1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.9
6 * Support for process record-replay and reverse debugging on aarch64*-linux*
7 targets has been added. GDB now supports recording of A64 instruction set
8 including advance SIMD instructions.
10 * GDB now honors the content of the file /proc/PID/coredump_filter
11 (PID is the process ID) on GNU/Linux systems. This file can be used
12 to specify the types of memory mappings that will be included in a
13 corefile. For more information, please refer to the manual page of
14 "core(5)". GDB also has a new command: "set use-coredump-filter
15 on|off". It allows to set whether GDB will read the content of the
16 /proc/PID/coredump_filter file when generating a corefile.
18 * The "info os" command on GNU/Linux can now display information on
20 "info os cpus" Listing of all cpus/cores on the system
22 * GDB has two new commands: "set serial parity odd|even|none" and
23 "show serial parity". These allows to set or show parity for the
26 * The "info source" command now displays the producer string if it was
27 present in the debug info. This typically includes the compiler version
28 and may include things like its command line arguments.
30 * The "info dll", an alias of the "info sharedlibrary" command,
31 is now available on all platforms.
33 * Directory names supplied to the "set sysroot" commands may be
34 prefixed with "target:" to tell GDB to access shared libraries from
35 the target system, be it local or remote. This replaces the prefix
36 "remote:". The default sysroot has been changed from "" to
37 "target:". "remote:" is automatically converted to "target:" for
38 backward compatibility.
40 * The system root specified by "set sysroot" will be prepended to the
41 filename of the main executable (if reported to GDB as absolute by
42 the operating system) when starting processes remotely, and when
43 attaching to already-running local or remote processes.
45 * GDB now supports automatic location and retrieval of executable
46 files from remote targets. Remote debugging can now be initiated
47 using only a "target remote" or "target extended-remote" command
48 (no "set sysroot" or "file" commands are required). See "New remote
51 * The "dump" command now supports verilog hex format.
53 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
57 ** Memory ports can now be unbuffered.
61 ** gdb.Objfile objects have a new attribute "username",
62 which is the name of the objfile as specified by the user,
63 without, for example, resolving symlinks.
64 ** You can now write frame unwinders in Python.
65 ** gdb.Type objects have a new method "optimized_out",
66 returning optimized out gdb.Value instance of this type.
67 ** gdb.Value objects have new methods "reference_value" and
68 "const_value" which return a reference to the value and a
69 "const" version of the value respectively.
73 maint print symbol-cache
74 Print the contents of the symbol cache.
76 maint print symbol-cache-statistics
77 Print statistics of symbol cache usage.
79 maint flush-symbol-cache
80 Flush the contents of the symbol cache.
84 Start branch trace recording using Branch Trace Store (BTS) format.
87 Evaluate expression by using the compiler and print result.
91 Explicit commands for enabling and disabling tui mode.
94 set mpx bound on i386 and amd64
95 Support for bound table investigation on Intel(R) MPX enabled applications.
100 Renamed from "set debug dwarf2-die".
102 Renamed from "show debug dwarf2-die".
105 Renamed from "set debug dwarf2-read".
106 show debug dwarf-read
107 Renamed from "show debug dwarf2-read".
109 maint set dwarf always-disassemble
110 Renamed from "maint set dwarf2 always-disassemble".
111 maint show dwarf always-disassemble
112 Renamed from "maint show dwarf2 always-disassemble".
114 maint set dwarf max-cache-age
115 Renamed from "maint set dwarf2 max-cache-age".
116 maint show dwarf max-cache-age
117 Renamed from "maint show dwarf2 max-cache-age".
120 show debug dwarf-line
121 Control display of debugging info regarding DWARF line processing.
125 Set the maximum number of candidates to be considered during
126 completion. The default value is 200. This limit allows GDB
127 to avoid generating large completion lists, the computation of
128 which can cause the debugger to become temporarily unresponsive.
130 maint set symbol-cache-size
131 maint show symbol-cache-size
132 Control the size of the symbol cache.
134 set|show record btrace bts buffer-size
135 Set and show the size of the ring buffer used for branch tracing in
137 The obtained size may differ from the requested size. Use "info
138 record" to see the obtained buffer size.
140 set debug linux-namespaces
141 show debug linux-namespaces
142 Control display of debugging info regarding Linux namespaces.
144 * The command 'thread apply all' can now support new option '-ascending'
145 to call its specified command for all threads in ascending order.
147 * Python/Guile scripting
149 ** GDB now supports auto-loading of Python/Guile scripts contained in the
150 special section named `.debug_gdb_scripts'.
154 qXfer:btrace-conf:read
155 Return the branch trace configuration for the current thread.
157 Qbtrace-conf:bts:size
158 Set the requested ring buffer size for branch tracing in BTS format.
161 Indicates a memory breakpoint instruction was executed, irrespective
162 of whether it was GDB that planted the breakpoint or the breakpoint
163 is hardcoded in the program. This is required for correct non-stop
167 Indicates the target stopped for a hardware breakpoint. This is
168 required for correct non-stop mode operation.
171 Return information about files on the remote system.
174 Return the full absolute name of the file that was executed to
175 create a process running on the remote system.
178 Select the filesystem on which vFile: operations with filename
179 arguments will operate. This is required for GDB to be able to
180 access files on remote targets where the remote stub does not
181 share a common filesystem with the inferior(s).
184 Indicates that a fork system call was executed.
187 Indicates that a vfork system call was executed.
189 vforkdone stop reason
190 Indicates that a vfork child of the specified process has executed
191 an exec or exit, allowing the vfork parent to resume execution.
193 fork-events and vfork-events features in qSupported
194 The qSupported packet allows GDB to request support for fork and
195 vfork events using new 'gdbfeatures' fork-events and vfork-events,
196 and the qSupported response can contain the corresponding
197 'stubfeatures'. Set and show commands can be used to display
198 whether these features are enabled.
200 * Extended-remote fork events
202 ** GDB now has support for fork events on extended-remote Linux
203 targets. For targets with Linux kernels 2.5.60 and later, this
204 enables follow-fork-mode and detach-on-fork for both fork and
205 vfork, as well as fork and vfork catchpoints.
207 * The info record command now shows the recording format and the
208 branch tracing configuration for the current thread when using
209 the btrace record target.
210 For the BTS format, it shows the ring buffer size.
212 * GDB now has support for DTrace USDT (Userland Static Defined
213 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
215 * GDB now supports access to vector registers on S/390 GNU/Linux
218 * Removed command line options
220 -xdb HP-UX XDB compatibility mode.
222 * Removed targets and native configurations
224 HP/PA running HP-UX hppa*-*-hpux*
225 Itanium running HP-UX ia64-*-hpux*
227 *** Changes in GDB 7.9.1
231 ** Xmethods can now specify a result type.
233 *** Changes in GDB 7.9
235 * GDB now supports hardware watchpoints on x86 GNU Hurd.
239 ** You can now access frame registers from Python scripts.
240 ** New attribute 'producer' for gdb.Symtab objects.
241 ** gdb.Objfile objects have a new attribute "progspace",
242 which is the gdb.Progspace object of the containing program space.
243 ** gdb.Objfile objects have a new attribute "owner".
244 ** gdb.Objfile objects have a new attribute "build_id",
245 which is the build ID generated when the file was built.
246 ** gdb.Objfile objects have a new method "add_separate_debug_file".
247 ** A new event "gdb.clear_objfiles" has been added, triggered when
248 selecting a new file to debug.
249 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
250 ** New function gdb.lookup_objfile.
252 New events which are triggered when GDB modifies the state of the
255 ** gdb.events.inferior_call_pre: Function call is about to be made.
256 ** gdb.events.inferior_call_post: Function call has just been made.
257 ** gdb.events.memory_changed: A memory location has been altered.
258 ** gdb.events.register_changed: A register has been altered.
260 * New Python-based convenience functions:
262 ** $_caller_is(name [, number_of_frames])
263 ** $_caller_matches(regexp [, number_of_frames])
264 ** $_any_caller_is(name [, number_of_frames])
265 ** $_any_caller_matches(regexp [, number_of_frames])
267 * GDB now supports the compilation and injection of source code into
268 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
269 to compile the source code to object code, and if successful, inject
270 and execute that code within the current context of the inferior.
271 Currently the C language is supported. The commands used to
272 interface with this new feature are:
274 compile code [-raw|-r] [--] [source code]
275 compile file [-raw|-r] filename
279 demangle [-l language] [--] name
280 Demangle "name" in the specified language, or the current language
281 if elided. This command is renamed from the "maint demangle" command.
282 The latter is kept as a no-op to avoid "maint demangle" being interpreted
283 as "maint demangler-warning".
285 queue-signal signal-name-or-number
286 Queue a signal to be delivered to the thread when it is resumed.
288 add-auto-load-scripts-directory directory
289 Add entries to the list of directories from which to load auto-loaded
292 maint print user-registers
293 List all currently available "user" registers.
295 compile code [-r|-raw] [--] [source code]
296 Compile, inject, and execute in the inferior the executable object
297 code produced by compiling the provided source code.
299 compile file [-r|-raw] filename
300 Compile and inject into the inferior the executable object code
301 produced by compiling the source code stored in the filename
304 * On resume, GDB now always passes the signal the program had stopped
305 for to the thread the signal was sent to, even if the user changed
306 threads before resuming. Previously GDB would often (but not
307 always) deliver the signal to the thread that happens to be current
310 * Conversely, the "signal" command now consistently delivers the
311 requested signal to the current thread. GDB now asks for
312 confirmation if the program had stopped for a signal and the user
313 switched threads meanwhile.
315 * "breakpoint always-inserted" modes "off" and "auto" merged.
317 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
318 won't remove breakpoints from the target until all threads stop,
319 even in non-stop mode. The "auto" mode has been removed, and "off"
320 is now the default mode.
324 set debug symbol-lookup
325 show debug symbol-lookup
326 Control display of debugging info regarding symbol lookup.
330 ** The -list-thread-groups command outputs an exit-code field for
331 inferiors that have exited.
335 MIPS SDE mips*-sde*-elf*
339 Support for these obsolete configurations has been removed.
341 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
342 SGI Irix-5.x mips-*-irix5*
343 SGI Irix-6.x mips-*-irix6*
344 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
345 VAX running Ultrix vax-*-ultrix*
347 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
348 and "assf"), have been removed. Use the "sharedlibrary" command, or
349 its alias "share", instead.
351 *** Changes in GDB 7.8
353 * New command line options
356 This is an alias for the --data-directory option.
358 * GDB supports printing and modifying of variable length automatic arrays
359 as specified in ISO C99.
361 * The ARM simulator now supports instruction level tracing
362 with or without disassembly.
366 GDB now has support for scripting using Guile. Whether this is
367 available is determined at configure time.
368 Guile version 2.0 or greater is required.
369 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
371 * New commands (for set/show, see "New options" below)
375 Invoke CODE by passing it to the Guile interpreter.
379 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
381 info auto-load guile-scripts [regexp]
382 Print the list of automatically loaded Guile scripts.
384 * The source command is now capable of sourcing Guile scripts.
385 This feature is dependent on the debugger being built with Guile support.
389 set print symbol-loading (off|brief|full)
390 show print symbol-loading
391 Control whether to print informational messages when loading symbol
392 information for a file. The default is "full", but when debugging
393 programs with large numbers of shared libraries the amount of output
396 set guile print-stack (none|message|full)
397 show guile print-stack
398 Show a stack trace when an error is encountered in a Guile script.
400 set auto-load guile-scripts (on|off)
401 show auto-load guile-scripts
402 Control auto-loading of Guile script files.
404 maint ada set ignore-descriptive-types (on|off)
405 maint ada show ignore-descriptive-types
406 Control whether the debugger should ignore descriptive types in Ada
407 programs. The default is not to ignore the descriptive types. See
408 the user manual for more details on descriptive types and the intended
409 usage of this option.
411 set auto-connect-native-target
413 Control whether GDB is allowed to automatically connect to the
414 native target for the run, attach, etc. commands when not connected
415 to any target yet. See also "target native" below.
417 set record btrace replay-memory-access (read-only|read-write)
418 show record btrace replay-memory-access
419 Control what memory accesses are allowed during replay.
421 maint set target-async (on|off)
422 maint show target-async
423 This controls whether GDB targets operate in synchronous or
424 asynchronous mode. Normally the default is asynchronous, if it is
425 available; but this can be changed to more easily debug problems
426 occurring only in synchronous mode.
428 set mi-async (on|off)
430 Control whether MI asynchronous mode is preferred. This supersedes
431 "set target-async" of previous GDB versions.
433 * "set target-async" is deprecated as a CLI option and is now an alias
434 for "set mi-async" (only puts MI into async mode).
436 * Background execution commands (e.g., "c&", "s&", etc.) are now
437 possible ``out of the box'' if the target supports them. Previously
438 the user would need to explicitly enable the possibility with the
439 "set target-async on" command.
441 * New features in the GDB remote stub, GDBserver
443 ** New option --debug-format=option1[,option2,...] allows one to add
444 additional text to each output. At present only timestamps
445 are supported: --debug-format=timestamps.
446 Timestamps can also be turned on with the
447 "monitor set debug-format timestamps" command from GDB.
449 * The 'record instruction-history' command now starts counting instructions
450 at one. This also affects the instruction ranges reported by the
451 'record function-call-history' command when given the /i modifier.
453 * The command 'record function-call-history' supports a new modifier '/c' to
454 indent the function names based on their call stack depth.
455 The fields for the '/i' and '/l' modifier have been reordered.
456 The source line range is now prefixed with 'at'.
457 The instruction range is now prefixed with 'inst'.
458 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
459 "record instruction-history" and "list" commands.
461 * The ranges given as arguments to the 'record function-call-history' and
462 'record instruction-history' commands are now inclusive.
464 * The btrace record target now supports the 'record goto' command.
465 For locations inside the execution trace, the back trace is computed
466 based on the information stored in the execution trace.
468 * The btrace record target supports limited reverse execution and replay.
469 The target does not record data and therefore does not allow reading
472 * The "catch syscall" command now works on s390*-linux* targets.
474 * The "compare-sections" command is no longer specific to target
475 remote. It now works with all targets.
477 * All native targets are now consistently called "native".
478 Consequently, the "target child", "target GNU", "target djgpp",
479 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
480 commands have been replaced with "target native". The QNX/NTO port
481 leaves the "procfs" target in place and adds a "native" target for
482 consistency with other ports. The impact on users should be minimal
483 as these commands previously either throwed an error, or were
484 no-ops. The target's name is visible in the output of the following
485 commands: "help target", "info target", "info files", "maint print
488 * The "target native" command now connects to the native target. This
489 can be used to launch native programs even when "set
490 auto-connect-native-target" is set to off.
492 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.
494 * Support for Intel(R) AVX-512 registers on GNU/Linux.
495 Support displaying and modifying Intel(R) AVX-512 registers
496 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
500 qXfer:btrace:read's annex
501 The qXfer:btrace:read packet supports a new annex 'delta' to read
502 branch trace incrementally.
506 ** Valid Python operations on gdb.Value objects representing
507 structs/classes invoke the corresponding overloaded operators if
509 ** New `Xmethods' feature in the Python API. Xmethods are
510 additional methods or replacements for existing methods of a C++
511 class. This feature is useful for those cases where a method
512 defined in C++ source code could be inlined or optimized out by
513 the compiler, making it unavailable to GDB.
516 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
518 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
519 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
520 its alias "share", instead.
522 * The commands "set remotebaud" and "show remotebaud" are no longer
523 supported. Use "set serial baud" and "show serial baud" (respectively)
528 ** A new option "-gdb-set mi-async" replaces "-gdb-set
529 target-async". The latter is left as a deprecated alias of the
530 former for backward compatibility. If the target supports it,
531 CLI background execution commands are now always possible by
532 default, independently of whether the frontend stated a
533 preference for asynchronous execution with "-gdb-set mi-async".
534 Previously "-gdb-set target-async off" affected both MI execution
535 commands and CLI execution commands.
537 *** Changes in GDB 7.7
539 * Improved support for process record-replay and reverse debugging on
540 arm*-linux* targets. Support for thumb32 and syscall instruction
541 recording has been added.
543 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
545 * GDB now supports Fission DWP file format version 2.
546 http://gcc.gnu.org/wiki/DebugFission
548 * New convenience function "$_isvoid", to check whether an expression
549 is void. A void expression is an expression where the type of the
550 result is "void". For example, some convenience variables may be
551 "void" when evaluated (e.g., "$_exitcode" before the execution of
552 the program being debugged; or an undefined convenience variable).
553 Another example, when calling a function whose return type is
556 * The "maintenance print objfiles" command now takes an optional regexp.
558 * The "catch syscall" command now works on arm*-linux* targets.
560 * GDB now consistently shows "<not saved>" when printing values of
561 registers the debug info indicates have not been saved in the frame
562 and there's nowhere to retrieve them from
563 (callee-saved/call-clobbered registers):
568 (gdb) info registers rax
571 Before, the former would print "<optimized out>", and the latter
572 "*value not available*".
574 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
579 ** Frame filters and frame decorators have been added.
580 ** Temporary breakpoints are now supported.
581 ** Line tables representation has been added.
582 ** New attribute 'parent_type' for gdb.Field objects.
583 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
584 ** New attribute 'name' for gdb.Type objects.
588 Nios II ELF nios2*-*-elf
589 Nios II GNU/Linux nios2*-*-linux
590 Texas Instruments MSP430 msp430*-*-elf
592 * Removed native configurations
594 Support for these a.out NetBSD and OpenBSD obsolete configurations has
595 been removed. ELF variants of these configurations are kept supported.
597 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
598 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
599 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
600 i[34567]86-*-openbsd3.[0-3]
601 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
602 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
603 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
607 Like "catch throw", but catches a re-thrown exception.
609 Renamed from old "maint check-symtabs".
611 Perform consistency checks on symtabs.
613 Expand symtabs matching an optional regexp.
616 Display the details of GDB configure-time options.
618 maint set|show per-command
619 maint set|show per-command space
620 maint set|show per-command time
621 maint set|show per-command symtab
622 Enable display of per-command gdb resource usage.
624 remove-symbol-file FILENAME
625 remove-symbol-file -a ADDRESS
626 Remove a symbol file added via add-symbol-file. The file to remove
627 can be identified by its filename or by an address that lies within
628 the boundaries of this symbol file in memory.
631 info exceptions REGEXP
632 Display the list of Ada exceptions defined in the program being
633 debugged. If provided, only the exceptions whose names match REGEXP
638 set debug symfile off|on
640 Control display of debugging info regarding reading symbol files and
641 symbol tables within those files
643 set print raw frame-arguments
644 show print raw frame-arguments
645 Set/show whether to print frame arguments in raw mode,
646 disregarding any defined pretty-printers.
648 set remote trace-status-packet
649 show remote trace-status-packet
650 Set/show the use of remote protocol qTStatus packet.
654 Control display of debugging messages related to Nios II targets.
658 Control whether target-assisted range stepping is enabled.
660 set startup-with-shell
661 show startup-with-shell
662 Specifies whether Unix child processes are started via a shell or
667 Use the target memory cache for accesses to the code segment. This
668 improves performance of remote debugging (particularly disassembly).
670 * You can now use a literal value 'unlimited' for options that
671 interpret 0 or -1 as meaning "unlimited". E.g., "set
672 trace-buffer-size unlimited" is now an alias for "set
673 trace-buffer-size -1" and "set height unlimited" is now an alias for
676 * The "set debug symtab-create" debugging option of GDB has been changed to
677 accept a verbosity level. 0 means "off", 1 provides basic debugging
678 output, and values of 2 or greater provides more verbose output.
680 * New command-line options
682 Display the details of GDB configure-time options.
684 * The command 'tsave' can now support new option '-ctf' to save trace
685 buffer in Common Trace Format.
687 * Newly installed $prefix/bin/gcore acts as a shell interface for the
690 * GDB now implements the the C++ 'typeid' operator.
692 * The new convenience variable $_exception holds the exception being
693 thrown or caught at an exception-related catchpoint.
695 * The exception-related catchpoints, like "catch throw", now accept a
696 regular expression which can be used to filter exceptions by type.
698 * The new convenience variable $_exitsignal is automatically set to
699 the terminating signal number when the program being debugged dies
700 due to an uncaught signal.
704 ** All MI commands now accept an optional "--language" option.
705 Support for this feature can be verified by using the "-list-features"
706 command, which should contain "language-option".
708 ** The new command -info-gdb-mi-command allows the user to determine
709 whether a GDB/MI command is supported or not.
711 ** The "^error" result record returned when trying to execute an undefined
712 GDB/MI command now provides a variable named "code" whose content is the
713 "undefined-command" error code. Support for this feature can be verified
714 by using the "-list-features" command, which should contain
715 "undefined-command-error-code".
717 ** The -trace-save MI command can optionally save trace buffer in Common
720 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
722 ** The command -data-list-register-values now accepts an optional
723 "--skip-unavailable" option. When used, only the available registers
726 ** The new command -trace-frame-collected dumps collected variables,
727 computed expressions, tvars, memory and registers in a traceframe.
729 ** The commands -stack-list-locals, -stack-list-arguments and
730 -stack-list-variables now accept an option "--skip-unavailable".
731 When used, only the available locals or arguments are displayed.
733 ** The -exec-run command now accepts an optional "--start" option.
734 When used, the command follows the same semantics as the "start"
735 command, stopping the program's execution at the start of its
736 main subprogram. Support for this feature can be verified using
737 the "-list-features" command, which should contain
738 "exec-run-start-option".
740 ** The new commands -catch-assert and -catch-exceptions insert
741 catchpoints stopping the program when Ada exceptions are raised.
743 ** The new command -info-ada-exceptions provides the equivalent of
744 the new "info exceptions" command.
746 * New system-wide configuration scripts
747 A GDB installation now provides scripts suitable for use as system-wide
748 configuration scripts for the following systems:
752 * GDB now supports target-assigned range stepping with remote targets.
753 This improves the performance of stepping source lines by reducing
754 the number of control packets from/to GDB. See "New remote packets"
757 * GDB now understands the element 'tvar' in the XML traceframe info.
758 It has the id of the collected trace state variables.
760 * On S/390 targets that provide the transactional-execution feature,
761 the program interruption transaction diagnostic block (TDB) is now
762 represented as a number of additional "registers" in GDB.
768 The vCont packet supports a new 'r' action, that tells the remote
769 stub to step through an address range itself, without GDB
770 involvemement at each single-step.
772 qXfer:libraries-svr4:read's annex
773 The previously unused annex of the qXfer:libraries-svr4:read packet
774 is now used to support passing an argument list. The remote stub
775 reports support for this argument list to GDB's qSupported query.
776 The defined arguments are "start" and "prev", used to reduce work
777 necessary for library list updating, resulting in significant
780 * New features in the GDB remote stub, GDBserver
782 ** GDBserver now supports target-assisted range stepping. Currently
783 enabled on x86/x86_64 GNU/Linux targets.
785 ** GDBserver now adds element 'tvar' in the XML in the reply to
786 'qXfer:traceframe-info:read'. It has the id of the collected
787 trace state variables.
789 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
792 * New 'z' formatter for printing and examining memory, this displays the
793 value as hexadecimal zero padded on the left to the size of the type.
795 * GDB can now use Windows x64 unwinding data.
797 * The "set remotebaud" command has been replaced by "set serial baud".
798 Similarly, "show remotebaud" has been replaced by "show serial baud".
799 The "set remotebaud" and "show remotebaud" commands are still available
800 to provide backward compatibility with older versions of GDB.
802 *** Changes in GDB 7.6
804 * Target record has been renamed to record-full.
805 Record/replay is now enabled with the "record full" command.
806 This also affects settings that are associated with full record/replay
807 that have been moved from "set/show record" to "set/show record full":
809 set|show record full insn-number-max
810 set|show record full stop-at-limit
811 set|show record full memory-query
813 * A new record target "record-btrace" has been added. The new target
814 uses hardware support to record the control-flow of a process. It
815 does not support replaying the execution, but it implements the
816 below new commands for investigating the recorded execution log.
817 This new recording method can be enabled using:
821 The "record-btrace" target is only available on Intel Atom processors
822 and requires a Linux kernel 2.6.32 or later.
824 * Two new commands have been added for record/replay to give information
825 about the recorded execution without having to replay the execution.
826 The commands are only supported by "record btrace".
828 record instruction-history prints the execution history at
829 instruction granularity
831 record function-call-history prints the execution history at
834 * New native configurations
836 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
837 FreeBSD/powerpc powerpc*-*-freebsd
838 x86_64/Cygwin x86_64-*-cygwin*
839 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
843 ARM AArch64 aarch64*-*-elf
844 ARM AArch64 GNU/Linux aarch64*-*-linux
845 Lynx 178 PowerPC powerpc-*-lynx*178
846 x86_64/Cygwin x86_64-*-cygwin*
847 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
849 * If the configured location of system.gdbinit file (as given by the
850 --with-system-gdbinit option at configure time) is in the
851 data-directory (as specified by --with-gdb-datadir at configure
852 time) or in one of its subdirectories, then GDB will look for the
853 system-wide init file in the directory specified by the
854 --data-directory command-line option.
856 * New command line options:
858 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
859 other initialization files, unlike -nx which disables all of them.
861 * Removed command line options
863 -epoch This was used by the gdb mode in Epoch, an ancient fork of
866 * The 'ptype' and 'whatis' commands now accept an argument to control
869 * 'info proc' now works on some core files.
873 ** Vectors can be created with gdb.Type.vector.
875 ** Python's atexit.register now works in GDB.
877 ** Types can be pretty-printed via a Python API.
879 ** Python 3 is now supported (in addition to Python 2.4 or later)
881 ** New class gdb.Architecture exposes GDB's internal representation
882 of architecture in the Python API.
884 ** New method Frame.architecture returns the gdb.Architecture object
885 corresponding to the frame's architecture.
887 * New Python-based convenience functions:
889 ** $_memeq(buf1, buf2, length)
890 ** $_streq(str1, str2)
892 ** $_regex(str, regex)
894 * The 'cd' command now defaults to using '~' (the home directory) if not
897 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
898 default for GCC since November 2000.
900 * The command 'forward-search' can now be abbreviated as 'fo'.
902 * The command 'info tracepoints' can now display 'installed on target'
903 or 'not installed on target' for each non-pending location of tracepoint.
905 * New configure options
907 --enable-libmcheck/--disable-libmcheck
908 By default, development versions are built with -lmcheck on hosts
909 that support it, in order to help track memory corruption issues.
910 Release versions, on the other hand, are built without -lmcheck
911 by default. The --enable-libmcheck/--disable-libmcheck configure
912 options allow the user to override that default.
913 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
914 This configure option allows the user to build GDB with
915 libbabeltrace using which GDB can read Common Trace Format data.
917 * New commands (for set/show, see "New options" below)
920 Catch signals. This is similar to "handle", but allows commands and
921 conditions to be attached.
924 List the BFDs known to GDB.
926 python-interactive [command]
928 Start a Python interactive prompt, or evaluate the optional command
929 and print the result of expressions.
932 "py" is a new alias for "python".
934 enable type-printer [name]...
935 disable type-printer [name]...
936 Enable or disable type printers.
940 ** For the Renesas Super-H architecture, the "regs" command has been removed
941 (has been deprecated in GDB 7.5), and "info all-registers" should be used
946 set print type methods (on|off)
947 show print type methods
948 Control whether method declarations are displayed by "ptype".
949 The default is to show them.
951 set print type typedefs (on|off)
952 show print type typedefs
953 Control whether typedef definitions are displayed by "ptype".
954 The default is to show them.
956 set filename-display basename|relative|absolute
957 show filename-display
958 Control the way in which filenames is displayed.
959 The default is "relative", which preserves previous behavior.
961 set trace-buffer-size
962 show trace-buffer-size
963 Request target to change the size of trace buffer.
965 set remote trace-buffer-size-packet auto|on|off
966 show remote trace-buffer-size-packet
967 Control the use of the remote protocol `QTBuffer:size' packet.
971 Control display of debugging messages related to ARM AArch64.
974 set debug coff-pe-read
975 show debug coff-pe-read
976 Control display of debugging messages related to reading of COFF/PE
981 Control display of debugging messages related to Mach-O symbols
984 set debug notification
985 show debug notification
986 Control display of debugging info for async remote notification.
990 ** Command parameter changes are now notified using new async record
991 "=cmd-param-changed".
992 ** Trace frame changes caused by command "tfind" are now notified using
993 new async record "=traceframe-changed".
994 ** The creation, deletion and modification of trace state variables
995 are now notified using new async records "=tsv-created",
996 "=tsv-deleted" and "=tsv-modified".
997 ** The start and stop of process record are now notified using new
998 async record "=record-started" and "=record-stopped".
999 ** Memory changes are now notified using new async record
1001 ** The data-disassemble command response will include a "fullname" field
1002 containing the absolute file name when source has been requested.
1003 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1004 command, to allow pattern filling of memory areas.
1005 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1006 library load/unload events.
1007 ** The response to breakpoint commands and breakpoint async records
1008 includes an "installed" field containing a boolean state about each
1009 non-pending tracepoint location is whether installed on target or not.
1010 ** Output of the "-trace-status" command includes a "trace-file" field
1011 containing the name of the trace file being examined. This field is
1012 optional, and only present when examining a trace file.
1013 ** The "fullname" field is now always present along with the "file" field,
1014 even if the file cannot be found by GDB.
1016 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1017 You must have the LZMA library available when configuring GDB for this
1018 feature to be enabled. For more information, see:
1019 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1021 * New remote packets
1024 Set the size of trace buffer. The remote stub reports support for this
1025 packet to gdb's qSupported query.
1028 Enable Branch Trace Store (BTS)-based branch tracing for the current
1029 thread. The remote stub reports support for this packet to gdb's
1033 Disable branch tracing for the current thread. The remote stub reports
1034 support for this packet to gdb's qSupported query.
1037 Read the traced branches for the current thread. The remote stub
1038 reports support for this packet to gdb's qSupported query.
1040 *** Changes in GDB 7.5
1042 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1043 for more x32 ABI info.
1045 * GDB now supports access to MIPS DSP registers on Linux targets.
1047 * GDB now supports debugging microMIPS binaries.
1049 * The "info os" command on GNU/Linux can now display information on
1050 several new classes of objects managed by the operating system:
1051 "info os procgroups" lists process groups
1052 "info os files" lists file descriptors
1053 "info os sockets" lists internet-domain sockets
1054 "info os shm" lists shared-memory regions
1055 "info os semaphores" lists semaphores
1056 "info os msg" lists message queues
1057 "info os modules" lists loaded kernel modules
1059 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1060 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1061 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1062 options and inspect the probe arguments using the new $_probe_arg family
1063 of convenience variables. You can obtain more information about SystemTap
1064 in <http://sourceware.org/systemtap/>.
1066 * GDB now supports reversible debugging on ARM, it allows you to
1067 debug basic ARM and THUMB instructions, and provides
1068 record/replay support.
1070 * The option "symbol-reloading" has been deleted as it is no longer used.
1074 ** GDB commands implemented in Python can now be put in command class
1077 ** The "maint set python print-stack on|off" is now deleted.
1079 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1080 apply "flag enum"-style pretty-printing to any enum.
1082 ** gdb.lookup_symbol can now work when there is no current frame.
1084 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1085 the source at which the symbol was defined.
1087 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1088 method 'value'. The former indicates whether the symbol needs a
1089 frame in order to compute its value, and the latter computes the
1092 ** A new method 'referenced_value' on gdb.Value objects which can
1093 dereference pointer as well as C++ reference values.
1095 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1096 which return the global and static blocks (as gdb.Block objects),
1097 of the underlying symbol table, respectively.
1099 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1100 object associated with a PC value.
1102 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1103 of the address range occupied by code for the current source line.
1105 * Go language support.
1106 GDB now supports debugging programs written in the Go programming
1109 * GDBserver now supports stdio connections.
1110 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1112 * The binary "gdbtui" can no longer be built or installed.
1113 Use "gdb -tui" instead.
1115 * GDB will now print "flag" enums specially. A flag enum is one where
1116 all the enumerator values have no bits in common when pairwise
1117 "and"ed. When printing a value whose type is a flag enum, GDB will
1118 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1119 (gdb) print (enum E) 3
1122 * The filename part of a linespec will now match trailing components
1123 of a source file name. For example, "break gcc/expr.c:1000" will
1124 now set a breakpoint in build/gcc/expr.c, but not
1125 build/libcpp/expr.c.
1127 * The "info proc" and "generate-core-file" commands will now also
1128 work on remote targets connected to GDBserver on Linux.
1130 * The command "info catch" has been removed. It has been disabled
1131 since December 2007.
1133 * The "catch exception" and "catch assert" commands now accept
1134 a condition at the end of the command, much like the "break"
1135 command does. For instance:
1137 (gdb) catch exception Constraint_Error if Barrier = True
1139 Previously, it was possible to add a condition to such catchpoints,
1140 but it had to be done as a second step, after the catchpoint had been
1141 created, using the "condition" command.
1143 * The "info static-tracepoint-marker" command will now also work on
1144 native Linux targets with in-process agent.
1146 * GDB can now set breakpoints on inlined functions.
1148 * The .gdb_index section has been updated to include symbols for
1149 inlined functions. GDB will ignore older .gdb_index sections by
1150 default, which could cause symbol files to be loaded more slowly
1151 until their .gdb_index sections can be recreated. The new command
1152 "set use-deprecated-index-sections on" will cause GDB to use any older
1153 .gdb_index sections it finds. This will restore performance, but the
1154 ability to set breakpoints on inlined functions will be lost in symbol
1155 files with older .gdb_index sections.
1157 The .gdb_index section has also been updated to record more information
1158 about each symbol. This speeds up the "info variables", "info functions"
1159 and "info types" commands when used with programs having the .gdb_index
1160 section, as well as speeding up debugging with shared libraries using
1161 the .gdb_index section.
1163 * Ada support for GDB/MI Variable Objects has been added.
1165 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1170 ** New command -info-os is the MI equivalent of "info os".
1172 ** Output logs ("set logging" and related) now include MI output.
1176 ** "set use-deprecated-index-sections on|off"
1177 "show use-deprecated-index-sections on|off"
1178 Controls the use of deprecated .gdb_index sections.
1180 ** "catch load" and "catch unload" can be used to stop when a shared
1181 library is loaded or unloaded, respectively.
1183 ** "enable count" can be used to auto-disable a breakpoint after
1186 ** "info vtbl" can be used to show the virtual method tables for
1187 C++ and Java objects.
1189 ** "explore" and its sub commands "explore value" and "explore type"
1190 can be used to recursively explore values and types of
1191 expressions. These commands are available only if GDB is
1192 configured with '--with-python'.
1194 ** "info auto-load" shows status of all kinds of auto-loaded files,
1195 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1196 sequences of commands files, "info auto-load python-scripts"
1197 shows status of auto-loading Python script files,
1198 "info auto-load local-gdbinit" shows status of loading init file
1199 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1200 status of inferior specific thread debugging shared library loading.
1202 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1203 and "show auto-load-scripts" commands have been deprecated, use their
1204 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1205 and "show auto-load python-scripts" counterparts instead.
1207 ** "dprintf location,format,args..." creates a dynamic printf, which
1208 is basically a breakpoint that does a printf and immediately
1209 resumes your program's execution, so it is like a printf that you
1210 can insert dynamically at runtime instead of at compiletime.
1212 ** "set print symbol"
1214 Controls whether GDB attempts to display the symbol, if any,
1215 corresponding to addresses it prints. This defaults to "on", but
1216 you can set it to "off" to restore GDB's previous behavior.
1218 * Deprecated commands
1220 ** For the Renesas Super-H architecture, the "regs" command has been
1221 deprecated, and "info all-registers" should be used instead.
1225 Renesas RL78 rl78-*-elf
1226 HP OpenVMS ia64 ia64-hp-openvms*
1228 * GDBserver supports evaluation of breakpoint conditions. When
1229 support is advertised by GDBserver, GDB may be told to send the
1230 breakpoint conditions in bytecode form to GDBserver. GDBserver
1231 will only report the breakpoint trigger to GDB when its condition
1236 set mips compression
1237 show mips compression
1238 Select the compressed ISA encoding used in functions that have no symbol
1239 information available. The encoding can be set to either of:
1242 and is updated automatically from ELF file flags if available.
1244 set breakpoint condition-evaluation
1245 show breakpoint condition-evaluation
1246 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1247 GDBserver ("target"). Default option "auto" chooses the most efficient
1249 This option can improve debugger efficiency depending on the speed of the
1253 Disable auto-loading globally.
1256 Show auto-loading setting of all kinds of auto-loaded files.
1258 set auto-load gdb-scripts on|off
1259 show auto-load gdb-scripts
1260 Control auto-loading of GDB canned sequences of commands files.
1262 set auto-load python-scripts on|off
1263 show auto-load python-scripts
1264 Control auto-loading of Python script files.
1266 set auto-load local-gdbinit on|off
1267 show auto-load local-gdbinit
1268 Control loading of init file (.gdbinit) from current directory.
1270 set auto-load libthread-db on|off
1271 show auto-load libthread-db
1272 Control auto-loading of inferior specific thread debugging shared library.
1274 set auto-load scripts-directory <dir1>[:<dir2>...]
1275 show auto-load scripts-directory
1276 Set a list of directories from which to load auto-loaded scripts.
1277 Automatically loaded Python scripts and GDB scripts are located in one
1278 of the directories listed by this option.
1279 The delimiter (':' above) may differ according to the host platform.
1281 set auto-load safe-path <dir1>[:<dir2>...]
1282 show auto-load safe-path
1283 Set a list of directories from which it is safe to auto-load files.
1284 The delimiter (':' above) may differ according to the host platform.
1286 set debug auto-load on|off
1287 show debug auto-load
1288 Control display of debugging info for auto-loading the files above.
1290 set dprintf-style gdb|call|agent
1292 Control the way in which a dynamic printf is performed; "gdb"
1293 requests a GDB printf command, while "call" causes dprintf to call a
1294 function in the inferior. "agent" requests that the target agent
1295 (such as GDBserver) do the printing.
1297 set dprintf-function <expr>
1298 show dprintf-function
1299 set dprintf-channel <expr>
1300 show dprintf-channel
1301 Set the function and optional first argument to the call when using
1302 the "call" style of dynamic printf.
1304 set disconnected-dprintf on|off
1305 show disconnected-dprintf
1306 Control whether agent-style dynamic printfs continue to be in effect
1307 after GDB disconnects.
1309 * New configure options
1311 --with-auto-load-dir
1312 Configure default value for the 'set auto-load scripts-directory'
1313 setting above. It defaults to '$debugdir:$datadir/auto-load',
1314 $debugdir representing global debugging info directories (available
1315 via 'show debug-file-directory') and $datadir representing GDB's data
1316 directory (available via 'show data-directory').
1318 --with-auto-load-safe-path
1319 Configure default value for the 'set auto-load safe-path' setting
1320 above. It defaults to the --with-auto-load-dir setting.
1322 --without-auto-load-safe-path
1323 Set 'set auto-load safe-path' to '/', effectively disabling this
1326 * New remote packets
1328 z0/z1 conditional breakpoints extension
1330 The z0/z1 breakpoint insertion packets have been extended to carry
1331 a list of conditional expressions over to the remote stub depending on the
1332 condition evaluation mode. The use of this extension can be controlled
1333 via the "set remote conditional-breakpoints-packet" command.
1337 Specify the signals which the remote stub may pass to the debugged
1338 program without GDB involvement.
1340 * New command line options
1342 --init-command=FILE, -ix Like --command, -x but execute it
1343 before loading inferior.
1344 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1345 execute it before loading inferior.
1347 *** Changes in GDB 7.4
1349 * GDB now handles ambiguous linespecs more consistently; the existing
1350 FILE:LINE support has been expanded to other types of linespecs. A
1351 breakpoint will now be set on all matching locations in all
1352 inferiors, and locations will be added or removed according to
1355 * GDB now allows you to skip uninteresting functions and files when
1356 stepping with the "skip function" and "skip file" commands.
1358 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1359 and "show remote hardware-watchpoint-length-limit". These allows to
1360 set or show the maximum length limit (in bytes) of a remote
1361 target hardware watchpoint.
1363 This allows e.g. to use "unlimited" hardware watchpoints with the
1364 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1365 watchpoints are slower than real hardware watchpoints but are
1366 significantly faster than gdb software watchpoints.
1370 ** The register_pretty_printer function in module gdb.printing now takes
1371 an optional `replace' argument. If True, the new printer replaces any
1374 ** The "maint set python print-stack on|off" command has been
1375 deprecated and will be deleted in GDB 7.5.
1376 A new command: "set python print-stack none|full|message" has
1377 replaced it. Additionally, the default for "print-stack" is
1378 now "message", which just prints the error message without
1381 ** A prompt substitution hook (prompt_hook) is now available to the
1384 ** A new Python module, gdb.prompt has been added to the GDB Python
1385 modules library. This module provides functionality for
1386 escape sequences in prompts (used by set/show
1387 extended-prompt). These escape sequences are replaced by their
1388 corresponding value.
1390 ** Python commands and convenience-functions located in
1391 'data-directory'/python/gdb/command and
1392 'data-directory'/python/gdb/function are now automatically loaded
1395 ** Blocks now provide four new attributes. global_block and
1396 static_block will return the global and static blocks
1397 respectively. is_static and is_global are boolean attributes
1398 that indicate if the block is one of those two types.
1400 ** Symbols now provide the "type" attribute, the type of the symbol.
1402 ** The "gdb.breakpoint" function has been deprecated in favor of
1405 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1406 of a function. This class is based on the "finish" command
1407 available in the CLI.
1409 ** Type objects for struct and union types now allow access to
1410 the fields using standard Python dictionary (mapping) methods.
1411 For example, "some_type['myfield']" now works, as does
1412 "some_type.items()".
1414 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1417 ** A new function, "deep_items" has been added to the gdb.types
1418 module in the GDB Python modules library. This function returns
1419 an iterator over the fields of a struct or union type. Unlike
1420 the standard Python "iteritems" method, it will recursively traverse
1421 any anonymous fields.
1425 ** "*stopped" events can report several new "reason"s, such as
1428 ** Breakpoint changes are now notified using new async records, like
1429 "=breakpoint-modified".
1431 ** New command -ada-task-info.
1433 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1434 $sdir specifies the default system locations of shared libraries.
1435 $pdir specifies the directory where the libpthread used by the application
1438 GDB no longer looks in $sdir and $pdir after it has searched the directories
1439 mentioned in libthread-db-search-path. If you want to search those
1440 directories, they must be specified in libthread-db-search-path.
1441 The default value of libthread-db-search-path on GNU/Linux and Solaris
1442 systems is now "$sdir:$pdir".
1444 $pdir is not supported by gdbserver, it is currently ignored.
1445 $sdir is supported by gdbserver.
1447 * New configure option --with-iconv-bin.
1448 When using the internationalization support like the one in the GNU C
1449 library, GDB will invoke the "iconv" program to get a list of supported
1450 character sets. If this program lives in a non-standard location, one can
1451 use this option to specify where to find it.
1453 * When natively debugging programs on PowerPC BookE processors running
1454 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1455 watchpoints, which specify a mask in addition to an address to watch.
1456 The mask specifies that some bits of an address (the bits which are
1457 reset in the mask) should be ignored when matching the address accessed
1458 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1459 section in the user manual for more details.
1461 * The new option --once causes GDBserver to stop listening for connections once
1462 the first connection is made. The listening port used by GDBserver will
1463 become available after that.
1465 * New commands "info macros" and "alias" have been added.
1467 * New function parameters suffix @entry specifies value of function parameter
1468 at the time the function got called. Entry values are available only since
1474 "!" is now an alias of the "shell" command.
1475 Note that no space is needed between "!" and SHELL COMMAND.
1479 watch EXPRESSION mask MASK_VALUE
1480 The watch command now supports the mask argument which allows creation
1481 of masked watchpoints, if the current architecture supports this feature.
1483 info auto-load-scripts [REGEXP]
1484 This command was formerly named "maintenance print section-scripts".
1485 It is now generally useful and is no longer a maintenance-only command.
1487 info macro [-all] [--] MACRO
1488 The info macro command has new options `-all' and `--'. The first for
1489 printing all definitions of a macro. The second for explicitly specifying
1490 the end of arguments and the beginning of the macro name in case the macro
1491 name starts with a hyphen.
1493 collect[/s] EXPRESSIONS
1494 The tracepoint collect command now takes an optional modifier "/s"
1495 that directs it to dereference pointer-to-character types and
1496 collect the bytes of memory up to a zero byte. The behavior is
1497 similar to what you see when you use the regular print command on a
1498 string. An optional integer following the "/s" sets a bound on the
1499 number of bytes that will be collected.
1502 The trace start command now interprets any supplied arguments as a
1503 note to be recorded with the trace run, with an effect similar to
1504 setting the variable trace-notes.
1507 The trace stop command now interprets any arguments as a note to be
1508 mentioned along with the tstatus report that the trace was stopped
1509 with a command. The effect is similar to setting the variable
1512 * Tracepoints can now be enabled and disabled at any time after a trace
1513 experiment has been started using the standard "enable" and "disable"
1514 commands. It is now possible to start a trace experiment with no enabled
1515 tracepoints; GDB will display a warning, but will allow the experiment to
1516 begin, assuming that tracepoints will be enabled as needed while the trace
1519 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1520 locations with 4-byte instructions, when they were previously
1521 limited to locations with instructions of 5 bytes or longer.
1525 set debug dwarf2-read
1526 show debug dwarf2-read
1527 Turns on or off display of debugging messages related to reading
1528 DWARF debug info. The default is off.
1530 set debug symtab-create
1531 show debug symtab-create
1532 Turns on or off display of debugging messages related to symbol table
1533 creation. The default is off.
1536 show extended-prompt
1537 Set the GDB prompt, and allow escape sequences to be inserted to
1538 display miscellaneous information (see 'help set extended-prompt'
1539 for the list of sequences). This prompt (and any information
1540 accessed through the escape sequences) is updated every time the
1541 prompt is displayed.
1543 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1544 show print entry-values
1545 Set printing of frame argument values at function entry. In some cases
1546 GDB can determine the value of function argument which was passed by the
1547 function caller, even if the value was modified inside the called function.
1549 set debug entry-values
1550 show debug entry-values
1551 Control display of debugging info for determining frame argument values at
1552 function entry and virtual tail call frames.
1554 set basenames-may-differ
1555 show basenames-may-differ
1556 Set whether a source file may have multiple base names.
1557 (A "base name" is the name of a file with the directory part removed.
1558 Example: The base name of "/home/user/hello.c" is "hello.c".)
1559 If set, GDB will canonicalize file names (e.g., expand symlinks)
1560 before comparing them. Canonicalization is an expensive operation,
1561 but it allows the same file be known by more than one base name.
1562 If not set (the default), all source files are assumed to have just
1563 one base name, and gdb will do file name comparisons more efficiently.
1569 Set a user name and notes for the current and any future trace runs.
1570 This is useful for long-running and/or disconnected traces, to
1571 inform others (or yourself) as to who is running the trace, supply
1572 contact information, or otherwise explain what is going on.
1574 set trace-stop-notes
1575 show trace-stop-notes
1576 Set a note attached to the trace run, that is displayed when the
1577 trace has been stopped by a tstop command. This is useful for
1578 instance as an explanation, if you are stopping a trace run that was
1579 started by someone else.
1581 * New remote packets
1585 Dynamically enable a tracepoint in a started trace experiment.
1589 Dynamically disable a tracepoint in a started trace experiment.
1593 Set the user and notes of the trace run.
1597 Query the current status of a tracepoint.
1601 Query the minimum length of instruction at which a fast tracepoint may
1604 * Dcache size (number of lines) and line-size are now runtime-configurable
1605 via "set dcache line" and "set dcache line-size" commands.
1609 Texas Instruments TMS320C6x tic6x-*-*
1613 Renesas RL78 rl78-*-elf
1615 *** Changes in GDB 7.3.1
1617 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1619 *** Changes in GDB 7.3
1621 * GDB has a new command: "thread find [REGEXP]".
1622 It finds the thread id whose name, target id, or thread extra info
1623 matches the given regular expression.
1625 * The "catch syscall" command now works on mips*-linux* targets.
1627 * The -data-disassemble MI command now supports modes 2 and 3 for
1628 dumping the instruction opcodes.
1630 * New command line options
1632 -data-directory DIR Specify DIR as the "data-directory".
1633 This is mostly for testing purposes.
1635 * The "maint set python auto-load on|off" command has been renamed to
1636 "set auto-load-scripts on|off".
1638 * GDB has a new command: "set directories".
1639 It is like the "dir" command except that it replaces the
1640 source path list instead of augmenting it.
1642 * GDB now understands thread names.
1644 On GNU/Linux, "info threads" will display the thread name as set by
1645 prctl or pthread_setname_np.
1647 There is also a new command, "thread name", which can be used to
1648 assign a name internally for GDB to display.
1651 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1652 has been integrated into GDB.
1656 ** The function gdb.Write now accepts an optional keyword 'stream'.
1657 This keyword, when provided, will direct the output to either
1658 stdout, stderr, or GDB's logging output.
1660 ** Parameters can now be be sub-classed in Python, and in particular
1661 you may implement the get_set_doc and get_show_doc functions.
1662 This improves how Parameter set/show documentation is processed
1663 and allows for more dynamic content.
1665 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1666 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1667 have an is_valid method.
1669 ** Breakpoints can now be sub-classed in Python, and in particular
1670 you may implement a 'stop' function that is executed each time
1671 the inferior reaches that breakpoint.
1673 ** New function gdb.lookup_global_symbol looks up a global symbol.
1675 ** GDB values in Python are now callable if the value represents a
1676 function. For example, if 'some_value' represents a function that
1677 takes two integer parameters and returns a value, you can call
1678 that function like so:
1680 result = some_value (10,20)
1682 ** Module gdb.types has been added.
1683 It contains a collection of utilities for working with gdb.Types objects:
1684 get_basic_type, has_field, make_enum_dict.
1686 ** Module gdb.printing has been added.
1687 It contains utilities for writing and registering pretty-printers.
1688 New classes: PrettyPrinter, SubPrettyPrinter,
1689 RegexpCollectionPrettyPrinter.
1690 New function: register_pretty_printer.
1692 ** New commands "info pretty-printers", "enable pretty-printer" and
1693 "disable pretty-printer" have been added.
1695 ** gdb.parameter("directories") is now available.
1697 ** New function gdb.newest_frame returns the newest frame in the
1700 ** The gdb.InferiorThread class has a new "name" attribute. This
1701 holds the thread's name.
1703 ** Python Support for Inferior events.
1704 Python scripts can add observers to be notified of events
1705 occurring in the process being debugged.
1706 The following events are currently supported:
1707 - gdb.events.cont Continue event.
1708 - gdb.events.exited Inferior exited event.
1709 - gdb.events.stop Signal received, and Breakpoint hit events.
1713 ** GDB now puts template parameters in scope when debugging in an
1714 instantiation. For example, if you have:
1716 template<int X> int func (void) { return X; }
1718 then if you step into func<5>, "print X" will show "5". This
1719 feature requires proper debuginfo support from the compiler; it
1720 was added to GCC 4.5.
1722 ** The motion commands "next", "finish", "until", and "advance" now
1723 work better when exceptions are thrown. In particular, GDB will
1724 no longer lose control of the inferior; instead, the GDB will
1725 stop the inferior at the point at which the exception is caught.
1726 This functionality requires a change in the exception handling
1727 code that was introduced in GCC 4.5.
1729 * GDB now follows GCC's rules on accessing volatile objects when
1730 reading or writing target state during expression evaluation.
1731 One notable difference to prior behavior is that "print x = 0"
1732 no longer generates a read of x; the value of the assignment is
1733 now always taken directly from the value being assigned.
1735 * GDB now has some support for using labels in the program's source in
1736 linespecs. For instance, you can use "advance label" to continue
1737 execution to a label.
1739 * GDB now has support for reading and writing a new .gdb_index
1740 section. This section holds a fast index of DWARF debugging
1741 information and can be used to greatly speed up GDB startup and
1742 operation. See the documentation for `save gdb-index' for details.
1744 * The "watch" command now accepts an optional "-location" argument.
1745 When used, this causes GDB to watch the memory referred to by the
1746 expression. Such a watchpoint is never deleted due to it going out
1749 * GDB now supports thread debugging of core dumps on GNU/Linux.
1751 GDB now activates thread debugging using the libthread_db library
1752 when debugging GNU/Linux core dumps, similarly to when debugging
1753 live processes. As a result, when debugging a core dump file, GDB
1754 is now able to display pthread_t ids of threads. For example, "info
1755 threads" shows the same output as when debugging the process when it
1756 was live. In earlier releases, you'd see something like this:
1759 * 1 LWP 6780 main () at main.c:10
1761 While now you see this:
1764 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1766 It is also now possible to inspect TLS variables when debugging core
1769 When debugging a core dump generated on a machine other than the one
1770 used to run GDB, you may need to point GDB at the correct
1771 libthread_db library with the "set libthread-db-search-path"
1772 command. See the user manual for more details on this command.
1774 * When natively debugging programs on PowerPC BookE processors running
1775 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1776 which stop execution of the inferior whenever it executes an instruction
1777 at any address within the specified range. See the "PowerPC Embedded"
1778 section in the user manual for more details.
1780 * New features in the GDB remote stub, GDBserver
1782 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1783 and i686 LynxOS (version 5.x).
1785 ** GDBserver is now supported on Blackfin Linux.
1787 * New native configurations
1789 ia64 HP-UX ia64-*-hpux*
1793 Analog Devices, Inc. Blackfin Processor bfin-*
1795 * Ada task switching is now supported on sparc-elf targets when
1796 debugging a program using the Ravenscar Profile. For more information,
1797 see the "Tasking Support when using the Ravenscar Profile" section
1798 in the GDB user manual.
1800 * Guile support was removed.
1802 * New features in the GNU simulator
1804 ** The --map-info flag lists all known core mappings.
1806 ** CFI flashes may be simulated via the "cfi" device.
1808 *** Changes in GDB 7.2
1810 * Shared library support for remote targets by default
1812 When GDB is configured for a generic, non-OS specific target, like
1813 for example, --target=arm-eabi or one of the many *-*-elf targets,
1814 GDB now queries remote stubs for loaded shared libraries using the
1815 `qXfer:libraries:read' packet. Previously, shared library support
1816 was always disabled for such configurations.
1820 ** Argument Dependent Lookup (ADL)
1822 In C++ ADL lookup directs function search to the namespaces of its
1823 arguments even if the namespace has not been imported.
1833 Here the compiler will search for `foo' in the namespace of 'b'
1834 and find A::foo. GDB now supports this. This construct is commonly
1835 used in the Standard Template Library for operators.
1837 ** Improved User Defined Operator Support
1839 In addition to member operators, GDB now supports lookup of operators
1840 defined in a namespace and imported with a `using' directive, operators
1841 defined in the global scope, operators imported implicitly from an
1842 anonymous namespace, and the ADL operators mentioned in the previous
1844 GDB now also supports proper overload resolution for all the previously
1845 mentioned flavors of operators.
1847 ** static const class members
1849 Printing of static const class members that are initialized in the
1850 class definition has been fixed.
1852 * Windows Thread Information Block access.
1854 On Windows targets, GDB now supports displaying the Windows Thread
1855 Information Block (TIB) structure. This structure is visible either
1856 by using the new command `info w32 thread-information-block' or, by
1857 dereferencing the new convenience variable named `$_tlb', a
1858 thread-specific pointer to the TIB. This feature is also supported
1859 when remote debugging using GDBserver.
1861 * Static tracepoints
1863 Static tracepoints are calls in the user program into a tracing
1864 library. One such library is a port of the LTTng kernel tracer to
1865 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1866 When debugging with GDBserver, GDB now supports combining the GDB
1867 tracepoint machinery with such libraries. For example: the user can
1868 use GDB to probe a static tracepoint marker (a call from the user
1869 program into the tracing library) with the new "strace" command (see
1870 "New commands" below). This creates a "static tracepoint" in the
1871 breakpoint list, that can be manipulated with the same feature set
1872 as fast and regular tracepoints. E.g., collect registers, local and
1873 global variables, collect trace state variables, and define
1874 tracepoint conditions. In addition, the user can collect extra
1875 static tracepoint marker specific data, by collecting the new
1876 $_sdata internal variable. When analyzing the trace buffer, you can
1877 inspect $_sdata like any other variable available to GDB. For more
1878 information, see the "Tracepoints" chapter in GDB user manual. New
1879 remote packets have been defined to support static tracepoints, see
1880 the "New remote packets" section below.
1882 * Better reconstruction of tracepoints after disconnected tracing
1884 GDB will attempt to download the original source form of tracepoint
1885 definitions when starting a trace run, and then will upload these
1886 upon reconnection to the target, resulting in a more accurate
1887 reconstruction of the tracepoints that are in use on the target.
1891 You can now exercise direct control over the ways that GDB can
1892 affect your program. For instance, you can disallow the setting of
1893 breakpoints, so that the program can run continuously (assuming
1894 non-stop mode). In addition, the "observer" variable is available
1895 to switch all of the different controls; in observer mode, GDB
1896 cannot affect the target's behavior at all, which is useful for
1897 tasks like diagnosing live systems in the field.
1899 * The new convenience variable $_thread holds the number of the
1902 * New remote packets
1906 Return the address of the Windows Thread Information Block of a given thread.
1910 In response to several of the tracepoint packets, the target may now
1911 also respond with a number of intermediate `qRelocInsn' request
1912 packets before the final result packet, to have GDB handle
1913 relocating an instruction to execute at a different address. This
1914 is particularly useful for stubs that support fast tracepoints. GDB
1915 reports support for this feature in the qSupported packet.
1919 List static tracepoint markers in the target program.
1923 List static tracepoint markers at a given address in the target
1926 qXfer:statictrace:read
1928 Read the static trace data collected (by a `collect $_sdata'
1929 tracepoint action). The remote stub reports support for this packet
1930 to gdb's qSupported query.
1934 Send the current settings of GDB's permission flags.
1938 Send part of the source (textual) form of a tracepoint definition,
1939 which includes location, conditional, and action list.
1941 * The source command now accepts a -s option to force searching for the
1942 script in the source search path even if the script name specifies
1945 * New features in the GDB remote stub, GDBserver
1947 - GDBserver now support tracepoints (including fast tracepoints, and
1948 static tracepoints). The feature is currently supported by the
1949 i386-linux and amd64-linux builds. See the "Tracepoints support
1950 in gdbserver" section in the manual for more information.
1952 GDBserver JIT compiles the tracepoint's conditional agent
1953 expression bytecode into native code whenever possible for low
1954 overhead dynamic tracepoints conditionals. For such tracepoints,
1955 an expression that examines program state is evaluated when the
1956 tracepoint is reached, in order to determine whether to capture
1957 trace data. If the condition is simple and false, processing the
1958 tracepoint finishes very quickly and no data is gathered.
1960 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1961 for static tracepoints support.
1963 - GDBserver now supports x86_64 Windows 64-bit debugging.
1965 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1966 it understands register description.
1968 * The --batch flag now disables pagination and queries.
1970 * X86 general purpose registers
1972 GDB now supports reading/writing byte, word and double-word x86
1973 general purpose registers directly. This means you can use, say,
1974 $ah or $ax to refer, respectively, to the byte register AH and
1975 16-bit word register AX that are actually portions of the 32-bit
1976 register EAX or 64-bit register RAX.
1978 * The `commands' command now accepts a range of breakpoints to modify.
1979 A plain `commands' following a command that creates multiple
1980 breakpoints affects all the breakpoints set by that command. This
1981 applies to breakpoints set by `rbreak', and also applies when a
1982 single `break' command creates multiple breakpoints (e.g.,
1983 breakpoints on overloaded c++ functions).
1985 * The `rbreak' command now accepts a filename specification as part of
1986 its argument, limiting the functions selected by the regex to those
1987 in the specified file.
1989 * Support for remote debugging Windows and SymbianOS shared libraries
1990 from Unix hosts has been improved. Non Windows GDB builds now can
1991 understand target reported file names that follow MS-DOS based file
1992 system semantics, such as file names that include drive letters and
1993 use the backslash character as directory separator. This makes it
1994 possible to transparently use the "set sysroot" and "set
1995 solib-search-path" on Unix hosts to point as host copies of the
1996 target's shared libraries. See the new command "set
1997 target-file-system-kind" described below, and the "Commands to
1998 specify files" section in the user manual for more information.
2002 eval template, expressions...
2003 Convert the values of one or more expressions under the control
2004 of the string template to a command line, and call it.
2006 set target-file-system-kind unix|dos-based|auto
2007 show target-file-system-kind
2008 Set or show the assumed file system kind for target reported file
2011 save breakpoints <filename>
2012 Save all current breakpoint definitions to a file suitable for use
2013 in a later debugging session. To read the saved breakpoint
2014 definitions, use the `source' command.
2016 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2019 info static-tracepoint-markers
2020 Display information about static tracepoint markers in the target.
2022 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2023 Define a static tracepoint by probing a marker at the given
2024 function, line, address, or marker ID.
2028 Enable and disable observer mode.
2030 set may-write-registers on|off
2031 set may-write-memory on|off
2032 set may-insert-breakpoints on|off
2033 set may-insert-tracepoints on|off
2034 set may-insert-fast-tracepoints on|off
2035 set may-interrupt on|off
2036 Set individual permissions for GDB effects on the target. Note that
2037 some of these settings can have undesirable or surprising
2038 consequences, particularly when changed in the middle of a session.
2039 For instance, disabling the writing of memory can prevent
2040 breakpoints from being inserted, cause single-stepping to fail, or
2041 even crash your program, if you disable after breakpoints have been
2042 inserted. However, GDB should not crash.
2044 set record memory-query on|off
2045 show record memory-query
2046 Control whether to stop the inferior if memory changes caused
2047 by an instruction cannot be recorded.
2052 The disassemble command now supports "start,+length" form of two arguments.
2056 ** GDB now provides a new directory location, called the python directory,
2057 where Python scripts written for GDB can be installed. The location
2058 of that directory is <data-directory>/python, where <data-directory>
2059 is the GDB data directory. For more details, see section `Scripting
2060 GDB using Python' in the manual.
2062 ** The GDB Python API now has access to breakpoints, symbols, symbol
2063 tables, program spaces, inferiors, threads and frame's code blocks.
2064 Additionally, GDB Parameters can now be created from the API, and
2065 manipulated via set/show in the CLI.
2067 ** New functions gdb.target_charset, gdb.target_wide_charset,
2068 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2070 ** New exception gdb.GdbError.
2072 ** Pretty-printers are now also looked up in the current program space.
2074 ** Pretty-printers can now be individually enabled and disabled.
2076 ** GDB now looks for names of Python scripts to auto-load in a
2077 special section named `.debug_gdb_scripts', in addition to looking
2078 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2080 * Tracepoint actions were unified with breakpoint commands. In particular,
2081 there are no longer differences in "info break" output for breakpoints and
2082 tracepoints and the "commands" command can be used for both tracepoints and
2083 regular breakpoints.
2087 ARM Symbian arm*-*-symbianelf*
2089 * D language support.
2090 GDB now supports debugging programs written in the D programming
2093 * GDB now supports the extended ptrace interface for PowerPC which is
2094 available since Linux kernel version 2.6.34. This automatically enables
2095 any hardware breakpoints and additional hardware watchpoints available in
2096 the processor. The old ptrace interface exposes just one hardware
2097 watchpoint and no hardware breakpoints.
2099 * GDB is now able to use the Data Value Compare (DVC) register available on
2100 embedded PowerPC processors to implement in hardware simple watchpoint
2101 conditions of the form:
2103 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2105 This works in native GDB running on Linux kernels with the extended ptrace
2106 interface mentioned above.
2108 *** Changes in GDB 7.1
2112 ** Namespace Support
2114 GDB now supports importing of namespaces in C++. This enables the
2115 user to inspect variables from imported namespaces. Support for
2116 namepace aliasing has also been added. So, if a namespace is
2117 aliased in the current scope (e.g. namepace C=A; ) the user can
2118 print variables using the alias (e.g. (gdb) print C::x).
2122 All known bugs relating to the printing of virtual base class were
2123 fixed. It is now possible to call overloaded static methods using a
2128 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2129 and reinterpret_cast<> are now handled by the C++ expression parser.
2133 Xilinx MicroBlaze microblaze-*-*
2138 Xilinx MicroBlaze microblaze
2141 * Multi-program debugging.
2143 GDB now has support for multi-program (a.k.a. multi-executable or
2144 multi-exec) debugging. This allows for debugging multiple inferiors
2145 simultaneously each running a different program under the same GDB
2146 session. See "Debugging Multiple Inferiors and Programs" in the
2147 manual for more information. This implied some user visible changes
2148 in the multi-inferior support. For example, "info inferiors" now
2149 lists inferiors that are not running yet or that have exited
2150 already. See also "New commands" and "New options" below.
2152 * New tracing features
2154 GDB's tracepoint facility now includes several new features:
2156 ** Trace state variables
2158 GDB tracepoints now include support for trace state variables, which
2159 are variables managed by the target agent during a tracing
2160 experiment. They are useful for tracepoints that trigger each
2161 other, so for instance one tracepoint can count hits in a variable,
2162 and then a second tracepoint has a condition that is true when the
2163 count reaches a particular value. Trace state variables share the
2164 $-syntax of GDB convenience variables, and can appear in both
2165 tracepoint actions and condition expressions. Use the "tvariable"
2166 command to create, and "info tvariables" to view; see "Trace State
2167 Variables" in the manual for more detail.
2171 GDB now includes an option for defining fast tracepoints, which
2172 targets may implement more efficiently, such as by installing a jump
2173 into the target agent rather than a trap instruction. The resulting
2174 speedup can be by two orders of magnitude or more, although the
2175 tradeoff is that some program locations on some target architectures
2176 might not allow fast tracepoint installation, for instance if the
2177 instruction to be replaced is shorter than the jump. To request a
2178 fast tracepoint, use the "ftrace" command, with syntax identical to
2179 the regular trace command.
2181 ** Disconnected tracing
2183 It is now possible to detach GDB from the target while it is running
2184 a trace experiment, then reconnect later to see how the experiment
2185 is going. In addition, a new variable disconnected-tracing lets you
2186 tell the target agent whether to continue running a trace if the
2187 connection is lost unexpectedly.
2191 GDB now has the ability to save the trace buffer into a file, and
2192 then use that file as a target, similarly to you can do with
2193 corefiles. You can select trace frames, print data that was
2194 collected in them, and use tstatus to display the state of the
2195 tracing run at the moment that it was saved. To create a trace
2196 file, use "tsave <filename>", and to use it, do "target tfile
2199 ** Circular trace buffer
2201 You can ask the target agent to handle the trace buffer as a
2202 circular buffer, discarding the oldest trace frames to make room for
2203 newer ones, by setting circular-trace-buffer to on. This feature may
2204 not be available for all target agents.
2209 The disassemble command, when invoked with two arguments, now requires
2210 the arguments to be comma-separated.
2213 The info variables command now displays variable definitions. Files
2214 which only declare a variable are not shown.
2217 The source command is now capable of sourcing Python scripts.
2218 This feature is dependent on the debugger being build with Python
2221 Related to this enhancement is also the introduction of a new command
2222 "set script-extension" (see below).
2224 * New commands (for set/show, see "New options" below)
2226 record save [<FILENAME>]
2227 Save a file (in core file format) containing the process record
2228 execution log for replay debugging at a later time.
2230 record restore <FILENAME>
2231 Restore the process record execution log that was saved at an
2232 earlier time, for replay debugging.
2234 add-inferior [-copies <N>] [-exec <FILENAME>]
2237 clone-inferior [-copies <N>] [ID]
2238 Make a new inferior ready to execute the same program another
2239 inferior has loaded.
2244 maint info program-spaces
2245 List the program spaces loaded into GDB.
2247 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2248 show remote interrupt-sequence
2249 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2250 as the sequence to the remote target in order to interrupt the execution.
2251 Ctrl-C is a default. Some system prefers BREAK which is high level of
2252 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2253 Magic SysRq g. It is BREAK signal and character 'g'.
2255 set remote interrupt-on-connect [on | off]
2256 show remote interrupt-on-connect
2257 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2258 remote target when gdb connects to it. This is needed when you debug
2261 set remotebreak [on | off]
2263 Deprecated. Use "set/show remote interrupt-sequence" instead.
2265 tvariable $NAME [ = EXP ]
2266 Create or modify a trace state variable.
2269 List trace state variables and their values.
2271 delete tvariable $NAME ...
2272 Delete one or more trace state variables.
2275 Evaluate the given expressions without collecting anything into the
2276 trace buffer. (Valid in tracepoint actions only.)
2278 ftrace FN / FILE:LINE / *ADDR
2279 Define a fast tracepoint at the given function, line, or address.
2281 * New expression syntax
2283 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2284 GDB now parses 0b101010 identically with 42.
2288 set follow-exec-mode new|same
2289 show follow-exec-mode
2290 Control whether GDB reuses the same inferior across an exec call or
2291 creates a new one. This is useful to be able to restart the old
2292 executable after the inferior having done an exec call.
2294 set default-collect EXPR, ...
2295 show default-collect
2296 Define a list of expressions to be collected at each tracepoint.
2297 This is a useful way to ensure essential items are not overlooked,
2298 such as registers or a critical global variable.
2300 set disconnected-tracing
2301 show disconnected-tracing
2302 If set to 1, the target is instructed to continue tracing if it
2303 loses its connection to GDB. If 0, the target is to stop tracing
2306 set circular-trace-buffer
2307 show circular-trace-buffer
2308 If set to on, the target is instructed to use a circular trace buffer
2309 and discard the oldest trace frames instead of stopping the trace due
2310 to a full trace buffer. If set to off, the trace stops when the buffer
2311 fills up. Some targets may not support this.
2313 set script-extension off|soft|strict
2314 show script-extension
2315 If set to "off", the debugger does not perform any script language
2316 recognition, and all sourced files are assumed to be GDB scripts.
2317 If set to "soft" (the default), files are sourced according to
2318 filename extension, falling back to GDB scripts if the first
2320 If set to "strict", files are sourced according to filename extension.
2322 set ada trust-PAD-over-XVS on|off
2323 show ada trust-PAD-over-XVS
2324 If off, activate a workaround against a bug in the debugging information
2325 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2326 the GCC sources for more information about the GNAT encoding and
2327 PAD types in particular). It is always safe to set this option to
2328 off, but this introduces a slight performance penalty. The default
2331 * Python API Improvements
2333 ** GDB provides the new class gdb.LazyString. This is useful in
2334 some pretty-printing cases. The new method gdb.Value.lazy_string
2335 provides a simple way to create objects of this type.
2337 ** The fields returned by gdb.Type.fields now have an
2338 `is_base_class' attribute.
2340 ** The new method gdb.Type.range returns the range of an array type.
2342 ** The new method gdb.parse_and_eval can be used to parse and
2343 evaluate an expression.
2345 * New remote packets
2348 Define a trace state variable.
2351 Get the current value of a trace state variable.
2354 Set desired tracing behavior upon disconnection.
2357 Set the trace buffer to be linear or circular.
2360 Get data about the tracepoints currently in use.
2364 Process record now works correctly with hardware watchpoints.
2366 Multiple bug fixes have been made to the mips-irix port, making it
2367 much more reliable. In particular:
2368 - Debugging threaded applications is now possible again. Previously,
2369 GDB would hang while starting the program, or while waiting for
2370 the program to stop at a breakpoint.
2371 - Attaching to a running process no longer hangs.
2372 - An error occurring while loading a core file has been fixed.
2373 - Changing the value of the PC register now works again. This fixes
2374 problems observed when using the "jump" command, or when calling
2375 a function from GDB, or even when assigning a new value to $pc.
2376 - With the "finish" and "return" commands, the return value for functions
2377 returning a small array is now correctly printed.
2378 - It is now possible to break on shared library code which gets executed
2379 during a shared library init phase (code executed while executing
2380 their .init section). Previously, the breakpoint would have no effect.
2381 - GDB is now able to backtrace through the signal handler for
2382 non-threaded programs.
2384 PIE (Position Independent Executable) programs debugging is now supported.
2385 This includes debugging execution of PIC (Position Independent Code) shared
2386 libraries although for that, it should be possible to run such libraries as an
2389 *** Changes in GDB 7.0
2391 * GDB now has an interface for JIT compilation. Applications that
2392 dynamically generate code can create symbol files in memory and register
2393 them with GDB. For users, the feature should work transparently, and
2394 for JIT developers, the interface is documented in the GDB manual in the
2395 "JIT Compilation Interface" chapter.
2397 * Tracepoints may now be conditional. The syntax is as for
2398 breakpoints; either an "if" clause appended to the "trace" command,
2399 or the "condition" command is available. GDB sends the condition to
2400 the target for evaluation using the same bytecode format as is used
2401 for tracepoint actions.
2403 * The disassemble command now supports: an optional /r modifier, print the
2404 raw instructions in hex as well as in symbolic form, and an optional /m
2405 modifier to print mixed source+assembly.
2407 * Process record and replay
2409 In a architecture environment that supports ``process record and
2410 replay'', ``process record and replay'' target can record a log of
2411 the process execution, and replay it with both forward and reverse
2414 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2415 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2416 set execution-direction {forward|reverse}, for targets that support
2419 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2420 feature is available with a native GDB running on kernel version
2423 * GDB now has support for multi-byte and wide character sets on the
2424 target. Strings whose character type is wchar_t, char16_t, or
2425 char32_t are now correctly printed. GDB supports wide- and unicode-
2426 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2427 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2428 `printf'. This feature requires iconv to work properly; if your
2429 system does not have a working iconv, GDB can use GNU libiconv. See
2430 the installation instructions for more information.
2432 * GDB now supports automatic retrieval of shared library files from
2433 remote targets. To use this feature, specify a system root that begins
2434 with the `remote:' prefix, either via the `set sysroot' command or via
2435 the `--with-sysroot' configure-time option.
2437 * "info sharedlibrary" now takes an optional regex of libraries to show,
2438 and it now reports if a shared library has no debugging information.
2440 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2441 now complete on file names.
2443 * When completing in expressions, gdb will attempt to limit
2444 completions to allowable structure or union fields, where appropriate.
2445 For instance, consider:
2447 # struct example { int f1; double f2; };
2448 # struct example variable;
2451 If the user types TAB at the end of this command line, the available
2452 completions will be "f1" and "f2".
2454 * Inlined functions are now supported. They show up in backtraces, and
2455 the "step", "next", and "finish" commands handle them automatically.
2457 * GDB now supports the token-splicing (##) and stringification (#)
2458 operators when expanding macros. It also supports variable-arity
2461 * GDB now supports inspecting extra signal information, exported by
2462 the new $_siginfo convenience variable. The feature is currently
2463 implemented on linux ARM, i386 and amd64.
2465 * GDB can now display the VFP floating point registers and NEON vector
2466 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2467 can provide these registers (requires Linux 2.6.30 or later). Remote
2468 and simulator targets may also provide them.
2470 * New remote packets
2473 Search memory for a sequence of bytes.
2476 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2477 operation over reliable transport links. Use of this packet is
2478 controlled by the `set remote noack-packet' command.
2481 Kill the process with the specified process ID. Use this in preference
2482 to `k' when multiprocess protocol extensions are supported.
2485 Obtains additional operating system information
2489 Read or write additional signal information.
2491 * Removed remote protocol undocumented extension
2493 An undocumented extension to the remote protocol's `S' stop reply
2494 packet that permited the stub to pass a process id was removed.
2495 Remote servers should use the `T' stop reply packet instead.
2497 * GDB now supports multiple function calling conventions according to the
2498 DWARF-2 DW_AT_calling_convention function attribute.
2500 * The SH target utilizes the aforementioned change to distinguish between gcc
2501 and Renesas calling convention. It also adds the new CLI commands
2502 `set/show sh calling-convention'.
2504 * GDB can now read compressed debug sections, as produced by GNU gold
2505 with the --compress-debug-sections=zlib flag.
2507 * 64-bit core files are now supported on AIX.
2509 * Thread switching is now supported on Tru64.
2511 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2512 which will be allocated using malloc later in program execution.
2514 * The qXfer:libraries:read remote procotol packet now allows passing a
2515 list of section offsets.
2517 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2518 conditions handling signals delivered during attach or thread creation
2519 have also been fixed.
2521 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2522 From the user's standpoint, all unqualified instances of True and False
2523 are treated as the standard definitions, regardless of context.
2525 * GDB now parses C++ symbol and type names more flexibly. For
2528 template<typename T> class C { };
2531 GDB will now correctly handle all of:
2533 ptype C<char const *>
2534 ptype C<char const*>
2535 ptype C<const char *>
2536 ptype C<const char*>
2538 * New features in the GDB remote stub, gdbserver
2540 - The "--wrapper" command-line argument tells gdbserver to use a
2541 wrapper program to launch programs for debugging.
2543 - On PowerPC and S/390 targets, it is now possible to use a single
2544 gdbserver executable to debug both 32-bit and 64-bit programs.
2545 (This requires gdbserver itself to be built as a 64-bit executable.)
2547 - gdbserver uses the new noack protocol mode for TCP connections to
2548 reduce communications latency, if also supported and enabled in GDB.
2550 - Support for the sparc64-linux-gnu target is now included in
2553 - The amd64-linux build of gdbserver now supports debugging both
2554 32-bit and 64-bit programs.
2556 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2557 now support hardware watchpoints, and will use them automatically
2562 GDB now has support for scripting using Python. Whether this is
2563 available is determined at configure time.
2565 New GDB commands can now be written in Python.
2567 * Ada tasking support
2569 Ada tasks can now be inspected in GDB. The following commands have
2573 Print the list of Ada tasks.
2575 Print detailed information about task number N.
2577 Print the task number of the current task.
2579 Switch the context of debugging to task number N.
2581 * Support for user-defined prefixed commands. The "define" command can
2582 add new commands to existing prefixes, e.g. "target".
2584 * Multi-inferior, multi-process debugging.
2586 GDB now has generalized support for multi-inferior debugging. See
2587 "Debugging Multiple Inferiors" in the manual for more information.
2588 Although availability still depends on target support, the command
2589 set is more uniform now. The GNU/Linux specific multi-forks support
2590 has been migrated to this new framework. This implied some user
2591 visible changes; see "New commands" and also "Removed commands"
2594 * Target descriptions can now describe the target OS ABI. See the
2595 "Target Description Format" section in the user manual for more
2598 * Target descriptions can now describe "compatible" architectures
2599 to indicate that the target can execute applications for a different
2600 architecture in addition to those for the main target architecture.
2601 See the "Target Description Format" section in the user manual for
2604 * Multi-architecture debugging.
2606 GDB now includes general supports for debugging applications on
2607 hybrid systems that use more than one single processor architecture
2608 at the same time. Each such hybrid architecture still requires
2609 specific support to be added. The only hybrid architecture supported
2610 in this version of GDB is the Cell Broadband Engine.
2612 * GDB now supports integrated debugging of Cell/B.E. applications that
2613 use both the PPU and SPU architectures. To enable support for hybrid
2614 Cell/B.E. debugging, you need to configure GDB to support both the
2615 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2616 --enable-targets configure option.
2618 * Non-stop mode debugging.
2620 For some targets, GDB now supports an optional mode of operation in
2621 which you can examine stopped threads while other threads continue
2622 to execute freely. This is referred to as non-stop mode, with the
2623 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2624 section in the user manual for more information.
2626 To be able to support remote non-stop debugging, a remote stub needs
2627 to implement the non-stop mode remote protocol extensions, as
2628 described in the "Remote Non-Stop" section of the user manual. The
2629 GDB remote stub, gdbserver, has been adjusted to support these
2630 extensions on linux targets.
2632 * New commands (for set/show, see "New options" below)
2634 catch syscall [NAME(S) | NUMBER(S)]
2635 Catch system calls. Arguments, which should be names of system
2636 calls or their numbers, mean catch only those syscalls. Without
2637 arguments, every syscall will be caught. When the inferior issues
2638 any of the specified syscalls, GDB will stop and announce the system
2639 call, both when it is called and when its call returns. This
2640 feature is currently available with a native GDB running on the
2641 Linux Kernel, under the following architectures: x86, x86_64,
2642 PowerPC and PowerPC64.
2644 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2646 Search memory for a sequence of bytes.
2648 maint set python print-stack
2649 maint show python print-stack
2650 Show a stack trace when an error is encountered in a Python script.
2653 Invoke CODE by passing it to the Python interpreter.
2658 These allow macros to be defined, undefined, and listed
2662 Show operating system information about processes.
2665 List the inferiors currently under GDB's control.
2668 Switch focus to inferior number NUM.
2671 Detach from inferior number NUM.
2674 Kill inferior number NUM.
2678 set spu stop-on-load
2679 show spu stop-on-load
2680 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2682 set spu auto-flush-cache
2683 show spu auto-flush-cache
2684 Control whether to automatically flush the software-managed cache
2685 during Cell/B.E. debugging.
2687 set sh calling-convention
2688 show sh calling-convention
2689 Control the calling convention used when calling SH target functions.
2692 show debug timestamp
2693 Control display of timestamps with GDB debugging output.
2695 set disassemble-next-line
2696 show disassemble-next-line
2697 Control display of disassembled source lines or instructions when
2700 set remote noack-packet
2701 show remote noack-packet
2702 Set/show the use of remote protocol QStartNoAckMode packet. See above
2703 under "New remote packets."
2705 set remote query-attached-packet
2706 show remote query-attached-packet
2707 Control use of remote protocol `qAttached' (query-attached) packet.
2709 set remote read-siginfo-object
2710 show remote read-siginfo-object
2711 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2714 set remote write-siginfo-object
2715 show remote write-siginfo-object
2716 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2719 set remote reverse-continue
2720 show remote reverse-continue
2721 Control use of remote protocol 'bc' (reverse-continue) packet.
2723 set remote reverse-step
2724 show remote reverse-step
2725 Control use of remote protocol 'bs' (reverse-step) packet.
2727 set displaced-stepping
2728 show displaced-stepping
2729 Control displaced stepping mode. Displaced stepping is a way to
2730 single-step over breakpoints without removing them from the debuggee.
2731 Also known as "out-of-line single-stepping".
2734 show debug displaced
2735 Control display of debugging info for displaced stepping.
2737 maint set internal-error
2738 maint show internal-error
2739 Control what GDB does when an internal error is detected.
2741 maint set internal-warning
2742 maint show internal-warning
2743 Control what GDB does when an internal warning is detected.
2748 Use a wrapper program to launch programs for debugging.
2750 set multiple-symbols (all|ask|cancel)
2751 show multiple-symbols
2752 The value of this variable can be changed to adjust the debugger behavior
2753 when an expression or a breakpoint location contains an ambiguous symbol
2754 name (an overloaded function name, for instance).
2756 set breakpoint always-inserted
2757 show breakpoint always-inserted
2758 Keep breakpoints always inserted in the target, as opposed to inserting
2759 them when resuming the target, and removing them when the target stops.
2760 This option can improve debugger performance on slow remote targets.
2762 set arm fallback-mode (arm|thumb|auto)
2763 show arm fallback-mode
2764 set arm force-mode (arm|thumb|auto)
2766 These commands control how ARM GDB determines whether instructions
2767 are ARM or Thumb. The default for both settings is auto, which uses
2768 the current CPSR value for instructions without symbols; previous
2769 versions of GDB behaved as if "set arm fallback-mode arm".
2771 set disable-randomization
2772 show disable-randomization
2773 Standalone programs run with the virtual address space randomization enabled
2774 by default on some platforms. This option keeps the addresses stable across
2775 multiple debugging sessions.
2779 Control whether other threads are stopped or not when some thread hits
2784 Requests that asynchronous execution is enabled in the target, if available.
2785 In this case, it's possible to resume target in the background, and interact
2786 with GDB while the target is running. "show target-async" displays the
2787 current state of asynchronous execution of the target.
2789 set target-wide-charset
2790 show target-wide-charset
2791 The target-wide-charset is the name of the character set that GDB
2792 uses when printing characters whose type is wchar_t.
2794 set tcp auto-retry (on|off)
2796 set tcp connect-timeout
2797 show tcp connect-timeout
2798 These commands allow GDB to retry failed TCP connections to a remote stub
2799 with a specified timeout period; this is useful if the stub is launched
2800 in parallel with GDB but may not be ready to accept connections immediately.
2802 set libthread-db-search-path
2803 show libthread-db-search-path
2804 Control list of directories which GDB will search for appropriate
2807 set schedule-multiple (on|off)
2808 show schedule-multiple
2809 Allow GDB to resume all threads of all processes or only threads of
2810 the current process.
2814 Use more aggressive caching for accesses to the stack. This improves
2815 performance of remote debugging (particularly backtraces) without
2816 affecting correctness.
2818 set interactive-mode (on|off|auto)
2819 show interactive-mode
2820 Control whether GDB runs in interactive mode (on) or not (off).
2821 When in interactive mode, GDB waits for the user to answer all
2822 queries. Otherwise, GDB does not wait and assumes the default
2823 answer. When set to auto (the default), GDB determines which
2824 mode to use based on the stdin settings.
2829 For program forks, this is replaced by the new more generic `info
2830 inferiors' command. To list checkpoints, you can still use the
2831 `info checkpoints' command, which was an alias for the `info forks'
2835 Replaced by the new `inferior' command. To switch between
2836 checkpoints, you can still use the `restart' command, which was an
2837 alias for the `fork' command.
2840 This is removed, since some targets don't have a notion of
2841 processes. To switch between processes, you can still use the
2842 `inferior' command using GDB's own inferior number.
2845 For program forks, this is replaced by the new more generic `kill
2846 inferior' command. To delete a checkpoint, you can still use the
2847 `delete checkpoint' command, which was an alias for the `delete
2851 For program forks, this is replaced by the new more generic `detach
2852 inferior' command. To detach a checkpoint, you can still use the
2853 `detach checkpoint' command, which was an alias for the `detach
2856 * New native configurations
2858 x86/x86_64 Darwin i[34567]86-*-darwin*
2860 x86_64 MinGW x86_64-*-mingw*
2864 Lattice Mico32 lm32-*
2865 x86 DICOS i[34567]86-*-dicos*
2866 x86_64 DICOS x86_64-*-dicos*
2869 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2870 (mingw32ce) debugging.
2876 These commands were actually not implemented on any target.
2878 *** Changes in GDB 6.8
2880 * New native configurations
2882 NetBSD/hppa hppa*-*netbsd*
2883 Xtensa GNU/Linux xtensa*-*-linux*
2887 NetBSD/hppa hppa*-*-netbsd*
2888 Xtensa GNU/Lunux xtensa*-*-linux*
2890 * Change in command line behavior -- corefiles vs. process ids.
2892 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2893 attaching to process NUMBER fails, GDB no longer attempts to open a
2894 core file named NUMBER. Attaching to a program using the -c option
2895 is no longer supported. Instead, use the '-p' or '--pid' options.
2897 * GDB can now be built as a native debugger for debugging Windows x86
2898 (mingw32) Portable Executable (PE) programs.
2900 * Pending breakpoints no longer change their number when their address
2903 * GDB now supports breakpoints with multiple locations,
2904 including breakpoints on C++ constructors, inside C++ templates,
2905 and in inlined functions.
2907 * GDB's ability to debug optimized code has been improved. GDB more
2908 accurately identifies function bodies and lexical blocks that occupy
2909 more than one contiguous range of addresses.
2911 * Target descriptions can now describe registers for PowerPC.
2913 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2914 registers on PowerPC targets.
2916 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2917 targets even when the libthread_db library is not available.
2919 * The GDB remote stub, gdbserver, now supports the new file transfer
2920 commands (remote put, remote get, and remote delete).
2922 * The GDB remote stub, gdbserver, now supports run and attach in
2923 extended-remote mode.
2925 * hppa*64*-*-hpux11* target broken
2926 The debugger is unable to start a program and fails with the following
2927 error: "Error trying to get information about dynamic linker".
2928 The gdb-6.7 release is also affected.
2930 * GDB now supports the --enable-targets= configure option to allow
2931 building a single GDB executable that supports multiple remote
2932 target architectures.
2934 * GDB now supports debugging C and C++ programs which use the
2935 Decimal Floating Point extension. In addition, the PowerPC target
2936 now has a set of pseudo-registers to inspect decimal float values
2937 stored in two consecutive float registers.
2939 * The -break-insert MI command can optionally create pending
2942 * Improved support for debugging Ada
2943 Many improvements to the Ada language support have been made. These
2945 - Better support for Ada2005 interface types
2946 - Improved handling of arrays and slices in general
2947 - Better support for Taft-amendment types
2948 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2950 - Improved command completion in Ada
2953 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2958 set print frame-arguments (all|scalars|none)
2959 show print frame-arguments
2960 The value of this variable can be changed to control which argument
2961 values should be printed by the debugger when displaying a frame.
2966 Transfer files to and from a remote target, and delete remote files.
2973 Transfer files to and from a remote target, and delete remote files.
2975 * New remote packets
2982 Open, close, read, write, and delete files on the remote system.
2985 Attach to an existing process on the remote system, in extended-remote
2989 Run a new process on the remote system, in extended-remote mode.
2991 *** Changes in GDB 6.7
2993 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2994 bfd, libiberty and opcodes, as revealed by static analysis donated by
2995 Coverity, Inc. (http://scan.coverity.com).
2997 * When looking up multiply-defined global symbols, GDB will now prefer the
2998 symbol definition in the current shared library if it was built using the
2999 -Bsymbolic linker option.
3001 * When the Text User Interface (TUI) is not configured, GDB will now
3002 recognize the -tui command-line option and print a message that the TUI
3005 * The GDB remote stub, gdbserver, now has lower overhead for high
3006 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3008 * GDB for MIPS targets now autodetects whether a remote target provides
3009 32-bit or 64-bit register values.
3011 * Support for C++ member pointers has been improved.
3013 * GDB now understands XML target descriptions, which specify the
3014 target's overall architecture. GDB can read a description from
3015 a local file or over the remote serial protocol.
3017 * Vectors of single-byte data use a new integer type which is not
3018 automatically displayed as character or string data.
3020 * The /s format now works with the print command. It displays
3021 arrays of single-byte integers and pointers to single-byte integers
3024 * Target descriptions can now describe target-specific registers,
3025 for architectures which have implemented the support (currently
3026 only ARM, M68K, and MIPS).
3028 * GDB and the GDB remote stub, gdbserver, now support the XScale
3031 * The GDB remote stub, gdbserver, has been updated to support
3032 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3033 has been rewritten to use the standard GDB remote protocol.
3035 * GDB can now step into C++ functions which are called through thunks.
3037 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3039 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3040 layout. It also supports a TextSeg= and DataSeg= response when only
3041 segment base addresses (rather than offsets) are available.
3043 * The /i format now outputs any trailing branch delay slot instructions
3044 immediately following the last instruction within the count specified.
3046 * The GDB remote protocol "T" stop reply packet now supports a
3047 "library" response. Combined with the new "qXfer:libraries:read"
3048 packet, this response allows GDB to debug shared libraries on targets
3049 where the operating system manages the list of loaded libraries (e.g.
3050 Windows and SymbianOS).
3052 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3053 (DLLs) on Windows and Windows CE targets.
3055 * GDB now supports a faster verification that a .debug file matches its binary
3056 according to its build-id signature, if the signature is present.
3062 Enable or disable hardware flow control (RTS/CTS) on the serial port
3063 when debugging using remote targets.
3065 set mem inaccessible-by-default
3066 show mem inaccessible-by-default
3067 If the target supplies a memory map, for instance via the remote
3068 protocol's "qXfer:memory-map:read" packet, setting this variable
3069 prevents GDB from accessing memory outside the memory map. This
3070 is useful for targets with memory mapped registers or which react
3071 badly to accesses of unmapped address space.
3073 set breakpoint auto-hw
3074 show breakpoint auto-hw
3075 If the target supplies a memory map, for instance via the remote
3076 protocol's "qXfer:memory-map:read" packet, setting this variable
3077 lets GDB use hardware breakpoints automatically for memory regions
3078 where it can not use software breakpoints. This covers both the
3079 "break" command and internal breakpoints used for other commands
3080 including "next" and "finish".
3083 catch exception unhandled
3084 Stop the program execution when Ada exceptions are raised.
3087 Stop the program execution when an Ada assertion failed.
3091 Set an alternate system root for target files. This is a more
3092 general version of "set solib-absolute-prefix", which is now
3093 an alias to "set sysroot".
3096 Provide extended SPU facility status information. This set of
3097 commands is available only when debugging the Cell/B.E. SPU
3100 * New native configurations
3102 OpenBSD/sh sh*-*openbsd*
3105 unset tdesc filename
3107 Use the specified local file as an XML target description, and do
3108 not query the target for its built-in description.
3112 OpenBSD/sh sh*-*-openbsd*
3113 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3114 Toshiba Media Processor mep-elf
3116 * New remote packets
3119 Ignore the specified signals; pass them directly to the debugged program
3120 without stopping other threads or reporting them to GDB.
3122 qXfer:features:read:
3123 Read an XML target description from the target, which describes its
3128 Read or write contents of an spufs file on the target system. These
3129 packets are available only on the Cell/B.E. SPU architecture.
3131 qXfer:libraries:read:
3132 Report the loaded shared libraries. Combined with new "T" packet
3133 response, this packet allows GDB to debug shared libraries on
3134 targets where the operating system manages the list of loaded
3135 libraries (e.g. Windows and SymbianOS).
3139 Support for these obsolete configurations has been removed.
3147 i[34567]86-*-lynxos*
3148 i[34567]86-*-netware*
3149 i[34567]86-*-sco3.2v5*
3150 i[34567]86-*-sco3.2v4*
3152 i[34567]86-*-sysv4.2*
3155 i[34567]86-*-unixware2*
3156 i[34567]86-*-unixware*
3165 * Other removed features
3172 Various m68k-only ROM monitors.
3179 Various Renesas ROM monitors and debugging interfaces for SH and
3184 Support for a Macraigor serial interface to on-chip debugging.
3185 GDB does not directly support the newer parallel or USB
3190 A debug information format. The predecessor to DWARF 2 and
3191 DWARF 3, which are still supported.
3193 Support for the HP aCC compiler on HP-UX/PA-RISC
3195 SOM-encapsulated symbolic debugging information, automatic
3196 invocation of pxdb, and the aCC custom C++ ABI. This does not
3197 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3198 with aCC can still be debugged on an assembly level.
3200 MIPS ".pdr" sections
3202 A MIPS-specific format used to describe stack frame layout
3203 in debugging information.
3207 GDB could work with an older version of Guile to debug
3208 the interpreter and Scheme programs running in it.
3210 set mips stack-arg-size
3211 set mips saved-gpreg-size
3213 Use "set mips abi" to control parameter passing for MIPS.
3215 *** Changes in GDB 6.6
3220 Cell Broadband Engine SPU spu-elf
3222 * GDB can now be configured as a cross-debugger targeting native Windows
3223 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3224 running on a Windows system over TCP/IP to debug Windows programs.
3226 * The GDB remote stub, gdbserver, has been updated to support Windows and
3227 Cygwin debugging. Both single-threaded and multi-threaded programs are
3230 * The "set trust-readonly-sections" command works again. This command was
3231 broken in GDB 6.3, 6.4, and 6.5.
3233 * The "load" command now supports writing to flash memory, if the remote
3234 stub provides the required support.
3236 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3237 longer requires symbolic debug information (e.g. DWARF-2).
3242 unset substitute-path
3243 show substitute-path
3244 Manage a list of substitution rules that GDB uses to rewrite the name
3245 of the directories where the sources are located. This can be useful
3246 for instance when the sources were moved to a different location
3247 between compilation and debugging.
3251 Print each CLI command as it is executed. Each command is prefixed with
3252 a number of `+' symbols representing the nesting depth.
3253 The source command now has a `-v' option to enable the same feature.
3257 The ARM Demon monitor support (RDP protocol, "target rdp").
3259 Kernel Object Display, an embedded debugging feature which only worked with
3260 an obsolete version of Cisco IOS.
3262 The 'set download-write-size' and 'show download-write-size' commands.
3264 * New remote packets
3267 Tell a stub about GDB client features, and request remote target features.
3268 The first feature implemented is PacketSize, which allows the target to
3269 specify the size of packets it can handle - to minimize the number of
3270 packets required and improve performance when connected to a remote
3274 Fetch an OS auxilliary vector from the remote stub. This packet is a
3275 more efficient replacement for qPart:auxv:read.
3277 qXfer:memory-map:read:
3278 Fetch a memory map from the remote stub, including information about
3279 RAM, ROM, and flash memory devices.
3284 Erase and program a flash memory device.
3286 * Removed remote packets
3289 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3290 used it, and only gdbserver implemented it.
3292 *** Changes in GDB 6.5
3296 Renesas M32C/M16C m32c-elf
3298 Morpho Technologies ms1 ms1-elf
3302 init-if-undefined Initialize a convenience variable, but
3303 only if it doesn't already have a value.
3305 The following commands are presently only implemented for native GNU/Linux:
3307 checkpoint Save a snapshot of the program state.
3309 restart <n> Return the program state to a
3310 previously saved state.
3312 info checkpoints List currently saved checkpoints.
3314 delete-checkpoint <n> Delete a previously saved checkpoint.
3316 set|show detach-on-fork Tell gdb whether to detach from a newly
3317 forked process, or to keep debugging it.
3319 info forks List forks of the user program that
3320 are available to be debugged.
3322 fork <n> Switch to debugging one of several
3323 forks of the user program that are
3324 available to be debugged.
3326 delete-fork <n> Delete a fork from the list of forks
3327 that are available to be debugged (and
3328 kill the forked process).
3330 detach-fork <n> Delete a fork from the list of forks
3331 that are available to be debugged (and
3332 allow the process to continue).
3336 Morpho Technologies ms2 ms1-elf
3338 * Improved Windows host support
3340 GDB now builds as a cross debugger hosted on i686-mingw32, including
3341 native console support, and remote communications using either
3342 network sockets or serial ports.
3344 * Improved Modula-2 language support
3346 GDB can now print most types in the Modula-2 syntax. This includes:
3347 basic types, set types, record types, enumerated types, range types,
3348 pointer types and ARRAY types. Procedure var parameters are correctly
3349 printed and hexadecimal addresses and character constants are also
3350 written in the Modula-2 syntax. Best results can be obtained by using
3351 GNU Modula-2 together with the -gdwarf-2 command line option.
3355 The ARM rdi-share module.
3357 The Netware NLM debug server.
3359 *** Changes in GDB 6.4
3361 * New native configurations
3363 OpenBSD/arm arm*-*-openbsd*
3364 OpenBSD/mips64 mips64-*-openbsd*
3368 Morpho Technologies ms1 ms1-elf
3370 * New command line options
3372 --batch-silent As for --batch, but totally silent.
3373 --return-child-result The debugger will exist with the same value
3374 the child (debugged) program exited with.
3375 --eval-command COMMAND, -ex COMMAND
3376 Execute a single GDB CLI command. This may be
3377 specified multiple times and in conjunction
3378 with the --command (-x) option.
3380 * Deprecated commands removed
3382 The following commands, that were deprecated in 2000, have been
3386 set|show arm disassembly-flavor set|show arm disassembler
3387 othernames set arm disassembler
3388 set|show remotedebug set|show debug remote
3389 set|show archdebug set|show debug arch
3390 set|show eventdebug set|show debug event
3393 * New BSD user-level threads support
3395 It is now possible to debug programs using the user-level threads
3396 library on OpenBSD and FreeBSD. Currently supported (target)
3399 FreeBSD/amd64 x86_64-*-freebsd*
3400 FreeBSD/i386 i386-*-freebsd*
3401 OpenBSD/i386 i386-*-openbsd*
3403 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3404 are not yet supported.
3406 * New support for Matsushita MN10300 w/sim added
3407 (Work in progress). mn10300-elf.
3409 * REMOVED configurations and files
3411 VxWorks and the XDR protocol *-*-vxworks
3412 Motorola MCORE mcore-*-*
3413 National Semiconductor NS32000 ns32k-*-*
3415 * New "set print array-indexes" command
3417 After turning this setting "on", GDB prints the index of each element
3418 when displaying arrays. The default is "off" to preserve the previous
3421 * VAX floating point support
3423 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3425 * User-defined command support
3427 In addition to using $arg0..$arg9 for argument passing, it is now possible
3428 to use $argc to determine now many arguments have been passed. See the
3429 section on user-defined commands in the user manual for more information.
3431 *** Changes in GDB 6.3:
3433 * New command line option
3435 GDB now accepts -l followed by a number to set the timeout for remote
3438 * GDB works with GCC -feliminate-dwarf2-dups
3440 GDB now supports a more compact representation of DWARF-2 debug
3441 information using DW_FORM_ref_addr references. These are produced
3442 by GCC with the option -feliminate-dwarf2-dups and also by some
3443 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3444 to use -feliminate-dwarf2-dups.
3446 * Internationalization
3448 When supported by the host system, GDB will be built with
3449 internationalization (libintl). The task of marking up the sources is
3450 continued, we're looking forward to our first translation.
3454 Initial support for debugging programs compiled with the GNAT
3455 implementation of the Ada programming language has been integrated
3456 into GDB. In this release, support is limited to expression evaluation.
3458 * New native configurations
3460 GNU/Linux/m32r m32r-*-linux-gnu
3464 GDB's remote protocol now includes support for the 'p' packet. This
3465 packet is used to fetch individual registers from a remote inferior.
3467 * END-OF-LIFE registers[] compatibility module
3469 GDB's internal register infrastructure has been completely rewritten.
3470 The new infrastructure making possible the implementation of key new
3471 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3474 GDB 6.3 will be the last release to include the the registers[]
3475 compatibility module that allowed out-of-date configurations to
3476 continue to work. This change directly impacts the following
3486 powerpc bdm protocol
3488 Unless there is activity to revive these configurations, they will be
3489 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3491 * OBSOLETE configurations and files
3493 Configurations that have been declared obsolete in this release have
3494 been commented out. Unless there is activity to revive these
3495 configurations, the next release of GDB will have their sources
3496 permanently REMOVED.
3505 *** Changes in GDB 6.2.1:
3507 * MIPS `break main; run' gave an heuristic-fence-post warning
3509 When attempting to run even a simple program, a warning about
3510 heuristic-fence-post being hit would be reported. This problem has
3513 * MIPS IRIX 'long double' crashed GDB
3515 When examining a long double variable, GDB would get a segmentation
3516 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3517 IRIX long double values).
3521 A bug in the VAX stack code was causing problems with the "next"
3522 command. This problem has been fixed.
3524 *** Changes in GDB 6.2:
3526 * Fix for ``many threads''
3528 On GNU/Linux systems that use the NPTL threads library, a program
3529 rapidly creating and deleting threads would confuse GDB leading to the
3532 ptrace: No such process.
3533 thread_db_get_info: cannot get thread info: generic error
3535 This problem has been fixed.
3537 * "-async" and "-noasync" options removed.
3539 Support for the broken "-noasync" option has been removed (it caused
3542 * New ``start'' command.
3544 This command runs the program until the begining of the main procedure.
3546 * New BSD Kernel Data Access Library (libkvm) interface
3548 Using ``target kvm'' it is now possible to debug kernel core dumps and
3549 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3550 platforms. Currently supported (native-only) configurations are:
3552 FreeBSD/amd64 x86_64-*-freebsd*
3553 FreeBSD/i386 i?86-*-freebsd*
3554 NetBSD/i386 i?86-*-netbsd*
3555 NetBSD/m68k m68*-*-netbsd*
3556 NetBSD/sparc sparc-*-netbsd*
3557 OpenBSD/amd64 x86_64-*-openbsd*
3558 OpenBSD/i386 i?86-*-openbsd*
3559 OpenBSD/m68k m68*-openbsd*
3560 OpenBSD/sparc sparc-*-openbsd*
3562 * Signal trampoline code overhauled
3564 Many generic problems with GDB's signal handling code have been fixed.
3565 These include: backtraces through non-contiguous stacks; recognition
3566 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3567 call; backtrace through a signal trampoline; step into and out of
3568 signal handlers; and single-stepping in the signal trampoline.
3570 Please note that kernel bugs are a limiting factor here. These
3571 features have been shown to work on an s390 GNU/Linux system that
3572 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3574 * Cygwin support for DWARF 2 added.
3576 * New native configurations
3578 GNU/Linux/hppa hppa*-*-linux*
3579 OpenBSD/hppa hppa*-*-openbsd*
3580 OpenBSD/m68k m68*-*-openbsd*
3581 OpenBSD/m88k m88*-*-openbsd*
3582 OpenBSD/powerpc powerpc-*-openbsd*
3583 NetBSD/vax vax-*-netbsd*
3584 OpenBSD/vax vax-*-openbsd*
3586 * END-OF-LIFE frame compatibility module
3588 GDB's internal frame infrastructure has been completely rewritten.
3589 The new infrastructure making it possible to support key new features
3590 including DWARF 2 Call Frame Information. To aid in the task of
3591 migrating old configurations to this new infrastructure, a
3592 compatibility module, that allowed old configurations to continue to
3593 work, was also included.
3595 GDB 6.2 will be the last release to include this frame compatibility
3596 module. This change directly impacts the following configurations:
3606 Unless there is activity to revive these configurations, they will be
3607 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3609 * REMOVED configurations and files
3611 Sun 3, running SunOS 3 m68*-*-sunos3*
3612 Sun 3, running SunOS 4 m68*-*-sunos4*
3613 Sun 2, running SunOS 3 m68000-*-sunos3*
3614 Sun 2, running SunOS 4 m68000-*-sunos4*
3615 Motorola 680x0 running LynxOS m68*-*-lynxos*
3616 AT&T 3b1/Unix pc m68*-att-*
3617 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3618 decstation mips-dec-* mips-little-*
3619 riscos mips-*-riscos* mips-*-sysv*
3620 sonymips mips-sony-*
3621 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3623 *** Changes in GDB 6.1.1:
3625 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3627 The TUI (Text-mode User Interface) is now built as part of a default
3628 GDB configuration. It is enabled by either selecting the TUI with the
3629 command line option "-i=tui" or by running the separate "gdbtui"
3630 program. For more information on the TUI, see the manual "Debugging
3633 * Pending breakpoint support (also included in GDB 6.1)
3635 Support has been added to allow you to specify breakpoints in shared
3636 libraries that have not yet been loaded. If a breakpoint location
3637 cannot be found, and the "breakpoint pending" option is set to auto,
3638 GDB queries you if you wish to make the breakpoint pending on a future
3639 shared-library load. If and when GDB resolves the breakpoint symbol,
3640 the pending breakpoint is removed as one or more regular breakpoints
3643 Pending breakpoints are very useful for GCJ Java debugging.
3645 * Fixed ISO-C build problems
3647 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3648 non ISO-C code that stopped them being built using a more strict ISO-C
3649 compiler (e.g., IBM's C compiler).
3651 * Fixed build problem on IRIX 5
3653 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3654 wasn't able to compile compile on an IRIX 5 system.
3656 * Added execute permission to gdb/gdbserver/configure
3658 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3659 permission. This bug would cause configure to fail on a number of
3660 systems (Solaris, IRIX). Ref: server/519.
3662 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3664 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3665 has been updated to use constant array sizes.
3667 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3669 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3670 its generated DWARF Call Frame Info. This encoding was causing GDB to
3671 panic, that panic has been fixed. Ref: gdb/1628.
3673 * Fixed a problem when examining parameters in shared library code.
3675 When examining parameters in optimized shared library code generated
3676 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3677 not available''. GDB now correctly displays the variable's value.
3679 *** Changes in GDB 6.1:
3681 * Removed --with-mmalloc
3683 Support for the mmalloc memory manager has been removed, as it
3684 conflicted with the internal gdb byte cache.
3686 * Changes in AMD64 configurations
3688 The AMD64 target now includes the %cs and %ss registers. As a result
3689 the AMD64 remote protocol has changed; this affects the floating-point
3690 and SSE registers. If you rely on those registers for your debugging,
3691 you should upgrade gdbserver on the remote side.
3693 * Revised SPARC target
3695 The SPARC target has been completely revised, incorporating the
3696 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3697 support for LynxOS and SunOS 4 has been dropped. Calling functions
3698 from within GDB on operating systems with a non-executable stack
3699 (Solaris, OpenBSD) now works.
3703 GDB has a new C++ demangler which does a better job on the mangled
3704 names generated by current versions of g++. It also runs faster, so
3705 with this and other changes gdb should now start faster on large C++
3708 * DWARF 2 Location Expressions
3710 GDB support for location expressions has been extended to support function
3711 arguments and frame bases. Older versions of GDB could crash when they
3714 * C++ nested types and namespaces
3716 GDB's support for nested types and namespaces in C++ has been
3717 improved, especially if you use the DWARF 2 debugging format. (This
3718 is the default for recent versions of GCC on most platforms.)
3719 Specifically, if you have a class "Inner" defined within a class or
3720 namespace "Outer", then GDB realizes that the class's name is
3721 "Outer::Inner", not simply "Inner". This should greatly reduce the
3722 frequency of complaints about not finding RTTI symbols. In addition,
3723 if you are stopped at inside of a function defined within a namespace,
3724 GDB modifies its name lookup accordingly.
3726 * New native configurations
3728 NetBSD/amd64 x86_64-*-netbsd*
3729 OpenBSD/amd64 x86_64-*-openbsd*
3730 OpenBSD/alpha alpha*-*-openbsd*
3731 OpenBSD/sparc sparc-*-openbsd*
3732 OpenBSD/sparc64 sparc64-*-openbsd*
3734 * New debugging protocols
3736 M32R with SDI protocol m32r-*-elf*
3738 * "set prompt-escape-char" command deleted.
3740 The command "set prompt-escape-char" has been deleted. This command,
3741 and its very obscure effet on GDB's prompt, was never documented,
3742 tested, nor mentioned in the NEWS file.
3744 * OBSOLETE configurations and files
3746 Configurations that have been declared obsolete in this release have
3747 been commented out. Unless there is activity to revive these
3748 configurations, the next release of GDB will have their sources
3749 permanently REMOVED.
3751 Sun 3, running SunOS 3 m68*-*-sunos3*
3752 Sun 3, running SunOS 4 m68*-*-sunos4*
3753 Sun 2, running SunOS 3 m68000-*-sunos3*
3754 Sun 2, running SunOS 4 m68000-*-sunos4*
3755 Motorola 680x0 running LynxOS m68*-*-lynxos*
3756 AT&T 3b1/Unix pc m68*-att-*
3757 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3758 decstation mips-dec-* mips-little-*
3759 riscos mips-*-riscos* mips-*-sysv*
3760 sonymips mips-sony-*
3761 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3763 * REMOVED configurations and files
3765 SGI Irix-4.x mips-sgi-irix4 or iris4
3766 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3767 Z8000 simulator z8k-zilog-none or z8ksim
3768 Matsushita MN10200 w/simulator mn10200-*-*
3769 H8/500 simulator h8500-hitachi-hms or h8500hms
3770 HP/PA running BSD hppa*-*-bsd*
3771 HP/PA running OSF/1 hppa*-*-osf*
3772 HP/PA Pro target hppa*-*-pro*
3773 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3774 386BSD i[3456]86-*-bsd*
3775 Sequent family i[3456]86-sequent-sysv4*
3776 i[3456]86-sequent-sysv*
3777 i[3456]86-sequent-bsd*
3778 SPARC running LynxOS sparc-*-lynxos*
3779 SPARC running SunOS 4 sparc-*-sunos4*
3780 Tsqware Sparclet sparclet-*-*
3781 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3783 *** Changes in GDB 6.0:
3787 Support for debugging the Objective-C programming language has been
3788 integrated into GDB.
3790 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3792 DWARF 2's Call Frame Information makes available compiler generated
3793 information that more exactly describes the program's run-time stack.
3794 By using this information, GDB is able to provide more robust stack
3797 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3798 have been updated to use a new backtrace mechanism which includes
3799 DWARF 2 CFI support.
3803 GDB's remote protocol has been extended to include support for hosted
3804 file I/O (where the remote target uses GDB's file system). See GDB's
3805 remote protocol documentation for details.
3807 * All targets using the new architecture framework.
3809 All of GDB's targets have been updated to use the new internal
3810 architecture framework. The way is now open for future GDB releases
3811 to include cross-architecture native debugging support (i386 on amd64,
3814 * GNU/Linux's Thread Local Storage (TLS)
3816 GDB now includes support for for the GNU/Linux implementation of
3817 per-thread variables.
3819 * GNU/Linux's Native POSIX Thread Library (NPTL)
3821 GDB's thread code has been updated to work with either the new
3822 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3824 * Separate debug info.
3826 GDB, in conjunction with BINUTILS, now supports a mechanism for
3827 automatically loading debug information from a separate file. Instead
3828 of shipping full debug and non-debug versions of system libraries,
3829 system integrators can now instead ship just the stripped libraries
3830 and optional debug files.
3832 * DWARF 2 Location Expressions
3834 DWARF 2 Location Expressions allow the compiler to more completely
3835 describe the location of variables (even in optimized code) to the
3838 GDB now includes preliminary support for location expressions (support
3839 for DW_OP_piece is still missing).
3843 A number of long standing bugs that caused GDB to die while starting a
3844 Java application have been fixed. GDB's Java support is now
3845 considered "useable".
3847 * GNU/Linux support for fork, vfork, and exec.
3849 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3850 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3853 * GDB supports logging output to a file
3855 There are two new commands, "set logging" and "show logging", which can be
3856 used to capture GDB's output to a file.
3858 * The meaning of "detach" has changed for gdbserver
3860 The "detach" command will now resume the application, as documented. To
3861 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3864 * d10v, m68hc11 `regs' command deprecated
3866 The `info registers' command has been updated so that it displays the
3867 registers using a format identical to the old `regs' command.
3871 A new command, "maint set profile on/off", has been added. This command can
3872 be used to enable or disable profiling while running GDB, to profile a
3873 session or a set of commands. In addition there is a new configure switch,
3874 "--enable-profiling", which will cause GDB to be compiled with profiling
3875 data, for more informative profiling results.
3877 * Default MI syntax changed to "mi2".
3879 The default MI (machine interface) syntax, enabled by the command line
3880 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3881 "mi1", can be enabled by specifying the option "-i=mi1".
3883 Support for the original "mi0" syntax (included in GDB 5.0) has been
3886 Fix for gdb/192: removed extraneous space when displaying frame level.
3887 Fix for gdb/672: update changelist is now output in mi list format.
3888 Fix for gdb/702: a -var-assign that updates the value now shows up
3889 in a subsequent -var-update.
3891 * New native configurations.
3893 FreeBSD/amd64 x86_64-*-freebsd*
3895 * Multi-arched targets.
3897 HP/PA HPUX11 hppa*-*-hpux*
3898 Renesas M32R/D w/simulator m32r-*-elf*
3900 * OBSOLETE configurations and files
3902 Configurations that have been declared obsolete in this release have
3903 been commented out. Unless there is activity to revive these
3904 configurations, the next release of GDB will have their sources
3905 permanently REMOVED.
3907 Z8000 simulator z8k-zilog-none or z8ksim
3908 Matsushita MN10200 w/simulator mn10200-*-*
3909 H8/500 simulator h8500-hitachi-hms or h8500hms
3910 HP/PA running BSD hppa*-*-bsd*
3911 HP/PA running OSF/1 hppa*-*-osf*
3912 HP/PA Pro target hppa*-*-pro*
3913 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3914 Sequent family i[3456]86-sequent-sysv4*
3915 i[3456]86-sequent-sysv*
3916 i[3456]86-sequent-bsd*
3917 Tsqware Sparclet sparclet-*-*
3918 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3920 * REMOVED configurations and files
3923 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3924 IBM AIX PS/2 i[3456]86-*-aix
3925 i386 running Mach 3.0 i[3456]86-*-mach3*
3926 i386 running Mach i[3456]86-*-mach*
3927 i386 running OSF/1 i[3456]86-*osf1mk*
3928 HP/Apollo 68k Family m68*-apollo*-sysv*,
3930 m68*-hp-bsd*, m68*-hp-hpux*
3931 Argonaut Risc Chip (ARC) arc-*-*
3932 Mitsubishi D30V d30v-*-*
3933 Fujitsu FR30 fr30-*-elf*
3934 OS/9000 i[34]86-*-os9k
3935 I960 with MON960 i960-*-coff
3937 * MIPS $fp behavior changed
3939 The convenience variable $fp, for the MIPS, now consistently returns
3940 the address of the current frame's base. Previously, depending on the
3941 context, $fp could refer to either $sp or the current frame's base
3942 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3943 The GNU Source-Level Debugger''.
3945 *** Changes in GDB 5.3:
3947 * GNU/Linux shared library multi-threaded performance improved.
3949 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3950 `/proc', in preference to `ptrace' for memory reads. This may result
3951 in an improvement in the start-up time of multi-threaded, shared
3952 library applications when run under GDB. One GDB user writes: ``loads
3953 shared libs like mad''.
3955 * ``gdbserver'' now supports multi-threaded applications on some targets
3957 Support for debugging multi-threaded applications which use
3958 the GNU/Linux LinuxThreads package has been added for
3959 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3960 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3962 * GDB now supports C/C++ preprocessor macros.
3964 GDB now expands preprocessor macro invocations in C/C++ expressions,
3965 and provides various commands for showing macro definitions and how
3968 The new command `macro expand EXPRESSION' expands any macro
3969 invocations in expression, and shows the result.
3971 The new command `show macro MACRO-NAME' shows the definition of the
3972 macro named MACRO-NAME, and where it was defined.
3974 Most compilers don't include information about macros in the debugging
3975 information by default. In GCC 3.1, for example, you need to compile
3976 your program with the options `-gdwarf-2 -g3'. If the macro
3977 information is present in the executable, GDB will read it.
3979 * Multi-arched targets.
3981 DEC Alpha (partial) alpha*-*-*
3982 DEC VAX (partial) vax-*-*
3984 National Semiconductor NS32000 (partial) ns32k-*-*
3985 Motorola 68000 (partial) m68k-*-*
3986 Motorola MCORE mcore-*-*
3990 Fujitsu FRV architecture added by Red Hat frv*-*-*
3993 * New native configurations
3995 Alpha NetBSD alpha*-*-netbsd*
3996 SH NetBSD sh*-*-netbsdelf*
3997 MIPS NetBSD mips*-*-netbsd*
3998 UltraSPARC NetBSD sparc64-*-netbsd*
4000 * OBSOLETE configurations and files
4002 Configurations that have been declared obsolete in this release have
4003 been commented out. Unless there is activity to revive these
4004 configurations, the next release of GDB will have their sources
4005 permanently REMOVED.
4007 Mitsubishi D30V d30v-*-*
4008 OS/9000 i[34]86-*-os9k
4009 IBM AIX PS/2 i[3456]86-*-aix
4010 Fujitsu FR30 fr30-*-elf*
4011 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4012 Argonaut Risc Chip (ARC) arc-*-*
4013 i386 running Mach 3.0 i[3456]86-*-mach3*
4014 i386 running Mach i[3456]86-*-mach*
4015 i386 running OSF/1 i[3456]86-*osf1mk*
4016 HP/Apollo 68k Family m68*-apollo*-sysv*,
4018 m68*-hp-bsd*, m68*-hp-hpux*
4019 I960 with MON960 i960-*-coff
4021 * OBSOLETE languages
4023 CHILL, a Pascal like language used by telecommunications companies.
4025 * REMOVED configurations and files
4027 AMD 29k family via UDI a29k-amd-udi, udi29k
4028 A29K VxWorks a29k-*-vxworks
4029 AMD 29000 embedded, using EBMON a29k-none-none
4030 AMD 29000 embedded with COFF a29k-none-coff
4031 AMD 29000 embedded with a.out a29k-none-aout
4033 testsuite/gdb.hp/gdb.threads-hp/ directory
4035 * New command "set max-user-call-depth <nnn>"
4037 This command allows the user to limit the call depth of user-defined
4038 commands. The default is 1024.
4040 * Changes in FreeBSD/i386 native debugging.
4042 Support for the "generate-core-file" has been added.
4044 * New commands "dump", "append", and "restore".
4046 These commands allow data to be copied from target memory
4047 to a bfd-format or binary file (dump and append), and back
4048 from a file into memory (restore).
4050 * Improved "next/step" support on multi-processor Alpha Tru64.
4052 The previous single-step mechanism could cause unpredictable problems,
4053 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4054 of a software single-step mechanism prevents this.
4056 *** Changes in GDB 5.2.1:
4064 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4065 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4066 Fix, by Joel Brobecker imported from mainline.
4068 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4069 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4070 Fix, by Fred Fish, imported from mainline.
4072 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4073 Surprisingly enough, it works now.
4074 By Michal Ludvig, imported from mainline.
4076 i386 hardware watchpoint support:
4077 avoid misses on second run for some targets.
4078 By Pierre Muller, imported from mainline.
4080 *** Changes in GDB 5.2:
4082 * New command "set trust-readonly-sections on[off]".
4084 This command is a hint that tells gdb that read-only sections
4085 really are read-only (ie. that their contents will not change).
4086 In this mode, gdb will go to the object file rather than the
4087 target to read memory from read-only sections (such as ".text").
4088 This can be a significant performance improvement on some
4089 (notably embedded) targets.
4091 * New command "generate-core-file" (or "gcore").
4093 This new gdb command allows the user to drop a core file of the child
4094 process state at any time. So far it's been implemented only for
4095 GNU/Linux and Solaris, but should be relatively easily ported to other
4096 hosts. Argument is core file name (defaults to core.<pid>).
4098 * New command line option
4100 GDB now accepts --pid or -p followed by a process id.
4102 * Change in command line behavior -- corefiles vs. process ids.
4104 There is a subtle behavior in the way in which GDB handles
4105 command line arguments. The first non-flag argument is always
4106 a program to debug, but the second non-flag argument may either
4107 be a corefile or a process id. Previously, GDB would attempt to
4108 open the second argument as a corefile, and if that failed, would
4109 issue a superfluous error message and then attempt to attach it as
4110 a process. Now, if the second argument begins with a non-digit,
4111 it will be treated as a corefile. If it begins with a digit,
4112 GDB will attempt to attach it as a process, and if no such process
4113 is found, will then attempt to open it as a corefile.
4115 * Changes in ARM configurations.
4117 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4118 configuration is fully multi-arch.
4120 * New native configurations
4122 ARM NetBSD arm*-*-netbsd*
4123 x86 OpenBSD i[3456]86-*-openbsd*
4124 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4125 Sparc64 running FreeBSD sparc64-*-freebsd*
4129 Sanyo XStormy16 xstormy16-elf
4131 * OBSOLETE configurations and files
4133 Configurations that have been declared obsolete in this release have
4134 been commented out. Unless there is activity to revive these
4135 configurations, the next release of GDB will have their sources
4136 permanently REMOVED.
4138 AMD 29k family via UDI a29k-amd-udi, udi29k
4139 A29K VxWorks a29k-*-vxworks
4140 AMD 29000 embedded, using EBMON a29k-none-none
4141 AMD 29000 embedded with COFF a29k-none-coff
4142 AMD 29000 embedded with a.out a29k-none-aout
4144 testsuite/gdb.hp/gdb.threads-hp/ directory
4146 * REMOVED configurations and files
4148 TI TMS320C80 tic80-*-*
4150 PowerPC Solaris powerpcle-*-solaris*
4151 PowerPC Windows NT powerpcle-*-cygwin32
4152 PowerPC Netware powerpc-*-netware*
4153 Harris/CXUX m88k m88*-harris-cxux*
4154 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4155 ns32k-utek-sysv* ns32k-utek-*
4156 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4157 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4158 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4159 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4160 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4162 * Changes to command line processing
4164 The new `--args' feature can be used to specify command-line arguments
4165 for the inferior from gdb's command line.
4167 * Changes to key bindings
4169 There is a new `operate-and-get-next' function bound to `C-o'.
4171 *** Changes in GDB 5.1.1
4173 Fix compile problem on DJGPP.
4175 Fix a problem with floating-point registers on the i386 being
4178 Fix to stop GDB crashing on .debug_str debug info.
4180 Numerous documentation fixes.
4182 Numerous testsuite fixes.
4184 *** Changes in GDB 5.1:
4186 * New native configurations
4188 Alpha FreeBSD alpha*-*-freebsd*
4189 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4190 MIPS GNU/Linux mips*-*-linux*
4191 MIPS SGI Irix 6.x mips*-sgi-irix6*
4192 ia64 AIX ia64-*-aix*
4193 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4197 Motorola 68HC11 and 68HC12 m68hc11-elf
4199 UltraSparc running GNU/Linux sparc64-*-linux*
4201 * OBSOLETE configurations and files
4203 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4204 Harris/CXUX m88k m88*-harris-cxux*
4205 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4206 ns32k-utek-sysv* ns32k-utek-*
4207 TI TMS320C80 tic80-*-*
4209 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4210 PowerPC Solaris powerpcle-*-solaris*
4211 PowerPC Windows NT powerpcle-*-cygwin32
4212 PowerPC Netware powerpc-*-netware*
4213 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4214 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4215 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4216 Apple Macintosh (MPW) host N/A
4218 stuff.c (Program to stuff files into a specially prepared space in kdb)
4219 kdb-start.c (Main loop for the standalone kernel debugger)
4221 Configurations that have been declared obsolete in this release have
4222 been commented out. Unless there is activity to revive these
4223 configurations, the next release of GDB will have their sources
4224 permanently REMOVED.
4226 * REMOVED configurations and files
4228 Altos 3068 m68*-altos-*
4229 Convex c1-*-*, c2-*-*
4231 ARM RISCix arm-*-* (as host)
4235 * GDB has been converted to ISO C.
4237 GDB's source code has been converted to ISO C. In particular, the
4238 sources are fully protoized, and rely on standard headers being
4243 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4245 * The MI enabled by default.
4247 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4248 revised and enabled by default. Packages which use GDB as a debugging
4249 engine behind a UI or another front end are encouraged to switch to
4250 using the GDB/MI interface, instead of the old annotations interface
4251 which is now deprecated.
4253 * Support for debugging Pascal programs.
4255 GDB now includes support for debugging Pascal programs. The following
4256 main features are supported:
4258 - Pascal-specific data types such as sets;
4260 - automatic recognition of Pascal sources based on file-name
4263 - Pascal-style display of data types, variables, and functions;
4265 - a Pascal expression parser.
4267 However, some important features are not yet supported.
4269 - Pascal string operations are not supported at all;
4271 - there are some problems with boolean types;
4273 - Pascal type hexadecimal constants are not supported
4274 because they conflict with the internal variables format;
4276 - support for Pascal objects and classes is not full yet;
4278 - unlike Pascal, GDB is case-sensitive for symbol names.
4280 * Changes in completion.
4282 Commands such as `shell', `run' and `set args', which pass arguments
4283 to inferior programs, now complete on file names, similar to what
4284 users expect at the shell prompt.
4286 Commands which accept locations, such as `disassemble', `print',
4287 `breakpoint', `until', etc. now complete on filenames as well as
4288 program symbols. Thus, if you type "break foob TAB", and the source
4289 files linked into the programs include `foobar.c', that file name will
4290 be one of the candidates for completion. However, file names are not
4291 considered for completion after you typed a colon that delimits a file
4292 name from a name of a function in that file, as in "break foo.c:bar".
4294 `set demangle-style' completes on available demangling styles.
4296 * New platform-independent commands:
4298 It is now possible to define a post-hook for a command as well as a
4299 hook that runs before the command. For more details, see the
4300 documentation of `hookpost' in the GDB manual.
4302 * Changes in GNU/Linux native debugging.
4304 Support for debugging multi-threaded programs has been completely
4305 revised for all platforms except m68k and sparc. You can now debug as
4306 many threads as your system allows you to have.
4308 Attach/detach is supported for multi-threaded programs.
4310 Support for SSE registers was added for x86. This doesn't work for
4311 multi-threaded programs though.
4313 * Changes in MIPS configurations.
4315 Multi-arch support is enabled for all MIPS configurations.
4317 GDB can now be built as native debugger on SGI Irix 6.x systems for
4318 debugging n32 executables. (Debugging 64-bit executables is not yet
4321 * Unified support for hardware watchpoints in all x86 configurations.
4323 Most (if not all) native x86 configurations support hardware-assisted
4324 breakpoints and watchpoints in a unified manner. This support
4325 implements debug register sharing between watchpoints, which allows to
4326 put a virtually infinite number of watchpoints on the same address,
4327 and also supports watching regions up to 16 bytes with several debug
4330 The new maintenance command `maintenance show-debug-regs' toggles
4331 debugging print-outs in functions that insert, remove, and test
4332 watchpoints and hardware breakpoints.
4334 * Changes in the DJGPP native configuration.
4336 New command ``info dos sysinfo'' displays assorted information about
4337 the CPU, OS, memory, and DPMI server.
4339 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4340 display information about segment descriptors stored in GDT, LDT, and
4343 New commands ``info dos pde'' and ``info dos pte'' display entries
4344 from Page Directory and Page Tables (for now works with CWSDPMI only).
4345 New command ``info dos address-pte'' displays the Page Table entry for
4346 a given linear address.
4348 GDB can now pass command lines longer than 126 characters to the
4349 program being debugged (requires an update to the libdbg.a library
4350 which is part of the DJGPP development kit).
4352 DWARF2 debug info is now supported.
4354 It is now possible to `step' and `next' through calls to `longjmp'.
4356 * Changes in documentation.
4358 All GDB documentation was converted to GFDL, the GNU Free
4359 Documentation License.
4361 Tracepoints-related commands are now fully documented in the GDB
4364 TUI, the Text-mode User Interface, is now documented in the manual.
4366 Tracepoints-related commands are now fully documented in the GDB
4369 The "GDB Internals" manual now has an index. It also includes
4370 documentation of `ui_out' functions, GDB coding standards, x86
4371 hardware watchpoints, and memory region attributes.
4373 * GDB's version number moved to ``version.in''
4375 The Makefile variable VERSION has been replaced by the file
4376 ``version.in''. People creating GDB distributions should update the
4377 contents of this file.
4381 GUD support is now a standard part of the EMACS distribution.
4383 *** Changes in GDB 5.0:
4385 * Improved support for debugging FP programs on x86 targets
4387 Unified and much-improved support for debugging floating-point
4388 programs on all x86 targets. In particular, ``info float'' now
4389 displays the FP registers in the same format on all x86 targets, with
4390 greater level of detail.
4392 * Improvements and bugfixes in hardware-assisted watchpoints
4394 It is now possible to watch array elements, struct members, and
4395 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4396 on x86 targets no longer erroneously trigger when the address is
4399 * Improvements in the native DJGPP version of GDB
4401 The distribution now includes all the scripts and auxiliary files
4402 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4403 machines ``out of the box''.
4405 The DJGPP version can now debug programs that use signals. It is
4406 possible to catch signals that happened in the debuggee, deliver
4407 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4408 would kill the program being debugged.) Programs that hook hardware
4409 interrupts (keyboard, timer, etc.) can also be debugged.
4411 It is now possible to debug DJGPP programs that redirect their
4412 standard handles or switch them to raw (as opposed to cooked) mode, or
4413 even close them. The command ``run < foo > bar'' works as expected,
4414 and ``info terminal'' reports useful information about the debuggee's
4415 terminal, including raw/cooked mode, redirection, etc.
4417 The DJGPP version now uses termios functions for console I/O, which
4418 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4421 DOS-style file names with drive letters are now fully supported by
4424 It is now possible to debug DJGPP programs that switch their working
4425 directory. It is also possible to rerun the debuggee any number of
4426 times without restarting GDB; thus, you can use the same setup,
4427 breakpoints, etc. for many debugging sessions.
4429 * New native configurations
4431 ARM GNU/Linux arm*-*-linux*
4432 PowerPC GNU/Linux powerpc-*-linux*
4436 Motorola MCore mcore-*-*
4437 x86 VxWorks i[3456]86-*-vxworks*
4438 PowerPC VxWorks powerpc-*-vxworks*
4439 TI TMS320C80 tic80-*-*
4441 * OBSOLETE configurations
4443 Altos 3068 m68*-altos-*
4444 Convex c1-*-*, c2-*-*
4446 ARM RISCix arm-*-* (as host)
4449 Configurations that have been declared obsolete will be commented out,
4450 but the code will be left in place. If there is no activity to revive
4451 these configurations before the next release of GDB, the sources will
4452 be permanently REMOVED.
4454 * Gould support removed
4456 Support for the Gould PowerNode and NP1 has been removed.
4458 * New features for SVR4
4460 On SVR4 native platforms (such as Solaris), if you attach to a process
4461 without first loading a symbol file, GDB will now attempt to locate and
4462 load symbols from the running process's executable file.
4464 * Many C++ enhancements
4466 C++ support has been greatly improved. Overload resolution now works properly
4467 in almost all cases. RTTI support is on the way.
4469 * Remote targets can connect to a sub-program
4471 A popen(3) style serial-device has been added. This device starts a
4472 sub-process (such as a stand-alone simulator) and then communicates
4473 with that. The sub-program to run is specified using the syntax
4474 ``|<program> <args>'' vis:
4476 (gdb) set remotedebug 1
4477 (gdb) target extended-remote |mn10300-elf-sim program-args
4479 * MIPS 64 remote protocol
4481 A long standing bug in the mips64 remote protocol where by GDB
4482 expected certain 32 bit registers (ex SR) to be transfered as 32
4483 instead of 64 bits has been fixed.
4485 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4486 added to provide backward compatibility with older versions of GDB.
4488 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4490 The command ``set remotebinarydownload'' command has been replaced by
4491 ``set remote X-packet''. Other commands in ``set remote'' family
4492 include ``set remote P-packet''.
4494 * Breakpoint commands accept ranges.
4496 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4497 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4498 ``tracepoint passcount'' also accepts a range of tracepoints.
4500 * ``apropos'' command added.
4502 The ``apropos'' command searches through command names and
4503 documentation strings, printing out matches, making it much easier to
4504 try to find a command that does what you are looking for.
4508 A new machine oriented interface (MI) has been added to GDB. This
4509 interface is designed for debug environments running GDB as a separate
4510 process. This is part of the long term libGDB project. See the
4511 "GDB/MI" chapter of the GDB manual for further information. It can be
4512 enabled by configuring with:
4514 .../configure --enable-gdbmi
4516 *** Changes in GDB-4.18:
4518 * New native configurations
4520 HP-UX 10.20 hppa*-*-hpux10.20
4521 HP-UX 11.x hppa*-*-hpux11.0*
4522 M68K GNU/Linux m68*-*-linux*
4526 Fujitsu FR30 fr30-*-elf*
4527 Intel StrongARM strongarm-*-*
4528 Mitsubishi D30V d30v-*-*
4530 * OBSOLETE configurations
4532 Gould PowerNode, NP1 np1-*-*, pn-*-*
4534 Configurations that have been declared obsolete will be commented out,
4535 but the code will be left in place. If there is no activity to revive
4536 these configurations before the next release of GDB, the sources will
4537 be permanently REMOVED.
4541 As a compatibility experiment, GDB's source files buildsym.h and
4542 buildsym.c have been converted to pure standard C, no longer
4543 containing any K&R compatibility code. We believe that all systems in
4544 use today either come with a standard C compiler, or have a GCC port
4545 available. If this is not true, please report the affected
4546 configuration to bug-gdb@gnu.org immediately. See the README file for
4547 information about getting a standard C compiler if you don't have one
4552 GDB now uses readline 2.2.
4554 * set extension-language
4556 You can now control the mapping between filename extensions and source
4557 languages by using the `set extension-language' command. For instance,
4558 you can ask GDB to treat .c files as C++ by saying
4559 set extension-language .c c++
4560 The command `info extensions' lists all of the recognized extensions
4561 and their associated languages.
4563 * Setting processor type for PowerPC and RS/6000
4565 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4566 you can use the `set processor' command to specify what variant of the
4567 PowerPC family you are debugging. The command
4571 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4572 following PowerPC and RS6000 variants:
4574 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4575 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4577 403GC IBM PowerPC 403GC
4578 505 Motorola PowerPC 505
4579 860 Motorola PowerPC 860 or 850
4580 601 Motorola PowerPC 601
4581 602 Motorola PowerPC 602
4582 603 Motorola/IBM PowerPC 603 or 603e
4583 604 Motorola PowerPC 604 or 604e
4584 750 Motorola/IBM PowerPC 750 or 750
4586 At the moment, this command just tells GDB what to name the
4587 special-purpose processor registers. Since almost all the affected
4588 registers are inaccessible to user-level programs, this command is
4589 only useful for remote debugging in its present form.
4593 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4594 more extensive support for HP-UX. Added features include shared
4595 library support, kernel threads and hardware watchpoints for 11.00,
4596 support for HP's ANSI C and C++ compilers, and a compatibility mode
4597 for xdb and dbx commands.
4601 HP's donation includes the new concept of catchpoints, which is a
4602 generalization of the old catch command. On HP-UX, it is now possible
4603 to catch exec, fork, and vfork, as well as library loading.
4605 This means that the existing catch command has changed; its first
4606 argument now specifies the type of catch to be set up. See the
4607 output of "help catch" for a list of catchpoint types.
4609 * Debugging across forks
4611 On HP-UX, you can choose which process to debug when a fork() happens
4616 HP has donated a curses-based terminal user interface (TUI). To get
4617 it, build with --enable-tui. Although this can be enabled for any
4618 configuration, at present it only works for native HP debugging.
4620 * GDB remote protocol additions
4622 A new protocol packet 'X' that writes binary data is now available.
4623 Default behavior is to try 'X', then drop back to 'M' if the stub
4624 fails to respond. The settable variable `remotebinarydownload'
4625 allows explicit control over the use of 'X'.
4627 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4628 full 64-bit address. The command
4630 set remoteaddresssize 32
4632 can be used to revert to the old behaviour. For existing remote stubs
4633 the change should not be noticed, as the additional address information
4636 In order to assist in debugging stubs, you may use the maintenance
4637 command `packet' to send any text string to the stub. For instance,
4639 maint packet heythere
4641 sends the packet "$heythere#<checksum>". Note that it is very easy to
4642 disrupt a debugging session by sending the wrong packet at the wrong
4645 The compare-sections command allows you to compare section data on the
4646 target to what is in the executable file without uploading or
4647 downloading, by comparing CRC checksums.
4649 * Tracing can collect general expressions
4651 You may now collect general expressions at tracepoints. This requires
4652 further additions to the target-side stub; see tracepoint.c and
4653 doc/agentexpr.texi for further details.
4655 * mask-address variable for Mips
4657 For Mips targets, you may control the zeroing of the upper 32 bits of
4658 a 64-bit address by entering `set mask-address on'. This is mainly
4659 of interest to users of embedded R4xxx and R5xxx processors.
4661 * Higher serial baud rates
4663 GDB's serial code now allows you to specify baud rates 57600, 115200,
4664 230400, and 460800 baud. (Note that your host system may not be able
4665 to achieve all of these rates.)
4669 The i960 configuration now includes an initial implementation of a
4670 builtin simulator, contributed by Jim Wilson.
4673 *** Changes in GDB-4.17:
4675 * New native configurations
4677 Alpha GNU/Linux alpha*-*-linux*
4678 Unixware 2.x i[3456]86-unixware2*
4679 Irix 6.x mips*-sgi-irix6*
4680 PowerPC GNU/Linux powerpc-*-linux*
4681 PowerPC Solaris powerpcle-*-solaris*
4682 Sparc GNU/Linux sparc-*-linux*
4683 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4687 Argonaut Risc Chip (ARC) arc-*-*
4688 Hitachi H8/300S h8300*-*-*
4689 Matsushita MN10200 w/simulator mn10200-*-*
4690 Matsushita MN10300 w/simulator mn10300-*-*
4691 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4692 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4693 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4694 Mitsubishi D10V w/simulator d10v-*-*
4695 Mitsubishi M32R/D w/simulator m32r-*-elf*
4696 Tsqware Sparclet sparclet-*-*
4697 NEC V850 w/simulator v850-*-*
4699 * New debugging protocols
4701 ARM with RDI protocol arm*-*-*
4702 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4703 DDB and LSI variants of PMON protocol mips*-*-*
4704 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4705 PowerPC with SDS protocol powerpc{,le}-*-eabi
4706 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4710 All configurations can now understand and use the DWARF 2 debugging
4711 format. The choice is automatic, if the symbol file contains DWARF 2
4716 GDB now includes basic Java language support. This support is
4717 only useful with Java compilers that produce native machine code.
4719 * solib-absolute-prefix and solib-search-path
4721 For SunOS and SVR4 shared libraries, you may now set the prefix for
4722 loading absolute shared library symbol files, and the search path for
4723 locating non-absolute shared library symbol files.
4725 * Live range splitting
4727 GDB can now effectively debug code for which GCC has performed live
4728 range splitting as part of its optimization. See gdb/doc/LRS for
4729 more details on the expected format of the stabs information.
4733 GDB's support for the GNU Hurd, including thread debugging, has been
4734 updated to work with current versions of the Hurd.
4738 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4739 instruction set. ARM GDB automatically detects when Thumb
4740 instructions are in use, and adjusts disassembly and backtracing
4745 GDB's MIPS target configurations now handle the MIP16 16-bit
4750 GDB now includes support for overlays; if an executable has been
4751 linked such that multiple sections are based at the same address, GDB
4752 will decide which section to use for symbolic info. You can choose to
4753 control the decision manually, using overlay commands, or implement
4754 additional target-side support and use "overlay load-target" to bring
4755 in the overlay mapping. Do "help overlay" for more detail.
4759 The command "info symbol <address>" displays information about
4760 the symbol at the specified address.
4764 The standard remote protocol now includes an extension that allows
4765 asynchronous collection and display of trace data. This requires
4766 extensive support in the target-side debugging stub. Tracing mode
4767 includes a new interaction mode in GDB and new commands: see the
4768 file tracepoint.c for more details.
4772 Configurations for embedded MIPS now include a simulator contributed
4773 by Cygnus Solutions. The simulator supports the instruction sets
4774 of most MIPS variants.
4778 Sparc configurations may now include the ERC32 simulator contributed
4779 by the European Space Agency. The simulator is not built into
4780 Sparc targets by default; configure with --enable-sim to include it.
4784 For target configurations that may include multiple variants of a
4785 basic architecture (such as MIPS and SH), you may now set the
4786 architecture explicitly. "set arch" sets, "info arch" lists
4787 the possible architectures.
4789 *** Changes in GDB-4.16:
4791 * New native configurations
4793 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4794 M68K NetBSD m68k-*-netbsd*
4795 PowerPC AIX 4.x powerpc-*-aix*
4796 PowerPC MacOS powerpc-*-macos*
4797 PowerPC Windows NT powerpcle-*-cygwin32
4798 RS/6000 AIX 4.x rs6000-*-aix4*
4802 ARM with RDP protocol arm-*-*
4803 I960 with MON960 i960-*-coff
4804 MIPS VxWorks mips*-*-vxworks*
4805 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4806 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4808 Matra Sparclet sparclet-*-*
4812 The powerpc-eabi configuration now includes the PSIM simulator,
4813 contributed by Andrew Cagney, with assistance from Mike Meissner.
4814 PSIM is a very elaborate model of the PowerPC, including not only
4815 basic instruction set execution, but also details of execution unit
4816 performance and I/O hardware. See sim/ppc/README for more details.
4820 GDB now works with Solaris 2.5.
4822 * Windows 95/NT native
4824 GDB will now work as a native debugger on Windows 95 and Windows NT.
4825 To build it from source, you must use the "gnu-win32" environment,
4826 which uses a DLL to emulate enough of Unix to run the GNU tools.
4827 Further information, binaries, and sources are available at
4828 ftp.cygnus.com, under pub/gnu-win32.
4830 * dont-repeat command
4832 If a user-defined command includes the command `dont-repeat', then the
4833 command will not be repeated if the user just types return. This is
4834 useful if the command is time-consuming to run, so that accidental
4835 extra keystrokes don't run the same command many times.
4837 * Send break instead of ^C
4839 The standard remote protocol now includes an option to send a break
4840 rather than a ^C to the target in order to interrupt it. By default,
4841 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4843 * Remote protocol timeout
4845 The standard remote protocol includes a new variable `remotetimeout'
4846 that allows you to set the number of seconds before GDB gives up trying
4847 to read from the target. The default value is 2.
4849 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4851 By default GDB will automatically keep track of objects as they are
4852 loaded and unloaded by the dynamic linker. By using the command `set
4853 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4854 when shared library events occur, thus allowing you to set breakpoints
4855 in shared libraries which are explicitly loaded by the inferior.
4857 Note this feature does not work on hpux8. On hpux9 you must link
4858 /usr/lib/end.o into your program. This feature should work
4859 automatically on hpux10.
4861 * Irix 5.x hardware watchpoint support
4863 Irix 5 configurations now support the use of hardware watchpoints.
4865 * Mips protocol "SYN garbage limit"
4867 When debugging a Mips target using the `target mips' protocol, you
4868 may set the number of characters that GDB will ignore by setting
4869 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4870 every character. The default value is 1050.
4872 * Recording and replaying remote debug sessions
4874 If you set `remotelogfile' to the name of a file, gdb will write to it
4875 a recording of a remote debug session. This recording may then be
4876 replayed back to gdb using "gdbreplay". See gdbserver/README for
4877 details. This is useful when you have a problem with GDB while doing
4878 remote debugging; you can make a recording of the session and send it
4879 to someone else, who can then recreate the problem.
4881 * Speedups for remote debugging
4883 GDB includes speedups for downloading and stepping MIPS systems using
4884 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4885 and more efficient S-record downloading.
4887 * Memory use reductions and statistics collection
4889 GDB now uses less memory and reports statistics about memory usage.
4890 Try the `maint print statistics' command, for example.
4892 *** Changes in GDB-4.15:
4894 * Psymtabs for XCOFF
4896 The symbol reader for AIX GDB now uses partial symbol tables. This
4897 can greatly improve startup time, especially for large executables.
4899 * Remote targets use caching
4901 Remote targets now use a data cache to speed up communication with the
4902 remote side. The data cache could lead to incorrect results because
4903 it doesn't know about volatile variables, thus making it impossible to
4904 debug targets which use memory mapped I/O devices. `set remotecache
4905 off' turns the the data cache off.
4907 * Remote targets may have threads
4909 The standard remote protocol now includes support for multiple threads
4910 in the target system, using new protocol commands 'H' and 'T'. See
4911 gdb/remote.c for details.
4915 If GDB is configured with `--enable-netrom', then it will include
4916 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4917 acts as though it is a bank of ROM on the target board, but you can
4918 write into it over the network. GDB's support consists only of
4919 support for fast loading into the emulated ROM; to debug, you must use
4920 another protocol, such as standard remote protocol. The usual
4921 sequence is something like
4923 target nrom <netrom-hostname>
4925 target remote <netrom-hostname>:1235
4929 GDB now includes support for the Apple Macintosh, as a host only. It
4930 may be run as either an MPW tool or as a standalone application, and
4931 it can debug through the serial port. All the usual GDB commands are
4932 available, but to the target command, you must supply "serial" as the
4933 device type instead of "/dev/ttyXX". See mpw-README in the main
4934 directory for more information on how to build. The MPW configuration
4935 scripts */mpw-config.in support only a few targets, and only the
4936 mips-idt-ecoff target has been tested.
4940 GDB configuration now uses autoconf. This is not user-visible,
4941 but does simplify configuration and building.
4945 GDB now supports hpux10.
4947 *** Changes in GDB-4.14:
4949 * New native configurations
4951 x86 FreeBSD i[345]86-*-freebsd
4952 x86 NetBSD i[345]86-*-netbsd
4953 NS32k NetBSD ns32k-*-netbsd
4954 Sparc NetBSD sparc-*-netbsd
4958 A29K VxWorks a29k-*-vxworks
4959 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4960 CPU32 EST-300 emulator m68*-*-est*
4961 PowerPC ELF powerpc-*-elf
4964 * Alpha OSF/1 support for procfs
4966 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4967 possible to attach to running processes. As the mounting of the /proc
4968 filesystem is optional on the Alpha, GDB automatically determines
4969 the availability of /proc during startup. This can lead to problems
4970 if /proc is unmounted after GDB has been started.
4972 * Arguments to user-defined commands
4974 User commands may accept up to 10 arguments separated by whitespace.
4975 Arguments are accessed within the user command via $arg0..$arg9. A
4978 print $arg0 + $arg1 + $arg2
4980 To execute the command use:
4983 Defines the command "adder" which prints the sum of its three arguments.
4984 Note the arguments are text substitutions, so they may reference variables,
4985 use complex expressions, or even perform inferior function calls.
4987 * New `if' and `while' commands
4989 This makes it possible to write more sophisticated user-defined
4990 commands. Both commands take a single argument, which is the
4991 expression to evaluate, and must be followed by the commands to
4992 execute, one per line, if the expression is nonzero, the list being
4993 terminated by the word `end'. The `if' command list may include an
4994 `else' word, which causes the following commands to be executed only
4995 if the expression is zero.
4997 * Fortran source language mode
4999 GDB now includes partial support for Fortran 77. It will recognize
5000 Fortran programs and can evaluate a subset of Fortran expressions, but
5001 variables and functions may not be handled correctly. GDB will work
5002 with G77, but does not yet know much about symbols emitted by other
5005 * Better HPUX support
5007 Most debugging facilities now work on dynamic executables for HPPAs
5008 running hpux9 or later. You can attach to running dynamically linked
5009 processes, but by default the dynamic libraries will be read-only, so
5010 for instance you won't be able to put breakpoints in them. To change
5011 that behavior do the following before running the program:
5017 This will cause the libraries to be mapped private and read-write.
5018 To revert to the normal behavior, do this:
5024 You cannot set breakpoints or examine data in the library until after
5025 the library is loaded if the function/data symbols do not have
5028 GDB can now also read debug symbols produced by the HP C compiler on
5029 HPPAs (sorry, no C++, Fortran or 68k support).
5031 * Target byte order now dynamically selectable
5033 You can choose which byte order to use with a target system, via the
5034 commands "set endian big" and "set endian little", and you can see the
5035 current setting by using "show endian". You can also give the command
5036 "set endian auto", in which case GDB will use the byte order
5037 associated with the executable. Currently, only embedded MIPS
5038 configurations support dynamic selection of target byte order.
5040 * New DOS host serial code
5042 This version uses DPMI interrupts to handle buffered I/O, so you
5043 no longer need to run asynctsr when debugging boards connected to
5046 *** Changes in GDB-4.13:
5048 * New "complete" command
5050 This lists all the possible completions for the rest of the line, if it
5051 were to be given as a command itself. This is intended for use by emacs.
5053 * Trailing space optional in prompt
5055 "set prompt" no longer adds a space for you after the prompt you set. This
5056 allows you to set a prompt which ends in a space or one that does not.
5058 * Breakpoint hit counts
5060 "info break" now displays a count of the number of times the breakpoint
5061 has been hit. This is especially useful in conjunction with "ignore"; you
5062 can ignore a large number of breakpoint hits, look at the breakpoint info
5063 to see how many times the breakpoint was hit, then run again, ignoring one
5064 less than that number, and this will get you quickly to the last hit of
5067 * Ability to stop printing at NULL character
5069 "set print null-stop" will cause GDB to stop printing the characters of
5070 an array when the first NULL is encountered. This is useful when large
5071 arrays actually contain only short strings.
5073 * Shared library breakpoints
5075 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5076 breakpoints in shared libraries before the executable is run.
5078 * Hardware watchpoints
5080 There is a new hardware breakpoint for the watch command for sparclite
5081 targets. See gdb/sparclite/hw_breakpoint.note.
5083 Hardware watchpoints are also now supported under GNU/Linux.
5087 Annotations have been added. These are for use with graphical interfaces,
5088 and are still experimental. Currently only gdba.el uses these.
5090 * Improved Irix 5 support
5092 GDB now works properly with Irix 5.2.
5094 * Improved HPPA support
5096 GDB now works properly with the latest GCC and GAS.
5098 * New native configurations
5100 Sequent PTX4 i[34]86-sequent-ptx4
5101 HPPA running OSF/1 hppa*-*-osf*
5102 Atari TT running SVR4 m68*-*-sysv4*
5103 RS/6000 LynxOS rs6000-*-lynxos*
5107 OS/9000 i[34]86-*-os9k
5108 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5111 * Hitachi SH7000 and E7000-PC ICE support
5113 There is now support for communicating with the Hitachi E7000-PC ICE.
5114 This is available automatically when GDB is configured for the SH.
5118 As usual, a variety of small fixes and improvements, both generic
5119 and configuration-specific. See the ChangeLog for more detail.
5121 *** Changes in GDB-4.12:
5123 * Irix 5 is now supported
5127 GDB-4.12 on the HPPA has a number of changes which make it unable
5128 to debug the output from the currently released versions of GCC and
5129 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5130 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5131 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5134 *** Changes in GDB-4.11:
5136 * User visible changes:
5140 The "set remotedebug" option is now consistent between the mips remote
5141 target, remote targets using the gdb-specific protocol, UDI (AMD's
5142 debug protocol for the 29k) and the 88k bug monitor. It is now an
5143 integer specifying a debug level (normally 0 or 1, but 2 means more
5144 debugging info for the mips target).
5146 * DEC Alpha native support
5148 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5149 debug info, but GDB works fairly well with the DEC compiler and should
5150 work with a future GCC release. See the README file for a few
5151 Alpha-specific notes.
5153 * Preliminary thread implementation
5155 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5157 * LynxOS native and target support for 386
5159 This release has been hosted on LynxOS 2.2, and also can be configured
5160 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5163 * Improvements in C++ mangling/demangling.
5165 This release has much better g++ debugging, specifically in name
5166 mangling/demangling, virtual function calls, print virtual table,
5167 call methods, ...etc.
5169 *** Changes in GDB-4.10:
5171 * User visible changes:
5173 Remote debugging using the GDB-specific (`target remote') protocol now
5174 supports the `load' command. This is only useful if you have some
5175 other way of getting the stub to the target system, and you can put it
5176 somewhere in memory where it won't get clobbered by the download.
5178 Filename completion now works.
5180 When run under emacs mode, the "info line" command now causes the
5181 arrow to point to the line specified. Also, "info line" prints
5182 addresses in symbolic form (as well as hex).
5184 All vxworks based targets now support a user settable option, called
5185 vxworks-timeout. This option represents the number of seconds gdb
5186 should wait for responses to rpc's. You might want to use this if
5187 your vxworks target is, perhaps, a slow software simulator or happens
5188 to be on the far side of a thin network line.
5192 This release contains support for using a DEC alpha as a GDB host for
5193 cross debugging. Native alpha debugging is not supported yet.
5196 *** Changes in GDB-4.9:
5200 This is the first GDB release which is accompanied by a matching testsuite.
5201 The testsuite requires installation of dejagnu, which should be available
5202 via ftp from most sites that carry GNU software.
5206 'Cfront' style demangling has had its name changed to 'ARM' style, to
5207 emphasize that it was written from the specifications in the C++ Annotated
5208 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5209 disclaimers, it still generated too much confusion with users attempting to
5210 use gdb with AT&T cfront.
5214 GDB now uses a standard remote interface to a simulator library.
5215 So far, the library contains simulators for the Zilog Z8001/2, the
5216 Hitachi H8/300, H8/500 and Super-H.
5218 * New targets supported
5220 H8/300 simulator h8300-hitachi-hms or h8300hms
5221 H8/500 simulator h8500-hitachi-hms or h8500hms
5222 SH simulator sh-hitachi-hms or sh
5223 Z8000 simulator z8k-zilog-none or z8ksim
5224 IDT MIPS board over serial line mips-idt-ecoff
5226 Cross-debugging to GO32 targets is supported. It requires a custom
5227 version of the i386-stub.c module which is integrated with the
5228 GO32 memory extender.
5230 * New remote protocols
5232 MIPS remote debugging protocol.
5234 * New source languages supported
5236 This version includes preliminary support for Chill, a Pascal like language
5237 used by telecommunications companies. Chill support is also being integrated
5238 into the GNU compiler, but we don't know when it will be publically available.
5241 *** Changes in GDB-4.8:
5243 * HP Precision Architecture supported
5245 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5246 version of this support was available as a set of patches from the
5247 University of Utah. GDB does not support debugging of programs
5248 compiled with the HP compiler, because HP will not document their file
5249 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5250 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5252 Many problems in the preliminary version have been fixed.
5254 * Faster and better demangling
5256 We have improved template demangling and fixed numerous bugs in the GNU style
5257 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5258 character types (wchar_t) are now supported. Demangling of each symbol is now
5259 only done once, and is cached when the symbol table for a file is read in.
5260 This results in a small increase in memory usage for C programs, a moderate
5261 increase in memory usage for C++ programs, and a fantastic speedup in
5264 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5265 from the specifications in the Annotated Reference Manual, which AT&T's
5266 compiler does not actually implement.
5268 * G++ multiple inheritance compiler problem
5270 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5271 inheritance lattices was reworked to properly discover ambiguities. We
5272 recently found an example which causes this new algorithm to fail in a
5273 very subtle way, producing bad debug information for those classes.
5274 The file 'gcc.patch' (in this directory) can be applied to gcc to
5275 circumvent the problem. A future GCC release will contain a complete
5278 The previous G++ debug info problem (mentioned below for the gdb-4.7
5279 release) is fixed in gcc version 2.3.2.
5281 * Improved configure script
5283 The `configure' script will now attempt to guess your system type if
5284 you don't supply a host system type. The old scheme of supplying a
5285 host system triplet is preferable over using this. All the magic is
5286 done in the new `config.guess' script. Examine it for details.
5288 We have also brought our configure script much more in line with the FSF's
5289 version. It now supports the --with-xxx options. In particular,
5290 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5291 The resulting GDB will not be able to read arbitrary object file formats --
5292 only the format ``expected'' to be used on the configured target system.
5293 We hope to make this the default in a future release.
5295 * Documentation improvements
5297 There's new internal documentation on how to modify GDB, and how to
5298 produce clean changes to the code. We implore people to read it
5299 before submitting changes.
5301 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5302 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5303 `info' files are also provided. To build `info' files from scratch,
5304 you will need the latest `makeinfo' release, which will be available in
5305 a future texinfo-X.Y release.
5307 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5308 We're not sure exactly which versions have this problem, but it has
5309 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5310 or better. If that isn't possible, there is a patch in
5311 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5312 around this problem.
5316 GDB now supports array constants that can be used in expressions typed in by
5317 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5318 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5321 The new directory `gdb/sparclite' contains a program that demonstrates
5322 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5324 * New native hosts supported
5326 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5327 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5329 * New targets supported
5331 AMD 29k family via UDI a29k-amd-udi or udi29k
5333 * New file formats supported
5335 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5336 HPUX core files, and SCO 3.2v2 core files.
5340 Attaching to processes now works again; thanks for the many bug reports.
5342 We have also stomped on a bunch of core dumps caused by
5343 printf_filtered("%s") problems.
5345 We eliminated a copyright problem on the rpc and ptrace header files
5346 for VxWorks, which was discovered at the last minute during the 4.7
5347 release. You should now be able to build a VxWorks GDB.
5349 You can now interrupt gdb while an attached process is running. This
5350 will cause the attached process to stop, and give control back to GDB.
5352 We fixed problems caused by using too many file descriptors
5353 for reading symbols from object files and libraries. This was
5354 especially a problem for programs that used many (~100) shared
5357 The `step' command now only enters a subroutine if there is line number
5358 information for the subroutine. Otherwise it acts like the `next'
5359 command. Previously, `step' would enter subroutines if there was
5360 any debugging information about the routine. This avoids problems
5361 when using `cc -g1' on MIPS machines.
5363 * Internal improvements
5365 GDB's internal interfaces have been improved to make it easier to support
5366 debugging of multiple languages in the future.
5368 GDB now uses a common structure for symbol information internally.
5369 Minimal symbols (derived from linkage symbols in object files), partial
5370 symbols (from a quick scan of debug information), and full symbols
5371 contain a common subset of information, making it easier to write
5372 shared code that handles any of them.
5374 * New command line options
5376 We now accept --silent as an alias for --quiet.
5380 The memory-mapped-malloc library is now licensed under the GNU Library
5381 General Public License.
5383 *** Changes in GDB-4.7:
5385 * Host/native/target split
5387 GDB has had some major internal surgery to untangle the support for
5388 hosts and remote targets. Now, when you configure GDB for a remote
5389 target, it will no longer load in all of the support for debugging
5390 local programs on the host. When fully completed and tested, this will
5391 ensure that arbitrary host/target combinations are possible.
5393 The primary conceptual shift is to separate the non-portable code in
5394 GDB into three categories. Host specific code is required any time GDB
5395 is compiled on that host, regardless of the target. Target specific
5396 code relates to the peculiarities of the target, but can be compiled on
5397 any host. Native specific code is everything else: it can only be
5398 built when the host and target are the same system. Child process
5399 handling and core file support are two common `native' examples.
5401 GDB's use of /proc for controlling Unix child processes is now cleaner.
5402 It has been split out into a single module under the `target_ops' vector,
5403 plus two native-dependent functions for each system that uses /proc.
5405 * New hosts supported
5407 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5408 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5409 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5411 * New targets supported
5413 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5414 68030 and CPU32 m68030-*-*, m68332-*-*
5416 * New native hosts supported
5418 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5419 (386bsd is not well tested yet)
5420 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5422 * New file formats supported
5424 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5425 supports reading of `a.out.adobe' object files, which are an a.out
5426 format extended with minimal information about multiple sections.
5430 `show copying' is the same as the old `info copying'.
5431 `show warranty' is the same as `info warrantee'.
5432 These were renamed for consistency. The old commands continue to work.
5434 `info handle' is a new alias for `info signals'.
5436 You can now define pre-command hooks, which attach arbitrary command
5437 scripts to any command. The commands in the hook will be executed
5438 prior to the user's command. You can also create a hook which will be
5439 executed whenever the program stops. See gdb.texinfo.
5443 We now deal with Cfront style name mangling, and can even extract type
5444 info from mangled symbols. GDB can automatically figure out which
5445 symbol mangling style your C++ compiler uses.
5447 Calling of methods and virtual functions has been improved as well.
5451 The crash that occured when debugging Sun Ansi-C compiled binaries is
5452 fixed. This was due to mishandling of the extra N_SO stabs output
5455 We also finally got Ultrix 4.2 running in house, and fixed core file
5456 support, with help from a dozen people on the net.
5458 John M. Farrell discovered that the reason that single-stepping was so
5459 slow on all of the Mips based platforms (primarily SGI and DEC) was
5460 that we were trying to demangle and lookup a symbol used for internal
5461 purposes on every instruction that was being stepped through. Changing
5462 the name of that symbol so that it couldn't be mistaken for a C++
5463 mangled symbol sped things up a great deal.
5465 Rich Pixley sped up symbol lookups in general by getting much smarter
5466 about when C++ symbol mangling is necessary. This should make symbol
5467 completion (TAB on the command line) much faster. It's not as fast as
5468 we'd like, but it's significantly faster than gdb-4.6.
5472 A new user controllable variable 'call_scratch_address' can
5473 specify the location of a scratch area to be used when GDB
5474 calls a function in the target. This is necessary because the
5475 usual method of putting the scratch area on the stack does not work
5476 in systems that have separate instruction and data spaces.
5478 We integrated changes to support the 29k UDI (Universal Debugger
5479 Interface), but discovered at the last minute that we didn't have all
5480 of the appropriate copyright paperwork. We are working with AMD to
5481 resolve this, and hope to have it available soon.
5485 We have sped up the remote serial line protocol, especially for targets
5486 with lots of registers. It now supports a new `expedited status' ('T')
5487 message which can be used in place of the existing 'S' status message.
5488 This allows the remote stub to send only the registers that GDB
5489 needs to make a quick decision about single-stepping or conditional
5490 breakpoints, eliminating the need to fetch the entire register set for
5491 each instruction being stepped through.
5493 The GDB remote serial protocol now implements a write-through cache for
5494 registers, only re-reading the registers if the target has run.
5496 There is also a new remote serial stub for SPARC processors. You can
5497 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5498 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5499 processor with a serial port.
5503 Configure.in files have become much easier to read and modify. A new
5504 `table driven' format makes it more obvious what configurations are
5505 supported, and what files each one uses.
5509 There is a new opcodes library which will eventually contain all of the
5510 disassembly routines and opcode tables. At present, it only contains
5511 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5512 disassembler (binutils/objdump) to share these routines.
5514 The libiberty library is now copylefted under the GNU Library General
5515 Public License. This allows more liberal use, and was done so libg++
5516 can use it. This makes no difference to GDB, since the Library License
5517 grants all the rights from the General Public License.
5521 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5522 reference to the stabs symbol info used by the debugger. It is (as far
5523 as we know) the only published document on this fascinating topic. We
5524 encourage you to read it, compare it to the stabs information on your
5525 system, and send improvements on the document in general (to
5526 bug-gdb@prep.ai.mit.edu).
5528 And, of course, many bugs have been fixed.
5531 *** Changes in GDB-4.6:
5533 * Better support for C++ function names
5535 GDB now accepts as input the "demangled form" of C++ overloaded function
5536 names and member function names, and can do command completion on such names
5537 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5538 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5539 Make use of command completion, it is your friend.
5541 GDB also now accepts a variety of C++ mangled symbol formats. They are
5542 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5543 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5544 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5545 for the list of formats.
5547 * G++ symbol mangling problem
5549 Recent versions of gcc have a bug in how they emit debugging information for
5550 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5551 directory) can be applied to gcc to fix the problem. Alternatively, if you
5552 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5553 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5554 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5557 * New 'maintenance' command
5559 All of the commands related to hacking GDB internals have been moved out of
5560 the main command set, and now live behind the 'maintenance' command. This
5561 can also be abbreviated as 'mt'. The following changes were made:
5563 dump-me -> maintenance dump-me
5564 info all-breakpoints -> maintenance info breakpoints
5565 printmsyms -> maintenance print msyms
5566 printobjfiles -> maintenance print objfiles
5567 printpsyms -> maintenance print psymbols
5568 printsyms -> maintenance print symbols
5570 The following commands are new:
5572 maintenance demangle Call internal GDB demangler routine to
5573 demangle a C++ link name and prints the result.
5574 maintenance print type Print a type chain for a given symbol
5576 * Change to .gdbinit file processing
5578 We now read the $HOME/.gdbinit file before processing the argv arguments
5579 (e.g. reading symbol files or core files). This allows global parameters to
5580 be set, which will apply during the symbol reading. The ./.gdbinit is still
5581 read after argv processing.
5583 * New hosts supported
5585 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5587 GNU/Linux support i386-unknown-linux or linux
5589 We are also including code to support the HP/PA running BSD and HPUX. This
5590 is almost guaranteed not to work, as we didn't have time to test or build it
5591 for this release. We are including it so that the more adventurous (or
5592 masochistic) of you can play with it. We also had major problems with the
5593 fact that the compiler that we got from HP doesn't support the -g option.
5596 * New targets supported
5598 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5600 * More smarts about finding #include files
5602 GDB now remembers the compilation directory for all include files, and for
5603 all files from which C is generated (like yacc and lex sources). This
5604 greatly improves GDB's ability to find yacc/lex sources, and include files,
5605 especially if you are debugging your program from a directory different from
5606 the one that contains your sources.
5608 We also fixed a bug which caused difficulty with listing and setting
5609 breakpoints in include files which contain C code. (In the past, you had to
5610 try twice in order to list an include file that you hadn't looked at before.)
5612 * Interesting infernals change
5614 GDB now deals with arbitrary numbers of sections, where the symbols for each
5615 section must be relocated relative to that section's landing place in the
5616 target's address space. This work was needed to support ELF with embedded
5617 stabs used by Solaris-2.0.
5619 * Bug fixes (of course!)
5621 There have been loads of fixes for the following things:
5622 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5623 i960, stabs, DOS(GO32), procfs, etc...
5625 See the ChangeLog for details.
5627 *** Changes in GDB-4.5:
5629 * New machines supported (host and target)
5631 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5633 SGI Irix-4.x mips-sgi-irix4 or iris4
5635 * New malloc package
5637 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5638 Mmalloc is capable of handling mutiple heaps of memory. It is also
5639 capable of saving a heap to a file, and then mapping it back in later.
5640 This can be used to greatly speedup the startup of GDB by using a
5641 pre-parsed symbol table which lives in a mmalloc managed heap. For
5642 more details, please read mmalloc/mmalloc.texi.
5646 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5647 'help info proc' for details.
5649 * MIPS ecoff symbol table format
5651 The code that reads MIPS symbol table format is now supported on all hosts.
5652 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5655 * File name changes for MS-DOS
5657 Many files in the config directories have been renamed to make it easier to
5658 support GDB on MS-DOSe systems (which have very restrictive file name
5659 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5660 environment) is close to working but has some remaining problems. Note
5661 that debugging of DOS programs is not supported, due to limitations
5662 in the ``operating system'', but it can be used to host cross-debugging.
5664 * Cross byte order fixes
5666 Many fixes have been made to support cross debugging of Sparc and MIPS
5667 targets from hosts whose byte order differs.
5669 * New -mapped and -readnow options
5671 If memory-mapped files are available on your system through the 'mmap'
5672 system call, you can use the -mapped option on the `file' or
5673 `symbol-file' commands to cause GDB to write the symbols from your
5674 program into a reusable file. If the program you are debugging is
5675 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5676 Future GDB debugging sessions will notice the presence of this file,
5677 and will quickly map in symbol information from it, rather than reading
5678 the symbol table from the executable program. Using the '-mapped'
5679 option in a GDB `file' or `symbol-file' command has the same effect as
5680 starting GDB with the '-mapped' command-line option.
5682 You can cause GDB to read the entire symbol table immediately by using
5683 the '-readnow' option with any of the commands that load symbol table
5684 information (or on the GDB command line). This makes the command
5685 slower, but makes future operations faster.
5687 The -mapped and -readnow options are typically combined in order to
5688 build a `fred.syms' file that contains complete symbol information.
5689 A simple GDB invocation to do nothing but build a `.syms' file for future
5692 gdb -batch -nx -mapped -readnow programname
5694 The `.syms' file is specific to the host machine on which GDB is run.
5695 It holds an exact image of GDB's internal symbol table. It cannot be
5696 shared across multiple host platforms.
5698 * longjmp() handling
5700 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5701 siglongjmp() without losing control. This feature has not yet been ported to
5702 all systems. It currently works on many 386 platforms, all MIPS-based
5703 platforms (SGI, DECstation, etc), and Sun3/4.
5707 Preliminary work has been put in to support the new Solaris OS from Sun. At
5708 this time, it can control and debug processes, but it is not capable of
5713 As always, many many bug fixes. The major areas were with g++, and mipsread.
5714 People using the MIPS-based platforms should experience fewer mysterious
5715 crashes and trashed symbol tables.
5717 *** Changes in GDB-4.4:
5719 * New machines supported (host and target)
5721 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5723 BSD Reno on Vax vax-dec-bsd
5724 Ultrix on Vax vax-dec-ultrix
5726 * New machines supported (target)
5728 AMD 29000 embedded, using EBMON a29k-none-none
5732 GDB continues to improve its handling of C++. `References' work better.
5733 The demangler has also been improved, and now deals with symbols mangled as
5734 per the Annotated C++ Reference Guide.
5736 GDB also now handles `stabs' symbol information embedded in MIPS
5737 `ecoff' symbol tables. Since the ecoff format was not easily
5738 extensible to handle new languages such as C++, this appeared to be a
5739 good way to put C++ debugging info into MIPS binaries. This option
5740 will be supported in the GNU C compiler, version 2, when it is
5743 * New features for SVR4
5745 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5746 shared libraries. Debugging dynamically linked programs should present
5747 only minor differences from debugging statically linked programs.
5749 The `info proc' command will print out information about any process
5750 on an SVR4 system (including the one you are debugging). At the moment,
5751 it prints the address mappings of the process.
5753 If you bring up GDB on another SVR4 system, please send mail to
5754 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5756 * Better dynamic linking support in SunOS
5758 Reading symbols from shared libraries which contain debugging symbols
5759 now works properly. However, there remain issues such as automatic
5760 skipping of `transfer vector' code during function calls, which
5761 make it harder to debug code in a shared library, than to debug the
5762 same code linked statically.
5766 GDB is now using the latest `getopt' routines from the FSF. This
5767 version accepts the -- prefix for options with long names. GDB will
5768 continue to accept the old forms (-option and +option) as well.
5769 Various single letter abbreviations for options have been explicity
5770 added to the option table so that they won't get overshadowed in the
5771 future by other options that begin with the same letter.
5775 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5776 Many assorted bugs have been handled. Many more remain to be handled.
5777 See the various ChangeLog files (primarily in gdb and bfd) for details.
5780 *** Changes in GDB-4.3:
5782 * New machines supported (host and target)
5784 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5785 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5786 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5788 * Almost SCO Unix support
5790 We had hoped to support:
5791 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5792 (except for core file support), but we discovered very late in the release
5793 that it has problems with process groups that render gdb unusable. Sorry
5794 about that. I encourage people to fix it and post the fixes.
5796 * Preliminary ELF and DWARF support
5798 GDB can read ELF object files on System V Release 4, and can handle
5799 debugging records for C, in DWARF format, in ELF files. This support
5800 is preliminary. If you bring up GDB on another SVR4 system, please
5801 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5806 GDB now uses the latest `readline' library. One user-visible change
5807 is that two tabs will list possible command completions, which previously
5808 required typing M-? (meta-question mark, or ESC ?).
5812 The `stepi' bug that many of you noticed has been squashed.
5813 Many bugs in C++ have been handled. Many more remain to be handled.
5814 See the various ChangeLog files (primarily in gdb and bfd) for details.
5816 * State of the MIPS world (in case you wondered):
5818 GDB can understand the symbol tables emitted by the compilers
5819 supplied by most vendors of MIPS-based machines, including DEC. These
5820 symbol tables are in a format that essentially nobody else uses.
5822 Some versions of gcc come with an assembler post-processor called
5823 mips-tfile. This program is required if you want to do source-level
5824 debugging of gcc-compiled programs. I believe FSF does not ship
5825 mips-tfile with gcc version 1, but it will eventually come with gcc
5828 Debugging of g++ output remains a problem. g++ version 1.xx does not
5829 really support it at all. (If you're lucky, you should be able to get
5830 line numbers and stack traces to work, but no parameters or local
5831 variables.) With some work it should be possible to improve the
5834 When gcc version 2 is released, you will have somewhat better luck.
5835 However, even then you will get confusing results for inheritance and
5838 We will eventually provide full debugging of g++ output on
5839 DECstations. This will probably involve some kind of stabs-in-ecoff
5840 encapulation, but the details have not been worked out yet.
5843 *** Changes in GDB-4.2:
5845 * Improved configuration
5847 Only one copy of `configure' exists now, and it is not self-modifying.
5848 Porting BFD is simpler.
5852 The `step' and `next' commands now only stop at the first instruction
5853 of a source line. This prevents the multiple stops that used to occur
5854 in switch statements, for-loops, etc. `Step' continues to stop if a
5855 function that has debugging information is called within the line.
5859 Lots of small bugs fixed. More remain.
5861 * New host supported (not target)
5863 Intel 386 PC clone running Mach i386-none-mach
5866 *** Changes in GDB-4.1:
5868 * Multiple source language support
5870 GDB now has internal scaffolding to handle several source languages.
5871 It determines the type of each source file from its filename extension,
5872 and will switch expression parsing and number formatting to match the
5873 language of the function in the currently selected stack frame.
5874 You can also specifically set the language to be used, with
5875 `set language c' or `set language modula-2'.
5879 GDB now has preliminary support for the GNU Modula-2 compiler,
5880 currently under development at the State University of New York at
5881 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5882 continue through the fall of 1991 and into 1992.
5884 Other Modula-2 compilers are currently not supported, and attempting to
5885 debug programs compiled with them will likely result in an error as the
5886 symbol table is read. Feel free to work on it, though!
5888 There are hooks in GDB for strict type checking and range checking,
5889 in the `Modula-2 philosophy', but they do not currently work.
5893 GDB can now write to executable and core files (e.g. patch
5894 a variable's value). You must turn this switch on, specify
5895 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5896 by assigning a new value to a variable. Modifications take
5899 * Automatic SunOS shared library reading
5901 When you run your program, GDB automatically determines where its
5902 shared libraries (if any) have been loaded, and reads their symbols.
5903 The `share' command is no longer needed. This also works when
5904 examining core files.
5908 You can specify the number of lines that the `list' command shows.
5911 * New machines supported (host and target)
5913 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5914 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5915 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5917 * New hosts supported (not targets)
5919 IBM RT/PC: romp-ibm-aix or rtpc
5921 * New targets supported (not hosts)
5923 AMD 29000 embedded with COFF a29k-none-coff
5924 AMD 29000 embedded with a.out a29k-none-aout
5925 Ultracomputer remote kernel debug a29k-nyu-kern
5927 * New remote interfaces
5933 *** Changes in GDB-4.0:
5937 Wide output is wrapped at good places to make the output more readable.
5939 Gdb now supports cross-debugging from a host machine of one type to a
5940 target machine of another type. Communication with the target system
5941 is over serial lines. The ``target'' command handles connecting to the
5942 remote system; the ``load'' command will download a program into the
5943 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5944 also supports debugging of realtime processes running under VxWorks,
5945 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5946 stub on the target system.
5948 New CPUs supported include the AMD 29000 and Intel 960.
5950 GDB now reads object files and symbol tables via a ``binary file''
5951 library, which allows a single copy of GDB to debug programs of multiple
5952 object file types such as a.out and coff.
5954 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5955 refcard.dvi and refcard.ps are available to format it).
5958 * Control-Variable user interface simplified
5960 All variables that control the operation of the debugger can be set
5961 by the ``set'' command, and displayed by the ``show'' command.
5963 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5964 ``Show prompt'' produces the response:
5965 Gdb's prompt is new-gdb=>.
5967 What follows are the NEW set commands. The command ``help set'' will
5968 print a complete list of old and new set commands. ``help set FOO''
5969 will give a longer description of the variable FOO. ``show'' will show
5970 all of the variable descriptions and their current settings.
5972 confirm on/off: Enables warning questions for operations that are
5973 hard to recover from, e.g. rerunning the program while
5974 it is already running. Default is ON.
5976 editing on/off: Enables EMACS style command line editing
5977 of input. Previous lines can be recalled with
5978 control-P, the current line can be edited with control-B,
5979 you can search for commands with control-R, etc.
5982 history filename NAME: NAME is where the gdb command history
5983 will be stored. The default is .gdb_history,
5984 or the value of the environment variable
5987 history size N: The size, in commands, of the command history. The
5988 default is 256, or the value of the environment variable
5991 history save on/off: If this value is set to ON, the history file will
5992 be saved after exiting gdb. If set to OFF, the
5993 file will not be saved. The default is OFF.
5995 history expansion on/off: If this value is set to ON, then csh-like
5996 history expansion will be performed on
5997 command line input. The default is OFF.
5999 radix N: Sets the default radix for input and output. It can be set
6000 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6001 in the current radix, so "set radix 10" is always a no-op.
6003 height N: This integer value is the number of lines on a page. Default
6004 is 24, the current `stty rows'' setting, or the ``li#''
6005 setting from the termcap entry matching the environment
6008 width N: This integer value is the number of characters on a line.
6009 Default is 80, the current `stty cols'' setting, or the ``co#''
6010 setting from the termcap entry matching the environment
6013 Note: ``set screensize'' is obsolete. Use ``set height'' and
6014 ``set width'' instead.
6016 print address on/off: Print memory addresses in various command displays,
6017 such as stack traces and structure values. Gdb looks
6018 more ``symbolic'' if you turn this off; it looks more
6019 ``machine level'' with it on. Default is ON.
6021 print array on/off: Prettyprint arrays. New convenient format! Default
6024 print demangle on/off: Print C++ symbols in "source" form if on,
6027 print asm-demangle on/off: Same, for assembler level printouts
6030 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6033 * Support for Epoch Environment.
6035 The epoch environment is a version of Emacs v18 with windowing. One
6036 new command, ``inspect'', is identical to ``print'', except that if you
6037 are running in the epoch environment, the value is printed in its own
6041 * Support for Shared Libraries
6043 GDB can now debug programs and core files that use SunOS shared libraries.
6044 Symbols from a shared library cannot be referenced
6045 before the shared library has been linked with the program (this
6046 happens after you type ``run'' and before the function main() is entered).
6047 At any time after this linking (including when examining core files
6048 from dynamically linked programs), gdb reads the symbols from each
6049 shared library when you type the ``sharedlibrary'' command.
6050 It can be abbreviated ``share''.
6052 sharedlibrary REGEXP: Load shared object library symbols for files
6053 matching a unix regular expression. No argument
6054 indicates to load symbols for all shared libraries.
6056 info sharedlibrary: Status of loaded shared libraries.
6061 A watchpoint stops execution of a program whenever the value of an
6062 expression changes. Checking for this slows down execution
6063 tremendously whenever you are in the scope of the expression, but is
6064 quite useful for catching tough ``bit-spreader'' or pointer misuse
6065 problems. Some machines such as the 386 have hardware for doing this
6066 more quickly, and future versions of gdb will use this hardware.
6068 watch EXP: Set a watchpoint (breakpoint) for an expression.
6070 info watchpoints: Information about your watchpoints.
6072 delete N: Deletes watchpoint number N (same as breakpoints).
6073 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6074 enable N: Re-enables watchpoint number N (same as breakpoints).
6077 * C++ multiple inheritance
6079 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6082 * C++ exception handling
6084 Gdb now supports limited C++ exception handling. Besides the existing
6085 ability to breakpoint on an exception handler, gdb can breakpoint on
6086 the raising of an exception (before the stack is peeled back to the
6089 catch FOO: If there is a FOO exception handler in the dynamic scope,
6090 set a breakpoint to catch exceptions which may be raised there.
6091 Multiple exceptions (``catch foo bar baz'') may be caught.
6093 info catch: Lists all exceptions which may be caught in the
6094 current stack frame.
6097 * Minor command changes
6099 The command ``call func (arg, arg, ...)'' now acts like the print
6100 command, except it does not print or save a value if the function's result
6101 is void. This is similar to dbx usage.
6103 The ``up'' and ``down'' commands now always print the frame they end up
6104 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6105 frames without printing.
6107 * New directory command
6109 'dir' now adds directories to the FRONT of the source search path.
6110 The path starts off empty. Source files that contain debug information
6111 about the directory in which they were compiled can be found even
6112 with an empty path; Sun CC and GCC include this information. If GDB can't
6113 find your source file in the current directory, type "dir .".
6115 * Configuring GDB for compilation
6117 For normal use, type ``./configure host''. See README or gdb.texinfo
6120 GDB now handles cross debugging. If you are remotely debugging between
6121 two different machines, type ``./configure host -target=targ''.
6122 Host is the machine where GDB will run; targ is the machine
6123 where the program that you are debugging will run.