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 *** Changes in GDB 7.9.1
253 ** Xmethods can now specify a result type.
255 *** Changes in GDB 7.9
257 * GDB now supports hardware watchpoints on x86 GNU Hurd.
261 ** You can now access frame registers from Python scripts.
262 ** New attribute 'producer' for gdb.Symtab objects.
263 ** gdb.Objfile objects have a new attribute "progspace",
264 which is the gdb.Progspace object of the containing program space.
265 ** gdb.Objfile objects have a new attribute "owner".
266 ** gdb.Objfile objects have a new attribute "build_id",
267 which is the build ID generated when the file was built.
268 ** gdb.Objfile objects have a new method "add_separate_debug_file".
269 ** A new event "gdb.clear_objfiles" has been added, triggered when
270 selecting a new file to debug.
271 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
272 ** New function gdb.lookup_objfile.
274 New events which are triggered when GDB modifies the state of the
277 ** gdb.events.inferior_call_pre: Function call is about to be made.
278 ** gdb.events.inferior_call_post: Function call has just been made.
279 ** gdb.events.memory_changed: A memory location has been altered.
280 ** gdb.events.register_changed: A register has been altered.
282 * New Python-based convenience functions:
284 ** $_caller_is(name [, number_of_frames])
285 ** $_caller_matches(regexp [, number_of_frames])
286 ** $_any_caller_is(name [, number_of_frames])
287 ** $_any_caller_matches(regexp [, number_of_frames])
289 * GDB now supports the compilation and injection of source code into
290 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
291 to compile the source code to object code, and if successful, inject
292 and execute that code within the current context of the inferior.
293 Currently the C language is supported. The commands used to
294 interface with this new feature are:
296 compile code [-raw|-r] [--] [source code]
297 compile file [-raw|-r] filename
301 demangle [-l language] [--] name
302 Demangle "name" in the specified language, or the current language
303 if elided. This command is renamed from the "maint demangle" command.
304 The latter is kept as a no-op to avoid "maint demangle" being interpreted
305 as "maint demangler-warning".
307 queue-signal signal-name-or-number
308 Queue a signal to be delivered to the thread when it is resumed.
310 add-auto-load-scripts-directory directory
311 Add entries to the list of directories from which to load auto-loaded
314 maint print user-registers
315 List all currently available "user" registers.
317 compile code [-r|-raw] [--] [source code]
318 Compile, inject, and execute in the inferior the executable object
319 code produced by compiling the provided source code.
321 compile file [-r|-raw] filename
322 Compile and inject into the inferior the executable object code
323 produced by compiling the source code stored in the filename
326 * On resume, GDB now always passes the signal the program had stopped
327 for to the thread the signal was sent to, even if the user changed
328 threads before resuming. Previously GDB would often (but not
329 always) deliver the signal to the thread that happens to be current
332 * Conversely, the "signal" command now consistently delivers the
333 requested signal to the current thread. GDB now asks for
334 confirmation if the program had stopped for a signal and the user
335 switched threads meanwhile.
337 * "breakpoint always-inserted" modes "off" and "auto" merged.
339 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
340 won't remove breakpoints from the target until all threads stop,
341 even in non-stop mode. The "auto" mode has been removed, and "off"
342 is now the default mode.
346 set debug symbol-lookup
347 show debug symbol-lookup
348 Control display of debugging info regarding symbol lookup.
352 ** The -list-thread-groups command outputs an exit-code field for
353 inferiors that have exited.
357 MIPS SDE mips*-sde*-elf*
361 Support for these obsolete configurations has been removed.
363 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
364 SGI Irix-5.x mips-*-irix5*
365 SGI Irix-6.x mips-*-irix6*
366 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
367 VAX running Ultrix vax-*-ultrix*
369 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
370 and "assf"), have been removed. Use the "sharedlibrary" command, or
371 its alias "share", instead.
373 *** Changes in GDB 7.8
375 * New command line options
378 This is an alias for the --data-directory option.
380 * GDB supports printing and modifying of variable length automatic arrays
381 as specified in ISO C99.
383 * The ARM simulator now supports instruction level tracing
384 with or without disassembly.
388 GDB now has support for scripting using Guile. Whether this is
389 available is determined at configure time.
390 Guile version 2.0 or greater is required.
391 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
393 * New commands (for set/show, see "New options" below)
397 Invoke CODE by passing it to the Guile interpreter.
401 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
403 info auto-load guile-scripts [regexp]
404 Print the list of automatically loaded Guile scripts.
406 * The source command is now capable of sourcing Guile scripts.
407 This feature is dependent on the debugger being built with Guile support.
411 set print symbol-loading (off|brief|full)
412 show print symbol-loading
413 Control whether to print informational messages when loading symbol
414 information for a file. The default is "full", but when debugging
415 programs with large numbers of shared libraries the amount of output
418 set guile print-stack (none|message|full)
419 show guile print-stack
420 Show a stack trace when an error is encountered in a Guile script.
422 set auto-load guile-scripts (on|off)
423 show auto-load guile-scripts
424 Control auto-loading of Guile script files.
426 maint ada set ignore-descriptive-types (on|off)
427 maint ada show ignore-descriptive-types
428 Control whether the debugger should ignore descriptive types in Ada
429 programs. The default is not to ignore the descriptive types. See
430 the user manual for more details on descriptive types and the intended
431 usage of this option.
433 set auto-connect-native-target
435 Control whether GDB is allowed to automatically connect to the
436 native target for the run, attach, etc. commands when not connected
437 to any target yet. See also "target native" below.
439 set record btrace replay-memory-access (read-only|read-write)
440 show record btrace replay-memory-access
441 Control what memory accesses are allowed during replay.
443 maint set target-async (on|off)
444 maint show target-async
445 This controls whether GDB targets operate in synchronous or
446 asynchronous mode. Normally the default is asynchronous, if it is
447 available; but this can be changed to more easily debug problems
448 occurring only in synchronous mode.
450 set mi-async (on|off)
452 Control whether MI asynchronous mode is preferred. This supersedes
453 "set target-async" of previous GDB versions.
455 * "set target-async" is deprecated as a CLI option and is now an alias
456 for "set mi-async" (only puts MI into async mode).
458 * Background execution commands (e.g., "c&", "s&", etc.) are now
459 possible ``out of the box'' if the target supports them. Previously
460 the user would need to explicitly enable the possibility with the
461 "set target-async on" command.
463 * New features in the GDB remote stub, GDBserver
465 ** New option --debug-format=option1[,option2,...] allows one to add
466 additional text to each output. At present only timestamps
467 are supported: --debug-format=timestamps.
468 Timestamps can also be turned on with the
469 "monitor set debug-format timestamps" command from GDB.
471 * The 'record instruction-history' command now starts counting instructions
472 at one. This also affects the instruction ranges reported by the
473 'record function-call-history' command when given the /i modifier.
475 * The command 'record function-call-history' supports a new modifier '/c' to
476 indent the function names based on their call stack depth.
477 The fields for the '/i' and '/l' modifier have been reordered.
478 The source line range is now prefixed with 'at'.
479 The instruction range is now prefixed with 'inst'.
480 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
481 "record instruction-history" and "list" commands.
483 * The ranges given as arguments to the 'record function-call-history' and
484 'record instruction-history' commands are now inclusive.
486 * The btrace record target now supports the 'record goto' command.
487 For locations inside the execution trace, the back trace is computed
488 based on the information stored in the execution trace.
490 * The btrace record target supports limited reverse execution and replay.
491 The target does not record data and therefore does not allow reading
494 * The "catch syscall" command now works on s390*-linux* targets.
496 * The "compare-sections" command is no longer specific to target
497 remote. It now works with all targets.
499 * All native targets are now consistently called "native".
500 Consequently, the "target child", "target GNU", "target djgpp",
501 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
502 commands have been replaced with "target native". The QNX/NTO port
503 leaves the "procfs" target in place and adds a "native" target for
504 consistency with other ports. The impact on users should be minimal
505 as these commands previously either throwed an error, or were
506 no-ops. The target's name is visible in the output of the following
507 commands: "help target", "info target", "info files", "maint print
510 * The "target native" command now connects to the native target. This
511 can be used to launch native programs even when "set
512 auto-connect-native-target" is set to off.
514 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.
516 * Support for Intel(R) AVX-512 registers on GNU/Linux.
517 Support displaying and modifying Intel(R) AVX-512 registers
518 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
522 qXfer:btrace:read's annex
523 The qXfer:btrace:read packet supports a new annex 'delta' to read
524 branch trace incrementally.
528 ** Valid Python operations on gdb.Value objects representing
529 structs/classes invoke the corresponding overloaded operators if
531 ** New `Xmethods' feature in the Python API. Xmethods are
532 additional methods or replacements for existing methods of a C++
533 class. This feature is useful for those cases where a method
534 defined in C++ source code could be inlined or optimized out by
535 the compiler, making it unavailable to GDB.
538 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
540 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
541 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
542 its alias "share", instead.
544 * The commands "set remotebaud" and "show remotebaud" are no longer
545 supported. Use "set serial baud" and "show serial baud" (respectively)
550 ** A new option "-gdb-set mi-async" replaces "-gdb-set
551 target-async". The latter is left as a deprecated alias of the
552 former for backward compatibility. If the target supports it,
553 CLI background execution commands are now always possible by
554 default, independently of whether the frontend stated a
555 preference for asynchronous execution with "-gdb-set mi-async".
556 Previously "-gdb-set target-async off" affected both MI execution
557 commands and CLI execution commands.
559 *** Changes in GDB 7.7
561 * Improved support for process record-replay and reverse debugging on
562 arm*-linux* targets. Support for thumb32 and syscall instruction
563 recording has been added.
565 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
567 * GDB now supports Fission DWP file format version 2.
568 http://gcc.gnu.org/wiki/DebugFission
570 * New convenience function "$_isvoid", to check whether an expression
571 is void. A void expression is an expression where the type of the
572 result is "void". For example, some convenience variables may be
573 "void" when evaluated (e.g., "$_exitcode" before the execution of
574 the program being debugged; or an undefined convenience variable).
575 Another example, when calling a function whose return type is
578 * The "maintenance print objfiles" command now takes an optional regexp.
580 * The "catch syscall" command now works on arm*-linux* targets.
582 * GDB now consistently shows "<not saved>" when printing values of
583 registers the debug info indicates have not been saved in the frame
584 and there's nowhere to retrieve them from
585 (callee-saved/call-clobbered registers):
590 (gdb) info registers rax
593 Before, the former would print "<optimized out>", and the latter
594 "*value not available*".
596 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
601 ** Frame filters and frame decorators have been added.
602 ** Temporary breakpoints are now supported.
603 ** Line tables representation has been added.
604 ** New attribute 'parent_type' for gdb.Field objects.
605 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
606 ** New attribute 'name' for gdb.Type objects.
610 Nios II ELF nios2*-*-elf
611 Nios II GNU/Linux nios2*-*-linux
612 Texas Instruments MSP430 msp430*-*-elf
614 * Removed native configurations
616 Support for these a.out NetBSD and OpenBSD obsolete configurations has
617 been removed. ELF variants of these configurations are kept supported.
619 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
620 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
621 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
622 i[34567]86-*-openbsd3.[0-3]
623 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
624 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
625 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
629 Like "catch throw", but catches a re-thrown exception.
631 Renamed from old "maint check-symtabs".
633 Perform consistency checks on symtabs.
635 Expand symtabs matching an optional regexp.
638 Display the details of GDB configure-time options.
640 maint set|show per-command
641 maint set|show per-command space
642 maint set|show per-command time
643 maint set|show per-command symtab
644 Enable display of per-command gdb resource usage.
646 remove-symbol-file FILENAME
647 remove-symbol-file -a ADDRESS
648 Remove a symbol file added via add-symbol-file. The file to remove
649 can be identified by its filename or by an address that lies within
650 the boundaries of this symbol file in memory.
653 info exceptions REGEXP
654 Display the list of Ada exceptions defined in the program being
655 debugged. If provided, only the exceptions whose names match REGEXP
660 set debug symfile off|on
662 Control display of debugging info regarding reading symbol files and
663 symbol tables within those files
665 set print raw frame-arguments
666 show print raw frame-arguments
667 Set/show whether to print frame arguments in raw mode,
668 disregarding any defined pretty-printers.
670 set remote trace-status-packet
671 show remote trace-status-packet
672 Set/show the use of remote protocol qTStatus packet.
676 Control display of debugging messages related to Nios II targets.
680 Control whether target-assisted range stepping is enabled.
682 set startup-with-shell
683 show startup-with-shell
684 Specifies whether Unix child processes are started via a shell or
689 Use the target memory cache for accesses to the code segment. This
690 improves performance of remote debugging (particularly disassembly).
692 * You can now use a literal value 'unlimited' for options that
693 interpret 0 or -1 as meaning "unlimited". E.g., "set
694 trace-buffer-size unlimited" is now an alias for "set
695 trace-buffer-size -1" and "set height unlimited" is now an alias for
698 * The "set debug symtab-create" debugging option of GDB has been changed to
699 accept a verbosity level. 0 means "off", 1 provides basic debugging
700 output, and values of 2 or greater provides more verbose output.
702 * New command-line options
704 Display the details of GDB configure-time options.
706 * The command 'tsave' can now support new option '-ctf' to save trace
707 buffer in Common Trace Format.
709 * Newly installed $prefix/bin/gcore acts as a shell interface for the
712 * GDB now implements the the C++ 'typeid' operator.
714 * The new convenience variable $_exception holds the exception being
715 thrown or caught at an exception-related catchpoint.
717 * The exception-related catchpoints, like "catch throw", now accept a
718 regular expression which can be used to filter exceptions by type.
720 * The new convenience variable $_exitsignal is automatically set to
721 the terminating signal number when the program being debugged dies
722 due to an uncaught signal.
726 ** All MI commands now accept an optional "--language" option.
727 Support for this feature can be verified by using the "-list-features"
728 command, which should contain "language-option".
730 ** The new command -info-gdb-mi-command allows the user to determine
731 whether a GDB/MI command is supported or not.
733 ** The "^error" result record returned when trying to execute an undefined
734 GDB/MI command now provides a variable named "code" whose content is the
735 "undefined-command" error code. Support for this feature can be verified
736 by using the "-list-features" command, which should contain
737 "undefined-command-error-code".
739 ** The -trace-save MI command can optionally save trace buffer in Common
742 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
744 ** The command -data-list-register-values now accepts an optional
745 "--skip-unavailable" option. When used, only the available registers
748 ** The new command -trace-frame-collected dumps collected variables,
749 computed expressions, tvars, memory and registers in a traceframe.
751 ** The commands -stack-list-locals, -stack-list-arguments and
752 -stack-list-variables now accept an option "--skip-unavailable".
753 When used, only the available locals or arguments are displayed.
755 ** The -exec-run command now accepts an optional "--start" option.
756 When used, the command follows the same semantics as the "start"
757 command, stopping the program's execution at the start of its
758 main subprogram. Support for this feature can be verified using
759 the "-list-features" command, which should contain
760 "exec-run-start-option".
762 ** The new commands -catch-assert and -catch-exceptions insert
763 catchpoints stopping the program when Ada exceptions are raised.
765 ** The new command -info-ada-exceptions provides the equivalent of
766 the new "info exceptions" command.
768 * New system-wide configuration scripts
769 A GDB installation now provides scripts suitable for use as system-wide
770 configuration scripts for the following systems:
774 * GDB now supports target-assigned range stepping with remote targets.
775 This improves the performance of stepping source lines by reducing
776 the number of control packets from/to GDB. See "New remote packets"
779 * GDB now understands the element 'tvar' in the XML traceframe info.
780 It has the id of the collected trace state variables.
782 * On S/390 targets that provide the transactional-execution feature,
783 the program interruption transaction diagnostic block (TDB) is now
784 represented as a number of additional "registers" in GDB.
790 The vCont packet supports a new 'r' action, that tells the remote
791 stub to step through an address range itself, without GDB
792 involvemement at each single-step.
794 qXfer:libraries-svr4:read's annex
795 The previously unused annex of the qXfer:libraries-svr4:read packet
796 is now used to support passing an argument list. The remote stub
797 reports support for this argument list to GDB's qSupported query.
798 The defined arguments are "start" and "prev", used to reduce work
799 necessary for library list updating, resulting in significant
802 * New features in the GDB remote stub, GDBserver
804 ** GDBserver now supports target-assisted range stepping. Currently
805 enabled on x86/x86_64 GNU/Linux targets.
807 ** GDBserver now adds element 'tvar' in the XML in the reply to
808 'qXfer:traceframe-info:read'. It has the id of the collected
809 trace state variables.
811 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
814 * New 'z' formatter for printing and examining memory, this displays the
815 value as hexadecimal zero padded on the left to the size of the type.
817 * GDB can now use Windows x64 unwinding data.
819 * The "set remotebaud" command has been replaced by "set serial baud".
820 Similarly, "show remotebaud" has been replaced by "show serial baud".
821 The "set remotebaud" and "show remotebaud" commands are still available
822 to provide backward compatibility with older versions of GDB.
824 *** Changes in GDB 7.6
826 * Target record has been renamed to record-full.
827 Record/replay is now enabled with the "record full" command.
828 This also affects settings that are associated with full record/replay
829 that have been moved from "set/show record" to "set/show record full":
831 set|show record full insn-number-max
832 set|show record full stop-at-limit
833 set|show record full memory-query
835 * A new record target "record-btrace" has been added. The new target
836 uses hardware support to record the control-flow of a process. It
837 does not support replaying the execution, but it implements the
838 below new commands for investigating the recorded execution log.
839 This new recording method can be enabled using:
843 The "record-btrace" target is only available on Intel Atom processors
844 and requires a Linux kernel 2.6.32 or later.
846 * Two new commands have been added for record/replay to give information
847 about the recorded execution without having to replay the execution.
848 The commands are only supported by "record btrace".
850 record instruction-history prints the execution history at
851 instruction granularity
853 record function-call-history prints the execution history at
856 * New native configurations
858 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
859 FreeBSD/powerpc powerpc*-*-freebsd
860 x86_64/Cygwin x86_64-*-cygwin*
861 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
865 ARM AArch64 aarch64*-*-elf
866 ARM AArch64 GNU/Linux aarch64*-*-linux
867 Lynx 178 PowerPC powerpc-*-lynx*178
868 x86_64/Cygwin x86_64-*-cygwin*
869 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
871 * If the configured location of system.gdbinit file (as given by the
872 --with-system-gdbinit option at configure time) is in the
873 data-directory (as specified by --with-gdb-datadir at configure
874 time) or in one of its subdirectories, then GDB will look for the
875 system-wide init file in the directory specified by the
876 --data-directory command-line option.
878 * New command line options:
880 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
881 other initialization files, unlike -nx which disables all of them.
883 * Removed command line options
885 -epoch This was used by the gdb mode in Epoch, an ancient fork of
888 * The 'ptype' and 'whatis' commands now accept an argument to control
891 * 'info proc' now works on some core files.
895 ** Vectors can be created with gdb.Type.vector.
897 ** Python's atexit.register now works in GDB.
899 ** Types can be pretty-printed via a Python API.
901 ** Python 3 is now supported (in addition to Python 2.4 or later)
903 ** New class gdb.Architecture exposes GDB's internal representation
904 of architecture in the Python API.
906 ** New method Frame.architecture returns the gdb.Architecture object
907 corresponding to the frame's architecture.
909 * New Python-based convenience functions:
911 ** $_memeq(buf1, buf2, length)
912 ** $_streq(str1, str2)
914 ** $_regex(str, regex)
916 * The 'cd' command now defaults to using '~' (the home directory) if not
919 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
920 default for GCC since November 2000.
922 * The command 'forward-search' can now be abbreviated as 'fo'.
924 * The command 'info tracepoints' can now display 'installed on target'
925 or 'not installed on target' for each non-pending location of tracepoint.
927 * New configure options
929 --enable-libmcheck/--disable-libmcheck
930 By default, development versions are built with -lmcheck on hosts
931 that support it, in order to help track memory corruption issues.
932 Release versions, on the other hand, are built without -lmcheck
933 by default. The --enable-libmcheck/--disable-libmcheck configure
934 options allow the user to override that default.
935 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
936 This configure option allows the user to build GDB with
937 libbabeltrace using which GDB can read Common Trace Format data.
939 * New commands (for set/show, see "New options" below)
942 Catch signals. This is similar to "handle", but allows commands and
943 conditions to be attached.
946 List the BFDs known to GDB.
948 python-interactive [command]
950 Start a Python interactive prompt, or evaluate the optional command
951 and print the result of expressions.
954 "py" is a new alias for "python".
956 enable type-printer [name]...
957 disable type-printer [name]...
958 Enable or disable type printers.
962 ** For the Renesas Super-H architecture, the "regs" command has been removed
963 (has been deprecated in GDB 7.5), and "info all-registers" should be used
968 set print type methods (on|off)
969 show print type methods
970 Control whether method declarations are displayed by "ptype".
971 The default is to show them.
973 set print type typedefs (on|off)
974 show print type typedefs
975 Control whether typedef definitions are displayed by "ptype".
976 The default is to show them.
978 set filename-display basename|relative|absolute
979 show filename-display
980 Control the way in which filenames is displayed.
981 The default is "relative", which preserves previous behavior.
983 set trace-buffer-size
984 show trace-buffer-size
985 Request target to change the size of trace buffer.
987 set remote trace-buffer-size-packet auto|on|off
988 show remote trace-buffer-size-packet
989 Control the use of the remote protocol `QTBuffer:size' packet.
993 Control display of debugging messages related to ARM AArch64.
996 set debug coff-pe-read
997 show debug coff-pe-read
998 Control display of debugging messages related to reading of COFF/PE
1003 Control display of debugging messages related to Mach-O symbols
1006 set debug notification
1007 show debug notification
1008 Control display of debugging info for async remote notification.
1012 ** Command parameter changes are now notified using new async record
1013 "=cmd-param-changed".
1014 ** Trace frame changes caused by command "tfind" are now notified using
1015 new async record "=traceframe-changed".
1016 ** The creation, deletion and modification of trace state variables
1017 are now notified using new async records "=tsv-created",
1018 "=tsv-deleted" and "=tsv-modified".
1019 ** The start and stop of process record are now notified using new
1020 async record "=record-started" and "=record-stopped".
1021 ** Memory changes are now notified using new async record
1023 ** The data-disassemble command response will include a "fullname" field
1024 containing the absolute file name when source has been requested.
1025 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1026 command, to allow pattern filling of memory areas.
1027 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1028 library load/unload events.
1029 ** The response to breakpoint commands and breakpoint async records
1030 includes an "installed" field containing a boolean state about each
1031 non-pending tracepoint location is whether installed on target or not.
1032 ** Output of the "-trace-status" command includes a "trace-file" field
1033 containing the name of the trace file being examined. This field is
1034 optional, and only present when examining a trace file.
1035 ** The "fullname" field is now always present along with the "file" field,
1036 even if the file cannot be found by GDB.
1038 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1039 You must have the LZMA library available when configuring GDB for this
1040 feature to be enabled. For more information, see:
1041 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1043 * New remote packets
1046 Set the size of trace buffer. The remote stub reports support for this
1047 packet to gdb's qSupported query.
1050 Enable Branch Trace Store (BTS)-based branch tracing for the current
1051 thread. The remote stub reports support for this packet to gdb's
1055 Disable branch tracing for the current thread. The remote stub reports
1056 support for this packet to gdb's qSupported query.
1059 Read the traced branches for the current thread. The remote stub
1060 reports support for this packet to gdb's qSupported query.
1062 *** Changes in GDB 7.5
1064 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1065 for more x32 ABI info.
1067 * GDB now supports access to MIPS DSP registers on Linux targets.
1069 * GDB now supports debugging microMIPS binaries.
1071 * The "info os" command on GNU/Linux can now display information on
1072 several new classes of objects managed by the operating system:
1073 "info os procgroups" lists process groups
1074 "info os files" lists file descriptors
1075 "info os sockets" lists internet-domain sockets
1076 "info os shm" lists shared-memory regions
1077 "info os semaphores" lists semaphores
1078 "info os msg" lists message queues
1079 "info os modules" lists loaded kernel modules
1081 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1082 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1083 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1084 options and inspect the probe arguments using the new $_probe_arg family
1085 of convenience variables. You can obtain more information about SystemTap
1086 in <http://sourceware.org/systemtap/>.
1088 * GDB now supports reversible debugging on ARM, it allows you to
1089 debug basic ARM and THUMB instructions, and provides
1090 record/replay support.
1092 * The option "symbol-reloading" has been deleted as it is no longer used.
1096 ** GDB commands implemented in Python can now be put in command class
1099 ** The "maint set python print-stack on|off" is now deleted.
1101 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1102 apply "flag enum"-style pretty-printing to any enum.
1104 ** gdb.lookup_symbol can now work when there is no current frame.
1106 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1107 the source at which the symbol was defined.
1109 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1110 method 'value'. The former indicates whether the symbol needs a
1111 frame in order to compute its value, and the latter computes the
1114 ** A new method 'referenced_value' on gdb.Value objects which can
1115 dereference pointer as well as C++ reference values.
1117 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1118 which return the global and static blocks (as gdb.Block objects),
1119 of the underlying symbol table, respectively.
1121 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1122 object associated with a PC value.
1124 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1125 of the address range occupied by code for the current source line.
1127 * Go language support.
1128 GDB now supports debugging programs written in the Go programming
1131 * GDBserver now supports stdio connections.
1132 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1134 * The binary "gdbtui" can no longer be built or installed.
1135 Use "gdb -tui" instead.
1137 * GDB will now print "flag" enums specially. A flag enum is one where
1138 all the enumerator values have no bits in common when pairwise
1139 "and"ed. When printing a value whose type is a flag enum, GDB will
1140 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1141 (gdb) print (enum E) 3
1144 * The filename part of a linespec will now match trailing components
1145 of a source file name. For example, "break gcc/expr.c:1000" will
1146 now set a breakpoint in build/gcc/expr.c, but not
1147 build/libcpp/expr.c.
1149 * The "info proc" and "generate-core-file" commands will now also
1150 work on remote targets connected to GDBserver on Linux.
1152 * The command "info catch" has been removed. It has been disabled
1153 since December 2007.
1155 * The "catch exception" and "catch assert" commands now accept
1156 a condition at the end of the command, much like the "break"
1157 command does. For instance:
1159 (gdb) catch exception Constraint_Error if Barrier = True
1161 Previously, it was possible to add a condition to such catchpoints,
1162 but it had to be done as a second step, after the catchpoint had been
1163 created, using the "condition" command.
1165 * The "info static-tracepoint-marker" command will now also work on
1166 native Linux targets with in-process agent.
1168 * GDB can now set breakpoints on inlined functions.
1170 * The .gdb_index section has been updated to include symbols for
1171 inlined functions. GDB will ignore older .gdb_index sections by
1172 default, which could cause symbol files to be loaded more slowly
1173 until their .gdb_index sections can be recreated. The new command
1174 "set use-deprecated-index-sections on" will cause GDB to use any older
1175 .gdb_index sections it finds. This will restore performance, but the
1176 ability to set breakpoints on inlined functions will be lost in symbol
1177 files with older .gdb_index sections.
1179 The .gdb_index section has also been updated to record more information
1180 about each symbol. This speeds up the "info variables", "info functions"
1181 and "info types" commands when used with programs having the .gdb_index
1182 section, as well as speeding up debugging with shared libraries using
1183 the .gdb_index section.
1185 * Ada support for GDB/MI Variable Objects has been added.
1187 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1192 ** New command -info-os is the MI equivalent of "info os".
1194 ** Output logs ("set logging" and related) now include MI output.
1198 ** "set use-deprecated-index-sections on|off"
1199 "show use-deprecated-index-sections on|off"
1200 Controls the use of deprecated .gdb_index sections.
1202 ** "catch load" and "catch unload" can be used to stop when a shared
1203 library is loaded or unloaded, respectively.
1205 ** "enable count" can be used to auto-disable a breakpoint after
1208 ** "info vtbl" can be used to show the virtual method tables for
1209 C++ and Java objects.
1211 ** "explore" and its sub commands "explore value" and "explore type"
1212 can be used to recursively explore values and types of
1213 expressions. These commands are available only if GDB is
1214 configured with '--with-python'.
1216 ** "info auto-load" shows status of all kinds of auto-loaded files,
1217 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1218 sequences of commands files, "info auto-load python-scripts"
1219 shows status of auto-loading Python script files,
1220 "info auto-load local-gdbinit" shows status of loading init file
1221 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1222 status of inferior specific thread debugging shared library loading.
1224 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1225 and "show auto-load-scripts" commands have been deprecated, use their
1226 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1227 and "show auto-load python-scripts" counterparts instead.
1229 ** "dprintf location,format,args..." creates a dynamic printf, which
1230 is basically a breakpoint that does a printf and immediately
1231 resumes your program's execution, so it is like a printf that you
1232 can insert dynamically at runtime instead of at compiletime.
1234 ** "set print symbol"
1236 Controls whether GDB attempts to display the symbol, if any,
1237 corresponding to addresses it prints. This defaults to "on", but
1238 you can set it to "off" to restore GDB's previous behavior.
1240 * Deprecated commands
1242 ** For the Renesas Super-H architecture, the "regs" command has been
1243 deprecated, and "info all-registers" should be used instead.
1247 Renesas RL78 rl78-*-elf
1248 HP OpenVMS ia64 ia64-hp-openvms*
1250 * GDBserver supports evaluation of breakpoint conditions. When
1251 support is advertised by GDBserver, GDB may be told to send the
1252 breakpoint conditions in bytecode form to GDBserver. GDBserver
1253 will only report the breakpoint trigger to GDB when its condition
1258 set mips compression
1259 show mips compression
1260 Select the compressed ISA encoding used in functions that have no symbol
1261 information available. The encoding can be set to either of:
1264 and is updated automatically from ELF file flags if available.
1266 set breakpoint condition-evaluation
1267 show breakpoint condition-evaluation
1268 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1269 GDBserver ("target"). Default option "auto" chooses the most efficient
1271 This option can improve debugger efficiency depending on the speed of the
1275 Disable auto-loading globally.
1278 Show auto-loading setting of all kinds of auto-loaded files.
1280 set auto-load gdb-scripts on|off
1281 show auto-load gdb-scripts
1282 Control auto-loading of GDB canned sequences of commands files.
1284 set auto-load python-scripts on|off
1285 show auto-load python-scripts
1286 Control auto-loading of Python script files.
1288 set auto-load local-gdbinit on|off
1289 show auto-load local-gdbinit
1290 Control loading of init file (.gdbinit) from current directory.
1292 set auto-load libthread-db on|off
1293 show auto-load libthread-db
1294 Control auto-loading of inferior specific thread debugging shared library.
1296 set auto-load scripts-directory <dir1>[:<dir2>...]
1297 show auto-load scripts-directory
1298 Set a list of directories from which to load auto-loaded scripts.
1299 Automatically loaded Python scripts and GDB scripts are located in one
1300 of the directories listed by this option.
1301 The delimiter (':' above) may differ according to the host platform.
1303 set auto-load safe-path <dir1>[:<dir2>...]
1304 show auto-load safe-path
1305 Set a list of directories from which it is safe to auto-load files.
1306 The delimiter (':' above) may differ according to the host platform.
1308 set debug auto-load on|off
1309 show debug auto-load
1310 Control display of debugging info for auto-loading the files above.
1312 set dprintf-style gdb|call|agent
1314 Control the way in which a dynamic printf is performed; "gdb"
1315 requests a GDB printf command, while "call" causes dprintf to call a
1316 function in the inferior. "agent" requests that the target agent
1317 (such as GDBserver) do the printing.
1319 set dprintf-function <expr>
1320 show dprintf-function
1321 set dprintf-channel <expr>
1322 show dprintf-channel
1323 Set the function and optional first argument to the call when using
1324 the "call" style of dynamic printf.
1326 set disconnected-dprintf on|off
1327 show disconnected-dprintf
1328 Control whether agent-style dynamic printfs continue to be in effect
1329 after GDB disconnects.
1331 * New configure options
1333 --with-auto-load-dir
1334 Configure default value for the 'set auto-load scripts-directory'
1335 setting above. It defaults to '$debugdir:$datadir/auto-load',
1336 $debugdir representing global debugging info directories (available
1337 via 'show debug-file-directory') and $datadir representing GDB's data
1338 directory (available via 'show data-directory').
1340 --with-auto-load-safe-path
1341 Configure default value for the 'set auto-load safe-path' setting
1342 above. It defaults to the --with-auto-load-dir setting.
1344 --without-auto-load-safe-path
1345 Set 'set auto-load safe-path' to '/', effectively disabling this
1348 * New remote packets
1350 z0/z1 conditional breakpoints extension
1352 The z0/z1 breakpoint insertion packets have been extended to carry
1353 a list of conditional expressions over to the remote stub depending on the
1354 condition evaluation mode. The use of this extension can be controlled
1355 via the "set remote conditional-breakpoints-packet" command.
1359 Specify the signals which the remote stub may pass to the debugged
1360 program without GDB involvement.
1362 * New command line options
1364 --init-command=FILE, -ix Like --command, -x but execute it
1365 before loading inferior.
1366 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1367 execute it before loading inferior.
1369 *** Changes in GDB 7.4
1371 * GDB now handles ambiguous linespecs more consistently; the existing
1372 FILE:LINE support has been expanded to other types of linespecs. A
1373 breakpoint will now be set on all matching locations in all
1374 inferiors, and locations will be added or removed according to
1377 * GDB now allows you to skip uninteresting functions and files when
1378 stepping with the "skip function" and "skip file" commands.
1380 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1381 and "show remote hardware-watchpoint-length-limit". These allows to
1382 set or show the maximum length limit (in bytes) of a remote
1383 target hardware watchpoint.
1385 This allows e.g. to use "unlimited" hardware watchpoints with the
1386 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1387 watchpoints are slower than real hardware watchpoints but are
1388 significantly faster than gdb software watchpoints.
1392 ** The register_pretty_printer function in module gdb.printing now takes
1393 an optional `replace' argument. If True, the new printer replaces any
1396 ** The "maint set python print-stack on|off" command has been
1397 deprecated and will be deleted in GDB 7.5.
1398 A new command: "set python print-stack none|full|message" has
1399 replaced it. Additionally, the default for "print-stack" is
1400 now "message", which just prints the error message without
1403 ** A prompt substitution hook (prompt_hook) is now available to the
1406 ** A new Python module, gdb.prompt has been added to the GDB Python
1407 modules library. This module provides functionality for
1408 escape sequences in prompts (used by set/show
1409 extended-prompt). These escape sequences are replaced by their
1410 corresponding value.
1412 ** Python commands and convenience-functions located in
1413 'data-directory'/python/gdb/command and
1414 'data-directory'/python/gdb/function are now automatically loaded
1417 ** Blocks now provide four new attributes. global_block and
1418 static_block will return the global and static blocks
1419 respectively. is_static and is_global are boolean attributes
1420 that indicate if the block is one of those two types.
1422 ** Symbols now provide the "type" attribute, the type of the symbol.
1424 ** The "gdb.breakpoint" function has been deprecated in favor of
1427 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1428 of a function. This class is based on the "finish" command
1429 available in the CLI.
1431 ** Type objects for struct and union types now allow access to
1432 the fields using standard Python dictionary (mapping) methods.
1433 For example, "some_type['myfield']" now works, as does
1434 "some_type.items()".
1436 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1439 ** A new function, "deep_items" has been added to the gdb.types
1440 module in the GDB Python modules library. This function returns
1441 an iterator over the fields of a struct or union type. Unlike
1442 the standard Python "iteritems" method, it will recursively traverse
1443 any anonymous fields.
1447 ** "*stopped" events can report several new "reason"s, such as
1450 ** Breakpoint changes are now notified using new async records, like
1451 "=breakpoint-modified".
1453 ** New command -ada-task-info.
1455 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1456 $sdir specifies the default system locations of shared libraries.
1457 $pdir specifies the directory where the libpthread used by the application
1460 GDB no longer looks in $sdir and $pdir after it has searched the directories
1461 mentioned in libthread-db-search-path. If you want to search those
1462 directories, they must be specified in libthread-db-search-path.
1463 The default value of libthread-db-search-path on GNU/Linux and Solaris
1464 systems is now "$sdir:$pdir".
1466 $pdir is not supported by gdbserver, it is currently ignored.
1467 $sdir is supported by gdbserver.
1469 * New configure option --with-iconv-bin.
1470 When using the internationalization support like the one in the GNU C
1471 library, GDB will invoke the "iconv" program to get a list of supported
1472 character sets. If this program lives in a non-standard location, one can
1473 use this option to specify where to find it.
1475 * When natively debugging programs on PowerPC BookE processors running
1476 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1477 watchpoints, which specify a mask in addition to an address to watch.
1478 The mask specifies that some bits of an address (the bits which are
1479 reset in the mask) should be ignored when matching the address accessed
1480 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1481 section in the user manual for more details.
1483 * The new option --once causes GDBserver to stop listening for connections once
1484 the first connection is made. The listening port used by GDBserver will
1485 become available after that.
1487 * New commands "info macros" and "alias" have been added.
1489 * New function parameters suffix @entry specifies value of function parameter
1490 at the time the function got called. Entry values are available only since
1496 "!" is now an alias of the "shell" command.
1497 Note that no space is needed between "!" and SHELL COMMAND.
1501 watch EXPRESSION mask MASK_VALUE
1502 The watch command now supports the mask argument which allows creation
1503 of masked watchpoints, if the current architecture supports this feature.
1505 info auto-load-scripts [REGEXP]
1506 This command was formerly named "maintenance print section-scripts".
1507 It is now generally useful and is no longer a maintenance-only command.
1509 info macro [-all] [--] MACRO
1510 The info macro command has new options `-all' and `--'. The first for
1511 printing all definitions of a macro. The second for explicitly specifying
1512 the end of arguments and the beginning of the macro name in case the macro
1513 name starts with a hyphen.
1515 collect[/s] EXPRESSIONS
1516 The tracepoint collect command now takes an optional modifier "/s"
1517 that directs it to dereference pointer-to-character types and
1518 collect the bytes of memory up to a zero byte. The behavior is
1519 similar to what you see when you use the regular print command on a
1520 string. An optional integer following the "/s" sets a bound on the
1521 number of bytes that will be collected.
1524 The trace start command now interprets any supplied arguments as a
1525 note to be recorded with the trace run, with an effect similar to
1526 setting the variable trace-notes.
1529 The trace stop command now interprets any arguments as a note to be
1530 mentioned along with the tstatus report that the trace was stopped
1531 with a command. The effect is similar to setting the variable
1534 * Tracepoints can now be enabled and disabled at any time after a trace
1535 experiment has been started using the standard "enable" and "disable"
1536 commands. It is now possible to start a trace experiment with no enabled
1537 tracepoints; GDB will display a warning, but will allow the experiment to
1538 begin, assuming that tracepoints will be enabled as needed while the trace
1541 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1542 locations with 4-byte instructions, when they were previously
1543 limited to locations with instructions of 5 bytes or longer.
1547 set debug dwarf2-read
1548 show debug dwarf2-read
1549 Turns on or off display of debugging messages related to reading
1550 DWARF debug info. The default is off.
1552 set debug symtab-create
1553 show debug symtab-create
1554 Turns on or off display of debugging messages related to symbol table
1555 creation. The default is off.
1558 show extended-prompt
1559 Set the GDB prompt, and allow escape sequences to be inserted to
1560 display miscellaneous information (see 'help set extended-prompt'
1561 for the list of sequences). This prompt (and any information
1562 accessed through the escape sequences) is updated every time the
1563 prompt is displayed.
1565 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1566 show print entry-values
1567 Set printing of frame argument values at function entry. In some cases
1568 GDB can determine the value of function argument which was passed by the
1569 function caller, even if the value was modified inside the called function.
1571 set debug entry-values
1572 show debug entry-values
1573 Control display of debugging info for determining frame argument values at
1574 function entry and virtual tail call frames.
1576 set basenames-may-differ
1577 show basenames-may-differ
1578 Set whether a source file may have multiple base names.
1579 (A "base name" is the name of a file with the directory part removed.
1580 Example: The base name of "/home/user/hello.c" is "hello.c".)
1581 If set, GDB will canonicalize file names (e.g., expand symlinks)
1582 before comparing them. Canonicalization is an expensive operation,
1583 but it allows the same file be known by more than one base name.
1584 If not set (the default), all source files are assumed to have just
1585 one base name, and gdb will do file name comparisons more efficiently.
1591 Set a user name and notes for the current and any future trace runs.
1592 This is useful for long-running and/or disconnected traces, to
1593 inform others (or yourself) as to who is running the trace, supply
1594 contact information, or otherwise explain what is going on.
1596 set trace-stop-notes
1597 show trace-stop-notes
1598 Set a note attached to the trace run, that is displayed when the
1599 trace has been stopped by a tstop command. This is useful for
1600 instance as an explanation, if you are stopping a trace run that was
1601 started by someone else.
1603 * New remote packets
1607 Dynamically enable a tracepoint in a started trace experiment.
1611 Dynamically disable a tracepoint in a started trace experiment.
1615 Set the user and notes of the trace run.
1619 Query the current status of a tracepoint.
1623 Query the minimum length of instruction at which a fast tracepoint may
1626 * Dcache size (number of lines) and line-size are now runtime-configurable
1627 via "set dcache line" and "set dcache line-size" commands.
1631 Texas Instruments TMS320C6x tic6x-*-*
1635 Renesas RL78 rl78-*-elf
1637 *** Changes in GDB 7.3.1
1639 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1641 *** Changes in GDB 7.3
1643 * GDB has a new command: "thread find [REGEXP]".
1644 It finds the thread id whose name, target id, or thread extra info
1645 matches the given regular expression.
1647 * The "catch syscall" command now works on mips*-linux* targets.
1649 * The -data-disassemble MI command now supports modes 2 and 3 for
1650 dumping the instruction opcodes.
1652 * New command line options
1654 -data-directory DIR Specify DIR as the "data-directory".
1655 This is mostly for testing purposes.
1657 * The "maint set python auto-load on|off" command has been renamed to
1658 "set auto-load-scripts on|off".
1660 * GDB has a new command: "set directories".
1661 It is like the "dir" command except that it replaces the
1662 source path list instead of augmenting it.
1664 * GDB now understands thread names.
1666 On GNU/Linux, "info threads" will display the thread name as set by
1667 prctl or pthread_setname_np.
1669 There is also a new command, "thread name", which can be used to
1670 assign a name internally for GDB to display.
1673 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1674 has been integrated into GDB.
1678 ** The function gdb.Write now accepts an optional keyword 'stream'.
1679 This keyword, when provided, will direct the output to either
1680 stdout, stderr, or GDB's logging output.
1682 ** Parameters can now be be sub-classed in Python, and in particular
1683 you may implement the get_set_doc and get_show_doc functions.
1684 This improves how Parameter set/show documentation is processed
1685 and allows for more dynamic content.
1687 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1688 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1689 have an is_valid method.
1691 ** Breakpoints can now be sub-classed in Python, and in particular
1692 you may implement a 'stop' function that is executed each time
1693 the inferior reaches that breakpoint.
1695 ** New function gdb.lookup_global_symbol looks up a global symbol.
1697 ** GDB values in Python are now callable if the value represents a
1698 function. For example, if 'some_value' represents a function that
1699 takes two integer parameters and returns a value, you can call
1700 that function like so:
1702 result = some_value (10,20)
1704 ** Module gdb.types has been added.
1705 It contains a collection of utilities for working with gdb.Types objects:
1706 get_basic_type, has_field, make_enum_dict.
1708 ** Module gdb.printing has been added.
1709 It contains utilities for writing and registering pretty-printers.
1710 New classes: PrettyPrinter, SubPrettyPrinter,
1711 RegexpCollectionPrettyPrinter.
1712 New function: register_pretty_printer.
1714 ** New commands "info pretty-printers", "enable pretty-printer" and
1715 "disable pretty-printer" have been added.
1717 ** gdb.parameter("directories") is now available.
1719 ** New function gdb.newest_frame returns the newest frame in the
1722 ** The gdb.InferiorThread class has a new "name" attribute. This
1723 holds the thread's name.
1725 ** Python Support for Inferior events.
1726 Python scripts can add observers to be notified of events
1727 occurring in the process being debugged.
1728 The following events are currently supported:
1729 - gdb.events.cont Continue event.
1730 - gdb.events.exited Inferior exited event.
1731 - gdb.events.stop Signal received, and Breakpoint hit events.
1735 ** GDB now puts template parameters in scope when debugging in an
1736 instantiation. For example, if you have:
1738 template<int X> int func (void) { return X; }
1740 then if you step into func<5>, "print X" will show "5". This
1741 feature requires proper debuginfo support from the compiler; it
1742 was added to GCC 4.5.
1744 ** The motion commands "next", "finish", "until", and "advance" now
1745 work better when exceptions are thrown. In particular, GDB will
1746 no longer lose control of the inferior; instead, the GDB will
1747 stop the inferior at the point at which the exception is caught.
1748 This functionality requires a change in the exception handling
1749 code that was introduced in GCC 4.5.
1751 * GDB now follows GCC's rules on accessing volatile objects when
1752 reading or writing target state during expression evaluation.
1753 One notable difference to prior behavior is that "print x = 0"
1754 no longer generates a read of x; the value of the assignment is
1755 now always taken directly from the value being assigned.
1757 * GDB now has some support for using labels in the program's source in
1758 linespecs. For instance, you can use "advance label" to continue
1759 execution to a label.
1761 * GDB now has support for reading and writing a new .gdb_index
1762 section. This section holds a fast index of DWARF debugging
1763 information and can be used to greatly speed up GDB startup and
1764 operation. See the documentation for `save gdb-index' for details.
1766 * The "watch" command now accepts an optional "-location" argument.
1767 When used, this causes GDB to watch the memory referred to by the
1768 expression. Such a watchpoint is never deleted due to it going out
1771 * GDB now supports thread debugging of core dumps on GNU/Linux.
1773 GDB now activates thread debugging using the libthread_db library
1774 when debugging GNU/Linux core dumps, similarly to when debugging
1775 live processes. As a result, when debugging a core dump file, GDB
1776 is now able to display pthread_t ids of threads. For example, "info
1777 threads" shows the same output as when debugging the process when it
1778 was live. In earlier releases, you'd see something like this:
1781 * 1 LWP 6780 main () at main.c:10
1783 While now you see this:
1786 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1788 It is also now possible to inspect TLS variables when debugging core
1791 When debugging a core dump generated on a machine other than the one
1792 used to run GDB, you may need to point GDB at the correct
1793 libthread_db library with the "set libthread-db-search-path"
1794 command. See the user manual for more details on this command.
1796 * When natively debugging programs on PowerPC BookE processors running
1797 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1798 which stop execution of the inferior whenever it executes an instruction
1799 at any address within the specified range. See the "PowerPC Embedded"
1800 section in the user manual for more details.
1802 * New features in the GDB remote stub, GDBserver
1804 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1805 and i686 LynxOS (version 5.x).
1807 ** GDBserver is now supported on Blackfin Linux.
1809 * New native configurations
1811 ia64 HP-UX ia64-*-hpux*
1815 Analog Devices, Inc. Blackfin Processor bfin-*
1817 * Ada task switching is now supported on sparc-elf targets when
1818 debugging a program using the Ravenscar Profile. For more information,
1819 see the "Tasking Support when using the Ravenscar Profile" section
1820 in the GDB user manual.
1822 * Guile support was removed.
1824 * New features in the GNU simulator
1826 ** The --map-info flag lists all known core mappings.
1828 ** CFI flashes may be simulated via the "cfi" device.
1830 *** Changes in GDB 7.2
1832 * Shared library support for remote targets by default
1834 When GDB is configured for a generic, non-OS specific target, like
1835 for example, --target=arm-eabi or one of the many *-*-elf targets,
1836 GDB now queries remote stubs for loaded shared libraries using the
1837 `qXfer:libraries:read' packet. Previously, shared library support
1838 was always disabled for such configurations.
1842 ** Argument Dependent Lookup (ADL)
1844 In C++ ADL lookup directs function search to the namespaces of its
1845 arguments even if the namespace has not been imported.
1855 Here the compiler will search for `foo' in the namespace of 'b'
1856 and find A::foo. GDB now supports this. This construct is commonly
1857 used in the Standard Template Library for operators.
1859 ** Improved User Defined Operator Support
1861 In addition to member operators, GDB now supports lookup of operators
1862 defined in a namespace and imported with a `using' directive, operators
1863 defined in the global scope, operators imported implicitly from an
1864 anonymous namespace, and the ADL operators mentioned in the previous
1866 GDB now also supports proper overload resolution for all the previously
1867 mentioned flavors of operators.
1869 ** static const class members
1871 Printing of static const class members that are initialized in the
1872 class definition has been fixed.
1874 * Windows Thread Information Block access.
1876 On Windows targets, GDB now supports displaying the Windows Thread
1877 Information Block (TIB) structure. This structure is visible either
1878 by using the new command `info w32 thread-information-block' or, by
1879 dereferencing the new convenience variable named `$_tlb', a
1880 thread-specific pointer to the TIB. This feature is also supported
1881 when remote debugging using GDBserver.
1883 * Static tracepoints
1885 Static tracepoints are calls in the user program into a tracing
1886 library. One such library is a port of the LTTng kernel tracer to
1887 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1888 When debugging with GDBserver, GDB now supports combining the GDB
1889 tracepoint machinery with such libraries. For example: the user can
1890 use GDB to probe a static tracepoint marker (a call from the user
1891 program into the tracing library) with the new "strace" command (see
1892 "New commands" below). This creates a "static tracepoint" in the
1893 breakpoint list, that can be manipulated with the same feature set
1894 as fast and regular tracepoints. E.g., collect registers, local and
1895 global variables, collect trace state variables, and define
1896 tracepoint conditions. In addition, the user can collect extra
1897 static tracepoint marker specific data, by collecting the new
1898 $_sdata internal variable. When analyzing the trace buffer, you can
1899 inspect $_sdata like any other variable available to GDB. For more
1900 information, see the "Tracepoints" chapter in GDB user manual. New
1901 remote packets have been defined to support static tracepoints, see
1902 the "New remote packets" section below.
1904 * Better reconstruction of tracepoints after disconnected tracing
1906 GDB will attempt to download the original source form of tracepoint
1907 definitions when starting a trace run, and then will upload these
1908 upon reconnection to the target, resulting in a more accurate
1909 reconstruction of the tracepoints that are in use on the target.
1913 You can now exercise direct control over the ways that GDB can
1914 affect your program. For instance, you can disallow the setting of
1915 breakpoints, so that the program can run continuously (assuming
1916 non-stop mode). In addition, the "observer" variable is available
1917 to switch all of the different controls; in observer mode, GDB
1918 cannot affect the target's behavior at all, which is useful for
1919 tasks like diagnosing live systems in the field.
1921 * The new convenience variable $_thread holds the number of the
1924 * New remote packets
1928 Return the address of the Windows Thread Information Block of a given thread.
1932 In response to several of the tracepoint packets, the target may now
1933 also respond with a number of intermediate `qRelocInsn' request
1934 packets before the final result packet, to have GDB handle
1935 relocating an instruction to execute at a different address. This
1936 is particularly useful for stubs that support fast tracepoints. GDB
1937 reports support for this feature in the qSupported packet.
1941 List static tracepoint markers in the target program.
1945 List static tracepoint markers at a given address in the target
1948 qXfer:statictrace:read
1950 Read the static trace data collected (by a `collect $_sdata'
1951 tracepoint action). The remote stub reports support for this packet
1952 to gdb's qSupported query.
1956 Send the current settings of GDB's permission flags.
1960 Send part of the source (textual) form of a tracepoint definition,
1961 which includes location, conditional, and action list.
1963 * The source command now accepts a -s option to force searching for the
1964 script in the source search path even if the script name specifies
1967 * New features in the GDB remote stub, GDBserver
1969 - GDBserver now support tracepoints (including fast tracepoints, and
1970 static tracepoints). The feature is currently supported by the
1971 i386-linux and amd64-linux builds. See the "Tracepoints support
1972 in gdbserver" section in the manual for more information.
1974 GDBserver JIT compiles the tracepoint's conditional agent
1975 expression bytecode into native code whenever possible for low
1976 overhead dynamic tracepoints conditionals. For such tracepoints,
1977 an expression that examines program state is evaluated when the
1978 tracepoint is reached, in order to determine whether to capture
1979 trace data. If the condition is simple and false, processing the
1980 tracepoint finishes very quickly and no data is gathered.
1982 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1983 for static tracepoints support.
1985 - GDBserver now supports x86_64 Windows 64-bit debugging.
1987 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1988 it understands register description.
1990 * The --batch flag now disables pagination and queries.
1992 * X86 general purpose registers
1994 GDB now supports reading/writing byte, word and double-word x86
1995 general purpose registers directly. This means you can use, say,
1996 $ah or $ax to refer, respectively, to the byte register AH and
1997 16-bit word register AX that are actually portions of the 32-bit
1998 register EAX or 64-bit register RAX.
2000 * The `commands' command now accepts a range of breakpoints to modify.
2001 A plain `commands' following a command that creates multiple
2002 breakpoints affects all the breakpoints set by that command. This
2003 applies to breakpoints set by `rbreak', and also applies when a
2004 single `break' command creates multiple breakpoints (e.g.,
2005 breakpoints on overloaded c++ functions).
2007 * The `rbreak' command now accepts a filename specification as part of
2008 its argument, limiting the functions selected by the regex to those
2009 in the specified file.
2011 * Support for remote debugging Windows and SymbianOS shared libraries
2012 from Unix hosts has been improved. Non Windows GDB builds now can
2013 understand target reported file names that follow MS-DOS based file
2014 system semantics, such as file names that include drive letters and
2015 use the backslash character as directory separator. This makes it
2016 possible to transparently use the "set sysroot" and "set
2017 solib-search-path" on Unix hosts to point as host copies of the
2018 target's shared libraries. See the new command "set
2019 target-file-system-kind" described below, and the "Commands to
2020 specify files" section in the user manual for more information.
2024 eval template, expressions...
2025 Convert the values of one or more expressions under the control
2026 of the string template to a command line, and call it.
2028 set target-file-system-kind unix|dos-based|auto
2029 show target-file-system-kind
2030 Set or show the assumed file system kind for target reported file
2033 save breakpoints <filename>
2034 Save all current breakpoint definitions to a file suitable for use
2035 in a later debugging session. To read the saved breakpoint
2036 definitions, use the `source' command.
2038 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2041 info static-tracepoint-markers
2042 Display information about static tracepoint markers in the target.
2044 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2045 Define a static tracepoint by probing a marker at the given
2046 function, line, address, or marker ID.
2050 Enable and disable observer mode.
2052 set may-write-registers on|off
2053 set may-write-memory on|off
2054 set may-insert-breakpoints on|off
2055 set may-insert-tracepoints on|off
2056 set may-insert-fast-tracepoints on|off
2057 set may-interrupt on|off
2058 Set individual permissions for GDB effects on the target. Note that
2059 some of these settings can have undesirable or surprising
2060 consequences, particularly when changed in the middle of a session.
2061 For instance, disabling the writing of memory can prevent
2062 breakpoints from being inserted, cause single-stepping to fail, or
2063 even crash your program, if you disable after breakpoints have been
2064 inserted. However, GDB should not crash.
2066 set record memory-query on|off
2067 show record memory-query
2068 Control whether to stop the inferior if memory changes caused
2069 by an instruction cannot be recorded.
2074 The disassemble command now supports "start,+length" form of two arguments.
2078 ** GDB now provides a new directory location, called the python directory,
2079 where Python scripts written for GDB can be installed. The location
2080 of that directory is <data-directory>/python, where <data-directory>
2081 is the GDB data directory. For more details, see section `Scripting
2082 GDB using Python' in the manual.
2084 ** The GDB Python API now has access to breakpoints, symbols, symbol
2085 tables, program spaces, inferiors, threads and frame's code blocks.
2086 Additionally, GDB Parameters can now be created from the API, and
2087 manipulated via set/show in the CLI.
2089 ** New functions gdb.target_charset, gdb.target_wide_charset,
2090 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2092 ** New exception gdb.GdbError.
2094 ** Pretty-printers are now also looked up in the current program space.
2096 ** Pretty-printers can now be individually enabled and disabled.
2098 ** GDB now looks for names of Python scripts to auto-load in a
2099 special section named `.debug_gdb_scripts', in addition to looking
2100 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2102 * Tracepoint actions were unified with breakpoint commands. In particular,
2103 there are no longer differences in "info break" output for breakpoints and
2104 tracepoints and the "commands" command can be used for both tracepoints and
2105 regular breakpoints.
2109 ARM Symbian arm*-*-symbianelf*
2111 * D language support.
2112 GDB now supports debugging programs written in the D programming
2115 * GDB now supports the extended ptrace interface for PowerPC which is
2116 available since Linux kernel version 2.6.34. This automatically enables
2117 any hardware breakpoints and additional hardware watchpoints available in
2118 the processor. The old ptrace interface exposes just one hardware
2119 watchpoint and no hardware breakpoints.
2121 * GDB is now able to use the Data Value Compare (DVC) register available on
2122 embedded PowerPC processors to implement in hardware simple watchpoint
2123 conditions of the form:
2125 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2127 This works in native GDB running on Linux kernels with the extended ptrace
2128 interface mentioned above.
2130 *** Changes in GDB 7.1
2134 ** Namespace Support
2136 GDB now supports importing of namespaces in C++. This enables the
2137 user to inspect variables from imported namespaces. Support for
2138 namepace aliasing has also been added. So, if a namespace is
2139 aliased in the current scope (e.g. namepace C=A; ) the user can
2140 print variables using the alias (e.g. (gdb) print C::x).
2144 All known bugs relating to the printing of virtual base class were
2145 fixed. It is now possible to call overloaded static methods using a
2150 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2151 and reinterpret_cast<> are now handled by the C++ expression parser.
2155 Xilinx MicroBlaze microblaze-*-*
2160 Xilinx MicroBlaze microblaze
2163 * Multi-program debugging.
2165 GDB now has support for multi-program (a.k.a. multi-executable or
2166 multi-exec) debugging. This allows for debugging multiple inferiors
2167 simultaneously each running a different program under the same GDB
2168 session. See "Debugging Multiple Inferiors and Programs" in the
2169 manual for more information. This implied some user visible changes
2170 in the multi-inferior support. For example, "info inferiors" now
2171 lists inferiors that are not running yet or that have exited
2172 already. See also "New commands" and "New options" below.
2174 * New tracing features
2176 GDB's tracepoint facility now includes several new features:
2178 ** Trace state variables
2180 GDB tracepoints now include support for trace state variables, which
2181 are variables managed by the target agent during a tracing
2182 experiment. They are useful for tracepoints that trigger each
2183 other, so for instance one tracepoint can count hits in a variable,
2184 and then a second tracepoint has a condition that is true when the
2185 count reaches a particular value. Trace state variables share the
2186 $-syntax of GDB convenience variables, and can appear in both
2187 tracepoint actions and condition expressions. Use the "tvariable"
2188 command to create, and "info tvariables" to view; see "Trace State
2189 Variables" in the manual for more detail.
2193 GDB now includes an option for defining fast tracepoints, which
2194 targets may implement more efficiently, such as by installing a jump
2195 into the target agent rather than a trap instruction. The resulting
2196 speedup can be by two orders of magnitude or more, although the
2197 tradeoff is that some program locations on some target architectures
2198 might not allow fast tracepoint installation, for instance if the
2199 instruction to be replaced is shorter than the jump. To request a
2200 fast tracepoint, use the "ftrace" command, with syntax identical to
2201 the regular trace command.
2203 ** Disconnected tracing
2205 It is now possible to detach GDB from the target while it is running
2206 a trace experiment, then reconnect later to see how the experiment
2207 is going. In addition, a new variable disconnected-tracing lets you
2208 tell the target agent whether to continue running a trace if the
2209 connection is lost unexpectedly.
2213 GDB now has the ability to save the trace buffer into a file, and
2214 then use that file as a target, similarly to you can do with
2215 corefiles. You can select trace frames, print data that was
2216 collected in them, and use tstatus to display the state of the
2217 tracing run at the moment that it was saved. To create a trace
2218 file, use "tsave <filename>", and to use it, do "target tfile
2221 ** Circular trace buffer
2223 You can ask the target agent to handle the trace buffer as a
2224 circular buffer, discarding the oldest trace frames to make room for
2225 newer ones, by setting circular-trace-buffer to on. This feature may
2226 not be available for all target agents.
2231 The disassemble command, when invoked with two arguments, now requires
2232 the arguments to be comma-separated.
2235 The info variables command now displays variable definitions. Files
2236 which only declare a variable are not shown.
2239 The source command is now capable of sourcing Python scripts.
2240 This feature is dependent on the debugger being build with Python
2243 Related to this enhancement is also the introduction of a new command
2244 "set script-extension" (see below).
2246 * New commands (for set/show, see "New options" below)
2248 record save [<FILENAME>]
2249 Save a file (in core file format) containing the process record
2250 execution log for replay debugging at a later time.
2252 record restore <FILENAME>
2253 Restore the process record execution log that was saved at an
2254 earlier time, for replay debugging.
2256 add-inferior [-copies <N>] [-exec <FILENAME>]
2259 clone-inferior [-copies <N>] [ID]
2260 Make a new inferior ready to execute the same program another
2261 inferior has loaded.
2266 maint info program-spaces
2267 List the program spaces loaded into GDB.
2269 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2270 show remote interrupt-sequence
2271 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2272 as the sequence to the remote target in order to interrupt the execution.
2273 Ctrl-C is a default. Some system prefers BREAK which is high level of
2274 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2275 Magic SysRq g. It is BREAK signal and character 'g'.
2277 set remote interrupt-on-connect [on | off]
2278 show remote interrupt-on-connect
2279 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2280 remote target when gdb connects to it. This is needed when you debug
2283 set remotebreak [on | off]
2285 Deprecated. Use "set/show remote interrupt-sequence" instead.
2287 tvariable $NAME [ = EXP ]
2288 Create or modify a trace state variable.
2291 List trace state variables and their values.
2293 delete tvariable $NAME ...
2294 Delete one or more trace state variables.
2297 Evaluate the given expressions without collecting anything into the
2298 trace buffer. (Valid in tracepoint actions only.)
2300 ftrace FN / FILE:LINE / *ADDR
2301 Define a fast tracepoint at the given function, line, or address.
2303 * New expression syntax
2305 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2306 GDB now parses 0b101010 identically with 42.
2310 set follow-exec-mode new|same
2311 show follow-exec-mode
2312 Control whether GDB reuses the same inferior across an exec call or
2313 creates a new one. This is useful to be able to restart the old
2314 executable after the inferior having done an exec call.
2316 set default-collect EXPR, ...
2317 show default-collect
2318 Define a list of expressions to be collected at each tracepoint.
2319 This is a useful way to ensure essential items are not overlooked,
2320 such as registers or a critical global variable.
2322 set disconnected-tracing
2323 show disconnected-tracing
2324 If set to 1, the target is instructed to continue tracing if it
2325 loses its connection to GDB. If 0, the target is to stop tracing
2328 set circular-trace-buffer
2329 show circular-trace-buffer
2330 If set to on, the target is instructed to use a circular trace buffer
2331 and discard the oldest trace frames instead of stopping the trace due
2332 to a full trace buffer. If set to off, the trace stops when the buffer
2333 fills up. Some targets may not support this.
2335 set script-extension off|soft|strict
2336 show script-extension
2337 If set to "off", the debugger does not perform any script language
2338 recognition, and all sourced files are assumed to be GDB scripts.
2339 If set to "soft" (the default), files are sourced according to
2340 filename extension, falling back to GDB scripts if the first
2342 If set to "strict", files are sourced according to filename extension.
2344 set ada trust-PAD-over-XVS on|off
2345 show ada trust-PAD-over-XVS
2346 If off, activate a workaround against a bug in the debugging information
2347 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2348 the GCC sources for more information about the GNAT encoding and
2349 PAD types in particular). It is always safe to set this option to
2350 off, but this introduces a slight performance penalty. The default
2353 * Python API Improvements
2355 ** GDB provides the new class gdb.LazyString. This is useful in
2356 some pretty-printing cases. The new method gdb.Value.lazy_string
2357 provides a simple way to create objects of this type.
2359 ** The fields returned by gdb.Type.fields now have an
2360 `is_base_class' attribute.
2362 ** The new method gdb.Type.range returns the range of an array type.
2364 ** The new method gdb.parse_and_eval can be used to parse and
2365 evaluate an expression.
2367 * New remote packets
2370 Define a trace state variable.
2373 Get the current value of a trace state variable.
2376 Set desired tracing behavior upon disconnection.
2379 Set the trace buffer to be linear or circular.
2382 Get data about the tracepoints currently in use.
2386 Process record now works correctly with hardware watchpoints.
2388 Multiple bug fixes have been made to the mips-irix port, making it
2389 much more reliable. In particular:
2390 - Debugging threaded applications is now possible again. Previously,
2391 GDB would hang while starting the program, or while waiting for
2392 the program to stop at a breakpoint.
2393 - Attaching to a running process no longer hangs.
2394 - An error occurring while loading a core file has been fixed.
2395 - Changing the value of the PC register now works again. This fixes
2396 problems observed when using the "jump" command, or when calling
2397 a function from GDB, or even when assigning a new value to $pc.
2398 - With the "finish" and "return" commands, the return value for functions
2399 returning a small array is now correctly printed.
2400 - It is now possible to break on shared library code which gets executed
2401 during a shared library init phase (code executed while executing
2402 their .init section). Previously, the breakpoint would have no effect.
2403 - GDB is now able to backtrace through the signal handler for
2404 non-threaded programs.
2406 PIE (Position Independent Executable) programs debugging is now supported.
2407 This includes debugging execution of PIC (Position Independent Code) shared
2408 libraries although for that, it should be possible to run such libraries as an
2411 *** Changes in GDB 7.0
2413 * GDB now has an interface for JIT compilation. Applications that
2414 dynamically generate code can create symbol files in memory and register
2415 them with GDB. For users, the feature should work transparently, and
2416 for JIT developers, the interface is documented in the GDB manual in the
2417 "JIT Compilation Interface" chapter.
2419 * Tracepoints may now be conditional. The syntax is as for
2420 breakpoints; either an "if" clause appended to the "trace" command,
2421 or the "condition" command is available. GDB sends the condition to
2422 the target for evaluation using the same bytecode format as is used
2423 for tracepoint actions.
2425 * The disassemble command now supports: an optional /r modifier, print the
2426 raw instructions in hex as well as in symbolic form, and an optional /m
2427 modifier to print mixed source+assembly.
2429 * Process record and replay
2431 In a architecture environment that supports ``process record and
2432 replay'', ``process record and replay'' target can record a log of
2433 the process execution, and replay it with both forward and reverse
2436 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2437 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2438 set execution-direction {forward|reverse}, for targets that support
2441 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2442 feature is available with a native GDB running on kernel version
2445 * GDB now has support for multi-byte and wide character sets on the
2446 target. Strings whose character type is wchar_t, char16_t, or
2447 char32_t are now correctly printed. GDB supports wide- and unicode-
2448 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2449 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2450 `printf'. This feature requires iconv to work properly; if your
2451 system does not have a working iconv, GDB can use GNU libiconv. See
2452 the installation instructions for more information.
2454 * GDB now supports automatic retrieval of shared library files from
2455 remote targets. To use this feature, specify a system root that begins
2456 with the `remote:' prefix, either via the `set sysroot' command or via
2457 the `--with-sysroot' configure-time option.
2459 * "info sharedlibrary" now takes an optional regex of libraries to show,
2460 and it now reports if a shared library has no debugging information.
2462 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2463 now complete on file names.
2465 * When completing in expressions, gdb will attempt to limit
2466 completions to allowable structure or union fields, where appropriate.
2467 For instance, consider:
2469 # struct example { int f1; double f2; };
2470 # struct example variable;
2473 If the user types TAB at the end of this command line, the available
2474 completions will be "f1" and "f2".
2476 * Inlined functions are now supported. They show up in backtraces, and
2477 the "step", "next", and "finish" commands handle them automatically.
2479 * GDB now supports the token-splicing (##) and stringification (#)
2480 operators when expanding macros. It also supports variable-arity
2483 * GDB now supports inspecting extra signal information, exported by
2484 the new $_siginfo convenience variable. The feature is currently
2485 implemented on linux ARM, i386 and amd64.
2487 * GDB can now display the VFP floating point registers and NEON vector
2488 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2489 can provide these registers (requires Linux 2.6.30 or later). Remote
2490 and simulator targets may also provide them.
2492 * New remote packets
2495 Search memory for a sequence of bytes.
2498 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2499 operation over reliable transport links. Use of this packet is
2500 controlled by the `set remote noack-packet' command.
2503 Kill the process with the specified process ID. Use this in preference
2504 to `k' when multiprocess protocol extensions are supported.
2507 Obtains additional operating system information
2511 Read or write additional signal information.
2513 * Removed remote protocol undocumented extension
2515 An undocumented extension to the remote protocol's `S' stop reply
2516 packet that permited the stub to pass a process id was removed.
2517 Remote servers should use the `T' stop reply packet instead.
2519 * GDB now supports multiple function calling conventions according to the
2520 DWARF-2 DW_AT_calling_convention function attribute.
2522 * The SH target utilizes the aforementioned change to distinguish between gcc
2523 and Renesas calling convention. It also adds the new CLI commands
2524 `set/show sh calling-convention'.
2526 * GDB can now read compressed debug sections, as produced by GNU gold
2527 with the --compress-debug-sections=zlib flag.
2529 * 64-bit core files are now supported on AIX.
2531 * Thread switching is now supported on Tru64.
2533 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2534 which will be allocated using malloc later in program execution.
2536 * The qXfer:libraries:read remote procotol packet now allows passing a
2537 list of section offsets.
2539 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2540 conditions handling signals delivered during attach or thread creation
2541 have also been fixed.
2543 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2544 From the user's standpoint, all unqualified instances of True and False
2545 are treated as the standard definitions, regardless of context.
2547 * GDB now parses C++ symbol and type names more flexibly. For
2550 template<typename T> class C { };
2553 GDB will now correctly handle all of:
2555 ptype C<char const *>
2556 ptype C<char const*>
2557 ptype C<const char *>
2558 ptype C<const char*>
2560 * New features in the GDB remote stub, gdbserver
2562 - The "--wrapper" command-line argument tells gdbserver to use a
2563 wrapper program to launch programs for debugging.
2565 - On PowerPC and S/390 targets, it is now possible to use a single
2566 gdbserver executable to debug both 32-bit and 64-bit programs.
2567 (This requires gdbserver itself to be built as a 64-bit executable.)
2569 - gdbserver uses the new noack protocol mode for TCP connections to
2570 reduce communications latency, if also supported and enabled in GDB.
2572 - Support for the sparc64-linux-gnu target is now included in
2575 - The amd64-linux build of gdbserver now supports debugging both
2576 32-bit and 64-bit programs.
2578 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2579 now support hardware watchpoints, and will use them automatically
2584 GDB now has support for scripting using Python. Whether this is
2585 available is determined at configure time.
2587 New GDB commands can now be written in Python.
2589 * Ada tasking support
2591 Ada tasks can now be inspected in GDB. The following commands have
2595 Print the list of Ada tasks.
2597 Print detailed information about task number N.
2599 Print the task number of the current task.
2601 Switch the context of debugging to task number N.
2603 * Support for user-defined prefixed commands. The "define" command can
2604 add new commands to existing prefixes, e.g. "target".
2606 * Multi-inferior, multi-process debugging.
2608 GDB now has generalized support for multi-inferior debugging. See
2609 "Debugging Multiple Inferiors" in the manual for more information.
2610 Although availability still depends on target support, the command
2611 set is more uniform now. The GNU/Linux specific multi-forks support
2612 has been migrated to this new framework. This implied some user
2613 visible changes; see "New commands" and also "Removed commands"
2616 * Target descriptions can now describe the target OS ABI. See the
2617 "Target Description Format" section in the user manual for more
2620 * Target descriptions can now describe "compatible" architectures
2621 to indicate that the target can execute applications for a different
2622 architecture in addition to those for the main target architecture.
2623 See the "Target Description Format" section in the user manual for
2626 * Multi-architecture debugging.
2628 GDB now includes general supports for debugging applications on
2629 hybrid systems that use more than one single processor architecture
2630 at the same time. Each such hybrid architecture still requires
2631 specific support to be added. The only hybrid architecture supported
2632 in this version of GDB is the Cell Broadband Engine.
2634 * GDB now supports integrated debugging of Cell/B.E. applications that
2635 use both the PPU and SPU architectures. To enable support for hybrid
2636 Cell/B.E. debugging, you need to configure GDB to support both the
2637 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2638 --enable-targets configure option.
2640 * Non-stop mode debugging.
2642 For some targets, GDB now supports an optional mode of operation in
2643 which you can examine stopped threads while other threads continue
2644 to execute freely. This is referred to as non-stop mode, with the
2645 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2646 section in the user manual for more information.
2648 To be able to support remote non-stop debugging, a remote stub needs
2649 to implement the non-stop mode remote protocol extensions, as
2650 described in the "Remote Non-Stop" section of the user manual. The
2651 GDB remote stub, gdbserver, has been adjusted to support these
2652 extensions on linux targets.
2654 * New commands (for set/show, see "New options" below)
2656 catch syscall [NAME(S) | NUMBER(S)]
2657 Catch system calls. Arguments, which should be names of system
2658 calls or their numbers, mean catch only those syscalls. Without
2659 arguments, every syscall will be caught. When the inferior issues
2660 any of the specified syscalls, GDB will stop and announce the system
2661 call, both when it is called and when its call returns. This
2662 feature is currently available with a native GDB running on the
2663 Linux Kernel, under the following architectures: x86, x86_64,
2664 PowerPC and PowerPC64.
2666 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2668 Search memory for a sequence of bytes.
2670 maint set python print-stack
2671 maint show python print-stack
2672 Show a stack trace when an error is encountered in a Python script.
2675 Invoke CODE by passing it to the Python interpreter.
2680 These allow macros to be defined, undefined, and listed
2684 Show operating system information about processes.
2687 List the inferiors currently under GDB's control.
2690 Switch focus to inferior number NUM.
2693 Detach from inferior number NUM.
2696 Kill inferior number NUM.
2700 set spu stop-on-load
2701 show spu stop-on-load
2702 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2704 set spu auto-flush-cache
2705 show spu auto-flush-cache
2706 Control whether to automatically flush the software-managed cache
2707 during Cell/B.E. debugging.
2709 set sh calling-convention
2710 show sh calling-convention
2711 Control the calling convention used when calling SH target functions.
2714 show debug timestamp
2715 Control display of timestamps with GDB debugging output.
2717 set disassemble-next-line
2718 show disassemble-next-line
2719 Control display of disassembled source lines or instructions when
2722 set remote noack-packet
2723 show remote noack-packet
2724 Set/show the use of remote protocol QStartNoAckMode packet. See above
2725 under "New remote packets."
2727 set remote query-attached-packet
2728 show remote query-attached-packet
2729 Control use of remote protocol `qAttached' (query-attached) packet.
2731 set remote read-siginfo-object
2732 show remote read-siginfo-object
2733 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2736 set remote write-siginfo-object
2737 show remote write-siginfo-object
2738 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2741 set remote reverse-continue
2742 show remote reverse-continue
2743 Control use of remote protocol 'bc' (reverse-continue) packet.
2745 set remote reverse-step
2746 show remote reverse-step
2747 Control use of remote protocol 'bs' (reverse-step) packet.
2749 set displaced-stepping
2750 show displaced-stepping
2751 Control displaced stepping mode. Displaced stepping is a way to
2752 single-step over breakpoints without removing them from the debuggee.
2753 Also known as "out-of-line single-stepping".
2756 show debug displaced
2757 Control display of debugging info for displaced stepping.
2759 maint set internal-error
2760 maint show internal-error
2761 Control what GDB does when an internal error is detected.
2763 maint set internal-warning
2764 maint show internal-warning
2765 Control what GDB does when an internal warning is detected.
2770 Use a wrapper program to launch programs for debugging.
2772 set multiple-symbols (all|ask|cancel)
2773 show multiple-symbols
2774 The value of this variable can be changed to adjust the debugger behavior
2775 when an expression or a breakpoint location contains an ambiguous symbol
2776 name (an overloaded function name, for instance).
2778 set breakpoint always-inserted
2779 show breakpoint always-inserted
2780 Keep breakpoints always inserted in the target, as opposed to inserting
2781 them when resuming the target, and removing them when the target stops.
2782 This option can improve debugger performance on slow remote targets.
2784 set arm fallback-mode (arm|thumb|auto)
2785 show arm fallback-mode
2786 set arm force-mode (arm|thumb|auto)
2788 These commands control how ARM GDB determines whether instructions
2789 are ARM or Thumb. The default for both settings is auto, which uses
2790 the current CPSR value for instructions without symbols; previous
2791 versions of GDB behaved as if "set arm fallback-mode arm".
2793 set disable-randomization
2794 show disable-randomization
2795 Standalone programs run with the virtual address space randomization enabled
2796 by default on some platforms. This option keeps the addresses stable across
2797 multiple debugging sessions.
2801 Control whether other threads are stopped or not when some thread hits
2806 Requests that asynchronous execution is enabled in the target, if available.
2807 In this case, it's possible to resume target in the background, and interact
2808 with GDB while the target is running. "show target-async" displays the
2809 current state of asynchronous execution of the target.
2811 set target-wide-charset
2812 show target-wide-charset
2813 The target-wide-charset is the name of the character set that GDB
2814 uses when printing characters whose type is wchar_t.
2816 set tcp auto-retry (on|off)
2818 set tcp connect-timeout
2819 show tcp connect-timeout
2820 These commands allow GDB to retry failed TCP connections to a remote stub
2821 with a specified timeout period; this is useful if the stub is launched
2822 in parallel with GDB but may not be ready to accept connections immediately.
2824 set libthread-db-search-path
2825 show libthread-db-search-path
2826 Control list of directories which GDB will search for appropriate
2829 set schedule-multiple (on|off)
2830 show schedule-multiple
2831 Allow GDB to resume all threads of all processes or only threads of
2832 the current process.
2836 Use more aggressive caching for accesses to the stack. This improves
2837 performance of remote debugging (particularly backtraces) without
2838 affecting correctness.
2840 set interactive-mode (on|off|auto)
2841 show interactive-mode
2842 Control whether GDB runs in interactive mode (on) or not (off).
2843 When in interactive mode, GDB waits for the user to answer all
2844 queries. Otherwise, GDB does not wait and assumes the default
2845 answer. When set to auto (the default), GDB determines which
2846 mode to use based on the stdin settings.
2851 For program forks, this is replaced by the new more generic `info
2852 inferiors' command. To list checkpoints, you can still use the
2853 `info checkpoints' command, which was an alias for the `info forks'
2857 Replaced by the new `inferior' command. To switch between
2858 checkpoints, you can still use the `restart' command, which was an
2859 alias for the `fork' command.
2862 This is removed, since some targets don't have a notion of
2863 processes. To switch between processes, you can still use the
2864 `inferior' command using GDB's own inferior number.
2867 For program forks, this is replaced by the new more generic `kill
2868 inferior' command. To delete a checkpoint, you can still use the
2869 `delete checkpoint' command, which was an alias for the `delete
2873 For program forks, this is replaced by the new more generic `detach
2874 inferior' command. To detach a checkpoint, you can still use the
2875 `detach checkpoint' command, which was an alias for the `detach
2878 * New native configurations
2880 x86/x86_64 Darwin i[34567]86-*-darwin*
2882 x86_64 MinGW x86_64-*-mingw*
2886 Lattice Mico32 lm32-*
2887 x86 DICOS i[34567]86-*-dicos*
2888 x86_64 DICOS x86_64-*-dicos*
2891 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2892 (mingw32ce) debugging.
2898 These commands were actually not implemented on any target.
2900 *** Changes in GDB 6.8
2902 * New native configurations
2904 NetBSD/hppa hppa*-*netbsd*
2905 Xtensa GNU/Linux xtensa*-*-linux*
2909 NetBSD/hppa hppa*-*-netbsd*
2910 Xtensa GNU/Lunux xtensa*-*-linux*
2912 * Change in command line behavior -- corefiles vs. process ids.
2914 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2915 attaching to process NUMBER fails, GDB no longer attempts to open a
2916 core file named NUMBER. Attaching to a program using the -c option
2917 is no longer supported. Instead, use the '-p' or '--pid' options.
2919 * GDB can now be built as a native debugger for debugging Windows x86
2920 (mingw32) Portable Executable (PE) programs.
2922 * Pending breakpoints no longer change their number when their address
2925 * GDB now supports breakpoints with multiple locations,
2926 including breakpoints on C++ constructors, inside C++ templates,
2927 and in inlined functions.
2929 * GDB's ability to debug optimized code has been improved. GDB more
2930 accurately identifies function bodies and lexical blocks that occupy
2931 more than one contiguous range of addresses.
2933 * Target descriptions can now describe registers for PowerPC.
2935 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2936 registers on PowerPC targets.
2938 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2939 targets even when the libthread_db library is not available.
2941 * The GDB remote stub, gdbserver, now supports the new file transfer
2942 commands (remote put, remote get, and remote delete).
2944 * The GDB remote stub, gdbserver, now supports run and attach in
2945 extended-remote mode.
2947 * hppa*64*-*-hpux11* target broken
2948 The debugger is unable to start a program and fails with the following
2949 error: "Error trying to get information about dynamic linker".
2950 The gdb-6.7 release is also affected.
2952 * GDB now supports the --enable-targets= configure option to allow
2953 building a single GDB executable that supports multiple remote
2954 target architectures.
2956 * GDB now supports debugging C and C++ programs which use the
2957 Decimal Floating Point extension. In addition, the PowerPC target
2958 now has a set of pseudo-registers to inspect decimal float values
2959 stored in two consecutive float registers.
2961 * The -break-insert MI command can optionally create pending
2964 * Improved support for debugging Ada
2965 Many improvements to the Ada language support have been made. These
2967 - Better support for Ada2005 interface types
2968 - Improved handling of arrays and slices in general
2969 - Better support for Taft-amendment types
2970 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2972 - Improved command completion in Ada
2975 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2980 set print frame-arguments (all|scalars|none)
2981 show print frame-arguments
2982 The value of this variable can be changed to control which argument
2983 values should be printed by the debugger when displaying a frame.
2988 Transfer files to and from a remote target, and delete remote files.
2995 Transfer files to and from a remote target, and delete remote files.
2997 * New remote packets
3004 Open, close, read, write, and delete files on the remote system.
3007 Attach to an existing process on the remote system, in extended-remote
3011 Run a new process on the remote system, in extended-remote mode.
3013 *** Changes in GDB 6.7
3015 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3016 bfd, libiberty and opcodes, as revealed by static analysis donated by
3017 Coverity, Inc. (http://scan.coverity.com).
3019 * When looking up multiply-defined global symbols, GDB will now prefer the
3020 symbol definition in the current shared library if it was built using the
3021 -Bsymbolic linker option.
3023 * When the Text User Interface (TUI) is not configured, GDB will now
3024 recognize the -tui command-line option and print a message that the TUI
3027 * The GDB remote stub, gdbserver, now has lower overhead for high
3028 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3030 * GDB for MIPS targets now autodetects whether a remote target provides
3031 32-bit or 64-bit register values.
3033 * Support for C++ member pointers has been improved.
3035 * GDB now understands XML target descriptions, which specify the
3036 target's overall architecture. GDB can read a description from
3037 a local file or over the remote serial protocol.
3039 * Vectors of single-byte data use a new integer type which is not
3040 automatically displayed as character or string data.
3042 * The /s format now works with the print command. It displays
3043 arrays of single-byte integers and pointers to single-byte integers
3046 * Target descriptions can now describe target-specific registers,
3047 for architectures which have implemented the support (currently
3048 only ARM, M68K, and MIPS).
3050 * GDB and the GDB remote stub, gdbserver, now support the XScale
3053 * The GDB remote stub, gdbserver, has been updated to support
3054 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3055 has been rewritten to use the standard GDB remote protocol.
3057 * GDB can now step into C++ functions which are called through thunks.
3059 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3061 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3062 layout. It also supports a TextSeg= and DataSeg= response when only
3063 segment base addresses (rather than offsets) are available.
3065 * The /i format now outputs any trailing branch delay slot instructions
3066 immediately following the last instruction within the count specified.
3068 * The GDB remote protocol "T" stop reply packet now supports a
3069 "library" response. Combined with the new "qXfer:libraries:read"
3070 packet, this response allows GDB to debug shared libraries on targets
3071 where the operating system manages the list of loaded libraries (e.g.
3072 Windows and SymbianOS).
3074 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3075 (DLLs) on Windows and Windows CE targets.
3077 * GDB now supports a faster verification that a .debug file matches its binary
3078 according to its build-id signature, if the signature is present.
3084 Enable or disable hardware flow control (RTS/CTS) on the serial port
3085 when debugging using remote targets.
3087 set mem inaccessible-by-default
3088 show mem inaccessible-by-default
3089 If the target supplies a memory map, for instance via the remote
3090 protocol's "qXfer:memory-map:read" packet, setting this variable
3091 prevents GDB from accessing memory outside the memory map. This
3092 is useful for targets with memory mapped registers or which react
3093 badly to accesses of unmapped address space.
3095 set breakpoint auto-hw
3096 show breakpoint auto-hw
3097 If the target supplies a memory map, for instance via the remote
3098 protocol's "qXfer:memory-map:read" packet, setting this variable
3099 lets GDB use hardware breakpoints automatically for memory regions
3100 where it can not use software breakpoints. This covers both the
3101 "break" command and internal breakpoints used for other commands
3102 including "next" and "finish".
3105 catch exception unhandled
3106 Stop the program execution when Ada exceptions are raised.
3109 Stop the program execution when an Ada assertion failed.
3113 Set an alternate system root for target files. This is a more
3114 general version of "set solib-absolute-prefix", which is now
3115 an alias to "set sysroot".
3118 Provide extended SPU facility status information. This set of
3119 commands is available only when debugging the Cell/B.E. SPU
3122 * New native configurations
3124 OpenBSD/sh sh*-*openbsd*
3127 unset tdesc filename
3129 Use the specified local file as an XML target description, and do
3130 not query the target for its built-in description.
3134 OpenBSD/sh sh*-*-openbsd*
3135 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3136 Toshiba Media Processor mep-elf
3138 * New remote packets
3141 Ignore the specified signals; pass them directly to the debugged program
3142 without stopping other threads or reporting them to GDB.
3144 qXfer:features:read:
3145 Read an XML target description from the target, which describes its
3150 Read or write contents of an spufs file on the target system. These
3151 packets are available only on the Cell/B.E. SPU architecture.
3153 qXfer:libraries:read:
3154 Report the loaded shared libraries. Combined with new "T" packet
3155 response, this packet allows GDB to debug shared libraries on
3156 targets where the operating system manages the list of loaded
3157 libraries (e.g. Windows and SymbianOS).
3161 Support for these obsolete configurations has been removed.
3169 i[34567]86-*-lynxos*
3170 i[34567]86-*-netware*
3171 i[34567]86-*-sco3.2v5*
3172 i[34567]86-*-sco3.2v4*
3174 i[34567]86-*-sysv4.2*
3177 i[34567]86-*-unixware2*
3178 i[34567]86-*-unixware*
3187 * Other removed features
3194 Various m68k-only ROM monitors.
3201 Various Renesas ROM monitors and debugging interfaces for SH and
3206 Support for a Macraigor serial interface to on-chip debugging.
3207 GDB does not directly support the newer parallel or USB
3212 A debug information format. The predecessor to DWARF 2 and
3213 DWARF 3, which are still supported.
3215 Support for the HP aCC compiler on HP-UX/PA-RISC
3217 SOM-encapsulated symbolic debugging information, automatic
3218 invocation of pxdb, and the aCC custom C++ ABI. This does not
3219 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3220 with aCC can still be debugged on an assembly level.
3222 MIPS ".pdr" sections
3224 A MIPS-specific format used to describe stack frame layout
3225 in debugging information.
3229 GDB could work with an older version of Guile to debug
3230 the interpreter and Scheme programs running in it.
3232 set mips stack-arg-size
3233 set mips saved-gpreg-size
3235 Use "set mips abi" to control parameter passing for MIPS.
3237 *** Changes in GDB 6.6
3242 Cell Broadband Engine SPU spu-elf
3244 * GDB can now be configured as a cross-debugger targeting native Windows
3245 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3246 running on a Windows system over TCP/IP to debug Windows programs.
3248 * The GDB remote stub, gdbserver, has been updated to support Windows and
3249 Cygwin debugging. Both single-threaded and multi-threaded programs are
3252 * The "set trust-readonly-sections" command works again. This command was
3253 broken in GDB 6.3, 6.4, and 6.5.
3255 * The "load" command now supports writing to flash memory, if the remote
3256 stub provides the required support.
3258 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3259 longer requires symbolic debug information (e.g. DWARF-2).
3264 unset substitute-path
3265 show substitute-path
3266 Manage a list of substitution rules that GDB uses to rewrite the name
3267 of the directories where the sources are located. This can be useful
3268 for instance when the sources were moved to a different location
3269 between compilation and debugging.
3273 Print each CLI command as it is executed. Each command is prefixed with
3274 a number of `+' symbols representing the nesting depth.
3275 The source command now has a `-v' option to enable the same feature.
3279 The ARM Demon monitor support (RDP protocol, "target rdp").
3281 Kernel Object Display, an embedded debugging feature which only worked with
3282 an obsolete version of Cisco IOS.
3284 The 'set download-write-size' and 'show download-write-size' commands.
3286 * New remote packets
3289 Tell a stub about GDB client features, and request remote target features.
3290 The first feature implemented is PacketSize, which allows the target to
3291 specify the size of packets it can handle - to minimize the number of
3292 packets required and improve performance when connected to a remote
3296 Fetch an OS auxilliary vector from the remote stub. This packet is a
3297 more efficient replacement for qPart:auxv:read.
3299 qXfer:memory-map:read:
3300 Fetch a memory map from the remote stub, including information about
3301 RAM, ROM, and flash memory devices.
3306 Erase and program a flash memory device.
3308 * Removed remote packets
3311 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3312 used it, and only gdbserver implemented it.
3314 *** Changes in GDB 6.5
3318 Renesas M32C/M16C m32c-elf
3320 Morpho Technologies ms1 ms1-elf
3324 init-if-undefined Initialize a convenience variable, but
3325 only if it doesn't already have a value.
3327 The following commands are presently only implemented for native GNU/Linux:
3329 checkpoint Save a snapshot of the program state.
3331 restart <n> Return the program state to a
3332 previously saved state.
3334 info checkpoints List currently saved checkpoints.
3336 delete-checkpoint <n> Delete a previously saved checkpoint.
3338 set|show detach-on-fork Tell gdb whether to detach from a newly
3339 forked process, or to keep debugging it.
3341 info forks List forks of the user program that
3342 are available to be debugged.
3344 fork <n> Switch to debugging one of several
3345 forks of the user program that are
3346 available to be debugged.
3348 delete-fork <n> Delete a fork from the list of forks
3349 that are available to be debugged (and
3350 kill the forked process).
3352 detach-fork <n> Delete a fork from the list of forks
3353 that are available to be debugged (and
3354 allow the process to continue).
3358 Morpho Technologies ms2 ms1-elf
3360 * Improved Windows host support
3362 GDB now builds as a cross debugger hosted on i686-mingw32, including
3363 native console support, and remote communications using either
3364 network sockets or serial ports.
3366 * Improved Modula-2 language support
3368 GDB can now print most types in the Modula-2 syntax. This includes:
3369 basic types, set types, record types, enumerated types, range types,
3370 pointer types and ARRAY types. Procedure var parameters are correctly
3371 printed and hexadecimal addresses and character constants are also
3372 written in the Modula-2 syntax. Best results can be obtained by using
3373 GNU Modula-2 together with the -gdwarf-2 command line option.
3377 The ARM rdi-share module.
3379 The Netware NLM debug server.
3381 *** Changes in GDB 6.4
3383 * New native configurations
3385 OpenBSD/arm arm*-*-openbsd*
3386 OpenBSD/mips64 mips64-*-openbsd*
3390 Morpho Technologies ms1 ms1-elf
3392 * New command line options
3394 --batch-silent As for --batch, but totally silent.
3395 --return-child-result The debugger will exist with the same value
3396 the child (debugged) program exited with.
3397 --eval-command COMMAND, -ex COMMAND
3398 Execute a single GDB CLI command. This may be
3399 specified multiple times and in conjunction
3400 with the --command (-x) option.
3402 * Deprecated commands removed
3404 The following commands, that were deprecated in 2000, have been
3408 set|show arm disassembly-flavor set|show arm disassembler
3409 othernames set arm disassembler
3410 set|show remotedebug set|show debug remote
3411 set|show archdebug set|show debug arch
3412 set|show eventdebug set|show debug event
3415 * New BSD user-level threads support
3417 It is now possible to debug programs using the user-level threads
3418 library on OpenBSD and FreeBSD. Currently supported (target)
3421 FreeBSD/amd64 x86_64-*-freebsd*
3422 FreeBSD/i386 i386-*-freebsd*
3423 OpenBSD/i386 i386-*-openbsd*
3425 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3426 are not yet supported.
3428 * New support for Matsushita MN10300 w/sim added
3429 (Work in progress). mn10300-elf.
3431 * REMOVED configurations and files
3433 VxWorks and the XDR protocol *-*-vxworks
3434 Motorola MCORE mcore-*-*
3435 National Semiconductor NS32000 ns32k-*-*
3437 * New "set print array-indexes" command
3439 After turning this setting "on", GDB prints the index of each element
3440 when displaying arrays. The default is "off" to preserve the previous
3443 * VAX floating point support
3445 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3447 * User-defined command support
3449 In addition to using $arg0..$arg9 for argument passing, it is now possible
3450 to use $argc to determine now many arguments have been passed. See the
3451 section on user-defined commands in the user manual for more information.
3453 *** Changes in GDB 6.3:
3455 * New command line option
3457 GDB now accepts -l followed by a number to set the timeout for remote
3460 * GDB works with GCC -feliminate-dwarf2-dups
3462 GDB now supports a more compact representation of DWARF-2 debug
3463 information using DW_FORM_ref_addr references. These are produced
3464 by GCC with the option -feliminate-dwarf2-dups and also by some
3465 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3466 to use -feliminate-dwarf2-dups.
3468 * Internationalization
3470 When supported by the host system, GDB will be built with
3471 internationalization (libintl). The task of marking up the sources is
3472 continued, we're looking forward to our first translation.
3476 Initial support for debugging programs compiled with the GNAT
3477 implementation of the Ada programming language has been integrated
3478 into GDB. In this release, support is limited to expression evaluation.
3480 * New native configurations
3482 GNU/Linux/m32r m32r-*-linux-gnu
3486 GDB's remote protocol now includes support for the 'p' packet. This
3487 packet is used to fetch individual registers from a remote inferior.
3489 * END-OF-LIFE registers[] compatibility module
3491 GDB's internal register infrastructure has been completely rewritten.
3492 The new infrastructure making possible the implementation of key new
3493 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3496 GDB 6.3 will be the last release to include the the registers[]
3497 compatibility module that allowed out-of-date configurations to
3498 continue to work. This change directly impacts the following
3508 powerpc bdm protocol
3510 Unless there is activity to revive these configurations, they will be
3511 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3513 * OBSOLETE configurations and files
3515 Configurations that have been declared obsolete in this release have
3516 been commented out. Unless there is activity to revive these
3517 configurations, the next release of GDB will have their sources
3518 permanently REMOVED.
3527 *** Changes in GDB 6.2.1:
3529 * MIPS `break main; run' gave an heuristic-fence-post warning
3531 When attempting to run even a simple program, a warning about
3532 heuristic-fence-post being hit would be reported. This problem has
3535 * MIPS IRIX 'long double' crashed GDB
3537 When examining a long double variable, GDB would get a segmentation
3538 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3539 IRIX long double values).
3543 A bug in the VAX stack code was causing problems with the "next"
3544 command. This problem has been fixed.
3546 *** Changes in GDB 6.2:
3548 * Fix for ``many threads''
3550 On GNU/Linux systems that use the NPTL threads library, a program
3551 rapidly creating and deleting threads would confuse GDB leading to the
3554 ptrace: No such process.
3555 thread_db_get_info: cannot get thread info: generic error
3557 This problem has been fixed.
3559 * "-async" and "-noasync" options removed.
3561 Support for the broken "-noasync" option has been removed (it caused
3564 * New ``start'' command.
3566 This command runs the program until the begining of the main procedure.
3568 * New BSD Kernel Data Access Library (libkvm) interface
3570 Using ``target kvm'' it is now possible to debug kernel core dumps and
3571 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3572 platforms. Currently supported (native-only) configurations are:
3574 FreeBSD/amd64 x86_64-*-freebsd*
3575 FreeBSD/i386 i?86-*-freebsd*
3576 NetBSD/i386 i?86-*-netbsd*
3577 NetBSD/m68k m68*-*-netbsd*
3578 NetBSD/sparc sparc-*-netbsd*
3579 OpenBSD/amd64 x86_64-*-openbsd*
3580 OpenBSD/i386 i?86-*-openbsd*
3581 OpenBSD/m68k m68*-openbsd*
3582 OpenBSD/sparc sparc-*-openbsd*
3584 * Signal trampoline code overhauled
3586 Many generic problems with GDB's signal handling code have been fixed.
3587 These include: backtraces through non-contiguous stacks; recognition
3588 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3589 call; backtrace through a signal trampoline; step into and out of
3590 signal handlers; and single-stepping in the signal trampoline.
3592 Please note that kernel bugs are a limiting factor here. These
3593 features have been shown to work on an s390 GNU/Linux system that
3594 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3596 * Cygwin support for DWARF 2 added.
3598 * New native configurations
3600 GNU/Linux/hppa hppa*-*-linux*
3601 OpenBSD/hppa hppa*-*-openbsd*
3602 OpenBSD/m68k m68*-*-openbsd*
3603 OpenBSD/m88k m88*-*-openbsd*
3604 OpenBSD/powerpc powerpc-*-openbsd*
3605 NetBSD/vax vax-*-netbsd*
3606 OpenBSD/vax vax-*-openbsd*
3608 * END-OF-LIFE frame compatibility module
3610 GDB's internal frame infrastructure has been completely rewritten.
3611 The new infrastructure making it possible to support key new features
3612 including DWARF 2 Call Frame Information. To aid in the task of
3613 migrating old configurations to this new infrastructure, a
3614 compatibility module, that allowed old configurations to continue to
3615 work, was also included.
3617 GDB 6.2 will be the last release to include this frame compatibility
3618 module. This change directly impacts the following configurations:
3628 Unless there is activity to revive these configurations, they will be
3629 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3631 * REMOVED configurations and files
3633 Sun 3, running SunOS 3 m68*-*-sunos3*
3634 Sun 3, running SunOS 4 m68*-*-sunos4*
3635 Sun 2, running SunOS 3 m68000-*-sunos3*
3636 Sun 2, running SunOS 4 m68000-*-sunos4*
3637 Motorola 680x0 running LynxOS m68*-*-lynxos*
3638 AT&T 3b1/Unix pc m68*-att-*
3639 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3640 decstation mips-dec-* mips-little-*
3641 riscos mips-*-riscos* mips-*-sysv*
3642 sonymips mips-sony-*
3643 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3645 *** Changes in GDB 6.1.1:
3647 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3649 The TUI (Text-mode User Interface) is now built as part of a default
3650 GDB configuration. It is enabled by either selecting the TUI with the
3651 command line option "-i=tui" or by running the separate "gdbtui"
3652 program. For more information on the TUI, see the manual "Debugging
3655 * Pending breakpoint support (also included in GDB 6.1)
3657 Support has been added to allow you to specify breakpoints in shared
3658 libraries that have not yet been loaded. If a breakpoint location
3659 cannot be found, and the "breakpoint pending" option is set to auto,
3660 GDB queries you if you wish to make the breakpoint pending on a future
3661 shared-library load. If and when GDB resolves the breakpoint symbol,
3662 the pending breakpoint is removed as one or more regular breakpoints
3665 Pending breakpoints are very useful for GCJ Java debugging.
3667 * Fixed ISO-C build problems
3669 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3670 non ISO-C code that stopped them being built using a more strict ISO-C
3671 compiler (e.g., IBM's C compiler).
3673 * Fixed build problem on IRIX 5
3675 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3676 wasn't able to compile compile on an IRIX 5 system.
3678 * Added execute permission to gdb/gdbserver/configure
3680 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3681 permission. This bug would cause configure to fail on a number of
3682 systems (Solaris, IRIX). Ref: server/519.
3684 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3686 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3687 has been updated to use constant array sizes.
3689 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3691 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3692 its generated DWARF Call Frame Info. This encoding was causing GDB to
3693 panic, that panic has been fixed. Ref: gdb/1628.
3695 * Fixed a problem when examining parameters in shared library code.
3697 When examining parameters in optimized shared library code generated
3698 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3699 not available''. GDB now correctly displays the variable's value.
3701 *** Changes in GDB 6.1:
3703 * Removed --with-mmalloc
3705 Support for the mmalloc memory manager has been removed, as it
3706 conflicted with the internal gdb byte cache.
3708 * Changes in AMD64 configurations
3710 The AMD64 target now includes the %cs and %ss registers. As a result
3711 the AMD64 remote protocol has changed; this affects the floating-point
3712 and SSE registers. If you rely on those registers for your debugging,
3713 you should upgrade gdbserver on the remote side.
3715 * Revised SPARC target
3717 The SPARC target has been completely revised, incorporating the
3718 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3719 support for LynxOS and SunOS 4 has been dropped. Calling functions
3720 from within GDB on operating systems with a non-executable stack
3721 (Solaris, OpenBSD) now works.
3725 GDB has a new C++ demangler which does a better job on the mangled
3726 names generated by current versions of g++. It also runs faster, so
3727 with this and other changes gdb should now start faster on large C++
3730 * DWARF 2 Location Expressions
3732 GDB support for location expressions has been extended to support function
3733 arguments and frame bases. Older versions of GDB could crash when they
3736 * C++ nested types and namespaces
3738 GDB's support for nested types and namespaces in C++ has been
3739 improved, especially if you use the DWARF 2 debugging format. (This
3740 is the default for recent versions of GCC on most platforms.)
3741 Specifically, if you have a class "Inner" defined within a class or
3742 namespace "Outer", then GDB realizes that the class's name is
3743 "Outer::Inner", not simply "Inner". This should greatly reduce the
3744 frequency of complaints about not finding RTTI symbols. In addition,
3745 if you are stopped at inside of a function defined within a namespace,
3746 GDB modifies its name lookup accordingly.
3748 * New native configurations
3750 NetBSD/amd64 x86_64-*-netbsd*
3751 OpenBSD/amd64 x86_64-*-openbsd*
3752 OpenBSD/alpha alpha*-*-openbsd*
3753 OpenBSD/sparc sparc-*-openbsd*
3754 OpenBSD/sparc64 sparc64-*-openbsd*
3756 * New debugging protocols
3758 M32R with SDI protocol m32r-*-elf*
3760 * "set prompt-escape-char" command deleted.
3762 The command "set prompt-escape-char" has been deleted. This command,
3763 and its very obscure effet on GDB's prompt, was never documented,
3764 tested, nor mentioned in the NEWS file.
3766 * OBSOLETE configurations and files
3768 Configurations that have been declared obsolete in this release have
3769 been commented out. Unless there is activity to revive these
3770 configurations, the next release of GDB will have their sources
3771 permanently REMOVED.
3773 Sun 3, running SunOS 3 m68*-*-sunos3*
3774 Sun 3, running SunOS 4 m68*-*-sunos4*
3775 Sun 2, running SunOS 3 m68000-*-sunos3*
3776 Sun 2, running SunOS 4 m68000-*-sunos4*
3777 Motorola 680x0 running LynxOS m68*-*-lynxos*
3778 AT&T 3b1/Unix pc m68*-att-*
3779 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3780 decstation mips-dec-* mips-little-*
3781 riscos mips-*-riscos* mips-*-sysv*
3782 sonymips mips-sony-*
3783 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3785 * REMOVED configurations and files
3787 SGI Irix-4.x mips-sgi-irix4 or iris4
3788 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3789 Z8000 simulator z8k-zilog-none or z8ksim
3790 Matsushita MN10200 w/simulator mn10200-*-*
3791 H8/500 simulator h8500-hitachi-hms or h8500hms
3792 HP/PA running BSD hppa*-*-bsd*
3793 HP/PA running OSF/1 hppa*-*-osf*
3794 HP/PA Pro target hppa*-*-pro*
3795 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3796 386BSD i[3456]86-*-bsd*
3797 Sequent family i[3456]86-sequent-sysv4*
3798 i[3456]86-sequent-sysv*
3799 i[3456]86-sequent-bsd*
3800 SPARC running LynxOS sparc-*-lynxos*
3801 SPARC running SunOS 4 sparc-*-sunos4*
3802 Tsqware Sparclet sparclet-*-*
3803 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3805 *** Changes in GDB 6.0:
3809 Support for debugging the Objective-C programming language has been
3810 integrated into GDB.
3812 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3814 DWARF 2's Call Frame Information makes available compiler generated
3815 information that more exactly describes the program's run-time stack.
3816 By using this information, GDB is able to provide more robust stack
3819 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3820 have been updated to use a new backtrace mechanism which includes
3821 DWARF 2 CFI support.
3825 GDB's remote protocol has been extended to include support for hosted
3826 file I/O (where the remote target uses GDB's file system). See GDB's
3827 remote protocol documentation for details.
3829 * All targets using the new architecture framework.
3831 All of GDB's targets have been updated to use the new internal
3832 architecture framework. The way is now open for future GDB releases
3833 to include cross-architecture native debugging support (i386 on amd64,
3836 * GNU/Linux's Thread Local Storage (TLS)
3838 GDB now includes support for for the GNU/Linux implementation of
3839 per-thread variables.
3841 * GNU/Linux's Native POSIX Thread Library (NPTL)
3843 GDB's thread code has been updated to work with either the new
3844 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3846 * Separate debug info.
3848 GDB, in conjunction with BINUTILS, now supports a mechanism for
3849 automatically loading debug information from a separate file. Instead
3850 of shipping full debug and non-debug versions of system libraries,
3851 system integrators can now instead ship just the stripped libraries
3852 and optional debug files.
3854 * DWARF 2 Location Expressions
3856 DWARF 2 Location Expressions allow the compiler to more completely
3857 describe the location of variables (even in optimized code) to the
3860 GDB now includes preliminary support for location expressions (support
3861 for DW_OP_piece is still missing).
3865 A number of long standing bugs that caused GDB to die while starting a
3866 Java application have been fixed. GDB's Java support is now
3867 considered "useable".
3869 * GNU/Linux support for fork, vfork, and exec.
3871 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3872 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3875 * GDB supports logging output to a file
3877 There are two new commands, "set logging" and "show logging", which can be
3878 used to capture GDB's output to a file.
3880 * The meaning of "detach" has changed for gdbserver
3882 The "detach" command will now resume the application, as documented. To
3883 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3886 * d10v, m68hc11 `regs' command deprecated
3888 The `info registers' command has been updated so that it displays the
3889 registers using a format identical to the old `regs' command.
3893 A new command, "maint set profile on/off", has been added. This command can
3894 be used to enable or disable profiling while running GDB, to profile a
3895 session or a set of commands. In addition there is a new configure switch,
3896 "--enable-profiling", which will cause GDB to be compiled with profiling
3897 data, for more informative profiling results.
3899 * Default MI syntax changed to "mi2".
3901 The default MI (machine interface) syntax, enabled by the command line
3902 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3903 "mi1", can be enabled by specifying the option "-i=mi1".
3905 Support for the original "mi0" syntax (included in GDB 5.0) has been
3908 Fix for gdb/192: removed extraneous space when displaying frame level.
3909 Fix for gdb/672: update changelist is now output in mi list format.
3910 Fix for gdb/702: a -var-assign that updates the value now shows up
3911 in a subsequent -var-update.
3913 * New native configurations.
3915 FreeBSD/amd64 x86_64-*-freebsd*
3917 * Multi-arched targets.
3919 HP/PA HPUX11 hppa*-*-hpux*
3920 Renesas M32R/D w/simulator m32r-*-elf*
3922 * OBSOLETE configurations and files
3924 Configurations that have been declared obsolete in this release have
3925 been commented out. Unless there is activity to revive these
3926 configurations, the next release of GDB will have their sources
3927 permanently REMOVED.
3929 Z8000 simulator z8k-zilog-none or z8ksim
3930 Matsushita MN10200 w/simulator mn10200-*-*
3931 H8/500 simulator h8500-hitachi-hms or h8500hms
3932 HP/PA running BSD hppa*-*-bsd*
3933 HP/PA running OSF/1 hppa*-*-osf*
3934 HP/PA Pro target hppa*-*-pro*
3935 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3936 Sequent family i[3456]86-sequent-sysv4*
3937 i[3456]86-sequent-sysv*
3938 i[3456]86-sequent-bsd*
3939 Tsqware Sparclet sparclet-*-*
3940 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3942 * REMOVED configurations and files
3945 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3946 IBM AIX PS/2 i[3456]86-*-aix
3947 i386 running Mach 3.0 i[3456]86-*-mach3*
3948 i386 running Mach i[3456]86-*-mach*
3949 i386 running OSF/1 i[3456]86-*osf1mk*
3950 HP/Apollo 68k Family m68*-apollo*-sysv*,
3952 m68*-hp-bsd*, m68*-hp-hpux*
3953 Argonaut Risc Chip (ARC) arc-*-*
3954 Mitsubishi D30V d30v-*-*
3955 Fujitsu FR30 fr30-*-elf*
3956 OS/9000 i[34]86-*-os9k
3957 I960 with MON960 i960-*-coff
3959 * MIPS $fp behavior changed
3961 The convenience variable $fp, for the MIPS, now consistently returns
3962 the address of the current frame's base. Previously, depending on the
3963 context, $fp could refer to either $sp or the current frame's base
3964 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3965 The GNU Source-Level Debugger''.
3967 *** Changes in GDB 5.3:
3969 * GNU/Linux shared library multi-threaded performance improved.
3971 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3972 `/proc', in preference to `ptrace' for memory reads. This may result
3973 in an improvement in the start-up time of multi-threaded, shared
3974 library applications when run under GDB. One GDB user writes: ``loads
3975 shared libs like mad''.
3977 * ``gdbserver'' now supports multi-threaded applications on some targets
3979 Support for debugging multi-threaded applications which use
3980 the GNU/Linux LinuxThreads package has been added for
3981 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3982 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3984 * GDB now supports C/C++ preprocessor macros.
3986 GDB now expands preprocessor macro invocations in C/C++ expressions,
3987 and provides various commands for showing macro definitions and how
3990 The new command `macro expand EXPRESSION' expands any macro
3991 invocations in expression, and shows the result.
3993 The new command `show macro MACRO-NAME' shows the definition of the
3994 macro named MACRO-NAME, and where it was defined.
3996 Most compilers don't include information about macros in the debugging
3997 information by default. In GCC 3.1, for example, you need to compile
3998 your program with the options `-gdwarf-2 -g3'. If the macro
3999 information is present in the executable, GDB will read it.
4001 * Multi-arched targets.
4003 DEC Alpha (partial) alpha*-*-*
4004 DEC VAX (partial) vax-*-*
4006 National Semiconductor NS32000 (partial) ns32k-*-*
4007 Motorola 68000 (partial) m68k-*-*
4008 Motorola MCORE mcore-*-*
4012 Fujitsu FRV architecture added by Red Hat frv*-*-*
4015 * New native configurations
4017 Alpha NetBSD alpha*-*-netbsd*
4018 SH NetBSD sh*-*-netbsdelf*
4019 MIPS NetBSD mips*-*-netbsd*
4020 UltraSPARC NetBSD sparc64-*-netbsd*
4022 * OBSOLETE configurations and files
4024 Configurations that have been declared obsolete in this release have
4025 been commented out. Unless there is activity to revive these
4026 configurations, the next release of GDB will have their sources
4027 permanently REMOVED.
4029 Mitsubishi D30V d30v-*-*
4030 OS/9000 i[34]86-*-os9k
4031 IBM AIX PS/2 i[3456]86-*-aix
4032 Fujitsu FR30 fr30-*-elf*
4033 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4034 Argonaut Risc Chip (ARC) arc-*-*
4035 i386 running Mach 3.0 i[3456]86-*-mach3*
4036 i386 running Mach i[3456]86-*-mach*
4037 i386 running OSF/1 i[3456]86-*osf1mk*
4038 HP/Apollo 68k Family m68*-apollo*-sysv*,
4040 m68*-hp-bsd*, m68*-hp-hpux*
4041 I960 with MON960 i960-*-coff
4043 * OBSOLETE languages
4045 CHILL, a Pascal like language used by telecommunications companies.
4047 * REMOVED configurations and files
4049 AMD 29k family via UDI a29k-amd-udi, udi29k
4050 A29K VxWorks a29k-*-vxworks
4051 AMD 29000 embedded, using EBMON a29k-none-none
4052 AMD 29000 embedded with COFF a29k-none-coff
4053 AMD 29000 embedded with a.out a29k-none-aout
4055 testsuite/gdb.hp/gdb.threads-hp/ directory
4057 * New command "set max-user-call-depth <nnn>"
4059 This command allows the user to limit the call depth of user-defined
4060 commands. The default is 1024.
4062 * Changes in FreeBSD/i386 native debugging.
4064 Support for the "generate-core-file" has been added.
4066 * New commands "dump", "append", and "restore".
4068 These commands allow data to be copied from target memory
4069 to a bfd-format or binary file (dump and append), and back
4070 from a file into memory (restore).
4072 * Improved "next/step" support on multi-processor Alpha Tru64.
4074 The previous single-step mechanism could cause unpredictable problems,
4075 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4076 of a software single-step mechanism prevents this.
4078 *** Changes in GDB 5.2.1:
4086 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4087 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4088 Fix, by Joel Brobecker imported from mainline.
4090 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4091 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4092 Fix, by Fred Fish, imported from mainline.
4094 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4095 Surprisingly enough, it works now.
4096 By Michal Ludvig, imported from mainline.
4098 i386 hardware watchpoint support:
4099 avoid misses on second run for some targets.
4100 By Pierre Muller, imported from mainline.
4102 *** Changes in GDB 5.2:
4104 * New command "set trust-readonly-sections on[off]".
4106 This command is a hint that tells gdb that read-only sections
4107 really are read-only (ie. that their contents will not change).
4108 In this mode, gdb will go to the object file rather than the
4109 target to read memory from read-only sections (such as ".text").
4110 This can be a significant performance improvement on some
4111 (notably embedded) targets.
4113 * New command "generate-core-file" (or "gcore").
4115 This new gdb command allows the user to drop a core file of the child
4116 process state at any time. So far it's been implemented only for
4117 GNU/Linux and Solaris, but should be relatively easily ported to other
4118 hosts. Argument is core file name (defaults to core.<pid>).
4120 * New command line option
4122 GDB now accepts --pid or -p followed by a process id.
4124 * Change in command line behavior -- corefiles vs. process ids.
4126 There is a subtle behavior in the way in which GDB handles
4127 command line arguments. The first non-flag argument is always
4128 a program to debug, but the second non-flag argument may either
4129 be a corefile or a process id. Previously, GDB would attempt to
4130 open the second argument as a corefile, and if that failed, would
4131 issue a superfluous error message and then attempt to attach it as
4132 a process. Now, if the second argument begins with a non-digit,
4133 it will be treated as a corefile. If it begins with a digit,
4134 GDB will attempt to attach it as a process, and if no such process
4135 is found, will then attempt to open it as a corefile.
4137 * Changes in ARM configurations.
4139 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4140 configuration is fully multi-arch.
4142 * New native configurations
4144 ARM NetBSD arm*-*-netbsd*
4145 x86 OpenBSD i[3456]86-*-openbsd*
4146 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4147 Sparc64 running FreeBSD sparc64-*-freebsd*
4151 Sanyo XStormy16 xstormy16-elf
4153 * OBSOLETE configurations and files
4155 Configurations that have been declared obsolete in this release have
4156 been commented out. Unless there is activity to revive these
4157 configurations, the next release of GDB will have their sources
4158 permanently REMOVED.
4160 AMD 29k family via UDI a29k-amd-udi, udi29k
4161 A29K VxWorks a29k-*-vxworks
4162 AMD 29000 embedded, using EBMON a29k-none-none
4163 AMD 29000 embedded with COFF a29k-none-coff
4164 AMD 29000 embedded with a.out a29k-none-aout
4166 testsuite/gdb.hp/gdb.threads-hp/ directory
4168 * REMOVED configurations and files
4170 TI TMS320C80 tic80-*-*
4172 PowerPC Solaris powerpcle-*-solaris*
4173 PowerPC Windows NT powerpcle-*-cygwin32
4174 PowerPC Netware powerpc-*-netware*
4175 Harris/CXUX m88k m88*-harris-cxux*
4176 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4177 ns32k-utek-sysv* ns32k-utek-*
4178 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4179 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4180 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4181 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4182 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4184 * Changes to command line processing
4186 The new `--args' feature can be used to specify command-line arguments
4187 for the inferior from gdb's command line.
4189 * Changes to key bindings
4191 There is a new `operate-and-get-next' function bound to `C-o'.
4193 *** Changes in GDB 5.1.1
4195 Fix compile problem on DJGPP.
4197 Fix a problem with floating-point registers on the i386 being
4200 Fix to stop GDB crashing on .debug_str debug info.
4202 Numerous documentation fixes.
4204 Numerous testsuite fixes.
4206 *** Changes in GDB 5.1:
4208 * New native configurations
4210 Alpha FreeBSD alpha*-*-freebsd*
4211 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4212 MIPS GNU/Linux mips*-*-linux*
4213 MIPS SGI Irix 6.x mips*-sgi-irix6*
4214 ia64 AIX ia64-*-aix*
4215 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4219 Motorola 68HC11 and 68HC12 m68hc11-elf
4221 UltraSparc running GNU/Linux sparc64-*-linux*
4223 * OBSOLETE configurations and files
4225 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4226 Harris/CXUX m88k m88*-harris-cxux*
4227 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4228 ns32k-utek-sysv* ns32k-utek-*
4229 TI TMS320C80 tic80-*-*
4231 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4232 PowerPC Solaris powerpcle-*-solaris*
4233 PowerPC Windows NT powerpcle-*-cygwin32
4234 PowerPC Netware powerpc-*-netware*
4235 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4236 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4237 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4238 Apple Macintosh (MPW) host N/A
4240 stuff.c (Program to stuff files into a specially prepared space in kdb)
4241 kdb-start.c (Main loop for the standalone kernel debugger)
4243 Configurations that have been declared obsolete in this release have
4244 been commented out. Unless there is activity to revive these
4245 configurations, the next release of GDB will have their sources
4246 permanently REMOVED.
4248 * REMOVED configurations and files
4250 Altos 3068 m68*-altos-*
4251 Convex c1-*-*, c2-*-*
4253 ARM RISCix arm-*-* (as host)
4257 * GDB has been converted to ISO C.
4259 GDB's source code has been converted to ISO C. In particular, the
4260 sources are fully protoized, and rely on standard headers being
4265 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4267 * The MI enabled by default.
4269 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4270 revised and enabled by default. Packages which use GDB as a debugging
4271 engine behind a UI or another front end are encouraged to switch to
4272 using the GDB/MI interface, instead of the old annotations interface
4273 which is now deprecated.
4275 * Support for debugging Pascal programs.
4277 GDB now includes support for debugging Pascal programs. The following
4278 main features are supported:
4280 - Pascal-specific data types such as sets;
4282 - automatic recognition of Pascal sources based on file-name
4285 - Pascal-style display of data types, variables, and functions;
4287 - a Pascal expression parser.
4289 However, some important features are not yet supported.
4291 - Pascal string operations are not supported at all;
4293 - there are some problems with boolean types;
4295 - Pascal type hexadecimal constants are not supported
4296 because they conflict with the internal variables format;
4298 - support for Pascal objects and classes is not full yet;
4300 - unlike Pascal, GDB is case-sensitive for symbol names.
4302 * Changes in completion.
4304 Commands such as `shell', `run' and `set args', which pass arguments
4305 to inferior programs, now complete on file names, similar to what
4306 users expect at the shell prompt.
4308 Commands which accept locations, such as `disassemble', `print',
4309 `breakpoint', `until', etc. now complete on filenames as well as
4310 program symbols. Thus, if you type "break foob TAB", and the source
4311 files linked into the programs include `foobar.c', that file name will
4312 be one of the candidates for completion. However, file names are not
4313 considered for completion after you typed a colon that delimits a file
4314 name from a name of a function in that file, as in "break foo.c:bar".
4316 `set demangle-style' completes on available demangling styles.
4318 * New platform-independent commands:
4320 It is now possible to define a post-hook for a command as well as a
4321 hook that runs before the command. For more details, see the
4322 documentation of `hookpost' in the GDB manual.
4324 * Changes in GNU/Linux native debugging.
4326 Support for debugging multi-threaded programs has been completely
4327 revised for all platforms except m68k and sparc. You can now debug as
4328 many threads as your system allows you to have.
4330 Attach/detach is supported for multi-threaded programs.
4332 Support for SSE registers was added for x86. This doesn't work for
4333 multi-threaded programs though.
4335 * Changes in MIPS configurations.
4337 Multi-arch support is enabled for all MIPS configurations.
4339 GDB can now be built as native debugger on SGI Irix 6.x systems for
4340 debugging n32 executables. (Debugging 64-bit executables is not yet
4343 * Unified support for hardware watchpoints in all x86 configurations.
4345 Most (if not all) native x86 configurations support hardware-assisted
4346 breakpoints and watchpoints in a unified manner. This support
4347 implements debug register sharing between watchpoints, which allows to
4348 put a virtually infinite number of watchpoints on the same address,
4349 and also supports watching regions up to 16 bytes with several debug
4352 The new maintenance command `maintenance show-debug-regs' toggles
4353 debugging print-outs in functions that insert, remove, and test
4354 watchpoints and hardware breakpoints.
4356 * Changes in the DJGPP native configuration.
4358 New command ``info dos sysinfo'' displays assorted information about
4359 the CPU, OS, memory, and DPMI server.
4361 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4362 display information about segment descriptors stored in GDT, LDT, and
4365 New commands ``info dos pde'' and ``info dos pte'' display entries
4366 from Page Directory and Page Tables (for now works with CWSDPMI only).
4367 New command ``info dos address-pte'' displays the Page Table entry for
4368 a given linear address.
4370 GDB can now pass command lines longer than 126 characters to the
4371 program being debugged (requires an update to the libdbg.a library
4372 which is part of the DJGPP development kit).
4374 DWARF2 debug info is now supported.
4376 It is now possible to `step' and `next' through calls to `longjmp'.
4378 * Changes in documentation.
4380 All GDB documentation was converted to GFDL, the GNU Free
4381 Documentation License.
4383 Tracepoints-related commands are now fully documented in the GDB
4386 TUI, the Text-mode User Interface, is now documented in the manual.
4388 Tracepoints-related commands are now fully documented in the GDB
4391 The "GDB Internals" manual now has an index. It also includes
4392 documentation of `ui_out' functions, GDB coding standards, x86
4393 hardware watchpoints, and memory region attributes.
4395 * GDB's version number moved to ``version.in''
4397 The Makefile variable VERSION has been replaced by the file
4398 ``version.in''. People creating GDB distributions should update the
4399 contents of this file.
4403 GUD support is now a standard part of the EMACS distribution.
4405 *** Changes in GDB 5.0:
4407 * Improved support for debugging FP programs on x86 targets
4409 Unified and much-improved support for debugging floating-point
4410 programs on all x86 targets. In particular, ``info float'' now
4411 displays the FP registers in the same format on all x86 targets, with
4412 greater level of detail.
4414 * Improvements and bugfixes in hardware-assisted watchpoints
4416 It is now possible to watch array elements, struct members, and
4417 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4418 on x86 targets no longer erroneously trigger when the address is
4421 * Improvements in the native DJGPP version of GDB
4423 The distribution now includes all the scripts and auxiliary files
4424 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4425 machines ``out of the box''.
4427 The DJGPP version can now debug programs that use signals. It is
4428 possible to catch signals that happened in the debuggee, deliver
4429 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4430 would kill the program being debugged.) Programs that hook hardware
4431 interrupts (keyboard, timer, etc.) can also be debugged.
4433 It is now possible to debug DJGPP programs that redirect their
4434 standard handles or switch them to raw (as opposed to cooked) mode, or
4435 even close them. The command ``run < foo > bar'' works as expected,
4436 and ``info terminal'' reports useful information about the debuggee's
4437 terminal, including raw/cooked mode, redirection, etc.
4439 The DJGPP version now uses termios functions for console I/O, which
4440 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4443 DOS-style file names with drive letters are now fully supported by
4446 It is now possible to debug DJGPP programs that switch their working
4447 directory. It is also possible to rerun the debuggee any number of
4448 times without restarting GDB; thus, you can use the same setup,
4449 breakpoints, etc. for many debugging sessions.
4451 * New native configurations
4453 ARM GNU/Linux arm*-*-linux*
4454 PowerPC GNU/Linux powerpc-*-linux*
4458 Motorola MCore mcore-*-*
4459 x86 VxWorks i[3456]86-*-vxworks*
4460 PowerPC VxWorks powerpc-*-vxworks*
4461 TI TMS320C80 tic80-*-*
4463 * OBSOLETE configurations
4465 Altos 3068 m68*-altos-*
4466 Convex c1-*-*, c2-*-*
4468 ARM RISCix arm-*-* (as host)
4471 Configurations that have been declared obsolete will be commented out,
4472 but the code will be left in place. If there is no activity to revive
4473 these configurations before the next release of GDB, the sources will
4474 be permanently REMOVED.
4476 * Gould support removed
4478 Support for the Gould PowerNode and NP1 has been removed.
4480 * New features for SVR4
4482 On SVR4 native platforms (such as Solaris), if you attach to a process
4483 without first loading a symbol file, GDB will now attempt to locate and
4484 load symbols from the running process's executable file.
4486 * Many C++ enhancements
4488 C++ support has been greatly improved. Overload resolution now works properly
4489 in almost all cases. RTTI support is on the way.
4491 * Remote targets can connect to a sub-program
4493 A popen(3) style serial-device has been added. This device starts a
4494 sub-process (such as a stand-alone simulator) and then communicates
4495 with that. The sub-program to run is specified using the syntax
4496 ``|<program> <args>'' vis:
4498 (gdb) set remotedebug 1
4499 (gdb) target extended-remote |mn10300-elf-sim program-args
4501 * MIPS 64 remote protocol
4503 A long standing bug in the mips64 remote protocol where by GDB
4504 expected certain 32 bit registers (ex SR) to be transfered as 32
4505 instead of 64 bits has been fixed.
4507 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4508 added to provide backward compatibility with older versions of GDB.
4510 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4512 The command ``set remotebinarydownload'' command has been replaced by
4513 ``set remote X-packet''. Other commands in ``set remote'' family
4514 include ``set remote P-packet''.
4516 * Breakpoint commands accept ranges.
4518 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4519 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4520 ``tracepoint passcount'' also accepts a range of tracepoints.
4522 * ``apropos'' command added.
4524 The ``apropos'' command searches through command names and
4525 documentation strings, printing out matches, making it much easier to
4526 try to find a command that does what you are looking for.
4530 A new machine oriented interface (MI) has been added to GDB. This
4531 interface is designed for debug environments running GDB as a separate
4532 process. This is part of the long term libGDB project. See the
4533 "GDB/MI" chapter of the GDB manual for further information. It can be
4534 enabled by configuring with:
4536 .../configure --enable-gdbmi
4538 *** Changes in GDB-4.18:
4540 * New native configurations
4542 HP-UX 10.20 hppa*-*-hpux10.20
4543 HP-UX 11.x hppa*-*-hpux11.0*
4544 M68K GNU/Linux m68*-*-linux*
4548 Fujitsu FR30 fr30-*-elf*
4549 Intel StrongARM strongarm-*-*
4550 Mitsubishi D30V d30v-*-*
4552 * OBSOLETE configurations
4554 Gould PowerNode, NP1 np1-*-*, pn-*-*
4556 Configurations that have been declared obsolete will be commented out,
4557 but the code will be left in place. If there is no activity to revive
4558 these configurations before the next release of GDB, the sources will
4559 be permanently REMOVED.
4563 As a compatibility experiment, GDB's source files buildsym.h and
4564 buildsym.c have been converted to pure standard C, no longer
4565 containing any K&R compatibility code. We believe that all systems in
4566 use today either come with a standard C compiler, or have a GCC port
4567 available. If this is not true, please report the affected
4568 configuration to bug-gdb@gnu.org immediately. See the README file for
4569 information about getting a standard C compiler if you don't have one
4574 GDB now uses readline 2.2.
4576 * set extension-language
4578 You can now control the mapping between filename extensions and source
4579 languages by using the `set extension-language' command. For instance,
4580 you can ask GDB to treat .c files as C++ by saying
4581 set extension-language .c c++
4582 The command `info extensions' lists all of the recognized extensions
4583 and their associated languages.
4585 * Setting processor type for PowerPC and RS/6000
4587 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4588 you can use the `set processor' command to specify what variant of the
4589 PowerPC family you are debugging. The command
4593 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4594 following PowerPC and RS6000 variants:
4596 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4597 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4599 403GC IBM PowerPC 403GC
4600 505 Motorola PowerPC 505
4601 860 Motorola PowerPC 860 or 850
4602 601 Motorola PowerPC 601
4603 602 Motorola PowerPC 602
4604 603 Motorola/IBM PowerPC 603 or 603e
4605 604 Motorola PowerPC 604 or 604e
4606 750 Motorola/IBM PowerPC 750 or 750
4608 At the moment, this command just tells GDB what to name the
4609 special-purpose processor registers. Since almost all the affected
4610 registers are inaccessible to user-level programs, this command is
4611 only useful for remote debugging in its present form.
4615 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4616 more extensive support for HP-UX. Added features include shared
4617 library support, kernel threads and hardware watchpoints for 11.00,
4618 support for HP's ANSI C and C++ compilers, and a compatibility mode
4619 for xdb and dbx commands.
4623 HP's donation includes the new concept of catchpoints, which is a
4624 generalization of the old catch command. On HP-UX, it is now possible
4625 to catch exec, fork, and vfork, as well as library loading.
4627 This means that the existing catch command has changed; its first
4628 argument now specifies the type of catch to be set up. See the
4629 output of "help catch" for a list of catchpoint types.
4631 * Debugging across forks
4633 On HP-UX, you can choose which process to debug when a fork() happens
4638 HP has donated a curses-based terminal user interface (TUI). To get
4639 it, build with --enable-tui. Although this can be enabled for any
4640 configuration, at present it only works for native HP debugging.
4642 * GDB remote protocol additions
4644 A new protocol packet 'X' that writes binary data is now available.
4645 Default behavior is to try 'X', then drop back to 'M' if the stub
4646 fails to respond. The settable variable `remotebinarydownload'
4647 allows explicit control over the use of 'X'.
4649 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4650 full 64-bit address. The command
4652 set remoteaddresssize 32
4654 can be used to revert to the old behaviour. For existing remote stubs
4655 the change should not be noticed, as the additional address information
4658 In order to assist in debugging stubs, you may use the maintenance
4659 command `packet' to send any text string to the stub. For instance,
4661 maint packet heythere
4663 sends the packet "$heythere#<checksum>". Note that it is very easy to
4664 disrupt a debugging session by sending the wrong packet at the wrong
4667 The compare-sections command allows you to compare section data on the
4668 target to what is in the executable file without uploading or
4669 downloading, by comparing CRC checksums.
4671 * Tracing can collect general expressions
4673 You may now collect general expressions at tracepoints. This requires
4674 further additions to the target-side stub; see tracepoint.c and
4675 doc/agentexpr.texi for further details.
4677 * mask-address variable for Mips
4679 For Mips targets, you may control the zeroing of the upper 32 bits of
4680 a 64-bit address by entering `set mask-address on'. This is mainly
4681 of interest to users of embedded R4xxx and R5xxx processors.
4683 * Higher serial baud rates
4685 GDB's serial code now allows you to specify baud rates 57600, 115200,
4686 230400, and 460800 baud. (Note that your host system may not be able
4687 to achieve all of these rates.)
4691 The i960 configuration now includes an initial implementation of a
4692 builtin simulator, contributed by Jim Wilson.
4695 *** Changes in GDB-4.17:
4697 * New native configurations
4699 Alpha GNU/Linux alpha*-*-linux*
4700 Unixware 2.x i[3456]86-unixware2*
4701 Irix 6.x mips*-sgi-irix6*
4702 PowerPC GNU/Linux powerpc-*-linux*
4703 PowerPC Solaris powerpcle-*-solaris*
4704 Sparc GNU/Linux sparc-*-linux*
4705 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4709 Argonaut Risc Chip (ARC) arc-*-*
4710 Hitachi H8/300S h8300*-*-*
4711 Matsushita MN10200 w/simulator mn10200-*-*
4712 Matsushita MN10300 w/simulator mn10300-*-*
4713 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4714 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4715 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4716 Mitsubishi D10V w/simulator d10v-*-*
4717 Mitsubishi M32R/D w/simulator m32r-*-elf*
4718 Tsqware Sparclet sparclet-*-*
4719 NEC V850 w/simulator v850-*-*
4721 * New debugging protocols
4723 ARM with RDI protocol arm*-*-*
4724 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4725 DDB and LSI variants of PMON protocol mips*-*-*
4726 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4727 PowerPC with SDS protocol powerpc{,le}-*-eabi
4728 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4732 All configurations can now understand and use the DWARF 2 debugging
4733 format. The choice is automatic, if the symbol file contains DWARF 2
4738 GDB now includes basic Java language support. This support is
4739 only useful with Java compilers that produce native machine code.
4741 * solib-absolute-prefix and solib-search-path
4743 For SunOS and SVR4 shared libraries, you may now set the prefix for
4744 loading absolute shared library symbol files, and the search path for
4745 locating non-absolute shared library symbol files.
4747 * Live range splitting
4749 GDB can now effectively debug code for which GCC has performed live
4750 range splitting as part of its optimization. See gdb/doc/LRS for
4751 more details on the expected format of the stabs information.
4755 GDB's support for the GNU Hurd, including thread debugging, has been
4756 updated to work with current versions of the Hurd.
4760 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4761 instruction set. ARM GDB automatically detects when Thumb
4762 instructions are in use, and adjusts disassembly and backtracing
4767 GDB's MIPS target configurations now handle the MIP16 16-bit
4772 GDB now includes support for overlays; if an executable has been
4773 linked such that multiple sections are based at the same address, GDB
4774 will decide which section to use for symbolic info. You can choose to
4775 control the decision manually, using overlay commands, or implement
4776 additional target-side support and use "overlay load-target" to bring
4777 in the overlay mapping. Do "help overlay" for more detail.
4781 The command "info symbol <address>" displays information about
4782 the symbol at the specified address.
4786 The standard remote protocol now includes an extension that allows
4787 asynchronous collection and display of trace data. This requires
4788 extensive support in the target-side debugging stub. Tracing mode
4789 includes a new interaction mode in GDB and new commands: see the
4790 file tracepoint.c for more details.
4794 Configurations for embedded MIPS now include a simulator contributed
4795 by Cygnus Solutions. The simulator supports the instruction sets
4796 of most MIPS variants.
4800 Sparc configurations may now include the ERC32 simulator contributed
4801 by the European Space Agency. The simulator is not built into
4802 Sparc targets by default; configure with --enable-sim to include it.
4806 For target configurations that may include multiple variants of a
4807 basic architecture (such as MIPS and SH), you may now set the
4808 architecture explicitly. "set arch" sets, "info arch" lists
4809 the possible architectures.
4811 *** Changes in GDB-4.16:
4813 * New native configurations
4815 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4816 M68K NetBSD m68k-*-netbsd*
4817 PowerPC AIX 4.x powerpc-*-aix*
4818 PowerPC MacOS powerpc-*-macos*
4819 PowerPC Windows NT powerpcle-*-cygwin32
4820 RS/6000 AIX 4.x rs6000-*-aix4*
4824 ARM with RDP protocol arm-*-*
4825 I960 with MON960 i960-*-coff
4826 MIPS VxWorks mips*-*-vxworks*
4827 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4828 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4830 Matra Sparclet sparclet-*-*
4834 The powerpc-eabi configuration now includes the PSIM simulator,
4835 contributed by Andrew Cagney, with assistance from Mike Meissner.
4836 PSIM is a very elaborate model of the PowerPC, including not only
4837 basic instruction set execution, but also details of execution unit
4838 performance and I/O hardware. See sim/ppc/README for more details.
4842 GDB now works with Solaris 2.5.
4844 * Windows 95/NT native
4846 GDB will now work as a native debugger on Windows 95 and Windows NT.
4847 To build it from source, you must use the "gnu-win32" environment,
4848 which uses a DLL to emulate enough of Unix to run the GNU tools.
4849 Further information, binaries, and sources are available at
4850 ftp.cygnus.com, under pub/gnu-win32.
4852 * dont-repeat command
4854 If a user-defined command includes the command `dont-repeat', then the
4855 command will not be repeated if the user just types return. This is
4856 useful if the command is time-consuming to run, so that accidental
4857 extra keystrokes don't run the same command many times.
4859 * Send break instead of ^C
4861 The standard remote protocol now includes an option to send a break
4862 rather than a ^C to the target in order to interrupt it. By default,
4863 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4865 * Remote protocol timeout
4867 The standard remote protocol includes a new variable `remotetimeout'
4868 that allows you to set the number of seconds before GDB gives up trying
4869 to read from the target. The default value is 2.
4871 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4873 By default GDB will automatically keep track of objects as they are
4874 loaded and unloaded by the dynamic linker. By using the command `set
4875 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4876 when shared library events occur, thus allowing you to set breakpoints
4877 in shared libraries which are explicitly loaded by the inferior.
4879 Note this feature does not work on hpux8. On hpux9 you must link
4880 /usr/lib/end.o into your program. This feature should work
4881 automatically on hpux10.
4883 * Irix 5.x hardware watchpoint support
4885 Irix 5 configurations now support the use of hardware watchpoints.
4887 * Mips protocol "SYN garbage limit"
4889 When debugging a Mips target using the `target mips' protocol, you
4890 may set the number of characters that GDB will ignore by setting
4891 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4892 every character. The default value is 1050.
4894 * Recording and replaying remote debug sessions
4896 If you set `remotelogfile' to the name of a file, gdb will write to it
4897 a recording of a remote debug session. This recording may then be
4898 replayed back to gdb using "gdbreplay". See gdbserver/README for
4899 details. This is useful when you have a problem with GDB while doing
4900 remote debugging; you can make a recording of the session and send it
4901 to someone else, who can then recreate the problem.
4903 * Speedups for remote debugging
4905 GDB includes speedups for downloading and stepping MIPS systems using
4906 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4907 and more efficient S-record downloading.
4909 * Memory use reductions and statistics collection
4911 GDB now uses less memory and reports statistics about memory usage.
4912 Try the `maint print statistics' command, for example.
4914 *** Changes in GDB-4.15:
4916 * Psymtabs for XCOFF
4918 The symbol reader for AIX GDB now uses partial symbol tables. This
4919 can greatly improve startup time, especially for large executables.
4921 * Remote targets use caching
4923 Remote targets now use a data cache to speed up communication with the
4924 remote side. The data cache could lead to incorrect results because
4925 it doesn't know about volatile variables, thus making it impossible to
4926 debug targets which use memory mapped I/O devices. `set remotecache
4927 off' turns the the data cache off.
4929 * Remote targets may have threads
4931 The standard remote protocol now includes support for multiple threads
4932 in the target system, using new protocol commands 'H' and 'T'. See
4933 gdb/remote.c for details.
4937 If GDB is configured with `--enable-netrom', then it will include
4938 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4939 acts as though it is a bank of ROM on the target board, but you can
4940 write into it over the network. GDB's support consists only of
4941 support for fast loading into the emulated ROM; to debug, you must use
4942 another protocol, such as standard remote protocol. The usual
4943 sequence is something like
4945 target nrom <netrom-hostname>
4947 target remote <netrom-hostname>:1235
4951 GDB now includes support for the Apple Macintosh, as a host only. It
4952 may be run as either an MPW tool or as a standalone application, and
4953 it can debug through the serial port. All the usual GDB commands are
4954 available, but to the target command, you must supply "serial" as the
4955 device type instead of "/dev/ttyXX". See mpw-README in the main
4956 directory for more information on how to build. The MPW configuration
4957 scripts */mpw-config.in support only a few targets, and only the
4958 mips-idt-ecoff target has been tested.
4962 GDB configuration now uses autoconf. This is not user-visible,
4963 but does simplify configuration and building.
4967 GDB now supports hpux10.
4969 *** Changes in GDB-4.14:
4971 * New native configurations
4973 x86 FreeBSD i[345]86-*-freebsd
4974 x86 NetBSD i[345]86-*-netbsd
4975 NS32k NetBSD ns32k-*-netbsd
4976 Sparc NetBSD sparc-*-netbsd
4980 A29K VxWorks a29k-*-vxworks
4981 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4982 CPU32 EST-300 emulator m68*-*-est*
4983 PowerPC ELF powerpc-*-elf
4986 * Alpha OSF/1 support for procfs
4988 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4989 possible to attach to running processes. As the mounting of the /proc
4990 filesystem is optional on the Alpha, GDB automatically determines
4991 the availability of /proc during startup. This can lead to problems
4992 if /proc is unmounted after GDB has been started.
4994 * Arguments to user-defined commands
4996 User commands may accept up to 10 arguments separated by whitespace.
4997 Arguments are accessed within the user command via $arg0..$arg9. A
5000 print $arg0 + $arg1 + $arg2
5002 To execute the command use:
5005 Defines the command "adder" which prints the sum of its three arguments.
5006 Note the arguments are text substitutions, so they may reference variables,
5007 use complex expressions, or even perform inferior function calls.
5009 * New `if' and `while' commands
5011 This makes it possible to write more sophisticated user-defined
5012 commands. Both commands take a single argument, which is the
5013 expression to evaluate, and must be followed by the commands to
5014 execute, one per line, if the expression is nonzero, the list being
5015 terminated by the word `end'. The `if' command list may include an
5016 `else' word, which causes the following commands to be executed only
5017 if the expression is zero.
5019 * Fortran source language mode
5021 GDB now includes partial support for Fortran 77. It will recognize
5022 Fortran programs and can evaluate a subset of Fortran expressions, but
5023 variables and functions may not be handled correctly. GDB will work
5024 with G77, but does not yet know much about symbols emitted by other
5027 * Better HPUX support
5029 Most debugging facilities now work on dynamic executables for HPPAs
5030 running hpux9 or later. You can attach to running dynamically linked
5031 processes, but by default the dynamic libraries will be read-only, so
5032 for instance you won't be able to put breakpoints in them. To change
5033 that behavior do the following before running the program:
5039 This will cause the libraries to be mapped private and read-write.
5040 To revert to the normal behavior, do this:
5046 You cannot set breakpoints or examine data in the library until after
5047 the library is loaded if the function/data symbols do not have
5050 GDB can now also read debug symbols produced by the HP C compiler on
5051 HPPAs (sorry, no C++, Fortran or 68k support).
5053 * Target byte order now dynamically selectable
5055 You can choose which byte order to use with a target system, via the
5056 commands "set endian big" and "set endian little", and you can see the
5057 current setting by using "show endian". You can also give the command
5058 "set endian auto", in which case GDB will use the byte order
5059 associated with the executable. Currently, only embedded MIPS
5060 configurations support dynamic selection of target byte order.
5062 * New DOS host serial code
5064 This version uses DPMI interrupts to handle buffered I/O, so you
5065 no longer need to run asynctsr when debugging boards connected to
5068 *** Changes in GDB-4.13:
5070 * New "complete" command
5072 This lists all the possible completions for the rest of the line, if it
5073 were to be given as a command itself. This is intended for use by emacs.
5075 * Trailing space optional in prompt
5077 "set prompt" no longer adds a space for you after the prompt you set. This
5078 allows you to set a prompt which ends in a space or one that does not.
5080 * Breakpoint hit counts
5082 "info break" now displays a count of the number of times the breakpoint
5083 has been hit. This is especially useful in conjunction with "ignore"; you
5084 can ignore a large number of breakpoint hits, look at the breakpoint info
5085 to see how many times the breakpoint was hit, then run again, ignoring one
5086 less than that number, and this will get you quickly to the last hit of
5089 * Ability to stop printing at NULL character
5091 "set print null-stop" will cause GDB to stop printing the characters of
5092 an array when the first NULL is encountered. This is useful when large
5093 arrays actually contain only short strings.
5095 * Shared library breakpoints
5097 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5098 breakpoints in shared libraries before the executable is run.
5100 * Hardware watchpoints
5102 There is a new hardware breakpoint for the watch command for sparclite
5103 targets. See gdb/sparclite/hw_breakpoint.note.
5105 Hardware watchpoints are also now supported under GNU/Linux.
5109 Annotations have been added. These are for use with graphical interfaces,
5110 and are still experimental. Currently only gdba.el uses these.
5112 * Improved Irix 5 support
5114 GDB now works properly with Irix 5.2.
5116 * Improved HPPA support
5118 GDB now works properly with the latest GCC and GAS.
5120 * New native configurations
5122 Sequent PTX4 i[34]86-sequent-ptx4
5123 HPPA running OSF/1 hppa*-*-osf*
5124 Atari TT running SVR4 m68*-*-sysv4*
5125 RS/6000 LynxOS rs6000-*-lynxos*
5129 OS/9000 i[34]86-*-os9k
5130 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5133 * Hitachi SH7000 and E7000-PC ICE support
5135 There is now support for communicating with the Hitachi E7000-PC ICE.
5136 This is available automatically when GDB is configured for the SH.
5140 As usual, a variety of small fixes and improvements, both generic
5141 and configuration-specific. See the ChangeLog for more detail.
5143 *** Changes in GDB-4.12:
5145 * Irix 5 is now supported
5149 GDB-4.12 on the HPPA has a number of changes which make it unable
5150 to debug the output from the currently released versions of GCC and
5151 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5152 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5153 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5156 *** Changes in GDB-4.11:
5158 * User visible changes:
5162 The "set remotedebug" option is now consistent between the mips remote
5163 target, remote targets using the gdb-specific protocol, UDI (AMD's
5164 debug protocol for the 29k) and the 88k bug monitor. It is now an
5165 integer specifying a debug level (normally 0 or 1, but 2 means more
5166 debugging info for the mips target).
5168 * DEC Alpha native support
5170 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5171 debug info, but GDB works fairly well with the DEC compiler and should
5172 work with a future GCC release. See the README file for a few
5173 Alpha-specific notes.
5175 * Preliminary thread implementation
5177 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5179 * LynxOS native and target support for 386
5181 This release has been hosted on LynxOS 2.2, and also can be configured
5182 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5185 * Improvements in C++ mangling/demangling.
5187 This release has much better g++ debugging, specifically in name
5188 mangling/demangling, virtual function calls, print virtual table,
5189 call methods, ...etc.
5191 *** Changes in GDB-4.10:
5193 * User visible changes:
5195 Remote debugging using the GDB-specific (`target remote') protocol now
5196 supports the `load' command. This is only useful if you have some
5197 other way of getting the stub to the target system, and you can put it
5198 somewhere in memory where it won't get clobbered by the download.
5200 Filename completion now works.
5202 When run under emacs mode, the "info line" command now causes the
5203 arrow to point to the line specified. Also, "info line" prints
5204 addresses in symbolic form (as well as hex).
5206 All vxworks based targets now support a user settable option, called
5207 vxworks-timeout. This option represents the number of seconds gdb
5208 should wait for responses to rpc's. You might want to use this if
5209 your vxworks target is, perhaps, a slow software simulator or happens
5210 to be on the far side of a thin network line.
5214 This release contains support for using a DEC alpha as a GDB host for
5215 cross debugging. Native alpha debugging is not supported yet.
5218 *** Changes in GDB-4.9:
5222 This is the first GDB release which is accompanied by a matching testsuite.
5223 The testsuite requires installation of dejagnu, which should be available
5224 via ftp from most sites that carry GNU software.
5228 'Cfront' style demangling has had its name changed to 'ARM' style, to
5229 emphasize that it was written from the specifications in the C++ Annotated
5230 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5231 disclaimers, it still generated too much confusion with users attempting to
5232 use gdb with AT&T cfront.
5236 GDB now uses a standard remote interface to a simulator library.
5237 So far, the library contains simulators for the Zilog Z8001/2, the
5238 Hitachi H8/300, H8/500 and Super-H.
5240 * New targets supported
5242 H8/300 simulator h8300-hitachi-hms or h8300hms
5243 H8/500 simulator h8500-hitachi-hms or h8500hms
5244 SH simulator sh-hitachi-hms or sh
5245 Z8000 simulator z8k-zilog-none or z8ksim
5246 IDT MIPS board over serial line mips-idt-ecoff
5248 Cross-debugging to GO32 targets is supported. It requires a custom
5249 version of the i386-stub.c module which is integrated with the
5250 GO32 memory extender.
5252 * New remote protocols
5254 MIPS remote debugging protocol.
5256 * New source languages supported
5258 This version includes preliminary support for Chill, a Pascal like language
5259 used by telecommunications companies. Chill support is also being integrated
5260 into the GNU compiler, but we don't know when it will be publically available.
5263 *** Changes in GDB-4.8:
5265 * HP Precision Architecture supported
5267 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5268 version of this support was available as a set of patches from the
5269 University of Utah. GDB does not support debugging of programs
5270 compiled with the HP compiler, because HP will not document their file
5271 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5272 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5274 Many problems in the preliminary version have been fixed.
5276 * Faster and better demangling
5278 We have improved template demangling and fixed numerous bugs in the GNU style
5279 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5280 character types (wchar_t) are now supported. Demangling of each symbol is now
5281 only done once, and is cached when the symbol table for a file is read in.
5282 This results in a small increase in memory usage for C programs, a moderate
5283 increase in memory usage for C++ programs, and a fantastic speedup in
5286 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5287 from the specifications in the Annotated Reference Manual, which AT&T's
5288 compiler does not actually implement.
5290 * G++ multiple inheritance compiler problem
5292 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5293 inheritance lattices was reworked to properly discover ambiguities. We
5294 recently found an example which causes this new algorithm to fail in a
5295 very subtle way, producing bad debug information for those classes.
5296 The file 'gcc.patch' (in this directory) can be applied to gcc to
5297 circumvent the problem. A future GCC release will contain a complete
5300 The previous G++ debug info problem (mentioned below for the gdb-4.7
5301 release) is fixed in gcc version 2.3.2.
5303 * Improved configure script
5305 The `configure' script will now attempt to guess your system type if
5306 you don't supply a host system type. The old scheme of supplying a
5307 host system triplet is preferable over using this. All the magic is
5308 done in the new `config.guess' script. Examine it for details.
5310 We have also brought our configure script much more in line with the FSF's
5311 version. It now supports the --with-xxx options. In particular,
5312 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5313 The resulting GDB will not be able to read arbitrary object file formats --
5314 only the format ``expected'' to be used on the configured target system.
5315 We hope to make this the default in a future release.
5317 * Documentation improvements
5319 There's new internal documentation on how to modify GDB, and how to
5320 produce clean changes to the code. We implore people to read it
5321 before submitting changes.
5323 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5324 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5325 `info' files are also provided. To build `info' files from scratch,
5326 you will need the latest `makeinfo' release, which will be available in
5327 a future texinfo-X.Y release.
5329 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5330 We're not sure exactly which versions have this problem, but it has
5331 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5332 or better. If that isn't possible, there is a patch in
5333 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5334 around this problem.
5338 GDB now supports array constants that can be used in expressions typed in by
5339 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5340 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5343 The new directory `gdb/sparclite' contains a program that demonstrates
5344 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5346 * New native hosts supported
5348 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5349 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5351 * New targets supported
5353 AMD 29k family via UDI a29k-amd-udi or udi29k
5355 * New file formats supported
5357 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5358 HPUX core files, and SCO 3.2v2 core files.
5362 Attaching to processes now works again; thanks for the many bug reports.
5364 We have also stomped on a bunch of core dumps caused by
5365 printf_filtered("%s") problems.
5367 We eliminated a copyright problem on the rpc and ptrace header files
5368 for VxWorks, which was discovered at the last minute during the 4.7
5369 release. You should now be able to build a VxWorks GDB.
5371 You can now interrupt gdb while an attached process is running. This
5372 will cause the attached process to stop, and give control back to GDB.
5374 We fixed problems caused by using too many file descriptors
5375 for reading symbols from object files and libraries. This was
5376 especially a problem for programs that used many (~100) shared
5379 The `step' command now only enters a subroutine if there is line number
5380 information for the subroutine. Otherwise it acts like the `next'
5381 command. Previously, `step' would enter subroutines if there was
5382 any debugging information about the routine. This avoids problems
5383 when using `cc -g1' on MIPS machines.
5385 * Internal improvements
5387 GDB's internal interfaces have been improved to make it easier to support
5388 debugging of multiple languages in the future.
5390 GDB now uses a common structure for symbol information internally.
5391 Minimal symbols (derived from linkage symbols in object files), partial
5392 symbols (from a quick scan of debug information), and full symbols
5393 contain a common subset of information, making it easier to write
5394 shared code that handles any of them.
5396 * New command line options
5398 We now accept --silent as an alias for --quiet.
5402 The memory-mapped-malloc library is now licensed under the GNU Library
5403 General Public License.
5405 *** Changes in GDB-4.7:
5407 * Host/native/target split
5409 GDB has had some major internal surgery to untangle the support for
5410 hosts and remote targets. Now, when you configure GDB for a remote
5411 target, it will no longer load in all of the support for debugging
5412 local programs on the host. When fully completed and tested, this will
5413 ensure that arbitrary host/target combinations are possible.
5415 The primary conceptual shift is to separate the non-portable code in
5416 GDB into three categories. Host specific code is required any time GDB
5417 is compiled on that host, regardless of the target. Target specific
5418 code relates to the peculiarities of the target, but can be compiled on
5419 any host. Native specific code is everything else: it can only be
5420 built when the host and target are the same system. Child process
5421 handling and core file support are two common `native' examples.
5423 GDB's use of /proc for controlling Unix child processes is now cleaner.
5424 It has been split out into a single module under the `target_ops' vector,
5425 plus two native-dependent functions for each system that uses /proc.
5427 * New hosts supported
5429 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5430 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5431 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5433 * New targets supported
5435 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5436 68030 and CPU32 m68030-*-*, m68332-*-*
5438 * New native hosts supported
5440 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5441 (386bsd is not well tested yet)
5442 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5444 * New file formats supported
5446 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5447 supports reading of `a.out.adobe' object files, which are an a.out
5448 format extended with minimal information about multiple sections.
5452 `show copying' is the same as the old `info copying'.
5453 `show warranty' is the same as `info warrantee'.
5454 These were renamed for consistency. The old commands continue to work.
5456 `info handle' is a new alias for `info signals'.
5458 You can now define pre-command hooks, which attach arbitrary command
5459 scripts to any command. The commands in the hook will be executed
5460 prior to the user's command. You can also create a hook which will be
5461 executed whenever the program stops. See gdb.texinfo.
5465 We now deal with Cfront style name mangling, and can even extract type
5466 info from mangled symbols. GDB can automatically figure out which
5467 symbol mangling style your C++ compiler uses.
5469 Calling of methods and virtual functions has been improved as well.
5473 The crash that occured when debugging Sun Ansi-C compiled binaries is
5474 fixed. This was due to mishandling of the extra N_SO stabs output
5477 We also finally got Ultrix 4.2 running in house, and fixed core file
5478 support, with help from a dozen people on the net.
5480 John M. Farrell discovered that the reason that single-stepping was so
5481 slow on all of the Mips based platforms (primarily SGI and DEC) was
5482 that we were trying to demangle and lookup a symbol used for internal
5483 purposes on every instruction that was being stepped through. Changing
5484 the name of that symbol so that it couldn't be mistaken for a C++
5485 mangled symbol sped things up a great deal.
5487 Rich Pixley sped up symbol lookups in general by getting much smarter
5488 about when C++ symbol mangling is necessary. This should make symbol
5489 completion (TAB on the command line) much faster. It's not as fast as
5490 we'd like, but it's significantly faster than gdb-4.6.
5494 A new user controllable variable 'call_scratch_address' can
5495 specify the location of a scratch area to be used when GDB
5496 calls a function in the target. This is necessary because the
5497 usual method of putting the scratch area on the stack does not work
5498 in systems that have separate instruction and data spaces.
5500 We integrated changes to support the 29k UDI (Universal Debugger
5501 Interface), but discovered at the last minute that we didn't have all
5502 of the appropriate copyright paperwork. We are working with AMD to
5503 resolve this, and hope to have it available soon.
5507 We have sped up the remote serial line protocol, especially for targets
5508 with lots of registers. It now supports a new `expedited status' ('T')
5509 message which can be used in place of the existing 'S' status message.
5510 This allows the remote stub to send only the registers that GDB
5511 needs to make a quick decision about single-stepping or conditional
5512 breakpoints, eliminating the need to fetch the entire register set for
5513 each instruction being stepped through.
5515 The GDB remote serial protocol now implements a write-through cache for
5516 registers, only re-reading the registers if the target has run.
5518 There is also a new remote serial stub for SPARC processors. You can
5519 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5520 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5521 processor with a serial port.
5525 Configure.in files have become much easier to read and modify. A new
5526 `table driven' format makes it more obvious what configurations are
5527 supported, and what files each one uses.
5531 There is a new opcodes library which will eventually contain all of the
5532 disassembly routines and opcode tables. At present, it only contains
5533 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5534 disassembler (binutils/objdump) to share these routines.
5536 The libiberty library is now copylefted under the GNU Library General
5537 Public License. This allows more liberal use, and was done so libg++
5538 can use it. This makes no difference to GDB, since the Library License
5539 grants all the rights from the General Public License.
5543 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5544 reference to the stabs symbol info used by the debugger. It is (as far
5545 as we know) the only published document on this fascinating topic. We
5546 encourage you to read it, compare it to the stabs information on your
5547 system, and send improvements on the document in general (to
5548 bug-gdb@prep.ai.mit.edu).
5550 And, of course, many bugs have been fixed.
5553 *** Changes in GDB-4.6:
5555 * Better support for C++ function names
5557 GDB now accepts as input the "demangled form" of C++ overloaded function
5558 names and member function names, and can do command completion on such names
5559 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5560 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5561 Make use of command completion, it is your friend.
5563 GDB also now accepts a variety of C++ mangled symbol formats. They are
5564 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5565 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5566 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5567 for the list of formats.
5569 * G++ symbol mangling problem
5571 Recent versions of gcc have a bug in how they emit debugging information for
5572 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5573 directory) can be applied to gcc to fix the problem. Alternatively, if you
5574 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5575 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5576 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5579 * New 'maintenance' command
5581 All of the commands related to hacking GDB internals have been moved out of
5582 the main command set, and now live behind the 'maintenance' command. This
5583 can also be abbreviated as 'mt'. The following changes were made:
5585 dump-me -> maintenance dump-me
5586 info all-breakpoints -> maintenance info breakpoints
5587 printmsyms -> maintenance print msyms
5588 printobjfiles -> maintenance print objfiles
5589 printpsyms -> maintenance print psymbols
5590 printsyms -> maintenance print symbols
5592 The following commands are new:
5594 maintenance demangle Call internal GDB demangler routine to
5595 demangle a C++ link name and prints the result.
5596 maintenance print type Print a type chain for a given symbol
5598 * Change to .gdbinit file processing
5600 We now read the $HOME/.gdbinit file before processing the argv arguments
5601 (e.g. reading symbol files or core files). This allows global parameters to
5602 be set, which will apply during the symbol reading. The ./.gdbinit is still
5603 read after argv processing.
5605 * New hosts supported
5607 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5609 GNU/Linux support i386-unknown-linux or linux
5611 We are also including code to support the HP/PA running BSD and HPUX. This
5612 is almost guaranteed not to work, as we didn't have time to test or build it
5613 for this release. We are including it so that the more adventurous (or
5614 masochistic) of you can play with it. We also had major problems with the
5615 fact that the compiler that we got from HP doesn't support the -g option.
5618 * New targets supported
5620 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5622 * More smarts about finding #include files
5624 GDB now remembers the compilation directory for all include files, and for
5625 all files from which C is generated (like yacc and lex sources). This
5626 greatly improves GDB's ability to find yacc/lex sources, and include files,
5627 especially if you are debugging your program from a directory different from
5628 the one that contains your sources.
5630 We also fixed a bug which caused difficulty with listing and setting
5631 breakpoints in include files which contain C code. (In the past, you had to
5632 try twice in order to list an include file that you hadn't looked at before.)
5634 * Interesting infernals change
5636 GDB now deals with arbitrary numbers of sections, where the symbols for each
5637 section must be relocated relative to that section's landing place in the
5638 target's address space. This work was needed to support ELF with embedded
5639 stabs used by Solaris-2.0.
5641 * Bug fixes (of course!)
5643 There have been loads of fixes for the following things:
5644 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5645 i960, stabs, DOS(GO32), procfs, etc...
5647 See the ChangeLog for details.
5649 *** Changes in GDB-4.5:
5651 * New machines supported (host and target)
5653 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5655 SGI Irix-4.x mips-sgi-irix4 or iris4
5657 * New malloc package
5659 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5660 Mmalloc is capable of handling mutiple heaps of memory. It is also
5661 capable of saving a heap to a file, and then mapping it back in later.
5662 This can be used to greatly speedup the startup of GDB by using a
5663 pre-parsed symbol table which lives in a mmalloc managed heap. For
5664 more details, please read mmalloc/mmalloc.texi.
5668 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5669 'help info proc' for details.
5671 * MIPS ecoff symbol table format
5673 The code that reads MIPS symbol table format is now supported on all hosts.
5674 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5677 * File name changes for MS-DOS
5679 Many files in the config directories have been renamed to make it easier to
5680 support GDB on MS-DOSe systems (which have very restrictive file name
5681 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5682 environment) is close to working but has some remaining problems. Note
5683 that debugging of DOS programs is not supported, due to limitations
5684 in the ``operating system'', but it can be used to host cross-debugging.
5686 * Cross byte order fixes
5688 Many fixes have been made to support cross debugging of Sparc and MIPS
5689 targets from hosts whose byte order differs.
5691 * New -mapped and -readnow options
5693 If memory-mapped files are available on your system through the 'mmap'
5694 system call, you can use the -mapped option on the `file' or
5695 `symbol-file' commands to cause GDB to write the symbols from your
5696 program into a reusable file. If the program you are debugging is
5697 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5698 Future GDB debugging sessions will notice the presence of this file,
5699 and will quickly map in symbol information from it, rather than reading
5700 the symbol table from the executable program. Using the '-mapped'
5701 option in a GDB `file' or `symbol-file' command has the same effect as
5702 starting GDB with the '-mapped' command-line option.
5704 You can cause GDB to read the entire symbol table immediately by using
5705 the '-readnow' option with any of the commands that load symbol table
5706 information (or on the GDB command line). This makes the command
5707 slower, but makes future operations faster.
5709 The -mapped and -readnow options are typically combined in order to
5710 build a `fred.syms' file that contains complete symbol information.
5711 A simple GDB invocation to do nothing but build a `.syms' file for future
5714 gdb -batch -nx -mapped -readnow programname
5716 The `.syms' file is specific to the host machine on which GDB is run.
5717 It holds an exact image of GDB's internal symbol table. It cannot be
5718 shared across multiple host platforms.
5720 * longjmp() handling
5722 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5723 siglongjmp() without losing control. This feature has not yet been ported to
5724 all systems. It currently works on many 386 platforms, all MIPS-based
5725 platforms (SGI, DECstation, etc), and Sun3/4.
5729 Preliminary work has been put in to support the new Solaris OS from Sun. At
5730 this time, it can control and debug processes, but it is not capable of
5735 As always, many many bug fixes. The major areas were with g++, and mipsread.
5736 People using the MIPS-based platforms should experience fewer mysterious
5737 crashes and trashed symbol tables.
5739 *** Changes in GDB-4.4:
5741 * New machines supported (host and target)
5743 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5745 BSD Reno on Vax vax-dec-bsd
5746 Ultrix on Vax vax-dec-ultrix
5748 * New machines supported (target)
5750 AMD 29000 embedded, using EBMON a29k-none-none
5754 GDB continues to improve its handling of C++. `References' work better.
5755 The demangler has also been improved, and now deals with symbols mangled as
5756 per the Annotated C++ Reference Guide.
5758 GDB also now handles `stabs' symbol information embedded in MIPS
5759 `ecoff' symbol tables. Since the ecoff format was not easily
5760 extensible to handle new languages such as C++, this appeared to be a
5761 good way to put C++ debugging info into MIPS binaries. This option
5762 will be supported in the GNU C compiler, version 2, when it is
5765 * New features for SVR4
5767 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5768 shared libraries. Debugging dynamically linked programs should present
5769 only minor differences from debugging statically linked programs.
5771 The `info proc' command will print out information about any process
5772 on an SVR4 system (including the one you are debugging). At the moment,
5773 it prints the address mappings of the process.
5775 If you bring up GDB on another SVR4 system, please send mail to
5776 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5778 * Better dynamic linking support in SunOS
5780 Reading symbols from shared libraries which contain debugging symbols
5781 now works properly. However, there remain issues such as automatic
5782 skipping of `transfer vector' code during function calls, which
5783 make it harder to debug code in a shared library, than to debug the
5784 same code linked statically.
5788 GDB is now using the latest `getopt' routines from the FSF. This
5789 version accepts the -- prefix for options with long names. GDB will
5790 continue to accept the old forms (-option and +option) as well.
5791 Various single letter abbreviations for options have been explicity
5792 added to the option table so that they won't get overshadowed in the
5793 future by other options that begin with the same letter.
5797 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5798 Many assorted bugs have been handled. Many more remain to be handled.
5799 See the various ChangeLog files (primarily in gdb and bfd) for details.
5802 *** Changes in GDB-4.3:
5804 * New machines supported (host and target)
5806 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5807 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5808 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5810 * Almost SCO Unix support
5812 We had hoped to support:
5813 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5814 (except for core file support), but we discovered very late in the release
5815 that it has problems with process groups that render gdb unusable. Sorry
5816 about that. I encourage people to fix it and post the fixes.
5818 * Preliminary ELF and DWARF support
5820 GDB can read ELF object files on System V Release 4, and can handle
5821 debugging records for C, in DWARF format, in ELF files. This support
5822 is preliminary. If you bring up GDB on another SVR4 system, please
5823 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5828 GDB now uses the latest `readline' library. One user-visible change
5829 is that two tabs will list possible command completions, which previously
5830 required typing M-? (meta-question mark, or ESC ?).
5834 The `stepi' bug that many of you noticed has been squashed.
5835 Many bugs in C++ have been handled. Many more remain to be handled.
5836 See the various ChangeLog files (primarily in gdb and bfd) for details.
5838 * State of the MIPS world (in case you wondered):
5840 GDB can understand the symbol tables emitted by the compilers
5841 supplied by most vendors of MIPS-based machines, including DEC. These
5842 symbol tables are in a format that essentially nobody else uses.
5844 Some versions of gcc come with an assembler post-processor called
5845 mips-tfile. This program is required if you want to do source-level
5846 debugging of gcc-compiled programs. I believe FSF does not ship
5847 mips-tfile with gcc version 1, but it will eventually come with gcc
5850 Debugging of g++ output remains a problem. g++ version 1.xx does not
5851 really support it at all. (If you're lucky, you should be able to get
5852 line numbers and stack traces to work, but no parameters or local
5853 variables.) With some work it should be possible to improve the
5856 When gcc version 2 is released, you will have somewhat better luck.
5857 However, even then you will get confusing results for inheritance and
5860 We will eventually provide full debugging of g++ output on
5861 DECstations. This will probably involve some kind of stabs-in-ecoff
5862 encapulation, but the details have not been worked out yet.
5865 *** Changes in GDB-4.2:
5867 * Improved configuration
5869 Only one copy of `configure' exists now, and it is not self-modifying.
5870 Porting BFD is simpler.
5874 The `step' and `next' commands now only stop at the first instruction
5875 of a source line. This prevents the multiple stops that used to occur
5876 in switch statements, for-loops, etc. `Step' continues to stop if a
5877 function that has debugging information is called within the line.
5881 Lots of small bugs fixed. More remain.
5883 * New host supported (not target)
5885 Intel 386 PC clone running Mach i386-none-mach
5888 *** Changes in GDB-4.1:
5890 * Multiple source language support
5892 GDB now has internal scaffolding to handle several source languages.
5893 It determines the type of each source file from its filename extension,
5894 and will switch expression parsing and number formatting to match the
5895 language of the function in the currently selected stack frame.
5896 You can also specifically set the language to be used, with
5897 `set language c' or `set language modula-2'.
5901 GDB now has preliminary support for the GNU Modula-2 compiler,
5902 currently under development at the State University of New York at
5903 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5904 continue through the fall of 1991 and into 1992.
5906 Other Modula-2 compilers are currently not supported, and attempting to
5907 debug programs compiled with them will likely result in an error as the
5908 symbol table is read. Feel free to work on it, though!
5910 There are hooks in GDB for strict type checking and range checking,
5911 in the `Modula-2 philosophy', but they do not currently work.
5915 GDB can now write to executable and core files (e.g. patch
5916 a variable's value). You must turn this switch on, specify
5917 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5918 by assigning a new value to a variable. Modifications take
5921 * Automatic SunOS shared library reading
5923 When you run your program, GDB automatically determines where its
5924 shared libraries (if any) have been loaded, and reads their symbols.
5925 The `share' command is no longer needed. This also works when
5926 examining core files.
5930 You can specify the number of lines that the `list' command shows.
5933 * New machines supported (host and target)
5935 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5936 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5937 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5939 * New hosts supported (not targets)
5941 IBM RT/PC: romp-ibm-aix or rtpc
5943 * New targets supported (not hosts)
5945 AMD 29000 embedded with COFF a29k-none-coff
5946 AMD 29000 embedded with a.out a29k-none-aout
5947 Ultracomputer remote kernel debug a29k-nyu-kern
5949 * New remote interfaces
5955 *** Changes in GDB-4.0:
5959 Wide output is wrapped at good places to make the output more readable.
5961 Gdb now supports cross-debugging from a host machine of one type to a
5962 target machine of another type. Communication with the target system
5963 is over serial lines. The ``target'' command handles connecting to the
5964 remote system; the ``load'' command will download a program into the
5965 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5966 also supports debugging of realtime processes running under VxWorks,
5967 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5968 stub on the target system.
5970 New CPUs supported include the AMD 29000 and Intel 960.
5972 GDB now reads object files and symbol tables via a ``binary file''
5973 library, which allows a single copy of GDB to debug programs of multiple
5974 object file types such as a.out and coff.
5976 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5977 refcard.dvi and refcard.ps are available to format it).
5980 * Control-Variable user interface simplified
5982 All variables that control the operation of the debugger can be set
5983 by the ``set'' command, and displayed by the ``show'' command.
5985 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5986 ``Show prompt'' produces the response:
5987 Gdb's prompt is new-gdb=>.
5989 What follows are the NEW set commands. The command ``help set'' will
5990 print a complete list of old and new set commands. ``help set FOO''
5991 will give a longer description of the variable FOO. ``show'' will show
5992 all of the variable descriptions and their current settings.
5994 confirm on/off: Enables warning questions for operations that are
5995 hard to recover from, e.g. rerunning the program while
5996 it is already running. Default is ON.
5998 editing on/off: Enables EMACS style command line editing
5999 of input. Previous lines can be recalled with
6000 control-P, the current line can be edited with control-B,
6001 you can search for commands with control-R, etc.
6004 history filename NAME: NAME is where the gdb command history
6005 will be stored. The default is .gdb_history,
6006 or the value of the environment variable
6009 history size N: The size, in commands, of the command history. The
6010 default is 256, or the value of the environment variable
6013 history save on/off: If this value is set to ON, the history file will
6014 be saved after exiting gdb. If set to OFF, the
6015 file will not be saved. The default is OFF.
6017 history expansion on/off: If this value is set to ON, then csh-like
6018 history expansion will be performed on
6019 command line input. The default is OFF.
6021 radix N: Sets the default radix for input and output. It can be set
6022 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6023 in the current radix, so "set radix 10" is always a no-op.
6025 height N: This integer value is the number of lines on a page. Default
6026 is 24, the current `stty rows'' setting, or the ``li#''
6027 setting from the termcap entry matching the environment
6030 width N: This integer value is the number of characters on a line.
6031 Default is 80, the current `stty cols'' setting, or the ``co#''
6032 setting from the termcap entry matching the environment
6035 Note: ``set screensize'' is obsolete. Use ``set height'' and
6036 ``set width'' instead.
6038 print address on/off: Print memory addresses in various command displays,
6039 such as stack traces and structure values. Gdb looks
6040 more ``symbolic'' if you turn this off; it looks more
6041 ``machine level'' with it on. Default is ON.
6043 print array on/off: Prettyprint arrays. New convenient format! Default
6046 print demangle on/off: Print C++ symbols in "source" form if on,
6049 print asm-demangle on/off: Same, for assembler level printouts
6052 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6055 * Support for Epoch Environment.
6057 The epoch environment is a version of Emacs v18 with windowing. One
6058 new command, ``inspect'', is identical to ``print'', except that if you
6059 are running in the epoch environment, the value is printed in its own
6063 * Support for Shared Libraries
6065 GDB can now debug programs and core files that use SunOS shared libraries.
6066 Symbols from a shared library cannot be referenced
6067 before the shared library has been linked with the program (this
6068 happens after you type ``run'' and before the function main() is entered).
6069 At any time after this linking (including when examining core files
6070 from dynamically linked programs), gdb reads the symbols from each
6071 shared library when you type the ``sharedlibrary'' command.
6072 It can be abbreviated ``share''.
6074 sharedlibrary REGEXP: Load shared object library symbols for files
6075 matching a unix regular expression. No argument
6076 indicates to load symbols for all shared libraries.
6078 info sharedlibrary: Status of loaded shared libraries.
6083 A watchpoint stops execution of a program whenever the value of an
6084 expression changes. Checking for this slows down execution
6085 tremendously whenever you are in the scope of the expression, but is
6086 quite useful for catching tough ``bit-spreader'' or pointer misuse
6087 problems. Some machines such as the 386 have hardware for doing this
6088 more quickly, and future versions of gdb will use this hardware.
6090 watch EXP: Set a watchpoint (breakpoint) for an expression.
6092 info watchpoints: Information about your watchpoints.
6094 delete N: Deletes watchpoint number N (same as breakpoints).
6095 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6096 enable N: Re-enables watchpoint number N (same as breakpoints).
6099 * C++ multiple inheritance
6101 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6104 * C++ exception handling
6106 Gdb now supports limited C++ exception handling. Besides the existing
6107 ability to breakpoint on an exception handler, gdb can breakpoint on
6108 the raising of an exception (before the stack is peeled back to the
6111 catch FOO: If there is a FOO exception handler in the dynamic scope,
6112 set a breakpoint to catch exceptions which may be raised there.
6113 Multiple exceptions (``catch foo bar baz'') may be caught.
6115 info catch: Lists all exceptions which may be caught in the
6116 current stack frame.
6119 * Minor command changes
6121 The command ``call func (arg, arg, ...)'' now acts like the print
6122 command, except it does not print or save a value if the function's result
6123 is void. This is similar to dbx usage.
6125 The ``up'' and ``down'' commands now always print the frame they end up
6126 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6127 frames without printing.
6129 * New directory command
6131 'dir' now adds directories to the FRONT of the source search path.
6132 The path starts off empty. Source files that contain debug information
6133 about the directory in which they were compiled can be found even
6134 with an empty path; Sun CC and GCC include this information. If GDB can't
6135 find your source file in the current directory, type "dir .".
6137 * Configuring GDB for compilation
6139 For normal use, type ``./configure host''. See README or gdb.texinfo
6142 GDB now handles cross debugging. If you are remotely debugging between
6143 two different machines, type ``./configure host -target=targ''.
6144 Host is the machine where GDB will run; targ is the machine
6145 where the program that you are debugging will run.