict.
1693 ** Module gdb.printing has been added.
1694 It contains utilities for writing and registering pretty-printers.
1695 New classes: PrettyPrinter, SubPrettyPrinter,
1696 RegexpCollectionPrettyPrinter.
1697 New function: register_pretty_printer.
1699 ** New commands "info pretty-printers", "enable pretty-printer" and
1700 "disable pretty-printer" have been added.
1702 ** gdb.parameter("directories") is now available.
1704 ** New function gdb.newest_frame returns the newest frame in the
1707 ** The gdb.InferiorThread class has a new "name" attribute. This
1708 holds the thread's name.
1710 ** Python Support for Inferior events.
1711 Python scripts can add observers to be notified of events
1712 occurring in the process being debugged.
1713 The following events are currently supported:
1714 - gdb.events.cont Continue event.
1715 - gdb.events.exited Inferior exited event.
1716 - gdb.events.stop Signal received, and Breakpoint hit events.
1720 ** GDB now puts template parameters in scope when debugging in an
1721 instantiation. For example, if you have:
1723 template<int X> int func (void) { return X; }
1725 then if you step into func<5>, "print X" will show "5". This
1726 feature requires proper debuginfo support from the compiler; it
1727 was added to GCC 4.5.
1729 ** The motion commands "next", "finish", "until", and "advance" now
1730 work better when exceptions are thrown. In particular, GDB will
1731 no longer lose control of the inferior; instead, the GDB will
1732 stop the inferior at the point at which the exception is caught.
1733 This functionality requires a change in the exception handling
1734 code that was introduced in GCC 4.5.
1736 * GDB now follows GCC's rules on accessing volatile objects when
1737 reading or writing target state during expression evaluation.
1738 One notable difference to prior behavior is that "print x = 0"
1739 no longer generates a read of x; the value of the assignment is
1740 now always taken directly from the value being assigned.
1742 * GDB now has some support for using labels in the program's source in
1743 linespecs. For instance, you can use "advance label" to continue
1744 execution to a label.
1746 * GDB now has support for reading and writing a new .gdb_index
1747 section. This section holds a fast index of DWARF debugging
1748 information and can be used to greatly speed up GDB startup and
1749 operation. See the documentation for `save gdb-index' for details.
1751 * The "watch" command now accepts an optional "-location" argument.
1752 When used, this causes GDB to watch the memory referred to by the
1753 expression. Such a watchpoint is never deleted due to it going out
1756 * GDB now supports thread debugging of core dumps on GNU/Linux.
1758 GDB now activates thread debugging using the libthread_db library
1759 when debugging GNU/Linux core dumps, similarly to when debugging
1760 live processes. As a result, when debugging a core dump file, GDB
1761 is now able to display pthread_t ids of threads. For example, "info
1762 threads" shows the same output as when debugging the process when it
1763 was live. In earlier releases, you'd see something like this:
1766 * 1 LWP 6780 main () at main.c:10
1768 While now you see this:
1771 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1773 It is also now possible to inspect TLS variables when debugging core
1776 When debugging a core dump generated on a machine other than the one
1777 used to run GDB, you may need to point GDB at the correct
1778 libthread_db library with the "set libthread-db-search-path"
1779 command. See the user manual for more details on this command.
1781 * When natively debugging programs on PowerPC BookE processors running
1782 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1783 which stop execution of the inferior whenever it executes an instruction
1784 at any address within the specified range. See the "PowerPC Embedded"
1785 section in the user manual for more details.
1787 * New features in the GDB remote stub, GDBserver
1789 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1790 and i686 LynxOS (version 5.x).
1792 ** GDBserver is now supported on Blackfin Linux.
1794 * New native configurations
1796 ia64 HP-UX ia64-*-hpux*
1800 Analog Devices, Inc. Blackfin Processor bfin-*
1802 * Ada task switching is now supported on sparc-elf targets when
1803 debugging a program using the Ravenscar Profile. For more information,
1804 see the "Tasking Support when using the Ravenscar Profile" section
1805 in the GDB user manual.
1807 * Guile support was removed.
1809 * New features in the GNU simulator
1811 ** The --map-info flag lists all known core mappings.
1813 ** CFI flashes may be simulated via the "cfi" device.
1815 *** Changes in GDB 7.2
1817 * Shared library support for remote targets by default
1819 When GDB is configured for a generic, non-OS specific target, like
1820 for example, --target=arm-eabi or one of the many *-*-elf targets,
1821 GDB now queries remote stubs for loaded shared libraries using the
1822 `qXfer:libraries:read' packet. Previously, shared library support
1823 was always disabled for such configurations.
1827 ** Argument Dependent Lookup (ADL)
1829 In C++ ADL lookup directs function search to the namespaces of its
1830 arguments even if the namespace has not been imported.
1840 Here the compiler will search for `foo' in the namespace of 'b'
1841 and find A::foo. GDB now supports this. This construct is commonly
1842 used in the Standard Template Library for operators.
1844 ** Improved User Defined Operator Support
1846 In addition to member operators, GDB now supports lookup of operators
1847 defined in a namespace and imported with a `using' directive, operators
1848 defined in the global scope, operators imported implicitly from an
1849 anonymous namespace, and the ADL operators mentioned in the previous
1851 GDB now also supports proper overload resolution for all the previously
1852 mentioned flavors of operators.
1854 ** static const class members
1856 Printing of static const class members that are initialized in the
1857 class definition has been fixed.
1859 * Windows Thread Information Block access.
1861 On Windows targets, GDB now supports displaying the Windows Thread
1862 Information Block (TIB) structure. This structure is visible either
1863 by using the new command `info w32 thread-information-block' or, by
1864 dereferencing the new convenience variable named `$_tlb', a
1865 thread-specific pointer to the TIB. This feature is also supported
1866 when remote debugging using GDBserver.
1868 * Static tracepoints
1870 Static tracepoints are calls in the user program into a tracing
1871 library. One such library is a port of the LTTng kernel tracer to
1872 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1873 When debugging with GDBserver, GDB now supports combining the GDB
1874 tracepoint machinery with such libraries. For example: the user can
1875 use GDB to probe a static tracepoint marker (a call from the user
1876 program into the tracing library) with the new "strace" command (see
1877 "New commands" below). This creates a "static tracepoint" in the
1878 breakpoint list, that can be manipulated with the same feature set
1879 as fast and regular tracepoints. E.g., collect registers, local and
1880 global variables, collect trace state variables, and define
1881 tracepoint conditions. In addition, the user can collect extra
1882 static tracepoint marker specific data, by collecting the new
1883 $_sdata internal variable. When analyzing the trace buffer, you can
1884 inspect $_sdata like any other variable available to GDB. For more
1885 information, see the "Tracepoints" chapter in GDB user manual. New
1886 remote packets have been defined to support static tracepoints, see
1887 the "New remote packets" section below.
1889 * Better reconstruction of tracepoints after disconnected tracing
1891 GDB will attempt to download the original source form of tracepoint
1892 definitions when starting a trace run, and then will upload these
1893 upon reconnection to the target, resulting in a more accurate
1894 reconstruction of the tracepoints that are in use on the target.
1898 You can now exercise direct control over the ways that GDB can
1899 affect your program. For instance, you can disallow the setting of
1900 breakpoints, so that the program can run continuously (assuming
1901 non-stop mode). In addition, the "observer" variable is available
1902 to switch all of the different controls; in observer mode, GDB
1903 cannot affect the target's behavior at all, which is useful for
1904 tasks like diagnosing live systems in the field.
1906 * The new convenience variable $_thread holds the number of the
1909 * New remote packets
1913 Return the address of the Windows Thread Information Block of a given thread.
1917 In response to several of the tracepoint packets, the target may now
1918 also respond with a number of intermediate `qRelocInsn' request
1919 packets before the final result packet, to have GDB handle
1920 relocating an instruction to execute at a different address. This
1921 is particularly useful for stubs that support fast tracepoints. GDB
1922 reports support for this feature in the qSupported packet.
1926 List static tracepoint markers in the target program.
1930 List static tracepoint markers at a given address in the target
1933 qXfer:statictrace:read
1935 Read the static trace data collected (by a `collect $_sdata'
1936 tracepoint action). The remote stub reports support for this packet
1937 to gdb's qSupported query.
1941 Send the current settings of GDB's permission flags.
1945 Send part of the source (textual) form of a tracepoint definition,
1946 which includes location, conditional, and action list.
1948 * The source command now accepts a -s option to force searching for the
1949 script in the source search path even if the script name specifies
1952 * New features in the GDB remote stub, GDBserver
1954 - GDBserver now support tracepoints (including fast tracepoints, and
1955 static tracepoints). The feature is currently supported by the
1956 i386-linux and amd64-linux builds. See the "Tracepoints support
1957 in gdbserver" section in the manual for more information.
1959 GDBserver JIT compiles the tracepoint's conditional agent
1960 expression bytecode into native code whenever possible for low
1961 overhead dynamic tracepoints conditionals. For such tracepoints,
1962 an expression that examines program state is evaluated when the
1963 tracepoint is reached, in order to determine whether to capture
1964 trace data. If the condition is simple and false, processing the
1965 tracepoint finishes very quickly and no data is gathered.
1967 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1968 for static tracepoints support.
1970 - GDBserver now supports x86_64 Windows 64-bit debugging.
1972 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1973 it understands register description.
1975 * The --batch flag now disables pagination and queries.
1977 * X86 general purpose registers
1979 GDB now supports reading/writing byte, word and double-word x86
1980 general purpose registers directly. This means you can use, say,
1981 $ah or $ax to refer, respectively, to the byte register AH and
1982 16-bit word register AX that are actually portions of the 32-bit
1983 register EAX or 64-bit register RAX.
1985 * The `commands' command now accepts a range of breakpoints to modify.
1986 A plain `commands' following a command that creates multiple
1987 breakpoints affects all the breakpoints set by that command. This
1988 applies to breakpoints set by `rbreak', and also applies when a
1989 single `break' command creates multiple breakpoints (e.g.,
1990 breakpoints on overloaded c++ functions).
1992 * The `rbreak' command now accepts a filename specification as part of
1993 its argument, limiting the functions selected by the regex to those
1994 in the specified file.
1996 * Support for remote debugging Windows and SymbianOS shared libraries
1997 from Unix hosts has been improved. Non Windows GDB builds now can
1998 understand target reported file names that follow MS-DOS based file
1999 system semantics, such as file names that include drive letters and
2000 use the backslash character as directory separator. This makes it
2001 possible to transparently use the "set sysroot" and "set
2002 solib-search-path" on Unix hosts to point as host copies of the
2003 target's shared libraries. See the new command "set
2004 target-file-system-kind" described below, and the "Commands to
2005 specify files" section in the user manual for more information.
2009 eval template, expressions...
2010 Convert the values of one or more expressions under the control
2011 of the string template to a command line, and call it.
2013 set target-file-system-kind unix|dos-based|auto
2014 show target-file-system-kind
2015 Set or show the assumed file system kind for target reported file
2018 save breakpoints <filename>
2019 Save all current breakpoint definitions to a file suitable for use
2020 in a later debugging session. To read the saved breakpoint
2021 definitions, use the `source' command.
2023 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2026 info static-tracepoint-markers
2027 Display information about static tracepoint markers in the target.
2029 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2030 Define a static tracepoint by probing a marker at the given
2031 function, line, address, or marker ID.
2035 Enable and disable observer mode.
2037 set may-write-registers on|off
2038 set may-write-memory on|off
2039 set may-insert-breakpoints on|off
2040 set may-insert-tracepoints on|off
2041 set may-insert-fast-tracepoints on|off
2042 set may-interrupt on|off
2043 Set individual permissions for GDB effects on the target. Note that
2044 some of these settings can have undesirable or surprising
2045 consequences, particularly when changed in the middle of a session.
2046 For instance, disabling the writing of memory can prevent
2047 breakpoints from being inserted, cause single-stepping to fail, or
2048 even crash your program, if you disable after breakpoints have been
2049 inserted. However, GDB should not crash.
2051 set record memory-query on|off
2052 show record memory-query
2053 Control whether to stop the inferior if memory changes caused
2054 by an instruction cannot be recorded.
2059 The disassemble command now supports "start,+length" form of two arguments.
2063 ** GDB now provides a new directory location, called the python directory,
2064 where Python scripts written for GDB can be installed. The location
2065 of that directory is <data-directory>/python, where <data-directory>
2066 is the GDB data directory. For more details, see section `Scripting
2067 GDB using Python' in the manual.
2069 ** The GDB Python API now has access to breakpoints, symbols, symbol
2070 tables, program spaces, inferiors, threads and frame's code blocks.
2071 Additionally, GDB Parameters can now be created from the API, and
2072 manipulated via set/show in the CLI.
2074 ** New functions gdb.target_charset, gdb.target_wide_charset,
2075 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2077 ** New exception gdb.GdbError.
2079 ** Pretty-printers are now also looked up in the current program space.
2081 ** Pretty-printers can now be individually enabled and disabled.
2083 ** GDB now looks for names of Python scripts to auto-load in a
2084 special section named `.debug_gdb_scripts', in addition to looking
2085 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2087 * Tracepoint actions were unified with breakpoint commands. In particular,
2088 there are no longer differences in "info break" output for breakpoints and
2089 tracepoints and the "commands" command can be used for both tracepoints and
2090 regular breakpoints.
2094 ARM Symbian arm*-*-symbianelf*
2096 * D language support.
2097 GDB now supports debugging programs written in the D programming
2100 * GDB now supports the extended ptrace interface for PowerPC which is
2101 available since Linux kernel version 2.6.34. This automatically enables
2102 any hardware breakpoints and additional hardware watchpoints available in
2103 the processor. The old ptrace interface exposes just one hardware
2104 watchpoint and no hardware breakpoints.
2106 * GDB is now able to use the Data Value Compare (DVC) register available on
2107 embedded PowerPC processors to implement in hardware simple watchpoint
2108 conditions of the form:
2110 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2112 This works in native GDB running on Linux kernels with the extended ptrace
2113 interface mentioned above.
2115 *** Changes in GDB 7.1
2119 ** Namespace Support
2121 GDB now supports importing of namespaces in C++. This enables the
2122 user to inspect variables from imported namespaces. Support for
2123 namepace aliasing has also been added. So, if a namespace is
2124 aliased in the current scope (e.g. namepace C=A; ) the user can
2125 print variables using the alias (e.g. (gdb) print C::x).
2129 All known bugs relating to the printing of virtual base class were
2130 fixed. It is now possible to call overloaded static methods using a
2135 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2136 and reinterpret_cast<> are now handled by the C++ expression parser.
2140 Xilinx MicroBlaze microblaze-*-*
2145 Xilinx MicroBlaze microblaze
2148 * Multi-program debugging.
2150 GDB now has support for multi-program (a.k.a. multi-executable or
2151 multi-exec) debugging. This allows for debugging multiple inferiors
2152 simultaneously each running a different program under the same GDB
2153 session. See "Debugging Multiple Inferiors and Programs" in the
2154 manual for more information. This implied some user visible changes
2155 in the multi-inferior support. For example, "info inferiors" now
2156 lists inferiors that are not running yet or that have exited
2157 already. See also "New commands" and "New options" below.
2159 * New tracing features
2161 GDB's tracepoint facility now includes several new features:
2163 ** Trace state variables
2165 GDB tracepoints now include support for trace state variables, which
2166 are variables managed by the target agent during a tracing
2167 experiment. They are useful for tracepoints that trigger each
2168 other, so for instance one tracepoint can count hits in a variable,
2169 and then a second tracepoint has a condition that is true when the
2170 count reaches a particular value. Trace state variables share the
2171 $-syntax of GDB convenience variables, and can appear in both
2172 tracepoint actions and condition expressions. Use the "tvariable"
2173 command to create, and "info tvariables" to view; see "Trace State
2174 Variables" in the manual for more detail.
2178 GDB now includes an option for defining fast tracepoints, which
2179 targets may implement more efficiently, such as by installing a jump
2180 into the target agent rather than a trap instruction. The resulting
2181 speedup can be by two orders of magnitude or more, although the
2182 tradeoff is that some program locations on some target architectures
2183 might not allow fast tracepoint installation, for instance if the
2184 instruction to be replaced is shorter than the jump. To request a
2185 fast tracepoint, use the "ftrace" command, with syntax identical to
2186 the regular trace command.
2188 ** Disconnected tracing
2190 It is now possible to detach GDB from the target while it is running
2191 a trace experiment, then reconnect later to see how the experiment
2192 is going. In addition, a new variable disconnected-tracing lets you
2193 tell the target agent whether to continue running a trace if the
2194 connection is lost unexpectedly.
2198 GDB now has the ability to save the trace buffer into a file, and
2199 then use that file as a target, similarly to you can do with
2200 corefiles. You can select trace frames, print data that was
2201 collected in them, and use tstatus to display the state of the
2202 tracing run at the moment that it was saved. To create a trace
2203 file, use "tsave <filename>", and to use it, do "target tfile
2206 ** Circular trace buffer
2208 You can ask the target agent to handle the trace buffer as a
2209 circular buffer, discarding the oldest trace frames to make room for
2210 newer ones, by setting circular-trace-buffer to on. This feature may
2211 not be available for all target agents.
2216 The disassemble command, when invoked with two arguments, now requires
2217 the arguments to be comma-separated.
2220 The info variables command now displays variable definitions. Files
2221 which only declare a variable are not shown.
2224 The source command is now capable of sourcing Python scripts.
2225 This feature is dependent on the debugger being build with Python
2228 Related to this enhancement is also the introduction of a new command
2229 "set script-extension" (see below).
2231 * New commands (for set/show, see "New options" below)
2233 record save [<FILENAME>]
2234 Save a file (in core file format) containing the process record
2235 execution log for replay debugging at a later time.
2237 record restore <FILENAME>
2238 Restore the process record execution log that was saved at an
2239 earlier time, for replay debugging.
2241 add-inferior [-copies <N>] [-exec <FILENAME>]
2244 clone-inferior [-copies <N>] [ID]
2245 Make a new inferior ready to execute the same program another
2246 inferior has loaded.
2251 maint info program-spaces
2252 List the program spaces loaded into GDB.
2254 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2255 show remote interrupt-sequence
2256 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2257 as the sequence to the remote target in order to interrupt the execution.
2258 Ctrl-C is a default. Some system prefers BREAK which is high level of
2259 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2260 Magic SysRq g. It is BREAK signal and character 'g'.
2262 set remote interrupt-on-connect [on | off]
2263 show remote interrupt-on-connect
2264 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2265 remote target when gdb connects to it. This is needed when you debug
2268 set remotebreak [on | off]
2270 Deprecated. Use "set/show remote interrupt-sequence" instead.
2272 tvariable $NAME [ = EXP ]
2273 Create or modify a trace state variable.
2276 List trace state variables and their values.
2278 delete tvariable $NAME ...
2279 Delete one or more trace state variables.
2282 Evaluate the given expressions without collecting anything into the
2283 trace buffer. (Valid in tracepoint actions only.)
2285 ftrace FN / FILE:LINE / *ADDR
2286 Define a fast tracepoint at the given function, line, or address.
2288 * New expression syntax
2290 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2291 GDB now parses 0b101010 identically with 42.
2295 set follow-exec-mode new|same
2296 show follow-exec-mode
2297 Control whether GDB reuses the same inferior across an exec call or
2298 creates a new one. This is useful to be able to restart the old
2299 executable after the inferior having done an exec call.
2301 set default-collect EXPR, ...
2302 show default-collect
2303 Define a list of expressions to be collected at each tracepoint.
2304 This is a useful way to ensure essential items are not overlooked,
2305 such as registers or a critical global variable.
2307 set disconnected-tracing
2308 show disconnected-tracing
2309 If set to 1, the target is instructed to continue tracing if it
2310 loses its connection to GDB. If 0, the target is to stop tracing
2313 set circular-trace-buffer
2314 show circular-trace-buffer
2315 If set to on, the target is instructed to use a circular trace buffer
2316 and discard the oldest trace frames instead of stopping the trace due
2317 to a full trace buffer. If set to off, the trace stops when the buffer
2318 fills up. Some targets may not support this.
2320 set script-extension off|soft|strict
2321 show script-extension
2322 If set to "off", the debugger does not perform any script language
2323 recognition, and all sourced files are assumed to be GDB scripts.
2324 If set to "soft" (the default), files are sourced according to
2325 filename extension, falling back to GDB scripts if the first
2327 If set to "strict", files are sourced according to filename extension.
2329 set ada trust-PAD-over-XVS on|off
2330 show ada trust-PAD-over-XVS
2331 If off, activate a workaround against a bug in the debugging information
2332 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2333 the GCC sources for more information about the GNAT encoding and
2334 PAD types in particular). It is always safe to set this option to
2335 off, but this introduces a slight performance penalty. The default
2338 * Python API Improvements
2340 ** GDB provides the new class gdb.LazyString. This is useful in
2341 some pretty-printing cases. The new method gdb.Value.lazy_string
2342 provides a simple way to create objects of this type.
2344 ** The fields returned by gdb.Type.fields now have an
2345 `is_base_class' attribute.
2347 ** The new method gdb.Type.range returns the range of an array type.
2349 ** The new method gdb.parse_and_eval can be used to parse and
2350 evaluate an expression.
2352 * New remote packets
2355 Define a trace state variable.
2358 Get the current value of a trace state variable.
2361 Set desired tracing behavior upon disconnection.
2364 Set the trace buffer to be linear or circular.
2367 Get data about the tracepoints currently in use.
2371 Process record now works correctly with hardware watchpoints.
2373 Multiple bug fixes have been made to the mips-irix port, making it
2374 much more reliable. In particular:
2375 - Debugging threaded applications is now possible again. Previously,
2376 GDB would hang while starting the program, or while waiting for
2377 the program to stop at a breakpoint.
2378 - Attaching to a running process no longer hangs.
2379 - An error occurring while loading a core file has been fixed.
2380 - Changing the value of the PC register now works again. This fixes
2381 problems observed when using the "jump" command, or when calling
2382 a function from GDB, or even when assigning a new value to $pc.
2383 - With the "finish" and "return" commands, the return value for functions
2384 returning a small array is now correctly printed.
2385 - It is now possible to break on shared library code which gets executed
2386 during a shared library init phase (code executed while executing
2387 their .init section). Previously, the breakpoint would have no effect.
2388 - GDB is now able to backtrace through the signal handler for
2389 non-threaded programs.
2391 PIE (Position Independent Executable) programs debugging is now supported.
2392 This includes debugging execution of PIC (Position Independent Code) shared
2393 libraries although for that, it should be possible to run such libraries as an
2396 *** Changes in GDB 7.0
2398 * GDB now has an interface for JIT compilation. Applications that
2399 dynamically generate code can create symbol files in memory and register
2400 them with GDB. For users, the feature should work transparently, and
2401 for JIT developers, the interface is documented in the GDB manual in the
2402 "JIT Compilation Interface" chapter.
2404 * Tracepoints may now be conditional. The syntax is as for
2405 breakpoints; either an "if" clause appended to the "trace" command,
2406 or the "condition" command is available. GDB sends the condition to
2407 the target for evaluation using the same bytecode format as is used
2408 for tracepoint actions.
2410 * The disassemble command now supports: an optional /r modifier, print the
2411 raw instructions in hex as well as in symbolic form, and an optional /m
2412 modifier to print mixed source+assembly.
2414 * Process record and replay
2416 In a architecture environment that supports ``process record and
2417 replay'', ``process record and replay'' target can record a log of
2418 the process execution, and replay it with both forward and reverse
2421 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2422 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2423 set execution-direction {forward|reverse}, for targets that support
2426 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2427 feature is available with a native GDB running on kernel version
2430 * GDB now has support for multi-byte and wide character sets on the
2431 target. Strings whose character type is wchar_t, char16_t, or
2432 char32_t are now correctly printed. GDB supports wide- and unicode-
2433 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2434 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2435 `printf'. This feature requires iconv to work properly; if your
2436 system does not have a working iconv, GDB can use GNU libiconv. See
2437 the installation instructions for more information.
2439 * GDB now supports automatic retrieval of shared library files from
2440 remote targets. To use this feature, specify a system root that begins
2441 with the `remote:' prefix, either via the `set sysroot' command or via
2442 the `--with-sysroot' configure-time option.
2444 * "info sharedlibrary" now takes an optional regex of libraries to show,
2445 and it now reports if a shared library has no debugging information.
2447 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2448 now complete on file names.
2450 * When completing in expressions, gdb will attempt to limit
2451 completions to allowable structure or union fields, where appropriate.
2452 For instance, consider:
2454 # struct example { int f1; double f2; };
2455 # struct example variable;
2458 If the user types TAB at the end of this command line, the available
2459 completions will be "f1" and "f2".
2461 * Inlined functions are now supported. They show up in backtraces, and
2462 the "step", "next", and "finish" commands handle them automatically.
2464 * GDB now supports the token-splicing (##) and stringification (#)
2465 operators when expanding macros. It also supports variable-arity
2468 * GDB now supports inspecting extra signal information, exported by
2469 the new $_siginfo convenience variable. The feature is currently
2470 implemented on linux ARM, i386 and amd64.
2472 * GDB can now display the VFP floating point registers and NEON vector
2473 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2474 can provide these registers (requires Linux 2.6.30 or later). Remote
2475 and simulator targets may also provide them.
2477 * New remote packets
2480 Search memory for a sequence of bytes.
2483 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2484 operation over reliable transport links. Use of this packet is
2485 controlled by the `set remote noack-packet' command.
2488 Kill the process with the specified process ID. Use this in preference
2489 to `k' when multiprocess protocol extensions are supported.
2492 Obtains additional operating system information
2496 Read or write additional signal information.
2498 * Removed remote protocol undocumented extension
2500 An undocumented extension to the remote protocol's `S' stop reply
2501 packet that permited the stub to pass a process id was removed.
2502 Remote servers should use the `T' stop reply packet instead.
2504 * GDB now supports multiple function calling conventions according to the
2505 DWARF-2 DW_AT_calling_convention function attribute.
2507 * The SH target utilizes the aforementioned change to distinguish between gcc
2508 and Renesas calling convention. It also adds the new CLI commands
2509 `set/show sh calling-convention'.
2511 * GDB can now read compressed debug sections, as produced by GNU gold
2512 with the --compress-debug-sections=zlib flag.
2514 * 64-bit core files are now supported on AIX.
2516 * Thread switching is now supported on Tru64.
2518 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2519 which will be allocated using malloc later in program execution.
2521 * The qXfer:libraries:read remote procotol packet now allows passing a
2522 list of section offsets.
2524 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2525 conditions handling signals delivered during attach or thread creation
2526 have also been fixed.
2528 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2529 From the user's standpoint, all unqualified instances of True and False
2530 are treated as the standard definitions, regardless of context.
2532 * GDB now parses C++ symbol and type names more flexibly. For
2535 template<typename T> class C { };
2538 GDB will now correctly handle all of:
2540 ptype C<char const *>
2541 ptype C<char const*>
2542 ptype C<const char *>
2543 ptype C<const char*>
2545 * New features in the GDB remote stub, gdbserver
2547 - The "--wrapper" command-line argument tells gdbserver to use a
2548 wrapper program to launch programs for debugging.
2550 - On PowerPC and S/390 targets, it is now possible to use a single
2551 gdbserver executable to debug both 32-bit and 64-bit programs.
2552 (This requires gdbserver itself to be built as a 64-bit executable.)
2554 - gdbserver uses the new noack protocol mode for TCP connections to
2555 reduce communications latency, if also supported and enabled in GDB.
2557 - Support for the sparc64-linux-gnu target is now included in
2560 - The amd64-linux build of gdbserver now supports debugging both
2561 32-bit and 64-bit programs.
2563 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2564 now support hardware watchpoints, and will use them automatically
2569 GDB now has support for scripting using Python. Whether this is
2570 available is determined at configure time.
2572 New GDB commands can now be written in Python.
2574 * Ada tasking support
2576 Ada tasks can now be inspected in GDB. The following commands have
2580 Print the list of Ada tasks.
2582 Print detailed information about task number N.
2584 Print the task number of the current task.
2586 Switch the context of debugging to task number N.
2588 * Support for user-defined prefixed commands. The "define" command can
2589 add new commands to existing prefixes, e.g. "target".
2591 * Multi-inferior, multi-process debugging.
2593 GDB now has generalized support for multi-inferior debugging. See
2594 "Debugging Multiple Inferiors" in the manual for more information.
2595 Although availability still depends on target support, the command
2596 set is more uniform now. The GNU/Linux specific multi-forks support
2597 has been migrated to this new framework. This implied some user
2598 visible changes; see "New commands" and also "Removed commands"
2601 * Target descriptions can now describe the target OS ABI. See the
2602 "Target Description Format" section in the user manual for more
2605 * Target descriptions can now describe "compatible" architectures
2606 to indicate that the target can execute applications for a different
2607 architecture in addition to those for the main target architecture.
2608 See the "Target Description Format" section in the user manual for
2611 * Multi-architecture debugging.
2613 GDB now includes general supports for debugging applications on
2614 hybrid systems that use more than one single processor architecture
2615 at the same time. Each such hybrid architecture still requires
2616 specific support to be added. The only hybrid architecture supported
2617 in this version of GDB is the Cell Broadband Engine.
2619 * GDB now supports integrated debugging of Cell/B.E. applications that
2620 use both the PPU and SPU architectures. To enable support for hybrid
2621 Cell/B.E. debugging, you need to configure GDB to support both the
2622 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2623 --enable-targets configure option.
2625 * Non-stop mode debugging.
2627 For some targets, GDB now supports an optional mode of operation in
2628 which you can examine stopped threads while other threads continue
2629 to execute freely. This is referred to as non-stop mode, with the
2630 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2631 section in the user manual for more information.
2633 To be able to support remote non-stop debugging, a remote stub needs
2634 to implement the non-stop mode remote protocol extensions, as
2635 described in the "Remote Non-Stop" section of the user manual. The
2636 GDB remote stub, gdbserver, has been adjusted to support these
2637 extensions on linux targets.
2639 * New commands (for set/show, see "New options" below)
2641 catch syscall [NAME(S) | NUMBER(S)]
2642 Catch system calls. Arguments, which should be names of system
2643 calls or their numbers, mean catch only those syscalls. Without
2644 arguments, every syscall will be caught. When the inferior issues
2645 any of the specified syscalls, GDB will stop and announce the system
2646 call, both when it is called and when its call returns. This
2647 feature is currently available with a native GDB running on the
2648 Linux Kernel, under the following architectures: x86, x86_64,
2649 PowerPC and PowerPC64.
2651 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2653 Search memory for a sequence of bytes.
2655 maint set python print-stack
2656 maint show python print-stack
2657 Show a stack trace when an error is encountered in a Python script.
2660 Invoke CODE by passing it to the Python interpreter.
2665 These allow macros to be defined, undefined, and listed
2669 Show operating system information about processes.
2672 List the inferiors currently under GDB's control.
2675 Switch focus to inferior number NUM.
2678 Detach from inferior number NUM.
2681 Kill inferior number NUM.
2685 set spu stop-on-load
2686 show spu stop-on-load
2687 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2689 set spu auto-flush-cache
2690 show spu auto-flush-cache
2691 Control whether to automatically flush the software-managed cache
2692 during Cell/B.E. debugging.
2694 set sh calling-convention
2695 show sh calling-convention
2696 Control the calling convention used when calling SH target functions.
2699 show debug timestamp
2700 Control display of timestamps with GDB debugging output.
2702 set disassemble-next-line
2703 show disassemble-next-line
2704 Control display of disassembled source lines or instructions when
2707 set remote noack-packet
2708 show remote noack-packet
2709 Set/show the use of remote protocol QStartNoAckMode packet. See above
2710 under "New remote packets."
2712 set remote query-attached-packet
2713 show remote query-attached-packet
2714 Control use of remote protocol `qAttached' (query-attached) packet.
2716 set remote read-siginfo-object
2717 show remote read-siginfo-object
2718 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2721 set remote write-siginfo-object
2722 show remote write-siginfo-object
2723 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2726 set remote reverse-continue
2727 show remote reverse-continue
2728 Control use of remote protocol 'bc' (reverse-continue) packet.
2730 set remote reverse-step
2731 show remote reverse-step
2732 Control use of remote protocol 'bs' (reverse-step) packet.
2734 set displaced-stepping
2735 show displaced-stepping
2736 Control displaced stepping mode. Displaced stepping is a way to
2737 single-step over breakpoints without removing them from the debuggee.
2738 Also known as "out-of-line single-stepping".
2741 show debug displaced
2742 Control display of debugging info for displaced stepping.
2744 maint set internal-error
2745 maint show internal-error
2746 Control what GDB does when an internal error is detected.
2748 maint set internal-warning
2749 maint show internal-warning
2750 Control what GDB does when an internal warning is detected.
2755 Use a wrapper program to launch programs for debugging.
2757 set multiple-symbols (all|ask|cancel)
2758 show multiple-symbols
2759 The value of this variable can be changed to adjust the debugger behavior
2760 when an expression or a breakpoint location contains an ambiguous symbol
2761 name (an overloaded function name, for instance).
2763 set breakpoint always-inserted
2764 show breakpoint always-inserted
2765 Keep breakpoints always inserted in the target, as opposed to inserting
2766 them when resuming the target, and removing them when the target stops.
2767 This option can improve debugger performance on slow remote targets.
2769 set arm fallback-mode (arm|thumb|auto)
2770 show arm fallback-mode
2771 set arm force-mode (arm|thumb|auto)
2773 These commands control how ARM GDB determines whether instructions
2774 are ARM or Thumb. The default for both settings is auto, which uses
2775 the current CPSR value for instructions without symbols; previous
2776 versions of GDB behaved as if "set arm fallback-mode arm".
2778 set disable-randomization
2779 show disable-randomization
2780 Standalone programs run with the virtual address space randomization enabled
2781 by default on some platforms. This option keeps the addresses stable across
2782 multiple debugging sessions.
2786 Control whether other threads are stopped or not when some thread hits
2791 Requests that asynchronous execution is enabled in the target, if available.
2792 In this case, it's possible to resume target in the background, and interact
2793 with GDB while the target is running. "show target-async" displays the
2794 current state of asynchronous execution of the target.
2796 set target-wide-charset
2797 show target-wide-charset
2798 The target-wide-charset is the name of the character set that GDB
2799 uses when printing characters whose type is wchar_t.
2801 set tcp auto-retry (on|off)
2803 set tcp connect-timeout
2804 show tcp connect-timeout
2805 These commands allow GDB to retry failed TCP connections to a remote stub
2806 with a specified timeout period; this is useful if the stub is launched
2807 in parallel with GDB but may not be ready to accept connections immediately.
2809 set libthread-db-search-path
2810 show libthread-db-search-path
2811 Control list of directories which GDB will search for appropriate
2814 set schedule-multiple (on|off)
2815 show schedule-multiple
2816 Allow GDB to resume all threads of all processes or only threads of
2817 the current process.
2821 Use more aggressive caching for accesses to the stack. This improves
2822 performance of remote debugging (particularly backtraces) without
2823 affecting correctness.
2825 set interactive-mode (on|off|auto)
2826 show interactive-mode
2827 Control whether GDB runs in interactive mode (on) or not (off).
2828 When in interactive mode, GDB waits for the user to answer all
2829 queries. Otherwise, GDB does not wait and assumes the default
2830 answer. When set to auto (the default), GDB determines which
2831 mode to use based on the stdin settings.
2836 For program forks, this is replaced by the new more generic `info
2837 inferiors' command. To list checkpoints, you can still use the
2838 `info checkpoints' command, which was an alias for the `info forks'
2842 Replaced by the new `inferior' command. To switch between
2843 checkpoints, you can still use the `restart' command, which was an
2844 alias for the `fork' command.
2847 This is removed, since some targets don't have a notion of
2848 processes. To switch between processes, you can still use the
2849 `inferior' command using GDB's own inferior number.
2852 For program forks, this is replaced by the new more generic `kill
2853 inferior' command. To delete a checkpoint, you can still use the
2854 `delete checkpoint' command, which was an alias for the `delete
2858 For program forks, this is replaced by the new more generic `detach
2859 inferior' command. To detach a checkpoint, you can still use the
2860 `detach checkpoint' command, which was an alias for the `detach
2863 * New native configurations
2865 x86/x86_64 Darwin i[34567]86-*-darwin*
2867 x86_64 MinGW x86_64-*-mingw*
2871 Lattice Mico32 lm32-*
2872 x86 DICOS i[34567]86-*-dicos*
2873 x86_64 DICOS x86_64-*-dicos*
2876 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2877 (mingw32ce) debugging.
2883 These commands were actually not implemented on any target.
2885 *** Changes in GDB 6.8
2887 * New native configurations
2889 NetBSD/hppa hppa*-*netbsd*
2890 Xtensa GNU/Linux xtensa*-*-linux*
2894 NetBSD/hppa hppa*-*-netbsd*
2895 Xtensa GNU/Lunux xtensa*-*-linux*
2897 * Change in command line behavior -- corefiles vs. process ids.
2899 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2900 attaching to process NUMBER fails, GDB no longer attempts to open a
2901 core file named NUMBER. Attaching to a program using the -c option
2902 is no longer supported. Instead, use the '-p' or '--pid' options.
2904 * GDB can now be built as a native debugger for debugging Windows x86
2905 (mingw32) Portable Executable (PE) programs.
2907 * Pending breakpoints no longer change their number when their address
2910 * GDB now supports breakpoints with multiple locations,
2911 including breakpoints on C++ constructors, inside C++ templates,
2912 and in inlined functions.
2914 * GDB's ability to debug optimized code has been improved. GDB more
2915 accurately identifies function bodies and lexical blocks that occupy
2916 more than one contiguous range of addresses.
2918 * Target descriptions can now describe registers for PowerPC.
2920 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2921 registers on PowerPC targets.
2923 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2924 targets even when the libthread_db library is not available.
2926 * The GDB remote stub, gdbserver, now supports the new file transfer
2927 commands (remote put, remote get, and remote delete).
2929 * The GDB remote stub, gdbserver, now supports run and attach in
2930 extended-remote mode.
2932 * hppa*64*-*-hpux11* target broken
2933 The debugger is unable to start a program and fails with the following
2934 error: "Error trying to get information about dynamic linker".
2935 The gdb-6.7 release is also affected.
2937 * GDB now supports the --enable-targets= configure option to allow
2938 building a single GDB executable that supports multiple remote
2939 target architectures.
2941 * GDB now supports debugging C and C++ programs which use the
2942 Decimal Floating Point extension. In addition, the PowerPC target
2943 now has a set of pseudo-registers to inspect decimal float values
2944 stored in two consecutive float registers.
2946 * The -break-insert MI command can optionally create pending
2949 * Improved support for debugging Ada
2950 Many improvements to the Ada language support have been made. These
2952 - Better support for Ada2005 interface types
2953 - Improved handling of arrays and slices in general
2954 - Better support for Taft-amendment types
2955 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2957 - Improved command completion in Ada
2960 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2965 set print frame-arguments (all|scalars|none)
2966 show print frame-arguments
2967 The value of this variable can be changed to control which argument
2968 values should be printed by the debugger when displaying a frame.
2973 Transfer files to and from a remote target, and delete remote files.
2980 Transfer files to and from a remote target, and delete remote files.
2982 * New remote packets
2989 Open, close, read, write, and delete files on the remote system.
2992 Attach to an existing process on the remote system, in extended-remote
2996 Run a new process on the remote system, in extended-remote mode.
2998 *** Changes in GDB 6.7
3000 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3001 bfd, libiberty and opcodes, as revealed by static analysis donated by
3002 Coverity, Inc. (http://scan.coverity.com).
3004 * When looking up multiply-defined global symbols, GDB will now prefer the
3005 symbol definition in the current shared library if it was built using the
3006 -Bsymbolic linker option.
3008 * When the Text User Interface (TUI) is not configured, GDB will now
3009 recognize the -tui command-line option and print a message that the TUI
3012 * The GDB remote stub, gdbserver, now has lower overhead for high
3013 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3015 * GDB for MIPS targets now autodetects whether a remote target provides
3016 32-bit or 64-bit register values.
3018 * Support for C++ member pointers has been improved.
3020 * GDB now understands XML target descriptions, which specify the
3021 target's overall architecture. GDB can read a description from
3022 a local file or over the remote serial protocol.
3024 * Vectors of single-byte data use a new integer type which is not
3025 automatically displayed as character or string data.
3027 * The /s format now works with the print command. It displays
3028 arrays of single-byte integers and pointers to single-byte integers
3031 * Target descriptions can now describe target-specific registers,
3032 for architectures which have implemented the support (currently
3033 only ARM, M68K, and MIPS).
3035 * GDB and the GDB remote stub, gdbserver, now support the XScale
3038 * The GDB remote stub, gdbserver, has been updated to support
3039 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3040 has been rewritten to use the standard GDB remote protocol.
3042 * GDB can now step into C++ functions which are called through thunks.
3044 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3046 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3047 layout. It also supports a TextSeg= and DataSeg= response when only
3048 segment base addresses (rather than offsets) are available.
3050 * The /i format now outputs any trailing branch delay slot instructions
3051 immediately following the last instruction within the count specified.
3053 * The GDB remote protocol "T" stop reply packet now supports a
3054 "library" response. Combined with the new "qXfer:libraries:read"
3055 packet, this response allows GDB to debug shared libraries on targets
3056 where the operating system manages the list of loaded libraries (e.g.
3057 Windows and SymbianOS).
3059 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3060 (DLLs) on Windows and Windows CE targets.
3062 * GDB now supports a faster verification that a .debug file matches its binary
3063 according to its build-id signature, if the signature is present.
3069 Enable or disable hardware flow control (RTS/CTS) on the serial port
3070 when debugging using remote targets.
3072 set mem inaccessible-by-default
3073 show mem inaccessible-by-default
3074 If the target supplies a memory map, for instance via the remote
3075 protocol's "qXfer:memory-map:read" packet, setting this variable
3076 prevents GDB from accessing memory outside the memory map. This
3077 is useful for targets with memory mapped registers or which react
3078 badly to accesses of unmapped address space.
3080 set breakpoint auto-hw
3081 show breakpoint auto-hw
3082 If the target supplies a memory map, for instance via the remote
3083 protocol's "qXfer:memory-map:read" packet, setting this variable
3084 lets GDB use hardware breakpoints automatically for memory regions
3085 where it can not use software breakpoints. This covers both the
3086 "break" command and internal breakpoints used for other commands
3087 including "next" and "finish".
3090 catch exception unhandled
3091 Stop the program execution when Ada exceptions are raised.
3094 Stop the program execution when an Ada assertion failed.
3098 Set an alternate system root for target files. This is a more
3099 general version of "set solib-absolute-prefix", which is now
3100 an alias to "set sysroot".
3103 Provide extended SPU facility status information. This set of
3104 commands is available only when debugging the Cell/B.E. SPU
3107 * New native configurations
3109 OpenBSD/sh sh*-*openbsd*
3112 unset tdesc filename
3114 Use the specified local file as an XML target description, and do
3115 not query the target for its built-in description.
3119 OpenBSD/sh sh*-*-openbsd*
3120 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3121 Toshiba Media Processor mep-elf
3123 * New remote packets
3126 Ignore the specified signals; pass them directly to the debugged program
3127 without stopping other threads or reporting them to GDB.
3129 qXfer:features:read:
3130 Read an XML target description from the target, which describes its
3135 Read or write contents of an spufs file on the target system. These
3136 packets are available only on the Cell/B.E. SPU architecture.
3138 qXfer:libraries:read:
3139 Report the loaded shared libraries. Combined with new "T" packet
3140 response, this packet allows GDB to debug shared libraries on
3141 targets where the operating system manages the list of loaded
3142 libraries (e.g. Windows and SymbianOS).
3146 Support for these obsolete configurations has been removed.
3154 i[34567]86-*-lynxos*
3155 i[34567]86-*-netware*
3156 i[34567]86-*-sco3.2v5*
3157 i[34567]86-*-sco3.2v4*
3159 i[34567]86-*-sysv4.2*
3162 i[34567]86-*-unixware2*
3163 i[34567]86-*-unixware*
3172 * Other removed features
3179 Various m68k-only ROM monitors.
3186 Various Renesas ROM monitors and debugging interfaces for SH and
3191 Support for a Macraigor serial interface to on-chip debugging.
3192 GDB does not directly support the newer parallel or USB
3197 A debug information format. The predecessor to DWARF 2 and
3198 DWARF 3, which are still supported.
3200 Support for the HP aCC compiler on HP-UX/PA-RISC
3202 SOM-encapsulated symbolic debugging information, automatic
3203 invocation of pxdb, and the aCC custom C++ ABI. This does not
3204 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3205 with aCC can still be debugged on an assembly level.
3207 MIPS ".pdr" sections
3209 A MIPS-specific format used to describe stack frame layout
3210 in debugging information.
3214 GDB could work with an older version of Guile to debug
3215 the interpreter and Scheme programs running in it.
3217 set mips stack-arg-size
3218 set mips saved-gpreg-size
3220 Use "set mips abi" to control parameter passing for MIPS.
3222 *** Changes in GDB 6.6
3227 Cell Broadband Engine SPU spu-elf
3229 * GDB can now be configured as a cross-debugger targeting native Windows
3230 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3231 running on a Windows system over TCP/IP to debug Windows programs.
3233 * The GDB remote stub, gdbserver, has been updated to support Windows and
3234 Cygwin debugging. Both single-threaded and multi-threaded programs are
3237 * The "set trust-readonly-sections" command works again. This command was
3238 broken in GDB 6.3, 6.4, and 6.5.
3240 * The "load" command now supports writing to flash memory, if the remote
3241 stub provides the required support.
3243 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3244 longer requires symbolic debug information (e.g. DWARF-2).
3249 unset substitute-path
3250 show substitute-path
3251 Manage a list of substitution rules that GDB uses to rewrite the name
3252 of the directories where the sources are located. This can be useful
3253 for instance when the sources were moved to a different location
3254 between compilation and debugging.
3258 Print each CLI command as it is executed. Each command is prefixed with
3259 a number of `+' symbols representing the nesting depth.
3260 The source command now has a `-v' option to enable the same feature.
3264 The ARM Demon monitor support (RDP protocol, "target rdp").
3266 Kernel Object Display, an embedded debugging feature which only worked with
3267 an obsolete version of Cisco IOS.
3269 The 'set download-write-size' and 'show download-write-size' commands.
3271 * New remote packets
3274 Tell a stub about GDB client features, and request remote target features.
3275 The first feature implemented is PacketSize, which allows the target to
3276 specify the size of packets it can handle - to minimize the number of
3277 packets required and improve performance when connected to a remote
3281 Fetch an OS auxilliary vector from the remote stub. This packet is a
3282 more efficient replacement for qPart:auxv:read.
3284 qXfer:memory-map:read:
3285 Fetch a memory map from the remote stub, including information about
3286 RAM, ROM, and flash memory devices.
3291 Erase and program a flash memory device.
3293 * Removed remote packets
3296 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3297 used it, and only gdbserver implemented it.
3299 *** Changes in GDB 6.5
3303 Renesas M32C/M16C m32c-elf
3305 Morpho Technologies ms1 ms1-elf
3309 init-if-undefined Initialize a convenience variable, but
3310 only if it doesn't already have a value.
3312 The following commands are presently only implemented for native GNU/Linux:
3314 checkpoint Save a snapshot of the program state.
3316 restart <n> Return the program state to a
3317 previously saved state.
3319 info checkpoints List currently saved checkpoints.
3321 delete-checkpoint <n> Delete a previously saved checkpoint.
3323 set|show detach-on-fork Tell gdb whether to detach from a newly
3324 forked process, or to keep debugging it.
3326 info forks List forks of the user program that
3327 are available to be debugged.
3329 fork <n> Switch to debugging one of several
3330 forks of the user program that are
3331 available to be debugged.
3333 delete-fork <n> Delete a fork from the list of forks
3334 that are available to be debugged (and
3335 kill the forked process).
3337 detach-fork <n> Delete a fork from the list of forks
3338 that are available to be debugged (and
3339 allow the process to continue).
3343 Morpho Technologies ms2 ms1-elf
3345 * Improved Windows host support
3347 GDB now builds as a cross debugger hosted on i686-mingw32, including
3348 native console support, and remote communications using either
3349 network sockets or serial ports.
3351 * Improved Modula-2 language support
3353 GDB can now print most types in the Modula-2 syntax. This includes:
3354 basic types, set types, record types, enumerated types, range types,
3355 pointer types and ARRAY types. Procedure var parameters are correctly
3356 printed and hexadecimal addresses and character constants are also
3357 written in the Modula-2 syntax. Best results can be obtained by using
3358 GNU Modula-2 together with the -gdwarf-2 command line option.
3362 The ARM rdi-share module.
3364 The Netware NLM debug server.
3366 *** Changes in GDB 6.4
3368 * New native configurations
3370 OpenBSD/arm arm*-*-openbsd*
3371 OpenBSD/mips64 mips64-*-openbsd*
3375 Morpho Technologies ms1 ms1-elf
3377 * New command line options
3379 --batch-silent As for --batch, but totally silent.
3380 --return-child-result The debugger will exist with the same value
3381 the child (debugged) program exited with.
3382 --eval-command COMMAND, -ex COMMAND
3383 Execute a single GDB CLI command. This may be
3384 specified multiple times and in conjunction
3385 with the --command (-x) option.
3387 * Deprecated commands removed
3389 The following commands, that were deprecated in 2000, have been
3393 set|show arm disassembly-flavor set|show arm disassembler
3394 othernames set arm disassembler
3395 set|show remotedebug set|show debug remote
3396 set|show archdebug set|show debug arch
3397 set|show eventdebug set|show debug event
3400 * New BSD user-level threads support
3402 It is now possible to debug programs using the user-level threads
3403 library on OpenBSD and FreeBSD. Currently supported (target)
3406 FreeBSD/amd64 x86_64-*-freebsd*
3407 FreeBSD/i386 i386-*-freebsd*
3408 OpenBSD/i386 i386-*-openbsd*
3410 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3411 are not yet supported.
3413 * New support for Matsushita MN10300 w/sim added
3414 (Work in progress). mn10300-elf.
3416 * REMOVED configurations and files
3418 VxWorks and the XDR protocol *-*-vxworks
3419 Motorola MCORE mcore-*-*
3420 National Semiconductor NS32000 ns32k-*-*
3422 * New "set print array-indexes" command
3424 After turning this setting "on", GDB prints the index of each element
3425 when displaying arrays. The default is "off" to preserve the previous
3428 * VAX floating point support
3430 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3432 * User-defined command support
3434 In addition to using $arg0..$arg9 for argument passing, it is now possible
3435 to use $argc to determine now many arguments have been passed. See the
3436 section on user-defined commands in the user manual for more information.
3438 *** Changes in GDB 6.3:
3440 * New command line option
3442 GDB now accepts -l followed by a number to set the timeout for remote
3445 * GDB works with GCC -feliminate-dwarf2-dups
3447 GDB now supports a more compact representation of DWARF-2 debug
3448 information using DW_FORM_ref_addr references. These are produced
3449 by GCC with the option -feliminate-dwarf2-dups and also by some
3450 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3451 to use -feliminate-dwarf2-dups.
3453 * Internationalization
3455 When supported by the host system, GDB will be built with
3456 internationalization (libintl). The task of marking up the sources is
3457 continued, we're looking forward to our first translation.
3461 Initial support for debugging programs compiled with the GNAT
3462 implementation of the Ada programming language has been integrated
3463 into GDB. In this release, support is limited to expression evaluation.
3465 * New native configurations
3467 GNU/Linux/m32r m32r-*-linux-gnu
3471 GDB's remote protocol now includes support for the 'p' packet. This
3472 packet is used to fetch individual registers from a remote inferior.
3474 * END-OF-LIFE registers[] compatibility module
3476 GDB's internal register infrastructure has been completely rewritten.
3477 The new infrastructure making possible the implementation of key new
3478 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3481 GDB 6.3 will be the last release to include the the registers[]
3482 compatibility module that allowed out-of-date configurations to
3483 continue to work. This change directly impacts the following
3493 powerpc bdm protocol
3495 Unless there is activity to revive these configurations, they will be
3496 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3498 * OBSOLETE configurations and files
3500 Configurations that have been declared obsolete in this release have
3501 been commented out. Unless there is activity to revive these
3502 configurations, the next release of GDB will have their sources
3503 permanently REMOVED.
3512 *** Changes in GDB 6.2.1:
3514 * MIPS `break main; run' gave an heuristic-fence-post warning
3516 When attempting to run even a simple program, a warning about
3517 heuristic-fence-post being hit would be reported. This problem has
3520 * MIPS IRIX 'long double' crashed GDB
3522 When examining a long double variable, GDB would get a segmentation
3523 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3524 IRIX long double values).
3528 A bug in the VAX stack code was causing problems with the "next"
3529 command. This problem has been fixed.
3531 *** Changes in GDB 6.2:
3533 * Fix for ``many threads''
3535 On GNU/Linux systems that use the NPTL threads library, a program
3536 rapidly creating and deleting threads would confuse GDB leading to the
3539 ptrace: No such process.
3540 thread_db_get_info: cannot get thread info: generic error
3542 This problem has been fixed.
3544 * "-async" and "-noasync" options removed.
3546 Support for the broken "-noasync" option has been removed (it caused
3549 * New ``start'' command.
3551 This command runs the program until the begining of the main procedure.
3553 * New BSD Kernel Data Access Library (libkvm) interface
3555 Using ``target kvm'' it is now possible to debug kernel core dumps and
3556 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3557 platforms. Currently supported (native-only) configurations are:
3559 FreeBSD/amd64 x86_64-*-freebsd*
3560 FreeBSD/i386 i?86-*-freebsd*
3561 NetBSD/i386 i?86-*-netbsd*
3562 NetBSD/m68k m68*-*-netbsd*
3563 NetBSD/sparc sparc-*-netbsd*
3564 OpenBSD/amd64 x86_64-*-openbsd*
3565 OpenBSD/i386 i?86-*-openbsd*
3566 OpenBSD/m68k m68*-openbsd*
3567 OpenBSD/sparc sparc-*-openbsd*
3569 * Signal trampoline code overhauled
3571 Many generic problems with GDB's signal handling code have been fixed.
3572 These include: backtraces through non-contiguous stacks; recognition
3573 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3574 call; backtrace through a signal trampoline; step into and out of
3575 signal handlers; and single-stepping in the signal trampoline.
3577 Please note that kernel bugs are a limiting factor here. These
3578 features have been shown to work on an s390 GNU/Linux system that
3579 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3581 * Cygwin support for DWARF 2 added.
3583 * New native configurations
3585 GNU/Linux/hppa hppa*-*-linux*
3586 OpenBSD/hppa hppa*-*-openbsd*
3587 OpenBSD/m68k m68*-*-openbsd*
3588 OpenBSD/m88k m88*-*-openbsd*
3589 OpenBSD/powerpc powerpc-*-openbsd*
3590 NetBSD/vax vax-*-netbsd*
3591 OpenBSD/vax vax-*-openbsd*
3593 * END-OF-LIFE frame compatibility module
3595 GDB's internal frame infrastructure has been completely rewritten.
3596 The new infrastructure making it possible to support key new features
3597 including DWARF 2 Call Frame Information. To aid in the task of
3598 migrating old configurations to this new infrastructure, a
3599 compatibility module, that allowed old configurations to continue to
3600 work, was also included.
3602 GDB 6.2 will be the last release to include this frame compatibility
3603 module. This change directly impacts the following configurations:
3613 Unless there is activity to revive these configurations, they will be
3614 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3616 * REMOVED configurations and files
3618 Sun 3, running SunOS 3 m68*-*-sunos3*
3619 Sun 3, running SunOS 4 m68*-*-sunos4*
3620 Sun 2, running SunOS 3 m68000-*-sunos3*
3621 Sun 2, running SunOS 4 m68000-*-sunos4*
3622 Motorola 680x0 running LynxOS m68*-*-lynxos*
3623 AT&T 3b1/Unix pc m68*-att-*
3624 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3625 decstation mips-dec-* mips-little-*
3626 riscos mips-*-riscos* mips-*-sysv*
3627 sonymips mips-sony-*
3628 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3630 *** Changes in GDB 6.1.1:
3632 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3634 The TUI (Text-mode User Interface) is now built as part of a default
3635 GDB configuration. It is enabled by either selecting the TUI with the
3636 command line option "-i=tui" or by running the separate "gdbtui"
3637 program. For more information on the TUI, see the manual "Debugging
3640 * Pending breakpoint support (also included in GDB 6.1)
3642 Support has been added to allow you to specify breakpoints in shared
3643 libraries that have not yet been loaded. If a breakpoint location
3644 cannot be found, and the "breakpoint pending" option is set to auto,
3645 GDB queries you if you wish to make the breakpoint pending on a future
3646 shared-library load. If and when GDB resolves the breakpoint symbol,
3647 the pending breakpoint is removed as one or more regular breakpoints
3650 Pending breakpoints are very useful for GCJ Java debugging.
3652 * Fixed ISO-C build problems
3654 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3655 non ISO-C code that stopped them being built using a more strict ISO-C
3656 compiler (e.g., IBM's C compiler).
3658 * Fixed build problem on IRIX 5
3660 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3661 wasn't able to compile compile on an IRIX 5 system.
3663 * Added execute permission to gdb/gdbserver/configure
3665 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3666 permission. This bug would cause configure to fail on a number of
3667 systems (Solaris, IRIX). Ref: server/519.
3669 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3671 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3672 has been updated to use constant array sizes.
3674 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3676 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3677 its generated DWARF Call Frame Info. This encoding was causing GDB to
3678 panic, that panic has been fixed. Ref: gdb/1628.
3680 * Fixed a problem when examining parameters in shared library code.
3682 When examining parameters in optimized shared library code generated
3683 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3684 not available''. GDB now correctly displays the variable's value.
3686 *** Changes in GDB 6.1:
3688 * Removed --with-mmalloc
3690 Support for the mmalloc memory manager has been removed, as it
3691 conflicted with the internal gdb byte cache.
3693 * Changes in AMD64 configurations
3695 The AMD64 target now includes the %cs and %ss registers. As a result
3696 the AMD64 remote protocol has changed; this affects the floating-point
3697 and SSE registers. If you rely on those registers for your debugging,
3698 you should upgrade gdbserver on the remote side.
3700 * Revised SPARC target
3702 The SPARC target has been completely revised, incorporating the
3703 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3704 support for LynxOS and SunOS 4 has been dropped. Calling functions
3705 from within GDB on operating systems with a non-executable stack
3706 (Solaris, OpenBSD) now works.
3710 GDB has a new C++ demangler which does a better job on the mangled
3711 names generated by current versions of g++. It also runs faster, so
3712 with this and other changes gdb should now start faster on large C++
3715 * DWARF 2 Location Expressions
3717 GDB support for location expressions has been extended to support function
3718 arguments and frame bases. Older versions of GDB could crash when they
3721 * C++ nested types and namespaces
3723 GDB's support for nested types and namespaces in C++ has been
3724 improved, especially if you use the DWARF 2 debugging format. (This
3725 is the default for recent versions of GCC on most platforms.)
3726 Specifically, if you have a class "Inner" defined within a class or
3727 namespace "Outer", then GDB realizes that the class's name is
3728 "Outer::Inner", not simply "Inner". This should greatly reduce the
3729 frequency of complaints about not finding RTTI symbols. In addition,
3730 if you are stopped at inside of a function defined within a namespace,
3731 GDB modifies its name lookup accordingly.
3733 * New native configurations
3735 NetBSD/amd64 x86_64-*-netbsd*
3736 OpenBSD/amd64 x86_64-*-openbsd*
3737 OpenBSD/alpha alpha*-*-openbsd*
3738 OpenBSD/sparc sparc-*-openbsd*
3739 OpenBSD/sparc64 sparc64-*-openbsd*
3741 * New debugging protocols
3743 M32R with SDI protocol m32r-*-elf*
3745 * "set prompt-escape-char" command deleted.
3747 The command "set prompt-escape-char" has been deleted. This command,
3748 and its very obscure effet on GDB's prompt, was never documented,
3749 tested, nor mentioned in the NEWS file.
3751 * OBSOLETE configurations and files
3753 Configurations that have been declared obsolete in this release have
3754 been commented out. Unless there is activity to revive these
3755 configurations, the next release of GDB will have their sources
3756 permanently REMOVED.
3758 Sun 3, running SunOS 3 m68*-*-sunos3*
3759 Sun 3, running SunOS 4 m68*-*-sunos4*
3760 Sun 2, running SunOS 3 m68000-*-sunos3*
3761 Sun 2, running SunOS 4 m68000-*-sunos4*
3762 Motorola 680x0 running LynxOS m68*-*-lynxos*
3763 AT&T 3b1/Unix pc m68*-att-*
3764 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3765 decstation mips-dec-* mips-little-*
3766 riscos mips-*-riscos* mips-*-sysv*
3767 sonymips mips-sony-*
3768 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3770 * REMOVED configurations and files
3772 SGI Irix-4.x mips-sgi-irix4 or iris4
3773 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3774 Z8000 simulator z8k-zilog-none or z8ksim
3775 Matsushita MN10200 w/simulator mn10200-*-*
3776 H8/500 simulator h8500-hitachi-hms or h8500hms
3777 HP/PA running BSD hppa*-*-bsd*
3778 HP/PA running OSF/1 hppa*-*-osf*
3779 HP/PA Pro target hppa*-*-pro*
3780 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3781 386BSD i[3456]86-*-bsd*
3782 Sequent family i[3456]86-sequent-sysv4*
3783 i[3456]86-sequent-sysv*
3784 i[3456]86-sequent-bsd*
3785 SPARC running LynxOS sparc-*-lynxos*
3786 SPARC running SunOS 4 sparc-*-sunos4*
3787 Tsqware Sparclet sparclet-*-*
3788 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3790 *** Changes in GDB 6.0:
3794 Support for debugging the Objective-C programming language has been
3795 integrated into GDB.
3797 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3799 DWARF 2's Call Frame Information makes available compiler generated
3800 information that more exactly describes the program's run-time stack.
3801 By using this information, GDB is able to provide more robust stack
3804 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3805 have been updated to use a new backtrace mechanism which includes
3806 DWARF 2 CFI support.
3810 GDB's remote protocol has been extended to include support for hosted
3811 file I/O (where the remote target uses GDB's file system). See GDB's
3812 remote protocol documentation for details.
3814 * All targets using the new architecture framework.
3816 All of GDB's targets have been updated to use the new internal
3817 architecture framework. The way is now open for future GDB releases
3818 to include cross-architecture native debugging support (i386 on amd64,
3821 * GNU/Linux's Thread Local Storage (TLS)
3823 GDB now includes support for for the GNU/Linux implementation of
3824 per-thread variables.
3826 * GNU/Linux's Native POSIX Thread Library (NPTL)
3828 GDB's thread code has been updated to work with either the new
3829 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3831 * Separate debug info.
3833 GDB, in conjunction with BINUTILS, now supports a mechanism for
3834 automatically loading debug information from a separate file. Instead
3835 of shipping full debug and non-debug versions of system libraries,
3836 system integrators can now instead ship just the stripped libraries
3837 and optional debug files.
3839 * DWARF 2 Location Expressions
3841 DWARF 2 Location Expressions allow the compiler to more completely
3842 describe the location of variables (even in optimized code) to the
3845 GDB now includes preliminary support for location expressions (support
3846 for DW_OP_piece is still missing).
3850 A number of long standing bugs that caused GDB to die while starting a
3851 Java application have been fixed. GDB's Java support is now
3852 considered "useable".
3854 * GNU/Linux support for fork, vfork, and exec.
3856 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3857 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3860 * GDB supports logging output to a file
3862 There are two new commands, "set logging" and "show logging", which can be
3863 used to capture GDB's output to a file.
3865 * The meaning of "detach" has changed for gdbserver
3867 The "detach" command will now resume the application, as documented. To
3868 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3871 * d10v, m68hc11 `regs' command deprecated
3873 The `info registers' command has been updated so that it displays the
3874 registers using a format identical to the old `regs' command.
3878 A new command, "maint set profile on/off", has been added. This command can
3879 be used to enable or disable profiling while running GDB, to profile a
3880 session or a set of commands. In addition there is a new configure switch,
3881 "--enable-profiling", which will cause GDB to be compiled with profiling
3882 data, for more informative profiling results.
3884 * Default MI syntax changed to "mi2".
3886 The default MI (machine interface) syntax, enabled by the command line
3887 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3888 "mi1", can be enabled by specifying the option "-i=mi1".
3890 Support for the original "mi0" syntax (included in GDB 5.0) has been
3893 Fix for gdb/192: removed extraneous space when displaying frame level.
3894 Fix for gdb/672: update changelist is now output in mi list format.
3895 Fix for gdb/702: a -var-assign that updates the value now shows up
3896 in a subsequent -var-update.
3898 * New native configurations.
3900 FreeBSD/amd64 x86_64-*-freebsd*
3902 * Multi-arched targets.
3904 HP/PA HPUX11 hppa*-*-hpux*
3905 Renesas M32R/D w/simulator m32r-*-elf*
3907 * OBSOLETE configurations and files
3909 Configurations that have been declared obsolete in this release have
3910 been commented out. Unless there is activity to revive these
3911 configurations, the next release of GDB will have their sources
3912 permanently REMOVED.
3914 Z8000 simulator z8k-zilog-none or z8ksim
3915 Matsushita MN10200 w/simulator mn10200-*-*
3916 H8/500 simulator h8500-hitachi-hms or h8500hms
3917 HP/PA running BSD hppa*-*-bsd*
3918 HP/PA running OSF/1 hppa*-*-osf*
3919 HP/PA Pro target hppa*-*-pro*
3920 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3921 Sequent family i[3456]86-sequent-sysv4*
3922 i[3456]86-sequent-sysv*
3923 i[3456]86-sequent-bsd*
3924 Tsqware Sparclet sparclet-*-*
3925 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3927 * REMOVED configurations and files
3930 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3931 IBM AIX PS/2 i[3456]86-*-aix
3932 i386 running Mach 3.0 i[3456]86-*-mach3*
3933 i386 running Mach i[3456]86-*-mach*
3934 i386 running OSF/1 i[3456]86-*osf1mk*
3935 HP/Apollo 68k Family m68*-apollo*-sysv*,
3937 m68*-hp-bsd*, m68*-hp-hpux*
3938 Argonaut Risc Chip (ARC) arc-*-*
3939 Mitsubishi D30V d30v-*-*
3940 Fujitsu FR30 fr30-*-elf*
3941 OS/9000 i[34]86-*-os9k
3942 I960 with MON960 i960-*-coff
3944 * MIPS $fp behavior changed
3946 The convenience variable $fp, for the MIPS, now consistently returns
3947 the address of the current frame's base. Previously, depending on the
3948 context, $fp could refer to either $sp or the current frame's base
3949 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3950 The GNU Source-Level Debugger''.
3952 *** Changes in GDB 5.3:
3954 * GNU/Linux shared library multi-threaded performance improved.
3956 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3957 `/proc', in preference to `ptrace' for memory reads. This may result
3958 in an improvement in the start-up time of multi-threaded, shared
3959 library applications when run under GDB. One GDB user writes: ``loads
3960 shared libs like mad''.
3962 * ``gdbserver'' now supports multi-threaded applications on some targets
3964 Support for debugging multi-threaded applications which use
3965 the GNU/Linux LinuxThreads package has been added for
3966 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3967 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3969 * GDB now supports C/C++ preprocessor macros.
3971 GDB now expands preprocessor macro invocations in C/C++ expressions,
3972 and provides various commands for showing macro definitions and how
3975 The new command `macro expand EXPRESSION' expands any macro
3976 invocations in expression, and shows the result.
3978 The new command `show macro MACRO-NAME' shows the definition of the
3979 macro named MACRO-NAME, and where it was defined.
3981 Most compilers don't include information about macros in the debugging
3982 information by default. In GCC 3.1, for example, you need to compile
3983 your program with the options `-gdwarf-2 -g3'. If the macro
3984 information is present in the executable, GDB will read it.
3986 * Multi-arched targets.
3988 DEC Alpha (partial) alpha*-*-*
3989 DEC VAX (partial) vax-*-*
3991 National Semiconductor NS32000 (partial) ns32k-*-*
3992 Motorola 68000 (partial) m68k-*-*
3993 Motorola MCORE mcore-*-*
3997 Fujitsu FRV architecture added by Red Hat frv*-*-*
4000 * New native configurations
4002 Alpha NetBSD alpha*-*-netbsd*
4003 SH NetBSD sh*-*-netbsdelf*
4004 MIPS NetBSD mips*-*-netbsd*
4005 UltraSPARC NetBSD sparc64-*-netbsd*
4007 * OBSOLETE configurations and files
4009 Configurations that have been declared obsolete in this release have
4010 been commented out. Unless there is activity to revive these
4011 configurations, the next release of GDB will have their sources
4012 permanently REMOVED.
4014 Mitsubishi D30V d30v-*-*
4015 OS/9000 i[34]86-*-os9k
4016 IBM AIX PS/2 i[3456]86-*-aix
4017 Fujitsu FR30 fr30-*-elf*
4018 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4019 Argonaut Risc Chip (ARC) arc-*-*
4020 i386 running Mach 3.0 i[3456]86-*-mach3*
4021 i386 running Mach i[3456]86-*-mach*
4022 i386 running OSF/1 i[3456]86-*osf1mk*
4023 HP/Apollo 68k Family m68*-apollo*-sysv*,
4025 m68*-hp-bsd*, m68*-hp-hpux*
4026 I960 with MON960 i960-*-coff
4028 * OBSOLETE languages
4030 CHILL, a Pascal like language used by telecommunications companies.
4032 * REMOVED configurations and files
4034 AMD 29k family via UDI a29k-amd-udi, udi29k
4035 A29K VxWorks a29k-*-vxworks
4036 AMD 29000 embedded, using EBMON a29k-none-none
4037 AMD 29000 embedded with COFF a29k-none-coff
4038 AMD 29000 embedded with a.out a29k-none-aout
4040 testsuite/gdb.hp/gdb.threads-hp/ directory
4042 * New command "set max-user-call-depth <nnn>"
4044 This command allows the user to limit the call depth of user-defined
4045 commands. The default is 1024.
4047 * Changes in FreeBSD/i386 native debugging.
4049 Support for the "generate-core-file" has been added.
4051 * New commands "dump", "append", and "restore".
4053 These commands allow data to be copied from target memory
4054 to a bfd-format or binary file (dump and append), and back
4055 from a file into memory (restore).
4057 * Improved "next/step" support on multi-processor Alpha Tru64.
4059 The previous single-step mechanism could cause unpredictable problems,
4060 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4061 of a software single-step mechanism prevents this.
4063 *** Changes in GDB 5.2.1:
4071 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4072 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4073 Fix, by Joel Brobecker imported from mainline.
4075 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4076 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4077 Fix, by Fred Fish, imported from mainline.
4079 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4080 Surprisingly enough, it works now.
4081 By Michal Ludvig, imported from mainline.
4083 i386 hardware watchpoint support:
4084 avoid misses on second run for some targets.
4085 By Pierre Muller, imported from mainline.
4087 *** Changes in GDB 5.2:
4089 * New command "set trust-readonly-sections on[off]".
4091 This command is a hint that tells gdb that read-only sections
4092 really are read-only (ie. that their contents will not change).
4093 In this mode, gdb will go to the object file rather than the
4094 target to read memory from read-only sections (such as ".text").
4095 This can be a significant performance improvement on some
4096 (notably embedded) targets.
4098 * New command "generate-core-file" (or "gcore").
4100 This new gdb command allows the user to drop a core file of the child
4101 process state at any time. So far it's been implemented only for
4102 GNU/Linux and Solaris, but should be relatively easily ported to other
4103 hosts. Argument is core file name (defaults to core.<pid>).
4105 * New command line option
4107 GDB now accepts --pid or -p followed by a process id.
4109 * Change in command line behavior -- corefiles vs. process ids.
4111 There is a subtle behavior in the way in which GDB handles
4112 command line arguments. The first non-flag argument is always
4113 a program to debug, but the second non-flag argument may either
4114 be a corefile or a process id. Previously, GDB would attempt to
4115 open the second argument as a corefile, and if that failed, would
4116 issue a superfluous error message and then attempt to attach it as
4117 a process. Now, if the second argument begins with a non-digit,
4118 it will be treated as a corefile. If it begins with a digit,
4119 GDB will attempt to attach it as a process, and if no such process
4120 is found, will then attempt to open it as a corefile.
4122 * Changes in ARM configurations.
4124 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4125 configuration is fully multi-arch.
4127 * New native configurations
4129 ARM NetBSD arm*-*-netbsd*
4130 x86 OpenBSD i[3456]86-*-openbsd*
4131 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4132 Sparc64 running FreeBSD sparc64-*-freebsd*
4136 Sanyo XStormy16 xstormy16-elf
4138 * OBSOLETE configurations and files
4140 Configurations that have been declared obsolete in this release have
4141 been commented out. Unless there is activity to revive these
4142 configurations, the next release of GDB will have their sources
4143 permanently REMOVED.
4145 AMD 29k family via UDI a29k-amd-udi, udi29k
4146 A29K VxWorks a29k-*-vxworks
4147 AMD 29000 embedded, using EBMON a29k-none-none
4148 AMD 29000 embedded with COFF a29k-none-coff
4149 AMD 29000 embedded with a.out a29k-none-aout
4151 testsuite/gdb.hp/gdb.threads-hp/ directory
4153 * REMOVED configurations and files
4155 TI TMS320C80 tic80-*-*
4157 PowerPC Solaris powerpcle-*-solaris*
4158 PowerPC Windows NT powerpcle-*-cygwin32
4159 PowerPC Netware powerpc-*-netware*
4160 Harris/CXUX m88k m88*-harris-cxux*
4161 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4162 ns32k-utek-sysv* ns32k-utek-*
4163 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4164 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4165 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4166 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4167 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4169 * Changes to command line processing
4171 The new `--args' feature can be used to specify command-line arguments
4172 for the inferior from gdb's command line.
4174 * Changes to key bindings
4176 There is a new `operate-and-get-next' function bound to `C-o'.
4178 *** Changes in GDB 5.1.1
4180 Fix compile problem on DJGPP.
4182 Fix a problem with floating-point registers on the i386 being
4185 Fix to stop GDB crashing on .debug_str debug info.
4187 Numerous documentation fixes.
4189 Numerous testsuite fixes.
4191 *** Changes in GDB 5.1:
4193 * New native configurations
4195 Alpha FreeBSD alpha*-*-freebsd*
4196 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4197 MIPS GNU/Linux mips*-*-linux*
4198 MIPS SGI Irix 6.x mips*-sgi-irix6*
4199 ia64 AIX ia64-*-aix*
4200 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4204 Motorola 68HC11 and 68HC12 m68hc11-elf
4206 UltraSparc running GNU/Linux sparc64-*-linux*
4208 * OBSOLETE configurations and files
4210 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4211 Harris/CXUX m88k m88*-harris-cxux*
4212 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4213 ns32k-utek-sysv* ns32k-utek-*
4214 TI TMS320C80 tic80-*-*
4216 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4217 PowerPC Solaris powerpcle-*-solaris*
4218 PowerPC Windows NT powerpcle-*-cygwin32
4219 PowerPC Netware powerpc-*-netware*
4220 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4221 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4222 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4223 Apple Macintosh (MPW) host N/A
4225 stuff.c (Program to stuff files into a specially prepared space in kdb)
4226 kdb-start.c (Main loop for the standalone kernel debugger)
4228 Configurations that have been declared obsolete in this release have
4229 been commented out. Unless there is activity to revive these
4230 configurations, the next release of GDB will have their sources
4231 permanently REMOVED.
4233 * REMOVED configurations and files
4235 Altos 3068 m68*-altos-*
4236 Convex c1-*-*, c2-*-*
4238 ARM RISCix arm-*-* (as host)
4242 * GDB has been converted to ISO C.
4244 GDB's source code has been converted to ISO C. In particular, the
4245 sources are fully protoized, and rely on standard headers being
4250 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4252 * The MI enabled by default.
4254 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4255 revised and enabled by default. Packages which use GDB as a debugging
4256 engine behind a UI or another front end are encouraged to switch to
4257 using the GDB/MI interface, instead of the old annotations interface
4258 which is now deprecated.
4260 * Support for debugging Pascal programs.
4262 GDB now includes support for debugging Pascal programs. The following
4263 main features are supported:
4265 - Pascal-specific data types such as sets;
4267 - automatic recognition of Pascal sources based on file-name
4270 - Pascal-style display of data types, variables, and functions;
4272 - a Pascal expression parser.
4274 However, some important features are not yet supported.
4276 - Pascal string operations are not supported at all;
4278 - there are some problems with boolean types;
4280 - Pascal type hexadecimal constants are not supported
4281 because they conflict with the internal variables format;
4283 - support for Pascal objects and classes is not full yet;
4285 - unlike Pascal, GDB is case-sensitive for symbol names.
4287 * Changes in completion.
4289 Commands such as `shell', `run' and `set args', which pass arguments
4290 to inferior programs, now complete on file names, similar to what
4291 users expect at the shell prompt.
4293 Commands which accept locations, such as `disassemble', `print',
4294 `breakpoint', `until', etc. now complete on filenames as well as
4295 program symbols. Thus, if you type "break foob TAB", and the source
4296 files linked into the programs include `foobar.c', that file name will
4297 be one of the candidates for completion. However, file names are not
4298 considered for completion after you typed a colon that delimits a file
4299 name from a name of a function in that file, as in "break foo.c:bar".
4301 `set demangle-style' completes on available demangling styles.
4303 * New platform-independent commands:
4305 It is now possible to define a post-hook for a command as well as a
4306 hook that runs before the command. For more details, see the
4307 documentation of `hookpost' in the GDB manual.
4309 * Changes in GNU/Linux native debugging.
4311 Support for debugging multi-threaded programs has been completely
4312 revised for all platforms except m68k and sparc. You can now debug as
4313 many threads as your system allows you to have.
4315 Attach/detach is supported for multi-threaded programs.
4317 Support for SSE registers was added for x86. This doesn't work for
4318 multi-threaded programs though.
4320 * Changes in MIPS configurations.
4322 Multi-arch support is enabled for all MIPS configurations.
4324 GDB can now be built as native debugger on SGI Irix 6.x systems for
4325 debugging n32 executables. (Debugging 64-bit executables is not yet
4328 * Unified support for hardware watchpoints in all x86 configurations.
4330 Most (if not all) native x86 configurations support hardware-assisted
4331 breakpoints and watchpoints in a unified manner. This support
4332 implements debug register sharing between watchpoints, which allows to
4333 put a virtually infinite number of watchpoints on the same address,
4334 and also supports watching regions up to 16 bytes with several debug
4337 The new maintenance command `maintenance show-debug-regs' toggles
4338 debugging print-outs in functions that insert, remove, and test
4339 watchpoints and hardware breakpoints.
4341 * Changes in the DJGPP native configuration.
4343 New command ``info dos sysinfo'' displays assorted information about
4344 the CPU, OS, memory, and DPMI server.
4346 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4347 display information about segment descriptors stored in GDT, LDT, and
4350 New commands ``info dos pde'' and ``info dos pte'' display entries
4351 from Page Directory and Page Tables (for now works with CWSDPMI only).
4352 New command ``info dos address-pte'' displays the Page Table entry for
4353 a given linear address.
4355 GDB can now pass command lines longer than 126 characters to the
4356 program being debugged (requires an update to the libdbg.a library
4357 which is part of the DJGPP development kit).
4359 DWARF2 debug info is now supported.
4361 It is now possible to `step' and `next' through calls to `longjmp'.
4363 * Changes in documentation.
4365 All GDB documentation was converted to GFDL, the GNU Free
4366 Documentation License.
4368 Tracepoints-related commands are now fully documented in the GDB
4371 TUI, the Text-mode User Interface, is now documented in the manual.
4373 Tracepoints-related commands are now fully documented in the GDB
4376 The "GDB Internals" manual now has an index. It also includes
4377 documentation of `ui_out' functions, GDB coding standards, x86
4378 hardware watchpoints, and memory region attributes.
4380 * GDB's version number moved to ``version.in''
4382 The Makefile variable VERSION has been replaced by the file
4383 ``version.in''. People creating GDB distributions should update the
4384 contents of this file.
4388 GUD support is now a standard part of the EMACS distribution.
4390 *** Changes in GDB 5.0:
4392 * Improved support for debugging FP programs on x86 targets
4394 Unified and much-improved support for debugging floating-point
4395 programs on all x86 targets. In particular, ``info float'' now
4396 displays the FP registers in the same format on all x86 targets, with
4397 greater level of detail.
4399 * Improvements and bugfixes in hardware-assisted watchpoints
4401 It is now possible to watch array elements, struct members, and
4402 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4403 on x86 targets no longer erroneously trigger when the address is
4406 * Improvements in the native DJGPP version of GDB
4408 The distribution now includes all the scripts and auxiliary files
4409 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4410 machines ``out of the box''.
4412 The DJGPP version can now debug programs that use signals. It is
4413 possible to catch signals that happened in the debuggee, deliver
4414 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4415 would kill the program being debugged.) Programs that hook hardware
4416 interrupts (keyboard, timer, etc.) can also be debugged.
4418 It is now possible to debug DJGPP programs that redirect their
4419 standard handles or switch them to raw (as opposed to cooked) mode, or
4420 even close them. The command ``run < foo > bar'' works as expected,
4421 and ``info terminal'' reports useful information about the debuggee's
4422 terminal, including raw/cooked mode, redirection, etc.
4424 The DJGPP version now uses termios functions for console I/O, which
4425 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4428 DOS-style file names with drive letters are now fully supported by
4431 It is now possible to debug DJGPP programs that switch their working
4432 directory. It is also possible to rerun the debuggee any number of
4433 times without restarting GDB; thus, you can use the same setup,
4434 breakpoints, etc. for many debugging sessions.
4436 * New native configurations
4438 ARM GNU/Linux arm*-*-linux*
4439 PowerPC GNU/Linux powerpc-*-linux*
4443 Motorola MCore mcore-*-*
4444 x86 VxWorks i[3456]86-*-vxworks*
4445 PowerPC VxWorks powerpc-*-vxworks*
4446 TI TMS320C80 tic80-*-*
4448 * OBSOLETE configurations
4450 Altos 3068 m68*-altos-*
4451 Convex c1-*-*, c2-*-*
4453 ARM RISCix arm-*-* (as host)
4456 Configurations that have been declared obsolete will be commented out,
4457 but the code will be left in place. If there is no activity to revive
4458 these configurations before the next release of GDB, the sources will
4459 be permanently REMOVED.
4461 * Gould support removed
4463 Support for the Gould PowerNode and NP1 has been removed.
4465 * New features for SVR4
4467 On SVR4 native platforms (such as Solaris), if you attach to a process
4468 without first loading a symbol file, GDB will now attempt to locate and
4469 load symbols from the running process's executable file.
4471 * Many C++ enhancements
4473 C++ support has been greatly improved. Overload resolution now works properly
4474 in almost all cases. RTTI support is on the way.
4476 * Remote targets can connect to a sub-program
4478 A popen(3) style serial-device has been added. This device starts a
4479 sub-process (such as a stand-alone simulator) and then communicates
4480 with that. The sub-program to run is specified using the syntax
4481 ``|<program> <args>'' vis:
4483 (gdb) set remotedebug 1
4484 (gdb) target extended-remote |mn10300-elf-sim program-args
4486 * MIPS 64 remote protocol
4488 A long standing bug in the mips64 remote protocol where by GDB
4489 expected certain 32 bit registers (ex SR) to be transfered as 32
4490 instead of 64 bits has been fixed.
4492 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4493 added to provide backward compatibility with older versions of GDB.
4495 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4497 The command ``set remotebinarydownload'' command has been replaced by
4498 ``set remote X-packet''. Other commands in ``set remote'' family
4499 include ``set remote P-packet''.
4501 * Breakpoint commands accept ranges.
4503 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4504 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4505 ``tracepoint passcount'' also accepts a range of tracepoints.
4507 * ``apropos'' command added.
4509 The ``apropos'' command searches through command names and
4510 documentation strings, printing out matches, making it much easier to
4511 try to find a command that does what you are looking for.
4515 A new machine oriented interface (MI) has been added to GDB. This
4516 interface is designed for debug environments running GDB as a separate
4517 process. This is part of the long term libGDB project. See the
4518 "GDB/MI" chapter of the GDB manual for further information. It can be
4519 enabled by configuring with:
4521 .../configure --enable-gdbmi
4523 *** Changes in GDB-4.18:
4525 * New native configurations
4527 HP-UX 10.20 hppa*-*-hpux10.20
4528 HP-UX 11.x hppa*-*-hpux11.0*
4529 M68K GNU/Linux m68*-*-linux*
4533 Fujitsu FR30 fr30-*-elf*
4534 Intel StrongARM strongarm-*-*
4535 Mitsubishi D30V d30v-*-*
4537 * OBSOLETE configurations
4539 Gould PowerNode, NP1 np1-*-*, pn-*-*
4541 Configurations that have been declared obsolete will be commented out,
4542 but the code will be left in place. If there is no activity to revive
4543 these configurations before the next release of GDB, the sources will
4544 be permanently REMOVED.
4548 As a compatibility experiment, GDB's source files buildsym.h and
4549 buildsym.c have been converted to pure standard C, no longer
4550 containing any K&R compatibility code. We believe that all systems in
4551 use today either come with a standard C compiler, or have a GCC port
4552 available. If this is not true, please report the affected
4553 configuration to bug-gdb@gnu.org immediately. See the README file for
4554 information about getting a standard C compiler if you don't have one
4559 GDB now uses readline 2.2.
4561 * set extension-language
4563 You can now control the mapping between filename extensions and source
4564 languages by using the `set extension-language' command. For instance,
4565 you can ask GDB to treat .c files as C++ by saying
4566 set extension-language .c c++
4567 The command `info extensions' lists all of the recognized extensions
4568 and their associated languages.
4570 * Setting processor type for PowerPC and RS/6000
4572 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4573 you can use the `set processor' command to specify what variant of the
4574 PowerPC family you are debugging. The command
4578 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4579 following PowerPC and RS6000 variants:
4581 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4582 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4584 403GC IBM PowerPC 403GC
4585 505 Motorola PowerPC 505
4586 860 Motorola PowerPC 860 or 850
4587 601 Motorola PowerPC 601
4588 602 Motorola PowerPC 602
4589 603 Motorola/IBM PowerPC 603 or 603e
4590 604 Motorola PowerPC 604 or 604e
4591 750 Motorola/IBM PowerPC 750 or 750
4593 At the moment, this command just tells GDB what to name the
4594 special-purpose processor registers. Since almost all the affected
4595 registers are inaccessible to user-level programs, this command is
4596 only useful for remote debugging in its present form.
4600 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4601 more extensive support for HP-UX. Added features include shared
4602 library support, kernel threads and hardware watchpoints for 11.00,
4603 support for HP's ANSI C and C++ compilers, and a compatibility mode
4604 for xdb and dbx commands.
4608 HP's donation includes the new concept of catchpoints, which is a
4609 generalization of the old catch command. On HP-UX, it is now possible
4610 to catch exec, fork, and vfork, as well as library loading.
4612 This means that the existing catch command has changed; its first
4613 argument now specifies the type of catch to be set up. See the
4614 output of "help catch" for a list of catchpoint types.
4616 * Debugging across forks
4618 On HP-UX, you can choose which process to debug when a fork() happens
4623 HP has donated a curses-based terminal user interface (TUI). To get
4624 it, build with --enable-tui. Although this can be enabled for any
4625 configuration, at present it only works for native HP debugging.
4627 * GDB remote protocol additions
4629 A new protocol packet 'X' that writes binary data is now available.
4630 Default behavior is to try 'X', then drop back to 'M' if the stub
4631 fails to respond. The settable variable `remotebinarydownload'
4632 allows explicit control over the use of 'X'.
4634 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4635 full 64-bit address. The command
4637 set remoteaddresssize 32
4639 can be used to revert to the old behaviour. For existing remote stubs
4640 the change should not be noticed, as the additional address information
4643 In order to assist in debugging stubs, you may use the maintenance
4644 command `packet' to send any text string to the stub. For instance,
4646 maint packet heythere
4648 sends the packet "$heythere#<checksum>". Note that it is very easy to
4649 disrupt a debugging session by sending the wrong packet at the wrong
4652 The compare-sections command allows you to compare section data on the
4653 target to what is in the executable file without uploading or
4654 downloading, by comparing CRC checksums.
4656 * Tracing can collect general expressions
4658 You may now collect general expressions at tracepoints. This requires
4659 further additions to the target-side stub; see tracepoint.c and
4660 doc/agentexpr.texi for further details.
4662 * mask-address variable for Mips
4664 For Mips targets, you may control the zeroing of the upper 32 bits of
4665 a 64-bit address by entering `set mask-address on'. This is mainly
4666 of interest to users of embedded R4xxx and R5xxx processors.
4668 * Higher serial baud rates
4670 GDB's serial code now allows you to specify baud rates 57600, 115200,
4671 230400, and 460800 baud. (Note that your host system may not be able
4672 to achieve all of these rates.)
4676 The i960 configuration now includes an initial implementation of a
4677 builtin simulator, contributed by Jim Wilson.
4680 *** Changes in GDB-4.17:
4682 * New native configurations
4684 Alpha GNU/Linux alpha*-*-linux*
4685 Unixware 2.x i[3456]86-unixware2*
4686 Irix 6.x mips*-sgi-irix6*
4687 PowerPC GNU/Linux powerpc-*-linux*
4688 PowerPC Solaris powerpcle-*-solaris*
4689 Sparc GNU/Linux sparc-*-linux*
4690 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4694 Argonaut Risc Chip (ARC) arc-*-*
4695 Hitachi H8/300S h8300*-*-*
4696 Matsushita MN10200 w/simulator mn10200-*-*
4697 Matsushita MN10300 w/simulator mn10300-*-*
4698 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4699 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4700 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4701 Mitsubishi D10V w/simulator d10v-*-*
4702 Mitsubishi M32R/D w/simulator m32r-*-elf*
4703 Tsqware Sparclet sparclet-*-*
4704 NEC V850 w/simulator v850-*-*
4706 * New debugging protocols
4708 ARM with RDI protocol arm*-*-*
4709 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4710 DDB and LSI variants of PMON protocol mips*-*-*
4711 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4712 PowerPC with SDS protocol powerpc{,le}-*-eabi
4713 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4717 All configurations can now understand and use the DWARF 2 debugging
4718 format. The choice is automatic, if the symbol file contains DWARF 2
4723 GDB now includes basic Java language support. This support is
4724 only useful with Java compilers that produce native machine code.
4726 * solib-absolute-prefix and solib-search-path
4728 For SunOS and SVR4 shared libraries, you may now set the prefix for
4729 loading absolute shared library symbol files, and the search path for
4730 locating non-absolute shared library symbol files.
4732 * Live range splitting
4734 GDB can now effectively debug code for which GCC has performed live
4735 range splitting as part of its optimization. See gdb/doc/LRS for
4736 more details on the expected format of the stabs information.
4740 GDB's support for the GNU Hurd, including thread debugging, has been
4741 updated to work with current versions of the Hurd.
4745 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4746 instruction set. ARM GDB automatically detects when Thumb
4747 instructions are in use, and adjusts disassembly and backtracing
4752 GDB's MIPS target configurations now handle the MIP16 16-bit
4757 GDB now includes support for overlays; if an executable has been
4758 linked such that multiple sections are based at the same address, GDB
4759 will decide which section to use for symbolic info. You can choose to
4760 control the decision manually, using overlay commands, or implement
4761 additional target-side support and use "overlay load-target" to bring
4762 in the overlay mapping. Do "help overlay" for more detail.
4766 The command "info symbol <address>" displays information about
4767 the symbol at the specified address.
4771 The standard remote protocol now includes an extension that allows
4772 asynchronous collection and display of trace data. This requires
4773 extensive support in the target-side debugging stub. Tracing mode
4774 includes a new interaction mode in GDB and new commands: see the
4775 file tracepoint.c for more details.
4779 Configurations for embedded MIPS now include a simulator contributed
4780 by Cygnus Solutions. The simulator supports the instruction sets
4781 of most MIPS variants.
4785 Sparc configurations may now include the ERC32 simulator contributed
4786 by the European Space Agency. The simulator is not built into
4787 Sparc targets by default; configure with --enable-sim to include it.
4791 For target configurations that may include multiple variants of a
4792 basic architecture (such as MIPS and SH), you may now set the
4793 architecture explicitly. "set arch" sets, "info arch" lists
4794 the possible architectures.
4796 *** Changes in GDB-4.16:
4798 * New native configurations
4800 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4801 M68K NetBSD m68k-*-netbsd*
4802 PowerPC AIX 4.x powerpc-*-aix*
4803 PowerPC MacOS powerpc-*-macos*
4804 PowerPC Windows NT powerpcle-*-cygwin32
4805 RS/6000 AIX 4.x rs6000-*-aix4*
4809 ARM with RDP protocol arm-*-*
4810 I960 with MON960 i960-*-coff
4811 MIPS VxWorks mips*-*-vxworks*
4812 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4813 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4815 Matra Sparclet sparclet-*-*
4819 The powerpc-eabi configuration now includes the PSIM simulator,
4820 contributed by Andrew Cagney, with assistance from Mike Meissner.
4821 PSIM is a very elaborate model of the PowerPC, including not only
4822 basic instruction set execution, but also details of execution unit
4823 performance and I/O hardware. See sim/ppc/README for more details.
4827 GDB now works with Solaris 2.5.
4829 * Windows 95/NT native
4831 GDB will now work as a native debugger on Windows 95 and Windows NT.
4832 To build it from source, you must use the "gnu-win32" environment,
4833 which uses a DLL to emulate enough of Unix to run the GNU tools.
4834 Further information, binaries, and sources are available at
4835 ftp.cygnus.com, under pub/gnu-win32.
4837 * dont-repeat command
4839 If a user-defined command includes the command `dont-repeat', then the
4840 command will not be repeated if the user just types return. This is
4841 useful if the command is time-consuming to run, so that accidental
4842 extra keystrokes don't run the same command many times.
4844 * Send break instead of ^C
4846 The standard remote protocol now includes an option to send a break
4847 rather than a ^C to the target in order to interrupt it. By default,
4848 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4850 * Remote protocol timeout
4852 The standard remote protocol includes a new variable `remotetimeout'
4853 that allows you to set the number of seconds before GDB gives up trying
4854 to read from the target. The default value is 2.
4856 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4858 By default GDB will automatically keep track of objects as they are
4859 loaded and unloaded by the dynamic linker. By using the command `set
4860 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4861 when shared library events occur, thus allowing you to set breakpoints
4862 in shared libraries which are explicitly loaded by the inferior.
4864 Note this feature does not work on hpux8. On hpux9 you must link
4865 /usr/lib/end.o into your program. This feature should work
4866 automatically on hpux10.
4868 * Irix 5.x hardware watchpoint support
4870 Irix 5 configurations now support the use of hardware watchpoints.
4872 * Mips protocol "SYN garbage limit"
4874 When debugging a Mips target using the `target mips' protocol, you
4875 may set the number of characters that GDB will ignore by setting
4876 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4877 every character. The default value is 1050.
4879 * Recording and replaying remote debug sessions
4881 If you set `remotelogfile' to the name of a file, gdb will write to it
4882 a recording of a remote debug session. This recording may then be
4883 replayed back to gdb using "gdbreplay". See gdbserver/README for
4884 details. This is useful when you have a problem with GDB while doing
4885 remote debugging; you can make a recording of the session and send it
4886 to someone else, who can then recreate the problem.
4888 * Speedups for remote debugging
4890 GDB includes speedups for downloading and stepping MIPS systems using
4891 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4892 and more efficient S-record downloading.
4894 * Memory use reductions and statistics collection
4896 GDB now uses less memory and reports statistics about memory usage.
4897 Try the `maint print statistics' command, for example.
4899 *** Changes in GDB-4.15:
4901 * Psymtabs for XCOFF
4903 The symbol reader for AIX GDB now uses partial symbol tables. This
4904 can greatly improve startup time, especially for large executables.
4906 * Remote targets use caching
4908 Remote targets now use a data cache to speed up communication with the
4909 remote side. The data cache could lead to incorrect results because
4910 it doesn't know about volatile variables, thus making it impossible to
4911 debug targets which use memory mapped I/O devices. `set remotecache
4912 off' turns the the data cache off.
4914 * Remote targets may have threads
4916 The standard remote protocol now includes support for multiple threads
4917 in the target system, using new protocol commands 'H' and 'T'. See
4918 gdb/remote.c for details.
4922 If GDB is configured with `--enable-netrom', then it will include
4923 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4924 acts as though it is a bank of ROM on the target board, but you can
4925 write into it over the network. GDB's support consists only of
4926 support for fast loading into the emulated ROM; to debug, you must use
4927 another protocol, such as standard remote protocol. The usual
4928 sequence is something like
4930 target nrom <netrom-hostname>
4932 target remote <netrom-hostname>:1235
4936 GDB now includes support for the Apple Macintosh, as a host only. It
4937 may be run as either an MPW tool or as a standalone application, and
4938 it can debug through the serial port. All the usual GDB commands are
4939 available, but to the target command, you must supply "serial" as the
4940 device type instead of "/dev/ttyXX". See mpw-README in the main
4941 directory for more information on how to build. The MPW configuration
4942 scripts */mpw-config.in support only a few targets, and only the
4943 mips-idt-ecoff target has been tested.
4947 GDB configuration now uses autoconf. This is not user-visible,
4948 but does simplify configuration and building.
4952 GDB now supports hpux10.
4954 *** Changes in GDB-4.14:
4956 * New native configurations
4958 x86 FreeBSD i[345]86-*-freebsd
4959 x86 NetBSD i[345]86-*-netbsd
4960 NS32k NetBSD ns32k-*-netbsd
4961 Sparc NetBSD sparc-*-netbsd
4965 A29K VxWorks a29k-*-vxworks
4966 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4967 CPU32 EST-300 emulator m68*-*-est*
4968 PowerPC ELF powerpc-*-elf
4971 * Alpha OSF/1 support for procfs
4973 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4974 possible to attach to running processes. As the mounting of the /proc
4975 filesystem is optional on the Alpha, GDB automatically determines
4976 the availability of /proc during startup. This can lead to problems
4977 if /proc is unmounted after GDB has been started.
4979 * Arguments to user-defined commands
4981 User commands may accept up to 10 arguments separated by whitespace.
4982 Arguments are accessed within the user command via $arg0..$arg9. A
4985 print $arg0 + $arg1 + $arg2
4987 To execute the command use:
4990 Defines the command "adder" which prints the sum of its three arguments.
4991 Note the arguments are text substitutions, so they may reference variables,
4992 use complex expressions, or even perform inferior function calls.
4994 * New `if' and `while' commands
4996 This makes it possible to write more sophisticated user-defined
4997 commands. Both commands take a single argument, which is the
4998 expression to evaluate, and must be followed by the commands to
4999 execute, one per line, if the expression is nonzero, the list being
5000 terminated by the word `end'. The `if' command list may include an
5001 `else' word, which causes the following commands to be executed only
5002 if the expression is zero.
5004 * Fortran source language mode
5006 GDB now includes partial support for Fortran 77. It will recognize
5007 Fortran programs and can evaluate a subset of Fortran expressions, but
5008 variables and functions may not be handled correctly. GDB will work
5009 with G77, but does not yet know much about symbols emitted by other
5012 * Better HPUX support
5014 Most debugging facilities now work on dynamic executables for HPPAs
5015 running hpux9 or later. You can attach to running dynamically linked
5016 processes, but by default the dynamic libraries will be read-only, so
5017 for instance you won't be able to put breakpoints in them. To change
5018 that behavior do the following before running the program:
5024 This will cause the libraries to be mapped private and read-write.
5025 To revert to the normal behavior, do this:
5031 You cannot set breakpoints or examine data in the library until after
5032 the library is loaded if the function/data symbols do not have
5035 GDB can now also read debug symbols produced by the HP C compiler on
5036 HPPAs (sorry, no C++, Fortran or 68k support).
5038 * Target byte order now dynamically selectable
5040 You can choose which byte order to use with a target system, via the
5041 commands "set endian big" and "set endian little", and you can see the
5042 current setting by using "show endian". You can also give the command
5043 "set endian auto", in which case GDB will use the byte order
5044 associated with the executable. Currently, only embedded MIPS
5045 configurations support dynamic selection of target byte order.
5047 * New DOS host serial code
5049 This version uses DPMI interrupts to handle buffered I/O, so you
5050 no longer need to run asynctsr when debugging boards connected to
5053 *** Changes in GDB-4.13:
5055 * New "complete" command
5057 This lists all the possible completions for the rest of the line, if it
5058 were to be given as a command itself. This is intended for use by emacs.
5060 * Trailing space optional in prompt
5062 "set prompt" no longer adds a space for you after the prompt you set. This
5063 allows you to set a prompt which ends in a space or one that does not.
5065 * Breakpoint hit counts
5067 "info break" now displays a count of the number of times the breakpoint
5068 has been hit. This is especially useful in conjunction with "ignore"; you
5069 can ignore a large number of breakpoint hits, look at the breakpoint info
5070 to see how many times the breakpoint was hit, then run again, ignoring one
5071 less than that number, and this will get you quickly to the last hit of
5074 * Ability to stop printing at NULL character
5076 "set print null-stop" will cause GDB to stop printing the characters of
5077 an array when the first NULL is encountered. This is useful when large
5078 arrays actually contain only short strings.
5080 * Shared library breakpoints
5082 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5083 breakpoints in shared libraries before the executable is run.
5085 * Hardware watchpoints
5087 There is a new hardware breakpoint for the watch command for sparclite
5088 targets. See gdb/sparclite/hw_breakpoint.note.
5090 Hardware watchpoints are also now supported under GNU/Linux.
5094 Annotations have been added. These are for use with graphical interfaces,
5095 and are still experimental. Currently only gdba.el uses these.
5097 * Improved Irix 5 support
5099 GDB now works properly with Irix 5.2.
5101 * Improved HPPA support
5103 GDB now works properly with the latest GCC and GAS.
5105 * New native configurations
5107 Sequent PTX4 i[34]86-sequent-ptx4
5108 HPPA running OSF/1 hppa*-*-osf*
5109 Atari TT running SVR4 m68*-*-sysv4*
5110 RS/6000 LynxOS rs6000-*-lynxos*
5114 OS/9000 i[34]86-*-os9k
5115 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5118 * Hitachi SH7000 and E7000-PC ICE support
5120 There is now support for communicating with the Hitachi E7000-PC ICE.
5121 This is available automatically when GDB is configured for the SH.
5125 As usual, a variety of small fixes and improvements, both generic
5126 and configuration-specific. See the ChangeLog for more detail.
5128 *** Changes in GDB-4.12:
5130 * Irix 5 is now supported
5134 GDB-4.12 on the HPPA has a number of changes which make it unable
5135 to debug the output from the currently released versions of GCC and
5136 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5137 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5138 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5141 *** Changes in GDB-4.11:
5143 * User visible changes:
5147 The "set remotedebug" option is now consistent between the mips remote
5148 target, remote targets using the gdb-specific protocol, UDI (AMD's
5149 debug protocol for the 29k) and the 88k bug monitor. It is now an
5150 integer specifying a debug level (normally 0 or 1, but 2 means more
5151 debugging info for the mips target).
5153 * DEC Alpha native support
5155 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5156 debug info, but GDB works fairly well with the DEC compiler and should
5157 work with a future GCC release. See the README file for a few
5158 Alpha-specific notes.
5160 * Preliminary thread implementation
5162 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5164 * LynxOS native and target support for 386
5166 This release has been hosted on LynxOS 2.2, and also can be configured
5167 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5170 * Improvements in C++ mangling/demangling.
5172 This release has much better g++ debugging, specifically in name
5173 mangling/demangling, virtual function calls, print virtual table,
5174 call methods, ...etc.
5176 *** Changes in GDB-4.10:
5178 * User visible changes:
5180 Remote debugging using the GDB-specific (`target remote') protocol now
5181 supports the `load' command. This is only useful if you have some
5182 other way of getting the stub to the target system, and you can put it
5183 somewhere in memory where it won't get clobbered by the download.
5185 Filename completion now works.
5187 When run under emacs mode, the "info line" command now causes the
5188 arrow to point to the line specified. Also, "info line" prints
5189 addresses in symbolic form (as well as hex).
5191 All vxworks based targets now support a user settable option, called
5192 vxworks-timeout. This option represents the number of seconds gdb
5193 should wait for responses to rpc's. You might want to use this if
5194 your vxworks target is, perhaps, a slow software simulator or happens
5195 to be on the far side of a thin network line.
5199 This release contains support for using a DEC alpha as a GDB host for
5200 cross debugging. Native alpha debugging is not supported yet.
5203 *** Changes in GDB-4.9:
5207 This is the first GDB release which is accompanied by a matching testsuite.
5208 The testsuite requires installation of dejagnu, which should be available
5209 via ftp from most sites that carry GNU software.
5213 'Cfront' style demangling has had its name changed to 'ARM' style, to
5214 emphasize that it was written from the specifications in the C++ Annotated
5215 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5216 disclaimers, it still generated too much confusion with users attempting to
5217 use gdb with AT&T cfront.
5221 GDB now uses a standard remote interface to a simulator library.
5222 So far, the library contains simulators for the Zilog Z8001/2, the
5223 Hitachi H8/300, H8/500 and Super-H.
5225 * New targets supported
5227 H8/300 simulator h8300-hitachi-hms or h8300hms
5228 H8/500 simulator h8500-hitachi-hms or h8500hms
5229 SH simulator sh-hitachi-hms or sh
5230 Z8000 simulator z8k-zilog-none or z8ksim
5231 IDT MIPS board over serial line mips-idt-ecoff
5233 Cross-debugging to GO32 targets is supported. It requires a custom
5234 version of the i386-stub.c module which is integrated with the
5235 GO32 memory extender.
5237 * New remote protocols
5239 MIPS remote debugging protocol.
5241 * New source languages supported
5243 This version includes preliminary support for Chill, a Pascal like language
5244 used by telecommunications companies. Chill support is also being integrated
5245 into the GNU compiler, but we don't know when it will be publically available.
5248 *** Changes in GDB-4.8:
5250 * HP Precision Architecture supported
5252 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5253 version of this support was available as a set of patches from the
5254 University of Utah. GDB does not support debugging of programs
5255 compiled with the HP compiler, because HP will not document their file
5256 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5257 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5259 Many problems in the preliminary version have been fixed.
5261 * Faster and better demangling
5263 We have improved template demangling and fixed numerous bugs in the GNU style
5264 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5265 character types (wchar_t) are now supported. Demangling of each symbol is now
5266 only done once, and is cached when the symbol table for a file is read in.
5267 This results in a small increase in memory usage for C programs, a moderate
5268 increase in memory usage for C++ programs, and a fantastic speedup in
5271 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5272 from the specifications in the Annotated Reference Manual, which AT&T's
5273 compiler does not actually implement.
5275 * G++ multiple inheritance compiler problem
5277 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5278 inheritance lattices was reworked to properly discover ambiguities. We
5279 recently found an example which causes this new algorithm to fail in a
5280 very subtle way, producing bad debug information for those classes.
5281 The file 'gcc.patch' (in this directory) can be applied to gcc to
5282 circumvent the problem. A future GCC release will contain a complete
5285 The previous G++ debug info problem (mentioned below for the gdb-4.7
5286 release) is fixed in gcc version 2.3.2.
5288 * Improved configure script
5290 The `configure' script will now attempt to guess your system type if
5291 you don't supply a host system type. The old scheme of supplying a
5292 host system triplet is preferable over using this. All the magic is
5293 done in the new `config.guess' script. Examine it for details.
5295 We have also brought our configure script much more in line with the FSF's
5296 version. It now supports the --with-xxx options. In particular,
5297 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5298 The resulting GDB will not be able to read arbitrary object file formats --
5299 only the format ``expected'' to be used on the configured target system.
5300 We hope to make this the default in a future release.
5302 * Documentation improvements
5304 There's new internal documentation on how to modify GDB, and how to
5305 produce clean changes to the code. We implore people to read it
5306 before submitting changes.
5308 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5309 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5310 `info' files are also provided. To build `info' files from scratch,
5311 you will need the latest `makeinfo' release, which will be available in
5312 a future texinfo-X.Y release.
5314 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5315 We're not sure exactly which versions have this problem, but it has
5316 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5317 or better. If that isn't possible, there is a patch in
5318 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5319 around this problem.
5323 GDB now supports array constants that can be used in expressions typed in by
5324 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5325 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5328 The new directory `gdb/sparclite' contains a program that demonstrates
5329 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5331 * New native hosts supported
5333 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5334 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5336 * New targets supported
5338 AMD 29k family via UDI a29k-amd-udi or udi29k
5340 * New file formats supported
5342 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5343 HPUX core files, and SCO 3.2v2 core files.
5347 Attaching to processes now works again; thanks for the many bug reports.
5349 We have also stomped on a bunch of core dumps caused by
5350 printf_filtered("%s") problems.
5352 We eliminated a copyright problem on the rpc and ptrace header files
5353 for VxWorks, which was discovered at the last minute during the 4.7
5354 release. You should now be able to build a VxWorks GDB.
5356 You can now interrupt gdb while an attached process is running. This
5357 will cause the attached process to stop, and give control back to GDB.
5359 We fixed problems caused by using too many file descriptors
5360 for reading symbols from object files and libraries. This was
5361 especially a problem for programs that used many (~100) shared
5364 The `step' command now only enters a subroutine if there is line number
5365 information for the subroutine. Otherwise it acts like the `next'
5366 command. Previously, `step' would enter subroutines if there was
5367 any debugging information about the routine. This avoids problems
5368 when using `cc -g1' on MIPS machines.
5370 * Internal improvements
5372 GDB's internal interfaces have been improved to make it easier to support
5373 debugging of multiple languages in the future.
5375 GDB now uses a common structure for symbol information internally.
5376 Minimal symbols (derived from linkage symbols in object files), partial
5377 symbols (from a quick scan of debug information), and full symbols
5378 contain a common subset of information, making it easier to write
5379 shared code that handles any of them.
5381 * New command line options
5383 We now accept --silent as an alias for --quiet.
5387 The memory-mapped-malloc library is now licensed under the GNU Library
5388 General Public License.
5390 *** Changes in GDB-4.7:
5392 * Host/native/target split
5394 GDB has had some major internal surgery to untangle the support for
5395 hosts and remote targets. Now, when you configure GDB for a remote
5396 target, it will no longer load in all of the support for debugging
5397 local programs on the host. When fully completed and tested, this will
5398 ensure that arbitrary host/target combinations are possible.
5400 The primary conceptual shift is to separate the non-portable code in
5401 GDB into three categories. Host specific code is required any time GDB
5402 is compiled on that host, regardless of the target. Target specific
5403 code relates to the peculiarities of the target, but can be compiled on
5404 any host. Native specific code is everything else: it can only be
5405 built when the host and target are the same system. Child process
5406 handling and core file support are two common `native' examples.
5408 GDB's use of /proc for controlling Unix child processes is now cleaner.
5409 It has been split out into a single module under the `target_ops' vector,
5410 plus two native-dependent functions for each system that uses /proc.
5412 * New hosts supported
5414 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5415 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5416 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5418 * New targets supported
5420 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5421 68030 and CPU32 m68030-*-*, m68332-*-*
5423 * New native hosts supported
5425 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5426 (386bsd is not well tested yet)
5427 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5429 * New file formats supported
5431 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5432 supports reading of `a.out.adobe' object files, which are an a.out
5433 format extended with minimal information about multiple sections.
5437 `show copying' is the same as the old `info copying'.
5438 `show warranty' is the same as `info warrantee'.
5439 These were renamed for consistency. The old commands continue to work.
5441 `info handle' is a new alias for `info signals'.
5443 You can now define pre-command hooks, which attach arbitrary command
5444 scripts to any command. The commands in the hook will be executed
5445 prior to the user's command. You can also create a hook which will be
5446 executed whenever the program stops. See gdb.texinfo.
5450 We now deal with Cfront style name mangling, and can even extract type
5451 info from mangled symbols. GDB can automatically figure out which
5452 symbol mangling style your C++ compiler uses.
5454 Calling of methods and virtual functions has been improved as well.
5458 The crash that occured when debugging Sun Ansi-C compiled binaries is
5459 fixed. This was due to mishandling of the extra N_SO stabs output
5462 We also finally got Ultrix 4.2 running in house, and fixed core file
5463 support, with help from a dozen people on the net.
5465 John M. Farrell discovered that the reason that single-stepping was so
5466 slow on all of the Mips based platforms (primarily SGI and DEC) was
5467 that we were trying to demangle and lookup a symbol used for internal
5468 purposes on every instruction that was being stepped through. Changing
5469 the name of that symbol so that it couldn't be mistaken for a C++
5470 mangled symbol sped things up a great deal.
5472 Rich Pixley sped up symbol lookups in general by getting much smarter
5473 about when C++ symbol mangling is necessary. This should make symbol
5474 completion (TAB on the command line) much faster. It's not as fast as
5475 we'd like, but it's significantly faster than gdb-4.6.
5479 A new user controllable variable 'call_scratch_address' can
5480 specify the location of a scratch area to be used when GDB
5481 calls a function in the target. This is necessary because the
5482 usual method of putting the scratch area on the stack does not work
5483 in systems that have separate instruction and data spaces.
5485 We integrated changes to support the 29k UDI (Universal Debugger
5486 Interface), but discovered at the last minute that we didn't have all
5487 of the appropriate copyright paperwork. We are working with AMD to
5488 resolve this, and hope to have it available soon.
5492 We have sped up the remote serial line protocol, especially for targets
5493 with lots of registers. It now supports a new `expedited status' ('T')
5494 message which can be used in place of the existing 'S' status message.
5495 This allows the remote stub to send only the registers that GDB
5496 needs to make a quick decision about single-stepping or conditional
5497 breakpoints, eliminating the need to fetch the entire register set for
5498 each instruction being stepped through.
5500 The GDB remote serial protocol now implements a write-through cache for
5501 registers, only re-reading the registers if the target has run.
5503 There is also a new remote serial stub for SPARC processors. You can
5504 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5505 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5506 processor with a serial port.
5510 Configure.in files have become much easier to read and modify. A new
5511 `table driven' format makes it more obvious what configurations are
5512 supported, and what files each one uses.
5516 There is a new opcodes library which will eventually contain all of the
5517 disassembly routines and opcode tables. At present, it only contains
5518 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5519 disassembler (binutils/objdump) to share these routines.
5521 The libiberty library is now copylefted under the GNU Library General
5522 Public License. This allows more liberal use, and was done so libg++
5523 can use it. This makes no difference to GDB, since the Library License
5524 grants all the rights from the General Public License.
5528 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5529 reference to the stabs symbol info used by the debugger. It is (as far
5530 as we know) the only published document on this fascinating topic. We
5531 encourage you to read it, compare it to the stabs information on your
5532 system, and send improvements on the document in general (to
5533 bug-gdb@prep.ai.mit.edu).
5535 And, of course, many bugs have been fixed.
5538 *** Changes in GDB-4.6:
5540 * Better support for C++ function names
5542 GDB now accepts as input the "demangled form" of C++ overloaded function
5543 names and member function names, and can do command completion on such names
5544 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5545 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5546 Make use of command completion, it is your friend.
5548 GDB also now accepts a variety of C++ mangled symbol formats. They are
5549 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5550 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5551 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5552 for the list of formats.
5554 * G++ symbol mangling problem
5556 Recent versions of gcc have a bug in how they emit debugging information for
5557 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5558 directory) can be applied to gcc to fix the problem. Alternatively, if you
5559 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5560 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5561 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5564 * New 'maintenance' command
5566 All of the commands related to hacking GDB internals have been moved out of
5567 the main command set, and now live behind the 'maintenance' command. This
5568 can also be abbreviated as 'mt'. The following changes were made:
5570 dump-me -> maintenance dump-me
5571 info all-breakpoints -> maintenance info breakpoints
5572 printmsyms -> maintenance print msyms
5573 printobjfiles -> maintenance print objfiles
5574 printpsyms -> maintenance print psymbols
5575 printsyms -> maintenance print symbols
5577 The following commands are new:
5579 maintenance demangle Call internal GDB demangler routine to
5580 demangle a C++ link name and prints the result.
5581 maintenance print type Print a type chain for a given symbol
5583 * Change to .gdbinit file processing
5585 We now read the $HOME/.gdbinit file before processing the argv arguments
5586 (e.g. reading symbol files or core files). This allows global parameters to
5587 be set, which will apply during the symbol reading. The ./.gdbinit is still
5588 read after argv processing.
5590 * New hosts supported
5592 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5594 GNU/Linux support i386-unknown-linux or linux
5596 We are also including code to support the HP/PA running BSD and HPUX. This
5597 is almost guaranteed not to work, as we didn't have time to test or build it
5598 for this release. We are including it so that the more adventurous (or
5599 masochistic) of you can play with it. We also had major problems with the
5600 fact that the compiler that we got from HP doesn't support the -g option.
5603 * New targets supported
5605 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5607 * More smarts about finding #include files
5609 GDB now remembers the compilation directory for all include files, and for
5610 all files from which C is generated (like yacc and lex sources). This
5611 greatly improves GDB's ability to find yacc/lex sources, and include files,
5612 especially if you are debugging your program from a directory different from
5613 the one that contains your sources.
5615 We also fixed a bug which caused difficulty with listing and setting
5616 breakpoints in include files which contain C code. (In the past, you had to
5617 try twice in order to list an include file that you hadn't looked at before.)
5619 * Interesting infernals change
5621 GDB now deals with arbitrary numbers of sections, where the symbols for each
5622 section must be relocated relative to that section's landing place in the
5623 target's address space. This work was needed to support ELF with embedded
5624 stabs used by Solaris-2.0.
5626 * Bug fixes (of course!)
5628 There have been loads of fixes for the following things:
5629 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5630 i960, stabs, DOS(GO32), procfs, etc...
5632 See the ChangeLog for details.
5634 *** Changes in GDB-4.5:
5636 * New machines supported (host and target)
5638 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5640 SGI Irix-4.x mips-sgi-irix4 or iris4
5642 * New malloc package
5644 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5645 Mmalloc is capable of handling mutiple heaps of memory. It is also
5646 capable of saving a heap to a file, and then mapping it back in later.
5647 This can be used to greatly speedup the startup of GDB by using a
5648 pre-parsed symbol table which lives in a mmalloc managed heap. For
5649 more details, please read mmalloc/mmalloc.texi.
5653 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5654 'help info proc' for details.
5656 * MIPS ecoff symbol table format
5658 The code that reads MIPS symbol table format is now supported on all hosts.
5659 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5662 * File name changes for MS-DOS
5664 Many files in the config directories have been renamed to make it easier to
5665 support GDB on MS-DOSe systems (which have very restrictive file name
5666 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5667 environment) is close to working but has some remaining problems. Note
5668 that debugging of DOS programs is not supported, due to limitations
5669 in the ``operating system'', but it can be used to host cross-debugging.
5671 * Cross byte order fixes
5673 Many fixes have been made to support cross debugging of Sparc and MIPS
5674 targets from hosts whose byte order differs.
5676 * New -mapped and -readnow options
5678 If memory-mapped files are available on your system through the 'mmap'
5679 system call, you can use the -mapped option on the `file' or
5680 `symbol-file' commands to cause GDB to write the symbols from your
5681 program into a reusable file. If the program you are debugging is
5682 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5683 Future GDB debugging sessions will notice the presence of this file,
5684 and will quickly map in symbol information from it, rather than reading
5685 the symbol table from the executable program. Using the '-mapped'
5686 option in a GDB `file' or `symbol-file' command has the same effect as
5687 starting GDB with the '-mapped' command-line option.
5689 You can cause GDB to read the entire symbol table immediately by using
5690 the '-readnow' option with any of the commands that load symbol table
5691 information (or on the GDB command line). This makes the command
5692 slower, but makes future operations faster.
5694 The -mapped and -readnow options are typically combined in order to
5695 build a `fred.syms' file that contains complete symbol information.
5696 A simple GDB invocation to do nothing but build a `.syms' file for future
5699 gdb -batch -nx -mapped -readnow programname
5701 The `.syms' file is specific to the host machine on which GDB is run.
5702 It holds an exact image of GDB's internal symbol table. It cannot be
5703 shared across multiple host platforms.
5705 * longjmp() handling
5707 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5708 siglongjmp() without losing control. This feature has not yet been ported to
5709 all systems. It currently works on many 386 platforms, all MIPS-based
5710 platforms (SGI, DECstation, etc), and Sun3/4.
5714 Preliminary work has been put in to support the new Solaris OS from Sun. At
5715 this time, it can control and debug processes, but it is not capable of
5720 As always, many many bug fixes. The major areas were with g++, and mipsread.
5721 People using the MIPS-based platforms should experience fewer mysterious
5722 crashes and trashed symbol tables.
5724 *** Changes in GDB-4.4:
5726 * New machines supported (host and target)
5728 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5730 BSD Reno on Vax vax-dec-bsd
5731 Ultrix on Vax vax-dec-ultrix
5733 * New machines supported (target)
5735 AMD 29000 embedded, using EBMON a29k-none-none
5739 GDB continues to improve its handling of C++. `References' work better.
5740 The demangler has also been improved, and now deals with symbols mangled as
5741 per the Annotated C++ Reference Guide.
5743 GDB also now handles `stabs' symbol information embedded in MIPS
5744 `ecoff' symbol tables. Since the ecoff format was not easily
5745 extensible to handle new languages such as C++, this appeared to be a
5746 good way to put C++ debugging info into MIPS binaries. This option
5747 will be supported in the GNU C compiler, version 2, when it is
5750 * New features for SVR4
5752 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5753 shared libraries. Debugging dynamically linked programs should present
5754 only minor differences from debugging statically linked programs.
5756 The `info proc' command will print out information about any process
5757 on an SVR4 system (including the one you are debugging). At the moment,
5758 it prints the address mappings of the process.
5760 If you bring up GDB on another SVR4 system, please send mail to
5761 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5763 * Better dynamic linking support in SunOS
5765 Reading symbols from shared libraries which contain debugging symbols
5766 now works properly. However, there remain issues such as automatic
5767 skipping of `transfer vector' code during function calls, which
5768 make it harder to debug code in a shared library, than to debug the
5769 same code linked statically.
5773 GDB is now using the latest `getopt' routines from the FSF. This
5774 version accepts the -- prefix for options with long names. GDB will
5775 continue to accept the old forms (-option and +option) as well.
5776 Various single letter abbreviations for options have been explicity
5777 added to the option table so that they won't get overshadowed in the
5778 future by other options that begin with the same letter.
5782 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5783 Many assorted bugs have been handled. Many more remain to be handled.
5784 See the various ChangeLog files (primarily in gdb and bfd) for details.
5787 *** Changes in GDB-4.3:
5789 * New machines supported (host and target)
5791 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5792 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5793 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5795 * Almost SCO Unix support
5797 We had hoped to support:
5798 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5799 (except for core file support), but we discovered very late in the release
5800 that it has problems with process groups that render gdb unusable. Sorry
5801 about that. I encourage people to fix it and post the fixes.
5803 * Preliminary ELF and DWARF support
5805 GDB can read ELF object files on System V Release 4, and can handle
5806 debugging records for C, in DWARF format, in ELF files. This support
5807 is preliminary. If you bring up GDB on another SVR4 system, please
5808 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5813 GDB now uses the latest `readline' library. One user-visible change
5814 is that two tabs will list possible command completions, which previously
5815 required typing M-? (meta-question mark, or ESC ?).
5819 The `stepi' bug that many of you noticed has been squashed.
5820 Many bugs in C++ have been handled. Many more remain to be handled.
5821 See the various ChangeLog files (primarily in gdb and bfd) for details.
5823 * State of the MIPS world (in case you wondered):
5825 GDB can understand the symbol tables emitted by the compilers
5826 supplied by most vendors of MIPS-based machines, including DEC. These
5827 symbol tables are in a format that essentially nobody else uses.
5829 Some versions of gcc come with an assembler post-processor called
5830 mips-tfile. This program is required if you want to do source-level
5831 debugging of gcc-compiled programs. I believe FSF does not ship
5832 mips-tfile with gcc version 1, but it will eventually come with gcc
5835 Debugging of g++ output remains a problem. g++ version 1.xx does not
5836 really support it at all. (If you're lucky, you should be able to get
5837 line numbers and stack traces to work, but no parameters or local
5838 variables.) With some work it should be possible to improve the
5841 When gcc version 2 is released, you will have somewhat better luck.
5842 However, even then you will get confusing results for inheritance and
5845 We will eventually provide full debugging of g++ output on
5846 DECstations. This will probably involve some kind of stabs-in-ecoff
5847 encapulation, but the details have not been worked out yet.
5850 *** Changes in GDB-4.2:
5852 * Improved configuration
5854 Only one copy of `configure' exists now, and it is not self-modifying.
5855 Porting BFD is simpler.
5859 The `step' and `next' commands now only stop at the first instruction
5860 of a source line. This prevents the multiple stops that used to occur
5861 in switch statements, for-loops, etc. `Step' continues to stop if a
5862 function that has debugging information is called within the line.
5866 Lots of small bugs fixed. More remain.
5868 * New host supported (not target)
5870 Intel 386 PC clone running Mach i386-none-mach
5873 *** Changes in GDB-4.1:
5875 * Multiple source language support
5877 GDB now has internal scaffolding to handle several source languages.
5878 It determines the type of each source file from its filename extension,
5879 and will switch expression parsing and number formatting to match the
5880 language of the function in the currently selected stack frame.
5881 You can also specifically set the language to be used, with
5882 `set language c' or `set language modula-2'.
5886 GDB now has preliminary support for the GNU Modula-2 compiler,
5887 currently under development at the State University of New York at
5888 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5889 continue through the fall of 1991 and into 1992.
5891 Other Modula-2 compilers are currently not supported, and attempting to
5892 debug programs compiled with them will likely result in an error as the
5893 symbol table is read. Feel free to work on it, though!
5895 There are hooks in GDB for strict type checking and range checking,
5896 in the `Modula-2 philosophy', but they do not currently work.
5900 GDB can now write to executable and core files (e.g. patch
5901 a variable's value). You must turn this switch on, specify
5902 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5903 by assigning a new value to a variable. Modifications take
5906 * Automatic SunOS shared library reading
5908 When you run your program, GDB automatically determines where its
5909 shared libraries (if any) have been loaded, and reads their symbols.
5910 The `share' command is no longer needed. This also works when
5911 examining core files.
5915 You can specify the number of lines that the `list' command shows.
5918 * New machines supported (host and target)
5920 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5921 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5922 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5924 * New hosts supported (not targets)
5926 IBM RT/PC: romp-ibm-aix or rtpc
5928 * New targets supported (not hosts)
5930 AMD 29000 embedded with COFF a29k-none-coff
5931 AMD 29000 embedded with a.out a29k-none-aout
5932 Ultracomputer remote kernel debug a29k-nyu-kern
5934 * New remote interfaces
5940 *** Changes in GDB-4.0:
5944 Wide output is wrapped at good places to make the output more readable.
5946 Gdb now supports cross-debugging from a host machine of one type to a
5947 target machine of another type. Communication with the target system
5948 is over serial lines. The ``target'' command handles connecting to the
5949 remote system; the ``load'' command will download a program into the
5950 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5951 also supports debugging of realtime processes running under VxWorks,
5952 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5953 stub on the target system.
5955 New CPUs supported include the AMD 29000 and Intel 960.
5957 GDB now reads object files and symbol tables via a ``binary file''
5958 library, which allows a single copy of GDB to debug programs of multiple
5959 object file types such as a.out and coff.
5961 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5962 refcard.dvi and refcard.ps are available to format it).
5965 * Control-Variable user interface simplified
5967 All variables that control the operation of the debugger can be set
5968 by the ``set'' command, and displayed by the ``show'' command.
5970 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5971 ``Show prompt'' produces the response:
5972 Gdb's prompt is new-gdb=>.
5974 What follows are the NEW set commands. The command ``help set'' will
5975 print a complete list of old and new set commands. ``help set FOO''
5976 will give a longer description of the variable FOO. ``show'' will show
5977 all of the variable descriptions and their current settings.
5979 confirm on/off: Enables warning questions for operations that are
5980 hard to recover from, e.g. rerunning the program while
5981 it is already running. Default is ON.
5983 editing on/off: Enables EMACS style command line editing
5984 of input. Previous lines can be recalled with
5985 control-P, the current line can be edited with control-B,
5986 you can search for commands with control-R, etc.
5989 history filename NAME: NAME is where the gdb command history
5990 will be stored. The default is .gdb_history,
5991 or the value of the environment variable
5994 history size N: The size, in commands, of the command history. The
5995 default is 256, or the value of the environment variable
5998 history save on/off: If this value is set to ON, the history file will
5999 be saved after exiting gdb. If set to OFF, the
6000 file will not be saved. The default is OFF.
6002 history expansion on/off: If this value is set to ON, then csh-like
6003 history expansion will be performed on
6004 command line input. The default is OFF.
6006 radix N: Sets the default radix for input and output. It can be set
6007 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6008 in the current radix, so "set radix 10" is always a no-op.
6010 height N: This integer value is the number of lines on a page. Default
6011 is 24, the current `stty rows'' setting, or the ``li#''
6012 setting from the termcap entry matching the environment
6015 width N: This integer value is the number of characters on a line.
6016 Default is 80, the current `stty cols'' setting, or the ``co#''
6017 setting from the termcap entry matching the environment
6020 Note: ``set screensize'' is obsolete. Use ``set height'' and
6021 ``set width'' instead.
6023 print address on/off: Print memory addresses in various command displays,
6024 such as stack traces and structure values. Gdb looks
6025 more ``symbolic'' if you turn this off; it looks more
6026 ``machine level'' with it on. Default is ON.
6028 print array on/off: Prettyprint arrays. New convenient format! Default
6031 print demangle on/off: Print C++ symbols in "source" form if on,
6034 print asm-demangle on/off: Same, for assembler level printouts
6037 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6040 * Support for Epoch Environment.
6042 The epoch environment is a version of Emacs v18 with windowing. One
6043 new command, ``inspect'', is identical to ``print'', except that if you
6044 are running in the epoch environment, the value is printed in its own
6048 * Support for Shared Libraries
6050 GDB can now debug programs and core files that use SunOS shared libraries.
6051 Symbols from a shared library cannot be referenced
6052 before the shared library has been linked with the program (this
6053 happens after you type ``run'' and before the function main() is entered).
6054 At any time after this linking (including when examining core files
6055 from dynamically linked programs), gdb reads the symbols from each
6056 shared library when you type the ``sharedlibrary'' command.
6057 It can be abbreviated ``share''.
6059 sharedlibrary REGEXP: Load shared object library symbols for files
6060 matching a unix regular expression. No argument
6061 indicates to load symbols for all shared libraries.
6063 info sharedlibrary: Status of loaded shared libraries.
6068 A watchpoint stops execution of a program whenever the value of an
6069 expression changes. Checking for this slows down execution
6070 tremendously whenever you are in the scope of the expression, but is
6071 quite useful for catching tough ``bit-spreader'' or pointer misuse
6072 problems. Some machines such as the 386 have hardware for doing this
6073 more quickly, and future versions of gdb will use this hardware.
6075 watch EXP: Set a watchpoint (breakpoint) for an expression.
6077 info watchpoints: Information about your watchpoints.
6079 delete N: Deletes watchpoint number N (same as breakpoints).
6080 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6081 enable N: Re-enables watchpoint number N (same as breakpoints).
6084 * C++ multiple inheritance
6086 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6089 * C++ exception handling
6091 Gdb now supports limited C++ exception handling. Besides the existing
6092 ability to breakpoint on an exception handler, gdb can breakpoint on
6093 the raising of an exception (before the stack is peeled back to the
6096 catch FOO: If there is a FOO exception handler in the dynamic scope,
6097 set a breakpoint to catch exceptions which may be raised there.
6098 Multiple exceptions (``catch foo bar baz'') may be caught.
6100 info catch: Lists all exceptions which may be caught in the
6101 current stack frame.
6104 * Minor command changes
6106 The command ``call func (arg, arg, ...)'' now acts like the print
6107 command, except it does not print or save a value if the function's result
6108 is void. This is similar to dbx usage.
6110 The ``up'' and ``down'' commands now always print the frame they end up
6111 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6112 frames without printing.
6114 * New directory command
6116 'dir' now adds directories to the FRONT of the source search path.
6117 The path starts off empty. Source files that contain debug information
6118 about the directory in which they were compiled can be found even
6119 with an empty path; Sun CC and GCC include this information. If GDB can't
6120 find your source file in the current directory, type "dir .".
6122 * Configuring GDB for compilation
6124 For normal use, type ``./configure host''. See README or gdb.texinfo
6127 GDB now handles cross debugging. If you are remotely debugging between
6128 two different machines, type ``./configure host -target=targ''.
6129 Host is the machine where GDB will run; targ is the machine
6130 where the program that you are debugging will run.