1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.10
6 * The new convenience variable $_inferior holds the number of the
9 * Record btrace now supports non-stop mode.
11 * Support for tracepoints on aarch64-linux was added in GDBserver.
13 * The 'record instruction-history' command now indicates speculative execution
14 when using the Intel Processor Trace recording format.
16 * GDB now allows users to specify explicit locations, bypassing
17 the linespec parser. This feature is also available to GDB/MI
20 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
21 GDB now is able to debug both AArch64 applications and ARM applications
24 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
25 including JIT compiling fast tracepoint's conditional expression bytecode
28 * GDB now supports displaced stepping on AArch64 GNU/Linux.
30 * "info threads", "info inferiors", "info display", "info checkpoints"
31 and "maint info program-spaces" now list the corresponding items in
32 ascending ID order, for consistency with all other "info" commands.
34 * In Ada, the overloads selection menu has been enhanced to display the
35 parameter types and the return types for the matching overloaded subprograms.
39 maint set target-non-stop (on|off|auto)
40 maint show target-non-stop
41 Control whether GDB targets always operate in non-stop mode even if
42 "set non-stop" is "off". The default is "auto", meaning non-stop
43 mode is enabled if supported by the target.
46 maint show bfd-sharing
47 Control the reuse of bfd objects.
51 Control display of debugging info regarding bfd caching.
53 set remote multiprocess-extensions-packet
54 show remote multiprocess-extensions-packet
55 Set/show the use of the remote protocol multiprocess extensions.
57 set remote thread-events
58 show remote thread-events
59 Set/show the use of thread create/exit events.
61 set ada print-signatures on|off
62 show ada print-signatures"
63 Control whether parameter types and return types are displayed in overloads
64 selection menus. It is activaled (@code{on}) by default.
66 * The "disassemble" command accepts a new modifier: /s.
67 It prints mixed source+disassembly like /m with two differences:
68 - disassembled instructions are now printed in program order, and
69 - and source for all relevant files is now printed.
70 The "/m" option is now considered deprecated: its "source-centric"
71 output hasn't proved useful in practice.
73 * The "record instruction-history" command accepts a new modifier: /s.
74 It behaves exactly like /m and prints mixed source+disassembly.
76 * The "set scheduler-locking" command supports a new mode "replay".
77 It behaves like "off" in record mode and like "on" in replay mode.
79 * Support for various ROM monitors has been removed:
81 target dbug dBUG ROM monitor for Motorola ColdFire
82 target picobug Motorola picobug monitor
83 target dink32 DINK32 ROM monitor for PowerPC
84 target m32r Renesas M32R/D ROM monitor
85 target mon2000 mon2000 ROM monitor
86 target ppcbug PPCBUG ROM monitor for PowerPC
88 * Support for reading/writing memory and extracting values on architectures
89 whose memory is addressable in units of any integral multiple of 8 bits.
94 Indicates that an exec system call was executed.
96 exec-events feature in qSupported
97 The qSupported packet allows GDB to request support for exec
98 events using the new 'gdbfeature' exec-event, and the qSupported
99 response can contain the corresponding 'stubfeature'. Set and
100 show commands can be used to display whether these features are enabled.
103 Equivalent to interrupting with the ^C character, but works in
106 thread created stop reason (T05 create:...)
107 Indicates that the thread was just created and is stopped at entry.
109 thread exit stop reply (w exitcode;tid)
110 Indicates that the thread has terminated.
113 Enables/disables thread create and exit event reporting. For
114 example, this is used in non-stop mode when GDB stops a set of
115 threads and synchronously waits for the their corresponding stop
116 replies. Without exit events, if one of the threads exits, GDB
117 would hang forever not knowing that it should no longer expect a
118 stop for that same thread.
122 Indicates that there are no resumed threads left in the target (all
123 threads are stopped). The remote stub reports support for this stop
124 reply to GDB's qSupported query.
126 QCatchSyscalls:1 [;SYSNO]...
128 Enable ("QCatchSyscalls:1") or disable ("QCatchSyscalls:0")
129 catching syscalls from the inferior process.
131 syscall_entry stop reason
132 Indicates that a syscall was just called.
134 syscall_return stop reason
135 Indicates that a syscall just returned.
137 QCatchSyscalls:1 in qSupported
138 The qSupported packet may now include QCatchSyscalls:1 in the reply
139 to indicate support for catching syscalls.
141 * Extended-remote exec events
143 ** GDB now has support for exec events on extended-remote Linux targets.
144 For such targets with Linux kernels 2.5.46 and later, this enables
145 follow-exec-mode and exec catchpoints.
147 set remote exec-event-feature-packet
148 show remote exec-event-feature-packet
149 Set/show the use of the remote exec event feature.
151 * Thread names in remote protocol
153 The reply to qXfer:threads:read may now include a name attribute for each
156 * Target remote mode fork and exec events
158 ** GDB now has support for fork and exec events on target remote mode
159 Linux targets. For such targets with Linux kernels 2.5.46 and later,
160 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
161 fork and exec catchpoints.
163 * Remote syscall events
165 ** GDB now has support for catch syscall on remote Linux targets,
166 currently enabled on x86/x86_64 architectures.
168 set remote catch-syscall-packet
169 show remote catch-syscall-packet
170 Set/show the use of the remote catch syscall feature.
174 ** The -var-set-format command now accepts the zero-hexadecimal
175 format. It outputs data in hexadecimal format with zero-padding on the
178 *** Changes in GDB 7.10
180 * Support for process record-replay and reverse debugging on aarch64*-linux*
181 targets has been added. GDB now supports recording of A64 instruction set
182 including advance SIMD instructions.
184 * Support for Sun's version of the "stabs" debug file format has been removed.
186 * GDB now honors the content of the file /proc/PID/coredump_filter
187 (PID is the process ID) on GNU/Linux systems. This file can be used
188 to specify the types of memory mappings that will be included in a
189 corefile. For more information, please refer to the manual page of
190 "core(5)". GDB also has a new command: "set use-coredump-filter
191 on|off". It allows to set whether GDB will read the content of the
192 /proc/PID/coredump_filter file when generating a corefile.
194 * The "info os" command on GNU/Linux can now display information on
196 "info os cpus" Listing of all cpus/cores on the system
198 * GDB has two new commands: "set serial parity odd|even|none" and
199 "show serial parity". These allows to set or show parity for the
202 * The "info source" command now displays the producer string if it was
203 present in the debug info. This typically includes the compiler version
204 and may include things like its command line arguments.
206 * The "info dll", an alias of the "info sharedlibrary" command,
207 is now available on all platforms.
209 * Directory names supplied to the "set sysroot" commands may be
210 prefixed with "target:" to tell GDB to access shared libraries from
211 the target system, be it local or remote. This replaces the prefix
212 "remote:". The default sysroot has been changed from "" to
213 "target:". "remote:" is automatically converted to "target:" for
214 backward compatibility.
216 * The system root specified by "set sysroot" will be prepended to the
217 filename of the main executable (if reported to GDB as absolute by
218 the operating system) when starting processes remotely, and when
219 attaching to already-running local or remote processes.
221 * GDB now supports automatic location and retrieval of executable
222 files from remote targets. Remote debugging can now be initiated
223 using only a "target remote" or "target extended-remote" command
224 (no "set sysroot" or "file" commands are required). See "New remote
227 * The "dump" command now supports verilog hex format.
229 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
231 * On GNU/Linux, GDB and gdbserver are now able to access executable
232 and shared library files without a "set sysroot" command when
233 attaching to processes running in different mount namespaces from
234 the debugger. This makes it possible to attach to processes in
235 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
236 See "New remote packets" below.
238 * The "tui reg" command now provides completion for all of the
239 available register groups, including target specific groups.
241 * The HISTSIZE environment variable is no longer read when determining
242 the size of GDB's command history. GDB now instead reads the dedicated
243 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
244 disables truncation of command history. Non-numeric values of GDBHISTSIZE
249 ** Memory ports can now be unbuffered.
253 ** gdb.Objfile objects have a new attribute "username",
254 which is the name of the objfile as specified by the user,
255 without, for example, resolving symlinks.
256 ** You can now write frame unwinders in Python.
257 ** gdb.Type objects have a new method "optimized_out",
258 returning optimized out gdb.Value instance of this type.
259 ** gdb.Value objects have new methods "reference_value" and
260 "const_value" which return a reference to the value and a
261 "const" version of the value respectively.
265 maint print symbol-cache
266 Print the contents of the symbol cache.
268 maint print symbol-cache-statistics
269 Print statistics of symbol cache usage.
271 maint flush-symbol-cache
272 Flush the contents of the symbol cache.
276 Start branch trace recording using Branch Trace Store (BTS) format.
279 Evaluate expression by using the compiler and print result.
283 Explicit commands for enabling and disabling tui mode.
286 set mpx bound on i386 and amd64
287 Support for bound table investigation on Intel MPX enabled applications.
291 Start branch trace recording using Intel Processor Trace format.
294 Print information about branch tracing internals.
296 maint btrace packet-history
297 Print the raw branch tracing data.
299 maint btrace clear-packet-history
300 Discard the stored raw branch tracing data.
303 Discard all branch tracing data. It will be fetched and processed
304 anew by the next "record" command.
309 Renamed from "set debug dwarf2-die".
311 Renamed from "show debug dwarf2-die".
314 Renamed from "set debug dwarf2-read".
315 show debug dwarf-read
316 Renamed from "show debug dwarf2-read".
318 maint set dwarf always-disassemble
319 Renamed from "maint set dwarf2 always-disassemble".
320 maint show dwarf always-disassemble
321 Renamed from "maint show dwarf2 always-disassemble".
323 maint set dwarf max-cache-age
324 Renamed from "maint set dwarf2 max-cache-age".
325 maint show dwarf max-cache-age
326 Renamed from "maint show dwarf2 max-cache-age".
329 show debug dwarf-line
330 Control display of debugging info regarding DWARF line processing.
334 Set the maximum number of candidates to be considered during
335 completion. The default value is 200. This limit allows GDB
336 to avoid generating large completion lists, the computation of
337 which can cause the debugger to become temporarily unresponsive.
339 set history remove-duplicates
340 show history remove-duplicates
341 Control the removal of duplicate history entries.
343 maint set symbol-cache-size
344 maint show symbol-cache-size
345 Control the size of the symbol cache.
347 set|show record btrace bts buffer-size
348 Set and show the size of the ring buffer used for branch tracing in
350 The obtained size may differ from the requested size. Use "info
351 record" to see the obtained buffer size.
353 set debug linux-namespaces
354 show debug linux-namespaces
355 Control display of debugging info regarding Linux namespaces.
357 set|show record btrace pt buffer-size
358 Set and show the size of the ring buffer used for branch tracing in
359 Intel Processor Trace format.
360 The obtained size may differ from the requested size. Use "info
361 record" to see the obtained buffer size.
363 maint set|show btrace pt skip-pad
364 Set and show whether PAD packets are skipped when computing the
367 * The command 'thread apply all' can now support new option '-ascending'
368 to call its specified command for all threads in ascending order.
370 * Python/Guile scripting
372 ** GDB now supports auto-loading of Python/Guile scripts contained in the
373 special section named `.debug_gdb_scripts'.
377 qXfer:btrace-conf:read
378 Return the branch trace configuration for the current thread.
380 Qbtrace-conf:bts:size
381 Set the requested ring buffer size for branch tracing in BTS format.
384 Enable Intel Procesor Trace-based branch tracing for the current
385 process. The remote stub reports support for this packet to GDB's
389 Set the requested ring buffer size for branch tracing in Intel Processor
393 Indicates a memory breakpoint instruction was executed, irrespective
394 of whether it was GDB that planted the breakpoint or the breakpoint
395 is hardcoded in the program. This is required for correct non-stop
399 Indicates the target stopped for a hardware breakpoint. This is
400 required for correct non-stop mode operation.
403 Return information about files on the remote system.
406 Return the full absolute name of the file that was executed to
407 create a process running on the remote system.
410 Select the filesystem on which vFile: operations with filename
411 arguments will operate. This is required for GDB to be able to
412 access files on remote targets where the remote stub does not
413 share a common filesystem with the inferior(s).
416 Indicates that a fork system call was executed.
419 Indicates that a vfork system call was executed.
421 vforkdone stop reason
422 Indicates that a vfork child of the specified process has executed
423 an exec or exit, allowing the vfork parent to resume execution.
425 fork-events and vfork-events features in qSupported
426 The qSupported packet allows GDB to request support for fork and
427 vfork events using new 'gdbfeatures' fork-events and vfork-events,
428 and the qSupported response can contain the corresponding
429 'stubfeatures'. Set and show commands can be used to display
430 whether these features are enabled.
432 * Extended-remote fork events
434 ** GDB now has support for fork events on extended-remote Linux
435 targets. For targets with Linux kernels 2.5.60 and later, this
436 enables follow-fork-mode and detach-on-fork for both fork and
437 vfork, as well as fork and vfork catchpoints.
439 * The info record command now shows the recording format and the
440 branch tracing configuration for the current thread when using
441 the btrace record target.
442 For the BTS format, it shows the ring buffer size.
444 * GDB now has support for DTrace USDT (Userland Static Defined
445 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
447 * GDB now supports access to vector registers on S/390 GNU/Linux
450 * Removed command line options
452 -xdb HP-UX XDB compatibility mode.
454 * Removed targets and native configurations
456 HP/PA running HP-UX hppa*-*-hpux*
457 Itanium running HP-UX ia64-*-hpux*
459 * New configure options
462 This configure option allows the user to build GDB with support for
463 Intel Processor Trace (default: auto). This requires libipt.
465 --with-libipt-prefix=PATH
466 Specify the path to the version of libipt that GDB should use.
467 $PATH/include should contain the intel-pt.h header and
468 $PATH/lib should contain the libipt.so library.
470 *** Changes in GDB 7.9.1
474 ** Xmethods can now specify a result type.
476 *** Changes in GDB 7.9
478 * GDB now supports hardware watchpoints on x86 GNU Hurd.
482 ** You can now access frame registers from Python scripts.
483 ** New attribute 'producer' for gdb.Symtab objects.
484 ** gdb.Objfile objects have a new attribute "progspace",
485 which is the gdb.Progspace object of the containing program space.
486 ** gdb.Objfile objects have a new attribute "owner".
487 ** gdb.Objfile objects have a new attribute "build_id",
488 which is the build ID generated when the file was built.
489 ** gdb.Objfile objects have a new method "add_separate_debug_file".
490 ** A new event "gdb.clear_objfiles" has been added, triggered when
491 selecting a new file to debug.
492 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
493 ** New function gdb.lookup_objfile.
495 New events which are triggered when GDB modifies the state of the
498 ** gdb.events.inferior_call_pre: Function call is about to be made.
499 ** gdb.events.inferior_call_post: Function call has just been made.
500 ** gdb.events.memory_changed: A memory location has been altered.
501 ** gdb.events.register_changed: A register has been altered.
503 * New Python-based convenience functions:
505 ** $_caller_is(name [, number_of_frames])
506 ** $_caller_matches(regexp [, number_of_frames])
507 ** $_any_caller_is(name [, number_of_frames])
508 ** $_any_caller_matches(regexp [, number_of_frames])
510 * GDB now supports the compilation and injection of source code into
511 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
512 to compile the source code to object code, and if successful, inject
513 and execute that code within the current context of the inferior.
514 Currently the C language is supported. The commands used to
515 interface with this new feature are:
517 compile code [-raw|-r] [--] [source code]
518 compile file [-raw|-r] filename
522 demangle [-l language] [--] name
523 Demangle "name" in the specified language, or the current language
524 if elided. This command is renamed from the "maint demangle" command.
525 The latter is kept as a no-op to avoid "maint demangle" being interpreted
526 as "maint demangler-warning".
528 queue-signal signal-name-or-number
529 Queue a signal to be delivered to the thread when it is resumed.
531 add-auto-load-scripts-directory directory
532 Add entries to the list of directories from which to load auto-loaded
535 maint print user-registers
536 List all currently available "user" registers.
538 compile code [-r|-raw] [--] [source code]
539 Compile, inject, and execute in the inferior the executable object
540 code produced by compiling the provided source code.
542 compile file [-r|-raw] filename
543 Compile and inject into the inferior the executable object code
544 produced by compiling the source code stored in the filename
547 * On resume, GDB now always passes the signal the program had stopped
548 for to the thread the signal was sent to, even if the user changed
549 threads before resuming. Previously GDB would often (but not
550 always) deliver the signal to the thread that happens to be current
553 * Conversely, the "signal" command now consistently delivers the
554 requested signal to the current thread. GDB now asks for
555 confirmation if the program had stopped for a signal and the user
556 switched threads meanwhile.
558 * "breakpoint always-inserted" modes "off" and "auto" merged.
560 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
561 won't remove breakpoints from the target until all threads stop,
562 even in non-stop mode. The "auto" mode has been removed, and "off"
563 is now the default mode.
567 set debug symbol-lookup
568 show debug symbol-lookup
569 Control display of debugging info regarding symbol lookup.
573 ** The -list-thread-groups command outputs an exit-code field for
574 inferiors that have exited.
578 MIPS SDE mips*-sde*-elf*
582 Support for these obsolete configurations has been removed.
584 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
585 SGI Irix-5.x mips-*-irix5*
586 SGI Irix-6.x mips-*-irix6*
587 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
588 VAX running Ultrix vax-*-ultrix*
590 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
591 and "assf"), have been removed. Use the "sharedlibrary" command, or
592 its alias "share", instead.
594 *** Changes in GDB 7.8
596 * New command line options
599 This is an alias for the --data-directory option.
601 * GDB supports printing and modifying of variable length automatic arrays
602 as specified in ISO C99.
604 * The ARM simulator now supports instruction level tracing
605 with or without disassembly.
609 GDB now has support for scripting using Guile. Whether this is
610 available is determined at configure time.
611 Guile version 2.0 or greater is required.
612 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
614 * New commands (for set/show, see "New options" below)
618 Invoke CODE by passing it to the Guile interpreter.
622 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
624 info auto-load guile-scripts [regexp]
625 Print the list of automatically loaded Guile scripts.
627 * The source command is now capable of sourcing Guile scripts.
628 This feature is dependent on the debugger being built with Guile support.
632 set print symbol-loading (off|brief|full)
633 show print symbol-loading
634 Control whether to print informational messages when loading symbol
635 information for a file. The default is "full", but when debugging
636 programs with large numbers of shared libraries the amount of output
639 set guile print-stack (none|message|full)
640 show guile print-stack
641 Show a stack trace when an error is encountered in a Guile script.
643 set auto-load guile-scripts (on|off)
644 show auto-load guile-scripts
645 Control auto-loading of Guile script files.
647 maint ada set ignore-descriptive-types (on|off)
648 maint ada show ignore-descriptive-types
649 Control whether the debugger should ignore descriptive types in Ada
650 programs. The default is not to ignore the descriptive types. See
651 the user manual for more details on descriptive types and the intended
652 usage of this option.
654 set auto-connect-native-target
656 Control whether GDB is allowed to automatically connect to the
657 native target for the run, attach, etc. commands when not connected
658 to any target yet. See also "target native" below.
660 set record btrace replay-memory-access (read-only|read-write)
661 show record btrace replay-memory-access
662 Control what memory accesses are allowed during replay.
664 maint set target-async (on|off)
665 maint show target-async
666 This controls whether GDB targets operate in synchronous or
667 asynchronous mode. Normally the default is asynchronous, if it is
668 available; but this can be changed to more easily debug problems
669 occurring only in synchronous mode.
671 set mi-async (on|off)
673 Control whether MI asynchronous mode is preferred. This supersedes
674 "set target-async" of previous GDB versions.
676 * "set target-async" is deprecated as a CLI option and is now an alias
677 for "set mi-async" (only puts MI into async mode).
679 * Background execution commands (e.g., "c&", "s&", etc.) are now
680 possible ``out of the box'' if the target supports them. Previously
681 the user would need to explicitly enable the possibility with the
682 "set target-async on" command.
684 * New features in the GDB remote stub, GDBserver
686 ** New option --debug-format=option1[,option2,...] allows one to add
687 additional text to each output. At present only timestamps
688 are supported: --debug-format=timestamps.
689 Timestamps can also be turned on with the
690 "monitor set debug-format timestamps" command from GDB.
692 * The 'record instruction-history' command now starts counting instructions
693 at one. This also affects the instruction ranges reported by the
694 'record function-call-history' command when given the /i modifier.
696 * The command 'record function-call-history' supports a new modifier '/c' to
697 indent the function names based on their call stack depth.
698 The fields for the '/i' and '/l' modifier have been reordered.
699 The source line range is now prefixed with 'at'.
700 The instruction range is now prefixed with 'inst'.
701 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
702 "record instruction-history" and "list" commands.
704 * The ranges given as arguments to the 'record function-call-history' and
705 'record instruction-history' commands are now inclusive.
707 * The btrace record target now supports the 'record goto' command.
708 For locations inside the execution trace, the back trace is computed
709 based on the information stored in the execution trace.
711 * The btrace record target supports limited reverse execution and replay.
712 The target does not record data and therefore does not allow reading
715 * The "catch syscall" command now works on s390*-linux* targets.
717 * The "compare-sections" command is no longer specific to target
718 remote. It now works with all targets.
720 * All native targets are now consistently called "native".
721 Consequently, the "target child", "target GNU", "target djgpp",
722 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
723 commands have been replaced with "target native". The QNX/NTO port
724 leaves the "procfs" target in place and adds a "native" target for
725 consistency with other ports. The impact on users should be minimal
726 as these commands previously either throwed an error, or were
727 no-ops. The target's name is visible in the output of the following
728 commands: "help target", "info target", "info files", "maint print
731 * The "target native" command now connects to the native target. This
732 can be used to launch native programs even when "set
733 auto-connect-native-target" is set to off.
735 * GDB now supports access to Intel MPX registers on GNU/Linux.
737 * Support for Intel AVX-512 registers on GNU/Linux.
738 Support displaying and modifying Intel AVX-512 registers
739 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
743 qXfer:btrace:read's annex
744 The qXfer:btrace:read packet supports a new annex 'delta' to read
745 branch trace incrementally.
749 ** Valid Python operations on gdb.Value objects representing
750 structs/classes invoke the corresponding overloaded operators if
752 ** New `Xmethods' feature in the Python API. Xmethods are
753 additional methods or replacements for existing methods of a C++
754 class. This feature is useful for those cases where a method
755 defined in C++ source code could be inlined or optimized out by
756 the compiler, making it unavailable to GDB.
759 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
761 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
762 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
763 its alias "share", instead.
765 * The commands "set remotebaud" and "show remotebaud" are no longer
766 supported. Use "set serial baud" and "show serial baud" (respectively)
771 ** A new option "-gdb-set mi-async" replaces "-gdb-set
772 target-async". The latter is left as a deprecated alias of the
773 former for backward compatibility. If the target supports it,
774 CLI background execution commands are now always possible by
775 default, independently of whether the frontend stated a
776 preference for asynchronous execution with "-gdb-set mi-async".
777 Previously "-gdb-set target-async off" affected both MI execution
778 commands and CLI execution commands.
780 *** Changes in GDB 7.7
782 * Improved support for process record-replay and reverse debugging on
783 arm*-linux* targets. Support for thumb32 and syscall instruction
784 recording has been added.
786 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
788 * GDB now supports Fission DWP file format version 2.
789 http://gcc.gnu.org/wiki/DebugFission
791 * New convenience function "$_isvoid", to check whether an expression
792 is void. A void expression is an expression where the type of the
793 result is "void". For example, some convenience variables may be
794 "void" when evaluated (e.g., "$_exitcode" before the execution of
795 the program being debugged; or an undefined convenience variable).
796 Another example, when calling a function whose return type is
799 * The "maintenance print objfiles" command now takes an optional regexp.
801 * The "catch syscall" command now works on arm*-linux* targets.
803 * GDB now consistently shows "<not saved>" when printing values of
804 registers the debug info indicates have not been saved in the frame
805 and there's nowhere to retrieve them from
806 (callee-saved/call-clobbered registers):
811 (gdb) info registers rax
814 Before, the former would print "<optimized out>", and the latter
815 "*value not available*".
817 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
822 ** Frame filters and frame decorators have been added.
823 ** Temporary breakpoints are now supported.
824 ** Line tables representation has been added.
825 ** New attribute 'parent_type' for gdb.Field objects.
826 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
827 ** New attribute 'name' for gdb.Type objects.
831 Nios II ELF nios2*-*-elf
832 Nios II GNU/Linux nios2*-*-linux
833 Texas Instruments MSP430 msp430*-*-elf
835 * Removed native configurations
837 Support for these a.out NetBSD and OpenBSD obsolete configurations has
838 been removed. ELF variants of these configurations are kept supported.
840 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
841 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
842 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
843 i[34567]86-*-openbsd3.[0-3]
844 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
845 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
846 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
850 Like "catch throw", but catches a re-thrown exception.
852 Renamed from old "maint check-symtabs".
854 Perform consistency checks on symtabs.
856 Expand symtabs matching an optional regexp.
859 Display the details of GDB configure-time options.
861 maint set|show per-command
862 maint set|show per-command space
863 maint set|show per-command time
864 maint set|show per-command symtab
865 Enable display of per-command gdb resource usage.
867 remove-symbol-file FILENAME
868 remove-symbol-file -a ADDRESS
869 Remove a symbol file added via add-symbol-file. The file to remove
870 can be identified by its filename or by an address that lies within
871 the boundaries of this symbol file in memory.
874 info exceptions REGEXP
875 Display the list of Ada exceptions defined in the program being
876 debugged. If provided, only the exceptions whose names match REGEXP
881 set debug symfile off|on
883 Control display of debugging info regarding reading symbol files and
884 symbol tables within those files
886 set print raw frame-arguments
887 show print raw frame-arguments
888 Set/show whether to print frame arguments in raw mode,
889 disregarding any defined pretty-printers.
891 set remote trace-status-packet
892 show remote trace-status-packet
893 Set/show the use of remote protocol qTStatus packet.
897 Control display of debugging messages related to Nios II targets.
901 Control whether target-assisted range stepping is enabled.
903 set startup-with-shell
904 show startup-with-shell
905 Specifies whether Unix child processes are started via a shell or
910 Use the target memory cache for accesses to the code segment. This
911 improves performance of remote debugging (particularly disassembly).
913 * You can now use a literal value 'unlimited' for options that
914 interpret 0 or -1 as meaning "unlimited". E.g., "set
915 trace-buffer-size unlimited" is now an alias for "set
916 trace-buffer-size -1" and "set height unlimited" is now an alias for
919 * The "set debug symtab-create" debugging option of GDB has been changed to
920 accept a verbosity level. 0 means "off", 1 provides basic debugging
921 output, and values of 2 or greater provides more verbose output.
923 * New command-line options
925 Display the details of GDB configure-time options.
927 * The command 'tsave' can now support new option '-ctf' to save trace
928 buffer in Common Trace Format.
930 * Newly installed $prefix/bin/gcore acts as a shell interface for the
933 * GDB now implements the the C++ 'typeid' operator.
935 * The new convenience variable $_exception holds the exception being
936 thrown or caught at an exception-related catchpoint.
938 * The exception-related catchpoints, like "catch throw", now accept a
939 regular expression which can be used to filter exceptions by type.
941 * The new convenience variable $_exitsignal is automatically set to
942 the terminating signal number when the program being debugged dies
943 due to an uncaught signal.
947 ** All MI commands now accept an optional "--language" option.
948 Support for this feature can be verified by using the "-list-features"
949 command, which should contain "language-option".
951 ** The new command -info-gdb-mi-command allows the user to determine
952 whether a GDB/MI command is supported or not.
954 ** The "^error" result record returned when trying to execute an undefined
955 GDB/MI command now provides a variable named "code" whose content is the
956 "undefined-command" error code. Support for this feature can be verified
957 by using the "-list-features" command, which should contain
958 "undefined-command-error-code".
960 ** The -trace-save MI command can optionally save trace buffer in Common
963 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
965 ** The command -data-list-register-values now accepts an optional
966 "--skip-unavailable" option. When used, only the available registers
969 ** The new command -trace-frame-collected dumps collected variables,
970 computed expressions, tvars, memory and registers in a traceframe.
972 ** The commands -stack-list-locals, -stack-list-arguments and
973 -stack-list-variables now accept an option "--skip-unavailable".
974 When used, only the available locals or arguments are displayed.
976 ** The -exec-run command now accepts an optional "--start" option.
977 When used, the command follows the same semantics as the "start"
978 command, stopping the program's execution at the start of its
979 main subprogram. Support for this feature can be verified using
980 the "-list-features" command, which should contain
981 "exec-run-start-option".
983 ** The new commands -catch-assert and -catch-exceptions insert
984 catchpoints stopping the program when Ada exceptions are raised.
986 ** The new command -info-ada-exceptions provides the equivalent of
987 the new "info exceptions" command.
989 * New system-wide configuration scripts
990 A GDB installation now provides scripts suitable for use as system-wide
991 configuration scripts for the following systems:
995 * GDB now supports target-assigned range stepping with remote targets.
996 This improves the performance of stepping source lines by reducing
997 the number of control packets from/to GDB. See "New remote packets"
1000 * GDB now understands the element 'tvar' in the XML traceframe info.
1001 It has the id of the collected trace state variables.
1003 * On S/390 targets that provide the transactional-execution feature,
1004 the program interruption transaction diagnostic block (TDB) is now
1005 represented as a number of additional "registers" in GDB.
1007 * New remote packets
1011 The vCont packet supports a new 'r' action, that tells the remote
1012 stub to step through an address range itself, without GDB
1013 involvemement at each single-step.
1015 qXfer:libraries-svr4:read's annex
1016 The previously unused annex of the qXfer:libraries-svr4:read packet
1017 is now used to support passing an argument list. The remote stub
1018 reports support for this argument list to GDB's qSupported query.
1019 The defined arguments are "start" and "prev", used to reduce work
1020 necessary for library list updating, resulting in significant
1023 * New features in the GDB remote stub, GDBserver
1025 ** GDBserver now supports target-assisted range stepping. Currently
1026 enabled on x86/x86_64 GNU/Linux targets.
1028 ** GDBserver now adds element 'tvar' in the XML in the reply to
1029 'qXfer:traceframe-info:read'. It has the id of the collected
1030 trace state variables.
1032 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1035 * New 'z' formatter for printing and examining memory, this displays the
1036 value as hexadecimal zero padded on the left to the size of the type.
1038 * GDB can now use Windows x64 unwinding data.
1040 * The "set remotebaud" command has been replaced by "set serial baud".
1041 Similarly, "show remotebaud" has been replaced by "show serial baud".
1042 The "set remotebaud" and "show remotebaud" commands are still available
1043 to provide backward compatibility with older versions of GDB.
1045 *** Changes in GDB 7.6
1047 * Target record has been renamed to record-full.
1048 Record/replay is now enabled with the "record full" command.
1049 This also affects settings that are associated with full record/replay
1050 that have been moved from "set/show record" to "set/show record full":
1052 set|show record full insn-number-max
1053 set|show record full stop-at-limit
1054 set|show record full memory-query
1056 * A new record target "record-btrace" has been added. The new target
1057 uses hardware support to record the control-flow of a process. It
1058 does not support replaying the execution, but it implements the
1059 below new commands for investigating the recorded execution log.
1060 This new recording method can be enabled using:
1064 The "record-btrace" target is only available on Intel Atom processors
1065 and requires a Linux kernel 2.6.32 or later.
1067 * Two new commands have been added for record/replay to give information
1068 about the recorded execution without having to replay the execution.
1069 The commands are only supported by "record btrace".
1071 record instruction-history prints the execution history at
1072 instruction granularity
1074 record function-call-history prints the execution history at
1075 function granularity
1077 * New native configurations
1079 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1080 FreeBSD/powerpc powerpc*-*-freebsd
1081 x86_64/Cygwin x86_64-*-cygwin*
1082 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1086 ARM AArch64 aarch64*-*-elf
1087 ARM AArch64 GNU/Linux aarch64*-*-linux
1088 Lynx 178 PowerPC powerpc-*-lynx*178
1089 x86_64/Cygwin x86_64-*-cygwin*
1090 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1092 * If the configured location of system.gdbinit file (as given by the
1093 --with-system-gdbinit option at configure time) is in the
1094 data-directory (as specified by --with-gdb-datadir at configure
1095 time) or in one of its subdirectories, then GDB will look for the
1096 system-wide init file in the directory specified by the
1097 --data-directory command-line option.
1099 * New command line options:
1101 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1102 other initialization files, unlike -nx which disables all of them.
1104 * Removed command line options
1106 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1109 * The 'ptype' and 'whatis' commands now accept an argument to control
1112 * 'info proc' now works on some core files.
1116 ** Vectors can be created with gdb.Type.vector.
1118 ** Python's atexit.register now works in GDB.
1120 ** Types can be pretty-printed via a Python API.
1122 ** Python 3 is now supported (in addition to Python 2.4 or later)
1124 ** New class gdb.Architecture exposes GDB's internal representation
1125 of architecture in the Python API.
1127 ** New method Frame.architecture returns the gdb.Architecture object
1128 corresponding to the frame's architecture.
1130 * New Python-based convenience functions:
1132 ** $_memeq(buf1, buf2, length)
1133 ** $_streq(str1, str2)
1135 ** $_regex(str, regex)
1137 * The 'cd' command now defaults to using '~' (the home directory) if not
1140 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1141 default for GCC since November 2000.
1143 * The command 'forward-search' can now be abbreviated as 'fo'.
1145 * The command 'info tracepoints' can now display 'installed on target'
1146 or 'not installed on target' for each non-pending location of tracepoint.
1148 * New configure options
1150 --enable-libmcheck/--disable-libmcheck
1151 By default, development versions are built with -lmcheck on hosts
1152 that support it, in order to help track memory corruption issues.
1153 Release versions, on the other hand, are built without -lmcheck
1154 by default. The --enable-libmcheck/--disable-libmcheck configure
1155 options allow the user to override that default.
1156 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1157 This configure option allows the user to build GDB with
1158 libbabeltrace using which GDB can read Common Trace Format data.
1160 * New commands (for set/show, see "New options" below)
1163 Catch signals. This is similar to "handle", but allows commands and
1164 conditions to be attached.
1167 List the BFDs known to GDB.
1169 python-interactive [command]
1171 Start a Python interactive prompt, or evaluate the optional command
1172 and print the result of expressions.
1175 "py" is a new alias for "python".
1177 enable type-printer [name]...
1178 disable type-printer [name]...
1179 Enable or disable type printers.
1183 ** For the Renesas Super-H architecture, the "regs" command has been removed
1184 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1189 set print type methods (on|off)
1190 show print type methods
1191 Control whether method declarations are displayed by "ptype".
1192 The default is to show them.
1194 set print type typedefs (on|off)
1195 show print type typedefs
1196 Control whether typedef definitions are displayed by "ptype".
1197 The default is to show them.
1199 set filename-display basename|relative|absolute
1200 show filename-display
1201 Control the way in which filenames is displayed.
1202 The default is "relative", which preserves previous behavior.
1204 set trace-buffer-size
1205 show trace-buffer-size
1206 Request target to change the size of trace buffer.
1208 set remote trace-buffer-size-packet auto|on|off
1209 show remote trace-buffer-size-packet
1210 Control the use of the remote protocol `QTBuffer:size' packet.
1214 Control display of debugging messages related to ARM AArch64.
1217 set debug coff-pe-read
1218 show debug coff-pe-read
1219 Control display of debugging messages related to reading of COFF/PE
1224 Control display of debugging messages related to Mach-O symbols
1227 set debug notification
1228 show debug notification
1229 Control display of debugging info for async remote notification.
1233 ** Command parameter changes are now notified using new async record
1234 "=cmd-param-changed".
1235 ** Trace frame changes caused by command "tfind" are now notified using
1236 new async record "=traceframe-changed".
1237 ** The creation, deletion and modification of trace state variables
1238 are now notified using new async records "=tsv-created",
1239 "=tsv-deleted" and "=tsv-modified".
1240 ** The start and stop of process record are now notified using new
1241 async record "=record-started" and "=record-stopped".
1242 ** Memory changes are now notified using new async record
1244 ** The data-disassemble command response will include a "fullname" field
1245 containing the absolute file name when source has been requested.
1246 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1247 command, to allow pattern filling of memory areas.
1248 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1249 library load/unload events.
1250 ** The response to breakpoint commands and breakpoint async records
1251 includes an "installed" field containing a boolean state about each
1252 non-pending tracepoint location is whether installed on target or not.
1253 ** Output of the "-trace-status" command includes a "trace-file" field
1254 containing the name of the trace file being examined. This field is
1255 optional, and only present when examining a trace file.
1256 ** The "fullname" field is now always present along with the "file" field,
1257 even if the file cannot be found by GDB.
1259 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1260 You must have the LZMA library available when configuring GDB for this
1261 feature to be enabled. For more information, see:
1262 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1264 * New remote packets
1267 Set the size of trace buffer. The remote stub reports support for this
1268 packet to gdb's qSupported query.
1271 Enable Branch Trace Store (BTS)-based branch tracing for the current
1272 thread. The remote stub reports support for this packet to gdb's
1276 Disable branch tracing for the current thread. The remote stub reports
1277 support for this packet to gdb's qSupported query.
1280 Read the traced branches for the current thread. The remote stub
1281 reports support for this packet to gdb's qSupported query.
1283 *** Changes in GDB 7.5
1285 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1286 for more x32 ABI info.
1288 * GDB now supports access to MIPS DSP registers on Linux targets.
1290 * GDB now supports debugging microMIPS binaries.
1292 * The "info os" command on GNU/Linux can now display information on
1293 several new classes of objects managed by the operating system:
1294 "info os procgroups" lists process groups
1295 "info os files" lists file descriptors
1296 "info os sockets" lists internet-domain sockets
1297 "info os shm" lists shared-memory regions
1298 "info os semaphores" lists semaphores
1299 "info os msg" lists message queues
1300 "info os modules" lists loaded kernel modules
1302 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1303 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1304 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1305 options and inspect the probe arguments using the new $_probe_arg family
1306 of convenience variables. You can obtain more information about SystemTap
1307 in <http://sourceware.org/systemtap/>.
1309 * GDB now supports reversible debugging on ARM, it allows you to
1310 debug basic ARM and THUMB instructions, and provides
1311 record/replay support.
1313 * The option "symbol-reloading" has been deleted as it is no longer used.
1317 ** GDB commands implemented in Python can now be put in command class
1320 ** The "maint set python print-stack on|off" is now deleted.
1322 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1323 apply "flag enum"-style pretty-printing to any enum.
1325 ** gdb.lookup_symbol can now work when there is no current frame.
1327 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1328 the source at which the symbol was defined.
1330 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1331 method 'value'. The former indicates whether the symbol needs a
1332 frame in order to compute its value, and the latter computes the
1335 ** A new method 'referenced_value' on gdb.Value objects which can
1336 dereference pointer as well as C++ reference values.
1338 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1339 which return the global and static blocks (as gdb.Block objects),
1340 of the underlying symbol table, respectively.
1342 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1343 object associated with a PC value.
1345 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1346 of the address range occupied by code for the current source line.
1348 * Go language support.
1349 GDB now supports debugging programs written in the Go programming
1352 * GDBserver now supports stdio connections.
1353 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1355 * The binary "gdbtui" can no longer be built or installed.
1356 Use "gdb -tui" instead.
1358 * GDB will now print "flag" enums specially. A flag enum is one where
1359 all the enumerator values have no bits in common when pairwise
1360 "and"ed. When printing a value whose type is a flag enum, GDB will
1361 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1362 (gdb) print (enum E) 3
1365 * The filename part of a linespec will now match trailing components
1366 of a source file name. For example, "break gcc/expr.c:1000" will
1367 now set a breakpoint in build/gcc/expr.c, but not
1368 build/libcpp/expr.c.
1370 * The "info proc" and "generate-core-file" commands will now also
1371 work on remote targets connected to GDBserver on Linux.
1373 * The command "info catch" has been removed. It has been disabled
1374 since December 2007.
1376 * The "catch exception" and "catch assert" commands now accept
1377 a condition at the end of the command, much like the "break"
1378 command does. For instance:
1380 (gdb) catch exception Constraint_Error if Barrier = True
1382 Previously, it was possible to add a condition to such catchpoints,
1383 but it had to be done as a second step, after the catchpoint had been
1384 created, using the "condition" command.
1386 * The "info static-tracepoint-marker" command will now also work on
1387 native Linux targets with in-process agent.
1389 * GDB can now set breakpoints on inlined functions.
1391 * The .gdb_index section has been updated to include symbols for
1392 inlined functions. GDB will ignore older .gdb_index sections by
1393 default, which could cause symbol files to be loaded more slowly
1394 until their .gdb_index sections can be recreated. The new command
1395 "set use-deprecated-index-sections on" will cause GDB to use any older
1396 .gdb_index sections it finds. This will restore performance, but the
1397 ability to set breakpoints on inlined functions will be lost in symbol
1398 files with older .gdb_index sections.
1400 The .gdb_index section has also been updated to record more information
1401 about each symbol. This speeds up the "info variables", "info functions"
1402 and "info types" commands when used with programs having the .gdb_index
1403 section, as well as speeding up debugging with shared libraries using
1404 the .gdb_index section.
1406 * Ada support for GDB/MI Variable Objects has been added.
1408 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1413 ** New command -info-os is the MI equivalent of "info os".
1415 ** Output logs ("set logging" and related) now include MI output.
1419 ** "set use-deprecated-index-sections on|off"
1420 "show use-deprecated-index-sections on|off"
1421 Controls the use of deprecated .gdb_index sections.
1423 ** "catch load" and "catch unload" can be used to stop when a shared
1424 library is loaded or unloaded, respectively.
1426 ** "enable count" can be used to auto-disable a breakpoint after
1429 ** "info vtbl" can be used to show the virtual method tables for
1430 C++ and Java objects.
1432 ** "explore" and its sub commands "explore value" and "explore type"
1433 can be used to recursively explore values and types of
1434 expressions. These commands are available only if GDB is
1435 configured with '--with-python'.
1437 ** "info auto-load" shows status of all kinds of auto-loaded files,
1438 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1439 sequences of commands files, "info auto-load python-scripts"
1440 shows status of auto-loading Python script files,
1441 "info auto-load local-gdbinit" shows status of loading init file
1442 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1443 status of inferior specific thread debugging shared library loading.
1445 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1446 and "show auto-load-scripts" commands have been deprecated, use their
1447 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1448 and "show auto-load python-scripts" counterparts instead.
1450 ** "dprintf location,format,args..." creates a dynamic printf, which
1451 is basically a breakpoint that does a printf and immediately
1452 resumes your program's execution, so it is like a printf that you
1453 can insert dynamically at runtime instead of at compiletime.
1455 ** "set print symbol"
1457 Controls whether GDB attempts to display the symbol, if any,
1458 corresponding to addresses it prints. This defaults to "on", but
1459 you can set it to "off" to restore GDB's previous behavior.
1461 * Deprecated commands
1463 ** For the Renesas Super-H architecture, the "regs" command has been
1464 deprecated, and "info all-registers" should be used instead.
1468 Renesas RL78 rl78-*-elf
1469 HP OpenVMS ia64 ia64-hp-openvms*
1471 * GDBserver supports evaluation of breakpoint conditions. When
1472 support is advertised by GDBserver, GDB may be told to send the
1473 breakpoint conditions in bytecode form to GDBserver. GDBserver
1474 will only report the breakpoint trigger to GDB when its condition
1479 set mips compression
1480 show mips compression
1481 Select the compressed ISA encoding used in functions that have no symbol
1482 information available. The encoding can be set to either of:
1485 and is updated automatically from ELF file flags if available.
1487 set breakpoint condition-evaluation
1488 show breakpoint condition-evaluation
1489 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1490 GDBserver ("target"). Default option "auto" chooses the most efficient
1492 This option can improve debugger efficiency depending on the speed of the
1496 Disable auto-loading globally.
1499 Show auto-loading setting of all kinds of auto-loaded files.
1501 set auto-load gdb-scripts on|off
1502 show auto-load gdb-scripts
1503 Control auto-loading of GDB canned sequences of commands files.
1505 set auto-load python-scripts on|off
1506 show auto-load python-scripts
1507 Control auto-loading of Python script files.
1509 set auto-load local-gdbinit on|off
1510 show auto-load local-gdbinit
1511 Control loading of init file (.gdbinit) from current directory.
1513 set auto-load libthread-db on|off
1514 show auto-load libthread-db
1515 Control auto-loading of inferior specific thread debugging shared library.
1517 set auto-load scripts-directory <dir1>[:<dir2>...]
1518 show auto-load scripts-directory
1519 Set a list of directories from which to load auto-loaded scripts.
1520 Automatically loaded Python scripts and GDB scripts are located in one
1521 of the directories listed by this option.
1522 The delimiter (':' above) may differ according to the host platform.
1524 set auto-load safe-path <dir1>[:<dir2>...]
1525 show auto-load safe-path
1526 Set a list of directories from which it is safe to auto-load files.
1527 The delimiter (':' above) may differ according to the host platform.
1529 set debug auto-load on|off
1530 show debug auto-load
1531 Control display of debugging info for auto-loading the files above.
1533 set dprintf-style gdb|call|agent
1535 Control the way in which a dynamic printf is performed; "gdb"
1536 requests a GDB printf command, while "call" causes dprintf to call a
1537 function in the inferior. "agent" requests that the target agent
1538 (such as GDBserver) do the printing.
1540 set dprintf-function <expr>
1541 show dprintf-function
1542 set dprintf-channel <expr>
1543 show dprintf-channel
1544 Set the function and optional first argument to the call when using
1545 the "call" style of dynamic printf.
1547 set disconnected-dprintf on|off
1548 show disconnected-dprintf
1549 Control whether agent-style dynamic printfs continue to be in effect
1550 after GDB disconnects.
1552 * New configure options
1554 --with-auto-load-dir
1555 Configure default value for the 'set auto-load scripts-directory'
1556 setting above. It defaults to '$debugdir:$datadir/auto-load',
1557 $debugdir representing global debugging info directories (available
1558 via 'show debug-file-directory') and $datadir representing GDB's data
1559 directory (available via 'show data-directory').
1561 --with-auto-load-safe-path
1562 Configure default value for the 'set auto-load safe-path' setting
1563 above. It defaults to the --with-auto-load-dir setting.
1565 --without-auto-load-safe-path
1566 Set 'set auto-load safe-path' to '/', effectively disabling this
1569 * New remote packets
1571 z0/z1 conditional breakpoints extension
1573 The z0/z1 breakpoint insertion packets have been extended to carry
1574 a list of conditional expressions over to the remote stub depending on the
1575 condition evaluation mode. The use of this extension can be controlled
1576 via the "set remote conditional-breakpoints-packet" command.
1580 Specify the signals which the remote stub may pass to the debugged
1581 program without GDB involvement.
1583 * New command line options
1585 --init-command=FILE, -ix Like --command, -x but execute it
1586 before loading inferior.
1587 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1588 execute it before loading inferior.
1590 *** Changes in GDB 7.4
1592 * GDB now handles ambiguous linespecs more consistently; the existing
1593 FILE:LINE support has been expanded to other types of linespecs. A
1594 breakpoint will now be set on all matching locations in all
1595 inferiors, and locations will be added or removed according to
1598 * GDB now allows you to skip uninteresting functions and files when
1599 stepping with the "skip function" and "skip file" commands.
1601 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1602 and "show remote hardware-watchpoint-length-limit". These allows to
1603 set or show the maximum length limit (in bytes) of a remote
1604 target hardware watchpoint.
1606 This allows e.g. to use "unlimited" hardware watchpoints with the
1607 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1608 watchpoints are slower than real hardware watchpoints but are
1609 significantly faster than gdb software watchpoints.
1613 ** The register_pretty_printer function in module gdb.printing now takes
1614 an optional `replace' argument. If True, the new printer replaces any
1617 ** The "maint set python print-stack on|off" command has been
1618 deprecated and will be deleted in GDB 7.5.
1619 A new command: "set python print-stack none|full|message" has
1620 replaced it. Additionally, the default for "print-stack" is
1621 now "message", which just prints the error message without
1624 ** A prompt substitution hook (prompt_hook) is now available to the
1627 ** A new Python module, gdb.prompt has been added to the GDB Python
1628 modules library. This module provides functionality for
1629 escape sequences in prompts (used by set/show
1630 extended-prompt). These escape sequences are replaced by their
1631 corresponding value.
1633 ** Python commands and convenience-functions located in
1634 'data-directory'/python/gdb/command and
1635 'data-directory'/python/gdb/function are now automatically loaded
1638 ** Blocks now provide four new attributes. global_block and
1639 static_block will return the global and static blocks
1640 respectively. is_static and is_global are boolean attributes
1641 that indicate if the block is one of those two types.
1643 ** Symbols now provide the "type" attribute, the type of the symbol.
1645 ** The "gdb.breakpoint" function has been deprecated in favor of
1648 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1649 of a function. This class is based on the "finish" command
1650 available in the CLI.
1652 ** Type objects for struct and union types now allow access to
1653 the fields using standard Python dictionary (mapping) methods.
1654 For example, "some_type['myfield']" now works, as does
1655 "some_type.items()".
1657 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1660 ** A new function, "deep_items" has been added to the gdb.types
1661 module in the GDB Python modules library. This function returns
1662 an iterator over the fields of a struct or union type. Unlike
1663 the standard Python "iteritems" method, it will recursively traverse
1664 any anonymous fields.
1668 ** "*stopped" events can report several new "reason"s, such as
1671 ** Breakpoint changes are now notified using new async records, like
1672 "=breakpoint-modified".
1674 ** New command -ada-task-info.
1676 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1677 $sdir specifies the default system locations of shared libraries.
1678 $pdir specifies the directory where the libpthread used by the application
1681 GDB no longer looks in $sdir and $pdir after it has searched the directories
1682 mentioned in libthread-db-search-path. If you want to search those
1683 directories, they must be specified in libthread-db-search-path.
1684 The default value of libthread-db-search-path on GNU/Linux and Solaris
1685 systems is now "$sdir:$pdir".
1687 $pdir is not supported by gdbserver, it is currently ignored.
1688 $sdir is supported by gdbserver.
1690 * New configure option --with-iconv-bin.
1691 When using the internationalization support like the one in the GNU C
1692 library, GDB will invoke the "iconv" program to get a list of supported
1693 character sets. If this program lives in a non-standard location, one can
1694 use this option to specify where to find it.
1696 * When natively debugging programs on PowerPC BookE processors running
1697 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1698 watchpoints, which specify a mask in addition to an address to watch.
1699 The mask specifies that some bits of an address (the bits which are
1700 reset in the mask) should be ignored when matching the address accessed
1701 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1702 section in the user manual for more details.
1704 * The new option --once causes GDBserver to stop listening for connections once
1705 the first connection is made. The listening port used by GDBserver will
1706 become available after that.
1708 * New commands "info macros" and "alias" have been added.
1710 * New function parameters suffix @entry specifies value of function parameter
1711 at the time the function got called. Entry values are available only since
1717 "!" is now an alias of the "shell" command.
1718 Note that no space is needed between "!" and SHELL COMMAND.
1722 watch EXPRESSION mask MASK_VALUE
1723 The watch command now supports the mask argument which allows creation
1724 of masked watchpoints, if the current architecture supports this feature.
1726 info auto-load-scripts [REGEXP]
1727 This command was formerly named "maintenance print section-scripts".
1728 It is now generally useful and is no longer a maintenance-only command.
1730 info macro [-all] [--] MACRO
1731 The info macro command has new options `-all' and `--'. The first for
1732 printing all definitions of a macro. The second for explicitly specifying
1733 the end of arguments and the beginning of the macro name in case the macro
1734 name starts with a hyphen.
1736 collect[/s] EXPRESSIONS
1737 The tracepoint collect command now takes an optional modifier "/s"
1738 that directs it to dereference pointer-to-character types and
1739 collect the bytes of memory up to a zero byte. The behavior is
1740 similar to what you see when you use the regular print command on a
1741 string. An optional integer following the "/s" sets a bound on the
1742 number of bytes that will be collected.
1745 The trace start command now interprets any supplied arguments as a
1746 note to be recorded with the trace run, with an effect similar to
1747 setting the variable trace-notes.
1750 The trace stop command now interprets any arguments as a note to be
1751 mentioned along with the tstatus report that the trace was stopped
1752 with a command. The effect is similar to setting the variable
1755 * Tracepoints can now be enabled and disabled at any time after a trace
1756 experiment has been started using the standard "enable" and "disable"
1757 commands. It is now possible to start a trace experiment with no enabled
1758 tracepoints; GDB will display a warning, but will allow the experiment to
1759 begin, assuming that tracepoints will be enabled as needed while the trace
1762 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1763 locations with 4-byte instructions, when they were previously
1764 limited to locations with instructions of 5 bytes or longer.
1768 set debug dwarf2-read
1769 show debug dwarf2-read
1770 Turns on or off display of debugging messages related to reading
1771 DWARF debug info. The default is off.
1773 set debug symtab-create
1774 show debug symtab-create
1775 Turns on or off display of debugging messages related to symbol table
1776 creation. The default is off.
1779 show extended-prompt
1780 Set the GDB prompt, and allow escape sequences to be inserted to
1781 display miscellaneous information (see 'help set extended-prompt'
1782 for the list of sequences). This prompt (and any information
1783 accessed through the escape sequences) is updated every time the
1784 prompt is displayed.
1786 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1787 show print entry-values
1788 Set printing of frame argument values at function entry. In some cases
1789 GDB can determine the value of function argument which was passed by the
1790 function caller, even if the value was modified inside the called function.
1792 set debug entry-values
1793 show debug entry-values
1794 Control display of debugging info for determining frame argument values at
1795 function entry and virtual tail call frames.
1797 set basenames-may-differ
1798 show basenames-may-differ
1799 Set whether a source file may have multiple base names.
1800 (A "base name" is the name of a file with the directory part removed.
1801 Example: The base name of "/home/user/hello.c" is "hello.c".)
1802 If set, GDB will canonicalize file names (e.g., expand symlinks)
1803 before comparing them. Canonicalization is an expensive operation,
1804 but it allows the same file be known by more than one base name.
1805 If not set (the default), all source files are assumed to have just
1806 one base name, and gdb will do file name comparisons more efficiently.
1812 Set a user name and notes for the current and any future trace runs.
1813 This is useful for long-running and/or disconnected traces, to
1814 inform others (or yourself) as to who is running the trace, supply
1815 contact information, or otherwise explain what is going on.
1817 set trace-stop-notes
1818 show trace-stop-notes
1819 Set a note attached to the trace run, that is displayed when the
1820 trace has been stopped by a tstop command. This is useful for
1821 instance as an explanation, if you are stopping a trace run that was
1822 started by someone else.
1824 * New remote packets
1828 Dynamically enable a tracepoint in a started trace experiment.
1832 Dynamically disable a tracepoint in a started trace experiment.
1836 Set the user and notes of the trace run.
1840 Query the current status of a tracepoint.
1844 Query the minimum length of instruction at which a fast tracepoint may
1847 * Dcache size (number of lines) and line-size are now runtime-configurable
1848 via "set dcache line" and "set dcache line-size" commands.
1852 Texas Instruments TMS320C6x tic6x-*-*
1856 Renesas RL78 rl78-*-elf
1858 *** Changes in GDB 7.3.1
1860 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1862 *** Changes in GDB 7.3
1864 * GDB has a new command: "thread find [REGEXP]".
1865 It finds the thread id whose name, target id, or thread extra info
1866 matches the given regular expression.
1868 * The "catch syscall" command now works on mips*-linux* targets.
1870 * The -data-disassemble MI command now supports modes 2 and 3 for
1871 dumping the instruction opcodes.
1873 * New command line options
1875 -data-directory DIR Specify DIR as the "data-directory".
1876 This is mostly for testing purposes.
1878 * The "maint set python auto-load on|off" command has been renamed to
1879 "set auto-load-scripts on|off".
1881 * GDB has a new command: "set directories".
1882 It is like the "dir" command except that it replaces the
1883 source path list instead of augmenting it.
1885 * GDB now understands thread names.
1887 On GNU/Linux, "info threads" will display the thread name as set by
1888 prctl or pthread_setname_np.
1890 There is also a new command, "thread name", which can be used to
1891 assign a name internally for GDB to display.
1894 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1895 has been integrated into GDB.
1899 ** The function gdb.Write now accepts an optional keyword 'stream'.
1900 This keyword, when provided, will direct the output to either
1901 stdout, stderr, or GDB's logging output.
1903 ** Parameters can now be be sub-classed in Python, and in particular
1904 you may implement the get_set_doc and get_show_doc functions.
1905 This improves how Parameter set/show documentation is processed
1906 and allows for more dynamic content.
1908 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1909 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1910 have an is_valid method.
1912 ** Breakpoints can now be sub-classed in Python, and in particular
1913 you may implement a 'stop' function that is executed each time
1914 the inferior reaches that breakpoint.
1916 ** New function gdb.lookup_global_symbol looks up a global symbol.
1918 ** GDB values in Python are now callable if the value represents a
1919 function. For example, if 'some_value' represents a function that
1920 takes two integer parameters and returns a value, you can call
1921 that function like so:
1923 result = some_value (10,20)
1925 ** Module gdb.types has been added.
1926 It contains a collection of utilities for working with gdb.Types objects:
1927 get_basic_type, has_field, make_enum_dict.
1929 ** Module gdb.printing has been added.
1930 It contains utilities for writing and registering pretty-printers.
1931 New classes: PrettyPrinter, SubPrettyPrinter,
1932 RegexpCollectionPrettyPrinter.
1933 New function: register_pretty_printer.
1935 ** New commands "info pretty-printers", "enable pretty-printer" and
1936 "disable pretty-printer" have been added.
1938 ** gdb.parameter("directories") is now available.
1940 ** New function gdb.newest_frame returns the newest frame in the
1943 ** The gdb.InferiorThread class has a new "name" attribute. This
1944 holds the thread's name.
1946 ** Python Support for Inferior events.
1947 Python scripts can add observers to be notified of events
1948 occurring in the process being debugged.
1949 The following events are currently supported:
1950 - gdb.events.cont Continue event.
1951 - gdb.events.exited Inferior exited event.
1952 - gdb.events.stop Signal received, and Breakpoint hit events.
1956 ** GDB now puts template parameters in scope when debugging in an
1957 instantiation. For example, if you have:
1959 template<int X> int func (void) { return X; }
1961 then if you step into func<5>, "print X" will show "5". This
1962 feature requires proper debuginfo support from the compiler; it
1963 was added to GCC 4.5.
1965 ** The motion commands "next", "finish", "until", and "advance" now
1966 work better when exceptions are thrown. In particular, GDB will
1967 no longer lose control of the inferior; instead, the GDB will
1968 stop the inferior at the point at which the exception is caught.
1969 This functionality requires a change in the exception handling
1970 code that was introduced in GCC 4.5.
1972 * GDB now follows GCC's rules on accessing volatile objects when
1973 reading or writing target state during expression evaluation.
1974 One notable difference to prior behavior is that "print x = 0"
1975 no longer generates a read of x; the value of the assignment is
1976 now always taken directly from the value being assigned.
1978 * GDB now has some support for using labels in the program's source in
1979 linespecs. For instance, you can use "advance label" to continue
1980 execution to a label.
1982 * GDB now has support for reading and writing a new .gdb_index
1983 section. This section holds a fast index of DWARF debugging
1984 information and can be used to greatly speed up GDB startup and
1985 operation. See the documentation for `save gdb-index' for details.
1987 * The "watch" command now accepts an optional "-location" argument.
1988 When used, this causes GDB to watch the memory referred to by the
1989 expression. Such a watchpoint is never deleted due to it going out
1992 * GDB now supports thread debugging of core dumps on GNU/Linux.
1994 GDB now activates thread debugging using the libthread_db library
1995 when debugging GNU/Linux core dumps, similarly to when debugging
1996 live processes. As a result, when debugging a core dump file, GDB
1997 is now able to display pthread_t ids of threads. For example, "info
1998 threads" shows the same output as when debugging the process when it
1999 was live. In earlier releases, you'd see something like this:
2002 * 1 LWP 6780 main () at main.c:10
2004 While now you see this:
2007 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2009 It is also now possible to inspect TLS variables when debugging core
2012 When debugging a core dump generated on a machine other than the one
2013 used to run GDB, you may need to point GDB at the correct
2014 libthread_db library with the "set libthread-db-search-path"
2015 command. See the user manual for more details on this command.
2017 * When natively debugging programs on PowerPC BookE processors running
2018 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2019 which stop execution of the inferior whenever it executes an instruction
2020 at any address within the specified range. See the "PowerPC Embedded"
2021 section in the user manual for more details.
2023 * New features in the GDB remote stub, GDBserver
2025 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2026 and i686 LynxOS (version 5.x).
2028 ** GDBserver is now supported on Blackfin Linux.
2030 * New native configurations
2032 ia64 HP-UX ia64-*-hpux*
2036 Analog Devices, Inc. Blackfin Processor bfin-*
2038 * Ada task switching is now supported on sparc-elf targets when
2039 debugging a program using the Ravenscar Profile. For more information,
2040 see the "Tasking Support when using the Ravenscar Profile" section
2041 in the GDB user manual.
2043 * Guile support was removed.
2045 * New features in the GNU simulator
2047 ** The --map-info flag lists all known core mappings.
2049 ** CFI flashes may be simulated via the "cfi" device.
2051 *** Changes in GDB 7.2
2053 * Shared library support for remote targets by default
2055 When GDB is configured for a generic, non-OS specific target, like
2056 for example, --target=arm-eabi or one of the many *-*-elf targets,
2057 GDB now queries remote stubs for loaded shared libraries using the
2058 `qXfer:libraries:read' packet. Previously, shared library support
2059 was always disabled for such configurations.
2063 ** Argument Dependent Lookup (ADL)
2065 In C++ ADL lookup directs function search to the namespaces of its
2066 arguments even if the namespace has not been imported.
2076 Here the compiler will search for `foo' in the namespace of 'b'
2077 and find A::foo. GDB now supports this. This construct is commonly
2078 used in the Standard Template Library for operators.
2080 ** Improved User Defined Operator Support
2082 In addition to member operators, GDB now supports lookup of operators
2083 defined in a namespace and imported with a `using' directive, operators
2084 defined in the global scope, operators imported implicitly from an
2085 anonymous namespace, and the ADL operators mentioned in the previous
2087 GDB now also supports proper overload resolution for all the previously
2088 mentioned flavors of operators.
2090 ** static const class members
2092 Printing of static const class members that are initialized in the
2093 class definition has been fixed.
2095 * Windows Thread Information Block access.
2097 On Windows targets, GDB now supports displaying the Windows Thread
2098 Information Block (TIB) structure. This structure is visible either
2099 by using the new command `info w32 thread-information-block' or, by
2100 dereferencing the new convenience variable named `$_tlb', a
2101 thread-specific pointer to the TIB. This feature is also supported
2102 when remote debugging using GDBserver.
2104 * Static tracepoints
2106 Static tracepoints are calls in the user program into a tracing
2107 library. One such library is a port of the LTTng kernel tracer to
2108 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2109 When debugging with GDBserver, GDB now supports combining the GDB
2110 tracepoint machinery with such libraries. For example: the user can
2111 use GDB to probe a static tracepoint marker (a call from the user
2112 program into the tracing library) with the new "strace" command (see
2113 "New commands" below). This creates a "static tracepoint" in the
2114 breakpoint list, that can be manipulated with the same feature set
2115 as fast and regular tracepoints. E.g., collect registers, local and
2116 global variables, collect trace state variables, and define
2117 tracepoint conditions. In addition, the user can collect extra
2118 static tracepoint marker specific data, by collecting the new
2119 $_sdata internal variable. When analyzing the trace buffer, you can
2120 inspect $_sdata like any other variable available to GDB. For more
2121 information, see the "Tracepoints" chapter in GDB user manual. New
2122 remote packets have been defined to support static tracepoints, see
2123 the "New remote packets" section below.
2125 * Better reconstruction of tracepoints after disconnected tracing
2127 GDB will attempt to download the original source form of tracepoint
2128 definitions when starting a trace run, and then will upload these
2129 upon reconnection to the target, resulting in a more accurate
2130 reconstruction of the tracepoints that are in use on the target.
2134 You can now exercise direct control over the ways that GDB can
2135 affect your program. For instance, you can disallow the setting of
2136 breakpoints, so that the program can run continuously (assuming
2137 non-stop mode). In addition, the "observer" variable is available
2138 to switch all of the different controls; in observer mode, GDB
2139 cannot affect the target's behavior at all, which is useful for
2140 tasks like diagnosing live systems in the field.
2142 * The new convenience variable $_thread holds the number of the
2145 * New remote packets
2149 Return the address of the Windows Thread Information Block of a given thread.
2153 In response to several of the tracepoint packets, the target may now
2154 also respond with a number of intermediate `qRelocInsn' request
2155 packets before the final result packet, to have GDB handle
2156 relocating an instruction to execute at a different address. This
2157 is particularly useful for stubs that support fast tracepoints. GDB
2158 reports support for this feature in the qSupported packet.
2162 List static tracepoint markers in the target program.
2166 List static tracepoint markers at a given address in the target
2169 qXfer:statictrace:read
2171 Read the static trace data collected (by a `collect $_sdata'
2172 tracepoint action). The remote stub reports support for this packet
2173 to gdb's qSupported query.
2177 Send the current settings of GDB's permission flags.
2181 Send part of the source (textual) form of a tracepoint definition,
2182 which includes location, conditional, and action list.
2184 * The source command now accepts a -s option to force searching for the
2185 script in the source search path even if the script name specifies
2188 * New features in the GDB remote stub, GDBserver
2190 - GDBserver now support tracepoints (including fast tracepoints, and
2191 static tracepoints). The feature is currently supported by the
2192 i386-linux and amd64-linux builds. See the "Tracepoints support
2193 in gdbserver" section in the manual for more information.
2195 GDBserver JIT compiles the tracepoint's conditional agent
2196 expression bytecode into native code whenever possible for low
2197 overhead dynamic tracepoints conditionals. For such tracepoints,
2198 an expression that examines program state is evaluated when the
2199 tracepoint is reached, in order to determine whether to capture
2200 trace data. If the condition is simple and false, processing the
2201 tracepoint finishes very quickly and no data is gathered.
2203 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2204 for static tracepoints support.
2206 - GDBserver now supports x86_64 Windows 64-bit debugging.
2208 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2209 it understands register description.
2211 * The --batch flag now disables pagination and queries.
2213 * X86 general purpose registers
2215 GDB now supports reading/writing byte, word and double-word x86
2216 general purpose registers directly. This means you can use, say,
2217 $ah or $ax to refer, respectively, to the byte register AH and
2218 16-bit word register AX that are actually portions of the 32-bit
2219 register EAX or 64-bit register RAX.
2221 * The `commands' command now accepts a range of breakpoints to modify.
2222 A plain `commands' following a command that creates multiple
2223 breakpoints affects all the breakpoints set by that command. This
2224 applies to breakpoints set by `rbreak', and also applies when a
2225 single `break' command creates multiple breakpoints (e.g.,
2226 breakpoints on overloaded c++ functions).
2228 * The `rbreak' command now accepts a filename specification as part of
2229 its argument, limiting the functions selected by the regex to those
2230 in the specified file.
2232 * Support for remote debugging Windows and SymbianOS shared libraries
2233 from Unix hosts has been improved. Non Windows GDB builds now can
2234 understand target reported file names that follow MS-DOS based file
2235 system semantics, such as file names that include drive letters and
2236 use the backslash character as directory separator. This makes it
2237 possible to transparently use the "set sysroot" and "set
2238 solib-search-path" on Unix hosts to point as host copies of the
2239 target's shared libraries. See the new command "set
2240 target-file-system-kind" described below, and the "Commands to
2241 specify files" section in the user manual for more information.
2245 eval template, expressions...
2246 Convert the values of one or more expressions under the control
2247 of the string template to a command line, and call it.
2249 set target-file-system-kind unix|dos-based|auto
2250 show target-file-system-kind
2251 Set or show the assumed file system kind for target reported file
2254 save breakpoints <filename>
2255 Save all current breakpoint definitions to a file suitable for use
2256 in a later debugging session. To read the saved breakpoint
2257 definitions, use the `source' command.
2259 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2262 info static-tracepoint-markers
2263 Display information about static tracepoint markers in the target.
2265 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2266 Define a static tracepoint by probing a marker at the given
2267 function, line, address, or marker ID.
2271 Enable and disable observer mode.
2273 set may-write-registers on|off
2274 set may-write-memory on|off
2275 set may-insert-breakpoints on|off
2276 set may-insert-tracepoints on|off
2277 set may-insert-fast-tracepoints on|off
2278 set may-interrupt on|off
2279 Set individual permissions for GDB effects on the target. Note that
2280 some of these settings can have undesirable or surprising
2281 consequences, particularly when changed in the middle of a session.
2282 For instance, disabling the writing of memory can prevent
2283 breakpoints from being inserted, cause single-stepping to fail, or
2284 even crash your program, if you disable after breakpoints have been
2285 inserted. However, GDB should not crash.
2287 set record memory-query on|off
2288 show record memory-query
2289 Control whether to stop the inferior if memory changes caused
2290 by an instruction cannot be recorded.
2295 The disassemble command now supports "start,+length" form of two arguments.
2299 ** GDB now provides a new directory location, called the python directory,
2300 where Python scripts written for GDB can be installed. The location
2301 of that directory is <data-directory>/python, where <data-directory>
2302 is the GDB data directory. For more details, see section `Scripting
2303 GDB using Python' in the manual.
2305 ** The GDB Python API now has access to breakpoints, symbols, symbol
2306 tables, program spaces, inferiors, threads and frame's code blocks.
2307 Additionally, GDB Parameters can now be created from the API, and
2308 manipulated via set/show in the CLI.
2310 ** New functions gdb.target_charset, gdb.target_wide_charset,
2311 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2313 ** New exception gdb.GdbError.
2315 ** Pretty-printers are now also looked up in the current program space.
2317 ** Pretty-printers can now be individually enabled and disabled.
2319 ** GDB now looks for names of Python scripts to auto-load in a
2320 special section named `.debug_gdb_scripts', in addition to looking
2321 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2323 * Tracepoint actions were unified with breakpoint commands. In particular,
2324 there are no longer differences in "info break" output for breakpoints and
2325 tracepoints and the "commands" command can be used for both tracepoints and
2326 regular breakpoints.
2330 ARM Symbian arm*-*-symbianelf*
2332 * D language support.
2333 GDB now supports debugging programs written in the D programming
2336 * GDB now supports the extended ptrace interface for PowerPC which is
2337 available since Linux kernel version 2.6.34. This automatically enables
2338 any hardware breakpoints and additional hardware watchpoints available in
2339 the processor. The old ptrace interface exposes just one hardware
2340 watchpoint and no hardware breakpoints.
2342 * GDB is now able to use the Data Value Compare (DVC) register available on
2343 embedded PowerPC processors to implement in hardware simple watchpoint
2344 conditions of the form:
2346 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2348 This works in native GDB running on Linux kernels with the extended ptrace
2349 interface mentioned above.
2351 *** Changes in GDB 7.1
2355 ** Namespace Support
2357 GDB now supports importing of namespaces in C++. This enables the
2358 user to inspect variables from imported namespaces. Support for
2359 namepace aliasing has also been added. So, if a namespace is
2360 aliased in the current scope (e.g. namepace C=A; ) the user can
2361 print variables using the alias (e.g. (gdb) print C::x).
2365 All known bugs relating to the printing of virtual base class were
2366 fixed. It is now possible to call overloaded static methods using a
2371 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2372 and reinterpret_cast<> are now handled by the C++ expression parser.
2376 Xilinx MicroBlaze microblaze-*-*
2381 Xilinx MicroBlaze microblaze
2384 * Multi-program debugging.
2386 GDB now has support for multi-program (a.k.a. multi-executable or
2387 multi-exec) debugging. This allows for debugging multiple inferiors
2388 simultaneously each running a different program under the same GDB
2389 session. See "Debugging Multiple Inferiors and Programs" in the
2390 manual for more information. This implied some user visible changes
2391 in the multi-inferior support. For example, "info inferiors" now
2392 lists inferiors that are not running yet or that have exited
2393 already. See also "New commands" and "New options" below.
2395 * New tracing features
2397 GDB's tracepoint facility now includes several new features:
2399 ** Trace state variables
2401 GDB tracepoints now include support for trace state variables, which
2402 are variables managed by the target agent during a tracing
2403 experiment. They are useful for tracepoints that trigger each
2404 other, so for instance one tracepoint can count hits in a variable,
2405 and then a second tracepoint has a condition that is true when the
2406 count reaches a particular value. Trace state variables share the
2407 $-syntax of GDB convenience variables, and can appear in both
2408 tracepoint actions and condition expressions. Use the "tvariable"
2409 command to create, and "info tvariables" to view; see "Trace State
2410 Variables" in the manual for more detail.
2414 GDB now includes an option for defining fast tracepoints, which
2415 targets may implement more efficiently, such as by installing a jump
2416 into the target agent rather than a trap instruction. The resulting
2417 speedup can be by two orders of magnitude or more, although the
2418 tradeoff is that some program locations on some target architectures
2419 might not allow fast tracepoint installation, for instance if the
2420 instruction to be replaced is shorter than the jump. To request a
2421 fast tracepoint, use the "ftrace" command, with syntax identical to
2422 the regular trace command.
2424 ** Disconnected tracing
2426 It is now possible to detach GDB from the target while it is running
2427 a trace experiment, then reconnect later to see how the experiment
2428 is going. In addition, a new variable disconnected-tracing lets you
2429 tell the target agent whether to continue running a trace if the
2430 connection is lost unexpectedly.
2434 GDB now has the ability to save the trace buffer into a file, and
2435 then use that file as a target, similarly to you can do with
2436 corefiles. You can select trace frames, print data that was
2437 collected in them, and use tstatus to display the state of the
2438 tracing run at the moment that it was saved. To create a trace
2439 file, use "tsave <filename>", and to use it, do "target tfile
2442 ** Circular trace buffer
2444 You can ask the target agent to handle the trace buffer as a
2445 circular buffer, discarding the oldest trace frames to make room for
2446 newer ones, by setting circular-trace-buffer to on. This feature may
2447 not be available for all target agents.
2452 The disassemble command, when invoked with two arguments, now requires
2453 the arguments to be comma-separated.
2456 The info variables command now displays variable definitions. Files
2457 which only declare a variable are not shown.
2460 The source command is now capable of sourcing Python scripts.
2461 This feature is dependent on the debugger being build with Python
2464 Related to this enhancement is also the introduction of a new command
2465 "set script-extension" (see below).
2467 * New commands (for set/show, see "New options" below)
2469 record save [<FILENAME>]
2470 Save a file (in core file format) containing the process record
2471 execution log for replay debugging at a later time.
2473 record restore <FILENAME>
2474 Restore the process record execution log that was saved at an
2475 earlier time, for replay debugging.
2477 add-inferior [-copies <N>] [-exec <FILENAME>]
2480 clone-inferior [-copies <N>] [ID]
2481 Make a new inferior ready to execute the same program another
2482 inferior has loaded.
2487 maint info program-spaces
2488 List the program spaces loaded into GDB.
2490 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2491 show remote interrupt-sequence
2492 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2493 as the sequence to the remote target in order to interrupt the execution.
2494 Ctrl-C is a default. Some system prefers BREAK which is high level of
2495 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2496 Magic SysRq g. It is BREAK signal and character 'g'.
2498 set remote interrupt-on-connect [on | off]
2499 show remote interrupt-on-connect
2500 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2501 remote target when gdb connects to it. This is needed when you debug
2504 set remotebreak [on | off]
2506 Deprecated. Use "set/show remote interrupt-sequence" instead.
2508 tvariable $NAME [ = EXP ]
2509 Create or modify a trace state variable.
2512 List trace state variables and their values.
2514 delete tvariable $NAME ...
2515 Delete one or more trace state variables.
2518 Evaluate the given expressions without collecting anything into the
2519 trace buffer. (Valid in tracepoint actions only.)
2521 ftrace FN / FILE:LINE / *ADDR
2522 Define a fast tracepoint at the given function, line, or address.
2524 * New expression syntax
2526 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2527 GDB now parses 0b101010 identically with 42.
2531 set follow-exec-mode new|same
2532 show follow-exec-mode
2533 Control whether GDB reuses the same inferior across an exec call or
2534 creates a new one. This is useful to be able to restart the old
2535 executable after the inferior having done an exec call.
2537 set default-collect EXPR, ...
2538 show default-collect
2539 Define a list of expressions to be collected at each tracepoint.
2540 This is a useful way to ensure essential items are not overlooked,
2541 such as registers or a critical global variable.
2543 set disconnected-tracing
2544 show disconnected-tracing
2545 If set to 1, the target is instructed to continue tracing if it
2546 loses its connection to GDB. If 0, the target is to stop tracing
2549 set circular-trace-buffer
2550 show circular-trace-buffer
2551 If set to on, the target is instructed to use a circular trace buffer
2552 and discard the oldest trace frames instead of stopping the trace due
2553 to a full trace buffer. If set to off, the trace stops when the buffer
2554 fills up. Some targets may not support this.
2556 set script-extension off|soft|strict
2557 show script-extension
2558 If set to "off", the debugger does not perform any script language
2559 recognition, and all sourced files are assumed to be GDB scripts.
2560 If set to "soft" (the default), files are sourced according to
2561 filename extension, falling back to GDB scripts if the first
2563 If set to "strict", files are sourced according to filename extension.
2565 set ada trust-PAD-over-XVS on|off
2566 show ada trust-PAD-over-XVS
2567 If off, activate a workaround against a bug in the debugging information
2568 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2569 the GCC sources for more information about the GNAT encoding and
2570 PAD types in particular). It is always safe to set this option to
2571 off, but this introduces a slight performance penalty. The default
2574 * Python API Improvements
2576 ** GDB provides the new class gdb.LazyString. This is useful in
2577 some pretty-printing cases. The new method gdb.Value.lazy_string
2578 provides a simple way to create objects of this type.
2580 ** The fields returned by gdb.Type.fields now have an
2581 `is_base_class' attribute.
2583 ** The new method gdb.Type.range returns the range of an array type.
2585 ** The new method gdb.parse_and_eval can be used to parse and
2586 evaluate an expression.
2588 * New remote packets
2591 Define a trace state variable.
2594 Get the current value of a trace state variable.
2597 Set desired tracing behavior upon disconnection.
2600 Set the trace buffer to be linear or circular.
2603 Get data about the tracepoints currently in use.
2607 Process record now works correctly with hardware watchpoints.
2609 Multiple bug fixes have been made to the mips-irix port, making it
2610 much more reliable. In particular:
2611 - Debugging threaded applications is now possible again. Previously,
2612 GDB would hang while starting the program, or while waiting for
2613 the program to stop at a breakpoint.
2614 - Attaching to a running process no longer hangs.
2615 - An error occurring while loading a core file has been fixed.
2616 - Changing the value of the PC register now works again. This fixes
2617 problems observed when using the "jump" command, or when calling
2618 a function from GDB, or even when assigning a new value to $pc.
2619 - With the "finish" and "return" commands, the return value for functions
2620 returning a small array is now correctly printed.
2621 - It is now possible to break on shared library code which gets executed
2622 during a shared library init phase (code executed while executing
2623 their .init section). Previously, the breakpoint would have no effect.
2624 - GDB is now able to backtrace through the signal handler for
2625 non-threaded programs.
2627 PIE (Position Independent Executable) programs debugging is now supported.
2628 This includes debugging execution of PIC (Position Independent Code) shared
2629 libraries although for that, it should be possible to run such libraries as an
2632 *** Changes in GDB 7.0
2634 * GDB now has an interface for JIT compilation. Applications that
2635 dynamically generate code can create symbol files in memory and register
2636 them with GDB. For users, the feature should work transparently, and
2637 for JIT developers, the interface is documented in the GDB manual in the
2638 "JIT Compilation Interface" chapter.
2640 * Tracepoints may now be conditional. The syntax is as for
2641 breakpoints; either an "if" clause appended to the "trace" command,
2642 or the "condition" command is available. GDB sends the condition to
2643 the target for evaluation using the same bytecode format as is used
2644 for tracepoint actions.
2646 * The disassemble command now supports: an optional /r modifier, print the
2647 raw instructions in hex as well as in symbolic form, and an optional /m
2648 modifier to print mixed source+assembly.
2650 * Process record and replay
2652 In a architecture environment that supports ``process record and
2653 replay'', ``process record and replay'' target can record a log of
2654 the process execution, and replay it with both forward and reverse
2657 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2658 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2659 set execution-direction {forward|reverse}, for targets that support
2662 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2663 feature is available with a native GDB running on kernel version
2666 * GDB now has support for multi-byte and wide character sets on the
2667 target. Strings whose character type is wchar_t, char16_t, or
2668 char32_t are now correctly printed. GDB supports wide- and unicode-
2669 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2670 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2671 `printf'. This feature requires iconv to work properly; if your
2672 system does not have a working iconv, GDB can use GNU libiconv. See
2673 the installation instructions for more information.
2675 * GDB now supports automatic retrieval of shared library files from
2676 remote targets. To use this feature, specify a system root that begins
2677 with the `remote:' prefix, either via the `set sysroot' command or via
2678 the `--with-sysroot' configure-time option.
2680 * "info sharedlibrary" now takes an optional regex of libraries to show,
2681 and it now reports if a shared library has no debugging information.
2683 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2684 now complete on file names.
2686 * When completing in expressions, gdb will attempt to limit
2687 completions to allowable structure or union fields, where appropriate.
2688 For instance, consider:
2690 # struct example { int f1; double f2; };
2691 # struct example variable;
2694 If the user types TAB at the end of this command line, the available
2695 completions will be "f1" and "f2".
2697 * Inlined functions are now supported. They show up in backtraces, and
2698 the "step", "next", and "finish" commands handle them automatically.
2700 * GDB now supports the token-splicing (##) and stringification (#)
2701 operators when expanding macros. It also supports variable-arity
2704 * GDB now supports inspecting extra signal information, exported by
2705 the new $_siginfo convenience variable. The feature is currently
2706 implemented on linux ARM, i386 and amd64.
2708 * GDB can now display the VFP floating point registers and NEON vector
2709 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2710 can provide these registers (requires Linux 2.6.30 or later). Remote
2711 and simulator targets may also provide them.
2713 * New remote packets
2716 Search memory for a sequence of bytes.
2719 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2720 operation over reliable transport links. Use of this packet is
2721 controlled by the `set remote noack-packet' command.
2724 Kill the process with the specified process ID. Use this in preference
2725 to `k' when multiprocess protocol extensions are supported.
2728 Obtains additional operating system information
2732 Read or write additional signal information.
2734 * Removed remote protocol undocumented extension
2736 An undocumented extension to the remote protocol's `S' stop reply
2737 packet that permited the stub to pass a process id was removed.
2738 Remote servers should use the `T' stop reply packet instead.
2740 * GDB now supports multiple function calling conventions according to the
2741 DWARF-2 DW_AT_calling_convention function attribute.
2743 * The SH target utilizes the aforementioned change to distinguish between gcc
2744 and Renesas calling convention. It also adds the new CLI commands
2745 `set/show sh calling-convention'.
2747 * GDB can now read compressed debug sections, as produced by GNU gold
2748 with the --compress-debug-sections=zlib flag.
2750 * 64-bit core files are now supported on AIX.
2752 * Thread switching is now supported on Tru64.
2754 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2755 which will be allocated using malloc later in program execution.
2757 * The qXfer:libraries:read remote procotol packet now allows passing a
2758 list of section offsets.
2760 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2761 conditions handling signals delivered during attach or thread creation
2762 have also been fixed.
2764 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2765 From the user's standpoint, all unqualified instances of True and False
2766 are treated as the standard definitions, regardless of context.
2768 * GDB now parses C++ symbol and type names more flexibly. For
2771 template<typename T> class C { };
2774 GDB will now correctly handle all of:
2776 ptype C<char const *>
2777 ptype C<char const*>
2778 ptype C<const char *>
2779 ptype C<const char*>
2781 * New features in the GDB remote stub, gdbserver
2783 - The "--wrapper" command-line argument tells gdbserver to use a
2784 wrapper program to launch programs for debugging.
2786 - On PowerPC and S/390 targets, it is now possible to use a single
2787 gdbserver executable to debug both 32-bit and 64-bit programs.
2788 (This requires gdbserver itself to be built as a 64-bit executable.)
2790 - gdbserver uses the new noack protocol mode for TCP connections to
2791 reduce communications latency, if also supported and enabled in GDB.
2793 - Support for the sparc64-linux-gnu target is now included in
2796 - The amd64-linux build of gdbserver now supports debugging both
2797 32-bit and 64-bit programs.
2799 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2800 now support hardware watchpoints, and will use them automatically
2805 GDB now has support for scripting using Python. Whether this is
2806 available is determined at configure time.
2808 New GDB commands can now be written in Python.
2810 * Ada tasking support
2812 Ada tasks can now be inspected in GDB. The following commands have
2816 Print the list of Ada tasks.
2818 Print detailed information about task number N.
2820 Print the task number of the current task.
2822 Switch the context of debugging to task number N.
2824 * Support for user-defined prefixed commands. The "define" command can
2825 add new commands to existing prefixes, e.g. "target".
2827 * Multi-inferior, multi-process debugging.
2829 GDB now has generalized support for multi-inferior debugging. See
2830 "Debugging Multiple Inferiors" in the manual for more information.
2831 Although availability still depends on target support, the command
2832 set is more uniform now. The GNU/Linux specific multi-forks support
2833 has been migrated to this new framework. This implied some user
2834 visible changes; see "New commands" and also "Removed commands"
2837 * Target descriptions can now describe the target OS ABI. See the
2838 "Target Description Format" section in the user manual for more
2841 * Target descriptions can now describe "compatible" architectures
2842 to indicate that the target can execute applications for a different
2843 architecture in addition to those for the main target architecture.
2844 See the "Target Description Format" section in the user manual for
2847 * Multi-architecture debugging.
2849 GDB now includes general supports for debugging applications on
2850 hybrid systems that use more than one single processor architecture
2851 at the same time. Each such hybrid architecture still requires
2852 specific support to be added. The only hybrid architecture supported
2853 in this version of GDB is the Cell Broadband Engine.
2855 * GDB now supports integrated debugging of Cell/B.E. applications that
2856 use both the PPU and SPU architectures. To enable support for hybrid
2857 Cell/B.E. debugging, you need to configure GDB to support both the
2858 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2859 --enable-targets configure option.
2861 * Non-stop mode debugging.
2863 For some targets, GDB now supports an optional mode of operation in
2864 which you can examine stopped threads while other threads continue
2865 to execute freely. This is referred to as non-stop mode, with the
2866 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2867 section in the user manual for more information.
2869 To be able to support remote non-stop debugging, a remote stub needs
2870 to implement the non-stop mode remote protocol extensions, as
2871 described in the "Remote Non-Stop" section of the user manual. The
2872 GDB remote stub, gdbserver, has been adjusted to support these
2873 extensions on linux targets.
2875 * New commands (for set/show, see "New options" below)
2877 catch syscall [NAME(S) | NUMBER(S)]
2878 Catch system calls. Arguments, which should be names of system
2879 calls or their numbers, mean catch only those syscalls. Without
2880 arguments, every syscall will be caught. When the inferior issues
2881 any of the specified syscalls, GDB will stop and announce the system
2882 call, both when it is called and when its call returns. This
2883 feature is currently available with a native GDB running on the
2884 Linux Kernel, under the following architectures: x86, x86_64,
2885 PowerPC and PowerPC64.
2887 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2889 Search memory for a sequence of bytes.
2891 maint set python print-stack
2892 maint show python print-stack
2893 Show a stack trace when an error is encountered in a Python script.
2896 Invoke CODE by passing it to the Python interpreter.
2901 These allow macros to be defined, undefined, and listed
2905 Show operating system information about processes.
2908 List the inferiors currently under GDB's control.
2911 Switch focus to inferior number NUM.
2914 Detach from inferior number NUM.
2917 Kill inferior number NUM.
2921 set spu stop-on-load
2922 show spu stop-on-load
2923 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2925 set spu auto-flush-cache
2926 show spu auto-flush-cache
2927 Control whether to automatically flush the software-managed cache
2928 during Cell/B.E. debugging.
2930 set sh calling-convention
2931 show sh calling-convention
2932 Control the calling convention used when calling SH target functions.
2935 show debug timestamp
2936 Control display of timestamps with GDB debugging output.
2938 set disassemble-next-line
2939 show disassemble-next-line
2940 Control display of disassembled source lines or instructions when
2943 set remote noack-packet
2944 show remote noack-packet
2945 Set/show the use of remote protocol QStartNoAckMode packet. See above
2946 under "New remote packets."
2948 set remote query-attached-packet
2949 show remote query-attached-packet
2950 Control use of remote protocol `qAttached' (query-attached) packet.
2952 set remote read-siginfo-object
2953 show remote read-siginfo-object
2954 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2957 set remote write-siginfo-object
2958 show remote write-siginfo-object
2959 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2962 set remote reverse-continue
2963 show remote reverse-continue
2964 Control use of remote protocol 'bc' (reverse-continue) packet.
2966 set remote reverse-step
2967 show remote reverse-step
2968 Control use of remote protocol 'bs' (reverse-step) packet.
2970 set displaced-stepping
2971 show displaced-stepping
2972 Control displaced stepping mode. Displaced stepping is a way to
2973 single-step over breakpoints without removing them from the debuggee.
2974 Also known as "out-of-line single-stepping".
2977 show debug displaced
2978 Control display of debugging info for displaced stepping.
2980 maint set internal-error
2981 maint show internal-error
2982 Control what GDB does when an internal error is detected.
2984 maint set internal-warning
2985 maint show internal-warning
2986 Control what GDB does when an internal warning is detected.
2991 Use a wrapper program to launch programs for debugging.
2993 set multiple-symbols (all|ask|cancel)
2994 show multiple-symbols
2995 The value of this variable can be changed to adjust the debugger behavior
2996 when an expression or a breakpoint location contains an ambiguous symbol
2997 name (an overloaded function name, for instance).
2999 set breakpoint always-inserted
3000 show breakpoint always-inserted
3001 Keep breakpoints always inserted in the target, as opposed to inserting
3002 them when resuming the target, and removing them when the target stops.
3003 This option can improve debugger performance on slow remote targets.
3005 set arm fallback-mode (arm|thumb|auto)
3006 show arm fallback-mode
3007 set arm force-mode (arm|thumb|auto)
3009 These commands control how ARM GDB determines whether instructions
3010 are ARM or Thumb. The default for both settings is auto, which uses
3011 the current CPSR value for instructions without symbols; previous
3012 versions of GDB behaved as if "set arm fallback-mode arm".
3014 set disable-randomization
3015 show disable-randomization
3016 Standalone programs run with the virtual address space randomization enabled
3017 by default on some platforms. This option keeps the addresses stable across
3018 multiple debugging sessions.
3022 Control whether other threads are stopped or not when some thread hits
3027 Requests that asynchronous execution is enabled in the target, if available.
3028 In this case, it's possible to resume target in the background, and interact
3029 with GDB while the target is running. "show target-async" displays the
3030 current state of asynchronous execution of the target.
3032 set target-wide-charset
3033 show target-wide-charset
3034 The target-wide-charset is the name of the character set that GDB
3035 uses when printing characters whose type is wchar_t.
3037 set tcp auto-retry (on|off)
3039 set tcp connect-timeout
3040 show tcp connect-timeout
3041 These commands allow GDB to retry failed TCP connections to a remote stub
3042 with a specified timeout period; this is useful if the stub is launched
3043 in parallel with GDB but may not be ready to accept connections immediately.
3045 set libthread-db-search-path
3046 show libthread-db-search-path
3047 Control list of directories which GDB will search for appropriate
3050 set schedule-multiple (on|off)
3051 show schedule-multiple
3052 Allow GDB to resume all threads of all processes or only threads of
3053 the current process.
3057 Use more aggressive caching for accesses to the stack. This improves
3058 performance of remote debugging (particularly backtraces) without
3059 affecting correctness.
3061 set interactive-mode (on|off|auto)
3062 show interactive-mode
3063 Control whether GDB runs in interactive mode (on) or not (off).
3064 When in interactive mode, GDB waits for the user to answer all
3065 queries. Otherwise, GDB does not wait and assumes the default
3066 answer. When set to auto (the default), GDB determines which
3067 mode to use based on the stdin settings.
3072 For program forks, this is replaced by the new more generic `info
3073 inferiors' command. To list checkpoints, you can still use the
3074 `info checkpoints' command, which was an alias for the `info forks'
3078 Replaced by the new `inferior' command. To switch between
3079 checkpoints, you can still use the `restart' command, which was an
3080 alias for the `fork' command.
3083 This is removed, since some targets don't have a notion of
3084 processes. To switch between processes, you can still use the
3085 `inferior' command using GDB's own inferior number.
3088 For program forks, this is replaced by the new more generic `kill
3089 inferior' command. To delete a checkpoint, you can still use the
3090 `delete checkpoint' command, which was an alias for the `delete
3094 For program forks, this is replaced by the new more generic `detach
3095 inferior' command. To detach a checkpoint, you can still use the
3096 `detach checkpoint' command, which was an alias for the `detach
3099 * New native configurations
3101 x86/x86_64 Darwin i[34567]86-*-darwin*
3103 x86_64 MinGW x86_64-*-mingw*
3107 Lattice Mico32 lm32-*
3108 x86 DICOS i[34567]86-*-dicos*
3109 x86_64 DICOS x86_64-*-dicos*
3112 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3113 (mingw32ce) debugging.
3119 These commands were actually not implemented on any target.
3121 *** Changes in GDB 6.8
3123 * New native configurations
3125 NetBSD/hppa hppa*-*netbsd*
3126 Xtensa GNU/Linux xtensa*-*-linux*
3130 NetBSD/hppa hppa*-*-netbsd*
3131 Xtensa GNU/Lunux xtensa*-*-linux*
3133 * Change in command line behavior -- corefiles vs. process ids.
3135 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3136 attaching to process NUMBER fails, GDB no longer attempts to open a
3137 core file named NUMBER. Attaching to a program using the -c option
3138 is no longer supported. Instead, use the '-p' or '--pid' options.
3140 * GDB can now be built as a native debugger for debugging Windows x86
3141 (mingw32) Portable Executable (PE) programs.
3143 * Pending breakpoints no longer change their number when their address
3146 * GDB now supports breakpoints with multiple locations,
3147 including breakpoints on C++ constructors, inside C++ templates,
3148 and in inlined functions.
3150 * GDB's ability to debug optimized code has been improved. GDB more
3151 accurately identifies function bodies and lexical blocks that occupy
3152 more than one contiguous range of addresses.
3154 * Target descriptions can now describe registers for PowerPC.
3156 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3157 registers on PowerPC targets.
3159 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3160 targets even when the libthread_db library is not available.
3162 * The GDB remote stub, gdbserver, now supports the new file transfer
3163 commands (remote put, remote get, and remote delete).
3165 * The GDB remote stub, gdbserver, now supports run and attach in
3166 extended-remote mode.
3168 * hppa*64*-*-hpux11* target broken
3169 The debugger is unable to start a program and fails with the following
3170 error: "Error trying to get information about dynamic linker".
3171 The gdb-6.7 release is also affected.
3173 * GDB now supports the --enable-targets= configure option to allow
3174 building a single GDB executable that supports multiple remote
3175 target architectures.
3177 * GDB now supports debugging C and C++ programs which use the
3178 Decimal Floating Point extension. In addition, the PowerPC target
3179 now has a set of pseudo-registers to inspect decimal float values
3180 stored in two consecutive float registers.
3182 * The -break-insert MI command can optionally create pending
3185 * Improved support for debugging Ada
3186 Many improvements to the Ada language support have been made. These
3188 - Better support for Ada2005 interface types
3189 - Improved handling of arrays and slices in general
3190 - Better support for Taft-amendment types
3191 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3193 - Improved command completion in Ada
3196 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3201 set print frame-arguments (all|scalars|none)
3202 show print frame-arguments
3203 The value of this variable can be changed to control which argument
3204 values should be printed by the debugger when displaying a frame.
3209 Transfer files to and from a remote target, and delete remote files.
3216 Transfer files to and from a remote target, and delete remote files.
3218 * New remote packets
3225 Open, close, read, write, and delete files on the remote system.
3228 Attach to an existing process on the remote system, in extended-remote
3232 Run a new process on the remote system, in extended-remote mode.
3234 *** Changes in GDB 6.7
3236 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3237 bfd, libiberty and opcodes, as revealed by static analysis donated by
3238 Coverity, Inc. (http://scan.coverity.com).
3240 * When looking up multiply-defined global symbols, GDB will now prefer the
3241 symbol definition in the current shared library if it was built using the
3242 -Bsymbolic linker option.
3244 * When the Text User Interface (TUI) is not configured, GDB will now
3245 recognize the -tui command-line option and print a message that the TUI
3248 * The GDB remote stub, gdbserver, now has lower overhead for high
3249 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3251 * GDB for MIPS targets now autodetects whether a remote target provides
3252 32-bit or 64-bit register values.
3254 * Support for C++ member pointers has been improved.
3256 * GDB now understands XML target descriptions, which specify the
3257 target's overall architecture. GDB can read a description from
3258 a local file or over the remote serial protocol.
3260 * Vectors of single-byte data use a new integer type which is not
3261 automatically displayed as character or string data.
3263 * The /s format now works with the print command. It displays
3264 arrays of single-byte integers and pointers to single-byte integers
3267 * Target descriptions can now describe target-specific registers,
3268 for architectures which have implemented the support (currently
3269 only ARM, M68K, and MIPS).
3271 * GDB and the GDB remote stub, gdbserver, now support the XScale
3274 * The GDB remote stub, gdbserver, has been updated to support
3275 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3276 has been rewritten to use the standard GDB remote protocol.
3278 * GDB can now step into C++ functions which are called through thunks.
3280 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3282 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3283 layout. It also supports a TextSeg= and DataSeg= response when only
3284 segment base addresses (rather than offsets) are available.
3286 * The /i format now outputs any trailing branch delay slot instructions
3287 immediately following the last instruction within the count specified.
3289 * The GDB remote protocol "T" stop reply packet now supports a
3290 "library" response. Combined with the new "qXfer:libraries:read"
3291 packet, this response allows GDB to debug shared libraries on targets
3292 where the operating system manages the list of loaded libraries (e.g.
3293 Windows and SymbianOS).
3295 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3296 (DLLs) on Windows and Windows CE targets.
3298 * GDB now supports a faster verification that a .debug file matches its binary
3299 according to its build-id signature, if the signature is present.
3305 Enable or disable hardware flow control (RTS/CTS) on the serial port
3306 when debugging using remote targets.
3308 set mem inaccessible-by-default
3309 show mem inaccessible-by-default
3310 If the target supplies a memory map, for instance via the remote
3311 protocol's "qXfer:memory-map:read" packet, setting this variable
3312 prevents GDB from accessing memory outside the memory map. This
3313 is useful for targets with memory mapped registers or which react
3314 badly to accesses of unmapped address space.
3316 set breakpoint auto-hw
3317 show breakpoint auto-hw
3318 If the target supplies a memory map, for instance via the remote
3319 protocol's "qXfer:memory-map:read" packet, setting this variable
3320 lets GDB use hardware breakpoints automatically for memory regions
3321 where it can not use software breakpoints. This covers both the
3322 "break" command and internal breakpoints used for other commands
3323 including "next" and "finish".
3326 catch exception unhandled
3327 Stop the program execution when Ada exceptions are raised.
3330 Stop the program execution when an Ada assertion failed.
3334 Set an alternate system root for target files. This is a more
3335 general version of "set solib-absolute-prefix", which is now
3336 an alias to "set sysroot".
3339 Provide extended SPU facility status information. This set of
3340 commands is available only when debugging the Cell/B.E. SPU
3343 * New native configurations
3345 OpenBSD/sh sh*-*openbsd*
3348 unset tdesc filename
3350 Use the specified local file as an XML target description, and do
3351 not query the target for its built-in description.
3355 OpenBSD/sh sh*-*-openbsd*
3356 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3357 Toshiba Media Processor mep-elf
3359 * New remote packets
3362 Ignore the specified signals; pass them directly to the debugged program
3363 without stopping other threads or reporting them to GDB.
3365 qXfer:features:read:
3366 Read an XML target description from the target, which describes its
3371 Read or write contents of an spufs file on the target system. These
3372 packets are available only on the Cell/B.E. SPU architecture.
3374 qXfer:libraries:read:
3375 Report the loaded shared libraries. Combined with new "T" packet
3376 response, this packet allows GDB to debug shared libraries on
3377 targets where the operating system manages the list of loaded
3378 libraries (e.g. Windows and SymbianOS).
3382 Support for these obsolete configurations has been removed.
3390 i[34567]86-*-lynxos*
3391 i[34567]86-*-netware*
3392 i[34567]86-*-sco3.2v5*
3393 i[34567]86-*-sco3.2v4*
3395 i[34567]86-*-sysv4.2*
3398 i[34567]86-*-unixware2*
3399 i[34567]86-*-unixware*
3408 * Other removed features
3415 Various m68k-only ROM monitors.
3422 Various Renesas ROM monitors and debugging interfaces for SH and
3427 Support for a Macraigor serial interface to on-chip debugging.
3428 GDB does not directly support the newer parallel or USB
3433 A debug information format. The predecessor to DWARF 2 and
3434 DWARF 3, which are still supported.
3436 Support for the HP aCC compiler on HP-UX/PA-RISC
3438 SOM-encapsulated symbolic debugging information, automatic
3439 invocation of pxdb, and the aCC custom C++ ABI. This does not
3440 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3441 with aCC can still be debugged on an assembly level.
3443 MIPS ".pdr" sections
3445 A MIPS-specific format used to describe stack frame layout
3446 in debugging information.
3450 GDB could work with an older version of Guile to debug
3451 the interpreter and Scheme programs running in it.
3453 set mips stack-arg-size
3454 set mips saved-gpreg-size
3456 Use "set mips abi" to control parameter passing for MIPS.
3458 *** Changes in GDB 6.6
3463 Cell Broadband Engine SPU spu-elf
3465 * GDB can now be configured as a cross-debugger targeting native Windows
3466 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3467 running on a Windows system over TCP/IP to debug Windows programs.
3469 * The GDB remote stub, gdbserver, has been updated to support Windows and
3470 Cygwin debugging. Both single-threaded and multi-threaded programs are
3473 * The "set trust-readonly-sections" command works again. This command was
3474 broken in GDB 6.3, 6.4, and 6.5.
3476 * The "load" command now supports writing to flash memory, if the remote
3477 stub provides the required support.
3479 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3480 longer requires symbolic debug information (e.g. DWARF-2).
3485 unset substitute-path
3486 show substitute-path
3487 Manage a list of substitution rules that GDB uses to rewrite the name
3488 of the directories where the sources are located. This can be useful
3489 for instance when the sources were moved to a different location
3490 between compilation and debugging.
3494 Print each CLI command as it is executed. Each command is prefixed with
3495 a number of `+' symbols representing the nesting depth.
3496 The source command now has a `-v' option to enable the same feature.
3500 The ARM Demon monitor support (RDP protocol, "target rdp").
3502 Kernel Object Display, an embedded debugging feature which only worked with
3503 an obsolete version of Cisco IOS.
3505 The 'set download-write-size' and 'show download-write-size' commands.
3507 * New remote packets
3510 Tell a stub about GDB client features, and request remote target features.
3511 The first feature implemented is PacketSize, which allows the target to
3512 specify the size of packets it can handle - to minimize the number of
3513 packets required and improve performance when connected to a remote
3517 Fetch an OS auxilliary vector from the remote stub. This packet is a
3518 more efficient replacement for qPart:auxv:read.
3520 qXfer:memory-map:read:
3521 Fetch a memory map from the remote stub, including information about
3522 RAM, ROM, and flash memory devices.
3527 Erase and program a flash memory device.
3529 * Removed remote packets
3532 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3533 used it, and only gdbserver implemented it.
3535 *** Changes in GDB 6.5
3539 Renesas M32C/M16C m32c-elf
3541 Morpho Technologies ms1 ms1-elf
3545 init-if-undefined Initialize a convenience variable, but
3546 only if it doesn't already have a value.
3548 The following commands are presently only implemented for native GNU/Linux:
3550 checkpoint Save a snapshot of the program state.
3552 restart <n> Return the program state to a
3553 previously saved state.
3555 info checkpoints List currently saved checkpoints.
3557 delete-checkpoint <n> Delete a previously saved checkpoint.
3559 set|show detach-on-fork Tell gdb whether to detach from a newly
3560 forked process, or to keep debugging it.
3562 info forks List forks of the user program that
3563 are available to be debugged.
3565 fork <n> Switch to debugging one of several
3566 forks of the user program that are
3567 available to be debugged.
3569 delete-fork <n> Delete a fork from the list of forks
3570 that are available to be debugged (and
3571 kill the forked process).
3573 detach-fork <n> Delete a fork from the list of forks
3574 that are available to be debugged (and
3575 allow the process to continue).
3579 Morpho Technologies ms2 ms1-elf
3581 * Improved Windows host support
3583 GDB now builds as a cross debugger hosted on i686-mingw32, including
3584 native console support, and remote communications using either
3585 network sockets or serial ports.
3587 * Improved Modula-2 language support
3589 GDB can now print most types in the Modula-2 syntax. This includes:
3590 basic types, set types, record types, enumerated types, range types,
3591 pointer types and ARRAY types. Procedure var parameters are correctly
3592 printed and hexadecimal addresses and character constants are also
3593 written in the Modula-2 syntax. Best results can be obtained by using
3594 GNU Modula-2 together with the -gdwarf-2 command line option.
3598 The ARM rdi-share module.
3600 The Netware NLM debug server.
3602 *** Changes in GDB 6.4
3604 * New native configurations
3606 OpenBSD/arm arm*-*-openbsd*
3607 OpenBSD/mips64 mips64-*-openbsd*
3611 Morpho Technologies ms1 ms1-elf
3613 * New command line options
3615 --batch-silent As for --batch, but totally silent.
3616 --return-child-result The debugger will exist with the same value
3617 the child (debugged) program exited with.
3618 --eval-command COMMAND, -ex COMMAND
3619 Execute a single GDB CLI command. This may be
3620 specified multiple times and in conjunction
3621 with the --command (-x) option.
3623 * Deprecated commands removed
3625 The following commands, that were deprecated in 2000, have been
3629 set|show arm disassembly-flavor set|show arm disassembler
3630 othernames set arm disassembler
3631 set|show remotedebug set|show debug remote
3632 set|show archdebug set|show debug arch
3633 set|show eventdebug set|show debug event
3636 * New BSD user-level threads support
3638 It is now possible to debug programs using the user-level threads
3639 library on OpenBSD and FreeBSD. Currently supported (target)
3642 FreeBSD/amd64 x86_64-*-freebsd*
3643 FreeBSD/i386 i386-*-freebsd*
3644 OpenBSD/i386 i386-*-openbsd*
3646 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3647 are not yet supported.
3649 * New support for Matsushita MN10300 w/sim added
3650 (Work in progress). mn10300-elf.
3652 * REMOVED configurations and files
3654 VxWorks and the XDR protocol *-*-vxworks
3655 Motorola MCORE mcore-*-*
3656 National Semiconductor NS32000 ns32k-*-*
3658 * New "set print array-indexes" command
3660 After turning this setting "on", GDB prints the index of each element
3661 when displaying arrays. The default is "off" to preserve the previous
3664 * VAX floating point support
3666 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3668 * User-defined command support
3670 In addition to using $arg0..$arg9 for argument passing, it is now possible
3671 to use $argc to determine now many arguments have been passed. See the
3672 section on user-defined commands in the user manual for more information.
3674 *** Changes in GDB 6.3:
3676 * New command line option
3678 GDB now accepts -l followed by a number to set the timeout for remote
3681 * GDB works with GCC -feliminate-dwarf2-dups
3683 GDB now supports a more compact representation of DWARF-2 debug
3684 information using DW_FORM_ref_addr references. These are produced
3685 by GCC with the option -feliminate-dwarf2-dups and also by some
3686 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3687 to use -feliminate-dwarf2-dups.
3689 * Internationalization
3691 When supported by the host system, GDB will be built with
3692 internationalization (libintl). The task of marking up the sources is
3693 continued, we're looking forward to our first translation.
3697 Initial support for debugging programs compiled with the GNAT
3698 implementation of the Ada programming language has been integrated
3699 into GDB. In this release, support is limited to expression evaluation.
3701 * New native configurations
3703 GNU/Linux/m32r m32r-*-linux-gnu
3707 GDB's remote protocol now includes support for the 'p' packet. This
3708 packet is used to fetch individual registers from a remote inferior.
3710 * END-OF-LIFE registers[] compatibility module
3712 GDB's internal register infrastructure has been completely rewritten.
3713 The new infrastructure making possible the implementation of key new
3714 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3717 GDB 6.3 will be the last release to include the the registers[]
3718 compatibility module that allowed out-of-date configurations to
3719 continue to work. This change directly impacts the following
3729 powerpc bdm protocol
3731 Unless there is activity to revive these configurations, they will be
3732 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3734 * OBSOLETE configurations and files
3736 Configurations that have been declared obsolete in this release have
3737 been commented out. Unless there is activity to revive these
3738 configurations, the next release of GDB will have their sources
3739 permanently REMOVED.
3748 *** Changes in GDB 6.2.1:
3750 * MIPS `break main; run' gave an heuristic-fence-post warning
3752 When attempting to run even a simple program, a warning about
3753 heuristic-fence-post being hit would be reported. This problem has
3756 * MIPS IRIX 'long double' crashed GDB
3758 When examining a long double variable, GDB would get a segmentation
3759 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3760 IRIX long double values).
3764 A bug in the VAX stack code was causing problems with the "next"
3765 command. This problem has been fixed.
3767 *** Changes in GDB 6.2:
3769 * Fix for ``many threads''
3771 On GNU/Linux systems that use the NPTL threads library, a program
3772 rapidly creating and deleting threads would confuse GDB leading to the
3775 ptrace: No such process.
3776 thread_db_get_info: cannot get thread info: generic error
3778 This problem has been fixed.
3780 * "-async" and "-noasync" options removed.
3782 Support for the broken "-noasync" option has been removed (it caused
3785 * New ``start'' command.
3787 This command runs the program until the begining of the main procedure.
3789 * New BSD Kernel Data Access Library (libkvm) interface
3791 Using ``target kvm'' it is now possible to debug kernel core dumps and
3792 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3793 platforms. Currently supported (native-only) configurations are:
3795 FreeBSD/amd64 x86_64-*-freebsd*
3796 FreeBSD/i386 i?86-*-freebsd*
3797 NetBSD/i386 i?86-*-netbsd*
3798 NetBSD/m68k m68*-*-netbsd*
3799 NetBSD/sparc sparc-*-netbsd*
3800 OpenBSD/amd64 x86_64-*-openbsd*
3801 OpenBSD/i386 i?86-*-openbsd*
3802 OpenBSD/m68k m68*-openbsd*
3803 OpenBSD/sparc sparc-*-openbsd*
3805 * Signal trampoline code overhauled
3807 Many generic problems with GDB's signal handling code have been fixed.
3808 These include: backtraces through non-contiguous stacks; recognition
3809 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3810 call; backtrace through a signal trampoline; step into and out of
3811 signal handlers; and single-stepping in the signal trampoline.
3813 Please note that kernel bugs are a limiting factor here. These
3814 features have been shown to work on an s390 GNU/Linux system that
3815 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3817 * Cygwin support for DWARF 2 added.
3819 * New native configurations
3821 GNU/Linux/hppa hppa*-*-linux*
3822 OpenBSD/hppa hppa*-*-openbsd*
3823 OpenBSD/m68k m68*-*-openbsd*
3824 OpenBSD/m88k m88*-*-openbsd*
3825 OpenBSD/powerpc powerpc-*-openbsd*
3826 NetBSD/vax vax-*-netbsd*
3827 OpenBSD/vax vax-*-openbsd*
3829 * END-OF-LIFE frame compatibility module
3831 GDB's internal frame infrastructure has been completely rewritten.
3832 The new infrastructure making it possible to support key new features
3833 including DWARF 2 Call Frame Information. To aid in the task of
3834 migrating old configurations to this new infrastructure, a
3835 compatibility module, that allowed old configurations to continue to
3836 work, was also included.
3838 GDB 6.2 will be the last release to include this frame compatibility
3839 module. This change directly impacts the following configurations:
3849 Unless there is activity to revive these configurations, they will be
3850 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3852 * REMOVED configurations and files
3854 Sun 3, running SunOS 3 m68*-*-sunos3*
3855 Sun 3, running SunOS 4 m68*-*-sunos4*
3856 Sun 2, running SunOS 3 m68000-*-sunos3*
3857 Sun 2, running SunOS 4 m68000-*-sunos4*
3858 Motorola 680x0 running LynxOS m68*-*-lynxos*
3859 AT&T 3b1/Unix pc m68*-att-*
3860 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3861 decstation mips-dec-* mips-little-*
3862 riscos mips-*-riscos* mips-*-sysv*
3863 sonymips mips-sony-*
3864 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3866 *** Changes in GDB 6.1.1:
3868 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3870 The TUI (Text-mode User Interface) is now built as part of a default
3871 GDB configuration. It is enabled by either selecting the TUI with the
3872 command line option "-i=tui" or by running the separate "gdbtui"
3873 program. For more information on the TUI, see the manual "Debugging
3876 * Pending breakpoint support (also included in GDB 6.1)
3878 Support has been added to allow you to specify breakpoints in shared
3879 libraries that have not yet been loaded. If a breakpoint location
3880 cannot be found, and the "breakpoint pending" option is set to auto,
3881 GDB queries you if you wish to make the breakpoint pending on a future
3882 shared-library load. If and when GDB resolves the breakpoint symbol,
3883 the pending breakpoint is removed as one or more regular breakpoints
3886 Pending breakpoints are very useful for GCJ Java debugging.
3888 * Fixed ISO-C build problems
3890 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3891 non ISO-C code that stopped them being built using a more strict ISO-C
3892 compiler (e.g., IBM's C compiler).
3894 * Fixed build problem on IRIX 5
3896 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3897 wasn't able to compile compile on an IRIX 5 system.
3899 * Added execute permission to gdb/gdbserver/configure
3901 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3902 permission. This bug would cause configure to fail on a number of
3903 systems (Solaris, IRIX). Ref: server/519.
3905 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3907 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3908 has been updated to use constant array sizes.
3910 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3912 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3913 its generated DWARF Call Frame Info. This encoding was causing GDB to
3914 panic, that panic has been fixed. Ref: gdb/1628.
3916 * Fixed a problem when examining parameters in shared library code.
3918 When examining parameters in optimized shared library code generated
3919 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3920 not available''. GDB now correctly displays the variable's value.
3922 *** Changes in GDB 6.1:
3924 * Removed --with-mmalloc
3926 Support for the mmalloc memory manager has been removed, as it
3927 conflicted with the internal gdb byte cache.
3929 * Changes in AMD64 configurations
3931 The AMD64 target now includes the %cs and %ss registers. As a result
3932 the AMD64 remote protocol has changed; this affects the floating-point
3933 and SSE registers. If you rely on those registers for your debugging,
3934 you should upgrade gdbserver on the remote side.
3936 * Revised SPARC target
3938 The SPARC target has been completely revised, incorporating the
3939 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3940 support for LynxOS and SunOS 4 has been dropped. Calling functions
3941 from within GDB on operating systems with a non-executable stack
3942 (Solaris, OpenBSD) now works.
3946 GDB has a new C++ demangler which does a better job on the mangled
3947 names generated by current versions of g++. It also runs faster, so
3948 with this and other changes gdb should now start faster on large C++
3951 * DWARF 2 Location Expressions
3953 GDB support for location expressions has been extended to support function
3954 arguments and frame bases. Older versions of GDB could crash when they
3957 * C++ nested types and namespaces
3959 GDB's support for nested types and namespaces in C++ has been
3960 improved, especially if you use the DWARF 2 debugging format. (This
3961 is the default for recent versions of GCC on most platforms.)
3962 Specifically, if you have a class "Inner" defined within a class or
3963 namespace "Outer", then GDB realizes that the class's name is
3964 "Outer::Inner", not simply "Inner". This should greatly reduce the
3965 frequency of complaints about not finding RTTI symbols. In addition,
3966 if you are stopped at inside of a function defined within a namespace,
3967 GDB modifies its name lookup accordingly.
3969 * New native configurations
3971 NetBSD/amd64 x86_64-*-netbsd*
3972 OpenBSD/amd64 x86_64-*-openbsd*
3973 OpenBSD/alpha alpha*-*-openbsd*
3974 OpenBSD/sparc sparc-*-openbsd*
3975 OpenBSD/sparc64 sparc64-*-openbsd*
3977 * New debugging protocols
3979 M32R with SDI protocol m32r-*-elf*
3981 * "set prompt-escape-char" command deleted.
3983 The command "set prompt-escape-char" has been deleted. This command,
3984 and its very obscure effet on GDB's prompt, was never documented,
3985 tested, nor mentioned in the NEWS file.
3987 * OBSOLETE configurations and files
3989 Configurations that have been declared obsolete in this release have
3990 been commented out. Unless there is activity to revive these
3991 configurations, the next release of GDB will have their sources
3992 permanently REMOVED.
3994 Sun 3, running SunOS 3 m68*-*-sunos3*
3995 Sun 3, running SunOS 4 m68*-*-sunos4*
3996 Sun 2, running SunOS 3 m68000-*-sunos3*
3997 Sun 2, running SunOS 4 m68000-*-sunos4*
3998 Motorola 680x0 running LynxOS m68*-*-lynxos*
3999 AT&T 3b1/Unix pc m68*-att-*
4000 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4001 decstation mips-dec-* mips-little-*
4002 riscos mips-*-riscos* mips-*-sysv*
4003 sonymips mips-sony-*
4004 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4006 * REMOVED configurations and files
4008 SGI Irix-4.x mips-sgi-irix4 or iris4
4009 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4010 Z8000 simulator z8k-zilog-none or z8ksim
4011 Matsushita MN10200 w/simulator mn10200-*-*
4012 H8/500 simulator h8500-hitachi-hms or h8500hms
4013 HP/PA running BSD hppa*-*-bsd*
4014 HP/PA running OSF/1 hppa*-*-osf*
4015 HP/PA Pro target hppa*-*-pro*
4016 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4017 386BSD i[3456]86-*-bsd*
4018 Sequent family i[3456]86-sequent-sysv4*
4019 i[3456]86-sequent-sysv*
4020 i[3456]86-sequent-bsd*
4021 SPARC running LynxOS sparc-*-lynxos*
4022 SPARC running SunOS 4 sparc-*-sunos4*
4023 Tsqware Sparclet sparclet-*-*
4024 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4026 *** Changes in GDB 6.0:
4030 Support for debugging the Objective-C programming language has been
4031 integrated into GDB.
4033 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4035 DWARF 2's Call Frame Information makes available compiler generated
4036 information that more exactly describes the program's run-time stack.
4037 By using this information, GDB is able to provide more robust stack
4040 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4041 have been updated to use a new backtrace mechanism which includes
4042 DWARF 2 CFI support.
4046 GDB's remote protocol has been extended to include support for hosted
4047 file I/O (where the remote target uses GDB's file system). See GDB's
4048 remote protocol documentation for details.
4050 * All targets using the new architecture framework.
4052 All of GDB's targets have been updated to use the new internal
4053 architecture framework. The way is now open for future GDB releases
4054 to include cross-architecture native debugging support (i386 on amd64,
4057 * GNU/Linux's Thread Local Storage (TLS)
4059 GDB now includes support for for the GNU/Linux implementation of
4060 per-thread variables.
4062 * GNU/Linux's Native POSIX Thread Library (NPTL)
4064 GDB's thread code has been updated to work with either the new
4065 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4067 * Separate debug info.
4069 GDB, in conjunction with BINUTILS, now supports a mechanism for
4070 automatically loading debug information from a separate file. Instead
4071 of shipping full debug and non-debug versions of system libraries,
4072 system integrators can now instead ship just the stripped libraries
4073 and optional debug files.
4075 * DWARF 2 Location Expressions
4077 DWARF 2 Location Expressions allow the compiler to more completely
4078 describe the location of variables (even in optimized code) to the
4081 GDB now includes preliminary support for location expressions (support
4082 for DW_OP_piece is still missing).
4086 A number of long standing bugs that caused GDB to die while starting a
4087 Java application have been fixed. GDB's Java support is now
4088 considered "useable".
4090 * GNU/Linux support for fork, vfork, and exec.
4092 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4093 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4096 * GDB supports logging output to a file
4098 There are two new commands, "set logging" and "show logging", which can be
4099 used to capture GDB's output to a file.
4101 * The meaning of "detach" has changed for gdbserver
4103 The "detach" command will now resume the application, as documented. To
4104 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4107 * d10v, m68hc11 `regs' command deprecated
4109 The `info registers' command has been updated so that it displays the
4110 registers using a format identical to the old `regs' command.
4114 A new command, "maint set profile on/off", has been added. This command can
4115 be used to enable or disable profiling while running GDB, to profile a
4116 session or a set of commands. In addition there is a new configure switch,
4117 "--enable-profiling", which will cause GDB to be compiled with profiling
4118 data, for more informative profiling results.
4120 * Default MI syntax changed to "mi2".
4122 The default MI (machine interface) syntax, enabled by the command line
4123 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4124 "mi1", can be enabled by specifying the option "-i=mi1".
4126 Support for the original "mi0" syntax (included in GDB 5.0) has been
4129 Fix for gdb/192: removed extraneous space when displaying frame level.
4130 Fix for gdb/672: update changelist is now output in mi list format.
4131 Fix for gdb/702: a -var-assign that updates the value now shows up
4132 in a subsequent -var-update.
4134 * New native configurations.
4136 FreeBSD/amd64 x86_64-*-freebsd*
4138 * Multi-arched targets.
4140 HP/PA HPUX11 hppa*-*-hpux*
4141 Renesas M32R/D w/simulator m32r-*-elf*
4143 * OBSOLETE configurations and files
4145 Configurations that have been declared obsolete in this release have
4146 been commented out. Unless there is activity to revive these
4147 configurations, the next release of GDB will have their sources
4148 permanently REMOVED.
4150 Z8000 simulator z8k-zilog-none or z8ksim
4151 Matsushita MN10200 w/simulator mn10200-*-*
4152 H8/500 simulator h8500-hitachi-hms or h8500hms
4153 HP/PA running BSD hppa*-*-bsd*
4154 HP/PA running OSF/1 hppa*-*-osf*
4155 HP/PA Pro target hppa*-*-pro*
4156 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4157 Sequent family i[3456]86-sequent-sysv4*
4158 i[3456]86-sequent-sysv*
4159 i[3456]86-sequent-bsd*
4160 Tsqware Sparclet sparclet-*-*
4161 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4163 * REMOVED configurations and files
4166 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4167 IBM AIX PS/2 i[3456]86-*-aix
4168 i386 running Mach 3.0 i[3456]86-*-mach3*
4169 i386 running Mach i[3456]86-*-mach*
4170 i386 running OSF/1 i[3456]86-*osf1mk*
4171 HP/Apollo 68k Family m68*-apollo*-sysv*,
4173 m68*-hp-bsd*, m68*-hp-hpux*
4174 Argonaut Risc Chip (ARC) arc-*-*
4175 Mitsubishi D30V d30v-*-*
4176 Fujitsu FR30 fr30-*-elf*
4177 OS/9000 i[34]86-*-os9k
4178 I960 with MON960 i960-*-coff
4180 * MIPS $fp behavior changed
4182 The convenience variable $fp, for the MIPS, now consistently returns
4183 the address of the current frame's base. Previously, depending on the
4184 context, $fp could refer to either $sp or the current frame's base
4185 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4186 The GNU Source-Level Debugger''.
4188 *** Changes in GDB 5.3:
4190 * GNU/Linux shared library multi-threaded performance improved.
4192 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4193 `/proc', in preference to `ptrace' for memory reads. This may result
4194 in an improvement in the start-up time of multi-threaded, shared
4195 library applications when run under GDB. One GDB user writes: ``loads
4196 shared libs like mad''.
4198 * ``gdbserver'' now supports multi-threaded applications on some targets
4200 Support for debugging multi-threaded applications which use
4201 the GNU/Linux LinuxThreads package has been added for
4202 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4203 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4205 * GDB now supports C/C++ preprocessor macros.
4207 GDB now expands preprocessor macro invocations in C/C++ expressions,
4208 and provides various commands for showing macro definitions and how
4211 The new command `macro expand EXPRESSION' expands any macro
4212 invocations in expression, and shows the result.
4214 The new command `show macro MACRO-NAME' shows the definition of the
4215 macro named MACRO-NAME, and where it was defined.
4217 Most compilers don't include information about macros in the debugging
4218 information by default. In GCC 3.1, for example, you need to compile
4219 your program with the options `-gdwarf-2 -g3'. If the macro
4220 information is present in the executable, GDB will read it.
4222 * Multi-arched targets.
4224 DEC Alpha (partial) alpha*-*-*
4225 DEC VAX (partial) vax-*-*
4227 National Semiconductor NS32000 (partial) ns32k-*-*
4228 Motorola 68000 (partial) m68k-*-*
4229 Motorola MCORE mcore-*-*
4233 Fujitsu FRV architecture added by Red Hat frv*-*-*
4236 * New native configurations
4238 Alpha NetBSD alpha*-*-netbsd*
4239 SH NetBSD sh*-*-netbsdelf*
4240 MIPS NetBSD mips*-*-netbsd*
4241 UltraSPARC NetBSD sparc64-*-netbsd*
4243 * OBSOLETE configurations and files
4245 Configurations that have been declared obsolete in this release have
4246 been commented out. Unless there is activity to revive these
4247 configurations, the next release of GDB will have their sources
4248 permanently REMOVED.
4250 Mitsubishi D30V d30v-*-*
4251 OS/9000 i[34]86-*-os9k
4252 IBM AIX PS/2 i[3456]86-*-aix
4253 Fujitsu FR30 fr30-*-elf*
4254 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4255 Argonaut Risc Chip (ARC) arc-*-*
4256 i386 running Mach 3.0 i[3456]86-*-mach3*
4257 i386 running Mach i[3456]86-*-mach*
4258 i386 running OSF/1 i[3456]86-*osf1mk*
4259 HP/Apollo 68k Family m68*-apollo*-sysv*,
4261 m68*-hp-bsd*, m68*-hp-hpux*
4262 I960 with MON960 i960-*-coff
4264 * OBSOLETE languages
4266 CHILL, a Pascal like language used by telecommunications companies.
4268 * REMOVED configurations and files
4270 AMD 29k family via UDI a29k-amd-udi, udi29k
4271 A29K VxWorks a29k-*-vxworks
4272 AMD 29000 embedded, using EBMON a29k-none-none
4273 AMD 29000 embedded with COFF a29k-none-coff
4274 AMD 29000 embedded with a.out a29k-none-aout
4276 testsuite/gdb.hp/gdb.threads-hp/ directory
4278 * New command "set max-user-call-depth <nnn>"
4280 This command allows the user to limit the call depth of user-defined
4281 commands. The default is 1024.
4283 * Changes in FreeBSD/i386 native debugging.
4285 Support for the "generate-core-file" has been added.
4287 * New commands "dump", "append", and "restore".
4289 These commands allow data to be copied from target memory
4290 to a bfd-format or binary file (dump and append), and back
4291 from a file into memory (restore).
4293 * Improved "next/step" support on multi-processor Alpha Tru64.
4295 The previous single-step mechanism could cause unpredictable problems,
4296 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4297 of a software single-step mechanism prevents this.
4299 *** Changes in GDB 5.2.1:
4307 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4308 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4309 Fix, by Joel Brobecker imported from mainline.
4311 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4312 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4313 Fix, by Fred Fish, imported from mainline.
4315 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4316 Surprisingly enough, it works now.
4317 By Michal Ludvig, imported from mainline.
4319 i386 hardware watchpoint support:
4320 avoid misses on second run for some targets.
4321 By Pierre Muller, imported from mainline.
4323 *** Changes in GDB 5.2:
4325 * New command "set trust-readonly-sections on[off]".
4327 This command is a hint that tells gdb that read-only sections
4328 really are read-only (ie. that their contents will not change).
4329 In this mode, gdb will go to the object file rather than the
4330 target to read memory from read-only sections (such as ".text").
4331 This can be a significant performance improvement on some
4332 (notably embedded) targets.
4334 * New command "generate-core-file" (or "gcore").
4336 This new gdb command allows the user to drop a core file of the child
4337 process state at any time. So far it's been implemented only for
4338 GNU/Linux and Solaris, but should be relatively easily ported to other
4339 hosts. Argument is core file name (defaults to core.<pid>).
4341 * New command line option
4343 GDB now accepts --pid or -p followed by a process id.
4345 * Change in command line behavior -- corefiles vs. process ids.
4347 There is a subtle behavior in the way in which GDB handles
4348 command line arguments. The first non-flag argument is always
4349 a program to debug, but the second non-flag argument may either
4350 be a corefile or a process id. Previously, GDB would attempt to
4351 open the second argument as a corefile, and if that failed, would
4352 issue a superfluous error message and then attempt to attach it as
4353 a process. Now, if the second argument begins with a non-digit,
4354 it will be treated as a corefile. If it begins with a digit,
4355 GDB will attempt to attach it as a process, and if no such process
4356 is found, will then attempt to open it as a corefile.
4358 * Changes in ARM configurations.
4360 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4361 configuration is fully multi-arch.
4363 * New native configurations
4365 ARM NetBSD arm*-*-netbsd*
4366 x86 OpenBSD i[3456]86-*-openbsd*
4367 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4368 Sparc64 running FreeBSD sparc64-*-freebsd*
4372 Sanyo XStormy16 xstormy16-elf
4374 * OBSOLETE configurations and files
4376 Configurations that have been declared obsolete in this release have
4377 been commented out. Unless there is activity to revive these
4378 configurations, the next release of GDB will have their sources
4379 permanently REMOVED.
4381 AMD 29k family via UDI a29k-amd-udi, udi29k
4382 A29K VxWorks a29k-*-vxworks
4383 AMD 29000 embedded, using EBMON a29k-none-none
4384 AMD 29000 embedded with COFF a29k-none-coff
4385 AMD 29000 embedded with a.out a29k-none-aout
4387 testsuite/gdb.hp/gdb.threads-hp/ directory
4389 * REMOVED configurations and files
4391 TI TMS320C80 tic80-*-*
4393 PowerPC Solaris powerpcle-*-solaris*
4394 PowerPC Windows NT powerpcle-*-cygwin32
4395 PowerPC Netware powerpc-*-netware*
4396 Harris/CXUX m88k m88*-harris-cxux*
4397 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4398 ns32k-utek-sysv* ns32k-utek-*
4399 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4400 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4401 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4402 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4403 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4405 * Changes to command line processing
4407 The new `--args' feature can be used to specify command-line arguments
4408 for the inferior from gdb's command line.
4410 * Changes to key bindings
4412 There is a new `operate-and-get-next' function bound to `C-o'.
4414 *** Changes in GDB 5.1.1
4416 Fix compile problem on DJGPP.
4418 Fix a problem with floating-point registers on the i386 being
4421 Fix to stop GDB crashing on .debug_str debug info.
4423 Numerous documentation fixes.
4425 Numerous testsuite fixes.
4427 *** Changes in GDB 5.1:
4429 * New native configurations
4431 Alpha FreeBSD alpha*-*-freebsd*
4432 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4433 MIPS GNU/Linux mips*-*-linux*
4434 MIPS SGI Irix 6.x mips*-sgi-irix6*
4435 ia64 AIX ia64-*-aix*
4436 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4440 Motorola 68HC11 and 68HC12 m68hc11-elf
4442 UltraSparc running GNU/Linux sparc64-*-linux*
4444 * OBSOLETE configurations and files
4446 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4447 Harris/CXUX m88k m88*-harris-cxux*
4448 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4449 ns32k-utek-sysv* ns32k-utek-*
4450 TI TMS320C80 tic80-*-*
4452 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4453 PowerPC Solaris powerpcle-*-solaris*
4454 PowerPC Windows NT powerpcle-*-cygwin32
4455 PowerPC Netware powerpc-*-netware*
4456 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4457 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4458 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4459 Apple Macintosh (MPW) host N/A
4461 stuff.c (Program to stuff files into a specially prepared space in kdb)
4462 kdb-start.c (Main loop for the standalone kernel debugger)
4464 Configurations that have been declared obsolete in this release have
4465 been commented out. Unless there is activity to revive these
4466 configurations, the next release of GDB will have their sources
4467 permanently REMOVED.
4469 * REMOVED configurations and files
4471 Altos 3068 m68*-altos-*
4472 Convex c1-*-*, c2-*-*
4474 ARM RISCix arm-*-* (as host)
4478 * GDB has been converted to ISO C.
4480 GDB's source code has been converted to ISO C. In particular, the
4481 sources are fully protoized, and rely on standard headers being
4486 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4488 * The MI enabled by default.
4490 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4491 revised and enabled by default. Packages which use GDB as a debugging
4492 engine behind a UI or another front end are encouraged to switch to
4493 using the GDB/MI interface, instead of the old annotations interface
4494 which is now deprecated.
4496 * Support for debugging Pascal programs.
4498 GDB now includes support for debugging Pascal programs. The following
4499 main features are supported:
4501 - Pascal-specific data types such as sets;
4503 - automatic recognition of Pascal sources based on file-name
4506 - Pascal-style display of data types, variables, and functions;
4508 - a Pascal expression parser.
4510 However, some important features are not yet supported.
4512 - Pascal string operations are not supported at all;
4514 - there are some problems with boolean types;
4516 - Pascal type hexadecimal constants are not supported
4517 because they conflict with the internal variables format;
4519 - support for Pascal objects and classes is not full yet;
4521 - unlike Pascal, GDB is case-sensitive for symbol names.
4523 * Changes in completion.
4525 Commands such as `shell', `run' and `set args', which pass arguments
4526 to inferior programs, now complete on file names, similar to what
4527 users expect at the shell prompt.
4529 Commands which accept locations, such as `disassemble', `print',
4530 `breakpoint', `until', etc. now complete on filenames as well as
4531 program symbols. Thus, if you type "break foob TAB", and the source
4532 files linked into the programs include `foobar.c', that file name will
4533 be one of the candidates for completion. However, file names are not
4534 considered for completion after you typed a colon that delimits a file
4535 name from a name of a function in that file, as in "break foo.c:bar".
4537 `set demangle-style' completes on available demangling styles.
4539 * New platform-independent commands:
4541 It is now possible to define a post-hook for a command as well as a
4542 hook that runs before the command. For more details, see the
4543 documentation of `hookpost' in the GDB manual.
4545 * Changes in GNU/Linux native debugging.
4547 Support for debugging multi-threaded programs has been completely
4548 revised for all platforms except m68k and sparc. You can now debug as
4549 many threads as your system allows you to have.
4551 Attach/detach is supported for multi-threaded programs.
4553 Support for SSE registers was added for x86. This doesn't work for
4554 multi-threaded programs though.
4556 * Changes in MIPS configurations.
4558 Multi-arch support is enabled for all MIPS configurations.
4560 GDB can now be built as native debugger on SGI Irix 6.x systems for
4561 debugging n32 executables. (Debugging 64-bit executables is not yet
4564 * Unified support for hardware watchpoints in all x86 configurations.
4566 Most (if not all) native x86 configurations support hardware-assisted
4567 breakpoints and watchpoints in a unified manner. This support
4568 implements debug register sharing between watchpoints, which allows to
4569 put a virtually infinite number of watchpoints on the same address,
4570 and also supports watching regions up to 16 bytes with several debug
4573 The new maintenance command `maintenance show-debug-regs' toggles
4574 debugging print-outs in functions that insert, remove, and test
4575 watchpoints and hardware breakpoints.
4577 * Changes in the DJGPP native configuration.
4579 New command ``info dos sysinfo'' displays assorted information about
4580 the CPU, OS, memory, and DPMI server.
4582 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4583 display information about segment descriptors stored in GDT, LDT, and
4586 New commands ``info dos pde'' and ``info dos pte'' display entries
4587 from Page Directory and Page Tables (for now works with CWSDPMI only).
4588 New command ``info dos address-pte'' displays the Page Table entry for
4589 a given linear address.
4591 GDB can now pass command lines longer than 126 characters to the
4592 program being debugged (requires an update to the libdbg.a library
4593 which is part of the DJGPP development kit).
4595 DWARF2 debug info is now supported.
4597 It is now possible to `step' and `next' through calls to `longjmp'.
4599 * Changes in documentation.
4601 All GDB documentation was converted to GFDL, the GNU Free
4602 Documentation License.
4604 Tracepoints-related commands are now fully documented in the GDB
4607 TUI, the Text-mode User Interface, is now documented in the manual.
4609 Tracepoints-related commands are now fully documented in the GDB
4612 The "GDB Internals" manual now has an index. It also includes
4613 documentation of `ui_out' functions, GDB coding standards, x86
4614 hardware watchpoints, and memory region attributes.
4616 * GDB's version number moved to ``version.in''
4618 The Makefile variable VERSION has been replaced by the file
4619 ``version.in''. People creating GDB distributions should update the
4620 contents of this file.
4624 GUD support is now a standard part of the EMACS distribution.
4626 *** Changes in GDB 5.0:
4628 * Improved support for debugging FP programs on x86 targets
4630 Unified and much-improved support for debugging floating-point
4631 programs on all x86 targets. In particular, ``info float'' now
4632 displays the FP registers in the same format on all x86 targets, with
4633 greater level of detail.
4635 * Improvements and bugfixes in hardware-assisted watchpoints
4637 It is now possible to watch array elements, struct members, and
4638 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4639 on x86 targets no longer erroneously trigger when the address is
4642 * Improvements in the native DJGPP version of GDB
4644 The distribution now includes all the scripts and auxiliary files
4645 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4646 machines ``out of the box''.
4648 The DJGPP version can now debug programs that use signals. It is
4649 possible to catch signals that happened in the debuggee, deliver
4650 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4651 would kill the program being debugged.) Programs that hook hardware
4652 interrupts (keyboard, timer, etc.) can also be debugged.
4654 It is now possible to debug DJGPP programs that redirect their
4655 standard handles or switch them to raw (as opposed to cooked) mode, or
4656 even close them. The command ``run < foo > bar'' works as expected,
4657 and ``info terminal'' reports useful information about the debuggee's
4658 terminal, including raw/cooked mode, redirection, etc.
4660 The DJGPP version now uses termios functions for console I/O, which
4661 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4664 DOS-style file names with drive letters are now fully supported by
4667 It is now possible to debug DJGPP programs that switch their working
4668 directory. It is also possible to rerun the debuggee any number of
4669 times without restarting GDB; thus, you can use the same setup,
4670 breakpoints, etc. for many debugging sessions.
4672 * New native configurations
4674 ARM GNU/Linux arm*-*-linux*
4675 PowerPC GNU/Linux powerpc-*-linux*
4679 Motorola MCore mcore-*-*
4680 x86 VxWorks i[3456]86-*-vxworks*
4681 PowerPC VxWorks powerpc-*-vxworks*
4682 TI TMS320C80 tic80-*-*
4684 * OBSOLETE configurations
4686 Altos 3068 m68*-altos-*
4687 Convex c1-*-*, c2-*-*
4689 ARM RISCix arm-*-* (as host)
4692 Configurations that have been declared obsolete will be commented out,
4693 but the code will be left in place. If there is no activity to revive
4694 these configurations before the next release of GDB, the sources will
4695 be permanently REMOVED.
4697 * Gould support removed
4699 Support for the Gould PowerNode and NP1 has been removed.
4701 * New features for SVR4
4703 On SVR4 native platforms (such as Solaris), if you attach to a process
4704 without first loading a symbol file, GDB will now attempt to locate and
4705 load symbols from the running process's executable file.
4707 * Many C++ enhancements
4709 C++ support has been greatly improved. Overload resolution now works properly
4710 in almost all cases. RTTI support is on the way.
4712 * Remote targets can connect to a sub-program
4714 A popen(3) style serial-device has been added. This device starts a
4715 sub-process (such as a stand-alone simulator) and then communicates
4716 with that. The sub-program to run is specified using the syntax
4717 ``|<program> <args>'' vis:
4719 (gdb) set remotedebug 1
4720 (gdb) target extended-remote |mn10300-elf-sim program-args
4722 * MIPS 64 remote protocol
4724 A long standing bug in the mips64 remote protocol where by GDB
4725 expected certain 32 bit registers (ex SR) to be transfered as 32
4726 instead of 64 bits has been fixed.
4728 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4729 added to provide backward compatibility with older versions of GDB.
4731 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4733 The command ``set remotebinarydownload'' command has been replaced by
4734 ``set remote X-packet''. Other commands in ``set remote'' family
4735 include ``set remote P-packet''.
4737 * Breakpoint commands accept ranges.
4739 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4740 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4741 ``tracepoint passcount'' also accepts a range of tracepoints.
4743 * ``apropos'' command added.
4745 The ``apropos'' command searches through command names and
4746 documentation strings, printing out matches, making it much easier to
4747 try to find a command that does what you are looking for.
4751 A new machine oriented interface (MI) has been added to GDB. This
4752 interface is designed for debug environments running GDB as a separate
4753 process. This is part of the long term libGDB project. See the
4754 "GDB/MI" chapter of the GDB manual for further information. It can be
4755 enabled by configuring with:
4757 .../configure --enable-gdbmi
4759 *** Changes in GDB-4.18:
4761 * New native configurations
4763 HP-UX 10.20 hppa*-*-hpux10.20
4764 HP-UX 11.x hppa*-*-hpux11.0*
4765 M68K GNU/Linux m68*-*-linux*
4769 Fujitsu FR30 fr30-*-elf*
4770 Intel StrongARM strongarm-*-*
4771 Mitsubishi D30V d30v-*-*
4773 * OBSOLETE configurations
4775 Gould PowerNode, NP1 np1-*-*, pn-*-*
4777 Configurations that have been declared obsolete will be commented out,
4778 but the code will be left in place. If there is no activity to revive
4779 these configurations before the next release of GDB, the sources will
4780 be permanently REMOVED.
4784 As a compatibility experiment, GDB's source files buildsym.h and
4785 buildsym.c have been converted to pure standard C, no longer
4786 containing any K&R compatibility code. We believe that all systems in
4787 use today either come with a standard C compiler, or have a GCC port
4788 available. If this is not true, please report the affected
4789 configuration to bug-gdb@gnu.org immediately. See the README file for
4790 information about getting a standard C compiler if you don't have one
4795 GDB now uses readline 2.2.
4797 * set extension-language
4799 You can now control the mapping between filename extensions and source
4800 languages by using the `set extension-language' command. For instance,
4801 you can ask GDB to treat .c files as C++ by saying
4802 set extension-language .c c++
4803 The command `info extensions' lists all of the recognized extensions
4804 and their associated languages.
4806 * Setting processor type for PowerPC and RS/6000
4808 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4809 you can use the `set processor' command to specify what variant of the
4810 PowerPC family you are debugging. The command
4814 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4815 following PowerPC and RS6000 variants:
4817 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4818 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4820 403GC IBM PowerPC 403GC
4821 505 Motorola PowerPC 505
4822 860 Motorola PowerPC 860 or 850
4823 601 Motorola PowerPC 601
4824 602 Motorola PowerPC 602
4825 603 Motorola/IBM PowerPC 603 or 603e
4826 604 Motorola PowerPC 604 or 604e
4827 750 Motorola/IBM PowerPC 750 or 750
4829 At the moment, this command just tells GDB what to name the
4830 special-purpose processor registers. Since almost all the affected
4831 registers are inaccessible to user-level programs, this command is
4832 only useful for remote debugging in its present form.
4836 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4837 more extensive support for HP-UX. Added features include shared
4838 library support, kernel threads and hardware watchpoints for 11.00,
4839 support for HP's ANSI C and C++ compilers, and a compatibility mode
4840 for xdb and dbx commands.
4844 HP's donation includes the new concept of catchpoints, which is a
4845 generalization of the old catch command. On HP-UX, it is now possible
4846 to catch exec, fork, and vfork, as well as library loading.
4848 This means that the existing catch command has changed; its first
4849 argument now specifies the type of catch to be set up. See the
4850 output of "help catch" for a list of catchpoint types.
4852 * Debugging across forks
4854 On HP-UX, you can choose which process to debug when a fork() happens
4859 HP has donated a curses-based terminal user interface (TUI). To get
4860 it, build with --enable-tui. Although this can be enabled for any
4861 configuration, at present it only works for native HP debugging.
4863 * GDB remote protocol additions
4865 A new protocol packet 'X' that writes binary data is now available.
4866 Default behavior is to try 'X', then drop back to 'M' if the stub
4867 fails to respond. The settable variable `remotebinarydownload'
4868 allows explicit control over the use of 'X'.
4870 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4871 full 64-bit address. The command
4873 set remoteaddresssize 32
4875 can be used to revert to the old behaviour. For existing remote stubs
4876 the change should not be noticed, as the additional address information
4879 In order to assist in debugging stubs, you may use the maintenance
4880 command `packet' to send any text string to the stub. For instance,
4882 maint packet heythere
4884 sends the packet "$heythere#<checksum>". Note that it is very easy to
4885 disrupt a debugging session by sending the wrong packet at the wrong
4888 The compare-sections command allows you to compare section data on the
4889 target to what is in the executable file without uploading or
4890 downloading, by comparing CRC checksums.
4892 * Tracing can collect general expressions
4894 You may now collect general expressions at tracepoints. This requires
4895 further additions to the target-side stub; see tracepoint.c and
4896 doc/agentexpr.texi for further details.
4898 * mask-address variable for Mips
4900 For Mips targets, you may control the zeroing of the upper 32 bits of
4901 a 64-bit address by entering `set mask-address on'. This is mainly
4902 of interest to users of embedded R4xxx and R5xxx processors.
4904 * Higher serial baud rates
4906 GDB's serial code now allows you to specify baud rates 57600, 115200,
4907 230400, and 460800 baud. (Note that your host system may not be able
4908 to achieve all of these rates.)
4912 The i960 configuration now includes an initial implementation of a
4913 builtin simulator, contributed by Jim Wilson.
4916 *** Changes in GDB-4.17:
4918 * New native configurations
4920 Alpha GNU/Linux alpha*-*-linux*
4921 Unixware 2.x i[3456]86-unixware2*
4922 Irix 6.x mips*-sgi-irix6*
4923 PowerPC GNU/Linux powerpc-*-linux*
4924 PowerPC Solaris powerpcle-*-solaris*
4925 Sparc GNU/Linux sparc-*-linux*
4926 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4930 Argonaut Risc Chip (ARC) arc-*-*
4931 Hitachi H8/300S h8300*-*-*
4932 Matsushita MN10200 w/simulator mn10200-*-*
4933 Matsushita MN10300 w/simulator mn10300-*-*
4934 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4935 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4936 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4937 Mitsubishi D10V w/simulator d10v-*-*
4938 Mitsubishi M32R/D w/simulator m32r-*-elf*
4939 Tsqware Sparclet sparclet-*-*
4940 NEC V850 w/simulator v850-*-*
4942 * New debugging protocols
4944 ARM with RDI protocol arm*-*-*
4945 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4946 DDB and LSI variants of PMON protocol mips*-*-*
4947 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4948 PowerPC with SDS protocol powerpc{,le}-*-eabi
4949 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4953 All configurations can now understand and use the DWARF 2 debugging
4954 format. The choice is automatic, if the symbol file contains DWARF 2
4959 GDB now includes basic Java language support. This support is
4960 only useful with Java compilers that produce native machine code.
4962 * solib-absolute-prefix and solib-search-path
4964 For SunOS and SVR4 shared libraries, you may now set the prefix for
4965 loading absolute shared library symbol files, and the search path for
4966 locating non-absolute shared library symbol files.
4968 * Live range splitting
4970 GDB can now effectively debug code for which GCC has performed live
4971 range splitting as part of its optimization. See gdb/doc/LRS for
4972 more details on the expected format of the stabs information.
4976 GDB's support for the GNU Hurd, including thread debugging, has been
4977 updated to work with current versions of the Hurd.
4981 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4982 instruction set. ARM GDB automatically detects when Thumb
4983 instructions are in use, and adjusts disassembly and backtracing
4988 GDB's MIPS target configurations now handle the MIP16 16-bit
4993 GDB now includes support for overlays; if an executable has been
4994 linked such that multiple sections are based at the same address, GDB
4995 will decide which section to use for symbolic info. You can choose to
4996 control the decision manually, using overlay commands, or implement
4997 additional target-side support and use "overlay load-target" to bring
4998 in the overlay mapping. Do "help overlay" for more detail.
5002 The command "info symbol <address>" displays information about
5003 the symbol at the specified address.
5007 The standard remote protocol now includes an extension that allows
5008 asynchronous collection and display of trace data. This requires
5009 extensive support in the target-side debugging stub. Tracing mode
5010 includes a new interaction mode in GDB and new commands: see the
5011 file tracepoint.c for more details.
5015 Configurations for embedded MIPS now include a simulator contributed
5016 by Cygnus Solutions. The simulator supports the instruction sets
5017 of most MIPS variants.
5021 Sparc configurations may now include the ERC32 simulator contributed
5022 by the European Space Agency. The simulator is not built into
5023 Sparc targets by default; configure with --enable-sim to include it.
5027 For target configurations that may include multiple variants of a
5028 basic architecture (such as MIPS and SH), you may now set the
5029 architecture explicitly. "set arch" sets, "info arch" lists
5030 the possible architectures.
5032 *** Changes in GDB-4.16:
5034 * New native configurations
5036 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5037 M68K NetBSD m68k-*-netbsd*
5038 PowerPC AIX 4.x powerpc-*-aix*
5039 PowerPC MacOS powerpc-*-macos*
5040 PowerPC Windows NT powerpcle-*-cygwin32
5041 RS/6000 AIX 4.x rs6000-*-aix4*
5045 ARM with RDP protocol arm-*-*
5046 I960 with MON960 i960-*-coff
5047 MIPS VxWorks mips*-*-vxworks*
5048 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5049 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5051 Matra Sparclet sparclet-*-*
5055 The powerpc-eabi configuration now includes the PSIM simulator,
5056 contributed by Andrew Cagney, with assistance from Mike Meissner.
5057 PSIM is a very elaborate model of the PowerPC, including not only
5058 basic instruction set execution, but also details of execution unit
5059 performance and I/O hardware. See sim/ppc/README for more details.
5063 GDB now works with Solaris 2.5.
5065 * Windows 95/NT native
5067 GDB will now work as a native debugger on Windows 95 and Windows NT.
5068 To build it from source, you must use the "gnu-win32" environment,
5069 which uses a DLL to emulate enough of Unix to run the GNU tools.
5070 Further information, binaries, and sources are available at
5071 ftp.cygnus.com, under pub/gnu-win32.
5073 * dont-repeat command
5075 If a user-defined command includes the command `dont-repeat', then the
5076 command will not be repeated if the user just types return. This is
5077 useful if the command is time-consuming to run, so that accidental
5078 extra keystrokes don't run the same command many times.
5080 * Send break instead of ^C
5082 The standard remote protocol now includes an option to send a break
5083 rather than a ^C to the target in order to interrupt it. By default,
5084 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5086 * Remote protocol timeout
5088 The standard remote protocol includes a new variable `remotetimeout'
5089 that allows you to set the number of seconds before GDB gives up trying
5090 to read from the target. The default value is 2.
5092 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5094 By default GDB will automatically keep track of objects as they are
5095 loaded and unloaded by the dynamic linker. By using the command `set
5096 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5097 when shared library events occur, thus allowing you to set breakpoints
5098 in shared libraries which are explicitly loaded by the inferior.
5100 Note this feature does not work on hpux8. On hpux9 you must link
5101 /usr/lib/end.o into your program. This feature should work
5102 automatically on hpux10.
5104 * Irix 5.x hardware watchpoint support
5106 Irix 5 configurations now support the use of hardware watchpoints.
5108 * Mips protocol "SYN garbage limit"
5110 When debugging a Mips target using the `target mips' protocol, you
5111 may set the number of characters that GDB will ignore by setting
5112 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5113 every character. The default value is 1050.
5115 * Recording and replaying remote debug sessions
5117 If you set `remotelogfile' to the name of a file, gdb will write to it
5118 a recording of a remote debug session. This recording may then be
5119 replayed back to gdb using "gdbreplay". See gdbserver/README for
5120 details. This is useful when you have a problem with GDB while doing
5121 remote debugging; you can make a recording of the session and send it
5122 to someone else, who can then recreate the problem.
5124 * Speedups for remote debugging
5126 GDB includes speedups for downloading and stepping MIPS systems using
5127 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5128 and more efficient S-record downloading.
5130 * Memory use reductions and statistics collection
5132 GDB now uses less memory and reports statistics about memory usage.
5133 Try the `maint print statistics' command, for example.
5135 *** Changes in GDB-4.15:
5137 * Psymtabs for XCOFF
5139 The symbol reader for AIX GDB now uses partial symbol tables. This
5140 can greatly improve startup time, especially for large executables.
5142 * Remote targets use caching
5144 Remote targets now use a data cache to speed up communication with the
5145 remote side. The data cache could lead to incorrect results because
5146 it doesn't know about volatile variables, thus making it impossible to
5147 debug targets which use memory mapped I/O devices. `set remotecache
5148 off' turns the the data cache off.
5150 * Remote targets may have threads
5152 The standard remote protocol now includes support for multiple threads
5153 in the target system, using new protocol commands 'H' and 'T'. See
5154 gdb/remote.c for details.
5158 If GDB is configured with `--enable-netrom', then it will include
5159 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5160 acts as though it is a bank of ROM on the target board, but you can
5161 write into it over the network. GDB's support consists only of
5162 support for fast loading into the emulated ROM; to debug, you must use
5163 another protocol, such as standard remote protocol. The usual
5164 sequence is something like
5166 target nrom <netrom-hostname>
5168 target remote <netrom-hostname>:1235
5172 GDB now includes support for the Apple Macintosh, as a host only. It
5173 may be run as either an MPW tool or as a standalone application, and
5174 it can debug through the serial port. All the usual GDB commands are
5175 available, but to the target command, you must supply "serial" as the
5176 device type instead of "/dev/ttyXX". See mpw-README in the main
5177 directory for more information on how to build. The MPW configuration
5178 scripts */mpw-config.in support only a few targets, and only the
5179 mips-idt-ecoff target has been tested.
5183 GDB configuration now uses autoconf. This is not user-visible,
5184 but does simplify configuration and building.
5188 GDB now supports hpux10.
5190 *** Changes in GDB-4.14:
5192 * New native configurations
5194 x86 FreeBSD i[345]86-*-freebsd
5195 x86 NetBSD i[345]86-*-netbsd
5196 NS32k NetBSD ns32k-*-netbsd
5197 Sparc NetBSD sparc-*-netbsd
5201 A29K VxWorks a29k-*-vxworks
5202 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5203 CPU32 EST-300 emulator m68*-*-est*
5204 PowerPC ELF powerpc-*-elf
5207 * Alpha OSF/1 support for procfs
5209 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5210 possible to attach to running processes. As the mounting of the /proc
5211 filesystem is optional on the Alpha, GDB automatically determines
5212 the availability of /proc during startup. This can lead to problems
5213 if /proc is unmounted after GDB has been started.
5215 * Arguments to user-defined commands
5217 User commands may accept up to 10 arguments separated by whitespace.
5218 Arguments are accessed within the user command via $arg0..$arg9. A
5221 print $arg0 + $arg1 + $arg2
5223 To execute the command use:
5226 Defines the command "adder" which prints the sum of its three arguments.
5227 Note the arguments are text substitutions, so they may reference variables,
5228 use complex expressions, or even perform inferior function calls.
5230 * New `if' and `while' commands
5232 This makes it possible to write more sophisticated user-defined
5233 commands. Both commands take a single argument, which is the
5234 expression to evaluate, and must be followed by the commands to
5235 execute, one per line, if the expression is nonzero, the list being
5236 terminated by the word `end'. The `if' command list may include an
5237 `else' word, which causes the following commands to be executed only
5238 if the expression is zero.
5240 * Fortran source language mode
5242 GDB now includes partial support for Fortran 77. It will recognize
5243 Fortran programs and can evaluate a subset of Fortran expressions, but
5244 variables and functions may not be handled correctly. GDB will work
5245 with G77, but does not yet know much about symbols emitted by other
5248 * Better HPUX support
5250 Most debugging facilities now work on dynamic executables for HPPAs
5251 running hpux9 or later. You can attach to running dynamically linked
5252 processes, but by default the dynamic libraries will be read-only, so
5253 for instance you won't be able to put breakpoints in them. To change
5254 that behavior do the following before running the program:
5260 This will cause the libraries to be mapped private and read-write.
5261 To revert to the normal behavior, do this:
5267 You cannot set breakpoints or examine data in the library until after
5268 the library is loaded if the function/data symbols do not have
5271 GDB can now also read debug symbols produced by the HP C compiler on
5272 HPPAs (sorry, no C++, Fortran or 68k support).
5274 * Target byte order now dynamically selectable
5276 You can choose which byte order to use with a target system, via the
5277 commands "set endian big" and "set endian little", and you can see the
5278 current setting by using "show endian". You can also give the command
5279 "set endian auto", in which case GDB will use the byte order
5280 associated with the executable. Currently, only embedded MIPS
5281 configurations support dynamic selection of target byte order.
5283 * New DOS host serial code
5285 This version uses DPMI interrupts to handle buffered I/O, so you
5286 no longer need to run asynctsr when debugging boards connected to
5289 *** Changes in GDB-4.13:
5291 * New "complete" command
5293 This lists all the possible completions for the rest of the line, if it
5294 were to be given as a command itself. This is intended for use by emacs.
5296 * Trailing space optional in prompt
5298 "set prompt" no longer adds a space for you after the prompt you set. This
5299 allows you to set a prompt which ends in a space or one that does not.
5301 * Breakpoint hit counts
5303 "info break" now displays a count of the number of times the breakpoint
5304 has been hit. This is especially useful in conjunction with "ignore"; you
5305 can ignore a large number of breakpoint hits, look at the breakpoint info
5306 to see how many times the breakpoint was hit, then run again, ignoring one
5307 less than that number, and this will get you quickly to the last hit of
5310 * Ability to stop printing at NULL character
5312 "set print null-stop" will cause GDB to stop printing the characters of
5313 an array when the first NULL is encountered. This is useful when large
5314 arrays actually contain only short strings.
5316 * Shared library breakpoints
5318 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5319 breakpoints in shared libraries before the executable is run.
5321 * Hardware watchpoints
5323 There is a new hardware breakpoint for the watch command for sparclite
5324 targets. See gdb/sparclite/hw_breakpoint.note.
5326 Hardware watchpoints are also now supported under GNU/Linux.
5330 Annotations have been added. These are for use with graphical interfaces,
5331 and are still experimental. Currently only gdba.el uses these.
5333 * Improved Irix 5 support
5335 GDB now works properly with Irix 5.2.
5337 * Improved HPPA support
5339 GDB now works properly with the latest GCC and GAS.
5341 * New native configurations
5343 Sequent PTX4 i[34]86-sequent-ptx4
5344 HPPA running OSF/1 hppa*-*-osf*
5345 Atari TT running SVR4 m68*-*-sysv4*
5346 RS/6000 LynxOS rs6000-*-lynxos*
5350 OS/9000 i[34]86-*-os9k
5351 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5354 * Hitachi SH7000 and E7000-PC ICE support
5356 There is now support for communicating with the Hitachi E7000-PC ICE.
5357 This is available automatically when GDB is configured for the SH.
5361 As usual, a variety of small fixes and improvements, both generic
5362 and configuration-specific. See the ChangeLog for more detail.
5364 *** Changes in GDB-4.12:
5366 * Irix 5 is now supported
5370 GDB-4.12 on the HPPA has a number of changes which make it unable
5371 to debug the output from the currently released versions of GCC and
5372 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5373 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5374 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5377 *** Changes in GDB-4.11:
5379 * User visible changes:
5383 The "set remotedebug" option is now consistent between the mips remote
5384 target, remote targets using the gdb-specific protocol, UDI (AMD's
5385 debug protocol for the 29k) and the 88k bug monitor. It is now an
5386 integer specifying a debug level (normally 0 or 1, but 2 means more
5387 debugging info for the mips target).
5389 * DEC Alpha native support
5391 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5392 debug info, but GDB works fairly well with the DEC compiler and should
5393 work with a future GCC release. See the README file for a few
5394 Alpha-specific notes.
5396 * Preliminary thread implementation
5398 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5400 * LynxOS native and target support for 386
5402 This release has been hosted on LynxOS 2.2, and also can be configured
5403 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5406 * Improvements in C++ mangling/demangling.
5408 This release has much better g++ debugging, specifically in name
5409 mangling/demangling, virtual function calls, print virtual table,
5410 call methods, ...etc.
5412 *** Changes in GDB-4.10:
5414 * User visible changes:
5416 Remote debugging using the GDB-specific (`target remote') protocol now
5417 supports the `load' command. This is only useful if you have some
5418 other way of getting the stub to the target system, and you can put it
5419 somewhere in memory where it won't get clobbered by the download.
5421 Filename completion now works.
5423 When run under emacs mode, the "info line" command now causes the
5424 arrow to point to the line specified. Also, "info line" prints
5425 addresses in symbolic form (as well as hex).
5427 All vxworks based targets now support a user settable option, called
5428 vxworks-timeout. This option represents the number of seconds gdb
5429 should wait for responses to rpc's. You might want to use this if
5430 your vxworks target is, perhaps, a slow software simulator or happens
5431 to be on the far side of a thin network line.
5435 This release contains support for using a DEC alpha as a GDB host for
5436 cross debugging. Native alpha debugging is not supported yet.
5439 *** Changes in GDB-4.9:
5443 This is the first GDB release which is accompanied by a matching testsuite.
5444 The testsuite requires installation of dejagnu, which should be available
5445 via ftp from most sites that carry GNU software.
5449 'Cfront' style demangling has had its name changed to 'ARM' style, to
5450 emphasize that it was written from the specifications in the C++ Annotated
5451 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5452 disclaimers, it still generated too much confusion with users attempting to
5453 use gdb with AT&T cfront.
5457 GDB now uses a standard remote interface to a simulator library.
5458 So far, the library contains simulators for the Zilog Z8001/2, the
5459 Hitachi H8/300, H8/500 and Super-H.
5461 * New targets supported
5463 H8/300 simulator h8300-hitachi-hms or h8300hms
5464 H8/500 simulator h8500-hitachi-hms or h8500hms
5465 SH simulator sh-hitachi-hms or sh
5466 Z8000 simulator z8k-zilog-none or z8ksim
5467 IDT MIPS board over serial line mips-idt-ecoff
5469 Cross-debugging to GO32 targets is supported. It requires a custom
5470 version of the i386-stub.c module which is integrated with the
5471 GO32 memory extender.
5473 * New remote protocols
5475 MIPS remote debugging protocol.
5477 * New source languages supported
5479 This version includes preliminary support for Chill, a Pascal like language
5480 used by telecommunications companies. Chill support is also being integrated
5481 into the GNU compiler, but we don't know when it will be publically available.
5484 *** Changes in GDB-4.8:
5486 * HP Precision Architecture supported
5488 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5489 version of this support was available as a set of patches from the
5490 University of Utah. GDB does not support debugging of programs
5491 compiled with the HP compiler, because HP will not document their file
5492 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5493 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5495 Many problems in the preliminary version have been fixed.
5497 * Faster and better demangling
5499 We have improved template demangling and fixed numerous bugs in the GNU style
5500 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5501 character types (wchar_t) are now supported. Demangling of each symbol is now
5502 only done once, and is cached when the symbol table for a file is read in.
5503 This results in a small increase in memory usage for C programs, a moderate
5504 increase in memory usage for C++ programs, and a fantastic speedup in
5507 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5508 from the specifications in the Annotated Reference Manual, which AT&T's
5509 compiler does not actually implement.
5511 * G++ multiple inheritance compiler problem
5513 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5514 inheritance lattices was reworked to properly discover ambiguities. We
5515 recently found an example which causes this new algorithm to fail in a
5516 very subtle way, producing bad debug information for those classes.
5517 The file 'gcc.patch' (in this directory) can be applied to gcc to
5518 circumvent the problem. A future GCC release will contain a complete
5521 The previous G++ debug info problem (mentioned below for the gdb-4.7
5522 release) is fixed in gcc version 2.3.2.
5524 * Improved configure script
5526 The `configure' script will now attempt to guess your system type if
5527 you don't supply a host system type. The old scheme of supplying a
5528 host system triplet is preferable over using this. All the magic is
5529 done in the new `config.guess' script. Examine it for details.
5531 We have also brought our configure script much more in line with the FSF's
5532 version. It now supports the --with-xxx options. In particular,
5533 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5534 The resulting GDB will not be able to read arbitrary object file formats --
5535 only the format ``expected'' to be used on the configured target system.
5536 We hope to make this the default in a future release.
5538 * Documentation improvements
5540 There's new internal documentation on how to modify GDB, and how to
5541 produce clean changes to the code. We implore people to read it
5542 before submitting changes.
5544 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5545 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5546 `info' files are also provided. To build `info' files from scratch,
5547 you will need the latest `makeinfo' release, which will be available in
5548 a future texinfo-X.Y release.
5550 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5551 We're not sure exactly which versions have this problem, but it has
5552 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5553 or better. If that isn't possible, there is a patch in
5554 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5555 around this problem.
5559 GDB now supports array constants that can be used in expressions typed in by
5560 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5561 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5564 The new directory `gdb/sparclite' contains a program that demonstrates
5565 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5567 * New native hosts supported
5569 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5570 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5572 * New targets supported
5574 AMD 29k family via UDI a29k-amd-udi or udi29k
5576 * New file formats supported
5578 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5579 HPUX core files, and SCO 3.2v2 core files.
5583 Attaching to processes now works again; thanks for the many bug reports.
5585 We have also stomped on a bunch of core dumps caused by
5586 printf_filtered("%s") problems.
5588 We eliminated a copyright problem on the rpc and ptrace header files
5589 for VxWorks, which was discovered at the last minute during the 4.7
5590 release. You should now be able to build a VxWorks GDB.
5592 You can now interrupt gdb while an attached process is running. This
5593 will cause the attached process to stop, and give control back to GDB.
5595 We fixed problems caused by using too many file descriptors
5596 for reading symbols from object files and libraries. This was
5597 especially a problem for programs that used many (~100) shared
5600 The `step' command now only enters a subroutine if there is line number
5601 information for the subroutine. Otherwise it acts like the `next'
5602 command. Previously, `step' would enter subroutines if there was
5603 any debugging information about the routine. This avoids problems
5604 when using `cc -g1' on MIPS machines.
5606 * Internal improvements
5608 GDB's internal interfaces have been improved to make it easier to support
5609 debugging of multiple languages in the future.
5611 GDB now uses a common structure for symbol information internally.
5612 Minimal symbols (derived from linkage symbols in object files), partial
5613 symbols (from a quick scan of debug information), and full symbols
5614 contain a common subset of information, making it easier to write
5615 shared code that handles any of them.
5617 * New command line options
5619 We now accept --silent as an alias for --quiet.
5623 The memory-mapped-malloc library is now licensed under the GNU Library
5624 General Public License.
5626 *** Changes in GDB-4.7:
5628 * Host/native/target split
5630 GDB has had some major internal surgery to untangle the support for
5631 hosts and remote targets. Now, when you configure GDB for a remote
5632 target, it will no longer load in all of the support for debugging
5633 local programs on the host. When fully completed and tested, this will
5634 ensure that arbitrary host/target combinations are possible.
5636 The primary conceptual shift is to separate the non-portable code in
5637 GDB into three categories. Host specific code is required any time GDB
5638 is compiled on that host, regardless of the target. Target specific
5639 code relates to the peculiarities of the target, but can be compiled on
5640 any host. Native specific code is everything else: it can only be
5641 built when the host and target are the same system. Child process
5642 handling and core file support are two common `native' examples.
5644 GDB's use of /proc for controlling Unix child processes is now cleaner.
5645 It has been split out into a single module under the `target_ops' vector,
5646 plus two native-dependent functions for each system that uses /proc.
5648 * New hosts supported
5650 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5651 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5652 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5654 * New targets supported
5656 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5657 68030 and CPU32 m68030-*-*, m68332-*-*
5659 * New native hosts supported
5661 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5662 (386bsd is not well tested yet)
5663 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5665 * New file formats supported
5667 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5668 supports reading of `a.out.adobe' object files, which are an a.out
5669 format extended with minimal information about multiple sections.
5673 `show copying' is the same as the old `info copying'.
5674 `show warranty' is the same as `info warrantee'.
5675 These were renamed for consistency. The old commands continue to work.
5677 `info handle' is a new alias for `info signals'.
5679 You can now define pre-command hooks, which attach arbitrary command
5680 scripts to any command. The commands in the hook will be executed
5681 prior to the user's command. You can also create a hook which will be
5682 executed whenever the program stops. See gdb.texinfo.
5686 We now deal with Cfront style name mangling, and can even extract type
5687 info from mangled symbols. GDB can automatically figure out which
5688 symbol mangling style your C++ compiler uses.
5690 Calling of methods and virtual functions has been improved as well.
5694 The crash that occured when debugging Sun Ansi-C compiled binaries is
5695 fixed. This was due to mishandling of the extra N_SO stabs output
5698 We also finally got Ultrix 4.2 running in house, and fixed core file
5699 support, with help from a dozen people on the net.
5701 John M. Farrell discovered that the reason that single-stepping was so
5702 slow on all of the Mips based platforms (primarily SGI and DEC) was
5703 that we were trying to demangle and lookup a symbol used for internal
5704 purposes on every instruction that was being stepped through. Changing
5705 the name of that symbol so that it couldn't be mistaken for a C++
5706 mangled symbol sped things up a great deal.
5708 Rich Pixley sped up symbol lookups in general by getting much smarter
5709 about when C++ symbol mangling is necessary. This should make symbol
5710 completion (TAB on the command line) much faster. It's not as fast as
5711 we'd like, but it's significantly faster than gdb-4.6.
5715 A new user controllable variable 'call_scratch_address' can
5716 specify the location of a scratch area to be used when GDB
5717 calls a function in the target. This is necessary because the
5718 usual method of putting the scratch area on the stack does not work
5719 in systems that have separate instruction and data spaces.
5721 We integrated changes to support the 29k UDI (Universal Debugger
5722 Interface), but discovered at the last minute that we didn't have all
5723 of the appropriate copyright paperwork. We are working with AMD to
5724 resolve this, and hope to have it available soon.
5728 We have sped up the remote serial line protocol, especially for targets
5729 with lots of registers. It now supports a new `expedited status' ('T')
5730 message which can be used in place of the existing 'S' status message.
5731 This allows the remote stub to send only the registers that GDB
5732 needs to make a quick decision about single-stepping or conditional
5733 breakpoints, eliminating the need to fetch the entire register set for
5734 each instruction being stepped through.
5736 The GDB remote serial protocol now implements a write-through cache for
5737 registers, only re-reading the registers if the target has run.
5739 There is also a new remote serial stub for SPARC processors. You can
5740 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5741 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5742 processor with a serial port.
5746 Configure.in files have become much easier to read and modify. A new
5747 `table driven' format makes it more obvious what configurations are
5748 supported, and what files each one uses.
5752 There is a new opcodes library which will eventually contain all of the
5753 disassembly routines and opcode tables. At present, it only contains
5754 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5755 disassembler (binutils/objdump) to share these routines.
5757 The libiberty library is now copylefted under the GNU Library General
5758 Public License. This allows more liberal use, and was done so libg++
5759 can use it. This makes no difference to GDB, since the Library License
5760 grants all the rights from the General Public License.
5764 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5765 reference to the stabs symbol info used by the debugger. It is (as far
5766 as we know) the only published document on this fascinating topic. We
5767 encourage you to read it, compare it to the stabs information on your
5768 system, and send improvements on the document in general (to
5769 bug-gdb@prep.ai.mit.edu).
5771 And, of course, many bugs have been fixed.
5774 *** Changes in GDB-4.6:
5776 * Better support for C++ function names
5778 GDB now accepts as input the "demangled form" of C++ overloaded function
5779 names and member function names, and can do command completion on such names
5780 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5781 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5782 Make use of command completion, it is your friend.
5784 GDB also now accepts a variety of C++ mangled symbol formats. They are
5785 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5786 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5787 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5788 for the list of formats.
5790 * G++ symbol mangling problem
5792 Recent versions of gcc have a bug in how they emit debugging information for
5793 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5794 directory) can be applied to gcc to fix the problem. Alternatively, if you
5795 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5796 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5797 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5800 * New 'maintenance' command
5802 All of the commands related to hacking GDB internals have been moved out of
5803 the main command set, and now live behind the 'maintenance' command. This
5804 can also be abbreviated as 'mt'. The following changes were made:
5806 dump-me -> maintenance dump-me
5807 info all-breakpoints -> maintenance info breakpoints
5808 printmsyms -> maintenance print msyms
5809 printobjfiles -> maintenance print objfiles
5810 printpsyms -> maintenance print psymbols
5811 printsyms -> maintenance print symbols
5813 The following commands are new:
5815 maintenance demangle Call internal GDB demangler routine to
5816 demangle a C++ link name and prints the result.
5817 maintenance print type Print a type chain for a given symbol
5819 * Change to .gdbinit file processing
5821 We now read the $HOME/.gdbinit file before processing the argv arguments
5822 (e.g. reading symbol files or core files). This allows global parameters to
5823 be set, which will apply during the symbol reading. The ./.gdbinit is still
5824 read after argv processing.
5826 * New hosts supported
5828 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5830 GNU/Linux support i386-unknown-linux or linux
5832 We are also including code to support the HP/PA running BSD and HPUX. This
5833 is almost guaranteed not to work, as we didn't have time to test or build it
5834 for this release. We are including it so that the more adventurous (or
5835 masochistic) of you can play with it. We also had major problems with the
5836 fact that the compiler that we got from HP doesn't support the -g option.
5839 * New targets supported
5841 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5843 * More smarts about finding #include files
5845 GDB now remembers the compilation directory for all include files, and for
5846 all files from which C is generated (like yacc and lex sources). This
5847 greatly improves GDB's ability to find yacc/lex sources, and include files,
5848 especially if you are debugging your program from a directory different from
5849 the one that contains your sources.
5851 We also fixed a bug which caused difficulty with listing and setting
5852 breakpoints in include files which contain C code. (In the past, you had to
5853 try twice in order to list an include file that you hadn't looked at before.)
5855 * Interesting infernals change
5857 GDB now deals with arbitrary numbers of sections, where the symbols for each
5858 section must be relocated relative to that section's landing place in the
5859 target's address space. This work was needed to support ELF with embedded
5860 stabs used by Solaris-2.0.
5862 * Bug fixes (of course!)
5864 There have been loads of fixes for the following things:
5865 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5866 i960, stabs, DOS(GO32), procfs, etc...
5868 See the ChangeLog for details.
5870 *** Changes in GDB-4.5:
5872 * New machines supported (host and target)
5874 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5876 SGI Irix-4.x mips-sgi-irix4 or iris4
5878 * New malloc package
5880 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5881 Mmalloc is capable of handling mutiple heaps of memory. It is also
5882 capable of saving a heap to a file, and then mapping it back in later.
5883 This can be used to greatly speedup the startup of GDB by using a
5884 pre-parsed symbol table which lives in a mmalloc managed heap. For
5885 more details, please read mmalloc/mmalloc.texi.
5889 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5890 'help info proc' for details.
5892 * MIPS ecoff symbol table format
5894 The code that reads MIPS symbol table format is now supported on all hosts.
5895 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5898 * File name changes for MS-DOS
5900 Many files in the config directories have been renamed to make it easier to
5901 support GDB on MS-DOSe systems (which have very restrictive file name
5902 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5903 environment) is close to working but has some remaining problems. Note
5904 that debugging of DOS programs is not supported, due to limitations
5905 in the ``operating system'', but it can be used to host cross-debugging.
5907 * Cross byte order fixes
5909 Many fixes have been made to support cross debugging of Sparc and MIPS
5910 targets from hosts whose byte order differs.
5912 * New -mapped and -readnow options
5914 If memory-mapped files are available on your system through the 'mmap'
5915 system call, you can use the -mapped option on the `file' or
5916 `symbol-file' commands to cause GDB to write the symbols from your
5917 program into a reusable file. If the program you are debugging is
5918 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5919 Future GDB debugging sessions will notice the presence of this file,
5920 and will quickly map in symbol information from it, rather than reading
5921 the symbol table from the executable program. Using the '-mapped'
5922 option in a GDB `file' or `symbol-file' command has the same effect as
5923 starting GDB with the '-mapped' command-line option.
5925 You can cause GDB to read the entire symbol table immediately by using
5926 the '-readnow' option with any of the commands that load symbol table
5927 information (or on the GDB command line). This makes the command
5928 slower, but makes future operations faster.
5930 The -mapped and -readnow options are typically combined in order to
5931 build a `fred.syms' file that contains complete symbol information.
5932 A simple GDB invocation to do nothing but build a `.syms' file for future
5935 gdb -batch -nx -mapped -readnow programname
5937 The `.syms' file is specific to the host machine on which GDB is run.
5938 It holds an exact image of GDB's internal symbol table. It cannot be
5939 shared across multiple host platforms.
5941 * longjmp() handling
5943 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5944 siglongjmp() without losing control. This feature has not yet been ported to
5945 all systems. It currently works on many 386 platforms, all MIPS-based
5946 platforms (SGI, DECstation, etc), and Sun3/4.
5950 Preliminary work has been put in to support the new Solaris OS from Sun. At
5951 this time, it can control and debug processes, but it is not capable of
5956 As always, many many bug fixes. The major areas were with g++, and mipsread.
5957 People using the MIPS-based platforms should experience fewer mysterious
5958 crashes and trashed symbol tables.
5960 *** Changes in GDB-4.4:
5962 * New machines supported (host and target)
5964 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5966 BSD Reno on Vax vax-dec-bsd
5967 Ultrix on Vax vax-dec-ultrix
5969 * New machines supported (target)
5971 AMD 29000 embedded, using EBMON a29k-none-none
5975 GDB continues to improve its handling of C++. `References' work better.
5976 The demangler has also been improved, and now deals with symbols mangled as
5977 per the Annotated C++ Reference Guide.
5979 GDB also now handles `stabs' symbol information embedded in MIPS
5980 `ecoff' symbol tables. Since the ecoff format was not easily
5981 extensible to handle new languages such as C++, this appeared to be a
5982 good way to put C++ debugging info into MIPS binaries. This option
5983 will be supported in the GNU C compiler, version 2, when it is
5986 * New features for SVR4
5988 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5989 shared libraries. Debugging dynamically linked programs should present
5990 only minor differences from debugging statically linked programs.
5992 The `info proc' command will print out information about any process
5993 on an SVR4 system (including the one you are debugging). At the moment,
5994 it prints the address mappings of the process.
5996 If you bring up GDB on another SVR4 system, please send mail to
5997 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5999 * Better dynamic linking support in SunOS
6001 Reading symbols from shared libraries which contain debugging symbols
6002 now works properly. However, there remain issues such as automatic
6003 skipping of `transfer vector' code during function calls, which
6004 make it harder to debug code in a shared library, than to debug the
6005 same code linked statically.
6009 GDB is now using the latest `getopt' routines from the FSF. This
6010 version accepts the -- prefix for options with long names. GDB will
6011 continue to accept the old forms (-option and +option) as well.
6012 Various single letter abbreviations for options have been explicity
6013 added to the option table so that they won't get overshadowed in the
6014 future by other options that begin with the same letter.
6018 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6019 Many assorted bugs have been handled. Many more remain to be handled.
6020 See the various ChangeLog files (primarily in gdb and bfd) for details.
6023 *** Changes in GDB-4.3:
6025 * New machines supported (host and target)
6027 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6028 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6029 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6031 * Almost SCO Unix support
6033 We had hoped to support:
6034 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6035 (except for core file support), but we discovered very late in the release
6036 that it has problems with process groups that render gdb unusable. Sorry
6037 about that. I encourage people to fix it and post the fixes.
6039 * Preliminary ELF and DWARF support
6041 GDB can read ELF object files on System V Release 4, and can handle
6042 debugging records for C, in DWARF format, in ELF files. This support
6043 is preliminary. If you bring up GDB on another SVR4 system, please
6044 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6049 GDB now uses the latest `readline' library. One user-visible change
6050 is that two tabs will list possible command completions, which previously
6051 required typing M-? (meta-question mark, or ESC ?).
6055 The `stepi' bug that many of you noticed has been squashed.
6056 Many bugs in C++ have been handled. Many more remain to be handled.
6057 See the various ChangeLog files (primarily in gdb and bfd) for details.
6059 * State of the MIPS world (in case you wondered):
6061 GDB can understand the symbol tables emitted by the compilers
6062 supplied by most vendors of MIPS-based machines, including DEC. These
6063 symbol tables are in a format that essentially nobody else uses.
6065 Some versions of gcc come with an assembler post-processor called
6066 mips-tfile. This program is required if you want to do source-level
6067 debugging of gcc-compiled programs. I believe FSF does not ship
6068 mips-tfile with gcc version 1, but it will eventually come with gcc
6071 Debugging of g++ output remains a problem. g++ version 1.xx does not
6072 really support it at all. (If you're lucky, you should be able to get
6073 line numbers and stack traces to work, but no parameters or local
6074 variables.) With some work it should be possible to improve the
6077 When gcc version 2 is released, you will have somewhat better luck.
6078 However, even then you will get confusing results for inheritance and
6081 We will eventually provide full debugging of g++ output on
6082 DECstations. This will probably involve some kind of stabs-in-ecoff
6083 encapulation, but the details have not been worked out yet.
6086 *** Changes in GDB-4.2:
6088 * Improved configuration
6090 Only one copy of `configure' exists now, and it is not self-modifying.
6091 Porting BFD is simpler.
6095 The `step' and `next' commands now only stop at the first instruction
6096 of a source line. This prevents the multiple stops that used to occur
6097 in switch statements, for-loops, etc. `Step' continues to stop if a
6098 function that has debugging information is called within the line.
6102 Lots of small bugs fixed. More remain.
6104 * New host supported (not target)
6106 Intel 386 PC clone running Mach i386-none-mach
6109 *** Changes in GDB-4.1:
6111 * Multiple source language support
6113 GDB now has internal scaffolding to handle several source languages.
6114 It determines the type of each source file from its filename extension,
6115 and will switch expression parsing and number formatting to match the
6116 language of the function in the currently selected stack frame.
6117 You can also specifically set the language to be used, with
6118 `set language c' or `set language modula-2'.
6122 GDB now has preliminary support for the GNU Modula-2 compiler,
6123 currently under development at the State University of New York at
6124 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6125 continue through the fall of 1991 and into 1992.
6127 Other Modula-2 compilers are currently not supported, and attempting to
6128 debug programs compiled with them will likely result in an error as the
6129 symbol table is read. Feel free to work on it, though!
6131 There are hooks in GDB for strict type checking and range checking,
6132 in the `Modula-2 philosophy', but they do not currently work.
6136 GDB can now write to executable and core files (e.g. patch
6137 a variable's value). You must turn this switch on, specify
6138 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6139 by assigning a new value to a variable. Modifications take
6142 * Automatic SunOS shared library reading
6144 When you run your program, GDB automatically determines where its
6145 shared libraries (if any) have been loaded, and reads their symbols.
6146 The `share' command is no longer needed. This also works when
6147 examining core files.
6151 You can specify the number of lines that the `list' command shows.
6154 * New machines supported (host and target)
6156 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6157 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6158 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6160 * New hosts supported (not targets)
6162 IBM RT/PC: romp-ibm-aix or rtpc
6164 * New targets supported (not hosts)
6166 AMD 29000 embedded with COFF a29k-none-coff
6167 AMD 29000 embedded with a.out a29k-none-aout
6168 Ultracomputer remote kernel debug a29k-nyu-kern
6170 * New remote interfaces
6176 *** Changes in GDB-4.0:
6180 Wide output is wrapped at good places to make the output more readable.
6182 Gdb now supports cross-debugging from a host machine of one type to a
6183 target machine of another type. Communication with the target system
6184 is over serial lines. The ``target'' command handles connecting to the
6185 remote system; the ``load'' command will download a program into the
6186 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6187 also supports debugging of realtime processes running under VxWorks,
6188 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6189 stub on the target system.
6191 New CPUs supported include the AMD 29000 and Intel 960.
6193 GDB now reads object files and symbol tables via a ``binary file''
6194 library, which allows a single copy of GDB to debug programs of multiple
6195 object file types such as a.out and coff.
6197 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6198 refcard.dvi and refcard.ps are available to format it).
6201 * Control-Variable user interface simplified
6203 All variables that control the operation of the debugger can be set
6204 by the ``set'' command, and displayed by the ``show'' command.
6206 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6207 ``Show prompt'' produces the response:
6208 Gdb's prompt is new-gdb=>.
6210 What follows are the NEW set commands. The command ``help set'' will
6211 print a complete list of old and new set commands. ``help set FOO''
6212 will give a longer description of the variable FOO. ``show'' will show
6213 all of the variable descriptions and their current settings.
6215 confirm on/off: Enables warning questions for operations that are
6216 hard to recover from, e.g. rerunning the program while
6217 it is already running. Default is ON.
6219 editing on/off: Enables EMACS style command line editing
6220 of input. Previous lines can be recalled with
6221 control-P, the current line can be edited with control-B,
6222 you can search for commands with control-R, etc.
6225 history filename NAME: NAME is where the gdb command history
6226 will be stored. The default is .gdb_history,
6227 or the value of the environment variable
6230 history size N: The size, in commands, of the command history. The
6231 default is 256, or the value of the environment variable
6234 history save on/off: If this value is set to ON, the history file will
6235 be saved after exiting gdb. If set to OFF, the
6236 file will not be saved. The default is OFF.
6238 history expansion on/off: If this value is set to ON, then csh-like
6239 history expansion will be performed on
6240 command line input. The default is OFF.
6242 radix N: Sets the default radix for input and output. It can be set
6243 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6244 in the current radix, so "set radix 10" is always a no-op.
6246 height N: This integer value is the number of lines on a page. Default
6247 is 24, the current `stty rows'' setting, or the ``li#''
6248 setting from the termcap entry matching the environment
6251 width N: This integer value is the number of characters on a line.
6252 Default is 80, the current `stty cols'' setting, or the ``co#''
6253 setting from the termcap entry matching the environment
6256 Note: ``set screensize'' is obsolete. Use ``set height'' and
6257 ``set width'' instead.
6259 print address on/off: Print memory addresses in various command displays,
6260 such as stack traces and structure values. Gdb looks
6261 more ``symbolic'' if you turn this off; it looks more
6262 ``machine level'' with it on. Default is ON.
6264 print array on/off: Prettyprint arrays. New convenient format! Default
6267 print demangle on/off: Print C++ symbols in "source" form if on,
6270 print asm-demangle on/off: Same, for assembler level printouts
6273 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6276 * Support for Epoch Environment.
6278 The epoch environment is a version of Emacs v18 with windowing. One
6279 new command, ``inspect'', is identical to ``print'', except that if you
6280 are running in the epoch environment, the value is printed in its own
6284 * Support for Shared Libraries
6286 GDB can now debug programs and core files that use SunOS shared libraries.
6287 Symbols from a shared library cannot be referenced
6288 before the shared library has been linked with the program (this
6289 happens after you type ``run'' and before the function main() is entered).
6290 At any time after this linking (including when examining core files
6291 from dynamically linked programs), gdb reads the symbols from each
6292 shared library when you type the ``sharedlibrary'' command.
6293 It can be abbreviated ``share''.
6295 sharedlibrary REGEXP: Load shared object library symbols for files
6296 matching a unix regular expression. No argument
6297 indicates to load symbols for all shared libraries.
6299 info sharedlibrary: Status of loaded shared libraries.
6304 A watchpoint stops execution of a program whenever the value of an
6305 expression changes. Checking for this slows down execution
6306 tremendously whenever you are in the scope of the expression, but is
6307 quite useful for catching tough ``bit-spreader'' or pointer misuse
6308 problems. Some machines such as the 386 have hardware for doing this
6309 more quickly, and future versions of gdb will use this hardware.
6311 watch EXP: Set a watchpoint (breakpoint) for an expression.
6313 info watchpoints: Information about your watchpoints.
6315 delete N: Deletes watchpoint number N (same as breakpoints).
6316 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6317 enable N: Re-enables watchpoint number N (same as breakpoints).
6320 * C++ multiple inheritance
6322 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6325 * C++ exception handling
6327 Gdb now supports limited C++ exception handling. Besides the existing
6328 ability to breakpoint on an exception handler, gdb can breakpoint on
6329 the raising of an exception (before the stack is peeled back to the
6332 catch FOO: If there is a FOO exception handler in the dynamic scope,
6333 set a breakpoint to catch exceptions which may be raised there.
6334 Multiple exceptions (``catch foo bar baz'') may be caught.
6336 info catch: Lists all exceptions which may be caught in the
6337 current stack frame.
6340 * Minor command changes
6342 The command ``call func (arg, arg, ...)'' now acts like the print
6343 command, except it does not print or save a value if the function's result
6344 is void. This is similar to dbx usage.
6346 The ``up'' and ``down'' commands now always print the frame they end up
6347 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6348 frames without printing.
6350 * New directory command
6352 'dir' now adds directories to the FRONT of the source search path.
6353 The path starts off empty. Source files that contain debug information
6354 about the directory in which they were compiled can be found even
6355 with an empty path; Sun CC and GCC include this information. If GDB can't
6356 find your source file in the current directory, type "dir .".
6358 * Configuring GDB for compilation
6360 For normal use, type ``./configure host''. See README or gdb.texinfo
6363 GDB now handles cross debugging. If you are remotely debugging between
6364 two different machines, type ``./configure host -target=targ''.
6365 Host is the machine where GDB will run; targ is the machine
6366 where the program that you are debugging will run.