1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.9
6 * Support for process record-replay and reverse debugging on aarch64*-linux*
7 targets has been added. GDB now supports recording of A64 instruction set
8 including advance SIMD instructions.
10 * Support for Sun's version of the "stabs" debug file format has been removed.
12 * GDB now honors the content of the file /proc/PID/coredump_filter
13 (PID is the process ID) on GNU/Linux systems. This file can be used
14 to specify the types of memory mappings that will be included in a
15 corefile. For more information, please refer to the manual page of
16 "core(5)". GDB also has a new command: "set use-coredump-filter
17 on|off". It allows to set whether GDB will read the content of the
18 /proc/PID/coredump_filter file when generating a corefile.
20 * The "info os" command on GNU/Linux can now display information on
22 "info os cpus" Listing of all cpus/cores on the system
24 * GDB has two new commands: "set serial parity odd|even|none" and
25 "show serial parity". These allows to set or show parity for the
28 * The "info source" command now displays the producer string if it was
29 present in the debug info. This typically includes the compiler version
30 and may include things like its command line arguments.
32 * The "info dll", an alias of the "info sharedlibrary" command,
33 is now available on all platforms.
35 * Directory names supplied to the "set sysroot" commands may be
36 prefixed with "target:" to tell GDB to access shared libraries from
37 the target system, be it local or remote. This replaces the prefix
38 "remote:". The default sysroot has been changed from "" to
39 "target:". "remote:" is automatically converted to "target:" for
40 backward compatibility.
42 * The system root specified by "set sysroot" will be prepended to the
43 filename of the main executable (if reported to GDB as absolute by
44 the operating system) when starting processes remotely, and when
45 attaching to already-running local or remote processes.
47 * GDB now supports automatic location and retrieval of executable
48 files from remote targets. Remote debugging can now be initiated
49 using only a "target remote" or "target extended-remote" command
50 (no "set sysroot" or "file" commands are required). See "New remote
53 * The "dump" command now supports verilog hex format.
55 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
57 * On GNU/Linux, GDB and gdbserver are now able to access executable
58 and shared library files without a "set sysroot" command when
59 attaching to processes running in different mount namespaces from
60 the debugger. This makes it possible to attach to processes in
61 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
62 See "New remote packets" below.
64 * The "tui reg" command now provides completion for all of the
65 available register groups, including target specific groups.
67 * The HISTSIZE environment variable is no longer read when determining
68 the size of GDB's command history. GDB now instead reads the dedicated
69 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
70 disables truncation of command history. Non-numeric values of GDBHISTSIZE
75 ** Memory ports can now be unbuffered.
79 ** gdb.Objfile objects have a new attribute "username",
80 which is the name of the objfile as specified by the user,
81 without, for example, resolving symlinks.
82 ** You can now write frame unwinders in Python.
83 ** gdb.Type objects have a new method "optimized_out",
84 returning optimized out gdb.Value instance of this type.
85 ** gdb.Value objects have new methods "reference_value" and
86 "const_value" which return a reference to the value and a
87 "const" version of the value respectively.
91 maint print symbol-cache
92 Print the contents of the symbol cache.
94 maint print symbol-cache-statistics
95 Print statistics of symbol cache usage.
97 maint flush-symbol-cache
98 Flush the contents of the symbol cache.
102 Start branch trace recording using Branch Trace Store (BTS) format.
105 Evaluate expression by using the compiler and print result.
109 Explicit commands for enabling and disabling tui mode.
112 set mpx bound on i386 and amd64
113 Support for bound table investigation on Intel(R) MPX enabled applications.
118 Renamed from "set debug dwarf2-die".
120 Renamed from "show debug dwarf2-die".
123 Renamed from "set debug dwarf2-read".
124 show debug dwarf-read
125 Renamed from "show debug dwarf2-read".
127 maint set dwarf always-disassemble
128 Renamed from "maint set dwarf2 always-disassemble".
129 maint show dwarf always-disassemble
130 Renamed from "maint show dwarf2 always-disassemble".
132 maint set dwarf max-cache-age
133 Renamed from "maint set dwarf2 max-cache-age".
134 maint show dwarf max-cache-age
135 Renamed from "maint show dwarf2 max-cache-age".
138 show debug dwarf-line
139 Control display of debugging info regarding DWARF line processing.
143 Set the maximum number of candidates to be considered during
144 completion. The default value is 200. This limit allows GDB
145 to avoid generating large completion lists, the computation of
146 which can cause the debugger to become temporarily unresponsive.
148 set history remove-duplicates
149 show history remove-duplicates
150 Control the removal of duplicate history entries.
152 maint set symbol-cache-size
153 maint show symbol-cache-size
154 Control the size of the symbol cache.
156 set|show record btrace bts buffer-size
157 Set and show the size of the ring buffer used for branch tracing in
159 The obtained size may differ from the requested size. Use "info
160 record" to see the obtained buffer size.
162 set debug linux-namespaces
163 show debug linux-namespaces
164 Control display of debugging info regarding Linux namespaces.
166 * The command 'thread apply all' can now support new option '-ascending'
167 to call its specified command for all threads in ascending order.
169 * Python/Guile scripting
171 ** GDB now supports auto-loading of Python/Guile scripts contained in the
172 special section named `.debug_gdb_scripts'.
176 qXfer:btrace-conf:read
177 Return the branch trace configuration for the current thread.
179 Qbtrace-conf:bts:size
180 Set the requested ring buffer size for branch tracing in BTS format.
183 Indicates a memory breakpoint instruction was executed, irrespective
184 of whether it was GDB that planted the breakpoint or the breakpoint
185 is hardcoded in the program. This is required for correct non-stop
189 Indicates the target stopped for a hardware breakpoint. This is
190 required for correct non-stop mode operation.
193 Return information about files on the remote system.
196 Return the full absolute name of the file that was executed to
197 create a process running on the remote system.
200 Select the filesystem on which vFile: operations with filename
201 arguments will operate. This is required for GDB to be able to
202 access files on remote targets where the remote stub does not
203 share a common filesystem with the inferior(s).
206 Indicates that a fork system call was executed.
209 Indicates that a vfork system call was executed.
211 vforkdone stop reason
212 Indicates that a vfork child of the specified process has executed
213 an exec or exit, allowing the vfork parent to resume execution.
215 fork-events and vfork-events features in qSupported
216 The qSupported packet allows GDB to request support for fork and
217 vfork events using new 'gdbfeatures' fork-events and vfork-events,
218 and the qSupported response can contain the corresponding
219 'stubfeatures'. Set and show commands can be used to display
220 whether these features are enabled.
222 * Extended-remote fork events
224 ** GDB now has support for fork events on extended-remote Linux
225 targets. For targets with Linux kernels 2.5.60 and later, this
226 enables follow-fork-mode and detach-on-fork for both fork and
227 vfork, as well as fork and vfork catchpoints.
229 * The info record command now shows the recording format and the
230 branch tracing configuration for the current thread when using
231 the btrace record target.
232 For the BTS format, it shows the ring buffer size.
234 * GDB now has support for DTrace USDT (Userland Static Defined
235 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
237 * GDB now supports access to vector registers on S/390 GNU/Linux
240 * Removed command line options
242 -xdb HP-UX XDB compatibility mode.
244 * Removed targets and native configurations
246 HP/PA running HP-UX hppa*-*-hpux*
247 Itanium running HP-UX ia64-*-hpux*
249 * New configure options
252 This configure option allows the user to build GDB with support for
253 Intel(R) Processor Trace (default: auto). This requires libipt.
255 --with-libipt-prefix=PATH
256 Specify the path to the version of libipt that GDB should use.
257 $PATH/include should contain the intel-pt.h header and
258 $PATH/lib should contain the libipt.so library.
260 *** Changes in GDB 7.9.1
264 ** Xmethods can now specify a result type.
266 *** Changes in GDB 7.9
268 * GDB now supports hardware watchpoints on x86 GNU Hurd.
272 ** You can now access frame registers from Python scripts.
273 ** New attribute 'producer' for gdb.Symtab objects.
274 ** gdb.Objfile objects have a new attribute "progspace",
275 which is the gdb.Progspace object of the containing program space.
276 ** gdb.Objfile objects have a new attribute "owner".
277 ** gdb.Objfile objects have a new attribute "build_id",
278 which is the build ID generated when the file was built.
279 ** gdb.Objfile objects have a new method "add_separate_debug_file".
280 ** A new event "gdb.clear_objfiles" has been added, triggered when
281 selecting a new file to debug.
282 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
283 ** New function gdb.lookup_objfile.
285 New events which are triggered when GDB modifies the state of the
288 ** gdb.events.inferior_call_pre: Function call is about to be made.
289 ** gdb.events.inferior_call_post: Function call has just been made.
290 ** gdb.events.memory_changed: A memory location has been altered.
291 ** gdb.events.register_changed: A register has been altered.
293 * New Python-based convenience functions:
295 ** $_caller_is(name [, number_of_frames])
296 ** $_caller_matches(regexp [, number_of_frames])
297 ** $_any_caller_is(name [, number_of_frames])
298 ** $_any_caller_matches(regexp [, number_of_frames])
300 * GDB now supports the compilation and injection of source code into
301 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
302 to compile the source code to object code, and if successful, inject
303 and execute that code within the current context of the inferior.
304 Currently the C language is supported. The commands used to
305 interface with this new feature are:
307 compile code [-raw|-r] [--] [source code]
308 compile file [-raw|-r] filename
312 demangle [-l language] [--] name
313 Demangle "name" in the specified language, or the current language
314 if elided. This command is renamed from the "maint demangle" command.
315 The latter is kept as a no-op to avoid "maint demangle" being interpreted
316 as "maint demangler-warning".
318 queue-signal signal-name-or-number
319 Queue a signal to be delivered to the thread when it is resumed.
321 add-auto-load-scripts-directory directory
322 Add entries to the list of directories from which to load auto-loaded
325 maint print user-registers
326 List all currently available "user" registers.
328 compile code [-r|-raw] [--] [source code]
329 Compile, inject, and execute in the inferior the executable object
330 code produced by compiling the provided source code.
332 compile file [-r|-raw] filename
333 Compile and inject into the inferior the executable object code
334 produced by compiling the source code stored in the filename
337 * On resume, GDB now always passes the signal the program had stopped
338 for to the thread the signal was sent to, even if the user changed
339 threads before resuming. Previously GDB would often (but not
340 always) deliver the signal to the thread that happens to be current
343 * Conversely, the "signal" command now consistently delivers the
344 requested signal to the current thread. GDB now asks for
345 confirmation if the program had stopped for a signal and the user
346 switched threads meanwhile.
348 * "breakpoint always-inserted" modes "off" and "auto" merged.
350 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
351 won't remove breakpoints from the target until all threads stop,
352 even in non-stop mode. The "auto" mode has been removed, and "off"
353 is now the default mode.
357 set debug symbol-lookup
358 show debug symbol-lookup
359 Control display of debugging info regarding symbol lookup.
363 ** The -list-thread-groups command outputs an exit-code field for
364 inferiors that have exited.
368 MIPS SDE mips*-sde*-elf*
372 Support for these obsolete configurations has been removed.
374 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
375 SGI Irix-5.x mips-*-irix5*
376 SGI Irix-6.x mips-*-irix6*
377 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
378 VAX running Ultrix vax-*-ultrix*
380 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
381 and "assf"), have been removed. Use the "sharedlibrary" command, or
382 its alias "share", instead.
384 *** Changes in GDB 7.8
386 * New command line options
389 This is an alias for the --data-directory option.
391 * GDB supports printing and modifying of variable length automatic arrays
392 as specified in ISO C99.
394 * The ARM simulator now supports instruction level tracing
395 with or without disassembly.
399 GDB now has support for scripting using Guile. Whether this is
400 available is determined at configure time.
401 Guile version 2.0 or greater is required.
402 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
404 * New commands (for set/show, see "New options" below)
408 Invoke CODE by passing it to the Guile interpreter.
412 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
414 info auto-load guile-scripts [regexp]
415 Print the list of automatically loaded Guile scripts.
417 * The source command is now capable of sourcing Guile scripts.
418 This feature is dependent on the debugger being built with Guile support.
422 set print symbol-loading (off|brief|full)
423 show print symbol-loading
424 Control whether to print informational messages when loading symbol
425 information for a file. The default is "full", but when debugging
426 programs with large numbers of shared libraries the amount of output
429 set guile print-stack (none|message|full)
430 show guile print-stack
431 Show a stack trace when an error is encountered in a Guile script.
433 set auto-load guile-scripts (on|off)
434 show auto-load guile-scripts
435 Control auto-loading of Guile script files.
437 maint ada set ignore-descriptive-types (on|off)
438 maint ada show ignore-descriptive-types
439 Control whether the debugger should ignore descriptive types in Ada
440 programs. The default is not to ignore the descriptive types. See
441 the user manual for more details on descriptive types and the intended
442 usage of this option.
444 set auto-connect-native-target
446 Control whether GDB is allowed to automatically connect to the
447 native target for the run, attach, etc. commands when not connected
448 to any target yet. See also "target native" below.
450 set record btrace replay-memory-access (read-only|read-write)
451 show record btrace replay-memory-access
452 Control what memory accesses are allowed during replay.
454 maint set target-async (on|off)
455 maint show target-async
456 This controls whether GDB targets operate in synchronous or
457 asynchronous mode. Normally the default is asynchronous, if it is
458 available; but this can be changed to more easily debug problems
459 occurring only in synchronous mode.
461 set mi-async (on|off)
463 Control whether MI asynchronous mode is preferred. This supersedes
464 "set target-async" of previous GDB versions.
466 * "set target-async" is deprecated as a CLI option and is now an alias
467 for "set mi-async" (only puts MI into async mode).
469 * Background execution commands (e.g., "c&", "s&", etc.) are now
470 possible ``out of the box'' if the target supports them. Previously
471 the user would need to explicitly enable the possibility with the
472 "set target-async on" command.
474 * New features in the GDB remote stub, GDBserver
476 ** New option --debug-format=option1[,option2,...] allows one to add
477 additional text to each output. At present only timestamps
478 are supported: --debug-format=timestamps.
479 Timestamps can also be turned on with the
480 "monitor set debug-format timestamps" command from GDB.
482 * The 'record instruction-history' command now starts counting instructions
483 at one. This also affects the instruction ranges reported by the
484 'record function-call-history' command when given the /i modifier.
486 * The command 'record function-call-history' supports a new modifier '/c' to
487 indent the function names based on their call stack depth.
488 The fields for the '/i' and '/l' modifier have been reordered.
489 The source line range is now prefixed with 'at'.
490 The instruction range is now prefixed with 'inst'.
491 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
492 "record instruction-history" and "list" commands.
494 * The ranges given as arguments to the 'record function-call-history' and
495 'record instruction-history' commands are now inclusive.
497 * The btrace record target now supports the 'record goto' command.
498 For locations inside the execution trace, the back trace is computed
499 based on the information stored in the execution trace.
501 * The btrace record target supports limited reverse execution and replay.
502 The target does not record data and therefore does not allow reading
505 * The "catch syscall" command now works on s390*-linux* targets.
507 * The "compare-sections" command is no longer specific to target
508 remote. It now works with all targets.
510 * All native targets are now consistently called "native".
511 Consequently, the "target child", "target GNU", "target djgpp",
512 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
513 commands have been replaced with "target native". The QNX/NTO port
514 leaves the "procfs" target in place and adds a "native" target for
515 consistency with other ports. The impact on users should be minimal
516 as these commands previously either throwed an error, or were
517 no-ops. The target's name is visible in the output of the following
518 commands: "help target", "info target", "info files", "maint print
521 * The "target native" command now connects to the native target. This
522 can be used to launch native programs even when "set
523 auto-connect-native-target" is set to off.
525 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.
527 * Support for Intel(R) AVX-512 registers on GNU/Linux.
528 Support displaying and modifying Intel(R) AVX-512 registers
529 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
533 qXfer:btrace:read's annex
534 The qXfer:btrace:read packet supports a new annex 'delta' to read
535 branch trace incrementally.
539 ** Valid Python operations on gdb.Value objects representing
540 structs/classes invoke the corresponding overloaded operators if
542 ** New `Xmethods' feature in the Python API. Xmethods are
543 additional methods or replacements for existing methods of a C++
544 class. This feature is useful for those cases where a method
545 defined in C++ source code could be inlined or optimized out by
546 the compiler, making it unavailable to GDB.
549 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
551 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
552 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
553 its alias "share", instead.
555 * The commands "set remotebaud" and "show remotebaud" are no longer
556 supported. Use "set serial baud" and "show serial baud" (respectively)
561 ** A new option "-gdb-set mi-async" replaces "-gdb-set
562 target-async". The latter is left as a deprecated alias of the
563 former for backward compatibility. If the target supports it,
564 CLI background execution commands are now always possible by
565 default, independently of whether the frontend stated a
566 preference for asynchronous execution with "-gdb-set mi-async".
567 Previously "-gdb-set target-async off" affected both MI execution
568 commands and CLI execution commands.
570 *** Changes in GDB 7.7
572 * Improved support for process record-replay and reverse debugging on
573 arm*-linux* targets. Support for thumb32 and syscall instruction
574 recording has been added.
576 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
578 * GDB now supports Fission DWP file format version 2.
579 http://gcc.gnu.org/wiki/DebugFission
581 * New convenience function "$_isvoid", to check whether an expression
582 is void. A void expression is an expression where the type of the
583 result is "void". For example, some convenience variables may be
584 "void" when evaluated (e.g., "$_exitcode" before the execution of
585 the program being debugged; or an undefined convenience variable).
586 Another example, when calling a function whose return type is
589 * The "maintenance print objfiles" command now takes an optional regexp.
591 * The "catch syscall" command now works on arm*-linux* targets.
593 * GDB now consistently shows "<not saved>" when printing values of
594 registers the debug info indicates have not been saved in the frame
595 and there's nowhere to retrieve them from
596 (callee-saved/call-clobbered registers):
601 (gdb) info registers rax
604 Before, the former would print "<optimized out>", and the latter
605 "*value not available*".
607 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
612 ** Frame filters and frame decorators have been added.
613 ** Temporary breakpoints are now supported.
614 ** Line tables representation has been added.
615 ** New attribute 'parent_type' for gdb.Field objects.
616 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
617 ** New attribute 'name' for gdb.Type objects.
621 Nios II ELF nios2*-*-elf
622 Nios II GNU/Linux nios2*-*-linux
623 Texas Instruments MSP430 msp430*-*-elf
625 * Removed native configurations
627 Support for these a.out NetBSD and OpenBSD obsolete configurations has
628 been removed. ELF variants of these configurations are kept supported.
630 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
631 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
632 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
633 i[34567]86-*-openbsd3.[0-3]
634 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
635 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
636 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
640 Like "catch throw", but catches a re-thrown exception.
642 Renamed from old "maint check-symtabs".
644 Perform consistency checks on symtabs.
646 Expand symtabs matching an optional regexp.
649 Display the details of GDB configure-time options.
651 maint set|show per-command
652 maint set|show per-command space
653 maint set|show per-command time
654 maint set|show per-command symtab
655 Enable display of per-command gdb resource usage.
657 remove-symbol-file FILENAME
658 remove-symbol-file -a ADDRESS
659 Remove a symbol file added via add-symbol-file. The file to remove
660 can be identified by its filename or by an address that lies within
661 the boundaries of this symbol file in memory.
664 info exceptions REGEXP
665 Display the list of Ada exceptions defined in the program being
666 debugged. If provided, only the exceptions whose names match REGEXP
671 set debug symfile off|on
673 Control display of debugging info regarding reading symbol files and
674 symbol tables within those files
676 set print raw frame-arguments
677 show print raw frame-arguments
678 Set/show whether to print frame arguments in raw mode,
679 disregarding any defined pretty-printers.
681 set remote trace-status-packet
682 show remote trace-status-packet
683 Set/show the use of remote protocol qTStatus packet.
687 Control display of debugging messages related to Nios II targets.
691 Control whether target-assisted range stepping is enabled.
693 set startup-with-shell
694 show startup-with-shell
695 Specifies whether Unix child processes are started via a shell or
700 Use the target memory cache for accesses to the code segment. This
701 improves performance of remote debugging (particularly disassembly).
703 * You can now use a literal value 'unlimited' for options that
704 interpret 0 or -1 as meaning "unlimited". E.g., "set
705 trace-buffer-size unlimited" is now an alias for "set
706 trace-buffer-size -1" and "set height unlimited" is now an alias for
709 * The "set debug symtab-create" debugging option of GDB has been changed to
710 accept a verbosity level. 0 means "off", 1 provides basic debugging
711 output, and values of 2 or greater provides more verbose output.
713 * New command-line options
715 Display the details of GDB configure-time options.
717 * The command 'tsave' can now support new option '-ctf' to save trace
718 buffer in Common Trace Format.
720 * Newly installed $prefix/bin/gcore acts as a shell interface for the
723 * GDB now implements the the C++ 'typeid' operator.
725 * The new convenience variable $_exception holds the exception being
726 thrown or caught at an exception-related catchpoint.
728 * The exception-related catchpoints, like "catch throw", now accept a
729 regular expression which can be used to filter exceptions by type.
731 * The new convenience variable $_exitsignal is automatically set to
732 the terminating signal number when the program being debugged dies
733 due to an uncaught signal.
737 ** All MI commands now accept an optional "--language" option.
738 Support for this feature can be verified by using the "-list-features"
739 command, which should contain "language-option".
741 ** The new command -info-gdb-mi-command allows the user to determine
742 whether a GDB/MI command is supported or not.
744 ** The "^error" result record returned when trying to execute an undefined
745 GDB/MI command now provides a variable named "code" whose content is the
746 "undefined-command" error code. Support for this feature can be verified
747 by using the "-list-features" command, which should contain
748 "undefined-command-error-code".
750 ** The -trace-save MI command can optionally save trace buffer in Common
753 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
755 ** The command -data-list-register-values now accepts an optional
756 "--skip-unavailable" option. When used, only the available registers
759 ** The new command -trace-frame-collected dumps collected variables,
760 computed expressions, tvars, memory and registers in a traceframe.
762 ** The commands -stack-list-locals, -stack-list-arguments and
763 -stack-list-variables now accept an option "--skip-unavailable".
764 When used, only the available locals or arguments are displayed.
766 ** The -exec-run command now accepts an optional "--start" option.
767 When used, the command follows the same semantics as the "start"
768 command, stopping the program's execution at the start of its
769 main subprogram. Support for this feature can be verified using
770 the "-list-features" command, which should contain
771 "exec-run-start-option".
773 ** The new commands -catch-assert and -catch-exceptions insert
774 catchpoints stopping the program when Ada exceptions are raised.
776 ** The new command -info-ada-exceptions provides the equivalent of
777 the new "info exceptions" command.
779 * New system-wide configuration scripts
780 A GDB installation now provides scripts suitable for use as system-wide
781 configuration scripts for the following systems:
785 * GDB now supports target-assigned range stepping with remote targets.
786 This improves the performance of stepping source lines by reducing
787 the number of control packets from/to GDB. See "New remote packets"
790 * GDB now understands the element 'tvar' in the XML traceframe info.
791 It has the id of the collected trace state variables.
793 * On S/390 targets that provide the transactional-execution feature,
794 the program interruption transaction diagnostic block (TDB) is now
795 represented as a number of additional "registers" in GDB.
801 The vCont packet supports a new 'r' action, that tells the remote
802 stub to step through an address range itself, without GDB
803 involvemement at each single-step.
805 qXfer:libraries-svr4:read's annex
806 The previously unused annex of the qXfer:libraries-svr4:read packet
807 is now used to support passing an argument list. The remote stub
808 reports support for this argument list to GDB's qSupported query.
809 The defined arguments are "start" and "prev", used to reduce work
810 necessary for library list updating, resulting in significant
813 * New features in the GDB remote stub, GDBserver
815 ** GDBserver now supports target-assisted range stepping. Currently
816 enabled on x86/x86_64 GNU/Linux targets.
818 ** GDBserver now adds element 'tvar' in the XML in the reply to
819 'qXfer:traceframe-info:read'. It has the id of the collected
820 trace state variables.
822 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
825 * New 'z' formatter for printing and examining memory, this displays the
826 value as hexadecimal zero padded on the left to the size of the type.
828 * GDB can now use Windows x64 unwinding data.
830 * The "set remotebaud" command has been replaced by "set serial baud".
831 Similarly, "show remotebaud" has been replaced by "show serial baud".
832 The "set remotebaud" and "show remotebaud" commands are still available
833 to provide backward compatibility with older versions of GDB.
835 *** Changes in GDB 7.6
837 * Target record has been renamed to record-full.
838 Record/replay is now enabled with the "record full" command.
839 This also affects settings that are associated with full record/replay
840 that have been moved from "set/show record" to "set/show record full":
842 set|show record full insn-number-max
843 set|show record full stop-at-limit
844 set|show record full memory-query
846 * A new record target "record-btrace" has been added. The new target
847 uses hardware support to record the control-flow of a process. It
848 does not support replaying the execution, but it implements the
849 below new commands for investigating the recorded execution log.
850 This new recording method can be enabled using:
854 The "record-btrace" target is only available on Intel Atom processors
855 and requires a Linux kernel 2.6.32 or later.
857 * Two new commands have been added for record/replay to give information
858 about the recorded execution without having to replay the execution.
859 The commands are only supported by "record btrace".
861 record instruction-history prints the execution history at
862 instruction granularity
864 record function-call-history prints the execution history at
867 * New native configurations
869 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
870 FreeBSD/powerpc powerpc*-*-freebsd
871 x86_64/Cygwin x86_64-*-cygwin*
872 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
876 ARM AArch64 aarch64*-*-elf
877 ARM AArch64 GNU/Linux aarch64*-*-linux
878 Lynx 178 PowerPC powerpc-*-lynx*178
879 x86_64/Cygwin x86_64-*-cygwin*
880 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
882 * If the configured location of system.gdbinit file (as given by the
883 --with-system-gdbinit option at configure time) is in the
884 data-directory (as specified by --with-gdb-datadir at configure
885 time) or in one of its subdirectories, then GDB will look for the
886 system-wide init file in the directory specified by the
887 --data-directory command-line option.
889 * New command line options:
891 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
892 other initialization files, unlike -nx which disables all of them.
894 * Removed command line options
896 -epoch This was used by the gdb mode in Epoch, an ancient fork of
899 * The 'ptype' and 'whatis' commands now accept an argument to control
902 * 'info proc' now works on some core files.
906 ** Vectors can be created with gdb.Type.vector.
908 ** Python's atexit.register now works in GDB.
910 ** Types can be pretty-printed via a Python API.
912 ** Python 3 is now supported (in addition to Python 2.4 or later)
914 ** New class gdb.Architecture exposes GDB's internal representation
915 of architecture in the Python API.
917 ** New method Frame.architecture returns the gdb.Architecture object
918 corresponding to the frame's architecture.
920 * New Python-based convenience functions:
922 ** $_memeq(buf1, buf2, length)
923 ** $_streq(str1, str2)
925 ** $_regex(str, regex)
927 * The 'cd' command now defaults to using '~' (the home directory) if not
930 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
931 default for GCC since November 2000.
933 * The command 'forward-search' can now be abbreviated as 'fo'.
935 * The command 'info tracepoints' can now display 'installed on target'
936 or 'not installed on target' for each non-pending location of tracepoint.
938 * New configure options
940 --enable-libmcheck/--disable-libmcheck
941 By default, development versions are built with -lmcheck on hosts
942 that support it, in order to help track memory corruption issues.
943 Release versions, on the other hand, are built without -lmcheck
944 by default. The --enable-libmcheck/--disable-libmcheck configure
945 options allow the user to override that default.
946 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
947 This configure option allows the user to build GDB with
948 libbabeltrace using which GDB can read Common Trace Format data.
950 * New commands (for set/show, see "New options" below)
953 Catch signals. This is similar to "handle", but allows commands and
954 conditions to be attached.
957 List the BFDs known to GDB.
959 python-interactive [command]
961 Start a Python interactive prompt, or evaluate the optional command
962 and print the result of expressions.
965 "py" is a new alias for "python".
967 enable type-printer [name]...
968 disable type-printer [name]...
969 Enable or disable type printers.
973 ** For the Renesas Super-H architecture, the "regs" command has been removed
974 (has been deprecated in GDB 7.5), and "info all-registers" should be used
979 set print type methods (on|off)
980 show print type methods
981 Control whether method declarations are displayed by "ptype".
982 The default is to show them.
984 set print type typedefs (on|off)
985 show print type typedefs
986 Control whether typedef definitions are displayed by "ptype".
987 The default is to show them.
989 set filename-display basename|relative|absolute
990 show filename-display
991 Control the way in which filenames is displayed.
992 The default is "relative", which preserves previous behavior.
994 set trace-buffer-size
995 show trace-buffer-size
996 Request target to change the size of trace buffer.
998 set remote trace-buffer-size-packet auto|on|off
999 show remote trace-buffer-size-packet
1000 Control the use of the remote protocol `QTBuffer:size' packet.
1004 Control display of debugging messages related to ARM AArch64.
1007 set debug coff-pe-read
1008 show debug coff-pe-read
1009 Control display of debugging messages related to reading of COFF/PE
1014 Control display of debugging messages related to Mach-O symbols
1017 set debug notification
1018 show debug notification
1019 Control display of debugging info for async remote notification.
1023 ** Command parameter changes are now notified using new async record
1024 "=cmd-param-changed".
1025 ** Trace frame changes caused by command "tfind" are now notified using
1026 new async record "=traceframe-changed".
1027 ** The creation, deletion and modification of trace state variables
1028 are now notified using new async records "=tsv-created",
1029 "=tsv-deleted" and "=tsv-modified".
1030 ** The start and stop of process record are now notified using new
1031 async record "=record-started" and "=record-stopped".
1032 ** Memory changes are now notified using new async record
1034 ** The data-disassemble command response will include a "fullname" field
1035 containing the absolute file name when source has been requested.
1036 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1037 command, to allow pattern filling of memory areas.
1038 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1039 library load/unload events.
1040 ** The response to breakpoint commands and breakpoint async records
1041 includes an "installed" field containing a boolean state about each
1042 non-pending tracepoint location is whether installed on target or not.
1043 ** Output of the "-trace-status" command includes a "trace-file" field
1044 containing the name of the trace file being examined. This field is
1045 optional, and only present when examining a trace file.
1046 ** The "fullname" field is now always present along with the "file" field,
1047 even if the file cannot be found by GDB.
1049 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1050 You must have the LZMA library available when configuring GDB for this
1051 feature to be enabled. For more information, see:
1052 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1054 * New remote packets
1057 Set the size of trace buffer. The remote stub reports support for this
1058 packet to gdb's qSupported query.
1061 Enable Branch Trace Store (BTS)-based branch tracing for the current
1062 thread. The remote stub reports support for this packet to gdb's
1066 Disable branch tracing for the current thread. The remote stub reports
1067 support for this packet to gdb's qSupported query.
1070 Read the traced branches for the current thread. The remote stub
1071 reports support for this packet to gdb's qSupported query.
1073 *** Changes in GDB 7.5
1075 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1076 for more x32 ABI info.
1078 * GDB now supports access to MIPS DSP registers on Linux targets.
1080 * GDB now supports debugging microMIPS binaries.
1082 * The "info os" command on GNU/Linux can now display information on
1083 several new classes of objects managed by the operating system:
1084 "info os procgroups" lists process groups
1085 "info os files" lists file descriptors
1086 "info os sockets" lists internet-domain sockets
1087 "info os shm" lists shared-memory regions
1088 "info os semaphores" lists semaphores
1089 "info os msg" lists message queues
1090 "info os modules" lists loaded kernel modules
1092 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1093 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1094 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1095 options and inspect the probe arguments using the new $_probe_arg family
1096 of convenience variables. You can obtain more information about SystemTap
1097 in <http://sourceware.org/systemtap/>.
1099 * GDB now supports reversible debugging on ARM, it allows you to
1100 debug basic ARM and THUMB instructions, and provides
1101 record/replay support.
1103 * The option "symbol-reloading" has been deleted as it is no longer used.
1107 ** GDB commands implemented in Python can now be put in command class
1110 ** The "maint set python print-stack on|off" is now deleted.
1112 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1113 apply "flag enum"-style pretty-printing to any enum.
1115 ** gdb.lookup_symbol can now work when there is no current frame.
1117 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1118 the source at which the symbol was defined.
1120 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1121 method 'value'. The former indicates whether the symbol needs a
1122 frame in order to compute its value, and the latter computes the
1125 ** A new method 'referenced_value' on gdb.Value objects which can
1126 dereference pointer as well as C++ reference values.
1128 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1129 which return the global and static blocks (as gdb.Block objects),
1130 of the underlying symbol table, respectively.
1132 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1133 object associated with a PC value.
1135 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1136 of the address range occupied by code for the current source line.
1138 * Go language support.
1139 GDB now supports debugging programs written in the Go programming
1142 * GDBserver now supports stdio connections.
1143 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1145 * The binary "gdbtui" can no longer be built or installed.
1146 Use "gdb -tui" instead.
1148 * GDB will now print "flag" enums specially. A flag enum is one where
1149 all the enumerator values have no bits in common when pairwise
1150 "and"ed. When printing a value whose type is a flag enum, GDB will
1151 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1152 (gdb) print (enum E) 3
1155 * The filename part of a linespec will now match trailing components
1156 of a source file name. For example, "break gcc/expr.c:1000" will
1157 now set a breakpoint in build/gcc/expr.c, but not
1158 build/libcpp/expr.c.
1160 * The "info proc" and "generate-core-file" commands will now also
1161 work on remote targets connected to GDBserver on Linux.
1163 * The command "info catch" has been removed. It has been disabled
1164 since December 2007.
1166 * The "catch exception" and "catch assert" commands now accept
1167 a condition at the end of the command, much like the "break"
1168 command does. For instance:
1170 (gdb) catch exception Constraint_Error if Barrier = True
1172 Previously, it was possible to add a condition to such catchpoints,
1173 but it had to be done as a second step, after the catchpoint had been
1174 created, using the "condition" command.
1176 * The "info static-tracepoint-marker" command will now also work on
1177 native Linux targets with in-process agent.
1179 * GDB can now set breakpoints on inlined functions.
1181 * The .gdb_index section has been updated to include symbols for
1182 inlined functions. GDB will ignore older .gdb_index sections by
1183 default, which could cause symbol files to be loaded more slowly
1184 until their .gdb_index sections can be recreated. The new command
1185 "set use-deprecated-index-sections on" will cause GDB to use any older
1186 .gdb_index sections it finds. This will restore performance, but the
1187 ability to set breakpoints on inlined functions will be lost in symbol
1188 files with older .gdb_index sections.
1190 The .gdb_index section has also been updated to record more information
1191 about each symbol. This speeds up the "info variables", "info functions"
1192 and "info types" commands when used with programs having the .gdb_index
1193 section, as well as speeding up debugging with shared libraries using
1194 the .gdb_index section.
1196 * Ada support for GDB/MI Variable Objects has been added.
1198 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1203 ** New command -info-os is the MI equivalent of "info os".
1205 ** Output logs ("set logging" and related) now include MI output.
1209 ** "set use-deprecated-index-sections on|off"
1210 "show use-deprecated-index-sections on|off"
1211 Controls the use of deprecated .gdb_index sections.
1213 ** "catch load" and "catch unload" can be used to stop when a shared
1214 library is loaded or unloaded, respectively.
1216 ** "enable count" can be used to auto-disable a breakpoint after
1219 ** "info vtbl" can be used to show the virtual method tables for
1220 C++ and Java objects.
1222 ** "explore" and its sub commands "explore value" and "explore type"
1223 can be used to recursively explore values and types of
1224 expressions. These commands are available only if GDB is
1225 configured with '--with-python'.
1227 ** "info auto-load" shows status of all kinds of auto-loaded files,
1228 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1229 sequences of commands files, "info auto-load python-scripts"
1230 shows status of auto-loading Python script files,
1231 "info auto-load local-gdbinit" shows status of loading init file
1232 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1233 status of inferior specific thread debugging shared library loading.
1235 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1236 and "show auto-load-scripts" commands have been deprecated, use their
1237 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1238 and "show auto-load python-scripts" counterparts instead.
1240 ** "dprintf location,format,args..." creates a dynamic printf, which
1241 is basically a breakpoint that does a printf and immediately
1242 resumes your program's execution, so it is like a printf that you
1243 can insert dynamically at runtime instead of at compiletime.
1245 ** "set print symbol"
1247 Controls whether GDB attempts to display the symbol, if any,
1248 corresponding to addresses it prints. This defaults to "on", but
1249 you can set it to "off" to restore GDB's previous behavior.
1251 * Deprecated commands
1253 ** For the Renesas Super-H architecture, the "regs" command has been
1254 deprecated, and "info all-registers" should be used instead.
1258 Renesas RL78 rl78-*-elf
1259 HP OpenVMS ia64 ia64-hp-openvms*
1261 * GDBserver supports evaluation of breakpoint conditions. When
1262 support is advertised by GDBserver, GDB may be told to send the
1263 breakpoint conditions in bytecode form to GDBserver. GDBserver
1264 will only report the breakpoint trigger to GDB when its condition
1269 set mips compression
1270 show mips compression
1271 Select the compressed ISA encoding used in functions that have no symbol
1272 information available. The encoding can be set to either of:
1275 and is updated automatically from ELF file flags if available.
1277 set breakpoint condition-evaluation
1278 show breakpoint condition-evaluation
1279 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1280 GDBserver ("target"). Default option "auto" chooses the most efficient
1282 This option can improve debugger efficiency depending on the speed of the
1286 Disable auto-loading globally.
1289 Show auto-loading setting of all kinds of auto-loaded files.
1291 set auto-load gdb-scripts on|off
1292 show auto-load gdb-scripts
1293 Control auto-loading of GDB canned sequences of commands files.
1295 set auto-load python-scripts on|off
1296 show auto-load python-scripts
1297 Control auto-loading of Python script files.
1299 set auto-load local-gdbinit on|off
1300 show auto-load local-gdbinit
1301 Control loading of init file (.gdbinit) from current directory.
1303 set auto-load libthread-db on|off
1304 show auto-load libthread-db
1305 Control auto-loading of inferior specific thread debugging shared library.
1307 set auto-load scripts-directory <dir1>[:<dir2>...]
1308 show auto-load scripts-directory
1309 Set a list of directories from which to load auto-loaded scripts.
1310 Automatically loaded Python scripts and GDB scripts are located in one
1311 of the directories listed by this option.
1312 The delimiter (':' above) may differ according to the host platform.
1314 set auto-load safe-path <dir1>[:<dir2>...]
1315 show auto-load safe-path
1316 Set a list of directories from which it is safe to auto-load files.
1317 The delimiter (':' above) may differ according to the host platform.
1319 set debug auto-load on|off
1320 show debug auto-load
1321 Control display of debugging info for auto-loading the files above.
1323 set dprintf-style gdb|call|agent
1325 Control the way in which a dynamic printf is performed; "gdb"
1326 requests a GDB printf command, while "call" causes dprintf to call a
1327 function in the inferior. "agent" requests that the target agent
1328 (such as GDBserver) do the printing.
1330 set dprintf-function <expr>
1331 show dprintf-function
1332 set dprintf-channel <expr>
1333 show dprintf-channel
1334 Set the function and optional first argument to the call when using
1335 the "call" style of dynamic printf.
1337 set disconnected-dprintf on|off
1338 show disconnected-dprintf
1339 Control whether agent-style dynamic printfs continue to be in effect
1340 after GDB disconnects.
1342 * New configure options
1344 --with-auto-load-dir
1345 Configure default value for the 'set auto-load scripts-directory'
1346 setting above. It defaults to '$debugdir:$datadir/auto-load',
1347 $debugdir representing global debugging info directories (available
1348 via 'show debug-file-directory') and $datadir representing GDB's data
1349 directory (available via 'show data-directory').
1351 --with-auto-load-safe-path
1352 Configure default value for the 'set auto-load safe-path' setting
1353 above. It defaults to the --with-auto-load-dir setting.
1355 --without-auto-load-safe-path
1356 Set 'set auto-load safe-path' to '/', effectively disabling this
1359 * New remote packets
1361 z0/z1 conditional breakpoints extension
1363 The z0/z1 breakpoint insertion packets have been extended to carry
1364 a list of conditional expressions over to the remote stub depending on the
1365 condition evaluation mode. The use of this extension can be controlled
1366 via the "set remote conditional-breakpoints-packet" command.
1370 Specify the signals which the remote stub may pass to the debugged
1371 program without GDB involvement.
1373 * New command line options
1375 --init-command=FILE, -ix Like --command, -x but execute it
1376 before loading inferior.
1377 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1378 execute it before loading inferior.
1380 *** Changes in GDB 7.4
1382 * GDB now handles ambiguous linespecs more consistently; the existing
1383 FILE:LINE support has been expanded to other types of linespecs. A
1384 breakpoint will now be set on all matching locations in all
1385 inferiors, and locations will be added or removed according to
1388 * GDB now allows you to skip uninteresting functions and files when
1389 stepping with the "skip function" and "skip file" commands.
1391 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1392 and "show remote hardware-watchpoint-length-limit". These allows to
1393 set or show the maximum length limit (in bytes) of a remote
1394 target hardware watchpoint.
1396 This allows e.g. to use "unlimited" hardware watchpoints with the
1397 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1398 watchpoints are slower than real hardware watchpoints but are
1399 significantly faster than gdb software watchpoints.
1403 ** The register_pretty_printer function in module gdb.printing now takes
1404 an optional `replace' argument. If True, the new printer replaces any
1407 ** The "maint set python print-stack on|off" command has been
1408 deprecated and will be deleted in GDB 7.5.
1409 A new command: "set python print-stack none|full|message" has
1410 replaced it. Additionally, the default for "print-stack" is
1411 now "message", which just prints the error message without
1414 ** A prompt substitution hook (prompt_hook) is now available to the
1417 ** A new Python module, gdb.prompt has been added to the GDB Python
1418 modules library. This module provides functionality for
1419 escape sequences in prompts (used by set/show
1420 extended-prompt). These escape sequences are replaced by their
1421 corresponding value.
1423 ** Python commands and convenience-functions located in
1424 'data-directory'/python/gdb/command and
1425 'data-directory'/python/gdb/function are now automatically loaded
1428 ** Blocks now provide four new attributes. global_block and
1429 static_block will return the global and static blocks
1430 respectively. is_static and is_global are boolean attributes
1431 that indicate if the block is one of those two types.
1433 ** Symbols now provide the "type" attribute, the type of the symbol.
1435 ** The "gdb.breakpoint" function has been deprecated in favor of
1438 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1439 of a function. This class is based on the "finish" command
1440 available in the CLI.
1442 ** Type objects for struct and union types now allow access to
1443 the fields using standard Python dictionary (mapping) methods.
1444 For example, "some_type['myfield']" now works, as does
1445 "some_type.items()".
1447 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1450 ** A new function, "deep_items" has been added to the gdb.types
1451 module in the GDB Python modules library. This function returns
1452 an iterator over the fields of a struct or union type. Unlike
1453 the standard Python "iteritems" method, it will recursively traverse
1454 any anonymous fields.
1458 ** "*stopped" events can report several new "reason"s, such as
1461 ** Breakpoint changes are now notified using new async records, like
1462 "=breakpoint-modified".
1464 ** New command -ada-task-info.
1466 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1467 $sdir specifies the default system locations of shared libraries.
1468 $pdir specifies the directory where the libpthread used by the application
1471 GDB no longer looks in $sdir and $pdir after it has searched the directories
1472 mentioned in libthread-db-search-path. If you want to search those
1473 directories, they must be specified in libthread-db-search-path.
1474 The default value of libthread-db-search-path on GNU/Linux and Solaris
1475 systems is now "$sdir:$pdir".
1477 $pdir is not supported by gdbserver, it is currently ignored.
1478 $sdir is supported by gdbserver.
1480 * New configure option --with-iconv-bin.
1481 When using the internationalization support like the one in the GNU C
1482 library, GDB will invoke the "iconv" program to get a list of supported
1483 character sets. If this program lives in a non-standard location, one can
1484 use this option to specify where to find it.
1486 * When natively debugging programs on PowerPC BookE processors running
1487 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1488 watchpoints, which specify a mask in addition to an address to watch.
1489 The mask specifies that some bits of an address (the bits which are
1490 reset in the mask) should be ignored when matching the address accessed
1491 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1492 section in the user manual for more details.
1494 * The new option --once causes GDBserver to stop listening for connections once
1495 the first connection is made. The listening port used by GDBserver will
1496 become available after that.
1498 * New commands "info macros" and "alias" have been added.
1500 * New function parameters suffix @entry specifies value of function parameter
1501 at the time the function got called. Entry values are available only since
1507 "!" is now an alias of the "shell" command.
1508 Note that no space is needed between "!" and SHELL COMMAND.
1512 watch EXPRESSION mask MASK_VALUE
1513 The watch command now supports the mask argument which allows creation
1514 of masked watchpoints, if the current architecture supports this feature.
1516 info auto-load-scripts [REGEXP]
1517 This command was formerly named "maintenance print section-scripts".
1518 It is now generally useful and is no longer a maintenance-only command.
1520 info macro [-all] [--] MACRO
1521 The info macro command has new options `-all' and `--'. The first for
1522 printing all definitions of a macro. The second for explicitly specifying
1523 the end of arguments and the beginning of the macro name in case the macro
1524 name starts with a hyphen.
1526 collect[/s] EXPRESSIONS
1527 The tracepoint collect command now takes an optional modifier "/s"
1528 that directs it to dereference pointer-to-character types and
1529 collect the bytes of memory up to a zero byte. The behavior is
1530 similar to what you see when you use the regular print command on a
1531 string. An optional integer following the "/s" sets a bound on the
1532 number of bytes that will be collected.
1535 The trace start command now interprets any supplied arguments as a
1536 note to be recorded with the trace run, with an effect similar to
1537 setting the variable trace-notes.
1540 The trace stop command now interprets any arguments as a note to be
1541 mentioned along with the tstatus report that the trace was stopped
1542 with a command. The effect is similar to setting the variable
1545 * Tracepoints can now be enabled and disabled at any time after a trace
1546 experiment has been started using the standard "enable" and "disable"
1547 commands. It is now possible to start a trace experiment with no enabled
1548 tracepoints; GDB will display a warning, but will allow the experiment to
1549 begin, assuming that tracepoints will be enabled as needed while the trace
1552 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1553 locations with 4-byte instructions, when they were previously
1554 limited to locations with instructions of 5 bytes or longer.
1558 set debug dwarf2-read
1559 show debug dwarf2-read
1560 Turns on or off display of debugging messages related to reading
1561 DWARF debug info. The default is off.
1563 set debug symtab-create
1564 show debug symtab-create
1565 Turns on or off display of debugging messages related to symbol table
1566 creation. The default is off.
1569 show extended-prompt
1570 Set the GDB prompt, and allow escape sequences to be inserted to
1571 display miscellaneous information (see 'help set extended-prompt'
1572 for the list of sequences). This prompt (and any information
1573 accessed through the escape sequences) is updated every time the
1574 prompt is displayed.
1576 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1577 show print entry-values
1578 Set printing of frame argument values at function entry. In some cases
1579 GDB can determine the value of function argument which was passed by the
1580 function caller, even if the value was modified inside the called function.
1582 set debug entry-values
1583 show debug entry-values
1584 Control display of debugging info for determining frame argument values at
1585 function entry and virtual tail call frames.
1587 set basenames-may-differ
1588 show basenames-may-differ
1589 Set whether a source file may have multiple base names.
1590 (A "base name" is the name of a file with the directory part removed.
1591 Example: The base name of "/home/user/hello.c" is "hello.c".)
1592 If set, GDB will canonicalize file names (e.g., expand symlinks)
1593 before comparing them. Canonicalization is an expensive operation,
1594 but it allows the same file be known by more than one base name.
1595 If not set (the default), all source files are assumed to have just
1596 one base name, and gdb will do file name comparisons more efficiently.
1602 Set a user name and notes for the current and any future trace runs.
1603 This is useful for long-running and/or disconnected traces, to
1604 inform others (or yourself) as to who is running the trace, supply
1605 contact information, or otherwise explain what is going on.
1607 set trace-stop-notes
1608 show trace-stop-notes
1609 Set a note attached to the trace run, that is displayed when the
1610 trace has been stopped by a tstop command. This is useful for
1611 instance as an explanation, if you are stopping a trace run that was
1612 started by someone else.
1614 * New remote packets
1618 Dynamically enable a tracepoint in a started trace experiment.
1622 Dynamically disable a tracepoint in a started trace experiment.
1626 Set the user and notes of the trace run.
1630 Query the current status of a tracepoint.
1634 Query the minimum length of instruction at which a fast tracepoint may
1637 * Dcache size (number of lines) and line-size are now runtime-configurable
1638 via "set dcache line" and "set dcache line-size" commands.
1642 Texas Instruments TMS320C6x tic6x-*-*
1646 Renesas RL78 rl78-*-elf
1648 *** Changes in GDB 7.3.1
1650 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1652 *** Changes in GDB 7.3
1654 * GDB has a new command: "thread find [REGEXP]".
1655 It finds the thread id whose name, target id, or thread extra info
1656 matches the given regular expression.
1658 * The "catch syscall" command now works on mips*-linux* targets.
1660 * The -data-disassemble MI command now supports modes 2 and 3 for
1661 dumping the instruction opcodes.
1663 * New command line options
1665 -data-directory DIR Specify DIR as the "data-directory".
1666 This is mostly for testing purposes.
1668 * The "maint set python auto-load on|off" command has been renamed to
1669 "set auto-load-scripts on|off".
1671 * GDB has a new command: "set directories".
1672 It is like the "dir" command except that it replaces the
1673 source path list instead of augmenting it.
1675 * GDB now understands thread names.
1677 On GNU/Linux, "info threads" will display the thread name as set by
1678 prctl or pthread_setname_np.
1680 There is also a new command, "thread name", which can be used to
1681 assign a name internally for GDB to display.
1684 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1685 has been integrated into GDB.
1689 ** The function gdb.Write now accepts an optional keyword 'stream'.
1690 This keyword, when provided, will direct the output to either
1691 stdout, stderr, or GDB's logging output.
1693 ** Parameters can now be be sub-classed in Python, and in particular
1694 you may implement the get_set_doc and get_show_doc functions.
1695 This improves how Parameter set/show documentation is processed
1696 and allows for more dynamic content.
1698 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1699 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1700 have an is_valid method.
1702 ** Breakpoints can now be sub-classed in Python, and in particular
1703 you may implement a 'stop' function that is executed each time
1704 the inferior reaches that breakpoint.
1706 ** New function gdb.lookup_global_symbol looks up a global symbol.
1708 ** GDB values in Python are now callable if the value represents a
1709 function. For example, if 'some_value' represents a function that
1710 takes two integer parameters and returns a value, you can call
1711 that function like so:
1713 result = some_value (10,20)
1715 ** Module gdb.types has been added.
1716 It contains a collection of utilities for working with gdb.Types objects:
1717 get_basic_type, has_field, make_enum_dict.
1719 ** Module gdb.printing has been added.
1720 It contains utilities for writing and registering pretty-printers.
1721 New classes: PrettyPrinter, SubPrettyPrinter,
1722 RegexpCollectionPrettyPrinter.
1723 New function: register_pretty_printer.
1725 ** New commands "info pretty-printers", "enable pretty-printer" and
1726 "disable pretty-printer" have been added.
1728 ** gdb.parameter("directories") is now available.
1730 ** New function gdb.newest_frame returns the newest frame in the
1733 ** The gdb.InferiorThread class has a new "name" attribute. This
1734 holds the thread's name.
1736 ** Python Support for Inferior events.
1737 Python scripts can add observers to be notified of events
1738 occurring in the process being debugged.
1739 The following events are currently supported:
1740 - gdb.events.cont Continue event.
1741 - gdb.events.exited Inferior exited event.
1742 - gdb.events.stop Signal received, and Breakpoint hit events.
1746 ** GDB now puts template parameters in scope when debugging in an
1747 instantiation. For example, if you have:
1749 template<int X> int func (void) { return X; }
1751 then if you step into func<5>, "print X" will show "5". This
1752 feature requires proper debuginfo support from the compiler; it
1753 was added to GCC 4.5.
1755 ** The motion commands "next", "finish", "until", and "advance" now
1756 work better when exceptions are thrown. In particular, GDB will
1757 no longer lose control of the inferior; instead, the GDB will
1758 stop the inferior at the point at which the exception is caught.
1759 This functionality requires a change in the exception handling
1760 code that was introduced in GCC 4.5.
1762 * GDB now follows GCC's rules on accessing volatile objects when
1763 reading or writing target state during expression evaluation.
1764 One notable difference to prior behavior is that "print x = 0"
1765 no longer generates a read of x; the value of the assignment is
1766 now always taken directly from the value being assigned.
1768 * GDB now has some support for using labels in the program's source in
1769 linespecs. For instance, you can use "advance label" to continue
1770 execution to a label.
1772 * GDB now has support for reading and writing a new .gdb_index
1773 section. This section holds a fast index of DWARF debugging
1774 information and can be used to greatly speed up GDB startup and
1775 operation. See the documentation for `save gdb-index' for details.
1777 * The "watch" command now accepts an optional "-location" argument.
1778 When used, this causes GDB to watch the memory referred to by the
1779 expression. Such a watchpoint is never deleted due to it going out
1782 * GDB now supports thread debugging of core dumps on GNU/Linux.
1784 GDB now activates thread debugging using the libthread_db library
1785 when debugging GNU/Linux core dumps, similarly to when debugging
1786 live processes. As a result, when debugging a core dump file, GDB
1787 is now able to display pthread_t ids of threads. For example, "info
1788 threads" shows the same output as when debugging the process when it
1789 was live. In earlier releases, you'd see something like this:
1792 * 1 LWP 6780 main () at main.c:10
1794 While now you see this:
1797 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1799 It is also now possible to inspect TLS variables when debugging core
1802 When debugging a core dump generated on a machine other than the one
1803 used to run GDB, you may need to point GDB at the correct
1804 libthread_db library with the "set libthread-db-search-path"
1805 command. See the user manual for more details on this command.
1807 * When natively debugging programs on PowerPC BookE processors running
1808 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1809 which stop execution of the inferior whenever it executes an instruction
1810 at any address within the specified range. See the "PowerPC Embedded"
1811 section in the user manual for more details.
1813 * New features in the GDB remote stub, GDBserver
1815 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1816 and i686 LynxOS (version 5.x).
1818 ** GDBserver is now supported on Blackfin Linux.
1820 * New native configurations
1822 ia64 HP-UX ia64-*-hpux*
1826 Analog Devices, Inc. Blackfin Processor bfin-*
1828 * Ada task switching is now supported on sparc-elf targets when
1829 debugging a program using the Ravenscar Profile. For more information,
1830 see the "Tasking Support when using the Ravenscar Profile" section
1831 in the GDB user manual.
1833 * Guile support was removed.
1835 * New features in the GNU simulator
1837 ** The --map-info flag lists all known core mappings.
1839 ** CFI flashes may be simulated via the "cfi" device.
1841 *** Changes in GDB 7.2
1843 * Shared library support for remote targets by default
1845 When GDB is configured for a generic, non-OS specific target, like
1846 for example, --target=arm-eabi or one of the many *-*-elf targets,
1847 GDB now queries remote stubs for loaded shared libraries using the
1848 `qXfer:libraries:read' packet. Previously, shared library support
1849 was always disabled for such configurations.
1853 ** Argument Dependent Lookup (ADL)
1855 In C++ ADL lookup directs function search to the namespaces of its
1856 arguments even if the namespace has not been imported.
1866 Here the compiler will search for `foo' in the namespace of 'b'
1867 and find A::foo. GDB now supports this. This construct is commonly
1868 used in the Standard Template Library for operators.
1870 ** Improved User Defined Operator Support
1872 In addition to member operators, GDB now supports lookup of operators
1873 defined in a namespace and imported with a `using' directive, operators
1874 defined in the global scope, operators imported implicitly from an
1875 anonymous namespace, and the ADL operators mentioned in the previous
1877 GDB now also supports proper overload resolution for all the previously
1878 mentioned flavors of operators.
1880 ** static const class members
1882 Printing of static const class members that are initialized in the
1883 class definition has been fixed.
1885 * Windows Thread Information Block access.
1887 On Windows targets, GDB now supports displaying the Windows Thread
1888 Information Block (TIB) structure. This structure is visible either
1889 by using the new command `info w32 thread-information-block' or, by
1890 dereferencing the new convenience variable named `$_tlb', a
1891 thread-specific pointer to the TIB. This feature is also supported
1892 when remote debugging using GDBserver.
1894 * Static tracepoints
1896 Static tracepoints are calls in the user program into a tracing
1897 library. One such library is a port of the LTTng kernel tracer to
1898 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1899 When debugging with GDBserver, GDB now supports combining the GDB
1900 tracepoint machinery with such libraries. For example: the user can
1901 use GDB to probe a static tracepoint marker (a call from the user
1902 program into the tracing library) with the new "strace" command (see
1903 "New commands" below). This creates a "static tracepoint" in the
1904 breakpoint list, that can be manipulated with the same feature set
1905 as fast and regular tracepoints. E.g., collect registers, local and
1906 global variables, collect trace state variables, and define
1907 tracepoint conditions. In addition, the user can collect extra
1908 static tracepoint marker specific data, by collecting the new
1909 $_sdata internal variable. When analyzing the trace buffer, you can
1910 inspect $_sdata like any other variable available to GDB. For more
1911 information, see the "Tracepoints" chapter in GDB user manual. New
1912 remote packets have been defined to support static tracepoints, see
1913 the "New remote packets" section below.
1915 * Better reconstruction of tracepoints after disconnected tracing
1917 GDB will attempt to download the original source form of tracepoint
1918 definitions when starting a trace run, and then will upload these
1919 upon reconnection to the target, resulting in a more accurate
1920 reconstruction of the tracepoints that are in use on the target.
1924 You can now exercise direct control over the ways that GDB can
1925 affect your program. For instance, you can disallow the setting of
1926 breakpoints, so that the program can run continuously (assuming
1927 non-stop mode). In addition, the "observer" variable is available
1928 to switch all of the different controls; in observer mode, GDB
1929 cannot affect the target's behavior at all, which is useful for
1930 tasks like diagnosing live systems in the field.
1932 * The new convenience variable $_thread holds the number of the
1935 * New remote packets
1939 Return the address of the Windows Thread Information Block of a given thread.
1943 In response to several of the tracepoint packets, the target may now
1944 also respond with a number of intermediate `qRelocInsn' request
1945 packets before the final result packet, to have GDB handle
1946 relocating an instruction to execute at a different address. This
1947 is particularly useful for stubs that support fast tracepoints. GDB
1948 reports support for this feature in the qSupported packet.
1952 List static tracepoint markers in the target program.
1956 List static tracepoint markers at a given address in the target
1959 qXfer:statictrace:read
1961 Read the static trace data collected (by a `collect $_sdata'
1962 tracepoint action). The remote stub reports support for this packet
1963 to gdb's qSupported query.
1967 Send the current settings of GDB's permission flags.
1971 Send part of the source (textual) form of a tracepoint definition,
1972 which includes location, conditional, and action list.
1974 * The source command now accepts a -s option to force searching for the
1975 script in the source search path even if the script name specifies
1978 * New features in the GDB remote stub, GDBserver
1980 - GDBserver now support tracepoints (including fast tracepoints, and
1981 static tracepoints). The feature is currently supported by the
1982 i386-linux and amd64-linux builds. See the "Tracepoints support
1983 in gdbserver" section in the manual for more information.
1985 GDBserver JIT compiles the tracepoint's conditional agent
1986 expression bytecode into native code whenever possible for low
1987 overhead dynamic tracepoints conditionals. For such tracepoints,
1988 an expression that examines program state is evaluated when the
1989 tracepoint is reached, in order to determine whether to capture
1990 trace data. If the condition is simple and false, processing the
1991 tracepoint finishes very quickly and no data is gathered.
1993 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1994 for static tracepoints support.
1996 - GDBserver now supports x86_64 Windows 64-bit debugging.
1998 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1999 it understands register description.
2001 * The --batch flag now disables pagination and queries.
2003 * X86 general purpose registers
2005 GDB now supports reading/writing byte, word and double-word x86
2006 general purpose registers directly. This means you can use, say,
2007 $ah or $ax to refer, respectively, to the byte register AH and
2008 16-bit word register AX that are actually portions of the 32-bit
2009 register EAX or 64-bit register RAX.
2011 * The `commands' command now accepts a range of breakpoints to modify.
2012 A plain `commands' following a command that creates multiple
2013 breakpoints affects all the breakpoints set by that command. This
2014 applies to breakpoints set by `rbreak', and also applies when a
2015 single `break' command creates multiple breakpoints (e.g.,
2016 breakpoints on overloaded c++ functions).
2018 * The `rbreak' command now accepts a filename specification as part of
2019 its argument, limiting the functions selected by the regex to those
2020 in the specified file.
2022 * Support for remote debugging Windows and SymbianOS shared libraries
2023 from Unix hosts has been improved. Non Windows GDB builds now can
2024 understand target reported file names that follow MS-DOS based file
2025 system semantics, such as file names that include drive letters and
2026 use the backslash character as directory separator. This makes it
2027 possible to transparently use the "set sysroot" and "set
2028 solib-search-path" on Unix hosts to point as host copies of the
2029 target's shared libraries. See the new command "set
2030 target-file-system-kind" described below, and the "Commands to
2031 specify files" section in the user manual for more information.
2035 eval template, expressions...
2036 Convert the values of one or more expressions under the control
2037 of the string template to a command line, and call it.
2039 set target-file-system-kind unix|dos-based|auto
2040 show target-file-system-kind
2041 Set or show the assumed file system kind for target reported file
2044 save breakpoints <filename>
2045 Save all current breakpoint definitions to a file suitable for use
2046 in a later debugging session. To read the saved breakpoint
2047 definitions, use the `source' command.
2049 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2052 info static-tracepoint-markers
2053 Display information about static tracepoint markers in the target.
2055 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2056 Define a static tracepoint by probing a marker at the given
2057 function, line, address, or marker ID.
2061 Enable and disable observer mode.
2063 set may-write-registers on|off
2064 set may-write-memory on|off
2065 set may-insert-breakpoints on|off
2066 set may-insert-tracepoints on|off
2067 set may-insert-fast-tracepoints on|off
2068 set may-interrupt on|off
2069 Set individual permissions for GDB effects on the target. Note that
2070 some of these settings can have undesirable or surprising
2071 consequences, particularly when changed in the middle of a session.
2072 For instance, disabling the writing of memory can prevent
2073 breakpoints from being inserted, cause single-stepping to fail, or
2074 even crash your program, if you disable after breakpoints have been
2075 inserted. However, GDB should not crash.
2077 set record memory-query on|off
2078 show record memory-query
2079 Control whether to stop the inferior if memory changes caused
2080 by an instruction cannot be recorded.
2085 The disassemble command now supports "start,+length" form of two arguments.
2089 ** GDB now provides a new directory location, called the python directory,
2090 where Python scripts written for GDB can be installed. The location
2091 of that directory is <data-directory>/python, where <data-directory>
2092 is the GDB data directory. For more details, see section `Scripting
2093 GDB using Python' in the manual.
2095 ** The GDB Python API now has access to breakpoints, symbols, symbol
2096 tables, program spaces, inferiors, threads and frame's code blocks.
2097 Additionally, GDB Parameters can now be created from the API, and
2098 manipulated via set/show in the CLI.
2100 ** New functions gdb.target_charset, gdb.target_wide_charset,
2101 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2103 ** New exception gdb.GdbError.
2105 ** Pretty-printers are now also looked up in the current program space.
2107 ** Pretty-printers can now be individually enabled and disabled.
2109 ** GDB now looks for names of Python scripts to auto-load in a
2110 special section named `.debug_gdb_scripts', in addition to looking
2111 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2113 * Tracepoint actions were unified with breakpoint commands. In particular,
2114 there are no longer differences in "info break" output for breakpoints and
2115 tracepoints and the "commands" command can be used for both tracepoints and
2116 regular breakpoints.
2120 ARM Symbian arm*-*-symbianelf*
2122 * D language support.
2123 GDB now supports debugging programs written in the D programming
2126 * GDB now supports the extended ptrace interface for PowerPC which is
2127 available since Linux kernel version 2.6.34. This automatically enables
2128 any hardware breakpoints and additional hardware watchpoints available in
2129 the processor. The old ptrace interface exposes just one hardware
2130 watchpoint and no hardware breakpoints.
2132 * GDB is now able to use the Data Value Compare (DVC) register available on
2133 embedded PowerPC processors to implement in hardware simple watchpoint
2134 conditions of the form:
2136 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2138 This works in native GDB running on Linux kernels with the extended ptrace
2139 interface mentioned above.
2141 *** Changes in GDB 7.1
2145 ** Namespace Support
2147 GDB now supports importing of namespaces in C++. This enables the
2148 user to inspect variables from imported namespaces. Support for
2149 namepace aliasing has also been added. So, if a namespace is
2150 aliased in the current scope (e.g. namepace C=A; ) the user can
2151 print variables using the alias (e.g. (gdb) print C::x).
2155 All known bugs relating to the printing of virtual base class were
2156 fixed. It is now possible to call overloaded static methods using a
2161 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2162 and reinterpret_cast<> are now handled by the C++ expression parser.
2166 Xilinx MicroBlaze microblaze-*-*
2171 Xilinx MicroBlaze microblaze
2174 * Multi-program debugging.
2176 GDB now has support for multi-program (a.k.a. multi-executable or
2177 multi-exec) debugging. This allows for debugging multiple inferiors
2178 simultaneously each running a different program under the same GDB
2179 session. See "Debugging Multiple Inferiors and Programs" in the
2180 manual for more information. This implied some user visible changes
2181 in the multi-inferior support. For example, "info inferiors" now
2182 lists inferiors that are not running yet or that have exited
2183 already. See also "New commands" and "New options" below.
2185 * New tracing features
2187 GDB's tracepoint facility now includes several new features:
2189 ** Trace state variables
2191 GDB tracepoints now include support for trace state variables, which
2192 are variables managed by the target agent during a tracing
2193 experiment. They are useful for tracepoints that trigger each
2194 other, so for instance one tracepoint can count hits in a variable,
2195 and then a second tracepoint has a condition that is true when the
2196 count reaches a particular value. Trace state variables share the
2197 $-syntax of GDB convenience variables, and can appear in both
2198 tracepoint actions and condition expressions. Use the "tvariable"
2199 command to create, and "info tvariables" to view; see "Trace State
2200 Variables" in the manual for more detail.
2204 GDB now includes an option for defining fast tracepoints, which
2205 targets may implement more efficiently, such as by installing a jump
2206 into the target agent rather than a trap instruction. The resulting
2207 speedup can be by two orders of magnitude or more, although the
2208 tradeoff is that some program locations on some target architectures
2209 might not allow fast tracepoint installation, for instance if the
2210 instruction to be replaced is shorter than the jump. To request a
2211 fast tracepoint, use the "ftrace" command, with syntax identical to
2212 the regular trace command.
2214 ** Disconnected tracing
2216 It is now possible to detach GDB from the target while it is running
2217 a trace experiment, then reconnect later to see how the experiment
2218 is going. In addition, a new variable disconnected-tracing lets you
2219 tell the target agent whether to continue running a trace if the
2220 connection is lost unexpectedly.
2224 GDB now has the ability to save the trace buffer into a file, and
2225 then use that file as a target, similarly to you can do with
2226 corefiles. You can select trace frames, print data that was
2227 collected in them, and use tstatus to display the state of the
2228 tracing run at the moment that it was saved. To create a trace
2229 file, use "tsave <filename>", and to use it, do "target tfile
2232 ** Circular trace buffer
2234 You can ask the target agent to handle the trace buffer as a
2235 circular buffer, discarding the oldest trace frames to make room for
2236 newer ones, by setting circular-trace-buffer to on. This feature may
2237 not be available for all target agents.
2242 The disassemble command, when invoked with two arguments, now requires
2243 the arguments to be comma-separated.
2246 The info variables command now displays variable definitions. Files
2247 which only declare a variable are not shown.
2250 The source command is now capable of sourcing Python scripts.
2251 This feature is dependent on the debugger being build with Python
2254 Related to this enhancement is also the introduction of a new command
2255 "set script-extension" (see below).
2257 * New commands (for set/show, see "New options" below)
2259 record save [<FILENAME>]
2260 Save a file (in core file format) containing the process record
2261 execution log for replay debugging at a later time.
2263 record restore <FILENAME>
2264 Restore the process record execution log that was saved at an
2265 earlier time, for replay debugging.
2267 add-inferior [-copies <N>] [-exec <FILENAME>]
2270 clone-inferior [-copies <N>] [ID]
2271 Make a new inferior ready to execute the same program another
2272 inferior has loaded.
2277 maint info program-spaces
2278 List the program spaces loaded into GDB.
2280 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2281 show remote interrupt-sequence
2282 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2283 as the sequence to the remote target in order to interrupt the execution.
2284 Ctrl-C is a default. Some system prefers BREAK which is high level of
2285 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2286 Magic SysRq g. It is BREAK signal and character 'g'.
2288 set remote interrupt-on-connect [on | off]
2289 show remote interrupt-on-connect
2290 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2291 remote target when gdb connects to it. This is needed when you debug
2294 set remotebreak [on | off]
2296 Deprecated. Use "set/show remote interrupt-sequence" instead.
2298 tvariable $NAME [ = EXP ]
2299 Create or modify a trace state variable.
2302 List trace state variables and their values.
2304 delete tvariable $NAME ...
2305 Delete one or more trace state variables.
2308 Evaluate the given expressions without collecting anything into the
2309 trace buffer. (Valid in tracepoint actions only.)
2311 ftrace FN / FILE:LINE / *ADDR
2312 Define a fast tracepoint at the given function, line, or address.
2314 * New expression syntax
2316 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2317 GDB now parses 0b101010 identically with 42.
2321 set follow-exec-mode new|same
2322 show follow-exec-mode
2323 Control whether GDB reuses the same inferior across an exec call or
2324 creates a new one. This is useful to be able to restart the old
2325 executable after the inferior having done an exec call.
2327 set default-collect EXPR, ...
2328 show default-collect
2329 Define a list of expressions to be collected at each tracepoint.
2330 This is a useful way to ensure essential items are not overlooked,
2331 such as registers or a critical global variable.
2333 set disconnected-tracing
2334 show disconnected-tracing
2335 If set to 1, the target is instructed to continue tracing if it
2336 loses its connection to GDB. If 0, the target is to stop tracing
2339 set circular-trace-buffer
2340 show circular-trace-buffer
2341 If set to on, the target is instructed to use a circular trace buffer
2342 and discard the oldest trace frames instead of stopping the trace due
2343 to a full trace buffer. If set to off, the trace stops when the buffer
2344 fills up. Some targets may not support this.
2346 set script-extension off|soft|strict
2347 show script-extension
2348 If set to "off", the debugger does not perform any script language
2349 recognition, and all sourced files are assumed to be GDB scripts.
2350 If set to "soft" (the default), files are sourced according to
2351 filename extension, falling back to GDB scripts if the first
2353 If set to "strict", files are sourced according to filename extension.
2355 set ada trust-PAD-over-XVS on|off
2356 show ada trust-PAD-over-XVS
2357 If off, activate a workaround against a bug in the debugging information
2358 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2359 the GCC sources for more information about the GNAT encoding and
2360 PAD types in particular). It is always safe to set this option to
2361 off, but this introduces a slight performance penalty. The default
2364 * Python API Improvements
2366 ** GDB provides the new class gdb.LazyString. This is useful in
2367 some pretty-printing cases. The new method gdb.Value.lazy_string
2368 provides a simple way to create objects of this type.
2370 ** The fields returned by gdb.Type.fields now have an
2371 `is_base_class' attribute.
2373 ** The new method gdb.Type.range returns the range of an array type.
2375 ** The new method gdb.parse_and_eval can be used to parse and
2376 evaluate an expression.
2378 * New remote packets
2381 Define a trace state variable.
2384 Get the current value of a trace state variable.
2387 Set desired tracing behavior upon disconnection.
2390 Set the trace buffer to be linear or circular.
2393 Get data about the tracepoints currently in use.
2397 Process record now works correctly with hardware watchpoints.
2399 Multiple bug fixes have been made to the mips-irix port, making it
2400 much more reliable. In particular:
2401 - Debugging threaded applications is now possible again. Previously,
2402 GDB would hang while starting the program, or while waiting for
2403 the program to stop at a breakpoint.
2404 - Attaching to a running process no longer hangs.
2405 - An error occurring while loading a core file has been fixed.
2406 - Changing the value of the PC register now works again. This fixes
2407 problems observed when using the "jump" command, or when calling
2408 a function from GDB, or even when assigning a new value to $pc.
2409 - With the "finish" and "return" commands, the return value for functions
2410 returning a small array is now correctly printed.
2411 - It is now possible to break on shared library code which gets executed
2412 during a shared library init phase (code executed while executing
2413 their .init section). Previously, the breakpoint would have no effect.
2414 - GDB is now able to backtrace through the signal handler for
2415 non-threaded programs.
2417 PIE (Position Independent Executable) programs debugging is now supported.
2418 This includes debugging execution of PIC (Position Independent Code) shared
2419 libraries although for that, it should be possible to run such libraries as an
2422 *** Changes in GDB 7.0
2424 * GDB now has an interface for JIT compilation. Applications that
2425 dynamically generate code can create symbol files in memory and register
2426 them with GDB. For users, the feature should work transparently, and
2427 for JIT developers, the interface is documented in the GDB manual in the
2428 "JIT Compilation Interface" chapter.
2430 * Tracepoints may now be conditional. The syntax is as for
2431 breakpoints; either an "if" clause appended to the "trace" command,
2432 or the "condition" command is available. GDB sends the condition to
2433 the target for evaluation using the same bytecode format as is used
2434 for tracepoint actions.
2436 * The disassemble command now supports: an optional /r modifier, print the
2437 raw instructions in hex as well as in symbolic form, and an optional /m
2438 modifier to print mixed source+assembly.
2440 * Process record and replay
2442 In a architecture environment that supports ``process record and
2443 replay'', ``process record and replay'' target can record a log of
2444 the process execution, and replay it with both forward and reverse
2447 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2448 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2449 set execution-direction {forward|reverse}, for targets that support
2452 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2453 feature is available with a native GDB running on kernel version
2456 * GDB now has support for multi-byte and wide character sets on the
2457 target. Strings whose character type is wchar_t, char16_t, or
2458 char32_t are now correctly printed. GDB supports wide- and unicode-
2459 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2460 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2461 `printf'. This feature requires iconv to work properly; if your
2462 system does not have a working iconv, GDB can use GNU libiconv. See
2463 the installation instructions for more information.
2465 * GDB now supports automatic retrieval of shared library files from
2466 remote targets. To use this feature, specify a system root that begins
2467 with the `remote:' prefix, either via the `set sysroot' command or via
2468 the `--with-sysroot' configure-time option.
2470 * "info sharedlibrary" now takes an optional regex of libraries to show,
2471 and it now reports if a shared library has no debugging information.
2473 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2474 now complete on file names.
2476 * When completing in expressions, gdb will attempt to limit
2477 completions to allowable structure or union fields, where appropriate.
2478 For instance, consider:
2480 # struct example { int f1; double f2; };
2481 # struct example variable;
2484 If the user types TAB at the end of this command line, the available
2485 completions will be "f1" and "f2".
2487 * Inlined functions are now supported. They show up in backtraces, and
2488 the "step", "next", and "finish" commands handle them automatically.
2490 * GDB now supports the token-splicing (##) and stringification (#)
2491 operators when expanding macros. It also supports variable-arity
2494 * GDB now supports inspecting extra signal information, exported by
2495 the new $_siginfo convenience variable. The feature is currently
2496 implemented on linux ARM, i386 and amd64.
2498 * GDB can now display the VFP floating point registers and NEON vector
2499 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2500 can provide these registers (requires Linux 2.6.30 or later). Remote
2501 and simulator targets may also provide them.
2503 * New remote packets
2506 Search memory for a sequence of bytes.
2509 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2510 operation over reliable transport links. Use of this packet is
2511 controlled by the `set remote noack-packet' command.
2514 Kill the process with the specified process ID. Use this in preference
2515 to `k' when multiprocess protocol extensions are supported.
2518 Obtains additional operating system information
2522 Read or write additional signal information.
2524 * Removed remote protocol undocumented extension
2526 An undocumented extension to the remote protocol's `S' stop reply
2527 packet that permited the stub to pass a process id was removed.
2528 Remote servers should use the `T' stop reply packet instead.
2530 * GDB now supports multiple function calling conventions according to the
2531 DWARF-2 DW_AT_calling_convention function attribute.
2533 * The SH target utilizes the aforementioned change to distinguish between gcc
2534 and Renesas calling convention. It also adds the new CLI commands
2535 `set/show sh calling-convention'.
2537 * GDB can now read compressed debug sections, as produced by GNU gold
2538 with the --compress-debug-sections=zlib flag.
2540 * 64-bit core files are now supported on AIX.
2542 * Thread switching is now supported on Tru64.
2544 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2545 which will be allocated using malloc later in program execution.
2547 * The qXfer:libraries:read remote procotol packet now allows passing a
2548 list of section offsets.
2550 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2551 conditions handling signals delivered during attach or thread creation
2552 have also been fixed.
2554 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2555 From the user's standpoint, all unqualified instances of True and False
2556 are treated as the standard definitions, regardless of context.
2558 * GDB now parses C++ symbol and type names more flexibly. For
2561 template<typename T> class C { };
2564 GDB will now correctly handle all of:
2566 ptype C<char const *>
2567 ptype C<char const*>
2568 ptype C<const char *>
2569 ptype C<const char*>
2571 * New features in the GDB remote stub, gdbserver
2573 - The "--wrapper" command-line argument tells gdbserver to use a
2574 wrapper program to launch programs for debugging.
2576 - On PowerPC and S/390 targets, it is now possible to use a single
2577 gdbserver executable to debug both 32-bit and 64-bit programs.
2578 (This requires gdbserver itself to be built as a 64-bit executable.)
2580 - gdbserver uses the new noack protocol mode for TCP connections to
2581 reduce communications latency, if also supported and enabled in GDB.
2583 - Support for the sparc64-linux-gnu target is now included in
2586 - The amd64-linux build of gdbserver now supports debugging both
2587 32-bit and 64-bit programs.
2589 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2590 now support hardware watchpoints, and will use them automatically
2595 GDB now has support for scripting using Python. Whether this is
2596 available is determined at configure time.
2598 New GDB commands can now be written in Python.
2600 * Ada tasking support
2602 Ada tasks can now be inspected in GDB. The following commands have
2606 Print the list of Ada tasks.
2608 Print detailed information about task number N.
2610 Print the task number of the current task.
2612 Switch the context of debugging to task number N.
2614 * Support for user-defined prefixed commands. The "define" command can
2615 add new commands to existing prefixes, e.g. "target".
2617 * Multi-inferior, multi-process debugging.
2619 GDB now has generalized support for multi-inferior debugging. See
2620 "Debugging Multiple Inferiors" in the manual for more information.
2621 Although availability still depends on target support, the command
2622 set is more uniform now. The GNU/Linux specific multi-forks support
2623 has been migrated to this new framework. This implied some user
2624 visible changes; see "New commands" and also "Removed commands"
2627 * Target descriptions can now describe the target OS ABI. See the
2628 "Target Description Format" section in the user manual for more
2631 * Target descriptions can now describe "compatible" architectures
2632 to indicate that the target can execute applications for a different
2633 architecture in addition to those for the main target architecture.
2634 See the "Target Description Format" section in the user manual for
2637 * Multi-architecture debugging.
2639 GDB now includes general supports for debugging applications on
2640 hybrid systems that use more than one single processor architecture
2641 at the same time. Each such hybrid architecture still requires
2642 specific support to be added. The only hybrid architecture supported
2643 in this version of GDB is the Cell Broadband Engine.
2645 * GDB now supports integrated debugging of Cell/B.E. applications that
2646 use both the PPU and SPU architectures. To enable support for hybrid
2647 Cell/B.E. debugging, you need to configure GDB to support both the
2648 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2649 --enable-targets configure option.
2651 * Non-stop mode debugging.
2653 For some targets, GDB now supports an optional mode of operation in
2654 which you can examine stopped threads while other threads continue
2655 to execute freely. This is referred to as non-stop mode, with the
2656 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2657 section in the user manual for more information.
2659 To be able to support remote non-stop debugging, a remote stub needs
2660 to implement the non-stop mode remote protocol extensions, as
2661 described in the "Remote Non-Stop" section of the user manual. The
2662 GDB remote stub, gdbserver, has been adjusted to support these
2663 extensions on linux targets.
2665 * New commands (for set/show, see "New options" below)
2667 catch syscall [NAME(S) | NUMBER(S)]
2668 Catch system calls. Arguments, which should be names of system
2669 calls or their numbers, mean catch only those syscalls. Without
2670 arguments, every syscall will be caught. When the inferior issues
2671 any of the specified syscalls, GDB will stop and announce the system
2672 call, both when it is called and when its call returns. This
2673 feature is currently available with a native GDB running on the
2674 Linux Kernel, under the following architectures: x86, x86_64,
2675 PowerPC and PowerPC64.
2677 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2679 Search memory for a sequence of bytes.
2681 maint set python print-stack
2682 maint show python print-stack
2683 Show a stack trace when an error is encountered in a Python script.
2686 Invoke CODE by passing it to the Python interpreter.
2691 These allow macros to be defined, undefined, and listed
2695 Show operating system information about processes.
2698 List the inferiors currently under GDB's control.
2701 Switch focus to inferior number NUM.
2704 Detach from inferior number NUM.
2707 Kill inferior number NUM.
2711 set spu stop-on-load
2712 show spu stop-on-load
2713 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2715 set spu auto-flush-cache
2716 show spu auto-flush-cache
2717 Control whether to automatically flush the software-managed cache
2718 during Cell/B.E. debugging.
2720 set sh calling-convention
2721 show sh calling-convention
2722 Control the calling convention used when calling SH target functions.
2725 show debug timestamp
2726 Control display of timestamps with GDB debugging output.
2728 set disassemble-next-line
2729 show disassemble-next-line
2730 Control display of disassembled source lines or instructions when
2733 set remote noack-packet
2734 show remote noack-packet
2735 Set/show the use of remote protocol QStartNoAckMode packet. See above
2736 under "New remote packets."
2738 set remote query-attached-packet
2739 show remote query-attached-packet
2740 Control use of remote protocol `qAttached' (query-attached) packet.
2742 set remote read-siginfo-object
2743 show remote read-siginfo-object
2744 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2747 set remote write-siginfo-object
2748 show remote write-siginfo-object
2749 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2752 set remote reverse-continue
2753 show remote reverse-continue
2754 Control use of remote protocol 'bc' (reverse-continue) packet.
2756 set remote reverse-step
2757 show remote reverse-step
2758 Control use of remote protocol 'bs' (reverse-step) packet.
2760 set displaced-stepping
2761 show displaced-stepping
2762 Control displaced stepping mode. Displaced stepping is a way to
2763 single-step over breakpoints without removing them from the debuggee.
2764 Also known as "out-of-line single-stepping".
2767 show debug displaced
2768 Control display of debugging info for displaced stepping.
2770 maint set internal-error
2771 maint show internal-error
2772 Control what GDB does when an internal error is detected.
2774 maint set internal-warning
2775 maint show internal-warning
2776 Control what GDB does when an internal warning is detected.
2781 Use a wrapper program to launch programs for debugging.
2783 set multiple-symbols (all|ask|cancel)
2784 show multiple-symbols
2785 The value of this variable can be changed to adjust the debugger behavior
2786 when an expression or a breakpoint location contains an ambiguous symbol
2787 name (an overloaded function name, for instance).
2789 set breakpoint always-inserted
2790 show breakpoint always-inserted
2791 Keep breakpoints always inserted in the target, as opposed to inserting
2792 them when resuming the target, and removing them when the target stops.
2793 This option can improve debugger performance on slow remote targets.
2795 set arm fallback-mode (arm|thumb|auto)
2796 show arm fallback-mode
2797 set arm force-mode (arm|thumb|auto)
2799 These commands control how ARM GDB determines whether instructions
2800 are ARM or Thumb. The default for both settings is auto, which uses
2801 the current CPSR value for instructions without symbols; previous
2802 versions of GDB behaved as if "set arm fallback-mode arm".
2804 set disable-randomization
2805 show disable-randomization
2806 Standalone programs run with the virtual address space randomization enabled
2807 by default on some platforms. This option keeps the addresses stable across
2808 multiple debugging sessions.
2812 Control whether other threads are stopped or not when some thread hits
2817 Requests that asynchronous execution is enabled in the target, if available.
2818 In this case, it's possible to resume target in the background, and interact
2819 with GDB while the target is running. "show target-async" displays the
2820 current state of asynchronous execution of the target.
2822 set target-wide-charset
2823 show target-wide-charset
2824 The target-wide-charset is the name of the character set that GDB
2825 uses when printing characters whose type is wchar_t.
2827 set tcp auto-retry (on|off)
2829 set tcp connect-timeout
2830 show tcp connect-timeout
2831 These commands allow GDB to retry failed TCP connections to a remote stub
2832 with a specified timeout period; this is useful if the stub is launched
2833 in parallel with GDB but may not be ready to accept connections immediately.
2835 set libthread-db-search-path
2836 show libthread-db-search-path
2837 Control list of directories which GDB will search for appropriate
2840 set schedule-multiple (on|off)
2841 show schedule-multiple
2842 Allow GDB to resume all threads of all processes or only threads of
2843 the current process.
2847 Use more aggressive caching for accesses to the stack. This improves
2848 performance of remote debugging (particularly backtraces) without
2849 affecting correctness.
2851 set interactive-mode (on|off|auto)
2852 show interactive-mode
2853 Control whether GDB runs in interactive mode (on) or not (off).
2854 When in interactive mode, GDB waits for the user to answer all
2855 queries. Otherwise, GDB does not wait and assumes the default
2856 answer. When set to auto (the default), GDB determines which
2857 mode to use based on the stdin settings.
2862 For program forks, this is replaced by the new more generic `info
2863 inferiors' command. To list checkpoints, you can still use the
2864 `info checkpoints' command, which was an alias for the `info forks'
2868 Replaced by the new `inferior' command. To switch between
2869 checkpoints, you can still use the `restart' command, which was an
2870 alias for the `fork' command.
2873 This is removed, since some targets don't have a notion of
2874 processes. To switch between processes, you can still use the
2875 `inferior' command using GDB's own inferior number.
2878 For program forks, this is replaced by the new more generic `kill
2879 inferior' command. To delete a checkpoint, you can still use the
2880 `delete checkpoint' command, which was an alias for the `delete
2884 For program forks, this is replaced by the new more generic `detach
2885 inferior' command. To detach a checkpoint, you can still use the
2886 `detach checkpoint' command, which was an alias for the `detach
2889 * New native configurations
2891 x86/x86_64 Darwin i[34567]86-*-darwin*
2893 x86_64 MinGW x86_64-*-mingw*
2897 Lattice Mico32 lm32-*
2898 x86 DICOS i[34567]86-*-dicos*
2899 x86_64 DICOS x86_64-*-dicos*
2902 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2903 (mingw32ce) debugging.
2909 These commands were actually not implemented on any target.
2911 *** Changes in GDB 6.8
2913 * New native configurations
2915 NetBSD/hppa hppa*-*netbsd*
2916 Xtensa GNU/Linux xtensa*-*-linux*
2920 NetBSD/hppa hppa*-*-netbsd*
2921 Xtensa GNU/Lunux xtensa*-*-linux*
2923 * Change in command line behavior -- corefiles vs. process ids.
2925 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2926 attaching to process NUMBER fails, GDB no longer attempts to open a
2927 core file named NUMBER. Attaching to a program using the -c option
2928 is no longer supported. Instead, use the '-p' or '--pid' options.
2930 * GDB can now be built as a native debugger for debugging Windows x86
2931 (mingw32) Portable Executable (PE) programs.
2933 * Pending breakpoints no longer change their number when their address
2936 * GDB now supports breakpoints with multiple locations,
2937 including breakpoints on C++ constructors, inside C++ templates,
2938 and in inlined functions.
2940 * GDB's ability to debug optimized code has been improved. GDB more
2941 accurately identifies function bodies and lexical blocks that occupy
2942 more than one contiguous range of addresses.
2944 * Target descriptions can now describe registers for PowerPC.
2946 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2947 registers on PowerPC targets.
2949 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2950 targets even when the libthread_db library is not available.
2952 * The GDB remote stub, gdbserver, now supports the new file transfer
2953 commands (remote put, remote get, and remote delete).
2955 * The GDB remote stub, gdbserver, now supports run and attach in
2956 extended-remote mode.
2958 * hppa*64*-*-hpux11* target broken
2959 The debugger is unable to start a program and fails with the following
2960 error: "Error trying to get information about dynamic linker".
2961 The gdb-6.7 release is also affected.
2963 * GDB now supports the --enable-targets= configure option to allow
2964 building a single GDB executable that supports multiple remote
2965 target architectures.
2967 * GDB now supports debugging C and C++ programs which use the
2968 Decimal Floating Point extension. In addition, the PowerPC target
2969 now has a set of pseudo-registers to inspect decimal float values
2970 stored in two consecutive float registers.
2972 * The -break-insert MI command can optionally create pending
2975 * Improved support for debugging Ada
2976 Many improvements to the Ada language support have been made. These
2978 - Better support for Ada2005 interface types
2979 - Improved handling of arrays and slices in general
2980 - Better support for Taft-amendment types
2981 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2983 - Improved command completion in Ada
2986 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2991 set print frame-arguments (all|scalars|none)
2992 show print frame-arguments
2993 The value of this variable can be changed to control which argument
2994 values should be printed by the debugger when displaying a frame.
2999 Transfer files to and from a remote target, and delete remote files.
3006 Transfer files to and from a remote target, and delete remote files.
3008 * New remote packets
3015 Open, close, read, write, and delete files on the remote system.
3018 Attach to an existing process on the remote system, in extended-remote
3022 Run a new process on the remote system, in extended-remote mode.
3024 *** Changes in GDB 6.7
3026 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3027 bfd, libiberty and opcodes, as revealed by static analysis donated by
3028 Coverity, Inc. (http://scan.coverity.com).
3030 * When looking up multiply-defined global symbols, GDB will now prefer the
3031 symbol definition in the current shared library if it was built using the
3032 -Bsymbolic linker option.
3034 * When the Text User Interface (TUI) is not configured, GDB will now
3035 recognize the -tui command-line option and print a message that the TUI
3038 * The GDB remote stub, gdbserver, now has lower overhead for high
3039 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3041 * GDB for MIPS targets now autodetects whether a remote target provides
3042 32-bit or 64-bit register values.
3044 * Support for C++ member pointers has been improved.
3046 * GDB now understands XML target descriptions, which specify the
3047 target's overall architecture. GDB can read a description from
3048 a local file or over the remote serial protocol.
3050 * Vectors of single-byte data use a new integer type which is not
3051 automatically displayed as character or string data.
3053 * The /s format now works with the print command. It displays
3054 arrays of single-byte integers and pointers to single-byte integers
3057 * Target descriptions can now describe target-specific registers,
3058 for architectures which have implemented the support (currently
3059 only ARM, M68K, and MIPS).
3061 * GDB and the GDB remote stub, gdbserver, now support the XScale
3064 * The GDB remote stub, gdbserver, has been updated to support
3065 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3066 has been rewritten to use the standard GDB remote protocol.
3068 * GDB can now step into C++ functions which are called through thunks.
3070 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3072 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3073 layout. It also supports a TextSeg= and DataSeg= response when only
3074 segment base addresses (rather than offsets) are available.
3076 * The /i format now outputs any trailing branch delay slot instructions
3077 immediately following the last instruction within the count specified.
3079 * The GDB remote protocol "T" stop reply packet now supports a
3080 "library" response. Combined with the new "qXfer:libraries:read"
3081 packet, this response allows GDB to debug shared libraries on targets
3082 where the operating system manages the list of loaded libraries (e.g.
3083 Windows and SymbianOS).
3085 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3086 (DLLs) on Windows and Windows CE targets.
3088 * GDB now supports a faster verification that a .debug file matches its binary
3089 according to its build-id signature, if the signature is present.
3095 Enable or disable hardware flow control (RTS/CTS) on the serial port
3096 when debugging using remote targets.
3098 set mem inaccessible-by-default
3099 show mem inaccessible-by-default
3100 If the target supplies a memory map, for instance via the remote
3101 protocol's "qXfer:memory-map:read" packet, setting this variable
3102 prevents GDB from accessing memory outside the memory map. This
3103 is useful for targets with memory mapped registers or which react
3104 badly to accesses of unmapped address space.
3106 set breakpoint auto-hw
3107 show breakpoint auto-hw
3108 If the target supplies a memory map, for instance via the remote
3109 protocol's "qXfer:memory-map:read" packet, setting this variable
3110 lets GDB use hardware breakpoints automatically for memory regions
3111 where it can not use software breakpoints. This covers both the
3112 "break" command and internal breakpoints used for other commands
3113 including "next" and "finish".
3116 catch exception unhandled
3117 Stop the program execution when Ada exceptions are raised.
3120 Stop the program execution when an Ada assertion failed.
3124 Set an alternate system root for target files. This is a more
3125 general version of "set solib-absolute-prefix", which is now
3126 an alias to "set sysroot".
3129 Provide extended SPU facility status information. This set of
3130 commands is available only when debugging the Cell/B.E. SPU
3133 * New native configurations
3135 OpenBSD/sh sh*-*openbsd*
3138 unset tdesc filename
3140 Use the specified local file as an XML target description, and do
3141 not query the target for its built-in description.
3145 OpenBSD/sh sh*-*-openbsd*
3146 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3147 Toshiba Media Processor mep-elf
3149 * New remote packets
3152 Ignore the specified signals; pass them directly to the debugged program
3153 without stopping other threads or reporting them to GDB.
3155 qXfer:features:read:
3156 Read an XML target description from the target, which describes its
3161 Read or write contents of an spufs file on the target system. These
3162 packets are available only on the Cell/B.E. SPU architecture.
3164 qXfer:libraries:read:
3165 Report the loaded shared libraries. Combined with new "T" packet
3166 response, this packet allows GDB to debug shared libraries on
3167 targets where the operating system manages the list of loaded
3168 libraries (e.g. Windows and SymbianOS).
3172 Support for these obsolete configurations has been removed.
3180 i[34567]86-*-lynxos*
3181 i[34567]86-*-netware*
3182 i[34567]86-*-sco3.2v5*
3183 i[34567]86-*-sco3.2v4*
3185 i[34567]86-*-sysv4.2*
3188 i[34567]86-*-unixware2*
3189 i[34567]86-*-unixware*
3198 * Other removed features
3205 Various m68k-only ROM monitors.
3212 Various Renesas ROM monitors and debugging interfaces for SH and
3217 Support for a Macraigor serial interface to on-chip debugging.
3218 GDB does not directly support the newer parallel or USB
3223 A debug information format. The predecessor to DWARF 2 and
3224 DWARF 3, which are still supported.
3226 Support for the HP aCC compiler on HP-UX/PA-RISC
3228 SOM-encapsulated symbolic debugging information, automatic
3229 invocation of pxdb, and the aCC custom C++ ABI. This does not
3230 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3231 with aCC can still be debugged on an assembly level.
3233 MIPS ".pdr" sections
3235 A MIPS-specific format used to describe stack frame layout
3236 in debugging information.
3240 GDB could work with an older version of Guile to debug
3241 the interpreter and Scheme programs running in it.
3243 set mips stack-arg-size
3244 set mips saved-gpreg-size
3246 Use "set mips abi" to control parameter passing for MIPS.
3248 *** Changes in GDB 6.6
3253 Cell Broadband Engine SPU spu-elf
3255 * GDB can now be configured as a cross-debugger targeting native Windows
3256 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3257 running on a Windows system over TCP/IP to debug Windows programs.
3259 * The GDB remote stub, gdbserver, has been updated to support Windows and
3260 Cygwin debugging. Both single-threaded and multi-threaded programs are
3263 * The "set trust-readonly-sections" command works again. This command was
3264 broken in GDB 6.3, 6.4, and 6.5.
3266 * The "load" command now supports writing to flash memory, if the remote
3267 stub provides the required support.
3269 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3270 longer requires symbolic debug information (e.g. DWARF-2).
3275 unset substitute-path
3276 show substitute-path
3277 Manage a list of substitution rules that GDB uses to rewrite the name
3278 of the directories where the sources are located. This can be useful
3279 for instance when the sources were moved to a different location
3280 between compilation and debugging.
3284 Print each CLI command as it is executed. Each command is prefixed with
3285 a number of `+' symbols representing the nesting depth.
3286 The source command now has a `-v' option to enable the same feature.
3290 The ARM Demon monitor support (RDP protocol, "target rdp").
3292 Kernel Object Display, an embedded debugging feature which only worked with
3293 an obsolete version of Cisco IOS.
3295 The 'set download-write-size' and 'show download-write-size' commands.
3297 * New remote packets
3300 Tell a stub about GDB client features, and request remote target features.
3301 The first feature implemented is PacketSize, which allows the target to
3302 specify the size of packets it can handle - to minimize the number of
3303 packets required and improve performance when connected to a remote
3307 Fetch an OS auxilliary vector from the remote stub. This packet is a
3308 more efficient replacement for qPart:auxv:read.
3310 qXfer:memory-map:read:
3311 Fetch a memory map from the remote stub, including information about
3312 RAM, ROM, and flash memory devices.
3317 Erase and program a flash memory device.
3319 * Removed remote packets
3322 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3323 used it, and only gdbserver implemented it.
3325 *** Changes in GDB 6.5
3329 Renesas M32C/M16C m32c-elf
3331 Morpho Technologies ms1 ms1-elf
3335 init-if-undefined Initialize a convenience variable, but
3336 only if it doesn't already have a value.
3338 The following commands are presently only implemented for native GNU/Linux:
3340 checkpoint Save a snapshot of the program state.
3342 restart <n> Return the program state to a
3343 previously saved state.
3345 info checkpoints List currently saved checkpoints.
3347 delete-checkpoint <n> Delete a previously saved checkpoint.
3349 set|show detach-on-fork Tell gdb whether to detach from a newly
3350 forked process, or to keep debugging it.
3352 info forks List forks of the user program that
3353 are available to be debugged.
3355 fork <n> Switch to debugging one of several
3356 forks of the user program that are
3357 available to be debugged.
3359 delete-fork <n> Delete a fork from the list of forks
3360 that are available to be debugged (and
3361 kill the forked process).
3363 detach-fork <n> Delete a fork from the list of forks
3364 that are available to be debugged (and
3365 allow the process to continue).
3369 Morpho Technologies ms2 ms1-elf
3371 * Improved Windows host support
3373 GDB now builds as a cross debugger hosted on i686-mingw32, including
3374 native console support, and remote communications using either
3375 network sockets or serial ports.
3377 * Improved Modula-2 language support
3379 GDB can now print most types in the Modula-2 syntax. This includes:
3380 basic types, set types, record types, enumerated types, range types,
3381 pointer types and ARRAY types. Procedure var parameters are correctly
3382 printed and hexadecimal addresses and character constants are also
3383 written in the Modula-2 syntax. Best results can be obtained by using
3384 GNU Modula-2 together with the -gdwarf-2 command line option.
3388 The ARM rdi-share module.
3390 The Netware NLM debug server.
3392 *** Changes in GDB 6.4
3394 * New native configurations
3396 OpenBSD/arm arm*-*-openbsd*
3397 OpenBSD/mips64 mips64-*-openbsd*
3401 Morpho Technologies ms1 ms1-elf
3403 * New command line options
3405 --batch-silent As for --batch, but totally silent.
3406 --return-child-result The debugger will exist with the same value
3407 the child (debugged) program exited with.
3408 --eval-command COMMAND, -ex COMMAND
3409 Execute a single GDB CLI command. This may be
3410 specified multiple times and in conjunction
3411 with the --command (-x) option.
3413 * Deprecated commands removed
3415 The following commands, that were deprecated in 2000, have been
3419 set|show arm disassembly-flavor set|show arm disassembler
3420 othernames set arm disassembler
3421 set|show remotedebug set|show debug remote
3422 set|show archdebug set|show debug arch
3423 set|show eventdebug set|show debug event
3426 * New BSD user-level threads support
3428 It is now possible to debug programs using the user-level threads
3429 library on OpenBSD and FreeBSD. Currently supported (target)
3432 FreeBSD/amd64 x86_64-*-freebsd*
3433 FreeBSD/i386 i386-*-freebsd*
3434 OpenBSD/i386 i386-*-openbsd*
3436 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3437 are not yet supported.
3439 * New support for Matsushita MN10300 w/sim added
3440 (Work in progress). mn10300-elf.
3442 * REMOVED configurations and files
3444 VxWorks and the XDR protocol *-*-vxworks
3445 Motorola MCORE mcore-*-*
3446 National Semiconductor NS32000 ns32k-*-*
3448 * New "set print array-indexes" command
3450 After turning this setting "on", GDB prints the index of each element
3451 when displaying arrays. The default is "off" to preserve the previous
3454 * VAX floating point support
3456 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3458 * User-defined command support
3460 In addition to using $arg0..$arg9 for argument passing, it is now possible
3461 to use $argc to determine now many arguments have been passed. See the
3462 section on user-defined commands in the user manual for more information.
3464 *** Changes in GDB 6.3:
3466 * New command line option
3468 GDB now accepts -l followed by a number to set the timeout for remote
3471 * GDB works with GCC -feliminate-dwarf2-dups
3473 GDB now supports a more compact representation of DWARF-2 debug
3474 information using DW_FORM_ref_addr references. These are produced
3475 by GCC with the option -feliminate-dwarf2-dups and also by some
3476 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3477 to use -feliminate-dwarf2-dups.
3479 * Internationalization
3481 When supported by the host system, GDB will be built with
3482 internationalization (libintl). The task of marking up the sources is
3483 continued, we're looking forward to our first translation.
3487 Initial support for debugging programs compiled with the GNAT
3488 implementation of the Ada programming language has been integrated
3489 into GDB. In this release, support is limited to expression evaluation.
3491 * New native configurations
3493 GNU/Linux/m32r m32r-*-linux-gnu
3497 GDB's remote protocol now includes support for the 'p' packet. This
3498 packet is used to fetch individual registers from a remote inferior.
3500 * END-OF-LIFE registers[] compatibility module
3502 GDB's internal register infrastructure has been completely rewritten.
3503 The new infrastructure making possible the implementation of key new
3504 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3507 GDB 6.3 will be the last release to include the the registers[]
3508 compatibility module that allowed out-of-date configurations to
3509 continue to work. This change directly impacts the following
3519 powerpc bdm protocol
3521 Unless there is activity to revive these configurations, they will be
3522 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3524 * OBSOLETE configurations and files
3526 Configurations that have been declared obsolete in this release have
3527 been commented out. Unless there is activity to revive these
3528 configurations, the next release of GDB will have their sources
3529 permanently REMOVED.
3538 *** Changes in GDB 6.2.1:
3540 * MIPS `break main; run' gave an heuristic-fence-post warning
3542 When attempting to run even a simple program, a warning about
3543 heuristic-fence-post being hit would be reported. This problem has
3546 * MIPS IRIX 'long double' crashed GDB
3548 When examining a long double variable, GDB would get a segmentation
3549 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3550 IRIX long double values).
3554 A bug in the VAX stack code was causing problems with the "next"
3555 command. This problem has been fixed.
3557 *** Changes in GDB 6.2:
3559 * Fix for ``many threads''
3561 On GNU/Linux systems that use the NPTL threads library, a program
3562 rapidly creating and deleting threads would confuse GDB leading to the
3565 ptrace: No such process.
3566 thread_db_get_info: cannot get thread info: generic error
3568 This problem has been fixed.
3570 * "-async" and "-noasync" options removed.
3572 Support for the broken "-noasync" option has been removed (it caused
3575 * New ``start'' command.
3577 This command runs the program until the begining of the main procedure.
3579 * New BSD Kernel Data Access Library (libkvm) interface
3581 Using ``target kvm'' it is now possible to debug kernel core dumps and
3582 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3583 platforms. Currently supported (native-only) configurations are:
3585 FreeBSD/amd64 x86_64-*-freebsd*
3586 FreeBSD/i386 i?86-*-freebsd*
3587 NetBSD/i386 i?86-*-netbsd*
3588 NetBSD/m68k m68*-*-netbsd*
3589 NetBSD/sparc sparc-*-netbsd*
3590 OpenBSD/amd64 x86_64-*-openbsd*
3591 OpenBSD/i386 i?86-*-openbsd*
3592 OpenBSD/m68k m68*-openbsd*
3593 OpenBSD/sparc sparc-*-openbsd*
3595 * Signal trampoline code overhauled
3597 Many generic problems with GDB's signal handling code have been fixed.
3598 These include: backtraces through non-contiguous stacks; recognition
3599 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3600 call; backtrace through a signal trampoline; step into and out of
3601 signal handlers; and single-stepping in the signal trampoline.
3603 Please note that kernel bugs are a limiting factor here. These
3604 features have been shown to work on an s390 GNU/Linux system that
3605 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3607 * Cygwin support for DWARF 2 added.
3609 * New native configurations
3611 GNU/Linux/hppa hppa*-*-linux*
3612 OpenBSD/hppa hppa*-*-openbsd*
3613 OpenBSD/m68k m68*-*-openbsd*
3614 OpenBSD/m88k m88*-*-openbsd*
3615 OpenBSD/powerpc powerpc-*-openbsd*
3616 NetBSD/vax vax-*-netbsd*
3617 OpenBSD/vax vax-*-openbsd*
3619 * END-OF-LIFE frame compatibility module
3621 GDB's internal frame infrastructure has been completely rewritten.
3622 The new infrastructure making it possible to support key new features
3623 including DWARF 2 Call Frame Information. To aid in the task of
3624 migrating old configurations to this new infrastructure, a
3625 compatibility module, that allowed old configurations to continue to
3626 work, was also included.
3628 GDB 6.2 will be the last release to include this frame compatibility
3629 module. This change directly impacts the following configurations:
3639 Unless there is activity to revive these configurations, they will be
3640 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3642 * REMOVED configurations and files
3644 Sun 3, running SunOS 3 m68*-*-sunos3*
3645 Sun 3, running SunOS 4 m68*-*-sunos4*
3646 Sun 2, running SunOS 3 m68000-*-sunos3*
3647 Sun 2, running SunOS 4 m68000-*-sunos4*
3648 Motorola 680x0 running LynxOS m68*-*-lynxos*
3649 AT&T 3b1/Unix pc m68*-att-*
3650 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3651 decstation mips-dec-* mips-little-*
3652 riscos mips-*-riscos* mips-*-sysv*
3653 sonymips mips-sony-*
3654 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3656 *** Changes in GDB 6.1.1:
3658 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3660 The TUI (Text-mode User Interface) is now built as part of a default
3661 GDB configuration. It is enabled by either selecting the TUI with the
3662 command line option "-i=tui" or by running the separate "gdbtui"
3663 program. For more information on the TUI, see the manual "Debugging
3666 * Pending breakpoint support (also included in GDB 6.1)
3668 Support has been added to allow you to specify breakpoints in shared
3669 libraries that have not yet been loaded. If a breakpoint location
3670 cannot be found, and the "breakpoint pending" option is set to auto,
3671 GDB queries you if you wish to make the breakpoint pending on a future
3672 shared-library load. If and when GDB resolves the breakpoint symbol,
3673 the pending breakpoint is removed as one or more regular breakpoints
3676 Pending breakpoints are very useful for GCJ Java debugging.
3678 * Fixed ISO-C build problems
3680 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3681 non ISO-C code that stopped them being built using a more strict ISO-C
3682 compiler (e.g., IBM's C compiler).
3684 * Fixed build problem on IRIX 5
3686 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3687 wasn't able to compile compile on an IRIX 5 system.
3689 * Added execute permission to gdb/gdbserver/configure
3691 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3692 permission. This bug would cause configure to fail on a number of
3693 systems (Solaris, IRIX). Ref: server/519.
3695 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3697 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3698 has been updated to use constant array sizes.
3700 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3702 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3703 its generated DWARF Call Frame Info. This encoding was causing GDB to
3704 panic, that panic has been fixed. Ref: gdb/1628.
3706 * Fixed a problem when examining parameters in shared library code.
3708 When examining parameters in optimized shared library code generated
3709 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3710 not available''. GDB now correctly displays the variable's value.
3712 *** Changes in GDB 6.1:
3714 * Removed --with-mmalloc
3716 Support for the mmalloc memory manager has been removed, as it
3717 conflicted with the internal gdb byte cache.
3719 * Changes in AMD64 configurations
3721 The AMD64 target now includes the %cs and %ss registers. As a result
3722 the AMD64 remote protocol has changed; this affects the floating-point
3723 and SSE registers. If you rely on those registers for your debugging,
3724 you should upgrade gdbserver on the remote side.
3726 * Revised SPARC target
3728 The SPARC target has been completely revised, incorporating the
3729 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3730 support for LynxOS and SunOS 4 has been dropped. Calling functions
3731 from within GDB on operating systems with a non-executable stack
3732 (Solaris, OpenBSD) now works.
3736 GDB has a new C++ demangler which does a better job on the mangled
3737 names generated by current versions of g++. It also runs faster, so
3738 with this and other changes gdb should now start faster on large C++
3741 * DWARF 2 Location Expressions
3743 GDB support for location expressions has been extended to support function
3744 arguments and frame bases. Older versions of GDB could crash when they
3747 * C++ nested types and namespaces
3749 GDB's support for nested types and namespaces in C++ has been
3750 improved, especially if you use the DWARF 2 debugging format. (This
3751 is the default for recent versions of GCC on most platforms.)
3752 Specifically, if you have a class "Inner" defined within a class or
3753 namespace "Outer", then GDB realizes that the class's name is
3754 "Outer::Inner", not simply "Inner". This should greatly reduce the
3755 frequency of complaints about not finding RTTI symbols. In addition,
3756 if you are stopped at inside of a function defined within a namespace,
3757 GDB modifies its name lookup accordingly.
3759 * New native configurations
3761 NetBSD/amd64 x86_64-*-netbsd*
3762 OpenBSD/amd64 x86_64-*-openbsd*
3763 OpenBSD/alpha alpha*-*-openbsd*
3764 OpenBSD/sparc sparc-*-openbsd*
3765 OpenBSD/sparc64 sparc64-*-openbsd*
3767 * New debugging protocols
3769 M32R with SDI protocol m32r-*-elf*
3771 * "set prompt-escape-char" command deleted.
3773 The command "set prompt-escape-char" has been deleted. This command,
3774 and its very obscure effet on GDB's prompt, was never documented,
3775 tested, nor mentioned in the NEWS file.
3777 * OBSOLETE configurations and files
3779 Configurations that have been declared obsolete in this release have
3780 been commented out. Unless there is activity to revive these
3781 configurations, the next release of GDB will have their sources
3782 permanently REMOVED.
3784 Sun 3, running SunOS 3 m68*-*-sunos3*
3785 Sun 3, running SunOS 4 m68*-*-sunos4*
3786 Sun 2, running SunOS 3 m68000-*-sunos3*
3787 Sun 2, running SunOS 4 m68000-*-sunos4*
3788 Motorola 680x0 running LynxOS m68*-*-lynxos*
3789 AT&T 3b1/Unix pc m68*-att-*
3790 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3791 decstation mips-dec-* mips-little-*
3792 riscos mips-*-riscos* mips-*-sysv*
3793 sonymips mips-sony-*
3794 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3796 * REMOVED configurations and files
3798 SGI Irix-4.x mips-sgi-irix4 or iris4
3799 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3800 Z8000 simulator z8k-zilog-none or z8ksim
3801 Matsushita MN10200 w/simulator mn10200-*-*
3802 H8/500 simulator h8500-hitachi-hms or h8500hms
3803 HP/PA running BSD hppa*-*-bsd*
3804 HP/PA running OSF/1 hppa*-*-osf*
3805 HP/PA Pro target hppa*-*-pro*
3806 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3807 386BSD i[3456]86-*-bsd*
3808 Sequent family i[3456]86-sequent-sysv4*
3809 i[3456]86-sequent-sysv*
3810 i[3456]86-sequent-bsd*
3811 SPARC running LynxOS sparc-*-lynxos*
3812 SPARC running SunOS 4 sparc-*-sunos4*
3813 Tsqware Sparclet sparclet-*-*
3814 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3816 *** Changes in GDB 6.0:
3820 Support for debugging the Objective-C programming language has been
3821 integrated into GDB.
3823 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3825 DWARF 2's Call Frame Information makes available compiler generated
3826 information that more exactly describes the program's run-time stack.
3827 By using this information, GDB is able to provide more robust stack
3830 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3831 have been updated to use a new backtrace mechanism which includes
3832 DWARF 2 CFI support.
3836 GDB's remote protocol has been extended to include support for hosted
3837 file I/O (where the remote target uses GDB's file system). See GDB's
3838 remote protocol documentation for details.
3840 * All targets using the new architecture framework.
3842 All of GDB's targets have been updated to use the new internal
3843 architecture framework. The way is now open for future GDB releases
3844 to include cross-architecture native debugging support (i386 on amd64,
3847 * GNU/Linux's Thread Local Storage (TLS)
3849 GDB now includes support for for the GNU/Linux implementation of
3850 per-thread variables.
3852 * GNU/Linux's Native POSIX Thread Library (NPTL)
3854 GDB's thread code has been updated to work with either the new
3855 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3857 * Separate debug info.
3859 GDB, in conjunction with BINUTILS, now supports a mechanism for
3860 automatically loading debug information from a separate file. Instead
3861 of shipping full debug and non-debug versions of system libraries,
3862 system integrators can now instead ship just the stripped libraries
3863 and optional debug files.
3865 * DWARF 2 Location Expressions
3867 DWARF 2 Location Expressions allow the compiler to more completely
3868 describe the location of variables (even in optimized code) to the
3871 GDB now includes preliminary support for location expressions (support
3872 for DW_OP_piece is still missing).
3876 A number of long standing bugs that caused GDB to die while starting a
3877 Java application have been fixed. GDB's Java support is now
3878 considered "useable".
3880 * GNU/Linux support for fork, vfork, and exec.
3882 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3883 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3886 * GDB supports logging output to a file
3888 There are two new commands, "set logging" and "show logging", which can be
3889 used to capture GDB's output to a file.
3891 * The meaning of "detach" has changed for gdbserver
3893 The "detach" command will now resume the application, as documented. To
3894 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3897 * d10v, m68hc11 `regs' command deprecated
3899 The `info registers' command has been updated so that it displays the
3900 registers using a format identical to the old `regs' command.
3904 A new command, "maint set profile on/off", has been added. This command can
3905 be used to enable or disable profiling while running GDB, to profile a
3906 session or a set of commands. In addition there is a new configure switch,
3907 "--enable-profiling", which will cause GDB to be compiled with profiling
3908 data, for more informative profiling results.
3910 * Default MI syntax changed to "mi2".
3912 The default MI (machine interface) syntax, enabled by the command line
3913 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3914 "mi1", can be enabled by specifying the option "-i=mi1".
3916 Support for the original "mi0" syntax (included in GDB 5.0) has been
3919 Fix for gdb/192: removed extraneous space when displaying frame level.
3920 Fix for gdb/672: update changelist is now output in mi list format.
3921 Fix for gdb/702: a -var-assign that updates the value now shows up
3922 in a subsequent -var-update.
3924 * New native configurations.
3926 FreeBSD/amd64 x86_64-*-freebsd*
3928 * Multi-arched targets.
3930 HP/PA HPUX11 hppa*-*-hpux*
3931 Renesas M32R/D w/simulator m32r-*-elf*
3933 * OBSOLETE configurations and files
3935 Configurations that have been declared obsolete in this release have
3936 been commented out. Unless there is activity to revive these
3937 configurations, the next release of GDB will have their sources
3938 permanently REMOVED.
3940 Z8000 simulator z8k-zilog-none or z8ksim
3941 Matsushita MN10200 w/simulator mn10200-*-*
3942 H8/500 simulator h8500-hitachi-hms or h8500hms
3943 HP/PA running BSD hppa*-*-bsd*
3944 HP/PA running OSF/1 hppa*-*-osf*
3945 HP/PA Pro target hppa*-*-pro*
3946 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3947 Sequent family i[3456]86-sequent-sysv4*
3948 i[3456]86-sequent-sysv*
3949 i[3456]86-sequent-bsd*
3950 Tsqware Sparclet sparclet-*-*
3951 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3953 * REMOVED configurations and files
3956 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3957 IBM AIX PS/2 i[3456]86-*-aix
3958 i386 running Mach 3.0 i[3456]86-*-mach3*
3959 i386 running Mach i[3456]86-*-mach*
3960 i386 running OSF/1 i[3456]86-*osf1mk*
3961 HP/Apollo 68k Family m68*-apollo*-sysv*,
3963 m68*-hp-bsd*, m68*-hp-hpux*
3964 Argonaut Risc Chip (ARC) arc-*-*
3965 Mitsubishi D30V d30v-*-*
3966 Fujitsu FR30 fr30-*-elf*
3967 OS/9000 i[34]86-*-os9k
3968 I960 with MON960 i960-*-coff
3970 * MIPS $fp behavior changed
3972 The convenience variable $fp, for the MIPS, now consistently returns
3973 the address of the current frame's base. Previously, depending on the
3974 context, $fp could refer to either $sp or the current frame's base
3975 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3976 The GNU Source-Level Debugger''.
3978 *** Changes in GDB 5.3:
3980 * GNU/Linux shared library multi-threaded performance improved.
3982 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3983 `/proc', in preference to `ptrace' for memory reads. This may result
3984 in an improvement in the start-up time of multi-threaded, shared
3985 library applications when run under GDB. One GDB user writes: ``loads
3986 shared libs like mad''.
3988 * ``gdbserver'' now supports multi-threaded applications on some targets
3990 Support for debugging multi-threaded applications which use
3991 the GNU/Linux LinuxThreads package has been added for
3992 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3993 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3995 * GDB now supports C/C++ preprocessor macros.
3997 GDB now expands preprocessor macro invocations in C/C++ expressions,
3998 and provides various commands for showing macro definitions and how
4001 The new command `macro expand EXPRESSION' expands any macro
4002 invocations in expression, and shows the result.
4004 The new command `show macro MACRO-NAME' shows the definition of the
4005 macro named MACRO-NAME, and where it was defined.
4007 Most compilers don't include information about macros in the debugging
4008 information by default. In GCC 3.1, for example, you need to compile
4009 your program with the options `-gdwarf-2 -g3'. If the macro
4010 information is present in the executable, GDB will read it.
4012 * Multi-arched targets.
4014 DEC Alpha (partial) alpha*-*-*
4015 DEC VAX (partial) vax-*-*
4017 National Semiconductor NS32000 (partial) ns32k-*-*
4018 Motorola 68000 (partial) m68k-*-*
4019 Motorola MCORE mcore-*-*
4023 Fujitsu FRV architecture added by Red Hat frv*-*-*
4026 * New native configurations
4028 Alpha NetBSD alpha*-*-netbsd*
4029 SH NetBSD sh*-*-netbsdelf*
4030 MIPS NetBSD mips*-*-netbsd*
4031 UltraSPARC NetBSD sparc64-*-netbsd*
4033 * OBSOLETE configurations and files
4035 Configurations that have been declared obsolete in this release have
4036 been commented out. Unless there is activity to revive these
4037 configurations, the next release of GDB will have their sources
4038 permanently REMOVED.
4040 Mitsubishi D30V d30v-*-*
4041 OS/9000 i[34]86-*-os9k
4042 IBM AIX PS/2 i[3456]86-*-aix
4043 Fujitsu FR30 fr30-*-elf*
4044 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4045 Argonaut Risc Chip (ARC) arc-*-*
4046 i386 running Mach 3.0 i[3456]86-*-mach3*
4047 i386 running Mach i[3456]86-*-mach*
4048 i386 running OSF/1 i[3456]86-*osf1mk*
4049 HP/Apollo 68k Family m68*-apollo*-sysv*,
4051 m68*-hp-bsd*, m68*-hp-hpux*
4052 I960 with MON960 i960-*-coff
4054 * OBSOLETE languages
4056 CHILL, a Pascal like language used by telecommunications companies.
4058 * REMOVED configurations and files
4060 AMD 29k family via UDI a29k-amd-udi, udi29k
4061 A29K VxWorks a29k-*-vxworks
4062 AMD 29000 embedded, using EBMON a29k-none-none
4063 AMD 29000 embedded with COFF a29k-none-coff
4064 AMD 29000 embedded with a.out a29k-none-aout
4066 testsuite/gdb.hp/gdb.threads-hp/ directory
4068 * New command "set max-user-call-depth <nnn>"
4070 This command allows the user to limit the call depth of user-defined
4071 commands. The default is 1024.
4073 * Changes in FreeBSD/i386 native debugging.
4075 Support for the "generate-core-file" has been added.
4077 * New commands "dump", "append", and "restore".
4079 These commands allow data to be copied from target memory
4080 to a bfd-format or binary file (dump and append), and back
4081 from a file into memory (restore).
4083 * Improved "next/step" support on multi-processor Alpha Tru64.
4085 The previous single-step mechanism could cause unpredictable problems,
4086 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4087 of a software single-step mechanism prevents this.
4089 *** Changes in GDB 5.2.1:
4097 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4098 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4099 Fix, by Joel Brobecker imported from mainline.
4101 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4102 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4103 Fix, by Fred Fish, imported from mainline.
4105 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4106 Surprisingly enough, it works now.
4107 By Michal Ludvig, imported from mainline.
4109 i386 hardware watchpoint support:
4110 avoid misses on second run for some targets.
4111 By Pierre Muller, imported from mainline.
4113 *** Changes in GDB 5.2:
4115 * New command "set trust-readonly-sections on[off]".
4117 This command is a hint that tells gdb that read-only sections
4118 really are read-only (ie. that their contents will not change).
4119 In this mode, gdb will go to the object file rather than the
4120 target to read memory from read-only sections (such as ".text").
4121 This can be a significant performance improvement on some
4122 (notably embedded) targets.
4124 * New command "generate-core-file" (or "gcore").
4126 This new gdb command allows the user to drop a core file of the child
4127 process state at any time. So far it's been implemented only for
4128 GNU/Linux and Solaris, but should be relatively easily ported to other
4129 hosts. Argument is core file name (defaults to core.<pid>).
4131 * New command line option
4133 GDB now accepts --pid or -p followed by a process id.
4135 * Change in command line behavior -- corefiles vs. process ids.
4137 There is a subtle behavior in the way in which GDB handles
4138 command line arguments. The first non-flag argument is always
4139 a program to debug, but the second non-flag argument may either
4140 be a corefile or a process id. Previously, GDB would attempt to
4141 open the second argument as a corefile, and if that failed, would
4142 issue a superfluous error message and then attempt to attach it as
4143 a process. Now, if the second argument begins with a non-digit,
4144 it will be treated as a corefile. If it begins with a digit,
4145 GDB will attempt to attach it as a process, and if no such process
4146 is found, will then attempt to open it as a corefile.
4148 * Changes in ARM configurations.
4150 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4151 configuration is fully multi-arch.
4153 * New native configurations
4155 ARM NetBSD arm*-*-netbsd*
4156 x86 OpenBSD i[3456]86-*-openbsd*
4157 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4158 Sparc64 running FreeBSD sparc64-*-freebsd*
4162 Sanyo XStormy16 xstormy16-elf
4164 * OBSOLETE configurations and files
4166 Configurations that have been declared obsolete in this release have
4167 been commented out. Unless there is activity to revive these
4168 configurations, the next release of GDB will have their sources
4169 permanently REMOVED.
4171 AMD 29k family via UDI a29k-amd-udi, udi29k
4172 A29K VxWorks a29k-*-vxworks
4173 AMD 29000 embedded, using EBMON a29k-none-none
4174 AMD 29000 embedded with COFF a29k-none-coff
4175 AMD 29000 embedded with a.out a29k-none-aout
4177 testsuite/gdb.hp/gdb.threads-hp/ directory
4179 * REMOVED configurations and files
4181 TI TMS320C80 tic80-*-*
4183 PowerPC Solaris powerpcle-*-solaris*
4184 PowerPC Windows NT powerpcle-*-cygwin32
4185 PowerPC Netware powerpc-*-netware*
4186 Harris/CXUX m88k m88*-harris-cxux*
4187 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4188 ns32k-utek-sysv* ns32k-utek-*
4189 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4190 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4191 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4192 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4193 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4195 * Changes to command line processing
4197 The new `--args' feature can be used to specify command-line arguments
4198 for the inferior from gdb's command line.
4200 * Changes to key bindings
4202 There is a new `operate-and-get-next' function bound to `C-o'.
4204 *** Changes in GDB 5.1.1
4206 Fix compile problem on DJGPP.
4208 Fix a problem with floating-point registers on the i386 being
4211 Fix to stop GDB crashing on .debug_str debug info.
4213 Numerous documentation fixes.
4215 Numerous testsuite fixes.
4217 *** Changes in GDB 5.1:
4219 * New native configurations
4221 Alpha FreeBSD alpha*-*-freebsd*
4222 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4223 MIPS GNU/Linux mips*-*-linux*
4224 MIPS SGI Irix 6.x mips*-sgi-irix6*
4225 ia64 AIX ia64-*-aix*
4226 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4230 Motorola 68HC11 and 68HC12 m68hc11-elf
4232 UltraSparc running GNU/Linux sparc64-*-linux*
4234 * OBSOLETE configurations and files
4236 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4237 Harris/CXUX m88k m88*-harris-cxux*
4238 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4239 ns32k-utek-sysv* ns32k-utek-*
4240 TI TMS320C80 tic80-*-*
4242 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4243 PowerPC Solaris powerpcle-*-solaris*
4244 PowerPC Windows NT powerpcle-*-cygwin32
4245 PowerPC Netware powerpc-*-netware*
4246 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4247 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4248 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4249 Apple Macintosh (MPW) host N/A
4251 stuff.c (Program to stuff files into a specially prepared space in kdb)
4252 kdb-start.c (Main loop for the standalone kernel debugger)
4254 Configurations that have been declared obsolete in this release have
4255 been commented out. Unless there is activity to revive these
4256 configurations, the next release of GDB will have their sources
4257 permanently REMOVED.
4259 * REMOVED configurations and files
4261 Altos 3068 m68*-altos-*
4262 Convex c1-*-*, c2-*-*
4264 ARM RISCix arm-*-* (as host)
4268 * GDB has been converted to ISO C.
4270 GDB's source code has been converted to ISO C. In particular, the
4271 sources are fully protoized, and rely on standard headers being
4276 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4278 * The MI enabled by default.
4280 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4281 revised and enabled by default. Packages which use GDB as a debugging
4282 engine behind a UI or another front end are encouraged to switch to
4283 using the GDB/MI interface, instead of the old annotations interface
4284 which is now deprecated.
4286 * Support for debugging Pascal programs.
4288 GDB now includes support for debugging Pascal programs. The following
4289 main features are supported:
4291 - Pascal-specific data types such as sets;
4293 - automatic recognition of Pascal sources based on file-name
4296 - Pascal-style display of data types, variables, and functions;
4298 - a Pascal expression parser.
4300 However, some important features are not yet supported.
4302 - Pascal string operations are not supported at all;
4304 - there are some problems with boolean types;
4306 - Pascal type hexadecimal constants are not supported
4307 because they conflict with the internal variables format;
4309 - support for Pascal objects and classes is not full yet;
4311 - unlike Pascal, GDB is case-sensitive for symbol names.
4313 * Changes in completion.
4315 Commands such as `shell', `run' and `set args', which pass arguments
4316 to inferior programs, now complete on file names, similar to what
4317 users expect at the shell prompt.
4319 Commands which accept locations, such as `disassemble', `print',
4320 `breakpoint', `until', etc. now complete on filenames as well as
4321 program symbols. Thus, if you type "break foob TAB", and the source
4322 files linked into the programs include `foobar.c', that file name will
4323 be one of the candidates for completion. However, file names are not
4324 considered for completion after you typed a colon that delimits a file
4325 name from a name of a function in that file, as in "break foo.c:bar".
4327 `set demangle-style' completes on available demangling styles.
4329 * New platform-independent commands:
4331 It is now possible to define a post-hook for a command as well as a
4332 hook that runs before the command. For more details, see the
4333 documentation of `hookpost' in the GDB manual.
4335 * Changes in GNU/Linux native debugging.
4337 Support for debugging multi-threaded programs has been completely
4338 revised for all platforms except m68k and sparc. You can now debug as
4339 many threads as your system allows you to have.
4341 Attach/detach is supported for multi-threaded programs.
4343 Support for SSE registers was added for x86. This doesn't work for
4344 multi-threaded programs though.
4346 * Changes in MIPS configurations.
4348 Multi-arch support is enabled for all MIPS configurations.
4350 GDB can now be built as native debugger on SGI Irix 6.x systems for
4351 debugging n32 executables. (Debugging 64-bit executables is not yet
4354 * Unified support for hardware watchpoints in all x86 configurations.
4356 Most (if not all) native x86 configurations support hardware-assisted
4357 breakpoints and watchpoints in a unified manner. This support
4358 implements debug register sharing between watchpoints, which allows to
4359 put a virtually infinite number of watchpoints on the same address,
4360 and also supports watching regions up to 16 bytes with several debug
4363 The new maintenance command `maintenance show-debug-regs' toggles
4364 debugging print-outs in functions that insert, remove, and test
4365 watchpoints and hardware breakpoints.
4367 * Changes in the DJGPP native configuration.
4369 New command ``info dos sysinfo'' displays assorted information about
4370 the CPU, OS, memory, and DPMI server.
4372 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4373 display information about segment descriptors stored in GDT, LDT, and
4376 New commands ``info dos pde'' and ``info dos pte'' display entries
4377 from Page Directory and Page Tables (for now works with CWSDPMI only).
4378 New command ``info dos address-pte'' displays the Page Table entry for
4379 a given linear address.
4381 GDB can now pass command lines longer than 126 characters to the
4382 program being debugged (requires an update to the libdbg.a library
4383 which is part of the DJGPP development kit).
4385 DWARF2 debug info is now supported.
4387 It is now possible to `step' and `next' through calls to `longjmp'.
4389 * Changes in documentation.
4391 All GDB documentation was converted to GFDL, the GNU Free
4392 Documentation License.
4394 Tracepoints-related commands are now fully documented in the GDB
4397 TUI, the Text-mode User Interface, is now documented in the manual.
4399 Tracepoints-related commands are now fully documented in the GDB
4402 The "GDB Internals" manual now has an index. It also includes
4403 documentation of `ui_out' functions, GDB coding standards, x86
4404 hardware watchpoints, and memory region attributes.
4406 * GDB's version number moved to ``version.in''
4408 The Makefile variable VERSION has been replaced by the file
4409 ``version.in''. People creating GDB distributions should update the
4410 contents of this file.
4414 GUD support is now a standard part of the EMACS distribution.
4416 *** Changes in GDB 5.0:
4418 * Improved support for debugging FP programs on x86 targets
4420 Unified and much-improved support for debugging floating-point
4421 programs on all x86 targets. In particular, ``info float'' now
4422 displays the FP registers in the same format on all x86 targets, with
4423 greater level of detail.
4425 * Improvements and bugfixes in hardware-assisted watchpoints
4427 It is now possible to watch array elements, struct members, and
4428 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4429 on x86 targets no longer erroneously trigger when the address is
4432 * Improvements in the native DJGPP version of GDB
4434 The distribution now includes all the scripts and auxiliary files
4435 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4436 machines ``out of the box''.
4438 The DJGPP version can now debug programs that use signals. It is
4439 possible to catch signals that happened in the debuggee, deliver
4440 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4441 would kill the program being debugged.) Programs that hook hardware
4442 interrupts (keyboard, timer, etc.) can also be debugged.
4444 It is now possible to debug DJGPP programs that redirect their
4445 standard handles or switch them to raw (as opposed to cooked) mode, or
4446 even close them. The command ``run < foo > bar'' works as expected,
4447 and ``info terminal'' reports useful information about the debuggee's
4448 terminal, including raw/cooked mode, redirection, etc.
4450 The DJGPP version now uses termios functions for console I/O, which
4451 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4454 DOS-style file names with drive letters are now fully supported by
4457 It is now possible to debug DJGPP programs that switch their working
4458 directory. It is also possible to rerun the debuggee any number of
4459 times without restarting GDB; thus, you can use the same setup,
4460 breakpoints, etc. for many debugging sessions.
4462 * New native configurations
4464 ARM GNU/Linux arm*-*-linux*
4465 PowerPC GNU/Linux powerpc-*-linux*
4469 Motorola MCore mcore-*-*
4470 x86 VxWorks i[3456]86-*-vxworks*
4471 PowerPC VxWorks powerpc-*-vxworks*
4472 TI TMS320C80 tic80-*-*
4474 * OBSOLETE configurations
4476 Altos 3068 m68*-altos-*
4477 Convex c1-*-*, c2-*-*
4479 ARM RISCix arm-*-* (as host)
4482 Configurations that have been declared obsolete will be commented out,
4483 but the code will be left in place. If there is no activity to revive
4484 these configurations before the next release of GDB, the sources will
4485 be permanently REMOVED.
4487 * Gould support removed
4489 Support for the Gould PowerNode and NP1 has been removed.
4491 * New features for SVR4
4493 On SVR4 native platforms (such as Solaris), if you attach to a process
4494 without first loading a symbol file, GDB will now attempt to locate and
4495 load symbols from the running process's executable file.
4497 * Many C++ enhancements
4499 C++ support has been greatly improved. Overload resolution now works properly
4500 in almost all cases. RTTI support is on the way.
4502 * Remote targets can connect to a sub-program
4504 A popen(3) style serial-device has been added. This device starts a
4505 sub-process (such as a stand-alone simulator) and then communicates
4506 with that. The sub-program to run is specified using the syntax
4507 ``|<program> <args>'' vis:
4509 (gdb) set remotedebug 1
4510 (gdb) target extended-remote |mn10300-elf-sim program-args
4512 * MIPS 64 remote protocol
4514 A long standing bug in the mips64 remote protocol where by GDB
4515 expected certain 32 bit registers (ex SR) to be transfered as 32
4516 instead of 64 bits has been fixed.
4518 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4519 added to provide backward compatibility with older versions of GDB.
4521 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4523 The command ``set remotebinarydownload'' command has been replaced by
4524 ``set remote X-packet''. Other commands in ``set remote'' family
4525 include ``set remote P-packet''.
4527 * Breakpoint commands accept ranges.
4529 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4530 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4531 ``tracepoint passcount'' also accepts a range of tracepoints.
4533 * ``apropos'' command added.
4535 The ``apropos'' command searches through command names and
4536 documentation strings, printing out matches, making it much easier to
4537 try to find a command that does what you are looking for.
4541 A new machine oriented interface (MI) has been added to GDB. This
4542 interface is designed for debug environments running GDB as a separate
4543 process. This is part of the long term libGDB project. See the
4544 "GDB/MI" chapter of the GDB manual for further information. It can be
4545 enabled by configuring with:
4547 .../configure --enable-gdbmi
4549 *** Changes in GDB-4.18:
4551 * New native configurations
4553 HP-UX 10.20 hppa*-*-hpux10.20
4554 HP-UX 11.x hppa*-*-hpux11.0*
4555 M68K GNU/Linux m68*-*-linux*
4559 Fujitsu FR30 fr30-*-elf*
4560 Intel StrongARM strongarm-*-*
4561 Mitsubishi D30V d30v-*-*
4563 * OBSOLETE configurations
4565 Gould PowerNode, NP1 np1-*-*, pn-*-*
4567 Configurations that have been declared obsolete will be commented out,
4568 but the code will be left in place. If there is no activity to revive
4569 these configurations before the next release of GDB, the sources will
4570 be permanently REMOVED.
4574 As a compatibility experiment, GDB's source files buildsym.h and
4575 buildsym.c have been converted to pure standard C, no longer
4576 containing any K&R compatibility code. We believe that all systems in
4577 use today either come with a standard C compiler, or have a GCC port
4578 available. If this is not true, please report the affected
4579 configuration to bug-gdb@gnu.org immediately. See the README file for
4580 information about getting a standard C compiler if you don't have one
4585 GDB now uses readline 2.2.
4587 * set extension-language
4589 You can now control the mapping between filename extensions and source
4590 languages by using the `set extension-language' command. For instance,
4591 you can ask GDB to treat .c files as C++ by saying
4592 set extension-language .c c++
4593 The command `info extensions' lists all of the recognized extensions
4594 and their associated languages.
4596 * Setting processor type for PowerPC and RS/6000
4598 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4599 you can use the `set processor' command to specify what variant of the
4600 PowerPC family you are debugging. The command
4604 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4605 following PowerPC and RS6000 variants:
4607 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4608 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4610 403GC IBM PowerPC 403GC
4611 505 Motorola PowerPC 505
4612 860 Motorola PowerPC 860 or 850
4613 601 Motorola PowerPC 601
4614 602 Motorola PowerPC 602
4615 603 Motorola/IBM PowerPC 603 or 603e
4616 604 Motorola PowerPC 604 or 604e
4617 750 Motorola/IBM PowerPC 750 or 750
4619 At the moment, this command just tells GDB what to name the
4620 special-purpose processor registers. Since almost all the affected
4621 registers are inaccessible to user-level programs, this command is
4622 only useful for remote debugging in its present form.
4626 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4627 more extensive support for HP-UX. Added features include shared
4628 library support, kernel threads and hardware watchpoints for 11.00,
4629 support for HP's ANSI C and C++ compilers, and a compatibility mode
4630 for xdb and dbx commands.
4634 HP's donation includes the new concept of catchpoints, which is a
4635 generalization of the old catch command. On HP-UX, it is now possible
4636 to catch exec, fork, and vfork, as well as library loading.
4638 This means that the existing catch command has changed; its first
4639 argument now specifies the type of catch to be set up. See the
4640 output of "help catch" for a list of catchpoint types.
4642 * Debugging across forks
4644 On HP-UX, you can choose which process to debug when a fork() happens
4649 HP has donated a curses-based terminal user interface (TUI). To get
4650 it, build with --enable-tui. Although this can be enabled for any
4651 configuration, at present it only works for native HP debugging.
4653 * GDB remote protocol additions
4655 A new protocol packet 'X' that writes binary data is now available.
4656 Default behavior is to try 'X', then drop back to 'M' if the stub
4657 fails to respond. The settable variable `remotebinarydownload'
4658 allows explicit control over the use of 'X'.
4660 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4661 full 64-bit address. The command
4663 set remoteaddresssize 32
4665 can be used to revert to the old behaviour. For existing remote stubs
4666 the change should not be noticed, as the additional address information
4669 In order to assist in debugging stubs, you may use the maintenance
4670 command `packet' to send any text string to the stub. For instance,
4672 maint packet heythere
4674 sends the packet "$heythere#<checksum>". Note that it is very easy to
4675 disrupt a debugging session by sending the wrong packet at the wrong
4678 The compare-sections command allows you to compare section data on the
4679 target to what is in the executable file without uploading or
4680 downloading, by comparing CRC checksums.
4682 * Tracing can collect general expressions
4684 You may now collect general expressions at tracepoints. This requires
4685 further additions to the target-side stub; see tracepoint.c and
4686 doc/agentexpr.texi for further details.
4688 * mask-address variable for Mips
4690 For Mips targets, you may control the zeroing of the upper 32 bits of
4691 a 64-bit address by entering `set mask-address on'. This is mainly
4692 of interest to users of embedded R4xxx and R5xxx processors.
4694 * Higher serial baud rates
4696 GDB's serial code now allows you to specify baud rates 57600, 115200,
4697 230400, and 460800 baud. (Note that your host system may not be able
4698 to achieve all of these rates.)
4702 The i960 configuration now includes an initial implementation of a
4703 builtin simulator, contributed by Jim Wilson.
4706 *** Changes in GDB-4.17:
4708 * New native configurations
4710 Alpha GNU/Linux alpha*-*-linux*
4711 Unixware 2.x i[3456]86-unixware2*
4712 Irix 6.x mips*-sgi-irix6*
4713 PowerPC GNU/Linux powerpc-*-linux*
4714 PowerPC Solaris powerpcle-*-solaris*
4715 Sparc GNU/Linux sparc-*-linux*
4716 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4720 Argonaut Risc Chip (ARC) arc-*-*
4721 Hitachi H8/300S h8300*-*-*
4722 Matsushita MN10200 w/simulator mn10200-*-*
4723 Matsushita MN10300 w/simulator mn10300-*-*
4724 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4725 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4726 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4727 Mitsubishi D10V w/simulator d10v-*-*
4728 Mitsubishi M32R/D w/simulator m32r-*-elf*
4729 Tsqware Sparclet sparclet-*-*
4730 NEC V850 w/simulator v850-*-*
4732 * New debugging protocols
4734 ARM with RDI protocol arm*-*-*
4735 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4736 DDB and LSI variants of PMON protocol mips*-*-*
4737 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4738 PowerPC with SDS protocol powerpc{,le}-*-eabi
4739 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4743 All configurations can now understand and use the DWARF 2 debugging
4744 format. The choice is automatic, if the symbol file contains DWARF 2
4749 GDB now includes basic Java language support. This support is
4750 only useful with Java compilers that produce native machine code.
4752 * solib-absolute-prefix and solib-search-path
4754 For SunOS and SVR4 shared libraries, you may now set the prefix for
4755 loading absolute shared library symbol files, and the search path for
4756 locating non-absolute shared library symbol files.
4758 * Live range splitting
4760 GDB can now effectively debug code for which GCC has performed live
4761 range splitting as part of its optimization. See gdb/doc/LRS for
4762 more details on the expected format of the stabs information.
4766 GDB's support for the GNU Hurd, including thread debugging, has been
4767 updated to work with current versions of the Hurd.
4771 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4772 instruction set. ARM GDB automatically detects when Thumb
4773 instructions are in use, and adjusts disassembly and backtracing
4778 GDB's MIPS target configurations now handle the MIP16 16-bit
4783 GDB now includes support for overlays; if an executable has been
4784 linked such that multiple sections are based at the same address, GDB
4785 will decide which section to use for symbolic info. You can choose to
4786 control the decision manually, using overlay commands, or implement
4787 additional target-side support and use "overlay load-target" to bring
4788 in the overlay mapping. Do "help overlay" for more detail.
4792 The command "info symbol <address>" displays information about
4793 the symbol at the specified address.
4797 The standard remote protocol now includes an extension that allows
4798 asynchronous collection and display of trace data. This requires
4799 extensive support in the target-side debugging stub. Tracing mode
4800 includes a new interaction mode in GDB and new commands: see the
4801 file tracepoint.c for more details.
4805 Configurations for embedded MIPS now include a simulator contributed
4806 by Cygnus Solutions. The simulator supports the instruction sets
4807 of most MIPS variants.
4811 Sparc configurations may now include the ERC32 simulator contributed
4812 by the European Space Agency. The simulator is not built into
4813 Sparc targets by default; configure with --enable-sim to include it.
4817 For target configurations that may include multiple variants of a
4818 basic architecture (such as MIPS and SH), you may now set the
4819 architecture explicitly. "set arch" sets, "info arch" lists
4820 the possible architectures.
4822 *** Changes in GDB-4.16:
4824 * New native configurations
4826 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4827 M68K NetBSD m68k-*-netbsd*
4828 PowerPC AIX 4.x powerpc-*-aix*
4829 PowerPC MacOS powerpc-*-macos*
4830 PowerPC Windows NT powerpcle-*-cygwin32
4831 RS/6000 AIX 4.x rs6000-*-aix4*
4835 ARM with RDP protocol arm-*-*
4836 I960 with MON960 i960-*-coff
4837 MIPS VxWorks mips*-*-vxworks*
4838 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4839 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4841 Matra Sparclet sparclet-*-*
4845 The powerpc-eabi configuration now includes the PSIM simulator,
4846 contributed by Andrew Cagney, with assistance from Mike Meissner.
4847 PSIM is a very elaborate model of the PowerPC, including not only
4848 basic instruction set execution, but also details of execution unit
4849 performance and I/O hardware. See sim/ppc/README for more details.
4853 GDB now works with Solaris 2.5.
4855 * Windows 95/NT native
4857 GDB will now work as a native debugger on Windows 95 and Windows NT.
4858 To build it from source, you must use the "gnu-win32" environment,
4859 which uses a DLL to emulate enough of Unix to run the GNU tools.
4860 Further information, binaries, and sources are available at
4861 ftp.cygnus.com, under pub/gnu-win32.
4863 * dont-repeat command
4865 If a user-defined command includes the command `dont-repeat', then the
4866 command will not be repeated if the user just types return. This is
4867 useful if the command is time-consuming to run, so that accidental
4868 extra keystrokes don't run the same command many times.
4870 * Send break instead of ^C
4872 The standard remote protocol now includes an option to send a break
4873 rather than a ^C to the target in order to interrupt it. By default,
4874 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4876 * Remote protocol timeout
4878 The standard remote protocol includes a new variable `remotetimeout'
4879 that allows you to set the number of seconds before GDB gives up trying
4880 to read from the target. The default value is 2.
4882 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4884 By default GDB will automatically keep track of objects as they are
4885 loaded and unloaded by the dynamic linker. By using the command `set
4886 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4887 when shared library events occur, thus allowing you to set breakpoints
4888 in shared libraries which are explicitly loaded by the inferior.
4890 Note this feature does not work on hpux8. On hpux9 you must link
4891 /usr/lib/end.o into your program. This feature should work
4892 automatically on hpux10.
4894 * Irix 5.x hardware watchpoint support
4896 Irix 5 configurations now support the use of hardware watchpoints.
4898 * Mips protocol "SYN garbage limit"
4900 When debugging a Mips target using the `target mips' protocol, you
4901 may set the number of characters that GDB will ignore by setting
4902 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4903 every character. The default value is 1050.
4905 * Recording and replaying remote debug sessions
4907 If you set `remotelogfile' to the name of a file, gdb will write to it
4908 a recording of a remote debug session. This recording may then be
4909 replayed back to gdb using "gdbreplay". See gdbserver/README for
4910 details. This is useful when you have a problem with GDB while doing
4911 remote debugging; you can make a recording of the session and send it
4912 to someone else, who can then recreate the problem.
4914 * Speedups for remote debugging
4916 GDB includes speedups for downloading and stepping MIPS systems using
4917 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4918 and more efficient S-record downloading.
4920 * Memory use reductions and statistics collection
4922 GDB now uses less memory and reports statistics about memory usage.
4923 Try the `maint print statistics' command, for example.
4925 *** Changes in GDB-4.15:
4927 * Psymtabs for XCOFF
4929 The symbol reader for AIX GDB now uses partial symbol tables. This
4930 can greatly improve startup time, especially for large executables.
4932 * Remote targets use caching
4934 Remote targets now use a data cache to speed up communication with the
4935 remote side. The data cache could lead to incorrect results because
4936 it doesn't know about volatile variables, thus making it impossible to
4937 debug targets which use memory mapped I/O devices. `set remotecache
4938 off' turns the the data cache off.
4940 * Remote targets may have threads
4942 The standard remote protocol now includes support for multiple threads
4943 in the target system, using new protocol commands 'H' and 'T'. See
4944 gdb/remote.c for details.
4948 If GDB is configured with `--enable-netrom', then it will include
4949 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4950 acts as though it is a bank of ROM on the target board, but you can
4951 write into it over the network. GDB's support consists only of
4952 support for fast loading into the emulated ROM; to debug, you must use
4953 another protocol, such as standard remote protocol. The usual
4954 sequence is something like
4956 target nrom <netrom-hostname>
4958 target remote <netrom-hostname>:1235
4962 GDB now includes support for the Apple Macintosh, as a host only. It
4963 may be run as either an MPW tool or as a standalone application, and
4964 it can debug through the serial port. All the usual GDB commands are
4965 available, but to the target command, you must supply "serial" as the
4966 device type instead of "/dev/ttyXX". See mpw-README in the main
4967 directory for more information on how to build. The MPW configuration
4968 scripts */mpw-config.in support only a few targets, and only the
4969 mips-idt-ecoff target has been tested.
4973 GDB configuration now uses autoconf. This is not user-visible,
4974 but does simplify configuration and building.
4978 GDB now supports hpux10.
4980 *** Changes in GDB-4.14:
4982 * New native configurations
4984 x86 FreeBSD i[345]86-*-freebsd
4985 x86 NetBSD i[345]86-*-netbsd
4986 NS32k NetBSD ns32k-*-netbsd
4987 Sparc NetBSD sparc-*-netbsd
4991 A29K VxWorks a29k-*-vxworks
4992 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4993 CPU32 EST-300 emulator m68*-*-est*
4994 PowerPC ELF powerpc-*-elf
4997 * Alpha OSF/1 support for procfs
4999 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5000 possible to attach to running processes. As the mounting of the /proc
5001 filesystem is optional on the Alpha, GDB automatically determines
5002 the availability of /proc during startup. This can lead to problems
5003 if /proc is unmounted after GDB has been started.
5005 * Arguments to user-defined commands
5007 User commands may accept up to 10 arguments separated by whitespace.
5008 Arguments are accessed within the user command via $arg0..$arg9. A
5011 print $arg0 + $arg1 + $arg2
5013 To execute the command use:
5016 Defines the command "adder" which prints the sum of its three arguments.
5017 Note the arguments are text substitutions, so they may reference variables,
5018 use complex expressions, or even perform inferior function calls.
5020 * New `if' and `while' commands
5022 This makes it possible to write more sophisticated user-defined
5023 commands. Both commands take a single argument, which is the
5024 expression to evaluate, and must be followed by the commands to
5025 execute, one per line, if the expression is nonzero, the list being
5026 terminated by the word `end'. The `if' command list may include an
5027 `else' word, which causes the following commands to be executed only
5028 if the expression is zero.
5030 * Fortran source language mode
5032 GDB now includes partial support for Fortran 77. It will recognize
5033 Fortran programs and can evaluate a subset of Fortran expressions, but
5034 variables and functions may not be handled correctly. GDB will work
5035 with G77, but does not yet know much about symbols emitted by other
5038 * Better HPUX support
5040 Most debugging facilities now work on dynamic executables for HPPAs
5041 running hpux9 or later. You can attach to running dynamically linked
5042 processes, but by default the dynamic libraries will be read-only, so
5043 for instance you won't be able to put breakpoints in them. To change
5044 that behavior do the following before running the program:
5050 This will cause the libraries to be mapped private and read-write.
5051 To revert to the normal behavior, do this:
5057 You cannot set breakpoints or examine data in the library until after
5058 the library is loaded if the function/data symbols do not have
5061 GDB can now also read debug symbols produced by the HP C compiler on
5062 HPPAs (sorry, no C++, Fortran or 68k support).
5064 * Target byte order now dynamically selectable
5066 You can choose which byte order to use with a target system, via the
5067 commands "set endian big" and "set endian little", and you can see the
5068 current setting by using "show endian". You can also give the command
5069 "set endian auto", in which case GDB will use the byte order
5070 associated with the executable. Currently, only embedded MIPS
5071 configurations support dynamic selection of target byte order.
5073 * New DOS host serial code
5075 This version uses DPMI interrupts to handle buffered I/O, so you
5076 no longer need to run asynctsr when debugging boards connected to
5079 *** Changes in GDB-4.13:
5081 * New "complete" command
5083 This lists all the possible completions for the rest of the line, if it
5084 were to be given as a command itself. This is intended for use by emacs.
5086 * Trailing space optional in prompt
5088 "set prompt" no longer adds a space for you after the prompt you set. This
5089 allows you to set a prompt which ends in a space or one that does not.
5091 * Breakpoint hit counts
5093 "info break" now displays a count of the number of times the breakpoint
5094 has been hit. This is especially useful in conjunction with "ignore"; you
5095 can ignore a large number of breakpoint hits, look at the breakpoint info
5096 to see how many times the breakpoint was hit, then run again, ignoring one
5097 less than that number, and this will get you quickly to the last hit of
5100 * Ability to stop printing at NULL character
5102 "set print null-stop" will cause GDB to stop printing the characters of
5103 an array when the first NULL is encountered. This is useful when large
5104 arrays actually contain only short strings.
5106 * Shared library breakpoints
5108 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5109 breakpoints in shared libraries before the executable is run.
5111 * Hardware watchpoints
5113 There is a new hardware breakpoint for the watch command for sparclite
5114 targets. See gdb/sparclite/hw_breakpoint.note.
5116 Hardware watchpoints are also now supported under GNU/Linux.
5120 Annotations have been added. These are for use with graphical interfaces,
5121 and are still experimental. Currently only gdba.el uses these.
5123 * Improved Irix 5 support
5125 GDB now works properly with Irix 5.2.
5127 * Improved HPPA support
5129 GDB now works properly with the latest GCC and GAS.
5131 * New native configurations
5133 Sequent PTX4 i[34]86-sequent-ptx4
5134 HPPA running OSF/1 hppa*-*-osf*
5135 Atari TT running SVR4 m68*-*-sysv4*
5136 RS/6000 LynxOS rs6000-*-lynxos*
5140 OS/9000 i[34]86-*-os9k
5141 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5144 * Hitachi SH7000 and E7000-PC ICE support
5146 There is now support for communicating with the Hitachi E7000-PC ICE.
5147 This is available automatically when GDB is configured for the SH.
5151 As usual, a variety of small fixes and improvements, both generic
5152 and configuration-specific. See the ChangeLog for more detail.
5154 *** Changes in GDB-4.12:
5156 * Irix 5 is now supported
5160 GDB-4.12 on the HPPA has a number of changes which make it unable
5161 to debug the output from the currently released versions of GCC and
5162 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5163 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5164 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5167 *** Changes in GDB-4.11:
5169 * User visible changes:
5173 The "set remotedebug" option is now consistent between the mips remote
5174 target, remote targets using the gdb-specific protocol, UDI (AMD's
5175 debug protocol for the 29k) and the 88k bug monitor. It is now an
5176 integer specifying a debug level (normally 0 or 1, but 2 means more
5177 debugging info for the mips target).
5179 * DEC Alpha native support
5181 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5182 debug info, but GDB works fairly well with the DEC compiler and should
5183 work with a future GCC release. See the README file for a few
5184 Alpha-specific notes.
5186 * Preliminary thread implementation
5188 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5190 * LynxOS native and target support for 386
5192 This release has been hosted on LynxOS 2.2, and also can be configured
5193 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5196 * Improvements in C++ mangling/demangling.
5198 This release has much better g++ debugging, specifically in name
5199 mangling/demangling, virtual function calls, print virtual table,
5200 call methods, ...etc.
5202 *** Changes in GDB-4.10:
5204 * User visible changes:
5206 Remote debugging using the GDB-specific (`target remote') protocol now
5207 supports the `load' command. This is only useful if you have some
5208 other way of getting the stub to the target system, and you can put it
5209 somewhere in memory where it won't get clobbered by the download.
5211 Filename completion now works.
5213 When run under emacs mode, the "info line" command now causes the
5214 arrow to point to the line specified. Also, "info line" prints
5215 addresses in symbolic form (as well as hex).
5217 All vxworks based targets now support a user settable option, called
5218 vxworks-timeout. This option represents the number of seconds gdb
5219 should wait for responses to rpc's. You might want to use this if
5220 your vxworks target is, perhaps, a slow software simulator or happens
5221 to be on the far side of a thin network line.
5225 This release contains support for using a DEC alpha as a GDB host for
5226 cross debugging. Native alpha debugging is not supported yet.
5229 *** Changes in GDB-4.9:
5233 This is the first GDB release which is accompanied by a matching testsuite.
5234 The testsuite requires installation of dejagnu, which should be available
5235 via ftp from most sites that carry GNU software.
5239 'Cfront' style demangling has had its name changed to 'ARM' style, to
5240 emphasize that it was written from the specifications in the C++ Annotated
5241 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5242 disclaimers, it still generated too much confusion with users attempting to
5243 use gdb with AT&T cfront.
5247 GDB now uses a standard remote interface to a simulator library.
5248 So far, the library contains simulators for the Zilog Z8001/2, the
5249 Hitachi H8/300, H8/500 and Super-H.
5251 * New targets supported
5253 H8/300 simulator h8300-hitachi-hms or h8300hms
5254 H8/500 simulator h8500-hitachi-hms or h8500hms
5255 SH simulator sh-hitachi-hms or sh
5256 Z8000 simulator z8k-zilog-none or z8ksim
5257 IDT MIPS board over serial line mips-idt-ecoff
5259 Cross-debugging to GO32 targets is supported. It requires a custom
5260 version of the i386-stub.c module which is integrated with the
5261 GO32 memory extender.
5263 * New remote protocols
5265 MIPS remote debugging protocol.
5267 * New source languages supported
5269 This version includes preliminary support for Chill, a Pascal like language
5270 used by telecommunications companies. Chill support is also being integrated
5271 into the GNU compiler, but we don't know when it will be publically available.
5274 *** Changes in GDB-4.8:
5276 * HP Precision Architecture supported
5278 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5279 version of this support was available as a set of patches from the
5280 University of Utah. GDB does not support debugging of programs
5281 compiled with the HP compiler, because HP will not document their file
5282 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5283 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5285 Many problems in the preliminary version have been fixed.
5287 * Faster and better demangling
5289 We have improved template demangling and fixed numerous bugs in the GNU style
5290 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5291 character types (wchar_t) are now supported. Demangling of each symbol is now
5292 only done once, and is cached when the symbol table for a file is read in.
5293 This results in a small increase in memory usage for C programs, a moderate
5294 increase in memory usage for C++ programs, and a fantastic speedup in
5297 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5298 from the specifications in the Annotated Reference Manual, which AT&T's
5299 compiler does not actually implement.
5301 * G++ multiple inheritance compiler problem
5303 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5304 inheritance lattices was reworked to properly discover ambiguities. We
5305 recently found an example which causes this new algorithm to fail in a
5306 very subtle way, producing bad debug information for those classes.
5307 The file 'gcc.patch' (in this directory) can be applied to gcc to
5308 circumvent the problem. A future GCC release will contain a complete
5311 The previous G++ debug info problem (mentioned below for the gdb-4.7
5312 release) is fixed in gcc version 2.3.2.
5314 * Improved configure script
5316 The `configure' script will now attempt to guess your system type if
5317 you don't supply a host system type. The old scheme of supplying a
5318 host system triplet is preferable over using this. All the magic is
5319 done in the new `config.guess' script. Examine it for details.
5321 We have also brought our configure script much more in line with the FSF's
5322 version. It now supports the --with-xxx options. In particular,
5323 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5324 The resulting GDB will not be able to read arbitrary object file formats --
5325 only the format ``expected'' to be used on the configured target system.
5326 We hope to make this the default in a future release.
5328 * Documentation improvements
5330 There's new internal documentation on how to modify GDB, and how to
5331 produce clean changes to the code. We implore people to read it
5332 before submitting changes.
5334 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5335 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5336 `info' files are also provided. To build `info' files from scratch,
5337 you will need the latest `makeinfo' release, which will be available in
5338 a future texinfo-X.Y release.
5340 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5341 We're not sure exactly which versions have this problem, but it has
5342 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5343 or better. If that isn't possible, there is a patch in
5344 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5345 around this problem.
5349 GDB now supports array constants that can be used in expressions typed in by
5350 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5351 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5354 The new directory `gdb/sparclite' contains a program that demonstrates
5355 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5357 * New native hosts supported
5359 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5360 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5362 * New targets supported
5364 AMD 29k family via UDI a29k-amd-udi or udi29k
5366 * New file formats supported
5368 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5369 HPUX core files, and SCO 3.2v2 core files.
5373 Attaching to processes now works again; thanks for the many bug reports.
5375 We have also stomped on a bunch of core dumps caused by
5376 printf_filtered("%s") problems.
5378 We eliminated a copyright problem on the rpc and ptrace header files
5379 for VxWorks, which was discovered at the last minute during the 4.7
5380 release. You should now be able to build a VxWorks GDB.
5382 You can now interrupt gdb while an attached process is running. This
5383 will cause the attached process to stop, and give control back to GDB.
5385 We fixed problems caused by using too many file descriptors
5386 for reading symbols from object files and libraries. This was
5387 especially a problem for programs that used many (~100) shared
5390 The `step' command now only enters a subroutine if there is line number
5391 information for the subroutine. Otherwise it acts like the `next'
5392 command. Previously, `step' would enter subroutines if there was
5393 any debugging information about the routine. This avoids problems
5394 when using `cc -g1' on MIPS machines.
5396 * Internal improvements
5398 GDB's internal interfaces have been improved to make it easier to support
5399 debugging of multiple languages in the future.
5401 GDB now uses a common structure for symbol information internally.
5402 Minimal symbols (derived from linkage symbols in object files), partial
5403 symbols (from a quick scan of debug information), and full symbols
5404 contain a common subset of information, making it easier to write
5405 shared code that handles any of them.
5407 * New command line options
5409 We now accept --silent as an alias for --quiet.
5413 The memory-mapped-malloc library is now licensed under the GNU Library
5414 General Public License.
5416 *** Changes in GDB-4.7:
5418 * Host/native/target split
5420 GDB has had some major internal surgery to untangle the support for
5421 hosts and remote targets. Now, when you configure GDB for a remote
5422 target, it will no longer load in all of the support for debugging
5423 local programs on the host. When fully completed and tested, this will
5424 ensure that arbitrary host/target combinations are possible.
5426 The primary conceptual shift is to separate the non-portable code in
5427 GDB into three categories. Host specific code is required any time GDB
5428 is compiled on that host, regardless of the target. Target specific
5429 code relates to the peculiarities of the target, but can be compiled on
5430 any host. Native specific code is everything else: it can only be
5431 built when the host and target are the same system. Child process
5432 handling and core file support are two common `native' examples.
5434 GDB's use of /proc for controlling Unix child processes is now cleaner.
5435 It has been split out into a single module under the `target_ops' vector,
5436 plus two native-dependent functions for each system that uses /proc.
5438 * New hosts supported
5440 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5441 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5442 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5444 * New targets supported
5446 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5447 68030 and CPU32 m68030-*-*, m68332-*-*
5449 * New native hosts supported
5451 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5452 (386bsd is not well tested yet)
5453 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5455 * New file formats supported
5457 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5458 supports reading of `a.out.adobe' object files, which are an a.out
5459 format extended with minimal information about multiple sections.
5463 `show copying' is the same as the old `info copying'.
5464 `show warranty' is the same as `info warrantee'.
5465 These were renamed for consistency. The old commands continue to work.
5467 `info handle' is a new alias for `info signals'.
5469 You can now define pre-command hooks, which attach arbitrary command
5470 scripts to any command. The commands in the hook will be executed
5471 prior to the user's command. You can also create a hook which will be
5472 executed whenever the program stops. See gdb.texinfo.
5476 We now deal with Cfront style name mangling, and can even extract type
5477 info from mangled symbols. GDB can automatically figure out which
5478 symbol mangling style your C++ compiler uses.
5480 Calling of methods and virtual functions has been improved as well.
5484 The crash that occured when debugging Sun Ansi-C compiled binaries is
5485 fixed. This was due to mishandling of the extra N_SO stabs output
5488 We also finally got Ultrix 4.2 running in house, and fixed core file
5489 support, with help from a dozen people on the net.
5491 John M. Farrell discovered that the reason that single-stepping was so
5492 slow on all of the Mips based platforms (primarily SGI and DEC) was
5493 that we were trying to demangle and lookup a symbol used for internal
5494 purposes on every instruction that was being stepped through. Changing
5495 the name of that symbol so that it couldn't be mistaken for a C++
5496 mangled symbol sped things up a great deal.
5498 Rich Pixley sped up symbol lookups in general by getting much smarter
5499 about when C++ symbol mangling is necessary. This should make symbol
5500 completion (TAB on the command line) much faster. It's not as fast as
5501 we'd like, but it's significantly faster than gdb-4.6.
5505 A new user controllable variable 'call_scratch_address' can
5506 specify the location of a scratch area to be used when GDB
5507 calls a function in the target. This is necessary because the
5508 usual method of putting the scratch area on the stack does not work
5509 in systems that have separate instruction and data spaces.
5511 We integrated changes to support the 29k UDI (Universal Debugger
5512 Interface), but discovered at the last minute that we didn't have all
5513 of the appropriate copyright paperwork. We are working with AMD to
5514 resolve this, and hope to have it available soon.
5518 We have sped up the remote serial line protocol, especially for targets
5519 with lots of registers. It now supports a new `expedited status' ('T')
5520 message which can be used in place of the existing 'S' status message.
5521 This allows the remote stub to send only the registers that GDB
5522 needs to make a quick decision about single-stepping or conditional
5523 breakpoints, eliminating the need to fetch the entire register set for
5524 each instruction being stepped through.
5526 The GDB remote serial protocol now implements a write-through cache for
5527 registers, only re-reading the registers if the target has run.
5529 There is also a new remote serial stub for SPARC processors. You can
5530 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5531 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5532 processor with a serial port.
5536 Configure.in files have become much easier to read and modify. A new
5537 `table driven' format makes it more obvious what configurations are
5538 supported, and what files each one uses.
5542 There is a new opcodes library which will eventually contain all of the
5543 disassembly routines and opcode tables. At present, it only contains
5544 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5545 disassembler (binutils/objdump) to share these routines.
5547 The libiberty library is now copylefted under the GNU Library General
5548 Public License. This allows more liberal use, and was done so libg++
5549 can use it. This makes no difference to GDB, since the Library License
5550 grants all the rights from the General Public License.
5554 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5555 reference to the stabs symbol info used by the debugger. It is (as far
5556 as we know) the only published document on this fascinating topic. We
5557 encourage you to read it, compare it to the stabs information on your
5558 system, and send improvements on the document in general (to
5559 bug-gdb@prep.ai.mit.edu).
5561 And, of course, many bugs have been fixed.
5564 *** Changes in GDB-4.6:
5566 * Better support for C++ function names
5568 GDB now accepts as input the "demangled form" of C++ overloaded function
5569 names and member function names, and can do command completion on such names
5570 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5571 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5572 Make use of command completion, it is your friend.
5574 GDB also now accepts a variety of C++ mangled symbol formats. They are
5575 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5576 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5577 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5578 for the list of formats.
5580 * G++ symbol mangling problem
5582 Recent versions of gcc have a bug in how they emit debugging information for
5583 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5584 directory) can be applied to gcc to fix the problem. Alternatively, if you
5585 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5586 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5587 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5590 * New 'maintenance' command
5592 All of the commands related to hacking GDB internals have been moved out of
5593 the main command set, and now live behind the 'maintenance' command. This
5594 can also be abbreviated as 'mt'. The following changes were made:
5596 dump-me -> maintenance dump-me
5597 info all-breakpoints -> maintenance info breakpoints
5598 printmsyms -> maintenance print msyms
5599 printobjfiles -> maintenance print objfiles
5600 printpsyms -> maintenance print psymbols
5601 printsyms -> maintenance print symbols
5603 The following commands are new:
5605 maintenance demangle Call internal GDB demangler routine to
5606 demangle a C++ link name and prints the result.
5607 maintenance print type Print a type chain for a given symbol
5609 * Change to .gdbinit file processing
5611 We now read the $HOME/.gdbinit file before processing the argv arguments
5612 (e.g. reading symbol files or core files). This allows global parameters to
5613 be set, which will apply during the symbol reading. The ./.gdbinit is still
5614 read after argv processing.
5616 * New hosts supported
5618 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5620 GNU/Linux support i386-unknown-linux or linux
5622 We are also including code to support the HP/PA running BSD and HPUX. This
5623 is almost guaranteed not to work, as we didn't have time to test or build it
5624 for this release. We are including it so that the more adventurous (or
5625 masochistic) of you can play with it. We also had major problems with the
5626 fact that the compiler that we got from HP doesn't support the -g option.
5629 * New targets supported
5631 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5633 * More smarts about finding #include files
5635 GDB now remembers the compilation directory for all include files, and for
5636 all files from which C is generated (like yacc and lex sources). This
5637 greatly improves GDB's ability to find yacc/lex sources, and include files,
5638 especially if you are debugging your program from a directory different from
5639 the one that contains your sources.
5641 We also fixed a bug which caused difficulty with listing and setting
5642 breakpoints in include files which contain C code. (In the past, you had to
5643 try twice in order to list an include file that you hadn't looked at before.)
5645 * Interesting infernals change
5647 GDB now deals with arbitrary numbers of sections, where the symbols for each
5648 section must be relocated relative to that section's landing place in the
5649 target's address space. This work was needed to support ELF with embedded
5650 stabs used by Solaris-2.0.
5652 * Bug fixes (of course!)
5654 There have been loads of fixes for the following things:
5655 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5656 i960, stabs, DOS(GO32), procfs, etc...
5658 See the ChangeLog for details.
5660 *** Changes in GDB-4.5:
5662 * New machines supported (host and target)
5664 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5666 SGI Irix-4.x mips-sgi-irix4 or iris4
5668 * New malloc package
5670 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5671 Mmalloc is capable of handling mutiple heaps of memory. It is also
5672 capable of saving a heap to a file, and then mapping it back in later.
5673 This can be used to greatly speedup the startup of GDB by using a
5674 pre-parsed symbol table which lives in a mmalloc managed heap. For
5675 more details, please read mmalloc/mmalloc.texi.
5679 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5680 'help info proc' for details.
5682 * MIPS ecoff symbol table format
5684 The code that reads MIPS symbol table format is now supported on all hosts.
5685 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5688 * File name changes for MS-DOS
5690 Many files in the config directories have been renamed to make it easier to
5691 support GDB on MS-DOSe systems (which have very restrictive file name
5692 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5693 environment) is close to working but has some remaining problems. Note
5694 that debugging of DOS programs is not supported, due to limitations
5695 in the ``operating system'', but it can be used to host cross-debugging.
5697 * Cross byte order fixes
5699 Many fixes have been made to support cross debugging of Sparc and MIPS
5700 targets from hosts whose byte order differs.
5702 * New -mapped and -readnow options
5704 If memory-mapped files are available on your system through the 'mmap'
5705 system call, you can use the -mapped option on the `file' or
5706 `symbol-file' commands to cause GDB to write the symbols from your
5707 program into a reusable file. If the program you are debugging is
5708 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5709 Future GDB debugging sessions will notice the presence of this file,
5710 and will quickly map in symbol information from it, rather than reading
5711 the symbol table from the executable program. Using the '-mapped'
5712 option in a GDB `file' or `symbol-file' command has the same effect as
5713 starting GDB with the '-mapped' command-line option.
5715 You can cause GDB to read the entire symbol table immediately by using
5716 the '-readnow' option with any of the commands that load symbol table
5717 information (or on the GDB command line). This makes the command
5718 slower, but makes future operations faster.
5720 The -mapped and -readnow options are typically combined in order to
5721 build a `fred.syms' file that contains complete symbol information.
5722 A simple GDB invocation to do nothing but build a `.syms' file for future
5725 gdb -batch -nx -mapped -readnow programname
5727 The `.syms' file is specific to the host machine on which GDB is run.
5728 It holds an exact image of GDB's internal symbol table. It cannot be
5729 shared across multiple host platforms.
5731 * longjmp() handling
5733 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5734 siglongjmp() without losing control. This feature has not yet been ported to
5735 all systems. It currently works on many 386 platforms, all MIPS-based
5736 platforms (SGI, DECstation, etc), and Sun3/4.
5740 Preliminary work has been put in to support the new Solaris OS from Sun. At
5741 this time, it can control and debug processes, but it is not capable of
5746 As always, many many bug fixes. The major areas were with g++, and mipsread.
5747 People using the MIPS-based platforms should experience fewer mysterious
5748 crashes and trashed symbol tables.
5750 *** Changes in GDB-4.4:
5752 * New machines supported (host and target)
5754 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5756 BSD Reno on Vax vax-dec-bsd
5757 Ultrix on Vax vax-dec-ultrix
5759 * New machines supported (target)
5761 AMD 29000 embedded, using EBMON a29k-none-none
5765 GDB continues to improve its handling of C++. `References' work better.
5766 The demangler has also been improved, and now deals with symbols mangled as
5767 per the Annotated C++ Reference Guide.
5769 GDB also now handles `stabs' symbol information embedded in MIPS
5770 `ecoff' symbol tables. Since the ecoff format was not easily
5771 extensible to handle new languages such as C++, this appeared to be a
5772 good way to put C++ debugging info into MIPS binaries. This option
5773 will be supported in the GNU C compiler, version 2, when it is
5776 * New features for SVR4
5778 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5779 shared libraries. Debugging dynamically linked programs should present
5780 only minor differences from debugging statically linked programs.
5782 The `info proc' command will print out information about any process
5783 on an SVR4 system (including the one you are debugging). At the moment,
5784 it prints the address mappings of the process.
5786 If you bring up GDB on another SVR4 system, please send mail to
5787 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5789 * Better dynamic linking support in SunOS
5791 Reading symbols from shared libraries which contain debugging symbols
5792 now works properly. However, there remain issues such as automatic
5793 skipping of `transfer vector' code during function calls, which
5794 make it harder to debug code in a shared library, than to debug the
5795 same code linked statically.
5799 GDB is now using the latest `getopt' routines from the FSF. This
5800 version accepts the -- prefix for options with long names. GDB will
5801 continue to accept the old forms (-option and +option) as well.
5802 Various single letter abbreviations for options have been explicity
5803 added to the option table so that they won't get overshadowed in the
5804 future by other options that begin with the same letter.
5808 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5809 Many assorted bugs have been handled. Many more remain to be handled.
5810 See the various ChangeLog files (primarily in gdb and bfd) for details.
5813 *** Changes in GDB-4.3:
5815 * New machines supported (host and target)
5817 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5818 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5819 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5821 * Almost SCO Unix support
5823 We had hoped to support:
5824 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5825 (except for core file support), but we discovered very late in the release
5826 that it has problems with process groups that render gdb unusable. Sorry
5827 about that. I encourage people to fix it and post the fixes.
5829 * Preliminary ELF and DWARF support
5831 GDB can read ELF object files on System V Release 4, and can handle
5832 debugging records for C, in DWARF format, in ELF files. This support
5833 is preliminary. If you bring up GDB on another SVR4 system, please
5834 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5839 GDB now uses the latest `readline' library. One user-visible change
5840 is that two tabs will list possible command completions, which previously
5841 required typing M-? (meta-question mark, or ESC ?).
5845 The `stepi' bug that many of you noticed has been squashed.
5846 Many bugs in C++ have been handled. Many more remain to be handled.
5847 See the various ChangeLog files (primarily in gdb and bfd) for details.
5849 * State of the MIPS world (in case you wondered):
5851 GDB can understand the symbol tables emitted by the compilers
5852 supplied by most vendors of MIPS-based machines, including DEC. These
5853 symbol tables are in a format that essentially nobody else uses.
5855 Some versions of gcc come with an assembler post-processor called
5856 mips-tfile. This program is required if you want to do source-level
5857 debugging of gcc-compiled programs. I believe FSF does not ship
5858 mips-tfile with gcc version 1, but it will eventually come with gcc
5861 Debugging of g++ output remains a problem. g++ version 1.xx does not
5862 really support it at all. (If you're lucky, you should be able to get
5863 line numbers and stack traces to work, but no parameters or local
5864 variables.) With some work it should be possible to improve the
5867 When gcc version 2 is released, you will have somewhat better luck.
5868 However, even then you will get confusing results for inheritance and
5871 We will eventually provide full debugging of g++ output on
5872 DECstations. This will probably involve some kind of stabs-in-ecoff
5873 encapulation, but the details have not been worked out yet.
5876 *** Changes in GDB-4.2:
5878 * Improved configuration
5880 Only one copy of `configure' exists now, and it is not self-modifying.
5881 Porting BFD is simpler.
5885 The `step' and `next' commands now only stop at the first instruction
5886 of a source line. This prevents the multiple stops that used to occur
5887 in switch statements, for-loops, etc. `Step' continues to stop if a
5888 function that has debugging information is called within the line.
5892 Lots of small bugs fixed. More remain.
5894 * New host supported (not target)
5896 Intel 386 PC clone running Mach i386-none-mach
5899 *** Changes in GDB-4.1:
5901 * Multiple source language support
5903 GDB now has internal scaffolding to handle several source languages.
5904 It determines the type of each source file from its filename extension,
5905 and will switch expression parsing and number formatting to match the
5906 language of the function in the currently selected stack frame.
5907 You can also specifically set the language to be used, with
5908 `set language c' or `set language modula-2'.
5912 GDB now has preliminary support for the GNU Modula-2 compiler,
5913 currently under development at the State University of New York at
5914 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5915 continue through the fall of 1991 and into 1992.
5917 Other Modula-2 compilers are currently not supported, and attempting to
5918 debug programs compiled with them will likely result in an error as the
5919 symbol table is read. Feel free to work on it, though!
5921 There are hooks in GDB for strict type checking and range checking,
5922 in the `Modula-2 philosophy', but they do not currently work.
5926 GDB can now write to executable and core files (e.g. patch
5927 a variable's value). You must turn this switch on, specify
5928 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5929 by assigning a new value to a variable. Modifications take
5932 * Automatic SunOS shared library reading
5934 When you run your program, GDB automatically determines where its
5935 shared libraries (if any) have been loaded, and reads their symbols.
5936 The `share' command is no longer needed. This also works when
5937 examining core files.
5941 You can specify the number of lines that the `list' command shows.
5944 * New machines supported (host and target)
5946 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5947 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5948 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5950 * New hosts supported (not targets)
5952 IBM RT/PC: romp-ibm-aix or rtpc
5954 * New targets supported (not hosts)
5956 AMD 29000 embedded with COFF a29k-none-coff
5957 AMD 29000 embedded with a.out a29k-none-aout
5958 Ultracomputer remote kernel debug a29k-nyu-kern
5960 * New remote interfaces
5966 *** Changes in GDB-4.0:
5970 Wide output is wrapped at good places to make the output more readable.
5972 Gdb now supports cross-debugging from a host machine of one type to a
5973 target machine of another type. Communication with the target system
5974 is over serial lines. The ``target'' command handles connecting to the
5975 remote system; the ``load'' command will download a program into the
5976 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5977 also supports debugging of realtime processes running under VxWorks,
5978 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5979 stub on the target system.
5981 New CPUs supported include the AMD 29000 and Intel 960.
5983 GDB now reads object files and symbol tables via a ``binary file''
5984 library, which allows a single copy of GDB to debug programs of multiple
5985 object file types such as a.out and coff.
5987 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5988 refcard.dvi and refcard.ps are available to format it).
5991 * Control-Variable user interface simplified
5993 All variables that control the operation of the debugger can be set
5994 by the ``set'' command, and displayed by the ``show'' command.
5996 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5997 ``Show prompt'' produces the response:
5998 Gdb's prompt is new-gdb=>.
6000 What follows are the NEW set commands. The command ``help set'' will
6001 print a complete list of old and new set commands. ``help set FOO''
6002 will give a longer description of the variable FOO. ``show'' will show
6003 all of the variable descriptions and their current settings.
6005 confirm on/off: Enables warning questions for operations that are
6006 hard to recover from, e.g. rerunning the program while
6007 it is already running. Default is ON.
6009 editing on/off: Enables EMACS style command line editing
6010 of input. Previous lines can be recalled with
6011 control-P, the current line can be edited with control-B,
6012 you can search for commands with control-R, etc.
6015 history filename NAME: NAME is where the gdb command history
6016 will be stored. The default is .gdb_history,
6017 or the value of the environment variable
6020 history size N: The size, in commands, of the command history. The
6021 default is 256, or the value of the environment variable
6024 history save on/off: If this value is set to ON, the history file will
6025 be saved after exiting gdb. If set to OFF, the
6026 file will not be saved. The default is OFF.
6028 history expansion on/off: If this value is set to ON, then csh-like
6029 history expansion will be performed on
6030 command line input. The default is OFF.
6032 radix N: Sets the default radix for input and output. It can be set
6033 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6034 in the current radix, so "set radix 10" is always a no-op.
6036 height N: This integer value is the number of lines on a page. Default
6037 is 24, the current `stty rows'' setting, or the ``li#''
6038 setting from the termcap entry matching the environment
6041 width N: This integer value is the number of characters on a line.
6042 Default is 80, the current `stty cols'' setting, or the ``co#''
6043 setting from the termcap entry matching the environment
6046 Note: ``set screensize'' is obsolete. Use ``set height'' and
6047 ``set width'' instead.
6049 print address on/off: Print memory addresses in various command displays,
6050 such as stack traces and structure values. Gdb looks
6051 more ``symbolic'' if you turn this off; it looks more
6052 ``machine level'' with it on. Default is ON.
6054 print array on/off: Prettyprint arrays. New convenient format! Default
6057 print demangle on/off: Print C++ symbols in "source" form if on,
6060 print asm-demangle on/off: Same, for assembler level printouts
6063 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6066 * Support for Epoch Environment.
6068 The epoch environment is a version of Emacs v18 with windowing. One
6069 new command, ``inspect'', is identical to ``print'', except that if you
6070 are running in the epoch environment, the value is printed in its own
6074 * Support for Shared Libraries
6076 GDB can now debug programs and core files that use SunOS shared libraries.
6077 Symbols from a shared library cannot be referenced
6078 before the shared library has been linked with the program (this
6079 happens after you type ``run'' and before the function main() is entered).
6080 At any time after this linking (including when examining core files
6081 from dynamically linked programs), gdb reads the symbols from each
6082 shared library when you type the ``sharedlibrary'' command.
6083 It can be abbreviated ``share''.
6085 sharedlibrary REGEXP: Load shared object library symbols for files
6086 matching a unix regular expression. No argument
6087 indicates to load symbols for all shared libraries.
6089 info sharedlibrary: Status of loaded shared libraries.
6094 A watchpoint stops execution of a program whenever the value of an
6095 expression changes. Checking for this slows down execution
6096 tremendously whenever you are in the scope of the expression, but is
6097 quite useful for catching tough ``bit-spreader'' or pointer misuse
6098 problems. Some machines such as the 386 have hardware for doing this
6099 more quickly, and future versions of gdb will use this hardware.
6101 watch EXP: Set a watchpoint (breakpoint) for an expression.
6103 info watchpoints: Information about your watchpoints.
6105 delete N: Deletes watchpoint number N (same as breakpoints).
6106 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6107 enable N: Re-enables watchpoint number N (same as breakpoints).
6110 * C++ multiple inheritance
6112 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6115 * C++ exception handling
6117 Gdb now supports limited C++ exception handling. Besides the existing
6118 ability to breakpoint on an exception handler, gdb can breakpoint on
6119 the raising of an exception (before the stack is peeled back to the
6122 catch FOO: If there is a FOO exception handler in the dynamic scope,
6123 set a breakpoint to catch exceptions which may be raised there.
6124 Multiple exceptions (``catch foo bar baz'') may be caught.
6126 info catch: Lists all exceptions which may be caught in the
6127 current stack frame.
6130 * Minor command changes
6132 The command ``call func (arg, arg, ...)'' now acts like the print
6133 command, except it does not print or save a value if the function's result
6134 is void. This is similar to dbx usage.
6136 The ``up'' and ``down'' commands now always print the frame they end up
6137 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6138 frames without printing.
6140 * New directory command
6142 'dir' now adds directories to the FRONT of the source search path.
6143 The path starts off empty. Source files that contain debug information
6144 about the directory in which they were compiled can be found even
6145 with an empty path; Sun CC and GCC include this information. If GDB can't
6146 find your source file in the current directory, type "dir .".
6148 * Configuring GDB for compilation
6150 For normal use, type ``./configure host''. See README or gdb.texinfo
6153 GDB now handles cross debugging. If you are remotely debugging between
6154 two different machines, type ``./configure host -target=targ''.
6155 Host is the machine where GDB will run; targ is the machine
6156 where the program that you are debugging will run.